DEPARTMENT OF THE INTERIOR 

v/ 

UNITED STATES, GEOLOGICAL SURVEY, 

GEORGE OTIS --SMITH, DIRECTOR 

PROFESSTONAT. PAPEH 71 I .,, 

INDEX TO THE STRATIGRAPHY 

OF NORTH AMERICA 

BY 

BAILEY WILLIS 

ACCOMPANIED BY A 

GEOLOGIC MAP OF NORTH AMERICA 

COMPILED BY THE UNITED STATES GEOLOGICAL SURVEY IN COOPERATION WITH THE 

GEOLOGICAL SURVEY OF CANADA AND THE INSTITUTO GEOLOGICO DE MEXICO 

UNDER THE SUPERVISION OF BAILEY WILLIS AND GEORGE W. STOSE 

133fi3 

WASHINGTON 

GOVERNMENT PRINTING OFFICE 

1U12 

CONTENTS. 

CHAPTER I. Introduction. _____________________________________________ -_--------------------------------

Contents.-- _____________ ------------------------------ -------------------- ------- ------------- ------

Arrangement of materiaL _________________ -- _____________ --- --- ---------------------------------------

Geologic divisions mapped ______________________________________________ ------------ ------------- ----

Acknowledgments. ______________________________________________________ --------------_-------------- Color scheme ________________________________________________________________________________________ _ 

Principles. ______________________________________________________________________________________ _ 

Usages. _________________________________________________________________________________________ _ 

Principles for coloring geologic maps. __________________________________ - _- ____________ -- . ---- _____ _ 

Contributors. ___________________________________________________________ ---- _- _________ --- ------ ____ _ 

CHAPTER II. Pre-Cambrian _________________________________________________ -- ___ - __________ ------ -- _- __ -

CHAPTER III. Cambrian and lower Ordovician. ________________________________________________ -- _________ _ 

CHAPTER IV. Middle and upper Ordovician. __________________________________ -- _____________ --------_- __ _ 

CHAPTER V. Silurian. _______________________________________________________________________ ------_- ____ _ 

CHAPTER VI. Devonian. ____________________________________________________________________ -- __________ _ 

CHAPTER VII. Paleozoic undivided ____________________________ - ______________ ----------_-- ___ ------------_ 

CHAPTER VIII. Carboniferous undivided ______________________________________ - ___ - __________ ----.--- ____ _ 

CHAPTER IX. Mississippian. _____________________________________________________________________________ _ 

CHAPTER X. Pennsylvanian. _____________________________________________________________________________ _ 

CHAPTER XI. Permian. __________________________________________________________________________________ _ 

CHAPTER XII. Triassic. ____________________________________________________ ----------- _____ ---------- __ _ 

CHAPTER XIII. Jurassic _____________________________________________________________________ - - - - _ - ______ _ 

CHAPTER XIV. Lower Cretaceous. ___________ . ________________________________ -- ______________ -- _- ________ _ 

CHAPTER XV. Upper Cretaceous. ____________________________________________ -- _______________ - __________ _ 

CHAPTER XVL Earlier Tertiary (Eocene and Oligocene) _____________________________________________ . _____ _ 

CHAPTER XVII. Later Tertiary (Miocene and Pliocene) ________________________ - _______________ - ____ . _____ _ 

CHAPTER XVIII. Bibliography __________________________________________________________________________ _ 

INDEX ---------------- - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

ILLUSTRATIONS. 

Page. 

5 

5 

6 

7 

20 

21 

21 

23 

27 

30 

62 

72 

156 

225 

269 

342. 

355 

401 

425 

474 

500 

549 

579 

637 

706 

794 

840 

867 

Page. 

PLATE I. Geologic map of North America .... __ ._________________________________________________________ In box. 

FIGURE L Sketch map showing the distribution of post-Cambrian intrusive rocks represented on the geologic map 

of North America _______________ .. _ .......... __ ................ __ ........ ___ .... _ . _ _ _ _ _ _ _ _ _ 18 

2. Sketch map showing the distribution of Tertiary and later effusive rocks represented on the geologic 

map of North America ........................................ ______________________________ 19 

3. Sketch map showing the distribution of pre-Cambrian rocks represented on the geologic map of 

North America and tho key to references in the text._____ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 63 

4. Classification of the pre-Cambrian adopted by the International Committee _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 67 

5. Sketch map showing the distribution of Cambrian and lower Ordovician rocks represented on the 

geologic map of North America and tho key to references in the text _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 73 

6. Sketch map showing the distribution of middle and upper Ordovician rocks represented on the 

geologic map of North America and the key to references in the text _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 157 

7. Sketch map showing the distribution of Silurian rocks represented on the geologic map of North 

America and the key to references in the text _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 226 

8. Sketch map showing the distribution of Devonian rocks represented on the geologic map of North 

America and the key to references in the text _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 270 

9. Sketch map showing the distribution of Paleozoic rocks that are undivided on the geologic map uf 

North America and the key to the references in the text __ . _ •. _ .. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 343 

3 
4 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Page. 

FIGURE 10. Sketch map showing the distribution of Carboniferous rocks that are undivided on the geologic map 

of North America and the key to references in the text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356 

11. SkPtch map showing the distribution of l\Iississippian rocks that are separately represented on the 

geologic map of North America and the key to references in the text . .. . ... ... ... . . . . . . . . . . . . . . . 402 

12. Sketch map showing the di8tribution of Pennsylvanian rocks that are separately represented on the 

geologic map of North America and the key to references in the text............................ 426 

13. Sketch map showing the distribution of Permian rocks that are separately represented on the geologic map of North America and the key to references in the text............................... 475 

14. Sketch map showing the distribution of Triassic rocks and of undivided Triassic and Jurassic rocks 

that are so represented on the geologic map of North America and the key to references in the 

text....................................................................................... 501 

1.5. Sketch map showing the distribution of Jurassic rocks that are separately represented on the geologic map of North America and the key to references in the text ...... ... ... . . . . . . . . . . . . . . . . . . . 550 

16. Sketch map showing the distribution of Lower Cretaceous rocks represented on the geologic map of 

North America and the key to references in the text............................................ 580 

17. Sketch map showing the distribution of Upper Cretaceous rocks represented on the geologic map of 

North America and the key to references in the text........................................... 638 

18. Sketch map showing the distribution of earlier Tertiary rocks represented on the geologic map of 

North America and the key to references in the text.............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 707 

19. Sketch map showing the distribution of later Tertiary rocks represented on the geologic map of 

North America and the key to references in the text............ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 795 

INSERTS. 

.Stratigraphy of the Pennsylvanian of Kansas, as interpreted by different authors .......................... . 

Carboniferous formations in different parts of the western interior coal field ................................ . 

Correlations in eastern interior coal region ............................................................... . 

Correlation of the Cretaceous deposits of the eastern Gulf region and of the Carolinas ....................... . 

Section of older Tertiary formations in Arkansas, Louisiana, and eastern Texas ..................... · ...... . 

Page. 

458 

458 

468 

654 

724 
INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

By DArLEY vVrLus. 

CHAPTER I. 

INTRODUCTION. 

CONTENTS. 

The "Index to the stratigraphy of North America" is a compilation designed 

to explain the geologic map which accompanies it. The compiler has assembled 

the latest or most authoritative statements of fact and opinion, selected according 

to his best judgment. He has been most helpfully advised by many colleagues, to 

whom he is under more obligation than he can here express. In a subjoined list 

(pp. 30-61) scientific credit is given to each person who has taken part in the work 

or from whom contributions have been received. 

The material selected comprises discussions of stratigraphy, some citations of 

fossils, and some views on correlation. The aim has been to state stratigraphic 

facts as fully as the data available or the scope of the work permit and to include 

as much as space allows relating to faunas and correlation. Quotation is preferred, 

but where it was not practicable an abstract of facts has been made and the 

reference given. 

The sources from which quotations have been taken include publications of all 

kinds, official, serial, and occasional. They are listed in the bibliography on pages 

840-865. Many more have been consulted. The entries in the bibliography are 

numbered consecutively and corresponding numbers, printed as "superiors," are 

used in the text to indicate references. 

The method of procedure in selecting material was based on the map, which 

furnishes the information that strata of a given age occur in a certain locality. If 

no other clue was available the province or State was looked up in the indexes to the 

volumes of the "Bibliography of North American geology," 616• 617• 870• 871• 8

7 2, 874 

where the latest writing, at least since 1892, may be traced to the authors. In case 

a specific formation was in question, its name was followed up in the same indices 

or lists and all references to it during the last 18 years considered. In the later 

works earlier ones are usually cited. Occasionally some one geologist is so identified 

with the investigation of a particular subject or region that immediate reference to 

his works 'Yas suggested, but not in any instance intentionally to the exclusion of 

other observers. 

5 
6 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The Canadian Survey has issued two bibliographies, 289• 518 which were very 

useful. In them subjects may readily be traced by locality, geologic division, or 

geologist. 

For North American geology prior to 1892, the bibliography by Darton 230 has 

been used. 

In addition to published material, the compiler has been freely given a very 

large amount of unpublished information from the records of the United States 

Geological Survey. Some has been taken from official manuscripts and some from 

notes prepared for this paper. All this material is credited in the text and in the 

list on pages 30-61, which shows the names of the contributors and the localities 

which they have described. 

ARRANGEMENT OF MATERIAL. 

The material assembled has been arranged arbitrarily according to the index 

of the map, in order to facilitate reference between the map and the text. Natural 

divisions and systematic classification have thus been subordinated to convenience. 

The map is divided by parallels at intervals of 4 degrees and by meridians at 

intervals of 6 degrees, according to the plan of sheets of the Standard International 

Map of the World. Any space thus inclosed is designated by a letter and a number. 

The letters run from A at the equator to Vat the pole, and may be said to designate 

zones. For example, zone A is bounded by the equator on the south and by the 

parallel of 4° north latitude on the north; zone H includes northern Mexico and the 

Gulf coast of the United States; zones Land Mare traversed by the boundary of 

the United States and Canada; zones P, Q, and R comprise Alaska, northern Canada, 

and southern Greenland. 

The spaces between meridians are numbered from west to east, from longitude 

180° to Greenwich. In accordance with the usage of European cartographers, 

these spaces may be called columns. Alaska falls in columns 3 to 7. The eastern 

United States, Quebec, and the Labrador Peninsula lie in columns 18, 19, and 20. 

The letter and number which designate the zone and column in which any 

division of the map lies define the position of that division and may be employed to 

designate it. For example, division L 18 comprises the St. Lawrence from Lake 

Ontario nearly to Quebec; J--K 13 covers the Rocky Mountains of ·wyoming and 

Colorado; and E 14 takes in the City of Mexico and vicinity. The index divisions 

are employed throughout this work to designate areas. 

The division into chapters is based on geologic divisions and in general each 

chapter corresponds with a geologic system or period defined by the current usage 

of the United States Geological Survey and named in the legend of the map, but 

there are departures from a systematic classification which arise partly from the 

exigencies of cartography and partly from the inaptness of standards. These 

departures are stated below, in the legend of the map, and in connection with each 

chapter also. 

The order of description follows the alphabetical and numerical sequence-that 

is, from B 17 to B 20, then from C 16 to C 20, etc., wherever the outcrops of strata 

or the system under consideration occur. Each zone is followed from west to east 
GEOLOGIC DIVISIONS MAPPED. 7 

and those divisions in which the system under description is known are taken up in 

numerical order. The intervening map divisions are skipped. This arbitrary 

order traverses all natural and political boundaries. The scope of some publications covers more than one zone or one column, in such a way as to necessitate the 

discussion of two or more divisions under one heading. 

It is assumed that the text and map will be used together. To refer from the 

map to the text, note the letter and number of the map index for the area under 

examination and look them up in the chapter which describes the geologic system 

studied. If the reader has simply a certain spot of color on the map in view, the 

corresponding color in the legend of the map will give the name of the system and 

chapter. 

To refer from the text to the map, note the chapter heading and map index 

under which a citation occurs and by aid of the legend and index on the margin of 

the map identify the corresponding spot of color. 

GEOLOGIC DIVISIONS MAPPED. 

The geologic divisions represented on the map are adjusted to the requirements 

of cartography. They involve a compromise between the accepted standards of 

geologic science and the facts of history. The latter point can not be adequately 

discussed here, but it is true that the European standard (or that of New York in 

so far as it conforms to that of Europe) is a close approximation to the natural 

classification in the Atlantic and Gulf provinces only, and that it does not correspond 

satisfactorily with the natural order of events in the Pacific and interior provinces. 

The limitations of cartographic representation are inherent in the scale of the 

map and the processes of printing. The scale of the map was selected with reference 

to its use as a wall map and the major features of the continent are intended to be 

apparent at a distance. They must therefore have at least a certain minimum 

size and color distinction. The employment of the map for local reference is, however, desirable, and to this end more refined drafting with slighter distinctions of 

color is desirable. These minor distinctions have been pushed to the limit of lithographic methods. 

Whatever geologic systems, series, groups, or formations may be adopted, it will 

be found that they can not be carried uniformly and with constant value over so 

broad a territory as North Americ::t, for several reasons. 

The major problems arise from one or another of several conditions-the 

scale of the map; differences of knowledge and ignorance; differences among classifications peculiar to the surveys of Canada, Mexico, and the United States; unlike 

development of the geologic series in diverse provinces. 

The scale of the map sets a limit to refinement of possible classification. On a 

large-scale map may be drawn or printed legibly narrow strips of color, which may 

represent formations or even subdivisions (members) of formations. On a map 

of smaller scale a color strip of the same minimum width covers the space representing a thick formation or a group or a series. Thus the desirability of printing a 

map that shall be legible controls the width of a color band, and the latter in turn 

determines the least geologic division that can be recognized. The real limitation 
-----------------------------------

8 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

in this regard is the space occupied by a least geologic division and it is therefore 

dependent on structure as well as on classification. ·where strata lie flat they 

present as a rule wide expanses, but where they dip steeply they exhibit narrow 

edges. The latter is apt to be the case in mountainous regions, where the mosaic 

is intricate and the difficulty is thus enhanced. Contrast for instance the geologic 

map of the Great Plains and that of the Rocky Mountains. 

The scale of the geologic map of North America is limited by the great scope of 

the map. Being continental, the scope demands a scale represented by 1 divided 

by millions, and considerations of convenience led the compilers to fix on 1 :5,000,000, 

or approximately 1 inch to 80 miles. One-twentieth of an inch being about as 

narrow a band of color as can be read distinctly, 4 miles is nearly the narrowest 

zone of rocks that can be represented without exaggeration. Many zones narrower 

than 4 miles are of such importance that they must be represented even though 

exaggerated, but not many adjacent bands can be so treated. The scale therefore 

imposes severe limitations on classification. 

As the limitations are more severe in mountains than in plains a refined set of 

geologic divisions which can be delineated for plains will be impracticable in mountains, whereas that series of terranes which is practicable for the former is likely 

to be much too comprehensive for the latter. In maps of moderate scope these 

differences are usually adjusted in such a manner that a uniform classification may 

be employed over the entire map; but where the scope is continental the differences 

become so great that a uniform classification for the continent becomes unsatisfactory. Even though the natural geologic divisions are the same, they must be 

grouped or separated according to the requirement that the map shall show all 

possible detail and yet be legible. Cambrian, Ordovician, Silurian, Devonian, and 

Carboniferous must be distinctly mapped and to some extent individually subdivided in eastern North America; but on the scale adopted they must be grouped 

where they are upturned on the flanks of the Rocky Mountains. Thus a uniform 

classification is impracticable for the geologic map of North America, and an elastic 

or varied classification is required by the conditions of printing and legibility 

inherent in the scale. 

Knowledge contrasted with ignorance imposes a similar condition. In reconnaissance surveys major divisions only are distinguished, and these often but 

vaguely or along a narrow line of route. There are large areas of North America 

regarding which present knowledge is no more precise. Within or adjoining these 

regions are districts of greater or less extent which have been surveyed in detail. 

The boundaries of these districts may be those of a State or Province, or those of 

an arbitrary quadrangle. They are sharply defined. Beyond them lies comparative ignorance; within them is displayed the key to an understanding of what the 

unknown probably is. In depicting the well-known and the little--known side by 

side on the same map, we can not use one classification for both, without great loss 

in the one or certainty of error in the other. The only alternative is to map each 

according to our knowledge of it, using for the well-known district a detailed classification up to the limit set by the scale of the map and for the little-known region a 

generalized classification adapted to our ignorance. This method has been adopted 
GEOLOGIC DIVISIONS MAPPED. 9 

in the map of North America, wherever the differences of knowledge are of such a 

degree as to occasion material difficulties in applying a uniform classification. The 

instances are readily recognized by the arbitrary boundary which separates several 

formations or series from a comprehensive major class that comprises them all. 

Each such occurrence points to an opportunity for investigation. 

The legend of the map in detail is as follows: 

Color, cream. 

Symbol, 1. 

Ql'ATER~ARY. 

Distribution: Shown only where the Quaternary completely conceals the underlying formations. 

Content: .r\Jluvial, lacustrine, and desert-basin deposits, glacial drift (in small part only), and 

beach, dune, and marine deposits of the Atlantic and Gulf coasts; all comprised in one category (Quaternary) and shown by the one color and pattern. 

Color, lemon-yellow. 

Symbol, 2. 

PLIOCENE. 

Di,stribution: The Pliocene is distinguished on the Atlantic and Gulf coasts, so far as surveys permit, in California, and in northern Nevada. Elsewhere on the map it is classed with the 

Quaternary (1), as in the valley deposits of the Great Basin; or with the Miocene under the 

heading "Later Tertiary" ( 4). The Lafayette formation of the Atlantic and Gulf slopes, 

including the Altamaha of Georgia, is shown only where it completely conceals the underlying formations. 

Content: Marine Pliocene of the Coast Ranges of California; Humboldt formation (nonmarine) 

of Nevada; marine Pliocene and Lafayette of the Atlantic and Gulf slopes east of the Mississippi, including Altamaha of Georgia; also Yucatan. 

Color, light yellow. 

Symbol, 3. 

MIOCENE. 

Distribu,tion: The Miocene is separately indicated on the Pacific coast and on the Atlantic and 

Gulf coasts, so far as surveys permit. Elsewhere on the map it is comprised with Pliocene 

under the term "Later Tertiary" (4). 

Content: Monterey shale and equivalents of the Pacific coast; beds of Carrizo Creek, California; 

and marine Miocene of the Atlantic and Gulf coasts. Does not include so-called "Arctic 

:Miocene" nor" Old Miocene," both of which arc included in the "Marine Eocene." 

LATER TERTIAllY (MIOCENE AND PLIO( J<'NE). 

Color, yellow. 

Symbol, 4. 

Distribution: Mapped where Miocene or Pliocene are recognized but can not be separated or be 

individually identified in the present state of knowledge. 

Content: Pacific coast marine deposits; Alaskan Ar{\tic coastal plain deposits; fluviatile and lacustrine beds of the Interior; western Gulf coast marine formations; and late marine Tertiary 

of l\Iexico, Centra.! America, and South America. 

Color, light orange (ruling). 

Symbol, 5d. 

MARINE OLIGOCENE. 

Di8tribution: Atlantic and Gulf coasts of the United States, where it is separated from the 

Eocene. Elsewhere combined with the Eocene as "Earlier Tertiary." 

Content: Marine Oligocene of the Atlantic and Gulf slopes. 
10 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Color, light orange (dots). 

Symbol, 5c. 

CONTINENTAL OLIGOCENE. 

Distrib11tion: Great. Plains of Wyoming, the Dakotas, and Colorado. 

Content: White River group, including Chadron and Brule formations. 

EARLIER TEHTIARY (EOCENE AND OLIGOCENE). 

Color, orange (horizontal ruling). 

Symbol, 5. 

Distribution: Central America, West Indies, and Pacifie coast to Alaska. Mapped separately on 

the Atlantic and Gulf eoasts, in Greenland, and in the Interior. 

Content: Marine Eocene and Oligocene formations of Central America and West Indies; eorre~ 

sponding marine formations on the Pacifie coast of California and Oregon; and eoal~bearing 

formations of Puget Sound (Puget group) and Alaska (Kenai formation). 

Color, orange (vertical ruling). 

Symbol, 5b. 

MARINE EOCENE. 

Distribution: Atlantic and Gulf coasts, Mississippi embayment, Jamaica, and Greenland, where 

it is separated from Oligocene. Elsewhere mapped with Oligocene as "Earlier Tertiary." 

Content: l\Iftrine Eocene of the Atlantic and Gulf coasts, Jamaica, and Greenland, and estuarine 

deposits of the .Mississippi embayment. 

Color, orange (dots). 

Symbol, 5b-l. 

CONTIKENTAL EOCENE. 

Distribution: Interior basins of the western United States and Canada. 

Content: Puerco, Fort Union, Wasatch, Green River, Bridger, and Uinta formations. 

Color, orange-brown. 

Symbol, 5a. 

EARLIEST TERTIAHY OR LATEST CRETACEOUS. 

Distribution: Colombia, middle western United States, and Canada. 

Content: Shoshone group; Denver and Arapahoe and equivalents in Colorado; 11 Upper 

Laramie," Lance formation, 11 Cera tops beds," or 11 Somber beds" in Wyoming, Montana, 

and the Dakotas; and Edmonton of Alberta; also 11 Upper Laramie" of Canadian reports. 

In Colombia, the Guaduas or Cerro de Oro formation. 

Color, yellowish green. 

Symbol, 6. 

LATE UPPER CRETACEO"GS j LARAMIE. 

Distribution: Rocky Mountains of the United States, southern Wyoming to New Mexico. 

Content: Late Cretaceous coal-bearing formations; Laramie of the Denver Basin; "Lower 

Laramie" of southern 'Vyoming; and coal-bearing equivalents in Colorado and New 

Mexico. 

Color, light green. 

Symbol, 7. 

UPPER CRETACEOUS. 

Distribution: South America and West Indies; present. but not generally distinguished in 

Mexico from Lower Cretaceous; Atlantic and Gulf coasts from Mexican boundary to New 

England; the Interior province, New Mexico to Mackenzie; Pacific coast, Lower Cali~ 

fornia to Alaska; the Arctic coastal plain of Alaska; and the west. coast of Greenland. 
GEOLOGIC DIVISIONS MAPPED. 11 

Content: Marine and coastal-plain deposits of the Atlantic and Gulf coasts and West Indies, 

comprising Raritan to Manasquan, New Jersey; Black Creek ("Bladen") and Peedee 

("Burches Ferry"), North Carolina; Tuscaloosa to Ripley, Alabama; and the Gulf series 

(Woodbine toN avarro) of Texas and Louisiana. In Mexico, included on map with Lower 

Cretaceous (8). Marine and coastal-plain deposits of the Interior, Dakota to Fox Hills, 

inclusive, and equivalents. Marine deposits of the Pacific coast, Chico and its equivalents. 

Laramie and coal-bearing portion of the Montana of the Rocky Mountains and Great 

Plains mapped separately. 

MONTANA, COAL-BEARING PORTION. 

Color, olive-green. 

Symbol, 7a. 

Distribution: Rocky Mountains and northern Great Plains of the United States and Canada. 

Content: Middle Montana, generally coal bearing; Mesaverde of New Mexico, Colorado, and 

southern Wyoming; Eagle, Claggett, and Judith River of northern Wyoming and Montana, 

and their equivalents in Canada. 

LOWER CRETACEOUS. 

Color, medium green. 

Symbol, 8. 

Distribution: Atlantic, Gulf, and Caribbean coasts, Now Jersey to South America; Pacific 

coast, Alaska to South America. In Mexico, areas mapped include Upper Cretaceous. 

Content: Potomac group of the Atlantic slope, Georgia, and eastern Alabama; Comanche series; 

(comprising Trinity, Fredericksburg, and Washita groups) of Texas, Oklahoma, and 

Mexico; Shasta series (Knoxville and Horsetown formations) of California and Oregon; 

Queen Charlotte group of British Columbia; Kootenai formation of the Rocky Mountains, 

Montana northward to fifty-second parallel and beyond; Lower Cretaceous, Alaska. 

TRIASSIC AND JURASSIC. 

Color, dark greenish blue. 

Symbol, 9. 

Distribution: Middle western United States, Rocky Mountains, and High Plateaus, Montana 

to Arizona; western United States and eastern Alaska, where Triassic and Jurassic can 

not be separated or can not be separately identified. 

Content: Red beds and marine deposits of the Cordillera, comprising Jurassic, Triassic, and 

Permian, where more or less certainly known to be present but not distinguishable, or too 

small to map separately; marine Triassic and Jurassic of the Pacific where not separated. 

Color, greenish blue (horizontal ruling). 

Symbol, 9a. 

JURASSIC. 

Distribution: Central America, Mexico, California, Oregon, Alberta, and parts of Alaska. 

Content: Jurassic limestone and shale of Nevada; Mariposa slate, Sierra Nevada; Franciscan 

formation, Coast Range, California; Jurassic of Mexico; Chinitna shale and Tuxedni 

sandstone (" Enochkin formation"), also the Naknek formation, of Alaska Peninsula. 

The Jurassic of the Humboldt Range, Nevada, and the marine Sundance formation of the 

Rocky Mountains are not distinguished on the map from Triassic, as the areas are too 

small to distinguish the system separately. 

Color, dark green (horizontal ruling). 

Symbol, 10. 

TRIASSIC. 

Distribution: Central America, Mexico, New Mexico, and Texas; Nevada and California; 

British Columbia and Alaska; Atlantic slope from North Carolina to Nova Scotia. 
12 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Content: Marine Triassic of western Nevada and California; marine Triassic of Zacatecas and 

red beds in Mexico; red beds of Texas and New Mexico; Newark group, North Carolina 

toN ova Scotia; marine Triassic of the Arctic. In the Canadian Rockies the marine Triassic 

is mapped with the "Paleozoic, undivided" (19, 20). In Oregon, Idaho, middle western 

United States, and part of Alaska the Triassic is combined on the map with Jurassic (9). 

Color, light gray. 

Symbol, 11. 

PERMIAN. 

Distribution: Southwestern United States; West Virginia, Ohio, and Pennsylvania; New 

Brunswick and Nova Scotia. Elsewhere mapped with "Carboniferous, undivided." 

Content: Permian limestone and red beds, Kansas to Texas; Permian red beds, New Mexico; 

Opeche and Minnekahta formations, Black Hills; Dunkard group of the northern Appalachians; red and gray sandstones and subjacent New Glasgow conglomerate of New 

Brunswick, Nova Scotia, and Prince Edward Island. Includes some Triassic red beds in 

mappmg. 

Color, dark gray. 

Symbol, 12. 

PENNSYLVANIAN. 

Distribution: Guatemala, central and eastern United States, New Brunswick, and Nova Scotia. 

Present, though not distinguished from Mississippian, throughout the Cordillera, the 

Arctic region, and N owfoundland. 

Content: "Coal measures" (Pottsville to Monongahela, inclusive) of eastern North America and 

their equivalents where distinguished; Carboniferous limestone of Guatemala. Mapped 

elsewhere with "Carboniferous, undivided" (14). 

Color, light French blue. 

Symbol, 13. 

MISSISSIPPIAN. 

Distribution: Guatemala; eastern North America from Oklahoma to Nova Scotia; present but 

included in the "Carboniferous, undivided," in the Cordillera, Arctic region, and Newfoundland. 

Content: "Lower Carboniferous" limestones and their equivalents where they are separated 

on the map from coal measures of the Pennsylvanian. In Guatemala the Santa Rosa 

formation. 

Color, light blue. 

Symbol, 14. 

CARBONIFEROUS, UNDIVIDED. 

Distribution: Western North America, Arctic region, Newfoundland, and Central America; 

subdivided into Mississippian, Pennsylvanian, and Permian in eastern North America. 

Content: Mississippian and Pennsylvanian limestones of the Cordillera including Devonian 

where present; Mankomen formation and N abesna limestone of Alaska; Lisburne formation, Alaska; Carboniferous of the Parry Archipelago, Arctic; Carboniferous of Newfoundland; doubtful Carboniferous or Devonian of Honduras. 

Color, dark blue. 

Symbol, 15. 

DEVONIAN. 

Distribution: Eastern central United States and eastern Canada; Cordillera of the United States, 

Canada, and Alaska; northwestern Canada. 

Content: Devonian as commonly defined through the Appalachians, including Helderberg at 

the base and higher formations to Chemung and Catskill, inclusive; in the northeast, from 

Gaspe to New York, Helderberg is included with the Silurian in mapping; in the Appalachian zone south of latitude 38° the Devonian color on the map includes Silurian; throughout tho Cordillera from Mexico to Alaska the Devonian where present is mapped with 

''Carboniferous, undivided" (14), except that it is distinguished in the Klamath Mountains, California. 
Coler, violet. 

Symbol, 16. 

GEOLOGIC DIVISIONS MAPPED. 

SILURIAN. 

13 

Distribution: General throughout northern and eastern North America east of the Great Plains; 

represented by the Devonian color (15) in the Appalachian zone south of latitude 38°; 

known to be present in the Cordillera and Alaska but not generally distinguished by separate color, except in Mexico, Nevada, and British Columbia. 

Content: In the Appalachians in general includes Medina to Cayuga; in the southern Appalachians is mapped with Devonian; in eastern Canada and New York Helderberg is included 

on the map; in the Interior strata of Niagara age; in the Arctic, the Silurian color covers 

areas of the limestone series, known to include Ordovician and Silurian. 

Color, light bluish purple. 

Symbol, 17. 

MIDDLE AND UPPER ORDOVICIAN. 

Distribution: General throughout the continent. In the Arctic mapped with the Silurian (16); 

in the Rocky Mountains of the United States included in narrow bands of Cambrian and 

lower Ordovician (18). 

Content: Middle to uppermost Ordovician (Chazy to Richmond, inclusive). 

Color, purplish red. 

Symbol, 18. 

CAMBRIAN AND LOWER ORDOVICIAN. 

Distribution: General throughout the continent. 

Content: In general comprises Lower Cambrian (Georgian) to Lower Ordovician (Beekmantown), inclusive, or so much as may be present. In Appalachian zone, Virginia to Alabama, 

includes conformable formations below the Olenellus zone; Ocoee ana. Chilhowee groups 

of Safford and other terranes. In the Cordillera, includes Upper Ordovician and Silurian 

where they are present and bands of color are too narrow for distinct mapping. 

Color, light reddish purple. 

Symbol, 19. 

PALEOZOIC, UNDIVIDED. 

Distribution: Little-known regions of the northern Cordillera, Montana, and Canada. 

Content: Paleozoic in general, where data do not suffice to map the divisions separately. Includes 

some known marine Triassic in the Canadian Rockies. 

METAMORPHIC PALEOZOIC, UNDIVIDED. 

Color, light reddish purple with light dashes. 

Symbol, 20. 

Distribution: Venezuela, Cuba, Santo Domingo, Porto Rico; northeastern Appalachian region; 

northern Cordillera, California to Alaska. 

Content: Metamorphic sedimentary rocks of known or supposed Paleozoic age, together with 

possibly pre-Paleozoic schists and some igneous intrusive rocks, which have not been 

separated. Includes some known marine Triassic in the Canadian Rockies. 

LATE (?) PRE-CAMBRIAN (UNCLASSIFIED, LITTLE ALTERED). 

Color, light brown with blue hachures. 

Symbol, 21. 

Distribution: Northern Canada (Labrador to Northwest Territories excluding the Lake Superior 

region); Avalon Peninsula, Newfoundland; Nova Scotia; Uinta and Wasatch ranges, 

Utah; Needle Mountains, Colorado. 
14 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Content: In Canada, sandstones and lava flows that are little disturbed or altered but have no 

fossils, "Cambrian" of Canadian reports, sometimes tentatively correlated with the Kewee-

'nawan series or with the Animikie group (Upper Huronian); Athabasca-N astopoka series 

of Adams; gold-bearing Meguma series of Nova Scotia; Random and older formations of 

the Avalon group of Newfoundland; quartzites of Uinta and Wasatch ranges of Utah 

(mapped under Belt series); Needle Mountains group of Colorado (mapped under Belt 

series). 

Color, light brown. 

Symbol, 2la. 

BELT SERIES. 

Distribution: Western Rocky Mountains of Idaho, Montana, British Columbia, and Alberta. 

Content: The Belt series (late Algonkian) of Idaho, Montana, British Columbia, and Alberta. 

(The quartzites of the Uinta and Wasatch mountains of Utah and the Needle Mountains 

group of Colorado, which are regarded as possible equivalents of the Belt series, have also 

been included under this color on the map, as has the Cherry Creek group of Montana, 

which is probably of early Algonkian age.) 

KEWEENAWAN. 

Color, light brown with red dashes. 

Symbol, 2lb. -

Distribution: Lake Superior region, Ontario, Minnesota, Wisconsin, and Michigan. 

Content: Keweenawan lava flows and sediments, within the area known to be of Keweenawan 

age; also "Nipigon" series, but not including possible equivalents in other districts. Areas 

mapped include intrusive igneous rocks. 

UPPER HURONIAN (OF THE LAKE SUPERIOR REGION). 

Color, brown (vertical ruling). 

Symbol, 2lc. 

Distribution: Lake Superior region; Ontario, Minnesota, Wisconsin, and Michigan. 

Content: Animikie and equivalents in the Lake Superior region only. Areas mapped include 

intrusive igneous rocks. 

EARLIER ( ?) PRE-CAMBRIAN (UNCLASSIFIED, MUCH ALTERED). 

Color, brown with white dashes. 

Symbol, 22. 

Distribution: Canada in general outside of the districts specially classified; Nova Scotia and 

Newfoundland; Cherry Creek group of Montana (probably of early Algonkian age, mapped 

under Belt series, late Algonkian). 

Content: Metamorphosed sediments and volcanics, in places richly iron bearing, widely distributed throughout the Canadian shield, and commonly classed as "Huronian;" in Montana the Cherry Creek group (probably early Algonkian), which is mapped under Belt 

series, late Algonkian. 

Color, dark reddish brown. 

Symbol, 22a. 

HASTINGS AND GRENVILLE. 

Distribution: Eastern Canada, Ontario, and Quebec; probably present but not distinguished 

on the map in Adirondack region, K ew York. 

Content: Limestone and associated rocks of the Hastings and the Grenville series in the type 

areas. 
GEOLOGIC DIVISIONS MAPPED. 

Color, brown with red dashes. 

Symbol, 22b. 

MIDDLE AND LOWER HURONIAN. 

15 

Distribution: Lake Superior region; Ontario, Minnesota, South Dakota, Wisconsin, and Michigan. 

Content: Sedimentary and intrusive rocks in the Lake Superior region only; Sioux quartzite of 

South Dakota and Baraboo quartzite of Wisconsin. Areas mapped include intr1.1sive 

igneous rocks. 

Color, pink and red hachures. 

Symbol, 23. 

"LAURENTIAN" (CANADIAN USAGE). 

Distribution: Throughout Canada and the Arctic. 

Content: Gneisses and associated plutonic rocks throughout Canada, the Laurentian of Canadian geologists; included in Archean of Dana. (Areas of undifferentiated pre-Cambrian 

in Michigan, Wisconsin, Minnesota, and ~orth Dakota have also been mapped under this 

color.) 

LAURENTIAN (OF THE LAKE SUPERIOR REGION). 

Color, pink with red hachures. 

Symbol, 23d. 

Distribution: Wisconsin, Michigan, and Minnesota. 

Content: Acidic plutonic rocks intrusive in Keewatin, separately indicated only within the 

United States. 

Color, dark red with white hachures. 

Symbol, 23a. 

KEEWATIN. 

Distribution: Lake Superior region; Ontario, Michigan, Minnesota, and Wisconsin. 

Content: Oldest pre-Cambrian of the Lake Superior region. Largely basic lavas. 

Color, pink with red dashes. 

Symbol, 23b. 

UNDIFFERENTIATED PRE-CAMBRIAN. 

Distrihution: Appalachian province, Vermont to Alabama; Missouri, Texas, Arizona, New 

Mexico, California, and the Rocky Mountains of the United States; in Michigan, Wisconsin, Minnesota, and North Dakota is mapped under " 'Laurentian' (Canadian usage)." 

Content: Gneisses known to be of pre-Cambrian age, but not otherwise correlated;. included in 

Archean of Dana. Includes plutonic igneous rocks where not separately mapped, and 

some sediments of Paleozoic age. 

GNEISSES, SCHISTS, AND METAMORPHOSED SEDIMENTS (SUPPOSED PRE-CAMBRIAN j POSSIBLY IN 

PART PALEOZOIC AND MESOZOIC). 

Color, pink with blue dashes. 

Symbol, 23c. 

Distribution: In the Cordillera from South America to Alaska. 

Content: Highly metamorphosed schists and associated plutonic rocks, apparently of great 

antiquity but not known to be pre-Cambrian; possibly in part Paleozoic or Mesozoic. 

Color, dark violet. 

Symbol, 24. 

PRE-CAMBRIAN INTRGSIVE ROCKS. 

Distribution: Plutonic igneous rocks in eastern Canada, eastern United States, and Oklahoma. 

Includes some effusive rocks of same age. Elsewhere mapped with associated preCambrian rocks. 
16 INDEX TO 'l'HE STRATIGRAPHY OF NORTH AMERICA. 

Oolor, dark red. 

Symbol, 24a. 

POST-CAMBIUAK INTRUSIVE ROCKS. 

Distribution: The Cordillera from South America to Alaska; Santo Domingo; eastern United 

States, New Brunswick, Nova Scotia, and Newfoundland. 

Content: Plutonic rocks of all kinds, chiefly granites, occurring in masses of sufficient size to be 

mapped. Mostly of Paleozoic and Mesozoic age. Includes some effusive rocks of same 

age and some older intrusives. Tertiary intrusives mapped with "Tertiary and later 

effusive rocks." 

Oolor, scarlet. 

Symbol, 25. 

TERTIARY AND LATER EFFUSIVE ROCKS. 

Distribution: Volcanic rocks and lava flows, chiefly of Tertiary age, of the Cordillera from Central America to Aleutian Islands; Venezuela and Windward Islands; Greenland and 

Iceland. Includes some intrusive rocks of same age. 

In applying the preceding legend to the map adjustments to scale and to 

knowledge have been made by the compilers, but adjustments of classifications 

adopted by different surveys could be made only by authority of the responsible 

officers, and to bring them about has necessitated correspondence or required special 

conferences. The classification of the pre-Cambrian was discussed at two formal 

conferences at which the Canadian and Federal surveys were represented, with 

results that are stated in Chapter II. 

Some other difficult questions may be enumerated here. 

In applying the distinction indicated by the categories 23b and 23c, the compilers have placed in the former all areas where Cambrian sediments rest unconformably upon the pre-Cambrian. In 23c are classed those areas which contain 

highly metamorphic rocks overlain by later Paleozoic or Mesozoic strata and which 

may include masses that were deposited and metamorphosed in some post-Cambrian 

epoch. This is the case throughout the Cordillera, except in the southwestern 

United States. 

The "Archean" of the southern Appalachian Mountains has been separated 

by Keith into undifferentiated pre-Cambrian, pre-Cambrian intrusives, and postCambrian intrusives. The undifferentiated pre-Cambrian is carried northward 

through New Jersey, New York, and New England to the international boundary. 

In the Adirondacks this division presumably comprises the "Laurentian" of 

Canada and also the Hastings and Grenville representatives. 

The pre-Cambrian rocks of Sutton Mountain, Quebec, are mapped as igneous 

and undifferentiated pre-Cambrian, after Dresser. The distinction can not yet be 

carried across the international boundary. 

The Random formation of Newfoundland is placed in the late pre-Cambrian 

by vValcott, and the rest of the Avalon group is mapped with it. 

The gold-bearing Meguma series of Nova Scotia is classed as pre-Cambrian 

on the recommendation of C. K. Leith and because of the resemblance which the 

rocks bear to the A val on group of Newfoundland, as noted by Selwyn, Murray, 

Howley, and Faribault. 

The Belt series, though regarded as Cambrian by R. A. Daly, is retained in 

the Algonkian in accordance with the observations of vVillis, confirmed by the later 

work of Walcott. 
GEOLOGIC DIVISIONS MAPPED. 17 

Most of the Paieozoic in New England is represented as undivided, because the 

metamorphism which the rocks have suffered has so far prevented recognition of 

divisions. In northwestern Maine it is rather the drift covering and the monotony 

of the black slates of the several terranes distinguished in Canada that has interfered 

with mapping. 

In the northern Cordillera from Idaho to Alaska the unknown or little-known 

strata are generally classed as Paleozoic, but the few areas that have been worked 

up in detail indicate that the region really is a fine mosaic of many formations. 

In the West Indies and in Venezuela the pre-Mesozoic sediments are classed 

as Paleozoic. 

The systems of the lower Paleozoic (Cambrian and Ordovician) can not be 

mapped on this scale as separate terranes divided by the boundary which paleontologists have generally recognized, for the line in many areas falls in a great thickness of limestone which is not readily divisible. It has been found practicable to 

distinguish Cambrian and lower Ordovician from middle and upper Ordovician, 

the former including all below the Chazy and its equivalents, whereas the latter 

takes in the Chazy and all later Ordovician terranes. 

The Helderberg of the New York and eastern Canada sections is classed as 

Devonian in the text and in the legend but is included with Silurian on the map. 

The difference arises from the facts that the Geological Survey of Canada has not 

yet recognized the Devonian age of the Helderberg and that the United States 

Geological Survey has only recently done so. The map would in most places not 

be perceptibly changed, however, by shifting the lines to accord with the text. 

In the eastern United States the Carboniferous is readily divisible and the 

divisions (Mississippian, Pennsylvanian, and Permian) are easily shown upon the 

map. In western North America the Carboniferous has a different development 

and the areas are, moreover, too small to be subdivided on the scale of this map. 

Thus, although the equivalents of the Mississippian and Pennsylvanian are known 

in western North America, they are not separated on the map. 

The Permian is not yet clearly distinguished from the older Carboniferous in 

some areas or from the Triassic in others. The adjustment of uncertainties can 

best be followed by referring to the authors quoted in the chapters on the Carboniferous and Triassic. 

The Triassic of the Arctic is mapped according to Schei and extended to the 

Cape Rawson beds, which lie in the strike. 

The Jurassic occupies but very small areas. Although it is widely represented 

in the central Rocky Mountains and thence northward, it occurs in such narrow 

belts that it can not be mapped separately from the Triassic in that province. It 

was not possible. to insert another band of color between those representing the 

Triassic and Cretaceous. 

The line between Jurassic and Cretaceous in the Coast Range of California is 

drawn by different observers below the Franciscan, at the base of the Knoxville, 

or in the upper part of the Knoxville. The mapping expresses the line at the base 

of the Knoxville, the only one that can be readily traced. 

48011°-12-2 
FIGURE 1.-Sketch map showing the distribution of post-Cambrian intrusive rocks represented on the geologic map 

of North America. 

18 
FIGURE 2.-Sketch map showing the distribution of Tertiary and later effusive rocks represented on the geologic 

map of North America. 

19 
20 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The distinction between Upper and Lower Cretaceous in the United States is 

based on the natural divisions which are regarded as characteristic of North American Cretaceous. The Mexican Survey recognizes a threefold division, Eo-, Meso-, 

and N eo-Cretaceous, which is adjusted to European standards but which can not 

yet be carried out on the geologic map of Mexico, because not enough detailed work 

has been done in that country. The Lower Cretaceous is most widely distributed 

in Mexico, and the areas which are colored accordingly include also those of the 

Upper Cretaceous. 

The line of division between the Cretaceous and Tertiary is everywhere in 

doubt from South America to Canada. The positions of the Laramie and its supposed equivalents and of those formations which have been placed in the Shoshone 

group of Cross have been controverted and are still matters of opinion. The data 

for the map assembled by the most recent work of the United States Geological 

Survey in Utah, Colorado, Wyoming, and Montana were compiled by Willis, who 

placed the Laramie in the Cretaceous, in accordance with the decision of the Survey, 

and assigned the Shoshone group to the "Paleocene," after Scott. "Paleocene" 

has not, however, been accepted by the Survey's committee on geologic names, 

and the group is here described as "earliest Tertiary or latest Cretaceous." The 

Canadian Survey stated that the corresponding line in western Canada should be 

drawn at the base of the Edmonton. 

Many other questions will present themselves to the student, who is referred 

to the text for the data on which the map is constructed. 

As this work includes no chapters describing the igneous rocks, figures 1 and 2, 

showing the distribution, as indicated on the geologic map, of the post-Cambrian 

intrusive rocks and the Tertiary and later effusive rocks, respectively, are inserted 

here. With the post-Cambrian intrusive rocks are included extrusive rocks of the 

same age, and with the Tertiary effusives are included associated intrusive rocks. 

ACKNOWLEDGMENTS. 

The chapters have been read by geologists of the United States Geological 

Survey and revised in accordance with their suggestions. The writer owes special 

acknowledgment to Messrs. C. D. ·walcott, Charles Schuchert, E. 0. Ulrich, and 

A. W. Grabau, who have read the citations on the lower Paleozoic; to Mr. E. M. 

Kindle, who read the Silurian and Devonian chapters in the original and also in 

the revised drafts; to Messrs. G. H. Girty, David -White, and G. H. Ashley, for 

criticism of the Carboniferous chapters; to Mr. J. Perrin Smith, for revision of the 

Triassic chapter; to Mr. T. W. Stanton, for revision of the Jurassic and Cretaceous 

chapters; to Mr. F. H. Knowlton, for comments on Mesozoic paleobotany; to Mr. 

W. H. Dall, for consideration of the several chapters on the Tertiary; and to Mr. 

T. vVayland Vaughan, for contributions to the discussion of the Tertiary of the 

Atlantic, Gulf, and West Indian provinces. 

The suggestions made by these able critics have been followed so far as the 

scope of the work permitted, but the responsibility for the substance and form 

of the text rests none the less with the compiler. 

The preparation of the manuscript geologic map has been difficult and tedious. 

It is a task requiring peculiar skill and experience to prepare suitable copy of so 
-----------------------------------

COLOR SCHEME. 21 

complex a map and to engrave and lithograph it according to the high standards 

of modern cartography. The writer has been fortunate in being associated with 

the Survey's editor of geologic maps, Mr. G. Vv. Stose, and aided by the chief 

engraver, Mr. S. J. Kubel. To them in particular and also to Mr. H. S. Selden, 

who drew the manuscript geologic map, and to the cartographic section of the 

Survey he would express his indebtedness. 

The names of the contributors to the map are given in the list at the close of 

this introduction. There are, however, certain portions of the geologic map which 

are strikingly different from any previously published and which represent original 

contributions from geologists who are familiar with special districts. These 

contributions are especially acknowledged as follows: 

Mr. Robert T. Hill prepared an original map of Sonora and Chihuahua, Mexico, 

and of portions of adjacent areas in the United States. 

Messrs. T. W. Vaughan and A. C. Spencer furnished the map of Cuba according 

to published data and their own unpublished notes. 

Mr. ·w. P. Blake supplied material for the little-known districts of Arizona 

and his map was adjusted to notes and maps supplied by other geologists. 

Mr. Ralph Arnold prepared for the geologic map of North America issued 

by the International Geological Congress in 1906 the map of California south of San 

Francisco, and for the map accompanying this volume Mr. Robert Anderson reviewed 

this material and supplemented it from his own notes. 

Mr. A. C. Lawson supplied a manuscript map of the northern Coast Ranges, 

which was adjusted to other data in hand. 

Mr. T. ·wayland Vaughan and Mr. L. W. Stephenson drew the map of the 

Atlantic and Gulf coastal plains according to cooperative work in progress in the 

several States. 

Mr. Arthur Keith prepared the map of the Appalachian Mountains from 

Maryland to Georgia, east of the Appalachian Valley, after his own surveys, supplemented by the original work of other geologists. 

Messrs. George Otis Smith and E. S. Bastin compiled the map of the New 

England region from surveys by several geologists, supplemented by their own 

original notes. 

Mr. N. H. Darton, Mr. M. R. Campbell, and the geologists assisting Mr. Campbell supplied the data for the Mesozoic and Tertiary of Colorado, Wyoming, and 

Montana. 

COLOR SCHEME. 

PRINCIPLES. 

Color is used on geologic maps to delineate the distribution of various rocks. 

Legibility is the first requirement, economy in printing the second, and good taste 

the third. Custom may prescribe certain associations of color with particular 

implications, which, being thus established, control other associations. 

The requirement of legibility determines the first principle. Distinctions 

of color should be so marked as to be clearly recognized. As contrast depends 

on hue and tint or shade in flat colors, and also on pattern where devices are 

employed, distinctions of hue, tint, shade, or pattern may be used to produce it. 
22 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

In order to discuss contrasts it is necessary to have in mind certain facts about 

colors. There are three primary colors-red, blue, and yellow, which may be more 

accurately spoken of in terms of pigments as crimson lake, cobalt blue, and cadmium yellow. If pairs of these colors are combined in equal volumes they yield 

the standard secondary colors purple, orange, and green. Again if the standard 

secondaries are mixed in equal volumes in pairs standard tertiary colors are 

obtained-russet from purple and orange; olive from purple and green; and citrine 

from orange and green. Red predominates in russet, blue in olive, and yellow 

in citrine; each primary forms one-half of the respective tertiary color, but the 

presence of the other two primaries modifies its brilliancy. 

Although the above statements are true in a general way, they are not mathematically exact. A name does not define a color. There are various reds, blues, 

and yellows, and various secondaries and tertiaries result according to the choice 

of primaries with which to start. Given three primaries, however, corresponding 

standard secondaries and tertiaries may be produced in the manner above described. 

If graduated proportions are mixed instead of equal parts a series of slightly 

differing tints are obtained. For instance, 9 volumes of red to 1 of blue, 8 of red 

to 2 of blue, 7 of red to 3 of blue, and so on to 1 of red to 9 of blue will yield a range 

of purples which are scarcely distinguishable one from the next, yet which run the 

gamut from red to blue. A similar range of greens from blue to yellow and one 

of oranges from yellow to red complete a circle of closely graded secondaries. 

The tertiary mixtures may be graded in the same manner to produce a 

sequence of russets, olives, and citrines which range from purple through green 

and then through orange back to purple without a break. 

If we call the primary, secondary, and tertiary colors thus mixed hues, we 

may distinguish tints and shades of any one of them. The normal hue has the full 

available strength of its constituent colors. A tint is lighter. It may be mixed 

by adding more of the medium, water or oil, or by adding white. On the other 

hand a shade is darker-that is, it reflects less light than the normal hue. It may 

be produced by adding black, but more artistically by mixing a complementary 

tertiary color with the normal hue. In color printing tints result where the white 

of the paper shines through the hue, which is thereby diluted, and shades are 

produced by overprinting grays, which are usually tints of olives or russets strong 

in blue. 

Contrast depends on the juxtaposition of unlike hues. It is strongest between 

any two of the pure primaries. It is equally striking but less likely to be offensive 

between a primary and the secondary which is composed of the other two primaries. 

Contrast in general is less pronounced between secondary hues and is materially 

less between tertiaries. There is no stronger contrast than that of white and black; 

in relation to colors it enters in a subdued degree into the distinction between tints 

and shades. Hence where ~trong contrast is desired we may juxtapose primary 

hues, or a primary with its complementary secondary, or a light tint of a hue against 

a dark shade of the same or another hue. The requirement of distinctness may 

usually be met by lesser contrasts and in general the greater contrasts are reserved 

for small areas or for emphasis. 
COLOR SCHEME. 23 

A second principle follows from the requirement of economy in printing: The 

color scheme should be devised to accomplish the required distinctions with the 

least practicable number of impressions or printings. 

As the lithographic press prints but one color at a time, it might seem that 

there must be as many printings as colors; but printing one color over another 

has the effect of combining them as if they were mixed and therefore a small number 

of printings may yield many distinctions. In colored illustrations three colorsred, yellow, and blue or green-usually suffice, reinforced sometimes by black. 

On assuming that we proceed with the three primaries, it is evident that by 

overprinting we may obtain the three secondaries and also one combination of all 

three primaries in the full strength of their several hues. This combination will 

be almost black. These seven effects are strong unmodified hues. To produce 

tints the lithographer substitutes fine lines or dots in place of flat colors. Many 

of the patterns employed are almost invisible, but they permit the white of. the 

paper to shine through and lighten the hue. Several distinct tints of any one 

primary hue may be produced at one printing, and their various combinations constitute a wide range of secondaries and tertiaries. Only an experienced lithographer 

can know in advance what the effects of the combinations will be and how distinct 

they will be. They fall into groups and of each group some are too closely similar 

to one another for practical distinction and others are undesirable because they are 

distasteful. But a large number of good distinctions is possible with three printings, the number is very greatly increased by a fourth printing, and only very 

numerous and very refined differences require many printings. The geologic colors 

on the map of North America are produced by 12 printings, which yield 42 distinct 

effects. Two more printings are required for the black and blue of the base map. 

Conspicuous patterns are more or less used in geologic maps and greatly increase 

the range of recognizable distinctions. They are, however, a concession to technical requirement and offend good taste unless they are very skillfully designed. 

The third requirement, that of good taste, is commonly little considered, but 

if it is satisfied the prime requirement of proper distinctness will also have been 

met; for the essential of good taste is adaptation to purpose. In general it may 

be said that pleasing maps result from an association of light tints, particularly 

light tints of tertiary hues in large areas, with appropriate contrasts of bright 

primary or secondary hues which may be proportionately more brilliant as the 

areas covered by them are smaller. 

USAGES. 

If entire freedom of choice and arrangement in devising a color scheme is 

allowed, the principles stated above may easily be applied in most cases to produce 

a thoroughly satisfactory map; but usage has established certain associations of 

colors with definite meanings, and it is misleading to contravene those associations. 

Whether the difficulty thus occasioned in the mind of a reader is such as to overbalance the advantages that may be gained by using colors arbitrarily instead of 

according to custom is determinable only with reference to each particular case and 

is then often a matter of personal judgment. 
24 INDEX TO THE STRATIGRAPHY OF NORTH AM.I£RICA. 

Some familiar usages are those of red, the color of fire, for igneous rocks; pink 

for the ancient crystalline rocks; blue, the color of the rock, for limestone; yellow, 

by similar association, for sandstone; and many others in which the suggestion of 

the color has a mnemonic value. 

Another class of usages comprises those established officially by the practice 

of a government survey or by agreement among such surveys. Among those which 

have been developed to meet a general application and which are therefore most 

comprehensive in character, there are two that have been considered for the map. 

of North America-the color scheme- adopted by the International Geological 

Congress for the general map of Europe, and that designed by the United States 

Geological Survey for the Geologic Atlas of the United States. The following 

table shows their resemblances and differences: 

Colors and color schemes. 

Umt{'cl States Geological Survey 

Natural order of tmts, hues, and 

shades 

InternatiOnal Euro- ------~-----,------------

pean color scheme Geologic Atlas of the Umtcd Geologic map of Nmth 

States Amenca 

Yellow orange-tinted (cream) .. _ Quaternary-_ .. ____ _ __ -- __ - ___ - __ - Yellow, hght ................... Phocene .... _______ ----- _______ _ 

Yellow, medmm ............... Mwcene ........... ----- ______ ---- ___ _ Yellow, dark ........ __________ Oligocene. _____ . __ Phoccne and Mwcene _ .. . Yellow, greenish. ____ -._--.-.-_ -.. __ .. _____ -.. __ . _ _ .. ______________ . ____ . 

Cttrme, yellowJBh brown ... ___ - __ -. ______ -- .. __ . __ . Eocene and Oligocene ... . 

Citnne, medmm brown ....... Permian ................................... . Cttrine, greemsh brown ........................... Cretaceous, upper part ... . Green, yellowish ................ Eocene .................................. . Green, hght ................... Cretaceous, Upper ...................... . Green, medmm. . . . . . . . . . . . . . . Cretaceous, Lower.. Cwtaccous........... . .. Green, dark .................. Wealden .......... Cretaceous, lower pait ... . Green, bluish.................. Volg1an...... . . . Jurassic ................. . Ohve, greenJBh .............. Cambnan (dark) ............................. . Ohve, medmm... .. . . . . . . . . . . Devoman (dark) .... Archean ................ . Ohve, bluish............... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 

Quaternary 

Mwcen{' 

Plio<:ene 

CretaceouR, late Upper 

Cretaceous, Upper 

Cretaceous, Lower 

Tnass1c 

Blue, greemsh................ Stlurian (dark)...... Tnassic ................. g~~!::~~ ~l~~hPurassic (dark) 

Blue, gray.................. Carbomferous (dark) Carbomferous ........... {~=~~~~v~~~~ (dark) 

Blue, hght .................. Jurass16, Upper ..... Carbomferous, upper pait. Carbonitcrous 

Blue, medmm ................ ._ Jurassic, Middle... Carbomferous, lower part .. Mississippmn 

Blue, dark.............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Devonian 

Blue, purphsh................ Jurassw, Lower .............. ~ . . . . . . . . . . Ordovwmn, middle and upper 

Purple, bluiSh........... . . . . . TnasRIC. . . . . . . . . . . Devoman ............. _.. S1lunan , Purple, hght... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Paleozoic 

Purple, medmm. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... Purple, dark................ . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . EruptiVcs 

Purple, reddiSh ................ Gnc1ssand·protogmc Silunan ................. Cambnan and lower Ordovician. 

Russet, purplish .................................. Ordov1ctan (reddish) ..... . Russet............. .. . . . . . . . . ................ Algonkian ............. Late pre-Cambrian 

Russet, reddish...... . . . . . . . . EruptiVes.... . ......... •. . . . . . . . . . . . . . . . . Ear her pre-Cambrian 

Reel, russet........ . . . . . . . . . . . . . . . . . . . . . . . . . . . Cambnan ........... _ Red, hght. . . . . . . . . . . . . ...... _ Schists .. :.......... . . . . . . . . . . .... . Pre-Cambnan. 

Red, med1um.................. . ................................... _ .. . Red, clark.................. . Eruptlves......... . ..................... Eruptives. 

Red, yellowish........ . . . . . Etfusives.... . . . . . . .. . . .......... . Orange, reddish.............. . Effusives. . . . . . . . ............. . Orange, mcdmm...... . . . . . . . Effus1ves ........ _ . . ........ . Orange, hght....... . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . ..... . Orange, yellowish.............. . . . . . . . . . . . . . . . . . . . . . . . . ...... . 

Effusives. 

Eocene 

Oligocene. 
COLOR SCHEME. 25 

The European international geologic color scheme embodies the results of prolonged consideration by the international committee who were charged by the 

Geological Congress with the duty of preparing the map of Europe. In it can be 

recognized some elements of the French usage, particularly in the colors employed 

for the Mesozoic and Tertiary terranes. German influence appears in the selection of 

tones for Paleozoic terranes, and the familiar association of gray with Carboniferous 

and of pink with the ancient crystalline schists is an obvious result of general practice. So also is the use of strong, brilliant colors for the igneous rocks. The writer 

is not definitely informed regarding the discussion of principles through which 

the result was reached, but by a study of the color schemes in the light of what is 

published concerning the controlling principles, it would seem that the committee 

recognized (1) established usage, (2) the order of prismatic colors from purple 

through blue and green to yellow for that portion of the scheme relating to the 

Triassic and post-Triassic terranes, and (3) the arbitrary principle that Mesozoic 

terranes should be distinguished from Paleozoic by a very decided contrast of light 

and shade, the Paleozoic terranes being indicated by dark colors. 

The European color scheme is exceedingly well adapted to delineate the geology 

of Europe and would apply well to that portion of western North America in which 

the Mesozoic and Tertiary formations occupy large areas in contrast to the Paleozoic 

terranes, as they do in Europe also. The map of Europe is very clea; and legible, 

the base map having been kept free from confusing details and the colors having 

been selected and printed with great skill. The color scheme thus commends 

itself through the beautiful appearance of the map. It must not be forgotten, 

however, that Europe presents a special form of geologic structure. The continent 

is made up of extensive areas of Mesozoic and Tertiary strata surrounding relatively small exposures of Paleozoic terranes. This arrangement of younger strata 

about older nuclei is, from the point of view of the cartographer, the most important 

feature which the continent presents. The committee with good reason sought to 

emphasize the fact, and through that emphasis the map of Europe gains in expression 

and educational value. The greater part of the map is easily legible, being covered 

only by the light colors which are used for the Mesozoic and Tertiary, and the 

difficulties which arise in attempting to read the geology of the minor Paleozoic 

areas are not forced upon the attention. 

But the international color scheme is unfitted to lands in which the Paleozoic 

terranes predominate and are minutely subdivided, for the density of the colors 

selected for the Paleozoic would produce a map that would offend good taste and 

be illegible. Moreover, inasmuch as the range of prismatic colors from purple, blue, 

and green to yellow is preempted in the European color scheme for Mesozoic and 

Tertiary terranes and the reds are assigned to the ancient crystalline and eruptive 

rocks, the choice of colors remaining available for the Paleozoic is much too limited 

for satisfactory discriminations. This is at once evident on an examination of the 

Paleozoic areas as represented on the international map-such, for instance, as the 

coal fields of Belgium and France, or the peninsula of Brittany, or Wales and Scotland. Although the distinctions are limited to a few great systems they are reco ~\CAL S(j~ 

nizable only on close inspection and the areas are indistinguishable from one ano f(..~ ~ 

C) Q~~~ B~\ \ 't1~ ~\)G \\'( ~ 

\ \,.\fO?.~ ~§ 

G'~OLOG\C fiJ"' 
26 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

at a little distance. A geologic map of eastern North America printed in these 

dark colors with so little difference of hue or shade would fail to present adequately 

the great Appalachian zone as distinguished from the broad plateaus of the coal 

measures and the domelike uplifts of the Cincinnati axis. In the pre-Cambrian also 

the number of formations recognized in North America is greatly in excess of those 

distinguished in Europe, and the simplicity of the European scheme renders it 

insufficient to delineate the geology of the Lake Superior region and the Canadian 

shield. 

For these reasons, after very careful consideration, the compilers of the geologic 

map of North America found it necessary to abandon the European international 

scheme not only for the map issued by the International Geological Congress in 

1906 but also for the map accompanying the present volume. 

The color scheme adopted by the United States Geological Survey for the 

Geologic Atlas of the United States is based on three essential principles-(1) that 

the order of the colors shall be that of their natural association, (2) that there 

shall be a standard color for each of the great geologic periods, and (3) that subordinate distinctions under each color shall be obtained by the use of obvious 

patterns. To these may be added the practice of using dull, subdued tones for 

the sedimentary and brilliant colors for the igneous rocks, as well as the mnemonic 

association of patterns which assigns parallel lines to the sedimentary rocks, angular 

patterns to igneous rocks, hachure patterns to metamorphic rocks, and dotted 

patterns to the surficial deposits. This color scheme has been developed and 

applied in the office and engraving division of the United States Geological Survey, 

where special facilities and skill in technical processes have been available. In 

attempting to apply the scheme to geologic maps printed under contract with 

private firms, difficulties have been encountered both in technical execution and 

in cost. Experience shows that the applicability of any color scheme which requires 

a precise use of patterns is affected by the necessity of developing a different use of 

patterns to secure economy in printing. For this reason primarily the color scheme 

of the United States Geological Survey is unavailable in general practice. 

As color schemes that employ definite associations of colors and time divisions 

are limited in application to provinces that have had a certain historic development, 

and as patterns that may occasion excessive cost are unpractical, it follows that 

neither of these usages can be adopted for a universal color scheme except to a 

qualified degree. Nevertheless, a color scheme which shall serve as the universal 

language of geologic cartography is extremely desirable. The writer has sought, 

therefore, to devise certain principles which would occasion as little departure from 

current usage as might be practicable and which should yet be of general application 

in all continents. The adoption of such general principles would not find favor in 

England, France, or Germany, as may readily be foreseen if we consider how long 

established the several usages of those countries are; nor can it hope to supersede 

the international color scheme already applied to a large part of the geologic map 

of Europe and to be extended to the incomplete portions of the map. But Europe 

represents only a small part of the earth's surface and the Americas, Africa, and 

Asia need not be governed by its practice. It may be hoped that in making local 
COLOR SCHEME. 27 

geologic maps of other continents than Europe, even European cartographers will 

strive toward uniformity of expression, especially in color schemes, and that the 

American nations which are not yet committed by established practice to diverse 

usages will unite upon common principles. 

In order to promote this desirable end, the following principles, suggested by 

the writer, have been proposed by the United States Geological Survey for discussion with a view to the development of a common usage among the official surveys 

of the Americas and for application to the geologic maps of the world published 

on the standard 1:1,000,000 base. These principles have already been indorsed 

in a general way by the Geological Survey of Canada and the Instituto Geologico 

de Mexico. 

PRINCIPLES FOR COLORING GEOLOGIC MAPS. 

The first principle shall be that the relations of color and relative age shall be 

invariable-that is, when applied to distinguish divisions of a sequence of strata, 

colors shall always be used in a definite succession which shall express relative age. 

Let it be agreed that the sequence red, purple, violet, blue, green, and yellow 

shall be adopted to represent succession of formations, groups, or series of sedimentary rocks from older to younger and let the order of colors be invariable according to the principle stated above, no matter what part or how much of the geologic 

column is represented. Then red will always represent something older than that 

which is shown in purple, or violet, or blue, etc. Blue will always stand for something older than that shown in green or yellow. In looking at any geologic map 

thus colored the student would at once know which were the older and which the 

younger sedimentary rocks. The essential features of sequence and structure 

would be immediately obvious. 

The second principle is that color and geologic time divisions shall be measurably independent; in other words, no color shall be regarded as precisely indicative 

of any particular time division. 

This principle is a radical departure from general usage in any one of the several 

countries which have well-established color schemes, but it is simply a recognition 

of general practice if we take account of the differences of these established schemes. 

For instance, in Europe blue means Jurassic, but in the United States it stands for 

Carboniferous. Thus blue in each country represents something different, and to 

a student of one country examining the maps of the other it suggests something 

other than it should. Let us agree that blue shall not necessarily mean Jurassic 

or Carboniferous, but that it may represent either Jurassic or Carboniferous, or in 

general some Mesozoic or Paleozoic time division. Such an agreement will give 

that elasticity of usage which is essential to a general color scheme designed for 

application to different provinces. If applied with appropriate recognition of the 

first principle the elasticity thus introduced will not occasion confusion, because 

we will always know the relative age of those formations represented by blue as compared to those represented by green on the one side and violet on the other. Indeed, 

a certain orderliness will take the place of the disorder that is forced by arbitrary 

usages upon any student of the maps of several countries. This principle is not 

intended, however, to give license to use any color whatever for any period, nor to 
28 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

contravene the principle of utility, which requires that a color scheme for a given 

province shall be as nearly uniform as practicable. 

To illustrate the application of the first and second principles that have been 

proposed, we may consider certain examples. A general geologic map of North 

America requires few distinctions in the Mesozoic but many in the Proterozoic, 

Paleozoic, and Cenozoic. We may therefore allot the colors as follows: 

Cenozoic ______________ {{Gy ellow. 

reen. 

Mesozoic _________ - _ _ _ j Blue. 

p 1 . Violet. 

a eo zOic ______________ {Purple. 

Proterozoic__ _ _ _ _ _ _ _ _ _ _ Red. 

A general geologic map of Europe makes different requirements-very few distinctions in the Proterozoic, few in the Paleozoic, but very many in the Mesozoic 

and Cenozoic. Hence for such a map we may allot the colors as follows: 

rYellow. 

Cenozoic ______________ - -~lGreen. 

Mesozoic _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Blue. 

Paleozoic ________________ {PViole

1

t. 

urp e. 

Proterozoic _______________ Red. 

The braces are overlapped to avoid too precise an assignment-for it is the 

purpose of the second principle to preserve that elasticity which alone can make 

the scheme available everywhere. Yet through the first principle we secure an 

orderly sequence, which will always convey the idea of relative age. 

The preceding considerations apply to general maps on a small scale, for 

instance, the accompanying geologic map of North America, or maps on the scale of 

1:1,000,000, the standard international base. A cartographer having such a map 

to construct should consider the geologic development of the province which the 

map is to represent in whole or in part and should devise the application of his 

color scheme in such a way that it accords with the two principles suggested and 

yet gives the greatest range of colors where there is the greatest development of 

the geologic column. 

Detailed maps, on larger scales than 1:1,000,000, present special conditions; 

they may be simple or comprehensive. 

If they are simple, it is desirable that the colors used should correspond with 

those that represent the same general time divisions on the general map. ·where 

one or two effects suffice for the latter, there may be two or three times as many 

on the simple detailed map, but the range of colors may not need to be greatly 

increased. 

If the detailed map shows terranes that are greatly subdivided, the range of 

colors must be increased; but in that case the dominant effects may be and should 

be selected to correspond with colors indicating the general time divisions on the 

general map arid only so many of the colors above and below as may be needed 

should be used. The reader will then know that (a) if warm ruddy tones predominate, the earlier periods are represented; (b) if cold blue tones are most evident, 
COLOR SCHEME. 29 

the rocks of middle geologic periods are shown; and (c) if bright greenish or yellowish tones prevail, the map indicates rocks of later geologic periods. If the greens 

are wanting, so that the yellow tones are in contact with blues, he will recognize 

a hiatus; and similarly if any other color in the sequence is omitted. 

The first and second principles discussed above embody the essential suggestions for a general color scheme, but there are other considerations which may be 

stated as supplementary rules that are at least desirable. Thus, in regard to contrasts, if we recognize pure hues, tints, shades, and tertiary hues, as explained on a 

previous page, we may provide that the invariable sequence of colors shall apply 

equally to pure hues, tints, shades, and tertiary hues; that pure, brilliant hues 

shall as a rule be reserved for igneous rocks; and that shades and tints belonging 

to a single minor division of the color sequence shall preferably be so used that 

darker effects represent the lower and lighter effects the upper terranes, in such 

manner that gradations from dark to light correspond with conformable sequences 

and contrasts indicate systemic distinctions, so far as practicable. 

These provisions establish certain usages which have become common-the 

use of strong, bright effects for igneous rocks as contrasted with subdued effects 

for sedimentary rocks, and the employment of darker tones for the older and 

lighter tones for the younger divisions of a group or series. They support the 

first principle but emphasize contrast. 

Contrast is as necessary to good geologic coloring as harmony. The eye catches 

a line between contrasted values and identifies the horizon in the various associations 

that may be occasioned by complex structures. Among the contrasts available 

for mapping sedimentary rocks, those which occur between light tints of one hue 

and dark shades of the next hue in the natural order of colors are the most useful 

and most consistent with harmony. 

With regard to patterns we may recognize that they are desirable in many 

cases, for they afford distinctions that otherwise may not be clearly made, and if 

used consistently they serve to suggest at once the igneous, sedimentary, metamorphic, or surficial character of the rocks. But as patterns may be costly and 

unless skillfully employed fail in desirable effects, we may agree that the use of 

patterns shall not be obligatory, yet that if visible patterns are used, it shall be 

according to an established classification. The experience of the United States 

Geological Survey indicates that this classification should be patterns in circular 

figures for surficial rocks, patterns in parallel lines for sedimentary rocks, patterns 

in hachures for metamorphic rocks, and patterns in angular figures for igneous 

rocks. Patterns so used must be such as are obvious to the eye at the usual reading 

distance for which the map is designed. The use of patterns that are not obvious 

but may be seen on close inspection is a method of combining colors to economize 

in printing and may modify the mnemonic suggestion of the origin of the rock. 

For instance, by close examination of many of the patterns employed for sedimentary rocks on the accompanying map of North America, it will be seen that 

they are made up of crossed lines which would suggest igneous rocks, but these 

patterns 'are so fine that they will not be seen at the distance at which the map will 

ordinarily be read if hung upon the wall. Where conspicuous patterns are employed, 

either in parallel lines or in hachures, they signify the character of the rock. 
30 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Although for some maps these visible patterns may be costly there may also 

be economy in their use, as stated below. A consideration which rises to the importance of a principle in devising any general color scheme relates to economy. 

Economy in reproduction is usually secured by limiting the number of printings. 

There are two ways in which this may be done-(a) by using patterns of one color 

which produce distinctions of tint; (b) by overprinting two or more colors. In 

applying the former method the preparation of a lithographic stone so that it shall 

print many devices in one color, yet shall give different effects, may occasion greater 

cost than would be involved in printing from two or more simpler stones. In 

applying the second method, the combinations secured by overprinting two or 

more colors are numerous and may be less monotonous than those obtained by 

patterns of one color. The lithographer has always to balance the cost of preparing 

stones and that of printing, and the calculation of least expense involves not only 

the number of effects required but also the size of the edition and other factors. 

The conditions vary with individual maps, and an economical color scheme for 

general use must permit the employment of either or both methods. 

By coloring geologic maps according to the proposed principles, we may secure 

(a) legibility, because the invariable order of colors will indicate the order of age; 

(b) common usage of colors within limits, which may be wide, for freedom is imperative, but which are nevertheless significant; (c) recognition of customary usages 

that now exist but are often disregarded; and, consequently, (d) the equivalent of 

a universal language in the coloring of all maps that follow the accepted principles. 

The accompanying geologic map of North America represents an application 

of the proposed principles to a general case of great complexity. It is hoped that 

it may serve to encourage consideration and adoption of a universal color language 

on geologic maps. 

CONTRIBUTORS. 

The list of contributors to the geologic map of North America and of the sources 

from which it has been compiled follows.a 

In this list are included the names of authors of geologic maps, published and 

in manuscript, used in compiling the map of North America, and those who furnished data, published and unpublished, for the correction of previously existing 

maps, or contributing to the knowledge of little-known regions. The sources of 

information from which published maps were originally derived are not given except 

where specifically credited on the maps. The term "folio" in the citations refers 

to the Geologic Atlas of the United States, published by the United States Geological Survey. 

Adams, F. D. 

Member of the committee on pre-Cambrian nomenclature. 

Data on Victoria, Peterborough, and Hastings counties: Ann. Rept. Geol. Survey Canada for 1892-93, vol. 6, 

Rept. J. 

Montreal sheet: Ann. Rept. Geol. Survey Canadu for 1894, vol. 7, Rept. J. 

Geologic map of Laurentian area north of the Island of Montreal: Ann. Rept. Geol. Survey Canada for 1895, 

vol. 8, Rept. J. ------ -------- -----~----

a This list has been prepared by G. v\'. Stose and (for the Canadian contributors) J. M. Nickles, from notes and lists 

by Bailey Willis and the Canadian Geological Survey and from other sources. 
CONTRIBUTORS. 31 

Adams, F. D.-Continued. 

Data on Haliburton district, Ontario: Summ. Rept. Geol. Survey Canada for 1899, pp. 122-131 (with A. E. Barlow). 

Data on Haliburton and Bancroft areas, Ontario: Summ. Rept. Geol. Survey Canada for 1901, pp. 145-148. 

Geologic map of Island of Montreal and vicinity: Ann. Rept. Geol. Survey Canada for 1901, vol. 14, pt. 0 (with 

0. E. LeRoy). 

Geologic map of central Ontario: Proc. Roy. Soc. Canada, 3d ser., vol. 2, sec. 4, p. 3, 1908 (with A. E. Barlow). 

Geologic map of Haliburton and Bancroft areas, Ontario: Mem. Geol. Survey Canada No. 6, 1910 (with A. E. 

Barlow). 

Adams, G. I. 

Geologic map of the Ozark region of Missouri and Arkansas: Twenty-second Ann. Rept. U. S. Geol. Survey, pt. 2, 

1901, pp. 69-94. 

Geologic map of Louisiana and eastern Texas: Bull. U. S. Geol. Survey No. 184, 1901. 

Geologic map of part of the eastern Choctaw coal field, Oklahoma: Twenty-first Ann. Rept. U. S. Geol. Survey, 

pt. 2, 1901, pp. 257-311 (with J. A. Taff). 

Fayetteville folio, Missouri-Arkansas (with E. 0. Ulrich). 

Adan de Yarza, Ramon. 

Geologic map of Cuba: Bol. Com. del Mapa Geol. de Espana, vol. 20, 1895, pp. 71-88. 

Aguilera, J. G. 

Furnished geologic map of Mexico compiled for the map of North America published by the International Geological Congress, 1906, and later compiled manuscript maps of parts of Mexico for the present map. 

Alden, W. C. 

Chicago folio, Illinois-Indiana; Milwaukee folio, Wisconsin (with T. C. Chamberlin). 

Corrections to southeastern portion of geologic map of Wisconsin published in 1881, from unpublished notes on 

this area. 

Ami,H.M. 

Manuscript contributions; Paleozoic formations of St. Lawrence Valley. 

Anderson, F. M. 

Notes on the Cretaceous of California, used by Ralph Arnold and Robert Anderson in compilation of map of California: Proc. California Acad. Sci., 3d ser., Geology, vol. 2, 1902, pp. 1-154. 

Anderson, Robert. 

Compiled manuscript geologic map of Coast Ranges of California south of San Francisco, for this m~p. 

Geologic maps of Santa Maria and Coalinga districts, Cal.: Bull. U.S. Geol. Survey Nos. 322, 1907, and 398, 1910 

(with Ralph Arnold). 

Manuscript geologic maps of parts of Diablo Range and Salinas Valley region, California. 

Arnold, Ralph. 

Compiled manuscript geologic map of Coast Ranges of California south of San Francisco for map of North America 

published by International Geological Congress, 1906; used in part in this map. 

Geologic map of part of Olympic Peninsula, Washington: Bull. Geol. Soc. America, vol. 17, 1906, pp. 451-468. 

Santa Cruz folio, California (with J. C. Branner and J. F. Newsom). 

Geologic maps of Santa Clara Valley, Puente Hills, and Los Angeles oil districts (with G. H. Eldridge); of Summerland district; of Santa Maria and Coalinga districts (with Robert Anderson), and McKittrick-Sunset region 

(with H. R. Johnson): Bull. U.S. Geol. Survey Nos. 309, 321, 322, 398, and 406. 

Manuscript geologic maps of San Luis Obispo County, Santa Monica and Pasadena quadrangles, and part of San 

Diego County, Cal. 

Ashley, G. H. 

Compiled detailed map of the Pennsylvanian and Permian series in the Appalachian region, from northern Pennsylvania to Alabama. 

Notes on the distribution of the Pennsylvanian series in the Appalachian and central coal fields. 

Ditney folio, Indiana (with ~f. L. Fuller). 

Atwood, W. W. 

Data on Alaska Peninsula, used in compiling manuscript map of Alaska. 

Bailey, L. W. 

Data on Queens, Sunbury, and York counties, New Brunswick: Rept. Prog. Geol. Survey Canada for 1872-73, 

pp. 180-230 (with G. F. Matthew). 

Data on New Brunswick: Rept. Prog. Geol. Survey Canada for 1874-75, pp. 84-89 (with G. F. Matthew). 

Data on southern New Brunswick: Rept. Prog. Geol. Survey Canada for 1870-71, pp. 13-240; idem for 1875-76, 

pp. 348-368 (with G. F. ~iatthew); idem for 1878-79, Rept. D (with G. F. Matthew and R. W. Ells). 

Data on Albert and Westmoreland counties, New Brunswick: Rept. Prog. Geol. Survey Canada for 1876-77, 

pp. 351-395, with geologic map of lower Carboniferous rocks (with R. W. Ells). 

Data on and geologic map of Carleton, Victoria, York, and Northumberland counties, New Brunswick: Ann. 

Rept. Geol. Survey Canada for 1885, vol. 1, Rept. G. 

Geologic map of southwestern Nova Scotia: Ann. Rept. Geol. Survey Canada for 1892-93, vol. 6, Rept. Q; idem 

for 1896, vol. 9, Rept. M. 

Data on the pre-Silurian of southern New Brunswick: Rept. Prog. Geol. Survey Canada for 1877-78, Rept. DD. 
32 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Ba.iley, L. W.-Continued. 

Data on York and Carleton counties, New Brunswick: Rept. Frog. Geol. Survey Canada for 1882-84, Rept. G; 

Summ. Rept. idem for 1900, pp. 146-150. 

Geologic map of Victoria, Northumberland, and Restigouche counties, New Brunswick: Ann. Rept. Geol. Survey 

Canada for 1886, vol. 2, Rept. N (with IY. Mcinnes). 

Data on northern New Brunswick and adjacent areas in Quebec and in ~Iaine: Ann. Rept. Goo!. Survey Canada 

for 1887-88, vol. 3, Rept. 11 (with.W. Mcinnes). 

Bain, H. F. 

Geologic map of Illinois, compiled by Stuart Weller: Bull. State Geol. Survey Illinois No. 6, 1907. 

Geologic map of the zinc and lead region of the upper Mississippi Valley: Bull. U.S. Goo!. Survey No. 294, 1906. 

Ball, M. W. 

Data on Little Snake River coal field, Wyoming·, used in compiling map of the Cretaceous and Tertiary. 

Geologic map of eastern part of Little Snake River coal field, Wyoming: Bull. U. S. Geol. Survey No. 381, 1910, 

pp. 186-213 (with E. Stebinger). 

Geologic map of western part of Little Snake River coal field, Wyoming: Bull. U. S. Geol. Survey No. 341, 1909, 

pp. 243-255. 

Ball, S. H. 

Geologic map of southwestern Nevada and adjacent parts of California; Bull. U.S. Geol. Survey No. 308, 1907. 

Manuscript geologic map of part of Silver City quadrangle, New Mexico. 

Bancroft, Howland. 

Geologic map of part of Yuma County, western Arizona: Dull. U. S. Geol. Survey No. 451, 1911. 

Bancroft, J. A. 

Data on coast of British Columbia from Powell River to Kingcome Inlet: Summ. Rept. Geol. Survey Canada for 

1907, pp. 16-18. 

Barbour, E. H. 

Notes on details of geology in Nebraska. 

Bard, D. C. 

Unpublished notes on details of lava of Snake River Plains, Elko County, Nev. 

Barlow, A. E. 

Data on Haliburton district, Ontario: Summ. Rept. Geol. Survey Canada for 1896, pp. 43-53; idem for 1899, pp. 

122-131 (with F. D. Adams). 

Data on Hastings and Renfrew counties, Ontario: Summ. Rept. Geol. Survey Canada for 1897, pp. 44-56. 

Geologic map of Nipissing district, Ontario, and Pontiac County, Quebec: Ann. Rept. Geol. Survey Canada for 

1897, vol. 10, Rept. I. 

Data on Temagami district, Ontario and Quebec: Summ. Rept. Geol. Survey Canada for 1903, pp. 120-133; idem 

for 1904, pp. 190-194; idem for 1906, pp. 113-118. 

Geologic map of Sudbury mining region, district of Algoma, Ontario: Ann. Rept. Geol. Survey Canada for 1901, 

Rept. H. 

Lake Timiskaming sheet, Ontario-Quebec: Geol. Survey Canada, 1907. 

Geologic map of central Ontario: Proc. Roy. Soc. Canada, 3d ser., vol. 2, sec. 4, 1908, p. 3 (with F. D. Adams). 

Geologic map of Haliburton and Bancroft areas, Ontario: Mem. Geol. Survey Canada No. 6, 1910 (with F. D. 

Adams). 

Barlow, Scott. 

Data on Springhill coal field, Cumberland County, Nova Scotia: Rept. Frog. Geol. Survey Canada for 1873-74, 

pp. 147-160; idem for 1875-76, pp. 343-347. 

Barnett, V. H. 

Data on Smith River coal field, Montana, and on Cheyenne River and Standing Rock Indian reservations, South 

and North Dakotu, used in compiling map of the coal-bearing Cretaceous and Tertiary. 

Bascom, Florence. 

Philadelphia and Trenton folios, Pennsylvania and New Jersey, and manuscript maps of neighboring regions. 

Bastin, E. S. 

Geologic map of New England, compiled by G. 0. Smith and E. S. Bastin for geologic map of North America, 

Intern. Geol. Congress, 1906. 

Geologic map of the granites of Maine: Bull. U.S. Geol. Survey No. 313, 1906 (with G. 0. Smith and C. W. Brown). 

Geologic map of part of southern Maine: Dull. U. S. Geol. Survey No. 420, 1910. 

Penobscot Bay and Rockland folios, southeastern Maine, and manuscript maps of adjacent areas in Maine. 

Manuscript geologic map of the Eastport quadrangle, ~Iaine. 

Bauerman, Hilary. 

Data on country near forty-ninth parallel of north latitude west of the Rocky Mountains: Rept. Frog. Geol. 

Survey Canada for 1882-84, Rept. B. 

Bayley, W. S. 

Passaic folio, New Jersey, and manuscript for Raritan folio. 
CONTRIBUTORS. 33 

Becker, G. F. 

Data on Kodiak Island used in compiling manuscript map of Alaska. 

Geologic maps of the quicksilver districts of the Pacific slope: Mon. U. S. Geol. Survey, vol. 13, 1888. 

Beede, J. W. 

Cottonwood Falls folio, Kansas (with C. S. Prosser). 

Beekly, A. L. 

Data on Glenwood Springs coal field, Colorado, and on Cheyenne River and Standing Rock Indian reservations, 

South and North Dakota, used in compiling map of the coal-bearing Cretaceous and Tertiary. 

Bell, J. :M. 

Data on country from Great Bear Lake to Great Slave J_,ake: Ann. Itept. Geol. Survey Canada for 1899, vol. 12, 

Rept. C. 

Bell, Robert. 

Data on Manitoulin Islands: Rept. Prog. Geol. Survey Canada for 1863-1866, pp. 165-169; idem for 1866-1869, 

pp. 109-116. 

Data on country northwest of Lakes Superior and Nipigon: Rept. Prog. Geol. Survey Canada for 1866-1869, 

pp. 313-364. 

Data on region north of Lake Superior between Nipigon and Michipicoten rivers: Hept. Prog. Geol. Survey Canada 

for 187D--7l, pp. 322-351. 

Data on country between Lake Superior and Albany River, Ontario: Rept. Prog. Geol. Survey Carmela for 1871-72, 

pp. 101-114. 

Data on country between Lake Superior and Lake Winnipeg: Rept. Prog. Geol. Survey Canada for 1872-73, 

pp. 87-111. 

Data on country between Red River and south Saskatchewan, and region between Lake Superior and Red River: 

Rept. Prog. Geol. Survey Canada for 1873-74, pp. 66-90. 

Data on country west of Lake Manitoba and Winnipegosis, and vicinity of Lake Winnipeg: Rept. Prog. Geol. 

Survey Canada for 1874-75, pp .. 24-56. 

Data on country between James Bay and Lakes Superior and Huron: Rept. Prog. Geol. Survey Canada for 1875-76, 

pp. 294-342. ' 

Data on region north of Lake Huron and east of Lake Superior: Rept. Prog. Geol. Survey Canada for 1876-77, 

pp. 193-220. 

Data on east coast of Hudson Bay: Rept. Prog. Geol. Survey Canada for 1877-78, Rept. C. 

Data on country between Lake Winnipeg and Hudson Bay: Rept. Prog. Geol. Survey Canada for 1877-78, Rept. 

CC (with geologic nmp). 

Geologic map of the Lake of the Woods region, Ontario: Rept. Prog. Geol. Survey Canada for 188{}--1882, Rept. C. 

Data on basin of Athabasca River, Alberta: Rept. Prog. Geol. Survey Canada for 1882-1884, Rept. CC. 

Data on Labrador coast, Hudson Strait, and Hudson Bay: Rept. Prog. Geol. Survey Canada for 1882-1884, 

Rept. DD. 

Data on Hudson Strait and Hudson Bay: Ann. Rept. Geol. Survey Canada for 1885, vol. 1, Rept. DD. 

Data on Attawapishkat and Albany rivers, Lonely Lake to James Bay: Ann. Rept. Geol. Survey Canada for 1886, 

new ser., vol. 2, Rept. G. · 

Geologic map of Algoma and Nipissing districts, Ontario: Ann. Rept. Geol. Survey Canada for 189{}--91, vol. 5, 

Rept. F. 

French River sheet, Ontario: Ann. Rept. Geol. Survey Canada for 1896, vol. 9, Rept. I. 

Geologic map of northern side of Hudson Strait: Ann. Rept. Geol. Survey Canada for 1898, vol. 11, Rept. M. 

Data on Michipicoten district, Ontario: Summ. Rept. Geol. Survey Canada for 1898, pp. 99-106; idem for 1900, 

pp. 109-121. 

Data on Churchill and Nelson rivers and around God's and Island lakes: Rept. Prog. Geol. Survey Canada for 

1878-79, Rept. C. 

Data on region west of Hudson Bay: Rept. Prog. Geol. Survey Canada for 1879-80, Rept. C. 

Geologic map of Moose River basin: Rept. Prog. Geol. Survey Canada for 188{}--82, Rept. C. 

Data on Great Slave Lake region, Northwest Territory: Summ. Rept. Geol. Survey Canada for 1899, pp. 

103-110. 

Geologic map of basin of Nottaway River: Ann. Rept. Geol. Survey Canada for 1900, vol. 13, Rept. K. 

Cobalt mining district, Ontario: Summ. Rept. Geol. Survey Canada for 1905, pp. 94-104; idem for 1906, pp. 

llD--112. 

l\[anuscript geologic map of Newfoundland, furnished by Geological Survey of Canada for the map of North 

America published for the International Geological Congress, Mexico, 1906. 

Berry, E. W. 

Data on the Cretaceous of Maryland, Delaware, New Jersey, Pennsylvania, \'irginia, North Carolina, South Carolina, Georgia, and Alabama and the Tertiary of Alabama and Mississippi, used in the compilation of the map 

of the Atlantic and Gulf Coastal Plain. 

48011°-12--3 
34 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Bibbins, A. B. 

Data on the Cretaceous of Maryland, Delaware, New Jersey, Pennsylvania, Virginia, and North Carolina, used 

in compilation of the map of the Atlantic Coastal Plain. 

Blackwelder, Eliot. 

Data on Yakutat Bay and Alsek River region, used in compiling manuscript map of Alaska, making use of earlier 

work of I. C. Russell. 

Laramie-Sherman folio, Wyoming (with N. II. Darton and C. E. Siebenthal). 

Blake, W. P. 

Manuscript map of southern Arizona, used in part. 

Bose, E. 

Geologic map of Chiapas and Tabasco: Bol. Inst. geol. Mexico No. 20, 1905. 

Boutwell, J. M. 

Geologic map of the Bingham district, Utah: Prof. Paper U.S. Geol. Survey No. 38, 1905 ( .vith Arthur Keith). 

Manuscript map of Park City district, Utah, on file in office of U.S. Geol. Survey. 

Bowman, Amos. 

Geologic map of Cariboo mining district, British Columbia: Ann. Rept. Geol. Survey Canada for 1887-88, vol. 3, 

pt. 1, Rept. C. 

Bownocker, J. A. 

Geologic map of Ohio, based on maps by Newberry and Orton, Ohio Geol. Survey, 1909. 

Branner, J. C. 

Geologic map of Arkansas: Am. Jour. Sci., -ith ser., vol. 2, 1896, pp. 229-236. 

Map of novaculite area, central Arkansas: Third Ann. Rept. Geol. Survey Arkansas, 1890 (with L. S. Griswold). 

Santa Cruz folio, California, and manuscript maps of San Jose and Mount Hamilton quadrangles, used in compilation by Ralph Arnold and Robert Anderson. 

Brock,R. W. 

Member (part of the time) of committee on classification of the pre-Cambrian. Furnished geologic map of Canada 

compiled for the map of North America published by the International Geological Congress, 1906, and later notes 

and sketch maps for the present map. Adjusted several points which arose between the Canadian and United 

States surveys. · 

Data on West Kootenay district, British Columbia: Summ. Rept. Geol. Survey Canada for 1898, pp. 62-71; idem 

for 1899, pp. 75-86; idem for 1900, pp. 62-84. 

Data on the Boundary Creek district, British Columbia: Summ. Rept. Geol. Survey Canada for 1901, pp. 49-67; 

idem for 1902, pp. 92-138. 

Data on the Lardeau mining district, British Columbia: Summ. Rept. Geol. Survey Canada for 1903, pp. 42-81; 

idem for 1904, pp. 80-91; idem for 1907, pp. 84-90. 

Data on Rossland mining district, British Columbia (preliminary report): Geol. Survey Canada, 1906. 

West Kootenay sheet, British Columbia: Ann. Rept. Geol. Survey Canada for 1901, vol. 14 (portfolio) (with R. G. 

McConnell). 

Geologic map of Canada, including Labrador and Newfoundland, scale 100 miles to 1 inch (accompanies a descriptive sketch of the geology and economic minerals of Canada, by G. A. Young): Geol. Survey Canada, 1909. 

Brooks, A. H. 

Furnished geologic map of Alaska compiled from published maps and manuscript data. 

Data on southeastern Alaska, upper Tanana and White River basins, Susitna basin, Alaska Range, Seward Peninsula, and Yukon-Tanana region (the last based on earlier work of Spurr), used in compiling manuscript map 

of Alaska. 

Buckhannon folio, West Virginia (with J. A. Taff). 

Brown, C. W. 

Penobscot Bay folio, Maine (with G. 0. Smith and E. S. Bastin). 

Manuscript geologic map of Frenchmans Bay quadrangle, Maine. 

Unpublished notes on the geology of Rhode Island. 

Geologic map of the granites of Maine: Bull. U.S. Geol. Survey No. 313, 1906 (with E. S. Bastin and G. 0. Smith). 

Buckley, E. R. 

Geologic map of Missouri: Rept. Missouri Bureau of Geol. and Mines for 1903--4. 

Sketch manuscript map showing corrections to map of Missouri, 1904 (1907). 

Buehler, H. A. 

Notes on details of geology of Missouri. 

Burchard, E. F. 

Lancaster-Mineral Point folio, Wisconsin-Iowa-Illinois (with U. S. Grant). 

Butler, B. S. 

Unpublished notes on certain Devonian areas in Utah. 

Manuscript geologic map of Frisco and adjacent region of western Utah. 

Butts, Charles. 

Rural Valley, Ebensburg, and Warren folios, Pennsylvania, and Birmingham folio, Alabama. 
CONTRIBUTORS. 35-

Cairn~, D. D. 

Data on the foothills of Rocky Mountains south of main line of Canadian Pacific Railway: Rumm. Rept. GeoL 

Survey Canada for 1905, pp. 62-67. 

Whitehorse and Tantalus regions, Yukon: Summ. Rept. Geol. Survey Canada for 1906, pp. 22-30; idem for 1907, 

pp. 10-15; idem for 1908, pp. 26-32. 

Geologic map of Moose Mountain district of southern Alberta: Geol. Survey Canada, 1907. 

Geologic map of lower Lake Laberge and vicinity, Yukon Territory, scale 1 mile to 1 inch: Geol. Survey Canada, 

1908. 

Geologic map of Conrad and Whitehorse districts, Yukon: Geol. Survey Canada, 1908. 

Calkins, F. C. 

Geologic map of part of northern ~Washington: Bull. U. S. Geol. Survey No. 235, 1904 (with G. 0. Smith). 

Geologic map of the Camr d'Alene district, Idaho: Prof. Paper U. S. Geol. Survey ~o. 62, 1908 (with F. L. 

Ransome). 

Geologic map of part of east-central Washington: Water-Supply Paper U. S. Geol. Survey No. 118, 1905. 

Geologic map of part of northern Idaho: Bull. U.S. Geol. Survey No. 384, 1909. 

Manuscript map of Philipsburg quadrangle, Montana. 

Snoqualmie folio, Washington (with G. 0. Smith). 

Calvert, W. R. 

Geologic map of the vicinity of Judith Mountains, Montana: Bull. U. S. Geol. Survey No. 390, 1909. 

Data on Lewistown and Livingston coal fields, Montana, used in compiling map of the coal-bearing Cretaceous 

and Tertiary. 

Campbell, H. D. 

Manuscript maps of Lexington and Natural Bridge quadrangles, Virginia. 

Campbell, M. R. 

Data on Black Mesa coal field, Arizona, used in compiling map of the coal-bearing Cretaceous and Tertiary. 

Geologic map of the coal-bearing Cretaceous and Tertiary of the central Western States, compiled by Bailey Willis 

and 11. R. Campbell. 

Estillville, Pocahontas, Tazewell, London, Richmond, Standingstone, Bristol, Huntington, Charleston, and 

Raleigh folios, southern Appalachians, and manuscript maps of adjacent areas; Danville folio, Illinois; and 

Masontown-Uniontown, Brownsville-Connellsville, and Latrobe folios, Pennsylvania. 

Geologic map of Deer Creek coal field, Arizona: Bull. U. S. Geol. Survey No. 225, 1904, pp. 24D-258. 

Camsell, Charles. 

Data on the region southwest of Fort Smith, Slave River, Northwest Territory: Summ. Rept. Geol. Survey Canada 

for 1902, pp. 151-169. 

!Data on the headwater region of Severn River, Northwest Territory: Summ. Rept. Geol. Survey Canada for 1904, 

pp. 143-152. 

Data on Peel and Wind rivers: Ann. Rept. Geol. Survey Canada for 1904, vol. 16, Rept. CC. 

Data on Peel River, in the Yukon and Mackenzie districts: Summ. Rept. Geol. Survey Canada for 1905, pp. 36-46. 

Data on Osoyoos and Similkameen mining divisions, British Columbia: Summ. Rept. Geol. Survey Canada for 

1907, pp. 24-31; idem for 1908, pp. 61-64. 

Geologic map of Similkameen district, British Columbia: Geol. Survey Canada, 1907. 

Chamberlin, T. C. 

Member of committee on pre-Cambrian nomenclature. 

Geologic map of Wisconsin: Wisconsin Geol. Survey, 1881. 

Milwaukee folio, Wisconsin (with W. C. Alden). 

Clapp, C. H. 

Data on southeastern part of Vancouver Island: Summ. Rept. Geol. Survey Canada for 1908, pp. 52-60. 

Clapp, F. G. 

Amity and Rogersville folios, Pennsylvania; Patoka folio, Indiana-Illinois (with M. L. Fuller). 

Geologic map of Florida: Ann. Rept. Geol. Survey Florida, 1909 (with G. C. Matson and Samuel Sanford). 

Clark, W. B. 

Geologic map of Maryland: Maryland Geol. Survey, vol. 6, 1906. 

Furnished geologic map of the Atlantic Coastal Plain north of North Carolina, from cooperative surveys with States. 

Trenton and Philadelphia folios, New Jersey and Pennsylvania (with Florence Bascom and others). 

Clarke, J. M. 

Corrections to geologic map of New York published in 1901. 

Geologic map of eastern part of Gaspe Peninsula, Quebec: Mem. New York State Mus. No.9, 1908. 

Ma.nuscript map of other parts of Gaspe Peninsula, Quebec. 

Collier, A. J. 

Data on Miles City coal field, Montana, used in compiling map of the coal-bearing Cretaceous and Tertiary. 

Geologi~ map of Arkansas coal field: Bull. U. S. Geol. Survey No. 326, 1907. 

Data on Yukon Valley, St. Lawrence Island, Cape Lisburne region, and Seward Peninsula, used in compiling 

manuscript map of Alaska. 
36 INDEX TO THE STRATIGRAPHY OF NORTH AMERlCA. 

Collins, W. H. 

Data on Montreal River district, Ontario: Summ. Rept. Geol. Survey Canada for 1908, pp. 11.5-120. 

Geologic map of northwestern Ontario traversed by the Transcontinental Railway between Lake Nipigon and 

Sturgeon Lake: Geol. Survey Canada, 1908. 

Geologic map of northwestern Ontario traversed by National Transcontinental Railway between Lake Nipigon 

and Clay Lake, Ontario: Geol. Survey Canada, 1909. · 

Geologic map of Gowganda mining division, district of Nipissing, Ontario: Geol. Survey Canada, 1909. 

Geologic map of the region north of Lake Superior between Pic and K ipigon riverR, Ontario: Geol. Survey Canada, 

1909. 

Cook, G. H. 

Geologic map of Kew Jersey: Geol. Survey New Jersey, 1890. 

Crandall, Roderic. 

Unpublished data on geology of Mount Hamilton region, California. 

·Crider, A. F. 

Data on the Tertiary and Cretaceous of l\lississippi and on the Tertiary of Arkansas, used in compilation of the 

map of the Atlantic and Gulf Coastal Plain. 

Geologic map of Mississippi: Bull. Mississippi State Geol. Survey No. 4, 1908. 

Crosby, W. 0. 

Maps of the Boston Basin, used in compiling map of New England: Occas. Papers Boston Soc. Kat. llist., 4th ser., 

vol. 1, pt. 1, 1893, pp. 1-177; pt. 2, 1894, pp. 179-288; pt. 3, 1900, 289-563. 

Cross, Whitman. 

Telluride, La Plata, Silverton, Rico, Needle Mountains, Ouray, and Engineer Mountain folios, southwestern 

Colorado, and ·manuscript maps of the adjacent Lake City and Durango quadrangles. 

Notes for correction of the Hayden map of Colorado. 

Geologic map of the Denver Basin, Colo.: Mon. U.S. Geol. Survey, vol. 27, 1896 (with S. F. Emmons and G. H. 

Eldridge). 

Pikes Peak and Anthracite-Crested Butte folios, central Colorado. 

Geologic map of Silver Cliff and Rosita Hills, Colorado: Seventeenth Ann. Rept. U. S. Geol. Survey, pt. 2, 1896, 

pp. 269-403. 

Cummins, W. F. 

Geologic map of Staked Plain and adjacent area, Texas: Third Ann. Rept. Geol. Survey Texas, 1891 (with E. T. 

Dumble). 

Dale, T. N. 

Manuscript maps of Housatonic, Taconic, and Mettawee quadrangles, Massachusetts, Vermont, and New York. 

Geologic map of Grey lock and Hoosac mountains, Mass.: ~fon. U. S. Geol. Survey, vol. 23, 1894 (with Raphael 

Pumpelly and J. E. Wolff). 

Geologic map of the slate belt of eastern New York and western Vermont: Nineteenth Ann. Rept. U. S. Geol. 

Survey, pt. 3, 1899, pp. 153-308. 

Dall, W. H. 

Data on Kodiak Island and Nunivak Island, used in compiling manuscript map of Alaska. 

Daly,R. A. 

Member (part of the time) of the committee on pre-Cambrian nomenclature. 

Data on the western part of the international boundary: Summ. Rept. Geol. Survey Canada for 1901, pp. 37-49; 

idem for 1902, pp. 136-147; idem for 1903, pp. 91-100; idem for 1904, pp. 91-100; Rept. Chief Astronomer Canada, 

Dept. Interior, for 1905, appendix 8, 1906, pp. 278-283; idem for 1906, appendix 5, 1907, pp. 131-135. Also 

manuscript geologic map of the region. 

Darton, N.H. 

Camp Clark and Scotts Bluff folios, Nebraska; Oelrichs, Newcastle, Edgemont, Sundance, Devils Tower, Belle 

Fourche, and Aladdin folios, Black Hills, South Dakota; Bald Mountain-Dayton and Cloud Peak-Fort McKinnev 

folios, Bighorn Mountains; and Laramie-Sherman .folio, Rocky Mountains of Wyoming. · 

Geologic maps of the Black Hills, South Dakota: Bighorn Mountains, \Yyoming; and Great Plains: Prof. Paper 

U. S. Geol. Survey Nos. 17, 32, 51, W, and 65; Twenty-first Ann. Rept. U. S. Geol. Survey, pt. 4, 1901, pp. 

497-599; Water-Supply Paper U.S. Geol. Survey No. 227, 1909. 

Fredericksburg, Nomini, Sta:.tnton, Franklin, Piedmont, Monterey, Washington, New York City, Passaic, Philadelphia, and Trenton folios, Appalachian region; manuscript maps of parts of Lewisburg, Dublin, Christiansburg, Roanoke, Hillsville, Huntsville, Hinton, and Harrisonburg quadrangles, Virginia. 

Reconnaissance map of northwestern 1'\ew ~Texico and northern Arizona: Bull. U. S. Geol. Survey 1'\o. 43fi, 1910. 

Geologic map of Owl Creek Mountains, \Yyoming: Senate Doc. 219, .S9th Cong., 1st sess., 1906. 

Geologic map of central Wyoming, \Yind River to Owl Creek: Bull. Geol. Soc. America, vol. 19, 1908, pp. 403·-''70. 

Manuscript map of Deming quadrangle, New Mexico. 

Geologic map of Laramie BaRin, Wyoming: Bull. 'G. S. Geol. Survey No. 364, 1909 (with C. E. Siebenthal). 

Notes on Cambrian and pre-Cambrian areas in San Bernardino County, Cal. 
CONTRIBUTORS. 37 

Davis, W.M. 

Geologic map of the Triassic area of Connecticut: Eighteenth Ann. Rept. U. H. Geol. Survey, pt. 2, 1898, pp. 

1-192. 

Dawson, G. M. 

Data concerning Tertiary lignite formation in the vicinity of the forty-ninth parallel: Geol. Rept. Prog. Brit. 

North America Boundary Comm. for 1873 (in part). 

Geologic sections and data on region between Lake of the Woods and the Rocky Mountains: Rept. Geol. 49th 

Par. Brit. North America Boundary Comm., 1875. 

Data on British Columbia: Rept. Prog. Geol. Survey Canada for 1875-7G, pp. 233-265; idem for 1876-77, pp. 

95-102. 

Geologic map of British Columbia between Fraser River and the Coast Range: Rept. Prog. Geol. Survey Canada 

for 1876-77, with report, pp. 17-94. 

Data on Leech River region, British Columbia: Rept. Prog. Geol. Su'rvey Canada for 1876-77, pp. 95-102. 

Geologic map and data on southern portion of interior of British Columbia: Rept. Prog. Geol. Survey Canada for 

1877-78, Rept. B. 

Data on Queen Charlotte Islands: Rept. Prog. Geol. Survey Canada for 1878-79, Rept. B. (with geologic map). 

Data on region from Souris River to one hundred and eighth meridian: Rept. Prog. Geol. Survey Canada for 

1879-80, Rept. A, appendix I. 

Data on northern part of British Columbia and Peace River country, from Port Simpson on Pacific coast to 

Edmonton on Saskatchewan: Rept. Prog. Geol. Survey Canada for 1879-80, Rept. B. 

Data on Bow and Belly rivers region, Alberta: Rept. Prog. Geol. Survey Canada for 1880-82, Rept. B; idem for 

1882-84, Rept. C (with geologic map). 

Geologic map of Rocky Mountains between latitudes 49° and 51° 30': Ann. Rept. Geol. Survey Canada for 1885, 

new ser., vol. 1, Rept. B. 

Geologic map of northern part of Vancouver Island and adjacent coasts: Ann. Rept. Geol. Survey Canada for 1886, 

vol. 2, Rept. B. 

Geologic map of northern portion of the Dominion of Canada east of the Rocky Mountains: Ann. Rept. Geol. 

Survey Canada for 1886, vol. 2, Rept. R. 

Data on southern interior of British Columbia: Summ. Rept. Geol. Survey Canada for 1887-88, pp. 60-66. 

Data on Yukon Territory and northern British Columbia: Ann. Rept. Geol. Survey Canada for 1887-88, vol. 3, 

pt. 1, Rept. B. 

Data on West Kootenay district, British Columbia: Ann. Rept. Geol. Survey Canada for 188~-89, vol. 4, Rept. B. 

Kamloops map s.\J.eet, British Columbia: Ann. Rept. Geol. Survey Canada for 1894, vol. 7, Rept. B. 

Notes on Yukon district and adjacent northern part of British Columbia, compiled from report of 1898. 

Geologic map of Dominion of Canada (western sheet), scale 50 miles to 1 inch: Geol. Survey Canada, edition of 

1901. 

Data on Nunivak Island, used in compiling manuscript map of Alaska. 

Denis, Theodore. 

Data on the country around Bruce mines, Ontario: Summ. Rept. Geol. Survey Canada for 1904, pp. 179-190. 

Diller, J. S. 

Geologic map of the Klamath Mountains, Oregon and northern California, compiled for this map. 

Geologic map of Crater Lake region, Oregon: Prof. Paper U. S. Geol. Survey No. 3, 1902. 

Geologic map of Taylorsville region, California: Bull. U. S. Geol. Survey, No. 353, 1908. 

Lassen Peak, Coos Bay, Roseburg, Port Orford, and Redding folios, Oregon and California, and manuscript maps 

of adjacent Riddles, Granite Pass, Red Bluff, and parts of Ashland and Shasta quadrangles. 

Notes on the geology of northwestern Oregon: Seventeenth Ann. Rept. U. S. Geol. Survey, pt. 1, 1896, pp. 447-520. 

Deussen, Alexander. 

Manuscript geologic map of the Tertiary of the Gulf coast of Texas west of Galveston. 

Dobbs, W. S. 

Data on the region south of Cape Tatnam, Northwest Territory: Summ. Rept. Geol. Survey Canada for 1905, 

pp. 69-73. 

Dowling, D. B. 

Data on vicinity of Red Lake and part of the basin of Berens River, Keewatin: Ann. Rept. Geol. Survey Canada 

for 1894, vol. 7, Rept. F. 

Geologic map of Lake Winnipeg and vicinity: Ann. Rept. Geol. Survey Canada for 1898, vol. 11, Rept. G (with 

J. B. Tyrrell). 

Data on Nipigon Lake district, Ontario: Summ. Rept. Geol. Survey Canada for 1898, pp. 94-99. 

Data on Saskatchewan district: Summ. Rept. Geol. Survey Canada for 1899, pp. 110-115. 

Geologic map of Athabasca, Saskatchewan, and Keewatin, including l\Ioose Lake and the route from Cumberland 

Lake to Churchill River and the upper parts of Burntwood and Grass rivers: Ann. Rept. Geol. Survey Canada 

for 1900, vol. 13, Rept. FF. 

Data on the west side of James Bay: Summ. Rept. Geol. Survey Canada for 1901, pp. 107-115. 
38 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Dowling, D. B.-Continued. 

Data on Ekwan River, Sutton Mill lakes, and west coast of James Bay: Ann. Rept. Geol. Survey Canada for 1901, 

vol. 14, Rept. F. 

Data on Rocky Mountains, Sheep Creek and Cascade troughs northward to Panther RiYer: Summ. Rept. Geol. 

Survey Canada for 1903, pp. 83-91. 

Geologic map of Costigan coal field: Ann. Rept. Geol. Survey Canada for 1904, vol. 16, Rept. A. 

Data on the Cascade and Costigan coal basins, Alberta: Summ. Rept. Geol. Survey Canada for 1904, pp. 105-121. 

Data on the northern extension of Elk River coal basin: Summ. Rept. Geol. Survey Canada for 1905, pp. 59-62. 

Data on the Rocky Mountains between Bow and Yellowhead passes: Summ. Rept. Geol. Survey Canada for 1906, 

pp. 66-73; idem for 1907, pp. 32-34; idem for 1908, pp. 77-86. 

Geologic map of Cascade coal basin, Alberta: Geol. Survey Canada, 1907. 

Geologic map of coal fields of Manitoba, Saskatchewan, Alberta, and eastern British Columbia: Geol. Survey 

Canada, 1909 (and later manuscript corrections). 

Data on and geologic map of country between Athabasca Lake and Churchill River: Ann. Rept. Geol. Survey 

Canada for 1895, vol. 8, Rept. D (with J. B. Tyrrell). 

Geologic map of Lake Winnipeg and vicinity: Ann. Rept. Geol. Survey Canada for 1898, vol. 11, Rept. G (with 

J. B. Tyrrell). 

Boundaries-of Eocene against Upper Cretaceous in M 12, N ll-12. 

Drake, N. F. 

Nampa folio, Idaho-Oregon, and Silver City folio, Idaho (witli Waldemar Lindgren). 

Dresser, J. A. 

Data on Shefford and Brome mountains, Quebec: Summ . .Rept. Geol. Survey Canada for 1901, pp. 183-187; Ann. 

Rept. for 1900, vol. 13, Rept. L; idem for 1904, vol. 16, pt. G. 

Geologic map of Brome Mountain, Brome County, Quebec: Ann. Rept. Geol. Survey Canada for 1904, vol. 16, 

Rept. G. 

Geologic map of eastern townships of Quebec: Geol. Survey Canada, Report on copper deposits, 1907. 

Data on Lake Megantic and vicinity, Compton County, Quebec: Geol. Survey Canada, 1908. 

Data on country along National Transcontinental Railway from St. Lawrence River to interprovincial boundary: 

Summ. Rept. Geol. Survey Canada for 1908, pp. 124-128. 

Geologic map of St. Bruno Mountain, Chambly County, Quebec: Mem. Geol. Survey Canada No.7, 1910. 

Dumble, E. T. 

Geologic map of Staked Plain and adjacent area, Texas: Third Ann. Rept. Geol. Survey Texas, 1891 (with W. F. 

Cummins). 

Geologic map of part of southwestern Texas: Trans. Am. Inst. Min. Eng., vol. 33, 1903, pp. 914-987. 

Notes on eastern New Mexico: Trans. Am. Inst. Min. Eng., vol. 31, 1902, pp. 696-715. 

Dutton, C. E. 

Atlas of High Plateaus of Utah: U. S. Geog. and Geol. Survey Rocky Mtn. Region, 1880. 

Geologic map of Grand Canyon district, Arizona: Mon. U. S. Geol. Survey, vol. 2, 1882. 

Geologic map of northwestern New Mexico: Sixth Ann. Rept. U. S. Geol. Survey, 1885, pp. 106-198. 

Eakin, H. M. 

Data on Yukon River-Norton Bay regions, used in compiling manuscript map of Alaska. 

Eldridge, G. H. 

Anthracite-Crested Butte folio, Colorado (with ·whitman Cross and S. F. Emmons). ::\fanuscript geologic maps 

of Santa Paula and Santa Susana quadrangles, California. 

Data on Susitna basin, used in compiling manuscript map of Alaska. 

Manuscript maps covering portions of Ventura, Los Angeles, and Orange counties, Cal. 

Geologic map of Santa Clara Valley, Puente Hills and Los Angeles oil districts, California: Bull. U. fl. Geol. Survey 

No. 309, 1907 (with Ralph Arnold). 

Geologic map of Denver Basin, Colo.: Mon. U. S. Geol. Survey, vol. 27, 1896 (with S. F. Emmom and Whitman 

Cross). 

Geologic map of northwestern Wyoming: Bull. U. S. Geol. Survey No. 119, 1894. 

Geologic map of the Uinta Basin, Utah and Colorado: Twenty-second Ann. Rept. U. S. Geol. Surn~y, pl. 1, l90J, 

p. 332. 

Geologic map of San Luis Obispo district, California: Twenty-second Ann. Rept. U. fl. Geol. Survey, pt .. J, 1901, 

p. 412. 

Ells, R. W. 

Boring operations at Newcastle Bridge, New Brunswick: Rep!. Prog. Geol. Survey Canada for 1872-73, pp. 231-

237; idem for 1874-75, pp. 90-96. 

Geologic map and data on Carleton County, ~ew Brunswick: Rept. Prog. Geol. Survey Canada for 1874-75, pp. 

97-104. 

Data on Albert, eastern Kings, and St. John counties, southern New Brunswick: Rept. Prog. Goo I. Survey Canada 

for 1877-78, Rept. D. 

Data on northern New Brunswick, embracing portions of Restigouche, Gloucester, and ~orthnmberland counties: Rept. Prog. Geol. Survey Canada for 1879-80, Rept. D. 
CONTRIBUTORS. 39 

Ells, R. W.-Continued. 

Geologic map of northern and eastern New Brunswick to the north side of the Bay of Chaleur: Rept. Prog. Geol. 

Survey Canada for 1880-1882, Rept. D. · 

Data on Ga.9pe Peninsula and Prince Edward Island: Rept. Prog. Geol. Survey Canada for 1880-1882, Rept. DD; 

idem for 1882-1884, Rept. E. 

Data and geologic map of eastern Albert and Westmoreland counties, New Brunswick, and portions of Cumberland 

and Colchester counties, Nova Scotia: Ann. Rept. Geol. Survey Canada for 1885, vol. 1, Rept. E. 

Geologic map of Compton, Stanstead, Beauce, Richmond, and Wolfe counties, Quebec: Ann. Rept. Geol. Survey 

Canada for 1886, vol. 2, Rept. J. 

Three Rivers sheet, northwestern sheet of the eastern townships map, Quebec: Ann. Rept. Geol. Survey Canada 

for 1898, val. 11, Rept. J. 

Geologic map of city of Ottawa and vicinity, Ontario and Quebec: Ann. Rept. Geol. Survey Canada for 1899, vol. 

12, Rept. G. 

Grenville sheet, geologic n1ap of Argenteuil, Ottawa, and Pontiac counties, Quebec, and Carleton, RuAsell, and 

Prescott counties, Ontario: Ann. Rept. Geol. Survey Canada for 1899, vol. 12, Rept. J. 

Data on Kingston district, Ontario: Summ. Rept. Geol. Survey Canada for 1901, pp. 170-183. 

Perth geologic sheet, Renfrew, Addington, Frontenac, Lanark, and Carleton counties, Ontario: Ann. Rept.. Geol. 

Survey Canada for 1901, vol. 14, Rept. J. 

Data on Gaspe, Quebec: Summ. Rept. Geol. Survey Canada for 1902, pp. 339-361. 

Data 'on Albert and Westmoreland counties, New Brunswick: Summ. Rept. Geol. Survey Canada for 1902, pp. 

363-369. 

Geologic map of Prince Edward Island: Summ. Rept. Geol. Survey Canada for 1902, p. 369. 

Data on Charlotte County, New Brunswick: Summ. Rept. Geol. Survey Canada for 1903, pp. 150-160; idem for 

1904, pp. 271-279. 

Data on southern New Brunswick: Summ. Rept. Geol. Survey Canada for 1906, pp. 131.-139; idem for 1907, pp. 

74-76. 

Geologic map of Pontiac, Carleton, and Renfrew counties (Pembroke sheet, No. 122): Rept. Geol. Survey Canada, 

1907. 

Data on Megantic, Beauce, Dorchester, Levis, Bellechasse, and Montmagny counties, Quebec: Ann. Rept. Geol. 

Survey Canada for 1887-88, vol. 3, pt. 2, Rept. K. 

Montreal sheet: Ann. Rept. Geol. Survey Canada for 1894, vol. 7, Rept. J. 

Geologic map of Graham Island, British Columbia: Ann. Rept. Geol. Survey Canada for 1904, vol. 16, Rept. B. 

Geologic map of coal basins of Quilchena Creek, Coldwater River, Coal Gully, and Guichon Creek, Nicola 

Valley, Yale district, British Columbia: Ann. Rept. Geol. Survey Canada for 1904, vol. 16, pt. A. 

Data on southern :!'lew Brunswick: Rept. Prog. Geol. Survey Canada for 1878-79, Rept. D (with L. W. Bailey 

and G. F. Matthew). 

Data on Albert and Westmorland• counties, New Brunswick: Rept. Prog. Geol. Survey Canada for 1876-77, pp. 

351-39.5, with geologic map of lower Carboniferous rocks of Albert and Westmorland counties (with L. W. Bailey). 

Emerson, B. K. 

Geologic map of Franklin, Hampshire, and Hampden counties, Mass.: Mon. U.S. Geol. Survey, vol. 29, 1898. 

Geologic map of part of Rhode Island from Woonsocket to Narragansett Bay: Bull. U. S. Geol. Survey No. 311, 

1907. 

Furnished manuscript geologic map of Massachlisetts. 

Holyoke and Hawley folios, Massachusetts-Connecticut, and manuscript maps of adjacent Housatonic, Ware, 

and Quinsigamond quadrangles. 

E=ons, S. F. 

Geologic map of Leadville, Colo., and vicinity: Mon. U. S. Geol. Survey, val. 12, 1886. 

Geologic map of the southern end of the Oquirrh Mountains, 1)tah: Sixteenth Ann. Rept. U. S. Geol. Survey, 

pt. 2, 1895, pp. 343-4-55 (with J. E. Spurr). 

Contributions to maps of the Fortieth Parallel Survey. 

Geologic map of Denver Basin, Colorado: .Mon. U.S. Geol. Survey, Yo!. 27, 189G (with Whitman Cross and G. H_ 

Eldridge). 

Anthracite-Crested Butte, Butte, Tenmile district, and Tintic folios, Rocky Mountains (with Whitman Cross and 

others). 

Emmons, W. H. 

Geologic map of part of northern Nevada: Bull. U. S. Geol. Survey Ko. 408, 1910. 

Fairbanks, H. W. 

San Luis folio, California. 

Faribault, E. R. 

Data on Nova Scotia: Summ. Repts. Geol. Survey Canada, 1894-1906. 

Geologic map of Nova Scotia (to illustrate report on the gold fields of Nova Scotia): Geol. Survey Canada, 1906. 

Data on Lunenburg County, Nova Scotia: Summ. Rept. Geol. Survey Canada for 1907, pp. 78-83; idem for 1908, 

pp. 150-158. 
40 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Faribault, E. R.-Continued. 

Data on Guysborough, Antigonish, Pictou, Colchester, and Halifax counties, Nova Scotia: Ann. Rept. Geol. 

·survey Canada for 1886, vol. 2, Rept. P (with Hugh Fletcher). 

Fenneman, N. M. , 

Geologic map of the Boulder district, Colorado: Bull. U. S. Geol. Survey No. 265, 1905. 

Data on Yampa coal field, Colorado, used in compiling map of the coal-bearing Cretaceous and Tertiary. 

Geologic map of Yampa coal field and vicinity, Colorado: Bull. U. S. Geol. Survey No. 297, 1906 (with H. S. 

Gale). 

Manuscript geologic map of St. Louis quadrangle, Missouri. 

Fernandez de Castro, Manuel. 

Geologic map of Cuba. Bol. Com. del Mapa Geol. Espana, vol. 8, 1881, pl. G (with Pedro Salterain y I,egarra). 

Fisher, C. A. 

Data on Great Falls coal field, Montana, used in compiling map of the coal-bearing Cretaceous and Tertiary. 

Nepesta folio, Colorado. 

Geologic map of the Roswell basin, southeastern New Mexico: Water-Supply Paper U.S. Geol. Survey Ko. 158, 

1906. 

Geologic map of Great Falls region, Montana: Water-Supply Paper U. S. Geol. Survey No. 221, 1909. 

Geologic map of the Bighorn Basin, ·wyoming: Prof. Paper U. S. Geol. Survey No. 53, 19(}7. 

Fletcher, Hugh. 

Data on Cape Breton, Nova Scotia: Rept. Frog. Geol. Survey Canada for 1875-76, pp. 369-418; idem for 1877-78, 

Rept. F; idem for 1882-1884, Rept. H. 

Data on Victoria, Cape Breton, and Richmond counties, Nova Scotia: Rept. Frog. Geol. Survey Canada for 1876-

77, pp. 402-456, with geologic map of part of Cape Breton. 

Geologic map of Springhill coal field, Cumberland County, Nova Scotia: Ann. Rept. Geol. Survey Canada for 

1902-3, vol. 15, Rept. A. 

Geologic map of the Nictaux and Torbrook iron district, Annapolis County, Nova Scotia: Ann. Rept. Geol. 

Survey Canada for 1904, vol. 16, Rept. A. 

Data on Pictou and Colchester counties, Nova Scotia: Ann. Rept. Geol. Survey Canada for 1890-91, vol. 5, ·pt. 2, 

Rept. P. 

Data on Nova Scotia: Summ. Repts. Geol. Survey Canada for 1894-1908. 

Geologic map of parts of Kings and Hants counties, Nova Scotia: Ann. Rept. Geol. Survey Canada for 1901, vol. 

14, Rept. A. 

Data on Richmond, Inverness, Guysborough, and Antigonish counties, Nova Scotia: Rept. Frog. Geol. Survey 

Canada for 1879-80, Rept. F. 

Data on Guysborough, Antigonish, Pictou, Colchester, and Halifax counties, Nova Scotia: Ann. Rept. Geol. Survey Canada for 1886, vol. 2, Rept. P (with E. R. Faribault.) 

Foerste; A. F. 

Geologic map of Narragansett Basin, Rhode Island: Mon. U. S. Geol. Survey, vol. 33, 1899 (with N. S. Shaler 

and J. B. Woodworth). 

Fuller, M. L. 

Manuscript map of Crowleys Ridge, Missouri and Arkansas. 

Ditney and Patoka folios, Indiana and Illinois; Gaines and Elkland-Tioga folios, Pennsylvania and New York. 

Gale, H. S. 

Geologic maps of part of northwestern Colorado and northeastern Utah: Bull. U. S. Geol. Survey No. 341, 1909,' 

pp. 283-315; Bull. No. 415, 1910. 

Geologic map of Raven Park and vicinity, western Colorado: Bull. U. S. Geol. Survey No. 350, 1908. 

Geologic maps of phosphate areas in southeastern Idaho, northeastern Utah, and adjacent parts of Wyoming: 

Bull. U. S. Geol. Survey No. 430, 1910, pp. 457-551 (with R. W. Richards). 

Geologic map of Yampa coal field and vicinity, Colorado: Bull. U. S. Geol. Survey No. 297, 1906 (with N. M. 

Fenneman). 

Data on Buffalo (Wyoming), Yampa, Grand Hogback, and White River (Colorado), and Vernal (Utah) coal fields, 

used in compiling map of the coal-bearing Cretaceous and Tertiary. 

Garde, Victor. 

Geologic map of southeastern Greenland: Meddelelser om Griinland, vol. 9, 1889, pp. 53-144 (with G. F. Holm). 

Gardner, Miss J. A. 

Data on the Tertiary of Virginia and North ·carolina, used in compiling map of Atlantic Coastal Plain. 

Gardner, J. H. 

Geologic map of coal field between Cuba and San Mateo, N.Mex.: Bull. U.S. Geol. Survey No. 381, 1910, pp. 

461-473. 

Data on San Juan coal region, New Mexico, used in compiling map of the coal-bearing Cretaceous and Tertiary. 

Geologic map of parts of the San Juan coal field, New Mexico: Bull. U. S. Geol. Survey No. 341, 1909, pp. 335-378. 

Geiger, H. R. 

Manuscript geologic maps of Romney, Winchester, Woodstock, Harrisonburg, and Luray quadrangles, Virginia. 

Revised by Arthur Keith. 
CONTRIBUTORS. 

George, R. D. 

Notes on the details of geology of Colorado. 

Gilbert, G. K. 

Contributed to the map of the Wheeler Survey. 

Pueblo folio, Colorado. 

Manuscript geologic map of Apishapa quadrangle, Colorado. 

Geologic map of the Henry Mountains, Utah: U. S. Geog. and Geol. Survey Rocky Mtn. Region, 1880. 

41 

Map of J,ake Bonneville Quaternary deposits of Utah and adjacent parts of Nevada and Idaho: Mon. U. S. Geol. 

Survey, vol. 1, 1885. 

Girty, G. H. 

Notes on distribution of marine Carboniferous in the United States, for this map. 

Glenn, L. C. 

Data on the Cretaceous of Tennessee and the Tertiary of Tennessee, Kentucky, and Illinois, used in compiling the 

map of the Atlantic Coastal Plain. 

Geologic map of parts of Tennessee, Kentucky, and Illinois: Water-Supply Paper U.S. Geol. Survey No. 164, 1906. 

Goldman, M. I. 

Data on Colorado Springs coal field, Colorado, used in compiling map of the coal-bearing Cretaceous and Tertiary. 

Geologic map of CGJlorado Springs coal field, Colorado: Bull. U. S. Geol. Survey No. 381, 1910, pp. 317-340. 

Go1dthwait, J. W. 

Geologic map of Toqueville district, Utah: Bull. Mus. Comp. Zool. Harvard Coli. No. 42, 1904 (with Ellsworth 

Huntington). 

Gorby, S. S. 

Geologic map of Indiana: Geol. and Nat. Hist. Survey Indiana, 1893. 

Gordon, C. H. 

Data on the Cretaceous of Texas and Oklahoma, used in compiling the map of the Atlantic and Gulf Coastal Plain. 

Geologic map of part of San Mateo and the Black, Caballos, and Cristobal ranges, New Mexico: Prof. Paper U. S. 

Geol. Survey No. 68, 1910, pp. 213-285. 

Gould, C. N. 

Geologic map of Oklahoma: Water-Supply Paper U. S. Geol. Survey No. 148, 1905. 

Geologic map of parts of northern Texas: Water-Supply Paper U. S. Geol. Survey No. 191, 1907. 

Grabau, A. W. 

Geologic map of Becraft Mountain, New York: Bull. New York State Mus. No. 69, 1903, pp. 1030-1079. 

Geologic map of Schoharie and Cobleskill valleys, New York: Bull. K ew York State Mus. No. 92, 1906. 

Graham, R. P. D. 

Data on the coast of British Columbia, from Kingcome Inlet to Dean Channel, including the adjacent iel.ands: 

Summ. Rept. Geol. Survey Canada for 1908, pp. 38-40. 

Grant, U.S. 

Lancaster-Mineral Point folio, Wisconsin-Iowa-Illinois (with E. F. Burchard). 

Data on Prince William Sound and eastern half of Kenai Peninsula, used in compiling manuscript map of Alaska. 

Gregory, H. E. 

Data on Black Mesa coal field, Arizona, used in compiling map of the coal-bearing Cretaceous and Tertiary. 

Geologic map of Connecticut: Connecticut Geol. and Nat. Hist. Survey, 1906 (with H. H. Robinson). 

Manuscript map of northeastern Arizona, 1910. 

Griswold, L. S. 

Geologic map of novaculite area, central Arkansas: Third Ann. Rept. Geol. Survey Arkansas, 1890 (with J. A. 

Branner). 

Gwillim, J. C. 

Geologic map of Atlin mining district, British Columbia: Ann. Rept. Geol. Survey Canada for 1899, vol. 12, 

Rept. B. 

Hague, Arnold. 

Geologic map of Yellowstone Park and adjacent part of Wyoming: Mon. U. S. Geol. Survey, vol. 32, 1904. 

Geologic map of the Eureka d'istrict, Nevada: }ion. U. S. Geol. Survey, vol. 20, 1892. 

Yellowstone National Park and Absaroka folios, Wyoming. 

Hall, C. M. 

Alexandria and De Smet folios, South Dakota: Casselton-Fargo folio, North Dakota-Minnesota. 

Hamlin, Homer. 

Manuscript geologic map of part of Monterey County, Cal. 

Ha=er, R. R. I. 

Geologic map of part of the west coast of Greenland: Meddelelser om Gronland, vol. 4, 1893, pp. 173-242 (with 

K. J. V. Steenstrup). 

Geologic map of part of northwestern Greenland: Meddelelser om Gronland, vol. 8, 1889, pp. 1-32. 

Harder, E. C. 

Geologic map of Iron Spring district, southwestern Utah: Bull. U.S. Geol. Survey No. 338, 1908 (with C. K. Leith). 

Unpublished notes on part of southeastern California. 
42 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Harris, G. D. 

Data on the Tertiary of Louisiana, used in compiling the map of the Gulf Coastal Plain. 

Geologic map of Louisiana: Geol. Survey Louisiana, pt. 4, 1902. 

Hartley, Edward. 

Data on Pictou County, Nova Scotia: Rept. Prog. Geol. Survey Canada for 1866-1869, pp. 55-107, 365-442. 

Geologic map of Pictou coal field (with W. E. Logan). 

Haworth, Erasmus. 

Geologic map of Kansas: Kansas Univ. Geol. Survey, vol. 9, 1908. 

Haycock, Ernest. 

Data on west coast of Vancouver Island: Summ. Rept. Geol. Survey Canada for 1902, pp. 76-92. 

Data on Ottawa County, Quebec: Summ. Rept. Geol. Survey Canada for 1904, pp. :!32-239. 

Data on Labelle and Wright counties, Quebec: Summ. Rept. Geol. Survey Canada for 1905, pp. 105-112. 

Hayden, F. V. 

Geologic maps of Colorado and parts of Idaho, Montana, Utah, Wyoming, Arizona, New Mexico, South Dakota, 

and Nebraska: Repts. U.S. Geol. and Geog. Survey Terr., 1867-1882. 

Hayes, C. W. 

Member (part of the time) of committee on pre-Cambrian nomenclature. 

Ringgold, Kingston, Chattanooga, Sewanee, Stevenson, Cleveland, Pikeville, McMinnville, Gadsden, Rome, and 

Columbia folios; southern Appalachians. 

Manuscript maps of Anniston, Tallapoosa, Marietta, Dalton, Cartersville, Fort Payne, and Murphy quadrangles, 

southern Appalachians. 

Unpublished notes on the geology of eastern Mexico. 

Geologic reconnaissance of Cuba: Rept. Military Governor Cuba for 1901 (with T. W. Vaughan and A. C. Sp<Jncer). 

Data on geology of region adjacent to the Nicaragua Canal route: Bull. Geol. Soc. America, vol. 10, 1899, pp. 

285-348; Science, new ser., vol. 10, '1899, p. 97. 

Heikes, V. C. 

Geologic map of Fort Hall mining district, southeastern Idaho: Bull. U.S. Geol. Survey No. 340, 1908 (with F. B. 

Weeks). 

Herrick, C. L. 

Geologic maps of parts of Bernalillo and Valencia counties, N.Mex.: Am. Geologist, vol. 25, 1900, pp. 331-346. 

Hershey, 0. H. 

Manuscript geologic map of part of southern California north of Los Angeles and San Bernardino. 

Hess, F. L. 

Notes on the Randsburg district, California. 

M-anuscript geologic map of the Randsburg quadrangle, southern California. 

Hettner, Alfred. 

Geologic map of centr:l Colombia, Kordillere von Bogota: Petermanns Mitt., Erganzungsband 22, Heft 104, 1892. 

Higgins, D. F. 

Data on Prince William Sound and eastern half of Kenai Peninsula, used in compiling manuscript map of Alaska. 

Hill, B. F. 

Geologic map of portion of southwestern Texas, from Lone Mountains to Chisos district: Repts. Univ. Texas Min. 

Survey, 1904 (with J. A. Udden). 

Hill, J. M. 

Manuscript geologic map of Patagonia and Nogales quadrangles, southern Arizona (with F. C. Schrader). 

Hill, R. T. 

Manuscript map of Chihuahua, Sonora, and part of Coahuila, Mexico, used in part. 

Manuscript map of southern Arizona, southern California, southern and eastern New Mexico, and Texas, used 

in part. 

Map of eastern Texas: Twenty-first Ann. Rept. U. S. Geol. Survey, pt. 7, 1901. 

Austin and Nueces folios, Texas. 

Notes on the geology of the \Vest Indies and Central America, used in compiling map of these areas: Cuba and 

Porto Rico, 1898; Nat. Geog. ::O.fag., vol. 9, 1898, pp. 193-242; vol. 10, 1899, pp. 93-ll2; Bull. Mus. Comp. Zool. 

Harvard Coll., vol. 16, 1895, pp. 241-288. 

Hills, R. C. 

Walsenburg, Spanish Peaks, and Elmoro folios, southern Colorado. 

Hitchcock, C. H. 

Geologic map of Vermont: Final Rept. Vermont Geol. Survey, vol. 2, 1861; used by G. 0. Smith and E. S. Bastin 

in compiling ~ew England map. 

Hoeing, J. B. 

Geologic map of Kentucky, compiled for Kentucky Geol. Survey, 1907. 

Holm, G. F. 

Geologic map of part of southern Greenland: Meddelelser om Gronland, vol. 2, 1881, pp. 27-41 (with K. J. V. 

Steenstrup). 

Geologic map of southeastern Greenland: Meddelelser om Gronland, vol. 9, 1889, pp. 53-144 (with Victor Garde). 
CONTRIBUTORS. 43 

Howe, Ernest. 

Compiled geology of Panama, South America, and parts of the West Indies for the map of North America published by the International Geological Congress, 1906; in part incorporated in present map. 

Data on the Canal Zone: Rept. Isthmian Canal Comm. for 1907, pp. 108-138. 

Silverton and Needle Mountains folios, Colorado. 

Howley, J. P. 

Manuscript geologic map of Avalon Peninsula, Newfoundland, furnished by Geological Survey of Canada for 

geologic map of North America published for the International Geological Congress, Mexico, 1906. 

Huntington, Ellsworth. 

Geologic map of Toqueville district, Utah: Bull. Mus. Comp. Zool. Harvard Coll., 1904 (with J. IV. Goldthwait). 

Iddings, J.P. 

Livingston folio, 21iiontana (with IV. H. \Veed): Yellowstone National Park folio, Wyoming (with Arnold Hague 

and W. H. \Veed). 

Ingall, E. D. 

Data on the Bruce mines district, Algoma, Ontario: Summ. Rept. Geol. Survey Canada for 1902, pp. 244-254; 

idem for 1904, pp. 179-190. 

Ireland, William. 

Geologic map of California: California State !\lin. Bur., 1891, used in part. 

Jaggar, T. A., jr. 

Bradshaw Mountains folio, Arizona (with Charles Palache). 

Geologic map of the northern Black Hills, South Dakota: Prof. Paper U. S. Geol. Survey No. 26, 1904. 

Jessen, A. 

Geologic map of part of the southwestern coast of Greenland: Meddelelser om Gronland, vol. 16, 1896, pp. 123-170. 

Johnson, H. R. 

Geologic map of McKittrick-Sunset oil region, California: Bull. U. S. Geol. Survey No. 406, 1910 (with Ralph 

Arnold). 

Manuscript geologic map of San Joaquin Valley, California. 

Johnston, J. F. E. 

Data on the Abitibi Lake district, Ontario: Summ. Rept. Geol. Survey Canada for 1901, pp. 128-141. 

Data on Ottawa County, Quebec: Summ. Rept. Geol. Survey Canada for 1904, pp. 239-250. 

Johnston, R. A. A. 

Data on Aspen Grove and Aberdeen camp, British Columbia: Summ. Rept. Geol. Survey Canada for 1904, pp. 

74-80. 

Data along route of Transcontinental Railway in New Brunswick: Summ. Rept. Geol. Survey Canada for 1906, 

pp. 127-130. 

Johnston, W. A. 

Data on the Peterborough, Prince Edward, and Simcoe sheets, Ontario: Summ. Rept. Geol. Survey Canada for 

1905, pp. 92-94; idem for 1906, pp. 124-126; idem for 1907, pp. 56-58; idem' for 1908, pp. 97-102. 

Karsten, Hermann. 

Geologic map of part of Colombia, South America: Geologie de l'ancienne Colombie bolivarienne, Venezuela, 

Nouvelle-Grenade et Ecuador, Berlin, 1886, p. 62. 

Katz, F. J. 

Data on Iliamna and Lake Clark region, used in compiling manuscript map of Alaska. 

Kay, F. H. 

Manuscript geologic map of Llano and Burnet quadrangles, Texas (with A. C. Spencer and Sidney Paige). 

Keele, Joseph. 

Geologic map of upper Stewart River: Ann. Rept. Geol. Survey Canada for 1904, vol. 16, Rept. C. 

Data on Duncan Creek mining district: Summ. Rept. Geol. Survey Canada for 1904, pp. 18-42. 

Data on Stewart River: Summ. Rept. Geol. Survey Canada for 1905, pp. 32-36. 

Data on Pelly, Ross, and Gravel rivers, Yukon and Northwest Territory: Summ. Rept. Geol. Survey Canada for 

1908, pp. 33-37. 

Keith, Arthur. 

Harpers Ferry, Knoxville, Loudon, Morristown, Briceville, Wartburg, Washington, Maynardsville, Cranberry, 

Asheville, Greenville, Mount Mitchell, Nantahala, Roan Mountain, and Pisgah folios, Appalachian region, and 

manuscript maps of adjacent areas. 

Compiled and adjusted data of his own and others for parts of New England. 

Manuscript geologic maps of Frederick, Mount Vernon, Abingdon, Mount Guyot, Murphy, Saluda, Morganton, 

Cowee, Kings Mountain, and Gaffney quadrangles, central and southern Appalachians. 

Compiled and furnished data for map of pre-Cambrian and Paleozoic Appalachian Mountain and Piedmont Plateau 

region of Georgia, South Carolina, North Carolina, Tennessee, and Virginia, for this map. 

Geologic map of Bingham mining district, Utah: Prof. Paper 1I. S. Geol. Survey No. 38, 1905 (with J. M. Boutwell). 

Geologic map of Catoctin belt, Maryland and Virginia: Fourteenth Ann. Rept. U. S. Geol. Survey, pt. 2, 1893, 

pp. 285-395. 
44 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Kemp, J. F. 

Geologic map of Elizabethtown and Port Henry quadrangles, New York: Bull. Univ. New York No. 138, 1910 

(with Rudolph Ruedemann). 

Keyes, C. R. 

Geologic map of central New Mexico: Water-Supply Paper U. S. Geol. Survey No. 123, 1905, modified by data 

from W. T. Lee. 

Geologic map of Missouri: Missouri Geol. Survey, vol. 14, 1S94. 

Kindle, E. M. 

Data on Cape Lisburne region and Porcupine River, used in compiling manuscript map of Alaska. 

Watkins Glen-Catatonk folio, New York (with H. S. ·williams and R. S. Tarr). 

King, Clarence. 

Geologic maps of parts of Utah, Colorado, Wyoming, and Nevada: Repts. U. S. Geol. Expl. 40th Par., 1871-1878. 

Knopf, Adolph. 

Data on southeastern Alaska, upper Tanana and \Vhite River basins, and Matanuska Valley, used in compiling 

manuscript map of Alaska. 

Kornerup, A. 

Geologic map of part of southwestern coast of Greenland: Meddelelser om Gronland, vol. 1, 1879, pp. 77-140; 

vol. 2, 1881, pp. 49-194. 

Kiimmel, H. B. 

Passaic, Franklin Furnace, Trenton, Philadelphia, and Raritan folios, New Jersey and Pennsylvania. 

Corrections to geologic map of New Jersey of 1890. 

Lafla=e, J. C. K. 

Data on Saguenay region, Quebec: Rept. Prog. Geol./Survey Canada for 18S2-1884, Rept. D. 

La Forge, Laurence. 

Manuscript geologic map of Ellijay quadrangle, Georgia (with IV. C. Phalen). 

Lane, A. C. 

Geologic map of Michigan: Geol. Survey Michigan, 1905. 

Corrections to map of Michigan, 1905, by later correspondence. 

Lawson, A. C. 

Geologic map of San Francisco Peninsula, California: Fifteenth Ann. Rept. U.S. Geol. Survey, 1895, pp. 399-476. 

Furnished manuscript geologic map of California, north of San Francisco Bay, used in part. 

Manuscript geologic maps of Tamalpais, San Francisco, Concord, San :Mateo, and Haywards quadrangles, 

California. 

Geologic map of Lake of the Woods region, Ontario and Manitoba: Ann. Rept. Geol. Survey Canada for 1885, 

vol. 1, Rept. CC. 

Geologic map of the Rainy Lake region, Ontario: Ann. Rept. Geol. Survey Canada for 1887-S8, vol. 3, pt. 1, 

Rept. F. 

Leach, W. W. 

Data on CrowsNest coal field, British Columbia: Summ. Rept. Geol. Survey Canada fer. 1901, pp. 67-79. 

Geologic map of Blairmore-Frank coal fields, southern Alberta: Summ. Rept. Geol. Survey Canada for 1902, 

p. 169; Ann. Rept. Geol. Survey Canada for 1902-3, vol. 15, Rept. A. 

Geologic map of Telkwa Valley, British Columbia: Geol. Survey Canada, 1907. 

Data on Bulkley Valley and vicinity, British Columbia: Summ. Rept. Geol. Survey Canada for 1907, pp. 19-23; 

idem for 1908, pp. 41--45. 

Lee, W. T. 

Geologic niap of part of western Arizona: Bull. U.S. Geol. Survey No. 352, 1908. 

Manuscript map of central New Mexico, from El Paso, Tex., to Santa Fe, N.Mex. 

Data on coal fields of Grand Mesa and Crested Butte, Colorado, and Raton, New ·Mexico, used in compiling map 

of the coal-bearing Cretaceous and Tertiary. 

Geologic map of part of Salt River Valley, Arizona: Water-Supply Paper U. S. Geol. Survey No. 136, 1905. 

Leith, C. K. 

Geologic map of Lake Superior region: Mon. U. S. Geol. Survey, vol. 52, 1911 (with C. R. Van Ilise). 

Geologic map of the Iron Springs district, southwestern Utah: Bull. U.S. Geol. Survey No. 338, 1908 (with E. C. 

Harder). 

Unpublished notes on the prc-Camhrian in Canada. 

Leonard, A. G. 

Geologic map of North Dakota: Fourth Rept. North Dakota Gcol. Survey, 1906. 

Bismarck folio, North Dakota. 

LeRoy, 0. E. 

Map of and data on Nanaimo and New Westminster districts, British Columbia: Geol. Survey Canada, 1908. 

Data on Phoenix camp and Slocan district, British Columbia: Summ. Rept. Geol. Survey Canada for 1908, 

pp. 65-68. 

Geologic map of Island of ~fontreal and vicinity: Ann. Rept. Geol. Survey Canada for 1901, vol. 14, Rept. 0 (with. 

F. D. Adams). 

.. 
CONTRIBUTORS. 45 

Lesley, J.P. 

Geologic map of Pennsylvania, compiled by A. D. \Y. Smith, under direction of J.P. Lesley: Summ. Rept. Second 

Geol. Survey Pennsylvania, 1893. 

Leverett, Frank. 

Ann Arbor folio, Michigan (with I. C. Russell). 

Lewis, J. V. 

Geologic map of western North Carolina based on data furnished by Arthur Keith: Korth Carolina Geol. Survey, 

vol. 1, 1905 (with J. H. Pratt). 

Lindgren, Waldemar. 

Geologic map of Idaho Basin and Boise Ridge, Idaho: Eighteenth Ann. Rept. 1~. S. Geol. Survey, pt. :i, 1898, 

pp. 625-736. 

Geologic map of Silver City, De Lamar, and other mining districts in Idaho: Twentieth Ann. Rept. U.S. Geol. 

Survey, pt. 3, 1900, pp. 65-256. 

Placerville, Sacramento, Marysville, Smartsville, Nevada City, Pyramid Peak, Truckee, and Colfax folios, Sierra 

Nevada, California and Nevada; and manuscript maps of adjacent Sierraville, Carson, and Markleeville quadrangles; Boise, Nampa, and Silver City folios, southern Idaho; Clifton folio, southern Arizona. 

Geologic map of part of Bitterroot Range and Clearwater Mountains, Montana and Idaho: Prof. Paper U. S. Geol. 

Survey No. 27, 1904. 

Geologic map of part of eastern Oregon: Twenty-second Ann. Rept. U. S. Geol. Survey, pt. 2, 1901, pp. 551-776. 

Geologic map of the lower Snake River valley, Idaho: Eighteenth Ann. Rept. U. S. Geol. Survey, pt. 3, 1898, 

pp. 617-735. 

Lines, E. F. 

Foxburg-Clarion folio, Pennsylvania (with E. W. Shaw and M. J. Munn). 

Logan, W. E. 

Data on Ottawa River region: Rept. Prog. Geol. Survey Canada for 1845-46, pp. 5-98. 

Data on Lake Superior region, Ontario: Rept. Prog. Geol. Survey Canada for 1846-47,.pp. 5-46. 

Data on the country on the south side of St. Lawrence, from Montreal and Lake Champlain to River Chaudiere: 

Rept. Prog. Geol. Survey Canada for 1847-48, pp. 5-92. 

Data on region about Bay St. Paul and Murray Bay, and eastern townships, Quebec, from Chaudiere River to 

Temiscouata Portage Road: Rept. Prog. Geol. Survey Canada for 1849-50, pp. 5-72. 

Data on Chaudiere River region, Quebec: Rept. Prog. Geol. Survey Canada for 1850-51, pp. 5-11. 

Geologic map of Pictou coal field: Rept. Prog. Geol. Survey Canada for 1866-1869 (with Edward Hartley). 

Geologic map and data on Argenteuil and Two Mountains counties (Grenville district), Quebec: Rept. Prog. Geol. 

Survey Canada for 1853-1856, pp. 5-57. 

Data on River Rouge district: Rept. Prog. Geol. Survey Canada for 1858, pp. 5-66. 

Geologic map of Canada, scale 125 miles to 1 inch: Geol. Survey Canada, 1864. 

Notes on Ontario and Quebec: Prelim. Rept. Geol. Survey Canada for 1842; Rept. Prog. for 1843. 

Notes on the Joggins, Nova Scotia: Rept. Prog. Geol. Survey Canada for 1843. 

Data on Chat and Cascapedia rivers, Gaspe, and part of Chaleur Bay: Rept. Prog. Geol. Survey Canada for 1844, 

pp. 5-66. 

Data on counties of Deauharnois and Lake of Two Mountains and Chaudiere district, Quebec: Rept. Prog. Geol. 

Survey Canada for 1851-52, pp. 5-56. 1 

Data on region along north shore of St. Lawrence, between Montreal and Cape Tourmente: Rept. Prog. Geol. 

Survey Canada for 1852-53, pp. 5-74. 

Geologic map of Pictou coal field, Nova Scotia: Rept. Prog. Geol. Survey Canada for 1866-69. 

Louderback, G. D. 

Data for manuscript geologic map of Coast Ranges of California, compiled by Robert Anderson. 

Low,A.P. 

Member (part of the time) of committee on pre-Cambrian nomenclature. 

Geologic map of the Arctic Archipelago and northwestern Greenland, based on cruise of the Neptune: Geol. Survey 

Canada, 1906. 

Data on Gaspe Peninsula: Rept. Prog. Geol. Survey Canada for 1882-1884, Rept. F. 

Data on Mistassini region, Quebec: Ann. Rept. Geol. Survey Canada for 1885, vol. 1, Rept. D. 

Data on country between Lake Winnipeg and Hudson Bay: Ann. Rept. Geol. Survey Canada for 1886, vol. 2, 

Rept. F. 

Data on James Bay and country east of Hudson Bay, drained by the Big, Great Whale, and Clearwater rivers: 

Ann. Rept. Geol. Survey Canada for 1887-88, vol. 3, pt. 1, Rept. J. 

Data on Portneuf, Quebec, and Montmorency counties, Quebec: Ann. Rept. Geol. Survey Canada for 1890-91, 

vol. 5, Rept. L. 

Data on and geologic map of Labrador Peninsula along Eastmain, Koksoak, Hamilton, Manikuagan, and other 

rivers: Ann. Rept. Geol. Survey Canada for 1895, vol. 8, Rept. L. 

Data on Labrador Peninsula, Richmond Gulf to Ungava Bay: Ann. Rept. Geol. Survey Canada for 1896, vol. 9, 

Rept. L. 
46 INDEX TO 'l'HE STRATIGRAPHY OF NORTH AMERICA. 

Low, A. F.-Continued. 

Geologic map of south shore of Hudson Strait and of Ungava Bay: Ann. Rept. Geol. Survey Canada for 1898, 

vol. 11, Rept. L. 

Geologic map of east coast of Hudson Bay from Cape Wolstenholme to the south end of James Bay: Ann. Rept. 

Geol. Survey Canada for 1900, vol. 13, Rept. D. 

Data on Nastapoka Islands, Hudson Bay: Ann. Rept. Geol. Survey Canada for 1900, vol. 13, Rept. DD. 

Geologic map of Chibougamau region, Quebec: Geol. Survey Canada, 1906. 

Geologic map of the northeastern part of the Dominion of Canada: Cruise of the Neptune, Ottawa, 1906. 

Lupton, C. T. 

Data on the Bull Mountains (Montana) and Powder River (Wyoming) coal fields, used in compiling map of the 

coal-bearing Cretaceous and Tertiary. 

McCallie, S. W. 

Geologic map of Georgia: Bull. Geol. Survey Georgia No. 15, 1908. 

McConnell, R. G. 

Geologic map of Cypress Hills,. Wood Mountain, and adjacent country, Saskatchewan: Ann. Rept. Geol. Survey 

Canada for 1885, vol. 1, Rept. C. 

Data on and geologic section of Rocky Mountains near fifty-first parallel: Ann. Rept. Geol. Survey Canada for 

1886, vol. 2, Rept. D. 

Data on Yukon and Mackenzie basins: Ann. Rept. Geol. Survey Canada for 1888-89, vol. 4, Rept. D. 

Data on northern Alberta, comprising the country between Peace River and Athabasca River, north of Lesser 

Slave Lake: Ann. Rept. Geol. Survey Canada for 1890-91, vol. 5, Rept. D. 

Geologic map of .Finlay and Omenica rivers region, British Columbia: Ann. Rept. Geol. Survey Canada for 18Q4, 

vol. 7, Rept. C. 

Data on West Kootenay district, British Columbia: Summ. Rept. Geol. Survey Canada for 1895, pp. 23-37; idem 

for 1896, pp. 19-31; idem for 1897, pp. 27-34. 

Data on Yukon and adjacent parts of British Columbia: Summ. Rept. Geol. Survey Canada for 1898, pp. 46-55. 

West Kootenay sheet, British Columbia: Ann. Rept. Geol. Survey Canada for 1901, vol. 14 (portfolio) (with R. W. 

Brock). 

Geologic map of Klondike mining region: Ann. Rept. Geol. Survey Canada for 1901, vol. 14, Rept. B. 

Data on Macmillan River, Yukon: Summ. Rept. Geol. Survey Canada for 1902, pp. 22-38. 

Geologic map of Kluane mining district, Yukon Territory: Ann. Rept. Geol. Survey Canada for 1904, vol. 16, 

Rept. A. • 

Data on the headwaters of \Vhite River: Summ. Rept. Geol. Survey Canada for 1905, pp. 19-32. 

Data on Windy Arm, Tagish Lake, Yukon: Rept. Geol. Survey Canada, 1905. 

Data on Texada Island, British Columbia: Summ. Rept. Geol. Survey Canada for 1908, pp. 46-50. 

Geologic map of Whitehorse region, Yukon Territory: Rept. Geol. Survey Canada, 1909. 

McEvoy, James. 

Geologic map of Yellowhead Pass route from Edmonton to Tete-Jaune Cache, comprising portions of Alberta and 

British Columbia: Ann. Rept. Geol. Survey Canada for 1898, vol. 11, Rept. D. 

Data on Alberta: Summ. Rept. Geol. Survey Canada for 1898, pp. 71-86. 

Geologic map of East Kootenay district, British Columbia: Ann. Rept. Geol. Survey Canada for 1899, vol. 12. 

Macfarlane, Thomas. 

Data on county of Hastings, Ontario: Rept. Prog. Geol. Survey Canada for 1863-1866, pp. 91-113. 

Data on Lake Superior region, Ontario: Rept. Prog. Geol. Survey Canada for 1863-1866, pp. 115-164. 

Mcinnes, William. 

Data on Nipigon Lake district, Ontario: Summ. Rept. Geol. Survey Canada for 1894, pp. 48-51. 

Geologic map of Seine River and Lake Shebandowan map sheets, comprising portions of the Rainy River and 

Thunder Bay districts, Ontario: Ann. Rept. Geol. Survey Canada for 1897, vol. 10, Rept. H. 

Data on district east of Manitou, Ontario: Summ. Rept. Geol. Survey Canada for 1898, pp. 87-94. 

Data on Rainy River district, Ontario: Summ. Rept. Geol. Survey Canada for 1899, pp. 115-122. 

Data on the region southeast of Lac Seul, Ontario: Summ. Rept. Geol. Survey Canada for 1901, pp. 87-93. 

Data on the region northwest of Lake Nipigon, Ontario: Summ. Rept. Geol. Survey Canada for 1902, pp. 208-213. 

Data on Winisk River, Keewatin district: Summ. Rept. Geol. Survey Canada for 1902, pp. 100-108. 

Data on Hudson Bay Railway route, Northwest Territory: Summ. Rept. Geol. Survey Canada for 1906, pp. 87-98. 

Data on the Pasquia Hills and lower Carrot River region, Saskatchewan: Summ. Rept. Geol. Survey Canada for 

1907, pp. 41-47. 

Data on Churchill River and South Indian Lake, Northwest Territory: Summ. Rept. Geol. Survey Canada for 

1908, pp. 87-92. 

Geologic map of part of Northwest Territory drained by Winisk and upper Attawapiskat rivers: Rept. Geol. Survey 

Canada, 1910. 

Boundaries of Paleozoic against pre-Cambrian, and of Cretaceous against Paleozoic and pre-Cambrian in N 13-14. 

Geologic map of Victoria, Northumberland, and Restigouche counties, New Brunswick: Ann. Rept. Geol. Survey 

Canada for 1886, vol. 2, Rept. N (with L. W. Bailey). 
CONTRIBUTORS. 47 

Mcinnes, William-Continued. 

Data on northern New Brunswick and adjacent areas in Quebec, and in Maine: Ann. Rept. Geol. Survey Canada 

for 1887-88, vol. 3, Rept. M (with L. W. Bailey). 

McOuat, Walter. 

Data on country between Lake St. John and Lake Mistassini, Quebec: Rept. Prog. Geol. Survey Canada for 1871-72, 

pp. 115-119. 

Data on country between Lakes Timiskaming and Abitibi, Quebec: Rept. Prog. Geol. Survey Canada for 1872-73, 

pp. 112-135. 

Data on Cumberland County, Nova Scotia: Rept. Prog. Geol. Survey Canada for 1873-74, pp. 161-170. 

Macoun, John. 

Data on lower Peace and Athabasca rivers: Rept. Prog. for Geol. Survey Canada 1875-76, pp. 87-95. 

Maddren, A. G. 

Data .on Controller Bay region, Chitina Valley, Porcupine River, Chandalar and upper Koyukuk and Innuko 

region, used in compiling manuscript map of Alaska. 

Malloch, G. S. 

Data on the Cascades, Palliser, and Costigan coal basin, Alberta: Summ. Rept. Geol. Survey Canada for 1907, 

pp. 35-40. 

Data on Bighorn coal basin, Alberta: Summ. Rept. Geol. Survey Canada for 1908, pp. 70-76. 

Martin, G. C. 

Data on Controller Bay region, Kachemak Bay region, Alaska Peninsula, Iliamna and Lake Clark region, and 

Matanuska Valley, used in compiling manuscript map of Alaska. 

Accident-Grantsville folio, Maryland-Pennsylvania-West Virginia. 

Matson, G. C. 

Data on the Tertiary of Flarida, Alabama, and Mississippi, used in compiling map of Atlantic and Gulf Coastal 

Plain. 

Geologic map of Florida; Second Ann. Rept. Florida State Geol. Survey, 1909 (with F. G. Clapp and Samuel 

Sanford). 

Matthews, E. B. 

Geologic map of the crystalline rocks of Maryland and adjacent part of Pennsylvania: Am. Jour. Sci., 4th ser., 

vol. 17, 1904, pp. 141-159. 

Matthew, G. F. 

Data on Charlotte County, New Brunswick: Rept. Prog. Geol. Survey Canada for 1876-77, pp. 321-350. 

Data on southern New Brunswick: Rept. Prog. Geol. Survey Canada for 1877-78, Repts. E and EE. 

Data on Cape Breton Island, Nova Scotia: Rept. Geol. Survey Canada, 1903. 

Data on Queens, Sunbury, and York counties, New Brunswick: Rept. Prog. Geol. Survey Canada for 1872-73, pp. 

180-230 (with L. W. Bailey). 

Data on New Brunswick: Rept. Prog. Geol. Survey Canada for 1874-75, pp. 84-89 (with L. W. Bailey). 

Data on southern New Brunswick: Rept. Prog. Geol. Survey Canada for 1870-71, pp. 13-240; idem for 1875-76, 

pp. 348-368 (with L. W. Bailey). 

Data on southern New Brunswick: Rept. Prog. Geol. Survey Canada for 1878-79, Rept. D (with L. W. Bailey 

and R. W. Ells). 

Meinzer, 0. E. 

Manuscript geologic map of Estancia Valley and vicinity, New Mexico. 

Manuscript geologic map of the pre-Quaternary rocks of southwestern Minnesota. 

Mendenhall, W. C. 

Manuscript geologic map of San Bernardino Valley in San Bernardino County and Corona quadrangle, California. 

Data on Chitina Valley, upper Copper River region, Chandalar and upper Koyukuk, main Koyukuk Valley, and 

Kobuk Valley, used in compiling manuscript map of Alaska. 

Merriam, J. C. 

Notes on the geology of Berkeley Hills region, California. 

Notes on the geology of John Day Basin, Washington. 

Merrill, F. J. H. 

Geologic map of New York: Rept. New York State Geologist, 1901. 

New York City folio. 

Merritt, W. M. 

Geologic map of Ontario. 

Miller, B. L. 

St. Marys folio, Maryland-Virginia; Patuxent folio, Maryland-District of Columbia (with G. B. Shattuck); and 

Dover folio, Delaware-Maryland-New Jersey. 

Data on and manuscript maps of the Cretaceous of Maryland, New Jersey, Pennsylvania, Virginia, and North 

Carolina, used in compiling map of Atlantic Coastal Plain. 

:Miller, W. G. 

Member (part of the time) of committee on pre-Cambrian nomenclature. 
48 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Moffit, F. H. 

Data on Chitina Valley, upper Tanana and \Yhite River basins, eastern half of Kenai Peninsula, and Seward 

Peninsula, used in ..:ompiling manuscript map of Alaska. 

Munn,M.J. 

Burgettstown-Carnegie, Foxburg-Clarion, Sewickley, and Claysville folios, Pennsylvania. 

Murray, Alexander. 

Data on district between Georgian Bay and the lower extremity of Lake Erie: Rept. Prog. Geol. Survey Canada 

for 1843. 

Data on Bonaventure River district: Rept. Prog. Geol. Survey Canada for 1844, pp. 67-77. 

Data on region of Matane, Ste. Anne, and St. John rivers, Gaspe: Rept. Prog. Geol. Survey Canada for 1845-46, 

pp. 99-118. 

Data on Kaministikwia and Michipicoten rivers, Lake Superior region, Ontario: Rept. Prog. Geol. Survey Canada 

for 1846-47, pp. 47-57. 

Data on Lake Huron region: Rept. Prog. Geol. Survey Canada for 1847-48, pp. 93-124; idem for 1848-49, pp. 

7-46; idem for 1850-51, pp. 13-33. 

Data on :region between Ottawa, St. Lawrence, and Rideau rivers, Ontario: Rept. Prog. Geol. Survey Canada 

for 1851-52, pp. 57-91. 

Data on region between Kingston and Lake Simcoe, Ontario: Rept. Prog. Geol. Survey Canada for 1852-53, pp. 

75-152. 

Data on region between Lake Huron and Ottawa River: Rept. Prog. Geol. Survey Canada for 1853-56, pp. 59-190; 

idem for 1857, pp. 13-27; idem for 1858, pp. 67-104. 

Geologic map of Newfoundland, Montreal, 1877. 

Nathorst, A. G. 

Geologic map of part of northeastern Greenland: Forhandl. Geol. Foren. Stockholm, No. 207, bd. 23, hft. 4, 1901, 

pp. 275-306. 

Newsom, J. F. 

Santa Cruz folio, California (with J. C. Branner and Ralph Arnold). 

Unpublished data on geology of Mount Hamilton region, California. 

Nordenskjold, Otto. 

Geologic map of eastern Greenland: Meddelelser om Gronland, vol. 28, 1909, pp. 151-284. 

Norwood, C. J. 

Geologic map of Kentucky, compiled by J. B. Hoeing; Kentucky Geol. Survey, 1907. 

O'Harra, C. C. 

Aladdin, Devils Tower, and Belle Fourche folios, Black Hills, South Dakota (with N. H. Darton). 

Ordonez, Ezequiel. 

Contributed to geologic map of Mexico compiled under the direction of J. G. Aguilera. 

Osann, A. 

Data on Ottawa Valley: Ann. Rept. Geol. Survey Canada for 1899, vol. 12, Rept. 0. 

O'Sullivan, Owen. 

Data on the west coast of James Bay, Ontario, Quebec, and Northwest Territory: Summ. Rept. Geol. Survey 

Canada for 1904, pp. 173-179. 

Data on the coast of Hudson Bay from York Factory to Severn River, Northwest Territory and Quebec: Summ. 

Rept. Geol. Survey Canada for 1905, pp. 73-76. 

Data on Canadian Northern Railway route between Split Lake and Fort Churchill, Northwest Territory: Summ. 

Rept. Geol. Survey Canada for 1906, pp. 99-102. ' 

Data on National TrafLscontinental Railway route, from La Tuque westward, Quebec: Summ. Rept. Geol. Survey 

Canada for 1907, pp. 67-68. 

Data on west coast .of Hudson Bay from Severn River to Cape Henrietta Maria, Northwest Territory: Summ. 

Rept. Geol. Survey Canada for 1908, pp. 93-94. 

Pack, R. W. 

Manuscript geologic map of part of Diablo Range, California. 

Paige, Sidney. 

Manuscript geologic maps of Llano and Burnet quadrangles, Texas (with A. C. Spencer and F. II. Kay). 

Data on Matanuska Valley, used in compiling manuscript map of Alaska. 

Palache, Charles. 

Bradshaw Mountains folio, Arizona (with T. A. Jaggar, jr.), and Franklin Furnace folio, New Jersey (with A. C. 

Spencer, R. D. Salisbury, and H. B. Kiimmel). 

Pardee, J. T. 

Unpublished notes on western Montana. 

Parks, W. A. 

Data on country east of Xipigon Lake and River, Ontario: Summ. Rept. Geol. Survey Canada for 1901, pp. 105-107. 

Data on region northeast of Lake ~ipigon, Ontario: Summ. Rept. Geol. Survey Canada for 1902, pp. 213-222. 

Data on region north of Lake Timiskaming, Ontario: Summ. Rept. Geol. Survey Canada for 1904, pp. 198-225. 

Data on vallPy of Tobique River, New Brunswick: Summ. Rept. Geol. Survey Canada for 1905, pp. 115-117. 
CONTRIBUTORS. 49 

Peale, A. C. 

Three Forks folio, Montana. 

Pepperberg, L. J. 

Unpublished notes on the Sweetgrass Hills, Bearpaw Mountains, and Little Rocky Mountain districts of northern 

Montana. 

Data on Milk River coal field, Montana, used in compiling map of the coal-bearing Cretaceous and Tertiary. 

Geologic map of Milk River coal field, Montana: Bull. U.S. Geol. Survey No. 381, 1910, pp. 82-107. 

Phalen, W. C. 

Johnstown folio, Pennsylvania. 

Manuscript geologic map of Ellijay quadrangle, Georgia (with Laurence La Forge). 

Manuscript geologic map of Kenova quadrangle, Ohio-West Virginia-Kentucky. 

Pirsson, L. V. 

Geologic map of Little Rocky Mountains, Montana: Jour. Geology, vol. 4, 1896, pp. 399-428 (with W. H. Weed). 

Geologic map of Judith Mountains, Montana: Eighteenth Ann. Rept. U.S. Geol. Survey, pt. 3, 1898, pp. 446-616 

(with \V. H. Weed). 

Notes on the Bearpaw Mountains, Montana: Am. Jour. Sci., 4th ser., vol. 1, 1896, pp. 283-301, 351-362; vol. 2, 

1896, pp. 136-148, 188-199 (with W. H. Weed). 

Pishel, M. A. 

Data on Cheyenne River and Standing Rock Indian reservations, North and South Dakota, used in compiling 

map of the coal-bearing Cretaceous and Tertiary. 

Poole, H. S. 

Geologic map of Pictou coal field, New Brunswick: Ann. Rept. Geol. Survey Canada for 1901, vol. 14, Rept. M. 

Data on Chignecto Bay, New Brunswick and Nova Scotia: Summ. Rept. Geol. Survey Canada for 1902, pp. 379-384. 

Data on the Nanaimo-Comox coal field, British Columbia: Summ. Rept. Geol. Survey Canada for 1905, pp. 55-59. 

Powell, J. W. 

Geologic maps of part of Arizona, Utah, Colorado, Wyoming, and South Dakota: Repts. U. S. Geog. and Geol. 

Survey Rocky Mtn. Region, 1872-1880. 

Pratt, J. H. 

Geologic map of western North Carolina, based on data furnished by Arthur'Keith: North Carolina Geol. Survey, 

vol. 1, 1905 (with J. V. Lewis). 

Prindle, L. M. 

Data on Alaska Range and on Yukon-Tanana region (based on earlier work of J. E. Spurr) used in compiling 

manuscript map of Alaska. 

Prosser, C. S. 

Cottonwood Falls folio, Kansas (with J. W. Beede). 

Pumpelly, Raphael. 

Geologic map of Greylock and Hoosac mountains, Massachusetts: Mon. U. S. Geol. Survey, vol. 23, 1894 (with 

T. N. Dale and J. E. Wolff). 

Purdue, A. H. 

Winslow folio, northern Arkansas; and manuscript maps of adjacent Eureka Springs, Harrison, Hot Springs, and 

Caddo Gap quadrangles. 

Ransome, F. L. 

Manuscript geologic map of Ray quadrangle, southeastern Arizona (with J. B. Umpleby). 

Globe and Bisbee folios, southern Arizona. 

Geologic map of Cceur d'Alene district, Idaho: Prof. Paper U.S. Geol. Survey No. 62, 1908 (with F. C. Calkins). 

Mother Lode district folio, California. 

Reagan, A. B. 

Geologic map of part of Olympic Peninsula, Washington: Trans. Kansas Acad. Sci., vol. 22, p. 160. 

Richards, R. W. 

Geologic maps of phosphate areas in southeastern Idaho, northeastern Utah, and adjacent parts of Wyoming: 

Bull. U. S. Geol. Survey No. 430, 1910, pp. 457-551 (with H. S. Gale). 

Data on Bull Mountains coal field, Montana, used in compiling map of the coal-bearing Cretaceous and Tertiary. 

Richardson, G. B. 

Data on Trinidad, Colorado, and Book Cliffs coal fields, Colorado and Utah, and on Colob Plateau, southern 

Utah, used in compiling map of the coal-bearing Cretaceous and Tertiary. 

Reconnaissance map of the trans-Pecos region, Texas and New Mexico: Bull. Univ. Texas Min. Survey No.9 (23), 

1904. 

Indiana folio, Pennsylvania; El Paso folio, Texas; and manuscript map of Van Horn quadrangle, Texas. 

Geologic map of part of the Book Cliffs coal field, Colorado and Utah: Bull. U.S. Geol. Survey No. 371, 1909. 

Geologic map of Franklin Mountains, Texas and New Mexico: Bull. U.S. Geol. Survey No. 285, 1906, pp. 146--149. 

Richardson, James. 

Geologic map of region south of St. Lawrence River, between Chaudiere and Trois Pistoles rivers, Quebec: Rept. 

Prog. Geol. Survey Canada for 1866-69, pp. 119-141. 

48011°-12-4 
50 INDEX TO THE STRATIGRAPHY OF NORTH A.l\1ERICA. 

Richardson, James-Continued. 

Data on region along north shore of lower St. Lawrence: Rept. Prog. Geol. Survey Canada for 1866-1869, pp. 

305-311. 

Data on country north of Lake St. John, Quebec: Rept. Prog. Geol. Survey Canada for 1870-71, pp. 283-308. 

Map of coal fields of east coast of Vancouver Island: Rept. Prog. Geol. Survey Canada for 1871-72, pp. 73-98. 

Data on Vancouver and Charlotte Islands: Rept. Prog. Geol. Survey Canada for 1872-73, pp. 32-65, 84-86. 

Data on British Columbia: Rept. Prog. Geol. Survey Canada for 1873-74, pp. 94-102; idem for 1874-75, pp. 71-83; 

idem for 1876-77, pp. 160-192, with geologic map of coal fields of northeastern part of Vancouver Island. 

Data on Magdalen Islands: Rept. Prog. Geol. Survey Canada for 1879-80, Rept. G. 

Data on Anticosti and Mingan islands: Rept. Prog. Geol. Survey Canada for 1853-56, pp. 191-245. 

Data on Gaspe Peninsula: Rept. Prog. Geol. Survey Canada for 1857, pp. 29-93; idem for 1858, pp. 105-169. 

Data on eastern townships of Quebec: Rept. Prog. Geol. Survey Canada for 1863-66, pp. 29-45. 

Robb, Charles. 

Geologic map of York, Carleton, and Victoria counties, New Brunswick: Rept. Prog. Geol. Survey Canada for 

1866-1869, pp. 173-209. 

Data on northwestern New Brunswick: Rept. Prog. Geol. Survey Canada for 1870-71, pp. 241-251. 

Data on Sydney coal field, Cape Breton, Nova 8cotia: Rept. Prog. Geol. Survey Canada for 1872-73, pp. 238-290. 

Data on Cape Breton, Nova Scotia: Rept. Prog. Geol. Survey Canada for 1873-74, pp. 171-188; idem for 1874-75, 

pp. 166-266 (with geologic map of Cape Dauphin district). 

Robinson, H. H. 

Geologic map of Connecticut: Connecticut Geol. and Nat. IIist. Survey, 1906 (with H. E. Gregory). 

Rogers, W. B. 

Geologic map of Virginia and West Virginia: Geology of the Virginias, 1884. 

Ruedemann, Rudolph. 

Geologic map of Elizabethtown and Port Henry quadrangles, New York: Bull. Univ. New York No. 138, 1910 

(with J. F. Kemp). 

Russell, I. C. 

Geologic map of part of Cascade Mountains, northern Washington: Twentieth Ann. Rept. U. S. Geol. Survey, 

pt. 2, 1900, pp. 83-210. 

Geologic maps of Newark system in eastern United States: Bull. U.S. Geol. Survey No. 85, 1892. 

Ann Arbor folio, Michigan (with Frank Leverett). 

Geologic map of Lake Lahontan Quaternary deposits of western Nevada and adjacent parts of California and 

Oregon: Mon. U. S. Geol. Survey, vol. 11, 1885. 

Geologic map of central Washington: Bull. U. S. Geol. Survey No. 108, 1893. 

Geologic map of part of southern Idaho: Bull. U.S. Geol. Survey No. 199, 1902. 

Sanford, Samuel. 

Geologic map of Florida: Second Ann. Rept. Florida Geol. Survey, 1909 (with G. C. Matson and F. G. Clapp). 

Safford, J. M. 

Geologic map of Tennessee, published by the State geologist, 1896. 

Salterain y Legarra, Pedro. 

Geologic map of Cuba: Bol. Com. del Mapa Geol. de Espana, vol. 7, 1880, pp. 161-225; vol. 8; 1881 (with Manuel 

Ferm1ndez de Castro). 

Sapper, Carl. 

Geologic maps of Central America and adjacent portions of Mexico: Petermanns Mitt., Erganzungsband 24, 27, 

and 32; Bull. Geol. Inst. Mexico No.3, p. 7. 

Savage,T.E. 

Geologic map of Iowa, compiled for Iowa Geol. Survey for report of 1905 (1906). 

Schrader, F. C. 

Data on lower Copper River, Prince William Sound, Chitina Valley, upper Tanana and '\\lhite River basins, upper 

Copper River region, Chandalar and upper Koyukuk, main Koyukuk Valley, Endicott Range, and Anaktuvuk 

and Colville River valleys, used in compiling manuscript map of Alaska. 

Geologic map of part of western Arizona: Bull. U.S. Geol. Survey No. 397, 1909. 

Manuscript geologic map of Patagonia and Nogales quadrangles, southern Arizona (with J. M. Hill). 

Data on San Juan coal region, New Mexico, used in compiling map of the coal-bearing Cretaceous and Tertiary. 

Geologic map of Durango-Gallup coal field, New Mexico and Colorado: Bull. U. S. Geol. Survey No. 285, 1906, 

pp. 241-257 (with M. K. Shaler). 

Independence folio, Kansas. 

Schultz, A. R. 

Geologic map of southern part of Rock Springs coal field, southern Wyoming: Bull. U. S. Geol. Survey No. 381, 

1910, pp. 214-281. 

Geoloi'ic map of northern part of Rock Springs coal field, Sweetwater County, Wyoming: Bull. U. S. Geol. 

Survey No. 341, 1909, pp. 256-282. 
CONTRIBUTORS. 51 

Schultz, A. R.-Continued. 

Data on northern Uinta County and Rock Springs coal fields, Wyoming, used in compiling map of the coal-bearing 

Cretaceous and Tertiary. 

Geologic map of part of central Uinta County, Wyoming: Bull. U. S. Geol. Survey No. 316, 1907, pp. 212-241. 

Sellards, E. H. 

Geologic map of Florida, by G. C. Matson, F. G. Clapp, and Samuel Sanford: Second Ann. Rept. Florida Geol. 

Survey, 1909. 

Selwyn, A. R. C. 

Data on Quebec and Nova Scotia: Rept. Frog. Geol. Survey Canada for 1870-71, pp. 252-282. 

Data on British Columbia: Rept. Frog. Geol. Survey Canada for 1871-72, pp. 16-72. 

Data on country from Lake Superior to Fort Garry, by English and Winnipeg rivers: Rept. Frog. Geol. Survey 

Canada for 1872-73, pp. 8-18. 

Data on Colchester County, Nova Scotia: Rept. Frog. Geol. Survey Canada for 1872-78, pp. 19-31. 

Data on Saskatchewan and Alberta: Rept. Frog. Geol. Survey Canada for 1873-74, pp. 17-62. 

Data on British Columbia: Rept. Frog. Geol. Survey Canada for 1875-76, pp. 28-86. 

Data on Quebec group: Rept. Frog. Geol. Survey Canada for 1877-78, Rept. A. 

Data on Souris River valley, Manitoba: Rept. Frog. Geol. Survey Canada for 1879-80, Rept. A. 

Data on southeastern portion of Province of Quebec: Rept. Frog. Geol. Survey Canada for 1880-82, Rept. A. 

Geologic map of the Dominion of Canada, from surveys 1842-1882, scale 45 miles to 1 inch. 

Shaler, M. K. 

Data on San Juan coal region, New Mexico, used in compiling map of the coal-bearing Cretaceous and Tertiary. 

Geologic map of the western part of the Durango-Gallup coal field, New Mexico and Colorado: Bull. U.S. Geol. 

Survey No. 316, 1907, pp. 376-426. 

Geologic map of Durango-Gallup coal field, )lew Mexico and Colorado: Bull. U. S. Geol. Survey No. 285, 1906, 

pp. 241-257 (with F. C. Schrader). 

Shaler, N. S. 

Geologic map of ~arragan~ett Basin, Rhode Island: Mon. U. S. Geol. Survey, vol. 33, 1899 (with A. F. Foerste 

and J. B. Woodworth). 

Geologic map of Richmond area, Virginia: Nineteenth Ann. Rept. U. S. Geol. Survey, 1899, pp. 385-520 (with 

J. B. ·woodworth). 

Shattuck, G. B. 

St. Marys folio, Maryland-Virginia, and Patuxent folio, Maryland-District of Columbia (with B. L. Miller). 

Shaw, E. W. 

Data on Big Muddy coal field, Wyomi!lg, used in compiling map of the coal-bearing Cretaceous and Tertiary. 

Burgettstown-Carnegie and Foxburg-Clarion folios, Pennsylvania. 

Siebenthal, C. E. 

Geologic map of Laramie Basin, Wyoming: Bull. U. S. Geol. Survey No. 364, 1909 (with N. II. Darton). 

Joplin (Missouri) and Laramie-Sherman (Wyoming) folios. 

Notes on San Luis Valley, Colorado: Water-Supply Paper U. S. Geol. Survey )i"o. 240, 1910. 

Manuscript geologic map of Uncompahgre Valley, Colorado. 

Sievers, Wilhelm. 

Geologic maps of northern Venezuela, South America: Petermanns Geog. l\Iitt., vol. 42, pt. 6, p.127, 1896; Geog. 

Abhandl., Bd. 3, 1889, p. 239. 

Sloan, Earle. 

Data on the Tertiary and Cretaceous of South Carolina, used in compiling map of Atlantic Coastal Plain. 

Geologic map of South Carolina: Bull. South Carolina Geol. Survey, 4th ser., No. 2, 1908. 

Smith, A. D. W. 

Geologic map of Pennsylvania, compiled under direction of J. P. I.esley: Summary Rept. Second Geol. Survey 

Pennsylvania, 1893. 

Smith, C. D. 

Data on Fort Peck Indian Reservation and Miles City coal fields, Montana, used in compiling map of the coal· 

bearing Cretaceous and Tertiary. 

Geologic map of Fort Peck Indian Reservation lignite field, Montana: Bull. U. S. Geol. Survey No. 381, 1910, 

pp. 40-59. . 

Smith, E. A. 

Geologic map of Alabama: Geol. Survey Alabama, 1894. 

Smith, E. E. 

Data on Great Divide Basin coal field, Wyoming used in compiling map of the coal-bearing Cretaceous and 

Tertiary. 

Geologic map of eastern part of Great Divide Basin coal field, \Vyoming: Bull. U. S. Geol. Survey No. 341, 1909, 

pp. 220-242. 

Smith, G. 0. 

Geologic map of Perry Basin,.southeastern Maine: Prof. Paper U.S. Geol. Survey No. 35,1905 (with David White). 

Map of the granites of Maine: Bull. U.S. Geol. Survey No. 313, 1906 ("with E. S. Bastin and C. W. Brown). 
52 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Smith, G. 0.-Continued. 

Geologic map of part of northern Washington: Bull. U.S. Geol. Survey No. 235, 1904 (with F. C. Calkins). 

Geologic map of New England, compiled by G. 0. Smith and E. S. Bastin, for geologic map of North America: 

International Geological Congress, 1906; used in part. 

Ellensburg, Mount Stuart, and Snoqualmie folios, Cascade Range, Washington; Tintic folio, central Utah; Penobscot Bay folio, southeastern Maine; and Tacoma· folio, vYashington. · 

Geologic map of Fox Islands, Maine: Bull. Colby Coli., vol. 1, supplement, 1901, pp. 1-53. 

Smith, P. S. 

Data on Yukon River and Norton Bay regions and Seward Peninsula, used in compiling manuscript map of Alaska. 

Smith, W. H. C. 

Geologic map of Rainy River district, Ontario: Ann. Rept. Geol. Survey Canada for 1890-91, vol. 5, Rept. G. 

Smith, W. S. T. ' 

Geologic map of Santa Catalina Island, southern California: Proc. California Acad. Sci., 3d ser., vol. 1, 1897, pp. 

1-71. 

Geologic map of San Clemente Island, southern California: Eighteenth Ann. Rept. U. S. Geol. Survey, pt. 2, 

1898, pp. 465-494. 

Hartville folio, Wyoming; .Joplin folio, southwestern Missouri (with C. E. Siebenthal); and Edgemont folio, 

South-Dakota-Nebraska (with N.H. Darton). 

Spencer, A. C. 

Manuscript geologic maps of Llano and Burnet quadrangles, Texas (with Sidney Paige and F. H. Kay). 

Geologic reconnaissance of Cuba (with C. W. Hayes and T. W. Vaughan): Rept. Military Governor Cuba for 1901. 

La Plata and Rico folios, Colorado; Franklin Furnace folio, New Jersey. 

Geologic map of Encampment district, southern Wyoming: Prof. Paper U.S. Geol. Survey No. 25, 1904. 

Data on southeastern Alaska, lower Copper River, Prince William Sound, and Chitina Valley, used in compiling 

manuscript map of Alaska. 

Spencer, J. W. 

Data on country between upper Assiniboine River and Lakes Winnipegosis and Manitoba: Rept. Prog. Geol. 

Survey Canada for 1874-75, pp. 57-70. 

Spurr, J. E. 

Geologic map of south end of Oquirrh Mountains, Utah: Sixteenth Ann. Rept. U. S. Geol. Survey, pt. 2, 1895, 

pp. 343-455 (with S. F. Emmons). 

Geologic map of Aspen district, Colorado: Mon. U. fl. Geol. Survey, vol. 31, 1898. 

Geologic map of Silver Peak quadrangle, Nevada, based on data furnished by H. W. Turner: Prof. Paper U. S. 

Geol. Survey No. 55, 1906. 

Data on Alaska Peninsula, Susitna Basin, Kuskokwim Valley, and Bristol Bay region, used in compiling manuscript map gf Alaska. 

Reconnaissance map of Nevada south of fortieth parallel: Bull. U. S. Geol. Survey No. 208, 1903. 

Stanton, T. W. 

Data on Kachemak Bay region and Alaska Peninsula, used in compiling manuscript map of Alaska. 

Notes on distribution of Triassic, Jurassic, and Cretaceous throughout western United States from northern Mexico 

to Canada and in Alaska, for this map. 

Stebinger, Eugene. 

Geologic map of eastern part of Little Snake River coal field, Wyoming: Bull. U. S. Geol. Survey No. 381, 1910, 

pp. 186-213 (with M. W. Ball). 

Steenstrup, K. J. V. 

Geologic map of part of the west coast of Greenland: Meddelelser om Gronland, vol. 4, 1893, pp. 173-242 (with 

R. R. I. Hammer). 

Geologic map of part of southern Greenland: :\feddelelser om Gronland, vol. 2, 1881, pp. 27-41 (with G. F. Holm). 

Stephenson, L. W. 

Data on and manuscript maps of the Cretaceous of Sonth Carolina, Georgia, and Alabama, and of Tertiary of South 

Carolina, used in compiling map of Atlantic and Gulf Coastal Plain. 

Sterrett, D. B. 

Manuscript geologic map of Kings Mountain and Gaffney quadrangles, North Carolina-South Carolina. 

Stone, R. W. 

Elders· Ridge and Waynesburg folios, Pennsylvania. 

Data on Musselshell River (Montana) and Powder River (Wyoming) coal field, used in compiling map of the coalbearing Cretaceous and Tertiary. 

Data on Kachemak Bay region, used in compiling manuscript map of Alaska. 

Stose, G. W. 

Assisted largely in compiling the map of North America and directing its drafting and publication. 

Mercersburg-Chambersburg and Pawpaw-Hancock folios and manuscript maps of Carlisle, Fairfield, and Gettysburg quadrangles, southern Pennsylvania, Maryland, and West Virginia. 

Geologic map of part of South Mountain, Pennsylvania: Bull. U. S. Geol. Survey No. 430, 1910, pp. 54-63. 

Manuscript map of Apishapa quadrangle, Colorado. 
CONTRIBUTORS. 53 

Swartz, C. X. 

Pawpaw-Hancock folio, West Virginia-Maryland-Pennsylvania (with G. W. Stose). 

Taff, J. A. 

Data on Sheridan coal field, Wyoming, on Book Cliffs and Wasatch Plateau coal fields, Utah, and on San Juan 

coal region, New Mexico, used in compiling map of the ,coal-bearing Cretaceous and Tertiary. 

Geologic map of the McAlester-Lehigh coal field, Oklahoma: Nineteenth Ann. Rept. U. S. Geol. Survey, pt. 3, 

1899, pp. 423-602. 

Geologic maps of Arbuckle and Wichita mountains, and coal fields of Oklahoma: Nineteenth Ann. Rept. U. S. 

Geol. Survey, pt. 3, 1899, pp. 423-583; Prof. Paper U. S. Geol. Survey No. 31, 1904. 

Geologic map of p11rt of the eastern Choctaw coal field, Oklahoma: Twenty-first Ann. Rept. U. S. Geol. Survey 

pt. 2, 1900, pp. 257-311 (with G. I. Adams). 

Buckhannon and Piedmont folios, Appalachian region; Coalgate, Atoka, Tishomingo, Tahlequah, and Muscogee 

folios, and manuscript maps of McAlester, Winding Stair, Antlers, Tuskahoma, Canadian, Sansbois, and Sallisaw quadrangles, Oklahoma. 

Tarr, R. S. 

Watkins Glen-Catatonk folio, New York (with H. S. Williams and E. M. Kindle). 

Data on Yakutat Bay and Alsek River region (making use of earlier work of I. C. Russell), used in compiling 

manuscript map of Alaska. 

Thoroddsen, Th. 

Geologic map of Iceland, I.ondon, 1901. 

Tippenhauer, L. G. 

Notes on Haiti used in compiling map of WElllt Indies: Petermanns Mitt., Bel. 45, 1899, pp. 2-5-29, 1-53-155, 201-204; 

Bd. 47, 1901, pp. 121-127, 169-178, 193-199. 

Todd,J.E. 

Olivet, Parker, Mitchell, Alexandria, Huron, De Smet, Elk Point, and Aberdeen-Redfield folios, South Dakota. 

Torrance, J. F. 

Data on Ottawa County, Quebec: Rept. Prog. Geol. Survey Canada for 1882-1884, Rept. J. 

Torre, Carlos de la. 

Notes on the paleontology of Cuba: Anales Acad. ciencias medicas, fisicas y naturales de la Habana, Revista 

cientifica, vol. 47, July, 1910, pp. 1-33, with plates. 

Tower, G. W. 

Butte folio, Montana, and Tintic folio, Utah. 

Turner, H. W. 

Geologic map of Tertiary deposits in Silver Peak region, Nevada: Twenty-first Ann. Rept. U. S. Geol. Survey, 

pt. 2, 1901, pp. 191-226. 

Geologic map of older formations of Sierra Nevada, California: Seventeenth Ann. Rept. U. S. Geol Survey, pt. 1, 

1896, pp. 521-761. 

Placerville, Jackson, Marysville, Smartsville, Downieville, Sonora, Bidwell Bar, and Big Trees folios, Sierra. 

Nevada, California. 

Manuscript maps of Silver Peak quadrangle, Nevada, and Yosemite quadrangle, California. 

Tyrrell, J. B. 

Geologic map of central Alberta: Ann. Rept. Geol. Survey Canada for 1886, vol. 2, Rept. E. 

Data on northwelltern Manitoba: Ann. Rept. Geol. Survey Canada for 1887-88, vol. 3, Rept. E. 

Geologic map of northwestern Manitoba: Ann. Rept. Geol. Survey Canada for 189Q-91, vol. 5, Rept. E. 

Data on and geologic map of country between Athabasca Lake and Churchill River: Ann. Rept. Geol. Survey 

Canada for 1895, vol. 8, Rept. D (with D. B. Dowling). 

Data on Doobaunt, Kazan, and Ferguson rivers and northwest coast of Hudson Bay: Ann. Rept. Geol. Survey 

Canada for 1896, vol. 9, Rept. F. 

Data on northern Manitoba: Summ. Rept. Geol. Survey Canada for 1897, pp. 34-38. 

Data on Yukon and adjacent parts of British Columbia: Summ. Rept. Geol. Survey Canada for 1898, pp. 36-46. 

Geologic map of Lake Winnipeg and vicinity: Ann. Rept. Geol. Survey Canada for 1898, vol. 11, Rept. G (with 

D. B. Dowling). 

Geologic map of northeastern Saskatchewan and adjacent parts of Keewatin: Ann. Rept. ?eol. Survey Canada 

·for 1900, vol. 13, Rept. F. · 

Udden,J. A. 

Data on the Cretaceous of Texas, used in compiling the map of the Atlantic and Gulf Coastal Plain. 

Geologic map of portion of southwestern Texas, from Lone Mountains to Chisos district: Repts. Univ. Texas Min. 

Survey, 1904 (with B. F. Hill). 

Ulrich, E. 0. 

Notes on distribution of Paleozoic formations, particularly Cambrian, Ordovician, and Silurian, in eastern United 

States. 

Columbia folio, Tennessee, and Fayetteville folio, Missouri-Arkansas. 
54 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Umpleby, J. B. 

Manuscript geologic map of Lemhi County, Idaho. 

Manuscript geologic map of Ray quadrangle, southeastern Arizona (withF . .L. Ransome). 

Van Rise, C. R. 

Member of committee on pre-Cambrian nomenclature. 

Geologic map of Lake Superior region, compiled by C. R. Van Hi~e and C. K. Leith: ::\fon. U.S. Geol. Survey, 

vol. 52, 1911. 

Vaughan, T. W. 

Nueces, Uvalde, and Austin folios, and manuscript map of Brackett quadrangle, southern Texas. 

Geologic map of south Atlantic and Gulf Coastal Plain, compiled under the direction of T. W. Vaughan from 

cooperative surveys with States. 

Geologic reconnaissance of Cuba: Rept. Military Governor of Cuba for 1901 (with C. W. Hayes and A. C. Spencer). 

Veatch, A. C. 

Data on southern Uinta County and Hanna coal fields, Wyoming, used in compiling map of the coal-bearing 

Cretaceous and Tertiary. 

Geologic map of northern Louisiana and southern Arkansas: Prof. Paper U. S. Geol. Survey No. 46, 1903. 

Geologic map of part of southwestern Wyoming: Prof. Paper U.S. Geol. Survey No. 56, 1907. 

Geologic map of east-central Carbon County, Wyoming: Bull. U. S. Geol. Survey No. 316, 1907, pp. 244-260. 

Veatch, Otto. 

Data on the Cretaceous and Tertiary of Georgia, used in compiling map of Atlantic Coastal Plain. 

Vennor, H. G. 

Geologic map of parta of Hastings, Peterborough, Addington, and Frontenac counties, Ontario: Rept. Prog. Geol. 

Survey Canada for 1866-1869, pp. 143-171. 

Data on Frontenac, Leeds, Lanark, and Addington counties, Ontario: Rept. Prog. Geol. Survey Canada for 

1870-71, pp. 309-315; idem for 1871-72, pp. 12{}-141; idem for 1872-73, pp. 136-179; idem for 1873-74, pp. 

103-146; idem for 1874-75, pp. 105-165. 

Data on Renfrew, Pontiac, and Ottawa counties: Rept. Prog. Geol. Survey Canada for 1876-77, pp. 244-320. 

Geologic map of Lanark County, Ontario: Rept. Prog. Geol. Survey Canada for 1874-75. 

Walcott, C. D. 

Notes on Rocky Mountains of northern Montana: Bull. Geol. Soc. America, vol. 17, 1906, pp. 1-28. 

Geologic map of Belt terrane in Montana: Bull. Geol. Soc. America, vol. 10, 1899, pp. 199-244. 

Geologic map of eastern part of Colorado Canyon: Fourteenth Ann. Rept. U.S. Geol. Survey, pt. 2, 1894, pp. 497-519. 

Walker, T. L. 

Data on Muskoka district, Ontario: Summ. Rept. Geol. Survey Canada for 1905, pp. 84-86. 

Wall, G. P. 

Geologic maps of Trinidad and part of Venezuela: Jour. Geology, London Geol. Soc., 1860, p. 470; Appendix M, 

Geology of Trinidad (with J. G. Sawkins). 

Washbtll'Ile, C. W. 

Data on South Park and Canon City coal fields, Colorado, and on Bighorn Basin coal fields, Wyoming and Montana, used in compiling map of the coal-bearing Cretaceous and Tertiary. 

Geologic map of South Park coal field, central Colorado: Bull. U. S. Geol. Survey No. 381, 1910, pp. 307-316. 

Geologic map of Canon City coal field, Colorado: Bull. U. S. Geol. Survey No. 38:t, 1910, pp. 341-378. 

Watson, T. L. 

Unpublished data on Paleozoic and Cambrian rocks in Virginia. 

Weaver, C. E. 

Manuscript map of Napa quadrangle, California. 

Webster, Arthur. 

Data on west coast of Vancouver Island: Summ. Rept. Geol. Survey Canada for 1902, pp. 54-76. 

Weed, W.H. 

Geologic map of Little Rocky Mountains, Montana: Jour. Geology, vol. 4, 1896, pp. 399-428 (with L. V. Pirsson). 

Geologic map of Judith Mountains, Montana: Eighteenth Ann. Rept. U.S. Geol. Survey, pt. 3, 1898, pp. 446-616 

(with L. V. Pirsson). 

Notes on Bearpaw Mountains, Montana: Am. Jour. Sci., 4th ser., vol.1, 1896, pp. 283-301, 351-362; vol. 2, 1896, 

pp. 136-148, 188-199 (with L. V. Pirsson). 

Geologic map of Elkhorn district, Montana: Twenty-second Ann. Rept. U. S. Geol. Survey, pt. 2, 1901, pp. 399-550. 

Livingston, Butte, Yellowstone Park, Fort Benton, and Little Belt Mountains folios, Montana. 

Manuscript maps of parts of Fort Logan and Helena quadrangles, Montana. 

Weeks, F. B. 

Manuscript map of part of northwestern Utah. 

Geologic map of Uinta Range, Utah: Bull. Geol. Soc. America, vol. 18, 1907, pp. 427-448. 

Notes on Silver Peak quadrangle and other portions of Nevada. 

Geologic map of Fort Hall mining district, southeastern Idaho: Bull. F. S. Geol. Survey No. 340, 1908, pp. 175-183 

(with V. 0. Heikes). 
CONTRIBUTORS. 55 

Wegemann, C. H. 

Data on Buffalo coal field, Wyoming, used in compiling map of the coal-bearing Cretaceous and Tertiary. 

Weller, Stuart. 

Geologic map of Illinois: Bull. Illinois State Geol. Survey No.6, 1907. 

Raritan folio, New Jersey (with H. B. Kti.mmel, W. S. Bayley, and R. D. Salisbury). 

Wheeler, G. M. 

Geologic maps of parts of Nevada, Arizona, Utah, Colorado, and New Mexico: Repts. U. S. Geog. Surveys W. 

100th Mer. 

White, David. 

Geologic map of Perry Basin, southeastern Maine: Prof. Paper U.S. Geol. Survey No. 35, 1905 (with G. 0. Smith). 

Notes on distribution of continental Carboniferous. 

White, I. C. 

Geologic maps of parts of West Virginia: West Virginia Geol. Survey, county reports, 1906-1910. 

White, James. 

Member (part of the time) of committee on pre-Cambrian nomenclature. 

Wilder, F. A. 

Geologic map of Iowa compiled by T. E. Savage: Rept. Iowa Geol. Survey for 1905 (1906). 

Willard, D. E. 

Jamestown-Tower, and Casselton-Fargo folios, North Dakota-:Minnesota. 

Williams, H. S. 

Watkins Glen-Catatonk folio, New York (with E. M. Kindle and R. S. Tarr). 

Willis, Bailey. 

Compiler of map of North America; contributed local details in many districts. 

Geologic map of part of Rocky Mountains, northern Montana: Bull. Geol. Soc. America, vol. 13, 1902, pp. 305-352. 

Chairman of committee on pre-Cambrian nomenclature. 

Manuscript map of Jonesville quadrangle, Tennessee-Kentucky. 

Geologic map of coal-bearing Cretaceous and Tertiary of central-western States (compiled by Bailey Willis and 

M. R. Campbell). 

Geology of Lower California, compiled from published notes of Gabb, Merrill, Emmons, Lindgren, Fairbanks, 

and Lawson. 

Piedmont folio, Appalachian region (with N. H. Darton and J. A. Taff); Tacoma folio, Washington (with G. 0. 

Smith). 

Wilson, A. W. G. 

Data on country west of Nipigon Lake and River, Ontario: Summ. Rept. Geol. Survey Canada for 1901, pp. 96--103. 

Data on region about headwaters of Albany River, Ontario: Summ. Rept. Geol. Survey Canada for 1902, pp. 

203-206. 

Data on Lake Nipigon and Thunder Bay region, Ontario: Summ. Rept. Geol. Survey Canada for 1908, pp. 95-96. 

Wilson, M. E. 

Data on region east of Lake Timiskaming, Quebec: Summ. Rept. Geol. Survey Canada for 1907, pp. 59-63. 

Data on Lake Opasatikaand the Height of Land, Quebec: Summ. Rept. Geol. Survey Canada for 1908, pp. 121-123. 

Wilson, W. J. 

Data on rivers southwest of James Bay, Ontario: Summ. Rept. Geol. Survey Canada for 1902, pp. 222-240. 

Data on the western part of Abitibi region, Ontario: Summ. Rept. Geol. Survey Canada for 1901, pp. 115-128. 

Data on Nagagami River and other branches of the Kenogami, Ontario: Summ. Rept. Geol. Survey Canada for 

1903, pp. 109-120. 

Data on Little Current and Drowning rivers, Ontario: Summ. Rept. Geol. Survey Canada for 1904, pp. 164-173. 

Data on region between Lake Temagami and Spanish River, Ontario: Summ. Rept. Geol. Survey Canada for 

1905, pp. 82-84. 

Data on the Transcontinental Railway route from Lake Abitibi eastward, Quebec: Summ. Rept. Geol. Survey 

Canada for 1906, pp. 119-123. 

Data on the National Transcontinental Railway from Bell River eastward, Quebec: Summ. Rept. Geol. Survey 

Canada for 1907 pp. 64-66. 

Geologic map of Algoma and Thunder Bay districts, northwestern Ontario: Rept. Geol. Survey Canada, 1909. 

Winchester, D. E. 

Data on Eaton quadrangle, Colorado, used in compiling map of the coal-bearing Gretaceous and Tertiary. 

Notes on the Wind River Basin, Wyoming (with E. G. Woodruff). 

Wolff, J. E. 

Geologic map of Greylock and Hoosac mountains, Massachusetts: Mol). U. S. Geol. Survey, vol. 23, 1894 (with 

Raphael Pumpelly and T. N. Dale). 

Woodruff, E. G. 

Data on Red Lodge (Montana), Bighorn Basin and \Vind River Basin (Wyoming) coal fields, and the Eaton quad· 

rangle, Colorado, used in compiling map of the coal-bearing Cretaceous and Tertiary. 
56 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Woodworth, J. B. 

Geologic map of Narragansett Basin, Rhode Island: Mon. U. S. Geol. Survey, vol. 33, 1899 (with N. S. Shaler 

and A. F. Foerste). 

Geologic map of Richmond area, Virginia: Nineteenth Ann. Rept. U. S. Geol. Survey, 1899, pp. 385-520 (with 

N. S. Shaler). 

Woolsey, L. H. 

Data on Bull Mountains coal field, Montana, used in compiling map of the coal-bearing Cretaceous and Tertiary. 

Beaver folio, Pennsylvania. 

Wright, C. W. 

Data on southeastern Alaska, used in compiling manuscript map of Alaska. 

Wright, F. E. 

Data on southeastern Alaska, used in compiling manuscript map of Alaska. 

Data on Unuk River mining region, British Columbia: Summ. Rept. Geol. Survey Canada for 1905, pp. 46-53. 

Yeates, W. S. 

Geologic map of Georgia: Rept. Geol. Survey Georgia for 1906. 

Young, G. A. 

Data on Lake St. John district, Quebec: Summ. Rept. Geol. Survey Canada for 1900, pp. 143-146. 

Geologic map of Yamaska Mountain, Rouville County, Quebec: Ann. Rept. Geol. Survey Canada for 1904, vol. 16, 

Rept. H. 

Data on Temagami and Rabbit lakes, district "of Nipissing, Ontario: Summ. Rept. Geol. Survey. Canada for 1904, 

pp. 195-198. 

Data on Bathurst district and the Tobique country, Victoria County, New Brunswick: Summ. Rept. Geol. Survey Canada for 1908, pp. 129-131. 

In the subjoined list, arranged by localities, only the names of the authors of 

data used in compiling the map are g1ven. The sources of the data are given 1_nthe preceding list. 

Hettner, Alfred. 

Howe, Erne8t. 

SOUTH AMERICA. 

I Karsten, Hermann. 

Sawkins, J. G. I 

Sievers, Wilhelm. 

Wall, G. P. 

CENTRAL AMERICA (INCLUDING PANAMA) AND WEST INDIES. 

Adan de Yarza, Ramon. 

Fernandez de Castro, Manuel. 

Hayes, C. W. 

Hill, R. T. 

Aguilera, J. G. 

Biise, E. 

Hayes, C. W. 

ALABAMA (H-I 16). 

Ashley, G. H. 

Berry, E. W. 

Butts, Charles. 

Hayes, C. W. 

Matson, G. C. 

Smith, E. A. 

Stephenson, L. W. 

Vaughan, T. W. 

ARIZONA (H-.T 11-12). 

Bancroft, Howland. 

Blake, W. P. 

Campbell, M. R. 

Darton, N. H. 

Dutton, C. E. 

Gregory, H. E. 

Hayden, F. V. 

Howe, Ernest. 

Salterain y Legarra, Pedro. 

Rapper, Karl. --

Spencer, A. C. 

MEXICO. 

I Hill, R. T. 

Ordonez, Ezequiel. 

Tippenhauer, L. G. 

Torre, Carlos de Ia. 

Vaughan, T. W. 

I 

Sapper, Karl. 

Willis, Bailey. 

UNITED STATES EXCEPT ALASKA. 

ARIZONA (H-.T 11-12)-Contlnued. 

Hill, J. M. 

Hill, R. T. 

Jaggar, T. A., jr. 

Lee, W. T. 

Lindgren, Waldemar. 

Palache, ·charles. 

Powell, J. W. 

Ransome, F. L. 

Richardson, G. B. 

Schrader, F. C. 

Wa-lcott, C. D. 

Wheeler, G. M. 

ARKANSAS (I-.T 15). 

I 

Adams, G. I. 

Branner, J. C. 

Collier, A. J. 

ARKANSAS (I-.T 15)-Contlnued. 

Crider, A. F. 

Fuller, M. L. 

Griswold, L. S. 

Purdue, A. H. 

Taff, J. A. 

IDrich, E. 0. 

Vaughan, T. W. 

Veatch, A. C. 

CALIFORNIA (I-K 10-11). 

Anderson, F. M. 

Anderson, Robert. 

Arnold, Ralph. 

Ball, S. H. 

Becker, G. F. 

Branner, J. C. 

Crandall, Roderic. 
CONTRIBUTORS. 

UNITED STATES EXCEPT ALASKA-continued. 

CALIFORNIA (I-X 10-11)-Continued. 

Darton, N. H. 

Diller, J. S. 

Eldridge, G. H. 

Fairbanks, H. W. 

Fisher, C. A. 

Hamlin, Homer. 

Harder, E. C. 

Hayden, F. V. 

Hershey, 0. H. 

Hess, F. I,. 

Hill, R. T. 

Ireland, William. 

Johnson, H. R. 

Lawson, A. C. 

Lindgr!'n, Waldemar. 

Mendenhall, W. C. 

Merriam, J. C. 

Newsom, J. F. 

Pack, R. W. 

Ransome, F. L. 

Russell, I. C. 

Smith, W. S. T. 

Turner, H. W. 

Weaver, C. E. 

Willis, Bailey. 

Winchester, D. E. 

Woodruff, E. G. 

COLORADO (J-X 12-13). 

Beekly, A. L. 

Campbell, M. R. 

Cross, Whitman. 

Darton, N. H. 

Eldridge, G. H. 

Emmons, S. F. 

Fenneman, N. M. 

Gale, H. S. 

George, R. D. 

Gilbert, G. K. 

Goldman, M. I. 

Hills, R. C. 

Howe, Ernest. 

King, Clarence. 

Lee, W. T. 

Powell, J. W. 

Schrader, F. C. 

Shaler, M. K. 

Siebenthal, C. E. 

Spencer, A. C. 

Spurr, J. E. 

Stose, G. W. 

Washburne, C. W. 

Wheeler, G. M. 

Willis, Bailey. 

CONNECTICUT (K 18). 

Bastin, E. S. 

Davis, W. M. 

Emerson, B. K. 

Gregory, H. E. 

Keith, Arthur. 

Robinson, H. H. 

CONNECTICUT (X 18)-Continued. 

Russell, I. C. 

Smith, G. 0. 

DELAWARE (J 18). 

Berry, E. W. 

Bibbins, A. B. 

Clark, W. B. 

Darton, N. H. 

Miller, B. L. 

DISTRICT OF COLUMBIA (J 18). 

Darton, N. H. 

Keith, Arthur. 

Miller, B. L. 

Shattuck, G. B. 

FLORIDA (G-H 16-17). 

Clapp, F. G. 

Matson, G. C. 

Sanford, Samuel. 

Sellards, E. H. 

Vaughan, T. W. 

GEORGIA (H-I 16-17). 

Berry, E. W. 

Hayes, C. W. 

Keith, Arthur. 

La Forge, Laurence. 

McCallie, S. W. 

Phalen, W. C. 

Stephenson, L. W. 

Vaughan, T. W. 

Veatch, Otto. 

Yeates, W. S. 

IDAHO (K-M 11-12). 

Calkins, F. C. 

Drake,.N. F. 

Gale, H. S. 

Gilbert, G. K. 

Hayden, F. V. 

Heikes, V. C. 

Lindgren, Waldemar. 

Ransome, F. L. 

Russell, I. C. 

Weeks, F. B. 

ILLINOIS (J-K 15-16). 

Alden, W. C. 

Ashley, G. H. 

Bain, H. F. 

Burchard, E. F. 

Campbell, M. R. 

Clapp, F. G. 

Fuller, M. L. 

Glenn, L. C. 

Grant, U.S. 

Weller, Stuart. 

INDIANA (J-X 16). 

Alden, W. C. 

, Ashley, G. H. 

INDIANA (J-X 16)-Continued. 

Clapp, F. G. 

Fuller, M. L. 

Gorby, S. S. 

lOW A (K 14-15). 

Ashley, G. H. 

Bain, H. F. 

Burchard, E. F. 

Grant, U.S. 

Savage, T. E. 

Todd,J.E. 

Wilder, F. A. 

KANSAS (J 14-15). 

Beede, J. W. 

Darton, N.H. 

Haworth, Erasmus. 

Prosser, C. S. 

Schrader, F. C. 

KENTUCKY (J 16-17). 

Ashley, G. H. 

Campbell, M. R. 

Glenn, L. C. 

Hoeing, J. B. 

Norwood, C. J. 

Phalen, W. C. 

Willis, Bailey. 

LOUISIANA (H 15-16). 

Adams, G. I. 

Harris, G. D. 

Vaughan, T. W. 

Veatch, A. C. 

MAINE (K-L 19), 

Bastin, E. S. 

Brown, C. W. 

Smith, G. 0. 

White, David. 

MARYLAND (J 17-18). 

Ashley, G. H. 

Berry, E. W. 

Bibbins, A. B. 

Clark, W. B. 

Darton, N. H. 

Keith, Arthur. 

Martin, G. C. 

Matthews, E. B. 

Miller, B. L. 

Russell, I. C. 

Shattuck, G. B. 

Stose, G. W. 

Swartz, C. K. 

Taff,J.A. 

Willis, Bailey. 

MASSACHUSETTS (X 18-19). 

Bastin, E. S. 

Crosby, W. 0. 

57 
58 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

UNITED STATES EXCEPT ALASKA-continued. 

MASSACHUSETTS (K 18-19)-Continued. MONTANA (L-M 11-13)-Continued. NEW MEXICO (H-J 12-13)-Continued. 

Dale, T. N. 

Emerson, B. K. 

Keith, Arthur. 

Pumpelly, Raphael. 

Russell, I. C. 

Smith, G. 0. 

Wolff, J. E. 

MICHIGAN (K-L 16-17). 

Ashley, G. H. 

Lane, A. C. 

Leith, C. K. 

Leverett, Frank. 

Russell, I. C. 

Van Rise, C. R. 

MINNESOTA (K-M 14-15). 

Hall, C. M. 

Leith, C. K. 

Meinzer, 0. E. 

Van Rise, C. R. 

Willard, D. E. 

MISSISSIPPI (H-I 15-16). 

Crider, A. F. 

Matson, G. C. 

Vaughan, T. W. 

MISSOURI (J-K 15-16). 

Adams, G. I. 

Ashley, G. II. 

Buckley, E. R. 

Buehler, H. A. 

Fenneman, N. M. 

Fuller, M. L. 

Keyes, C. R. 

Siebenthal, C. E. 

Smith, \V. S. T. 

Ulrich, E. 0. 

MONTANA (L-M 11-13). 

Barnett, V. H. 

Calkins, F. C. 

Calvert, W. R. 

Campbell, M. R. 

Collier, A. J. 

Darton, N. H. 

Emmons, S. F. 

Fisher, C. A. 

Hayden, F. V. 

Iddings, J. P. 

Lindgren, Waldemar. 

Lupton, C. T. 

O'Harra, C. C. 

Pardee, J. T. 

Peale, A. C. 

Pepperberg, L. J. 

Pirsson, L. V. 

Richards, R. W. 

Smith, C. D. 

Stone, R. W. 

Tower, G. W. 

Walcott, C. D. 

Washburne, C. W. 

Weed, W. H. 

Willis, Bailey. 

Woodruff, E. G. 

Woolsey, L. H. 

NEBRASKA (K 13-15). 

Barbour, E. H. 

Darton, N.H. 

Hayden, F. V. 

Smith, W. S. T. 

Todd, J. E. 

NEVADA (I-K 11). 

Ball, S. H. 

Bard, D. C. 

Emmons, W. H. 

Gilbert, G. K. 

Hague, Arnold. 

King, Clarence. 

Lindgren, Waldemar. 

Russell, I. C. 

Spurr, J. E. 

Turner, H. W. 

Weeks, F. B. 

Wheeler, G. M. 

NEW HAMPSHIRE (K-L 18-19). 

Bastin, E. S. 

Hitchcock, C. H. 

Keith, Arthur. 

Smith, G. 0. 

NEW JERSEY (J-K 18). 

Bascom, Florence. 

Bayley, W. S. 

Berry, E. W. 

Bibbins, A. B. 

Clark, W. B. 

Cook, G. H. 

Darton, N.H. 

Kiimmel, H. B. 

Miller, B. L. 

Palache, Charles. 

Russell, I. C. 

Salisbury, R. D. 

Spencer, A. C. 

Weller, Stuart. 

NEW MEXICO (H-J 12-13). 

Ball, S. H. 

Campbell, ~f. R. 

Darton, N.H. 

Dumble, E. T. 

Dutton, C. E. 

Fisher, C. A. 

Gardner, J. H. 

Gordon, C. H. 

Hayden, F. V. 

Herrick, C. L. 

Hill, R. T. 

Keyes,dJ. R. 

Lee, W. T. 

Meinzer, 0. E. 

Richardson, G. B. 

Schrader, F. C. 

Shaler, M. K. 

Taff,J.A. 

Wheeler, G. M. 

Willis, Bailey. 

NEW YORK (K-L 17-18). 

Clarke, J. M. 

Dale, T. N. 

Darton, N.H. 

Fuller, M. L. 

Grabau, A. W. 

Kemp, J. F. 

Kindle, E. M. 

Kiimmel, H. B. 

Merrill, F. J. H. 

Ruedemann, Rudolph. 

Russell, I. C. 

Tarr, R. S. 

Williams, H. S. 

NORTH CAROLINA (I-J 16-18). 

Berry, E. W. 

Bibbins, A. B. 

Gardner, J. A. 

Keith, Arthur. 

Lewis, J. V. 

Miller, B. L. 

Pratt, J. H. 

Russell, I. C. 

Sterrett, D. B. 

Vaughan, T. W. 

NORTH DAKOTA (L-M 13-14). 

Barnett, V. H. 

Beekly, A. L. 

Campbell, M. R. 

Darton, N. H. 

Hall, C. M. 

Leonard, A. G. 

Fishel, M. A. 

Willard, D. E. 

Willis, Bailey. 

OHIO (J-K 16-17). 

Ashley, G. H. 

Bownocker, J. A. 

Campbell, M. R. 

Newberry, J. S. 

Phalen, W. C. 

Orton, Edward. 

OKLAHOMA (I-J 13-15). 

Adams, G. I. 

Gordon, C. H. 

Gould, C. N. 

Taff, J. A. 

' 
CONTRIBUTORS. 

UNITED STATES EXCEPT ALASKA-continued. 

OREGON (K-L 10-11). 

Diller, J. S. 

Drake, N. F. 

Lindgren, Waldemar. 

Russell, I. C. 

PENNSYLVANIA (J-K 17-18). 

Ashley, G. H. 

Bascom, Florence. 

Berry, E. W. 

Butts, Charles. 

Campbell, M. R. 

Clapp, F. G. 

Clark, W. B. 

Darton, N. H. 

Fuller, M. L. 

Kummel, H. B. 

Lesley, J. P. 

Lines, E. F. 

Martin, G. C. 

Matthews, E. B. 

Miller, B. L. 

Munn, M. J. 

Phalen, W. C. 

Richardson, G. B. 

Russell, I. C. 

Shaw, E. W. 

Smith, A. D. W. 

Stone, R. W. 

Stose, G. W. 

Swartz, C. K. 

Woolsey, L. H. 

• 

RHODE ISLAND (K 19). 

Bastin, E. S. 

Brown, C. W. 

Emerson, B. K. 

Foerste, A. F. 

Shaler, N. S. 

Smith, G. 0. 

Woodworth, J. B. 

SOUTH CAROLINA (I 17). 

Berry, E. W. 

Keith, Arthur. 

Sloan, Earle. 

Stephenson, L. vV. 

Sterrett, D. B. 

SOUTH DAKOTA (K-L 13-14). 

Barnett, V. H. 

Beekly, A. L. 

Darton, N.H. 

Hall, C. M. 

Hayden, F. Y. 

Jaggar, T. A., jr. 

O'Harra, C. C. 

Pishel, M. A. 

Powell, J. W. 

Smith, W. S. T. 

Todd, J. E. 

Vaughan, T. W, 

TENNESSEE (I-J 16--17). 

Campbell, M. R. 

Glenn, L. C. 

Hayes, C. W. 

Keith, Arthur. 

Safford, J. M. 

Ulrich, E. 0. 

Vaughan, T. W. 

Willis, Bailey. 

TEXAS (G-I 13-15). 

Adams, G. I. 

Cummins, W. F. 

Dumble, E. T. 

Deussen, Alexander. 

Gordon, C. H. 

Gould, C. N. 

Hill, B. F. 

Hill, R. T. 

Kay, F. H. 

Paige, Sidney. 

Richardson, G. R 

Spencer, A. C. 

Udden, J. A. 

Vaughan, T. W. 

UTAH (J~K 12). 

Boutwell, J. M. 

Butler, B. S. 

Campbell, M. R. 

Dutton, C. E. 

Eldridge, G. H. 

Emmons, S. F. 

Gale, H. S. 

Gilbert, G. K. 

Goldthwait, J. W. 

Harder, E. C. 

Hayden, F. V. 

Huntington, Ellsworth. 

Keith, Arthur. 

King, Clarence. 

Leith, C. K. 

Powell, J. W. 

Richards, R. W. 

Richardson, G. B. 

Smith, G. 0. 

Spurr, J. E. 

Taff, J. A. 

Tower, G. W. 

Weeks, F. B. 

Wheeler, G. M. 

Willis, Bailey. 

VERMONT (K-L 18-19). 

Bastin, E. S. 

Dale, T. N. 

Hitchcock, C. H. 

Keith, Arthur. 

Smith, G. 0. 

VIRGINIA (J 17-18), 

Berry, E. W. 

Bibbins, A. B. 

Campbell, H. D. 

VIRGINIA (J 17-18)-Continued. 

Campbell, M. R. 

Clark, W. B. 

Darton, N. H. 

Gardner, J. A. 

Geiger, H. R. 

Keith, Arthur. 

Miller, B. L. 

Rogers, W. B. 

Russell, I. C. 

Shaler, N. S. 

Shattuck, G. B. 

Watson, T. L. 

Woodworth, J. B. 

WASHINGTON (L-M 10-11). 

Arnold, Ralph. 

Becker, G. F. 

Calkins, F. C. 

Merriam, J. C. 

Reagan, A. B. 

Russell, I. C. 

Smith, G. 0. 

Willis, Bailey. 

WEST VIRGINIA (J 17). 

Ashley, G. H. 

Brooks, A. H. 

Campbell, M. R. 

Darton, N. H. 

Keith, Arthur . 

Martin, G. C. 

Phalen, W. C. 

Rogers, W. B. 

Stose, G. W. 

Swartz, C. K. 

Taff, J. A. 

White, I. C. 

Willis, Bailey. 

WISCONSIN (K-L 16--16). 

Alden, W. C. 

Bain, H. F. 

Burchard, E. F. 

Chamberlin, T. C. 

Grant, U.S. 

Leith, C. K. 

VanHise, C. R. 

WYOMING (K-L 12-13). 

Ball, M. W. 

Blackwelder, Eliot. 

Campbell, M. R. 

Darton, N. H. 

Eldridge, G. H. 

Fisher, C. A. 

Gale, H. S. 

Hague, Arnold. 

Hayden, F. V. 

Iddings, J. P. 

King, Clarence. 

Lupton, C. T. 

O'Harra, C. C. 

59 
60 INDEX TO THE STRATIGRAPHY OF NORTH .AMERICA. 

UNITED STATES EXCEPT ALASKA-continued. 

WYOMING (K-L 12-13)-Continued. 

Powell, J. W. 

Richards, R. W. 

Schultz, A. R. 

Shaw, E. W. 

Siebenthal, C. E. 

Smith, E. E. 

WYOMING (K-L 12-13)-Continued. 

Smith, W. S. T. 

Spencer, A. C. 

Stebinger, Eugene. 

Taff,J.A. 

Veatch, A. C. 

Washburne, C. W. 

WYOMING (K-L 12-13)-Continued. 

Weed, W. H. 

Wegemann, C. H. 

Willis, Bailey. 

Winchester, D. E. 

Woodruff, E. G. 

DOMINION OF CANADA, LABRADOR, AND NEWFOUNDLAND. 

ALBERTA (1\11-0 11-12). 

Bell, Robert. 

Cairnes, D. D. 

Dawson, G. M. 

Dowling, D. B. 

Leach, W. W. 

McConnell, R. G. 

McEvoy, James. 

Macoun, John. 

Malloch, G. S. 

Selwyn, A. R. C. 

Tyrrell, J. B. 

BRITISH COLUMBIA (M-0 S-11). 

Bancroft, J. A. 

Bauerman, H. 

Bowman, Amos. 

Brock, R. W. 

Cairnes, D. D. 

Camsell, Charles. 

Clapp, C. H. 

Daly, R. A. 

Dawson, G. M. 

Dowling, D. B. 

Ells, R. W. 

Graham, R. P. D. 

Gwillim, J. C. 

Haycock, Ernest. 

Johnston, R. A. A. 

Leach, W. W. 

Leroy, 0. E. 

McConnell, R. G. 

McEvoy, James. 

Poole, H. S. 

Richardson, James. 

Selwyn, A. R. C. 

Webster, Arthur. 

Wright, F. E. 

CANADA (GENERAL). 

Bell, Robert. 

Brock, R. W. 

Dawson, G. M. 

Logan, W. E. 

Selwyn, A. R. C. 

FRANKLIN AND ARCTIC ARCHIPELAGO (P-U 10-20). 

Bell, Robert. 

Low, A. P. 

LABRADOR (N-O 20-21). 

Bell, Robert. 

Low, A. P. 

MANITOBA (M-N 14-15). 

Bell, Robert. 

Dowling, D. B. 

Lawson, A. C. 

Selwyn, A. R. C. 

Spencer, J. W. 

Tyrrell, J. B. 

NEW BRUNSWICK (L 19-20). 

Bailey, L. W. 

Ells, R. W. 

Johnston, R. A. A. 

Mcinnes, William. 

Matthew, G. F. 

Parks, W. A. 

Poole, H. S. 

Rob b, Charles. 

Young, G. A. 

NEWFOUNDLAND (L-M 21-22). 

Bell, Robert. 

Howley, James P. 

Murray, Alexander. 

NORTHWEST TERRITORIES 

(1\11-R 8-21). 

Bell, J. M. 

Bell, Robert. 

Camsell, Charles. 

Dawson, G. M. 

Dobbs, W. S. 

Dowling, D. B. 

Keele, Joseph. 

Low, A. P. 

McConnell, R. G. 

Mcinnes, William. 

O'Sullivan, Owen. 

Tyrrell, J. B. 

NOVA SCOTIA (K-L 19-20). 

Bailey, L. W. 

Barlow, S. 

Ells, R. W. 

Faribault, E. R. 

Fletcher, Hugh. 

Hartley, Edward. 

Logan, W. E. 

NOVA SCOTIA (K-L 19-20)-Contimrod 

McOuat, Walter. 

Matthew, G. F. 

Richardson, James. 

Robb, Charles. 

Selwyn, A. R. C. 

ONTARIO (K-N 11>-18). 

Adams, F. D. 

Ami,H.M. 

Barlow, A. E. 

Bell, Robert. 

Camsell, Charles. 

Collins, W. H. 

Denis, Theodore. 

Dowling, D. B. 

Ells, R. W. 

Ingall, E. D. 

Johnston, J. F. E. 

Johnston, W. fL. 

Lawson, A. C. 

Logan, W. E. 

Macfarlane, Thomas. 

Mcinnes, William. 

Merritt, W. M. 

Murray, Alexander. 

O'Sullivan, Owen. 

Parks, W. A. 

Selwyn, A. R. C. 

Smith, W. H. C. 

Vennor, H. G. 

Walker, T. L. 

Wilson, A. W. G. 

Wilson, W. J. 

Young, G. A. 

QUEBEC (L-N 17-21). 

Adams, F. D. 

Ami, H. M. 

Bailey, L. W. 

Barlow, A. E. 

Bell, Robert. 

Clarke, J. M. 

Dresser, J. A. 

Ells, R. W. 

Haycock, Ernest. 

Johnston, J. F. E. 

Laflamme, J. C. K. 

LeRoy, 0. E. 

Logan, W. E. 
CONTRIBUTORS. 61 

DOMINION OF CANADA, LABRADOR, AND NEWFOUNDJ"AND-contmued. 

QUEBEC (L-N 17-21)-Continued. 

Low, A. P.. 

Mcinnes, William. 

McOuat, Walter. 

Murray, Alexander. 

Osann, A. 

O'Sullivan, Owen. 

Richardson, James. 

Selwyn, A. R. C. 

Torrance, J. F. 

Vennor, H. G. 

QUEBEC (L-N 17-21)-Continned. 

Wilson, M. E. 

Wilson, W. J. 

Young, G. A. 

SASKATCHEWAN (M-0 12--13). 

Bell, Robert. 

Dawson, G. M. 

Dowling, D. B. 

McConnell, R. G. 

Mcinnes, William. 

ALASKA. 

SASKATCHEWAN (M-0 12-13)-Contd. 

Selwyn, A. R. C. 

Tyrrell, J. B. 

YUKON (0-R 7-10). 

Camsell, Charles. 

Dawson, G. M. 

Keele, Joseph. 

McConnell, R. G. 

Tyrrell, J. B. 

[In terms of coordinate letters and numbers, arranged from south to north and west.] 

N-O 8-9, SOUTHEASTERN ALASKA. 

Brooks, A. H. 

Knopf, Adolph. 

Spencer, A. C. 

Wright, C. W. 

Wright, F. E. 

07, YAKUTATBAYANDALSEKRIVER 

REGION. 

Blackwelder, Eliot. 

Russell, I. C. 

Tarr, R. S. 

P 6, CONTROLLER BAY REGION. 

Maddren, A. G. 

Martin, G. C. P 6, LOWER COPPER RIVER. 

Schrader, A. C. 

Spencer, A. C. 

P 6, PRINCE WILLIAM SOUND. 

Grant, U.S. 

Higgins, D. F. 

Schrader, F. C. 

Spencer, A. C. 

P 6-7, CHITINA VALLEY. 

Maddren, A. G. 

Mendenhall, W. C. 

Moffit, F. H. 

Schrader, F. C. 

Spencer, A. C. 

P 7, UPPER TANANA AND WHITE 

RIVER BASINS. 

Brooks, A. H. 

Knopf, Adolph. 

Moffit, F. H. 

Schrader, F. C. 

P 6, UPPER COPPER RIVER REGION. 

Mendenhall, W. C. 

Schrader, F. C. 

0-P 5-6, EASTERN HALF KENAI 

PENINSULA. 

Grant, U.S. 

Higgins, D. F. 

Moffit, F. H. 

0 6, KACHEMAK BAY REGION, 

Martin, G. C. 

Stanton, T. W. 

Stone, R. W. 

0 5, KODIAK ISLAND. 

Becker, G. F. 

Dall, W. H. 

N 3-4, 0 4-5, ALASKA PENINSULA. 

Atwood, W. W. 

Martin, G. C. 

Spurr, J. E. 

Stanton, T. W. 

0 4-5, P 5, ILIAMNA AND LAKE CLARK 

REGION. 

Katz, F. J. 

Martin, G. C. 

P 6, MATANUSKA VALLEY. 

Knopf, Adolph. 

Martin, G. C. 

Paige, Sidney. 

P 5, SUSl'l'NA BASIN. 

Brooks, A. H. 

Eldridge, G. H. 

Spurr, J. E. 

P 5-6, ALASKA RANGE. 

Brooks, A. H. 

Prindle, L. M. 

Q 5-7, YUKON-TANANA REGION. 

Brooks, A. H. 

Prindle, L. M. 

Spurr, J. E. 

Q 7, PORCUPINE RIVER. 

Kindle, E. M. 

Maddren, A. G. 

Q 6, CHANDALAR AND UPPER 

KOYUKUK. 

Maddren, A. G. 

Mendenhall, W. C. 

Schrader, F. C. 

P 4, Q 4-5, YUKON VALLEY. 

Collier, A. J. 

0-P 4, KUSKOKWIM VALLEY AND 

BRISTOL BAY REGION. 

Spurr, J. E. 

P 4, INNOKO REGION. 

Maddren, A. G. 

Q 4, YUKON RIVER AND NORTON 

BAY REGIONS. 

Eakin, H. M. 

Smith, P. S. 

Q 4, KOBUK VALLEY. 

Mendenhall, W. C. 

Q-R 5, ENDICOTT RANGE AND ANAKTUVUK AND COLVILLE RIVER 

VALLEYS. 

Schrader, F. C. 

Q 3, SEWARD PENINSULA. 

Brooks, A. H. 

Collier, A. J. 

Moffit, F. H. 

Smith, P. S. 

R 3, CAPE LISBURNE REGION. 

Collier, A. J. 

Kindle, E. M. 

P 3, NUNIVAK ISLAND. 

Dall, W. H. 

Dawson, G. M. 

P 2, ST. LAWRENCE ISLAND 

Collier, A. J. 

GREENLAND AND ICELAND (P-U 1 9-28). 

Garde, Victor. 

Hammer, R. R. I. 

Holm, G. F. 

Jessen, A. 

Kornerup, A. 

Low, A. P. 

Nathorst, A. G. 

Nordenskjiild, Otto. 

Steenstrup, K. J. V. 

Thoroddsen, Th. 
CHAP'rER II. 

PRE-CAThiBRIAN. 

The pre-Cambrian of North America has been described in detail and with 

exhaustive consideration of the literature in the revised correlation bulletin on the 

pre-Cambrian by Van IIise and Leith.828 That work makes any description of the 

terranes superfluous in this paper, which will confine itself to a list of the areas colored 

as pre-Cambrian (see fig. 3) and an account of the efforts made to reach a satisfactory 

classification for the purposes of the geologic map of North America. 

Pre-Garnbrian areas. 

Keewatin (23a).a 

L-M 15-16 .................... Minnesota, Wisconsin, Michigan, Ontario. 

"Laurentian" (23). 

L 14-16 ....................... Wisconsin, Michigan, Minnesota, and North Dakota (undifferentiated pre-Cambrian, 

which is mapped with "Laurentian"). 

L 19-20 ....................... New Brunswick, Nova Scotia. 

L-M 21-22 .................... Newfoundland. 

L 17-18, M 14-21, N 13-21,} ,, d' h' ld O · Q b M · b s k h Alb N h T · 0 12_

20 p 11_20 Q 9

_

20 Uana_ mn s 1e : ntarw, ue ec, an1to a, as ate ewan, erta, ort west ern-

' ' ' tones. R 8-19 ................... .. 

S 14-18, T 17-19, U 17-lS ....... Arctic Archipelago. 

p 22- 23, Q 22' R 22' S 21'lWest coast of Greenland. 

T 19-20 ................... . f 

p ~~~ ~: .. ~. ~~:. -~~~-. ~_ ::}East coast of Greenland. 

Laurentian (23d). 

L-M 15-16 .................... Minnesota, Wisconsin, Michigan. 

Earlier(?) pre-Cambrian unclassified (22). 

L 12 .......................... Montana (Cherry Creek group, early Algonkian; mapped with Belt series, 2la, late 

Algonkian). 

L-N 17-18 .............. _ ...... Ontario, Quebec. 

M-N 15-16 .. _. __ .... __ . ___ ._ .. Ontario, Northwest Territories. 

M 21. .............. _ . __ ........ Newfoundland. 

N 13-14 ......... __ .... _______ .Saskatchewan, Northwest Territories. 

N 19-20 ....... _____________ ... Quebec, Northwest Territories. 

0 12 ............. ____ .......... Saskatchewan. 

0 20 .............. _ .. _. _ ....... Labrador. 

P 12-15, Q ll .................. Northwest Territories. 

T 19 ................. ____ ..... Greenland. 

a Numbers in parentheses refer to numbers of corresponding color blocks on the map. 

62 
FIGURE 3.-Sketch map showing the distribution of pre-Cambrian rocks represented on the geologic map of North 

America and the key to references in the text. The large area covering northern Canada is shown by line pattern, 

smaller areas by solid black. 

63 
64 INDEX TO THE STRATIGRAPHY OF NOR'l'H AMERICA. 

Hastings and Grenville (22a). 

L 17-18 ....................... Ontario and Quebec. 

Middle and Lower Huronian (22b). 

K 14-15 ........................ South Dakota, Minnesota. 

L-M 15-16 .................... Wisconsin, Michigan, Ontario. 

I, 17 .......................... Ontario. 

Late (?) pre-Cambrian unclassified (21). 

J 13 ............................ Colorado (Needle Mountains group; mapped with Belt series, 21a). 

K 12 ........................... Utah, Colorado (quartzites of Uinta and Wasatch mountains; mapped with Belt series, 

21a). 

K-L 19-20 .................... Nova Scotia. 

M 18 ........................... Quebec. 

L-M 21-22 .................... Newfoundland. 

N-P 18-19, N 20-21. ........... Quebec, Northwest Territories. 

0 15 ........................... Northwest Territories. 

0-Q 12-13 ..................... Alberta, Saskatchewan, Northwest Territories. 

P-Q 14, Q-R 10-13 ............ Northwest Territories. 

Upper Huronian (2lc). 

L-M 15-16 .................... Minnesota, Wisconsin, Michigan, Ontario. 

Keweenawan (2lb). 

L 15-16 ....................... Minnesota, WiRconsin, Michigan. 

M 16 ........................... Ontario. 

Belt series (2la). 

J 13 ................. _ .......... Colorado (Needle Mountains group, which is included with Belt series of map). 

K 12 ........................... Utah, Colorado (late Algonkian, which is included with Belt series on map). 

L-M 11-12 ................... Idaho, Montana, British Columbia, Alberta. In Montana the Cherry Creek group 

(early Algonkian) is mapped with the Belt series (late Algonkian). 

Undifferentiated pre-Cambrian (23b). 

H 13-14 ........................ Texas. 

I 11-13 ......................... California, Arizona, New Mexico. 

I 16-18 ......................... Alabama, Georgia, North Carolina, South Carolina. 

J 13 ............................ Colorado. 

J 15 ............................ Missouri. 

J 17-18 ......................... North Carolina, Virginia, Maryland, Delaware, Pennsylvania, New Jersey. 

K 12-13 ........................ Utah, Wyoming, Colorado. 

K-L 18-19 .................... Pennsylvania, New Jersey, New York, Connecticut, Massachusetts, Rhode Island. 

L 11-13 ....................... Idaho, Wyoming, Montana. 

L-M 14-16 .................... Wisconsin, Michigan, Minnesota, North Dakota (mapped with "Laurentian"). 

Gneisses, schists, and metamorphosed sediments (23c). (Supposed pre-Cambrian, possibly in part Paleozoic and 

:Mesozoic). 

B 17-20 ........................ Panama, Colombia, Venezuela. 

C 19-20 ........................ Venezuela. 

D 14-16 ....................... Mexico, Guatemala, Hondurao, Nicaragua. 

E 13-16 ........................ Mexico, British Honduras. 

F 13-14, G 13 ................. Mexico. 

J 11 ............................ Nevada. 

K 10-11. ....................... Oregon, California, Nevada. 

L 11. ......................... Washington, Idaho. 

M-N 10-11. ................... British Columbia, Washington. 

0 9-10 ......................... British Columbia. 

P-Q 4-8 ........................ Alaska, Yukon. 

Q 3 ............................ Seward Peninsulil, Alaska. 
PRE-CAMBRIAN. 65 

Pre-Cambrian intrusive rocks (24). 

I 14 ............................ Oklahoma. 

I 16-17 ...... _ .......... __ . _ . __ . Georgia, North Carolina, South Carolina. 

J 17-18 ....................... _.North Carolina, Virginia, Maryland, Delaware, Pennsylvania. 

K 18 ................. _. _ ....... Pennsylvania, New York. 

L 17-19 ....... _. _ ....... _ ..... Ontario, Quebec. 

M 1.5 ....................... _ ... Ontario. 

M 18-20 ........................ Quebec. 

N 20--21. .................. _ ... Quebec, Northwest Territories. 

N-0 17-18, P 17-19 ............ Northwest Territories. 

0-P 22-24 ................ _ ..... Southern Greenland. 

R 22 .......................... West coast of Greenland. 

PRE-CAMBRIAN CLASSIFICATION. 

The problem of pre-Cambrian classification has been difficult of adjustment 

under the requirements of the map of North America. The Canadian Survey adheres 

to its long-established divisions Laurentian and Huronian, which rest upon the work 

of Logan and his successors. The modifications developed by modern studies have 

not in the opinion of Canadian authorities rendered these terms less useful or justified substitutes or material changes of definition. The United States Survey adopted 

the divisions Archean and Algonkian in 1889 and they have been earnestly advocated 

by the geologists working in the Lake Superior region in their earlier as well as in 

their latest publications. These geologists maintain that the terms Archean and 

Algonkian stand for two great major divisions which constitute a "dual classification" of the pre-Cambrian that is thought probably to be of general occurrence and 

to distinguish two grand eras or' the earth's history. The points of view of the 

Canadian and United States geologists have been presented by F. D. Adams 1

•

2 and 

C. R. Van Rise 826' 827 and are also set forth in the report of the special (international) 

committee for the Lake Superior region. 3 

The classification of the pre-Cambrian which the compiler introduced in the 

map of 1906 was the result of an attempt to adjust differences of interpretation to 

the requirements of a general map, in which the number of distinctions was limited. 

In conformity with the terminology of the international congress the prefixes neo 

and eo were used for two major divisions of the post-Archean, both of which, according to the nomenclature employed by the United States Geological Survey, belonged 

to the Algonkian. Thus arose neo-Algonkian and eo-Algonkian. The classification 

could not, however, be carried through with perfect separation of the several systems-Archean, eo-Algonkian, and neo-Algonkian-and it became necessary to state 

that each of these systems as represented on the map of 1906 might include masses 

belonging to one of the other two. The wording of the explanation in the legend 

of the map did not make it plain that the Keewatin was included under eo-Algonkian, 

for instance, only because of the requirements of cartography and in spite of the 

well-known fact that the two are separated by a great unconformity, and the classification was therefore criticized by American as well as by Canadian geologists. The 

latter objected to the term Algonkian; the former objected to the confusion of 

distinct systems in one. 

48011°-12-5 
66 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

These objections were entirely just from the point of view of the systematic 

geologist. The Keewatin does not belong to the Algonkian and is separated from 

the lowest terrane of that system by an unconformity which is regarded as equivalent to a long interval of time. But this interval and the distinction between these 

terranes can not be expressed on the map so long as it is true, as stated by Dr. Adams, 

that "It is impossible for us as yet to separate the Keewatin from the Huronian, 

these two divisions having been, up to the present time, both classed as Huronian." 

The legend of the map of 1906 does not, however, adequately express the fact that 

the mapping is less advanced than investigation. It should have stated plainly that 

eo-Algonkian comprised Lower and Middle Huronian, and that the areas so mapped 

included some undifferentiated Keewatin which belongs to the Archean. 

In preparing the revised edition of the geologic map of North America) effective 

agreement on problems of classification and nomenclature was sought by the officers 

of the United States Survey. An international committee, composed of geologists 

representing the surveys of Canada and the United States, had brought about an 

understanding in regard to questions relating to the geology of the Lake Superior 

region and to that of eastern Canada and New York. At a meeting of that committee inN ew York on December 29, 1906, it was voted that a subcommittee consisting 

of three representatives from Canada and three from the United States be appointed 

to consider questions of classification and nomenclature in connection with the 

preparation of a geologic map of North America by the United States Geological 

Survey. Bailey Willis was designated chairman of this subcommittee, the other 

members to be selected later by correspondence between Messrs. Low and Hayes. 

The subcommittee thus nominated consisted of F. D. Adams, R. A. Daly, and James 

White, representing the Canadian Survey, and T. C. Chamberlin, C. R. VanHise, 

and Bailey Willis (chairman), for the United States Survey. A meeting was held 

at Toronto March 7, 1907, and the entire scheme of nomenclature for the map was 

considered from Quaternary to pre-Cambrian. The following classification of the 

older rocks was agreed to: 

Paleozoic _____ . _______ . __ .. _ . _______ .. Cambrian and latest pre-Cambrian. 

p t . {Later Proterozoic, including unseparated earlier Proterozoic. ro erozmc-------------- ·------- · · · ·- Earlier Proterozoic, including unseparated later Proterozoic. 

Ancient schists and igneous rocks. 

Laurentian gneiss. 

The action of the committee was a compromise which was designed to meet the 

needs of a legend for the general map but which did not go beyond that point in 

attempting to adjust existing differences of opinion. Prof. Van Hise dissented from 

the proposed division of the Proterozoic. The subcommittee did not indicate any 

areas to be mapped under any particula,r designation, that selection being left to 

the compiler, Mr. Willis. _ 

From studies which followed the meeting nt Toronto, the compiler concluded 

that a map prepared on the compromise there reached would not adequately present 

the known facts or express the existing uncertainties regarding the pre-Cambrian 

sequence and classification. At his instance a further conference was proposed and 

held at Chicago, February 21, 1908. The conferees were R. W. Brock, Acting 

Director, and F. D. Adams, for the Can;:tdian Survey; W. G. Miller, for the Ontario 
PRE-CAi\iBRIAN. 67 

Bureau of Mines; and T. C. Chamberlin, C. R. Van Rise, and Bailey Willis (chairman), for the United States Survey. The discussion of the problem of pre-Cambrian 

classification was earnest and prolonged. It clearly developed the fact that knowledge of the pre-Cambrian terranes is not yet adequate to furnish criteria by which 

even some of the major divisions may be surely correlated or to offset the differences 

of opinion which spring from historical associations or personal experience. The 

.discussion was in part as follows: 

Mr. Willis presented as a basis for discussion a tentative classification of the 

pre-Cambrian, which is shown in figure 4 by the names printed in Roman type. It 

embodied Archeozoic and Proterozoic without definite delimitation; undifferen1~ r 

.Sl 

I I ~ £ 

0 .§ Akn -7J s::l» 

"' "'"' Keweenawan Belt and allied ~ ·.:~ 

"" ~ "¢ ..0 s:: 

~ terranes ~ ..., c "' s"' ~ s:: ·.;:; .s ~~ G .~ "' s:: c .8 I :-;::::::, 

"' ~ s:: .tJ ,_ ·.: 8 "'"" <l) Ul ~ 

s:: <( ... ~ d:: ~ i5 c 

-~ .0 <l) I 

~ ~ [0 § 0 0 !:><) !1.:: Upper Huronian .... I " Ul "' ., < "" 0 I til <l)~ 0 u· s:: ·.: I "' ~ ... .=:::~ d, p $ 

~ <l) 

·~ "'" ... "' "" 2·- E "" § ;:l ""' ~ ....,<.> 

p... t/1 ~ s::·- (.) "" 0 <l) "' .., ·- ~ 

~ '1iddle and Lower Cl '" Q._ ..,., I),. .;:~ ~ -oo ..... Huronian ..s S::Ul 0 u <1 "g s::' "'"' ,_ Ul::g 

I <l) "' Q._ c.. "' 1E» ~· <l) Hastings ~~ 0 I -5 G :.c:o !1.:: and i@§ Jl"fR I "" ... Grenville ""u I s:: «: -c;o p I Keewatin ~'"0 "'"" 

I s:: I ~ @: 

I "' I 

d0 <l) 9/ I "' CJ.S:!:' 

I ~ B s:: 0· 

Erll!lti •e eentaet I .;:I Pg. .~ I «: I ~ OJ A<i "' ~ ~ I 

,_ p..,. 

Laurentian ;il 

-5 "' ... '-1 

«: 

FIGURE 4.-Classification of the pre-Cambrian adopted by the international committee. The portion in roman type 

represents the table as originally presented by Mr. Willis. The corrections made by the committee are shown, the 

additions being in italics. 

tiated pre-Cambrian, which was also designated Laurentian of Canada in general 

and Archean of Dana; Archean and Algonkian of the United States Geological 

Survey; the classification adopted by the international committee for the Lake 

Superior district; the Hastings and Grenville series of eastern Canada; the Belt 

series and allied terranes; and the unclassified schists and intrusives of the Cordillera. 

Pnf. Van Rise took up the discussion and emphasized the point that it is 

desirable in such a map as that under discussion to make clear the relation of the 

adopted color scheme to the various classifications in use by different organizations 

and in different textbooks, in order that the matter might be plainly understood. 

Prof. Adams, speaking for the Canadian geologists, stated that if the requirements of cartography limited the classification to three divisions, they would wish 

one to indicate Laurentian and two others to represent two different parts of the 

Proterozoic. The divisions of the Proterozoic have to be made on grounds which 

seem valid now, but they may have to be shifted as the work goes on. The map 

represents the distinctions essentially as the Canadian geologists would like to 

have them made, even though in the course of eight or ten years the colors will 

have to be revised. Some great areas that are little metamorphosed lie in the. 
68 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

neighborhood of areas that are highly metamorphosed, and it may be that those 

which are considered older may prove to be newer, but as we have no very definite 

line to divide newer from older, the Canadian Geological Survey would undertake 

to state how the distinctions should be made. 

Mr. Willis called attention to the classification of the Paleozoic into metamorphic and nonmetamorphic and suggested that the same distinction might be applied 

to the Proterozoic of the northern shield. · 

After some discussion, in which Prof. Chamberlin urged that metamorphism 

was but one factor in discriminating older and newer Proterozoic and that the 

classification should be based on several factors, Prof. Adams stated that throughout 

northern Canada there are patches of rock that resemble very closely the Keweenawan. There is a very strong presumption, which Dr. George Dawson believed, 

that it is the most extensive of the Proterozoic formations of North America. In 

other places occur formations which resemble Huronian. There is a distinction of 

metamorphism which is also very largely a distinction of age. 

The discussion also brought out the fact that in the region northwest of Hudson 

Bay the Keweenawan facies is predominant; whereas in the Labrador Peninsula, 

east of Hudson Bay, the resemblances to the Animikie appear to be closer. It 

appeared therefore that a classification into older and newer Proterozoic must be 

one which separates the Animikie and Keweenawan from the Huronian. 

As a result of the discussion it was agreed that the Canadian Geological Survey 

should be responsible for the classification of the Proterozoic in two gro\1-ps which 

should in a general way express a relation of older formations to younger ones but 

which should be clearly explained to be somewhat indefinite and subject to future 

rev1s10n. 

The use of the term Laurentian in general was then considered at length. By 

reference to figure 4 it will be seen that four different interpretations were represented in the committee. The most comprehensive allied Laurentian in general 

with the Archean of Dana, Laurentian in general being understood to mean the 

pre-Cambrian rocks of the great northern shield, regarding which it is not definitely 

known whether they are prevailingly pre-Huronian or include also large areas of 

Huronian. The second interpretation of the Laurentian in general is that which 

relates it to the Archean according to the restricted definition comprising Keewatin 

and intrusives into the Keewatin-that is, the pre-Huronian formations to which 

Logan originally gave the name Laurentian. The third interpretation is that 

which is represented in the Canadian classification (italics in fig. 4) and which is 

closely related to the second but leaves the upper limit of the Laurentian in general 

somewhat indefinite, it being recognized that throughout the Canadian shield there 

are many intrusives whose age can never be precisely determined on account of the 

absence of overlying sedimentary rocks. The fourth interpretation is the restricted 

Laurentian of the international committee on the Lake Superior and Adirondack 

regions, which limits the term to acidic rocks intrusive into the Keewatin, except as 

it may be employed, "preferably with an explanatory phrase," to designate some 

"associated granites of large extent which cut the Huronian or whose relations to 

the Huronian can not be determined." 
PRE-CAMBRIAN. 69 

The first interpretation (Laurentian in general considered as the equivalent of 

undifferentiated pre-Cambrian) ,·was found to be unacceptable to the Canadian representatives. Prof. Adams had earlier in the discussion expressed the opinion that 

the Laurentian in the sense of pre-Huronian constituted essentially 99 per cent of 

the northern part of the Canadian shield. 

In answer to a question by Mr. Willis as to whether the Canadians were prepared 

to restrict Laurentian to the equivalent of pre-Huronian, Dr. Brock responded: 

I think we were all agreed at Ottawa that this would be the most desirable thing to do if 

possible, but we overruled it on account of the difficulty in separating the Keewatin and Huronian. It was necessary to have some color which would indicate Keewatin and I,ower Huronian 

for purposes of mapping. Economically they go together. If we could possibly do it we would 

very much prefer to have a general color to cover the lower part, but in mapping I do not think 

we can do it. We have many areas in which we can not differentiate the Keewatin and Lower 

Huronian. 

Prof. Chamberlin asked: 

What is your preference, Mr. Brock, in regard to the lower formation~ Should it represent 

undifferentiated pre-Cambrian or should it represent Archean~ 

Dr. Brock responded: 

We would prefer to see it represent the Archean. There is, of course, undifferentiated 

Huronian in that probably, but the main fact is that the great part of the northern area represents what Logan called Laurentian. 

Prof. Chamberlin urged the recognition of Logan's definition of Laurentian. 

He said: 

From my point of view I should like to see the general color [adopted for the Canadian 

shi.eld] represent pretty closely Logan's idea, which involves Keewatin, Laurentian intrusive 

into Keewatin, and rocks of general Laurentian aspect-the old gneiss groups as confessedly an 

undifferentiated series but as a great series representing one of the greatest of the eras of the 

earth's history; so that if this conception is' true we have the great nucleus of the continent. 

I am thinking of something more fundamental than pre-Cambrian, something nucleal to 

Huronian, Animikie, and Keweenawan. We need to find the general nucleus from which the 

Canadian formations have been derived. 

Prof. Van Hise granted the fact that the nucleus described had existed for 

Paleozoic formations but did not admit that the Canadian region was a nucleus 

for the pre-Cambrian. 

As a result of further discussion the term Laurentian in general as applied to 

the unclassified pre-Cambrian was stricken out. The use of Laurentian in general 

as equivalent to Archean in the restricted sense of pre-Huronian was recognized 

as one having a theoretical significance, but one which in the present state of knowledge does not represent a mappable thing. There remain the two usages, namely, 

(1) Laurentian equivalent to the Keewatin and the intrusive rocks cutting the 

Keewatin and including probably some Huronian a and (2) the Laurentian intrua In commenting on these minutes of the conference, Prof. Adams, under date of March 9, 1908, wrote: "In this 

usage the Laurentian includes not0nly rocks which are equivalent to Keewatin but any portion of the pre taxis which 

may be found to be older than keewatin; that is to say, if in the great northern pro taxis the base e:x:iRts on which the 

Keewatin has been deposited, this also is of Laurentian age. It may easily be that a not inconsiderable proportion 

of the Laurentian protaxis is really pre-Keewatin in date." 
70 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

sive in the Keewatin, which is restricted, in mapping at least, to areas that have 

been surveyed in detail. It was determined to recognize both of these divisions 

of the Laurentian to the extent that present knowledge justifies such distinction. 

The arrangement of the classifications agreed upon was then taken under 

consideration and the schedule was corrected as shown in figure 4. The revised 

classification showing the various usages which are there set forth was then unanimously adopted on motion of Prof. Chamberlin, seconded by Prof. Adams. 

The classification thus drawn up comprises the usage accepted for this publication by the Canadian Survey and the United States Survey, also the local 

sequence of eastern Canada, of the Lake Superior region, and of the Cordillera. 

It presents the presumed correlation of these various classes according to present 

knowledge and fixes the responsibility for the mapping of different sections upon that 

organization which has done most of the work in either district. 

I 16-17, J 17-18. SOUTHERN APPALACHIAN MOUNTAINS. 

The revision of the pre-Cambrian rocks of the Appalachian Mountains by 

Arthur Keith and the sources of information used by him are stated in the following 

memorandum, which he prepared for this work. 

The geologic formations of the area between the Blue Ridge and the Coastal Plain and 

from Maryland to Alabama have been revised from those shown in published maps, according 

to detailed and reconnaissance work that I have done during the last 20 years. 

In Virginia the boundary at the base of the Cambrian near the Blue Ridge and all boundaries east of that, except for the Richmond and the Danville Triassic basins, are new. They 

are based on detailed work as far south as latitude 38° 30'; south of that latitude they are 

:founded upon reconnaissance work. 

In North Carolina the detailed geology of the published folios for the western part of the 

State is supplemented by reconnaissance in the central part of the State; for the eastern part 

of the crystalline rocks, the mapping is based on the old map of North Carolina by W. C. Kerr, 

with some modification and reinterpretation of the areas. 

In the western part of the State also the detailed but yet unpublished work extends from 

the mountains and the Blue Ridge 20 to 40 miles into the Piedmont Plateau. 

In South Carolina the northwestern margin of the State has been mapped in detail and a 

detailed survey has been made of the Kings Mountain region in northern-central South Carolina and in North C~rolina. The remainder of the mapping in the State is based on the old 

county maps of Lieber, somewhat modified by my reconnaissance. 

For Georgia manuscript maps of C. W. Hayes have been used west of longitude 84 ° 30' 

and north of 33° 30'. My detailed and reconnaissance work affords the basis for mapping 

formations north and northeast of Atlanta, including the belt of probable Cambrian strata 

(Brevard schist). Southeast and south of that line I have used the map of the granites of 

Georgia published by T. L. Watson, with slight modifications. 

In the rocks southeast of the main Cambrian belt three divisions are made-(1) Paleozoic 

igneous rocks of post-Cambrian age; (2) undivided pre-Cambrian gneisses and schists; and (3) 

pre-Cambrian igneous rocks, mainly granites and granitoid rocks. Of the pre-Cambrian igneous 

rocks, only the granites are mapped in class 3, the Roan gneiss being omitted, although mainly 

igneous, because most of its areas are too small to show with the present map scale. The 

effusive pre-Cambrian igneous rocks are included with the granites in the mapping, as no 

provision is made in the color scheme to separate them. 

Although most of the boundaries shown are those between different pre-Cambrian formations, considerable areas of Paleozoic intrusive rocks are distinguished, especially in Georgia and 

the Carolinas. In the areas so shown there are known to be minor areas of pre-Cambrian rocks, 

• 
PRE-CAMBRIAN. 71 

mainly granites, and similarly there are Paleozoic granites in the areas shown as pre-Cambrian. 

Separation of these minor areas is difficult, even with detailed work, and i§ not warranted by 

the present state of our knowledge. It is believed, however, that the present mapping is sufficiently accurate to give a fair idea of the distribution of the various igneous and metamorphic 

rocks of the Piedmont-a matter which has not previously been attempted. The divisions 

used consist of groupings of formations that have been distinguished in the detailed work in 

the Appalachian Mountains. I have described these in full in folios of the United States Geological Survey and my summary of them is given in Survey Bulletin 360 ("Pre-Cambrian geology 

of North America," by Van Rise and Leith), page 701. 
Color, purplish red. 

Symbol, 18. 

CHAPTEH III. 

CAMBRIAN AND LOWER ORDOVICIAN. 

Distribution: General throughout the continent. (See fig. 5.) 

Content: In general comprises Lower Cambrian (Georgian) to Lower Ordovician (Beekmantown), inclusive, or so much as may be present; in the Appalachian zone, Virginia to 

Alabama, includes conformable formations below the Olenellus horizon; Ocoee group and 

other terranes; Brevard, W everton, Harpers, and others not named. In the Cordillera 

includes upper Ordovician and Silurian where they are present and the bands of color 

are too narrow for distinct mapping. 

Cambrian and lower Ordovician areas. 

Page. 

H 12 .......................... Bisbee district, Arizona ............................ _. __ .. _ .. _. _________ ._. 72 

H 13. ______ . ___ . _. __ . _ .... ____ Trans-Pecos Texas .... ___ . ____ ._. __ ... _._. __ .... ____ .. _._. _____ . __ ... ___ ._ 75 

H 14 .... __ ..... _ ........... _ .. Llano district, Texas ...... _............................................... 77 

I 12. _ .... _ ...... _ ........... _.Arizona.................................................................. 81 

I 13 ... _. ____ ........ _ .. _._. __ .New Mexico (not separately mapped)._ .... __ .... _ .... __ . __ . __ .... _ .. _. __ ._ 81 

I 14-15. ___ . _ .. _ ..... _ ... __ ._ .. Oklahoma .......................................... ___ . __ .. _ ... __ ... ___ .. 82 

I 16. _. ___ .. _. _ ... _____ . __ . ___ .Alabama and Georgia ..... _ .... _ .... __ .. __ ._ .. ___ . __ . __ . ___ .. __ .. _._ ... __ . 84 

I-J 12 .. ___ . __ . __ ... __ . _ .. ___ .. Grand Canyon, Arizona .............. _ ..... _ ... __ .... __ ._ .. __ .. ____ . __ .. __ 88 

I-J 16-17 __ ......... _. _ .... __ .. Tennessee and North Carolina_ .... _. __ ._ ........ __ .. _. ___ . __ . ___ .. ___ ... __ 89 

J 11-12. ____ . __ .... ______ . __ ... California, Nevada, and Utah .... _ ....... _. ____ ....... ___ . __ . _______ . _ _ _ _ _ 98 

J 13 __ ...... _ . ___ ... _ ....... _ .. Colorado ........................................ _ ... _ ..... __ .. _ . _____ . _ _ _ 102 

J 15 __ .. _ ............ ___ .. _ . _ .. Missouri and northern Arkansas ....................... __ ... _ ... __ .. _ .. _ . __ . 103 

J 17-18 ....... _ .... __ . _._._ .... Virginia and Maryland. (See J 17-18, Chapter IV, pp. 173-175.) 

K 12 .... _. _ ..... _ .......... _ .. Idaho and Utah .... _..................................................... 106 

K 18 .... __ ...... _ .. _. _ ..... _ .. Pennsylvania, New Jersey, and slate belt of eastern New York and western 

New England .......................... _ .. _ ................ _ .. ___ . ___ . _ 107 

K 19. ___ ... _ . _ . _ . _ .... _ . __ .... Eastern Massachusetts ......... __ ........... _ .. ___ .. ____ . _ . _ . ____ . _ . ____ . _ _ 114 

K-I, 12-13 ..................... "\Vyoming ................................. __ ......... _ .. _ . __ . __ ... _ . _ . . . 116 

K-L 13. __ . _ ......... ____ ._._._Black Hills, South Dakota ........... _ .... _ .. ____ . _____ .. _ .. _. _. __ . ______ . 118 

K-L 15-16 ......... _ ... __ . _ .... :\iinnesota,"Wisconsin, and Michigan ...... _ .. __ .. _____ .... _ .. ___ ... _._.____ 118 

K-L 18 .. ___ .... _. _ ..... _._._ .. Adirondack region, New York ............ _ .. ___ . ___ .. __ ..... _ .. _. __ ._.____ 120 

L 12. _ ........... _ .... _ ........ Southwestern Montana .......................... _ .. _ ..... _. _ .. __ .. _. _. __ . _ 127 

L 18-19 ............. __ ......... St. Lawrence Valley ................................. __ .... ___ ... _. ___ .. __ 130 

L19 ___________________________ Maine; Carleton and York counties, New Brunswick------------------------ 134 

L 20-22 .......... _. _. ___ . __ . __ .New Brunswick, Cape Breton, and Newfoundland ........ ___ . ________ . ___ . 136 

L-Q 10-21. _ .... __ . _ . ___ . _____ . Canadian shield ............................. _ ...... __ .. _ . ________ . _ _ _ _ _ _ _ 148 

M 19-20 .... _ . __ . _ ..... _ ... ___ . Gaspe Peninsula ................................. _ ..... _ ... __ . ___ . ___ , _ . _ _ 148 

M 21. ... _ ..... _ ..... _. _. ___ ... Northern Newfoundland .................................... _ .. _ .. _ .... __ . 149 

~1-N ll ... __ ..... _ ... __ .... ___ . Rocky Mountains of Canada ............................. __ .. _______ .. ___ . . 154 

Q 3 .. _. _. ____ . _. __________ .. __ Seward Peninsula. (See 0-R 2-8, Chapter YII, pp. 353-354.) 

Q 5-6 ... ___ ... _._ ... ___ ... ___ .Northern Alaska. (See 0-R 2-8, Chapter VII, pp. 353-354.) 

S 27 __ .. __ . ____ . ____ . _. __ . __ ._.Eastern coast of Greenland. (See Chapter IV, p. 224.) 

T 17-18 .. ___ ..... _. ___ . ____ . __ .Ellesmere Land . _ .................................... __ ...... __ ... _...... 155 

H 12. BISBEE DISTRICT, ARIZONA. 

In southeastern Arizona, in the Bisbee district, Ransome 658 distinguishes the 

probable equivalents of the Tonto group as the Bolsa quartzite and Abrigo limestone. He says: 

72 
FIGURE 5.-Sketch map showing the distribution of Cambrian and lower Ordovician rocks represented on the 

geologic map of North America and the key to references in the text. 

73 
74 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The Bolsa quartzite is constant in its lithological character and is readily recognized wherever 

it occurs. The base of the formation is exposed at many places along Escabrosa Ridge. It is invariably marked by a bed of conglomerate from 6 inches to a foot in thickness, resting upon the 

eroded edges of the pre-Cambrian schists. Most of the pebbles of this basal conglomerate are 

composed of white vein quartz and are rarely over 3 inches in diameter. This conglomerate 

is overlain by hard pebbly grits in beds from 10 to 20 feet in thickness, the change from conglomerate to grit being, as a rule, not very definitely marked. The scattered pebbles in these 

thick-bedded grits are usually white quartz, but their matrix frequently contains abundant 

small fragments of pink feldspar mingled with the predominant quartz grains. Cross-bedding 

is often a conspicuous feature in the lower part of the formation. The pebbly grits in turn 

pass upward into thinner bedded, more vitreous, fine-grained quartzites showing no feldspathic 

material, which are conformably overlain by the Abrigo limestone. 

The Bolsa quartzite was deposited during an advance of the sea over a subsiding basement of pre-Cambrian crystalline rocks which had been worn down by long-continued erosion 

to a nearly level plain. The arkose character of some of the lower beds of the quartzite shows 

that this ancient crystalline basement is composed in part of granitic rocks. None of the 

latter, however, are exposed in the Bisbee quadrangle, where fine-grained sericitic schists are 

the only pre-Cambrian rocks known. The basal conglomerate of the Bolsa formation is a littoral deposit made up of the most durable materials of this sch,ist terrane, chiefly fragments 

of quartz derived from the numerous irregular veins that occur within the schists, while the 

finer particles of quartz and flakes of mica were probably transported by currents into deeper 

water and contributed to the formation of the overlying quartzite beds. The general nature 

of the Bolsa formation, particularly the pebbly and cross-bedded character of its lower portion, 

indicate that deposition took place in comparatively shallow water, with probably a gradual 

increase in depth as the upper beds were laid down. The conditions were apparently not 

favorable to marine life, as no organic remains have yet been found in the Bolsa quartzite. 

As no fossils have been found in the Bolsa quartzite its exact geological age is not directly 

determinable. It will presently be shown, however, that the Bolsa formation is conformably 

overlain by the Abrigo limestone which contains a middle Cambrian fauna. It is thus without 

very much doubt, the stratigraphic equivalent of the Tonto sandstone of the Grand Canyon 

section, considered by Walcott as also included within the middle Cambrian, the lower Cambrian being there represented by the unconformity between the Tonto and the Grand Canyon 

series. It is possibly the equivalent of at least the lower part of the thicker and more varied 

Apache group of the Globe district in central Arizona, about 110 miles north-northwest of 

the Bisbee quadrangle, and also correlated provisionally with the Tonto group. * * * 

The Abrigo limestone is named from Abrigo Canyon, 3 miles southwest of Bisbee, where 

the beds composing the formation are well exposed. Like the Bolsa quartzite, the Abrigo 

limestone occurs principally in the northwestern part of the quadrangle, although a few small 

areas are found within the attenuated belt of Paleozoic rocks extending southeastward past 

Gold Hill toward Glance Creek. The most satisfactory occurrence, and the only one in the 

quadrangle where the entire sequence of the beds from base to top may be studied in a 

single continuous exposure, is that of the Mount Martin section, 1! miles west of Bisbee. As 

measured in this section the Abrigo limestone is 770 feet thick. It rests conformably upon 

the Bolsa quartzite and is overlain by the Martin limestone (Devonian). * * * 

The Abrigo limestone is distinguished from the other calcareous formations of the local Paleozoic section by its prevailing thin bedding, and particularly by a conspicuous laminated structure produced by the alternation of thin irregular sheets of chert with layers of gray limestone. 

The layers of limestone may be 2 or 3 inches in thickness, while those of chert are usually less. 

This cherty lamination is eminently characteristic of the Abrigo limestone in the Mule Mountains and serves as a ready means of identifying the beds belonging to this formation within the 

various fault blocks into whicp. the region is dissected. Chert also occurs occasionally in the Devonian and Carboniferous limestones of the Bisbee quadrangle, but as irregular bunches, never in the 

form of the thin, more or less anastomosing sheets peculiar to the Cambrian Abrigo limestone. 
CAMBRIAN AND LOWER ORDOVICIAN. 75 

The beds are commonly from 1 to 2 feet in thickness. Their dominant color as seen in 

large exposures is dark greenish yellow, whereas the prevailing tint of the overlying Mart.in 

limestone is dark gray, and of the still higher Escabrosa and Naco limestones white or light gray. 

In the typical Mount Martin section the Bolsa quartzite is immediately overlain by about 

40 feet of thin-bedded, very cherty limestones, which break up, on weathering, into thin rusty 

plates. Above this occur a few beds of gray limestone up to 2 feet in thickness, alternating 

with fissile yellowish calcareous shales, and with laminated cherty beds, such as have just been 

described. The upper 100 feet of the formation is made up of rather soft, sandy, thin-bedded 

gray limestone, with one bed of harder gray limestone 6 feet in thickness about 40 feet from the 

top. The upper limit of the Abrigo formation is defined in the Mount Martin section by a bed 

of pure white quartzite about 8 feet in thickness. 

This quartzite is a persistent stratum and is always found immediately underlying the 

Martin limestone, which carries Devonian fossils. Its thickness, however, is variable and it 

sometimes grades downward into the upper sandy limestones of the Abrigo formation. It 

apparently records the consummation of an increasing supply of sandy sediments during the 

later phases of the deposition of the Abrigo limestone and contrasts with the more purely calcareous beds of the overlying Devonian formation. * * * 

The fossils collected from the Abrigo limestone wer~ submitted to Dr. Charles D. Walcott, 

who kindly examined them and reported that they are middle Cambrian, indicating a fauna 

closely resembling that of the middle Cambrian of Texas. 

H 13. TRANS-PECOS TEXAS. 

With reference to the Cambrian and Lower Ordovician m the district about 

El Paso and to the southeast, Richardson 668 states : 

The formations which are the subject of this paper outcrop in the Franklin and Hueco 

mountains in the El Paso quadrangle, and in the Sierra Diablo, Delaware Mountains, and 

associated groups of hills in the Van Horn quadrangle. These two quadrangles, which have 

recently been mapped by the United States Geological Survey, are situated about 60 miles apart 

and they include practically all of the known occurrences of lower Paleozoic rocks in transPecos Texas. The following table summarizes the Paleozoic formations in the El Paso and Van 

Horn quadrangles: 

Paleozoic formations in the El Paso and Van Horn quadrangles, Texas. 

El Paso quadrangle. I Van Horn quadrangle. I 

Thickness I System. Series. Thickness Formation. (feet). (feet). Formation. 

Absent. 

I 

500+ Capitan limestone. 

00 

. I 

;:j Permian? (Guadalupian) . Delaware Mountain for- 0 

Absent. ... 2,000+ ~ mation. 

"2 ----· I 

Hueco limestone. I 3,000 0 Pennsylvanian. 2,500+ I Hueco limestone. ..0 

... 

"" Absent. c; Mississippian. Absent. I ! 

I 6 . Absent. :--§ ! Absent. i Q).~ I 

A>=~ I 

--- I 

Fusselman bd Absent. limestone. i 1,000 : ~·E (Niagara [fossils]). 

i I ~----

-----··· 

250 I ' UpJ?e! and Middle Ordo- Montoya 250 I Montoya limestone. limestone. -~ . I 0.:: VlClan. ---·---------· "'d.~ 

El Paso limestone. 1,000 c'"' Lower Ordovician. 750 I El Paso 1i~estone. --

·--

0-700 I Yan Horn sandstone.- ' d I 

Bliss sandstone. 0-300 i s oj·~ "" I Saratogan or Acadian. 

u,.El 
76 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The main occurrence of the Bliss sandstone is along the eastern slopes of the Franklin 

Mountains, but the considerable faulting to which the range has been subjected c~uses its distribution to be very irregular. The Bliss is a massive, fine-textured, brownish sandstone that 

varies from a few feet to slightly more than 300 feet in thickness. The lower beds are indurated 

and are practically quartzites and at the base of the formation the strata are coarser .textured, 

locally are conglomeratic and contain pebbles of the underlying rocks. The sandstone is com-

. posed of small grains of quartz embedded in a matrix of sericite and kaolin. In places the 

Bliss sandstone is in contact with granite of post-Carboniferous age and elsewhere it rests on 

rhyolite porphyry, of which it contains rounded pebbles in the basal beds. In the central part 

of the Franklin Mountains the sandstone thins out and locally disappears, and the overlying 

limestone, containing a basal conglomerate, lies directly on the rhyolite porphyry. 

Annelid borings both perpendicular and parallel to the bedding occur abundantly in the 

Bliss sandstone. Other fossils are rare, but in places in the lower strata some brachiopod 

shells ht.we been found. Of these Mr. Walcott has identified Lingulepis acuminata, Obolus 

matinalis( ~), and fragments of Lingulella which determine the Cambrian age of the rocks and 

indicate that either the upper or middle division of the system is here represented. 

The Van Horn is a medium to coarse-textured cross-bedded sandstone that is banded with 

thin lenses of conglomerate. The formation is of a prevailing brick-red color in its lower part, 

which becomes paler toward the top, where the color fades away and the sandstone is white. 

The conglomerate lenses vary from a few inches to about a foot in thickness and are irregularly 

distributed throughout the formation. At the base the pebbles are composed of fragments of 

the underlying rocks and consist of quartz schist, fine-textured red sandstone, cherty limestone, 

porphyry, and quartz, while the conglomerate in the upper part of the formation consists chiefly 

of well-rounded quartz pebbles. The sandstone likewise varies in composition, its lower part 

being composed of quartz and decomposed feldspar grains while the upper portion is prevailingly 

quartzose. The formation varies from a few feet to 700 feet in thickness and averages about 

400 feet. 

The Van Horn sandstone unconformably overlies highly tilted metamorphosed rocks and 

is overlain in places by the El Paso limestone (Ordovician), and elsewhere by the Hueco limestone (Carboniferous). The upper part of the formation contains numerous annelid borings and 

fucoid-like remains, but no characteristic fossils have been found in the sandstone and its age 

therefore is undetermined. 

The presence of sandstone at the base of the Paleozoic section in southwestern United 

States has been noted wherever observations have been made, and it is suggested that the Bliss 

and Van Horn sandstones are the probable equivalent of the Tonto sandstone of the Grand 

Canyon, the Bolsa quartzite of Bisbee, the Coronado quartzite of Clifton, the Reagan sandstone 

of Oklahoma, and the Cambrian sandstone of the central Texas Paleozoic area. 

The El Paso limestone outcrops in the Franklin and Hueco mountains in the El Paso quadrangle and in Beach and Baylor mountains in the Van Horn quadrangle. The formation is 

typically a massive gray magnesian limestone which contains the same fauna in both regions. 

In the El Paso area the formation is about 1,000 feet thick, the lower 100 feet of which is characteristically arenaceous and weathers brownish. A distinctive feature of the middle portion 

of the formation is the presence of thin connected nodules of brown chert arranged in irregular 

steaks parallel to the bedding. This limestone lies apparently conformably on the Bliss sandstone, but, as already stated, in the central part of the Franklin Mountains the Bliss sandstone 

is locally absent and the El Paso limestone rests directly on pre-Cambrian ( ?) rocks with a basal 

conglomerate varying up to 20 feet thick composed of rounded pebbles of rhyolite porphyry in a 

calcareous matrix. In the Van Horn quadrangle the El Paso limestone dpes not contain the 

cherty layers that are characteristic of the middle parts of the formation in the Franklin Mountains, and 50 feet above the base of the formation a thin bed of white sandstone is present. In 

this region there are indications of an unconformity at the base of the limestone marked by a 

slight undulatory contact between the El Paso and Van Horn formations. 
CAMBRIAN AND LOWER ORDOVICIAN. 77 

Mr. Ulrich reports that the fossils obtained from the El Paso limestone in both the El Paso 

and Van Horn quadrangles represent essentially the same Beekmantown fuana. Most of the 

species are undescribe.d, but all are of unmistakable types. The more characteristic forms are 

the following: 

Calathium sp. nov. (coral-like sponge), Maclurea ~ sp. nov. The small hornlike opercula 

are very common. The shell itself is of the type of M. oceana Billings. Solid siphuncles of 

endoceratoid cephalopod, evidently a close ally of Oameroceras brainardi. Besides these there 

are a number of less easily recognized small gastropods. 

H 14. LLANO DISTRICT, TEXAS. 

In Mason, Llano, and Burnet counties, Tex., the pre-Cambrian rocks are 

unconformably overlain by Upper Cambrian sediments. Shumard 8540 originally 

described the section. During 1908 and 1909 detailed surveys have been carried 

out by A. C. Spencer and Sidney Paige, and the following description is abstracted 

from notes furnished by them. 

UPPER CAMBRIAN. 

The Upper Cambrian of this area is essentially the equivalent of the Reagan sandstone 

in Oklahoma, agreeing with that formation not only in age but in lithologic succession. 

The Cambrian sediments rest upon a complex of metamorphic rocks which include schists, 

gneisses, and enormous masses of granitic intrusives. 

The Cambrian beds have been divided into three formations, namely, from the base upward, 

the Hickory sandstone, the Cap Mountain formation, and the Wilberns formation. 

Conglomerate and sandstone reaching a maximum thickness of about 250 feet constitute 

the lower formation. Following, but with a gradual transition from sandstone to limestone, 

are beds consisting predominantly of limestone, capped by 15 to about 75 feet of crossbedded glauconitic sandstone. These strata, about 90 feet thick, constitute the second formation. The third formation includes limestones and shales from 170 to 220 feet thick, the 

shale~ occupying approximately the upper third of the formation. 

The following section is characteristic of the lithology of the formations, though the thickness of the basal beds varies considerably, owing largely to the unevenness of the pre-Cambrian 

floor. 

Section of Hickory, Gap Mountain, and Wilberns formations on Packsaddle Mountain. 

Feet. 

Grayish slabby, slaty crystalline limestone; very little glauconite; more massive beds toward top 

of peak.................................................................................. 40 

Thinner-bedded crystalline limestone; some glauconite....................................... 20 

Heavy-bedded pink limestone, somewhat oolitic; contains some glauconite..................... 10 

Yellow and white sandstone with small percentage of glauconite, grading up into pink sandy 

limestone. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 

Glauconite sand and coarse quartz sands; iron concretions on surface ......................... . 6 

Massive-bedded grayish-brown crystalline limestone, somewhat oolitic; glauconite increasing 

toward top. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 

Flaggy subcrystalline limestone with small amount of glauconite; yellowish discolorations........ 30 

Grading into purer limestohe. Several red bands of sandstone alternating with beds of hard 

subcrystalline limestone and fine-grained whitish sandy limestone; crystalline limestone contains some glauconite grains............................................................... 3-'l 

Thin-bedded calcareous dirty-white sandstone, grading upward into very fine-grained hard 

reddish-brown sandstone. \Veathers rough but generally shows a brown sand on surface. 

Broken surface shows reddish-brown sandstone with crystalline faces of calcite. Makes cliffs 

which weather irregularly and show bands of red, yellow, and dirty-brown cross-bedded sandstone alternating with very calcareous beds ................................................ 200 

Ledge of calcareous sandstone, conglomeratic and containing a few shell fragments, also few glauconite grains. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 

Massive and thin-bedded red and yellow sandstone, with some shale, probably covered ..... 35 
78 

-----------------------------------------

INDEX TO THE STRATIGRAPHY OF NORTH .A1.1ERICA. 

Feet. 

Covered; mostly sandy shales. At bottom a 21-foot bed of red conglomerate sandstone with fiat 

pebbles; a few shell fragments in this ledge................................................ 10 

Mostly fine-grained dirty-white, brown, yellow, and red sandstone .............. __ .......... _. 45 

Massive pink and white, conglomerate sandstone, with white quartz pebbles mostly one-half 

inch in diameter; cross-bedded; prevailingly reddish tones. Near top grains are smaller and 

more rounded. Secondary infiltration of.quartz in cross fractures gives honeycomb structure 

on weathering........................................................................... 85 

567 

It will be noted that the sections are not complete. The following measurements include 

the upper portion of the Cambrian, or the Wilberns formation: 

Generalized section of Wilberns formation on east bank of Colorado River about one-third mile 

above old Tanyard Crossing. 

Ellenburger limestone at top. Feet. 

Impure limestone.......................................................................... 30 

Heavy-bedded limestone containing abundant exceedingly slllilll shell fragments, also abundant 

minute globular remains ................................................... _ ..... _ .... _.. 10 

Impure sandy limestone having conglomerate aspect in the hard layers......................... 10 

Debris-covered slope ...................................................................... _ 10 

Debris-covered slope; contains layers of shale conglomerate consisting of cemented fiat fragments 

of thin shale accompanied by layers "containing bowlder-like forms composed of limy mud. __ .. 60 

Slope of impure limestone layers breaking down to 1 inch in thickness, carrying fine sand, 

weathering light brown._ .... ___ ........... __ ........... _ ................... _ ..... _ .... _. 30 

Pink fiaggy semicrystalline limestone....................................................... 10 

Crystalline and semicrystalline bedded limestone, weathering into hard layers................. 11 

Heavy layer of mottled light-brown impure limestone........................................ 4 

Alternating beds of crystalline limestone, 4 inches to 1 foot thick, with crinkly-weathering beds 

that are slightly more sandy, the whole carrying finely disseminated glauconite, locally concentrated in layers .... _...................................................................... 23 

Base, recent silt of Colorado River. 

Another section of the Wilberns is as follows: 

Generalized section of Wilberns formation near head of Little Llano River. 

Ellenburger limestone at top. Feet. 

Calcareous shale, with subcrystalline to crystalline oolitic limestone bands; alternating hard and 

soft............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 

Thin fiaggy limestone with some sandy layers ... _ ........... _ ............................... . 

Shale and shaly limestone and subcrystalline layer with shell fragments ...................... . 

Conglomerate containing slightly rounded half-inch to l-inch pebbles, weathering yellow, with 

limestone matrix ........................................ _ ..... _ ........................ . 

Greenish-gray shales ........................................................... _ ........... . 

Two beds of conglomerate, about 8 inches each, separated by 8 inches of shale; small, slightly 

rounded calcareous pebbles weathering yellow ............................................. . 

Fine-grained greenish-gray shaly limestone ........................... _ ...................... . 

Conglomerate of long, fiat, thin, shaly calcareous fragments, overlain by fine-grained calcareous 

muds .................................................................................. . 

Greenish shaly limestone .................................................................. . 

Conglomerate composed of small, slightly rounded calcareous pebbles weathering yellow ........ . 

Light-gray shaly limestone, weathering to a covered slope ................................... . 

Thicker-bedded gray crystalline limestone, with scattered grains of glauconite; a few hard layer.3 

about 9 inches thick .................................................................... . 

Light-pink to gray thin-bedded fiaggy crystalline limestone, mottled brown by fine-grained sand .. 

Pink and gray crystalline limestone; glauconite grains at base .............................. . 

Pinkish sub crystalline limestone ........ ___ ...... _ .......... __ .......... _ ...... __ ............ . 

Sandy limestone and a little glauconite ............ _ ....................................... . 

Base at top of glauconite sand. 

10 

11 

1 

6 

2 

3 

3 

5 

1! 

25 

20 

17 

6 

7 

2 
CAMBRIAN AND LOWER ORDOVICIAN. 79 

This section was measured in dipping beds and the total thickness as stated is believed 

to be somewhat short of the actual thickness. The section is of value, however, as indicating 

the succession. 

Certain characteristics of these formations deserve a nwre detailed description. 

A wide diversity exists in the basal members. Locally they are fine-grained, cleanly washed 

sands; elsewhere they are coarse conglomerates with pebbles ranging from 6 to 8 inches in 

diameter. A marked relation was noted between the underlying pre-Cambrian and the basal 

layer. Certain coarse granites rich in pink feldspar have produced a pinkish-white conglomerate, in which the rounded quartz grains average a quarter of an inch in diameter and which 

contains numerous angular fragments of feldspar. A clean white cement consisting of small 

quartz grains and feldspar fragments with calcium carbonate binds the whole. In another 

place a coarser conglomerate stained red contains subangular quartz fragments as large as half 

an inch and feldspar fragments an inch long. A fine-grained quartz cement which included 

particles of iron oxide was the matrix. In another place a coarse sandstone containing 1 to 2 

inch fragments of hematite ma:kes up the basal layer, the iron having been derived from the 

underlying schists probably in the form of magnetite and later altered to hematite. In yet 

another place where the underlying formation is rich in pegmatite dikes, large angular masses 

of quartz are abundant in the lower beds. Here and there the lower member, where resting 

on a coarse-grained granite surface, is a granite arkose. 

In different localities the conditions of sedimentation undoubtedly varied, and this variation 

is expressed in the inadequacy of a hard and fast line between the Hickory sandstone and the 

Cap Mountain formation. The sandstones become gradually more limy, until the beds are 

predominantly limestone. In drawing a boundary line between two such formations, it is 

often difficult to decide upon a satisfactory line, though taken as a whole the two sets of beds 

fully justify such a separation. 

The distribution of glauconite in the Cambrian strata is interesting. Beginning in the Cap 

Mountain formation, it appears in scattered grains in the pure limestones and reaches its greatest 

development in cross-bedded sandstones, the top of which is Used as the boundary between 

the Cap Mountain formation and the Wilbems formation. Above this sand the glauconitic 

material gradually disappears. Though where observed in limestones the glauconitic grains 

exist essentially as such, in the sandstones the material is more likely to form the matrix in 

which the well-rounded clean quartz grains are embedded. 

UPPER CAMBRIAN AND LOWER ORDOVICIAN. 

The rocks overlying the Wilbems formation are of late Cambrian and early Ordovician age 

and have not been subdivided. They have been given the local name Ellenburger limestone. 

They are regarded by Ulrich as equivalent to a small portion of the rocks of similar age in the 

Missouri section and also to the lower part of the Arbuckle limestone of Oklahoma. In the 

greater number of places where the base of the Ellenburger limestone was observed, it is apparently conformable with the Wilbems formation. Many observations were made where no 

unconformity could be detected and where an apparent transition between the two formations 

could be followed. It must be noted, however, that the basal beds of the Ellenburger limestone 

vary in texture and appearance, and that this phenomenon is in itself a suggestion of unconformity. Any decision, therefore, must for the present remain tentative. 

At the top of the Ellenburger limestone there is usually, though not always, a conglomerate 

limestone bed, succeeded by the lowest portion of the Pennsylvanian (upper Carboniferous). 

The upper surface of the Ordovician on Doublehom Creek just south of the road crossing half 

a mile north of the mouth of Cordova Creek gives an excellent example of the pre-Carboniferous 

surficial conditions. 

The upper 25 feet of the Ordovician is composed of large angular blocks, very irregularly 

disposed, revealing a condition of peculiar surface breakage prior to submergence beneath the 
80 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

sea. As no coarse sediment is present, shallow, quiet Carboniferous seas must be inferred. 

The same type of breakage may locally be observed in stream channels and must not be confused 

with the basal conglomerate. Beds including the Mississippian (lower Carboniferous), Devonian, 

Silurian, and later Ordovician are therefore absent. 

As the Ordovician rocks lie immediately above the Cambrian, they occur at the crest of 

the Paleozoic scarp (unless faulting has intervened) and form the greater part of the Paleozoic 

surface in Llano and Burnet counties. 

Complete sections of the Ellenburger limestone are not easy to obtain. The general massiveness of the beds and the gentle folds and faults combine to prevent continuous record. 

Thicknesses up to 600 feet may be observed in the bluffs of the Colorado between Tanyard 

Crossing and Deer Creek. It is probable that the formation is 1,000 feet or more thick. 

The following section represents the upper portion measured near the mouth of Flat Rock 

Creek, Burnet County. 

Section measured in the upper part of the Ellenburger limestone near the mouth of Flat 

Rock Creek. 

Feo't. 

Carboniferous. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 

Grayish crystalline limestone with much chert ................................................ 15 

Crystalline limestone, brown and gray, sugar-grained texture, with light-colored chert; coarsely 

crystalline near top, greenish stains in calcite crystals ....................................... 25 

Massive, hard, smooth-textured beds at base, grading up into brown crystalline and coarse gray 

limestone; sorne chert. ................................................................... 22 

Alternating sugary and smooth-grained beds; at top a bed of cherty limestone, weathering honeycomb fashion ....................... , ..................................................... 11 

Alternating sugary and smooth-grained beds; but little chert ................................... 11 

Brown, sugary banded limestone with some chert................................... . . . . . . . . . 5 

Smooth light-gray limestone with whitish chert, weathering bluish gray; smooth rounded pieces 

simulating waterworn bowlders on surface .............................................. : ... 50 

Light-gray smooth limestone, conchoidal fracture; contains some chert which weathers out into 

rough surface; alternating thin and massive ................................................ 22 

Brown, sugar-grained limestone containing layer of white chert........ . . . . . . . . . . . . . . . . . . . . . . . . 2 

Irregularly bedded dark and light brown, sugar-grained limestone; tesselated weathering in cliff. 11 

Brown and gray crystalline limestone; lowest portion contains some chert..................... 3! 

Rough-weathering, somewhat concretionary limestone, sugar-grained, brown and mottled pink.. 2 

Massive beds of brownish-gray smooth limestone, irregular fracture............................ 4 

Gray crystalline limestone, massive bedded, sugar-grained, mixed with smooth noncrystalline 

variety................................................................................. 5! 

Brown and light-colored fine sugar-grained crystalline limestone, mostly thin and irregularly 

bedded ................................................................................ ·. 17 

Local bowlder bed resembling conglomerate, sandy materiaL................................. ll 

Brown and light-colored fine sugar-grained crystalline limestone, mostly thin and irregularly 

bedded but makes jagged cliff ............................................................ 27! 

Bottom at level of Colorado River. 

Certain characteristics of the Ellenburger limestone are pronounced. The bedding as a 

rule is ill defined, preventing correlation by lithologic units. Repetitions of coarse or fine 

grained phases of the limestone occur in alternating succession, but the position of individual 

beds, because of their great similarity, was not determined. An abundance of white and yellow 

chert characterizes the series, though some layers are free from this material. Wbere relief is 

considerable and dissection of the plateau has taken place, the surface of the formation is 

exceedingly rough, and in general the formation may be recognized by this irregularity of 

surface. This condition does not apply to the high rolling grass lands to the north. In certain 

layers the chert has evidently been dissolved and replaced by crystalline quartz filling irregular 

cavities. 
CAMBRIAN AND LOWER ORDOVICIAK. 81 

I 12. ARIZONA.a 

The Tonto group is recognized by Reagan/63 who states: 

The Tonto formation is composed of coarse to fine grained, often cross-bedded vitreous 

sandstones and sandy shales, varying in color from brown to red, purple, and white. The formation is the surface rock of a large area. The Sierra Ancha Mountains are capped with it. It is 

exposed all around the rim of the Tonto-Cherry Creek basin and continues on the east from that 

basin beyond the headwaters of Oak Creek in the latitude of Chiddessky on Canyon Creek. 

From this point it extends in an ever-widening strip along the plateau south across Salt River 

to the Apache and Nantan mountains. Patches of it also occur in the Apache and Pinal 

mountains. In short, the Tonto exposures completely. encircle the Archean and Algonkian 

areas of the Salt River and Canyon Creek region. That it once covered the entire Archean and 

Algonkian area is attested by the vitreous sandstone points and buttes scattered over the 

country, among which are points Chiddesche and the Twin and Sombrero buttes. 

I 13. NEW MEXICO. 

Lindgren 542a gives the following account of the Cambrian and Ordovician of 

New Mexico: 

The pre-Cambrian history of the Territory, though imperfectly known, indicates a period 

of sedimentation followed by mountain building and igneous intrusion, which was in turn 

succeeded by long-continued erosion that exposed the intrusive cores. At the base of the 

Paleozoic section is a strongly pronounced unconformity. In general it has a fundamental 

appearance, as, for instance, where sandstones and limestones rest horizontally on vertical 

gneisses. 

In the whole of northern New Mexico the Pennsylvanian or upper Carboniferous rests 

directly on the pre-Cambrian, and these conditions appear to continue as far south as Socorro. 

Cambrian rocks were first definitely recognized in New Mexico in 1905 by C. H. Gordon,b who 

found fossils of this age in the Caballos Range, along the thirty-third parallel. The thickness 

of the Cambrian quartzite and shales, which here underlie the Ordovician limestone, is only 

55 feet. In the Mimbres Mountains, near Kingston, the thickness is 75 feet, and in the Florida 

Range, southeast of Deming, 135 feet of quartzites were measured in the same stratigraphic 

position. Toward the west, near Silver City, L. C. Graton measured a thickness of nearly 

1,100 feet of quartzitic sandstones, including some strata of limestone. Across the Arizona 

line in the same latitude Waldemar Lindgren c found 280 feet of quartzites, with some shales, 

resting on granite underneath the Ordovician and obtained near the top of these rocks some 

fossils suggestive of the Cambrian. In the Franklin Mountains G. B. Richardson d found 150 

feet of sandstone containing Upper Cambrian fossils. At Bisbee, in southern Arizona, F. L. 

Ransome measured 400 feet of nonfossiliferous, probably Cambrian sandstone, covered by 

750 feet of fossiliferous Middle Cambrian limestone. This is the only known occurrence of 

heavy Cambrian limestone in this region, although it is possible that some of the limestone 

which in southwestern New Mexico covers the quartzite may also be of Cambrian age. 

All this indicates beyond doubt that during the period preceding the Cambrian the whole 

of western New Mexico, so far as available exposures permit a judgment, was a land area which 

gradually became planed down from a very high to a more moderate relief. During the Cam-

'brian period the sea appears to have advanced northward, but only to about latitude 33° 30', 

where the Cambrian deposits seem to thin out. The greatest thickness of sediments is found 

a See also I-J 12, Grand Canyon, Arizona (pp. 88-89). 

b Gordon, C. H., and Graton, L. C., Lower Paleozoic formations in New Mexico: Am. Jour. Sci., 4th ser., vol. 21, 

1906, pp. 390-395. 

c Clifton folio (No. 129), Geol. Atlas U. S., U. S. Geol. Survey, 1905. 

d Tin in the Franklin Mountains, Texas: Bull. U. S. Geol. Survey No. 285, 1906, pp. 146-149. 

48011°-12-6 
82 INDEX TO THE STRATIGRAPHY OF NORTH A1\1ERICA. 

at Silver City. In the Caballos Range there appears to exist a gradual transition between 

quartzitic sandstone and underlying granite, suggestive of secular decay of the granite, 

preceding deposition. 

It is interesting to note that the Ordovician, Silurian, Devonian, and lower Carboniferous 

(Mississippian) are likewise lacking in northern New Mexico, and that they begin to appear 

prominently at about latitude 33° 30'; some exposures of the Mississippian have been recognized at about the latitude of Socorro, or 34 °. * * * 

The Ordovician rests conformably on the Cambrian and consists of 450 to 1,200 feet of 

usually cherty limestone, very poor in fossils. It has been recognized in the Caballos Range 1 

in the Mimbres Range, and at Silver City and other places. 

I 14-15. OKLAHOMA. 

In the Arbuckle Mountains of Oklahoma the Upper Cambrian and Lower 

Ordovician are represented by the Reagan sandstone and Arbuckle limestone. · 

Taff 808 gives the following descriptions: 

In pre-Cambrian [late Cambrian] time the region of the Arbuckle uplift was submerged, 

and the Reagan sandstone, the lowest Cambrian sediment, was laid down upon the eroded 

surface of the granite and porphyry as a beach and off-shore deposit. The pre-Cambrian 

land, composed of igneous rocks, possessed some relief at the time of submergence, as is shown 

by ,the uneven contact of the igneous rocks with the Reagan sandstone and also by the variable 

nature of the sandy deposits. The land in the immediate vicinity of the uplift was soon submerged, however, as is shown by the presence of fossiliferous horizons representing the same 

mid-Cambrian time in the upper member of the Reagan sandstone wherever it is exposed. 

CAMBRIAN ROCKS. 

Reagan sandstone.-This sandstone is a variable formation, as regards both its thickness 

and the nature of its materials. In the eastern part of the uplift, in contact with the granite, 

it varies in thickness from a few thin beds to approximately 500 feet, with an average thickness 

of about 300 feet. In its thickest portion, at the western and of the granite, the lowest beds 

are composed for the most part of coarse arkose grit. The following is a record of the thickest 

se~tion of the Reagan sandstone as it occurs at the western end of the granite area, beginning 

at the base: 

Section of Reagan sandstone. 

Feet. 

Quartzite and arkose conglomerate, co~ posed of poorly sorted granitic materials ............... · 30 

Coarse grit and sand, with some clay and green sand in upper part, generally well stratified .... 370 

Thin-bedded and laminated sandstone, becoming calcareous in the upper part.............. .. .. 60 

This section is followed by generally thin-bedded siliceous li_mestone and shaly strata 

through several hundred feet to the top of the middle Cambrian. The calcareous beds at the 

top and above the Reagan contain numerous fossils of well-defined middle Cambrian forms. 

The Reagan sandstone overlying the porphyry in the southern sides of the East and West 

Wooded hills has a section similar to that in contact with the granite. The coarse materials 

which make lentils of conglomerate near the base, however, are here composed of porphyry 

and associated dike rock. In the upper part of the formation greenish clays are probably 

more abundant, and the green sand continues higher up into the more calcareous beds. As 

in the occurrence near the granite, here the calcareous rocks contain numerous middle Cambrian 

fossils. 

CAMBRO-ORDOVICIAN ROCKS. 

Arbuckle limestone.-The Arbuckle limestone, with the exception of thin, shaly strata 

and occasional siliceous and cherty beds, is composed entirely of light-blue and white limestone 

and cream-colored to white crystalline dolomite. The section ranges in thickness from 4,000 
CAMBRIAN AND LOWER ORDOVICIAN. 83 

to 6,000 feet, and includes the whole of the upper Cambrian and the Calciferous of the Ordovician. From the base of the formation upward to the top of the middle Cambrian the rocks 

are composed of thin-bedded and, in part, intraformational conglomerate and shaly limestones. 

While pursuing stratigraphic field work in connection with the study and collection of the 

fossils, Mr. E. 0. Ulrich noted the occurrence of what appeared to be shaly lentils at the top 

of the middle Cambrian, indicating to his mind an unconformity between the upper and lower 

Cambrian. 

Beginning with the upper Cambrian the rocks are composell of massive and hard, pink to 

yellow crystalline limestone and dolomite, which weather to various shades of brown and almost 

black. Rocks of this character have a thickness of 500 to 600 feet, and are followed by lightercolored massive dolomite and limestone, without any indication of time interval, up into the 

Ordovician. Beginning approximately 450 feet below tho top of the Arbuckle formation the 

limestones become more thinly bedded and are associated with thin and, in places, shaly strata. 

Very near the top occasional sandy beds occur. 

In the massive beds in the central part of the formation fossils are found, but not in great 

abundance. Near tho top, however, where the rocks become argillaceous, fossils are more 

common. Fossils of a number of genera, mostly undescribed, occur in the upper 1,250 feet 

of the Arbuckle limestone. 

The Reagan sandstone and the Arbuckle limestone in the Wichita Mountains 

of Oklahoma are described by Taff 808 as follows: 

The Reagan sandstone is the lowest Cambrian formation in the Wichita region, and it 

rests on the eroded uneven surface of the granite porphyry, from which most of its materials 

have been derived. * * * 

The Reagan sandstone is approximately 300 feet thick and is composed of hard and soft 

sandstone, grit, conglomerate, ilhales, and siliceous shell limestones. The section of the formation is essentially the same as in the western end of the Arbuckle Mountains. In each case 

porphyry is beneath it, and tl:le limestone which overlies the Reagan is of the same nature and 

contains the same fossil fauna. In both localities the Reagan formation is made up of conglomerate composed of porphyry pebbles and included basic rocks, gritty light-brown to gray 

and greenish sandstones, greenish clay shales, and siliceous limestones, interstratified. Th0. 

limy layers contain many species of Cambrian fossils, which were carefully collected, but which 

have not yet been thoroughly studied. The conglomerate occurs invariably near the base as. 

local beds or lentils, while the calcareous sandstone and limestone beds are without exception 

in the upper part of the formation. * * * 

Above the Reagan formation in conformable succession is a great limestone section essentially the same as the Arbuckle formation in the Arbuckle Mountains, where the lower part, 

practically the lower third, was found to be Cambrian and the upper two-thirds Ordovician 

in age. Near the transition zone, between the rock of the two periods, very few fossils have 

been found, so that precise distinctions as to age can not be made at the present time. The 

same conditions of deposition seem to have occurred in the Wichita region as in the Arbuckles, 

and the rocks must be classified in the same manner. There seems to be no reason to doubt 

that the formation is continuous from one region to the other beneath "Red Beds" deposits. 

E. 0. Ulrich contributes the following note regarding the Reagan sandstone: 

The Reagan sandstone includes most of the Cambrian deposits exposed in the uplifts of 

the Arbuckle and Wichita mountains, in south-central and southwestern Oklahoma, respectively. The formation as described by J. A. Taffa and as observed by me consists of two members. The lower is a brown sandstone, coarse grained and ill bedded below; finer grained, 

laminar, and shghtly calcareous above; varying greatly in thickness because it rests directly 

on the uneven pre-Cambrian granite floor. The upper member, though not sharply separated 

a Tishomingo folio (No. 98), Geol. Atlas U. S., U. S. Geol. Survey, 1903. 
84 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

from the lower, is the more persistent and is readily distinguished lithologically, being composed 

of interbedded thin glauconite limestones and thin layers of greenish shale, together making up 

a thickness of about 80 feet. Some of the limestone layers in the upper half are conglomeratic 

and many of those in the lower half are filled with fossils. This upper member is an easily 

recognized and Widely distributed division. 

A basal sandstone, overlain by a thin-bedded limestone carrying glauconite and containing 

the same fauna as that found in this upper member of the Reagan sandstone, occurs at the base 

of the eo-Paleozoic column in the Llano and Burnet quadrangles, in central Texas. Very 

similar, apparently contemporaneous deposits and faunas are found also in New Mexico, Arizona, 

and the Bighorn Mountains of Wyoming. Further, the same fauna, though the rocks depart 

somewhat lithologically, is yet easily recognized in the Lamotte sandstone and Bonneterre 

limestone, perhaps also in the Elvins formation of the Ozark uplift and in the "St. Croix group" 

of the upper Mississippi Valley. 

I 16. ALABAMA AND GEORGIA.a 

The Cambrian of the southern Appalachian Valley region is represented by 

the -Weisner quartzite, Beaver limestone, and Rome formation, by the Conasauga 

shale, and by part of the Knox dolomite. The upper part of the latter is of Lower 

Ordovician age. Hayes 428a described these formations as follows: 

The Weisner quartzite includes the oldest rocks that come to the surface within the limits 

of the Rome quadrangle. It is confined to the extreme southwest corner; and since it contains 

the most resistant rocks, the areas of its outcrop are marked by the greatest elevation within 

the quadrangle-that is, Indian Mountain. The most prominent member of the formation is a 

hard, vitreous quartzite, but it contains also conglomerates, sandstones, and sandy shales. The 

coarser elements of the formation constitute a series of lenses, variable in extent and thickness, 

which are interbedded with the finer-grained rocks. The latter make up the bulk of the formation, although they are much less prominent than the more resistant coarser beds. The quartzite 

when exposed to atmospheric agencies breaks up into angular blocks, which nearly everywhere 

cover the surface, and exposures of the beds in place are rarely seen. For this reason, and also 

because of the enormous faults which intersect the formation, its thickness is difficult to determine. On a section from Bluffton to Rockrun its apparent thickness is over 10,000 feet, but it 

is by no means certain that this apparent thickness is not due in some measure to repetition by 

faulting and the minute folding of the less resistant beds. The section is limited by a fault on 

the west, and the foundation upon which the formation was originally deposited is nowhere 

exposed. Some of the conglomerate beds contain numerous feldspar pebbles, showing that the 

material composing the conglomerate was derived, in part at least, from granites. It probably 

came from a source to the southeast, and the beds which form Indian Mountain have the 

appearance of massive delta deposits. No fossils have as yet been found in these beds, but their 

relations to adjacent formations are such that there is little hesitation in correlating them with 

the lower Cambrian. 

The beds of the Weisner quartzite generally dip to the southeast and, where not limited 

by a fault, pass under a narrow belt of red clay soil containing many angular fragments of 

quartzite and a few masses of cellular chert. This red soil is derived from the decay of the 

Beaver limestone, which is itself rarely seen. It is a gray, semicrystalline, dolomitic limestone, 

generally massive, but sometimes slightly shaly. The exposures of this limestone are so infrequent that its thickness can not be determined, but, judging from the width of its outcrop and 

the prevailing dip of the adjoining beds, it is probably between 800 and 1,200 feet thick. The 

principal areas of the Beaver limestone are in the vicinity of Indian Mountain, but a small 

area is found at a considerable distance from any outcrop of the quartzite, a few J11iles southwest of Rome. 

a See also I-J 16-17, Tennessee and North Carolina (pp. 89-98). 
CAMBRIAN A~D LOWER ORDOVICIAN. 85 

The Rome formation consists of thin-bedded, fine-grained sandstones and sandy shales. 

Its most striking peculiarity is the brilliant coloring of its beds. The prevailing colors are 

various shales of reel, purple, green, yellow, and white. The changes in color are often very 

t:tbrupt and the exposures of the formation present a distinctly banded appearance. The base 

of the formation, where it is found resting upon the underlying Beaver limestone, consists of 

thin-bedded red sandstones, and the top of the formation is characterized by a rather heavy · 

bed of white sandstone. Northeast of Rome the upper portion of the formation consists 

chiefly of shale and is distinguished on the map as a lentil in the formation. In its type locality, 

south of r{ome, the formation is between 700 and 1,000 feet in thickness. Its becl.s are always 

more or less folded, so that it is impossible to make exact measurements of its thickness. The 

formation is confined to a narrow belt crossing the quadrangle diagonally from northeast to 

southwest at the eastern margin of the Coosa Valley. Its rocks are somewhat more resistant 

than the limestones which occur above and below, and it forms a line of low ridges between the 

lowlands on either side. 

The Conasauga formation presents a number of widely differing phases within the limits 

of this quadrangle. At its type locality, in the Dalton quadrangle to the northeast, it consists 

of a great thickness of fine day shales with occasional beds of limestone. The latter vary in 

thickness from a few inches to several hundred foot, and are always rather pure, blue limestone. 

In the vicinity of Rome and northeastward to the margin of the quadrangle, the formation 

consists at the base of several hundred feet of fine olive clay shale, then beds of oolitic limestone, 

and finally 1,000 or more feet of calcareous shales, interbedded towanl the top ·with blue limestones. Southward from Rome the formation changes considerably by an increase in the 

amount of limestone. A typical section is exposed on Big Cedar Creek, where it crosses Vans 

Valley. The lower part of the formation consists of olive shales, above which are oolitic limestones, the same as at Rome. The upper portion of the formation, however, consists largely 

of heavy beds of limestone. Some of these limestone beds are gray and crystalline, closely 

resembling the Knox dolomite, but free from the compact nodular chert of the latter formation. 

Other beds contain considerable earthy matter, which often retains the form of the rock after 

the calcareous matter has been removed, and also masses of characteristic cellular chert. The 

two phases of the Conasauga formation above described are confined to the strip of lowland 

between the Rome sandstone ridges and the Knox dolomite plateau which occupies the southeastern half of the quadrangle. 

Northwest of the Rome sandstone ridges there is a much larger area of the Conasauga 

formation, occupying the greater part of the Coosa Valley. The formation here varies somewhat ·widely from the type to the cast, and is capable of subdivision into three rather distinct 

phases. The upper portion of the formation, along the eastern margin of the Coosa Valley, 

consists of characteristic greenish siliceous shales. These have been separately mapped and 

are indicated on the sheet as a lentil in the formation. In some cases the shales are replaced 

by greenish micaceous sandstone, which is always highly contorted and crushed into a series 

of lenticular masses from a fraction of an inch to 4 or 5 inches in thickness. The sandstone is 

always filled with cracks or fissures, which have the appearance of having been produced by 

contraction of the bed. These cracks are partially filled with quartz, and where they are 

unweathered the remaining space is occupied by calcite. The sandstone is confined to the 

southeastern margin of tho valley. Northwestward the siliceous beds become fewer, being 

replaced by fino olive-green shales, and throughout the central portion of the valley this division 

is represented by olive shales, in which occur numerous fiat concretions composed of gray 

siliceous rock intermediate in character between fine-grained quartzite and chert. Along the 

northwestern border of the valley this division becomes very much more calcarepus. The 

concretions are similar in appearance to those above described, but are composed of siliceous 

limestone. As the shale holding these siliceous concretions weathers they collect upon the 

surface and resemble deposits of waterworn gravel. The intermediate division of the Conasauga 

as it occurs in the Coosa Valley is composed of clay shales containing varying amounts of limestone. The limestone appears in some places as a few thin bods scattered through the shales, 
86 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

and in others as massive beds, frequent!_,. several hundred feet in thickness. In some places 

the limestone, instead of forming continuous beds, occurs as flat lenticular masses, an inch or 

less in thieknoss, rather closely erowded in tho fine shales. The lower portion of the formation 

consists wholly of fine clay or slightly sandy shales, which appear yellow or brown at the surface 

and dark bluish gray or black below drainage. 

These three subdivisions merge into one another without sharp boundaries. The formation 

contains no single stratum sufficiently characteristic to be identified at different outcrops and 

thereby used as a datum for the subdivision of the formation, so that the siliceous beds are 

representBd only as a lentil in the formation. The rocks of the Coosa Valley are everywhere 

highly contorted and are probably also intersected by numero.us faults. For these reasons, and 

also because large areas in the valley are deeply covered by.recent gravels, it is impossible to 

estimate even approximately the thickness of the formation as a whole or of any of its subdiVISIOns. The fact that the formation occupies such a broad area suggests, however, that its 

thickness must be very considerable, probably several thousand feet. In addition to the areas 

already described, the Conasauga forms a number of narrow belts in the northwestern portion 

of the quadrangle. These occupy the axes of narrow anticlinal rolls or are brought to the surface 

by faults. The formation here has much the same character as in the type locality; that is, 

it consists of fine clay shales with occasional beds of blue limestone. The Conasauga formation 

differs so widely in character in the closely adjoining regions that, except for the evidence 

derived from the fossils, the two phases would scarcely be correlated. Nothing resembling 

the upper siliceous division occurs in the region east of the Rome sandstone belt, and, on the 

other hand, the characteristic oolitic limestone of this eastern region is wholly wanting in the 

Coosa Valley. 

Two explanations of these differences are suggested. The first is that there may have been 

a barrier of land between the two areas of deposition, so that the rocks of the Coosa Valley 

and those south of the Coosa fault were laid down in separate, though contiguous, basins. 

Deriving their sediments from different sources, they would differ in lithologic character, while 

the faunas might be essentially the same. No trace of such a land barrier, however, has yet 

been found, and the rocks in question contain none of the characteristic marks of littoral 

deposition. The second explanation is that the rocks now occupying adjacent areas at the 

surface were originally deposited in comparatively remote parts of the same sea, but have been 

brought side by side by folding and faulting, and that the observed lithologic differences are 

due to the gradual change which is always found upon tracing a bed for a considerable distance. 

The contrast in character is greatly heightened by the elimination of the intermediate varieties 

and by the most widely different types being brought into immediate contact, where comparison 

reveals diiierences which in the normal relation of the beds might escape notice. The two 

regions are separated by the Coosa fault, which will be more fully described later. It is quite 

possible that rocks now in contact on opposite sides of this fault were originally separated by 

an interval of 10 or 15 miles, and that the intervening rocks, now entirely concealed, would, 

if restored, present all the intermediate varieties between the two sharply contrasted phases 

of the formation. 

The Knox dolomite consists of from 4,000 to 5,000 feet of massively bedded and somewhat 

crystalline gray magnesian limestone. From the few fossils which have been found it appears 

probable that a transition from Cambrian to Silurian occurs in the lower third of the formation, 

but it is generally impossible to determine this line of division, so the whole formation is classed 

as Silurian on the historical-geology sheet. This limestone, or, more properly, dolomite, 

contains a large amount of silica in the form of nodules and layers of chert, an impure variety 

of flint. Upon weathering, that part of the rock whieh consists of the carbonates of lime and 

magnesia is dissolved, leaving behind the chert, usually embedded in red clay. This residual 

material covers the surface to a great depth, and the dolomite is seldom seen except in the 

stream channels. Unlike the underlying Conasauga formation, the Knox dolomite affords 

some indication of having been deposited in proximity to land toward the east. In a few 

places the chert beds are replaced by coarse sand disseminated through the dolomite, in some 
CAMBRIAN AND LOWER ORDOVICIAK. 87 

cases making it a calcareous sandstone. This sand increases in abundance toward the east, in 

which direction, therefore, its source probably lays. 

The Knox dolomite occurs in a number of belts, from 1 to 3 miles in breadth, in the notthwestern portion of the quadrangle, and also forms the surface in a much broader area which 

occupies nearly the whole of the southeastern third of the quadrangle. These areas are characterized by a hilly surface which is usually several hundred feet above the adjoining lowlands. 

Since exposures of the dolomite are rare, the extent of the formation is determined by means 

of the residual chert which covers its outcrops. In the vicinity of faults the chert is frequently 

.altered by partial recrystallization of the siliea and converted into a white granular ro9k w:hieh 

readily crumbles on exposure to the air. Hence, those portions of the formation whieh have 

undergone this alteration weather to a red siliceous clay soil. This can not be easily distinguished 

from the soil derived from the Beaver limestone and from portions of the Conasauga formation. 

Considerable uncertainty, therefore, pertains to the mapping of these three formations, particularl;y?fin a much faulted region, as in the vicinity of Indian Mountain.a 

The Ocoee group of Safford, which comprises a great thickness of coarsely 

clastic strata, together with some finer sediments, is very widely developed in Alabama and Georgia. The strata are in general much metamorphosed. Hayes 428b 

states: 

The Ocoee series, whose age is not definitely known, was deposited for the most part near 

the margin qf the sea, where the supply of land waste was abundant but subjeet to great 

fluetuations. Fine sediments alternate with coarse material, and few of the formations retain 

the same characteristics for long distances, except in a very general way. During a part of the 

Ocoee epoch there were in this region several granite islands, whose waste was deposited about 

them as basal conglomerates. Later these islands were entirely covered by the sea and by 

the sediments derived from more distant lands and spread over the sea bottom. The extreme 

metamorphism whieh the rocks of this series have undergone toward the east renders it difficult 

to determine their original limit in that direction or their relation to the older rocks beyond. 

Hayes and Eckel 429 give the following more detailed account of certain aspects 

and relations of Safford's Ocoee in Bartow County, Ga.: 

The rocks on the opposite side of the Cartersville fault, occupying the eastern half of the 

district, present eonsiderable variety in composition and age. A large area, extending from 

Stamp Creek southward across the Etowah River, to the Atlantic & Western Railroad, is occupied 

by the Corbin granite, which is, for the most part, a massive eoarse-grained rock, containing 

large porphyritie crystals of feldspar (microcline), in a groundmass of plagioclase feldspar, 

muscovite mica, and blue quartz. Some portions of the roek have undergone considerable 

alteration, by which it has been converted into an augen gneiss. This area of Corbin granite 

at one time probably formed an island, since it is surrounded, in part a,t least, by rocks derived 

from its waste. These are feldspathic conglomerates in which the blue quartz and the porphyritic crystals of microcline, which characterize the granite, can be readily distinguished. 

In some places the transition from granite to conglomerate is so gradual that it is difficult to 

determine the exact boundary between the two formations.. The development of the gneissoid 

structure in the granite evidently took plaee after it was deeply buried by sediment, for the alteration of the latter is even more marked than that of the granite itself. Wherever the granite 

is not bordered by coarse conglomerate or quartzite it is in contact with black graphitic slates, 

which generally overlie the coarser sediments. 

These conglomerates and slates associated with the granite belong to the Ocoee series, 

which reaches its greatest development in eastern Tennessee and western North Carolina. No 

fossils have yet been found in the rocks of this series, although many of them are only slightly 

altered. They contain limestones and slates similar to portions of the adjacent valley formaa See abo quotation from report on the Birmingham district, pp. 164-165. 
8'8 INDEX TO THE STRATIGRAPHY OF NORTH AJ\fERICA. 

tions, but the latter are always found to contain more or less abundant traces of life. In the 

absence of fossil evidence their age can not be definitely determined, but on structural evidence, 

obtained chiefly in Tennessee, they are believed to be Lower Cambrian with possibly some 

pre-Cam brian. 

The rocks of the Ocoee series generally show an increasing degree of metamorphism toward 

the southeast; and within a few miles of this region they pass into schists and gneisses, the 

original form of which, whether igneous or sedimentary, can not be readily determined. This 

increased metamorphism toward the southeast is due in part to the greater compression which 

that region has suffered, and in part to the presence of considerable bodies of various igneous 

rocks which have been intruded into the sedimentary beds. These intrusive rocks present 

t~onsiderable variety in composition, varying from extremely basic diabase to acid granites. 

The most common variety is a diorite, which was among the earlier intrusions, and has been 

subsequently converted for the most part into amphibolite schist. Two belts of this basic 

schist pass across the southeastern corner of the district. Its southeastern corner is occupied 

by the Acworth gneiss, which, like the Corbin granite, is probably Archean in age, and formed 

the foundation on which the oldest sediments of the region were deposited. 

Among these probably pre-Cambrian schists occur some strata which, though 

highly metamorphosed, are of late Paleozoic age. Thus E. A. Smith records the 

discovery of plant remains near Mosely, Clay County, Ala., in "semicrystalline 

(sericite) slates of the Ocoee type * * * at the eastern base of the main range 

of the Talladega Mountains * * * 8 miles or more from the contact of the 

'Ocoee' with the unaltered Cambrian of the valley." David White 747 reported 

on the plants as follows: 

Your specimens represent several fragments of large cones in which the axes, the basal, 

sporangiferous portions of the spirally arranged bracts, the rhomboidal compressed sporangia, 

and the megaspores are well defmed. Precise identification of the material is deferred pending 

the study of thin sections and the determination of certain points regarding the sporangia! walls 

and their attachment to the basal portions of the bracts. It is clear, however, that we have 

here fragments of cones whose superficial features appear to represent the common Lepidostrobus 

type of the upper Paleozoic. Beds containing lepidophytic remains of this type can hardly 

be older than Devonian at earliest, and should not antedate the J\Iiddle Devonian. 

The general proportions and aspect of the cones are suggestive of some of the Carboniferous 

forms. Although the internal structure of the strobili may be found to indicate a more highly 

organized genus than Lepidostrobus, we may rest assured that the material is not older than the 

upper Paleozoit lepidophytes. 

I-J 12. GRAND CANYON, ARIZONA. 

The Tonto group comprises a sandstone at the base and shales and limestones 

above. vValcott 851a gives the following section: 

The Tonto section at the head of Nunkoweap Valley is as follows, from top downward: 

Feet. 

1. Massive mottled limestone............................................................. 60 

Fossils: Lingulepis and Ptychoparia. 

2. Evenly bedded yellowish sandstone ............................................ _._.... 25 

3. Mottled and variegated calcareo-arenaceous rocks........................................ 340 

4. Thin-bedded sandstones.............................................................. 325 

Fossils (near base): I-ingulella, Acrothele, Iphidea ornatella, Hyolithes, Leperditia (three 

species), Dilichometopus, Olenoides, and Ptychoparia. 

5. Fine-grained passing into coarse reddish-brown sandstone in layers....................... 300 

1,050 
CAMBRIAN AND LOWER ORDOVICIAN. 89-

The base rests unconformably upon the Chuar shales, etc. Xos. 4 and 5 are referred to 

the Middle Cambrian, and tho strata above to the Upper Cambrian. 

In 1883 Walcott 846 wrote: 

The geologic age of the Tonto group is determined by the presence of numerous specimens 

representing the genera Cruziana, Lingulepis, Iphidea, Conocephalitos, Crepicephalus and 

Dicellocephalus that occur at various horizons in the upper 700 feet of sandstone, shales and 

limestone. No fossils were obtained from the coarse sandstone forming the lower 300 feet. 

The fauna above, however, shows close relations to that of the Potsdam sandstone horizon of 

central K evada, the Mi~sissippi Valley, and Saratoga County, X. Y. 

The base line of the Tonto is quite uniform and rests unconformably on the varied strata 

beneath; here and there a knoll, point or ridge is seen on the pre-Tonto surface that rises nearly 

through the massive Tonto sandstones that were deposited against and over them,. the sea 

breaking off, and burying with the drifting sand, fragments of the rocky islands. 

The great unconformity beneath tho Tonto has been described by Prof. J. W. Powell, who 

examined it in his boat trips down through the Grand Canyon, and by Capt. C. E. Dutton, who 

viewed it from the summit of the Kaibab Plateau, 5 miles away. Prof. Powell estimated the 

strata beneath the Tonto and above the Archean at 10,000 feet, and as this is all cut across the 

unconformity is very great. A detailed study adds to the thickness of tho strata; it shows that 

the original summit of the pre-Tonto group had undoubtedly been cut away more or less before 

the deposition of the Tonto group; that tho plane of erosion cut deeply into the Archean, and 

that besides the 13,000 feet of strata, that have been planed oif, of which tho record is found in 

the section preserved, there was also a problematical amo~nt of considerable thickness. 

I-J 16-17. TENNESSEE AND NORTH CAROLINA. 

In eastern Tennessee and North Carolina two distinct sequences of strata are 

assigned to the Cambrian. One consists of the sparsely fossiliferous siliceous group 

to which Safford applied the name Chilhowee sandstone but which has been subdivided by Keith into several formations, and the overlying richly fossiliferous, generally calcareous deposits which constitute the Apison, Beaver, Rome, Conasauga, 

and Knox formations and some minor divisions of local extent; these are found in 

the valley region of east Tennessee. The other sequence is the more or less metamorphosed unfossiliferous Ocoee group of Safford, composed in part of coarse clastic 

deposits with slate and subordinate limestone, which form ·large masses of the 

Great Smoky Mountains. Keith 480 has demonstrated the conformity of Safford's 

Ocoee to the fossiliferous Cambrian and classes it as Cambrian on grounds of 

physical relationship. He says: 

With tho deposition of the Cambrian rocks there came a great change in the physical 

aspect of this region. The sea encroached upon areas which were until then dry land. Eruptions of lava and erosion of the surface were replaced by deposition of sediments beneath a sea. 

Extensive beds of these were laid down in some areas before others were submerged. Here the 

sediments lapped over lavas and plutonic granites alike, and the waste from them all was combined in one sheet of gravel and coarse sand which now appears as sandstone, conglomerate, 

and quartzite. Some of this waste consists of epidote and jasper, the products of alteration in 

the Linville meta-diabase. It is thus seen that the interval between the Algonkian and Cumbrian was at least long enough to permit dynamic movements and chemical changes to effect 

considerable results, even before the period of erosion and reduction began. 

The two sequences generally do not occur in their original relations, which are 

therefore indeterminate over wide areas. The Ocoee of Safford is usually overthrust from the east upon younger strata to an extent which obliterates the normal 
90 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

sequence. An exception to this general fact occurs in northeastern Tennessee, 

where a complete conformable sequence from Safford's Ocoee into the fossiliferous 

Cambrian has been worked out by Keith. (See section, Greeneville and Roan 

Mountain •quadrangles, pp. 95-96.) The discovery of Carboniferous plants near 

Mosely (now Erin), in Clay County, Ala., in metamorphosed rocks which have been 

regarded as a part of Safford's Ocoee (see Chapter VIII, p. 363), shows that the 

metamorphic terrane of which his Ocoee there has been considered a part locally 

comprises rocks of various ages. 

The fossiliferous Cambrian formations of Tennessee range from Lower Cambrian (Georgian) up through the entire system and pass into Lower Ordovician 

in the Knox dolomite. Beneath the fossiliferous strata occur others which have 

no fossils but which are conformable to those that have. The strata vary along 

the valley from southwest to northeast and more markedly across the valley from 

southeast to northwest. Some typical sequences are as follows: 

Generalized section west of Southern Railway. 424a 

d. Formation. Thickness Character of rocks. (feet). Perio 

- . 

I Chickamauga limestone. 1,800-2,100 Blue flaggy limestone with some mottled, earthy beds. 

- ------- ---------- "" ----

Knox dolomite. 3,800-4,200 

Magnesian limestone, white, gray, or light blue; generally 

granular and massively bedded, containing nodules and 

layers of chert. 

- -·· ···--

Blue seamy limestone. 

Conasauga shale. 500-1,600 Greenish clay shale. 

Thin beds of oolitic limestone. 

-- ··-· --·· 

Rome formation. 1,800-2,600 Greenish or brown shale with thin siliceous layers. 

(Rome sandstone.) Purple, brown, and white sandstone interbedded with sandy 

shale. 

.. - --------- -· ----

Apison shale. I 1, 500+ Sandy shale or clay shale in brightly colored bands. 

I --- ---- - ----------- ... 
CAMBRIAN AND LOWER ORDOVICIAN. 91 

General~zed section cast ~f Southern Ra~lway a 

Perwd 

<li 

rl 

Formation 

Chickamauga hmestone 

Kno'- dolomitf' 

Rome formatwn 

(Rome sandstone ) 

Tlncknecs 

(tc'el) 

.~00-650 

4,:wo~,400 

1,100-6,000 

1,600 

(1,100) 

Char<:~ctcr of rock~ 

Blue flaggy limestone 

Magnesian hmestone, white, gray, or hght blue, generally 

granulat and masoiVely lwdded, contammg nodules, layers 

of chert, and beds ot coarse sand 

Blue seamy hmestone 

GICemsh calcareous day shale and beds of hmestone 

?'lnn beds of oolitic lunestone m shale 

Browmsh shale 

Purple, brown, or white s.:mdstone mtCibedcled with sanely 

shale 

1 ~ ~~ Muua_v_sh_a_l_"--------l-----2-0_0_+_1 S<:~ncly shale 

..g <llr-tJ 

~ ~~ j Nebo sand~tone 250-600 \Vhite quartzite or quartzose ~anclstone z ;:$~ c -;::100 --- -----~------1 

f3 S l Nichols shale c 

,_, 

Q) 

:E 

fiJ 

U) Cochtan conglommate 

e. ~ 0 

1t:: 

~ 

w. 

...., Sandsuck shale 

i 1 Stmrs conglomerate 

8 

Sanclsuck shale 

440-1,140 Jl.hcacem{s s<tndy shale 

200-1,500 Quartzite, quartzose sandstone, and conglomerate 

750-1,900 Blue shale, locally calcareous 

0-660 Conglomer<:~te, generally feldspathH· 

Blue shale 

Generalized sectwn west of Chnch and Tennessee nvers 420" 

Peno 

ell 

Formation 

Chick<:~mauga hmestone 

---- --~ 

Knox dolomite 

Cona::.auga shale 

\ 

Rome formation 

(Rome sandstone ) 

Apison shale \ I ---

Tluckness 

(teet) 

1,300-1,700 

-~---

3,300-3,500 

-----

300-500 

2,80()..-3,400 

(1 ,800-2,200) 

1,000+ 

Char:.wter of rock~ 

-

Blue flaggy hmes tone 

-----------

one, white, gr<~y, 01 hght blue, genmally 

n<tSSively bedded, cont<tmmg nodules and 

Magnesian hmest 

granular and I 

layers ot chert 

Blue seamy hmes 

Greem::.h clay sha 

tone 

les 

Thm beds ot ooht IC limestone 

Greemsh or brow n shales wtth thm siliceous l<tyers 

Purple or brown s ancl~tones mterbeclded wrth sanely shales 

\ 
92 

I 

Period.[ 

INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Generalized section southeast of Bays Mountain. 475a 

Formation. Thickness 

(feet). Character of rocks. 

ci 'i I A~~~n: shal:- --~~-l--l-,-OO_O ___ l_,-20-0-- -Li-gh-t--b-l_u_e_c_a_lc-a-re-o:~~~~-e,-b-l-ack calcareous shale. 

·§:~ I~- ~--------~- --1-------1--- -------- --~-----------~~-

~ ~ I Chickamauga limestone. 0-50 Gray argilll}ceous limestone. 

~ I --,.--------~~- ----------:-------------------------------

Knox dolomite. 3,500 Magnesian limestone, white, gray, light and dark blue, with 

nodules of chert. 

---·---------·--------1------------------------ -~-

Nolichucky shale. 450-550 I Yell ow and brown calcareous shale and limestone beds. 

Maryville limestone. 350-550 Massive dark-blue limestone. 

--------------1--------------------- ------~----

Rogersville shale. 180-220 Bright-green clay shales, with a limestone bed. 

------~--------1----~-- --1--------------------------

Rutledge limestone. 350--450 Massive dark-blue limestone. 

1-------------1------1----------~ 

Rome formation. 

Rome formation sandstone. 

250 

500---700 

-------- ------· 

I Red, green, yellow, and brown shales and sandy shales. 

Red, white, and brown sandstones and sandy shales. 

---- --- --------------------1----------------------

Beaver limestone. 300 Massive blue limestone. 

I---------------~{-----2-0_0_ _G_r-ee_n_ argillace-o-us_s_h_a_le~ ---------------

Apison shale. b d h 1 900+ Bright-red, green, and rown san- y s a es. 

500+ Fine white massive sandstone. 

----------------1------11 ______________________ _ 

Murray shale. 300 Grayish-blue sandy shale. 

_N_e_b_o_s_a_n_d-st_o_I_le-.------~----5-0_0 __ l\_I_a-ss_i_v--e-,-~--h-it_e_s_-a_n_d_s-to_n_e-,c--o-ar-se-~~-d-fi-:;---------

-------[----1---------------

Nichols shale. 550-800 Grayish-blue sandy shale. 

-----------~--~--------1--------------------

..., ~ I Cochran conglomerate). 0 . "0. 

1 

i 

II 

600-900 

0-100 

500-700 

Massive white sandstone, coarse and fine. 

Red sandstone, gray sandy shale. 

Coarse eonglomerate, quartz and feldspar pebbles. Q;> .... 

~~ 

sw '-'" Sandsuck shale. 

-------------------- ! ·~~-------~~----~-~~--- ---

1,000+1 Grayish-blue argillaceous shale. 
CAMBRIAN AND LOWER ORDOVICIAN. 93 

Generalized section for the Briceville quadrangle. 47Sa 

~--~-c-~~~~-~~~~~---.~-----------·-·---~-~-----~~--~-~-~--

Period. Formation. 

~ 

.g 

§·u 

·o:; ·:;: Chickamauga limestone. 

w a~ ... 

Thickness 

(feet). 

1,60o-2,000 

Character of rocks. 

Blue and gray limestone, argillaceous limestone, flaggy limestone, and calcareous shale. 

Blue and gray massive limestone with a few nodules of black 

chert. 

3 1-~~~~-~------1-~~~~~-j-~~~~~~~~--------- ----· ·---~~ 

0 

Knox dolomite. 

Conasauga shale: 

{

Nolichucky shale. 

:\faryville limestone. 

I Rome formation. 

Rome sandstone lentil. 

2,800-3,500 

65Q-800 

(250) 

60Q-800 

Magnesian limestone, white, gray, light blue, and dark blue, 

with nodules of chert. 

Yellow, red, and brown calcareous shale with thin beds of 

limestone, those at the base assuming the importance of a separate formation in the extreme southeast. 

Bright-colored red, green, and brown sandy shale interbedded 

with layers of thin sandstone. 

500+ Red, yellow, and brown sandy shale with thick beds of 

sandstone. 

Generalized section of the sedimentary rocks ~n the Great Valley (Greeneville quadrangle).481a 

--

System. Formation. Thickness Character of rocks. (feet). 

Athens shale. 1,000± Black and bluish-black calcareous shale. 

-~ I Moccasin limestone. 450-500 Red, blue, gray, and drab massh::e and shaly limestone. u I ·:;: 

0 I 

'"0 I Chickamauga limestone. o-450 Blue and gray limestone, shaly in part, and variegated ... 

0 ! marble. 

! 

' Knox dolomite. 

Magnesian limestone, light and dark blue, white, and gray, -?-' 3,000-3,500 with nodules and layers of chert and a few beds of cal- . I careous sandstone. 

I Nolichucky shale. 50Q-750 Yellow, green, and brown calcareous shale, with limestone 

beds. 

I 

! MMeivo d"k-bhw •ed d"k-gmy JimO<Wne. i ai 

>.i I Maryville limestone. l'i 700-950 I 0 " ' 

...., ·.: ! "' Cl ----- -- ,1:0 

~ I I 

s i Rogersville shale. 180-200 Bright-green clay shales, with thin limestone beds. " (..) ... 

I 

Cl 

.."! I 

' " 

I 

I l'i 

0 Rutledge limestone. 400-450 Massive dark-blue limestone, with shale beds at bottom. 

::q I 

--

I 

Rome formation. 200± Red, green, and brown shale and sandy shale. 

Sandstone len til. 400±1 Red, white, and brown sandstone and sandy shale. 

-
94 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Generalized 8ection for portion of Rristol quadrangle 8outh of Clinch .1.lfountain. a 

Period. i Formation. Thic~nc:-:s 

(feet). Character of rock~. 

----··- ----------

Athens shale. I 

I 

1,000-1,200 

Sandy shtlle and thin sandstones, with occasional beds of 

impure limestone and limestone conglomerate. 

Dark argillaceous shale at the base. 

··---·· ---····-·· ·1----------------------

Knox dolomite. 1 

I 

Nolichucky shale. 

2,800--3,500 

0-300 

Blne and gray limestone. Very cherty along Walker 

Mountain, but farther toward the southeast the chert disappears and the formation merges with and becomes indistinguishable from the Honaker limestone beneath, and 

the whole is called the Shenandoah limestone. 

Blue calcareous and sandy shale. Toward the east this 

changes to limestone. 

1-----------_J __ ·---------------------------------

Honaker limestone. 

Blue and gray limestone. . Toward the east this formation 

merges with the Knox dolomite and the whole is known as the Shenandoah limestone. 

Russell formation. 400+ Heel and green shales and thin-bedded sandstones. 

The development of the Ocoee group in part of eastern Tennessee and North 

Carolina is shown in the following six sections, which represent the group from 

southeastern to northeastern Tennessee: 

Period. 

Generalized 8Cction east of Bean8 Ummtain. 421 a 

Formation. 

Thunderhead conglomerate. 

Thumlerhea<l slate. 

Thunderhead conglomerate. 

Pigeon slate. 

Character of rocks. 

I 

j Thickness 

I 

(feet). 

------··-----·· -·-·--···--·--··--

300±1 Massh·e conglomerate interbedded with black slate. 

1,500± Black slate, \vith beds of conglomerate and sandstone, generally schistose. 

S00-1,000 Massive conglomerate of blue quartz and feldspar. 

(?) Blue or black slate, with local beds of sandstone aml conglomerate, generally schistose. 

1------·-------l------l-------------------------

l Citico conglomerate. 500-1,100 

Wilhite slate. (?) 

Conglomerate and sandstone, with beds of sandy shale. 

Blue slate with lenses ·of quartz conglomerate, sandy lin-:estone, and limestone conglomerate. 
CAMBRIAN. AND LOWER ORDOVICIAN. 95 

Generalized section southeast of Chilhowee lJ.f ountain. 475a 

-----

I 

.J Formation. Thickness Character of rocks. (feet). Period 

I 

- -------------- -- -·--

I Clingman conglomerate. 1,000+ Gray sandstone and coarse and fine conglomerate, with blue 

quartz and feldspar. 

i--- --- ----- -----

I llazel slate. G00-800 Black slate, with small beds of sandstone and fine conglomi ! erate. 

--------- ----------

I 

! Thunder Head conglomerate. 3,000+ Gray sandstone ;3.nd coarse and fine conglomerate, with blue I 

! quartz and feldspar. 

I I - - ---- ---- ------ -- -~- ------

i 

I Gray sandstone and fine conglomerate, with many beds of Cades conglomerate. 2,400+ sandy slate. 1--------------1------

Banded gray and bluish-gray slate and sandy slate; a few ! Pigeon slate. 1,300-1,700 gra y sandstone beds. 

-----------------------------------------

C'itico conglomerate. 50-800 

Coarse quartz conglomerate. 

Fine quartz conglomerate. 

Coarse white sandstone. 

Fine white sandstone. 

Wilhite slate. O-l,OOO I Limestone conglomerates and sandy limestone. 

Bluish-black argillaceous and calcareous slate. 

I 

Generalized section of the sedimentary rocl.·s in the Bald lJ.fountains, Oreenerille quw?rangle. 481 a 

System. Formation. Thicknef's 

(feet). 

---1--~---------- -- -- -----

~il 0 o Shady limestone. >=:il:i 

. 1,000± 

~~ I _______________________ _ / ___ ~ I 

I Hesse quartzite. 

'B 

~ _ Murray slate. 

w 

~ 

-d 

~ 

Nebo quartzite. 

Nichols slate. 

Cochran conglomerate. 

~ Hiwassee slate. w 

0 

"' "' 0 

u 

9.. Snowbird formation. 

i 

I 

I 

I 

I 

! 

I 

i 

I 

I 

I 

I 

I 

' 

I 

I 

Ar- {!-----Unconformity .----1 

c:hean. Granites. I 

----------------

700-800 

- - -

300-400 

200-900 

400-700 

--- -----·-

200-l,GOO 

- --· 

1,200-1,500 

700-2,000 

--

Character of rocks. 

--

Gray, bluish-gray, mottled gray, and white limestone, with 

nodules and masses of chert. 

Massive white quartzite and sandstone. 

Bluish-gray to gray argillaceous and 

with thin sandstone seams. sandy shale and slate, 

:\Iassive white quartzite and sandstone, coarse and fine, with a few layers of sandy shale and reddish sandstone. 

Bluish-gray to gray argillaceous and sandy shale and slate, 

with thin sandstone layers. 

Massive quartz conglomerate and 

gray, with seams of dark slate. 

quartzite, light and dark 

Blue, gray, black, and banded slate, with a little fine mica 

schist. Includes layers of sandstone and conglomerate 

and beds of calcareous sandstone. 

Gray and white feldspathic quartzite and sandstone, with 

dark slate beds. Locally becomes conglomerate and darkpurplish sandstone. 

Coarse and fine quartz conglomerate and arkose. 
96 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Generalized section of the sedimentary rocks of the Roan Mountain quadrangle in the vicinity of 

Erwin.4s4 

~-- ---------,---- --- -- ----- ----------- -- -- ------------- --~------

----

System. Formation. 

I 

Thickness Character of rocks. (feet). 

------- --·-

d Athens shale. 800--1,600 Black and bluish-black calcareous shale below, blue-gra 

"' banded slaty shale above. 

:g 

y 

?-

0 

'"0 

'-< Magnesian limmtone, light and dark blue, white, and gray 0 Knox dolomite. 3,000-3,700 with nodules and layers of chert and a few beds of calca 

--- --- reous sandstone. 

' 

Nolichucky shale. I 50-600 Yellow, green,. and brown calcareous shale with limeston 

beds. e 

I 

I 

Honaker limestone. 1,800-2,200 Massive dark-blue 

blue limestones. 

and dark-gray limestone. White an d 

----- ----

Purplish, red, green, and variegated shales, sandy shales 

Watauga shale. 1,000-1,100 and thin sandstones, with calcareous shales and thin blu 

limestones interbedded. e 

Ci' 

.::: 

--~ 

0 . 

E "' ;.:'E 

00 Shady limestone. 750--1,000 Gray, bluish-gray, mottled-gray, and white limestone, wit '-' 

~ ~11:1 nodules and masses of chert. .,.., ~"' <ll- ...._.rn 

h 

.-;:; 

"' t: Hesse quartzite. 

I 

700--1,000 Massive white quartzite and sandstones. 

"' ;:::; 

cr '"0 

I 

<ll ,., Bluish-gray to gray argillaceous and sandy shale and slate "' 0 en 

<ll 11:1 Murray slate. 300---400 "' with thin sandstone seams. ~ rn 0 ..,.., I 

+" 0 

"' I <ll ;:::; C) Massive white quartzite and sandstone, coarse and fine, wit 0 i:< N ebo quartzite. 

I 

200--900 .... 

C) 0 layers of sandy shale, slate, and reddish sandstone . 

s ;:S 

"' :a 

I 

en 

~ 2. 

Nichols slate. 400-700 Bluish-gray to gray argillaceous and sandy shale and slate 

" I with thin sandstone layers. 

"' 

h 

·.: 

,.0 

--~ s 0 . 

"' "''"0 Massive quartzite, sandstone, and conglomerate, white o 0 ~s Cochran conglomerate. 200-1,600 '-'11:1 gray, with seams of dark slate. 

e_r]3 - i 

Hiwassee slate. I 300-1,500 Bluish-gray to black and banded slates, with a little fine mic 

I 

schist. Includes layers of sandstone and conglomerate. 

r 

a 

--- ---------------

I Gray and white feldspathic quartzite and sandstone, wit 

Snowbird formation (amygda- ] 700--2,000 dark slate beds and lentils of amygdaloid. Locally be 

loid). 1 comes conglomerate and dark-purplish sandstone. Fin 

I 

quartz conglomerate and arkose at base. 

h 

e 

--- ---

~ 

'--'"' Granites. <.3 '-' -----------
CAMBRIAN AND LOWER ORDOVICIAN". 97 

·Generalized section of the sedimentary rocks of the Cranberry g_uadrangle. 480a . 

Period. Formation. 

--------- ---

Watauga shale. 

-------

Shady limestone. 

Erwin quartzite. 

----

Hampton shale. 

----

1 Unicoi fo=atian. 

- ---Unconformity. 

Gneisses, granites, and ancient 

volcanic rocks. 

Thickness 

(feet). 

1,000-1,100 

I 

i 

I 

Character of rocks. 

Purplish, reddish-brown, and yellow shales, sandy shales 

and thin sandstones. with calcareous shales and thin blu e limestones interbedded. 

750-800 1 

Gray, blui3h-gray, and mottled-gray limestone, with nodule 

and masses of black chert. 8 

500-700 I 2\iassive white ~uartzite ~~ds~ndstone. 

' 

600-SOO I Blui~h-gray and gray argillaceous and sandy shales, wit 

f thm sandstone layers. 

h 

I ---

I 

Massive white sandstone, feldspathic sandstone, and quartz 

ite, with interbedded shales and sandy shales in the uppe 

1,500-2,500 part, a thin bed of amygdaloid near the middle, and con glomerate, arkose, and graywacke in the lower part. 

r 

-- --------------------------- ----------- ---~~-

Generalized section of the sedimentary rocks of the Mount _;_vfitcheZZ g_uadrangle. 482 

----

1 System.; Formation. 

--------

Shad y marble. 

--------

n quartzite. 

pton shale. 

----· --

ard schist. 

Unconformity.~--~~ sses and granites. I 

·~~~ BreY 0 8 

8~ i £w' ---

~ § Gnei ~"' "5 I 

I ---

---------

Thickness Character of rocks. (feet). 

-- --- ---

600+ White and blue massive banded marble. 

600+ Massive white quartzite. 

Blue and gray shale and slate. 

1,000+ Fine-grained black schist, in pbces graphitic. 

---··--

------------
98 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

A somewhat different development of Safford's Ocoee group is found in extreme 

southwestern North Carolina, as shown by the' following section: 

Generalized section of the sedimentary rocks of the Nantahala quadrangle. 483 

---------- --------

I 

System. j Formation. Thickness 

(feet). Character of rocks. 

4-< 

0 

0 

0 

0 

(.) 

£ 

I -------------

·I_ Nottely quartzite. ___ _ 

I ,~ndrews sc~st. 

I Murphy marble. 

Valleytown formation. 

I 

I 

150+I Fine white quartzite. 

I 

:?00-350 I Light-colored calcareous schist with ottrelite and iron ore. 

I 

150_500 I Thick-bedded white, blue, and blue and white banded mar- l ble. --- __ ! _____________________ _ 

ij' Graywacke and fine-grained gneiss, interbedded with dark 

garnet and ottrelite schists. 900-1,200 

Brasstown schist. I 1,200-1,500 

1

1

' Blue and black banded ottrelite schist, garnet schist, and 

slates, with a few layers of fine graywacke. Black slate 

usually at the base. 

------------ ~--

. • • I <:> 0_500 I Coarse and fine white quartzite with some quartz conglom- 1 Tusqmtee quartzite. I - 1 crate. 

I -- ------~~-- -- -~ Black, bluish-black, and gray slate; in places altered to fine 

I Nantahala slate. 1,

400_1,800 black schist with some fine ottrelite and garnet. Contains 

I 

a few beds of gray sandstone and graywacke. Thick bed j of staurolite-garnet schist usually at the base. I ------------1 

Great Smoky conglomerate. I 5,500-6,000 

Blue quartz and feldspar conglomerate.· Massive beds of 

quartz and feldspar conglomerate and coarse gray sandstone with beds and seams of black slate. Altered toward 

the southeast into coarse and fine graywacke and quartzite 

with beds of black schist and ottrelite schist. 

I Hiw~~see :late. ----- 500 Blue and gray banded slate. 

- -,-·----Unconformity.----

~ 

1J " 

1

. Gneisses and granite. 

B 

~ 

Light-gray granite, fine granite, and gneissoid granite. 

J 11-12. CALIFORNIA, NEVADA, AND UTAH. 

In 1890, with reference to the Great Basin province in general, Walcott 851 

summed up the Cambrian stratigraphy as follows: 

In this province there appears to have been a large accumulation of more or less coarse, 

arenaceous sediment, commingled with considerable argillaceous material, before the deposition 

of the sediments of the Olenellus zone. As far as shown, the Olenellus fauna appeared at the 

time the character of the sediments was changing to finer sands and argillaceous clays, and 

then to calcareous clays. The sedimentation is unlike that of the sections on the eastern side 

of the continent. The southern portion of the province is found in the Great Basin region of 

Utah and Nevada, between the Wasatch range and the Sierra Nevada range. In the eastern 

or Wasatch area Lingu[l]ella ella, Olenellus gilberti, and Cruziana sp.? occur in a thin band of 

fine micaceous sandstone, about 200 feet from the summit of the Cambrian rocks, which are 

conformably subjacent to strata of Ordovician age. The Olenellus-bearing sandstones are 

covered with trails of annelids, etc., and are evidently a littoral or shore deposit. 
CAMBRIAN AND LOWER ORDOVICIAN. 99 

In the Eureka district of central Nevada the fauna is confined to a narrow belt of arenaceocs 

shales, with some intercalated limestone. The fauna consists of but seven species: Girvanella? sp. ?, Kutorgina prospectensis, Scenella canula, Olenellus gilberti, 0. iddingsi, Olenoides 

quadriceps, Ptychoparia subcoronata, and Anomocare parvum. Of these, two species, Olenoides 

quadriceps and Scenella canula, are found 500 feet higher up in the section. In the Highland 

Range section of Nevada the rocks are essentially of the same character as in the Eureka section; 

the two species, Olenellus gilberti and 0. iddingsi, occur in an arenaceous shale associated with 

Cruziana sp.? In the Pioche section more limestone is interbedded in the arenaceous shale 

and the fauna of the Olenellus zone is larger. It includes Eocystites??, Lingulella ella, Kutorgina pannula, Acrothele subsidua, Acrotreta gemma, Orthis highlandensis, Olenellus gilberti, 

Zacanthoides levis, Orepicephalus augusta, C. liliana, and Oryctocephalus primus. Of these, 

Kutorgina pannula, Acrothele subsidua, Acrotreta gemma, and Hyolithes billingsi pass to the 

zone above that carrying Olenellus. In limestones of the Olenellus zone at Silver Peak, in 

western Nevada, the following species were collected by Mr. Clayton: Girvanella? sp.?, Spirocyathus atlanticus, Ethmophyllum meeki, E. whitneyi, Kutorgina cingulata, Hyolithes princeps, 

Olenellus gilberti. 

Detailed sections are given in a bulletin by Walcott 848 published in 1886. In 

1895 Walcott 836 stated: 

The only Lower Cambrian rocks of California known to me occur in the White Mountain 

Range of Inyo County, east of Owens Valley, with the single exception of one small mass west 

of Big Pine, which is in the foothills of the Sierra Nevada. 

* * * * * * * * * 

During the summer of 1894, accompanied by Mr. F. B. Weeks, I crossed the range over 

the toll road leading from Big Pine to Piper's ranch, in Fish Lake valley, and penetrated into 

it from the western side in Waucobi, Black, and Silver canyons. 

The ascending section exposed in the ridge on the north side of Black Canyon is as follows: 

Feet. 

1. Gray and yellowish arenaceous limestone, occurring in low hills above the Quaternary_.... 200 

2. Massive-bedded compact fine-grained, often saccharoidal light-gray siliceous and arenaceous limestone (strike N. 10° W. (mag.), dip 20° E.). At 100 feet from base ofthis division a dike of basalt 40 feet in thickness cuts through and displaces the limestone in the 

vicinity of the dike, so as to give it a dip of from 70° to 80° E. Above the dike the dip 

of 20° is very quickly resumed. At 160 feet from the base a band of white limestone 

occurs, which contains numerous small concretions of limestone. At 230 feet above the 

dike occurs a band of shaly limestone, which has buff-colored partings; and irregular, 

buff-colored, sandy laminations occur in thin layers in the thick-bedded limestone. 

No.2 may be subdivided as follows: 

a. Light-gray and white limestone ................................. _ ............ 500 

h. Buff and gray, more arenaceous limestone, with a band of cherty limestone 20 to 

25 feet thick at 125 feet from its base ................................ __ . . . . . . 170 

c. Gray arenaceous limestone, cherty at top ..................................... 115 

d. Shaly and thick-bedded sandy limestone, cross-bedded in places, with yellowishbuff layers, also with two bands of brown thick-bedded and shaly quartzite .. 145 

e. Massive-bedded coarse arenaceous gray limestone, passing into buff-colored and 

cherty beds above. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 

f. Buff-colored shaly limestone ............................................ __ ..... 5 

g. Bluish-gray banded limestone .. _ ....... _ ...................... _ ......... _.... 30 

h. Gray arenaceous limestone, with hands of huff-colored, mostly thick-bedded 

limestone .... _.......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 

i. Thick-bedded bluish-gray limestone......................................... 10 

j. Brownish and buff-colored calcareous sandstone, with inclosed brecciated thinbedded brown sandstone................................................... 5 

k. Dark banded quartzite....................................................... 30 

1. Massive-bedded gray arenaceous limestone .................................... 225 

~ 1,525 

3. Dark irregular thin-bedded siliceous slates with interbedded dark quartzitic sandstone (dip 

25°-30° E. (mag.), strike north and south)............................................. 635 

The section is terminated at this point by a fault line. 
100 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

On the north side of Silver Canyon, No.3 is well exposed and is estimated to have a thickness of 2,000 feet. Above this a series of limestones and calcarem~s and siliceous shales 

occurs and some interbedded dark quartzitic sandstones, that extend upward 1,000feet. Near 

the base a massive-bedded limestone 100 feet in thickness occurs, in which great quantities of 

Lower Cambrian corals (Archreocyathinre) occur. This series is capped by about 200 feet of 

compact thin-bedded arenaceous argillite, with interbedded layers of dark-brown fine-grained 

quartzite. 

The entire section, briefly summarized from summit downward, is as follows: 

4. Upper arenaceous beds. __ ......... _· __ ...... _ .. _____ . ____ .......................... ___ _ 

3. Alternating limestones and shales .............. _____ ........ _ .... __ ._. _____ . __ ........ . 

2. Siliceous slates and quartzites .. __ . _______________________ ................... _ .. _______ _ 

1. Siliceous limestones .............. ____ . ___ ... _ ... __ .................... _ .... _______ .... . 

Feet. 

200 

1,000 

2,000 

1,700 

4,900 

In round numbers the section exposed in the ''Vhite Mountain Range, between White Mountain Peak and Waucobi Canyon, is 5,000 feet in thickness. 

No fossils were found in the lower limestone. Numerous annelid trails occur in the lower 

siliceous series, and in the slaty portion near the summit heads of Olenellus were found. In 

places the lower portion of the upper limestone series is almost a solid bed of different forms 

of the Archreocyathinre. Ethmophyllum whitneyi Meek is very abundant, and the genera Protopharetra, Coscinocyathus, and probably Archreocyathus occur. Ethmophyllum ranges 

throughout the limestone series into the base of the shales in Tollgate Canyon, where it is associated with cystidean plates and fragments of Olenellus. On the north side of Silver Canyon 

the Archreocyathinre are so abundant in the limestone that it may practically be called a Lower 

Cambrian coral reef. This reef was traced for nearly 30 miles, and the same types are also 

known to occur in the Silver Peak Range, about 25 miles to the eastward. 

So far as known to me, this is the oldest of the Cambrian faunas known in the western 

portion of the United States. Just what its relations to the Olenellus fauna of central Nevada 

and British Columbia are I am unable at present to state, except that I believe it to be older 

than the Olenellus fauna of central Nevada. 

It is not impossible that a fauna will be found in the lower limestone, but in the hasty 

reconnaissance in which I was engaged only a portion of one day was given to the examination 

and measurement of the section. I hope in the future to extend the study of the White Mountain 

Range, as Mr. Fairbanks has written me that he has discovered Fusilina cylindrica in the southern 

end of the range, east of Keeler, which is about 50 miles south of Tollgate Canyon. If the 

section is unbroken, the Middle and Upper Cambrian and Ordovician faunas should be found 

before reaching the Carboniferous horizon discovered by Mr. Fairbanks. 

In recent papers WalcottE61 has supplemented the data regarding the earliest 

Cambrian stratigraphy and faunas as follows: · 

The oldest known Cambrian fossils are found deep down in the Lower CambriarL strata 

of southwestern Nevada and the adjoining Inyo County area of eastern California. In sections 

120 miles apart the Lower Cambrian has a thickness of over 5,000 feet, with a great limestone 

forming the upper 700 to 2,000 feet. Below this limestone calcareous strata occur, but the 

predominating rocks are sandstones and arenaceous, siliceous, and calcareous shales. In the 

lower 400 feet of the Waucoba Springs section and the Barn•l Spring section south of Silver 

Peak in western Nevada the fauna includesAnnelid trails. 

Protopharetra sp. undt. 

Arch:oeocyathus sp. undt. 

Ethmophyllum cf. whitneyi :Meek. 

Mickwitzia occidens Walcott. 

Trematobolus excelsis Walcott. 

Obolella sp. undt. 

Orthotheca sp. undt, 

Holmia rowei n. sp. 

Holmia weeksi n. sp, 
CAMBRIAN AND LOWER ORDOVICIAN. 101 

Although this fauna, according to our present knowledge, is the oldest known Cambrian 

fauna, it includes representatives of the several classes of invertebrates which I will enumerate. 

Actinozoa.-The corals are represented by a very primitive form of Protopharetra, a small 

form of cup-shaped Arch:::eocyathus, and a small Ethmophyllum closely allied if not identical 

with Ethmophyllum whitneyi (Meek), which occurs higher in the section. The latter is not a 

notably simple or primitive form of the Arch:::eocyathin:::e; on the contrary, it is nearly as far 

advanced as any species known in the Cambrian. 

Vermes.-The annelid borings and trails that occur in and on the sandstones and shales 

are much like those of the Middle and Upper Cambrian. 

Molluscoidea.-The two species of brachiopods represent widely separated genera. Mickwitzia accidens Walcott is one of the primitive forms of the Paterinidre, while Trematobolus 

excelsis Walcott is a typical form of the Siphonotretid:::e. The interval represented by the 

relative development of Mickwitzia and Trematobolus is sufficient to convince us that we must 

look far back in Cambrian or it mey be pre-Cambrian time for the progenitors of the inarticulate 

brachiopods. 

Pteropoda.-The forms representing Orthotheca are abundant, large, strong, and evidently 

as well developed as those of the Middle Cambrian. 

Crustaceans.--'-The trilobites thus far found at this horizon are confined to two species of 

the genus Holmia. One of them, Holmia weeksi n. sp., has many segments and is more primitive 

than such forms as Olenellus thompsoni Hall and Holmia brogger'i (Walcott), of the upper portions 

of the Lower Cambrian sectio:p.. The other species, Holmia rowei n. sp., is of the same general 

type as Holm'ia broggeri. The absence of all other trilobite genera is the most marked feature 

o.f this early Cambrian fauna. 

In the section 100 miles to the south, at Resting Springs, Inyo County, Cal., a brachiopod 

closely related to Billingsella highlandensis WalCott occurs 2,800 feet below the upper limestone 

in association with the trilobite Holmia rowei. 

Comparing the species in the early Lower Cambrian fauna with the Olenellus fauna, in 

strata 5,000 feet higher in the section, we find a marked advance in the variety of the later 

fauna, but we do not know how much of this may be due to the absence, from our collections, 

of genera and species that may have existed during the deposition of the earlier sediments. 

In the earlier fauna of the Waucoba section the class characters of the Arthropoda, Mollusca, 

Molluscoidea, Vermes, and Cmlenterata were developed, and while the study of the genera and 

species adds a little more to our knowledge of the rate of convergence backward in geologic 

time of the lines representing the evolution of animal life, it, at the same time, proves that a 

very long time interval elapsed between the beginnings of life and the epoch represented by the 

Olenellus fauna. 

This fauna is described by Walcott, 860 in the Smithsonian Miscellaneous Collections. In his latest contribution Walcott 862 says: 

The evidence a:O'orded by the few traces of pre-Cambrian fossils is inconclusive as far as 

determining whether their habitat was in marine, brackish, or fresh water. 

The fossils from the Chuar group of Arizona are not sufficiently characterized to prove 

their origin or habitat. The protozoan Cryptozoon? occidentale Dawson is very abundant in 

Arizona, also in the Belt series of ::\fontana, Alberta, and British Columbia. It occurs in limestones similar to those deposited in the fresh-water lagoons of Florida, and similar to the limestones of the lake deposits of the Tertiary formations of the Great Plains region of North America. 

The fossils of the Beltina zone of Montana and Alberta could as readily have been developed 

in fresh or brackish waters. There is nothing about the crustacean remains incompatible 

with their living in fresh water, in fact, the fragments indicate a form more nearly related to 

the fresh-water Brachiopoda with very thin test, rather than the strong ::\Ierostome (Eurypterus, etc.). 
102 INDEX TO THE STRATIGRAPHY OF NORTH Al\fERICA. 

The oldest Cambrian fauna now known, with Nevadia weelcsi and Ilolrnia rowei, is limited 

to a few forms, but with a careful examination of the region where it occurs in southwestern 

Nevada it is highly probable that a considerable fauna will be found. The strata in which 

it occurs were deposited in a depression opening out toward the Pacific Ocean, where southwestern California is now located; this depression soon extended northward and presumably 

connected through to British Columbia and Alberta, as the same species of Olenellus occur 

in the central and upper portions of the Lower Cambrian both in Nevada and Alberta. 

I do not know of a Cambrian fauna as old as that of Nevadia, weelcsi on the eastern side of 

the continent, or on the European continent. It appears to be a portion of the older fauna 

that is missing everywhere except in southwestern Nevada. I think it was brought in by 

the advancing Lower Cambrian sea from a sea to the west, the sediments of which are buried 

beneath later strata or are off the present shore line of the continent beneath the sea. 

The theory that life originated and developed in fresh-water ponds and lakes does not 

appeal to me. More uniform conditions of temperature and environment would be present 

in the ocean and the sediments of the fresh-water deposits of pre-Cambrian and Cambrian 

time, if such exist, do not show sufficient evidence of life having existed at tho time of their 

deposition. Tho Algonkian fossils of the Belt and Grand Canyon series (Walcott, 1899, pp. 

227-239) probably came from the marine fauna when a temporary connection existed between 

the interior fresh or brackish water lakes and the ocean. 

Spurr 772 gathered in one volume the observations made by himself and others 

on the occurrences of Cambrian strata and faunas in 25 widely distributed ranges 

of the Great Basin. Ball 54 supplemented Spurr's descriptions for southwestern 

Kevada and eastern California and gave a columnar section showing the relations 

of the Paleozoic strata among themselves and to the post-Carboniferous and 

Tertiary igneous rocks. 

Darton 243 has noted the occurrence of Cambrian strata resting on older granite 

at Iron Mountain, in eastern San Bernardino County, Cal. He observed 1,200 

feet of shale and limestone with quartzite at the base and collected "fragments 

of trilobites and mollusks which proved not to be specifically determinable," but 

which according to 'Walcott are "undoubtedly Cambrian, probably Middle 

Cambrian." 

J 13. COLORADO. 

The Upper Cambrian is represented in southwestern Colorado in Animas 

Valley by the Ignacio quartzite, a basal deposit, unconformable on the Algonkian. 

Cross 188 describes the Ignacio as follows: 

The lowest lithologic division of tho Paleozoic section in the Animas Valley is made up 

of quartzites and·varies in thickness, in the area thus far examined, from a few feet to 200 

feet. In layers near the middle of these quartzites a single generically determinable shell 

has been found. From the stratigraphic relations and the evidenCB of this fossil it is assumed 

that in this region the Cambrian system is represented only by a thin series of quartzites belonging probably to its upper division, and for those the name Ignacio formation .or quartzite is 

proposed, from the lakes in the Animas Valley about 18 miles west of south from Silverton, 

near which the formation is well exposed. It is at present believed that all of the Paleozoic 

quartzites beneath the "Salt shales" belong to the Ignacio. 

The Ignacio consists of nearly pure siliceous strata, with some feldspar locally in the 

lowest beds. The greater part is fine grained, white, gray, or pinkish, and highly indurated. 

The lower portion is commonly a massive quartzite of prevalent pink or reddish color, while 

the succeeding strata are nearly white. Di<ltinct bedding is common, as is :=tn irregular jointing. 
CAMBRIAN AND LOWER ORDOVICIAN. 103 

Above this the strata are often wavy in bedding, with shale partings, in which mud cracks, 

trails, and other markings are common. These layers are friable sandstones in places. More 

massive quartzite layers generally succeed this series, but not in a thickness equal to those 

below. 

At the very base of the formation a true basal conglomerate is often found but only in 

hollows of the granite, schist, or Algonkian quartzite floor. The hard Algonkian quartzites 

are most abundant among the pebbles, which range in size up to a diameter of (rarely) 1 foot. 

The only identifiable fossil invertebrate yet obtained from the Ignacio beds was found 

on a remnant capping Overlook Point, one of the hills of Mountain View Crest, in the Needle 

Mountains quadrangle, south of Needle Creek. Specimens of this fossil were found scattered 

through a hard, dark quartzite above the middle of the formation, which was there 110 feet 

thick. Mr. Walcott identifies this shell as an Obolus but is unable, from the material at hand, 

to determine its species. Three forms that are much like this are Obolus matinalis, 0. tetonensis, 

and 0. loperi, the latter occurring in the passage beds between the Cambrian and the Ordovician in the Crested Butte quadrangle, Colorado. Since the Cambrian is known in Colorado 

only in thin representatives of the upper division, it seems best to assume for the present that 

the Ignacio quartzite also belongs in that series. 

A common apparent fossil of the Ignacio is thought by l\h. Waleott to be Cruziana, a 

problematic plant remain. 

J 15. MISSOURI AND NORTHERN ARKANSAS. 

The "Magnesian Limestone series' ' of Missouri is thus described m general 

terms by Broadhead: 98 

The chief rocks of t1w Ozark Plateau include a series of magnesian limestones and sandstones amounting to 1,000 feet in thickness. In 1891 I applied to these rocks the name "Ozark 

series." The lower one-hal£ to two-thirds may be Cambrian, including rocks of the age of the 

Potsdam of Kew York. The upper portion may be the equivalent of Dana's Canadian, or 

tl1e lower part of the Lower Silurian. The evidence shows that the life of the Cambrian sea 

in Missouri was limited to but a few species. We find a few Orthocerata, a Lituite, a small 

Orthis, a Pleurotomaria, a Maclurea, two species of Ophileta, two or three species of Straparollus, 

probably two species of :Murchiso-nia, an Obolella, three or four species of trilobites, while in 

t'w Potsdam of Wisconsin and Minnesota several other trilobites may be found. Where the 

waters were shallow sea worms lived and left their track in irregular windings in the rocks. 

In the later seas seaweeds abounded, as· shown by certain beds of the Second Magnesian limestone. That the Ozark series was subject to erosions and slight elevations and depressions is 

shown by the occasional appearance of a few feet of sandstone at intervals of a few feet to 

over a hundred. Near the close of the Ozark terrane it is probable that a large area oi the 

plateau was elevated above water. 

The -general stratigraphy is stated as follows by the same authority: 

Feet. 

Trenton limestone ................ _ ........................................................................................................ .. 

First Magnesian limestone ......................................................................................... _ .. ____ .. __ .. ____ .. 100 

First or St. Peters (saccharoidal) sandstone ... __ .. _ .. __ ..... __________ . _______ .. ____________ .. _ .. _ 130 

Second l\Iagnesian limestone ....... __ .. ____ .. ______________ .. ______________________ .. __________ 200 

Second sandstone. __ .. _ .. ________ .. ______ .. _ .. ______________________ .. ________ .. _____ .. _ .. ______ 125 

Third ~Iagnesian limestone _____ .. ________ .... _ .. _ .. _____________ .. _________ .. ___ .. _______ .. _ .. _ _ _ _ 300 

Lower l\Iagnesian limestone and sandstone .... ____ .. _ .. _____ .. _ .. _____ .. _ .. _______ .. ____ ........ _ .. _ _ _ _ 300 

1,155 

Several classifications of this series of rocks have been proposed, but the variable character and lenticular form of many of the formations or members have 
104 INDEX TO THE STRATIGRAPHY OF NORTH k\1ERICA. 

rendered generalization difficult. A systematic study of the whole area was made 

in 1905 by Ulrich, 52 who arranges the formations as follows: 

Classification and syrionymy oftheformations of the" ]{agnesian" or "Ozark series" in .Missouri. 

Sys- Series. Formation. Thickness Synonyms. tern. (feet). 

-

Joachim limestone. 0-150 First Magnesian limestone. 

Folley limestone.a 

--

First or Sa~charoidal sandstone. 

St. Peter ("Crystal City") 0-200 Cap-au-Gres sandstone. 

sandstone. Pacific sandstone. 

0~ "Key sandstone" in Yellville district of Arkansa~. 

(..) -- -- '~-

·~ 

0 Second Magnesian limestone. '"0 

... Jefferson City limestone. 50-250 Winfield limestone . 0 d Finley limestone.b . ;:l P.. ?Marshfield sandstone . .;:; ~ :> 0 0 bb '"0 

... ~ Second sandstone . 0 Moreau sandstone. ... :E "' Roubidoux formation. St. Elizabeth formation and Bolin Creek sandstone IS: al 70-225+ --· ? --- 0 ~ member. ....< ?Marshfield sandstone . '"0 ... ?Bolivar sandstone. .::: 0 

"' •.-< 

U1 

.::: 0 .,_, 

"' 0 M 

0 fl.< Third and Fourth Magnesian limestones and Third ~ sandstones . ... 

"' Gasconade limestone. Includes Osage limestone; Cole Camp sandstone of w 450-650 Winslow; also Gasconade limestone, Gunter sandstone, and Proctor limestone of Ball and Smith. 

Lesueur limestone. 

d 

.;:1 g ... 

,.0 Basal part of the Potosi limestone and the "Potosi s "'M 

~ Elvins formation. 0 0-120 slates and conglomerates" of Nason. "' ,_...., Q ~:-<S 

w "' ---

g Bonneterre limestone. ?Fourth Magnesian limestone (in part). 

Decaturville li,mestone. 

;.;:; 

"' <1j "'La Motte sandstone. 0-300 Second sandstone of Shumard (in part). 

---

d 

"' "' Granites and porphyries. A 

"' ... 

<1j 

a The names ''Folley limestone," "Cap-au-Gres sandstone," and "'Winfield limestone," together with a number 

of other new names, were published by Keyes in Some geological formations of the Cap-au-Gres uplift: Proc. Iowa. 

Acad. Sci., vol. 5, 1898, pp. 58-63. . b The names "Finley limestone," "Marshfield sandstone," and "Decaturville limestone," appear in a provisional table of geologic formations in Missouri, by Shepard, E. M., Bull. Bradley Geol. Field Sta., 1904, p. 42. 

Ulrich remarks: 

As has already been stated, none of the classifications and subdivisions of the Ozark series 

of rocks, briefly discussed in the foregoing pages, has proved wholly satisfactory. An arrangement that would be above criticism is perhaps impossible. Some of the beds vary so greatly 
CAMBRIAN AND LOWER ORDOVICIAN. 105 

from place to place that it is difficult to follow them over any considerable area. The difficulties 

are greatly enha'llced by the apparent scarcity and imperfect preservation of the fossils and by 

the general similarity in lithologic character exhibited by widely separated beds in the series. 

The occurrence of beds of sandstone at intervals in the mass of magnesian limestones was early 

seized upon as affording a ready means for dividing the series into formations; but experience 

gradually taught that most of the sandstones were mere lenses, irregularly developed at unequal 

intervals and occurring locally as many successive beds or with only two or three. In the 

northern and central parts of the Ozark Plateau the sandstone beds seem to be more regularly 

developed than elsewhere, and here they are of considerable use in working out the stratigraphy. 

Along the southern border, however, only the First or St. Peter sandstone seems to have been so 

well developed as to mark a definite horizon. Along the eastern border, especially in Ste. 

Genevieve County, the upper half of the series is thicker than usual. It here contains so many 

beds of sandstone that it is very difficult to establish the boundary line between the Gasconade 

and Roubidoux formations and between the latter and the overlying Jefferson City limestone. 

A careful study of the cherts has yielded perhaps the most reliable of the lithologic criteria 

employed in discriminating the three formations of the Potosi group.. As this group covers 

by far the greatest part of the Ozark area, the opportunities for studying and testing the value of 

certain varieties of chert as indices of particular horizons are unusual. Having checked the 

results in many instances by evidence afforded by fossils, which really are much commonor in 

these rocks than is generally believed, we have gradually become convinced that the story as told 

by the cherts is rarely at fault. The mere presence of considerable quantities of chert is at once 

reliably indicative of the Potosi group, the underlying limestones being practically free from it, 

as is true also of the Joachim limestone at the top of the series. It is to be remembered, however, 

that the proportion of chert in a given bed may vary greatly in near-by exposures. This is shown 

often very strikingly in opposite faces of a hill, the one side of which forms a bluff, the other a 

gentle, soil-covered slope. In cases of bluff exposure, where side erosion is active and takes 

place under conditions very different from those prevailing on gentle slopes, the limestone beds 

may often .seem to be almost entirely without chert, but on the other side of the hill the surface 

may be thickly strewn with it. 

The classification presented in tabular form on page 104 is based upon more or less extended 

investigations in all parts of the field. The formations are discriminated chiefly by lithologic 

·differences and limited in most cases by at least local stratigraphic discordances. As the formations are intended to express as much as possible lithologic units deemed worthy of being 

mapped separately, the evidence of the fossils found in them was accorded secondary rank. 

However, in the determination of the age of the deposit the faunas were depended upon almost 

exclusively. 

It will be observed that the division between the Ordovician and Cambrian is drawn as a 

dotted line opposite the Roubidoux member of the Potosi. This seeming indecision concerning 

the point at which the line should be drawn is not due to the absence of a fauna, for we have 

succeeded in collecting a large one, but because of the conflicting elements contained in it. The 

trilobites from the Gasconade and the lower part of the Roubidoux are, so far as observed, 

nearly all of types that hitherto have been regarded as strictly indicative of the Upper Cambrian. 

On the other hand, the numerous gastropods and fewer brachiopods found in the same beds 

are nearly all of Lower Ordovician types. 

Ulrich 52a also gives detailed descriptions of the formations. 

The latest classification of the rocks of this series is that made by Buckley, 106 

who in 1909 published a paper in which several new names were introduced for the 

rocks lying between the Roubidoux and the Bonneterre. 
106 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

K 12. IDAHO AND UTAH. 

Walcott 859a has recently classified the Cambrian of northeastern Utah and 

southern Idaho. The localities lie in the vicinity of Logan, between Great Salt 

Lake and Bear Lake. The classification below is taken from his paper: 

Cambrian formations cin northeastern rtah and 80Ythern lilaho. 

-------------.------------------------

Formation. Character. 

Thickness (feet). 

Blacksmith 

Fork. 

West of 

Liberty. 

------------- -- --------------------------------1----

Upper Cambrian. 

St. Charles formation........... Bluish to gray arenaceous limestones, with some cherty and 

concretionary layers, passing at the base into thin-bedded 

gray to brown sandstones. 

Middle Cambrian. 

Kounan formation __ . _ . . . . . . . . Light-gray to dark lead-t'olored arenaceous limestones ... __ ... 

Bloomington formation .... __ ... Bluish-gray, Ir_ore or less thin-bedded limestones 2:nd argillaceous shales. Small rounded nodules of calc1te occur 

scattered irregularly through many of the layers of limestone. 

Blacksmith formation ..... __ ... Gray arenaceous limestone in massive layers_ ......... ____ .. 

Ute formation ... _ ...... __ .. _ .. Blue to bluish-gray thin-bedded fine-grained limestones and 

s~ales, with some oolitic, concretionary, and intraformatwnal conglomerate layers. 

Spence shale. _ .. _ .... _ .... ! Argillaceous shales ............. _ ...... _ .............. ____ .. 

Langston formation_ ..... _ ..... ' }fassive-bedded bluish-gray limestone with many round con- cretions. 

Brigham formation ___ .... ___ .. Massive quartzitic sandstones .. _ ....................... __ .. 

I 

1,225 1,197 

1,041 814 

1,320 1,162 

570 23 

759 731 

30 30 

107 30 

1,250+ 1,000+ 

In a recent paper Blackwelder 84b writes as follows regarding the Cambrian 

of northeastern Utah: 

Just below the fossiliferous Cambrian shales and limestones there is a quartzite 1,000 to 

1,500 feet thick. This quartzite rests now on the eroded surface of the Algonkian quartzite and 

slate, and now on the much older gneiss and schist which are generally referred to the Archean. 

Walcott has .named it the Brigham quartzite, but it may be seen most clearly at places such as 

Ogden and \Villard, rather than at Brigham. The oldest fossils found in the shales are referred 

by Walcott to the Lower Cambrian. The Brigham quartzite may therefore be assigned also to 

the early Cambrian and the quartzites and slates beneath the unconformity to the Algonkian. 

There is, however, an alternative view, advocated by Daly and others, that the oldest Cambrian 

faunas in the Rocky Mountains are Middle Cambrian and that the thin Brigham quartzite is 

the same in age; that the unconformity represents a brief time interval and that the great 

quartzite slate series is not Algonkian, but simply early Cambrian. Critical studies over a wide 

area are a necessary preliminary to the settlement of this question. It is to be remembered 

that the unconformity seems to imply the complete removal of the great quartzite series during 

the erosion interval and over wide areas. The time involved should therefore be more than a 

brief interruption. 

The House Range, which lies near the western boundary of Utah, between th~ 

39th and 40th parallels, comprises a section which according to ·walcott, "extends 

from well down in the Lower Cambrian to the base of the Ordovician, and is the 

best and most complete of the Basin Range sections so far studied." 
CAMBRIAN AND LO"\YER ORDOVICIAN. 107' 

Walcott's published section 859b (condensed) is as follows: 

Section of Cambrian rocks in House Range, Vtah. 

---~---~--

Formation. 

Upper Cambrian. 

Character. Thicknesd 

(feet). 

Notch Peak formation .... ______ . Gray arenaceous limestone in more or less massive layers............ 1,890 

Orr formation .... _._. _____ ....... · Gray slightly arenaceous limestones and shales...................... 1,82.5 

Middle Cambrian. 

Weeks formation ............... . 

Marjum formation .............. . 

Wheeler formation .............. . Swasey formation .............. . 

Dome formation .. ____ .......... . Howell formation .. _._ ..... _____ _ 

Lower Cambrian. 

Pioche formation ........ _ ...... . 

Prmpect Mountain formation .... 

Thin-bedded shaly limestones, with a few bands of oolitic and arena- ceous limestones. 

Gray to dark, more or less thin-bedded arenaceous limestone ...... _. 

Alternating bands of thin shaly limestone and calcareous shale ..... . Bluish-gray oolitic and arenaceous limestone, with some calcareous 

and argillaceous shales. 

Massive-bedded gray siliceous limestone ........................... . Dark, more or less massive limestone and pinkish argillaceous shales .. 

Arenaceous and argillaceous shaly layers with some thin layers and 

bands of limestone more or less irregularly interbedded and limited 

in horizontal distribution. 

Gray to brown quartzitic sandstones ............................... . 

Regarding the Pioche shale, Walcott 8590 states: 

j 

1,390 

1,092 

570 

238 

355 

640 

Thiclcness.-At Pioche, Nev., 210 feet. On the west face of the Highland Range, 18 miles 

west of Pioche, tllis formation is 170 feet thick. In the Eureka district of Nevada, 135 miles 

northwest of Pioche, this formation lies between the Prospect Mountain quartzitic sandstone 

and the great limestmie series and is about 200 feet in thickness. In the House Range sedion, 

105 miles north-northeast of Pioche, the formation is 125 feet thick. In the Big Cottonwood 

section of the "\Vasatch Range, about 125 miles northeast of the House Range, near the old 

shore line, the Pioche formation is represented by the lower portion of the arenaceous shales 

which are here 250 feet in thickness. The Pioche formation horizon is next met with to the 

north where the line of the Canadian Pacific Railroad crosses the Continental Divide. At this 

place the formation is called the ~fount Whyte formation. 

K 18. PENNSYLVANIA. 

The results reached by Stose in the study of the Chambersburg quadrangle, 

Pennsylvania, comprising part of South Mountain and the valley about Chambersburg, may be taken as representative for southeastern Pennsylvania. The following statement 800 is taken from an article in the Journal of Geology: 

The rocks in this area are largely concealed by the sandstone debris which covers the 

mountain tops as well as the valleys and slopes. Their character, thickness, and relation are 

therefore not readily determined. The structure is also complicated by schistosity and jointing 

which exist in all these rocks. The mountains are composed of Georgian (Lower Cambrian) 

quartzites, sandstones, and shales and older igneous rocks; the adjacent portions of the valley 

of Cambrian and Ordovician limestones and shales. 

Old volcanics.-The basement rocks exposed in the area are ancient volcanic rocks, greenstone and altered rhyolite, which underlie the basal Cambrian unconformably. They occupy 

the plateau-like tract overlooked by higher peaks in the center of the mountain area shown on 

the map and in the extreme southeast corner and are extensively developed to the eastward. 
108 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The volcanic origin of these ancient rocks is clearly shown by flow banding, amygdaloidal 

structure, and spherulites, as described by \Yilliams and Bascom. The greenstones are sheared 

dense rock, veined with asbestos and chlorite. The original structure is seldom preserved, but 

the rock is apparently an altered basalt. The rhyolitic rocks are of purple and red tints, often 

porphyritic and frequently banded by flow structure or spherulitic streaks. The rhyolitic rocks 

predominate in this area and apparently overlie the greenstone, for the basal Cambrian sediments 

are composed largely of rhyolitic fragments and not of basaltic detritus, as would be the case 

if the greenstone were younger and had been eroded from most of the area. 

Basal sandstones.-Overlying these softer rocks are about 4,500 feet of sandstone, quartzite, 

and shale of Georgian (Lower Cambrian) age. The basal beds, forming the higher and more 

rugged portions of the mountains, are composed of coarse purple and yellowish banded sandstones, fine conglomerate, and arkose, with white feldspathic and vitreous sandstones above. 

The purplish conglomerate bed is composed of small pebbles and grains of quartz, feldspar, 

and purplish slate or tuff, the flat slaty fragments often having a diameter of 2 inches. This 

grades almost imperceptibly through soft purplish arkose into the reddish rhyolitic eruptives 

below, demonstrating their derivation largely from similar volcanic rocks exposed along the 

near-by shore of the Georgian sea. In Maryland, and also at Mount Holly, at the north end 

of South Mountain, basal conglomerates contain numerous large quartz pebbles, probably in 

part derived from the granitic basement complex of the Piedmont. 

This basal sandstone, on account of its hardness, forms high, rugged ridges in the heart of 

the range, such as Rocky Mountain and Snowy Mountain. It is continuous with the Weverton 

sandstone of the Catoctin and South mountains, Maryland, as mapped by Keith, and the name 

is therefore used here. The underlying Loudoun formation, which is described by Keith as 

variable in composition and thickness in Maryland, was not recognized as a distinct formation 

in this area but may be represented in the soft arkose at the very base of the sedimentary series. 

Upper shales and sandstones.-Above the Weverton sandstone there are about 3,200 feet of 

shale and soft sandstone in which are two horizons of har;d, ridge-making sandstone. The 

softer beds are poorly exposed, being everywhere covered by the debris from the adjacent sandstones. Their presence is inferred from the fact that their outcrop is always occupied by valleys 

and depressions. Their character is indicated in part by occasional fragments of thin shaly 

sandstone and black banded slate or red ferruginous shale. The hard sandstone beds form the 

ridges along the mountain front and cap the high, flat-tipped Sandy Ridge, as well as Big Flat 

Ridge north of Fayetteville. The lower of the two sandstones is the more massive and is 

composed of a hard quartzitic stratum, usually of dark-gray color and veined with quartz, and 

a softer, granular, white layer containing long, slender scolithus tubes. The upper hard bed at 

the top of the shale is a milk-white or slightly pinkish granular calcareous sandstone, frequently 

disintegrating by the removal of the soluble cement to yellowish quartz sand, which is quarried 

for building purposes. This bed also contains numerous Scolithus linearis borings, and in 

places Camarella minor and fragments of Olenellus have been found, by which its age has been 

determined to be Georgian (Lower Cambrian). 

In the Catoctin and South mountains of Maryland Keith has mapped above the Weverton 

sandstone 800 to 1,200 feet of shale (Harpers) and 500 to 700 of sandstone (Antietam). The 

Harpers shale is typically exposed at Harpers Ferry, on the Potomac River, and, as described 

by Keith, consists of a bluish-gray shale with a few thin sandstone beds. Northward these 

Eandstone beds are said to thicken, some attaining 50 feet, but do not have an appreciable 

effect on the topography. On the road from Monterey to Waynesboro, in the southeast corner 

of the area shown on the map, this series is fairly well exposed, but, according to Keith, the 

structure is complicated by folding and faulting. Above the vVeverton sandstone in this section, as seen by the writer, are shales or slates, in part dark-banded, containing a conspicuous 

white scolithus-bearing sandstone 20 to 30 feet thick, all of which is mapped by Keith as 

Harpers shale. Above the shale is the scolithus sandstone in which Walcott found Olenellus and 

Camarella minor, as noted above, and which is mapped by Keith as Antietam sandstone. 
CAMBRIAN AND LOWER ORDOVICIAN": 109 

North of Little Antietam Creek there are two ridge-making sandstones above theW everton 

sandstone, one composing Sandy Ridge and the other Curve Mountain, and between them is 

black-banded slate with thin ferruginous sandstones. The upper bed forming Curve Mountain 

is undoubtedly the Antietam sandstone, and it is apparent that one of the sandstone beds in the 

Harpers shale of Maryland increases in prominence northward, so that in Pennsylvania it 

reaches such dimensions that it forms a distinct ridge. The Harpers formation in this area 

therefore consists of shales and soft sandstones, with a quartzitic member near the middle 

which is here named the Montalto quartzite, from Montalto Mountain. Northward the shale 

gradually thins, and the sandstone continues to expand until at the northern border of the area 

it occupies almost the whole interval of the formation, indicating a gradual change from a :fine 

mud deposit in the south to coarser siliceous sediments in the north. Similar conditions may 

have continued into Antietam time and have affected the deposition of the Antietam sandstone. 

The patchy occurrence of the Antietam in the Maryland area, as mapped and described by 

Keith, may be due to its irregular deposition in that area, instead of to infolding in the Harpers 

shale and to faulting, as previously supposed. Irregularity of Antietam sedimentation in the 

Pennsylvania area also is indicated by the absence of ridge-making character east and southeast 

of Montalto, where the bed is thin, disintegrated, and inconspicuous. 

In the columnar section of the Mercersburg-Chambersburg folio these older 

strata are given the following thicknesses by Stose: 802 

Shenandoah limestone. 

Antietam sandstone._ ........ __ ........................................................ . 

Harpers schist and Montalto quartzite member (20-850) __ ..... _ .......................... . 

IV everton sandstone ... _ ........ _ .. _ .................................................... . 

Old volcanics. 

Feet. 

500-800 

2,750 

1,250 

In' an article on the Cambrian and Ordovician limestones of the Appalachian 

Valley, S tose 801a says : 

The limestones of the Appalachian Valley, which in the South are separated into many 

formations, have generally been treated as a unit in the North under the name Shenandoah, or 

other local terms, such as Valley, Lancaster, Kittatinny, and York. These rocks include all 

the strata between the Cambrian quartzites of Georgian age and the Martinsburg ("Hudson") 

shale of Ordovician age. 

In a paper on the sedimentary rocks of South Mountain the author briefly described the 

formations comprising the Shenandoah group in southern Pennsylvania. Later studies of 

these rocks in the Cumberland Valley of Pennsylvania have furnished data for a more complete 

description of the group, including the faunal content and correlation, based on determinations 

by E. 0. Ulrich. 

The formations comprising the Shenandoah group in southern Pennsylvania are as follows: 

Martinsburg formation .......................................... -{~~::~ Trenton. 

{

Lower Trenton. 

Chambersburg limestone, 100-GOO feet .. _ ............. _ ......... __ Black River· · Lowville. 0.. 

;::l UpperChazy. 

~ Stones River limestone, 800-1,000 feet._ .............. _ ............ Lower and mid . 

Ordovician. 

..;J dle Chazy . .g Beekmantown limestone, 2,250-2,300 feet [including Stonehenge 

a limestone member at the base, 500 feet] ... _ .... _ .......... _ ...... Beekmantown. 

§ Conococheaguelimestone, 1,635± feet ............................ Saratogan. 

@ Elbrook formation, 3,000± feet ............................ -..... ·}A d' 

Waynesboro formation, 1,250± feet.............................. ca Ian. 

Tomstown limestone, 1,000± feet .............. ----.-.--------- ·}G · 

Antietam sandstone .... _____ .. ____ . ____________ . ___ . __ . __ ._______ eorgmn. 
110 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The Tomstown limestone * * * is composed largely of limestone, both massive and 

thin bedded, in part cherty, with some shale interbedded near the base. * * * [The more 

characteristic fossils which it has yielded are Salterella sp. undet., Kutorgina n. sp., and fragments of Olenellus. These definitely determine its age as Georgian (Lower Cambrian).-

G.W.S.] 

In central Virginia a formation 1,600 to 1,800 feet thick, occupying about the same interval 

but apparently including beds which in the Chambersburg area are calcareous sandstones and 

are mapped with the overlying ·waynesboro formation, has been named Sherwood limestone by 

H. D. Campbell. * * * 

The Waynesboro formation is a series of sandstones, purple shales, and limestones overlying 

the Tomstown formation. At the base are very siliceous gray limestones that weather to 

slabby porous sandstone, large round masses of rugose chert, and white vein quartz. In the 

middle of the formation are dark-blue to white subcrystalline limestones and dolomites, which 

become siliceous upward and merge into mottled slab by sandstone and dark-purple siliceous 3hale 

at the top. * * * A few poorly preserved shells, two of which are identified as Oboius (Lingulella) sp. undet., obtained from sandy shale at the very top of the formation, suggest Acadian 

(Middle Cambrian) age but are not conclusive. 

In central Virginia the Buena Vista shale, described by H. D. Campbell, is at this general 

horizon, but, as previously stated, apparently has a diff0rent lower limit. It is described as 

bright variegated shale, 600 to 900 feet thick, with mottled limestone and shale in the lower 

part. Mr. Walcott found in it a species of Ptychoparia related to Acadian (Middle Cambrian) 

species of Tennessee. 

The Elbrook formation is the thick series of gray to light-blue shaly limestone and calcareous 

shale that overlies the purple Waynesboro formation. The formation is decidedly shaly, most 

of the included limestones being minutely laminated and weather readily into calcareous shaly 

plates. * * * Near the middle are massive beds of dolomite and very siliceous or quartzitic 

limestone that weathers to porous slabby sandstone and frequently forms knobs and ridges. 

The formation is limited above by limestone conglomerates containing rounded vitreous quartz 

grains and others containing tabular fragments of limestone, which characterize the base of the 

overlying formation. * * * The only fossils found in this formation were fragments of 

trilobites, which suggest Acadian. 

The Conococheague limestone is characterized by beds containing thin sandy laminre 

and quartz grains that weather into hard shale fragments and thin slabby sandstones which 

generally give rise to rocky hills and rugged topography. 

The base of the formation is usually easily determined because it is marked by siliceous 

beds and conglomerates that produce a ridge. The conglomerates are of two kinds; one is 

composed of rounded limestone pebbles, 1 inch or more in size, in a matrix containing numerous 

round coarse grains of vitreous quartz; the other is composed of long slender fragments of 

limestone in a calcareous matrix, which, because the fragments are tilted at various angles, 

is called "edgewise" bed. Interbedded with the conglomerates are oolites and dark shaly 

limestones with red clay partings. 

The body of tho formation is a closely banded dark blue limestone, the bands varying from 

one-half inch in width to minute laminre. The banding is inconspicuous in the fresh rock 

but is brought out in weathering as yellowish sandy streaks across a light-blue or gray surface. 

Toward the top these partings become more numerous and sandy, and weather into hard 

sandy plates and sheets. Chert is not an important constituent of the formation in the Chambersburg and Mercersburg quadrangles. * * * The fossils found in this formation comprise Dikelocephalus hartii Walcott; D. sp. undet.; and Billingsella like B. desmopleura. The 

trilobites place this part of the formation definitely in the Saratogan (Upper Cambrian). In 

the basal conglomeratic beds a species of Cryptozoon, probably C. proliferum Hall, characterized 

by a mammiferous surface, the elevations one-half to 1 inch in diameter, is rather generally 

present. 
CAMBRIAN A~D LOWER ORDOVICIAN. 111 

The Beekmantown is a rather pure limestone lying between the siliceous Conococheague 

below and the very pure Stones River above. A minutely laminated appearance on weathered 

surfaces of many of the beds, due to their impurities, and pink to white fine-grained limestone 

or marble are characteristic features of the formation. Near the base are siliceous banded 

beds and large "edgewise" conglomerate, closely resembling the Conococheague formation. 

These have been separated ns a transition phase under the name Stonehenge member of the 

Beekmantown. 

Although sparingly fossiliferous as a whole, the Beekmantown has yielded 

a large variety of forms, which are listed in Stose's paper and in accordance with 

which the Pennsylvania occurrence is correlated by Ulrich 'vith the New York 

formation of the same name. 

For descriptions of the overlying later Ordovician limestones see Chapter IV 

(pp. 176-179). 

The Cnmbrian and Ordovician limestones n,re exposed in Center County, Pa., 

on the Nittany anticline, where Ulrich has distinguished severn1 suhdivisions of 

the Beekmantown. 

In eastern Pennsylvania, in the vicinity of Philadelphia, the early Paleozoic 

rocks are highly metamorphosed. The vVissahickon mica. gneiss, which has been 

considered to be of Cumbrian or Ordovician age, is now regarded as pre-Cambrian. 

Its relations to the Paleozoic are clearly described by Bascom. ssa The Cambrian 

is represented by the Chickies quartzite and part of the Shenandoah limestone. 

The upper part of the Shenandoah is of Lower Ordovician age, probably Beekmantown. The middle and possibly later Ordovician are represented by the 

Octoraro schist, in some part at least. (See pp. 177-178.) 

Regarding the Cambrian and Lower Ordovician (Chickies quartzite and 

Shenandoah limestone), Bascom says: 

The Chickies quartzite usually shows a conglomeratic lower member, which is largely 

composed of elongated pebbles of the blue quartz that characterizes the pegmatites and 

some facies of the Baltimore gneiss. This lower member of the quartzite is not often exposed. 

* * * The conglomerate passes upward into a gray, compact, crystalline quartzite, which, 

in turn, grades into a siliceous slate or a sericitic quartz schist, or is altogether supplanted by 

the quartz schist. * * * 

Thirty miles west of the Philadelphia district a section through the Chickies quartzite 

shows a considerable thickness of micaceous feldspathic material interbedded with the quartzite. 

Such beds occur as the uppermost niember of the series, separating typical quartzite from 

the overlying limestone, and also as a lower member. Toward the east these micaceous beds 

become very thin and are altogether absent from the Philadelphia district. * * * 

The thickness of the formation varies; it never exceeds and is often less than 1,300 feet, 

although the isoclinal folding in some localities gives the appearance of greater thickness. An 

overturned synclinorium with stratification and cleavage dips to the southeast is the prevailing 

structure. * * * 

The name of the formation is taken from the locality of its finest exposure and greatest 

thickness, on Susquehanna River north of Columbia. At this locality the quartzite shows 

abundant traces of Scolithuslinearis, as is the case also in the North Valley Hills, and underlies 

quartzite in which Olenellus fragments have been found by Walcott, thus establishing its age 

as Georgian ("Lower Cambrian"). The quartzite of the Philadelphia district deposited farther 

to the east than this typical exposure of Georgian quartzite on Susquehanna River may have 

been laid down in an encroaching sea and thus belong to a later stage in the Cambrian than the 

Georgian. No forms of life save Scolithus linearis have been found in it, hence it can not posi-
112 INDEX TO THE STRATIGRAPHY OF NORTH ·AMERICA. 

tively be stated to be of Georgian age. It can, however, be safely affirmed to be Cambrian 

and is to be correlated with the Cheshire quartzite of New England, the Poughquag quartzite 

of New York, the Hardyston quartzite of Kew Jersey and provisionally with the Setters quartzite of Maryland. It is the Primal sandstone of H. D. Rogers and the Formation No. 1, Chickies 

sandstone of the Second Geological Survey of Pennsylvania. * * * 

The Shenandoah ("Chester Valley") limestone is a heavily bedded crystalline white or 

blue magnesian limestone. Its surface exposure in the Philadelphia district is confined, with 

a few scattered outcrops along the Huntingdon and Cream Valley faults, to Chester Valley, 

where it covers an area 20 miles long and 2 to 2! miles wide. * * * The limestone is highly 

siliceous and magnesian. The analyses show great variation in the percentages of Si02 and 

MgO, but no analysis gives a sufficiently high content of MgO to warrant calling the formation 

a dolomite. It is everywhere crystalline, and increasingly so from west to east. Associated 

with increasing crystallinity is a lighter color, though blue and white limestone may occur in 

the same quarry. 

It is in places quite micaceous, and always so in the neighborhood of the overlying mica 

schist. The beds immediately underlying the mica schist are siliceous, micaceous, and schistose 

and are to be characterized as calcareous schist. The limestone is abundantly traversed by 

calcite and quartz veins. Quartz, feldspar, phlogopite, graphite, pyrite, and siderite are accessory constit"qents, disseminated in minute grains and crystals. Limonitic iron ore occurs in 

pockets in the limestone. 

Intercalated with the limestone are beds of siliceous 01; micaceous schists. These intercalations, which are lenticular in character, are conspicuous in the limestone west of the Philadelphia district but occur infrequently in that portion of the limestone confined to Chester 

Valley. Near Pomeroy, 25 miles west of the Philadelphia district, an intraformational calcareous conglomerate shows near the top of the formation. * * * 

If the interpretation of the structure given above is correct the thickness of the formation 

must be much less than the width of its outcrop. It is not determinable exactly, but probably 

is notgreater than 1,000 :feet. 

Fossils of Chazy, Beekmantown, and Trenton ages have been found in the limestone 

occurring to the west of Chester Valley and stratigraphically continuous with the limestone of 

Chester Valley. Fossils have also been found in Chester Valley in somewhat ambiguous material. 

This material is a drusy, geodiferous rock which seems to have originated through the replacement of calcareous material by silica. A mass of the rock is exposed just south of Bridgeport, 

near the Trenton branch of the Philadelphia Railroad. Elsewhere it is found only in scattered 

fragments which rest on the limestone and accompany more or less persistently the contact of 

limestone and Octoraro schist. It thus seems to mark a definite horizon whose persistence 

between the schist and the limestone precludes the possibility of a faulted or an unconformable 

contact. 

The material has not proved fossiliferous except at one locality, near Henderson station, 

where fragments resting on the surface of the ground have been found to contain gastropod 

and cephalopod forms. 

The following determinations were made by E. 0. Ulrich, of the United States Geological 

Survey: Raphistoma, two species, Maclurea, Lituites, Cyrtoceras. These are Ordovician forms 

and indicate a horizon in the lower half, probably Beekmantown. The limestone overlies conformably Georgian ("Lower Cambrian") quartzite and is therefore Cambro-Ordovician in age. 

It is correlated with the Stockbridge limestone of ~ ew England and New York, doubtfully 

with the Cockeysville marble of Maryland, and with the Shenandoah limestone of Virginia. 

It is the most easterly representative of the great belt of limestone, the Auroral limestone of 

H. D. Rogers and Formation No. II of the Second Geological Survey of Pennsylvania. Aside 

from a. few scattered and very minor exposures, the limestone of the Philadelphia district is 

confined to and controls the form of Chester Valley, a conspicuous topographic feature of the 

district. For this reason it has long been locally known as the "Chester Valley limestone.'' 
CAMBRIAN AND LOWER ORDOVICIAN. 113 

It is here called the Shenandoah because it has the same limits and stratigraphic associations 

as the extensive and well-known limestone of that name. 

That calcareous sedimentation, which began in Cambrian time, continued into Ordovician 

time is shown by the presence of Lower Ordovician fossils in an upper member of the Shenandoah 

limestone. 

Further sedimentation in Ordovician time is represented by the Octoraro. This is the 

best-known Paleozoic deposit in this region and, like the preceding Paleozoic sediments, is 

dynamically metamorphosed and free from igneous intrusions. 

K 18. NEW JERSEY. 

The Cambrian and Lower Ordovician strata of New Jersey have been described 

recently by Weller 880a and Kti.mmeP13 on the basis of earlier reports and recent field 

work. From Kti.mmel's paper we take the following general description: 

The Hardyston quartzite is the lowest formation of the Cambrian system, and is probably 

to be correlated with the Poughquag quartzite of Dutchess County, N. Y., and the Chickies 

quartzite of Pennsylvania. It is unconformable on the pre-Cambrian complex and is the oldest 

fossiliferous rock in New Jersey. It varies considerably in composition and thickness. Typically it is a quartzite, at many places conglomeratic and containing pebbles of quartz, feldspar, 

granite, gneiss, and slate. Locally the formation is a calcareous sandstone. It is usually but 

not invariably feldspathic. In some localities its arkose character is so marked that it is not 

readily distinguishable from a coarse granite. Beds of slate occur in its upper portion. 

Its thickness ranges from a few feet to 200 or more, and it passes into the overlying sandstone through slaty or shaly layers, several of which are in places interbedded with limestone 

layers, so that its upper limits are indefinite. Since it contains a species of Olenellus, it is 

regarded as of Georgian (Lower Cambrian) age. 

The Hardyston quartzite grades upward into the thick magnesian Kittatinny limestone 

of the Kittatinny Valley. Above, it is limited by an unconformity at the base- of the Jacksonburg (Trenton) limestone. The presence of thin shales and scattered seams of sandstone in 

the great mass of limestone shows an influx of land sediments at recurrent intervals during 

its formation. 

The known fauna of the Kittatinny is not extensive and is found at but few localities, but 

it suffices to establish the Cambrian age of the greater part of the formation. No Middle Cambrian fossils have been found, but as the Olenellus fauna of the Hardyston quartzite is considered to be of Lower Cambrian age, and as no evidence of a break in sedimentation has been 

observed, a Middle Cambrian fauna would naturally be expected between the Olenellus fauna 

below and the Dikelocephalus fauna above. In one locality a fauna of Ordovician (Beekmantown) age has been found in beds near the top of the Kittatinny limestone. This formation, 

therefore, where complete, represents a period extending from the middle or upper part of 

the Lower Cambrian to the lower part of the Ordovician, inclusive. 

From a discussion of the fossils found in the Kittatinny limestone, probably 

mostly from its upper portion, Weller ssoa concludes: 

The position of these various fossiliferous beds of the Kittatinny limestone in the formation as a whole can not be determined with certainty, but it may probably be stated, with a 

degree of safety, that all of these fossiliferous localities, with the exception of that near Carpentersville, are in the upper portion of the formation. The Carpentersville locality is probably 

somewhere in the lower third of the entire series. So far as the fossils afford any definite evidence, the age of all is upper Cambrian. No middle Cambrian faunas have been recognized, 

although the Olenellus fauna of the Hardyston quartzite is usually considered to be of lower 

Cambrian age, and a middle Cambrian fauna would naturally be expected to occur somewhere 

in the formation. 

48011°-]2-~ 
114 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

K 18. SLATE BELT, EASTERN NEW YORK AND WESTERN NEW ENGLAND. 

The stratigraphy and structure of eastern New York and adjacent New England 

were worked out by Walcott in 1886 and 1887, and the results were published in 

part in a paper entitled" The Taconic system of Emmons." 849 Dale 207" subsequently 

studied the "slate belt," of which the Taconic Range is a central feature, and incorporated Walcott's manuscript material and other data in a report from which the 

following extract is taken. (See also references to Cambrian and Lower Ordovician 

in Chapter IV, pp. 183-192.) 

The formations shown [on the geologic map] are but two-Lower Cambrian and Lower 

Silurian (Ordovician). The larger part is Cambrian. This includes the "sea-green," the 

"unfading green," the purple, and the mottled slates, while the "red" slates, with the accompanying "bright-green" slates, are in the Ordovician. An area of about 8 square miles in 

Benson containing black roofing slates is of uncertain age-certainly Cambrian or Ordovician, 

quite possibly Ordovician. The Ordovician areas are very irregular-in some places isolated 

lenticular masses, compound synclinal in structure, surrounded by and overlying the Cambrian. Some very small isolated Ordovician areas-as near Hillsdale, west of Middle Granville, and west of Lake St. Catherine, near the Wells and Poultney line-probably represent 

single and overturned synclines. The Ordovician also surrounds lenticular masses of Cambrian, probably compound anticlinal in structure, which protrude through the Ordovician. 

The central belt of Ordovician sends out long, narrow spurs into the Cambrian area; which 

alternate with tapering, baylike recesses of Cambrian, the formations being thus dovetailed into one another. On the eastern side the Cambrian slate series comes into contact 

with the Ordovician schist mass of the Taconic Range; but north of Rupert and east of 

West Pawlet, Vt., for a space of 6 miles there appears to be a transition from the Ordovician slate into the Ordovician schist. The central Ordovician belt, with all its complex 

ramifications, thus appears to be merely a continuation of the mass of the Taconic Range 

itself, and 40 miles south, in Petersburg, Rensselaer County, N.Y., a continuation of the same 

Ordovician area again merges into the schists of the Taconic Range. Hudson graptolites also 

occur quite close to the schist mass in Pawlet. * * * 

Owing to excessive and minute folding, as well as cleavage and the friable character of some 

of the shales, it has been found very difficult to construct an entirely satisfactory columnar 

section of the strata. The relative position of some of them is doubtful, owing to their intermittent character and the possibility of their merging along the strike into other members of 

the series. The thickness of several of them is uncertain, owing to scarcity of measurable 

sections. As the lower limit of the Cambrian is nowhere reached within the slate belt the 

section starts with an uncertainty, and the prevalence of shales in the drdovician makes 

the top of the column indefinite. 

Dale gives a table showing the probable equivalence of the various divisions 

reeognized in the great sequence of Cambrian and Ordovician shales. 

For an account of the Cambrian and Ordovieian of ~Iount Greylock and 

adjacent areas in western Massachusetts, see Chapter IV (pp. 192-194). 

K 19. EASTERN MASSACHUSETTS. 

The Cambrian rocks of the Boston Basin were thus described by Crosby: 181 

The oldest rocks which we have found are the Primordial slates and quartzites; and the 

age of these is certainly and definitely known only at the Paradoxides quarry, in Braintree. We. 

appear to be justified, however, in regarding them, provisionally at least, as all of about the 

same age, partly on account of a general lithologic resemblance, but mainly because their relations to the different classes of eruptive rocks are everywhere the same. In Weymouth and 
CAMBRIAN AND LOWER ORDOVICIA~. 115 

Braintree, where we first met these rocks, they are either typical clay slates or slightly calcareous; 

but along the northern base of the Blue Hills occasional layers are distinctly siliceous. They 

probably underlie a large part of the Boston Basin, being covered by the conglomerate and the 

newer slate; and north of the basin they occur in isolated areas among the eruptive rocks. In 

some of these areas, especially in the Middlesex Fells and Melrose, and in Woburn, clay slate 

similar to that in Quincy and Braintree is repeatedly interstratified with quartzite; while 

toward the southwest, in Natick, and also in Reading and Lynnfield, there are extensive developments of quartzite with little or no slate. It is very elear that the quartzite north and west 

of the Boston Basin is the source of the quartzite pebbles which play such a prominent part in 

the composition of the conglomerate, especially in the central and northwestern sections of the 

basin. In general, the quartzite is more and the slate less abundant northwestward, indicating 

that the ancient shore line along which these strata were deposited lay in that direction; and 

originally the Primordial strata were probably spread continuously over all the region to the 

southeast of that line. 

Crosby 180 in his earlier work included in the Cambrian the Roxbury conglomerate, which he 182 and others now assign to the Carboniferous. 

The fossiliferous slates of Braintree are referred to in the literature on the 

geology of eastern Massachusetts since 1818. Fossils were described by W. B. · 

Rogers, who stated: 675 

The rock in which these fossils occur is a compact, dense, rather fine-grained silico-argillaceous slate or slaty sandstone, containing little or no carbonate of lime. * * * One of 

the most curious facts relating to the trilobite of the Quincy and Braintree belt is its seeming 

identity with Paradoxides harlani, described by Green in his monograph of North American 

trilobites. 

Recent finds of fossils belonging to the Braintree slate are reported by Shimer,739 

who says: 

Some time ago while having a driveway excavated at his home on Quincy Avenue, in East 

Braintree, Mass., Mr. Thomas A. Watson found a rather angular slate bowlder, about 2 feet 

in diameter. He kindly turned it over to the Massachusetts Institute of Technology. 

The slate is quite similar in appearance to that of the celebrated Paradoxides quarry 

on Hayward Creek; it is similarly metamorphosed but is lighter gray in color and lacks the 

peculiar purplish tinge of the Hayward Creek slate. 

In it the following fauna was found: 

------------N-am-e.----------~un-1 

dance.a Previous occurrence. Age. 

Acrothere gamagei (Hobbs) ........................... _ 

Hyolithes shaleri Walcott.. __ ............. -- ... --- .. -. Paradoxides harlani Green ........................... _I 

Strenuella strenua (Billings) .................... ······· i 

?Strenuella strenua (Billings) ......................... . Olen ell us (Holmia) bri:iggeri Walcott ................... . Ptychoparia rogersi Walcott ......................... . 

Agraulos quadrangularis (Whitfield) ................... . 

r 1 Hayward Creek ........ Middle Cambrian. r Hayward Creek ........ Middle Cambrian. 

C Hayward Creek ........ Middle Cambrian. 

H North Attleboro, North Lower Cambrian. 

H 

H 

r 

c 

Weymouth, and Nahant. 

North Weymouth. . . . . . Lower Cambrian. 

Hayward Creek........ Middle Cambrian. 

Hayward Creek ........ Middle Cambrian. 

---------------------

a C=very common; c=c:ommon; r=rare; H=very rare. 

This fauna includes five species of the Middle Cambrian, two of which are very abundant, 

and two of the Lower Cambrian. There is thus a great predominance of the Middle Cambrian 

element, though it indicates a persistence of the Lower Cambrian element into Middle Cambrian 

times. So while we have here a transition fauna, the rock must be assigned to the Middle 
116 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Cambrian period. This very interesting transition fauna is the first recorded from this region 

to show in any way a passage from the Lower to the Middle Cambrian. 

Shaler and Foerste 732a found other localities of occurrence of Cambrian strata 

at North Attleboro, Mass. The fossils belong to the Olenellus zone and occur in 

red shales and limestone. At the several separate localities the following forms 

have been collected : 

Locality 1, Hyolithes princeps?, Hyolithes micans, H. billingsi, Stenotheca rugosa var. pauper, 

Salterella curvata, Pleurotomaria (Raphistoma) attleboroensis, Fordilla troyensis. In red shale 

near by occurred Agraulus strenuus. 

At locality 2 were found: Obolella atlantica Walcott, Obolella crassa Hall, Scenella reticulata 

Billings, Stenotheca curvirostra S. & F., Stenotheca rugosa var. abrupta S. & F., Platyceras prim:£vum Billings, Hyolithes {Lmericanus, Hyolithes communis var. emmonsi For'd, Hyolithes 

quadricostatus S. & F., Microdiscus bellimarginatus S. & F., M. lobatus Hall, Olenellus walcotti 

S. & F. (probably a young form. of some known species), Ptychoparia attleboroensis S. & F. 

(probably the young form of some species of trilobite), Agraulus strenuus? Billings. 

K-L 12-13. WYOMING. 

Cambrian strata which outcrop around the crystalline rocks of the Bighorn 

Mountains constitute the Deadwood formation. They consist of sandstones, shales, 

and limestones from 850 to 1,050 feet in thickness. 

Darton 239a gives many details of local variation in character. The following 

is a representative section:-

Section of Deadwood formation in Wolf Greek canyon, west of Sheridan, Wyo. 

White massive sandstone at base of Bighorn limestone. Feet. 

Thin-bedded limestone, gray, greenish, and pinkish tints, with flat-pebble limestone conglomerate and glauconite ............................. _ .. __ ... _._- ........ ______ ......... _ . _ .. __ 300 

Gray and greenish shale with thin limestones and sandstones .. _____ . _ ........ ___ ..... __ . __ . . . 800 

Brown to buff massive sandstone; many fossils ............... ___ ._ .......... ____ ..... ___ .... 50 

Thin-bedded brown and gray sandstones ................. _._._. __ ............ __ ...... ___ .... _ 50 

Gray sandstones and shales ................... _ .. _______ - _ ......... _ .. __ ......... _ ....... _ _ 35 

Hard brown cross-bedded sandstone ............... _. __ . __ ._ .......... __ ._ ..... _ ........ ___ . 6 

Brown sandstone and sandy shale ___ ._ .... _ .. _ .................. _ .............. _ ....... _.... 30 

Dirty-buff to brown and reddish soft cross-bedded sandstone; much glauconite; many fossils... 20 

Soft greenish-gray sandstone .................................... -- ........... _.............. 12 

Buff sandstone with fossils ...................................... -- .......... __ ........ _.... 8 

Dark-gray and greenish shales with thin sandstone beds above_ .... _ .......... ___ ......... _ ... _ 200 

Coarse-grained cross-bedded buff to brown, massive sandstone................................. 30 

The distribution of the Deadwood formation in central Wyoming has recently 

been described by Darton 244a as follows: 

General relations.-The sandstone of the Deadwood formation is at the base of the sedimentary series in northern and central Wyoming. It thins out to the southeast and apparently 

ceases at no great distance east of longitude 107°, so that in Converse, Albany, and Laramie 

counties the Carboniferous rocks lie directly on pre-Cambrian granites and schists. In the 

Shirley Hills a hard, massive sandstone and conglomerate underlying Madison limestone may 

be Deadwood. On the West Fork of Troublesome Creek, 9 miles northwest of Difficulty post 

office and about Leo, this sandstone, 30 feet or more thick, is hard and in part conglomeratic. 

Near North Platte River, north of the mouth of the Medicine Bow, it is about 100 feet thick. 

Whether in these areas it is a shore deposit of Madison age or the Deadwood formation was 

not ascertained. In the basal sandstone in the gorge of North Platte River, 3 miles northeast 

of Pathfinder, Mr. Walcott found a few fragmeptary fossils which he regards as Cambrian. 
CAMBRIAN AND LOWER ORDOVICIAN. 117 

The hard sandstone at the base of the sedimentary series in the Casper Range and in the 

ridges to the southeast appears to be a shore deposit of the Casper formation. 

Rattlesnake Mountains.-The Deadwood formation outcrops along a portion of the crest 

of Rattlesnake Mountains west of Oil City. It is about 800 feet thick. At the base and near 

the middle. are 25 to 40 feet of brown to buff fossiliferous sandstone and the basal beds are 

somewhat quartzitic. Sandy gray shale with thin gray sandstone layers constitute the greater 

part of the formation, but there is a small amount of impure slabby limestone and reddish 

shale near the top. Glauconite is a conspicuous ingredient in most beds. 

Wind River Mountains.-On the northeast slope of Wind River Mountains the Deadwood 

formation is about 750 feet thick, and it presents all the features which are characteristic in 

the Bighorn and other ranges northeastward. Its presence was recognized by Comstock and 

its distribution was shown .in part on maps of the Hayden Survey. 

The basal member, which lies on granite, is about 100 feet thick and is the usual hard 

brownish sandstone. Next are sandy shales and slab by limestone, the latter including more 

or less of the typical :flat-pebble conglomerate of gray limestone pebbles covered with glauconite. 

The top layer of this limestone contains many trilobites. At the top of the formation is a 

hard, coarse, fossiliferous sandstone. 

Owl Greek ltfountains.-Extensive exposures of the Deadwood formation extend along the 

upper slopes of Owl Creek Mountains and in the canyon of Bighorn River. It also appears 

along Crow Creek northeast of Circle and in Owl Creek canyon. The thickness is 900 feet and 

the succession of rocks is similar to that in the Bighorn and Wind River mountains. At the 

base is hard coarse-grained reddish-brown sandstone, locally conglomeratic below and lying on 

a remarkably smooth plain of the pre-Cambrian rocks. It varies from 50 to 100 feet in 

thickness and is succeeded by 200 to 300 feet of sandy shales and thin-bedded sandstones, 

with a prominent bed of sandstone in their lower portion. In Bighorn Canyon this bed is 50 

to 60 feet thick and of bright reddish brown color. The medial member is 400 feet or more 

of soft greenish-gray shale with a conspicuous gray to buff limestone in its lower part. This 

limestone, usually 50 feet thick, consists partly of :flat pebble limestone conglomerate. Southwest of Embar it is 30 feet thick and 300 feet above the base of the formation. At the head of 

Muddy Creek it is 40 feet thick and underlain by a somewhat thicker mass of sediments. The 

top member of the formation is slabby light colored limestone over 100 feet thick at most 

localities, but apparently either very thin or absent in Owl Creek canyon. It contains frequent 

layers and masses of the characteristic intraformational conglomerate of :flat limestone pebbles 

more or less intermingled with thin, twisted, and broken layers of limestone in a matrix of 

shale and fine limestone sand. Many of the pebbles are so thickly covered with grains of 

glauconite that they appear to be green, put inside they are gray or pinkish, similar to the 

associated beds. 

FossiZs.-Fossils at various horizons in the Deadwood formation are of middle Cambrian 

age, and Dicelamus politus and Ptychoparia oweni are the principal forms. The former is a 

small oval shell, which occurs in great abundance in the middle sandstones and in the limestone 

layers in the shales, as well as in the upper limestone series. The Ptychoparia is a trilobite 

which often abounds in the basal sandstone. In the middle sandstone of the formation, a 

short distance west of Garfield Peak of Rattlesnake Mountains, the fossils included a new 

species, which Mr. Walcott has designated Obolus ( Westonia) dartoni. In the top sandstone 

west of Lander, Orthis (Plectorthis) [Eoorthis] wichitaensis was found. 

Blackwelder, in an unpublished manuscript (1910), says: 

The Deadwood formation of central Wyoming expands westward without suffering much 

change in lithologic character. Near the south end of the Teton Range the basal sandstone 

is still only 160 feet thick, but it is overlain by fossiliferous shales and striped limestones, 

which are locally conglomeratic and oolitic, to a thickness of 1,000 to 1,100 feet. The supposed 

Cambrian beds are not sharply separated from the overlying massive limestones which contain 

Ordovician and Silurian fossils. 
118 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

K-L 13. BLACK HILLS, SOUTH DAKOTA. 

The Cambrian Deadwood formation of the Black Hills is described by Darton 2328 

in detail in his paper on the geology of the hills. A convenient summary of the facts 

is given in a later paper, 237 a as follows: 

Deadwood formation.-The outcrop of this formation encircles the Black Hills, appearing 

usually in the base of the great infacing limestone escarpment. It lies on a relatively smooth 

surface of Algonkian rocks, although there are many local irregularities of shore lines and beach 

phenomena. The rocks are mostly sandstones and sandy shales, with frequent occurrences of 

basal conglomerate. In the southern hills the thickness varies from 4 feet to 50 feet in greater 

part, and the principal material is a eoarse dark~brown massive sandstone. To the northward 

the formation gradually thickens, apparently by the addition of higher beds comprising darkgray shales, mostly sandy, and beds of sandstone. In the region about Deadwood, where the 

formation attains its greatest thickness of over 400 feet, it comprises about 30 feet of basal conglomerate overlain by 30 feet of coarse dark-brown sandstone; 200 to 400 feet of gray shales, with 

layers of flaggy limestone, limestone conglomerate, and sandstone; a conspicuous member of 

hard massive sandstone 5 to 12 feet thick; and at the top 20 to 45 feet of green shales. The limestone conglomerate is a very characteristic rock, consisting of flat pebbles and flakes of limestone 

more or less thickly sprinkled with glauconite grains, and is of the intraformational type. 

Throughout its course the formation contains fossils of which the following middle Cambrian 

forms have been reported by C. D. Walcott: Obolus, Hyolithes, Dicellomus, Asaphiscus, Olenoides, Ptychoparia, and Aerotreta. 

K-L 15-16. MINNESOTA, WISCONSIN, AND MICHIGAN. 

Sardeson 700 suggests that the "New Ulm" quartzite of southern Minnesota 

may be of Cambrian age, as it contains pebbles of "quartzite conglomerate like the 

rock (Huronian~) which is in situ at Redstone." The well records/ 94 however, 

which have been carried across southern Minnesota, from the type region of the 

Sioux quartzite (Algonkian) to and beyond New Ulm, have served to correlate this 

quartzite with the Algonkian Sioux quartzite. 

The Cambrian and lower Ordovician strata of the upper Mississippi Valley have 

been divided by recent writers into the following formations, all of which are well 

established in the literature of several States: 

Ordovician: 

St. Peter sandstone. 

Prairie d u Chien group (former 1 y called " Lower M!}gnesian limestone"): 

Shakopee dolomite. 

New Richmond sandstone. 

Oneota dolomite. 

Cambrian: 

Jordan sandstone. 

St. Lawrence formation 

Dresbach sandstone. 

Shales and sandstones. 

The Cambrian strata in southern Wisconsin were described as the "Potsdam 

sandstone" by Chamberlin, 133 who stated the synopsis of characters thus in part: 

Rocks mainly light-colored sandstone in central and southern Wisconsin and red sandstone 

in the Lake Superior region, but embrace some beds of limestone and shale. Maximum known 

thickness about 1,000 feet. 
-------------------------------------

CAMBRIAN AND LOWER ORDOVICIAN. 119 

Following this synopsis is an account of the conditions of deposition of the sandstone and of the life of the epoch, from which the following is taken: 

On the southern side of the Archean island the lower part of the formation usually consists 

of coarse quartzose sand, of an exceeding open, porous nature, with but little aluminous or ferruginous and almost no calcareous matter. Higher in the series the sandstone becomes finer 

grained and the accessory substances named more abundant. Somewhat above the middle of 

the series a stratum of shale occurs, attaining a known thickness of 80 feet. This is not everywhere present and seems to be mainly developed at some distance from the ancient shore line. 

It appears to indicate that for a time there was a deepening of the waters, admitting of the accumulation of fine sediment, ex~ept near the shore, where the deposit of sand continued. Above 

the shale, sandstone reaching a thickness of 150 feet is again found. This is mediumor coarse 

grained and slightly calcareous. It in turn is overlain by a deposit of associated shale and limestone (the Mendota limestone), which attains a thickness of 35 feet in the vicinity of the lake 

from which it derives its name. These beds indicate a modification of the conditions of deposition, such as to permit not·only the settling of fine sediment but the accumulation of calcareous 

mud as well. The latter was doubtless derived from the calcareous remains of life, since the sea 

then swarmed with living organisms whose shells and skeletons are found entombed in the strata. 

The frequency of broken and worn fragments implies that the greater portion were ground to 

powder, forming the calcareous flour that subsequently hardened into limestone. These beds 

appear to point quite surely to a moderate deepening of the waters. 

Overlying this impure limestone is a third and thinner bed of sandstone (the Madison') with 

which the Potsdam series closes. This, on the whole, is finer grained than that below and is 

bound more firmly together by cementing material, which is mainly a calcareous and ferruginous 

infiltration. The thickness of this bed is about 30 feet. 

The" Lower Magnesian limestone'' (Prairie du Chien group), which overlies the 

Cambrian strata, is described by Chamberlin as the equivalent of the "Calciferous" 

(Beekmantown) of New York, and as a " cherty magnesian limestone, from 65 to 250 

feet thick," which " contains but few fossils." Chamberlin 133a says further: 

During the previous epoch the accumulation of sandstone gave place for a time to the formation,of limestone (the Mendota). At the close of the epoch, without any very marked disturbance of existing conditions, the formation of limestone was resumed and progressed, with some 

interruption, till a thickness varying from 65 feet to 250 feet was attained. This variation in 

thickness is mainly due to irregularities of the upper surface of the formation, which is undulaLory 

and, indeed, in some localities may appropriately be termed billowy, the surface rising and falling 

like the swells of a subsiding ;,ea. In the localities where these phenomena are best developed, 

these petrous billows vary in height from a gentle swell to elliptical domes rising a hundred feet 

above their bases, while their length ranges from a few rods to a quarter of a mile or more, and 

their width from one-third ~o one-half their length. The symmetry of outline here indicated is 

frequent and typical, though not universal. It finds its best-observed expression in Green Lake 

and Winnebago counties, where the axes of the domes lie in an east-westerly directi-on much 

more commonly than otherwise, or, in other words, are at right angles to the trend of the formation. While not equally conspicuous everywhere, this undulatory surface is prevalent throughout the State and beyond. 

The internal structure of these roc.k billows is interesting. In the more typical ones at least, 

and perhaps universally, tho superficial strata dip in every direction from the center, most 

rapidly at the sides (the dip sometimes reaching 30°), and less so at tho extremities; or, in other 

terms, the beds are generally concentric with the surface. The rock of this superficial portion 

is as homogeneous and even grained a dolomitic limestone as is common to the formation and 

presents no unusual evidence of fracture or disturbance. Indeed, the rock gives the impression 

of having been laid down as a mantle of calcareous sediment over an irregular surface. 
120 INDEX. TO THE STRATIGRAPHY OF NORTH AMERIGA. .. 

Where erosion has exposed the interior, howev:er, a very different structure is exhibited. 

The core of the .dome appears to be composed of a brecciated mass formed of limestone fragments bound·together by calcareous material that seems to have been a mud derived from the 

/ wear of the rocks themselves. Although the base of the formation has never been seen immediately beneath one of these prominences, yet from all that can be ascertained from the study 

of the lower beds in the vicinity, it is probable that the basal strata are homoge~eous and 

horizontal, and unaffected by the peculiarities that lie above. 

~ * * * * * * * ' * 

In addition to the foregoing peculiarities of stratification, the unity of the formation in 

eastern Wisconsin is interrupted by a shaly stratum in its subcentral portion, ~nd in .northwestern ·Wisconsin by a sandstone layer of very irregular thicknes~· sometimes merely consisting 

of a layer of lenticular or pocket-like deposits. Locally there are seams of sand and shale 

intercalated in the series, particularly in the basal portion. 

The bedding of the rock is UE;ually uneven and heavy, and its texture is coarse, rough, and 

irregular, .though exceptionally it becomes uniform in bedding and grain, forming a beautiful 

and serviceable rock. · 

In composition it is, in the main, a magnesian limestone, or, more .technically, a dolomite. 

But it contains in addition much siliceous material, most commonly in the form of flint or 

chert nodules but sometimes in disseminated sand grains and not infrequently as an oolite, 

in which the center of the spherules is a grain of sand, about which concentric layers of cal-. 

careous material are gathered. Silica also often constitute!' a crystalline lining of cavities, 

forming beautiful little geodes lined with variously colored quartz. A varying amount of 

aluminous. impurity is also present throughout the rock. 

A notable feature of the formation is the occurrence, at various heights, of brecciated layers· 

interstratified with' others more homogell:eous. These are composed of fragments of limestone 

in a matrix of finer material, derived from the same source. They seem to indicate that the 

,formation, during its deposition, suffered successive variations of conditions, from comparative 

quiet to forcible wave action, probably due to slight oscillatjons of level. The comparative 

. absence' of fossils under such circumstances is not surprising. There seems little doubt, however, that the material of the formation was derived mainly ~rom the calcareous remains of life .. 

Chamberlin and later writers have described· the St. Peter sandstone, w.hich 

overlies the Prairie du Chien group(" Lower Magnesian limestone") asOrdovician .. 

(Seep. 180.) Walcott 854b quotes the.descriptions of the Cambrian strata by Irving, 

Strong, Wooster, and Winchell, in addition to the account by Chamberlin. The 

·descriptions of Chamberlin have been supplemented in later work by more exte~ded 

investigation and correlation of the. faunas by Sardeson 699 and by Ulrich.821 

K-L 18. ADIRONDACK REGION, NEW YORK. 

The Potsdam sandstone of the A4irondack region has been recently studied 

by Cushing, zoaa fro;m ·whose detailed account the following passages are taken: 

Lying unconformably on the old and much eroded pre-Caml;>ric surface, ·a great sandstone 

fo.rmation appears, on the north and east and on the eastern half of the southern border of the 

:Adirondack region. This is a water-deposited formation and, so far at least as its upper portion is concerned, a marine formation. It is thickest on the northeast, thinning out to disappearance both to the south and west. As, furthermore, it appears to be the upper beds which 

persist and the lower ones which disappear in these directions, it seems certain that, so far as 

the immediate region is concerned, the marine invasion came on it from the northeast and 

extended progressively southward and westward. 

In Clinton County, where the formation is thickest, the. basal portion is rather sharply 

differentiated from t,he rest in character, and this portion has co;nsiderable thickness, though 
CAMBRIAN AND LOWER ORDOVICIAN. 121 

how much and how large. a part of the whole thickness it constitutes, is wholly uncertain. The 

writer was the first to show this, and it has lately been reaffirmed by Van Ingen. This portion 

·consists in part of coarse basal conglomerates, in part ·of poorly indurated sand beds of small 

durability, 'and in smaller part of thoroughly indurated sandstones. It is nearly everywhere 

characterized by a considerable feldspar c·ontent, in addition to the quartz, and this feldspar 

is for the most part fresh·. Considerable magnetite also appears in places, along with grains 

of garnet aitd occasional zircons.' The ro~k has therefore an arkose character in this portion, 

while above it is prev.ailingly of pure quartz sand. Red is the predominant color of the base; 

and there is but little white sandstone in it, while above the latter is the prevailing color. As 

a general proposition, a feldspar content and a prevalence of red beds go together and are 

certain signs of the basal portion. 

Basal conglomerates are a prominent feature in Clinton Cou~ty wherever the proper 

horizon is exposed. For the most part these are not extra coarse, the larger pebbles seldom 

exceeding an inch in diameter. The pebbles are prevailingly or exclusively of quartz, derived 

from the quartz !Veins of the pre-Cambrian rocks1 and are embedded in a. coarse sand matrix 

in which there is a large feldspar and considerable magnetite content. Along most of the 

northern border the general lack of pebbles of the underlying rocks, which are mostly Saranac 

gneisses, is indicative of quite prolonged wear of the material, so that only the extra-resistant 

pebbles of vein-quartz origin were sufficiently durable to persist as pebbles. The undccaycd 

character of the feldspar grains of the sands in these conglomerates indicates that all soil and 

largely weathered rock had alrca(iy been removed and carried offshore to be deposited and that 

the waves were working on tolerably fresh rock, whose grinding to sand had to be performed 

oy water-action~alorrc,unaidcd~branrspeciai~weakness-dU:c-to~previous-wcathcring~. --~~--~~~~--~~~ 

In some few localities conglomerates indicative of much less vigorous wave a~tion arc found. ' 

These contain numerous pebbles of the underlying gneisses, often of large size and showing 

great variation in size, and quartz pebbles are much less conspicuous or lacking. These seem 

to be purely local deposits laid down in sheltered hollows in the pre-Cambric floor, whose presence 

is likely due to uneven depth of weathering of the floor rocks. It is in rocks such as these that 

the pebbles of diabase and syenite porphyry which demonstrate the pre-Potsdam age of thc13c 

dikes are found. Such conglomcra:tes arc much l_css resistant rocks than the commoner quartz-. 

pebble conglomerates, and present exposures usually show them in much disintegrated condition. 

* * * * * * * * * 

Very abundant also in the basal·portion of the formation are .beds of rapidly disintegrating, 

very red coarse arkose sandstones, made up mainly of quartz and feldspar grains and the whole 

much permeated with red hematite. 

* * * * * . * * * * 

Well-indurated red sandstones, such as those from the type locality at Potsdam, 'are not 

infrequent in the basal portion of the formation and arc numerously e~poscd at various localities on the north border of the Adirondacks in such situation as to indicate clearly their horizon. 

At Potsdam itself tl,J.e section is complicated by faulting, and the horizon of the red sandstone 

there can not be demonstrated, though inferentially it is low in the formation. Along with the 

red there is much hard glassy b~own sandstone, also containing fresh feldspars but lacking the 

hematite coloration of the red beds. Above, the reds become striped and mottled with white, 

forming a species of passage beds to the middle division. 

Van Ingen is the only observer who has undertaken to differentiate between the middle 

and upper portions of the Potsdam. He says: · 

"The middle pbrtion of the sandstone is made up of well-sorted materials, of finer grain, 

compactly cemented, and of white, steel-gray, or yellowish color, with very little or no feldspathic content. The grains of sand are both angular and rounded, with the former predominating. The layers arc more regular, though their surfaces are ripple-marked, and in section 

they are seen to be almost universally cross-bedded. · Pebbles arc found on ~he •surfaces of 

some layers of the middle portion, but unlike those of the upper portion they seem to have been 
122 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

of soft mud derived by erosion of contemporaneous sediments, cast on the beach at times of 

rough water and flattened and squeezed out by the subsequent pressure and consolidation of 

the superimposed sand deposits. 

"The upper portion of the formation has frequent beds of irregular laminated sandstone, 

with partings of greenish arenaceous shale. The shale surfaces are covered with fucoids and 

worm trails. Pebbles of shale and dolomite, which were hardened before the time of their 

entombment, are found embedded in the sandstone layers, and their disintegration causes cavities to form in the layers containing them. The dolomite pebbles become more abundant toward 

the upper horizons. In the upper levels frequent beds are composed of nicely rounded grains of 

clear quartz with a little cement that crumble to a sugary powder under the hammer. Rounded 

grains of quartz of a slightly larger size occasionally cover the upper surface of a layer of finergrained sandstone, and, being without cement, they stand out in relief above the surface with 

an appearance of having been sprinkled from a pepper pot." 

* * * * * * * * * 

The thickness of the Potsdam in Clinton County is unknown. The thickest measured 

section is .that in the A usable Chasm, but the section there is complicated by faulting and is by 

no means complete, all the basal portion being lacking. Walcott's measurement gives 350 

feet, and Van Ingen's "at least 455 feet" as the thickness here. In the Morrisonville well, with 

the drill resting at 1,250 feet in the Potsdam sandstone, at least 750 feet of the formation had 

been drilled through, and the bottom samples were of clear, glassy quartz sand, with no trace 

of the feldspars which characterize the basal portion, indicating that it had not been reached. 

From this record alone it seems perfectly safe to say that the formation has a thickness considerably in excess of that amount in Clinton County. The writer's estimate, based on the broad 

belt of outcrop in the northern part of the county, assigns a minimum thickness of at least 1,000 

feet to the formati-:m, with a likelihood that it is considerably in excess of that amount. 

* * * * * * * * * 

The paleontologic and stratigraphic work of Walcott and Van Ingen has shown. that the 

upper portion of the formation, through a thickness of some 350 feet, carries a sparse Upper 

Cambric fauna. With the exception of a few supposed tracks, of uncertain nature, no fossils 

have so far been found in all the remainder of the formation, and there is therefore an utter 

lack of paleontologic evidence as to its age, and the possibility that the lower portion may be 

older than the Upper Cambric must be conceded. But it seems to the writer that, fossil evidence being lacking, the formation as it occurs in New York is not susceptible of subdivision. 

The basal rocks grade into those of the middle division, as do those into the upper, and there 

is no marked structural break at any horizon which would warrant the assumption of any great 

difference in age between base and summit, or any marked pause in sedimentation. Prof. 

N.H. Winchell has long held and has recently reiterated the view that the typical Potsdam at 

Potsdam is much older than the upper, white, less-indurated beds, and he classes it in the middle 

Cambric and correlates it with a portion of the Keweenawan of the upper lake region. As 

above indicated, the writer's judgment is that any present attempt to divide the formation on 

the basis of age is premature and has but slender basis of fact, considering the lack of all 

evidence from fossils. 

As has been shown by many observers, the transition from Potsdam to Beekmantown 

sedimentation is not a sharp one but through a series of passage beds. Near the summit of 

the former, thin beds of gray dolomite make their appearance, interbanded with the soft white 

sandstones which prevail there, increase in frequency till they constitute half the mass of the 

rock, and finally prevail and cut out the sandstones altogether. The sandstone layers are characteristically Potsdam in appearance, and the dolomites as characteristically Beekmantown. 

There is no mixing of materials but rather a rapid alternation of two contrasted sets of deposition conditions. Walcott has measured a thickness of 25 feet of such passage beds along the 

Chateaugay. River and 70 feet near Whitehall. In the writer's judgment, the latter is much 
CAMBRIAN AND LOWER ORDOVICIAN. 123 

nearer the usual figure than the former. These beds are exposed at many localities along the 

northern border of the region, but seldom suitably for measurement of thickness. They seem 

usually of considerable bulk. 

Cushing's account of the Potsdam is followed in the report cited by a description 

of the overlying Beekmantown. In his latest studies, however, he distinguishes 

under the name "Theresa dolomite" the dolomitic beds which immediately succeed 

the Potsdam west of the Adirondacks and which he no longer regards as equivalent 

to the Beekmantown. Cushing 204b says: 

Theresa dolomite.-The Potsdam grades upward into a formation which consists of sandy 

dolomite layers and beds of weak brown sandstone which are mostly near the base and are quite 

like the upper beds of the Potsdam. The line between the two formations is drawn at the base 

of the first dolomite layer, but in all probability this is not a constant horizon over the district. 

The name given to the formation is mainly intended for local use and the necessity for its introduction arises from present doubt as to the exact equivalent of the formation elsewhere in the 

region. 

When fresh the dolomite is a hard and tough bluish-gray rock, which, however, quickly 

weathers to iron-stained sandy crusts. All ths beds are somewhat sandy. The most characteristic lithologic feature of the rock is the glittering calcite cleavages which appear on the freshly 

fractured surface. These cleavages run up to an inch in length, have a somewhat satiny luster, 

owing to the included sand grains, and are produced by the deposit of the calcite cement around 

the sand grains with similar crystallographic orientation-in other words, producing true sand 

crystals on a small scale. This same lithologic peculiarity is a feature of the so-called PotsdamBeekmantown passage beds farther to the eastward, and, so far as my observation goes, is 

confined to that horizon, not appearing in the Beekmantown above. 

In the lower portion of the formation the large Lingula previously mentioned is abundant, 

a gastropod which has not yet been determined occurs at all horizons, occasional cystid plates 

and traces of other fossils are found, and fucoidal markings are frequent on the surfaces of some 

layers. 

The general thickness of the formation over the quadrangle is from 60 to 70 feet. Like 

the Potsdam beneath, it thins to the west and apparently also to the south, though widespread 

sand deposits hide the decisive proof of the latter. In addition to this thinning because of 

overlap, it has also suffered erosion at its summit, owing to uplift (apparently slight) and wear 

during a lengthy time interval. For instance, it has a thickness of but 20 feet near the north 

end of Perch Lake, though recovering its normal thickness of 60 feet within a mile on each side, 

and the diminution in thickness is by the wearing away of the upper beds. Coincidently with 

this local thinning, the overlying formation thickens, showing basal beds which are lacking 

on each side and plainly owing their existence to the surface depression. 

For the description of the overlying Pamelia and higher formations, see Chapter IV (p. 185). 

The Potsdam sandstone and possibly the "Theresa dolomite" belong to the 

Saratogan or Upper Cambrian, formerly called the "Potsdam series." Walcott 

introduced the term "Potsdam series" in the large sense in 1891, but in 1903 he 

withdrew it in order to avoid confusion, and introduced Saratogan instead. Mter 

giving the reasons for the change he says: 858 

The type locality of the Saratogian is north and west of Saratoga Springs, N. Y. The 

section has, at the base, about 200 feet of evenly bedded, compact grayish to yellowish colored 

sandstone, that rests unconformably against or upon spurs or ridges of pre-Cambrian gneiss. 

At a locality 3 miles north of Saratoga Springs the sandstone is about 40 feJt in thickness; it is 
124 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

overlain by an oolitic limestone, 30 feet, and a dark-gray, evenly bedded limestone 50 feet in 

thickness. In this latter limestone the following fauna occurs: 

Cryptozoa proliferum. Billingsia saratogensis. 

Obolus (Lingulepis) acuminatus. Matthevia variabilk 

Platyceras minutisoimum. Dikelocophalus hartii. 

Platyceras hoyti. Dikelocephalus speciosus. 

Metoptoma cornutiformo. Ptychoparia calcifera. 

Metoptoma simplex. (A.) saratogensis. 

The Calciferous formation of the New York section rests conformably on the Upper Cambrian limestone. 

The formations now referred to the Saratogian are as follows: 

Type.-Sandstones and limestones of the south side of the Adirondacks, Saratoga County, 

N. Y., containing the Upper Cambrian fauna. 

Correlated.-Upper part of Cambrian limestones of Dutchess County, N.Y., and an unknown 

portion of the limestones of the "marble belt" of western Vermont. 

Upper part of shales of Tennessee (Knox), State of Georgia, and Alabama (Conasauga), 

and the lower part of the Knox dolomite. 

Upper part of the sandstones of the upper Mississippi Valley (St. Croix), Upper Cambrian 

limestones of South Dakota, Wyoming, Montana, and Colorado. 

Upper calcareous beds of the Cambrian of northern Arizona (Tonto) and central Texas 

(Katemcy). 

Upper Cambrian limestones and shales of Nevada (Hamburg), Idaho, and Montana (Gallatin). 

Black shales of the upper portion of the New Brunswick and Cape Breton Island Cambrian 

sections. 

Upper Cambrian shales and sandstones of Conception Bay, Newfoundland (Belle Isle). 

Recent contributions to the classification and interpretation of the Cambrian and 

Lower Ordovician of the New York province have been made by Grabau, 383 and also 

by Ulrich and Cushing. 822 (Seep. 184.) 

The general relations of the Cambrian of the Adirondacks in eastern New York 

and Vermont, and thence southward, were thus stated by Walcott: 854 

The strata referred to the Cambrian, on the western side of the Sutton Mountain anticlinal 

or the belt extending southwesterly from Quebec to the Vermont boundary, consist of more 

or less of the Sillery series, as found in the vicinity of Quebec, and, according to Drs. Selwyn 

and Ells, of a subjacent series of hard quartzite rocks interstratified with mica schist and black 

slate. The volcanic series, referred to the Cambrian in this region, indicates that during earlier 

Cambrian time the volcanic products were deposited contemporaneously with the included 

sandstones and slates, thus giving a phase of sedimentation not known elsewhere in the Cambrian of the Appalachian province. For this reason and from the fact that there is not any 

paleontologic evidence of the age of this volcanic series, I am inclined to think that it may 

belong to some pre-Cambrian terrane. 

Entering the northern end of the valley, between the Green Mountains and the Adirondacks, 

a sudden change occurs in the sedimentation. At the base the Olenellus fauna ranges through 

1,000 feet of magnesian limestone, and for 250 feet higher up in arenaceo-argillaceous shales. 

More or less arenaceous matter is associated with the limestones, and, about 2,000 feet above, a 

great lenticular mass of limestone occurs in the argillaceous shales, in which a fauna of Upper 

Cambrian aspect is found. At other localities this fauna occurs in the shales themselves and 

in a brecciated limestone at the same relative horizon. As far as known the upper portion of the 

Cambrian is formed of the shales. Proceeding southward and nearer the old coast line in Addison County, Vt., the limestone series is found to graduate into the Granular quartzite or the 

beach sand. Fro~ this point this shore deposit is traced without interruption to the Massachusetts boundary; and then, with more or less interruption, to the Hudson River below 
CAMBRIAN AND LOWER ORDOVICIAN. 125 

Poughkeepsie, N. Y. It is taken up again in New Jersey, and thence may be followed, with 

some interruption, across Pennsylvania to Maryland, whence it extends as an almost continuous 

formation across Virginia into eastern Tennessee and thence, with some interruption, into 

Georgia and Alabama. On all this long line it forms the basal member of the Cambrian; and 

wherever fossils have been found in it they belong to the Olenellus or Lower Cambrian fauna. 

The offshore or deeper-water deposits are represented by finer-grained saudstones, shales, 

slates, and limestones. In southern Vermont they form the roofing-slate belt that passes into 

New York, where the section comprises some 12,000 feet of shales, slates, and interbedded 

sandstones, with more or less calcareous matter, either as brecciated conglomerate or as thin-' 

bedded, intercalated limestones. These extend, with some change in their character and 

regularity of exposure, to the Hudson River in Dutchess County. Near Stissingville, in this 

county, the basal sandstone rests upon the pre-Cambrian and contains the Olenellus fauna. 

A few remains of the latter have also been found in the immediate superjacent limestone. 

The Middle Cambrian and Upper Cambrian faunas occur in bedded limestones. As the quartzite exposed on the eastern side of the limestones of the "marble belt" represents but a very 

small portion of the great series of shales, slates, etc., of the Cambrian on the western side of the 

"marble belt," it is probable that the lower portion of the limestone is of Cambrian age, the 

same as in Dutchess County. This observation also applies to the basal limestone in New 

Jersey and Pennsylvania, where there is very little thickness of shales between the basal quartzites and the limestone. 

The Beekmantown ("Calciferous") of the Champlain district was studied in 

detail by Brainard and Seely, 95 whose paper contains maps and local structure 

sections. They say: 

The term Calciferous was used by the older geologists of New York and Vermont to 

designate the strata between the Potsdam sandstone and the Chazy limestone. The lower 

boundary is well defined, as the Potsdam sandstone has been long recognized and carries a 

peculiar fauna. The•upper boundary, the base of the Chazy, is less definite; but we consider 

it to be certain strata of sandstone, from 30 to 40 feet in thickness, described in the "Geology 

of Canada," 1863 (p. 123), and found in the Champlain region in several localities below all 

other beds containing characteristic Chazy fossils. 

In our study of the rocks of the Champlain Valley we have been surprised at the development of the Calciferous formation--at its vast thickness, its variety of rock, and its abundant 

fauna. That the earlier geologists, who made explorations on this ground, Profs. Emmons, 

Adams, and Hitchcock, should have made such brief mention of this grand subdivision must 

be attributed to the fact that they had wide areas to examine and but brief time allotted them. 

The Calciferous is, moreover, a most difficult formation to decipher, because of its great thickness, the absence of fossils in most exposures, and the resemblance to each other of its various 

beds of magnesian limestone. 

In our study of these rocks every important exposure has been visited on the Vermont 

side of Lake Champlain from Philipsburgh to Benson, and most of those on the New York 

side. Instead of a thickness of 300 feet for the Calciferous, as estimated in the Vermont report, 

we find a thickness of 1,800 feet; instead of the four or five species of fossils there mentioned 

we find over a hundred species, many of which are as yet undescribed. , 

There are two localities in which the entire sequence of Calciferous strata can be seen. 

One of these is in eastern Shoreham, and was first discovered by Rev. Augustus Wing and 

referred to by him as "the Bascom ledge." (See Am. Jour. Sci., 3d ser., vol. 13, p. 343.) It is 

a great monocline 2 miles in width and 3 to 5 miles in length, in which all the Lower Silurian 

rocks are ·seen overlying at least 200 feet of Potsdam sandstone. The strike is somewhat 

sinuous and the dip varies from 9° E. to 38° E., but there are no abrupt changes in either 

except at the northern or western borders. Much of the rock is covered with soil, but 

exposures on hillsides, along watercourses, and in escarpments of cliffs are sufficient to reveal 

the character and thickness of all the members of the Calciferous formation. * * * 
126 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The strata of the Calciferous seen at various exposures in this monocline are as follows, in 

ascending order: 

Division A. 

Dark iron-gray magnesian limestone, usually in beds 1 or 2 feet in thickness, more or less siliceous, 

in some beds even approaching a sandstone. Nodules of white quartz are frequently seen in 

the upper layers, and near the top large irregular massee of impure black chert, which, when 

the calcareous matter is dissolved out by long exposure, often appears fibrous or scoriaceous. 

Feet. 

Thickness.... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310 

Division B. 

Dove-colored limestone, intermingled with light-gray dolomite, in massive beds; sometimes for 

a thickness of 12 or 15 feet no planes of stratification are discernible. In the lower beds and 

in those just above the middle the dolomite predominates; the middle and upper beds are 

nearly pure limestone; other beds show on their weathered surfaces raised reticulating lines 

of gray dolomite. Thickness ............................................................. 295 

Division C. 

1. Gray, thin-bedded, tine-grained calciferous sandstone, on the edges often weathering in fine 

lines, 40 or 50 to the inch, and resembling close-grained wood. Weathered fragments are 

frequently riddled with small holes, called 8colithus minutus by Mr. Wing .......... _..... 60 

2. Magnesian limestone in thick beds, weathering drab ........................................ 100 

3. Sandstones, sometimeB pure and firm, but usually calciferous or dolomitic ............. _ _ _ _ _ _ 70 

4. Magnesian limestone like No.2, frequently containing patches of black chert._. ____________ 120 

Thickness of C ......... _ .. ______ ..... _ ... _ . _ . _ .............................. ______ . . 350 

Division C is followed in ascending order by division D, which Whitfield 

assigned to the Chazy. (Seep. 187, Chapter IV.) Ulrich, however, regards division D as the most typical part of the Beekmantown. As observed by Brainard 

and Seely, whose section Cushing 203b reprints with approval, division D is made 

up as follows: 

Feet. 

Blue limestone in beds 1 or 2 feet thick, breaking with a flinty fracture, often with considerable 

dolomitic matter intermixed, giving the weathered surface a rough curdled appearance; becoming more and more interstratified with calciferous sandstone in thin layers, which frequently 

weathers to a friable, ocherous rotten stone................................................ 80 

Drab and brown magnesian limestone,, containing also toward the middle several beds of tough 

sandstone................................................................................ 75 

Sandy limestone in thin beds, weathering on the edges in horizontal ridges 1 or 2 inches apart, 

givmg to the escarpments a peculiar banded appearance. A few thin beds of pure limestone 

are interstratified with the siliceous limestone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 

Blue limestone in thin beds, separated from each other by very thin rough slaty layers, which 

protrude on the weathered edges in undulating lines. The limestone often appears to be a 

conglomerate, the small inclosed pebbles being somewhat angular and arenaceous ............. 100 

Thickness of D ...................................................................... 375 

E. Fine-grained magnesian limestone in beds l to 2 feet in thickness, weathering drab, yellowish, or brown. Occasionally pure limestone layers occur, which are fossiliferous, and 

rarely thin layers of slate. Thickness ...................................................... 470 

Cushing continues: 

Cassin formation.~ In the upper part of division D and in division E are numerous fossiliferous horizons carrying a rather abundant fauna. These beds are confined to the Champlain Valley, so far as the immediate region is concerned, and have therefore the same restricted 

distribution as the following Chazy. In discussing Brainard and Seely's paper, Prof. Wbitfield 

recognizes and emphasizes this point and the considerable differences bytween these upper beds 

and the ordinary sparingly fossiliferous character of the normal Beekmantown. He urges the 

similarity of the fauna to that of the Quebec.group of Canada, argues that these beds have 

more natu~al affinity with the Chazy than with the Beekmantown, and that they should either 

be placed with that formation or else considered as distinct from either and given a separate 
CAMBRIAN AND LOWER ORDOVICIAN. 127 

name, "as Fort Cassin, or Philipsburg formation, or any other appropriate name." a This 

seems to the writer not only as eminently proper but really a necessary procedure. The 

thickness and importance of this group, consisting of the upper 220 feet of division D and 

the whole of E, is such as definitely to warrant its separate mapping in the Champlain region, 

and the writer proposes the name "Cassin formation" for it, to make Whitfield's suggestion 

more precise and definite. 

L 12. SOUTHWESTERN MONTANA. 

Peale originally described the Cambrian of the Gallatin section in southern 

Montana and furnished details to Walcott, 854a who writes as follows: 

The Gallatin section of the Cambrian includes 1,250 feet of strata, of which 835 feet are 

'limestone, resting upon 415 feet of sandstone. Conformably subjacent to the latter, there are 

5,000 feet of alternations of conglomeratic micaceous sandstones, with bands of siliceous limestones and indurated clay shales, referred to the Algonkian by Dr. A. C. Peale.b 

A more detailed manuscript section, that Dr. Peale kindly prepared at my request, is as 

follows: 

Gallatin limestones, 835 feet: 

Pebbly limestones, 145 feet. Fossils, Leptaena melita, Ophileta sp. ?, Triplesia calcifera, Ptychoparia sp.?, Ptychoparia (E.) affinis. 

Dry Creek shales, 30 feet. 

Mottled limestones, 160 feet. Fossils, Ptychoparia sp. ?, Hyolithes sp.? 

Obolella shales, 280 feet. Fossils, Obolella sp.? 

Trilobite limestones, 120 feet. Fossils, Lingulella sp., Acrotreta gemma, Kutorgina sculptilis, 

Agnostus bidens, Hyolithes gregaria, Olenoides serratus, Ptychoparia gallatinenses, Bathyuriscus? haydeni. 

Gallatin sandstones, 415 feet: 

Gallatin shales, 290 feet. Fossils, Lingulella sp. ?, Hyolithes sp. ?, Ptychoparia sp.? 

Gallatin quartzite, 125 feet. 

In the report just quoted ·walcott expressed the view that the .5,000 feet of 

strata beneath the "Gallatin sandstones," which Peale assigned to the Algonkian, 

might be Cambrian and equivalent to the Bow River group of Canada. But in 1909 

he found that only the upper part of the Bow River is Cambrian, and it is separated 

from the major part by an unconformity. Most of the Bow River is therefore preCambrian, and the equivalent in Montana is the same. 

The Gallatin sandstones of Peale in the above section were later called by him 

Flathead formation, but the name Flathead is now restricted to the basal quartzite, 

and the overlying shales have been named Wolsey shale. The latter two formations 

and the overlying limestone were measured in detail on Crowfoot Ridge in the 

Yellowstone Park by Iddings and Weed 393 and the result is given in their monograph on the park. 

In the same volume Walcott 393b describes the Cambrian faunas from these 

formations. He finds thatThe Cambrian fauna of the park includes 10 species that are referred to the upper division 

and 21 that are referred to the middle and lower divisions of the Middle Cambrian fauna. 

The Middle Cambrian fauna * * * is more intimately related to that of the Black 

Hills and the upper Mississippi Valley in Wisconsin and Minnesota than to the Middle Cambrian 

fauna of Nevada or British 'Columbia. There are no indications of the Lower Cambrian or 

Olenellus fauna. The upper-division fauna is also strongly related in its Brachiopoda to the 

Mississippi Basin fauna. 

a Whitfield, R. P., Observations on the fauna of the rocks at Fort Cassin, Vt., with descriptions of a few new species: 

Bull. Am. Mus. Nat. Hist., vol. 3, 1890, pp. 27-28. 

b Tenth Ann. Rept. U. S. Geol. Survey, pt. 1, 1890, p. 131. 
128 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The Middle Cambrian series is well developed and somewhat diversified around 

the Little Belt Mountains. Weed 869 distinguished the following: 

Middle Cambrian: Feet. 

Yogo limestone.......................................................................... 70 

Dry Creek shale.... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 

Pilgrim limestone...................................................................... 80 

Park shale ............................................................................. 800 

Meagher limestone..................................................................... 60 

Wolsey shale ........................................................................... 150 

Flathead sandstone.......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 

With reference to the above statements, Ulrich comments (personal note): 

The series of rocks in Montana and Wyoming from the base of the Flathead quartzite to 

the top of the Gallatin limestone seems essentially equivalent to the Cambrian sections in central 

Texas, Oklahoma, Missouri, and Iowa. In each case we have a good Upper Cambrian sandstone 

followed, except in the far Northwest, by younger sandstone and dolomites. As to the base of 

the Cambrian, it is a question if at any of these localities any Middle Cambrian (like that in 

the Great Basin or like the Acadian of the East) is present. · 

The following description of the Cambrian formations in the Philipsburg quadrangle, Montana, and the discussion of their correlation are condensed from the 

description in an unpublished paper on the geology and ore deposits of that quadrangle, by F. C. Calkins, and from the unpublished folio on the quadrangle, by the 

same author. -

The Flathead quartzite is composed of more or less vitreous quartzite with an average 

thickness of about 200 feet. It lies unconformably upon pre-Cambrian red shales and sandstones equivalent to the Spokane shale of the typical Belt section. The evidence of this unconformity, whose importance was long ago established by Walcott, is especially clear in the Philipsburg district. Near the head of Rock Creek, in the Anaconda Range, a cliff exposure shows the 

base of the Flathead resting on the Spokane with an angular discordance of about 30°. On a 

branch of Lost Creek, about 8 miles northwest of Anaconda, a slighter discordance is displayed, 

and here the base of the Flathead is locally a coarse conglomerate of well-rounded pebbles of a 

quartzitic sandstone identical with that which forms the immediately underlying Spokane beds. 

Due probably to beveling in the erosion interval preceding the deposition of the Flathead are the 

great and rapid variations in the thickness of the Spokane formation. This is at least 5,000 feet 

thick in the gorge north of Georgetown Lake, while at the head of Mill Creek, 13 miles southeast, 

the Flathead is separated from the Newland limestone by only a few scores of feet of the Spokane formation. There is likewise a great diminution in the thickness of the Spokane between 

the northwest corner of the quadrangle and the center of its northern margin. The uplift that 

initiated the beveling seems therefore to have been relatively greater to the eastward. 

There is some evidence that a shore line of the Flathead sea traversed the southeast part 

of the quadrangle. In the locality near the head of Mill Creek where the Spokane is thinnest, 

the Flathead quartzite is irregular in thickness, much thinner on the whole than in most other 

places, and at one point was seen to taper to a knife-edge, leaving the superjacent Silver Hill 

formation in direct contact with the Spokane. The locality is, however, one of complex folding 

and thrust faulting, and the possibility of the thinning out of the quartzite by faulting nearly 

parallel to stratification planes is not absolutely excluded. 

The Silver Hill formation is here on the average about 400 feet .thick. A ma;cimum thickness of 700 feet was observed near the head of Rock Creek, in the Anaconda Range, but this 

dwindles to about 150 feet within 10 miles eastward. Its lower part consists mainly of darkgreenish, rather siliceous shales, the upper part of calcareous shales and thin-bedded limestones. 

It shows rapid gradation into the Flathead quartzite below and the dolomites above. 
CAMBRIAN AND LOWER ORDOVICIA!'I! 129 

In the vicinity of Silver Hill, about 12 miles west of Anaconda, where the best exposures 

occur, a threefold subdivision of the formation can be made; it here comprises in descending 

order: 

Feet. 

Shales, calcareous, strongly banded in brown, whhe, and green, interbedded whh laminated 

limestone ...................................................................... _ ..... _ 90 

Limestone with thin brown siliceous laminre about l inch apart............................. 120 

Shale, dark green, not noticeably calcareous, with a 3-foot intrusiye sheet of clark igneous rock 

near the base ... _ ...... _ ................................................ _.............. 120 

330 

In f!laces, as near Princeton, the_se rocks are very poorly exposed and here not even a twofold subdivision can be actually made on the ground. The middle and uppermost divisions 

can rarely be separated. The thin-bedded rocks between the Flathead and the Hasmark therefore constitute a convenient stratigraphic unit. 

The Paleozoic rocks above the Silver Hill formation consist preponderantly of thick 

limestone strata, which are separated by relatively thin shales. The first two of the calcareous 

strata, "\\>--ith the shale that parts them, are mapped as the Hasmark formation. It comprises 

a basal member chiefly of blue-gray dolomite, a medial member of dark shales, and a top 

member of white fine-grained dolomite. The highly magnesian character of the highest and 

lowest members is apparently not shared by the supposedly equivalent Pilgrim limestone. 

The lower dolomite is about 600 feet thick; the upper about 350 feet. The thickness of the 

medial shale member varies widely. Its maximum, attained in the southern part of the quadrangle, is about 150 feet; at Philipsburg it is virtually absent, although a few fragments of 

shaly rock are locally found at the horizon separating the gray from the white dolomite. On 

Boulder Creek, also, near the northern boundary of the quadrangle, this horizon is marked by 

only a few feet of shaly limestone. The shale has yielded a few imperfect shells like Obolus. 

The upper and main part of the Red Lion formation has a very peculiar lithologic character, not shown by the corresponding beds farther east. It consists of gray, drab, and white, 

rather thickly stratified limestones, whose bedding is marked by closely spaced laminm of 

siliceous or argillaceous material, about one-fourth of an inch in average thickness, which 

project in relief on the weathered surface. These are invariably wavy or crinkly, and locally, 

where they constitute the greater part of the rock, they anastomose so that the limestone forms 

little isolated lenses :flattened parallel to the bedding planes. a 

The lowest part of this peculiar limestone is the most siliceous and shaly, and it may 

roughly be said to grade downward into the lower member, consisting of black shale and thinbedded magnesian limestone, without the cherty banding. This member has a thickness of 

only about 15 feet on the west side of Cable Mountain, but although it is rarely well exposed, 

it is apparently two or three times as thick in some other sections. 

Fossils were collected from the upper part of the Red Lion formation by Mr. Kindle in 

1907 and submitted to Secretary Walcott, of the Smithsonian Institution. In a lot from Rock 

Creek, in the western part of the Anaconda Range, he found Billingsella coloradoensis Shumard 

and Anomocare sp.; in a lot from the vicinity of Princeton, the same forms together with 

Cyrtolites sp. and Agraulos sp. All the specimens, according to Dr. Walcott, b "are of Upper 

Cambrian age and therefore correspond to the Y ogo limestone." 

Correlation of Cambrian formations.-The ascription of the series above described as a 

whole to the Cambrian depends on (1) the unconformity at the base of the lowest quartzitic 

member which can reasonably be correlated only with the widespread unconformity at the 

base of the Flathead, the lowest Cambrian formation of the known Montana sections, and (2) 

the presence of Upper Cambrian fossils in the limestone of the Red Lion formation. Thus 

a The structure of this rock is very similar to that of the Abrigo limestone, illustrated in "Geology and ore deposits 

of the Bisbee quadrangle," by F. L. Ransome (Prof. Paper U.S. Geol. Survey No. 21, 1904, Pl. VI, B). 

b Letter to F. C. Calkins, June 3, 1908. 

48011°-12--9 
130 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

the identity of the Flathead is clear, and the limestone of the Red Lion is probably equivalent 

to the Y ogo, the highest Cambrian formation of the central Montana sections. 

The age of the intermediate members of the series is more obscure, but tentative correlation may be based on the following considerations: There is in the Philipsburg Cambrian and 

in that of the Little Belt Mountains and the Livingston region a basal sandstone or quartzite, 

overlain by alternating shales and limestones that constitute more or less definite stratigraphic 

units. It is a reasonable supposition that considering only relatively thick and homogeneous 

strata, the lowest shale in the Philipsburg section corresponds to the lowest shale in the Livingston section, the lowest limestone in the one to the lowest limestone in the other, and so on. 

On this assumption, the most probable correlatio~ seems to be the following: 

Tentative correlation of f!ambrianformations. 

Philipsburg quadrangle. Little Belt Mountains. 

R dL" f . {Uppermember ............ --------------------Yogolimestone. e Ion ormatwn.-------------------------- Lower memhf>r-- -- --- -- --- - - - --- --- - ---- -----Dry Creek shale. 

Hasmark formation _____ • __________________ . _ . _ . _ . _______________ . _____ .. __ . _ ... ___ ...... _ . Pilgrim limeston<>. 

{

Shale and laminated limestone ..... _. ___ ...... Park shale. 

Silver Hill formation ........ _._._._ .. _ ....... Laminated limestone ........... _ ... _____ ...... Meagher limestone. 

Green shale .......... _._ .... _ .. _ ....... _ ...... Wolsey shale. 

Flathead quartzite .. _ .. _____ ._ .. ________ . _. _. _______ . ___ .... __ . _ ... _____ ......... _ ....... _ .. Flathead quartzite. 

There is not, however, a sufficiently detailed resemblance between the Philipsburg section 

and those farther east to make a correlation so largely lithologic wholly safe. The Pilgrim 

limestone, for example, has not been described as magnesian and had it been as obviously so 

as the Hasmark, the fact would hardly have escaped notice; the few specimens in the National 

Museum do not appear magnesian. The peculiar laminated limestone of the Red Lion formation, again, does not seem to resemble the Y ogo. A real correlation between the Philipsburg 

and other sections is hardly possible before more Cambrian fossils have been found about 

Philipsburg, and strata actually traced from one region to another. There is reason to believe 

that when both these things have been accomplished, formations equivalent in the usual senses 

may prove to be not quite contemporaneous. The highest limestone in the Philipsburg quadrangle has a fauna of younger facies than that in the Little Belt Mountains, and the Flathead 

quartzite contains older fossils in the more easterly parts of Montana than in the more westerly 

parts. It may be that for each or for several of the epochs of the Cambrian period the controlling conditions of deposition were initiated at the east and gradually invaded more and 

more westerly areas-that there were, in fact, successive westward transgressions. 

L 18-19. ST. LAWRENCE VALLEY. 

In the valley of the St. Lawrence it is necessary to distinguish the formations of the Ottawa Basin and its northeastern extension to Quebec from those of 

the region lying farther southeast. The two are separated by the St. LawrenceChamplain thrust and the stratigraphic sequences are unlike, as are the facies of the 

formations and faunas. (See Chapter IV, pp. 196-206.) 

In the Ottawa Basin and thence past Montreal the Cambrian is represented only 

by the overlapping littoral deposit of the Potsdam (Upper Cambrian) sandstone. 

The Lower Ordovician Beekmantown or "Calciferous" succeeds. The characteristics 

of these formations and the enumeration of their fossils are given according to Ami 

in the tables quoted in Chapter IV (pp. 200 and 201). 

Logan's original descriptions 544 remain the most satisfactory concerning the 

details of character and occurrence in Canada. In so far as they relate to the 

stratigraphy of the formations in New York, they are replaced by Cushing's recent 

work. (See pp. 120-123.) 
CAMBRIAN AND LOWER ORDOVICIAN. 131 

The later reports of the Canadian Survey, particularly those by Ells, contain 

many statements and descriptions relating to the Potsdam and "Calciferous." 618a 

The Cambrian terranes of the region southeast of the St. Lawrence-Champlain 

fault were described by Logan as part of the "Quebec group." They are now 

comprised under the terms Levis and Sillery. Their typical character in the vicinity of Quebec is summarized by Ami in the table quoted on pages 202-203. 

The "Quebec group" was established by Logan, 544g who described the strata 

in the vicinity of Quebec and gave a detailed section, which is here included as an 

account of the rocks, though no longer accepted as a correct interpretation of the 

succession: 

At the upper end of the island of Orleans, on the northwest side, between high and low 

water marks, there are exposad about 500 feet. of black graptolitic shales, such as belong to the 

Utica and Hudson River formations, dipping southeast 50°; resting upon which is a series of 

different strata, dipping in the same direction, and at the same angle with them; the contact 

between the two being visible. After a short distance across the measures, undulations occur. 

The effect of these on the distribution of the beds has been partially ascertained, round the 

upper end, to the southeast front of the island, and for several miles along it. The following 

is the sequence of the strata; the beds are, however, in some places so corrugated and broken 

that the measurements here given can only be taken as rude approximations to the truth. 

1. Green calcarea-magnesian shale, weathering to a yellowish or reddish brown, interstratified 

with thin bands of purplish-gray argillaceous shale. Some of the magnesian shales are 

nearly grass-green, and the surfaces of most of the green beds are marked with fucoidlike forms of purplish gray; the green shales hold about 20 per cent of dolomite. The 

Feet. 

mass is strong and offers considerable resistance to weathering influences................. 100 

2. Gray argillaceous shale, much softer than the magnesian shale........................... 100 

3. Gray limestone conglomerate; the rounded masses are chiefly of gray limestone; the matrix 

in many parts weathers to a brownish color and is probably dolomitic. Fossils occur, 

some of them replaced by silica, but those as yet obtained in this locality are too obscure 

to be determined; the band in some parts appears to break into lenticular patches........ 10 

4. Green yellow-weathering calcareo-magnesian shale with gray argillaceous bands of the same 

character as No. 1................................................................... 100' 

5. Gray soft argillaceous shale............................................................ 200 

6. Yellowish-gray dolomite, weathering orange-brown. It holds occasional masses of ash-gray 

limestone and in some parts of its thickness a multitude of pebbles of quartz as large as 

peas, and becomes toward the top a dolomitic sandstone................................ 70 

7. Gray fine soft argillaceous shale, with compound graptolites .(Phyllograptus typus) about 

30 feet from the summit ................................. ,............................ 170 

8. Gray limestone conglomerate; the matrix in some parts weathers to a reddish brown, being 

dolomitic, and contains large concretions of carbonate of lime in concentric fibrous layers 

like travertine. The band holds fossils in some places.................................. 35 

9. Gray fine soft shale, with occasional bands of sandstone weathering brownish, none of them 

over 6 inches; the bands of sandstone increase in number toward the top................ 50(} 

10. Olive-green argillaceous shale, striped with purplish-gray bands . . . . . . . . . . . . . . . . . . . . . . . . . 70(} 

11. Olive-green arenaceous shale, with disseminated soft grains of a green mineral, resembling 

glauconite and approaching it in composition. In the upper part of the deposit the shale 

contains so much grit as to become almost a sandstone; and within about 100 feet of the 

top it assumes a red color, in one or two bands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400 

12. Yellowish-white limestone conglomerate; the matrix assumes a dolomitic aspect in some 

parts; the rounded masses or bowlders are occasionally 1 or 2 feet in diameter, and some 

parts of the bed hold fossils... . . .. . .. . .. .. .. .. . . . . . .. .. . . . . . .. . .. . .. .. .. .. . . . . . . .. . .. 10 

13. Gray, drab-weathering sandstones, in general slightly calcareous, interstratified with gray 

argillaceous shales; some of the sandstone beds toward the bottom are 3 or 4 feet thick 

and hold occasional calcareous pebbles. The sandstones become thinner ascending, and 

then the shales prevail; but these become by degrees more and more arenaceous, and a 

band or two about 200 faet from the top assumes a red color............................ 400 
132 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

14. Gray limestone conglomerate; the matrix, weathering to a brown in some parts, is probably 

dolomitic............................................................................ 30 

15. Gray, drab-weathering sandstones and shales, the sandstones slightly calcareous........... 300 

16. Dark-gray and green shales, with thin bands of gray quartzite and occasional thicker beds 

of drab-weathering sandstone, some of them being lenticular masses; the dark shales 

appear in some parts to pass into black................................................ 900 

17. Red and green shales, the red prevailing, interstratified with occasional thin layers of gray 

hard sandstone or quartzite, and a few of gray hard limestone; some of the bands of shale 

are of a deeper red than the general mass, approaching a maroon color. Toward the top 

of the equivalents of these shales, at Capo Rouge, there occur a small Lingula and Obolella 

pretiosa; the thickness of the deposit is from 1,500 feet to ............................. 1,000 

5,02.5 

The strata from 1 to 17 are in ascending order, provided they are not inverted, of which 

we have no evidence unless it be the occurrence of an Obolella [not Obolella Walcott] in the 

red shales. Several species of this genus occur in the Potsdam group, and one in what is considered the equivalent of the Calciferous portion of the Quebec group, at Troy, in New York. 

The genus being only recently established, it is not yet certain of what value it may be in determining the horizon. For the purposes of generalization, in describing the Quebec group, the 

series will be considered an ascending one; not so much, however, with the view of asserting the 

order of the strata as to render more intelligible the facts connected with their geographical 

distribution. 

It has since been shown that the sequence is inverted and also that errors in 

correlation arose from the failure to distinguish between fossils collected from the 

pebbles of the limestone conglomerates and those from the matrix. The extension 

of the term "Quebec group" to strata of widely differing ages led to its abandonment. The long controversy which led to this result and the detailed facts as 

finally ascertained are given in the report by Ells.311 Walcott 850 reviewed the 

evidence with Ells in the field and discussed Ells's report, adding thereto his own 

observations. He says: 

When first reading the description of the Point Levis rocks in 187 4, I was puzzled by the 

mixing of the faunas in the lists published by Mr. Billings and the statement made by Sir William E. Logan, that the fossils were from the matrix. On reaching Quebec, in August, 1889, 

I took the first opportunity to examine the lowest bed of limestone conglomerate back of 

St. Joseph de Levis and northwest of the Catholic Cemetery. Dr. Ells accompanied me. 

As we crossed the ridge I picked up a loose bowlder full of Potsdam or Upper Cambrian fossils. 

A second bowlder was found embedded in the matrix and then several more, some of which 

were 3 feet in diameter. The matrix is a hard gray impure limestone that occurs at this point 

in a solid band, that we traced 500 feet or more. In the matrix I found the Calciferous fauna 

was represented by Obolella sp.?, Orthis sp.?, Camerella calcifera Billings, Ecculiomphalus canadensis Billings, Ecculiomphalus intortus Billings, Ophileta complanata V anuxem, Pleurotomaria 

canadensis Billings, Pleurotomaria sp. ?, Orthoceras, 4 sp. undet., Ceraurus? apollo Billings, 

Ceraurus eryx Billings, Bathyurus bituberculatus Billings, Bathyurus quadratus Billings. 

In a bed of limestone 50 feet higher in the section I found, in addition to the preceding, 

the following: Bathyurus cordia Billings, Bathyurus oblongus Billings, Amphion caleyi Billings. 

In the succeeding band of limestone conglomerate Orthis porambonites Pander occurs. 

A large number of specimens were obtained from the bowlders embedded in .the limestone 

containing the fossils of Calciferous age, among which I have identified Camerella calcifera Billings(?), Agnostus americanus Billings, Dicelocephalus magnificus Billings, D. oweni Billings, 

D. belli Billings, Arionellus subclavatus Billings, Menocephalus? sedgwiclci Billings, and Illxnurus 

nlxnoides Billings (sp.). Other species occur, but the preceding list is sufficient to indicate the 

fauna of the Upper Cambrian or Potsdam zone. 
CAMBRIAN AND LOWER ORDOVICIAN. 133 

Dr. Ells accepted the view that the Calciferous fauna occurred in situ in the matrix of the 

conglomerate, and that the bowlders containing the Potsdam fauna were derived from preexisting strata. In the next band of conglomerate, above that which forms the ridge on the 

north side of the cemetery, the matrix also carries Calciferous fossils, and they are also abundant in the bowlders. In a search of two days I failed to find a Potsdam fossil at this horizon. 

From Dr. Ells I learned that nearly all the fossils described by ~1r. Billings came from the 

lower zone, and we found traces of extensive collecting. With these exact data I was enabled, 

at once, to correlate the lower belt of limestone and conglomerate with the central band of the 

Phillipsburgh section, where an identical fauna occurs 1,000 to 1,100 feet above the recognized 

Potsdam sandstone. 

This zone is 600 feet beneath the zone of "Maclurea ponderosa," where Mr. Billings placed 

the Levis conglomerates. The long period of uncertainty regarding the true mode of occurrence of the faunas in the Levis calcareous rocks is now terminated, and a fixed datum point 

secured for comparison with the known section on the shores of Lake Champlain. 

Dr. Ells quotes the greater part of the conclusions contained in Pro£. Charles Lapworth's 

instructive paper on the graptolites of the "Quebec group." a In this the graptolitic zone of 

the Levis shales is correlated with the typical Arenig of Great Britain and the Phyllograptus 

beds of Scandinavia. The graptolites of the Citadel Hill or Quebec City strata are correlated 

with the middle Llandeilo zone of Great Britain. 

The stratigraphic succession, as determined by Dr. Ells, is as follows: 

1. Black, green, and gray shales, with thick bands of grayish and sometimes yellowish-white quartzose sandstone and occasional thin bands of limestone conglomerate. 

2. Greenish, grayish, and blackish and occasional bands of reddish or purple shales, with thin layers of gray 

sandstone. Annelid trails (fucoidal markings of Ells) are numerous on the greenish shales. On the south shore of 

the St. I,awrence below Levis, and also on the south shore of the Island of Orleans, beds of conglomerate occur at 

about this horizon, in which the Lower Cambrian fauna occurs. 

3. Bright-red shales, with thin bands of greenish and gray shale. 

4. Red, greenish-gray, and black shales, with interstratified Sillery sandstones. Obolella pretiosa in the upper 

part, near Sillery, and on the south side of the river Obolella pretiosa, Protospongia jenestrata, Phyllograptus typus, 

Tetragraptus serra, and Lingula guebecensis. 

5. Levis shales and conglomerates of Point Levis. 

6. Black and grayish-striped or banded shales, with the black and graphitic shales and limestone of the 

Arthabaska and Somerset synclinal, the latter not appearing in the Quebec and Point Levis ~ections. 

7. The black or brownish bituminous shales and limestones of the city of Quebec and northwest side of the Island 

of Orleans. The contained fauna is of Trenton-Utica age. 

From the Cape Rouge section and the strata on the south side of the St. Lawrence, 

Dr. Ells concludes that the evidence afforded by the stratigraphy and the graptolites, determined by Pro£. Lapworth, is sufficient to refer the Sillery rocks of 1, 2, 3, and 4 of the section 

to the Cambrian system, and the Levis beds (5) to the Lower Ordovician. 

The thicknesses of the Sillery and Levis rocks are not given; but Dr. Ells told me that 

the measurements given by Logan were as nearly correct as could be determined. These were 

2,000 feet for the Levis shales and 5,000 to 6,000 feet for the Sillery series as now known. b 

The Obolella pretiosa ranges through from 1,500 to 2,000 feet of the Upper Sillery, and the 

lower conglomerate, of 2, occurs in the lower portion of this series. The Cape Rosier Dictyonema sociale zone is regarded as the lowest of the graptolitic zones, and to indicate the horizon 

of the Tremadoc terrane of Great Britain. The Cape Rosier beds are referred to the Upper 

Cambrian by Prof. Lapworth and Dr. Ells, but with our present knowledge of the Cambrian 

in America, I would refer them to the Lower Ordovician or to the Lower Calciferous. The 

occurrence of the typical Calciferous fauna within 100 feet of the base of the Levis series, at 

St. Joseph de Levis, points very strongly to considering the graptolitic fauna of the Upper 

Sillery to be of Calciferous age, if a comparison is made with the Phillipsburgh section. 

"Lapworth, ('harles, Report on some graptoliteK from lower Paleozoic rocks: Trans. Roy. Soc. Canada, 188(), pp. 

1()7-184. 

b This transfers to the Sillery a considerable portion of the strata originally referred to the Levis. 
134 'INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Dr. Ells refers the Sillery series to the Cambrian and in this I mainly agree with him, 

except that the upper portion is evidently a passage series between the Cambrian and OrdoVICian. On lithologic and stratigraphic eYidence the line would be drawn at the summit of 

the red shales. On paleontologic evidence, as furnished by the graptolites, I would include 

the upper portion of the Sillery red and green beds in the Ordovician, as I think they are above 

the typical Potsdam zone of America. 

It will be recalled that Dr. Ells stated that the Sillery beds rested unconformably upon 

the slates, quartzites, etc., which he refers to the Lower Cambrian. He mentions that, in this 

lower series, beds of gray subcrystalline limestone occur. It may be that we here have the 

source from which the limestone conglomerate of the Sillery was derived, which contains the 

Olenellus fauna. This would be in accordance with the mode of occurrence of the Olenellus 

or Lower Cambrian fauna to the southward, in Vermont and eastern New York. 

In this quotation Walcott states that he would refer the Cape Rosier beds to 

the "Calciferous" (Beekmantown) rather than to the Upper Cambrian as was done 

by Lap worth and Ells. 47• 

311c 

The limestones near Phillipsburg, which in the preceding quotation are assigned 

to the "Calciferous" (Beekmantown), were thus described by Logan: 544w 

A. 

Feet. 

l. Dark-gray and yellowish-white dolomites, weathering gray and yellowish brown...... . . . . . 400 

2. White and dove-gray pure compact limestones............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 

3. Reddish-gray, brown-weathering dolomites and black dolomites with some thin-bedded 

black limestones....... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 

700 

B. 

1. White and dove-gray pure limestones, with some yellow-weathering magnesian bands...... 120 

2. Dark-gray and black limestones, some of the beds magnesian...... . . . . . . . . . . . . . . . . . . . . . . . 120 

3. Dark bluish-gray thin-bedded nodular limestones, with thin layers of bluish-gray slate, 

probably magnesian; the surfaces of some of the beds weathering into a red or yellow 

ocherous arenaceous earth. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150' 

4. Black slaty thin-bedded nodular limestones, with two or three thick beds of purer limestone toward the base................................................................ 300 

5. Black limestones, some of them massive, weathering bluish gray; interstratified toward the 

bottom with black and dark-gray, yellow-weathering magneoian beds................... 350 

1,040 

The remainder of this section comprising divisions C and D is given on pages 

845-846 of Logan's report. 

The faunas of the Potsdam and "Calciferous" of the Eastern Townships of 

Quebec and of the Phillipsburg formation are listed by Ami. 14a 

L 19. MAINE. 

Certain shaly, calcareous, and quartzitic strata, which are highly altered, 

occur on the shores and islands of Penobscot Bay, where they have been studied 

in detail and provisionally assigned to the Cambrian by Smith, Bastin, and 

Brown/60a who say: 

The oldest rock of the Penobscot Bay region is the Ellsworth schist, which represents 

sediments probably of Cambrian or even pre-Cambrian age. The deposition of these arenaceous sediments was followed by ·dynamic action sufficient at least to inaugurate the changes 

of impure sand into a crystalline schist. This metamorphism is believed to have begun before 

the deposition of the next younger formation, inasmuch as the Ellsworth schist exhibits a 

much greater degree of alteration than any other rock in the quadrangle. 
CAMBRIAN AND LOWER ORDOVICIAN. 135 

The next epoch probably began in Cambrian time with the deposition upon the ocean 

bottom of muds and impure sands that are now represented by the Islesboro slate, with which 

the Calderwood slate is possibly to be correlated. This deposition presumably took place in 

moderately shallow water and not far from shore, but the position of the land masses which 

furnished the sediments is wholly conjectural. Gradually conditions became favorable for 

the deposition of the beds now represented by the Coombs limestone. The considerable 

amount of argillaceous material associated with the limestone, as well as the great variations 

in the purity of the limestone from place to place, may be taken as indicating shallow water 

and somewhat shifting currents. 

The changes which closed the period of limestone deposition were more rapid and of greater 

magnitude than those at its beginning and resulted in the depqsition above the limestone of 

sands and gravels of considerable purity which are now consolidated to form the Battie quartzite. The conglomerate beds of this quartzite show a somewhat impure quartzitic matrix in 

which are embedded pebbles of very pure quartzite. The fact that most of these pebbles are 

well rounded indicates that the rock from which they were derived was itself a well-indurated 

sandstone or possibly a quartzite. The massive quartzites have a composition about like that 

of the matrix in the conglomerates. Presumably these rocks represent shallow water or beach 

deposits which were subject to the sorting action of waves and currents. No quartzite beds 

which could have served as the source for such deposits are known in this part of the State, 

though they may occur buried beneath later formations. 

The parent formation need not have been wholly or even largely of quartzite, for the 

assorting and disintegrating action of waves and currents would suffice to separate more resistant quartzitic portions from less resistant shaly or calcareous materials. Certain beds, however, 

must have been very pure quartzite in order to furnish the clean, pure pebbles characteristic 

of the conglomerate. 

After the deposition of the Battie sands and gravels conditions for the deposition of muds 

were again restored and very extensive deposits were laid down, which are now represented 

by the Penobscot slate, the most widely outcropping and the thickest f?rmation of the region. 

The change is probably indicative of slight but long-continued subsidence. Within the adjoining Rockland quadrangle these muds were succeeded conformably by thick deposits of limestone, 

which is now thoroughly crystalline and of great economic importance in the production of 

lime. The presence of beds of limestone conglomerate at various horizons within this limestone 

formation indicates a shallow-water origin. 

Detailed descriptions of the formations are given in the Penobscot Bay folio. 

L 19. CARLETON AND YORK COUNTIES, NEW BRUNSWICK. 

The 11 slate belt" of southwestern New Brunswick comprises 11 Cambro-Silurian" 

(that is, Cambrian and Ordovician) and Silurian (11 Upper Silurian") strata, which 

are separated by a marked unconformity and are intruded by granite. Bailey 44a 

states the conditions and exact localities of the observations made in 1900 and 

concludes in part as follows: 

The general tendency of these observations has been to confirm the view * * * that 

while a Silurian age must be assigned to certain tracts, such as that in which fossils were 

found by Mr. Wilson, of the Geological Survey staff, 6 miles north of Canterbury, and that 

discovered by the writer in the settlement of Waterville, in th(~ parish of Southampton, yet 

the great bulk of the strata in the counties under consideration is, as previously supposed, of 

greater antiquity, being at least Cambro-Silurian or Ordovician (the age to which they had 

previously been assigned), if not even older. In seeking for evidence on this question a careful 

resurvey was made along the line where the supposed Cambro-Silurian or older rocks are met 

and overlapped by the fossiliferous Silurian rocks to the north, with the result that incontestible 
136 INDEX TO 'l'HE STRATIGRAPHY OF NORTH AMERICA. 

evidence of discordance is found along the whole length of that line. A new and well-marked 

instance of this was seen near the head of Eel River, in South Richmond, Carleton County, 

where heavy beds of bright-red slates, associated with amygdaloidal diorites, have afforded 

large fragments to the overlying Silurian beds. 

An effort was then made to determine the limits of the fossiliferous Silurian rocks previously discovered by Mr. Wilson. Fossils similar to those obtained by that gentleman, but 

occurring very sparsely, were collected at several points on Eel River, and strata exhibiting 

similar associations were followed fo~ 6 or 8 miles in the direction of the St. John River. Here, 

however, approaching the great granite belt, they not only failed to yield fossils but became 

so greatly altered as to be recognizable only with difficulty. In connection with this work 

the fossiliferous slates were found to be associated throughout with heavy beds of slaty conglomerates, the composition of which, though somewhat different from that of the South Richmond conglomerates, equally indicates their derivation from the supposed Cambro-Silurian 

and Cambrian strata. The course of these conglomerates is therefore provisionally regarded 

as marking, upon one side at least, the line of separation of the two systems in the parish of 

Canterbury. The southern side, owing to progressive metamorphism, can not be definitely 

assigned. 

So far, the conclusions reached * * * were based upon stratigraphical and lithological grounds only. But near the end of the season * * * new and most important 

evidence, tending to confirm the views already reached, was brought to light. This consisted 

in the discovery near the village of Benton, in Carleton County, of a band of very black, more 

or less graphitic slates, associated with gray and white quartzites and containing a few layers 

charged with large numbers of graptolites of the genus Dictyonema. Among these were some 

of large size (2! by 3 inches), showing both in their outlines and in the dimensions and structure 

of the polypary a very close resemblance to the form D. sociale or D. jlabelliforme Eichwald, 

occurring in rocks of Cambrian age on Navy Island, in the harbor of St.John, as well as at Matane, 

in the Province of Quebec. They are regarded as identical by Dr. H. M. Ami, after careful 

studies and comparisons, and Dr. G. F. Matthew (by whom the Navy Island form has been 

figured and described) is also disposed to adopt the same view. It would seem, therefore, that 

although the occurrence of a single fossil species is in itself very insufficient evidence upon 

which to determine and represent the horizon of a great group of strata, yet, when this is ·taken 

in connection with the stratigraphy of the region, pointing as it does in the same direct'ion, a 

strong presumption is established in favor of the Cambrian age of the beds yielding these forms. a 

L 20-22. NEW BRUNSWICK, CAPE BRETON, AND NEWFOUNDLAND. 

In 1900 Matthew contributed to a paper by Ami 16 the following statement of 

the succession of formations within a radius of 20 miles of St. John, New Brunswick: 

a For further details see Repts. Geol. Survey Canada, new ser., vol. 16, 1904, pp. 279-282A. 
Pre-Silurian rocks within 20 miles of St. John, New Brunswick. 

- ~----------

System. Terrane. Condition. Characteristic strata. Characteristic fossils. 

-~-----~--- -- ------,----~~ 

\ 5? Leptobolus grandis. 

J,ower Ordovician. 

Cambrian. 

Pre-Cambrian. 

Huronian "? 

Grenvillian. 

Laurentian. 

St. John 

group. 

l'ivision 3, "Breto- ' I!! 

nian." ·;s 

Division 2, Johannian. 

Division I , '' Acadian." 

s 

"' '"' -;:! 

~ p., 

Gray sandstone. 

Fine black shales. I r· Tetragraptus 4-brachiatus. · 3. Dictyonema flabelliforme. 

2. Peltura scarabeoides. 

Dark-gray shale. l. Parabolina spinulosa. 

Gray slates and flags. 3. Lingulella radula. 

Gray flags and sandstones. 2. ---starri. 

Gray flags and slates. 1. Worm burrows, etc. 

Black shale and conglomerate. 6. Dolichometopus acadicus. 

Fine black shale. 5. Paradoxides abenaeus. 

Dark-gray shale. {4· 3. 

P. eteminicus. 

P. lamellosus. 

Protolenus elegans. 

No fossils. 

Olive-gray shale and sandstone. 2. 

\Vhite quartzite. l. 

Purplish and green shale. Orthotheca, echinoderms. 

"0 Purplish-red sandstone. I Arenicolites, worm trails. I ~ Coarse reddish conglomerate. No fossils. 

Eteheminian. 

~-----~~~--I~~-~~~=~~-=-··-~=~1==-c~~-

Cold brook group, ell:. 

----~~----------

A~h rocks, felsites. 

Diabase, diorite. 

Clay slates and diori tcs. 

Limestones and quartzite;<. 

Mica schist, etc. 

Feldspathic gneiss. 

Chloritic gneiss. 

Quartz diorite (intruoive). 

~o fossils. 

{

Eozoonal fragments. 

Archreozoon, sponges. 

No fossils. 

No fossils. 

ll 

i} 

Thickness 

(feet). 

700 

750 

Locality. 

I}" Falls" at"St. J~n. Navy Island, St. John. 

King Street, St. John. 

Germain Street, St. John. 

King Street E, St. John. 

}Wright Street, St. John. 

Hasting's Cove, St. John 

County. 

Lock hom a r d, St John 

County. 

200 }seely Street, St. John. 

Kennebecasis River. 

Seely Street, St. John. 

-----1------------

-~~Caton's Island, County. 

1

-

l, 200 I Loch Lomond, !St. 

County. 

--~------- -===== 

King's 

John 

1

1

10, 000? / Carleton Heights. 

Loch Lomond HillH. 

--~-~-- -- cc.------------~ 

Howe's Road. 

} [Green Head. 

I .

l' 200? I. Douglas A venue, 

Green Head. 

Indiantown. 

(?) Fairville, etc. 

==~==============~=~====~--==~~=========== 

N. B.-A double transverse line indicates a marked discordance of stratification; a single transvers·e line indicates a discordance that is not so obvious. (This remark 

does not apply to the lines separating the subdivisions of the groups in the second column.) It will be seen that the terranes or formations do not always agree with those 

0 

l::Jj 

0 

0 

-< H 

0 

H 

p.. 

z 

of Europe----that is, the physical and paleontological breaks are not synchronous. t--1-

~ 

-l 
138 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Laurentian.-In the column of geological systems, beginning with tho oldest or Laurentian, 

Dr. Matthew has assigned certain crystalline schists of Indiantown and Fairville to this hori~ 

zon. These forin a part of tho Portland group (lower) of the reports bearing upon the geology, 

whereas the upper part of this group he classifies as Grenvillian, consisting of clay slates, 

norites, limestones, quartzites, underlain by mica schists. 

Huronian.-The Laurentian Archean rocks are succeeded upwards, as Dr. Matthew points 

out, by rocks of doubtful Huronian age, consisting of ash-rocks, felsites, diabase, diorite, such 

as are met with at Carleton Heights and Loch Lomond Hills, all grouped under the designation 

"Cold brook group." Both above and below this Cold brook group, as well as between the 

Laurentian of Indiantown and the Grenvillian limestones, slates, etc., of Green Head, Douglas 

Avenue, etc., a marked discordance of stratification occurs, which apparently indicates long 

lapses or intervals of time between them. 

Cambrian.-Above the Coldbrook group, and beneath the Cambrian or St. John group, 

Dr. Matthew describes and classifies certain purplish and green shales, purplish-red sandstones, 

and coarse red conglomerates, which are exposed on Caton's Island, in King's County, and at 

Loch Lomond, St. John County, under the term "Etcheminian." 

Between this Etcheminian and the St. John group the discordance of stratification is not 

as obvious as in the case of the preceding system with the Etcheminian. The fauna of the 

Etcheminian, however, is essentially a Cambrian fauna according to the writer. 

The Acadian, Johannian, and Bretonian constitute the three divisions which Dr. Matthew 

has established in the St.John group. The strata which they represent are 1,650 feet in thickness 

and consist of mudstones, with slaty cleavage, also sandstones and flags with conglomerate. 

The uppermost or Bretonian division of the St. John group, which is to be seen in the black 

graptolitic shales and sandstones of Navy Island and at the falls on the St. John River, near the 

suspension bridge, are by him referred to the Lower Ordovician. Many of the species which 

occur here are eminently characteristic of the Levis division of the Qutlbec group, in the St. 

Lawrence Valley. These strata correspond to tho Skiddaw and Arenig formations of England 

and Wales and to similar horizons in Scandinavia, France, and elsewhere. 

It is from the Cambrian or lower and mostimportant portion of the St. John group of rocks 

that Dr. Matthew has obtained material from which he described and illustrated the very 

extensive extinct fauna and flora of these old Paleozoic sediments. 

In 1904 Matthew 582 described the Cambrian as follows: 

Confining our attention to the areas where Cambrian fossils have actually been found, we 

note throughout this North Atlantic region the prevalence of volcanic deposits, or of red and 

green mud beds, in the initial period of Cambrian time. If the former are not actual lava 

flows, or the cores of old volcanic cones and ridges, they are the compacted ashes, mud, and 

stones from such a source. 

Resting on these volcanic deposits, though sometimes intercalated with them, are beds of 

sand and mud that easily show their relation to such a source as the volcano, by the fact that 

this sand consists largely of feldspathic particles, while the mud beds are pale-green or red 

accumulations of volcanic dust that have fallen into or been swept into tho sea. Hence it would 

appear that while the first volcanic eruptions occurred over land surfaces, the land soon sank, 

and the later ones were thrown into the sea. It is in the levigated material thus thrown into 

the sea, or swept into it by rivers, that we meet with the earliest organic remains of the Cambrian 

time. These levigatcd deposits are chiefly in the Etcheminian terrane and contain a very 

ancient group of Cambrian organisms. They also exhibit a cycle of deposits corresponding to 

that of the St. John terrane above them, for they have in the middle coarse sandy sediments, 

that separate two groups consisting largely of mud beds; of these the lower has conglomerates 

and sandstones intercalated, while the upper are found to contain flaggy sandstones. 

The principal sandstones, however, are in the middle member, which is comparatively 

barren of fossils but contains much diffused hematite, giving the rock a markedly red color. 

These beds also, like those of the corresponding stage of the St. John terrane, frequently show 
CAMBRIAN AND LOWER ORDOVICIAN. 139 

ripple-marked layers replete with worm burrows, worm trails, and other marks of a shallowwater origin. * * * 

In the outer areas of the Cambrian rocks of the Atlantic coast the Etcheminian terrane is 

easily traced by the prevailing red color, as well as by its fossils. In this outer zone fine-slates 

provail and there are beds of limestone, as may be seen in the Massachusetts and Newfoundland 

areas. In the inner zone (New Brunswick and Cape Breton) the sediments are coarser and 

limestones are wanting; it is in this inner zone that a middle member of sandstones and flags is 

most distinctly marked. 

The organic remains of this middle member are similar to those of the lower sediments, so 

that the Etcheminian rocks have only two faunas, an upper and a lower. The volcanic rocks 

beneath them have yielded a scanty fauna, which may not be more than a subfauna of the 

Lower Etcheminian. More material is required to determine the importance of this fauna. 

So far as the St. John terrane is concerned, it is clear that the basins we have now are but 

fragments of deposits that have been spread over large areas of the Atlantic coast, and there 

may be extensive tracts occupied by slates and flags so far metamorphosed that Cambrian 

fossils can not be recognized. The materials which make up the flags and slates of the Johannian 

division glisten with water-borne particles of mica, the sands are of uniform texture, and there 

are no traces of shore lines, though shallow-water beds abound. 

Also the Bretonian division, with its fine-grained dark-gray mud beds holding graptolites 

and the perfect preservation of its delicate organisms, indicates the presence of a water cushion 

of considerable depth above its muds, w:hen these were being deposited, a cushion which we 

can hardly think less than 1,000 feet deep. But a sea of this depth would have covered a wide 

area along the Atlantic coast, and we therefore infer that the known basins of Cambrian rock 

are but small fragments of the widespread mantle of sediments that covered this region at the 

beginning of Ordovician time. 

The group of organic remains of the outer zone of the Etcheminian rocks appears to differ 

widely from that of the inner. This may be because they do not come from the same time 

horizon; but it seems more likely to be due to some physical cause, either difference in the 

depth of the sea in the two zones, or paucity or abundance of sediment in the waters, or difference 

of temperature of the sea water in the two zones. Whatever the cause, olenelloid trilobites have 

not b{JCn recognized in the strata of the inner zone, while they are characteristic of the faunas 

of the outer zone. 

The Etcheminian, St. John, and Bretonian terranes are divided by Matthew 

into "assises" or faunal zones, and the faunas comprising 380 species are listed 

accordingly in the paper cited above. 

In earlier papers relating to the Cambrian and pre-Cambrian, Matthew had 

included the Etcheminian in the latter, as a formation underlying the "Lower 

Cambrian" (Olenellus zone). 

Walcott 857 b studied the sections both in New Brunswick and Newfoundland 

and reached conclusions differing from those of Matthew, which the latter subsequently accepted, namely: 

(a) The "Etcheminian" terrane of Matthew is of Lower Cambrian age. 

(b) The Olenellus fauna is older than the Paradoxides and Protolenus faunas of the Middle 

Cambrian. 

(c) The Cambrian section of the Atlantic province of North America includes the Lower, 

Middle, and Upper Cambrian divisions as defined by me in 1891. 

Walcott's conclusions are based on the following sections in part, and others 

to be found in his paper: 857a 

Smith Sound section.-On the northern shore of Smith Sound, east and west of Smith 

Point, the Cambrian rocks are well exposed along the shore. At Broad Cove, west of the point, 
140 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

the transition beds between the Upper Cambrian (Olenian) and the Middle Cambrian (Paradoxidian) arc concealed by the drift at the head o£ the cove. West o£ the cove the fissile and 

arenaceous shales o£ the Upper Cambrian are well exposed and contain Olenus. On the eastern 

side o£ Broad Cove the Middle Cambrian is exposed. The measured section begins with the 

dark argillaceous shales and is as follows: 

Middle Cambrian, downward: Feet. 

la. Dark argillaceous shales, with fragments of Paradoxides in the upper portion. At 45 

feet down the Paradoxides are abundant; also Acrothcle, Obolus (L.) ferrugineus, 

Pt~choparia, etc. At 110 feet down a 4-inch band of pinkish limestone carrying 

fragments of trilobites occurs. A roll in the strata comes in at this point and continues for a considerable distance along the shore. It starts between the two east 

wharves at Broad Cove and extends some distance east of the eastern point of Broad 

Cove .... __ .................................... · ............................. _. _ .. 110 

1h. Below the limestone greenish shale extends downward to a layer of reddish argillaceous 

shale 20 feet in thickness. No recognizable fossils were found in this bed._..... . . . . . 80 

lc. Pinkish nodular limestone in several layer.s, interbedded in reddish shale. Fossils: 

Paradoxides (undet.), Ptychoparia................................................ 4 

ld. Reddish-purple argillaceous shales with interbedded greenish-colored bands ........ 135 

This band of shales corresponds stratigraphically to the Protolenus zone of the Hanford 

Brook section of New Brunswick. A basalt dike cuts through the shales a few feet 

above their base. On the weathered surface it has the appearance of a massive sandstone. It is 3 feet 4 inches in thickness, is vertical, and the dip of its cleavage planes 

is almost coincident with the dip of the shales. 

le. Nodular limestones. A pinki3h layer 4 inches thick contains at base numerous fragments of trilobites and appears to be made up of a conglomerate formed of fragments 

of pinkish-colored limestone and purple shale, and dark iron- or manganese-stained 

nodules resembling a stromatoporoid-like growth, and a few small quartz pebbles.... 3 

The entire stratum is as follows: 

Inches. 

Dark nodular limestone ................................. ___ .. _ ..... 25 

Purplish-colored shale ................................ _. ___ .. _...... 2 

Pinkish limestone ...................................... __ . ____ . .. .. . 2 

Brick-red shale .......................................... _. ______ .. 3 

Pinkish conglomerate(?) limestone ............. _ ... _ ........... _ .. __ 4 

At the point of exposure on the shore this band is faulted down 15 feet to the west. It 

is exposed near the top of the bank on the eastern side of the fault, where its dip is 

lower than on the western side. 

The stratum 1e is taken as the base of the Middle Cambrian (Paradoxidian). It is the 

horizon indicated by Mr. Matthew in his diagrammatic section as the base of the Cambrian, and corresponds in stratigraphic position to the St. John quartzite of the New 

Brunswick Cambrian. 

One observes no difference, in either strike or dip, between the shales beneath this band 

of nodular limestone and conglomerate and the shales above it until one passes to the 

cast of the fault line that cuts through and breaks the band a few feet above the water's 

edge. 

Lower Cambrian (Etcheminian of Matthew): 

2a. Reddish-purple argillaceous shale with greenish shales in bands at irregular intervals 

and a massive band of greenish shale near the base. Dip near base 20° to 23 ° W.. . . . . 284 

At llO feet from the summit fragments of a large undetermined trilobite were noted. 

On the south side of Smith Sound, at Britannia Cove, Olenellus (H.) broggeri occurs 

at a horizon corresponding to 140 feet below the summit of the stratum. 

Near the ba'e of 2a the following fossils were found: 

Obolella atlantica. 

Hyolithes sp. 

Orthotheca sp. 

l\Iicrodiscus sp. undet. 

Olenellus (IIolmia) briiggeri. 

Solenopleura? bombifrons?. 

2b. Greenish-colored arenaceous lims.Jtone, pa>sing into an intraformational conglomerate 

formed of nodules of pinki3h limCJ.Jtonc mixed with fine sand and carrying numbers 

of fragments of trilobites.-------------- .................. __ ._._ ..... _. _____ ...... 1~ 

Pinkish-colored nodular limestones................................................. ~ 

FosJih: Fragments oftrilobitc.J and a small brachiopod. 
CAMBRIAN AND LOWEH ORDOVICIAN. 

Lower Cambrian (Etcheminian of ~fatthew)-Continued. 

2c. Reddish-purple to brick-red argillaceous shale _____________________________________ _ 

The following fo3sil3 ocvur in the central and lower portion~ of thi8 hand: 

Obolella atlantica. 

Microdiscus bellimargin,ltu~ S. & F. 

Microdiscn:l n. sp. 

Olcnellus (Ilolmia) bri.iggeri. 

Zacanthoides sp. undet. 

Agraulos sp. 

Micmacca walcotti. 

2d. Brick-red and pinkish nodular limestone in layers varying from 3 feet to 6 inches in 

Feet. 

56 

thickness. __ . ___________________________________________________________ .. _____ . 27 

This is one of the mo:Jt important horizons in the Llnn~r Cambrian of Newfoundland 

(Smith Point lim83tone). It is very persistent about Trinity Bay, and it occurs, 

although much thinner, at various exposures in Conception, St. Marys, and Placentia 

bays. The upper 24 feet at Smith Point is practically solid limestone layers. The 

lower layer of limmtone, l foot in thickness, is separated by 2 feet of reddish shale in 

which 3 inches of limestone occurs. 

Fossils: In the upper() inches o( the top layer of limestone numerous fragments of Olenellus (H.) broggeri and Solenopleura? occur. About 3 feet below this, in the next 

bed of lim83tone, immense numbers of Hyolithes princeps are found in association 

with tho fauna that marks thil limeJtone band wherever it is found. The following 

species were collected in a few houro: 

Iphido,tlabradorica (Kutorgina granulata M.). 

Fordilla troyensis. 

Scenella reticulata? 

Randomia aurorae. 

I!elenia bella. 

Orthotheca pugeo. 

Hyolithes princeps. 

Coleoloides typicalis. 

Hyolithellus micans? 

2e. Green argillaceous shale ................................................ _ ..... ____ . _ 2:J 

2f. Massive stratum of nodular limestsme, divided into 18 inches of a pinkish limestone and 

3 ket of purple to a pink mixed with purple argillaceous shale. Fossils: Coleoloides 

typical is ____ . __ .. ____ .... __ ... ______ . __ . _ . __ . _____ . _ . _____ ..... ____ ..... ____ ... _ 4~ 

2g. Green argillaceous shale in massive bands, with numerous small pinkish limestone 

nodules scattered irregularly on the line of bedding. At 51 feet from the base the 

limestone nodules increase in number and size and form the greater part of a layer 2 

feet in thickness. Above this the reddish-purple and green shales occur in bands 

varying in thickness __ . _____ ... _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 

Fossils: 

Hyolithes rugosus Matt.? 

Coleoloides. 

Urotheca pervetus Matt. 

Crustacean, n. g., n. sp. 

'2h. Reddish-purple argillaceom shales, with irregularly distributed bands of nodular limestone of varying thickness. A layer of nodular limestone 42 feet from the summit has 

12 inches of pinkish and reddish-purple limestone above, with 10 i!lches of greenish 

limestone below. In both layers numerous tubes of Coleolides occur. At 66 feet 

below the summit a secon.-1. band of nodular limestone 20 inches in thickness occurs. 

Thin layers of nodular limestone occur both above and below the two thicker bands 

mentioned. ______________________ ... ________________________ .. __________ · _____ .. 136 

2i. Green argillaceous shale, with a few thin layers of purple shale, also scattered layers of 

pinkbh-colored nodular limestone. Fossils: Annelid trails are abundant in some 

portions of the greenish-colored shales __ .. ______ .. ______ . _______ .. ___ ............ _ . 30~ 

2j. Reddish-purple shale, with layers of greenish and pinkish-colored limestone nodules 

scattered irregularly on the line of bedding. The nodular limestones are usually 

from 2 to 4 inches in thickness, but at 60 feet from the top a layer 12 inches thick occurs __ . ________________ .. _______________________________________ .... ___ . . . . . . 185 

The section is here cut off by the drift coming down to the water's edge. 

141 
142 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The nodular limestones of the Smith Point section are one of the most r~oticeable features 

of the lower portion of the section. * * * The only fossils found in the lower part of the 

section except annelid trails occur in the nodules. The bedding planes of the shale in the 

slate quarries on Smith Sound are clearly indicated, at nearly right angles to the eleavage, 

by the lines of scars left by the nodules. 

Base of Cambrian in Smith and Random sounds.-The base of the Cambrian is exposed 

at the slate quarries east of Tilton Head, on the north side of Smith Sound, in the synclinal 

basin formed of the Avalon and subjacent Cambrian rocks. The section, however, is not 

here complete. On the south side of Smith Sound, near Britannia Cove, the Smith Point 

limestone, carrying Hyolithes, etc., is well exposed, and 220 feet above it, in the green shales, 

Olenellus (H.) broggeri was found. Below, the limestone beds are much broken. Crossing 

Random Island from Britannia Cove to the north shore of Random Sound, one finds a much 

more complete section, east of Hickmans Harbor Point. At Hiekmans Harbor Point the 

Signal Hill conglomerate of the Avalon series is well exposed, and above, to the eastward, the 

Random terrane. The summit of the latter is very beautifully shown at the slate quarries 

about half a mile east of Hickmans Point, where the strike of the upper bed of the Random 

sandstone is N. 50° E., dip 70° SE. Immediately on this band of reddish-tinted sandstone 

there is a thin layer of conglomeratic limestone that forms the basal bed of the Cambrian. 

Random Sound section, upward: J<'t. in. 

la. Conglomerate formed of smalltpebbles of the subjacent Random rocks, and small quartz 

grains and pebbles, all cemented together by a fine calcareous sandy matrix. Often 

there is scarcely a trace of calcareous matter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 

Fossils: Slender tubes of Coleoloides and fragments suggest Arckeocyathus. 

lb. Reddish-purple sandstones capped by coarae-grained grayish-purple sandstone 6 inches 

thick.......................................................................... 3 

lc. Pinkish-colored limestone with Coleoloides......................................... 6 

ld. Reddish-purple argillaceous shale................................................... 10 

le. Purple to pink, hard, irregular arenaceous limestone.................................. 1! 

Fossils: Coleoloides and sections of what appears to be a small Obolella-like shell. 

lf. Green and reddish-purple argillaceous shale in broad bands. At 140 feet up nodular 

limestone appears, and at 170 feet a band of pinkish-colored lime~tone 6 inches thick 

with Coleoloides....... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 

A change of dip and overturn occurs here, which breaks the section and cuts out probably 100 feet or more of the shales. Estimated .................................... 100 

lg. Green argillaceous shale............................................................ 42 

lh. Reddish-purple argillaceous shale................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 

li. Greeni•h argillaceous shale................................... . . . . . . . . . . . . . . . . . . . 84 

lj. Pinkish-colored, massive-bedded nodular limestone.................................. 6 

Fossils: Hyolithes princeps, Coleoloides typicalis, also numerous fragments of small 

Hyolithes, of which, owing to the cleavage of the limestone, it was impossible to get 

good specimens. 

lk. Reddish-purple and green argillaceous slates, cleaned so as to make a good roofing slate 

at Bryant's quarries, about 1 mile east of Hickmans Point. The estimated thickness 

of this slate in the syncline is over 200 feet.. ...................................... 200+ 

The total thickness of the section up to the Hyolithes limestone is over 500 feet, which, 

with the 369 feet above the limestone at Smith Point, gives a total thickness of fully 

900 feet for the Lower Cambrian on the western side of Trinity Bay. 

In the city of St. John [New Brunswick] the examination of the outcrops led me to the 

conclusion (a) that the Lower Cambrian strata beneath the St. John quartzite had been 

deposited on and against an irregular, uneven shore line; (b) that the sands of the St. John 

quartzite had been spread conformably over the beds of the Lower Cambrian ("Etcheminian"); 

(c) that where the pre-Cambrian (Algonkian) roc~s projected above the Cambrian beds, 

or formed the shore lines, the St. John quartzite conformably overlapped the reddishpurple and greenish-colored arenaceo-micaceous shales and thin-bedded sandstones of the 

Lower Cambrian ("Etcheminian") and came in unconformable contact with the Algonkian 

rocks. * * * 
GA.MBRIAN AND LOWER ORDOVICIAN. 143 

Seely Street section.-'fhe section exposed at the head of Seely Street, beside the Park 

Road, is as follows. The pre-Cambrian Algonkian rocks have an uneven surface where the 

basal beds of the Cambrian rest against them. 

Lower Cambrian, upward: Feet. 

la. Dark reddish-brown fine conglomerate and sandstone, with reddish and green, hard 

arenaceous shale. The conglomerate contains small quartz pebbles and bits of the 

' subjacent Algonkian siliceous beds. Strike N. 40° [E.] mag., dip 70° SE.......... 12 

I b. Space concealed. From the abundant debris in the soil as exposed in a cutting 

be.<ide the road the section here is formed of reddish-purple and green sandy 

shales .................. _ .. _ ... _. _ .. _____ . _ .... __ .. ____ ..... _. __ . ___ . ___ ... ___ .. 85 

lc. Reddish-purple and greeni'h arenaceo-micaceom shales and thin-bedded sandstone.. 52 

Middle Cambrian: 

2a. Light-gray fine-grained quartzitic sandstone in thick layem. The grains of sand 

become coar.Jer in the upper part of section and a layer of white quartz-pebble conglomerate occurs near the summit. Strike at base N. 55° E. mag., dip 70° SE ..... 40-45 

· 2b. Arenaceous and argillaceous greenish-colored shales and thin-bedded sandstones, 

passing above into dark argillaceous shales. About 25 feet above the base the Paradoxides fauna appears in great abundance. For further details of the section of the 

St. John Cambrian rocks see Mr. Matthew's papers. 

It will be noted that the strike of the basal Lower Cambrian bed la is N. 40°, while that 

of the St. John quartzite is N. 55° E. This does not indicate an unconformity as the change 

of strike occurs in the beds below; the shalE's just bt>neath the quartzite are conformable to 

the quartzite. 

Hariford Brook section, St. John County, New Br-unswick.-The Middle Cambrian portion 

of the Hanford Brook section as exposed at MeAft>e's sawmill on the south bank of the brook 

below the mill is as follows: 

Middle Cambrian downward: Feet. 

la. Greenish-colored argillaceous shales with abundant remains of Paradoxides and other 

forms of the Paradoxides fauna ...... _ .. ________ ..... _ .... _ .. ____ . ___ ... _ ....... __ .. 30+ 

lb. Massive calcareo-argillaceom layer carrying the Paradoxides lamellatus fauna. Strike E. 

and W., dip 45° N .............. __ ...... _. _ .... ____ ... _ .. _ .. __ . _ ... _. _............. 3 

2a. Gray sandstone and greenish arenaceous and argillaceous shale. _ .. _ . _ . _ . _ . _ . _ . ___ . . . . . . 34 

Very few traces of fossils were found in this bed. It is the horizon of fauna b4 and b5 of 

Matthew. 

2b. Greenish argillaceous shale with a layer of sandstone 8 inches thick, and a little below, 

another layer of sandstone .. 4 feet in thickness. The sandstones are very hard, fine 

t,rrained, and with fossiliferous phosphatic nodules near the bottom .... _._._._._._ ... _ 10 

Fossils: This horizon carries the Protolenus fauna, fauna b3 of Matthew. 

2c. Fine-grained dark-gray arenaceous argillites in layers 10 to 20 inches in thickness, that 

break up on exposure into irregular shaly layers. Strike E. and W., dip 25° N. _. _ .... 16 

Fossils: Protolenus fauna, b2 of Matthew. About midway of the subdivision there is a 

layer of greenish-gray fine-grained sandstone 14 inches in thickness, in which numerous 

small phosphatic nodules occur in the lower 3 inches, with many fragments of fossils. 

2d. Dark-green to grayish-green fine-grained compact, hard sandstone._._._._._ ............ 18 

Fosfils: Fauna bl of Matthew. 

3. Light-gray to white quartzitic sandstone in massive layers, the upper portion passing into 

greenish-tinted quartzitic sandstone. __ ._ .. _._. __ . ____ .... _ .. _ ... _ ... _ .. ___ .......... 30+ 

The section from the quartzite downward for a distance of nearly 300 feet on the surface 

is entirely concealed. The highest beds of the subjacent Lower Cambrian are exposed at 

the upper end of the mill pond, where they have a strike of N. 60° E., dip 20° NW. 

Lower Cambrian downward: Feet. 

la. Estimated thickness coRcealed beneath the "St. John quartzite".................... 136 

lb. Massive-bedded dark purplish-colored arenaceous shales and sandstones. Toward 

the lower portion a few calcareous nodules appear in the shales................... 320 

Strike in upper beds, N. 60° E., dip 20° NW. In beds 215 feet below summit, strike 

N. 70° E., dip averaging 20°-25° NW. 
144 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Lower Cambrian downward-Continued. Feet. 

1c. Reddish and greenish arenaceous and argillaceous shales and thin-~edded sandstones, 

with a few thin interbedded calcareous sandst'lnes. Strike N. 65° E., dip 3-5° to 

40° N\V........................................................................ 30 

Fossils: In a thin reddish-brown, slightly calcareous sandstone occur great numbers of 

a slender species of Hyolithes that resemble H. communis. Just below it I noted, in 

a hard, very fine grained, compact sandstone, specimens of Coleoloides like G. 

typicalis and a large Iphidea labradorica? This appears to be the horizon of the 

Hyolithes limestone fauna of the Smith Sound section of Newfoundland. Unfortunately the sediments are of a type in which fossils are rarely found well preserved. 

2. Reddish-purple conglomerate in fine sandstone matrix. White quartz and reddish and 

greenish siliceous pebbles occur, some of which are from 2 to 6 inches in diameter. 

Strike N. 65° E., dip 40° NW...................................................... 31 

3. Reddish-purple to grayish-purple fine-grained sandstones, passing into flaggy gray and 

greenish-gray micaceous sandstone, interbedded with thick layers of sandstone...... 395 

About 120 feet down a few layers of white quartz pebbles appear in the dark sandstone, 

and at 175 feet down broad annelid trails were seen on the smooth surface of a thick 

layer of sandstone. 

The dip decreases from 40° :ctt the top to 30°, and then 25° at the base, where the strike 

is N. 55° E. 

At this point the upper beds of the basal conglomerate outcrop on the south side of the 

brook, but they are cut off a few feet down by a fault that brings up some of the beds 

of No. 3 of the section, and possibly No. 1c. On the north side of the brook a syncline 

and fault expose a considerable portion of No. 3 of the section. Up the brook the 

basal quartzite appears again beneath the sandstone of No.3, from which it extend8 

nearly to the contact with dark pyroclastic andesitic rocks of the Algonkian. 

4. Rather coarse siliceous, massive-bedded conglomerate, formed of white quartz, jaspery 

reddish and greenish-colored pebbles. The upper 8 feet has a light-gray color that 

passes below to a purplish tint. ............................................. _. . . . . . . 128 

Total of Lower Cambrian........................................ . . . . . . . . . . . . . 1,040 

The contact with the Algonkian rocks is not seen, the base of the· conglomerate being considered as near the last angular bowlders of the conglomerate seen in the bank, a little distance 

below the outcrop of Algonkian rocks. 
CAMBRIAN AND LOWER ORDOVICIAN. 145 

In connection with the discussion of the Etcheminian, ·walcott 857 published 

the following general classification of Cambl'ian formations: 

d 

-~ ... 

.D 

s 

u '" 

I 

d 

.;::1 

... 

.D 

s 

u '" 

0 

;:a 

:s 

~ 

.:::: 

.;::1 

Lower Calciferous. 

Classification ojthe Oambrianformations. 

I 

,

1

' Lower portion of the Calciferous sandrock of New York and Canada; Lower Magnesian limestone of Wisconsin, Missouri, etc. 

~--------------' 

''Potsdam" 

togan]. 

Acadian . 

I Type. 

I 

Sandstones of the north and east sides of the Adirondack Mountains of New York 

and adjoining parts of Canada. 

: Correlated. 

I Limestones of the south side of the Adirondacks and Dutchess County, New York, 

and an unknown portion of the limestones of the "marble belt" of western 

[Sara- Vermont. 

Shales of Tennessee (Knox), Georgia, and Alabama (Conasauga). 

Sandstones of the upper Mississippi Valley (St. Croix), South Dakota, Wyoming, 

Montana, and Colorado. 

Sandstones and calcareous beds of northern Arizona (Tonto) and central Texas 

(Katemcy). 

Limestones and shales of Nevada (Hamburg), Idaho, and Montana (Gallatin). 

Black shales of the upper portion of the New Brunswick and Cape Breton Island 

sections. 

Shales and sandstones of Conception Bay, Newfoundland (Belleisle). 

Type. 

Shales and slates of eastern Massachusetts (Braintree), New Brunswick (St. John), 

and eastern Newfoundland (Avalon) . 

Correlated. 

Limestones of Dutchess County, ~. Y. (Stissing), and central portions of Tennes- see and Alabama sections (Coosa). 

Limestones of central Nevada and British Columbia (Mount Stephen). 

Type. 

Shales and limestones of western Vermont (Georgia) and Red sandrock. 

Correlated . 

~ Georgian. 

Quartzite of western slope of Green MountainR ("Granular quartz") and Appalachian Range of Pennsylvania, Virginia, Tennessee (Chilhowee), Georgia, and 

Alabama. 

Shales with interbedded limestones and roofing slates of southern Vermont, New 

York, and south to Alabama. u '" 

@ 

~ ,...1 

Limestone, sandstone, and shales of Straits of Belleisle (Labrador), northwest 

coast of Newfoundland, and peninsula of Avalon (Placentia). 

Basal series of Hanford Brook section, Caton's Island, etc., New Brunswick 

(Hanford). 

Shales and limestones of eastern and southeastern Massachusetts (Attleboro). 

Lower portion of Eureka and Highland ranges, Nevada (Prospect). 

Portion of Wasatch Cambrian section (Cottonwood). 

Base of Castle Mountain limestone, British Columbia (Castle Mountain). 

In 1904 Matthew 581 published the results of his studies of the Cambrian of 

Cape Breton. He gives detailed sections and diagrams and presents a revised 

classification with the following comments: 

In consequence of the finding of trilobites, brachiopods, etc., of Cambrian genera in the 

Etcheminian strata, and for reasons given below, the writer proposes to revert to the classification of 1889, wherein these deposits are called the Basal series (of the Cambrian system). 

It has been found that slates with fossils of Cambrian genera are included in the important 

group of volcanic rocks which lie at the base of the Etcheminian, and that where the dip of the 

48011°-12--10 
146 INDEX TO THE STRATIGRAPHY OF NORTH AMERIUA. 

volcanics can be found, as is not infrequently the case, it agrees with that of the Etcheminian. 

It is thought therefore that those volcanics (the Coldbrook group) should be included in the 

Basal Cambrian. 

Both inN ew Brunswick and in Cape Breton the Cold brook group begins with lavas showing 

deposition free of pressure, as they are amygdaloidal; or with agglomerates devoid of evidence 

of marked aqueous wear. The deposition therefore did not begin in deep water, or on exposed 

sea coasts, or under heavy pressure. The foundation upon which the volcanics rest shows in 

several places marks of deep subaerial decay at the line of contact. Calcareous bands are dissolved, leaving the siliceous portion of the strata. · The feldspar of the granitic rocks is kaolinized 

and the magnesian silicates are hydrated, impure graphite beds are changed to a black amorphous crumbling shale, and a depression or narrow valley is usually found at the contact of the 

two terranes. These conditions appear to indicate that the pre-Cambrian complex had long 

been above the sea level in these districts when the first Cambrian effusives were thrown out 

upon it. 

Another point worthy of note in this connection is the large amount of feldspathic material 

in the Etcheminian beds; the very sands are oftencomposed of feldspathic grains, and these 

largely of nonkaolinized feldspar, as though they had not been exposed to subaerial decay. 

Feldspar in this condition is found in two kinds of deposits, those that are the result of glacial 

wear and those found around volcanic vents, where particles of rock have been torn from the 

walls and blown out upon the surface of the ~arth. These if dropped into the sea would soon 

be covered up by fine mud and preserved in their original crystalline condition. The Etcheminian appears to represent largely the submarine condition of such effusive rocks. On the other 

hand, the Coldbrook series, as has been intimated above, represents the preceding subaerial 

phase of the eruptives. It is true that we find in many places conglomerates at the contact of 

these two series of rocks, thus diverse in appearance; but elsewhere there are no beds of rolled 

fragments at the contact, and the passage is direct from ash beds or diabases to the slates and 

sandstones. In reports of the Canadian Geological Survey of 1870-71, pages 57-59, etc., 

relating to the province of New Brunswick, both these groups of rocks have been included in 

the Huronian system. They may be equivalent in age to the upper part of that series, but 

unfortunately the absence of fossils in the original Huronian leaves this matter in doubt. 

As we contemplate the physital conditions of the initial epochs of Cambrian time in the 

Maritime Provinces, we seem to see a region long elevated above the sea, now subjected to 

depression nearly to the sea level, the depression being accompanied with extrusion of lavas 

and volcanic mud and the ejection of stones and ashes. These at first were cast upon a land 

surface, but, as the crust of the earth continued to sink, it was covered by the sounds and bays 

of a shallow sea, diversified with pre-Cambrian ridges and islands, of greater or less extent. 

For the above reasons, as well as because the stratified rocks of the underlying complex 

are markedly unconformable to the Cambrian, the volcanics are thought to belong to the latter, 

and to give the natural base of this system. 

The accompanying table will then show the classification of the Cambrian system, as seen 

in the Maritime Provinces of Canada. 
CAMBRIAN AND LOWER ORDOVICIAK. 147 

Base of the Paleozoic rocks in the Maritime Provinces of Canada. 

Groups and kind of rocks in Cape Breton. 

:~. Dark-gray and black carbonaceous shales, 

often changed to slates; a few thin seams and lentils of dark limestone, 

and some thin flags. 

2. Micaceous gray slates, flagstones, and 

quartzites. Iron bearing in Mira Valley, Cape Breton. 

1. Dark-gray slates or shales with calcareous 

lentils. Gray sandstones. Interraned 

conglomerates at and near base. 

3. Fine greenish-gray argillites, some reddish gray. Horizon of roofing slates in 

Cape Breton and Newfoundland. 

2. Red sandstone and red and gray argillite. 

Lower iron-bearing horizon of Cape 

Breton Cambrian. 

1. Gray shale or slate with some quartzite 

and conglomerate, the latter especially 

at the base .. 

I 

Zl 

s 

0.. 

Q) 

.... 

0! 

.;::; 

6D 

0 

Q) 

bD 

>:: 

.~ 

'"0 

"' >:: 

"' ·:;..! 

0 

0.. 

;:l 

0 

1;0 

>:: 

..<:I 

0 

..... 

~ 

."' 

'-' 

·~ 

§ 

,., 

li 

~ ~ 

0 

Co. Dole:.ites, breccias, and amygdaloidal -1·1 

ashrocks. Somegrayshalesaboutmiddle. j ~ 

.:i 

.~ .... 

;:l d ~ .~ w (.) 

.... ·:;: Q) 0 

!3:: '"0 0 ,., H 0 

----

.§ ci .... 

..0 

s .~ ,., 

"' ..0 8 s 

0! "' Q 

:fl ,., 

0 

.§ 

.... 

il-< 

2 

·s ! j ~ ~ I 

Leading genera of the several groups . 

e. Harpes, Trinucleus, in northwestern ~ ew Brunswick. 

d. Cyclognathus, Parabolinella, Tetragraptus, 

Didymograptus, in southern New Brunswick. 

c2 • Asaphellus, Parabolinella, 

Bellerophon. 

Triarthrus, 

-------~- ·---------

c. Dictyonema, Monobolina, Schizambon, 

Acrotreta. ,£;-

b. Peltura, Spha=rophthalmus, Leptoplastus, 1:, 

Ctenopyge. I 0 a. Parabolma, Agnostus, Anomocare, Orthis, , >=:< 

in southern New Brunswick. 

- ---------!--.-- ~~ >=~ ·ai~ 

·..c::~"'S I c. Agnostus, Lingulella. (Place of Olen us.) ·.::: ~ g ~ ~"'0$ 

ri.§ 0 ,--------------------------

..... 1 

~ 

ci 

.~ 

>:: ·s 

..<:I "' (.) 

...., 

~ 

-

b. Paradoxides, Beyrichia, Lingulepis . a. Obolus, Lingulella, Lingulepis. 

d, e. Paradoxides, Solenopleura; Ptychoparia, 

l\ficrod isc us. 

c. Paradoxides, Conocoryphe, Liostracus, 

Agnostus. 

a-b. Protolenus, Ellipsocephalus, Beyrichona, 

Trematobolus, in southern New Brunswick. 

Solenopleura?, Ostracoda, 4 genera. 

Acroth~le, Lingulella, Obolus, Acrothyra, I 

Hyolithes. 

_M---1-------------------' 

,.; 

"' !3:: 

0 

H 

,...; 

'"0 

>:: 

'"' "'' 

Holasaphus, paradoxidoid trilobite, Ostracoda, Billingsella, Lingulella, Aerothyra, Obolus, Hyolithes. 

Lingulepis, Leptobolus, Obolus, Lingulella, Acrothyra, Acrotreta, Hyolithes. 

J5< a ,-~ .~ Obolus, Lingulella. Linguledsis. - ~ Acrothyra, Acrotreta, Leptobolus. 

o o 2 Ostracoda. r:..:>~ 
148 INDEX TO THE S'fRATIGRAPHY OF NORTH AlVfERICA. 

L-Q 10-21. CANADIAN SHIELD. 

Throughout the region covered by the Canadian Survey there occur areas of 

unfossiliferous clastic, usually sandy formations (the Athabaska-Nastopoka series), 

which rest unconformably on the metamorphosed or disturbed pre-Cambrian rocks 

and are themselves but little disturbed. They have been described as "Cambrian" 

by the Canadian Survey, but are now believed to be older than the Olenellus fauna, 

and consequently to belong to the late pre-Cambrian, according to the classification 

in this paper. 

M 19-20. GASPE PENINSULA. 

The Cambrian ("Quebec group") is poorly exposed on the Gaspe Peninsula 

but is described by Logan 544k as follows: 

Below the Magdalen, the breadth of the formation has been ascertained by transverse sections in two places only; one of them being at the Great Pond River, where it is about 2 miles, 

and the other at Griffin Cove, where it is less. Approaching Cape Rosier the breadth gradually 

diminishes; and the Hudson River strata finally disappear under the waters of the Gulf, at 

Anse a Ia Tierce. The remainder of the distance to Cape Rosier is occupied by the gray 

calcareous sandstones, red shales, and limestone conglomerates of the Quebec group. 

In the Great Pond section also the rocks which succeed to the Hudson River strata belong 

to the Quebec group, and they prevail for a breadth of about 11 miles, before becoming covered 

up by the Upper Silurian limestones. Two miles in the middle of this section are occupied by 

sandstones of the Sillery series, with the red shales which usually accompany them. The dips 

on both sides of the area occupied by these sandstones are to the southward; the inclination 

on the north side being 51° and that on the south side 64°. It is probable, however, that the 

strata are arranged in a synclinal form, and that those on the south side are inverted; the general synclinal probably contains several subordinate undulations of a similar character. The 

rocks on each side of the sandstone appear to belong to the Levis formation; some of the masses 

on the south side resemble the magnesian conglomerate bands of Point Levis. * * * 

On the section from Griffin Cove, at the distance of 2 miles southwestward from the coast, 

about one-eighth of a mile is covered with large angular fragments of greenish sandstone, some 

of which are fine conglomerates, with quartz pebbles as large as peas. None of this rock has 

been seen in place; but the abundance and angularity of the fragments leave little doubt that 

the beds can not be far removed. The position of the fragments may therefore be assumed as 

that of the Sillery sandstones, particularly as they occur in what would be a continuation of the 

axis of the Sillery synclinal on the Great Pond section. Between the position of these sandstones and the Hudson River strata on the coast there would be room for the rocks of the Levis 

formation, but none of them have been there observed. * * * 

Between Cape Rosier and the base of the Gaspe limestones a sudden turn in the coast gives 

a natural section, nearly at right angles to the strike, of 2t miles in length. The coast is low 

and shelving, and the violence of southeastern storms has heaped upon it a great mass of gray 

limestone shingle, which covers nearly the whole of it, with the exception of three points. One 

of these is Cape Rosier itself, where a breadth of 450 yards of the strata, including what are 

seen between high and low water marks, is exposed. The strata consist of gray limestones, in 

beds varying from 6 inches to a foot in thickness, with two thicker conglomerate beds, made up 

of gray limestone pebbles in a calcareous matrix, very much resembling the conglomerates of 

Ste. Anne des Monts, the whole interstratified with black and gray shales. Separated from the 

strata of the cape by an interval of 1,000 yards, covered by limestone shingle, there occur, at 

the next point exposed, gray, yellow-weathering limestones, probably magnesian, interstratified with jet-black and gray shales, with a band of conglomerate or brecciated limestone on 

the northeast side. The distance across the strata is about 800 yards; but there are intervals 

of concealment in it, making up 300 yards of the amount, and, though the dip is pretty uniform 

in direction to the southwest, there are variations in the inclination, which ranges from 44 ° to 

60°. Another interval of concealment occurs, of about 1,000 yards .across the measures; but a 
CA..\1BRIAN AND LOWER ORDOVICIAN. 149 

partial exposure at the end of the distance shows a continuation of the same alternation of 

shales, limestones, and sandstones. Red, purple, black, and olive-green shales succeed, associated with gray sandstones; some beds fine grained and close in texture and others coarse, 

with transparent quartz, silvery mica, white feldspar, and very minute bright green grains, 

probably of glauconite. A few thin layers of black bituminous limestone are interstratified 

among the shales. Several corrugations are visible in a low cliff, in which these beds are exposed; 

but the measurement across the shales is about 350 yards, and the dip, which is southwestward, 

varies in inclination from 26° to goo. 

Between these beds and the base of the Gaspe limestones there is a distance of about 800 

yards across the shales, but the strata are only obscurely seen at intervals at the beginning and 

end of the measurement. The strike appears to be uniform, being N. 62° W.; but only the 

extreme edges of the beds are anywhere seen, and the dip is sometimes to the one side and sometimes to the other, at inclinations varying from 50° to goo. The strata consist of black shales 

and thin limestones, which become somewhat arenaceous toward the south side; and the last 

beds, seen immediately in contact with the overlying Gaspe limestones, are of jet-black shale, 

yielding a black powder. 

M 21. NORTHERN NEWFOUNDLAND. 

Logan 544Y described the lower Paleozoic strata of northern Newfoundland 

under the headings "Potsdam group" and "Quebec group." He first recognized 

sixteen divisions and later reclassified them under letters.· He says: 

In the ascending section of the Labrador and Newfoundland rocks the divisions were 

arranged under the numerals 1 to 16. Some of these divisions have since been remeasured in 

greater detail than before; while with respect to others, the examination of their equivalents 

in other localities has shown that these divisions include additional strata. In giving these 

farther results, it will be convenient to designate the divisions by letters, and to indicate the 

subordinate parts of each by numerals. To facilitate a comparison of the present results with 

those stated in the previous chapter, a summary of the section already referred to is here given, 

with the former numerals, but having the letters now to be used, prefixed. The thickness 

formerly assigned to these divisions, and the localities in which they were observed, are also 

appended. 

Potsdarn group [Cambrian]. 

Feet. 

A. l. Red and gray sandstones ........................... Anse au Loup ............ ~...... 2_31 

B. 2. Gray, reddish, and green limestones ..................... do.......................... 143 

C. 3. ·white sandstones, concealed ........................ Strait of Belleisle................ 250 

624 

Quebec group. 

D. 4. Gray and reddish magnesian limestones ............. St. Barbe Bay.................... 150 

E. 5. Dark-gray limestones .................................. do.......................... 400 

F. 6. Dark-gray geodlferous limestones ................... Port au Choix................... 400 

G. 7. Dark-gray limestones .................................. do.......................... 130 

H. 8. Grayish-blue limestones ................................ do.......................... 340 

I. 9. Light yellowish-gray magnesian limestones ............... do . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 

K. 10. Gray and whitish magnesian limestones ............. Point Rich................ . . . . . . . 130 

L. 11. Light bluish-gray limestones ............................ do.......................... 130 

M. 12. Light bluish-gray limestones ........................ Table Head..................... 550 

N. 13. Black bituminotlS limestones .......................... do.......................... 200 

2,580 

0. 14. Gray calcareous sandstones and black shales ....... Cow Head........................ 700 

P. 15. Gray and white limestone conglomerates ............... do.......................... 700 

1, 400 

Q. 16. Greenish sandstones and red shales .................. Bonne Bay..... . . . . . . . . . . . . ... . . . 2, 000 

6,604 
150 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The preceding summary represents Logan's conclusions in assembling the 

results of his observations. The measured sections are given by him in detail and 

may be abstracted as follows: 

Between 1 and 2 miles inland from the northeast side of the East Arm of Bonne Bay 

[northern Newfoundland] there arises a range of hills of Laurentian gneiss, 2,000 or 3,000 feet 

m height, on the flank of which is exposed the following measured section: 

A. 

Feet. 

1. Blackish-blue fine-grained slate. Of this slate only 105 feet of the upper part are seen; the 

lower part is concealed in the space between the upper portion and the gneiss and may 

comprise a thickness of about 230 feet................................................ 335 

2. Blackish-blue slate interstratified with gray quartzites, in beds of from 6 inches to 3 and 4 

feet. In the 80 feet at the bottom the quartzites greatly predominate, and they constitute 

15 feet at the top, while the intermediate 175 feet consist chiefly of slate. . . . . . . . . . . . . . . 270 

B. 

1. Light-gray, yellow-weathering limestone, in beds of from 1 to 3 inches thick, interstratified 

with blackish-blue, slightly calcareous slate, both containing small specks of silver-white 

mica, which are more abundant in the limestone than in the slate. The limestones hold in 

abundance fragments of trilobites, chiefly belonging to three or four species. Among them 

is Paradoxides (Olenellus) 1>ermontana, a new species of Bathyurus, and the pygidium of a 

species so closely resembling B. extans of the Birdseye and Black River formation that it 

605 

can scarcely be distinguished from it and may possibly be the same.................... 80 

2. Grayish-green micaceo-arenaceous shale, interstratified with a few beds of grayish quartzite 

weathering slightly yellow.......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 

3. Strata concealed ... :. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 

4. Reddish granular quartzite in thick beds............................................... 105 

5. Gray and grayish-green micaceo-arenaceous shale in beds from a quarter of an inch to an 

inch thick, interstratified with a few beds of gray, very ferruginous sandy dolomite and 

fewer of gray quartzite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 

6. Reddish quartzite, in beds offrom 1 to 2 feet thick................................... . . . 34 

7. Gray arenaceous dolomite, weathering yellowish brown, interstratified with reddish quartzite, in beds of from 1 inch to 1 foot thick, and with reddish and grayish micaceoarenaceous shale, predominating toward the top. The beds of dolomite and shale contain 

fossils, among which are Obolella chromatica?, Obolus labradoricus, Paradoxides vermontana, 

Conocephalites, a new species of Bathyurus, and one or more undetermined species of 

Salterella . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 

c. 

1. Whitish quartzite in beds of from 6 inches to 2 feet, interstratified with light-gray micaceoarenaceous shale, in layers of from 6 inches to 1 foot, which occur at intervals of from 5 

483 

to 10 feet........ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 

2. White and reddish quartzite, in beds of from 1 to 3 feet thick, interstratified toward the 

bottom with a gray arenaceous dolomite, weathering yellowish brown................... 160 

3. White and reddish quartzite, in beds of from 1 to 3 feet thick, interstratified with greenish 

micaceo-arenaceous shale, constituting about one-half the amount...................... 90 

4. Gray pure limestone, in beds of from 1 to 3 feet thick, marked with a few reticulating strings 

of yellowish-weathering dolomite. The rock is a mass of comminuted organic remainF, 

among which are Paradoxides vermontana and undetermined species of Bathyurus and 

Salterella, as before . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 

5. Blackish-blue soft shale, interstratified with gray, yellow-weathering limestone. probably 

magnesian, in beds of 1 or 2 inches thick. The quantities of shale and limestone are 

about equal, and the whole is intersected by reticulating strings .of calc spar. . . . . . . . . . . . 35 
CAMBRIAN AND LOWER ORDOVICIAN. 

Feet. 

6. Gray pure limestone, composed of comminuted organic remain~, belonging to Paradoxide~, 

BathyuruB, and Salterella, as before .. _____________ . ____ ...... ____ ...... _............ . 27 

7. Bluish-black soft shale, interstratified with gray, yellow-weathering dolomitic bands, aR 

before. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 

8. Gray pure limestone, probably composed of comminuted organic remains as before; underlaid by bluish-black shale inclosing nodules of blue compact limestone; some of which 

weather yellowish-brown, and are probably magneRian . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 

9. Bluish-black soft shale of the same character as before, interstratified with a few beds of 

quartzite ..... _ ....... _............................................................. 68 

62B 

1,711 

151 

The summit of the above section occurs on the east side of Deer Brook Bay, on the East 

Arm of Bonne Bay, and its base about 6 or 7 miles up the East Arm from the mouth of Deer 

Brook. All of the beds can be seen coming to the coast in succession, with a westward dip, 

and an inclination of from 20° to 60°. Where the beds of the base were observed, the measures 

appear to fold over an anticlinal axis, and for about 100 yards they dip to the eastward. For 

2 miles beyond this, along the east side of East Bay, the greatest confusion prevails, and nothing 

·reliable in regard to the sequence can be obtained from the exposures. East Bay and West 

Bay are two deep southward parallel indentations of the coast, which form the extremity of 

the East Arm. The area between them is from 1 to 2 miles wide, and the strata in it appear 

to lie in the form of a synclinal. The axis of this synclinal would run about north and south, 

and in the former direction it would strike to the eastward of the anticlinal just mentioned as 

occurring on the north side of the East Arm, while the axis of this anticlinal would strike into 

West Bay. The distance across the East Arm, on the axis of the synclinal, from the position 

where the lowest beds of the section above given would come upon it to the position where it 

would be crossed by the lowest beds bt~tween East and West bays would be about the same 

as that occupied by the whole section between the Laurentian gneiss and the coast of Deer 

Brook Bay. On the west side of this bay there occur some limestones of a peculiar color and 

character, whose stratigraphical place would be a few hundred feet above the highest beds in 

the section just given. About the same distance above the base of the strata between East 

and West bays similar limestones occur; and there is therefore not much doubt that the 

strata between these bays come in immediate or proximate sequence to those already given 

in section C. These additional strata are as followR: 

C-Co'utinued. 

Feet. 

10. White quartzite, in beds of from 2 to 3 feet thick, interstratified with striped olive-drab and 

black compact arenaceous magnesian brown-weathering limestone, which constitutes onefourth of the mass and holds small diBseminated masses of iron pyrites ............ ,_ .. ___ 58 

ll. Strata concealed....................................................... . . . . . . . . . . . . . . . . . 150 

12. Blackish-gray limestone; it is divided into beds of from 2 to 8 inches, and under the influence 

of the weather breaks up into thin scales........................... . . . . . . . . . . . . . . . . . . . . 54 

13. Smoke-gray compact pure limestone, striped with ocher-yellow arenaceo-ferruginous limestone, passing into brick-red. The gray and yellow alternate in lenticular layers, varying 

in thickness from a quarter to half an inch, and the rock presents a very peculiar and 

striking aspect. The yellow and red colors may be the effect of weathering, but in breaking up the rock the same alternation of these with the gray limestone was apparent in the 

interior. Rock of the same character occurs on the west side of Deer Brook Bay .. ______ . 30 

14. Olive-gray, brown-weathering ferruginous sandy dolomite, containing thin lenticular patches 

and thin beds of pure smoke-gray limestone, with disseminated cubes and small masses of 

iron pyrites............... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 

309 
• 

152 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

D. 

1. Greenish-white and yellowish-white magnesian limmtone, in massive beds, some of which 

are ferruginous and weather buff, while others remain unchanged in color. They are 

interstratified with beds of ash-gray limestone, weathering yellowish, and near the middle 

with two bands of gray calcareo-arenaceous shale, one of 2 and the other of 3 feet thick. 

These massive limestones terminate in a 4-foot bed of smoke-gray pure limestone in thin 

layers, interstratified with thin layers of probably magnesian limestone, weathering ocheryellow. The bed, for the thickness of a foot, is arranged on the strike in a series of curves 

or arches, which span from 2 to 3 feet, separated by straight intervals, varying from l to 2 

feet. The curved portions appear to hold a greater number of the yellow-weathering layers 

than the straight parts, and these layers have in general a lenticular form. The top and 

bottom of the bed are arranged in even layers, which fill up the inequalities of the interFeet. 

mediate part ......................................................................... 174 

483 

The surface between East and West bays rises into a mountain of 500 or 600 feet in height, 

in which the strata dip in directions conforming to their synclinal arrangement, at angles varying 

from 12° to 25°. Proceeding southward along t~e east side of West Bay, they are seen to 

accumulate above one another to the amount of 1,400 feet, in addition to the preceding section. 

These higher strata consist almost entirely of limestone of various shades of gray, with two or 

three bands of black, the latter usually thin bedded. Of the lowest 200 feet, about two-fifths 

weather to various shades of yellow and brown; of the succeeding 300 feet the proportion of 

yellow-weathering beds is about one-sixth, and in the remaining 900 feet they are but few. If 

these yellow-weathering beds are, like the similar ones in the detailed section just given, magnesian, it would appear that the proportion of magnesia gradually diminishes in ascending 

this portion of the series. In the whole of these 1,400 feet, which are supposed to represent 

the divisions E, F, G, the only strata in which fossils were observed occur at about 400 feet 

from the top; where the surfaces of various beds, in a thickness of between 10 and 20 feet, are 

marked by the weathered-out forms of silicified fossils, consisting of undetermined species of 

Pleurotomaria and Ophileta. 

From West Bay the strata strike, in a general way, along the coast to the westward; they 

are much contorted and it is difficult to make out any true continuous succession of the beds. 

At the west horn of the bay, however, the whitish massive magnesian limestones of division D 

occur; and in the contorted strata for a couple of miles beyond the peculiarly striped smokegray and ocher-yellow thin-bedded limestones of C 13 are occasionally seen. At the promontory 

which faces the west horn of Deer Brook Bay the strata become vertical, or nearly so, but 

somewhat more regular; and the absence of any beds weathering yellow or brown appears to 

indicate a proximity to the horizon of the silicified fossils above mentioned. About 800 feet 

of dark-gray limestones are here exposed, at the summit of which there occurs a bed holding 

Maclurea, Orthoceras piscator, and Leperditia. Of the genus Maclurea the opercula were the 

only parts observed and these are silicified; but the bed is supposed to be higher in the series 

than the band with silicified fossils between East and West bays, inasmuch as it is immediately 

followed, not by the dark-gray limestones, but by about 200 feet of light-gray limestone; a good 

deal of which, although it does not weather yellow, is magnesian. The summit of these 200 

feet is fossiliferous and contains undetermined or undescribed species of Orthis, Ophileta, 

Machirea, Nautilus, Amphion, Asaphus, and Leperditia. The 800 feet are probably comprised 

· in the divisions F and G, while the 200 feet may constitute a part of H. 

The divisions M and N of the Newfoundland rocks have been, in a general way, described 

from exposures occurring at Table Head. The total thickness was here estimated from measurements by pacing, but few details were ascertained; and the fossils collected having been 

lost, from the necessity of abandoning them on the coast through stress of weather, it was 

considered expedient to reexamine the locality. The following detailed ascending section is 

the result. It commences between 600 and 700 feet lower than the strata comprised in the 
CAMBRIAN AND LOWER ORDOVICIAN. 153 

division M, or 12, as previously given, and the lowest part of these additional strata are 

considered equivalent to some of those at Point Rich. 

H. 

1. Bluish-gray limestone in beds of from 1 to 2 inches, interstratified with gray subcryRtalline 

yellow-weathering magnesian limestone in beds of from 3 to 6 inches thick. The beds 

are fossiliferous, containing the genera Orthis, Ophileta, Maclurea, Pleurotomaria, Murchisonia, Orthoceras, and Bathyurus. The deRcribed species ar.e Orthis electra?, Maclurea 

Feet. 

matutina?, and Orthoceras piscator .. _______ . ______________ : _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 100 

2. Strata concealed .. ____________________ . _________________ · _________________________________ 165 

265 

Division I of Logan's classification was placed by Billings in the Chazy, with 

some doubt, and is described in Chapter IV, together with divisions K to P inclusive. (See pp. 211-217.) 

Billings 81 classified the faunas and arranged them in a catalogue. Commenting 

on their distribution and relations, he states: 

POTSDAM GROUP. 

In this group consisting of divisions A, B, and C, we have 19 species, none of which are 

found in the Potsdam sandstone in Canada. But in that part of the group, which is usually 

known, in the State of Vermont, under the designations of the Red sandrock and the Georgia 

slates, the following occur: Scolithuslinearis, Palr£ophycus incipiens, Oboluslabradoricus, Obolella 

(Kutorgina) cingulata, Olenellus thompsoni, 0. vermontana, Conocephalites adamsi, and C. teucer. 

As these are the most abundant species in the formation, both in Vermont and Newfoundland, 

there can be little doubt but that the rocks in which they occur, in these two widely separated 

localities, are of the same age. * * * In the next overlying strata, division D, Lingula 

acuminata was found at Bay St. Barbes. I have compared the specimens from this locality 

with those that occur so abundantly in the upper part of the Potsdam in the township of 

Beverly, in Canada \Vest, and believe them to be perfectly identical. 

CALCIFEROUS FORMATION. 

The Calciferous formation is represented in Newfoundland by all the divisions from D to 

H inclusive. In this series of strata there are 63 species, of which the following 14 are found 

in Canada and New York: Stenopora fibrosa, Stromatopora rugosa?, Lingula acuminata, 

Euchasma blumenbachia, Pleurotomaria calphurnia, P. calcifera, P.laurentina, Murchisonia anna, 

Ecculiomphalus atlanticus, Orthoceras lamarcki, Piloceras canadensis, Bathyurus cordai, Asaphus 

canalis, and Leperditia turgida. Excepting S. fibrosa and B. cordai, all of these occur in the 

true Calciferous in Canada. B. cordai abounds in the same formation in New York. S. rugosa 

is doubtfully determined and is probably distinct from the Black River species of that name. 

The beds in which L. acuminata occurs in Canada are placed in the top of the Potsdam; but as 

Pleurotomaria canadensis and an orthoceratite are associated with it, perhaps these particular 

strata should be more properly referred to the base of the Calciferous, and they would then 

correspond to division D. Most of the species are found in divisions G and H, the upper part 

of the formation in Newfoundland. Two of the species (S.fibrosa and A. canalis) range upward 

into the Chazy, the former continuing to the Upper Silurian. The general aspect of the fauna 

is peculiarly that of the Calciferous, the most striking features being the great numbers of small 

Maclurea and species of Piloceras, the latter a genus which seems to have culminated in this 

particular period. 
• 

154 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

M-N 11. ROCKY MOUNTAINS OF CANADA. 

The stratigraphy of the Canadian Rockies was originally described by McConnell/59e who distinguished the Bow River and Castle Mountain groups. Walcott 859 

has recently studied these rocks and divided them into several formations. He 

says: 

Mr. McConnell proposed the name "Castle Mountain group" for the great series of limestones and shales between the quartzitic sandstones and siliceous shales of the "Bow River 

group" below and the superjacent Ordovician graptolitic shales on the west and Banff limestone on the east. This includes the upper portion of the Lower Cambrian fauna at the base 

and the lower portion of the Ordovician fauna.at the summit. The term "Castle Mountain" 

is useful for the series, but I think that local names can be applied with advantage to several 

of the formations of the "Castle Mountain group" as originally defined. The following table a 

gives the relative positions and thicknesses of the new formation names herein proposed and 

defined for the Canadian Rocky Mountain section: 

Cambrian formations of the Canadian Rocky Mountains. 

Formation. Character. 

Upper Cambrian. 

Sherbrooke formation ......... ·I Bluish-gray arenaceous, dolomitic, massive, and 

thin-bedded to shaly limestones, with a few 

oolitic layers and cherty inclusions. 

Paget formation................ Bluish-gray oolitic limestones, usually thinbedded. 

Bosworth formation ............. Arenaceous dolomitic limestones, massive, thin 

bedded, and shaly, with bands of purple and 

Middle Cambrian. 

gray siliceous shales. 

Eldon formation............... . Massive arenaceous, dolomitic limestones, with a few bands of purer bluish-gray limestone. 

Stephen formation.............. Limestones and shales, calcareous and siliceous. 

Cathedral formation............ Massive arenaceous and dolomitic limestone .... 

Lower Cambrian. 

Thickness (ftlet). 

Mount Mount 

Stephen. Bosworth . 

0 1,360 

0 360 

Not measured .. 1,855 

Not measured .. 2,733 

562 640 

1' 60().-1' 800 1, 595 

Castle 

Mountain. 

~--~--

0 

0 

0 

2,195 

366 

987 

Mount -Whyte formation [a] .... . Alternating bands of limestone and siliceous 315 390 248 

and calcareous shale. 

St. Piran formation (b] ......... . Mainly gray quartzitic sandstones, with a few 300 300+ 500+ 

bands of siliceous shale. 

Siliceous shales ................................ 1 • • • • • . • • • • • • • • • • • • • • • • • ••••.••• 

Gray quartzitic sandstones ................... ·[· .............. ·i ....... ·I· ...... . Lake Louise formation ......... . Fairview fonnation ........... . 

··-- -----

[a In the book cited, through a typographical error, the Mount Whyte formation was placed in the Middle Cambrian in the table on page 2, but the fauna was recognized by Walcott as Lower Cambrian, and is so termed on page 4.] 

[b The St. Piran and the two underlying formations compose the upper part of the Bow River group. In 1910 

Walcott found a conglomerate at the base of the "Fairview formation," recently renamed by him the Fort Mountain 

sandstone (Mon. U.S. Geol. Survey, vol. 51, 1912, p. 131), that marks an unconformity between it and the underlying 

part of the Bow River group, which is very much the thicker portion. He therefore regards the Bow River group as chiefly pre-Cambrian. (Personal communication.)] 

a The table as here printed is not an exact quotation but is made up from Walcott's paper.-B. W. 
CA:M:BRIAN AND LOWER ORDOVICIAN. 155 

Q 3. SEWARD PENINSULA. 

(See 0-R 2-8, Alaska, Chapter VII, pp. 353-354.) 

Q 5-6. ENDICOTT RANGE, NORTHERN ALASKA. 

(See 0-R 2-8, Alaska, Chapter VII, pp. 353-354.) 

S 27. EASTERN COAST OF GREENLAND. 

(See Chapter IV, p. 224, description by Nathorst.) 

T 17-18. ELLESMERE LAND. 

' The following notes on the occurrence of Cambrian and Ordovician strata are 

quoted from Schei: 5500 

At Cape Camperdown, on Bache Peninsula, is found granite overlain by an arkose-like 

conglomerate sandstone, in flat strata, the dip being north-northwest. Its thickness here probably does not exceed 500 feet, though the contour swells to considerably greater magnitude by 

reason of intrusions of diabase, occasioning an additional thickness of perhaps 300 feet. At its 

upper part this sandstone merges gradually, by interstratification, into a series of gray sandy 

and marl-like schists and limestone conglomerates. From a few inches up to a couple of yards 

in thickness these conglomerates and schists, continuously interstratified, build up a series 600 

to 900 feet in thickness, interrupted by two compact beds of yellowish-gray dolomitic limestone 

about 150 feet in thickness. These again are overlain by a series similar to the underlying one, 

excepting that here the limestone conglomerates exceed the schists. 

In a detached block, in all probability originating from one of the two 150-foot beds, were 

traces of fossils, of which one, Leptoplastus sp., can be identified. In another detached block, 

whose mother rock is not known, was found Anomocare sp. It may be said with certainty 

after the finding of these fossils that this series contains deposits of the Cambrian age. 

The second series of conglomerates is overlain by a light grayish-white limestone in a bed 

some 300 feet in thickness, observed in the midst of the section of Cape Victoria Head. Indistinct Orthoceras, Lichas, and Symphysurus assign this limestone to the Lower Silurian period. 

Above the Orthoceras-bearing light-colored limestone bed are some less extensive strata 

of alternating limestone and quartz sandstone, and finally a 100-foot bed of close brown limestone of which certain layers are fossiliferous and gave an Asaphus, traces of other trilobites, 

and some gastropods. 

Following the direction of the dip to the north side of Princess Marie Bay we find it again, 

though seemingly somewhat abrupter, in the limestone beds of Norman Lockyer Island. A 

fauna with Halysites sp., Zaphrentis sp., Orthisina sp., Rhynchonella sp., Leperditia sp., Illrenus 

sp., etc., assigns this limestone to Lower Silurian. It is again found with its fauna at the base 

of Cape Harrison; in this case with a thick superincumbent bed of marly sandstone, quartz 

sandstone, and finally extensive limestone conglomerate. 
CHAPTER IV. 

MIDDLE AND UPPER ORDOVICIAN. 

Color, light bluish purple. 

Symbol, 17. 

Distribution: General throughout the continent. In the Arctic mapped with the Silurian; in 

the Rocky Mountains of the United States included in narrow bands of Cambrian and 

lower Ordovician. 

Content: Early to uppermost Ordovician (Chazy to Richmond, inclusive). 

"Middle and upper Ordovician areas. 

H 13 ......................... Texas (mapped in part with Silurian) ...................................... . 

I 12-13 ....................... Arizona and New Mexico (mapped largely with Cambrian) .................. . 

I 14 .......................... 0 klahoma ............................................................... . 

I 15 .......................... Arkansas ................................................................. . 

I 16 .......................... Alabama, Georgia, and southeastern Tennessee ............................. . 

I-J 16-17 ..................... Ohio, Kentucky, and Tennessee ........................................... . 

J ll-12 ....................... Great Basin, Nevada and Utah ............................................ . 

J 13 .......................... Southern Colorado and New Mexico (mapped with Cambrian) ............... . 

J 15 .......................... Northern Arkansas (mapped with Carnbrian) ................... _ ........... . 

J 15-16 ....................... Missouri and southern Illinois ............................................. . 

J 16 .......................... Indiana ................................................................. . 

J 17-18 ....................... Maryland, Virginia, and east Tennessee ................................ _ ... . 

K 10 ......................... Taylorsville district, California (mapped with Devonian) .................... . 

K 12 ......................... ·wasatch and Uinta ranges, Utah (mapped with Carboniferous) ............... . 

K 13 ......................... Black Hills (mapped with Cambrian) ...................................... . 

K 16 ......................... Southeastern Wisconsin and northeastern Illinois ........................... . 

K 17-18 ...................... Pennsylvania and Kew Jersey ............................................. . 

K-L 12-13 .................... Wyoming and northern Colorado (mapped with Cambrian) .................. . 

K-L 15 ....................... Minnesota, northeJtstern Iowa, southwestern Wisconsin, and northwestern Illinms ................................................................... . 

K-L 17-18 .................... Ontario and New York .................................................... . 

K-L 18-19 .................... Vermont, New Hampshire, Massachusetts, and Connecticut east of the Green 

Mountains (not mapped) ................................................ . 

L 12 .......................... Southwestern Montana (not mapped) ...................................... . 

L 16 .......................... Upper Peninsula of Michigan ............................................. . 

L 17 •......................... Manitoulin Islands; Lake Nipissing, Lake Temiscaming, and Mattawa on the 

Ottawa (not mapped) ................................................... . 

L 18-19 ............. _ .......... St. Lawrence Valley, Carleton and York counties, New Brunswick (mapped 

with Cambrian) ........................................................ . 

M 11. ........................ Beaverfoot Range, Canadian Rocky Mountains (not mapped) ................ . 

M 19-20 ...................... Gaspe Peninsula; Mingan and Anticosti Islands ............................ . 

M 21. ............ ~ ........... Newfoundland, northern peninsula (not mapped) ........................... . 

M-N 14 ....................... Lake Winnipeg district, Manitoba ......................................... . 

0 9 .......................... Dease River, British Columbia (not mapped) ............................... . 

015 ......................... Southwest coast of Hudson Bay ........................................... . 

P-Q 3-7 ...................... Alaska (not mapped) ..................................................... . 

P-Q 17-19 .................... Southampton Island, Fox Land, and Ungava Bay (mapped with Silurian) .... . 

Q 3 .......................... Seward Peninsula (mapped with Cambrian) ................................ . 

R-T 1{}-20 ..................... Arctic Archipelago (mapped with Silurian) ................................. . 

S 27 .......................... Eastern coast of Greenland ................................................ . 

156 

Page. 

158 

158 

159 

160 

164 

165 

168 

169 

169 

169 

171 

173 

175 

175 

176 

176 

176-

179 

180 

183 

192 

194 

194 

195· 

196 

207 

208 

211 

217 

219 

220 

221 

221 

222 

222 

224 
FrGURE 6.-Sketch map showing the dis1ribution of middle and upper Ordovician rocks represented on the geologic 

map of Nor~h America and the key to references in the text. 

157 
158 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

H 13. TEXAS. 

In the· Caballos Mountains, southern Texas, is exposed an area of Paleozoic 

rocks from which Udden 819 procured Ordovician fossils. Other Paleozoic formations are probably represented. 

With reference to the Upper and Middle Ordovician in the district north and 

east of El Paso, Richardson 668a s,tates: 

The Montoya limestone also has been recognized by its stratigraphic position and fossils 

in both of the quadrangles [El Paso and Van Horn]. This limestone contains two distinct 

Ordovician faunas, the Richmond and Galena, and on paleontologic grounds it is desirable to 

separate the two, but the small thickness of the formation, only about 250 feet, and the scale of 

the maps will not admit of it. 

Fossils characteristic of the Galena occur in the lower part of the Montoya linestone, the 

zone being commonly marked in the El Paso quadrangle by massive dark-colored limestone 

containing little or no chert. The upper part of the limestone is prevailingly gray, but some 

of the beds are almost white while others are dark, and the two parts of the formation can not 

always be distinguished lithologically. The zone which carries the most abundant Richmond 

fossils in places is seamed with conspicuous bands of chert a few inches in thickness. In the 

Van Horn quadrangle the base of the Montoya limestone is commonly marked by the presence 

of thin-bedded earthy yellow and reddish limestone, but otherwise in both quadrangles the 

contact is apparently conformable. Like the El Paso limestone, the Montoya is characteristically magnesian. Mr. Ulrich has identified the following fossils from the Montoya limestone: 

Receptaculites oweni. 

Maclurina manitobensis. 

Maclurina acuminata. 

Streptelasma rusticum. 

Hemiphragma imperfectum 

Monotryprella quadrata. 

Strophomena :flexuosa. 

Leptama unicostata. 

Dinorthis subquadrata. 

Fossils from the Galena beds. 

I 

Hormotoma major. 

Ormoceras sp. undet. 

Fossils from the Richmond beds. 

Dinorthis proavita. 

Platistrophia acutilerata. 

Rhynchotrema capax. 

Orthis whitfieldi. 

Parastrophia divergens. 

In southwestern United States outside of the areas nere considered few Ordovician rocks 

are known. The system apparently is not represented by sediments in either the Grand Canyon 

or Bisbee districts. The Longfellow formation in the Clifton quadrangle, Arizona, probably 

should be correlated with the El Paso limestone as well as a part of the Ordovician limestone 

in the central Texas region. Recently several small areas of Ordovician rocks have been 

reported in central New Mexico by Gordon and Graton.a Mr. Ulrich reports that the Beekmantown fauna of the El Paso limestone is of the type prevailing in the Wichita Mountains, 

Oklahoma, in the upper 1,000 feet or so of the Arbuckle limestone; and that the Galena and 

Richmond faunas of trans-Pecos Texas are similar to those in the Mississippi Valley, Oklahoma, 

the Black Hills, the Bighorn Mountains, and elsewhere. 

•2-13. ARIZONA AND NEW MEXICO. 

The interval correspo~ · ng to the Ordovician appears to be represented throughout most of Arizona only by a parting between two limestones containing Middle 

Cambrian fossils. 657 • 

658a These relations resemble those of the Grand Canyon section. 

a Am . .Jour. Sci., 4th ser., vol. 21, 1906, p. 190. 
MIDDLE AND UPPER ORDOVICIAN. 159 

Near the eastern boundary of Arizona, in the Clifton district, 541 a the Longfellow 

limestone represents the early Ordovician ("Calciferous,'' Ulrich) and possibly 

some Upper Cambrian, but the later Ordovician is lacking. 

The Ordovician of New Mexico is described by Gordon and Graton 372 as 

comprising the equivalent of the lower Ordovician and also limestones which carry 

a distinct Richmond (uppermost Ordovician) fauna. Fuller descriptions are given 

by Lindgren. 542 

I 14. OKLAHOMA. 

In the Arbuckle Mountains of Oklahoma Ordovician strata are represented 

by the Arbuckle limestone (Upper Cambrian and early Ordovician; see pp. 82-83, 

Chapter III), the Simpson formation (of Chazy or Stones River age), and the Viola 

limestone (of Black River to Richmond age). Taff and Ulrich sosa give the following account of the stratigraphy and correlation: 

After the Arbuckle limestone was deposited there was a general change in the nature of 

the sediments. The top of the limestone seems to have been slightly eroded locally and upon 

the surface were deposited beds of pure sand. At other places the Arbuckle limestone is overlain by shaly and impure lime-the basal beds of the Simpson formation. On these local sandy 

beds at the base there were deposited greenish shales and thin crystalline and shelly limestones 

interstratified with a number of beds of sandstone, making a total thickness ranging from about 

1,200 to 2,000 feet. 

A generalized section measured on the south side of the Arbuckle uplift gives 

the following beds: 

Feet. 

Thin limestone and shale. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 890 

Sandstone .............................................................................. 100-200 

Thin-bedded limestone and shale, with some sandstone................................... 1,250 

The sandstone separates the formation into two divisions, regarding which 

Taff and Ulrich say: 

The fauna of the lower division of the Simpson formation is decidedly similar to that of the 

Chazy of New York and Canada and of the Pogo nip formation of Nevada. Considering these 

east and west connections, it is surprising to note that the lower Simpson fauna, so far as known, 

contains none of the prolific fauna of the lower division (Murfreesboro limestone) of the Stones 

River group in middle Tennessee, which is believed to be of aquivalent age. As a whole, the 

fauna of the upper part of the Simpson is closely related to the upper division of the Stones River 

group in Tennessee and Kentucky and the equivalent beds in the upper part of the Mississippi 

Valley. 

The description of the Viola limestone follows and comprises the items quoted 

below: 

There is a gradual transition from the top of the Simpson formation up into the basal part 

of the Viola formation. The top layers of the Simpson are usually argillaceous, are thinner, 

darker, and more evenly stratified than those at the base of the Viola, and in places contain 

partings and beds of clay. Therocks at the contact on each side, hr-1 c,ver, vary somewhat in 

different parts of the field. . 

The Viola formation is a continuous but slightly variable der'. _,{ of limestone 500 to 700 

feet thick, which usually appears massive on very fresh exposures. 'Upon weathering, however, 

the bedding is pronounced, showing layers rarely more than a foot in thickness. In the lower 

and middle parts especially there are occasional bands and nodular masses of chert. 

The Viola limestone is divisible into three members, distinguished by variations in bedding, 

in texture, and to a less extent in the color of the limestone. The upper and middle members 
160 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

are approximately 300 feet thick. The lowest member is somewhat thinner and more variable 

than the others. The lowest member consists of light-colored, coarse-textured, and usually 

roughly bedded limestone: It probably will not exceed 100 feet in thickness anywhere, and in 

places is much less. 

The middle member consists of white to light-blue and generally even-· and thin-bedded 

limestone. On account of the abundance of fossil trilobites of the genus Trinucleus in certain 

layers it might be known as the Trinucleus member. It is characterized by white surface where 

weathered and even bedding. * * * 

An investigation of the fossils by Mr. Ulrich, who collected and studied the rock section, 

shows that there are three faunal divisions, which correspond to the three lithologic members 

above described. The most fossiliferous development of the basal member was noted at the 

extreme n.orthern occurrence, in the region at the base of Double Mound, 6 miles northeast of 

Roff. A preliminary study of the fossils collected shows [a large number of species, nearly all 

of which] occur in Phylloporina and Clitambonites beds of the Ordovician section in Minnesota. 

These beds are correlated with latest Black River and earliest Trenton. Many of the species 

occupy these horizons in New York and Canada and what are regarded as equivalent positions 

in middle Tennessee and Kentucky. 

As a whole the middle member or Trinucleus bed of the Viola limestone is not abundantly 

fossiliferous. The organic remains occur chiefly in three horizons, one near the base, another 

above the middle, and the third near the top. The first and second contain an abundance of 

graptolites. Next to the Trinucleus the graptolites are the most characteristic and commonest 

fossils of the middle member. The fossils indicate that the Trinucleus beds were deposited 

during the latter half of the Trenton age. 

The upper member of the Viola limestone is approximately 300 feet in thickness, but only 

in the upper 25 feet is it abundantly fossiliferous. The lower 50 feet yielded no fossils. In the 

middle portion the fossils are not only rare but poorly preserved. The fossils are all species 

characterizing the upper divisions of the Richmond age in Minnesota, Wisconsin, Illinois, 

Indiana, and Ohio. In northern Arkansas the same fauna occurs in the Polk Bayou limestone 

and in middle Tennessee in the Fernvale formation. 

I 15. ARKANSAS. 

Purdue 655 has recently published the results of studies of the stratigraphy of 

the Ouachita Mountains, in Arkansas, as worked out by himself and Ulrich: 

Feet. 

Carboniferou~: Stanley shale ......... ____ . ___________________________________ . _. _ _ _ _ _ _ _ __ 6,000 

Unconformity. 

Age unknown: 

Fork Mountain slate. _____ ._. _____ . __ .______________________________________________ 100 

Arkansas novaculite. ___ .. _. ______ . _ . ____ .. _ . ___________ . _ . _ . ____ . __________________ . 800 

Missouri Mountain slate ... _ . ______ .. __ . __________________________ . __ . _ . ___ ... _____ .. 300 

Probable unconformity. 

Ordovician: 

Blaylock sandstone .......... _ . _ ....... _ ... ___ . _______ . __ . _ . _ ... _ . ______________ . _ . _ . 1,500 

Polk Creek shale ___________________ . _ .. ____________ . _ .. ______ . _ . ________________ . .. 100 

Bigfork chert.. ____ . _ .... __ . __ . ____ ...... _____________ ... _ ... ___ .. __ . _ . ___ . _______ . . 700 

Stringtown shale __ . __ .. __ ... __ . __ . _______ . __ .. __ . _____ . _ . _____ . __ ..... ________ . __ . __ 100 

Unconformity. 

Ouachita shale ..... __ .. _ ........ ___ .. _____ ._ ..... _ ............................. _. __ . 900 

Crystal Mountain sandstone ............. ____ ... _ ................................ _.... 700 

Probable unconformity. 

Age unknown: Collier shale (observed thickness) ... ______ . __ . __ . . __ . __ ....... __ ..... __ . . . 200 

1L400 

The Collier shale was considered by the Geological Survey of Arkansas as of Lower Silurian 

(Ordovician) age. a Some of the older rocks above this shale are certainly of Ordovician age, as 

a Geol. Survey Arkansas, vol. 3, 1890. 
MIDDLE AND UPPER ORDOVICIAN. 161 

is shown by the fossils they contain; and the Crystal Mountain sandstone, the formation immediately above, is considered Ordovician on lithologic grounds. But careful search has failed 

to reveal any fossils in the Collier shale, nor has it any lithologic characters that would give it 

claim to an age classification with the overlying rocks. On the other hand, it is quite different 

from the rocks above, and at its top there is at least locally a conglomerate which future study 

may determine to be widespread. For these reasons, it is thought best not to even provisionally 

place this with the Ordovician. It may be Cambrian. 1J so, these are the oldest outcropping 

rocks in the State. * * * 

It is a dark, soft, graphitic clay shale, containing widely separated thin beds of dense black 

and intensely fractured chert. As a result of the severe squeezing and shearing it has undergone practically all traces of bedding have disappeared. It is intensely crumpled and is full of 

glossy, slickensided surfaces. In places slaty cleavage may be observed. The upper 100 feet 

or more is quite calcareous, limestone occurring in dark-colored crystalline lenses and layers 

one-half inch or more in thickness, distributed through the shale. In other parts the limestone is several feet in thickness and occurs in much contorted layers from a few inches to more 

than 2 feet thick, interbedded with thin seams of graphitic shale. In such cases the limestone is dark and compact, is much jointed, and on long exposure weathers in very uneven 

surfaces. * * * 

The rocks of known Ordovician age within the Ouachita Range include five formations, 

which are here known as the Crystal Mountain sandstone, the Ouachita shale, the Stringtown 

shale, the Bigfork chert, the Polk Creek shale, and the Blaylock sandstone. 

The Crystal Mountain sandstone consists of two parts~a lower massive one compoE!ed 

wholly of sandstone, 300 feet thick, and an upper part consisting of rather massive layers of 

sandstone interbedded with black to gray shale, 400 feet thick. The shale is in places altered 

to ribboned slate, like the lower part of the Ouachita shale. The lower part is the main rock 

of the Crystal .Mountains, which owe their existence to this massive, slow-weathering formation. 

It is a coarse-grained white sandstone, composed of well-rounded grains, and commonly weathers 

to the color of brown sugar. In many parts it is thickly set with a network of quartz veins 

from the thickness of a knife blade to several inches. In other parts there are fissures from 

several inches to several feet in width, the walls of which are lined with magnificent clusters of 

quartz crystals. * * * 

This formation has not to the present time produced any fossils, and it is considered of 

Ordovician age wholly on lithologic grounds. The sandstone passes gradually into the Ouachita shale above, and the close resemblance of the included shale beds to the Ouachita shale 

seems to the observer in the field conclusive evidence that the two are of the same age. 

The Ouachita shale is the next formation above the Crystal Mountain sandstone, into 

which it passes by gradual increase of sandy layers. * * * The formation is intensely 

crumpled, and for that reason its thickness has not definitely been made out, but it probably 

is not less than 900 feet. 

For the most part this is a dark-colored clay shale, but not uncommonly the dark layers 

alternate with green ones. In many places slaty cleavage is developed, when the alternating 

layers of dark and green produce ribboned slate. Somewhere in the lower portion there are 

thin layers of limestone, interbedded with the shale. Quartz veins and thin layers of hard 

flinty material are common, and fragments of quartz frequently occur on the ground where 

this is the surface rock. The shale is frequently dissected by straight, well-defined joints. 

Graptolites, while not so common as in the shales above, are frequently to be found. 

The Stringtown shale in Arkansas rests unconformably upon the Ouachita shale and is 

from 75 to 150 feet thick. It consists of two parts, a lower calcareous part and an upper shaly 

part. The lower part of the formation contains lenses of bluish compact brittle limestone, 

usually thickly set with calcite veins. The basal portion of this is sometimes conglomeratic, 

the pebbles ranging from the size of peas to 2 inches in diameter and subangular. They consist 

of shale, very fine grained brown sandstone, and limestone. * * * 

48011°--12----11 
162 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The maximum observed thickness of the limestone lenses is about 75 feet. They are 

made up of layers from a few inches to 2 feet in thickness and they may thin down to a few 

feet or entirely disappear, within very short distances. The rapid thickening and thinning 

of the limestone, its sporadic occurrence, the conglomerate it contains, and the lithologic differ-' 

ence between the shale of the formation and that beneath led to the conclusion in the field 

that there is an unconformity between the two formations, which afterward was confirmed on 

paleontologic evidence by Mr. E. 0. Ulrich. The irregular occurrence of the limestone is due 

to its having been put down in the valleys of the old land surface, and the pebbles of the conglomerate at the base of the limestone doubtless were carried in by the streams flowing over 

that surface. 

The upper or shale portion of the formation usually is from 50 to 75 feet thick. It is a 

very black shale and is soft enough to soil the fingers in handling, qualities due to the presence 

of a large per cent of finely disseminated graphite. In places the graphite is conspicuous and 

occurs in thin, wavy sheets. While most of this part of the formation is shale, there sometimes 

occur in it, especially near the top, thin beds of dark-colored chert, very similar to the Bigfork 

chert, next to be described, as well as thin layers of limestone. Some of the shale layers are 

quite calcareous, and when the lime is dissolved out from these, there remains a gray to pink 

colored porous, spongy shale, fragments of which are frequent on the slopes. Fossil graptolites 

abound in the shale of this formation and occur sparingly in the limestone. 

The Bigfork chert is a very close textured, even-bedded siliceous rock, in layers from 1 to 

18 inches thick, but the most common thickness is from 3 to 6 inches. * * * The color 

varies from a slate to a dark gray, the former being most common. It is very brittle and 

under the blows of the hammer flies into small pieces. The fracture is angular, in some of 

the layers approaching conchoidal. In places it is thickly set with a network of fine quartz 

veins. It is along these veins that the stone breaks when struck with a hammer, and so numerous are they that it often is difficult to secure a hand specimen with fresh surfaces. Straight 

joints several inches in length with remarkably smooth surfaces are common. Weathered 

portions have the appearance of fine-grained gray weathered sandstone. Usually the layers 

are crumpled to an astonishing degree, and it probably was the strain accompanying this 

intense folding that caused the network of thin joints, which subsequently were filled with 

quartz, forming the veins above described. Its thickness is about 700 feet. 

This formation is mapped by the Geological Survey of Arkansas a as novaculite, but it 

differs materially from the true novaculite of the area in being of a coarser texture, darker 

color, thinner bedded, not translucent, older, and in having a much more complex structure. 

The Polk Creek shale overlies the Bigfork chert, with which it is conformable, and outcrops 

along the bases of many of the ridges in the Ouachita Range. In color, hardness, and texture 

this shale is much like the Ouachita shale. It resembles that also in containing a large number 

of quartz veins and locally in having slaty cleavage well developed. In this, as in the Ouachita 

shale, graptolites abound. It differs from that shale in containing no sandy or calcareous 

layers and in being only about 100 feet thick. In places it appears to be absent. 

The Blaylock sandstone is well exposed at the eastern end of the mountain, where the 

Little Missouri River cuts across the exposed edges. Like the other formations described, it 

is extremely crumpled. The repetition of beds resulting from the crumpling renders its thickness difficult to determine, but this is thought to be about 1,500 feet in the thickest part. Apparently it is conformable with the Polk Creek shale beneath. In parts, through a hundred feet 

or more, it consists almost wholly of sandstone, while in other parts it is made up of alternating 

beds of sandstone and shale. The sandstone is in layers that usually are from 1 to 6 inches 

thick, and the bedding is very even. Some of the layers are quite quartzitic and contain 

numerous thin quartz veins. Others of the thin layers closely resemble chert. It is fine 

grained to medium grained, and varies from dove-colored to dark gray or green. Graptolites 

occur in it rather sparingly. The interbedded shale is dark colored, often black, and fissile. 

In places it contains large numbers of graptolites. -------------------------

a Geol. Survey Arkansas, vol. 3, 1890. 
MIDDLE AND UPPER ORDOVICIAN. 163 

The exact stratigraphic relations of this formation are not at present understood. The 

only area in which it has been carefully studied is in the southern part of Montgomery and 

Polk counties, where it outcrops over an east-west belt about 3 miles wide, and from which it 

thins northward until it is only a few inches to a few feet thick where it outcrops on the north 

slope of Caddo Mountain. That the formation is absent north of Caddo Mountain is known, 

for the horizon at which it occurs is widely exposed. Whether the sudden appearance and 

rapid thickening as we pass southward is due to its having been put down in a trough, or to 

an erosion interval during which that part to the north was removed, will require further field 

work to determine; but its much contorted condition and its relations to the overlying formation, later to be described, impress one with the strong conviction that probably it is due to 

an erosion interval. * * * 

From recent work it appears that 'the age of the Missouri Mountain slate, the Arkansas 

novaculite, and the Fork Mountain slate can not yet be determined, for no fossils have been 

found in them a by recent workers in the area. They may be of Ordovician age, they may "be 

Silurian, and they may be Carboniferous. Their lithologic character is so very different from 

the nearest rocks of Devonian age (coarse-grained sandstones and black shales), which occur 

in northern Arkansas, that the possibility of their being of that age is scarcely entertained. 

On the other hand, their siliceous character might easily permit them to be considered contemporaneous with either the Ordovician limestones of the Ozark region, which contain a great 

deal of chert, or with the Boone formation (Mississippian) of that region, which is largely and 

in parts entirely chert. The representative of the Silurian in northern Arkansas is the St. Clair 

limestone, which contains no chert. * * * 

The Missouri Mountain slate, where the Blaylock sandstone is present, rests upon that 

formation; where that is absent, it rests upon the Polk Creek shale at all points where contacts 

were observed. While it partakes of the large and comparatively gentle folds of the area, it 

appears not to enter into the minute crumpling of the Blaylock sandstone and lower formations, 

but on the contrary to rest upon their upturned and what seem to be eroded edges. .Whether 

it does or not has thus far eluded all efforts to determine, on account of the great amount of 

debris nearly always present on the slopes where the contact between the two formations would 

otherwise be exposed. 

This formation varies from 50 feet and less to 300 feet in thickness, the thinnest part being, 

so far as observed, along the southern border of the Ouachita Range. The formation is a 

clay slate. A few feet of the basal portion usually is green. Locally this lower portion is 

somewhat sandy and such parts contain small crysta1s of iron sulphide. The remainder, above 

the basal portion, varies from a blood-red to a dark red, containing patches and streaks of 

green. The green at the base may be the original color, but that above is secondary. * * * 

The Arkansas novaculite is the principal formation of the Ouachita Range. Owing to an 

unconformity at the top, its thickness is quite variable, but the maximum observed is about 

800 feet. The character of the formation varies from the base to the top, as well as in different 

parts of the same horizon. In a general way it may be described as consisting of a lower, 

heavy-bedded siliceous part that is wholly novaculite and an upper, thin-bedded part of the 

same material, interpolated with thin layers of black soft shale. In places there is an intervening 

portion containing sandstone. 

The lower portion is about 3,00 feet thick and consists of massiv~ beds from 2 to 10 feet 

thick, with large ripple marks showing along the bedding planes. This part of the formation • 

furnishes the abrasives that are known in the markets as the Ouachita and Arkansas stone. 

It is a very close textured rock, the grains being of microscopic size. The common color is a 

very light gray, but bluish tints and pink, black, and dove-colored spots are quite common 

in the lower 50 to 7 5 feet. The fracture is uneven to conchoidal, and it is very brittle. In 

a Prof. L. S. Griswold, in the report of the Geological Survey of Arkansas, vol. 3, 1890, pp. 404-407, names several 

localities in which graptolites were supposedly obtained from above the novaculites. Several of these localities were 

visited by Mr. H. D. Miser, who reports that in each case the graptolites occur above the Bigfork chert instead of above 

the novaculite. 
164 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

luster it is often waxy, and thin edges frequently are translucent. The bedding is quite irregular, 

small lenses between the beds being very common. * * * 

The upper portion, in those parts where it is all present, is much thicker than the lower. 

It consists of layers of novaculite the most common thickness of which is from 1 to 6 inches, 

interpolated by layers of shale that is very black and soft when unaltered. When weathered, 

this shale is brown to green in color, producing a banded effect. The novaculite layers usually 

are dark to black but lithologically are not otherwise very different from the massive novaculite 

beds of the lower part of the formation. This part of the formation is frequently and sometimes 

wholly removed, as a result of an unconformity between it and the Carboniferous rocks that 

rest upon it. 

The Fork Mountain slate, when present, lies at the top of the Arkansas novaculite, and is 

about 125 feet thick. On account of the unconformity above mentioned, it is only locally 

present, having in many places been removed by erosion. * * * 

This formation consists of gray to greenish and chocolate-colored slates, containing thin 

layers of quartzite in the lower part. 

I 16. ALABAMA, GEORGIA, AND SOUTHEASTERN TENNESSEE. 

The classification and synonymy of the Ordovician worked out by Hayes 417 in 

the southern Appalachian region is: 

Ordovician rocks in southern Appalachian region. 

~ames hitherto applied to the same rocks. 

Period. Formation names used 

in report. Smith, Geology of valley 

region adjacent to Cahaba 

coal field, 1890. 

Smith, Outline of the 

geology of Alabama, 

1878. 

Safford, Geology of 

Tennessee, 1869. 

I 

;-~-~~~-~r::~-slate ..... -.-.. -.: -_-.---_ . ~~~- ~ _-_-_ -.. -. -_ .-.. -. ~ .. -C-in_c_in~n~~-i o-r-N-ash-v-il-le-. r-N-as_h_v~--n-e-. ----· 

@.~ I 

·s·~ Chickamauga limestone. TrentonorPelhamlime- Trenton, Chazy or :S ..§ stone. Maclurea. · 

w "' Knox dolomite ......... Knox dolomite ......... Quebec or Knox dolo- 2. mite. 

Trenton or Lebanon 

Maclurea limestone. 

Knox dolomite. 

The stratigraphic relations and distribution of the formations are described 

in the Stevenson, Gadsden, and Chattanooga folios of the Geologic Atlas of the 

United States, according to the divisions which have been carefully worked out 

as lithologic units. Recent paleontologic studies by Ulrich and Bassler, not yet 

published, appear to lead to the discrimination of several paleontologic facies and to 

correlation with the Stones River and other established horizons of the Mississippi 

Valley and New York sections. 

A recent study of the Birmingham district107a has resulted in the following • lithologic distinctions: 

Feet. 

Silurian: Clinton (Rockwood) formation. . . .. . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250-500 

Unconformity. 

Ordovician: Chickamauga (Pelham) limestone ......................................... 200-1,000 

Unconformity. 

Cambro-Ordovician: Knox dolomite (includes at base Ketona dolomite member, 600 feet) . . 3, 300 

Cambrian: 

Conasauga (Coosa) limestone...................................................... 1,000 

Rome (Montevallo) formation (great thickness). 
-------------------------------------

MIDDLE AND UPPER ORDOVICIAN. 165 

In these systems there are included the R'ome (Montevallo) formation and the Conasauga 

(Coosa) limestone, both of known Cambrian age; the overlying Knox dolomite, the lower part 

of which is regarded as Cambrian and the upper part Ordovician, though the plane of division 

between the Cambrian and Ordovician is unknown; and the Chickamauga (Pelham) limestone, 

of known Ordovician age. 

The lowest Cambrian rocks exposed in this area are limestone and shale, possibly 1,000 to 

1,500 feet thick, so far as can be judged from the width of outcrop in Opossum Valley. These 

rocks have been designated the Conasauga limestone by the United States Geological Survey 

and the Flatwoods or· Coosa formation by the Alabama Geological Survey. · They consist of 

thin-bedded blue limestone interbedded with shale, which in some sections, as in the vicinity of 

Bessemer, carries considerable chert in thin layers. This limestone is underlain by a mass of 

shale of great thickness, which to the east is known as the Rome formation. Locally it has 

been called the Montevallo shale. In this report it is called the Rome formation. 

The Knox dolomite includes the rocks between the Conasauga and the Chickamauga 

(Pelham) limestone. In the Birmingham region and other parts of Alabama the lower part of 

the formation is almost free from chert, and on account of both this lithologic difference and its 

economic importance it has been separated out as a member from the mass of the Knox and 

named the Ketona dolomite member. The name Ketona is chosen because of the extensive 

quarry in this member at Ketona. The Ketona dolomite overlies the Conasauga (Coosa) limestone with apparent conformity and is 500 to 600 feet thick along Opossum Valley east of 

Birmingham. It is a nearly pure dolomite, with but little chert. It is thick bedded, crystalline 

in texture, and of prevailingly light gray color. From it is drawn most of the fluxing rock used 

in the Birmingham furnaces. * * * 

The rest of the Knox dolomite, 2,700 to 2,800 feet thick, overlies the Ketona dolomite 

member conformably. It is composed of dolomite with chert layers, which in places reach a 

thickness of 10 feet or more. Possibly one-fourth of the formation is chert. 

Overlying the Knox dolomite unconformably is the Chickamauga limestone, of Ordovician 

age. It is the same as the Trenton or Pelham limestone of the Alabama Geological Survey. 

In Birmingham Valley this is a thin-bedded bluish to dove-colored limestone ranging generally 

from 200 to 500 feet thick. It has been used for flux to some extent. 

1-J 16-17. OHIO, KENTUCKY, AND TENNESSEE. 

The well-known areas of Ordovician strata exposed on the Cincinnati and 

Nashville domes in Ohio, Kentucky, and Tennessee are mapped from the respective 

State geologic maps. The terranes comprise the oldest sediments exposed, namely, 

Middle Ordovician limestones of the Stones River group and others of Trenton age 

and the overlying Cincinnatian series (Upper Ordovician), consisting of strata of 

Utica, Lorraine, and Richmond age. They are thin limestones and shales, which 

are inconstant in thickness and faunal content. 

In Ohio Orton 620 distinguished the following beds: 

Cincinnati group of southwestern Ohio. 

Feet. 

Lebanon beds .............................................................................. 293 

Cincinnati beds proper: 

Hill Quarry beds ...... ____ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ] 25 

Eden shales .. ___ ........ _____ ........... _.:._ .................................... 250 

River Quarry beds................................................................. 50 

425 

Point Pleasant beds........................................................................ 50 

The Point Pleasant formation was subsequently, by Winchell and Ulrich, 944a 

shown to be of Trenton age and to be "terminated above with a heavy current-

-formed crinoidal layer, which includes large pebbles and disturbed masses of the 
166 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

underlying limestone layers and exhibits other evidences of unconformity by 

erosion" with the overlying shales. In the report just cited the authors state: 

The strata of the Cincinnati period as exposed in Ohio, Indiana, and Kentucky are divisible 

into three groups, having about the same geological value as the Chazy, Stones River, Black 

River, and Trenton groups of the Trenton period and the Medina, Clinton and Niagara groups 

of the Niagara period. These three divisions correspond very nearly with the Lower, Middle, 

and Upper Hudson of the Kentucky geologists, and the Eden shales, Hill Quarry beds, and 

Lebanon beds of Prof. Edward Orton in volume 1, Geology of Ohio. 

At Cincinnati we begin the period with the Utica group, which here consists of over 250 

feet of grayish and blue calcareous shales and marls, in which many layers of more or less 

crystalline limestone, from 1 to 20 inches thick, are included. The lower 14 or 20 feet of this 

division are of a darker color than the succeeding shales, being greenish gray or drab rather 

than light blue. 

It is this portion that agrees best in all respects with the Utica of New York and Canada, 

and it was so determined by Prof. James Hall as early as 1842. The gray shales contain more 

or less abundantly such widely distributed and characteristic Utica fossils as Triarthrus becki, 

Primitiella unicornis, Leptobolus insignis, Lingula daphne, Dicranograptus ramosus, Diplograptus 

spinulosus, D. putillus, Dendrograptus simplex, and D. tenuiramosus. Of these, the last three, 

as well as many other species, continue into the main body of the shaly strata of the group. 

Throughout, fossils, Bryozoa especially, occur in greater abundance, variety, and perfection 

than at any other known locality for the Utica. At the top the shales pass rather gradually 

into the "Hill Quarry beds." 

The latter, for which we propose to use the name Lorraine group, are clearly equivalent to 

the greater part of the New York strata which Emmons included under that name.a At the 

base of the division, which at Cincinnati comprises about 200 feet of strata, there are some 

arenaceous layers that on weathering frequently preserve the fossils as casts. Above these 

there are numerous layers of crystalline limestone, 3 to 10 inches in thickness, separated by 

relatively thin bands of shale. In the upper 60 or 70 feet the bedding is more irregular and the 

limestone layers thinner and generally argillaceous, unfitting them for building purposes. 

Fossils are well preserved and exceedingly plentiful and among them may be recognized nearly 

every species that has been described from the equivalent beds in New York. Perhaps 300 

species of fossils are known from the Cincinnati exposure of the Lorraine group and of these at 

least two-thirds are limited to the group, which is, considering the very similar lithological 

characters of the preceding and succeeding beds, a surprisingly large percentage. 

Resting on the Lorraine there is a series of alternating thin-bedded shales and limestones 

and in some localities finally a sandstone, in all quite 350 feet thick in southwestern Ohio and 

southeastern Indiana. Almost the entire series is excellently exposed at Richmond, Ind., so 

that the name Richmond group which we propose to apply to the series is eminently appropriate. 

East and southeast of Oxford in Ohio the whole group consists of thin-bedded limestones and 

shales, but at Richmond the upper part shows an increase of arenaceous matter while the uppermost layers of shale have become harder and include one or two heavy beds of impure limestone. 

Southward from this locality in Ripley and Jefferson counties, Ind., the heavy layers are 

increased. In the last county their texture is very compact and the color a drab or dove, 

reminding one in both respects very greatly of some beds of the Trenton period. In Indiana 

and Ohio this upper part of the group is, as a rule, not very fossiliferous, but when the bed is 

traced over into Kentucky it becomes a veritable coral reef reaching from Jefferson County, Ky., 

to and beyond Marion County. The rock in this distance,has changed some, being in the last 

county of a yellowish color and finely arenaceous texture, the whole giving way very readily 

under the weather so that the surface is sometimes thickly strewn with masses of Columnaria, 

Tetradium, Labechia, and Beatricea. 

a We refer particularly to Emmons's Lorraine sandstone, the greater part, if not all, of his Lorraine shales, which 

Walcott in 1879 referred to the Utica, being probably equivalent to the upper part of the Utica at Cincinnati. 
-----------------------

MIDDLE AND UPPER ORDOVICIAN. 167 

Foerste 339 gives the history of the classification of the Cincinnatian series and 

describes its representatives in the Tennessee Valley and thence south to the central 

basin of Tennessee. He concludes with the following list of local formations: 

According to the preceding observations, the Ordovician exposures in the valleys of the 

Tennessee River, the Buffalo River, Swan Creek, and South Harpeth Creek suggest the following 

lithologic succession, in descending order: 

Cincinnati group: 

Richmond: 

Mannie shale. 

Leipers creek limestone. 

Lorraine: 

Warren limestone; clay rock at Newsom. 

Swan Creek limestone. Richly fossiliferous Lorraine limestone in the eastern part of the area 

studied, containing Platystrophia lynx. 

Utica: Saltillo limestone. 

The Lorraine appears to become thinner west of the Cincinnati anticline, so as to be represented by thinner sections or so as to be entirely absent along the Mississippi in Missouri and 

adjacent Illinois, in the Wells Creek basin in northern Tennessee, and along the Tennessee 

River in southern Tennessee. The Richmond also appears to become thinner west of the 

northern half of the Cincinnati anticline. It becomes thinner also southward along the flanks 

of the anticline. In some parts of Tennessee it is entirely absent along the western flank of 

the anticline. West of the southern half of the anticline, in Tennessee, the thickness of the 

Richmond appears to vary irregularly. 

Details of the distribution of the Ordovician strata, with numerous graphic 

sections, are given by Foerste 338• 

340 in subsequent articles. 
168 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The Ordovician strata of the central basin of Tennessee have been minutely 

mapped and described by Hayes and Ulrich, ma who give the following classification 

and correlation with Safford's nomenclature: 

-· ~-- ---·-- -------------,-------------,----------

Safford and Killebrew, Ele~ I Generalized time scale 

for central N or t h 

America. 

I 

I Richmond. 

M a p p a b I e lithologic 

equivalents in the 

Columbia quadrangle. 

Fernvale formation. 

(Wanting.) 

ments of the geology of Ten~ Safford, Geology of Tennessee 

nessee, '1900. Middle Ten~ 1869. Middle Tennessee. ' nessee. 

Upper Nashville. 

i 

~~---L-,-,r-ra_i_n_e_.-___ - __ -__ -~~-- ~~~~;~;~~f:r:~:~~~-.-~~----~~' Hudson (College Hill; Cincin~ · _ _ nati). Includes Hudson phos~ 

-----~-~~----------------~--~- ph ate. 

' Frankfort. 

(Wanting.) 

Utica. 

-~------- ---~--~~-----------~-~~-~~~~~-

;::: Trenton. 

-~ 

.;: 

:--

0 

"0 

0 '" 

I Black River. 

I 

Stones River. 

Catheys limestone. 

Bigby limestone. 

(f) (g) C y r to donta 

and Stromatopora 

beds. 

(d)(e) Dove and 

Ward limestones. 

(c) Capital limestone or Mount Pleasant 

phosphate. ~--- ---------

Hermitage formation. 

(Wanting.) 

----------- ------------------~1 

Carters limestone. 

Lebanon limestone. 

(Not exposed.) 

(b) Orthis bed. 

(Not classified.) 

(a) Carters limestone. 

Lebanon limestone. 

Ridley limestone. 

Pierce limestone. 

Murfreesboro lime~ 

stone. 

Nash~ 

ville 

(Trenton). 

Stones 

River 

Middle Nashville. Nashville. 

Lower Nashville 

( Ortlt.is bed) . 

Carters Creek limestone. 

Glade limestone. 

Trenton or 1--------1 Lebanon. 

Ridley limestone. 

(Chazy). Pierce limestone. 

Central limestone. 

J 11-12. GREAT BASIN, NEVADA AND UTAH. 

A zone containing Trenton fossils is distinguished at Eureka, Nev., in the base 

of the Lone Mountain limestone, which is unconformable to the Eureka quartzite 

below. The limestone is 1,800 feet thick and is all of Ordovician age. Fossils found 

in the upper part were assigned to the "Upper Silurian" by Hague/91 but they are 

now regarded by Ulrich a as of Richmond age (uppermost Ordovician). The distribution of the Lone Mountain limestone is not well known. The limestone or its 

a Personal note. 
MIDDLE AND UPPER ORDOVICIAN. 169 

equivalent may occur in any of the ranges where the Cambrian and Ordovician are 

mapped together or where the Silurian is shown, throughout Nevada and western 

Utah. 

Ulrich a regards part of the Lone Mountain limestone as much older than the 

Bighorn dolomite and Whitewood limestone of Wyoming or the Harding sandstone 

and Fremont limestone of Colorado. According to Kindle 498 the beds which have 

been classed as Silurian, on account of containing Halysites catenulatus, may in 

general be regarded as possibly Ordovician, and Ulrich states that Halysites occurs 

generally in the West in faunas which are regarded as of Richmond age but is also 

known in faunas which are correlated with late Black River horizons. 

J 13. SOUTHERN COLORADO AND NEW MEXICO, 

Throughout much of southern Colorado, New Mexico, and Arizona Ordovician 

rocks are generally lacking and the hiatus corresponding with the period also comprises earlier and l~ter epochs, down to the pre-Cambrian and up to the Carboniferous, over extensive areas. Ordovician deposits along the shores of the Colorado 

land constitute the Harding sandstone and related formations. At Canon City, the 

type locality, the sandstone rests on Algonkian strata, is 86 feet thick, and is overlain by the Fremont limestone, 200 feet thick. The sandstone contains the oldest 

known fish remains855a and the limestone an invertebrate fauna containing Trenton 

and Richmond fossils. a The Fremont limestone is overlain by Carboniferous limestone, Silurian and Devonian strata being absent, yet, as stated by Crosby, 183 the 

line of demarcation "is not strongly defined, though it represents a long period of 

nondeposition and a great time break." 

J 15. NORTHERN ARKANSAS. 

The Ordovician section of northern Arkansas is very incomplete. There are 

unconformities at several horizons and the formations are irregular in thickness to 

the extent of being entirely lacking in some sections though present elsewhere. 

Ulrich 820 states that the equivalents of the upper Stones River, Black River, Trenton, and Utica are absent. The lower Stones River and the Joachim dolomite of 

Missouri are represented by the Izard limestone, the lower Richmond by the Polk 

Bayou limestone, and the upper Richmond by the Cason shale. Beneath the Izard 

limestone there is in many places a representative of the St. Peter sandstone. 

J 15-16. MISSOURI AND SOUTHERN ILLINOIS. 

The lower Ordovician of Missouri and southern Illinois comprises the later 

formations of the "Magnesian Limestone series" or "Ozark series." The. latest 

published classification is given in Chapter III (p. 104), according to Ulrich. 

The strata placed in middle and later Ordovician comprise the Trenton, Hudson, 

and Cape Girardeau of Keyes's section.491a More recent discussions bearing on the 

correlation of the "Magnesian Limestone series" and the St. Peter sandstone have 

been published by Hall and Sardeson 395 jointly and by Berkey. 71 The strata to 

which Keyes applied the name Trenton are now known as Plattin limestone (at the 

a Ulrich, E. 0., personal note. 
170 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

base) and Kimmswick limestone, and Keyes's Hudson is now called Thebes formation. The formation overlying the Thebes is known as Girardeau limestone. 

According to Ulrich a the Thebes formation includes more than the Maquoketa 

shale, recognized farther north in Missouri and elsewhere. 

Keyes described the three higher Ordovician formations as follows: 

Trenton limestone.-In southeastern Missouri the Trenton limestone as now understood 

embraces, besides the Trenton as comprehended in earlier reports of the State, the Black River 

and Birdseye limestones of Shumard. The latter probably more properly represents the lower 

and less fossiliferous portion of the Trenton of the region and nowhere can be separated 

faunally or lithologically from the upper part containing the typical Trenton fauna. 

The lower Trenton ("Black River" and "Birdseye" limestone) is a compact, heavily 

bedded limerock, often not unlike certain lithographic stones in texture. 

The upper Trenton, or Trenton proper, is well exposed in all the counties along the Mississippi River from Marion to Cape Girardeau. In its northern extension it is chiefly a buff- . 

colored or yellowish-gray limestone with occasional shale partings. Fossils are abundant 

in places, though often in the form of casts. Southward the limestone becomes compact, 

bluish-drab, with abundant fossils. 

Hudson shales.-Everywhere on the eastern border of Missouri, wherever the Trenton 

limestone is exposed, blue calcareous shales are found to overlie it. These shales rapidly disintegrate, upon exposure to the weather, into a soft plastic clay. Numerous thin seams of 

impure limestone are intercalated and often form beds of considerable thickness. Fossils are 

abundant and well preserved. · They are all very characteristic of the fauna occurring at 

Cincinnati, Richmond (Indiana), and in northeastern Iowa. 

Upon lithological and faunal grounds, Swallow and Shumard early correlated these shales 

with the Hudson River shales of New York and Ohio. In 1868 Worthen called these beds 

the "Thebes" shales, from the village of that name in southern Illinois, on the Mississippi River 

below Cape Girardeau. As defined by the Illinois geologist, the Thebes shales and sandstone 

form the lowest member of the Cincinnati group, the upper section embracing practically the 

same beds as the Girardeau limestone of Shumard but placed by the last author in the Upper 

Silurian. In the same region Shumard had previously (though through delays not published 

until several years later) divided those shales intoFeet. 

Upper Hudson shales...................................................................... 45 

Cape Girardeau sandstone..... .. .. .. .. . . .. . .. . . .. . . . . .. . .. . .... . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . 35 

Lower Hudson shales..................................................................... 50 

At Thebes the whole formation is well exposed in a sharp anticline, bringing up centrally 

the Trenton limestone above the water level of the Mississippi River, and successively, on 

either side, all the beds of the Hudson shales. 

North of the Missouri River, in Pike, Ralls, and Marion counties, the lithological characters 

and fossils are essentially the same as in the southern part of the State. 

Girardemt limestone.-This rather well marked division of the lower Silurian in southeastern Missouri was first differentiated by Shumard in 1885 and provisionally called by him 

the Cape Girardeau limestone but was regarded as a member of the Upper instead of the Lower 

Silurian. 

Lithologically the limestone is bluish, very compact, and resembles somewhat the stones 

used in lithographing. It is rather thinly bedded, with numerous vertical fractures or joints. 

Fossils of peculiar types abound. Its thickness is over 60 feet. 

Worthen also recognized this formation as a distinct horizon but made it the upper 

member of the Cincinnati group, the superior part of the Lower Silurian of the region. 

a Personal communication. 
MIDDLE AND UPPER ORDOVICIAN. 171 

Ulrich states that the Upper Hudson shales, the Cape Girardeau sandstone, 

and the Lower Hudson shales of Keyes are now all regarded as of Richmond age. 

From Missouri these Ordovician strata cross the Mississippi into southern 

Illinois, where they have very recently been critically studied by Savage, 703 who 

distinguishes "Galena-Trenton'' light-colored crystalline nonmagnesian limestone, 

68 to 80 feet; "Richmond-Maquoketa," 91 feet, consisting of a lower member of 

sandstone or sandy shale (Thebes sandstone) and an upper one of bluish shale; and 

Alexandrian, consisting of the Cape Girardeau limestone and certain overlying 

beds, 41 feet. Savage proposed the new term "Alexandrian," from Alexander 

County, Ill., to designate a terrane which bridges "the lost interval between the 

Cincinnatian and the Clinton." This terrane, previously distinguished by Ulrich 

in the Mississippi Valley, appears to constitute a transition from Ordovician to 

Silurian. Its correlation with Brazilian strata is discussed by Schuchert. 715 

J 16. INDIANA. 

The strata and faunas of the Cincinnatian series in Indiana have been described 

in great detail by Cumings/ 96 who has reclassified the sequence of limestone and 

shale beds according to formations and faunal zones. The divisions do not possess 

very distinctive lithologic characters, all being limestone, shaly limestone, or shale, 

and they do not maintain a uniform character over any large area, as a rule. The 

following is Cumings's classification, 196a as tabulated by him in ,comparison with 

those that preceded: 
Tabulation of the various classijications of the Cincinnati group. 

Early Orton, Ohio Survey, Winchell and I Nickles, 1902_ I Nickles and Foerste, 

_a_u_th_o_rs_. ____ 1_s_73_. ____ 1 __ u_Ir_ic_h_,_I_s_9_7_._\ __ -1 1905. 

Ulrich, 1906 

(Bassler). Present report. 

\ \:~-~pper. -- \.g~salud~. g. Saluda. 

{ . II iJ Middle. \ S Whitewater. ~ Whitewater. 

,::: Lebanon. Richmond. - fl Liberty. "0 Liberty. 1=1 • 15 i:X1 Lower. i:X1 Waynesville. § Waynesville. 

~ 2 ,.§ 1---------1-----------] "0 c:il;:; ~ 1=1 S c:il Warren. • Arnheim. ~ Arnheim. 

Elkhorn. 

Whitewater. 

] Saluda. 0 Libe!ty. 

] \Vaynesville. 

'"' i:X1 

Arnheim. 

cs ... "'8 c:D 

c:il p..§ Mount Auburn. Mount Auburn. 1---------1-------------

1=\poo 

~2b l=ib()P.. 

~a5;::::! 

~ > 0 

. s~ tn ..s:::: ..... 

Hill Quarry (in 

part) . Lorraine. 

c5 

. s Corryville. "' .... 

.... 

0 

,...::; Bellevue. 

Fairmont. 

~ ·;; Corryville. CL 

>. 

;;;: "' Bellevue. 

McMillan. 

s·~ [;; ~ Middle. 

Fairmont. 

Platystrophia moritura zone. Rhynchotrema dentata zone. Tetradium minus zone. Strophomena planumbona zone. Dalmanella meeki zone. 

Homotrypa bassleri zone ofj·~ ~ Nickles. ;:l "' 

~~ -------- ~'" 

c a zz opora rugosa zone. ~s A::<~ 

-------·---------

Oi=i~ 

'0~§ 

~~·g 

Mount Hope. 

~-----

1-~ {~fi1f~. 

Mount Hope. _____ -P-la_t_y_s_t _r_o_p_h_ia_z_o_n_e_. __ _ 

: c51Upper . 

P

g.. ~,s ~ Fairview. ;;;: Lower. e~ 

----------1 § ---------1 -- 01-'-t.,..., 

~ u Q) 

s 

;.::: I 

I 

1 Eden (in part). Utica. IP Lower. 

' 

.,: {Upper. ~ Middle. 

~~ Lower. 

·f McMicken. ·~~M~ll;:).ken (upQ Southgate. P Southgate (midEconomy. 2; dle). 

Fulton. J Economy (lower). 

I 

I Dekayia ulrichi zone. 

Callopora onealli zone. 
MIDDLE AND UPPER ORDOVICIAN. 173 

J 17-18. MARYLAND, VIRGINIA, AND EAST TENNESSEE. 

The middle and later Ordovician of the Appalachian Valley south of Pennsylvania are represented by the strata which lie between the Knox dolomite below 

and the Clinton ("Rockwood") formation above. In many places, especially along 

the east side of the Appalachian Valley, there is a distinct unconformity between 

these strata and the Knox dolomite. The formations are calcareous, generally 

limestone in the western sections but shaly or sandy in the eastern. They have 

been described by Hayes, 419-426' 428 Campbell, 121 • 123-

125 and Keith 475-

479• 481 as Chickamauga limestone, Athens shale, Tellico sandstone, Sevier shale, Holston marble, and 

Moccasin limestone; by Safford 689 as Lenoir limestone and Nashville or Sevier, 

shale; and by Smith 748 as Chickamauga. Darton 221 a applied the name Shenandoah limestone to the full thickness of limestone occurring between the Lower 

Cambrian quartzite and the Upper Ordovician shales (Martinsburg shale), especially in Virginia. 

Local descriptions follow, in order from southwest to northeast. 

In central eastern Tennessee (Knoxville quadrangle) the sequence and thickness 

of lithologic formations of the Ordovician differ somewhat in the northwestern and 

southeastern areas. Keith 475a gives the two following sections: 

Generalized section northwest of Bays Mountain. 

Period. Formation name. Thickness Character of rocks. (feet). 

~- ----

? Sevier shale. 1,000-1,200 Light-blue sandy and calcareous shales, with beds of limestone and 

-~ argillaceous marble. <.> 

·~ 

0 

'"0 Tellico sandstone. 250-500 Bluish-gray calcareous sandstone. ... 

2. 

~ 

·.: "' Chickamauga limestone. 200--400 Variegated marble, red,- brown, gray, and white. E 500-700 Blue limestones and gray argillaceous limestones. w ~~--- - ---

Cam- Knox dolomite. 3,500 Magnesian limestone, white, gray, light and dark blue, with 

brian. nodules of chert. 

I 

Generalized section southeast of Bays Mountain. 

p 

! Thickness eriod. Formation name. Character of rocks. (feet). ; 

~--

500-600 Light-blue calcareous shale. 

200--400 Bluish-gray and red calcareous sandstones and shales. 

'2 Sevier shale. 500-600 Light-blue calcareous slates. 

"' 500-650 Bluish-gray and gray calcareous sandstones and shales. 

·o 500-750 Light-blue calcareous shale. ·~ 

0 ---~ 

'"0 Tellico sandstone. 800-900 Bluish-gray and gray calcareous sandstones and shales. ... 

2. 

~ I "' Light blue calcareous shale Athens shale. 1•

000- 1 •200 ] Black calcareo~s shale. 

----~~-~---,---------- ---~-----

Chickamauga limestone. 0-50 I Gray argillaceous limestone. 

1--------------1----------1 _____________________________________________ _ 

--C-am----I Knox dolomite. 3 500 j Magnesian limestone; white, gray, light and dark blue, with 

brian. ' nodules of chert. 
174 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

In northeastern Tennessee Keith 481 a distinguishes the following formations: 

Generalized section of the sedimentary rocks in the Great Valley, Greeneville quadrangle. 

System. 

-?-

------.--------~----------

Formation name. 

Sevier shale. 

Tellico sandstone. 

Thickness 

(feet). 

1,300-1,800 

Character of rocks. 

------------- ---

Calcareous sandstones and shales. 

Bluish-gray and yellow calcareous shale and shaly limestone. 

2-200 Red and gray calcareous sandstone. 

---------- --------------------------

1,000±[ Black and bluish-black calcareous shale. 

~--~-~-ccas-ii_-~_li:est::_:._----_-_- -~~0 ~-;;;~,blue, g<a;and dmb ma~ive •nd ahaly lirne.Wnc. 

' Chickamauga limestone. 0-450 I_ -~;:e-and gray li::one, shaly in part, and variegated marble. 

Athens shale. 

-----1------, 

c Knox dolomite. ambrian.__[___ · 

3,000-3,500 

Magnesian limestone, light and dark blue, white, and gray, with 

nodules and layers of chert and a few beds of calcareous sandstone. 

In southern Virginia M. R. Campbell 121a, 125a has mapped the lithologic divisions 

named below: 

Generalized section for portion of Bristol quadrangle north of Clinch Mountain. 

Period. Formation name. Thickness Character of rocks. (feet). 

----

1:1 Sandy shale. 

o; Sevier shale. 1,100-1,300 Blue calcareous shale which generally weathers yellow upon expo- ..... sure. Occasional beds of impure limestone near the base . () 

-~ 

0 

"0 

.... Moccasin limestone. 400-500 Red argillaceous limestone. S2. 

>=I -- ----·-·----

·c "'Chickamauga limestone. 900-1,000 Blue limestone with occasional small lentils of red and gray marble. ~ w 

--- -- Limestone conglomerate with pebbles of chert or beds of red earthy 

Cam- Knox dolomite. 2,300-2,800 

I 

limestone. Gray or white magnesian limestone with nodular 

brian. cherts occurring at intervals throughout the formation. 

The Shenandoah limestone, the comprehensive series of Cambrian and Ordovician limestones of the valley of Virginia, formerly known as the "Valley limestones," 

is briefly described by Darton, 221 who recognized a lower division of dark magnesian 

limestones, grading upward into lighter-colored cherty strata, and followed by purer, 

more thickly bedded, highly fossiliferous limestone. Variations in the character of 

these formations are noted in the reports by W. B. Rogers 676a and J. L. Camp.bell/20 

but the distinctions made have no systematic value. For central Virginia H. D. 

Campbell 119 has introduced the following classification: 
MIDDLE AND UPPER ORDOVICIAN. 175 

Section ofthe Valley limestones near Lexington, Va. 

Ordovician: Feet. 

Liberty Hall limestone ________________________________________ . __________ ... __ .... 1,000± 

Murat limestone. __________________________________________ . ____ . _________________ . 100-150 

Natural Bridge limestone ... _ . ____ . __ . ____ .. _ .... _ . ___ ...... __ .. _ .... _ . _ . _ ..... _ . _ . . 3,500+ 

The correlation of these divisions with those recognized both north and south 

depends on detailed studies, in progress, from which it appears that the limestone 

formations present differences of sequence and facies not previously suspected. 

Bassler 60 states: 

The name Shenandoah limestone proposed by Darton for the Valley limestone of early 

.geologists was made to include all the limestones in the Valley of Virginia occupying the interval 

between the Cambrian quartzites and the Upper Ordovician shales. The lower portion of the 

great limestone series had been found by Mr. Walcott to include Lower, Middle, and Upper 

Cambrian rocks, but the Ordovician portion had been determined only to the extent that Trenton strata were supposed to occur at the top. The work of the writer in Virginia brought out 

the fact that the geologic succession of the Ordovician division was quite different in various 

parts of the valley. In northwestern Virginia a great thickness of Beekmantown is overlain by 

1,000 feet of Stones River, and this in turn by 400 feet of Black River, while the strata bearing 

Trenton fossils form the lowest division of the overlying shales. In central western Virginia the 

Black River alone rests upon the Beekmantown, but in southwestern Virginia two distinct 

arrangements were noted. Along the western edge of the valley the Beekmantown is followed 

by 1,000 or more feet of Stones River but no Black River, while along the eastern side only the 

Black River occupies the interval between the overlying shales and the Beekmantown. In 

each case the Trenton does not form the upper part of the limestone, but is the basal member 

of the overlying shales. 

The Shenandoah limestone, therefore, is a broad term, embracing strata of Cambrian and 

Ordovician age, the geologic succession of the latter varying in different parts of even the type 

area. 

The classification of the Ordovician limestones of southern Pennsylvania as 

worked out by Stose and Ulrich is given in Chapter III (pp. 107-111). There is no 

reason to look for any marked difference in the section where the belt crosses 

Maryland, but the divisions have not been traced. 

X: 10. TAYLORSVILLE DISTRICT, CALIFORNIA. 

The Grizzly formation, which occupies the summit of Grizzly Peak, in the Lassen 

Peak quadrangle, California, is an unfossiliferous formation, 400 feet thick, which 

underlies the Montgomery limestone. As the latter is considered by Walcott 271b: 272 

to be of Niagara age, it is possible that the Grizzly formation is of Ordovician age. 

K 12. WASATCH AND UINTA RANGES, UTAH. 

The quartzite of the Wasatch and Uinta ranges, distinguished by the Fortieth 

Parallel Survey as Ogden quartzite and mapped as Devonian, is correlated by Weeks 873 

and Ulrich as Ordovician. In the Wasatch section it rests upon limestone of Cambrian and Ordovician age, is 800 to 1,200 feet thick, and is overlain by Silurian 

limestone, at least in Cache Valley. Along the south side of the Uinta Range it lies 

upon the Lodore shale (Cambrian) and is immediately followed by limestone of lower 

Mississippian age. No equivalent is known on the north side of the Uinta Range. 
176 INDEX TO THE STRATIGRAPHY OF NOR'fH AMERICA. 

Blackwelder 840 showed that the quartzite in Ogden Canyon is a Cambrian 

quartzite which owes its apparent stratigraphic position to an overthrust. There is 

therefore no Ordovician quartzite in Ogden Canyon and the name is inappropriate. 

But an Ordovician quartzite does occur in Cache Valley and also south of Ogden. 

In green shales at the base of this quartzite have been found abundant fossils, 

which, on preliminary examination, E. 0. Ulrich 84d pronounces to be of the age 

of the Beekmantown fauna of the Eastern States. 

K 13. BLACK HILLS. 

In the northern Black Hills occurs a formation similar to the massive Bighorn 

dolomite, known as the Whitewood limestone, which is of Trenton age. It is 

80 feet thick near Deadwood, but thins out toward the south. 241a• 471 

In the Front ranges of Colorado north of Colorado Springs the Ordovician, 

like other pre-Carboniferous Paleozoic systems, is lacking. 

K 16. SOUTHEASTERN WISCONSIN ,AND NORTHEASTERN ILLINOIS. 

The St. Peter sandstone, Trenton limestone (as defined by the Wisconsin 

Geological and Natural History Survey), Galena dolomite, and "Cincinnati" 

shale constitute the Ordovician of Wisconsin and northeastern Illinois above the 

"Lower Magnesian" ("Calciferous") limestone. The St. Peter 71 is a friable 

white or yellow sandstone, which varies in thickness from a thin edge to 212 feet 

and lies unconformably on the "Lower Magnesian." The overlying Trenton is 

in part a simple, in part a magnesian limestone with clayey partings, about 115 

feet thick, in which several distinct subdivisions are recognized. Next higher is 

the Galena, a coarse-grained thick-bedded dolomite, about 250 feet thick, which 

becomes more argillaceous toward the northeast and northwest. The highest 

formation of the Ordovician section is the "Cincinnati" shale, bluish or greenish, 

with intercalated limestones, which reaches a thickness of 200 feet or more. 1330 

A period of nondeposition and erosion followed in Wisconsin and .elsewhere in the 

central western United States 885 covering late Ordovician time. This period of 

nondeposition corresponds to the interval between the "Cincinnati" shale and 

the Galena dolomite. The so-called "Cincinnati" shale is of Richmond age. In 

southwestern Wisconsin and northwestern Illinois the Ordovician shale outcrops 

and is there known as Maquoketa shale. 

The formations in northern Illinois constitute the southward extension of 

those described by Chamberlin for Wisconsin. Bain 51 has recently described the 

limestones and associated strata of northwesterrr Illinois. Above the earlier 

Ordovician rocks he recognizes the St. Peter sandstone, Platteville ("Trenton") 

limestone, Galena limestone, and Maquoketa shale. 

K 17-18. PENNSYLVANIA AND NEW JERSEY. 

The limestones of southeastern Pennsylvania have been described by Stose. 801 

The quotations regarding the Cambrian and early Ordovician formations given in 

Chapter III (pp. 107-113) are here continued for the later Ordovician. 

The Stones River limestone is composed in general of three divisions-a middle 

band of massive pure granular limestone containing the large gastropod JJfaclurea 
MIDDLE AND UPPER ORDOVICIAN. 177 

magna and thin beds of black chert that weather into small rectangular blocks; 

an upper series of thin-bedded pure limestone; and a lower series of interbedded 

massive pure beds and magnesian layers. From the middle division 22 species 

of fossils have been obtained, among which there are eight which occur in the 

middle Chazy of the Champlain Valley. As a whole, the fossils as well as the 

lithologic character of the formation are practically the same as those of the Stones 

River group of Tennessee. 

The Chambersburg limestone is the uppermost division of the Shenandoah limestone. 

It is characterized throughout the area by fossiliferous thin-bedded limestones with argillaceous 

partings. It varies in thickness across the strike from a maximum of 600 feet in the Chambersburg belt to about 100 feet in the McConnellsburg Cove. 

Its most typical development is in the Chambersburg belt, throughout which fossils are 

abundant. The following section in the railroad cut 1! miles west of Kauffman is the most 

complete continuous section in this helt: 

Black shale (Martinsburg). 

Largely concealed, but probably chiefly shale (near the top are black carbonaceous limestone with 

conchoidal fracture, shaly dark crystalline limestone, thin sandstone, and 10 feet of coarse crystalline limestone containing Ungulas) ..... _ ...... __ . _ . _ . __________ .... ___ . _ . _ . _ . _ ... _ _ _ _ _ 150 

Calcareous shale and limestone ............................. _. ___ .. ___ .... _._._. ___ . _________ 100 

Nodular clayey limestone ..... _ ................................................. _._ ... _._._ 50 

Dark platy limestone_ ......... _._._ .... --- .... _._ .. _ ....... _. _ ...... _ ........... _. ______ . _.. 94 

Compact dark limestone, very fossiliferous .. -...................... _ ............. _ . _ . _ . _ . _ . _ 108 

Cobbly limestone containing numerous nidulites, Bryozoa, and a layer of cystidheads. ______ . _. ___ 105 

607 

The "cobbly" character of the weathered outcrop of certain of the beds,· due to a wavy 

lamination or clay parting that crosses the bedding at a high angle and, on weathering, gives 

rise to rounded lenticular masses resembling rough cobbles, is one of the noticeable features of 

this formation. The upper 200 feet of the formation is composed largely of shale with interbedded thin fossiliferous limestones. 

* * * * * * * * * 

Nearly everywhere this formation yields on careful search an abundance and great variety 

of fossils, and those from the Chambersburg quadrangle differ from those obtained in the Mercersburg quadrangle. In the Chambersburg belt the formation may be divided into four faunal 

zones. 

* * * * * * * * * 

In the Mercersburg quadrangle four faunal zones are also distinguished, but they do not 

correspond with those of the Chambersburg belt. 

In southeastern Pennsylvania and Maryland the Ordovician strata are overthrust by pre-Cambrian schist and metamorphosed to phyllite and schist. The 

complex relations have been worked out by Bascom 57• 58 and Mathews,579 who 

distinguish the established divisions of the section in adjacent fossiliferous districts. 

The Cambrian and Lower Ordovician formations of the Philadelphia district 

(Chickies quartzite and Shenandoah limestone) are described in Chapter III (pp. 

111-113). Bascom 58b continues the description of the Ordovician formations as 

follows: 

Further sedimentation in Ordovician time is represented by the Octoraro. This is the last 

known Paleozoic deposit in this region and, like the preceding Paleozoic sediments, is dynamically metamorphosed and free from igneous intrusions. 

The Octoraro schist is largely confined to the South Valley Hills, pinching out to the northeast and expanding to the southwest. Outliers of the mica schist occur north of Berwyn and of 

48011°-12-12 . 
178 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Paoli and on Henderson and Bridgeport hills. The Henderson and Bridgeport outliers, while 

lithologically similar to the main mass of mica schist, can not be positively correlated with the 

formation. Their relation to limestone of Chazy age, as seen in the Schuylkill River cut, is such 

as to admit interpretation either as an interbedded structure or as the overlying synclinal 

structure which the Octoraro schist must possess. 

The mica schist is characterized by a pronounced lamination of a slaty rather than a schistose type. The laminre exhibit lustrous silvery surfaces and a blue-gray or green-gray color, 

which under the action of weathering alters to reddish yellow. 

The chief constituents of this mica schist are quartz, muscovite, orthoclase, and chlorite. 

Quartz occurs in interlocking grains which show undulatory extinction and other pressure effects . 

in their form and arrangement. Orthoclase occurs sporadically in considerable areas, but it is 

not an important or characteristic constituent. Chlorite is uniformly distributed through the 

rock, interspersed with wavy lamellre of muscovite. Plagioclase, biotite, magnetite, ilmenite, 

tourmaline, apatite, and pyrite are accessory constituents. 

The constituents of the schist do not possess clearly defined outlines and the crystalline 

texture is neither so coarse nor so sharply defined as in the Wissahickon gneiss. 

In the hand specimen quartz is completely overlain by minute plates of mica, which alone 

show on the cleavage surface, while eyelets of quartz may show on the edges of the laminre. 

Cubes of pyrite more or less altered to limonite are characteristic. Considerable oxide of iron 

is present in this formation, which is evidently the source of the limonite ore that occurs sporadically in pockets between the limestone and the schist. 

The a~alyses of the mica schist, with the relatively high alumina and low silica and absence 

of lime, fairly indicate a sedimentary origin for the formation. 

* * * * * * * * * 

The lower beds of this formation are more calcareous, more siliceous, finer, and darker 

colored than the upper beds. The outlying areas at Bridgeport and Henderson are of this 

character. In some places there appears interbedded with the mica schist a quartz schist or a 

quartzite similar to the Cambrian quartzite. Fragments of such a quartz schist show 1 mile 

north of Paoli on the northwestern boundary of the mica schist, and 2 miles north of Wayne 

such a siliceous member furnishes sand for local use. ' 

The mica schist of the South Valley Hills appears to overlie the Shenandoah limestone 

without faulting or unconformity. This is indicated by the lithologic gradation between the 

limestone and schist which may be seen at the northwest base of the South Valley Hills and by 

the persistence of the same geodiferous quartzose beds along the contact of the two formations 

and is confirmed by the fact that the outcrops show that deformation was by folding and flowage 

and not by faulting. 

The structure of the hills is evidently synClinal, though cleavage and fissility are so pronounced as to obscure the stratification. On the limbs ()f the syncline cleavage and bedding are 

approximately parallel, while cross structures prevail in the trough of the syncline. 

* * * * * * * * 

The structure of the formation in the South Valley Hills indicates a thickness probably not 

exceeding 1,000 feet. It is not known, however, whether the full thickness of the formation is 

present here. 

* * * * * * * * * 

The formation is held to be Ordovician in age on the ground of its normal stratigraphic 

position on the Cambro-Ordovician limestone. It is correlated with the BPrkshire schist of the 

New England section, the Hudson schist of New York, and doubtfully with the phyllites of 

:Maryland. It is the Primal upper slate of the First Geological Survey of Pennsylvania, and the 

Cambrian phyllite of the Second Geological Survey. 

Ranging southwestward from Orange County, N. Y., the Cambrian and Ordovician strata pass into New Jersey with the facies described as the Hardyston 
MIDDLE AND UPPER ORDOVICIAN. 179 

quartzite, the Kittatinny limestone, the Jacksonburg limestone, and the Martinsburg shale. The formations have been described by Kfunmel, 512•

513a from whose 

recent account the following notes on the Ordovician are taken. The description 

of the Cambrian formations has been given in Chapter III (p. 113). 

In northern New Jersey, as elsewhere in the great Appalachian Valley, there is no sharp 

line of demarcation between the rocks of the Cambrian and those of the Ordovician system. 

The base of the Ordovician lies somewhere below the top of the Kittatinny limestone, as stated 

above, but the exact position of this division line can not readily be determined. 

Above the Kittatinny limestone, and separated from it by a break in sedimentation indicated by a calcareous basal conglomerate, is a dark-blue or black fossiliferous limestone, correlated with the Lowville, Black River, and lower Trenton limestone of the New York section and 

hitherto classed as "Trenton," some layers of which contain as much as 95 per cent or more of 

calcium carbonate. Calcareous shales occur interbedded with these limestones and above them 

to the top of the formation. The sequence of conglomerate, limestone, and shale is a variable 

one, but, so far as observed, the transition to the overlying formation is always through a series 

of calcareous shales which become less and less limy. 

The thickness of the Jacksonburg formation varies from 135 to 300 feet or more. It contains an abundant fauna, 98 forms having been described by Weller. At the type locality the 

lower strata for a thickness of 58 feet carry a Lowville-Black River fauna, and the higher beds 

have a lower Trenton fauna. 

The Jacksonburg limestone passes upward through the calcareous shales mentioned above 

into a great thickness of shale, slate, and sandstone, which has heretofore been known as the 

"Hudson River slate" but which is now correlated with the Martinsburg shale of West Virginia 

and takes that name. 

The formation ranges from the finest-grained shale and slate to fine sandstone. The former 

beds on the whole are black and more abundant in the lower part, whereas the sandstone beds 

are dark bluish gray, many of them calcareous, and occur more commonly higher in the formation. The fine-grained rocks exceed the gritty beds. 

* * * The whole formation is so crumpled and cleaved that no accurate estimate of its 

thickness can be made, but it is probably at least 3,000 feet, and it may be more. 

Four species of graptolites of the Normanskill fauna of New York have been found in the 

lower portion of the Martinsburg shale, so that the beds in which they occur are equivalent in 

age to the middle portion of tho typical ';~'renton lime~ tone ?f central New York. A few miles 

north of the New Jersey State line Schizocrania and graptolites characteristic of the Utica shale 

of the Mohawk Valley have been found in beds close to tho overlying Shawangunk conglomerate. 

Detailed descriptions of the fauna are given by Weller.769•

878•

880 

K-L 12-13. WYOMING AND NORTHERN COLORADO. 

The Ordovician of this region is a relatively thin deposit of limestone, attaining 

a maximum thickness of 300 feet, lacking in many sections, and locally underlain 

by a sandstone which carries remains of fish. 855 Darton 241'

244 has recently summed 

up the known facts in a comprehensive manner. 

In the Bighorn Mountains the Ordovician strata constitute the Bighorn dolomite, which in the north averages about 300 feet in thickness, including a basal 

white sandstone, a massive magnesian limestone, and about ~00 feet of softer 

thinner-bedded limestone at the top. The strata range in age. from Black River 

at the base to late Richmond at the top and are said to be divided by a hiatus 

equivalent to later Trenton, Utica, Eden, and Lorraine, of which, however, the 

evidence is mainly paleontologic. 
180 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

In the Owl Creek and Wind River mountains of central and western Wyoming 

the Bighorn dolomite occurs with much of the character which it has in the type 

locality of the northern part of the Bighorn Range. 

K-L 15. MINNESOTA, NORTHEASTERN IOWA, SOUTHWESTERN WISCONSIN, AND NORTHWESTERN ILLINOIS. 

The Ordovician exposed on both sides of Mississippi River comprises the following formations, in descending order: 

Maquoketa shale. 

Galena dolomite. 

Decorah shale ("Green shales" of Minnesota reports). 

Platteville limestone. 

St. Peter sandstone. 

Prairie du Chien group (of Beekmantown or Lower Ordovician age): 

Shakopee dolomite. · 

New Richmond sandstone. 

Oneota dolomite. 

The Prairie du Chien group is discussed in Chapter III (pp. 119-120). The 

classification of the Ordovician into the formations enumerated above is based on the 

work of Calvin 118 and of Grant, Burchard, and Ulrich. 386 In the folio by the three 

authors last cited the middle and upper Ordovician rocks are described in detail 

and lists of fossils are given. The following is an abstract of their description: 

Unconformably upon the Prairie du Chien formation lies a comparatively thin sandstone 

long known as the St. Peter from the fact that it occurs along the lower course of St. Peters 

(now known as Minnesota) River. The thickness of this sandstone varies considerably, averaging in this district perhaps 70 feet but ranging from 35 to 17 5 feet. * * * The variation 

in the thickness of the St. Peter sandstone is due, at least in the main, to irregularities in the 

surface of the underlying formation-the Prairie du Chien-which suffered considerable erosion 

before the sandstone was deposited. The top of the sandstone likewise may have been somewhat 

eroded prior to .the deposition of the succeeding Platteville limestone, although this is not 

evident from discordance of stratification. 

* * * Nearly everywhere at the base of the formation there is a foot or two of bluishgreen sandy clay shale. Above this basal shale the St. Peter is practically pure quartz sandstone, the percentage of silica in its composition being very high and at some places exceeding 

99 per cent. * * * 

The grains are well waterworn and of medium fineness, the greater part passing a sieve 

having 40 meshes to 1 inch. 

* * * * * * * * * The transition from the St. Peter sandstone to the overlying :rlatteville limestone is marked 

by a bed of blue sandy shale which ranges in thickness from a few inches to 5 feet or more. 

This shale is not commonly sharply separated from the sandstone, but grades into it. On the 

other hand, the upper edge· of the shale is sharply delimited by the overlying massive beds of 

the lower part of the limestone. The sand grains in the shale do not usually extend to its upper 

surface, and very rarely are these grains found in the lower. beds of the Platteville. * * * 

The St. Peter can be regarded as a practically nonfossiliferous formation, though a few 

casts, mainly of pelecypods or bivalve shells, have been reported from it. This scarcity of 

fossils seems to be due as much to the fact that in so porous a rock solution would destroy 

calcareous shells as to the fact that few animal remains were entombed in it originally. The 

St. Peter is a wide-reaching formation in the upper Mississippi Valley, and in the Ozark region 

it is represented by the sandstone which immediately underlies the Joachim limestone and 

which has frequently been termed the "First Saccharoidal" sandstone. 
MIDDLE AND UPPER ORDOVICIAN. 181 

The Platteville limestone is noticeably different from the other calcareous members of the 

Paleozoic section in these quadrangles in that it is largely a pure limestone, or a magnesian 

limestone, rather than a dolomite. In earlier reports on this district this formation was called 

the Trenton limestone, but the name Platteville has recently been applied to it, as it is possible 

that these beds do not represent the exact equivalent of the Trenton in its type locality. * * * 

The Platteville averages 55 feet in thickness and maintains this average over a considerable 

part of the area. 

Generalized section of Platteville limestone. 

Feet. 

4. Limestone, principally in thin beds, and shale .......................... _ .............. 10-15 

3. Thin-bedded brittle fine-grained limestone ...... _. . .. _ ... __ ...... _. _ .. _. . . . . _. . . . . . . . 1.5-25 

2. Thick-bedded magnesian limestone or dolomite .................................. _ ...... 15-25 

1. Blue shale, at some places sandy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1- 5 

* * * * * * * * * It is at some places difficult to draw the boundary between the Platteville and the Galena 

on purely lithologic criteria. The contact, however, is probably unconformable, despite its 

obscurity and the fact that it apparently occurs in the midst of a shaly unit. A close study of 

the fossils rarely fails to locate the contact within very narrow bounds, and then the actual 

physical break between the two formations may in places be determined. At many places the 

first few inches of the Galena consist of a shale or clay containing more or less clear evidence 

that it is a deposit which has been reworked by water. At some places it contains fragments 

of fossils, more perfect forms of which occur in the bed just below. At some localities this 

lowest bed of the Galena consists of a yellow to white clay, called "pipe clay," underlain by an 

inch or two of dark carbonaceous clay. 

* * * * * * * * * 

The Platteville is commonly highly fossiliferous, more so than any other formation within 

the area except possibly the Maquoketa shale. Although practically all the beds of the formation except the basal shale contain fossils in greater or less abundance, certain beds are literally 

packed with organic remains: The dolomitic second member contains relatively few fossil 

remains, and at some places this bed may appear almost barren. A few species range through 

nearly all the beds, notably Leperditia fabulites Conrad, which is the most characteristic fossil 

of the formation. Many other species, however, being more restricted in range, may occur in 

only one or two of the beds. 

* * * * * * * * * 

The Platteville is regarded as the equivalent of tho Stones River group of Tennessee and 

Kentucky, a group that lies lower than the Black River and Lowville (Birdseye) limestones of 

New York. 

* * * * * * * * * * 

Lithologically the Galena is a dolomite-a granular, crystalline, coarse-grained porous 

rock, which weathers into exceedingly rough, pitted, and irregular forms. * * * The 

formation exhibits the same lithologic character everywhere except in its extreme upper and 

lower parts. As a whole it is massive in appearance; the average thickness of the beds is from 

1 to 4 feet. Near the bottom and near the top, however, thinner beds occur. Chert nodules 

are common in the middle part. At many places very thin seams or partings of clayey material, 

a little darker in color than the main mass of the dolomite, separate the formation into irregular 

layers. * * * 

The thickness of the formation within this area averages about 235 feet. 

The upper portion of the Galena is thin bedded, earthy, and noncrystalline. 

Shale occurs as partings, and in the uppermost strata, where the Galena passes into 

the Maquoketa, it forms the rock and the limestone becomes nodular. Near the 

bottom of the Galena occurs a so-called oil rock, a finely laminated brown to black 
182 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

shale, which is made up largely of microscopic unicellular algre and which contains 

as much as_ 20 per cent of heavy oil. 

Some beds of the Galena contain abundant organic remains, but the main body of the 

dolomite carries few recognizable fossils. Locally, however, where the basal limestone and 

shale were deposited, as shown in the first two sections of the Platteville limestone given in the 

description of that formation, they are highly fossiliferous. 

* * * * * * * * * 

The Galena and Platteville form a thick dolomite-limestone series, which is of much importance in the upper Mississippi Valley. The lithologic features of the two formations here 

described are those which are common to the lead and zinc district. Outside of this district 

the characteristics vary somewhat, and toward the west the Galena becomes les<:J dolomitized, 

especially in its lower part. 

In the lead and zinc district the Platteville, commonly known as "Trenton" in the reports 

on this district, is essentially a nondolomitic formation, while the Galena is a dolomite. If this 

lithologic distinction should be usecl as a means of separating these formations in areas lying 

farther west the thickness of the Platteville would be there greatly increased. Recent work, 

however, has shown that the Platteville is a well-defined formation of comparatively uniform 

thickness, possessing distinctive faunal charac_teristics; that, at least locally, it is separated 

from the Galena by a period of nondeposition; and that in certain localities, espeoially at places 

west of the Mississippi, the Galena is in considerable part nondolomitic. 

* * * * * * * * * 

Upon the Galena dolomite lies a shale formation, which has been described in reports of the 

Iowa Geological Survey under the term Maquoketa, a name derived from Little Maquoketa 

River, on which it is typically exposed. The same formation is known in the Wisconsin State 

reports as the Cincinnati shale. * * * 

The shale ranges in thickness from 160 to 200 feet and in the region south of this area is 

·more than 200 feet thick. 

* * * * * * * * * 

The Maquoketa shale m this area can be arranged roughly into the three characteristic 

divisions described below: 

General divisions of Maquoketa shale. 

Feet. 

:3. Argillaceous and calcareous shale, in beds becoming thicker and possibly dolomitic toward 

the top, about .................................... -..... -.-----.---.- ...... -.--.-..... 35 

2. Plastic blue and green shale and clay, with some indurated fos~iliferous bands near the top, 

about. .................................................. -... -..... -. . . . . . . . . . . . . . . . . 100 

1. Drab and blue thin fissile shale, interbedded with thin layers of fossiliferous argillaceous 

limestone; near base is a thin, hard conglomerate .of fine chert and phosphatic pebbles in a 

ferruginous matrix.................................................................... 60 

* * * * * * * * * 

The Maquoketa shale in general throughout the upper Mississippi Valley forms a markedly 

fossiliferous horizon. There is at the very base of the formation a thickness of 2 to 5 feet of 

8 hale which contains rather abundant fossils. * * * At the top of the formation there is 

another horizon, more frequently exposed, that affords fossils, at some places in great abundance. * * * This association of species indicates that the beds are of Richmond age. 

* * * Definite evidences of stratigraphic unconformity or of an erosion interval at the 

base of the Maquoketa have not been observed during the survey of this area. The change 

from the dolomite beds of the Galena to the shale is fairly abrupt, and mention has been made 

of a small conglomerate that occurs locally in the basal shale, but the sedimentation planes on 

the two sides of the contact line are parallel, as far as seen. The evidence, so far as it goes, does 

not indicate any marked physical break between the formations, although the fossils_ would 

indicate a period of nondeposition. 
MIDDLE AND UPPER ORDOVICIAN. 183 

Upon the Maquoketa lies a heavy magnesian limestone of the Niagara, whose basal layers 

apparently rest concordantly on the magnesian upper Maquoketa beds where these are present. 

Here the lithologic change is less abrupt than at the bottom of the formation; nevertheless, the 

evidence furnished by fossils indicates a hiatus. There is also some evidence that the topmost 

fossiliferous Maquoketa beds are not everywhere present, this fact suggesting that erosion has 

actually occurred. 

The Ordovician formations which traverse northeastern Iowa range northward 

into Minnesota in the apparent embayment of the sea which lies between the Isle 

·wisconsin 133b on the east and the Peninsula of Minnesota, which terminates in the 

Sioux quartzite area, on the west. The strata have been made the object of an 

elaborate correlative study by Ulrich.944 

K-L 17-18. ONTARIO AND NEW YORK. 

North of Lake Ontario is a wide belt of Ordovician strata which extends southeastward around the Adirondack crystalline rocks into the Mohawk and Hudson 

valleys, New York. In Ontario the section as described by Ami 2aa comprises limestones and shales from the Potsdam to the Lorraine inclusive. The sandstones are 

local basal shallow-water deposits resting unconformably on the pre-Cambrian. 

The distribution and character of these strata from Kingston,· on the St. Lawrence, to Georgian Bay are described by Logan 544ct with detailed local sections and 

lists of fossils. His general statement runs as follows: 

From the province line, where it crosses Lake Champlain in eastern Canada, the Birdseye, 

Black River, and Trenton formations, striking through the valley of this lake and the valleys 

of the Mohawk and Black rivers, reach the waters of the St. Lawrence and cross over into western 

Canada. On the United States side of the St. Lawrence they occupy a breadth extending from 

the Thousand Islands to Sandy Creek, and on the Canadian side from the neighborhood of 

Kingston to the outside of the Prince Edward peninsula. 

It ha.S already been stated that between the Potsdam formation and the strata characterized by the fossils of the Birdseye and Black River formations, to the westward of the Laurentian 

ridge of the Thousand Islands, there are about 80 feet of strata the age of which is not very 

clear. These appear in two succeeding escarpments and are traceable for a considerable distance. 

Logan then gives a minutely divided section of strata outcropping at Vanluvin's 

mills, Storrington, which are assigned to the Chazy by Ami. Around Kingston 

these basal beds are Pamelia, but near Georgian Bay they are Lowville. In 

either case they are lithologically nearly the same. 

Logan's descriptions of the Black River and Trenton limestones are characterized by that degree of detail which marks his work and makes it a standard of 

reference that can not be adequately summarized. 

In New York the Ordovician strata range south of the Adirondack area through 

Jefferson, Lewis, Oneida, Herkimer, Montgomery, Schenectady, and Saratoga 

counties to the Hudson. North of the Adirondacks they extend through St. Lawrence, Franklin, and Clinton counties to Lake Champlain. Their distribution as 

shown on the map of North America is taken from the New York State map of 1901.592 

The district west, south, and east of the Adirondacks includes the local sections 

that were established as the standard New York section, which became the basis of 

North American correlation. · 
184 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Dana 220 distinguished "Calciferous epoch, Chazy epoch, Trenton epoch, Utica 

and Hudson epochs" and described the strata which characterize each epoch in 

this and other districts. The New York State Survey publishes the following 

classification, 155 which shows also the distribution of the several divisions and 

brings out the fact that they are not uniform throughout the State. 

Extent of unit formations along their strike from west to east in the State of New York. [a] 

[A star(*) signifies that the unit is absent from the outcrops in the region represented by the column in which it stands.l 

System. Central. I East central. Eastern. 

Lorraine shale. j Lorraine (Frankfort) shale. Lorraine (Frankfort) shale. 

Pulaski shale. 

Frankfort shale.[bl 

Salmon River shale. 

Utica shale. Utica shale. Utica shale. 

{Trenton limestone. 

Champlainic or Trenton limestone. Trenton limestone. Normans Kill shale. 

Lower Siluric. Rysedorph conglomerate. 

Black River limestone. Black River limestone. Black R1ver limestone. 

Lowville limestone. Lowville limestone. (*) 

(*) (*) Chazy limestone. 

Deepkill shale. 

Beekmantown limestone. 

Wappinger limestone. 

- a Revised in accordance with letters from John M. Clarke, Jan. 13 and 19, 1910.-B. W. 

b The Frankfort begins well down in the Trenton and extends upward to some undetermined age. Possibly it 

corresponds to the Martinsburg shale.-E. 0. Ulrich, comment on manuscript. 

Grabau 383 published a discussion of the Ordovician in 1909 and suggested a 

revised classification. 

It appears from the investigations of recent years that the Ordovician limestones west and south of the Adirondacks, like those of the upper St. Lawrence 

Valley, differ from the formations of corresponding age that occur east of the Hudson-Champlain trough. The western strata were spread over the margin of the 

continent in embayments that extended north and south of the Adirondack island 

or peninsula. They are neither uniform in distribution nor continuous in sequence. 

Cushing 204a has recently worked in Lewis and Jefferson counties west of the 

Adirondacks, in the original locality of the Lowville (or "Birdseye"), Black River, 

and Trenton limestones, to which Logan refers as quoted above (p. 183). He there 

determined the following section: 

7. Trenton limestone: Thin-bedded black, somewhat shaly limestones, with lenses of gray 

crystalline limestone. 

Feet. 

6. Black River limestone: Massi~e black limestone, lower portion full of black chert nodules .. 15-20 

5. Lowville limestone: Blue or dove-colored fine-grained limestone, with beds of thin shaly 

limestones, which constitute nearly one-third of the formation ....................... 75-85 

4. Pamelia limestone: Blue and dove limestone, with intercalated magnesian limestones and, 

in the upper half of the formation, much whitish impure limestone and some yellow 

water lime. A thin basal sandstone and overlying shales ............................ 40-130 

[Unconformity.] 

3. Theresa formation: Somewhat calcareous, sandy dolomites, weathering to rotten stone, with 

interbedded weak sandstones, especially near the base. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-60 

2. Potsdam sandstone: White, yellow, and red quartzose sandstone, brown spotted and weakly 

cemented toward the summit...................................................... 0-80 

1. Pre-Cambrian. 
MIDDLE AND UPPER ORDOVICIAR 185 

Referring to Chapter III (p. 123) for the description of the Potsdam and "Theresa" formations, we may quote Cushing 2040 on the Pamelia and Lowville of the 

vVatertown district (west of the Adirondacks) as follows: 

The Pamelia limestone is the most interesting formation in the section, since it represents 

the thinned edge of a formation which, while widespread elsewhere, has not heretofore been 

recognized in New York and is probably in existence in the State as a surface formation only 

in this immediate district. Because of its wide separation from other areas where the formation 

appears and because it represents only a small portion of the entire formation, the giving of a 

local name seems justified, and in Pamelia Township the entire thickness and both contacts 

are exposed. 

The formation consists essentially of limestone, though the bulk of it is not pure limestone. 

At its base is found a thickness of from 10 to 20 feet of sandstone and greenish shale, the sandstone being coarse but weak, owing to calcareous cement, and somewhat pebbly at the base, 

while the overlying green shales are both sandy and calcareous. * * * 

The formation has a thickness of from 125 to 150 feet along the western margin of the 

Theresa quadrangle and somewhat less than half that thickness on the eastern border. * * * 

Above the sandy base the lower portion of the formation, 50 to 60 feet in thickness, is composed 

of alternating beds of blue-black limestone, dove limestone, and gray magnesian limestone. 

The beds usually run from 1 to 3 feet in thickness, though the black limestones may reach a / 

thickness· of 10 to 15 feet. The upper half of the formation lacks the black limestone and 

consists of alternations of dove limestone, gray magnesian limestone, light-gray to white thinbedded impure limestone, and yellow water lime. About midway of this upper half is a horizon 

where the rocks have a pronounced pink tinge through a thickness of from 10 to 20 feet. Outside of the dove limestone beds, most of the material of this upper division is thin bedded, and 

the abundance of light-colored layers sharply distinguishes it from the lower division. Near 

the summit certain layers contain abundant nodules of coarsely crystalline calcite and sometimes 

celestite as. well. At the extreme summit are 10 to 15 feet of more massive beds of gray limestone overlain by a thickness of a few feet of white impure beds which are somewhat sandy, and 

these uppermost white beds are regarded as forming the base of the overlying Lowville formation. From base to summit the formation carries an abundant ostracod fauna. In addition, 

the black limestones of the lower division carry a considerable additional fauna of gastropods, 

cephalopods, corals, and trilobites. There is some evidence that, as the formation thins to 

the east, owing to overlap, these black fossiliferous limestones occur at. higher and higher 

horizons, in fashion similar to the rise of the basal sandstone in the same direction. 

Many of the beds of dove limestone have mud-cracked surfaces. In connection with the 

ostracod fauna and the presence of water limes, this seems to indicate shallow-water and closedbasin conditions, similar to those which characterized the deposition of the water lime of the 

Upper Silurian in the State; but the fossiliferous limestones of the lower portion of the formation indicate that a period of open water, permitting the incoming of a marine fauna, preceded 

the closed basin conditions. 

* * * [The Lowville] is a quite pure limestone formation, with a thickness of some 75 

feet. The upper 20 feet are of pure limestone of blue or dove color and are exceedingly fossiliferous. Beneath follow 10 to 15 feet of thinner, more shaly limestones, with occasional fossils, 

after which through 30 feet thickness appear alternations of these thin layers with thicker beds 

of blue or dove limestone, with a basement of 10 feet of massive blue limestone, and then the 

white shaly beds already noted as forming the base of the formation. * * * The lower part 

of the Lowville formation carries mainly an ostracod fauna, other forms being scarce, though 

they do appear. "But the lower Lowville Ostracoda include species of Leperditia and Isochilina 

of much larger size than any so far observed in the underlying Pamelia." a 

This local section is placed by Cushing 204d in comparison with those of the 

Mohawk and Champlain valleys. 

a E. 0. Ulrich, letter of March 25, 1908. 
186 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Comparison with the Champlain and Mohawk sections. 

---.. ~----.. ---~~-- --· --·---------- . 

___ Ch•:"Joi,'_VWloy~- I Mol.,wkV,Uey 

Black River and Lowville, 40 to 60 feet. {~;~~N~~grtoO 2t /e~f~et. 

-·-·-·--- --··-- ~--------· 

/

Upper, 200 feet. 

Chazy·· Middle, 350 feet. 

Lower, 340 feet. 

Absent. 

i Absent. 

Absent. 

Watertown district. 

I Black River, 20 feet. 

__I Lowville, 60 to 75~~ -~-

) 

Absent. . Pamelia, 40 to 140 feet. 

Absent. 

Absent. 

-----------------· ---·----··-~--

!

Division E, 470 feet. ) 

Beekmantown .. D~v~s~on D, 375 feet. <\.b . DivlBwn C, 350 feet. • sent. 

Division B, 295 feet. 

I I Absent. 

I 

~--~-~-~~-~---- ~-- ~~--~~~-1 Unconformity------·- ··~~---

Beekmantown, A, 310 feet. 

Passage beds, 30 to 75 feet. }Little Falls dolomite, 500 (?)feet. I Theresa, 20 to 60 feet. 

1----~------ I ~~~------ ----

- ---~~bse-nt_. __ ----'-~--~---~-Potsdam. Potsdam. 

Cushing 204e concludes: 

It has been shown that four formations~the Lowville, Pamelia, Theresa, and Potsdam~ 

are present underneath the Black River limestone in the Watertown region, and that there is a 

great unconformity, both by erosion and by overlap, between the Theresa and Pamelia formations. The Pamelia formation is of upper Stones River age, and [is] thus a formation hitherto 

unrecognized in the New York section. It is thought that the unconformity mentioned can be 

traced down the St. Lawrence Valley to the Champlain meridian and represents the expanded 

western representative of the break discovered by Ulrich in the Champlain Valley between 

divisions A and B of the Beekmantown. It is also thought that it represents the proper line of 

division for northern New York between the Cambrian and Lower Silurian systems, thus relegating to the Cambrian nearly 400 feet of strata which have hitherto been classed as Beekmantown. 

Prior to the recognition of the "Theresa" and Pamelia formations, described 

above, the terms Beekmantown ("Calciferous"), Chazy, Lowville ("Birdseye"), 

Black River, Trenton, and Utica were used. Their general distribution and relations all about the Adirondacks have been stated by Cushing.203 

In 1910 Ulrich and Cushing 822a published a detailed study of the Little Falls 

dolomite of the Mohawk Valley, in course of which they developed the relations 

between the Little Falls dolomite and overlying strata. They class the dolomite 

as the uppermost Saratogan and separate it from the Beekmantown, with which 

it has hitherto been placed. They describe an unconformity at the top of the 

dolomite and take the plane of that unconformity as the basis of classification. 

They say: 

Our comparative study of the region has, we think, made clear the correlation of the Calciferous of the Champlain and Mohawk valleys and seems to us also to show that the Little Falls 

dolomite (division A and the lower part of B) does not properly belong with the Beekmantown, 

either structurally or faunally, and has been heretofore classed with it simply on the basis of supposed lithologic resemblance; that it is separated from the remainder of, or rather the true 
MIDDLE AND UPPER ORDOVICIAN. 187 

Beekmantown, by an unconformity, while it invariably grades into the Potsdam beneath 

through a seriljs of passage beds; and that faunally also its association is with the Potsdam, the 

Hoyt limestone of the Saratogan region being merely a more calcareous and more fossiliferous 

phase of its lower portion, of very local character, rather than a phase of the Potsdam. . 

Local sectibns of the Ordovician in the Mohawk Valley have been described 

with great detail and faunal lists are given in publications by Cumings, 195 Cushing, 202 

Prosser, 647 ' 652 Walcott, 845 and vVhite. 908• 909• 910 

The Champlain-Hudson Valley is here mapped according to the authorities 

cited by Merrill 592a for Clinton, Washington, Rensselaer, Columbia, Dutchess, Ulster, 

and Orange counties. The Ordovician of this region comprises, above the Beekmantown, the Chazy, Trenton, and "Hudson River." The Chazy is restricted to 

the northeastern section. 823 Near Albany the "Hudson River shales" are now 

recognized as representing, in ascending order, the Normans Kill, middle Trenton, 

Utica, and Lorraine. The Normans Kill shale is a clastic representative of the 

lower Trenton limestone of the western part of the State. 

rt·is convenient to take up the discussion at the north in Clinton County and 

to proceed southward. Cushing's general statement of the relations of the several 

Ordovician ·formations around the Adirondacks is quoted on page 186. The Chazy 

is thus described by Cushing: 201 

Brainard and Seely have recognized three subdivisions of the Chazy rocks. * * * The 

lower subdivision is largely constituted of quite crystalline limestones of gray color, often full 

of crinoidal fragments and with Orthis costalis the most abundant fossil; the middle division 

is of blue-black fine-grained limestone and contains Maclurea magna at nearly all horizons; the 

upper division is quite variable in character but is largely composed of somewhat impure blue 

limestones, carrying Rhynchonella plena abundantly. 

The aggregate thickness of the Chazy limestone at Chazy village is 7 40 feet, with the base 

not shown. On Valcour Island, Brainard and Seely give it a thickness of 890 feet, and there it 

seems to reach its maximum.a ' 

Brainard's section at Valcour Island 94 reads, in ascending order: 

Group A (Lower Chazy). 

1. Gray or drab-colored sandstone, interstratified with thin (or sometimes thick) layers of slate, 

and with occasional thin layers of limestone at the base, containing Camerella (?) costata Feet. 

Bill................................................................................. 56 

The slaty sandstone gradually passes into2. Massive beds, made up of thin alternating layers of tough slate and of nodular limestone, 

containing undetermined species of Orthis and Orthoceras.............................. 82 

3. Dark bluish-gray, somewhat impure limestone, in beds of variable thickness; often packed 

with Orthis costalis Hall, which occurs with more or less frequency through the whole 

mass. Other fossils are Lingula huronensis Dill., Harpes antiquatus Dill., Harpes ottawaensis Bill. (?), Ilhenus arcturus Hall ( =bayfieldii Bill.), Lituites sp. (?)................ llO 

. 4. Gray, tolerably pure limestone in beds 8 to 20 inches thick, separated by earthy seams, the 

bedding being uneven. Many layers consist of crinoidal fragments, largely of PalmoC'IJStites tenuiradiatus Hall. Near the middle of the mass, for a thickness of 10 feet, some of 

the fragments and small ovoid masses (Bolboporites americanus Dill.) are of a bright-red 

color, and these beds on the west side of Bluff Point are extensively quarried and furnish 

a fine marble for indoor use........................................................... 90 

Total thickness of A................................................................ 338 

a Ulrich regards this as a mistake, for in his judgment it robs the Beekmantown of its most essential pa;rt, namely, 

division D.-n. \\'. 
188 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Group B (Middle Chazy). Feet. 

l. Impure nodular limestone, containing Maclurea magna Lesueur. . . . . . . . . . . . . . . . . . . . . . . . . . 25 

2. Gray massive pure limestone, abounding in crinoidal fragments........................... 20 

3. Bluish-black thick-bedded limestone, usually weathering so as to show pure nodular masses 

enveloped in a somewhat impure lighter-colored matrix; everywhere characterized by 

Maclurea magna. Near the middle of this mass, for a thickness of about 30 feet, the fossils 

are silicified and of jet-black color. The more important, besides Maclurea, are species of 

Strophomena, Orthis, and Orthoceras. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210 

4. Dark compact fine-grained limestone, with obscure bedding, weathering to a light gray. 

This rock resists erosion and is the upper stratum at Bluff Point, sloping upward from the 

lake at an angle of 5° to a height of 170 feet. In one exposure the basal portion is densely 

oolitic. Fossils are infrequent, but at a single locality there were collected Orthis perveta 

Con., Orthis platys Bill., Leptxnafasciata Hall, Asaphus canalis Con., Cheirurus polydorus 

Bill., Harpes sp. und., Illxnus incertus Bill., Lichas minganensis Bill., Sphxrexochus 

parvus Bill., and several undescribed species.......................................... 20 

5. Bluish-black limestone like No.3, but less pure, containing Maclurea magna Lesueur, Orthis 

perveta Con., Strophomena incrassata Hall, Orthis borealis Bill. (?), Orthis disparilis Con., 

or 0. porcia Bill..................................................................... 75 

Total thickness of B. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350 

Group C (Upper Chazy). 

1. Dove-colored compact limestone, in massive beds, containing a large species of Orthoceras, 

Placoparia (Calymene) multicosta Hall, Solenopora compacta, and a large Bucania........ 60 

2. Dark impure limestone, in thin beds, abounding in Rhynchonella plena; at the base a bed 

4 or 5 feet thick is filled with various forms of Monticulipora or Stenopora............... 125 

3. Tough arenaceous magnesian limestone, passing into fine-grained sandstone............... 17 

Total thickness of C................................................................ 202 

Aggregate thickness of the Chazy on Valcour Island.................................. 890 

Raymond 660• 661 gives a classification of the faunal divisions of the Chazy 

(Herbertella exjoliata division, 1vfaclurites magna division, and Camarotcechia plena 

division) and distinguishes a number of faunal zones. He also discusses the distribution and correlation of the formation so far as it has been identified in Canada 

and the United States. 

The belt east of the Hudson has been mapped by Dale 207 • 208 from Lake Champlain south to the Kinderhook (latitude 42° 30'). The rocks are chiefly slate, range 

in age from Lower Cambrian to Lorraine, and are but sparsely fossiliferous. The 

areal distribution of distinct formations is not worked out and the divisions mapped 

by Dale are broad and indefinite. 

The post-Beekmantown Ordovician is included under the term "Hudson" and 

the stratigraphy is summed up as follows: 208a 
MIDDLE AND UPPER ORDOVICIAN. 189 

Table showing the Hudson formation as exposed in Rensselaer County and the northeastern part oj 

Columbia County, N. Y. 

-~----·-~-----

Metamorphic equivalent. 

Estimated 

Description of strata. Fauna. thickness Age. Estimated in feet. [Description.] thickness 

in feet. 

Black shale with arena- Diplograptus amplexi- ceous limestone, etc.a cauiis.IJ 

Black and gr& shale Normans Kill graptolite 

with inter bed ed grit. c fauna. 

Similar shale with lime- Trenton fauna in lime- r"''"' .chi~. hl~k. ) l ,000-2,000 

stone and limestone stone and cement of I green, or urple, in 

conglomerate. conglomerate.d 1,200-2,500? Trenton) places. wit£. greenish 

Black siliceous white- ····-------------------- quartzite up to 20 

weathering, ''cherty- feet thick. 

looking'' shale. e 

Reddish, p u r e l i s h , -----·------------------ greenish sha e, with 

small quartzite beds. e 

a See Ruedemann, Rudolf, Bull. New York State Mus. No. 42, 1901, pp. 535-537, stations 24, 25, 26. 

IJ See Ruedemann, op. cit., for other fossils. c Rarely with small beds of quartzite. d The pebbles of this conglomerate contain Trenton, Chazy, and Lower Cambrian fossils. See Ruedemann, Rudolf, 

Bull. New York State Mus. No 49, 1901, and Ford, S. W., Am. Jour. Sci., 3d ser., vol. 28,1884, pp. 206-208. [Regard 

this zone as overlying the true Normans Kill.] e The vertical relations of the colored shale and the black siliceous shale to each other and to the black and gray 

shale with Normans Kill graptolite fauna are not clear. They are all intimately associated. The greenish shale some- times includes small limestone beds. 

The presence of strata of Chazy, Trenton, and Lorraine age constituting the 

upper part of the Stockbridge dolomite in the compressed syncline near Rutland, 

Vt., was shown by the discovery of fossils by Wing in 1877. 216 and has been confirmed by Wolff 945 and by Dale. 205 

The faunal horizons of the "Hudson shales" in the ·vicinity of Albany have 

been worked out by Ruedemann, 678 who sums up his results as follows: 

This paper purports to demonstrate the presence of four zones of shales in the "Hudson . 

River shales" of the Hudson Valley region about Albany. These zones, which extend from 

north-northeast to south-southwest, consist, going from west to east, of shales containing the 

Lorraine, Utica, middle Trenton and Normans Kill graptolite faunas. The shales last named 

include lower Trenton conglomerate and rest on lower Trenton limestone. This succession of 

zones places the Normans Kill graptolite beds, which form the mass of the "Hudson River 

shales" in the Hudson River valley, between the middle and lower Trenton and determine, 

together with other facts, the lower Trenton age of these shales. 

The beds lie conformably inverted, on account of their being the remnant of the 

underturned wing of an overturned fold of Appalachian type. This fold has turned into an 

overthrust fault, which brought the Cambric beds as the next succeeding terrane above the 

Normans Kill shales. 

On account of the fact that the mass of beds hitherto called Hudson River shales and 

correlated with the Lorraine beds of central New York is composed of terranes ranging from 

the Lorraine to the lower Trenton, and on account of the lack of a fully representative fauna 

and of a complete section of the Lorraine portion of these terranes, it is proposed to drop the 

term "Hudson River shales" for the uppermost part of the Lower Siluric and the term "Hudson 

River group" for the Utica and Lorraine beds and to employ the term Normans Kill shales for 

the classic facies of a part of the lower Trenton which is characterized by the graptolite fauna 

at the Normans Kill. 
190 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The limestone conglomerate referred to in the above quotation was made the 

subject of refined study by Ruedemann, 679 with reference to the faunas of matrix and 

pebbles, origin of materials, and conditions of deposition. From this paper the 

following summary is taken: 

1. The investigation of the lower Siluric shales of the neighborhood of Albany has led to 

the observation of a conglomerate bed embedded in these shales and outcropping on Rysedorph 

Hill near Rensselaer, on the Moordener Kill near Castleton, and at Schodack Landing. 

2. The most interesting feature of this conglomerate is the fauna which the component 

pebbles and the matrix contain. To describe these and to obtain from them conclusive data 

as to the age of the inclosing Normans Kill shales is the principal purpose of this paper. 

3. The conglomerate contains a great variety of pebbles. In the southern outcrops, at 

Schodack Landing, nonfossiliferous sandstone pebbles prevail; going northward, fossiliferous 

limestone pebbles increase, and on Rysedorph Hill they are the principal components. 

4. The limestone pebbles are shown by their faunas to be derived, in very small number, 

from Cambric and Chazy rocks; more frequently from the Lowville limestone; and prevailingly 

from extremely fossiliferous black and gray limestone beds which are of lower or lowest 

Trenton age. 

5. A specially interesting feature of tho fauna of these Trenton pebbles was found in the 

considerable number of new forms, largely brachiopods, trilobites, and ostracods. Some of 

these belong to genera new to the American Trenton but well represented by very similar forms 

in equivalent north European beds. These, as well as several other forms which also occur 

in the Rysedorph Hill conglomerate and are restricted to the eastern Trenton, support the 

conclusion derived from the distribution of the Normans Kill graptolite shales, viz, that in 

lower Trenton time the eastern Trenton sea had attained connection with the Atlantic. 

6. As the fauna of the Trenton pebbles is in marked features different from that of the beds 

known in the Mohawk and Hudson valleys, it is supposed that the material was derived from 

the regions to the east and northeast, where the Trenton beds have now become metamorphosed 

and the fossils obliterated. 

7. The occurrence of the lower Trenton limestone pebbles in this region is taken to indicate 

that at the beginning of the-Trenton period the quiet limestone-depositing Trenton sea extended 

also over this region; while the presence of Normans Kill shale of lower Trenton age proves 

that this favorable condition soon came to an end, and a radical change in the physical conditions 

took place. 

8. The conglomerate itself is intraformational. It is embedded in shale of the same aget 

and the fauna of the matrix of the conglomerate is of lower Trenton age. The conglomerate, 

therefore, evidently does not mark any important change in the physical condition of the 

region but is probably due to a temporary elevation of a low Appalachian ridge into the sphere 

of wave action. 

This conglomerate closely resembles the conglomerate of the Quebec formation 

of Citadel Hill, Quebec, in its constitution, associated shales, and faunas. 

The rull statement of Ruedemann's studies of the graptolites is contained in 

two memoirs, to which reference should be made for adequate appreciation. The 

. first of these 680 deals chiefly with horizons discussed in Chapter II of this work; from 

the second 681 the following table is quoted: 
Correlation table of the graptolite zones of New York. a 

-~----~---~,-~------.-------------------,----------,---------,-----------

1

1' Distribution in North Corresponding zones in I System. Stage. Graptolite zone~ in New York. America. Great Britain and 1 Scandinavia. , 

Extra-American distribution. 

______ I ____________ ,1

1 

___________ 

1 

__________ ,1 __________ _ 

Siluric ... - -.... ·I Clinton beds ... __ . . Zone of Jfonograptus clintonensis and Retiolites ..................... _ . _ . Zone of Cyrtograptus I 

Cambric b._._ •. 

geinitzianus var. venosus. murchisoni. 

! 

Great Britain, France, 

Belgium, Scandinavia, 

Bohemia. 

1-----------------------j-----------;------------___ i ___________ _ 

Richmond beds(?) .. _ ........... _ ..................... _. __ ..... __ . _ ·I Zone of Dicellograptus Zone of Dicellograptus I 

Lorraine beds .... __ Zone of Diplograptus peosta and D.joliaceus mut. 

vespertinus. 

Frankfort shale..... Zone of Glossograptus quadrimucronatus mut. posterus. 

Utica shale ........ _ Zone of Glossograptus quadrimucronatus and Clima- . cograptus typicalis. 

complanatus in Indian complanatus. 

Territory. I 

Wisconsin, Minnesota ..... 1 .... __ . __ ... _ .......... . 

Ohio, Canada ....... _ .. _! .. , .... __ . _______ . _ - - ... 1

1 

Canada, Vermont, Penn-I Zone of Pleurograptus i 

sylvania, Ohio, Wis- linearis. ! 

consin, and Minnesota 

(Maquoketa shale and 

part of Galena?). 

Subzone of Climacograptus caudatus and Corynoides .... -..... -. -. -- -.. -- -- .. · · · · · · · · · · · · · · · · · · -·- - -. curtus mut. comma. 1 

Great Britain, Scandinavia. 

Great Britain, Scandinavia . 

Great Britain, Scandinavia. 

Upper Trenton ..... }Zone of Diplograptus amplexicaul is (Upper Dice!- Canada (Magog, Cove Zone of Dicranograptus ! 

Middle Trenton.... . lograptus zone). Fields, etc.). 'clingani. 

Lower Trenton ...... il] (Canada, New Jersey, Ala-] (Great Bntam, ScandiBlack River lime- z f N t T (N an K"ll h 1 ) bama, Arkansas, In- _ Zone of Nemagraptus ' navia, France(?), New 

stone and Low- oneo emagrap us gract ts orm 8 1 8 a e · dian Territory, Nevada,, gracilis. South vValcr', and Vicville limestone. British Columbia. i toria. 

Chazy limestone .... I Zone of Diplograptus dentatus and Cryptograptus Canada (Point Levis I Zone of Didymograptus Gre::tt Britain, Scandi- 1 antennarius (Third Deepkill zone). zone), Arkansas, Nc- geminus. navia. 

vada. 

I 

Subzone (transitional zone) with Didymograptus ...... __ ................ _ .. __ .. _ ... _. _. _ ..... . 

forcipijormis (Ash Hill quarry). 

. (z f D 'd b fid d Ph ll Canada (St. Anne zone), !Zone of Didymograptus Beekmantown lime- I one 0 1 ymograptus 1 us an Y ograptus Newfoundland. bifidus and Phyllostone : anna. Canada(mainPointLevis graptus typus (Upper • 1 Zone of Tetragraptus ................ -... -. -. . . . . . zone). Tetragraptus zone). 

Subzone b of Goniograptus. Zone of Tetragraptus 

I 

Schaghticoke shale .. j 

I 

I 

Subzone a of Clonograptus. (Lower Tetragraptus 

I 

and Dichograptus 

zones). 

-'1-----------1 

Zone of Dictyonemajlabellijorme................... Canada (Gaspe, St. John). Zone of Dictyonema jlabellijorme. 

Great Britain, Scandinavia, France, Bohemia, Victoria. 

Great Britain, Scandinavia, France, Victoria. 

Great Britain, Scandinavia, 'Esthonia, Belgium. 

a This in part replac.es thA correlation table in Memoir 7 (facing p. 490). b It is still a mooted question whether the shale of Dictyonema flabellijorme constitutes the last horizon of the Cambric or the first of the Champlainic (Lower Siluric), 

and several authors have lately inclined to the latter view. 
192 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

In the southern part of the Hudson Valley the Ordovician divides around the preCambrian of the Highlands. In the eastern area the strata are more or less metamorphosed; they are described with the similar slates and schists of New England (below). 

The western area extends through Ulster and Orange counties to New Jersey. 225 

Ries 673 recognized in Orange County the Trenton limestone and the "Hudson 

River slates." Of the limestone he mentions one occurrence near Newburgh Ferry. 

The slates are widely distributed. 

In the western part of the county the formation is represented by interbedded shales and 

red and brown or gray sandstones, while in the central part the slates and shales only appear. 

The sandstone beds again come in toward the northeast. Conglomerates are occasionally seen 

in the northeastern part of the county. * * * Fossils are rare but have been found at several 

localities. * * * They show a mixed Hudson River-Trenton fauna. * * * These rocks 

rest unconformably on the Cambrian limestones and gneisses and underlie younger rocks in 

the same manner. Their thickness in this county is probably not less than 2,000 feet. 

X-L 18-19. VERMONT, NEW HAMPSHIRE, MASSACHUSETTS, AND CONNECTICUT EAST OF 

THE GREEN MOUNTAINS. 

The presence of middle Ordovician strata in Vermont, in continuation of the 

Canadian occurrences, is probable, but their distribution is not known. They 

probably lie in synclines, overthrust by Cambrian and below remnants of the Silurian, which here, as in New Brunswick and eastern New York, is probably unconformable to the older strata. The structure is much confused by folding, thrusting, 

and igneous intrusions. In Canada immediately north of the international boundary 

Ells 312 has traced out the divisions of the "Quebec group" and distinguished the 

belts of graptolitic slates of the Ordovician. (See pp. 132-134.) The southward 

extension into New Hampshire and Vermont was described by Hitchcock 452• 

453 as 

the Calciferous mica schist and the Coos group. 

In M·assachusetts and Connecticut the upper part of the Stockbridge dolomite 

is of Beekmantown, Chazy, and Trenton age and the Berkshire schist is assigned to 

the general position of the "Hudson River"-that is, to Trenton and later Ordovician, the upper limit being indeterminate. 

Along the boundary between New York on the west and Vermont, Massachusetts, and Connecticut on the east extends the Taconic Range, the area of the 

Taconic system of Emmons. Dana published the results of his prolonged study of 

the structural relations and his conclusions as to the true order of the strata of the 

Taconic Range in a series of papers in the American Journal of Science (1872-

1887).218•219 He also summed up the history and facts in the Quarterly Journal,217 

The early discoveries of fossils by Wing (see p. 189) were followed by W alcott's discoveries in the central Taconic area, which prove~ the Cambrian and Ordovician age of the strata. Walcott 849 distinguished the rocks of certain areas as 

"terranes" and concluded that terrane 3, the upper part of the Stockbridge dolomite, was equivalent to the "Calciferous" (Beekmantown), Chazy, and Trenton limestones of the Champlain-Hudson Valley and terranes 4 and 6 were of "Hudson" age. 

In Berkshire County, northwestern Massachusetts, lies Mount Greylock, which 

is composed of the Stockbridge dolomite and overlying strata. Dale 206 worked 

out its structure and gives the following tabulation of the stratigraphy as determined by him, in comparison with other classifications: 
• 

General lithologic character, order, and estimated thickness of the strata of Mount Greylock, East Mountain, and Stone Hill. 

I Age. 

Formations (natu- Lithologic character. Thickness 

ral order). (feet). 

I 

Emmons, 1855. Hall, 1839-1844. Dana, 1882-1887. IV alcott, 1888. 

---- ---- I 

Grey lock schist ... :Muscovite (sericite), chlorite, and quartz schist, 1,500--2,000 Pre-PoC,d=. __ _ _ _ _ _ -~ Trenton (Hudson Lower Silurian ... Trenton (Hudson 

with or without biotite, albite, magnetite, tabu- Lower Taconic No. 3. River). River). 

Jar crystals or lenticular plates of interleaved '' Talcose or magneilmenite and chlorite, ottrelite, microscopic ru- sian slate." 

tile, and tourmaline. These schists are rarely 

calcareous or graphitic. 

Bellowspipe lime- Limestone, more or less crystalline, generally mi- 600--700 Pre-Potsdam ........ _ ... Trenton (Hudson Lower Silurian .... Trenton (Hudson 

stone. caceous or pyritiferous, passing into a calcare- Lower Taconic No. 3. River). River). 

ous schist, or a feldspathic quartzite, or a fine- Included in "Talcose 

grained gneiss with zircon and microcline, or a or magnesian slate." 

schist like the Berkshire schist. The more com- mon minerals are graphite, pyrite, albite, and 

microscopic rutile and tourmaline. More rare, 

galena, zinc blende, siderite. 

Berkshire schist ... Muscovite (sericite), chlorite, and quartz schist, 1,000-2,000 Pre-Potsdam ......... _ .. Trenton (Hudson Lower Silurian .... Trenton (Hudson 

with or without biotite, albite, graphite, mag- Lower Taconic No. 3. River). River). 

netite; frequently with tabular crystals or len- "Talcose or magneticular plates of interleaved ilmenite and chlo- sian slate." 

rite. Garnet, ottrelite. Microscopic rutile and 

tourmaline. These schists are in places calcareous, especially toward the underlying limestone, where they are often graphitic. 

Stockbridge lime- Limestone, crystalline, coarse or fine; in places a 1' 200--1' 400 Pre-Potsdam .......... _. Lower Silurian Lower Silurian .... Trenton ( T r enstone. 

I 

dolomite, sometimes quartzose or micaceous, Lower Taconic No. 2. (Trenton and 

I 

to n ) ; Car.adian 

more rarely feldspathic, very rarely fossilifer- "Stockbridge lime- lower). (Chazy, Calcifous. Galena and zinc blende rare. Irregular stone." erous). · 

masses of iron ore (limonite) associated some- times with siderite, often with manganese ore (pyrolusite). Some quartzite. 

Vermont formation Quartzite, fine grained, alternating with a thin- 800--900 Pre-Potsdam ............ Cambrian (Pots- Cambrian ··---------------- Lower 

bedded micaceous and feldspathic quartzite Lower Taco11ic No. 1. dam). ( Olenell us). 

(the Ia tter with calcite, pyrite, tourmaline). "Granular quartz." 

Associated with these quartzites, and probably I 

at the base of this honzon, is a coarse-grained 

micaceous quartzite (tourmaline), J?assing in 

places into a conglomerate and con taming blue 

quartz, feldspar (plagioclase, microcline), and 

zircon, all of clastic origin. 

! Total thickness: 

Minimum .................. _ ........ 5,000 

i Maximum .............. _._ ......... 7,200 

! I -~--

- - -~------- ---
194 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

In the same monograph Pumpelly 654 describes the structural and stratigraphic 

grounds for correlating the Cambrian and Ordovician strata of Mount Greylock 

with the Hoosac schist on the east. The latter is mapped as Cambrian and OrdoVICian. (See Chapter III, p. 114.) 

In southwestern Massachusetts and adjoining parts of Connecticut and New 

York lies the Mount Washington mass of the Taconic Range, which has been more 

particularly studied by Hobbs/55 who distinguished four formations apparently 

equivalent to those recognized by Dale, namely: -------~--~ ----~"--- ------------,-------------

Mount Washington, Hobbs. Mount Greylock, Dale. 

Top. 

Everett schist ............................................ _ .... ~ . . . . . . . . . . . . . . . . Grey lock schist. 

Egremont limestone ......................................... ~-. ~................ Bellowspipe limestone. 

Riga schist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Berkshire schist. 

Canaan dolomite ............ _ ~ _ ~ ................ _....... . . . . . . . . . . . . . . . . . . . . . . . Stockbridge limestone. 

Ordovician strata, which, though highly metamorphosed by igneous injection, 

are identified as representatives of the Stockbridge dolomite and "Hudson shale," 

form part of Manhattan Island, New York. 593 They have been traced through 

eastern New York and western Connecticut to the fossiliferous area of the Taconic 

Range, first by Dana, and later by Gregory. 387 

L 12. SOUTHWESTERN MONTANA. 

There is no recognized break in the sequence of lower Paleozoic strata which 

appear around the uplifts of southwestern Montana; and yet no strata which may 

certainly be referred to the Ordovician are known there. Apparently but slight 

record of marine or land conditions was made in the region during that long time. 

L 16. UPPER PENINSULA OF MICHIGAN. 

Rominger 677 a describes in detail the occurrence of "Chazy and Calciferous, 

Trenton, and Hudson River" strata in the Upper Peninsula of Michigan. The distribution of the formations as shown on the map of North America is taken from 

the geologic map of Michigan published by the present Survey, and the following 

notes are abstracted from a paper by Lane. 517 

Lane describes in ascending order St. Peter sandstone, Trenton limestone, 

Utica shale (Eden of Ohio), and Lorraine or Maysville shale as formations composing 

the Ordovician between the "Calciferous" and his "Richmond and Medina transition beds." 

The St. Peter sandstone does not outcrop in Michigan but is recognized in well 

drilling as a quartz sand between the "Trenton" limestone above and the "Calciferous" limestone below. Its thickness is very irregular, presumably because it 

lies on an uneven surface. 

The "Trenton" of northern Michigan, according to Lane and Grabau, comprises the equivalents of the Chazy, Black River (Lowville or "Birdseye" and Black 

River of present usage), and Trenton of Hall's classification in New York, or the 

Chazy and Mohawkian of the present New York State Survey classification. The 

base of this limestone is the passage into the St. Peter sandstone, or, where that is 
MIDDLE AND UPPER ORDOVICIAN. 195 

lacking, the contact with the "Calciferous" (lowermost Ordovician) or the preCambrian, upon which it overlaps. The passage from the "Trenton" limestone or 

dolomite to the overlying shale described by Lane as the Utica is well marked lithologically. Lane states the thickness of the " Trenton" as 250 to 271 feet. It is 

in places dolomitic. Subdivisions in the Green Bay region are recognized by him 

as follows: 

Galena limestone: Feet. 

[Limestone,] crystalline, granular..................................................... 83 

Limestone, fossiliferous 55 feet, white 8 feet, dark 9 feet ............... ·................. 72 

Alternating blue and brown, crystalline, granular. With the dark base compare the \Visconsin oil rock.......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 

Sandy limestones, ''quartz" 6 feet, limestone 44 feet, quartz 1 foot, limestone 24 feet; compare 

quartz sandstone at Marinette at 260-275 feet............................................. 75 

Wisconsin Trenton (Platteville?), blue shale and limestone (blue shale 4 feet, black limestone 

141 [14 ?] feet, limestone 19 feet, blue shale 4 feet)....................................... 41 

The formation recognized by Lane as the Utica shale is described as a black 

shale ranging in thickness from 50 feet at the north to about 200 feet at the south. 

The formation described by him as Lorraine or Maysville is an abundantly fossiliferous blue shale which he correlates with the Maquoketa of Iowa. 

Lane groups certain coarser deposits and residual red clays formed from limestone as "Richmond and Medina transition beds." The former he places in the 

Ordovician, the latter in the Silurian, although he does not doubt that Ulrich is 

right in placing the Richmond of Indiana in the Silurian. He states, however, 

that in this region the strata to which he applies the name Richmond are so closely 

associated with the underlying shales, being included with them in many well 

drillings, that it is not convenient to separate them from the Ordovician. The 

strata described by Lane as Richmond and Medina consist of red and green shale, 

with some limy beds, and vary in thickness from little or nothing to about 142 feet 

at Cheboygan, thickening toward the south. 

Ulrich in commenting on Lane's view states that the Utica and Lorraine do not 

outcrop in Michigan, but that the "Trenton" is succeeded by the Maquoketa, of 

Richmond age, with a hiatus between equivalent to the Eden, Utica, and Maysville 

of the Cincinnati section. 

L 17. :MANITOULIN ISLANDS. 

The east end of Great Manitoulin Island, Ontario, falls within the area mapped 

on the French River sheet. In reporting on that area Bell 67 summarized the results 

of his own work and that of his colleagues in preceding years. The several formations of the later Ordovician-" Chazy~, Trenton, Utica, and Hudson"-are 

described in some detail. To the Chazy are doubtfully assigned the lowest beds of 

the Paleozoic in this region, certain chocolate-colored marls, with some fine sandstones, 100 feet thick. Bell obtained no fossils from these strata, but Ami 24 states 

that "Billings notes in a list of fossils from the island farthest south of the group, 

off Point Pallideau, Lake Huron, the occurrence of ]}fodiolopsis parviuscula, 

Vanuxemia inconstans, Pleurotomaria staminea, and Lingula huronensis, species 

known to occur in the Chazy of different portions of Ontario, notably in the MontrealOttawa-Champlain basin." 
196 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The "Trenton group" is represented by gray limestones with shaly and marly 

beds, approximately 320 feet thick. Locally these strata rest upon the Ste. Marie 

sandstone 544e or directly upon the pre-Cambrian quartzite ledges of the northeastern islands (Badgely Point, etc.), where they carry Black River fossils. Ami a 

cites a number of collections of fossils from these strata. 

"Hudson River" strata of the islands are described as bluish-gray and drab 

marls and shales, interstratified with thin limestone and fine-grained sandstone, 

altogether 250 to 300 feet thick, including a 30 to 40 foot band of limestone at the 

top. Ami states: 

It is extremely desirable that further collections be obtained from the Ordovician and 

Silurian succession of the Manitoulin Island district of Lake Huron, inasmuch as the sedimentation of that area is not only quite distinct from that of the Niagara and Toronto districts on the 

Ontario basin, but bears strong resemblance to the succession known and recorded in Indiana, 

Ohio, and Kentucky to the south, as well as to that of the Island of Anticosti, in the valley of the 

St. Lawrence, east. 

The beds called Utica shale are described as black and bituminous and 60 feet 

thick. S'ome of the collections (Nos. 14-20) contain faunas which appear to indicate 

the presence of the summit beds of the Ordovician, either Lorraine or Richmond; 

elsewhere Lorraine (21-22) and Richmond (23-32) have been distinctly recognized. 

To the Clinton (Medina strata being absent) are assigned drab, buff, and purplish 

magnesian limestones. 

L 17. LAKE NIPISSING, LAKE TEMISCAMING, AND MATTAWA. 

Outliers of Ordovician limestone containing Black River and Trenton faunas 

occur on islands in Lake Nipissing, Lake Temiscaming, and 6 miles below Mattawa, 

. on the Ottawa.55 They are too small to be shown on the map but are important, 

as their correlation, according to Ami, 15a shows "that in Ordovician times the marine 

waters of the Lake Huron Paleozoic basin were directly connected with those of the 

Nipissing and Mattawa or Upper Ottawa regions." 

L 18-19. ST. LAWRENCE VALLEY. 

The distribution of the Ordovician, exclusive of the Beekmantown (" Calciferous"), in the St. Lawrence Valley as here mapped is taken from the map sheets of 

Ontario and Quebec. The line at the base is that between the "Calciferous" and 

Chazy, and that part of the Ordovician above this line comprises the equivalent of 

the Chazy, Lowville ("Birdseye"), Black River, Trenton, Utica, and Lorraine of 

the New York section. The Pamelia limestone 204 and the underlying but unconformable "Theresa formation" have also been traced in the latest work (1908) .a 

The southwestern or upper part of the St. Lawrence Valley is known in Canadian 

geology as the Ottawa Basin. This basin is bounded on the southwest by the 

Frontenac axis, the belt of pre-Cambrian rocks which crosses the St. Lawrence and 

connects with the Adirondack area. On the east a similar area of older rocks, 

eroded to the Potsdam sandstone, separates the Ordovician of the Ottawa basin from 

the equivalent Ordovician strata that extend from Montreal to Quebec, down the 

north side of the St. Lawrence Valley. 

a Ami., H. M., personal communication, Sept., 1908. 
MIDDLE AND UPPER ORDOVICIAN. 197 

The St. Lawrence Valley east of the river between Montreal and Quebec is divided 

by the St. Lawrence-Champlain thrust fault into two zones, the line of division, 

according to Logan, 544h passing through Quebec and curving thence to Lake Champlain. Strata that occur southeast of this line differ in lithology and faunas froih 

those of probably equivalent age that are found northwest of it. The facies differ 

across the thrust fault. Those of the northwestern zone (Ottawa, Montreal, Quebec) 

may be described under the New York names cited above, but those of the 

southeastern zone ("Eastern Townships") belong to the Sillery, Levis, and Quebec 

formatiohs (named in ascending order), which constitute the old Quebec group of 

Logan and Billings. The Sillery (Cambrian) and Levis (Beekmantown or "Calciferous") are described in Chapter III (pp. 131-134). The Quebec formation 

(restricted) is the equivalent of the upper Chazy and lower Trenton.16b, 853 

In Ells's report on the geology of the area shown on the Three Rivers map 

sheet 314 occurs the following table, which is based on correlations by Ami: 

Formations. Character of strata, etc. 

System. 1-------c--------1·-------·--,-------------

\Vest of fault. I East of fault. West of fault. East of fault. 

-----~----·-- 1------1--------· --1---------

Silurian .......... _ . _ _ Medina ........ _ .... __ ... . . . . . . . . . . . Red shales and sandstones. 

stones. 

Utica ............... _ .. _ ............ Black bituminous shales .. !

Lorraine ............ __ .............. Grayish shales and sandTrenton .......... _. } {Limestones .............. _ }Black graptolitic shales 

Cambro- Silurian or (Farnham)..... and black or dark imOrdovician. ]Black River........ Limestones .............. _ pure limestones. 

Chazy ......... _ .. _ .. _ ............. Chiefly limestone; shale 

in lower part. 

Calciferous ......................... _ Magnesian limestones .... . Potsdam ........... __ ......... _ . . . . Sandstones .......... _ ... . Cambrian............ . . . . . . . . . . . . . . . . . . . . Sillery ... _..... . . . . . . . . . . . . . . . . . . . . . . . . . . Red and gray and green 

slates and greenish-gray 

sandstones. 

Archean ............. Grenville .......................... Gneisses and limestones 

with granites and igne- ous rocks. 

It is convenient to consider the formations northeast of the St. LawrenceChamplain fault separately from those southeast of it. We first take up the 

Ottawa basin. 

The Paleozoic rocks of the Ottawa Basin are bounded on the southwest by the 

Frontenac axis, an outcrop of pre-Cambrian rocks which extends across the 

St. Lawrence into New York and connects with the Adirondack mass; beyond 

this axis to the southwest along the upper St. Lawrence and Lake Ontario is 

another area of Ordovician strata, in which the section differs somewhat from 

that of the Ottawa Basin. Ami 20 contrasts them as follows: 

Ordovician east of the Frontenac axis. 

VII. Lorraine: Buff-weathering and dark siliceous shales and mudstones. 

VI. Utica: Dark-brown and black bituminous shales and limestones at the'base. 

V. Trenton: Dark-gray impure and semicrystalline fossiliferous limestone. 

IV. Black River: Heavy-bedded and hard compact fine-grained impure limestones, etc. 

III. Chazy: Limestones, shales, sandstones, and grits; shallow water deposit at the base. 

II. Beekmantown (Calciferous): Dark-gray impure magnesian limestone or dolomites, cavernous 

and fossiliferous. 

I. Potsdam: Light-yellow and rusty-colored sandstones and conglomerates; shore deposits resting 

on the Archean crystallines. 
198 INDEX TO 'rHE STRATIGRAPHY OF NORTH AMERICA. 

Ordovician west of the Frontenac axis. 

V. Lorraine: Arenaceous shales and mudstones, at times very fine-grained argillites. 

IV. Utica: Dark-brown and black fossiliferous shales, etc. 

III. Trenton: Gray impure fossiliferous limestones. 

II. Birdseye and Black River [Pamelia, Lowville, and Black River]: Heavy-bedded impure fossiliferous limestones and fine-grained compact lithographic beds at the base. 

I. Rideau [Ste. Marie a]: Mostly red and yellow (at times green) colored sandstones; shallowwater deposit; false bedding prevalent; a basal series resting unconformably upon the subjacent Archean crystallines [Chazy.-B. W.]. 

The following tables of the geologic formations which make up the Ordovician 

ne.ar Ottawa, Montreal, and Quebec, northwest of the St. Lawrence-CLamplain 

fault, are taken from a paper by Ami. 16" 

[Part of] synoptical table of the geological formations about Toronto, Ontario. 

System. 

Ordovician. 

Unconformity. _,

1 

Pre-Cambrian. 

Formation. 

Lorraine ....... . 

Utica _____ ..... . 

Trenton ....... . 

Birdseye and 

Black River. 

Character of strata, etc. [ Characteristic fossils. Thickness. 

:----------------------1-------------------

Light yellowish green 

and gray calcareous 

and magnesian and arenaceous shales or mudstones, s o rn e very fine grained ar- gillites, bluish gray in 

color. 

Dark-brown and black 

bituminous shales 

(only reported and 

observed in drillings 

from deep wells). 

Dark and light gray and 

yellowish:gray i rn- pure fossiliferous limestones with shaly partings. 

Dark-gray impure, but 

also and for the most 

part fine-grained com- pact yellowish-gray 

lithographic l i me - stone, with basal beds 

of a calcareo-arena- ceous or arkose na- ture. 

Diplograptus hudsonicus 

Nicholson, Monotrypella 

undulata Nich., Zygospira 

headi Billings, Platystrophia biforata Schlotheim, v. lynx Eichwald, Drepanodus arcuatus Hinde, Distacodus incurvatus Hinde, 

Pronodus? politus Hinde, 

Lyrodesma poststriatum, 

Liospira subconica Hall, 

Modiolopsis modiolaris 

Hall, Byssonychia radiata 

H., Modiolopsis pholadiformis H., Orthocecus lamellosum H., Ormoceras 

crebriseptumH., Triarthrus 

becki Green, Favistella stellata H., T. calycina N., 

Tetradium minus Safford. 

The characteristic fossils of 

this formation as exposed 

at ·Whitby and vicinity 

east of Toronto are Leptograptusjlaccidus Hall, Orthograptus quadrimucronatus H., Leptobolus insignis 

H., Schizocrania filosa H., 

Zygospiramodesta Say, Lyrodesma pulchellum Ernmons, Trocholites ammo- nius, Triarthrus canadensis 

Smith, T. becki Green. 

Diplotrypa sp., Dicranopora 

sp., Plectambonites sericea 

Sowerby, Orthis (Dalmanella) testudinaria Dalman, 

Rhynchotrema sp. 

Isochilina lithographica n. s .. 

Between 600 and 650 

feet. Varies in thick- ness in different ex- posures. Thickness 

depends upon amount 

of denudation and ero- sion. 

About 100 feet. 

About 550 feet in bore 

holes. 

About 160 feet in "bore 

holes. 

a According to a personal communication from Dr. Ami, the sandstones at Rideau are of Potsdam age. They 

are not of widespread occurrence in this district. Sandstones which are similar but are of Chazy age locally form the 

base of the Ordovician succession (Storrington, near Kingston, and island off Pallideau) and were described by Logan 

(Geology of Canada, 1863, p. 196) as the Ste. Marie sandstone. Hence in Dr. Ami's judgment Rideau in this section 

must give place to Ste. Marie.-B. W. 
MIDDLE AND UPPER ORDOVICIAN. 199 

[Part of] synaptical table <>J geological formations about Ottawa, Canada. 

------------~------------.-------------------~----------------------~-------------

System. 

Silurian. 

Formation. Character of strata, etc. 

Medina .... _.... Bright brick-red argilla- ceous and arenaceous shales or marls, occa- sionally spotted or mottled green. 

Characteristic fossils. 

No fossil organic remains 

have as yet been detected 

in these shales. 

Thickness. 

About 100 feet in thi~kness. On one of the 

outliers examined a 60-foot well was sunk 

in these shales. 

---- ---- ------ ------------- --------------------l------,----------------1-------------------

Ordovician. 

Lorraine. ___ ._ .. Buff-weathering finegrained brittle shales 

and mudstones, at 

times arenaceous. 

Utica ........... Dark-brown and black 

bituminous soft shales 

and limestone bands 

interstratified in the 

basal portion of this 

formatwn. 

Trenton ........ Nodular and evenly 

bedded, for the most 

part bluish-gray,lightweathering Impure 

limestones and shales, 

fossiliferous, marine 

sediments, in part 

bituminous, cherty. 

Zygospiraheadi Billings, Byssonychia radiata Hall, 

Modiolopsis modiolaris 

Conrad, M. pholadiformis 

Hall, Liospira subconica 

Hall, Calyrnene senaria 

Conrad, Cyrtolites ornatus 

Con. 

Leptograptus flaccidus Hall, 

Orthograptus quadrimucronatus Hall, Schizarnbon 

canadensis Ami, Schizocrania filosa Hall, Batostomella erratica Ulrich, Turrilepas canadensis Henry 

Woodward, Stephanella 

sancta Hinde, Triarthrus 

spinosus Billings, Asaphus 

latimarginatus Hall (=A. 

canadensis Chapman) Endoceras tenuistriatum Hall. 

Licrophycus ottawaensis Billings, Pasceolus globosus 

B., Astylospongia parvula 

Billings, Streptelasrna cor- niculum Hall, Archxocrinusmicrobasalis Bill., Cleiocrinus magn~fic:us B., 

Glyptocrinus rumulosus B., 

Heterocrinus canadensis B., 

Iocrinus subcrassus M. and 

W., Reteocrinus stellaris B., 

Amygdalocystites florealis 

Bill., Ateleocystites huxleyi 

B., Comaror:~jstites punctaIus B., Pleurocystttes filitextus B., Agelacrinites 

dicksoni B., Monticulipora 

billingsi Foord, Batostoma 

ottawaensis Foord, Prasopora selwyni Nicholson, 

Solenopora compacta B., 

Orbiculoidea circe B., Slcenidium merope B., R.afinesquina alternata Conrad 

(Emmons), Trematis ottau·aensis B., Ambonycln:a 

arnygdalina B., Pterinea 

trentonens·is Conrad, Conularia trentonensis H., Protowarthia cancellata Hall, 

Eccyliomphalus trentonensis Con., Ophileta ottawaens·is B., Trochonema 

umbilicalum II., liormotoma bell'icincta II., Ortho- ceras python B., 0. otta- waense B., Serpulites dissolutus B., Zygospira re- curvirostra II., Isotelus gigas De Kay, Bronteus lunatus B., Harpes ottawaensis B. 

Exact thickness not as- certained, but probably not less than 100 or 150 feet. 

From 60 to 75 feet. 

From 450 to 500 feet. 
200 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

[Part of] synaptical table of geological formations about Ottawa, Canada-Continued. 

System. ! Formation. Characteristic fossils. Thickness. 

I Birdseye and 

Character of strata, etc ·I 

------------1-----~---------

Ordovician. 

Black River. 

Chazy ........ . 

Calciferous 

[Beekmantown]. 

Fine-grained and com- pact light-gray impure limestones, ma- rine and fossiliferous, some beds massive, 

others shaly and nodular. 

I 

Light-gray impure finegrained and concre- tionary and fossilifer- ous limestones, ce- _ment rock. 

Yellowish-gray calcareous and arenaceous shales, rusty-weathering, with phosphatic 

nodules. 

Arenaceous shales and 

sandstones and magnesian bands, fine 

grained and light yellow weathering. 

Magnesian limestones, 

fine a n d c o a r s e 

grained buff-weathering, hard and cherty, 

at times soft and sac- charoidal or arenace- ous and holding cavities lined with crystals of quartz, passing 

down into arenaceous layers or sandstones. 

Stromatocerium r o go sum Hall, Receptaculites occidentalis Salter, S treptelas- ma profundum Hall, TetradiumfibratumSafford, Columnaria halli Nicholson, 

Maclurea logani Salter, 

Gonioceras anceps Hall, 

Heliocotoma planulata Salter, Or this tricenaria Conrad, Strophomena incurvata Shepard, Cyrtodonta 

subtruncata Billings, Cyrtoceras sinuatum B., Onco- ceras constrictum Hall, Actinoceras bigsbyi Stokes, 

Orthoceras rapax B., Illm- nus ovatus B., I. conradi B. 

Leperditia canadensis Jones, 

Isochilina ottawa J., Camarotmchia plena Hall, Dinarthis platys Hall, Orthis 

(Hebertella) borealis, Billings. 

Lingula belli Billings, Modiolopsis parviuscula B., Ctenodonta n. sp., Cyrtodonta 

breviuscula B., Serpulites 

sp., Scolithus, n. sp. 

Orthis imperator Billings, 

Asaphus canalis Conrad, 

Lingula lyelli Billings. 

Cryptozoon calciferum Dawson, Ophileta complanata 

Vanuxem, Ilormotoma anna Bill., 0. disjuncta 

B., Orthoceras lamarch B., 

Pleurotomaria gregaria B., 

Ribeiria calcifera B. 

About 150 feet. 

About 20 feet .... __ _ 

...; 

Q) 

Q) 

30 feet ........... _. ··1§ 

150 feet ............. . 

250 to 300 feet. 

-------~-P-ot_s_d_a_m-.. -.---.-.-. ~L-ig_h_t-~y_e_ll_o_w __ o_r_~_h_i-te--O-p-h~---~-et_a_s __ p___ c_f ___ O ___ c_o_m_p_l_a_-'_A_b_o_u_t_2_0_0_f_e_et-.----------

and light-colored, at nata Van. Orthoceras sp., 

times rusty-weather- Scoi'ithus canadensis Bill1 

mg sandstones with ings, Climactichnites will conglomerates at the soni. Logan, Protichnites I base. septem-notatus Owen. Unconformitv.~ --------1~------------I-------------I------------

Pre-Cambria;l. I 

[Cam brian.] 

----------------'--------------------------···-------------

[Part (~f] syno ptical table of geological formation'S about .Llfontreal, Canada. 

Formation. Character of strata, etc. I Characteristic fossils. Thickness. 

I 

System. 

--···· - -----------·---

Nepheline syenite, dole- Forming conspicuous rite, trachyte, brec- ~one. masses coming through Eruptives. cias, diorites, olivine the Ordovician plain. diabase, dikes, etc. 

Post-Devonian. 

[Unconformity.] 

I 

Spirifer mesacostalis Hall 

ascertained. Oriskany and Fragments of light-gray (teste Prof. H.S.Williams); Not I soHamilton(?). impure fossiliferous Spirifer cumberlandim, s. lated patches and fraglimestone. pennatus?, S. arenosus?, ments. 

Devonian. j 

I 

etc. 

[Unconformity.].c____ _____ ____c ______ -'--___ .c____ ___________ c____ 
• 

MIDDJ_.E AND UPPER ORDOVICIAN. 201 

[Part of] synaptical table of geological formations about Montreal, Canada-Continued. 

! 

System. Formation. I Character of strata, etc. Characteristic fossils. Thickness. 

_,------1------- --1------------1-----------

Silurian. 

ru nconformity .] 

Ordovician. 

[17 nconformity .] 

[Pre-Cam brian.] 

Lower Helderberg. 

Light-gray impure subcrystalline and altered 

li1nestone, as small 

outliers. 

Leptxna rhomb01:dalis, Strophodonta varistriata, Strophonella punctulifera, Pentamerus ( Sieberella) galeatus, 

Atrypa reticularis, Platyostoma depressum. 

Only a few feet thick, 

preserved near some 

protecting dike oferuptives. 

Lorraine........ Black or dark-brown and 

buff-weathering shales 

and arenaceous beds 

and mudstones; fossiliferous. 

Favistella stella.ta, Orthograptus g_uadrimueronatus, Zygosptra headi, Pterinea demissa, Byssonychia radia.ta, 

Clidophorus planulatus, 

From a few feet to 400 or 600 feet, and runs to 

the south and west. 

Utica .......... . 

Trenton ....... . 

Black River .... 

Chazy ......... . 

Calciferous ..... 

Potsdam ...... . 

Dark-brown and black 

bituminous shales or 

pyroschists with impure limestone bar:ds 

at base; fossiliferous. 

Dark-gray impure fossil- . iferous limestones and 

s hal e s extensively 

quarried for building 

purposes; at times 

semicrystalline. 

Light-gray weathering, 

dark-gray and black 

i m p u r e fossiliferous 

limestones; building 

stone. 

Light and dark gray 

semicrystalline impure fossiliferous limestone; usefulfor building purposes. 

Orthodesrna parallelum, 

Protowarthia cancellata, 

Cyrtolites ornatus. 

Leptograptus jlaccidus, Lep- Between 100 and 450 

tobolus insignis, Schizo- feet. 

crania fllosa, Cornulites immaturum, Endoceras proteriforme v. tenuistriatum, Triarthrus . becki, Trocho lites ammon~us. 

Glyptocystites logani, lletero- Between 400 and 500 

crinus tenuis, Pachydictya feet. 

acuta,Phylloporina trentonensis, Prasopora selwyni, 

Plectambonites sericea, Trematis montrealens·is, Dalmanella testudinaria, Lingula riciniformis, Parastrophia hemiplicata, Rafinesquina alternata, P latystrophia lynx, Cyclonema mon- trealense, Trochonema um- bilicatum, Conularia trentonensis, Trinucleus con- centrints, Isotelus gigas, 

Calymene senaria. 

Tetradiurn jibratum, Colum- About 75 feet. 

naria halli, Strornatocerittm 

rugosum, Helicotoma planulata., Cyrtodonta huronensis, Bathyurus extans. 

Bolboporites americanus, Ma- Between 150 and 200 

locystites murchisoni, Blas- feet. 

toidocrinus carcharixdens, 

Camarotrechia plena, Hebertella borealis, Dinorthis 

platys, Ba.thyurus angel·ini. 

Dark-gray, buff and yel- Orthisina grandxva Billings, Between 200 and 250 

lowweatheringimpure Pleurotornaria calcifera. B., feet. 

earthy and semicrys- P. canadensis B., H ormo- talline limestones, for toma anna B., .Metoptoma 

the most part magne- simple.x B., Orthoceras lasian, and holding nu- rnarcki B., Arnphion salteri merous crystals filling B., Bathyurus cybele B., R i-1 

cavities; lower meas- beir·ia calcifera B., Leper- urea arenaceous. ditia anna. B. 

Light-yellow and rusty- Scolithus canadensis Bill., Pro- Between 200 and 300 

weathering sandstones tic h n i t e s rnultinotatus feet. 

and conglomerates oc- Owen, P. lineatus Owen, 

casionally present at P. octonota.tus Owen, P. 

the base and along cer- septem-notatus Owen. 

tain divisional planes 

of stratification. I 

1----------~,----

i 
-------------------------------------------

202 INDEX TO THE STRATIGRAPHY OF NORTH A..\f~RICA. 

Wart of] synaptical table of the geological formations about Quebec City, Quebec. 

System. Formation. Character of strata, etc. Characteristic fossils. Thickness. 

-----------1--------------1--

Ordovician. 

Lorraine ....... . 

Utica .......... . 

Trenton ....... . 

Black River .... 

Buff-weathering finegrained magnesian and arenaceous shales and 

limestone bands. 

For the most part darkbrown and buffweathering or black 

bituminousshales and 

thin bands of limestone. 

Thin and evenly bedded 

fine-grained and lightgray compact limestones, with thin shaly 

bands in terstra tified. 

Marine and fossiliferous; used for building 

purposes. 

ilea vier-bedded coarser- grained and in part 

dark-weathering impure semicrystalline 

limestones, fossiliferous. 

Orthograptus quadrimucronatus H., Diplograptus hudsonicus Nicholson, Arnbonychia ( Byssonychia) ra- diata H., Orthodesma parallelum Hall, Trinucleus sp., 

Modiolopsis, and Bellerophon. 

Leptobolus insignis Hall , Schizoc:raniafilosa Hall, S er- pulites dissolutus Bill., Triarthrus becki Green, Asaphus latirnarginatus Hall 

(=A. canadensis Chapman). 

Prasopora selwyni Nicholson, 

Discina pelopea Billings, 

Plectambonites sericea Sowerby, Rafinesquina alternata Conrad (Emmons), 

R. deltoidea Con., Dalmanella testudinaria Dalman, 

Protowarthia cancellata 

Hall, Calymenesenaria,Conrad, Trinucleus concentricus 

Eaton. 

Ambonychia bellistriata Hall, 

Trochoceras halli Foord, 

Trochilina amii J ones,Illm- nus milleri Billings. 

Several hun d r e d feet 

thick. Between 700 

and 900 feet (719 feet, 

Logan). 

Estimated at between 

250 and 300 feet (318 

feet, Logan). 

About 300 feet to 400 

feet. Only a few feet 

observed in various 

outcrops overlying the 

Archean. 

About 75 feet exposed. 

r--------I------------:---------------1---~--------

Quebec........ Hard compact cherty Diplograptus angustifolius Several hundred feet in 

Levis .......... _ 

and calcareous bands, Lapw., Climacograptus bi- thickness. The precise 

dark-brown or black, cornis Hall, Dic:ranograptus figures not yet ascer- more or less thick beds ramosus H~, Dicellograptus tained. 

of bituminous shales, anceps, Paterula amii 

limestone beds, and Schuchert, Corynoides calyevenly bedded con- cularis Nicholson, Shumarglomerates and bands dia granulosa? Billings, 

holding arenaceous Bathyurus caudatus B., 

material. Fossilifer- Aeglina redeviva or n. sp., ous throughout; much Remopleu.n:des? schlothe1:rni 

disturbed and faulted, B., Primitia logani Jones, 

folded, and consider- AparchitesmundulusJones. 

ably altered, slickensided, etc. 

Dark-gray and brown 

and black carbona- ceous shales with limestone beds and con- glomerate bands, also 

light yellow colored 

dolomites. Fossiliferous throughout. The 

light yellowish gray 

limestone often semicrystalline, muchfold-r 

ed and faulted and ofttimes slickensided. 

Tetragraptus quadribrachiatus Hall, T. serra Brongniart ( = T. bryonoides Hall), 

T. bigsbyi H., T. approxirnatus Nicholson, Clonograptusjlexilis Hall, Dichograptus octobrachiatus B., 

Phyllograptus typus Hall, 

Goniograptus selwyni Ami, 

Trigongraptus ensifonnis 

II., Diplograptus dentatus 

Bgt. (=D. pritiniforrnis 

H.), Holograptus arnii 

Lapw. (MS.), Dictyograptus dawsoni (=D. delicatula Dn.), Lingula quebecensis Billings, Elkania desiderata Bill., Serpulites wes- toni n. Fp., Shurnardia graSeveral hundred feet in 

thickness. The precise thickness not as 

yet ascertained (about 

1,400 feet). 

i-----------

nulosa Billings. 

--· ~ --- _1___~----~--
MIDDLE AND UPPER ORDOVICIAN. 203 

[Part o.f1 synaptical table of the geological formations about Quebec City, Quebec-Continued. 

System. I Formation. I Character of strata, etc. Characteristic fossils. I Thickness. 

Red, green, and black 

shales, the latter graptolitic at times, also 

coarse, gritty, evenly 

bedded sandstones Protospongia tetranema DawCambrian. 

and conglomerates oc- son, Lingula quebecensis Probably several thou- Sillery. curring as lenticular Bill. or n. sp., Linnarsso- sand feet in its greatest masses of different nia pretiosa Billings (the development. sizes in the shales. typical fossil), PhyllograpBeds for the most part tus sp. 

tilted a thigh angle and 

folded, faulted, and 

contorted. Fossil or- ganic remains scarce. - [Unconformity.] 

[Pre-Cam brian.] 

The classic descriptions of these Ordovician terranes by Logan 544a will be found 

in his comprehensive monograph of 1863. An interesting discussion of Logan's 

views on the stratigraphy and structure of this region is given by J. W. Dawson.264 

Selwyn726 in 1884 prepared a general description, in which he stated his understanding of the stratigraphy and structure of the region. 

The latest comprehensive and detailed account of the Ordovician of the St. 

Lawrence Valley away from the great cities is by Ells/13d as follows: 

Tho newest rocks of the Cambro-Silurian found in this area are situated to the west of the 

great St. Lawrence and Champlain fault, between it and the River St. Lawrence. They are 

evidently the southwestern extension of the Utica-Lorraine beds which occur along the· river 

on both sides between Quebec and Three Rivers. They are well characterized by fossils, which 

arc found at several places and of which very considerable collections have been made, as at 

St. Hyacinthe and St. Hughes, on the Y amaska River, Chambly Basin, and St. Jean Baptiste 

village (the latter on the River Des Hurons, which joins the Richelieu a short distance above 

Mount St. Hilaire), and at Chambly. Rock exposures are, however, rare throughout this entire 

area. Farther north, on the lower part of the Becancour, opposite Three Rivers, a'small collection of fossils was made in 1888, which showed tho presence of tho typical Lorraine shale formation at this place and served to indicate the apparently uniform extension of these rocks 

throughout this area. 

The rocks of tho Lorraine formation differ somewhat in character from those of Utica. 

They are more sandy in texture, and arc generally of a grayish color or have frequent beds of 

gray sandy shales, which sometimes pass into sandstone layers. The Utica, on the other hand, 

is generally characterized by the presence of brown or brownish-black bituminous shales, with 

occasional hard bands of dolomitic limestone, but gray bods like those of the Lorraine are rarely 

seen. 

* * * * * * * * * 

The valley of the St. Lawrence, from Lake St. Louis almost to Quebec City and for some miles 

on either side of the river, is occupied by strata of the Utica and Lorraine formations, between 

which the line of separation at most points is difficult to ascertain, owing to the great mantle of 

clay so widely distributed throughout this area. This region was one of the first studied by the 

Geological Survey. The strata exposed are nearly horizontal, disturbances being few and due 

to intrusive masses of doleritic matter. The rocks where exposed abound in fossils, and their 

true horizons can therefore be readily determined. The doleritic rocks which intersect these 

strata form mountain masses, sometimes of large extent, which present conspicuous features 

in the otherwise monotonously level landscape. 
204 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

These rocks, both the fossiliferous sediments and the intrusive masses, have been well t, 

described in the earlier reports of the Survey. a In the first of these, viz, that for 1847, the characters of the rocks visible on the line of section between Montreal and Lake Memphremagog are 

so clearly stated that but little remains to be said on that subject. 

As, however, the relations of certain groups, more particularly the crystalline schists and 

the red and green slates and sandstones of the Upper Cambrian (Sillery) were not at that time 

clearly understood, these will call for some remarks on a subsequent page. The general horizontality of the measures, except where this is disturbed by the presence of the intrusive masses 

or dikes, is maintained almost to the vicinity of the great St. Lawrence and Champlain fault, 

which, as already described in a former report, extends from the city of Quebec to the foot of the 

Missisquoi Bay. The fault brings beds of the Trenton formation against the Calciferous and 

Chazy at Phillipsburg and Stanbridge, and its existence is very evident wherever rock exposures 

are visible along its line, but as there is a heavy covering of drift over a considerable portion 

of the country which it traverses, its delineation on the map between exposed points must of 

necessity be largely conjectural. 

This great fault marks one of the important geological features of the district under discussion, but the amount of displacement occasioned thereby is presumably no greater than that 

caused by other heavy faults which traverse the country in a northeast to southwest direction 

and which are seen as far east as Lake Memphremagog. Not only is this entire area greatly 

affected by these faults, but extensive crumplings of strata occurred, which have closely involved 

the rocks of the older or crystalline-schist area with the most recent sediments of the district. 

Narrow areas of the Cambro-Silurian are seen, which contain fossils but are apparently interstratified with the schists; while in some places the formations are so completely overturned that 

the fossiliferous Devonian now underlies the Cambro-Silurian. 

The rocks of the Trenton formation, which underlie the Utica and Hudson River [Normanskill horizon-Ami] (Lorraine) just described, have also a wide distribution. In the earlier 

reports of the Geological Survey b certain portions of these rocks were included in the Upper 

Silurian; these comprise both the black graphitic limestones and associated clay slates. 

Lists of fossils of these Ordovician terranes are given by Ami in appendices to 

Ells's reports on the areas covered by the Pembroke, 26 Perth, 23a Montreal, 14 and 

Grenville 19 sheets. 

In that part of the St. Lawrence Valley which lies east of the St. LawrenceChamplain fault Ordovician rocks occur on both sides of the Sutton Mountain anticline. Omitting the Sillery and Levis (described in Chapter III, pp. 131-134), we 

have here to deal with the limestones and shales of Phillipsburg, Franklin, and Bedford, which range along the northwestern base of Sutton Mountain, and the Magog 

shales, which occur southeast of that anticline in the basin of Lake Memphremagog; 

also with the Quebec formation of Citadel Hill in the city of Quebec and the Ordovician strata which form islands and points along the south shore of the lower St. 

Lawrence. • 

The limestones and shales of Phillipsburg and Bedford occur between the St. 

Lawrence-Champlain thrust fault and Sutton Mountain. The thrust fault strikes 

Lake Champlain at its northeastern extremity, Missisquoi Bay, passing through the 

village of Phillipsburg. East of it occur rocks assigned by Ells 313g to the "Calciferous" and Chazy. Logan's section of the "Calciferous" (divisions A and B) has 

been given in Chapter III (p. 134). The strata are gray to black dolomites and limestones, which according to Ells "shade gradually into the Chazy in the upper part, 

a Logan, W. E., Rept. Progress Geol. Survey Canada, 1847-48, pp. 10-22. Hunt, T. 8., idem, 1858, pp. 171-178. 

Logan, W. E., Geology of Canada, 1863, pp. 205-210. 

b Logan, W. E., Geology of Canada, 1863, p. 434. 
MIDDLE AND UPPER ORDOVICIAN. 205 

so that the point at which the exact line of division between the two formations 

occurs is scarcely indicated." Above division B Logan 544x gives C and D, as quoted 

below, and according to Ami 14b certain fossils (Ecculiomphali) cited from division 

C suggest the "Calciferous." The line between "Calciferous" and Chazy, which 

Ells placed in the upper part of division B but found obscure, may thus possibly 

lie at a higher horizon. 

Logan's section of divisions C and D runs as follows, from the base upward: 

[DiviJion] C. 

1. Black and dark-gray compact limestones, weathering lead-gray, with a few bands of dovegray. The beds are all massive and afford abundance of a few species of Testace::e, the 

whole of which appear to have the peculiarities of being large sized and thick shelled and 

occurring in numerous isolated patches, which vary in diameter from about 3 to 10 feet. 

The fossils are several undescribed species of Murchisonia and Pleurotomaria, Ecculiomphalus canadensis, E. intortus, E. spiralis, several undescribed species of Ophileta, Jfaclurea 

ponderosa, several undescribed species of Orthoceras, and one of Nautilus. Toward the 

base Jfatlurea ponderosa seems to be somewhat smaller than in the upper part of the deposit, 

Feet. 

and toward the top one or two beds appear to be of a partially conglomerate character... 150 

2. Black slates, or possibly thin-bedded bhck limestones, with a few thicker beds toward the 

top; the mass is altogether very imperfectly seen...................................... 170 

[Division] D. 

1. Black limestone conglomerates, composed chiefly of the ruins of the thick-bedded limestones of division C. The inclosed masses vary in size from pieces of an inch in diameter 

to blocks containing 50 and 60 cubic feet and are cemented together by a calcareo-magnesian paste. Of this, however, from the closeness with which the masses are packed together, 

there is but a very small quantity. The limestones are generally close grained and black 

or dark gray in color, but there are mingled with them a few scattered blocks of a lightcolored yellow-weathering dolomite, some of them a foot in diameter. Many of the masses 

of limestone contain fossils, and the species are almost wholly confined to those already 

stated as characterizing the parent beds C l. There appear to be at least two principal 

bands of this conglomerate, each varying in thickness in different parts from about 50 to 

100 feet. There is an interval between them of from 100 to 150 feet, occupied by black 

slates holding rounded masses of limestone, which convert parts of the mass, varying in 

thickness from 10 to 20 feet, into slaty conglomerates. In some parts either the interval 

between the main two bands of conglomerate increases considerably or there is a third 

band with similar slates, intervening between it and the second. The whole is con320 

tained in a thickness of from 250 to ................ ___ ... _ ... ____ ......... __ .......... 300 

2. Black and greenish argillaceous slates, probably interstratified with occasional thin calcareous bands and thin lenticular patches of limestone conglomerate, as well as more important 

bands of yellow-weathering dolomitic slates. The whole is terminated by a band of black 

limestone conglomerate similar in character and thickness (from 50 to 100 feet) to those 

already mentioned and containing llfaclurea ponderosa in one of the few places in which the 

band has been seen. This whole mass of strata is very imperfectly exposed, and much 

uncertainty exists as to its true general character. Its thickness may be from 750 to...... 1,000 

3. Gray and black striped slates, some parts of which are calcareous and weather slightly 

brownish. They are interstratified with occasional thin beds of black limestone, weathering lead-gray, as well as many strong and solid beds of brown-weathering magnesian limestone and brown-weathering dolomitic slates. Some of the latter are marked by an 

abundance of fucoids resembling Buthotrephis jlexuosa of Emmons. Occasional beds of 

sandstone, from 1 to 3 feet in thickness, are met with. About the middle of the mass 

there has in one place been observed a bed of limestone conglomerate from 5 to 10 feet thick, 

and other similar ones may occur in ditierent parts of the vertical thickness .... __ ...... 1,500 

2,800 

In commenting on this section E. 0. Ulrich states that division C is probably 

Beekmantown and division D suggests the Rysedorph conglomerate of the New 

York State Survey reports, although D 1 is probably older. 
------------------------------------

206 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Following this description Logan gives a section on the international boundary 

showing two synclines, modified by thrust faults. 

The equivalents of the above-described strata near Phillipsburg when traced 

south into Vermont are known as the Fort Cassin beds, according to \Vhitfield. 927 

(See K-L 18, pp. 126-127.) Their extension northeastward along the northwest 

side of the Sutton Mountain anticline is minutely discussed by Ells. 313r The fossils 

which have been collected at various times for the Canadian Survey from these 

rocks are reported by Ami l4c under the heading "Phillipsburg series." 

Southeast of Sutton Mountain Ordovician strata again occupy a large part of 

the section at least as far east as the international boundary. Their extent eastward 

in Maine is obscured by their resemblance to the soft slates of the Silurian, by the 

featureless drift and forest covered character of the country, and by intrusions of 

igneous rocks. (See Chapter VII, p. 350.) The strata identified in Canada are 

known as the Magog shales and classed as probably of Trenton and Utica age. 

Ulrich believes the Magog to be pre-Utica. They contain graptolites which are 

described as follows by Lapworth. 522 (See also a paper by Gurley. 388) 

Matrix, soft, thin-bedded and flaking silvery shales, greenish gray in color (originally black), 

apparently altered and spotted by contact metamorphism. 

1. Dicranograptus ramosus Hall. 

2. Diplograptus angustifolius Hall. 

3. Diplograptus foliaceus Murchison (=pristis, Hall). 

4. Diplograptus perexcavatus Lapworth. 

5. Climacograptus bicornis Hall. 

6. Climacograptus ccelatus Lapworth. 

The fossils are all in a most miserable state of preservation, but all the forms named above 

are easily recognizable. These fix the age of the strata as Utica or Marsouin or Normans Kill, 

but somewhat higher in the series than the typical Normans Kill beds. They may safely be 

termed Upper Llandeilo or Lower Bala and placed generally above or about the horizon of the 

Trenton or Utica rocks of the western area. 

The Quebec formation, a distinguished by Ami, 12a consists of dark bituminous 

shales with hard calcareous bands, limestones, and conglomerates, several hundred 

feet thick. The conglomerate forms Citadel Hill and has been described by 

Weston, 887 who quotes Ami as follows: 

Alongside and up Mountain Street a bold cliff of conglomerate occurs, containing large 

Bowlders, embedded in a shaly and calcareo-argillaceous paste with an admixture of qt:artzgrains. 

According to Ami 12•

13 and Ford 345 the fauna by which the Quebec formation is 

characterized comprises Black River and Trenton types and possibly upper Chazy 

forms. 

Not only in the vicinity of Quebec, but thence along the lower St. Lawrence 

(Island of Orleans, St. Joseph de Levis, St. Simon, Riviere de Loup, Bic, etc.) 

there occur Ordovician shales, presumably of several horizons, which locally include 

fragments, bowlders, or pebbles of fossiliferous limestones of earlier Ordovician 

and Cambrian formations. 

Logan 544i describes the rocks in his account of tne ·'Quebec group." Many of 

the occurrences probably represent rather the equivalents of the Sillery and Levis 

than those of the Quebec formation, as restricted by Ami. 

a See table of formations about Quebec, quoted on pp. 202-203. 
MIDDLE AND UPPER ORDOVICIAN. 207 

L 19. CARLETON AND YORK COUNTIES, NEW BRUNSWICK. 

The slate belt that extends from the boundary of Maine northeastward to 

Chaleur Bay is mapped as Cambrian and Ordovician, without distinction of the 

middle and later Ordovician, which, however, occur there. The lithology of the belt, 

according to Bailey, 44 is monotonous, yet the rocks range in age from Cambrian to 

upper Silurian. The sequence is not complete, the base of the Silurian being marked 

by a distinct basal conglomerate con~aining the older Paleozoic rocks as cobbles, 

but it is not known how much of Ordovician time is represented by the unconformity. 

Bailey 46 names the few localities at which the fossils have been found and Ami 25 

describes those from Tete a Gauche River which are of Ordovician age. The latter 

describes "Fossils from the black carbonaceous and graptolitic shales from near the 

railway bridge on the Tete a Gauche River, near Bathurst, Gloucester County, New 

Brunswick," and names them as follows: 

Diplograptus foliaceus Murchison. 

Diplograptus truncatus Lapworth. 

?Lasiograptus sp. indt. 

Climacograptus bicornis Hall. 

Cryptograptus tricornis Carruthers. 

Dicellograptus sextans Hall. 

Dicellograptus anceps Nicholson. 

Orthograptus quadrimucronatus Hall. 

?Didymograptus superstes Hall. 

Leptobolus sp. 

The above assemblage of forms suggests at once an Ordovician fauna belonging to one of 

those zones of graptolites occurring along the St. Lawrence and the Hudson rivers. Similar 

forms from rocks of presumably the same age have also been found in Penobscot County, Maine. a 

These black and at times pyritiferous shales appear to be synchronous or homotaxial with 

the shales of Normans Kill, near Albany, N.Y., of the city of Quebec, of the north shore of the 

Island of Orleans, of the Marsouin River, and of numerous other localities in the Gaspe Peninsula. They find their equivalent in Europe in the Llandeilo rocks of Wales, the Moffatt shales 

of Scotland, and the County Down shales of Ireland. 

M 11. BEAVERFOOT RANGE, CANADIAN ROCKY MOUNTAINS. 

Graptolitic shales are described by McConnell 559ct as occurring between the 

Castle Mountain group (Cambrian and Ordovician) and the "Halysites beds," into 

both of which they appear to graduate in sections along the Canadian Pacific Railway, east of Columbia River. They are hard black fissile slates, 1,500 feet thick, 

which in some sections alternate with thin beds of limestone and here and there, 

near the top, with quartzites and dolomites. Lapworth, reporting on the graptolites, identified Didymograptus sp. nov., allied to Didymograptus euodus Lapworth, 

Glossograptus ciliatus Emmons, G. spinulosus Hall sp., Cryptograptus tricornis Carr 

sp. =C. marcidus Hall sp., Diplograptus angustifolius Hall, D. rugosus Emmons, 

Climatograptus ccelatus Lapworth, and doubtful species of Phyllograptus or Lasiograptus. These forms are referred to "the age of the Utica slate or at any rate to 

the Trenton-Utica fauna of the United States and Canada. The association of forms 

is just such as occurs in the Llandeilo (lower and middle) of Britain, and some forms 

are common to both sides of the Atlantic." 

a Am. Jour. Sci., 3d ser., vol. 22, 1881, p. 434; vol. 40, 1890, p. 153. 
208 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The lithologic and faunal similarities of this terrane to those of Dease River, in 

latitude 60° north, and of the Alaska Range indicates the persistence of like 

geographic conditions along the trend of the Cordillera in middle and late Ordovician 

time. Ulrich says: 

The graptolite faunas in the Cordill~ran basins west of the Rockies from Nevada to Alaska 

seem to belong to nearly the same horizon. Its age appears to be intermediate between the 

Levis-Tetragraptus zone and the Normans Kill of the Atlantic side. 

M 19-20. GASPE PENINSULA. 

Along the south shore of the St. Lawrence, according to Logan/44 i are black 

shales and gray calcareous sandstones of middle and possibly later Ordovician age. 

They have been described by Dawson 267 as the Marsouin River formation, and the 

horizon of the graptolitic fauna which they contain is discussed by Lap worth, 521 

who states, under the heading 11 Griffin Point or Marsouin River zone:" 

The most characteristic forms from the zone areDidymograptus sagittarius (Hall non Hisinger). 

Ccenograptus gracilis Hall. 

Dicellograptus sextans Hall. 

Lasiograptus mucronatus Hall. 

Climacograptus antiquus Lapworth. 

Diplograptus whitfieldi Hall. 

So far as known, these are peculiar to this zone, and the presence of a single one of these 

species is sufficient to settle the age of the rock in Great Britain, and in all likelihood in America. 

With these peculiar forms, however, are associated others which have a much longer vertical 

range and unite this zone to the one which follows it in order of time. These species of long 

range areDicranograptus ramosus Hall. 

Glossograptus ciliatus Emmons. 

Diplograptus putillus Hall. 

Climacograptus scharenbergi Lapworth. 

They all pass up into the British zone next above the Ccenograptus zone, together with 

the following species, which range up through at least three complete zones: 

Diplograptus foliaceus Murchison. 

Climacograptus bicornis Hall. 

This special Marsouin zone, now under consideration, has long been recognized by geologists 

upon the continent of America. Its fossils were described many years ago by Prof. J. Hall, in 

his "Paleontology of New York," from the dark shales of Normans Kill, near Albany, in the 

valley of the Hudson River. Hall also referred to the detedion of the Normans Kill fossils 

on Marsouin River by Sir William Logan and the Canadian Survey; but the discovery of the 

existence of rocks containing the Normans Kill fossils as far down as Griffin Cove and between 

the Marsouin and Quebec, as demonstrated by the present collection, is wholly due to those 

officers of the Geological Survey of Canada who have studied the district since the retirement 

of Sir W. Logan. There can be no question of the general identity of this Griffin Cove rock 

and the Marsouin Ccenograptus zone with that of the Normans Kill of the Hudson River valley. 

Lapworth further divides the fauna, which he calls the Trentonian, Marsouin 

River, or Normans Kill fauna, into two subfaunas, namely: 

Subfauna A, the Ccenograptus zone of Griffin Cove and the Marsouin River, answering to 

the Middle Llandeilo beds of Great Britain to the Glenkiln beds of Scotland, etc. 

Subfauna B, the Cove Fields and Orleans subfauna, apparently destitute of Omnograptus 

gracilis and answering to the highest Llandeilo or Lowest Caradoc beds of England. 
MIDDLE AND UPPER ORDOVICIAN. 209 

The last of these subfaunas shows evidence of a transition into the Utica-Lorraine graptolitic fauna of the Mohawk Valley, New York, and of Lake St. John, Canada. 

Ulrich states that the fauna may be called Trentonian only if that term is used 

as a synonym of Mohawkian and that the so-called Normans Kill is as old as the 

Black River. 

The stratigraphic succession and structural relations are involved in the overthrusts of the sedimentary strata, and the distribution is probably not so simple as 

it appears even on the detailed maps. The horizon of the Marsouin River formation 

is repeatedly referred to by Ells 310a, 311b, 313e in tracing the sweep of Ordovician 

strata through the "Eastern Townships" of Quebec, the similarity of the rocks and 

graptolites indicating the continuity of the zone of deposition as far as the locality 

of the Magog shales on Lake Memphremagog. In Vermont and New Hampshire 

the terrane is probably represented in the metamorphosed Paleozoic rocks. 

M 20. MINGAN AND ANTICOSTI ISLANDS. 

Ordovician strata are exposed along the north coast of Anticosti Island, dipping 

gently southward under the Anticosti group (Silurian). The lowest strata seen 

at t~e base of the cliffs are assigned by Logan to the "Hudson River" [Richmond] 

formation. Farther north, across the strait, the Mingan Islands consist of rocks 

referred to the "Calciferous" (Beekmantown) and Chazy, with possibly part of 

the "Birdseye" (Lowville) and Black River formations. The closely adjacent 

coast of Quebec is "Laurentian." Thus it appears that the middle Ordovician 

strata in this region overlap the earlier Paleozoic (pre-Beekmantown) rocks and 

extend from the north margin of the Gulf of St. Lawrence southward beneath its 

waters to Anticosti, where the overlying upper Ordovician and Silurian are exposed. 

Regarding the Chazy of the Mingan Islands, Logan 544b says: 

At the Mingan Islands the Chazy formation bears lithological characters somewhat different 

from those which have been given above. The lowest part seen of the deposit occurs in the 

bay above Clear Water Point, and the following is a section of the strata in ascending order: 

Feet. 

Reddish cream-colored compact limestone with a conchoidal fracture, weathering pale yellow__ 1 

Greenish and brownish-black shale ........................................... ___ . _ .. ____ .... 1 

Reddish cream-colored limestone as before, in beds of from 1 to 2 inches to a foot, interstratified 

with greenish shale in beds of about the same thickness ....................... _ . ___________ . . 28 

Greenish shale with Rhynchonella oriental is (which is a variety of R. plena) in great abundance.. 3 

Gray granular limestone with false bedding, holding comminuted fragments of encrinites and 

other organic remains, including Bolboporites americanus, Rhynchonella orientalis, a few of 

Camerella longirostrata, and other species................................................... 13 

Gray nodular limestone with Columnaria parva, Stenopora adherens, Fenestella incepta, Orthis 

piger, Strophomena incrassata, Ctenodonta nasuta, Nautilus jason, Amphion canadensis, Harpes 

antiquatus, Illamus globosus ...................................................... _........ 20 

Gray magnesian limestone, with Murchisonia aspera, Maclurea atlantica, Orthoceras multicameratum, 

0. bilineatum, 0. natator, 0. mara, 0. antenor, 0. minganese, 0. shumardi, Illamus bayfieldi, and 

other fossils........................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 

78 

Apparently above these strata but not in immediate St;quence Logan lists gray 

and yellow limestone and green shale in thin beds to a thickness of 171 feet, almost 

without fossils, which he, however, regards as Chazy and possibly not including 

the top of that terrane. Ulrich suggests that these strata may be Lowville. Above 

48011°--12----14 
210 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

them occurs a yellowish-white pure limestone, 30 feet thick, carrying _l\,1aclurea 

logani, which Logan 5440 refers to the "Birdseye" (Lowville) and Black River. 

A detailed section of the strata exposed above the beach at the west end of 

Anticosti is given by Logan/44r with much refinement of distinction among the 

successive beds and lists of fossils found in each. Limestones and argillaceous 

shales in thin layers make up most of the thickness noted (959 feet). Gray limestone, greenish shale, and a few layers of limestone conglomerate alternate in the 

lower 229 feet; bluish and reddish-gray limestone separated by thin greenish 

shale partings and conglomerates succeed with slight variations throughout the 

upper 730 feet. 

The Ordovician here passes without notable lithologic change or break into the 

Silurian, and a number of fossils are common to strata above a·nd below the assumed 

plane of division, yet numerically the extinction of species is more marked than 

their persistence. Billings 82 states the facts as follows: 

In the Lower Silurian rocks of Anticosti there have been collected 121 species of fossils, 

of which the proportionally large number of 85 have been described in this and other publications of the Survey as new forms. The remaining 36 are mostly of the common and widely 

distributed species of the Lower Silurian of Canada West, New York, and other countries. 

They are the following: 

Stenopora fibrosa. 

S. mammulata. 

S. papillata. 

S. explanata. 

Halysites catenulatus. 

Lingula quadrata. 

Trematis ottawaensis. 

Strophomena imbrex. 

S. subtenta. 

S. planumbona. 

S. alternata. 

Leptoona sericea. 

Orthis testudinaria. 

0. subquadrata. 

O.lynx. 

Rhynchonella capax. 

R. recurvirostra. 

Ambonychia radiata. 

Subulites richardsoni. 

Trochonema umnilicata. 

Pleurotomaria americana. 

P. helena. 

P. subconica. 

Murchisonia gracilis. 

M. ventricosa. 

Bellerophon acuta. 

B. bilobatus. 

Pterotheca transversa. 

Oncoceras constrictum. 

Asaphus platycephalus. 

A. megistos. 

Dalmanites callicephalus. 

Cheirurus pleurexanthemus. 

Harpes ottawaensis. 

Calymene blumenbachi. 

Leperditia canadensis. 

There are no species which are exclusively Upper Silurian; the aspect of the whole fauna 

is eminently Lower Silurian. The rocks are very fossiliferous throughout, but on approaching 

the dividing line between this group and division 1 of the Anticosti group, which immediately 

succeeds, not less than 80 out of the 121 species suddenly disappear and are seen no more. 

It is evident, therefore, that there is here a break of considerable importance, probably in some 

way connected with the great gap that occurs between the Hudson River and Clinton formations in Canada West and New York. Of the 41 species that pass this break, 30 appear to 

have become extinct during the period of division 1; at least they have not been detected in 

division 2. Of the remaining 11 species, 7 pass upward into division 3 and 6 into division 4. 

Ulrich comments to the effect that according to present understanding of the 

Anticosti problem, none of the beds in Logan's section is older than Richmond. 
MIDDLE AND UPPER ORDOVICIAN. 211 

M 21. NEWFOUNDLAND, NORTHERN PENINSULA. 

In 1863 Logan 5441 stated the observed sections of the strata along the western 

and northern coas.ts of the great northern peninsula of Newfoundland and distinguished divisions which he numbered from 1 to 16 or A to Q. Some of the 

fossils listed by him are grouped in associations which indicate that there was 

confusion, either because they became mixed in collecting or through the occurrence 

of fossils in conglomerate pebbles or on account of the presence of thrust faults; 

but no other systematic discussions than those by Logan and Billings are available. 

Divisions A to H inclusive have been discussed in Chapter III (pp. 149-153). Divisions I, K, L, and M are possibly equivalent to the upper Chazy, Black River, and 

Trenton of the epicontinental sea that spread to New York, though many typical 

species of those faunas are absent and Billings was in doubt. Divisions N, 0, and 

P, described by Logan as higher in the series, are classed by Billings as being faunally 

related to the Sillery and Levis and apparently belong lower in the Ordovician. 

Ulrich says (comments on manuscript) : 

Respecting the Newfoundland section I fail to see reasons for regarding division I and 

possibly up to and including division N as above the Beekmantown. Part of this series is almost 

certainly of Beekmantown age, but other parts seem no less certainly of later age. The 

Levis graptolites in division N are, I am convinced, of early Beekmantown age. Not to enter 

into detail, it may suffice to say that an analysis of the faunas suggests ages ranging from early 

Beekmantown to late Black River. As the oldest of these faunas occurs in the uppermost 

division (N), the succession of the others is not regular; the evidence indicates misinterpretation of the structure, with overthrusting and overturn instead of the regular and unbroken 

sequence described by Logan. 

Logan's section of divisions I, K, L, and M is as follows: 

I. 

Fe:t. 1. Light yellowish gray mottled and subcrystalline magnesian limestone, with geodes of calc 

spar. The limestone is divi<'led into beds of from 6 inches to 1 foot and shows occasional 

fossils, the only recognizable species being Maclurea matutina............................. 65 

2. Light yellowish gray mottled magnesian limestone as before, interstratified with grayishblack limestone in beds of from 3 inches to 1 foot. The magnesian beds contain Maclurea 

matutina . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 

K. 

1. Light-gray, subcrystalline limestone, with grayish-black limestone, both in beds of from 2 

to 6 inches, and associated with a few bands of grayish-white dolomite, from 6 to 9 inches 

thick, the whole interstratified at intervals of from 10 to 20 feet with black and grayishgreen shales. The light-gray limestone and whitish dolomite are fossiliferous, containing 

135 

the genera Orthis, Ctenodonta, Ophileta, Maclurea, Pleurotomaria, Murchisonia, and Orthoceras. The described species are Orthis electra, Maclurea matutina, and Orthoceras piscator. 100 

L. 

1. Grayish-white dolomite and greenish-gray compact limestone, both in beds of from 2 to 6 

inches thick, interstratified with about 3 per cent of black and grayish-green shale, all 

without observed fossils............................................................... 104 

2. Light reddish-gray magnesian limestone, in beds varying from 15 inches to 2 feet in thickness. The rock breaks from the cliff in which it is exposed, in rectangular blocks of several 

feet long and wide, and would make an excellent building stone. No fossils were observed. 16 

3. Brownish-gray hard limestone, in beds of from 6 inches to 2 feet; fossils occur at the base, 

among which are the genera Stenopora, Orthis, Murchisonia, Asaphus, and Leperditia.... 65 

4. Reddish-gray magnesian limestone, in beds of from 2 to 6 inches, without observed fossils... 6 

191 
212 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

M. 

l. Brownish-gray limestone, in beds varying in thickness from 6 inches to 6 or 7 feet, interstratified at distant intervals with reddish-gray dolomite in beds of from 3 to 9 inches, 

which constitute 1 or 2 per cent of the whole. Both the limestone and the dolomite are 

fossiliferous throughout; the organic forms, however, are obscure in the whole, with the 

exception of about a foot of the limestone at the base and 6 feet at the top, including a bed 

of the dolomite, in the whole of which the fossils are silicified. The genera at the base are 

Eospongia, Orthis, Ophileta, Pleurotomaria, Murchisonia, Orthoceras, and Asaphus. At 

the top the same genera occur, but there is a greater number of species, and it is probable 

Feet. 

that the fossils of these two parts represent those of the whole mass...................... 350 

In the fossiliferous beds of divisions K and L, and in part 1 of M, there are several species 

of each genus, and the same species seem to range through the whole. The described 

species are Orthis electra, Maclurea matutina, and Orthoceras piscator; but the chief part of 

the species of the remaining gastropods and cephalopods are so closely allied to some of 

the common forms of the Trenton group that it scarcely appears doubtful that they are the 

same. The most striking resemblances are to Orthoceras bigsbyi and 0. allumettense of the 

Birdseye and Black River, and to Murchisonia gracilis, M. bellicincta, and M. perangulata 

of the Trenton formation. 

2. Bluish-gray limestone, in beds varying from 6 inches to 10 feet in thickness, the thicker 

beds being made up of layers of 1 or 2 inches, distinguishable in section by slight differences in color but without any tendency to separate. Some of the beds are nodular and 

crumble under atmospheric influences. Fossils are abundant in all the beds but are not 

readily separated. ']l>hey .consist chiefly of Stenopora fibrosa, Orthis like 0. platys, Rhynchonella allied to R. plena, Camerella varians, new species of Maclurea, and Orthoceras; 

with 0. piscator, 0. allumettense?, 0. bigsbyi?, Amphion, Ampyx, Asaphus, Illrenus, and 

Leperdi tia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308 

1,349 

Commenting on the above section, Ulrich suggests upper Beekmantown for 

division I and middle Chazy for division M. 

Billings 81a discusses in the following terms the taxonomic relations of the Ordovician strata of Newfoundland which constitute Logan's divisions I, K, L, and M.: 

These four divisions consist of 235 feet of magnesian limestones at the base, above which 

we have 844 feet of light bluish-gray limestones, making in all a thickness of 1,084 feet. Only 

37 species of fossils have been collected in this series of beds; and of these, nine specie& are 

found in division H below, while ten of them pass Upward into division N next above. Three. 

of the species (Stromatopora compacta, Orthoceras allumettense, and Asaphus canalis) occur in 

Canada, the first two in the Chazy and Black River and the last in the Calciferous and Chazy. 

The following are closely allied to Black River and Trenton species: 

Ctenodonta angela, allied to C. contracta, B. R. 

Subulites daphne, allied to S. parvulus, B. R. 

Murchisonia simulatrix, allied toM. gracilis, B. R. and Tr. 

Murchisonia cicelia, allied toM. perangulata, B. R. 

Murchisonia sororcula, allied toM. perangulata, B. R. 

Murchisonia augustina, allied toM. bellicincta, Tr. 

Orthoceras h>esitans, allied to 0. bigsbyi, B. R. 

The occurrence of great numbers of individuals of these species in a silicified condition 

and weathered out in bold relief gives to the slabs of limestone an aspect so remarkablylike 

that of the well-known specimens from Pauquettes Rapids that at first sight one might be 

well led to say, This is surely the Black River limestone. But on careful comparison of perfect 

specimens it is seen that notwithstanding the resemblance none of the species are strictly identical. All present such differences that after a study of collections from both localities they can 

be separated if mixed up together without their labels. Even 0. allumettense, which I have 

identified, differs by being much larger than any specimens that have been seen in the original 

localities. · 
MIDDLE AND UPPER ORDOVICIAN. 213 

If the succession were the same here as it is in Canada and New York, WP ought to have 

the Chazy formation represented in these four divisions. But no one acquainted with the peculiar and strongly featured fauna of that formation could recognize it in this collection. Three 

of the species are, indeed, Chazy fossils, but then they are not characteristic forms. The typical 

and leading species which always go together in great numbers and in one compact army, as it 

were, ~n every exposnre of the true Chazy, are totally absent.a 

The Lamellibranchiata, Gastropoda, an·d Cephalopoda of these beds have, so far as the 

genera Ctenodonta, Subulites, Plenrotomaria, and Orthoceras are concerned, an aspect very 

like that presented by the same genera in the Black River and Trenton formation. But species similar to most of those above compared have a great range and are found in all the different grotlps of rocks up to the Devonian. Their occtlrrence here is not, in my opinion, sufficient 

to counterbalance the negative fact that (excepting those in question) not a vestige of any one 

of the species of the vast fauna of the Black River and Trenton has been detected. Tetradium 

fibratum, Columnaria alveolata, Lept;:ena sericea, Strophomera alternata, Orthis testudinaria, 

Calymene blumenbachi, and Asaphus platycephalus are sure to be found in every collection of 

any considerable extent from these two formations. If they occurred here as abundantly and 

persistently as they do in Canada and New York, it would be difficnlt to give any reason why 

these four divisions should not be regarded as the equivalents of the Black River and Trenton. 

But not one fragment of anything which could by any possibility be referred to any one of 

these species can be seen in this collection. A piece of red limestone was found at Bay St. Paul 

which is full of L. sericea, but it was a loose and worn fragment, lithologically differed from 

any of the strata in question. Judging from this specimen I should say that the Trenton may 

possibly occur somewhere near, but we can not refer, on any paleontological ground, the series 

of strata constituting divisions I, K, L, M to that formation. 

Following Logan's section 544z we note in ascending order the divisions N, 0, P, 

and Q, occurring apparently above the divisions I, K, L, and M. The numbers 13, 

14, 15, and 16 are those by which he first designated the separate divisions. 

[N.] 

l. Blackish-gray nodular fossiliferous limestone, in beds of from l to 3 inches thick, becoming 

bituminous toward the top. The fossils are Orthis, Strophomena, Rhynchonella allied to 

Feet. 

R. plena, a new species of Camerella, Orthoceras piscator, 0. allumettense?, Amphion, Asaphus, 

Holometopus angelini, IllEenus, and Leperditia......................................... 81 

2. Black bituminous limestones, in beds of from 1 to 3 inches thick, interstratified with fine 

brittle black bituminous shale in layers varying from a quarter of an inch to 3 inches. 

The prevailing fossils are Stenoporafibrosa, Lingula allied to L. philomela, Orthis, Strophomena, Rhynchonella allied toR. plena, a new species of Camerella, with C. varians, Orthoceras, Agnostus, Amphion, Ampyx, Asaphus, Endymion meeki, Holometopus angelini, 

IllEenus, Nileus scrutator, and Leperditia................................................ 174 

3. Black bituminous shale, with Graptolithus, Lingula, Orthoceras, and Paradoxides or Olenellus... ............................................................................ 22 

[0.] 

-14. Gray calcareous sandstones, generally fine grained; in beds of from 6 inches to 2 feet, interstratified with black and greenish shales, which predominate toward the top. The 

sandstones are sometimes of a ,conglomerate character and include pebbles of white 

quartz and black limestone, varying in diameter from the eighth of an inch to 2 inches, 

with small fragments of red and black jasper and flat pieces of black and green shale. 

277 

The sandstones and the shales are aggregated in masses yarying from 6 up to 60 feet in 

thickness. ~o fossils have been met with in this rock................................. 700 

a Ulrich takes exception to the statement of Billings in regard to the Chazy and says that he (Billings) "was 

not well acquainted with the lower and middle Chazy faunas. He knew the upper very well, but this is Yery different from the two lower faunas. These middle and lower Chazy faunas contain species such as mentioned by Billings, 

greatly like 'Black River' forms. (See Raymond's papers.)" 
214 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

[P.] 

15. Gray, drab, and whitish limestone conglomerates, interstratified in the lower part, with 

bands of black and greenish shale from 40 to 100 feet thick; and associated with black 

limestone holding layers of black chert from 1 to 3 inches thick. Graptolites occur in 

the black limestones and fragments of trilobites in the chert. In the upper part the conglomerate is more massive, great thicknesses showing no trace of bedding. The inclosed 

pebbles, bowlders, and fragments of limestone range in weight from 1 ounce to a ton and 

in color from white through various shades of drab and gray to black. Associated with 

the masses of limestone are occasionally others of gray calcareous sandstone, specimens 

of which can not be distinguished from those of the sandstone (14) which is beneath. 

Some masses, which are of the same character as smaller inclosed blocks, are 200 feet long 

by 30 feet thick. It is difficult to decide whether these are sediments deposited in the 

bed or inclosed transported masses, notwithstanding that they are divided into beds 

with partings of black shale. Some of the conglomerate beds are filled with pebbles of 

black chert. Near to the top, patches of several hundred yards, in the supposed direction of the strike but without observed bedding, consist of light reddish-gray pure 

limestone, in part highly crystalline, abounding with convoluted shells and other fossils. 

The genera found in these conglomerates and their interstratified masses are Graptolithus, 

Orthis, Rhynchonella, Camerella, Ophileta, Maclurea, Orthoceras, Asaphus, Illoonus, 

Amphion, Bathyurus, Holometopus, Nileus, Ampyx, Agnostus, Endymion, and several 

trilobites of undetermined genera. The determined species are Graptolithus headi, Camerella caleijera, Maclurea pondero.m, Bathyurus saffordi, llolometopus angelini, Endymion 

Feet. 

meeki, and Nileus scrutator ........................................................ _ 700 

[Q.] 

16 •. Greenish sandstones of a chloritic aspect, made up apparently of fine grains of quartz and 

feldspar, with a few scales of mica, mixed with greenish argillaceous matter. Some 

beds are of a conglomerate character, the pebbles consisting of white quartz and reddish feldspar, varying from the sixteenth of an inch to an inch in diameter; the quartz 

pebbles are somewhat larger and much more numerous than those of feldspar. They 

are accompanied by occasional pebbles of red jasper, and by flat pieces of green shale. 

In some beds the masses inclosed consist of gray limestone. The finer beds are aggregated in thicknesses of several hundred feet, and the conglomerates are from 10 to 20 

feet. These fine and coarse sandstones are interstratified with several bands of red shale 

from 10 to 20 feet thick; and one of 60 feet consists of red shale interstratified with green 

layers. The thickness of the whole was not measured, but it is supposed to be not much 

under . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,000 

In his descriptions Logan included division N with divisions I, K, L, and M, in 

a major group, but Billings 81b classed N with 0 and P and commented on the 

taxonomic relations as follows: 

The rocks of these divisions, in ascending order, consist of 277 feet of black bituminous 

limestone, with some black shales, very fossiliferous; next 700 feet of sandstones, in which no 

fossils were collected or observed; and at the summit 700 feet of black shales, holding gray 

and white limestone conglomerates, abounding in fossils, although there are not a great many 

species. There appear to be in this series of strata two formations, distinguishable from each 

other both by lithological and paleontological characters. The fi:rst includes the black bituminous limestones and shales, forming the upper 277 feet at Table Head, and those of Pistolet 

Bay and 4 miles northeast from Portland Creek. The rocks at the latter locality appear to lie 

above the 700 feet of sandstone constituting division 0 and are therefore in the foregoing 

descriptions of species referred to division P. Taking these three localities to be on the same 

or nearly the same horizon, we have from them, in addition to a few not yet described, the 

following 48 species: 

Lingula nympha. 

Lingula iole. 

Lingula cyane. 

Acrotreta gemma. 

Orthis delicatula. 

* Strophomena aurora. 

Strophomena imbecilis. 

Strophomena decipiens (?). 

Camerella parva. 

Camerella varians. * 

216 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

C.H. C.E. 

Bathyurus saffordi.................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X X 

Bathyurellus nitidus.... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X 

Bathyurellus formosus................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X X 

Bathyurellus fraternus........................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X 

Nileus affinis ....... __ . _____ ....... __ ... _ ..... __ ..... ___ . --.--....................... X X 

Illrenus tumidifrons ___________________ . _ ..... ______ . __ .......... __ ..... __ ... __ ........ X 

Illrenus arcuatus. ____ ...... _ ......... __ . __ ...... __ . _. __ .............................. . X 

Illrenus consobrinus .. ___ . ___ .. ______ . _. _ .. _. _. _ .. ___ . _............................... X 

* Holometopus angelini. ... __ ........ _____ ..... _ ... _ . __ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X X 

Lichas jukesii. ... ___ ... _____ .... _ .. ______ ......... ____ ............................... X X 

Cheirurus vulcan us .. _ .. __ ....... _ . ___ .. _ ...... __ . ____ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X X 

Cheirurus mere uri us .. ______ .... ______ .... _ . _______ .. _ .. _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . X X 

Cheirurus prolific us (Chazy) ........... _ .. _ ..... ___ . ____ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X X 

* Am phi on barrand ei. ... __ ...... ____ .. _ . __ . _ . __ . ____ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X 

Amphion julius ...... ____ .. _ ..... __ . __ . _ . _______ . _____ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X 

In the above list those found at Cow Head are placed in the column C. H. and those which 

occur in Canada East (as well as Cow Head) C. E. The seven species of graptolites, with 

Lingula quebecensis, occur only in the black slates; all the others in the gray and white limestones. 

The three species with an asterisk before them are found in the next group of strata below. 

No one could compare the collections from Cow Head with those of Point Levis and Phillipsburgh without some feeling of astonishment that in localities nearly a thousand miles distant 

from each other there should be such a perfect identity not only in the fossils but also in the 

character of the rock. The specimens, if mixed together without their labels, could never be 

separated. Only a small collection was made at Cow Head, and there can scarcely be a doubt 

that further examination will bring to light a greater number of species common to the two 

countries. 

This fauna, although upon the whole specifically distinct from the one next below, consists 

of the same types of trilobites, with the exception of Bathyurus cordai and B. conicus, which are 

Calciferous species, as is also the brachiopod Gamerella calcifera. There are two species, Amphion 

sol, and Endymionia meeki, which are found in division N, in Newfoundland, and not at Cow 

Head, but they occur in the limestones of Point Levis, which are of the same age as those of 

Cow Head. There are thus five common species, instead of three, as would appear b_y the 

above list. 

From Cow Head, Point Levis, St. Antoine, Stanbridge, Bedford, and Phillipsburgh we have 

in all219 described species. Of these, the 51 species of graptolites described by Prof. Hall, and 

also Lingula quebecensis, L. irene, Obolella desiderata, and Shumardia granulosa have been found 

only in the slates and thin-bedded limestones interstratified in the slates. The other 162 species 

occur in the white and gray conglomerate limestones. That the slates and these peculiar 

limestones belong to the same group is proved by their occurring together in widely separated 

localities, although as yet we are unable to show that any of the species are common to both. 

At Cow Head G. headi was found in a loose piece of gray limestone, but it is not quite certain 

that the specimen belongs to the conglomerates. 

The evidence that the rocks at Cow Head in Newfoundland are of the same age as those of 

the Levis formation in Canada East amounts to this: (1) They are precisely the same in lithological characters and (2) out of the 34 species collected at Cow Head 23 are perfectly identical 

with those collected at Point Levis, Bedford, Phillipsburgh, and other typical localities of the 

formation. There is, however, in Newfoundland an important series of strata, consisting of all 

the divisions from I to 0 inclusive, having a thickness of 2,061 feet, lying below the Levis 

formation and above the Calciferous, wl~ich has not been recognized in Canada. It thus appears 

that the Levis formation not only lies above the Calciferous but more than 2,000 feet above it. 

Yet it holds a large number of trilobites of the Potsdam type and several species, such as Lingula 

mantelli, Gamerella calcifera, Bathyurus cordai, B. conicus, and Asaphus canal-is, which certainly 

do occur in the Calciferous. 

In the foregoing general catalogue (ante, pp. 366-370) there are 62 species placed in divisionP. 

But if we exclude from that division all the species except those collected at Cow Head, only 

those on the list on page 375 properly belong to it. The others should be placed in division N. 
MIDDLE .AND UPPER ORDOVICIAN. 217 

Ulrich (personal communication) comments as follows on the section: 

These Ordovician fossils are in the conglomerate bowlders here as at Point Levis. The 

graptolitic shale itself is the Levis thrust inland over the Chazy. The remainder of the section 

ISm question. It may be in part Chazy or all post-Chazy, with persisting Chazy species, as in 

the Liberty Hall limestone of Virginia. 

M-N 14. LAKE WINNIPEG DISTRICT, MANITOBA. 

Dowling 290 gives the following table of divisions of the later Ordovician in the 

Lake Winnipeg region and compares them with the formations known in Minnesota. 

Formations in Minnesota. Formations in Manitoba. 

Hudson 

River or Richmond group. Stony Mountain. Cincin- Limestones and shales. 

nati pe- Utica group. Utica(?). 

riod. 

Maclurea beds. Upper Mottled limestone. 

--· 

Trenton group. Fusispira and N ematopora beds. Trenton. Cat Head limestone. 

------

Clitambonites beds. Lower Mottled limestone . .,j 

.s 

Fucoid and Phyllopo- .... Winnipeg sandstone and <l) 

Black River(?). rina beds. [a] p.. 

shales. >=I 

0 

...- -----· Trenton >=I 

period. Black River group. (!) 

Ctenodonta beds. ... 

E-< 

---·· 

Rhinidictya bed. 

S tictoporella bed. 

Stones River group. Yanuxemia bed. 

"Lower Buff." 

Chazy formation. St. Peter sandstone. 

a This is the widely spreading zone so well displayed at Silliman Mountain, Baffin Land. The Winnipeg sandstone 

of Manitoba is probably at the same horizon but may be in part St. Peter.-Comment by E. 0. Ulrich on manuscript. 

Dowling describes the several divisions of the Ordovician as follows: 

The basal beds of the Cambro-Silurian [Ordovician] of Manitoba consist of a series of soft 

friable sandstones, shaly in the upper part but generally similar to those found in Minnesota 

beneath the Trenton limestone. Very few fossils have been obtained, and those from the upper 

part only, denoting merely lower beds of the Trenton. * * * The fossils give no definite 

information as to the age of the beds but suggest a passage from Black River to Trenton. * * * 

In eastern Canada and New York State the Black River is usually a thick-bedded limestone, 

but in Minnesota it is composed mainly of greenish shales, so that the shales below the limestone 

in the borings at Rosenfeld and Selkirk may be taken as the passage beds from the Black River. 

These are represented on Lake 'Winnipeg by shaly bands in the upper part of the section. The 

sandstone below, being in the nature of a shore deposit, though occupying a position nearly 
218 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

similar to the St. Peter sandstone of Minnesota, can not be regarded as definitely of the same 

age, since no evidence of Chazy fossils has been found in it. 

The thickness of pure sandstone in the Lake Winnipeg basin is apparently much less than 

to the south. The several sections give varying thicknesses [40-100 feet], owing to the uneven 

nature of the floor on which it was deposited. * * * 

The Lower Mottled limestone is the lowest member of the limestone series and rests directly 

on the basal sandstones and shales. These limestones form the principal part of the sections at 

Grindstone Point, Bull Head, and Dog Head, and on the islands north to Berens Island. The 

combined section given by these several exposures amounts to a thickness of about 70 feet. 

The lowest beds are those seen at Deer Island and Grindstone Point capping the sandstone. 

Immediately above are the beds occurring at Dog Head, followed by the upper part of the Black 

Bear Island exposure. Those on Tamarack and Jack Head islands are evidently higher but 

belong to the same series and form, together with those mentioned above, the following descending section: 

Feet. 

1. Hard mottled limestone, dark yellow, with brownish-yellow spots, breaking up into lumpy 

fragments not wearing discoidal on the beach but irregular. A few pieces from top beds are 

not so mottled and break smoothly (probably base of Cat Head limestone)................ 15 

Exposure on west side of Jack Head Island. 

2. Thin-bedded, mottled buff and grayish-white limestone, weathering ashy-white, in which are 

many large cephalopods: Orthoceras, Sactoceras, Poterioceras, Oncoceras and Cyrtoceras, 

while specimens of Maclurea manitobensis and Receptaculites oweni are abundant. . . . . . . . . . 15 

Eleven feet of these beds are .exposed on Little Tamarack Island and similar beds are exposed 

on Little Black Island near Berens Island. 

3. Mottled limestone, buff-colored but weathering lighter, in rather thicker beds than above 

and not so rich in fossils............................................................... 10 

These form the upper part of cliff on Black Bear Island. 

4. Thin beds of similar rock, rich in fossil remains............................................ 20 

This band occupies the lower portion of the exposures on Black Bear Island, on Snake Island, 

and Dog Head or Whiteway Point and the upper part of the cliffs of Bull Head and intervening exposures. 

5. Darker mottled impure limestone, where not woothered, almost blue on fracture; fractures 

into thin flags with surfaces covered with fucoidal markings. The lower beds are of very 

earthy limestone resting on the sandstone of the basal series............................ 10 

70 

* * * * * * * * * 

The Cat Head limestone, the central portion of the limestone series, is best developed at 

the prominent point on the west side of Kinwow Bay, called Cat Head. The beds are of a finegrained, evenly colored yellow dolomitic limestone, with numerous concretions of dark-colored 

chert, filling cavities apparently left by the decay of corals. These beds are seen in the high 

cliff at Cat Head and along the shore to Lynx Bay. At the western end of the section, 3 miles 

west of Cat Head, the cherty concretions attain large dimensions. Several are over a foot in 

length, and one measured 2 feet by 10 inches. The lower beds are fine grained, resembling 

lithographic stone, and are very rich in fossil remains. The total thickness as observed on the 

lake is 68 feet. This includes the top beds of Cat Head and Outer Sturgeon Island, which are 

similar in color but coarser in texture, becoming finally crystalline. The section is made up 

as follows: 

Feet. 

1. liard, flinty, coarse-grained limestone (Sturgeon Island)................................... 10 

2. Yellow granular limestone, weathering roughly and slightly honeycombed (Cat Head)....... 8 

3. Similar coarse-grained, weathering dark-yellow, with fucoid-like markings, and very much 

honeycombed (Cat Head).............................................................. 3 

4. Yell ow limestone with fucoidal markings similar to No. 2 (Cat Head)........................ 10 

5. Fine-grained yellow rock with numerous ashy-colored spots scattered over the whole face of 

the exposure, from the weathering of small impure flinty concretions (Cat Head)........... 27 

6. Fine-grained yellow limestone, rich in fossil remains, with numerous large concretions of dark 

cherty material (Cat Head, McBeth Point, and Inmost Island)........................... 10 

68 

* * * * * * * * * 
MIDDLE AND UPPER ORDOVICIAN. 219 

The two lower series-the Cat Head and the Lower Mottled-are not of any great thickness, but are in the district readily distinguished from each other. The dividing line is placed 

at a bed at which the mottled limestone becomes highly charged with siliceous material in the 

form of ·chert nodules, while the limestone above changes from a mottled grayish-white with 

darker spots to a uniform buff, less crystalline rock. The faunal change is not very marked, 

but it will be noticed that the numerous large cephalopods that characterize the lower are 

almost altogether wanting in the middle division. 

The "Upper Mottled limestone" is described as varying in different localities 

and in partial sections from hard mottled dolomite exhibiting rough surfaces marked 

apparently by fucoids to soft, darker mottled impure earthy limestone which 

passes into the overlying Stony Mountain formation. The thickness is estimated 

at 130 feet near Winnipeg. 

The Stony Mountain formation is stated to represent the interval between the 

top of the Trenton and the base of the Silurian (upper). Dowlin5 describes the 

changes of thickness in strata which occupy this interval to the east and south 

and says: 

Although this formation is supposed to thin out altogether in northern Minnesota, there 

is found at Rosenfeld, in the southern part of Manitoba, a great thickness of c:;hale beds between 

limestone formations which are probably Trenton and Silurian. At Stony Mountain the section, 

although incomplete, in a known thickness below the Silurian of 110 feet, consists of shaly beds 

in the lower part with thick-bedded limestones above. The fossils from this part are mainly 

from the shaly beds below the limestone of the top of the section, and probably all these are 

collected from less than 50 feet below the top of the formation. We might infer from this that 

the upper part, that of which we have a section and a list of fossils, is referable to the Richmond group of Minnesota, and that the lower beds, mostly shales, are similar to the Utica of 

the Cincinnati formation. One species only, characteristic of the Utica of Minnesota has been 

found at Stony Mountain-Primitiella unicornis Ulrich. The majority of those common to 

the two localities are from the upper parts of the sections. It is noted in the Minnesota reports 

that several forms occurring in the Trenton appear in the Richmond group without any evidence of their presence in the Utica. The same might possibly be as;;erted of some of the Manitoba forms, as several are ~ound to range from the Trenton to the Stony Mountain formation. 

A complete list of fossils identified from these divisions of the Ordovician is 

given in Dowling's report. The faunas were earlier discussed by Whiteaves. 920 

Ulrich in commenting on this correlation states: 

Dowling's determination of the Manitoba Ordovician formations is based entirely on the 

Minnesota section of 1896. Much having been learned in the last 14 years concerning the 

Ordovician of the middle and far West, it is desirable to revise the classification of the rocks 

in both areas according to the present status of information. 

0 9. DEASE RIVER, BRITISH COLUMBIA. 

Blackish graptolite-bearing slates occur on lower Dease River near its junction 

with the Liard, in the belt of unaltered Paleozoic rocks of the eastern Rocky 

Mountains, near the sixtieth parallel. They were first seen in 1887 by G. M. 

Dawson/58a who states: 

From the second great bend to the mouth of the Dease the underlying rocks [underlying 

supposed Triassic] consist of gray and black schists, the former generally calc schists and the 

latter more or less highly carbonaceous. They are interbedded with thin limestones, which 

often weather brown. The calc schists are frequently glossy and in some places form very 

thin paper-like layers. Some of these rocks closely resemble those met with at the "Grand 
220 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Rapid" on the Stikine. The general strike is northwest by southeast, but the direction and 

angle of the dip is very varied and the beds are frequently much disturbed and twisted and 

traversed by veins of quartz and calcite. There are probably frequent repetitions of the same 

horizon, but the general arrangement may be synclinal, the dark shales and schists occupying 

the higher position and being most abundant about the middle of this length of the river section. 

Graptolites were found in the dark shales, particularly at a locality in a north bend of the 

river, 11 miles westward in a direct line from the mouth, and in appearance the whole series 

is much like that of the Cambrian calc schists and Cambro-Silurian graptolite shales of the 

Kicking Horse (Wapta) Valley, west of the summit, on the line of the Canadian Pacific Railway. 

With reference to the geologic horizon, Lap worth 523 reports: 

The graptolites collected by Dr. Dawson from the Dease River are identical with those 

examined by me from the rocks of the Kicking Horse Pass some time last year. 

The species I notice in the Dease River collection areDiplograptus euglyphus (Lapworth). 

Climacograptus comp. antiquus (Lapworth). 

Cryptograptus tricornis (Carruthers). 

Glossograptus ciliatus (Emmons). 

Didymograptus comp. sagittarius (Hall). 

New form allied to C<:X'nograptus. 

The graptolite-bearing rocks are clearly of about middle Ordovician age. They contain 

forms which I would refer to the second or Black River-Trenton period-that is, they are 

newer than the Point Levis series and older than the Hudson and Utica groups. The association of forms is such as we find in Britain and western Europe, in the passage beds between 

the Llandeilo and Caradoc limestones. The rocks in Canada and New York with which these 

Dease River beds may best be compared are the Marsouin beds of the St. Lawrence Valley 

and the Normans Kill beds of New York. The Dease River beds, perhaps, may be a little 

older than these. 

These rocks are also apparently very similar to the graptolite-bearing slates 

of the Alaska Range. 

0 15. SOUTHWEST COAST OF HUDSON BAY. 

An isolated occurrence of limestone containing Trenton fossils near Fort 

Churchill is described by Tyrrell. 818 The rocks had previously been observed by 

Bell on Churchill and Nelson rivers and assigned to the Galena-Trenton horizon of 

the Wiaconsin Geological and Natural History Survey by W.hiteaves, 912 who also 

recognized some probable upper Silurian or Devonian forms. 

In 1880 Bell 66 wrote: 

Geologically the basin of Hudsons Bay, excluding the western or Winnipeg division, lies 

within the great Laurentian area of the Dominion. Cambro-Silurian rocks, resting almost 

horizontally upon these, form an irregular border along the southwestern side of the bay, and 

in the valleys of some of the rivers they extend inland from 100 to 200 miles. To the south 

and west of James Bay the Cambro-Silurian [Ordovician] is overlain by Devonian rocks, which 

here occupy a considerable area. 

Among the notes of a preliminary report on the region between Lake Winnipeg 

and Hudson Bay, Low 549 includes the following: 

The limestones of the Severn and Fawn rivers, as roughly determined from the fossils 

collected, are not older than the Galena and may be as new as the Niagara; more investigation 

is, however, required to fix their precise horizon. 
MIDDLE AND UPPER ORDOVICIAN. 221 

The rock is a coarse yellowish-white dolomitic limestone, closely resembling that of Lake 

Winnipeg. It lies almost fiat, being broken only by long, low anticlines and synclines. At 

the Limestone Rapids of the Severn, where it is more contorted than usual, it rises in a number 

of low domes, closely resembling a sheet of letter paper when dampened. The total thickness 

of the beds exposed does not exceed 100 feet. 

References to these limestones occur in subsequent reports, but on account of 

the isolation and small areas of the outcrops there is no complete section nor any 

definite knowledge of the area of strata of Trenton age or of higher strata. Brock a 

states: 

With reference to the southwestern coast of Hudson Bay our information is not definite. 

There are very few exposures and only isolated fossils have been brought down, some possibly 

from loose bowlders. From Tyrrell's fossils and Bell's it is evident that there is at least a band 

of Trenton, and from other fossils it is certain that Silurian is present, but where the boundary 

lies between them we do not know. 

P-Q 3-7. ALASKA. 

Ordovician strata in Alaska are in general not distinguished on the map of 

North America, the areas in which they occur being classed as Paleozoic undivided. 

Their presence is known, however, through the discovery by Brooks and Prindle 104 

of Ordovician graptolites on the western slope of the Alaska Range, in carbonaceous 

strata which are intimately associated with phyllites, limestones, and cherts and 

which have been called the Terra Cotta "series." These strata are probably represented in the metamorphic rocks of the upper Tanana region, formerly known as 

the "Tanana" schist 101b but recently correlated with the Birch Creek schist.104 

Ordovician fossils have also been found on the Porcupine in bluish-gray nonmagnesian limestone 600 feet thick. 102 

Thus the presence of the Ordovician is shown on fossil evidence in the central 

eastern portion of the Alaska Peninsula. Similar fossiliferous beds are known at 

several points in British Columbia. Strata which have as yet yielded no fossils, 

the Wales "series," lie beneath and are older than upper Silurian in southeastern 

Alaska. On the other hand, toward the north and northwest from the Yukon 

region the more or less metamorphic schists of the Endicott Mountains and Seward 

Peninsula include early Paleozoic sediments, possibly Ordovician, and there are 

similar schists in southern Alaska about Prince William Sound and the Wrangell 

Range. 101 

P-Q 17-19. SOUTHAMPTON ISLAND, FOX LAND, AND UNGAVA BAY. 

The central portion of Fox or Baffin Land is mapped as Silurian, as are also the 

islands in the north of Hudson Bay. The presence of Ordovician strata is established 

in Frobisher Bay, and is probable throughout the areas in this region shown with 

the Silurian color. (See pages immediately preceding.) 

Akpatok Island, in the northern part of Ungava Bay, is described by Bell 68 

as presenting a wall of gray limestone 400 to 500 feet high all along the coast from 

the north end to the middle of the east side. The strata are horizontal and the 

total thickness exposed in the heights of the island is estimated at 900 feet, to which 

a Brock, R. W., Acting Director Geol. Survey Canada, letter May 27, 1908. 
222 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

may be added an unknown thickness beneath the sea. Low 550 states that the 

strata range in age from "Galena-Trenton to Lower Helderberg." 

Q 3-4. SEWARD PENINSULA. 

Kindle has contributed the following note on the Silurian and Ordovician of 

Seward Peninsula: 

The Port Clarence limestone furnished fossils which were determined as Silurian and 

Ordovician. Recent collections from this limestone show the presence of both Cambrian and 

Ordovician fauns,s and indicate that the fauna previously considered Silurian is of late Ordovician age. 

R-T 10-20. ARCTIC ARCHIPELAGO. 

Large areas in the Arctic Archipelago are colored as Silurian (upper Silurian or 

Gothlandian) in accordance with the dominant character of the fossils collected by 

several expeditions. Detailed references and descriptions are given in Chapter V 

(pp. 265-266). These Silurian strata, however, are in certain localities and probably 

as a rule underlain by Ordovician.· Dawson 257a summarizes: 

In a paper printed in the report of the British Association for 1855 J. W. Salter states that 

the Silurian fossils obtained up to that time showed a uniform horizon of Upper Silurian limestone stretching from near the entrance to Barrow Strait to Melville Island and far to the 

south along Prince Regent Inlet and argues therefrom a wide extent of circumpolar land in 

lower Silurian (Cambro-Silurian) times. In this he was followed, two years later, by Sir R. 

Murchison,a who writes: "I am led to believe that the oldest fossiliferous rock of the Arctic 

regions is the Upper Silurian." Though the Upper Silurian beds undoubtedly occupy a great 

part of the American polar region, characterizing the "South of North Devon and nearly all 

the islands south of Melville and Lancaster sounds, including the south of Banks Land, Prince 

of Wales Land, King William Land, North Somerset, Boothia, Felix, etc.," b the occurrence of 

Lower Silurian (Utica) fossils in Frobisher Bay, as shown by Hall's collections, on the shores 

of Kennedy Channel, as determined by Etheridge, and the occasional discovery of Lower 

Silurian forms in the regions above referred in a general way to the Upper Silurian prove that 

the generalization made by Salter and Murchison, on the evidence of less complete collections, 

can not now be admitted and that the limestones of the Arctic represent probably the whole 

of the Silurian [Lower and Upper], and possibly part of the Devonian.b Heerc enumerates 

the following places, besides those above particularly referred to, as yielding Lower Silurian 

types: North Devon, Cornwallis Island, Griffith Island, west coast of King William Land, 

Boothia. 

Dawson's inference was verified in 1900 by Schuchert,712 who studied new collections from Sillimans Mount, at the head of Frobisher Bay, and extended the 

basis of correlation with other areas in the Arctic Archipelago. After enumerating 

localities, Schuchert says: 

From the foregoing description of localities, it appears that middle Lower Silurian horizons 

are very extensive in easternArcticAmerica. Such are known in places on either side of Hudson Strait, Frobisher Bay, the interior of Baffin Land, and to the north of this land at various 

localities between latitudes 79° and 80° north. As far as known, these strata unconformably 

overlie very ancient crystalline rocks and are in turn overlain by Upper Silurian beds of Niagara 

or Wenlock age. Lower Cambrian rocks are found in southern Labrador, but in the region of 

a Appendix to McClure's voyage, p. 402; Siluria, p. 440. 

b Fielden and De Rance, Quart. Jour. Geol. Soc., vol. 34. 

c Flora Fossilis Arctica, vol. 1, p. 24. 
MIDDLE AND UPPER ORDOVICIAN. 223 

Baffin Land such are not known to be present. Here, then, there seems to be a complete 

break from the Laurentian to the Trenton, followed by another break paleontologically, in the 

absence of the Cincinnatian beds and probably the lower horizons of the Upper Silurian. The 

Lower Silurian fossils of this area indicate nothing older than th~ typical Trenton of New 

York and the Galena of Wisconsin and Minnesota, a and nothing younger than the Utica stage 

of the United States. The thickness of these beds is not less than 900 feet and probably 

exceeds this. 

Schuchert cites lists of fossils collected by Hall and described by Stevens 792 

and Emerson 318 and gives a new list of 72 species from Silliman's Fossil Mount 

and their distribution according to horizons (Lowville, Black River, Trenton, and 

Cincinnatian) and according to regions (Minnesota-Manitoba, New York-Ottawa). 

He concludes: 7123 

From Mr. Porter's description, it will be seen that the fossils recently collected at Silliman's Fossil Mount are from various horizons, and yet there is nothing to indicate the presence 

of more than one fauna. The foregoing list shows that at present there are 72 species known 

from this locality, and of these 28 are restricted to it. There are, therefore, 54 species which are 

common to other localities, a goodly number with which to make safe correlations. Of these 

54 species, 41, or 57 per cent of the known fauna, are also found in the region of Minnesot&, 

Wisconsin, and Iowa, while 17 are kn9wn to occur in New York and Ottawa. 

On comparing the 54 widely distributed species with those from definite stages in Minnesota, it is seen that 10 are also found in Birdseye (Lowville), 17 in the Black River, 38, or about 

70 per cent, in the Galena, the direct equivalent of the New York Trenton, and 11 in the 

Cincinnatian group. 

From these figures it is evident that the stage of Silliman's Fossil Mount belongs in the 

Galena, and that the fauna is more intimately related to that of the Minnesota region than to 

the Trenton of New York. When the New York Trenton fauna is restudied in the light of 

recent researches in Minnesota,b however, it will be shown that the two faunas have more in 

common than now appears. On the other hand, the lithological similarities of the Minnesota 

Galena and Silliman's Fossil Mount, light-colored shales predominating in both areas, may 

explain in large measure the close identity of these widely separated faunas. 

Schuchert 712b closes his paper with the following summary of the information 

available on the Arctic Ordovician: 

The only Lower Silurian horizons known in northeastern Arctic America are of Trenton and 

Utica age. The latter zone appears only on the north shore of Frobisher Bay, but the Trenton is found in various places from the north shore of Hudson Strait to latitude 81° north. 

The Lower Silurian is thickest on Akpatok Island, where it is from 400 to 500 feet in depth. 

Dr. Bell, however, estimates the entire thickness of these strata in this region to be not less than 

900 feet. 

In Baffin Land and apparently elsewhere in Arctic America the Lower Silurian strata 

rest unconformably on old crystalline rocks [except where Cambrian is present in the far north; 

see p. 155]. To the north of Baffin Land the former are overlain by beds of Niagara or Wenlock age. 

The Trenton faunas, occurring in various places around the insular Archean nucleus of 

North America, have much in common, and this indicates that the conditions at that time 

were very similar, while the sea was in communication throughout. As yet, however, the distribution of the strata, together with their faunas, are well known only to the south and southeast of the Archean nucleus, yet that of the west (Manitoba) and of the northeast (Baffin Land) 

show direct communication. 

a See Cambrian of Bache Peninsula, Chapter III, p. 155. 

b Paleontology of the Lower Silurian fossils of Minnesota: Geology of Minnesota, vol. 3, pts. l and 2, Geol. Nat. 

Hist. Survey Minnesota, N. H. Winchell, State geologist. 
224 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA" 

The Baffin Land fauna had an early introduction of Upper Silurian genera in the corals 

Halysites, Lyellia, and Plasmopora. In Manitoba similar conditions occur in the presence of 

Halysites, Favosites, and Diphyphyllum. Other Upper Silurian types do not appear to be 

present. 

The Trenton fauna of Silliman's Fossil Mount, at the head of Frobisher Bay, has 72 species, 

of which 28 are restricted to it. This fauna shows an intimate relationship with that of the 

Galena of Minnesota, Iowa, and Wisconsin. Fifty-seven per cent of the species of Baffin 

Land also occur in the Galena of the regions just mentioned. 

S 27. EASTERN COAST OF GREENLAND. 

The Ordovician and possibly Cambrian of northeastern Greenland are described 

by N athorst, 6090 who says: 

East from the Archean follows a formation of sedimentary rocks which are without doubt 

older than Devonian and at least in part must be considered of Silurian [Ordovician] age, since 

there were found at Cape Weber, besides others, Orthoceratites, together with small Orthis or a 

closely related brachiopod and small gastropods. Although these fossils in consequence of 

pressure and the poor condition of preservation resulting therefrom can not be specifically 

determined, a Silurian [Ordovician] ago is nevertheless indicated, since the Orthoceratites are 

younger than Cambrian; still it is not impossible that in tho lower formations there may be 

Cambrian strata. 

The strata of which the formation is composed are very variable and consist of white, 

yellowish, gray, and black limestone or dolomite; red, green, chocolate-colored, and dark 

slates; and red sandstone, together with perhaps in the lower portions yellowish sandstone. 

The Ordovician strata of this region are much folded and conformably overlain 

by the Devonian. 
Color, violet. 

Symbol, 16. 

CHAPTER v. 

SILURIAN. 

Distribution: General throughout northern and eastern North America, east of the Great 

Plains; represented by the Devonian color (15) in the Appalachian zone south of latitude 

38 o; known to be present in the Cordillera and Alaska but not generally distinguished by 

separate color, except in Mexico, Nevada, and British Columbia. 

Content: In the Appalachians in general includes Medina to Cayuga; in the southern Appalachians is mapped with Devonian; in eastern Canada and New York Helderberg is included 

on the map; in the interior, includes strata of Niagara age; in the Arctic the Silurian color 

covers areas of the limestone series known to include Ordovician and Silurian. 

Silurian areas. 

Page. 

G-H 12 _____________________ . __ Sonora, Mexico ............................... ___________ . ____ .. _ . . . . . . . . . 227 

H 13 ___________________________ Western Texas; trans-Pecos Texas .............. _ .... ___ . ______ . __ . _ ... _ . . . . 227 

I 12 __________________ . ___ . ___ .. Arizona (not rna pped) .............. _______ . _ ... ____ . _ ... ___ . __ . _ . _ . . . . . .. . 228 

I 13 _________________ .. __ .. ___ .. New Mexico ..................... ______ . ____________ .. _ .. __ . _____ . .. .. . .. . 228 

I 14 ________________ . __ . __ . _ . _ . _Oklahoma ................... _ .......... _ . .. . .. . .. . . . . . .. . .. .. . . .. .. . .. . .. 228 

I-J 16-17 .................. _._ .. Alabama, Georgia, Tennessee, West Virginia, and Virginia (mapped with 

Devonian) ... __ .......... __ . _ . ___ .. __ . __ ... _____ ....... _ . _ ............ _ . 230 

I-K 16 ............... _____ . ___ .Indiana, Ohio, Kentucky, and Tennessee (mapped with Devonian in Tennessee). 232 

J 15 ....... ______ .. ___ . _._._ .... Eastern Missouri and southern Illinois...................................... 236 

J-K 11-12 .... ________ ... __ . ___ .Nevada and Utah (not mapped in Utah).................................... 236 

J-K17-18 ...................... Eastern New York, New Jersey, Pennsylvania, and Maryland ............... 237 

K 10 ...... __ ................... Taylorsville district and Klamath Mountains, California (not mapped)........ 242 

K 15-16, L 16 .. __ .............. Iowa, northern Illinois, and \Visconsin..................................... 242 

K-L 12. _ .... _ ................ Southwestern Montana and western Wyoming (not mapped)................. 244 

K-L 17-18. _ .... _ .. _ .. _ .. ____ .Ontario and western New York .......... __ ................. _ ....... _...... 244 

L 16-17 ____ ... _ .. _ .. _ .. _ .... _ . Northern Michigan and Ontario ............................ _ ........ _ .. . .. . 245 

L 17 .... _ .. _. _ .. _ ............. Lake Temiscaming, Ontario .. _ .. __ ........................................ 250 

L 18-19 __ . __ ... _ .. _ . ___ ...... _Southern Que bee ............. __ .... __ .... _ ... __ .. ___ . __ . _ ...... _ .... __ .. . 250 

L 19 _. _____ .... _ . __ .. _ ..... _ . _New Hampshire ............ ______ .......... _________ ..... _ ... _ . _ . _____ .. _ 250 

L 20 ...... _ .... _ .............. Nova Scotia ...................... _ ... ___ ............... ___ . _ . _ . . . . . . . . . . . 250 

L-M 19-20 ..... __ ............. Maine, New Brunswick, and Gaspe .... _._ ........................ _........ 252 

L-M 21. ... _ .................. Newfoundland ................................................. __ ......... 256 

M 11. ....... ______ ............. Rocky Mountains of British Columbia .......... __ ........ __ . __ . . . . . . . . . . . . . 258 

M 20 ........................... Anticosti Island ............................... _ ......... _ ..... _.......... 259 

M-N 13-14 .................... Lake \Vinnipeg, Manitoba, and Saskatchewan .................... _.......... 261 

N-0 8 ........... _ ............ Southeastern Alaska (not mapped) ......................... _ ..... _ ..... __ .. 262 

N-0 10 ......... _ ............. Finlay and Omenica rivers section (not mapped)............................ 263 

N-0 15-17 .................... Southwest coast of Hudson Bay............................................ 263 

P 6-7 ......................... Southern Alaska, Cook Inlet to Yakutat Bay (mapped with Paleozoic 

undivided)............................................................ 263 

P 19 ...... _ .... _ .............. Ungava Bay .................... ----·..................................... 264 

P-R 9-10 ...................... Bear River and Mackenzie Valley ........ __ . __ ............... ___ ........... 264 

P-S 10-17 ....... _ ............. Arctic region ........................... __ .......... _..................... 264 

Q 3 ............................ Seward Peninsula (mapped with Paleozoic undivided)...................... 265 

Q 5-6 .......................... Yukon-Tanana region (not mapped) ......................... __ . __ .... _ .. __ . 266 

Q-R 5 .......................... Endicott Range (not mapped) ............................... _._. __ ... _. __ . 266 

S 27 ............ _ ........... _.See Chapter IV, p. 224. 

T 16-17 ........ ___ ............ Ellesmereland ...................................................... ___ .. .. 266 

48011°-12--15 225 
FIGURE 7 .-Sketch map showing the distribution of Silurian rocks represented on the geologic map of North America 

and the key to references_in the text. 

226 
SILURIAN. 227 

G-H 12. SONORA, MEXICO. 

Aguilera 9 in 1906 mentioned certain strata as" doubtful Silurian" in describing 

under that head "Quartzites and fossiliferous semicrystalline limestones, of gray 

color and siliceous character, with Encrinites cyathophyllum and Heliolites; these 

overlie compact gray and yellowish limestones which occur above a series of breccias 

and limestones." Aguilera does not name localities at which these rocks occur. 

The areas mapped as Silurian in Sonora are so assigned on authority of a manuscript map furnished by Robert T. Hill, and the strata may be similar to those 

described by Udden and Richardson as occurring in southwestern Texas. 

H 13. WESTERN TEXAS. 

Describing a region near Marathon, Tex., J. A. Udden 819 a says: 

There must be several thousand feet of sediments exposed in this area. They have been 

folded and faulted and dip, usually at high angles, either to the southeast or to the northwest. 

* * * In the south part of the area they consist largely of dark shales and limestones. These 

contain heavy ledges of cherty quartz, which rise in long ridges running from the northeast to 

the southwest. The chert is usually interbedded with ledges of dark limestone, which now and 

then contain round and loaf-like concretions of chert. The prevailing color of the chert is white, 

but it is sometimes black, green, bluish, or of a brown or a pinkish color. With some of the 

limestones there are thin seams of sandstones and conglomerates. The latter usually consist 

of well-worn pebbles, mostly of limestone, but also of hard quartzite. In some shales, which are 

associated with chert and limestones in a ridge on the south side of Edwards Creek, about·lO 

miles northeast of Santiago Peak, there is one stratum which contains large concretionary aggregates of crystals of barite. Some of these aggregates are a foot in diameter and consist of 

columnar crystals radiating from the center of the concretions. The mineral was seen to 

follow a stratum about 3 feet in thickness, and the concretions in one place appeared to be 

present in large quantity. The limestones themselves are frequently bituminous. Some 

ledges consist of small worn organic fragments. From one of these some fossil fragments were 

taken which Dr. Charles Schuchert has identified as the outer portions of the glabella of a 

Trinucleus. Associated with this there were also a Plectambonites (sericeus ?) , a Rafinesquina, 

and possibly a Zygospira. A gastropod of the genus Cyclora was found in another ledge, and 

in still another limestone a Nodosaria was noted. All of these fossils were collected _along the 

wagon road near Ridge spring and at different points south from this place for a distance of 10 

miles. The same kind of rocks continue north from this spring as far as to Peiia Colorado, 

4 miles south of Marathon. North from Peiia Colorado we find shales, limestones, and thin 

conglomerates, but no chert beds. An Athyris, a Fistulipora(?), a Dentalium, and joints 

of crinoid stems were observed in the vicinity of Marathon, where the dip of these rocks is quite 

generally to the northwest. Evidently these sediments are younger than the formation which 

contains the chert south of Peiia Colorado. 

The thickness of the ancient sediments, which are seen on these plains around Marathon, is 

no doubt several thousand feet, and they very likely contain formations of more than one age. 

For 25 miles the road from the Chisos runs over the edges of beds tilted at high angles. The 

fossils associated with the chert show that some of these strata belong to the Ordovician, and 

Dr. Schuchert infers that these are of the Trenton period. In his "Physical geography of the 

Texas region" Prof. R. T. Hill expresses it as his opinion that the limestones, shales, etc., 9f these 

plains may be of Lower Helderberg age,a and there is no good reason to doubt that the Silurian 

rocks are represented in this extensive complex of folded strata. ·---·------------- a Folio 3, Top. Atlas U. S., U. S. Geol. Survey, 1900, p. 4. 
228 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

H 13. TRANS-PECOS TEXAS. 

With reference to the Silurian in the district lying north and east of El Paso 

Richardson 668 b states: 

The Silurian system in trans-Pecos Texas is represented in the El Paso region [by] the 

Fusselman limestone in the Franklin and Hueco mountains. This is a massive whitish magnesian limestone approximately 1,000 feet thick. It overlies the Montoya limestone apparently 

conformably, although in one locality fragments of the underlying limestone included in the 

Fusselman give evidence of an unconformity. Throughout the greater part of the formation 

fossils are scarce, but at a few horizons they are very abundant. The commonest form is a 

species of radially plicated pentameroid shell which, with Amplexus and Favosites, determined 

by Mr. Ulrich, proves that the upper Niagaran stage of the Silurian is here represented. Gordon 

and Graton a have recently found Silurian fossils in the Silver City region and at Lake Valley, 

N. Mex.; and Taff's Hunton formation in Oklahoma b also contains a Silurian fauna. 

I 12. ARIZONA. 

Reagan 663 states in regard to the Silurian: 

The Upper Silurian.-Immediately overlying the Tonto at its outer edge and possibly 

conformable with it are red to brown fossiliferous coarse-grained lime rocks having a thickness 

of about 70 feet. They form only a narrow band but are continuously exposed from the Tonto 

basin to Nan tan Mountains, where not covered with talus or lava. The best exposures observed 

by the writer are on the trail to the Salt springs, some 10 miles southwest of the farmer's residence on Cibicu, and on the Jolm Dazen trail near the Oak Creek break about a half mile southeast of Oak Creek cliff houses. This formation is Silurian; at least the fossils obtained, Orthis 

davidsoni, Strombodes pentagonus, etc., seem to bear out this conclusion. 

I 13. NEW MEXICO. 

Lindgren 542 b gives the following account of the Silurian of New Mexico: 

The Silurian is recognized at Silver City, at Lake Valley, and probably also at Hillsboro as 

thin beds of limestone and quartzite, but does not seem to be present everywhere between these 

places. It lies conformably above the Ordovician and at Silver City can not be differentiated 

from it. In the Franklin Range of Texas Richardson measured 1,000 feet of Silurian limestone. 

I 14. OKLAHOMA. 

The Arbuckle Mountains of Oklahoma comprise Silurian and Devonian strata 

which were separated by Taff into two mapped formations. The lower formation, 

the Sylvan shale, is of Silurian age, and the upper, the "Hunton limestone," is 

of Silurian and Devonian age. The Sylvan overlies the highest known fauna of the 

Ordovician, yet its fauna is related to the Utica of the New York Ordovician. The 

"Hunton" contains strata carrying in succession Niagara, Helderberg, and 

Oriskany faunas. The following is the stratigraphy and paleontology according to 

. Taff and Ulrich: sosb 

The Sylvan shale and the succeeding Hunton limestone are comparatively thin formations. 

* * * The nearly pure lime deposits laid down at the close of Viola [upper Richmond, latest 

Ordovician] time were succeeded by dark-blue to black and green clay in apparently conformable succession. The deposition of the greenish Sylvan shale continued without interruption 

until it reached a thickness of from 60 to 300 feet. * * * 

a Am. Jour. Sci., 4th ser., vol. 21, 1906. 

b Tishomingo folio (No. 98), Geol. Atlas U. S., U. S. Geol. Survey, 1903. 
SILURIAN. 229 

A preliminary study of the fossils occurring in the dark basal shale shows the following 

forms: 

Diplograptus sp. undetermined. 

Climacograptus sp. ncar typicalis. 

Leptograptus sp. undetermined. 

Lingula; short, obtuse form. 

Lingulops? sp. nov. (platform obsolete). 

Leptobolus sp. near insignis. 

Leptobolus? sp. nov. (has six strong radiating plications). 

Conularia sp. nov., with surface sculpture very similar to 

that of the Trenton C. papillata Hall. 

Conodonts of forms resembling those referred by Hinde to 

Prioniodus and Polygnathus. 

The fauna of the Sylvan shale as far as known is generally remarkably similar to that of the 

Utica. The specific differences, however, are such as to distinguish them; yet a study of the 

fossil nvinees one that the fauna of the Sylvan is a direct development from the much older 

fauna of the Utica shale and not of the intervening faunas of the Cincinnati group. From this 

evidence it would seem that the position of the Sylvan shale in the time seale is problematicaL 

The highest known fauna of the Ordovician, that of the Richmond group, occurs at the top 

of the Viola limestone, beneath the Sylvan shale, and the Clinton occurs immediately above the 

Sylvan, in the base of the Hunton limestone. According to the present classification, therefore, 

the Sylvan shale should be correlated with the Medina, and the line separating the Ordovician 

and Silurian in the Arbuckle Mountains should be placed between the Viola limestone and the 

Sylvan shale. 

The green clay shales of the Sylvan [Silurian] are succeeded abruptly by hard white to lightblue limestone of the Hunton formation. Usually the contact rock at the base of the Hunton is 

a massive bed of oolitic limestone. Locally hard bluish limestone beds are found at the base, 

with rarely a thin layer of brecciated limestone or limestone conglomerate in contact with 

Sylvan shale. * * * 

The Hunton formation is composed of hard, thick crystalline limestones, thin earthy limestone, and marls. It may be separated into three fairly distinct members according to lithologic characteristics, and to a less extent according to color. Except where the formation is 

very thin * * * the three members can always be distinguished. An average section 

of the formation on the south side of the Arbuckle Mountains west of Washita River is approximately as follows: 

Section of Hunton limestone. 

Feet. 

Upper member: Semicrystalline limestone, in places cherty, interstratified with occasional 

thin marly layers.................................................................... 30 

Middle member: Marly limestones and calcareous clays, with some hard limestone layers, 

more abundant in the lower part ....................................................... 170-190 

Lower member: Thick-bedded crystalline limestone succeeded by hard thin limestone with 

occasional marly layers. At the base of this limestone is an oolite, 4 to 5 feet thick, which 

locally is silicified.......................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35-40 

The lithologic differences by which the members are distinguished are accompanied by 

faunal changes which afford a basis for age distinctions. The more massive crystalline beds in 

the lower part of the basal member, ranging in thickness from a thin bed to 25 feet or more, 

contain forms which are distinctly Clinton. Four Bryozoa and Triplecia ortoni are characteristic of the Clinton limestone of Ohio, and their horizon occurs in the St. Clair limestone of 

northern Arkansas. * * * 

The hard thin limestone beds in the upper part of the basal member contain fossils which 

indicate Niagara age. * * * 

The middle member of the Hunton limestone as a whole is abunoantly fossiliferous. * * * 

There can be no question as to the Helderbergian age of this member of the Hunton formation. 

The uppermost member of the Hunton formation is probably lower Oriskany in age and 

equivalent to the Camden chert of Tennessee. * * * 

According to the classification of the Paleozoic rocks at present in vogue, this member should 

be called Devonian, but it is so intimately united, both faunally and structurally, with the under-
230 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

lying Helderberg member, that, for this region at least, it would be doing violence to the natural 

classification of the rocks to draw a line of systemic importance between them. According 

to a classification taking into account both the life history and structure of the strata, this 

divisional line should be drawn either between the flinty beds at the top of the Hunton limestone 

and the base of the black shale and chert of the overlying Woodford formation, or between the 

Niagara and Helderberg members. In the latter case the lower member only would be Silurian, 

and the two upper members Devonian. 

I-J 16-17. ALABAMA, (}EORGIA, TENNESSEE, WEST VIRGINIA, AND VIRGINIA. 

In the zone of Appalachian folds from Maryland southward, the Silurian strata 

consist of the basal littoral formations and the overlying Clinton ("Rockwood" or 

"Dyestone") of the Southern States. The basal sandstones (Bays, Ordovician, 

and Clinch, Silurian) extend from Virginia along the valley of east Tennessee to 

the longitude of Knoxville. The Clinton or "Rockwood" alone is continuous to 

Alabama. Higher Silurian deposits, the equivalents of the Niagaran and Cayugan, 

thin and disappear in southwestern Virginia and northeastern Tennessee, as shown 

in the sections given below. The Helderbergian is here classified as Devonian, and 

the upper limit of the Silurian therefore falls in the lower part of the Lewistown 

limestone of the following sections. The Silurian outcrops in narrow belts intimately associated with and practically coextensive with the Devonian and is, in 

view of the small scale of the map, indistinguishable from the Devonian in the 

generalized drawing of the complex structure. The Silurian is therefore represented 

with the Devonian by the color of the latter south of northern Virginia. 

In eastern West Virginia (Piedmont quadrangle) the Silurian has been classified by Darton 228 as follows: 

Top. Feet. 

Monterey sandstone, in part; massive calcareous blue-gray sandstone (in part Devonian). 215-300 

Lewistown limestone (equivalent to Lower Helderberg [Devonian], Salina, and Niagara): 

Cherty limestone (Lewistown chert lentil) .......................................... 130--300 

Massive light blue gray limestone ...... ---- ... ------.--.------ .... ----.---- ..... --. 20-- 80 

Shaly limestone................................................................. 100 

Dark-colored limestone ..................... -- .................. --.-- .. --......... 30-- 60 

Flaggy limestone ................................................................ 450--980 

Thin beds of impure limestone with alternations of greenish and gray calcareous shale. 250--310 

Rockwood formation (Clint<:m): 

Gray sandstone................................................................... 12- 20 

Gray, brownish, and greenish shale with iron ore and thin limestone beds ........... 525-750 

Cacapon sandstone: Red sandstone, mainly thin bedded................................. 300 

Tuscarora quartzite: White or gray massive quartzite................................... 480 

Juniata formation: Brownish-red sandstone and shale.................................... 750+ 

The Juniata, Tuscarora, and Cacapon Darton regarded as the representatives 

of the Medina of New York. 

Traced through the Franklin quadrangle, south of the Piedmont, the divisions 

of the Silurian in the Staunton quadrangle, in central Virginia, are similar but 

reduced in thickness, as shown by Darton 226a in the following section: 

Silurian rocks in Staunton quadrangle, Virginia. 

Feet. 

Monterey sandstone (Silurian and Devonian, Oriskany), in part calcareous.................. 0--300 

Lewistown limestone (Silurian): Cherty limestone, pure limestone ......................... 300--500 

Rockwood formation (Clinton): Gray quartzite, sandy shale .......................... ,_ ... 150--200 

Massanutten sandstone (Medina): Reddish sandstone, gray quartzite, red and gray sandstones. 500--600 
SILURIAN. 231 

1n southwestern Virginia, in the Pocahontas quadrangle, Campbell 123 did not 

distinguish the "Monterey" sandstone (Oriskany) and Lewistown limestone but 

named the strata which occupy the interval between the Clinton and the Devonian 

the Giles formation. His section is as follows: 

Feet. 

Giles formation (Oriskany and Lower Helderberg [Devonian]): Coarse yellow sandstone, 

cherty limestone, coarse reddish sandstone, blue limestone ................... _ ... _._ .. _. 30-200 

Rockwood formation (Clinton): Heavy sandstone or quartzite, sandy shale and ferruginous 

sandstone with siliceous red fossil ore and hematite...................................... 20-400 

Clinch sandstone (Upper Medina): Coarse white sandstone or quartzite .................... 150-250 

Bays sandstone (Lower Medina) [Ordovician]: Red sandstone and sandy shale ............. 250-350 

The Giles formation comprises strata which are grouped because they are 

usually covered and can not be distinctly traced. In the Kimberling Wilderness, 

in the eastern part of the Pocahontas quadrangle, Campbell recognized the following 

divisions: 

Feet. 

Greeilish sandstone locally containing pebbles of the limestone at the base of the group; thickSection of the Giles formation [Devonian]. 

ness not determined. 

Cherty limestone or chert .... _ ... __ ... _ . _ .. ___ .. __ .... _ ... __ .. _ . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-40 

Coarse ferruginous sandstone locally composed of small quartz pebbles cemented by iron oxide. 15-20 

Blue limestone, shaly at the base ..... __ ... __ .. __ ............................ _ .. ____ ... _ .. 30-40 

At the boundary between Virginia and Tennessee (in the Bristol quadrangle) 

the Silurian consists of the Clinch and Clinton or "Rockwood" formations, together 

with the Hancock limestone (Silurian and Devonian). Here the Bays, Ordovician 

(350 to 450 feet), and Clinch (250 to 450 feet) are thicker; the Clinton or "Rockwood?' (200-300) is similar in thickness to the last section cited. The characters of 

these formations remain the same. 

The Hancock is a blue fossiliferous cherty limestone. It also appears in the 

northwest corner of the Morristown quadrangle, Tennessee, in latitude 36° 30' 

north, longitude 83° 30' west, but does not occur farther south. Keith 477 states: 

In the Powell syncline are found the only areas of this formation [the Hancock limestone] 

in the valley of east Tennessee, and from its occurrence here in Hancock County it derives its · 

name. The formation consists entirely of interbedded massive and shaly limestones of a blue, 

gray, or dove color. Massive beds are more frequent at the bottom and top of the formation 

and attain a thickness of 20 feet. Great numbers of fossils, largely brachiopods, corals, and 

crinoids, are found throughout the formation and show it to be of upper Silurian [Helderberg, 

Devonian] age. 

In the Greeneville quadrangle, Tennessee (longitude 82° 30' to 83° west, 

latitude 36° to 36° 30' north), east of the Morristown quadrangle, the Silurian 

comprises the Clinch and part of the Clinton ("Rockwood"). The section as 

given by Keith 481a is as follows: 

Feet. 

Rockwood formation: Green, red, and yellow sandy and calcareous shale................. 700+ 

Clinch sandstone: Massive white sandstone ..................... __ ...................... 300-500 

Bays sandstone [Ordovician]: Massive and shaly red sandstone ... _....................... 50-400 

In the northwestern part of the quadrangle the Clinton ("Rockwood") is 

lacking and the Chattanooga shale (Devonian) rests on the eroded Clinch sandstone. 

In the Briceville quadrangle, 60 miles west of the Greeneville, the Bays (Ordovician) is a "red argillaceous and sandy limestone, 160 to 200 feet thick;" the 

Clinch sandstone is absent, and the Clinton ("Rockwood"), which rests conformably 
232 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

on the Bays, consists of red and brown calcareous shales, is 400 to 500 feet thick, 

and carries beds of fossiliferous limestone 4 to 8 feet thick which constitute the 

fossil iron ores so far as the lime has been replaced by iron. 478 

The type locality of the "Rockwood" formation is in the Kingston quadrangle, 

Tennessee. The "Rockwood" is there the only representative of the Silurian, but 

no unconformity is noted either below it at the contact with the Athens shale or 

Chickamauga limestone (Ordovician) or above it at the contact with the Chattanooga shale (Devonian). Hayes 420 states that the "Rockwood" (Clinton) varies 

widely in character and thickness within the quadrangle. About the head of the 

Sequatchie Valley "it is 165 feet thick and is composed of calcareous shales interbedded with blue limestone." Along the foot of the Cumberland escarpment "it 

is about 600 feet thick and consists of calcareous and sandy shales. Still farther 

east * * * the formation attains a thickness of 850 to 1,000 feet, a considerable 

part of which is coarse sandstone interbedded with sandy shales. Toward the top 

are sandy shales and a few calcareous beds, with which is associated the iron ore." 

A similar description applies to the "Rockwood" (Clinton) as it occurs in the 

Chattanooga quadrangle, Tennessee, as far south as latitude 35°. 

I-K 16. INDIANA, OHIO, KENTUCKY, AND TENNESSEE. 

Silurian strata envelop the Cincinnati arch and the Nashville dome in the 

States of Indiana, Ohio, Kentucky, and Tennessee. There is in many places an 

unconformity at their base corresponding to the latest Ordovician. The strata 

themselves are very largely limestones, which differ locally in character and in 

faunal contents. They have been minutely classified, and the details are to be 

found in the State reports and in recent articles. 336, 337, 340, 341 , 342, 431 

The Silurian strata of Indiana may be divided, according to Foerste, 342 intoFeet. 

Louisville limestone (at the top). ___________ -- ____ -- ___ -----------_---------------------- 55+ 

·waldron clay _________________________________________ - _____ -. ____ -. ___ - -.. __ - - - - __ - - -. _ 4-20 

Laurel limestone ______________________ -- ___ ---- _---------------------------------------- 40-43 

Osgood clay and limestone _____________ ----_---------------------------------------------- 11-16 

Clinton limestone (at the base) .. ___________ -----.-----------------.---------------------- 0-11 

The "Clinton" is regarded by Foerste as distinct. The other four divisions 

he assigns to the Niagara. 

The "Clinton" succeeds the Ordovician with local unconformity and contains 

rounded fragments of Ordovician rocks around the margins of islands, which it did 

not cover. It is in many places a detrital limestone but has also dense siliceous or 

clayey facies. 

The Osgood consists chiefly of clay shale with 8 to 15 inches of limestone at 

the base. Where the shale gives place to lime the limestone thickens, and it is 

correlated with the Dayton limestone of Ohio. 

The Laurel limestone is usually hard, white, and evenly bedded. Toward the 

south it becomes softer and more argillaceous. 

The Waldron shale is a distinct bed overlying the Laurel, and is mainly a clayey 

shale having the facies of the Osgood shale. It becomes calcareous toward the 

north. 
SILURIA~. 233 

The Louisville limestone, which at Louisville is unconformably overlain by 

Devonian limestone and has a thickness of 55 feet, is described as thinning out 

toward the north and east. Foerste 312b comments as follows on the relations of 

Silurian and Devonian: 

The absence of any mention of distinct unconformity at most localities so far examined 

suggests that the Silurian-Devonian eontaet is not marked everywhere by strong unconformity, 

but that at many points in northern Indiana the unconformity is slight. In the southern part 

of the State the Silurian-Devonian contact is also accompanied by a slight unconformity. 

The \Valdron shale and its abundant fauna constitute the subject of an article 

by Kindle and Barnett, 504 who refer to the paleontologic work of Hall and state 

in part: 

The Waldron shale is composed mainly of fine-textured blue to greenish day shale. Thin 

bands of impure limestone and calcareous nodules sometimes occur in the shale but represent 

a comparatively insignificant proportion of the formation. The Waldron shale has a thickness 

ranging generally from 4 to 10 feet. So far as observed by the writers the Waldron beds are 

conformable with the Niagara limestone beds above and below. * * * Although a very 

thin formation, the Waldron is very persistent and extends southward from southern Shelby 

and Rush counties to the Ohio River, a distance of about 85 miles. The Waldron shale is not 

known north of the central part of the State. The heavy mantle of drift to the north of its 

northernmost exposures in Rush and Shelby counties conceals a large area in which important 

stratigraphic changes take place, the precise nature of which is unknown. All that we know 

certainly about them is that they result in a Silurian section in the vV abash Valley in which 

neither the vV aldron shale nor its two accompanying limestone formations have been identified. It may be that the Cincinnati geantidine, which is believed to have been in existence 

during the vV aldron shale interval, as pointed out elsewhere in this paper, swung to the westward across north-central Indiana, making distinct marine basins in northern and southern 

Indiana. Certain differences in the faunas as well as the stratigraphy of the Silurian of the 

northern and southern Indiana sections could be cited in support of this hypothesis. 

The fauna of the \Valdron, which comprises 160 species, is contrasted by Kindle 

and Barnett with that of the Louisville limestone, with which it has remarkably 

little in common. Full lists of fossils are given. 

The faunas of the several divisions of the Silurian in Indiana are distinguished 

by Foerste/42 a who recognizes close affinities between those of the Laurel and 

Louisville on the one hand and between those of the Waldron and Osgood on the 

other. 

The divisions enumerated are described particularly from occurrences in 

southeastern Indiana; in northern Indiana the Niagara strata are not differentiated. 

The identification of these Niagaran formations and their correlation with the 

New York section are considered by Foerste. He also identifies a water-lime rock 

occurring at Kokomo, Ind., as the probable equivalent of the Bertie water lime 

(lower Cayugan) of the New York State reports. 

The Silurian of Ohio was classified by Prosser 651 in 1905 as follows: 

Northwestern Ohio. Feet. 

!

Lucas limestone ....... ·j J\fonroe formation Sylvania sandstone ........................... ~....................... 50-600 

Tymochtee member(?) .. 
234 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Northern Ohio. Southern Ohio. Feet. 

Hillsboro sandstone ... . 

Cedarville limestone ... . 

"Niagara group" Springfield limestone .. . 

West Union limestone. . · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · 150-350 

Osgood beds .......... . 

Dayton limestone ...... . 

Clinton limestone. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-50 

Northern Ohio. Southern Ohio. 

Medina shale(?) Belfailt bed (5 feet) ............ :. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50-150 

Detailed descriptions of the formations are given by Prosser 649 m another 

article. 

The Silurian and Devonian limestones of Tennessee and Kentucky are discussed by Foerste 336a in some detail. He locates the Cincinnati anticline in these 

States and says: 

This fold was in existence in early Devonian, if not in Silurian times. No Silurian formations occur along the crest of the fold in central and southern Kentucky, or in northern and 

central Tennessee. * * * Surrounding this area and overlapping the Ordovician on the 

flanks and ends of the anticline are Silurian strata, the total thickness of which diminishes on 

approaching the crest of the fold. 

The result is that Devonian strata rest on Silurian formations along the flanks and ends 

of the anticline, but along the crest, from north of central Kentucky to southern Tennessee, 

they rest directly on the Ordovician. * * * 

There is * * * a remarkable similarity in the characteristics shown by the most 

southern Silurian exposures in Kentucky and the most northern outcrops in Tennessee. This 

similarity extends even to the minor subdivisions of the group. * * * 

The most accessible of the Silurian sections in northern Tennessee is that along the Louis-' 

ville & Nashville Railroad, near South Tunnel, about 10 miles south of the Kentucky border. 

In several railroad cuts Foerste found the Chattanooga shale (Devonian) 

resting upon the Waldron shale (Silurian), and that in turn upon the Laurel limestone, 28 feet thick. 

Both in Kentucky and Tennessee the top of the limestone [Laurel], especially the oolitic 

layer, contains fossils which also occur but in greater abundance in the Waldron shale. At 

South Tunnel Whitjieldella nitida occurs in the oolitic layer. Orthoceras amycus is found near 

the middle of the Laurel limestone. Pisocrinus gemmiformis is common near the base. This 

fossil is especially abundant at a fourth railroad cut. * * * The base of the formation 

is here a crinoidal limestone. In Indiana and northern Kentucky Pisocrinus gemmiformis 

occurs abundantly, both in the base of the Laurel limestone and in the limestone layers placed 

at the top of the Osgood beds. Farther south it becomes difficult to determine where to draw 

the line between the limestone layers belonging to the Laurel and those referred to the top 

of the Osgood beds. In Tennessee it is impossible to make such a separation, and here all of 

the limestone section is referred to the Laurel. 

Foerste mentions localities where the Laurel limestone rests on clayey material 

which stratigraphically undoubtedly represents the Osgood shale of Kentucky 

though lithologically it is much less shaly. 

At South Tunnel the Clinton-is first seen in the form of fragments of fossiliferous chert. 

* * * The lower part of the Clinton is a bluish limestone, containing much less chert and 

only a few fossils. It resembles so much the top of the immediately underlying Ordovician 

rock, in which fossils are also scarce, that it requires patience to determine where to draw the 

~ine between the Silurian and the Ordovician rocks. 
SILURIAN. 235 

Foerste 340a also discusses the limestones of western Tennessee, in part as 

follows: 

In southern Indiana the Silurian strata are divided into the following beds, named in 

descending order: 

Louisville limestone. 

Waldron shaly clay. 

Laurel limestone. 

Osgood shaly clay. 

('linton limestone. 

Southward, along the western flank of the Cincinnati geanticline, the equivalents of 

these beds may be traced with varying success even as far as northern Alabama. * * * 

Very little change is shown in the lithological characteristics of any of these subdivisions between 

southern Indiana and northern Tennessee. North and south of this area, however, the Osgood 

bed rapidly becomes more calcareous and is changed from a shaly clay to a soft limestone, 

weathering more readily than the Clinton limestone below or the Laurel limestone above. 

The Waldron bed also becomes calcareous northward and is replaced by limestone in central 

Indiana. Southward it may be traced as far as northern Alabama, but in central and southern 

Tennessee it is only 3 to 4 feet thick, and along the middle part of the bed the clay is replaced 

by a layer of limestone 6 to 10 inches thick. Both northward in Indiana and southward in 

Tennessee the Waldron bed maintains its characteristics as a shaly clay farther than the 

Osgood bed. · 

The thickest sections of the Osgood bed are found in central Kentucky. * * * At Bledsoe in northern Tennessee, the Osgood bed consists chiefly of soft clay. * * * In central 

and southern Tennessee the Osgood bed consists of rather thin bedded limestones weathering 

back more readily than the Laurel bed above and the Clinton bed beneath. Here its identity 

can often be established only with difficulty. 'The Waldron bed maintains its character as a 

shaly clay horizon much farther southward than the Osgood bed. It is typically developed 

along the Harpeth River near Newsom. At this locality it contains a large part of the fauna 

characteristic of this horizon at Waldron, Ind. In central and southern Tennessee a thin bed of 

limestone, 6 to 10 inches thick, replaces the clay along the middle of the bed. * * * 

Along the western flank of the Cincinnati geanticline, in southern Indiana, Kentucky, and 

Tennessee, the name Louisville bed has been given to the Silurian rocks overlying the Waldron 

bed. In the Tennessee River valley, in western Tennessee, the Silurian section overlying the 

Waldron bed is so thick that it has been found necessary to subdivide it .. 

At the base is a series of limestones, varying from 30 to 45 feet in thickhess, to which the 

name Lego limestone is here given. Stratigraphically this bed occupies the same position as the 

Louisville bed. Its paleontological equivalence, however, has not yet been determined, owing 

to the small number of fossils so far obtained in the Lego limestone. Overlying the Lego limestone is a series of red clays, 30 to 45 feet thick, to which the name Dixon clay is given. This 

clay h~s so far proved comparatively unfossiliferous. * * * Above the Dixon red clay is a 

section of white limestones and clays, exceeding 100 feet in thickness. This section is often richly 

fossiliferous. * * * To this section overlying the Dixon red clay the name Brownsport bed is 

here given. 

Lithologically the limestones forming the middle and lower part of the Lego bed often 

resemble those forming the Laurel bed so much that, in the failure to identify the Waldron 

horizon, it is impossible to distinguish the same. 

Foerste 340d gives the early and later nomenclature applied to the strata and 

the equivalence of the limestones to other beds. The Clifton formation (the 

Meniscus limestone of Safford) includes all the Niagaran strata present in western 

Tennessee. 
236 INDEX TO THE STRATIGHAPHY OF NORTH Al\IERICA. 

J 15. EASTERN MISSOURI AND SOUTHERN ILLINOIS. 

According to Savage 703a the Silurian is represented in southern Illinois only 

by thin-bedded dark-gray limestone with chert overlain by heavy-bedded pink or 

mottled limestone, the whole 29 to 75 feet thick, to which he applied the name Clinton. Savage states that the fauna corresponds to that obtained from the Clinton 

(so called) of Dayton, Ohio. 

In eastern Missouri there is a white oolitic limestone followed by buff dolomite, 

10 to 30 feet thick altogether, which may represent the Niagara 491b or may be of 

Devonian age. It rests on Maquoketa shale (Ordovician) and is overlain by the 

Louisiana limestone (Mississippian). The occurrence is not shown on the map 

accompanying this volume. 

J-K 11-12. NEVADA AND UTAH. 

In the Eureka section, Nevada, the Eureka quartzite (Ordovician) is accordihg 

to Hague 391a unconformably followed by" steel-gray, almost black gritty limestone" 

and "dark bluish-gray limestone" about 300 feet thick, which contain Trenton 

fossils. There is no lithologic division but a gradual passageinto light-gray siliceous limestone, with a peculiar saccharoidal texture, in places becoming 

almost white and wholly without bedding. On the surface the limestones weather brown and 

buff, their light colors throughout a great vertical range standing out in strong contrast with the 

other massive beds of the Paleozoic. It weathers in rounded outlines, breaking with an irregular fracture and presenting a monotonous appearance wearisome to the eye. Rock of this character makes up by far the greater part of the horizon, and then by slow, imperceptible changes 

it becomes darker in color, with more and more tendency to develop planes of stratification, 

and gradually passes into the overlying limestone of the Devonian. 

As already mentioned, an unconformity exists between the Eureka quartzite and the Lone 

Mountain limestone. There is therefore no direct evidence in the district of the thickness of the 

limestone. The average thickness of strata exposed has been taken at 1,800 feet, but it is 

probable that tllis is under rather than over estimated, and at Lone Mountain they attain a 

somewhat greater development, at least 2,000 feet being exposed. * * * 

Above the Trenton no good grouping of fossils has as yet been discovered until the Devonian 

rocks are reached.· The other portion of the Silurian limestone presents a most forbidding aspect 

for the preservation of organic remains, and although diligent search has been made throughout 

the horizon it was rewarded only by finding a few imperfect corals, belonging to the species 

Hal:ysites catenulatus, which is so characteristic of the Niagara of the East, and here found in what 

should be its true geological position. They have a wide range and occur nearly 1,500 feet above 

the sumnlit of the Eureka quartzite. The same coral has been obtained from Lone 1\Iount.ain 

and White Pine, and in both these latter localities associated with the genus Zaphrentis. 

See also Walcott 847 on the paleontology of the Eureka district. 

The distribution of the Lone Mountaih limestone (now regarded by Ulrich as 

all Ordovician and so treated by Emmons 324 in a recent report) or its equivalent 

strata has been traced chiefly by Spurr 772 and by ·weeks (in an unpublished paper), 

from whose maps the formation is sketched. 

A recent note on the occurrence of a Si~urian fauna in Utah has been given by 

Kindle.498b The section corresponds with that at Eureka, the fauna occurring in a 

magnesian limestone 200 ~o 300 feet thick, below which is a much darker limestone 

of undetermined age and above which lie dark magnesian limestones of Devonian 
• 

SILURIAX. 237 

age. The locality is in the Wasatch Mountains in northeastern Utah, and the same 

section was observed in Logan Canyon, 12 miles farther north. 

Blackwelder 84e as a result of recent work says: 

As exposed on the crest of the range [Wasatch] there is, between the Ordovician quartzite 

and the identifiable part of the Mississippian limestone, a succession of dark limestones * * * 

having a thickness of 1,000 to 1,500 feet. In the lowest beds there are corals such as Halysites 

and Favosites. At a slightly higher horizon there are abundant shells which Kindle thinks are 

the same as his Pentamerus fauna of the Bear River Range. 

J-K 17-18. EASTERN NEW YORK, NEW JERSEY, PENNSYLVANIA, AND MARYLAND. 

Grabau 384 describes the Si!urian of New York and its relations to other sections in part as follows: 

The following divisions of the New York Niagaran are in common use as the North .American 

standard: Guelph, Lockport, Rochester, Clinton. 

The Clinton of the best-known section, that of western New York, begins with the true 

or Upper Medina, which, along the Niagara River, admits of a number of subdivisions, which 

are, however, of only local significance.a The total thickness is nearly 125 feet, with 25 feet 

of white quartzose sandstone (Whirlpool sandstone) at the base and about 8 feet of a similar 

sandstone at the top. The middle series consists of red sandstones and green and gray sandstones and shales. The red sandstones generally show eolian cross-bedding and appear to have 

accumulated above water. The green sandstones and shales are fossiliferous. The white 

Whirlpool sandstone exhibits beach features b and probably marks the advance of the sea, 

though it is likely that the sand was originally dune sand, as suggested by A. W. G. Wilson. 

The fossils are generally most abundant in the shales and thin-bedded sandstones. The 

heavy-bedded sands are either free from fossils or have only scattered shells of Lingulre. At 

Lockport and elsewhere some layers are crowded with gastropod shells. 

A list of fossils from the Medina follows, and Grabau continues: 

This is a Lower Siluric [lower "Upper Silurian"] fauna, and favors more especially the 

Clinton and Rochester faunas. It is so far known only from western New York, with the exception of Arthrophycus harlani, which is widely distributed. In western New York this species 

occurs at the top of a heavy-bedded unfossiliferous sandstone with an eolian tYPe of crossbedding, and just below the upper white quartzite. In east-central New York it is found at the 

base of the Oneida conglomerate, which is the approximate equivalent of the upper white sandstone of Niagara. In the Appalachians it is found mostly in the upper part of the Tuscarora and 

Clinch sandstones, the stratigraphic equivalent of the Medina. * * * 

The Tuscarora has a thickness of 820 feet in Logan's Gap, Jack's Mountain, Mifflin County, 

Pa., but thins perceptibly westward and southward, being 400 to 500 feet thick in Bald Eagle 

Mountain and 287 feet in Wells Mountain and the Pennsylvania-Maryland line. This thinning 

appears to be due to failure of the lower beds, showing a true case of nonmarine progressive 

overlap. In New York the upper part is represented by the true Medina, which has a thickness 

of 125 feet and begins and ends with a pure white quartz sandstone. More strictly speaking, 

the upper 'vhite sandstone alone represents the true Tuscarora, but the lower beds, still partly 

red, and the shales probably are the equivalent of the lower reddish sandstones and greenish 

shales underlying the true white Tuscarora, and sometimes referred to the Upper Juniata. The 

Oneida conglomerate of central New York, 40 feet thick, is likewise the representative of the 

upper part of Tuscarora, though it may have had a more local origin. * * * 

The Clinton shales succeed the Oneida conglomerate in Oneida and Herkimer counties, 

N. Y., and the Upper Medina quartzite in western New York. In the southern Appalachians 

a See Bull. New York State Mus. No. 45, pp. 88-95. 

b Fairchild, H. L., Am. Geologist, vol. 28, 1909. 
238 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

the series is largely composed of sandstones (Rockwood), highly impregnated with iron and 

often containing beds of workable iron. It is generally succeeded by late Siluric (Monroan) 

or by Helderbergian or later beds, there being a pronounced disconformity at the summit of 

the Rockwood throughout. That part of the series in Virginia is of continental origin is indicated by the general character of the rocks, but marine intercalations are not uncommon. In 

some cases in eastern Tennessee the iron ore itself is fossiliferous, having replaced a marine limestone. In such cases the bulk of the formation is shale. In no case is the original thickness 

preserved, since the formation is everywhere bounded above by an erosion plane. In northern 

Virginia to-day the thickness is 7 50 feet (Piedmont folio), and not over 400 feet in southern 

Virginia. In southern Tennessee and northern Georgia it is from 1,100 to 1,600 feet thick, 

decreasing westward and northward. With our present knowledge of the formations, it is safe 

to say that the eastern sandy phase represents near-shore deposits, if not actually continental 

conditions, formed probably at the embouchures of several Appalachian rivers; and that westward these deltas merged gradually into true marine deposits, mainly sands and clays, with 

some limestones intercalated. That the Rockwood represents more than the Clinton of New 

York can not be questioned. Where the series is developed in its totality, it probably represents the entire Niagaran, if not a part of the Salinan as well. Along the Allegheny Front 

fossiliferous shales and iron ores represent this series, with a thickness of not less than 1,000 

feet, on the western branch of the Susquehanna. The lower series, 700 feet thick, consists mainly 

of fissile shales, including an iron sandstone, and with Buthotrephis in the upper part. This is 

succeeded by 110 feet of calcareous fossiliferous shales; and this by 230 feet of fossiliferous 

shales and limestones with a Niagaran fauna. Above this follows 350 feet of red shales, probably representing the Upper Salina and separated by a hiatus from the fossiliferous Niagaran 

shales. 

In eastern New York, at Swift's Creek, the type locality for the Clinton, this formation is 

226 feet thick and is followed by 5 feet of Niagaran and then by the red shales of the Upper 

Salina. On the Niagara River the Clinton shale with the two succeeding limestones has a total 

thickness of 32 feet, followed by 68 feet of Rochester shale. The total of the Niagaran, including the Guelph, is from 270 to 325 feet, as shown by borings. This is followed by Lower Salinan. 

In the Rochester region the Clinton has a thickness of 80 feet, including the Irondequoit or upper 

limestone (17 feet), which Chadwick refers to the Rochester. The eastward thinning of the 

Upper Niagaran beds indicates either that these beds were eroded before the deposition of the 

red shales, probably during the Shawangunk epoch, or that the Rochester-Lockport of the west 

is in part represented by Upper Clinton in the east. The Guelph element may never have 

extended to the Clinton typl;l region, which may have been above water and so subject to 

eroswn. 

Local details are given in papers by Darton, 222-

225 Ries, 672 Clarke, 156 Grabau, 378• 

380 

Hartnagel, 409-

412 and Merrill 592 published in the New York State reports and 

elsewhere. 

A critical and comprehensive report on the Silurian formations in New Jersey 

has been made by Weller. ssob The following is a condensed section of the formations which he distinguishes from the base up. 

Shawangunk conglomerate: Coarse quartz conglomerate, of white or yellowish pebbles 

in a gray or red matrix; unfossiliferous; unconformable on Hudson (Ordovician) -shale. 

Medina-Longwood sandstone: Soft, often somewhat shaly, and deep red; unfossiliferous. 

Poxino Island shale: Greenish, calcareous, unfossiliferous ............................ . 

Bossardville limestone: Fine-grained, compact bluish-gray banded limestone, unfossiliferous ........................................................................ . 

Decker Ferry formation: Sandstone with thin calcareous beds or limestone with some 

thin bands of greenish shale; highly fossiliferous; divided into three faunal zones and 

the uppamost into three subzones; correlated with the "Coralline" (Niagaran) limestone of eastern New York; presumably contemporaneous with but faunally not closely 

related to the Niagara limestone of the Mississippi Valley ........................... . 

Feet. 

1,500-1,600 

2,300-2,400 

1-200 (?) 

12-100 

50 
SILURIAN. 

Rondout formation: Shales and earthy limestones; sparsely fossiliferous; name restricted 

to the upper cement bed of the section at Rondout ................................ . 

Manlius limestone: Thin bedded, knotty, dark blue to black; fauna limited, exhibits 

from base to summit a passage from life conditions suitable only for Leperditia to normal 

marine conditions; gradual transition from Rondout faunally and stratigraphically; 

pronounced faunal break in passing to the overlying Coeymans (basal Helderbergian) 

Devonian limestone ............................................................. . 

Feet. 

39 

35 

4,424 

239 

The Silurian rocks described by Weller extend into Pennsylvania, but with 

changes which are described in great detail in the county reports of the· Second 

Geological Survey of Pennsylvania under the names Lewistown limestone, Bloomsburg shale, and Bossardville limestone. The facts are assembled by Lesley.535 A 

typical section, which shows the great thickness of strata and their intimate lithologic similarities or gradual changes, is that of Logan Gap, Mifflin County, in the, 

central part of the State. The descending section is summarized by Lesley 535a as 

follows: 

j. Salina gray shale ..................................................................... . 

;: ~~~:: ~::s~~~: ~~~~~} 423 feet. ....................................................... { 

m. Logan shale .......... . 

n. Salina upper red shale ............................................................... . 

o. Salina upper lime shale ............................................................... . 

p. Salina lower red shale ................................................................. . 

;: ~~i~~~~ ~;;:r !~~e :~~~~}- · · · · · · · • · · · • · · · · · · · · · • · · · • · · · · · · · · · · · · · · · · • · · · · • · · · · · • • • • • 

s. Ore sandstone and ore beds ............................................................ . 

t. Clinton middle olive shale ............................................................. . 

u. Iron sandstone ........................................................................ . 

v. Clinton lower olive shale ............................................................. . 

Feet. 

164 

348 

3! 

72 

432 

326 

272 

251 

38 

178 

7 

571 

w. Medina white sandstone................................................................ 820 

x. Medina red sandstone and shale..................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,280 

y. Oneida red conglomerate............................................................... 309 

z. Oneida gray sandstone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313 

a. a. Hudson River slates. 

5,384 

The Silurian rocks recogmzed in New Jersey have been traced southward 

through Pennsylvania. The strata become thinner to the south. The unconformities observed in New York and New Jersey at the base of the Silurian are not noted 

in the Pennsylvania sections, where the basal gray sandstone succeeds the Martinsburg ("Hudson River") shale (Ordovician) in apparent conformity. 

The littoral and calcareous marine strata which constitute the Silurian in 

Pennsylvania pass across Maryland into Virginia. They have been described by 

Prosser M~ and O'Harra.~ 19 The section, which measures 2,200 to 2,400 feet in thickness, is fully described and correlated by Prosser, the following being a condensed 

section of the subdivisions recognized by him, from the base up: 

Juniata formation: Alternating beds of shale and sandstone, deep red, unfossiliferous, prob- Feet. 

ably equivalent to the older part of the Medina of New York........................... 550+ 

Tuscarora formation: Quartzose sandstone, white to light gray; Arthrophycus harlani . ....... 250-300 

('linton formation: Shales, yellowish green to red, with thin fossiliferous limestones in upper 

part, and two beds of iron ore ......................................................... 550-600 

Niagara formation: Thin-bedded blue limestone with thin shale partings, becoming shaly 

and blackish above; represents the Decker Ferry formation of New Jersey and is equivalent in time to Rochester shale and Lockport limestone or Niagara of New York ......... 250-300 

Salina formation [Cayuga group]: Shales, impure limestones including four cement beds, 

and sandstone, gray and blue, sparsely fossiliferous..................................... 700 
240 INDEX TO THE STHATIGRAPHY OF NORTH AMEIUCA. 

The overlying Helderberg limestone is assigned by Prosser to the Devonian. 

The Silurian of New Jersey has also been described by KfunmeP13b as follows: 

Contrary to long prevalent and apparently well-established belief, the lower and middle 

portions of the Silurian system are not represented in New Jersey. Their absence in this and 

adjoining regions is indicative of somewhat widespread earth movements unaccompanied in 

this region by folding, which closed the period of deposition indicated by the Martinsburg 

sediments or possible overlying beds afterwards removed by erosion and raised the region 

above the zone of sedimentation. When deposition began again, late in Silurian time, beds of 

coarse conglomerate were laid down, followed by sandstones, shales, and limestones, the earlier 

sediments being those of a low-grade delta in an arm of the Appalachian gulf. a These condi· 

tions of deposition prevailed with but slight changes of elevation into Devonian time. 

The Shawangunk conglomerate (the Oneida conglomerate of many previous publications) 

i-s chiefly a coarse quartzite and conglomerate composed of small white-quartz pebbles embedded 

in a siliceous matrix. Its color is generally steel-blue, but some beds have a yellowish tinge 

and reddish layers occur near the top. Layers of black shale a few inches in thickness are 

locally intercalated between thick beds of conglomerate and grit. Between this formation 

and the Martinsburg shale there is a gap representing the upper part of the Ordovician and all 

of the Silurian below the Salina of the full New York section, but there is no marked divergence 

of dip and strike where the two formations outcrop in proximity, and the actual contact is 

nowhere exposed in New Jersey. The beds overlying the Shawangunk conglomerate are red 

sandstone and shale, and the transition from the Shawangunk is made through a series of 

alternating red sandstone and gray conglomerate, so that the upper 'limit of the Shawangunk is 

not sharply defined. Its thickness is probably from 1,500 to 1,600 feet. 

So far as known, the formation is barren of fossils in New Jersey, but at Otisville, N.Y., 

a eurypterid fauna has been found in the black shale intercalated with the conglomerate. In 

the Otisville section this fauna, which elsewhere appears only and briefly at the base of the 

Salina, repeats itself many times through a thickness of 650 feet.a The Shawangunk conglomerate is followed by 2,500 feet or more of shales and limestones also referable to the Salina; 

hence for this region it represents only the lower portion of that group. 

The red sandstone and shale which immediately overlie the Shawangunk conglomerate 

have until recently been regarded as the equivalent of the Medina sandstone of New York and 

have been so called, but, for the reasons just cited, it is evident that they are much younger 

than Medina and that they must be included in the Salina group. Moreover, they lie some 

distance below a limestone which is correlated with the Cobleskill of the New York section. 

The name High Falls has been applied to the red shales that overlie the Shawangunk conglomerate in Ulster County, N. Y., and has been adopted for New Jersey in place of Medina, 

which is not applicable. 

The lower beds consist of a hard red quartzitic sandstone, intercalated with some green or 

gray sandstones and softer red shales which become more abundant in the upper part of the 

formation. The formation has an estimated thickness of 2,300 feet at Delaware Water Gap. 

It is not known to contain fossils, but its age is fixed by its stratigraphic position. 

The formation known as the Green Pond conglomerate occurs in an isolated belt of Paleozoic 

rocks which extends through the middle of the pre-Cambrian Highlands of New Jersey. In 

constitution it is similar to the Shawangunk conglomerate, with which it is correlated, but, 

inasmuch as it is still an open question whether the Paleozoic strata of the Green Pond Mountain 

region were once continuous with the great mass of Paleozoic sediments which lie some distance 

to the northwest, or whether the Green Pond region represents a separate basin shut off on the 

northwest from the large Paleozoic sea although communicating with it to the northeast, it 

has seemed best to retain for the present at least both Shawangunk and Green Pond as names 

for these conglomerates in their respective fields. 

a Clarke, J. M., Bull. New York State Mus. No. 107, 1907, p. 303. 
SILURIAN. 241 

Immediately above the Green Pond conglomerate, and conformable with it, is a soft red 

shale [Longwood shale], in which an irregular cleavage is usually so highly developed that the 

bedding planes can be determined only with diHiGulty. The formation is not known to contain 

fossils, but, as it rests directly upon the Green Pond conglomerate and is followed by a limestone carrying a Salina fauna, it is probably of Salina age. Its stratigraphic position is, in 

general, the same as that of the High Falls formation, but the two may not be exactly 

svnchronous. 

• The higher Silurian and the Devonian formations of New Jersey occur either in Wallpack 

Ridge, which lies along the northwestern border of the State in the upper Delaware Valley, or 

in the narrow belt of Paleozoic rocks in the midst of the highlands in the Green Pond Mountain 

region. In Wall pack Ridge they aggregate 1,300 feet or more, while in the Green Pond 

:Mountain region they have a thickness of about 4,000 feet, of which all but 250 feet are 

referable to beds higher than any of those along Wallpack Ridge. 

The top of the High Falls shale in New Jersey is everywhere buried by glacial drift which 

also conceals the beds immediately superjacent. The next recognizable formation is the 

Poxino Island shale, a buff or greenish calcareous shale in thin layers and nonfossiliferous so far 

as known. Its outcrops along the base of Wallpack Ridge in the upper Delaware Valley are 

few, small, and widely separated, and very little is known regarding it. In the adjoining 

portion of Pennsylvania it is reported to be 200 feet in thickness and to rest on a thin limestone 

formation which in turn rests on the High Falls shale. It is not known to occur in the Green 

Pond Mountain region. 

A fine-grained, compact bluish-gray banded limestone, known as the Bossardville limestone, lies conformably upon the Poxino Island shale in Wallpack Ridge. It increases in 

thickness from 12 feet at the New York State line to about 100 feet where it crosses the Delaware River into Pennsylvania. Owing to its marked banding it was for many years known as 

the "Ribbon" limestone and was correlated by Cook and later geologists with the Ribbon or 

Manlius limestone at Rondout, N.Y. In reality it lies below the Manlius limestone. It is only 

sparingly fossiliferous but is immediately succeeded by a series of beds containing a well-defined 

Salina fauna. It has not been recognized in the Green Pond Mountain belt, but this may be 

from lack of exposures. 

Under the name Decker Ferry formation a series of beds has been described, which are 

chiefly limestones at the north and calcareous sandstones at the southwest. Their thickness is 

52 feet at the Nearpass quarry near Tristates, where the section can be accurately measured. 

Thin bands of more or less fissile green shale separate the limestone beds. A thin band of red, 

crystalline, highly fossiliferous limestone occurs about the middle of the series and is !!. striking 

feature. The lower 42 feet of these beds as exposed at the type locality are correlated a with 

the Wilbur limestone (the so-called "Niagara" or "Coralline" limestone of Hall and other 

authors) and the "black cement" beds-that is, the Salina "water lime" of the Rondout section 

of New York. These form the top of the Salina group, the base of which in New Jersey is the 

base of the Shawangunk conglomerate. The upper 10 feet of the Decker Ferry series contain 

fossils, particularly in the lower half, which render necessary their correlation with the Cobleskill 

limestone of eastern New York. 

In the Green Pond Mountain region isolated outcrops of impure limestone occur a short 

distance above the Longwood shale, which contain a fauna that correlates them with the lower 

beds of the Decker Ferry formation-that is, to the part referable to the Salina group. 

Along the upper Delaware the beds immediately above the Decker Ferry limestone and 

referred to the Rondout consist of more or less earthv shales and limestones the thickness of 

which is 39 feet. They are usually only sparingly fossiliferous, alti10ugh in some beds the 

crustacean Leperditia is abundant. A typically marine fauna, with an abundance of brachiopods, trilobites, etc., is conspicuously absent in these beds. In general lithologic features 

this formation resembles the Rondout as developed in New York State, but the cement beds 

which are so characteristic of this formation farther north are not present here. 

a IIartnagel, C. A., Dull. New York State Mus. No. 69, 1903, p. 1152. 

48011°--12----16 
242 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

'fho Rondout is succeeded conformably by a somewhat thin bedded, knotty dark-blue or 

almost black limestone, 34 to 35 feet thick where best exposed. It is the bed which constitutes the quarry stone of the Wallpack Ridge and its outcrop is marked by a line of quarries 

and limekilns. It is referred to the Manlius or "Tentaculite" limestone of the New York 

series, although well-preserved specimens of the characteristic fossil Tentaculites gyracanthus 

Eaton are rare. In the lower beds there is evidence of environmental conditions similar to 

those of the Rondout. In the middle portion Leperditia is still abundant but is associated 

with a prolific brachiopod fauna, suggestive of the recurrence of more typical marine conditions. In the upper beds Leperditia has entirely disappeared and the fauna is normally marine. 

No beds referable to the Rondout or Manlius have been detected in the Green Pond Mountain 

region, although their attenuated representatives may occur. 

K 10. TAYLORSVILLE DISTRICT AND KLAMATH MOUNTAINS, CALIFORNIA. 

The Paleozoic section of the Taylorsville district, in the Sierra Nevada just 

north of the fortieth parallel, comprises at the base the Grizzly formation ( 400 feet, 

possibly Ordovician), the Montgomery limestone (10 to 60 feet), and the Taylorsville formation (1800 feet). The Montgomery limestone has yielded fossils which 

Walcott determined as representir~g the "Niagara horizon of the Mississippi Valley 

and Appalachian provinces." ma 

In the Klamath Mountain region the Abrams and Salmon fo:.·mations of 

Hershey435 are assigned by Diller 276b to a pre-Devonian age, as they are older than 

the fossiliferous Devonian. 

The Silurian area of the Taylorsville district is too small to show on the scale 

of the map of North America. 

K 15-16, L 16. IOWA, NORTHERN ILLINOIS, AND WISCONSIN. 

Chamberlin and Salisbury 134c have compiled the following section of the 

Silurian of Iowa from the reports of the Iowa Geological Survey: 

Formations. 

Anamosa limestone ............ . 

LeClaire limestone ............ . 

Delaware stage ................ . Unconformity. 

Silurian formations of Iowa. 

Thickness I 

(feet). Characteristics. 

----------------------------------------------

50-75 Soft, granular, evenly bedded dolomite; white to buff and gray; 

important building stone. 

50 MassiVe or heavy-bedded, highly crystalline dolomite. Upper surface 

undulating; cross-bedded on a large scale. 

200 Limestone containing large quantities of chert. 

The middle formation of the section is described by Samuel Calvin 116 as follows: 

The Le Claire limestone constitutes the second stage of the Niagara formation as it is 

developed in Iowa. The first or lower stage has been called the Delaware, from the fact that 

all its varying characteristics are well exhibited in Delaware County. The Delaware stage 

embraces many barren beds and presents a very great number of phases, but at certain horizons 

it abounds in characteristic fossils. The typical faunas of this lower stage embrace such forms 

as Pentamerus oblongus Sowerby, Halysites catenulatus Linnreus, Favosites favosus Goldfuss, 

Strombodes gigas Owen, Strombodes pentagonus Goldfuss, Ptychophyllum expansum Owen, and 

Diphyphyllum multicaule Hall. The beds of the Delaware stage furthermore contain large 

quantities of chert. 
SILURIAN. 243 

The Le Claire stage of the Niagara follows the Delaware. The exact line of separation 

between the two stages has not been and probably can not be definitely drawn. There are 

massive, barren, highly dolomitized aspects of both stages that, taken by themselves, can not 

be differentiated in the field. Under such circumstances the observer must work out the 

stratigraphic relations of the particular group of strata under consideration before referring it 

to its place in the geological column. In general the Le Claire limestone is a heavy-bedded, 

highly crystalline dolomite. It contains scarcely any chert, and in the lower part there are 

very few fossils. There are occasionally a few specimens of Pentamerus, of the form described 

as Pentamerus occidentalis Hall, and the principal coral is a long, slender, tortuous Amplexus 

which is represented only by casts of the vacant or hollow parts of the original corallum. On 

account of the complete solution of the original structure, the spaces occupied by the solid parts 

of the corallum are now mere cavities in the limestone. In the upper part of the Le Claire stage 

small brachiopods abound. They belong to the genera Homeospira, Trematospira, Nucleospira, 

Rhynchonella, Rhynchotrepa, Atripa, Spirifer, and probably others. In most cases the fossils 

have been dissolved out, leaving numerous cavities. The calcareous brachial apparatus of the 

spire-bearing genera is often the only part of the original structure represented. No statement 

can well give any idea of the numbers of the small shells that crowded the sea bottom near the 

close of the LeClaire stage, nor of the corresponding number of the minute cavities that are now 

so characteristic a feature of this portion of the LeClaire limestone. In some localities in Cedar 

County the small brachiopods of this horizon are represented by very perfect casts that were 

formed by a secondary filling of the cavities left by solution of the original shell. The external 

characters are thus fairly well reproduced. 

Compared with the beds of the Delaware stage, the LeClaire limestone as a rule lies in more 

massive ledges, it is more completely dolomitized, and its fracture surfaces exhibit a more perfect 

crystalline structure. It contains an entirely different fauna, a fauna in which small rhynchonelloid and spire-bearing brachiopods are conspicuous. Its fossils are never silicified, and, in marked 

contrast with some portions of the Delaware, its upper part at least is notably free from 

chert. * * * 

The Le Claire limestone is in some respects unique among the geological formations of 

Iowa. In the first place it varies locally in thickness, so much so that its upper surface is exceedingly undulating, the curves in some pla.ces being very sharp and abrupt. In the second place 

it differs from every other limestone of Iowa in frequently exhibiting the peculiarity of being 

obliquely bedded on a large scale, the oblique bedding often affecting a thickness of 15 or 20 

feet. The phenomena suggest that during the deposition of the Le Claire limestone the sea 

covered only the southwestern part of the Niagara area, that at times the waters were comparatively shallow, and that strong currents, acting sometimes in one direction and sometimes 

in another, swept the calcareous mud back and forth, piling it up in the eddies in lenticular 

heaps or building it up in obliquely bedded masses over areas of considerable extent. The 

oblique beds observe no regularity with respect to either the angle or direction of dip. Within 

comparatively short distances they may be found inclining to all points of the compass. Again 

the waters at times were quiet, and ordinary processes of deposition went on over the irregular 

sea bottom, the beds produced under such circumstances conforming to the undulating surface 

on which they were laid down. 

In Illinois and Wisconsin the Silurian is known simply as the Niagara dolomite 

or limestone, the formation varying in lithology in different areas. The formation 

in Illinois is thus described by Bain: 51a 

Above the soft shale of the Maquoketa is a fine-grained dolomite, carrying more or less 

chert. This forms the uppermost member of the stratigraphic section in this area. The beds 

in the lead and zinc district form only the lower portion of the great thickness of strata which 

have long been known collectively as the "Niagara." There is no established local name for 

these particular beds, and since they were doubtless formed at some time within the "Niagara" 
244 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

epdch the group term will be provisionally used for them. * * * A thickness of 150 feet 

is present. 

* * * * * * * * * 

The '' ~iagara" dolomite is distinguished from that of the Galena not only by the occurrence 

of certain characteristic fossils, of which Halysites catenulatus is probably most widespread and 

easily recognized, but also by fairly constant lithologic differences. In general, the "Niagara" 

is much lighter colored, finer textured, and is relatively free from the small irregular cavities 

which mark the Galena. 

K-L 12. SOUTHWESTERN MONTANA AND WESTERN WYOMING. 

Silurian strata may be absent in southwestern Montana and western Wyoming. 

They have not been identified by their fauna. In general the Cambrian, or the 

Ordovician where present, is succeeded by Carboniferous, but the Jefferson limestone (Devonian) intervenes in some sections and is underlain by strata that appear 

to represent the Silurian in seemingly conformable sequence. 

Kindle 499a studied the distribution of the Jefferson limestone (seep. 320, Chapter VI) and discusses the Silurian in certain sections. For the section on Boulder 

Creek, west of Princeton, Mont., in the Philipsburg quadrangle, he says: 

No fossils were procured from the 200 feet of beds [gray to brownish shale and sandstone, 

the latter predominant at the base] at the base of the Jefferson limestone, so that the age of the 

beds intervening between the Cambrian and Devonian faunas remains undetermined in this 

region. No evidence of any stratigraphic break in this part of the section was observed. 

About 20 miles south of Princeton, on the east fork of Rock Creek, the Jefferson 

limestone occurs immediately above the following beds: 

Feet. 

E. Shales and covered. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 

D. White limestone .................................................................. ~...... 5 

C. Brownish arenaceous thin-bedded magnesian limestone ..................................... 90 

B. Limestone [Upper or late Middle Cambrian]. 

The beds C, D, and E represent both Ordovician and Silurian, unless there is 

an undetected hiatus. Kindle says: 

No fossils were obtained from the beds separating this formation [Cambrian] from the 

Jefferson in either the Rock Creek or Boulder Creek sections. These beds, measuring 210 feet 

in thickness in the Boulder Creek section and 125 feet in the Rock Creek section, may provisionally be referred to the Silurian. 

In southwestern Wyoming occurs a similar sequence of Cambrian limestone, 

unfossiliferous strata, possibly Silurian, and a limestone correlated with the Jefferson. Describing a section near Viola, Wyo., Kindle says: 

We are without positive information regarding the age of the 700 feet of gray limestones 

below the saccharoidal limestones of the Jefferson. These beds may be in part of the same 

formation and age as the 40 feet of limestone at their base, the age of which is known by fossils 

to be Cambrian. It seems probable, however, that Silurian or Ordovician strata, or perhaps 

both, may be included in the series. The Ordovician is present in the Bighorn Mountains to the 

north, and both are present in northeastern Utah. 

K-L 17-18. ONTARIO AND WESTERN NEW YORK. 

The belt of Silurian strata which extends from Georgian Bay to western New 

York comprises the Clinton and other subdivisions of the Niagara, together with 

the Medina, below the Clinton, and several formations above the Niagara. The 
SILURIAN. 245' 

latter are not uniformly extensive. In Canada they include the "Onondaga Salt 

group" and the ""Water lime" (Bertie or Cayug3 dolomite of ,Chapman136), which 

was referred by Logan 470• 5440' 919 to the "Lower Helderberg" but is now regarded 

by Clarke as a member of the Salina formation. ' 

In New York the Guelph dolomite, the uppermost formation of the Niagara in 

Canada, has a restricted extent only. 158 The "Onondaga Salt group" (called 

Salina by Dana 215) and the "Water lime" are now included in the Cayugan, the 

recognized subdivisions 159 of which are known as Salina formation, Cobleskill limestone, Rondout water lime, and Manlias limestone. Their relations and the western 

representatives of the formations of New York are discussed by Grabau. 377 In this 

part of Canada the "Lower Helderberg" of Logan and Chapman comprises only a 

part of the" Water lime" which in central New York underlies the strata which were 

formerly known as "Lower Helderberg" but which are now called Helderberg or 

Helderbergian and assigned to the Devonian. 159a Merrill, whose geologic map of the 

State 592 has (generally) been followed in the map of North America, placed the line 

between Silurian and Devonian at the top of the "Lower Helderberg." TheN orth 

America map of 1906 followed this delineation. The present map does not depart 

therefrom, for the scale is too small to show the difference, but the Helderberg 

("Lower Helderberg") is included in the Devonian in the citations contained in this 

volume. 378, M2, 111a, 933 

L 16-17. NORTHERN MICHIGAN AND ONTARIO. 

There seems to be some question as to the presence of the Clinton in Michigan. 

Certain beds which have been referred to by several authors as Clinton are, in the 

opinion of Ulrich, more likely to prove of Richmond age. Aside from these doubtful 

beds the Silurian consists of the dolomitic limestones commonly referred to the 

Niagara and the divisions which have been grouped by Lane and others under 

the term Monroe. Of the Niagara as mapped by the Michigan State Survey and 

others Lane 517 recognizes the following subdivisions: Clinton, 0 to 130 feet; 

Rochester shale, doubtfully identified, 20 to 30 feet; Lockport and Guelph dolomites, 270 to 600 feet, the greater thickness being in the northern part of the State. 

The two latter Lane combines under the name Manitoulin. 

Rominger 677 describes the "Niagara" of the Upper Peninsula of Michigan in 

detail for different localities and sums up the section as follows: 

The rock beds of the Niagara group allow a subdivision in three well-marked sections. It is 

exclusively a limestone formation. The lower section is always very regular and even-bedded, 

composed of comparatively thin layers of a fine crystalline grain, or with a dull, more earthy 

fmcture. In composition most of the strata are dolomites; only a few layers are found to be a 

pure limestone. Fossils are rare in it. The middle division is made up by more massive, highly 

crystalline dolomite ledges, which usually contain a large number of the casts of the Pentamerus 

oblongus and some ill-preserved corals. The upper division is a series of thin, uneven layers, with 

intermixture of much siliceous matter with the dolomite mass, and of seams and nodular concretions of hornstone. In this upper division, also, the greatest abundance of fossils is found. 

With reference to the "Niagara" of Manitoulin Island, Bell 67 a states: 

The southern portion of the peninsula between South Bay and the eastern side of Manitoulin 

Island belongs to the Niagara formation, which has here a thickness of about 405 feet. It consists principally of heavy-bedded light-gray, light bluish-gray, and buff dolomites. Good fossils 
246 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA" 

are rare, although much of the rock is made up of comminuted fragments of organic remains" 

The thicker beds are rendered somewhat porous by the numerous small cavities left between 

these fragments" Most of the beds show a crystalline character on fresh fracture. 

* * * * * * * On the south end of Fitzwilliam Island and on the eastern part of the south shore of Manitoulin Island there is a thickness of about 100 feet of heavy-bedded, coarsely spongy gray and 

buff dolomite, which contains a few fossils like those of the Guelph formation. 

Monroe is a term formerly applied by Lane to all the Silurian above the "Niagara" (that is, betwc:;en the "Niagara" and the Dundee limestone), as he found it 

impracticable to separate the strata consistently" Although a division can not be 

made distinctly in the field, Lane 517 now recognizes the following subdivisions, in 

ascending order: Salina, or Lower Monroe; Bass Islands series, or Lower Monroe [in 

the restricted sense]; Sylvania sandstone, or Middle Monroe; and Detroit River series, 

or Upper Monroe" He discusses their thickness and character at length" 

The " Salina" he defines as extending from the top of the "Niagara" to the 

uppermost salt bed" The base of the "Salina" should be marked, according to 

Grabau, as quoted by Lane, by a hiatus and "disconformity"" According to Lane 

the strata thicken greatly northward from Monroe County, presumably by the addition of beds at the bottom in the deeper part of the basin" At Milan rock salt seems to 

occur almost directly above the "Niagara," whereas at Wyandotte there is 275 feet 

of dolomite below the rock salt and above the white dolomite" 

The top of the "Salina" Lane would determine by measuring from the Sylvania 

sandstone down to the top of the first salt bed" He would then class all the beds 

between that stratum and the "Niagara" below as "Salina"" He thus obtains 

thicknesses for the "Salina" which range from 370 feet (at Britton) to 959+ feet (at 

Royal Oak)" Inasmuch, however, as the salt bed thus determined is by no means 

certainly at one horizon, and gypsum if not salt occurs above the Sylvania sandstone, 

the division is very indefinite and of little stratigraphic significance" 

Although the top of the "Salina" is thus difficult to determine, it is made the 

base of a division which comprises all the Silurian above the "Salina" and which in 

distinction to that formation is strictly marine" Unfortunately the name" Monroe" 

has been given to this division in a limited sense excluding the "Salina," in contrast 

to the broader definition including "Salina," which has become established" This 

limited "Monroe" has been subdivided into three parts and the upper and lower of 

these each again into four members" Lane, Prosser, Sherzer, and Grabau 518 have 

published the following: 

MONROE FORMATION. 

The highest Siluric strata of America are represented by the Monroe formation of Michigan, 

using this term in its limited sense for the' post-Salina Silurico The Monroe formation is a 

strictly marine series succeeding the abnormal (nonmarine [Grabau]) Salina" It is traceable 

throughout lower Michigan westward into Wisconsin and eastward through Ohio, Ontario, and 

into western New York Where recognizable a strong dividing line separates the lower from the 

upper part, and in general this division is emphasized by the occurrence of the Sylvania sandstone, a rock of pure quartz grains, and representing, according to Grabau and Sherzer, an 

eolian deposit formed under conditions similar to those now found in the Libyan Desert" According to this interpretation, the Sylvania sandstone represents a long time interval the depositional 

marine equivalent of which is still unknown. This long interval is further emphasized by the 

entire distinctness of the faunre of the lower and upper divisions of the Monroe" 
SILURIAN. 247 

The subdivisions recognized so far in the Monroe, with their faunal characteristics (determined by Grabau), are as follows: 

LOWER MONROE. 

For this stratigraphic unit the name Bass Islands series is proposed, from the group of 

Islands of that name in western Lake Erie. No other appropriate term seems to be available, 

though characteristic exposures of all the divisions are not found in these islands. 

(a) Greenfield dolomite.-This term was proposed by Grabau in 1898, though previously used 

in a commercial sense, for the dolomite found about Greenfield, Highland County, Ohio, and 

exposed again in the regions about Ballville, in northern Ohio. The name is here accepted for 

this division, which is characterized by Schuchertella hydraulica (Whitfield), Hindella? whitfieldi Grabau, H.? rostralis Grabau, Leperditia, etc. The faunal zone may be called that of 

Schuchertella hydraulica. The thickness is 100 feet or more and the formation is the lowest known 

subdivision of the Monroe. 

(b) Tymochtee shales and limestones.-This name was proposed in 1873 by N.H. Winchell for 

the shales and thin-bedded calcilutytes of the Monroe (Waterlime) series exposed in the creek of 

that name in Crawford Township, Wyandot County, Ohio. The thickness there is something 

over 100 feet, but the relation to the overlying and underlying formation is unknown. Its 

fauna likewise is unknown, and the formation must be considered a tentative division of the· 

Lower Monroe. It is not impossible that it represents in part one or more members recognized 

elsewhere. 

(c) Put-in Bay dolomites.-This name is proposed for the extensive fossiliferous series of 

water lime exposed on Put-in Bay Island, one of the Bass Islands, and characterized by the 

fauna comprising Spirijer ohioensis Grabau, Goniophora dubia Hall, Eurypterus eriensis Whitfield, and Leperditia. From the abundance of the pelecypod, the paleontologic zone may be 

called that of Goniophora dubia. Something over 100 feet of strata is exposed on Put-in Bay 

Island, where the higher beds are in contact with the succeeding zone. The formation is also 

known from Marion County, Ohio. Its thickness is over 100 feet, but the base is unknown. 

(d) Raisin River dolomites.-This name is proposed for the highest division of the lower 

Monroe exposed in Lucas and Wood counties, Ohio, and in Monroe County, Mich., especially along 

the Raisin River. It is perhaps 200 feet thick and contains several oolite zones. Its known 

fauna comprises nearly 20 species, of which the most significant are Whitjieldella prosseri Grabau 

and Pterinea lanii Grabau. These are restricted to this horizon, so far as known. Spirorbis 

laxus and numerous minute gastropods, besides plant remains, further characterize this horizon. 

From the abundance of the brachiopod mentioned, which is everywhere found and characteristic, 

the faunal zone is designated as that of Whitjieldella prosseri. 

MIDDLE MONROE. 

This is represented in Michigan only by the Sylvania sandston<~. This is believed to represent a long interval at the end of which a new series of faunre invaded this region upon 

resubmergence. The thickness of the Sylvania seldom exceeds 150 feet. 

UPPER MONROE. 

For this stratigraphic unit the group name Detroit River series is here proposed, from the 

exposure of all its members along that stream. It comprises four subdivisions or faunal zones. 

(a) Flat Rock dolomites.-These are exposed at Flat Rock, on the Huron River, and are 

also found in the lower part of the salt shaft at Oakwood, near Detroit. The fauna so far 

obtained is meager, comprising only the corals Syringopora cooperi Grabau, S. cf. hisingeri 

Billings, and Favosites cf. maximus Troost. The first mentioned seems to be characteristic 

and restricted to it, and the zone is provisionally called the Syringopora cooperi zone. The 

thickness of the formation varies from 40 to 150 feet or more. 

(b) Anderdon limestone.-This name, suggested by the Rev. Thomas Nattress, was adopted 

by Sherzer and Grabau for the coral reef limestone exposed in the Anderdon quarry, Essex 

County, Ontario, 2 miles from Amherstburg, Ontario, and in the salt shaft at Oakwood, Detroit. 
248 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. . I, 

Its thickness is from 40 to 50 feet and its faun~ a rich coral and Stromatopor~ fauna. It varies 

from a pure calcilutyte to' a moderately coarse calcarenyte. Six sp~cies of stromatoporoids 

and- eleven of coral have bQen determined by Grabau. Among the former Stylodictyon sherzeri 

Grabau and Idiostroma nattressi Grabau are characteristic and restricted. From the abundance 

of the latter the faunal zone may be named the Idiostroma nattressi zone. Favosites of Dev~nic 

affinities are characteristic. 

; (c) Amherstburg bed.-This name is proposed by Sherzer and Grabau for the next higher 

stratum, a dplomite not over 20 feet thick and forming a transition zone to the overlying Lucas. 

Tlus zone is rich in fossils, 52 species having been identified by Grabau, most of them being 

new and of Devonic affinities. The fauna unites the Anderdon and Lucas elements to a certain 

degree. Panenka canadensis Whiteaves, though not absolutely restricted to it, is its most 

characteristic fossil and may serve to name the zone. The genus Heliophrentis Grabau is 

further clmracteristie and distinctive, whlle Schuchertella interstriata links it with the Bullhead 

(Akron) dolomite of western New York, this and the Cobleskill being its eastern extension. 

Stropheodontas of Devonic aspectfurther characterize the faunre. In common with the Anderdon, it has an abundance of Oonocardium monroense Grabau, which is the zone fossil of the two 

formations combined. The spiriferoid genus Prosserella Grabau has species in the three upper 

members of the Upper Monroe to which it is restriCted (Prosserella horizon). 

(d). Lucas dolomite.-This name was proposed by Prosser in 1903 for the upper dolomites 

so well exposed in Lucas County, Ohio. Here they mostly rest directly on the Sylvania, the 

other beds being cut •out by overlap. The fauna is rich and peculiar, European types of gastropods predominating. The genus Acanthonema Grabau, though represented in the Amherstburg, is most characteristic, and the faunal zone may be designated the Acanthonema zone. 

Its thickness varies up to 200 feet or over. Oylindrohelium profundum is restricted .to it and 

may· be regarded as another goo,d zone fossil. . 

The propos~d classificat~on of these authors in tabular form is as follows: 

Upper Monroe or Detroit River series (L., P., S., and G.); zone of.Prosserclla: · . 

(d) Lucas dolomite (Prosser). (Zone of Cylindrohelium profundum and Acantlwneina.) 

(c) Amherstburg dolomite (Sherzer an9, Grabau). (Zone of Panenka canadensis.) 

(b) Anderdon limestone (Nattress). (Zone of Idiostroma nattressi.) 

(a) Flat Rock dolomite (Lane, Prosser, Sherzer, aud Grabau). Zone of Syringopora cooperi. 

Disconformity. · 

Middle Monroe: Sylvania sandstone. 

Disconformity. 

Lower Monroe or Bass-Islands s!'Jries (L., P., S., and G.); zone of Leperditia: 

(d) Raisin River dolomite (Lane, Prosser, Sherzer, ~nd_ Grabau). (Zone of Whitjieldella prosseri.) 

'· (c) Put-in Bay dolomite (Lane, Prosser, Sherzer, and Grabau). (Zone of Goniophora dubia). 

(b) Tymochtee beds (N.H. Winchell). 

(a) Greenfield dolomite (Grabau). (Zone of Schuchert~lla hydraulica.) 1 

-

The characteristic faunas of the above-p.amed divisions are listed by Sherzer 

and Grabau in a preliminary article 738 and appear with full descriptions in a report 

published by the Michigan Survey.385 The authors deduce from the faunas and 

stratigraphic relations three interruptions in the process of sedimentation, or "disconformities," and comment on the relations as follows: 738a 

A·survey of these faunas brings out tl~e remarkable fact that there is nothing in common 

(a few doubtfully identifitld gastropods excepted) between the Lower and Upper Monroe: So 

distinct are the faunas that they may be considered as derived from widely separated proxinces. 

The Lower Monroe is apparently an Atlantic fauna or series of faunas, and we are led to believe 1 

that an embayment from the ,Atlantic extended as far as Wisconsin _in post-Salina time and 

that the successiv~ members of the Lower Monroe were deposited in this. The marine "Salina,, 

d~scribed by Schuchert from Maryland most probably belongs here, the path of invasion being 

approximately across that region. There appears to be nothlng in New York which corresponds 
SILURIAN. 249 

to this series, that State being apparently north of the embayment. The embayment covered 

Ohio, Michigan, and probably a part of Indiana and extended into Wisconsin: 

Following the deposition of the Lower Monroe came a retreat of the sea and eolian deposits 

of quartz sands accumulated upon the limestone foundation. These are now seen in the · 

Sylvania sandstone, the source of the material of which probably was the St. Peter sandstone. 

The Upper Monroe invasion was from the northwest, and it brought with it a wholly new fauna, 

in which the prevailing element was of Devonic aspect. A large proportion of the species of 

the Anderdon and Amherstburg beds is most nearly :t:elated to the Schoharie fauna, the similarity 

being ofteri so great that species have been .described as Schoharie or Onon1aga forll1S. 

For a list of species more nearly related to Middle Devonian forms than to 

known.Silurian see the publication cited. On these species Sherzer and Grabau 738b 

comment as follows: 

This list of species shows that the Anderdon-Amherstburg fauna is :m:o~t nearly related to 

the Schoharie fauna of eas~ern New York, and that it probably represented the stock from 

which that fauna was derived. Coral-reef conditions existed in Michigan and Ontario at that 

period, the eastern extension of these conditions being first manifested in the water-lime.deposits, 

and later in the Akron, and finally in the Cobleskill. This latter marks the period of reestablishment of connection with th~ Atlantic, and we find that tlus formation is especially characterized 

by an Atlantic fauna in its more eastern development (Halysites, etc.)~ The faunas mingled 

in the neighborhood of the Schoharie region.a 

~~~~~~~~~:With~the~pening~_i;_he Atlantic connections the late Siluric gastropod and cephalopod 

fauna entered tllis region and becal11e characteristic of~tn.e succeeding~Manlius-lJUcas deposits,-

while the typical Anderdon fauna soon disappeared. A comparison of the Anderdon and the 

· Lucas fauna shows scarcely a common ~pecies. · In the Amherstburg; however, there is more 

. or less of the comminglmg of the two faunas. That the junction with the Atlantic was effected 

while the Amherst burg beds were forming is shown by Siluric gastropod and cephalopod elements 

in its fauna, and their absence from the Anderdon ,fauna. The correlation of the Amherst burg 

and Cobleskill thus seems evidenced. 

Considering the Anderdon fauna as a whole, we see a blending of types of the Siluric with 

those of Devonic affinities. Recognizing that this fauna is interpolated between two Siluric 

faunre, we are forced to admit that here is an example coming perilously near satisfying the 

demands of Barrande's .theory of colonies~ Somewhere the Siluric fauna must have developed 

into the. Devonic, while in other regions the Siluric fauna still lingered. That this Devonic 

aspect is that of the :i:nid-Diwoilic fauna of America rather than the lower shows that this 

evolution was progressing along different lines from that of the Helderbergian fauna. This 

iatter fauna is alien to North America, as is well known, having come to us from Europe. 

Somewhere in northwestern America an indigenous Lower Devonie fauna existed, which in 

turn gave rise to the Middle Devonic faunas of America. This indigenous American Lower 

Devonic must have been much like the Middle Devonic fauna, seeing that the indigenous Upper 

Siluric is already so far advanced as to have a decided mid-Devonic aspect. 

It might of course be argued that the Upper Monroe is the indigenous .L9wer Devonic of 

America and that it existed contemporaneously with the Helderbergian fauna. On such an 

interpretation the Sylvania marks the Siluro-Devonic hiatus, a"ud the upper hiatus representing 

the folding and erosion of the entire of Monroe and earlier rocks falls into the Oriskany.· That 

period, as we know it, was scarcely long enough for the accomplishment of such extensive 

erosion as is implied in the pre-Onondaga hiatus, though it is kiwwn that a considerable amount 

was accomplished during that time. The strongest argument against such an interpretation is, 

however, the Siluric character of the fauna of the Lucas dolomite and the evident correspondence 

of the Amherstburg and Cobleskill horizons. · 

a Graba4., A. W., Bull. New York State Mus. [No. 92, 1906], p. 131. 
250 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Lane 517 states his views on the significance of the stratigraphy in the article 

already cited, together with details of well records. 

L 17. LAKE TEMISCAMING, ONTARIO. 

The Silurian outlier of Lake Temiscaming, first described by Logan, 543• 

54m has 

more recently been mapped and discussed in detail by Barlow.15•

55a At those points 

where the formation was deposited on the pre-Cambrian rocks there is a basal conglomerate, consisting in part of subangular talus blocks, in part of smaller pebbles 

of the adjacent older rocks in a calcareous cement. The deeper-water deposits are 

fine-grained yellowish limestone, with some shale and a considerable proportion of 

chert in some beds. The large collections of fossils from this section represent the 

Niagaran (including the Clinton). 

L 18-19. SOUTHERN QUEBEC. 

Isolated areas of Silurian strata occur in synclines southeast of the St. Lawrence. 

They are composed chiefly of limestone, characterized by Silurian corals. They lie 

unconformably upon the Ordovician strata. Detailed local descriptions are given 

by Ells. 310• 

311a, 313b A noteworthy correction of earlier descriptions is the determination of a so-called conglomerate of St. Helen's Island, Montreal, as a volcanic 

breccia "of later date than the Helderberg limestone." 

In the Memphremagog area313cthe formation is characterized by a considerable thickness of limestone, some of which is graphitic, while other portions are highly dolomitic and are associated with dolomitic grayish slates. 

* * * The structure in this area is that of a folded. basin resting, on either side of the lake, 

upon fossiliferous lower Trenton rocks [Magog formation]. The rocks are altered from calcareous slates and limestones to talcose and mica schists or to graphitic crystalline marble, and 

are cut by numerous dikes, which are often of large size. 

L 19. NEW HAMPSHIRE (LITTLETON). 

In the township of Littleton, in northern New Hampshire, is an occurrence of 

fossiliferous strata, in part at least of Niagaran age, with possibly slates of Helderberg age as well. 

Under the heading "Silurian and Devonian strata," Hitchcock 454 includes 

"the Coos mica schist and quartzite, the Niagara limestones, and slates, sandstones, and argillites." There is no good evidence as to the age of the mica schist. 

The unaltered strata occur in Blueberry Mountain, which is believed to have 

a synclinal structure. If so, the sequence of formations in ascending order is as 

follows: Limestone, sandstone, coarse conglomerate, bluish and black slates. 

Hitchcock 454a reports the following fossils from the limestone: "Favosites basaltica, 

F. niagarensis, Zaphrentis, Astrocerium venustum, Halysites catenulatus, Pentamerus 

nysius, a lingula, crinoidal fragments, a gastropod, Dalmania limulurus, and fragments of a Lichas," determined by Billings and Whitfield. 

L 20. NOV A SCOTIA. 

Under the heading "Siluro-Devonian rocks of Digby and Annapolis" (the 

southwestern counties of Nova Scotia) Bailey 43 gives a detailed account of the slates 

and intercalated impure limestones which lie along the north side of the intrusive 
SILURIAN. 251 

granite and which contain fossils of late Silurian and early Devonian age, as determined by Sir William Dawson, by Logan, and on fuller collections by Ami. 

Farther northeast in Pictou and Colchester counties, Fletcher 335a distinguishes 

strata which he assigns to Medina, Clinton, and Niagara horizons. Fossils determined by Ami include Cyrtograptus grayice, "characteristic of the lower half of the 

Silurian system.'' 

The Silurian rocks of Arisaig, in Antigonish County, on the coast of Northumberland Strait, were first described by Honeyman.461 Fletcher 334a gives a somewhat 

detailed section, from which the following is condensed: 

Feet. 

Lower Helderberg, argillaceous sandy flags with thin fossiliferous limestone .................... 1,038 

Niagara, argillaceous, calcareous rocks with numerous layers of richly fossiliferous limestone 

(400 feet) followed by dark shales, also fossiliferous ....................................... 1,293 

Upper Clinton, green arenaceous shales and fine sandstone...................................... 148 

(Break in section.) 

Lower Clinton, dark-gray, crumbly, papery argillites .......................... ____________ .. 345 

Medina, greenish to gray, more or less massive sandstone ___ . _. _. ______________________ . _ _ _ _ 182 

These strata lie in a "syncline, 6 miles long and 1~ wide, bounded on the south 

by a fault indicated by an escarpment of Cambro-Silurian rocks; on the north by 

pre-Cambrian; and on the west by Devonian and Carboniferous, which overlie 

them." The relation of conformity or unconformity tp the "Cambro-Silurian" 

(Ordovician) is not clearly stated. With reference to the Silurian-Devonian contact Ami 18a suggests a possible unconformity, but says: "On the whole, the general 

trend and behavior of the strata referred to the Silurian and Devonian systems are 

fairly uniform and generally identical." On the other hand, the lower Carboniferous. 

conglomerates and limestone extend with marked unconformity across the Silurian 

and Devonian. 

The Arisaig section and other sections of the Silurian in Nova Scotia have 

been classified by Ami 17 as follows: 

The Silurian system as understood in Canada, and restricted to the upper division of Sir 

Roderick Murchison's Silurian, is extensively developed both in Nova Scotia and New Brunswick. At Arisaig, in Antigonish County, Nova Scotia, several thousand feet of more or less 

disturbed and inclined strata, including an almost regular succession of different members of 

this system, made up of sandstones, slates, iron ores, and black graptolitic slates and limestones, 

with mudstones, are well exposed and present a compact fauna, which in facies closely resembles 

rocks in Herefordshire, in Cumberland, Westmoreland, in the Kendal and Ludlow regions of 

England. The "Knoydart" formation, consisting of red shales and sandstones and calcareous 

bands holding pteraspidian and ostracoderm fishes and crustaceans referable to the Cornstone 

or lower Old Red sandstone of Great Britain, almost immediately overlies the Silurian strata, 

though no actual contact has been observed. The Silurian series at Arisaig consists of at least 

four distinct geological formations. Beginning above we have first the "Stonehouse" formation, consisting for the most part of dark-red, fine-grained shales and mudstones, holding a 

conspicuous lamellibranchiate fauna, of which Grammysia acadica Billings is a well-known 

species, together with a number of interstratified more or less thin calcareous bands holding 

brachiopods, gastropods, trilobites, and ostracods in abundance. Below this we find the 

"Moydart" formation, which consists of more or less heavy bedded light greenish-gray and 

rusty-weathering calcareous strata (in which the "Red stratum" of authors occurs) and holds 

brachiopods, gastropods, cephalopods, and crinoids. Beneath this again we have the "McAdam" 

formation, consisting for the most part of impure black carbonaceous shales, which are splintery 

• 
252 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

at times, holding a lamellibranchiate fauna and graptolites. At the base occurs the "Arisaig" 

formation, which comprises buff-weathering fine-grained compact sandstones and shales, containing corals (chiefly Streptelasma), brachiopods, gastropods, and' trilobites. The thorough 

investigation of this series of strata, which, indeed, may require further subdivisi<?n, is expected 

to furnish data bearing on the settlement of the mooted question as to where the Silurian 

stops. * * * 

In the county of Annapolis, Nova Scotia, and in the vicinity of Nictaux Silurian strata 

occur, including the Nictaux iron ore beds and the Torbrook sandstone formation, whilst near 

Kentville the Kentville formation is seen, as well as on Angus Brook, in the Gaspereau Valley, 

also at New Canaan, with Dictyonema websteTi Dawson, and at Wolfville, in King's County, 

where coralline limestones, red and green graptolitic slates, and other strata, at times highly 

cleaved, squeezed, and metamorphosed, form conspicuous ridges and constitute the oldest 

sedimentaries in the vicinity of the Bay of Fundy and the Blomidon region in the "land of 

Evangeline.'' 

In Cumberland County, along the northern slope of the Cobequids, isolated areas of Silurian 

strata have been mapped out and described by Mr. Scott Barlow and Mr. H. Fletcher, the 

Wentworth and Farmington areas being among the most important and best known. These 

appear to belong to the lower half of the Silurian. 

L-M 19-20. MAINE, NEW BRUNSWICK, AND GASPE. 

Northeastern Maine, northwestern New Brunswick, and the Gaspe Peninsula 

are occupied by a broad synclinorium of Silurian strata, which appear to lie unconformably upon folded and eroded Cambrian rocks and are overlain conformably 

by Devonian rocks. 

A section which is typical for Maine and New Brunswick is that observed on 

Temiscouata Lake, just across the boundary in Quebec. This section was described 

in great detail by Logan 544t and has been reexamined by Bailey,47b who has also 

traced out the distribution of the sediments in New Brunswick and Quebec as well 

as in Maine. As determined by him on fossils, the sequence of strata ranges from 

lower Niagara (Clinton) to "Lower Helderberg" (Helderberg), with possibly an 

unconformity also at the base of the latter. The section is partly concealed, the 

structure involves older beds apparently overlying younger, in consequence of overthrusting, und his Lower Helderberg rocks appear to overlap his earlier Niagara 

and lie upon the Cambrian. The strata dip southeastward, but the sequence from 

northwest to southeast is shown to be Cambrian, unconformity (?), Lower Helderberg, thrust fault (?), Niagara, unconformity (?), Lower Helderberg. For details 

we quote Bailey's report: 

The rocks of Lake Temiscouata have been described in considerable detail and are given 

with sections illustrating the relations and probable thickness of the principal beds in the 

"Geology of Canada," 1863, pages 419-425. * * * The following section is a condensation 

of that in the "Geology of Canada," with such additional information as has been recently 

obtained. The section begins on the north side of Mount Wissick or Mount Lennox, where 

the rocks of the Silurian system may be seen to rest unconformably upon those of the "Quebec 

group." 

Greenish-gray and black slates, alternating in thin bands, 2 to 3 inches wide, with gray or buff 

weathering dolomitic limestones. These beds occur on the northeast side of a small cove 

above Mount Wissick and are a part of a similar series of rocks, supposed to be of the same age 

as those of Point Levis which occupy all the upper part of the lake. They have been subjected to much crumpling and exhibit considerable irregularity of inclination, their dip, 

where nearest to the Silurian, being N. 40° W. <70°-80°. They have as yet yielded no 

fossils, and their thickness is unknown. 

Measures concealed for about half a mile. 

• 
SILURIAN. 

Feet 

Gray quartzose sandstone, containing white quartz pebbles, mingled with fragments of limestone 

in a greenish sandy matrix. These grits or conglomerates apparently occupy a space across the 

measures of about 1,000 feet, and with a dip of S. 65° E. <40° would give a thicknes3 of. ____ 642 

\Vhite sandstone or quartzite in massive beds. These rocks are gray within but weather almost 

snow-white, with vitreous surfaces, often drusy with small quartz crystals. Some portions are 

pinkish or reddish and others spotted with small red dots. Their thickness, as given in the 

"Geology of Canada," is only 40 feet, but they were found to have a surface breadth of 250 

paces, which, with an average dip of 50°, would give a thickness of. __________________ . ____ ._ 420 

Coarse shaly and rubbly conglomerate, holding limestone pebbles (with some quartz). They 

dipS. 60° E. <70° and have a breadth of 60 paces, corresponding to a thickness of._ ...... _._ 114 

Dark-gray sandstones. DipS. 70° E. <20°. Thickness about. _________________ . ____ .. _.____ 10 

Gray calcareous shales, filled with bands, nodules, and lenticular masses of limestone, abounding 

in fossils. [For partial list, see op. cit.] These beds are regarded by Mr. Ami, by whom the 

fossils have been examined and in part collected, as corresponding to the Chat River limestones, 

equivalent to the upper part of the Chaleur group,· and about equivalent to the lower part of 

the Lower Helderberg formation. Dip S. 65° E. <60°. Thickness about.___________________ 10 

Red and green shale, in alternating bands, with green argillaceous sandstones. The dip of these 

beds where they overlie those last mentioned is S. 65° E. <15°, their strong slaty cleavage 

having an underlay of N. 65° W. <S0°, but in following them along the precipitous face of the 

mountain they are found to fold over and exhibit a dip N. 40° W. <40°. They are also broken 

by a fault. Their estimated thickness is .......... ____ .... ________ . ____________ . __ .. _ .. _ .. _ 125 

Gray nodular limestones, conspicuously divided by vertical joints, which often present curved 

surfaces and produce an appearance resembling that of fluted columns. These beds rest 

directly upon the red and green shales and are probably arched with them, but toward the 

southern end of the bluff resume their normal dipS. 65° E. at an angle of 50°. The columnar 

limestones, which contain but few fossils, have a thickness of about 10 feet and are followed 

by about the same thickness of finely banded massive limestones, having at the top a zone, 

from 1 foot to 18 inches thick, filied with branching corals, chiefly Favosites; it also holds shells 

of Atrypa reticularis and Pentamerus. This is capped by more columnar limestone, the whole 

having an aggregate thickness of about .. __ .... __ .. _________ .. _. __ ... _______ .............. _. 50 

Gray hard sandstone, with beds of impure limestone, the sandstone containing remains of 

Meristelhe ....... _. _ ..... _ ... _________________________ . _ .. ___ ..... _. _____ ... _ ......... _ _ _ 30 

Gray nodular limestone, without observed fossils ........... _ ... ____ .... ____ .................. 30 

Gray banded limestone, filled with corals and other fossils, including Favosites gothlandicus 

Lamarck, Strophodonta varistriata Conrad, in great abundance and forming the typical representative of the zone [together with a number of other species; for list, see op. cit.]. (Mr. Ami 

considers these fossils also to indicate the horizon of the lower portion of the Lower Helderberg 

series.) Thickness about ..... _ ..... _______ ...... ____ .. _ ...... __ ..... _ ................. __ 30 

Gray arenaceous limestones and sandstones forming the upper portion of Mount Wissick but 

sloping to the level of the lake, with a dipS. 70° E. <13°. These higher beds contain comparatively few fossils, among which are the following: A stromatoporoid form; crinoidal fragments, in abundance; Chonetes sp., a rathet arcuate form, smaller than C. nova-scotica Hall 

and larger than C. tenuistriata Hall, resembling somewhat C. melonica Billings; Meristella sp. 

Their supposed thickness is about .......... _ ....... _ .... _ ... ______ .. ______ ................ 500 

253 

Tho beds may, therefore, be correlated with the Lower Helderberg or with the Ludlow 

formation of Britain. 

A summary of the above section is given in a later report by Bailey48 from which 

the following is taken: 

As represented upon Lake Temiscouata the portion of the Silprian system which immediately adjoins and overlaps the Cambrian strata to be presently described does not represent 

the lowest member of that system, being composed of white sandstones and overlying calcareous rocks, of which the fossils indicate an age ranging from the lower to the upper part of the 

Lower Helderberg horizon, while at a short distance south are heavy conglomerates followed by 

hard sandstones and shales containing fossils chiefly of the Niagara formation. * * * 

Immediately to the south of the above undoubted Silurian strata is found the great series 

of slates first described in the "Geology of Canada" in connection with the Gaspe series and 

which has since been found to spread so widely over the northern portions of New Brunswick, 

as well as adjacent areas in Quebec and Maine. These slates, as seen along the lower half of 

Temiscouata Lake and on the Madawaska River, are of gray, bluish-gray, and dark-gray, rarely 
254 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

black colors, often weathering to a dull olive-green, very fine grained but including harder bands, 

and generally more or less calcareous. They are throughout characterized by numerous and 

often intricate contortions and these, with a strongly developed slaty cleavage, make any 

attempt to determine their thickness or relations well-nigh hopeless. Neither on the lake nor 

on the Madawaska have they been found to contain any fossils, these having probably been 

obliterated by molecular movements; but the occurrence of fossils at many different points in 

the resembling strata which spread so widely to the east and south, and all of which indicate a 

Silurian horizon, seems to justify the position first assigned them as also Silurian, and as the 

equivalent of the upper part of the Gaspe series. 

Southwestward from Temiscouata Lake the gray to olive-green slates called 

by Bailey Lower Helderberg occupy the basin of St. John River in northwestern 

Maine. Their relations to the overlying Devonian in Aroostook have been described 

by Bailey 47d and more recently by Williams and Gregory. 937 (See Chapter VI, 

L 19, pp. 325, 328.) 

Northeastward from Temiscouata Lake to the Metapedia section, the outline 

of the Silurian beds in relation to the Cambrian on the north has been retraced by 

Bailey and Mclnness.47a Beyond the Metapedia Ells 308 and Low 548 determined 

their distribution between the Cambrian and the Devonian as far east as the Cascapedia, whereas from the headwaters of the Magdalen to Cape Rosier the lines are 

placed as worked out by Logan 544" and Ells. 307 The areal geology of the peninsula 

south to the Bay of Chaleur is according to the same authorities. 

The strata thus mapped as Silurian are those assigned to that period according 

to the past and current usage of the Canadian Survey, and they include the strata 

identified by Bailey as Lower Helderberg, which is now classed as Devonian, according to Schuchert 711 and Clarke. 157 The literature contains a number of doubtful references to Silurian or Devonian, the uncertainty being due to the transitional character 

of the fauna, which has commonly been assigned to the uppermost Silurian but contains Devonian forerunners. Ells aosa cites observations of unconformity between 

Silurian and Devonian on the tributaries of the Cascapedia, and Bailey 47c infers an 

unconformity between the rocks identified by him as Niagara and Lower Helderberg 

on Lake Temiscouata, which might be at the same horizon. The overlap of the 

latter formation beyond the former seems to be well established. The base of the 

Niagara, as thus identified by Bailey, is a white sandstone associated with bodies of 

calcareous conglomerate, consisting of limestone pebbles and angular fragments in a 

sandy matrix. No fossils have yet been found in the limestone pebbles, but the 

position of the strata at the base of the rocks identified as Niagara and their relation 

to the near-by Cambrian rocks are such as to suggest their derivation from the Cambrian. A marked unconformity is thus indicated. Logan 544u describes two unconformable contacts seen on the coast near the line between Gaspe and Bonaventure 

counties, as follows: 

The vertical strata of this group [the "Quebec group"] extend along the coast toward Anse 

ala Vieille, where they are overlain by the inclined strata of the Gaspe limestones, which in their 

turn support the Bonaventure conglomerates, the three series being unconformable with each 

other. 

The proofs of this double discordance lie within a space of half a mile, a little less than 2 

miles westward of the line between the counties of Gaspe and Bonaventure; and as there is no 

concealment of strata, the whole is readily apparent to the eye. The. smoothly worn edges of 
SffiURIAN. 255 

the vertical strata of the Quebec group here support an even layer of 4 feet of hard grayishwhite strong siliceous conglomerate, which divides into layers of a foot or two, and would make 

good millstones. It dips S. 4 ° W. < 38 ° and is conformably overlain by a great series of fossiliferous limestones and shales. At a point about 230 yards along the beach from the millstone 

layer these calcareous strata dipS. 3° E. <45°, in a cliff 100 to 120 feet high. Upon the basset 

edges of these the beds of the upper conglomerate are seen to repose, with a dipS. 42° E. <20°. 

These stretch along for 200 yards, presenting a perpendicular precipice in front; while the 

underlying calcareous series forms a talus and occupies sometimes more and sometimes less than 

one-half the height of the cliff. 

This unconformity is well established farther south. From the Bay of Chaleur 

the eastern margin of the Silurian extends southwestward across New Brunswick 

into Maine. The areal distribution is not well known, the structure being complicated, the Cambrian, Ordovician(~), and Silurian rocks being similar, and intrusive 

rocks abundant; but in the course of a resurvey of the line between the "CambroSilurian" (Ordovician) and the Silurian, Bailey 44 found "incontestable evidence of 

discordance along its whole length." He cites occurrences of conglomerates containing pre-Silurian rocks at the base of the Silurian strata. 

Bailey 476 summed up the known facts of the stratigraphy of the Silurian of 

northern and southern New Brunswick as follows: 

Sequence of Silurian strata in southern New Brunswick. 

Mascareen Peninsula. 

Feet. 

I. Gray feldspathic slates, about. _ . _. _ ..... _. _. 400 

II. Gray and black banded siliceous slates, with 

nodular layers ...... _ .. -... __ ..... __ ....... 620 

III. Gray flaggy sandstones, with some conglomerate. Shells of Lingula, Modiolopsis, and 

Loxonema?, with comminuted vegetable 

matter._._............................... 350 

IV. Red and green slates and sandstones, with 

diorites and felsites ..... _.................. 300 

V. Dark-gray and reddish porphyritic felsites... 300? 

Southern Queen's County. 

Feet. 

I. Gray and dark-gray slates._----------------- 400 

II. Dark-gray and black siliceous clay slates, distinctly banded ______ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 600 

III. Dark-gray and greenish-gray, sometimes purplish sandstones, becoming slaty above. __ . 600 

IV. Ash-gray and greenish-gray schistose beds, 

dioritic and amygdaloidaL _____________ .. 300 

V. Gray and dark-gray, sometimes reddish porphyritic felsites, with chloritic schist and 

breccia conglomerat~ _ . _ ... __ ... _. ____ . . . . SOO+ 

In the same work Bailey details the relations of the strata of southern New 

Brunswick, northern New Brunswick, Quebec, and Maine, and sums up as follows: 

Supposed sequence of Silurian strata in northern New Brunswick, Quebec, and Maine. 

[Ascending section.] 

Divisions I and II.-Gray argillaceous and siliceous slates, including (locally) heavy beds of conglomerate. Fossils 

somewhat numerous in upper part, including shells and graptolites, indicating a low Silurian horizon. 

Conglomerates and succeMing slates of Black and Burnt points, on Lake Temiscouata; feldspathic and siliceous 

slates of Fish River and Alleguash River, Aroostook County, Me.(?). Conglomerates and graptolitic slates of 

Beccaguimic River, Carleton County, New Brunswick. Supposed to be equivalent to the Medina and Clinton 

groups of New York, divisions 2 and 3 of Anticosti group, or groups Band B' of Arisaig. 

Division III, A.-Gray flaggy and massive sandstones, with some conglomerate, becoming frequently greenish or purplish and more or less amygdaloidal. Fossils rather numerous, including corals and shells, as well as worm tracks 

and comminuted remains of plants. 

Sandstone11 and conglomerates of Pointe aux Trembles, Tuladi and Squatook rivers, Quebec; similar beds of 

Siegas River, New Brunswick; sandstones and conglomerates of Aroostook County, Me.; similar beds of Beccaguimic River and other parts of Carleton County, New Brunswick. 

Niagara formation, or \Venlock group. 

Division III, B.-Lower sandstones, shales, and limestones of the Gaspe Peninsula. Similar sandstones and limestones 

of the head-waters of the Chatte and Matane rivers, Metapedia Lake, Metis and Rimouski rivers, and lower part 

of Mount Wissick. Fossils numerous, marin~ 

Supposed to be equivalent to the Guelph formation of Ontario~ 
256 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA, 

Divisions IV and V.-Red and green shales of Cape Gaspe; red and green slates and sandstones of Mount Wissiok; 

similar slates on Fish River (Eagle Lake) and Aroostook River, Maine; red and green slates of Grand River and 

Carleton County, New Brunswick; often including argillaceous iron ores. · (?)Felsites and associated trappean rocks 

of Campbellton and Bay Chaleur, Moose Mountain, New Brunswick, Haystack and Spider Lake, Maine. 

Division VI.-Gray, often nodular or columnar limestones, abounding in fossils. 

Upper limestones of Cape Gaspe; middle and upper rocks of Mount Wissick, regarded as equivalents of the 

lower portion of the Lower Helderberg. 

Fossiliferous limestones of Square Lake and Ashland, Me.; Lower Helderberg. 

Fossiliferous limestones of Carleton County, New Brunswick. 

Fossiliferous slates and sandstones of Metapedia River, Restigouche, Victoria, Madawaska and Carleton counties, 

New Brunswick. Similar slates, etc., of Aroostook County, Me. Lower Helderberg (?). 

Silurian strata of southern New Brunswick (Charlotte County) and adjacent 

parts of Maine have in later years been found to be more extensive than had been 

supposed, the Silurian age of certain metamorphic rocks and of slates previously 

assigned to older horizons having been determined. 70 The geologic relations are similar to those about Penobscot Bay, Maine. (See L 19, pp. 134-135.) 

L-M 21. NEWFOUNDLAND. 

Under the heading "Upper Silurian series" Murray, in 1864, described conglomerates, slates, and mica schists, together with intrusives of granitoid character, 

all of which are exposed in sections on Jackson's and Sop's arms of White Bay, 

Newfoundland. Murray 608 states: 

Jackson's Arm runs into the land nearly at right angles to the strike, and here these upper 

rocks have a transverse breadth of about 2 miles. The following section of them, in ascending 

order from the mica slates on which they are seen to rest, is taken from the north side of the arm, 

on which the measures appear to be broken by three considerable faults, causing what are 

supposed to be modified repetitions of some of the masses. 

1. Coarse conglomerates, with a light-gray arenaceo-micaceous slaty matrix which is slightly 

calcareous. The masses inclosed consist of pebbles and bowlders of gneiss, large rounded 

fmgments of whitish or light-gray mica slate, some of a darker-gray greenstone, reddishgray quartzites, and occasional smaller masses of limestone; among these there is a good deal 

of finer material of the same character, slightly calcareous, and mica schist runs in irregular 

flakes and patches in the general direction of the stratification, but its cleavage often parFeet. 

tially conforms to the rounded surface of the bowlders and pebbles. The beds are very 

massive, and they appear to be divided by gray micaceous schist...................... 400 

2. Sea-green slates, occasionally interstratified with dark-gray or blackish fine silky-surfaced 

slates, some of which are harder than others. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300 

3. Gray, coarse, rough arenaceo-micaceous schist, frequently passing into a fine conglomerate, 

with pebbles similar in mineral character to those of the coarse conglomerates beneath, but 

none of them exceeding the size of a hen's egg; the pebbles are sometimes arranged in reguhtr layers, parallel to the stratification; bands of dark-gray clay slate are occasionally interstratified in the mass.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400 

4. Gray micaceous and arenaceous slates................................................... 250 

5. Green and black slates at the base, succeeded by gray arenaceous slate, which is interstratified with thin bands of sandstone.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 650 

6. Green, bluish, and blackish slates, interstratified with gray flaggy sandstones; the slates 

inclose nodules of pinkish calc spar, and veins of the same cut the strata............... 250 

7. Grayish-blue limestone in a single bed ................. _................................ 7 

8. Gray calcareo-arenaceous slates, interstratified with grayish sandstones, with a heavy mass 

of gray, white-weathering sandstone at the top ...................................... _. 543 

2,800 

The above section can only be considered as giving an approximation to the truth. The 

three faults which dislocate the rocks and are all considered to be upthrows on the east side 

render it difficult to follow the sequence with exacti'eude; and some of the masses, whi.ch are 
SILURIAK. 257 

supposed to be in a general way equivalent on opposite sides of the faults, appear in different 

parts to be modified in volume and somewhat in lithological character by different degrees of 

metamorphic action. 

The intrusive relations of the igneous rocks and the metamorphosed condition 

of the sediments, particularly on Sop's Arm, are described by Murray, who states 

further: 

Between the conglomerates of Sop Island and those of the eastern end of Sop's Arm the 

rocks of the western part of Sop Island, of Goat Island, and of the main coast appear to be 

slates of various shades of green, often marked by pink calc spar in nodules, patches, and short 

veins; of occasional interstratified sandstones, sometimes fit for flagging, with calcareoarenaceous bands; and occasional impure limestones, weathering brownish. East of Bartlet's 

Cove, which is an indentation on the south side of the southwestern extremity of Sop Island, 

there was seen a thickness of 50 feet of black slates. These rocks are, in several places, characterized by fossils, which are somewhat obscure; but though few of them could be specifically 

determined, they have yet, according to Mr. Billings, a general aspect allied to that of Upper 

Silurian types. It would, however, for the present, be impossible to say to what horizon in 

the series the different divisions of the rocks of Jackson's Arm and of Sop's Arm may belong, 

and it may be proper to remark that while no doubt is entertained of the general equivalency of 

the rocks of the two localities, all the places in which organic remains were observed occur in 

the neighborhood of Sop's Arm. 

One of these localities is Bartlet's Cove. Here the fossils occur in calcareo-arenaceous 

flagstones, and the genera observed, in addition to numerous fucoids and crinoidal stems, were a 

Murchisonia, an Orthoceras, and a Graptolithus. At a point on the main coast halfway between 

Spear Point and the promontory occupied by the porphyry which strikes from Sop Island 

organic remains were met with in strata somewhat similar to those of Bartlet's Cove; they consisted of fucoids, crinoidal stems, and an Orthoceras. On the western side of Goat Island, 

still in the same description of strata, in addition to fragments of crinoidal columns, there were 

met a Syringopora and Favosites gothlandica. 

In Murray's report for 1871/osa based on Howley's exploration of Exploits and 

Gander bays and vicinity, the Silurian is described as the "Upper, unconformable 

formation," which is said to occupy a rudely elliptical trough. 

The evidences, so far, tend to show that while the formations butt up against the Quebec 

group on the northern and southern sides of the trough, they overlap the junction of the latter 

at the eastern and western extremes. 

The central part of this elongated trough has been greatly disturbed for the whole length of 

its course, from the head of the Red Indian Pond to the Dildo Run, where vast dikes were seen 

to cut through the strata at very many parts, while great areas are spread over by overflows of 

trap, or breccious intercalations. * * * 

The base of the Upper and unconformable formation consists of conglomerate and sandstones, with slaty divisions, which, at Goldson's Sound, seem to come against the older and 

altered rocks in a slightly oblique direction, as if brought into their present position by a fault, 

the lower beds dipping about S. 55° E. <24°. The lower conglomerates are of a reddish 

general color, the matrix being constituted of fine reddish sand, sometimes slightly calcareous, 

which incloses well-rounded pebbles of quartz, reel jasper, green jaspery slate, and fragments 

of magnesian rocks. The pebbles are not usually large, the largest being about the size of a 

hen's egg. The strata in ascending succession are still of conglomerate character, but the color 

gradually passes into gray, and there are numerous pebbles of gneiss and syenite mingled with 

the other qualities, and they are frequently characterized by the presence of hard blue or 

blackish cherty concretions, which weather a bright yellow, are sometimes concentric in structure, 

and of an elliptical shape. The islands of Goldson's Sound expose an alternation of conglomerates and red sandstones,. with dark-gray slates, which are themselves occasionally finely con480110--12----17 
258 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

glomerate and were found to contain numerous stems of encrinites. The dip of the slates is 

south by west 80°. In front of the encrinal beds, on the long projecting point between the 

arms of the sound and on the islets at the head of the northern arm, some strong beds of coarse 

conglomerate are exhibited, which are overlain by black or dark-gray slates, with thin beds of 

gray sandstone, of from 1 to 6 inches thick. The conglomerate is often very calcareous and 

frequently contains irregular intercalations of limestone. The dip of these rocks is S. 20° 

E. <60°. Both the conglomerates and associated beds above the encrinal slates were found 

to be very fossiliferous and in their strike up the southern shore of the eastern arm were there 

found to pass beneath another mass of coarse conglomerate, which forms the escarpment to the 

hills which strike in the direction of the point between Pike's and Little Cobb's Arm. The 

total thickness of this part of the formation, from the junction with the older group to the 

last-mentioned conglomerate, was estimated to be about 2,000 feet. 

The fossils recognized in the strata alluded to appear to be types of the Middle or Upper 

Silurian series, or about the horizon of the Llandovery group of the British Survey. Some of 

those previously collected were referred to Mr. Billings, of the Canadian Survey, who identified 

the following genera and species: Favosites gothlandica, Heliolites ~' Zaphrentis bellistriata, an 

encrinite referred to the genus Glyptocrinus, a coral referred to the genus Heliophyllum, Orthis 

ruida, Leptrena sericea or perhaps transversalis, ventral valve of an orthis like 0. davidsoni, 

Strophomena rhomboidalis, Atripa reticularis, Stricklandinia lens, Modiolopsis, Ambionychia, a 

trilobite, genus Encrinurus, and some others not determinable. 

The conglomerates of the escarpment above mentioned are succeeded by a set of slates 

which are occasionally slightly micaceous, with beds of quartzite from 2 inches to a foot thick, 

the strata of which run out upon the coast on the southeast side of Goldson's Sound, usually 

called Burnt Arm, at the head of which arm the slates pass beneath a mass of limestone, with 

black slate and trap breccia. At this part trap intrusions are met with and the strata are 

violently disturbed and altered in some parts in such a degree as to assume somewhat the 

aspect of the inferior formation, but the occasional presence of fossils, amongst which was one 

resembling Zaphrentis and some Encrinites, was supposed to indicate a horizon of later date 

than the Quebec group. 

M 11. ROCKY MOUNTAINS OF BRITISH COLUMBIA. 

In a section examined along the Canadian Pacific Railway McConnell 559 found 

the Castle :VIountain group (Cambrian and Ordovician) to be succeeded in the 

eastern ranges of the Rocky Mountains by the "Intermediate" limestone and in 

the western ranges by the Ordovician " Graptolitic shales" and the "Halysites 

beds." Neither the "Intermediate" limestone nor the "Halysites beds" is stated 

to be of widespread occurrence, owing presumably to erosion and unfavorable 

structural conditions, and they have not been observed in contact. On paleontologic evidence the "Intermediate" limestone is assigned to the Devonian, whereas 

"Halysites catenulatus, Favosites, a coral like Zaphrentis, a.nd some badly preserved 

brachiopods" indicate the Silurian age of the "Halysites beds." The latter consist 

of about 1,300 feet of dolomites and quartzites, the quartzite being at the base 

and the upper part of the formation missing through erosion of the syncline in 

which the strata occur. 

This isolated occurrence and that in the Finlay-Omenica section (N-0 10) 

appear possibly to connect the Silurian dolomite of the Porcupine section, Alaska 

(Q 5-6), with the Silurian of Utah. 4980 
SILURIAN. 259 

M 20. ANTICOSTI ISLAND. 

The Ordovician-Silurian sequence is unusually complete in the island of Anticosti, there being no apparent interruption of sedimentation nor any abrupt change 

of faunas in the passage from one system to the other. Logan 544m gives a detailed 

section, which is presented below in condensed form, lists of fossils being omitted. 

The strata of this [Hudson River] formation occupy nearly the whole of the north side 

of the island [Anticosti] and extend from Fox Point, which is toward the east end, to Junction 

Cliff, on the south side, about 4 miles from the west end. The remaining portion of the island 

is occupied by newer rocks, to which the name of the Anticosti group has been given. Their 

position in the geological series is that occupied by the Oneida conglomerate, the Madison 

sandstone, the Clinton group, and the Niagara group of the New York geologists, but these 

subdivisions, although apparent in the western basin, disappear in the Anticosti strata, which 

are lithologically unlike their equivalents in western Canada. * * * 

The rocks of this group on the island of Anticosti may be considered in four divisions, 

* * * in immediate succession to the Hudson River formation, as follows, in ascending 

ord~r: l. 

1 to 3. Greenish argillo-arenaceous ~hale at base of yellowish-gray compact argillaceous 

limestone interstratified with light reddi~h-gray limestone beds of from 1 to 3 inches 

Ft. in. 

thick, with many fossils, all together............................................... 32 6 

4. Measures partly concealed but supposed to be of the same character as the preceding, both 

lithologically and paleontologically. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 

5 to 7. Ash-gray argillaceous limestone, in beds from 1 to 3 inches thick, alternating with 

beds of calcareo-argillaceous shale of from 5 to 7 inches. Both of these are interstratified 

with light-gray pure limestone beds, 1 or 2 inches thick ............. ,............... 67 

8. Measures concealed.................................................................. 21 

9 to 10. Gray limestone, interstratified with gray and sometimes greenish calcareo-argillaceous shale ............. _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 

11. Yellowish-white coralline limestone................................................... 5 

12 to 14. Gray compact argillo-calcareous beds, slightly bituminous, interstratified with 

argillaceous bands .................. -- ............... · ............................... 139 

2. 

1 to 2. Ash-gray and light reddish-gray limestones, in beds of from 2 to 6 inches thick, interstratified in the upper part with conglomerate beds of some thickness, at intervals of 

from 2 to 10 feet. The pebbles are calcareous, from 1 to 3 inches in diameter, and lie 

306 6 

flat in the beds ............................................................. __ .. _ .. 120 5· 

3 to 5. Reddish-gray limestone, in beds from one-quarter of an inch to 3 inches thick, so:"le 

of which weather to a reddish brown; interstratified with occasional conglomerate 

layers of from 2 to 4 inches thick (toward the top) .............. _ ............. _____ .. 143 6 

6. Measures concealed ............................................. _ .. __ ......... _______ 40 

7. Gray, yellowish-weathering limestone, containing but few fossils .. _ ............ ___ ..... 34 

8. Measures concealed ......................................... _____ ............ ____ . . . . 17 

9. Ash-gray, smoke-gray, and reddish gray, slightly bituminous limestones .......... ______ . 65 

10. Measures concealed .......................................................... _____ . _ _ 27 

447 

3. 

1. Measures concealed ......................................... ___ .............. _ _ _ _ _ _ _ _ 27 

2. Greenish-gray and brown fine arenaceo-argillaceous shales, interstratified with one another, 

in thin beds; no fossils are seen..................................................... 60 

3 to 7. Ash-gray and light-drab limestones interstratified, both slightly bituminous and 

crowded with Stricklanida lirata (near the top) .................. _ ............... _ .... 157 9 

8. Measures concealed, with 1 foot of light-drab argillaceous, slightly bituminous limestone 

in the middle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 

9. Light-drab argillaceous limestone, slightly bituminous, in beds of from hal£ an inch to 3 

inches....... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 6 

10. Measures concealed at the bight of the cove, north of Southwest Point ................ __ . 157 6 

540 9 
260 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

4. 

1 to 3. Yellowish-white granular limestone, in beds of from 3 to 18 inches thick; often separated by thin partings of green argillo-calcareous shale, which is also disseminated in 

Ft. in. 

small patches through the bed..................................................... 57 3 

4. Yellowish-white granular limestone, in beds of from 6 to 18 inches thick; consisting of 

masses of organic remains, of which crinoidal columns constitute the larger part; some 

of them being three-fourths of an inch in diameter_....... .. .. .. . . .. . . . .. .. . . . . . . .. .. 16 

69 3 

This is the highest series of strata met with on the island, and its lithological characters 

are so well marked that it is scarcely possible to mistake it for any of those which precede. 

For the sequence of faunal zones, according to which these lithologically similar 

beds of argillaceous limestone and shale are distinguished by Logan, his original 

account should be consulted. The general faunal relationships and correlation were 

thus summed up by Billings: 82a 

MIDDLE SILURIAN-ANTICOSTI GROUP. 

Division 1.-The rocks of division 1 rest directly and conformably upon those of the Lower 

Silurian, above noticed, with no apparent physical gap between them, although there is a 

paleontological break. It has been already stated that 41 of the species of the lower fauna 

pass this break. They are here joined by 45 additional species, making the whole fauna of this 

division to consist of 86 species, so far as is yet known. Of these, 18 pass upward into division 2, 

13 into division 3, and 11 into division 4. 

Of the 41 species which are received from the Lower Silurian the following are known to 

occur in Canada West and New York and are variously distributed throughout all the formations from the base of the Quebec group to the top of the Hudson River formation. 

Stenopora fibrosa. 

Halysites catenulatus. 

Beatricea undulata. 

Lingula quadrata. 

Strophomena alternata. 

S. planumbona. 

Leptama sericea. 

Orthis porcata. 

O.lynx. 

Orthisina verneulli. 

Ambonychia radiata. 

Subulites elongata. 

Murchisonia gracilis. 

M. ventricosa. 

Bellerophon bilobatus. 

Pterotheca transversa. 

Ortlloceras formosum. 

Ascoceras newberryi. 

Asaphus megistos. 

Calymene blumenbachi. 

Cheirurus pleurexan thcmus. 

Among the 45 species which. here made their first appearance in the rocks of Anticosti we 

find Strophomena rhomboidalis, S. pecten, and Atrypa marginalis, all three very characteristic 

of the Middle and Upper Silurian. The new species include Atrypa umbonata and A. prinstana, 

members of the group of which A. tumida may be regarded as the central form, a type almost 

unknown in the Lower but very prolific of species in the Middle and Upper Silurian. This 

group becomes extinct in the Devonian. The genera Favosites, Heliolites, and Helopora, 

which here first appear in force, are more characteristic of the upper than of the lower half of 

the Silurian series. Most of the other new species belong to the ordinary Silurian genera. 

The fauna of this division is partly Lower and partly Middle Silurian but is more strongly 

tinged with the former than the latter. 

Division 2.-From this division we have only 39 species, of which 18 are received from 

division 1 and 21 here first made their appearance. Out of the whole fauna 23, or more than 

one-half, pass into division 3 and 16 into division 4. As before stated, the only species very 

characteristic of the Lower Silurian are Strophomena alternata and Murchisonia gracilis. The 

most prominent fossil is Pentamerus barrandi, which occurs in vast numbers. Ow-ing to the 

inaccessible character of the coast in bad weather, it was not practicable to make a thorough 

search for fossils in this division. 
SILURIA~\. 261 

Division 3.-In this division there are 53 species, of which 23 are received from division 1, 

and 26 pass upward. We here meet for the first time with Pentamerus oblongus, Stricklandinia 

lens, S. lirata, S. brevis, and Laptocmlia hemispherica. These are all strongly characteristic of 

the Middle Silurian and occur in this division and also in division 4 in great abundance. 

Division 4.-There are 70 species from this division, of which 26 are received from below. 

CONCLUSION. 

The great abundance of such species as Strophomena rhomboidalis, S. pecten, S. antiq_uata, 

Lept::ena transversal is, Orth is davidsoni, Pentamerus oblong1ts, Strick land in ia lens, S .lirata, S. brevis, 

Oyrtia myrtea, Spirifer plicatella, and Leptocmlia hemispherica, together with the general aspect 

of the whole fauna of divisions 3 and 4, render it quite certain that this part of the series represents the Upper Llandovery rocks of England and, perhaps, the Lower Llandovery also. They 

may not be exactly synchronous, for it seems to be now pretty conclusively demonstrated that 

a fauna may appear somewhat earlier in one region than in another. But, so far as we can at 

present decide the question by fossil evidence, these rocks are of the same age. I use the word 

fauna in a purely zoological sense, with no reference to geographical distribution. With regard 

to the Llandovery formation, Mr. Saltera makes the following remarks: "The Lower Llandovery, or, as I prefer to call it, with Prof. Phillips, the Llandovery rocks, are intimately united 

with the Caradoc, and pass up from them with a great admixture of Lower Silurian, not Upper 

Silurian, forms. The May Hill sandstone, on the contrary, as Sedgwick showed in 1853, is 

unequivocally the base of the UppE\r Silurian, and contains scarcely any true Lower types." 

Now, the only deposit, as yet known in America, which exhibits such an admixture, is division 1 

of the Anticosti group. If, then, the extinction of the Lower Silurian fauna occurred in the 

ancient British seas at the same time that it did in the American waters, it follows that division 1 

is Lower Llandovery; and that the Hudson River is Caradoc. 

It is, however, very difficult to correlate all the divisions of the English Middle and Lower 

Silurian with those of America, and I shall take this occasion to make a few observations on the 

other members of the series not found in Anticosti. From what we know of the origin and mode 

of accumulation of sedimentary strata, it is highly improbable that each of the minor formations 

of one country should have its exact equivalent in another land several thousands of miles away, 

although the larger groups, of which these smaller ones are the component parts, may be well 

represented, and paralleled in a general way. Everywhere we find a number of breaks or gaps, 

and the probabilities are vastly against these breaks having been all occasioned at the same time 

in distant localities. lt is more consistent with the nature of things that many of the breaks 

in America should stand opposite-so to speak-the formations in England, and vice versa. 

Perfect parallelism of the minor groups may be looked for as the exception, not the rule.b 

M-N 13-14. LAKE WINNIPEG, MANITOBA, AND SASKATCHEWAN. 

The Silurian of northwestern Manitoba is a thin-bedded limestone, which varies 

in character from bed to bed. The lower portion, well exposed at Grand Rapids, -------~-

a Geol. ~lag., vol. 3, p. 240. 

b Prof. A. C. Ramsey (Anniversary address to the Geological Society, 1863: Jour. Geol. Soc., vol. 19) gives the 

following account of the brel\ks in the English series from the Lingula flags up to the Wenlock shale; 

Lingula flags. 

Break very nearly complete both in genera and species, and probable unconformity. 

Tremadoc slate. 

Break very nearly complete, both in genera and species, and probable unconformity. 

Llandeilo and Caradoc beds. 

Large broak, especially in species, and probable unconformity. 

Lower Llandovery beds. 

Break and decided unconformity. 

Upper Llandovery beds. 

Break and strong unconformity. 

Wenlock shale, etc. 
262 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

on the Saskatchewan, consists of 54 feet of white or yellow limestone, partly magnesian, partly chalky, and partly ripple-marked and containing impressions of salt 

crystals. The base is not seen, but limestone of Trenton age lies not far below. 

Fossils are lacking in the lower 10 feet but numerous above, and the strata are 

compared by Tyrrell 817 a with the lower part of the Niagara of "\Visconsin. Above 

the lower portion is a considerable thickness, "possibly a few hundred feet," of 

dolomites and dolomitic limestones of upper Niagara age. The beds exhibit impressions of salt crystals and are in some places "fragmental." Tyrrell gives a list of 41 

species of fossils determined chiefly by Whiteaves. Near Lake St. Martin (latitude 

51° 45') the strata of Niagara age rest on granite of an island in the rocks of Trenton 

age, which.elsewhere underlie them. Gypsum occurs not far away. Near by, on 

the eastern shore of Lake Manitoba, "the thin-bedded upper Niagara dolomites 

are overlain by a few feet of a thick-bedded massive stromatoporoid magnesian 

limestone, which yielded a few corals, including Pycnostylus guelphensis." 

N-0 8. SOUTHEASTERN ALASKA. 

The ·wales " series'' of southeastern Alaska comprises argillites, of great thickness but unknown age, and younger limestone, 2,000 feet or more thick, from which 

Kindle 496 lists Silurian fossils.· He says: 

Two horizons of the Silurian have been recognized. The older of these is represented 

by a small fauna which has been found on the northwest coast of Kuiu Island. In the limestones northeast of Mead Point the following fauna occurs: 

Diphyphyllum? sp. 

Conchidium knighti (Sow.). 

\Vhitfieldella sp. 

Holopea cf. servus Barr. 

Murchisonia sp. 

None of the species are abundant, with the exception of 0. knighti, which is represented 

by great numbers of large shells in one thin bed of limestone. 

0. knighti is one of the characteristic fossils of the Aymestry limestone of the Ludlow 

group of England. It is known also from Russia and Bohemia. There appear to be no 

authentic records of its occurrence in the Silurian faunas of the United States. The nearest 

equivalent of this fauna in eastern America is the Niagara fauna. While none of the species 

collected are identical with Niagara species, Oonchidium knighti is very closely related to 

0. nysius of the Niagaran fauna. 

The Kuiu Island fauna occurs in the midst of a limestone series which appears to be 2,000 

feet or more in thickness. Other portions of the series which were examined appeared to be 

barren. Upward these limestones seem to terminate with volcanic breccias, while below they 

pass into cherts and argillites of undetermined age. 

The later Silurian horizon does not appear to be present in the Kuiu Island section. It 

occurs at Freshwater Bay, where more than a thousand feet of gray limestones, which precede 

the beds carrying Devonian fossils, outcrop along the south side of Freshwater Bay. The 

lower two-thirds of this series comprises dark-gray, thinly laminated limestones. Leperditias 

of an undetermined species occur abundantly in certain beds in the lower part of the series. 

A few fragments of another and larger crustacean, probably a Ceratiacaris, are associated with 

them. These crustaceans comprise the fauna of the lower 700 feet of the section, so far as 

discovered. 

In the upper 300 feet of the limestones of the section a crustacean fauna predominates, 

but the types represented are unlike those of the preceding division. One of the conspicuous 

forms in this fauna is a largely undescribed ostracod provisionally referred to Isochilina by 
SILURIAN. 263 

E. 0. Ulrich, having a length of li inches. Fragmentary specimens indicate the presence of 

one or more other species of large ostracods, which together with a new species of Ceratiacaris 

are associated with the large Isochilina. Other forms occurring in this portion of the section 

are Zaphrentis ~ sp., represented by a single specimen, Meristella tumida Dalm. ~'and Megalom:us 

sp. undt. The Megalomus is a large and very thick shelled bivalve comparable in this respect 

with Megalomus canadensis of the Guelph and identical with a species occurring in the limestone at Glacier Bay. 

While none of the forms occurring in the two lowest divisions of this section have been 

identified with known species, the dominance of the large ostracods and the massive-shelled 

Megalomus and thick-shelled Murchisonias point to a late Silurian age of the fauna. The 

horizon represented is apparently about that of the Guelph. 

The Silurian fauna of Freshwater Bay is found also at Glacier Bay, to the northwest. 

A small collection in the National Museum made by Cushman and a much larger collection by 

Mr. F. E. Wright show the faunas of the two localities to bear the closest resemblance. 

The horizon represented by the fauna at Freshwater 1nd Glacier bays is not known as yet 

elsewhere in Alaska. The Kuiu Island Silurian fauna differs very materially in its facies from 

other known Silurian faunas of Alaska, but the same horizon appears to be represented by the 

Silurian found by the writer on the Porcupine River, in northeastern Alaska, during the last 

summer. 

N-0 10. FINLAY AND OMENICA RIVERS. 

Beneath the "Devono-Carboniferous" Banff limestone, in the Peace River pass, 

British Columbia, McConnell 562 b observed beds containing Halysites, which may 

represent the Sil'l.llrian. They apparently correspond with the strata holding a 

similar stratigraphic position and also containing Halysites, which occur east of 

Columbia River on the main line of the Canadian Pacific Railway and immediately 

overlie graptolite-bearing slates of Black River to Trenton age (Normans Kill fauna). 

(Seep. 191.) 

N-0 15-17. SOUTHWEST COAST OF HUDSON BAY. 

The mapping of Silurian rocks on the southwest coast of Hudson Bay rests 

upon collections of fossils from a few isolated localities, which do not suffice to 

delimit the formation in relation to the Ordovician rocks of the same district. The 

most noteworthy of these occurrences is at Port Churchill, where fragments of a 

white limestone yielded fossils related to the Silurian of the Saskatchewan and of 

Anticosti. 818 Farther south the limestones have been observed and fossils collected, 

especially on Ekwan and Attawapiskat rivers. Dowling 291 a states: 

The valleys of all the streams entering the western side of James Bay are cut down through 

the drift deposits to a fiat-lying limestone, which forms a wide belt around the west shore of the 

bay and along the southern shore of Hudson Bay. On the Albany River the upper part of the 

series is proved to be of Devonian age, and beneath, at a greater aistance from sea, Silurian 

limestones are exposed. These beds probably overlap any older ones that may be beneath 

and rest directly on the Archean. 

Descriptions and lists of fossils may be consulted. 291• 

924 

P 6-7. SOUTHERN ALASKA, COOK INLET TO YAKUTAT BAY. 

Metamorphic rocks of sedimentary origin constitute in southern Alaska a great 

and extensively exposed series, the Valdez group, which is probably chiefly Paleozoic 

and includes Silurian, but no definite section can be thus correlated. (See note on 

metamorphic Paleozoic in Alaska, Chapter VII, p. 353.) 
264 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA, 

P 19. UNGAVA BAY. 

Akpatok Island, in Ungava Bay, is described by Robert Bell 68 a, 69 as consisting 

of a great thickness of "Cambro-Silurian" rocks. The fossils which he collected 

are stated to represent the "Hudson River" terrane. 

According to Low, 550 b the fossils of Akpatok Island range from "Lower GalenaTrenton to Lower Helderberg." 

P-R 9-10. BEAR RIVER AND MACKENZIE VALLEY. 

Bear River, the outlet of Great Bear Lake, passes from Cretaceous to Paleozoic 

rocks in cutting through a ridge of which Mount Charles is the highest point in the 

vicinity. J. M. Bell 64a ascended the mountain in 1899 and reports: 

Ordovician or possibly Silurian rocks occur at "The Rapid'' on the Bear River where the 

mountain range crosses it. Mount Charles, the most prominent part of these mountains, is a 

hill of about 1,500 feet in height and consists of a large anticline, embracing subordinate folds. 

The rocks are interstratified conglomerates, quartzites, and magnesian limestones, the latter of 

great thickness. I found thin layers of gypsum in several places, interstratified with dark-gray 

shaly dolomite. · 

Bell does not cite any fossils. Dawson 257c quotes Meek on the Devonian age 

of the limestones of the Mackenzie Valley, which were earlier referred to the Siluri~n 

by Isbister and others. " Amongst all the collections under examination from 

various localities along Mackenzie River and its tributaries, between Clearwater 

River and the Arctic Ocean, a distance by course of the valley of more than 1,000 

miles, there are no Carboniferous or characteristic Silurian forms." If Bell and 

Meek are both correct, the anticline crossed by Bear River brings up Silurian strata 

not generally exposed along the Mackenzie. 

P-S 10-17. ARCTIC REGION. 

The southern islands of the Arctic Archipelago are extensively covered by 

Silurian strata, probably in most places underlain by the late Ordovician, with 

which they constitute the base of the stratified sediments that dip gently northward from the "Laurentian" gneisses of the mainland. These Silurian deposits 

are by their fossils so related to the strata occurring near Lake Winnipeg and in 

the Mississippi Valley as to demonstrate the extent of the sea over northern central 

North America. Waters affording the same habitat and supporting the same 

faunas were continuous to the northern shores of Russia and spread widely over 

Siberia. 804, 876 

Dawson's comments on the views formerly held and now deemed reasonable 

as to the presence of Ordovician strata in the Arctic have already been quoted 

(p. 222). The following account of the Silurian rocks is Haughton's description as 

given by Dawson. 257r 

The Silurian rocks of the Arctic Archipelago rest everywhere directly on the granitoid 

rocks, with a remarkable red sandstone, passing into a coarse grit, for their base. This sandstone is succeeded by a ferruginous limestone containing rounded particles of quartz, which 

rapidly passes into a fine grayish-green earthy limestone abounding in fossils, and occasionally 

into a chalky limestone, of a cream color, for the most part devoid of fossils. The average 

dip of the Silurian limestone varies from 0° to 5° NNW., and it forms occasionally high cliffs 

and occasionally low fiat plains, terraced by the action of the ice as the ground rose from 
SILURIAN. 265 

beneath the sea. The general appearance of the rocks is similar to the Dudley limestone and 

would strike even an observer who was not a geologist. This resemblance to the Upper Silurian 

beds extends to the structure of the rocks on a large scale. Alternations of hard limestone 

and soft shale, so characteristic of the Upper Silurian beds of England ancl America, arranged 

in horizontal layers, give to the cliffs around Port Leopold (northeast part of North Somerset) 

the peculiar appearance which has been described by different polar navigators as "but'tresslike," "castellated;" this appearance is produced by the unequal weathering of the cliff, which 

causes the hard limestone to stand out in bands. 

A few fossils procured by Hall on the west shore of Kennedy Channel, at Cape 

Leidy, Cape Frazer, and other points, were examined by Meek, 584 who reported 

12 species and commented: 

From the foregoing list, it is believed that geologists will agree that the rocks at this 

highest northern locality at which fossils have ever been collected belong to the Upper Silurian 

era. The most remarkable fact, however, is that they are nearly all very closely allied to and 

some of them apparently in all respects undistinguishable from species found in the Catskill 

shaly limestone of the New York Lower Helderberg group. 

Authorities for the distribution of Silurian strata throughout the Arctic region 

are given by Dawson 2576 in his detailed account of the scattered data gleaned by 

him from the writings of many explorers. The localities noted are named below. 

Dawson also gives a list of localities at which fossils haue been obtained. 

P-Q 16-17 ........ ____________ .Southampton Island. 

Q 18-19. __ ... __ ... _____ . __ ... Baffin Land. · 

R 10 .. _____ ... ____ . ___________ Cape Parry; Baring or Banks Land. 

R 14-15 .... __ . ________ ... _____ King William Land and Boothia Peninsula. 

R 17 .......... _ .... _ ..... ___ .. Melville Peninsula. 

R-S 11-13 __ ... _ ... __ .... ____ . Mainland Coast, Wollaston and Victoria lands. 

R-S 14. __ ... ___ ... _ .... __ . __ . Prince of \Vales Island. 

R-S 15-16 .. _____ . __________ .. Gulf of Boothia. 

S 15 .. __ ......... -- ...... _. __ .North Somerset. 

Jones, 472a Salter, 692 and Schuchert 712 may also be consulted. 

Low 550a describes an area of Ordovician and Silurian limestones covering all 

but the northeast coast of Southampton Island, most of Coats Island, and all of 

Mansfield Island and reappearing on Akpatok Island, in Ungava Bay, though not 

seen on the intervening southern shore of Hudson Strait. The fossils from the 

south shore of Southampton Island constitute "a fauna closely resembling that of 

the Lake Winnipeg basin, and extend over a period from the Galena-Trenton to 

the Guelph and Niagara." 

Q 3. SEWARD PENINSULA. 

The N orne group of Seward Peninsula comprises mica schists and probably 

three massive limestones, which, according to P. S. Smith/67 range in age from 

Cambrian to probably post-Ordovician. The Port Clarence limestone is the oldest 

division of the N orne group which is known to contain fossils. The faunas of this 

limestone have been listed by Kindle, 503 who states a that a magnesian limestone on 

Fish River yielded a heavy-shelled lamellibranch comparable with Afegalomus 

canadensis and identical with a species which occurs in the limestone of late Silurian 

age at Glacier Bay and at Freshwater Bay in southeastern Alaska. (See p. 262.) 

a Personal communication, January, 1910. 
266 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

On the map the Silurian is not distinguished, being included in the unaltered and 

probably also in the metamorphosed Paleozoic rocks. 

Q 5-6. YUKON-TANANA REGION. 

The Fortymile group of crystalline limestone and quartzite with some graphitic 

schist was provisionally correlated by Brooks 101a with the N orne group and the 

Skajit formation of northwestern Alaska. Later investigations by Brooks and 

Kindle on Porcupine River have resulted in more definite determination of the 

Silurian age of a massive limestone which may be equivalent to that of the Fortymile group. 

With regard to the Porcupine section, Brooks 102 says: "The Silurian is represented by at least 2,500 feet of magnesian limestone with some quartzites and 

slates, which are probably conformable to the Ordovician. Its correlation with the 

Fortymile series of Spurr is suggested but not proven." 

Kindle 498a gives a list of 37 species collected from this limestone and comments: 

Tile Porcupine River fauna contains species which link it with the Silurian faunas of both 

Europe and America. Of these Rhynchotreta cuneata, Spirifer nobilis, and Pentamerus oblongus 

have long been known in both European and American faunas. The peculiar little twisted 

brachiopod Streptis greyi has been recognized at but one other American locality, however. 

Williams has reported it from the St. Clair limestone fauna of Arkansas. In Europe it occurs 

in the Silurian of Bohemia, in England, and at the island of Gotland. 

The Silurian fauna of the type represented by the species listed here is known to have a 

wide distribution throughout the world. It is well known in various parts of Europe and has 

been recognized in regions as remote as China, New Zealand, and Australia. This fauna occurs 

in a magnGsian limestone of considerable thickness-probably 2,000 feet. It is preceded in the 

section by Ordovician limestones containing Maclureas. It is followed by a somewhat later 

phase of the Silurian and by the Devonian. 

Q-R 5. ENDICOTT RANGE. 

The Skajit formation of the Endicott Range, northern Alaska, consists of heavybedded crystalline limestone and mica schist, in which a few obscure fossils, apparently Silurian, were found by Schrader. 708 

T 16-17. ELLESMERE LAND. 

A thick section of Ordovician, Silurian, and Devonian strata occurs on the 

north shore of Jones Sound, southern Ellesmere Land, and has been described in 

detail by Schei, 550d as follows: 

There are at Havnefjord, in Jones Sound, above some layers of quartz sandstone, which 

entirely cover the gneiss granite there, a series of limestone conglomerates with marly schists 

and pure limestones of a thickness of 1,200 to 1,500 feet. These are again overlain by a series 

of beds at least 2,000 feet thick, of hard, impure limestones, brown or yellowish gray in color 

and often remarkably heavy. 

At South Cape, which is entirely composed of this brown limestone, are found in the lower 

parts Maclurea sp., and Halysites sp., referable to the Middle Silurian [probably Ordovician], 

while west of it, at Bjorneborg, the upper parts of the series contain badly preserved remains 

of Orthocer.ata, corals, and Pentamerus cfr. tenuistriatus. Hereafter the upper part of the 

limestone seems to be equivalent to the older Upper Silurian (L.andovery). This brown limestone occurs from South Cape westward to Kobbebugten, in Hell Gate, .and is broken at Lille 

Sandor, tectonic disturbance bringing up the underlying conglomerate series and even the 

Archean. * * * 
SILURIAN. 267 

On the south side of Rendalen appears the brown limestone of the capes, series A, with a 

flat dip to the north-northwest; but on the north side of the valley is a division of dark schist 

[shale], series B, lying conformably above the beds of brown limestone. Associated with these 

schists, particularly in their lower and upper parts, are numerous layers of pure dark limestone, 

frequently fossiliferous. In Rendalen and in Kobbebugten, where this same division also 

appears, a quantity of material was collected, of which 15 species are provisionally determined, 

among them being Favosites sp., Strophomena cfr. euglypha, Neristella in numbers, Rhynchonella 

cfr. borealis, Pentamerus cfr. galeatus, Spirifer cfr. elevatus. The period of this division in 

series B is Wenlock. 

The upper part of series B appears, among other places, at the headland north of Tunneldalen, in Hvalrosfjord. Above a black shale containing .Monograptus sp. and Leperditia 

cfr. phaseolus is a bed of fragmentary limestone with Favosites, Strophomena cfr. pecten, Atrypa 

reticularis, Pterinea cfr. sowerbyi. From a locality in Gaasefjord, on the same horizon, were 

taken Favosites cfr. hisingeri, Favosites gothlandicus, Thecia swinderenana, Spirifer elevatus, 

Spirifer cfr. crispus, Strophomena corrugatella Dav., Pterinea sp. According to these, the 

period of this upper part of series B should be Ludlow. The thickness of the series is about 

1,000 feet. 

In Hell Gate, as well as in Gaasefjorcl, these strata are overlain by series C, in its lower 

parts consisting of interstratifiecl light and dark marl schists, which are somewhat sandy, 

while in its upper part appear pure quartz sandstone beds and argillaceous sandstone. The 

collective thickness of these strata is about 1,000 feet in Gaasefjord, while in Hell Gate it is 

probably somewhat greater. No fossils were found in this series. 

At the base of the high cliffs at Indra Eide and Borgen appears series C. In both these 

places it is overlain by a dark limestone and black shale, partially fossiliferous. This dark 

limestone and shale are the lowest layers in a series of strata at least 1,500 feet in thickness, 

series D, which appears in the profiles on both sides of Gaasefjord, from Borgen to the foot of 

Vargtoppen (Wolf Top), and from Indra Eide to Skrabdalen. 

In series Da occurs Atrypa reticularis in great quantities, but little else. On the other 

hand, there are preliminarily determined in Db about 55 species, of which may ba mentioned 

Favosites sp. div., Columnaria sp., Cyathophyllum sp. cfr. hexagonum, Receptaculites sp., 

Fenestella sp., Homalonotus sp., Burmeisteria sp., Dechenella sp., Proetus sp., Orthis striatula, 

Leptoona sp., Strophomena, Streptorhyncus, Atrypa reticularis aspera, Rhynchonella (Pugnax) 

cfr. reniformis pugnus, Productus cfr. prolongus, Spirifer of the verneuilli :Murch. type, a peculiar 

Pentamericle, Terebratula cfr. Dielasma, Pterinea sp., Modiolopsis sp., Lucina sp. div., Bellerophon sp., Platyceras sp., Orthoceras sp., Gomphoceras, gigantic nautilus, and ganoid scales. 

The fauna in De is merely a repetition and, in the case of certain species, a further development of the forms found in Db. It will thus be seen that there is a spring in regard to the fauna 

between the upper layers in series B and the lower ones in series D, which more particularly 

resemble Lower or Middle Devonian. The concordantly embedded(?) series C might, therefore, be thought to represent uppermost Silurian as well as lowest Devonian. 

Divisions Dd and Df are poor in fossils and are partly shale divisions. In the impure 

limestone of Dg occur again numerous fossils, among which are Atrypa reticularis, Rhynchonella cfr. cuboides, Spirifer cfr. undifera, Productus sp., Terebratula cfr. Dielasma, Pterinea 

sp., Avicula sp., Modiolopsis sp., Pleurotomaria sp., Proetus sp. Traces of placoderm fish 

are also met with. Above these strata are beds of pure limestone, Dh, and above these again 

some less pure, Di. The uppermost strata of Di alternate with strata of light-gray quartz 

sandstone terminating in a day sandstone, which in places is richly fossiliferous, though the 

fossils are in a bad state of preservation. Among these are Lamellibranchiata, Dechenella 

sp., remains of Holoptychius, etc. 

This argillaceous sandstone is simultaneously the last link in series D and the first in 

series E. This is a huge collection of quartz sandstone strata building up the mountains 

on both sides of the inner part of Gaasefjord. The lowest part, which is 900 to 1,200 feet in 

thickness, consists almost exclusively of quartz sandstone. On the north side of Skrabdaien 
268 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

in the sandstone profile, occur conglomerate strata, half an inch to an inch in thickness. In 

these were found considerable remains of Coccosteus sp., Holoptychius sp., and Modolia angusta. 

In the same strata with these were also seen indeterminable plant fossils. Slightly higher up 

in the profile, however, in a black shale which occurred in two lentiform masses, 18 inches and 

6 feet in thickness, were found numerous plant fossils. 

Prof. Nathorst, of Stockholm, who has kindly undertaken the examination of these, says 

that among others are Archmopteris .fissilis Schmall1. and Arch. archetypus Schmalh., both 

characteristic of Upper Devonian. In examining the material collected, Prof. Nathorst also 

found with the plant remains some remains of fishes. 

Low/50e who quotes the foregoing description from Schei, comments on it as 

follows: 

From the above it will be seen that on the southern side of Ellesmere there is a complete 

succession of strata, bearing fossils from Middle Silurian age up to the Upper Devonian. These 

strata have an agg.regate thickness of 8,000 feet and form the thickest and most carefully 

measured section of the Silurian and Devonian beds of the Arctics. 

The southern shore of Jones Sound presents a different section, which is thus 

described by Low: 550 f • 

On the southern and southwestern parts of North Devon the Silurian strata are much 

thinner than those described by Schei. At Cuming Creek the Archean gneisses were found 

overlain unconformably by red and purple arenaceous shales and thin-bedded sandstones 

having an aggregate thickness of 50 to 100 feet. These in turn were succeeded by beds of 

impure limestone of light-gray or creamy color. The beds are usually under 2 feet in thickness 

and separated by thinner beds containing a considerable amount of clay. These light-colored 

limestones have a thickness of over 1,000 feet in the cliffs on both sides of the creek. The 

sides of the cliffs are covered with broken limestone, so that it was impossible to measure a 

section up them, but in two or three places a darker-colored limestone conglomerate was found, 

made up of small pebbles cemented by a dark shaly matrix. Fossils are only found in the beds 

immediately overlying the dark shales and sandstones of the base. These show that the lower 

limestone is of Silurian age, about the horizon of the Niagara. 

Similar conditions prevail in the cliffs at Beechey Island, where a large collection of fossils was obtained from the lower limestone beds, while others, picked up loose but evidently 

fallen from the cliffs above, showed that the upper beds pnssed close to if not into the Devonian. 

Similar Silurian limestones constitute the island of Cornwallis, to the westward of ~ orth 

Devon, while in the remaining Parry Islnnds farther west the Silurian strata are lost beneath 

the Devonian and Carboniferous rocks of those islands. 
Color, dark blue. 

Symbol, 15. 

CHAPTER VI. 

DEVONIAN. 

Distribution: Eastern-central United States, eastern Canada, northwestern Canada, and 

Cordillera of the United States, Canada, and Alaska. 

Content: Devonian as commonly defined through the Appalachians, including Helderberg 

at the base and higher formations to Chemung and Catskill, inclusive; in the northeast, from 

Gaspe to New York, Helderberg is included with the Silurian in mapping; in the Appalachian 

zone south of latitude 38°, the Devonian color on the map includes Silurian; throughout the 

Cordillera from Mexico to Alaska the Devonian where present is mapped with Carboniferous 

undivided (14), except that it is distinguished in the Klamath Mountains, California . 

• Devonian areas. 

Page. 

H-I 12 ......................... Southern Arizona and northern Sonora .. _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271 

I 12 .......................... Arizona . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272 

I 12-13 ................ , ...... South western ~ ew Mexico ...... ' .......................................... _ 273 

I 14-15 ....................... Southern Oklahoma (mapped with Silurian) ........................ _ .... _.. 273 

I 15 .......................... Arkansas (not mapped) ................................................ ___ . 274 

I 16, J 17 ..................... The Appalachian Valley................................................... 274 

I-J 16 ................... , .... Tennessee, Kentucky, and northwestern Alabama.-,-... . . . . . . . . . . . . . . . . . . . . . 275 

J 15-16 ....................... Missouri and Illinois..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278 

J-K ll-12 ..... ---------- .. _ .... Great Basin, Nevada and Utah ........................... ------............ 282 

J-K 12-13 ...................... Wyoming and Colorado (mapped with Carboniferous) ............ _ .. ."..... . . 284 

J-K 17-18 ..... ---------- ....... Southeastern Penl)sylvania, Maryland, and Virginia......................... 285 

K 10 ........................... Klamath Mountains, northern California ................................... _ 288 

K 15 ........................... Iowa ...... _.............................................................. 290 

K 16 ........................... vVisconsin .......................................................... _. __ . . 290 

K 17 ........................... Ontario ............................................................... __ . 291 

K 17-18 ........................ Pennsylvania and ~ew Jersey; New York ......... __ ............... ___ . __ ._ 293 

K-L 16-17 .................... Michigan, Indiana, and Ohio .......................................... __ .. 313 

L 12 .......................... Southwestern Montana (mapped with Carboniferous)........................ 319 

L 18 .......................... St. Helens Island, Montreal (not mapped) ............................. __ .__ 324 

L 18-19 ....................... Quebec, southeastern towmhips (not mapped) ................. __ ........... 325 

L 19 .... __ .................... Southern New Brunswick and eastern Maine ........ ----.................... 325 

L 20 .......................... Nova Scotia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 

M 11 ........................... Rocky Mountains of British Columbia (not mapped)......................... 333 

M 19 ........................... Northern New Brunswick . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333 

M 20 ................... _ ........ Gaspe Peninsula .................................................... _ . ___ . 334 

M-N 14 ....................... Manitoba ............................................... --------.......... 335 

M-N 16-17 .................... James Bay, Ontario....................................................... 335 

N 9, 0 8 ...................... Southeastern Alaska (not mapped) ............. · ....................... _ . . . . 336 

N-0 12-13. _ .................. Alberta and Saskatchewan................................................. 336 

0-Q 9-12 ...................... Mackenzie Basin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336 

P 4--5 ......................... Alaska Range and southern Alaska ................. __ ...................... 337 

P 8 ........................... Yukon Territory (mapped with Paleozoic undivided)........................ 338 

Q 3 ............................ Seward Peninsula (not mapped). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . :138 

Q 6-7 ................. _ . _ ...... Yukon-Tanana region ............................................. _ . . . . . . . 338 

Q 8 ............................ Peel River (not mapped). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340 

Q-R 5 ......................... Endicott Range (not mapped) ............................ _ . . . . . . . . . . . . . . . . 340 

R 3 ........................... Cape Lisburne. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341 

S 27 .......................... Eastern coast of Greenland.................................... . . . . . . . . . . . . 341 

S-U 15-20 ..................... Arctic Archipelago and northwestern Greenland...... . .. . . . . . . . . . . . . . . . . . . . 341 

269 
FIGURE 8.-Sketch ;nap showing the distribution of Devonian rocb represented on the geologic map of North 

America and the ·key to references in the text. 

270 
DEVONIAN. 271 

H-1 12. SOUTHERN ARIZONA AND NORTHERN SONORA. 

The sections at Globe and Bisbee, described by Ransome, 657a, 659 include limestone 

which contains late Middle or Upper Devonian fossils. At Globe the formation is 

continuous upward with Carboniferous (Mississippian) limestone, as are the Ouray 

limestone of Colorado and the limestones described by Dumble. 296 

At Bisbee the Martin limestone (Devonian), 340 feet thick in the type section, is 

distinguished from the Abrigo limestone (Cambrian) below and the Escabrosa lime·-

stone (Mississippian) above it. The fauna is described and correlate<;! by Williams,658b 

who concludes that its affinities are with the Neo-Devonian of New York but that in 

Meso-Devonian time the fauna occupied the Arizona province in migration from 

Russia. 

Williams comments on the fauna as follows: 

The species Atrypa reticularis is present in 25 of the 30 faunules. Some one or more of 

the corals are found in 11 of the faunules. [Six of] the faunules * * * contain several 

species of the reef-building corals and probably represent a common fauna. 

Associated with these corals are species a which indicate distinctly the fauna so well developedin the Devonian rocks at Rockford, Iowa. On the supposition that Spirifer hungerjordi and 

Spirifer whitneyi ar~ characteristic species of that fauna, the following species, associated with 

them in the Bisbee quadrangle, are now added to it-that is, Dielasma cal1:ini, Productella 

speciosa, Spirijer cf. jeremejevi. These twelve species, at least, are therefore probably present 

in a common fauna of this Arizona region, which is also represented in Iowa, and is certainly of 

Devonian age. 

Its comparison with New York and northern Appalachian faunas indicates close affinity 

with a fauna occurring at the base of the Chemung formation of New York, above the typical 

Ithaca formation. In the High Point zone of Naples, Livingston County, N. Y., the species 

of the genus Strophonella reported is S. reversa. The form reported in the above list is S. 

cmlata, which occurs in the Stropheodonta cayuta fauna of the southern counties of New York 

and across the border in Tioga and Bradford counties, Pa., but not, so far as I have observed, 

in the High Point fauna. In this southern extension it is associated with typical Spirijer 

disjunctus. The Productella of the Arizona region is also of the same type as that represented 

in this upper (Chemung) zone rather than in the underlying typical Ithaca zone of Productella 

speciosa. The evidence is therefore confirmatory of the opinion that this western American 

fauna did not reach the upper Appalachian region, in its full complement, until after the deposition of the zone of the Ithaca formation. 

It is to be observed, however, that in Russia the fauna with which this Arizona fauna shows 

closest affinity is classed by Tschernyschew as middle Devonian rather than upper Devonian and 

occurs below the Cuboides fauna. It is also regarded by him as equivalent to the Stringocephalus 

fauna, which in western Europe is strictly Mesodevonic. This is further correlated by Tschernyschew with the Hamilton group of North America. 

* * * * * * * * * 

There can be little doubt as to the close affinity of the Arizona and Russian faunas 

here referred to. Comparison of Spirifier hungerjordi, as it occurs both in Iowa and Arizona, 

with Russian specimens of Spirijier anossofi demonstrates the two to be closely related, as 

Tschernyschew maintained; but the rounded cardinal angle as well as coarser radiating strire 

mark the figures of S. anossofi of Tschernyschew (as well as actual specimens seen by me), 

from the Sp. hungerjordi as it is seen both in Iowa and Arizona. There are figures in the original 

a For list see the work cited.-B. W. 
272 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA, 

description of De Verneuil, which have the angular terminations of the cardinal area. Also 

some young specimens from Iowa in my collections• show distinctly rounded cardinal angles. 

Associated with that species are Productus hallanus and Rhynchonellas of the Pugnax 

type (R. acuminata), which distinctly belong to tlus fauna as developed in America. 

As I have reported in other places, this Pugnax pugnus fauna occurs in the New York 

section, both in Ithaca and High Point zones, willch are both above the representative of the 

Cuboides zone (Tully limestone) of that region, and before the appearance there of the typical 

Spirijer disjunctus fauna. But in K ew York the species which dominates in the Iowa, Arizona, 

and Russian faunas (Spirifer hungerjordi and Spirijier anossofi) is entirely absent, or certainly 

very rare even if eventually it should be. discovered. From this and other sinlilar peculiarities 

presented by the New York faunas, I am inclined to think that the horizon at which the Pugnax 

fauna enters the New York sections is later chronologically than that of the formations holding 

the fauna in Russia, and possibly also appreciably later than the zone marked by it in Iowa 

and Arizona. ' 

Although Spirijer whitneyi presents many characters of the general Spirifer disjunctus 

type, its range in the Russian and also in the west European Devonian confirms tills same 

view. The Arizona fauna does not present any very close affinity with the distinctly Chemung 

(Spirifer disjunctus) fauna of New York. 

Tills earlier age for the Spirifer hungerfordi fauna is also indicated by the development 

of Productus. All the representatives of that genus reported from Arizona and from the same 

fauna as expressed in Iowa indicate an earlier stage of its development than that exillbited 

by the Productellas of the Chemung formation of New York. 

From these and other considerations it seems reasonable to adopt Tschernyschew's view 

that the zone in Russia containing the anossofi fauna is the equivalent of the Stringocephalus 

zone of western Europe as well as of the Hamilton formation of North America; and therefore 

that the fauna is properly a Mesodevonian rather than Neodevonian fauna. On these grounds 

we should place the formation bearing tills fauna in Arizona in the Mesodevonian, although 

its representatives do not appear in the New York fauna until the opening of N eodevonian 

time. 

The stratigraphic relations of the limestones at Globe and Bisbee exhibit 

a hiatus from Cambrian to Devonian but tqe strata are apparently conformable 

throughout to the close of the Carboniferous. 

In the Clifton-Morenci district Lindgren 541 found a formation, the Morenci, 

which consists of 75 feet of compact fine-grained argillaceous limestone below and 

100 feet of clay shale above. The strata are conformable to the Ordovician and 

Carboniferous. They have yielded a meager fauna, which indicates a Devonian 

horizon, though it might be Silurian or Carboniferous. 

I 12. ARIZONA. 

Reagan 663 states in regard to the Devonian of the Fort Apache regwn, m 

Arizona: 

Immediately overlying the Silurian on the periphery are alternating chert and flint strata 

followed by massive, very fossiliferous light-colored fine-grained marble limestone, which in 

turn is followed by a grit. This formation, like the Silurian, is exposed as a narrow strip 

encircling the Ellison dome from the Nan tan Mountains on the southeast around by the northeast to the Tonto Basin, where it forms one of the "rim" series of that basin. The strip thus 

formed is sometimes more than 3 nliles wide, though it is usually much less. Besides this 

belted strip several of the buttes of the Tonto region belong to this formation, one of which 

is situated 3 miles northeast of Ellison. This butte is called Juniper Butte on the Government 
DEVONIAN". 273 

maps, but among the settlers it is called Shell Mound, because of its numerous shell fossils. 

The formation is Devonian, as is indicated by the fossils obtained, Orthis livia, Spirifer fornacula, 

and Acervularia davidsoni, and corresponds very much to the Devonian formation at the falls 

of the Ohio. 

I 12-13. SOUTHWESTERN NEW MEXICO. 

At Kingston, N. Mex., in the southwestern part of the Territory, Gordon 

and Graton 372 observed the occurrence of Devonian limestone similar to the Ouray 

limestone of Colorado. The fauna of the Ouray has recently been figured and 

described by Kindle. 501 Lindgren 542c states: 

The Devonian is present in an area extending from the Mimbres Mountains westward to 

the Arizona line and everywhere appears as a thin formation of dark clay shales, usually 

calcareous in the upper portion. The maximum thickness (465 feet) was noted at Silver City. 

In the Mimbres Range, where Gordon has given the name Percha shale to the formation, it 

is only 200 feet thick and its upper part contains a rich and characteristic Devonian fauna. 

The Devonian is not present in the Franklin ::\fountains of Texas but appears with a thickness 

of 200 feet at Clifton, Ariz. The Devonian shale is believed by Gordon to overlie the Ordovician 

limestone with an unconformity of erosion, but the shale and underlying limestone are conformable at Georgetown, Lone Mountain, and Silver City, and also at Clifton, Ariz. At any 

rate the Devonian period in southern New Mexico was characterized by shallow muddy 

deposits, uniform over a large area. 

I 14-15. SOUTHERN OKLAHOMA. 

Taff and Ulrich sosc distinguished "Siluro-Devonian" and late Devonian and 

early Carboniferous strata in the Arbuckle Mountains. The "Siluro-Devonian" 

rocks were mapped as the "Hunton limestone" and include strata which carry 

faunas ranging from Clinton to Oriskany. (See pp. 228-230, Chapter V.) The late 

Devonian and early Carboniferous strata are the Woodford chert, which is 

described as follows: 

Excepting the flinty Oriskany limestone occurring ~ocally at the top of the Hunton limestone and possibly the Helderberg member of the latter, Devonian rocks in the Arbuckle region 

are limited to a single formation of chert and black shale, known as theW oodford chert. ·while 

this chert is apparently conformable with the limestone below in any single locality, it appears 

that this is not true in a broad sense. The Oriskany beds at the top of the Hunton limestone, 

consisting of several feet of cherty limestones, are present in one place but do not occur in another. 

In the northeastern part of the uplift, notably near Franks, cherty limestones are present at the 

top of the Hunton. Near the western end of the uplift, on the southern side of the ·w·ashita 

Valley, this upper member of hard limestone is absent and the thickness of the entire formation 

is reduced· to a little over 100 feet. In all places there is an abrupt change in sedimentation 

from the top of the Hunton limestone to the chert or shale of the Woodford formation. 

The Woodford chert has an estimated average thickness of 650 feet. It varies somewhat 

in lithologic character. In places massive chert rests upon the limestone; in other places black 

shale occurs at the base of the formation. As a rule, however, the formation becomes less cherty 

from the base upward. It is usually even bedded, occurring in layers from a few inches thick t~ 

thin laminre. In places, especially in the northeast side of the uplift, the formation is composed 

almost entirely of thin, fissile siliceous and distinctly bituminous black shale. In this part of 

the region, a few miles west of Hunton, lentils of almost pure flints were noted interstratifi.ed 

with the black shale near the base. In the western part of the region bluish shales were seen 

48011°--12----18 
27 4 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

interstratified with the black shale in the upper part of the formation. At various positions 

in the section, especially in the more cherty beds, are small, rounded, marble-like concretions 

of a calcareous nature. In places there are large segregations of a similar character, concentrically banded, which occur intersecting several layers of cherty shale. 

* * * * * * * * * 

Fossils are very rare in the Woodford chert, and those found are not well preserved. In 

the lower part of the formation in the western part of the region a small Lingula of the type 

L. spatulata Hall and a few conodonts have been observed. In the shales of the upper part the 

only recognizable fossils seen are two concentrically plicated species of Productella, one of 

which seems referable to P. concentrica Hall. 

* * * * * * * * * 

This formation is believed to be of the age of the Chattanooga formation of Tennessee, 

the Ohio shale of Ohio, and the Portage and Chemung of New York. At the top it doubtless 

includes strata corresponding in age with the Noel shale of northern Arkansas and the basal 

shale of the Tullahoma formation of Tennessee, which are believed to be of Kinderhook age, or, 

according to the present classification, earliest Carboniferous. 

At present it is not possible to determine the exact parting between the Devonian and 

Carboniferous, since there is no clear stratigraphic distinction in the shales, and fossils are rare. 

I 15. ARKANSAS. 

The Chattanooga shale (Devonian) is represented in northern Arkansas 6

• 656 

together with a local basal member known as the Sylamore sandstone. The formation consists of a persistent black shale, with locally a dark phosphatic sandstone 

or conglomerate (Sylamore member) at the base, and represents a late stage of 

advance of the sea upon the Ozark land. In places it reaches a maximum thickness 

of 150 feet, but the areas are too small to be shown on the map. 

I 16,.J 17. THE APPALACHIAN VALLEY (ALABAMA, GEORGIA, TENNESSEE, THE VIRGINIAS, 

AND MARYLAND). 

Along the trend of the Appalachian Valley and :Mountains the Devonian 

formations exhibit a very marked change. In Maryland their sequence is still 

complete from the Helderberg limestone up and their thickness in Allegany County 

is 7,875 to 10,200 feet; but they thin out toward the south, the lower formations 

appear only locally or not at all, and in Georgia and Alabama the Upper Devonian 

(Chattanooga shale) overlaps unconformably upon older strata and is reduced to 

a thickness of 10 or 15 feet only. 

The Maryland section is typical for adjacent areas of Pennsylvania and Virgmia. Prosser 646a in 1901 summed up the results of investigations carried on by 

the Maryland Survey. He describes the Helderberg limestone (upper part of the 

Lewistown limestone), as thin-bedded bluish-gray ringing limestone, more or less 

shaly, 400 feet thick, followed by massive darker-blue limestone to a total thickness 

of 750 to 900 feet. The strata are fossiliferous and according to Prosser comprise 

representatives of the Manlius, Coeymans, New Scotland, and Becraft limestones of 

the New York section. The Cayugan strata (Manlius of Prosser) are now separated 

from the Helderberg in Maryland. 

The Oriskany sandstone Prosser describes as bluish-black cherty limestone, 

75 to 100 feet in thickness, above which comes a white calcareous sandstone 
DEVONIAN. 275 

350 feet thick, the whole the equivalent of the New York Oriskany and the same 

as "the Monterey sandstone of the Piedmont folio." 

The Romney shale is described by Prosser as consisting of thin black shales, 

sharply distinguished from the Oriskany, followed by drab and bluish argillaceous 

to arenaceous shales and thin sandstones, the whole 1,600 to 1,650 feet thick, and as 

representing the Marcellus and Hamilton of New York. Kindle 502 has since differentiated the Onondaga in Maryland at the base of the Romney. 

Of the Jennings formation, the lower part is composed of thin black argilla-

'ceous shales, regarded by Prosser as the equivalent of the Genesee shale of New 

York; followed by olive to bluish argillaceous shales, regarded by Prosser as representing the Naples of the Portage of New York, and green arenaceous shales, 

containing a Chemung fauna; the total thickness is 3,800 to 4,000 feet. 

The Hampshire formation is described by Prosser as consisting of alternating 

red, flaggy, and massive sandstones and arenaceous or argillaceous shales, 2,000 

feet thick, equivalent to part of the Catskill of New York. 

An important description of the Lower Devonian and Silurian of Maryland 

is given by Schuchert/14 who lists the species of each horizon and correlates the 

strata with the New York section. 

I-J 16. TENNESSEE, KENTUCKY, AND NORTHWESTERN ALABAMA. 

The Devonian formations of Ohio and Indiana thin toward the south where 

they lap unconformably upon the low land surface of Silurian limestones. Kindle 493a 

states: 

The Devonian formations below the New Albany shale are frequently entirely absent in 

the Kentucky sections, and where present they are usually represented by only a few feet of 

strata. The Sellersburg beds have not been seen south of Louisville. The attenuated character 

of the lower Devonian beds in Kentucky has been generally explained as due to thinning out. 

Prof. N. S. Shaler Uid not recognize any stratigraphic break at the base of the New Albany shale 

and regarded it as the equivalent of the New York Devonian formations down to the Oriskany, 

where the Corniferous was wanting in the Kentucky section. The writer has found sections which 

show unconformity between the New Albany shale and the beds below in Kentucky. This 

interval of erosion which has been detected at the base of the Black shale explains the entire 

absence of the Devonian limestone at many localities and its extreme thinness where present. 

According to Schuchert 711ct and Foerste 340b the Devonian formations in western 

Tennessee represent, where present, Helderberg, Oriskany, Onondaga, and later 

Devonian time, the highest strata being the ,black Chattanooga shale. The distribution of these strata is very irregular. In many places they are absent and locally 

they are represented only by beds from 1 foot to a few feet in thickness. Their normal 

sequence is as follows: Linden formation (basal Helderbergian age), Camden chert 

(lower Oriskany age), limestone of Onondaga age, and Chattanooga shale, with 

phosphatic beds at its base and Hardin sandstone member and shales above. 

The following notes on the Linden are abstracted from the article by Foerste: 

The Linden at Perryville, Tenn., immediately succeeds the Brownsport (Silurian). It consists of "fairly solid crinoidal rock," 10! feet, at the base, with comparatively few fossils 

(Orthothetes worthanus, Rhipidomella oblata, and Striatopora issa); softer, partly crinoidal, partly 

fine-grained rock more or less interbedded with clay, 11! feet, richly fossiliferous (Stropheodonta 
276 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

beckei, Strophonella punctulifera, and Orthothetes woolworthanus, common; Dalmanites micrurus, 

not rare; Vncinulus schucherti, very scaree); fossiliferous clay, 15 feet; overlain by thin limestone layers, 1 t feet, full of bryozoans. Upon these lies,a sandy bed, which may be the Hardin 

sandstone member, the Camden chert being absent. 

In other local sections noted by Foerste the Linden varies in thickness, being 101 

feet at Pyburn Landing, on the Tennessee, and thinning rapidly eastward. It is 

succeeded in some places by the Camden chert, in others by the Hardin sandstone 

member. 

The Camden chert was first distinguished by Safford, who recognized the 

Oriskany facies of its fauna. It is 60 feet thick at Camden, Benton County; is strongly 

developed west of Tennessee River in Henry, Benton, and Decatur counties; and 

thins toward the east. The Camden fauna was collected and studied by Schuchert, 711" 

who states: 

The fossils of this formation are, as a rule, natural casts both of the interior and exterior of 

the organism, and preserve in detail the finest markings. This fauna is closely related to that 

described by Meek and Worthen a from the "Clear Creek limestone" of southern Illinois, in 

Alexander, Jackson, and Union counties. From this region are known but 11 species, and 8 of 

these are also found in Tennessee. They are Anoplia nucleata, Anoplotheca flabellites, Eatonia 

pecularis, Spirijer worthenanus, S. hemicyclus, Megalanteris condoni, Amphigenia curta, and 

Strophostylus cancellatus. 

The "Clear Creek limestone" of Illinois is intimately connected with the Helderbergian 

below and is not less than 200 feet thick, being followed by a" quartzose sandstone" from 40 to 

60 feet in depth. The latter is probably equivalent to the Upper or typical Oriskany of New 

York and does not appear to be present in western Tennessee. From Prof. Safford's description 

of the Camden chert, it is evident that the Lower Oriskany thins r.apidly southward. In Tennessee 

it is about 60 feet in thickness, while it is not less than 200 feet thick in Illinois, exclusive of the 

Upper Oriskany, which is entirely absent in the former State. 

The Camden chert fauna contains 32 species, and 6 of these are restricted to southern 

Illinois and western Tennessee. Of the entire fauna, 24 species are found eit.her in the Helderbergian or in the Lower Oriskany of other regions, and 20 occur in the Upper Oriskany, or 

Onondaga. After removing the 13 species common to both the Lower and Upper Oriskany 

and the 2 restricted forms, 17 remain. Of these 10 occur either in Helderbergian or Lower 

Oriskany rocks of other regions, while 6 are found in higher beds. This evidence, therefore, indicates clearly a Lower Oriskany age for the Camden chert of Tennessee and the "Clear Creek 

limestone" of Illinois, which indication is the more marked because of the absence of such 

characteristic Upper Oriskany species as Hipparionyx proxirims, Ohonostrophia complanata, 

Spirifer arenosus, Rensselaeria ovoides, Meristella lata, Oamarotmchia pleiopleura, 0. barrandei, 

or 0. speciosa. 

Concerning the representative of the Onondaga in western Tennessee, Foerste 340c 

says in part : 

On the western flank of the Cincinnati geanticline, along Harpeth River, between Newsom 

and the bridge west of Pegram, the Silurian is directly overlain by a thin bed of Devonian limestone, varying in thickness from 12 feet at the west to 3 feet at the most eastern point of outcrop. 

* * * Nucleocrinus (Olivanites) verneuili is a characteristic species. Stropheodonta demissa, 

Stropheodonta perplana, Rhipodomella penelope, and Nucleospira concinna are also found. This 

white and comparatively pure limestome is overlain by a darker and more sandy limestone. 

a Geol. Survey Illinois, vols. l, 2, and 3. 
DEVONIAX. 277 

Foerste notes another occurrence, 4 miles north of Bakerville, where a limestone 

3 feet thick has yielded Heliophyllum and Blothrophyllum, closely resembling forms 

in the "Corniferous at the Falls of the Ohio, Louisville, Ky." Several species of 

Cystiphyllum, Cyathophyllum, and Cladopora, a very large form of Atrypa reticularis, 

and Reticularia fimbriata were found. These occurrences he correlates with the 

Jeffersonville limestone of Kentucky and Indiana, regarded as the equivalent of the 

Onondaga limestone of the East. 

The Chattanooga shale and its members, the Hardin sandstone and the Maury 

green shale of Safford, in western Tennessee are described by Hayes and Ulrich 4310 

as follows: 

Excepting the bottom and top, which will be described separately, the mass of this formation 

is a nearly black, rather tough bituminous shale, splitting generally into thin plates. It is the 

well-known and sharply defined formation so often called the Black t!ht~.le. The formation as a 

whole is remarkably persistent in its distribution, being found nearly everywhere in Tennessee 

and adjoining States to the south, west, and north, where its proper horizon is exposed. Its 

occasional absence is due either to nondeposition 'or to erosion preceding Carboniferous deposition. 

Generally throughout middle Tennessee there is at the base of the formation a thin bed which 

is entirely different in character from the black shale above. In the western part of the Columbia 

quadrangle, particularly in the valley of Swan Creek, this bed consists largely of calcium phosphate and forms the source of the Tennessee black phosphate. Its appearance varies somewhat 

from place to place, as well as its chemical composition. It may be gray, bluish black, or black 

in color, and it may be composed of grains large enough to be seen by the naked eye or may have 

a dense, fine-grained structure. When examined with the glass small oval grains are generally 

found to be more or less abundant, sometimes making up the mass of the rock. These have 

polished surfaces and a brown or amber color. In many cases they are the casts of minute coiled 

shells. The phosphate bed passes by gradations laterally into a bed of coarse sandstone or 

conglomerate containing varying amounts of phosphate. The grains are in part phosphatic 

ovules and in part quartz, with less abundant waterworn fragments of other rocks and fish bones. 

The phosphate bed is also replaced, particularly toward the southwest, in Hardin, Wayne, and 

Perry counties, by a fine-grained gray or black sandstone, which reaches a maximum thickness 

of 12 feet in Hardin County, where it has been called the Hardin sandstone by Safford. It may 

consist of a single massive bed or may have a shaly structure, and is generally more or less 

phosphatic. 

It is evident that the black phosphate, the conglomerate, and the fine sandstone are merely 

three phases of the same member.of the Chattanooga formation and represent deposition during 

approximately the same time, their difference in composition being due to differences in the 

sources from which their materials were derived. Occasionally, and this is particularly true of 

areas in which the Chattanooga formation rests on the Clifton and Fernvale formations, the 

conglomeratic phosphate layer is replaced or represented by black shale like that making up the 

body of the formation. Except in these cases the basal bed everywhere follows a more or less 

easily determined unconformity, and was deposited over a nearly submerged land surface. This 

subsidence began in the Oriskany and, continuing through the Onondaga and Hamilton ages, 

resulted finally in the submergence of the whole of the middle Tennessee dome. This submergence occurred in the Portage and continued through the Chemung, these late Devonian 

ages being represented by the Chattanooga shale. 

At the top of the formation there is very generally a thin stratum of greenish shale and 

earthy sandstone, which has recently received the designation "'Maury green shale" from 

Prof. Safford. He says it ranges "from a few inches to 4 or 5 feet in thickness;" but so far as 

our observation is concerned, it does not exceed 2 feet in this area and usually varies between 

12 and 18 inches. ~early always this green shale has embedded in it smooth dark nodules or 
278 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

concretions of lime phosphate. The nodules vary greatly in size, shape, and relative abundance. 

Some are spherical and from a half to several inches in diameter; others are flattened or irregular 

ellipsoids, sometimes as much as 2 feet in length and over 6 inches thick; and they may be 

loosely disposed in the shale, or closely packed. The green color is due to the presence of 

glauconite or greensand, a silicate of iron and potash. Rarely, as in the upper part of East 

Fork of South Harpeth Creek, the green shale is absent or not distinguish<tble, and in these 

cases the black shale seems to pass very gradually into overlying green shale, which constitutes 

the base of the full Tullahoma section. 

Fossils are almost if not entirely restricted to the lower member of the Chattanooga formation. In the dark-gray variety of phosphatic rock, which is really a conglomerate, casts of 

minute coiled and bivalve molluscan shells) washed out of the Ordovician rocks forming the 

surface of the land that was being gradually submerged, are very abundant. Waterworn bones 

of large fishes not infrequently occur with them. In the basal shale and fme-grained sandstone 

a species of Lingula, probably L. spatulata, is frequently seen, while the shiny teeth, jaws, 

and cephalic plates of conodonts, supposed to be small fishes related to myxinoids, are often 

found, sometimes in great numbers. 

In the table of correlations of the Columbia folio 431 a the Chattanooga shale of 

western Tennessee is placed as the equivalent of the Portage and Chemung of New 

York. 

J 15-16. MISSOURI AND ILLINOIS. 

A narrow belt of thin Devonian strata extends from southern Illinois northwestward into Missouri as far as Jefferson City. Keyes 491 distinguished the Grand 

Tower limestone, 100 feet, and the Callaway limestone, 70 feet thick, the latter 

overlain by Kinderhook (Carboniferous) strata. The Grand Tower he referred to 

the Oriskany and Onondaga epochs, and the Calloway to the Hamilton epoch. 

The Onondaga fauna was also recognized by Weller 879 near Grand Tower, Ill. 

Buckley/ 06 in a recent paper, describes the Devonian of southeastern Missouri as 

composed of Clear Creek limestone (Oriskany age), at the base, overlain by Grand 

Tower limestone (Hamilton and Onondaga age), with the Sulphur Springs formation, composed of several members, at the top. Weller 882 and Ulrich a regard the 

Sulphur Springs formation as being of Mississippian age and a part of the Kinderhook. 

The relations of the Devonian strata of northeastern Missouri to those of Iowa, 

the significance of the unconformity between the Silurian and Carboniferous in 

central Missouri, and the correlation of the Devonian of southern sections are considered by Keyes 492 in a general paper. 

The Devonian of Illinois has been discussed by Weller 875• 

883 and Savage. 703b 

Weller's article in 1897 is a detailed study of the zones which may be recognized 

in the "Bake Oven" section, near Grand Tower, on Mississippi River. He distinguished seven conspicuous divisions comprising 26 faunal zones, from each of which 

he gives a list of fossils. He concludes: 875a 

It is believed that the facts here set forth satisfactorily demonstrate that the Devonian 

faunas in southern Illinois are not related to the Iowan Devonian faunas, as has sometimes been 

suggested, but are a western extension of the faunas of the New York province. ~t the "Bake 

Oven" section the fauna of the lowest beds is of an age corresponding to the lower portion of 

the Upper Helderberg period, while the uppermost faunas are of Hamilton age. The line of 

demarcation between the Upper Helderberg and Hamilton faunas can not be exactly drawn. 

a Personal communication. 
DEVONIAN. 279 

The discussion by Savage 703b is in part as follows: 

The rocks of Helderbergian age in Illinois correspond with the New Scotland formation of 

New York. They succeed the Clinton after an exceedingly long land interval, represented by 

all of the Silurian after the Clinton, and the Coeymans of the Lower Devonian. 

* * * * * * * * * The New Scotland formation in Union and Jackson counties has an aggregate thickness 

of more than 160 feet. The lower portion, for a thickness of 100 feet, consists of shaly limestone 

with interbedded bands of chert. * * * In the cut made by the Frisco Railroad Co. a 

short distance south and west of Tower Rock 10 species were collected. * * * 

The upper 58 feet of the New Scotland formation is composed of light-gray, heavy-bedded, 

coarsely crystalline limestone. * * * The beds furnished 17 species. 

The Clear Creek formation consists of light-gray to yellowish colored cherts that are usually 

in thin layers, but which in the lower part are sometimes 3 to 5 feet in thickness. * * * 

This formation rests, with erosional unconformity, upon the New Scotland beds at the 

south end of the Back Bone Ridge. It corresponds in age to the Camden cherts of western 

Tennessee. The beds represent deposits of the Upper Oriskany time, as is indicated by the 

interwedging of the upper chert layers with those of the basal portion of the succeeding Onondaga. The chert formation has a thickness, in Illinois, of about 327 feet. Fossils are somewhat rare in the lower portion, but in the middle and especially in the upper portion there is a 

rich fauna.a * * * 

The sedimentation of the Upper Oriskany time continued without a break into the Onondaga or Corniferous. The latter period was initiated by disturbances to the westward, in 

Ozarkia, which increased mechanical sedimentation in the Illinois area. These resulted for a 

time in the deposition, along the eastern shore of Ozarkia, of layers of sand containing Onondaga 

fossils alternating with the return of the Oriskanian limestone conditions. Eventually sand 

deposition prevailed and there was spread over the basin the basal sandstone of the Onondaga 

formation, containing [10 species]. 

Early in the Onondaga time an elevation in the southern portion of Union and in Alexander 

County put a stop to further deposition in these regions, while farther north, in Jackson County, 

sedimentation was uninterrupted. 

At the cut through the Back Bone and at the Bake Oven, a short distance north of Grand 

Tower, there is exposed a continuous section of the Onondaga formation showing a thickness 

of 115 feet. The beds consist largely of light-colored, regularly bedded, more or less crystalline 

limestone, which becomes arenaceous in the lower part. Fossils are abundant throughout the 

section.a * * * 

During the Onondaga and the succeeding Hamilton time the warm waters from the Gulf 

region, with their successive faunas, spread toward the northeast across Illinois and Indiana, 

passing around the north end of the Cincinnati axis, and mingled with those of the eastern 

embayment in western New York. Such water connections permitted continued migrations 

within this sea and account for the close correspondence between the various Middle Devonian 

faunas of southwestern Illinois and those of western Ontario and New York. 

Throughout Hamilton time the Kankakee barrier, or peninsula, extending from Ozarkia 

toward the northeast across Illinois, was largely effective in preventing the waters of the Interior 

or Mississippian sea from uniting with those of the northwestern or Dakotan basin toward the 

northwest. As a result of this separation the deposits and the faunas of Hamilton time, in 

Illinois, belong to two distinct provinces. The phase of the Hamilton in the vicinity of Rock 

Island and in Jersey and Calhoun counties belongs to the northwestern or Dakotan province; 

while that of southwest Illinois belongs to the New York province. 

The New York faunal phase of the Hamilton is well developed in the south part of Union 

County, in the N. -! sec. 34, T. 13 S., R. 2 W.; and farther north in the NE. ± sec. 34, T. 11 S., 

R. 2 vV. The formation is also represented in the upper beds near the north end of Back Bone 

Ridge, in Jackson County. 

a For list of fossils see the work cited.-B. W. 
280 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

At the first-mentioned exposure there is at the base of the Hamilton 28 feet of yellowishblue shale, which contains Leiorhynchus limitare. Both the character of the sediment and the 

fossils remind [one] decidedly of the Marcellus shale of New York. This shale rests unconformably (erosional) upon the basal sandstone member of the Onondaga. It is succeeded by a few 

feet of limestone, which in places is much leached and very fossiliferous, Athyris spiriferoides, 

Delthyris sculptilis, Rhipidomella penelope, Spirifer granulosus, and Stropheodonta concava being 

very common. At points farther north the lower beds of the Hamilton consist of dark-colored 

impure limestone which succeeds the Onondaga without any apparent break. The characteristic fossils of these layers are Microcyclus discus, Athyris vittata, Eunella attenuata, Spirijer 

fornacula, Conocardium cuneus, and Onychodus sigmoides. 

The middle portion of the Hamilton limestone is dark C<?lored and evenly bedded and 

contains Ambocmlia umbonata, Chonetes yandellanus, C. pusillus, Cran<£na romingeri, Parazyga 

hirsuta, Pholidops oblata, and Spirijer pennatus. Above this horizon occurs about 25 feet of 

yellowish-brown impure siliceous limestone with few fossils. Near the top of the formation 

eome in a few feet of hard gray limestone containing Chonetes coronatus, Rhipidomella vanuxemi, 

Spirifer audaculus, S. pennatus, Tropidoleptus carinatus, and Vitulina pu_stulosa. 

During Upper Devonian time the Mississippian sea continued to expand, spreading the 

materials of this formation more widely than the preeeding. In the NE. t sec. 34, T. 11 S., 

R. 2 W., the lower deposits of the Upper Devonian are conformable upon the Hamilton. There 

is here exposed a thickness of 33 feet oft yellowish-brown (black where unweathered) siliceous 

shale or shaly limestone, eherty near the top, and marked by Leiorhynchus globuliformis, L. 

mesacostalis, Reticularia lxvis, and Spirifer pennatus. At other points the upper eherty phase 

is succeeded by 50 or more feet of greenish to black, almost barren shales. These siliceous 

and dark-colored shales are probably the equivalent of the "calieo rock," a mottled and leached 

silieeous shale, present farther south in Union and Alexander counties. They doubtless correspond with the Chattanooga black sl1ale, Ohio black shale, New Albany blaek shale, and the 

Lower Portage beds of other States. 

Sys-1 tern. 

~ 

Oeneralized section of the pre- Mississippian strata in southwestern Illinois. 

Correlations. I ,::.:nof::,~e 

New Albany black 

s h a 1 e=Chattanooga black shale 

=Ohio black\ 

shale=Lower 1 

Portage, 86 feet. 

NE. t sec. 34, T. 11 

S., R. 2 W., and 

SE. t sec. 1, T. 13 

s., R. 2 w. 

Descriptions of horizons. 

------------------

Greenish-blue shale, fossils almost none ............ . Black shale with few fossils, but carrying numerous v:ry small balls of iron pyrite froq~. t to t inch in 

dmmeter ....................................... . Brown to black, siliceous shale or shaly limestone 

with Leiorhynchus globuliformis and Reticularia 

ll£vis ...................................... ..... . 

Light-gray siliceous limestone, in part oolitic, characterized by Chonetes coronatus, Cranl£na romingeri, Spirifer pennatus, S. audaculus, Tropidoleptus 

Feet. 

29 

21 

carinatus, and Vitulina pustulosa................ 7 

NE.l sec. 34, T. 11 1 Yellowish-brown siliceous or shaly limestone with 

'2 Hamilton, 70 feet. 

~ 

S., R. 2W., Union few fossils....................................... 25 

County. Section , In the north are dark-colored, fine-grained limestones 

c; 

~ 

..8 

~ ~ 

C/ 

,...., 

~ 

Marcellus, 28 feet. 

at Back Bone near \ with Microcyclus discus, Chonetes yandellanus, 

Grand Tower. 1 Eunella attenuata, Parazyga hirsuta, Spirifer for- . nacula, and S. pennatus. In the south are gray or leached limestones with Athyris spiriferoides, Delthyris sculptilis, Spirifer granulosus, Rhipidomella 

penelope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 

N. t sec. 34, T. 13 , Ra.ther so!t sha~e weatheri~g. to a yellowish-brown 

8 R 2 W U . I color, with Lewrhynchus lumtare . ............... . c"' t · mon This horizon is not present at the north, in Jackson oun Y· County. 

28 
Sys- ! 

tern. 

DEVONIAL~. 281 

Generalized section of the pre-Mississippian strata in southwestern Illinois-Continued. 

Correlations. 

Onondaga, U:>6i feet. 

Upper OriskanyClear Creek chert, 

Camden chert, 

237 feet. 

I Location of sections. 

I 

Back Bone, Jack- son County. 

Bake Oven, Jack- son County. 

:NW. t sec. 26, T. 

12 S., R. 2 W., 

also S W. t sec. 26, 

T.13 S., R 2 W., 

Union County. 

Schaffer's branch, 

2 miles west of 

Jonesboro; NW. t sec. 26, T. 12 S., 

R 2 W., Union 

County. 

NW. l sec. 10, T. 12 

S.,R2W.;NE.t 

sec. 12, T. 12 S., 

R 3 W., Union 

County. NE. t sec. 36, T. 14 S., 

R 2 W., Alexander County. 

-------------------

DescriptionH of horizons. 

The Onondaga is well developed in Jackson County, 

where it passes without lt break into the Hamilton. 

In the southern part of Union County there is a break and the Onondaga is represented only by 

the basal sandstone. 

Heavy layers of very hard gray, coarsely crystalline 

limestone, containing corals, Chonetes konickianus, 

Pholidostrophia iowensis, Productella spinulicosta, 

and Stropheodonta concava. Strophalosia truncata 

Feet. 

is abundant in the lower half, while Productella 

spinulicosta is common in the upper part.......... 26 

Layer of dark-colored limestone largely composed of 

Chonetes konickianus var.... . . . . . . . . . . . . . . . . . . . . . 3j 

Thin-bedded hard gray limestone, layers 2 to 10 

inches thick. Fossils rare: Chonetes konickianus var. present in the upper part and C. pusillus and 

Stropheodonta concava in the lower...... . . . . . . . . . . 15 

Hard gray impure limestone with few fossils......... 21 

Dark-gray impure limestone with thin chert bands near the top. Fossils numerous, Nucleocrinus 

11erneuili, Rhynchonella gainesi, l>feristella barrisi, 

Spirifer acuminatus, Stropheodonta patersoni, etc... 8l 

Dark-gray impure fine-gmined limestone. Chonetes 

mucronatus abundant in a zone near the middle. 

Other fossils are Rhipidomella vanuxemi, Spirifer 

grieri, Stropheodonta patersoni, S. perplana, and 

Phacops cristata. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 

Heavy layers of-light-gray subcrystalline limestone. 

Fossils abundant. Coscinium cribriformis, Centronella glansjagea, Spirifer duodenarius, S. macrothyris, 

and Odontocephalus mqeria present throughout..... 38 

Alternating layers of light-gray arenaceous subcrystalline limestone and coarse-grained sandstone, 

containing Centronella glansfagea, Meristella near lentiformis, Rhipidomella musculosa, Spirifer duodenarius and S. macrothyris....................... 15j 

Bed of more or less iron-stained sandstone, in places 

soft and friable, at other points cemented by a deposit of iron or silica, containing Michelinia 

stylopora, Aulacophyllum sp., Centronella glansfagea, Spirifer duodenarius, S. macrothyris and 

Odontocephalus arenarius ......................... . 

Bed of light-gray chert in layers 3 to 9 inches thick. 

Amphigenia curta, Chonostrophia reversa, Eodevonaria melonica, Schuchertella pandora, and Spirifer 

worthenanus abundant ...................... _ . _ . _ . Reddish-brown friable sandstone with Michelinia 

stylopora, Zaphrentis sp., Amphigenia curta, and 

Sp1:rijer duodenarius .......... _. _ ........... _ .... . Layers of light chert, 4 to 8 inches thick. Anoplia 

nucleata, Chonostrophia reversa, Eodevonaria melonica, Schuchertella pandora, and Spirifer worth- enanus . ......................... _. _. _ ......... _. _. Reddish-brown friable sandstone ......... _._ ...... . 

Bed of light-colored chert layers, in places alternating 

with impure siliceous limestone and at other points 

composed wholly of chert bands. Fossils most 

abundant in the upper part. Amphigenia curta, 

Anoplotheca .flabellites, Eatonia peculiaris, Eodevonaria melonica, Chonostrophia reversa, 'Schuchertella 

pandora, Spirifer worthenanus, and S. · hemicyclus common in the upper part ...................... . In the southern part of Union County the lower chert 

layers are massive and contain but few fossils. In 

the pit worked by the M. & 0. Railroad, 1~ miles 

north of Tamms, in Alexander County, may be seen an exposure of more than 100 feet in which 

few fossils were found. 

18 

2' 6 

225 

----------·-----
282 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA .. 

Generalized section of the pre-Mississippian strata in southwestern Illinois-Continued. 

I 

Sys- I Correlations. 

tern. 1 

Location of sections._! Descriptions of horizons. 

! - . -T~---~- ---- ~---------

__ ! ________ ~-~----- ·--~~-A short break in sedimenta--t~io~n~-----------

Xew Scotland, 

about 158 feet. 

8outh end of Back 

Bone, Grand 

Tower, Jackson 

County and Bald 

l'tock, SE. t sec. 23, T. II S., R. 

3 W., Jackson 

County. 

Grand Tower Rock, 

and Frisco Railroad cut a few 

rods farther west 

in Missouri. 

Heavy-bedded, light-colored, coarsely crystalline 

limestone with Eatonia singularis, Spirifer macro- pleura, S. perlamellosus, Stropheodonta beckii, and 

Feet. 

Strophonella punctulifera, about__ .. ____ .. __ .______ 58 

Bed of impure shaly limestone with bands and 

nodules of chert in the upper portion. Dalmanella 

subcarinata, .Meristella l~£vis, S pirifer cyclopterus, 

S. perlamellosus and Strophonella punctulifera, 

about ......... _ ......................... _. _____ . 100 

This horizon appears to belong immediately below 

the one above. It is doubtless present at Balci 

Rock and in the river bluff farther south, but the 

fossils were not fimnd at the latter points. 

A long break in sedimentation. 

---·~-------1--------~1~----------------------

2 miles northeast of 

Clinton- Dayton, I Gale, NW. l sec. 

Ohio Clinton, In- I 27, T. 14 S., R. 3 

terior or western W., and l mile south and southClinton, 75 feet. east of Gale, Alexander County. 

Pink mottled Hmestone in lavers 10 to 45 inches 

thick, containing many sma1l immature brachiopods, with which occur Plectambonites transversalis, 

Rafinesquina mesacosta, and Spirifer near sulcata .. _ 23 

Layers of gray to drab-colored limestone, 2 to 6 inches 

thick, alternating with thin bands of chert and 

characterized by such typical Clinton fossils as Stricklandinia triplesiana and Triplecia ortoni. _. _.. 6 

Bed of tough gray limestone in lavers 3 to 8 inches 

thick, which are imperfectly separated by 2 to 4 

inch partings of chert. Fossils rare. _______ .. _. _. _ 0--46 

This horizon is wanting at some points in this area. 

J-K 11~12. GREAT BASIN, NEVADA AND UTAH. 

In the Eureka section, Nevada, the Lone Mountain limestone (Ordovician) 

passes by imperceptible gradations upward into the Nevada limestone, which is 

followed by the White Pine shale, both assigned to the Devonian by Hague and 

measuring about 8,000 feet. Hague 391b d~scribes the relations as follows: 

The Lone Mountain and Nevada limestones taken together present an immense thickness 

of beds, lying between the Eureka quartzite and the White Pine shale. Together they measure 

about 7,800 feet in their broadest development. The division into Silurian and Devonian is 

based mainly upon paleontological grounds. The transition in sedimentation from characteristic Silurian to unmistakable Devonian is so imperceptible that a boundary between them is 

impossible to establish, and, as is usually the case where the beds form a continuous, conformable limestone series, a line of separation based upon faunal changes must always remain more 

or less arbitrary. Lithologically, in their broader features, the Silurian and Devonian limestones are quite distinct; it is only in the intermediate beds that no line can be drawn. The 

light-gray and white siliceous beds that form the mass of the Lone Mountain present a wide 

vertical range, and in these beds are occasionally seen obscure impressions of Niagara corals, 

and in other localities, in similar rocks not much higher up in the series, occur Atrypa reticularis 

and other forms foreshadowing the Devonian. It is known that the characteristic Lone Mountain beds carrying Halysites catenulatus extend for nearly 1,500 feet above the Eureka quartzite, and that beds easily identified by their organic remains bring the Devonian down to about 

6,000 feet below the summit of the great limestone belt lying between the Eureka quartzite 

and the White Pine shale. Halysites and Atrypa reticularis were never found associated 
DEVONIAN. 283 

together, although it can not be definitely stated that the former fossil does not appear as low 

down in the limestone as the highest occurrences of the characteristic coral. 

* * * * * * * * * 

Conformably overlying the Nevada limestone occurs a heavy body of black shale, which 

has been designated as above, it having been first recognized as a distinct horizon in the White 

Pine mining district to the southeast of Eureka. It occupies a clearly defined stratigraphic 

position 'vith a marked change of sedimentation and a fauna distinct from both the underlying 

and overlying horizons. 

* * * * * * * * * 

Impressions of plants, which are exceedingly rare in Paleozoic rocks of the Great Basin, 

are very abundant and form a distinctive feature of this epoch, notwithstanding that everything \vhich has been collected has been of a fragmentary nature. The most promising specimens for identification were submitted to Sir ""~illiam Dawson, who, in his report, called attention to the poor state of preservation of the plants. Under date of Montreal, June 11, 1889, 

he writes: 

"One slab contains a small ribbed stem referable to Goeppert's Anarthrocanna, a doubtful 

Calamitean plant. The specimen is not unlike those found at Perry, in Maine, and Bay de 

Chaleur. On the large slab is also a slender branch stem which I suppose may be the stipe of 

a fern, and from its character and angle of ramification probably belongs to the genus Aneimites, 

but no trace of tho pinnre can be seen. The evidence, so far as it goes, would indicate the 

Upper Devonian (or Erian, as I prefer to call it), rather than the Middle Devonian or the Lower 

Carboniferous." 

It will be seen that this determination as to the ago of the plants is quite in accord with 

the geological position of the beds above the Nevada limestone of the Devonian and directly 

below the Diamond Peak quartzite of the Carboniferous. 

Girty 3630 in 1905 tentatively placed the -White Pine shale in the Carboniferous 

and correlated it with the Caney shale of Arkansas. He says: 

In the White Pine district of Nevada the beds called "Lower Carboniferous" by ~1r. Walcott, which are suggested to be of Pottsville age, are underlain by a black shale-the White 

Pine shale-which he assigned to the "upper Devonian." I have long been of opinion, however, 

that the age of this bod is not Devonian, but Carboniferous. The Wnite Pine fauna, however, 

is not without forms suggestive of the Devonian, to which period it was also tentatively assigned 

by l\Ieck. One of the most striking of these is a Leiorhynchus resembling L. quadricostatum. 

Productus hirsutiformis and a Posidonomya (Posidoniella ?) also lend it a Devonian aspect'. A 

Leiorhynchus like L. quadricostatum, a Productus like P. hirsutiformis, similar Goniatites, and 

similar Posidoniellas, are found near the base of the Caney shale in Indian Territory, and in 

the Spring Creek limestone and Fayetteville shale of Arkansas. These facts, together with a 

similarity in lithologic character and an identity in stratigraphic position, in point of which 

each occurrence is immediately beneath beds supposed to represent about the same horizon, 

while not sufficient to demonstrate stratigraphic equivalence, for which a thorough comparison 

of the entire faunas would be necessary, lend a strong color of probability to it. 

Eastward from Nevada the Devonian thins notably. It was supposed to be 

represented in the Wasatch section by the Ogden quartzite of King, 505a but the 

formation has since been determined to be the Middle Cambrian quartzite repeated 

by an overthrust. Blackwelder 84e says: 

Kindle a has recently shown that the Jefferson limestone of Montana, with a sufficient 

Devonian fauna, extends southward into the mountains of Utah, and he has traced it along 

the east side of Cache Valley, in the Bear River Range. He has also identified in the same 

locality a limestone containing Silurian fossils conformable beneath the Jefferson formation. 

a Kindle, E. M., Bull. Am. Paleontology No. 20, Ithaca, N.Y., 1908. 
284 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

It was to be expected that the same formations would soon be found also on the west side of 

Cache Valley, in the Wasatch Range proper. As exposed on the crest of the range, there is, 

between the Ordovician quartzite and the identifiable part of the Mississippian limestone, a 

succession of dark limestones, with some ash-gray brittle dolomites having a thickness of 

1,000 to 1,500 feet. In the lowest beds there are corals such as Halysites and Favosites. At a 

slightly higher horizon there are abundant shells, which Kindle thinks are the same as his 

Pentamerus fauna of the Bear River Range. All the specimens, however, are poorly preserved, 

and show best upon the weathered surfaces. Between the Silurian horizon and the fossiliferous 

Mississippian there is a thick, dark limestone which corresponds satisfactorily with Kindle's 

Devonian Jefferson formation east of Cache Valley. Further search may be expected to 

reveal the Jefferson fauna in these beds. 

Kindle 498b, 499b examined the sections in several canyons south of Logan Canyon, in the northern part of the vVasatch Mountains. He distinguishes 1,000 to 

1,200 feet of dark magnesian limestones as Devonian, the equivalent of the Jefferson 

limestone of Montana. The formation lies between Silurian and Mississippian 

limestones. (See p. 320.) 

In the Uinta Range the Devonian is not present, the Ordovician quartzite 

being immediately overlain by limestones of lower Mississippian age. 

In the Grand Canyon section, Arizona, a limestone 94 feet thick is classed as 

Devonian by Walcott. 852 It rests on Cambrian rocks, as does the Ouray limestone in some areas in Colorado, and is overlain by the Redwalllimestone (Carboniferous), 962 feet thick. In Gilbert's original account 350 a of the Redwall he says: 

"The base of the system is arbitrarily assumed at the first marked lithological 

change, and it is not impossible that it has been placed so low as to include Devonian, or even Upper Silurian, if those formations are represented in the series." 

B. S. Butler a has recently found Devonian underlying Mississippian limestone 

in the Star Range, Beaver County, Utah. 

J-K 12-13. WYOMING AND COLORADO. 

In western Wyoming the Devonian is represented by the Jefferson limestone. 

It is not present in the Bighorn Range, according to Darton, and does not occur 

near Rawlins, according to Kindle. Blackwelder says that it probably occurs 

in the Teton and Gros Ventre mountains and perhaps in the northwestern part 

of the Wind River Range. 

In southwestern Colorado the Devonian is represented by the Elbert formation 

and the lower part of the Ouray limestone. The Elbert consists of calcareous 

shales, thin limestones, and local quartzite beds, characterized in many places 

where shaly by casts of salt crystals and carrying at several horizons fish remains 

of Upper Devonian age (Bothriolepis and Holoptychius). It usually rests unconformably upon the Cambrian .(Ignacio quartzite). It is conformable to the overlying Ouray limestone, the division between the two being marked by a band of red 

shale, the top of the Elbert. The Ouray limestone is in greater part dense and compact, yellowish, somewhat sandy in the lower layers, and in places coarsely crystalline in the upper ledge. It is 100 to 250 feet thick. The lower part contains a 

Devonian fauna and the upper part a Mississippian (lower Carboniferous) fauna. 

a Personal communication. 
DEVONIA:\'". 285 

No line of division can be traced between the two, however, and therefore all the 

beds are included in one formation. 

Girty 194 states: 

In general the Devonian fauna of the Ouray belongs to upper Devonian time. It is but 

distantly related to the Devonian faunas of New York, and its relation to those of the Mississippi 

Valley, or even to other known western Devonian faunas, is not close. It shows many points 

of approximation to the Athabascan fauna described by Whiteaves and is somewhat strikingly 

similar to the Devonian of Russia. 

J-K 17-18. SOUTHEASTERN PENNSYLVANIA, MARYLAND, AND VIRGINIA. 

Until recently the Onondaga has been supposed to be absent from the Allegheny 

region south of northeastern Pennsylvania. In regard to the occurrence of the 

Onondaga Kindle a says: 

This fauna, in a slightly modified form, extends southward from "New York through the 

Allegheny region as far as the northern boundary of Tennessee. The Onondaga fauna occurs 

throughout this region in the lower part of what has been called the Marcellus shale i.n the 

Pennsylvania reports, the Romney shale in Maryland and northern Virginia, and the base of 

the Chattanooga shale in southwestern Virginia. The beds holding this fauna in the Allegheny 

region represent an argillaceous facies of the Onondaga. They are chiefly drab or olive-green 

shales with more or less argillaceous limestone interbedded. This set of beds is separated from 

the Hamilton above by fissile black shales differing in no important features from the Marcellus 

shale of New York. 

Swartz 805 has identified the Portage and Chemung in western Maryland. He 

describes local sections, gives extended lists of faunas, and concludes: 

It is very difficult to determine [the Portage-Chemung boundary] when the brachiopod 

facies of the Portage immediately underlies the Chemung. Of the New York section Clarke 

remarks: "It is extraordinarily difficult to fix on ·a division plane between the Ithaca and the 

overlying Chemung faunas." If this be true in New York, it must be still more true when an 

attempt is made to correlate that section with those of other States, and the results attained 

must be open to revision as fuller investigations give increased data. Nevertheless, it seems 

reasonably probable from the preceding studies that the horizon in question is to be placed 

between the strata bearing the Spirifer disjunctus and Spirifer mesacostalis faunas, giving the 

following succession: 

Chemung, Spirifer disjunctus fauna. 

{

Spirifer mesacostalis fauna. 

Portage Spirifer pennal'us var. posterus fauna. 

Naples fauna. 

Genesee, Black shales with Buchiola fauna. 

Lithologically the horizon is not well defined, the conditions varying at different localities. 

In general the Portage is characterized by 'lmooth fissile shales and interbedded sandstones and 

the Chemung by a larger percentage of sandstones, while its shales are softer and break with 

a hackly fracture. The transition from Portage to Chemung is, however, not sh\lrply defined 

by any lithological features. 

Certain facts seem to harmonize with those of New York. 

1. The general succession of forms seems to be that of New York. At the base occurs 

the Genesee, thinning eastward, followed by the Naples fauna of the Portage. Above the 

latter is found Spirifer pennatus var. posterus, succeeded by Spirifer mesacostalis, and finally by 

Spirifer disjunctus. 

• a Comment on manuscript. 
286 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

2. There is a greater development of the Naples fauna in the west and of the Ithaca fauna 

in the east. 

3. The shore line was probably eastward, as indicated by the fact that there is a marked 

development of conglomerates eastward, as at :Millstone. These diminish toward the west, 

where the lower Jennings is largely composed of argillaceous shales, as at Allegany Grove. 

The thinning of these formations southward through the Virginias may be 

traced in general stratigraphic terms in folios of the Geologic Atlas of the United 

States by Darton 226' 228' 229' 

231 and Campbell; 121' 123' 

124' 125 also in other papers by 

Darton, 221 Campbell/22 and Prosser.650 

Devonian formations in Piedmont, Franklin, Staunton, and 11fonterey quadrangles. 

I 

Thickness (feet). a I 

! System. Formation. 

Staunton. I ::\fonterev.l 

General character. 

Piedmont. Franklin. 

----~-

I . 

' 

~~ I 

e·a 

~P.; ·~-~ Pocono sandstone. 30-80 85-700 700 70-90 Conglomerate and sandstone. 8.~ 

~-~ ue 

Hampshire forma- .More or less thinlv bedded sandstone 

2,000-2,300 1,600-2,200 ·1,000-1,400 1,500-1,800 and shady shaJe, generally red, tion. with gray and greenish-gray beds. 

-· --·---~- ·----

1 Jennings formation. 3,300 2,100-3,800 2,800-3,400 3,000-3,800 Gray to buff sandstone interbedded 

>=i with gray, olive, and buff shale. 

·;:: "

0 

I Shale, black and fissile below, with ;;. C) 

H Romney shale. 11,100-1,300 1,100-1,300 600-1,000 1,000-1,300 thin limestone layer, lighter colored and more sandy above. 

Montcmy e•ndetnnc 1

1 

21&-300 I 

Uncon- Unconformity. formity. 

200-300 0-300 I 50-200 Calcareous sandstone, weathering to 

brown porous sandstone . 

----- . ------

Silurian.~ Lewistown limestone. I [In part equiyalent to Helderbergian (Devonian). See Chapter Y, p. 239.] 

a The measurements range south through the Piedmont, Franklin, and Staunton quadrangles from latitude 39° 

301 to 38° and west from the Staunton to the )/[onterey, longitude 79°-80°, in West Virginia and Virginia. 

Two quadrangles which lie southwest of the Monterey quadrangle, between 80° 

and 81° west and 37° 30' and 38° north, have not been surveyed. Next southwest 

come the Pocahontas and Tazewell quadrangles (81 °-82° west, 37°-37° 30' north), 

which have been mapped by Campbell. 123 •

124 In the interval the distinction between 

the Jennings and Hampshire is lost, as shown in the following section from the Pocahontas and Tazewell folios: 
DEVONIAN. 287 

Devonian formations in Pocahontas and Tazewell quadrangles. 

-- ----~-----,~------~------------------------

1 Thickness (feet). 

I 

~;oca- I Taze--

l hontas. • well. 

System. Formation. 

----~ ------------- ---

Carbon- p · d ifcrous. nee san stone. 

----------------- -~--! ---

\ Kimberlingshalc. [Ap-1· r· 

proximate equivalent 3,000- 2,000?~ 

of Jennings and I 3,250 , 3,000 

_

1

, Hampshire.] I . I 

General character. 

(Transition; no distinct boundary.) 

Green, sandy shale and thin sandstone c.ontaining one or more beds of quartz conglomerate ncar the top. 

(Transition; no distinct boundary.) 

! -;onmey shale. : ~0~600 1300~500 Black carbonaceous shale. 

I 1---------------

1 

I Giles formation (Oris- -- --- kany and Lower Hel- 30--200 100--200 

Coarse yellow sandstone. 

Cherty limestone. 

Coarse reddish sandstone. 

Blue limestone. derberg). 

----------··-· ---. 

I 

formation 

I 

Rockwood 

, (Clinton). 

Kindle's collections from southwestern Virginia have shown that the typical 

Chemung fauna extends southwestward as far as Bland County and that the greater 

part of the Kimberling shale is the equivalent of the Chemung of New Y ork.938a 

The portions of the Pocahontas and Tazewell quadrangles in which the preceding 

sections were observed lie in southwestern Virginia. In the extreme southwestern 

part of the State, 30 miles beyond them, is the Estillville quadrangle, which presents 

the following section north of Clinch River according to Campbell: 121 

Devonian formations in Estill ville quadrangle. 

·-

System. Formation. Thickness General character. (feet). 

--------------~----- ----------· -------

Carboniferous. Newman limestone. 700-930 ;pure blue limestone in the lower part; cherty towa 

the base. 

rd 

- ----- ·---

Grainger shale. 420--500 Calcareous sandstone above sandy shale, merging in 

black shale below. 

to 

Devonian. 

Chattanooga black shale. 530--1,000 Chiefly black carbonaceous shale; with ash-color 

sandy member in the middle. 

ed 

--~-------- --------- -. -· ----- -----

Silurian. Hancock limestone. ["] 180~275 Blue fossiliferous limestone, very sandy at the top an bottom. 

d 

- ---~---

a According to Kindle (personal communication) the Hancock limestone is of Silurian age in lower part and of 

Devonian age in upper part.-B. W. 
288 INDEX TO THE STRATIGRAPHY OF NORTH kMERICA. 

The change of names from the Tazewell to the Estillville quadrangle indicates 

the uncertainty attending the selection of formational and also of systemic boundaries in the two sections. The relations of the Kimberling shale to the Grainger 

shale and of the Romney shale to the Chattanooga shale have not been traced across 

an unsurveyed gap of a fe~ miles. The Grainger may include part of the basal 

Mississippian. 

The Grainger shale has been mapped by Keith through the Morristown and 

Maynardville quadrangles, Tennessee, to the vicinity of Knoxville (longitude 84° 

west, latitude 36° north), and it is accompanied by the Chattanooga shale, which 

extends beyond to Georgia and Alabama. 

Along the base of the Cumberland escarpment across Tennessee, from the Briceville through the Kingston and Chattanooga quadrangles, into Georgia, the Devonian 

is represented only by the Chattanooga shale, which ranges in thickness from 80 feet 

in the northeast to as little as 10 feet in the south. In its occurrences in Georgia 

and Alabama the Chattanooga shale is remarkable for the persistency with which 

it retains its character, although everywhere very thin. 

In the Coosa Valley of Georgia and Alabama the Frog Mountain sandstone (of 

Oriskany age) lies unconformably upon Ordovician rocks. Hayes 418 described the 

occurrence as follows: 

There are between Indian and Weisner mountains several small areas occupied by a formation which comes in contact with all the older formations thus far described. It consists of 

coarse ferruginous sandstone, in some places white, resembling quartzite, and in others yellow 

or gray and weathering to incoherent beds of sand. Beneath this sandstone and usually deeply 

covered by its debris are shales, also variable in composition and appearance. No satisfactory 

measurement has been made of their thickness, but this is probably as variable as their physical 

appearance. 

Schuchert ill! determined the following Oriskany forms from this sandstone: 

Orthis (Rhipidomella) musculosa Hall. 

Stropheodonta magnifica Hall. 

Anoplotheca fimbriata Hall. 

Spirifer tribulis Hall. 

Meristella cf. walcotti Hall and Clarke. 

AmboctElia umbonata Conrad. 

K 10. KLAMATH MOUNTAINS, NORTHERN CALIFORNIA. 

Among the Paleozoic strata of the northern Sierra the Devonian is recognized 

by an Onondaga fauna. The fossils are corals, which in places form reefs, and the 

terrane itself consists of limestone, 50 to 70 feet or more thick, which is associated 

with schists and eruptive rocks. 283 

Diller has brought together the available information regarding the Devonian 

of northern California. He distinguishes the southwestern and northeastern belts, 

which may be recognized on the map. Concerning the former he says: 2760 "In the 

southwestern belt there is a line of Devonian limestone lentils (formerly doubtfully 

referred to Jura-Trias) which may be traced with many interruptions for over 100 

miles parallel with the South Fork of Trinity River." In the detailed descriptions 
DEVONIAN". 289 

of several localities, the intimate association of the limestone with more or less 

vesicular igneous rocks that break through it, inclose it, and form the greater mass 

of the material is repeatedly mentioned. The fossils from one locality (near White 

Rock) were determined by Schuchert as Upper Devonian, those obtained at six 

other localities as Middle Devonian. 

Concerning the northeastern belt Diller 276ct states: 

The northeastern belt of Devonian limestones and shales lies chiefly in the Sacramento 

drainage, extending northward into the Klamath and Rogue River region. The southern 

part, lying within the Redding quadrangle, and as far north as Gazelle, has already received 

much attention. The principal limestone bodies rich in fossils occur ncar Klamath and on 

Hazel Creek. Smaller masses outcrop near Horsctown and at a number of points 6, 8, and 

11 miles northeast of Redding, where they lio dose to the Carboniferous in line with a larger 

mass 2 miles northwest of Baird. 

One of the best sections of these rocks, but not including the whole Devonian series, may 

be obtained on Backbone Creek 3! miles north of Kennett, where nearly 900 feet of sediments 

are quite fully exposed. 

[Top.] Feet. 

l. Conglomerate; many quartz pebbles and numerous holes from dissolved limestone fragments, some of which contain foa~ils like those of the limestones below. Unconformable 

on 2. Possibly Carboniferous .................... _:_. ________ .. _________ . ______ .. ___ .. 30 

2. Shales, mostly dark, with some thin sandy beds .. ______ ..... _ ....... ___ ... _____ ... ___ ._. '140 

3. Limestone, rather massive, light colored; little chert but full of corals, etc. (locality 6242).. l(JO 

4. Thin-bedded sandstones and shales which are cherty and gray below. Near middle part 

is limestone lens 10 to 15 feet thick .... _._ ...... ______ .... _ .. __ ...................... __ 300 

5. Limestone, thin bedded and crowded with massive, branching, and cup corals (6244). 

Cherty nodules and bands in bluish limestone becoming whitish and without chert below 250 

6. Siliceous shales; 10 feet of banded chert at top, with sandy shales, black shale, and fine 

shaly sandstone, very thin bedded, resting on the igneous rocks below................. 75 

A large number of fossils were collected from the Devonian of the Redding quadrangle, 

and these may in large part be referred to the section given, although but few of the fossils 

were actually collected at the point where the section was measured. After enumerating a 

number of the species found at various localities, Mr. Schuchert concludes as follows!: 

"The section of locality 6242 given me by Mr. Diller, the thickness of which he estimates 

to be about 900 feet, has one general fauna indicative of the Middle Devonian. The general age 

has been known for some years, but the collections of 1902 have given us a definite section 

and also species that arc known to occur in other American localities. This is especially true 

of the fossils of the lower shale zone, which repeats the fauna of the Eureka and White Pine 

districts of Nevada and the Middle Devonian of Iowa. The species that are common to at 

least two of these regions are Schizophoria striatula, Stropheodonta canace, Gypidula lotis, Pugnax 

altus, Atrypa missouriensis, and Oyrtina missouriensis ~" 

Taking these species in connection with the corals of the limestones, as Heliolites porosa, 

Endophyllum or Spongophyllum, and Phillipsastrroa, one sees plainly that the California 

Middle Devonian belongs to the ''Euro-Asiatic province." This province extends east in 

North America as far as central Missouri, eastern Iowa, :Milwaukee, Wis., and Petosky, Mich. 

East of these places occur the Middle Devonian faunas of the "North American type." 

These Devonian strata are described as the Kennett formation, their stratigraphy, details of occurrence, and paleontology are presented, and their conformable 

relations to older volcanic rocks are stated in the Redding folio. 279 

4801P-12--19 
290 INDEX TO THE STRATIGHAPHY OF NORTH AMERICA. 

K 15. IOWA. 

The following section of the Devonian of Iowa was compiled by Chamberlin 134C from the Iowa Survey reports: 

Generalized section of the Devonian for Iowa. 

Formation. 

Lime Creek formation. _____________ - ____ _ 

State quarry beds. ______________________ _ 

Sweetland Creek shales.___________ _ _ __ _ 

Unconformity. 

Cedar Valley limestone __________________ _ 

Wapsipinicon formation (Independence, 

Fayette, Davenport). 

Thickness 

(feet). Characteristics. 

80 Dark-colored argillaceous shales, highly fossiliferoue, and 

locally calcareous. 

20-40 Light gray; good building stone. Fish teeth. 

20-40 Black and greenish; Upper Devonian fossils. 

250-300 Pure to argillaceous limestone and dolomite; sometimes 

massive, sometimes finely laminated, frequently brecciated. 

100-150 Carbonaceous shales with bands of impure concretionary 

limestone; brecciated limestone_ 

These strata represent Middle and Upper Devonian, a local unconformity or 

change in fauna distinguishing the two. The Middle Devonian beds overlap northward as they rise in the series and rest in part on Silurian, in part on Ordovician. 

Calvin 117 states with reference to strata in the extreme northern part of the State: 

The lowest beds seen in Howard County belong to a horizon far above what has been 

recognized as the base of the Devonian in the southern part of the area of its distribution. 

The beds which rest directly on the Maquoketa contain Stropheodonta demissa Conrad, Productella subalata Hall, Atrypa aspera Schlot., Spirifer pennatus Owen, and Oyrtina hamiltonensis 

Hall. The fauna indicates a horizon equivalent to that represented about the middle of the 

quarries at Independence, in Buchanan County. In this zone in Howard County, Productella 

is the most abundant and most characteristic fossil, and it is convenient to refer to the horizon 

as the Productella beds. This zone belongs to the Upper Davenport beds of Norton, below 

which, before reaching the base of the Devonian in Linn, Cedar, and Scott counties, there are 

divisions of the Wapsipinicon stage which have been described as Lower Davenport, Independence, Otis, and Coggan. 

With reference to the distinction of Devonian and Carboniferous Weller 877 

concludes: 

The succession of faunas exhibits a somewhat gradual transition from the earlier faunas 

with quite marked Devonian characters to the later ones which are typically Carboniferous 

in aspect. The Devonian element in the faunas is for the most part exhibited by the pelecypods, 

while the brachiopods are usually Carboniferous in aspect. This overlapping and intermingling 

of Devonian and Carboniferous faunal elements makes it impossible to draw a sharp line separating the Devonian and Carboniferous systems such as is recognized in the continental interior 

between the Ordovician and Silurian in the Medina formation, and between the Silurian and 

Devonian in the W aterlime formation. The Devonian-Carboniferous dividing line is more 

nearly analogous with the Cambro-Ordovician division. 

K 16. WISCONSIN. 

In the vicinity of Milwaukee the Devonian is represented by the Milwaukee 

formation (of Hamilton age). According to Alden, 11 as nearly as can be determined from partial exposures and drilled wells the order and maximum thickness 

of the members of the formation are as follows: 
DEVONIAN. 291 

Generalized section of the Devonian beds of Milwaukee, Wis. 

Feet. 

Black shale._______________________ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 15 

Soft bluish "soapy clay" or shale. _______ ... __ . ___ . _____________ . _____ ._------.-............. 80 

Bluish magnesian limestone, "cement rock"__________________________________________________ 12 

Bluish limestone and softer bluish "soapy clay" _________________________ ... -- ....... ____ ._.__ 31 

These beds, with the exception of the upper black shale, are highly fossiliferous, showing 

a great variety of invertebrate forms as well as plates and teeth of armor-plated fishes. 

* * * Beneath this group of beds is the brownish limestone provisionally referred to the 

Cayuga group [W aubakee formation, Silurian]. 

K 17. ONTARIO. 

In Ontario the Devonian formations, as determined by boring, are listed by 

Brummel 105 a as follows: 

Devonian: 

Portage and Chemung _______________________________________________ .... _ . _____ . _ . 

IIamilton, about .. ____________ ..... _. _ .. _ .. _ ... _ .. _ .. _ ............. _. _ ... _. _ .. ____ . 

Corniferous. ____________ .. _ .. __ .. : .......... _ .............. _ .. _ . _ .... _ ........ __ . _ . 

Oriskany ________ . _____ .. _ .............. _ .. _ . _ .. _ . _ ..... _ ..... _ .......... __ . _ . __ . __ 

Silurian: 

Lower Helderberg_ . __ . ____ .............. _ . _ . __ . __ . _ ........... _ . _ ......... _ . _ . __ . } 

Onondaga. _____ . ________ . __ ._._. __ ._ ........ : _ ....... _. __ .. __ .... _. _ .. _ .... ___ . __ _ 

Feet. 

25-200 

350 

160-300 

6-25 

300-1,000 

These formations, their distribution, and their relations to the New York 

equivalents as then understood were described in detail by Logan. 544P Concerning 

the Oriskany he states that it enters Canada at Waterloo, on the Niagara. 

In its lithological characters it does not seem to differ materially from the same rock in 

New York. The lower beds appear in several places to be composed of chert or hornstone, 

frequently containing large quantities of iron pyrites, and occasionally beautiful specimens of 

purple fluorspar. * * * Resting on these beds there is a sandstone, which is somewhat 

different in different localities. In the township of Dunn, near Haldimand, it is frequently 

made up of large angular pieces of hornstone; which, with the numerous large corallines and 

other fossils present, render it almost useless as a building stone. In the townships of Oneida 

and North Cayuga * * * there are large exposures of the rock. It is composed of fine 

grains of white quartz, in some parts so closely cemented as to assume the characters of a white 

compact quartzite. In other parts it is made up of coarser grains of quartz, some of them 

being an eighth of an inch in diameter and pretty well rounded. With these there are occasionally grains of feldspar. The rock in these cases, being sometimes slightly calcareous, disintegrates by exposure to the weather. The beds are massive and from 6 inches to 6 feet thick. 

* * * The sandstone in some parts very much resembles the white beds of the Potsdam 

formation; but it passes from white to light gray and, in some places, through yellowish to 

brown. * * * The greatest thickness of the mass may be about 25 feet; but though now 

and then attaining 10 feet, it seldom exceeds about 6, and it is frequently wanting between the 

Waterlime series and the overlying Corniferous formation. 

The rock abounds in organic remains. a 

Concerning the "Corniferous" Logan states: 

In western Cimada we find that many of the fossils of the Corniferous limestone pass up 

from the Oriskany sandstone; and the intermediate Onondaga limestone, with its encrinites, can 

no longer be recognized as a distinct formation. We therefore unite the two limestones under 

the name of the Corniferous formation. 

a For list of species see the work cited.-B. W. 
INDEX TO THE STIL\.TTGRAPHY OF NORTH AMERICA. 

The surface occupied by this formation in western Canada is probably between 6,000 and 

7,000 square miles. A great part of this however is deeply covered by drift, so that the exposures 

are comparatively few. * * * 

The generally small dip ,of the strata and the frequent occurrence of slight undulations 

render it very difficult to find the succession of the beds, or to determine with accuracy the 

whole thickness of the Corniferous formation. The groat extent occupied by it in western 

Canada, however, makes it probable that it must be much more considerable here than in New 

York. In the townships of Woodhouse and Townsend, where there arc frequent exposures, the 

breadth at right angles to the strike is upward of 10 miles. Tho fall of the surface, in that 

distance, is estimated at 140 feet; so that if the average slope does not exceed 30 feet in a mile, 

there would here be a thickness of about 160 feet of the Corniferous limestone. The strata 

which in Michigan are considered as the equivalents of this formation have, according to Prof. 

Winchell, a thickness of about 350 feet; so that it would appear that the thickness gradually 

augments to the westward. 

The formation enters Canada from New York, nearly opposite Buffalo, and is traceable in 

a narrow belt along the shore of Lake Erie, resting on the Oriskany sandstone, or, where this is 

wanting, on the vVaterlime series. * * * Some portions abound in chert, which forms 

beds of from 1 to 4 inches or exists in nodules like flints in the limestone. Many of the beds 

contain silicified organic remains. These in some localities, as in North Cayuga and at Port 

Colborne, are found weathered out ~nd loose, in groat abundance, at the surface of the ground. 

Some of the beds are little more than an aggregate of silicified organic remains, with so little 

calcareous matter that the whole mass coheres, after the carbonate of lime has been dissolved 

out. * * * 

To the west of the Grand River, in the counties of Haldimand and Norfolk, the Corniferous 

limestones are often seen resting on the Oriskany formation and forming small eminences, which 

present escarpments, with the sandstone at their base. These limestones are here of a drab 

color and abound in chert. * * * 

Higher in the series, along the same line of country, blue limestones, sometimes to the 

amount of 20 feet, with gray beds in less volume, are associated with cherty layers, and interstratified with bands of a drab-colored limestone. * * * 

The limestones of this formation are all more or less bituminous, and bitumen exists in 

many of them in a liquid form, as petroleum or rock oil, filling the cells of the corals and other 

fossils. The corals often prevail in distinct bands, some of which will be saturated with the oil 

while those above and below will have little or none. In working.l\h. Horn's quarry, which has 

already been mentioned, on tho thirteenth lot of the second range of Bertie, the oil is seen to 

impregnate particular beds, which are in great part made up of the remains of a species of 

Heliophyllum. These corals, in various attitudes, are arranged in bands varying in breadth 

from 3 to 6 inches; and in their open cells the petroleum is lodged. The intermediate parts of 

the rock, which contain no oil, are composed of a mass of broken organic remains, chiefly encrinites, wh{le in the coral-bearing beds these comminuted crinoids serve as a paste to fill up the 

interstices among the corals. 

Logan defines the stratigraphic limits of the Hamilton formation of Ontario as 

follows: 

In the western part of Canada we have not been able to distinguish either the Marcellus 

shales or the Tully limestones from the Hamilton group, and we shall therefore, in describing the 

rocks of that region, include under the name of the Hamilton formation all the strata between 

the Corniferous limestones and the Genesee shales. This formation occupies the lowest portion 

of the saddle-shaped depression noticed in tho previous chapter as crossing the peninsula from 

Lake Erie to Lake Huron and separating tho Corniferous formation into two areas. The space 

thus occupied is very much covered by drift and the contact between the Corniferous and 

Hamilton formations has not yet boon seen, so that it is not easy to assign their precise stratigraphical place to the exposures which arc mot with. 
DEVONIAK. 293 

The strata comprised in this interval are described as gray calcareous shale, 

gray limestone composed of remains of encrinites, and soft shales. There are also 

black shales which may indicate the passage from the Marcellus to the Hamilton. 

Logan cites several partial sections, and Brummel 105 gives well records which 

include the Hamilton. 

Under the name " Portage and Chemung group" Logan 544q cit("Jl the occurrence 

of black bituminous shales, which may represent the Genesee and which occupy a 

small area at Kettle Point, on Lake Huron. He says: 

Here, in a low cliff, on the west side of tho cape, is a section of between 12 and 14 feet of 

very fissile black bituminous shales, weathering to a leaden-gray, and often stained brown by 

oxide of iron. A yellow earthy coating of oxalate of iron is sometimes found in the surfaces of 

the shales, which also contain nodules and crystals of iron pyrites, besides peculiar spheroidal 

concretions, whose fancied resemblance to inverted kettles has probably given its name to the 

point. They vary in size from 3 inches to as many feet in diameter, and are sometimes nearly 

spherical and at others somewhat flattened, generally on the under side. Occasionally a smaller 

spheroidal mass is implanted on the top of a larger one. These concretions are readily broken 

and are then seen to be composed of brown crystalline carbonate of lime, which is confusedly 

aggregated in the center and sometimes contains blende. Arou.nd this arc arranged slender 

prismatic crystals, which extend from the nucleus to the circumference, the whole having a 

radiated columnar structure, which, not less than the terminations of the prisms at the surface 

of the spheroidal masses, gives them very much the aspect of fossil corals. 

On the east side of the point the upper beds of the section are concealed, but the lower ones 

come from beneath the bank at a little above the water's level and cover an area of several 

acres, the whole surface being studded with these spheroidal concretions, which remain when 

the softer shale around them has been partially worn away. 

This black shale is fossiliferous and contains a fucoid resembling a variety of the F'ucoides 

cauda-galli of Vanuxem, which is very abundant in the lower beds. Flattened stems of Calamites inornatus (Da"Wson), which are sometimes 7 or 8 feet long, and 3 inches wide, occur 

about the middle of the section and are occasionally converted into coal. Besides these, according to Dr. Dawson, there occurs here a stem which belongs to Sagenaria veltheimiana (Goeppert). 

An undetermined Lingula is found with these plants, together with numbers of what appear 

to be microscopic orbicular shells. 

The fauna of the Oriskany of Ontario has been carefully studied by Schuchert, 710 

and that of the Hamilton by Whiteaves. 915•

921 Shimer and Grabau 740 have published measurements of local sections at Thedford, Ontario, and lists of fossils from 

the several divisions, together with a discussion of correlation and faunal migration. 

K 17-18. PENNSYLVANIA AND NEW JERSEY. 

The Devonian formations of New York can be traced southward into Pennsylvania and New Jersey, as was shown by Williams 9

:

30 in 1884, by the work of the 

respective State surveys, and by recent studies of several observers. Some of these 

formations; however, notably the Tully limestone, are exceptionally limited and are 

not known to occur south or west of northeastern P·mnsylvania and northern New 

Jersey. The Ithaca fauna, which is lacking in western New York, extends across 

Pennsylvania in a belt that passes southeast of Altoona. The contemporaneous 

fauna of the Portage of western New York occurs at Altoona, the two faunas being 

inshore and offshore, as brought out by Williams and Kindle. 938 
294 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The section near Altoona, as determined by Butts, 112 is as follows: 

Section of Devonian rocks near Altoona, Pa. 

Formation. 

• Pocono sandstone (Carboniferous). 

Catskill formation ............. . 

Chemung formation ............ . 

Nunda (Portage) formation ..... 

Genesee shale ................. . 

Hamilton formation ............ } 

Marcellus shale ............... . 

Oriskany sandstone ....... ___ . __ 

Thickness 

(feet) . 

2,000 

2,500 

1,400 

Character. 

Red shale and red or brown sandstone, with some gray or green shale or sandstone. Unfossiliferous. 

Lower 1,400 feet gray or green sandy or clay shale; upper 1,000 feet 

large proportion chocolate shale and thin layers of chocolate sandstone; fossiliferous; conformable with Nunda. 

Base soft pale-brown clay shale, splitting easily into thin, smooth 

plates; above, change to greenish-gray sandy shale with some layers 

of hard bluish fine-grained sandstone. Fossiliferous. 

80 Black clay shale, very fissile, containing plentiful calcareous concre3,100 

20-50 

tions; conformable with both Nunda and Hamilton. 

{

Very dark green, olive-green, and gray shale and dark-green sandy, 

slightly micaceous shale; infrequent bands of fine-grained bluish 

sandstone. 

Thick-bedded, generally coarse-grained gray or buff siliceous rock. 

Kindle 495 comments in detail, with faunal lists, on the faunas of the Altoona 

se~tion. 

The Devonian formations in New Jersey present different characters in two 

districts, the Delaware Valley and Green Pond Mountain. Kiimmel 513c states: 

The Devonian formations of the upper Delaware Valley are of marine origin and are 

chiefly fossiliferous calcareous shales and limestones having a thickness of about 1,000 feet. 

Those of the Green Pond Mountain region are chiefly arenaceous shales, sandstones, and 

conglomerates, carrying comparatively few fossils and aggregating over 4,000 feet in thickness. 

The Helderbergian or lowermost Devonian faunas in New .Tersey are essentially the same 

as those in New York, and the same faunal zones arc recogni;~;ed. The fir:<Jt formation carrying 

these faunas is the Coeymans limestone. 

Coeymans limestone.-In the Nearpass section the Coeymans limestone has an estimated 

thickness of 40 feet, though only the lower beds arc exposed. It rests conformably upon the 

Manlius limestone, from which it differs lithologically in its coarser and more crystalline 

texture and lighter color. Frequently more or less chert is mingled with the limestnne. The 

Coeymans fauna is far more prolific than that of the Manlius and differs markedly in composition, the most characteristic species being Gypidula galeata. A coral bed carrying more or 

less completely silicified masses of Favosites hclderbergia: and a concentrically laminated 

stromatoporoid occurs in the base of the formation. 

Stormm:Zle sandstone.-In the southern half of the "\Yallpack Ridge in New Jersey, a thin 

sandy layer occurs at th~ top of the Coeymans limestone. It is in general an inconspicuous 

formation, owing to its thinness and heavy deposits of glacial drift. It becomes more conspicuous toward the south and according to vv11ite a it gradually replaces the overlying calcareous and shaly strata until it occupies the entire interval between the Coeymans limestone 

and the Oriskany sandstone. It has not been recognized in the N earpass section near Tristates 

nor at any point north of Hainesville, N.J. 

New Scotland beds.---The New Scotland bed;;;, which overlie the Coeymans limestone in 

the Nearpass section, consist of about 20 feet of a very hard cherty limestone followed by a 

series of calcareous shales, having an estimated thickness of 140 feet. Nowhere in the State is 

there exposed a continuous section of these beds as is the case with several of the lower formations. The fauna is a prolific one and is especially characterized by the 'abundant representation of the genus Spirifer. Its diiTerences from the Coeymans fauna are of such an essential 

a Second Geol. Survey Pennsylvania, Rept. G6, 1882, pp. 132, 133. 
DEVONIAN. 295 

character as to indicate a separate immigration from the exterior into this region. a As indicated 

above, south of Hainesville a thin sandy bed intervenes between the Coeymans limestone and 

the New Scotland beds and gradually replaces the latter. ·At Flatbrookville, where these strata 

cross the Delaware into Pennsylvania, the lower cherty limestone member of the New Scotland 

beds has disappeared and the Stormville sandstone contains a fauna characterized by Spirifer 

macropleurus. 

Becraft limestone.-A hard gray cherty limestone overlies the shaly layers of the New 

Scotland beds, forming a resistant layer which outcrops frequently along Wallpack Ridge. 

Its entire thickness has never been observed, but it is estimated to be about 20 feet. Its fauna 

is closely allied to that of the New Scotland beds, a few new forms appearing and a few old ones 

disappearing. There is also some difference in the proportionate number of individuals of 

some species, notably of Leptcena rhomboidalis, which becomes especially abundant. The 

bed is correlated with the Becraft limestone of New York. 

Kingston or Port Ewen beds.-A series of strata, nowhere exposed, occupies the interval 

between the Becraft limestone and the base of the Oriskany. They are probably shaly beds 

which easily disintegrate and thus become covered with debris. Their thickness is roughly 

estimated as 80 feet. The only basis for their correlation is their position, which corresponds 

to that of the Port Ewen (Kingston) beds of New York. In Pennsylvania, the same beds have 

been called the Stormville shales by White.b 

Oriskany formation.-A series of strata, aggregating about 170 feet in thickness, succeed 

the Port Ewen beds and are referred to the Oriskany. They are for the most part siliceous 

limestones, but the summit of the formation along the southern half of the Wallpack Ridge 

becomes a sandstone. The arenaceous facies is said to become more marked to the southwest 

in Pennsylvania and to embrace lower and lower beds until all the strata to the top of the 

Coeymans limestone are sandstones. The fauna of the Oriskany beds in New Jersey comprises 

three well-defined faunal zones, the lowest characterized by Dalmanites dentatus, the second by 

Orbiculoidea jervensis, and the third by the great abundance of Spir1fer murchisoni. 

In the N earpass section the beds bearing the Dalmanites dentatus fauna are about 30 feet 

thick and form the crest of a high ridge which is the southern extension of the "trilobite ridge "c 

east of Tristates. There is a mingling of Helderbergian and Oriskanian forms in this fauna, 

and there has been some difference of opinion as to whether these beds should be placed in the 

Port Ewen or Oriskany, but recent workers d unite in referring them to the Oriskany. 

Esopus grit.-The Esopus grit which overlies the sandstones and siliceous limestones of 

the Oriskany forms the crest o£ vYallpack Ridge for the greater part of its extent in the State. 

It is a nearly black gritty rock with well-developed cleavage, which obscures the bedding planes. 

The fucoid "cauda galli" markings can frequently be recognized on the bedding planes when 

the latter can be distinguished. Apart from these markings fossils are very rare. The average 

thickness of the formation in New Jersey is estimated to be 375 feet. 

Onondaga l1:mestone.-The Onondaga limestone overlies the Esopus grit along the northwestern slope of \Yallpack Ridge. Toward its base the formation is somewhat shaly and there 

is apparently a rather gradual transition from the grit to the limestone. The latter is hard, 

cherty, and regularly bedded in layers ranging from 3 inches to 1 foot in thickness. The beds 

are assigned to the Onondaga on the basis of their position and lithology rather than faunal 

evidence, since the recognizable forms are not suiliciently characteristic for close correlation. 

·Marcellus shaZe.-Fissile black shale, referable to the Marcellus, has been reported to 

occur in New Jersey along the bed of the Delaware River a few miles below Port Jervis, but in 

recent years the exposures have apparently been buried by silting up of the channel. This is 

the highest of the Devonian beds exposed in the State along the Delaware River, but in the 

Green Pond .Mountain area still younger beds occur. 

a Weller, Stuart, New Jersey Geol. Survey, Paleontology, vol. 3,1903, p. 90. 

b Second Geol. Surv'"y Pennsylvania, Rept. G6, 1882, p. 131. 

c Shimer, H. W., Bull. New York State Mus. No. 80, 1905, p. 175. 

dWeller, Stuart, op. cit., p. 96. Shimer, H. W., op. cit., p. 184. 
296 INDEX TO THE STRATIGHAPHY OF NORTH AMERICA. 

DEVONIAN FORMATIONS IN THE GREEN POND MOUNTAIN AREA. 

Kanouse sandstone.-The Kanouse sandstone, the lowest Devonian formation of the 

Green Pond Mountain region, is a thick-beclcled, fine-grained conglomerate below and a greenish 

sandstone above, having a thickness of about 215 feet. Although fossils are not rare, yet as 

a rule they are obscure and many of them are so greatly distorted that their identification is 

impossible. So far as recognized they indicate an Onondaga fauna, and these beds may be 

interpreted as the shoreward correlatives of the Onondaga limestone. It is the formation 

which in the New Jersey Geological Survey reports has been called the Newfoundland grit. 

Its outcrops form a narrow belt parallel to the Decker Ferry limestone but separated 

from it by a narrow interval. In the upper Delaware Valley, as noted above, there are seven 

formations aggregating nearly 900 feet in thickness between the Decker Ferry and the Onondaga. In the Green Pond Mountain region none of these has been recognized and, if present 

at all, it can be only in very attenuated form. 

Pequanac shale.-The Kanouse sandstone apparently grades upward into a black and 

dark-gray thick-bedded slaty shale (the "Monroe" shale of Darton and others). Cleavage 

is usually strongly developed so that the bedding planes are not always readily discernible. 

The thickness is estimated at 1,000 feet. This formation is probably conformable upon the 

Kanouse sandstone, but the contact has nowhere been observed. It contains a somewhat 

meager fauna, among which, however, is the characteristic Hamilton species Tropidoleptus 

carinatus, so that its reference to this period is beyond question. • 

Bellvale sandstone.-The Bellvale sandstone is scarcely more than a continuation of the 

Pequanac shale, but the beds are coarser and more sandy. The average thickness is estimated 

at 1,800 feet. The few fossils found are all Hamilton species. 

Skunnemunk conglomerate.-The Bellvale sandstones grade upward into a coarse purplered massive conglomerate, the white quartz pebbles of which are sometimes 6 or 7 inches in 

diameter. Beds of red quartzitic sandstone alternate more or less frequently with the conglomerate and there are many gradations between the two. It forms the great mass of Bearfort Mountain in New Jersey and of Bellvale and Skunnemunk mountains in New York. It is 

the youngest Devonian formation in New Jersey and rests upon beds known by their fossils 

to be of Hamilton age. Whether it is the exact equivalent of the Chemung-Catskill can not 

be determined. 
DEVONIA~. 297 

K 17-18. NEW YORK. 

· According to the nomenclature of the present New York State Survey, the 

classification of the Devonian of that State is as follows: 302 

Systt>m. 

( :arboniC'. 

Devonic. 

Summary ofclassijication ofthe New York Devonic. 

[According to .John J\I. ClarkP. Dlescending onlPr.] 

Group. Stag('. 

I . I PPnnsylvanian. I Olean conglomerate. 

I Mississippian. 

1:-----,------1------~~~~--~~~------

Knapp beds. 

Oswayo beds (Panama conglomerate). 

Cattaraugus beds, including Wolf Creek conglomerate. 

Chautauquan. 

Seuecan. 

Erian. 

I 

Ulsterian. 

l'hl,rnung beds (Catskill sandstone, local facies). 

Portage beds (Xaples, Ithaca, Oneonta, Hherburne beds, local · facies). 

Genesee shale. 

Tully limestone. 

Moscow shale. } Ludlowville shale. Hamilton. 

Skaneateles shale. 

Cardiff shale. 

Marcellus shale. 

I 

Onondai!'a liJ?estonc. 

Schoharw gnt. 

------- ,---~~---~ ----~-~-~---

Oriskanian. 

Helderbergian. 

Esopus grit. 

Oriskany beds. 

Port Ewcn limcst01w. 

Becraft limestone. 

1 New Scotland beds. 

: Coeymans limest01w. 

------~---- -------- ---~------

These formations vary greatly in thickness from east to west and north to 

south. The Helderbergian strata do not occur in the western part of the State. 

The Oriskany sandstone overlaps westward into Ontario; but the Schoharie and 

Esopus are of local distribution only. The Onondaga limestone and the Hamilton 

and Marcellus shales are relatively widespread, as is the Genesee, or its equivalent; 

but the Tully and Portage are more restricted. The Chemung and particularly the 

Catskill are very thick near-shore and the latter in part continental deposits of the 

Bay of New York and its southern extension into Virginia, and they are represented 

farther west by the Upper Devonian shales. 

Hall 397 described the "Lower Helderberg" as follows: 

The Lower Helderberg group, which constitutes the more important portion of the strata 

from .which are derived the fossils of the present volume, has been so termed from its very 

complete development along the base of the Helderberg Mountains, constituting, in this part 

of New York, an important fossiliferous group. In some parts of the Helderberg Mountains 
298 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

and along the Hudson River at Rondout and at Schoharie and elsewhere the lowermost beds 

of this group rest directly upon the Waterlime beds, which we regard as the uppermost member 

of the Onondaga salt group, indicated as a separate formation by reason of its economical 

importance and likewise characterized by certain peculiar fossils, while the marls of the Salt 

group are usually nonfossiliferous. 

The lowest member of the Lower Helderberg series is a thin-bedded, often thinly laminated 

dark-blue limestone, which, from the abundance of its tentaculites, has been termed the Tentaculite limestone. Its color, texture, and composition contrast strongly with the rock below. 

The second member of this group is a thin mass of limestone, consisting almost entirely 

of the coral Stromatopora, and constitutes a very persistent member of the group; to this 

succeeds a limestone charged with great numbers of the broken shells of Pentamerus galeatus 

and known as the Pentamerus limestone. This graduates above into a shaly formation, which 

was designated in the New York reports as the Delthyris shaly limestone, from the abundance 

of this genus of fossils. It is the most fossiliferous member of the group. * * * This shaly 

limestone, in physical character and composition, corresponds nearly with the shaly member of 

the Niagara group and contains numerous similar or representative forms. 

To this succeeds a compact crinoidal limestone, and above this is a mass of bluish-gray 

limestone, charged with Brachiopoda, among which a Pentamerus similar to P. galeatus is so 

abundant that the rock has been termed Upper Pentamerus limestone. 

A comparison of the species shows that the fossils of the Lower Helderberg rocks are 

analogous to those of the Niagara group and contain among them certain species which we 

regard as representative forms of the Silurian species in Europe; and we can not do otherwise 

than retain this series as a member of the Silurian system. 

In 1874 Hall 398 published a detailed description of the distribution of the" Lower 

Helderberg" and its relations to the Niagara and the intervening "Onondaga salt 

group," with a map of the eastern United States illustrating the occurrence of the 

three terranes. 

Schuchert 711]) quotes Hall's description and gives an account of the representatives of the Helderbergian in several States and Canada, together with an extended 

discussion of the faunas, from which he concludes: 

With these facts there is presented a great paleontological break between the Siluric and 

Devonic at the top of the Cayugan group. The succumbing of the normal marine faunas of 

the Niagaran group is undoubtedly associated with the red gypsiferous and saliferous sediments 

of the Cayugan group. If the latter had a normal marine fauna instead of one of peculiar 

Crustacea, the continuity of life from the Niagaran to the Helderbergian would be probably 

complete. However, in most areas outside of New York and Ohio, there is a great hiatus 

between the Niagaran and the Helderbergian, which tends to make a clear and easily discoverable line for field geologists in separating the Siluric from the Lower Devonic. 

* * * * * * * * * 

From the foregoing summary of the Helderbergian fauna it is evident that most of the 

characteristic Siluric genera of trilobites, brachiopods, and crinoids are there absent. This 

might be expected, for, as has been seen in the previous chapter, about 2 per cent of the Helderbergian fauna are derived from the Siluric. On the other hand, in some of the trilobites, Bryozoa, 

and pelecypods, many of the gastropods, but more particularly in the diversified brachiopods, 

are met organic groups which in their culmination are characteristic of the Devonic. It can not 

be denied that the Helderbergian fauna has a Siluric facies, yet these types either have greater 

differentiation in species or the forms attain a larger size. The fact that 9 per cent of the 

Helderbergian fauna pass into a generally accepted Devonic horizon, the Oriskany, outweighs 

the evidence of a Siluric facies and specific derivatives. The writer therefore concludes that 

the Helderbergian has a fauna unlike the Siluric, but one in harmony with the Devonic and its 

positi.on near the base of that system. 
DEVONIAN. 299 

Neither of the Helderbergian zones can be regarded as the deeper-water facies of the littoral 

Oriskany, not only because the fauna of the latter has a more decided Devonic aspect, but also 

for the fact that wherever the two formations are present the Oriskany always overlies the 

Helderbergian. As far as known, there is no interlamination, and in New York, where the 

stratification is simple, there is a regular sequence. Where the older Oriskany is absent there 

is a slight unconformity between the Helderberg and the later Oriskany. This unconformity 

becomes a decided one in going from eastern to central New York, because the later Oriskany 

gradually comes to overlie successively the various members of the Helderbergian and finally 

the Cayugan. 

The Oriskany sandstone is thus desCi'ibed by Hall: 397 a 

The Oriskany sandstone everywhere succeeds to the upper members of the Lower Helderberg group and at several points extends beyond the known geographical limits of the latter. 

In the greater number of localities within the State of New York the transition from the upper 

calcareous beds of one group to the siliceous or sandy beds of the other is very abrupt, while 

in other instances there is an intermingling of calcareous matter in the lower beds of the sandstone. In these instances, however, as well as in others, the siliceous material appears to have 

been to a considerable degree in the condition of gelatinous silex, producing a rock approaching 

in character to hornstone; while other examples present an appearance as if the grains of silex 

had been softened, or agglutinated by a siliceous paste. In its more fossiliferous parts the rock 

is a mixture of silica and carbonate of lime, and the action of the weather, dissolving and removing the latter, leaves a grayish-brown porous mass, embracing the casts of the interior and 

molds of the exterior of the fossil shells. In many places the rock consists of a sandstone of 

nearly pure white, or graduating from white to buff-colored; in more southern localities it often 

presents the aspect of a siliceous limestone, not differing greatly from the succeeding limestones. 

Schuchert 7110 gives the following account of the character of the Oriskany in 

New York: 

In a general way it may be said that the Oriskany formation extends with many interruptions along the eastern and northern flanks of the Helderberg Mountains of New York. Along. 

the northern sicle the Upper Oriskany only is known to be present, exceedingly variable in 

thickness but never more than 30 feet, diminishing in volume and resting westwardly upon the 

successive lower horizons of the Helderbergian and finally on the Siluric. In the region of 

Cayuga Lake it is sparingly present, and is practically absent west of Ontario County, the 

Corniferous or Onondaga then resting directly on the Salina or W aterlime. Beyond the Niagara 

River, to the northwest of Cayuga, in Ontario, the Oriskany reappears irregularly over a very 

limited area, again overlying the Salina, and is from 6 to 2fi feet thick. Southerly, along the 

western side of the Hudson River, the Upper Oriskany is very intermittent and often but 2 or 

3 feet thick. On Becraft Mountain there is an outlier of Oriskany. In Orange County the 

Oriskany again appears to thicken, and in the Neversink Valley the thickness is about 125 feet, 

and at this point it is intimately connected with the Helderbergian. In New Jersey, and 

particularly in the eastern Appalachian folds of Pfmnsylvania, the Oriskany in its lith:)logic 

character is ever changing from sandy shales, sandstones, and chert beds to coarse conglomerates. 

Its thickness also increases from north to south; in northeastern Pennsylvania it is from 50 to 

125 feet thicl~, and on the Lehigh River, below Bowmans, it is fully 200 feet. 

Clarke 157 a has thus stated the distribution and relations of the Helderbergian 

and Oriskany: 

In New York the deposits constituting the earliest members of the Devonic series are, at 

the bottom, (1) the Helderbergian and, overlying, (2) the Oriskanian. There is a demonstrated 

gradation of the sediments and the faunas of the lower into the higher, and those at the summit 

of the Helderberg series-Port Ewen beds-carry so large a representation of Oriskany species, 
300 INDEX TO THE STI{ATIGHAPHY OF NORTH AMERICA. 

as shown by recent analyses, that they may be wisely regarded as indicating the passage of the 

earlier into the later fauna. 

The Helderbergian rocks (in the Helderberg Mountain region comprising the following 

divisions from below upward: (1) Coeymans limestone, (2) New Scotland limestone and shale, 

(3) Becraft limestone) enter New York from the southeast along the New York-New Jersey line 

and end northward in an abrupt escarpment facing east and north in the southern angle of the 

present Hudson and Mohawk rivers. Of this heavy sheet of calcareous strata there is no trace 

in New York east of the Hudson River save two small synclinal outliers in Columbia County, 

Becraft Mountain and Mount Bob. As the formation progresses northward from its entry into 

the State its thickness increases to where it is abruptly cut off in an erect wall. The Helderberg 

escarpment carries in its very topography the evidence of a former wide extension on toward 

the east and northeast. The continuation of this formation westward in New York is notable 

for its rapid thinning and quick disappearance. The subdivision at the Helderberg Mountain 

is soon lost westward. The lower division or Coeymans limestone appears to be that extending 

farthest, as far as the eastern limits of Onondaga County, but the narrow east and west extent 

of the Helderberg sea is shown by the entire absence of the higher divisions far west of Schoharie 

Creek. 

The Oriskany period succeeding was a time of transgression over the Helderberg deposits 

beneath. Then the northern coast line in western New York was broken and em bayed. While 

calcareous deposits were formed in the deeper water of the southern reaches, the shore deposits 

of sand extended westward to Buffalo, in part over eroded surfaces of Siluric limestones to which 

the Helderbergian sediments had not extended. We have had occasion to show that from the 

Helderberg westward the sandy shoal-water deposits of this Oriskany time are lenses and thin 

sheets, often disconnected, in some places rising to considerable thicknesses of friable quartz shore 

sand into which the waters have rolled the organic remains of the outer sea. These lenses we 

conceive were separated by tongues of land dividing the embayment,s of the shore line. The 

Oriskany in our view presents in New York a twofold facies, that of the deeper littoral represented by the calcareous deposits from the Helderberg southward to Port Jervis and that 

of the shallow littoral from Schoharie westward; yet it is quite possible that the latter deposits 

are of later date than most of the former and represent the final transgression of shore sands 

over' the sinking land of Helderbergian time. 

The Oriskany sandstone is succeeded by the Esopus shale, which is described 

by Darton.227 a The Esopus is said to be "in greater part a fine-grained arenaceous 

deposit of dark-gray color." 

A bout Schoharie and westward to its termination it is a moderately hard sandy shale varying 

in color from dark gray or buff to light olive, but east and south with increasing thickness the 

color becomes darker, the texture of the rock is harder, and slaty cleavage is general. * * * 

The formation has a thickness of 110 feet at Clarksville. 

The Ulsterian of the New York State Survey comprises, in addition to the 

Esopus shale, a locally developed but not extensive formation known as the Schoharie 

grit and the widespread Onondaga limestone. 

Darton 227 describes these formations, together with others of the Helderberg 

Mountains. 

The Schoharie grit is a local deposit which is characteristically developed near 

Schoharie and extends through Schoharie and Albany counties to Ulster County. It 

is a very arenaceous limestone which merges into the Onondaga above but is more 

sharply separated from the underlying formation. It is locally absent and the 

Onondaga then rests on the Esopus shale. · 
DEVONIAN. 301 

The Onondaga limestone, as the term has been applied since 1894, comprises a 

lower and an upper member called by Hall 396a "Onondaga" and "Corniferous," 

respectively, and covers the original application of the descriptive name "Corniferous" of Eaton. The extension of the geographic term Onondaga to the whole 

was made by HalJ.399 In 1843 Hall 396 described the lower member thus: 

Throughout the greater part of the Fourth district the impure limestone terminating the 

Onondaga salt group is succeeded by the Onondaga limestone, with usually the intervention 

of a few inches of sandstone before noticed, which in ordinary observations might be entirely 

overlooked. There is also sometimes a thin band of nonfossiliferous bluish-gray limestone.· 

The range of this formation is in an undulating line having a general east and west direction 

throughout the district, extending eastward to the Hudson River and westward far beyond 

the Niagara into Canada. Its northern outline is everywhere well marked, forming together 

with the next succeeding rock the second great limestone terrace, which rises to the south of 

the valley marking the range of the Onondaga salt group. 

* * * * * * * * * 

This rock is subordinate in thickness and continuation to the next succeeding mass, and 

was not separated from that by Prof. Eaton. Indeed for all practical purposes they may 

be regarded as one formation, the lower part, where fully developed, being marked by an 

assemblage of fossils which sufficiently distinguish it. 

Its usual characters in the Fourth district are a light-gray color often approaching to white, 

more or less crystalli~e in structure, and containing numerous fossils. In many instances this 

mass, like the encrinal limestone at Lockport, seems almost entirely composed of broken and 

comminuted fragments of crinoidea and corals, sometimes extremely attenuated, and at other 

times fragments of large size are preserved. 

* * * * * * * * * Sometimes the mass is fine grained, more compaet in texture, and of a darker color; when 

it has this character, few fossil remains are detected in it. The layers are usually separated by 

thin seams of greenish shale, which often divide blocks of the stone into wedge-form and 

irregular laminre. 

* * * * * * * * * The Onondaga limestone in many places contains noclules or thin interrupted layers of 

chert or horns tone (usually called flint), and sometimes the Favosites are partially clissolved 

and the cavities lined with silex in the form of chert, chalcedony, or crystals of quartz. The 

alimentary canal of the crinoidal columns is frequently lined with crystals of quartz, and the 

chambers of Orthocera, as well as the cavities of other shells, often present the same appearances. 

Its characteristic features, when well developed, andwhichare always much more prominent 

than the lithological or mineral characters, are the presence of Cyathophylli, Favosites, and fragments of crinoidal columns. These always accompany it in situations where it is sufficiently 

developed to be of much impmtance either in economical consideration or geological interest. 

Regarding the upper member of the Onondaga limestone Hall 3961 says: 

This rock is one of the most persistent of any in the series, ancl at the same time maintains 

a uniformity in lithological character and in the occurrence of certain fossils scarcely possessed 

by any other. It is known to extend from the Helderberg Mountains, on the Hudson River, 

to the Niagara River, and thence far into Canada. 

* * * * * * * * * 

Under the Corniferous limerock of Prof. Eaton were induded this rock and the Onondaga 

limestone of the reports, the latter constitutir~g his "Ceratial rock," so named from the abundance of Cyathophylli which it contains. The name Corniferous is continued as being peculiarly applicable to this rock, though the other limestones contain the same mineral. This 

is the highest limestone of importance in the series, which continues throughout the district. 
302 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

In lithological character this rock varies to a considerable degree in its range through the 

district, being at the eastern extremity a fine-grained, compact limestone, scarcely presenting 

any crystalline grains. Its color varies from a light grayish blue to dark blue or black, and 

it is sometimes even of a light-gray or drab color. It contains numerous nodules of hornstone 

and the strata are sometimes separated by irregular layers of the same. In other localities 

these layers of hornstone increase in number and thickness to the almost entire exclusion of 

calcareous matter, and they then present a very harsh outline. * * * 

At the eastern end of the district the hornstone is intermingled and interstratified with the 

calcareous strata, the whole very dark colored. 

* * * * * * * * * 

The rock for the greater part seems to have been composed of finely levigated calcareous 

mud, probably derived from the destruction of corals at distinct points, whil~ at the same 

time siliceous matter often formed no inferior part in its production. The characters which 

distinguish the last rock, viz, the presence of corals and Crinoidea, are rare in this and form 

no essential feature. Fossils are generally few and for the most part consist of shells. Some 

portions, it is true, though of small extent, appear as if they may have resulted from the 

destruction of corals. 

A later account of the Onondaga is given by Grabau. 381 

The Erian of the New York State Survey, which comprises the Marcellus and 

Hamilton shales, has been the object of extensive investigations. Hall 3960 thus 

described the Marcellus: 

This rock admits of two divisions. The lower is very black, slaty, and bituminous and 

contains iron pyrites in great profusion; some portions are calcareous, and it is always marked 

by one or more courses of concretions or septaria, which are often very large. This division 

terminates upward by a thin band of limestone, above which the shale is more fissile, and 

gradually passes from black to an olive or dark-slate color. 

In general characters the lower part resembles the Utica slate and is not distinguishable 

from the Genesee slate in its general aspect; it is, therefore, more properly a slate than a shale, 

if the distinction is to be continued. For practical purposes there is little advantage in separating 

the upper division of this shale from the Hamilton group. The line of separation is nowhere 

well marked, the change in lithological character being gradual, while some of the fossils continue from one to the other. 

The fmely levigated mud composing this rock indicates a period of great tranquillity in 

the waters, moved probably only by currents sufficient to transport the materials over the 

wide extent we find them. The nature and condition of the fossils also indicate a quiescent 

period, for their forms are among the most delicate and their parts are usually preserved in 

the greatest perfection. In some instances, however, from their great numbers, they are 

packed closely together and fracture on the separation of the laminre. 

* * * * * * * * * 

In many places this rock contains so much bitumen as to give out flame when thrown into 

a fire of hot coals. 

Under the title "Hamilton group" Hall 396d describes the middle Devonian: 

This group consists of several members which may be considered distinct, but which, 

when viewed in connection, present so many features in common that they are all recognized 

as the products of one period, and thus constitute one great group. In the Fourth district, 

the only changes recognized in lithological products are from shaly to calcareous, with occasional thin beds of limestone, and more rarely of sandy shale. 

The group, as a whole, presents an immense development of dull olive or bluish-gray 

calcareous shales, which, on weathering, assume a light-gray or ashen tint; some portions 

become brownish on exposure, but these are of small thickness in this district. At a few points 

the shale becomes darker or black and exhibits a tendency to slaty structure, but as a general 
DEVONIAN. 303 

character the cleavage is irregular and oblique to the planes of stratification. On weathering, 

where the edges are exposed, there is manifested a slight tendency to slaty cleavage. 

From the wide and even distribution of the materials of this group, it was evidently produced during a period of great tranquillity, when the fmely levigated mud was transported 

over wide areas by gentle oceanic currents. The great profusion and variety of organic forms 

proves also the quiescent condition of the ocean, which, together with the slightly calcareous 

nature of the mud, favored the growth and distribution of the Testacea. 

The upper part of this group, in the Fourth district, bears a very close analogy in its lithological nature to the shale of the Niagara group, and in abundance of organic remains it is even 

more prolific. The forms of the latter are, however, of entirely different species, though corals 

and shells of similar genera abound, and tril.obites of the same and different genera. 

Concretions or septaria, in well-defined and often fantastic forms, are common in every part 

of this group. In many instances the calcareous matter has concreted around some organic 

body, or a nodule of iron pyrites seems to have been the center of attraction. In such instances 

we often find numerous fossils embedded in them or attached to their outer surface. The 

greater number, however, are well-defined spheroidal masses, with or without seams of crystalline matter and not containing any organic body. Others, and particularly in the lower part 

of the shale, are small, spherical or elongated, and with a small perforation through their center, 

in the manner of the common nodules or other concretionary forms in recent clay beds. 

Organic forms abound throughout the group, but they vary somewhat in the different 

parts. In the lower division the most abundant are those of Orthis, Atrypa, and Strophomena, 

with some spiral univalves; while above this portion great numbers of Avicula, Cypricardia, 

Nucula, and other similar forms abound, with fewer of the genera Orthis, Delthyris, etc. In the 

next division Delthyris, Strophomena, and Atrypa abound, to the almost entire exclusion of 

the forms before mentioned. In the same situation with these we find numerous species of 

corals; Cyathophylli, Favosites, and other forms are abundant, while fragments of crinoidal 

columns are everywhere scattered through the mass or, spread evenly over the surface, form 

thin layers of themselves. Many of the species of this division are discontinued and their 

place supplied by others of the same genera in the higher part of the group. * * * 

Although this group is so widely spread and evenly distributed and of uniform character 

over the western part of the State, still at its eastern extremity the lithological character is 

widely different. The shales are more or less arenaceous and some parts are well-marked 

sandstone. The proportion of sili~eous and argillaceous earth is nearly reversed from what it 

is in the same rocks farther west. The mass varies from sandy shale to shaly sandstone and 

even tolerably pure sandstone. This character gradually changes to the westward, the sand 

diminishing and the clay increasing. The features presented by this group at its two extremes 

and along its whole length offer one of the most instructive exhibitions of the varying character 

of mechanical deposits. The facts prove the origin of the materials to have been at the east 

or southeast. The force of the current which drifted them into the ocean was sufficient only 

to carry onward the coarser particles to a certain distance, where they were deposited. The 

finely levigated mud was carried beyond this point, being floated by less force than the sand. 

Some portion of the clay was deposited with the sand toward the central part of the State, and 

but little of the latter extended beyond this point. Finally the current became more gentle 

and the clay was deposited to a certain extent, beyond which the power of the current was 

insufficient to carry even this material, and the deposit consequently thinned out in that 

direction. * * * 

This change in the nature of the materials is accompanied by an equally marked change 

in the fossils embedded in the different parts of the group. In the eastern part of the State 

Avicula and Cypricardia, with Nucula, etc., prevail in immense numbers, while at the extreme 

western margin, though in precisely the same position, they are of the rarest occurrence, while 

numerous forms of Delthyris and Atrypa abound. 

The above-quoted descriptions by Hall apply particularly to the Fourth district of the early Geological Survey of the State-that is. the region south of Lake 
304 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Ontario and west of Cayuga Lake. 8imilar accounts with local variations are given 

in the reports of Vanuxem 829 and Mather. 578 

-With reference to the Hamilton as exposed on the southeastern shore of Lake 

Erie, Grabau 376 may be consulted. He gave the following classification: 

The following formations arc exhibited in the sections: 

Chemung group (Portage stage): 

Naples shales. 

Genesee slate. 

Hamilton group: 

Hamilton stage: 

Moscow or upper shales. 

Encrinallimestone. 

Hamilton or lower shales. 

Marcellus stage: 

Transition shales. 

Marcellus shales. 

The Hamilton of Cayuga Lake, New York, was made the subject of a special 

study with reference to its fauna by Cleland, 160 who states: 

The Hamilton formation, including the Marcellus shales, is in this region, as shown by the 

Ithaca well section, 1,224 feet thick. It is bounded above by the Tully and below by the Onondaga (Corniferous) limestone. 

Cleland divided the Hamilton of the Cayuga section into 25 faunal zones, each 

of which is described in detail in his report, together with the composition of the 

faunules. 

Williams's later studies in classification 935' 935a led him to the following arrangement of the Ithaca section: 

Revised class~fication and nomenclature of the section passing through Ithaca, N. Y. 

~erie~. Formation. :Members and lentils. 

-- -------

[I Fall Creek conglomerate lentiL ......................... - II Chemung (shale and sandstone) Wellsburg sandstone member ..... _ ........ _ ....... _ .... , 

§ , Cayuta shale member ........... · .. · · -· · · · · · · -· · · · · · · · · ·I >< 

;:; 

~ 

~ 'H 

0 

UJ 

Nunda (shale and flagstone). 

Q) --····----- ----

·c 1 

&: I Genesee shale. 

.; I Tully limestone-. --

-~ 

~ I Q) [ IIamilton shale. 

·c 

>£! 

Marcellus shale. 

! Enfield shale member ........ ---~-~~~. --~ _-_ .... ---~- .. _I 

Ithaca shale member ................................... _

1 

Sherburne flagstone member ............................ . 

Thickness (feet). 

0-10 

600-650 

600 

550-800 

a 80--460 

188-260 

125 

10-30 

125 

------~- ------:_-----

Onondaga limcstom~. 125 

------------------ --------- ------

Oriskany sandstone. 0-4 

a In the chart as published in Science (vol. 24, p. 366) this figure is 300 feec. 
DEVONIAN. 305 

It ]s difficult to follow any description of the Middle and Upper Devonian of 

New York without a knowledge of the conditions which have led to different classifications by several geologists for sections occurring in the eastern or western parts 

of the State. The strata are chiefly shale, sandy shale, shaly sandstone, or sandstone, which in any one section may present distinctly recognizable differences but 

which do not retain the same characters or distinctions from place to place. The 

faunas also vary in vertical and horizontal distribution and are to some extent 

recurrent. The divisions particularly involved in this vaguely classified series are 

those above the Hamilton, namely, the Tully limestone, Genesee shale, Portage 

group, and Chemung formation. 

The Tully limestone was well described by Hall 396e and has been made the 

subject of a special paleontologic and correlative study by Williams,931 who states: 

The Tully limestone is a zone of argillaceous limestone, ranging from a few feet to over 50 

feet in thickness, the outcrop of which crosses the middle counties of New York State from 

Ontario to Chenango counties but is not clearly recognized in the· sections south of New York. 

In New York the outcrop is lost to the eastward and to the westward, not so much by thinning 

out as by a decrease, until unrecognizable, of the calcareous elements, and a failure of the peculiar species. In the central part of its outcrop this limestone appears at the top of the Hamilton formation, which consists of a series several hundred feet thick of soft shales, with a few 

more or less calcareous zones; and it is followed immediately by a black shale which gradually 

loses itself by alternate. oscillation in a gray, more or less arenaceous shale and argillaceous 

sandstone, known in New York as the Genesee shale and the Ithaca group, and the more sanely 

portion above as the Portage group. In the region where the Tully limestone is well developed 

the black shales contain a fauna corresponding to that of the Cardiola retrostriata zone of Europe, 

and there is in the sanely shales above a fauna rich in Goniatites where best developed. * * * 

For this study the more important species in the Tully limestone of New York are the 

brachiopods.a * * * Besides these are species belonging to other orders.a 

* * * * * * * * * I have examined a large amount of material from genuine Tully limestone, and also considerable more doubtfully referred to that horizon. In most places the Hamilton rocks are 

richly fossiliferous immediately under the Tully limestone. These f-ormer, though mainly shales, 

contain limestone beds which in hand specimens are rarely distinguishable from the genuine 

Tully above; but the characteristic species of the Tully are wanting and characteristic Hamilton species arc abundant in them. Much confusion has thus arisen, and the Tully fauna, as 

reported in lists,b is very imperfect by the inclusion of many species which do not belong in 

the limestone. 

There are about 50 genuine Tully limestone species. Of these less than 25 are at all common, and the other 25 are Hamilton species which do not appear above the Tully, or are unique 

forms of Hamilton types. Of the more or less common Tully forms fully one-half are also 

clearly Hamilton species or their descendants, or are unique forms. 

The change in fauna which begins with the Tully limestone and makes the characteristic 

upper Devonian fauna includes the appearance inN ew York of at least ten or a dozen species 

which have closer ailinities with species of the middle Devonian in Europe than with any previous species in the New York series. 

a For lists see the work cited.-B. W. 

b See list furnished by S. G. Williams (Sixth Ann. Rept. State Geologist, Albany, 1887, p. 26). A considerable 

number of the species reported in this list I have examined in the collection made by the author of the list and find 

them and the rock containing them indistinguishable from specimens obtained at the same locality below the Tully 

limestone layers filled with Hamilton species but never in the Tully limestone itself. 

48011°-12----20 
306 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Regarding the strata above the Tully limestone, Hall's remarks 396r "preliminary to the following rocks and groups" may still be read to advantage: 

In the Fourth district the Tully limestone terminates all those deposits in which calcareous 

matter forms an essential part. In all the higher rocks this material, when existing, is the 

result of the destruction of organic bodies; and in the few instances where it appears the origin 

is unquestionable, for the fossils still retain so much of their original form as to be readily recognized. This rock forms a strong line of demarcation not only in this respect, but also as regards 

fossils, very few forms which are known below continuing into the rocks above. The lithological 

character of the products above this rock are throughout more or less similar, while they differ 

from those below; and, with a single exception, lithological character is a sufficient guide for 

distinguishing the different strata. 

This contrast of character is more marked toward the western extremity of the district 

than it is farther east, and finally, on its eastern extreme, there is a greater similarity in the 

lithological features. This change is likewise attended with the occurrence of some of the 

fossils of the lower group in the rocks of the higher, the nature of the two being very similar, 

although the Tully limestone is in its greatest force; while at the west, where it does not exist. 

no such mingling of the fossils is known. 

At Ithaca, for example, where we are far above the Tully limestone and where the rocks 

are well marked by an abundance of fossils peculiar to themselves, still we find the Microdon 

bellastriata, the Modiola concentrica, and some others, and I have even detected the Oalymene 

bufo and Dipleura delcayi in the same association. Still farther east there is a greater mingling 

of species of the lower rocks with the upper and a nearer approach constantly in materials of 

composition. These circumstances, in the eastern portion of the State, render it difficult to 

point out the line of demarcation between the lower and higher rocks of this division. 

At the eastern extremity of the State, also, the Tully limestone does not exist, and therefore that guide to the line of division between the lower and higher groups is wanting. .The 

absence of this rock and the similarity of lithological products, as well as the mingling of the 

organic remains of the !ower rocks, render it impossible to make a distinction in groups with 

the same degree of satisfaction as· farther west. By reference to the section along the Genesee 

River it will be seen that the Genesee slate, a black carbonaceous mass, is succeeded by shale 

of a deep-green color and well defined above. This is succeeded by flagstones, which alternate 

with shale of a less deep green color and often with black shale. These again are followed by 

a greater proportion of sandstone, often thick bedded, and presenting far less of the characters 

of those below. 

These rocks are well exposed on the Genesee River, and there can be no possible room for 

error in their examination. The whole thickness here exposed is scar.:;ely less than 1,000 feet; 

and throughout this thickness there is as yet no fossil known which occurs in the Chemung 

group to the south and above these rocks. These circumstances led to the separation of this 

portion of the system and the adoption of Portage or Nunda as the locality designating the 

group. Farther east the green shale (Cashaqua shale) is often darker in color and more sandy, 

becoming largely interstratified with flagstones which have much the character of those which 

lie above it on the Genesee, except in the absence of a peculiar species of Fucoides. At the same 

time the small Avicula, which is so abundant in the Genesee slate, is almost equally abundant 

in the green shale and flagstones at Penn Y an. 

Again, when we go westward as far as Lake Erie, we find that instead of the flagstones 

succeeding the green shale, as on the Genesee, a black shale is the first mass above. This soon 

gives place to green shale, and we have alternations of green and black shale for many hundred 

feet, before coming to the thin-bedded sandstones. 
DEVONIAN. 307 

Proceeding with the description of the rocks, Hall says regarding the Genesee 

shale: 

Superimposed upon the Tully limestone, or, in its absenc0, resting upon the Moscow shale, 

we find a great development of argillaceous fissile black slate. Where its edges only are exposed 

it withstands the weather for a great length of time and often presents mural banks in the 

ravines, river courses, and upon the shores of lakes. ·where the surface of the strata are exposed it 

rapidly exfoliates in thin even laminl£. On disintegration, it is often stained with iron, owing 

to decomposition of pyrites; but in many instances and the greater number of localities it retains 

its deep black color. In this it is distinguished from some beds of black slate in higher situations, which always become stained with hydrate of iron on their edges and upon the surface 

of the laminre. 

In color and general characters it greatly resembles the Marcellus shale; and aside from 

position, it would be difficult to distinguish the two in the absence of fossils. * * * 

In lithological character this rock is entirely uniform throughout the district, presenting 

itself upon the margin of Cayuga Lake and upon Lake Erie, having the same deep black color 

and laminated slaty structure. Neither is there any change in its organic remains; the same 

forms, and many of them almost equally abundant, are found throughout its entire extent. 

The greater portion of this rock is destitute of fossil remains, and it is only toward the upper 

part that they occur. 

Under the heading "Portage or Nunda group" Hall 3Mg states: 

This group presents an extensive development of shale, shales and flagstones, and finally 

some thick-bedded sandstone toward its upper part. Like all the other mechanical deposits of 

the system, as they appear in New York, it is extremely variable in character at different 

and distant points. * * * 

From its superior development along the banks of the Genesee River in the district formerly included in the town of Nunda, now Portage, it has received that name to distinguish it 

from the higher rocks, which possess some differences in lithological characters but a more 

striking dissimilarity in organic remains. 

Hall distinguished the Cashaqua shale, Gardeau shale and flagstones, and Portage sandstone as formations of his "Portage or Nunda group" and described their 

characters in detail in the chapter devoted to that group. Clarke 153 has thus 

summarized Hall's account: 

The succession of strata exhibited in a series of beautiful exposures along the course of the 

Genesee River was described in some detail by Prof. James Hall in the fourth "Annual report 

of the survey of the fourth geological district of New York" (1840). 

The beds which lie directly above what was there termed the "upper black shale" (thus 

contradistinguished from the "lower black shale," the former now known as the Genesee slate 

and the latter as the Marcellus shale) were designated as the Cashaqua shales, taking their 

name from the creek entering the Genesee River from the east at Mount Morris. These are 

olive-green or gray clay shales alternating with bituminous shaly beds and with interbedded 

thin shales, sandstones, and flags. Upward in the rock series there is in general a gradual 

increase in the amount of arenaceous sediment, the sands and flags becoming increasingly predominant and the shale beds themselves more arenaceous. While the transition to these beds 

from those below is in all respects an easy one, yet there is a possibility of distinguishing them 

in the mass, and hence the upper beds were termed the "Gar(leau or Lower Fucoidal group;" 

the adjective term referring to the abundance of the so-called Fucoides graphica over the 

lower surfaces of the flags. A thick mass of heavy-bedded greenish or gray feldspathic and 

quartz sandstones above the Gardeau flags, representing the culmination of arenaceous sedi· 
308 INDEX TO THE STR~\TIGRAPHY OF NORTH AMERICA. 

mentation of this cycle, was termed the "Portage or Upper Fucoidal group," many of the layers 

containing vertical annelidan borings fillP<l witl1 mud, which have commonly passed under the 

name of Fucoides verticalis. 

In recognition of the fact that the distinction thus instituted in parts of this series would 

be difficult of application in actual practice, the same author, in 1843, applied the term "Portage 

or Nunda group" to the entire series lying between the uppermost beds of the Genesee slate 

and the upper limit of the heavy beds of Portage sandstones. Since that elate not only have 

the rock strata thus delimited in these western sections of New York been known in geologic 

literature as the "Portage group," but this term has been also, and properly, applied to all 

formations in whateyer sections of this State and bearing whatever faunas, between the horizon 

of the Genesee slate beneath and the earliest strata characterized by the incoming Chemung 

fauna above. 

Recent investigations indicate that the historical delimitation of the Portage group in the 

typical Genesee section does not express the comphte upward range of the fauna of this group. 

In the Genesee Valley the Portage sandstones are overlain by sandy shales and thin sandstones 

from 100 to 200 feet in thickness and in lithologic character, not unlike the Gardeau layers 

beneath; and through these beds the Naples or Intumescens fauna ranges, with slight accretions. Strietly speaking, this fauna is mainly confined to the more argillaceous layers, while 

toward the top a Chemung fauna appears in the more arenaeeous strata. But this alternation 

concerns only the upper portion of these b8ds. To this series of strata representing the prolonged existence of the Naples fauna the term '\Viscoy shales and sands has been applied. In 

protracting, upon the evidence of the contained fossils, the scope of the Portage group to include 

these beds, we shall not appear to violate propriety, for they did not eseape the observation of 

Prof. Hall, who at the close of his description of the Portage group says (1843, p. 248): "The 

Portage sandstone is succeeded by olive shaly sandstone and shale and this by black micaceous 

slaty shale with septaria; to this follow shales and coarse sandstones with fossils of the Chemung 

group.'' 

In the pages succeeding this quotation and in the second part of his contribution 

on the Naples fauna 154 Clarke describes and illustrates with maps the stratigraphy, 

paleontology, and geography of the later Devonian of New York. 

The "Ithaca group" was early distinguished by Hall, but later 396h included by 

him in the Chemung in the following terms: 

In the annual reports this name was adopted for designating the highly fossiliferous shales 

and shaly sandstones, so well developed at the inclined plane of the railroad and on the Cascadilla and Fall Creeks, near Ithaca. Subsequently an examination of the highly fossiliferous 

strata along the Chemung River, and particularly in Chemung County, resulted in the adoption 

of that name as designating this portion of the system. 

Succeeding examinations satisfied me of the identity of the formations at Ithaca with 

those of Chemung, and this opinion was advanced in the annual report of 1841. 

The reasons for merging the two in one were stated to be the impossibility of identifying 

them as distinct by any characteristic fossils. The same opinion is still entertained, after a 

full examination of the strata and a comparison of the fossils collected here and elsewhere in 

well-authenticated localities of the Chemung. There is scarcely a fossil known at Ithaca which 

is not found at numerous other localities; though it is true, not only of Ithaca but of many other 

places, that some of the fossils are confined to the single locality in which they occur. 

By careful and extended examination the Chemung group may be subdivided locally 

where it is most perfectly developed, but these divisions will hold good only over small districts of country, position and lithological character having had much effyct in producing these 

distinctions dependent on fossils. 
DEVONIAN. 300 

Later work has not sustained the identification of Ithaca with Chemung. 

Williams 930a first showed that Ithaca and Portage are equivalent. He said: 

Although the faunas [of the Ithaca and Chemung] are very similar, there can be no doubt 

that along the present meridian they represent two distinct geological stages. That they 

blended in some measure farther east may be possible, in the same way that it is probable 

that on going westward the Marcellus and Genesee stages blended. 

Although I do not know that the Ithaca fauna is an early stage of the Chemung fauna, 

I am persuaded that the two may be readily distinguished by their fossils. 

That the typical Chemung fauna is thus distinct from that of the Ithaca group and characteristic of a later stage, is shown, paleontologically, by the following considerations: 

The genera Spirifera, Orthis, Strophodonta, and Productella are common to both faunas, 

and are represented by numerous individuals at almost any fossiliferous exposures of either 

group. But for each genus the species are different. Spirifera is represented in the Ithaca 

group by Sp. mesocostalis var.·acuminata and the first variety of Sp. mesostrialis. 

The Chemung group is characterized by Sp. disjuncta, Sp. mesocostalis 2d var., a large, 

coarsely plicated, broad form, and Sp. mesostrialis 2d var., the wide mucronate form, neither 

of which is seen in the Ithaca group. 

Orthis, in the Ithaca group, is 0. impressa of the narrow variety, rarely wider than long. 

In the Chemung group 0. impressa is the second variety; wide form, with broad sinus; 

also there are 0. tioga and 0. carinata, neither of which is known in the Ithaca group. 

The Strophodontas of the Ithaca group are Str. mucronata, and the closely allied variety 

of Str. perplana var. nervosa. 

In the Chemung group Str. cayuta is the prevailing form, and a coarser, more irregular 

form of Str. perplana var. nervosa. 

Str. demissa is reported from both groups but is extremely rare in either. 

Productella is represented in the Ithaca group by P. speciosa and a small form I have 

identified as P. speciosa, small variety. In the Chemung it is P. lachrymosa and P. costatula. 

Besides these genera, Streptorhynchus is common in the Chemung group, and it is extremely 

rare, if it appear at all, in the Ithaca group. 

Amboca;lia umbonata var. gregaria is abundant in some stages of the Chemung group but is 

rarely ever seen at Ithaca. The latter two forms are seen below the Ithaca group, hence their 

absence there is evidence of modified fauna rather than extinction. 

These differences in the prevailing varietal or specific characters of common genera, which 

(as genera) are known to be common for a considerable range below and above the stages 

under consideration, I take to be more reliable evidence of actual difference in horizon than 

would be any number of distinct species of different genera in the two faunas. 

In the study of the Devonian of New York to which the bulletin just cited was 

a first contribution, Williams has developed essential general principles regarding 

the geographic and chronologie relations of faunas. The principles and the discussion of the evidence do not pertain to this account of stratigraphy, but .the 

application to the relations in New York is appropriate. Under the heading 

"Faunal dissection of the Devonian," "\Villiams 931 expresses the results of special 

studies as follows:-

Previous work in correlation had been conducted on the fundamental assumption that 

identity of fossils is sufficient evidence of identity of the formations containing them. In other 

words, it had been assumed that for purposes of classification in the time scale the formation 

and the fauna are identical. The way in which fossils have been customarily labeled has prevented a testing of the truth of this assumption. If there be any distinction in time value 

between the formation and its fauna, it is difficult to demonstrate it so long as the only name 

and designation of the fauna is that of the formation in which it was originally found. 
310 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

If the "Chemung formation" be extended below the fossiliferous strata of Ithaca, as it 

was in the literature before 1880, then the fossils in the "Ithaca group" belong to the Chemung 

fauna. When the Ithaca fauna was dissected and it was shown that the species were not those 

of the Chemung fauna above but were rather modified successors of the Hamilton fauna, it 

became clear that, faunally, the Ithaca group was not a part of the Chemung formation. 

Nevertheless, the term "Chemung" was still retained in general literature for the "period" 

which included both the "Ithaca" and "Chemung" epochs, so that the real issue was still 

obscured by the imperfection of the nomenclature which used "Chemung" with two meanings. 

The terms "Portage," "Hamilton," "Trenton," and "Niagara" are also applied in this 

double sense in the classification of formations, making it almost impossible to frame a statement which will express the thought that formations and faunas are discriminated upon 

different bases and that their limitations may not be identical. 

In order to demonstrate the actual facts in the case, it has been found necessary to collect 

a large number of statistics regarding the actual faunal contents of each zone in some wellknown formation, and also regarding the separate faunules ta"ken from outcrops of the same 

formation over an extended area. 

* * * * * * * * * 

It is now possible to state that the Tropidoleptus fauna of the Hamilton formation persists in its integrity above the top of the Hamilton formation; that in eastern New York it 

occupies a place in the column which is occupied in central New York by the Ithaca formation 

-and in the Genesee Valley by a portion of the Portage formation . 

• This state of things has been already demonstrated in respect to the position of the Catskill 

formation in the geological column. But the significance of the facts was obscured in that case 

by the fact that the Catskill as a pure formation is distinguished by its red sedimentation, 

which, therefore, was easily discerned in the field by the stratigraphical geologist; but the fossil 

evidence of the Chemung, though constantly annoying him, had not in his mind the distinct 

stratigraphical significance which he attached to the color ingredient in the Catskill. The evidence of the Catskill was clear, and if the fossils told another story, so much the worse for the 

fossils. This was his attitude. 

In the present case the faunas are of the same kind, made up of marine invertebrate fossils. 

They are distinctly marine in all cases, and the demonstration may be expressed in mathematical values. The statistics are sufficient and are gathered from a :field that is wide enough to 

make possible the comparison of the faunules in terms of composition, frequency, and abundance. The variation of species, though not yet demonstrated by the statistics, is strongly 

indicated by the increasing uncertainty in identification of the species in one direction, while 

the species are always positively identified in the central region. Great promises of future 

discoveries in this direction are offered by the facts, and in the future we may expect to see the 

laws of variation associated with transgression of the faunas clearly demonstrated. 

Enough evidence is already in sight to show that at any particular point of time, as represented by a common geological horizon or zone in a given formation, the inhabitants of one 

sea differed in species within a relatively small distance (50 miles); and within 200 miles the 

faunas may be entirely different, having not a single species in common 

The facts also give clear evidence of the shifting of the fauna with the accumulation of the 

sediments, so that the center of distribution of each fauna changes as we ascend in the formation. 

The evidence points to this shifting of the total fauna as the occasion of rapid modification and 

variation of the species, and the inference is drawn that great changes of conditions were coincident with great shiftings of the fauna. During the prevalence of a fauna in a common center 

of distribution very little evolution took place for long periods of time, as measured by thickness of sediments, but slight shifting in the geographical position of the fauna is coincident with 

the appearance of new varieties and, in general, with disturbance of the faunal equilibrium. 

The work of dissecting the contents of a fauna into its constituent faunules and then of the 

analysis of these faunules into their specific composition was begun at Ithaca, in the midst of 
DEVONIAN. 311 

the abundant Devonian fossils of the formations outcropping in that regwn. The first attempts 

to define the separate faunules and to apply names to them were imperfect on account of the 

absence then of any knowledge as to the range, distribution, and relative abundance or rarity 

of the component species. These statistics were gathered as the investigations progressed. 

Although those first attempts at classification.on the new basis are now superseded by classification based on the full appreciation of the laws of shifting of faunas, the record of the steps 

by which the progress has been made will indicate how from the study of conspicuous local 

phenomena broad general laws have been developed. 

Williams enumerates the several classifications developed for the Upper 

Devonian by the special faunal studies, and finally says: 

Revising this classification now in the light of the fuller exhibition of the facts, some of 

the distinctions made in 1885 are believed to be too refined and local for perpetuation in a general 

classification, but a few of the points then made may be adopted for general use in discussing 

the faunas of the whole continent and in comparison with the faunas of the world. 

The fauna of the typical Hamilton formation (A) may be appropriately called the Tropidoleptus carinatus fauna. That species is more characteristic of the fauna as it appears in its 

purity in the eastern New York province than is Spirijer (mucronatus) pennatus Atwater. 

The second fauna, of the Black shales (B), may be appropriately called the Lingula spatulata 

fauna, as that species is characteristic of it far and wide when in its purity, is rarely entirely 

absent, and may be found, if diligently searched for, in a typical black Devonian shale almost 

anywhere in the interior continental basin. 

The third fauna, of the Portage shales (C), may be called the Oardiola speciosa fauna. 

Although, as Hall has shown, this is not a Cardiola, as strictly interpreted, and the name Glyptocardia was proposed as a new generic name in 1885 to take its place, the fact that in Europe 

as well as in this country this generic name has been applied to this species and its European 

representative makes it not inappropriate as a name for the fauna. As Hall observed in discussing this species (Glyptocardia ( Oardiola) speciosa Hall): "It is probably identical with the 

Oardiola retrostriata (von Buch) of various authors, and with Cardium palmatum of Goldfuss. 

Its citation by numerous authors shows its wide distribution in Europe." 

The fourth fauna of the list (D)-that of the Chemung formation of the east-is the 

Spirijer disjunctus fauna. The species Spirifer disjunctus is undoubtedly identical, specifically, 

with the form which is more commonly called Spirtfer verneuili by European geologists. There 

are several varieties of it which are present in some regions in which the typical form Sp. 

disjunctus is wanting. 

Regarding the Chemung, Hall 396i said in part: 

This group consists of a highly fossiliferous series of shales and thin-bedded sandstones, 

sometimes in well-defined and distinct courses, and an infinite variety resulting from the admixture of the two ingredients. Except in a few localities, there is no very strongly marked line of 

division between this group and the one below. The distinction consists in the presence of 

numerous fossils and the coarser-grained sandstones, which are usually more impure from 

argillaceous admixture than those below. Its lithological characters, however, are variable; 

and though well marked across a single line of section from north to south, still another at a 

short distance east or west of this presents considerable variation. 

These rocks, however, can everywhere be described as a series of thin-bedded sandstones or 

flagstones with intervening shales, and frequently beds of impure limestone resulting from the 

aggregation of organic remains. The whole series weathers to a brownish olive, and even the 

deeper green of the shales assumes this hue. 

The shales vary in color from a deep black to olive and green, with every grade and mixture 

of these. The sandstones are often brownish gray or olive, and sometimes light gray. More 
312 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

generally, however, there is a tinge of green or olive pervading these strata. Toward the upper 

part of the group, in many places, there is a tendency to conglomerate; and in a few localities 

the mass becomes a well-characterized puddingstone, still retaining the fossils of the shales 

and sandstones. This conglomerate nowhere attains sufficient thickness or importance to merit 

a distinct description, but in hasty observations it may sometimes lead to erroneous inferences, 

since it resembles in many respects the distinct and well-defined conglomerate which rests upon 

this group in the western part of the State, but which is totally distinct from the same. 

Many of the shaly sandstones and shales of this group are highly micaceous, and toward 

the upper part of the whole the shales are reddish, coarse, and fissile, with much mica in small 

glimmering scales. There is also in these shales a slight change in the character of the prevailing 

organic forms. 

Two observers, Prosser and Williams, have specially studied the Chemung and 

also the earlier Devonian. Prosser 643'

644 described in great detail the sections of 

the strata in south central and eastern New York, and in his later report he 

concludes :

644a 

Succeeding the Tully limestone and Genesee slate, ()I' farther east, where these formations 

have disappeared, the Hamilton formation, is a mass of thin bluish sandstones and smooth shales 

of Portage age, for which Vanuxem proposed the name "Sherburne flagstone," which has been 

adopted and used as the name for the formation. It has a thickness of 250 feet in the Chenango 

Valley and may be readily traced westward to the meridian of Cayuga Lake, west of which 

Prof. J. M. Clarke has shown that it gradually passes into theN aples beds. Eastward from the 

Chenango Valley the Sherburne formation crosses Chenango, Otsego, and Schoharie counties, 

entering Albany County, where it turns south-southwesterly, and apparently extends to the 

Delaware River crossing Greene, Ulster, Sullivan, and Orange counties. "\'\'here the Sherburne 

formation is separated from the Hamilton by the Tully limestone and Genesee slate, fossils 

are comparatively rare in it, but to the east of the Chenango Valley, in Otsego and Schoharie 

counties, they are more common and constitute a modified Hamilton fauna. In eastern New 

York across Greene and Ulster counties the upper part of the flagstones or "North River 

blue stone" is apparently in the Sherburne formation but contains scarcely any fossils except 

occasionally a few species of plants. 

Above the Sherburne is the Ithaca formation, which has a thickness of 500 feet in the 

Chenango Valley and extends from the vicinity of Keuka Lake, where .it has been shown by 

Prof. Clarke that the "Portage or Naples fauna prevails largely to the exclusion of representatives of the Ithaca fauna,"a eastward across Schuyler, Tompkins, Cortland, Chenango, Otsego, 

and Schoharie counties. In eastern New York across Albany, Greene, Ulster, and Sullivan 

counties the physical conditions which existed during the deposition of the Oneonta and Catskill 

formations appear to have also prevailed during Ithaca time and perhaps they began in the 

Sherburne, so that there is very little evidence of the Ithaca fauna, the fossiliferous bluish and 

grayish shales of the more western counties being replaced by the unfossiliferous red and greenish 

shales and sandstones. In Orange County and northeastern Pennsylvania there is some 

representation of the Ithaca fauna, the reds appearing later as one follows this series to the 

southwest. Prof. Clarke has clearly shown that the Ithaca fauna in the Chenango Valley is 

composed of "a more abundant representation of unmodified Hamilton species" than in the 

Ithaca region,b which is also true to the east of the Chenango Valley, as demonstrated by the 

numerous lists of fossils given in this report. 

From the Chenango Valley eastward the Ithaca is capped by the Oneonta formation, which 

is composed of red and green shales, reddish sandstones, and coarse-grained grayish to greenisha Fifteenth Ann. Rept. New York State Geologist, p. 81 and "Geological map showing the distribution of the 

Portage group." 

b Idem, pp. 46-63. 
DEVONIAN. 313 

gray sandstones. These rocks are nearly unfossiliferous, containing only an occasional specimen 

of Archreopteris and Amnigenia catskillensis (Van.) Hall. The formation has a thickness of 

550 feet in the Chenango Valley and as the physical conditions under which the Oneonta was 

deposited appeared earlier to the eastward, it gradually thickens in that direction till in Albany 

ana Greene counties it completely replaces the Ithaca formation. 

The Chemung formation east of the Susquehanna River rapidly thins to the eastward on 

account of the earlier appearance of the physical conditions which prevailed during the deposition of the Catskill formation, so that the lithologic characters of the Chemung are gradually 

replaced by those of the Catskill, and as this change takes place the Chemung fauna disappears 

till the farthest east it was noted was near Spring Lake, northwest of Delhi, where a small 

Chemung faunule occurs above red shales. Search in the rocks occurring at the horizon of the 

Chemung formation east of the Delaware River was not rewarded with any fossils, and the 

lithologic appearance of these rocks is similar to that of those composing the Oneonta and 

Catskill formations. 

In eastern New York in Albany, Greene, Ulster, and Sullivan counties the physical 

conditions under which the Oneonta and Catskill formations were deposited began as early 

as Sherburne time and continued throughout the remainder of the Devonian period. The 

representation of the Ithaca or Chemung faunas is very slight and this great mass of rocks 

consists maivly of alternations of red and green shales and sandstones and gray to greenishgray coarse-grained sandstones, with some conglomerates in the Catskill Mountains. In the 

Delaware Valley the red rocks do not appear as early and there is some representation of the 

Ithaca fauna, which is more pronounced in northeastern Pennsylvania. As this series of rocks 

is followed along the Appalachians southwesterly across Pennsylvania, Maryland, and the 

Virginias it is found that the reels gradually appear later and the Chemung fauna is present. 

For in western Maryland, succeeding the black shales with a Genesee fauna at the top of 

the Hamilton, are first nearly barren smooth shales and sandstones like the Portage of western 

New York, then rougher shales and rather mealy sandstones containing an abundant Chemung 

fauna with numerous specimens of Spirifer disjunctus in Garrett County, and finally the red and 

grayish shales and sandstones of the Catskill. This change from the Catskill Mountain region to 

the southwest is found to be quite similar in general characters to the change from these mountains westward across southern New York, the story of which was excellently told some years 

ago by Prof. Stevenson in his address before the American Association for the Advancement 

of Science. a 

K-L 16-17. MICHIGAN, INDIANA, AND OHIO. 

The Michigan section of the Devonian comprises the Dundee limestone, Traverse formation, and Antrim shale. 

Lane 517 describes the divisions of the Devonian, and from his description the 

following notes have been derived. 

The Dundee limestone is a persistent stratum throughout Michigan, with a 

general thickness of 200 to 253 feet. "Beginning with a thickness of an even 100 

feet in the southeast corner of the State, it thickens slowly to Port Huron. Going 

west and north it at first thickens until it gets its full thickness of about 250 feet, 

and then begins to thin." It is nearly the equivalent of the Onondaga ("Corniferous ") limestone of New York. "It is very uniformly a high-grade limestone, 

with only a small percentage of magnesia, not infrequently over 98 per cent CaC03

, 

light colored, or brown with oily matter * * * and sometimes, not always, 

cherty." 

a The Chemung and Catskill (upper Devonian) on the eastern side of the Appalachian basin: Proc. Am. Assoc. 

Adv. Sci., vol. 40, 1892, pp. 219-248. 
314 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The relation of the Dundee to the underlying Monroe formation is one of unconformity, marked by some erosion of the uppermost Monroe. Lane 517a says: 

At the close of the Monroe the State [Michigan] was so elevated that slight folds which 

occurred at the same time could be planed off, and the underlying formation in numerous places 

from Mackinaw to Monroe County, made into a dolomite conglomerate. * * * So far 

as we know it remained above water during the opening stages of the Devonian Helderbergian. 

* * * The same disturbance that cut Michigan off once more may have opened up New 

York to the Helderbergian, so that while the Coeymans and Port Ewen beds were forming in 

New York, 300 or 400 feet in all, Michigan was mainly out of water, and not until the Schoharie 

did deposition that has been recognized by its fossils begin in Michigan. 

Grabau 382 first described the occurrence of the Schoharie fauna in the Dundee. 

Lane uses Traverse to designate a division of the Devonian of Michigan which 

overlies the Dundee and underlies the Antrim. This is a more restricted use than 

that of Grabau, 379 who employed "Traverse" to include the Dundee and Traverse 

of Lane. 

In the restricted sense Traverse is classed by Lane 517b as equivalent to Hamilton 

and Marcellus, or Erian of Clarke and Schuchert's latest classification of the New 

York section, and as the representative of the Delaware limestone of Ohio. Of it 

he says: 

As this group is much thicker and better exposed in the north end of the State and its 

very existence along the south line of the State has been doubted, we begin our description 

from the north, where it outcrops on Grand and Little Traverse bays and thence is frequently 

exposed around to Alpena and Thunder Bay, and is nearly uniform in thickness (600 feet with 

a basal shale, Bell shale, 80 feet, which corresponds to the Marcellus and is persistent throughout 

the State.) 

Following Grabau, Lane divides the Traverse as follows: 

Feet. 

Chert beds; Naples goniatite fauna at top ................ ______ . ____ . ______ ._. _____________ . 45-50 

Petoskey limestone; Stromatopora and buff magnesian ... _________________ . ____________ . _ _ _ 360 

Acervularia bods; Bryozoa beds ..... _ ...... __ ... __ ._ ... ___ .... ___ .. _ .. _ .. ___ ... ______ ... _ 110 

Bell shales ....... ___ ..... ___ .. __ ._. ___ ........... ___ ... ___ ... _. __ .. _ ...... __ ..... ___ ..... SO 

600 

The Antrim shale is described by Lane 5170 as dominantly shale, "black and 

bituminous at the bottom, then blue, and at the top, where it passes into the Berea 

grit, or the horizon thereof, red or interstratified with sandstones and gritty." It 

is regarded by Lane as equivalent to the Senecan of the New York State Survey 

classification. It may or may not include a representative of the Genesee shale, 

according to Lane. Of the Ohio divisions it is regarded by him as the equivalent 

of Huron, Chagrin, Cleveland, and Bedford formations. The thicknesses cited by 

Lane from well records range from 140+ to 480 feet. 

The passage from the Devonian to the Carboniferous in Michigan is not readily 

placed. Generally the Antrim shale has been regarded as uppermost Devonian 

and the Berea sandstone as the base of the Carboniferous. The plane at the top of 

the Antrim is not determinable, however, where the Berea is absent and the Antrim 

shale is followed by the Coldwater shale, and even where the Berea is present and the 

lithologic division can be established, the assignment of strata to Devonian or 
DEVONIAN. 315 

Carboniferous is subject to question. It has been customary to draw the line 

theoretically and so far as practicable in fact at the top of the Antrim, on paleontologic grounds. Lane 5170 says: 

In order to get consistent results and thickness one must recognize that the transition to 

the Berea grit is gradual and a great thickness of Berea grit or strata ascribed thereto is at the 

expense of the Antrim. * * * 

To put the base of the Carboniferous at the base of the Bedford we should have to split 

the Antrim in a very impracticable way, though we could readily enough follow Ulrich's suggestion and place it lower. [Lane states that Ulrich would transfer the Antrim to the Carboniferous.] It is noteworthy that just as the Sylvania is confined to the east side of the basin along 

the Cincinnati anticlinal, so is the Berea grit, and when the Berea grit does not appear, then 

the upper strata of the Antrim have a red facies like the Bedford of Ohio, or the Richmond top 

to the very similar Lorraine. This red facies is, it seems to me, very likely due to exposure to 

the weather. Where the Berea grit is well developed it is, I believe, never found. It therefore 

may indicate the uplift generally taken to mark the close of the Devonian and beginning of 

Carboniferous. 

This is the Michigan phase of the Waverly problem. (See also papers by 

Girty.36r, 363) 

In northern Ohio the Cleveland shale is regarded by Prosser 649a as the uppermost Devonian, whereas the Bedford shale is placed at the base of the Carboniferous. 

According to Lane both of these formations are represented in the Antrim shale, 

and thus, to be consistent with the Ohio scale, the line should be drawn in Michigan 

in the Antrim itself. This Lane regards as impracticable. 

Following the general usage we discuss the Berea sandstone and overlying 

formations as Carboniferous. (See pp. 420-421.) 

In 1905 Prosser o.sr published a classification of the geologic formations of Ohio, 

which has since been republished with the New York equivalents by Stauffer.789 

:{n another paper 790 Stauffer describes the Middle Devonian as follows: 

The Middle Devonian of Ohio naturally falls into three divisions, of which the lowermost 

is known as the Columbus limestone, the middle as the Delaware limestone, and the upper as 

the Olentangy shale. This division is based on both lithological and faunal differences which 

in some respects are more apparent in the vicinity of Columbus, although not wanting in any 

of the belts of the outcrop. The thickness of each of these three formations varies through a 

considerable range in different parts of the State. 

The Columbus limestone presents two rather persistent lith0logical differences which are 

excellently illustrated in the outcrops along the Scioto River and are not absent even in the 

northern sections. These two phases of the formation sometimes blend with each other, but 

occasionally localities are found where the change is abrupt and the characteristics of each 

portion decided. 

The lower portion of the Columbus limestone consists of a rather porous massive brown 

limestone, frequently containing a large a.mount of bituminous matter and very little chert, 

but generally having numerous cavities or pockets filled with crystals of calcite. At some 

places near the base it has been observed to have a pitted or honeycombed structure. It sometimes shows a strong oblique jointing and frequently few definite bedding planes .. A fresh 

surface shows a saccharoidal appearance but occasionany glistens with cleavage faces of calcite. 

There is also a tendency to a banded structure which may be seen in the blocks of most if not all 

exposures in central Ohio. This banding, frequently of a wavy appearance, seems to be due 

to the presence of finely divided bituminous matter. The fossils, except in the extreme upper 
31G INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

and lower parts, are poorly preserved and rather rare in most localities. Chemically the limestone from this part of the formation is found to be high in its percentage of magnesium. A 

sample from Dublin yielded 41.07 per cent of magnesium carbonate, while several from Bellefontaine gave even a higher percentage for this constituent. 

The upper part of the Columbus limestone, which includes about two-thirds of the formation, consists, in the main, of light-gray limestone in even beds varying from a few inches to 

several feet in thickness. At places it contains a considerable amount of white or light-gray 

fossiliferous chert, which is mainly restricted to a few zones, where it occurs in concretionary 

masses which are arranged in somewhat definite layers. The upper layers of the limestone are 

the thinner and often of a bluish color. The heavy beds, where long exposed, weather into 

rather thin irregular layers which break into angular blocks and fall to the base of the cliff, 

forming the usual talus slope. This portion of the formation always shows a crystalline or 

subcrystalline structure. It is high in its percentage of calcium carbonate, which ranges from 

81.14 to 93.28 per cent in samples taken from l\farble Cliff quar:ries. \Vhile all layers seem to 

contain abundant fossils, many are literally crowded with the remains of the various species 

which swarmed in the waters of this warm Devonian sea. 

The base of the Columbus limestone rests upon the Monroe formation, this contact being 

that between the two great systems, the Silurian and the Devonian. There is thus a great 

time gap or unconformity between these two formations, which is strikingly illustrated by the 

decided change in character and abundance of animal remains. In some localities the lowest 

layers of the Columbus contain an abundant fauna which in many respects resembles that of 

the upper part of the same formation, but where these lower layers have been observed in 

Franklin, Delaware, and Union counties a basal conglomerate is found which consists of large 

and small waterworn pebbles of the underlying formation embedded in a matrix of Columbus 

limestone. ·where this conglomerate is developed few fossils are found, probably because the 

organic remains which existed in these localities at the time the layers in question were being 

deposited were ground to a shapeless mud by the continuous action of the waves among the 

pebbles of a rocky coast. This conglomerate was formerly supposed to represent the Oriskany 

sandstone of New York and was so mapped by the geologists who made the first county reports, 

as well as by Newberry himself; but since tlris basal conglomerate is not continuous and has 

not been proved to be Oriskany, it has been customary of later years, and perhaps wisely, to 

drop the Oriskany sandstone from the Ohio scale and include these deposits with the Columbus 

limestone, to which they are at least very closely related. 

The upper limit of the Columbus is no less interesting, since it terminates in the famous 

"bone bed" first described by Orton. This layer or bed comprises the upper 6 or 8 inches of 

the formation and is frequently made up of an ''assemblage of millions on nrillions of generally 

imperfect but mostly recognizable organs or fragments of the bony structure of the forms of 

fish life most characteristic of the Devonian age." These teeth and dermal plates are often in 

an excellent state of preservation, retaining even their original luster. Contrary to what has 

usually been supposed, this limiting layer of the formation may be traced northward to Sandusky, where it has proved of invaluable assistance in determining the line of division between 

the Columbus and Delaware limestones. 

The Delaware limestone extends from the "bone bed" upward through a thickness of 

about 36 feet to its contact with the Olentangy shale. It is extremely variable in its appearance, consisting sometimes of thin shaly layers, beds of chert, and 'fairly massive limestone 

and again almost entirely of rather massive limestone with very little chert and no shale. 

Usually it has a deep-blue to sbte color, which becomes brown on weathering. The chert 

which it contains is mostly black and nonfossiliferous, but in sections where little occurs it is 

often a light bluish white or even pure white and somewhat fossiliferous. In general the Delaware limestone is less fossiliferous than the upper part of the Columbus, but its fauna is by no 

means small, and frequently layers are found which are very fossiliferous. The variable chemical 

composition of this formation is easily seen by a reference to the analysis of various samples 

collected at different localities. 
DEVONIAN. 317 

The Olentangy shale extends from the top of the Delaware limestone to the base of the 

Ohio shale, a vertical distance of about 31 feet in Franklin County. It has been found to be 

almost invariably present in the central strip from Sandusky southward. In Pickaway County, 

where the Devonian limestones last appear, this shale occurs, and from thence southward 

overlaps on the older rocks until at Bainbridge it rests on Niagaran limestones. The Devonian 

shales cross the Ohio River at Vanceburg, and even near Fox Springs, Fleming County, Ky., 

the basal shale has the appearance of the Olentangy. As seen in the river bank at Delaware, 

the Olentangy is a soft bluish shale, with numerous disklike argillaceous limestone concretions 

near the basal portion and layers of impure limestone in the middle and upper portions. The 

formation contains few fossils in central Ohio but becomes quite fossiliferous in the Sandusky 

region, where it includes a limestone member at the top, which has been known as the Prout 

limestone. The thickness of the formation is there also greatly increased. 

Stauffer 788 states that the Columbus limestone is the equivalent of the Dundee 

limestone of Michigan and the Jeffersonville limestone of Indiana, which are represented in New York by the Onondaga. He places the Delaware limestone of Ohio 

as equivalent to the Marcellus and correlates the formations of Michigan, Ohio, 

and New York thus: 

Michigan. 

Traverse group. 

Dundee limestone. 

Ohio. 

{

Olentang:v shale. 

Delaware hmestone. 

Columbus limestone. 

New York. 

{

Hamilton beds. 

Marcellus shale. 

Onondaga limestone. 

Devonian strata outcrop in three widely separated areas in Indiana-on the 

Wabash, near Pendleton, and in southern Indiana. The intervening stretches are 

completely covered by drift. In all sections showing the lower and upper limits 

of the Devonian in the State the base rests upon Silurian limestones and the top is 

overlain by Mississippian strata. Kindle 494a gives the formations present in the 

northern, central, nnd southern sections and states the correlation with the New 

York Devonian as follows: 

Southern Indiana area. 

New Albany shale. 

Sellersburg beds. 

Jefferson ville limestone. 

Geneva limestone. 

Devonian formations in Indiana. 

Pendleton area. 

Drift covered. 

(?) 

Pendleton sandstone. 

IV abash area. 

New Albany shale. 

Sellersburg beds. 

Jeffersonville limestone. 

\Vhen the :first attempts were made to determine the age of the New Albany shale, its 

known fauna was limited to one or two species of Lingula. Since the discovery of the Lexington fossils by Borden in 1874 a the formation has been correlated with the Genesee of the 

New York scale. The discovery by the writer of a new fauna in the New Albany shale at 

Delphi throws some additional light on the difficult problem of the true position of this formation in the time scale. Associated with several species which are new or undetermined, we 

:find in this fauna Spathiocaris emersoni, a well-known representative of the Naples fauna of 

New York. This fossil is not known in the Genesee in the New York sections hut occurs in the 

Portage and even as high as the Lower Chemung.'' 

a Geol. Survey Indiana, 1874, pp. 112-134. 

bClarke, J. M., Bull. U.S. Geol. Survey No. 16, 188.5, p. 47. 
318 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Of the species which have been previously known in the New Albany shale at least three 

are characteristic Genesee species; one is common to the Portage and the Genesee. The 

presence in the New Albany shale of a Genesee fauna and a Portage fauna seems to justify the 

conclusion that this formation is the western representative of both the Genesee and the Portage. 

The Styliola fissurella fauna does not bear any stronger evidence of the Genesee age of the 

New Albany shale than does the Spathiocaris emersoni fauna of its Portage age; these two 

faunas, however, are not intermingled in the New Albany shale. While there is no evidence 

that either one occupies a higher stratigraphic horizon than the other, they are found in unlike 

sediments. The Styliolafissurella fauna is confined to the fissile black shale, while the Spathiocaris emersoni occurs in a soft drab shale which is interbedded with the black shale in northern 

Indiana. The New Albany shale of northern Indiana contains in its fissile black strata and 

its drab sandy beds the lithologic elements of both the Genesee and the Portage, but neither 

these beds nor the elements of the Genesee and Portage faunas which they contain are sharply 

differentiated, as they arc in the eastern Devonian province. 

The problem of the correlation of the Devonian limestones with the New York scale is 

much more difficult for some parts of the Indiana province than for others. In the vicinity of 

the Falls of the Ohio we find two quite distinct and well-marked faunas. These are the Spirifer 

granulosus and the Spirifer acuminatus faunas and represent respectively the Hamilton and 

Corniferous faunas of New York. Near the Falls of the Ohio the Sellersburg beds and the 

Jeffersonville limestone which carry these faunas are sharply differentiated lithologically, the 

Jeffersonville limestone being a nearly pure limestone and representing clear-water conditions 

during its deposition, while the Sellersburg beds are composed of an impure argillaceous limestone. 

In the northern part of the southern Indiana area these two formations cease to be sharply 

differentiated lithologically and merge into each other in a limestone which is neither so pure 

as the Jeffersonville limestone nor so argillaceous as the Sellersburg beds near the Falls. Associated with the loss of individuality of these two formatioll'S occurs a mingling of their two 

faunas which renders them indistinguishable as separate faunas. 

In the 'V abash area the faunas of the Devonian limestone are even more distinct than at 

the Falls of the Ohio. In the lower one Spirifer acuminatus is an abundant fossil and the fauna 

does not differ greatly from that in the Jeffersonville limestone at the Falls of the Ohio. The 

upper fauna is a distinctly Hamilton fauna, but entirely different from the Hamilton fauna of 

southern Indiana. Two of the most abundant fossils in it are Spirifer pennatus and Chonetes 

manitobiensis. Neither of these species is known in the southern Indiana area. 

Hopkins and Foerste 46:

3 follow Kindle's classification, with additional local 

distinctions, and give the following description of the strata: 

In southern Indiana the New Albany black shale is exposed over considerable areas. It 

is a black to blue-gray fissile shale containing much iron sulphide and a great deal of bituminous 

matter. The bituminous matter is so plentiful in places that it will burn freely and the volatile 

gases have been distilled from it. The shale is 104 feet thick at New Albany, and elsewhere it 

has been reported as much as 140 feet in thickness. The outcrop covers an area from 8 to 15 

miles wide, as shown on the map. 

The Sellersburg limestone of Kindle includes both the crinoidal and the hydraulic limestones, but Siebenthal limits the term Sellersburg to the upper or crinoidal division and the 

lower hydraulic limestone he calls the Silver Creek hydraulic limestone. The Sellersburg limestone is a white to gray crystalline limestone that lies between the overlying black shale and 

the underlying hydraulic limestone. Frequently the basal portions are sandy and sometimes 

there is a layer of pebbly sandstone separating it from the underlying hydraulic limestone. 

The shining black pebbles are said to be rich in phosphates. 

The Silver Creek hydraulic limestone lies between the overlying Sellersburg limestone and 

the underlying Jeffersonville limestone. It is a fine-grained, massively bedded argillaceous 

magnesian limestone, light to dark drab in color, becoming buff on exposure. It is 15 to 16 feet 

thick at Silver Creek, 8 to 10 feet at Charlestown, and 5 to 6 feet in the vicinity of I~exington. 
DEVONIAX, 319 

The Jeffersonville limestone is a white to bluish-gray crystalline fossiliferous flaggy limestone, lying between the Silver Creek hydraulic limestone and the underlying Niagara limestone. 

It has been correlated with the Corniferous of New York. It is exposed at the Falls of the 

Ohio River, and from it are obtained many fine coral fossils. In this part of the area there 

was a great coral reef, not greatly unlike many forming at the present time, except the corals 

are a different class from the living ones. 

The irregular contact representing the unconformity between the Devonian and 

underlying Silurian has been recognized locally. Kindle has noted it at a point 35 

miles south of Indianapolis and in northern Indiana; farther south, according to 

Kindle, 494 physical evidence of this unconformity between the Devonian and 

Silurian has not been observed. Along their contact north of Indianapolis later 

Devonian strata overlap northwestward beyond earlier strata, indicating the 

gradual submergence of the Wisconsin-Illinois peninsula; and a similar relation is 

noted on both sides of the Cincinnati arch in Indiana and Ohio. 

The Devonian of Ohio. (Columbus limestone to Ohio shale, inclusive) comprises the equivalents of the New York section from the Onondaga (" Corniferous ") 

limestone to the somewhat indefinite horizon where the Devonian passes into the 

Carboniferous. 

L 12. SOUTHWESTERN MONTANA. 

The type section of the Paleozoic of southwestern Montana is that of Threeforks, 

near latitude 46°, longitude 111° 30', originally described by Peale. It includes 

the Jefferson limestone and Threeforks shale, which lie between the recognized 

Cambrian and lower Carboniferous strata. 

The Jefferson limestone and Threeforks shale were first described by Peale 631 , 632 

as representing the Devonian and possibly including some Silurian at the base and 

some Carboniferous at the top. Peale states the occurrence of pebbly limestones 

of Upper Cambrian or Lower Ordovician age, and in the ~olio text says: 632 a 

DEVONO-SILURIAN. 

The pebbly limestones pass imperceptibly into a series of black magnesian limestones 

which for several hundred feet are, so far as examined, devoid of fossils. It is possible, as the 

pebbly limestones have every indication of being on or near the border line between the Cambrian and the Silurian [Ordovician], that their upper beds and a part of the overlying bhck 

limestones may eventually be referred to the Silurian [Ordovician and Silurian]. There is little 

doubt that the sedimentation was continuous, and we need not be surprised if sometime in the 

future this now barren interval should somewhere furnish a mingling of Silurian and Devonian 

forms. 

DEVONIAN. 

The black limestones referred to under the head of Devono-Silurian have been provisionally 

referred to the Jefferson formation, because the fragments of fossils found in the middle and 

upper part, although few and very indistinct, were recognized to be the same as those occurring 

in the Threeforks shales, which are, without much doubt, Devonian. The total thickness 

referred to the Devonian is about 870 feet. 

The Jefferson limestone forms the base of the formation, consisting of several hundred feet 

of black or mud-colored limestone, which is generally crystalline and magnesian from top to 

bottom. It is well exposed in all parts of the Threeforks region and at most localities is nonfossiliferous, only a few forms having been obtained from near the top of the formation, and 

these only in the region north of the East Gallatin River. 
320 INDEX 'fO THE STRATIGRAPHY OF NORTH AMERICA. 

Tho Threeforks shales, which rest conformably upon the Jefferson limestone, may be 

divided into throe parts-the lower or orange-colored shales, about 50 feet in thickness; a band 

of grayish-brown argillaceous limestone, 20 feet thick; and the upper green, black, and argillaceous shales, some 50 feet in thickness, which are crowded with Devonian fossils and capped 

by a band of yellow laminated sandstone 25 feet thick. These Devonian fossils were found 

both in the northern and in the southern portion of the district, and doubtless occur wherever 

the beds are found. A coal-black slate is seen near the upper part of the shales in the vicinity 

of the head of the Missouri River. In the Jefferson Canyon this has developed into a bed of 

coal, in which are found limestone nodules containing the same Devonian forms that are elsewhere found in the shales. The shales are near the border line of the Devonian and Carboniferous, and their organic remains contain a mingling of forms of both, but the preponderance 

of evidence is in favor of their Devonian age. 

On examining fossils collected in course of the survey of Yellowstone Park, 

Girty 393c confirmed the determination of the Devonian age of the Threeforks shale 

and noted the relation of the fauna to the Devonian of the White Pine district, 

Nevada. Fuller collections have been made by Kindle 499 in a special study of the 

Jefferson limestone and by Raymond 662 from the Threeforks shale. Kindle concludes that the Jefferson is "earlier than Upper Devonian" and probably includes 

both Lower and Middle Devonian. Raymond describes the fauna of the Threeforks 

shale as Upper Devonian. 

Kindle says, in part: 

The Jefferson limestone has a wide distribution in the northern Rocky Mountain region. 

In Montana its distribution seems generally to coincide with that of the Madison limestone, 

which immediately follows it in the sections where the highest formation of the Devonian system 

is absent. Its distinctive composition and color have enabled geologists to identify the Jefferson 

limestone over a rather wide area in Montana and northwestern Wyoming. The writer has 

recognized the formation still farther south in western Wyoming and northeastern Utah. 

[Details follow.] 

The evidence now at hand indicates that the eastern edge of the formation lies somewhere 

near the one hundred and ·ninth parallel in the States of Montana, Wyoming, and northern 

Utah. What its southern and western limits may be remains to be determined. The formation has a known east-west extent of about 150 miles in Montana and a north-south extent of 

about 425 miles. Its actual extent is probably much greater. The paleontologic evidence of 

the identity of this formation with the Nevada limestone of Nevada is presented elsewhere in 

this paper. 

Sections in Montana._.:Some of the stratigraphic evidence on which the extent of the 

Jefferson limestone as outlined above is based may be shown by consideration of a few 

typical sections which include this formation and exhibit its relations. The section at 

Threeforks, ~1ont., the type locality of the Jefferson, as given by Peale, is as follows: 
DEVONIAN. 

Section at Threejorks, Mont. 

J aspery limestones .... _ 

Massive limestones ..... _ ......... . 

Carboniferous: Madison limestone. ______________ . ______ Laminated limestones ............. . 

Feet. 

575 

350 

325 

1,250 

[Upper shale....................... 70 

!

Limestone bed shown in section. 

Devonian: Threeforks shales .......................... Lower shales.-------·--------------

1

:: 

Silurian(?) [Devonian of Kindle]: Jefferson limestones ... Black limestones.................. 640 

Pe"f?bly limestones................ 145 

Dry Creek shales.................. 30 

Mottled limestones. . . . . . . . . . . . . . . . 260 

Cambrian: Gallatin formation .......... ---------------. Obolella shales. _______ .____________ 280 

* * * * * 

Trilobite limestone................ 120 

* * * 

835 

* 

321 

The Threeforks shales appear to have a much more limited distribution than the Jefferson 

limestone. They are present, however, in the Melrose section, on Camp Creek, some 30 miles 

west of Threeforks. The following section is seen along Camp Creek: 

Section on Camp Creek, Mont. 

Feet. 

K. Gray nonmagnesian limestone (Madison limestone) ................................. _ . . . . 300-t 

J. Bluish-gray argillaceous shale, huffish shale in lower part, with limestone bands near middle 

(Threeforks shale) .............................. _ ........... _ ....... ____ .... _ ...... _ 200± 

L Black magnesian limestone, with minor beds of gray limestone distributed through the 

series (Jefferson limestone) ............. ___ ...... _ ................... __ ...... __ ..... _ 500± 

H. Buff-gray hard magnesian limestone, with some shaly bands .................. _ ....... _. 30 

G. Buffish-gray nonmagnesian limestone, l-inch to 3-inch lamin1e, separated by thin bands of 

shale ........................ _ ........ _. _ ................. _ ...................... _ _ 35 

F. Dark-red sandy shales ............. _ ......... _ ................... _ .................... _ 20 

E. Light-gray magnesian limestone, with some dark bands in lower half .................... 500± 

D. Shale ......... ·_ ...................................................................... 100 

C. Shale and thin-bedded brownish sandstone .......................................... __ . 50 

B. Gray shale .................................................. _ ........................ 40 

A. Quartzite weathering brownish buff ............................................... _... 65 

The Jefferson limestone seems to reach its maximum thickness in the western part of the 

State. In the Philipsburg [quadrangle] nearly 1,000 feet of the Paleozoic section is represented 

by the dark limestones of the Jefferson formation. The following section indicates the relationship of these beds in this region, as seen along Boulder Creek, west of Princeton: 

Section along Boulder Creek, Philipsburg quadrangle, Mont. • Feet. 

E. Dark-gray to white heavy-bedded and flaggy limestone, shaly toward the base (Madison 

limestone) ................................................ __ ....... _ ............. __ 500+ 

D. Gray to black limestone in alternating beds, the latter predominating and distinctly magnesian, generally with saccharoidal texture (Jefferson limestone) ........................ _ 800 

C. Gray to brownish shale and sandstone; the latter predominates at the base ... __ ......... _ 210 

B. Bluish-gray limestone, with thin siliceous, argillaceous, and shale films at intervals of 1 inch 

to 3 inches. These intermediate lamin1e weather brownish and show in relief thin, flat, 

pebble-like concretionary (?) sheets ...................................... _ ..... ______ 275 

A. Light-gray to cream-colored hard magnesian limestone ..................... ___ .... ______ 300 

This section differs from the two preceding sections in the absence of the Threeforks shale, 

which seems to be everywhere wanting in the Philipsburg quadrangle.a 

* * * * * * * * * ------------- ---- ---·--------- -------

a For list of fossils see the work cited.-B. W. 
322 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Other sections in southwestern Montana might be given which would present the same 

general sequence with reference to the Jefferson limestone. All the sections show a limestone 

series in which dark to nearly black limestones predominate, followed by the Madison limestone, which is locally separated from the JefTerson by the Threeforks formation. The Jefferson 

in all the Montana sections is preceded by limestones and shales in which the latest observed 

faunas are of Camb_rian age. 

Sections in Wyoming.-The Montana sections show a close correspondence in these characteristic features to the southwestern Wyoming section, which follows. This section occurs 

in the westward-dipping beds of Labarge }[ountain, northeast of Viola post office and west 

of the Sayles coal r.1ine. 

Sect'ion northeast of Viola, Wyo. 

J. Light to dark-gray limestone, oolitic,in lower 20 feet (.Madison limestone) ............. . 

I. Drab shales and shaly thin-bedded magnesian and siliceous limestone ................ . 

Feet. 

500± 

80 

H. Buff to gray limestone with much black magnesian limestone in the upper part, saccharoidal in texture, and weathering with roughly pitted surface; covered in part (Jefferson limestone) .................................................................... 1, 000± 

G. Gray limestone, partly covered..................................................... 700± 

F. Gray limestone, with Cambrian trilobites abundant................................... 40 

E. Green shale and covered............................................................ 300± 

D. Drab shale and covered. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 

C. Thin-bedded gray limestone, with Cambrian trilobites abundant....................... 10 

B. Drab shale, mostly covered......................................................... 100 

A. Lead-gray limestone, checked by innumerable small joints, which are generally calcite 

filled. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 

In this section the gray and black limestone series is preceded by beds holding a Cambrian 

fauna and followed by a limestone holding the usual Madison limestone fauna. The shale formation (I) at tho top of the magnesian limestone formation appears to occupy the position of 

the Threeforks shale, but it is barron of fossils. Composition, texture, manner of weathering, 

and relationship to the section all indicate that the magnesian limestone series of the section 

is the same formation as the Jefferson limestone of the Montana sections. 

The Jciierson limestone of the Labarge Mountain section is nearly barren of fossils. The 

only fossils obtained in it were Zaphrentis and fragments of another undetermined coral. 

* * * * * * * * 

Devonian rocks in Idaho.-The only data we have relating to the Devonian in Idaho are 

based on a small collection of fossils made by Mr. F. B. Weeks during the summer of 1907. 

This collection was procured from a dark limestone "in southeastern Idaho, east of Manson 

station, Oregon Short Line Railroad." The three species represented in the collection are 

Atrypa reticuiaris, Productella cf. subaculeata, and Spirifer disjunctus cf. var. animasensis. The 

first species is the most abundant in the fauna. The presence of Sp. disjunctus seems to indicate an Upper Devonian horizon. The fauna is not sufficient to show whether or not the Jefferson limestone is represented by it. Probably, however, it is from this formation. The 

appearance of the rock, which is dark, somewhat magnesian limestone, is highly suggestive of 

the Jefferson limestone. The evidence of the small fauna, though inconclusive, points to the 

Jefferson limestone rather than to the Threeforks shale as its source. 

About 60 miles southeast of this locality, in northeastern Utah, the Jefferson limestone is 

well developed. 

Sections in Utah.-Field studies in Utah were limited to the northern part of the Wasatch 

Mountains. Numerous excellent sections of the Paleozoic are exposed by the deep canyons east 

of Cache Valley. The canyons cut at right angles the general trend of the structure, which is 

of the moderately folded type, few of the heavier dips exceeding 30°. Nearly vertical cliffs 

2,000 feet or more in height alternate with slopes of every degree of inclination along the sides 

of the canyons. * * * 

Examination of half a dozen of the canyon sections to the south of Logan Canyon has 

shown that the Carboniferous and Devonian portions of the section may be distinguished both 

by physical and faunal characters. In the Devonian series, generally 1,000 to 1,200 feet thick, 
DEVONIAN. 323 

dark magnesian limestones are the predominant element, although nonmagnesian limestones 

and in some places argillaceous rocks appear as minor components of the formation. In the 

Carboniferous the dark magnesian limestones of the lower series are replaced by lighter-colored 

nonmagnesian limestones. The Carboniferous and Devonian series of these sections show about 

the same kind and degree of contrast which is found between these series in the Montana section. The Devonian beds of these northern Utah sections appear without question to be the 

southern continuation of the Jefferson limestone. The following is a representative section 

occurring nearly cast of Paradise post office, in Green Canyon: 

Section in Green Canyon, Utah. 

D. Gray nonmagnesian limestone, partly covered ...................................... . 

C. Dark-gray to black magnesian limestone, generally with saccharoidal texture ......... . 

B. Thin-bedded limestone, buff or brownish near top, with peculiar concretionary developmont, with thin-bedded bluish-gray limestone in lower part. ...................... . 

A. White to light-gray magnesian limestone, with chert or siliceous beds locally developed 

[Silurian, Kindle] ............................................................... . 

Feet. 

900± 

1,100± 

100 

150 

---

2,250 

Kindle mentions the contrast between the Jefferson fauna and that of the Ouray 

limestone of Colorado, and also comments on the close equivalency of the Jefferson 

limestone of Montana, Wyoming, etc., and the Nevada limestone of Nevada and their 

faunas. He says in part: 

The fauna of the Jefferson limestone as known at present is a small one, numbering about 

32 species. Like many other western faunas, it includes very few species which are common to 

the standard sections east of the :Mississippi. Of the five species which are common to the wellknown eastern sections all except Atrypa reticularis arc characteristic Devonian species, a 

sufficient number to make evident the Devonian age of the fauna. * * * 

In attempting to determine just what part of the Devonian is represented by the fauna 

of the Jefferson limestone we find that two of the five species which are common to the Jefferson 

limestone fauna and the eastern Devonian fauna are Atrypas. One of these, A. reticularis, has 

no diagnostic value, while A. spinosa has a recorded range from the Corniferous to the Chemung. 

The other three species, Schuchertella chemungensis arctostriatus, Productella spinulicosta, and 

j,fartinia maja, are known in the eastern sections only in Middle Devonian horizons. The 

absence from the fauna of any of the large Productellas, which generally characterize the late 

Devonian faunas, together with the presence of an Upper Devonian fauna following it in the 

section, both supplement the intrinsic evidence of the fauna that it is earlier than Upper Devonian. The known range of the fossils which are common to eastern sections suggests a Middle 

Devonian age for at least a part of the Jefferson limestone. The fauna contains no coarsely 

plicated Spirifers or other fossils generally characteristic of the early Devonian, but other 

evidence strongly supports the view that the Jefferson limestone represents both Lower and 

Middle Devonian. 

No evidence of a stratigraphic break between the Jefferson and the preceding formation 

has been observed by the writer in any of the sections examined by him. None of the folios 

which describe the Jefferson limestone record any unconformity at its base. * * * In 

Utah the writer has found conditions that seem to indicate there the continuity of sedimentation 

from the Silurian to the Devonian, which, although probable in :Montana, has not been demonstrated. * * * 

The fauna of the Threeforks shale, which immediately follows the Jefferson limestone in 

some of the sections in :Montana, is composed for the most part of alien species. Dr. Raymond's 

list of the Threeforks shale fauna at Logan and Threeforks, :Mont., showed but three species 

which are known in the Jefferson limestone. Evidently very few of the indigenous species of 

the Jefferson limestone survived the conditions which inaugurated the deposition of the shales 

that terminated the Devonian in this region. 
324 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Raymond's notes on the Threeforks shale refer to the type locality in southwestern Montana. He says in part :

662 

It is the purpose of the present paper to announce the discovery in the Threeforks shales, 

near Threeforks, Madison County, Mont., of an Upper Devonian fauna containing Clymenia, 

Entomis, and goniatites. 

* * * * * * * * * 

The Threeforks shales were divided by Dr. Peale into three portions: 

Feet. 

3. Upper shales, with many fossils.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 

2. Grayish-brown limestone, without fossils ............................................... 15-20 

1. Lower shales, without fossils. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 

Division 3 is subdivided as follows: 

Feet. 

D. Yellow sandstone, the lower part calcareous........................................... 25 

C. Coal-black shale...................................................................... 5 

B. Gray limestone....................................................................... 10 

A. Green shales with bands of limestone................................................. 30 

* * * * * * * * * 

In the 65 feet of strata constituting the upper shales at Threeforks there are five zones in 

which the lithology and faunules differ somewhat. 1, 2, and 3 make up A above; 4 is the same 

as B; and 5 equals D. From C no fossils were obtained. These zones, beginning with the 

lowest, are as follows: 

1. Red shale zone.-The shales of this zone are hard, reddish, and fissile, the layers weathering into small, sharp-pointed fragments. The fossils are preserved in pyrite, which is often 

partially altered to limonite, and they weather out on the surface in numerous bare spots along 

the strike of the beds. * * * 

2. Green shale zone.-These are the green shales described by Peale (part of A, above). 

Fossils abound and further collecting should reveal a much larger fauna. Clymenia and Entomis 

are abundant, associated with a great number of brachiopods and lamellibranchs. * * * 

3. White blocky shale.-The exact horizon of this zone is not known, as the fossils were 

obtained at a locality where the layers seemed to be somewhat disturbed. In the field it 

appeared to be above the green shale, but it could not be located in any place where the beds 

were undisturbed. The faunal list is short, but the fossils are abundant. * * * 

4. Gray limestone zone.-This limestone weathers readily and produces great quantities 

of fine fossils, mostly brachiopods. Two species of Clymenia occur in this zone, but the goniatites are very rare. This same limestone is well exposed in the Devonian ravine at Logan, but 

no specimens of Clymenia were found at that locality; it has, however, furnished two fragments 

of cups of crinoids, one of which has been identified as a species of Mariacrinus, by Mr. Frank 

Springer. This is of interest, as it is the first crinoid reported from the Devonian of the Rocky 

Mountains. * * * This seems to be the upper limit of the range of Clymenia. 

5. Yellow sandstone zone.-This sandstone or sandy limestone forms the capping bed of 

the Devonian both at Threeforks and at Logan. A few beds are very fossiliferous and the 

fauna indicates a transition into the Mississippian (Madison limestone).a 

L 18. ST. HELENS ISLAND, MONTREAL. 

A very small exposure of Devonian agglomerate on St. Helens Island, Montreal, 

has yielded Devonian fossils that appear to present a unique association. Schuchert 713 

reviewed the faunas and the conditions of their occurrence and concluded: 

The foregoing evidence shows clearly that two distinct faunas are represented on St. Helens 

Island-one, the Helderbergian, older than the agglomerate, and another, from a block in the 

agglomerate, of Middle Devonic age. 

a For lists of fossils from the several zones see the work cited.-13. \\". 
DEVONIAN. 325 

The Helderbergian fauna is apparently related with that of New York, and belongs to the 

facies occurring on the western side of the Appalachian folds. The writer has collected this 

fauna at Dalhousie, New Brunswick, and from the Gaspe region, Quebec, and both are of 

another facies and belong to another basin. 

The presence of Rhipidomella recalling R. musculosa,· Spirifer concinnus,· an early variety 

of S. murchisoni,· Spirifer n. sp., connecting phylogenetically S. concinnus and S. arenosus,· 

Camarotmchia pleiopleura,· Gypidula pseudogaleata; and Rensselaeria acg_uiradiata shows that 

the St. Helens Island Helderbergian is not as old as the New Scotland zone. Spirifer concinnus 

and especially G. pseudogaleata and R. acg_uiradiata are characteristic Becraft zonal species. 

However, the Oriskanian reminders, like R. near musculosa, S. murchison, S. near arenosus, 

prove that the St. Helens Island Helderbergian is pretty well up toward the top of the New 

York section, and may represent both the Becraft and Kingston zones. 

Spirifer macra and S. granulosus establish the fact that, in the region of Montreal, there 

was once a formation of marine origin later than the Helderbergian and as recent as the Onondaga (Corniferous); further, that the agglomerate of St. Helens Island and other places about 

Montreal is not older than late Middle Devonic time. Its age is probably more recent, and 

there may be further paleontologic evidence in the agglomerate. 

L 18-19. QUEBEC, SOUTHEASTERN TOWNSHIPS. 

Ells 313 states that "areas of Devonian rocks occur at several widely separated 

points in the area east of the Sutton Mountain anticline and its extension northward." Small outliers are known on the Chaudiere. "While detached areas of 

Silurian (Lower Helderberg) occur at a number of places between the Chaudiere 

and the United States boundary, to the southwest, the only outcrops of strata 

holding typical Devonian fossils are found on the western shore of Memphremagog 

Lake." These rocks had been previously described by Logan and Billings and 

had been assigned to the "Corniferous" horizon by Dana and by Ells. They are 

plumbaginous limestones, underlain by somewhat dolomitic flaggy slates and shales, 

which Ells describes as resting upon fossiliferous "Silurian" strata [Devonian 

Helderberg limestone]. They are penetrated by intrusive dikes. With reference 

to the relations of these Devonian rocks to the Silurian and to the Devonian of the 

Gaspe Peninsula, Ells 313a states: 

No well-defined break between the upper Silurian (Lower Helderberg) and the overlying 

Devonian has been found, the conditions of deposition presumably being similar to those in the 

Beauce [Chaudiere] district or in the similar beds of the Gaspe Peninsula, described under the 

head of the Gaspe Limestone series in the "Geology of Canada," as well as in subsequent 

reports.a In all these localities there appears to be a mingling of forms of upper Silurian and 

lower Devonian horizons, in so much that it has been found very difficult, and in some cases 

impossible, to define the exact line of separation between the two systems. 

L 19. SOUTHERN NEW BRUNSWICK AND EASTERN MAINE. 

In southern New Brunswick Devonian rocks occur in two areas-one in Charlotte 

County south of the Carboniferous basin, the other in St. John County, consisting of 

the Mispec and Lepreau basins. The rocks of the latter area extend across the 

international boundary and occupy the Perry Basin in eastern Maine. 

The belt which is mapped as Devonian in Charlotte and Queens counties south 

of the Carboniferous basin was thus described in 1880: 49 

The largest area of rocks of this age is that occurring in the northern part of Charlotte 

County and extending eastward into Queens County. These rocks have been described in the 

a Geology of Canada, 1863, pp. 406-428; Rept. Progress, Geol. Survey Canada, 1880-82, pp. 3-16DD. 
326 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

report of 1870-71, and are also briefly mentioned in the report of 1876-77. They comprise 

the former so-called pale argillite group. They are superimposed upon Cambro-Silurian rocks 

and extend from the St. Croix River, near Spragues Falls, to the Charlotte County line and 

thence into York. At the line of contact the dips are nearly vertical, but there is in places an 

apparent conformability betwe<m the dark argillite portion of the Cambro-Silurian and the 

series under discussion. It is probable, however, that faults occur at the line of contact, as the 

beds of fossiliferous Silurian so well developed about Oak Bay, on the south sido of the CambroSilurian belt, are entirely wanting along the northern margin. The Devonian age of these rocks 

has been based by Mr. Matthew upon the occurrence of remains of Lepidodendron, * * * 

as well as from certain graphitic films, supposed to be the impression of fern leaves, found in 

the eastern extension of these beds into Queens County. They also possess many points of 

resemblance, lithologically, to the typical Devonian Mispec, and hence they have provisionally 

been assigned to this horizon. 

Doubt is cast upon the Devonian age of these rocks, as the Mispec group is 

now known to be meso-Carboniferous. 22a (Seep. 331.) 

The Devonian rocks of the St. John-Lepreau-Perry area have been the subject 

of much discussion as to their true age and have been considered Carboniferous on 

account of lithologic resemblances. The latest contribution from the Canadian 

Survey is by Ells, 315 as follows: 

One of the most interesting of the geological formations which occur in this portion of New 

Brunswick is that known as the Perry sandstone group. * * * The rocks consist of conglomerates, sandstones, and shales, generally reddish in color, but occasionally, in the lower 

portion, some of the heavier sandstones and conglomerates become grayish. Plant stems are 

quite abundant in some of the shale beds, both in the rocks of Perry and near St. Andrews. 

These were carefully studied many years ago by Sir William Dawson and several papers relating 

to their character and age were published by him between 1861 and 1870, in which their horizon 

was placed as the upper portion of the Devonian system. The same conclusion had been 

reached at an earlier date by Dr. Jackson and adopted by Prof. Rogers, after an examination 

of the material from the plant beds of Perry, Maine. 

In the report by Bailey and Matthew, 1870-71, the opinion is expressed that the rocks of this 

group are referable to the base of the Lower Carboniferous, rather than to the Devonian, from a 

supposed lithological resemblance to certain conglomerates which are found in Kennebeccasis 

Bay, an arm of the St. John River, where these rocks are assigned to the Carboniferous horizon. 

In Charlotte County the Perry group can be well studied in the peninsulaextending from 

the base of the Chamcook Mountain to the point at St. Andrews where the exposures are practically continuous for a distance of about 5 miles. The beds are cut across by several dikes 

of green diabase which have altered the sediments at their contact. Similar dikes arc seen on 

Minister's Island to the east. 

The lowest beds of the group at Chamcook Mountain consist of a coarse, heavy conglomerate 

with pebbles, often of large size, for the most part derived from the felsitic rock of which the 

mountain is composed. These conglomerates are a conspicuous feature in many places at the 

base of this series of rocks, and they also occur occasionally as intermediate beds higher up in 

the series. They are well exposed in the bluff east of Chamcook Harbor, on tho islands and on 

the shore at the entrance to Digdeguash Harbor and further east on Bliss Island, I/Etang 

Head, and Pea Point, and again around the shores of Lepreau Harbor, which is the extreme 

eastern part of the county. 

The dip of the strata in the St. Andrews Peninsula is uniformly to the south or southeast, 

at angles from 10° to 25°. At an average inclination of 15° over a distance of 5 miles, since 

the southern margin of the basin is not here reached, the thickness for the beds at this place 

will not be far from 7,000 feet. No well-defined faults or repetitions of the strata are seen in 

this section. This estimate of thickness far exceeds that hitherto made for any portion of 

the lower Carboniferous as developed in southern New Brunswick. 

* * * * * * * * * 
DEVONIAN. 327 

The outlines of this formation were carefully traced along the shores from the St. Croix 

River to Point Lepreau, and in some places, as at Pea Point, and L'Etang Head, the basal 

conglomerate was found to have a great thickness, aggregating not far from 4,000 feet. At 

Lepreau Harbor, where these rocks are well exposed, they apparently rest directly and conformably upon the Devonian shales and sandstones of the Mispec and Little River groups of 

the St. John Devonian basin. As they elsewhere underlie the basal beds of the lower Carboniferous, including the marine limestones of that series, it would now appear that the rocks of 

the Perry River group, as a whole, represent the upper portion of the Devonian system of 

southern New Brunswick, as was early suggested by Sir William Dawson and others from the 

evidence of the contained plants. 

The above statement by Ells that the rocks of the so-called "Perry" of Lepreau 

Harbor rest conformably upon Devonian rocks of the Mispec group raises a question 

as to the relation of the" Perry" at Lepreau with the true Perry formation of Maine. 

If the Mispec rocks are meso-Carboniferous (seep. 331) strata which rest conformably 

upon them must be middle Carboniferous or later; whereas the true Perry is Devonian, probably Upper Devonian. Furthermore, plant remains which, like those of 

the Mispec, are now referred to the middle Carboniferous have been found near 

Lepreau Harbor. In view of the great thickness and highly disturbed condition of 

the strata it is probable that more than one terrane is represented in that vicinity. 

The Devonian age of the Perry formation in the type locality in Maine has 

recently been placed beyond question by the investigation made by Smith and 

White/59 who have assembled in the field and from the literature the essential facts 

of stratigraphy and paleontology. They thus describe the Perry formation: 

The Perry formation as exposed in the towns of Robbinston and Perry is divisible into four 

members. Two of these members consist of sed-imentary strata, while the other two are inter·· 

bedded lavas and associated volcanic breccia. The section may be described thus: 

Upper lava: Green lava with columnar parting and amygdaloidal texture. Includes one bed of conglomerate 

and sandstone. 

Upper sandstone: Coarse red and brown sandstone and conglomerate, with small amounts of shale. Includes 

one flow of lava near base. 

Lower lava: Basaltic lava and breccia. Includes one thin bed of conglomerate near top. 

Lower conglomerate: Coarse conglomerate and red sandstone, with thin beds of sandy shale. 

The thickness of these members can not be definitely given. The lowest member is evidently the thickest, but probably its thickness varies considerably in different parts of the area. 

As will be noted later, the Perry sediments were largely shore deposits, so that the distance 

from the source of the material would control largely the thickness of the beds. In case of the 

volcanic members the different lava flows give the impression of being rather more persistent 

in thickness than might be expected. 

White made a thorough study of the plant remains originally described by Sir 

William Dawson, and of others including new collections from the Perry. He 

describes the species, discusses their distribution, and concludes: 759a 

Of the entire flora described a from Perry, Sphenopteris filicula and Bepidocystis siliqua 

are types which appear to belong to groups more or less distinctly characteristic of the lower 

portion of the lower Carboniferous. The fragment described as Palceostachya? sp., and the 

forms earlier published as Lycopodites comosus and Oarpolithes lunatus are too little known or 

a Lepidodendron gaspianum, a characteristic Devonian plant, unknown in the Carboniferous, and reported from 

Perry by Dawson, is omitted from the list as insufficiently represented for identification in the Perry material which 

I have seen. 
328 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

too ambiguous to be at present of stratigraphic value. The correlative significance of Sporangites jaclcsoni, which has not been found elsewhere, is also as yet undetermined. The remaining 

species which comprise the main body of the Perry flora are Devonian. 

As will have been seen in the foregoing review, the evidence of the geologic distribution, so 

far as known, of the identical species, of the genera themselves, and of the most nearly related 

plant forms indicates distinctly and overwhelmingly a Devonian age for the Perry formation. 

The stratigraphic range of most of the species and their allies strongly points to a place in the 

upper Devonian, the preponderance of the evidence being in favor of the Catskill-Chemung 

stage. Allowing for the full weight of the two or three species of close lower Carboniferous 

affinities, the flora can not at latest be assigned to a stage above the upper Catskill as developed 

in northeastern Pennsylvania and southeastern New York. Compared with the flora of other 

continents the closest paleontologic affinities of the Perry flora are found in the plant associations 

of the Donetz and of the Arctic Devonian. 

The occurrence of closely related species of Barinophyton and Leptophlreum together with 

Archasopteris in the Devonian of Australia affords an interesting example of the remarkable 

intercontinental distribution of the later Devonian plant types. 

The conclusions as to the age of the Perry beds recorded long ago by Sir William Dawson 

are fully corroborated by the study of more extensive material and the discovery of additional 

plants. 

The Devonian of Aroostook County, Maine, is discussed by. Williams and 

Gregory. 937a Williams gives the following classification of the local subdivisions: 

Recent investigation of the rocks of the northern part of Aroostook County has brought 

to light a few facts regarding the stratigraphic terranes, which may be stated with some degree 

of precision. • 

There are a few well-marked groups of rocks which are distinguishable by their lithologic 

characters, and the relative age of which is determined by their contained fossils. The order 

which the present knowledge of the faunas seems to indicate is as follows: 

Devonian: 

9. Mapleton sandstone. 

8. Moose River sandstone. 

Silurian: 

7. Chapman sandstone. [a] 

6. Square Lake limestone. [a] 

5. Ashland limestone. 

4. Ashland shales. 

3. Sheridan sandstone. 

2. Graptolite shales. 

1. Aroostook limestone. 

Below the Aroostook limestones are slates, which it is believed are of Cambrian age, but 

positive evidence of the age is wanting. 

The lower seven belong to the Silurian; the upper two to the Devonian. The paleontologic evidence is clear in placing 1 to 5 below the Lower Helderberg horizon of the New York 

series. 

The Aroostook limestone, on both stratigraphic and paleontologic grounds, is believed to 

be older than any other of the terranes mentioned in this list. 

The Ashland limes.tone, Ashland shales, and Sheridan sandstone are faunally closely associated and belong together as the representatives of the Clinton-Niagara of the New York 

standard. 

The Graptolite shales the writer believes to be of Clinton age, but their stratigraphic position in the Maine series is not satisfactorily established. They may belong in the midst of the 

a Now known to be of Devonian age.-B. \V. 
DEVONIAN. 329 

series 3, 4, 5, or even above them; more evidence will be needed to determine their position 

with certainty. 

The Chapman sandstone fauna is younger than the Square Lake fauna; the present opinion 

is that it corresponds closely with the Lower Oriskany of the New York and interior series. 

The identification of the fauna with Honeyman's zone D Arisaig and with the "Tilestone" 

fauna of Wales establishes its place at the top of the Silurian. (See Am. Jour. Sci., 4th ser., 

vol. 9, p. 203.) 

The Moose River fauna is a facies of the Eodevonian and represents the Oriskany. 

The Mapleton sandstone is the representative of the higher parts of the Gaspe sandstone, 

and is the Old Red sandstone facies not expressed in New York until a point higher up, in the 

Catskill sandstone, is reached. 

Besides these terranes, determinable by their fossils, there are slates and crystalline rocks, 

the precise age of which is undetermined. The slates are presumably Cambrian or pre-Cambrian. 

L 20. NOV A SCOTIA. 

The supposed Devonian rocks of Nova Scotia were described in 1886 and 1890-

91 by Fletcher/34b• 335c who distinguished a "lower conglomerate group," a "middle 

gray sandstone and slate group," and an "upper red slate and sandstone group." 

In his second report Fletcher gave the following general account: 

Most of the metamorphic areas of the hills of Antigonish, Pictou, and Colchester counties 

consist of rocks whose geological position is between the group containing marine fossils of Lower 

Helderberg age, and the Carboniferous or Mountain limestone, also characterized by the occurrence of marine types, whereas all the fossils found in the intervening Devonian consist of shells 

indicative of shallow-water origin, and of plants both drifted and erect, indicating land conditions. Between this series and those underlying and overlying, there is everywhere the clearest 

evidence of enormous unconformity, and although from the abundance of their plant remains 

they have sometimes been confounded with Millstone grit and even higher strata, their relations to the Carboniferous limestone at the East Mountain of Onslow and Penny's Mountain, at 

Shubenacadie, Stewiacke, Walton, Cheverie, Parrsboro, and wherever the two series are in 

contact, and the ease with which they can be traced from point to point, show that they are to 

be compared rather with the Mispeck and Little River groups of New Brunswick, and that the 

Carboniferous limestone rests unconformably on the slates. 

In spite of their disturbed and partly altered condition, these rocks have yielded 

fossils, which show that a considerable part of the supposed Devonian contains a 

middle Carboniferous fauna and flora. The stratigraphic evidence of Devonian 

age has been controverted by the paleontologic evidence of Carboniferous age. 

Ami 22 has recently summed up the results of investigations covering both lines of 

evidence as follows: 

For many years it was taken for granted that the highly fossiliferous beds of carbonaceous 

shales, etc., known as "the fern ledges" of New Brunswick, were of Devonian age, although the 

character of the flora, even at first sight, is one of decidedly Carboniferous facies. The 80 or 

more species representing the flora of that period are preeminently Carboniferous, and recently 

Mr. David White has recorded no less than 17 species of Pottsville forms, which came originally 

from the "fern ledges." The Lancas~,;er formation of the author was defined as that series 

of strata which held this very charactarie 1.ic flora, and it is capped by another Carboniferous 

formation consisting of red shales and conglomerates, with but few species occurring therein; 

to which formation the designation Mispeck formation of New Brunswick was applied. These 

two formations, the Lancaster and the Mispeck, find their equivalents in the Union and Riversdale of Nova Scotia, which Sir William Dawson always held to be of Middle Carboniferous age 

(Middlestone grit). 
330 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The main argument advanced by those that held that these four Middle Carboniferous 

formations were "Devonian" was based on the supposition that the Lower Carboniferous 

limestones rested unconformably on these same or equivalent formations. 

In two of the crucial localities in Nova Scotia visited by the writer some time ago, where 

Carboniferous shale rested unconformably on shales, etc., it has been ascertained beyond a 

doubt that in one instance (at West Bay, near Partridge Island and Parrsboro, in Cumberland 

County, Nova Scotia) the Carboniferous limestones proved, on examination of the organic 

remains entombed in them, to be of true and undoubted Upper Carboniferous age and not Lower 

Carboniferous, while in the other instance (in the MacArras Brook region of Nova Scotia, where 

the "Lower Carboniferous" strata rested unconformably on the so-called "rocks of Union," 

or Union formation) the writer finds that the subjacent strata are in no sense equivalent to the 

rocks of the Union formation at all (as they are developed at the type locality near Union station, on the Intercolonial Railway, just below Riversdale). The Lower Carboniferous strata 

at MacArras Brook rest unconformably on the upturned edges of the lowest Devonian of that 

region, as the fossil evidence obtained very clearly showed. The Knoydart formation, of EoDevonian age, as seen and developed at MacArras Brook, contains a fauna, which is so nearly 

allied and identical with that of the lower "Old Red sandstone" strata of Scotland and Great 

Britain generally that the two can very well be classed as homotaxial and belonging to the same 

period in the history of the earth's crust-a horizon or formation which had not been previously 

recorded in America and which, nevertheless, occupies a definite position, not at the summit of 

the Devonian, as some geologists would have us believe, but indeed at the ver~ bottom of the 

system or division of the time scale. 

The error of correlating the rocks of MacArras Brook with those of the Union has led to 

confusion, and the paleontological evidence, which has been obtained by the writer in both 

series of strata has conclusively shown that the one (Knoydart formation) indicates a typical 

"Old Red sandstone" fauna that is lowermost Devonian in age, while the other formation is 

distinctly referable to the Middle Carboniferous, being associated with and intimately related 

to the "rocks of Riversdale," containing a typical Meso-Carboniferous flora and fauna, which 

opinion Messrs. R. Kidston, Prof. David White, Dr. Wheelton Hind, Prof. Charles Brongniart, 

and Dr. Henry Woodward and others have shared with the writer. The fact that these "rocks 

of Union" and the "rocks of Riversdale" had for so many years been referred to the Devonian 

by Canadian geologists led the writer to seek diligently for Devonian types and forms in those 

strata, and it must be distinctly stated here that I utterly failed to obtain any horizon markers 

of Devonian aspect in the true rocks of Union and Riversdale. All types found were of decidedly 

Carboniferous facies and well up in that system. The fossil plants, the fossil fishes, the Crustacea, 

the insects, etc., all pointed to a horizor of Meso-Carboniferous age, and there we are constrained to place them. 

I desire here to correct an error made by myself in following an·d accepting without verification the statement made by stratigraphical geologists that the "rocks of Union" and the 

"rocks of Riversdale" were always found overlain by the marine limestones of the "Lower Carboniferous" and were therefore older. On the contrary, I find that the so-called "rocks of 

Union" as they are developed at MacArras Brook, are the only strata that can in any sense be 

referred to the Devonian; in which instance it so happens that these so-called "rocks of Union" 

are not at all the same as those of the Union formation proper. This error on my part in taking 

for granted that all the strata were one and the same formation, and which had been referred 

to the "rocks of the Union" and the "rocks of the Riversdale" as unconformably below the 

limestones of the Lower Carboniferous, as the stratigraphical geologists had said, led me to 

make the further statement that the "rocks of Union" and the "rocks of Riversdale" were 

Eo-Carboniferous in age. In referring these strata to the Carboniferous, I was guided by the 

fossil remains entombed in them, whereas I was misled by the succession as given by the stratigraphical geologists without any qualifications. It was only when the faunas of the Knoydart 

formation, from the so-called "rocks of Union" in the MacArras Brook region, were obtained 
DEVONIAN. 331 

and determined by Dr. A. Smith Woodward and Dr. Henry Woodward and others, that the 

confusion that existed was evident to me, and the necessity of separating these two sets of strata 

became apparent. This led to the separation of the Knoydart formations from their supposed 

equivalents "the red rocks of Union." I have no hesitation in saying now that the Union and 

Riversdale formations, as they are developed at the type localities at the Union and Riversdale 

in Colchester county in Nova Scotia, are Carboniferous in age, and are Meso-Carboniferous at 

that. Further, it is also evident that the New Brunswick equivalents of these two formations, 

namely, the Mispeck and the Lancaster formations (the latter sometimes designated as the 

Little River group), can not any longer be classified as Devonian, but as truly Meso-Carboniferous 

formations, with an abundant flora found the world over, and in all countries other than Canada 

referred to as the Middle Carboniferous. 

In view of the conclusion that the supposed Devonian of the original descriptions is in part Carboniferous, it is difficult to determine what the Devonian rocks 

of Pictou, Antigonish, and Colchester really are. A basal Devonian formation 

is, however, distinguished by Ami 18 as the Knoydart formation of Antigonish 

County. A detailed section of the rocks by Fletcher 180 shows 684 feet of red sandstone and shale with greenish layers and thin flinty or calcareous or carbonaceous 

layers, some of which consist of volcanic ash. The included fossils are ostracoderms, constituting a very primitive and early type of fishes and establishing a close 

correlation with the lower Old Red sandstone qf Great Britain. 

The Silurian and Devonian iron-bearing formations of Digby and Annapolis 

counties, southwestern Nova Scotia, are thus described by J. W. Dawson: 266 

In Nova Scotia the rocks older than the Carboniferous system have all undergone more or 

less alteration and disturbance. This, with the imperfect preservation of their fossils and their 

inland position, renders the working up of their details of structure very difficult. Large 

tracts of country thus remain in a state of uncertainty, their rocks being manifestly older than 

the Carboniferous, but yet otherwise of uncertain age. In the case of the Devonian, the only 

place in which it has been clearly made out as distinct from the Silurian is the belt of hilly country extending along the south side of the Annapolis Valley. Here, in the section of the Nictaux 

River, the first old rocks that are seen to emerge from beneath the New Red sandstone of the 

low country are fine-grained slates, which I shall describe in the sequel as Upper Silurian. Their 

strike is N. 30° to 60° E., and their dip to the southeast at an angle of 72°. Interstratified with 

these are hard and coarse beds, some of them having a trappean aspect. In following these rocks 

to the southeast, or in ascending order, they assume the aspect of the New Canaan beds; but I 

could find no fossils except in loose pieces of coarse limestone, and these have the aspect of the 

Upper Arisaig series, or newest Silurian of the eastern part of Nova Scotia. In these and in some 

specimens recently obtained by Mr. Hartt I observe Orthoceras elegantulum, Bucania trilobita, 

Oornulites flexuosus, Spirifer rug::ecosta ?, and apparently Chonetes novascotica, with a large 

Orthoceras, and several other shells not as yet seen elsewhere-all Upper Silurian. These 

fossils appear to indicate that there is in this region a continuance of the upper Arisaig series 

nearly to the base of the Devonian rocks next to be noticed. 

After a space of nearly a mile, which may represent a great thickness of unseen beds, we 

reach a band of highly fossiliferous peroxide of iron, with dark-colored coarse slates, dipping 

S. 30° E. at a very high angle. The iron ore is from 3 to 4! feet in thickness. The fossils of 

the ironstone and the accompanying beds, as far as they can be identified, are Spirifer arenosus, 

Strophodonta magnifica, Atrypa unguiformis, Strophomena depressa, and species of Avicula, 

Bellerophon, Favosites, and Zaphrentis, etc. These, Professor Hall compares with the fauna 

of the Oriskany sandstone; and they seem to give indubitable testimony that the- Nictaux iron 

ore is of Lower Devonian age. * * * 
332 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

To the southward of the ore the country exhibits a succession of ridges of slate holding 

similar fossils and probably representing a thick series of Devonian beds, though it is quite possible that some of them may be repeated by faults or folds. Farther to the south these slates 

are associated with bands of crystalline greenstone and quartz rock and are then interrupted by 

a great mass of white granite, which extends far into the interior and separates these beds from 

the similar nonfossiliferous rocks on the inner side of the metamorphic band of the Atlantic 

coast. The Devonian beds appear to dip into the granite, which is intrusive and alters the slates 

near the junction into gneissoid rock holding garnets. The granite sends veins into the slates 

and near the junction contains numerous angular fragments of altered slate. 

* * * * * * * * * 

At Moose River the iron ore and its associated beds recur on the western side of the granite 

before mentioned but in a state of greater metamorphism than at Nictaux. The iron is here 

in the state of magnetic ore but still holds fossil shells of the same species with those of Nictaux. 

Still farther westward, at Bear River, near the bridge by which the main road crosses this 

stream, beds equivalent to those of Nictaux occur with a profusion of fossils. The iron ore is 

not seen, but there are highly fossiliferous slates and coarse arenaceous limestone and a bed of 

gray sandstone with numerous indistinct impressions apparently of plants. In addition to 

several of the fossils found at Nictaux, these beds afford Tentaculites, an Atrypa, apparently 

identical with an undescribed species very characteristic of the Devonian sandstones of Gaspe, 

and a coral which Mr. Billings identifies with the Pleurodictyum problematicum Goldfuss, a form 

which occurs in the lower Devonian in England and on the continent of Europe. 

West ward of Bear River rocks resembling in mineral character those previously described, 

and probably of Devonian and Upper Silurian age, extend with similar strike but in an altered 

condition and in so far as I have been able to ascertain destitute of fossils quite to the western 

extremity of the peninsula, where they turn more to the southward and are, as I suppose, 

repeated by a sharp synclinal fold, after which they are succeeded by the Atlantic coast series, 

of lower Silurian date and consisting of quartzite and clay slate, with chlorite and hornblende 

slates at Yarmouth and its vicinity, and farther to the southeast of mica slate and gneiss. 

I can not certainly indicate the Devonian system in other parts of Nova Scotia. There are, 

however, in various places, at the margin of the Carboniferous areas, or projecting through these 

beds, rocks which may be Devonian, though, not having afforded characteristic fossils, their 

age must remain doubtful, as they might possibly prove to be altered members of the Lower 

Carboniferous or rocks of Silurian date. They are usually hard gray or purplish sandstones or 

quartzites, associated with gray or purplish slates or shales. 

The above description is quoted by Bailey,.43a who adds: 

In 1892 a collection of fossils from Nictaux, Bear River, and Mistake settlement was made 

by the writer and Mr. V•l. H. Prest and tended to confirm the conclusions of Sir William Dawson, 

so far at least as regards the beds of Nictaux and Bear River. They were examined by Dr. 

H. M. Ami, who states,a as to the two former points at least, that the beds are transitional, 

being either at the summit of the Silurian or at the base of the Devonian epoch, the weight of 

evidence being perhaps in favor ofthe Eo-Devonian. The fossils from Mistake settlement indicate a Silurian tract. 

Bailey then gives detailed descriptions of localities with lists of fossils collected 

at definite localities in the Nictaux-Torbrook, Clementsport, Bear River, and 

Mistake settlement districts. 

a In Report (by L. W. Bailey) on southwestern Nova Scotia, vol. (), pt. Q, 1892-93, p. 14. 
DEVONIAN. 333 

M 11. ROCKY MOUNTAINS OF BRITISH COLUMBIA. 

In the eastern range of the Rocky Mountains, at the gap of Bow River, Alberta, 

Ordovician strata are followed with apparent conformity by a quartzite succeeded 

by dolomites of Devonian age. These strata do not occur in the western range, 

where the "Halysites beds" (Silurian) are present. McConnell 559c describes the 

Devonian ("Intermediate limestone") as follows: 

The Intermediate limestone underlies the Banff limestone conformably, and passage beds 

partaking of the lithological character of both groups occur at the junction of the formations. 

It is mainly composed of a great series of brownish dolomitic limestones and has a thickness of 

about 1,500 feet. The typical dolomites of this formation are dark brownish in color, are finely 

crystalline, and are often irregularly hardened by concretionary action. They have, in many 

places, a blotched appearance, due to small cavities becoming filled with calc spar, are cherty, 

and are characterized throughout by an abundance of corals. In some sections a light-grayish 

variety is not infrequent. It is more coarsely crystalline than the dark variety and is unfossiliferous. In addition to the dolomites, beds and bands of sandstone, quartzite, and calcareous 

limestone are found all through the series. A light-yellowish siliceous band, varying in thickness from 100 to 400 feet, occurs near its base, on the south fork of Ghost River and along the 

eastern part of Devil's Lake valley, and is also found at the entrance to the White Man's Pass. 

A good section across this series was obtained in the first range, near the Gap of the Bow. 

Here it dips to the west, at an angle of 40°, and is inclosed between the Castle Mountain and 

Banff limestones. The former, at this point, is terminated above by some shaly nondolomitic 

limestone, overlying which is about 40 feet of reddish and bright-yellowish weathering sandstones and quartzites, forming the base of the intermediate formation. Above these come 

several hundred feet of brownish-weathering, irregularly hardened magnesian limestone, holding 

cherts and corals, succeeded by light-colored, regularly bedded crystalline dolomites. The 

latter grade upward into a series of alternating beds of the two last varieties, associated with 

some beds of quartzite. Then comes a small band, consisting of soft greenish crumbling argillaceous sandstone, and hard yellowish-weathering quartzites, overlying which are 20 feet of 

grayish limestone. This limestone is succeeded by magnesian limestones and quartzites, above 

which come 50 feet of heavily bedded brownish-weathering dolomites, forming the top of the 

series and underlying the bluish massive beds of the Banff limestone. This section affords a 

fair general illustration of the relative lithological importance of the different members of the 

series, but could not be even approximately duplicated half a mile away, owing to differences 

in local detail. 

* * * * * * * * * 

The fossils of the Intermediate limestone are usually badly preserved and consist mainly 

of almost structureless corals. 

M 19. NORTHERN NEW BRUNSWICK. 

A small area of Eo-Devonian is shown on the map at the west end of Chaleur Bay. 

The rocks are red sandstone and gray shale associated with intrusive traps and 

with gray and purple feldspathic ash rocks. Coarse sandstones and conglomerates 

occur and carry Devonian plant remains. 305 

On the Restigouche, at the western extremity of Chaleur Bay, occurs a small 

area of Devonian strata which have afforded an interesting fish fauna and some 

plant remains. Whiteaves 922 narrates the early discoveries and summarizes the 

facts as follows: 

The first of these discoveries led to further investigations by officers of the Canadian Survey in 1880, 1881, and 1882, which revealed the existence of a remarkable assemblage of fossil 
334 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

fishes and land plants of Upper Devonian age at Scaumenac Bay, and of an entirely different 

series of fishes and plants, of Lower Devonian age, on the opposite or New Brunswick side of 

the river, near Campbellton. Large collections were made at each of these localities, especially 

of the fossil fishes, which were described by the writer in 1880,a 1881,b and 1883,0 and described 

and illustrated in 1887d and 1889.e Many of these specimens were exhibited and described at 

the meeting of this association at Montreal in 1882. 

Comments on the species and references to the literature follow in vVhiteaves's 

account. 

M 20. GASPE PENINSULA. 

Logan 544r described from this region the Gaspe limestones and Gaspe sandstones 

and assigned them respectively to the Silurian and Devonian. Ells 306 reviewed 

their distribution and stratigraphy in the field and concluded thatOf these Gaspe limestones it is now considered that only the two lower memb•ws, representing 

a thickness of 160 feet, can with propriety be assigned to this system [Silurian] while the preponderance of fossils of Devonian aspect, even in the basal bed, renders it probable that the whole 

may ultimately be transferred to the Devonian system. 

This statement by Ells is quoted with agreement by Clarke 157b in a monographic 

work on the Gaspe section. Clarke, however, goes further and places all of the 

Gaspe limestones, including Logan's divisions 1 and 2 (St. Alban), in the Devonian 

as equivalents of the Helderbergian of New Y ork. 1570 The Canadian Survey has not 

accepted this correlation and the map of North America expresses the classification 

and distribution determined by Ells. 

According to Logan the Gaspe limestones "comprise about 2,000 feet. They 

are intimately interbedded with calcareous argillaceous shales and exhibit intraformational contortions and conglomerates." The Gaspe sandstones, which aggregate approximately 7,000 feet, are partly conglomeratic and vary in color from drab 

to red. They contain plant as well as marine animal remains and are interpreted 

by Clarke as the deposit from a land of strong relief in a lagoon communicating from 

time to time with the sea. 

The fossils from the Gaspe sandstones are described by Billings, 83 who gives 

a condensed statement of Logan's section. 

The age of the Gaspe sandstones has been discussed by "\Villiams, Schuchert, and 

Clarke. "\Villiams 936 briefly states the problem: 

In the York River beds at the base of the Gaspe sandstones there is found a number (at 

least a dozen) of fossils which if found alone would be intrepreted as positive evidence of an 

Ori.skanian fauna; associated with these is another lot of fossils, at least as many, which if found 

alone would be as positive evidence of a Hamiltonian fauna. The sediments were deposited at 

some particular epoch of the geological time scale. What does this composite fauna signify as 

to the epoch to which the York River beds belong? 

Dr. Clarke in the volume referred to gives the decision in favor of the Hamiltonian epoch, 

apparently on the ground of the greater number of species identical or closely related to Hamila Am. Jour. Sci., 3d ser., vol. 20, p. 132; reprinted in Canadian Naturalist and Geologist, vol. 10, p. 23. 

bAm. Jour. Sci., 3d ser., vol. 21, p. 94; reprinted in Ann. and Mag. Nat. Hist., 5th ser., vol. 8, p. 159; and Canadian Naturalist and Geologist, new ser., vol. 10, pp. 27, 93. 

cAm. Naturalist, vol. 17, p. 158. 

d Trans. Royal Soc. Canada, vol. 4, sec. 4, p. 101. 

e Idem, vol. 6, sec. 4, p. 77. 
DEVONIAN. 335 

tonian forms. If we accept his view it follows that the associated Oriskanian forms continued 

to live on after the epoch of the Oriskanian fauna into Hamiltonian time. 

By the interpretation here offere@ it is assumed that the Hamiltonian types of the fauna. 

are possible ancestors of Hamiltonian species living in the Oriskanian epoch, which by some 

movements of the currents of the ocean were brought together in the Acadian province before 

the revolution which upset the biologic equilibrium of the Oriskanian fauna had completed its 

work. 

The further conclusion is that it was the same events which caused the cessation of the 

distinctive Oriskanian fauna, which brought into this area the ancestors of the Hamilton 

species, and that the geologic time of the events was approximately equivalent to the Schoharie' 

epoch of New York State. 

M-N 14. MANITOBA. 

The Devonian of Manitoba consists of about 500 feet of strata, chiefly dolomite 

which represent Lower, Middle, and Upper Devonian terranes. They are described 

by Tyrrell 817 as follows: 

Upper Devonian or Manitoban: Feet. 

Light-gray hard, brittle limestone cont,aining Athyris vittata, etc., underlain by red argillites, 

outcropping at Rose Island and in the vicinity in Swan Lake, and at Point Wilkins ..... 100 

Light-gray hard limestone, seen at Onion Point, Snake Island, Beardy Island, etc .. _______ 40 

Red and gray shale, seen near the mouth of Bell River, south of Weston Point, etc._______ 70 

Middle Devonian or \Vinnipegosan: 

Whitish or light-yellow hard, tough, generally compact dolomite containing Stringocephalus 

b1<rtini and numerous other fossils. It outcrops chiefly on the island and shores of Dawson Bay, and southward to Point Richard on Lake Manitoba ..... _____ ._ .. _ .. __ . ___ .. ____ 100 

Porous spongy yellow dolomites of Pemmican Island, Devil's Point, Macoun Point, etc .. __ 100 

Lower Devonian: 

These beds have not been clearly defined, but they appear to be composed of red and other 

shales. ____ . __ . ______ . __ ._ ...... ____ . ______ .. __ ................ _ ...................... 100 

\Vhiteaves 917 has described the fossils from these Devonian rocks and says: 

It has already been stated that all the fossils that are e~mmerated or described in the present 

paper are probably from the Middle and Upper Devonian. The Middle Devonian appears to 

be represented in this region by the Stringocephalus zone and the 100 feet or more of fossiliferous dolomite immediately beneath it, and the Upper Devonian by all the beds above the 

Striugocephalus zone and beneath the Cretaceous. 

The discovery of dolomites in which Stringocephalus burtini is one of the most characteristic fossils, at many localities on the shores or islands of Lakes Manitoba and Winnipegosis, 

is of considerable interest to the geologist. In Manitoba the Stringocephalus zone appears to 

occupy much the same stratigraphical position as the Stringocephalus limestone of Germany and 

England, and it is noticeable that among the fossils of the Stringocephalus zone of Manitoba 

there are several which can be identified with well-known European species.a 

The "Cuboides zone" appears to be represented in this region by those beds on the Red 

Deer River and elsewhere. 

M-N 16-17. JAMES BAY, ONTARIO. 

In 1875 Bell 65 reported the occurrence of dark-gray bituminous limestone at the 

Grand Rapids of the Mattagami (latitude 50°, longitude 82°) and collected fossils, 

which Whiteaves reported as being of Devonian age, of the horizon of the "Corniferous" limestone. The strata are exposed in a cliff 40 feet high. They are flat 

lying and rarely outcrop in the district, but extend north beneath James Bay and 

beyond Albany River. Dowling 291 b states that the Devonian rocks do not reach 

a For list of fossils see the work cited.-B. W. 
336 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

the Attawapiskat on the north but are confined to the southern part of James Bay 

and the adjacent country extending a short distance north of the Albany. 

Parks 629 describes the strata exposed on Kwataboahegan River as limestones 

of a yellowish-brown color, literally filled with organic remains. A grayish limestone, poorer in mollusks but richer in corals and brachiopods, also occurs, but the 

relations of the two were not determined. Many species are described and figured. 

N 9, 0 8. SOUTHEASTERN ALASKA. 

Devonian limestones occur intercalated with igneous rocks in the islands of 

southeastern Alaska. The recent work of Wright and Kindle has resulted in collections of fossils which have marked European affinities and represent Lower, 

Middle, and Upper Devonian but which are not related to the American contemporaneous faunas. No complete section of the series is known. Exposures on 

Long Island, Kasaan Bay (latitude 55°, longitude 133°), show 470 feet of Middle 

Devonian limestone, conformably overlying bedded igneous rocks. Lower Devonian 

limestone occurs at Freshwater Bay, Chichagof Island (latitude 58°, longitude 135°). 

On the west coast of Prince of Wales Island fossils of the Upper Devonian have been 

collected. 496a 

N-0 12-13. ALBERTA AND SASKATCHEWAN. 

Devonian limestone extends horizontally beneath the superficial deposits of 

parts of Saskatchewan and Alberta, outcropping here and there in river gorges and 

occasioning rapids in the streams. On the east it rests upon "Laurentian" and on 

the west it is overlain by horizontal Cretaceous beds ("Tar sands," referred to 

the Dakota by McConnell). 5

61b The section on lower Peace River, according to 

Macoun, 568 exhibits thin-bedded limestone strata made up almost whollyof branching 

corals and carrying beds of white gypsum. Higher up the stream the limestone is 

evenly stratified, is light grayish or cream-colored, and alternates with softer, more 

argillaceous bands. 561 

0-Q 9-12. MACKENZIE BASIN. 

East of the Rocky Mountains in the Mackenzie basin Devonian rocks have a 

wide distribution. The strata classed as Devonian may include Silurian below and 

exhibit a transition phase toward the Carboniferous above. McConnell 560 states: 

Devonian rocks * * * underlie the greater part of the country bordering the Mackenzie, all the way from Great Slave Lake to below old Fort Good Hope, a distance measured 

in a straight line over 700 miles. They were found all around the western arm of Great Slave 

Lake and were traced up Hay River to the falls and up the Liard to the "Long Reach." South 

of the Liard and extending as far south as the Peace River, the Devonian outcrops at the surface 

in a broad band, averaging fully 150 miles in width, striking in a northwesterly and southeasterly direction, parallel to the western margin of the Archean axis. On the southwest it is 

generally overlain by the Cretaceous and on the northeast overlaps all the older Paleozoic 

formations and comes directly in contact with the Archean. In all this region the beds are 

practically undisturbed and are seldom affected by dips exceeding a few feet to the mile. 

* * * * * * * * * Throughout the Mackenzie district the Devonian is generally divisible lithologically into 

an upper and lower limestone, separated by a varying thickness of shales and shaly limestones, 

but in some cases limestones occur throughout. The upper division has an approximate thi~kness of 300 feet and consists of a compact yellowish-weathering limestone, occasionally almost 
DEVONIAK. 337 

wholly composed of corals, interstrati:fied with some dolomitic beds. This limestone is well 

exposed at the falls on Hay River and also at the Ramparts, on the Mackenzie. In both these 

places it is underlain by several hundred feet of greenish and bluish shales, alternating with thin 

limestone beds. At the "Grand View,'' on the Mackenzie, the shales are hard and fissile and 

are blackened a~d in places saturated with petroleum. At the Rock by the River Side and at 

other places where the beds are tilted and older rocks exposed the middle division is underlain 

by 2,000 feet or more of grayish limestones and dolomites interbedded occasionally with some 

quartzites. No fossils were collected from the lower part of this series, and rocks older than the 

Devonian may possibly be represented in it. 

Representative collections of fossils, showing a mixture of Hamilton and Chemung forms, 

were obtained from the upper part of the shales on Hay River, at a point about 40 miles above 

its mouth, and from the same horizon at the Ramparts, on the Mackenzie. The lithological 

characters and the stratigraphical relations of the limestones at these two points, notwithstanding the fact that they are separated by a distance of over 570 miles, are almost identical. The 

fossil faunas also at the two points show similar close relations, the principal differences being 

the presence of Rhynchonella cuboides and Spirifera disjuncta at Hay River and of Stringocephalus 

burtini at the Ramparts. This might seem to indicate that the beds at the Ramparts are slightly 

older than those at Hay River, but Mr. Whiteaves thinks that both are referable to the Cuboides 

zone. 

Fossils collected from the Devonian of the Mackenzie basin by early expeditions were described by Meek, 585a who gives an account of the history of exploration 

and of the fossiliferous localities. Whiteaves 916 has discussed the collections subsequently made by the Canadian Survey parties. He describes the Devonian 

species from the Mackenzie represented in the museum of the Canadian Survey and 

lists them according to localities from southeast to northwest. He then comments: 

An analysis of t.hese lists shows that 22 of the species are found also in the Hamilton formation of Ontario or the State of New York. [List follows.] 

In the Mackenzie River district, however, the subdivisions of the Devonian system that 

exist in the State of New Y <M"k and Ontario are probably not recognizable, and there are strong 

reasons for supposing that the whole of the fossils reported upon in these pages belong to the 

"Cuboides zone." 

It is true that Rhynchonella cuboides itself has so far been found only on the Peace and 

Hay rivers, where it is invariably associated with Spirifera disjuncta (or verneuili), but other 

fossils eminently characteristic of the Cuboides zone will be noticed in nearly all the foregoing 

lists of species from the Athabasca and its tributaries or from the Mackenzie. 

The paper concludes with a discussion of the Cuboides fauna and a comparative 

list of 29 identical species from the Mackenzie basin and the European side of the 

Atlantic. 

P 4-5. ALASKA RANGE AND SOUTHERN ALASKA. 

Devonian rocks are included in the Paleozoic complex that forms the western 

slope of the Alaska Range, in the strike of the formations which occur throughout the 

Yukon-Tanana region, but they have not been differentiated. 101d Middle Devonian 

fossils have been found in a blue siliceous limestone at several localities. 

In the Copper River district the Nikolai greenstone, composed of volcanic flows, 

resembles the Rampart group (Devonian) of the Yukon and is shown by Brooks 101 

to occur stratigraphically at a similar horizon. Later studies, however, 599 have tended 

to prove a later age (late Carboniferous or Triassic) for the Nikolai greenstone. 

48011°--12----22 
338 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The Wellesley formation (conglomerate and slate) of upper Tanana and White 

rivers is either Carboniferous or Devonian. It is correlated with the Chisna formation of the Copper River district and possibly with the Cantwell formation of the 

Nenana River section and may represent the base of the Devonian, lying unconformably on older rocks. In a recent paper 104a Brooks places the Chi~ma, Wellesley, 

and Cantwell in the Carboniferous. 

P 8. YUKON TERRITORY. 

The Ogilvie Range, which forms the divide between Stewart and Peel rivers, 

is said by Keele 474 to consist largely of Devonian strata-limestones, ferruginous 

slates, and quartzites. These rocks are mapped as altered Paleozoics. Camsell 128d 

collected on Braine Creek, a tributary of Stewart River, and at Brainc Pass (latitude 

64° 30', longitude 135°), at its head, fossils which Whiteaves identified as Favosites, 

Productella, and Atrypa reticularis. 

The Braine Pass and section are described as follows :

128 

Topographically the country between Beaver River [a tributary of the Stewart] and Wind 

River [a tributary of the Peel] is one of rather rugged relief. This is the backbone of the great 

Rocky Mountain system, which here trends northwest and southeast, swinging slightly from 

its almost north and south trend farther south. This particular section is called the Ogilvie 

Range. Few prominent peaks occur, and from the tops of any of them a general accordance of 

level can be noticed. The summit of Braine Pass is estimated at about 3,400 feet, and the 

elevation of the highest peaks in the neighborhood at 6,800. * * * 

A section across the summit from the Beaver River to the Wind shows a series of closely 

folded and sometimes faulted limestones and slates with some quartzites and conglomerate. 

Cutting these are some diabase dikes and intrusive rocks. The succession in descending order 

is somewhat as follows: Massive dovecolored limestone becoming shaly at the base; bands of 

black slate; massive granular limestone containing fessils; ferruginous slates, weathering red; 

and black-weathering conglomerate at the base. * * * 

The great valley at the head of Braine Creek, which forms the pass across to the Wind 

River, is apparently a great line of weakness, which has resulted in [from] an overthrust fault, thus 

bringing up the underlying ferruginous slates to the surface. 

Some fossil corals and brachiopods collected from the limestone at the summit and lower 

down Braine Creek have been identified by Dr. Whiteaves as Devonian forms. 

Q 3. SEWARD PENINSULA. 

In the southeastern part of Seward Peninsula, north of Golofnin Bay, Devonian 

fossils have been found on Fish River. Somewhat farther northeast, on the Darby 

Range, fossils which are regarded as Devonian or possibly Carboniferous have been 

obtained. a 

Q 6-7. YUKON-TANANA REGION. 

The Rampart group, consisting of volcanic rocks with intercalated slates and 

limestones, was assigned by Brooks101e on fossil evidence to the Devonian, "probably 

to the Middle Devonian." In general terms the Devonian of the Yukon-Tanana 

region may be said to be made up of shales, slates, and cherts, with some limestones; 

locally ancient lava flows and tuffs predominate over the sediments. On the Yukon 

the igneous rocks are much more abundant than the sediments; on the Porcupine 

sediments are most abundant. The thickness of the group is much in doubt but 

a Smith, P. S., personal communication. 
DEVONIAN. 339 

can not be less than 3,000 feet and may be twice as great. The relation of the 

Devonian to the Silurian is unknown, but is probably one of unconformity. 102 

The following notes on the Porcupine Valley are taken from a paper by Kindle: 497 

The lowest division of the Devonian is a limestone formation about 325 feet in thickness. 

It is a massive light-gray to blue limestone weathering buff and considerably broken by joints. 

It rests apparently unconformably on the graptolite shales described above and is followed in 

the section by brown shale. The lower 5 feet of this shale may be seen resting directly on the 

limestone on the bank of the Salmontrout River just above its mouth. The total thickness of 

this shale is unknown, but, judging from the covered slope extending upward from the limestone 

along the Salmontrout River, it probably amounts to several hundred feet. Outcrops of the 

limestone described occur on both banks of the Porcupine immediately above the Salmontrout 

River, and it is proposed to call this formation the "Salmontrout limestone," from the Salmontrout River, which is the nearest geographic feature having a name available for a formation 

name. Fossils are abundant throughout this limestone. Its strike and dip are concordant 

with that of the subjacent Silurian shale and limestone and afford no evidence of deformation 

at the close of Silurian sedimentation. 

Although no angular unconformity is shown in the relations of the Silurian and Devonian 

series where observed, unconformable relations between the two are attested both by the lithology and the faunas. In passing from the Silurian to the Devonian the lithologic change is an 

abrupt transition from black shales to very pure limestones. The faunal change is from a Silurian graptolite fauna to a Middle Devonian fauna, the Lower Devonian fauna being absent. The 

Devonian limestone forms a continuous outcropping cliff 100 to 200 feet high for 1 mile above 

the Salmontrout River, along the east bank of the Porcupine. It also outcrops on the opposite 

side of the river in isolated exposures. 

Kindle gives a provisional list of 54 species preliminary to a full description of 

the fauna and concludes: 

There are present in it several species which are either closely allied to or identical with 

species which first appear in the better-known American sections at a Middle or Upper Devonian 

horizon. Since characteristic Lower Devonian species appear to be absent from the fauna, 

its age seems to be either Middle or Upper Devonian. The list contains some species not 

known below the Upper Devonian in the United States. One of the best known of these is 

a variety of Pugnax pugnus, a species which ranges from the Rocky Mountains to New York 

State and into the Mackenzie River district. Stropheodonta arcuata and S. calvini are also 

known to have a wide distribution in the Upper Devonian. P. pugnus and S. arcuata first 

appear in the New York section at the horizon of the Ithaca fauna. Associated with these 

Upper Devonian forms we find several species characteristic of Middle Devonian horizons. 

Among these are Pholidostrophia cf. iowensis, Oyrtina cf. hamiltonensis, Schuchertella chemungensis 

var. arctostriatus, Reticularia fimbriata, Nucleospira cf. concinna, and species resembling the 

European forms Gypidula cf. biplicatus and G. cf. galeatus. Two possible explanations of 

this association of Middle and Upper Devonian species in the same fauna present themselves. 

It has been shown by Williams and Kindle that Middle Devonian species sometimes persist 

till late Devonian time and appear in certain New York sections associated with Upper Devonian 

species.a It appears most probable, however, from what we know of the relations of Pugnax 

pugnus and its associated fauna to the Upper Devonian of New York, that the occurrence of 

Upper and Middle Devonian species in the same fauna at Old Rampart is not the result of late 

persistence of the earlier fauna. This species evidently migrated into the New York province 

from the northwest in Upper Devonian time. The two significant facts of its association 

with Middle Devonian fossils in an Alaskan fauna and its abrupt appearance in an Upper 

Devonian fauna in the United States, taken together, point very strongly to the probability 

that intercommunication between the eastern Alaska province and the interior American 

a Am. Jour. Sci., 4th ser., vol. 13, 1902, p. 429. 
340 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

province was cut off during :Middle Devonian, but became free about the beginning of Upper 

Devonian time, when conditions became favorable for the dispersal and migration of such 

forms as were adapted to it. Some of the species which had during Middle Devonian time 

been confined to this northern basin spread southward and helped to give a distinctive character to the Upper Devonian fauna as we know it in the United States. This appears to be 

the probable explanation of an association of species which upon casual examination seems 

to afford contradictory evidence as to the age of the fauna. If correct, the horizon represented 

is Middle Devonian. 

The Devonian limestone outcrops on both sides of the Salmontrout River near its mouth. 

Brownish-colored shales overlie the limestone here and extend apparently to the top of the high 

ridge lying to the south of the stream and represent a thickness of several hundred feet. No 

fossils were found in these shales, but they are supposed to represent the Upper Devonian, 

because their relation to the Devonian limestone is similar to that held by shales holding 

Devonian fossils along the Yukon River. Carboniferous beds replace the Devonian outcrops 

along the Porcupine about 1 mile below the Salmontrout River. These seem to be of Upper 

Carboniferous age. Evidence of faulting which appears on the north bank of the river here 

indicates that the Lower Carboniferous and perhaps a portion of the Upper Devonian may be 

concealed by a fault. The horizon of the brown shale appears locally to be largely occupied 

by beds of basalt representing old sea-bottom outflows during the Upper Devonian. 

The shale series which terminates the Devonian probably has a considerable thickness, 

though no estimate can be made from the exposures mentioned, because the thickness exposed 

to view is probably reduced by a fault lying to the southwest of the Salmontrout River. 

The shale horizon appears to be occupied locally by basalt flows of late Devonian age. 

A considerable thickness of such beds, which are believed to be of Devonian age, forms the 

lower end of the Upper Ramparts. This rock is a close-grained dark-greenish to black rock, 

showing bedding planes. These strike about north and south and dip east at about 40° for 

nearly half a mile above Redgate. Near the top of this igneous series a belt of sedimentary 

rocks is sandwiched into the basalts, showing the following beds: 

Section one-half mile above Redgate. 

Feet. 

Gray limestone.......................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 

Red and green shale ................................................. : . . . . . . . . . . . . . . . . . . . . 14 

Brecciated limestone with included masses of shale........... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

Light-gray limestone .................................. _ ............ _ ..... _ ... __ ._ .... __ ._._ 35 

Red shale ........................................ _ .. _ ............... __ . _ ...... _ ... _ ..... _ 30 

Two or three miles west of the Coleen River the basalts occur again. Here they overlie 

a considerable thickness of drab and pale-red shales. Black shales are interbedded with the 

upper belt of basalt at this point. 

Q 8. PEEL RIVER. 

Peel River, flowing north from the Rocky Mountains of Yukon Territory to 

the Mackenzie delta, traverses two canyons in folded black slates, which are alternately thick and thin bedded and in places bituminous, and crystalline limestone, 

which apparently underlies the slates. These strata are assigned by Camsell 128b 

to the Devonian on the ground of their lithologic resemblance to the Devonian of 

the Mackenzie Valley. 

Q-R 5. ENDICOTT RANGE. 

Nothing definite is known regarding the age of the pre-Carboniferous rocks of 

the Endicott Range, but the Fickett " series" and the Stuver "series" may include 

Devonian rocks, and the Bettles group is referred to the Devonian by Schrader, 

who found fossils of Devonian or Carboniferous age in gravels of Chandalar River. 

Brooks, 1010 however, regards the Bettles as possibly Silurian. 
DEVONIAN. 341 

R 3. CAPE LISBUR~. 

At Cape Lisburne Collier 164•

165a found 2,000 feet of sandstone and slate, conformably underlying Carboniferous (Mississippian) strata, and provisionally assigned 

them to the Devonian. 

S 27. EASTERN COAST OF GREENLAND. 

The Devonian of northeast Greenland is described by N athorst, 609d who says: 

The Silurian strata, as we have seen, are folded and compressed and partly metamorphosed. If this bears any relation to the formation of a mountain range, the folding took 

place before the deposition of the Devonian strata, for the latter show only a relatively slight 

amount of disturbance. Otherwise it must be surmised that the folding was the result of a 

depression of the Silurian strata along a fault at their eastern border, or perhaps between such 

a fault and another which can be imagined as passing west of the present boundary of the 

Archean. 

On the eastern side of Waltershausen Glacier, north of the mouth of the Myskox Fiord, 

the wall of the fiord is composed of a light-gray, nearly horizontal sandstone, upon which are 

situated two hills of red sandstone. At the place where North Fiord turns toward Josefs Fiord 

there is a slight syncline, the center of which is composed of red sandstone. As the height 

of the mountain here, according to Desen's calculation is 1,500 meters, the thickness of the 

formation in question ought to be still somewhat greater. On the south side of Franz Josefs 

Fiord the Silurian strata south of Cape Weber are overlain by gray sandstone, dipping eastward, 

and this is in turn followed by red sandstone. Tho dip then changes to west, so that the gray 

sandstone crops out again, then again dips east, and disappears. At Cape Graah (the point 

north of Duson's Fiord) the dip is again west and a gray-green sandstone is again visible. But 

I am not sure whether this belongs to the lower gray sandstone or is a member of the red; the 

latter view seems to me to be the most probable. In the gray-green sandstone, which is very 

micaceous, I collected at our place of anchorage, the 30th of August, some faint impressions 

of fossil plants, like those found in the Devonian strata of Spitzbergen, and a fish scale; and 

in the red sandstone, which overlies the green, I and Forester Nilson found many fine specimens 

which, according to A. Smith Woodward, belong to Holoptychius nobilissimus. Ag. Dusen, 

who botanized in the mountain to the south, said he found mollusks in the sandstone there. 

On a little outjutting point just east of here the rocks changed, being more brownish red and 

tough, with yellowish layers. * * * 

The Devonian strata on Elias Island are separated from the Silurian by a fault. This 

Devonian part possibly lies only in a local depression. But also north of Cape Weber there 

is a sharp fault between the two systems; the Devonian is lower in relation to the Silurian. 

On the south side of Franz Josefs Fiord the Devonian strata appeared to rest conformably 

upon the Silurian, although the Silurian strata appeared to have been deformed. Nearly 

everywhere this appeared to be the case near the contact between the two, and in my 

notebook I used a special term, "the irregular red," for this zone of deformation. 

S-U 15-20. ARCTIC ARCHIPELAGO AND NORTHWESTERN GREENLAND. 

The occurrence of Devonian strata on the eastern coast of Grinnell Land 

was mentioned by Dawson. 257g A full section is described by Schei from the 

southwestern shores of Ellesmere Land. (See pp. 266-268, Chapter V.) 
Color, light reddish purple. 

Symbol, 19. 

CHAPTER VII. 

PALEOZOIC UNDIVIDED. 

Distribution: Little-known regions of the northern Cordillera, Montana, and Canada. (See 

fig. 9.) 

Content: Paleozoic in general, where data do not suffice to map the divisions separately. 

Includes some known marine Triassic in the Canadian Rockies. 

METAMORPHIC PALEOZOIC UNDIVIDED. 

Color, light reddish purple with light dashes. 

Symbol, 20. 

Distribution: Venezuela, northeastern Appalachian region, northern Cordillera, California to 

Alaska. (See fig. 9.) 

Content: Metamorphic sedimentary rocks of known or supposed Paleozoic age, together with 

possibly pre-Paleozoic schists and some igneous intrusive rocks, which have not been 

separated. Includes some known marine Triassic in the Canadian Cordillera. 

Areas mapped as Paleozoic undivided. 

Page. 

B-C 18-19 ..................... Venezuela................................................................. 342 

C 20 ........................... Trinidad................................................................. 344 

D 16 .......................... Nicaragua and Honduras ....... :........................................... 345 

E 19 ........................... Santo Domingo and Porto Rko.................................... .... .. .. . 345 

F 17-18 ....................... Cuba and Isle of Pines..................................................... 348 

K 10 ........................... Klamath Mountains, Oregon............................................... 349 

K-L 11-12 ... _ ........... _ .... Idaho and southwestern Montana........................................... 350 

K-L 18-19 .................... New England ..................................................... :....... 350 

.M 9-10, N 8-9 .................. Vancouver Island and Queen Charlotte Islands.............................. 350 

M lD--11. ....................... Washington and British Col urn bia. . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . 352 

N 1D--11 to Q 7-9 .............. British Columbia and Yukon............................................... 353 

0-R 2-8 ...................... Alaska........................................................ . . . . . . . . . . 353 

B-C 18-19. VENEZUELA. 

For the geology of Venezuela, we refer to Sievers's work 741 on the Cordillera de 

Merida. Under the heading Archean, Sievers describes the granite, gneiss, mica 

schist and other crystalline schists, and clay slate. After describing the distribution 

of the granite, gneiss, and crystalline schists and giving in particular many local 

details which are beyond the scope of this work, he says of the clay slates that they 

constitute the uppermost divi'3ion of the Archean, are of general occurrence, and rest 

as a rule upon crystalline schists, but in part upon the gneiss and also directly upon 

the granite. From these relations it is apparent that the clay slates are distinguished 

from the other rocks of Sievers's Archean by an unconformity. The compilers of the 

map of North America have endeavored to maintain the distinction which appears 

on Sievers's map and have mapped the clay slates and the underlying crystalline 

rocks as separate divisions, assigning the former to the metamorphic Paleozoic and 

342 
FIGURE 9.-Sketch "'.ll.ap showing the distribution of Paleozoic rocks that are undivided on the geologic map of North 

America and the key to the references in the text. 

343 
344 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

the latter to the undifferentiated pre-Cambrian. In so doing they have followed 

only the suggestion of the lithologic descriptions, as there is no evidence on which to 

assign either division to a particular geologic age. Sievers states: 

The clay slate is mostly thinly laminated, grayish, brownish to reddish, or bluish to black 

in color, and frequently has the character of roofing slate. It occurs chiefly in the middle zones 

of the Cordillera, from 900 to 3,000 meters, and has an extraordinary development. It is a 

striking fact in the distribution of the clay slate that in the western portion of the mountains 

it occurs chiefly south of the gneissic chain; elsewhere, in the eastern mountains, it occurs 

north of the chain. 

Following these general notes are several pages devoted to the local distribution 

of the clay slate. 

C 20. TRINIDAD. 

The geology of Trinidad was described in 1860 by Wall and Sawkins,S63 geologists of the Geological Survey of Trinidad. Their work appears to have been so 

thorough that it is still the basis of our knowledge of the island. They say in part 

as follows: 

It is proposed to term that series of micaceous slates, sandstones, limestones, and shales 

which are the constituent strata of the northern littoral range of Trinidad the Caribbean group, 

sinee it forms the southern boundary of the Caribbean Sea; and, from reasons to be adduced 

hereafter, probably the littoral chain of Venezuela, partly composed also of mica slates and 

associated rocks, may present a continuation of the same formation. 

The central range comprises an indurated formation of lower Cretaceous age and is apparently a fragment of an immense series which contributes very largely to the Cordillera of northern 

Venezuela. These deposits are perhaps equivalent to the series of strata observed very extensively in New Grenada and other parts of South America, and described as corresponding to the 

Neocomian horizon. However this may be, till further investigation more fully exposes the 

relations of all these deposits, it is well to localize their occurrence; and as this formation was 

first observed on the shores of the gulf which separates the island from the main, it may be 

appropriately associated with the name of that sea, and will be described as the older Parian 

group. 

A considerable proportion of Trinidad is occupied by a series of Tertiary strata, probably 

of Miocene age, but since the precise equivalency i'l not yet established, this series may, for reasons similar to those above stated, be conveniently designated as the newer Parian group. * * * 

The most prevalent beds of the [Caribbean] series consist of mica slates, presenting numerous 

varieties, sometimes appearing as layers of quartzose matter, separated by thin plates of mica; 

at others, merely as repetitions of micaceous laminre with little associated substance, frequently 

possessing extreme hardness and often degenerating into soft micaceous shales. There are 

several localities where peculiar black slates of ambiguous nature occur. On closer examination, 

these seem to be also micaceous schists, the plates of that mineral inclosing pellicles of graphitic 

matter. 

The mica often possesses a peculiar glossy appearance and presents numerous shades of 

white, yellow, green, brown, red, and black. Of these, green occurs >nost frequently, after 

which yellow. 

Some of the schists of finer texture are analogous to clay slates but really consist of smaller 

particles of mica, with finely divided feldspathic matter. 

Quartzose slates frequently occur and, what is rarer, ferriferous slates-that is, foliated 

rocks in which quartz alternates with oxides of iron, characterized sometimes by great regularity, 

but more generally the ferriferous laminre occur at unequal intervals. 

Of sandstones there are a considerable variety, from fine to coarse grained, some externally 

soft and others of the hardest consistency. 
PALEOZOIC UNDIVIDED. 345 

It is not unusual to meet with varieties, especially the coarse grained, in which the mica 

is suffici~:mtly abundant as, by the parallelism of its plates, to communicate a laminar and even 

fissile structure. 

The term quartzite must be understood in this report as implying siliceous strata, whose 

matter exhibits no granular structure but is continuous and yet perfectly distinct from vein or 

segregated quartz. 

Beds of this substance are of common occurrence, generally assuming a vitreous character, 

but in some instances rather that of hornstone. They are intimately associated with the 

sandstones and seem occasionally tv graduate into the latter. 

Shales, which are also numerous, appear sometimes ferruginous or highly carbonaceous, 

often associated with mica, and generally soft. * * * 

Calcareous rocks are represented by two varieties in this series, viz, crystalline limestones 

contained in the slates and alternating with them, and compact limestones, either quite unconnected with the schistose group or only associated with its upper strata. The former occur 

sometimes in massive beds, varying from white to b~ue in color, often with scattered spangles 

of silvery-white mica, and distinguished by decided crystalline structure. Thinner beds of 

similar lithological characters, from a few inches to several feet in thickness, exhibit repeated 

alternations with the slates or shales. 

Calciferous slates are beds of calcareous base, but with a considerable proportion of earthy 

matter and a laminar or schistose structure. 

The Caribbean terrane is much folded and sheared. The report cited contains 

many striking illustrations of the structure. The sequence of the component formations of the group was not satisfactorily made out, and the age, beyond the fact 

that it is pre-Cretaceous, also remains undetermined. 

D 16. NICARAGUA AND HONDURAS. 

The pre-Triassic rocks of Honduras are assigned by Mierisch and Sapper to the 

Paleozoic and are so mapped. Sapper 696 states: 

The occurrence of Paleozoic rocks in southern Central America has not been demonstrated 

with certainty, as it has not boon possible to find fossils in the strata. Nevertheless, it appears 

to be highly probable th:::.t there belong to the Paleozoic those rocks which Mierisch assigned to 

that age, namely, the very steeply dipping limestones, calcareous mica slates, phyllites, clay 

slates, quartzites, talc, gneisses and amphibolites, talcose and chloritic schists of northeastern 

Nicaragua; but whether they belong to the Devonian, Silurian, or Cambrian, as Mierisch thought, 

or may perhaps be of the same age as the Carboniferous terranes of Guatemala, Chiapas, and 

British Honduras, can not be surmised. According to Mierisch the area covered by these 

formations in Uli and Uani, as well as in the mining districts of Concepcion and ElDorado, is 

considerable, although this fact does not appear on his geological map. 

Sapper goes on to mention several localities in Nicaragua and Honduras in 

which he has observed slates, quartzites, conglomerates, and other rocks which are 

mapped as Paleozoic, though without any specific evidence. He says: 

In regard to the age of these rocks I can only suggest an inference.· It seems to me most 

likely on grounds of lithologic similarity that these formations are to be assigned to the Paleozoic, 

along with the slates of the Rio Coco; but it is not impossible that they may be a part, and in 

that case the lower part, of the Tegucigalpa formation [Triassic]. 

E 19. SANTO DOMINGO AND PORTO RICO. 

Hill 444 makes the following statement with regard to Santo Domingo: 

In general, the geology of the island is similar to that of Cuba and Jamaica, more especially 

the eastern ends, being composed of four principal formations-the older mountain rocks, of 
346 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Cretaceous and Tertiary age, made up of igneous rocks and clays, mantled by gravels and crystalline limestone; the white limestones, of Tertiary age; recent alluvial formations; and the coast 

limestone of elevated reef rock. No recent volcanic rocks are known. The geology and minerals 

of Santo Domingo have been the subject of special reports by many writers, including three 

American geologists, Messrs. Blake, Gabb, and Marvin. 

The terrane which is mapped as undivided Paleozoic on the island of Santo 

Domingo corresponds to the Sierra group of Gabb, who placed it in the Cretaceous. 

According to his description he collected distinct Cretaceous fossils in the southern 

part of the island, but elsewhere the strata are metamorphosed to such an extent that 

no fossils have been found. In view of the facts that much of the terrane is highly 

metamorphosed and that the discovery of fossils has been limited to the southern 

margin of the uplands, it seems not unreasonable to suppose· that some of the rocks 

may be not only olde1 than Cretaceous but possibly pre-Mesozoic. Were they 

colored as Cretaceous they would naturally be associated with the fossiliferous 

Cretaceous limestone of the West Indies and the adjoining continent. The compilers have therefore distinguished them by placing them in the somewhat indistinct 

class of undivided Paleozoic rocks, including areas of younger strata. That portion 

of the strata in which Cretaceous fossils have been found is mapped as Cretaceous. 

Gabb 352 says: 

No formation older than the secondary era has been found on the island, the oldest group 

being the great mass of slates, conglomerates, and limestones which form its core. These are 

uptilted and broken by numerous intrusive masses of crystalline rocks which may be, for convenience, grouped under the generic term of syenite, since they almost invariably consist of the 

three necessary minerals quartz, feldspar, and hornblende. 

Flanking the slates, etc., of the Sierra there is a broad development of Tertiary marking 

all the northern and a part of the southern side of the island, and this in turn is bordered by a 

more recent deposit of limestones and gravels which I shall call the Coast formation. 

The Sierra group forms all of the great mountain mass of the interior, extending the entire 

length of the Republic. 

It also constitutes the greater part of the Peninsula of Samana and appears as a single 

little outlier, under the Tertiary, near Puerto Plata. It everywhere shows the evidence of 

active subterranean forces, being not only metamorphosed, with hardly a single local exception, 

but is everywhere much uptilted and usually strongly folded. Over much of its area the metamorphic action has been so complete as to destroy the traces of stratification or to so nearly 

obliterate them that they are apt to be confounded with cross fractures. * * * 

But enough of the stratification is preserved to show conclusively that these beds lie in a 

series of east and west folds, the line of folding and upheaval corresponding very closely with 

the axis of the mountains. The thickness of the deposit is very difficult to determine, since 

no continuous section exists, where one can be certain of having all the beds and of not being 

deceived by repetitions. On a very rough estimate, not based on measurements, however, but 

only on the broadest kind of vague generalization in the canyons of the Ocoa and Nigua rivers 

and again on what I saw of the formation in the vicinity of the Pico del Gallo, we might set 

down the total thickness at anywhere between 2,000 and 4,000 feet. It must be understood 

that this broad margin is not the result of want of care in observation but arises from the almost 

absolute impossibility of finding a reliable section. In one region a group of conglomerates 

occurs; in another, within 40 or 50 miles, these same beds are represented by limestone, without 

a pebble; and on the same strike within another 20 miles neither limestone nor conglomerate 

is to be found; all is a semitalcose slate too friable to yield a hand specimen and with no distinguishable stratification. Add to this the partial obliteration of character by different degrees 

of metamorphism, and the sometimes total obliteration of bedding, and the reasons of my cautious 

statement must be sufficiently obvious. 
PALEOZOIC UNDIVIDED. 347 

In the interior of the mountains, especially in the western two-thirds, the disturbance has 

been greatest, and the reason appears in the existence of great masses of eruptive rock which 

have pushed up the slates, broken them, and in some cases penetrated them by dikes to a 

distance of several miles from the parent mass. In some cases pieces of the wall rock are found 

embedded in the syenite; and pebbles one-half syenite and the other half jraspery are not rare. 

In its original state this group of beds seems to have consisted of a series of clay shales, 

thinly bedded, others more heavily bedded and with layers of sandstone, conglomerate, limestone, and heavy-bedded sandstones. The changes produced in these rocks by metamorphism 

are almost infinite. On the Ocoa River the shales are so nearly unaltered that I have repeatedly 

searched in this region in hopes of finding fossils. In the canyon of the river they are gray and 

friable, with an occasional bed of sandstone; farther south they are red and give rise to numerous 

salt springs; still farther south they contain more numerous beds of sandstone and are brown 

and more sandy in texture. These same shales are modified at Recol into a granular greenishblack material resembling an impure serpentine, while on the Nigua they appear as green, gray, 

or brown jaspers with broad conchoidal fractures, gradually changing again within a few miles 

to a more serpentinoid form, to reappear as the same jasper on the Jaina and to again change, 

on the Upper Jaina and in nearly all the mountains eastward, into a whitish rock, more or less 

talcoid and profusely stained with iron. On the north side of the island the modifications of 

the shale are just as great. The sandstones also undergo an equal number of variations, 

appearing of all colors from black or dark-gray sandrock to a white granular quartzite. In 

short, nearly every color is represented, and naturally all degrees of texture, from the coarse 

conglomerate of San Jose de las Matas, or Maniel, to the shale above described. In one place 

only did I find siliceous segregations like the chalk flints, or more probably, like the Corniferous 

limestones of the New York geologists. In the hill just west of Bani the rock is a limestone, 

and in it are numerous streaks, lying in the plane of stratification, of a light-brownish limestone, 

very tough and breaking with an irregular fracture. Near the base of the series, apparently, 

are strata of conglomerate, made up of pebbles very similar to those of the surrounding beds. 

These pebbles seem to have been brought from long distances, since they are almost invariably 

rounded by attrition. They are largest on the upper Ocoa, near Maniel, and on the north flat 

of the range near San Jose de las Matas, but at these points they are rarely more than a few 

inches in diameter. I have endeavored in vain to find the probable source of these pebbles. 

They are certainly not from the adjoining beds, although lithological researches were not wanting. 

They are not derived from any deposit encountered by us on the island, since the conglomerate 

strata extend nearly, if not entirely, to the base of the stratified rocks. It is not probable that 

further examination to the westward, in the yet unknown portions adjoining Haiti, or lying 

within its borders, will develop their origin, since such a discovery would be foretold by increase 

in the size and angularity of the pebbles in that direction. They must therefore have been 

derived from some land then existing, most probably to the north or northwest of the present 

island, but now submerged or destroyed. The conglomerate is variable in its character and the 

changes take place over comparatively limited areas. On the north side it is almost always 

cemented by a coarse-grained red sand, the surfaces of the contained pebbles being stained by 

the ferruginous nature of the matrix. This is the rule where the metamorphosis is not very 

perfect. In one place, west of San Jose, the whole mass is rendered nearly homogeneous in 

texture, the fracture crossing matrix and pebbles· alike. In another, on the Mao River, the 

whole is changed to a dark olive-green, the coloring matter having stained even the interior of 

the pebbles. On the Ocoa some of the conglomerate is cemented by lime instead of sand, and 

in this case the pebbles are not so numerous as to be always in contact. This peculiarity 

gradually changes to the eastward, so that the conglomerate is represented on the Nigua by a 

group of beds, in part pure limestone, in part an impure limestone, containing occasional pebbles. 

This last is the stratum from which fossils were obtained. 

Statements relating to the discovery of fossils of Cretaceous age are given in 

Chapter XV (pp. 642-643). 
348 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

vVith regard to Porto Hico Hill 442 states: 

The mountains are composed largely of black or other dark-colored basic igneous 1·ocks, 

occurring as tuffs, conglomerates, and sills of hornblende andesite, cut by dikes of diorite. 

While these rocks are of volcanic origin, there are nowhere any signs of recent or late geologic 

volcanism, such as craters, unburied lava flows, cinder cones, etc., all original volcanic forms 

of topography having been destroyed by erosion, to which are due the present features of configuration. Besides, much of this volcanic material has been worked over into sediments in 

prehistoric ages and now occurs in well-defined strata. 

Included in this mass of volcanic rocks are two limestone formations, interbedded with 

them and relatively inconspicuous in area. One of these, found on the crest of the island near 

Cayey and Aibonito, is a black bituminous shaly limestone interbedded with the volcanic conglomerate. This calcareous horizon is fully 1,000 feet thick, apparently upholds the crest of the 

Sierra, and weathers into soils noted as the best tobacco lands on the island. The other is a 

light-gray crystalline limestone with Cretaceous fossils (Rudistes). * * * 

The geologic history of the island may be briefly summarized as follows: 

The earliest positive chronology that can be fixed at present is Cretaceous time, when the 

island, in common with the other Great Antilles, was the site of active volcanism, which resulted 

in the piling up of vast heaps of igneous rocks now constituting its mass. 

At the close of Cretaceous time and during the beginning of the Tertiary this volcanic 

material was water sorted and converted into marginal sea sediments, as represented in the 

stratified tuffs, conglomerates, and fossiliferous Cretaceous and Eocene rocks. The history of 

Porto Rico during Oligocene time is obscure, the vast thicknesses of white limestone of that age 

which occur in Cuba, Jamaica, and Santo Domingo not having as yet been detected upon the 

island. It is supposed, however, that the island, together with the other Great Antilles, suffered 

great subsidence during this epoch. 

In late Tertiary time all the aforesaid rocks were uplifted and deformed into their present 

mountainous aspect, in common with the general Antillean uplift of that epoch. The exact 

period of this uplift in the later half of the Tertiary has not as yet been fixed, but it was largely 

accomplished before the close of the Miocene epoch. The tilted Pinones strata of Miocene age, 

at the northwest corner of Porto Rico, clearly show that the movement was not completed until 

after the close of the Miocene. In Pleistocene time the island suffered minor oscillations of 

elevation and subsidence, resulting in the present erosion and configuration of the coast-border 

topography. 

F 17-18. CUBA AND ISLE OF PINES. 

The following notes have been prepared for this volume by T. vV. Vaughan: 

Serpentines, granites, slates, and schists constitute the oldest rocks known on the island of 

Cuba, except perhaps some limestones of doubtful Paleozoic age in the vicinity of Trinidad, and 

form the basement upon which the subsequent geologic formations were deposited. Slates and 

schists occur in small patches in the Province of Santa Clara, some 3 or 4 miles south of the 

city of that name. They are much folded and metamorphosed, and apparently the serpentine 

has been intruded into them. Outcrops of serpentine occur in every province of the island. 

The most westerly occurrence at present known is near Guanajay, in the Province of Pinar del 

Rio. There are large areas in the vicinity of Havana and Guanabacoa, northwest of Matanzas 

between Matanzas and Cardenas, and east of Cardenas in the vicinity of Hato Nuevo. Extensive areas also occur in the central portion of the Province of Santa Clara and near the city of 

'Trinidad in its southern portion. Serpentine also constitutes the surface formation of large 

areas in the northern and central portions of the Provinces of Camaguey and Oriente. 

Outcrops of granite were observed at the south coast of the Province of Oriente and south 

of the city of Santa Clara. A granite porphyry of doubtful age occurs in Oriente Province. 

Semicrystalline blue limestones of fine texture outcropping in the vicinity of Trinidad have 

been considered as doubtfully of Paleozoic age. 
PALEOZOIC UNDIVIDED. 349 

In the Isle of Pines, associated with the Gerona marble which is described below, and to some 

extent interbedded with it, is a great mass of crystalline quartz-mica schist, which rarely reaches 

the surface except in watercourses, as it is nearly everywhere covered by the Malpais gravel. 

Wherever it reaches the surface it is deeply weathered to a soft yellowish micaceous sand. In 

addition to the quartz and mica, some portions of the schist also contain numerous garnets and 

a thoroughly disseminated black mineral, taken to be manganese. The more siliceous portions 

of the schist are banded and resemble a gneiss. There are also numerous veins of quartz, from 

several feet in thickness down to mere stringers. It is evident that these quartz veins and the 

siliceous bands and grains are the sources of the Malpais gravel and of the extensive deposits of 

beach sand surrounding the island. Some portions of the schist are highly siliceous, forming 

essentially a quartzite. In the Cerro Siguanea the rock has been extensively fractured and 

recemented by iron and quartz, rendering it more resistant and thus causing a series of hills of 

harder material to stand above the surrounding areas underlain by softer material. 

A dark-gray diorite schist has been observed in the Cerro Daguilla and doubtless occurs 

elsewhere in the island. It is evidently an intrusive basic rock, probably a diorite which has 

been rendered schistose along with the inclosing formations. It is extremely tough and compact, presenting a high degree of resistance to erosion. Some portions of the rock are rather 

massive, the schistose structure being most highly developed along the margin of the intrusive 

mass. 

The ridges on either side of Nueva Gerona are composed of crystalline marble which is 

known as the Gerona marble. · It is probable that the same material also forms the Sierra 

Pequefia, which is parallel to the Sierra Caballos, lying a few miles to the east; and to judge from 

the topography of the Sierra de Canada, which was seen only at a distance, it is composed of the 

same formation. This marble is everywhere thoroughly crystalline, retaining no trace, so far 

as observed, of the organisms it may originally have held. The greater portion is rather 

coarsely crystalline, although there are some beds of fine white statuary marble. The color 

varies from pure white to dark gray, and in some places there is strongly marked banding. 

Owing to the thoroughly crystalline character of this rock, no evidence was obtained throwing light on its probable age. It can, however, scarcely be younger than Paleozoic. In some 

beds the impurities of the original limestone have recrystallized to form certain silicate minerals, 

chiefly fibrous hornblende. This marble was estimated to be not less than 2,000 feet in 

thickness. 

K 10. KLAMATH MOUNTAINS, OREGON. 

Diller 282 makes the following statement concerning the Paleozoic rocks of the 

Klamath Mountains: 

The Paleozoic sediments ·consist of clay slates, dark siliceous, locally banded slates, and 

greenish slates, interbedded with tuffs and lentils of limestone. Near the contact with granodiorite they are locally metamorphosed into fine-grained mica schist, which usually contains 

characteristic minerals, such as chiastolite and staurolite. * * * 

Measured directly across the strike the area occupied mainly by Paleozoic rocks, both 

sedimentary and igneous, in the Applegate region has a width of nearly 30 miles, in which there 

are four more or less clearly defined belts of limestone containing about 50 masses, most of 

which are located on the accompanying map as quarries or prospects. The largest outcrop is 

not over one-third of a mile in length and 200 feet in thickness. * * * 

The limestones at a number of points are fossiliferous, but the fossils are too poorly preserved to permit definite determination. In two lots * * * corals are abundant, and 

among them E. M. Kindle recognizes with doubt forms that he compares with Favosites nitella 

and Oladopora robusta, as well as a gastropod resembling Loxonema bella. * * * A striking 

feature that occurs locally in some of the limestone ledges of the second belt is the inclosure of 

vesicular volcanic fragments, which indicates that volcanic eruptions occurred in the region at 

the time the limestones were forming. 
350 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

In the third belt of limestone, which outcrops along Kane and Steamboat creeks, the only 

fossils found were fragments of round crinoid stems; the· fourth belt, on Little Applegate River, 

contains both round and pentagonal crinoid stems well preserved. The general absence of 

other fossils from these two belts suggests a difference in age from the Devonian, and it is 

probable that they are either Carboniferous or Triassic. 

K-L 11-12. IDAHO AND SOUTHWESTERN MONTANA. 

The area mapped as Paleozoic in Idaho and southwestern Montana covers the 

mountains on both sides of Salmon River. It is little known geologically. "\Veed, 

Lindgren, and "\Villis have reconnoitered portions of it and furnished the notes on 

which the outlines are sketched. 

K-L 18-19. NEW ENGLAND. 

In New England rocks which were formerly regarded as Archean have been 

shown by the work of B. K. Emerson/19 George Otis Smith,760 E. S. Bastin/1 and 

C. W. Brown to be of Paleozoic age. They are, however, so metamorphosed that 

separation is difficult, and in the zone here mapped as Paleozoic the distinct systems 

are not yet certainly correlated with definite periods . 

. M 9-10, N 8-9. VANCOUVER ISLAND AND QUEEN CHARLOTTE ISLANDS. 

For data on Vancouver and Queen Charlotte Islands, Dawson, Webster, Haycock, and Clapp may be consulted. In 1878 Dawson 252 explored and mapped 

geologically the Queen Charlotte Islands, reporting the discovery of fossils which 

determined the Triassic age of a certain zone of argillites and limestones repeated 

in many sections along different parts of the coast. But he also states his belief 

that "from the intimate association of Carboniferous and Triassic rocks in the 

southern interior of the province, and more particularly from the occurrence of a 

great mass of rocks largely volcanic in origin and believed to be Carboniferous in 

age, in the southern part of Vancouver, it is highly probable that rocks of this 

age may come to the surface in some places." 

In 1885 Dawson 256 examined the northern part of Vancouver Island and stated: 

The geological resemblance between the part of Vancouver Island which is here described 

and the southern half of the Queen Charlotte Islands is extremely close. This resemblance 

had previously been reported on by me in general terms and was indeed to be expected, as 

the Queen Charlotte Islands and Vancouver Island form portions of a single axis of elevation 

which here constitutes the western member of the Cordillera. 

"\Vebster,S68a in his report on the west coast of Vancouver, says: 

In describing the geology I shall use the late Dr. G. :M. Dawson's nomenclature as far 

as possible. * * * In his description the igneous dark-colored trappean rocks with associated mica schists and gneisses are said to be interbedded with argillites and crystalline 

limestones, classed as Triassic on the evidence of the fossils discovered in the argillites and 

named the Vancouver series. On the west coast of Vancouver Island, however, we find the 

igneous rocks piercing and including fragments and masses of the crystalline limestones, just 

as the granites at and near their contact with the traps pierce and include the latter. Nowhere 

did I see clear evidence of the limestones being interbedded with the traps, though in many 

places at first view there is every appearance of their being so. I therefore look upon the 

limestones as being older and unconformable. 
P ALEOZOIO UNDIVIDED. 351 

Haycock 415a adds: 

Dr. Dawson's descriptions of the metamorpmc rocks of the northern and eastern portions 

of the island apply with such exactness to this series of the west coast that there can be no 

reasonable doubt of the latter being a continuation of the former. They may thus be considered 

as belonging to his Vancouver series and mainly of Triassic but possibly in their lower portions 

of Carboniferous age. 

Clapp has described the topography and geology of the southeastern and 

southern portions of Vancouver in two articles based on reconnaissance surveys 

made since 1908. In his earlier report 137 he says: 

The formations exposed in the southern part of Vancouver Island range from the Devonian 

period or older, to the Pleistocene and Recent. * * * 

The Tertiary sediments of the south coast are the youngest consolidated rocks. Rocks 

which when unaltered resemble the Coal :Measures have along certain belts been metamorphosed. 

Metamorphic rocks underlie the greater part of the region. 

The older metamorphic rocks can not be definitely assigned to any one period. A careful 

search for fossils was made in the calcareous rocks, now completely crystallized, but without 

success until the writer's attention was called to the occurrence of fossil corals on the south 

shore of Cowichan Lake. * * * Although the material has not yet. been worked up, the 

fauna undoubtedly belongs to the Devonian period. * * * 

Provisionally, therefore, one can place the great series of old metamorphics in the southeastern part of Vancouver Island as late Middle Paleozoic. 

Dawson and other earlier writers classify the old crystallines which underlie the 'coal 

Measures as the Vancouver series and place them in the Triassic period with possibly some 

Carbonif~rous members. As the evidence for assigning part of this great series of rocksespecially those in the northern part of the island-to the Triassic is indisputable, and as 

Dawson suggests that, should this series eventually prove separable into other formations 

besides the Triassic, the name Vancouver series be retained for the Triassic members, it seems 

best to restrict the term Vancouver series to Triassic rocks of the northern part of the island, 

and to introduce a new term for the older rocks. Hence I suggest the term Victoria series 

as a general name embracing the older metamorphics of the southern part of the island, 

belonging to the Paleozoic era. 

In· his later report, on the southern portion of Vancouver, Clapp 138 says: 

The oldest group of rocks in the southern part of Vancouver Island is the Victoria group. 

This name was proposed by the writer to include the older metamorphic rocks that occur in 

the neighborhood of Victoria and which were assigned to the Paleozoic and provisionally, in 

part, to the Devonian, on the evidence of fossils secured at Cowichan Lake. A later, much 

more complete collection of fossils from the same locality now shows the fauna to be either 

Triassic or Jurassic. The correlation of the formations is still doubtful, but it is probable 

that a large part of the rocks assigned to the Victoria group belongs to an older group of rocks 

than those in which the above fossils occur, and they are still assigned, provisionally, to the 

Paleozoic. 

In view of the uncertainty of age and correlation of the rocks of these islands, 

and because the marine Triassic in the Canadian Cordillera, of which these islands 

are considered a part, is mapped with the Paleozoic undivided, these rocks are 

shown by the Paleozoic pattern on the present map. 

For a description of the Triassic as disclosed in both Vancouver and the Queen 

Charlotte Islands, the reader is referred to M 9-10 and N 8-9, Chapter XII (pp. 

536, 539); for a description of the Lower Cretaceous of the Queen Charlotte group 

to N 8-9, Chapter XIV (pp. 628-630); and for the Tertiary of Graham Island (of 

the Queen Charlotte group) to N 8-9, Chapter XVII (p. 834). 
352 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

M 10-11. WASHINGTON AND BRITISH COLUMBIA, 

Umpleby 825 gives the following account of the geology of the Republic district, Washington, which may be regarded as representative of the Paleozoic and 

later rocks mapped as metamorphic Paleozoic in this region. 

The geologic history of the Republic district has as its great features sedimentation in the 

Paleozoic, erosion with minor volcanism in the Mesozoic, igneous activity and erosion in the 

Tertiary, and continental glaciation in the Quaternary. 

The oldest rocks exposed in the district are the metamorphic equivalents of a great series 

of shales, sandstones, limestones, and lava flows which are of Paleozoic age and are provisionally 

assigned to the Carboniferous. After the deposition of this series the area passed through a 

long period of crustal disturbance which, although not developing sharp folds, metamorphosed 

the beds and raised the area far above sea level. Either during this period of crustal disturbance 

or shortly thereafter great batholithic masses of granodiorite were intruded into the Paleozoic 

senes. 

From the time of the granodiorite intrusions, which are probably of early or middle 

Mesozoic age, to middle Tertiary times there was a great period of erosion which may be 

divided into two parts-a first, during which the entire area was reduced probably to base 

level (Eocene sudace}; and a second which was introduced by decided elevation and during 

which broad valleys at least 2,500 feet deep were developed. 

The next rocks in order of formation are of Oligocene age and occupy one of these broad, 

deep valleys. They are dacite flows, including great quantities of stream gravels. Overlying 

these, unconformably, are andesite breccias, lake beds, and andesite flows, all of which occur 

within the old erosion valley. Next in order of age are intrusive latite porphyries with which 

the ore deposits are thought to be genetically related. 

From the time of the latitic intrusions to the Pleistocene erosion was the dominant process, 

although during this time there was a short period of basaltic eruption. In the Pleistocene 

period the Cordillera ice sheet covered the entire area. 

The oldest known formation exposed in the area is a series of metamorphic rocks including 

slates, schists, quartzites, marbles, and greenstones. It is most extensively developed southwest of Republic, where about 2 square miles are known. East of the San Poil-Curlew valley 

* * * are extensive areas where the metamorphic series is the predominating formation. 

Both areas are so poor in exposures that it is impossible to determine detailed relations. 

The Paleozoic rocks are very uniformly but not intensely metamorphosed. True schists 

are not common, and in many instances the limestone has not been changed to marble. Nevertheless, the series has been so disturbed that a given set of characteristics seldom persists for 

more than a short distance in any direction. Neither bottom nor top of the series was found. 

Black carbonaceous argillite is the predominant rock type, although bluish-gray nonfossiliferous limestones have a wide development. Massive gray quartzites were noted in one 

exposure southwest of Republic. Porphyries of intermediate and basic composition are found 

both as dikes and sills, apparently intruded into the series before its metamorphism. The age 

relations of the various phases of the series are not obvious from studies in the Republic area, 

but to the north, at Phenix, British Columbia, LeRoy a reports a section including all the 

above types of rocks, which he divides into three parts, with an unconformity between the 

upper two. His section places the argillites in the upper part, separated from the limestones 

and tuffs (no tuffs of this age were noted at Republic) by a pronounced unconformity, while 

the lower member is quartzite with intruded dikes and sills of basic porphyrites. The Paleozoic beds are folded and metamorphosed and are in marked contrast with the overlying Tertiary 

series, in which folding is less marked and the beds are not metamorphosed. 

It is not possible, on the strength of facts now known, to assign this formation to a definite 

place in the Paleozoic senes. Near Republic the formation carries certain fossils, not well 

a Bull. Canada Geol. Survey No. 1072, p. 65. 
PALEOZOIC UNDIVIDED. 353 

preserved, but which seem to be crinoid stems. In an exposure of limestone near the top of 

Buckhorn Mountain, in the northwest part of Republic quadrangle, several fossil crinoid stems 

were found which are not out of harmony with a provisional assignment to the Carboniferous. 

These remains, together with the lithologic characteristics of the series, suggest a correlation 

with the Cache Creek series of Dawson, a which is of Carboniferous age. On lithologic grounds, 

however. it is thought that rocks of more than one age are present. 

N 10-11 TO Q 7-9. BRITISH COLUMBIA AND YUKON. 

The large area mapped as Paleozoic in British Columbia and Yukon is so 

assigned on the work of the Canadian Geological Survey and chiefly on that of Dr. 

George M. Dawson. The Cache Creek group is largely represented and is described 

in Chapter VIII (p. 390). But there are in the region also other terranes which can 

not be separated, as the country is largely unknown and the geologic relations are 

intricate. 

0-R 2-8. ALASKA. 

It is probable that the rocks in Alaska mapped as metamorphic Paleozoic 

include strata ranging from pre-Cambrian through the Paleozoic column and may 

possibly include some highly metamorphosed Mesozoic terranes. Adequate differentiation is in part due to limitations imposed by the scale of the map and in part 

to the absence of detailed field data. According to Brooks 828 ·-

Four belts of these younger metamorphic rocks arc indicated on the map. The first 

stretches through southeastern Alaska and probably forms the bedrock throughout the greater 

part of the unexplored St. Elias Range. It has been identified along the lower Copper River 

valley and in the Chugach Mountains, and then, bending to the southwest, forms the backbone 

of the Kenai Peninsula of southeastern Alaska. Silurian,b Devonian, Carboniferous, and 

Lower Cretaceous c fossils have been found in these metamorphic rocks of southeastern 

Alaska.d The metamorphic rocks of what appears to be the western end of the same belt 

have thus far yielded no fossils, and they have been variously assigned to the Paleozoic and 

the Mesozoic.e The intensely folded rocks of the Chugach Mountains may include some 

pre-Cambrian sediments, but of this no evidence has yet been found. 

A second belt of metamorphic rocks forms the major part of the Alaska Range, and Ordovician I fossils have been found at a horizon which probably occurs near the base of this series, 

but it is not impossible that pre-Cambrian sediments are also included. 

a Ann. Rept. Geol. Survey Canada, new ser., vol. 7, 1894, pp. 37B-49B. 

b Brooks, A. H., Preliminary report on the Ketchikan mining district, Alaska: Prof. Paper U. S. Geol. Survey 

No. 1, 1902, pp. 16-31. 

c Wright, C. W., Reconnaissance of Admiralty Island: Bull. U.S. Geol. Survey No. 287, 1906, p. 144. 

dIn 1909 Mesozoic fossils of Jurassic or Cretaceous age were found at Berners Bay by Knopf and identified by 

Knowlton. 

e Russell, I. C., Expedition to Mount St. Elias: Nat. Geog. Mag., vol. 3, 1890, pp. 173-174. Schrader, F. C., A 

reconnaissance of a part of Prince William Sound and the Copper River district in 1898: Twentieth Ann. Rept. U.S. 

Geol. Survey, pt. 7, 1900, pp. 408-410. Schrader, F. C., and Spencer, A. C., The geology and mineral resources of a 

portion of the Copper River district, a special publication of the U. S. Geol. Survey, 1901, pp. 34-37. Mendenhall, 

W. C., A reconnaissance from Resurrection Bay to Tanana River: Twentieth Ann. Rept. U. S. Geol. Survey, pt. 7, 

1900, pp. 265-340. Emerson, B. K., Harriman Alaska Expedition, vol. 4, New York, 1902, pp. 11-54. Martin, G. C., 

The petroleum fields of the Pacific coast of Alaska: Bull. U.S. Geol. Survey No. 250, 1905, p. 64. Mendenhall, W. C., 

The geology of the central Copper River region: Prof. Paper U.S. Geol. Survey No. 41, 1905, p. 133. Paige, S., and 

Knopf, A., Geologic reconnaissance in Matanuska and Talkeetna basins, Alaska, Bull. U. S. Geol. Survey No. 327, 

1907. 

f Brooks, A. H., The Mount McKinley region, Alaska: Prof. Paper U. S. Geol. Survey No. 70, 1911, pp. 72-73. 

48011°--12----23 
354 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

A broad belt of metamorphosed sediments is shown on the map between Yukon and 

Tanana rivers, and in this are known to be Devonian and Carboniferous and probably Silurian a 

horizons.b Here, too, pre-Cambrian beds may be included. 

Schrader c has described a great complex of metamorphic sediments in which Carboniferous fossils have been found near the top of some doubtful Silurian forms in a limestone occurring 

near the bottom. 

Mendenhall,a in his exploration of the Allen and Kobuk rivers, not attempting to differentiate the semicrystalline rocks which he encountered in his rapid journey, grouped them 

together under the term'' metamorphic complex." In this group are included schists of various 

types, limestones, quartzites, and greenstones. The lithology is that of the older terranes of 

other parts of Alaska, but Mendenhall was unable to ascertain the succession within the complex. The group was traced westward to Kotzebue Sound and was regarded by Mendenhall 

in a broad way as the equivalent of the metamorphic terranes of Seward Peninsula. 

In Seward Peninsula the extremely complex structure, the great amount of 

metamorphism, and the lack of detailed investigations have rendered any definite 

statement of the stratigraphy impossible. Schists of different mineralogic composition are intricately associated with recrystallized limestones and basic intrusive 

rocks, all much sheared. In different limestones at widely separated localities 

fossils of Cambrian, Ordovician, Silurian, and Devonian or Carboniferous age have 

been found, although most of the limestones have been too thoroughly recrystallized to afford paleontologic evidence. There is strong probability that preCambrian sediments may also be included, but the lack of definite bedding and the 

known occurrence of continued folds and thrust faults make the projection of dips, 

and thus the interpretation of sequence, inconclusive. 

a Prindle, L. M., Fairbanks and Rampart quadrangles, Yukon-Tanana region, Alaska: Bull. U. S. Geol. Survey 

No. 337, 1908, pp. 18-23. 

b In 1909 Silurian and Ordovician fossils were found in the White }fountains, in the Fairbanks quadrangle, by 

Prindle and identified by Ulrich. 

c Schrader, F. C., Reconnaissance in northern Alaska: Prof. Paper U.S. Geol. Survey No. 20, 1904, pp. 55-72. 

d Mendenhall, W. C., A reconnaissance from Fort Hamlin to Kotzebue Sound: Prof. Paper U.S. Geol. Survey 

No. 10, 1902, pp. 31-36. 
CHAPTER VIII. 

CARBONIFEROUS UNDIVIDEDo 

Color, light blue, horizontal ruling. 

Symbol, 14. 

Distribution: ·western North America, Arctic region, Newfoundland, and Central America. 

Subdivided into Mississippian, Pennsylvanian, and Permian in eastern North America. 

(See fig. 10.) 

Content: Mississippian and Pennsylvanian limestones of the Cordillera including Devonian 

where present; Mankomen formation and K abesna limestone of Alaska; Lisburne formation, Alaska; Carboniferous of the Parry Archipelago, Arctic region; Carboniferous of 

Newfoundland; doubtful Carboniferous or Devonian of Honduras. 

Areas mapped as Carboniferous 1mdivided. 

Pa,ge. 

E 16 ........................... British Honduras......................................................... 355 

H-I 12 ....................... Southern Arizona......................................................... 357 

H-I 13 ....................... Trans-Pecos Texas........................................................ 358 

I 12 .......................... Arizona and northwestern New Mexico..................................... 361 

I 13 0 ••••••••••••••••••••••••• New Mexico ....................... o • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 362 

I 16 .......................... Alabama (not mapped).................................................... 363 

J 10 .......................... Sierra Nevada, California .................. 0. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 363 

J 11 .......................... Eastern Nevada . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364 

J 12 .......................... Southern Utah and northern Arizona....................................... 366 

J 13 .......................... Colorado .. 0 0 • 0 ••••••••••••••••••••• 0 • 0 •• 0 0 • 0 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 367 

J-L 13 ........................ Wyoming, northern Colorado, and South Dakota............................ 372 

K 10 ......................... Klamath Mountains, California............................................. 373 

K 11. ........................ ~evada. (See J 11 and K 12.) 

K 12 ......................... Wasatch and Uinta ranges................................................. 376 

L 11. ......................... Blue Mountains, Oregon................................................... 380 

L 12 .......................... Western Montana......................................................... 381 

L 19-20 ....................... New Brunswick (Mississippian and Pennsylvanian mapped separately) ...... 0 383 

L 20 .......................... Nova Scotia and adjacent parts of ~ew Brunswick (Mississippian, Pennsylvanian, and Permian mapped separately)................................ 384 

L-M 11-12 .................... Western Montana and northern Wyoming................................... 386 

M 11. ........................ Front Range, Rocky Mountains of Alberta.................................. 388 

1\f 21 ............. , ........... Newfoundland ... 0 0 0 ••• 0 0 o •• 0 0 0 0 •••• o 0 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 889 

M-P 8-lla .................... Rocky Mountains of British Columbia...................................... 390 

N -0 8-9 ...................... Southeastern Alask<t ... 0 • 0 0 •• 0 •••• 0 • 0 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 392 

P 6-7 ......................... Northern base of St. Elias Range and White River basin, Alaska and Yukon 

Territory .... 0 0 ..... 0 .... 0 .................................. 0 ••••••• 0. • • 394 

Q 3 ............................ Seward Peninsula, Alaska ..................... '........................... 395 

Q 7 ............................ Upper Yukon and Porcupine rivers, Alaska ..... 0........................... 395 

R 3 ............................. Cape Lisburne and Cape Thompson, northwestern Alaska.................... 396 

R 5 ........................... Endicott Range, Alaska........................ .. .. . .. .. . .. .. .. . . . . . .. .. 399 

S-T 10-14, T 15, U 17-20 ...... Baring (or Banks) Land, Parry Islands, Ellesmere Land, and Grinnell Land.. 399 

E 16. BRITISH liONDURAS. 

Sapper 698 in 1899 compiled the available information concerning the geology 

of British Honduras, or Belize. The map of that region as furnished by the Mexican 

Survey in 1906 follows his reconnaissance map of 1899. The Carboniferous and the ---·-·-··-------

aM 10-11, N 10-11, 0 9-10, and P 8-9 in general mapped with Paleozoic undivided. 

355 
FIGURE 10.-Sketch map showing the distribution of Carboniferous rocks that are undivided on the geologic map 

356 

of North America and the key to references in the text. 
CARBONIFEROUS {;~DIVIDED. 357 

eruptive rocks constitute the Coxcomb Mountains, which have been crossed by 

Cockburn, Fowler, Wilson, and Sapper. Sapper's notes contain repeated references 

to phyllite clay slate and crinoidallimestones. Regarding the latter he says: 

Although the crinoidallimestones do not afford definite data for the determination of age, 

since the crinoids are not specifically determinable, it is nevertheless most likely that the limestone is Carboniferous, since it is only in this terrane thai; crinoidal limestones have thus far 

been found in Guatemala. 

Crinoids are mentioned also as occurring in a graywacke. 

Since the position of these slates and associated limestones within the Carboniferous is not definitely determined, the terrane is mapped as undivided Carboniferous, 

but it is highly probable that the strata are of the same age as those of adjacent 

areas in Guatemala, which, as stated in Chapter X (p. 425), are regarded by Girty 

as not older than lower Pennsylvanian or uppermost Mississippian. 

H-I 12. SOUTHERN ARIZONA. 

Several isolated sections of Carboniferous strata in southern Arizona are 

described by Ransome and Lindgren, and in the failure of exact equivalency they 

are given local formation names: "Globe limestone" of the Globe district (upper 

part only is Carboniferous), Escabrosa and Naco limestones of the Bisbee district, 

and Modoc and Tule Spring limestones of the Clifton district. 

The "Globe limestone" consists almost exclusively of limestone in beds ranging 

from 1 to 6 feet in thickness and attains a maximum of 700 feet. It rests without 

angular unconformity upon the Apache group (Cambrian?), and is cut off at the 

top by a plane of erosion. Ransome 657 b states: 

It appears from the Pinto Creek sections that the Globe formation includes in its lower 

part at least 300 feet of Devonian strata and in its upper part at least 500 feet of Upper Carboniferous beds. No unconformity, however, has been found between the beds belonging to 

these different periods. While future work in the broader region about the Globe quadrangle 

may result in the discovery of such an interruption of sedimentation and in the consequent 

splitting up of the Globe limestone, it is believed that no such division is at present practicable 

within the area covered by this report. [a] 

The case of the Globe limestone recalls that of the Ouray limestone in Colorado, to which 

Cross has recently called attention. The Ouray limestone, an apparent stratigraphical unit 

containing characteristic Devonian fossils, was at first referred wholly to that period. Later 

work, however, has resulted in the discovery of Lower Carboniferous fossils in the upper part 

of this limestone unit. There is nothing as yet known that precludes the presence of Lower 

Carboniferous beds in the Globe limestone between the.known fossiliferous Upper Carboniferous 

and the known fossiliferous Devonian. The absence of any recognizable unconformity within 

the mass of limestone strata is suggestive of uninterrupted deposition from the Devonian to 

the Upper Carboniferous, and consequently of the presence of some Lower Carboniferous or 

Mississippian. The paleontological note furnished by Dr. Girty also intimates that the Lower 

Carboniferous may be represented. 

The Escabrosa and Naco formations are Carboniferous limestones of the Bisbee 

district, Arizona, the former having a thickness of 700 feet and representing the 

Mississippian series, the latter being 3,000 feet or more thick and equivalent to 

the Pennsylvanian (Aubrey group and Redwall limestone of northern Arizona in 

a As a result of recent work in the Ray quadrangle, which adjoins the Globe quadrangle, Ransome has separated 

the Carboniferous from the Devonian. See Min. and Sci. Press, vol. 102, 1911, p. 747.-B. W. 
358 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

part, according to G. H. Girty). The Escabrosa succeeds the Martin limestone 

(Devonian) apparently conformably; it is in turn conformably succeeded by the 

Naco; and the section ends at the top in a surface of pre-Cretaceous erosion.6580 

The Modoc limestone (Clifton district) is a remnant of the Mississippian series, 

about 170 feet thick, which rests conformably upon the Morenci formation (Devonian?), and is limited above by a surface of erosion. The Tule Spring limestone is 

a representative of both the Mississippian and the Pennsylvanian series. 541 b 

H-I 13. 'I'RANS-PECOS TEXAS. 

With reference to the Carboniferous in trans-Pecos Texas Richardson 6680 

states: 

The Hueco limestone outcrops in an area of several hundred square miles in trans-Pecos 

Texas. It underlies the Diablo Plateau, a large area between the El Paso and Van Horn 

quadrangles, and outcrops in the Sierra Diablo, Finlay, Hueco, and Franklin mountains. The 

Hueco is a rather homogeneous gray limestone, generally massive, though in places it is thinbedded. It is comparatively free from chert and differs from the limestones of Silurian and 

Ordovician age in that it contains little or no magnesia. Although the limestone is prevailingly 

gray, there are local variations in color from light gray to almost black.· 

In the Franklin and Hueco mountains the Hueco limestone immediately overlies the 

Fusselman limestone, apparently conformably, in spite of the fact of the great hiatus indicated 

by their ages. But in the Van Horn region a well-developed basal conglomerate averaging 

approximately 100 feet in thickness and composed of pebbles of all the pre-Carboniferous 

formations is present at the base of the limestone, which rests with marked irregularity on 

the underlying formation. The Hueco limestone generally is overlain by Pleistocene debris, 

but in a few areas, notably in the Finlay mountains and also 8 miles northwest of Van Horn, 

it is directly overlain by Cretaceous strata. The total thickness of the Hueco limestone has not 

yet been determined, but it is more than 3,000 feet. 

The Hueco limestone carries an abundant fauna of Pennsylvanian age. * * * According to Dr. Girty, this fauna with some modifications is similar to that found over much of the 

Cordilleran region, and the Hueco limestone is tentatively correlated with the Aubrey formation 

and the Weber quartzite.a 

In the Van Horn quadrangle and north of it the bolson plain known as Salt Flat, which 

is occupied by an unknown depth of unconsolidated Quaternary deposits, lies between the 

Sierra D1ablo on the west and the Guadalupe-Delaware Mountains on the east and completely 

conceals the relations of the rocks in the two mountains. As has been stated, the Sierra Diablo 

is made up of the Hueco limestone, the stratigraphic top of which has not been observed, and 

the Guadalupe-Delaware Mountains are composed of Paleozoic strata, younger than the Pennsylvanian, which contain a fauna not elsewhere known in North America, that Girty has named 

Guadalupian. This fauna, which has Permian affiliations, is described by Dr. Girty in a paper 

now in press,b and it is intended here only to outline the stratigraphy of these rocks, which 

complete the long Paleozoic sequence of trans-Pecos Texas. 

The Delaware Mountain formation includes a varying mass of sandstone and limestone 

having a maximum thickness of at least 2,300 feet, but the base of the formation is not exposed 

in Texas and has not been determined. In the northern part of the Guadalupe-Delaware 

Mountain uplift, the formation is prevailingly sandy and contains only thin beds and lenses of 

limestone. Southward the sandstone decreases and the limestone increases in amount until, 

in the southern part of the main Delaware Mountains, the formation consists of gray limestone 

a Proc. Washington Acad. Sci., vol. 7, 1905, p. 14. 

b Sinre published as Prof. Paper TI. S. GeoL Survey No. 58, 1908.-B. W. 
CARBONIFEROUS UNDIVIDED, 359 

with only subordinate beds and lenses of sandstone. The sandstone is a massive to thin bedded 

buff to brownish quartzose rock and the limestone likewise is both thick and thin bedded, of a 

prevailing gray color, and contains little chert. * * * 

In the Guadalupe Mountains, 60 miles north of Van Horn, about 2,200 feet of the Delaware 

Mountain formation is conformably overlain, in a magnificently exposed section, by 1,800 feet 

of limestone named the Capitan limestone. The name is taken from El Capitan Peak, which, 

having an elevation of 8,690 feet, is the highest point in Texas. The Capitan is a light-colored, 

usually white limestone which, although possessing minor variations, is homogeneous in general 

appearance. Bedding planes in many places are not apparent and the rock is characteristically massive. Chemically it is of variable composition, some analyses showing the presence 

of considerable magnesium while others indicate its almost complete absence. Besides its 

main occurrence in the Guadalupe Mountains the Capitan limestone was determined in 1907 

to be present in the southern end of the Delaware Mountains, where it has been faulted down 

and adjoins the limestone of the Delaware Mountain formation. ll. S. Tarr reports,a in the 

paper cited above, the presence of 1,000 feet or more of sandstone lying above the Capitan 

formation, but these rocks have not been studied, so that neither the base nor the top of the 

strata bearing the Guadalupian fauna has yet been determined. It is expected that these 

relations can be determined in the northward continuation of the formations in the Sacramento 

Mountains of New Mexico. 

The age of the Guadalupian fauna has been much discussed. Girty tentatively regarded the Guadalupe group as younger than the lower portion of the 

Kansas Permian, from which alone invertebrate fossils were known. This view 

was based on the close faunal relationship of the Kansas Permian with the Kansas 

Pennsylvanian, on the general resemblance to the Pennsylvanian shown by the 

fauna of the Hueco limestone, which underlies the Guadalupe group, and on the 

great unlikeness of the Guadalupian fauna both to the fauna of the Hueco limestone and to that of the Pennsylvanian and Permian of Kansas. Subsequent 

investigations, however, have seemed to indicate, as noted below, that the 

striking peculiarity of the Guadalupian fauna is only regional. Furthermore, J. W. 

Beede has reached the conclusion, on stratigraphic and paleontologic evidence not 

altogether satisfactory, that the lower part of the Capitan limestone, which is the 

upper formation of the Guadalupe group, is equivalent to the lower part of the 

Kansas Permian; that the upper part of the Capitan is equivalent to the middle 

part of the Kansas Permian; and that the upper part of the Kansas Permian ( equivalent to the Greer and Quartermaster formations of Oklahoma and Texas) overlies 

the Capitan limestone. The lower formation of the Guadalupe group (the Delaware 

Mountain) he correlates with the Pennsylvanian of Kansas, while the still older 

Hueco limestone is inferentially of early Pennsylvanian (Pottsville?) age. 

In 1909 Richardson 670b traced the Guadalupe group from the type locality 

in Texas northward in New :Mexico for 50 miles and found that the stratigraphy 

is varied and that both the Delaware Mountain formation and the Capitan limestone lose their individuality when traced far along the strike. The northward 

continuation of the group lies between the Pennsylvanian Hueco formation, as 

developed in the Sacramento Mountains, and the Permian red beds of Pecos Valley. 

The fossils in the northward continuation of the Guadalupe group, according to 

Dr. Girty, 3

n

7 show but little relationship to the typical Guadalupian fauna but 

a Tarr, R S., Reconnaissance of the Guadalupe Mountains: Bull. Texas Geol. Survey No.3, 1892. 
360 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

rather are similar to those of the upper part of the Hueco formation. It seems 

probable that this difference in the fauna is due to changed environment, which 

is indicated by the varied lithology. Whether the Guadalupian fauna should be 

regarded as late Pennsylvanian or Permian is still an open question, but the 

weight of evidence is in favor of the Permian and that view has been adopted 

by the United States Geological Survey. 

In an earlier report Richardson 666 described the formations overlying the 

Guadalupe group, as follows: 

The Castile gypsum is a massive white granular variety. It is comparatively pure, and a 

characteristic sample analyzed qualitatively by Mr. W. T. Schaller shows it to be of no unusual 

composition. Considering its great extent the Castile gypsum is remarkably homogeneous, 

yet it varies somewhat. On the surface it is generally disintegrated and earthy. In places it 

is grayish or dark in color owing to the presence of organic matter, and at other places it is 

stained red by iron oxide. Locally selenite is abundant. Some sections show occasional thin 

beds of banded gray limestone in the gypsum. Deposits of native sulphur are also associated 

with the Castile gypsum. The thickness is not known, but it is considerable. A well at the 

old sulphur works about 6 miles north of Rustler Spring shows a thickness there of a little over 

300 feet, though the base of the gypsum is not known to have been reached. 

* * * * * * * * * 

The Castile gypsum outcrops in a belt between the Delaware Mountains and Rustler Hills, 

the width of which averages about 15 miles, though at theN ew Mexico-Texas boundary it is about 

30 miles. This gypsum belt begins about 15 miles north of the railroad and extends into New 

Mexico. Within Texas the gypsum outcrops over 600 square miles. The name of the formation is derived from Castile Spring, which is in the midst of the gypsum about 12 miles south 

of the State boundary. 

The Castile gypsum along its western outcrop lies on little knolls and valleys of the underlying Delaware Mountain formation, indicating an erosional unconformity. Another evidence 

of unconformity at the base of the gypsum consists in the absence of the Capitan limestone. It 

appears that either the gypsum was deposited at or near the top of the Delaware Mountain 

formation as a lens which did not extend westward to intervene between the Delaware Mountain 

formation and the Capitan limestone in the Guadalupe Mountains, or that erosion removed 

the former southwestward extension of the limestone (the thickness of which is unknown) before 

the deposition of the gypsum. The former supposition necessitates the correlation of the 

Rustler formation, which overlies the gypsum, with the upper part of the Delaware Mountain 

formation or with the Capitan limestone. But there is little to support this interpretation, and 

it is tentatively assumed that the Castile gypsum and the Rustler formation were formed after 

the deposition and erosion of a part of the Capitan limestone. 

The Rustler formati.on consists of a fine-textured white magnesian limestone and less 

abundant sandstone. The formation occurs in the Rustler Hills, in the dissected southwestern 

extension of the Rustler Hills between Cottonwood and Hurd's Pass draws, and i.n a few isolated 

areas west of the hills. 

The formation as here exposed averages about 200 feet in thickness and varies in composition. In the southern outcrops there is no sandstone and the hills are capped by about 150 feet 

of massive gray limestone, which directly overlies the gypsum. Northward sandstone is present 

below the limestone. * * * 

Recent work 670 has shown that the Castile gypsum and Rustler formation 

are parts of the group of red beds of Pecos Valley, which are of Permian age. 
CARBONIFEROUS UNDIVIDED. 361 

I 12. ARIZONA AND NORTHWESTERN NEW MEXICO. 

Reagan 663a states in regard to the Carboniferous of the Fort Apache region, 

in Arizona: 

Lower Redwall group.-The first series above the Devonian is from 400 to 1,000 feet of 

alternating gray limestone and shale. It terminates at the top in a massive to shaly coarse 

sandrock, often of the millstone grit type. The lime rocks are very fossiliferous from the middle 

of the series to the top and seem to belong to the lower Carboniferous group; but as yet the 

writer has not identified fossils enough from the group to verify such a conclusion. 

Upper Redwall group.-The writer has included in this group all of the strata superimposed on the millstone grit rock of the group just described, to and including the dark-gray 

limestone series about 1,000 feet above its base. The series here is very variable, indicating 

a rapid transformation from west to east. Ripple marks and old shore lines are noticeable 

and indications of large swamp land areas are exposed on Cibicu Creek and in the vicinity of 

Fort Apache. As evidence that the country reached the swamp stage the writer found several 

specimens of Lepidodendron and one whole tree of the species Calamites cann<eformis. The group 

belongs to the coal-measure series, as is attested by its fossils: Spirifer cameratus, Productus 

semireticulatus, P. costatus, Lepidodendron, Calamites cann<eformis, etc. 

Aubrey group.-The interstream spaces of all the streams in their upper course, as well 

as the south front of the Mogollon Range and the Cibicu divide, where not covered with later 

deposits, are capped with 280 feet of calcareous sandstone followed by 500 feet of soft red and 

gray shales, interrupted by sectile limestone. The Aubrey limestone occurs in one localityat the headwaters of the Cibicu and Canyon creeks. The rocks of this group are usually nonfossiliferous, but fossils enough were obtained (Athyris subtilita, Productus punctatus, Spirifer 

cameratus, Productus, and Bellerophon) to identify it as upper Carboniferous. 

The Zuni Plateau lies just north of the thirty-fifth parallel in New Mexico. 

It is composed largely of Carboniferous strata, which Dutton aorb discusses and 

compares as follows: 

The Carboniferous strata of the plateau country have been divided into two portions, an 

upper and lower. To the lower portion the local name of the "Redwall group" has been given 

and the upper portion has been named the" Aubrey group." The Redwall takes its name from 

the great vertical escarpments which its most massive member presents in the canyons of the 

Colorado. In the Grand and Marble canyons especially a band of limestone from 800 to 900 

feet thick constitutes the face of the principal vertical cliff and becomes the most impressive 

stratigraphic feature of those great chasms. It has always been spoken of as the Red Wall. 

Its lower Carboniferous age has been well ascertained. Above and below it are numerous 

bands of limestone and calcareous sandstones belonging to the same group and always classed 

with it. While it is always found at the exposures of its proper horizon in the other parts 

of the plateau country, it is plainly wanting in the district we are about to study, and its 

absence is certainly a striking fact. It appears to be absent also from the Nacimiento Range, 

northeast of the Zuni Plateau, where the upper Carboniferous rests on the Archean just as it 

does here. In southern and southwestern Colorado, however, it is usually found in its proper 

place. The conclusion seems obvious that it was never deposited here, and that this locality 

was a land area in early Carboniferous time. 

The upper Carboniferous or Aubrey group is usually subdivided into two portions, an 

upper and a lower Aubrey. This subdivision is quite proper as well as convenient, for the 

two portions are strongly contrasted with each other in their lithologic features and in the 

topography to which their erosion has given origin. The lower Aubrey consists of bright-red 

sandstones throughout, deposited usually in rather thick and less frequently in moderately 

thin layers. They are much alike in all outward respects, color, texture, and grouping and in 

the erosional forms sculptured out of them. They are very fine grained, without traces of 

conglomerate or coarse shingle or gravels, and, having a calcareous cement, they weather easily 
362 INDEX 'I'O 'fHE STRATIGRAPHY OF NORTH AMERICA. 

and break down into very fine red sand. Foss]s are scarce but may be found here and there 

in sufficient quantity and distinctness to identify their age. These fossils, so far as I have 

seen, are the same as those which abound in the beds above them. 

The upper Aubrey is composed largely of sandstones, but they have a very different aspect 

from those below. In color they are yellowish brown and the cement, instead of being calcareous, is siliceous-in fact, a regular chert. * * * These sandstones are conspicuously 

cross-bedded, and the silicification of the rock has in no way obscured it. * * * There are 

several bands of these adamantine sandstones, and intercalated with them are three or four 

thick beds of pure limestone, containing an abundance of fossils of many and characteristic 

species. 

While the Mesozoic strata of this district show some differences in compari~on with those 

north of the Grand Canyon, the upper Aubrey shows none, except in its thickness. Its cliffs 

in the upper wall of the Grand Canyon and those overlooking the granite of the Zuni Plateau 

are so similar that it is hardly possible to doubt that their materials came· from the same source 

and were deposited under the same conditions. In the former locality they are thicker in about 

the ratio of 5 to 3, and this ratio holds good not only for the Aubrey series as a whole but for 

all its subdivisions and principal members. In the Grand Canyon the thickness of the Aubrey 

is about 2,000 feet; here it is about 1,200. 

I 13. NEW MEXICO. 

Lindgren 542d describes the Carboniferous of New Mexico as follows: 

The Mississippian, or lower Carboniferous, has been recognized at several place~ south of 

latitude 34°. W. T. Lee found limestone of this age in the Ladrones Range and Gordon 

believes, on the basis of evidence collected by C. L. Herrick, .that the lower part of the section 

in the Magdalena Mountains belongs to this series. Characteristic Mississippian faunas were 

found by Gordon at Kingston and Hillsboro, and the horizon has for some time been known to 

be represented at Lake Valley, where a thickness of over 200 feet of limestone has been measured. Rocks of the same age are also present in the Silver City district. Gordon states that 

at Hillsboro these limestones rest upon the eroded surface of the Devonian calcareous shales, 

but farther west there is no evidence of unconformity. 

The Pennsylvanian, or upper Carboniferous, is deposited with a considerable thickness 

over the whole Territory and reaches its maximum in the country between Santa Fe and Las 

Vegas. As far south as the latitude of Socorro the Pennsylvanian consists in large part of 

sandstones and shales in repeated alternation with some limestone beds. But south of this 

line the pure limestones prevail and at the same time the total thickness appears to diminish. 

Everything indicates near-shore conditions in the northern part of the Territory, where some 

land areas probably existed even at that time. 

In northern and central ~ ew Mexico there appear to be two divisions of the Pennsylvanian, 

the upper in certain parts possibly including the Permian. According to W. T. Lee and C. H. 

Gordon a the Pennsylvanian of central New Mexico is divisible into two groups, the lower called 

the Magdalena group and the upper called the Manzano group. The Manzano consists in fact 

of the "Red Beds" of Carboniferous age. 

The average thickness of the Magdalena group in the vicinity of Socorro is 1,500 feet. 

This group is subdivided into (1) a lower formation called the Sandia, consisting chiefly of 

shales, limestones, and sandstones, the first two predominating, with a thickness ranging from 

500 to .700 feet; and (2) an upper formation called the Madera limestone, 300 to 500 feet thick, 

consisting of blue limestone with some shale. Both formations are well exposed in Socorro and 

Bernalillo counties. 

The Manzano group, best exposed on the east side of the Rio Grande near Socorro, consists 

of 2,000 feet of red and variegated sandstones, shales, limestones, and gypsiferous beds. Its 

a Gordon, C. H., Note on the Pennsylvanian formations in the Rio Grande valley: Jour. Geology, vol. 15, 1907, 

pp. 805-816. Lee, W. T., and Girty, G. H., The Manzano group of the Rio Grande valley, New Mexico: Bull. U. S. 

Geol. Survey No. 389, 19090 
CARBONIFEROUS UNDIVIDED. 36B 

upper part is a bed of blue limestone 300 to 500 feet thick, with Pennsylvanian fossils, which 

Lee has named the San Andreas limestone. Beneath this is the Yeso formation, consisting of 

500 to 1,000 feet of yellow, pink, and white sandstones and shales, with gypsum and some 

limestone. The basal formation of the Manzano group, to which the name Abo sandstone has 

been given, is composed of dark-red sandstones interstratified with sandy shales. There are 

distinct unconformities produced by erosion at the top and the bottom of the Manzano group. 

South of Socorro County Lee has traced the red beds of the ::\Lanzano group down to Rincon. 

In the Franklin Mountains, according to G. B. Richardson, the Carboniferous "Red Beds" and 

in faet all "Red Beds" are absent and the Pennsylvanian is represented by the Hueco limestone, 

3,000 feet thick. Still farther east on the boundary line between Texas and New Mexico the 

Hueco is covered by 2,500 feet of Guadalupian a sandstone and limestone. Near Silver City and 

in the southwest corner of the Territory the Pennsylvanian consists almost exclusively of limestones of moderate thickness. The "Red Beds" are absent and Cretaceous rocks carrying 

Benton fossils rest with distinct unconformity on the eroded Carboniferous formations. 

In the Zuni Mountains, according to Dutton, there are 1,650 feet of Pennsylvanian and 

Permian "Red Beds" resting directly on the pre-Cambrian rocks. In the Mora uplifts there 

are, according to J. J. Stevenson, 3,276 fpet of upper Carboniferous, consisting of sandstones, 

shales, and limestones in rapid alternation. In the upper Pecos Valley, above Pecos, there is, 

according to Lindgren, about 4,000 feet of the same series which apparently can not be further 

divided. At neither place does this series comprise any "Red Beds." Several coal seams, at 

least one of which is workable, are present. Between Pecos and Glorieta, the relations being 

especially well exposed in La Cueva Creek, this lower series is covered by a thick niass of "Red 

Beds" and coarse grits, containing some interbedded limestone, evidently of Paleozoic age. 

These coarse grits are beyond doubt derived from the pre-Cambrian mass of Thompson and 

Penacho peaks, just to the northwest, and their extensive development demonstrates the 

existence of a land area along the Santa Fe Range and probably also an epoch of erosion within 

Pennsylvanian time .. Above these grits and "Red Beds" are similar strata of uncertain age 

which underlie .the Glorieta Mesa and which are capped by a yellow sandstone, outcropping at 

the edge of the escarpment; the sandstone has been regarded as of Dakota age. The total 

thickness of the "Red Beds" in the upper Pecos Valley, as measured by Newberry, is 1,350 feet. 

I 16. ALABAMA. 

Plant remains, probably of Carboniferous age, are recorded by Smith 747 from 

the metamorphosed rocks near Moseley (now Erin), in Clay County, Ala., which 

have been regarded as a part of the Ocoee group of Safford. (See Chapter III, 

p. 90.) 

J 10. SIERRA NEVADA, CALIFORNIA. 

On pages 373-376 is given an account of the Carboniferous of northern California. 

South of the fortieth parallel in the Sierra Nevada occur schists, slates, quartzites, 

and limestones, which constitute a metamorphic series not usually divisible and 

which under the name Calaveras formation are assigned to the Carboniferous. In 

the "Description of the gold belt" included in folios of the Geologic Atlas of the 

United States relating to the Sierra Nevada 813 published prior to 1900 occurs the 

following statement: 

The great mass of the Paleozoic sediments of the gold belt consists of quartzite, mica 

schist, sandstone, and clay slate, with occasional limestone lenses. On the maps of the gold 

belt these sediments are grouped under two formations: 

. a Richardson, G. B., Paleozoic formations in trans-Pecos Texas: Am. Jour. Sci., 4th ser., vol. 25, June, 1908. 

• 
364 INDEX TO THE STRATIGRAPHY OF NORTH .A.l\1ERICA. 

The Robinson formation, comprising sediments and trachytic tuffs. This contains fossils 

showing the age to be upper Carboniferous. The formation is known on the gold belt series 

of maps only in the Downieville quadrangle, a short distance south of the fortieth parallel. 

The Calaveras formation, comprising by far the largest portion of the Paleozoic sediments 

of the gold belt. Rounded crinoid stems, corals (Lithostrotion and Clisiophyllum), Foraminifera (Fusulina), and bivalves have been found in the limestone lenses and indicate that a considerable portion at least of this formation belongs to the middle or lower Carboniferous. In 

extensive areas of the Calaveras formation no fossils have, however, been found, and older 

rocks may be present in these. It is not likely that post-Carboniferous rocks are present in 

these nonfossiliferous areas. 

In the Colfax quadrangle, which lies in the northern-central part of the Sierra 

Nevada (latitude 39°-39° 30', longitude 120° 30'-121 °), the sedimentary rocks of the 

''Bedrock series'' are divided by Lindgren 538 into three ''groups,'' of which the oldest 

is "the Carboniferous group equivalent to the Calaveras formation of other folios. 

* * * This group can be subdivided into five formations, lithologically very 

distinct, though the fossils do not afford data for paleontologic discrimination. 

These are enumerated from east to west as follows: Blue Canyon formation, Relief 

quartzite, Cape Horn slates, Delhi formation, and Clipper Gap formation." 

According to Lindgren the principal Carboniferous area in the quadrangle is 

that of his Blue Canyon formation, occupying the southeast corner, adjacent to 

''Jura-Trias" (Sailor Canyon) rocks, and intruded by granite. The rocks are black 

fissile clay slates and fine-grained quartzitic sandstones, with one occurrence of fine 

conglomerate and a few limestone lenses. At two localities these limestones contain fossils (Lithostrotion, A viculipecten, a lamellibranch, and Murchisonia at one 

place; Syringopora, Diphyphyllum or Lithostrotion, and crinoid stems at the other). 

These suffice only to indicate a Paleozoic age. 

Lindgren described his Relief formation as a very hard, fine-grained quartzite, 

alternating with streaks of siliceous clay slates, plainly exhibiting the stratification 

but unfossiliferous; his Cape Horn formation as consisting of typical clay slates, 

fissile, almost black, weathering to gray, and containing small limestone lenses which 

have yielded round crinoid stems of Paleozoic age; and his Delhi formation as composed of a peculiar dark-brown or black hard rock, resembling hornfels (a character 

probably due to metamorphism of siliceous sediments of a certain kind), with a few 

lenticular masses of limestone and round crinoid stems. 

Lindgren's Clipper Gap formation consists of black clay slates and argillaceous 

sandstones. Lenticular bodies of limestone are abundant and chert is common. 

Obscure fossils (Phillipsastrea and Pleurotomaria) were obtained at one locality, and 

others ( Clisiophyllum gabbi Meek, Lithostrotion whitneyi, and brachiopod fragments) of lower Carboniferous age were found in a disconnected mass that is 

probably a fragment of the formation torn loose by a diabase eruption. 

J 11. EASTERN NEVADA. 

From Hague's very full account 391c of the Carboniferous section at Eureka, Nev., 

the following extracts are taken: 

At Eureka the Carboniferous rocks have been estimated to measure 9,300 feet in thickness, 

which, however, does not represent the full development of the Carboniferous period, the upper 

Coal Measures, the top of the Paleozoic system, having suffered a very considerable amount 

of erosion. This upper limestone is by no means so thick as that found elsewhere. 
CARBONIFEROUS UNDIVIDED. 365 

The Carboniferous rocks have been subdivided into four epochs-first, Diamond Peak 

quartzite; second, Lower Coal-measure limestone; third, Weber conglomerate; fourth, Upper 

Coal-measure limestone. 

* * * * * * * * * At the base of the [Diamond Peak] horizon fine conglomerates firmly cemented together 

lie next the argillaceous shale of the White Pine epoch, a but quickly give place to a more massive, 

usually vitreous quartzite with a characteristic grayish-brown color and breaking irregularly 

with a flinty fracture. Intercalated black cherty bands, carrying a more or less ferruginous 

matter, occur near the middle portion of the horizon. Near the summit the beds pass into 

thinly laminated green, brown, and chocolate-colored schists and clay shales. The Carboniferous age of the epoch is determined by a narrow belt of blue limestone, which occurs interstratified in the quartzite about 200 feet above its base, in which the widespread species 

Productus semireticulatus occurs associated with an undetermined species of Athyris. As the 

fauna at the top of the black shales foreshadows the coming in of the Carboniferous, the presence 

of this characteristic Productus, with only a Carboniferous fauna higher up in the series, determines without question the geological position of the quartzite between the black shale and 

Coal-measure limestone. 

* * * * * * * * * 

In the Diamond Range the Lower Coal-measure limestone overlies conformably the Diamond 

Peak quartzite, the transition beds passing rapidly from siliceous to calcareous sediments. In 

their lithological character and physical habit they do not differ essentially from the same beds 

elsewhere, except, perhaps, at their base, where they carry intercalated beds of chert, argillite, 

and gritty, pebbly limestone, with evidences of shallow-water deposition. They pass rapidly, 

however, into purer gray and blue limestone, for the most part heavily bedded and distinctly 

stratified at varying intervals. In broad masses they resemble the Upper Nevada limestone 

but are rather lighter in color in distinction from the dark blue and black of the latter horizon. 

No true dolomite beds of any considerable thickness have been recognized, 9.21 per cent being 

the largest amount of magnesium carbonate obtained in any of the rocks subjected to chemical 

analysis. Across their broadest development they measure about 3,800 feeet in thickness, 

which is much less than has usually been assigned to this horizon in other mountain uplifts, 

more especially those lying eastward. 

As the term Lower Coal-measure has been employed by most geologists to designate this 

epoch throughout the Great Basin, it has been thought best to retain the name provisionally, 

although not exactly applicable, as the epoch includes such a commingling of species from both 

the Upper and Lower Coal measures that a separation of the beds seems quite impossible. 

* * * * * * * * * Three salient features in the life of the Lower Coal measures at Eureka call for special 

mention, and each is worthy of still further investigation-first, the occurrence near the base 

of the limestone of a fresh-water fauna; second, the varied development of the lamellibranchiates, a class which has heretofore been but sparingly represented in the collection of Carboniferous fossils from the Cordillera; third, the mingling near the base of the horizon of Devonian, 

Lower Carboniferous, and Coal measure species in gray limestone directly overlying beds 

characterized by a purely Coal measure fauna. 

* * * * * * * * * Conformably overlying the Lower Coal measures comes the ·weber conglomerate [probably 

of Pottsville agel, one of the most persistent and well-defined horizons over wide areas of the 

Cordillera, stretching westward all the way from the Front Range in Colorado to the Eureka 

Mountains. It varies in the nature of the sediment with every changing condition, but it is 

nearly everywhere easily recognized as a siliceous formation between two great masses of Carboniferous limestone. In places it is made up of an admixture of calcareous and sandy beds; 

in others of fine grits and shales; and again of nearly pure siliceous sediment, varying from 

fine to coarse grained, dependent largely upon the distance from any land area and depth of 

a Mississippian, according to G. H. Girty (comment on manuscript). 
366 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

water in which it was deposited. Here at Eureka the material is exceptionally coarse, with 

abundant evidence of shallow-water deposition and the existence of a land surface not very 

far removed at the time the beds were laid down. 

* * * * * * * * * Beds of the Upper Coal measures are found conformably overlying the Weber conglomerate. * * * The thickness attained by the rocks of this epoch is nowhere exposed in the 

district, the overlying beds having either suffered removal by the denudation or else been concealed beneath flows of igneous rocks. * * * The beds are estimated at 500 feet. In the 

northern and central portions of the State of Nevada the Upper Coal measure limestones attain 

a development of nearly 2,000 feet. * * * 

In the field the Upper Coal measures may be distinguished readily from the Lower Coal 

measures by their lighter color and the greater prevalence of fine-grained beds. These colors 

are light bluish gray and drab, the latter possessing a conchoidal fracture and compact texture. 

These compact limestones frequently present forms of erosion quite different from the coarsegrained and granular limestones of the Lower Coal measures. Throughout the horizon the 

limestones are interstratified with belts of grit and siliceous pebbles, held together by a calcareous cement, in which are intercalated thin beds of purer limestone. One or two prominent 

beds are apparently made up of quartz pebbles and fragments of an older limestone, carrying 

such fossils as Fusilina cylindrica and Productus semireticulatus, as if indicating that they had 

been derived from the underlying Carboniferous rocks. The fossils, however, which are all 

Coal measure species, might be derived quite as well from the Upper as from the Lower beds. 

A chemical examination failed to detect any beds of dolomite in the limestones, the highest 

amount of magnesium carbonate obtained being 1.33 per cent. This is not without interest, 

as it is the only limestone horizon in the Paleozoic series at Eureka free from dolomitic strata. 

J 12. SOUTHERN UTAH AND NORTHERN ARIZONA. 

The eastern margin of the Great Basin in southwestern Utah is mapped according to information supplied by F. B. Weeks.a The data for the eastern portion of 

the State, comprising the Green River and Grand River sections and the San Rafael 

Swell, are derived from McGee's map 567 and appear to represent observations by 

Powell and Dutton that are not otherwise recorded. 

The later Paleozoic section of northern Arizona comprises the Carboniferous 

formations known as the Redwall limestone (Mississippian and lower Pennsylvanian), the Aubrey group (upper Pennsylvanian), and the Moencopie formation 

(Permian~). The Redwall and Aubrey were first described by Gilbert/50 who. 

gives the following generalizations regarding the stratigraphy, beginning at the top 

with the "Aubrey" limestone (renamed Kaibab limestone by Darton 246a in 1910, 

Aubrey being retained for the group), which in some areas is overlain by Triassic 

strata and in other areas by the Moencopie formation 246b (Permian~): 

The Aubrey limestone has a thickness of 820 feet on Kanab Creek, and this is about its 

maximum. * * * Lithologically the limestone is characterized by a great abundance of 

chert, which, toward the top, sometimes constitutes half the mass. Near the middle it is, in 

some places, interrupted by a belt of shale, with gypsum. * * * 

The Aubrey sandstone series has a thickness, in the Aubrey Cliffs and along the Grand 

Canyon, of about 1,000 feet. In every exposure a portion of this body is massive and crossbedded and another portion soft and gypsiferous, but the order of these parts is not constant. 

In the Aubrey Cliff the compact rock is at the top and, together with the Aubrey limestone, 

holds a sheer bluff, at the foot of which the softer portion spreads a broad slope. Along the 

a Personal communication. 

• 
CARBONIFEROUS UNDIVIDED. 367 

Grand Canyon, at Kanab Creek, and near the Uinkaret Mountains the upper sandstone is soft 

anll produces a slope in the profile, while the lower is hard and unites its steep escarpment with 

that of the Redwalllimestone. The sandstones contain no fossils, but an intercalated limestone 

below the middle of the series at Canyon Creek bears the familiar Coal Measure shells. 

The Redwalllimestone has, upon fresh fracture, a gray color and shows its red rust only on 

weather-stained cliffs. In its general character it is heavy bedded to massive. At the top 

sandstone alternates with the limestone for from 200 to 500 feet. Through its lower half the 

firm limestone is interrupted by occasional shaly bands, which serve to break its escarpment 

into a series of narrow terraces, but above them stands a sheer perpendicular face, of from 800 

to 1,000 feet. The average total thickness is 2,500 feet. 

Accompanying these stratigraphic notes are lists of fossils, according to which 

the highest beds were referred to the "Permo-Carboniferous" and the upper half 

of the Redwall to the "Coal Measures" (Pennsylvanian), with a doubtful determination of "Lower Carboniferous" below the middle. Gilbert regarded it as possible 

that the Redwall extended down to include Devonian. 

A recent publication on the stratigraphic succession and age of the rocks of 

northern Arizona is that by Darton, 246 already cited. 

J 13. COLORADO. 

The Carboniferous terranes of Colorado have been described, compared, and 

correlated by Girty 362 in a monographic work, to ·which reference should be made 

for a general treatment of the whole subject. 

The following extracts present the general relations: 

The lower Carboniferous strata of Colorado are geologically comparatively unimportant 

by reason of their thinness, but they are widely distributed and form one of the richest metalliferous horizons in the entire rock series. This horizon is everywhere a limestone or a dolomite7 

sometimes more or less interstratified with shale, but owing to minor differences of lithologic 

character and circumstances of distribution several local names have been received by it. In 

central Colorado this limestone is called the Leadville limestone. In the San Juan region it is 

called the Ouray limestone, and along the Front Range it has received the name of the Millsap 

limestone. The lower portion almost everywhere contains a distinctive and unmistakable 

Devonian fauna. At least this fauna has been found at so many and such widely separated 

points that it may safely be regarded as generally present over the central part of the State 

wherever the formation is brought to view. In the few fragments of it which are still visible 

slong the Front Range, however, the Devonian fauna seems to be wanting. 

* * * * * * * * * 

Along the eastern margin of the Front Range the Mississippian limestone appears in several 

places. It is in this tract called the Millsap limestone. The Millsap limestone was first 

described in the Pikes Peak folio, from which I abstract the following: It consists only of local 

remnants resting upon the Fremont limestone in Garden Park and along the western line 

toward Canyon. It is represented by about 30 feet of thinly bedded variegated dolomitic 

limestone, with a few thin sandstone layers. Chert nodules in the upper limestone layers 

carry casts of Spirijer rockymontanus and Seminula subtilita. It is divided from both the 

formation which preceded and that which followed it by an erosional unconformity. 

* * * * * * * * * 

In the San Juan region Mississippian time is represented by the Ouray limestone, the major 

portion of the formation, however, containing a Devonian fauna. 

The Ouray limestone is defined by Cross and Spencer somewhat as follows: It consists of 

massive beds of limestone separated by thin intercalations of marl or shale. Certain thin 

bands are frequently quite coarsely crystalline, but the large mass of the formation is a dense 
368 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA, 

or semicrystalline limestone. The thickness is about 150 feet. The greater part of this forma~ 

tion appears to be of Devonian age, and it was only comparatively recently that a Mississippian 

fauna was obtained from its upper portion. The latter is intimately related to the Mississippian 

faunas at Leadville and Aspen, and also to the Waverly fauna of the Wasatch limestone of Utah, 

the Madison limestone of Wyoming and Montana, the typical Waverly of Ohio, and the 

Chouteau limestone of Missouri. The fauna of the Millsap limestone, as we know it from 

Perry Park and also from Garden Park and Canyon, and that of the Leadville limestone at 

Leadville present a rather peculiar facies. but even this fauna seems to be related to those of 

the early Mississippian, and it is somewhat singular that the Leadville fauna is more nearly 

allied to that of Perry and Garden parks, while lithologically and stratigraphically the Leadville 

as a formation is especially to be compared with the Leadville of Aspen and of the Crested 

Butte region. I think we can safely regard these faunas as varying facies of a single widespread 

and contemporaneous fauna, the differences being due in part to varying environmental conditions and in part to quite a different cause. Our collecti~ns from these beds are extremely 

meager, and to this circumstance can be referred some of the differences at present existing. 

* * * * * * * * * 

It is now fairly certain that the Carboniferous portion of the Leadville, Ouray, and Millsap 

limestones are of early Mississippian age. 

This formation, or, as it has received several names, this horizon, is widely distributed in 

Colorado. It is known in the Grand River region (the Devonian portion has been recognized 

on the White River and at Glenwood Springs and the Carboniferous probably on Eagle River), 

in the Elk Mountain region, in the South Park region, in the northern part of the Sangre de 

Cristo Range, in the San Juan region, and along the Front Range. It is probably lacking over 

much of the Front Range and Sangre de Cristo areas, in the Uinta Mountains, and in the valleys 

of the Dolores and the Grand, and it is concealed over extensive areas by deposits of later 

geologic age; but it is perhaps the most widespread of all the Paleozoic formations except those 

belonging to the Pennsylvanian. The remarkable persistency of this horizon as a limestone 

formation, not only in Colorado but throughout the West, and the widespread distribution of 

essentially the same fauna would argue extended and uniform marine conditions during Mississippian time. 

* * * * * * * * * 

The Lower Carboniferous period was followed by an epoch of elevation and erosion. At 

all events none but the early portion of Missisippian time is apparently represented in the 

Colorado sediments. The chronological point at which this elevation took place is, except in a 

general way, unknown. It may have occurred soon after the formation of the Leadville limestone, the absence of the upper Mississippian horizons being due not so much to erosion as to 

nondeposition; but it seems to me rather more probable that this episode was nearly contemporaneous with the elevation in eastern North America at the close of Mississippian time. That 

the elevation is of wide extent is indicated by the absence over such large areas in our Western 

States of upper Mississippian faunas. To the erosion which resulted from this elevation the 

variation in thickness of the Leadville limestone in different sections can often be ascribed. 

When subsidence again permitted the formation of sediments, the earliest deposits were 

frequently of a less purely marine character, and shortly a great thickness of sands and conglomerates intermingled with nonpersistent limestone bands began to form over great areas in 

the State. 

The Paleozoic section of central Colorado, by which term I would include the Grand River, 

Elk Mountain, and South Park areas, is singularly uniform, and this is scarcely less true of the 

strata of Carboniferous age than of the earlier Paleozoics. Though these are fairly constant in 

lithologic characters, the nomenclature employed for them has varied somewhat. Thus in the 

Anthracite-Crested Butte folio the Carboniferous formations are called the Leadville limestone, 

Weber limestone, and Maroon conglomerate; in the Aspen monograph the Leadville limestone, 

Weber formation, Maroon formation, and the Triassic; in the Tenmile folio the Leadville 

limestone, Weber shale, Weber grits, Maroon formation, and Wyoming formation; and in tho 

Leadville monograph the Blue limestone, Weber shale, Weber grits, and Upper Coal Measures. 
CARBONIFEROUS UNDIVIDED. 369 

From special reports the following details are cited: 

The Carboniferous of northwestern Colorado south of the fortieth parallel is 

described in the Anthracite-Crested Butte folio by Eldridge/04 who distinguished 

the following, in ascending order: Leadville limestone, \Veber formation, and Maroon 

conglomerate. 

In the Leadville district, central Colorado, Emmons 321 distinguished the following subdivisions of the Carboniferous: 

Carboniferous, 3, 700 to 4,200 feet: 

Upper Coal Measures: Blue and drab limestones and dolomites, with red sandstones and shales. 

Mud shales at top. 1,000 to 1,500 feet. 

Weber grits: Coarse white sandstones, passing into conglomerates, and siliceous and highly 

micaceous shales, with occasional beds of black argillite and blue dolomitic limestone. 

Weber shales: Calcareous and carbonaceous shales, with quartzite. 

Thickness of Weber grits and shales, 2,500 feet. 

Blue [Leadville] limestone: Compact, heavy-bedded dark-blue dolomitic limestone. Siliceous 

concretions at top, in form of black chert. 200 feet. 

The Leadville ("Blue") limestone is regarded by Girty as equivalent to the 

upper part of the Ouray limestone of southwestern Colorado. The "Weber shales" 

are treated by Emmons 321a as a subdivision (150 to 300 feet thick) of the "Weber 

grits." The siliceous beds of the "Upper Coal Measures" he states 321b are "not 

distinguishable from those of the Weber grits at the base, but pass upward into reddish sandstones, which in their turn are sometimes difficult to distinguish from the 

overlying red sandstones of the Trias." 

This sequence at Leadville is at the north end of the belt of Carboniferous rocks 

which extends thence southward west of the Colorado Front Range into New 

Mexico, to the vicinity of Santa Fe. Beyond that point after a brief interruption 

the strata continue in the upper Rio Grande valley. 

In Colorado east of the Front Range the Carboniferous presents a less complete 

s'3ction than that found west of the range at Leadville and thence southward. In 

the Pikes Peak quadrangle occur the Millsap limestone and the Fountain formation. The Fountain is not very definitely correlated with other Carboniferous 

formations. The Millsap is a thin-bedded dolomitic limestone, which rests unconformably upon the Fremont limestone (late Ordovician) and which, having been 

deeply eroded before the close of the Carboniferous, is but 30 feet thick in this 

locality. It is regarded as approximately equivalent to the Leadville limestone of 

north-central Colorado. The Fountain is made up of red sandstone and conglomerate and forms a part of the so-called "Red Beds," which were deposited unconformably upon Ordovician and pre-Cambrian and composed in part of detritus 

from the gneisses and granites. The local thickness is 1,000 feet. 

The age of the Fountain formation has been in doubt on account of the scarcity 

of fossils. It is now regarded by Girty as wholly Pennsylvanian and by Henderson 

as Mississippian below and Pennsylvanian above. Henderson 434 states: 

At the northern boundary of Colorado we found a chert concretion zone containing Spirij .. er 

cenrronatus Winchell, Orancena subelliptica var. hardingensis Girty, and Spiriferina solidirostris 

White, a fauna which is considered Mississippian and is found on the east side of the Front 

Range at Canyon City and elsewhere. Tho first-named species and others of like age were 

long ago reported from that region, but the record had little value because the position in the 

formation was not given. We traced the chert zone for 8 or 9 miles southward, finding it 

48011°--12----24 
370 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

everywhere within a few feet of the contact of the conglomerate with the granite and uniformly 

containing fossils, but found none farther south. The coarse sandstone and conglomerate 

series in which this fossiliferous zone occurs appears to be stratigraphically continuous with 

the Fountain formation in the Boulder district as defined by Dr. Fenneman,a who correlates 

it with the Fountain of the Colorado Springs region. We have traced the formation in the 

field the entire distance from the Wyoming line to Boulder and find no reason to doubt that the 

horizon containing the chert fossils is the equivalent of the base of the Fountain as representEd 

at Boulder, or possibly even much higher than the base as it occurs immediately north of Boulder, 

where the formation is much thicker than near the ·wyoming line. 

In limestones at a much higher horizon we found a Pennsylvanian fauna (tentatively considered older than Knight's so-called "Permian" of Wyoming), consisting of Productus cora 

D'Orb., P .. nebmscensis Owen, Spirifer rockymontana Marcou, Sq_uamularia perplexa McCh., 

Derbya n. sp. ~. Phillipsia aff. major Shumard, Myalina swallowi McC., abundant crinoid stems 

and others. These limestones were said by Darton b to pass into the Fountain conglomerates 

in traveling southward. Of this we are by no means certain without further investigation, 

but they seem certainly to belong at the very top of the Fountain or base of the overlying 

Lyons formation of Fenneman's bulletin. These limestones nearly disappear at the Cache la 

Poudre, and a little work just north of that stream is necessary to determine their exact position. We have traced the contact of the Fountain and Lyons all the way from the northern 

line of the State to Boulder except 2 or 3 miles between the Cache la Poudre and Owl Canyon, 

and believe the Tensleep sandstone of Darton's paper to be the stratigraphic equivalent of 

Fenneman's Lyons. 

It seems very clear that all of the Fountain sandstones and conglomerates of northern 

Colorado are Carboniferous, the base being probably Mississippian (certainly so in the northern 

portion of the field) and the upper portion possibly as late as Pennsylvanian. It also seems 

likely that the Lyons is Pennsylvanian. 

.. The fossils were, through the kindness or'Dr. T. W. Stanton, of the United States Geological 

Survey, submitted to Dr .. G. H. Girty, whose determinations are followed in this paper. 

Girtyc states that he believes the fossiliferous cherts which occur in the Fountain formation to be derived from Mississippian limestone, and he does not think 

they determine the age of the Fountain. David Whitec states that the fossil plants 

found in the Fountain formation are of Pottsville age. 

The San Juan Mountain district of southwestern Colorado has become through 

the studies of Cross, Spencer, Howe, and others, a standard of reference for the 

geologic section of that central region of the Rocky Mountains where the Carboniferous is characterized by several very distinct formations and unconformities. 

The base of the section, the Ouray limestone, has already been described (pp. 

367-368). The lower part contains a Devonian fauna, but. an upper fossiliferous 

horizon is of Mississippian age. Cross 194 states: 

The erosion in the interval following Mississippian sedimentation removed those strata 

completely over large areas. As neither the upper Devonian nor the basal Carboniferous horizon 

is everywhere fossiliferous, it is impossible to decide in many places whether the upper portion 

of the Ouray limestone ledge is Carboniferous or not. 

From the great quantity of Carboniferous chert nodules in the succeeding formation it 

must be assumed that above the known horizons of the Ouray there once existed in this region 

a considerable thickness of chert-bearing limestone of Mississippian age. It seems not unlikely 

a Fenneman, N. M., Geology of the Boulder district, Colorado: Bull. U. S. Geol. Survey No. 265, 1905. 

b Darton, N.H., Geology and underground water resources of the central Great Plains: Prof. Paper U.S. Geol. 

Survey No. 32, 1905. 

c Notes en the manuscript of this paper. 
CARBONIFEROUS UNDIVIDED. 371 

that somewhere on tho slopes of the San Juan Mountains notable remnants of those beds may 

be found. 

From a comprehensive study by G. H. Girty of all Carboniferous invertebrate fossils thus 

far collected in Colorado, and available to him, the following brief summary concerning the 

.Mississippian of the San Juan region may be made. Thirty-two determinable species have thus 

far been obtained from tho chert pebbles of the l\Iolas formation, which were derived from 

the eroded beds, and from two localities in the upper zone of the Ouray limestone. This fauna 

is closely similar to that of the Wasatch limestone of rtah and the Madison limestone of the 

Yellowstone National Park. It is also similar to the small faunas obtained in Colorado from 

the Leadville limestone in the Mosquito Range, at Aspen, Crested Butte, and ncar Salida, and 

that from the Millsap limestone of the Front Range near Canyon and in Garden and Perry 

parks. Dr. Girty concludes that the Leadville limestone, which was originally assigned to 

the Mississippian because of fossils found in· its upper part, and the ·Ouray limestone, which 

has been considered Devonian on account of the fauna in its lower and middle portions, are 

equivalent. He thinks that careful search would in many cases show both faunas where only 

one is now known. 

The Pennsylvanian of the San Juan district comprises, from the base up, the 

Molas, Hermosa, and Rico formations. These are succeeded by the Cutler (Permian?) formation. The sequence is summarized as follows from the Needle Mountains 

folio, 194a where full descriptions may be found: 

Sys- Setern. ries. 

----

~ 

<>· 

0 

cO 

'§ 

... 

Q) 

il; 

"' d ;:I 

0 

... "' ·s Jl "' ·s .!; 0 ~ 

1: en 

.:: "' .:: C,.) Q) 

il; 

--

.& . -~ § -~ ""''" ~ 

::s 

Generalized section for the Needle Mountains quadrangle. 

Formation. 

Cutler formation. 

I Rico formation. 

Thickness 

(feet). 

300± 

Character and distribution. 

Complex of bright-red sandstone, lighter-red or pinkish grits, and 

conglomerate, alternating with sandy shale and earthy or sandy 

limestone of varying shades of red. Limestone conglomerate 

fossiliferous . 

IOO+I Dark reddish-brown sandstone and pink grits, with intercalated -~ greenish or reddish shale and sandy fossiliferous limestone. 

---------]'-' __ ,_ - ------------------------------~ 

Hermosa formation. 2,000 

Series of limestone, grits, sandstones, and shales of variable distribution and development. Limestone in thick, massive beds 

predominates in the middle and upper parts of the section, 

the lower portion being mainly sandstone and shale, with a few 

limestone layers. Numerous invertebrate fossils occur in ~hales and limestones. 

--------------------------------------

Molas formation. 

unconformity 

Ouray limestone. 

Red calcareous shale and sandstone, containing pebbles of Missis75± sippian chert and limestone, and limestone lenses with Pennsylvanian fossils. 

Buff limestone, compact above, thin bedded below with shale and 

100--250 quartzitic partings. Mississippian fossils in upper third, 

Devonian in lower portion. 

In southwestern Colorado and southeastern Utah the Carboniferous formations 

distinguished in the San Juan district have recently been traced and correlated in 

part with other occurrences in Utah, Arizona, and New Mexico. Fossils collected 

by Newberry and Powell near the junction of Grand and Green rivers recently 

compared by Girty with other collections made by Cross and Spencer at Moab, 
372 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

on Grand River, though within a few miles of one another, appear to show different 

relations with western and eastern faunas. Cross 189d quotes Girty as follows: 

Considering the Powell and Newberry collections together it is notable that they contain 

a considerable number of species which may be called distinctive western types, as compared 

with the Pennsylvanian fauna of Colorado and of the Mississippi Valley. * * * In some 

cases nothing at all closely related to the types indicated is known from the region to the east. 

In other instances there are more or less similar species known which are not yet regarded as 

identical with western forms, although they may prove to be so. 

The collections from Moab consist entirely of typical Pennsylvanian species, lacking tho 

forms specified as characteristic of the far western areas. The distinctly Pennsylvanian forms 

found at the junction of the Green and Grand occur, however, at Moab. The Sinbad Valley 

fauna is very closely related to that from Moab. 

In view of the fact that none of these collections can be considered as exhaustive for the 

localities, numerical comparisons are more or less untrustworthy; yet the table brings out certain contrasts or resemblances which seem worthy of note. Out of 42 species represented in 

tho Powell and Newberry collections but 9 have been found at Moab, or in the Sinbad Valley, 

while out of 43 species obtained in these latter localities 29 are known from the Pennsylvanian 

rocks of southwestern or central Colorado. 

On the basis of the fossil evidence alone there can be no hesitation in considering the Moab 

and Sin bad Valley sections as belonging to the Hermosa formation rather than to the Aubrey, 

as represented in the lower Grand River valley. 

J-L 13. WYOMING, NORTHERN COLORADO, AND SOUTH DAKOTA. 

The stratigraphy of the Carboniferous sequence in the Bighorn Mountains and 

other ranges of Wyoming, and in the Black Hills has been summed up by Darton: 237g 

The Lower Carboniferous rocks are exposed principally in the Black Hills and Bighorn 

uplifts, and a few small areas occur along the foot of the Front Range, in Colorado. It is probable that these rocks extend widely under the Great Plains, but no borings have gone deep 

enough to reach them, except in eastern Kansas and southeastern Nebraska. 

In the Black Hills the Mississippian is represented by two limestone formations, the Englewood and the Pahasapa, both containing an abundance of characteristic fossils, those of the 

Englewood being equivalent to the lowest Mississippian (Chouteau or Kinderhook) and the 

Pahasapa equivalent to the Madison limestone of the northwest. Some Leperditia in the concretions in red shale at the base of the Minnelusa are of a type characteristic of the Mississippian, 

especially at about the horizon of the St. Louis limestone. It is possible that considerable of 

the lower part of the [overlying] Minnelusa is also of Mississippian age, for it appears to be equivalent to the Hartville limestone. The Littlehorn limestone of the Bighorn uplift consists mainly 

of a representative of the Madison and Pahasapa limestones, and doubtless the Englewood is 

also included, but the upper limit of rocks of Mississippian age in both uplifts has not yet been 

ascertained. 

Further ~etails concerning the Black Hills are given in another paper by 

Darton 232b as follows: 

[The Englewood limestone] appears to extend continuously around the Black Hills, everywhere immediately underlying the Pahasapa limestone. It averages 20 to 30 feet in thickness 

and presents frequent outcrops in the lower slopes of the limestone escarpment and in numerous 

canyons. It merges rapidly into the overlying [Pahasapa] limestone, occasionally with a few 

feet of impure buff limestone intervening. It is usually sharply separated from the [underlying] 

Deadwood formation, but only by a sudden change in the nature of the materials. The Englewood limestone is usually fossiliferous, containing numerous corals and occasional shells. The 
CARBONIFEROUS UNDIVIDED. 373 

following forms have been reported: Fenestella, Orthothetes [Schuchertella], Leptrena, Spirifer, 

Chonetes logani, Reticularia peculiaris, Syringothyris carteri, and crinoids. It is correlated with 

the Chouteau or Kinderhook of the Mississippi Valley. · 

The Pahasapa limestone (Mississippian), directly overlies the Englewood limestone (also Mississippian), into which it merges. It is a massive gray limestone 

without noteworthy subdivisions, varies in thickness from 225 to 500 feet, and 

according to Darton contains Spirijer rockymontanus, Seminula dawsoni (Athyris 

subtilita), Productus and Zaphrentis. 

Darton 237b describes the Minnelusa sandstone as follows: 

The Minnelusa formation consists mainly of thick beds of gray, buff, and reddish sandstones, usually fine grained, most of which, in their unweathered condition, contain a considerable proportion of carbonate of lime. Thin sheets of limestone occur in some districts and, 

less frequently, sandy shales of red or gray color. Some layers are cherty. * * * [The 

formation] is thickest on the western side [of the Black Hills], where it is fully 750 feet, and it 

thins gradually to the south and east, being about 400 feet thick in the southeastern portion of 

the uplift. 

On the evidence of "indistinct casts" of Productus semireticulatus and Seminuoa 

dawsonii (Athyris subtilita), "recognized with a fair degree of certainty," the upper 

part of the Minnelusa sandstone is assigned to the Pennsylvanian. The lower 

part, if correctly correlated with the lower part of the Hartville formation, 2371 is 

Mississippian. 

The Minnelusa sandstone is succeeded by the Opec he formation (Permian). (Se~ 

pp. 495-496.) 

The relations of the Carboniferous of the Black Hills to that of the Laramie and 

Hartville ranges of Wyoming are thus discussed by Darton: 237h 

Along the Laramie Range the apparent absence of Lower Carboniferous is an interesting 

feature, indicating either nondeposition or removal by the very profound later [middle] Carboniferous erosion. A short distance eastward, in the Hartville uplift, there are comprised 

in the Mississippian the Guernsey formation, 150 feet or more in thickness, and the lower members of the Hartville formation, the two formations being separated by strongly marked erosional unconformity. The basal sediments of the Hartville formation are red sands, and there 

is strong suggestion that these are of the same age as the red shale at the base of the Minnelusa. 

formation of the Black Hills and base of the Amsden formation in the Bighorns. The representative of the Lower Carboniferous in Colorado appears in the small areas at Perry Park, about. 

Manitou, about Canyon City, and southwest of Pueblo, and is known as the Millsap limestone. 

This limestone lies unconformably on the Cambrian, Ordovician, and pre-Cambrian and is 

unconformably overlain by the Fountain [Pottsville age] or lower Wyoming formation, which 

overlaps directly on the granites in most portions of the area. Its fauna is regarded as 

moderately early Mississippian. 

K 10. KLAMATH MOUNTAINS, CALIFORNIA. 

The Klamath Mountain section includes, according to Diller, 27ee, 279 several 

Carboniferous terranes-Bragdon formation, basal Mississippian of the region; 

Baird formation (Mississippian); McCloud limestone and Nosoni formation (includes 

the "McCloud shales"), Pennsylvanian; and limestones of the Hall City locality, 

which are Permian. 
374 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Of the section on McCloud River, in the northeastern belt of the Klamath 

Mountains, the original description by J. Perrin Smith 762 is given below: 

Columnar section of the metamorphic series of Shasta County. 

' . ol 00 +O;::l 

(!) 0 Shasta-Chico formation. '"(!) OC.J 

--------

coS '"CI ~ . Mormon sandstone of Big Bend. Thickness '" g s § ;::l Shales and shaly limestones of Big Canyon. ? .... ~_£·,o 

------- ---- --~· 

>:i Hosselkus lime- Spiriferina beds, 50 feet siliceous limestone. 

.;i Atractites beds, 100 feet siliceous limestone. 

u:i ~ stone. Trachyceras beds, 50 feet soft limestone . . ;3 s ... ,... 400 feet . E-< ..8 --

.... '" (!) 

p.. ., ol Swearinger Halobia slates, 100 feet calcareous slates. p.. (!) slates. Monotis shales, 100 feet argillites and tuffs. 

u:i p 0 .;3 

... 

E-< Siliceou.s and calcareous shales and conglomerates, --- at ro Silverthorn's ferry and on Squaw Creek, with Trachy- .;3 Pitt shales. ceras whitneyi, etc., about 1,500 feet below the Hossel- ... >:i 2,000 feet . E-< kus limestone. (!) -~ Several hundred feet of shales and conglomerates with- 8 ...., 

ol out fossils. :s s ...,... 

---- '" --""""'-'- ..8 

u:i ...., ;::l .... Siliceous and calcareous shales and conglomerates, with 2 ~ 

I ~ McCloud shales. Upper Carboniferous fauna at the base. Occurs on the 1,000 feet. ·s McCloud River. about 20 miles north of the United 

u:i 0 States fisheries.· ;::l ..0 

2 '" ol (!) 0 

~ ,_, ~ (!) McCloud lime- Massive limestones and marbles of the McCloud RiYer; 0 p.. s 2,000 feet. ..0 .... stone . rich in corals and brachiopods. ... p.. 0 • 

ol p «-<;::l 

0 '"00 

~ -- ~:0 0 <!lO;::i 0 Baird shales. Siliceous black shales of the United States fisheries at ;s:..o 0 500 feet. .s~a~ '-' Baird; v-ery fossiliferous in places . 0:::1 ;:;:: 

,!.. 

~ d ~.B d Kennett lime- Limestones and shales near Kennett, Sacramento Thickness ~.~ s.. ..S-S stones and on <ll;::l ~g~ shales. River, with Devonian corals. ? 

A wsS I 

The McCloud formation is especially well developed in the region of the McCloud River 

in Shasta County, and from this it receives its name. The formation consists entirely of 

Carboniferous strata, the Baird siliceous shales, overlain by the heavily bedded McCloud limestone, with some beds of igneous rock. The thickness IS estimated at about 2,500 feet, but 

this may be far from the true thickness. 

* * * * * * * * * 

The Baird shales consist of about 500 feet of black metamorphi~ siliceous shales, in places 

calcareous and occasionally sandy. At the top, too, are beds of diabase and other eruptives, 

which, however, do not seem to make up any considerable thickness of the rocks. The Baird 

shales extend from near the junction of the Pitt and the McCloud rivers northward for about 

20 miles along the McCloud, but they were studied by the writer only in the neighborhood of 

the United States fisheries at Baird. 

The strata have a general dip to the east, but this is very inconstant; their strike is approximately north and south. What underlies them could not be made out. They certainly are 

younger than the Kennett limestones, but what the interval between the two formations and 

whether they are conformable or not could not be ascertained. They are probably overlain 
CARBONIFEROUS UNDIVIDED. 375 

conformably by the McCloud limestone, but the contact could not be observed, and the diabase 

which separates the two divisions may mark an unconformity. 

* * * * * * * * * 

The list of fossils from the Baird contains a total of 84 species, of which 19 were not specifically identified. Out of the 65 forms specifically determined 26 occur in the Waverly of the 

Mississippi Valley, although 8 of these also occur in the Upper Carboniferous of that region. 

Fifteen are known to occur in the Devonian of the Eastern States, but of these 6 also occur 

in the Waverly; thus there are only 9 forms that in the Mississippi Valley, or east of it, 

would be considered as decidedly Devonian. Thirty-six are kmown from the Waverly and 

Lower Carboniferous of Utah, Nevada, and New Mexico; of these 29 correspond to forms 

described by Walcott from the Lower Carboniferous of the Eureka district, Nevada. Three 

species, Aviculopecten caboniferus, Aviculopecten interlineatus, and Macrodon tenuistriatus, have 

been considered characteristic of Upper Carboniferous. 

With this assemblage of species one would not hesitate to place these strata low down in 

the Carboniferous, but whether they are equivalent to the Waverly is a question not so easily 

settled. Although about one-half of the species are found in the Waverly and nearly onefourth in the Devonian of the Mississippi Valley, 29 of these and a large number of others as 

yet unknown in California, were found in the Eureka district, Nevada, in strata of Lower 

Carboniferous age but lying 3,000 feet above the Upper Devonian White Pine shale. 

We do not know the age of the rocks immediately underlying the Baird shales, but the 

siliceous shales of the Sacramento River lie some distance below them and are probably in part 

of Carboniferous age. · It thus becomes probable that in California, as in Nevada, the Waverly 

fauna, with a few Devonian forms, lived on after the corresponding faunas had become extinct 

in the eastern region. A migration of these survivors into the Lower Carboniferous sea of the 

Mississippi Valley may explain the supposed colony mentioned by C. R. Keyes from the Burlington of Missouri, and observed in Arkansas by the Geological Survey of Arkansas. In 

both places, in the midst of the undoubted Lower Carboniferous faunas, there appears a group 

of fossils that if found alone would be classed as of Waverly age. They are not colonies in the 

sense in which Barrande used that word but are simply migrations from one faunal region into 

another, due to shifting of physical barriers; these migrations have taken place during all time 

and have complicated correlations, until we lose faith not only in the idea of synchronism as 

proved by fossils, but also in homotaxis, unless we can find the direction of the migration. 

In the paleontological sense the Baird shales are homotaxial with the Waverly, while 

stratigraphically they probably are not but would agree more nearly in position with the higher 

divisions of the Lower Carboniferous of the Mississippi Valley. 

The occurrence of Productus giganteus Martin in these strata is very interesting. This is 

a common Lower Carboniferous fossil in Europe, but in America is not found east of this place, 

unless P. latissimus Sowerby, which F. B. Meek has cited from Montana, on the western slope 

of the Rocky Mountains, is an equivalent of it. This fact has been used by the writer as evidence 

that the European Carboniferous species found in America migrated through the ocean that 

connected on the west the American with the European Carboniferous waters. 

Immediately above the Baird shales, and probably conformably with them, lies the McCloud 

limestone. This series is about 2,000 feet in thickness, uniform in bedding, and very siliceous 

in places. Some few beds are altered to a crystalline marble, but in the mam the series is made 

up of a fine-grained hard gray limestone, which at the base contains few fossils besides corals, 

Glisiophyllum gabbi Meek, and Lithostrotion californiense :Meek. But toward the top the beds 

become more fossiliferous and contain a varied assemblage of species, which, however, do not 

rival in number those of the Baird shales. 

* * * * * * * * * 

Taken by itself the fauna [of the ":McCloud formation"] would not be characteristic of 

Upper Carboniferous, and indeed it is arbitrary to draw the line at the base of the limestone. 

Even Fusulina cylindrica, which in the region east of the Rocky Mountains seems to be characteristic of Upper Carboniferous, in Nevada is found also in Lower Carboniferous. But the 
376 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

most decisive proof of the Upper Carboniferous age of these strata is their position so far above 

the Baird shales, which have been shown in this paper to be equivalent to the Lower Carboniferous of the Eureka district, Nevada, which is known to occur 3,000 feet above the base of 

the formation. 

The McCloud limestone is probably equivalent to the limestone of the Caribou formation 

of Plumas County. But J. S. Diller thinks that they belong to a lower horizon than that 

assigned them by the writer. The Robinson beds of the Taylorville section are probably 

higher up in the section, but nevertheless the McCloud limestone is, in part at least, equivalent 

to the Coal Measures. 

Collections obtained by Diller were subsequently studied by Girty, who finds 

"little of material importance" to add to the lists made by J. Perrin Smith. "It 

may be remarked, however," says Girty, 276r "that recent collections made in the 

Carboniferous of Alaska are so suggestive of the fauna of the McCloud shale by 

way of containing the same or similar species as to indicate the extension of this 

fauna and, possibly, of the earlier Carboniferous faunas of the California province to 

that region." 

A later article by Diller 278 gives detailed descriptions of the Bragdon formation 

and cites paleontologic evidence of its early Carboniferous age, controverting 

Hershey's conclusion that it was Jurassic. 

The latest description, comprising a summary of all the facts relating to the 

Carboniferous of the Klamath Mountains, is given by Diller 279 in the Redding 

folio. 

K 11. NEVADA. 

(See J 11 (Eureka district), pp. 364-3661 and K 12 (Wasatch section), below.) 

K 12. WASATCH AND UINTA RANGES. 

The stratigraphic relations of the Carboniferous of the Weber Canyon section, 

Utah, are thus described by King: 505 

Directly and conformably overlying the Ogden quartzite comes the great Wahsatch limestone, which shows continuous outcrops for several miles and is thoroughly exposed from 

summit to base, making a total single series of limestone of 6,500 to 7,000 feet. The most 

valuable part of the whole ·weber section begins with the bottom of this limestone, which rests 

on a few thin sheets of olive-colored argillites separating it from the Ogden quartzite below. 

There seems to be no intercalation whatever of limy material at this point. The quartzite 

comes up sharply to the argillites, which are here not over 10 or 15 feet thick and give way 

immediately to impure earthy limestones of a very dark color. Thus far, on this section, the 

lower 1,200 feet of the Wahsatch have not yielded any fossils, but at the height of from 1,200 

to 1,400 feet from the bottom of the limestone, in the neighborhood of Weber station, the hills 

directly north of the depot are rich in Coal Measure forms. 

* * * * * * * * * 

At Weber station the beds, which are about 1,300 feet stratigraphically above the base of 

the limestone, * * * are usually of quite pure limestone, and the strata vary in width from 

extremely thin sheets to heavy tables. So, too, they vary in their lithological condition, some 

being highly crystalline, others merely granular, and some even very roughly granular. 

* * * * * * * * * 

Passing up the canyon, the series of limestones continues consecutively, without interruption, for 5 or 6 miles, exposing 5.000 to 6,000 feet in thickness above the depot. 

* * * * * * * * * 
CARBONIFEROUS UNDIVIDED. 377 

About 300 feet from the summit of the series are some extremely dark beds, which emit a 

fetid odor upon being struck with a hammer and are intercalated with very impure arenaceous 

limestones. * * * 

The limestones at 1,000 feet from the top inclose a series of thinly bedded but heavily 

blocked quartzites, which contain two or three sheets of small pebbles. These, however, are 

very thin and localized. The quartzite is more properly indurated sandstone and occupies a 

belt 150 feet thick. In general, the upper 1,000 or 1,500 feet. of this limestone series are made 

up of thinly bedded rocks, loss pure than the strata below and more or less intercalated with 

siliceous zones. Some of the beds are also considerably argillaceous. 

* * * * * * * * * 

The closing members of the Wahsatch group are arenaceous limestone with a brilliant 

brick color. 

The passage from the Wahsatch limestone into the Weber quartzite is made in perfect 

conformity and, as the beds clearly evidence, with undisturbed consecutive deposition. Above 

the reddened and arenaceous summit of the W ahsatch limestone are a few intercalations of 

siliceous limestone. * * * In this lower zone are sheets of conglomerate, the pebbles of 

which arc usually small and composed of white quartz. The general appearance of the quartzite 

zone is here that of a coarse, rather gritty sandstone, unevenly compressed into quartzite. The 

bottom of the series is prevailingly red for about 250 feet and averages coarser than the material above. Over the red is a very finely laminated white and grayish quartzite, quite uniform 

in texture and with only the most sparing inclosures of pebbles. * * * A mile and a half 

east from the base of the series there is scarcely any conglomerate at all, and the rock is true 

quartzite of whitish or greenish hue, developing on many of its weathered surfaces a peculiar 

dark brown stain which looks like the oxidation of manganese. * * * Conformably overlying the quartzite is a very heavy bed of much altered gray limestone from 600 to 700 feet 

thick. The bedding planes are often entirely obliterated and the material extremely crystalline, showing traces of great interior disturbance. The lower beds show a true conformity with 

the underlying quartzite. * * * The average colors of these limestones are cream-grays, 

inclining often to white in the more crystalline portions. * * * Overlying this main body 

of 700 feet of limestone is a series of yellow shaly limestones 17 5 feet thick. * * * Overlying these calcareous shales, as heretofore quite conformable, is a series of sand and mud rocks, 

all more or less calcareous, varying in color from chocolate to olive, with red argillaceous sandstones, the whole about 225 feet thick. It has the appearance of a comparatively shallow 

water deposit, made of argillaceous material, limestone, and sand, the thickness of the individual beds being unusually limited. There are very many beds not over an inch thick. On 

the upper surface of the strata, at several horizons, ripple marks are preserved with unusual 

distinctness and on a scale of fineness not often seen, the distance between the wave and the 

trough being frequently not over an inch or an inch and a half. Alternating dark chocolate 

and olive-colored shales form the lower 200 feet of this group, while the upper 25 or 30 feet are 

pretty solid sandstone. Over these, still conformable, are 100 feet of yellow and olive calcareous shales, which are so earthy as usually to decompose, yielding a bad outcrop. Above this 

is a bed of bluish-gray limestone, rather compact, about 150 feet in thickness. Next comes 20 

feet of reddish-brown clayey sand, hardly compacted into rock, containing thin stony seams 

intercalated at intervals in the soft, easily eroded matter. This is immediately followed by 75 

foot of a yellowish-gray, brittle, easily decomposed limestone. Next above are 100 feet of 

light-colored, very thinly bedded limestones, that give way to lOO,feet more of dark, siliceous, 

tough limestone, which breaks under the hammer with great difficulty, yielding an exceedingly 

rough, ragged fracture. 

This section comprises both Mississippian and Pennsylvanian rocks. Weeks,873a 

describing the Uinta sections, says: 

Wherever fossils have been found in the lower and upper members of theW asatch limestone, 

they show the former to be of .Mississippian age and the latter of Pennsylvanian age. This is 

also true of the Uinta Range. The precise line of division has not yet been determined. In 
378 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

the Uinta Range about 600 feet of the 1,070 feet of beds that have been correlated wiGh the 

Wasatch limestone are certainly of Mississippian age. Powell correlated the beds of the Wasatch 

limestone with his Grand Canyon section. They correspond in general to the Redwall group 

The basal beds of this series are buff. blue, and gray limestones weathering darker in color, 

and some of them have a decided greenish tinge. They are usually in massive, brecciated beds 

having a thickness of 150 to 200 feet. Besides the brecciation or fracturing, many small faults 

occur in them. The succeeding beds, 6 inches to 1 foot thick, are buff-colored crystalline limestones having a total thickness of 300 feet, followed by 2.5 feet of thinner-bedded dark-blue and 

purple limestones containing a large amount of dark-colored chert. The fossils found in the 

above-described beds indicate that they are of Mississippian age. 

* * * * * * * * * 

The Pennsylvanian series comprises the upper part of the Wasatch limestone and the 

Weber formation. No name is given to the limestones of this series occurring beneath the 

Weber formation, leaving it for future detailed work to determine the beds which are to be 

assigned to this formation. In the Wasatch Mountains a similar succession of strata is exposed. 

In Powell's Grand Canyon section, Lower Aubrey group, and the Yampa sandstone of the Upper 

Aubrey group correspond to the Pennsylvanian series. The limestones below the Weber formation are to be correlated with the Lower Aubrey limestone and the Weber formation with the 

Aubrey sandstone of Walcott's section. So far as the faunas are known, they corroborate 

these correlations. 

The strata forming this subdivision are 300 to 500 feet of light-blue and gray limestones 

containing a considerable amount of light-colored chert, interstratified with fine-grained lightgray sandstones which toward the top contain bands of sandstone weathering brown and resembling in a marked degree the weathered material of the "Uinta" sandstone. These are succeeded 

by the quartzites of the Weber formation. 

The lower part of the Weber formation is a white and gray to greenish quartzite in thin 

and thick beds, some of which weather brown. In the upper part of the formation are alternating blue and white siliceous limestones and quartzites. The transition to the next series 

is through blue and reddish limestones and shales. The greatest thickness occurs on the south 

side of the Weber River, on the north slope of the range. To the east, on this side of the range, 

the formation is largely covered by Tertiary sediments or glacial debris. On the opposite (south) 

side of the range the formation is well exposed in all the principal canyons from the Provo River 

to Green River. This formation, like the "Uinta," is quartzitic in the western and central parts 

of the range and grades into a rather soft sandstone in the eastern part. No fossils were found 

in the Weber formation. 

The Permo-Carboniferous series of the Uinta Range seems to correspond in position, thickness, and general lithologic characters to the Upper Coal Measure and Permo-Carboniferous 

formations of the Fortieth Parallel Survey. On similar grounds they may be correlated with 

the Aubrey limestone [Pennsylvanian] of Walcott's Grand Canyon section. The correlation 

with Powell's section is less definite. The limestones overlying the Yampa sandstone of the 

Upper Aubrey group and an undetermined thickness of the shales and soft sandstones of the 

Shinarump group appear to correspond to the beds under discussion. 

The upper beds of the Weber formation are calcareous sandstones and siliceous limestones 

which weather yellow and grade into thin red shales and red and blue limestones of the upper 

part of the Permo-Carboniferous series. This series is well exposed on the Duchesne River, 

Rock Creek, Whiterocks Creek, on the south side of the range, and in the Horseshoe Canyon of 

Green River, on the north side of the range. 

One of the best sections occurs on the east side of the Duchesne River below the mouth of 

West Fork. There the lower 600 feet of the Permo-Carboniferous are formed of red and purple 

shales and blue limestones. Above is 1,000 feet of light-gray and white sandstones, with some 

interbedded limestones in the lower part. In the upper part these sandstones occur in alternating layers of soft and compact beds full of peculiar black points or specks. These are 

succeeded by 800 to 900 feet of red shales, with a prominent band of light-colored shale at the top. 
CARBONIFEROUS UNDIVIDED. 379 

Girty states that the "Permo-Carboniferous" of the foregoing section is equivalent to Walcott's Permian, not to the Aubrey group of the Grand Canyon section. 

Blackwelder a states that the Weber Canyon section as described by King is 

subject to corrections brought out by more recent study. Near the base of the 

section there are faults which complicate the succession. The quartzite, supposed 

to be the Ogden quartzite of King (Devonian), is in reality the Middle Cambrian 

(Brigham quartzite) and the olive-colored argillites are Middle Cambrian shale. 

The nonfossiliferous lower portion of the Carboniferous limestone may well include 

beds of Devonian age such as have been found on the borders of Cache Valley farther 

north. The fossils in the "Wasatch limestone" are typical members of the widespread Madison fauna, which is of early Mississippian age. Upon the weathered 

and slightly irregular surface of the limestone rests the Morgan formation of Weeks,S43 

consisting of brick-red shale and sandstone with a few beds of gray limestone and 

light-colored sandstones which become bright red on exposure. This passes up conformably into the lower, more or less calcareous portion of the Weber quartzite. 

The quartzite itself has not been remeasured accurately, but the thickness reported 

by King is believed to be somewhat excessive. The alternating series of dark limestone and shale with local sandstone beds, which rests upon the Weber quartzite, 

corresponds to Boutwell's Park City formation. It contains the workable phosphate 

deposits of the region. There is considerable although not conclusive evidence of 

an important unconformity between the Weber and Park City formations. A section measured in undisturbed strata near the headwaters of Ogden River is given 

below for comparison with the Weber Canyon section: 

Partial columnar section of Carboniferous beds in the northeastern part of Weber County, Utah. 

Pennsylvanian: Feet. 

Park City formation (upper portion concealed or removed by erosion): 

Dark shale with beds of limestone and rock phosphate............................ 438 

Gray limestone with chert nodules and beds of shale............................. 301 

Creamy-white sandstone with beds of cherty limestone............................ 220 

Unconformity? 

Mississippian (perhaps including early Pennsylvanian at the top): 

"Wasatch limestone:" 

Gray crystalline limestone and purplish shale containing nodules of bright-green limestone (abundant fossils-Productus, Spirifer, etc.-tentatively referred by G. H. 

Girty to the Kaskaskia formation of the Mississippi Valley)....................... 140+ 

Dark-gray limestone and dolomite with beds of calcareous sandstone. Fossils rare or 

poorly preserved............................................................. 795 

Black phosphatic shale and cherty limestone.................................... 126 

Limestone, black to gray, with chert nodules only near the top. Abundant fossils, 

especially in the lower layers, the species being typical of the Madison fauna.... 1,015 

Gray shale and limestone with poorly preserved marine fossils like those just above. 180 

Shale, dolomitic limestone, and sandstone; ripple marks and sun cracks and bright 

ferruginous bands suggest nonmarine origin. No fossils......................... 220 

Obscure unconformity. 

Hard siliceous limestone and dolomite, largely concealed. No fossils found in these 

rocks, but the lower layers may be equivalent to the Devonian limestone of the 

Bear River Mountains ......................................................... 1,100+ 

4,535+ 

a Personal communication. 
380 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The section of Pennsylvanian and Permian beds exposed in Big Cottonwood 

Canyon, southeast of Salt Lake City, is described in detail by Boutwe11, 93 who gives 

the following section: 

-Dolumnar section of portion of Carbon~ferous ~n Big Cottonwood Canyon, Wasatch Range, Utah. 

--------

Series. Formation. Thickness Character. (feet). 

-

Red shales, locally sandy, with interbedded coarse gray sandAnkareh shale. 1,500+ stones. Carries in lower portion Aviculipecten weberensis, 

A. curticardinalis, A. parvulus, Jfyalina permiana. No eco- nomic importance. 

I Tlmyn~ lim~J"ne. Calcareous with sandstones and shales; "Midred " shale sepal'i rates more calcareous upper from more.arenaceous lower 

.~ portion. Carries large fauna, with many new fossil species, 

s 1,190 chiefly pelecypods, including Pentacrinus sp., Jfyalina per- ... miana, Jf. aviculoides, Aviculipecten curticardinalis, A. weber- <ll 

p., ensis, A. parvulus, A. occidaneus, Lingulas, Spirifers, Dentalia. Forms country rock for replacement ore bodies and 

lodes. 

Red shale, thinly bedded, fine grained. Bears ripple marks, 

Woodside shale. 1,180 mud cracks, and raindrop imprints. No direct economic 

importance. 

I Calcareous with interbedded quartzite, sandstones and some 

d 

shale. Carries Lingulidiscina sp., Productus cora, Productus 

Park City limestone. 590 sp., Plagioglypta canua, Euphemus subpapillosus, Bellero- ol phon sp. Forms country rock for principal bonanza ·s 

ol replacement ore bodies. 

~ 00 

~ 

~ Gray quartzite, massively bedded, homogeneous, dense. <ll 

p., Carries, in Weber Canyon, Lingula sp., Productus subhor- Weber quartzite. 

I 

1,350+ ridus, Schizodus sp., Plagioglypta canna, Euphemus subpapillosus. Forms wall or walls of lead-silver lodes. 

I 

L 11. BLUE MOUNTAINS, OREGON. 

Lindgren 540 refers certain clay slates, siliceous argillites, and limestones of the 

Blue Mountains in Oregon doubtfully to the Carboniferous: 

RocK:s referred to the Paleozoic system occupy a large area in the lower Burnt River region, 

about Pleasant Valley, in the southern Elkhorn Range, and on the headwaters of Burnt River 

and Granite Creek. Smaller isolated areas of clay slate, inclosed in diorites, diabases, and 

serpcntines, also occur near Susanville, in the Quartzburg district, and near Canyon. There is 

no clue to the age of these, but they arc believed to belong to the * * * Paleozoic series. The 

prevailing rocks through the whole of this large sedimentary area are dark and very fine grained, 

ranging from cherts to siliceous argillites and ordinary clay slates. A large proportion of the 

sediments show no distinct stratification in ordinary outcrops, but in thin sections the carbonaceous streaks which indicate the planes of deposition are readily recognized. In many places, 

however, the rocks are normal clay slates of fairly fissile character. 

* * * * * * * * * 

The only place where fossils were found is near the Bonanza mine, at VTinterville, where 

round crinoid stems occur in a small mass of crystalline limestone. The other limestone lenses 

in the series, though carefully examined, yielded no fossils. Round crinoid stems are most 

common in Paleozoic rocks; taken in consideration with the fact that the series as a whole has 

a distinctly older appearance than the Triassic of Eagle Creek, from which it is also petrographically very different, we may with some confidence refer it to the Paleozoic and possibly 
CARBONIFEROUS UNDIVIDED. 381 

to the Carboniferous. The series is similar to the Delhi division of the Calaveras forma-tion in 

the Sierra Nevada, a which is believed to belong to the Carboniferous. 

Well-defined Carboniferous fossils have been found by Prof. Condon in the Crooked River 

drainage, in the extreme western part of the Blue :Mountains. 

L 12. WESTERN MONTANA. 

The general succession of Carboniferous rocks in the Philipsburg quadrangle, 

Montana, as stated by F. C. Calkins, in an unpublished manuscript, is as follows: 

Pennsylvanian, Quadrant formation: Feet. 

Quartzitic member.............................................................. 400 

Shaly member...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 600-50 

Slight unconformity (?) 

Mississippian, Madison limestone: 

Thick-bedded limestone ......................................................... 1,000-300 

Shaly black limestone........................................................... 300 

Madison limestone.-The Madison limestone in all the Montana sections has basal shaly 

beds overlain by more massive beds. Although in the Little Belt mines Weed has recognized 

three lithologic subdivisions, only two are recognizable in the Philipsburg quadrangle. The 

lower consists mainly of fiaggy limestones, black on fresh fracture but weathering to a delicate 

blue-gray or drab tint. In most places two thin beds of coal-black calcareous shale are intercalated with these limestones, one lying near the base and the other a little below the middle of 

the lower member. The upper member contains abundant chert. Its lower part is mostly dark 

blue-gray and in beds of moderate thickness. The upper part is of more massive limestones, 

mostly white to pale gray and nonmagnesian, their smoothly weathered surfaces and translucence being in contrast to the dull and gritty character of the Jefferson limestone. 

Dr. Girty characterizes the abundant fossils collected from the Madison limestone in the 

Philipsburg quadrangle as referable to the lower Mississippian fauna, which is so widely 

. distributed over the West. He has identified the following forms: 

Syringopora surcularia. 

Syringopora sp. 

Aulopora geometrica. 

Menophyllum ulrichanum. 

Amplexus sp. 

Echinocrinus sp. 

Fenestella 2 sp. 

Schuchertella inflata. 

Rhipidomella pulchella. 

Rhi pidomella michelini? 

Chonetes illinoisensis. 

Productus hevicosta. 

Camarotmchia metallica. 

Spirifer centronatus. 

Composita immatura. 

Composita sp. 

Eumetria marcyi. 

Apparent unconformity between Pennsylvanian and Mississippian.-The difference of age 

between the faunas from the Madison and Quadrant indicates the lapse of a considerable time 

interval between them. Physical evidence of unconformity is given by the sharp lithologic 

distinction between the uppermost beds of Madison limestone and the .lowest part of the Quadrant formation. A further indication of an erosion interval between them is the dwindling of 

the upper Madison west of Foster Creek in the Flint Creek Range, to about half its normal 

thickness. Angular unconformity has not been proved. 

Quadrant formation.-The two members of the Quadrant are lithologically in strong contrast. The lower, generally not well exposed except where indurated by contact metamorphism, 

consists of maroon shales containing gray concretions and thin-bedded gray, white, and pink 

magnesian limestones. The thickest limestone layer observed is about 8 feet thick. The bestexposed section is on the east fork of Rock Creek in the Anaconda Range. Here 125 feet of 

shale and limestone immediately beneath the quartzite are continuously exposed, and the 

imperfect exposure below indicates a total thickness of about 500 feet. This is near the 

maximum, however, and at the place above mentioned where the Madison was observed in 

a Colfax folio (No. 66), Geol. Atlas U.S., U.S. Geol. Survey., 1900. 
382 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

much less than normal thickness, the Quadrant is only about 50 feet thick. The usual thickness 

is nearer the maximum than the minimum. 

Fossils have been collected from the lower member of the Quadrant formation at two localities in the Philipsburg quadrangle. Two miles south of Georgetown Lake the red shales below 

the quartzite have yielded the following forms, identified by Dr. Girty: 

Arch:oeocidaris sp. 

Fenestella sp. 

Rhombopora sp. 

Derbya crassa. 

Productus cora. 

Spirifer rockymontanus. 

Euomphalus catilloides. 

Dr. Girty considers this faunule referable to the Pennsylvanian. 

The upper member of the Quadrant, in the Rock Creek section, is a single massive stratum 

of pure hard quartzite about 300 feet thick. Almost everywhere else in the quadrangle it comprises (1) a basal stratum of pure vitreous quartzite; (2.) a medial stratum, generally not well 

exposed, of calcareous shale, shaly and cherty limestone, and a peculiar cherty quartzite with 

irregular limestone concretions; (3) an upper quartzite, less pure than the lower. The aggregate thickness of these is about 400 feet on the little hill just west of the Philipsburg high school. 

Fossils collected at this place from the medial calcareous bed (2), were reported by Mr. 

Weed in 1900.a Girty referred these to the following forms: 

Camarotrechia sappho. 

C. near C. congregata. 

Glyptodesma rectum? 

A viculopecten sp. 

Cyathophyllum sp. 

These fossils, in Girty's opinion, had a Devonian aspect. 

In 1906 D. F. MacDonald gathered at the same place a small collection, even less satisfactory than Weed's. This was submitted to E. M. Kindle, who, although unaware of Girty's 

report, likewise hesitatingly referred the horizon to the Devonian. 

In the light of later evidence Girty has further discussed this fauna as follows: b 

"The fauna of lot 1 is with little question the same which Mr. Weed obtained from nearly 

the same locality and which I reported on in 1900. 

"Although when I first encountered this fauna !referred it to the Devonian, I now believe 

that it is probably Pennsylvanian. The two most significant types are the Camarotcechias and 

the Glyptodesma rectum? Large Rhynchonellas are rare in the typical Pennsylvanian, and 

none are known having the structure of Camarotcechia, as is the case with these. An exception 

must be made of Rhynchopora, but that genus has also a punctate shell. It was largely on this 

account, since Camarotcechia appeared to be restricted to the Devonian and Mississippian, that 

I was previously led to determine the horizon as Devonian. The force of this evidence holds 

good to-day, more or less. On the other hand, the Glyptodesma rectum?, represented only by 

one external mold, is probably a Myalina related to M. deltoidea Gab b. In view of the facts that 

there has recently come to hand a large species of Camarotcechia (distinct, however, from the 

Philipsburg forms) from Utah high in the Pennsylvanian and that the stratigraphic position of 

lot 1 is above that of lot 12, it now seems probable that the age of the former is, as already 

stated, really Pennsylvanian. In this event the fauna is unusual and interesting." 

H. S. Gale c in 1910 examined beds belonging to the Quadrant formation in the area south 

of the Philipsburg quadrangle. He considers the lower and purer quartzite of the quartzite 

member of the Quadrant equivalent to the Weber quartzite of southern Idaho and Utah, and 

the portion of the formation above this quartzite as equivalent to the Park City formation of the 

same regions. This correlation is based on lithologic similarity and the presence of phosphate~ 

which was found at the top of the cherty limestone between the two siliceoud strata. 

a Weed, W. H., Geology of the Little Belt Mountains, Montana: Twentieth Ann. Rept. U.S. Geol. Survey, pt. 3, 

1899, p. 188. 

b Personal communication. See also Kindle, E. M., Fauna and Rtratigraphy of the Jefferson limestone in the 

northern Rocky Mountain region: Am. Paleontology, Bull. Cornell Univ. No. 20, 1908, p. 19, footnote. 

coral communication to F. C. Calkins. 
CARBONIFEROUS UNDIVIDED. 383 

L 19-20. NEW BRUNSWICK. 

The Carboniferous of New Brunswick comprises Mississippian, Pennsylvanian, 

and Permian strata. They have been studied in detail and have been the subject of several reports and discussions. Bailey 45a has recently summed up the 

general facts in an article from which the following extract is taken. 

In the reports and maps of the Geological Survey it has been usual to regard this system 

in New Brunswick as embracing three principal members, somewhat strongly contrasted in 

lithological characters and conditions of origin, viz, the Lower Carboniferous, the Carboniferous 

proper or Coal Measures, and the newer or Permo-Carboniferous, the first consisting of reddish 

sediments, with evidences of a generally marine origin; the second mostly gray or purplish, 

rarely red beds of marsh or fresh-water origin; and the third again showing a predominance of 

red tints, though without the marine limestones, gypsums, and salines which distinguish the 

Lower Carboniferous formation. In the "Acadian geology" of Sir William Dawson (1868) the 

Carboniferous proper was further subdivided into the "Millstone grit series" and the "Middle 

coal formation;" while with the marine limestones of the Lower Carboniferous division were 

associated, under the name of Lower Coal Measures (in addition to some beds resembling tho 

Middle Coal Measures) the bituminous deposits known as the Albert shales. 

It has already been stated as regards the peculiar shales last mentioned that there is at 

present a growing tendency to Tegard them as of Devonian rather than Carboniferous age, 

being the equivalents of the fish-bearing and fern-bearing rocks of the Baie des Chaleurs, though 

very unlike them in their physical aspects. It has also been stated that there are serious objections to this view; but as the question is mainly one of the interpretation of fossils and has little 

or no bearing upon the main subject of this report, that of the true coal-bearing rocks, it need 

not be further considered here. The doubtful beds in question being thus eliminated, the rocks 

which lie above them are very easily and clearly divisible into two great groups, viz, the Lower 

Carboniferous formation and the Carboniferous proper, or Coal Measures, while another, viz, 

the Upper or Permo-Carboniferous is less certainly distinguishable. The characters of these 

several subdivisions may be briefly summarized as follows: 

Lower Carboniferous.-The lowest beds of this formation, as here limited, are usually coarse 

conglomerates, their composition and hence their general appearance varying with the nature 

of the rocks upon which they rest. They are, however, in almost every instance of a reddish 

color, varying from a clear rich red to a dark brownish red.· They are usually also much harder 

than similar beds higher in the series, and in places are much stained with oxide of manganese. 

The cement is always to some extent and often very markedly calcareous. At some points, a~ . 

at Quaco Head, St. John County, similar conglomerates are underlain by beds of limestone, 

but the principal limestone strata are situated at the summit rather than at the base of the 

formation. The conglomerates are usually followed by or interstratified with sandstones, also 

usually of a reddish color and markedly calcareous. Higher still the beds become finer, embracing shaly and marly deposits, upon which in many instances rest beds of gray fiaggy, sometimes 

bituminous limestone and heavy beds of gypsum. Between these higher beds and the basal rocks ' 

of the coal formation (Millstone grit) it js common to find extensive sheets of igneous rocks, sometimes in the form of compact diabase, sometimes as a vesicular or amygdaloidal ash rock, and 

sometimes as claystone or rhyolite; but such plutonic masses are not confined to the summit of 

the formation, being sometimes, as at Quaco, near its base. Where igneous rocks are associated, 

as at Quaco and Hampstead, Queens County, with limestones, the latter have been more or 

less completely converted into marble. 

The thickness of the Lower Carboniferous system varies greatly, but, according to measurements made by Dr. R. W. Ells in Albert and Westmorland, it reaches in those counties about 

5,000 feet. Its thickness in the central basin is probably much less. [For "Coal Measures," 

see Chapter X, p. 473; for "Permo-Carboniferous" see Chapter XI, p. 498.) 
384 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

L 20. NOVA SCOTIA AND ADJACENT PARTS OF NEW BRUNSWICK. 

·writing of the eastern counties of New Brunswick, Ells and Bailey 317 m 1876 

distinguished-

!. Metamorphic rocks of pre-Carboniferous age, with intrusive syenite. 

2. Lower Carboniferous formation, including the Albert shales. 

3. :Millstone grit formation, or lower member of the Carboniferous system. 

The Lower Carboniferous rocks * * * lie along the northern flank and at the eastern 

end of a chain of highlands * * * [and] consist largely of slates, usually either chloritic 

or talcose in character and of various colors; but with which are associated at some points 

thick beds of grit and conglomerate, also chloritic or talcose, and, less commonly, beds of pink 

or flesh-red felsite or petrosilex. Their age has not yet been definitely determined, but from 

observations made upon the more westerly portions of the same belt in St. John and King's 

counties, they would appear to belong to what, in previous reports, has been described as the 

Coastal group, which is believed to be of pre-Silurian and possibly Huronian age. 

Along the northern border of the metamorphic belt, and immediately adjacent to the 

Lower Carboniferous tract * * * chloritic slates are associated with large quantities of reddish and gray syenite, which, in addition to occupying considerable areas, may be seen penetrating the slates in numerous veins and irregular masses of greater or less extent. They are 

* * * the source from which the materials of the Lower Carboniferous conglomerates have 

been to a great extent derived. 

The Lower Carboniferous rocks * * * form the eastward extension of a considerable 

area. * * * The red sediments of which it is composed are at several points covered unconformably by isolated areas of gray rocks, having usually a much less inclination and belonging 

to the :Millstone grit series, or the basal portion of the coal measures. * * * Being unconformable alike to the older slates upon which. they rest, and to the newer gray rocks which 

succeed them upon the north, these sediments present in their distribution great irregularity, 

filling on the one hand depressions and indentations in the underlying formation, while on the 

other they are themselves often wholly or partially concealed by the deposits of the Millstone 

grit. * * * 

The rocks being greatly disturbed, Ells and Bailey give the following sectionas probably representing the true succession, while the thicknesses given are in each case the 

least assignable to the different groups, allowance being made for their apparent increase by 

faulting. The order is an ascending one. 

1. Basal conglomerate, sometimes wanting; when present usually of a dull greenish color, less 

coarse than the conglomerates which succeed, and made up mostly of slaty fragments. 

Thickness unknown. 

2. Calcarea-bituminous shales, from gray to dark brown in color, and including the so-called 

"Albert shales." At the base these beds are unconformably overlain by brownish-red 

Feet. 

sandy shale. __________________________ - _-- ____ -------- _----------------------------.- 850 

3. Gray bituminous and micaceous oil-bearing sandstones and coarse conglomerates, in massive 

beds of very various composition, usually of a reddish tint; less rubbly and more calcareous 

than those of division L ______________ ... - -- _ - _ -- -- -- - - _ -- -.. _ . _ - -- -- - --......... ----- 700 

4. Red and gray calcareous, sandy, and argillaceous beds, in frequent alternations, with thin 

beds of conglomerate and toward the top heavy beds of fine, rubbly brownish-red shales._ 450 

5. Red and gray conglomerate, gray fiaggy limestone, and gypsum.-- .... -.-------- ...... -.- 1,950 

In his report for 1884 (published in 1886) Ells"" repeats the above section without modification and describes many local sections in New Brunswick and Nova 

Scotia. 

Fletcher 333 reported on the geology o£ the northern counties of Nova Scotia 

(Richmond, Inverness, Guysborough, and Antigonish) in 1879-80, giving many 
CARBONIFEROUS UNDIVIDED. 385 

minutely measured sections, which together with those of other systems are in the 

report for 1886 generalized and accompanied by details of local sections and distribution.334 The latest general account of the Carboniferous of Pictou and Colchester counties, which appears to hold in its broader features for the region as a 

whole, is contained in Fletcher's report for 1887-1891/35 from which the following 

notes are taken: 

Permian: 

Upper red sandstone and shale group, with thin bands of limestone. 

Middle gray sandstone and shale group, with small coal seams. 

New Glasgow conglomerate. 

Carboniferous: 

Coal measures. 

Millstone grit. 

Carboniferous limestone. 

Carboniferous conglomerate. 

Devonian: 

Upper red slate and sandstone group. Red rocks of Union, on the Truro & Pictou Railway.[a] 

Middle gray slate and sandstone group. Riversdale [a] and McKay Head rocks.[b] 

The lowest Carboniferous is described as a coarse basal conglomerate, which 

contains pebbles of the underlying rocks from 1 inch to several inches in diameter 

and which is interstratified with gray and red sandstone. The identification of 

this formation in distinction to the middle Carboniferous "Millstone grit" is not 

always certain. The deposit is not everywhere present, the Carboniferous limestone overlapping upon older rocks in many places. 

The Carboniferous limestone is a formation "characterized by the occurrence 

of gypsum, limestone, sandstones, marls, and other soft and friable rocks, apparently everywhere unconformable upon all underlying formations." 335d 

With reference to these two formations of the "Lower Carboniferous" and the 

"Millstone grit" Ami 18b says in describing the section of the Knoydart (Devonian) 

of McArras Brook, Antigonish County: 

To the north and west of this Devonian area are seen newer measures referable to three 

distinct horizons of the Carboniferous system as developed in this portion of Nova Scotia. 

These include-

(a) The so-called "Carboniferous conglomerate" formation described in the above report.c 

This series is presumably equivalent to the Bonaventure formation of Gaspe, and is doubtfully 

referred to it here. · 

(b) The "Carboniferous limestone" series with its marls, sandstones, and marine limestones 

and gypsum, designated (in part at least) by the writer as the Hopewell formation. 

(c) The so-called "Millstone grit" series, for the most part very fiat-lying and undisturbed, 

showing that the physical disturbances and agencies to which the Silurian and Devonian strata 

have been subjected which have dislocated and tilted their strata had disappeared previous to 

the time when these Carboniferous grits were laid down. The so-called "Millstone grit" series, 

which is very doubtfully the equivalent of the true "Millstone grit" of England, was designated 

by the writer as the Westville formation, in order to separate it from the other formations in 

the district. 

In 1899 Ami 21 presented a discussion of facts and opinions relating to the 

classification of the Carboniferous of eastern Canada and included as "Eo-Carbona Middle Carboniferous (Pottsville).-B. W. 

b True "Coal :Measures" (Allegheny?), Stellarton formation of Pictou, etc.··-B. W. 

c Ann. Rept. Geol. Survey Canada for 1886, pp. 71P, 85P, and 124P; idem for 1890-91, p. 173P. 

48011°-12----25 
386 INDEX 'TO THE STRATIGRAPHY OF NORTH AMERICA. 

iferous" the two formations known as the Union and Riversdale, which had been 

classed as Devonian on stratigraphic grounds. He sums up his conclusion m a 

table as follows: 

Formations of the Carboniferous of a portion of Nova Scotia. 

Formations. Northern areas. Southern areas. 

!

Cape John ............ !Cape John sandstones ......................................... . Pictou ...... __ . ______ . Pictou freestones .. _ . __ .. ______ . _________ . ___ .... ____ . _______ _ N eo-Carboniferous Smelt Brook ... _._._. . Srnel t Brook shales_ .. __ ... _________________ ..... ____ . ___ . ___ _ Small's Brook. ___ ._._ Spirorbis limestones .. __ .. _ .. ____ . _. _ .. _ .......... ____ . _______ _ 

New Glasgow .... __ ... New Glasgow conglomerates ...................... _____ . _______ _ Coal Measures ... ____ . __ . ____ _ 

Unconformity. 

Order. 

XII. 

XI. 

X. 

IX. 

VIII. 

VII. 

!

Stellarton •......... } !Millstone grit ................... )Millstone grit .... _ ...... _..... VI. 

Meso-Carboniferous Westville........... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Unconformity(?)._._. ___ .. __ . V. 

H?pewell. · · ·· ·----- ---------- · · ·· · ·· · ·· ·· · · · ·· · · ·- Hopewell and Windsor ...... -{ IV. W1ndsor. ___ . _ .... _ _ . __ . __ . __ ........ _ .· ........ _. _ _ III. 

Unconformity ____ ............. _ .................. _ ..... _ ... _ _ II. 

Eo-Carboniferous{U ~ion.· -· · · · · · · · --· - -· · · - -· -- - -- -- - --· -· · · · · · · · · · · · · - - U ~ion· --· - -- - -- -- --· -- -- ---} I R1versdale ..... _. _____ . __ . ______ . _____ . _______ . ____ .. _ _ R1versdale ........ __ ...... _ _ · 

In placing the Union and Riversdale at the base of the Carboniferous Ami 

accepted Fletcher's determination of their stratigraphic position below the lower 

Carboniferous limestone. Subsequent field study led him to recognize the fact 

that the limestone is overthrust upon these formations and normally belongs below 

them. He then accepted the evidence of the fossils, which places them in the 

"Meso-Carboniferous." 22 (See pp. 330-331.) 

L-M 11-12. WESTERN MONTANA AND NORTHERN WYOMING. 

Near the intersection of the forty-ninth parallel with the one hundred and 

fifteenth meridian, just west of the Flathead Valley, Montana, Carboniferous limestone of St. Louis age was identified by Weller. 940b It rests conformably upon a 

pure quartzite, 25 feet thick, which lies unconformably, though without marked 

angular discordance, upon pre-Cambrian argillite of the Belt series. The extension of this formation in the McDonald Range of southern Alberta has been noted 

by Leach 526 under the general term "Devono-Carboniferous." 

On the headwaters of Teton River, a branch of the Missouri, in latitude 48°, 

Carboniferous limestone forms the eastern portion of the Rocky Mountains between 

the Great Plains (Cretaceous) and the central ranges (Belt series, Algonkian), 

In the Belt Mountains and other ranges of southwestern Montana and northern 

Wyoming the Carboniferous is represented, according to Weed and others, by Madison limestone and Quadrant quartzite. The type locality from which they were 

described by Peale is in the Gallatin Valley near Three Forks, Mont. Peale 6318 

summarized the section. Girty 393d has since discussed the fauna and correlation 

of the Madison limestone under the heading "Lower Carboniferous," as follows: 

The Madison limestone J:!.as been divided by the geologists of the Survey, upon lithologic · 

characters, into nine beds, ranging from 24 to 32, both inclusive, of their section scheme. The 

following table, representing in condensed form the stratigraphic succession ascertained in the 
CARBONIFEROUS UNDIVIDED. 387 

Yellowstone National Park, was kindly supplied by .Mr. Arnold Hague, geologist in charge of 

the Yellowstone National Park survey: 

Quadrant quartzite. 

Madison limestone. 

32 . .Four strata of light-gray, more or less cherty limestone ............................ : .... . 

31. Gray banded limestone, with abundant fossils .......................................... . 

30. Massive light-gray limestone ......................................................... . 

29. Light-gray and brown, very finely crystalline or granular limestone ..................... . 

28. Limestone, crystalline, light gray, and generally massive .............................. . 

27. Limestone, dark gray and buff, very argillaceous, thick and thin bedded ................ . 

26. 15 feet of quite pure and 60 feet of thin-bedded argillaceous limestone, both containing 

fossils ............................................................................. . 

25. Coarsely crystalline dark-gray limestone ............................................... . 

24. Limestone, finely crystalline and massive below, cherty in its upper portion ............. . 

Three .Forks limestone. 

Feet. 

655 

400 

65 

85 

200 

50 

75 

80 

60 

1,670 

All the evidence available seems to indicate that the Madison limestone is faunally a unit 

and can not be subdivided on the basis of its contained fossils. 

Having given a table showing the rangEl' of species in the Madison limestone 

and having discussed certain diagnostic species, Girty 393e concludes: 

(1) The fauna of the .Madison limestone can be referred wholly and without question to 

Carboniferous time; (2) it has a marked Kinderhook facies;. (3) it is essentially the same 

fauna as that described by White, by Hall and Whitfield, and by Meek, and by them referred 

to the Kinderhook or Waverly; (4) the fauna is not separable into independent units but must 

be regarded as a whole. 

These views regarding the position of the Madison were reaffirmed by Girty 3633 

in 1905: 

The fauna of the Madison limestone, which has so wide a distribution in the West, is 

* * * closely related to the typical :Mississippian faunas. In my earlier work I correlated 

the Madison limestone with the Kinderhook, Burlington, and Keokuk groups of the Mississippi 

Valley and have seen no reason since to change my views. Nevertheless, it seems to be almost 

unquestionable that in some areas these western faunas, in their later developments, take on 

the aspect characteristic of the St. Louis epoch. Now here in the West, however, have any 

Kaskaskia faunas been discovered. One of three hypotheses seems necessary to explain this 

fact, which is no less striking, even should local areas of Kaskaskia roeks subseqw:mtly be discovered. Either no strata equivalent to the Kaskaskia have ever been deposited in this region; 

or, though deposited, they have since been removed; or else contemporaneously formed sediments supported a fauna which was so unlike the Kaskaskia that its equivalence has failed of 

recognition. Of these three hypotheses it is probable that the second is the correct one. Unmistakable evidence of unconformity between the Madison limestone (and its correlates) and the 

overlying beds has been found in so many points in the West that a period of erosion previous 

to the Pennsylvanian sediments can be hypothetized for all this western country, a generalization which is all the more safe from the widespread evidence of a similar occurrence in the 

central and eastern United States, and indeed in other parts of the world. 

Girty a states that we now have reason to believe that the Quadrant, from which 

no fossils were known when the foregoing was written and which was generally 

supposed to be equivalent to the Weber quartzite (Pennsylvanian), may be in part 

of upper Mississippian or Kaskaskian age in some areas. 

a Comment on manuscript. 
388 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

M 11. FRONT RANGE, ROCKY MOUNTAINS OF ALBERTA. 

The Banff series, consisting of upper shale, upper limestone, lower shale, and 

lower limestone, in the order named, constitutes the Carboniferous and possibly 

Upper Devonian of the eastern range of the Rockies in Alberta. McConnell 559b 

describes the strata as follows: 

The Cretaceous is underlain by the Banff limestone, of Lower Carboniferous or Upper 

Devonian age, and, notwithstanding the complete absence of all the intervening formations, 

no unconformity was anywhere detected between them, except where faulting is known to 

have occurred. The apparent conformity is perfect, even in the clearest sections, and the 

difficulty in drawing an exact line between the two series is further increased by the close lithological resemblance "hich the upper part of the Banff limestone bears to the lower beds of the 

Cretaceous. 

The Banff limestone series has a total thickness of about 5,100 feet and is divisible into a 

lower and upper limestone and into lower and upper shales. 

The upper shales vary in thickness from 500 to 1,500 feet but are usually in the neighborhood of 700 feet, and where this is much exceeded, as at the mouth of Johnson Creek, there is 

reason to suspect that some of the Cretaceous beds are included with them. They exhibit great 

diversity in structure and pass, according to the amount of arenaceous matter present, from 

finely fissile shales through flaggy and ordinary sandstone into hard quartzite. The quartzites, 

where pressnt, occupy the lower part of the division and are overlain by the shales, and the 

two sets of beds in this position can occasionally be traced from one end of the range to the other. 

In other cases, however, this regularity is wanting and shales constantly pass into quartzites 

and vice versa. These shales are often calcareous or dolomitic and in places are represented 

by an impure limestone, and they always contain sufficient iron to give them a reddish color 

when weathered. They are found on the western slopes of most of the ranges in the eastern 

part of the chain and also in the bottoms of most of the longitudinal valleys of the same district, 

as from their relative softness they are one of the valley-making formations of this part of the 

range, an office which they fill in common with the Cretaceous shales. The Upper Banff shales 

are underlain by about 3,000 feet of limestone, which may be called the Upper Banff limestone 

in order to distinguish it from the lower limestones of the same series. This usually occurs as a 

grayish, purely calcareous and well-crystallized rock but is also found under a number of other 

forms. It is often dolomitic, and hard, bluish, compact beds are not uncommon, nor are shales 

and sandstones altogether absent. Its most characteristic features, howev·er, are the abundance 

of crinoidal remains which it everywhere shows (some of the beds being wholly composed of 

the broken stems of crinoids) and the cherty concretions which are distributed through it, either 

irregularly or arranged in lines along the bedding. These concretions are especially abundant 

in Pilot Mountain and along the western side of the Sawback Range and in both these places 

are often united into thin irregular beds. They also become more numerous toward the top of 

the limestone and are occasionally continued on into the shales. 

Below these limestones come from 500 to 700 feet of shales and shaly limestone, constituting 

the Lower Banff shales. The shales are dark colored but usually weather red and are somewhat 

arenaceous and pass into flaggy sandstone. They are also nearly always calcareous, and in 

places the series is represented altogether by impure shaly limestones. At a point about 2 miles 

up a small creek, which joins the Bow River gap, this group is underlain by from 15 to 20 feet 

of coal-black fissile shales, which rest directly on the massive limestone beds of the underlying 

formation and are interesting on account of their fossiliferous character. A number of specimens 

of a Clymenia, besides other fossils, were collected here. At one point these black shales bend 

around a large and well-rounded limestone bowlder, belonging ap"parently to the Castle Mountain 

group, and looking exactly like an erratic of the glacial drift. 

The lowest division of the Banff limestone consists of from 600 to 800 feet of heavily bedded 

bluish and fairly compact limestone. In composition it is mostly calcareous, but it also contains 

a certain amount of dolomitic matter distributed in an irregular manner through the beds and 
CARBONIFEROUS UNDffiDED. 389 

evidently collected together by concretionary action. The dolomite is not visible on a fresh 

fracture, but, owing to its superior durability, it projects from weathered surfaces, over which 

it often forms a rough reticulation. This limestone differs from the Upper Banff limestone in 

being darker, more compact, and in the smaller number of crinoidal fragments and cherty concretions which it contains, although neither of these are altogether absent. * * * 

The fossils of the Banff limestone show both Devonian and Carboniferous forms, and include 

a Rhynchonella like roclcymontana, another like R. metallica, Atrypa reticular-is, and a Spirifer 

likeS. 1J)hitneyi>· also a species of Athyris, Productus, Lichas, Eridophyllum, and Diphyphyllum. 

A large number of other species have been obtained, but these have not yet been studied. 

The upper shales of this series have yielded some Aviculipectens and Lingulas. 

M 21. NEWFOUNDLAND. 

The Carboniferous of Newfoundland occurs in the general basin which contains 

the lower Carboniferous (Mississippian) and upper Carboniferous (Pennsylvanian) 

of Nova Scotia and New Brunswick. The former is probably represented by 

divisions a, b, and c of the classification quoted below, and the Pennsylvanian by 

divisions d and e. They can not be separated on the geologic map with the 

information at hand. 

Murray oosb in his report for 1873 gave the following account: 

By a glance at the geological map of Canada it will immediately be observed that a vast 

area of the provinces of New Brunswick and Nova Scotia is spread over by members of this 

series; and further that the geographical position, where similar measures have been recognized 

in Newfoundland, is suggestive of the latter being the prolongation of a great elliptical-shaped 

trough extending from the former, the center of which is concealed beneath the waters of the 

Gulf of St. Lawrence. It may also be perceived that while in New Brunswick the formation 

extends in a uniform unbroken sheet over the surface, it becomes broken and patched in Nova 

Scotia and Cape Breton. The symmetry of the ellipse, moreover, will be seen to be broken 

near its center at the Magdalen Islands, where a part of the lower members of the system come 

to the surface, indicating the axis of an anticlinal fold bearing in the direction of St. George's 

Bay. Proceeding from the westward, this fold would thus appear to be the first of a series of 

disturbances, which increase in frequency farther east and which are intensely developed in 

Newfoundland. The contymporaneity of the Carboniferous rocks of the latter with those of 

the mainland is manifested by the same want of conformity with the older and supporting 

formations and the almost exact resemblance which obtains in mineral, lithological, and fossil 

characters throughout the stratigraphical sequence, from the base upward; but the accumulation in the island would appear to be in considerably less volume than on the mainland, and so 

far as our researches will permit the expression of opinion, it seems that it is in the upper members 

that the Newfoundland series is principally wanting. The southeastern boundary of the formation may be traced from a little way north of Cape Ray along the northwest flank of the Long 

Range of Laurentian mountains, up to the extreme head of St. George's Bay, where, although 

concealed from view, it was supposed to cross over, and making a further stretch beneath the 

marshes to the northward, finally sweeps round in a westerly course and crosses Harry's Brook 

below Spruce Brook, where it rests upon strata of Lower Silurian age. Its course westward is 

then interrupted by the protrusion of the labradorites of the Indian Head Range; but westward 

from that range the whole of the flat country is supported by Carboniferous rocks, which rest 

upon the upturned edges of Lower Silurian strata, displayed in the mountains which bound the 

plain, and on the coast of Port-a-Port Bay. Irregular patches of the formation are then found 

farther west in Port-a-Port Bay, and a strip is displayed along the outer coast of the Long Point 

Peninsula of the same, while to the northward it is recognized in the valley of the Coal River. 

For convenience in describing the distribution of the series, I have divided it into five 

members, distinguished by letters, from a to e, inclusive, the general vertical section of which 

is given below, in descending order. Corresponding letters will be found on the map. 
390 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

(1•) Green and red sandstones, with brown and black carbonaceous shale, and brown and drabcolored clays. Fossil trees and flora abundant. Coal seams with underclays holding 

Feet. 

Stigmaria. [Pennsylvanian, "Coall\leasures."-David White] ........................ 1,000 

(d) Brown and reddish sandstones and conglomerates; brown, blackish, and greenish micaceous and arenaceous shale. False bedding in sandstones and ripple-marked surfaces 

frequent. Fossil plants, among which Sigillaria and Calamites are frequently met with. 

Thin seams and nests of coal. [Pottsville?-David \Yhite] ... __ . ______ . ______________ . 2,000 

(c) Variegated red, green, and drab-colored marls; red, green, and brown sandstones, which are 

frequently calcareous; beds of bluish and gray limestones, some beds apparently magnesian, and many contain a profusion of organic remains, marine shells, etc., carbonized 

plants in the arenaceous strata. Salt springs frequent. [Mauch Chunk?-David White]. 2,000 

(b) Great masses of gypsum, with green and brown argillaceous shale; red marly shale; bands 

of black or dark-gray limestone, and occasionally jet-black shale. [Pocono?-David 

\Vhite] .... ------ . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 

(a) Very coarse conglomerate composed of great bowlders and pebbles of Laurentian and Silurian rocks, cemented in a matrix of greenish-colored sand; great lenticular intercalations 

of sandstone with coarse arenaceous shale; large fragments of magnetic iron ore; pas~es 

at the top into a brownish-gray flaggy sandstone with brown and greenish shales which 

under lie the gypsum .. -- -- ____ . __ -- ... -- __ . -- .... -- ... __ .. __ .. __ . __ ... ______ . __ . . . .. 1, 300 

6,450 

M-P 8-11. ROCKY MOUNTAINS OF BRITISH COLUMBIA. 

The Cache Creek group of British Columbia is an ill-defined sequence which 

comprises Carboniferous limestone and various other sedimentary and volcanic 

rocks. It has' been identified more or less surely from the forty-ninth parallel to 

Alaska in the belt of metamorphic Paleozoic rocks. A comprehensive description 

is given by Dawson 261' 262 in his account of the Kamloops area, in British Columbia, 

from which the following is condensed: 

The Cache Creek formation, as shown on the present map and as now understood, must 

therefore be regarded as including a very thick series of Paleozoic rocks, of which the greater 

part is definitely referable to the Carboniferous period by means of its fossils but of which it is 

scarcely probable that the upper and lower limits agree precisely with those of the typical 

Carboniferous. It may very possibly be found at the base, particularly, to transgress these 

limits and to include beds older than those of the system. 

In attempting a brief general description of this formation, it must in the first place be 

observed that the extremely broken and disturbed character of the rocks almost everywhere 

renders it next to impossible to learn much about their attitude or sequence in any one locality. 

It is very generally impossible to determine whether the dip of the beds is normal or has been 

overturned. It is thus only by following the general association of the rocks from place to 

place and by piecing together facts observed at many different places that it becomes practicable 

to outline the salient features of the whole. 

The western part of the Kamloops sheet, between the Thompson and Bonaparte rivers on 

one side and the Fraser on the other, is the typical area for the Cache Creek formation, and the 

most definite feature which can be traced throughout is the belt of massive * * * and 

whitish limestones, sometimes marbles. * * * 

Practically the entire mass of the Marble Mountain Range is composed of these limestones, 

as well as the whole eastern part of the Pavilion Mountains. They include comparatively 

insignificant intercalretions of argillite, cherty quartzite, and materials of volcanic origin. 

Farther south, in the region to the east of Hat Creek, such materials become more abundant 

and form thick beds among the limestones, particularly the cherty quartzites and the greenstones. In this region it is probable that the lower part of the great limestone series is most 

prominently displayed and that the higher beds are more characteristic in the north, particularly in the Marble and Pavilion mountains. The earlier stages of the great period of limestone 

deposition appear to have been marked by frequent interruptions, during which argillaceous 
CARBONIFEROUS UNDIVIDED. 391 

and volcanic products were laid down; while in its later stages the deposition of the limestone 

must have been almost unbroken. The interlocking of the different classes of materials is such, 

however, as to show the close connection which obtains between the Marble Canyon limestones 

and the lower parts of the Cache Creek formation. * * * 

The extremely unsatisfactory condition of the rocks of the Cache Creek series for all purposes of measurement [is such that] in endeavoring to give some idea of the total volume of the 

formation, no even approximately correct data can be quoted. The subjoined summarized 

section is therefore merely an attempt to indicate the general order of succession, and to some 

extent the importance of the formation, in the western part of the area of the [Kamloops] map. 

The order is descending. 

l. Massive limestones (Marble Canyon limestone), with some minor intercalations of volcanic 

rocks, argillites, and cherty quartzites. At least 1,000 feet seen in some single exposures. 

Feet. 

Total thickness probably at least...................................................... 3,000 

2. Volcanic materials and limestones, with some argillites, cherty quartzites, etc. Minimum 

thickness about ...................................................................... 2,000 

3. Cherty quartzites, argillites, volcanic materials, and serpentineB, with some limestone. The 

thickness of these beds, or of a part of them, was roughly estimated in two places as between 

4,000 and 5,000 feet. Minimum total thickness say.................................. . 4,500 

* * * * * * * * 

9,500 

* 

Thus, the entire volume of the rocks of the Cache Creek formation as this is now defined, 

may be assumed to be about 10,000 feet as a minimum, while I am inclined to believe that it 

really exceeds 15,000 feet. 

* * * * * * * * * 

A few characteristic fossils have been obtained in a number of places beyond the limits of the 

present ~ap. At Stuart Lake (latitude 54° 30'), Dease River (latitude 59° 15'), Frances River 

(latitude 60° 30'), and on Tagish Lake (latitude 60°), fusuline limestones have been observed. 

To the westward of the Coast Ranges (in which it is probable that numerous infolds of 

Paleozoic rocks will yet be found) a formation known from its fossils to be of Carboniferous age 

is again well represented. This has, so far, not been very minutely examined or reported in 

detail, but it is known to comprise thick beds of limestones, argillites, and volcanic materials, 

the latter being even more characteristic and in greater development than in the region here 

specially dealt with. 

In the Rocky Mountains proper, or eastern member of the Cordilleran system, the section 

which must now be regarded as the typical one for these latitudes is that worked out by Mr. 

R. G. :McConnell. In this section the Carboniferous period is represented by the Banff lime 

series, which, including two shaly zones, has a thickness of 5,100 feet. This has yielded a number 

of fossils and these show that the series as a whole represents the lower part of the Carboniferous, 

passing below into the Devono-Carboniferous. The later part of the Carboniferous period seems 

either to be unrepresented, or, if represented at all, to find but a partial equivalent in the upper 

shales. It is thus very probable that before the close of the Carboniferous the present position 

of the Rocky Mountains formed part of a land area. 

* * * * * * * * * 

It has already been noted that the lower portions of the Cache Creek formation may be 

older than the Carboniferous period. The very general blending of the Carboniferous and 

Devonian systems in the West shows that no well-marked line need be anticipated at the base 

of the Carboniferous. The separation of any beds of Devonian age can only be made in the 

event of the future discovery of characteristic fossils. The same may be said respecting the 

possible existence of Silurian or Cambro-Silurian beds. 

Reference is made to the occurrence of limestone of the Cache Creek group 

on Atlin Lake, British Columbia, where it is present on both sides of Taku Arm, 389a 

in latitude 59° 30'; and 10° farther south dolomites, argillites, serpentine, and 
392 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

greenstone, probably belonging to the Cache Creek group, have been noted.99 In 

studying the Boundary Creek district, in British Columbia, adjoining the State of 

Washington, Brock 100 again distinguished the Cache Creek group among the 

metamorphic rocks of the region. He says: 

On Observation Mountain near Grand Forks and on the rounded hill a little south of west 

of this and some of the hillsides on Newby's ranch are crystalline mica and hornblende schist 

with a few bands of crystalline limestone. These highly altered rocks resemble lithologically 

those of the Shuswap series (Archean) but may only be the argillites and limestones found 

elsewhere, in a more metamorphosed form. 

The argillites, in places altered to schists and hornfels, limestone, usually crystalline, 

often highly so, quartzite, the latter occurring only sparingly, together with serpentine, which 

occurs in many portions of the districts associated with these, form a group which closely 

resembles the Cache Creek series described by Dr. Dawson and assigned by him to the Carboniferous. In the Boundary Creek sedimentary rocks no fossils have been found, but they are 

probably of about the same age as similar rocks occurring to the north and west and may, 

on this ground, be provisionally classed as Carboniferous. 

N-0 8-9. SOUTHEASTERN ALASKA. 

At Freshwater Bay, in the northeastern part of Chichagof Island, in latitude 

58°, occur limestones about 1,500 feet thick, which carry a lower Carboniferous fauna 

that is related to the Mississippian of the interior of the continent but is of a 

different facies. Kindle 496b correlates the formation with the lower Carboniferous 

of the upper Yukon and of the Cape Lisburne section. 

An upper Carboniferous fauna characterizes a limestone 600 feet thick which 

occurs about Pybus Bay, Admiralty Island, in latitude 58°. Kindle gives the 

following section: 

The oldest Carboniferous fauna which has been found in southeastern Alaska was obtained 

at Freshwater Bay, in the northeastern part of Chichagof Island. This fauna was submitted 

to Dr. George H. Girty, who states, in a report furnished the writer, that, "while not unlike 

the American Lower Carboniferous or Mississippian, it resembles and probably should be correlated with the Russian Lower Carboniferous or Productus giganteus zone or Mountain limestone." Freshwater Bay is the only locality visited where the Lower C~rboniferous fauna 

has been found in southeastern Alaska. This locality is important also because the stratigraphic 

relation of the Lower Carboniferous to the older rocks may be observed. 

On the northeastern side of the bay, and opposite the Silurian and Devonian limestones 

already described, the Carboniferous limestones form a low, narrow peninsula. * * * The 

thickness of the several divisions of the limestones which are exposed along the north shore 

of this peninsula is indicated approximately in the following section, which begins about one-half 

mile above (northwest of) North Passage Point: _ Feet. 

(e) Breccia of large gray limestone fragments. __ . ______ . ____ ................................. 100 

(d) Hard gray limestone, much fractured by numerous irregular joints and breaking into small 

irregular fragments on weathering. Large productoids common. Dip 30° to goo toward 

southwest; strike N. 40° W ..................... _ .......... _ ............ _ ..... _........ go 

(c) Gray limestone with frequent bands of black chert. Fossils scarce. Strike N. 10° ts 20° W.; 

dip 80° to goo NE ......... _ ........................... _ ................. ___ .......... 275 

(b) Dark-gray limestone with black chert bands. Fossils abundant near upper and lower limits. 

Average strike N. 30° E.; dip 70° to 80° NW .............. __ .... _ ...... __ .. ___ .......... 250 

(a) Limestone similar to b. Corals common ............ _ ... _._ ................ _ .... _ ...... _ .. 275 

ggo 
CARBONIFEROUS UNDIVIDED. 393 

Exposures on the north side of the bay and just west of the peninsula, which are lower 

but not continuous with this section, would add, if included in it, several hundred feet to its 

thickness. The total thickness of the Lower Carboniferous section is probably not less than 

1,500 feet. 

* * * * * * * * * 

The Lower Carboniferous in southeast Alaska, while representing a different facies from 

that of the Mississippi Valley, is still much more closely allied to the interior continental faunas 

than is the Upper Carboniferous fauna of this region. The Lower Carboniferous fauna is 

widely distributed in Alaska. It has been recognized as far north as Cape Lisburne, on the 

Arctic coast, and it occurs at numerous points on the Yukon and Porcupine rivers in eastern 

Alaska. 

Concerning the interval between the Upper and Lower Carboniferous faunas in this region 

we have but few data. No fauna representing it has been found. 

The younger of the two Carboniferous faunas of southeastern Alaska is well represented in 

the limestones about Pybus Bay, on the southeast side of Admiralty Island, where they outcrop 

extensively along both arms of the bay. The limestones characterized by this Upper Carboniferous fauna have a thickness of about 600 feet at Pybus Bay. These Upper Carboniferous 

limestones are generally heavy-bedded or massive. * * * The Lower Carboniferous 

limestones where observed have thinner bedding and are darker colored than those of the 

higher horizon. 

The following section, taken along the west shore of the east arm of the bay, indicates 

the character of the Carboniferous limestone (c of the section) and the associated beds: 

[Mesozoic:] Feet. 

(g) Black to dark-gray argillaceous slates.............................................. 300 

(f) Covered interval................................................................. 100 

(e) Massive or heavy-bedded gray limestone with conchoidal fracture.................... 40 

[Carboniferous:] 

(d) Light-gray limestone full of small angular cherty masses............................ 80 

(c) Light-gray cherty limestone in 10 to 30 inch bands, fossils abundant.................. 600 

[Age undetermined:] 

(b) Red chert in 6 to 20 inch bands................................................... 300 

(a) Black chert in 4 to 10 inch bands, with rarely a brown or red band.................. 550 

1,970 

The Mesozoic beds are represented by the two divisions e and g of the section. 

The faunal relations of this limestone are considered by Girty to be rather 

with the Gschelstufe of Russia, which underlies the Russian Permian, than with 

that Permian itself. The horizon is, however, the same as that of those formations 

of Alaska which have been assigned to the Permian. The fauna is unlike any of 

the faunas of the Mississippi Valley but resembles that of the McCloud limestone of 

California. (See K 10, p. 376.) Kindle says: 

The fauna of the Pybus limestone is the same which has been previously referred to the 

Permian in Alaska. Dr. George H. Girty, to whom the writer is indebted for the determination 

of the horizons represented by the Carboniferous collections, states, however, that he finds 

"that a greater resemblance exists with the Gschelian stage of the Russian section than with 

the Russian Permian. Provisionally, therefore, I will correlate this horizon with the Gschelstufe, in which occur a great number of equivalent or identical species. This fauna is entirely 

unlike anything in the Mississippian province of the United States, but some of our western 

faunas resemble it." 

Fossils are usually abundant and well preserved wherever the Upper Carboniferous 

limestone is found. The character of this fauna is shown by the list of the species collected 

at Pybus Bay, which has been furnished by Dr. Girty. 

* * * * * * * * 
394 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

In the faunas of the Halleck Harbor section Dr. Girty reports both the upper and lower 

series of the Gschelstufe or upper Carboniferous faunas to be represented. This section, which 

is located on the north side of Saginaw Bay, Kuik Island, follows: 

Feet. 

(b) Light-gray limestone, locally cherty; fossils abundant .................................. 450± 

(a) Black carbonaceous shales, with interbedded dark calcareous sandstones, arranged in belts, 

in which shales and sandstones alternately predominate ............................... 125+ 

At one point the shales and sandstones of division a are seen to pass along the bedding 

directly into cherts similar to those of Pybus Bay. The fauna of this lower division of the 

section cbmprises [many species which have been determined by Girty.] 

P 6-7. NORTHERN BASE OF THE ST. ELIAS RANGE AND WHITE RIVER BASIN, ALASKA 

AND YUKON TERRITORY. 

Moffit and Knopf 600 describe the Carboniferous of the Nabesna-White River 

region as follows : 

Upper Carboniferous deposits are represented in the headwater region of Copper River 

by the Mankomen formation. a This formation is a series of sediments, between 6,000 and 7,000 

feet thick, composed of sandstones, shales, limestones, and tuffaceous beds with included lava 

flows and intruded sheets. These beds were originally described as Permian but should be 

correlated, on both structural and fossil evidence, with the beds along White River and would 

now be called upper Carboniferous. The Mankomen formation, as described by Mendenhall, 

"falls naturally into two divisions-an upper, prevailingly calcareous division, which includes 

somewhat more than half tho total thickness, and a lower, prevailingly arenaceous and tuffaceous division, over 2,000 feet thick." Two principal limestones are present in the upper part 

of the Mankomen formation. The lower, a white massive limestone about 500 feet thick, is 

separated from the upper, which is about 600 feet thick, by several hundred feet of shale. This 

upper limestone is made up of thin beds and is highly fossiliferous, much more so than any 

other parts of the section examined. Fossils were collected at several horizons from the base 

to the top of the Mankomen section, and the correlation with the White River section is made 

on their evidence. The Mankomen resembles the Nabesna-White Carboniferous section in 

the presence of much volcanic material, in which respect both differ from the corresponding 

Yukon Carboniferous. 

A massive limestone, having a maximum thickness of more than 2,000 feet, is found in 

the Chitina Valley and reaches its greatest development on Chitistone River, which heads 

near Skolai Pass. This formation is known as the Chitistone limestone and was correlated 

by Schrader and Spencer in their report in 1901 on the geology of the Chitina Valleyb with 

the Carboniferous limestone of White River. They found no determinable fossils in the Chitistone limestone, and the correlation was based on stratigraphie evidence and lithologic similarity. After studying the Carboniferous formations of the Upper Copper River valley, Mendenhall c questioned this correlation, his objections being based on the seeming absence of 

fossils in the Chi tis tone limestone, on its conformable relation to the overlying Triassic sediments, 

and on its freedom from basic intrusives, all of these features being contrary to the character 

of the Carboniferous sediments of the Mankomen formation. Later work,d however, proved 

the Chitistone limestone to be of Triassic age, but it is suggested that the Nikolai greenstone, 

which conformably underlies the Chitistone limestone in the Chitina Valley, may probably 

a Mendenhall, IV. C., The geology of the central Copper River region, Alaska: Prof. Paper U. S. Geol. Survey 

No. 41, 1906, pp. 40-52. 

b Schrader, F. 0., and Spencer, A. C., The geology and mineral reso_urces of a portion of the Copper River district, 

Alaska, a special publication of the U. S. Geol. Survey, 1901, p. 46. See also Bull. U.S. Geol. Survey No. 374, 1909, 

p. 27. 

c Mendenhall, W. C., op. cit., p. 51. 

d Moffit, F. H., and Maddren, A. G., Mineral resources of the Kotsina-Chitina region, Alaska: Bull. U. S. Geol. 

Survey No. 374, 1909, p. 26. 
CARBONIFEROUS UNDIVIDED. 395 

be the equivalent of some of the upper lava flows referred to the Carboniferous in ·white River 

valley. Proof for this correlation is lacking and will remain so until the upper limit of the 

Carboniferous is determined, but the seeming transition, without interruption, from Carboniferous to Triassic deposits in the Yukon Valley suggests the possibility of such a condition 

holding at the head of White River and that an unconformity between Carboniferous and Triassic 

deposition may not occur there. Whether the volcanic beds occurring between the massive 

limestones of the White and Chitina valleys should be referred to the Carboniferous or Triassic 

may be difficult if not impossible to determine. 

Q 3. SEWARD PENINSULA, ALASKA. 

Carboniferous limestone has been recognized in Seward Peninsula at Cape 

Mountain, near York; a at Baldy Mountain, in the Kougarok mining district; b at 

Cape Deceit, in Kotzebue Sound; c and at Black Mountain, on the lower part of 

Fish River d-in other words, at widely separated localities throughout the peninsula.166 There is strong reason for believing that in addition to these known mapped 

localities some of the areas of limestone in the "unclassified Paleozoic" of Seward 

Peninsula may be of Carboniferous age. In 1909 fossils of either Devonian or 

Carboniferous age were found by Smith and Eakin 768 in dark-colored limestones 

on the eastern flanks of the Darby Range at several places. Other limestones 

associated with schists having characters similar to those of the known Carboniferous areas apparently occur in many places in northeastern Seward Peninsula. 

In 1908 a very poorly preserved fossil from the large limestone area west of 

Casadepaga River suggested possible correlation with the Carboniferous. 

From the wide distribution of Carboniferous rocks in the peninsula it is probable 

that many infolded and infaulted remnants occur in such relations to the other 

members that the structural relations are obscure and involved. All of the known 

Carboniferous has been subjected to deformation, and in some places it has been 

intruded by igneous rocks of the granite family, so that under ordinary circumstances fossils are lacking and the original characters are more or less obliterated 

by secondary structures. 

Q 7. UPPER YUKON AND PORCUPINE RIVERS, ALASKA. 

Brooks and Kindle, 102 who examined the Porcupine-Yukon section m 1906, 

distinguish the following section as Carboniferous: 

Feet. 

Limestone (youngest Carboniferous) __ ....................... _ .. ____ . _________ . _ .... __ . _ _ _ _ _ 200 

Shales, sandstones, and conglomerates, with a basal member of chert conglomerate............. 1,600 

Probable unconformity by erosion. 

Thin-bedded limestone and shale, containing Carboniferous fossils ... ___ ..................... 1,000 

Dlack shale, classed as upper Devonian but comprising the transition to Carboniferous ....... 1,300 

The Carboniferous strata are said to embrace about 2,800 feet of sediment, 

usually not associated with contemporaneous igneous rocks and thus distinguished 

from the Devonian. 

Details of the sections on Porcupine River are given by Kindle, 497a who 

quotes determinations of faunas by Girty and floras by White. They conclude 

a Collections made by A. J. Collier. 

b Collections made by A. J. Collier and E. M. Kindle. 

c Collections made by E. M. Kindle. 

d Collections made by W. C. Mendenhall, F. L. Hess, E. M. Kindle, and P. S. Smith. 
396 INDEX TO• 'fHE STRATIGRAPHY OF NORTH A.\1ERICA. 

' 

that collections obtained from the Porcupine below the Upper Ramparts, including 

both faunas and floras, indicate an early or basal Mississippian horizon, and Girty 

regards it as possible that the whole of Mississippian time is represented. In the 

Upper Ramparts, 40 miles east of the lower stations, is a belt of Carboniferous 

rocks which Girty regards as upper Carboniferous (Pennsylvanian). 

R 3. CAPE LISBURNE AND CAPE THOMPSON, NORTHWESTERN ALASKA. 

The Lisburne formation, once considered to be Devonian, has been shown 

to be Carboniferous by Collier/55 who collected fossils and measured the following 

section: 

Section of Paleozoic rocks in Gape Lisburne region, Alaska. 

Age. Formation. Contact relations. Thickness Lithologic character. (feet). 

Conformity ......... 3,000+ Massive limestones, interstratified with 

white cherts. Extensive coral and 

bryozoan fauna. 

Conformity ......... l,OOO+ Thinly bedded shales, slates, cherts, 

Lower Carboniferous, and limestones. Fauna includes 

Mississippian. Lisburne. brachiopods, trilobites, cephalopods, 

and lamellibranchs. 

Conformity? ....... 500+ Thinly bedded black shales, slates, and 

limestones. Several coral beds. 

Lower Carboniferous flora. Brachiopod and coral fauna. 

Devonian (?). 2,000+ Calcareous sandstones and slates. No 

fossils found. 

Probably the oldest formation of the region consists of heavy calcareous sandstones and 

interbedded calcareous slates, which occur on the west side of the Lisburne Hills, where they 

form the sea cliffs for about 15 miles north of Marryat Inlet, and are exposed for about 10 miles 

along Kukpuk River. The heavy sandstones range in thickness from 1 to 10 feet each, while 

the slaty beds are usually thinner. The massive members often present schistose phases and 

contain secondary mica. The total thickness has not been determined, though it is certainly 

not less than 1,000 feet. * * * 

The age of the formation is inferred from its relations to the Carboniferous beds which 

overlie it with apparent conformity, though no direct paleontologic evidence could be obtained. 

It is certainly older than the Lower Carboniferous and is tentatively placed in the Devonian. * * * 

The Carboniferous rocks lie east of the area of sandstones and slates just described and 

constitute the mass of the Lisburne Hills. * * * 

The contact of these rocks with the supposed Devonian sandstones and slates has been 

·observed at three localities. In two of these localities situated north and south the relation 

seems to be conformable, while in the third, 2 miles farther south of Cape Dyer, the contact 

is a well-defined thrust fault, with the sandstone overlying. 

* * * The general area of undifferentiated Carboniferous * * * includes a diversity of rocks. Along the coast, where the observations were in more detail, three formations 

are differentiated, as follows: (1) A lower formation, consisting of slates, shales, and limestones, containing several coal beds and yielding Paleozoic fossil plants. (2) Overlying the 

coal-bearing beds are black cherts, slates, shales, and cherty limestones containing corals and 

bivalve fossils, the most common being several species of Aviculopecten. (3) Above these 

beds is a great thick;ness of massive limestones, largely made up of coral interbedded with 

massive white cherts. 
CARBONIFEROUS UNDIVIDED. 397 

The shaly members of the series are usually intensely crumpled, while the more massive beds 

present broad, open folds complicated by frequent thrust faults, which make the stratigraphy 

difficult to decipher. 

The coal-bearing formation, which is the lowest, * * * is distinguished from the 

overlying formation by the presence of coal beds and of fossil plants in some of the black shales 

and clays. It is, therefore, essentially a fresh-water deposit. In one instance marine invertebrates have been found in such position as to suggest a possible interbedding of marine sediments with the fresh-water deposits, but as this relation may be due to the infolding of some 

of the overlying formations it can not be accepted as conclusive evidence. The beds are usually 

thin and the formation as a whole is softer than the overlying rocks. * * * 

The middle formation of the Carboniferous series * * * consists of thinly bedded 

black slates, shales, cherts, and cherty limestones and is distinguished from the lower formation, which it resembles in general appearance, by the absence of coal beds or fossil flora of 

any kind, and from the upper formation of the series, first by its lithologic character and 

second by its fauna, which consists principally of brachiopods and mollusks, while that of the 

upper consists principally of corals. * * * 

The upper member of this series [Lisburne formation] consists of massive thick-bedded 

limestones, massive white cherts, and occasional thinner beds of black slate or shale and is 

distinguished from the underlying Carboniferous formations by its lithologic character and its 

fauna, which consists mainly of corals. The contact relation of the upper to the middle formation of the series is conformable in an exposure south of Cape Lewis, * * * but in most 

of the other places where the contact is exposed faulting has occurred. The thickness exposed 

at Cape Lewis and also south at Cape Lisburne can not be regarded as less than 2,000 feet 

and may be much greater. 

Girty a states regarding the age of the Lisburne formation: 

The Pennsylvanian probably occurs there, but the greater part of the beds appear to be 

Mississippian. The Lisburne formation is in the main to be correlated, with little doubt, with 

the Mountain limestone of Europe and the upper Mississippian of the middle United States. 

There appears to be an older series, however, which correlates with the lower Mississippian. 

We have from it a few invertebrates suggesting this conclusion, among them Lepttena rhomboidalis, which is not known above the Burlington limestone, of the Mississippian. 

The section exposed along the coast south of Cape Thompson was examined 

by Kindle,S00 who says: 

The lowest beds exposed at Cape Thompson outcrop along the beach immediately north 

of the cliffs. The rocks exposed in these beach outcrops and the accessible or northern 

portions of the cape cliffs are indicated by the following section: 

Section at Cape Thompson. 

Feet. 

(d) Light-buff or cream-colored limestone with numerous fossils. Strike about north-south, 

dip variable, mostly E. 25° to 90°, complicated toward the south .................... 500+ 

(c) Black and buff thin-bedded limestone, the former predominating. Productus and large 

crinoid stems abundant .............................................................. 380 

(b) Bluish-gray to black fissile shale with abundant plant fragments. Dip E. 80° to 90°, 

strike N. 15 ° \V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280 

(a) Very thin bedded lead-gray sandstone, with occasional bands of brown ferruginous chert 

and films of coal. Plant fragments abundant. Strike N. 15° W., dip E. 86° to 90° .... 140 

The lower 400 feet of the section appears to contain no invertebrate fossils. All or nearly 

all of these beds represent nonmarine sediments. Plant remains in various stages of maceration occur through most of the shales and sandstones below the limestone. Plant fossils were 

obtained from both a and b of the section and numbered respectively lots 5289 and 5290. These 

were submitted to Dr. David White, whose report follows. 

a Letter of June 20, 1909, from the field. 
398 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

''Lot 5289. This lot consists of three fragments of coarse gray sandstone bearing carbonized impressions of pieces of partially decorticated stems. The characters of the very 

imperfect impressions point toward a close affinity with Lepidodendron corrugatum. 

''Lot 5290. This lot includes two small packages of wavy, black carbonaceous shale splitting 

in thin laminre. This shale contains many fragments of leaves of Lepidodendron, and unidentifiable, decorticated stem fragments of several kinds, together with several imperfect remains 

in a better state of preservation. The latter represent Sphenopteris jrigida Heer, twigs of 

Lepidodendron veltheimianum as generally identified in the European and Arctic floras, with 

a cone fragment possibly belonging to the same species, and portions of a Lepidophyllum 

very close to Lepidophyllum juisseense Vaff. There are also present several fragments of a 

cyclopterid type; these are so incomplete that it is not really possible to decide whether they 

represent (a) rachial pinnules of Neuropteris; (b) some large, broad pinnuled Aneimites; or, 

(c) pinnules of Cardiopteris. I am inclined to refer them to the latter genus. 

''The plant remains from Cape Thompson are so fragmentary and meager as to determinable species as ~ot to permit a close determination of the age of the beds. They appear to 

be Mississippian and probably represent a stage in the lower part of this division. They may 

even come from the basal member thereof.'' 

These plants evidently belong to the same horizon as that from which Collier obtained 

Carboniferous plants at Cape Lisburne. Concerning the Cape Lisburne plants, Dr. White's 

reporta contains the following statement relative to their age: 

''These fossil plants are evidently of Carboniferous age. Owing to the marked scarcity 

of filicate elements the testimony of the collection is less direct as to precise age than might 

otherwise be the case. However, from the evidence in hand I am forced to conclude that the 

plant-bearing terrane is Mississippian, and it appears probable that it is referable to the lower 

portion of the Mississippian. The flora * * * is very closely related to that from Bell 

Sound and Klass-Billen Bay in Spitzbergen. It seems to be slightly younger than the Ursa 

flora." 

Above the plant-bearing beds only marine fossils are seen. The limestones which follow 

the sandstone and shales carry an abundant fauna. Corals are quite abundant in the upper 

division of the limestone series. 

Dr. Girty furnished a list of fossils from these beds, on which Kindle comments as follows: 

While some of the collections are much less numerous than others, it is probably safe 

to refer them to a single fauna, which is without much question of lower Carboniferous or 

Mississippian age. It is true that some of the forms appear to be allied to species in the Burlington and Keokuk of the Mississippian section, but I believe that the beds furnishing these 

fossils should correlate only with the upper :Mississippian. Indeed, the faunas are especially 

suggestive of the well-known fauna of Spergen Hill, which is known to have been rather 

extensively distributed toward the northwest. 

I have long been of the opinion that our upper Mississippian correlates in a general way 

with the Mississippian limestone of Europe and Asia, but the evidence has been more or less 

indirect and general in character. The present faunas are especially interesting, because they 

seem to show to some extent a mingling of the two faunas. The Mountain limestone element 

is represented by the abundance of Lithostrotion, and other features could probably be pointed 

out by one familiar with the European faunas. The coral fauna of the Mountain limestone 

is already known in Alaska, especially at Cape Lisburne, but it has not there, so far as known, 

the admixture of Mississippian types. 

In connection with the interesting resemblance of the Cape Thompson fauna to the Spergen 

Hill fauna pointed out by Dr. Girty, reference may be made to the minute character of many 

a Collier, A. J., Geology and coal resources of the Cape Lisburne region, Alaska: Bull. U.S. Geol. Survey No. 278, 

1906, p. 22. 
CARBONIFEROUS UNDIVIDED. 399 

of the brachiopods. * * * In this feature the fauna strikingly resembles the depauperate 

Spergen Hill fauna. The presence in the fauna of a small specimen of Pentremites or a closely 

allied genus is also worthy of note in this connection. Although extremely abundant in the 

Mississippi Valley, this blastoid has been recognized at but two localities in the Rocky Mountains, and in both of these occurrences it is associated with a fauna closely resembling the 

Spergen Hill fauna. 

R 5. ENDICOTT RANGE, ALASKA. 

The Fickett "series," a very thick sequence of strata comprising a great variety 

of sedimentary rocks, was observed by Schrader in traversing the Endicott Range, 

longitude 150°-155° west. Lower Carboniferous fossils occur in pebbles found in 

gravels derived from it. Brooks 101f summarizes the observations as follows: 

During his exploration of the Anaktuvuk, in northern Alaska, Schrader traversed a belt of 

phyllites, chloritic schists, limestones, slate, sandstone, quartzite, grit, and conglomerates 

about 50 miles in width. In spite of the heterogeneity of these rocks and the uncertainty of their 

interrelations, the hasty character of the field observation made it necessary to group them in 

one formation, the Fickett series. The only fossils encountered were in the stream gravels and 

were evidently derived from beds in this series, and on this evidence the entire succession was 

provisionally assigned to the Lower Carboniferous. The Fickett overlies the Skajit (Silurian~) 

on the south by an unconformable overlap, and on the north it is cut off by a fault from the 

Lisburne (Carboniferous). Schrader states that the Fickett and Lisburne series bear an unconformable relation. 

The Fickett series, which may have a thickness of 8,000 to 10,000 feet, has a basal member 

made up of shale, slate, and limestone, succeeded by quartzite, grit, and conglomerate, and then 

by slate and micaceous sandstone. It is in this part of the section that the limestone is supposed 

to occur which yielded the Carboniferous fossils of the stream gravels. A still higher member 

includes sandstone, limestone, quartzite, schists, slate, and conglomerate, succeeded by quartz 

schists and green chloritic schists, the latter often cut by quartz veins. It is not made clear why 

the most highly altered members should occur at the top of the series, for while it is true that 

these metamorphosed rocks lie near one of the axes of intense folding, it would be expected that 

the same metamorphic effect would have been noted at the northern limit of the section, where 

another locus of extreme deformation was observed. 

8-T 10-14, T 15, AND U 17-20. BARING (OR BANKS) LAND, PARRY ISLANDS, ELLESMERE 

LAND, AND GRINNELL LAND. 

Haughton's description of the Arctic Carboniferous is quoted by Low 550g as 

comprising the principal known facts regarding the Parry Islands: 

The southern boundary of the Carboniferous sandstones with their included coal seams 

crosses the southern part of Banks Island in a north-northeast direction, and they consequently 

cover the northern two-thirds of that island, while the extreme northwest portion of Victoria 

Island is also occupied by these rocks. The western Parry Islands, on the north side of Melville Sound, are almost wholly formed of these rocks, whose southern boundary strikes northeast 

across the northern half of Cornwallis Island. They are found again in Grinnell Peninsula, the 

northwest portion of North Devon, and again on the western side of Ellesmere, in the vicinity of 

Store Bjornekap, being probably largely developed in the northeast part of that great island. 

These rocks are described as follows by Prof. Haughton: 

"The Upper Silurian limestones, already described, are succeeded by a most remarkable 

series of close-grained white sandstone, containing numerous beds of highly bituminous coal 

and but few marine fossils. In fact, the only fossil shell found in these beds, as far as I know, 

in any part of the Arctic Archipelago, is a species of ribbed Atrypa, which I believe to be identical 

with the Atrypajallax of the Carboniferous slate of Ireland. These sandstone beds are succeeded 

by a series of blue limestone beds containing an abundance of marine shells, commonly found in 
400 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

all parts of the world where the Carboniferous deposits are at all developed. The line of junction 

of these deposits with the Silurian on which they rest is northeast to east-northeast (true). 

Like the former, they occur in low, flat beds, sometimes rising into cliffs, but never reaching the 

elevation attained by the Silurian rocks in Lancaster Sound." 

In regard to Ellesmere Land, Low ssoh quotes Schei 706 as follows: 

The Carboniferous rocks of western Ellesmere appear to be isolated areas resting upon the 

underlying Devonian and in turn covered by Mesozoic rocks. Schei describes the area at Store 

B.iornekap as consisting in its lowest part of beds of brownish-gray hard fossiliferous limestone; 

higher up, of a white pure limestone, flinty limestone, and pure flint strata, richly fossiliferous, 

among the fossils being Lithostrotion sp., Fenestella sp., Streptorhynchus crenistria, Rhynchonella 

(Pugnax) sp., Spirifer cfr. ovalis, cuspidatus, mosquensis, Productus cfr. semireticulatus, costatus, 

punctatus, cora, etc. 

Lists of the fossils collected by various expeditions up to 1860 are given by 

Haughton 414 and republished in the "Arctic manual," 1875, edited by T. Rupert 

Jones. 472 

The lower division of the Arctic Carboniferous, which consists of sandstones and 

shales, has furnished a few plants from localities in Melville and Bathurst islands. 

Heer assigned the formation to the Ursa stage and correlated it with similar 

deposits in Bear Island and Spitzbergen. David White, however, regards the 

typical Ursa as Devonian at latest, and reports that the plants from the Arctic 

Archipelago represent the lower Carboniferous. The formation is probably related 

to the Mississippian of the section at Cape Lisburne, Alaska. 

The upper division of the Carboniferous in the Arctic is the limestone from 

which the marine invertebrate fossils have been obtained. Girty has examined 

the literature and has furnished the following statement: 

The most extensive fauna reported was obtained at Depot Point in Grinnell Land. In it 

have been identified Fusulina hyperborea, Stylastr::ea inconferta, Lithostrotion basaltiforme, 

Zaphrentis ovibos, Olisiophyllum tumulus, Syringopora aulopora, Fenestella arctica, Prod1tctus 

semireticulatus var. jrigidus, and Spirifer lceilhavii. 

This fauna, composed as it is largely of corals, is difficult to correlate satisfactorily. A suggestion is found in the fact that Tschernyschew statffi that the fossil cited by Haughton under 

the name Spirifer lceilhavii undoubtedly belongs to Spiriferella saran::e, which is a species of the 

Gschelian fauna of Russia. Some of the other Arctic brachiopods show similar alliances and 

this is also conspicuously the case with certain of the Alaskan faunas. It seems highly probable, 

therefore, that the GschelianJauna was distributed over this region. 

Some of the species cited from Depot Point have been found also at other stations, one or 

two at a time. In addition the following have been identified apparently from the same limestone in the Parry Islands: Syringopora geniculata, Productus cora, Productus sulcatus var. 

borealis, and Spirifer arcticus. 

Still another Carboniferous formation with invertebrate fossils is found in Ellesmere Land. 

In the preliminary notice Schei refers his fauna to the upper Carboniferous and if his identification of Spirijer mosquensis, a leading fossil of the upper Carboniferous of Russia, is to be trusted, 

the horizon is possibly the Mosquensis zone of the Russian section, which comes in at the base of 

the upper Carboniferous. The position of the Ellesmere occurrence would then be below the 

horizon of the Carboniferous limestone of the Parry Islands and above the phytiferous beds. 

Whether the Spirifer mosq1tensis horizon occurs in the Parry Islands can not be determined 

from the fragmentary paleontologic evidence thus far obtained. There is yet no clear suggestion 

of two distinct faunas in the species cited from the Parry Islands and from Grinnell Land, 

nor does the fauna from those areas present any close similarity with that from Ellesmere Land., 
Color, light French blue. 

Symbol, 13. 

CHAPTER IX. 

MISSISSIPPIAN. 

Distribution: Guatemala; eastern R orth America from Oklahoma to Nova Scotia; present but 

included in the "Carboniferous undivided" (14) in the Cordillera, Arctic region, and 

Newfoundland. 

Content: "Lower Carboniferous" limestones and their equivalents where they are separated 

on the map from Pennsylvanian coal measures. In Guatemala the Santa Rosa formationMississippian areas. 

D 15-16 ....................... Guatemala and Chiapas. (See Chapter X, p. 425.) Page. 

I 16 ............................ Alabama and Tennessee.................................................. 401 

J-K 15 ......................... Iowa, Illinois, Missouri, Arkansas, and Oklahoma........................... 407 

J-K 16 ......................... Kentucky and Indiana .................................................. _ 412 

J-K 17 ......................... Ohio aRd eastern Kentucky............................................... 414 

J-K 17-18 ...................... Pennsylvania, Maryland, West Virginia, and Virginia....................... 417 

K-L 16-17 .................... Michigan................................................................ 420 

L 20 .......................... Nova Scotia and adjacent New Brunswick. (See Chapter VIII, pp. 384-386.) 

M 20 ........................... Bonaventure County, Quebec........................................ 423 

I 16. ALABAMA AND TENNESSEE. 

In their southern extension into Tennessee and northern Alabama the Mississippian strata were described by Safford 687 a as the "Siliceous group" (regarded by 

him as equivalent to Burlington, Keokuk, and St. Louis) and the "Mountain limestone" (regarded by him as equivalent to Chester), and these terms were used in 

Alabama. The latest classification for western Tennessee is that given by Hayes 

and Ulrich 431b in the Columbia folio, as follows: 

Mississippian formations in western Tennessee. ---

Mappable lithologic equiv- Safford and Killebrew 

Generalized time scale for alents in the Columbia (Elements of geology Safford (Geology of Tennessee, 

central North America. quadrangle. of Tennessee, 1900). 1869). Middle Tennessee. 

Middle Tennessee. 

Chester . (Not present.) Mountain limestone. Mountain limestone. 

.,..--. 

p.::: Lithostrotion bed or St. 2-~ St. Louis. St. Louis limestone. St. Louis limestone. 

Q)0.. Louis limestone. 

=s-~ ·-~-

ooo Keokuk. s i 1 i -

..o'Fi3 >-<OO ceo us 

oe_ "'''"' Burlington. group. Tullahoma formation. Tullahoma formation. Lower or Protean mem- ber. 

Kinderhook. 

48011 °-12~-26 401 
FIGURE ll.-Sketch map showing the distribution of Mississippian rocks that are separately represented on the 

geologic map of North America and the key to references in the text. 

402 
MISSISSIPPIAN. 403 

The strata are thus described: 

Tullahoma formation.-This formation consists chiefly of siliceous shales and limestones, but 

the lowest member is a calcareous shale, generally a grayish green or pale blue but occasionally 

dark, varying from nothing to perhaps 30 feet in thickness. * * * The fossils, though 

chiefly of undescribed species of Ostracoda, indicate very early Mississippian age. * * * 

A strongly siliceous and argillaceous limestone that weathers into a cherty, shalelike material occurs stratigraphically above the calcareous shale but usually constitutes the ordinary 

base of the formation. Simile"r strata, in one place more shaly, in another more calcareous, 

and generally with heavier chert, continue to the top of the formation, which has a maximum 

thickness of about 250 feet. Usually it is much less, especially in the southeastern quarter of 

the quadrangle. * * * 

Excepting in the basal shales, specifically recognizable fossils are extremely few in this 

formation. Here and there the heavier chert blocks .contain large crinoid stems in abundance, 

and occasionally a brachiopod cast, indicating the Burlington or Keokuk horizon of Iowa and 

Illinois. 

St. Louis limestone.-This, the latest or youngest formation exposed in the quadrangle, 

consists in the main of a thick bed of limestone, gray to blue in color, and associated with considerable chert. * * * The fossils are mostly small and consist mainly of Bryozoa and 

brachiopods more or less characteristic of the ""Warsaw horizons" of Illinois, Indiana, and 

Kentucky, which have been referred to various ages. Above these heavy layers come the 

more characteristic St. Louis fossils, like Melonites and Lonsdaleia, or as the latter is generally 

called, Lithostrotion canadense. 

In 1894 the Alabama section of the Mississippian was thus classified by Smith746 : 

Mountain limestone: 

(a) Bangor limestone and Hartselle sandstone. 

(b) Oxmoor shale and sandstone. 

(Chester.) 

Fort Payne: 

(a) Tuscumbia (St. Louis). 

(b) Lauderdale (Keokuk, etc.). 

This classification has since been revised and modified. The latest statement 

is by Butts, 107b as follows: 

Overlying the Devonian black shale unconformably are rocks of Mississippian or lower 

Carboniferous age. At the base of the Mississippian rocks, throughout the whole region, is 

the Fort Payne chert; this is succeeded in Brown and Murphrees valleys by the Bangor limestone, with the included Hartselle sandstone member, and by an overlying shale which is correlated on stratigraphic and lithologic grounds with the Pennington shale to the north. At 

the southern end and along the east side of Blount Mountain, and along the east side of Shades 

Valley, the Pennington shale is overlain by shales and sandstones to which the name Parkwood 

formation is here given. South of Boyles Gap in Opossum Valley and south of Oxmoor in 

Shades Valley the Bangor limestone runs out and is replaced by black and gray shales similar 

to the Floyd shale to the northeast. Because of its stratigraphic position and lithologic similarity this shale will be called Floyd shale in this report. South of Boyles Gap and Oxmoor, 

therefore, the Mississippian rocks above the Fort Payne chert consist of the Floyd shale 

(including the Hartselle sandstone, which persists after the thinning out of the Bangor limestone 

and thus locally becomes a member of the Floyd shale) and the Parkwood formation above the 

Floyd. The Floyd shale is thus the equivalent of the Bangor limestone and the Pennington 

shale. In reports of the Alabama Geological Survey the Floyd shale and the rocks comprising 

the Parkwood formation have been treated together as the "Oxmoor or shale and sandstone 

phase" of the upper part of the lower Carboniferous rocks, and the Bangor limestone has been 

called the "Bangor or limestone phase" of the same rocks, the two phe.ses being regarded as 

contemporaneous. 
404 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

As a result of the writer's study of the geology of the region, however, the conclusion has 

been reached that only the Floyd shale and the rocks included by the Alabama Survey in the 

"Bangor or limestone phase" are contemporaneous. The Parkwood formation of Shades 

Valley and Blount Mountain is absent from the section in Murphrees and Brown valleys, having been eroded west of Birmingham Valley before the deposition of the Pottsville or ''Coal 

Measures," so that they rest unconformably on the Pennington shale. 

The variations in the stratigraphy of the Mississippian formations above the Fort Payne 

chert are shown in the sections below: 

Section of Mississippian rocks above the Fort Payne chert in Brown and Murphrees valleys. 

Pottsville formation. Feet. 

Pennington shale ...... __ .... __ ... __ ............................ __ ............ __ .......... _ 100 

Bangor limestone: 

Limestone ........................................................................ _ . _ . 350 

Shale .................................................. _ ......... _ .. _ ... _ ....... _ ... _ . 30 

Sandstone (Hartselle member) ....................................... _. __ ...... ___ .. _ ... 100 

Shale .................. _ .. ____ .. _._._. __ .. ____ .. __ ...... __ ... _ ...... _ ... _._. __ ........ 50 

Limestone ............. _ ......................................................... _ . _ . . 160 

Fort Payne chert. 

Section of Mississippian rocks above the Fort Payne chert near Irondale. 

Pottsville formation. 

Parkwood formation, shale and sandstone ................................................. . 

Pennington shale, dark, calcareous (?) ................................................... . 

Bangor limestone: 

Limestone ......................................................................... . 

Shale, soft, dark, calcareous (?) ....................................................... . 

Sandstone (Hartselle member) ....................................................... . 

Shale, dark, calcareous (?) .......................................................... . 

Limestone ......................................................................... . 

Fort Payne chert. 

790 

Feet. 

2,000 

292 

317 

39 

117 

97 

88 

2,950 

Still farther south, in the vicinity of Readers Gap, borings show only dark shale, probably 

calcareous, in the 500 feet immediately over the Fort Payne chert. The well logs are corroborated in the main by all that can be seen of the formation. South of Boyles Gap and 

Oxmoor good sections and accurate measurements of the rocks under discussion are not obtainable. A compiled section for the region south of Oxmoor, probably a close approximation, 

is as follows: 

Pottsville formation. 

Parkwood formation, shale and sandstone ................................................. . 

Floyd shale: 

Shale, some calcareous, sandstone, and limestone lenses ............................... . 

Sandstone (Hartselle member) ....................................................... . 

Shale, dark, calcareous ......................................................... -.----. 

Fort Payne chert. 

Feet. 

2,000 

700 

100 

200 

3,000 
MISSISSIPPIAN. 405 

Sections of rocks below the coal measures. 

A. In Murphrees and northern part of Birmingham valleys. 

-~-·-

System. Formation. I Thickness (feet). General character. 

Parkwood formation. Knife-edge to Prevailingly gray shale and sandstone; no calcareous beds 

00 2,000. Fossils very scarce. 

-~ ... 

Q) 

00 

1':1 Pennington shale. 60-300 Gray, green, and red shale, with a little chert and som ~ sandstone and conglomerate. Highly fossiliferous . ..... 

>:>. 

>:>. ..... 00 

.;!l Prevailingly thick-bedded light-gray crystalline lime 00 

.;!l 

e Bangor limestone. 700 stone. Hartselle sandstone member and shale in midst 

m Merges through sparingly chert:y: limestone into For 

:::: Payne chert below. Highly foss1liferous. 0 

... (Prevailingly fine-grained firm sandstone, locally coars (Hartselle sandstone member). (100) J!l and friable.) ·s 

t 

e 

0 

~ Fort Payne chert. 200 Mostly thin-bedded chert; locally thick bedded at bottom. 

Generally fragile. Fossiliferous. 

Unconformity ---

l'i 

~ Chattanooga shale and Frog Black carbonaceous shale, locally sandstone below, with 

·s 

I 

Mountain sandstone. phosphate nodules and fossils. 0 

:> Unconformity. Q) 

A ·----

B. In southern part of Birmingham and Shades valleys. 

[Section below Floyd shale is same as in A.] 

----------------------,------.------------------------------

Formation. 

----------~----~--~ 

Parkwood formation. 

Thickness 

(feet). 

1,500-2,000 

General character. 

Same description as in A. 

---------------~ --- -- - ------·--------~-----------

Floyd shale. 1,000 

Fort Payne chert. 

Gray, dark, and black shale, calcareous at horizons. 

Contains beds of sandstone and lenses of limestone. 

Highly fossiliferous throughout. Equivalent to the 

Bangor and Pennington formations. 

Hartselle sandstone member. 
406 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Stevenson 794 e comments on the fact that the formations represented in Alabama 

are recognizable far to the north and northeast, although they undergo very material 

lithologic changes, and he thus sums up the relations: 

Beginning at the south, on the western outcrop, one finds, ascending, the Tuscumbia, 

limestone and markedly siliceous; the Hartselle, sandstone with shales and limestones; and the 

Bangor, limestones more or less argillaceous. These three divisions retain their characteristics 

across Tennessee into Kentucky, the Bangor meanwhile becoming more argillaceous in northern 

Tennessee, where its upper portion has been identified with the Pennington shale. In Kentucky the Tuscumbia and Hartselle are taken together as the St. Louis, but they retain the 

Tennessee features, one of the Hartselle sandstones being persistent. The Bangor becomes 

very shaly and, like the Tuscumbia, thins out northward more rapidly than the Hartselle, so 

that the last alone is present in central Ohio, where Prof. Andrews called it the Maxville. 

Along the eastern outcrop one .find:,; greater variation, for outlying areas toward the southeast reveal something of the conditions existing along the old shore line. But those areas may 

be neglected in this connection. Following the border of the principal areas, one finds the 

Tuscumbia, Hartselle, and Bangor sharply defined in Alabama, with the same features as on 

the western side. In Tennessee the Tuscumbia is easily recognized in the upper portion of 

Mr. Hayes's Fort Payne, while at least one of the Hartselle sandstones is persistent in southern 

Virginia; but the Bangor, the upper portion of Mr. Hayes's Bangor limestone, becomes increasingly argillaceous northward, so that frequent reference is made to its tendency to weather into 

shale. Toward the Virginia line it becomes almost wholly shale and sandstone, while it 

increases greatly in thickness, so that Mr. Campbell has separated the Pennington shale from 

the limestone which he calls Newman. The enormous increase in thickness of the section, due 

to increase of land detritus, renders exact tracing difficult for a little way in southwest Virginia, 

the more so since detailed descriptions have not been published. The Bangor evidently becomes 

wholly shale and sandstone before New and Greenbrier rivers are reached, where Fontaine and 

Campbell found ~o great a mass of shales with insignificant streaks of limestone. The persistence of the Hartselle sandstone at the bottom of the shales or near the top of the limestone is 

shown by many of the oil records and along the outcrops almost into Pennsylvania. The 

upper limestone of Virginia, Maryland, and Pennsylvania is the Hartselle. The Tuscumbia 

retains its siliceous character throughout, though losing its chert in Virginia and becoming 

merely a siliceous limestone; this feature, along with a curiously current-bedded structure and 

a peculiar whiteness when crushed, characterizes it thence into Pennsylvania, where by several 

of the geologists it was termed the Siliceous limestone. 

The correlation seems to be: 

Shenango [shale].-Bangor of McCalley in Alabama; upper portion of Bangor of Hayes in Tennessee; upper portion 

of Safford's Mountain limestone in Tennessee; Chester of Kentucky geologists (Second Survey); Pennington and top of 

Newman of Campbell in Tennessee and southwest Virginia; Umbra! shales of Fontaine; Canaan shales of Darton; 

Greenbrier shale of W. B. Rogers; Mauch Chunk shale of Maryland; Mauch Chunk of Pennsylvania in part; absent 

from most of Ohio; Shenango shale of I. C. White in northeast Ohio and northwest Pennsylvania. 

1lfaxville.-Hartselle of Alabama; greater part of Bangor in Tennessee; lower part of Mountain limestone in Tennessee; greater part of upper Newman and of upper Greenbrier in Virginia; upper Umbra! and upper Mauch Chunk 

limestones in Pennsylvania; Maxville of Ohio; upper St. Louis of Kentucky. 

Tuscumbia.-Tuscumbia of McCalley in Alabama; Lithostrotion of Safford in Tennessee; upper part of Fort Payne 

in Tennessee; lower part of St. Louis in Kentucky; lower Newman and Greenbrier in Virginia; lower [part] of Greenbrier in Maryland; Siliceous limestone of Pennsylvania; absent in Ohio except at Kentucky border. 

The term Shenango is the earliest applied definitely to the latest division. Though Dr. 

·white's Shenango shales have been spoken of as representing the whole of the Mauch Chunk 

sedimentation, it will be shown in the next chapter that they represent practically only the 

sedimentation of the closing epoch. The name Maxville \vas given by Prof. Andrews in 1870 
MISSISSIPPIAN. 407 

and therefore antedates Hartselle by many years. Tuscumbia, being a geographical term, 

will have to replace the much older Lithostrotion of Prof. Safford. 

The fossils from the Shenango appear to be those characteristic of the Chester of the Mississippi basin. Forms belonging to that epoch have been collected in Pennsylvania, Virginia, 

Kentucky, and elsewhere. Fossils collected by Andrews in 1869 from the Maxville localities 

in Ohio and by Stevenson in 1870 from the same limestone in West Virginia were submitted to 

Mr. F. B. Meek, who pronounced them distinctly Chester. Prof. R. P. Whitfield afterward 

figured and described the Ohio forms, referring them practically to the same horizon. Still 

later, in 1901, Stevenson collected carefully at a locality in Fayette County of Pennsylvania 

and submitted the specimens to Mr. Weller, who found that the fauna contains some St. Louis 

as well as the Chester forms. There is, however, practically no change in the fauna from the 

bottom to the top of this locality, the same forms, with two or three exceptions, being found 

throughout. The Chester forms predominate, and of those belonging to the St. Louis some 

lived on into the Chester at typical localities within the Mississippi basin. The same fauna 

occurs in Randolph County of east-central 'Vest Virginia and in Washington County of Virginia 

at the Tennessee border. In Tennessee and Alabama the Maxville (Hartselle) is clearly Chester. 

The Kentucky geologists of the Second Survey make the Maxville the upper part of their St. 

Louis, but it overlies the Lithostrotion bed, the lower part of their St. Louis. No list is given 

of the fossils which lead to classification of the limestone as St. Louis. 

The Tuscumbia is practically nonfossiliferous at most localities in Pennsylvania. In 

Tennessee and Alabama, as well as in Kentucky, Lithostrotion canadensis is the characteristic 

fossil, and it is associated with other forms belonging to the St. Louis. 

Girty a comments on the correlation which Stevenson thus suggests as follows: 

In the correlations quoted from Stevenson there appears to be an error. Stevenson there 

places the Shenango above the Maxville and the Tuscumbia, whereas on page 42 he assigns the 

Shenango to the horizon of tho Burlington and Keokuk and correlates it with the Logan which 

underlies the Maxville in the Ohio section. It seems almost certain that in the former case 

he is speaking of the Shenango shale of White and in the latter of the underlying Shenango 

sandstone of the same author. There can hardly be a doubt that the Shenango sandstone is 

the same in part at least as the "Logan group" of Ohio (now the Blackhand and Logan formations). The correlation of the Shenango sandstone with the Blackhand and of the Logan with 

the Shenango shale is suggested by the lithologic sequences. Professor Stevenson, however, 

appears to consider the Shenango shale as occupying a much higher position. He places 

it equivalent to the upper Mauch Chunk and above rather than below the Maxville. If this is 

so, there must be an important interval between the Shenango shale and the Shenango sandstone representing the lower and middle Mauch Chunk, so that it would be inadvisable to 

include the shale and sandstone under the same formation name. If Stevenson is right, the 

sandstone alone should be called Shenango. 

Some doubt also is involved in the use of the name Tuscumbia for the lowest of these 

three formations, with which he aligns the Fort Payne of Tennessee. I have good faunas of 

both the Fort Payne of Alabama and the overlying Hartselle of the same area and I also have 

a collection from the limestone at Tuscumbia, Ala., which is without much question the Tuscumbia limestone. The Tuscumbia fauna is decidedly different from either the Fort Payne 

or Hartselle faunas and much more closely allied to that of the overlying Bangor. 

J"-K 15. IOWA, ILLINOIS, MISSOURI, ARKANSAS, AND OKLAHOMA. 

The region here comprised is that in which the Mississippian is typically developed as a great limestone, which is divided locally into several formations according 

to the nature of the strata, and these are grouped according to their fossil contents. 

a Comment on manuscript. 
408 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

In originally defining the Mississippian Williams 932 discussed previous attempts at 

correlation and proposed the following classification: 

Recent studies of the fossils, their original grouping into local faunas, and their association 

in other parts of the province have' led me to recognize three fairly well differentiated faunas 

in the Mississippian series, the subdivisions of which are believed to be local and therefore very 

unsatisfactory for purposes of correlation. 

The following table sets forth the proposed classification and nomenclature: 

Structure scale. Time scale. 

Chester stage ___ .. } · 

St. Louis stage. . . . .................. : .. ........... ____ .... Genevieve age. 

Warsaw stage. __ ._ 

Mississippian series_ _ ~~~l~~~~~a:;~g~: :} ___________________ .... _ .. ___________ ... _____ Osage age. 

Kinderhook stage,{Chout_eau limestone ...... : ... ____ } 

including. ______ V~rm1cular shale and sandstone .. _. _______ .Chouteau age. 

Lithographic limestone ...... _. __ _ 

The Chouteau age is the age of the Chouteau group of Broadhead. The Osage age is the 

age of the fauna of the Burlington and Keokuk formations, which are locally distinguishable 

but in the sections on the northwestern, western, and southwestern flanks of the Ozark uplift 

are so blended that it seems impracticable in most cases to differentiate them. The name is 

suggested by the fact that the Osage River drains the region in which this confusion of the two 

faunas is clearly exhibited. The Genevieve age is the age of the fauna of the Archimedes group 

of Shumard. 

The name is suggested by the fact that Shumard first called attention to the union of the 

several formations in which the common fauna prevails in his description of the geology of 

Ste. Genevieve County, Mo. The name he applied was Archimedes group, but this is not a 

satisfactory name, and in the county of Ste. Genevieve and on the eastern and northeastern 

margins of the Ozark uplift, above and below this county, are found the typical outcrops of the 

individual formations included in the group. 

The term Mississippian is now generally used for the lower Carboniferous in 

North American stratigraphy, but the definition of its limits and the classification 

of its subdivisions have been subjects of continued research and discussion. Chamberlin and Salisbury 134 give the following list of divisions in the Mississippian 

provmce, together with those of other sections of the eastern interior: 

Subdivisions of Mississippian series. 

Mississippi River States.a Ohio.b Pennsylvania. c I Maryland.d 

4. Kaskaskia or Chester. r 6. Moxvill• Logan. 3. Mauch Chunk. 

3. St. Louis. 5. Blackband. 2. Mauch Chunk. 

2. Osage or Augusta (including the Bur- 4. Cuyahoga. 2. Greenbrier. e 

lington, Keokuk and Warsaw). 3. Sunbury. 

L Kinderhook or Chouteau. 2. Berea grit. 

l. Bedford. 1. Pomno. L Pocono. 

a Williams, Bull. U. S. Geol. Survey, No. 80, p. 169. St. Genevieve was the term applied by Williams to the 

upper part of the Mississippi system. b Prosser, Jour. Geology, vol. 9, p. 215; vol. 11, p. 520. See also Am. Geologist, vol. 34, p. 335. c Pennsylvania Repts. and folios of U. S. Geol. Survey. d O'Harra, Maryland Geol. Survey, Allegany County, pp. 109-113. e The Greenbrier is absent in eastern Pennsylvania. It comes in as a lentil of limestone farther west, and thickens 

southward, becoming an important formation in Virginia, largely replacing the Mauch Chunk shale. See BrownsvilleConnellsville folio, U. S. Geol. Survey (Campbell). 
MISSISSIPPIAN. 409 

The latest statement on the Mississippian is by \Veller, 886 whose full discussion 

may be abstracted as follows: 

Weller distinguishes (1) a "southern Kinderhook or Chouteau fauna," partly 

derived from the Devonian (showing relationships to the Hamilton fauna) and 

partly composed of "a new element from some unknown region." "The return 

of this fauna into the Mississippi Valley basin marks the opening of the Kinderhook 

epoch and the Mississippian period." This southern fauna is well developed in 

southern Indiana and Illinois, in the Rockford limestone of the Indiana State 

reports. 

(2) A northern Kinderhook fauna, differing markedly from the southern, 

typified by the "Chonopectus" sandstone and developed in Iowa and northern 

Illinois, north of the "Kankakee peninsula." This northern fauna is related to 

the Chemung faunas of the eastern upper Devonian. The southern and northern 

Kinderhook faunas, though apparently contemporaneous within comparatively 

narrow limits, occupied distinct faunal provinces as regards invertebrate life. A 

fish, Ptyctodus calceolus, was common to both. 

During the progress of Kinderhook time the sea was encroaching from both the north 

and the south, until before the close of the epoch free communication was established between 

the earlier separated provinces, and the fauna of the southern province became the dominant 

type throughout the entire Mississippi Valley basin. * * * It is evident that the arrangement of the Kinderhook formations into three successive divisions, the Louisiana, Hannibal, 

and Chouteau, as has usually been done, does not express the proper relationships of the 

faunas. The Chouteau fauna, in some of its expressions, is without doubt as old as the Louisiana fauna, and it is as impracticable to make one continuous section to contain all of the 

Kinderhook formations as it would be to make a standard Devonian section to include the 

formations of New York and Iowa. 

East of the Cincinnati arch the early Mississippian formation (Bedford shale) 

carries a fauna which resembles that of the southern Kinderhook. The succeeding 

formations of the Waverly group in Ohio are similarly related, but in the north 

occur forms (Paraphorhynchus) which suggest connection with the northern Kinderhook also. 

West of the Cincinnati axis the union of the northern and southern provinces 

gave rise to an extended sea and conditions favorable to the deposition of limestones (Burlington and Keokuk) forming the Osage group, characterized by its 

crinoids. Succeeding formations in the Mississippi Valley basin constitute the 

Warsaw, Salem [Spergen], St. Louis, and Ste. Genevieve limestones. Unconformities follow the Salem [Spergen], and more extensively the Ste. Genevieve, over the 

northern part of the Mississippi Valley basin. Southern Illinois, where the Ste. 

Genevieve comprises the Fredonia limestone, Hosiclare sandstone, and Ohara 

limestone members, was the northern limit of continuous deposition. On the 

other hand, faunal relations with the faunas of the far West indicate marine connections, of which that established during the Ste. Genevieve was one of the most 

extensive. 

The closing epoch of the Mississippian in the typical province, the Mississippi 

Valley basin, was that of the Chester group. 
410 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Comparing the classification of the formations of the Appalachian Basin (east 

of the Cincinnati arch)-that is, those of the 'Vaverly group-with the divisions 

of the typical Mississippian, Weller accepts Stevenson's conclusion a that only the 

upper part of the Pocono is of Mississippian age and that this upper part is stratigraphically continuous with ,the Waverly. "The most definite point of faunal 

contact between this basin and the Mississippi Valley basin is found in the Max\-ille 

limestone, whose fauna is to be correlated essentially with the Ste. Genevieve of 

southern Illinois and Missouri." 

The Iowa section of the Mississippian as compiled hy Chamberlin and Salisbury 134c from the reports of the Iowa State Survey is as follows: 

Mississippian formations in Iowa. 

Formation. Thickness Characteristics. (feet). 

Unconformity. 100 Light ash-colored limestones and marls, with thin beds of sand- St. Louis limestone. stone. Good building stone. 

• 

Buff limestone and shales, underlain by coarse-grained encrinital 

Osage (Augusta) formation. 

I 

200-300 limestone; basal portion usually ferruginous; prominent chert 

beds. 

- -

I Kinderhook formation. I 150-200 Bluish or greenish clay shales, fine grained; buff, compact, more or less argillaceous limestones; sandstones. 

----- ---

Lime Creek formation. 80 Dark-colored argillaceous shales, highly fossiliferous, and locally 

calcareous. 

----

In northern and central Iowa, owing to the effects of elevation and erosion 

during the later part of the Mississippian epoch, the higher divisions of the series 

are unrepresented; they are restricted to the southern portion of the State and 

the Kinderhook alone extends across it?01 

On each side of Mississippi River between Burlington, Iowa, and southern 

Illinois occur the typical sections of the Mississippian. The deposits are chiefly 

limestone, but in both the lower and the upper portions occur shales and sandstones, which mark the advance and retreat of the Mississippian sea. The basal 

formations (Kinderhook group) are irregular in occurrence, varying lithologically 

and faunally, and there are unconformities by erosion, particularly at the base of 

the Kaskaskia. 490 ' 

492' 881 

In southwestern Missouri and northern Arkansas, on the southwestern shore 

of the Ozark land, the Mississippian formations are, according to Adams and 

Ulrich, sa as follows: 

a "The lower portion of the Pennsylvania Pocono * * * decreased rapidly in the southwestern part of the 

State [Virginia] until it disappeared or was merged into the Grainger [Devonian] shales of M. R. Campbell." Stevenson, J. J., The Lower Carboniferous of the Appalachian Basin: Bull. Geol. Soc. America, vol. 14, 1903, p. 35. 

"His [White's] Shenango shales, Shenango sandstone, and Meadville shales, down to and including the upper 

Meadville limestone, are undoubtedly Lower Carboniferous, while the underlying divisions-the lower part of the 

Meadville shales, the Sharpsville sandstones, the Orangeville shales, and the Oil Lake group-are evidently later 

Devonian." Idem, p. 40. 
MISSISSIPPIAN. 411 

Correlation table of the Paleozoic formations in northern Arkansas [in part]. ~---~- -----

A standa rd time scale of the Ohioan province. Mappable lithologic equivalents in northern Arkansas -------- ------

I 

I 

Pitkin limestone. 

oi ----- --- ------ ~-

:;! B irdsvill e. U) \Yedington sandstone. ol 

...: ~ 

I Tribune. 

----- - - U) Q) ol +" 

~ Fayetteville formation. U) 

Q) 

..c: 

0 

Cypress. 

---~ Batesville sandstone. 

Ste. Genevieve. 

I 

- -----~ ---

0 St. Louis. Moorefield shale (including Spring Creek limestone). 0 

s 

ol Spergen Hill. I ..., (\Vanting.) Q) ~--

:;::: Warsaw. I 

Keokuk. Cherty limestone. 

a) --~ 

--- toil 

ol Boone limestone. U) Gray subcrystalline limestone. 

0 Burlington. St. Joe limestone. 

I 

______________ [ ----~---------------

Kinderhook. I Noel shale. 

Adams 5 describes these formations as follows: 

The Noel shale [now called the Chattanooga shale] has been previously described by the 

Arkansas State Survey under the name of the "Eureka shale;" but this name is preoccupied 

by the Eureka quartzite of Nevada, and accordingly it has been renamed, from the town of 

Noel, in southeastern Missouri, where it has been studied and at which place it is typically 

exposed. It consists of a bed varying from a few feet, and in some cases a few inches, up to 

70 feet in thickness. Usually it averages from 15 to 30 feet. Its color is often black, although 

not infrequently it has a greenish and sometimes a yellowish appearance, according to the 

conditions of weathering or the amount of carbonaceous material contained in it. 

* * * * * * * * * T.he Noel shale is succeeded by the Boone formation, which appears to be conformable 

with it and represents merely a change in the character of sedimentation. Over a large area 

its basal member is an even-bedded limestone, free from chert and showing in a distinct ledge, 

sometimes shelly and thin bedded. It is known as the St. Joe limestone member. Its thickness in northern Arkansas varies from a few feet up to 50 feet. * * * 

The remaining portion of the Boone formation consists of beds of cherty limestone and 

beds of chert, which vary in their lateral and vertical extent in such a way that it has been 

impossible to divide this part of the formation into members which can be generally recognized. 

The thickness of the formation is about 325 feet. 

The limestones of the upper portion of the Boone formation are often coarsely crystalline 

and have usually a light-gray color. They contain numerous well-preserved fossils, but crinoid 

stems are perhaps the most conspicuous. 

Generally the upper portion of the formation is heavily bedded, and the lower portion 

contains a large amount of flint. The line separating the St. Joe member from the remaining 

portion, although not marked by any very evident stratigraphic break, has been drawn at the 

point where the chert appears and is at a definite horizon. 

In the vicinity of Batesville there is a bed of shale lying upon the Boone limestone and 

chert. It is well exposed around Moorefield, from which place it is named. In that locality 

it has a thickness of from 50 to 75 feet. To the west, at Marshall, it is not over 35 feet thick, 

and evidently it does not extend much farther westward. The shale has a light-grayish or 

bluish color, and is very friable. In places it is sandy. 

The Moorefield shale is succeeded at Batesville by sandstones with some interbedded 

shale. In certain localities to the west the formation contains interstratified limestones, which, 
412 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

where they are weathered, appear sandy. Where the Moorefield shale is absent this formation 

rests directly on the Boone formation and is usually found in this position between Marshall 

and Fayetteville. The thickness of the formation in the Yellville quadrangle is about 75 feet. 

The conspicuous portion of it is an even-bedded yellowish-brown sandstone. 

The conspicuous portion of the Fayetteville shale is a bed of black carbonaceous shale, 

which is usually thinly laminated. It frequently exhibits a jointed structure and upon disintegration falls into small fragments. Its thickness varies from about 50 feet up to 200 feet. 

It is named from exposures around Fayetteville, where it is conspicuous in the valley of the 

West Fork of White River. This formation rests upon the Batesville sandstone or, where 

that formation is absent, upon the Boone formation. The lower portion of the black shale in 

the Fayetteville formation contains lenses of dark-blue siliceous limestones at some places. 

Southeast of Fayetteville and westward to the State line the Fayetteville shale is succeeded 

by a sandstone formation varying in importance but usually having a thickness of between 50 

and 150 feet. It is thin bedded and heavy bedded and carries some interstratified shale. 

Succeeding the Fayetteville formation in the lead and zinc region there is nearly every-· 

where a bed of limestone. It is not always conspicuous, since it frequently occurs on slopes 

and is covered with debris of sandstones and shales from the higher formation. Its thickness 

where well developed is usually from 10 to 40 feet. In exceptional cases it is thicker. It 

sometimes has associated with it sandstone beds which contain the same fossils found in the 

limestone. The Pitkin limestone has been called the "Archimedes limestone" by the Arkansas 

Survey, because of the presence of this easily recognized bryozoan, the screwlike stems of 

which are seen in the weathered surface of the rock. In the northwestern part of the State, 

around Fayetteville, the limestone thins out to a pebbly stratum and disappears from the 

section. Along the north front of the Boston Mountains, however, it is a very persistent ledge, 

and the beds are frequently massive and give rise to an escarpment, a bench being developed 

on its upper surface. This formation is regarded as the highest one of the Mississippian series. 

It is probable that the thinning to the north and west is due to shore conditions, and its absence 

in some cases may be due to erosion previous to the deposition of the Pennsylvanian series 

which succeeds it. 

J-K 16. KENTUCKY AND INDIANA. 

Along the west side of the Cincinnati axis the Mississippian presents a section 

similar to that of the series along Mississippi River. At the base the strata lie 

conformably upon the Devonian and are somewhat sandy and shaly. The bulk 

of the deposit is limestone. The top part, which includes sandstone, is limited 

above by an unconformity. The local section for Indiana, as given by Blatchley 

and Ashley 86 and substantially quoted by Chamberlin and Salisbury/34b is as 

follows: 

Generalized section for Indiana. 

Formation. Thickness I Characteristics. (feet). 

Unconformity. 

Kaskaskia or Chester group ...... _____ .... ___ -_-- 120 Sandstone and limestone. 

.,: Mitchell limestone. ___________________________ 0-250 Massive impure limestones and calcareous ol shales. ·s.. 

.8-- Bedford oolitic limestone .... _ ... __ .. ___________ 20-80 Excellent building stone. 

"' Harrodsburg limestone ............ ______________ 60-90 Limestones and shales. -~ 00 Knobstone formation. _________________________ 40-600 Arenaceous shales and sandstones. Not in- "' 

~ eluded Ill Knobstone by Blatchley and 

Ashley. Rockford goniatite limestone ......... ___________ ···--------- Thin bed of limestone and calcareous shale. 

~- -- -----~--- ----- ---- - - .,: 

ol 

';:1 New Albany black shale ........... ___ .. ______ .. 70-120 0 

:> 

<ll 

~ 
MISSISSIPPIAN. 413 

The detailed stratigraphy of the foregoing section has been described by Hopkins and Siebenthal, 464 Ashley, 38 and Newsom, 615 and the faunal relations have been 

discussed by Kindle. 493 

The Mississippian of Kentucky has been classified by Ulrich 824 in a 

differing m several respects from any arrangement previously published. 

follows: 

manner 

It is as 

Formations in the Kentucky-Illinois fluorite district. 

Names of formations and members used in Synonyms and equivalent formations in 

this work. the Mississippi and lower Ohio valleys.a 

i ~. i Mansfield sandstone of Indiana. Coal en ·r ~ I ~· §§ I Mansfield sandstone. Measures conglomerate of western Ken- ~ .,.., .... tucky. <l) 0 bD il-< il-< I 

I 

Birdsville formation. Kaskaskia limestone of Hall. Chester 

Kaskaskia limestone of authors. Huron formation 

limestone. of recent Indiana reports is same as 

~ Tribune limestone. Birdsville formation. 

;:I 

0 

.... 

M 

I .... Aux Vases sandstone of Keyes. Probably 2 Cypress sandstone. en also Big Clifty sandstone of Norwood. "' 

>i ..J:i 

0 ·--

ol 

<l) "' Two upper members referred to as lower 

. t"rn 1 im""'"'· ui en ;:I Chester by Worthen and Engelmann. en 

<l) Stfi Genevieve Rosicla:e sa~~sto;ne. 2 ~ Entire formation referred to as St. Louis 

.E ~ mestone. Fredoma oolitic limestone. by Norwood. <l) ·s >i E-< 0 -~ {; p., 

ol .8-' ~ St. Louis limestone. St. Louis limestone of most authors, but not 0 

-~ "' ;:I of Engelmann, Shumard, and Swallow, "' 0 

-~ .... who do not include two lower formations 

::s M 

:.; Spergen in the St. Louis limestone. The two limestone. <l) upper formations equal, respectively, the s 

ol Mitchell limestone and the Bedford .... oolitic limestone of recent Indiana re- I <l) 

Warsaw formation, lacking. ::s ports. 

--

<l) • 

Mp., 

a! ;::I "'0 Keokuk limestone. >i 05l, Burlington limestone. Harrodsburg ol 

;., limestone 

';::: .-"1 Tullahoma formation . -- (typical) and "' 0 :> 0 Knobstone of ol {lg, Various formations of ~ <l) 0 the Kinderhook group. Indiana. 

]50 

~ 

M 

D 

~ 

;:I~ New Albany shale of Indiana reports. Chatevonian. s ;:I Ohio shale. tanooga shale. Grassy Creek shale of <l>2 Keyes . ..J:iM 

0 

a The matter in this column is generalized and incomplete. It will be given in greater detail in a work on the 

Paleozoic section in the Mississippi Valley soon to be published by the writer. 
414 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

J-K 17. OHIO AND EASTERN KENTUCKY. 

The Mississippian series on the east side of the Cincinnati arch consists chiefly 

of argillaceous and sandy deposits which are in contrast to the limestones of the 

west (Indiana) side. They have been described under the name Waverly since 1838 

(Briggs) and 1869 (Newberry), but with various classifications. Above these 

strata occurs a thin limestone which also belongs to the Mississippian and upon which 

the Pottsville (Pennsylvanian) was laid down unconformably. Prosser 645•

649 has 

recently reviewed the literature and sequence· of formations and his arrangement 

has been in general followed by Chamberlin and Salisbury 134a in the following table, 

but Prosser called the Logan exclusive of the Blackhand a formation, and not a 

group, _the old "Logan group" including both the Logan formation and the 

Blackhand. 

Generalized sect·ion for Ohio, a 

Formation, Thickness Characteristips, (feet), 

Unconformity, 

Maxvillt> limestone. ___________ 25± Fossiliferous limestone often brecciated. 

d Logan group .. __ . ___ ... 100-150 Sandstone, massive conglomerate and shale. -~ p, ,; Blackhand conglomer- 50-500 Sandstone and fine conglomerate, ,9< -~ ate. "' .... ,;!:! 0) Cuyahoga shale .... _._ .. 150-300 Light-colored argillaceous shales, with thin beds of sandstone. en en ,;!:! >. Shales characterized by ferruginous nodules. 

::;s >::· 0) Sunbury shale __________ 5-30 Black bituminous shale. :> Berea grit. .. _ .. , ___ ... _ 5-17.5 Sandstone, used for building stone and for grindstones; locally ; carries oil, gas, and brine, 

Bedford shale ........... 50-150 Thin-bedded shales; occasional thin beds of sandstone. 

6d :>cO Ohio shale ..... _._. __ .. ___ . ___ 300-2,600 Mainly black or dark-brown shale. ' 0>·,.., p 

~-~~------------------------------------------------ a Prosser, Jour. Geology, voL 11, 1903, pp. 520, 52L GeoL Survey Ohio, vols. 6, 7; BulL No, 7, 4th ser., 1905, 

The correlation of this section with that of the typical Mississippian section 

and the Appalachian equivalents on the east is discussed by Girty as follows: 361 

In 1900 an effort was made to trace eastward into Pennsylvania the members of Newlberry's Waverly section in northern Ohio. The Berea grit of the Waverly group was found 

to be the equivalent of the Cussewago sandstone of northwestern Pennsylvania. The Orangeville shale of that region is the basal third of the Cuyahoga shale, in part equivalent to Orton's 

Berea shale. The Sharpsville sandstone, representing the middle portion of the Cuyahoga, is 

probably the stratum producing the lower falls at the village of Cuyahoga Falls. The Meadville 

shale can with little doubt be correlated with the upper portion of the Cuyahoga, and it seems 

probable that the Shenango sandstone and shale are the equivalents of the Logan group. 

It is doubtful if the Corry sandstone is represented in Ohio, while the Bedford and Cleveland 

shales probably die out before reaching the Pennsylvania line. 

The relations of the Waverly to the clastic formations of Pennsylvania and 

West Virginia have been traced by Stevenson,794a who uses the term Logan in the 

sense given to it by Orton, rather than as restricted by Andrews and Prosser. 

"Logan" in the following quotation thus ~omprises the original Logan formation 

and the Blackhand formation. 
MISSISSIPPIAN. 415 

The Shenango sandstone has been followed by Dr. White into Trumbull County of Ohio, 

where it is about 15 feet thick and rests on 80 feet of Meadville shales. Prof. Orton regards the 

Logan sandstone of Ohio as the Shenango sandstone but includes also in the equivalence the 

overlying Shenango shales of White, which, as will appear in the second chapter, must be considered with the Mauch Chunk. 

The Logan, in Ohio, is double, sandstone above and conglomerate below, at the typical 

localities. Followed into Ohio from Pennsylvania the rock becomes finer, tho sandstone 

becoming shale and the conglomerate sandstone. In the counties of Knox, Holmes, Richland, 

and Coshocton the sandstone is represented by the Olive shales of M. C. Read, which are upward 

of 200 feet thick, but farther south the mass becomes a fawn-colored even-bedded fine-grained 

sandstone. The conglomerate gains in coarseness westward and southward, being a coarse 

rock in \V ayne, Holmes, Coshocton, Knox, Licking, Fairfield, Hocking, Vinton, and Ross 

counties, which, as Prof. Orton observes, mark "the northwestern arc of the sea boundary in 

Sub-Carboniferous time." The conglomerate is not always continuous, there being usually, as 

Prof. C. L. Herrick has shown, two beds of conglomerate separated by layers of fine sandstone 

or even of shale. The pebbles are usually fiat, small, and of practically uniform size. Southward 

from Ross County, along the western outcrop, the rock is less coarse and it ceases to be conglomerate before reaching the Ohio River, where it is the upper portion of the Kentucky Knobstone. 

The Logan rests upon the Cuyahoga shales of Orton, varying from 150 to 400 feet, with the 

Buena Vista sandstone at the base, a persistent bed, identified with the Sharpsville of White 

and continuous from the Pennsylvania line around the outcrop to the Ohio River at Buena 

Vista. Below this is the Berea shale, regarded as the equivalent of White's Orangeville, and at 

the base is the Berea grit, continuous from Lake Erie to the Ohio River, 50 to 75 feet thick, a 

fine sandstone at the north but somewhat argillaceous at the south. This ripple-marked 

sandstone is thought by Prof. Orton to be equivalent to the upper part of White's Oil Lake 

group. a This rests on the Bedford shales. Herrick has shown that the Logan does not extend 

so far northward as do the Cuyahoga shales. 

At this point may be inserted a table of approximate correlations worked out 

by Stevenson/94b between the Appalachian Basin and the Mississippian section of 

the Mississippi Valley: 

Lower Carboniferous: 

Logan, including Waverly shales ........... -- .. Ohio ..... -.. -...... ----------- Keokuk, BurShenango and Upper Meadville ................. Northwestern Pennsylvania ... ·1 

Upper 400 feet of Bedford and Huntingdon .. _ .Eastern Pennsylvania .. _ .. _____ lington, and 

Coal-bearing shales and sandstone. _____________ Virginia._______________________ Kinderhook. 

Upper plate of Big Injun ____________________ ._ .West Virginia. _______________ _ 

Upper Knobs tone of. _________________________ Kentucky .. _ .. _. _______________ Keokuk and 

Burlington. Protean of Safford ....... _______________ . ______ Tennessee._. __________________ } 

Lauderdale of McCalley _______________________ .Alabama. _____________________ Keokuk. 

Lowest Fort Payne of Hayes _____ ._ .. __________ Georgia and eastern Alabama ___ } . 

L t N f C b II T d V. . . Undetermmed. owes ewmano amp e ------------------ ennesseean 1rg1nm ....... . 

The Waverly group of Ohio has recently been traced across Ohio River into 

Kentucky and certain variations of stratigraphy have been described by Morse and 

Foerste/05 who recognize the formations distinguished in Ohio (Bedford, Berea, 

Sunbury, Cuyahoga, Blackhand, and Logan, in ascending order) but find that the 

strata below the Cuyahoga thin out toward the south and west and also lose such 

arenaceous partings as they had at the Ohio. The littoral formations of the Waverly 

a Orton, E., Ohio Survey Repts., vol. 7, 1893, pp. 28 et seq. 
416 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

gulf thus diminish southward toward the Mississippian sea. A typical section at 

Vanceburg, Ky., is stated by Morse and Foerste as follows: 

Section of Alum Rock, Vanceburg. 

Ft. ln. Feet. 

5. Cuyahoga formation ........................ _ ..... _._ .... __ ._. _____ ... ___________ 39 

Interval covered except a thick layer of argillaceous sandstone at the top. The 

sandstone contains Taonurus. Small phosphatic nodules are found in the 

basal part of the interval. 

4. Sunbury shale, total thickness .. ______ .. _____ .. ________ . _________ ._______________ 15! 

Blac)>: fissile carbonaceous shales, which can not be distinguished lithologically 

from the Ohio shale. 

3. Berea grit, total thickness---- ______ .......... __ ... __ ............. _ .. ____ .. ____ . _ 221 

Thick layer of gray sandstone .. ____ . ___ ... __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ __ _ __ __ __ __ _ 2 6 

Heavy layer of rather coarse grained gray sandstone, the upper surface excellently ripple marked .... _____ ... ___ .. __________________________________ .. 3 

Medium to thick bedded, rather coarse grained gray sandstones, beautifully 

ripple marked ...... -- .. -- .......................... __ .... _ ..... _. ___ ... _ 15 

Arenaceous shales ........... _ ............. _ .. ____ .. __ . _ . ___ . ___ . _ _ _ _ _ _ _ _ _ _ _ 1 

Layer of fairly coarse grained gray sandstone .. __________ .. __ ._. ___ .. _________ _ 

2. Bedford formation, total thickness ______ .. _ ... __ .. _ . _ .. ____ . _ . _ . _____ .. _________ _ 

Blue arenaceous shales and shaly sandstones; lower part slightly covered._. ____ 35 

Arenaceous shales with thin sandstone partings._._ ... __ ... _ ... ___ ._ _ _ _ _ _ _ _ _ _ _ 7 

Layer of thick-bedded gray sandstone ... __ .... _. __ .. __ . _________ . _________ ._ 1 

Arenaceous shales with two layers of sandstone_ ....... _ ... _ ... ___ . _________ . _ 6 

Heavy layer of gray sandstone, with lower surface contorted __ . ___ . _________ . _ 2 

Arenaceous shales with two layers of gray sandstone .. ______ .... _ ... ____ . __ .___ 6 

Layer of thick-bedded buff sandstone. __ ... _____ . __ .. _ ... _ ... _ ... ___________ 1 

Medium-bedded gray sandstones with shaly partings .. ______ . __ ._ ... _ . _ _ _ _ _ _ _ _ _ 2 

Arenaceous pink shales with sandstone partings ____ .. ______ . __ ...... __ . _ _ _ _ _ _ _ 2 

Covered interval ............................... _ .................. _ ... _ _ _ _ _ _ 5 

Layer of thick-bedded buff sandstone. __ ... __ .. ____ . ______ ....... _. ___ ._.___ 2 

Practically covered interval with some argillaceous shales. _ ... _ ... _ . _ . _ . _ . _ . _ 22 

1. Ohio shale. _ . _ .... _ ............................................... -......... -. 

Black fissile carbonaceous shales. About 10 feet from the top one or two linguloid shells occur. Near the central part the shales become softer and 

lighter in color and resemble a similar zone in the Ohio at Columbus (Ohio). 

The interval (242 feet) is mostly exposed and extends to the level of the 

Chesapeake & Ohio Railway. At "Slate Point," however, the top and 

bottom contacts are shown and the total thickness is 3011 feet. 

9 

8 

9 

4 

6 

9 

10 

6 

6 

95~ 

242 

At Petersville, Ky., southwest of Vanceburg, the Bedford and Berea are, 

according to Morse and Foerste, no longer separable and have together a thickness 

of 46~ feet only. Several successive sections are cited by them. At Irvine, Ky., 

southwest of Petersville, they measured the following: 

Section of Minerva Mountain, Irvine. 

6. Sub carboniferous limestone ......... __ ..... __ ......... __ . ________ . __ -- __ .... __ .. . 

Yellowish sandy-like limestone, lying at the extreme top of the hill. 

5. Upper Waverly series, not divided ............................ ----.-- ... __ ...... . 

Covered intervaL ............ _ ................. _ ........................... . 

Thin-bedded buff argillaceous sandstones, which weather to thin shaly pieces; 

Taonurus ........................ -- .. -- ... -... ---.---.-----.-------------

Layers of massive buff argillaceous sandstone, Taonurus abundant ........... . 

Buff argillaceous sandstones, weathering to shales;, Taonurus ................. . 

Covered intervaL ............................................. -.......... . 

4. Cuyahoga formation, top not determined ............................. -.......... . 

Brownish ferruginous and calcareous nodular layer of sandstone .. --. ____ ...... . 

Indurated bluish to pinkish argillaceous shales with ferruginous nodular layers. 

Soft bluish argillaceous shale with ferruginous nodular layers, slightly covered 

(top of Linietta clay) ............. ________ ............ -- ................. . 

Layer of brownish argillaceous sandstone, which breaks up into shaly layers .. . 

Soft bluish to pinkish argillaceous shales and small phosphatic nodules ....... . 

Ft. ln. Feet. 

1 

344 

60 6 

17 

24 

17 

225 6 

144 

6 

69 6 

63 6 

2 

8 6 
MISSISSIPPIAN. 417 

Ft. in. Feet. 

3. Sunbury shale, total thickness .................................................. . 3 

Black fissile carbonaceous shales. 

2. Bedford-Berea, total thickness .................................................. . 1z 

Argillaceous shales with phosphatic nodules ................................. . 2 

Black fissile carbonaceous shales ........................................... . 3 

Dark argillaceous shales, with some carbonaceous material ................... . 6 

Gray calcareous and argillaceous shales, slightly fossiliferous ................... . 2 

Yellowish calcareous and argillaceous shales, the upper part very fossiliferous .. . 5 

]., Ohio shale ................................................................... . 94! 

Black fissile carbonaceous shales, with an occasional softer argillaceous layer. 

Practically all exposed to the highway. 

In the Irvine section the Bedford and Berea are stated to be represented by 

1! feet of fossiliferous shale and the Sunbury by but 3 feet of black carbona~eous 

shale. Morse and Foerste conclude: 

The Bedford and Berea formations thin rapidly southwestward from the Ohio River and 

this horizon, even after it has been reduced to a thickness of only a few inches, can be traced to 

near the crossing of the Cincinnati geanticline by the Waverly series. 

The Sunbury shale, on the contrary, suffers but little decline, at least until Indian Fields is 

reached. 

The Ohio black shale of the Kentucky reports or the Chattanooga shale of United States 

reports, south of Petersville, is not of Devonian age alone but of Devonian and Carboniferousthat is, is composed of both the Ohio and Sunbury shales and a thin zone representing the 

Bedford and Berea. 

The sandstones which are extensively quarried about Rockville station belong to the 

Buena Vista member of the Cuyahoga formation rather than to the Berea grit. 

The Buena Vista sandstones begin to disappear from Olympian Springs southwestward 

except a single layer which, if not always the same, at least occupied the position of the lowest 

and which persists as far south as Stanton if not to Irvine. 

The Linietta clays belong to the lower part of the Cuyahoga formation. 

The so-called Waverly of at least the Richmond folio includes only the upper part of the 

Waverly, beginning with the base of the Cuyahoga. · 

J-K 17-18. PENNSYLVANIA, MARYLAND, WEST VIRGINIA, AND VIRGINIA. 

The area considered under the above heading covers that restricted part of the 

ancient bay of New York and Pennsylvania which was occupied by the sea at intervals during the Mississippian epoch and within which were laid down the coarse 

clastic sediments of the Pocono, at the base of the series, and subsequently the shaly, 

sandy Mauch Chunk formation. The Pocono is commonly a sandstone which 

includes also strata of conglomerate shale, and thin coal beds. Its thickness is 

1,800 feet in West Virginia and 2,000 feet in a section on the Susquehanna. It thins 

out to the north and south, to 500 feet in the Wyoming anthracite field, Pennsylvania, 

and to 100 feet or less in West Virginia. In western Pennsylvania, Ohio, Kentucky, 

and Tennessee its equivalents are shales and sandstones whose precise stratigraphic 

and faunal relations are still matters of doubt; but they, together with the Pocono, 

are referred in general terms to the position of the Kinderhook, Burlington, and 

Keokuk of the Mississippi River section.794 

The lower part of the Pocono is regarded as Devonian by Stevenson. 

The Mauch Chunk formation is dominantly a red sandy shale, which in Pennsylvania is chiefly a subaerial flood-plain deposit, according to Barrell.56 

48011°--12----27 
418 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

It attains a maximum thickness of 3,000 feet in the southern anthracite fields 

and thins away toward the north, west, and south, as shown by Barrell and Stevenson. 

In southern Pennsylvania, Maryland, and West Virginia the lower part of the shales 

gives way to the sandy Greenbrier limestone. Stevenson 794ct sums up the ·stratigraphic relations and nomenclature as follows: 

The Mauch Chunk is represented only by shales, or by shales and sandstones, along the 

northerly border in Pennsylvania, but southward limestone is found with shale above and below 

it. This limestone, in the Allegheny Mountain region, reaches to within 30 miles of the northern 

outcrop, while traces of it are present still farther north in the anthracite region. In southern 

Pennsylvania it is double, with a siliceous division below and a more or less argillaceous division 

above. The former is the more persistent at the north and in the central part of the basin, but 

'it is wanting in Ohio except in the extreme southeast. Both divisions persist in Virginia, 

Tennessee, and Alabama, as well as in the greater part of West Virginia and Kentucky. The 

lower shales become indefinite southward and the upper shales extend as shales little beyond 

the northern line of Tennessee. 

The whole series has been termed Mauch Chunk in Pennsylvania, and no special geographical 

term has been applied there to any of the subdivisions except in the northwestern part of the 

State, where Dr. I. C. White gave the name Shenango to the shale which there is the sole representative of the Mauch Chunk. In Maryland the upper shales have been termed Mauch Chunk 

and the limestone Greenbrier; in Virginia Prof. W. B. Rogers used the names Greenbrier shale 

and limestone; the United States geologists in that State have applied the names Canaan and 

Pennington to the shales, Greenbrier and Newman to the limestone; Prof. Safford in Tennessee 

divided the limestone into Mountain limestone above and the Siliceous group below, the latter 

into the Lithostrotion and the Protean, of which the former belongs to the Mauch Chunk; to 

Prof. Safford's divisions Mr. Hayes applies the designations Bangor and Fort Payne, with, in 

the southeastern areas, Floyd as equivalent to the lower portion of the Bangor; in Alabama 

the limestone is divided by Smith and McCalley into Bangor, Hartselle, and Tuscumbia; in 

Kentucky the divisions are Chester and St. Louis; and in Ohio Andrews termed it Maxville. 

Regarding the Mississippian of the Meadow Branch Mountains area of West 

Virginia, adjacent to the Potomac, Stose 803 points out that these rocks are structurally the southeasternmost occurrence of Carboniferous rocks in the northern 

Appalachians, outside of the anthracite region. They are widely separated from 

the main body of Mississippian sediments in western Maryland and Pennsylvania, 

and the formations which he maps have not been positively correlated with those 

of the broader area. These formations, which he regards as subdivisions of the 

Pocono group, comprise the Rockwell formation, Purslane sandstone, Hedges shale, 

Myers shale, and Pinkerton sandstone. . 

Stose describe'3 the Rockwell formation-the basal Carboniferous deposit-as 

composed of coarse arkosic sandstone, fine conglomerate, and buff shale, with some 

dark shale containing locally thin coal beds, and gives a section of this formation as 

seen at Sideling Hill, on the north bank of the Potomac, showing a thickness of 

541± feet. 

The Purslane sandstone he describes as the ridge-making rock of the Meadow 

Branch Mountains, Sideling Hill, Spring Gap Mountain, and the higher parts of 

Town Hill, and as composed largely of heavy-bedded coarse white sandstone with 

bands of quartz conglomerate and some soft white sandstones containing locally 

thin coal seams. Sections of the Purslane sandstone show that the thickness varies 

from 180 to 310 feet. 
MISSISSIPPIAN. 419 

The Hedges shale is described as a dark coal-bearing shale overlying the Purslane sandstone in the Meadow Branch syncline. Because of its soft and unresistant 

character it is exposed in but few places. The best estimate of its thickness, obtained 

from a section south of Devils Nose, is 170 feet. 

The Myers shale is distinguished by its bright-red color. The basal 60 feet is 

composed of cross-bedded reddish-gray gritty arkosic sandstone. At the top thin 

reddish-stained sandstone merges into the overlying Pinkerton sandstone. The 

thickness is estimated at 800 to 900 feet. 

The Pinkerton sandstone appears in only two small areas, one at Pinkerton 

Knob and the other in the northern part of Third Hill Mountain. At the base are 

gray platy sandstone and white quartz conglomerate, with soft crumbly sandstone 

above. The upper layers, however, are very massive cross-bedded coarse white 

sandstone. The thickness of the formation on Pinkerton Knob is given as about 

125 feet. 

Plant remains found in the Rockwell formation, the Purslane sandstone, and 

the Hedges shale are definitely referred by White to the Pocono group of the Carboniferous, 'and the few fragments from the Pinkerton sandstone are tentatively 

regarded by White as of the same age, certainly not younger than the Mississippian. 

No fossils were found in the Myers shale, but as it lies below the Pinkerton 

sandstone, it is older than that formation. 

Stose quotes from Stevenson, Ashburner, and I. C. White four sections of the 

Pocono and arranges them geographically from west to east, in comparison with a composite section in the Meadow Branch syncline in the Hancock quadrangle, as follows: 

Summarized sections of the Pocono group. 

--

Riddles- Shoups Juniata Sideling Meadow 

burg (I. C. Run (I. C. River Hill tunnel Branch 

White). \Vhite). (Steven- (Ash- Mountains 

son). burner). (Stose). 

Feet. Feet. Feet. Feet. Feet. 

Massive and flaggy sandstone and shale, some red._ 609 730 620 610 825 

Dark shale containing thin coal seams in massive 

and thin-bedded sandstone .................... _ 50 100 70 313 170 

Massive sandstone and conglomerate generally 

cross-bedded ........... _ ....................... 85 55 45 380 310 

Red to green or gray shale and flaggy sandstone .... 698 495 630 830 541 

1,442 1,380 1,365 2,133 1,846 

All the above sections show in general the following fourfold divisions; a lower group of 

shales and soft sandstones, generally reddish in color where weathered; a middle heavy sandstone and conglomerate, usually cross bedded; a variable thickness of black shale with thin 

coal seams and sandstone; and an upper series of shales, usually red, and thick sandstones. 

The thicknesses in the first three columns of the table correspond rather closely, the total thickness varying from 1,365 to 1,442 feet. The Sideling Hill tunnel section is much thicker, all the 

members except the top sharing in the increase. * * * 

It is concluded from the above comparison that all the Carboniferous strata now remaining 

in the Meadow Branch Mountains are Pocono in age and correspond to the rocks in the Broad 

Top coal field below the Mauch Chunk. * * * 

As pointed out by Stevenson, the thickening of the Pocono eastward is progressive. From 

300 feet in Laurel Ridge, Fayette County, the Pocono increases to 1,030 feet in the southeastern 
420 INDEX TO THE STRATIGRAPHY OE' NORTH AMERICA. 

part of Cambria County, to 1,400 feet in the western side of the Broad Top syncline, and to 

2,133 feet in Sideling Hill, Pa. If these measurements are correct, it apparently reaches its 

culmination in Sideling Hill and decreases eastward to 1,850 feet in the Meadow Branch Mountains. 

K-L 16-17. MICHIGAN. 

According to Lane 519a the Carboniferous of Michigan consists of the formations 

tabulated as follows: 

System. Series. 

Carboniferous formations of Michigan. 

Formation. Thickness 

(feet). Character of rock. 

-----~ -- --------1-----------1-----1--------------

Possibly later. 

Carboniferous. 

Conemaugh. \Voodville. 

Pennsylvanian 

0-110 Light-reddish sandstone and sandy 

shales. 

(Upper Potts- Saginaw. 

ville). 

White sandstone, coal seams, black and 

white shales; then bands of limestone 

400 and of siderite rare, rarely broken up 

and found in fragments of the sandstone. 

- ------------1------1-----------------

White sandstone and conglomerates, of 

0-170 small white quartz pebbles; brine and 

sulphates. 

Parma. ~-

-----1--:-1----

~ississippian. 

Bayport or Maxville. 

Upper Grand Ltapids. 

Upper St. Louis. 

Michigan. 

Lower Grand Rapids. 

Lower St. Louis. 

Osage or Augusta. 

50-235 

0-300 

Limestones, light and bluish, cherty; 

also calcareous sandstones. 

Dark or bluish limestones and dolomites 

with gypsum and blue or black shales; 

rarely reddish or greenish shales and 

dark or red sandstones. 

1--------~----1 I 

:'fapoleon. 

1

, ·white sandstone, often pyritic; brine or 

Upper Marshall. fresh water; sulphates low. 

1----------: ~----------------

260-560 

Lower Marshall. 

White and red sandstones, peanut con- glomerates, sandy shales, whetstones 

and blur shales, much carbonate of 

iron and mica in the formation; gen1 erally a red shale at the top and bottom. -------1---1----------

Coldwater. Blue shale, with nodules of carbonate of 

Buena Vista. 

Sunbury or Berea. 

800-1,000 iron, especially at the top; sandstone; 

very subordinate streaks of finegrained limestone, especially on the 

west side; black shales at the base. 

----- --------- -----------------------

Berea. White sandstone; brine and salt even near the surface. 

-------------- ----1---------------------

Devonian. Neo-Devonian. Bedford. 

Antrim (Senecan). 140+480 

Shale, mainly black and always at the 

base, with huge round balls of calcite; 

toward the top, blue and black shales. 
MISSISSIPPIAN. 421 

The formations are deeply covered by drift and are known chiefly by drill 

records. Lane comments on the sequence according to the sections drilled in many 

localities. 

The base of the Carboniferous in Michigan is usually drawn in practice at the 

top of the Antrim shale, bet·ween it and the overlying Berea sandstone, although it 

is theoretically drawn in the Antrim shale itself, so as to separate from it a portion 

equivalent to the Bedford shale of Ohio, regarded as the lowest Carboniferous of 

that State. Ulrich would draw the line below the Antrim, removing that formation 

entirely from the Devonian to the Carboniferous. ·where the Berea sandstone is 

not present the Antrim shale is succeeded by the Coldwater shale (Carboniferous) 

and a practical distinction is not possible. 

With reference to the line between Devonian and Carboniferous, G. H. Girty 

has prepared the following discussion a for this paper: 

In northwestern Pennsylvania I have discriminated a group of rocks between the Berea 

("Corry") sandstone and the top of the typical Chemung under the name "Bradfordian." In 

Ohio I am tentatively assigning to this group the Bedford shale, the Cleveland shale, and the 

Chagrin ("Erie") shale, or at least the upper portion of the Chagrin shale, from which our 

fossil faunas are obtained. Because the "Bradfordian" faunas were very different from the 

Waverly faunas (inclusive of the Berea sandstone but exclusive of the Bedford shale), I originally assigned the "Bradfordian" without hesitation to the Devonian. After comparing the 

"Bradfordian" faunas with the typical Chemung, however, I find that there exists a difference, 

almost equally marked, and feel somewhat doubtful whether the "Bradfordian" would not 

better be placed in the Carboniferous. 

In northern Ohio the most convenient horizon at which to draw the base of the Carboniferous 

would doubtless be immediately below the Berea sandstone. If the Bedford shale is included 

in the Carboniferous, so must also be the Cleveland. A more or less conspicuous change of 

fauna occurs in passing from the Chagrin into the Bedford. 

If the Berea sandstone is taken as the earliest formation of the Carboniferous in Ohio, then 

in Michigan the Devonian would naturally close with the top of the Antrim. If the Bedford 

and the Cleveland of Ohio are included in the Carboniferous, then probably a corresponding 

portion at the top of the Antrim would have to be taken out of the Devonian. If the entire 

"Bradfordian" is assigned to the Carboniferous (on the assumption that that term includes in 

Ohio the whole of the Chagrin shale), then more or possibly all of the Antrim would have to be 

placed in the Carboniferous. 

Regarding the Berea sandstone, Lane 519 b states: 

This is an Ohio formation and has never been seen at the surface in Michigan, but may be 

traced very well along the flanks of the Cincinnati anticlinal, from near Adrian north. Westward 

it seems soon to disappear and to be spotty in occurrence. Eastward it is persistent in Ohio, 

but thin, about 50 feet or less. ,. 

It continues to the northeast and north, as determined in wells at several points 

cited by Lane. 

Its thickness is usually about 100 feet and, as is well o-;hown in Huron County, it thickens 

gradually from about 40 feet until it is thickest near its western margin (over 200 feet), where 

it disappears suddenly * * *. It is generally fine grained, micaceous, a grindstone, and 

overlain by a black shale (the Berea or Sunbury shale). 

The Coldwater shale of Michigan directly overlies the Berea sandstone where 

that formation is present; elsewhere it succeeds the Antrim shale. The base of the 

a Notes, December, 1910. 
422 INDEX TO THE STRATIGRAPHY OF. NORTH AMERICA. 

Coldwater is the black shale which Lane refers to in the above quotation as the 

equivalent of the Sunbury. The Coldwater comprises further the representative 

of the Cuyahoga shale and possibly that of the Blackband formation. 519c Lane cites 

the following section from Huron County: 

Feet. 

Blue and sandy shales ....................................................... ______ .. _. _ _ 172 

Light House Point conglomerate ............ ___ . _ . _ . _ ....... _____ . _ ... _ .. _____ .... ____ .. _ . 4 

Blue shales with carbonate of iron, with Chonetes scitulus cf. pulchella common throughout... 720 

Black shale (Sunbury), with Lingula melie and Orbiculoidea newberryi in Ohio ......... __ .... 103 

1,000± 

The Coldwater shale thus represented and as originally defined covers the interval between the Berea sandstone below and the Marshall formation above. Among 

the subdivisions, the conglomerate in the above section is tentatively correlated by 

Lane with the Blackband of Ohio, and beneath it should come the representative of 

the Cuyahoga shale. Lane gives a number of well sections showing variations in 

color, composition, or thickness of the several subdivisions, and the strata have also 

been described by earlier writers. 

The Coldwater shale is succeeded by the Marshall formation, into which it 

passes by increasing sandiness without distinct plane of division. 

The Marshall formation as known in Huron County comprises, according to 

Lane, 5l9d the following beds: 

Feet. 

Napoleon (Upper Marshall) sandstone ................................................. _ ..... 300 

Lower Marshall (original Marshall): 

Hardwood Point shales and sandy flags, fossiliferous ("typical Marshall" fauna) ........ _... 85 

Port Austin sandstone .. -................................................................ 23 

Sandy shale ........................ _ . _ . _. _ ... ____ .. _ ......... _ ........... _ . . . . . . . . . . . . . 68 

Point aux Barques sandstone ..... _ ..... _._ .. ____ ....................... _._ ..... _ ...... _ 18 

Shales and flags with Romingerina julia ................ ......... _ ......... _ ....... __ ..... _ 41 

Grindstones with bands of peanut conglomerate and broken goniatite shells .. _. __ .... _. _... 25 

560 

Lane comments: 

The facies with the battered shells, chip pebbles (now coal), Solens, and lamellibranchs is 

a real shore facies. As we go toward the center of the basin the sandy facies of the Lower 

Marshall seems to disappear, especially the clear white sandstone, nor is the upper sandstone 

so thick. 

The Michigan formation, a sequence that carries brine and gypsum and is 

of smaller extent, succeeds the Marshall. Lane regards it as the deposit of an 

inclosed sea, like the Caspian. Its thickness is generally about 200 feet. At Mount 

Pleasant, where it is thickest, the section is as follows: 519r 

Feet. 

Shale. _ . _____ . _ ........... _ . _ ............................. _ ........... _ ......... _ . _ ..... _ _ 5 

Sandstone .............. _._. ___ ._._ .. __ ................... _._ ........... _ ....... ___ ._ ..... __ 20 

Dolomite and shale ........ _ .. _._._._._ ................. ___ ......... _ ......... __ ._ .... ___ ._. 75 

Anhydrite and dolomite ...... _._._. ____ .... _ ............... _ ........... _ ....... _____ ... _. __ 100 

Anhydrite ................ ___ ._._ ......... _ ... _._ ............. _._ ....... ____ .... _____ ..... __ 45 

Dolomite, shale, and anhydrite .. ____ . ___ ... _ ....... _._._ ......... _._ ....... _._ ..... ___ ._ ... 103 

Sandstone .................... _._._._. ___ ............... _ ......... _ ....... _. ___ ..... ___ ._... 8 

Shale ... _._ ......... _._._._._ ............... _._ ........... _._ ........ __ ..... _____ ... _. ___ . 5 

Sand~tone .................. _. _____ . _____ ......... _ ... ___ ....... _. __ ...... _. __ .... ____ ..... . 4 

Shale ... _._ .............. . 0- 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0- 0 0 0 0 0 0 0 0 0 0 0 0----- 15 

380 
MISSISSIPPIAN. 423 

The shales are dark or even black and the dolomites blue or dark and impure. 

The general association of dolomite and gypsum is like that in the Salina, but the 

deposits contain more clastic mud in proportion to the lime salts. 

According to Lane the deposition of the Michigan formation went on until "a 

depression to the west opened connection with the wide ocean at the time of the 

Maxville limestone of Ohio." Deposition appears to have gone on continuously 

with change to the formation of limestone. 

The Bayport (Maxville ~) limestone succeeds the Michigan formation, the two 

formations composing the Grand Rapids group. The Bayport is a hard lightcolored limestone with chert. It was deeply eroded before the deposition of the 

overlying Parma sandstone, of Pottsville age. The thickness remaining is usually 

only 50 to 75 feet, but in the well at Mount Pleasant Lane 519g recognizes as Maxville 

(Bayport): 

Feet. 

Shale and red limestone (weathered?) ..................................................... __ 30 

White limestone............................................................................ 30 

White sandstone, very salt water...... . . . . . .. . . . . .. .. . . . . . . .. . . . . .. . . . . .. . . . . . . .. . . . . .. .. .. . 120 

White limestone............................................................................ 55 

235 

The erosion of the Bayport limestone was general and at some points is complete. The formation is taken as the plane of division between the Mississippian 

and Pennsylvanian. 

L 20. NOVA SCOTIA AND ADJACENT NEW BRUNSWICK. 

For discussion of this area by Ells and Bailey see Chapter VIII, pages 384-386. 

M 20. BONAVENTURE COUNTY, QUEBEC. 

The'' Lower Carboniferous" (Mississippian) is represented by the Bonaventure 

conglomerate along the north shore of Chaleur Bay and the extremity of the Gaspe 

Peninsula. The Bonaventure, as described by Logan, 544v is a basal conglomerate, 

in places remarkably coarse, composed of pebbles, bowlders, and blocks derived 

from the underlying Silurian limestones and igneous rocks intrusive in them; all 

embedded in a red sandstone, which constitutes also an upper and more continuous 

member. Ells 307a distinguishes between the basal conglomerate and the upper red 

sandstone, more particularly on the south shore, near Restigouche Harbor, where 

the lower conglomerates are interstratified ''with gray beds containing Psilophyton 

and other Devonian fossils," and are unconformably overlain by the upper beds. 

The relations of the Bonaventure conglomerate in the eastern exposures of 

Gaspe Peninsula have recently been studied by Clarke, 157d who describes them as 

follows: 

Over the tops of the broken and decapitated folds of sand, limestone and conglomerate in 

Gaspe County lies a mantle of coarse clastic material, partly sand but chiefly jasper and limestone 

conglomerates. These strata do not appear north of Gaspe Bay and are chiefly confined to the 

mountains about Perce and to Bonaventure Island. Sandstones and conglomerates together 

may attain an elevation oi 1,500 feet represented by the Perce Mountain and they have a gentle 

and apparently uniform dip to the north, not often exceeding 10° and generally less. These constitute the Bonaventure formation of Logan and were regarded by him as of early Carbonic age. 
424 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

At places, as south of the Robin beach at Perce, the lower beds are fine feldspathic red, green1 

or gray sandstones, but even these carry pebbles, and the prevailing character of the formation 

is conglomeratic. South of this region under immediate consideration, sweeping along all 

the country on the north shore of Chaleurs Bay and into New Brunswick, these deposits are 

widespread. 

It is by no means easy, with present knowledge, to determine the true age of these deposits. 

In considering the commonly accepted view of Logan and his successors expressed above, we 

are confronted by phenomena at Perce and thence north to Point St. Peter, which seem to us to 

render this conclusion less secure than the observation of the more southerly outcrops would 

induce. Strata of conglomerates composed of pebbles carrying Siluric and Devonic fossils from 

the beds beneath and included by Logan in the Gaspe sandstone group, are found at various 

inclinations from Chien Blanc, on Gaspe Bay, all the way around Malbay to the Grande Coupe 

at Perce; at places these beds are nearly horizontal; from Cannes de Roche to Corner of the 

Beach, on the south shore of 1\falbay, they are nearly vertical and their color varies from red to 

ashen gray. In lithologic composition, the nature of the component pebbles, and in the general 

aspect of this northern series there is no distinction from that comprising Perce Mountain and 

Bonaventure Island. This latter, the typical expression and section of the Bonaventure conglomerates, stands with abrupt and sheer escarpments on the east and north, telling, like the 

Catskills, of a widespread further extension. The stratigraphic distinction between these higher 

Bonaventure conglomerates and the lower conglomerates of Malbay is only the apparent unconformity between the two. The gently sloping higher mass of Perce Mountain seems to lie 

directly on the vertical conglomerates of Canne de Roche, and it is the indication of this sharp 

unconformity that has been regarded as evidence of the distinction in age in the two parts of this 

great homogeneous mass of conglomerates. My examination of the sea wall from the Murailles 

at Perce to Corner of the Beach leads me to the impression that the erect conglomerates at the 

latter place, cut off as they are, to a narrow shore belt by the Siluric limestones behind, have been 

downthrown from their normal position along the zone of great disturbance which has involved 

the Murailles, Cape Barre, the sea floor outside the North Beach, and Perce Rock. No fact 

impresses the casual observer more forcibly than the apparent presence of extensive unconformity between these Bonaventure beds and the lower conglomerates, but the appearance is, I 

am confident, illusive and the Bonaventure conglomerates seem to represent a southern slightly 

undulated part of the same conglomerate mantle which appears more highly faulted in the 

anticlines farther north. Such an interruption involves several important conceptions. 

1. These conglomerates were certainly laid down unconformably on the vertical edges of 

the Devonic and Siluric strata about Perce. 

2. As the Gaspe sandstones of the Gaspe Basin have been folded up together with the 

Devonic limestones of the For;llon, either the Gaspe sandstones of the north are older than the 

entire series of conglomerates or the folding at the south, which involves the Devonic limestones 

and the Siluric strata together, was earlier than the upturning of the Devonic limestones at the 

north with which the older strata were not involved; or both conclusions are probable. 

3. While the sandstones constituting the lower part of the "Gaspe sandstone series" and 

their presence in the higher beds are indicative of barachois or lagoon conditions, the conglomerates themselves are clearly open coast deposits formed under such circumstances as prevail 

to-day wherever these very rocks are exposed to the play of the sea. 

4. That the Bonaventure conglomerates of this typical section, either in whole or in part, 

are of Carbonic age is probably only in a sense that their formation began in late Devonic time 

and continued without effectual interruption into that of the subsequent era, in the same sense 

perhaps as the upper beds of the Catskill group of New York seem to be of a post-Devonic age. 

These strata constitute the latest of the rock deposits in Gaspe. 
Color, dark gray. 

Symbol, 12. 

CHAPTER X. 

PENNSYLVANIAN. 

Distribution: Guatemala, central and eastern United States, New Brunswick, and Nova Scotia. 

Present though not distinguished from Mississippian throughout the Cordillera, the Arctic 

region, and Newfoundland. 

Content: "Coal Measures" (Pottsville to Monongahela inclusive) of eastern North America 

an•l their equivalents where distinguished; Carboniferous limestone of Guatemala. 

Mapped elsewhere with Carboniferous undivided. 

Pennsylvanian areas. 

D 15-1fi ............ Guatemala and Chiapas ...... . 

II 14 ..... _ ........ Central Texas ................ . 

I 14 ......... _. ___ .Northern Texas .............. . 

I 1()_ •••••••......• Alabama .................... . 

I-J 16, J-K 17-18 .. Appalachian coal field ....... . 

Page. 

425 

427 

428 

430 

430 

I -K 14-15 .. IV estern Interior coal region ......... . 

J-K 15-16 .. Eastern Interior coal region ......... . 

K 16 ....... Michigan ........... _._._ ........... . 

K 19 ....... Rhode Island and eastern Massac-husetts 

L 19-20 .... New Brunswick .................... . 

D 15-16. GUATEMALA AND CHIAPAS. 

Page. 

455 

466 

468 

469 

473 

The Carboniferous of Guatemala and Chiapas was recognized by geologists 

who preceded Sapper, but has been more accurately determined by him. He has 

described it in two works. 694'

695 From the later one we quote: 

In Alta V ora paz one may distinguish two series or formations-a lower, which consists of 

quartz, conglomerates, sandstones, clay slates, and graywacke, which has been called the Santa 

Rosa terrane by Dolfus and Mont-Serrat, and an upper series of limestones, dolomites, and 

conglomerates or breccias, which consists of both these rocks. These limestones and dolomites 

are both of very dark color and often strongly bituminous. Tho graphitic limestone occurs near 

Tucuru. 

In thA oldAr rocks of thA Santa Rosa terrane are quart"' conglomerates and puddingstones. 

They rest directly upon the Archean. In many places they contain pebbles of crystalline 

schists as large as nuts. The higher beds consist of sandstones, slate, shales, and graywackes 

which are sometimes interbedded and also show gradual transitions and even pass through 

coarse sandstones into conglomerates. The Santa Rosa strata also include limestones which 

contain crinoids and also Fusulina granum avenoe. [Sapper mentions local occurrences of 

gypsum, yellow shales and slates and clay slate, and other rocks.] 

Tho age of the Santa Rosa terrane is definitely fixed by the discovery of typical Carbon.:. 

iferous fossils which were determined by Stolley under the direction of Zittel. They are 

Syncladia biserialis Swallow, Lonsdaleiajloriformis Fleming, Fenestella sp., Nucula cf. ventricosa, 

Leda sp. n., Natica sp. [lower Pennsylvanian or possibly upper Mississippian-G. H. Girty]. 

The fossils have been found only in the upper horizons of the Santa Rosa and consequently 

the age of the lower horizons is not fixed. The thickness of the Santa Rosa in some places 

rises to as much as 200 or 300 meters but is very different in different localities. 

The upper terrane of the Carboniferous formations has a thickness of 600 to 800 meters 

and is shown by abundant fossils to belong to the upper Carboniferous [Pennsylvanian-Girty]. 

The fossils are Fusulina granum avenoe Roemer, Bellerophon cf. costatus Sow., Athyris ambigua, 

Athyris sublamellosa Hall, Productus semireticulatus Martin. In the vicinity of Senahu the rocks 

are chiefly dark-gray dolomites which readily decompose into a sand and show no traces of 

425 
FIGURE 12.-Sketch map showing the distribution of Pennsylvanian rocks that are separately represented on the 

geologic map of North America and the key to references in the text. 

426 
PENNSYLVANIAN. 427 

fossils. In the western part of Alta Vera paz these dolomites are, it is true, not entirely wanting, 

but limestones, limestone conglomerate, and breccia greatly predominate. The limestones rest 

conformably upon the Santa Rosa terrane. 

Complete lists of the Carboniferous fossils identified for Sapper by Stolley are 

given in nn earlier paper by Sapper. 697 

H 14. CENTRAL TEXAS. 

The follmving notes are selected from the forthcoming Llano-Burnet folio 

and from a bulletin 626 on the mineral resources of the region, both by Paige: 

The Carboniferous of the Llano-Burnet district is represented by limestone and shale 

formations of lower Pennsylvanian age. The limestone forms the lower portion of the system 

and has been mapped as the Marble Falls limestone. The shale, in which are included sandstone 

lentils, overlies the limestone and is mapped as the Smithwick shale. 

The Marble Falls limestone is separated from the underlying Ellenburger limestone (Cambrian and Ordovician), by a thin limestone conglomerate, though in one place a very coarse 

angular conglomerate or breccia was observed. There are some localities, however, where little 

or no discordance could be noted, as, for example, in the small basin 5 miles northeast of Blufton. 

The boundary at the top of the formation is sharp, and the Smithwick shale succeeds with 

perfect accordance in dip. 

The Marble Falls limestone is believed to be not more than 450 feet in thickness. It is 

composed of alternating beds of dark and light gray, dove-colored, and dark blue to black limestone. Many beds carry an abundance of cherty nodules, largely of a decidedly dark or black 

color. The color of this chert is diagnostic in distinguishing this formation from the underlying 

Ellenburger limestone, in which the chert is of a decidedly lighter color. The formation usually 

may also be distinguished by the petroliferous odor which it emits on being struck a sharp blow 

with a hammer. The Marble Falls limestone is confined largely to the southeast quarter of 

the Burnet quadrangle, but a small patch occurs northeast of Blufton and there are considerable areas in Riley Mountain. 

The two following sections will illustrate the lithology of the formation: 

Section of Marble Falls limestone in Riley Mountain, in stream 7t miles north of south edge and 

4 miles west of east edge of Llano quadrangle. 

Very hard, compact, nearly black limestone; some chert; nonfossiliferous. Feet. 

Thin, dark, very hard limestone; conchoidal fracture; weathers buff; platy and considerable 

black chert ...................... _ ...... _· ................................ _._............ 10 

Rather massive gray limestone; some black chert ..................................... _ ... _. _ 10 

Thin-bedded, very fine grained black slaty limestone........................................ 20 

Rather massive dove-colored limestone._ .... _ .......... _... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 

Thin-bedded slates or slaty limestone, black or dark gray; weathers yellow; apparently no 

fossils ............. _ ........ __ ....... _ . ___ .......... _ . _ ... _ .............. _ . _ .. _ . _ . . . . . . . 35 

Massive, coarse brown limestone ...... __ ... __ ... _____ ............... _ ..... _._ .. _. ___ .. _. __ . 5 

Thin-bedded limestone with cherts, gray-browns; marly in some places; weathers light yellowish; few fossils noted in talus slopes .. __ .......... _._ .. _ ..... _ ............ _._. _________ .... 50 

Crystalline grayish-brown limestone; some fossil fragments._ .. _ ..... _ ... __ ..... _. _______ .. _.. 12 

Massive brown limestone with large amount of chert.. ______ ....... _ .... _ ........ ___ . __ ._._... 7 

Coarse-grained brown limestone containing considerable light chert; weathers into a slope of 

talus ........... --- ................... _ ... _ ..... _ .. _._._ ............. _ ..... _. __ ... __ .. _.. 9 

Irregular limestone, gray to brown, fine grained, nonfossiliferous ...... _ ...... _ .... _. _. _ .. _ .. _. 32 

Thin-bedded, very dark fine-grained limestones with a large quantity of black chert; a few 

fossils. 

Irregularly bedded fine-grained brown and gray limestone; very fossiliferous at base; bituminous odor strong; some parts of base are mostly Productus remains ... __ ._ ... _ ...... _ ...... . 

Mostly thin-bedded fine to coarse grained brown and dark-gray limestone, highly fossiliferous .. 

Thin-bedded hackly limestone, brownish, sugary; bituminous odor ___ ._. ____ ............ _. ___ . 

Conglomeratic limestone containing pebbles of white chert and fine-grained light limestone. __ . 

Ellenburger limestone (Cambrian and Ordovician). 

22 

8 

6z 

2 

248 
428 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Section of Marble fi'alls limestone along north bank of Colorado River from dam to point above 

Smithwick shale. 

bridge at ~1farble Falls. Feet. 

Thin-bedded black limestone ............................ . 20 

Fine-grained dark-gray limestone ....................................................... . 15 

Thin-bedded and massive black limestone ................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 

Brownish-gray subvitreous to crystalline limestone............................................ 30 

Thin-bedded dark-gray or black fossiliferous limestone with Productus and crinoids............ 4 

Fine-grained crystalline gray limestone...................................................... 4 

Fine-grained gray limestone with mollusc.:an fossils............................................ 20 

Dense black or dark-gray limestone................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 

Light and dark gray mottled limestone with chert nodules.................................... 5 

Mottled gray limestones with crinoid stems 26 inches long.................................... .5 

Limestone conglomerate.................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 

Gray limestone without c.:hert................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 

Gray cherty limestone...................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

Black limestone with cherty layers........................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

Black, evenly bedded limestone with cherty layers....................................... 9 

Massive gray crystalline limestone.......................................................... 8 

Gray cherty limestone...................................................................... 25 

Gray crystalline limestone.............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 

Fault. 

Irregular-bedded gray limestone............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 

Black shaly limestone with chert layers and lenses............................................ 22 

Massive gray limestone; crinoid sterns........................................................ 60 

Fault. 

Dark cherty limestone..................................................................... 7 

Dove-colored fimestone with black bands and lenses.......................................... 40 

Conglomerate ............................................................................. . 20 

Ellenburger limestone (Cambrian and Ordovician). 368 

The Smithwick shale consists of a soft, very dark to nearly black carbonaceous shale in 

which are included a number of sandstone lentils. Because of its soft nature the formation 

was not observed in such attitude as would permit its measurement. .Moreover, its top is 

overlapped by Cretaceous sediments. Probably the beds exposed in Burnet County do not 

exceed 400 feet in thickness. The basal boundary of the formation is always sharp, the change 

to limestone occurring very abruptly. The formation represents tho youngest Paleozoic sedimentation in the region and the erosion surface, represented by its beveled beds, marks the 

great unconformity between Paleozoic and Cretaceous sedimentation. The formation is 

confined to the southeast portion of the Burnet quadrangle and to a small area in Riley Mountain, in the Llano quadrangle. 

I 14. NORTHERN TEXAS. 

Northern Texas is geologically almost completely separated from the areas to 

the north by the uplift of the Arbuckle Mountains. There is a possible connection 

around the west end of this uplift by "Red Beds" strata as yet unclassified. The 

stratigraphy of the Pennsylvanian of northern Texas was summed up by Taff 807 

as follows: 

The north Texas coal field extends from the south side of the Colorado River valley between 

Lampasas and Concho counties northward to Red River in Montague County. It is nearly 

250 miles in length, with an average width of about 45 miles, and has, therefore, an approximate area of 15,000 square miles. * * * 

The north Texas coal {icld is limited on the east by the Cretaceous rocks, which rest unconformably upon Coal ~feasures. At tho south end of the field tho Coal :Measures lie unconformably upon the :11ississ,ippian (Lower Carbonifmous) and are in part concealed by Cretaceous 

strata. Upon the west and northwest sides the Coal Measures arc bounded and succeeded 

stratigraphically by the Permian. * * * 
PENNSYLYANIAN. 429 

The Coal :Measures of north Texas were separated by Mr. Cummins a into five divisions 

or groups, as follows, in descending order: Albany, Cisco, Canyon, Strawn, Millsap. 

M~illsap division.-This group of strata has not been recognized south of northern Erath 

County, though, according to the structure of the rocks, it should occur in the basin of Leon 

River in Comanche County. According to the Texas Survey it thins southward and does 

not occur in the Colorado River valley. North of Trinity River valley in Wise County it is 

concealed by the overlap of Cretaceous rocks. The top of the formation includes coal bed 

No. 1, whose outcrop is located upon the map and which is mined at Thurber, Gordon, Rock 

·Creek, and Bridgeport. The strata of this group occur at the surface between the coal outcrop 

referred to above and the Cretaceous border. The base is not exposed, and much of the section, 

which has a thiekness of about 1,000 feet, is coneealed. The complete section was obtained 

by diamond drill, penetrating the strata at Thurber. 

It is composed of blue and black shale, interstratified with oeeasionallimestone and sandstone strata. 

The deep wells at Gordon and Thurber produce gas and salt, but no coals were encountered 

below coal No. 1. 

Strawn division.-This is composed of nineteen separate members of sandstone and shale, 

making an aggregate thiekness of 3,700 feet in the southern part of the field, where the members of the group rest uneonformably upon the massive shale and limestone of the Mississippian, 

and in many cases are uneonformable with regard to each other. 

In the northern part of the field the aggregate thickness deereases to 950 feet. Coal is 

not known to occur in this division. 

Canyon division.-This group is composed chiefly of limestone and shale, with loeal beds 

of sandstone and conglomerate. The thieker beds of limestone oceur near the base and in 

the upper part of the series. The limestones are generally thiek or massive and hard, making 

esearpments or outcropping in prominent ledges. In the northern part of the field the group 

eontains twelve separate members of limestone and shale and one eonglomerate, making an 

aggregate in all of 800 feet of strata. Unlike the Strawn, this division inereases in thickness 

northward. In the northern part of the field it contains 930 feet of strata. No coal is reported 

to oeeur in these rocks. 

Cisco division.-There are nineteen different members of this group, each of whieh is found 

to be variable in lithologie nature. Some of the members eontain limestone, shale, coal, and 

sandstone, and several contain eonglomerate, while a few are eomposed almost entirely of 

limestone and shale. Throughout the section there are not fewer than twenty separate beds 

of limestone, which arc usually thin. The shale as a whole is much thieker than all the other1 

strata together, and the whole group aggregates about 800 feet from end to end of the field. 

Several of the members which contain conglomerate rest upon eroded surfaces of lower 

beds and in some instances have been found to overlap and displaee beds of eoal. The heterogeneous nature of this group of strata indieates many repeated changes in sedimentation. 

Several thin beds of coal have been recognized near the top and in the lower middle part of 

the group, besides two beds of workable thiekness. These workable beds oeeur 200 and 300 

feet above the base of the division. 

Albany division.-The class of sediments making this group is generally a repetition of 

that found in the Canyon division. They are thiek beds of limestone generally separated by 

shaly members. 

Aceording to Mr. Cummins's report the Albany division thins northward from 1,180 feet 

at the south end of the field to zero on the Brazos River. 

It contains two shaly members which bear thin coal strata, none of which, however, have 

been found to cxeeed a few inches in thielmess. 

This group is succeeded by the Permian, which overlaps upon the Cisco division between 

Brazos and Red rivers. 

a Cummins, \V. F., Report on the geology of northwestern Texas: Second Ann. Rcpt. Texas Geol. Survey, 1890. 
430 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

According to Cummins, 199 later studies have shown that the beds to which 

the name ''Albany" formation was applied are the same as the Wichita formation, 

with which they are str~ttigraphica.lly continuous, the "Albany" being simply 

deposits in deeper water. 

I 16. ALABAMA. 

Plant remains, probably of Pennsylvanian age, are recorded by Smith 747 

from the metamorphosed rocks near Moseley (now Erin), Clay County, Ala., which 

have heretofore been regarded as a part of the Ocoee group of Safford. (See Chapter III, p. 88.) 

I-J 16, J-K 17-18. APPALACHIAN COAL FIELD. 

The following statement on the Appalachian coal field was prepared for this 

work in 1910 by David White: 

GENERAL FEATURES OF THE PENNSYLVANIAN IN THE APPALACHIAN PROVINCE. 

Conditions of deposition.-The Pennsylvanian (upper Carboniferous) rocks of the Appalachian trough or province l.ie unconformably upon a portion of the eroded and somewhat warped 

Mississippian surface. The initial invasion of the old basin by the Pennsylvanian sea formed 

a relatively narrow and elongated estuary extending from the southern anthracite field in 

Pennsylvania southwestward along or near the eastern margin of the central and southern 

Appalachian coal fields 898 to the Gulf region in southern Tennessee or northern Alabama, 

where, becoming confluent with the eastern interior lobe, it opened into the broader sea to 

the southwest. 

Later the ba·sin expanded both to the north and the west, broadening out in these directions 

to and beyond· the limits of the present coal fields. There was, therefore, encroachment of 

the sea on the land and overlapping of the terranes during at least the earlier divisions of 

Pennsylvanian time. Nearly everywhere the Pennsylvanian-Mississippian contact exhibits 

sharply contrasting sediments, though at a few points, such as the Bluestone section 123 in 

southwestern Virginia, there is an absence of conglomerates and a less abrupt change in the 

rock-forming material. Along the eastern portion of the basin the Pennsylvanian deposits 

lie on the Mauch Chunk formation (regarded as of Chester age); but farther northwest they 

are found resting bassetwise on rocks nearly if not quite as old as the Pocono. Farther along 

the western margin of the bituminous coal field they come into contact with the Cuyahoga 

shale, Logan formation, Blackhand formation, and Maxville limestone.39" Yet there is a 

remarkable absence of local topographic relief, the Mississippian floor having been apparently 

a base-level coastal plain over most of the area. 

Character of sediments.-The rock-forming materials are mainly terrigenous, brought down 

by rivers chiefly from eastward lands, which were probably the site of nearly continuous though 

variable epeirogenic action. Consequently the formations are in general thicker and more 

arenaceous toward the east side of the basin. The greatest thickening is toward the southeast, 

where at the edge of the Cretaceous overlap in Alabama the Pottsville, or lower division, 

probably exceeded 7,500 feet. Marine or brackish-water faunas, extending over wide areas, 

occur at numerous stages except in the later Pennsylvanian, thus showing frequent accessibility 

to marine life, though the conditions of sedimentation in the Appalachian trough were generally 

less favorable for open-water marine Mollusca than in the eastern interior arm. The subsidence 

kept, on the whole, relatively close pace with loading, so that, though the warping was unequal, 

there is slight evidence of the contemporaneous formation of new basins as the result of the 

orogenic changes. 

General structure.-In the western portion of the basin the beds lie nearly horizontal, but 

toward the eastern margin-that is, the eastern escarpment-of the bituminous regions, open 

folds with more marked anticlines were developed, from some of which the Pennsylvanian 
PENNSYLVANIAN. 431 

is largely or wholly eroded, and still farther east the folding was closer, with concomitant 

faulting, usually overthrusting, as in the anthracite and eastern Alabama regions. The folds 

dating from the great post-Paleozoic movement conform in system to those in the older rocks 

to the east and the principal faults are similarly northwestward overthrusts. The high elevation and consequent erosion of large areas of the closer folded basins, in the northern portion 

of the trough, resulted in the isolation of the anthracite and Broad Top fields in Pennsylvania 

and the Potomac and upper Cheat basins of Maryland and West Virginia. Similar detachments 

are seen in the southern Appalachian region. 

DIVISIONS OF THE PENNSYLVANIAN IN THE APPALACHIAN TROUGH. 

Pottsville group.-The Pennsylvanian of the Appalachian trough is, as a whole, divided 

into subdivisions which in practical application have the value of groups, although in the 

northwestern areas they are mapped as formations. Of these the Pottsville, or lower group, 

occupies the early narrow estuary, but the later divisions extend over the greater part of the 

Pennsylvanian overlap. The Pottsville, like the succeeding formations, is composed of sandstones, shales, and clays (including fire clays, coals, and limestones), but it contains a larger 

proportion of sandstones and arenaceous shales than the later formations. This is a natural 

result of the conditions of encroachment and rapid filling under which it was laid down. The 

Pottsville is thickest in the southern exposures, where, near the eastern outcrops, it probably 

exceeds 7,500 feet. In the northwestern bituminous area, partly as the result of less voluminous sediment, partly by reason of the absence of all but the latest members of the group, it 

measures locally less than 200 feet. The older divisions of the Pottsville-that is, those within 

the earlier limits of the Pennsylvanian sea-occur only (1) in the southern Appalachian area, 

(2) along the eastern border of the coal field in the central Appalachian region, and (3) in the 

southern and middle anthracite fields of Pennsylvania. 

Marine conditions, attested by the presence of marine Mollusca, were present at a number 

of stages in Pottsville time, particularly in the central and southern Appalachian regions, 

though limestone is extremely rare except in the upper Pottsville of the central Appalachian 

region, and in the Mercer shale member, in the upper part of the Pottsville in the northern 

bituminous areas. The Pottsville contains all the workable coals south of the KentuckyTennessee State line. Subdivisions of the Pottsville and their characters will be cited on a 

later page in connection with the discussion of the map units. 

Allegheny formation.-The Allegheny, next succeeding the Pottsville, is a thin formation 

characterized by a larger proportion of coal, shale, limestone, and iron ore. Like those of the 

Pottsville, its sediments are generally grayish or whitish, though they are more apt to be 

somewhat ferruginous. Red beds are absent except possibly in northeastern Kentucky. Its 

limestones, several in number, are distinctly marine, though relatively thin, and may be 

traced continuously over large areas. In the bituminous districts, where it is sometimes known 

as the "Lower Productive· Coal Measures" ("XIII"), the Allegheny ranges generally between 

250 and 350 feet in thickness near the northern outcrop, though it thins southwestward to 160 

feet in northeastern Kentucky. It is also greatly thinned in the bottom of the broad syncline 

of the main coal field. The Allegheny appears to have been completely eroded from the region 

south of the Kentucky-Tennessee line, but it is possible that the sandstones tipping the summits 

of several of the highest mountains in the coal field of northern Tennessee may represent its 

basal terranes. 

Conemaugh formation.-The Conemaugh, which succeeds the Allegheny, is generally 

marked at its base by sandstone or conglomerate. It is especially characterized by sandstones, 

shales, and limestones, intermingled, particularly in the western area, with red and green• 

shales, clays, and sandstones. It contains less coal than any of the other Pennsylvanian 

formations of the Appalachian trough, and in most of the earlier reports of the Pennsylvania 

and Virginia State surveys it was consequently known as the'' Lower Barren Measures'' (''XIV''). 

A thin 'limestone known as the Ames (or "Crinoidal ") limestone member, which occurs near 

the middle of the Conemaugh formation, is locally present over large portions of the field, and 
432 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

was formerly supposed to contain the last representatives of distinctly marine Mollusca 1n the 

Appalachian trough, but recent discoveries indicate marine conditions at a level somewhat 

higher. Not far from the horizon of the Ames member there have been found reptilian bones 

allied to early representatives of the group characteristic in general of the Permian. They 

may be regarded as forerunners of the Permian fauna. 

All sediments of Conemaugh or later age appear to have been removed from the portion 

of the Appalachian trough south of northeastern Kentucky, though the presence of the marine 

Mollusca implies continuity of these sediments clown the basin to connect with the open sea. 

Monongahela formation.-The Monongahela is distinguished by its relatively large proportion of coal and limestone, the latter composing over one-third of the sediments in some districts. 

The formation, as stratigraphically recognized in Pennsylvania, Ohio, western Maryland, and 

West Virginia, averages about 325 feet or less in thickness. Its coals, including the great 

Pittsburg coal at its base, are of notable thickness and value. As with the Conemaugh, 

red sediments become more prominent toward the south and its limestones, generally blue and 

in places containing "fresh-water" Mollusca, thin and disappear in the same direction. 

The Monongahela and the Conemaugh are not fully differentiated in the anthracite regions. 

Dunkard group.-The Dunkard group, which succeeds the Monongahela and which in 

lithologic characters and mineral content does not differ notably from that formation, is discussed in Chapter XI (pp. 492-494). The reference of its lower portion (below the vV ashington 

coal) to the Permian is not wholly beyond question. 

DETAILED DISCUSSION OF FORMATIONS. 

The composition and stratigraphy of the several formations of the Appalachian trough 

will now be considered. In order to give precedence to the series and regions more thoroughly 

known, the geographic order of treatment will be from north to south. Proceeding thus, we 

shall begin at the northwest border of the Pennsylvanian trough, encountering first the younger 

formations in the regions of late Pottsville overlap. Subsequently, working eastward and 

southward, we shall reach the thicker developments of the formations and the minor areas 

of the oldest formations lying along or near the earlier axis of the basin. 

OHIO AND PENNSYLVANIA. 

General jeatures.-~Iap sections K 17 and K 18 include the north end of the great bituminous coal :field in Ohio and Pennsylvania, several small isolated residual areas to the 

northeast, the Broad Top field, and the anthracite region. With the exception of the 

anthracite fields the coal measures of this strip are a unit not only in the classification applied 

but also as to essential continuity and parallelism of the strata. 

The great bituminous coal field of these States forms a part of a plateau correlated with 

the Cretaceous or later base-leveling and subsequent elevation. Toward the north and west 

the strata, rising more rapidly than the plateau surface, outcrop diagonally and are cut by 

erosion into an intricate fringe of irregular lobes, tongues, and isolated patches that it is 

impracticable to indicate on the map scale. The eastern border of the plateau coal field is 

defined by the stronger anticlines to which reference has already been made. 

The Broad Top coal field in Huntingdon, Fulton, and Bedford counties, in southern 

Pennsylvania, is a small remnant in a deep compound fold, in the region of close plication. 

In general the alteration of the coals increases toward the regions of greater thrust pressure; 

and so from ordinary domestic and gas fuels we pass through coking and steam coals to semibituminous coals at the eastern escarpment (Allegheny Front) of the great plateau field and 

in the Broad Top field. Small residual areas of semianthracite in vVyoming and Sullivan 

counties survive in other very shallow folds between the plateau and anthracite regions. 

The anthracite fields, three in number, in eastern Pennsylvania, consist of a group of 

residual troughs lying in northeast-southwest synclines. The structure is very complex, the 

strata being locally overturned, especially toward the southern edge of the region, while subordinate folds connect many of the synclines in varying degrees. 7950 
PENNSYLVANIAN. 433 

It will be seen that the eastwanl-increasing amplitude of the folds results in erosion of the 

Pennsylvanian from a number of the anticlines within the plateau region. The most prominent of these are known as the Deer Park, Laurel Hill, and Chestnut Ridge anticlines. The 

intervening folds have been described as First, Second, and Third bituminous basins, etc., or 

synonymously designated by geographic terms.a 

A radius from the border of the plateau coal field to the southwest cornerofPennsylvania 

spans a section extending from a point at or near the base of the upper Pottsville to the top 

of the Pennsylvanian as at present somewhat conventionally drawn. The middle and lower 

Pottsville are not encountered, as the entire upper Carboniferous area of Pennsylvania, outside of the anthracite fields, together with the whole of the Ohio Pennsylvanian, falls in the 

region of extension and overlap of the later Pottsville sea. The lower divisions are, however, 

present at the type locality, Pottsville, in the southern anthracite field. 

The terranes of the several sections throughout Ohio and Pennsylvania have received careful 

consideration and correlation by E. V. d'Invilliers 285b and J. J. Stevenson/95a who give full 

details or citations. The original data relating to the bituminous area will for the most part 

be found in the "Geology of Pennsylvania," by H. D. Rogers, 1858; in the county reports of 

the Second Geological Survey of Pennsylvania; in the reports of the Ohio Survey (especially 

volume 6 and Bulletin 9); in the following folios issued by the United States Geological Survey: 

Warren, Foxburg-Clarion, Beaver, Kittanning, Rural Valley, Elders Ridge, Indiana, Latrobe, 

Ebensburg, Johnstown, Amity, Sewickley, Brownsville-Connellsville, Rogersville, Waynesburg, 

Masontown-Uniontown, and Huntington; in United States Geological Survey Bulletins 65, 279, 

304, 318, and 349; and in the report of the Topographic and Geological Survey Commission of 

Pennsylvania for 1906-1908. 

Pottsville group.-The Pottsville group, earlier known as "Conglomerate series," "Pottsville conglomerate" ("XII"), and "New River series," forms the lowest division of the 

Pennsylvanian. As the basal and conglomeratic stage of the "Seral," the last of the ideal 

time divisions proposed by the brothers Rogers 674 for the Paleozoic in America, it was earlier 

called the "Seral conglomerate." It has sometimes been roughly correlated with the 1\fillstone grit of Great Britain, though on the paleobotanic evidence it appears that the upper 

Pottsville is to be correlated with the middle Coal :Measures of the United Kingdom. 

The Pottsville as a whole is the most natural of the Appalachian upper Carboniferous 

subdivisions, for it represents the first or main epoch of sea transgression in the cycle of 

Pennsylvanian sedimentation. In his characterization of the Pottsville I. C. White 905r points 

out the strong contrast which it presents to the red and greenish softer sediments below it, 

and to the softer, generally more argillaceous, terranes above it. 

"The series as a whole possesses a large amount of hard white or grayish sandstone, 

much of which is conglomeratic. The sandstones are harder, more compact, and siliceous; 

than any of the lower coal series above. Bowlders of this sandstone take a smooth polish 

when rolled along river beds, but this is not the case with most sandrocks above this." 

On account not only of the highly variable thickness of the different component terranes 

but also of the absence of one or more of them in different regions it is difficult to give a 

generalized section of much value. The following regional section in Mercer County, Pa., 

near the Ohio line, prepared by I. C. White, 904 is fairly typical of the upper Pottsville in Ohio, 

Maryland, and western Pennsylvania; and though of unusual thickness (301 feet) it is especially important on account of its location at or near the type localities for most of its members. 

The bracketed matter is added by the present writer. 

a For description of structure, anticlines, and basins, see Summary Final Rept. Second Geol. Survey Pennsylvania, vol. 3; Bull. U. S. Geol. Survey No. 65; Ohio Geol. Survey, Rept. V; West Virginia Geol. Survey, vols. 2 

and 2A; Maryland Geol. Survey, vol. 5, p. 260. For the anthracite regions see Second Geol. Survey Pennsylvania, mine maps in Atlas of anthraciteeregion, and Reports of progress A and AA; also Rogers, H. D., Geology of 

Pennsylvarria, 2 vols., 1858. 

48011°--12----28 
434 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Section in Mercer County, Pa. 

Feet. 

1. Homewood sandstone ["Tionesta," "Johnson Run," and "Piedmont"] .... _.............. 50 

2. Shales ....................................... _ ......... _ ...... _ .......... _. __ ......... 5 

3. Iron ore [in western Pennsylvania and across the southern Ohio line into northeastern Kentucky] ................... _ ....... __ ....... _ ........ _ ........ _ . . . . . . . . . . . . . . . . . . . . . . 2 

4. Mercer upper limestone [marine fossils] ......... _ ................... _ ................. __ 2! 

5. Mercer upper coal [place of Mount Savage coal and fire clays in Pennsylvania and Maryland]. 2! 

6. Shales [locally in northern Pennsylvania inclosing a "Middle Alton" coal]................ 25 

7. Iron ore [somewhat more persistent ·than No. 3, over much the same areas J-- ________ . . . . . . . 2 

8. Mercer lower limestone [marine Mollusca; more persistent than the Upper Mercer limestone 

but disappearing eastward] ________ ........ __ ............. ____ ........ _____ ... _ . __ .. . 2! 

9. Shales ............. _ ......................... _ ....... _ ........ _ ......... ____ . __ . _____ . 10 

10. Mercer lower coaL __________ ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2z 

11. Shales ______ ....... _ ........ ____ ............. _ ................. _ ...... _ .. ______ .. ___ . _ 10 

12. Iron ore ... _ .... : ..................................................... ________ . _ . . . . . . 1 

13. Shales ...................... __ ....................... _ ........ __ . . . . . . . . . . . . . . . . . . . . . . 5 

14. Connoquenessing upper sandstone ["Massillon" sandstone in part; present in nearly all 

sections] ............................................................... ___ ... __ . _ . . . . 40 

15. Shales with iron ore ____________ ............... ___ ..... ________ ....... ______ ....... __ ... 10 

16. Quakertown coal [generally recognized]-------------- ... _____ .. _ ..... ________ ._._ ... __ .. _ 2 

17. Shales [in places lacking] ______ ... ______________________ . __ . ________ . ____ . __ __ __ __ __ __ __ 40 

18. Connoquenessing lower sandstone [lacking in portions of the Allegheny Valley, locally along 

the Allegheny Front, and in some of the small northeastern residual areas; "~1assillon" 

sandstone in part]-------------- ................. ____ ................. _____ ._ .... __ ... 30 

19. Sharon iron shales [locally including a thin "Upper Sharon" coal] .. ____________ ... ___ . _ _ _ _ 30 

20. Sharon coal. ______________ ... __ .... __ .... __ . __ ....... __ . __ .... _ .. ___ . . . . . . . . . . . . . . . . . . . 4 

21. Fire clay and shales ____ . __ . __ ..... ____ . __ . __ .. ____ .... __ . __ .. __ .......... __ ... _ _ _ _ _ _ _ _ 5 

22. Sharon conglomerate [usually conglomerate, at least in part, and extremely variable in 

thickness or absent entirely; perhaps equals the Olean conglomerate of McKean and 

Warren counties, Pa.; usually lacking together with Nos. 19 to 21, where No. 18 is deficient].............................................................................. 20 

Contact with Mississippian. 

301 

The average thickness of this part of the Pottsville in the bituminous regions of K 17 and 

K 18 is less than 250 feet. As might be expected in a region of encroachment and overlap, 

the lower members are in places lacking. This lack is especially noticeable along portions of 

the northern border of the field in Ohio and Pennsylvania; but it is also evident locally in the 

interior regions, especially in the areas east of Allegheny River, in the Allegheny Front, and 

in the Broad Top field. It is not recognized beneath the deeper portions of the main basal 

syncline. 

The Homewood sandstone member, like the others, is highly variable, being in some places 

represented only by a few feet of shales. The limestones and coals are likewise subject to 

disappearance, the limestones being rarely represented near the eastern escarpment. The 

coals are all workable at one point or another. . 

For the upper Pottsville in the region under consideration, as described above, I. C. White 907a 

has recently revived Lesley's term Beaver River group, though excluding therefrom the Sharon 

conglomerate member, which was shown by Chance and D'Invilliers to be of Pennsylvanian age. 

Allegheny formation.-The Allegheny, as differentiated in 1875 a by Franklin Platt/37 is 

a formation whose limitation is largely dictated by convenience. It embraces the softer sediments of more quiescent waters intervening between the arenaceous invading Pottsville and 

the Mahoning and other sandstone and shale members of the overlying Conemaugh formation, 

or "Lower Barren Measures." It is remarkable for its good coals, on account of which it was 

for a time known as the "Lower Productive Measures," No. XIII of Lesley. As compared 

with the Pottsville the members of the Allegheny are relatively regular and continuous, and 

the occurrence in them of marine Mollusca is comparatively common. 

The principal members of the Allegheny formation, which in the bituminous regions does 

not usually exceed 300 feet in thickness, are as follows: ---------~--

a For other earlier and abandoned classifications see Stevenson, J. J., Bull. Geol. Soc. America, vol. 17, 1906, 

pp. 65-69. 
PENNSYIN ANIAN. 435 

l. Upper Freeport coal; persistent over most of the area of the formation and workable in many districts. 

2. Upper Freeport limestone member; thin but widely persistent with fossils reported as "fresh-water" in some 

areas, "marine" in others; accompanied, especially in portions of \Vestmoreland and Fayette counties, in western 

Pennsylvania, and in Jefferson and Muskingum countie~, Ohio, by the Bolivar clay member. 

3. Butler ("Upper Freeport") sandstone member; highly variable in thickness, or even lacking, being replaced 

by shales. 

4. Lower Freeport coal; widely persistent and locally very valuable. 

5. Lower Freeport limestone member; usually thin and more or less earthy, with fossils regarded as indicating 

fresh-water conditions; here and there associated with iron deposits. 

6. Freeport sandstone member ("Lower Freeport sandstone"); white and in places conglomeratic, usually 30 to 

50 feet or more in thickness; locally a sandy shale. 

7. Upper Kittanning coal (Cement coal); usually present, though variable, and of little importance except in the 

eastern portion of plateau; rarely recognized in Ohio; carries local cannel near Redbank Creek and in Beaver, Clearfield, and Indiana counties, Pa. 

8. Johnstown limestone member; 1 to 8 feet, magnesian limestone lying 2 to 5 feet beneath the preceding coal, 

but not found in the western tier of Pennsylvania counties or in Ohio. 

9. Middle Kittanning coal; important as the "Hocking Valley" coal of Ohio, where it is locally roofed by black 

shale with marine fossils; widespread, with rare cannel, in Pennsylvania, but unimportant except near the Ohio line. 

10. Lower Kittanning coal; very persistent, nearly everywhere; valuable, especially toward the Allegheny Front, 

also workable in parts of Ohio. 

ll. Lower Kittanning clay; valuable, 5 to 15 feet thick west of Allegheny River and passing through Ohio, where 

it touches the Vanport limestone member; locally, especially at the east, replaced by thick shales or sandstones. 

12. Kittanning sandstone member ("Lower Kittanning sandstone"); loc·al only, chiefly in Butler County, Pa., 

where it is massive and conglomeratic; 50 feet or more in thickness. 

13. Buhrstone iron ore; 6 inches to 20 feet thick, highly variable, usually cherty at base, underlain by Vanport 

limestone member; important in southern Ohio but less regular and persistent east of western counties of Pennsylvania. 

14. Vanport limestone member; familiar as the "Ferriferous limestone;" marine, with rich fauna; 903 unknown 

in the First and Second bituminous basins (east of the Chestnut Ridge anticline) in Pennsylvania; 5 to 20 feet thick 

in western counties north of Kiskiminitas River; locally present in Ohio, especially toward the south, where it is 

fairly persistent. 

15. Clarion coal; generally unimportant and less persistent; apparently lacking in considerable areas; a supposed split of this coal, the "Scrubgrass" or "Upper Clarion" coal, occurs about 10 to 15 feet higher and less than 

10 feet below the limestone in portions of western Pennsylvania and over much of Ohio. 

16. Clarion sandstone member; locally massive and thick, especially in southern Ohio, and fairly persistent, 

though usually insignificant. 

17. Brookville coal; very persistent; recognized in many deep borings beneath the Monongahela formation; 

usually separated only by its underclay from the Homewood sandstone member of the Pottsville formation; in portions 

of Ohio a thin marine limestone, known in the Ohio State reports as the Putnam Hill limestone, overlies a coal correlated 

by Orton 621 and Stevenson 7960 with the Brookville, but it is probable that both limestone and coal are of Mercer 

age (Pottsville). 39d 

Considering the large territory covered, the members of the Allegheny are more regular 

and persistent than those of either of the contiguous formations. I. C. White, 906 confirming 

the conclusions of the late Edward Orton, State geologist of Ohio, remarks that "all of 

the main strata in the Allegheny series of western Pennsylvania can be traced bodily 

across that State [Ohio] from where they enter it in Columbiana County to where they leave it 

to enter Kentucky from Lawrence County, 250 miles from the Ohio-Pennsylvania boundary. 

In this intervening distance some of the coal beds may change in thickness or disappear entirely 

over areas of considerable size, but they ultimately come into the section again, so that the 

integrity of the persistent beds of the Allegheny series in Pennsylvania is maintained entirely 

across the State, and this is true, not only of the coal beds, but also of the limestones. sandstones, fire clays, and even the iron ores, so that a section in Lawrence County is practically a 

duplicate of one in Columbiana." 

The Allegheny, which in northern Pennsylvania reaches a maximum thickness of a little 

over 300 feet and is in few places less than 250 feet, is thinner in the Broad Top field and thins 

to less than 250 feet in southwestern Ohio, while in the Kenova quadrangle, in northeastern 

Kentucky, it declines to about 170 feet. Several of its members are attenuated or lacking 

beneath the higher formations in the axis of the broad bituminous syncline. The local details 

given with great care in the Ohio and Pennsylvania county reports, cited in the general descrip-. 

tion (p. 431), are summarized in the final report of the Second Pennsylvania Geological 
436 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Survey, 285a and the identifications of the 

by I. C. vVhite 9056 and J. J. Stevenson. 796a 

of local coals are discussed by Ashley. 390 

considered by Stevenson. 796f 

members have been critically reviewed and revised 

The variation in the sections and the introduction 

The correlations in the Broad Top field are fully 

Oonema1tghjormation.-The Conemaugh as defined by Franklin Platt/37 in the Conemaugh 

River section of Pennsylvania, includes a series, generally less than 600 feet in thickness, lying 

between the Allegheny or "Lower Productive Coal Measures" ("XIII"), and the Monongahela, 

or "Upper Productive Coal Measures" ("XV"). On account of its relative deficiency in coals 

and economic limestones or iron ores it has been known as or included in the "Lower Barren 

Measures " also called "Elk River series" 905b and "No. XIV." 796b 

The numerous sections given in the Ohio and Pennsylvania reports, or cited by I. C. 

White 9050 and G. II. Ashley, 39 show a lack of regularity far exceeding that of the members of 

the Pottsville. Not only do the component terranes vary greatly in thickness but in many 

places they are absent; yet several of the individual members are of great persistence. The 

principal members of the Conemaugh formation which have been described from different 

areas 607 • 736 are, in descending order: 

l. Upper Pittsburg limestone member; just under Pittsburg coal; one to several thin, in places brecciated limestones, containing minute univalve mollusks in a variable interval averaging about 25 feet; in Fayette County, Pa., 

locally replaced by iron ores. 

2. Little Pittsburg coal; a widespread coal-bearing zone, rather than a single coal, 20 to 60 feet below the top of 

the formation; locally associated with two limestones, one ("Upper Pittsburg limestone") 3 to 5 feet thick, above, 

and the other (Lower Pittsburg limestone member) 8 to 10 feet thick, below the coal horizon. 

3. Connellsville sandstone member; massive, conglomeratic, about 20 feet or more in thickness, largely confined to 

the Connellsville region of Pennsylvania and the Potomac basin of Maryland and West Virginia. 

4. Little Clarksburg coal; 100 to 130 feet below the top of the formation; confined to southern Pennsylvania and 

northwestern West Virginia; directly underlain in latter region by the Clarksburg limestone member, which is impure, 

with ostracods and fish, and attains a local thickness of 20 to 30 feet. 

5·. Morgantown sandstone member; yellowish-gray mealy sandstone, 20 to 100 feet thick, locally conglomeratic or 

brecciated; 200 feet below top of Conemaugh at Morgantown, W.Va.; generally persistent in Pennsylvania, Maryland, and \Vest Virginia. 

6. Elk Lick coal; close under No. 5, widely persistent and usually present in Pennsylvania, Maryland, Ohio, and 

northern West Virginia, and locally workable to the east; surmounts the Elk Lick limestone member, 12 feet thick, 

in Somerset County, Pa. 

7. Ames (" Crinoidal") limestone member; very thin bed nearly midway in Conemaugh, generally 275 to 300 feet 

below top in most of Pennsylvania, 200 feet below on the Ohio at \Yellsburg, the interval decreasing westward to 140 

feet, though swelling to 300 feet at the southern outcrop in Ohio, 905d dark-bluish or greenish-gray tough siliceous granular 

limestone, usually 3 to 5 feet thick; present or represented by marine calcareous shell·bearing shales nearly everywhere 

except in northeastern portion of the Plateau region; a series of red clays, sandstones, and marls, the "Washington 

Reds," of variable thickness and color, lies above it; the limestone is rich in marine brachiopods and pelecypods; 

"its common fossils are Productus nebrascensis, P. pratteniamts, P. longispinus, P. semireticulatus, Hemipronites crassus, 

Spirijera camerata, S. plano-convexa, Athyris subtilita, Lophophyllum proliferum, Zeacrinus mucrospinus, together with 

undetermined plates and stems of crinoids.'' 

8. Harlem (''Friendsville" or "Crinoidal ") coal; thin and less persistent, immediately under Ames limestone 

member; present in most of outcrops in Ohio and western Pennsylvania, but rare near Allegheny Front. 

9. "Pittsburg Reds;" mainly soft or variegated shale and marly clays in thick variable series under No.8; less in 

evidence toward the northeastern and northwestern borders of the Conemaugh area; incloses a bluish fossiliferous 

limestone (the Ewing limestone of Ohio State reports) over much of the Ohio area. 

10. Saltsburg sandstone member; massive (20 to 60 feet); in places absent; probably same as Cow Run sand of 

southeastern Ohio; underlain by thin shale and local dark or gray limestone. 

11. Bakerstown coal; "Tyson" coal of Maryland, correlated by Stevenson with the Barton coal; fairly persistent 

in southern Pennsylvania but rarely identified in Ohio; locally important in Maryland and \Vest Virginia. 

12. Upper Cambridge ("Pine Creek") limestone member; typical in Noble County and southward in Ohio; thin 

and local in southwestern Pennsylvania. 

13. Anderson coal; unimportant; fairly persistent through Ohio and northern West Virginia but disappearing a 

short distance east of the Pennsylvania State line. 

14. Buffalo sandstone member; correlated with the Saltsburg by Stevenson; locally a conglomerate, 60 feet thick 

on Kiskiminitas River; generally persistent, 30 to 50 feet thick, though thinner on northern and eastern sides of basin; 

less important though locally coarse on west through Ohio. 

15. Lower Cambridge ("Brush Creek") limestone member; thin, black, fossiliferous, 30 to 60 feet below No. 13; 

generally present in Pennsylvania but disappears to west and south in Ohio. 
PENNSYLVANIAN. 437 

16. Brush Creek coal; Masontown coal in part; unusually persistent though generally unimportant in Broad ToP' 

field, through Pennsylvania, and largely in outcrops through Ohio; "Gallitzin" coal of the eastern side; multiple in 

division, with interbedded limestones.39h 

17. Mahoning limestone member; developed in eastern part of plateau field and locally associated with iron ore 

(Johnstown iron ore). 

18. Mahoning sandstone member. Includes: (a) Upper sandstone, in places massive and conglomeratic; said to 

be fairly persistent through much of Conemaugh exposure on east side of basin, but generally lacking on west; separated 

from lower sandstone of the Mahoning member by highly variable shale interval with coal. (b) Mahoning coal; locally 

present with clays in western Pennsylvania. (c) Lower sandstone; generally persistent through Conemaugh area, 

and in places conglomeratic though locally obscure or lacking; is here and there the basal member of the formation, 

resting directly on the Upper Freeport coal, the topmost member of the Allegheny formation. 

19. Uffington shale member; thin, local only, and crowded with marine invertebrates near Morgantown, W. Va. 

(Contact with Upper Freeport coal.) 

The Conemaugh formation occupies, naturally, a relatively small area. It reaches a 

thickness of over 700 feet near Monongahela River and in Maryland. Along the northerly 

outcrop it averages not over 600 feet, and to the west and south in Ohio it falls off to 300 feet 

or less. Coals in unusual number and thickness were developed in the Castleman basin, in 

southern Somerset County, Pa., and in Maryland. 

Broadly viewed, the Conemaugh is an arbitrarily limited and highly variable formation, 

largely sandstone or even conglomeratic in its lower portion, with much red and green clay 

material and marls in its middle, and more sandstones, locally conglomeratic, in the upper 

part, which was locally eroded before the deposition of the succeeding Monongahela formation. 

The last, so far as at present known, of the strictly marine invertebrate faunas occurs not 

far above the Ames limestone member (No. 7 of preceding list), perhaps the most widely 

extended of the distinctly marine members.a According to the fossil floras, the writer is 

inclined to draw the Westphalian-Stephanian boundary provisionally at or close above the 

top of the Allegheny formation, the Mahoning sandstone member being interpreted as showing 

the beginning of a more pronounced orogenic movement which seems gradually to have brought 

about the final exclusion of the sea. On the other hand, I. C. White, 907i citing (1) the discovery by Dr. P. E. Raymond, in the "Pittsburg Reds" (No.9 of list) at Pitcairn, Pa., of the 

reptilian genera Eryops, Desmatodon, and N aosaurus, closely allied to types regarded as 

Permian/30 (2) a fossil obtained near the horizon of the Ames limestone member near Salt Lick 

Bridge in Braxton County, W.Va., regarded as the tibia of a large reptile; (3) the Permian 

aspect, according to Scudder, of the insects from about the same horizon near Steubenville, 

Ohio; and (4) the introduction of red sediments,b argues for the reference of all the beds above 

the Buffalo sandstone member (No. 15) to the Permian. 'T'he evidence both of plants and of 

mollusks is distinctly contrary to this proposed correlation. The upper boundary of the 

Conemaugh is not yet drawn in the anthracite regions. 

Monongahela formation.-The Monongahela formation, or ''Upper Productive Coal Measures" 

(XV of Rogers), is the highest of the Pennsylvanian formations in the Appalachian trough. In 

K 17 and K 18 it occupies a small area in the bituminous regions, being for the most part confined 

to the deeper portion of the basin 2850 in southwestern Pennsylvania and eastern Ohio.c East 

of the Chestnut Ridge anticline in Westmoreland County, Pa., it appears only in very small 

residual areas in the Ligonier Valley and it is represented partly also in the Broad Top and 

Castleman basins. It is fully present in minor areas in the Potomac basin of Maryland and 

West Virginia. 

The Monongahela as defined by I. C. White 905 begins with the great Pittsburg coal and 

extends to the roof of the Waynesburg coal, comprising another somewhat arbitrarily differentiated division of the Pennsylvanian. The upper part of the Waynesburg coal contains 

Treniopteris, Equisetites, Baiera, and Saportrea, of Permian relations, while, as stated in the 

a At several points local deposits of red material occur as low as the top of the lower sandstone of the Mahoning 

member. 

bRed beds are stated by Dr. J. J. Stevenson 796" to be present in the upper part of the Allegheny in northeastern 

Kentucky. See also Phalen, W. C., Bull. U. S. Geol. Survey No. 349, 1908. 

c For areas of formations and individual coals see Geol. SurveY Ohio, Repts. V and VI, Bull. No.9, 4th ser. 
438 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

description of the Dunkard group in Chapter XI (pp. 492-494), the beds of the Dunkard above 

the Washington coal carry plants undoubtedly indicative of lower Permian age. I. C. White 907i 

regards the earlier Monongahela, together with the upper half of the Conemaugh, as representing the closing stage of the Permo-Carboniferous, connecting the latter with the base of the 

true Permian. No paleobotanic or invertebrate evidence justifying a reference of the Monongahela to the Permian has yet been found. It is regarded by the writer 4

a, 899' 897 as of Stephanian age. The black shales of the Monongahela contain fish fragments, largely unstudied, 

while the limestones present abundant Cyprian and Estherian types, generally regarded as of 

fresh-water origin. 

In the vicinity of Carnegie, Pa., a local unconformity occurs at the base of the formation, 

the topmost Conemaugh being eroded. 39a The formation, which is variable in character, contains much limestone and coal. The section at the Lambert shaft in Fayette County, Pa., was 

found by I. C. White 9070 to contain 44 feet of carbonaceous shale and coals and 202 feet of 

limestone, out of a total thickness of 388 feet for the entire series. There is relatively little red 

material in areas K 17 and K 18, though the limestones turn to shale and sandstone with great 

increase of red and green sediments in passing southward into J 17. The Monongahela· reaches 

its greatest thickness, over 400 feet, in central West Virginia, averages about 380 feet along 

Monongahela River in southwestern Pennsylvania, is 240 to 270 feet in the Maryland district, 

is incomplete in the Broad Top field, and thins to about 260 feet along the Ohio River boundary 

and to about 140 feet at its farthest northwest occurrence in Jefferson County, Ohio. Its 

composition in the type district is indicated by the following general section in Fayette and 

Westmoreland counties, Pa., compiled by J. J. Stevenson.793'

905a The annotations in brackets 

are taken chiefly from another paper by Stevenson.797 

Section of Monongahela formation in Fayette and Westmoreland counties, Pa. 

Feet. 

1. Waynesburg coal [fairly persistent in northern part of great bituminous field and on west, but 

locally absent in south and east; sometimes replaced by limestone breccia or iron)......... 6 

2. Sandy shale or sandstone [Browntown sandstone]; hard, gray, massive, in Harrison County, 

IV. Va ................................................................................ 20 

3. Little Waynesburg coal [thin, apparently confined to southwestern Pennsylvania and northern 

WestVirginia) ......................................................................... 2 

4. Waynesburg limestone [recognized generally in the Monongahela River valley of southwestern 

Pennsylvania and possibly in Broad Top field, but rarely in Ohio; usually over 8 feet thick, 

but fades entirely to the south in West Virginia] .......................................... 20 

5. Uniontown sandstone [coarse, gray, locally occupying interval in southwestern Pennsylvania, 

massive and conglomeratic in portions of the West Virginia area, shale in other regions). .... 50 

6. Uniontown coal [unusually persistent as coal or black shale, in Maryland, southwestern Pennsylvania, and West Virginia, even in deeper bore holes, though apparently patchy northward in Ohio; near type locality, Fayette County, it underlies a thin limestone with pelecypods)................................................................................. 3 

7. Uniontown limestone [generally persistent, 2 to 12 feet thick, in Pennsylvania and most of 

Ohio and West Virginia, though not noted in some drillings on west side of basin; 160 feet 

above Pittsburg coal in Salisbury basin (Somerset County, Pa.)] ........................... 12 

8. Sandstone [interval appears to change to "Tyler red beds" and "Ritchie red beds" of northwestern West Virginia] ........................................................ - - _ . _ . . . 30 

9. Great limestone [later designated Benwood limestone; thin along northern outcrop, lacking 

in portions of southwestern Pennsylvania; thickest (60 to 90 feet) in parts of Fayette and 

Westmoreland counties; replaced by shale and sandstone locally; patchy and broken by 

partings in northern part of Ohio area, fading to sandstone and shale to south in Ohio and 

West Virginia; includes Bulger and Dinsmore limestones) .................. -.......... _ ... 80 

10. Sewickley sandstone [local, though massive or even double) ............................ _ ... 30 

11. Sewickley coal [Meigs Creek of Ohio; important and widely persistent, about 100 feet above 

base of series, in Maryland, Pennsylvania, Ohio, and most of West Virginia)................ 3 

12. Fishpot limestone [same as "Sewickley" limestone of Stevenson; gray limestone, variable to 

30 feet in thickness; absent east and south of area in southwestern Pennsylvania, northern 

Ohio, and northern West Virginia, as well as from much of deep interior of basin; fades to 

shale and sandstone to south; has "fresh-water" shells) .................... -.- ........ _ .. 25 

13. Shale or shaly sandstone ...... ~ ............... -- .................................... -..... 20 
PENNSYLVANIAN. 

Feet. 

14. Redstone coal ["Pomeroy" coal of Ohio; very persistent, 50 to 70 feet below Sewickley coal; 

30 to 80 feet above base of series in Maryland and nearly everywhere throughout basin except 

around southwestern part of outcrop area, where not always recognized].................... 4 

15. Redstone limestone; apparently only in southern Pennsylvania and adjoining region of West 

Virginia and Ohio, 10 to 20 feet thick, with minute "fresh-water" fbssils; thins rapidly 

southward in West Virginia and Ohio .................................................... 10 

16. Pittsburg sandstone (sandstone or shale) [variable, coarse, in places pebbly, generally present 

about borders of the basin, though abruptly disappearing locally in shale and sandstone, 

the Redstone limestone (No. 15) being apt to vanish where the sandstone is well developed; 

in many localities lies directly on the Pittsburg coal (No. 17)] ............................. 40 

17. Pittsburgh coal [most important coal; very persistent and regular; correlated in Broad Top 

field, the Potomac basin of Maryland, through southern Pennsylvania, the northeastern 

counties in West Virginia, and the northern portion of the basin in Ohio, but becoming 

patchy, irregular, or absent around the southwestern part of the basin in Ohio a and West 

Virginia, and apparently absent in a portion of the south-central interior of the deep basin; 

yet fairly regular and workable over an area of 7,000-8,000 square miles] .................. 12 

ANTHRACITE REGION. 

439 

General f\'atures.-The position of the anthraeite fields and their general relations to the 

Appalaehian folding in eastern Pennsylvania have already been indieated (pp. 430-431). The 

Pennsylvanian synelines are relatively small, their eombined area being about 650 square miles, of 

whieh the area of workable eoal approximates but 484 square miles. 745a The anthraeite fields 

have been treated with great detail and thoroughness in an elaborate series of publieations 

for eaeh field, b as well as in several speeial reports,c published by the Seeond Geologieal Survey 

of the State. The whole has been admirably eondensed by A. D. W. Smith. 745 More reeently 

the general geologie relations and stratigraphy have been briefly diseussed by J. J. Stevenson;796h and the stratigraphie paleobotany of the southern anthraeite field has been treated in 

an advanee pu blieation giving eorrelations by the writer. 895 

In the anthraeite region the greatest thiekness of the PennsylVanian, 2,500 feet, is in the 

southern field; the seetions do not reaeh to horizons as high in the middle fields. In the 

northern field the deepest syneline eontains 1,800 feet of Pennsylvanian strata. 

The Pennsylvanian of the anthraeite regi~n is divided only into the Pottsville ("Seral 

conglomerate") and the "Coal Measures." The latter are grouped aecording to "white ash" 

or "red ash" eoals, but these divisions are loeal and highly variable. The paleontologic 

correlation of the post-Pottsville beds is ineomplete and without attempt to draw definite 

boundaries. 

The strata in the anthraeite region are in general mueh more arenaeeous than those of the 

bituminous series in any other part of the northern Appalaehian eoal field, the arenaeeous 

eharaeter being more and more predominant as the southeastern border of the region is 

approaehed. Conversely, limestone seems to be unknown exeept in the northern field. The 

series is moderately eoal bearing, there being as many as 25 eoals, 20 of whieh are of workable 

thickness, in the southern anthracite field, about 15 in the western middle field, and 16 in the 

northern anthracite field. In the eastern end of the southern anthracite field the Mammoth 

bed attains the remarkable thickness of 114 feet, of which 105 fee~ is coal. 

Pottsville group.-The Pottsville as a whole is most fully developed in the southern anthracite field. It was somewhat arbitrarily defined by the Lesley Survey as extending from the 

Buck Mountain coal bed, the lowest stratum of the "Coal Measures," to the top of the Mauch 

Chunk shale (Mississippian). In the type section, the Sharp Mountain gap at Pottsville, in 

which the "Twin" coal is regarded as equivalent to the Buck Mountain, the thickness as published by the writer 895 g is very nearly 1,200 feet, though the Broad Mountain section to the 

a See Bull. Geol. Survey Ohio, 4th ser., No.9, map; also Geol. Survey West Virginia, Rept. 2A, maps. 

b Atlas of the northern anthracite field, 6 pts.; eastern middle field, 3 pts.; western middle field, 3 pts.; southern 

anthracite field, 6 pts. 

c Repts. Progress A and AA, see also Ann. Repts. 1885, 1886, and 1887. 
440 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

northwest appears to be rather thicker. The group is overwhelmingly conglomeratic, the 

lower beds consisting of poorly assorted, locally subangular detrital material, which varies 

in size not only at different localities but at a single locality, 895a and is interstratified with some 

mud beds and coals. The higher conglomerates are more exclusively quartzitic, the pebbles 

less variable and generally better rounded, and the top portion of the column consists of a 

plexus of most massive, fairly regular, well-assorted quartzose conglomeratic material, in 

which occur several thin coals. The group is underlain at Pottsville by 400 feet or more of 

irregular, poorly assorted puddingstone conglomerates, locally unconformable on brownish-red 

and olive-green· muds1 which by some authors are included in the Pottsville and which no 

doubt belong to the Pennsylvanian. This transitional series, which technically .lies beneath 

the topmost stratum of red shale, the arbitrary lower boundary of the Pennsylvanian, quickly 

disappears in passing north. The lowermost Pennsylvanian in the southern portion of the 

anthracite regions (not deposited in the eastern middle and northern anthracite fields) bears 

some evidence of fluviatile deposition. The beds are, in general, unusually variable in thickness, and the stratigraphy of the coals shows a lack not only of parallelism but, to a certain 

extent, of synchronism. Consequently the correlation of the coals is far from complete or 

satisfactory. Little progress has been made in correlating the coals of the northern anthracite 

field with those of the basins to the south. 

The fossil plants of the Pottsville in the type region exhibit a rapid development and 

series of modifications which are of high stratigraphic value. With the exception of the species 

from the topmost beds, the ferns are, in general, readily distinguished specifically from those 

at the base of the "Lower Coal Measures,"a or Allegheny formation, as recognized in the 

northern United States, while the floras of the lower portions of the section are found, in 

passing downward, to bear still less resemblance to those of the "Lower Coal Measures." On 

the paleobotanic basis the type section is parted into four divisions, as follows: 

1. A lower division, 700 feet in thickness, called the "Lower Lykens division 895b because 

it includes (paleontologically) the lower group of Lykens coals (Nos. 4-6 and "0 ") as mined 

in the western portion of the field. This, the older Pottsville, includes two zones-(a) the 

Neuropteris pocahontas zone, including Lykens coals Nos. 5, 6, and "0," and contemporaneous 

with the Pocahontas formation (basal Pottsville) of the southwestern Virginia region 123, 124,

126 

(J 17), and (b) the Mariopteris pottsvillea zone, probably contemporaneous with the Quinnimont formation b of the central Appalachian region. Both are included in the time interval 

covered by the Lee formation, which to the south is represented, according to the fossil plants, 

by the Lookout sandstone and a part of the Walden sandstone in Tennessee and Alabama and 

which constitutes the lower Pottsville. 

2. Above the "Lower Lykens division" is a relatively barren series, about 130 feet in thickness, which the writer 8950 for temporary convenience called the "Lower Intermediate division." 

It contains a mixed flora and is regarded as lying at or near the horizon of the Raleigh sandstone, the topmost division of the lower Pottsville in the Virginian region, as will be explained 

farther on. 

3. A zone of about 200 feet, extending, roughly, from 370 to 570 feet below the top of the 

formation, contains the floras characteristic of Lykens coals Nos. 2 and 3, farther west, and has 

therefore been termed by the writer &95d the "Upper Lykens division." It is provisionally 

referred to the middle Pottsville, which embraces the Sewell formation, or New River group of 

I. C. White, 907a as recently proposed by him. The latter term, as restricted, is conducive to 

confusion, not only because of the economic development of the lower Pottsville coals along 

New River, but also on account of its former application to the Pocono coals (basal Mississippian), which are likewise commercially exploited along New River. 

a "Lower Coal Measures" as sometimes applied in the anthracite fields of Pennsylvania; not the series of that 

name in Canada or Europe. 

b See Raleigh, Pocahontas, Tazewell, Bristol, Estill ville, and Briceville folios, Geol. Atlas U. S. 
PENNSYLVANIAN. 441 

4. The upper portion of the section, extending down for about 370 feet, contains for the 

first 200 feet some mingling of "Coal Measures'' plants with species found in the "Upper Lykens 

division" of the Pottsville, and was therefore provisionally termed by the writer 895e the "Upper 

Intermediate division." This division, which includes Lykens coal No. 1, belongs to the upper 

Pottsville or Beaver River formation. a It will be recalled that this is the only part of the Pottsville found throughout the bituminous coal regions of K 17 and K 18, all of which falls within 

the region of later Pottsville overlap. In the Virginian region this upper Pottsville expands 

tremendously to the southeast, probably exceeding 1,500 feet in thickness and including the 

greater part, if not all, of the Kanawha formation in West Virginia. The paleobotanic data 

seem to indicate the Pottsville-Allegheny line of the bituminous fields at a coaly streak about 

100 feet below the conventional top of the Pottsville in the type section, the paleobotanic 

boundary being inclosed in the upper part of the great plexus of conglomerates. In the more 

northern anthracite areas the upper conglomerate has waned and the boundary as drawn on 

the sheets of the Geologic Atlas generally falls on or near a coal which, so far as determined 

paleontologically, belongs to the Brookville-Clarion coal group. 

From a thickness of over 1,400 feet in the Pottsville region of the southern anthracite 

field, the Pottsville, in passing to the north, thins to about 850 feet in the Mahanoy region, in 

the western middle field, about 400 feet in the Silver Creek basin, only a few miles to the north, 

in the eastern middle field; 300 feet in the vicinity of Hazleton, in the same field; and from 

about 250 to 163 feet, averaging about 225 feet, in the northern anthracite field. 745b• 795d In the 

western part of the western middle field the lower Pottsville b is partly represented, though 

the remaining coals have thinned. It is not recognized and is probably not present in the 

eastern middle field, where the upper part of the middle Pottsville is thought to have a thin 

representative. Only the upper Pottsville ("Upper Intermediate division") appears to be 

present, incomplete in some sections, in the northern anthracite field, where the lowest fossiliferous stratum, at points just above the Mississippian, is not older than the Sharon shale member of the bituminous districts. Pottsville coals, such as the Dunmore coal group (Mercer 

age in part), are few in the northern area though workable at a number of points (Boston mine, 

near Pittston, etc.), where they arc included in a lower "red-ash group." Only the upper 

Pottsville is present in the small residual areas in Wyoming and Sullivan counties. At Bernice 

it presents not over 125 feet, missing the lower portion of the Beaver River formation; at 

Mehoopany, the lowest bed, a conglomerate on the red shale, is perhaps not older than the lower 

sandstone of the Connoquenessing member. In other words, the basal portion of the Beaver 

River formation ("Upper Intermediate division" of the Pottsville type section) appears not 

to have been deposited in portions of the overlap area north of the anthracite fields, nor locally 

along the Allegheny Front or in certain other parts of the bituminous regions of K 17 and K 18. 

The subsidence and overlap of sediments is thus seen to have been most rapid and strongly 

marked in the anthracite regions. 

The axis of the lower Pottsville estuary doubtless extended southwestward across the 

eroded region to the south of the Broad Top field, which contains no Pennsylvanian older than 

the Beaver River formation or upper Pottsville. The early series is not seen again until, following the eastern edge of the coal field, we begin, in the Cheat Mountain region of central West 

Virginia, to pick up lower beds, as the present border of the Pennsylvanian gradually passes 

diagonally downward into the deeper portions of the smaller basin of the early deposition. 

Not till we reach the Pocahontas district do we meet beds as old as the lowest of the lower 

Pottsville in the type section of the southern anthracite field. The Pottsville expansions have 

been described and illustrated elsewhere by the writer.898b 

The "Goal .Measures" or post-Pottsville in the Pennsylvanian anthracite region.-The variability of intervals and the consequent difficulties of correlation of the individual members 

n See remarks on application of the name, pp. 433-434. 

b I. C. vVhite 907• has applied the name Pocahontas group to the lower part of the lower Pottsville. 
442 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

between the northern anthracite region and the regions to the south have already been mentioned. Between the southern and middle fields numerous correlations have been made by 

the State survey of the anthracite regions, as shown on the mine maps and in the "Summary 

final report." Others affecting in particular the northern field have been proposed by Stevenson/96; who inclines to the belief that the post-Pottsville beds also thin to the north and that 

the deep part of the northern anthracite field in the Wilkes-Barre and Nanticoke region may 

contain beds younger than the topmost in the southern anthracite field. Of this there is, 

however, little proof. The inclusion of the Mammoth coal bed in the Allegheny formation has 

been indicated by the writcr, 899 who is disposed to place the Allegheny-Conemaugh line as high 

as the Holmes coal bed in the southern areas, or as the Baltimore or Checker coal bed in the 

northern anthracite field. Harmonious with this is Stevenson's conclusion 796j that the marine 

fossils of the Mill Creek limestone of the Second Pennsylvania Survey reports, 688 feet above 

the Baltimore coal bed, are as old as Conemaugh and may be older. These fossils, as reported 

by Heilprin 432 and Girty,S65 comprise a distinctly marine invertebrate fauna, with Chonetes, 

Eumicrotis, etc. Three other thin limestones occur in the interval covering 320 feet below the 

limestone to which the name Mill Creek was applied by the Second Pennsylvania Survey, and a 

black shale with a marine fauna lies about 250 feet above that limestone. The occurrence 

of these marine limestones in the northern anthracite field is especially interesting, as is also the 

apparent absence, so far as yet reported, of typical marine faunas from any horizon in the 

southern field. The Oliphant coal bed, the supposed equivalent of the Hillman coal bed, would 

seem from the paleo botanic evidence to be older than the :Monongahela formation. 

In the southern anthracite field the higher coals have furnished plants regarded by the 

writer as of Monongahela age, but no beds of Permian age have yet been recognized in the 

anthracite regions. 

CENTRAL APPALACHIAN REGION. 

Generalfeatures.-To the south, in the next section of the Appalachian trough, the Pennsylvanian strip in J 17 and the southeast corner of J 16 becomes narrow gradually in West 

Virginia and rapidly in eastern Kentucky. We have here only the southward continuation of 

the great plateau (bituminous) field, which merges into the Cumberland Plateau. Except for 

the Frostburg-Potomac and Cheat Mountain basins, which are isolated along the eastern margin 

of the coal field, the separating anticlines being eroded, the eastern margin of the Pennsylvanian 

is fairly parallel to the general direction of the Appalachian folding. For portions of its extent 

the boundary is an overthrust fault, as, for example, St. Paul, Va., where the Cambrian is thrust 

on the Pottsville. Other important overthrusts which have caused the exposure of older beds 

in the interior of the field are those along Pine Mountain, in eastern Kentucky and Tennessee, 

and the Sequatchie Valley, in eastern Tennessee. Aside from the folds mentioned above or 

in the previous section the Pennsylvanian of J 17 and J 16 is relatively horizontal. 

The higher formations of the Pennsylvanian continue southward from K 17 and K 18 in 

greatly reduced area and markedly changed character, though the general sequence of the 

members is essentially the same. The principal changes pertain to composition of the beds as 

well as to thickness. 

Monongahela formation.-The Monongahela territory practically falls within a scalene 

triangle whose southeast and west sides roughly conform to lines drawn from Cumberland, 

Md., and Cambridge, Ohio, to Big Sandy River in Lawrence County, Ky. In Maryland the 

formation measures 240 to 270 feet; 572 it is considerably thinner on its western outcrop in 

Ohio and it reaches its greatest thickness-400 feet-in north-central West Virginia. It is 

thin in the deeper portion of the broad syncline, farthest from the old shore lines. It is notable 

that the limestones, which form so large a part of the formation in southwestern Pennsylvania, 

disappear soon after entering West Virginia, being replaced by red and green shales and sandstones. The Sewickley coal enters farther into the basin than the Pittsburg, but the Uniontown 

is the only one which appears to traverse the entire deeper part of the basin. 797a 
PENNSYLYA.NIAN. 443 

Conemaugh formation.-The Conemaugh formation has naturally a much larger area than 

the Monongahela and extends closer to the anticlines near the West Virginia and Maryland line. 

From a thickness of 700 to 800 feet in southwestern Pennsylvania it thins to the northern and 

western outcrops (about 300 feet in Ohio), but on the east, in one of the sections of western 

Maryland, it exceeds 625 feet. In the Piedmont folio 228 the equivalent of that part of the 

Conemaugh above the Bakerstown coal is mapped as the Fairfax formation and the equivalent 

of the lower Conemaugh is included in the Bayard formation. Toward the southwest the 

Conemaugh thins again, so that the formation is limited to a very narrow strip, hardly more 

than a county in width, on entering Kentucky, where it measures about 5fi0 feet, and, though 

its distribution is not fully worked out, it probably does not extend southwest of Morgan County, 

Ky. The fossil floras of the formations show that neither the Monongahela nor the Conemaugh 

is now represented in all that portion of the Appalachian trough lying to the south of this 

district. Like the Monongahela, the Conemaugh is notable for the diminution of the calcareous 

matter toward the south; the reel sediments increase in passing diagonally downward through 

the formation, which also becomes more conglomeratic toward its eastern outcrop. 

Allegheny formation.-The lower limit of the Conemaugh along its southern outcrop has 

recently been so radically changed as the result of a revolution in the classification of the older 

Pennsylvanian in the southern region that only in the latest contributions by Stevenson 796g and 

I. C. White 907 is it even approximately located. 

The Allegheny formation, which in K 17 and K 18 approaches so near the margin of the 

Pennsylvanian as to be nearly everywhere indistinguishable on small-scale maps, except in the 

southern and western middle anthracite fields, keeps the same relative position along the western 

outcrop for some distance beyond Ohio River; but on the east side it retreats westward as the 

thicker and successively lower Pottsville strata are developed along the Pennsylvanian outcrop; 

so that at the Kentucky line its connected areas are confined to a short belt lying in the western 

half of the field, though isolated patches cap the high ridges and tallest mountain tops far to 

the east. 

The formation measures 260 to 350 feet in western Maryland, 572 where that portion below the 

Middle Kittanning coal is described by Darton and Taff 228 as the Savage formation, the upper 

part being included in the Bayard formation. Deep-well records show it to be much thinner 

beneath the Monongahela area, though it approaches 300 feet in thickness at some places on 

its western outcrop in Ohio. Toward the south, however, it thins remarkably, so that in the 

Kenova quadrangle, in northeastern Kentucky, it falls under 170 feet, though several of its 

limestones are there present. Remarkably enough, in consonance with the downward diagonal 

trend of the red material noted in the overlying formations, we find records 635a, mct of red shales 

in the upper part of the Allegheny at several points on the southeastern and southwestern 

borders of the basin. This feature is, however, attributed by I. C. White 907 i to weathering. 

Formerly it was supposed that the Allegheny formation was very much thickened to the 

southeast and included what had been described 127 as the Kanawha formation, which attains a 

thickness of over 1,200 feet in southern West Virginia. A later review of the stratigraphy by 

Stevenson 795• 796a more than confirmed the very conservative changes first proposed by the 

writer 896 after the study of the fossil plants. Subsequent conclusions reached as the paleobotanic studies progressed have been met by the results of the stratigraphic work of the State 

Survey, so that the classification given by I. C. White in a recent report of the West Virginia 

Geological Survey is in nearly all important points in agreement with the preliminary correlations drawn by the present writer. The Stockton coal, the topmost coal of the Kanawha 

formation, which was previously 906a placed in the Upper Freeport position and regarded as the 

topmost bed of the Allegheny, is now put at a horizon beneath that of the Homewood sandstone member, being regarded as representing an Upper Mercer horizon. Similarly the "Roaring Creek" sandstone member, so well developed in the Tygart Valley and in the Buckhannon 

quadrangle, though formerly regarded as "Upper Freeport," is now placed by Stevenson and 

I. C. White at the level of the Homewood sandstone, the top member of the Pottsville, a corre-
444 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

lation in which the writer concurs. It is thus seen that the entire series which in the earlier 

literature on the Kanawha region of vVest Virginia was described as constituting the Allegheny, 

is now recognized as belonging to the upper Pottsville,a together with a part, at least, of the 

sandstone which in that region was formerly supposed to be the Mahoning. The cautions as to 

the literature descriptive of the Allegheny in the southern region apply equally to that of the 

Pottsville, as the terranes taken from the Allegheny have been added to the Pottsville, which 

has accordingly been newly grouped. 

The falsity of the former classification was discovered on paleobotanic evidence when the 

first of the quadrangles in central and southern West Virginia were mapped in detail; but the 

isolation of the quadrangles mapped and the very early stage of the paleobotanic studies made it 

impracticable at that time fully and definitely to correct the errors, hence a local nomenclature 

was introduced pending the time when the boundaries of the divisions composing the standard 

classification as used in the northern region should be definitely determined. In the Buckhannon quadrangle, 810 one of the first of these and one involving great changes in the thickness 

and delimitations of formations, the Pennsylvanian was mapped, largely on lithologic grounds, 

as follows: Braxton formation, 700 + feet [including all the strata above the conglomerate 175 

feet above the base of the Allegheny]; Upshur sandstone, 350 to 500 feet [representing the Allegheny and the "Roaring Creek" sandstone (equivalent to the Homewood member of the Pottsville)]; Pugh formation, 300 to 450 feet [representing all of the upper Pottsville between the 

Homewood member and the lower group of conglomerates]; and Pickens sandstone, 400 to 500 

feet [the lower group of conglomerates, with included coals, of the section which probably 

extends at the south into the top of the lower Pottsville]. 

Owing to the lack of paleontologic as well as of local stratigraphic data, the areal extent 

of the Allegheny to the southwest is not known. The Vanport limestone member, however, is 

stated by Stevenson 795r to be present in the northwest corner of Breathitt County, Ky. It is 

probable that the formation is represented only by small isolated patches on the highest lands 

toward the west side of the basin, and, possibly, on some of the highest summits in the eastern 

synclines, for although no paleontologic data showing the presence of the Allegheny are known 

south of Breathitt County, the fossil plants found in the Harlan sandstone of southwestern 

Virginia (Estill ville quadrangle), the Bryson formation of the Cumberland basin in eastern 

Kentucky, and the Anderson sandstone in the high mountains of Campbell and Anderson 

counties, northern Tennessee, are said to represent stages so high in the Pottsville as, perhaps, 

to justify the inference that the upper parts of these formations are of Allegheny age. This 

will be more fully noted in the discussion of the Pottsville. 

No Paleozoic rocks of Allegheny or later age now remain in the Appalachian trough south 

of northern Tennessee. The evidence of fossil plants shows that all the terrane3 exposed south 

of the Briceville quadrangle are of Pottsville age. 

Pottsville group.-In K 17 and K 18 the beds of the Pottsville include only the overlapping 

upper Pottsville, or Beaver River formation, except in the anthracite regions, where in passing 

from the northern anthracite field into the southern anthracite field the older and deeper Pottsville of the early Pottsville estuary are encountered. The upper Pottsville marks the later great 

invasion of the Pottsville sea. 898a Other invasions occurred in both early and middle Pottsville 

time. The region north of a line drawn from Keyser, W. Va., to Ironton, Ohio, lies wholly 

within this area of upper Pottsville encroachment, which, in fact, extends somewhat irregularly 

for some distance to the east of that line. It is interesting to note that before the close of Pennsylvanian time the axis of the great basin seems to have shifted over into the invaded region. 

a It is only in two publications-Stevenson, J. J., Carboniferous of the Appalachian Basin: Bull. Geol. Soc. 

America, vol. 17, p. 70 (note final correlations given under "Errors" in the reprint of this paper and others of the same 

series, 1907, p. 577), and White, I. C., Geol. Survey West Virginia, vol. 2 (A), 1908-that the new classification is 

applied in the stratigraphic description of the coal field. 
PENNSYLYANIAN. 445 

In crossing the coal field in the region of the upper Pottsville (Beaver River formation) 

overlap, we find thicknesses of 325 to 380 feet in Maryland; 572 245 feet on the Laurel Hill anticline, and about 200 feet on the Chestnut Ridge anticline, in Preston County, W. Ya.; and 

less than 200 feet in many of the bore holes farther west in that State; while along the western 

margin in Ohio and south to Ironton the Pottsville generally varies between 225 and 275 feet. 

All this is upper Pottsville. The reduced thickness of the upper Pottsville along the Allegheny 

Front in Cambria and Blair counties, Pa., and along the Allegheny Valley in the Foxburg and 

Kittanning quadrangles, is due largely to the absence of the lower member, the Sharon conglomerate, from these areas. The study of the region of upper Pottsville overlap reveals the 

existence of several low northeast-southwest barriers o.r slightly elevated areas between which 

there were basins containing the Sharon conglomerate member and the Sharon shale member. 

The first representative of older rocks (middle Pottsville) met in passing southward along 

the eastern margin of the bituminous coal fields is in the southeast corner of the Piedmont quadrangle, where, in the scarp of the Allegheny Front, the Blackwater formation, which includes 

all the Pottsville rocks of that area, measures 645 feet. Here we appear to have a part of the 

middle Pottsville, though in the northern and western portions of the same quadrangle only the 

upper Pottsville is present and is of the thickness noted. A considerable thickness of middle 

Pottsville, apparently underlain by some older or lower Pottsville, is described by I. C. White 9078 

as occurring on Cheat Mountain and in the region to the southwest. In the Buckhannon quadrangle the middle Pottsville is included in the Pickens sandstone, though the section here does 

not extend as low as in Cheat Mountain, to the east. The representatives of the middle and 

lower Pottsville in this part of the eastern border of the coal field are very much thinner than 

they are farther south, as will be explained in the description of these divisions in the New River 

region of West Virginia. 

A series of quadrangles studied by Campbell and his assistants, extending from the Pocahontas and New River coal region northwestward to and beyond Ohio River at Huntington, 

W. Va., embraces a complete section of the Pottsville from the deep early basin of the lower 

Pottsville out to the region of upper Pottsville overlap of the northern type. This section, 

which lies nearly midway of the Appalachian coal field, is taken by the writer as the typical 

or reference section of the central Appalachian region, though the divisions do not here attain 

their maximum thickness. 

In the Pocahontas quadrangle, 123 the first in this section to be mapped by the Federal 

Survey, occur the following formations, in descending order: 

Sewell formation: Shale, sandstones, and coals, lOO+ feet, incomplete. 

Raleigh sandstone: Conglomerate sandstone, 80 feet [invasion terrane]. 

Quinnimont shale: Shale, sandstones, and coals, 300 feet, overlying the Quinnimont [equivalent to the Fire Creek] 

coal. 

Clark formation: Sandstones, some shale, and coals, 380 feet, overlying the Pocahontas, or No. 3 coal. 

Pocahontas formation: Shale, sandstones, and coals, 360 feet, extending down to the red shales of the Mississippian, 

which are of Chester age. 

These formations are generally thinner in the Raleigh quadrangle, to the north, and are 

correspondingly thicker in the region along the border of the field to the southwest. 

The Raleigh, Charleston, and Huntington quadrangles, which present a cross section of 

the Pennsylvanian basin from the Allegheny Front in the region of the New River coal field 

to the vicinity of Ironton, Ohio, contain the following formations, the thickness of which is 

greatest to the southeast and least to the northwest. 
446 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Pennsylvanian formations in the Raleigh, Charleston, and Huntington quadrangles. 

[From folios of the Geologic Atlas of the United States, by M. R. Campbell.] 

Raleigh quadrangle, \Vest Virginia 

(folio 77, 1902). 

[Eroded.] 

Charleston sandstone, 500+ feet (coarse 

sandstone with several thick seams of 

coal). [Partly eroded. Extends down 

to the "Black Flint."] 

Kanawha formation, 1,000 ± feet (sandy 

and argillaceous shales and soft sandstone with numerous beds of coal). 

Sewell formation, 600-625 feet (sandy and 

argillaceous shale and sandstone): 

Nuttall sandstone lentil, 0-200 feet 

(massive sandstone or conglomerate). 

[Equivalent to the Fayette sandstone.] 

Harvey 'conglomerate lentil, 0-50 feet 

(massive conglomerate). 

Guyandot sandstone lentil, 0-100 feet 

(coarse sandstone or conglomerate). 

------------------

Raleigh sandstone, 75-150 feet (coarse 

sandstone or massive conglomerate). 

Quinnimont shale, at north 180-200 feet; 

at south 200-225 feet (sandy shale; 

Beckley coal at top; Quinnimont coal at 

base). 

At north. 

Thurmond formation, 450-550 feet 

(sandstone a n d 

shale). 

At south. 

Clark formation, 

350-375 feet. 

Pocahontas formation, 250-325 feet. 

Charleston quadrangle, West Virginia 

(folio 72, 1901). 

Braxton formation, 800+ feet (chiefly 

red and green shales and green sandstone, with beds of coarse sandstone 

and conglomerate at intervals). 

Charleston sandstone, 250-400 feet 

(coarse sandstone or conglomerate, 

with occasional bands of shale and 

beds of coal). 

Kanawha formation, 650-1,000 feet 

(shale and sandstone with many coal 

beds). 

Sewell formation, 100+ feet (sandstone, 

conglomerate, and shale, the latter 

containing several beds of workable 

coal). 

[290 feet to :\Iississippian at Winfield,] 

[Probably lacking.] 

[Lacking.] 

I 

Huntington quadrangle, West 

Virginia-Ohio (folio 69, 1900). 

Braxton formation, 800+ feet 

(chiefly red and green shales 

and green sandstone, with 

beds of coarse sandstone and 

conglomerate at intervals). 

Charleston sandstone, 200-30() 

feet (coarse sandstone or con- glomerate, with occasional 

bands of shale and beds of 

coal). 

Kanawha formation, 400+ feet 

(shale and sandstone with 

many coal seams). 

[Older formations lacking over, 

part of quadrangle.] 

Tho Pottsville formations up to and including the Raleigh sandstone compose tho lower 

Pottsville as here treated and 11ro collectively eorrelated by both the writer and Stevenson with 

the Lee formation of the quadrangles farther south, though the writer is inclined to believe that 

in some sections the lower beds of tho Sowell formation may have been included in tho Lee. In 

general, however, the correlation is accepted, and the term Lee is preferred as a geographic 

term to designate the lower Pottsville, that is, tho beds extending to the top of tho Raleigh 

sandstone. Palco botanically these beds are correlated 895r with tho ''Lower Lykens division" 

and tho "Lower Intermediate division" of the Pottsville type section in the anthracite region 

(seep. 440), the "Lower Lykens division," including Lykens coal ~o. 5 and underlying beds, 

being correlated with the Pocahontas formation or possibly the whole Thurmond formation, 

and tho higher zone, including the Lykens ~o. 4 coal, being referred to the Quinnimont 

formation. 
PENNSYLVANIAN. 447 

The Sewell formation constitutes the middle Pottsville and paleobotanically corresponds 

approximately to the "Upper Lykens division" of the type section of the anthracite region 

(seep. 440), which contains the floras characteristic of Lykens coals Nos. 2 and 3. It is made 

by Campbell, Stevenson, and I. C. White to include at the top the Nuttall conglomerate member 

(equivalent to the Fayette sandstone), which is correlated with the Sharon conglomerate member 

by the two geologists last named. The present writer, regarding the Nuttall as the initial 

sea-expansion member of the upper Pottsville subcycle of deposition, would prefer to separate 

it from the Sew.ell; and, while provisionally correlating it with the Sharon conglomerate member, 898ct would restore the latter to its old place in the base of the Beaver River formation, thus 

conforming to the early establishment of that division by Chance 135 and D'Invilliers. 285 Chance 

shows that the initial omission of the Sharon conglomerate member in the definition given by 

Lesley in the preface to I. C. White's Report Q (p. 65) was due to the misapprehension that the 

sandstone was Mississippian. 

The Kanawha formation is upper Pottsville and on the paleobotanic evidence corresponds 

roughly to the "Upper Intermediate division" of the type section of the anthracite region. 

(Seep. 441.) Together with the underlying Nuttall sandstone member and the sandstone which 

is just above the overlying black flint and which corresponds to the Homewood sandstone 

member, it is correlated by the writer with the Beaver River formation as already described 

for the northern strip (p. 441). 

The Charleston sandstone covers the entire Allegheny, here about 120 feet in thickness, 907h 

together with a portion of the Conemaugh and the heavy sandstone ("Roaring Creek" or 

Homewood) at the top of the upper Pottsville. Most of the Allegheny coals are thin or lacking 

in the Charleston and Huntington quadrangles. 

The Braxton formation represents the balance of the Conemaugh with so much (a small 

thickness) of the Monongahela as caps a few summits in the northwestern portion of the area. 

The remarkable reduction in the thickness of the Pottsville toward the northwest is due 

both to thinning of the divisions and to the disappearance of the older terranes as the section 

passes beyond the older and smaller early basin. At the same time the absence of paleontologic 

material from the drill holes makes it more difficult to determine the precise limits of the several 

divisions. The lower Pottsville, which appears to attain a thickness of over 1,200 feet in the 

vicinity of Norton, Va., in the Estillville quadrangle, is said to measure 1,080 feet on Barrenshc 

Creek, McDowell County, W.Va., in the Tazewell quadrangle; 815 feet at Wolf Gap, 907b Wyoming 

County, W. Va.; and 736 feet at Grand View, in the Raleigh quadrangle. Apparently it was 

not deposited in the Charleston quadrangle. It is less difficult, however, to distinguish the upper 

Pottsville in many of the sections in which the two lower divisions arc not clearly differentiated. 

Thus, at Powelton, Fayette County, W. Va., the Kanawha is reported by I. C. White 907g .at 

1,295 feet and the middle and lower Pottsville at 812 feet; at Hernshaw, a few miles south of 

Charleston, the upper is 890 feet and the middle and lower 787 feet; at Charleston the upper is 

600 feet and the middle and lower 660 feet; 5 miles farther west the upper measures 490 feet 

and the two lower divisions 480 feet; at Winfield, in the same quadrangle, the upper is 365 feet 

and the middle and lower combined 275 feet; whereas in the well at Letart, to the northwest, on 

Ohio River, the entire Pottsville measures but 360 feet, of which the lower 60 feet is perhaps 

referable to the middle Pottsville. The direction of most rapid thickening is somewhat east of 

south. At Naugatuck, on Tug River, in Mingo County, W.Va., the upper Kanawha is said by 

I. C. White 907f to measure 2,116 feet, a thickness that is possibly equaled in the Estillville 

quadrangle. 

The determination of the northernmost outcrop of beds of middle Pottsville age along the 

western border of the coal field is subject to differences of opinion. Stevenson 795e interprets 

the Jackson shaft coal, in Jackson County, Ohio, as just beneath the Sharon conglomerate 

member, and, placing the Sciotoville fire clays and coal at the same horizon, is inclined to regard 

the highest of the middle Pottsville terranes as a thin veneer extending as far north, at least, as 

Ohio River, with local developments of an underlying conglomerate (vicinity of Jackson, Ohio) 
448 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

which he correlates with Campbell's Rockcastle conglomerate lentil. But in the Kenova 

quadrangle the writer does not recognize pre-Sharon sandstones farther north than the southeast corner of the quadrangle. It is certain, however, that the middle Pottsville beds outcrop 

at the western border of the coal field not far south of the Kenova quadrangle and that successively lower beds are encountered in passing south through Kentucky; for in the folio on the 

Richmond quadrangle Campbell reports a thickness of 250 to 300 feet of Pottsville [part of which 

is erroneously included as Lee] below a 90-foot conglomerate (Corbin conglomerate lentil), 

which is correlated by Stevenson with the Sharon conglomerate member. This underlying 

series of beds includes the Rockcastle conglomerate member, a transgression deposit, to which 

reference will again be made. 

In the London quadrangle, next south of the Richmond, including portions of Rockcastle, 

Jackson, Laurel, and Pulaski counties, Ky:, Campbell finds beneath the Corbin 500 to 1,000 

feet of shales and sandstones that he maps as Lee, with the Rockcastle conglomerate 

member (0-150 feet), which probably forms the top of the true Lee, near the middle of the 

thick sections. a It is thus shown that in these quadrangles the western border of the coal field 

has been eroded far enough eastward to cut into the region of the middle Pottsville encroachment of the sea. The Rockcastle appears to represent the western extension of the Raleigh 

sandstone of southern West Virginia. From the London region southward erosion seems to 

have narrowed the field so that it lies wholly within the limits of the Raleigh-Rockcastle water 

level-that is, within the lower Pottsville basin. In the southern part of the Standingstone 

quadrangl-e, Tennessee, which lies in the second tier of quadrangles to the south of the London 

quadrangle, the Bonair conglomerate member, a sandstone over 200 feet below the Rockcastle 

conglomerate member (top of the lower Pottsville in Tennessee), outcrops along the western 

border. Farther south the Sewanee conglomerate of Safford and Killebrew is found to lie 

above the Mississippian and at some places nearly in contact with it. 8980 This conglomerate, 

long supposed to be continuous with the Bonair conglomerate member, has been shown by 

Butts to lie about 200 feet below the Bonair in the Crossville special quadrangle, Tennessee. 

The "Sewanee," which forms the top of Hayes's Lookout sandstone, constitutes an important 

early invasion or trangression member in the old Pottsville basin. 

In the northern part of the Standingstone quadrangle the Rockcastle conglomerate member, 

100 to 200 feet thick, is underlain by 100 to 300 feet of sandstone and shales belonging to the 

Walden portion of the Lee. In the south half of the quadrangle the Bonair conglomerate 

member, 125 feet below the Rockcastle and 100 to 200 feet thick, locally rests on the eroded 

Mississippian. The Rockcastle, which in this western region originates at the north as a remarkable gravel wash filling a river valley but a few miles in width, is blended toward the south 

with a sandstone of wide extent, which, according to Stevenson, is recognizable in nearly all 

the sufficiently complete sections of Tennessee and Kentucky. 

From the Standingstone quadrangle the coal field is mapped in consecutive quadrangles 

extending across the coal field from west to east near the southern boundary line of J 16 and also 

reaching southward to the Alabama line. 

Before referring again to the thick eastern sections the western border will be briefly 

reviewed. In the southern and eastern of these border quadrangles, whose study by Hayes antedates Campbell's work, just cited, the important sandstone designated by Safford and Killebrew as 

the Main Sewanee conglomerate was made the top member of the Lookout sandstone. Toward 

the northeast the Bonair conglomerate member, which for a time was, on paleobotanic grounds, 

considered possibly as young as the Raleigh, was made the top of the Lookout. However, as 

already noted, the Bonair is, according to Butts, the second sandstone above the Sewanee 

conglomerate of Safford and Killebrew, and the Sewanee is more than 600 feet below the top 

of the Lee formation in the Briceville quadrangle and the corresponding sandstone in the Kingston 

quadrangle. Accordingly the Lookout sandstone, which ends in the Sewanee conglomerate, 

represents but about one-half (the lower) of the Lee in this district. The beds above the Looka The Corbin conglomerate member (Q-150 feet) is overlain by 500 feet of the Breathitt formation, which is 

said by Stevenson to extend a little above the limits of the upper Pottsville. 
PENNSYLVANIAN. 449 

out in the southern quadrangbs are mapped as \Vaiden sandstone, the lower portion of which, 

including the Rockcastle conglomerate member, is accordingly represented in the Lee of the 

eastern quadrangles, as has just been shown. 

In the McMinnville quadrangle the Walden is reported as 250 feet thick, not thick enough 

to reach the middle Pottsville; while the Lookout, 200 to 300 feet thick, is here extended to 

cover the Bonair. Coals are present at the base and just beneath the Bonair ledge. In the 

Pikeville quadrangle, next eastward, 400 to 650 feet of \Vaiden strata, but slightly surmounting 

the Rockcastle, remain. These beds include several coals, the most important, near the base, 

being the Sewanee and Soddy coals. The Lookout, which attains a thickness of 650 feet, has 

several coals distributed through its section. 636 Walden beds, to a thiclmess of 500 feet, 

remain in the Sewanee quadrangle, which reaches nearly to the Alabama line. In this quadrangle the Lookout expands from 120 feet on the west to .510 feet on the east. The Upper 

Sewanee conglomerate of Safford, about 250 feet above his Main Sewanee conglomerate, in the 

Sewanee quadrangle, has been referred by Stevenson to the Rockcastle horizon. 

Even more than in the northern regions the terranes of the Pottsville of the southern Appalachian area are highly variable, both in character and in thickness, and are in some places 

lacking, so that it is difficult to follow many of the horizons, even when the work is continuous. 

Thin limestones or calcareous shales are present, especially in the lower Kanawha, and sediments 

with marine Mollusca are found here and there in each of the major divisions, but none of the 

marine faunas has yet been followed over a great area in the central and southern sections of 

the coal fields. For these reasons it was found most expedient by the United States Geological 

Survey in mapping the generally isolated areas of the southern Appalachian region to use for 

the Pennsylvanian subdivisions local formational names, which were applied to divisions differing as to lithologic characters or, in many cases, arbitrarily segregated for convenience in 

mapping. The detailed sections of the early publications, which unfortunately are very much 

scattered and which are generally either deficient in or erroneous as to broader correlations, 

have been well digested and thoroughly reviewed in a correlative way by Stevenson, who cites 

nearly all the fragmentary literature.a It may be noted that in most of the literatme antedating the publication of the Federal folios the upper beds of the sections, though of Pottsville 

age, are frequently referred to horizons as high as the Mahoning sandstone member of the 

Conemaugh formation or even the Monongahela formation. The data now available are.not 

sufficient to correlate with accuracy the subdivisions described in the detached areas covered 

by the folios, but the further study of the paleobotanic material already assembled will doubtless settle many of the points now in question. 

In the Tazewell quadrangle, to the west of the Pocahontns, several of the key rocks of the 

Raleigh quadrangle are missing. Campbell describes the following formations: 

Tellowa formation, 500 feet (incomplete), sandstones, shales, and coals. 

Sequoyah formation, 450 feet, shales and sandstones with coals. 

Dotson sandstone, 120 feet of sandstone overlying 60 feet of shales. 

Bearwallow formation, 60 feet, conglomerate. 

Dismal formation, 490 feet, shales, cqals, and sandstone, including a conglomerate lentil. 

Raleigh sandstone, 100 feet, conglomeratic. 

·welch formation, 700 feet, shales, sandstones, and numerous coals. 

Pocahontas formation, 360 feet, shales, sandstones, and coals, up to coal "No.3." 

a For eastern Kentucky see Crandall, A. R., Eastern Kentucky coal field: Geol. Survey Kentucky, vol. C, 1884; 

Moore, P.M., Geol. Survey Kentucky, new ser., vol. 1; Lesley, James, Geol. Survey Kentucky, vol. 4, 1861; Crandall, 

A. R., Geol. Survey Kentucky, new ser., vol. 6; Hodge, J. M., Preliminary reports on the southeast Kentucky coal 

field, 1887; Sullivan, G. M., Geology of parts of Jackson and Rockcastle counties, 1891; Loughridge, R. II., Geology of 

Clinton County, 1890; Norwood, C. J., Ninth Ann. Rept. Inspector of Mines, 1893, and Tenth Rept., 1894. 

For Tennessee see Safford, J. M., Geology of Tennessee, 1869; Bradley, F. H., in Killebrew and Safford, Resources 

of Tennessee, 1874. 

For Virginia see Rogers, W. B., Geology of the Virginias, and other State reports; Watson, T. L., Mineral resources of 

Virginia; Stevenson, J. J., Geological reconnaissance ofpartsofLee, Wise, Scott, and Washington counties, Va.: Proc. Am. 

Philos. Soc., vol.19, 1881; Hodge, J. M., The Big Stone Gap coal field: Trans. Am. Inst. Min. Eng., 1893; White, I. C., 

Geol. Survey \Vest Virginia, vols. 2 and 2A; and Stone, R. W., Bull. U.S. Geol. Survey No. 316, 1907, pp. 42, 55, 68. 

4801P-12--29 
450 INDEX TO THE STRATIGRAPHY OF NORTH .AM~ERICA. 

Of these the last three are lower Pottsville (equivalent to the Lee); and the Dotson sandstone is correlated by both I. C. White and the present writer with the Nuttall sandstone. 

The 60 feet of shales in the lower part of the Dotson, together with the Bearwallow and Dismal, 

therefore represent the Sewell, that is, the middle Pottsville. The Dotson sandstone, supposed 

to correspond to the Sharon conglomerate member, goes, along with the Sequoyah and Tellowa, 

which represent the Kanawha, into the upper Pottsville, the Sequoyah being in the lower half 

of that formation. 

In the two contiguous quadrangles, Bristol and Estillville, lying in the Big Stone Gap field, 

the Pennsylvanian syncline between the Pine Mountain fault and the eastern edge of the coal 

field contains, according to Campbell, the following: 

Harlan sandstone, 880 feet, sandstones, conglomerates and coals. [Not present in the Bristol quadrangle.] 

Wise formation, 1,260 feet, shales, sandstones, and coals, with several thin marine limestones. [Only 100 feet 

present in Bristol quadrangle, the rest of the formation being eroded away.] 

Gladeville sandstone, 100-120 feet, conglomeratic sandstones, between coals. 

Norton formation, 1,200-1,270 feet, shales, sandstones, and important coals. 

Lee formation, 1,240-1,530 feet, sandstones, conglomerates, shales, and few coals. 

In this reE:,rion, and on to the Tennessee line, the coals of the lower Pottsville are so unimportant and the sandstones so dominant that all are mapped in one formation, the Lee, which 

includes everything to the top of the Raleigh sandstone of the Tazew-ell quadrangle.a 

Stevenson 795i places the horizon of the Sharon conglomerate member and of its supposed 

southern representative, the Nuttall sandstone, in the Norton formation, at 800 or 900 feet 

below the Gladeville sandstone, the latter being identified by him as the sandstone just under 

the Upper Mercer coal on the west side of the coal field and therefore near the top of the upper 

Pottsville. On the other hand, the writer would place the Gladeville at or very little above 

the horizon of the Nuttall sandstone, making the Norton formation essentially equivalent to 

the Sewell-that is, the middle Pottsville-while the Gladeville itself, followed by the Wise and 

over 300 feet of the Harlan, which are found to contain Kanawha floras, are regarded by him 

as upper Pottsville. The horizon of the Homewood sandstone member, the top member of the 

upper Pottsville, is not yet fixed in the Harlan sandstone. The topmost beds in the "Flatwoods" of the region near Elkhorn, Ky., are put by the writer in the Harlan, the Flatwoods 

coal itself being of Kanawha age instead of representing the Pittsburg bed, as was formerly 

believed. 

The greater part of the Cumberland field, to the southwest of the Big Stone Gap coal field, 

has been studied by Ashley and Glenn, 41 whose work unfortunately fails to join with completeness Campbell's work, just cited, or Keith's, farther south. The formations described are as 

follows, those above the Lee being differentiated so as most satisfactorily to map the coal 

groups: 

Dryson formation, 300 feet, sandstones, shales, and thin coals above Red Spring coal. 

Hignite formation, 440-450 feet, sandstones, shales, and coals, down to lower Hignite coal. 

Catron formation, 280-450 feet, shales, sandstones, local conglomerates, and numerous coals above Poplar Lick coal. 

Mingo formation, ll50 feet, shales, sandstones, and good coals above the Bennett's Fork coal. 

Hance formation, 600 feet, shales, sandstones, and numerous thin coals. 

Lee sandstone, 1,200-1,500 feet conglomerates and sandstones, with thin shales and coals. 

The lower Pottsville (Lee) appears to continue in unity from the Estill ville quadrangle; 

the Hance and about half of the Mingo represent the Sewell, the Gladeville being provisionally 

placed by both Ashley and White 41b,b in the region of the Slater and Puckett sandstone members, 

a little above the middle of the Mingo formation. The Catron and Hignite formations, which 

contain Kanawha floras, together probably with the upper part of the Mingo and certainly with 

the basal portion of the Bryson, are included by the writer in the upper Pottsville. The Bryson 

which, capping the highest knobs and ridges is present only in the deepest synclines, is there 

equal in part to the Harlan of the Big Stone Gap region. 

a For information concerning the intervening area see Stone, R. W., Bull. U.S. Geol. Survey No. 316, 1907, 

pp. 42, 55; Dull. 348, 1908. 

b See same paper also for correlations with other regions. 
PENNSYLVANIAN. 451 

The area in Tennessee mapped by Keith begins not far beyond the region mentioned and 

joins, on the south, the district studied by Hayes. It includes the Briceville and Wart burg 

quadrangles,a which present a complete cross section of the coal field. The formations, distinguished on lithologic grounds, are as follows: 

Pennsylvanian formations in Briceville and Wartburg quadrangles, Tennessee. 

Briceville. Wartburg. 

Anderson sandstone: Shales, sandstones, conglomerates, and coals. [Eroded.]. ........... . Scott shale: Sandy shales, sandstones, and coals ....................................... . Wartburg sandstone: Sandstones, shales, and coals .................................... . Briceville shale: Shales, sandstones, and coals ........................................ . Lee formation: Sandstones, conglomerates, and thin coals .............................. . 

Feet. 

1, OOO+ 

650-500 

650-500 

650-250 

1,500-500 

Feet. 

500+ 

600-500 

600-500 

400-250 

900-375 

It is suspected that the maximum Lee here may extend one sandstone higher than in the 

regions to the northeast, though the Big Creek Gap outcrop of the Lee, near the eastern margin 

of the Briceville quadrangle, is given by the writer 41a as about 1,250 feet thick. In general, 

however, the Lee is doubtless essentially equivalent to the division under the same name farther 

east, the variations being probably local. The inclusion of middle Pottsville terranes in the 

"Lee" of the Richmond and London quadrangles in Kentucky has already been mentioned. 

The Sewell age of the Briceville shale is agreed on, and the horizon of the Corbin (equivalent to 

the Nuttall sandstone) is placed by Stevenson 79'h in the bottom of the Wart burg sandstone. 

The Scott shale, together with the upper part of the \V art burg and the lower part of the Anderson 

sandstone are correlated, on the paleobotanic evidence, with the Kanawha, and therefore 

placed in the upper Pottsville. The lack of prospecting and exposures of the soft beds on the tops 

of the mountains have rendered the acquisition of fossil plants very difficult, and the Allegheny.,. 

Pottsville boundary is still uncleterminecl. However, the Anderson of these quadrangles, the 

Bryson of the Cumberland basin, and the Harlan of the Big Stone Gap field are paleobotanically 

shown to be in part contemporaneous, each seeming to reach up into the post-Pottsville. It is 

probable that the highest beds of these formations, occurring only on the top of a few of the 

highest mountains of these regions and, in Tennessee, limited to these two quadrangles, comprise 

the last and only Allegheny Pennsylvanian remaining in all this southern region of the coal 

fields. 

For comparison the section given by Campbell for the southern half of the Standingstone 

quadrangle, west of the VV art burg, is repeated: 

Lee formation: 

Rockcastle conglomerate lentil; 100-180 feet, sandstone and conglomerate. 

Shale and sandstone, 125 feet. 

Bonair conglomerate lentil, 100-200 feet, conglomerate, sandstone, with inclosed or underlying 

coals, resting on the Mississippian. 

The total of these divisions, about 375 feet b at the western outcrop in this quadrangle, 

agrees with the western outcrop measurements of the eastern Lee, given by Keith as 375 feet 

in the vVartburg quadrangle to the south. Stevenson's correlation of Campbell's Rockcastle of 

the western region with the top Conglomerate of the true Lee as mapped along the eastern 

margin of the coal field appears to be well established. 

The Sewanee conglomerate of Safford and Killebrew, which along the western margin of 

the coal field in this region, this being the region of "Sewanee" transgression, locally rests 

a The Cumberland basin terminates on the southwest in a faulted cross anticline, along Fork Mountain, in the 

Briceville quadrangle. 

b The total, including the Rockcastle and underlying Pennsylvanian beds in the northern half of the Standingstone 

quadrangle, is given by Campbell as 200 to 400 feet. 
452 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA" 

almost directly on the Mississippian, or is even absent, is, over most of the area, continuous as 

the upper member of the Lookout of Hayes. 

The section of the Tennessee coal fielrl lying south of the Briceville tier of quarlrangles is 

included in the area mapped by Hayes at an early date in the work of the United States Geological 

Survey and is practically covered by the Kingston, Pikeville, McMinnville, Chattanooga, and 

Sewanee quadrangles. The measurements of the Pottsville formations are as follows, from east 

to west: 

Thickness, in feet, of Pottsville formations in southeastern Tennessee. 

--------- ----- ~-~ 

I 

Kingston I 

Chattanooga Pikeville I I Sewanee McMinnville 

I quadrangle. I quadrangle. quadrangle. quadrangle. quadrangle. 

I - ---

Walden sandstone: l,HOO+ 600-700+ (with two 400-650+ 300-500-f- 250+ 

Shales, sandstones, or more conglomconglomerates, and erates). numerous coals, the 

most important being 

two in the first 100 feet 

above the base of the 

formation. 

Lookout sandstone: 260-510 (with coals 450-550 90-650 (made to in- 120-510 200-350 

Sandstones, conglomer- at various points dude the Bonair 

ates, and workable below the top co ngl om erate 

coals; the Main Se- c on g 1 om e rate member in wanee conglomerate member). north west corner of Safford at the top. I of quadrangle). 

I 

Some uncertainty exists as to the identification of Safford and Killebrew's Sewanee conglomerate in the vicinity of Chattanooga. Stevenson, 795 g reviewing the details published by 

Safford 687b and Colton, 555 concludes that the top of that terrane is 215 feet higher at the Whiteside (old Etna) mines, 235 feet higher at Daisy, and 234 feet higher at Rathbun than the position 

assigned it by Hayes at these points, though at Graysville and other points to the northeast in 

the Kingston quadrangle, there is agreement. The Upper Sewanee conglomerate of Safford, 

in theW alrlen 240 feet above his Main Sewanee conglomerate (long regarded as equivalent to the 

Bonair) at Tracy City, in the Sewanee quadrangle, is questionably correlated by Stevenson with 

the Rockcastle, the top of the Lee, and regarded as probably equivalent to the Raleigh. The flora 

·of the Sewanee coal, about 50 feet above the Lookout at Tracy City, is somewhat like that of the 

Sowell coal in West Virginia and was therefore made the basis of one of the writer's earliest 

preliminary correlations in the southern Appalachian region, the underlying conglomerate 

being then correlated by him with the Raleigh. However, from his later paleobotanic and stratigraphic work it appears that if the sandstone at the top of the Lookout in the Kingston quadrangle is correctly identified with the ''Main Sewanee conglomerate" as developed at Tracy 

City, as appears to be true, a thickness of over 600 feet intervenes between the top of the 

Lookout and the top of Keith's Lee in the Emory Gap region of the Briceville and Kingston 

quadrangles, where the upper massive Rockcastle conglomerate member, 100 feet thick, about 

500 feet above the "Sewanee," is the same as Safford's and Killebrew's Emory sandstone, 690 

forming the top of the Lee in Emory Gap, near the south border of the Briceville quadrangle. 

The correlation as Corbin (equivalent to Kuttall) by Stevenson of a conglomerate member 

only 100 feet above the supposed Rockcastle conglomerate member in the Pikeville quadrangle would seem to assume a too rapid thinning of the middle Pottsville in passing from the 

Briceville quadrangle across to Clifty Creek. 

In the Kingston and Chattanooga quadrangles the lower Pottsville seems neither to expand 

so rapidly eastward nor to exhibit so great a thickness as is found in the eastern basins of 

Virginia and Alabama. 
PENNSYLVANIAN. 453 

SOUTHERN APPALACHIAN REGION. 

Tho southern portion of the Appalachian coal field falls in the geographic unit I 16, and 

lies mostly in Alabama, though it cuts the northwest corner of Georgia. At the northern line, 

opposite Chattanooga, the residual area of tho Pennsylvanian is less than 30 miles wide. From 

this it expands to a width of 85 miles along its southern exposure. On the east, where the 

longitudinal folding, locally accompanied by overthrusting, is stronger, tho coal field is gashed 

by several anticlinal valleys, while farther east several synclinal areas are wholly detached. 

The three most important of the latter are the highly elevated Lookout Mountain syncline, 

extending south from Chattanooga; the deeply set Coosa field, a complex synclinorium south 

of Lookout Mountain, lying farthest east of the three; and tho Cahaba syncline, ranging through 

nearly the same latitude, about midway between the Coosa and the main Warrior field on the 

west. Overthrust faulting, not uncommon along the eastern margins of the synclines, is 

especially notable along the eastern border of the Cahaba field and the Warrior field south 

of Birmingham where Cambrian strata arc thrust on beds of the middle Pottsville. The 

Walden Plateau east of the Sequatchie Valley, extends into Alabama as Raccoon Mountain, 

and the Cumber1and Plateau, continuing as a plateau though ruptured by several anticlines, 

is called Sand Mountain in northern Alabama. Subordinate folds produce oblique lobes or 

branches of the eastern synclines. 

In passing westward the folds die out and the beds rise gradually northwestward to fringe 

the main field with irregular lobes and isolated patches, comparable to those along the western 

and northern borders of the great Appalachian basin; but to the south and west in Alabama 

the Pennsylvanian disappears beneath a Cretaceous mantle in the great Gulf embayment. 

How far the coal measures extend beneath this southward-thickening cover has not been 

ascertained. It is nearly certain that on the west they blend with the Pennsylvanian of the 

eastern interior lobe. It is probable that at the stage of Kanawha (upper Pottsville) encroachment union with that lobe occurred in Tennessee or perhaps in Kentucky. 

We have seen that in southern Tennessee the lower Pottsville, perhaps slightly thinner than 

it is farther north, appears not to expand eastward as rapidly as the middle Pottsville, but in 

Alabama we find a marked southeastern expansion of the lower as well as of the middle division. 

The general characters of the Pennsylvanian in the greatly elevated and much eroded 

northern region are shown in the Ringgold and Stevenson quadrangles, geologically mapped by 

Hayes, and in the Gadsden quadrangle, which, lying southwest of the Stevenson, cuts three of 

the eastern synclines, including the south end of Lookout Mountain. 

Thickness, in feet, of Pottsville formations in northwestern Georg-ia and northeastern Alabama. 

Ringgold I Stevenson Gadsden 

quadrangle. quadrangle. quadrangle. 

'Vaiden sandstone: Coarse sandstones, sandy shales, good coals, and clays ...... 930 500+ 600+ 

Lookout sandstone: Sandstones, conglomerates, sandy shales, and interbedded 

[eroded] 

coals; has heavy cliff, usually conglomerate, at top ..... __ . ___ .. _._._._._._ 200-550 300-400 60-570 

It will be noted that the Gadsden quadrangle is nearly "in strike" with the Ringgold, 

which explains the similarity in the thickness of the Lookout. The highest fossils collected in 

the Lookout Mountain syncline, from beds reported as about 600 feet above the Lookout, suggest the basal horizon of the middle Pottsville. It is therefore very doubtful if any upper 

Pottsville is present in these quadrangles, which contain the highest beds in this northern section of the State.a 

a For detailed sections outside of the folios cited, see ~IcCallie, S. M., The coal deposits of Georgia: Geol. Survey 

Georgia, 1906; l\IcCalley, II. B., Coal measures of the Plateau region: Alabama Geol. Survey, 1891; Spencer, J. W., 

Paleozoic group: Geol. Survey Georgia, 1893; Hayes, C. W., Twenty-second Ann. Rept. U. S. Geol. Survey, pt. 3, 

1902, Pl. XIV. For discussions of ~ections see Stevenson, J. J., Bull. Geol. Soc. America, vol. 15, p. 126. 
454 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The Blount Mountain synclinal lobe, southwest of the Gadsden quadrangle, appears to be 

intermediate to the Warrior field. The stratigraphy as described by A. l\1. Gibson presents an 

enlarged number of divisions which show a marked expansion, notably in the lower Pottsville. 

Though not paleontologically correlated, they appear to be stratigraphically referable to the 

divisions in the Warrior basin next beyond. 

In the Warrior field the downward pitch of the synclines on passing from the Plateau 

(northern) district permits the retention of a great thickness, over 3,000 feet, of strata. At the 

same time the divisions, particularly the lower Pottsville, appear greatly thickened. In McCalley's detailed studies of this field 556 the individual coals have been traced with great success 

over the greater portion of the area. In the following summary of the divisions of this field the 

sections above the lowest important coal, the Black Creek coal, are given (in averages) for the 

eastern border of the field, the Warrior River section, and the edge of the Cretaceous overlap on 

the west. The series below the Black Creek coal is continued by McCalley's average section for 

Jefferson County,554 which is placed in the middle column. 

Thickness, in feet, of Pottsville stmta in the Warrior basin region of Alabama. 

Eastern 

border. 

1. Interval of shales, conglomerates, and sandstones......................... 50 

2. Brookwood coal group; five coals .............. :....................... 125 

3. Interval of shales and sandstones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 

4. Gwinn coal group; two coals........................................... 38 

5. Interval of shales, sandstones, and conglomerates......................... 175 

6. Cobb coal group; three coals .......................................... ' 170 

7. Interval of shales, sandstones, and local thin limestones. . . . . . . . . . . . . . . . . . 116 

8. Pratt coal group; five coals............................................ 160 

9. Interval of shales, sandstones, and conglomerates......................... 340 

10. Horse Creek (Mary Lee) coal group; five coals........................... 134 

11. Interval of shales, sandstones, conglomerates, and local limestones........ 100 

12. Black Creek coal group; three coals.................................... 70 

13. Interval of shales, sandstones, local limestones, and ten coals, from Black 

Creek coal to top of "upper conglomerate" of Tennessee ......................... . 14. Interval of sandstones, conglomerates, shales, and coals, from top of "upper 

conglomerate" of Tennessee to top of "lower conglomerate" of Tennessee ............ . 15. Interval of conglomerates, shales, and coals, from top of "lower con- glomerate" ("Millstone grit") to Mississippian ................................... . 

Along 

Warrior 

River. 

150 

108 

250 

32 

160 

136 

170 

166 

260 

148 

68 

85 

1,243 

100 

Western 

border of 

exposed 

"Coal 

Measures." 

25 

100 

125 

23 

125 

67 

210 

140 

210 

106 

63 

56 

90 1· .•.•..••.•• 

I 

According to the preliminary correlations by the writer, based on the incomplete study of 

the Pottsville floras, the sandstones of the Lookout become greatly broken up and parted, with 

expanded intervals of varying materials, while at the same time earlier beds of lower Pottsville 

age are assumed to underlie those in contact with the Mississippian at the Tennessee line. He 

correlates the entire lower part of the section, including the conglomerate and sandstone interval 

(No. 11) above the Black Creek coal group (the whole averaging about 1,575 feet), with the 

Lookout. The Horse Creek coal group and its overlying conglomerate series, making when 

added to the other about 1,900 feet, is provisionally placed, on the fossil plant evidence, in the 

lower Pottsville, No. 9 of the· section being tentatively correlated with the Raleigh sandstone of 

the central Appalachian sections. The Horse Creek coal group (Mary Lee) and No. 9, taken 

together, may be found to represent the recognized difference between the top of the Lookout 

on the east side of the Tennessee strip and the top of the Lee farther north. 

The Pratt and Cobb coal groups are middle Pottsville, in which the Gwin also belongs, 

making a total of about 670 feet, and a part of No. 2 should probably also be included. It is 

thought, however, that the study of the Brookwood (No. 2) plants may show them to be of 

upper Pottsville age. 

The Cahaba coal field, a few miles east of the Warrior field, occupies a deep-set and compound syncline about 40 miles long and 3 to 6 miles in width. A part of its western margin is 

overturned, and older Paleozoic rocks are thrust on the coals along the eastern border. This 
PENNSYLVANIAN. 455 

field was studied and mapped in detail by Joseph Squire 773 and the greater portion of it has 

recently been reexamined by Charles Butts. 107• 113 

Squire divides the section, calculated to average 5,525 feet, into four parts, which, in descending order, are as follows: 

"Conglomerate group," 475 feet, four coals intercalated with conglomerates, and extending from the Montevallo 

coal to the top of the section. 

"Productive group," 2,200 feet, sandstones, shales, and 28 coals, including the Helena coal at 240 feet, a conglomerate (called Thompson) at 310 feet, and the Little Pittsburg coal at 655 feet below the top of the "group;" the Adkins 

coal, 790 feet lower; and the Wadsworth coal, 500 feet lower, or about 240 feet above the base of the "group." 

"Micaceous group," 1,0.55 feet, micaceous gray and coarse pink sandstones and grits, with seven coals intercalated; 

the Hark'ness coal, 160 feet below the top, underlain by 275 feet of sandstones and grits; theN unnally coal165 feet above 

the base. 

"Millstone Grit group," 1,795 feet, conglomerates, sandstones, and six coals; the main sandstone masses at the 

top (360 feet), in the middle (650 feet), and just below the latter (340 feet); the Gould coals in the basal portion. 

The section given by Butts agrees in most points with that abstracted above, though 

indicating an average total thickness of over 6,100 feet in the regions studied. It seems probable 

that the deeper southeastern portion of the field will ultimately be found to have a depth of 

7,000 feet or more. The "Millstone Grit group" is correlated by Butts with the Lookout 

sandstone. On the fossil plant evidence at present available, the writer is disposed to include 

the Nunnally and Harkness coals (in the lower part of the" Micaceous group") also in the Lookout. At least they are of lower Pottsville age. The paleobotany of the Wadsworth coal group, 

which is thought to be as old as the Horse Creek coal group of the Warrior field, will prob-. 

ably be found to place this division also within the limits of the lower Pottsville, the Little 

Pittsburg-Helena coal group belonging to the middle Pottsville. Fossils of upper Pottsville 

age have not yet been recognized in the Cahaba field. These preliminary correlations indicate 

both a very great thickness and a tremendous expansion of the terranes to the southeast in 

Alabama. 

The Coosa field, a short distance east of the Cahaba field, is about 40 miles long and 4 to 

10 miles broad. The coal measures are overlain by overthrust Lower Cambrian on the east. 

Though this field was the scene of the first coal mining in the State, at least 12 workable coals 

being reported by the Alabama geologists, its deformation has been so violent and the folds 

are so complicated and the exposures of the soft beds so meager that little successful development 

has been accomplished, even in the north end of the field. Very little detailed geologic work 

has been done in the basin. A report on the field by A. M. Gibson 359 shows a section which 

exceeds 5,000 feet and which appears to be stratigraphically similar to that of the Cahaba field, 

though there is said to be further eastward expansion of the groups. The greater part of the 

reported thickness apparently belongs to the lower Pottsville. The basin lies low and, like the 

Cahaba, passes under the Cretaceous to the south. No paleontologic studies of the Pennsylvanian of this basin have been made. 

1-K 14-15. WESTERN INTERIOR COAL REGION. 

The following statement was prepared for this volume by G. H. Ashley in 1909: 

GENERAL FEATURES. 

The Pennsylvanian of the western interior coal region covers a large area in Iowa, Missouri, 

Nebraska, Kansas, Arkansas, Oklahoma, and Texas, the area exposed being a part, possibly 

only a small part, of that originally covered. The area of exposure has been much reduced on 

the southeast by folding and faulting, on most of the eastern edge by erosion, and along all of 

the west and southeast sides by the deposition of a mantle of later rocks. In central Arkansas 

the southeastern edge of the outcrop passes beneath a cover of Tertiary rocks. Farther west 

and south the Pennsylvanian is hidden by Cretaceous and Permian rocks. The extension to 

the west in Iowa and most of Kansas is concealed by Cretaceous rocks; across Kansas, Oklahoma, and Texas by Permian rocks. Deep drilling for oil and gas indicates a continuance to 

the west of the Pennsylvanian rocks, so far as the series is reached by such drilling, but they 

may be assumed as extending indefinitely beyond. 
456 INDEX TO THE STRATIGHAPHY OF NORTH AMERICA. 

The older Pennsylvanian deposits are confined to the southeastern part of the region, in 

Arkansas and Oklahoma, and correspondingly in that region is found the greatest thickness of 

rocks. Later a series spread northwestward and westward over Kansas, Missouri, Nebraska, and 

Iowa. The Pennsylvanian of northeastern Missouri and southeastern Iowa would seem to have 

been at one time connected with the ''Coal Measures'' of Illinois. Whether the series in Arkansas has extended southeastward to join with the Appalachian field in Alabama is uncertain. 

SCBDIVISIONS. 

For purposes of study the region may readily be divided into four subareas. The KansasMissouri-Iowa area is characterized by rocks nearly all of which are of post-Pottsville age, 

that are easily divisible into the "Upper Coal Measures" and "Lower Coal Measures," by 

common elements in their stratigraphy, and by• simple monoclinal and basin structure. The 

Pennsylvanian of Oklahoma and Arkansas may be divided into two subareas by a great fault 

or fault zone, extending from Atoka to the northeast and east, crossing Arkansas River about 

40 miles above Little Rock. The area north and east of this fault, which may be called the 

Arkansas Valley field, differs from the Kansas-::Vlissoul'i-Iowa area in structure and in stratigraphy, there being a great thickening of the series from Kansas to the southwest, where the 

strata are underlain by older Pennsylvanian rocks. In the main this area is gently folded and 

faulted. The area south of the great fault, which may be known as the Ouachita region, differs 

from the area last mentioned in its stratigraphy, notably in the presence of a great series of 

shale and sandstone not found outside of this area, and in structure, its rocks having been 

closely folded and markedly faulted, and possibly overthrust upon the rocks to the north. The 

northern Texas area is cut off from the areas to the north by the Arbuckle uplift. It is plainly 

a continuation of the northern Arkansas-Oklahoma area, though differing greatly in its stratigraphic details. 

IOWA-MISSOURI-KANSAS AREA. 

The Pennsylvanian in Iowa, Nlissouri, and Kansas outcrops over an area of 63,000 square 

miles, distributed, according to Bain, 50 as follows: Iowa, 20,000; Missouri, 23,000; Kansas, 

20,000. Bain 50a describes the "Coal Measures" in these States as follows: 

"The Coal Measures of the western interior field * * * rest unconformably upon the 

rocks of the Lower Carboniferous or Mississippian series. They are covered in Kansas and 

Nebraska by the Permo-Carboniferous beds, which are conformable with them. In Iowa 

Cretaceous deposits rest unconformably on them, and in Iowa, Nebraska, northern Missouri, 

and northeastern Kansas the drift and associated deposits of the Pleistocene cover the coalbearing strata. 

"The Coal Measures of this field include limestones, sandstones, shales, fire clays, and the 

coal beds proper. Limestones are probably least abundant, and shales in their various phasesargillaceous, bituminous, calcareous, and arenaceous-most abundant. In the northern portion 

of the field limestones and calcareous shales are notably more abundant in the upper or barren 

portion, and less so in the lower or productive portion. In Kansas the distinction between the 

two divisions is not so well preserved, and in the adjacent southwestern field it quite loses value. 

In a general way there is a prevailing dip to the west of 10 to 20 feet per mile. In detail the dip 

is south to southwest in Iowa, west to northwest in ::Vlissouri, and predominantly northwest in 

Kansas. 

"The Coal Measures of this field increase in thickness westward from their outcrop. There 

is also a gradual increase in maximum thickness from north to south. In Iowa the maximum 

thickness measured is 1,060 feet. a In Missouri Winslow has estimated the total thickness at 

2,000 feet. b In Kansas Haworth gives 3,000 feet as the thickness. c 

"On the maps accompanying this report two divisions of the Coal Measures are represented. These are the Upper and Lower Coal Measures. In Iowa and :Missouri the terms -----~--------------

a Norton, W. H., Iowa Geol. Survey, val. 6, p. 333. 

b .Missouri Geol. Survey, val. 1, Preliminary report on coal, p. 24. 

c Univ. Geol. Survey, val. 3, p. 20. 
PENNSYLVANIAN. 457 

Des }foines and Missourian, respectively, are used for the two divisions. In Kansas these terms 

have not been used, although essentially the same division is recognizecl The basis of the divi~ 

sion is largely lithologic and economic. The Coal Measures in this field belong to one series 

and represent a continuous sequence of deposition. The faunal change at the dividing line is 

slight, but the division is none the less valid and important. The Lower Coal Measures include 

the bulk of the productive coal beds throughout the field. From 93 to 98 per cent of the coal 

mined comes from them. These beds are relatively thick, are notably irregular, and show a 

patchy distribution. They are associated with thick sandstones, thick bodies of shale, par~ 

ticularly of bituminous and argillaceous types, and with thin and unimportant limestones. 

The Upper Coal Measures include a few very thin beds of coal of great regularity and extent. 

They are associated with little sandstone, and with shale usually calcareous or argillaceous 

in type. The measures also include a notable number of thick and persistent limestones. As 

already stated, these differences are not pronounced to the south, though even here the general 

relations are as stated above. The dividing line is drawn at the base of an important limestone, 

40 to 80 feet thick, known variously- as the Winterset, Bethany, or Erie. The general equivalence of these three terms is well recognized, though there is as yet some doubt as to the exact 

correlation of this and other minor divisions. a Subdivisions of both the Upper and Lower Coal 

Measures have been systematically recognized and mapped in Kansas by Haworth and his 

associates. b In Missouri corresponding divisions have been recognized and partially mapped by 

Keyes c and Marbut. a In Iowa divisions of the Lower Coal Measures have been recognized e 

but have not been mapped except in Appanoose County./ 

"The divisions recognized in each State and their approximate correlation are shown in 

the following table. Keyes has suggested more exact nomenclature and correlation.c His 

suggestions have not as yet been followed in mapping. 

Divisions of the Lower Coal 1lfeasures. ---------------------------- ---------------------------

________ K_a_n_s_as--(H_a_,_~o_r_th_)_. ________ .,----~~0~~~~~---- Iowa (Geol. Survey). 

Pleasanton. 

Appanoose and equivalents. 

Pleasanton/ Altamont . u · d mara1s es Cygnes ............. . Pawnee ... Marmaton ............. · · · · · · {H · tt Labette... enne a.·· ............... .. 

Fort Scott. 

Cherokee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cherokee ..................... . Cherokee. 

"It will be seen that the Lower or Productive Coal Measures are made up of three divisions. 

The uppermost, the Pleasanton shales, including the Altamont limestones, attain a thickness 

in Kansas of 200 feet. To the north they thin, until in central Iowa they are hardly to be separated from the next lower member. In Kansas they have been grouped with this middle division 

by Haworth under the name Marmaton formation. g The middle member passes under various 

names in different parts of the field. In Kansas it includes the Pawnee and Fort Scott limestones, with the intercalated Labette shales, and has an approximate thickness of 150 feet, a 

thickness which it maintains well to the north. In southwestern Missouri the shale member 

of the sequen.ce is unimportant, and the limestones, the Henrietta formation of Keyes,h form a 

single escarpment, which may be seen near Hume, in Bates County. In northern Missouri 

and southern Iowa the formation includes a number of thin limestones separated by shales and 

carrying thin coal seams. This is the phase of the formation which has been called the Appa-

"Haworth, E., Kansas Univ. Geol. Survey, vol. 3, pp. 101-102. 

b Kansas Univ. Geol. Survey, vols. 1 and 3. 

c Bull. Geol. Soc. America, vol. 12, pp. 173-19G. 

d Missouri Geol. Survey, vol. 12, Olinton, Calhoun, Lexmgton, Richmond, and Huntsville sheets. 

e Iowa Geol. Survey, vol. 5, pp. 374-398; vol. 6; vol. 8, p. 82. 

I Iowa Geol. Survey, vol. 5. 

g Haworth, E., Kansas Univ. Geol. Survey, vol. 3, pt. 6, 1898. 

h Bull. Geol. Soc. America, vol. 12, 1901, p. 176. 
458 INDEX TO THE STRATIGRAPHY OF NOR'l'H AMERICA. 

noose. In central Iowa there are beds equivalent to the Henrietta, but the sequence of strata 

is different. 

"The lowest member of the measures is the Cherokee shale, which outcrops in a crescentshaped area following the outer lines of the outcrop of the Coal Measures from Kansas to northcentral Iowa. The shales vary in thickness from 200 to 600 feet along the outcrop of the next 

higher formation anu thin to nothing at their own outcrop. The formation is made up largely 

of shale and sandstone anu carries numerous important coal beds. The individual strata vary 

in character and thickness from point to point, so that it is impossible to construct a general 

section of more than local value. In the southwest, especially in southeastern Kansas and the 

adjacent portions of Missouri, the beds are apparently more regular than elsewhere, and the 

irregularities found farther north serve to mark this as an exceptional portion of the field." 

The persistent limestones of the "Upper Coal Measures," as well as the intervening shales, 

have all been named in Kansas. In many reports these have been consiuered as separate 

formations. In other reports they have been treated as members of somewhat more inclusive 

formations. Later work has shown that the earlier correlations of some of the limestones at 

different points were erroneous. Again, some of the earlier names used have later been found 

to be preoccupied by use for some other formation elsewhere. These facts have led to many 

changes in the nomenclature of the Pennsylvanian of Kansas. 

In the table opposite is presented the stratigraphy of the Pennsylvanian of Kansas, as 

contained in several .recent reports. Bulletin 211 of the United States Geological Survey gives 

the synonymy of the several formations listed, with the fauna of each formation or member. 

Bulletins 238 and 296 show the groupings and treatment of the rocks at still later dates, and 

the latest is that quoted from volume 9 of the State report. 

ARKANSAS VALLEY AREA. 

The area of Pennsylvanian strata of Kansas, Missouri, and Iowa is, in large measure, cut 

off from the Arkansas Valley area on the south by the Ozark uplift. The two areas are connectetl by a relatively narrow belt of outcropping rocks running southwestward through eastern 

Oklahoma. In this narrow area, which has not been studied as much as the regions to the 

north and south, there is a notable thickening of the formations toward the south; a running 

out of the limestones, so characteristic of the formations of Kansas, and the introduction of 

sandy beds; and a downward transgression of the red clay, which to the north is characteristic of the Permian beds but which in this region extends downward into the upper part of 

the Pennsylvanian. As a result of these changes the stratigraphy of the Pennsylvanian in 

central Arkansas and eastern Oklahoma is very different from that in Kansas. In part the 

increased thickness is due to the appearance of older Pennsylvanian strata at the bottom of 

the series. 

The second table opposite shows the stratigraphic nomenclature, with the thickness of some 

of the strata, as given in the reports of the more important studies made in this field, in addition 

to a correlation with the Pennsylvanian to the east, based entirely on the work of David White. 

For comparison, Purdue's section 655a in western Arkansas (Pike, Howard, and Sevier counties) and an abbreviated section from Kansas are also given. The Mississippian formations 

underlying the Pennsylvanian in these sections are includeu in the table to show the character 

of the contact at different points and as bearing on the stratigraphy of the Ouachita region. 

OUACHITA AREA. 

As already stated, the Ouachita area is cut off from the Arkansas Valley area by a great fault 

or fault belt extending from Atoka northeastward and eastward. South of this fault the rocks 

are closely folded or overturned as well as faulted. The result of this faulting and folding has been 

to greatly shorten the north-south extent of the area covered by the Pennsylvanian. The writer 35 

has estimated that in the southern part of this area a section along Cossatat River, now 24 miles 

long, was originally 35 miles long, and a section on Antoine Creek, now 20 miles long, was originally 

also 35 miles long. As this estimate does not make any allowance for overthrust faulting, and 
Stratigraphy of the Pennsylvanian of Kansas, as interpreted by different authors. 

Haworth, E., Geol. Survey 

Kansas, vol. 3, 1898, p. 

94. (Kansas.) 

Cottonwood formation: 

Cottonwood shales. 

Cottonwood limestone. 

Wabaunsee formation, a series of alternating limestones and shales to which 

individual names have 

not yet been given. 

Burlingame limestone: 

Shawnee formation: 

Osage shales. 

Topeka limestones. 

Calhoun shales. 

Deer Creek limestone. 

Tecumseh shales. 

Lecompton limestones. 

Lecompton shales. 

Douglas formation: 

Oread limestones. 

Lawrence shales. 

Pottawatomie formation: 

Garnett limestone. 

Lane shales. 

lola limestone. 

Thayer shales. 

Erie limestones. 

Marmaton formation: 

U p p e r Pleasanton 

shales. 

Altamont limestone. 

Lower P l e a s a n t o n 

shales. 

Pawnee limestone. 

Labette shales. 

Oswego limestones. 

Cherokee shales. 

Keyes, C. R., Bull. Geol. 

Soc. America, vol. 12, 

1901, p. ,175. (Mississippi Valley.) 

Missourian: 

Cottonwood limestone. 

Atchison shales. 

Forbes limestones. 

Platte shales. 

Plattsmouth 

stones. 

limeLawrence shales. 

Stanton. limestone. 

Parkville shales. 

lola limestones. 

Thayer shales. 

Bethany limestones. 

Des Moines: 

Marais des Cygnes 

shales. 

Henrietta limestones. 

Cherokee shales. 

Boone limestone (Missis- Kaskaskia, etc. 

sippian.) 

48011°-12. (To face page 458.) No.1 

Adams, G. I., Bull. U. S. 

Geol. Survey No. 211, 

1903, pp. 65-66. (Kansas.) 

Feet. 

Garrison. formation. ..... 120 

Cottonwood limestone. 6 

Eskridge shales ......... 40 

Neva limestone ........ 10 

Elmdale formation ..... 130 

Americus limestone. . . . 5 

Admire shales. . . . . . . . . 40 

Emporia limestone .... 10 

Olpe shales ..••........ 60 

Barclay limestone..... 7 

Burlingame shales ....• 120 

Howard limestone. . • • • 7 

Severy shales...... . . . . 75 

Hartford limestone ..... 25 

Calhoun shales ......... 60 

Deer Creek limestone .. 25 

Tecumseh shales ....... 75 

Lecompton limestone .. 20 

Kanwaka shales ...... 100 

Oread limestone.. . . . . 40 

LeRoy shales ........ 150 

Stanton limestone..... 30 

Lane shales ........... 100 

lola limestone.. . . . . . . 30 

Vilasshales ........... 75 

Earlton limestone..... 15 

Chanute shales ....... 200 

Drum limestone...... 30 

Cherryvale shales . . . . . 120 

Dennis limestone..... 15 

Galesburg shales ...... 100 

Hertha limestones . . . . 20 

Dudley shales ........ 150 

Parsons limestone..... 25 

Bandera shales . . . . . . . 100 

Pawnee limestone. . . . . 25 

Labette shales........ 60 

Fort Scott limestone. . 25 

Cherokee shales ....... 450 

Adams, G. I., Bull. U. S. 

Geol. Survey No. 238, 

1904, Pl. III, opp. p. 18 

and errata. (lola quadrangle, Kansas.) 

Piqua limestone. 

Vilas shale. 

Allen limestone. 

Concreto shale. 

lola limestone. 

Chanute shale. 

.lD1mnis limestone. 

r:1 ~ Galesburg shale. 

~ ~ Mound Valley lime- o "' stone. ~.§ Ladore shale. ...... Hertha limestone. 

Dudley shale. 

Parsons limestone. 

Bandera shale. 

Pawnee limestone. 

Labette shale. 

Fort Scott limestone. 

Cherokee shale. 

B :;one limestone........... Boone limestone. 

Schrader, F. C., and 

Haworth, E., Bull. U.S. 

Geol. Survey No. 296, 

1906,p. 10. (Independence quadrangle, Kansas.) 

Elgin sandstone. 

Painterhood limestone. 

Buxton formation. 

Wilson formation: 

Piqua limestone. 

Vilas shale. 

Allen limestone. 

Concreto shale. 

lola limestone. 

Chanute shale. 

Drum limestone. 

Coffeyville formation: 

Cherryvale shale. 

Denms limestone. 

Galesburg shale. 

Mound Valley limestone. 

Lad ore-Dudley shale. 

Parsons formation. 

Bandera shale. 

Pawnee limestone. 

Labette shale. 

Fort Scott limestone. 

Cherokee shale. 

Boone formation. 

Haworth, E., Kansas Un.iv. 

Geol. Survey, vol. 9, 

1908, Pl. III. (Kansas.) 

Wabaunsee stage: 

Garrison formation. 

Cottonwood limestone. 

Eskridge shales. 

Neva limestone. 

Elmdale formation. 

Americus limestone. 

Admire formation. 

Emporia limestone. 

Willard shales. 

Burlingame limestone. 

Shawnee stage: 

Scranton shales. 

Howard limestone. 

Severy shales. 

Topeka limestone. 

Calhoun shales. 

Deer Creek limestone. 

Tecumseh shales. 

Lecompton limestone. 

Kanwaka shales. 

Douglas stage: 

Oread limestone. 

Lawrence shales. 

Kickapoo limestone. 

Le Roy shales. 

Pottawatomie stage: 

Stanton limestone. 

Vilas shales. 

Allen. limestone. 

Lane shales. 

lola limestone. 

Chanute shales. 

Drum limestone. 

Cherryvale shales. 

Denms limestone. 

Galesburg shales. 

Mound Valley limestone. 

Ladore shales. 

Bethany limestone. 

Marmaton stage: 

Pleasanton shales. 

Coffeyville limestone. 

Walnut shales. 

Altamont limestone. 

Bandera shales. 

Pawnee limestone. 

Labette shales. 

Fort Scott limestone. 

Cherokee shales. 
jferent parts .of the western interior coal field. 

I 

rickness given ·Ji feet.] 

ukansas 

II 

coal field. 

!: ----.-----li1

, .. ------------1 "Indian Territory coal field" 

·teven- (Drake, N. F., Proc. Am. Philos. 

York Collier,A.J.,andothcrs, Bull. U.S. Soc., vol. 36, 1897, pp. 388-407). 

_P_· _s1_._ Geol. Lurvey No. 326,1907, p.12. 

Feet. 

0-3,900 

... 100 

500-600 

. 0-100 

• 0-500 

. 0-500 

. 0-500 

10(}-400 

J0-2,500 

50-150 

500-600 

500-600 

Savan~ formation. Feet . Paris s 1

ale •................. 700 I 

I 

FortS 1"thformation .... : .... 400 

Spadra ~hale . . . . . . . . . . . . 350-500 

Hartsh,rne coal. 

Hartsh 'rne sandstone. . . . 100-300 . I . 

Atoka prmation :. . . . 1,500-5,000 

I 

l 

II 

i 

I 

' 

Feet. 

Poteau group.............. 2,000 

Cavaniol group .... · . . . . . . . 5,500 

Grady coal. 

Lower Coal Meru~ures ...... 17,000 

v between Penns*lvanian and Mississippian as given in the reports cited. · 

Southern Oklahoma. 

1-----------------...,..--------------,-----c~----------l Arbuckle Mountains, Oklahoma (Taff, J. 

Taff, J. A., Coalgate folio (No. 74), Geol. 

Atlas U. S., 1901. 

Feet. 

Seminole conglomerate .. _ ...... -. . 50+ 

Holdenville shale .................. 260 

Wewoka formation . . . . . . . . . . . . . . . . 700 

Wetumka shale . . . . . . . . . . . . . . . . . . . 120 

Calvin sandstone .............. 145-240 

Senora formation. . . . . . . . . . . . . . 14(}-485 

Stuart shale ...•................. 90-280 

Thurman sandstone . . . . . . . . . . . . 80-260 

Boggy shale . . . • . . . . . . . . . . . . 2,000-2,600 

Savanna sandstone . . . . . . . . . . . . 1,000 

Taff, J. A., Atoka folio (No. 79), 

Geol. Atlas U. S., 1902. 

Feet. 

Boggy shale. . . . . . . . . . . . . . . 800+ 

Savanna sandstone ..... 750-1,100 

McAll!Ster shale ............. 1,800, 2,000 McAlester shale ..... : 1,150-1,500 

Atoka coal, probably Hartshorne coal. Atoka coal, at same horizon as Hartshorne coal. 

Hartshorne sandstone .............. 150 Hartshorne sandstone .... 150-200 

Atoka formation ...........•..... 3,;1.00 Atoka formation . . . . . . . . . . . 3,200 

Wapanucka limestone .............. 100 Wapanucka limestone ... 100-150 

Taff, J. A., Tishomingo folio (No. 

98), Geol. Atlas U.S., 1903. 

A., Prof. Paper U.S. Geol. Survey, No. 

31, 1904, pp. 34-35). 

Feet. 

Sanctstone, shale, and coaL 10,000-11,000 

Wapanucka limestone. 

Franks conglomerate ... 300-500+ Franks conglomerate. 

Unconformity 

-Glenn ~ormation •••.. 1,000-3,000-

Western Arkansas (Purdue, A. 

H., The slates of Arkansas; 

Bull. Geol. Survey Arkansas, 1909, p. 48). 

Atoka sandstone.... . . . 6,000 

Jackfork sandstone ..... 6,600 

Stanley shale. 

Abbreviated Kansas section 

(Haworth, E., and others, 

Kansas University, Geol. Survey, vol. 3, 1898, p. 94). 

Cottonwood formation. 

Wabauns.ee formation. 

Shawnee formation. 

Douglas formation. 

Pottawatomie formation. 

Marmaton formation. 

Cherokee shales. 

1 

.,_ _____ .Unconformity------.;----Unconformity----;-------------

Caney shale (Carboniferous and 

probably Devonian) ............ 800+ 

Caney shale.: ............. 1, 500 Caney "shale .. _ ........••..• 1,500 Caney shale. 

Woodford chert (Devonian and 

Carbonifel'ous). 

Syeamqre limestone ........ 0-160 

Woodford chert (Devonian and 

Carboniferous). 

I 

) 

t 

Woodford chert. 

Boone chert. 
PENNSYLVANIAN. 459 

as the Ouachita area as a whole has a width of about 70 miles, it is evident that the total shortening has been very considerable. The rocks appear to have been pushed from south to north. 

Stratigraphically the upper part of the series of rocks is similar to the series in the Arkansas 

River valley, from the Caney shale upward. The lower part of the series differs from the 

adjoining rocks in the Arkansas area in the presence of a great thickness of sandstone and shale 

resting on the Ordovician rocks and belonging beneath the Caney shale a,nd apparently above the 

·woodford chert. These have been estimated by Ulrich to have a thickness of 14,000 feet on 

Little Missouri River. This series was named by Taff 806 the Standley (now spelled Stanley) 

shale and Jackfork sandstone. At the west is the Caney shale, supposed to be later than the 

Jackfork. To the east the Caney shale has not been recog11-ized, and the Atoka formation 

overlies the Jackfork. In the Atoka folio Taff gives the Jacldork sandstone and the Stanley 

shale a thickness of 5,000 feet each. Branner 98 gave these beds, including the Atoka, a thickness 

of 18,480 feet in the area west of Little Rock. Purdue;655a in a paper on the Arkansas slate area, 

gives the thickness of the Atoka, Jackfork, and Stanley as 6,000, 6,600, and 6,000 feet, respectively, or a total of 18,600 feet, in substantial agreement with' the earlier estimate of Branner. 

The age of the Jackfork sandstone and Stanley shale is still a matter of some doubt. They 

are either late Nlississippian or early Pennsylvanian, possibly passing from the one over into the 

other. 

The proper correlation of the Caney shale is also a matter of some douot. In folios 74, 79, 

and 98 of the Geologic Atlas of the United States the Caney was assigned first to the "Carboniferous and probably Devonian" and later, on the evidence of fossils which were thought by 

Girty to indicate a late Mississippian age, to the Mississippian. Two years later (1905) Girty 3630 

placed the Caney in the Pennsylvanian because, inasmuch as it was underlain by 10,000 feet of 

Carboniferous strata, there was reasonable doubt of its Nlississippian age. In 1909 the same 

author 366 published a description of the Caney fauna in which, after citing the inconclusive 

paleobotanic evidence, he summed up the faunal evidence as follows: 

"The faunal evidence furnished by the Caney is much more extensive than that of the 

fossil plants referred to above. The Caney fauna has a facies widely different from that of the 

typical upper Mississippian faunas, and it would be difficult to determine its position in the 

time scale were it not that it is closely related to certain faunas in Arkansas which contain 

more of the typical upper Mississippian species and which have long been regarded as belonging 

to that period. \Vhen I originally determined the Caney as nco-Mississippian, I did so because 

its fauna was so closely allied with that of the Moorefield shale of Arkansas. If, upon returning 

to the subject with a presentation of one side of the evidence upon which this conclusion was 

based, it were possible to say that the preliminary opinion had been erroneous, it would afford 

me real satisfaction as opening a way out of the present difficulties. But a more detailed study 

of the one fauna and a hasty review of the other have only added to the weight of the evidence. 

A large number, and those in many cases the most striking and typical of the Caney species, occur 

also in the Moorefield shale. * * * 

"The ordinc1,ry inference from these facts, one which I should draw without hesitation were 

it not for the bearing of the plant evidence found in the Standley, is that the Caney and the 

Moorefield-Fayetteville beds were contemporaneous in a geologic sense.a But this, it may 

be urged, does not necessarily entail the Mississippian age of the Caney without carrying 

the inquiry one stage further. Careful consideration has been given the hypothesis that the 

Moorefield-Fayetteville beds may be not Mississippian but Pottsville in age. While some circumstances lend a color of probability to such an hypothesis, the negative evidence seems at 

present to warrant its rejection. 

"If, then, the Caney correlates with the Moorefield, if the ·Moorefield is of Mississippian 

age, if the Caney rests on the Jackfork sandstone, and if the evidence furnished by the Standley 

flora halts between upper Mississippian and Pottsville, the conclusion that the Standley is 

upper Mississippian and that the sedimentation of that period was peculiar and excessive in the ---------------~---------------------------

a The White Pine shale of Nevada, which is also a black shale formation, likewise contains a fauna similar in 

many respects to that of the Caney. 
460 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Ouachita region seems to involve the fewest inconsistencies. This conclusion 1s tentative 

and unsatisfactory but seems to accord best 'vith the evidence known to me. Future discoveries 

may prove it wrong." 

The Pennsylvanian shales, limestones, and sandstones of Oklahoma have been 

studied by Gould and his associates/75 who have classified them as follows: 

The rocks in the area under discussion consist of a thickness of from 10,000 to 12,000 feet 

of sediments of Pennsylvanian age extending from the Mississippian to the Permian. In general these rocks consist of alternating layers of shale and sandstone. The shales greatly predominate, making up approximately three-fourths or possibly nine-tenths of the entire thickness 

of the strata. In the northern part of the State there is a number of ledges of limestone, but 

even in this region shales constitute more than three-fourths of the strata, the remainder being 

about equally divided between sandstone and limestone. Farther north, in east-central Kansas, 

the limestone ledges are not only more numerous (no fewer than twenty distinct ledges having 

been recognized) but they are thicker, while sandstones make up a relatively small per cent of the 

entire series. 

In Kansas it has been noted that on passing from the center of the State to the Oklahoma 

line the various limestone ledges frequently thin out and some of them disappear before the line 

is reached. Others pass for several miles into Oklahoma before disappearing, but, except in 

eastern Kay County, comparatively few limestones reach the Arkansas River. Of the half 

dozen or more which persist south of that stream only one ledge, so far as known, exceeds 10 

feet in thickness. 

It has also been found that as the limestones thin out to the south and finally disappear, 

sandstones often come in, usually either just above or just below the limestone. In other cases 

the ledges become more arenaceous to the south, until finally the ledge which was a limestone 

has become a sandstone. It frequently happens, also, that additional sandstone ledges come 

in, first as mere arenaceous bands in the shales, then as thin lenses which thicken to the south 

and finally become ledges of hard sandstone 20 to 50 feet thick, which resist erosion and give 

rise to pronounced escarpments. In a number of instances, however, the thinning out of the 

limestone ledges is to the north. This fact is particularly well exemplified in the case of several 

ltmestone ledges in the region about Bartlesville, and between that city and Arkansas River 

above Tulsa. Here at least two heavy ledges of limestone disappear to the north. Many of the 

ledges, both limestone and sandstone, when traced for any considerable distance are found to be 

local lenses. The general rule throughout the area is, however, that limestones "finger out" 

to the south and sandstones to the north, while the intervening shales coalesce. 

Another factor which complicates the difficulty of the situation is the gradual thickening 

of the entire series to the south, particularly near their base. For instance, the basal group, 

to be hereinafter described as the Muskogee group, is about 450 feet thick at the KansasOklahoma line, but in the region north of the Choctaw fault, in the eastern part of the State, the 

same group has an approximate thickness of 9,000 feet. Part of the apparent thickening in 

this instance is probably caused by unconformity by overlap on the Mississippian, but much of it 

is doubtless caused by normal thickening of strata southward. The thickening of other groups 

from north to south, while not so conspicuous as in the case mentioned, is nevertheless often 

obvious. 

From what has preceded, it will be evident that the problem d the proper division and 

correlation of the various beds is, in the absence of paleontological data, at best difficult. In 

rare cases only may any single ledge of either limestone or sandstone be traced from Kansas 

line southward for any considerable distance. As has been stated, many of the sandstones 

and a few of the limestones are lenticular and have but a comparatively limited areal extent. 

These conditions have already given rise to considerable confusion in folio and economic mapping, and it is feared that, as this work progresses, the complications may be augmented. It 

is with the hope of lessening the possibility of confusion in the application of stratigraphic terms 

and the needless multiplication of names in the future that this article has been prepared. 
PENNSYLVANIAN. 461 

PROPOSED SOLUTION. 

The authors are convinced that the problem of tho future division and correlation of the 

various beds may be greatly simplified by dividing all the rocks in the region into a few general 

groups, the limits of which may be demarked by certain conspicuous ledges of limestone and 

sandstone which extend southward from the Kansas line. After studying the region in considerable detail, it has been found that there arc at least four of these ledges of sufficient importance and linear extent along the line of outcrop to serve as adequate group markers, which 

groups must, of course, be confirmed by paleontological evidence. Beginning on the east, these 

ledges are as follows: 

1. The Claremore formation, the approximate equivalent of the Fort Scott limestone of 

Kansas, which is correlated with the Calvin sandstone in the Coalgate folio. 

2. The Lenapah limestone, which lies at the approximate horizon of the Upper Parsons 

or Coffeyville limestone of Kansas. 

3. The Pawhuska formation, which is believed to be the equivalent of the Deer Creek and 

Hartford limestones of Kansas. 

4. The Wreford limestone, which, south of the Cimarron River, gives way to the Payne 

sandstone. 

From the study of the map it will be seen that these four formations trend approximately 

parallel northeast and southwest, from the Kansas line toward the region of the Arbuckle Mountains. The southern extension of none of them has been definitely located, but it is believed that 

accurate field studies will fix the position of each formation. 

PROPOSED GROUPS. 

It is therefore proposed to demark the limits of four general groups of the Pennsylvanian 

rocks of eastern Oklahoma as follows: 

1. The Muskogee group, including all the rocks from the base of the Pennsylvanian series 

to the base of the Claremore formation. The name proposed is that of Muskogee County, which 

lies near the center of the area occupied by the group. 

2. The Tulsa group, ineluding everything from the base of the Claremore formation to the 

base of the Lenapah limestone. The name is from Tulsa County, in the eastern part of which 

the rocks of the group are well exposed. 

3. The Sapulpa group, including the rocks between the base of the Lenapah limestone and 

the base of the Pawhuska formation. The name is from Sapulpa, the county seat of Creek 

County. 

4. The Ralston group, including everything from the base of the Pawhuska to the base of 

the Wreford, which has usually been considered the base of the Permian. The name here 

proposed is from the town of Ralston, in northern Pawnee County. 

In proposing these groups the authors do not wish to be understood as attempting to fix 

definitely the nomenclature of the region. The purpose is merely to provide a comprehensive 

yet simple scheme of classification which may be followed in future mapping. The classification 

is made entirely upon stratigraphic and lithologic data. 

DESCRIPTION OF GROUPS. 

MUSKOGEE GROUP. 

Area.-The Muskogee group includes a series of rocks, chiefly sandstones and shales, extending from an unconformity at the top of the Mississippian series on the east to the base of the 

Claremore formation a and its approximate southern equivalent, the Calvin sandstone, on the 

west. In the northern part of the State it includes the approximate area occupied by the southern continuation of the Cherokee shales of Kansas; in the southern extension it includes the 

great coal region of Oklahoma. The area included in this group in Oklahoma is bounded on 

a This formation includes the Fort Scott limestone of Kansas and some of the upper part of the Cherokee shale. 

At the south boundary of the Claremore quadrangle as much as 100 feet of the Cherokee is included.-C. D. Smith, 

comment on manuscript. 
462 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

the north by the Kansas line, and on the northeast by the areas occupied by Mississippian rocks. 

On the cast the Arkansas line is the boundary. The Choctaw fault, the Cretaceous overlap in 

Atoka County, and the Arbuckle Mountains demark the southern limit. It includes all or part 

of the following counties in Oklahoma: Ottawa, Craig, Mayes, Rogers, Wagoner, Cherokee, 

Okmulgee, Muskogee, Sequoyah, Le Flore, Haskell, Mcintosh, Okfuskee, Hughes, Latimer, 

Pittsburg, Coal, Pontotoc, and Atoka. 

Stratigraphy.-Near the Kansas line, in which State the name Cherokee shales has been 

applied to the rocks of the group, the approximate thickness of the strata is 450 feet and consists largely of shales, with local beds of sandstone and limestone and several thin beds of coal. 

The following section from Pryor Creek to Claremore made by Messrs. Ohern and Wolf will give 

a fairly comprehensive idea of the stratigraphy at that place. 

Section frorn Pryor Creek to Claremore. 

Feet. 

14. Shale with a few interbedded sandstones.............................................. 135 

13. Massive medium-grained sandstone ............................................. _ .... _ 17 

12. Shaly sandstone ............................... _ .................. _ ........... _. __ .__ 3 

11. Argillaceous, heavily bedded fossiliferous limestone .. _.................................. 2~ 

10. Bluish shale._ ...................................................................... : 35 

9. Carbonaceous shale capped by 6 inches of ferruginous siliceous limestone................. 3 

8. Gray fine-grained sandstone........................................................... 7 

7. Arenaceous shale. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 

6. Alternating shales and sandstones...................................................... 70 

5. Argillaceous fossiliferous limestone.................................................... 8 

4. Massive medium-grained sandstone................................................... 37 

3. Shaly sandstone..................................................................... 8 

2. Massive medium-grained sandstone ............................. _..................... 14 

1. Bluish shale, weathering to light yellow, and a few interstratified sandstones.............. 550 

960 

In the Muskogee folio Mr. Taff describes two formations, the Boggy and the Winslow, the 

latter being the equivalent of the Hartshorne, McAlester, and Savanna formations as exposed 

in the coal fields farther south. The formations above the Boggy have not been described in 

Muskogee, Okmulgee, and Mcintosh counties. 

The stratigraphy of the southern part of the Muskogee group is better understood than 

that of any other part of the Pennsylvanian series in Oklahoma. Numerous reports and folios 

bearing upon the subject, chiefly from the pen of Mr. Taff, whose work in the region continued 

almost without interruption from 1895 to 1908, have given us a very comprehensive idea of the 

stratigraphy, structure, and economic resources of the coal fields of the State. The general 

sequence of the formations with their approximate thickness as shown in Coal and Hughes 

counties is here given, the oldest below: 

Feet. 

Calvin sandstones .............................................................. _ . . . . . . . . . 200 

Senora formation ................................................................... _..... 500 

Stuart shale.: ... _ ................................................ _ ......... _ ..... __ ... _. 2:50 

Thurman sandstone ......................................................... _ ... __ .... _.. 200 

Boggy shale ................................................................ __ ........... 2,000 

Savanna sandstone ....................................................... _ ........ __ ... _ _ 1,200 

McAlester shaloo. _ ................................................................. _ ... _ 2,000 

Hartshorne sandstone..................................................................... 200 

Atoka formation........................................................ . . . . . . . . . . . . . . . . . 3,000 

!),550 

This entire series of strata is coal bearing. In Arkansas beds of considerable thickness 

occur in the Atoka formation, but in Oklahoma these beds are usually thin and inconspicuous. 

The McAlester formation cont.ains four beds of workable coal and a number which may eventually be developed. The Savanna contains at least three and the Boggy formation two workable 

beds. Several occur in the higher formations of the series, particularly one in the upper part 

of the Senora which is mined at Henryetta, Schulter, and Morris. In the southeastern part of 

the area occupied by rocks of the Muskogee group the strata have been extensively folded and 
PENNSYLVANIAN. 463 

in certain places fault3d. A series of anticlines and synclines have their axes extending 

northeast-southwest. 

It is not the purpose in this connection to discuss the problem of the cause of the thickening 

of the various beds of the Muskogee group to the south, or what amounts to the same thing, 

the thinning of the beds to the north. It has usually been assumed that the change in the 

thickness is due largely to unconformity by overlap. While in the present state of our knowledge, particularly in the absence of complete paleontological evidence, it would be extremely 

unwise to say that this cause did not obtain, at least in part, still in the light of accumulating 

evidence it seems very probable that we must look elsewhere for reasons to account for a 

considerable part of the southern thickening of the beus. 

TULSA GROUP. 

Area.-This group includes all the rocks lying between the base of the Calvin-Claremore 

formation and the base of the ledge which in Kansas has been known as the Upper Parsons 

or Coffeyville limestone, but which in a paper by Ohern, now in press, is designated as the 

Lenapah limestone. The rocks of the group outcrop on the surface as a band, averaging 20 

miles in width, and extending from the Kansas line south to the region of the Arbuckle Mountains. The Lenapah limestone a has not been certainly located ·south of the North Canadian 

River, although there is reason for believing that it wili eventually be correlated with a limestone in the upper part of the Holdenville formation, which outcrops not far from the town 

of Holdenville, in Hughes County, and which probably extends nearly to Ada. The rocks of 

the Tulsa group occupy all or part of the following counties: Craig, Nowata, Rogers, Tulsa, 

Wagoner, Okmulgee, Okfuskee, Coal, Hughes, and Pontotoc. 

Stratigraphy.-The rocks of the Tulsa group, as exposed in the northern part of the State, 

include formations which in Kansas have been described under the names Fort Scott limestone, 

La bette shales, Pawnee limestone, Bandera shales, Altamont limestone, and "\V alnut shales. 

The combined thickness of these rocks at the Kansas line is about 250 feet; farther south this 

thickness is much greater. 

The Fort Scott limestone, known to the oil drillers of Kansas and Oklahoma as the Oswego 

lime, was first described in Kansas, where it consists typically of two limestone members and 

an intervening shale member. Ohern, however, finds that in northern Oklahoma a third 

limestone member comes in below the Fort Scott of Kansas and persists at least as far south as 

the Arkansas River. For this formation, consisting of three limestones with two intervening 

shale beds, each containing coal, in a paper now in press, he is proposing to use the name 

Claremore. 

The Labette shales, named and described in Kansas, extend from the Kansas line southward across Oklahoma, finally, on the disappearance of the higher limestones, coalescing with 

other shales. The Pawnee and Altamont (Lower Parsons) limestone, which at the Kansas 

line are separated by the Bandera shales, come together in southern Nowata County and form 

a single ledge, the Oologah, the "Big lime'' of the drillers. The ledge extends southward, 

crosses the Arkansas River near Broken Arrow, and disappears in the vicinity of the Concharty 

Mountains. 

From the Arkansas River south the rocks of the Tulsa group consist of sandstones and 

shales with an occasional lentil of limestone. In the Coalgate folio Mr. Taff has described 

the following formations beginning with the Calvin: 

Feet. 

Seminole conglomerate __________________________________ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 150 

Holden ville shale _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 250 

Wewoka formation_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 700 

Wetumpka shale._____________________________________ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 120 

Calvin san aston e.________________________________________________________________________ 200 

If, in the above section, the Tulsa ~roup includes the Calvin, Wetumpka, and 'Vewoka 

formations, and probably 200 feet or more of the Holdenville formation, this would indicate ~hat 

a This formation is not recognizable south of \Vatora, in Nowata County, Okla. The Dawson coal, however, 

which occupies practically the same horizon, extends southward beyond Kansas River.-C. D. Smith, comment on 

manuscript. 
464 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA, 

the rocks of the group as exposed in the region south of the Canadian River reach a thickness 

of approximately 1,200 feet. SAPULPA GROUP. 

Area.-The rocks which constitute the Sapulpa group include everything from the base 

of the Lenapah limestone to the base of the Pawhuska formation (as that term was used by 

J. P. Smith) as these formations are exposed in the northern part of the State. Neither the 

Lenapah nor the Pawhuska has been definitely located south of the North Canadian River 

and for that reason the southern limits of the group can not now be accurately demarkcd. 

The area included in the group averages 35 miles in width, extending from the Kansas 

line south to the vicinity of the Arbuckle :Mountains. It includes all or part of ~ owata, Washington, Osage, -Pawnee, Creek, Tulsa, Okmulgee, Payne, Lincoln, Okfuskee, Pottawatomie, 

Seminole, Pontotoc, and probably McClain, Garvin, and Murray counties. 

Stratigraphy.-Included in the Sapulpa group in Oklahoma are rocks which in Kansas 

have been described under the following formation names: Coffeyville limestone, Pleasanton 

shales, Bethany Falls limestone, Ladore shales, Mound Valley limestone, Galesburg shales, 

Dennis limestone, Cherryvale shales, Drum limestone, Chanute shales, lola limestone, Lane 

shales, Stanton limestone, LeRoy shales, Kickapoo limestone, Lawrence shales, Oread limestone, 

Kanwaka shales. 

The approximate combined thickness of these rocks as exposed in southern Kansas is 1,000 

feet. In Oklahoma the thickness of the group gradually increases until at the Arkansas River 

it is probably 1,200 feet or more. 

So far as known, with the exception of the Lenapah, none of the limestone ledges exposed 

in Kansas persist as far south as the Arkansas River. The Drum limestone splits near the 

Kansas line, and the lower member, which Ohern calls the Hogshocter, disappears some 20 

miles north of Tulsa. The upper member of the Drum disappears soon after crossing the 

State line. Two limestone lentils, the Dewey and Avant, come in not far from Bartlesville 

and persist beyond the Arkansas River, where they also disappear. As the limestones disappear 

near the Kansas line, sandstones become prominent and farther south increase in thickness 

until they make up a considerable part of the rocks of the group, although, as in other parts 

of the general region occupied by Pennsylvanian deposits, shales are the predominating rock. 

No accurate section has ever been made across the southern part of the region occupied 

by rocks of the Sapulpa group, and for that reason it is impossible to do more than to approximate the thickness of the group along the Canadian River, but it is probable that in this region 

it is somewhere between 1,500 and 2,000 feet. 

In its southwestern extension the Sapulpa group passes into and includes the eastern part 

of the Oklahoma Red beds, being part of the so-called Chandler beds. * * * 

RALSTON GROUP. 

Area.-The Ralston group includes the rocks in the upper part of the Pennsylvanian series, 

beginning at the base of the Pawhuska formation and extending to the base of the Wreford 

limestone and its southern continuation, the Payne sandstone, which has usually been considered the base of the Permian.a The group is exposed as a band averaging 30 miles in width 

extending parallel to the other groups described in this paper, from the Kansas line south toward 

the Arbuckle Mountains. 

Neither the Pawhuska formation nor the Payne sandstone has been definitely located as 

far south as the North Canadian River and consequently the limits of the southern part of the 

Ralston group, which is exposed in Lincoln, Oklahoma, Pottawatomie, Cleveland, McClain, 

and Garvin counties, can not be accurately demarked. In the northern part of the State this 

group is exposed in Osage, Kay, Pawnee, Payne, and Lincoln counties. 

Stratigraphy.-The equivalents of the following formations in Kansas, the combined 

thickness of which is approximately 800 feet, are included in the Ralston group as the latter 

is exposed in northern Oklahoma: Lecompton limestone, Tecumseh shales, Deer Creek limea Beede now considers the Elmdale as the provisional base of the Permian. 
PENNSYLVANIAN. 465 

stone, Calhoun shales, Topeka limestone, Severy shales, Howard limestone, Scranton shales, 

Burlingame limestone, Willard shales, Emporia limestone, Admire shales, Americus limestone, 

Elmdale formation, Neva limestone, Eskridge shales, Cottonwood limestone, Florena shales, 

Neosho formation. 

These formations are exposed along the Flint Hills in southern Kansas, but near the Oklahoma line most of the limestone members thin out and disappear, while sandstones come in 

and thicken to the south. No accurate section across the group has been made in Oklahoma, 

but it is probable that the group does not thicken to the south as rapidly as do the groups 

heretofore described. In fact, there is some evidence which indicates that in Lincoln, Pottawatomie, and Cleveland counties the rocks representing the southern extension of the Ralston 

group are not so thick as they are farther north. 

In southern Pawnee and northern Payne counties the color of the rocks in the Ralston 

group changes and becomes a deep brick-red and so continues to the southern limits. This 

area includes the greater part of the so-called Chandler beds mentioned above. 

HIGHER ROCKS. 

Above the Ralston group the sequence of limestones and shales with occasional sandstones 

continues uninterruptedly for several hundred feet. The Kansas geologists have described 

these rocks under the following names, the oldest below: 

Wellington shales. 

Marion formation. 

Winfield limestone. 

Doyle shales. 

Fort Riley limestone. 

Florence flint. 

Matfield shales. 

Wreford limestone. 

The limestones contain much flint, which, being resistant, withstands erosion, g1vmg 

rise to a series of pronounced escarpments, which, in southern Kansas, constitute the Flint 

Hills. The rocks of the Marion are less resistant and form few pronounced escarpments. The 

Wellington shales are all soft rocks and weather into a flat plain. 

In Oklahoma, all these formations pass into the Red beds along the line indicated on the 

map. Several of the limestones, particularly the Wreford, the Florence, and the Fort Riley, 

extend several miles into the Red beds before finally losing their color and merging with red 

sandstones and shales. 

This peculiarity of relations is represented on the map in Kay and adjoining counties, 

where there is exposed an area of non-red Permian rocks, triangular in shape, bounded by 

the Kansas line, the Wreford limestone, and the eastern margin of the Red beds. 

The Pennsylvanian terranes of Iowa are described as the Missouri and Des 

Moines groups. Smith 753 has the following note on the Missouri: 

The Missouri of southwestern Iowa is composed of shales, limestones, and limited amounts 

of sandstone. The shales, which comprise much the greater part of the strata, are generally 

calcareous-so much so tllat even those in immediate contact with the coals effervesce readily 

with acid. The limestones occur in layers from an inch or two in thickness to ledges 20 feet 

thick. Usually the limestones are highly fossiliferous. In all the Coal Measures exposures 

of Adams, Montgomery, Page, and Taylor counties not a single sandstone is to be found. Deep 

drillings also show a total absence of sandstone in the Missouri in these counties. 

The Des Moines is described by Lees 531 as follows: 

The beds of the Des Moines stage are usually divided in a broad way into three general 

divisions. These, as indicated in the section, are, from above downward, the Pleasanton, the 

Appanoose, with its equivalent beds farther northwest, and the Cherokee. Of these three the 

lower division, the Cherokee, is the most important, in Iowa as well as in Missouri and Kansas. 

* * * It will be seen from the section that shales are the preponderating element in this 

48011°--12----30 
466 INDEX '1'0 THE STRATIGRAPHY OF NORTH AMERICAo 

division, while sandstones are also quite important. Coal beds and fire clays play a minor 

part, although economically the former are exceedingly important. All these beds are wonderfully irregular in distribution. They thicken and thin with amazing rapidity and grade 

from one to another horizontally as well as vertically. * * * The beds of coal vary in thickness up to 7 feet, with an average of about 4 feet. Their areal extent is usually not above 

a few hundred acres and many of them are much below this maximum. Many of them lie 

in depressions in the St. Louis limestone, and their limits are determined by this formation. 

The Cherokee beds form the eastern line of outcrop of the Lower Coal Measures from Van 

Buren to Webster counties. Their maximum thickness will probably average 500 feet, although 

over most of their area they are considerably thinner. * * * 

The Appanoose formation is typically developed in Appanoose and neighboring counties, 

as well as across the State line in Missouri. The beds composing this division are much more 

regular in structure than those underlying them, and the coals, while thinner, are more continuous and dependable. The most important of these coals is the Mystic seam, which underlies 

an area of about 1,500 square miles in the two States. * * * 

Accompanying this coal seam are several relatively thin limestone beds marked, like the 

coal, by great continuity and uniformity of character. Some shales and a conglomerate are 

also present. * * * 

The upper division of the Des Moines, the Pleasanton, is not of great importance in Iowa. 

While in Kansas these beds attain a thickness of about 200 feet and carry some important 

coal seams, they thin to the north and in Iowa are characteristically barren of coal and scarcely 

distinguishable from the next lower division. They thin rapidly in Guthrie County and 

probably do not extend beyond the northern limit of this county. 

It is not to be understood that these three divisions are sharply set off one from the other, 

for they are for the most part conformable each to each, and hence there are no clear dividing 

lines. The divisions are made because each phase exhibits certain well-marked features which 

set it off in a general way from the others. 

J-K 15-16. EASTERN INTERIOR COAL REGION. 

The following statement on the eastern interior coal region was prepared for 

this volume by G. H. Ashley: 

The Pennsylvanian of the eastern interior coal region consists of about 2,000 feet of rocks, 

occupying a simple structural basin that includes most of Illinois, southwestern Indiana, and 

part of western Kentucky, an area of about 50,000 square miles. The rocks consist of shales, 

sandstones, coals, clays, and limestones, usually in members of small thickness, many times 

repeated. Soft shales and sandstones predominate. Coals up to 13 feet thick, usually underlain by stigmaria! clays, occur at about forty horizons, and limestones up to 20 feet thick are 

fully as numerous. 

The basin, while mainly structural, was enlarged and extended by pre-Pennsylvanian erosion 

in the underlying Carboniferous rocks. To the north especially erosion removed successively 

the several Mississippian formations, and in part of northern Illinois the Pennsylvanian rests 

on Ordovician rocks.346 

The oldest Pennsylvanian rocks of the region correspond in age with the Pottsville of the 

Appalachian region and are confined to the central and southeastern parts of the basin in 

southern Illinois 900 and probably southern Indiana and the eastern part of this region in Kentucky, this basin probably having been for a time connected with the northern Appalachian 

field. These rocks are predominatingly sandy, with shale, clay, thin coals, and in many places 

conglomerate. The sandstone is massive and resistant and now forms a belt of rugged hills 

along the whole eastern and southern margin. The oldest of these rocks are probably of lower 

Pottsville age, and the top not older than Sharon, the basal member of the upper Pottsville. 

Unconformably above these in southern Indiana are 100 feet or less of rocks of later Pottsville 

age, more shaly in character and containing workable coals in small basins, as well as valuable 
PENNSYLVANIAN. 467 

clays. These rocks may have had an original extent equal· to or greater than the underlying 

sandstones. 

Above the rocks just described are about 300 feet of rocks approximately corresponding 

in age with the Allegheny formation of Pennsylvania. These rocks are predominantly shaly. 

They contain at least sixteen coal beds, several of which are widely workable, forming the productive part of the Pennsylvanian. The coals are usually underlain by clays and overlain by 

shales. .Most of the shales are either light colored and contain fragments of land plants or a 

marine or brackish-water fauna, or they are black and highly bituminous and contain an opensea fauna. As a rule marine limestones closely overlie the roof shales, and at several horizons 

such limestones underlie the underclays. The beds of this part of the section are very persistent, 

many coal beds, clays, and limestones having been traced more or less continuously over large 

parts of the field. The geology of the basin has been described in several State and Federal 

reports.a 

The coals have been variously designated by numbers and letters. In Illinois the coals 

of this part of the series have been called Nos. 2 to 7. In Indiana they are known as coals 

II to VII, some of which correspond to coals of similar number in Illinois, and for the smaller 

intermediate coals small letters have been added. Numerals also have been used in Kentucky, 

where 9, 11, and 12 correspond to V, VI, and VII of Indiana and Illinois. 40• 268 • 052 

The upper 1,000 feet of the series is characterized by more limestones, some of them widely 

persistent, by thinner and fewer coals, and by more sandstone. 

In the early reports the Pennsylvanian of this basin was divided into (1) Basal sandstone or 

Millstone grit, (2) Lower or Productive Coal .Measures, and (3) Upper or Barren Coal Measures, 951 

the line between the "Upper Coal .Measures" and the "Lower Coal Measures" being drawn at a 

limestone variously known in the reports of different regions as the Shoal Creek, Curlew, Carthage Cn, Carlinville, New Haven. and Somerville limestone, local names being also given to 

some of the other more persistent limestones and sandstones of the coal measures. In 1898 the 

present writer 36 divided the coal measures of Indiana into "divisions" on the basis of the principal coals, an arrangement continued in his supplemental revised report published in 1909.40 

The sandstone of Pottsville age in Indiana had previously been designated the .Mansfield sandstone by Hopkins. 462 In 1900 the series was divided by the writer 37 into the Mansfield, 

Wabash, and Merom groups, corresponding respectively to (1) the Mansfield sandstone and 

associated rocks; (2) the rocks between the nonconformities above the Mansfield sandstone 

and below the Merom sandstone; and (:3) the .Merom sandstone and overlying rocks. In 1902 

and 1903, for cartographic purposes, Fuller and Ashley 347 • 348 divided the series above coal VII 

into the Wabash, Inglefield, Ditney, Somerville, and .Millersburg formations, and the upper 

part of the series, below coal VII, into the Petersburg and Brazil formations. 

In view of the probable difficulty of carrying the bounding lines of these formations over 

all the basin, the names have not been retained in recent work. Since 1906 White and Weller 

have done considerable paleontologic work in all parts of the basin, in addition to the stratigraphic work in Illinois by DeWolf and in Indiana by the writer. (See references above.) As 

a result, the Pennsylvanian of the eastern interior basin has been divided into three formations, 

the first, or Pottsville, extending from the bottom of the series up to the top of the underclay 

of coal II in Indiana and coal No. 2 in Illinois; the second, or Carbondale formation, extending from that horizon up to and including coal No. 6; and the third, or McLeansboro formation, from the top of coal No. 6 to the top of the series. It is possible that future work may 

show that the limestone which in the Illinois State reports has been called Shoal .Creek limestone can be traced over all of the basin, and that it may again be used as a line of division 

between the upper and lower parts of the McLeansboro formation. Coal V of Indiana, which 

appears to be the same as coal No. 5 of Illinois and coal 9 of Kentucky, may be developed 

throughout most of the coal field. If future tracing shows that it is, it may possibly be used 

a Illinois State Geol. Survey, vols. 1-7, 1866-1890; Bulls. 3, 4, 6, 8, 1906. Indiana Dept. Geol. and Nat. Hist., 

vols. 1-14; vol. 23, pp. 1-1573, containing a detailed report; vol. 33, containing a revised supplement to the report in 

vol. 23. Kentucky Geol. Survey, vols.1-4; vols. 1-5, new series; reprints A, C, D; Bulls. 3, 4. U.S. Geol. Survey, 

folios 67, 84, 105, Geol. Atlas U.S.; Twenty-second Ann. Rept., pt. 3, 1902, pp. 272-303. 
468 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

as the dividing line between two formations i1i the middle member. Again, future work may 

show it possible to divide the beds of Pottsville age into at least two formations, the upper 

one including the more shaly portion unconformably overlying the Mansfield sandstone. 

The table opposite shows the subdivi~ions of the Pennsylvanian that have been made in 

the several fields of this region, with their known or probable correlations. 

K 16. MICHIGAN. 

The Michigan section of the Penn"lylvanian is discussed by Lane 519 in a paper 

recently published. It comprises the Parma sandstone and Saginaw formation and 

is wholly of Pottsville age. 

The Parma is a sandstone with small white pebbles of the size of split peas. 

According to Lane it may be regarded as the basal shore phase which was deposited 

earlier in the deeper and later in the marginal portions of the basin. It is thus synchronous in part with the Saginaw. The thickness assigned to the Parma in a well 

at Saginaw is 60 feet. 

The Saginaw formation is described by Lane 510h as a succession of white shales 

or sandstones, black shales and coal, and blue shales, with a few thin bands of blackband iron ore and nodules of siderite containing zinc blende and iron pyrites. Limestones with marine fossils occur but are rare. Lingula carbonaria or mytiloides is 

found in the black shales. It appears to mark the horizon of the Upper Verne coal, 

which in places lies close above the Lower Verne coal, separated from it by a limestone. 

The flora of the Verne coals, which Lane lists, is assigned by David White to the 

horizon of the Mercer coal, or upper Pottsville. Nothing younger than Pottsville is 

known, and it is probable that the earliest Pottsville is not represented in Michigan, 

even in the center of the basin. 

To the account of the coal measures for this volume G. H. Ashley has contributed 

the following notes regarding Michigan: 

The Pennsylvanian of Michigan is nearly everywhere deeply buried beneath glacial drift, so 

that our knowledge of its thickness, distribution, and stratigraphy depends almost altogether on 

drillings. Including the Parma sandstone at the base, it covers an area of about 11,000 square 

miles, of which the coal-bearing part of the series covers possibly 6,500 square miles.516a This 

area is situated in about the center of the Southern Peninsula. The structure is that of a "very 

flat, gentle synclinorium, whose longest axis is perhaps from northeast to southwest. This is 

modified by minor undulations." 515a The Pennsylvanian has a thickness of 700 feet or more, 

including the Parma sandstone at the base. This sandstone is about 100 feet thick, though 

measurements up to 145 feet are repcited and measurements below 100 feet are common. In 

places the sandstone is absent.171 

For the rocks above the Parma sandstone the name Saginaw formation has been used.514 

This formation consists of sandstone and shale, with coal, clay, limestone, and iron carbonate in 

nodules or thin beds. Coal occurs at twelve or more horizons. 171" The coals appear to lie on 

floors of irregular surface, varying in thickness to correspond-that is, the coal is thicker in the 

low places or" swamps" and thinner in the higher places. Many of the low places have the shape 

of a trough. The coals may range in thickness up to 5 feet; most of the merchantable coal is less 

than 4 feet, and some less than 2 feet. Under the coal is usually clay, and over it black shale, with 

blue shale and limestone above. Cannel coal or cannel-like coal is associated with many of the 

Michigan coal beds, usually at the top of the bed. Sandstones are abundant in the Saginaw formation, many of them as thick beds of white sandstone, in places grading into red at the top.515 

They do not occur at any constant horizon in the formation. 

A comparison of the dip of the higher members of the Saginaw with that of the underlying 

strata and the stratigraphic sections in various parts of the basin indicates that at least part of 
White, David, corre- lations with Appalachian field. See 

paper quoted in 

next column. 

Post-Allegheny. 

Allegheny. 

Ashley, G. H., Supplementary report on the coal 

deposits of Indiana: Thirty-third Ann. Rept. 

Dept. Geology and Nat. Res. Indiana, 1909. 

Feet. 

Rocks, with Aldrich and Friend ville coals. . . . 200 

Parker coal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 

Interval. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 

Ashley, G. H., The coal 

deposits of Indiana : Twenty-third Ann. 

Rept. Dept. Geology 

and Nat. Res. Indiana, 1899. 

Merom sandstone............................ 40 Merom sandstone. 

Interval with coals VIII a and b............. 90 Division VIII. 

Coal VIII (0--4) .. _...... •. . . . . . . . . . . . . . . . . . 1 Coal VIII. 

Interval................................... 70 

Coal VII (0-6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 

Division VII. 

Coal VII. 

Interval (6 inches to 60 feet).................. 40 Division VI. 

Coal VI (0-9) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Coal VI. 

Interval, coals V a and b. . . . . . . . . . . . . . . . . . . . 70 Division V. 

Coal V(4-11)................................ 7 Coal V. 

Interval, coal IV a .......................... 130 

Coal IV (2-7)................................ 5 

Interval, coals III a and b. . . . . . . . . . . . . . . . . . . 70 

Coal III (0-11)..... ........................ 6 

Interval, coals II a to II e ................... 100 

Division IV. 

Coal IV (VII). 

Division III. 

Coal III (VI). 

Coal II (0--4). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Coal VI. 

···················· ----------·--------1 

Pottsville. 

Interval (6 inches to 40 feet)................. 20 

Minshall coal (0-6).......................... 4 Coal V. 

Interval................................... 30 

Upper Block coal. . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Coal IV. 

Interval. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 

Lower Block coal... . . . . . . . . . . . . . . . . . . . . . . . . . 3 Coal III. 

Mansfield sandstone, etc. . . . . . . . . . . . . . . . . . . . 100 

Canneltoncoal(0-5) ......................... 3 

Sandstones, shales, and coals ............. : . . 50 

(Division I). 

Coal II (I). 

Coal I. 

48011°-12. (To face page 468.) 

Correlations in eastern interior coal region. 

[By G. II. Ashley.] 

Fuller, M. L., and Ashley, G. H., Ditney folio (No. 84), Geol. Atlas U. S., 

U. S. Geol. Survey, 1902. Fuller, M. 

L., and Qlapp, F. G., Patoka folio (No. 

105), idem, 1904. 

Wabash formation. 

Inglefield formation. 

Ditney formation. 

Somerville formation. 

Cox, Collett, and others, earlier 

usage of Indiana Geol. Survey. 

Merom sandstone. 

-----------------------------I CoalN. 

Millersburg formation. 

Millersburg coal. 

Millersburg coal (lower bench). 

Petersburg formation. 

Petersburg coal. 

Brazil formation. 

Survant coal ? 

Rock Creek coal ? 

Holland coal ? 

Coal M (N, L, K, etc.). 

Coal L (N, M, K, etc.). 

Coal K (L, M, Y, ek). 

(Coal N, etc.). 

(Coal L, etc.). 

Coal L. 

Coal K. 

Coal I. 

Coal F. 

Conglomerate series or Millstone grit. 

Coal A. 

Kentucky Geol. Survey 

reports. 

Illinois Geol. Survey reports. 

Feet. 

Ashley, G. H., The 

eastern interior 

coal field: Twentysecond Ann. Rept. 

U.S. Geol. Survey, 

pt. 3, 1902, p. 273. 

Sandstone,shale, Merom group. 

and thin coals. 450 

Upper Coal 

Measures. 

Coall8. 

Shoal Creek or 1-------------1 Carlinville 

Carthage limestone. 

Coals 17-13. 

Anvil Rock sandstone. 

Coal12 or A. 

Coalll or B. 

Coal B or D. 

? Coal 7 or F? 

? Coal 6 or Fa ? 

? Coal 5 or Fb ? 

? Coal4 or G? 

? Curlew limestone ? 

Conglomerate measures. Coal 1 B or L or Main 

Nolan. 

limestone. 

Lower Coal 

Measures. 

Interval. . 180-270 

Coal 7. 

Coal 6. 

Coal 5. 

Coal4? 

Coal3? 

Coal2? 

Battery Rock coals. 

Caseyville conglomerate. 

Wabash group. 

Mansfield group. 

Bull. Illinois Geol. Survey No. 16, 1910, p. 

181; No. 17, 1912, p. 

74. 

McLeansboro formation. 

Carbondale formation 

(includes coal No. 6 or Herrin coal at top 

and coal No. 2 or Murphysboro coal at 

base). 

Pottsville formation. 
PENNSYLVA~IAN. 469 

the earlier Pennsylvanian was confined to the center of the basin, the strata of later age extending 

outward by overlap to the present limits of the coal field and beyond.515 

The Pennsylvanian of Michigan appears to be all of Pottsville age.516 From a study of the 

plants David White has suggested that the Verne coals, near the top of the series, may come at 

about the horizon of the Mercer coals of Pennsylvania. The basal sandstone, or Parma sandstone, 

may be of the age of the Sharon conglomerate member of the Pottsville of Ohio and Pennsylvania. 

K 19. RHODE ISLAND AND EASTERN MASSACHUSETTS. 

The Carboniferous strata in Rhode Island occupy the Narragansett Basin, 

which has been described by Shaler, Woodworth, and Foerste. From fossil plants 

obtained in these beds Lesquereux considered them equivalent to beds of the upper 

Carboniferous (Pennsylvanian) m Pennsylvania. Woodworth 732 tabulates the 

strata as follows: 

Group. 

Dighton(l,000-

1,500 feet). 

Rhode Island 

Coal Meas- ures (10,000 

feet). 

Wamsutta 

(l ,000 feet). 

Tabular view of the strata in the Narragansett Basin. 

Northern field. Southern field. 

-----~----,----------+---~---,-------- Remarks. 

Local areas. Local areas. I ~-C-h_a_ra_c_.t_er_s_. -!~--------­

Rocky \Y oods 

conglomerate. 

Seekonk con- glomerate. 

Westville 

shales and 

Seekonk 

sandstones. 

Tenmile River 

beds. 

Mansfield beds. 

Cranston beds. 

Soc kanasset 

sands tones. 

Pawtucket 

shales. 

W am-

{

Slates 

sutta :~~~es. Attleboro 

sandstone. 

Wamsutta con- glomerates. 

Characters. 

Coarse quartzite and 

granitic pebble con- glomerates, with finer 

conglomerates and 

sandstone. 

Alternations of fine and 

medium quartz, 

quartzite and granitic 

pebble conglomerates, 

with pebbly sandstones, sandstones 

(graywacke), shales, 

and coal beds, becoming metamorphic 

southward. Colors, 

black, blue, green, 

gray, locally red. 

Odontopteris flora 

and insect beds. 

Beds of quartz, quartzite, felsites, felsite 

breccias, and felsite 

conglomerates, sandstones, arkose, and 

shales. Colors, red, 

locally brown, and 

green. Calamites. 

I 

Purgatory 

conglomerate. 

i Aq uidneck 

shales of 

Dr.Foerste. 

Kingstown 

series of Dr. 

Foerste. 

Coarse quart;r,-

ite pebbles, 

usually much 

elongated 

and indented. 

Mainly shales 

with coal 

beds. 

Mainly sandstones and 

conglomerates with 

coal shales; 

usually. metamorphic. 

Probably though not cer- tainly identical in all 

parts of the field, lying 

in synclines above the 

Coal Measures. 

Both the Aquidneck and 

Kingstown series of 

Dr. Foerste, when 

traced northward, appear to form equivalent sections beneath 

the Dighton group, one on the eastern, the 

other on the western 

side of Narragansett 

Bay, and both extend 

downward to the basal 

beds in this typical area. 

The vVamsutta beds are not traceable south of 

Providence; probably 

represented by lower 

strata of Dr. Foerste's 

Kingstown series. In 

the vicinity of Pawtucket the Coal Meas- ures underlie the Wamsutta. 

~--1---1 Millers River ~~Q-u-a-rt-.z-c--o-n_g_lo_m_e-ra_t_e-s.-~ -B-a-sa_l_b_e_d_s_.~ _Q_u_a-rt-z-os_e_c-on---- ;s_s_e_n-ti_a_ll_y--s -i -m-1-. 1-a-r 

Pond ville (100 

feet). con g I om- Coarse, white, granitic I g I om e rates products of decayed 

erates, arkose I waste or arkose. and arkose. granitic land surface 

beds. in all parts of basin. 

U f . \Videspread erosion interval, representing all of Silurian and Devonian time and probably upper neon orm1ty. Cambrian. 

Pre-Car bonif- erous. 

Broad expo~ures of granitite intruded into 

lower and middle Cambrian and preCambrian sediments. 

Same as in northern field. 

----· -------------~------------------

Pre-Carboniferous strata 

not definitely determined; Cambrian or pre..Cambrian. 
470 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Sayles and La Forge 705 have published a note on faceted and striated pebbles 

from the Roxbury conglomerate, from which they conclude that the conglomerate 

is in part at least of glacial origin. They say: 

The tillite occupies the upper portion of what has been known as the Roxbury conglomerate and at Squantum is from 500 to 600 feet thiek and is overlain by about 60 feet of stratified 

conglomerate, sandstone, and interbedded slate, which make the top of the Roxbury and 

form a transition to the overlying Cambridge slate. Tho possible glacial origin of the Roxbury 

conglomerate has been suggested by the late N. S. Shaler and others, but these are the first 

known discoveries in that formation of definite evidence of glacial action or of the existence 

of glacially deposited beds. 

They conclude that the Roxbury conglomerate and Cambridge slate are 

probably of Permian age. 

The Boston Basin of eastern Massachusetts contains terranes which have 

been assigned to the Carboniferous, in part on physical and in part on paleontologic 

evidence, and which consist of arkose, conglomerate, sandstone, and slate. The 

rocks were described by Crosby 182 and have been made the subject of a very detailed 

study by Mansfield, 570 who has given special attention to the origin and distinguishing characteristics of the conglomerates. He describes them under the headings "Roxbury series," "Norfolk Basin series," "Narragansett Basin series," and 

"Harvard conglomerate." These distinctions are areal rather than stratigraphic 

and are made because in the absence of fossils and under the conditions of occurrence exact stratigraphic correlation among the small areas of outcrop was not 

practicable. Mansfield 570a concludes thatThe evidence adduced in the preceding paragraphs as to origin is largely negative and 

unsatisfactory. The bedding and texture of the sediments, though attaining a fair degree 

of regularity, do not display these features in so high a degree of development as might be 

expected in true marine strata. The apparent gradation upward from coarse to fine texture 

in the Boston Basin, suggestive of marine transgression, is offset by the occurrence in the 

Narragansett Basin of a gradation in the opposite direction, suggestive of nonmarine deposition. The fossils thus far found in the Narragansett and Norfolk basins are indicative of 

nonmarine rather than of marine origin. Similar evidence is borne by the irregularities of 

bedding and of texture. The lithological similarity of the Roxbury conglomerate to the 

rocks of the Norfolk and Narragansett basins makes it probable that all are of like origin 

and that the entire Carboniferous series of this region is nonmarine. More than one process, 

however, was concerned in the formation of the series. The more regular and even-bedded 

portions are suggestive of quiet fluviatile or lacustrine origin, while the more irregular and 

tumultuous portions of the deposit indicate torrent action. The great quantity of large pebbles 

of relatively fresh granite and the abundance of feldspathic material in the sandstones and 

in the matrices of the conglomerates suggest that much material was furnished to the streams 

of that time by glaciers of which no direct evidence now exists. 

In describing the geology of Worcester and vicinity, Perry and Emerson, 634 

after giving an account of local occurrences, summarize the facts relating to the 

Carboniferous as follows: 

Starting at Worcester, as a center, we find first and uppermost the Worcester phyllite. 

This rock underlies the central part of the city and may be traced southwesterly and northeasterly across the State. It presents varying stages of metamorphism, from a true argillite 

to a well-defined mica schist, and contains in different places minerals resulting from metamorphism, as garnets, chiastolite, graphite, staurolite, and anthracite. The laminre of the 

phyllite are frequently high.J.y crumpled, producing folds almost infinitesimal in size and infinite 
PENNSYLVANIAN. 471 

in number. In some places these fine folds have been so compressed and flattened that they 

constitute the beginning of folia of a now structure across the old. In one place, also, this 

rock exhibits the development of a new structure by the rotation in sections of the laminre 

between fault planes. 

That the phyllite is really uppermost in position with reference to the other rocks of 

sedimentary origin found in Worcester is shown by its superposition in anticlines. In deciding 

as to its ·position in the geologic series-that is, its age-we rely on the specimens of Lepidodendron acuminatum found at the so-called coal mine here in Worcester, and we assign it to the 

Carboniferous. It probably belongs to an early part of that period. 

On the east this phyllite blends into a rusty, fibrolitic, graphitic mica schist which is found 

in small, detached patches within the Bolton gneiss area. These are probably remnants, 

indicating the former greater extension of this schist formation. 

The second and lower formation in Worcester is a micaceous quartzite of a brownishgray color. This is associated with the phyllite in the latter's extent across the State and 

occurs in bands east and west, sometimes also in the midst, of the phyllite. 

Because of the close relationship which these two formations bear to each other, the 

micaceous quartzite is also assigned to the Carboniferous period. They have been folded 

together on a large scale in the Oakdale-Millstone Hill anticline, the phyllite above and the 

quartzite beneath, and they have been crumpled together on a small scale in many places, 

as may be seen in tho rocks of the deep cuts of the Boston & Albany and Boston & Maine 

railroads here in Worcester. These two formations appear, as far as can be seen in the midst 

of such severe folding, to be conformable. 

Like the phyllite, the quartzite also shows the development of a new or secondary structure 

across the old or original structure; and in the case of the rock of Wigwam Hill the new structure 

was formed by the compression of small folds in the micaceous part of the quartzite, so that 

these compressed folds have become the folia of the schist as it is at the present time. This 

quartzite is in a few places conglomeratic, and the pebbles show deformation by pressure, being 

more or less flattened in the plane of the laminre. 

Penetrating the Carboniferous phyllite and quartzite are granite bosses, of which Millstone 

Hill is typical. These granites are later than the Carboniferous. That of Millstone Hill contains inclusions of both the phyllite and quartzite. The structure of the adjoining Carboniferous quartzite wraps around this granite, sometimes with the original bedding and sometimes 

across it. The rocks in the immediate vicinity of the granite have been greatly shattered and 

now frequently appear as breccias or made up of small angular blocks cemented together by 

fine quartz veins. Even the phyllite included in the granite is brecciated, indicating that the 

pressure was not excessive when this was included in the molten granite, hence that this granite 

did not solidify at a very great depth beneath the surface of the, earth. * * * 

The Carboniferous quartzite, traced to the east, blends into a coarser-grained, more highly 

metamorphosed quartzose mica schist, frequently containing alternating hornblendic bands. 

Between the laminre of this schist there has been forced, by parallel injection, much coarse 

granite. This schist and granite afford many minerals, both original and secondary, as enumerated in the study of the quarry near Quinsigamond. The alternation of schist and granite 

is very gneissoid in appearance and often presents a close resemblance to a metamorphic 

conglomerate. From this appearance, and from the fact that it extends through the town 

of Bolton and there contains the well-known limestone mineral locality, this phase of the 

Carboniferous quartzite is called the Bolton gneiss. 

It is upon this Bolton gneiss that are spread the patches of ~he rusty, fibrolitic, graphitic 

mica schist phase of the Carboniferous phyllite already referred to as indicating the former 

greater extension of that formation. 

Within this Bolton gneiss are also small areas of crystalline limestone in the towns of Boxboro, Bolton, Northboro, Millbury, and Webster. These crystalline limestones abound in minerals formed during the metamorphism, and the Bolton and Boxboro limestones have long 

been noted for the scapolite and other minerals they afford. * * * 
472 lNDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The Bolton gneiss may be traced northeasterly, easterly and southeasterly from Worcester 

and is found underlying Oxford, Millbury, Grafton, Shrewsbury, Northboro, Berlin, Bolton, 

Boxboro, and other towns to the northeast. It is seen from this that the Bolton gneiss makes 

up a large portion of the eastern part of the plateau of central Massachusetts. * * * 

It is well for us, therefore, in tracing the Bolton gneiss, to follow a southeasterly direction 

through the town of Millbury into the town of Sutton. * * * In this direction we find 

that the Bolton gneiss extends from Worcester through Millbury and the northwestern part of 

Sutton; then as we go still farther to the southwest, in the vicinity of West Sutton, we become 

aware that the rock beneath is quite different. This change from one formation to another 

may be nicely seen about three-fourths of a mile southwest of West Sutton. 

This more ancient formation consists, generally, of a light-colored, nearly white, finely 

grained, sugary quartzite, which is at times actinolitic. It constitutes a comparatively narrow 

band extending through the towns of Webster, Oxford, Sutton, Grafton, and Westboro and 

is called the Westboro quartzite. As it dips beneath the Bolton gneiss on the western side of 

a large anticline, the quartzite is considered older than the gneiss. In appearance this quartzite 

reminds one of the Cambrian quartzite of western Massachusetts, though there is nothing in 

this eastern· rock to definitely fix its geological age. * * * 

We have now briefly considered the rocks from Worcester to the eastern and southeastern 

border of the plateau of central Massachusetts, bringing out the relation of each to the succeeding one, as far as we can. Let us next start from Worcester, and, in like manner, trace 

the rocks westerly. Passing over the phyllite, which is found underlying the central part of 

Worcester and which has already been considered, we find in the western part of the city the 

Carboniferous micaceous quartzite, identical with that found east and in the midst of the Carboniferous phyllite. This arrangement of these two formations is due to folding and subsequent 

erosion, by which the lower one is revealed alongside of the upper. 

On following this micaceous quartzite in the extreme western part of Worcester the rock 

becomes coarser in grain and abounds in parallelly injected granite, giving an appearance that 

frequently simulates a metamorphic conglomerate. This western and more highly metamorphosed phase of the Carboniferous quartzite has been called the Paxton schist, from its occurrence in that town, just as the similar gneissoid extension of the same quartzite on the east is 

called the Bolton gneiss. The Paxton schist is less gneissoid than the Bolton gneiss because 

of a smaller proportion of injected granite. 

Lying above the Paxton schist, as is shown by its upper position in an anticline in the 

northwestern part of Worcester, is a rusty, graphitic, fibrolitic mica schist identical with the 

rusty, graphitic, fibrolitic mica schist found in patches within the area of the Bolton gneiss. 

This rusty schist has been crumpled into almost innumerable folds, both large and small, and 

contains much injected granite. Lying as it does above the Paxton schist, which is a more 

highly metamorphosed phase of the Carboniferous quartzite, this rusty schist bears the same 

relation to the Paxton schist that the Worcester phyllite bears to the Carboniferous quartzite; 

also on the east side of Worcester there is, in a small area, a transition from the phyllite into 

a like rusty, graphitic, fibrolitic schist; this rusty schist in the western part of Worcester, called 

the Brimfield schist, is then, a more highly metamorphosed or more coarsely crystallized phase 

of the Worcester phyllite and belongs to the Carboniferous period. This Brimfield schist, in 

addition to making up large areas, also occurs in limited patches within broad areas of the 

Paxton schist. These patches probably indicate the former extension of this upper Brimfield 

schist and are remnants that have escaped in the profound erosion by which the rock surface 

of this plateau has been formed. These two rocks, the Paxton and Brimfield schists, together 

with their included eruptives, make up the plateau of central Massachusetts westerly from 

Worcester to the boundary as already defined. 

But these Carboniferous rocks have even a greater extension to the south and north and 

may be traced far into Connecticut on the one hand and beyond the Massachusetts boundary 

into New Hampshire on the other. 
PENNSYLVANIAN. 473 

L 19-20. NEW BRUNSWICK. 

The Carboniferous of New Brunswick comprises Mississippian, Pennsylvanian, 

and Permian strata. Bailey has summed up the general facts in an article, quoted 

at some length in Chapter VIII, from which the following 45b regarding the "Coal 

Measures'' is taken: 

The contrast between the above-described rocks [lower Carboniferous] and those of the 

coal formation is, in the central counties, usually very marked, the bright-red color so characteristic of the one being replaced by an equally characteristic gray color in the other, while at 

the same time the strata cease to be calcareous. The basal beds of the coal formation are especially noticeable as being very light colored and almost entirely made up of well-rounded pebbles 

of white quartz. Conglomerates which are somewhat less coarse occur also higher in the series, 

but with them are beds of coarse sandstone and thinner beds of shale, with, in places, thin 

seams of coal. Upon the shore of the Baie des Chaleurs about 50 feet of fine shales, gray, 

green, or red in color, with limestone nodules, extend for several miles in the coastal cliffs about 

New Brandon, resting upon gray sandstones, but over the larger part of the central coal field 

the absence of fine sediments is a noticeable and unpromising feature. 

Though gray is the prevailing color in the rocks of the coal formation, it is necessary to 

add that it is not unfrequently replaced by a dark purple tint. Occasionally also the beds are 

reddish, but where this is the case it is always a question whether the rocks so colored are not 

of the next division, viz, the newer coal formation or Permo-Carboniferous. 

The only data available with regard to the thickness of the coal formation in the Central 

Basin is that to be derived from borings, particulars of which will be given later. The greatest 

attained at Grand Lake was 400 feet. At Dunsinane, in Kings County, a depth of 1,200 feet 

was reached, apparently all in the Carboniferous. In Westmoreland County north of Moncton 

a depth of 700 feet has been reached in apparently Carboniferous strata. In Albert, where the 

strata are more highly tilted, thA Carboniferous rocks alternate, by displacement, with lower 

Carboniferous beds, but never attain any considerable thickness. 
Color, light gray. 

Symbol, 11. 

CHAPTER XI. 

PERl\HAN. 

Distribution: Southwestern United States; West Virginia, Ohio, and Pennsylvania; New 

Brunswick and Nova Scotia. Elsewhere mapped with "Carboniferous undivided." (See 

fig. 13.) 

Content: Permian limestone and red beds, Kansas to Texas; Permian red beds, New Mexico; 

Opeche and Minnekahta formations, Black Hills; Dunkard group of the northern Appalachians; red and gray sandstones and subjacent New Glasgow conglomerate of New 

Brunswick, Nova Scotia, and Prince Edward Island. Includes some Triassic red beds in 

mappmg. 

Permian areas. 

Page. 

H-I 13-14 ...................... Texas and New .Mexico.................................................... 474 

I-J 12-13 ..................... Utah, Colorado, Arizona, and New Mexico (mapped in general with Triassic 

and Jurassic) . . . .. . . . . . .. . . .. . . .. . .. .. .. .. . . .. . .. . . .. . . . . . . . . . . . .. .. . . . . 4 79 

I-J 14 ........................ Kansas and Oklahoma.................................................... 486 

J-K 13 ......................... Southern Wyoming and northern Colorado (mapped with the Triassic and 

Jurassic)............................................................... 490 

J-K 17 ......................... Pennsylvania, \Yest Virginia, and Ohio..................................... 492 

K 10 ........................... Klamath Mountains, California (not mapped)............................... 494 

K 12-1:3 ........................ \\"yoming, northern Colorado, and Utah (mapped in general with the Triassic 

and Jurassic). .. .. . .. . .. .. . .. . .. .. .. .. . .. . .. .. . .. . . . . . . . . . . . . . . . . . . . . . . . 494 

K-L 13 ........................ Black Hills, South Dakota................................................. 495 

K15 ........................... Iowa ..................................................................... 497 

L 20 .......................... New Brunswick, NoYa Scotia, and Prince Edward Island.................... 497 

H-1 13-14. TEXAS AND NEW MEXICO. 

The strata assigned to the Permian in trans-Pecos Texas and adjacent parts 

of New Mexico comprise the Delaware Mountain formation, the Capitan limestone, the overlying unnamed sandstones and limestones on the eastern flanks of 

the Guadalupe Mountains, and the red beds of Pecos Valley, which include the 

Castile gypsum and the Rustler dolomite. These formations outcrop in the areas 

colored as Carboniferous undivided, and Richardson's descriptions of them are 

given in Chapter VIII (p. 360). 

The Delaware Mountain formation and the Capitan limestone contain a unique 

fauna, named the Guadalupian, which has been described in detail by Girty, 364,

367 

who tentatively assigned it to the Permian. (Seep. 359, Chapter VIII.) 

The Capitan limestone, the uppermost formation known to contain the Guadalupian fauna, on the eastern flanks of the Guadalupe Mountains, southwest of Carlsbad, N. Mex., is overlain by a few thousand feet of sandstone and limestone to 

which formation names have not yet been given. These in turn are overlain by 

the red beds of Pecos Valley, which, according to Richardson 67oaconsist of a group of varicolored sandstone and shale, red predominating, interstratified with 

beds of magnesian limestone and gypsum. In detailed study it is desirable to divide these rocks 

474 
FIGURE 13.-Sketch map showing the distribution of Permian rocks that are separately represented on the geologic 

map of North America and the key to references in the text. 

475 
4 76 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

into a number of formations of comparatively limited extent similar to the Castile gypsum 

and the Rustler formation, which when traced for a number of miles beyond the area in which 

they were named lose their individual character and become difficult to recognize as such. The 

formations of the red-bed group are characteristically lenticular. * * * 

The red beds of Pecos Valley are delimited above, as Cummins and Drake determined a 

number of years ago, by an erosional unconformity, which separates them from the overlying 

Dockum formation, of Triassic age. The lower limit of the red beds of Pecos Valley, defined 

as the lowest occurrence of either red strata or of gypsum, is variable and is not a definite horizon but rather forms a zigzag line extending diagonally across the strike of the rocks. * * * 

[In central New Mexico] almost the entire Carboniferous section is composed of red beds. 

Fossils are of rare occurrence in these red rocks, although at a few localities shells have 

been obtained from the interbedded limestones, and fragments of fossil wood also have 

been found. Dr. Girty does not feel justified in saying anything definite as to the age of the 

fossils collected from the red beds either by Mr. Fisher or by myself. These include Schizodus 

ovatus and Pleurophorus aff. subcostatus from 7 miles northwest of Roswell, N. Mex., and a 

Schizodus having the general shape of S. harei, and a form suggesting by its shape a small 

Myalina from the Rustler Hills, El Paso County, Tex. Nevertheless the stratigraphy indicates 

that the red beds of the Pecos Valley are to be correlated with part of the Permian red beds 

of Oklahoma and northwest Texas, for they were connected by tracing around the "northern 

border of the Staked Plains, by W. F. Cummins in 1891. * * * Cummins's work has been 

confirmed by C. N. Gould, who has mapped the Greer and Quartermaster formations, which are 

part of the Permian red beds of Texas and Oklahoma, across several counties in the panhandle 

of Texas, and along the Canadian River as far as the Texas-New Mexico boundary. 

This stratigraphic correlation is in agreement with paleontologic data recently obtained 

by Dr. J. \V. Beede, * * * who found fossils in a limestone in the red beds south of Lakewood, N. Mex., which he correlates with the Whitehorse-Quartermaster fauna. 

The Permian of northern Texas is continuous with that of Oklahoma in area 

and stratigraphy. It comprises red beds, which grade southward into blue clays 

and limestones, just as the red beds of Oklahoma change northeastward into similar 

rocks. Cummins 198 says: 

In previous discussions of the Permian formation in Texas a I have separated the strata. 

into three divisions, naming them ·wichita, Clear Folk, and Double Mountain, the Wichita 

being the lowest in the series. In my description of the Coal Measures in Texas I separated 

the strata into five divisions, giving to the upper division the name of Albany and the one 

immediately below that the name of Cisco. * * * 

The Wichita division was described as extending southward as far as the Salt Fork of the 

Brazos River. It is represented as resting on the top of the Cisco division of the Coal Measures, 

along its entire eastern border, and as being overlain by the Clear Fork division along its entire 

western border. 

The Albany division of the Coal Measures was described as beginning on the north at the 

Salt Fork of the Brazos River and extending southward to the southern limits of the Coal Measures in the State, resting directly upon the Cisco division and overlain on the west by the Clear 

Fork division of the Permian. It will therefore be seen that the Wichita and Albany divisions 

were made to occupy the same stratigraphic position. 

At the time these divisions were first described the relationship between them could not be 

determined from the facts then in my possession. The area of the Wichita division was known 

to be Permian and had been somewhat described prior to my giving it the present designation. 

It was embraced in the area known as the "Red Beds" of Texas. In it the invertebrate fossils 

were partly those known to occur in the Upper Coal Measures, and partly those that were chara See Ann. Repts. Geol. Survey Texas, 1889 to 1892. 
PERMIAN. 477 

acteristic of the Permian in Europe. The vertebrate fossils, which had been found quite abundantly in the area, were forms peculiar to the Permian. The area was therefore assigned to the 

Permian without any hesitancy. 

The fossils that had been taken from the area assigned to the Albany division were only 

such invertebrate fossils as had been found in the Upper Coal Measures, and no vertebrate fossils 

had been found. 

Instead of the strata being composed of red clay beds and sandstones, as was the case in 

the Wichita division, they were principally limestones and yellowish and bluish clays. In view 

of these dissimilarities it was thought best to describe the two areas under different names, 

although it was thought at the time that it was more than probable that the Wichita and 

Albany divisions were but different facies of the same beds. * * * 

During my recent examinations the true stratigraphic relation between the two divisions 

has been brought out, and I can now say with absolute certainty that they are the same in 

time and belong to the Permian. 

The Wichita division is now admitted by everyone to be Permian. This conclusion is 

based chiefly on the fossils that have been taken from the area and which have been described 

and determined by different specialists. 

Prof. E. D. Cope described the vertebrate fossils collected from this division, a list of 

which was published in the second annual report of the Geological Survey of Texas. These 

fossils show the Permian age of the beds as plainly as any one kind of life can show the age 

of any formation. 

The invertebrate fossils were partly described by Dr. C. A. White, and a list of his determinations was publislwd in the second annual report of the Texas Geological Survey. The 

evidence from this source strongly corroborates the conclusion reached by a study of the vertebrates, showing the Permian age of the division. 

Part of the flora collected from the division was described by Dr. I. C. White, and the 

evidence thus obtained also corroborated the conclusion of the Permian age of the strata. 

·williston a dissents from this statement and cites Case, 131 who summed up the 

evidence as follows: 

The evidence for the Permian character of the beds rests, then, on the presence of a single 

genus, Naosaurus, common to the Permian of North America and Europe, and on the community of many very primitive characters and numerous more specialized ones, which, however, 

reach either down into the Carboniferous below or up into the Triassic above. 

Cummins continues: 

The Permian age of this division being admitted, it follows that if the Albany division is 

but a different facies of the same bed it also must be Permian. This fact has been abundantly 

shown by the stratigraphic work done during the past season by myself and party. 

In previous years I made and published complete sections, by instrumental measurement, 

across the area of the Albany and Wichita divisions at right angles with the strike, and gave 

descriptions of the different beds composing the divisions, with a partial list of the fossils collected from them. The lines of these sections were about 70 miles apart. The section across 

the Albany division began at Albany and ran thence in a northwestern direction, crossing the 

Clear Fork of the Brazos River at the mouth of Fish Creek. The section across the Wichita 

division began at a point 8 miles north of the town of Seymour and ran thence to Wichita 

Falls. 

During the past year (1894) I have traced prominent beds found in each of these divisions 

across the country between these two sections, and have found them to be continuous from one 

to the other. By this means I was enabled to see the gradual change in the beds and to understand that they were the same in time of deposition. 

a Personal communication. 
478 INDEX '1'0 THE STRATIGRAPHY OF NORTH AMERICA. 

The panhandle of Texas has been surveyed by Gould, 374 who gives the following section and description of the gypsiferous red beds and sandstones below the 

Cretaceous: · · 

System. 

Triassic. 

Carboniferous (Permian). 

Geologic formations of the Texas panhandle. 

Formation. 

~ ~ Trujillo. 

s 

;:l 

~ (.) 

- ----- ---------------

Characteristics. 

Red shales. 

Red to gray sandstone and conglomerate (upper sandstone). 

Red shales. 

Red to gray cross-bedded sandstone and conglomerate 

(middle sandstone). 

.Massive to cross-bedded sandstone (lower sandstone). 

I 

Red shales. 

1

_T_e_e_o_va-s-. ----~ Dark-red or magenta shales and soft sandstones. 

' Variegat<~d shales and soft sandstones. 

8 

'I 

----'-----------~ Red-elay. 

I 

Massive white dolomite (Alibates lentil). 

Quartermaster. Red clays. 

1---------------

Greer. 

' Massive white gypsum (Saddlehorse lentil). 

I Red shales. 

1 Massive white gypsum in ledges interstratified with red 

I shales. 

By far the greater part of these rocks are of Permian, Triassic, or Tertiary age. The Permian and Triassic rocks are generally spoken of as red beds, owing to the predominating color 

of the clay which forms a large proportion of these deposits. 

Farther east in Texas and particularly in Oklahoma the Permian red beds are well exposed 

and have been divided into five formations-the Enid, Blaine, Woodward, Greer, and Quartermaster. In the region here described only the two upper formations of the Permian red beds 

occur, and these are found in the deep canyons, where erosion has cut through the overlying 

Triassic and Tertiary formations. The Triassic red beds are exposed along the edge- of the 

Llano Estacada in Texas and New Mexico, as well as in the canyons cut by the various streams 

that rise in the southern part of the High Plains. 

The formations are described and correlated in detail in the report by Gould, 

and references to earlier work are given. 

In a recent article on the Wichita formation of northern Texas, Gordon 371 submits results of investigations made in connection with a study of the undergroundwater conditions of that area. The invertebrate fossils are discussed by Girty and 

the plant material by David White. In regard to the correlation and classification, Gordon has the following to say: 

That the limestone series of Baylor County is the equivalent of the "Albany" formation 

of the southern area is fully established by both the stratigraphic and the faunal evidence. 

The beds in the northern area, which include the limestones, shales, and sandstones of Baylor 

County and the sandstones and shales of Archer and Wichita counties, constitute the Wichita 

formation. Our investigations therefore fully support the conclusions of Cummins and Adams 

as to the equivalency of the "Albany" and Wichita formations. * * * 

The Permian age of the beds to which the name Wichita was originally applied has been 

accepted quite generally, though there are not wanting those who regard the evidence as unsatisfactory. It was based chiefly upon the vertebrate and plant remains. In the southward or 
PERMIAN. 479 

"Albany" area the beds are wholly marine and destitute of both plants and vertebrates, though 

abounding in the remains of invertebrates. The Pennsylvanian aspect of this fauna has strongly 

impressed some investigators, including the author of this paper, and doubt was entertained 

as to whether the plane of separation between the Pennsylvanian and the Permian should be 

drawn at the base or at the top of the formation. The studies of David White, Beede, and others 

have contributed much in recent years to a knowledge of the Permian in America and in the 

main support the view of the Permian age of the Wichita formation. In a recent paper Beede 

has ably discussed the Permian of Kansas, with which he correlates the "Red Beds" of Texas. 

·Cummins correlates the beds of eastern Baylor County which he regards as the top of the Wichita formation with the Fort Riley limestone of the Chase group of Kansas. * * * Tho top 

boundary of the Wichita formation was drawn by Cummins at the top of a stratum of red clay 

overlain by thin beds of limestone and blue shales at a point on the Big Wichita 4 miles west 

of the east boundary of Baylor County. However, as we have shown, beds which are undoubtedly the same as those which appear at Seymour and southward in Throckmorton County 

appear in the banks of the Big Wichita River some 8 to 10 miles west of this point. The thickness of the strata included here, which overlies Cummins's topmost beds and are here included 

with them in the Wichita formation, is estimated to be 250 to 300 feet. The whole limestone 

and shale series of Baylor County thus included as the upper division of the Wichita formation is provisionally placed at 450 to 500 feet and consists, as shown elsewhere, of limestone 

beds of varying thicknesses separated by varying but usually great thicknesses of shale. 

How much of this is to be correlated with the Fort Riley limestones can be determi~ed 

only by more detailed stratigraphic and paleontologic studies. Cummins evidently intended 

to include the lower beds only in his correlation. It may be that further studies will show 

that the overlying beds of the Winfield limestones of Kansas are represented here. 

In regard to the fauna Girty says: 

Not until recently, it seems to me, has adequate evidence been adduced either for distinguishing the Permian of Kansas and that of Texas sharply from the underlying Pennsylvanian 

or for correlating them with the Permian of Europe. C. A. White found the Wichita fauna to 

have essentially a Pennsylvanian (''Coal Measures") facies, in which, however, certain characteristic Permian ammonites occur. A similar conclusion seems to be demanded by the evidence 

of the present collections. * * * 

Mr. White finds that about 50 per cent of the Wichita flora consists of species characteristic of the Permian, while most of the remainder are known to occur in rocks regarded as of 

Permian age. If we omit the fauna of the Kansas Permian, to include which would be a sort 

ef circulus vitiosus, no condition comparable to this has been demonstrated by the invertebrate fossils and, in so far as I have seen the evidence, no such condition exists. I am, therefore, accepting the Permian age of the Kansas and Texas beds, but at present strictly on the 

paleobotanic evidence. 

David White states: 

In accordance with the paleobotanical standards of western Europe, I refer the plants of 

the Little Wichita in Texas to the lower Permian, the terranes being probably referable to the 

Chase group in Kansas. In this connection it should be observed, however, that the Artinskian 

flora of the Urals is essentially Permian, and that paleobotanists universally agree with the 

general usage of the geologists of western Europe in referring the Artinsk to the Permian. 

I-J 12-13. UTAH, COLORADO, ARIZONA, AND NEW MEXICO. 

The Permian of the Southwestern States is involved in the "Red Beds," which 

comprise Pennsylvanian, Permian, and Triassic strata variously associated in different districts. As the surveys yet made suffice to distinguish the formations of 

either age from the others in a few localities only, it is necessary in general to map 
480 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

them as a whole, and they are all included, so far as they may be present, in the 

"Red Beds," in the dark greenish-blue are.as of the map (9). 

Cross has recently divided the "Red Beds" of the plateau province in southwestern Colorado into the Cutler formation (Permian~) and Dolores fQfmation 

(Triassic). Below the Cutler occur the Rico and Hermosa formations (Pennsylvanian), whose approximate equivalents farther south, in the Rio Grande regwn, 

are "red beds" as described by Lee. 528a 

The Cutler formation is thus characterized by Cross and Howe: 193 

The Cutler formation embraces somewhat more than the lower half of the Red Beds section 

of southwestern Colorado. Its strata arc invariably red in color and include sandstone, arkose 

grit, conglomerate, shale, and limestone. The maximum observed thickness is about 1,600 feet. 

The formation seems conformable with the underlying Pennsylvanian beds, but above it 

occurs a stratigraphic break with at least local unconformity. The base of the formation is 

indicated by the Pennsylvanian fossils of the Hermosa or Rico formations and in a broad way 

by the color line. No fossils have been found in the Cutler beds. 

Great variability in lithologic constitution, both vertical and lateral, is one of the most 

striking features of the Cutler formation. The sandstones are sometimes fine grained and 

massive, but bedding is ordinarily distinct and few homogeneous beds exceed 10 or 15 feet in 

thickness. All strata are calcareous, and the finer-grained sandstones grade into calcareous 

shales and impure marls or into sandy limestones. These rocks are naturally more or less friable 

and crumbling. 

The finer-grained strata are of the strongest red color, which is due to a ferritic pigment, 

and they are also commonly characterized by abundant bronze or rusty mica, which renders 

them fissile. Clay beds are rare, as is massive limestone. Commonly the more calcareous 

strata are nodular or gnarly and grade into calcareous sandstones. Greenish and grayish tints 

are locally found in the nodular limestones and a mottling with red is common. Some of the 

nodular limestones appear to be intraformational conglomerates. 

The sandstones frequently grade into arkose grits and these into conglomerate. With 

increasing coarseness of grain the red changes to pink, and locally beds of coarse grit are gray 

or almost white. In other cases the finer matrix of grits and conglomerates is dark red. The 

cement of the strata is calcite, and most of the conglomerate and arkose beds are comparatively 

resistant to weathering and form prominent ledge outcrops on all steep slopes. 

The grit beds often reach 3.5 feet in thickness. They are variably massive, being in some 

places almost homogeneous from top to bottom, while more frequently divided by several thin 

shale or sandstone layers. Cross-bedding is almost universal. Sporadic pebbles are present in 

all grits, and with their increase the stratum becomes conglomerate. 

The sandstones are mainly quartzose, the grits contain much feldspar, mica, and small 

pebbles like the larger ones of the conglomerates. The latter contain pebbles of granite, gneiss, 

and various schists, of quartzite and limestone, of greenstone and porphyry, and many of red, 

pink, smoky, or white quartz, part of which may come from veins. 

The pebbles are in general larger near the San Juan Mount::tins. Bowlders a foot in diameter 

are occasionally present, but most pebbles are only a few inches in diameter. The relative 

abundance of different rocks among the pebbles varies according to locality. The greenstone 

schists, mctadiorite, and green porphyry are most abundant in the Unc01rpahgre Valley exposures; granites and quartzites are always prominent. 

Taking the formation as a whole, the grits and conglomerates comprise about one-third or 

less of its total thickness in the quadrangles surveyed, and they are distributed throughout the 

section. It may be assumed that as distance from the source of the pebbles increases, the formation becomes more and more a series of fine-grained sandstones and shales, with subordinate 

grits and conglomerates. 
PERMIAN. 481 

The assignment of Permian age to the Cutler formation rests on its apparent 

conformity to distinct upper Pennsylvanian strata and on its unconformity with the 

overlying Triassic. No fossils have yet been found in it. Its recognition outside 

of the San Juan district is difficult. Cross 193b presents the known facts and suggests 

the probable correlation of the Cutler with appropriate divisions of the sections 

observed by his predecessors. 

The Red Beds of the Rocky Mountain province have proved to be perhaps the most difficult 

portion of the Paleozoic and Mesozoic section to analyze and reduce to definite groups and formations. In the first place, the red color has been found unreliable as a guide in correlation. 

It extends at some places into the fossiliferous Pennsylvanian rocks and may penetrate upward 

into Jurassic beds. Fossils have been discovered in Red Bed strata in many different localities-here of Permian, there of Triassic affinities. Unfortunately the two kinds of fossil evidence 

have seldom been found in one section, affording a means of division. Triassic fossils occur in 

some places very near the top of the Red Beds and in others near their base, in proximity to 

known Pennsylvanian strata. This apparent range of Triassic fossils has been a prominent 

factor in forming what seems to be the general opinion that the larger part of the Red Beds is 

to be assigned to the Trias. 

As far as I know, no one has presented evidence of a stratigraphic break within the Red 

Beds or suggested that the conflicting evidence as to age might be explained by such a break. 

The Ouray unconformity, however, establishes for southwestern Colorado a definite line between 

Triassic and pre-Triassic portions of the Red Beds, which can be traced on a lithologic basis 

where no visible unconformity exists. From evidence which will be presented in following 

pages it seems certain that the Dolores formation may be positively recognized through its 

fossils and lithologic character in Utah and Arizona and very possibly in New Mexico. As a 

step toward a better understanding of the Red Beds I desire to make certain suggestions as to 

the correlation of the Cutler and Dolores formations with strata in other parts of Colorado, in 

Wyoming, and particularly in the plateau province of Utah, Arizona, and New Mexico. The 

discussion is based on a study of the literature, on recent published discoveries, and on unpublished information. Naturally much of the correlation suggested is tentative. 

Four principal factors have had influence in this tentative correlation: 

(a) The lithologic character of formations compared.-This is the most important on the 

whole, since it is the only one applicable in all places. 

(b) Fossil evidence.-This guide is becoming more and more important as new discoveries 

are made. Unfortunately, collectors of fossils and even paleontologists are not always alive to 

the importance of careful stratigraphic studies and accurate measurement and description of 

sections i.n the localities where fossils are ob~ained. Their work is therefore often shornof 

much of the value that should attach to it. 

(c) The influence of post- Triassic elevation and erosion.-The stratigraphic break at the base 

of the La Plata sandstone [Jurassic] is one of great magnitude throughout the western portion 

of Colorado. In. several places the La Plata is seen in angular unconformity with the entire 

Paleozoic and older Mesozoic section. It is possible that synchronous elevations, in gentle folds 

or low domes, occurred in the plateau district, but have not been recognized. 

(d) The influence of the pre-Triassic elevation and erosion.-vVhile it appears probable that 

the pre-Dolores uplift was by no means so extensive as the post-Dolores disturbance, it is plain 

that its influence must be looked for in the plateau country as well as in the Rocky Mountains. 

The type locality of the Cutler formation (Cutler Creek, Ouray quadrangle, 

Colo.) is in longitude 107° 45', latitude 38°. The plateau province stretches thence 

westward, cut by the tributaries of Grand River known as Dolores and San Juan 

48011°--12----31 
482 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

rivers and their branches. Regarding the general geologic conditions bearing on 

correlation in this region Cross says: 

The general conditions under which correlation of the San Juan formations with those of 

the plateau section must be made are as follows: Adjacent to the mountains there is a broad 

zone of gentle westward slope in which Cretaceous beds occur. The main streams flowing west 

and south cut valleys into and in some places through the Cretaceous into underlying formations. 

Nearer the canyon of the Colorado the valleys widen and broad platforms and terraces of Jurassic 

and Triassic beds appear, the Cretaceous being restricted to the divides and isolated mesas. 

The Paleozoic formations appear at first only in isolated exposures in the deeper canyons, but 

far to the southwest rise to form the broad plain called the Colorado Plateau, on the south side 

of the Grand Canyon. Thus the older the formation the greater are the gaps between districts 

of good exposures, and the greater the likelihood that in the covered tracts unsuspected complications have entered into the problem. 

Cross also describes the occurrence of Triassic and ,Jurassic strata and says: 

The heart of the plateau is about 80 miles northwest of Ouray, and Cretaceous formations 

occupy the greater part of the intervening country. The San Miguel River, however, affords a 

section extending somewhat below the Dakota sandstone for the entire distance from the Telluride quadrangle to its union with the Dolores River, and the Dolores itself penetrates locally 

through Jurassic and Triassic into Carboniferous formations. 

* * * * * * * * * 

Below the Dolores beds Spencer found coarser Red Beds, often conglomeratic, with pebbles 

3 inches or more in diameter, and several hundred feet of such strata were noted. No opportunity was found to measure a section showing the full thickness of these coarser Red Beds, but, 

as observed by Peale, they are underlain by fossiliferous Pennsylvanian Carboniferous in Sinbad 

Valley, where there is also much structural complexity obscuring the relations. 

Spencer's observations seem to show that the section of the lower Dolores Valley embraces 

strata to be correlated with the Cutler [Permian?], Dolores [Triassic], La Plata [Jurassic], and 

McElmo [Jurassic?] formations of the San Juan region. 

Peale reconnoitered southwestern Colorado in connection with the Hayden 

Survey (1875) and mapped as "upper Carboniferous" certain beds which he classed 

as "probably Permian." These presumably represent the Cutler. Cross 189b 

restudied the section in 1905 and describes the remarkable Permian (~) conglomerates in contact with and near granite outcrops on 'Vest Creek. 

vVhere the sediment was seen resting on granite, the lower layers consisted of coarse, angular gravel, scarcely bedded at all. At a distance of a few feet above the granite bedding planes 

become more distinct, through alternation of finer and coarser material aided by color differences, the finer-grained material being reddish. At 25 feet above the granite the characteristic 

alternation of grit and conglomerate began. But the distribution of pebbles and bowlders is 

very irregular, the latter are often subangular, and the whole is so little consolidated that the 

disintegrated beds seem like surface gravels. 

Cross gives a detailed section of conglomerate and grit 879 feet thick and 

continues the discussion of eorrelation as follows: 

The pebbles of the conglomerate strata of this section are principally of granite and the 

most abundant variety is the very coarse textured one with large orthoclase crystals occurring 

in the nearest exposures of the Uncompahgre Plateau. Among the pebbles are some of greenstone schist which indicate that the pre-Cambrian complex furnishing this material is similar 

to that from which the Cutler conglomerate of the San Juan was derived. Similar greenstones 

were observed in the conglomerates of Grand River valley. 

Below the measured section there may be several hundred feet of similar strata, for the 

somewhat deeper cutting of Dolores River does not reveal the base of the succession of grits 
PERMIAN. 483 

and conglomerates. The next lower formation is probably a series of gypsiferous shales and 

sandstones and the nearest locality at which such strata are known to occur is in Sinbad Valley, 

12 miles south from West Creek. A fault running near the base of the northeastern scarp 

prevents a clear determination of the relations, but the gypsiferous beds are manifestly older 

than the strata below the Dolores. These belong no doubt in the series measured on West 

Creek. Owing to complex folding and faulting * * * the extent and relation of the 

gypsum-bearing beds can not be ascertained, but they are apparently some hundreds of feet 

m thickness. 

* * * * * * * * * 

Comparing the strata known on Grand River between the Dolores base and the Pennsylvanian limestones with the Cutler formation (Permian~) of the San Juan Mountains, it is 

clear that the gypsiferous part of the series has no similar representative in the mountain district. If such beds ever existed in the San Juan region, they were removed prior to the 

deposition of the saurian conglomerate, and this does not seem at all unlikely, for gypsiferous 

beds are known in the Paleozoic red beds of northwestern Colorado, as reported by Peale. 

The grits and conglomerates of West Creek are so near their source that they differ from 

the Cutler beds in being much coarser and more strongly arkose, but the section seen on Grand 

River and Fisher Creek certainly resembles in lithologic character the Cutler beds of the 

Uncompahgre Valley below Ouray and appears to occupy the same stratigraphic position. 

The Cutler formation and the pre-Dolores red-bed strata of Gran<i River clearly correspond 

to the lower part of Powell's Shinarump group-that is, to the "Permo-Carboniferous" of the 

Wasatch and Uinta mountains, according to the nomenclature of the Fortieth Parallel Survey, 

or to the Permian of Dutton, in the Grand Canyon monograph. Fossils indicating a Permian 

or Permo-Pennsylvanian age were found by the Fortieth Parallel geologists in the Wasatch 

Mountains and by Walcott in the Kanab Valley of northern Arizona. The apparent absence 

of fossils in most localities where these beds have been examined is no doubt due to the fact 

that they are mainly continental deposits, an origin indicated by their texture. 

Concerning the section on Grand River, Cross 189a says: 

Near Moab, on the northeast side of Spanish Valley, a poorly exposed section reveals about 

250 feet of strata, mainly reddish sanely shales, between the "saurian conglomerate" [Triassic] 

and the uppermost Pennsylvanian limestone. On Grand River about 1 mile above the Moab 

ferry the "saurian conglomerate" reappears above the level of the river, and, as it rises gradually to the northeast for several miles, a larger and larger section of the pre-Dolores strata is 

exposed, but nowhere, so far as our observations go, do the Pennsylvanian beds appear, all the 

sub-Dolores section belonging to the upper (Permian?) series of the Carboniferous. This is 

itself evidence of a great break immediately below the "saurian conglomerate." That the 

break represents uplift and erosion producing angular unconformity is well illustrated on both 

sides of Grand River about 10 or 12 miles northeast of the ferry and just below the mouth of 

Castle Creek, a stream heading on the west side of the La Sal Mountains. * * * This 

unconformity * * * may be traced for about half a mile, and it was estimated that at 

1east 600 or 800 feet of beds are visibly truncated by the conglomerate in one continuous exposure. 

The occurrence of an extensive section of gypsiferous sandstones and shales beneath the Dolores 

conglomerate in Fisher Valley, on the northwest side of the La Sal Mountain, adds so much to 

the beds transgressed; and a still higher series of sandstones and conglomerates is known, so 

that, altogether, it is estimated that not less than 1,500 and possibly 2,000 feet of Permian ( ?) 

or upper unfossiliferous Pennsylvanian beds have been eroded in the locality of the section 

first mentioned, opposite Moab. 

Returning to Cross's earlier paper/93r we learn that Gane, in a trip down the 

San Juan Valley, traced the Triassic (Dolores formation) but had "no opportunity 

to study the underlying formation." 
484 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

With reference to the supposedly Permian equivalents of the Cutler formation 

in the Zuni Plateau, New Mexico (I 12), Cross derives his information from Dutton 301 

and, after describing Newberry's section of the same region, says: 

The "Saliferous sandstones" of Newberry's report Dutton divides into three formations. 

At the base is a formation 450 feet thick, mainly "sandy shales, containing gypsum and selenite 

in abundance, with here and there thin bands of limestone." At some unspecified horizon in 

this formation Dutton found "several specimens of Bakewellia and an attenuated form of 

Myalina." On this ground he correlates these beds with the Permian of the Kanab Canyon 

district, where Walcott had discovered a more extesinve fauna. "The Permian beds are distinguished for their dense and highly variegated colors-chocolate, maroon, dark brownish reds 

alternating with pale, ashy gray, or lavender colors." 

The Permian strata thus described are overlain by "a very coarse, almost conglomeratic 

sandstone," some 50 feet in thickness, which Dutton correlates unhesitatingly with the "Shinarump conglomerate" (a particular conglomerate within the Shinarump group), referring to the 

fact that it is persistent and uniform in aspect wherever it appears throughout the plateau 

country of Utah and Arizona. He does not further describe it in this report. 

Following Walcott, the conglomerate thus identified as the Shinarump in the Zuni Plateau 

is considered by Dutton as the basal stratum of the Trias. 

After discussing the Triassic of Dutton's section, Cross 193g continues: 

Beneath the Trias in the Zuni district is Dutton's Permian, lithologically a typical Red 

bed formation. That would correspond to the Cutler formation in stratigraphic position; but 

other factors enter into the problem at this point and render any definite suggestion of such a 

correlation premature. Below the Zuni Permian comes the Aubrey group, and beneath the 

Cutler occurs the Hermosa formation (ignoring the uncertain Rico beds), both Aubrey and Hermosa carrying Pennsylvanian invertebrate faunas. Dr. G. H. Girty informs me, however, that 

these faunas arc not known to have a single species in common, and the equivalence of the two 

fossiliferous formations is therefore by no means to be assumed, though their stratigraphic 

position seems to be the same .. 

In northeastern Arizona, according to Ward, 865 the Moencopie formation rests 

in marked unconformity on the underlying Paleozoic strata (Aubrey group) and 

is therefore not to be classed as upper Paleozoic (Permian). Ward therefore placed 

the Moencopie in the Triassic, but later work by Darton 246b tends to place it in 

the Permian. 

In the northwestern part of Arizona is the Kanab Plateau, traversed by Kanab 

Canyon, which leads from the north to the Grand Canyon of the Colorado. Here 

Walcott 844 determined the presence of Permian strata. He says: 

The Permian group terminates above with ripple-marked, banded reddish-brown and 

chocolate-colored arenaceous shales and sandstone. A plane of unconformity by erosion separates it from the overlying Shinarump conglomerate, which is considered as the base of the 

lowest Mesozoic group. It is undoubtedly of Triassic age, but, as yet, this has not been 

determined by paleontological evidence in the Colorado Valley. 

The chocolate arenaceous shales give way below to drab or lavender-colored arenaceous 

and gypsiferous marls and shales, that pass, midway of the group, into reddish-brown shales 

of the same general character. A thin stratum of impure limestone is intercalated in this bed 

44 feet above the summit of the lower division and 15 feet above a band of impure shaly limestone. This band of limestone is of variable thickness and character and forms the base of the 

upper division. Numerous fossils occur in it and the associated arenaceous layers. 

The summit of the lower division was slightly eroded antecedent to the deposition of the 

limestone. The upper bed is a reddish-brown gypsiferous marl that becomes more arenaceous 

below, finally passing into a sandstone that rests on the chocolate and cream-colored limestone 
PERMIAN. 485 

beneath. This has suffered extensive denudation by erosion and is now found only in patches 

from 10 to 20 feet in thickness over limited areas, the sandstone filling the spaces between. 

Recent erosion has cut channels down through each to the formation beneath, which is a member 

of the Upper Aubrey group. A slight plane of erosion with an entire change in the character 

of the rock separates the two groups. 

The Permo-Carboniferous of Mr. G. K. Gilbert a is the same as my lower division of the 

Permian. It is placed as a subdivision of the group, now that the beds above are known to be 

of Permian age. 

The stratigraphy of the section shows a group separable into two divisions, defined above 

and below by planes of unconformity by erosion and a decided change in the character of the 

beds from those of the subjacent and superjacent formations. There is no physical break in the 

beds above the Permian limestone of the upper division before the conglomerate is reached. 

This stratigraphical arrangement is sustained by the evidence of the fauna found in the limestones 

and associated arenaceous layers in the upper division. 

The genera Myalina, Schizodus, Nucula, Aviculopecten, Murchisonia, Naticopsis and 

Goniatites are represented in the lower chocolate-colored limestone. The fauna is distinct in 

specific character from that of the Carboniferous groups beneath, and more intimately related 

to that of the fossiliferous beds of the Upper Permian division. Mr. G. K. Gilbert obtained from 

this same horizon Pleurophorus, Schizodus, and Bakevellia, a group of shells, as he states, 

suggesting the Permo-Carboniferous of the Mississippi Valley.b 

Twenty-three genera represented by thirty-four species comprise the fauna of the upper 

division. Of these, the 'following have strong Paleozoic relations: Scolithus --?, Lingula 

mytiloides, Discina nitida, Orthis --?, Rhynchonella uta, Terebratula --?, Nucula, two 

species, Aviculopecten, three species, Myalina, four species, Naticopsis, two species, Pleurotomaria --?, Macrocheilus --?, Cyrtoceras --?, Goniatites --?, and Nautilus--?. 

The Permian character of the fauna is more marked by the presence of Pleurophorus, 

three species, Schizodus --?, three species of Bakevellia including B. parva, Pteria --?, 

Mytilus --?, Rissoa --?, and the still more typical Mesozoic genera Pentacrinus and 

Pileolus --?. 

The Pentacrinus plates were discovered by Mr. Edwin E. Howell below the Shinarump 

conglomerate in southwestern Utah. They belong to a species distinct from P. asteriscus of 

the Jurassic. Three species are now known to pass from the lower division to the limestone of 

the upper division. 

The Permian character of the fauna, taken with the evidence afforded by the stratigraphy, 

clearly establishes the Permian as a well-defined and distinct group in the Colorado Valley. 

It occurs at the same horizon as the Permian determined by Mr. Clarence King in northern Utah, 

western Colorado, and southern Wyoming, fully corroborating the views advanced by him of 

the age of the beds resting on the "Bellerophon bed" of the Upper Carboniferous.c 

\Valcott's section is as follows: 

Permian (855 feet): 

Plane of unconformity by erosion. 

Upper Permian (710 feet): Gypsiferous and arenaceous shales and marls, with impure shaly 

limestones at the base. 

Plane of unconformity by erosion. 

Lower Permian (145 feet): Same as upper division with more massive limestone at the base. 

Plane of unconformity by erosion. 

Upper Aubrey (835 feet): Massive cherty limestone with arenaceous gypsiferous bed passing down 

into calciferous sandrock. 

G. H. Girtya comments on the above section as follows: 

There is hardly room for doubt that Walcott's Permian is equivalent to the "PermoCarboniferous" of the Wasatch Mountains and to the Permian(?) of the section studied by 

aU. S. Geog. Surveys W. 100th Mer., vol. 3, 1875, p. 177. See also Arch. R. Marvine's report in same, p. 213. 

b Idem, p. 177. 

cU. S. Geol. Expl. 40th Par., vol. 1, pp. 245-246 and atlas. 

d Comment on manuscript. 
486 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Weeks in southeastern Idaho, the upper half of which contains the Lower Triassic faunas of 

J.P. Smith. Personally I expect to find that the lower part of the Permian(?) strata in Weeks's 

section is not separable paleontologically, as it is scarcely lithologically, from the upper part, 

all being Permian or Triassic, as the case may be. Walcott's Permian I believe to correlate 

rather with the upper than the lower part of these strata. 

I-J 14. KANSAS AND OKLAHOMA. 

The strata assigned to the Permian of Kansas are thinly interbedded limestone and ·shale of marine origin. They have been minutely distinguished and their 

study is embarrassed by the number of names attached to thin beds, some of which 

are but local members. Prosser 648 gives the following tabulation and discusses the 

nomenclature and correlation. 

Classification of the upper Paleozoic formations of Kansas. 

Permian system (?): 

Cimarron series [red beds]: 

Kiger stage: 

Taloga formation. 

Day Creek dolomite ...................................................... . 

Red Bluff formation ................................................. . 

Salt Fork stage: 

Dog Creek formation: 

Chapman dolomite .................................................... . 

Amphitheatre dolomite ................................................ . 

Cave Creek formation: 

Shimer gypsum ....................................................... . 

Jenkins clay ......................................................... . 

Medicine Lodge gypsum ............................................... . 

Glass Mountain formation: 

Flower-pot shales ...................................................... . 

Cedar Hills sandstone .................................................. . 

Kingfisher formation: 

Salt Plain member .................................................... . 

Harper sandstone ................................................... _ . 

Big Blue series: 

Sumner stage: 

Feet.a 

1-5 

175-200 

1,000 

Wellington shales.......................................................... 200 

Marion formation........... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 

Chase stage: 

Winfield formation......................................................... 25 

Doyle shales. . . . . . . . . . . . . . . . .. . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 

Fort Riley limestone........................................................ 40 

Florence flint. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 

Matfield shales.................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 

Wreford limestone [b]....................................................... 40 

Base of the Permian. 

Adams adopts the formation names used by Prosser in the foregoing classification, from Wreford limestone to '\Vellington shale, both inclusive. 

The sequence of strata throughout the Pennsylvanian and Permian is an alternation of limestones and shales without any marked interruption of stratigraphic 

a The thicknesses given up to and including the Wellington shale are from Adams; 4 those of the higher formations from Cragin. 175•

176 

b Beede has recently traced the Wreford limestone into the McCann sandstone of Gould, yielding typical Texas 

Permian vertebrates.-Note by S. IV. 'Villiston, June, 1909. 
PERMIAN. 487 

or faunal succession. The distinction of Pennsylvanian and Permian has been 

difficult and is apparently artificial. 

Prosser 648a discusses the correlation of the \Vreford and higher formations as 

Permian-that is, the equivalent of the Russian Permian-cites the opinions of 

many geologists on both sides of the question, and considers favorably the distinction of the Permian as a system equal in rank to Carboniferous or Triassic. Beede 63 

and David \Vhite 901 regard the series as Permian. Girty 371 a accepts the Permian 

age of the Kansas and Texas beds but largely on the paleobotanic evidence adduced 

by White. 

The Cimarron "series" is not discussed by Prosser, as it is a typical red-bed 

formation and does not contain marine fossils. Cragin ma gave the following 

concise description in defining it: 

With the Wellington formation ends the Big Blue, lower, or limestone-bearing series of the 

Permian. Succeeding it without break, but possibly with a gradually introduced angular 

unconformity, are the Harper sandstones and higher prevailingly red formations that comprise 

the remainder of the Kansas Permian and constitute the Cimarron series, which, for Kansas, is 

nearly the same as the "red beds." 

So far as known, the series is destitute of any trace of organic remains. 

In Oklahoma the shale and limestone strata of the Kansas Permian give place 

to red beds, the shales becoming red and sandy and the limestones red shales or 

sandstones. The division into many small formations is lost and a different sequence 

is recognized. Gould 373 has made the following comparif'lon of the divisions of the 

Oklahoma Permian with those proposed by Cragin for Kansas: 

Relations of classijications of Permian rocks. 

Cragin's classification. Classification used in this [Gould's] report. 

Quartermaster formation. 

------

Taloga. Greer formation. 

Mangum dolomite member. 

Collingsworth gypsum member. 

Cedartop gypsum member. 

Haystack gypsum member. 

Kiser gypsum member. 

Chaney gypsum member. 

Day Creek. Day Creek dolomite member. 

Red Bluff. Woodward formation. Whitehorse sandstone member. 

Dog Creek (Stony Hills). Dog Creek shales member. 

-

Cave Creek. Blaine formation. 

Shimer gypsum member. 

Medicine Lodge gypsum member. 

Ferguson gypsum member. 

- -~-

Glass Mountain. Enid formation. Kingfisher. 

·-

The several formations are described by Gould 373a as follows: 

The Enid formation consists chiefly of brick-red clay shales with some interbedded ledges 

of red and whitish sandstone. It occurs in two general areas, which may be distinguished on 

lithological grounds as follows: An eastern area, in which there are a few inconspicuous ledges 
488 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

of sandstone, and a western area in which the sandstones are mostly wanting. In the present 

state of knowledge it is impossible to draw an accurate line of separation between these two 

areas, and for this reason the strata in them are not defined as separate members. 

The eastern area of the Enid formation is triangular and occupies several counties in the 

central part of the Territory, in which there is little hard rock of any kind. 

* * * * * * * * * 

Throughout this area the soil is red, except where later deposits cover the uplands or 

among the sand hills north of some of the streams. Red clays and occasional ledges of thin 

sandstone outcrop along the bluffs of a few streams. 

* * * * * * * * * 

The rocks of the western area of the Enid consist chiefly of red clay shale, some inconspicuous 

ledges of soft sandstone, and occasional bands of whitish or greenish shales, which vary from 1 

inch to several feet in thickness. The upper strata are in some places highly gypsiferous, and at 

some localities brine springs issue from them. 

* * * * * * * * * 

The Blaine formation consists of red shales with interbedded strata of gypsum and thin 

ledges of dolomite. It includes the portion of Prof. Cragin's Flowerpot formation above the 

base of the Ferguson gypsum and all of his Cave Creek formation. It is named from Blaine 

County, Okla., where it is typically developed. 

The characteristic which justifies its recognition as a formation is the abundance of gypsum 

contained in it, and its extent and limits are defined accordingly. The bottom of the lowest 

massive gypsum bed-the Ferguson gypsum member-is the base of the formation throughout 

its occurrence northwest from Darlington, Canadian County. VVhere it disappears the shales 

of the Enid continue up to the base of the Medicine Lodge gypsum member, which necessarily 

becomes the basal member of the formation. The top is the Shimer gypsum member. VVhere 

the gypsum members run out, as they all do north of Darlington, the Blaine can not be distinguished readily from the Enid below and the Woodward above, and this local division of the 

red beds can not well be traced. 

* * * * * * * * * 

The thickness of the Blaine formation varies considerably with the locality, but it averages 

about 75 feet. 

Above the Blaine are approximately 300 feet of rocks consisting chiefly of shales, sandstones, and dolomites and distinguished from the formations above and below by the prominence of dolomites and the absence of gypsum. The formation includes all the rocks between 

the two conspicuous gypsum horizons, the Blaine and the Greer, and in general it may be 

divided into three members-the Dog Creek, the VVhitehorse, and the Day Creek-which were 

all recognized and named by Prof. Cragin from localities in Kansas, except that his term Red 

Bluff was preoccupied, and for it the name Whitehorse has been substituted. For the formation as a whole, from the top of the Shimer gypsum to the base of the Chaney gypsum, the name 

Woodward is proposed, from the county in Oklahoma where the strata are well represented. 

* * * * * * * * * 

Above the Woodward formation are red clays, shales, and sandstones, and intercalated 

beds of gypsum and magnesium limestone or dolomite 150 to 300 feet thick. Gypsum is the 

characteristic deposit of this formation, as it is of the Blaine. The formation for which the 

name Greer is proposed, from the county in southwestern Oklahoma where it is well exhibited, 

is exposed over a very irregular area. For purposes of discussion it may be grouped according 

to two general areas, an eastern and a western. 

* * * * * * * * * 

The rocks of the eastern area of the Greer formation strike northwest and southeast just 

west of the outcrops of the Woodward formation. They are chiefly red clay shale, interstratified at several horizons with red sandstone and gypsum, which are, however, very irregularly 

bedded and can rarely be traced as continuous or definite ledges. Nevertheless, the thickest 
PERMIAN. 489 

ledges of gypsum lmown in the red beds are found in this area. Thus 5 miles northwest of 

Weatherford a ledge 60 feet thick was measured; in the vicinity of Cloud Chief, beds 50 feet 

thick are not uncommon; and in a well near Seger, Washita County, a ledge 115 feet thick is 

reported. But these beds are not constant, thickening rapidly or disappearing without apparent 

regularity. Along a single bluff one may see the beds change from gypsum to sandstone within 

a distance of a few rods, and a quarter of a mile farther the sandstone again merges into gypsum. 

So variable is the stratification of all the rocks of the Greer formation in this region that no 

attempt is made to divide it into members. A section would usually not answer for a point 

half a mile away. 

* * * * * * * * * 

Above the Greer are 300 feet or more of soft red sandstones and arenaceous clays and 

shales, to which the name Quartermaster has been applied. So far as known this is the highest 

formation of the red beds in Oklahoma. 

In the lower part of the formation the rocks are chiefly shales, typically red but sometimes containing greenish bands and layers. The shales become more arenaceous above and 

in places form a strong consolidated sandstone, which is rather thin bedded and prone to break 

into small rectangular blocks and weather queerly into long and narrow buttresses or rounded, 

conical, or nipple-shaped mounds from 10 to 50 feet or more high. These mounds may be 

solitary, but in some areas hundreds of them occur in a single quarter section. The sandstone 

is further characterized by the marked and very peculiar dip of the rocks in certain directions. 

The strata often dip at angles of from 20° to 40° to all points of the compass, even in a small 

area. These dips often produce escarpments that have the appearance of those formed by 

regularly bedded dipping strata. The most plausible explanation of this phenomenon is that 

the erratic dipping is caused by the undermining of deep-seated rocks, probably some of the 

various gypsum members of the Greer. 

Regarding the age of the red beds of Kansas and Oklahoma, Gould 373b makes 

the following statement: 

The scarcity of fossils in the Kansas-Oklahoma red beds has been a matter of comment 

ever since these rocks have been studied. In Kansas, particularly, Hay, Cragin, Prosser, 

Beede, Williston, and others have at various times searched carefully over the counties in 

which these rocks are exposed, but without avail. So far as lmown not a single fossil has ever 

been found in the Kansas red beds. 

In Oklahoma, fortunately, the results have been more satisfactory. Not that the fossils 

are abundant, for they are in fact very rare, yet enough forms have been found at various 

horizons to assist the geologist in the classification of the rocks. Four years ago the geologic 

age of the red beds was not certainly known, for at that time fossils had been found in but one 

locality, and these for the purpose of correlation were far from satisfactory. Of the five localities west of the provisional base of the Permian from which fossils have been obtained in Oklahoma, two only have yielded invertebrates, in two other localities vertebrates alone have been 

found, and from the fifth locality vertebrates, invertebrates, and plants have been secured. 

A brief description of these localities and the fossils obtained from each will be given. 

On the farm of W. T. McCann, 5 miles southeast of Nardin, Kay County, a number of 

fossils were found in a ledge of sandstone which lies just at the base of the red beds. A vertebrate, identified as Eryops megacephalus by Dr. S. W. Williston, a small crustacean, Estheria 

minuta, and some fossil leaves comprise the collection. [The McCann sandstone of Gould is 

traced stratigraphically by Beede to the Wroford limestone of Kansas. See note b, p. 486.] 

Dr. E. C. Case has identified the following forms obtained near Orlando, Logan County: a 

Pisces: 

Diacranodus (Pleuracanthus) ampressus (?) Cope. 

Sagenodus (?) sp. 

a Case, E. C., On some vertebrate fossils from the Permian of Oklahoma: Second Biennial Rept. Oklahoma Geol. 

Survey, 1902, pp. 62, 68. 
490 INDEX TO THE STRATIGRAPHY OF NORTH M1ERICA. 

Batrachia: 

Diplocaulus magnicornis (?) Cope. 

limbatus (?) Cope. 

salamandroides Cope. 

Trimerorhachis sp. Cope. 

leptorhynchus sp. nov. 

Cricotus sp. Cope. 

Cricotillus brachydens g. et sp. nov. 

Eryops megacephalus Cope. 

Crossotelos annulatus g. et sp. nov. 

Reptilia: 

Naosaurus sp. Cope. 

Embolophorus (?) sp. Cope. 

Pariotichus ordinatus Cope. 

sp. Cope. 

Pleuristion brachycoelous g. et sp. nov. 

A number of vertebrates have recently been discovered 5 miles east of Pond Creek, Grant 

County. These bones have not been identified, but from superficial examination they appear 

very similar to the specimens from Nardin or Orlando. 

In a ledge of soft, sandy dolomite which underlies the :Medicine Lodge gypsum near Ferguson, Okla., a number of invertebrates have been found, among which Dr. J. W. Beede finds 

the following forms: Pleurophorus subcuneatus Meek, Schizodus (?) likeS. wheeleri. 

Near Whitehorse Spring, 16 miles west of Alva, a considerable number of invertebrates 

were obtained. Dr. Beede identified the following genera: a N aticopsis, Pleurotomaria, Pleurophorus, Lima, Sedgwickia, Aviculopecten, Bakewellia, Conocardium, and Dielasma. The last 

four genera arc represented by new species. 

Regarding the age of the red beds, Dr. ·williston identifies Eryops megacephalus, from 

Nardin, as a Permian amphibian, described by Cope, from Texas. Of the Orlando fossils, he 

says: "Altogether these fossils unmistakably point to the Permian." Dr. Case points out the 

close resemblance of these fossils to similar forms from the Permian of northern Texas, Ireland, 

and Bohemia. b 

Dr. Beede, in the paper referred to, in speaking of the Whitehorse invertebrates, says: c 

"On the whole, these fossils show an advance over the fossils of the Permian below. Some 

of the species still persist, as we should expect from the fact that there is no unconformity 

between these various formations. On the other hand, there is a new species of Dielasma 

belonging to a group new to the American Permian. * * * Taking all this into consideration, there can be little doubt that the age of these beds is Permian." 

Of these localities, Orlando, Nardin, and Pond Creek are in the Enid formation, Gypsum 

Hills locality in the Blaine, and the Whitehorse locality in the Whitehorse sandstone, the 

middle member of the Woodward formation. So fas as known no fossils have been found in 

the Greer and Quartermaster formations of Oklahoma, but there is no reason for supposing 

that these beds differ greatly in age from those immediately subjacent. d 

J-K 13. SOUTHERN WYOMING AND NORTHERN COLORADO. 

The so-called "Red Beds" of this region, long supposed to be chiefly or wholly 

Triassic, are now known to be in part at least Permian. The Triassic age of the 

remaining upper portion has been questioned but is established by Williston. 

Prior to Williston's publication, Cross 193m reviewed the evidenqe as follows in part: I 

The Red Bed section of the mountainous portion of Colorado and Wyoming is clearly not 

divisible into the units traceable throughout the plateau province. * * * The changes in 

a Beede, J. W., Advance Bull. Second Ann. Rept. Oklahoma Geol. Survey, April, 1902. 

b Letter of November 24, 1900. 

cOp. cit., p. 62. 

d Since the above was written fossils found in the Quartermaster sandstone in Collingworth County, Tex., have 

been identified by Dr. Beede, who finds that they are very similar to those from Whitehorse and of Permian age. 
PERMIAN. 491 

lithologic character in the mountain province are much more notable and render correlations 

less certain. * * * Until many districts have_been reexamined with care, it will be premature to attempt direct correlation of the Dolores and Cutler formations as such with the 

elements of sections in central and northern Colorado; but there are various facts bearing on 

the distribution of Triassic and Carboniferous Red Beds which may be briefly presented: 

* * * * * * * * * Turning to the lower part of the Red Beds, evidence has recently been presented by the 

late W. C. Knight showing that in tho Laramie Basin of southern Wyoming the Triassic strata 

of Hayden and King should be referred in part at least to the Carboniferous system and probably 

to the Permian series. Knight gives a section of 1,578 feet of Red Beds which rest on granite. 

A little below tho middle of this section a fossiliferous sandstone was found, the fauna resembling 

"to a marked degree tho fossils of the Kansas and Nebraska Permian." Only one thin limestone was noted in the section, but Knight made tho significant observation "that the strata 

of the lower portion of the Red Beds are identical with the strata of limestones to the northward, 

tho difference in the lithological characteristics being duo to tho varied physical conditions 

during sedimentation." 

Those limestones also contain in their upper portion a fauna resembling that of the Kansas 

"Permian," but Knight remarks that Coal Measure fossils have not as yet been collected from 

tho lower beds. 

Since Knight could find no stratigraphic or fossil evidence for subdividing the Red Bed 

section of the Laramie Plains, he refers it as a whole to the Permian and compares it particularly 

with the Permian of Kansas and Oklahoma. * * * 

Accepting the views expressed by Knight concerning the fauna of Red Beds of the Laramie 

Plains, it is clear that tho section above his lowest fossil-bearing horizon is younger than tho 

Rico formation [Pennsylvanian] but may correspond as a whole or in part to tho Cutler formation. * * * The unfossiliferoc1s portion whose reference to the Permian is still open to 

possible doubt is 850 feet in thickness, and it does not appear that the section was complete, 

up to the Jurassic beds. There is, therefore, ample room for a Triassic formation in the Red 

Beds of the Laramie Plains.a * * * 

In the vicinity of the Triassic horizon observed by Hills [on Grand and Eagle Rivers, Colorado] the upper Paleozoic section is of very different character from that near Laramie, but its 

upper portion was assigned to tho Permian by Peale on the basis of a few plants considered by 

Lesquereux as of that age. The strata so referred are gypsiferous shales of various colors, 

yellow, pink, and creamy, with some limestone, and are not to be correlated either with the 

Laramie Permian or the Cutler beds on present evidence. These gypsifcrous beds are overlain 

by the Red Beds of Peale, assigned to the Triassic, and seemingly this division must include the 

bone beds of Hills, since the succeeding formation is apparently the normal fresh water Jura. 

* * * The well-known Red Bed section of the Front Range foothills in Colorado was 

assigned to the Trias upon no definite evidence, by geologists of the Hayden Survey. * * * 

In the Denver monograph Emmons and Eldridge named the entire Red Bed section of 

that district the Wyoming formation, distinguishing within it the lower and upper divisions, 

on purely lithologic grounds. The Lower Wyoming embraces beds like the Fountain in lithologic character and, in addition, the quartzose Creamy sandstone. Both Emmons and Darton 

have recognized tho resemblance of the red arkose strata of the Lower Wyoming to the Fountain beds; but the suggestion of the latter that the Fountain and Lower Wyoming are quite 

€quivalent is to my mind less natural than to consider the Lower Wyoming a group embracing 

the Fountain beds and the lithologically distinct "Creamy sandstone," which Darton thinks 

is equivalent with the Tensleep sandstone of the Bighorn Mountains, Wyoming, and which in 

any case deserves a special name. 

The Upper Wyoming of the Denver region embraces the remainder of the Red Bed section, and it is referred to the Trias by Emmons and Eldridge. Darton, however, in his valua At Red Mountain, south of Laramie City, characteristic Upper Triassic vertebrates occur in the uppermost 

"Red Beds." See Williston, S. W., Jour. Geology, vol. 13, 1905, p. 3:-l9.-B. W. 
492 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

able discussion as to the correlation of formations of the Black Hills, Bighorn Mountains, 

and the Front Range presents reasons for supposing that the Upper Wyoming, as developed 

near Denver, may be wholly referable to the Permian series. This is based on stratigraphic 

relations and the belief that a limestone occurring shortly above the "Creamy sandstone" is 

the equivalent of the Minnekahta limestone of the Black Hills, where it contains Bakewellia 

and Edmundia, forms apparently identical with those characteristic of the so-called Permian 

of the Mississippi Valley. 

Poorly preserved shells of similar appearance were found in the limestone at Morrison. 

Darton believes that the Opeche and Minnekahta (Permian) and the Spearfish (Triassic?) 

formations, distinguished by him in the Black Hills, extend southward through Wyoming 

into northern Colorado, but as their exposures are not continuous, and as lithologic details 

vary in the different areas of outcrop, he proposed Chugwater as a group term, which is thus 

practically equivalent to Upper Wyoming. Darton states that the upper or Triassic ( ?) portion of the Chugwater group thins out and disappears before the Denver area of Red Beds is 

reached, leaving only the supposed Permian as present in the Morrison and Golden sections 

especially described by Eldridge. 

From the brief review ]ust given it appears that the Red Bed section of the Front Range 

foothills contains no member to be correlated with the fossiliferous Triassic (Dolores) of the 

western portion of Colorado. The views of Darton and the writer harmonize in referring the 

entire Red Bed section of the Denver region and southward, at least to the Canyon City embayment, to the Paleozoic. The Fountain beds seem to me to be synchronous in origin with the 

Pennsylvanian formations of the San Juan region. An unconformity separates each from the 

Mississippian Carboniferous (Millsap or Ouray) and above each in apparent conformable relation is a nonfossiliferous complex of Red Beds. On the west slope these are embraced in the 

Cutler formation, while at the base of the Front Range is the more variable section of the 

Wyoming group, succeeding the Fountain. That the beds of the Wyoming group (excluding a. 

possible Triassic portion) are coextensive with the group consisting of the Molas, Hermosa, 

Rico, and Cutler formations of the San Juan is of course not to be assumed. 

J-K 17. PENNSYLVANIA, WEST VIRGINIA, AND OHIO. 

The Dunkard group is the highest Carboniferous of the 

and is classed as Permian on the evidence of fossil plants. 

states its occurrence and character: 

Appalachian basin 

Stevenson 797b thus 

The Dunkard area is much smaller than that of the Monongahela, embracing little more 

than 7,000 square miles. It is confined to Washington and Greene counties of Pennsylvania, 

the western-central counties of West Virginia, and Belmont, Noble, Monroe, Washington, and 

Meigs of Ohio. Small outlying areas occur in other counties, but they are insignificant. At 

one time the beds of this formation were continuous eastward to beyond the Alleghenies, as 

fragments remain in Maryland and west-central Pennsylvania. The extreme thickness, as 

found in the southwest corner of Pennsylvania at the West Virginia line and determined by 

oil-well records, is a little less than 1,200 feet. The thickness decreases greatly toward the 

north, the bottom 475 feet becoming about 165 feet at the most northerly exposure and the 

succeeding 240 feet is reduced to 150 feet at its northernmost exposure, nearly 30 miles south 

from that of the lower interval. There is a similar decrease in a northwestward direction, and 

toward the southwest one finds the bottom 700 feet of the thickest area reduced to barely 500 

feet in Tyler of West Virginia, 35 miles away. Nothing can be determined respecting conditions 

toward the east, as erosion due to great anticlines prevents comparison with the fragments 

east from the Alleghenies in the deep basins of Broad Top and Maryland. 

In the original description of this formation as it is in Pennsylvania, Stevenson divided 

it into the Washington County and the Greene County group, placing the plane on top of the 

Upper Washington limestone. Aside from the convenience of a division in a column of such 

length and complexity, one must recognize in the physical conditions good reasons for this. 
PERMIAN. 493 

separation. These, as will be seen, appear only in part along Dunkard Creek, where Dr. White's 

studies led him afterward to group the whole succession into one formation, the Dunkard. 

They are best shown farther north, in central Greene County, where they justify a return to 

the original grouping and to the recognition of the Washington and Greene formations as of 

equal rank with the Monongahela and others below. 

In the Washington and Greene formations, which compose the Dunkard 

group, Stevenson distinguishes sixteen and eighteen members respectively, alternations of coal, limestone, and sandstone. 

The comprehensive study of the Dunkard flora by Fontaine and I. C. White 344 

was revised by David \Vhite. 897 Stevenson 797 reviews the evidence as follows: 

The results of this revision were published in 1903. The collections, made at the typical 

as well as at other localities and horizons, led Mr. [David] White to place the forms in five categorics-(a) those characteristic of the Rothliegende or higher formations of the Old World; 

(b) those closely allied to Permian types; (c) those whose habit and facies suggest a late date; 

(d) those of Mesozoic aspect; (e) Coal Measures type. 

In the first category Mr. White places three species of Callipteris, one each of Goniopteris, 

Pecopteris, Alethopteris, Odontopteris, Caulopteris, Equisetites, and Sigillaria, with two species 

of Sphenophyllum; in all, 12 species. In the second are also 12, but the author states that the 

number might be extended according to the personal equation of the observer or to the amount 

of material available for comparison, while, at best, evidence of this class is of subordinate 

value, some of the forms placed here belonging with equal propriety also .in succeeding categories. He places in the third category 14 forms, all of them new and unknown elsewhere; 

these in their general facies suggest a later date than Coal :Measures. He places 9 forms in 

the fourth category and regards their presence as an interesting and important argument for 

Permian age, for they are types whose nearest relatives are Mesozoic or whose facies strongly 

suggest types characteristic of 1Iesozoic. Here are species of Equisetites, Saportrea, Jeanpaulia, and Treniopteris, as well as other genera. On the other hand arc forms belonging to 

the fifth category, a considerable element of Coal Measure species, whose presence is invincibly 

against reference of the beds to a level above the basal Permian. The number of species common to the Dunkard and lower formations, only 22 at the time when Profs. Fontaine and I. C. 

White published their work, is now known to be much greater, as the Monongahela flora has 

been studied in part. Mr. White enumerates 29 common forms which are of ordinary occurrence in the Coal Measures, these being only the more widespread forms, more than one-half 

of them appearing frequently in the Allegheny or Conemaugh. 

Mr. White finds in the Dunkard plants a transitional flora, such as would be expected in a 

region where conditions remained practically the same. The boundary between Coal Measures 

anJ Dyas is to be determined by the appearance of characteristic Rothliegende species rather 

than by the presence of persistent Coal Measure types. In western Europe the presence of 

Callipteris, simple fronded Treniopteris, Callipteridium of the gigas or regina type, and the genus 

W alchia in a flora consisting largely of forms common to the Coal Measures is regarded as sufficient evidence of Rothliegende age, though Callipteris conferta and even W alchia may appear 

lower down. In the Appalachian region a small form of Callipteris conferta appears at the 

horizon of the Lower Washington limestone, while the typical larger form, with Callipteridium 

gigas and others, is unknown below·the Dunkard eoal bed. The evidence of Rothliegende age 

for beds below the Lower Washington limestone consists in the presence of Eguisetites rugosus 

and several less important forms and of some others which have Mesozoic or Permian aspect; 

but these latter are extremely rare, having been found only in a single coal drift, though careful 

search has been made for them elsewhere. 

Mr. White regards the beds below the Lower Washington limestone as containing a transitional flora and not distinctly Rothliegende, but above that limestone the flora becomes increasingly characteristic. As in that limestone is the first appearance of Callipteris conferta, he 

thinks the lower limit may be drawn safely at that horizon. The flora of the upper Dunkard 
494 INDEX TO THE STRATIGRAPHY OF NORTH M£ERICA. 

is to be compared with the Stockheim and Cusel beds in Germany and the series in the basin of 

Brives, in France. None of the characteristic coniferous genera Ullmannia, Tylodendron, 

W alchia occurs in Dunkard beds, though all are in Prince Edward Island and Walchia is reported 

from Texas; and similarly many genera of ferns characterizing the Rothliegende of Europe 

seem to be wholly unrepresented. 

In connection with Mr. White's conclusions, it is well to recall some relations noted in 

preceding pages. The general physical conditions during Allegheny and Conemaugh were 

practically the same, for while the basin was contracting there was no material variation in 

character of tho movements, but with th& beginning of the Monongahela the area of greatest 

subsidence was shifted a hundred miles and a new condition remained unaltered throughout 

the Monongahela and Washington, which in this respect are one as the Allegheny and Conemaugh are one. A notable change occurred at the vV ashington, and Mr. White has shown that 

the strongly marked lower Rothliegende flora makes its appearance near the bottom of the 

Greeno formation. 

K 10. KLAMATH MOUNTAINS, CALIFORNIA. 

Certain limestones of the Klamath Mountain region are faunally more closely 

related to the Guadalupe group of the Permian of trans-Pecos Texas than to any 

other terrane in the United States.a (See pp. 359-360, Chapter VIII.) 

K 12-13. WYOMING, NORTHERN COLORADO, AND UTAH. 

In the Park City mining district, northeastern Utah, Boutwell distinguished 

the Woodside shale, Thaynes formation, and Ankareh shale. (See section given on 

p. 380, Chapter VIII.) The Woodside is a fine-grained unfossiliferous red shale 700 

to 1,180 feet thick, which conformably overlies the Park City formation (Pennsylvanian). The Thaynes is characteristically calcareous and rich in fossils. It is 

1,190 feet thick. In 1907 Girty reported that "the fauna and horizon are those 

which in the Fortieth Parallel Survey reports are called Permo-Carboniferous" and 

said: "It seems probable that the fauna will be correlated with the Permian of the 

Grand Canyon section." Revising this statement in 1910, he states: "Latest information makes it doubtful whether these are not Triassic, in part almost certainly 

equivalent to the Triassic of Idaho." 

The Ankareh shale is a siliceous red shale and sandstone, 1,300 feet thick, which 

on rather meager paleontologic evidence is classed as Permian.933 

The Woodside and Thaynes formations of northeastern Utah were recognized 

by Veatch839 in southwestern ·wyoming, where they have a development similar 

to that at Park City. Above the Thaynes limestone and below the fossiliferous 

marine Jurassic, Veatch distinguished the Nugget formation, which he chssed as 

Triassic(?). His Nugget comprised two members, a bright-red sandy shale, reaching 

a maximum thickness of 600 feet (now correlated by Gale with the Ankareh shale), 

and an upper sequence of .light-colored sandstones (to which the name Nugget is 

now restricted). 

The divisions of the red beds recognized by Veatch were in 1906 traced northward by Schultzb into central Uinta County, Wyo. 

The region examined by Boutwell, Veatch, and Schultz is the western part of 

the province in which the red beds of Permian and Triassic age are developed. 

aGirty, G. H., personal communication. b Schultz, A. R., personal communication. 
PERMIAN. 495 

Formations similar to those described occur about the Bighorn Basin and Mountains, but the divisions have been called by local names, as equivalent formations 

in the two areas are not identified. 

In the Bighorn Mountains Darton237•

239t distinguished the Amsden formation, the 

upper part of which contains a distinct Pennsylvanian fauna and the lower part of 

which in some areas is of Mississippian age. Succeeding the Amsden, he recognized 

the Tensleep sandstone (Pennsylvanian), the Embar formation (Pennsylvanian and 

Permian~), and the Chugwater formation (Triassic or Permian). The Tensleep is 

a massive white sandstone, in part calcareous, and the Embar consists of limestones 

with associated shaly and cherty beds. The characteristic fossil of the Embar is 

Spiriferina pulchra, which occurs just below the "Permo-Carboniferous" of the 

Wasatch Mountains and the Permian of the Grand Canyon. The Embar thins out 

northward and in the northern part of the Bighorn Range the Chugwater formation 

rests on the Tensleep sandstone. 

The Chugwater formation thus occupies part or all of the stratigraphic interval 

between the Pennsylvanian and the marine Jurassic (Sundance formation), in 

northern Wyoming. It is a typical red-bed formation from 600 to 1,200 feet thick. 

Darton 239 d describes it as follows, in part: 

The rocks are mainly soft, massive, red, fine grained sandstones, merging into red shale, 

but extensive gypsum deposits and a few thin limestone beds are also included. * * * 

The general character of the Chugwater deposits does not vary greatly in different portions 

of the region. Toward the top and bottom red shales predominate, while in the middle soft 

sandstones and alternations of sandstones and shales are the principal features. Near the 

base there is invariably a thin bed of purplish-gray limestone, generally varying in thickness 

from 5 to 15 feet. Fifty feet or more higher there is another bed of limestone, mostly massive, 

of dirty-gray or buff color, in which weathering develops a characteristic porous structure. 

This bed has a thickness of 10 to 15 feet along the east side of the uplift and to the south, but 

along the west-central and northwestern slopes of the mountain its thickness increases considerably and it forms a conspicuous ledge. Toward the top of the formation there is always 

a succession of thin-bedded, light-colored limestones separated by red shales. These limestone bodies vary from two to four in number, and they are usually separated by from 10 to 

50 feet of shales. Gypsum deposits occur in the Chugwater formation in irregular bodies in 

the lower and upper portions, the most persistent bed or series of beds being not far from the 

base. The formation attains its greatest thickness in the region northwest and southwest of 

Buffalo, where it measures 1,230 feet. In the region west of Sheridan the amount is 1,100 feet 

but it gradually diminishes to the north, being only about 600 feet at Bighorn River. On the 

west side and southern portion of the range the average is about 800 feet, but it diminishes 

somewhat to the north, the amount being not over 700 feet near Horse Creek. 

Darton cites occurrences of fossils from the lower part of the Chugwater formation which are, however, poorly preserved or for other reasons indeterminate as to 

age. In the opinion of Girty and Schuchert they are probably Permian. The 

upper part at least of the Chugwater is regarded as probably of Triassic age, and 

both Darton 239e and Fisher 331a doubtfully assign the whole formation to the Triassic. 

K 13. BLACK HILLS, SOUTH DAKOTA. 

The Permian of the Black Hills comprises some indeterminate part of the red 

beds, which Darton has separated into the Opeche, Minnekahta, and Spearfish for-
496 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

mations. The Opeche and Minnekahta are now regarded as Permian, but the Spearfish is believed to be probably of Triassic age. Below the red sandstones of the 

Opec he occur other sandstones which have yielded "indistinct casts of Productus 

semireticulatus and Seminula dawsonii (Athyris subtilita)" and which are provisionally assigned to the Pennsylvanian. Concerning the formations Darton 2370 says: 

Opeche formation.-In this formation the first of the red beds makes its appearance in the 

Black Hills region. The materials are soft red sandstones, mainly thin bedded and containing 

variable amounts of clay admixture, having a thickness varying from 120 feet in the southeastern part of the hills to about half that amount to the northwestward. The basal beds of 

the formation are usually red sandstones, the beds varying in thickness from 4 to 13 inches. 

Gypsum occurs at a few points in beds which are neither thick nor extensive. 

The age of the formation has not been definitely determined, for so far it has yielded no 

fossils. From the fact that the overlying Minnekahta limestone is of Permian age, and the 

deposition of gypsiferous red beds in other regions began in Per.mian time, the formation is 

provisionally assigned to that division. 

Minnekahta limestone.-Overlying the Opeche red beds there is a limestone persistent over 

a wide area in the Northwest, which I have designated the Minnekahta limestone. Though 

thin, averaging less than 50 feet in thickness, it is hard, flexible, and, by the easy erosion of 

the red beds in which it is inclosed, outcrops in long slopes and prominent ridges. 

The rock is uniform in character throughout, being a thin-bedded light-colored limestone, 

containing magnesia and more or less clay. Its thin bedding is a characteristic feature, 

although the thin layers are so cemented together that the outcropping ledges present a massive appearance. * * * On weathering, it breaks into slabs usually 2 to 3 inches in thickness. On the western side of the hills its coloring is slightly darker, varying from a dove color 

to lead-gray, and some of the beds present a seminodular structure. An increased admixture 

of clay is also observed in some layers. The general appearance of the formation is always 

slightly pinkish, with a tinge of purple, from which fact the old term "purple limestone" 

originated. 

The limestone contains fossils at a number of localities, but the forms are not well preserved and not altogether decisive as to the age of the deposits. At a locality 15 miles westnorthwest of Hot Springs there were observed Bakewellia and Edmundia similar to those 

observed in the Kansas Permian, and from this evidence the limestone is assigned to the Permian. 

Near Sturgis similar fossils occur. 

Spearfish formation.-The designation Spearfish formation has been applied to the main 

body of gypsiferous red beds which outcrop in a broad zone encircling the Black Hills uplift. 

This formation consists of from 350 to 700 feet of red sandy clays, with intercalated beds of gypsum which sometimes are 30 feet thick. The bright-red color of the shales and the snowy white 

of the gypsum are striking features of the formation. Were it not for the gypsum the formation 

would present no noticeable features of stratigraphy, as the sedimentary material is almost 

entirely a red shale containing varying amounts of fine sand admixture. It is generally thin 

bedded. The gypsum occurs in beds at various horizons, some of the larger beds extending continuously over wide areas. There is also throughout the formation more or less secondary 

deposition of gypsum in small veins. 

The thickness of the Spearfish formation can seldom be determined with accuracy, owing 

to the softness of the material and the predominance of low, variable dips which are difficult to 

measure. Along the east side of the Black Hills the formation appears to have a thickness of 

from 350 to 400 feet, but the amount increases to the northward to 492 feet in the well at Cambria, 695 feet in a well at Sturgis, and at least 650 feet in a deep boring at Aladdin. To the southeastward the principal bed of gypsum generally varies from 5 to 15 feet, increasing southward 

in the vicinity of Hot Springs to the maximum development, in which the principal beds have 

a thickness of 33~ feet, with a 10-foot parting of red shale between. * * * Along the west 
PERMIAN. 497 

side of the uplift there is usually a bed of gypsum at a horizon about 150 feet above the base 

of the formation, and east of Newcastle for some distance there is a 25-foot bed of gypsum at 

the top of the formation, * * * several thin beds in its center, and at its base a local thin 

bed of gypsum lying directly on the Minnekahta limestone. Throughout the Black Hills the 

formation is distinctly separated from the underlying Minnekahta limestone by a very abrupt 

change of material, and from the overlying marine Jurassic deposits by a well-marked erosional 

unconformity. 

K 15. IOWA. 

Deposits of gypsum associated with red shale and sandstone which occur in 

isolated areas in the vicinity of Fort Dodge, Iowa, have been assigned to the Permian on the ground of lithologic relations, no fossils having been found. The 

occurrences are described in detail by Wilder, 929 who consider.s also the alternative 

possibilities of Triassic or Cretaceous age. 

L 20. NEW BRUNSWICK, NOVA SCOTIA, AND PRINCE EDWARD ISLAND. 

The Permian (in some of the reports called " Upper Carboniferous") of Nova 

Scotia and New Brunswick was described by Dawson, 263e Logan/45 and later by 

Fletcher 334c• 335e and Bailey.45c In Fletcher's later report 335e he subdivides the 

Permian as follows: 

l. New Glasgow conglomerate. 

2. Middle gray sandstone and shale group, with small coal seams. 

3. Upper red sandstone and shale group, with thin bands of limestone. 

These groups lie in parallel belts along the shore of Northumberland Strait between Merigomish and Wallace, dipping seaward, generally at a low angle, but broken by faults sometimes 

of considerable magnitude. Between the second and third groups there is no distinct line of 

demarcation and the subdivision is only one of convenience. 

The position of the New Glasgow conglomerate in relation to the productive 

coal measures (Pennsylvanian) has been a matter of doubt, as it resembles the 

"Millstone grit" at their base. Fletcher concludes that the "New Glasgow conglomerate is newer than the coal measures." He describes an unconformity 

between the New Glasgow and the "Millstone grit." The dip of the former is not 

so ste2p as that of the latter and "gray sandstone with greenish and reddi3h tints, 

dipping 42° to 51°, is overlain by thick beds of very coarse conglomerate which 

fills depressions in the lower beds." Again the conglomerate, though mostly composed of material from the Devonian, contains large pebbles1 some of which "are 

certainly derived from the Millstone grit or coal measures." This basal conglomerate of the Permian overla,pd upon Devonian and Silurian rocks and varies 

greatly in thicknesf', being in places perhaps entirely lacking or overhpped, yet 

elsewhere apparently 1,300 feet or more thick. 

Sections of the higher Permian rocks, with a maximum total thickness of 8,000 

feet, are given in much detail by Fletcher. 

Dawson/630 who called these strata "Upper Carboniferous," did not recognize 

the Permian in Acadia and devotes a brief chapter to the "Permian blank." His 

description -of the "Upper Carboniferous" is included in that of the Joggins 

section 263d and of other coal fields of the region. 

48011°--12----32 
498 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Bailey 45c has the following to say in regard to the "Upper Carboniferous" of 

New Brunswick: 

Upper Carboniferous (Permo-Carboniferous ?).-In the Geological Survey maps of southeastern New Brunswick, a considerable area bordering Baie Verte and portions of Northumberland Strait, and extending thence across the Chicgnecto Peninsula to Cumberland Basin and 

Shepody Bay, is referred to under the above designations, while in the accompanying report 

(1884) its author, Dr. R. W. Ells, describes the group as consisting generally of soft reddish or 

purple-brown sandstone, grits, and shales, resting unconformably upon either the Millstone 

grit or the Lower Carboniferous. Upon the western side of the Merangouin Peninsula, where 

one of the unconformable contacts is well exposed, they are estimated, by the author named, 

to have a thickness of 1,250 feet. As seen in the vicinity of Sackville, they are said to resemble 

very nearly the sandstones and associated beds of Capes Bald and Tormentine and of Prince 

Edward Island. 

Discussion of this area by Ells and Bailey will be found in Chapter VIII (p. 384). 

The rocks of Prince Edward Island are discussed by Dawson and Ells. The 

bulk of the island has been determined by Ells to be of "Permo-Carboniferous" 

age, though held by Dawson to be Triassic, except for portions along the southern 

and western coasts. Dawson 266a says: 

The principal addition to our knowledge of this formation is that contained in the report 

by. Dr. Harrington and myself published in 1871.a In this we separated as Upper Carboniferous, or "Permo-Carboniferous," an underlying series of red and gray sandstones and shales, 

holding Carboniferous plants, extending from near Cape Wolfe toward the north point, and a 

similar series found at Governor's Island and Gallas Point in Hillsborough Bay. These are 

undoubtedly extensions of the Carboniferous of Nova Scotia. All the rest of the island is 

occupied with Triassic rocks, in one place (Hog Island, in Richmond Bay) associated with trap. 

The general relations of these rocks are seen in the sections. 

The beds of the Triassic series, as seen in Prince Edward Island, consist chiefly of soft 

red sandstone, with some buff-colored beds and red and mottled clays. Associated with them 

are conglomerates and hard calcareous and concretionary sandstones, passing into bands of 

arenaceous limestone, which is in some places a dolomite. * * * [Section in Orwell Bay 

and vicinity given.] 

The whole thickness of these beds can not much exceed 500 feet. Of this the lowest 270 

feet * * * may be referred to the lower division, or "Bunter," and the remainder to the 

upper division of the formation, or "Keuper." The dips are so low and the beds so much 

affected by oblique stratification that those of the Trias can not be said to be unconformable 

to the underlying Carboniferous rocks, and for this reason, as well as on account of the similarity 

in mineral character between the two groups, some uncertainty may rest on the position of the 

line of separation. That above stated depends on fossils, or a somewhat abrupt chango of 

mineral character, and on a slight change in the direction of the dip. These beds spread over 

the greater part of the island, presenting a nearly horizontal attitude or lying in very flat synclinals and anticlinals. They are well seen in the coast cliffs in many places, and several of 

these coast sections are given in the report above referred to. 

Ells 308 in his report on explorations in the Gaspe Peninsula discusses the age 

of the strata of Prince Edward Island and their resemblance to the rocks of New 

Brunswick and concludes: 

It will be seen by reference to the report on this province by Drs. Dawson and Harrington 

(1871) that though the larger part of the island was at that time considered by the authors 

as of Triassic age, certain portions, among which are the coast from West Cape to Nail Pond 

a Report on the geological structure and mineral resources of Prince Edward Island. 
PERMIAN. 499 

and the Yicinity of Gallas Point, were considered as pertaining to the upper Carboniferous. It 

is, however, manifest, from a close study of the various strata from Cape North to Point Prim, 

that both from their lithological character and the stratigraphical evidence no such separation 

can be carried out. The great similarity also of all the plant remains from so many points tends 

to confirm the impression that the whole of the strata exposed along the south and west coast 

must be assigned to the same horizon. The occurrence also of similar bods in the province of 

New Brunswick, about whose age but little doubt can exist, as well as on the coast of Pictou and 

Colchester, which have already been assigned to the upper portion of the Carboniferous, strengthens this view. We have therefore from the careful consideration of all these facts been led to 

remov<j the great bulk of the island rocks, from the position which they have so long held as 

Trias and to classify them under the head of Permo-Carboniferous. 
Color, dark green (horizontal ruling). 

Symbol, 10. 

CHAPTER XII. 

TRIASSIC. 

Distribution: Central America, Mexico, New Mexico, and Texas; Nevada and California; 

British Columbia and Alaska; Atlantic slope from North Carolina to Nova Scotia. 

Content : Marine Triassic of western Nevada and California; marine Triassic of Zacatecas and 

red beds in Mexico; red beds of Texas and New Mexico; Newark group, North Carolina 

to Nova Scotia; marine Triassic of the Arctic. In the Canadian Rockies the marine 

Triassic is mapped with the "Paleozoic undivided" (19, 20). In Oregon, Idaho, middle 

western United States, and part of Alaska it is combined on the map with Jurassic (9). 

Triassic areas. 

Page. 

D 16 ...•..•........ ___________ .Honduras and Nicaragua._. ___ ..... ___________________ .. __ . ______ .. _._____ 501 

D-E 15 ........ __ . _ .. _. ________ Chiapas and Guatemala ...... _ ..... _ ...... ______ ... _________ . ________ ..... _ 503 

E-F 14 ...... ___________ . __ . ___ Central and northern Mexico (Triassic mapped with Jurassic in part). __ . __ ... _ 504 

I 11. ..... ___ ...... ___ . ________ Southern California. ___ ..... _ ......... __ . ______ ... _____ .. __________ ._..... 505 

113-14 ....... ____________ . ___ .Eastern New Mexico and western Texas .... ___ ._ .. ___________ . _____ ._._____ 506 

I-J 17 ...... ___ . ______ . _______ .North Carolina. ____ ._. __ ........ _. __ ...... ______ .. _______ . ____ ._ ... __ ._.__ 508 

I-K 12-13 ..... ____ . ___________ Utah, Colorado, New Mexico, and Arizona (mapped as Triassic and Jurassic)._ 510 

J 17-18 ...... _______________ ._.Richmond Basin, Virginia. ___ ....... _____ . _________ . ____ . _______ . _______ .. 518 

J-K 10 .... _____ ... _____ . _____ .Northern California. ______ . ______ - __ .... ____________________ ..... _____ .... 519 

J-K lO-lL ______ .. _. ______ . __ .Nevada and eastern California. ______ ..... ____ ..... _________ . ____ . __ . ___ ._. 521 

J-K 18 ...•........ _. _________ .New Jersey, Pennsylvania, and Maryland .. -...... __ .. __ .... ____ .. - ____ ..... 522 

J-L 10--12 ...•.•...• ___ . ________ Western United States (mapped as Triassic and Jurassic) .. ______ . _ .... _____ . 527 

K 12 .•.... ___ .. _ .... _. _______ .Southeastern Idaho (mapped as Triassic and Jurassic) ... _ .............. _____ . 528 

K 12-13 ••.•... _. ________ . _____ Wyoming and adjacent areas (mapped as Triassic and Jurassic) .......... _ ... _ 530 

K 18 ...•........ _. ________ . ___ Connecticut and Massachusetts __ .............. -........................... 532 

K-L 13 ...•.......•. __________ .Black Hills, South Dakota (mapped as Triassic and Jurassic) .•...•.... ______ . 533 

L ll .•..•......• ___ . _. _______ .Northeastern Oregon and western Idaho (mapped as Triassic and Jurassic) .. _ _ 533 

L 12 .....•..••...•..•.•.. ______ Yellowstone National Park (mapped as Triassic and Jurassic) ..... _. _____ . _. _ 534 

L 20 ......•.••.•..•••.•.•.. ____ Nova Scotia ... __ . _ -... ___ .... __ . _ . ___ ............ · ......•.. ___ ...... ___ . . . . 535 

M 9-10 .........•.•...... _. ____ Vancouver Island (mapped with metamorphic Paleozoic undivided). ___ ._.___ 536 

M 10 .. _. ____ .. _ ....... ________ Kamloops district, southern British Columbia ..•...•.......••.... __ ..... _ _ _ _ 538 

N 8-9 .•...•...••... ________ ._._Queen Charlotte Islands (mapped with metamorphic Paleozoic undivided) ... _ 539 

N-0 ll ••.•.•.. _______ . ________ Peace River Pass, British Columbia (mapped with Paleozoic undivided)_._ .. _ 541 

0 5 .•........... _ . ___ .... _____ Cook Inlet, Alaska_ ....... ___ . _ ..... _ ......... _ ..........•.......... _ _ _ _ _ _ 541 

0 7-8 .•..... _ ..... _________ ._.Southeastern Alaska (mapped as Triassic and Jurassic) .......... __ .__________ 542 

0 9 ... ___ .. ______ . __________ ._Dease and Liard rivers, British Columbia (mapped with Paleozoic undivided). 542 

P 7 _. _ ..... _ ... _ ... ____________ Wrangell Mountains, Alaska (in part mapped as Triassic and Jurassic) . . . . . . . . 543 

P 8 .... _. _ ... __________ . _ . _____ Stewart River section, Yukon Province (mapped with metamorphic Paleozoic 

undivided) ...... _______ ._. ______ ....... _. ____ . _____ .. _._ .. ___ . ____ ..... 544 

R 3 .... _. _. _. _____ . __________ ._Cape Thompson, northwestern Alaska ...... _. __ ...... ____ ... _ ...... _ ...... _ 545 

R 27 _. __ .. __ ...... ____ . __ . _____ Northeast coast of Greenland_ ...... ___ ... _ . _ .... _ . _ ....... ____ ..... _ . . . . . . . 546 

T ll, 13-16 .. _. _______ . _ . ______ Arctic Archipelago. _________________ . _ .... _ ...... _ .. _ . _. _ . . . . . . . . . . . . . . . . . 54 7 

U 18-21 .• _ ..• _. _ ... _ . ____ . _ .. __ Grinnell Land and northern Greenland.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • . 54 7 

D 16. HONDURAS AND NICARAGUA. 

Sapper,~ 95 a in his account of the geology of southern Central America, states: 

In the department of Tegucigalpa there occurs a series of marine clays, slates, sandstones, conglomerates, and interbedded limestones which have been determined as upper 

500 
FIGURE 14.-Sketch map showing the distribution of Triassic rocks and of undivided Triassic and Jurassic rocks that 

are so represented on the geologic map of North America and the key to references in the text. 

501 
502 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Triassic on the basis of the discovcryof cycads near San Juancito. It remains, however, a mooted 

question whether these fossils are sufficiently characteristic to establish the age with certainty. 

[See below.] The thickness is considerable (more than 800 feet) and the petrographic character 

is very variable. Red colors predominate. According to Leggett the formation occurs not only 

in the vicinity of Tegucigalpa and San Juancito but also near Sabana, and Dr. Fritzgartner states 

that it has a wide occurrence in the neighborhood of Danli, where the limestones attain a 

notable development. 

The petrographic resemblance of the Tegucigalpa formation (as it was called by Fritzgartner) with the Meta pan terrane [see Chapter XIV, Lower Cretaceous, p. 585], is so great that I was 

unable, in the absence of fossils, to distinguish them. It may therefore well be the case that a 

portion of the Metapan terrane, as shown in the departments of Tegucigalpa and Olancho, 

belongs to the Tegucigalpa formation. 

Mierisch described a series of strata observed in Nicaragua which he was inclined to consider as Triassic and which I have therefore designated in my map accordingly. These are 

beds which in Prinzapolca occur in a horizontal or gently dipping east-west attitude and comprise red fine sandy clays and soft yellowish to white sandstones; soft red sandstones on the 

Cuicuina River; reddish white to white clays and iron-stained sandstones on the Cuculaia 

River; fine-grained reddish sandstones which pass over into loose gravelly marls near Ojoche; 

red sandy clays and gravelly and pebbly strata which are strongly impregnated with iron and 

contain numerous included quartz blocks near La Guardia; red sandstones below Sirena, on 

the Rio Grande; soft red clayey sandstones on the Rio Tuma, on the lower Vas puc; and red 

sandy clays on the Rio Coco near Saki, Quisalaia, and Saclin. These latter occurrences I have 

mapped as Tertiary, since the fiat position of the completely unfossiliferous strata is in such 

contrast to the steeply dipping Mesozoic formations of the middle Rio Coco as to indicate without question a younger age. Having in this region begun to doubt the determination of the 

age by Mierisch, I came to regard his Triassic formation with some question, the more so since 

he rested his correlation only upon petrographic resemblance with the new red sandstone in 

the eastern part of the United States, together with the occurrence of splendidly preserved 

but not very surely determined silicified cycad trunks from the vicinity of Ojoche, as well 

as upon the intimate relationship between these rocks and the melaphyres, porphyry, and 

the associated tuffs. * * * It is true that Mierisch calls attention to the fact that the obviously very young "Tertiary" sands, clays, and gravel beds of Prinzapolca rest unconformably 

upon the Triassic. 

Inasmuch as Sapper in several successive publications implies that Newberry's 

determination of the Rhretic age of the cycads from Honduras should be accepted 

only with doubt, the present compiler referred the question to F. H. Knowlton, 

who under date of December 9, 1910, answered as follows: 

At your request I have again looked over Newberry's paper on "Rhretic plants from 

Honduras" and, without going exhaustively into the subject, I see no reason for seriously 

questioning the correctness of his age determination. Newberry compared this flora with 

others from various parts of the world and found closest agreement with those of southern 

Sweden (Bjuf) and India (Rajamahal). There is also a species very close if not actually identical with one in the Triassic (Rhretic) of North Carolina. 

In this connection I may add that Dr. Arthur Hollick, of New York, happens to be here 

now, and I have asked him about this matter. The specimens upon which Newberry based 

his paper are in the care of Dr. Hollick, and he permits me to say that in his opinion their 

reference to the Rhretic is justified. 

Mierisch 594 states briefly that Triassic rocks occur in Nicaragua. He says: 

The path from Muy-muy to Guardia leads through a swampy savannah, "Jicaral," but 

the district is of geological interest on account of the occurrence of Triassic strata. They 
TRIASSIC. 503 

are red sandy clays, together with highly ferruginous conglomerates containing numerous 

quartz blocks; the latter particularly indicate Triassic age, as they are characteristic of a district north of La Guardia, where the age of this formation is placed beyond question by the 

occurrence of silicified cycad trunks (" Farnstrunke "). 

Regarding rocks on the River Vulvul, Mierisch says: 

Near Ojoche Trias occurs again in the form of a fine-grained red sandstone which is fairly 

firm. * * * At Ojoche it is rather a loose pebbly mass containing many quartz blocks 

and fern trunks, which are superbly preserved. Even the bark and attachments of the roots 

may occasionally be clearly recognized and the internal structure of the wood is retained to 

the most delicate details. These forms probably belong to the genus Tubicaulis. 

The cycads to which Mierisch and Sapper refer were collected by T. H. Leggett 

and sent toN ewberry, who recognized 13 species and assigned them without question 

to the Upper Triassic. Newberry 612• 

613 says: 

From the notes furnished me by Mr. Leggett it appears that the plant beds of San Juancito 

form part of a series of argillaceous shales now converted into hydromica schists several hundred 

feet in thickness. Below these, limestones crop out which are said to contain Carboniferous 

fossils, while above them are heavy masses of eruptive rock. The plant-bearing shales are much 

disturbed and metamorphosed, and are cut by a series of silver-bearing veins which have been 

worked for many years with considerable success. The outcrops which contain the plants are 

much decomposed and few good specimens have been obtained from them, but the number of 

species represented is large and it is evident that further excavation would result in the accumulation of much interesting material. 

The age of the deposit as indicated by its plants is plainly Upper Triassic and the flora as a 

whole has a great resemblance to that of the coal-bearing strata on the Y aki River in Sonora, 

Mexico, described by me in the report of the San Juan expl6ring expedition, and to that described 

by Schenk in "Die fossile Flora der Grenzschichten des Keupers und Lias Frankens" and to 

N athorst's ''Florau vid Bjuf," a number of the species being identical and others closely allied. 

The localities nearest to Honduras where fossils indicative of Triassic age have been before 

discovered were in Sonora, Mexico, 2,000 miles north, and in the Andes of Peru, where Triassic 

rocks were found by David Forbes, 2,000 miles south. The plants contained in the collection 

made by Mr. Leggett are here briefly described. 

D-E 15. CHIAPAS AND GUATEMALA. 

Sapper 694a describes the Todos Santos terrane of Central America as a sequence 

of red or yellow sandy and argillaceous conglomerates, which are but slightly tilted 

and not apparently conformable to the underlying Carboniferous. They are .unfossiliferous but may be Triassic, as similar deposits of that age have been found in 

Honduras and Nicaragua. Sapper says: 

At the northern base of the Sierra Madre in the State of Chiapas one may observe a series of 

puddingstones, sandstones, and shales, of red or yellow color, which I have called the Todos 

Santos strata. The beds are but slightly inclined toward the north at various places where I 

have been able to observe the dip. They do not rest conformably upon the Carboniferous limestone, and it appears that these deposits were laid down after the formation of the first elevation 

of the Sierra Madre in the margins of a sea later than the Carboniferous but before the Cretaceous, 

so that they suffered but little dislocation or alteration. 

I can not give any exact data in relation to the age of these strata, as I have not found any 

fossils in them. There are very similar deposits of the Triassic period which have been found in 

the Republics of Honduras and Nicaragua. 
504 INDEX TO THE STRATIGRAPHY OF NORTH JU1ERICA. 

In a later article 698 Sapper stated that he had not been able to observe the contact of the Todos Santos beds with the underlying Carboniferous and could not be 

sure that the two were unconformable, although that conclusion was probably correct. 

Bose 90 in 1906 repeats Sapper's description and adds that the Todos Santos 

strata appear to belong to ti1e "Triassic-Jurassic," as they are similar in position and 

lithologic character to strata of those ages which are known in other parts of Mexico 

(Puebla and Oaxaca) and also in Honduras. 

E-F 14. CENTRAL AND NORTHERN MEXICO. 

Aguilera 9a in 1906 thus summed up the occurrences of the Triassic in central 

and northern Mexico under the heading "N eo-Triassic" : 

Marine deposits of the Carnien stage are represented in the vicinity of the city of Zacatecas 

by siliceous shales and argillaceous and sandy rocks which contain a number of species of 

Paleoneilo, I-Ialobia, Avicula, Cassianella (Burckhardtia), and some ammonites: Serenites 

smithi Burckh., Anatomites mosjvari Burckhardt, Clionites, and Trachyceras. The Triassic beds 

of Zacatecas are intimately associated with spilitic rocks (greenstones). We may mention in 

the same connection the marsh and lacustrine deposits of Juravien age which correspond probably 

to the Keuper and extend up to the Rhretic. They are composed of quartzose sandstones of 

gray or reddish-brown color, gray, black or varicolored slates, and some beds of red conglomerates with small pebbles in the region of Los Bronches, at the Barranca of San Marcial and San 

Jose de Pimas in Sonora. 

A list of fossils comprising 30 species follows, and Aguilera continues: 

Conglomerates and red sandstones which alternate with gray and black slates and which, 

inasmuch as they include fossil plants of the same genera and species as those of Los Bronches, 

are of the same age, have been found in Puebla and Oaxaca, and probably also beneath the beds 

of Miquihuana, in Tamaulipas. 

In the geologic map of North America the occurrences of the Triassic in central 

and northern Mexico have generally been mapped with the Jurassic in accordance 

with the manuscript map furnished by the Mexican Survey. (See also quotations 

under Jurassic in Chapter XIII.) 

The Triassic of Zacatecas was described by Burckhardt and Scalia. 111 After 

describing ancient sericitic schists, whose age they say is probably pre-Triassic, 

as they are unconformably overlain by beds of the upper Triassic, the authors 

continue: 

The upper Triassic strata rest in discordance upon the ancient schists forming the central 

portions of the two recumbent synclines that are open toward the east and which may be observed 

in the valley of the Pimienta. The existence of these synclines is proved by the arrangement of 

two bands of Triassic strata intercalated in the ancient schists. One may observe quartzites 

and quartzitic sandstones of dark-gray color containing fragments of quartz and feldspar in the 

center of the two Triassic occurrences, while these rocks are limited on both sides by quite a 

thickness of siliceous and argillaceous schists which are black or dark blue and alternate with 

green sandstones and greenish or gray argillites. All of these rocks dip toward the east. * * * 

The Triassic fossils occur in two different localities; the first is situated close to the point where 

the Arroyo Calavera or Pimienta is crossed by a bridge, the bridge of Ahogado. At that point, 

in the northern flank of the eastern syncline of the Trias, fossils occur in the black siliceous slates 

as well as in a gray argillaceous rock. These beds are filled with fossils, especi-ally with small 

bivalves, while ammonites are rare and fragmentary. 
TRIASSIC. 505 

The fossils that were collected at this point were independently determined by 

Mojsisovics and J. P. Smith as belonging probably to the Carnien stage of the 

Upper Triassic of Europe. A second collection of fossils was obtained in greenish 

sandstones and argillaceous rocks in the western syncline of the Triassic. The 

authors continue: 

It is proved by the discovery of these fossils that the upper part of the slates of Zacatecas 

belong to the upper marine Trias. 

A full description of the fauna is given by Burckhardt. 108 

I 11. SOUTHERN CALIFORNIA. 

The several areas of Triassic rocks southeast of Los Angeles are described by 

W. C. Mendenhall for this report as follows: 

The Santa Ana Mountains, usually regarded as a southern extension of the Coast Ranges, 

form a portion of the boundary between Riverside and Orange counties in southern California. 

The group, which lies for the most part south of the lower course of Santa Ana River and west 

of the Temescal Wash, culminates in Santiago Peak, 5,680 feet high. Its axis is made up of a 

series of dark-gray or black slates with minor amounts of interbedded brown sandstones, the 

whole sparingly intruded by a series of medium acidic dikes and overlain unconformably by 

remnants of the associated effusives whose aspect is generally that of andesites or slightly more 

acidic rocks. 

The slates exhibit varying degrees of metamorphism. They usually have a well-developed 

cleavage, which, however, is generally not sufficiently perfect to obscure the original bedding 

planes. In general appearance they resemble the Mariposa slate of central California, although 

as a rule they are less extensively altered. These sediments are the oldest rocks of the mountain 

range in which they occur. The effusives already mentioned overlie the slates but have been 

affected by a part of the same metamorphism. 

Both the sediments and the associated effusives have been intruded and slightly altered 

by great masses of granitic rocks, and this threefold series after a long time interval, represented 

by an extensive physical unconformity, has been at least partly buried under Cretaceous conglomerates and shales of Chico aspect that are now entirely unaltered though extensively 

deformed. These Upper Cretaceous rocks form an encircling outcrop that flanks the dome of 

older rocks. 

The determination of the age of the slates is based on small collections made in Ladd 

Canyon, on the south slope of the range, and near the mouth of Bedford Canyon, on its north 

slope. These collections were examined by Dr. Stanton, who reports as follows on the Bedford 

Canyon collection: 

''The two Triassic lots, both from the neighborhood of Bedford Canyon, evidently came 

from essentially the same horizon. No. 230 contains fine specimens of a large species of 

Rhynchonella of a Mesozoic type and a single specimen of Spiriferina. No. 321 contains the 

same species as 230 and in addition a plicate form of Terebratula and fragments of crinoid 

stems. These fossils taken together clearly indicate the Triassic age of the fauna, but in the 

absence of ammonites and other diagnostic forms it is not possible to determine the exact 

horizon, although it is probably Upper Triassic rather than older." 

Thus the collections, although' meager, seem abundantly sufficient to establish the Triassic 

age of the slates. Accepting this age, then, as determined, we must assign the later granitic 

intrusions to the Jurassic or the early Cretaceous. 

The Triassic beds probably extend considerably beyond the area in the Santa Ana Mountains where they have been carefully examined. Similar beds are known to occur in Railroad 

Canyon between Elsinore and Perris, and fragmental masses of them apparently caught up in 
506 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

the widespread granitic intrusions of the area occur farther east in the vicinity of Poloma and 

Los Alamos valleys, in Riverside County. 

I 13-14. EASTERN NEW MEXICO AND WESTERN TEXAS. 

The Triassic of eastern New Mexico occurs in the escarpment along the valley 

of Canadian River, and prolu,bly elsewhere as the uppermost part of the red beds 

beneath strata which are believed t0 represent the Morrison formation (,Jurassic or 

Cretaceous). The strata are 100 to 200 feet thick and are sandstones of reddish 

color with lighter-colored balls of clay.a Triassic vertebrate remains have been 

found by Stanton 781b near Folsom and by Lee 528 • at a point southeast of 

Tucumcari. 

The original section of Mount Tucumcari ("Pyramid Mountain") wa>; observed 

by Marcou and is thus described by Blake: 85 

Pyramid Mountain.~The finest and most complete section of the horizontal strata of the 

bluffs along the route was obtained at this mountain by Mr. Marcou. The point was peculiarly 

favorable, being one of the isolated mounds, a remnant of the Llano, and exposing the strata on 

all sides. It is only one of the many mounds dotted over the wide space eroded by the river 

from the Llano, and called Plaza Larga by the Mexicans. This mound was ascended by Mr. 

Marcou, and others of the party, and we find the following record of the succession of the strata 

in the notes under date of September 22: 

Section at Pyramid Mountain. 

"Jurassic:" 

White limestone. 

Yellow limestone with bluish-gray bed at the bottom. 

Bed containing Ostrea --(?).b 

White sandstone. 

Yellow sandstone. 

White sandstone. 

"Triassic: " 

Gray and green bed in contact with the superior Trias. 

Red and green sandstone. 

White marls with concretions. 

Red and green marls. 

White. 

Red. 

[Thickness,] 500 feet. 

Mr. Marcou considers that the base of this mound is formed of the beds of the superior 

Trias, the upper portwn being Jurassic. It does not appear to me that the evidences are quite 

sufficient to warrant this decision, but the discussion of this subject will be left for a subsequent 

portion of the report. 

A sketch of this mound was carefully taken in colors by Mr. Mollhausen, the tints agreeing 

as nearly as possible with those presented by the strata. The sketch has been lithographed 

and is appended. It will serve to convey an idea of the relations of the strata, especially the 

white and red series, and may be received as an exhibit of the general aspect of the bluffs of 

the Llano, where the beds are exposed. The section and locality derives great interest from 

the occurrence of fossils. The bed containing the Ostrea is said to be of grayish-blue clay and 

subschistose, and 2 inches thick. The Ostrea is subsequently called Ostrea dilatata, and is 

again mentioned in the resume. This is the fossil called Gryphcea tucumcarii in the collection 

(No. 133) from Pyramid Mountain, and referred to in the resume under the same name, it 

a Lee, \V. T., personal communication. 

b The specific name can not be deciphered in the original. It looks like comanche.-W. P. B. 
TRIASSIC. 507 

being said to have the greatest analogy with the Gryphr£a dilatata of the Oxford clay. a It is 

probably a new species or a variety of Gryphr£a pitcheri, and a description of it will be found in 

Chapter IX, under the name G. tucumcarii, originally proposed by Mr. Marcou. 

From t.hese various observations we may conclude that the great plateau, the Llano 

Estacado, consists of horizontal strata of light-colored white or grayish-white and yellowish 

sandstone's and bluish clays and marls, resting conformably upon beds of red clay, red sandstone, and gypsum, and these, according to 1\fr. Marcou, are intercalated with grayish or lightcolored sandstones, as on Rocky Delaware Creek. It nlso appears that the light-colored sandstones and calcareous beds constitute the main part of the bluffs and that the red marls and 

clay of the gypseous series are at their base and occupy the space bctwcPn them and the river. 

The strata assigned to the .Jurassic by 1\farcou were by Cummins 197 shown to 

be Lower Cretaceous. The Triassic age of the lower part of the section is neither 

proved nor disproved. The strata beneath the Cretaceous may be Triassic, or they 

may be older red beds (Permian or Pennsylvanian) from which the Triassic beds 

were eroded. 

In western Texas Cummins distinguished and Drake 293 described the Dockum 

group, of Triassic age, a sequence of calcareous sandstone, clay, cross-bedded 

sandstone, and conglomerate, deposited on an eroded surface of Permian. Drake 

recognized three divisions, which he described in detail. 

The Dockum beds underlie all or nearly all of the Staked Plains of Texas and southeastern 

New Mexico, extend farther back into New Mexico northwest of the plains, and have some 

extension under the Cretaceous area so.uth of them in Texas. 

The limit of the plains on the east, north, and west is marked by an escarpment which -is 

usually from 100 to 200 and sometimes 300 or 400 feet high. The basal portion, sometimes 

nearly all of this escarpment, is composed of the Triassic beds. These beds usually extend 

6 or 7 miles from the base of the escarpment and nearly surround the plains by a narrow band. 

* * * * * * * * * Sandstones, conglomerates, and clays constitute nearly all of the strata of this formation. 

The materials composing the di:ITererit strata vary somewhat in lithological characteristics 

at different localities and even at the same locality, but the general characteristics are quite uniform and are so different from the underlying Permian and overlying Cretaceous or Tertiary that 

they are usually easily recognized. This is especially true of the sandstones and conglomerates. 

Sandstones.-The sandstones before exposure to weather are generally nearly white, but 

sometimes gray, red, or bluish in color. :Massive, shaly, and false bedding are common. The 

texture varies from a fine, even-grained to a grit or conglomeratic sandstone. White and a few 

brown mica flakes, varying in size from a mere speck to one-eighth of an inch in diameter, 

are nearly always present. This mica is so abundant in some of the rocks as to make them 

fissile. The sandstones are usually friable but weather with a smooth, flat surface and with an 

average sharpness of angle for sandstone rocks. 

Oonglomerates.-The conglomerates are of two kinds. The one most characteristic and widespread is composed of small pieces of brownish, yellowish, or bluish colored subangular 

indurated clayey sandstone fragments, averaging about the size of a pea, embedded in a matrix 

of sand or grit, usually calcareous. The other is composed of siliceous pebbles in a matrix of 

sand and grit. The pebbles are usually small and well rounded and of nearly all shades of color, 

but white quartz are the most numerous. The quantity of siliceous pebbles varies at different 

loca:ities from more than half the rock mass to very few. Both conglomerates contain silicified 

wood at some localities. The bedding of the siliceous conglomerate is usually even and regular 

or slightly false, while that of the first named is false almost without exception. These two 

conglomerates graduate into each other, and even where one is the most characteristic the other 

usually enters into it more or less. -----------------·--····. 

a The genus Gryphrea was formerly included with the Ostracea. 
508 INDEX TO THE STRATIGRAPHY OF NORTH ~\1ERICA. 

Clays.-The clays are a dark red or blue, with some variations of yellowish and purple, 

and are calcareous and arenaceous. The blue clays are not very common, are nearly always 

highly arenaceous, and frequently contain vertebrate remains. The red clays are seen at nearly 

every outcrop and are often more than 100 feet thick, with probably a few thin layers of sandstone distributed through the strata. 

Thickness and uncoriformability.-The slight difference in dip and sudden change in litho-. 

logical character of the Triassic beds from the Permian point conclusively to a break in the 

sedimentation of the two formations. At some localities the Triassic beds are overlain by 

Cretaceous, but generally by Tertiary material. The Cretaceous escarpment or butts resting 

on the Triassic beds are often 200 feet thick and mostly limestone. The denuding forces that 

for an immense length of time were cutting these Cretaceous rocks back toward their present 

limits must have carried away a great deal of the Triassic before it was covered by Tertiary. 

The strata thus inclosed between two unconformable beds must of necessity vary in thickness, 

.and so we find it varying from a few feet to nearly 400 feet. Even in localities close together 

the beds vary considerably in thickness. The average, however, will probably )each 200 feet. 

Stratigraphy.-The. following classification or grouping is not intended as a correlation 

with any other Triassic beds, but only to apply to the Dockum beds over the area examined. 

The Dockum may be divided into three beds, though some localities show more, that are more 

or less well marked. * * * These three main beds are as follows: A lower bed of sandy 

clay, which is from 0 to 150 feet thick; a central bed or beds of sandstone, conglomerate, and 

some sandy clay, which is from 0 to 235 feet thick; an upper bed of sandy clay and some sandstone, which is from 0 to 300 feet thick. While these groups represent the different geological 

horizons over most of the Triassic area, there is nevertheless at some places a thinning out of 

one, and a thickening of another, which shows that at the same time the conditions of deposition 

were somewhat different at different localities. The same geological horizon is, therefore, more . 

or less represented in other beds than that which generally 'represents it. Then, while these 

three beds do not absolutely represent geological horizons, they do so approximately and are so 

well marked as to be of much stratigraphical value. 

These strata are fresh-water deposits and their age is determined on vertebrate 

remains by Cope. 

1-J 17. NORTH CAROLINA. 

Kerr 489 thus described the rocks of the Dan and Deep River belts, the Triassic 

of North Carolina : 

The rocks arc sandstones, day slates, shales, and conglomerates, generally ferruginous 

and brick-red, but often gray and drab. The shales are occasionally marly, and these and the 

sandstones are sometimes saliferous. Many of the beds consist of loose and uncompacted 

materials and are therefore easily abraded. 

The most important and conspicuous member of the series is a large body of black shales, 

which incloses seams of bituminous coal, 2 to 6 feet. This co allies near the base of the system 

in both belts and is underlain on Dan River by shales and on Deep River by sandstones and 

conglomerates, tho latter constituting the lowest number of the series and being in places very 

coarse. And near the eastern margin in Wake County, where the belt reaches its greatest 

breadth (some 15 miles), the conglomerates are of great thickness and very coarse, uncompacted and rudely stratified, resembling somewhat the half-stratified drift of the mountain 

slopes, the fragments often little worn and sometimes 10 and 12 inches in diameter, and evidently derived from the Huronian rocks of the hills to the eastward. The conglomerates of the 

Dan River belt are among the upper members of the series and are mostly fine and graduate 

into grits and sandstones. 

The black shales near the base of the system contain beds of fire clay and black-band iron 

ore, interstratified with the coal. They are also highly fossiliferous, especially on Deep River. 

Silicified trunks of trees are very abundant in the lower sandstones, as may be seen conspicu-
TRIASSIC. 509 

ously near Germanton, in Stokes County, the public road being in a measure obstructed by the 

multitude of fragments and entire trunks and projecting stumps of a petrified Triassic forest; 

and similar petrifactions are abundant in the Deep River belt, occurring in this, as in the other, 

among the sandstones near the horizon of the coal. 

The Triassic coal-bearing terrane of North Carolina has also been described by 

Woodworth,949 as follows: 

There are two coal-bearing Triassic areas in North Carolina. These are the eastern or 

Deep River area, including the Wadesboro detached area, and the western or Dan River area. 

The principal productive coal beds are found in the Deep River district, in Chatham and Moore 

counties. The Dan River region is regarded as of little promise. * * * 

The Deep River area forms a northeast-southwest belt in the central portion of the State, 

extending northward nearly to the Virginia line and southward into South Carolina. The 

productive area, about 30 miles long, lies wholly within North Carolina. 

The rocks of the area appear on the north about 6 miles southeast of Oxford, in Granville 

County, whence they extend southwestward to the Cape Fear River. South of this stream 

they continue as a somewhat tortuous belt in the Deep River region to within about 10 miles 

.of the Y adkin River. On the Yadkin, and a few miles west of the southern end of the Deep 

River area proper, the Wadesboro area begins and extends in the same general direction 6 or 7 

miles into South Carolina, in the vicinity of Carew. The total length of the whole belt is over 

60 miles. Its average width is about 12 miles, its greatest width being as much as 18 miles . 

.rr'he total area has been estimated at between 250 and 300 square miles. Between the larger 

northern and southern areas are small detached basins of Triassic rocks not known to be coal 

bearing. 

The area displays the prevailing structure of the Triassic belts along the Atlantic coast, 

the basal strata of one side of the belt reposing on the ancient crystalline rocks of the Piedmont 

district, the opposite margin bearing evidence of being thrown down by faults. The usual 

dip of the strata in this area is southeast, the angle being about 15°. According to Russell, 

the notches in the boundaries probably indicate faults, several of which are exposed in railroad 

cuts within the area. Evidence of faulting is also seen in the narrow strip of Triassic strata 

near the western border, in the vicinity of Lockville. 

The coal-bearing beds show a distinct curvature where crossed by the Deep River northeast 

of Cummocks. In other respects the structure, as revealed in workings, appears to be more 

regular than that of the Richmond area in Virginia. 

The strata, numbered from the bottom upward, are given as follows in the State reports: 

Strata in Deep River area, North Carolina. 

Feet. 

3. Sandstones, grits, and upper conglomerates ............................................. 3, 000 

2. Black shales, with coal beds ....................................................... 500 to 600 

1. Conglomerates and sandstones .......................................................... 1, 500 

As in the Richmond and other Triassic areas, the coal beds are near the base of theN ewark 

formation. * * * 

Five coal seams have been proved at the Farmville and Hornesville mines. Their thicknesses, beginning with the highest, are given as 3, 1, 3, 2, and 4 feet. At the Cunnock mine 

there are two beds, one 4 and the other 2 feet in thickness, separated by 2 feet of black-band 

iron ore. At Taylor's mines three seams were reported, with a thickness of from 18 to 30 

inches, 2.5 to 2 feet, and 4 feet, respectively. At Wilcox's the Murchison seam is described 

as being 8 or 9 feet thick but containing shale. The coal outcrop has been traced for 30 or 40 

miles in the central part of the State southwestward from the vicinity of the Cape Fear River. 

Chance a found at Farmville, N. C., five beds of coal in the following section, which measured 40 to 50 feet from the roof of the uppermost coal bed to the floor of the lowest. 

a Trans. Am. Inst. Min. Eng., vol. 13, pp. 517-520. 
510 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Slate roof. 

Section of coal beds at Farmville, N. 0. 

Coal, good......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 feet to 3 feet 2 inches. 

Black band and slate ...................................................• 1 foot 8 inches to 3 feet. 

Coal, poor, shaly ................................................................ 1 foot to 2 feet. 

Pure clay floor. 

I-K 12-13. UTAH, COLORADO, NEW MEXICO, AND ARIZONA. 

Along the fortieth parallel so-called Triassic rocks were originally distinguished 

by King and his associates, 505d whose observations are thus summed up: 

In the region of the Rocky Mountains we have seen that the Trias frequently overlaps 

the older rocks and comes directly into nonconformable contact with the great Archean islands 

that now form the three ranges of the Rocky Mountain system in our latitude. The Trias is 

in general a series of sandstones; the upper half is always of lighter colors than the lower half 

and is always intercalated more or less with beds of dolomitic limestone and gypsum. The 

series varies from 300 to 1,000 feet in thickness. Wherever it stands at a high dip, it is most 

compressed in thickness and most compacted in lithological character. Wherever its position 

approaches horizontality, the texture of the rock is that of a loose, friable sediment. The 

lower half of the series is usually from brick to vermilion red and buff, with occasional exceptions of white and brilliant vermilion. The intercalated dolomitic and gypsum beds are never 

continuous but are shallow deposits of no great lateral extension. On approaching the Archean 

rocks the Trias have always more or less local conglomerates, derived directly from the shores 

against which they abut. There is considerable variability in color, in thickness, and in special 

arrangement and sequence of the sediments. From 1,000 feet maximum in the region of the 

Rocky Mountains the deposit thickens in passing westward, until, in the neighbmhood of the 

·eastern part of the Uinta, it is fully 2,000 to 2,500 feet thic.k. The division between the lower 

dark-red member and the upper buff or white member is much more distinct in the Uinta 

region than to the east. Here, however, are still the intercalated gypsums and dolbmites 

in the upper half of the series, the gypsum sometimes reaching 40 feet of pure white crystalline 

sulphate. There are also in the Uinta considerable intercalations of clayey matter, which 

are rare in Colorado. 

Passing still farther westward, against the W ahsatch, there is again a noticeable diminution of thickness and a corresponding increase of stony compactness. Under the microscope 

no single specimen was observed that had not a considerable amount of carbon and a trace 

of crystals of carbonate of lime. In approaching the W ahsatch, also, there. is a considerable 

increase of conglomerates. This constitutes another argument indicating the approach of 

a land mass to the west, whence detritus is derived. But one fossil, a new species, was found 

in the entire Triassic series of the east, and that was obtained from one of the limestone bedsa greenish-drab lithographic limestone-a little above the middle of the series, on the south 

flank of the Uinta. That fossil had a distinctly upper Triassic or Jurassic facies. The upper 

horizons, especially the uppermost member of all, varying from 200 feet in Colorado to 600 in 

the Uinta and sometimes more than that upon the flanks of the Wahsatch, is characterized by 

remarkable cross stratification which is prominent over most of the exposed area east of the 

Wahsatch. The flow and plunge structure is developed in a perfection rarely seen, the plane 

of the cross stratification often inclining to the true bedding planes at an angle of 30° to 35°. 

The upper half, bearing irregular sheets of gypsum and of dolomitic limestone, is always 

directly conformably overlain by the Jurassic beds, which, when first seen on the east flank 

of Colorado Range, vary from 250 to 275 feet in thickness, and increase steadily until on the 

flanks of the Wahsatch they have reached fully 1,800 feet. There is a very great physical 

contrast between the general character of the materials of the Triassic and the Jurassic series. 

The former is, on the whole, free from lime, except in the sulphate and dolomitic beds, and 

is with the exception of certain parts of the Uinta rather free from intercalated clays. On the 

other hand, the Jurassic, in the Rocky Mountain region, is entirely made up of soft clays; 

argillaceous and calcareous marls, and thin intercalations of fine lithographic limestone. In 
TRIASSIC. 511 

the Uinta and W ahsatch region the lower 600 or 800 feet are a bed of solid but very fine 

grained, slightly argillaceous limestone, and the upper 800 feet are made of fine calcareous 

argillites. As a whole the series is a lime and clay deposit. 

Later observations have shown that part of the supposed Triassic is Permian, 

some part is Triassic, there are pre-Jurassic unconformities, and the Triassic and 

Permian deposits which were considered to be marine are in fact largely continental. 

Cross has recently reviewed the literature and field evidence of this red-beds problem. His statements regarding the probable correlation and distribution of the 

Permian have been quoted at some length (pp. 480-484), and extracts from those 

relating to the Triassic follow. The San Juan district of southwestern Colorado 

is the type locality of the Dolores formation (Triassic). Of this region Cross 193a 

writes: 

The Dolores formation embraces the Triassic portion of the red beds of southwestern 

Colorado, several hundred feet in thickness. It is limited both above and below by planes of 

unconformity. In most places it rests on the Cutler formation [Permian?] and is overlain 

by the La Plata sandstone [Jurassic]. It consists of sandstones, shales, and fine-grained conglomerates, all more or less calcareous. There are two divisions of the formation; the lower 

embraces variable sandstones, conglomerates, and shales, partly greenish or gray in color and 

persistently fossiliferous at several horizons; the upper portion is a very fine and evenly grained 

sandstone and shale of strong red color. 

The lower portion of the Dolores formation consists of an alternation of reddish sandstones, 

more or less shaly, with conglomerate, consisting chiefly of very small limestone pebbles. 

These conglomerates characterize several bands within the lower 300 or 400 feet of the Dolores, 

and, owing to their fossil content and notable lithologic characteristics, these beds are the 

most diagnostic of the whole formation. The conglomerate beds are very variable in number. 

In some places a ledge 20 feet thick may be seen to consist chiefly of conglomerate with numerous 

sandy partings and common cross-bedding. A few yards distant the same strata may be composed chiefly of sandstone with a number of thin layers of conglomerate. 

* * * * * * * * * 

The conglomerates are commonly associated with thin-bedded gray sandstones or greenishgray sandy shales. A complex of such alternating strata 50 to 75 feet in thickness can be 

traced for long distances on the flanks of the San Juan Mountains. Carbonaceous material 

is cc;mmon in the shaly beds, but determinable leaves have not been observed. The lowest 

stratum of the Dolores is generally more or less conglomeratic and in some localities is a harder 

stratum, forming distinct ledge outcrops. The thickness of the lower division of the Dolores 

seems to vary considerably, increasing from the mountains west and southwest toward the 

plateau country. 

The upper member of the Dolores is commonly a very even fine-grained reddish sandstone, 

free from conf-,lomerate but variably shaly in different places. The shales are, however, 

always very sandy and there are seldom pronounced division planes of great lateral extent. 

The bands of parallel massive sandstone are often 20 feet or more in thickness. The material 

is mainly quartz sand, with a calcareous cement. In color this upper sandstone is usually 

bright brick-red or vermilion, shading sometimes into purplish above and a dull darker red 

below. In texture this red sandstone is very much like the overlying La Plata sandstone, and 

where the latter is highly colored the two formations seem sometimes inseparable, but the 

La Plata is commonly orange or yellow in color when it departs from the normal gray or white. 

The upper member of the Dolores is absent in the Ouray and parts of the Telluride quadrangles but presents an increasing thickness southward through the Rico and La Plata quadrangles. Nearly 500 feet of quite uniform sandstones were observed on the eastern flanks 

of the La Platas. The variation in thickness and the disappearance of the red sandstones 

to the north is due chiefly to the post-Dolores erosion. 
512 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The limestone conglomerates of the lower Dolores contain scanty but very widely distributed fragments of bones and teeth belonging to vertebrate animals. Much less frequently 

invertebrate and plant remains of identifiable character occur in the same strata. The vertebrate remains have never been found as connected skeletons, or even closely associated bones 

belonging to one individual. They are usually worn and often broken. The most common 

fossils are the teeth of crocodiles and dinosaurs. Material collected from many localities has 

been studied by F. A. Lucas. The greater number of the remains belong to the belodont 

crocodiles, while less numerous are those belonging to a megalosauroid dinosaur, perhaps 

Pala:octonus of Cope. It is probable that the belodont remains belong to the genus described 

by Lucas under the name Ileterodontosuchus ganei, or to allied forms. Poorly preserved outlines of Unio have been seen in several places and a small gastropod shell has been found in the 

Rico and La Plata quadrangles. According to Stanton, the latter belongs to the genus Viviparus 

or to a closely allied form. 

Tracing the various strata from the San .Juan district west and north in the 

plateau country, through the work of Peale and Spencer, Cross 1930 identifies the 

Dolores formation in the Dolores, San Miguel, and Sinbad valleys. 

Below the La Plata, distinguished by Spencer, there occurs a much deeper red sandstone 

formation, vermilion or brick-red in hue and corresponding to the upper division of the Dolores 

as it has been described in this paper. Apparently the lower part, characterized near the San 

Juan Mountains by the variable strata carrying fossiliferous limestone conglomerate, is not, 

on the Dolores, markedly different from the upper in texture or color. Spencer has found 

limestone conglomerate rich in bone fragments in several places, and on La Sal Creek this 

horizon was but about 100 feet below the La Plata sandstone. The total thickness of the 

nearly uniform Dolores formation is about 1,000 feet in the neighborhood of Sinbad Valley, 

while much less in other localities. 

Over certain area,s of the Uncompahgre Plateau in western Colorado the 

Triassic is lacking, probably in consequence of pre-Jurassic erosion. 193d Northwest 

of Grand River in Utah, however, the strata appear with the characteristics of the 

Dolores formation. Cross 1890 gives the following section measured by W. H. 

Emmons and L. H. Woolsey: 

Section near Grand River, opposite Moab, Utah. 

Top Feet. 

32. Sandstone, massive or shaly, dark red at base and bright red at top. _________________________ -_ 20 

31. Shaly, conglomeratic sandstone, reddish limestone pebbles, the size of a pea or smaller, with 

few bone fragments ... ________ -______ - . ________ ----------- ______ ------------- ____ ------- 6 

Dolores Triassic. 

30. Sandy shale, red and green .... --------_- ________ ----------- __ . ___ -----·------- _____ ------ 5 

29. Debris slope, of red shale fragments. --- __________________________ - ___ --------- ____ ------- 20 

28. Limestone conglomerate, with a few inches of limestone at top, fossil wood, and bone fragments; pebbles less than 2 inches diameter _____________________________________________ 10 

27. Sandstone, gray, massive. ____________ -- ... __ . ___ -._- __________ .. _ .. __ .- ..... --_ .. _-.-.- .. 20 

26. Limestone conglomerate grading into sandstone .. ------ ____________________ ----- _____ -_--.- 1~ 

25. Sandstone, gray, massive becoming shaly near top. ______________ ... _ ..... _ ... _ ....... _ .. _._ 23 

24. Calcareous sandstone and fine-grained conglomerate mainly sandy, with conglomerate near 

base and top. Pebbles of limestone and sandstone with occasional bone fragments; pebbles 

vary from size of peas to several inches .... _ ... _- .. - . -.---- _ .. ___ -.. -.. -.-.- ........ -.-.- 9 

Permian (?). 

23. Red sandy shales, alternating with sandstone. ____ ._ ........ -_ .. _._--.-.- ....... _. __ -.... -- 8 

22. Conglomerate, containing pebbles of limestone and sandstone._ .. _ .... _-- .. -_._ .... _ ... -.-.- 1 

21. Sandstone and shale alt<:Jrnating, red and green, the shales sandy and friable.- .. - ___ .- ... --- 35 

Hermosa Pennsylvanian. 

20. Blue limestone, weathering dirty buff, near top a layer contains pipe coraL-----.. ___ .. -.---.. 10 
TRIASSIC. 513 

In the S:1n Juan Valley, in southeastern Utah, the La Plata sand"ltone (Juras.:lic) 

as identified by Gane is in part red and has been mistaken for Triassic. It is 

underlain by the fossiliferous limestone conglomerate of the Dolores formation 

(Triassic). 193e 

The Zuni Plateau, in western New Mexico, comprises Permian, Triassic, and 

Jurassic strata, according to Dutton.301a Cross 139g comments on Dutton's divisions 

and find8 correlatives with the formations distinguished in Colorado. 

Comparing the formations of the Zuni Plateau, as described by Dutton, with those of 

southwestern Colorado, it seems probable that the Zuni sandstones represent the Gunnison 

group. Dutton's section is not sufficiently detailed to permit a suggestion as to the exact 

equivalents of the La Plata and McElmo formations, but it is difficult for me to suppose that 

the Navajo Church is constituted of anything but one of the La Plata sandstone members. 

The Wingate sandstone corresponds in position and character to the upper, vermilioncolored sandstone of the Dolores formation. The absence or subordination of cross-bedding 

and the constancy of the red color both tend to support such a correlation. If the Wingate is 

upper Dolores, it would appear probable that the "lower Triassic" of Dutton is at least approximately the equivalent of the lower Dolores, and it may well be that the basal conglomerate 

called the Shinarump by Dutton is actually the same as the basal conglomerate of the Doiores. 

Dutton does not speak of limestone conglomerates in the Trias, nor did he find fossil remains 

in it, except the abundant fossil wood. 

Regarding northeastern Arizona, Cross 193h says : 

From the Zuni Plateau a wide tract of upland stretches for 150 miles or more northwest 

to the brink of the Colorado Canyon. On the northeast is the San Juan Valley and on the 

southwest is the Little Colorado. It is the land of the .Moqui and theN avajo Indians. Beneath 

the Eocene and Cretaceous strata of the higher central plateau appear the Jurassic and Triassic 

beds, the character of which on the San Juan side has already been considered. That the same 

systems are represented continuously from the Little Colorado to the Zuni Plateau was long ago 

ascertained by Newberry, though definite evidence of the Triassic age of any particular strata 

has been but recently brought to light. 

In the paragraphs following the one just· quoted Cross refers to vertebrate 

fos"lils from northeastern Arizona which had been identified by Lucas.551• 552 The 

stratigraphic data relating to this area are taken from Ward, 865 and concerning 

them Cross 193; says: 

The vertebrate fauna discovered by vVard occurs near the middle of a section some 3,500 

feet in thickness, all of which is atJsigned to the Trias. vV ard divides this section into three parts. 

At the base arc the ".Moencopl.e beds," 700 feet in thickness' consisting chiefly of dark reddishbrown soft laminated argillaceous shales, nearly destitute of silica (quartz), highly charged with 

salt and gypsum. Some calcareous beds grade into white impure limestone. No fossils were 

found in the Moencopie beds, and vVard states that "the whole series, wherever the contact can 

be found, always rests in marked unconformity upon the underlying Paleozoic rock (Upper 

Aubrey)." 

* * * * * * * * * Succeeding the .Moencopie come 1,600 feet of variable strata called by Ward the Shinarump. 

Within this he distinguishes two formations, each 800 feet thick, the lower being the "Shinarump conglomerate" and the upper the "Le Roux beds." 

The Shinarump conglomerate of Ward is by no means all conglomeratic. His concise 

characterization is as follows: "Conglomerates and coarse cross-bedded sandstones, with clay 

lem;es interstratified with gray argillaceous shales and variegated marls." In fact, the marls 

become locally most prominent in zones which are elsewhere strongly conglomeratic. 

48011°--12----33 
514 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The Le Roux beds are principally variegated marls, argillaceous and calcareous, followed 

upward by sandstone, limestone, with flint fragments, and at the top more calcareous marls. 

Fossil wood occurs all through the Shinarump group and none is found beyond it. The 

petrified forests occur within the Le Roux beds and the vertebrate remains were only found in 

these strata. Bones and fossil wood were found together in many places. 

The "Painted Desert beds" of Ward follow the Le Roux beds and consist of sandstones. 

The lowest stratum, 100 feet thick, is soft, friable, highly argillaceous, and of orange color. 

Above this come 800 feet of variegated sandstones, regularly stratified and brilliantly colored. 

Brown cross-bedded sandstones (200 feet) and white massive sandstones (100 feet) form the 

top of the section studied. 

No doubt the Shinarump group of Ward is in a large degree equivalent to the Shinarump 

of Powell, Dutton, and others, as developed in the plateau country of Utah, and the vertebrate 

fauna of the Le Roux beds serves to correlate them with the lower Dolores strata containing the 

same fauna; but until the unconformity reported by Ward at the base of the Moen co pie beds 

has been traced sufficiently to demonstrate the importance of the stratigraphic break it indicates, 

further correlation of the Moencopie strata is difficult. It is reasonable to suppose that the 

base of the Moencopie is actually the base of the Triassic section and that deposition began in 

Arizona much earlier than in southwestern Colo1.·ado. On the other hand, it may be that the 

belodont fauna will be found at horizons lower than the base of the Le Roux beds. If the 

Moencopie beds are Triassic the ·stratigraphic break below them accounts for the absence of 

strata equivalent to the Permian of Kanab Valley found by Walcott. * * * 

The lower 900 feet of the Painted Desert beds of Ward may plausibly be referred to· the 

Vermilion Cliff or upper Dolores sandstone, while the brown and white sandstones above probably 

represent a part of the White Cliff or the La Plata sandstone. 

A detailed description of these formations is given by Ward. 866a 

In northern Arizona and southern Utah Permian and Triassic strata are separated by an unconformity as determined by Walcott. 844 (See p. 484.) Cross 193i 

gives a detailed section by Walcott of the Jurassic and Triassic of this region, which 

may be summarized as follows: 

Section of Jurassic and Triassic formations in the Kanab Valley, Utah. 

White and red sandstone and shale, more or less gypsiferous with a variable conglomerate bed Feet. 

(1-7).................. ... . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . .. . . . . . 745 

Magnesian limestone intercalated with sandy shale, fossiliferous near the top (8-12).. .... .. .... 215 

White Cliff sandstone (13)........ .... . . . . . . . . .. .. . . . . . .. .. . .. . .. . . .. . .. .. .. . .. .. . . . . . .. . . . 585 

Vermilion sandstone (14) .................................................... , ........... _ _ 650 

Red and gray, often massive sandstone with some shale beds (15-20) .......................... _ 950 

Red and gray sandstone with shaly partings, carrying carbonized fragments of wood (21-22).... 235 

Thin-bedded and massive sandstone with shale layers, fish teeth and other fossils (23-25)...... 100 

Reddish-brown and greenish friable sandstone and shal(J (26-29).. .... ....................... ... 860 

Gray conglomerate and sandstone (30)...................................................... 50 

[4, 390] 

The numbers in parentheses refer to \Valcott's detailed section as given by 

Cross and serve to distinguish the beds on which Cross 193k comments as follows: 

In this Kanab section it is evident that Nos. 1 to 12 inclusive, aggregating 960 feet in 

thickness, represent the upper Jurassic group called the Flaming Gorge by Powell. No. 13 is 

the White Cliff sandstone, considered as the lower Jurassic in this discussion but placed by 

Powell in the Trias. Mr. Walcott comments in his notes upon the absence of a sharp line 

between this sandstone and that below it. Reasons why an apparent transition at this horizon 

is natural have been presented. This thickness of the vermilion-colored sandstone, 14 of the 

section, was found to vary from 600 to 700 feet on opposite sides of the valley where the section 

was made, a variation which may possibly be due to erosion. 
TRIASSIC. . 515 

It is noteworthv that the White Cliff sandstone is thinner in Kanab Valley than it is to 

the east, where Dutton and Powell refer to it as 1,000 feet thick. Beneath the White Cliff 

sandstone occur 2,845 feet of beds, which are referable to the Trias. It is not certain just 

what represents the Vermilion Cliff sandstone of Dutton, said by him to be 2,000 feet thick 

near the Vergen River and 1,400 or 1,500 feet thick in the zone crossed by the Kanab. It 

would appear, however, that beds 14 to 20, inclusiVE\ in all1,600 feet of sandstones, represent 

the Vermilion Cliff of Dutton, although the distinctive color is not present throughout. Assigning the beds specified to the Vermilion Cliff, the remainder of the section, embracing 1,245 

feet of bed.s, must be referred to the Shinarump group of Powell. 

. The Shinarump of Kanab Valley, thus delimited, carries fossil wood in the basal conglomerate and at various horizons in the upper portion. Far more interesting than the silicified 

wood, which has not been studied by paleobotanists, are the fish and other animal remains 

obtained by Walcott in beds 23-25 of the section-that is, in the upper third of the Shinarump. 

These fossils were sent to the National Museum, and in the confusion of adequate storage 

facilities were lost sight of until a few months ago. On being found they were sent to Dr. 

C. R.. Eastman for identification and description. Dr. Eastman's complete identifications are 

not yet available, but he has published a brief preliminary reference to the ichthyic fauna, 

from which the following is abstracted: 

"These remains * * * are extremely fragmentary and do not permit of accurate 

specific determination. Of the few genera which are tolerably well indicated, such as Pholidophorus and several Lepidotus-like forms, it can not be said that they evince anything in 

common with the Triassic fauna of the Eastern States. Some resemblance is to be noted 

between the Kanab fish fauna and that of Perledo near Lake Como, but the general aspect 

of the material collected by Dr. Walcott is suggestive of Jurassic rather than of Triassic relations. This might very well happen, notwithstanding the horizon be definitely proved by 

stratigraphic and other evidence to be of Triassic age, as other instances of pioneer faunas 

and overlapping contingents are not uncommon. 

Associated with the fish remains there were found several representatives of other classes 

of animal life, concerning which Dr. Eastman has given me the following comments, pending 

more careful investigation: "There is one ammonite in the collection, or rather the portion 

of the outer volution of one, which is very suggestive of the Liassic Arietidre, and in the opinion 

of Dr. Jackson and Mr. Shimer who have examined it, does not seem to belong to the class 

of forms known from the Pacific Coast Trias." There are numerous Estheria in the collection 

and fragmentary saurian teeth, but whether of crocodilian or ichthyosaurian forms Dr. 

Eastman is unable to determine. 

From the statements of Eastman it appears that the Kanab fauna obtained by Walcott 

is unique and raises several interesting problems for solution. The fossil-bearing strata were 

traced by Walcott from the Kanab eastward to the Colorado River and thus are known to 

occur not far from the area in which the saurian fauna of the Little Colorado was obtained by 

Ward and Brown, both faunas belonging apparently to the Shinarump group. The relations 

of the two fossiliferous horizons are as yet quite unknown. From the stratigraphic standpoint 

it is difficult to see how the Kanab fossils can possibly be of Jurassic age, unless there are 

complications, hitherto wholly unsuspected, in the great section of the plateau country. 

In the preceding comments on Walcott's Kanab section of the Jurassic 

and Triassic, Cross regards the ·white Cliff sandstone as Jurassic. It had been 

considered Tria'3'3ic by Powell, and also by King, Emmons, and C. A. White, in 

northeastern Utah and northwestern Colorado. Cross 1931 refers to certain 

"Permo-Carboniferous" fossils collected by Howell from the Shinarump, which 

were erroneously identified as Jurassic. Weeks 873b sums up his own observations, 

as well as those of previous obgervers in the Uinta Range, as follows: 

The Trias was defined by Emmons as consisting of red sandstones with a series of clayey 

beds at the base, having an estimated thickness of 2,500 feet. Powell did not separate the 
516 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Jura from the Trias. He divided the Jura-Trias beds into the Shinarump, Vermilion Cliff, 

White Cliff, and Flaming Gorge groups, having a total thickness of 3,845 feet. The Trias of 

the Fortieth Parallel Survey appears to correspond to the Shinarump, Vermilion Cliff, and 

White Cliff groups of Powell. The writer has classed the shales at the base of the Trias with 

the Permo-Carboniferous. The line of division between the Trias and the Permian is placed 

at the base of the massive cross-bedded sandstones. 

In the Uinta uplift the Trias, Jura, and Cretaceous strata are largely covered by Tertiary 

sediments or glacial debris. The principal areas of the outcrop are in the Flaming Gorge 

Canyon of the Green River in the vicinity of Split Mountain and Ashley and Dry Forks creeks, 

and on the Duchesne River several miles below the mouth of West Fork, on the south side of 

tho range. The Trias is much thicker in the eastern part of the range. In the western part 

the clayey beds of the upper part of the Trias were apparently not deposited. The coarse 

cross-bedded sandstone, 300 to 400 feet thick, is a dark-buff color in the Duchesne region, 

which varies to lighter color to the eastward. 

The Jura is composed of sandstones, shales, and clay beds, with a prominent limestone 

series having a maximum thickness of 200 to 300 feet, the whole averaging from 600 to 800 

feet in thickness, as determined by the Fortieth Parallel Survey. The Flaming Gorge group 

of Powell is considered to represent the Jura. The writer considers the prominent drab limestones to form the base of the series, the remainder of the Jura being formed of the overlying 

sandstones, shales, and clays. 

The areas of outcrop of the Jura in the Uinta uplift correspond to those of the Trias and 

appear to have a greater thickness of beds in the eastern part of the rang~. In the Duchesne 

Valley the Jura is represented by a compact drab and gray limestone and soft red calcareous 

shales. The transition from the buff or brown cross-bedded sandstone of the Trias to the 

Jurassic oolitic and granular limestone is made in less than 10 feet of strata. 

In northern Colorado Triassic rocks have been identified by fossils found on 

Red Dirt Creek, a tributary of Grand River near the headwaters, northwest of 

Leadville and south of the fortieth parallel. 447 Still farther north, in central Wyoming, Tria-;sic fo-;sils have been collected near Landerfrom strata called by Williston 941 

the Popo Agie beds and described as being from "40 to 80 feet in thickness" and 

occurring in the red bed3, about 200 feet below their t::>p and 600 feet above their 

base. The type locality is Popo Agie River, near the east end of the Wind River 

Range, and thus not far from the Owl Creek and Bighorn ranges, in which Darton 

has distinguished the supposed Triassic under the name Chugwater formation. 

(See K 12-13, pp. 530, 531.) 

Regarding the possible absence of Triassic on the eastern side of the Front 

Range in Colorado, where the red beds are believed to be largely if not wholly 

Permian, Cross's views have been quoted. (See Chapter XI, pp. 490-492). ·williston 942 refers to the discovery by Marsh 571 of Hallopus in Garden P':Lrk, near Canon 

City, and regard-; the fo~sil as significant of the Upper Triassic, although the exact 

horizon can not be identified. 

Fenneman 328 describes the Fountain, Lyons, and Lykins formations of the 

Boulder district, Colorado (north of the Can:m City district), as possibly Triassic. 

The Fountain, however, is of Pottsville age-that is, lower Pennsylvanian. (See 

Chapter VIII, pp. 369-370.) The Lyons 11nd Lykins are either Triassic or Permian. 

Fenneman says: 

The rocks in this region, hitherto regarded as of Triassic age and called "Wyoming," 

embrace three formations-the Fountain, the Lyons, and the Lykins. The term "Red Beds" 

is popularly used without definite limitations, but the authors of the monograph on the Denver 
TRIASSIC. 517 

Basin have conveniently limited the use of this term to the lowest and largest member of the 

series. The popular use of the term "red rock" is similarly restricted. 

The subdivision into "Lower" and "Upper" Wyoming, adopted for the Denver Basin, 

would also be appropriate to the Boulder area. The lower division, however, clearly embraces 

two lithological units which it is desired to distinguish in this report. The lower and major 

part consists chiefly of rather coarse arkose sandstones and conglomerates of reddish color, 

while the upper and lesser part is a finer-grained quartzose sandstone of white, "creamy," 

or light-reddish color. The coarse red sandstones were called the Fountain formation by 

Cross in the Pikes Peak folio, a type section being crossed by Fountain Creek, near Manitou. 

The summit of the Fountain formation is not exposed in the Pikes Peak quadrangle, but Darton a 

has found the character of the Fountain, as described by Cross, to continue to a white sandstone corresponding with the "Creamy sandstone" of Eldridge, occurring in the Garden of 

the Gods, to which the name Lyons sandstone is here given. 

No Triassic beds are known on the eastern slope from Canon City, Colo., south 

to northern New Mexico, but in that region, northwest of Santa Fe, first Newberry 

and later Cope found Triassic fossils in red beds. Cross 193n comments as follows: 

While Marcou and other early explorers of New Mexico announced the presence there of 

Triassic formations, the first fossils indicating the correctness of this assertion were obtained 

by Newberry in 1859. The fossils described by Newberry himself were fossil plants obtained 

from the old copper mines near Abiquiu, a locality on Chama River some 20 miles or less above 

its junction with the Rio Grande. The plants are mainly cycads and conifers, and as they have 

not been identified at many other localities they are of less importance to the present discussion 

than the vertebrate remains described by Cope, to which reference will soon be made. 

The formation from which the Abiquiu plants were obtained is described by Newberry as 

consisting mainly of red sandstones, with conglomerates and many variegated beds of soft 

shales, with abundant saline efflorescences, which led him to characterize the red beds of New 

Mexico and Arizona in general as the "Saliferous series." Fossil wood, often in tree trunks, is 

mentioned. 

Although I can not find that Newberry mentioned vertebrate fossils in the Triassic beds of 

the Chama Valley, it appears that he found some, for Cope, who followed him in the exploration 

of the region, states that the first invertebrates from the Trias of the Rocky Mountains were 

collected by Newberry with the Macomb expedition. Cope visited Chama Valley and the 

Gallinas Mountains, lying west of it, in 1864, while on the Wheeler Survey, and obtained various 

vertebrate fossils from the Triassic beds. 

The fragmentary remains described by Cope embrace teeth and bones of three dinosaurs, 

two of which were generically determined as La>laps and Pala>octonus. Similar portions of a 

belodont crocodile were called Typothorax coccinarium. Associated with these were found five 

species of Unio. 

This assemblage of forms suggests the fauna of the Dolores "saurian conglomerate." The 

locality is less than 100 miles southeast from the easternmost known exposures of the Dolores 

formation, the intervening country being occupied by Cretaceous formations. It is therefore 

very natural to suppose that the vertebrate and plant bearing Trias of Chama Valley may be the 

direct equivalent of the lower Dolores formation. Apparently the fossiliferous strata of New 

Mexico are not overlain by a massive red sandstone equivalent to the Wingate sandstone of 

Dutton. The "Variegated marls" of Newberry, which seem clearly to belong to the McElmo 

or Morrison beds, intervene between the "Saliferous series" and the Cretaceous. 

In regard to the Triassic portion of the Shinarump group of Powell in southern 

Utah and northern Arizona, Cross 191 published the following statement: 

The Shinarump is the lowest of three formations or groups assigned by Powell to the Trias, 

the others being the intermediate Vermilion Cliff sandstone and the White Cliff sandstone at ------------------------ --------------- --- a Bull. Geol. Soc. America, vol, l5, 1904, p. 22. 
518 INDEX TO THE S'rRATIGRAPHY OF NORTH AMERICA. 

the top. The Triassic was thus supposed by him to embrace everything present in the great 

section north of the Grand Canyon between the upper Aubrey (Pennsylvanian) and the marine 

Jurassic. 

Dutton and other writers have referred the White Cliff sandstone to the Jurassic, and this 

reference is no doubt correct, since the continuity has been established between this very well 

marked formation and the La Plata sandstone of Colorado, which is in angular unconformity 

with the Triassic and the entire Paleozoic sertion. a The Triassic age of the Vermilion Cliff 

sandstone has not been directly questioned, neither has it been fully proved, and it will appear 

in the course of this discussion that there is some slight basis for the suggestion that it is lower 

Jurassic. 

As for the Shinarump group, Walcott long ago found Permian fossils b in the lower beds 

referred to it by Powell and possibly Jurassic fossils a in the upper part, while a Triassic vertebrate fauna occurs near the middle of what Ward refers to the Shinarump. c The question as 

to the real character, scope, and correlation of this group is, then, plainly one requiring further 

study and consideration. 

It has been established that the Dolores formation of theSan Juan region of Colorado is of 

Triassic and probably of upper Triassic age. An angular unconformity has been found below 

the Dolores by which the whole upper Paleozoic red-bed series and a part of the Pennsylvanian 

strata are locally cut out. No middle or lower Triassic beds have been found and none demonstrably Permian. The stratigraphic break below the Dolores is thus shown to be of much 

importance. 

The Dolores formation has been traced from the mountains into the heart of the plateau 

district along two lines of approach. The most important fact established is that the fossiliferous basal member of the formation extends west and northwest from the San Juan Mountains 

as far at least as Grand River, in Utah, where the angular unconformity below it is very marked; 

and 1,500 to 2,000 feet of probable Paleozoic beds are gone at some places. An overlap of the 

basal Dolores conglomerate from Permian ( ~) beds directly to the pre-Cambrian complex occurs 

on the western side of the Uncompahgre Plateau, in Colorado, where it was observed by Peale 

in 1875. The fossiliferous lower strata of the Dolores have also been traced down the San Juan 

Valley nearly to the Glen Canyon of the Colorado, below the Henry Mountains. 

While nothing similar to the Dolores fossiliferous conglomerate has been described from 

the original area of the Shinarump group in Utah or Arizona, the discovery by Warde on the 

Little Colorado River of the vertebrate fauna characteristic of the Dolores shows plainly that a 

correlation of great importance is to be anticipated when the requisite studies have been made. 

J 17-18. RICHMOND BASIN, VIRGINIA. 

The stratigraphy of the Richmond Basin was first worked out m detail by 

Shaler and Woodworth. 731 They say: 

A casual observer traversing the Richmond area on any one of the section lines described 

in this report can not but note that there are several leading lithological features displayed in 

bands by which the strata may be thoroughly grouped. When one seeks to trace out these 

bands along the strike of the strata the futility of the task is at once apparent. It is only on the 

broadest possible lines with a considerable error in the placing of boundaries between distinguishable groups of strata that a mapping of the basin can at present be carried out. 

The accompanying table of divisions is an expression of the present knowledge concerning 

the lithological and biologic characters of the area. 

a Cross, Whitman, and Howe, Ernest, Red Beds of southwestern Colorado and their correlation: Bull. Geol. Soc. 

America, vol. 16, 1905, pp. 447-498. 

b Walcott, C. D., The Pe1'!llian and other Paleozoic groups of the Kanab Valley, Arizona: Am. Jour. Sci., 3d ser., 

vol. 20, 1880, pp. 221-225. 

cward, L. F., Geology of the Little Colo;ado Valley: Am. Jour. Sci., 4th ser., Yol. 12, 1901, pp. 401-413. 
Divisions. i 

LithologicSubdivisions. 

TRIASSIC. 519 

Formations in the Richmond area. 

---------.-------------------

Biologic divisions. General characters. 

o., -~ Otterdale sandstones________ _ Araucr.rioxylon beds __ . Coarse sandstones, often feldspathic, with silicg ified trunks of Araucarioxylon; well developed 

@; north, south, and west of Otterdale. Thick- "0 ness, 500 feet. 

aJ Yinita beds ______ ._ . _ _ _ _ _ _ _ _ _ Estheria beds .... _ .. __ .

1 

Black fissile shales, carrying Estheria ovata, pass-

'E ing upward and intercalated with gray sand- tl stones; in James River bluff, west of Vinita 

1! I station, on Tomahawk Creek. Thickness, 

_o ________________ ~--:------------l--2-,_oo_o_f~e-t. __ _ 

Producti1·e coal measures .... Macrotceniopteris beds._ 

[ Lower barren beds _______ . ____ ...... _ . _ . ___ . _________ _ 

) 

Interstratified beds of bituminous coal (usually 

three seams), coke, black shales (a, fish bearing; 

b, Estheria shales; c, vegetal shales), sandstones 

(feldspathic and micaceous), fossil plants; 

teeth', bones, and tracks of reptiles. Thick- ness 500 (?) feet. 

Sandstones and shales under coal beds, often 

with arkose. Thickness variable, from 0 to 300 

feet. 

Local deposits; bowlders of gneiss and granite. 

Thickness variable, 0 to 50 feet. 

I Boscabel bowlder beds ____ --l·. -. ------------------- ----~----------------------

The divisions ara described in much detail and with reference to exact localities in the pages following this tabulation in the report cited. 

J-K 10. NORTHERN CALIFORNIA. 

The Triassic of Shasta County, Cal., from which fossils were first described 

by Gabb, 349 has been studied by Smith, who distinguished the Pitt shale (now 

spelled Pit), Swearinger slate, and Hosselkus limestone. (See table, p. 374, Chapter VIII.) The Pit shale is the upper part of the so-called "Pitt formation," 

concerning which Smith 762a writes: 

The Pitt formation overlies conformably the McCloud limestone and consists, roughly 

estimated, of about 3,000 feet of siliceous and calcareous shales, conglomerates, and tuffs. 

The rocks in most places are highly metamorphosed, very poor in fossils, and folded to such 

a degree that the stratigraphy is obscure. The general strike is north and south and the dip 

generally toward the east, since most of the folds are overthrown. 

The formation is largely developed in the region near the junction of the Pitt and the 

McCloud rivers. It contains both Carboniferous and Triassic rocks, in an apparently conformable series, both with a decisive fauna, the presence of Upper Carboniferous and .Middle 

Trias being proved by fossils. 

The lower part of the " Pitt formation" consisted of the "McCloud shales" 

(Carboniferous). This name has now been abandoned by the Survey, the shales 

being included in the Nosoni formation of Diller 279 (Pennsylvanian). The name 

McCloud is, however, retained for the underlying limestone (also of Pennsylvanian 

age). 

Details of faunas and local occurrences of the two divisions of the "Pitt formation" are given by Smith in the paper cited above, followed by an account of the 
520 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

"Cedar formation," comprising the Swearinger slate and Hosselkus limestone. 

Smith 762b says: 

The Cedar formation was first named by J. S. Diller a to include the Upper Triassic slates 

and limestones of Indian Valley, Plumas County, and Cedar Creek, Shasta County. It therefore includes the original Trias described by Gabb b from "Gifford's ranch." 

In the Pitt River region the formation is very similar to that in Plumas County, being 

composed of finely laminated shales overlain by massive limestone, each rich in fossils. It 

seems to overlie conformably the siliceous shales of the Pitt formation, but the contact could 

not be observed. 

The Triassic of Plumas County, Cal., has been discussed by Diller 271 and 

Hyatt.467 In a recent publication on the geology of the Taylorsville region Diller 280 

gives the following section: 

Triassic: 

Unconformity. Feet. 

Swearinger slate: Dark slaty calcareous shales, with thin limestones and some siliceous beds. 200 

Hosselkus limestone: Dark-blue to light-gray limestone .... __ .... _._._ ...... _ ... _._._ .. _ .. 140 

Unconformity. 

The Hosselkus limestone is dark blue on fresh fracture but weathers light gray. * * * 

It is thin bedded and in some places decidedly slaty * * * and characterized by small 

ammonites. * * * In the Redding region * * * the upper part is lighter colored and 

more massive, with a Spirifer-like shell, and the lower part thinner bedded and darker, with 

small coiled forms. 

The fossils collected from this limestone by Prof. Hyatt and others in the Taylorsville 

region have not yet been fully worked up. A partial list is given by Hyatt: c 

I. Arcestes, phylum of A. tomati. 

Arcestes, phylum of A. galeati. 

Arcestes, phylum of A. bicarinati. 

Arcestes, phylum of A. sublabiati. 

Badiolites, allied to B. eryx Mojsisovics. 

Juvavites, allied to J. erlichi Moj~isovics. 

'J'ropites, may be young of species occurring in Halobia slates. 

Atractites. 

"Arcestes (I) is very abundant, but whether the other forms are abundant or not it is 

difficult to say at present. The materials gathered show that the rock is full of fossils, but 

these can not be obtained in any reasonable time by means of surface work. Besides the 

species mentioned, there is a form of Acrochordiceras, with finer costre than those occurring 

in the Muschelkalk, a possible Balatonites, like B. waageni of the N oric, and some other fragments of Ceratitinre, all indicating a fauna rich in ammonoids, which will some day yield a 

good harvest to patient work.'' 

Prof. Hyatt concludes that the age of the Hosselkus limestone as indicated by the fossils 

is upper Triassic. To this list Spiriferina and fish vertebra, as deternlined by Stanton, were 

added last summer. This limestone has not yet been thoroughly examined for reptilian remains, 

such as J. C. Merriam has found in the Redding quadrangle, but as the limestone of the Taylorsville region is more altered and much less fossiliferous, reptilian remains are less likely to occur. 

In the Redding region the more massive upper portion of the Hosselkus limestone is characterized by the presence of Spiriferina, while the lower, darker, thin-bedded portion often 

abounds in small ammonites. * * * 

The reference of the Hosselkus limestone to the upper Triassic and the Robinson formation 

to the upper Carboniferous indicates a decided gap between them, a gap which is at least 

partially filled in the more complete section of the Redding region, where a great thickness 

a Lassen Peak folio (No. 15), Geol. Atlas U.S., U. S. Geol. Survey, 1895. 

b Paleontology of California, vol. 1. 

c Bull. ¥eol. Soc. America, vol. 3, 1892, pp. 399-400. 
TRIASSIC. 521 

(over 1,000 feet) of andesitic and rhyolitic lavas, with 1,500 feet of overlying shales, sandstones, and tuffs of Triassic age, comes between the horizon of the Robinson formation and 

that of the Hosselkus limestone. It is evident, therefore, that in the Taylorsville region there 

is a decided interruption between the Hosselkus limestone and the Robinson formation. It 

is possible, however, that their contact in the Taylorsville region is a plaiw of displacement, 

and that the formations of the Redding region missing in the Taylorsville region may, in part 

at least, be thus accounted for. 

* * * * * * * * * 

The Swearinger formation is composed chiefly of dark slaty shale, sometimes becoming 

more or less calcareous and at others decidedly siliceous, but the thin beds of limestone or 

chert form only a small proportion of the whole mass. In the side of the Swearinger slate 

adjoining the Hosselkus limestone thin lenticular beds of limestone become more abundant. 

They are generally dark, with irregular cherty or sandy layers, and fossiliferous. 

* * * * * * * * * 

The greatest thickness of the Swearinger slate exposed along Genesee Valley, where measured, is about 200 feet, but the amount cut off by the granodiorite or covered by the overlapping Trail formation we have no means of estimating except by comparison with formations of the same horizon in other regions; such comparison indicates that the thickness is 

probably not over 400 feet. 

The fossils of the Swearinger slate were discovered and described by the Geological Survey 

of California under Prof. J. D. Whitney. Our knowledge of the fauna was greatly extended 

by Prof. Alpheus Hyatt, who has published a lists of the forms found in the subordinate paleontological horizons within the formation. They need not be repeated here except to note 

that the form from these beds once regarded as Monotis subcircularis is now considered by 

J. P. Smith and others to be Pseudomonotis. Prof. Hyatt regarded the Swearinger slate as 

belonging to the upper Triassic, equivalent to the upper N oric of the Alpine Triassic, and as 

far as I am aware this reference has not been changed essentially by the somewhat later 

researches of Prof. Smith. 

J-K 10-11. NEVADA AND EASTERN CALIFORNIA. 

The Triassic section of Nevada was originally described by King _soae in the 

following summary of the data stated more at length on other pages of his report. 

Passing now to the district of western Nevada, the sections, which often do not reach 

the base of the conformable series, expose two distinct, easily recognizable groups of the Trias. 

The Koipato, already described, is made up of siliceous and argillaceous beds, whose chemical 

peculiarity is the almost total absence of soda and lime and the high percentage of alumina 

and potash-a series probably derived from the disintegration of the heavy Weber Carboniferous quartzite, which must for a long time have constituted the main surface of the erosion 

of the newly lifted Mesozoic land. This series has an observable thickness of about 6,000 feet, 

with an unknown quantity to be added for the bottom unseen beds. Conformably over the 

Koipato is the great Alpine Trias Star Peak series of 10,000 feet, composed of an alternation 

of three great limestone zones and three interposed quartzite zones, the lower quartzite closely 

following the physical and chemical peculiarities of the Koipato series below, the upper two 

quartzites representing moderately pure .siliceous sediment. The fossils of these limestones, 

as already described, repeat with marvelous exactness the facies of the St. Cassian and Hallstadt beds of the Austrian Alps. 

Smith 764a states that beneath the strata of Middle Triassic age in Inyo County, 

southeastern California, occur Lower Triassic beds. He says: 

In 1896 Dr. C. D. Walcott discovered some ammonite-bearing limestone in Inyo County, 

Cal., on the east side of Owens Valley, 10 miles east-northeast of Lone Pine, 3 miles southeast of ·------ ··-------------- a Bull. Geol. Soc. America, vol. 3, 1892, pp. 397-400. 
' 

522 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

the Reward ::\fill, and about 1,500 feet up above the mill, on the Union ~Wash trail from Independence over the Inyo Range into Saline \'alley. The fossils were submitted by Dr. Walcott 

to the writer for identification, and referred to the Lower Trias, on the basis of the occurrence of 

several genera characteristic of the Brahmanic stage of the Scythic series in the Oriental region. 

In a preliminary report the writer did not venture to describe new species or genera, but noted 

the occurrence of Nannites, Clypites ?, Koninckites, Meekoceras, Kingites, Gyronites ?, Xenaspis, 

Dinarites, and a new genus of Tropitid~e. Later collections and better material have confirmed 

most of these identifications, but the form referred to Clypites has proved to be a new genus of 

the same group; the supposed Kingites is very uncertain; the Dinarites has turned out to be a 

Paralecanites; and the supposed new genus of the Tropitidrn belongs to the Hungaritidre. 

Later collections, by Mr. H. W. Turner, of the United States Geological Survey, and by the 

writer, have added greatly to the list of genera and species, bringing out even more strongly the 

relations of this fauna to the Brahmanic faunas of the Asiatic regions. 

At the base of the section seen on the U!-lion vVash are massive siliceous and calcareous 

beds supposed, on the basis of fossils found in the float, to belong to the Carboniferous; then 

several hundred feet of calcareous shales with obscure traces of ammonites; then about 15 feet 

of hard gray siliceous limestone, from which all the fossils listed from this horizon were taken. 

Above this limestone lie about 800 feet of dark shales with a few impressions of ammonites; 

then about 5 feet of impure earthy black limestone with numerous ammonites, Ptychites, Hungarites, Acrochordiceras, Xenodiscus, thought by the writer to belong to the base of the Nfiddle 

Trias, or the Subrobustus beds of the Oriental region. 

Lindgren 538 describes the Sailor Canyon formation and associated slates, 

quartzites, and schist in the Colfax quadrangle, California, west of Lake Tahoe, 

as "Juratrias," having found ammonites and other shells in the beds. 

J-K 18. NEW JERSEY, PENNSYLVANIA, AND MARYLAND. 

The Newark group is typically developed in New Jersey, and the rocks occur 

in several distinct belts from Massachusetts to North Carolina. 683 

The Triassic sediments of New Jersey and New York were described without 

definite subdivision prior to the work by Ki.immel/11 from which the following 

extracts relating to the separate formations (Stockton, Lockatong, and Brunswick) 

and the associated igneous rocks are taken. 

The Newark series consists of sedimentary and igneous rocks. The former are chiefly 

shales, sandstones, and conglomerates; the latter diabase, to which the more general term trap 

has usually been applied. Along the Delaware River the sedimentary rocks are divisible, on 

lithological grounds, into three groups, which have been called Stockton, Lockatong, and 

Brunswick. 

Stockton group.-The basal beds of the series are found at Trenton, where they rest unconformably upon the older crystalline rocks. They consist of (a) coarse, more or less disintegrated 

arkose conglomerates; (b) yellow, micaceous, feldspathic sandstone; (c) brown-red sandstones 

or freestones; and (d) soft red argillaceous shales. These are interbedded and many times 

repeated, a fact which indicates rapidly changing and recurrent conditions of sedimentation. 

Although there are many layers of red shale in this subdivision the characteristic beds are the 

arkose conglomerates and sandstones, the latter of which afford valuable building stones. 

In addition to the cross-bedded structure which often prevails in the sandstones, mud 

cracks and impressions of raindrops occur. The rapid alternation from conglomerates to shales 

and vice versa, the changes in composition in individual beds, the cross-bedding, ripple marks, 

etc., all indicate very clearly that these beds were deposited in shallow water in close proximity 

to the shore. The bulk of the material of which they are composed was derived from the crystalline rocks on the south and southwest, but where they were found to rest upon Silurian shales, 
TRIASSIC. 523 

limestones, and quartzites, as was the case along the northwestern border north of Flemington, 

material from these formations has determined their local character. * * * 

The rocks of the Lockatong group overlie the Stockton beds conformably. They consist of 

(a) carbonaceous shales, which split readily along the bedding planes into thin lamitue but 

have no true slaty cleavage; (b) hard massive black and bluish-purple argillites; (c) dark-gray 

and green flagstones; (d) dark-red shales approaching a flagstone; (e) and occasional thin layers 

of highly calcareous shales. There are all gradations between these somewhat distinct types, 

so that the varieties of individual beds are almost countless. Both ripple marks and mud 

cracks occur at all horizons, showing that shallow-water conditions prevailed throughout the 

time of their deposition. On the other hand, the absence of strong currents or violent shore 

action is indicated by the extreme fineness of the material. 

* * * * * * * * * 

In general the Brunswick group consists of a monotonous succession of very soft argillaceous 

red shales which crumble readily to minute fragments or split into thin flakes. Much of it is 

porous, the minute, irregular-shaped cavities being often partially filled with a calcareous 

powder. Calcite veins and crystals are common in some layers. Locally lenticular masses 

of green shale occur in the red. In size these range up to a foot or two in diameter, and vary 

in shape from nearly spherical to lenticular masses, narrowing down to thin sheets along cracks. 

They are undoubtedly due to chemical changes resulting in the leaching of the shale. 

Although the majority of this series are soft red shales, there are some hard layers, chiefly· 

near the base, and occasional beds of fine-grained sandstone and flagstones, some of which 

afford valuable building material. Massive conglomerates along the northwestern border are 

in part the shoreward correlatives of the red shales. 

Evidence that the shales were deposited in shallow water is abundant. Ripple marks, 

mud cracks, and raindrop impression:? occur at many horizons. In some quarries imprints of 

leaves, of tree stems, or the stems themselves are frequently found. The numerous reptile 

tracks which have made the Newark beds famous occur chiefly in this subdivision. Typical 

exposures occur along the Raritan River, particularly near New Brunswick. 

* * * * * * * * * 

Important lithological changes occur in all these beds as they are traced along their strike. 

As the northwestern border of the formation is approached, near Pittstown, the subdivisions 

lose their di:->tinctive characteristics and merge along the strike into coarse sandstones and 

massive conglomerates. This change is most striking in the case of the Brunswick and the 

Lockatong groups, where red shales or black argillites change to sandstones and then into conglomerates, the pebbles of which are frequently 6 or 8 inches in diameter. Under these conditions it is impossible to differentiate and limit these groups in this part of the field. 

* * * * * * * * * Important changes are found to occur as the beds are traced along the strike northeastward 

into New York. The Stockton beds disappear beneath the later deposits a few miles east of 

Princeton. 

* * * * * * * * * The Stockton beds certainly persist into New York, but the typical coarse arkose sandstone beds apparently thin out, and north of Nyack the group can not be identified with any 

degree of certainty. The trend of the strata apparently carries the beds of this subdivision 

beneath the Hudson River. 

Northeast of Princeton the outcrop of the typical Lockatong group grows narrower and 

the thickness is less. Either the rate of deposition was slower to the northeast during the time 

represented by the Lockatong beds elsewhere, and therefore they are thinner here, or else, the 

rate of deposition being the same as elsewhere, the conditions favoring the deposition of black 

argillite and shale did not last so long to the northeast of Princeton as nearer the Delaware. A 

few miles northeast of Princeton the Lockatong beds also are covered by the Cretaceous deposits, 

but they have been traced by borings as far as the Raritan River. They do not, however, appear 

in the region west of the Palisades and north of Newark. 

* * * * * * * * * 
524 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The Brunswick beds likewise change in texture toward the northeast. They are predominantly soft argillaceous shales from the Delaware River as far as Elizabeth. In some 

layers an increase in coarseness is noticeable, which continues northeastward along the strike, 

until in the vicinity of Newark and Orange the beds are chiefly sandstones. Many of those 

beds resemble the brownstones of the Stockton series-so closely, in fact, that hand specimens 

can be distinguished with difficulty, if at all, from much of the sandstone at Trenton and 

Stockton. 

* * * * * * * * * Still farther north layers of conglomerate appear interstratified with the sandstones and 

shales. In addition to well-marked beds of conglomerate, many layers of the sandstone contain pebbles scattered through them. The pebbles are chiefly of quartzite or sandstone, quartz, 

slate, limestone, feldspar, and rarely of flint. Not a single gneissic or granitic pebble was 

found, although a careful search was made for them. The coarse sandstone and conglomerates, 

with some shale beds, continue through Bergen County, N.J., and Rockland County, N.Y. 

Beds of coarse conglomerate occur at a number of points along the northwestern border. 

Some of these are composed chiefly of quartzite, others of limestone, and in one case of gneissic 

and granitic material. The quartzite conglomerate contains a few pebbles of limestone, shale, 

and gneiss, but almost the entire mass of the rock is made up of quartzite or sandstone pebbles, 

which are well rounded and frequently 6 or 8 inches in diameter. They are best exposed in the 

''pebble bluffs" along the Delaware River about 5 miles above Frenchtown. The conglomerates 

are interstratified with sandstones and shales, forming lenticular beds, which thin out within a 

few rods to be replaced by beds of a different texture. This alternation and rapid change 

betoken shore conditions. 

* * * * * * * * * 

The calcareous conglomerate is in appearance almost the exact counterpart of the famous 

"Potomac marble" quarried at Point of Rocks, Md. The limestone pebbles are usually bluish 

or gray, sometimes reddish, set in a red mud matrix, so that the rock has a variegated appearance. The average diameter of the larger constituents is 6 or 8 inches, but bowlders 5 feet in 

diameter have been seen, and at a quarry 2-!- miles northeast of Suffern, N.Y., bowlders 12 feet 

in diameter are reported to occur. The larger fragments are generally rounded, but the majority of the smaller are sharp-cornered or at most subangular. Compared with the pebbles in 

the quartzite conglomerate, the limestone pebbles are but little worn, a fact of some significance 

in connection with the origin and sources of the materials, since with equal transportation the 

softer limestones must have been most worn. 

* * * * * * * * * 

The relations of these conglomerates to the older rocks along the border are significant of 

faulting. In some cases the calcareous conglomerates adjoin small areas of Paleozoic limestone, 

from which the materials may have been and probably were derived. In other cases, and 

this is true of the largest areas, the calcareous conglomerates abut against the gneissic rocks, 

and for much of the distance it is certain that no limestone occurs between the gneiss and conglomerate, at least not at the surface horizon. Crystalline pebbles, however, are comparatively rare in the conglomerate. Substantially the same conditions prevail in the case of the 

quartzite conglomerate. For the most part it adjoins the gneiss, but gneissic pebbles in it are 

rare. The known areas of quartzite along the border are small, and in general not near the 

massive conglomerate beds. Lithologically, moreover, they are unlike the bulk of the quartzite 

pebbles. 

It is evident that along the greater part of this border the beds of the Newark series were 

not derived from the older rocks which now immediately adjoin them. Shore currents doubtless transported more or less material somewhat widely, and yet they do not afford us the complete explanation for these facts. The northwestern border is for the most part marked by 

faults. Here the dissimilarity of constitution is the most marked. Where the border is not 

faulted and the newer rocks rest undisturbed upon the eroded edges of th6 older beds, they are 
TRIASSIC. 525 

composed of fragments derived from them plus a small contribution by shore currents. Allowance can be made for the work of the currents, but the widespread dissimilarity of constitution 

is due chiefly to the faulting which has occurred. The waves of the sea in which the Newark 

beds were deposited did not on the northwest border in general beat against the rocks which now 

adjoin this area. 

The relation of the conglomerates to the shales is also significant. They do not form a single 

horizon which may be used in interpreting the structure. Instead, they grade either into 

argillaceous shales, or black argillites, or arkose sandstones. Time and again the pebbly layers 

were seen to appear in the shales and to increase in thickness and numbers until they become 

massive conglomerates. 

* * * * * * * * * 

The trap rocks of the Newark beds in New Jersey and New York have been described more 

or less in detail by several geologists, and it has been demonstrated that overflow sheets, intrusive 

sills, plugs, and dikes occur. 

* * * * * * * * * 

The most important of the overflow sheets are the three concentric ridges forming the 

Watchung Mountains. These sheets are to all appearances strictly conformable, both to the 

underlying and to the overlying shales. Nowhere is there any indication that the trap breaks 

across the sandstone or shale layers. Wherever the basal contact is exposed, and exposures 

several hundred feet in extent are known, the trap is seen to follow exactly the bedding plane of 

the shales. 

Moreover, the extensive metamorphism of the associated sedimentary beds, a marked 

feature in the case of all the intrusive sheets, is entirely absent. Locally, the shale is slightly 

altered for a few inches beneath the trap, but even this is not always the case. When this 

is compared with the intense alteration which has affected the shales beneath the Palisades, an 

intrusive sill, for a distance of over 100 feet, the difference between the sheets is emphasized. 

Upper contacts have not been observed in many cases, but the upper surface of these 

sheets is frequently vesicular, amygdaloidal, and scoriaceous. Locally, a thin layer of waterworn trap particles, intermixed with red mud occurs between the vesicular trap and the unaltered 

typical red shales, or the vesicules are filled with red mud. The overlying shales conform to the 

slightly irregular, ropy surface of the trap. In frequent exposures the rolling-flow structure, 

named by the Hawaiian Islanders pahoehoe, is visible. Now here have any tongues of lava been 

found extending from the main sheet into the neighboring shales. 

* * * * * * * * * 

The Palisades of the Hudson, the Rocky Hill sheet north of Princeton, the Sourland 

Mountain sheet near Lambertville, and the Cushetunk Mountain near White House are the 

largest and most prominent of the intrusive sheets. * * * In addition to these, which are 

demonstrably sills or sheets, there are more irregularly shaped masses northwest of Pennington, 

near Stockton, and at Point Pleasant (west of Stockton), the precise relations of which to the 

inclosing beds are not clearly revealed. They are beyond all doubt intrusive masses, but it is 

questionable whether they are strictly sheets. In the absence of positive knowledge as to their 

relations with the sedimentary beds, I prefer to speak of them simply as intrusive masses. 

The evidence of the intrusive origin of all these masses, sills and others, is as follows. 

Dikes radiate from the upper part of the sills and penetrate the overlying shales for distances 

up to 7 miles, as measured on the surface. The sills are locally unconformable to the inclosing 

strata, although in general they extend for long distances parallel to their strike. 

* * * * * * * * * The adjacent sediments have often been greatly metamorphosed. So intense has been 

this alteration that at distances, often of 100 feet, the rocks are as completely "baked" as those 

immediately adjoining the trap. Measured along the surface, traces of metamorphism are 

frequently found 1 foot from the nearest trap outcrop. The complete absence of scoriaceous 

rock, of amygdules, of the vesicular or the rolling-flow structure is negative evidence of their 
526 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

intrusive origin which must not be neglected. Moreover, masses of shale and sandstone have 

been embedded in the trap near both the under and upper surfaces, and the trap itself shows 

evidence in its texture of having cooled more slowly (and therefore presumably at greater 

depths) than the overflow sheets. 

* * * * * * * * * 

The overflow sheets are contemporaneous with the beds between which they lie-that is, 

the upper third of the Brunswick shales. 

The intrusive masses extend, for the most part, well up into the Brunswick shales and are 

therefore younger than these. Moreover, so far as the evidence goes, they antedate the disturbances which closed the deposition of the Newark beds. There are good reasons for believing 

that many, perhaps all, of the intrusive masses are younger than the extrusive sheets, although 

the evidence is not conclusive. From a priori .considerations it may be suggested that the lava 

formed intrusive sheets after the formation became so thick that it could not readily rise to 

the surface, whereas earlier in Newark time the lava was able to break through the inner beds 

and overflow. 

Kiimmel 511a gives his first careful estimate of the maximum thickness of the 

sedimentary formation of the Newark group as follows: 

Feet. 

Stockton._: __________ ._. __ .. _. __ . ______ . ____ . _________________________ ._ .. _._._._....... 4, 700 

Lockatong _______ . __________ . _ ..... _ . _ ... _ .. _ . __ . _ ... __ . _ . _____ . _ ... _ . _ .... _ .. _ . _ . _ .. _ .. _ 3, 600 

Brunswic], ____________ . _. ___ . _. __ . _. _. ____ . __ . __ . _. _. _. __ . __ . __ . _ .. __ . _. __ . _. __ . _. _. __ . _ 12, 000 

20,300 

These figures his later investigations led him to modify, his revised estimate 511 b 

being: 

Feet. 

Stockton. ___________ ._. _______ ._. ___ .. __ ._ .. -_.- __ .-.- .. -.. -.--.-.-- ..... -.... _.. 2, 300- 3, 100 

Lockatong __________________ . __ ._ ...... __ .... __ ._ .. __ .. _._ .. _ .. _._._._ .. _ .. _._ ... _ 3, 500- 3,600 

Brunswick. __________ .. _. ___ . ___ .. _ ... _. __ . _ .. _. __ .. _ .. _ .. _. __ . _ ... _. __ . __ . _. _. . . 6, 000- 8, 000 

11,800-14,700 

The Newark group passes from New Jersey into Pennsylvania in the Trenton 

quadrangle and is described in detail by Darton 59 in the Trenton folio. 

The continuation of the belt northwest of Philadelphia is discussed by Darton,58" who says: 

The Newark group in Pennsylvania occupies a broad belt extending across the southeastern 

portion of the State from Delaware River to the Maryland line south of Gettysburg. It is 32 

miles wide on the Delaware, 12 miles on the Susquehanna, 4 miles in northern Lancaster County, 

and 14 miles at the Maryland line. It is bounded by shales, limestones, sandstones, quartzites, 

mica schists, gneisses, and granites, varying in age from Ordovician to pre-Paleozoic, which it 

overlaps along irregular boundary lines. In some portions of the area its margin is determined 

by faults, but these marginal faults appear not to be extensive either in throw or in length. 

Over wide areas the dips are to the north and northwest, but in some districts there are flexures 

of moderate amount and extent. The group is traversed by numerous normal faults, mostly 

extending northeast-southwest and with downthrow on the east side of the fault plane. One 

of these extending through Bucks and Montgomery counties has a vertical displacement of 

several thousand feet. 

In the rocks of the Newark group in southeastern Pennsylvania, as in other regions, the 

typical red-brown sandstone and shale predominate, and there are igneous rocks in intrusive 

sheets and dikes. The classification which has been established in New Jersey is applicable 

here, and comprises three formations-the Stockton, Lockatong, and Brunswick, the last 

named being the youngest. A series of names proposed by the Pennsylvania Geological Survey 

has not been found acceptable because of their indefinite application. 
TRIASSIC. 527 

The Stockton formation comprises gray to bu:t arkosic sandstone, red-brown sandstone, 

and numerous masses of red shale in no regular succession and presenting many local variations 

in stratigraphy. It lies on gneiss, schist, quartzite, and limestone, in Montgomery, Bucks, 

and northern Chester counties. Many of the sandstones are cross-bedded, and the finer-grained 

rocks exhibit ripple marks, mud cracks, and raindrop impressions, which indicate shallow-water 

conditions during deposition. The lower beds usually are arkose-a sandstone containing 

more or less feldspar and kaolin derived from the gneiss. The Lockatong formation consists 

mostly of dark-colored, hard, compact, fine-grained rocks originally composed of a mixture of 

clay and fine sand in variable proportions. Some beds are moderately massive, others vary 

from shaly to flaggy, and many of them exhibit mud cracks and other evidences of shallow-water 

deposition. Some of the beds contain carbonaceous material. The Brunswick shale consists 

mainly of a great thickness of soft red shale with some thin sandstone layers. 

These three formations are not sharply separated by abrupt changes of materials but usually 

merge through beds of passage which appear to vary somewhat in thickness and possibly also 

in stratigraphic position in different areas. 

Clark 143 gives the following brief account of the Newark formation in Maryland. 

The belt passes thence into Virginia. (For a discussion of the Richmond field, 

see pp. 518-519.) 

The deposits of the Newark formation unconformably overlie the limestone and phyllite 

which have been above described and cover a considerable area along the western border of the 

Piedmont Plateau. Beginning as a belt some 10 miles in width in northern Carroll and Frederick counties, the formation gradually narrows toward the south, until in the region of Frederick 

its full width does not exceed 1 mile, while at one point directly to the west of Frederick the 

continuity of the beds is completely broken. Farther southward, in western Montgomery 

County, the belt of Newark deposits again broadens to a width of several miles. 

The rocks of the Newark formation consist largely of red and gray sandstones and conglomerates of both siliceous and calcareous varieties. The finer-grained and deeper-colored deposits 

generally have their individual elements united by a ferruginous cement, while the calcareous 

conglomerate, which is largely made up of rounded limestone pebbles, is generally embedded 

in a reddish calcareous matrix. All of the deposits present structures which indicate that they 

were formed in shallow water; the coarse conglomerates, the ripple-marked surfaces, and the 

tracks of animals all point indisputably to this conclusion. 

J-L 10-12. WESTERN UNITED STATES. 

A philosophic discussion and correlation of American Triassic stratigraphy 

has been given by J.P. Smith. 765 The marine Triassic of the western United States 

is found in Oregon, Idaho, California, and Nevada. Its distribution and relations 

are summed up by Hyatt and Smith 469 as follows: 

The marine Triassic section of [western] America is unusually complete, and its thickness 

compares favorably with that of any other region. All three subdivisions-Lower, Middle, 

and Upper Triassic-are represented by calcareous deposits, aggregating approximately 4,000 

feet in thickness. Of this amount, about 800 feet belong to the Lower Triassic, about 1,000 

feet to the Middle Triassic, and about 2,000 feet to the Upper Triassic. 

The entire section is not represented at any one locality, nor is the thickness of each division 

constant. Furthermore, the marine Triassic is not everywhere developed as a calcareous 

formation. In the United States the Triassic system is represented by marine deposits only 

in the Western States, in Idaho, Nevada, Oregon, and California. 

The Lower Triassic is known only in Idaho and southeastern California, where about 800 

feet of shales and limestones contain fossils characteristic of this series. The most important 

genera are Meekoceras, Danubites, Columbites, Flemingites, Aspidites, Lecanites, Ophiceras, 
528 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Nannites, Ussuria, Pseudosageceras, Hedenstrcemia, Cordillerites, Tirolites, and Proptychites, 

most of which are represented by closely related species in the Lower Triassic of India and 

Siberia. 

The Middle Triassic occurs chiefly in Nevada and southeastern California. In the Inyo 

Range, southeastern California, about 200 feet of shaly limestones contain the following genera 

characteristic of the lower horizon of the Middle Triassic: Acrochordiceras, Xenodiscus, Hungarites, Ptychites, Tirolites, Ceratites, and Parapopanoceras. 

In central Nevada, in the West Humboldt Range, the higher beds of the Middle Triassic 

are represented by about 800 feet of shaly limestones, in which the most characteristic genera 

are Ceratites, Anolcites, Dinarites, Danubites, Celtites, Hungarites, Beyrichites, Acrochordiceras, Balatonites, Eutomoceras, Ptychites, Joannites, Lecanites, and Atractites among the 

cephalopods, Daonella among pelecypods, and Cymbospondylus among vertebrates. 

The Upper Triassic is best represented in northern California, where the Hosselkus limestone and the shales below and above this formation contain characteristic fossils. The Hosselkus limestone and the interbedded shales have a thickness approximating 500 feet. Fossils 

are very abundant throughout this formation, although much better preserved near the base. 

The best known fauna belongs to the zone of Tropites subbullatus, and contains as its most 

important members the following genera: Tropites, Paratropites, Discotropites, Juvavites, 

Sagenites, Leconteia, Trachyceras, Clionites, Arpadites, Polycyclus, Metatirolites, Hauerites, 

Dieneria, Arcestes, Paraganides, Proclydonautilus, Cosmonautilus, and Atractites among 

cephalopods, Halobia among pelecypods, and Shastasaurus among the vertebrates. 

Above the Hosselkus limestone lie the Pseudomonotis slates, of unknown thickness, characterized by Halorites, Rhabdoceras, Arcestes, and Pseudomonotis. 

In the West Humboldt Range in Nevada the Star Peak limestone, about 1,200 feet thick, 

appears to represent the Hosselkus limestone, although very few fossils have ever been found 

in it. Above the limestones lie the Pseudomonotis beds, about 800 feet of shales and shaly 

limestones, in which are found Pseudomonotis subcircularis, Rhabdoceras, Halorites, Placites, 

and Arcestes, an association characteristic of the Noric horizon. 

K 12. SOUTHEASTERN IDAHO. 

Peale and White first described the probably Lower Triassic rocks of southeastern Idaho occurring in the Blackfoot Basin near John Grays Lake, in latitude 

43°, longitude 111° 30'. Peale 630 gives the following section: 

General section of Jura-Trias in southeastern Idaho and western Wyoming. 

Carboniferous ( ?) . 

1

5. Hed and gray shales with green sandstones and irregular greenish arenaceous limestones at the 

top. Thickness, 700 feet. . 

1

4. Laminated limestones, blue at base, passing into gray at top, succeeded above by grayish cal- careous shales; many of the layers are probably arenaceous. Thickness, 800 feet. 

--- ---· ----

3. Red quartzitic sandstones with shaly arenaceous and calcareous layers at the base of the 

section. These are probably the equivalent of the typical "red beds" of the Eastern Rocky 

Mountains. Thickness, 1,000+ feet. 

1

2. Alternations of reddish and greenish sandstones and arenaceous and calcareous shales with blue 

and gray limestones, generally lami;mted. T_hicknes~, ?,OOO+ fpet. . These with No.1 are the beds of the sectwn glVen m Dr. ·wh1te's paper (as that of locahty No.1). 

The beds are fossiliferous at four horizons, containing species of a new Triassic (?)genus named 

Meekoceras by Prof. Hyatt, together with forms that have been heretofore regarded as of 

Jurassic age. 

I l. Massive grayish-blue limestone, overlain by quartzite and dark-blue laminated limestones. 

I Thickness, 1,200+ feet. 

I 
TRIASSIC. 529 

The" Meekoceras beds" of Peale are not recognized either by him or by Schultz 

in western Wyoming, 25 miles east of John Grays Lake. Smith 764 gives the 

following description of the occurrences in Idaho: 

Many years ago Dr. A. C. Peale discovered in southeastern Idaho and southwestern Wyoming a series of fossiliferous beds lying below the red beds and above the Carboniferous limestone. The fossils found in this formation were described by Dr. C. A. White and assigned to 

the Lower Trias. Cephalopods were found at but two places-locality No. 1, in southeastern 

Idaho, 65 miles north of Utah, 18 miles west of Wyoming, and 5 miles west of John Grays Lake; 

locality No. 2, 15 miles east of south from locality No. 1. 

The section at locality No. 1, according to Dr. C. A. White, is as follows: 

Feet. 

A. (Uppermost beds.) Limestones and shales, with Terebratula semisimple.c ·white, T. angus-} 

_tata Hall, A~iculopec~en i~ahoensis Meek.: ......... ·: ...... : .......................... l, 000 

B. Limestones, With Eum~crot~s curta, and Avuulopecten ~dahoens~s Meek ................... . 

C. Greenish and reddish shales and sandstones, with Aviculopecten pealei White.............. 850 

D. Bluish-gray limestones, fossiliferous near the base, with Meekoceras graci/itat1:s ·white, Jl1. 

mushbachanum \Vhite, Arcestes? cirratus White........................................ 700 

E. Reddish and greenish sandstones................. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400 

~: ~~:~~~::e~ -s~-~~~~~~~-e_._ ·_:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::} 800 

H. Massive gray limestone............................................................... 400 

At locality No. 2 were found Meekoceras gracilitatis White and M. aplanatum ·white, in 

limestone similar to that marked Din locality No. 1, and this part of the section unquestionably 

belongs to the Lower Trias, although it is not likely that the entire thickness of beds there is 

referable to this division. In a later paper Dr. C. A. White expressed the opinion that the 

Meekoceras fauna of Idaho ought possibly to be placed in the Permian rather than in the Trias, 

because of the conformity with the Carboniferous beds below, and because of the presence in the 

fauna of certain Carboniferous elements. These were precisely the arguments used 10 years later 

by F. Noetling for placing the Lower Triassic faunas of India in the Permian, but there is just 

as little ground for this in the one region as in the other. This question has been fully discussed 

by the writer in a recent paper. 

In 1888 Prof. Alpheus Hyatt discovered a third locality for Lower Triassic ammonites in 

southeastern Idaho, in the Aspen Mountains, in Wood Canyon, about 9 miles east of Soda 

Springs. In 1900 and 1903 the writer visited this same locality, which lies only a few miles 

southwest of locality No. 2 of White. The joint collections of Prof. Hyatt and the writer 

yielded the following ammonites: a Danubites whiteanus Waagen, Danubites sp. nov., Meekoceras gracilitatis White, Meekoceras, three new species (of which one may be identical with 

M. boreale Diener), M. (Koninckites) mushbachanum White, M. (Gyronites) aplanatum White, 

and two other species of the same subgenus, Aspidites sp. nov., Flemingites sp. nov., Ophiceras 

sp. nov., Hedenstrmmia sp. nov., Clypites sp. nov., Ussuria two new species, ·and Nannites 

sp. nov. Besides those here listed there were found several new genera of the same families. 

This fauna is intimately related to the Lower Triassic faunas of India and eastern Siberia, 

with several species that may even be identical with those from Asia. It contains several 

genera hitherto known only from the Lower Trias of India, and others previously found only 

in the Proptychites beds of Ussuri Bay in Siberia; it is therefore referred with certainty to the 

Brahmanic stage of the Scythis series. It may be correlated with the Ceratite marls and the 

lower part of the Ceratite sandstone of the Salt Range of India. 

The following notes are contributed to this manuscript by C. L. Breger: 

The' 'Meekoceras beds" are in southeastern Idaho nearly 3,000 feet thick and include Lower 

Triassic and apparently also Middle Triassic, while at the top, underlying the red beds, is a 

zone which appears to be of Upper Triassic age, containing Myophoria cf. lineata Mstr. and 

a The new genera and some of the species of this fauna have been described in Prof. Paper U. S. Geol. Survey 

No. 40, by Hyatt & Smith.-B. W. 

48011°--12----34 
530 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Spiriferina cf. lippoldi Bittner. If this identification is correct, the overlying red beds (corresponding to the Nugget formation of Veatch and the Teton formation of the Yellowstone Park), 

which have by some writers been classified as Triassic, would perhaps find a more suitable resting 

place in the lower Middle Jurassic. 

The Pentacrinus shaly limestones of Peale, of the Hayden Survey, correspond to the Twin 

Creek formation of Veatch and the Ellis formation of the Yellowstone Park-1fontana district. 

They are commonly regarded as of Upper Jurassic age. In southeastern Idaho their thickness 

is much greater than that given by Peale, reaching 3,000 feet or more. 

K 12-13. WYOMING AND ADJACENT AREAS. 

Triassic strata are not generally distinguished in this region, but they are 

assumed to be represented in the upper part of the red beds, the lower portion 

being assigned to the Permian." (See pp. 490-492, Chapter XI.) An exception to the 

general uncertainty is found in the beds near Lander to which Williston applied the 

name Popo Agie, and in the highest strata of Red Mountain near Laramie, from 

both of which Williston has described Triassic vertebrates. 

Of the Park City district, Utah, Boutwell 93 b states: 

Within this district no sediments have been found which carry Triassic fossils. To the 

north and northwest, however, the Park City formations pass upward through several hundred 

feet of red shale into brown, red, pink, and white sandstones. These are frequently massive 

and heavily bedded, in striking occurrences are coarsely cross-bedded, and toward the top are 

quartzitic. Disregarding possible faulting, they aggregate about 1,550 feet thickness. The age 

of these sandstones has always been regarded as Triassic, as they overlie Permian and underlie 

Jurassic: 

In western Wyoming Veatch 839 b distinguished as Triassic ('?) the Nugget 

formation, consisting of red shales below (since correlated by Gale 356 with the 

Ankareh shale) and lighter-colored sandstones above (to which the name Nugget 

is now restricted). 

Throughout the Bighorn Basin and Mountains the red beds are known as the 

Chugwater formation. Both Darton 2390 and Fisher 331 place the formation doubtfully in the Triassic but cite fossils from the lower portion which suggest Permian. 

(See p. 495, Chapter XL) Darton 2440 says: 

Fossils found at various horizons in limestones in the Chugwater red beds do not afford 

conclusive evidence as to age. Those in the lower limestones in the Bighorn Mountains and 

other uplifts are believed to be "Permian" in the sense in which the term is used in the Mississippi Valley. Many fossils occur in the limestone 150 feet below the top of the formation, on 

the east bank of Bighorn River, 3 miles below Thermopolis. According to Dr. G. H. Girty, 

the principal species is Natica lelia, usually considered diagnostic of the Triassic, but probably 

it is older. Bakewellia and probably Pleurophorus may also be present, and an Aviculipecten 

occurs resembling A. curticardinalis, which is characteristic of the Permo-Carboniferous of Utah. 

Dr. Girty is inclined to correlate the fauna with the Permo-Carboniferous of the Wasatch Mountain section. The 150 feet of red shales and sandstones which overlie this limestone may possibly represent part of the Triassic. In the lower portion of the Chugwater formation, 10 miles 

southwest of Casper, a cast of Schizodus wheeleri was found. This form is usually regarded as 

Pennsylvanian. 

The Chugwater formation also occurs in the Laramie Basin, wl;tere Darton has 

recognized it and included in it 200 feet of light-colored sandstone not typical and 

not observed to the northeast. The top of the formation nearly everywhere in 

this region is the base of the fresh-water Morrison formation, 247 the intervening 

Sundance formation (Jurassic) generally being absent. 
TRIASSIC. 531 

Darton 244 b. has traced the Chugwater throughout central Wyoming and, 

describing it under the heading "Permian-Triassic," gives its general relations as 

follows: 

The Chugwater formation ranges in thickness from 900 to 1,200 feet and consists of sandy 

shales or soft, massive sandstones, nearly all of bright-red color. Gypsum deposits occur in 

most places. There are extensive exposures along the lower northeastern slope of the Wind 

River Mountains in the Owl Creek, Bridger, and Rattlesnake uplifts, in the flexures south of 

Casper and Douglas, above Alcova, in the Shirley and Freezeout hills, in the anticlines north 

and cast of Medicine Bow, and along the east side and· across the south end of Laramie Basin. 

It appears also at intervals along the east slope of Laramie Mountains. In the greater part of 

the south-central Wyoming region the Chugwater formation lies on Tensleep sandstone, but 

in the southern end of the Laramie Basin it lies on red beds of the Casper formation, from 

which in places it is not easily separated. 

Detailed descriptions of the formation for all the ranges mentioned are given 

in the paper cited. 

In the red beds thus placed by Darton in the Chugwater formation, in the 

ranges between Rawlins and Lander, Wyo., Williston 941 a has traced a series of beds 

near the top of the formation carrying Triassic vertebrates. He says: 

The Vniversity of Chicago paleontological expedition to Wyoming the past summer was 

fortunate in securing a valuable collection of stegocephalian and reptilian remains from the 

Trias, a part of which is described in the present paper. 

The beds whence the fossils were obtained, from 40 to 80 feet in thickness, are about200 

feet below the top of the red beds and about 600 feet above their base. Their description will 

be given in a later paper by Mr. N.H. Brown, their discoverer, and the writer. Meanwhile the 

horizon may be distinguished by the name Popo Agio beds, as suggested by Mr. Brown, from 

the Popo Agie River, along whose branches they are most characteristically shown. 

The forms described comprise DolichobracMum gracile, Eubrachiosa1'"rus browni, 

Brachybrachium brevipes, and Paleorhinus bransoni. 

Williston 942a also found Triassic vertebrates in the red beds (Chugwater) of 

Red Mountain south of Laramie. He says: 

We found ihere numerous fragments of bones scattered along a thin stratum near the top 

of the red beds. The marine Jurassic is here wanting, as at Canon City, the sandstone of the 

Morrison or Atlantosaurus beds overlying the red beds without marked unconformity. The 

lower members of these beds consist of a grayish or yellowish sandstone and are unfossiliferous, 

the first vertebrate fossils occurring 75 feet or more above the red beds horizon. [This stratum 

yielded] very characteristic labyrinthodont plates and vertebrre, proving conclusively the 

Triassic age of the deposits. 

The differences of these fossils from those obtained in the Lander region [Popo Agie beds of 

Williston] from a horizon fully 250 feet below the top of the beds, are such that their contemporaneity of deposition is very improbable. * * * I am much inclined to believe that the 

Popo Agio beds, which may be contemporaneous with those yielding vertebrate fossils in Utah, 

Arizona, Now Mexico, and Texas, are of early Keuper age, while the Connecticut Valley, the 

Red .Mountain, and Ilallopus beds of southern Colorado are later in time. 

Darton in a later note 242 states that the red beds of Red Mountain grade into 

upper Carboniferous sandstones and limestones, which along the Rocky Mountain 

front become the Lower Wyoming division of Eldridge and the Fountain formation 

of Gilbert and Cross. Darton cites Knight's discovery of upper Carboniferous 

fossils in the red beds of the Laramie Basin and concludes that the evidence is contradictory. 
532 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Knight's article 506 contains a very detailed section, measured "in the vicinity 

of Red Mountain," from the pre-Cambrian granite on which the red beds rest. The 

section shows the typical variations of sandstone and conglomerate, prevailingly red 

or reddish. At 728 feet from the base occurs a fossiliferous layer of "grayish to 

reddish sandstone containing the following genera of fossils: Allorisma, Pleurophorus, Bellerophon, Myalina, Aviculopecten, Dentalium (~), Pleurotomaria (~), 

several small gastropods, and some remains of vertebrates." Knight says: 

The genera [in the fossiliferous layer in his section] are so characteristic that it is not necessary to discuss their geological position; they belong to the Paleozoic and resemble to a marked 

degree the fossils of the Kansas and Nebraska Permian. This places all the strata below the 

fossiliferous band in the Paleozoic. There remains a formation of about 800 feet in thickness 

[total 850 feet as measured, comprising red sandstone, shales, and gypsum beds], with the 

gypsum beds at its base, in a questionable position, and some may wish to retain these beds in 

the Triassic. 

On the evidence of the fauna found by Knight 850 feet below the top, and the 

vertebrate remains collected by -Williston near the top, we must conclude that the 

passage from Permian to Upper Triassic occurs in the upper half of the red beds. 

K 18. CONNECTICUT AND MASSACHUSETTS. 

The Triassic of the Connecticut Valley belongs to the Newark group. (See 

pp. 522-527.) Davis 248 discussed the conditions of deposition. Emerson 319a classified the strata and described them in detail, particularly with reference to their 

occurrence in Massachusetts. He says: 

The Triassic rocks have been divided by the author in an earlier publication as follows: 

1. The Sugar Loaf arkose, or the sandstone and conglomerate made up of the debris of 

granite. 

2. The Mount Toby conglomerate, or the coarse conglomerate made up of large schist and 

quartzite pebbles. 

These two numbers are, speaking generally, the west and east shore deposits. 

3. The Longme_adow brownstone, or the red sandstone generally marked by so-called 

fucoidal forms, which are probably concretions. 

4. The Chicopee shale, or the calcareous red shale. 

These two are the offshore and central beds of the series. 

5. The Granby tuff, or the diabase tuff. 

6. The Holyoke and Deerfield diabase beds. 

7. The Black rock volcanic necks and the posterior diabase beds. 

The last three distinctions cover the fragmental, interbedded, and intrusive occurrences 

of the diabase, respectively; except that the posterior sheet is placed with the injected necks, 

with one of which it is directly connected. 

Russell 683 considered these particular strata in comparison with those of New 

.Jersey and other localities where the Newark occurs. 

In the Pomperaug Valley in western Connecticut is a small outlier of the Newark 

group which has been described in detail by Hobbs, 456 who distinguishes the following 

formations in descending order: 

Posterior shales. 

Main basalt sheet. 

Anterior shales. 

Anterior basalt sheet. 

South Britain conglomerate. 
TRIASSIC. 533 

K-L 13. BLACK HILLS, SOUTH DAKOTA. 

The Spearfish formation, the uppermost division of the red beds in the Black 

Hills, was described by Darton 2320 as probably Triassic. He states: 

The formation consists of from 350 to 500 feet of red sandy clays, with intercalated beds 

of gypsum which sometimes are 30 feet thick. * * * It is thought to be Triassic in age 

because it lies unconformably beneath marine Jurassic deposits and is underlain by the Minnekahta limestone, which is known to be of Permian age. 

The tendency is now to correlate the Spearfish formation with the upper part 

of the Chugwater formation, which is also regarded as Triassic, the lower part of the 

Chugwater probably belonging to the Permian. 

L 11. NORTHEASTERN OREGON AND WESTERN IDAHO. 

Lindgren 540a discusses briefly the occurrence of the Triassic in western North 

America and describes the Triassic strata in eastern Oregon and adjacent Idaho as 

follows: 

With widespread Triassic areas in California, Idaho, and Nevada, and with similar areas 

north of the international boundary line, it seemed strange that no rocks of the same age were 

found in Oregon or in Washington. This gap has been partly bridged by the discovery of very 

extensive Triassic beds in the Eagle Creek Range, extending from there across Snake River into 

Idaho, to the vicinity of the Seven Devils. If the sedimentary rocks in the vicinity of Huntington belong to the same age, as is possible though by no means certain, the area of the Triassic 

would be still further extended. 

A characteristic feature of the Triassic of the Eagle Creek Range is the occurrence of large 

masses of limestone and some shale, with an abundance of more or less altered lavas poured out 

during the time when these beds were being deposited. 

The Triassic sediments are best exposed on Eagle Creek. All along the foothills of the 

lower Powder River the Triassic lavas contain smaller bodies of limestone and shale, but on 

Eagle Creek below the forks, the sedimentary series prevails and consists of calcareous shales 

and limestone in horizontal or slightly inclined position. Volcanic breccias are interbedded with 

the limestone. The total thickness of the series, including the volcanic beds, is probably 

several thousand feet. Many of the exposed limestone masses are several hundred feet in thickness. Above the junction * * * the limestones become converted into marbles and the 

volcanic breccias into schists, while the whole series acquires a dip of 60° E. 

Dr. T. W. Stanton examined fossils collected one-third mile below the mouth of East Eagle 

Creek and reports them to consist of numerous specimens of Halobia and two indeterminable 

fragments of an ammonite. The Halobia is apparently an undescribed species, but the genus 

itself is characteristic of the Trias. Another lot, collected from the limestone bluff on East 

Eagle Creek 2~ miles above its mouth, contains Pentacrinus columns with spines and fragments 

of tests of echinoids. From the Miles placers, 1! miles below the mouth of East Eagle Creek, I 

obtained through Mr. F. R. Mellis, of Baker City, a cast of a gigantic gastropod found in the 

limestone bedrock during drifting operations on this claim. Dr. Stanton remarks that it has the 

form of a very large Turritella or Pseudomelania. Nothing of this character approaching it 

in size has been described from the west coast, but similar forms described as Chemnitzia and 

Pseudomelania are known from the Trias and Jura of Europe. The total length of this cast is 

8 inches and its diameter at the thickest end 3 inches. 

Along Snake River canyon, below the mouth of Pine Creek, Triassic lavas and tuffs are 

again exposed in the bluff below the N eocene basalt flows which cap the hills. These Triassic 

igneous rocks contain thin beds of black shales and limestone with imprints of a large species 

of Daonella or Halobia. A limestone mass 4 miles below Ballard Ferry contained a Lima with 
534 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

fragmentary imprints of a Halobia (?), and is also probably Triassic. The last two fossils were 

obtained from Mr. E. Antz, of Ballard Ferry. 

From these data and from what is known of the field relations of the strata it is safe to 

conclude that a Triassic series is developed on a large scale in this region; but from the paleontological evidence at hand it would not be possible to say which one of the numerous subdivisions 

of the series is present. 

J.P. Smith states a that he visited the Triassic beds of the Blue Mountains in 1908 

and determined them as certainly of Upper Triassic age (Karnic and lower Noric 

of Europe). 

L 12. YELLOWSTONE NATIONAL PARK. 

The occurrence of Triassic strata in the Yellowstone Park region is doubtful. 

Between the Ellis formation (which is now known to contain a Middle and Upper 

Jurassic fauna) and the Quadrant quartzite (Carboniferous) occurs the Teton formation, which is thought to be at least in part of Triassic age. The section exposed on 

Cinnabar Mountain in Yellowstone Park is, according to Iddings and Weed.39aa 

Section of the Mesozoic sedimentary rocks exposed in Cinnabar Mountain and Electric Peale. 

I Dakota conglomerate and sandstone. __ . _ ...... _ ....... ______ . _________________________________ Ff~~ 

Reddish shales and impure limestones .............. _ ............................... _ ... _. __ .... 85 

Limestones and calcareous sandstones, occasionally a conglomerate; carries an abundance of 

fossil remains, which are generally fragmentary near the base.................................. 75 

Red argillaceous shale ....................... _ .............................. _ . . . . . . . . . . . . . . . . . . 8 

Gray calcareous shales and impure limestones, characterized by an abundance of fossil remains, 

I afe~~i~~ia~~ ~~!fe~-~:~~~ ~:~~~~: _ ?~~-~~~-s-a~~ _s~~-a~~~~~-~~~~ _t~-~ ~~n-te~-b~-~1-i~~~ ~~~~-s~~~~~:: 1~~ ~~------~~~~~~~--~~~~~--~~~--~~~--~~~~~~~---

Sandstone, saccharoidal in texture, generally light gray or buff in color, but red or broWn on weathered surface ..................................................................... _ .. _ 50 

Red beds, consisting of very fissile sandstones and impure arenaceous clays .......... _._ ........ _ 75 

Limestone, compact in texture, gray in color, and carrying remains of lingulas................. . . . 20 

Limestones, dark gray in color, generally fetid, often arenaceous and frequently characterized by 

rod-like masses of chert, which are seen to consist of grains of sand embedded in the siliceous matrix, 

the concretions having a white chalky surface ........ __ ......................... __ ._ ... _ .. _ 125 

Quadrant quartzites. [These are not a part of the Teton formation and in this table were bracketed 

with it through a typographic error.] 

In the Yellowstone National Park folio 392 the Teton formation is said to be 

the "probable equivalent of the well-known red beds of Wyoming and Colorado" 

and is described as follows: 

The formation consists of the basal sandstone, usually dull brown in color and more or less 

calcareous, characterized by rods and rolls of white chert, and carrying interbedded gray limestones containing linguloid shells. Above this basal bed are gray and greenish calcareous 

shales, often micaceous and capped by a red arenaceous shale that forms a conspicuous part 

of the formation. This series of beds is capped by a sandstone, generally bright yellow, with 

red weathered surface, this rock delimiting the overlying Ellis formation. 

Lithologic resemblances and similar stratigraphic relations suggest correlation 

of the Teton with the Nugget and other formations of southwestern Wyoming. 

(See p. 530.) 

a Personal communication. 
TRIASSIC. 535 

Concerning the scanty paleontologic evidence of the age of the Teton formation Stanton 393r says: 

The Teton formation, of supposed Triassic age, yielded a few specimens of a Lingula at a 

locality on the summit of Quadrant Peak. This fossil resembles Lingula brevirostris M. and 

H., from the Jurassic of the Black Hills, but in the absence of other fossils it should be given 

little weight in determining the age of the beds. Linguloid shells are so slightly differentiated 

that it would not be safe to distinguish, by them alone, even between Paleozoic and Mesozoic. 

The determination of the age of this formation must, for the present at least, rest on the evidence of stratigraphy and lithology. The paleontologist can only say that the underlying 

beds yield Carboniferous fossils, while the overlying formation has a well-developed Jurassic 

fauna. 

L 20. NOV A SCOTIA. 

The Triassic of Nova Scotia comprises the rocks which have long been known by 

the descriptive term" New Red sandstone" and which belong to what is now called 

the Newark group. According to Dawson, 263 the terrane consists "principally of 

coarse and soft red sandstones with a calcareous cement. * * * In the lower 

part of the formation there are conglomerates made up of well-worn pebbles of the 

harder and older rocks." The Triassic strata lie with gentle dip, in marked unconformity to the subjacent steeply dipping Carboniferous rocks. They are associatPrl with sheets of trap rock, in part massive, in part amygdaloidal or tuffaceous. 

Describing the characteristic relations as they are exposed at Cape Blomidon, 

Dawson253a says: 

The history of this fine precipice is, then, shortly as follows. In the Triassic era, thick 

beds of sandstone ·were deposited off the coasts of Horton, just as the red mud and sand of the 

flats are now deposited. Volcanic phenomena on a great scale, however, broke forth from 

beneath the waters, scorire and dust were thrown out and spread around in thick beds, and 

currents of lava were poured forth. Subsequently the whole mass was elevated, to be again 

submerged under the bowlder-bearing sea, by which and the present atmospheric and aqueous 

agr•ncies it was worn and wasted into its present form. 

Dawson's account of the general relations of the Triassic of the Bay of 

Fundy 253b is as follows: 

The red sandstones now described appear to have been deposited in an arm of the sea, 

somewhat resembling in its general form the southern part of the present Bay of Fundy but 

rather longer and wider. This ancient bay was bounded by disturbed Carboniferous and 

Silurian strata, and the detritus which it received was probably chiefly derived from the softer 

strata of the Carboniferous system. The arenaceous nature of the New Red sandstone, as 

compared with the character of these older deposits, indicates that the ancient bay must have 

been traversed by currents, probably tidal like those of the modern bay, which washed away 

the argillaceous matter so as to prevent the accumulation of muddy sediment. When we 

consider the large amount of land in the vicinity of the waters in which the New Red sandstone 

was deposited, the deficiency of organic remains in its beds is somewhat surprising, though this 

is perhaps to be attributed rather to the materials of the deposit and its mode of accumulation 

than to any deficiency of vegetable or animal life at the period in question. 

The volcanic action which manifested itself in the bed and on the margin of the bay of 

the New Red sandstone is one of the most remarkable features of the period. It has brought 

to the surface great quantities of melted rock, without disturbing or altering the soft arenaceous 

beds through which it has been poured and whose surface it has overflowed. 
536 INDEX TO THE STRATIGRAPHY OF NOHTH AMERICA. 

Reports later than Dawson's give much local detail regarding the Triassic as 

it occurs in the counties of Nova Scotia adjoining the Bay of Fundy. Fletcher335f 

describes the distribution and states: 

The relations of the sedimentary rocks of this formation, with their associated traps, to 

the older formations have also been described in great detail by Jackson and Alger, Gesner,a 

Sir J. W. Dawson,b and others. The contact with the older rocks is always clear and unmistakable, so that there is no ambiguity with regard to the limits of the formation. Sometimes, 

particularly on the north side of the basin, this junction is a fault; sometimes coarse beds lie at 

a low angle upon and fill inequalities in the underlying rocks of which they are composed. 

Many of the sandstones are very calcareous. The total thickness of the formation is doubtful. 

In Clifford Brook, east of Valley station, the lowest Triassic rock is a pea and nut conglomerate lying horizontally on the red slates of Union. On the road to the Telegraph road east 

of the manganese mines, and also in the neighborhood of the mines, many pieces of Triassic 

sandstone are in the soil and perhaps point to outliers among the Devonian. 

From the railway station at Valley across the bridge and out the road to the Telegraph 

road the strata are Triassic, and to the eastward along the Telegraph road and for some distance 

up the river these rocks are also exposed. In Half Moon Hill Brook the contact with the 

Devonian is well seen, the Triassic being bright-red, crumbly, coarse sandstones, scarcely more 

coherent than the sand of a sand pit, with layers of grit, less bright than the other beds, containing pebbles an inch in length derived from the red argillites. Lower down is a gray, crumbly, 

flaggy pebbly sandstone, dipping at a low angle, with thin beds and blotches of light green. 

In the branch of Farnham's Millbrook which flows from Penny's Mountain are dark brickred, soft, marly, very fine sandstones, containing patches of gray calcareous sandstone and 

of coarse conglomerate, with a vertical dip which appears to indicate a fault. In another 

little brook farther west, brick-red sandstone and nut and egg conglomerate form ledges which 

dip at a very high angle. 

M 9-10. VANCOUVER ISLAND. 

In 1885 Dawson made a reconnaissance of the northern portion of Vancouver 

Island and determined the presence of Triassic limestone and argillite in an immense 

series of volcanic rocks, all of which are penetrated by granite intrusions. In 1902 

the west coast was reconnoitered by Webster 868 and Haycock, 415 who identified the 

same series of rocks but added nothing to Dawson's original description, 256a from 

which the following extracts are made: 

By far the greater part of the area of the northern portion of Vancouver Island is occupied 

by rocks of volcanic origin, which at first sight and as judged by eastern American analogies 

might often be supposed to represent formations occupying a very low stage in the geological 

scale. These volcanic rocks, originally composed of minerals already crystalline, have since been 

subjected to metamorphism more or less intense, to which, in consequence of their composition, 

they have easily yielded, and now form, for the most part, rocks which might be spoken of as 

"traps and greenstones." These frequently show locally little or no evidence of their bedded 

character. Such rocks, however, when closely examined and followed from point to point, 

are found to form portions of a stratified series of great thickness, which includes, besides the 

preponderant volcanic materials, certain argillites and limestones, holding Triassic fossils. 

The greater part of this old volcanic series appears to have been built up of basaltic and 

trachytic lava flows, alternating with rough volcanic breccias and tuffs largely composed of 

fragments derived from such flows. These rocks are now represented by hard amygdaloids 

and agglomerates of general dark-greenish colors, though often grayish and sometimes reddish 

or purplish; by felsites, more or less porphyritic; and by hard, regularly stratified ash beds, 

which, where the alteration has been most pronounced, are locally changed to hornblendic or 

micaceous schists. 

* * * * * * * * * a Geology and mineralogy of Nova Scotia, p. 239. 

b Acadian geology, p. 99; Geol. Jour. London, vol. 4, p. 50, with a map. 
TRIASSIC. 537 

In association with these volcanic rocks limestones, argillites, and quartzites occur, possibly 

at several di::Terent horizons, but one of these, which is of considerable thickness and great 

persistency and possesses very distinctive characters, has now been recognized at a number of 

places, from the northern part of the Strait of Georgia round the north end of the island and in 

Quatsino Sound. This intercalated zone is of considerable thickness, having been estimated 

at 2,500 feet at one place on the north coast of the island, where it appeared to be fully displayed. 

Massive limestones, which, when the strata are considerably altered, pass into marble, form its 

lower portion. The upper part of the limestone becomes interbedded with argillites in regular 

flaggy layers, and black flaggy argillites interbedded with quartzites overlie these. Where the 

top of this argillite series is seen it often holds tufaceous and fine agglomeratic beds, and is 

followed in ascending order by a great thickness of the altered volcanic rocks. In other localities, 

the limestone is found to become interbedded with volcanic materials beneath, and though no 

complete section of the entire series can be offered, it is quite clear, from observations made 

in a great number of places, that these sedimentary materials form an intercalation in the great 

volcanic series. 

The importance of this fact is apparent when it is stated that the only means of :fixing the 

age of the entire series is afforded by the fossils obtained from the limestone and argillite intercalation. These occur chiefly in the argillites and in passage beds between these and the more 

massive limestones, and are referable to the so-called Alpine Trias. No fossils except these of 

this age have yet been found in association with this sub-Cretaceous series in the northern part 

of Vancouver Island, while the Triassic forms have been recognized in numerous localities. 

The evidence on which these rocks are, therdore, colored as Triassic on the map, is identical 

with that on which the reference of the precisely similar series of the Queen Charlotte Islands is 

based. It is quite possible, in both cases, that the lower portion of the series may include 

rocks of greater age than Triassic, and the association of Triassic and Carboniferous volcanic 

rocks in the southern part of the interior of British Columbia lends a degree of probability to 

the conjecture that rocks of the Carboniferous period may form a portion of those here described. 

There is, however, no direct evidence of this, either in the northern part of Vancouver Island 

or in the Queen Charlotte Islands. 

The rocks beneath those of the Cretaceous age in the southern portion of Vancouver Island 

are likewise, in great part, altered volcanic materials, which are interbedded with limestones 

and in some places with argillites. The conjecture that beds of Carboniferous age may occur 

together with those referable to the Trias, in the Queen Charlotte Islands and the northern part 

of Vancouver Island, is strengthened by the fact that the late Mr. J. Richardson obtained a 

few poorly preserved fossils from limestones interbedded with the altered volcanic rocks of the 

Ballinac Islands, between Nanaimo and Comox, and at Mount Mark, in the center of Vancouver 

Island, between Qualicum and Alberni, which were supposed by Mr. Billings to be either 

Carboniferous or Permian, and probably the former. 

Though an unconformity has been proved to exist in at least one place between the Triassic 

and Carboniferous volcanic rocks of the southern interior of the province, no such break has 

yet been found in any part of the sub-Cretaceous series of Vancouver Island, and if rocks of 

both these periods actually occur there, they can not be at present separated. 

The series as a whole indicates throughout a continuance or recurrence of volcanic phenomena on an enormous scale, and must be at least several thousand feet in thickness. 

As a convenient name for the whole I shall employ the term "Vancouver series," including 

for the present under this name not only the entire mass of volcanic materials which unconformably underlie the Cretaceous but also the interbedded limestones and flaggy argillites and 

quartzites. This name may also be understood to include the similar beds of the Queen 

Charlotte Islands, as well as those of the southern part of Vancouver Island, to which it was 

originally applied by Dr. Selwyn in 1871. If this great mass of rocks should eventually prove 

separable into Triassic and Carboniferous portions, I would suggest the retention of the name 

Vancouver series for the former. 

The beds of the Vancouver series are the oldest known to occur in the district here described 

and in the Queen Charlotte Islands and are frequently found in contact with or resting on 
538 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

granitic rocks. They have not, however, been deposited upon a granitic floor, as the granites 

are evidently later in date than the rocks of the Vancouver series, and nothing whatever is 

known of the character of the surface upon which its volcanic and other associated beds were 

originally formed. 

The fossils obtained from the Vancouver Triassic are described by Whiteaves. 913,914 

M 10. KAMLOOPS DISTRICT, SOUTHERN BRITISH COLUMBIA. 

The Nicola: formation, which consists largely of volcanic rocks with associated 

fossiliferous marine sediments, was originally assigned by Dawson in 1878 to the 

Triassic on somewhat meager evidence. In 1894 Dawson 261 a reviewed all the 

evidence which had then accumulated and concluded: 

It will be observed that the original reference of the series as a whole to the Triassic has 

been gradually strengthened by later discoveries. These, taken in connection with the 

stratigraphy, in fact seem to show that while the great bulk of the Nicola formation is undoubtedly equivalent to the Triassic, it passes up in a few places into rocks of Lower Jurassic date. 

The structure and lithology do not appear to afford any means of separating the two faunas 

or of drawing any line through the great mass of rocks, chiefly of volcanic origin, in which 

they occur, and it is therefore appropriate and necessary to treat of the Nicola formation as a 

whole, although recognizing the fact that it probably extends higher than the typical Trias. 

An unconformity is indicated between the lowest strata of the Nicola and the 

underlying Paleozoic rocks. Regarding the composition of the Nicola formation 

Dawson says: 

Within the area of the Kamloops sheet the Nicola formation consists essentially of a great 

mass of volcanic deposits, with a total thickness of probably 10,000 to 15,000 feet. In the 

lower part of the formation some thin and probably irregular beds of limestone occur. Here 

and there throughout the formation a limited thickness of argillites is found, and, forming 

the summit, so far as yet ascertained, is another bed of limestone. 

The greater part of the volcanic rocks may be described generally under the useful name 

of "greenstones." Lithologicaliy, these rocks are for the most part found to be altered diabases, with, exceptionally, augite porphyrites, also considerably altered. In regard to their 

state of aggregation, these volcanic materials represent all the usual productiil of eruptions, 

including effusive rocks, sometimes amygdaloidal, and tuffs. There is also, throughout the 

entire series, more or less evidence of subaqueous deposition and bedding, while no proof has 

so far been obtained in this district of the existence of subaerial accumulations. 

The following summarized general sections, based on more detailed descriptions given 

in the sequel, best represent what is known of the Nicola formation, in the eastern and western 

parts of its area respectively. The sections are in descending order. · 

Thompson River, south of the Ashcroft Cretaceous area. Vicinity of Nicola Lake. 

Feet. Feet. 

Limestone (20 feet or more)....... . . . . . . . . . . . . . . . 20 Fine-grained feldspathic rocks, generally well 

Fine-grained feldspathic rocks, sometimes well . bedded ..................................... _. 1,200 

bedded, generally gray........................ J, 800 Diabases, chiefly effusive and sometimes amygdaTuffs, or ash rocks, passing into agglomerates, loidal; some tuffs; two thin beds of limestone 

with some fine-grained felsites, gray, purplish near the base ................... _._ ...... _ .. _ .. 3,700 

and green; a few small limestone beds near the Chiefly green diabase agglomerates, occasionally 

base......................................... 7, 840 amygdaloidal. Thickness at least 2,600 feet and 

Chiefly green diabase agglomerates, often coarse. possibly 6,000 feet (say)....................... 2, 600 

Several calcareous beds and limestones. Dark 

felsites at base ............................... . 3,930 Approximate total (minimum) ........ ____ . 7, 500 

Approximate total............ . .. . .. .. . .. . . 13, 590 
TRIASSIC. 539 

In explanation of the above sections, it may be added that although placed in parallel 

columns, the equivalency of the several groups of beds is intended merely to be suggested in 

the most general way. If the maximum thickness be assigned to the lower group in the Nicola 

section, there would be a nearer approximation to correspondence in total thickness, but the 

rendering of this part of the section is doubtful. Further it must be noted as possible that 

the amphibolites and argillites of the Douglas Lake vicinity, with a thickness of about 7,000 

feet, may eventually have to be added to the Nicola formation in that region. * * * 

In the year following that in which the Triassic age of these rocks was recognized in the 

inland region of British Columbia and the name Nicola series proposed for them, Triassic rocks 

of essentially the same character were discovered in the coast region, in the Queen Charlotte 

Islands. At a still later date, the formation last referred to was found to be continued to the 

southeastward, in the line of the same mountain axis, and to form the greater part of the older 

rocks of the northern portion of Vancouver Island. Like the Nicola formation, the Vancouver 

formation, as it was then called, is chiefly composed of old volcanic products. * * * [See 

pp. 536-538.] With these volcanic products limestones and argillites holding characteristic 

Triassic fossils are interbedded. 

In the Vancouver formation, or series, the limestones and argillites are somewhat more 

important than in the Nicola formation, but otherwise the resemblance between the two, both 

in regard to their original mode of production and their present appearance, practically amounts 

to identity. Notwithstanding this fact, it is believed to be appropriate to retain distinctive 

local names for the two great developments of Triassic rocks in British Columbia. In both 

cases the lower and upper limits of the formation remain more or less indefinite, chiefly because 

of the absence throughout the great masses of the strata of any organic remains, and thus one 

may extend in its lower or upper beds through a part of the geological time scale considerably 

greater than the other. It is moreover found to be a general rule in this part of the Cordillera 

that exact equivalency of formations is scarcely to be sought for at any considerable distance 

across the prevalent northwest and southeast trend of the main orographic features, and in 

this case the nearest recognized representatives of the two formations are separated by a gap 

of about 150 miles transverse to this direction. 

In an immediately succeeding paragraph Dawson refers to the occurrence of 

"Triassic" red beds in latitude 49° 30' in the Rocky Mountains. The rocks are 

described in an earlier report, 255 and were later placed by Willis 940 in his Kintla 

formation, which belongs to the Belt series (pre-Cambrian). 

N 8-9. QUEEN CHARLOTTE ISLANDS. 

On Dawson's map of 1878 the southern portion of the Queen Charlotte Islands 

is represented as consisting of Triassic rocks. The report states: 252a 

In a preceding report on British Columbia it has been found necessary to melude for the 

present the Paleozoic and Triassic rocks under a single heading.a They lie together unconformably beneath well-characterized Cretaceous beds but are so much involved that no attempt 

has been made to separate them except locally. In the southern part of the interior of British 

Columbia both Carboniferous and Triassic fossils have been found among these older rocks, 

but no forms of greater antiquity. In the Queen Charlotte Islands, now reported on, fossils 

have been discovered in the rocks unconformably underlying the Cretaceous in a number of 

places. These serve to characterize a certain zone of argillites and limestones, which is frequently repeated in sections along different parts of the coast, as distinctively Triassic, and 

show it to represent the so-called Alpine Trias which is so largely developed in California and 

Nevada. No forms distinctively Carboniferous or Paleozoic have yet been discovered, but 

from the iatimate association of Carboniferous and Triassic rocks in the southern part of the 

province, and more particularly from the occurrence of great masses of rocks largely volcanic 

a Report of Progress, 1877-78. 
540 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

in origin and believed to be Carboniferous in age, in the southern part of Vancouver, which 

forms part of the same axis of elevation with the Queen Charlotte Islands, it is highly probable 

that the rocks of this age may come to the surface in some places. Mr. Whiteaves, who has 

examined the fossils, does not find any clearly Triassic forms among those from Rose Harbor, 

the old copper mine in Skincuttle Inlet, and the south end of South Island in Skidegate Inlet. 

The limestones of these localities may therefore possibly be of Carboniferous age, and if so a 

large portion of the associated rocks of volcanic origin must be attributed to the same period. 

As it is at present impossible to unravel the structural complexity of the sub-Cretaceous rocks 

of the islands, it has been thought best to color them together on the map as Triassic, in 

correspondence with their characteristic fossils. 

Though no report is here made on observations in the northern part of Vancouver Island, 

it may be mentioned that Triassic forms identical with those from one of the localities on 

Houston Stewa-rt Channel, have been obtained on Forward Inlet and Browning Creek, Quatsino 

Sound. 

Any unconformity which may have existed between different beds of this sub-Cretaceous 

mass of rocks may now be masked by their complete folding and the great disturbance and 

fracture to which they have been subjected. The occurrence of great masses of contemporaneous volcanic material during both the Triassic and Carboniferous periods, in British Columbia, has been demonstrated in former reports; and in the event of the lower and possibly Carboniferous rocks proving to be really Triassic, their general character would accord closely 

enough with that of those known elsewhere. 

* * * * * * * * * 

Tabular view of formations represented in the Queen Charlotte Islands. 

II Sands and gravels. 

Plastic and bowlder clays, gravel beds, etc. 

I 

Post-Pliocene. 

Unconformity, with evidence of some flexure and disturbance of Tertiary beds. 

Tertiary, probably Miocene. 

Volcanic rocks of the north part of Graham Island. 

Sandstones, with marine fossils and lignites of Skunun Point. 

Shales, clays, and lignites of ~ia-min River and Chin-oo-kun-dl Creek. 

Complete unconformity, with evidence of great disturbance. Chief period of mountain making. 

A. Upper shales and sandstones. 

B. Coarse conglomerates. 

Cretaceous. C. Lower shales and sandstones. 

D. Agglomerates. 

E. Lower sandstones. 

Unconformity, but without evidence of great disturbance. 

Agglomerates and ash rocks of Logan Inlet, etc. (These possibly 

represent subdivision D, supra.) 

Triassic, but possibly passing below into Carbon- Flaggy calcareous argillites and thin limestones. 

iferous. Massive limestones. 

Massive dioritic and feldspathie volcanic accum;.rlations, probably 

including minor limestone beds, occasionally schistose. 

TRIASSIC. 

The rocks seen in the shores of Houston Stewart Channel are everywhere very much 

disturbed, shattered by faults, and traversed by innumerable dikes. This region lies in the 

line of the mountainous axis of the islands, and though no extensive granitic masses appear 
TRIASSIC. 541 

here, the intensity of the force brought to bear on this region is well exemplified. About the 

middle of the southwest reach of the channel, in a bay on the southeast side, are extensive 

exposures of limestones and flaggy argillites, with general westerly dips. The limestones are 

generally in thin beds, bluish black on fresh fracture, and frequently fetid when struck. They 

are cherty and contain blackish rounded or rootlike concretions of silica and blend with the 

shales or flaggy argillites, which appear to occupy a superior position. The argillites are 

calcareous throughout, and generally each bed is a few inches thick, though in some cases 

finely shaly. Fossils were found in abundance in some of the shaly layers and in the limestones. Mr. Whiteaves enumerates the following species from this locality. They are 

evidently synchronous with the so-called Alpine Trias of Nevada: 

l. Amplexus (?) sp. nov. 

2. Monotis subcircularis Gabb. 

3. Halobia lommeli \Viss. 

4. Sphcera whitneyi (?) Meek. 

5. Arcestes gabbii Meek. 

6 and 7. Fragments of two species of ammonitoid shells, one of which appears to be new. They probably 

belong to different genera. 

8. Belemnites sp. nov. 

Feldspathic dikes, generally of pale greenish-gray color, traverse the rocks in all directions 

and stand out like ruined walls when the softer beds have been weathered away from them. 

These so complicate the section as to render accurate measurement impossible, but there is 

probably 500 feet or more in thickness of the limestones and argillites. 

Detailed descriptions of various occurrences of so-called Triassic rocks, which 

probably include Paleozoic rocks also, are given on the succeeding pages of Dawson's report. In 1905 Ells 316 examined the coal fields of the northern (Graham) 

island, but he did not investigate the pre-Cretaceous rocks except incidentally. 

N-0 11. PEACE RIVER PASS, BRITISH COLUMBIA. 

On Peace River, in the canyon by which it traverses the eastern ranges of the 

Rocky Mountains, McConnell 562a noted the presence of "dark Mono tis-bearing 

calcareous shales and impure limestones of Triassic age." This occurrence is in the 

range of the Triassic strata on the Liard. (See 0 9, pp. 542-543.) 

0 5. COOK INLET, ALASKA. 

Stanton and Martin 786a describe the Triassic of Cook Inlet as follows: 

Upper Triassic rocks have been seen on the north shore of Bear Cove and on Bear Bay, 

both on the west shore of Cook Inlet, and on the Alaska Peninsula at the entrance to Cold 

Bay and extending several miles eastward. They are also probably present at numerous localities on the south shore of Kachemak Bay, as at Halibut Cove and Seldovia, where there is a 

great development of thin-bedded and contorted cherts, with some siliceous limestone and 

igneous rocks. This series is tentatiYely correlated with the fossiliferous Trias on the west 

shore of Cook Inlet on account of lithologic and structural resemblances and because of its 

association with the Lower Jurassic. 

The Triassic rocks of Cold Bay, Bear Cove, and Bear Bay, whose age has been definitely 

determined by fossils, consist of thin-bedded chert, limestone, and shale of varied colors. The 

chert and limestone are usually dark (black, green, or clark red) when fresh, but weather to 

lighter shades. No measurement of the thickness has been made, but it is estimated to be at 

least 2,000 feet in the exposures seen by us, in which the base was always cut off by intruded 

igneous rocks. 

These rocks are always closely folded and are frequently crumpled. They are usually 

cut by numerous dikes of diverse character and composition, varying from granite to andesite 
542 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

and basalt. The more acid dikes are apparently characteristic of the Triassic rocks and were 

intruded soon after the folding which must have closely followed Triassic time, for they do 

not cut the younger rocks. * * * 

The Triassic fauna of the region as now known is almost limited to the single species 

Pseudomonotis subcircularis Gabb, which is very abundant in certain layers of shale and limestone at Bear Cove and Cold Bay. Specimens from the latter locality were described and 

figured by Fischer as Monotis salinaria, which it resembles in its general features, but a cornparison of a large series of specimens from Alaska with a similar series of Gabb's California 

species shows that they are not separable. The species belongs to the group of Pseudomonotis 

ochotica, which is characteristic of the Upper Triassic of Siberia and the boreal regions generally. 

In California Pseudomonotis subcircularis is confined to the Swearinger slates, which form 

the uppermost Triassic formation of that region. Similar beds with the same fossil occur in 

Y ancouver and Queen Charlotte islands and on the mainland of British Columbia, and they 

cover considerable areas in the Copper River region of Alaska. 

At Bear Bay the much-folded Triassic limestone yielded imperfect specimens of a Halobia, 

and at Cold Bay a few imperfect ammonites not generically determined were obtained in beds 

overlying the Pseudomonotis layers, but possibly still within the Triassic. 

0 7-8. SOUTHEASTERN ALASKA. 

The first determination of Triassic in Alaska was made by Paul Fischer 330 

m 1872. Rocks of this age in the Mount St. Elias Range are also described by 

C. W. Hayes. 416 Referring to the "Vancouver series;" Brooks 101 g says: 

It is to be expected that this Triassic series will be found in the adjacent parts of Alaska, 

but up to the present time it has not been positively identified. It has been shown that certain 

metamorphic terranes carry Permian fossils, and it is quite possible that the Triassic beds may 

be infolded with these, as is the case with the Carboniferous of Queen Charlotte Islands, ·This 

view is borne out by some obscure fossils (probably Mesozoic) which have recently been found 

by Prindle near Fort ·wrangell. While reconnoitering the southern part of the Alexander 

Archipelago a succession of conglomerates, black shales, and slates was encountered and called 

the Gravina series, from the name of the island where they occur. These rocks are closely 

infolded with the Vallcnar series (Devonian), but tho two formations are probably separated 

by an unconformity. So little was learned of the distribution and structural relations of this 

horizon that tho wisdom of giving it a distinct name now seems open to question. The Gravina 

was correlated with Dawson's Queen Charlotte group (Cretaceous), but on reviewing the evidence its identity with tho Vancouver series (Triassic) seems equally probable. In 1904 vVright 

found a conglomerate and slate series on Admiralty Island which yielded Lower Cretaceous 

or Jurassic forms. 

In the same insular region there are largo areas of massive, basic igneous rocks, chiefly of 

effusive origin, which were grouped together under the name Kasaan greenstone and were provisionally assigned to the Mesozoic. On the Queen Charlotte Islands, to the south, rocks of a 

similar character occur in both the Triassic and in the Cretaceous, and the Kasaan effusives may 

belong to either period, but in the report citNl were provisionally placed in the Cretaceous and 

correlated with the rocks of the Queen Charlotte group. 

0 9. DEASE AND LIARD RIVERS, BRITISH COLUMBIA. 

Certain strata, "consisting of regularly bedded, dark, calcareous, flaggy argillites, alternating with gray flaggy and massive limestones" were observed "at the 

second great bend" of the Dease in 1887 by Dawson,258 a who notes their lithologic 

resemblance to the "Triassic of the west coast" but, not having found fossils, regards 

the evidence as "too imperfect for a reference of the beds." 
TRIASSIC. 543 

On the Liard McConnell 560 a obtained more definite information: 

Beds holding Triassic fossils occur along the Liard in the eastern foothills of the Rocky 

Mountains. They consist of dark shales, usually rather coarsely laminated, and passing into 

calcareous shales interstratified vvith sandstones and shaly and massive limestones. The latter 

arc moderately crystalline, arc dark in color, and are usually very impure. They arc harder 

than the shales and at Hell Gate narrow the valley into a canyon. Tho beds undulate, usually 

in easy folds, along the valley, and are exposed in numerous disconnected sections, but it was 

found impossible in hurrying through to make even an approximate estimate of their thickness. 

Triassic fossils were found at the Rapids of the Drowned, at Hell Gate, and at one intermediate 

point. It is probable, however, that a considerable portion of the barren shales east and west 

of these points are also of Triassic age. All the fossils collected have been examined by Mr. 

Whiteaves, and the following list of species, nine of which are described by him in volume 1, 

part 2, of the "Contributions to Canadian paleontology," is furnished by him: 

Spiriferina borealis. 

Terebratula liardensis. 

Monotis ovalis. 

llalobia (Daonella) lommelli \Yissman. 

Halobia occidentalis. 

Nautilus liardensis. 

Popanoceras mcconnelli. 

Trachyceras canadense. 

Trigonodus? productus. 

Margarita triassica. 

Triassic beds were not detected along the eastern edge of the Liard Cretaceous basin. They 

are also absent from the valley of the Mackenzie, as the Cretaceous rocks were found there in a 

number of places resting directly on the Devonian. 

P 7. WRANGELL MOUNTAINS, ALASKA. 

The Triassic of the Wrangell Mountains and adjacent regions comprises the 

Chitistone limestone, which was formerly referred to the Carboniferous, and the 

overlying black shales and limestones, up to the unconformity with the Kennicott 

formation (Upper Jurassic or Lower Cretaceous). The facts have been discussed 

in successive Alaskan reports, of which the latest is one by Moffit and Maddren/01 

who quote from earlier investigators and say: 

In 1907 fossils were collected from the Chitistone limestone at a number of localities between 

Kotsina River and Chitistone River, and they definitely determine its age as Triassic. Part 

of these fossils were found in place, but a majority were collected from the talus debris below 

cliffs of the limestone, yet there was no place where it seemed possible that the limestone fragments containing the fossils could have come from any other source than the cliffs above them, 

and no hesitation is felt in accepting their evidence for the age of the Chitistonc. The fossils 

were determined by T. vV. Stanton, who describes them as follows: 

"Several different localities are represented in the collections, but the fossils, with one 

exception, are all said to be from the Chitistonc limestone and closely associated formations. 

The collection is small and somewhat fragmentary,· but it has proved sufficient to show quite 

conclusively that the beds in question are of Triassic age. The ammonites, especially, are all 

characteristic Triassic types, and the few brachiopods obtained arc also Mesozoic. There is no 

indication of Paleozoic fossils in any part of the section represented." 

Schrader and Spencer, 709 who included the Chitistone limestone in the Carboniferous, said: 

The Chitistone formation is composed of very massive limestones, without any important 

intercalations of shale. When weather .old, it has a white or gray color, which makes it prominent 

in contrast with the greenstone upon which it lies, but when broken it is found to have a blue 
544 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

color, which is indicative of considerable carbonaceous material in its composition. In texture 

it is fine grained throughout. * * * 

Studies of the Carboniferous and Triassic strata of the Wrangell district have not been sufficiently detailed to afford evidence as to where the line between these two formations should be 

drawn. Above the massive basal series of limestones there is a series of thin-bedded limestones 

with shaly partings, which is apparently in perfect conformity with the underlying beds and 

which passes by gradation into the black shales above. These black shales contain the fossils 

by means of which the Triassic age of the formation has been determined. The provisional 

and arbitrary line between the two formations has been placed at the top of the massive limestone series. The thickness of the Chitistone formation, as thus defined, is somewhat variable. 

Its maximum development is probably in the region of Nizina River, where it reaches a thickness 

of approximately 2,000 feet. In the Kotsina and Strelna region its thickness is somewhat less, 

but it can not be made out that there is any progressive thinning toward the west. * * * 

The rocks which have been included in the Triassic series comprise all the strata that lie 

above the Chitistone limestone and below the unconformable Kennicott formation, of JuraCretaceous age. In the lower part, and resting conformably upon the Chitistone limestone, is 

a series of thin-bedded limestones, in strata from a few inches to a foot or more in thickness, 

supported [separated?] by thin partings of black shale. The thickness of this member is approximately 1,000 feet, and the limestone, so far as observed, did not contain fossil remains. Above 

the thin-bedded limestones, and sharply defined from them, are black shales containing occasional bands of impure limestone, locally affording fossils, from which the age of the formation 

has been determined. The thickness of the upper member of the Triassic is very great, possibly 

more than 3,000 feet, but no opportunity was offered for its direct measurement, since its occurrence as the surface formation beneath strata lying unconformably upon it, together with the 

attitude which it has assumed as the result of folding and faulting, renders its relations complicated and obscure. A few thin flows of greenstone, similar to that of the Nikolai series, were 

observed here and there interbedded with the black shales of the Triassic. The Triassic series 

may be easily recognized from its general homogeneous nature and the fine-grained character 

of its black carbonaceous shales. 

Locally the thin-bedded limestones are very intricately folded and contorted. 

P 8. STEWART RIVER SECTION, YUKON PROVINCE. 

Keele 474 a assigns to the Triassic certain rocks in the northern Rocky Mountain 

section, where the map of North America shows undifferentiated metamorphic 

Paleoz?ic. He says: 

The crystalline limestone, provisionally classed as Upper Paleozoic, rests unconformably 

on the crystalline schists, while it is apparently overlain by Triassic rocks. No fossils were 

found and the contact with the Devonian rocks to the north was not seen. A similar rock 

mass occurs on the Macmillan River which was classed as Carboniferous from evidence of some 

fossil remains found in that locality. 

This occurrence also overlies crystalline schists unconformably and is followed by what 

are probably Mesozoic rocks. 

The rocks grouped as Triassic are almost altogether of sedimentary origin. Thin bedding 

and diversity in the color and composition of the beds are characteristic features. They have 

been greatly folded and crumpled in some localities, while in other places they are horizontal. 

Cleavage planes have been developed and certain of the beds have undergone slight alteration 

during the processes of mountain building. 

The rocks which underlie the eastern extremity of the area marked Triassic on the accompanying map sheet are chiefly made up of sandstones, grits, red slates, limestone, and some 

volcanics, while toward the western end shaly argillites with thin quartzite and limestone beds 

prevail. Beds similar to the latter also occur in the section to the west. 
TRIASSIC. 545 

The evidence gathered from the study of a few fossils found in the area, while not conclusive, is in favor of referring at least a portion of the series to the Triassic. 

A group of rocks similar in many respects to the above occurs along the Macmillan R·iver 

40 or 50 miles to the south, but the black chert beds found in that area are absent in the Stewart 

River series. 

R 3. CAPE THOMPSON, NORTHWESTERN ALASKA. 

In describing the section of Carboniferous and Triassic strata which lie m a 

syncline south of Point Hope and Cape Thompson, Kindle sooa says: 

The higher beds of the Cape Thompson section are brought in contact with the beds already 

described [Carboniferous] in the midst of a zone of rather local but complicated folding and 

possibly of faulting, which renders it impossible to give even an approximate estimate of their 

thickness as seen from the top of the southeastern portion of the Cape Thompson cliffs; but 

between the second and the fourth deep ravines separating the high ridges just southeast of 

the cape along the coast the exposures are continuous for 2 miles, exposing a section of northerly 

dipping beds in which the dip decreases from 35° to 0 near the middle of the synclinal. We 

find in the series of cliffs which face the sea to the southeast of the second ravine below Cape 

Thompson a section which passes without structural complications from the fossiliferous 

Carboniferous limestones to the top of the highest beds exposed in this vicinity. This section 

is as follows: 

Section 2 miles southeast of Cape Thompson. 

Feet. 

(e) Soft black shales..................................................................... 500+ 

(d) Dark cherts and thin-bedded cherty limestones with some greenish bands. . . . . . . . . . . . . . . 25 

(c) Argillites with bands of black, green, and dull red cherts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 600 

(b) Light-gray limestone, weathering buff, with some bands of dark chert; apparently barren 

of fossils .......................................................................... 2. OOO+ 

(a) Light-gray limestone similar to the above, but with less chert and containing numerous 

fossils in which corals are conspicuous....... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3, 000+ 

In the upper part of the lowest division of this thick limestone se-ries, a of the section, 

fossils are fairly abundant. * * * Only a few were collected, however. These are given 

in the following list by Dr. Girty, whose remarks on the general faunal relations of these faunas 

have already been given. 

Lot 15 A.-Zaphrentis sp., Spirijer aff. striatus, Composita? sp. 

The close physical resemblance of the second division (b) of the limestone series to the 

lower leaves little doubt that it is also of Carboniferous age. It may represent the Upper 

Carboniferous, which has not been recognized anywhere on the northwestern coast of Alaska, 

though known on the Yukon and in southeastern Alaska. 

The lithologic change at the top of this limestone series is abrupt. The beds included in 

c and d are essentially similar, and represent the same formation, although there is less of the 

calcareous element in the lower beds. Fossils were found, however, only in the upper beds 

marked d in the section. They occur in great abundance in certain strata in this portion 

of the section. About 7 feet near the top are composed almost exclusively of shells which 

have been largely altered to chert. Dr. T. W. Stanton has furnished the following report 

on the fossils secured from this horizon: 

"Lot 15d. Mouth of creek 2 miles southeast of Cape Thompson. 

"This collection consists of limestone fragments with numerous specimens of aviculoid 

shells referable to Pseudomonotis subcircularis (Gabb) or to a closely related species. No 

other recognizable species are associated with it. This species occurs in an Upper Triassic 

horizon in California, and it has been accepted as sufficient evidence for the Triassic age of 

rocks containing it at Cold Bay and in the Copper River region of Alaska. In my opinion, 

the horizon which yielded it at Cape Thompson is also Upper Triassic. 

"Among the collections obtained by Mr. Collier in the Cape Lisburne region some years 

ago there are several small lots consisting mainly of a form that seems to be identical with 

48011°--12----35 
546 INDEX TO THE STRATIGRAPHY OF NORTH .A.MERICA. 

Pseudomonotis subcircularis and probably comes from about the same horizon as this Cape 

Thompson locality. These fossils were at that time identified as Aviculopecten and referred 

to the Carboniferous, chiefly because of the stratigraphic relations they were supposed to hold 

with well-characterized Carboniferous faunas. If Mr. Kindle's interpretation of the structure 

is correct the horizon in .question at Cape Thompson is above all the Carboniferous faunas 

and offers no stratigraphic difficulties in its reference to the Triassic." 

(See Chapter VIII, pp. 396-399.) 

R 27. NORTHEAST COAST OF GREENLAND. 

The facts which are known regarding the Jurassic rocks of eastern Greenland 

have been summarized by Skeat. 742 According to the observations of the Danish 

expedition of 1891-92, at Neill's Cliffs there is a succession of strata which comprises the following: 

1. At the base a green sandstone, not found north of Cape Stewart. 

2. Next a gray sandy clay ~hale, with many fossil plants. This is seen in the valley, 160 

to 180 feet above sea level, and also crops out immediately below on the shore. 

3. The next part of the slope is completely obscured by weathered fragments, which 

conceal the underlying beds. 

4. Above is a very impure reddish-colored limestone, very rich in fossils. The limestone 

varies very considerably in different parts. It may be sandy and unfossiliferous; or full of 

small pebbles sometimes rolled and sometimes angular, so that the rock is now a conglomerate 

and now a breccia; lastly, it may be a typical shell breccia, crammed with fossils of Jurassic 

age. These variations occur near each other and pass over into each other. The bed is 7 feet 

thick and occurs at a height of 186 feet above sea level. 

5. Above this is a sandy shale without fossils. 

6. Next comes a sheet of basalt 10 feet thick. 

7. This is overlain at the end of the valley by a yellow sandstone, 6 feet thick, with a 

few carbonized plant remains, which forms the uppermost deposit at Cape Stewart. 

Continuing along Hurry's Inlet, Neill's Cliffs get higher and higher, owing partly to the 

position of the beds, but probably also to the fact that other beds crop out both above and 

below those already mentioned. 

The members of the expedition landed toward the- northern end of the inlet, approximately 

southwest of the Fame Islands. Here the lowest bed exposed was a flaggy sandstone with, 

once more, the fossiliferous limestone above. The limestone in this exposure is pure toward 

the middle but conglomeratic or brecciated upward and downward. Not far but yet not 

immediately above this limestone is the basalt again, which here appears at a height of 1,300 

feet, with alternating layers of sandstone and dolerite above. Several beds which are seen here 

belong to a higher horizon than those of Cape Stewart, and farther inland yet newer deposits 

occur. The fossils obtained were mainly lamellibranchs and brachiopods; many were new 

species, but certain typical Middle European forms, namely, Avicula munsteri cf. Goldf., Limea 

dupli9ata Sow., Ostrea sandalina cf. Goldf., were interspersed among them, the former in large 

number. These species are of Middle Jurassic or Callovian age, and the fauna is altogether 

characteristically Callovian; moreover it has close affinities with the Middle European type. 

Lundgren, who examined the fossils collected on this occasion, identifies the Cape Stewart 

beds with the Callovian of Kuhn Island; the lowest shales containing plant remains were 

proved by Hartz w be of Rhretic or Rhretic-Lias age. 

The Swedish expedition of 1899 under N athorst reports Rhretic plant remains 

and a yellow sandstone with numerous Ostreas and Belemnites. The map which 

is published with Nathorst's work represents horizons of the Keuper, Rhretic, 

and Jurassic. 
TRIASSIC. 547 

The Danish expeditions of 1898 and 1900 reported numerous fossils including 

many ammonites and others of Jurassic or Cretaceous age. Fossils comprising 

plant remains of Rhretic or Liassic age, and marine fossils of various divisions of 

the European Jurassic are cited by Skeat. The principal occurrences ofthe Jurassic 

are assigned to the Callovian. A clearly older fauna occurs at Mount Nathorst, 

which is probably of upper Bajocian or lower Bathonian age. 

In Jameson's Land there is evidence of the white Jura or Upper Jurassic, 

approximately of upper Kimeridge or Portland age. Of the Triassic of this region 

Nathorst 609b writes: 

It is supposed that Rhretic layers may possibly be present at Falsche Bay, mentioned 

above, from which locality Payer brought home a piece of sandstone with Rhynchonella fissicostata Suess. * * * 

One of the most important geological results of the Danish expedition was the announcement that rocks belonging to the Rhretic and Jurassic system occur on the west side of Hurry 

Inlet from Cape S~wart northward. They are the same. rocks that Jameson referred to the 

Carboniferous. 

At Cape Stewart the lowest layers are Rhretic, consisting of a gray, somewhat sandy clay 

slate that in certain beds is quito rich in fossil plants. It is supposed to be underlain by a 

greenish sandstone and is thought to be at least 45 to 55 meters thick. The fossil plants are 

described by N. Hartz, who has called attention to their Rhretic age. Several of these are to be 

found in the coal-bearing beds of Skone, Sweden. As characteristic may be mentioned Cladophlebis roesserti Presl. sp. var. grcenlamdica, Equisetum munsteri Sternb. sp., Pterophyllum sub~­

quale Hartz, Podozamites lanceolatus Lindl. sp., and schenlcii Hr., Ozelcanowslcia rigida Hr. and 

setacea Hr., Stachyotaxus septentrionalis Agardh sp., besides others. 

(See also R-S 27, Chapter XIII, pp. 577-578.) 

T 11, 13-16. ARCTIC ARCHIPELAGO. 

Low 550i summarizes the available information regarding the Mesozoic of the 

Arctic Archipelago: 

The discovery of the Sverdrup group of islands has greatly extended our knowledge of the 

Mesozoic rocks of the Arctic basin. The Franklin search parties discovered rocks of this age 

on the northern shores of the Parry Islands; at Point Wilkie, in Prince Patrick Island; Rendezvous Hill, near the northwestern extreme of Bathurst Island; and at Exmouth Island and 

places in the vicinity, near the northwest part of North Devon. The explorations from the 

Fram now show that these are but the southern edge of a wide basin of rocks which form the 

islands of King Oscar, Ellef, and Amund Ringes, while they constitute the lowlands of Axel 

Heiberg and the western shores of Ellesmere along both sides of Eureka Sound. There they 

consist largely of sandstones with shales, schists and limestones. 

For a general discussion of the faunal relations of the Arctic Triassic, especially with reference to that of Siberia and its affinities with North American faunas, 

see papers by Mojsisovics. 603•

604 

U 18-21. GRINNELL LAND AND NORTHERN GREENLAND. 

The Cape Rawson beds of Grinnell Land have been classed as "Huronian or 

Lower Cambrian," and lately as probably Triassic, at least in part. Dawson, 257 

commenting on the original description by Feild en and De Rance, 326a says: 

After noting the Laurentian system as the fundamental one for the region [Ellesmere Land, 

Grinnell Land, and the neighboring coast of north Greenland] and as forming Cape Isabella. 
548 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

(latitude 76° 20') and the entire east coast of Ellesmere Land, they give the name Cape Rawson 

beds to an important overlying series which occupies the coast of Grinnell Land from Scoresby 

Bay to Cape Cresswell, in latitude 82° 40' north. These rocks are described as being thrown 

into a series of sharp folds, with a general west-southwest strike, the beds being often vertical 

and frequently cleaved. The rocks consist of jet-black slates, with impure limestones traversed 

by veins of quartz and chert, and of a vast series of quartzites and grits. They are compared 

to the gold-bearing series of Nova Scotia, and doubtfully referred to the Huronian system. 

Their lithologic character, however, as compared with the Canadian rocks, and in view of the 

occurrence elsewhere to the north of a great Lower Cambrian series, appears to me to favor 

their inclusion in that series rather than in the Huronian. 

Schei 707a discovered extensive exposures of "quartz sandstones with subordinate schists and limestones" on both shores of Heureka Sound (between Grinnell 

or Ellesmere Land and Heiberg Land) which he describes as Mesozoic. They contained ammonites and lamellibranchs, among others possibly Daonella lammelli. 
CHAPTER XIII. 

JURASSIC. 

Color, greenish blue (horizontal ruling). 

Symbol, 9a. 

Distributidn: Central America, Mexico, California, Oregon, Alberta, and parts of Alaska. 

Content: Jurassic limestone and shale of Nevada; Mariposa slate, Sierra Nevada; Franciscan 

formation, Coast Range, California; Jurassic of .Mexico; Chinitna shale and Tuxedni sandstone ("Enochkin formation"), also Naknek formation, of Alaska Peninsula. The Jurassic 

of Humboldt Range, Nevada, and the marine Sundance formation of the Rocky Mountains 

are mapped with the Triassic, as "Triassic and Jurassic" (9), the areas being too small 

to distinguish the system separately. 

Jurassic areas. 

Page. 

D 16 .......................... Guatemala (not mapped) .. .. . . . . . . . . . . . . .. . .. . . . . . . . .. .. .. .. .. . .. . . . .. .. . . 549 

E 14 ........................... Oaxaca.. . . .. .. . .. . .. . .. .. . . . . .. . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . 549 

E-F14 ........................ Puebla and Vera Cruz..................................................... 551 

F 14 .. __ ...... _ .. _. _ .......... Sierra de Catorce, San Luis Potosi, Mexico.................................. 551 

F 17-18 ....................... Cuba..................................................................... 552 

G 13-14 ............ _ ........... Sierra de Mazapil, Zacatecas and Coahuila.................................. 552 

H 13 .......................... Texas .................................. -..... --.-........................ 554 

I-Kl0-11 ............ _ ........ Coast Range, California.................................................... 554 

J 10 ..... _ .................... Sierra Nevada, California. .. .. .. .. . .. . .. .. . .. . . .. . .. .. .. . . . .. .. .. .. .. .. . .. . 555 

J 11 .. __ ...................... Humboldt Range, western Nevada......................................... 556 

J 12. _____ . ___ . _ .............. Southern Utah and plateau district, Colorado (mapped as Triassic and Jurassic). 556 

K 10. _. ___ ..... _. ___ ........... Upper Sacramento Valley, northern California, and southern Oregon.......... 561 

K 12 ........................... Southwestern vVyoming (mapped as Triassic and Jurassic)................... 565 

K 12-13 ........................ Northwestern Colorado (mapped as Triassic and Jurassic).................... 566 

K-L 13 ........................ Wyoming and South Dakota (mapped as Triassic and Jurassic)................ 567 

L 11. ......................... Eastern Oregon (mapped as Triassic and Jurassic).. . .. .. . .. . .. .. .. . .. .. .. . .. . 571 

L 12 .......................... Montana and Wyoming (mapped as Triassic and Jurassic)...................... 571 

L-M 10 .. __ ... __ . _ .......... Olympic Peninsula .. . .. .. . .. . .. .. . .. . .. . .. .. .. . .. . . . . . . . . .. .. .. .. .. .. .. .. 572 

M 10 ........................... Washington and British Col~bia (not mapped)............................. 573 

M 11. .......................... Southwestern Alberta..................................................... 574 

M-0 9-10 ..................... Western British Columbia (not mapped).................................... 574 

0 4-5 .......................... Alaska Peninsula..... . .. . . . . . . . . . . .. . ... .. .. . . . . . . .. .. .. . . .. . . . . . . . . . . . . 574 

0 8 .............. _. _ ........... Atlin Lake, British Columbia (mapped as Triassic and Jurassic).......... . . . . 576 

P 8 ........................... Lewes River, Yukon Province (not mapped)................................ 576 

R 3 ........................... North western Alaska. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 77 

R-S 27 ......................... Northeast coast of Greenland.............................................. 577 

D 16. GUATEMALA. 

Dollfuss and Mont-Serratt 286 cited the identification of Jurassie fossils reported 

to have been collected on the shores of Lake Isabel in eastern Guatemala and 

contained in the collections of the Collegio Tridentino, but Sapper does not mention 

any such occurrence, and the rocks described by Dollfuss and Mont-Serratt under 

the Jurassic appear to be Cretaceous. 

E 14. OAXACA. 

At Tlaxiaco, in Oaxaca, according to Felix and Lenk/27c Jurassic strata constitute the greater part of the Cerro Titania. At the base are thin-bedded clay slates 

549 
\ 

FIGURE 15.-Sketch map showing the distribution of Jurassic rocks that are separately represented on the geologic 

map of North America and the key to references in the text. 

550 
JURASSIC. 551 

of bright-red and greenish tints which suggest the European Triassic as well as some 

Jurassic clays. As they are unfossiliferous their age is not determinable. Above 

them lies a great thickness of calcareous and in part marly deposits, which are 

without doubt of Jurassic age. They include dense light-gray limestone which 

appears in general to be unfossiliferous with the exception of the remains of a small 

Exogyra that could not be more exactly determined. Above this lower sequence 

outcrop certain marly strata which contain numerous thin lenses of brown iron ore 

and which like the preceding are very poor in fossils. They have yielded an impression of an Apiocrinus stem and an ammonite, Stephanoceras paucicostatus. This 

species belongs to a group of the ammonites whose youngest representatives do not 

range above the Oxfordien, and the marls therefore belong either to that horizon 

of the white Jura of Europe or are to be assigned to the brown Jura of Europe. 

The crest of the Cerro Titania is formed by gray marly limestone which is 

highly fossiliferous. The character of the contained fauna is that of the white Jura 

and probably represents the European Sequanien. 

E-F 14. PUEBLA AND VERA CRUZ. 

According to Felix and Lenk 327 b the late Mesozoic is represented in the states 

of Puebla and Vera Cruz by fossiliferous strata containing fauna related to that of 

the Lias (Lower Jurassic) of Europe. Most of the specimens found belong to 

Arietites jamesdanae Barcena, and are as a rule but poorly preserved. The rock is 

a black to yellow clay slate which contains no lime but which on the other hand 

includes plates of mica and is somewhat metamorphosed, so that it resembles 

Paleozoic rocks rather than ,Mesozoic. 

Felix and Lenk give a list of nine localities at which fossils have been found. 

The Lower Jurassic strata are overlain by black calcareous slates interbedded with 

black limestones that contain Perisphinctes and are assigned to the Upper Jurassic. 

These in turn are followed by limestones of the Lower Cretaceous. According to a 

section through Barranca de la Calera and Barranca del ·Rio Potrero Seco, both in 

Vera Cruz, by Bose, the strata are conformable from Lower Jurassic to Lower 

Cretaceous. 

F 14. SIERRA DE CATORCE, SAN LUIS POTOSI. 

Feli~ and Lenk 3278 state that the Jurassic is widely distributed in Mexico but 

does not appear anywhere to form areas of great extent. The occurrences are 

small in area and widely separated, and they are also notably different in faunas. 

In the Sierra de Catorce, in San Luis Potosi, certain unfossiliferous gray slates 

are succeeded by late Mesozoic strata which have been separated by Castillo and 

Aguilera 132 into two divisions, and the lower of these has been again divided into 

two terranes-an upper one, the Cieneguita, and a lower, the Alamitos. 

The Alamitos formation consists of fine sandstone and marly· or clayey slate 

interbedded with each other. It contains numerous fossils, a list of which is given 

in both of the works cited. The Cieneguita formation also consists of marly slates 

and sandstones which contain more or less carbonate of lime. A number of fossils 

have been found. The upper of the two major divisions contains in the upper 

part ash-gray compact limestones which are more or less siliceous. The lower part 

is shaly and the whole is very poor in fossils. The Alamitos and Cieneguita forma-
552 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

tions are regarded as representatives of the Russian Volgien (Jurassic) and in a 

general way the Alamitos corresponds with the lower Volgien or Tithon, but the 

Kimmeridge may be represented in it. The Cieneguita, which is distinguished 

by an abundance of Aucella, represents the upper Volgien or Neocomien (Lower 

Cretaceous). 

F 17-18. CUBA. 

T. W. Vaughan contributes the following notes on the Jurassic of Cuba: 

Strata of Jurassic age have been reported from Cuba and the Isle of Pines since the time 

of Humboldt. Recently Dr. Carlos de la Torre has collected Jurassic ammonites, referred by 

him to the genus Idoceras, in the vicinity of Vifiales, and has published excellent photographic 

illustrations.a Dr. T. W. Stanton agrees with De la Torre in considering these ammonites of 

Jurassic age. Jurassic limestone forms the axial portion of the Sierra Organos, in the Province 

of Pinar del Rio, and is the oldest geologic formation revealed in a cross section of the island 

taken along a line passing through Vifiales, in the vicinity of which are excellent exposures. 

The limestone is hard and blue, and, though not distinctly crystalline, it is intersected by 

small white veins of calcite. 

Overlying the Jurassic limestone, south of Vifiales along the road to Pinar del Rio, are 

reddish argillaceous schists, which form two parallel ridges. These schists were evidently 

derived from the metamorphism of a shale series that contained a few beds of sandstone and 

some layers of limestone. 

G 13-14. SIERRA DE MAZAPIL, ZACATECAS AND COAHUILA. 

Burckhardt 109 has classified and described the Jurassic and Cretaceous of the 

Sierra de Mazapil district, in the "Mesa Central" of Mexico, as follows: 

Jurassic and Cretaceous series ofthe Sierra deMazapil and Santa Rosa. 

Formation. Lithologic character Principal fossils. Age. and thickness. 

Upper Creta- Shales and limeShales with Inoceramus. stones; 150-200 Inoceramus sp. Turonien. ceous. meters. r) T.Unootono" 

Middle Creta- Cherty with gastro- Gray limestones Scaphites sp., Schloenbachia Middle Creta- lime- po~s. with black cherts; acutocarinata (Shum.) Marcou, ceous. t s (a) Limestones 400-500 meters. open ammonites (Hamites). ceo us. s one · with open 

ammonites. 

o:i ' Parahoplites cfr. milletianus Delimiting ;:I Clear yellow marls Pict. (non D'Orb.), Parahop- 0 and gray lime- lites cfr. aschiltaensis, Anthula beds be- <1l Parahoplites beds. tween the " ce stones; several cfr. treffryanus, Anthula (non ...., Aptien and ~ meters. Karsten), Parahoplites, many Q undetermined species. the Gault. 

Lower Creta- Grayish limestones with Lower Creta- ceo us. large cherts; bluish 400-500 meters. Holcodiscus sp. 

' limestones. ceous. 

Yellowish marls Astieria aff. psllostoma N. and 

with nodules of U., A. cfr. atherstoni Sharpe, 

Holcostephanus beds. 

oxide of iron and Hoplites aff. michaelis Uhl., 

gray Valanginien. and yellow- H. cfr. hystricoides Uhl., H. 

ish limestones; dr. neocomiensis D'Orb., H. 

several meters. cfr. thurmanni P. and C. 

- a An. Acad. cien. Habana, Rev. cien., vol. 47, July, 1910, pl. facing p. 22. 
JURASSIC. 553 

Jarassic and Cretaceous series of the Sierra de Mazapil and Santa Rosa-Continued. 

Portland. 

Kimeridge. 

Formation. 

\Vhitish marly limestones with chert. 

Grayish 

phosphatic 

limestones. 

(c) Cuculltea 

horizon. 

(b) Fossiliferous 

limestones 

with Perisphinctes. 

(a) Limestones 

with bivalves. 

I 

Lithologic character 1 

and thickness. 

10 meters. 

Fossiliferous and 

highly c h e r t y 

limestones, grayish; black limestones; 5-6 me- ters. 

Principal fossils. 

Perisphinctes dr. koeneni Steuer, 

P. permulticostatus Steuer, 

Hop lites cfr. calistoides Behr, 

II. many species of the group 

of H. calisto D'Orb. 

Perisphinctes santarosanus nob., 

P. victoria nob., burkarti nob., 

Hoplites cfr. rjasanensis Lah., 

Hoplites cfr. wallichi Gray, 

Neumayria subrasilis nob. 

Age. 

Base of the 

B erriasen?, 

Upper 

Portland. 

Upper and 

L o w e r Portland. 

--------------------1-----------------l---------------------------l------------

Reddish phosphatic 

limestones. 

Shales with Waagenia. 

Haploceras fia.lar beds. 

1-2 meters. 

B r own i s h shaly 

clays, highly ferruginous; 10-30 

meters. 

Black c o m p a c t 

limestones; l me- ter. 

Phylloceras apenninicum Can., 

Eurynoticeras zitteli nob., 

Perisphinctes cfr. danubiensis 

Schlosser, P. nikitini Mich., 

Virgatites mexicanus nob., 

Aspidoceras cyclotum (Opp.) 

Steuer, A. fallax nob., A. phosphoriticum nob., A. cajense 

nob., A. zacatecanum nob. 

Waagenia cfr. harpephora Font, 

W. aff. beckeri Neum., W. cfr. 

knopi Neum., W. cfr. harpephora Neum. 

Oppelia cfr. trachynota Font. 

(Oppel), 0. aff. strombecki 

Oppel, Haploceras fialar Oppel, H. many species, Craspedites mazapilensis nob. 

Base of the 

Portland. 

Summit of the 

Kimeridge. 

Upper Kimeridge. 

l--------------------1-----------------l--------------------------l------------

Aucella horizon. 

Idoceras beds. 

Limestones with Neri- nea. 

Brownish s h a I y 

limestones, 

slightly phosphatic. 

Shaly clays and 

marls with lenses 

and nodules of 

compact b lac k 

lime8tone; 15-30 

meters. 

At the summit a stratum of black 

and reddish limestone with Trigonia. The principal mass is grayish massive limestone with interbedded gray 

marls containing 

bivalvesand beds 

of coral; of great 

thickness. 

Aucella, many species of the 

groups of A. pallasi Keys and 

A. bronni Rouill. 

Neumayria profulgens nob., Oppelia aff. nereus Font., 0. flexuosacostata Qust., Macrocephalites epigonus nob., Simo- ceras cfr. doublieri D'Orb., 

Aspidoceras con temporaneum 

Favre, A. bispinosum Qust., 

A. cfr. acanthicum Oppel, Ido- ceras laxevolutum Font, I. 

balderum Oppel, Aulacostephanus zacatecanus nob., etc. 

Nerinea various species, corals 

with the marine bivalves 

(Pholadomya, Trigonia, Astarte, Opis), gastropods (Harpagodes), and brachiopods 

(Terebratula). At the top of 

the limestone Simoceras cfr. 

doublieri Lorio! (D'Orb.). 

Upper Kimeridge. 

Delimiting 

beds between the 

lower and 

upper Kimeridge. 

Upper Jurassic (probably Sequanien). 
554 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Burckhardt's description 110 is as follows: 

The Jurassic and Cretaceous series of the Sierra de Mazapil is composed of four great natural 

subdivisions. At the base one may observe heavy-bedded limestones which attain great thickness and are the limestones with Nerinea. These are the Upper Jurassic limestones which form 

the center of the anticlines of the two ranges mid which, since each chain is composed of a single 

anticline, occupy generally the highest portions, the peaks and crests of the sierras. 

The flanks of the two chains are also formed by heavy masses of limestone of great thickness 

which locally resemble the limestones with Nerinea, but which, even so, may be readily distinguished by their petrographic character. These limestones are generally well stratified and 

contain a great deal of chert in beds and lenses which alternate with them. The fossil fauna 

of these limestones indicates that they correspond to different divisions of the Lower and 

Middle Cretaceous. 

Between the two masses of limestones which have been described there occurs a zone of 

less compact strata composed of clays, marls, and slates, with intercalations of limestone. 

* * * The colors of these rocks are generally dark and contrast strikingly with the clear colors 

of the limestone masses between which they occur. The beds are very fossiliferous and have 

furnished a large number of well-preserved specimens, which demonstrate that they belong to 

the Kimeridge and Portland. · 

The latest stratigraphic division which may be observed in the region, in the valleys and 

at the foot of the sierras, covers the Cretaceous limestones that have been cited. It consists 

of shales, in part sandy and in part argillaceous, of which the lower portion, the shales with 

Inoceramus, belongs to the Upper Cretaceous (Lower Turonian). 

H 13. TEXAS. 

In southwestern Texas, just north of latitude 31°, near the line of the Southern 

Pacific Railroad, Malone Mountain rises from the desert plains north of the Quitman 

Mountains and is formed in large part of Jurassic strata. The fauna was dicscovered 

and described by Cragin, 177 and the general geology of the region has been stated by 

Stanton in a brief chapter in Cragin's report, which contains also a detailed section. 

Stanton says: 

The most complete section that I observed, in which the thicknesses were estimated with 

some care, extends across the mountain from a point on the east side about one-half mile south 

of Malone station. The eastern face of the mountain shows an apparent thickness of about 

1,200 feet of blue and gray limestones, with a few intercalated beds and bands of conglomerate 

and sandstone, the beds all dipping strongly westward with increasing dips until they become 

vertical on the crest. On the west slope there is a succession of limestones, conglomerates, and 

gypsum beds, nearly vertical, and not well exposed, and farther down these are apparently 

repeated with a westerly dip, overlain by conglomerates, limestones, etc., fairly well exposed and 

not much disturbed in the lower ridges to the west. The gypsum beds and the limestones immediately associated with them appear to be the oldest rocks exposed. 

I-K 10-11. COAST RANGE, CALIFORNIA. 

The Franciscan formation of the Coast Range of California is regarded by 

Lawson as of Cretaceous age but is generally placed in the Jurassic. The basis for 

Lawson's view is the relation of the Franciscan formation to the Montara granite, 

which is one of stratigraphic unconformity. Lawson correlates the granite tentatively .with the late Jurassic granite of the SierraN evada and infers accordingly that 

the sedimentary Franciscan formation, which rests unconformabl) upon the granite, 
JURASSIC. 555 

is probably Cretaceous. (See table of the geologic formations of the Coast Range 

of California in the vicinity of the bay of San Francisco, p. 816, Chapter XVII.) 

For a description of the Franciscan, we may refer to Lawson's original account.524 

According to that statement, it consists of the following petrographic elements:a 

(1) A basal formation of conglomerates, coarse grits, sandstones, shaly sandstones, shales, 

and argillaceous limestones, exposed in the vicinity of San Pedro Point. These rocks require 

n:o detailed discussion. 

(2) The San Francisco sandstone, the dominant sedimentary formation of the series, consisting of a moderately fine grained sandstone, fairly uniform in character over large areas, with 

subordinate beds of shale and conglomerate. The sandstone is uniform, not only in its lateral 

extension, but vertically for great thicknesses. In the older writings it has commonly been 

referred to as the San Francisco sandstone, and the term is here adopted from that usage. It is 

interbedded with the formations 3-5 which are named below. 

(3) Foraminiferal limestones. 

(4) Radiolarian cherts. 

(5) Volcanic rocks, including basaltic lavas, diabases, pyroclastic accumulations, etc. 

Besides these there are intrusive rocks of a corresponding character, some of which are probably 

connected with these extravasations, and also intrusive peridotites and pyroxenites, now serpentinized. 

In addition, there are certain metamorphic schists, which are the products of the local 

alteration of the sedimentary or volcanic formations of the series and, according to the writer's 

interpretation of them, do not constitute a separate formation. There are also a few patches 

of a peculiar veinlike rock associated with the San Francisco sandstone, but of rather uncertain 

genetic relations. In his field notes the writer has been in the habit of referring to this as 

silica-carbonate sinter, and it will be further described under that designation. 

J 10. SIERRA NEVADA, CALIFORNIA. 

Along the western base of the Sierra Nevada in California the Mariposa slate 

forms three narrow bands. The strata are prevailingly clay slates, which are 

sandy and contain pebbles of rocks from the Calaveras formation (Carboniferous). 

Tuffs from contemporaneous porphyrite eruptions also occur in them. The fossils 

of these beds, such as Aucella and Perisphinctes, indicate a late Jurassic age. 

In the folio describing the Sonora quadrangle Turner and Ransome 815 give a 

detailed account of the characteristics of the rocks in the three bands in which the 

formation outcrops, especially as observed at localities within that quadrangle. 

Lindgren 538 describes a more northern occurrence of the Mariposa in the Colfax 

quadrangle, where it succeeds the Sailor Canyon formation (Triassic). He states 

that it consists of black shales or slates, usually not very fissile, alternating with 

dark-gray sandstones of coarser or finer grain, and a great number of conglomerate beds. The rocks are tuffaceous and contain much iron. The conglomerate 

beds, though rarely very thick, are very abundant and contain pebbles of chert, 

quartz, slate, and limestone evidently derived from the older Calaveras formation. 

The Mariposa was clearly deposited in a gulf or shallow bay, the conglomerates 

indicating immediate proximity of the shore line. 

The fauna contained in the Mariposa formation has been discussed by Hyatt 468a 

and by James Perrin Smith. 763 

a For a detailed description of the subdivisions see the work cited. 
556 INDEX 'fO THE STRATIGRAPHY OF NORTH AMERICA. 

J 11. HUMBOLDT RANGE, WESTERN NEVADA. 

The Jurassic of western Nevada was briefly described by Hague 390 and King. 505b 

The latter says: 

In the Nevada province the Jurassic consists of a limestone between 1,500 and 2,000 feet 

thick and overlying slates probably about 4,000 feet thick. 

Louderback547 refers to the JuraBsic as composed chiefly of gray to greenishgray slate with subordinate limestone, which in Muttleberry Canyon carries Arietites 

sp. nov., referred by Smith 764b to the Lower Jurassic or Lias of Europe. 

J 12. SOUTHERN UTAH AND PLATEAU DISTRICT, COLORADO. 

Dutton 300 describes the Jurassic of the High Plateaus of Utah in part as follows: 

The Jurassic series consists of two members, the lower being a massive sandstone of great 

thickness, the upper a series of calcareous and gypsiferous shales from 200 to 400 feet thick. 

Underneath the sandstone is a small group of shaly beds, which are presumed to be of Jurassic 

age, but no determinable fossils have been taken from them. * * * Comparing the JuraTrias section of the Uintas with that of the High Plateaus and Kaibabs, we find a concordance 

in the several members. 

Uinta sec- Kanab sec- tion. tion. 

--------------------------------------·---

Calcareous shales, limestone and gypsiferous shales [a] .................................. . 

Massive, cross-bedded white sandstone ................................................. . 

Feet. 

1,000 

1,100 

Feet. 

500 

1,400 

--------------------------------------l-----1----

Thin calcareous shale ................................................................. . 100 50 

Vermilion Cliff series ................................................................... , 1,100 1,500 

--------------------------------1----1----

Upper Shinarump shales and conglomerate ............................................. . 1,000 750 

Belted shales ........................................................................ . 400 400 

Lower Shinarump shales ............ -...... -·------·--···----------·--·--····----··· --I 300 500 

aT. W. Stanton makes the following comment on the manuscript: "The marine Jurassic fauna ranges through the 

lower 250 feet of the uppermost member of this section." 

The lithological characters of the Jurassic white sandstone render it a very conspicuous 

formation. Through a thickness of more than 1,000 feet, sometimes of nearly 2,000 feet, it is 

one solid stratum, without a single heterogeneous layer or shaly parting. * * * The color 

of the rock is almost always gray, verging toward white. Occasionally it is a very pale cream 

color, and again pale red. The red becomes more common as we recede from the old shore line 

toward the east. But of all the features of this rock the most striking is the cross-bedding. 

It is hard to find a single rock face which is not lined off with rich tracery produced by the 

action of weathering upon cross lamination. The massive cliff fronts are etched from summit 

to base with a filagree as intricate and delicate as frost work. The same phenomenon is seen 
JURASSIC. 557 

in the Vermilion Cliff sandstones below, often so rich and complex that it excites constant 

admi.ration. Dr. Newberry speaks of it with enthusiasm as presented in the Triassic sandstones 

of New :Mexico. But it is far less wonderful than the cross-bedding which the Jurassic presents 

at every exposure. * * * The Jurassic sandstone was deposited over an area which can 

not fall much short of 35,000 square miles, and the average thickness exceeds 1,000 feet. The 

imagination is utterly baffled in the endeavor to conceive how a mass so vast and at the same 

time so homogeneous and intricately cross-bedded throughout its entire extent could have 

been accumulated. 

The cross stratification of the Jurassic sandstones of southern Utah has been 

discussed by Huntington 466 as an evidence of wind action. Dutton continues: 

Overlying the white sandstone is a series of beds which may be called shales with some 

reservation, and here we find for the first time an abundance of distinctive fossils. They are 

clearly of Jurassic genera and species and enable us to correlate the horizon with confidence. 

They belong to a well-marked formation, which is represented not only throughout the greater 

part of the plateau province, but also in Colorado, Wyoming, and northern New Mexico. From 

many large areas, indeed, it has been denuded, but throughout Utah it is never wanting from 

those exposures where its presence could be looked for. 

The constancy of lithological character which is so conspicuous in older Mesozoic members 

does not prevail in this one, for it is highly variable not only in the mass but also in the constitution of the beds. In some exposures it is more than 1,000 feet thick; in others, it is less 

than 200. Where its volume is greatest it is more arenaceous, and where the volume is less 

the beds are shaly, marly, and calcareous. Usually several seams of limestone occur, and in 

these the fossils are found, often abundantly. One notable feature is the small amount of 

cement in the arenaceous layers, which are, therefore, very poorly consolidated, and the rock 

weathers and wastes away with extreme facility. Gypsum and selenite occur abundantly in 

these beds and especially noticeable is the latter mineral, which is seen sparkling and glittering 

in the sunlight in the badlands to which the decay of the strata gives rise. 

A section of the Triassic and overlying Jurassic observed by Walcott in the 

Kanab region is quoted by Cross in an article on the red beds. (See I-K 12-13, 

Chapter XII, p. 514.) Stanton a comments on Cross's suggestion that the La Plata 

sandstone of southwestern Colorado may be correlated with the \Vhite Cliff sandstone of Utah and says that in that case the La Plata is well down in the .Jurassic, 

because the -White Cliff sandstone underlies marine Jurassic beds that are of the 

same age as the Twin Creek, Ellis, and Sundance formations. 

In western Colorado at the east end of the Uinta uplift Gale 353 b has found 

marine Jurassic fossils in a white sandstone which he correlates with the \Vhite 

Cliff and the La Plata. 

In southwestern Colorado the Jurassic is represented by the La Plata sandstone and probably by the McElmo formation, although the age of the latter is 

not definitely known to be Jurassic; it may be Lower Cretaceous. The La Plata 

and McElmo are equivalent to the Gunnison formation farther north. Cross 189 

gives the following classification and descriptions: 

a Comment on manu,;cript. 
558 INDEX TO THE STRATIGRAPHY OF NORTH .. AMERICA .. 

Correlation of formations .. 

San Juan folios, U. S. Geological Survey. Peale. Holmes . I Powell. 

.. 

Mancos. 

Cretaceous. --~-

Dakota. Dakota or Upper Dakota. Upper Dakota. Henry's Fork. 

Lower Dakota. 

McElmo. J,ower Dakota. Flaming Gorge. 

Jurassic. Gunnison. Jurassic. 

La Plata. \Vhite Cliff. 

Triassic. Triassic. Vermilion Cliff. 

Triassic. Dolores. 

-·-

! 

I Permian? 

Permian, Permo-Carbon- Shinarump group (all as- Cutler. iferous, or Upper Car- signed to Triassic). 

boniferous. 

Carboniferous. 

Pen_nsylva- Hermosa. Middle Upper Carboni£- I Aubrey. 

n1an. erous. I 

I 

All geologists who have examined the Mesozoic section of western Colorado have been 

impressed with the strong lithologic resemblance exhibited by several hundred feet of strata 

occurring immediately below the Dakota to the fresh-water Jurassic beds found along the 

eastern base of the Front Range and characterized by the wonderful dinosaurian fauna exploited 

by Marsh and others.. With one exception to be considered below this lithologic similarity and 

the corresponding stratigraphic position have been considered sufficient to warrant the assignment of the western slope beds to the Jurassic. 

The first to give a formation name to those strata was Eldridge, who called them the Gunnison formation. In the San Juan region it was found better to divide the Gunnison into the 

McElmo and La Plata formations, the former to include the alternating sandstones and variously 

colored marls and shales of the upper part of the section and the latter the heavy sandstones 

of the lower portion. 

Before the McElmo beds were so named they had been studied in the Telluride quadrangle, 

at the head of San Miguel and Dolores Valley, and had been traced for some distance down 

each stream. · 

They are continuously exposed down the canyon of the former to the Dolores River and 

have a wide distribution in the Uncompahgre Plateau, about the La Sal Mountains and in the 

lower Dolores and the Grand River valleys. This is clearly stated by Peale in the report for 

1875. * * * 

The McElmo beds in characteristic development were seen by us in Dry Valley and on the 

eastern flanks of the La Sal Mountains, in Dolores Valley, and in many places on Uncompahgre 

Plateau, as far north as Unaweep Canyon. To the north from that locality Peale refers to the 

formation as maintaining the same general character. No representative of the marine Jurassic 

reported by Powell and others from Utah was observed by us. 

Rumors of large bones, presumably in the McElmo beds, have come to my attention several times in recent years, but never with the exact locality named, and no trace of such 

remains has been found in the San Juan region. 
JURASSIC. 559 

The McElmo beds of Dry Valley are fossiliferous, locally at least, as proved by Newberry, 

who found saurian bones in place at about 500 feet below the Dakota in the southeastern 

branch of Dry Valley, named by him Canon Pintado or Painted Canyon. From Newberry's 

description of the locality and our own observations of the Canon Pintado from the mesa to 

the west, as well as on the route traversed through Dry Valley, it is certain that the saurian 

bones came from the McElmo. Newberry expressed no positive opinion as to the age of the 

bone-bearing horizon, but called it "Jurassic ( ~)" in his "General section of the valley of the 

Colorado." 

The saurian bones found by Newberry were described by Cope as the type of Dystroph;:eus 

vi;:emal;:e, and were said in positive but quite unwarrantable terms to have come from the Triassic, with no suggestion of the provisional assignment to the Jurassic by Newberry. Cope states 

that Newberry excavated the bones of Dystroph::eus "from the red and green rocks usually 

referred to the Trias, hence from the same formation which yielded the Typothorax already 

described." The Typothorax in question was found in New Mexico with belodont crocodile 

and other forms, almost demonstrating that its horizon is the fossiliferous zone of the Dolores 

Triassic formation, the place of which in the Grand River section is nearly or quite 1,000 feet 

below the McElmo beds, as will be shown in a later section. Cope adds emphasis to his error 

as follows: "More than usual interest attaches to this fossil. It is the first one found in the 

Triassic beds of the Rocky Mountain region. * * * The rock is described by Prof. Newberry as the same as that which I have identified in New Mexico as the Trias and is of the usual 

red color." In harmony with the occurrence of Dystroph;:eus vi;:emal;:e in the McElmo beds it 

has recently been pointed out by F. von Huene that its affinities are Jurassic rather than 

Triassic. 

That the McElmo beds contain vertebrate fauna of the "Atlantasaurus beds" of Marsh 

has been demonstrated by Riggs, who discovered many dinosaurian remains in that formation 

near the junction of the Grand and Gunnison rivers at the northeastern base of the Uncompahgre Plateau. While this vertebrate fauna has not as yet been described, it is referred to by 

Riggs as clearly the same which characterizes the Jurassic beds of Wyoming and the eastern 

base of the Front Range in Colorado. It is said that "representatives of a single genus (Morosaurus) have been observed to range through the entire series," meaning a section some 500 or 

600 feet in thickness below the Dakota. * * * 

The term La Plata formation has been applied in the San Juan folios and other publications to the lower part of what Eldridge described as the Gunnison formation. 

The La Plata consists of two massive sandstone members with an intermediate member 

of more thinly bedded sandstones and a variable amount of bluish fresh-water limestone.. The 

sandstones are commonly not indurated, as in the Elk Mountains; instead they are rather 

friable and crumbling, although of homogeneous texture. Cross-bedding is a marked feature, 

and not infrequently a massive ledge as much as 100 feet in thickness has no prominent division planes. Of the two sandstone members the lower is commonly the thicker and much 

more massive than the upper. The latter is in fact occasionally thin bedded and shaly and 

may be inconspicuous. 1 

The calcareous member is very variable in character. On the San Miguel River, in the 

Telluride quadrangle, it is in some places a pure massive blue-gray limestone in several beds 

and with almost no shale. Usually dark calcareous and bituminous shales and thin-bedded 

sandstones, with more or less of massive limestone, occur between the two main sandstones 

and sometimes reach a thickness of nearly 100 feet. 

The total thickness of the La Plata formation varies, in the area we have examined, from 

about 100 feet in the Ouray and Telluride quadrangles to 500 or more in the La Plata Mountains, and it is known that to the west all members increase still further in thickness. 

The sandstones are almost wholly quartzose, and their normal color adjacent to the San 

Juan Mountains is white or gray; but yellow, orange, or red tints have been observed in that 

region. The cement is often calcite. 

• 
560 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

In the Red Beds paper were given the observations of Spencer, who traced the La Plata 

sandstones to Paradox and Sinbad valleys, west of the Dolores, and of Gane, who followed 

them down the San Juan Valley to the Colorado Canyon. Both noted the prevalence of orange 

or pink color in the lower country. 

On the strength of these observations and a study of literature it was concluded that "the 

La Plata formation is seemingly equivalent to the White Cliff sandstone. Its local assumption 

of red color has led to confusion with the Vermilion Cliff in certain districts and a reference to 

the Trias." This correlation is considered to be amply substantiated by the recent observations. * * * 

The continuity of the La Plata sandstone from the San Juan Mountain flanks down the 

Dolores and San Miguel valleys, around the La Sal Mountains to Grand River valley, may be 

said to be perfectly plain and incontestable. In this distance the most notable change in the 

formation is its increased thickness. The massive texture and even grain of many strata, 

cross-bedding, variation in color, and other marked features are but emphasized by the greater 

volume. The intermediate strata are most variable in character, yet everywhere the two great 

massive sandstone members are separated by beds distinguishable through their thin bedding, 

darker color, and richness in calcareous cement or development of limestone. 

From the district covered by our reconnaissance the ledges of gray, pink, or orange La 

Plata sandstone can be seen stretching to the west and south into the belt traversed by Green 

and Colorado rivers, where Powell has described the White Cliff sandstone. This great unit in 

the plateau country section was never described accurately nor in detail for any given locality, 

but there seems to be no ground for questioning the assertion of Powell that this formation is 

continuous with persistent characters from northeastern Utah to the great esplanade bordered 

by the White Cliffs in southern Utah; facing the Grand Canyon. The characters of the White 

Cliff repeatedly emphasized are its massiveness, "oblique lamination" or "false stratification," 

and its white, golden, orange, or light-red colors, which are so brilliant in the desert air. 

The upper boundary of the White Cliff is the basal marine limestone of the Flaming Gorge 

group of Powell. The lower boundary is less clearly defined in the statements of Powell and 

others, but, with recognition of the stratigraphic break soon to be mentioned and the marked 

color line apparently everywhere present at the summit of the Triassic sandstones, it may be 

hoped that no great difficulties in drawing the base of the White Cliff will be experienced when 

the attempt is seriously made. 

The far-reaching unconformity below the fresh-water Jurassic beds of central Colorado, by 

which they overlap all older Mesozoic and Paleozoic beds and in many places rest on the pre-· 

Cambrian granites and schists, is well illustrated by the Hayden maps. This overlap is particularly well exhibited in the southern Elk Mountains and some of its details are shown in the 

Anthracite-Crested Butte folio. 

The fact that no Paleozoic formations are present in the Uncompahgre Plateau was recognized by Peale and expressed on the Hayden map. I£, however, the greater part of Peale's 

"Triassic" in that area be now referred to the La Plata Jurassic, as has been done in the preceding discussion, the question arises as to whether evidence of erosional unconformity between the 

La Plata and the underlying Dolores Triassic exists in that area or not. Our observations on 

th1s point were quite limited but tend to show that such a break does occur. It is certain that 

in the vicinity of the Unaweep Canyon the dark-red Triassic strata are much thinner than in 

the Dolores Valley to the west, and this decreased thickness appears to be principally due to 

erosion of the massive red sandstone forming the upper part of the Triassic. 

On the north side of West Creek, which is the western stream flowing out of Unaweep 

Canyon, Messrs. Emmons and Kay found the La Plata to rest on granite near the shore line of 

the Permian ( ~) beds, which will be discussed in another part of this article. At the head of 

West Side Creek a few miles south of the Unaweep the pink La Plata sandstone rests on thinbedded sandstones and shales belonging to the lower part of the Dolores formation, as shown 

by the presence of the fossiliferous "Saurian conglomerate." Near the head of Atkinson Creek 

on the western side of Uncompahgre Plateau, the La Plata seems to rest on gneiss. * * * 
JURASSIC. 561 

These facts and the evident variation in thickness of the massive Dolores sandstone, which 

we noticed at many places, seem to speak for a relation of the La Plata and Dolores very similar 

to that existing on the western and southwestern slopes of the San Juan Mountains. But much 

more careful observation is needed in the Uncompahgre Plateau to determine to what extent 

the absence or variable thickness of the Triassic beds is due to pre-La Plata erosion. Personally, I believe that the Triassic beds were originally deposited over the Uncompahgre Plateau 

and indeed all of western Colorado, and that they were in some places entirely removed by the 

erosion under discussion, but this view is not yet supported by enough evidence to warrant a 

positive assertion. 

K 10. UPPER SACRAMENTO VALLEY, NORTHERN CALIFORNIA, AND SOUTHERN OREGON. 

In northern California several minor but interesting occurrences of the Jurassic 

have been described by Diller. 279 The Modin and Potem formations occur in the 

Redding quadrangle. The Modin consists of a basal conglomerate, followed by a 

succession of tuffaceous beds, which are overlain by gray shaly sandstones and shales 

with small limestone lentils. It rests unconformably upon the Triassic, and the 

tuffaceous beds include fragments of the underlying limestone and other older formations. The Potem formation consists of shale and thin-bedded sandstone with small 

limestone lentils, and it also includes some tuffaceous conglomerate. The thicknesses are stated by Diller at 3,000 feet for the Modin formation and probably several 

thousand feet for the Potem. 

In the Taylorsville district, just north of the fortieth parallel, the Jurassic is 

represented by seven distinct formations. According to Diller 280aThe Trail formation is the oldest; then follow the Hardgrave sandstone, Thompson limestone, Mormon sandstone, Bicknell sandstone, Hinchman tuff, and Foreman formation in regular 

succession. With the exception of the last their surface distribution is limited to a comparatively small area about Mount Jura, and * * * it may be stated here that the whole set of 

beds have been overturned and that the Hardgrave sandstone apparently lies on top. * * * 

The Trail formation includes a mass of strata composed largely of slaty shales with some 

interbedded sandstones and conglomerates. * * * The shales are often purplish or red but 

perhaps more frequently gray, with pencil structure locally developed, and contain in places 

numerous cherty nodules of carbonate of lime. Well-marked slaty structure is not uncommon. 

The sandstones are generally fine, often somewhat slaty, are thin-bedded, and vary from gray to 

almost black. The conglomerates of slate and sandstone pebbles, sometimes 3 inches in diameter, generally contain much volcanic material. Approaching the contact with the granodiorite 

in many places the fine sediments become darker and more compact, with conchoidal fracture, 

and pass into regular hornfels. * * * Some of the beds of tuff are well·defined, ranging from 

10 to 50 feet or more in thickness, and occasionally coarse. Tuffaceous conglomerates are most 

abundant on the side toward the Swearinger slate but extend throughout the formation, and a 

strip of 50 feet of slaty conglomerate occurs in the volcanics which bound the sediments on the 

northeast. * * * The thickness of the Trail formation was measured on the prominent spur 

next north of Hornfels Point descending into the sharp bend of Hosselkus Creek and found to be 

about 2,900 feet. 

Undeterminable traces of plants and some small bivalves, possibly Estheria, 

but not any fossils which would determine its horizon, have been found in the Trail 

formation. It appears to be unconformable to the Swearinger slate, and thus to 

occupy essentially the same relative position as the Modin formation, at the base of 

the Jurassic sediments. 

48011°--12----36 
562 INDEX 'fO THE STRATIGRAPHY OF NORTH AMERICA. 

The Hardgrave sandstone is red or gray in color. It varies from fine shaly sandstone to conglomerate and is almost wholly of a tuffaceous character. The most common color is red, ranging from brick-red to dull brown, but much of it is gray, and the two colors are intermingled 

irregularly in the same bed. The bedding is generally well marked, but in a few localities the 

massive outcrops show little trace of stratification. Where the sediments are fine the sandstone 

passes into shale, which occasionally shows a decided slaty cleavage and breaks up into long, 

slender, pencil-shaped fragments. Generally the sandstone is so fine as not to appear granular 

and breaks with a splintery fracture. * * * When the coarser forms of Hardgrave sandstone are broken the fracture generally passes around the grains inst8ad of through them, 

allowing them to stand in relief upon the fracture surface and make it rough. Rarely it is 

hard and flinty, much fractured, and veined. * * * Carbonate of lime is the principal 

cement, but in the red and weathered forms oxide of iron plays an important part. * * * 

Coarse gray sandstone and fine conglomerate are much less abundant than the finer forms. 

* * * [The material] is mainly volcanic sand, made up of crystal fragments of plagioclase 

feldspar with many lapilli, usually more or less vesicular, and often filled with minute lathshaped crystals of feldspar, which are for the most part so altered that their polysynthetic 

twinning, if present, can not be seen. Many of the feldspar fragments are plagioclase, but a 

somewhat smaller number appear to be orthoclase and possibly some quartz. One of the 

striking features of this sandstone, apparent only on microscopic examination, is the paucity of 

quartz. * * * ·The maximum thickness of Hardgrave sandstone as measured half a mile 

north of Donnerwirth's may be 850 feet but is possibly much less. 

According to Hyatt 280b the Hardgrave sandstone contains many fossils having 

affinities with the lowest or infra Lias, and some which might even have occurred in 

the uppermost Triassic or Rhretic. Hyatt further says: 

On the other hand, some forms have very close relations to the same genera as they appear 

in the Mormon sandstone, or Oolite, of the same locality. Pinna, Gervillia, Ctenostreon, Entolium, Trigonia, and Cidaris show an assemblage of upper Lias types. The species of Entolium 

and Ctenostreon are closely related to those of the oolite above, and one species of Trigonia 

resembles the young of a species from the Oolite of western Europe. The most conclusive evidence, however, is furnished by the single well-preserved specimen of Glyphea * * * and the 

Goniomya, allied to G. v-scripta Agassiz. 

After giving a list of 28 species and discussing the significance of Glyphrea, 

Hyatt says: 

Such forms as these and the evidently close alliance and probable continuity of the fauna 

through migration with that of the Mormon sandstone suggest tl~at the Hardgrave sandstone 

should be classed as upper Lias in spite of the large number of forms which are represented by 

species occurring also in the lower and middle Lias in Europe. 

Diller continues the description of the Jurassic strata as follows: 

The Thompson limestone is gray and somewhat shaly, and on its weathered surface in 

places are round, oblong, or irregular patches of darker, more or less granular calcite, which at 

once suggests fossils, though their specific determination is a matter of difficulty. Where shaly 

it is generally red, highly argillaceous, and locally full of long, slender gastropods, which weather 

out and leave the porous argillaceous skeleton of the limestone full of "screw holes." * * * 

The relation of the Thompson limestone to the meta-andesite that bounds it upon the west may 

be clearly seen on the northern slope of Mount Jura, near the end of the lime road, where the red 

calcareous beds, full of slender gastropods, come into direct contact with the altered andesite. 

The fossils lie parallel to the surface of the volcanic rock, practically against it, without showing 

any alteration due to the presence of the igneous rock. This relation evidently indicates that 

the limestone was deposited upon the meta-andesite and is of later age. It has already been 
JURASSIC. 563 

shown that the same meta-andesite is younger than the Hardgrave sandstone. The general dip 

of the Thompson limestone is to the southwest beneath the meta-andesite by which it is bounded 

in that direction, and both pass beneath the Hardgrave sandstone. All have been overturned 

together. 

Hyatt's comment on the age of the Thompson limestone, which he called the 

Opis bed, is as follows: 

11r. Diller's close and repeated investigations of the stratigraphy have placed the Opis bed 

below the Mormon sandstone in the chronologie series, and my studies, although they led me to 

incline to the opinion that the fauna was younger, have not succeeded in bringing to light any 

evidence that can be said to contradict his conclusions. The presence of a large form of Nerinea 

with the columella, showing the typical ridges of the normal forms of this group, indicates that 

this limestone is not older than the inferior Oolite, and if, as seems to be the case, it is older than 

the Mormon sandstone, it will probably be proved to be a member of the inferior Oolite. 

A large species of Opis is as abundant in some places as the Nerinea, and this genus, which is 

recorded in Europe as beginning in the Trias, is usually small throughout the lower and middle 

Jura. The only European species approximating to that of this limestone is the Opis paradoxa, 

as figured by Buvignier, which occurs in the Corallian of the upper Jura. A species of Terebratula, apparently identical with the large characteristic species of the Mormon sandstone, also 

occurs abundantly in this bed. There are also a number of small gastropods and other fossils 

requiring further investigation. 

The Mormon sandstone consists prevailingly of sandstone, passing on the one hand into 

conglomerate and on the other into more shaly beds. The most common and characteristic 

member is a gray compact sandstone so fine that to the naked eye it does not appear granular. 

Its color becomes brown on weathering and the rock frequently contains casts of a small Rhynchonella. Among the grains of which it is composed there are many of quartz and of feldspar, 

some of which is clear plagioclase with distil)ct twinning lamellre. A few of pale-green augite, 

but most of them are of indefinite elouded material in which here and there small lath-shaped 

crystals of feldspar may be seen, indicating their derivation from igneous rocks. There is a 

small amount of carbonate of lime present, and it becomes somewhat more abundant in the 

coarser forms. The conglomerate of the Mormon sandstone is generally greenish but sometimes reddish .. Its pebbles are in a few places mainly quartzite, but at most localities they are 

chiefly of meta-andesite with a few of metarhyolite, and range from one-eighth of an inch to 18 

inches in diameter. Several pebbles of limestone were observed, but none contained fossils. 

In the conglomerate are masses of fine shaly red sandstone with decided pencil structure parallel 

to its stratification. This same sort of material occurs also to a limited extent entirely independent of the conglomerate, and in such cases it is thin bedded and finely stratified. * * * At a 

narrow point in the wavy belt across the western slope of Mount Jura the following section was 

observed: Adjoining the eastern side of the Thompson limestone is 45 feet of massive gray 

sandstone with a rich fauna. This is succeeded farther up the slope by 30 feet of conglomerate 

and finally by about 20 feet of finely stratified red shaly sandstone, the "Inoceramus bed" 

mentioned by Prof. Hyatt. The total thickness of this belt a short distance farther south 

increases to about 225 feet, and the conglomerate becomes more prominent but farther along 

again diminishes and is scarcely noticeable near the south end . 

. The maximum thickness of the Mormon sandstone noted by Diller is 550 feet. 

Diller quotes Hyatt at length in regard to the fossils and age of the Mormon sandstone, and Hyatt concludes that the horizon is that of the upper part of the inferior 

Oolite of Europe. 

The Bicknell sandstone is composed chiefly of reel and gray sandstone associated with 

some dark shales and tuffaceous beds. The dark brownish-red sandstone is largely feldspathic 

and contains much red oxide of iron, with more or less carbonate of lime. It somewhat resembles 
564 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

the red Hardgrave sandstone but is darker colored, and though much of its material may be 

derived from igneous rock, its particles are not characterized by the presence of numerous 

small crystals of feldspar as in the Hardgrave sandstone. Sandstones, mottled gray and red, 

form transitions to the gray sandstone which is the most abundant rock of the formation. 

Much of it is fine dark bluish gray, very compact and hard, breaking with a conchoidal fracture, 

and flecked here and there by small particles of pyrite. It looks so much like hornfels that 

one is surprised to find it locally full of large shells. Associated with this form is more or less 

black shale, some beds of which weather white and look like fine volcanic dust. A thin section, 

however, shows no characteristic volcanic material, but instead extremely fine sediment with a 

multitude of minute microscopic crystals of rutile which have developed in the sediment since 

it was laid down. 

A coarser variety of the sandstone is light gray or greenish and passes into a rock which is 

full of small white crystals of feldspar with a few scales of gray mica embedded in a dark groundmass, and the general aspect is decidedly igneous. The fact that it contains distinct fossils 

shows that it is fragmental, and it locally becomes coarse, so that its real character is more 

evident. In thin section under a microscope the fine fossiliferous rock is clearly fragmental, 

and much of the sediment was evidently derived from the erosion of volcanic rocks. 

The maximum thickness of the Bicknell sandstone is probably over 1,000 feet, 

but its thickness decreases both north and south of Mount Jura, so as to average 

less than 500 feet. Hyatt finds some elements of its fauna comparable with the 

youngest faunas of the Jurassic in Europe but concludes from the evidence of the 

ammonites that it may be really synchronous with the Callovian. 

The Hinchman sandstone is composed essentially of coarse sandstone with shaly parts and 

some conglomerate which is generally fine and derived chiefly if not wholly from andesitic rocks. 

Much of it is decidedly tuffaceous. The most common form is greenish gray and contains 

darker-colored shaly patches but is not conspicuously fragmental. Examined microscopically 

it is found to be made up largely of fragments of feldspar, augite crystals, and varying proportions of andesitic rock, fragments of which are clearly microporphyritic. The feldspar is 

generally much altered. Some of the augite is fresh, but most of it is altered to chlorite, giving 

a greenish color to the rock. It is never coarse like volcanic agglomerate, though it is sometimes 

made up largely of ejected volcanic material, some of which is clearly pumiceous. The grains 

are rarely well rounded by attrition, though it is evident that they have been transported and 

loosely aggregated on the sea floor, affording corners and cavities where corals, belemnites, and 

a number of other marine forms flourished. Remains of these animals are not confined to one 

horizon but are scattered throughout the formation. The conglomerate locally becomes coarse 

and composed of pebbles, some of which are well rounded; others are angular. The largest 

pebbles are rarely a foot in diameter. One of the most abundant types is a reddish, decidedly 

microporphyritic andesite. Others less common are dark and macroporphyritic, with either 

feldspar or hornblende phenocrysts. Limestone pebbles or nodules occur sporadically, but 

none could be found with fossils. 

In thickness the Hinchman sandstone appears to range from 50 feet to more 

than 500 feet. The most characteristic fossils are corals of the genus Stylina, 

related to species of the Corallian of the Upper Jurassic of Europe. 

The Foreman formation is a succession of shale, sandstone, and conglomerate in which the 

sediment is for the most part derived from rocks which are not clearly volcanic. The shales are 

often slaty and locally have "pencil structure" and range in color from dark carbonaceous with 

traces of leaves through gray, which predominates, to shades and tints of red and yellow. A 

remarkable feature of the shales locally is their pencil structure, which is particularly well 

developed in the summit of Evans Peak. The beds of red and gray sandy shales making the 

summit of the peak break up into small columns, often of lead-pencil size but generally 

smaller. * * * 
JURASSIC. 565 

Almost as abundant as the shales are the sandstones, most of which are very fine and 

decidedly shaly. They are reddish brown and gray, sometimes mottled with darker spots, 

chiefly carbonate of lime. * * * Occasionally the gray sandstone is more siliceous and 

contains irregular particles which give to the mass the appearance of a fine tuffaceous conglomerate. 

Conglomerate is less abundant than either shale or sandstone and is usually in thin beds 

of small extent scattered throughout the formation. Th0 most characteristic conglomerate 

of this formation is composed almost wholly of small pebbles of cherty quartz, black and gray 

in color, and rarely over half an inch in diameter. Of this there are but few beds ranging from 

5 to 12 feet in thickness. A more abundant form of conglomerate contains locally many shale 

fragments and well-rounded pebbles chiefly of meta-andesites and rhyolites, with a few of 

fossiliferous limestone. The majority of the beds are small and are made up of small pebbles, 

rarely as large as 3!- inches in diameter. Associated with the limestone pebbles in the conglomerate are concretionary nodules of carbonate of lime, which occur also in the shale and 

sandstone. They do not contain fossils and grade into the inclosing rock instead of having a 

sharp contact, as is the case with the limestone pebbles. 

The Foreman formation contains fossil plants, which were studied by Fontaine, 

who placed them in the Mesozoic and considered them as most probably older than 

Cretaceous. An examination of later collections by Knowlton led him to question 

some of Fontaine's determinations, and marine invertebrates in the formation 

suffice to prove that it is Middle Jurassic or later. Stanton is of the opinion that 

it may represent the youngest Jurassic of the region, and this view is confirmed 

by Diller's study of the stratigraphy. 

The Myrtle formation of southwestern Oregon and the Knoxville of northern 

California are regarded by Diller, Stanton, and Knowlton as of the same age, but 

it is a mooted question whether they are wholly Cretaceous or in part Jurassic. 

According to Stanton, the Aucellas (Aucella piochi and A. crassicolis) show that 

the formations are not older than Lower Cretaceous. Accnrding to Knowlton, 

the plants which are associated with the Aucellas at some localities are characteristically Jurassic.a The Myrtle and Knoxville are indicated on the map as Lower 

Cretaceous, largely to distinguish them from the adjacent Franciscan areas, which 

are colored as Jurassic, and without any intention of indicating a decision as to 

their Cretaceous or Jurassic age. 

K 12. SOUTHWESTERN WYOMING. 

In the survey of Uinta County, in southwestern Wyoming, Veatch 8390 distinguished the Twin Creek formation and the lower part of the Beckwith formation as 

Jurassic. The Lower Cretaceous appears to be missing or to be represented in the 

upper part of the Beckwith, as the Bear River formation (Upper Cretaceous?) 

immediately succeeds the Beckwith, apparently without unconformity. Veatch 

gives a general description, which is quoted in the table on page 676, Chapter XV. 

From his report we take the following notes: 

The fossiliferous marine Jurassic, to which has been given the local name Twin Creek 

formation, from the excellent exposures on that creek between Sage and Fossil, here consists 

for the most part of dark calcareous shales and thin-bedded shaly limestones, though occasionally showing lighter-colored sandstone layers. These are sharply limited above by the 

thick red beds which mark the base of the Beckwith formation. The thickness of the Twin 

a See quotations under K 10 in Chapter XIV, pp. 617-621. 
566 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Creek beds north of Twin Creek on two earefully measured sections was found to be 3,.500 and 

3,800 feet. * * * 

The Beckwith formation, which directly overlies the Twin Creek, has been so named from 

its occurrence and extemive development on leased State lands now forming part of the Beckwith ranch, situated just east of Beckwith station on the Oregon Short Line. It is here and 

throughout the west side of this area composed of two rather distinct members, a lower red-bed 

member, composed of interbedded sandy clays, sandstones, and conglomerates 2,500 feet thick; 

and an upper member, composed of rather light colored interbedded sandstones and clays. 

The sandstones are commonly rather light yellow and the clays vary from yellow to light pinkish 

red. * * * The upper member has a thickness of 3,000 feet or more. 

In the eastern belt of older rocks these two phases merge; in the area along the west side 

of the great fault just west of Hilliard theRe beds, while having a predominant reddish cast, are 

all light in color. The conglomerates, which near Beckwith are deep red, are here white to 

yellow. These reddish beds are exposed along the whole of the eastern side of the eastern belt 

just east of the Cretaceous exposures, and for the most part form the crest of the pronounced 

anticline which skirts this region on the east. These beds here reach a total thickness of 4,000 

feet. * * * 

This formation is lithologically distinct from the very fossiliferous, dark-colored beds which 

overlie and underlie it, and compared with them is essentially unfossiliferous. Dr. Stanton has 

found marine Jurassic fossils at two points in beds which are regarded as in the lower part of 

the Beckwith formation. At old Bear River City, just west of the great fault line and east of 

the principal conglomerate heel at this point, Dr. Stanton found Belemnites densus M. and H., 

Trigonia g_1;,adrangularis H. and W., Myacites (Pleumrnya) weberensis .Meek ( ?). In the exposures 

north of this point this horizon appears to be distinetly underlain by the characteristic unfossiliferous Beckwith beds, and unless it represents a portion of the Twin Creek which has been 

faulted up-and this is not regarded as probable-it is distinctly in the Beckwith formation. 

This fossil-bearing layer is here about 1,600 feet below the Bear River formation and 2,400 

feet below the Aspen shales. South of Rockport, on Weber River in Utah, Dr. Stanton found a 

specimen of Trigonia g_uadrangularis H. and W. ( ?) about 2,000 feet above the characteristic 

fossiliferous blue thin-bedded limeRtone and shale of the Twin Creek formation and 3,500 

f('\et or more below the lowest observed black shales with fish scales, representing the Aspen 

formation, which here, in the absence of the Bear River, is the base of the known CretaceouR. 

The lower part of the Beckwith formation is thus clearly upper Jurassic, and the remainder 

probably contains time equivalt~nts of the lower Cretaceous and Dakota beds, if these occm· in 

this area. 

Veatch gives a list of fossils from the Twin Creek formation. 

K 12-13. NORTHWESTERN COLORADO. 

In describing the Rangely oil district, Colorado, Gale 353a gives an account of 

the Jurassic strata which constitute the ·white Cliff and Flaming Gorge formations 

of Powell. He says: 

Immediately below the Dakota sandstone is a mass of variegated badland-forming shale 

and clay, including some harder beds of limestone and sandstone, together with a peculiar 

dark cherty, siliceous conglomerate almoRt exactly like that commonly found with the Dakota 

formation above. The shale or marl is prevailingly of greenish and pinkish shades, with some 

beds that weather yellow. The lower 100 to 1.50 feet of this fmmation is composed of darkercolored beds, fine greenish sandstone and calcareous rock. Limestone layers composed largely 

of shells are present near the base, although the general character of the beds seems to indicate 

much limy or marly material throughout. These beds have an approximate thickness of 800 
JURASSIC. 567 

feet, as measured near the base of Blue Mountain. * * * The lower strata of these variegated beds are of marine origin, as shown by the fossils they contain; the upper part, by analogy 

with other and better-known sections, is supposed to be composed largely of fresh-water deposits. 

The variegated and shaly beds are limited at the base by a second group of sandstones 

which, like the Dakota, usually forms a steep rocky ridge. * * * It is usually very white 

and massive and cross-bedded to an extreme degree. 

The variegated beds are of Jurassic age and probably correspond in their upper or supposedly fresh-water part to the Morrison formation east of the Rocky Mountains. They have 

also been variously named "Flaming Gorge," McElmo, and in part Gunnison in the Uinta 

Mountain and western Rocky ~fountain regions. * * * The cross-bedded white sandstone 

is also of Jurassic age, as is shown by fossils obtained from this field. It is with little doubt 

the equivalent to the "White Cliff" sandstone mapped by Powell on the north side of the 

Uinta Mountains, and also seems to be with almost equal certainty equivalent to the La Plata 

sandstone of the southwestern Colorado sections. · 

Gale gives a list of fossils which are regarded as characteristically Jurassic. 

K-L 13. WYOMING AND SOUTH DAKOTA. 

The Jurassic is represented in the Bighorn Mountains and throughout central 

Wyoming by the Sundance formation and possibly by the :JY~o#i~on formation, 

although the latter may prove to be of Cretaceous age. (See Chapter XIV, 

pp. 606-608.) Darton 237e states: 

Typical maririe Jurassic deposits, with an abundant fauna, extend continuously around 

the Bighorn uplift, and they arc so similar to the deposits in the Black Hills that the same 

name is applicable. The thickness averages about 300 feet and the succession comprises a 

sandy series below and a considerable thickness of greenish fossiliferous shales above. At or 

near the base there is usually a hard fossiliferous limestone layer having a thickness of from 

3 to 5 feet, increasing locally to 25 feet. Next above are soft sandy beds often containing large 

numbers of Gryphxa calceola var. nebrascensis. The greenish shales above contain thin layers 

of highly fossiliferous limestones and a few thin sandy layers. 

In another paper 244d Darton describes the Sundance formation as follows: 

The Sundance formation occupies a large area in central Wyoming, but it is absent in the 

Laramie Basin south of Rock River. In Wind River Basin it is mostly covered by Tertiary, 

but it outcrops extensively near Fort Washakie, Lander, and Dallas. lt appears along both 

flanks of Owl Creek Mountains, on the north slope of Rattlesnake Mountains, in southeastern 

Natrona County, in northeastern Carbon County, in the flexures south of Douglas and east and 

northeast of Medicine Bow, and along the east side of Laramie Mountains from Iron Mountain 

station to Crow Creek. Although there is a long time interval between the Sundance and 

Chugwater formations, marked erosional unconformity is rare and in places it is difficult to 

draw the line between them. This is probably because the first sediments of the upper formation were derived from the one below. The upper limits are similarly ill defined. There is no 

discordance in dips of underlying or overlying formations. 

In the Owl Creek Mountain region the Sundance formation consists of about 200 feet of 

soft gray sandstones and green shales with conspicuous hard layers. * * * The local stratigraphy varies somewhat. At the base are sandstones, the middle and upper beds are mainly 

shales, and there is more or less sandstone for about 40 feet at the top. The shales are greenish 

or dark gray and contain limestone in concretions and. thin layers, often highly fossiliferous. 
568 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Section of Sundance formation on Owl Creek 7 miles northwest of Thermopolis, Wyo. 

Feet. 

Green soft sandy shales and. hard greenish fossiliferous sandstone in alternating layers ___ . _ _ _ _ _ _ 70 

Gray sandstone .......... _ ... _____________________________ . _____________________ . _ _ _ _ _ _ _ _ _ _ _ 4 

Green sandy clay .............. ___ . ______ .. _________ ..... _. _________ . ____ . ____ ... ______ .. ___ 20 

Gray limy sandstone ________________________________ . _____ . ______________ . ____ ._____________ 2 

Dark greenish-gray sandy clay, with many belemnites ... _._. ______________ . ____ . _____ _ : _ _ _ _ _ _ 40 

Greenish-gray sandstone, with occasional hard layers .. _. ___ . ______________ . ____ . _. _ _ _ _ _ _ _ _ _ _ _ 30 

Green sandy shale .......... __ ..... ______ .. _____ . ___ ....... _________ ... __ . ____ ..... _____ .. _ _ 20 

Greenish-gray sandstone, thin bedded ... __________________ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 4 

Hard buff impure limestone, breaking into small rectangular blocks __ . ____ . ____ ... ________ . _ _ 2 

Green sandy shale lying on "Red beds" ... ___ . ____ ...... _. ______________ . ____ ... _. ______ . 2 

194 

Along the slope of Wind River Mountains and in the uplifts passing east of Fort Washakie 

and Lander the Sundance formation is about 300 feet thick and consists of greenish-gray shales 

and sandstones, with thin but prominent ledges of impure, highly fossiliferous limestone in 

their upper part. In the northern foothills of the Rattlesnake Mountains, where the thickness 

is about 300 feet, there are gray sandstones at the top, and part of the medial sandy shales are 

of pronounced reddish tint, as in the Black Hills and some other districts in Wyoming. 

Platte Valley to Rock River.-The Sundance formation presents most of its usual features 

along the south side of Casper Mountain, in Muddy Creek valley, and on W agonhound Creek 

and North Platte River south of Douglas. In the extensive exposures in the big bend of the 

river south of Douglas there are 30 feet or more of massive gray sandstone, overlain by 30 feet 

of pale-greenish sandy shale, 5 feet of soft greenish massive sandstone, 40 feet of soft sandstones 

of bright-reddish tint, 15 feet of massive buff sandstone, and about 200 feet of green shale with 

three hard beds of fossiliferous limestone. * * * 

Section of Sundance formation near Alcova, Wyo. 

Green shale ___________________________________________________________________ . __________ _ 

Feet. 

65 

Slab by, hard limestone .. __________________________ ....... _________ .... _ ... __ ...... _____ . _ _ lO 

Green shale._. ___ . _____________________ .. _________ ........ ________ ...... _. __ ..... _. ____ .__ 10 

Limestone ... _____ . ____________________ .. _________ ........ ________ .......... _ ....... ___ .__ 10 

Green shale. _______ . ____________________________________ . ____ ._. ___________ . _________ .____ 75 

Sandstone .... ____________________________ . _________ ........ ________ ........ __ ....... ____ . _ _ 5 

Shale, part pink, part green .. ____________ . __________ ....... _________ .... _. ____ .... _______ . __ 100 

Sandstone, white (on Chugwater red beds) .. ____ . ____ ........ ________ ........ __ ....... __ . _ . _ _ 25 

300 

In the Freezeout Hills and Rock River region the lower beds of the formation are predominantly sandy, while the upper part consists largely of green shales with hard fossiliferous 

layers. In an extensive exposure east of Medicine Bow the strata are as follows: 

Section of Sundance formation in Como Ridge, 6 miles east of Medicine Bow, Wyo. 

Morrison shales. Feet. 

Limestone and shale .... _. ____ . _. _______ ... _ . _. _. __ ........ _. _. _. __ .......... _ ........... _ _ 15 

Massive disintegrated sandstone, in part shaly __ . ____ ........ ________ ......... __ ............ _ lO 

Drab shale with few lumps of brown limestone. _____ ... ___ . ____________________ ...... ____ .__ 30 

Buff shaly sandstone .. ____ . ______________________________ . ____________________ ... _______ . _ _ 5 

Yellow sandy shale with belemnites._. ___ . ______ . __ ........ ________ ........ ___ ..... _ ..... __ 42 

Buff shaly sandstone .... ______ . __________ . ______ . ___ ...... _________ ........ _. _ ..... _ ...... _ 5 

Yellow shale (lying on the Chugwater red beds)_ . ____ ....... _. _______ ......... _ ..... _....... 12 

119 

A section in the eastern side oi the Freezeout Hills near Dyer's ranch, given by W. N. Logan, 

is as follows: 
JURASSIC. 

Section of Sundance formation in Freezeout Hills, Wyo. 

15. Purplish clay with sandy inclusions (has sandy limestone layer near base filled with fossils). 

14. Greenish sandstone, thinly laminated ................................................ . 

Feet. 

40 

2-5 

13. Purplish fossiliferous clay, with many lime nodules filled with fossils..................... 20 

12. White, sandy clay, dinosaur [marine saurian] remains................................... 4 

11. Sandy clay with brown concretions; green sandstone layer near middle .................. . 

10. White sandy limestone in thin layers (fossils) .......................................... . 

9. Sandy red clay ...................................................................... . 

8. White fissile sandstone ............ : .................................................. . 

6 

z 

10 

6 

7. Shale, reddish, changing to purple.................................................... 4 

6. White sandstone, moderately hard.................................................... 1 

2-5. White sandstone separated by two layers of red clay..................................... 1 

1. Red clay of Chugwater formation. 

94+ 

569 

East of Laramie Mountains.-The thin margin of the Sundance formation outcrops continuously along the eastern foothills from North Fork of Horse Creek to the southernmost 

prong of Horse Creek and from the North to the South Fork of Lodgepole Creek. Small 

exposures appear on North and Middle forks of Crow Creek. The rocks are mostly light-buff 

sandstones, but some sandy shales appear. The average thickness is 40 feet. * * * 

Fossils and equivalency.-The formation contains abundant fossils of Middle to Upper 

Jurassic age, and it is believed to be equivalent to the Sundance formation of the Black Hills 

region. The following are the principal fossils: Belemnites densus, GrY]Jh<£a calceola var. 

nebrascensis, Oampectonites [ Oamptonectes?] bellistriatus, Eumicrotis curta, Trigonia elegantissima, 

T. americana, T. conradi, T. montanensis, and Pentacrinus asteriscus. 

In Freezeout Hills the following fossils are reported by W. N. Logan in section given [above]: 

Bed No. 10, Pseudomonotis curta)· bed No. 12, remains of Ichthyosaurus and Plesiosaurus; bed 

No. 13, abundant Belemnites densus throughout, and in the concretions Pinna lcingi, Pinna sp. 

Oardioceras cordiforme, Avicula beedei, Astarte paclcardi, Pentacrinus astericus, Tancredia bulbosa, 

T. magna, Lima lata, Goniomya montanaensis, Avicula macronatus, Pleuromya subcompressa, 

Oardinia wyomingensis, Pseudomonotis curta, Belemnites densus, and B. curtus, and also remains of 

plesiosaurs and ichthyosaurs; bed No. 14, Oamptonectes bellistriatus, 0. extenuatus, Ostrea densa, 

and 0. strigilecula)· in a sandy limestone bed in base of bed No. 15, Pentacrinus astericus, Asterias 

dubium, Pseudomonotis curta, Avicula macronatus, and Ostrea strigilecula.a 

The Jurassic of the Black Hills is represented by the Sundance formation 

and probably by the Unkpapa sandstone (local) and the Morrison formation, 

although the latter two may prove to be of Cretaceous age. (See Chapter XIV, 

pp. 606-608.) Darton 237 d says: 

This name [Sundance formation] has been given to the marine Jurassic sediments of the 

Black Hills region, from the town in the northern portion of the uplift. The rocks are shales 

and sandstones in a series, some members of which vary locally. Over a wide area the succession consists of a lower member of dark-gray shales, averaging 50 feet thick; a prominent ledge 

of fine-grained sandstones of pale-buff tint; an intermediate member of sandy shales and sandstones of reddish color, and at the top about 150 feet of dark-green shale, including thin layers 

of very fossiliferous limestone. * * * Fossils occur also in the sandstone and all are of 

later Jurassic age. At the base of the formation there is often a massive red or buff sandstone 

occurring in extended lenses, and frequently attaining a thickness of 25 feet, lying unconformably. * * * 

This formation extends along the slope of the Laramie Range, presenting its usual characteristics to the northward but thinning rapidly to the southward. In extensive exposures at 

the east end of Casper Mountain it has a thickness of about 350 feet. At the base overlying the 

n The spellings of fossil names in this list have been made to agree with those given by Logan in the article 

cited by Darton (Kansas Univ. Quarterly, vol. 9, 1900, pp. 112-113).-B. W. 
570 INDEX TO THE STRATIGRAPHY OF NORTH AlVI:ERICA. 

limestone, which is supposed to represent the top of the Chugwater red beds, there are 20 feet 

or more of white to red sandstones, then a few feet of buff sandstones and shales with an 8-foot 

bed of gypsum, and finally an upper series of dark shales with limestone layers and concretions 

filled with characteristic fossils, including many Belemnites densus. 

Along the North Platte River, in its big bend south of Douglas and to the west on Wagonhound Creek, the succession is as follows, from the bottom up: 30 feet or more of massive gray 

sandstone; 30 feet of pale-greenish sandy shales; 5 feet of soft greenish massive sandstone; 40 

feet of bright-reddish sandy beds; 15 feet of massive buff sandstone; and at the top about 200 

feet of green shales with a few thin beds of sandstone and limestone containing many upper 

Jurassic fossils. 

The formation appears again on Chugwater and Horse creeks, consisting of an upper 

series of 30 feet of soft slabby sandstones, gray at the base and buff toward the top, with ripplemarked layers and much intercalated shale, and a lower series 50 feet thick, mostly of green and 

gray shale, with layers of soft thin-bedded greenish-gray sandstones lying on the Chugwater 

formation. * * * 

This formation appears on the banks of North Platte River northwest of Guernsey and for 

some distance northward. The lower 145 feet are sandstones with a few thin beds of shales, 

over which there are 60 feet of interbedded slabby sandstones and clays, all containing characteristic marine Jurassic fossils. * * * 

The Sundance formation extends only a few miles into Colorado from the northward, finally 

ending by thinning out. Dr. Hayden found fossils, "Ostrea and fragments of Pentacrinus asteriscus," on Box Elder Creek, in yellow sandstones and clays, with scattered layers or nodules of 

limestone. He suggested that the limestone sometimes found at the base of the Morrison 

formation may be a representative of the marine Jurassic, a suggestion based on its si~ilarity 

in character and relations to a limestone on the Laramie plains, which contains Apiocrinites. 

As similar limestones exist in typical Morrison beds to the northward, where the marine Jurassic 

is represented, I feel certain that all those in the Front Range are of Morrison age. * * * 

The Jurassic appears to exist only in the northwestern portion of the region to which this 

report relates, apparently owing to nondeposition in other portions of the region. In the Bighorn Mountains and Black Hills it is represented by from 300 to 400 feet of deposits, but these 

thin gradually to the southward in the Laramie Range and disappear in the northern portion 

of Colorado. The thinning appears to be general at the outset and the upper beds probably 

disappear first, but this point has not been definitely determined, and it may be that the 

upper beds merge into sandy beds and these thin out gradually together with the underlying 

sandstones. 

The formation is evidently of marine origin, as indicated by its numerous molluscan remains, 

and its age is regarded as late Jurassic. It has not been divided into subordinate members, 

but in its regular succession it presents a succession of beds and faunas which are constant over 

a wide area, especially the sandstone near the base and the green shales above containing numerous Belemnites densus. It is probable that the Sundance formation does not extend far east 

of the Black Hills, nor to the southeastward of the locality at which it disappears in surface 

outcrops in northern Colorado, but there is no direct evidence on this question. 

The Unkpapa sandstone, which succeeds the Sundance formation along the eastern side 

of the Black Hills, is a relatively local feature of unknown age. It appears to represent a local 

shore deposit in late Jurassic times, prior to the deposition of the Morrison beds. The horizon 

may possibly be represented in other regions by the almost general occurrence of a yellowish 

sandy bed at the top of the Sundance formation. If not, it is probable that in the area in which 

it is absent there is a small unconformity or hiatus at this horizon. There is a very abrupt 

change from the Sundance to Morrison sediments, but no direct evidence of unconformity has 

ever been found. 

The latest notes on the Jurassic fauna of the Black Hills are given by Whitfield 

and Hovey.928 Summary statements concermng the correlation of the faunas are 

given by Stanton.782 
JURASSIC. 571 

L 11. EASTERN OREGON. 

In the Blue Mountains of eastern Oregon occurs a red sandstone from which 

Jurassic fossils were obtained on Beaver Creek, a tributary of Crooked River. The 

fauna is that of the Hardgrave sandstone of the Taylorsville district, California, 

and is assigned by Hyatt 468 to the Lias (Lower Jurassic). Hyatt mentions other 

localities at which there are characteristic occurrences of the same fauna and infers 

a connection between them extending from Inyo County, Cal., to the Blue Mountains. 

L 12. MONTANA AND WYOMING. 

The Jurassic of the Philipsburg quadrangle, Montana, Is thus described by 

Calkins: a 

The beds immediately overlying the Quadrant formation in the Philipsburg quadrangle in 

southwestern Montana are correlated with the Ellis formation on lithologic and paleontologic 

grounds. 

The Ellis in this area consists mainly of calcareous shales and sandstones and impure 

ferruginous limestone; locally it contains, near the middle, some conglomerate whose pebbles 

are mainly of chert like that in the :Niadison limestone. These rocks all weather in ocheryellow colors which are characteristic of the formation as here developed. 

The thickness of the formation on Gird Creek about 5 miles southeast of Stone, :Mont., is 

about 400 feet. It is thinner in places and seems locally to be absent in a small area southeast 

of Twin Peaks. It appears to be structurally conformable with the Quadrant, but the absence 

of any deposits belonging between the Carboniferous and Jurassic marks a distinct hiatus. 

T. W. Stanton has collected characteristic Ellis fossils from the formation on Gird Creek 

and on the Ovardo road about 6 miles east of Drummond. Those collected on Gird Creek lie 

from 50 to 100 feet above the Quadrant formation. They comprise the following forms: 

Ostrea strigilecula White. 

Camptonectcs pcrtenuistriatus H. and \Y. 

Eumicrotis curta Hall. 

Trigonia sp. 

Pleuromya subcompressa Meek. 

In this section east of Drummond calcareous beds from 200 to :2.50 feet above the Quadrant 

have yielded: 

Rhynchonella gnathophora Meek. 

Ostrea sp. 

Camptonectes bellistriatus Meek. 

Lima? sp. 

Cucullea haguei Meek. 

Tancredia? sp. 

Pleuromya subcompressa. 

A conglomerate near the top of the Ellis formation here contains Rhynchonella gnathophora 

Meek, Ostrea sp., and Gervilia sp. 

For an account of the Ellis formation as developed in Yellowstone Park, the 

Yellowstone folio 392 may be consulted. In that region the formation consists of a 

lower limestone division and an upper one chiefly of sandstone. The limestones 

are impure, argillaceous and gray, and associated with shales, and they carry marine 

fossils at several horizons. The upper sandstone member varies from a coarsely 

crystalline, fairly pure limestone carrying an abundance of fragmentary fossils to a 

true sandstone with conglomerate layers. 

a Unpublished manuscript. 
572 INDEX 'TO THE S'l'RATIGRAPHY OF NORTH AMERICA. 

The latest account of the Ellis formation in Montana is by Fisher, 332 who states 

that it- · 

includes a basal limestone of variable thickness, ranging from 15 to 60 feet, which in places 

merges upward into a coarse conglomerate that passes into a medium-grained sandstone, light 

brown to gray in color and more or less thin bedded. In other localities, however, the change 

from limestone to conglomerate is abrupt. The limestone and conglomerate contain marine 

Jurassic invertebrate fossils. Some of those in the conglomerate are fragmentary, but more 

are complete, with pebbles of limestone and quartzite several inches in diameter. The component parts of the conglomerate are bound together by a calcareous cement. The total thickness of the formation is about 80 to 120 feet. It rests unconformably upon the shale of the 

Quadrant formation in certain parts of the field, and upon the Madison limestone in others.* * * 

The following sections illustrate the succession of the beds of the formation in different 

parts of the field: 

Section of Ellis formation near Goodman siding, Montana. Fe~t. 

Sandstone, massive, light brown to gray, weathering tan, conglomeratic and fossiliferous at base. 66 

Limestone, reddish brown, fossiliferous._... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 

Beds concealed (estimated).... . . .. . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 

90 

Section of Ellis formation at head of Ming Coulee, Montana. 

Feet. 

Sandstone, gray, weathering brown, thin bedded............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 

Sandstone, gray, conglomeratic, containing marine Jurassic fossils........................... 29 

Limestone, dove-colored, massive; basal member brecciated and containing Jurassic fossils... 60 

149 

Fossil invertebrates, mainly Ostrea and Camptonectes, are present in great abundance in 

the two lower members of the above section. The numerous specimens of these genera and a 

few other forms are sufficient to determine that the rocks belong to the Ellis formation, which 

in the Yellowstone National Park and neighboring areas yields a characteristic upper Jurassic 

fauna. The sandstone of the Ellis formation throughout the Great Falls region is usually not 

fossiliferous, but the conglomerate and underlying limestone contain an abundance of Jurassic 

fossils. 

The Morrison formation, which ~.s regarded as probably Jurassic by some 

geologists, is described with the Lower Cretaceous in Chapter XIV (pp. 606-608). 

L-M 10. OLYMPIC PENINSULA. 

Arnold 29 refers to supposed pre-Cretaceous rocks in the Olympic Peninsula of 

Washington, which he mapped as Jurassic and which are so shown on the map of 

North America, as follows: 

The formations involved in the geology of the coastal region of the Olympic Peninsula 

include serpentine, old diabase or greenstone, metamorphosed sandstone and quartzite, probably of Jurassic age; 6,000 feet of gray sandstone with minor quantities of carbonaceous shales, 

supposed to represent the lower part of the Puget group and of Cretaceous age; 1,200 feet of 

basalt and basalt tuffs of Eocene age; 15,000 feet of Oligocene-Miocene conglomerate, sandstone, and shale; 2,260 feet of Pliocene conglomerate, sandstone, and shale; and at least 300 

feet of Pleistocene till, clay, and gravel. In addition to this, the Oligocene-Miocene breccia 

contains large quantities of angular fragments of hard black slate, indicating a probable widespread formation of this type of rock somewhere•in the general region. Nothing is known of 

the age of the slate except that it is pre-Oligocene. 

The supposed pre-Cretaceous rocks of the territory examined were confined entirely to the 

coast south of Cape Flattery, the most important areas occurring at Portage Head, 8 miles 
JURASSIC. 573 

south of the cape, Point of the Arches, 3~ miles still farther south, and in the region from Point 

Greenville south to within a few miles of Grays Harbor. The types of rock composing this old 

series embrace old diabase or greenstone, serpentine, quartzite, conglomerate, etc. 

These rocks are also described by Reagan 664 as follows: 

Rocks supposed to be pre-Cretaceous in age are found in the central Olympic region, in the 

central ridge which extends westward from the Olympics to Cape Flattery, and on the Pacific 

front at Portage Head, 8 miles south of Cape Flattery, and at the Point of the Arches, 4 miles 

farther south, and in the region from Point Granville south to within a few miles of Grays 

Harbor, and a few other smaller exposures along the Pacific shore line. So far no rocks of this 

age have been found on the north slope of the peninsula. * * * 

The series containing the syenite, gneiss, quartzite, protogene, crystalline and chlorite 

schists is here placed by the writer in the supposed Cretaceous. Its approximate area is not 

known, neither is its thickness where the central core of the western extension of the Olympics 

is exposed. Along the east and west axis of the western part of the peninsula, at Beaver Falls, 

in the East Clallam-La Push wagon-road, [it] is composed of a very hard dark-gray plutonic 

rock of more than 10,000 feet in thickness. This core, however, is exposed only in patches. 

Its greatest. thickness is in the vicinity of Clallam Peak. Toward Cape Flattery it is capped 

with sedimentary deposits. Here it is composed of metamorphosed sandstone and quartzite. 

It may prove to be of Eocene age. 

At Portage Head, Point of the Arches, and at Point Granville the type rock of this old 

series is conglomerate, quartzite, old diabase or greenstone, serpentine, etc. 

This old series, wherever found, is much fractured and faulted and cut by quartz veins, 

which occasionally carry gold and silver in small quantities. The principal veins carrying 

precious metals are found in the Point of Arches group and in the vicinity of Clallam Peak and 

Beaver Falls. An odor of benzine is also given off from the serpentine and conglomerate rocks 

of this group in the Point of the Arches, derived likely from the shales that are found a mile 

farther south. There are no other shales or oil-producing rocks in the vicinity; the age of these 

shales is in doubt, but they are Cretaceous or still younger. 

M 10. WASHINGTON AND BRITISH COLUMBIA. 

A western occurrence of supposed Mesozoic strata is exposed on the northern 

portion of Nooksak River and is thus described by George Otis Smith: 757 

For some miles below Shuksan the outcrops on the walls of the canyon of the north N ooksak 

are of sedimentary rocks distinctly less metamorphosed than those assigned to the Paleozoic. 

They are mainly sandstones, with s.ome cherty layers and conglomerates. Green colors are 

rather characteristic of all the rocks. At Austin Pass there are greenish sandstones and banded 

shales which show on the average about the same degree of induration as the similar rocks of 

the Pasayten formation. On lithologic grounds, then, it appears probable that there may be a 

belt of Mesozoic rocks trending northwest from Austin Pass. 

There is, moreover, some paleontologic evidence bearing on this question. In 1898 there 

were sent to Mr. J. S. Diller by Mr. W. H. Fuller, of Fairhaven, Wash., some fossils collected 

on Cowap or Canyon Creek and on the ridge north of it. Mr. T. W. Stanton examined the 

material and reported on it as follows: 

"The * * * fossils * * * are evidently all from one horizon, which I believe to 

be upper Jurassic, this opinion being based chiefly on the distinctly striated form of Aucella, 

identified with A. erringtoni (Gabb) of the California upper Jurassic Mariposa beds. This 

species was collected at both localities. The collection from Canyon Creek includes also a 

fragmentary Pleuromya and the impression of a small belemnite. 

"The collection from the divide between Canyon Creek and the waters of Fraser River 

contains the Aucella emngtoni, a fragment of an ammonite apparently belonging to the genus 

Stephanoceras, a small, slender belemnite like that from the last-mentioned locality, and the 

phragmacone of a large, robust belemnite." 
57 4 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

M 11. SOUTHWESTERN ALBERTA. 

The Fernie shale, which was originally included by Dawson in the Cretaceous 

as part of the Kootenai formation, has been separated and is described by Dowling. 292 

In the Cascade coal basin, Alberta, it consists of black shales with gray sandstones 

and local limestone beds which occupy the same position relatively to the Kootenai 

of the older rocks beneath as a similar series at Fernie, where there are Jurassic 

fossils. The thickness is given as approximately 1,600 feet. 

The relations of the Jurassic and Lower Cretaceous of British Columbia are 

discussed in Chapter XIV (pp. 624-630). 

M-0 9-10. WESTERN BRITISH COLUMBIA. 

Dawson's descriptions of the "Porphyrite group" (Jurassic~) are given m 

Chapter XIV (p. 627). 

0 4-5. ALASKA PENINSULA. 

The Alaska Peninsula is composed largely of Mesozoic rocks, which, though 

known to comprise several terranes, have not yet been separated in mapping but 

are grouped under the color which indicates Jurassic. Brooks 101h gives a general 

account of the history of investigation of the:;e strata. The latest and most complete study of the section as yet made is that of Stanton and Martin, 786b to whose 

account reference should be made for detailed sections and a statement of the 

stratigraphic relations, which they sum up as follows: 

The Mesozoic section of southwest Alaska includes representatives of the Upper Trias, 

Lower, Middle, and Upper Jurassic, Upper Cretaceous, and probably Lower Cretaceous. 

The Jurassic shows the greatest development, both stratigraphically and faunally, and is 

probably unequaled in these respects elsewhere on the American continent. The total thickness 

can not be much less than 10,000 feet, and the areas covered by the upper half of the Jurassic 

are large. 

The faunal type is essentially Russian-that is, boreal-though it differs in the common 

occurrence of Phylloceras and Lytoceras at several horizons. The succession of the faunas 

from the Callovian to the top of the Jurassic is the same as in Russia, but the vertical thickness 

of beds through which each ranges appears to be very much greater in Alaska. 

The Cretaceous and Triassic rocks so far as now known occur only in small scattered areas, 

and their faunas may be directly correlated with those of formations in California and elsewhere 

on the Pacific coast. 

The general relations of the formations may be epitomized in the following section: 

Tertiary.-Kenai formation. Shales, sandstones, and conglomerates with several beds of coal. The entire formation 

nonmarine and characterized by a large flora. Thickness, ±2,000 feet. 

Unconformity. 

Upper Cretaceous.-Lithologically similar to the Kenai, but including some marine shales and sandstones with an Upper 

Cretaceous fauna. Thickness, ±1,000 feet. 

Unconformity. 

Lower Cretaceous.-(Not seen within the area studied.) Shales and sandstones with Aucella crassicollis. 

Unconformity(?). 

Upper Jurassic.-Naknek formation. Conglomerate, arkose, sandstone, and shale with interstratified andesite flows. 

Thickness, about 5,000 feet. 

Middle Jurassic.-Enochkin formation. Shales and sandstones with some conglomerate beds. Thickness, 1,500 to 

2,500 feet. 

Unconformity(?). (Possibly conformable on Lower Jurassic when that is present.) 

Lower Jurassic.-Tuffs and sandstones. Thickness, ±1,000 feet. 

Unconformity. 

Upper Triassic.-Thin-bedded cherts, limestones, and shales usually much folded and contorted and with many intrusive masses. Thickness, ±2,000 feet. 

Base not seen. 
JURASSIC. 575 

Martin 574 describes the district north of Alaska Peninsula and states the 

sequence of rocks as follows: 

The region described in this report covers an area of about 4,900 square miles, situated in 

southwestern Alaska, west of the southern half of Cook Inlet and north of the Alaska Peninsula. 

It comprises the greater part of the drainage basin of K vichak River, which is the outlet of 

Iliamna and Clark lakes, and of the streams flowing into Cook Inlet from the west, south of 

and including Tuxedni Bay. It lies between the parallels of 59° and 60° 30' north latitude and 

the meridians of 152° 30' and 157° west longitude. 

Most of the northeastern part of this region lies within tha Chigmit Mountains and consists 

of high, rugged mountain masses with narrow intervening valleys. The general elevation of 

these mountains is from 4,000 to 6,000 feet, although many peaks near the north end of 

Clark Lake are 7,000 feet high, and the highest peak of the whole district is Mount Iliamna, 

between 9,000 and 10,000 feet. 

At Iliamna Bay the mountains extend eastward to the waters of Cook Inlet. Both north 

and south of this point a belt of foothills and lowlands from 2 to 10 miles in width reaches from 

the edge of the high mountains to the shore of the inlet. Much of the coast is deeply embayed: 

Tuxedni Bay, Iniskin Bay, and Iliamna Bay extending into the high mountains, ·while the other 

bays have their heads in the foothill belt. * * * 

The following table shows what is now believed to be the probable geologic sequence: 

General section of rocks in the Iliamna and OZark lakes region. 

Age. Lithologic character. Areal distribution. 

·-

Qua ternary. Beach and flood-plain deposits, 

gravels, and glacial till. 

terrace Entire region. 

-

Basaltic flows and tuffs with some inter- Iliamna Lake. 

bedded sandstone. 

Tertiary. --------

Shale, sandstone, and conglomerate. Cook Inlet. 

---

Upper Jurassic Shale, sandstone, conglomerate, arkose, 

and tuff, with interbedded andesitic 

Cook Inlet. 

flows. 

' --

Middle Jurassic. Sandstone, shale, and conglomerate. Cook Inlet. 

Middle or Lower Jurassic. Granite, quartz, diorite, etc. Chigmit Mountains. 

-· 

Lower Jurassic or older. Rhyolitic and andesitic porphyries and I Cook Inlet, Iliamna Lake, ClarkLake, east 

tuffs. of Clark Lake. 

Upper Triassic. Chert, shale, and limestone. Cook Inlet. 

Tuffaceous greenstones. Iliamna Bay, Pil0 Bay, Kakhonak Bay, 

Clark Lake. 

Triassic or older. 

Limestone. Iliamna Lake, Iliamna Bay, south of 

Iliamna village (?). 

Late Paleozoic. Slate and chert. Iliamna Bay, Clark Lake, east of Clark 

Lake. 

Limestone and calcareous schist. Clark Lake, south of Iliamna village (?). 

Paleozoic. ' 

Gneiss, mica sc;hist, and quartzite, with We~t of Iliamna Bay, south of Iliamna some crystallme marble. v1llage, Clark Lake. 
576 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

0 8. ATLIN LAKE, BRITISH COLUMBIA. 

Gwillim, 389 in reporting on the Atlin Lake gold district, describes an extensive 

area of sandstone and conglomerate about the southern end of Taku and Atlin lakes. 

The rocks are classed as Mesozoic but were not seen in contact with Paleozoic formations. "Their origin is chiefly igneous and they often pass imperceptiby from a 

sedimentary and stratified form into the mountain masses of porphyrite and andesite. 

The few fossils found in some of the bedded sandstones appear to belong to the 

Jurassic period." This general statement is followed by a more detailed description, 

as follows: 

The prevailing variety of this sandstone series is of a greenish-gray color. It is usually 

in heavy beds. There are occasional bands of a darker and more argillaceous-looking material, 

also some thick deposits of thinly bedded fine-grained black a_nd gray material. Conglomerates 

occur somewhat rarely. Such beds usually contain very coarse bowlders, as large as 3 feet in 

diameter. These bowlders are principally granite, with sometimes a considerable number 

consisting of crystalline limestone and porphyrite. 

A very good section of this sandstone formation is found on the west side of Tory Inlet on 

Atlin Lake. An anticline occurs at this point. The northern slope of the beds forms the 

abrupt eastern face of Section Mountain. This section shows over 5,000 feet of thickly bedded 

sandstone of the greenish-gray false-bedded variety interbanded with some finer-grained beds 

of darker material. The upper portion of these beds is without conglomerate. The lower beds 

contain some narrow bands of which the bowlders are usually small and consist principally 

·of granite and porphyrites (hornblende and andesite porphyrite). , 

From microscopic examination of several specimens of this series, they appear to be of 

pyroclastic origin. 

* * * * * * * * * A few fossil forms were found in some of the darker fine-grained beds of this series of rocks. 

* * * From field conditions and lithological resemblance, this series of rocks was at first 

believed to be Cretaceous in age. The examination of the few fossil forms appears to place 

them in the Jurassic. * * * The following is a note on the specimens of fossils collected on 

Atlin Lake during the season of 1900 and submitted to Dr. H. M. Ami, for examination: 

"The fossils are preserved for the most part in a rather imperfect manner in a dark, at times 

streaky, gray fine-grained calcareous rock, which, when examined in thin sections under the 

microscope, reveals the structure of a porphyrite or andesite tuff. * * * The fossils are for 

the most part fragmentary * * * but they represent several small ~ollections * * * 

and possibly different horizons in the Mesozoic. It is very difficult to state precisely what is the 

age of the strata, * * * both on account of the condition in which the fossils are themselves 

preserved and on account of the fact that the fauna represented is practically a new and hitherto 

unrecognized one in that portion of North America. * * * The presence of a few ammonites, 

which had the general outward appearance of Arniotites not unlike A. vancouverensis seemed to 

indicate a similar horizon to that of the Triassic system of the Cordilleran belt, but as none of 

these ammonites show any of the sutures, it is impossible to state precisely in what section or 

division to place them." 

Some of the most typical of these fossils were sent to Dr. T. W. Stanton, of Washington. 

He found it difficult to determine the ammonites even generically, since they showed no sutures. 

He says: 

"These may possibly be Triassic, but I think it more probable that they are early Jurassic. 

They are certainly not as late as the Cretaceous." 

P 8. LEWES RIVER, YUXON PROVINCE. 

For a description of the conglomerate and sandstones near Lake Labarge, 

which Stanton considers probably Jurassic, see Chapter XV (p. 701). 
JURASSIC. 577 

R 3. NORTHWESTERN ALASKA. 

The coast northeast of Cape Lisburne exhibits a section of strata constituting 

two formations, the lower one coal bearing and according to its fossil plants of 

Jurassic age, the upper one unfossiliferous. Collier 164a' 165JJ has described these formations as follows: 

Mesozoic rocks occur on the coast about 3 miles east of Cape Lisburne and extend beyond 

the limits of the area covered by this investigation. They consist of two members, of which 

the older is coal bearing while the younger is not only destitute of coal but also of fossils. 

The coal-bearing member, which has been called the Corwin formation, begins on the coast 

line about 26 miles east of Cape Lisburne and about 2 miles west of Corwin Bluff. From this 

point it extends eastward to and beyond Cape Beaufort, the eastern limit of the area comprised 

in this investigation. This formation consists of rather thin bedded shales, sandstones, and 

conglomerates. The shales which form the greater part of the section, vary from greenish-brown 

calcareous to black carbonaceous beds, and in texture from mudstones to fine-grained sandy 

shales. · 

The sandstones occur at infrequent intervals through the formation, in beds usually less 

than 10 feet in thickness. Their outcrops form low ridges, which are easily traceable over 

eroded areas. The conglomerates are made up mainly of quartz and chert pebbles, ranging in 

diameter from one-half to 4 inches. A conglomerate bed about 15 feet thick, which reaches 

the coast at Corwin Bluff, makes a distinct ridge from 100 to 200 feet high, which has been 

traced southeastward for about 15 miles, giving a definite key to the stratigraphy of a portion 

of the field. 

The thickness of the Corwin formation exposed along the coast near Corwin Bluff is not less 

than 15,000 feet. The base of the formation has not been observed, but it probably rests unconformably on the Paleozoic rocks. 

Fossil plants collected from it indicate that the age is Jurassic. 

The structure consists of several broad synclines and anticlines, the dips of the beds varying 

from 0° to 60°. There is no evidence of faulting other than minor shearing movements parallel 

with the bedding planes. 

The Corwin formation is conformably overlain by a more arenaceous series of sandstones 

8Jld shales in which neither coal beds nor fossils have been found. The contact of these rocks 

with the Corwin rocks may be seen about 2 miles west of Corwin Bluff, whence it extends southeastward for several miles to the limit of the area investigated. The western limit of the formation is a well-defined fault line extending southeastward from a point on the coast 3 miles east of 

Cape Lisburne, where the formation is in contact with the Paleozoic, which is overthrust. The 

structure of this formation increases in complexity from its base at the top of the Corwin formation as this fault is approached; there are intense crumpling and numerous minor thrust faults. 

For this reason it is impossible to estimate the thickness of the formation, but the evidence 

obtained indicates that its minimum thickness is not less than 5,000 feet. 

R-S 27. NORTHEAST COAST OF GREENLAND. 

Nathorst 609a gives the following description of the Jurassic strata on the northeast coast of Greenland: 

Jurassic strata occur at two localities on Kuhn Island, on the south side and on the east 

side. At the first-mentioned place they consist of brownish fine-grained sandstones, with an 

inclusion of coal strata. There are in the sandstones fossils which, according to Y oula, indicate 

the Middle Dogger. Of quite a different age are the sandstone and marl beds that are found 

about the easternmost point of the island; they are distinguished by a great richness in forms 

from the family Aucella, and further of Perisphinctes payeri, Belemnites panderianus, besides 

others, and are therefore referable to the youngest Jurassic, the Aucella beds. The Jurassic at 

both localities is given as resting directly on the Archean. * * * 

48011°--12----37 
578 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Above the Rhretic beds come others with marine fossils described bj Lundgren. Aucella 

are completely absent, and Lundgren thinks that these beds should be referred to the Kelloway 

stage of the Jurassic system, and that they are very likely closely allied to the fossiliferous beds 

on the south side of Kuhn Island. Identifiable ammonites and belenmites were not fcmnd in 

the samples that were brought home, and most of the specimens are lamellibranchs belonging 

to the families Ostrea, Pecten, Avicula, Modiola, Astarte, Panoprea, Pholadomya, Lyonsia, and 

others. The fossils occur in an impure limestone that in places becomes conglomeratic or even 

changes into shell breccia. The fossil-carrying bed is 2.2 meters thick and is overlain by gray 

sandy slates, yellowish sandstones, etc., without fossils. A basalt bed 3 meters thick is interbedded with the nonfossiliferous layers. The beds dip about 6° S. 50° W. and rise therefore 

toward the inner part of J urry Inlet. 
Color, Medium green. 

Symbol, 8. 

CHAPTER XIV. 

LOWER CRETACEOUS. 

Distribution: Atlantic, Gulf, and Caribbean coasts; New Jersey to South America; Pacific 

coast, Alaska to South America. In Mexico areas mapped include Upper Cretaceous. 

Content: Potomac group of the Atlantic slope, Georgia, and eastern Alabama ; Comanche 

series (comprising Trinity, Fredericksburg, and Washita groups) of Texas, Oklahoma, and 

Mexico; Shasta series (Knoxville and Horsetown formations) of California and Oregon; 

Queen Charlotte group of British Columbia; Kootenai formation of the Rocky Mountains, 

Montana northward to fifty-second parallel and beyond; Lower Cretaceous, Alaska. 

Lower Cretaceous areas. 

B-C 18 ........................ Colombia ..................................................... ___________ _ 

B-C 19-20 ....... _. _. _. _ ... _ ... Venezuela. __ . ____________________ ...... ___ ... ___ ._. ___ ... ___ ............ . 

C 20 .•......................... Trinidad ................................. _ ........ _ ..................... . 

C 17, D 16 ...... _ ............. Honduras and Costa Rica ................................................. . 

D-E 15-16 .................... Guatemala and Chiapas ................................. _ ................ . 

E 14 ............ , .............. State of Vera Cruz, eastern slope of the Mexican Plateau .................... . 

E 15 ................ _ ..... _._._Isthmus of Tehuantepec .................................................. . 

E-H 12-15 ..................... Mexico in general. ................................ _ ...................... . 

F 14 .......... _ ..... _. _._._ ... San Luis Potosi ................................. _ ........... _ ..... _ ...... . 

G 13-14 ............ _. _ .. _____ .. Sierra de Mazapil, Zacatecas .............................................. . 

H 12 .................... _ .... Southeastern Arizona and Sonora .......................................... . 

H 13 ......................... Quitman Mountains, trans-Pecos Texas ... _ .... __ ..... _ .. _ ...... _ ..... __ ... . 

II 13 ...................... _ . _ Chisos region, Texas ...................................................... . 

H 13 ..... _. _ ..... _. _. _._ ..... Texas, near El Paso, and Chihuahua, Mexico . _ ............................ . 

H 14 .................... _ .... Llano-Burnet region, Texas ............................................... . 

II-I 14 .................. _._ .. Central Texas ...................................................•......... 

I 14-15 ...... __ ... _ .... ____ ._.Northern Texas, southern Oklahoma and Arkansas, and northern Louisiana .. . 

I 16-17 ....... _ ............. _.Alabama, Georgia, and South Carolina ..................................... . 

I-J 13-14 ...... _ ..... _ ... _ .. _.Eastern New Mexico, Oklahoma, and southern Kansas (not mapped) ........ . 

I-K 13 ............... _._ ..... New Mexico, Colorado, and Wyoming (not mapped in general) ............. . 

I-K 17-18 ..................... Atlantic Coastal Plain, Massachusetts to North Carolina, inelusive ........... . 

J 14 ........ _. _. _. _. ___ . ___ ._.Central Kansas (not mapped) ............................................. . 

J-K 10 .. __ . _ . _ .. _ .. _ .... _ . _ .. California ................................... __ ... _ .......... _ ... _ ........ . 

K 10 ..... _. _. _ .. ' .... _._._._.Klamath Mountains, Oregon and California ................................ . 

L 10 .. _. ____ . ___ . _. _ .......... John Day Basin, Oregon ................... _ ............ _ ....... __ .. _ ...... . 

L 12 .. _. ___ . _. _. _. _. _________ .Southwestern Montana (not mapped) and central Montana ...... _. _ ......... . 

M 10 ..... _. _ .... _ ........ _ ... Washington and British Columbia ........... _ ........... _ .. _ ....... _ ...... . 

M ll-12 ... _. ___ . _. ___ .. _____ .Canadian Rockies, Alberta and British Columbia .............. _ ............ . 

M 10, N 9-10, 0 9 ... _. _____ ._.·western British Columbia .... _ ........................................... . 

N 8-9 ..... _. __ ........ _ .... _ .. Queen Charlotte Islands ......................................... _ ........ . 

N 9 ..... _________ . _. _. ___ . ___ . Telkwa River district, British Columbia .................................. _. 

N-0 4 ............. _ .. , .. _ .... Alaska Peninsula (mapped with Triassic and Jurassic) ............... _ ...... . 

0 8 ........... _ ............... Southeastern Alaska .......... _ .............. _ ... _ ................. _ ... , .. . 

0-P 4 ....... _ ....... _ ... _._ .. Lower Yukon and Kuskokwim basins, Alaska ............ _ ............ _ .... . 

P 8 .................. _. _._._._.Southern Yukon Territory and British Columbia (not mapped) .............. . 

Q 4-5 .............. ______ ._ .... Koyukuk basin, Alaska ............................................ . 

Q 7 ............... _ .... _ ... _ ... Upper Yukon, Alaska ................................................... . 

R 3 ............ _. _ .... ________ Cape Lisburne, northwestern Alaska ...................... _ ......... _ ...... _ 

R 5 ........................... Northern Alaska, Arctic slope ............................................. . 

579 

Page. 

581 

583 

584 

585: 

585 

587 

588 

589 

591 

592 

592 

594 

595 

596 

598 

601 

604 

605 

606 

606 

608 

614 

615 

617 

621 

621 

623 

624 

625 

628 

630 

631 

632 

633 

634 

635 

635 

636 

636 
180" "' l\!lo o' ~ ~~ 

174 6' 

.FIGURE 16-Sketch map showing the distribution of Lower Cretaceous rocks represented on the geologic map of North 

America and the key to references in the text. 

580 
LOWER CRETACEOUS. 581 

B-C 18. COLOMBIA. 

We are indebted chiefly to Hermann Karsten, ma a physician and botanist, for 

our knowledge of Colombia, and for the portion of that country shown on the map 

of North America we have followed his text. He distinguishes five terranes, of 

which the oldest is the Jurassic, recognized at but one locality in New Grenada. 

The next, the Lower Cretaceous, outcrops extensively throughout the mountains 

and is distinguished by a great variety of cephalopods. Karsten suggests that the 

terrane may probably be divided into two formations owing to the presence of 

belemnites, Ptychoceras, Humboldtianus Krst., Ammonites noeggeratii Krst., Am. 

rothii Krst., Am. santajecinus d'Orb., Am. boussingaultii d'Orb., and Hamites 

arboleda; Krst., in the lower beds, which are principally marls. The third series, 

that of the Upper [~] Cretaceous, consists of thick deposits of limestones, sandstones, and siliceous shales and is identified paleontologically by a great number of 

Rudistes which appear in the eastern portion, and of Polythalamies [Foraminifera], 

which occur very extensively in the central and western districts. 

Succeeding these Cretaceous formations are Tertiary and Quaternary deposits 

concerning which Karsten is quoted in Chapter XVII (p. 796). In introducing his 

description of the Cretaceous, Karsten refers to the absence of any trace of Paleozoic 

rocks, and mentions specifically the discovery of Jurassic beds on the upper Magdalena in New Grenada. As these beds appear to belong to the Lower Jurassic 

(Liassic), it is possible that the Upper Jurassic is represented in the higher strata 

which underlie the Cretaceous. Karsten states: 

The oldest of the sedimentary formations is a sandy marl of a clear brown or yellowishred color and distinct stratification. It frequently is of great thickness and sometimes contains 

in the upper portion beds of blue or dark limestone which completely replace the marl in the 

higher sequence. Sometimes a reddish-brown marl which closely resembles the preceding contains flakes of mica or fragments of mica schist, as, for example, at Guaduas and at Bucaramanga. 

The latter marl is, however, probably of more recent date than that which appears in contact 

with the plutonic rocks and which is very poor in fossils, is ·without mica, firmer, etc. This 

nonmicaceous marl occurring in the lower beds is found in all the eastern chain 'as well as at 

several places in the central and western chains. It contains the following fossils: Ammonites 

santajecinus d'Orb., Am. noeggeratii Krst., Am. boussingaultii d'Orb., Ptychoceras humboldtianus Krst., Orioceras duvalii Lev. var. undulata Krst., and may therefore be regarded as the 

equivalent of the N eo co mien of Europe. At Cumanacoa remains of belemnites occur in a yellowish-red marl and in a black calcareous shale which lies upon it. * * * This marl has at 

Zapatoca a thickness of about 300 meters and is overlain by another bed which is also very 

thick, of reddish-yellow quartzose sand, that in turn is followed by clay shales and limestones 

of the horizon of the Gault, rich in fossil remains. The last-named lies upon beds of pebbles 

and conglomerates derived from these same strata. 

Karsten describes several localities at which these strata appear and continues: 

Although at the base of the Lower Cretaceous marls and shales predominate, the middle 

portion of the series consists chiefly of limestones and the upper part of sandstones. These 

sandstones here and there alternate with thick beds of siliceous shale and include also thin 

strata of clay shale which are generally white, light, or yellowish in color, and of fine grain. 

* * * In physical characters the beds resemble the Lower Cretaceous that immediately 

underlies them, but they may usually be distinguished by the organic remains, especially characterized by Inoceramus. The Upper is distinguished by an abundance of Polythalamies, 

Orbitolina, Robulina, Nodosaria, and similar species. In the accompanying limestones one 
582 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

also finds the shells of Rudistes and bivalves: Lucina, Cardium, Pecten, Ostrea, Exogyra boussingaulti d'Orb.; of echinoderms: Ananchytes ovata Lam., Micraster cor-anguinum Goldf., 

Discoidea excentrica d'Orb., Echinus bolivarii d'Orb., Enallaster lcarsteni de Lorio!, Galerites 

sp., etc. This group of siliceous rocks, whose thickness may be estimated roughly at 1,000 

meters, usually forms the summits of the eastern chain. The Paramo de Chita, which has an 

altitude of about 6,000 meters and is covered with eternal snow, [and other summits] are formed 

of these sandstones and siliceous shales. The beds which carry Polythalamies are unconformably overlain by micaceous sandstone which is either white or yellow and more or less 

coarse, or by sandstones and variegated marls containing beds of lignite. 

This last group is assigned by Karsten to the Tertiary and further description 

of it is given in Chapter XVII (p. 796). 

The geologic constitution of the Cordillera of Bogota was described in 1892 

by Hettner, 437 who distinguished several divisions of the Cretaceous as follows: 

Although various explorers have from time to time collected fossils, we are indebted particularly to Karsten for an attempt to distinguish the sedimentary rocks of Colombia. He 

separated Lower Cretaceous or N eocomien, Middle Cretaceous or Gault, which appears with 

two definite variations, Upper Cretaceous, and Tertiary. The classification which I have 

adopted during my journeys agrees in general with Karsten, and Sievers has adopted approximately the same classification for the Cordillera of :Merida in Venezuela. 

The characteristic rock of the N eocomien is, according to Karsten, a sandy light-brown or 

red-yellow, imperfectly stratified marl with interbedded strata of blue or dark-colored limestone which predominates in the upper portions. Karsten found fossils in one locality only, 

near Caqueza. I must admit that I have not discovered any and that I therefore must classify 

this formation with the following one, the Gault, inasmuch as they are not particularly different in lithologic character. The Lower Cretaceous (N eocomien and Gault) is therefore in 

general a thick series of clay slates, shales, and bright-colored shaly clays, which are inter.,. 

bedded witn thick strata of blue or more rarely black or white limestone, white quartzite, and 

white, sometimes reddish and greenish sandstones, as well as some other subordinate strata. 

Where they possess the t:vpical character I propose to call them the Villetas formation, and the 

greater part of the limestones of the Middle Cretaceous which Sievers has distinguished in his 

profile sections probably. The principal part of the Villetas formation has been determined 

by Steinmann as Urgo-Aptien on the basis of its fossils; whereas the upper strata belong to the 

true Gault. 

In the vicinity of Jiron and Zapatoca and elsewhere there occurs, in the neighborhood of 

the granite gneiss and porphyry, clay, reddish or white, and in part greenish sandstone which, 

together with violet-brown shales and reddish sandstones may be named the Jiron formation. 

This is the reddish-yellow sandstone which Karsten regarded as a special development of the 

N eocomien, and although there are fossils I would also class it as a portion of the basal Cretaceous 

that is peculiarly characterized. through proximity to the crystalline rocks. Sievers also regarded 

this formation, which occurs apparently quite frequently in the Cordillera, as the lowest member of the Cretaceous. Elsewhere, especially in the snow-covered mountains of Cocui, a 

white quartzite which usually occurs only in thin beds in the slates and clays becomes so thick 

that it replaces all other rocks. This Cocui quartzite probably corresponds to the Uribante 

sandstone of Sievers. The blue limestone may, however, become the predominant member 

and entirely replace the slates and clays, as is the case in the neighborhood of Velez. 

Toward the top the Villetas formation appears to pass by gradation into the next division, 

the Guadalupe (Karsten's Upper Cretaceous). The slates and shales become less frequent and 

occur only as thin interbedded layers. The greater part of this division is siliceous sandstone 

or a thin-bedded silicified clay rock, together with a heavy-bedded white quartz sandstone 

which in general overlies the other strata. Fossils are very rarely found and are not such as 

may be definitely determined. It is therefore doubtful whether the Guadalupe formation 

belongs to the Gault or to the Upper Cretaceous. 
LOWER CRETACEOUS. 583 

B-C 19-20. VENEZUELA. 

As regards the Lower Cretaceous, Sievers 741a in describing the Cretaceous 

rocks of Venezuela distinguishes conglomerate and breccia at the base, followed 

by red sandstone, yellow and white quartzose sandstone, and limestone. From 

the descriptions of these several formations, which consist chiefly of details of local 

occurrences, the following notes may be taken: 

The clay slates which are assigned by Sievers to the Archean and which for the 

sake of distinction have been placed by the present compiler in the metamorphic 

Paleozoic are unconformably overlain in many places in the Cordillera by massive 

deposits of conglomerate and breccia which Sievers calls the Lagunillas conglomerates. They consist of fragments of the "Archean" rocks embedded in a clay and 

sandy cement. Their horizontal extent is in places considerable; the thickness 

in the vicinity of Lagunillas is stated at 700 meters. Sievers leaves one in doubt 

as to whether the conglomerates should be assigned to the Cretaceous or not, saying: 

These conglomerates appear widely distributed throughout the Cordillera and always 

occur between the Archean rocks and the succeeding red and yellow sandstones which we may 

well regard as Lower Cretaceous. Sometimes they rest upon gneiss, as at Lagunillas, sometimes on clay slate, but they always constitute an intermediate member between the Archean 

and the Cretaceous. One is oblig.ed to regard them as a coastal formation developed around 

islands of the older gneiss and clay slate which now constitute the core of the Cordillera. The 

time at which these conglomerates were formed can not be determined with certainty, but they 

must be older than the red and yellow sandstone which we regard as the lowest member of the 

Cretaceous. It is therefore probable that they introduced this period. 

After citing the localities at which the Lagunillas conglomerate occurs, Sievt3rs 

continues: 

The conglomerate and breccia are followed by the Cretaceous series, to which most of the 

sedimentary deposits of the Cordillera belong and which occupies a much greater area than 

that of the Archean formations. The determination of the age of these formations depends 

essentially on a few fossils from the blue limestone of Tachira and Barbacoas, which are mostly 

ammonites and may be correlated with the Upper Albien of the Middle Cretaceous as determined by Prof. Steinmann. The strata which underlie these limestones are therefore older 

Albien. There are red and yellow standstones as well as the white sandstone. Unfortunately 

they are as a whole very poor in fossils, but they may be considered as Cretaceous, as in lithologic character they are very similar to the corresponding Cretaceous deposits of Europe. * * * 

The red sandstone follows directly upon the deposits of the Lagunillas conglomerate. 

It is mostly coarse and rich in m:Wa, though also sometimes fine grained, usually according to 

its relation to the conglomerate, whether directly deposited upon that formation or farther away 

from it. * * * 

At many points in the Cordillera de Merida we observed a white to yellow coarse-grained 

saccharoidal quartz sandstone which in many respects strongly reminds one of the Quader 

sandstone of Saxony. * * * Although this sandstone resembles the Planer (of Germany) 

and accordingly should be placed among the upper formations of the Cretaceous, it can not be 

denied that it occurs in the Cordillera under the limestone which is determined as equivalent 

to the Albien and outcrops together with the red sandstone. * * * The yellow sandstone 

frequently grades into the red but in general is much more widely distributed than the red 

sandstone. Where the red is entirely wanting -that is to say, throughout the eastern portion 

of the range-the white sandstone seems to replace it. 
584 INDEX TO THE STRATIGHAPHY OF NORTH AMERICA. 

In describing the Cretaceous limestone Sievers refers to classifications by Wall 

and Steinmann. He cites three divisions of the Older Parian group, so named by 

Wall in his "Geology of the Island of Trinidad," and finds a parallel with divisions 

recognized by him in the Cordillera de Merida. 

Referring to a report contributed by Prof. Steinmann on the fossils which 

Sievers had collected Sievers says: 

Steinmann infers that there are three limestone formations which may be distinguishe<l-

(a) the dark bituminous limestones of San Cristobal, with Exogyra; (b) the succeeding Barbacoas formation, with many ammonites; and (c), still higher, the broad crystalline limestone 

with many" poorly preserved fossils of Exogyra, Trigonia, Cardita, and Astarte, which occur 

extensively in northern South America. Of these formations the age of the Barbacoas alone 

can be determined accurately. It belongs to the Upper Albien, on the boundary between the 

Lower and the Upper Cretaceous, and is distinguished by the following fossils: 

Schlcenbachia inflata Sow. 

S. varicosa Sow. 

S. belknapi Marcou. 

Hoplites tocuyensis. 

Mojsisovicsia durfeldi Steinmann. 

Cardium peregrinorsum d'Orb. 

Inoceramus plicatus d'Orb. 

C 20. TRINIDAD. 

Wall and Sawkins 863a described the Older Parian group of the Island of Trinidad 

as Lower Cretaceous. 

The Older Parian group consists of a great variety of sandstones, fine or coarse grained and 

usually highly indurated, which properly seems referable to the extensive diffusion of siliceous 

cementing material; of shales of a dark color, characterized by flakes of silvery white mica; 

and of strata composed of an argillaceous base, with small equivalents of carbonate of lime and 

free silica. * * * 

Limestones are rare, do not exceed 10 to 20 feet in thickness, are extremely compact, and 

their fossils usually partially or entirely transformed into highly crystalline spar. * * * 

Very few fossils were collected in this formation, and those obtained were from a single 

limestone at Point a Pierre, but none of them offering any characters sufficiently precise for 

defining the geological position. Some fossil remains procured from the same series at Cumana, 

in Venezuela, fortunately present a more positive aspect and are referable to the later secondary 

period. It is highly probable that these strata are of similar age to the upper secondary deposits 

of New Grenada, which are attributed by Von Buch and D'Qrbigny to the N eocomian or Lower 

Cretaceous horizon. 

Disturbances are everywhere characteristic, the angle of dip is almost invariably high, and 

the strata are often vertical; but buried as the formation usually is in the center of the densest 

forests, it is extremely difficult to obtain sections adapted for resolving the details of position. 

These disturbances are by no means referable to a single series, since the consolidation, perhaps 

rapid, and the first elevation must have transpired before the newer Parian deposits were 

formed, and consequently anterior to the Miocene epoch. -mterior movements, possibly 

repeated at intervals, affected both groups nearly equally, since in N aparima and the southern 

districts the Tertiary members are found at high angles reposing apparently conformably on 

the subjacent Older Parian. 

E. H. Cunningham-Craig, 200 Government geologist of Trinidad, made fourteen 

brief reports to the legislative council between 1904 and 1907 inclusive and 

described local details, especially of the oil fields in Tertiary strata. 
LOWER CRETACEOUS. 585 

C 17, D 16. HONDURAS AND COSTA RICA. 

Sapper 696a describes certain strata of southern Central America as the Metapan 

terrane, and says: 

Under this name I included in describing the geologic formations of Guatemala a system 

of clays, marls, sandstones, and conglomerates with included limestone beds which conformably underlie the Cretaceous limestone. In Honduras the same formations occur with 

the same lithologic character and they have great extent in all the northern and middle districts; 

that they belong to the lower Cretaceous is shown by many fossils which have courteously 

been described by Dr. Joh. Bohm of Berlin. 

In a footnote Sapper gives the following list of fossils as having been determined 

by Bohm: 

From Carizal: 

Glauconia cfr. picteti Coqu. 

Between Charizal and Cuevas: 

Protocardia cuevasensis n. sp. 

P. ventrosa n. sp. 

Lima wacoensis F. Roem. 

From Cuevas: 

Lima wacoensis F. Roem. 

Area elongatior n. sp. 

Protocardia cuevasensis n. sp. 

The most important places at which fossils have been found occur in the interbedded 

limestone strata near Selila, near N eambar, between Comayagua and Potrero, as well as between 

Espinas and Esquias. The fossils are, however, not sufficiently numerous and not sufficiently 

widely distributed to give definite data as to the age of individual beds, and as the petrographic character of the Meta pan terrane is often extraordinarily similar to that of the Upper 

Triassic Tegucigalpa formation, I have not been able to determine with certainty in regard to 

the occurrence in the departments of Tegucigalpa and Olancho whether we have to deal with the 

Metapan or the Tegucigalpa terrane. 

The Metapan terrane is conformably overlain by a moderate thickness of Upper Cretaceous 

["Meso-Cretaceous," Comanche] limestones, which in Honduras often form the mountain 

summits. * * * The limestones near the western boundary of the Republic of Honduras 

near Copan, are characterized by well-preserved Rudistes, and thus belong to the Upper Cretaceous ["Meso-Cretaceous," Comanche]. The correlation of the limestones which occur in the 

departments of Santa Barbara, Comayagua, Y oro, and Olancho and have a thickness of several 

hundred meters with the Upper Cretaceous depends simply on the fact that they lie conformably 

upon the Metapan terrane. 

Cretaceous limestones have not been certainly identified in the Republic of Nicaragua, but 

it seems to me quite possible that the limestones of the middle course of the Rio Coco may be 

so correlated. 

Sapper then goes on to mtntion occurrences in Costa Rica and, quoting R. T. 

Hill, describes a dark-blue massive limestone which ontcrops in steeply dipping 

beds and is in large part composed of Rudistes and Inoceramus. He mentions 

several other localities in Costa Rica at which rocks of probable Cretaceous age 

occur. 

D-E 15-16. GUATEMALA AND CHIAPAS. 

The Mesozoic formations of Guatemala are described by Sapper, 695a who says: 

The Mesozoic formations occupy very extensive areas in Alta Verapaz (Guatemala), but 

the strata are nevertheless very monotonous and consist everywhere of limestones and dolomites, together with conglomerates and breccias of the same rocks, so that it is impossible to 

distinguish different horizons by lithologic differences. 
586 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

It is true that in the south the limestones and dolomites are in general of darker-gray to 

black tones and are thus distinguished from those of the north, which exhibit clear, mostly 

yellowish color values. The conglomerates often contain interbedded layers which are colored 

red by iron oxide. The predominance of brighter colors in the limestones of the north does not, 

however, prevent the frequent occurrence of limestones and especially of dolomites of darkgray tones in that region; but it has not been possible to show that there was any difFerence in 

age between the lighter and darker limestones. 

The paleontological evidences also fail to bring complete satisfaction, for only the lightcolored limestones contain fossils, such as the remarkable Barettia, and in other localities 

Sphrerulites or remains of Radiolites, which have not yet been accurately .determined. In many 

places there are organic breccias of mussels and snail shells, which, however, are not accurately 

determinable. Yet a:s they occur with well-recognizable traces of Rudistes they evidently 

belong to the Upper [ 1] Cretaceous.[a] I find remains of Rudistes as far south as the crest of 

the Chicoj Range, but thence southward the limestones and dolomites of the Coban terrane 

have failed to yield a trace of fossils. They seem to be older than the Upper Cretaceous limestone of the north. The boundaries of the Coban limestone with the Carboniferous limestones 

and dolomites on the south are as difficult to fix as are those of the Cretaceous in the north, and 

for that reason they are shown upon the map only by dotted lines. 

Sapper estimates the thickness of the Cretaceous at about 800 meters. 

Bose 88 in 1905 described at some length the Lower Cretaceous (Eo- and MesoCretaceous as he described the beds) of Chiapas and expressed the opinion that the 

Neo-Cretaceous (Upper Cretaceous) was lacking in that province. He says: 

The Eo-Cretaceous of Chiapas is composed of argillaceous, sandy, slate-colored strata, red 

beds, slate-colored limestones, and sandstones in thick beds. These strata occur beneath the 

limestones with Rudistes and in the south in contact with the Todos Santos terrane. The 

limit between the basal Cretaceous and the Todos Santos has not been carefully studied. The 

Lower Cretaceous in the south is everywhere followed by Cretaceous limestones with Rudistes. 

Moreover, it occurs in the basin of Chiapas, where it is laid bare by erosion. The thickness of 

this formation is about 300 or 400 meters. It is followed conformably by Cretaceous with 

Rudistes, as may be seen to the south and west of Tuxtla, Gutierrez, and Chiapa. Sapper 

classed these beds as Upper Cretaceous and said that they rest upon the limestone with Rudistes. 

This is not certain. * * * The few fossils which I have been able to examine indicate rather an 

Eo-Cretaceous than aN eo-Cretaceous age. It should be stated that the greater .part of the species 

which Sapper cites are contained in the private collection of the former director of the Instituto 

Geologico, which was not accessible to me. I have from those beds only an Isastrrea sp. nov. 

very like an Isastrrea of the Eo-Cretaceous of San Juan Raya, two examples of Nerineopsis 

goyzuet::e Aguilera, n. gen., n. sp., and some poorly preserved corals. It is possible that to this 

division belong also certain gray and brown strata with masses of limestone which occur near 

Cancuc, at the northern base of the Mesa Central. * * * It is quite probable that these 

strata correspond to the upper part of the Metapan terrane, which is found in the southern part 

of Guatemala, in western Honduras, and in the northwest of San Salvador and which consists 

also of marls, sandstones, and argillaceous rocks and conforJUably underlies the limestones 

with Rudistes. 

Bose then goes on to describe the Cretaceous limestones with Rudistes ("MesoCretaceous '') and says : 

This division is much the most important in Chiapas. * * * It consists of limestones 

and dolomites which generally occur in quite thick beds and only occasionally as intercalated 

a Probably Meso-Cretaceous of the Mexican Survey or Comanche series of the United States Geological Survey.-

T. W. Stanton, comment on manuscript. See also citations from Bose and Aguilera, beyond. 
LOWER CRETACEOUS. 587 

lenses. Occasionally beds of limestone of brecciated structure are found. In the lower part 

there sometimes occur beds of limestone with chert concretions, but the upper part consists 

generally only of gray limestone with interbedded dolomite. It may be said that these strata 

everywhere contain Rudistes, e~pecially radiolites. 

Bose then cites a number of localities. In regard to the Neo-Cretaceous (Upper 

Cretaceous), he says that the strata of Tuxtla, Gutierrez, and Chiapa, which Sapper 

took for Neo-Cretaceous, in reality belong to the Eo-Cretaceous; that he himself 

has never observed strata which might with certainty be assigned to the NeoCretaceous; but that possibly the dolomites and limestones in the extreme north of 

Chiapas represent a horizon of Upper Cretaceous. 

E 14. STATE OF VERA CRUZ, EASTERN SLOPE OF THE :MEXICAN PLATEAU. 

In the vicinity of Orizaba Bose 87 made a special study of a Cretaceous section 

which he divided into three parts, to each of which he gave a locality name. His 

account may be summarized as follows: 

In the region which we are to describe and which includes the environs of the Rio Metlac 

and Boca del Monte branch of the Veracruz-Mexico Railway the only sedimentary formations 

that occur belong to the Cretaceous system. They have been divided into three parts, which 

may be distinguished partly by paleontologic criteria and partly by lithologic differences. The 

formations are, in succession from above downward: (1) Escamela limestones; (2) Maltrata 

limestones; (3) Necoxtla slates. * * * 

The greater part of this division [the Necoxtla slates] consists of argillaceous slates which 

are yellowish, gray, and reddish, with the luster of silk, and which include not infrequently 

segregations of pyrite crystals. The slates also contain in some places small amounts of mica. 

They are very fissile. In the upper part of the slates one may observe an enrichment in lime 

and the slates are often arenaceous and sometimes merge into a greenish sandstone which 

contains a large proportion of lime and in some places is almost entirely composed of calcareous 

fragments. 

The Maltrata limestones constitute an important division, which is often of great thickness. 

The greater part is composed of limestones in thin beds, is without fossils, and of a clear darkgray or black color. The limestones contain numerous segregations of flint in the form of 

lenses. In the upper portion the flint occurs in the form of nodules and irregular bodies. In 

the lower part of the limestones there occur in many places intercalated argillaceous slates 

which are yellowish and lustrous like silk, but these never form heavy beds. In the upper part 

toward the boundary with the Escamela limestones, there occur gray limestones and dolomites 

in heavy beds in which the stratification is scarcely recognizable. Above these follow dark 

compact limestones ;which represent the passage to the Escamela limestones and which may 

better be considered a part of the latter. In some places there occur above the dolomites flinty 

limestones, and in that case the line between them and the Escamela limestones is sufficiently 

well marked. 

The Escamela limestones are composed of a clear gray to a dark-gray limestone, in some 

places but slightly stratified and elsewhere in clearly distinct beds.· Cherts occur only in the 

lower portion. There are no intercalations of slates or marls. The limestones resemble in their 

characters very often the Cretaceous limestones of southern Italy. They are petrographically 

very uniform and may be r~cognized with ease. 
588 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Bose's description includes lists of fossils and a study of the relations of the 

Cretaceous of Orizaba with that of Texas and northern Mexico and that of Europe. 

His correlation table is translated as follows: 

District of Orizaba and Tehuacan; formations of southern Mexico. 

Escamela limestones, 600 meters. 

Maltrata limestones, 500-600 

meters. 

Texas and northern Mexico. 

---·---· -·-~-----

~ I' Washita division .............. _ Turonian. () . ~ [l ~-~ 

~ ill I Fredericksburg division .. _.... Cenomanian. 

----7-----------r--·-----.----------(?) .................. ------------------·-----------

N ecoxtla slates, thickness not 

determined. A ptien-Urgonian. · Trinity division. 

---------·--1 ---·-------·-·---·-----------· 

Zapotitlanslates and sandstoneo. 1--------------- · .. (?).----------------- Upper Neocomian. 

Black calcareous slates. Middle and lower X eoccmian. 

Upper Jurassic and older formations. 

Upper Jurassic. 

Bose's paper has been reviewed by Stanton, 780 who has also contributed the 

following notes in regard to the relations of the limestones in the vicinity of Orizaba: 

The faunas of the two limestones indicate correlation with the Comanche series, and the 

underlying slates, though unfossiliferous, are correlated by lithology and stratigraphic position 

with the Lower Cretaceous of Zapotitlan, in Puebla. 

The section at Zapotitlan and San Juan Raya has been described by Aguilera (Guide 

geologique au Mexique), who states that the Escamela and Maltrata limestones, which he refers 

to the Cenomanian, are represented here by a single unfossiliferous limestone called the Cipiapa 

division. The underlying Eo-Cretaceous includes the San Juan Raya and Zapotitlan divisions, 

which together are correlated by their faunas with the European Lower Cretaceous horizon from 

the upper Barremian to the Aptien, inclusive. 

E 15. ISTHMUS OF TEHUANTEPEC. 

Bose published for the Tenth International Congress an account of the geology 

of the Isthmus of Tehuantepec. He said in part: 90a 

Before commencing the description of the excursion in the isthmus, we will summarily 

describe the geology of the terranes which extend from east to west in this region. West of the 

isthmus there is the mountain chain of Mexico, and on the left the chain of Central America. 

The former consists of the following formations: At the base there is a series of gneisses and 

mica schists, with ancient diorites and granites., Upon these rocks there rests in general the 

Cretaceous, but there are also islands of Rhretic, Liassic, and Upper Jurassic. The series is 

rarely complete, and the Paleozoic is always absent. The Cretaceous is composed of the lower 

and middle Cretaceous and covers probably the larger part of the country. In the north [of 

Mexico as a whole] these are supplemented by the upper Cretaceous. 

From this distribution of the Cretaceous Bose infers an early elevation of 

southern Mexico, to which he attributes the absence of marine Tertiary in the 

high plateaus, and he says further: 

In the plateaus we encountered deposits from extensive lakes which belong in part to the 

Eocene .and Miocene, the Pliocene, or Quaternary. Their age has been determined in many 
LOWER CRETACEOUS. 589 

~ases by means of fossils, both plant remains and vertebrates; in other cases it has been necessary 

to base an opinion upon the presence or absence of modern eruptive rocks in the conglomerate. 

E-H 12-15. MEXICO IN GENERAL. 

Cretaceous rocks, chiefly limestones, have great thickness and wide distribution 

in Mexico and Central America. Two classifications have been applied to them. 

One is that of Hill, who recognized the Comanche series in its characteristic development and also the Upper Cretaceous. The Mexican Survey, on the other hand, 

divides all the strata of the Cretaceous system into three series, which it designates 

as Eo-, Meso-, and Neo-Cretaceous and which are correlated on paleontologic evidence with European divisions. The Eo- and Meso-Cretaceous of this classification corre8pond with the Comanche of Hill's classification, and the Neo-Cretaceous 

is Upper Cretaceous, later than Dakota. Aguilera 9

b refers to the synopsis of the 

geology of Mexico 7 and says: 

We divided the Cretaceous into Lower, Middle, and Upper divisions, which, according to 

the resolutions adopted at the International Geological Congress, should be called respectively 

Eo-Cretaceous, Meso-Cretaceous, and Neo-Cretaceous. In. practice this arrangement has 

proved advantageous, although it has been abandoned elsewhere, as it is here very useful from 

the double point of view of lithology and paleontology. The limit between the Eo-Cretaceous 

and Meso-Cretaceous series should correspond to the bottom of the compact limestones which 

form the mountains of Mexico, where it is impossible for us to separate the Albien from the 

Cenomanien, as the former has not yet been identified by its fossils in Mexico; and the EoCretaceous series thus ends with the Aptien. The Meso-Cretaceous extends from the Albien to 

the Cenomanien inclusive, and the Neo-Cretaceous is composed of the Turonien, Emscherien, 

Aturien, and Danien. 

The Meso-Cretaceous series is very extensively developed throughout the country and 

forms almost all of the limestone mountains of Mexico. It is found from Sonora, Chihuahua, 

and Tamaulipas in the north to Chiapas and Tabasco in the south, and from the Gulf of Mexico 

to the Pacific Ocean. The predominant facies of the Meso-Cretaceous are those of the Rudistes 

and Caprinides. Up to the present time we have not succeeded in clearly separating the Albien 

from the Cenomanien. To the north the series is composed of marly rocks and in certain places 

carries a sufficiently rich fauna. 

The following notes on the stratigraphy and distribution are condensed from 

Aguilera's descriptions, and arranged from south to north. For fossils and European equivalents, the original should be consulted. 

Eo-Cretaceous strata occur as follows: 

In the State of Oaxaca, at Tlaxiaco, the Eo-Cretaceous is represented by calcareous to gray calcareous argillaceous shales and by compact limestones of gray 

and grayish-black colors. 

Near Cualac, in the State of Guerrero, are quartzose sg,ndstones, gray to red 

in color, with grayish and yellowish argillaceous and marly shales. At the base 

are gray sandstones with impressions of plants. Red and ytllowish quartzose 

sandstones and argillaceous schists occur near Tomixlahuaca. 

In the State of Michoacan argillaceous shales of black and grayish colors alternating with yellowish fossiliferous sandstones are found at Cochixtla, and argil..., 

laceous marly shales alternating with calcareous fossiliferous shales at Parota, in 

the district of Coalcoman. 
590 INDEX 'l'O THE STRATIGRAPHY OF NORTH AMERICA. 

In the State of Puebla, at Zapotitlan and San Juan Raya, the terrane consists 

of gray argillaceous rocks, marly gypsiferous yellow shales, calcareous green 

sandstones, marly green sandstones, and varicolored shales. 

In the State of Vera Cruz, at Necoxth, occur argillaceous micaceous reddish 

gray or black shales, with beds of limestone in the upper part but without fossils. 

In San Luis Potosi, at Catorce, there are in the upper part shales and marly 

sandstones and compact limestones. 

In the State of Tamaulipas, at Miquihuana, there are beds of sandy shales and 

limestones which rest upon sand with pebbles of quartz but which are unconformable upon the older Mesozoic strata. According to Hill they closely resemble the 

beds of the Trinity group of Texas but have a different fauna. Felix and Lenk 

believe that these beds represent the littoral facies of their Monopleura beds of 

Tehuacan. 

In the northern part of the State of Zacatecas (at Mazapil, Santa Rosa, Concepcion del Oro, and Canutillo) the Eo-Cretaceous begins with marl and limestone. 

Above these come blui"h limestones and other limestones with large concretions of 

chert, having a thickness of 400 or 500 meters but poor in fossils, &.nd yellowish 

marls containing many forms. These last-named beds may serve as the plane of 

separation between the Eo-Cretaceous and the "Meso-Cretaceous." 

Occurrences of "Meso-Cretaceous" strata are specifically listed by Aguilera 

from the following localities in several States: 

In Chiapas and Guatemala there are limestones and dolomites, in general in 

thick beds but in some places occurring in thin beds. Some of the layers present a 

brecciated structure. In the lower part the limestones include concretions and 

nodules of chert; in the upper part they inclose intercalations of dolomite. These 

limestones form an extensive belt which runs through the center of the State of 

Chiapas, passes on to Guatemala, and ends in the Gulf of Honduras. 

In the State of Michoacan, at Coalcoman, are compact black and gray limestones. At Aguililla occur compact gray and blackish limestones with chert, but 

without fossils. At Huetamo are compact limestones and calcareous shales. 

In the State of Mexico, at Zumpahuacan, in the Sierra de San Gaspar, are compact gray yellowish-white limestones. In Morelos the horizon is represented at 

Ayala and Yon tepee. 

In Jalisco fossils of the "Meso-Cretaceous" have been obtained at Saistra, Sierra 

de Tapalpa, and at the hacienda of Huilcalapa, Canton de Zapotitlan. 

In the State of Vera Cruz the limestones of Orizaba may be divided, from 

above downward, into the Escamela limestones, which are gray and occur in thick 

beds with a facies of Rudistes and Chamides, and the Maltrata limestones, with 

blackish cherts and without fossils. 

In the State of Queretaro, at Cadereyta, occur compact gray fetid limestones, 

limestones with chert, and calcareous and argillaceous shales. 

In the State of Hidalgo, at Zimapan, are compact gray fetid limestones with 

calcareous shales. 

In the State of Zacatecas, at Mazapil, Santa Rosa, Concepcion del Dro, Fresnillo, Comacho, and N oria de Angeles, occurs a pelagic facies. It consists of lime-
LOWER CRETACEOUS. 591 

stones with black chert, having a thickness of 400 to 500 meters or more. In the 

vicinity of Colima there are limestones and shales. On the eastern slope of the 

Sierra de Tamaulipas, near Victoria, occur limestones and shales. 

In the State of Chihuahua the transition stage to the Cenomanian occurs at 

several places in the Cerro Muleros, near Ciudad Juarez, with argillaceous sandstones and shales, and at Encantada, near Placeres de Guadalupe, where there are 

shaly limestones and marly schists. This stage corresponds to the Fredericksburg 

group, or some portion of it, of the Lower Cretaceous of the United States. At 

Arivechi, in the State of Sonora, there are calcareous and marly shales. 

The Cenomanian is well developed throughout in the States of Chihuahua 

(Cerro de Muleros) and Coahuila (Hacienda de Vacas, Rancho de San Diego, Santa 

Eulalia, Javal, etc.), consisting of limestones and gray compact shales with a littoral 

facies and a rich fauna. Characteristic fossils occur in the limestones and shales of 

the Sierra Mojada. 

For the N eo-Cretaceous (Upper Cretaceous) see Chapter XV (p. 644). 

F 14. SAN LUIS POTOSI. 

In examining the section along the railway line between San Luis Potosi and 

Tampico, Bose ~ studied a Cretaceous series which is distinguished by a peculiar 

facies that is not represented as a whole elsewhere in North America, except 

perhaps in Jamaica. He has described the fauna and correlation in detail. The 

following statement regarding the stratigraphy is extracted from his work: 

The strata which contained the fauna described in this work constitute a complete whole 

to which we give the local name Cardenas division, for the facies is very different from that of 

any other Cretaceous formation in America. It has a sufficiently great thickness, which may 

be estimated approximately at 600 meters; this v,mount is naturally not exact, as the strata 

have been greatly folded, and it has not been possible to establish with certainty the existence 

of any younger beds. Lithologically, the Cardenas division is composed of various formations. 

Above the heavy-bedded limestones which form the canyon of Tamocopo, in the upper portion 

of which we have not been able to find determinable fossils, there occur in the vicinity of Canoas 

station arenaceous limestones, which alternate with marls and with clay and marly slates. 

Above these slates occur heavy beds of limestone, which are in part marly, and still higher there 

again appear marly and arenaceous slates, which pass gradually into heavy-bedded limestones. 

These are poor in fossils and are followed at first by yellow clay slates without fossils, upon which 

rest marly yellow slates with intercalations of sands~ones of the same color, which are fossiliferous. The top of the division is composed of marls of a grayish-yellow color, with some beds of 

limestone. The beds are very strongly folded and their order of succession can not be made out. 

Stanton a states: 

Near the eastern margin of the Mexican plateau, between San Luis Potosi and Tampico, 

there is a thick Cretaceous ·section which evidently includes the equivalent of a large part of the 

Comanche series as well as some Upper Cretaceous. A part of the latter which shows a faunal 

and lithologic facies not known elsewhere in North America has been described by Bose under 

the name Cardenas division and referred to the lower Turonian. Its thickness is estimated at 

600 meters. The presence of Exogyra costata and Gryphxa vesicularis suggests its approximate 

correlation with the Ripley of the Southern States, but the rest of the fauna is distinct and in 

its general character more nearly resembles that of Jamaica and of the European Gosan beds. 

a Personal communication. 
592 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

G 13-14. SIERRA DE MAZAPIL, ZACATECAS. 

Burckhardt 109a thus describes the Eo-Cretaceous and "Meso-Cretaceous" of 

the northern part of Zacatecas: 

The Cretaceous limestones that overlie the shaly formations which we have just described 

represent the- complete series from the upper limit of the Jurassic to the Upper Cretaceous. 

Near the middle of their thickness these limestones are divided into two parts by a very fossiliferous bed of marl known as the "Parahoplites bed." Furthermore, there is at the base of the 

sequence a second marly bed, which is also rich in fossils, the "Holcostephanus bed." By 

means of these fossiliferous marls, it is possible to establish four subdivisions of the Lower and 

}\fiddle Cretaceous of Mazapil. The lower marls, which contain Holcostephanus, are rather thin 

and separated from the Jurassic by thin strata of gray limestone. 

These marls are. generally yellowish and contain many nodules of iron oxide. They alternate with beds of grayish or brownish limestone. Fossils are very numerous.a * * * 

Above the marls with Holcostephanus there follow limestones which have a thickness of 

400 to 500 meters and which are generally markedly distinguished by intercalations of chert. 

These cherts, which are usually brownish at the surface and bluish in the interior, are commonly 

of very irregular forms, and never assume a notably horizontal extent, as is the case with the 

layers of chert in the Middle Cretaceous. It is very difficult to extract any fossils from the rock, 

and the only fairly good specimen which I have found is a fragment of Holcodiscus. * * * 

Between the limestones which have just been described and those of the Middle Cretaceous, 

there occurs an argillaceous terrane, which may readily be recognized throughout the Sierra de 

Santa Rosa. * * * The beds are not thick, but very characteristic-marls and marly limestones• of a bright-yellow color, alternating with compact limestones which are grayish, bluish, 

or slightly brownish. They everywhere contain many fossils. a * * * 

The Middle Cretaceous is represented by a very thick series of grayish limestones, which are 

generally well stratified and alternate with layers of black chert. These limestones attain a 

thickness of 400 to 500 .:m.eters and are easy to recognize, as there is no other division of the 

Jurassic or Cretaceous of Mazapil which offers so great a thickness of well-stratified limestones 

in alternation with such regular beds and lenses of black chert. The intercalations of chert have 

almost always great extent. They are strata rather than lenses. The rocks are not poor in 

fossils. On the contrary, the beds abound in open ammonites, generally rather slender, belonging 

to the genera Hamites, Crioceras, Ancyloceras, and probably Hamulina. But these remains 

are not specifically determinable. 

Burckhardt's table is given in Chapter XIII (pp. 552-553). 

H 12. SOUTHEASTERN ARIZONA AND SONORA. 

In the Bisbee district of Arizona Comanche strata overlap on Paleozoic, according to Ransome, 658d who gives the following section: 

Generalized section of the Cretaceous rocks of the Bisbee' quadrangle, Arizona. 

00 : Cintura formation, 1,800 feet plus un- .;!:; . known thickness, removed by erosion. 

~ I_____ ---------·- ..c: C) 

~ 

"' § 

l\1 ural lirilestone, 650 feeL 

2. 

0:. Morita formation, 1~800 feeL 

8 M ------ -

Glance conglomerate, 2f:) to ~00 feet. 

Great unconformity. 

Red nodular shales with cross-bedded, buff, tawny, and red sandstones. A few beds of impure limestone near base. 'Unconformably overlain by fluviatile Quaternary deposits . 

Thick-bedded, hard, gray, fossiliferous limestone. 

Thin-bedded, arenaceous foBsiliferous limestones. 

Buff, tawny, and red sandstones and dark-red shales, with an occasional thm bed of.impure limestone near .top. 

I 

Bedded conglomerate ~ith rather angular pebbles, chiefly schist 

and limestone. Rests on irregular surface produced by erosion. 

i . 

a For list see the work cited.-B. W. 
LOWER CRETACEOUS. 593 

Ransome describes the four formations in detail. Fossils were obtained 

chiefly from the Mural limestone and Stanton reported on them as follows: 

The collection consists of a considerable number of small lots of fossils, with seldom more 

than three or four species from one locality, and it includes a number of undescribed forms. 

The known species that are recognized, however, are sufficient to prove that only the fauna of 

the lower Cretaceous, or Comanche series, is represented in the collection. The identified 

species all occur in Texas, indicating that the waters in which the Arizona deposits were laid 

down were directly connected with the Comanche sea of Texas and Mexico, which probably 

did not extend much farther west than the Bisbee area. 

In the Texan region three principal divisions are recognized in the Comanche seriesTrinity, Fredericksburg, and Washita. All of the identified species in this collection occur in 

the Glen Rose beds of the lowest or Trinity division and only one of them (Lunatia pedernalis) 

is known to pass up into the lower members of the Fredericksburg division. 

A list of species referable to the Glen Rose limestone of Texas follows. 

Dumble 295 cites Aguilera's description of the Cretaceou~ in Mexico and gives 

accounts of the strata west of Casita, near Zubiate, Hermosillo, and particularly 

near Cabullona, northeast of La Morita. He says: 

By far the best exposure observed is that near Cabullona, northeast of La Morita. Here 

appears a great series of Cretaceous rocks, probably including strata belonging to both the 

Lower and Middle divisions of the Mexican geologists, with other beds of which I find no description at all. 

A section made about 2 miles from the Cabullona ranch house gave the following: 

1. Interbedded sands and clays of varied colors. The materials are altered in places 

by metamorphism, some being quartzitic, and some of the clays hardened and greasy. There 

are some intercalated andesitic beds and dikes of porphyry. The top was not seen, 1,000 feet. 

2. Massive limestones; light-colored semimarbles at the top, followed by brown and gray 

limestone. All the beds are very fossiliferous, but the fossils appear only as cherty protuberances on weathered surfaces and in many cases are so broken as to be scarcely distinguishable. 

Among the forms certainly recognized were a small Gryphrea and a Trigonia (like T. emoryi). 

The middle beds carry flints in considerable quantities, and the Gryphrea occurs in the basal 

portion in great numbers, 500 feet. 

3. A series of interbedded marls and marly limestones, with large numbers of a very heavy 

oyster, Trigonia, Cardita, and other forms, 900 feet. 

4. Quartzites, sands and interbedded clays or marls; bottom not seen, 400 feet. 

Except for their metamorphosed condition, the uppermost beds of this section resemble 

very closely the "coal series" of the section made at Eagle Pass, Texas, and, like those beds, 

they are coal-bearing. They cover quite an extensive area in this region but are badly cut up 

and disturbed by eruptive intrusions. These beds comprise alternations· of sands and clays 

with ferruginous concretions (some of which are of large size), considerable quantities of gypsum, 

and some petrified wood. The sandstones vary from fine-grained to grit, and the clays from 

those nearly pure to those with a large admixture of sand. The metamorphism directly or 

indirectly due to the volcanic extravasations which accompanied and followed the deposition 

of these beds has produced, in addition to its indurating effects, bright-purple and greenish 

colors in some places, so that some of the beds closely simulate those of the tuff itself. The 

beds are somewhat faulted and broken. Our work did not extend far enough to the north to 

reach the top of the beds, which are certainly more than 1,000 feet in thickness. The only 

fossils found were specimens of a small square-beaked oyster, which occurred just below the 

coal. 

There are two beds of coal, both highly altered. The lower is quite graphitic, and the 

upper, while retaining the struct~re of bituminous coal, is an anthracite in its composition. 

48011°--12----38 
594 INDEX TO THE STRATIGRAPHY OF NORTH Al\1ERICA. 

The massive limestones underlie these sands and clays, and, as far as could be seen, without 

any unconformability. These limestones seem to correspond very well with Aguilera's description 

of the Middle Cretaceous. The Gryph:Ba which they carry in such abundance resembles very 

closely the variety found at the base of the Fredericksburg beds, in northern Coahuila. 

H 13. QUITMAN MOUNTAINS, TRANS-PECOS TEXAS. 

The Quitman Range crosses the thirty-first parallel near longitude 105° 25' 

and extends northward to Malone Mountain and southward to the Rio Grande. 

The development of the Comanche series in the southern portion of the range is thus 

described by Stanton ma in Cragin's report on Malone Mountain: 

Cretaceous rocks have a great development in this region and represent the three main 

divisions of the Comanche series-the Trinity, Fredericksburg, and Washita-as well as a part 

of the Upper Cretaceous. Lithologically the section differs greatly from that of central Texas, 

where the Comanche series has been most studied, and there are also considerable differences 

in the vertical range of some of the common species, so that it is impracticable to recognize 

many of the minor formations and horizons that have been studied. The general faunal succession is the same in both regions, and it is usually not difficult to classify the beds by means 

of the fossils as Trinity, Fredericksburg, or Washita, though it was difficult and' sometimes 

impossible to assign each exposure to its exact position in the general section, because many 

of them are relatively small and isolated and the structure is complicated by folds, faults, and 

igneous intrusions. The most complete sections are to be found in the Quitman Mountains, 

especially toward the southern end and in the lower hills farther south on the Rio Grande, in 

the southern extension of the same line of uplift. 

The description of the Quitman Range comprises notes on structure and on 

igneous intrusions, as well as on stratigraphy, and the more complete section near 

the Rio Grande is given as follows: 

Still farther south, near the Rio Grande, the upper part of the section is much more complete and more simple, furnishing the key to the sections already discussed, which are parallel 

with it across the same line of uplift. The eastern end of the section is about 1 mile north of 

the Rio Grande in the first hills west of the broad valley of Quitman Arroyo. Here the beds 

are sharply folded and a prominent ridge shows an anticline consisting of argillaceous limestone 

belonging to the Washita division. 

The western limb of the anticline clips 70° to 80° W., and the exposure is as follows: 

Section in hills just west of Quitman Arroyo, about 1 mile north of the Rio Grande. 

Feet. 

1. Argillaceous limestone, weathering in nodular form, with bands of harder limestone........ 200 

2. More massive limestone, much seamed and fissured....................................... 30 

3. Dark, fissile shale, with occasional bands of impure brown limestone, underlying a valley 

about 1 mile wide. Dips at first steep to the west, becoming variable and much less 

toward the middle of the valley and again steep to the west on the west side of the valley. 

Inoceramuslabiatus and a few other Upper Cretaceous fossils we:e found west of the middle 

of the valley; thickness apparently several thousand feet. 

4. Massive limestone, probably same as No.2 ............................ _.................. 30 

5. Argillaceous limestone with some bands of clay and sandstone; fossils: Nodosaria texana, 

Enallaster texanus, Neithea texana, Exogyra arietina, E. drakei var., Plicatula incongrua, 

and other Washita forms .......................................................... _.. 300 

6. Heavy-bedded limestone (40 feet) forming a cliff, followed by argillaceous nodular limestone 

(30 feet), which yielded Enallaster texanus, Gryph::ea corrugata, Lima wacoensis, Neithea 

texana, and Schlambachia vespertina ...................... _ .. _. _ .. _. _. _. _. _. _. _. _. _. _.. 70 

7. Similar limestones with dip not less than 45 ° westward ........... : .......... , ......... _ . . 300 

' 
LOWER CRETACEOUS. 

8. MorA argillaceous light-gray limestone, interstratified with dark clay shales; one of the 

limestone bands yielded Epiaster whitei, Terebratula (Kingena) wacoensis, Gryph!1'a 1Dash1:taFeet. 

ensis (?), Plicatula incongrua, and Schlcenbachia vespertina, and another band farther west 

yielded Epiaster uhitei, Schlcenbachia acutocarinata, S. serratescens, and Hamitesfremonti.... 300 

9. Dark clays with brownish calcareous bands; Exogyra texana abundant...................... 50 

10. Covered. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 

11. Limestone, very heavy bedded above, with increasing bands of argillaceous limestone below; 

Requienia and a small conical Foraminifera abundant; Exogyra texana also occurs........ :>00 

12. Shales, limestones, and bands of brown sandstone, not well exposed...................... 250 

13. Argillaceous limestone, with some harder bands containing "Caprina" and RPqnienia...... 75 

14. Generally more massive limestone with some bands of brown sandstone. Also l'ontains 

'' Caprina,'' Ostrea, etc ............................... __ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350 

15. Quartzitic sandstone with thinner bands of clay shale and impnn> limestone, dipping st:eeply 

westward .............. _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400 

16. Hard, blue limestone, full of Orbitolina te.wna ............ _____ ......................... 60 

17. Sandstone and impure limestone with some clay............ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 

18. Sandstones and clays ..................................... _.. . . . . . . . . . . . . . . . . . . . . . . . . . . 250 

19. Thin-bedded passing into massive limestone, full of Orbitol?:na texana; at ]past................ 300 

595 

The steep western surface of No. 19 forms the eastern wall of the canyon of tho Rio Grande 

at this point. 

So far there has been no apparent serious break in the section, but the beds now become 

complexly faulted and folded. A short distance north No. 19 is cut off by a fault, and on the 

west, across the river, the same bed seems to be repeated in several postures. 

It is evident that the eastern portion of the section crosses a syncline, so that in passing 

from No. 1 to No.5 the same beds are all crossed twice. In the rest of the section, while there 

may be some repetition of beds due to small faults, there are no anticlines nor synclines, and 

the fossils show that in general the beds are successively older toward the west. No.3 is Upper 

Cretaceous, of the age of the Fort Benton; Nos. 4 to 8 are Washita; Nos. 9 to 14, and probably 

15, are Fredericksburg; and Nos. 16 to 19 belong to the Trinity. As the dips are all steep to 

the west it follows that all the beds from No. 4 to No. 19, inclusive, are overturned. It will 

be seen also that the succession of rocks and fossils is similar to that found on the east slope 

of the mountains near Quitman Canyon, and that there is no place for the great sandstone 

series of the "Mountain bed" within the Washita division. It must be older than the Orbitolina 

limestone. 

H 13. CHISOS REGION, TEXAS. 

For the region lying in the great bend of the Rio Grande in Brewster County, 

Tex., the report prepared by Udden in 1905 may be consulted. He sums up as 

follows: 819b 

It was not attempted to make out the succession of separate divisions in the Comanche 

series, for this would have required much more time than was at our disposal, but it may nevertheless be worth the while to sum up the observations made bearing on this subject. 

1. The base of the series consists of sandy or clayey beds containing calcareous material 

also, weathering rather easily. At Cienega Mountain these strata have a thickness of about 150 

feet. 

2. At about 150 feet above the base there is a conglomerate or a pebbly sandstone measuring 

some 20 feet. These two members, and very likely a part of the succeeding beds above, are 

absent at Altuda, where they probably never were laid down, owing to an overlap. 

3. At an unknown distance above this conglomerate there are some dark ledges of very 

compact limestone interbedded with some shaly seams, and these are followed upward by 

several hundred feet of heavy-bedded limestones of lighter color. These lowest three divisions 

arc equivalents of the Presidio beds in the Shafter section. 

4. Then follow 200 or 300 feet of more thin-bedded and less pure limestones, which weather 

more easily and contain a fauna resembling that found in the Shafter beds. 
596 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

5. Above this there are several hundred feet of very massive light limestone, which. is clearly 

the equivalent of the Edwards limestone. 

6. The last and highest of the series is a compact limestone only some half a hundred feet 

thick, which is the equivalent of the Buda. It is separated from the massive beds below by 

some 20 feet or more easily weathering ledges which are frequently filled with organic fragments 

and which correspond to the Del Rio clay. 

At Terlingua both the Buda and the Del Rio zones are much heavier than to the east of t4e ' 

Chisos. These formations clearly thin out or entirely disappear in this direction. 

H 13. TEXAS, NEAR EL PASO, AND CHlliUAHUA, MEXICO. 

Near El Paso, Tex., occur strata of Cretaceous age, which represent the Fredericksburg and Washita groups of the Comanche series. They consist of about 700 

feet of limestone, shale, and sandstone of which Stanton and Vaughan 787 gave a 

detailed section. This section is quoted below, with a correction in the relations of 

divisions 8, 9, and 10. As observed in the field and as described in the published 

section these beds were inverted. 

The following is a description of the section beginning with the highest bed: 

Oolurnnar section of Cretaceous near initial rnonurnent of Mexican boundary survey, on west side of 

the Rio Grandefrorn El Paso, Tex. 

Feet. 

8. Hard limestone with the same species of Exogyra in the top.......................... 15 

9. Clay shales, with bands of limestone nodules, containing great numbers of a large Exogyra 40 

10. Sandstone, white, yellow, or brownish, with shale beds .............................. 200± 

7. Sandstone, white or brown....... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30+ 

6. Upper part of the bed, clay shales alternating with brown sandy flags. Brown sandy 

calcareous layers at base. containing Gryphl£a washitaensis Hill and Nodosaria texana 

in great abundance. The G. washitaensis is confined to base; 30 feet above the base, d .S Ostrea subovata; Ostrea quadriplicata Shum. very abundant between 30 and 40 feet; 

~ 40 feet above base zone of Kingena wac~ensis ........ _ ................................ __ .. __ . . 60 :e: .-o 5. Flaggy argillaceous limestone, with shale partings. Layer of sandy flags at base. In 

.-!'! the sandy flags, Cyprimeria. In the limestone bands Schlcenbachia leonensis, Gryphl£a 

~ washitaensis, Protocardia, Trigonia emoryi. The zone of G. washitaens1:s is at the top .. 100 

~ 4. Clay shales, with indurated caleareous bands. No fossils were found .................. 125 

3. Ledges of hard limestone. Fossils not numerous; at the base there is a considerable 

number of an undetermined species of Gryphtea, Gryphl£a tucumcarii, Neithea, and 

Schlcenbachia . ". . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 

2. Alternations of ct~y and soft argillaceous limestone ledges. Fossils: Exogyra texana, 

Gryphl£a tucumcarii, Gryphr£ajorniculata, Schlcenbachia peruviana, two other species of 

Schlcenbachia, and a large N eithea . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 ,:. ~ §11. Argillaceous limestone, in thick ledges, weathering into nodular limestone, the nodules 

~{;:~ surrounded by clay. Fossils: Protocardia texana, Tylostoma pedernalis, Trochus, 

<JJ ~ .!:; Turritella, Exogyra texana, an anchuroid genus, two species of echinoids, Pleuromya 

~ ..... '"0 knowltoni, Requienia, etc.; 11 feet from the top Ostrea subovata ( ?) . . . . . . . . . . . . . . . . . . 79 

* * * * * * * * 

698± 

* 

Taking the fauna of the section as a whole, its essential identity with that of the noted 

Tucumcari region in K ew Mexico and of other localities on the western and northern borders of 

the Lower Cretaceous area is at once apparent. 

The· section studied by Stanton and Vaughan at El Paso occur5 in the Cerro 

de Muleros, which extends into Mexico and has been investigated by Bose,91 who 

presents a different interpretation of the sequence. He says: 

We have elsewhere stated that we differ on several points from the ideas of the authors 

mentioned. The errors of Stanton and Vaughan resulted from the fact that they did not clearly 
LOWER CRETACEOUS. 597 

understand the structure of the locality and consequently counted the same sandstone twice as 

two beds of different ages. At several points where the series of strata is clearly exposed and 

but little disturbed we have been able to observe the true succession. In our excursion we followed in part the road which Stanton and Vaughan followed, and we shall see what led to their 

mistake. 

All of the sedimentary rocks with the exception of the recent conglomerate and sands belong 

to the Cretaceous. Stanton and Vaughan recognized only their lower part, of which they give a 

list of fossils, but their determinations differ in many cases from ours. With reference to this 

subject we would refer the reader to our publications. a Stanton and Vaugh an distinguished in 

this lower part ten horizons which we are obliged to reduce to eight, but these horizons can not 

be classed as real stratigraphic horizons. There are in fact in the lower part only two horizons, 

to which we must also add two higher horizons which may be considered as such. We give a 

summary of the distribution of fossils in the rocks. 

In his monograph on the Cerro de Muleros, which was not published until the 

summer of 1910, Bose 92 says: 

According to my observations the succession of the beds is as follows (from above downward): 

No. 11. Brown sandstones alternating with argillaceous slate or shale, frequently containing Inoceramus labiatus 

Schloth.; llO meters. 

No. 10. Whitish to yellowish sandstone, highly quartzose and fine grained, with satiny argillaceous shale at the base, 

without fossils; 250 meters. 

No.9. White to clear gray limestone with Exogyra ponderosa: 10-20 meters. 

No. 8. Yellowish marls with E. ponderosa, Hemisater calvini Clark, etc.; 10-20 meters. 

No. 7. Red, brown, and black sandstone in heavy beds, with E. ponderosa; 20-100 meters. 

No.6. Slate-colored brownish marls, sandstones, and limestones, with Ostrea quadriplicata; 10-20 meters. 

No. 5. Gray marls with marly shales and beds of limestone with Schlrenbachia trinodosa; 30-50 meters. 

No. 4. Argillaceous shales, marls, and beds of limestone, with Schlrenbachia nodosa; 30-50 meters. 

No.3. Gray limestones in thin-bedded calcareous gray sandstones and brown to yellow marls and black argillaceous· 

shales, with Schlrenbachia cfr. belknapi; 10 meters. 

No.2. Brown marls with beds of limestone and calcareous sandstone with Schlrenbachia bravoensis; 10-20 meters. 

No.1. Hard limestones in thick beds and of a gray color, with Turritella vibrayeana; 20-25 meters. 

Our subdivisions 1 to 7 correspond to the horizons which were numbered 1 to 7 by Stanton 

and Vaughan, 8 and 9 to the horizons 9 and 8 of those authors, since in fact the limestones 

with E. ponderosa are above the marls which carry the same fossil. That which Stanton and 

Vaughan regarded as their horizon No. 10 is in reality the same sandstone as their horizon 

No.7, and the two American authors did not see our subdivisions 10 and 11. We shall see in 

the discussion of the structure why they mistook a recumbent synclinal for a normal succession. 

If they had gone on to the porphyry they probably would not have fallen into this error, since 

one may there see clearly that the beds or the strata with Ostrea q_uadriplicata rest on the 

sandstone No. 7 of our classification, which is the horizon No. 10 of Stanton and Vaughan. 

Richardson 666a studied the occurrences of the Cretaceous near El Paso north of 

the Rio Grande and made some subdivisions. He says: 

The Cretaceous system is represented here by the Fredericksburg and Washita groups 

of the Comanche series. The Trinity group has not been recognized in this area; nor has the 

Upper Cretaceous been found (with the possible exception that a few small areas of shale in the 

city of El Paso are of Upper Cretaceous age), though rocks belonging to both of these ages 

occur not far to the south and west. 

The Fredericksburg is separated into three formations-the Campagrande, the Cox, and 

the Finlay, which are differentiated by their lithologic features. All these contain Fredericksa Bose, Emil, Monografia geol6gica y paleontol6gica del Cerro de Muleros, cerca de Ciudad Juarez, Chih.: Bol. del 

Inst. Geol. de Mexico. No. 25. 
598 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

burg fossils, but the faunas of the individual formations have not been collected with sufficient 

fullness to permit their paleontologic definition. * * * 

The lowermost formation of the Fredericksburg group is composed of calcareous rocks that 

are well exposed in the Finlay Mountains, where, in the central part of the dome, they lie 

unconformably on the Hueco formation. At the base of the Cretaceous section is a limestone 

conglomerate about 25 feet thick composed of rounded pebbles of Carboniferous limestone averaging possibly about 2 inches in diameter. Above this are 350 feet of gray limestone, 

which is generally massive but locally contains nonpersistent, thin-bedded limestone grading 

into shale. * * * 

The Campagrande formation is conformably overlain by the Cox formation. 

The Cox formation consists of massive soft brownish sandstone, some intercalated gray 

limestone, and near the base a red-drab shaly member. The formation averages about 600 feet 

in thickness and is subject to variation in composition, so that no one section is typical. Sandstone predominates and composes probably nearly 500 feet of the formation. It is usually 

fine textured, but there are some coarse beds of no great thickness containing quartz pebbles 

as large as marbles. Locally the sandstone is pitted with rounded iron stains the size of 

buckshot, which seem to be due to the weathering of pyrite nodules. · In places the sandstone is 

cross-bedded. The intercalated limestone and shale are usually thin bedded and are generally 

fossiliferous. The shaly member in the Finlay Mountains is about 100 feet thick. * * * 

The Cox formation * * * is conformably overlain by the Finlay formation, [which] 

consists almost entirely of massive gray nonmagnesian limestone, but locally thin beds of brown 

sandstone are included. The:re are at least 300 feet of the Finlay formation exposed in this 

region, but the top has not been found. * * * 

Rocks of Washita age are present as outlying masses in several localities. The thickness 

of the strata is not great and it has not been found practicable definitely to correlate the 

different exposures. They look much alike, being commonly buff-colored calcareous shale and 

thin-bedded limestone with occasional subordinate sandstone. 

H 14. LLANO-BURNET REGION, TEXAS. 

From his studies in 1910, the results of which are published in folio 183 of the 

Geologic Atlas of the United States, Paige gives the following sections of the LlanoBurnet region of Texas: 

In the Llano-Burnet region only the Frederick::;burg and TriniLy groups of Lhe Lower 

Cretaceous are represented. Although in the Austin quadrangle a to the southeast, the Trinity 

group was subdivided into the Glen Rose and Travis Peak formations, it was found impractical 

for the following reason to make this distinction in the Burnet quadrangle. The Travis Peak 

formation, while a definite lithologic and paleontologic unit in the southeast corner of the 

Burnet quadrangle, loses these characteristics toward the north. This change is due to changes 

in the conditions of sedimentation along a slowly subsiding coast line. Owing to the gradual 

transgression of the sea over the land and the concomitant lowering of the surface which supplied debris for sedimentation, the sediment~ grew finer and more calcareous, the basal beds 

thinner and less conglomeratic, until a condition existed where only nearly pure limestones were 

being deposited along low, gently sloping shores. The following formations hav'e been mapped 

in the Llano-Burnet area: The Edwards limestone; the Comanche Peak limestone, including the 

·walnut clay; and the Trinity formation, including the undifferentiated Travis Peak and Glen 

Rose. The following sections afford examples of the several formations. 

a Hill, R. T., and Vaughan, T. W., Austin folio (No. 76), Geol. Atlas U.S., U.S. Geol. Survey, 1902. 
LOWER CRETACEOUS. 599 

Ilickory Creek section of the Travis Peak formation, beginning at the top of the divide between Ilickory 

and Cow creeks and continuing to the Colorado River level at the mouth of Jlickory Creek, 

Burnet County. a 

:Feet. 

12. Bands o.f conglomerate and calcareous sandstone, alternating with beds of arenac0ous limestone, the arenaceous limestone predominating ....... __ .... _ ..... __ ............ _ .... __ 40 

11. Marly magnesian limestone .................. _ ..... _.................................... 40 

10. Calcareous sand at base, grading upward to a siliceous limestone at the top, barren of fossils.. 55 

9. Yellow calcareous sand, stratified ..................... __ ... ___ .......................... 15 

8. Conglomerate similar in character to No.2, with the exception that the pebbles are smaller 

and more worn, grading into sand below and into calcareous sand above ................ _ 25 

7. Red sand, unconsolidated ................ _ ... _ ........ __ ... _ .................... __ . ___ .. 3 

6. Friable yellow sand ...... _ .. _ ..... __ .... _ ............ __ . __ -..... _ ............. _ ... _._.. 5 

5. Cross-bedded shell breccia, containing many amall rounded grains and pebbles of quartz 

flint and granite sand. Fossils: Trigonia and small bivalves, and Ammonites justinx..... 7 

4. Ostrea beds, magnesian lime cement, fossils en masse...................................... 3 

3. Brecciated grit, composed of worn fragments of oyster shells and shells of other Mollusca, with 

sand and fine pebbles, stratified in false beds ..................................... ,.... 5 

2. Bands of friable bluish shale and calcareous sand, stratified. Fragments of oyster shells are 

common in the calcareous sandstone.................................................. 15 

1. Basal conglomerate of pebbles of limestone, quartz, chert, granite, and schist, well rounded 

in a cement of ferruginous yellow and red gritty sand. Some of the pebbles at the base are 

from 5 to 6 inches in diameter. They decrease in size, however, upward from the base, 

until a false-bedded calcareous shell grit appears at the top............................ 50 

Total thickness of Travis Peak beds ..... _ ........... _ ............................ 263 

Carboniferous: 

Laminated, flaggy Carboniferous sandstones and friable light-blue clay of Carboniferous 

(Coal :Measures) age from the Colorado River level upward to the base of the Trinity conglomerate, the laminated sandstone containing prints of ferns, nearly ............... _ .... 100 

[Total thickness of section] ................. _ ................... _-_ ............... 363 

Section at Post ~Mountain, 1 mile west of Bttrnet.b 

Fredericksburg division: Feet. 

5. Barren Edwards limestone and Comanche Peak limestone ......... _ ................. __ . 95 

4_ \Valnut clay ...... __ .................................................... _ ..... __ .... 10 

105 

Trinity division: 

3_ Impure arenaceous limestone and marl with aragonite crystals ......... _ .. __ ... _........ 25 

2_ Limestone agglomerate of shells with asphaltum ..... _____ . ____ ....... _______________ .. 25 

l. Reddish sandy clays and conglomerate ..... _ .... _ ........... _ ....... _ ... ___ ._._...... 20 

70 

Paleozoic. 

175 

Section of Trinity formation. 

From divide west of Cow Creek on road southwest to bench mark 842. 

Feet. 

Chalky white limestone, weathering porous or honeycombed; fossils .............. _____ ... ___ .. 15 

Similar but not honeycombed; weathers knotty ........ ___ .... ___ ...... _._ ..... ___ ._ .. _. ___ . 20 

Covered slope ............ __ ..... ___ . _____ .. _ .. _ .... __ . _ .. __ ... _ . ___ ..... ___ . _ ... _____ . . . . 40 

Wagon road. 

Buff-weathering limestone; no fossils .................. __ .... _. __ ..... __ ..... ____ ._ ..... _.... 12! 

a Section by J. A. Taff (Hill, R. T., Geography and geology of the Black and Grand prairies, Texas: Twr;nty-first 

Ann. Rept. U. S. Geol. Survey, pt. 7, 1901, p. 140). 

b Hill, R. T., op. cit., p. 136. 
600 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Feet. 

Porous honeycombed limestone; no fossils................................................... 2 

Buff limestone, massive, weathering somewhat nodular; 2 feet at base somewhat shaly......... 7! 

Fine-grained sandy limestone ..... _._ ............................................... _...... 10 

Fine-grained sandy limestone, shaly .............. _ ........... _ ......... _ ......... _ .. _ . . . . . . 1 

Yellowish limestone, more massive and less sandy._ ...................... _ .. _ ..... _ ... __ .. _.. 4 

vVhite clay ..... _ ...................... _ .... __ .... _ ... _ ........ __ ..... _ .... _. _ .. __ ... _ .. __ . 1 

Coarse buff limestone ............... _ ...... __ .. _ ..... __ ... _ .... _ ... _ .......... __ .. __ .... _. 4 

Oyster shells in sandy layer ............... _ .. __ ........ _ .... _ . _ .. _ .......... _ ... __ . . . . . . . . 2 

Massive limestone, weathering yellow ........... _ ...... _ ................... _ ... _ ... _....... 4 

Shaly yellow limestone, nodular and full of oysters .............................. __ .. __ .... _.. 8 

Shaly, with thin limestone layers ................ _ ... _. _ ... _ .. _ .............. _ ..... _ .. __ ... 6 

Hard, porous, dense, buff-weathering limestone ................ _ ..... _ ........ _ ... _ ... __ ... _. 1! 

Oyster-shell breccia ............................... _ ..... _ ...... _ ................ __ .. _ ... _ . . 3 

Clay or sand containing chalky nodules ............ __ ......... _._ ...... _ .......... _ .. __ .. _.. 5 

Chalky layer ....................................................... _ ..... __ ... _ ... _ .. __ ... z 

Clay or sand containing chalky nodules .......... __ ........................ _ ... _ ... __ .. _.... 3 

Hard, dense buff limestone, shaly at bottom ................. _ ...................... _ .... _ .. _ 5 

Nodular limestone, weathering into nodular clay ..... __ ........ _ .......... _ ...... _ .... _. _. _. 8 

Siliceous limestone ....... _ ................... __ . -... _ ... _ ........ _ ..... _ ... _ ... _ ....... _ . . 3 

Oolitic fossiliferous shaly-weathering limestone ........................... _ ...... _ ... _ ....... _ 10 

Coarse reddish limestone ....................... _-_ ......... _ ..... _ ........ _ ... _ ...... _ ... _. 5 

White clayey limestone with shaly weathering .......................... _ ....... _ .. _........ 3 

White sandy honeycombed limestone ......... __ ................. _ ..... _ ... _ .. ,_ .. _ ... __ ... 2 

Sandy and nodular-weathering limestone ............. -..... __ .... _ ......... _ ... _ ...... _ .. _.. 6 

Dense dull-white limestone ...... _._ ..... _.- _ .... -- ..... _ .... _. _ ... _ .... __ .. __ .. __ .. _...... 1 

Nodular-weathering limestone .................. -...... -- .............. __ ................... 10 

Dense brown limestone ...... _ .......... _ ................... _ .... _ ............. _ ... _ ... _.... 1 

Clayey limestone, weathering nodular ......... _ .................... _ ...... _ ....... _ ... _ .. _. 4 

Dense buff limestone, weathering nodular, with calcite films and sand grains .. _ ... _ .. __ .. _.... 10 

Nodular-weathering limestone, possibly conglomerate ...... _ ... _ .......... __ .. __ .. _ ..... _. _.. 7 

Like above, but containing coarser grains of quartz ......... _ ..... _ ......... _ ... _ ... _ ... _.... 16 

Stream at bottom of slope. 

Clays, yellow, honeycombed at base ....................... __ ..... _ .... _ .... _ .. _ ... __ .. _-.·.. 10 

Light-colored limestone, somewhat gritty; makes small bench .................. __ ... _ .. __ .. __ . 5 

Soft layers, covered ............. _ ....................... -.......... -- .... -_ ... -.. _._._ .. _. 5 

Hard limestone ........................................... __ ............... _ ... _ ... _ ... __ . 2 

Alternating hard. and soft beds, clay and marly limestone, not very fossiliferous; makes small 

terraced slopes ............................................................... _ . . . . . . . . . 30 

From top of slope northeast of bench mark 842. 

Sandy limestone; few fossils ...... _. __ .... _. __ ..... _._ ..... _ ..... __ .......... _ ........ _.... 5 

Sandy limestone with many shells ... _ ...... - _- .. - . -.. __ . - _ .... __ .... __ ..... _ .... __ .. _. _. __ . 15 

Covered .................... ___ ...... - - - _ .... - -.... - - - - . ___ - _ ..... -.... __ .. _ . _ .... _ . ___ .. _ 5 

Fine sandy limestone with fossils ..... _. ___ ... ____ .. __ -- .... _____ . ____ .. ___ ... _ .... __ ... __ . 5 

Fine sandy limestone; not many fossils ...... __ .. _---_ .. --_._ .. _. __ .... _ .. _ .. _._. __ .. ___ ... _ 8 

Fine-grained conglomerate, in places shaly .. _. __ .... ___ -.... __ . _ .. ____ .... __ .. _ ..... __ .. __ . 5 

Covered .............•............ _._- __ ._ .... --_.-.----- .... ---_ ... -- .... -- .. _-_ ... ---_... 5 

Conglomerate, weathering nodular .. ____ ...... ___ ._ ... _-- __ .. __ . __ .. ___ ._ .. __ ._. ___ . ____ ... 5 

Covered ................... __ ........ _ ....... - - _ -. -.. -......... _ ..... _ ... - - _ ... _ ... _ .. _ . . . 18 

From bench mark 842 downstream. 

Sandy conglomerate .......................... -....... -- ...... _._ ...... _ .... - __ ............ 10 

Oyster shells ..... _ . _ .... ____ ...... _ .. _ ...... _ ....... _ .. _ .. _____ ... - _ .... _ . . . . . . . . . . . . . . . . 1 

Sandy conglomerate .......... _ .. _ ...... __ ... _ .. _._- .... - __ ...... _ .... _ ..... __ ... _......... 1 

Sand and sandy conglomerate .......... -.-_ .... -_-.- .... -_ .... -- __ .............. -_......... 9! 

Conglomerate and oyster shells .. __ ......... _ ..... _--- .................. _ .. _................. 4 

Covered ............................................. _.................................... 20 

409! 
LOWER CRETACEOUS. 601 

Section of portion of Trinity formation, 2~ miles west of southeast corner of Burnet quadrangle, at 

south edge of quadrangle, from top of hill down to Cow Creek. 

Feet. 

Soft sandy marl containing lamellibranchs................................................... 5 

Covered terrace .............. ___ ............................................ - . - - -....... -. 5 

Buff-weathering, massive, slightly honeycombed limestone containing fragments of shells._._.. 2! 

Sloping terrace of softer marly limestone ........ _.......................................... 7~ 

Steeply sloping surface underlain by nodular gray limestone with 2-inch layer of slightly gritty 

material. ... _._ .......... _______ ._ .. ___ ...... __________ ........ __ ........................ 9 

Buff-weathering sandy limestone .. _____________ -______ . _ . _ ........ __ ....................... . 6 

Light-buff calcareous shale, weathering nodular, containing some fossils ............. _._...... 10 

Sandy calcareous limestone containing numerous fossils .. __ . __ .. _ .................... _ ....... . 5 

Sandy limestone ... _ ... _ ... _.................................... . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 

Covered slope, probably underlain by soft bedded limestone._ ..... ______ ........... _____ ._._ 14 

Sandy limestone __ .. __ .. __ .. _____ ........................................ -. - - - - - - -. . . . . . . . . 1 

Soft, knotty, marly buff limestone ............................................ -.--- ........ . 

Covered gentle slope ........................................... -- ...... -.-.------- ........ . 

Cream-colored limestone, slightly sandy ........... ___ ...................................... . 

Clayey marl; top 1 foot very fossiliferous; 5-inch band of buff limestone 2 feet from top ...... . 

Marly beds with hard layers containing some fossils. __ . __ ......... ______ ........... _______ ._ 

Yellow porous limestone containing shells ........... __ ._ .......... __ ............... _. _ ..... . 

Similar, but more massive ................................................................. . 

Similar, but thin bedded ..... _ .................. _ ......................................... . 

5 

5 

1 

19 

8! 

5~ 

6 

5 

Similar, but shaly ... _____ ... ______ .. _ .. ____ . ___ ... __ . ____ ......... __ ............ ________ . 14 

Solid yellow limestone ....... _ ........................................................... . 

Thin-bedded fossiliferous limestone. __ .......... ___ ................................ _______ .. 

6 

9 

Massive chalky limestone, with fossils .......... ______ ._ ............................ ______ .. 6 

Massive chalky limestone. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 

Shaly limestone, transition from above ............................................ _________ 8 

Fine-grained massive yellow limestone ......... ___________ .. __ ... _________________________ _ 

Calcareous shale._ ...... _ ........ _ ....................................................... . 

Fine-grained gray sandstone, calcareot:s ......... ____ . _. _ .. : ....... __ . _ ..................... . 

Covered slope __ ......................................................................... . 

Conglomerate with many pebbles ...... __ ... __ ._ ........ __ ... __ .......... ________ . ________ _ 

7 

10 

5 

10 

27! 

Total in cliff and side of hilL ____ . ________ ... ___________ ._ ..... _._. _________ . _______ 247 

H-I 14. CENTRAL TEXAS. 

From Hill's detailed monographic discussion of the Cretaceous of Texas 445 are 

taken the following extracts: 

The strata of the Lower Cretaceous, or Comanche series [in central Texas] * * * belong 

to three divisions, as follows, beginning with the lowest: Trinity, Fredericksburg, and Washita. 

The general characteristics of these divisions are as follows: 

The Trinity division is especially marked by strata of friable white packsands, which do 

not occur in the other divisions and which in places constitute nearly the entire rocks of the 

division. In some places, especially south of the Brazos, these sands alternate with marly clays 

and chalky and clastic limestones, the latter being composed of minute shells or fragmental 

particles of shells and sands having a lithologic and paleontologic individuality by which they 

can usually be readily distinguished. All the calcareous strata are white or yellowish and occur 

in numerous persistent alterations of hard and soft strata of various thicknesses. 

The rocks of the Fredericksburg division in the typical area of occurrence are almost 

entirely chalky limestone, initiated by beds of marly clay, which grade into the limestone. 

The rocks of the Washita division include the beds between the top of the Edwards limestone of the Fredericksburg division and the coarse sands of the Woodbine (Dakota). 

The sediments of the Washita division, while generally light in color in their lower half, 

show darker tones and greater ferrugination of rocks toward the top. They are composed 

largely of alternations of marly clays and firmer layers of limestone. The limestones of this 
602 INDEX TO THE STHATIGRAPHY OF NORTH AMERICA. 

division, while slightly resembling others in the series, have a sufficient proportion of grit, and 

sometimes of iron, to make them relatively impure. The beds are successively shallower in 

origin in ascending series. 

In general, rocks of the Trinity division were laid down upon a subsiding bottom of a former 

land surface; rocks of the Fredericksburg division (in this portion of Texas) upon a stationary 

offshore bottom of Trinity sediments; and rocks of the Washita division upon a shallowing 

bottom of Fredericksburg sediments. 

TRINITY DIVISION. 

This division include's the lower or initiatory beds of the Cretaceous formations of the Texas 

region, embracing all the rocks lying below the vY alnut beds of the Fredericksburg division. 

* * * In general these strata consist of sands, clays, marls, and massive limestones (including 

in the latter shell breccias, agglomerates, and chalks), all of which grade imperceptibly into one 

another, both vertically and horizontally, according to their proximity to the shore line against 

which they were deposited. * * * 

Studies of these three areas, the western border, the incised sections of the Grand Prairie, 

and the embed beneath the Black Prairie, show great differences in thickness and composition 

of the rocks of the Trinity division, indicating that they are thinner and more arenaceous along 

the western border region, where they are best exposed, and that they thicken a,pd become 

calcareous to the east, being buried in the region of their greatest development beneath the 

Black and Grand prairies, where a knowledge of their nature can be obtained only by careful 

interpretation of the artesian drillings. * * * As a result of these variations of thickness 

and composition the rocks of the Trinity division along the eastern portion of the general area 

of exposure within the incised valleys of the Edwards Cut Plain present the aspect of several 

well-defined and mappable lithologic units of various kinds of rock, which so coalesce along the 

western border exposures into a general basement formation of sands that they are there usually 

inseparable. 

As a whole these strata of the Trinity division may be subdivided into the following 

conspicuous formations and beds: 

Paluxy formation ............................................................. {~~fne~i::!~-nes. Lower sands. 

Glen Rose formation. 

Travis Peak formation ...... ___ . _ .. ______ . _ . _ . ___ . _ . _ . _ . _ . ____________ . _ .. ____ . {~oe;sg~:~n~:d _ 

Sycamore sands. 

The term Basement sands will be used as the equivalent of any of the above formations 

where they rest upon the underlying Paleozoic floor. The name Antlers sands will be applied to 

the equivalents of all these formations as they coalesce along the western border region north 

of Parker County. 

FREDERICKRBtTRG DIVIRION. 

During the Fredericksburg subepoch the Cretaceous shore reached west and north approximately to a line extending from El Paso north into southwestern KansaR. The area lying south 

and east of this line, as far at least as the eastern border of the Black Prairie, as shown by the 

extent of the Edwards limestone, was a great arm of the sea, the bottom of which was covered 

with calcareous organisms as certain banks of the present West Indian seas are now covered. 

Over the entire area thus covered by the oceanic waters the sea deposited a mantle of arenaceous, argillaceous, and chalky sediments which now make the rocks of the Fredericksburg 

division. * * * 

As a whole, these sediments thicken and become more calcareous seaward, away from the 

position of the old peripheral shore line at the close of the Fredericksburg epoch. * * * 

This thickening took place by the accretion of calcareous layers offshore and horizontally away 
LOWER CRETACEOUS. 603 

from the diagonal basement beds. * * * These changes in thickness were very gradual 

and can only be noted by comparing widely separated local sections. Hence the rocks of this 

division, as a whole, notwithstanding the variations to be noted, may be considered as presenting 

a remarkable example of uniformity of thickness and composition. In its entirety this division 

is composed of more calcareous rocks than the other divisions of the Comanche series. Although 

its interior margins ultimately pass into the Basement sands, this change mostly takes place 

beyond the borders of the east-central province, within which it is practically a great limestone 

formation (Edwards limestone), initiated by beds of clay (Walnut formation) at its base. 

* * * The limestones of the Fredericksburg division thin toward the Rocky Mountains 

and the Ouachita uplifts to the north, and thicken southward or toward the Rio Grande, being 

in the neighborhood of 700 feet in the latter region and less than 30 along the southern foot of 

the Ouachita Mountains of Indian Territory. They ultimately pass into clays and sands 

around the western ends of the Ouachitas in southern Kansas and west of Texas in eastern 

New Mexico. * * * 

In the area of its most typical if not greatest development, in the Grand Prairie region 

between the Brazos and the Colorado, as will be more fully set forth later, the limestone is further 

differentiable into two well-marked mappable subdivisions. In this region all sections of the 

Fredericksburg division present the following sequence: 

1. At the base there are a few feet of calcareous clays intercalated with brecciated limestones, passing up into chalky layers, which become more numerous toward the top. These 

are the Walnut beds. 

2. The chalky bands which begin to appear in the top of the \Yalnut clays are the beginning 

of a succeeding limestone formation (Comanche Peak limestone), which in this region is separated into two well-defined stratigraphic units. (a) The lowest of these is the Comanche Peak 

formation. This formation is composed of compact white rocks which on weathering shatter 

into numerous angular or conchoidal flakes, seldom weathering into ledges, and contain great 

numbers of casts of mollusks and echinoids. (b) Without break or ttpparent change in composition the rocks above the Comanche Peak begin to become harder, weathering into ledges often 

semicrystalline in character, and containing flint nodules and peculiar fossils of the types known 

as Hequienia and Rudistes. These rocks form the Ed·wards limestone. The Comanche Peak 

beds are chiefly distinguishable from the succeeding Edwards limestone by the absence of flints 

and certain very peculiar fossils of the overlying beds, and by the fact that they weather into 

slopes instead of bluffs. 

Stratigraphically there is no break between the various formations, and they pass upward 

or downward into one another by gradual transition. The marly lime of the upper portions of 

the vValnut formation grades into the chalky limestones at the base of the Edwards formation 

without demarcation. 

The combined Comanche Peak and Edwards limestone thins out north of the Brazos, 

where it is no longer separable into individual beds [and is called the Goodland limestone]. On 

the othe~· hand, it thickens south of the Colorado, where several distinct subdivisions could be 

made. 

* * * * * * * * * 

WASHITA DIVISION. 

The vV ashita division has been defined as the uppermost of the three stratigraphic groups 

of the Comanche series. It is composed essentially of sediments laid down in a shallowing sea 

accompanying a regional uplift which followed the subsidence of earlier Comanche time. The 

Fredericksburg division ceases everywhere throughout its extent with the purer limestones of 

the Edwards formation. These limestones represent the deposition of the deepest waters of the 

Comanche epoch and the culmination of the subsidence which had been progressing since the 

beginning of Cretaceous time. The succeeding sediments of the Washita division within the 

east-central province are all of a less purely calcareous, [more] argillaceous, or arenaceous nature. 

* * * * * * * * * 
604 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The beds of the Washita division in general are more varied in composition, of greater 

thickness, and more closely resemble shallow-water deposits toward the northern border region, 

extensive formations of ferruginous sands and bituminous clays occurring in that direction, 

which cease to the south. In general the strata of the Washita division, as a whole, become 

more calcareous to the south, but even this rule has its exceptions. 

As a whole, the group decreases from about 400 feet in the Denison section on Red River 

to less than 175 feet in the Austin section, on the Colorado. This loss in thickness of the Washita 

division to the south is compensated for by a corresponding gain in that direction in the thickness of the Edwards limestone of the Fredericksburg division, so that the thickness of the 

Comanche series in its entirety is not impaired thereby. 

The individual indurated beds of the vV ashita division seldom exceed a foot or two in 

thickness. The strata rarely extend through a hundred vertical feet without conspicuous 

lithologic or faunal changes. These individual beds are remarkably persistent in horizontal 

extension, especially when they are studied in large local areas, preserving their lithologic and 

paleontologic characters without any perceptible change for great distances. When the beds 

are traced through long distances, such as Texas provides, gradual important changes may be 

noted which can be appreciated only by comparison of widely separated minute local sections. 

What is a conspicuous clay formation in the Red River section may become a limestone when 

traced 300 miles south to the Colorado, or a formation which is a limestone upon Red River 

may be a clay on the Colorado. 

Owing to these gradual changes in the character of the rocks the sections of the Washita 

division at the extreme ends of the area treated in this paper, as exemplified in the Denison and 

Austin sections, present entirely different lithological aspects and sequences, the relations of 

which would not be traceable were it not for the existence of certain well-determined paleontologic zones which persist regardless of the lithologic changes. 

* * * * * * * * * 

The Wash ita division presents several well-defined mappable units-eight, for instance, 

along Red River, and only three at Austin, on the Colorado. 

In the region of its typical development as seen in the Red River section there are eight 

broad subdivisions: (1) Basement beds of bituminous clays rather abruptly succeeding the 

Edwards limestone; (2) beds of white, arenaceous, chalky limestone alternating with marls, 

which terminate with (3) a conspicuous limestone formation; (4) a group of beds of marls and 

shell conglomerates; (5 and 6) two groups of clays and sands separated by limestone; (7) an 

upper limestone; and (8) an uppermost lime marl. 

These subdivisions, which are locally still further subdivided into conspicu0us beds, may 

be named the Kiamitia, Duck Creek, Fort vVorth, Denton, Weno, Pawpaw, Main Street, and 

Grayson beds. To the south, in the Colorado sections, only three lithologic members are 

recognizable-the Georgetm"~n limestone, Del Rio clays, and Buda limestones. Each of these 

formations, although possessing very marked and important features in particular localities, 

loses its identity when traced through long distances, by coalescing ·with other formations. 

I 14-15. NORTHERN TEXAS, SOUTHERN OKLAHOMA AND ARKANSAS, AND NORTHERN 

LOUISIANA. 

Of the Lower Cretaceous of this region Veatch 838b writes as follows: 

The lowest Cretaceous beds represent the near-shore deposits of the sea advancing over 

the old Jurassic peneplain and are, therefore, sandy and contain vegetable remains, as well as 

brackish-water shells. These are succeeded by limestone and marls, indicating deeper water, 

and these in turn are limited above by the great sand beds that represent the extreme shallowwater conditions which marked the beginning of the upper Cretaceous. 

In Arkansas only the lowest of the series, the Trinity sand, is well developed, although 

near the Indian Territory line are good outcrops of the Goodland limestone, overlain by a 

series of marl and limestone beds, which, with the Goodland limestone, represent the other 

two grand divisions of the Comanche series, the Fredericksburg and the Washita. 
LOWER CRETACEOUS. 605 

The Trinity sand, the oldest and lowest formation of the Coastal Plain series in this region, 

outcrops in a narrow band 6 to 12 miles wide, which extends westward along the base of the 

Ouachita and Arbuckle mountains from Wolf Creek in Pike County, Arh:., into Indian Territory to a point somewhat west of Ardmore, where it turns south toward Austin. Because of 

its extensive development about the headquarters of Trinity River in ·wise, Tarrant, and 

Parker counties, Tex., it has been called the Trinity sand or Trinity formation. 

South of Tishomingo and Atoka, in the Choctaw Nation, this formation consists of a fine 

yellowish pack sand, with irregular conglomerate beds at the base, and contains occasional 

lenticular masses of clays, the whole having an aggregate thickness of 200 to 400 feet.a In 

this region it contains no fossils except occasional tree trunks, thought by Taff to be driftwood. 

Eastward these beds become more clayey in character and in southern Arkansas contain frequent thin layers of yellowish limestone, composed largely of the small oyster Ostrea franklini 

Coquand, together with other near-shore or brackish-water forms. Occasional thin beds of 

gypsum, like that at the Plaster or Gypsum Bluff on Little Missouri River near Murfreesboro 

occur. * * * 

Above the Trinity formation is a thin bed of chalky limestone 15 to 25 feet thick, which, 

because of its whiteness and firmness, contrasts sharply both with the Trinity sand and with 

the series of marls with thin limestone layers that overlie it. Because of these features it is 

easily traced from its type locality, 2 miles north of Goodland, on the St. Louis & San Francisco Railroad, in the Choctaw Nation, Indian Territory, both eastward to Cerro Gordo, on 

Little River, in Arkansas, and westward past Oakland and Marietta, in the Chickasaw Nation. 

It is everywhere in this region characterized by peculiar fossils. South of Red River in Texas 

it increases gradually in thickness until it reaches a total of 700 feet on the Rio Grande,b 

where it is composed of two members which are called the Comanche. Peak and Edwards 

formations. * * * 

Above the Goodland limestone, near Cerro Gordo, Ark., is a series of calcareous clays, 

containing thin beds of limestone and having a total thickness of over 250 feet.c These beds 

have not yet been carefully studied, but Hill's reconnaissance in 1888 has shown that they may 

be regarded as the representatives of the Preston, Fort Worth, and Denison formations of the 

Texas section and of their equivalents in Indian Territory-the Kiamichi, Caddo, Bokchito, 

and Bennington formations of Taff [Washita group]. * * * 

At the close of the lower Cretaceous there was evidently a considerable change in the depth 

of the ocean waters in the Texas and Arkansas areas, since overlying the marine deposits• of 

the Washita series are sands and clays containing lignite and other remains of land plants of 

species very similar indeed to those of to-day, whose ancesters they probably were. In many 

places there is some evidence of slight erosion of the lower beds before these littoral deposits 

were laid down, and some portions of this area may have been dry land for a limited time. 

I 16-17. ALABAMA, GEORGIA, AND SOUTH CAROLINA. 

L. W. Stephenson has contributed the following notes: 

The basal portion of the Cretaceous deposits in the region included between the Roanoke 

Valley in North Carolina aiid the Alabama Valley in Alabama is composed of highly crossbedded arkosic sands, in general of coarse texture, with subordinate interbedded layers and 

lenses of light-colored clays of greater or lesser purity, reaching an estimated maximum thickness of 500 or 600 feet. These have been designated the "Cape Fear" formation in North 

Carolina by the writer d and the "Ham burg beds" in South Carolina by Earle Sloan e and have 

a Taff, J. A., Atoka folio (No. 79), 1902, and Tishomingo folio (No. 98), 1903, Geol. Atlas U.S., U.S. Geol. Survey. 

b IIill, R. T., Twenty-first Ann. Rept. U.S. Gcol. Survey, pt. 7, 1901, p. 214. 

c Ann. Rept. Geol. Survey Arkansas for 1888, vol. 2, 1888, pp. 110-111. 

d Some facts relating to. the Mesozoic deposits of the Coastal Plain of North Carolina: Johns Hopkins Univ. Circ., 

new ser., No. 7, July, 1907, pp. 93-99. 

e Clays of South Carolina: Bull. South Carolina Gcol. Survey, 4th ser., No.1, 1904, pp. 72-75; Handbook of South 

Carolina, State Dept. Agr., Commerce, and Immigration, Columbia, S. C., 1907, pp. 85-88. 
606 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

been regarded as the eastward continuation of the Tuscaloosa formation (Upper Cretaceous), 

by the Georgia and Alabama geologists.a 

In the Carolinas these beds are separated from the overlying Black Creek formation by an 

unconformity. Likewise an unconformity separates them from the overlying Eutaw formation in the Chattahoochee and Alabama river regions in Georgia and Alabama. Geographically the belt in which the deposits occur is separated from the Cretaceous occurrences to the 

northward in Virginia by an overlap of Miocene beds. However, in all their physical characters 

they bear a close resemblance to the Patuxent formation, which forms the basal division of the 

Potomac group in Virginia and Maryland. On account of this physical similarity and because 

of their supposed buried connection with the Virginia Patuxent, the application of the name 

Patuxent has been extended to include these North Carolina arkosic beds. The appltrent continuity of the North Carolina beds with the similar deposits to the south would, in the absence 

of known unconformities, seem to necessitate the adoption of the name Patuxent for all the 

beds in question in South Carolina, Georgia, and Alabama, unless biologic evidence indicating 

the incorrectness of this interpretation is forthcoming. ·with one exception no organic remains 

have been found in these arkosic beds south of the Virginia line. A few poorly preserved plant 

remains have been collected recently from an exposure in a bluff of Tallapoosa River at Old 

Fort Decatur, in l\facon County, Ala. These were submitted to E. W. Berry, who expressed 

the opinion that the beds containing them are of Lower Cretaceous age. The meager paleontologic evidence thus afforded tends to confirm conclusions which Mr. Berry and the writer 

had previously reached, based on physical criteria alone. Unfortunately the poorly preserved 

condition of the leaves renders it diflicult to determine satisfactorily the relation of the formation to the Patuxent formation of Virginia and Maryland. However, in Mr. Berry's opinion, 

the presence of large numbers of leaves, apparently dicotyledons, most of which are too poorly 

preserved to permit their specific or even generic determination, seems to justify doubt as to their 

being as old as the Patuxent formation, in which similar questionably identified dicotyledons 

are very sparingly represented. 

1-J 13-14. EASTERN NEW MEXICO, OKLAHOMA, AND SOUTHERN KANSAS. 

Portions of the Comanche series appear along the canyons which descend from 

the Tertiary of the High Plains to the" Red Beds." There are unconformities both 

above and below these incomplete sections, which constitute the northwestern 

occurrences of the Comanche series. Hill 441 describes in detail sections observed 

in Kansas, Oklahoma, and New Mexico, with comparative faunal lists, and under 

the title "Plains section" he summarizes the strata as follows: 

Plains Tertiary. 

"Dakota" sandstone. 

Belvidere beds: 

(b) Blue and black shale with fossils [the Kiowa shale of Cragin 172, 174]. 

(a) Cheyenne sandstone grading upward into b." 

"Red beds." 

The fauna consists largely of typical Washita species with a few that range 

down into the Fredericksburg. 

1-K 13. NEW MEXICO, COLORADO, AND WYOMING. 

The Morrison formation of Wyoming and Colorado was formerly referred 

without question to the Jurassic on the evidence of its large vertebrate fauna. More 

recent studies of this fauna by Scott, ·williston, and others favor its reference to the 

Lower Cretaceous, but this assignment of age is not yet unanimously accepted, and 

a Langdon, D. W., Variations in Cretaceous and Tertiary strata of Alabama: Bull. Geol. Soc. America, vol. 2, 

1890, pp. 587-606. Veatch, Otto, Srcond report on the clays of Georgia: Bull. Geol. Survey Georgia, No. 18, 1909, 

pp. 82-106. 
LOWER CRETACEOUS. 607 

the formation is called Jurassic('?) in recent publicg,tions of the United States 

Geological Survey. Its relations to the Comanche series were traced by Stanton,781 

with W. T. Lee and C. W. Gilmore, and are expressed in the following comments 

and sections: 

The beds now generally designated on United States Geological Survey maps as the 

Morrison formation have been a subject of interest and discussion since 1877, when abundant 

remains of dinosaurs were found in them. The first extensive collections of the vertebrate 

fauna were obtained in the neighborhood of Morrison near Denver, in Garden Park, near 

Canon City, Colo., and at Como or Aurora, Wyo. Since then the formation has been recognized 

by means of its fossils, its lithologic features, and its stratigraphic relations in the Black Hills, 

on the Laramie Plains, and elsewhere in Wyoming, in Montana, in western Colorado, in southeastern Colorado, and in adjacent parts of Oklahoma and New Mexico. * * * 

The formation is nonmarine throughout, so far as known, and consists of variegated marls 

and shales with irregular beds of sandstone and sometimes thinner layers and lenses of siliceous 

limestone. The colors of the shales and marls are greenish gray, purplish, maroon, and red, 

very irregularly distributed, while the sandstones are usually gray, sometimes weathering 

brown or with small brown spots. The limestones are gray, in some cases weathering with a 

reddish tinge. The general appearance of the formation is remarkably uniform over large 

areas, and yet the individual elements are so variable that no two detailed sections are exact 

duplicates of each other. The total thickness is seldom more than 200 feet, though it is 

possibly more than 400 feet at Canon City. 

Several geologists, particularly Hill and Lee, having suggested that the 

Morrison was a representative of some part of the Comanche series, Stanton examined 

its relations, as stated above, and found: 

Section on Purgatoire River about 20 miles south of La Junta, Colo. 

1. Benton shales, thickness probably not more than .... __ ...... _ ....... __ ...... ________ . _ 

2. Dakota sandstone ................................. ___ ...... _ ............... ______ ... _ 

3. Dark shales and shaly limestones with Comanche fauna ............................... _ 

4. Coarse gray cross-bedded sandstone ....................... _ ................ _____ .. _._ 

5. Variegated shales, marls, sandstones, and limestones of the Morrison formation, with BronFeet. 

200 

100 

50-100 

15-60 

tosaurus, etc ..................................................................... _ 200 

6. Gypsum and gypsiferous shales...................................................... 70-125 

7. Red Beds with Belodon near top, exposed ............................................ 200-300 

Section on Rio OimaTTon east of GaTTett post office, Okla. 

Feet. 

1. Massive coarse cross-bedded gray and brown sandstone of the Dakota .......... _ . . . . . . . . 150 

2. Dark shales with layers of brown flaggy sandstone and bands of somewhat calcareous 

yellow sandstone with Comanche fauna ........................................... _ 50-60 

3. Coarse brown or gray cross-bedded sandstone with irregular bands of pebbles, apparently 

unconformable on the underlying stratum.......................................... 4-15 

4. Variegated shales, gray sandstones and bands of siliceous limestone, referred to the Morrison, not well exposed. Thickness probably less than..... . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 

5. Red Beds. 

The Comanche horizon has yielded a varied fauna which is clearly the same as the Washita 

fauna that has long been known as Mesa Tucumcari, New Mexico, in northern Texas, and in 

the Kiowa shales of southern Kansas. * * * 

This horizon was traced with practical continuity westward up the Cimarron to Folsom, 

New Mexico, a distance of about 75 miles across the strike. Its lithologic features show little 

variation, and its thickness is never less than 50 feet nor more than 100 feet. Fossils gradually 

become less abundant in both species and individuals toward the west, until near Folsom only 

a small mactroid shell was found in considerable numbers. The most western point at which 

Gryphr£a coTTugata was collected is about 30 miles east of Folsom. 

Along this line the coarse sandstone beneath the Comanche fossils is from 15 to 40 feet 

in thickness, and the variegated shales, sandstones, etc., of the Morrison increase to about 200 
608 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

feet. Lithologically and stratigraphically this is identical with the Morrison beds seen on 

the Purgatoire, where characteristic dinosaurs were collected. Fragmentary, undetermined 

dinosaur remains were seen in it on the Cimarron near Exter, N. Mex. 

Beneath the recognized Morrison some localities show 40 to 50 feet of gypsum and gypsiferous shales resting on a massive white or pinkish sandstone which Mr. Lee has described as 

the Exter sandstone. It varies greatly in thickness, the maximum observed being 80 feet. 

The Exter is separated from the red beds by a striking angular unconformity, wherever the 

red beds are folded in local uplifts. The red beds show the usual character and at Tod's 

ranch, 15 miles east of Folsom, they yielded fragmentary Triassic vertebrates. 

Summing up the evidence presented by the sections quoted and also by those 

at Tucumcari and Canon City, Stanton says: 

The question whether the Morrison formation is Jurassic or Cretaceous is still to be 

answered, and if a satisfactory answer is ever received it will doubtless be from vertebrate 

paleontology, aided by careful stratigraphic methods. If the Morrison is Cretaceous, the 

proof that it is so will not be by tracing it directly into marine Cretaceous strata. It has been 

shown that the beds supposed to be thus connected with it overlie it for more than 100 miles 

across the strike. But these overlying beds are by no means the earliest Cretaceous, and there 

is still room for the Morrison within that system if the fauna requires such a reference. On 

the other hand, there is ample space for it in the Jurassic a not otherwise represented in the 

region by sediments, and before the final decision is made the character of the flora in the 

Fuson formation of the Black Hills and in the Kootanie of Montana should be given due weight, 

and these formations should be closely studied and searched for other evidence. 

1-K 17-18. ATLANTIC COASTAL PLAIN, MASSACHUSETTS TO NORTH CAROLINA, INCLUSIVE. 

The following statement, prepared by William B. Clark, is an elaboration 

of a briefer article 144 covering the northern part of the Atlantic Coastal Plain: 

General conditions of occurrence.-The oldest deposits of the Atlantic Coastal Plain which 

outcrop at the surface are of Cretaceous age. Well borings at many points throughout the 

district have not afforded strata of earlier age, although such deposits may exist to the east, 

toward the margin of the continental shelf. 

The deposits as a whole have been but little changed since they were originally laid down 

along the continental border, but the strata present much complexity due to the variation in 

the angle and direction of tilting during the successive oscillations of the sea floor during Cretaceous time. The sediments in general form a series of thin sheets which are inclined seaward, so that successively later formations are encountered in a journey from the inland border 

of the region toward the coast, yet at no place accessible to our study do we find a complete 

sequence of deposits, although sedimentation must have been continuous over a large part of 

the continental shelf. The incompleteness, therefore, must be regarded as a purely marginal 

condition due to the transgressions and retrogressions of the sea along the coastal border. 

The Cretaceous formations are variously transgressed in the different areas by deposits of 

Tertiary and Quaternary age, these later formations in places reaching to the Piedmont border 

or beyond and entirely concealing the earlier strata along the outcrop. The full sequence of 

Cretaceous deposits can therefore be observed only at favorable points and chiefly along the 

main river channels, although even here the later formations are buried over many wide areas 

in consequence of the attitude of the strata to the present sea level. 

The Atlantic Coastal Plain deposits afford representatives of both the Lower and the 

Upper Cretaceous, the former being most extensively developed in Maryland and northern 

Virginia and in North Carolina, the latter in New Jersey, whence the strata gradually 

thin out northeastward along the New England coast and southward through Delaware and 

a The marine Jurassic Sundance formation, characterized by Cardioceras cordiforme M. and M., etc., on which the 

Morrison rests in the northern area, does not represent the latest Jurassic according to European standards. 
LOWER CRETACEOUS. 609 

Maryland. In North Carolina the Upper Cretaceous reappears and covers a wide area to the 

south of the Hatteras axis. 

Long Island and southern New England.-It has been long recognized that Upper Cretaceous 

deposits occur on Long Island and farther east, but although it has been apparent that the 

strata were the continuation of similar deposits in New Jersey, where their limits are better 

known, a satisfactory correlation of these deposits has never been made. It is apparent that 

the Raritan, the Magothy, and possibly the overlying Matawan arc represented. The flora 

thus far studied is chiefly of the Magothy type, although the lower beds on Long Island contain 

forms that represent the Raritan, while the marine animal remains which have been found both 

in place and in reworked deposits on Long Island, Block Island, and Marthas Vineyard and at 

Marshfield, Mass., are of Matawan types so far as they can be determined. It is possible that 

they belong to beds in the upper Magothy, for marine fossils have been found in Magothy 

strata on the south shore of Raritan Bay, the fauna as a whole being similar to that of the 

Matawan. 

Many contributions have been made to the knowledge of this region by those who have 

visited and studied it, among the more important being those of Newberry/10, 611 Shaler,728' 729, 730 

David White,893' 894 Hollick, 457,458, 459 and Veatch.837 

The strata consist of sands and clays, the former in places irregularly bedded and of varying 

degrees of fineness and more or less stained with iron, while the latter are plastic and locally 

lignitic. Sandy, more or less glauconitic clays have also been found. 

New Jersey.-The deposits of Upper Cretaceous age are more extensively developed in 

New Jersey than elsewhere in the northern Atlantic Coastal Plain and may be regarded as 

forming the type section for that region. The major divisions can be more elaborately differentiated there than farther south and a much fuller classification has been proposed. 

A study of the Cretaceous deposits of the New Jersey region began much earlier than in 

neighboring States and many contributions have resulted. Among those who have given 

a large amount of attention to the geology of this area are Morton,606 Cook/69 Newberry/14 

Whitfield,925 Clark,H2, 145, 146, 152 W eller,ss4 and Berry ,n, 76, 78 

The following scheme of classification has been adopted for the New Jersey Upper Cretaceous: 

Manasquan formation. 

Rancocas group: 

Vincentown sand. 

Hornerstown marl. 

Monmouth group: 

Redbank sand. 

Navesink marl. 

Mount Laurel sand. 

Matawan group: 

Wenonah sand. 

Marshalltown formation. 

Englishtown sand. 

Woodbury clay. 

Merchantville clay. 

Magothy formation. 

Raritan formation. 

The Raritan formation directly overlies the crystalline rocks or the Newark group, as the 

case may be, and consists of clays, sands, and gravels. It has been estimated to have a maximum thickness of about 300 feet at the outcrop, but it has been penetrated in well borings to a 

probable depth of 500 feet. An extensive flora has been described. 

The Magothy formation unconformably overlies the Raritan formation and consists of 

dark clays and light sands. The clays are commonly lignitic. The deposits attain a maximum 

thickness of about 100 feet. An extensive flora quite distinct from and more recent than the 

Raritan flora has been found, as well as a marine fauna closely allied to that of the succeeding 

Matawan. 

48011°--12----39 
610 INDEX TO THE STRATIGRAPHY OF NORTH Al\'[ERICA. 

The Matawan consists chiefly of dark-colored clays, in places micaceous and glauconitic, 

in its lower part, and of sands, with an interbedded clayey member, locally highly glauconitic, 

in its upper part. It attains a total thickness of about 275 feet, although a thickness of 400 

feet has been found in deep well borings east of its outcrop. It lies unconformably on the 

Magothy. The Matawan group contains an extensive fauna with subordinate faunules. It 

has been traced throughout the north Atlantic Coastal Plain and thence southward to the Gulf. 

The Monmouth group consists of sands and clays, with an interbedded glauconitic division 

in the northern part of the area. Toward the soutlt the upper sandy formation disappears. 

The greatest thickness of the group is about 150 feet. The Monmouth is conformable to the 

Matawan. It has an extensive fauna marked by the introduction of Belemnitella americana 

and other forms, representing a later fauna than the Magothy and Matawan fauna hitherto 

described. This fauna also has been traced southward through the north Atlantic Coastal 

Plain into the Gulf region. 

The Rancocas consists largely of greensand marls and sandy calcareous beds which have 

a maximum thickness in southern New Jersey of about 125 feet. It is conformable to the 

Monmouth and is characterized by a fauna quite distinct from the preceding, including Gryphrea 

vesicularis, Terebratula harlani, and other forms. 

The Manasquan formation consists of greensand marls and attains a thickness of about 50 

feet. It is conformable to the Rancocas. It contains a marine fauna which has some forms in 

common with the Rancocas and others that are quite distinct. 

Maryland and Delaware.-The deposits in Maryland and Delaware contain representatives 

of both the Lower and the Upper Cretaceous. The Lower Cretaceous also continues northward 

into Pennsylvania, where a few isolated outliers are found, and the basal formation of the 

Upper Cretaceous occurs as a narrow strip along the eastern border of that State. In Maryland 

and Delaware both divisions are extensively developed, the Lower Cretaceous attaining its 

maximum development in Maryland. 

The Maryland area has been long studied and is discussed in an extensive literature. Among 

those who have been most actively engaged in the study of this region may be mentioned 

McGee/65 Clark,141' 148,

150 Bibbins,147' 148 Mathews/ 50 Berry, and Miller.595 

The following scheme of classification has been adopted for the Maryland-Delaware region: 

Upper Cretaceous: 

Rancocas formation. 

Monmouth formation. 

Matawan formation. 

Magothy formation. 

Raritan formation. 

Lower Cretaceous (Potomac group): 

Patapsco formation. 

Arundel formation. 

Patuxent formation. 

The Patuxent formation consists mainly of sand, generally arkosic and in many places 

cross-bedded, with small masses of clay scattered through it. . The formation attains a thickness 

of 350 feet. It has a well-defined early Cretaceous flora. 

The Arundel formation consists chiefly of clays, which in places carry iron ore and are 

commonly lignitic. It has a thickness of about 125 feet. It is unconformable to the Patuxent. It has an extensive flora similar to that of the Patuxent and a fauna consisting chiefly of 

dinosaurian remains. 

The Patapsco formation consists of highly colored and variegated clays and lighter-colored 

sandy clays and sands. It has a thickness of 200 feet and contains an extensive flora of "MesoCretaceous" types in which angiosperms constitute a considerable element. It is unconformable 

to the Arundel. 

The Raritan formation consists chiefly of thick-bedded light-colored sands, with lightcolored clays in the lower portion. The deposits have a. thickness of about 400 feet. The 

Raritan overlies the Patapsco unconformably. It carries a distinctly Upper Cretaceous flora 

containing numerous dicotyledons. 
LOWER CRETACEOUS. 611 

The Magothy formation consists of alternating sands and clays, the latter in places lignitic. 

The maximum thickness of the formation is about 100 feet. The Magothy is unconformable 

to the Raritan. It contains an extensive flora of types more recent than those of the preceding 

formation. 

The Matawan formation consists mainly of dark-colored micaceous sandy clays, the average 

thickness of the formation being about 50 feet. It carries an extensive marine fauna. 

The Monmouth formation consists mainly of sands, more glauconitic in the upper part 

than in the lower. The deposits have a maximum thickness of about 100 feet on the eastern 

shore of Chesapeake Bay and gradually decrease in thickness until they thin out in the Potomac 

Valley. A fauna marked by the advent of Belemnitella americana and other forms is found 

in this formation. 

The Rancocas formation consists chiefly of greensand marls, which are in many localities 

highly calcareous. The formation has a thickness of about 20 feet in central Delaware but 

gradually thins out toward the Maryland line. 

Virginia.-The Cretaceous deposits which outcrop at the surface in Virginia are all Lower 

Cretaceous, although strata belonging without much doubt to the Upper Cretaceous have been 

penetrated in deep well borings to the east and have yielded a few fossils that indicate the 

presence of the Raritan, Magothy, and Matawan formations. The Lower Cretaceous deposits 

are limited to the Patuxent and the Patapsco, the Arundel formation not being recognized 

in Virginia. 

Much study has been given to the Virginia area, the more important contributions having 

been made by Rogers,676 Ward,S64•

866 Fontaine,S43 Clark and Miller/51 and Berry. 77 

The Patuxent formation is exposed in the principal drainage channels and consists chiefly 

of sands, cross-bedded, highly arkosic, and locally indurated, with clay beds in places lignitic 

and commonly chloritic. The thickness of the formation reaches about 300 feet. The Patuxent contains a large flora which is p~obably the most extensive known flora from the Lower 

Cretaceous. 

The Patapsco formation consists of highly colored and variegated clays, in places lignitic, 

and sand beds, cross-bedded and locally indurated. The formation is limited to the northern 

part of the area, where it attains a thickness of about 150 feet and has an extensive flora of 

later types than those found in the Patuxent. 

North Oarolina.-The Cretaceous deposits of North Carolina belong in part to the Lower 

and in part to the Upper Cretaceous. In the northern part of the State the strata are confined 

largely to the main river channels, but south of the Hatteras axis they spread out and occupy 

a wide area. 

The North Carolina deposits have not received as much attention until recently as the 

Cretaceous deposits farther north. Among those who have studied the region are Clark,141 

Stephenson,791 and Berry. 73• 74• 77• 79 The two latter have spent much time in recent years in a. 

detailed field investigation, Stephenson giving his attention chiefly to the stratigraphy and marine 

invertebrate fossils and Berry to the fossil plants. Clark, who earlier studied the region, has 

devoted his attention to the interpretation of the deposits and faunas and their correlation 

with other areas. 

The following scheme of classification has been accepted for the North Carolina area: 

Upper Cretaceous: 

Peedee sand. 

Black Creek formation. 

Lower Cretaceous: 

Patuxent formation. 

The Patuxent formation consists chiefly of sands and clays, the former locally cross-bedded 

and arkosic. Its thickness is about 300 feet. No flora or fauna has been found in it. 

The Black Creek formation consists of light-colored sands and interbedded clays, the latter 

in places lignitic and generally thinly laminated. The thickness of the formation reaches about 

700 feet. The Black Creek overlies the Patuxent formation unconformably. An extensive 

flora is found in it, the beds carrying the plant remains being interbedded with strata containing 
612 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

marine invertebrate fossils in the upper portion of the formation. The fauna is extensive and 

is similar in typo to that found farther north in the Magothy and Matawan formations and it 

has also been traced throughout the south Atlantic States to the Gulf. 

The Poodee consists mainly of sands, commonly glauconitic, with subordinate beds of clay. 

The thickness of the formation reaches about 700 feet. Tho Peedee carries an extensive fauna of 

marine types, which is characterized by the introduction of Belemnitella americana and is similar 

to the Monmouth fauna farther north. It has also been traced through the south Atlantic 

and Gulf States. 

General remarks.-The Cretaceous deposits of tho Atlantic Coastal Plain form an irregular 

and interrupted belt along its western margin, resting for the most part on an irregularly eroded 

surface of ancient crystalline rocks, although the sandstones and shales of the Newark group 

intervene at some points. The slope of this floor is variable, but on the average it trends in 

an easterly direction at an angle of about 60 feet to the mile. 

The thickness and angle of dip of the Cretaceous formations at the outcrop are extremely 

variable owing to the differential movements which have taken place along the landward margin of 

the Coastal Plain during the period of its building. The areas occupied by the outcrops of the 

several formations above described gradually diminish at varying rates from the point of their 

greatest development, until the formations finally disappear as outcropping deposits either 

because of the differential movements during Cretaceous time or because of the transgression 

of Tertiary and Quaternary sediments. The dip of the several formations is also variable but 

in general grows less with each succeeding formation, the dip of the latest Cretaceous strata 

being about 20 feet to the mile. 

The correlation of the deposits within the limits of the northern Atlantic Coastal Plain is 

shown in the accompanying table, together with the approximate correlation of these deposits 

with the section hitherto recognized in the eastern Gulf region and in central Europe. L. W. 

Stephenson and E. W. Berry, under the direction ofT. Wayland Vaughan, have greatly enlarged 

our knowledge of the stratigraphy and paleontology of the south Atlantic and Gulf States and 

the results of their work have been available for the comparisons with the southern districts 

south of North Carolina. 

Cretaceous formations of northern Atlantic Coastal Plain. 

I 

Long Island 

Approximate and islands Delaware North European south of New Jersey. and Virginia. Carolina. Alabama. 

equivalents. New Eng- Maryland. 

land. 

Manasquan. 

Danian. ---~~- ---

Rancocas. Rancocas. 

Upper Creta- Monmouth. Monmouth. Peedee. Ripley and 

ceo us. Senonian. Selma. 

Matawan. Matawan. Matawan. 

Eutaw. 

Blr.ck Creek. 

Turonian. Magothy. Magothy. Magothy. Tuscaloosa 

(western 

-1--·· I Alabama). 

Cenomanian. Raritan. Raritan. Raritan. ...... (?) .... 

Albian. I Patapsco. Patapsco. ...... (?) .... 

j ·---~ - ___ __, ___ Lower Cretaceous 

Lower Creta· Urgonian. Arundel. (eastern ceous. ----- -~----- Alabama). 

Neocomian. Patuxent. Patuxent. Patuxent. ...... (?) .... 
LOWER CRETACEOUS. 613 

The Lower Cretaceous formations in the area under discussion constitute part of a belt 

of deposits of that age extending from Pennsylvania to eastern Alabama and are apparently 

embraced within a single geologic province. North of central Maryland, where the most 

complete sequence of the Lower Cretaceous strata is found, the Arundel and Patuxent formations are gradually transgressed by the unconformably overl_yi.ng Patapsco formation, 

which in turn disappears by the overlapping of the Raritan formation in eastern Pennsylvania 

and in New Jersey. 

Farther south, in Virginia, the Patapsco formation disappears near Fredericksburg and 

does not reappear except in a single occurrence still farther south, and the Arundel formation 

is not known to occur south of Potomac River. With the single exception above noted the 

Patuxent is the only Lower Cretaceous formation exposed in south-central and southern Virginia, 

where in the valley of James River some of the most fossiliferous beds of this formation have been 

found. Although separated at the surface from the deposits of the same formation farther 

north, through the transgression of the Tertiary and Quaternary formations, the continuity 

of the beds is assumed from the similarity of the flora, with its many identical species, as 

well as from the characteristic lithology. 

Deposits formerly called the "Cape Fear" formation but now known to be a southward 

continuation of the Patuxent formation of Virginia are found in North Carolina. Here again 

the transgression of the Tertiary and Quaternary formations interferes with the continuity of 

the outcrop, although there is no reason to doubt that the deposits are continuous beneath 

the later strata. No fossils have thus far been discovered in the Lower Cretaceous deposits 

of North Carolina, but the strata occupy the same stratigraphic position at the base of the 

Coastal Plain Cretaceous here as farther north and are unconformably overlain by Upper 

Cretaceous formations. The deposits are also strikingly similar to those of the Patuxent 

formation in Virginia and Maryland and it seems to be a reasonable assumption that they 

constitute part of the same formation. 

To the south of North Carolina similar deposits are known to extend through South 

Carolina and Georgia into eastern Alabama. The more southern occurrences of the Lower 

Cretaceous were long erroneously associated with the Tuscaloosa formation (Upper Cretaceous) 

farther west in Alabama and Mississippi, but they are entirely distinct from that formation 

both in stratigraphic position and in lithologic character, and they are separable everywhere 

by marked unconformities from the overlying Upper Cretaceous deposits. According to the 

evrdence at present available, they are physically continuous with the Patuxent formation 

farther north, whether or not the same formational name is employed throughout the province. 

Notwithstanding the physical evidence in favor of a single formational unit at the base of the 

Coastal Plain Cretaceous all the way from Maryland to Alabama, it must be admitted that 

a transgressing sea throughout so extended a coast line might well have involved considerable 

time for its accomplishment and if the transgression proceeded from the north toward the 

south, as seems probable, the deposits in Alabama would necessarily be somewhat younger 

than those in Virginia and Maryland. 

The Upper Cretaceous deposits within the area under discussion constitute part of a belt 

that is known to extend from :Massachusetts through the islands off the New England coast 

and thence to the Gulf except at a few points where transgression or erosion has removed 

evidence of their presence. The most complete sequence of strata is found in New Jersey, 

north of which the later Upper Cretaceous formations are lacking, although the earlier formations continue through Massachusetts with their characteristic if somewhat incomplete 

faunas and floras. To the south the Raritan and Rancocas formations finally disappear in 

Maryland, but the intervening :Magothy, :Matawan, and Monmouth formations with their 

characteristic faunas and floras can be traced through Maryland, can be recognized in Virginia 

in the deep well borings to the east of the Cretaceous outcrops, and reappear in North Carolina 

in the Black Creek and Peedee formations. The boundary between the Matawan and the 

Monmouth in the north, as well as that between the Black Creek and the Peedee in the south, 

marks the division between the earlier fauna and the later Belemnitella americana fauna. The 
614 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

lower fauna characteristic of the :Magothy and Matawan and the Black Creek has been found 

in the lower part of the Ripley formation and in the Selma chalk, also in the Eutaw; the 

upper fauna of the Monmouth and the Pcedee is found in the upper part of the Ripley and 

the Selma. The flora of the Magothy characteristic of the New England area and of New 

Jersey and Maryland is represented in the Black Creek and also in the Tuscaloosa of western 

Alabama and Mississippi. 

The Cretaceous formations of the northern Atlantic Coastal Plain have been correlated with 

the recognized European subdivisions and the faunas and floras examined have led Clark and Berry 

to propose the approximate equivalents given in the table on page 612. The Lower Cretaceous 

floras are regarded as comprising the Neocomian to the Albian, the Patuxent flora being distinctly a Neocomian :flora and the Patapsco an Albian flora. The Upper Cretaceous floras and 

faunas extend from the Cenomanian to the Danian, the Raritan flora containing a large Cenomanian element, while the Magothy and Black Creek floras are regarded as Turonian. The 

faunas which are found in succeeding beds are in the Matawan and Black Creek apparently 

Turonian, although regarded by some paleontologists as Senonian; those of the younger Monmouth and Peedee are unquestionably Senonian. The later Rancocas and Manasquan faunas 

of the northern part of the Coastal Plain are regarded as Danian and probably belong to the 

horizon of the Maestricht. 

J 14. CENTRAL KANSAS. 

Cragin 173 describes the occurrences of marine Lower Cretaceous m Saline 

County, Kans., in part as follows: 

The Mentor beds, named from a small station in Saline County, Kans., within the area of 

their outcrop, are a terrane of variegated, earthy-textured marine shales, with intercalated 

beds of brown sandstone, resting in part conformably upon the Kiowa shales and in part unconformably upon the drab and purple-red laminated shales and impure limestones of the Permian, and succeeded above by the more heavily arenaceous fresh-water sediments of the Dakota. 

They were formerly considered by all geologists as constituting a part of the Dakota group, 

but are now known to belong to the upper part of the Comanche series. * * * 

The shales of the Mentor beds are chiefly argillaceous, but they contain a greater or less 

admixture of sand, to which, as soft sandstones, they locally give place in certain horizons. 

They apparently contain some lime also, partly in the condition of sulphate. * * * Such 

outcrops of the shales as do occur present themselves either as limited, more or less steep-faced 

banks of marly-appearing clay, of white, ferruginous-yellow, red, or blue color, or particolored 

with two or more of these. Their coloring seems to be the result of the variable distribution 

of oxide, peroxide, and sulphates of iron. 

The sandstone of the Mentor beds occurs in thin, local strata. While these are of slight 

consequence judged by the space they occupy, they are nevertheless of great stratigraphic 

importance, since it is from these alone that our knowledge of the geological age of the Mentor 

terrane has been derived. * * * 

The thickness of the Mentor beds varies greatly, since that portion of the terrane that 

rests directly upon the Permian lies unconformably upon the latter and presents considerable 

differences in the elevation of its base. It probably nowhere greatly exceeds 50 or 60 feet. 

* * * *' * * * * * 

The Mentor beds are thus seen to be characterized by a fauna related to that of the Denison 

beds and still more closely to that of the Kiowa shales. Their fauna is, in fact, especially related 

.to that of the upper part of the latter. 

The stratigraphic relation to the Kiowa shales is also close. While the Mentor beds generally rest upon the Permian in Saline County, they rest in part upon the Kiowa shales farther 

southward, as shown by the occurrence beneath them of black shales amongst some of whose 

fossils, submitted to the writer from a few miles west of Lindsborg by Prof. J. A. Udden, are 

Modiola stonewallensis nob. and Sphenod·iscus pedernalis Roem.; but whether they are to be 
LOWER CRETACEOUS. 615 

considered as overlying all of the Kiowa or only a lower part of it, and whether or not they 

merge southward into the upper part of the Kiowa, are questions that remain still unanswered. 

J'-K 10. CALIFORNIA. 

The general character and relations of the Cretaceous of the Pacific coast from 

southern California to British Columbia are ably discussed by Anderson,27 who 

describes and correlates the separate sections and their faunas. 

The Cretaceous of California is divided into the Shasta (Lower Cretaceous, comprising the Knoxville and Horsetown formations) and the Chico (Upper Cretaceous). 

They have been described as the "Shasta-Chico series" by Diller and Stanton,284 

who give a comparative table of classifications according to Gabb's, White's, and 

their own observations, and state: 

The Chico, Horsetown, and Knoxville beds have been found to grade into one another in 

such a way as to show that they are simply different phases of one continuous series of deposits 

extending without an important interruption of any kind from the bottom of the Knoxville 

to the top of the Chico. For this set of beds the term Shasta-Chico series has been proposed.a 

The type section of the "Shasta-Chico series" was measured on Elder Creek, 

in northern California, and originally stated in detail by Diller.270 The following is 

condensed from his statement: 

Feet. 

Chico: Massive and thin bedded sandstone, with conglomerates .......................... _._ 3, 897 

Horsetown: Sandstones, often thin bedded, and shales .. _ ....... _ ..... _ ..... _ ....... _ ..... _ 6, 109 

Kno:x:ville: Shales, with calcareous layers in the upper 10,000 feet, interbedded with sandstones below- __ ---_._-.-_._-- __ ·---_ ... -._.-._---- __ ._- ___ .- ____ . _____ ._._. _____ ._. ___ 19,974 

Apparent total thickness of unaltered strata .. ______________ . _____ .- ________________ [29, 980] 

The Chico (Upper Cretaceous), though generally conformable in the Valley of 

California to earlier Cretaceous formations where they occur, overlaps them in many 

localities. This is the case in the section on Chico Creek, in the northeastern part 

of the Valley of California, where the underlying rocks are metamorphosed auriferous slates.269' 27 

Lists of the faunas from different horizons of the "Shasta-Chico series" are 

given in the paper by Diller and Stanton 284 already cited, but Stanton 776• 778 discusses the faunas and also the stratigraphy in two later papers, of which that of 

1895 assembles the facts of distribution and stratigraphic relations more comprehensively and clearly. 

The remarkable thickness assigned to the Knoxville formation in Tehama 

County is in a measure borne out by the observations of Osmont 624 in the region 

north of San Francisco Bay: 

The eastern portion of both sections is largely made up of Cretaceous shales and l'andstones, 

most if not all of which probably belong to the lower Cretaceous or Knoxville series.b 

This series consists of an enormous thickness of rather hard tawny-yellowish sandstone, 

interbedded in monotonous succession with dark-blue fissile shales, with occasional thin beds 

of dark-blue limestone. The sandstone strata are usually less than 2 feet thick, and almost 

never more than 10, while their regular alternation with s.oft shale made the bedding very 

distinct and characteristic. · 

a Bull. Geol. Soc. America, vol. 4, pp. 205-224, 245-256. Since the papers referred to were written we have spent 

several months in the field, completely reviewing the Cretaceous of northern California. The results fully confirm our 

previous views. 

b Becker, G. F., Quicksilver deposits of the Pacific slope: Mon. U. 8. Geol. Survey, vol. 13, 1888. 
616 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

While standing at high angles, these beds do not show any important faulting along either 

of the sections. From near Knoxville, where they appear to overlie a large laccolith of serpentine, they extend in unbroken succession with steep northeasterly dip, to the head of Capay 

Valley, at Rumsey, where they are covered by Tertiary gravels and sandstones. The average 

angle of dip from Knoxville to Rumsey can not be less than 45°, which would give the series a 

thickness of 4 miles, and this does not represent the whole of the accumulation of sedimentary 

beds, since the upper limit is not exposed. 

In the Coast Range south of San Francisco the Lower Cretaceous strata are 

less fully represented than they are to the north. In the Santa Cruz quadrangle 97 

the Knoxville is but 100 feet thick and is bounded by unconformities above and 

below. (See Chapter XV, p. 669.) In the San Luis quadrangle 325a the relations 

are as follows: 

Strata of Cretaceous age in California include three main groups-the Knoxville, Horsetown, 

and Chico. Two of these, the Knoxville and the Chico, are widely distributed throughout the 

Coast Ranges, and their representatives, the Toro and Atascadero formations, are found within 

this quadrangle. Nothing corresponding to the Horsetown group has been recognized here, 

and probably the horizon is represented by an erosion unconformity. 

It has been thought that the Cretaceous sediments in California formed a conformable 

series from top to bottom, but, in tho central Coast Ranges at least, this period was broken 

two or more times by igneous outbursts, with one long interval of elevation and erosion. 

The Toro formation within the San Luis quadrangle consists of more than 3,000 feet of dark 

shale and thin-bedded sandstone. The formation is named from a creek which flows across it. 

The shale forms almost the whole of the bottom and middle portions. The sandstone is more 

abundant toward the top. The formation is not supplied with many fossils, for, excepting 

one specimen of an ammonite, tho only species found is one belonging to the genus Aucella. 

This is very abundant through the middle and lower portions of the formation. 

The Toro formation is the local representative of the Knoxville group, but it probably 

corresponds to a small part only of Knoxville time, the rest being represented by the unconformities above and below. It belongs to the lower Cretaceous or Shasta series. 

The Cretaceous sequence on the west side of the Valley of California, near its 

south end, in the Coalinga district, is thus described by Arnold and Anderson: 34a 

The next to the oldest terrane exposed in the Coalinga district is a thick series of strata 

of sandstone, shale, and conglomerate overlying the Franciscan formation and covering a wide 

belt for the most part west of the foothill region. It forms the high ridges bordering the Coalinga 

:listrict on the west and may be easily recognized by the dark, thinly bedded, compact shale 

and sandstone of its lower portion and the massive drab concretionary sandstone of its upper 

portion. These strata are of Cretaceous age and comprise part or all of the two formations 

well known elsewhere on the west coast as Knoxville (Lower Cretaceous) and Chico (Upper 

Cretaceous). * * * 

The Horsetown formation, which forms the middle portion of the Cretaceous in the standard 

Coast Range section, is not known to be represented in the Coalinga district, although it is not 

impossible that a portion of the great thickness of nonfossiliferous Cretaceous strata may be 

the equivalent of this formation. No evidence, however, has yet been found of its presence 

in this portion of the Coast Ranges. 

A conservative estimate places the total thickness of the strata mapped as KnoxvilleChico at 12,800 feet. The maximum thickness is probably much greater. This succession of 

strata may be divided lithologically into three main divisions. The total thickness of the middle 

and upper .divisions, which are probably to be referred together to the Chico formation, is at 

least 9,500 feet. A thickness of 8,300 feet is measurable in single sections, and even greater 

thicknesses may be found in single sections of the Knoxville-Chico as a whole. It is likely that 
LOWER CRETACEOUS. 617 

at least two unconformities separating the Knoxville-Chico beds into important stratigraphic 

groups will be made out on further study. * * * 

A zone of coarse conglomerate varying in thickness from less than 100 to over 1,000 feet 

extends intermittently from the summit of Juniper Ridge, south of Los Gatos Creek, to a point 

south of Reef Ridge, in Big Tar Canyon. It is overlain and underlain, in appearance conformably, by the thin-bedded dark shale and sandstone of the lower half of the Knoxville-Chico. 

The portion of the terrane lying below this conglomerate is here classed by itself as the lower 

division. * * * The total thickness of the lower division as exposed in the Alcalde Canyon 

section is between 3,100 and 3,500 feet. * * * 

Fossils of Knoxville (Lower Cretaceous) age, such as Aucella crassicollis Keyserling and 

Belemnites impressus Gabb, have been found in beds of dark shale in the Devils Den region 

not many miles south of the Coalinga district, and there is little doubt that the lower division 

of the rocks here described as Knoxville-Chico is at least in part the equivalent of the Knoxville 

formation. It is possi,blo that the great beds of conglomerate mark the base of the Chico 

or Upper Cretaceous and that the whole of the lower division below this line of separation 

represents the Knoxville formation. 

For reference to the views of F. H. Knowlton and James Perrin Smith on the 

Jurassic age of that part of the Knoxville which contains a Jurassic flora, see the 

next section (K 10). 

For a general correlation table of the Mesozoic and Cenozoic formations of 

the Coast Range, see Chapter XVII (p. 818). 

K 10. KLAMATH MOUNTAINS, OREGON AND CALIFORNIA. 

In his published articles Diller 276 has recognized representatives of the Knoxville, Horsetown, and Chico of the California Cretaceous section in the Klamath 

Mountain section. 

The strata of conglomerate, sandstone and shale, which are believed to represent 

these epochs, are comprised in the Myrtle formation. The strata are irregular, 

but shale predominates. The coarser detritus is derived from disintegrated granite. 

In the Roseburg quadrangle the thickness is estimated at about 6,000 feet. Fossils 

from the upper portion include Pecten operculijormis and Trigonia CEquicostata, 

characteristic of the Horse town epoch. A ucella crassicollis and A. piochii are found 

in the lower portion, the equivalent of the Knoxville. The Myrtle formation 

includes limestone lentils which contain Opis calijornica and Hoplites dilleri or a 

form closely related to it. These are also found in the Knoxville. 

The Myrtle formation is bounded by very marked unconformities both above 

and below and is intruded by igneous rocks and metamorphosed.274' 277 

The relations of the Myrtle formation to the Horsetown and the upper part 

of the Knoxville are apparently established beyond doubt by the common occurrence of Aucella piochii and A. crassicollis in similar stratigraphic relations in both 

areas, as well as by the abundant floras which have been found in both formations 

and which are intimately associated in Oregon with both species of Au cella. It 

is not clear, however, that the Myrtle formation includes older strata that should 

correspond to the middle and lower parts of the Knox~ille. The Knoxville is 20,000 

feet thick. The Myrtle, so far as known, is but 6,000 feet thick. Diller regards this 

known portion of the formation, which rests on a basal unconformity, as the thin. 
618 INDEX TO THE STRATIGRAPHY OF NORTH A1\1ERICA. 

overlapping edge of the deposit and believes that the older sediments accumulated 

farther seaward. He says: a 

The lower portion of the Myrtle as exposed in Oregon corresponds only to the upper part 

of the Knoxville as exposed in California, yet it is quite correct to say that the Myrtle as a 

whole is the equivalent of the Knoxville and Horsetown (Shasta) as a whole, if it is admitted 

that the Myrtle includes beds which are older than any of the Myrtle yet seen in Oregon but 

which are believed to form the base of the overlapping strata. These basal beds of the Myrtle 

presumably occur farther west, beyond the present coast, but they may yet be found in Oregon. 

The age of the Myrtle formation is not yet satisfactorily determined, there 

being a difference of opinion between Stanton and Knowlton as to the correlation 

according to the faunas or the floras. The fauna as interpreted by Stanton is 

of Cretaceous age throughout. The floras as identified by Knowlton comprise a 

lower flora, of Jurassic age, and an upper flora, of Lower Cretaceous age. 

We quote Knowlton's statement of the problem and the summary of his 

conclusions: 509 

In November, 1908, Mr. Diller published a paper under the title "Strata containing the 

Jurassic flora of Oregon,"b the thesis of which he sets forth as follows: "Two fossil floras have 

been reported from the Mesozoic rocks of California and Oregon, the one Cretaceous and the 

other Jurassic. With the former the fauna is Cretaceous, but with the latter the fauna has 

been regarded as a matter of doubt. It is the purpose of this paper to remove the doubt by 

showing that in parts Qf Oregon and California the Jurassic flora * * * is in the 'Myrtle' 

and Knoxville beds, while elsewhere it extends down to the horizon of the Mariposa, and the 

general conclusion is reached that for the Pacific coast the line between the Cretaceous and the 

Jurassic is the great unconformity at the base of the Knoxville." 

The major portion of Mr. Diller's paper is devoted to proof that the Jurassic flora occurs 

in the Knoxville formation-a point conceded by the present writer. It is to the placing of 

the Jurasso-Cretaceous line at the base of the Knoxville that exception is taken. 

Mr. Diller's interpretation of the relations of the several formations concerned in this 

paper, together with his conclusion regarding the ranges of the floras and the supposedly characteristic invertebrates, is shown in the following diagram, which is taken from his paper: 

Aucella { 

crassicollis. 

" M yrtlo." i )s""'t• llorn. 

Aucella 

piochii. "Myrtle." 

~1======1 Jurassic flora. 

Dothan. 

Aucella l-··-··-·~·--·­ erring tom;. 

Galice. 

-~---

Paleozoic. 

Correlation not fully 

established. 

Horse town. 

~ <1l 

~ 

Knoxville. ~ 

w 

I FrnneL~an. (?) 

Mariposa 

(regarded= 

Monte de Oro). 

I 

Paleozoic. 

Lower 

Cretaceous. 

Jurassic. 

a Personal communication, February 15, 1910. h Bull. Geol. Soc. America, vol. 19, 1908, pp. 367-402. 
LOWER CRETACEOUS. 619 

THESIS OF THIS PAPER. 

At variance with the conclusions above set forth, it will be shown in the present paper 

that the so-called "Jurassic flora of Oregon" is everywhere of true Jurassic age, that it is practically never a found in association with the acknowledged Cretaceous flora, and finally, that 

the line between the Jurassic and the Cretaceous of the region is to be drawn through the upper 

part of the Knoxville and not at its base. 

* * * * * * * * * 

SUMMARY. 

1. The Lower Mesozoic strata of Oregon and California have afforded two floras, one of 

which is Cretaceous and the other Jurassic. These two floras, although sometimes occurring 

practically in the same section, have not been found commingling. 

2. The Cretaceous flora ranges from the extreme upper part of the Knoxville formation 

through the Horsetown formation. It embraces about 60 species of plants and is regarded as 

being of Lower Cretaceous (N eocomian) age. It fmds its closest affinity with the Kootenai of 

the Interior region, the Trinity of Texas, and the lower Potomac of the Atlantic coast. 

3. Associated with the Lower Cretaceous flora is an invertebrate fauna regarded as being 

of Neocomian age, the plants and invertebrates thus being in agreement. 

4. The Jurassic flora, which has been called the "Jurassic flora of Oregon," ranges from 

beds which have been referred to the Mariposa formation through the major portion of the 

Knoxville formation. It includes 100 species and finds its close aiiinity with the Lower Oolite 

floras of known position in other parts of the world. It is beyond question a true Jurassic flora. 

5. Associated with the Jurassic flora is a meager, often poorly preserved invertebrate 

fauna of only seven species, including the two supposedly characteristic species of Aucella 

(A. crassicollis and A. piochii). This fauna, with the exception of Aucella piochii, is the same 

as that found in association with the Lower Cretaceous flora, and it is .on account of this association that the Jurassic plant beds have been referred by some invertebrate paleontologists to 

the Cretaceous. 

6. The age of the beds containing the "Jurassic flora of Oregon" thus hinges on the relative 

strength of the evidence afforded by the flora as compared with that of the associated fauna. 

It has been shown in this paper that of a total of 100 species of plants, 47 species are known 

also from known Jurassic of other, often widely separated parts of the world. Only one of 

these 100 species has been found in the Lower Cretaceous beds of the region. The total Knoxville fauna comprises 77 forms of invertebrates, only 7 named species of which have been found 

associated with the Jurassic plants. Of these 7 species of invertebrates, only a single species 

has been found outside the limits of the Oregon-California area, and it has been further shown 

that the invertebrate paleontologists are not in accord among themselves as to the interpretation 

to be given the age determination of the fauna. The conclusion is reached that the plants, 

being thoroughly consistent, afford the better criteria, and the beds are regarded as unquestionably of Jurassic age. 

7. From the paleobotanical evidence which has been presented H follows that in this 

portion of the Pacific coast region the line between the Jurassic and Cretaceous is to be drawn 

through the upper part of the Knoxville formation, and not at its base. This line is fixed by 

the upper limit of the Jurassic flora. 

In 1895 Stanton discussed the relation of the Knoxville fauna to the Volgian 

faunas of Russia, and after citing differences of opinion among the Russian geologists as to the Jurassic or Cretaceous age of the V olgian, he wrote: 7763 

It is evident, then, that even if it were possible to refer the Knoxville to definite horizons 

of the Russian Aucella beds its age might still be questioned. One important fact that should 

a The only possible exceptions are a scrap very doubtfully identified from the area near Riddles, Oreg., and a 

·Conifer of no stratigraphic value from California. 
620 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

be borne in mind is that structurally and faunally, so far as known, the Knoxville is a unit. 

It is true that there is a gradual change in the fauna from the lower to the upper beds, but 

there is no distinct break that would justify the reference of one portion to the Jurassic and 

another to the Cretaceous. There are some elements of the fauna, such as Belemnites tehamaensis 

Hoplites storrsi, and some of the Turbinidm, that resemble Upper Jurassic types. Aucella 

piochii belongs to the same general type as A. rnosq_uensis, which has usually been referred to 

the Jurassic, and it is somewhat closely related to the Aucellm a of the Mariposa beds, but Prof. 

Pavlow informs me that Aucellm very similar to A. mosg_1tensis occur in the Neocomian of Russia 

also. These resemblances, which will be more fully mentioned in the description of the species, 

are not considered of sufficient importance to counterbalance the evidence of the Cretaceous age 

of the entire series. Some Jurassic elements are naturally to be expected in the Lower Neocomian, and it is a well-known fact that in Europe several species of ammonites pass up from 

the Jurassic to the lowest Cretaceous beds. 

Prof. Hyatt's opinion as to the Cretaceous affinities of the Knoxville ammonites has been 

cited on a previous page. That the Upper Knoxville beds containing Aucella crassicollis are 

Neocomian is shown by the resemblance of its fauna to that of the Petschora beds, now generally admitted to be Neocomian, and by its stratigraphic and faunal relations with the immediately succeeding Horsetown beds, which have been compared with the Gault by everyone who 

has studied their fauna.b The few fossil plants that have been obtained from the Knoxville 

and the Ilorsetown also tend to shew that these two formations are closely connected, and these 

plants are mostly either identical or closely related with species in the Lower Cretaceous Potomac 

formation of the eastern United States and in the Trinity beds at the base of the Comanche 

series in Texas. c 

From all these lines of evidence the conclusion is reached that the entire Knoxville series 

is of N eocomian age. 

In 1910, as this manuscript is being finished, Stanton states orally that the 

preceding quotation expresses the views he stills holds. 

J. Perrin Smith 766 does not altogether agree with Stanton, as appears from the 

following statement: 

The Cordilleran revolution began in the Great Basin sea in the middle of the Jurassic, when 

that body of water, after many vicissitudes, finally went dry, and has never since been covered 

by salt water, although in later ages Tertiary and Quaternary lakes have been scattered over 

its dead basin. 

This elevation culminated, in late Jurassic time, in the upturning and metamorphism of 

the Triassic and Jurassic sediments of the Sierra Nevada and the Franciscan beds of the Coast 

Ranges. * * * 

It is probable also that the Cordilleran revolution was something more than a mere orogenic disturbance, for it marks a change from the warmth of the Middle Jurassic, with its cycads 

and reef-building corals, to the cooler epoch of the Upper Jurassic, with its scanty boreal fauna. 

The Middle Jurassic was of tropical type, from Mexico to Alaska, and uniform up to Franz 

Joseph Land. The Upper Jurassic, on the other hand, was of boreal type from the Arctic 

region down as far as California, and for a short epoch in the Portland these conditions extended 

down as far as Mexico. 

After this mountain-making epoch near the close of the Jurassic, the sea again encroached 

on the uplifted area, and the Knoxville sediments were laid down on the western border of the 

a See comparisons by Prof. Hyatt, Bull. Geol. Soc. America, vol. 5, pp. 404-407. 

b It is not probable that the limits of the divisions recognized in the California Cretaceous coincide exactly with 

those of the European subdivisions of the Cretaceous. It has been shown (Dull. Geol. Soc. America, vol. 5, pp. 445-

449) that the Horsetown beds probably include the lowest Cenomanian, and at their base they may contain strata 

older than the Gault. 

c These pmnts are the only means by which the Lower Cretaceous of Texas and California can be compared. So 

far as known, their invertebrate faunas have nothing in common. 
LOWER CRETACEOUS. 621 

Coast Ranges. The lower Knoxville beds contain a fauna closely relateu to that of the Mariposa, still with Jurassic types of Aucella, anu with the same poverty of other animals. But 

the upper Knoxville beus, while still retaining reminiscences of the boreal region in Aucella anu 

a few other forms, show a preponuerance of life characteristic of more favorable conditions. 

Aucellas of northerly habit mingle with cephalopods that did not belong in the boreal region, 

and on the near-by land cycads abounded. The line between Jurassic and Cretaceous should 

be drawn, not at the beginning of the Knoxville, but between the lower and the upper Knoxville beds; the former belonging to the Portland and Aquilonian, while the latter belong to the 

Neocomian. 

L 10. JOHN DAY BASIN, OREGON. 

Merriam 589'

590 refers to exposures of conglomerate and sandstone on the west 

side of the John Day Basin, from which good collections of fossils were obtained. 

The outcrops appear to form opposite sides of a syncline, and include 3,000 or 4,000 

feet of beds. The lower strata are said to "exactly duplicate" those of the Knoxville as it is usually developed in California and southern Oregon. Stanton has 

identified the Chico fauna in Merriam's collections. 

L 12. SOUTHWESTERN AND CENTRAL MONTANA. 

F. C. Calkins contributes the following notes from a manuscript for a folio on 

the Philipsburg quadrangle, Montana: 

Both Lower anu Upper Cretaceous are represented in the Philipsburg quadrangle, although 

they have not yielued very satisfactory fossils. The Lower Cretaceous is represented by the 

Kootenai formation, which may be described as follows: 

The yellow-weathering beds of the Ellis formation are generally overlain by a heavy reddish 

sandstone, locally conglomeratic with well-rounded pebbles of quartzite like the Quadrant, 

which is taken to be the base of the Cretaceous. This bed is generally succeeded by argillaceous 

buff-weathering limestones, in the upper part of which have been found poorly preserved specimens of the fresh-water gastropod Goniobasis which, according to Dr. Stanton, tend to indicate 

a Kootenai age. Above these there are several hundred feet of maroon and gray-green sandstones and shales that have yielded no fossils. Near the top is a bed or several beds of gray 

limestone crowded with shells of fresh-water gastropods. These gastropod limestones, which 

are very conspicuous in the vicinity of Drummond, on the Northern Pacific Railway, seem to 

be very widespread and highly characteristic of this horizon. They are probably the same 

as those that in the Yellowstone National Park were referred to the Dakota. Above the gastropod limestones are a few feet of calcareous shale and sandstone. On Mount Princeton, in 

the Philipsburg quadrangle, there is a gradation to the black noncalcareous shales of the 

Colorado formation; elsewhere the transition is more abrupt. 

These uppermost limestones have yielded two or more undescribed unios, one related to 

U. douglassi Stanton, Goniobasis? increbescens Stanton, and Viviparus ~ sp. The fauna is 

characterized by Dr. Stanton as probably upper Kootenai. 

The total thickness of the beds referred to the Kootenai is about 1,500 feet. 

The Cretaceous of the Great Falls coal field extends along the northern and 

>northeastern flanks of the Belt Mountains. The Lower Cretaceous is represented 

by the Kootenai formation and the Upper Cretaceous by Colorado and Mon:tana 

strata. The Morrison formation, which is doubtfully referred to the Jurassic by 

Stanton and others, is described under the Lower Cretaceous by Fisher, 332a who 

states: 

The Morrison formation, which is extensively exposed along the Rocky Mountain Front 

Range in southern Montana and Wyoming, is also believed to occur along the northern base of 
622 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

the Little Belt Mountains. In previow; investigations in this field by Weed and others the 

Morrison formation has not been recognized, and the beds comprising it have been grouped 

with the Kootenai and included in the "Cascade" formation. During the last field season 

dinosaur bones provisionally regarded by C. W. Gilmore as of Jurassic age were found at one 

horizon in many different localities; and at one exposure in sec. 3, T. 16 N., R. 2 E., about 30 

feet below the bone-bearing bed, a green shale containing a distinctly fresh-water fauna later than 

the Ellis formation was seen. These rocks, here provisionally regarded as constituting the 

Morrison formation, consist of sandstone and bright-colored sandy shale with scattered layers 

of impure limestone, many of them in lenticular form. The formation lies with apparent conformity on the Ellis and is overlain conformably by the Kootenai. The thickness ranges from 

60 to 120 feet, but the exact limits of the formation are in many places difficult to determine. 

Fragments of bone have been found at different horizons throughout the overlying Kootenai 

formation, but thus far none that are sufficiently well preserved for specific determination 

have been discovered in this region. It is possibl~ that future investigation may prove that the 

rocks here tentatively regarded as belonging to the Morrison constitute in reality a basal member 

of the Kootenai. 

Section of supposed Morrison formation on the north side of Smith River, Montana. 

Kootenai formation. 

Morrison formation: Feet. 

Shale, soft, sandy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 

Limestone, light-colored, nodular....................................................... , 4 

Shale, variegated............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 

Sandstone, gray, massive.................................... . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 

Shale, greenish gray, sandy............................................................. 20 

Ellis formation. 

120 

Fisher gives other sections of the supposed Morrison and states that the rocks 

have yielded invertebrate fossils which Stanton regards as "a fresh-water fauna 

later than the Ellis and suggestive of the Morrison." 

In regard to the character and extent of the Kootenai, Fisher has the following 

to say: 

The Kootenai, as determined by the present investigation, comprises the upper one-third 

of the Cascade and Dakota and the basal red shale included in the Colorado shale, as described 

by Weed in the Fort Benton folio. * * * 

[This formation] consists of alternating layers of sandstone and shale, with the former 

predominating, especially in the lower half. The sandstones range in thickness from 10 to 60 

feet and are more or less massive in character. In the upper part shales are more abundant 

and are interbedded with thin layers of impure sandstone. At Belt, on the east side of Belt 

Creek, where a complete section was measured, the basal member of the formation consists of 

a sandy shale interbedded with sandstone, the latter predominating, the whole having a thickness 

of about 60 feet. This member consists locally of firm, massive sandstone with only a small 

percentage of shale. It is ovorlain by coal, which here has a thickness of 6 feet, including 

a few thin partings. Above the coal there is a dark coaly shale 5 to 6 feet thick, covered by 38 

feet of massive light-gray sandstone. This sands.tone is overlain by 138 feet of beds, consisting 

in ascending order mainly of alternating layers of sandstone, red shale, and clay, with an 

occasional limestone lens in the lower part. Above this alternating series there is about 200 

feet of red shale, which constitutes the topmost member of the formation. The total thickness 

is about 450 feet, which may be regarded as representative of the Kootenai formation as exposed 

along the Belt Creek valley. * * * 

During the present investigation a number of detailed sections measured along Belt Creek 

proved conclusively that the stratigraphic interval between the base of the Ellis and the 
LOWER CRETACEOUS. 623 

Kootenai coal, to which Weed had assigned a thickness of 736 feet. IS in reality only about 300 

feet. According to the present classification the lower 120 feet of these beds has been assigned 

to the Ellis; an equal thickness immediately overlying, in which fresh-water invertebrates and 

land animals occur, to the Morrison; and the upper 60 feet, which is plant bearing, to the 

Kootenai. * * * 

The Kootenai has the greatest areal distribution of all the formations outcropping within 

the area. It caps the surface for a great part of the district lying between Smith River and 

Belt Creek and is the surface formation of the high plateaus south of Otter Creek. Beyond 

Otter Creek it is exposed as a band of varying width which narrows toward the east. 

Fisher gives columnar sections measured along the Belt Creek valley which show 

the character and thickness of the several formations. As to fossil evidence and 

correlation he states: 

The Kootenai formation of the Great Falls district carries an abundant fossil flora of Lower 

Cretaceous age. Fossil plants of Kootenai age were first discovered in the Great Falls coal 

field in 1889 by J. S. Newberry. From these fossils, which consisted of only a few species, it 

was possible to correlate the rocks of the Great Falls region with the Kootenai north of the 

international boundary line, described by George M. Dawson. * * * 

During the present investigation fossil plants, all of which were studied and reported on 

by F. H. Knowlton, were collected from five different horizons-15, 60, 70, 150, and 300 feet 

above the base of the Kootenai formation. * * * The collection * * * is not large, 

but it is of unusual interest in that it contains a number of species before unknown in the 

Kootenai beds of this age; it contains also a species of the genus Protorhipis not previously 

found in North America, as well as some believed to be new to science. 

In addition to the plants, some fresh-water invertebrates were collected from the upper 

part of the Kootenai during the investigation. * * * These fossils are too imperfect for 

positive identification, but the species with which they are compared occur a few miles south 

of Harlowton, Mont., in beds that belong to either the Kootenai or the Morrison. 

M 10. WASmNGTON AND BRITISH COLUMBIA. 

A helt of Cretaceous strata crosses the international boundary from Washington 

into British Columbia. The rocks were described by George Otis Smith 757a in 1904 

and by Camsell 129 in 1907. The following is quoted from Smith's account of the 

eastern belt on Pasayten River. Camsell's description is briefer and to the same 

effect. 

Prof. Russell, in his reconnaissance of 1901, examined an assemblage of folded sedimentary ' 

strata in the neighborhood of Barron and Crater Pass. a From these rocks he collected fossils 

which are commented on in the following extract from his report: 

"A thick bed of bluish sandstone at the base of Gold Ridge, penetrated by the tunnels of 

the St. Paul and Minneapolis mines, contains fossil ferns and nearly upright tree trunks. One 

sample of fern collected has been determined by F. H. Knowlton as approaching closely 

Dryopteris mrstedi, from the Cretaceous rocks of Greenland. A siliceous limestone in the same 

ridge, but several hundred feet higher in the series and extending southward to the border of 

Crater Pass, is abundantly charged with bivalve shells, which, as determined by T. W. Stanton, 

are of a species of Actreonella. The evidence furnished by the fossils just mentioned indicates 

a Cretaceous age." 

The authors of this paper found that these Cretaceous beds extended eastward along their 

route to the Hidden Lakes and were very extensively developed to the north, and believe that 

they extend west to a point not far above the mouth of Granite Creek. In this, however, they 

differ from Prof. Russell, who believes that the slaty rocks with steep dips exposed along lower 

a Russell, I. C., Geology of Cascade Mountains: Twentieth Ann. Rept. U.S. Geol. Survey, pt. 2,1900, pp. 114-117. 
624 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Slate Creek and Ruby Creek arc much older than the Cretaceous.a * * * The authors do 

not consider that the assumption of the pre-Cretaceous age of these beds is justified and have 

provisionally considered them as belonging in the same formation with those at Barron. 

To the rocks of this locality which he recognized as Cretaceous Prof. Russell provisionally 

applied the name Similkameen formation.b This name was, however, applied ten years earlier 

by Dawson to a Miocene formation in British Columbia.c * * * 

The Pasayten formation is composed of sedimentary rock::-. without contemporaneous volcanic materials. East of the main fork of Pasayten River- sandstone appears to be the dominant rock. * * * The lowest part of the section, as seen along the crest of the Hozomeen 

range, includes at least 1,000 feet of black shale. Above this shale is a sandy conglomerate, 

with pebbles from 1 to 8 inches in diameter. * * * Sandstone overlies the conglomerate 

and is succeeded by more black shale. The steep dips here indicate the presence of a great thickness of these rocks, * * * so that 6,000 feet would appear to be a very conservative estimate for the thickness of the Pasayten formation. 

There are a few thin and discontinuous beds of limestone in the Pasayten formation, but 

they constitute only an insignificant proportion of its total volume. Along the lower portion 

of Slate Creek the supposed Cretaceous rocks are mainly black indurated shales with nearly vertical dips. 

The argillaceous portions of the Pasayten formation are generally dark-colored, distinctly 

bedded shales. They are often siliceous and in general more or less indurated, and are popularly referred to as "slate." * * * 

The sandstones, while occasionally quartzitic, are more commonly gray or greenish gray in 

color, and evidently composed in large part of feldspar and rock fragments. The conglomerates 

contain a variety of pebbles, including several granitoid rocks, gabbro, diabase, metamorphosed 

volcanics, chert, quartzite, and vein quartz, illustrating the character of the pre-Cretaceous 

formations of the region . 

. The whole series has undergone a considerable degree of "static" metamorphism, as shown 

by the generally thorough cementation of the sandstones-and the presence of joints in all the 

varieties of rocks. Both these phenomena are exemplifie<i strikingly in the conglomerates, 

which often are divided into great blocks whose faces are nearly as smooth as if made by a saw 

that had cut indifferently through the pebbles and their compact matrix. 

The series is cut by many dikes and sheets of igneous rock; these are especially numerous 

along the main divide, where they must add materially to the volume of the formation. At three 

localities there are exposures of granitoid rock, apparently intrusive in the Pasayten formation. 

M 11-12. CANADIAN ROCKIES, ALBERTA AND BRITISH COLUMBIA. d 

The Cretaceous areas in the Canadian Rockies are best known as the Cascade 

and CrowsNest Pass coal fields. Dawson stated that in this region dark Cretaceous 

shales in apparent conformity succeed Carboniferous shales, which are lithologically similar, but the Fernie shale (Jurassic) has since been distinguished. The Cretaceous consists of shales, sandstones, conglomerates, and coals, to a total thickness 

of 12,000 feet or more. It comprises the Kootenai formation (Lower Cretaceous), 

a local volcanic intercalation, and Upper Cretaceous strata. Dawson's original 

description 255a runs in part: 

Over the area of the Great Plains, both in the United States and Canada, and in the Rocky 

Mountain region south of this district, the lowest rocks of the Cretaceous series developed are 

those of the Dakota, of Middle Cretaceous age. In the vicinity of the west coast Lower Cretaa Russell, I. C., op. cit., p. 112. 

b Idem, pp. 114-ll7. 

c Dawson, J. W., Proc. and Trans. Royal Soc. Canada, vol. 8, sec. 4, 1890, pp. 75-91. 

d For the Cretaceous of the plains in this latitude see p. 695. 
LOWER CRETACEOUS. 625 

ceous rocks are found, and in this part of the mountains we appear to enter upon the edge of the 

area of deposit of the Lower Cretaceous, the beds here named the Kootanie series occupying 

that horizon. The geological horizon of the Kootanie series is determined by its position 

relatively to the higher members of the Cretaceous series, and by.the fossil plants which it has 

yielded. * * * The plants ''consist of ferns, cycads, and conifers, some of them identical 

with or closely related to those of the Jurassic of the Amur country in Siberia, and others 

similarly related to the Lower Cretaceous of Greenland, as these floras have been described 

by Hecr. This group undoubtedly represents the flora of the Lowest Cretaceous, which has 

not hitherto been recognized in western America." * * * That the series characterized by 

these plants is a widespread and important one is shown by the fact that one of the species 

(Pinus suskwaensis) had previously been found on Suskwa River, in northern British Columbia, 

at a distance of 580 miles northwest of the most northern locality here referred to. 

* * * * * * * * * 

No complete section can yet be given of the Cretaceous rocks of the mountain region, nor 

of those of the adjacent foothills. * * * Two horizons appear, however, to be :fixed with 

considerable definiteness in the lower part of the Cretaceous of the mountains-that of the 

most important and persistent coal scams and that of the volcanic intercalation. The first of 

these is fixed in part by the similarity of appearance and character of the coal and beds near 

them, but chiefly by the very similar group of fossil plante which is found in association with 

these coal seams. 

* * * * * * * * * 

The thickness of the rocks of the Kootanie series below this coal-bearing horizon was estimated on the Crow Nest Pass and near the west summit of the North Kootanie Pass at about 

7,000 feet, which may be taken as a minimum estimate of the greatest observed development 

of this part of the series. The beds are chiefly shales and sandstones of very varied texture and 

appearance. 

The volcanic ash beds and agglomerates of the Cretaceous, in this region, are evidently due 

to local eruption, which had its center in the latitude of the Crow Nest Pass. These volcanic 

rocks have, however, been traced north and south from this point over a total length of 45 

miles, and may probably have at one time had as great an extension east and west, though this 

has subsequently been diminished by the folding together of the beds. The volume of the strata 

between the coal-bearing horizon and the base of the volcanic rocks on the Crow Nest Pass was 

estimated approximately at 3,350 feet, on the South Kootanie Pass at 2,400. The mean of 

these approximations, 2,750 feet, may for the present be adopted as a probable result. The 

volcanic rocks themselves, on the Crow Nest Pass, where they attain their maximum, have a 

volume of about 2,200 feet, but thin out very rapidly to the north and south. 

The summit of the Kootanie series is not yet precisely defined but is situated between the 

apparently constant coal-bearing horizon and the base of the volcanic beds, as, on theN orthwest 

Branch of the North Fork, fossil plants believed to represent the horizon of the Dakota are 

found a few hundred feet below these volcanic beds. 

(See also M 11, Chapter XIII, p. 574.) 

M 10, N 9-10, 0 9. WESTERN BRITISH COLUMBIA. 

The Jackass Mountain group, so called by Selwyn from the locality of that 

name on Fraser River (near the mouth of the Thompson~), is described in his 

report 724 as consisting of "hard, close-grained, and thick-bedded greenish sandstones or quartzites, green and black shales, and, above these, massive, thick-bedded 

pebble conglomerates, dipping generally at low angles in various directions; some 

of the inclosed pebbles are of rocks belonging to the Cache Creek series." 

In 1875 Dawson 249a identified these rocks on Tatlayoco Lake (longitude 124° 

30', latitude 51° 30'), where they have the character of the strata on Jackass Moun480110--12----40 
626 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

tain, and he found fossils by which the age was "determined as lower Cretaceous 

of the horizon of the Shasta group of the California geologists." He says further: 

Along the eastern shore of the lake these rocks, as already mentioned, ~tppear to overlie 

those of the Porphyrite series. * * * The series is no doubt conformable throughout, the 

upper beds * * * showing, however, a greater development of conglomerates. The rocks 

may be described as being compact bluish-gray quartzites or hard sandstones and conglomerates 

of all grades in regard to size of particles, associated with blackish or dark-colored slaty and 

shaly beds, which recur frequently at different horizons. Great fragments of highly fossiliferous 

quartzite strew the lower slopes in some places, but fossils were only observed in situ about 

2,000 feet above the lake, where they are found not only in the quartzite but in black shaly 

beds. * * * It is highly probable that softer shaly beds may bear a larger proportion to the 

quartzites than now appears, as there are extensive hollows following the strike in which no 

exposures occur. Many of the beds are somewhat calcareous, and some of the shales are dark 

colored from carbonaceous matter. Together with the marine fossils, in some layers surfaces 

are found covered with obscure plant impressions, like fragments of stems or bladelike leaves. 

No indications of coal were, however, observed. The thickness of the entire series, as shown on 

the east side of Tatlayoco Lake, probably does not fall short of 7,000 feet. 

In 1877 Dawson 251 reexamined the Jackass Mountain rocks in the type locality 

and found "Syncyclonema meekiana Wh., Ancyloceras percostatus Gabb, Crioceras 

latus Gabb, Pleuromya n. sp. allied to P. papyracea Gabb, an Area * * * and 

a badly preserved cast of a Cuculhea." These fossils confirm the correlation with 

the rocks on Tatlayoco Lake.a 

The small basin of the Jackass Mountain occurrence, above described, is crossed 

by the fiftieth parallel. That of Tatlayoco Lake is the south end of a large area 

which widens toward the north and extends nearly to latitude 58°. A section along 

Skeeha River and across the mountains to Babine Lake, near the fifty-fifth parallel, 

is described by Dawson. 253 Referring to the rocks cut by the Skeena and its tributaries, he notes that they are chiefly feldspathic rocks of purplish, grayish, greenish, 

or bluish tints. They "are sometimes brecciated, and the breccias occasionally 

pass into water-formed conglomerates, with well-rounded fragments, the finer 

materials graduating into ordinary quartzites, sandstones, and argillites by intermediate varieties. Fossils were found in some abundance in a bluish feldspathic 

rock. * * * They include belemnites, a Trigonia, with other mollusks and a 

branching coral." 

Near Kitseguecla the rocks change somewhat in character. The sandstones are not highly 

indurated, as before, but rather soft, and associated with carbonaceous shales, which occur at 

different stages in the formation and are sometimes 10 or more feet in thickness. At a little 

distance these quite resemble coal seams, and on closer examination are in fact found to include 

films and small lumps of a material, which, though very impure and ashy, may be called true 

coal. Ironstone in nodules and sheets occurs in abundance in some parts of the formation, 

and obscure plant impressions were observed in the sandstones. The rocks have been irregularly 

deposited in many instances, the carbonaceous sha.les in particular showing a tendency to 

lenticular forms. * * * 

It will have been observed that while the porphyrite and other feldspathic and often 

brecciated rocks prevail toward the western margin of the region, comparatively soft sandstone, 

argillites, and carbonaceous argillites characterize the eastern, the intervening region showing 

rocks more or less intermediate in lithologic character and degree of induration. * * * 

a This list indicates correlation with the Horsetown of California.-T. W. Stanton. 
LOWER CRETACEOUS. 627 

In proceeding eastward from the forks to the northern end of Babine Lake, across the 

intervening mountain region, similar rocks continue to prevail. Sandstones are most abundantly represented but contain in some places carbonaceous shales and toward the summit of 

the pass become associated with rocks of volcanic origin like those before described. These 

occasionally seem to form fully one-half the thickness of the beds represented. In one place 

5 miles up the Suskwa River a few impressions of leaves were found. Some of these appear 

to be coniferous. There is one narrow angiospermous leaf and several grasslike blades. Not 

far from the summit numerous fragments of silicified wood were obtained, with a few specimens 

of a mollusk which, according to Mr. Whiteaves, who has examined the specimens, is a Thracia 

of the section Corimya. The species is probably undescribed, but it is identical with one from 

the coal-bearing rocks of the Queen Charlotte Islands. 

In 1875 Dawson 249 distinguished in southwestern British Columbia a great 

body of volcanic rocks and pyroclastic tuffs under the name "Porphyrite group." 

He says: 

Porphyrite group.-This name may be provisionally employed to designate a series of rocks, · 

chiefly feldspathic and often porphyritic, though also including diorites of varied texture, the 

reference of which to any of the groups formerly defined seems uncertain. They are best 

seen about Tatlayoco Lake, where they overlie unconformably the Cascade crystalline rocks 

and appear to underlie the beds of the Jackass Mountain series. The whole of the rocks of 

this group seem to be of igneous origin, though some of them may owe the arrangement of 

their material to water. 

After the field work of 1876 Dawson 250 wrote: 

It may now, however, be affirmed with considerable certainty that the rocks called the 

Porphyrite series in last year's report underlie, probably conformably, the fossiliferous series of 

Tatlayoco Lake and consequently bear the same relation to tho Jackass Mountain beds of the 

preliminary classification. This inference is chiefly based on the fossils discovered on the 

lltasyouco River, described by Mr. Whiteaves in an appended note. 

* * * * * * * * * 

The most interesting and typical sections of these rocks examined last summer are those 

in the vicinity of Iltasyouco and Islaho or Salmon rivers. The rocks here seen represent those 

described last year on Tatlayoco Lake, and though they have not been again observed in contact 

with the upper arenaceous and conglomerate beds of the Tatlayoco Lake sections, the discovery 

of fossils on the Iltasyouco River, of a horizon close to though probably lower than that of the 

Jackass Mountain group, together with additional evidence tending to show the blending of the 

ordinary aqueous sediments of the upper part of the Jackass Mountain series with the igneous 

products of the Porphyrite series, leaves little room for doubt that the latter is the downward 

continuation of the former, and that the whole constitutes a formation, bridging to some extent 

the gap ordinarily found between the Cretaceous and Jurassic. 

Detailed sections and descriptions of these rocks, which exceed 2,000 feet in 

thickness, are given on pages 59 to 72 of Dawson's report. 

Whiteaves 911 reports on the fossils from the "Porphyrite group" of Iltasyouco 

River and closes with the following comment on correlation: 

The fossils above enumerated are of much interest as affording the first instance yet observed 

of the occurrence of a well-marked fauna of Jurassic age in British Columbia. It is true that 

fossils, probably from a very similar geological horizon, were collected by Mr. Selwyn in 1875, 

at Rock Island Gates, below Hudson's Hope, on the Peace River, but these specimens, which 

wore described in the report of progress for 1875-76, are very few in number and so imperfect 

that none of the species could be satisfactorily determined. 
628 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

If the identifications in the present paper be correct, it would appear that nine of Meek 

and Hayden's species, from the Jurassic rocks of Dakota, are found also in the Coast Range of 

British Columbia. These are: 

Gryph::ea calceola var. nebrascensis. 

Camptonectes extenuatus. 

Eumicrotis curta. 

Modiola (Volsella) formosa. 

Modiola (Volsella) pertenuis. 

* * * * * 

Grammatodon inornatus. 

Astarte fragilis. 

Pleuromya subelliptica. 

Planorbis veternus. 

* * * * 

Trigonia dawsoni and Astarte ventricosa, from the Iltasyouco River, are also found in the 

Jurassic rocks of the western slope of the mountains in Nevada; and it may be that there is no 

physical or geographical break between the coast range of British Columbia and the Sierra 

Nevada. Mr. Gabb has pointed out that the .Jurassic fm;sils of Nevada are probably of the age 

of the Lias, and some of the Iltasyouco lamellibranchs, as has already been stated, are barely 

distinguishable from European Liassic species. On the other hand, the few ammonites collected by Mr. Dawson, so far as very fragmentary specimens enable one to judge, appear to be 

conspecific for the most part with well-known forms from the English Inferior Oolite, though 

one, which has been doubtfully referred to Perisphinctes anceps, may indicate a horizon as high 

as the Oxford Clay or Coral Rag. On the whole, however, the evidence, as far as it goes, is in 

favor of the supposition that these fossils from British Columbia belong to the lower rather than 

to the upper part of the Jurassic series. 

Subsequently Whiteaves 9r

8 modified this conclusion in favor of a later age for 

the rocks in question. He says: 

Certain rocks described by Dr. Dawson in the report of progress of the Geological Survey of 

Canada for 1876-77, and there referred to as the "Porphyrite series," occur on Sigutlat Lake and 

the Iltasyouco River, which flows from Sigutlat Lake into the Dean or Salmon River. The 

fossils collected from these porphyrites were reported upon provisionally by the writer in an 

appendix to Dr. Dawson's report. They were then regarded as possibly of Jurassic age, on 

account of their resemblance to the fossils of the so-called Jurassic rocks of the Black Hills of 

Dakota, but arc now believed to be Cretaceous. 

The collections of fossils that have been made from the Cretaceous rocks at Quatsino Sound~ 

Vancouver Island, in 1878 and 1885, and at various localities off the coast or on the mainland 

of British Columbia between 1875 and 1888, have led to the conclusion that the Aucella-bearing 

rocks and Jackass Mountain series of that province are not older than but of about the same 

age as the Queen Charlotte Island formation, and that the porphyritic rocks of Sigutlat Lake and 

the Iltasyouco River are of the same age and not altered Jurassic sediments. 

N 8-9. QUEEN CHARLOTTE ISLANDS. 

The Cretaceous or coal-bearing rocks of Graham Island, the northern member 

of the Queen Charlotte group, are described by Ells/16b who, however, confines 

his account largely to local details and refers to Dawson for a general discussion. 

Dawson, 252b following Richardson, 671a distinguished the following strata: 

A. Upper shales and sandstone~ .................................................... . 

B. Coarse conglomerates ........................................................... . 

C. Lower shales with coal and iron ore ............................................... . 

To these he added : 

Feet. 

1,500 

2,000-3,000 

1,800-5,000 

Feet. 

D. Agglomerates of volcanic origin ........................................................ 3,500 

E. Lower sandstones ........................................................•............. 1,000? 
LOWER CRETACEOUS. 629 

The upper shales (A) are generally arenaceous and interstratified with sandstones from 3 to 6 inches thick. A bed of sandstone 30 feet thick occurs 70 feet 

above the base, and the lowest shales are interstratified with reddish-weathering, 

grayish-brown dolomite, which constitutes the chief part of the mass and seems to 

form a passage to the underlying conglomerates. The shales have yielded but one 

recognized fossil, "Inoceramus problematicus." a 

The conglomerates (B) include for the most part well-rounded pebbles, in some 

layers several inches in diameter, derived from the more or less crystalline preCretaceous rocks; rounded shaly fragments of the next underlying Cretaceous are 

also found, indicating slight erosion, but no true unconformity, during the deposition 

of the conglomerate. Gray and yellow sandstones are interbedded and the upper 

part of the conglomerate is dolomitic. 

The lower shales and sandstones, at the base of which the anthracite coal is found, consist 

of blackish or gray shales, interbedded with gray or yellowish-gray sandstones and numerous 

l·ayers composed of sandy argillaceous material, intermediate in character between shale and 

sandstone. The bedding is generally regular and certain zones are characterized by large 

calcareous nodules, generally lenticular, and occasionally several feet in diameter or even 

coalescing to form sheets of calcareous matter. Layers so coarse as to be called conglomerates 

scarcely occur. The beds immedit1tely underlying the conglomerates of subdivision B are 

generally gray shales, very regular in their bedding, and quite hard. Below these is a considerable thickness of strata in which shaly beds usually preponderate, while toward the base 

of the subdivision sandstones are more important. The lowest beds are of interest as being 

those in association with * * * the coal. * * * 

Subdivision C rests on a serieR of volcanic rocks constituting subdivision D, which apparently forms a member of the same formation. The upper surface of the agglomerate and ash 

rocks of D must, however, have been an irregular one, and to its undulations the lower beds of 

C more or less closely conform. The appegrance at the junction of subdivisions C and D is 

therefore that of an unconformity more or less marked. * * * This partial unconformity 

is, however, believed to be essentially unimportant and only such as might be anticipated at 

the junction of two classes of deposits so dissimilar. * * * The occurrence of fossils identical with those of subdivision C in beds below the volcanic horizon, with the inclusion of marine 

forms in some parts of the upper portion of the rocks of volcanic origin (at points on the east 

side of Alliford Bay), serve to show the continuity of the conditions of deposit. 

The passage beds have been observed in a number of localities to be coarse feldspathic or 

tufaceous sandstones, generally pale in color and formed apparently by the rearrangement of 

the still unconsolidated materials of the upper beds of D. These vary in thickness but are 

generally associated with black carbonaceous argillites, which are sometimes shaly and at the 

Cowgitz mine hold the seam of anthracite coal. 

* * * * * * * * * 

[The agglomerates which constitute subdivision D] are almost exclusively of volcanic origin, 

though some layers show traces of water action in the rounding of fragments. Some beds may 

have been flows of molten matter, but most are of a fragmental character, either agglomerates 

or tufaceous sandstones, of greenish, grayish, brown, or purple tints. * * * The material 

is almost everywhere predominantly feldspathic, and some specimens resemble typical 

porphyrite of rather coarse grain. At the east side of the point north of Alliford Bay, hard 

dark tufaceous sandstones are found graduating into agglomerates, some of which, however, 

have their fragments so well rounded as to be more appropriately designated conglomerates. 

aJ. labiatus.-T. W. Stanton. 
630 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Many layers here become calcareous from the inclusion of organic remains, of which some are 

evidently shells, though too poorly preserved for recognition, except in the case of one or two 

specimens, which appear to be Ostrem. 

The base of the Cretaceous consists of tufaceous beds with ordinary sandstones 

and calcareous layers that contain many fossils. "These, while in some cases 

specifically identical with those of subdivision C, include a few species not yet found 

in that part of the section, and thus present a general facies somewhat different 

from it." 

The fossils from the Cretaceous of the Queen Charlotte Islands are described by 

Whiteaves. 923 

Dawson discussed the relations of the Queen Charlotte group and the Kootenai 

(Lower Cretaceous) of British Columbia, and reached the conclusion that "The 

very important fact is established of the existence of an identical earlier Cretaceous 

horizon on the west coast, and in and even to the east of the eastern range of the 

Cordillera system.'' 

Stanton states (orally) that Dawson's reasoning was based chiefly on marine 

mollusks occurring below the plant-bearing beds of the Kootenai, in the Fernie 

formation, which is now assigned to the Jurassic. (See Chapter XII, under N 8-9, 

table of formations by Dawson, p. 540.) 

N 9. TELKWA RIVER DISTRICT, BRITISH COLUMBIA. 

Near the center of the large area mapped as Lower Cretaceous in British 

Columbia is Telkwa River, which traverses a district surveyed by Leach, 527 who 

thus describes the rocks of Dawson's "Porphyrite group" and the overlying coalbearing strata: 

Rocks of the Porphyrite group occupy by far the most extensive area in this map sheet. 

They consist of a great series of volcanics, composed of tuffs, andesites, agglomerates, etc., 

more often occurring in sheets as volcanic :flows but frequently showing evidences of deposition 

under water, more particularly toward the top of the series, and are all more or less regularly 

bedded. 

* * * * * * * * * The rocks of this group vary greatly in appearance in different parts of the field, in color 

ranging from light greenish grays to dark purplish reds. Generally speaking it may be said 

that red colors predominate toward the top of the series, the beds consisting of reddish andesites, 

breccias, and tuffs, in many cases amygdaloidal, with inclusions of calcite and zeolites. Green 

is the characteristic color toward the base, the beds being composed largely of fine-grained 

greenish feldspathic rocks, often amygdaloidal and containing much calcite and epidote. * * * 

Immediately overlying these rocks, and possibly unconfonnable to them, although both 

have been subsequently folded and faulted to such an extent that their immediate relationship 

to one another is somewhat doubtful, occurs a series of beds composed chiefly of clay shales and 

containing a number of important coal seams. The lower member of these beds consists of a 

coarse, loosely cemented conglomerate, mainly composed of pebbles from the underlying volcanics, in places shading into a coarse grit and not more than 60 feet in thickness in any place 

seen. * * * This is followed by some thin-bedded clay shales with a few soft, thin, crumbly 

beds of light-colored sandstone, succeeded by more clay shales and coal, carrying numerous 

yellow-weathering clay-ironstone nodules. These are the youngest sedimentary rocks represented in the district, and [are] not of great thickness (in no case seen showing more than 300 

feet in all). * * * 
LOWER CRETACEOUS. 631 

A few fossil plants were collected from the coal-bearing beds of Goat Creek, [among] which 

* * * Prof. Penhallow [identified] * * * Gleichemia gilbert-thompsoni Fontaine. Along 

the international boundary line, on the Skagit River, * * * Daly obtained the same species 

[which is thought to indicate a Lower Cretaceous age]. 

N-0 4. ALASKA PENINSULA. 

The Mesozoic area in the Alaska Peninsula includes Cretaceous as well as 

earlier Mesozoic rocks. Stanton and Martin summed up their general conclusions 

as quoted on page 57 4, Chapter XIII. Their statement in regard to the Cretaceous 575 is as follows: 

The presence of the Russian type of Lower Cretaceous on the Alaska Peninsula is suggested by the occurrence of Aucella related to A. crassicollis at Port Moller and Herendeen Bay, 

where Jurassic types of Aucella also occur in other beds, but the details of the stratigraphy are 

unknown. These beds, with Aucella cf. crassicollis, comparable with the Upper Knoxville 

beds of California, are widespread in Alaska, though we found no indication of them at any 

localities studied by us. The species was obtained by Mendenhall on Bubb Creek, a branch 

of the Taxlina, in the Matanuska series; by Spurr in the Oklune series on the Kanektok near the 

mouth of the Kuskokwim; by Schrader in the Koyukuk and Anaktuvuk series in northern 

Alaska, and by Wright on Admiralty Island, southeast Alaska, where Aucella piochi, another 

Lower Cretaceous species, was found at a neighboring locality. It also occurs in the Mission 

Creek series on the Yukon. The geographic distribution of these Cretaceous Aucella beds is 

thus seen to differ radically from the distribution of the Naknek formation with its Jurassic 

Aucellrn, and this is regarded as evidence of a probable unconformity between them. 

On Chignik Bay Upper Cretaceous rocks, closely associated with plant-bearing Kenai beds, 

occur on the lagoon 1 to 2 miles northeast of the Alaska Packers Association cannery and on 

Whalers Creek, 5 miles west of the same place, where they apparently include a workable coal 

bed. The exposures at the first locality consist of several hundred feet of shales and sandstones with some thick beds of coarse conglomerate in the middle portion. The beds beneath 

the conglomerate contain great numbers of fossil plants, a collection of which yielded * * * 

Upper Cretaceous species identified by Dr. Knowlton.a * * * 

The shales above the conglomerates yielded * * * fossils [which] indicate correlation 

with a horizon in the Chico as developed in California and Vancouver Island, which includes 

practically all of the Upper Cretaceous, but the beds at Chignik are probably not older than 

basal Senonian. 

Beds of possibly the same age occur on the north shore of the small bay north of Aievak or 

Douglas village, where there is a series of shales and sandstones with an estimated thickness of 

2,000 feet. * * * 

The Cretaceous beds at Chignik may be directly correlated with those on the Yukon near 

Nulato, and less certainly with those on the Anaktuvuk, in northern Alaska, which are the only 

occunences of Upper Cretaceous hitherto reported in the Territory. 

It is probable that more detailed study will reveal considerable areas of Upper Cretaceous 

rocks on the Alaska Peninsula, but their recognition in rapid reconnaissance is made difficult 

by the fact that lithologically they resemble the Eocene Kenai beds of the same region, which, 

like the Upper Crfftaceous, are coal-bearing and contain fossil plants of similar general types. 

* * * There are doubtless unconformities both below and above the Upper Cretaceous of this 

region, since all of the Lower Cretaceous is lacking at most localities, and at some places the 

Kenai rests directly on the Jurassic. 

a For list of species see the work cited.-B. W. 
632 INDEX TO THE STRATIGRAPHY O:F' NORTH AMERICA. 

Atwood42 a reports on the Jurassic and Cretaceous of the Alaska Peninsula as 

follows: 

i 

Age. 

I ---- --------

Upper Cretaceous .... 

Lower Cretaeeous .... 

Upper Jurassic ....... 

Geologic sequence in western part of Alaska Peninsula. 

Geographic distribu- Lithologic character. tion. 

Chignik and Heron- Conglomerate, sandstone, and 

deen bays. shales, with coal seams. 

Herendeen Bay ....... Shale, sandstone, and calcarc- ous sandstone. 

Chignik and Heren- Sandstones, conglomerates, 

deen bays. and arkose. 

I 

Thickness Remarks. (feet). 

I 

! --~ 

600+ I Contains valuabl 

beds at Chigni 

Herendaen bays 

1,800+ I 

c coal 

k and 

l,OOO+ 

I ··-· 

The Upper Jurassic sediments are * * * dense, fine-grained sandstones of bluish 

color, conglomerates, shales, and arkose. They are the oldest sedimentary rocks exposed in 

either the Chignik or the Herendeen Bay districts. * * * The Chignik localities have 

yielded several collections of invertebrate fossils whose age has been determined by Stanton. 

The Upper Jurassic beds in Pinnacle .Mountain, Herendeen Bay, are overlain by Cretaceous 

rocks and both have been folded, truncated, and in part covered by volcanic material, which 

issued from the summit of Pinnacle .Mountain. The exposures on the west shore of Herendeen 

Bay * * * consist chiefly of fine-grained blue sandstones. [The fossils have been examined by Stanton], who reports that within the Upper Jurassic of Herendeen Bay two horizons are 

represented. At the upper horizon are forms related to Aucella pallasi. * * * At the 

lower horizon are forms related to Aucella bronni. * * * 

Among the collections procured from the Chignik Bay region there are no fossils of Lower 

Cretaceous age. In parts of this region, at least, the Upper Cretaceous beds unconformably 

overlie the Upper Jurassic, and it may be that there is no Lower Cretaceous in the region. In the 

Herendeen Bay district the Lower Cretaceous appears in three belts extending through the 

Herendeen Bay coal field, coming to the surface on the flanks of the folds. The fossils * * * 

from these formations indicate that there are two horizons within the Lower Cretaceous. At 

the upper horizon are forms related to Aucella crassicollis, and at the lower are forms related 

to Aucella piochi. * * * The sediments * * * consist of sandstones, shales, and 

conglomerates. 

0 8. SOUTHEASTERN ALASKA. 

The Cretaceous rocks of southeastern Alaska comprise Aucella-bearing beds, 

which are Lower Cretaceous or possibly Jurassic, and a higher terrane, apparently 

unconformable to the Aucella-bearing beds, but conformable to the overlying Kenai 

formation (Eocene) and containing plant remains. Brooks 1011 thus sums up the 

known facts: 

The recent studies of Wright have revealed the presence of the Aucella-bearing beds along 

the eastern coast of Admiralty Island in a series of conglomerates, graywackes, and slates. 

Stanton makes the following statement in regard to the fossils from these beds: 

"The specimens of Aucella from Pybus Bay, Admiralty Island, are apparently referable to 

species that in California and adjacent States are characteristic of the Lower Cretaceous, 

Aucella piochii occurring in a lower zone than Aucella crassicollis. The Alaskan specimens probably also come from the Lower Cretaceous, although strict correlation is rendered somewhat 

hazardous by the fact that the genus Aucella with similar specific forms ranges down into the 

upper Jurassic." 
LOWER CRETACEOUS. 633 

Wright has also found a conglomerate sandstone and shale series on Kupreanof Island, 

a few miles south of Admiralty Island, which carries plant remains assigned to the Upper 

Cretaceous. Knowlton reports on these fossils: 

"These plants indicate beyond question that the age is Cretaceous, and I would place them 

in the lower part of the Upper Cretaceous, or approximately of Cenomanian age." 

It appears that these Upper Cretaceous beds are discordant to Aucella-bearing terranes 

of the adjacent region, and that they are confcrmably succeeded by the Kenai (Eocene) rocks, 

with which they are lithologically identical. 

Later information by Wright 953 is as follows: 

[Part ~fJ stratigraphic column in southeastern Alaska. 

Age. Character of rocks. Thickness Structural characteristics. (feet). 

-----

Basalts, andesites, rhyolite tuffs, brec- 1,500± Flat-lying, slightly tilted, covering 

cias, conglomerates, sandstones, and wide areas. " 

Eocene to Upper coal seams, with fossil plants. 

Cretaceous. Conformity. 

Conglomerates, sandstone, shale, and 1,000+ Tilted, slightly folded, unmetamorcoal seams, with fossil plants. phosed, occupying local basins. 

Unconformity. 

Shale, conglomerate, and black lime- 500+ Folded and faulted, with steep dips and 

stone with fossils. variable strikes, slightly metamorphosed, occurrence local. 

Conformity. 

Gray limestone, Aucella beds ..... _ ..... 200+ Same as above. 

Lower Cretaceous to 

(?). 

Graywackes, slates, and conglomerates, 2,000± Folded and faulted, indurated, variable 

Jurassic. carrying granite cobbles; lava con- strike and dip, distribution limited. 

glomerates, and sandstones; no fossils. 

Conformity. 

Andesite lavas, tuffs, breccia, conglom- 1,000± Steeply tilted and folded with general 

erate, and sandstone overlying granite northwesterly strike and variable dip, 

intrusives; no fossils. metamorphosed and rendered slightly 

schistose; distribution limited. 

0-P 4. LOWER YUKON AND KUSKOKWIM BASINS, ALASKA. 

The so-called Cretaceous of the Kuskokwim basin, represented as Lower Cretaceous on the map, comprises both sedimentary and volcanic rocks which constitute 

three different series, according to Spurr, and which may be older than Cretaceous, 

according to Brooks. 101i 

Spurr subdivided the Mesozoic rocks of the Kuskokwim Valley into three series, all Cretaceous, of which the Holiknuk and Kolmakof series are supposed to be synchronous, while the 

stratigraphic relation of the third-the Oklune series, which is Jura-Cretaceous-to the others 

is unknown. The Holiknuk series is made up of alternating sandstones, argillaceous and 

siliceous limestone containing fragmentary Cretaceous fossils, and shale and arkose, all thrown 

up in broad open folds. An unconformity determined the line of demarcation between these 

beds and the underlying Tachatna series (Devonian). 

A succession of volcanic rocks of various types occurs to the southwest, and these, together 

with some intercalated tuffs, shales, impure limestones, and arkoscs, form Spurr's Kolmakof 

series, supposed to be synchronous with the Holiknuk beds. A group of sediments, including 

shales, impure limestones, with some arkoses, received the name "Oklune series," from the 

mountains where they arc typically exposed. These beds are referred to the Jura-Cretaceous 

on the evidence of some fragmentary fossils. As far as the facts presented can be interpreted, 

all three of these series may belong to the same horizon. All three exhibit about the same 

amount of deformation and are intruded by igneous rocks of various kinds. If they are not of 
634 INDEX TO THE STRATIGRAPHY OF NORTH AMEIUCA. 

·the same age, it is probable that the Holiknuk belongs to the Jurassic or the Triassic and that 

the others are younger. 

Maddren 569 gives the following description of the Cretaceous in a generalized 

table of stratigraphic sequence in the central Kuskokwim, Innoko, and lowercentral Yukon region: 

Conglomerates, arkoses, and shales, with some coal beds on the Yukon. Contains acidic 

dikes and sills on lower Kuskokwim and also basic volcanic material. Fragmentary plant 

remains and marine shells. Probably includes both Upper and Lower Cretaceous. Occurs 

throughout the lower Kuskokwim Mountains, southeast side of the Innoko Valley, northw:est 

side of lower Yukon Valley, lower Koyukuk Valley, and upper part of central Kuskokwim 

Valley. 0-P 8. SOUTHERN YUKON TERRITORY AND BRITISH COLUMBIA. 

In the vicinity of Lake Bennett (near latitude 60°, longitude 135°) the porphyrite and tuffaceous rocks of the middle and bter Mesozoic are developed with 

the typical characters of the "Porphyrite group." The description by Cairnes 114 

is in part as follows: 

Newer than these Coast granites is a series [Windy Arm] chiefly consisting of porphyrites, 

diabases, andesites, tufTs, and basalts which cut through and overlie them, by far the greater 

part of the rocks being porphyrites which are generally fine-grained and greenish in color and 

present a fresh, unaltered appearance. 

Following an account of the petrographic character and eruptive relations of 

the porphyrites, Cairnes continues: 

There have been great showers of ashes and finer material which have consolidated into 

generally fine-grained greenish rocks showing bedding structure which is often quite pronounced, 

giving the rocks the appearance of fine-grained sandstones and shales. In places these particles 

have fallen into water and show to some extent water-sorting action and are mixed with argillaceous and other sedimentary materials. These rocks seem to grade into true sediments as 

shales, conglomerates, bedded cherts, cherty quartzites, etc., which carry coal seams. * * * 

The true sediments with some of the upper bedded ash rocks and tuffs are included in the 

Tutshi series described below. The rest are included in the Windy Arm series. The whole 

series appears to correspond to Dr. Dawson's Porphyrite series. * * * This Windy Arm 

series also corresponds, in all probability, to the rocks of division IV on Mr. Gwillim's Atlin 

map * * * and includes the corresponding representatives of the greenstones of his gold 

series division VI, which ·are newer than the granites. The corresponding representatives of 

the other members of division VI, which are older than the granites, have been included in 

this report, and on the map in the Lower Cache Creek series. * * * 

Tutshi series.-This name was given by Mr. McConnell to include the" argillites, tufaceous 

sandstones, conglomerates, etc.," of the Windy Arm district, and the writer has adopted the 

name for all rocks in the area that appear to belong to this same series. These Tutshi rocks, 

which in all probability * * * correspond to the rocks of Mr. Gwillim's division III on 

his Atlin map, belong, as well as the Windy Arm series, to Dr. Dawson's Porphyrite series 

and correspond lithologically and stratigraphically with his Jackass Mountain series. * * * 

This latter consists chiefly of igneous products, and the Jackass Mountain series resembles 

rocks of ordinary aqueous origin. * * * All rocks, therefore, which are of aqueous origin, 

and all those associated and interbedded with them, are placed in this Tutshi series, as water 

action has had more or less effect on all of them and has not affected the rocks of the Windy 

Arm series. Dr. Dawson considered the Porphyrite series to be probably a link between the 

Jurassic and Cretaceous, making the Jackass Mountain beds Lower Cretaceous. The fossils 

found this season in these Tutshi beds, being all typically Lower Cretaceous, further bear out 

this correlation. 
LOWER CRETACEOUS. 635 

The fossils identified by Whiteaves from the Tutshi series of McConnell comprise: 

Trigonia, small, arcuate, and beaked species. Two other Pelecypoda, imperfect and 

undetermined. Shales with numerous valves of an Estheria or of very young specimens of 

Inoceramus. Also two crushed fragments of a small ammonite, apparently referable to Prionocyclus woolgari. These are all placed under the head "Cretaceous" and are probably 

lower Cretaceous as described above. 

Stanton's comment a on the above identifications is that the only specific 

name mentioned is characteristic of the Upper Cretaceous. 

Q 4-5. KOYUKUK BASIN, ALASKA. 

The Koyukuk "series" is a Lower Cretaceous or possibly Jurassic terrane, 

consisting of impure limestone, slate, and some sandstone, associated with igneous 

rocks. It carries Aucella crassicollis Keyserling. It occupies a large area in the 

lower Koyukuk basin, where it was first distinguished by Schrader.1011 

Q 7. UPPER YUKON, ALASKA. 

The latest report on the upper Yukon, that of Brooks and Kindle, 103 gives the 

following section of the later Mesozoic rocks (post-Triassic): 

Provisional stratigraphic table. 

System. Series. Lithologic character. Locality. 

Upper Cretaceous. Conglomerates, sandstone, slate, and 

shale, cut by granite. Invertebrate 

fossils. 

Wolverine :Mountains, Quail 

Creek, near Rampart. 

Cretaceous. Unconformity. 

Lower Cretaceous or Up- Siliceous slate and quartzites, with some Upper Yukon River, between 

per Jurassic . tuff and a little limestone, cut by basic Fourth of July and Coal 

dikes. Invertebrate fossils. creeks. 

Unconformity. 

The only member of the Mesozoic extensively developed along the Yukon is the so-called 

Aucella beds, which may be either Jurassic or Lower Cretaceous, but may here for convenience 

be assigned to the latter system. These Lower Cretaceous beds form a practically continuous 

belt along the Yukon from about the mouth of Fourth of July Creek to Coal Creek. There may 

be, however, some of the younger Tertiary beds included within this area which were overlooked 

in the hasty examination. 

The Lower Cretaceous of the upper Yukon comprises a series of closely folded rocks characterized by a large amount of silica. They included primarily siliceous slates, slaty sandstones, 

and quartzites, with which are associated some argillites and pyroclastics. One heavy bed 

(50 to 70 feet thick) of massive tufaceous conglomerate was observed within the Mesozoic area 

about 5 miles below Washington Creek, but may be an infolded older or younger terrane. The 

pebbles of this conglomerate, which are chiefly limestone, are well rounded, and some 

are 2 feet in diameter. The dominating rock type of the Lower Cretaceous is a siliceous slate 

or quartzite, sometimes interbedded with a clay slate. These rocks are usually pyritiferous 

and iron stained when weathered. Three miles below Washington Creek there is a series of 

beautifully banded slates and quartzites. * * * 

These rocks in a general way strike easterly and northeasterly, but there are many local 

variations. They are usually closely folded, and no determination of thickness, which probably 

does not exceed a few thousand feet, could be.made. On Washington Creek they appear to 

rest unconformably on the Devonian and in turn are unconformably overlain by the Tertiary 

a Personal communication. 
636 INDEX TO THE STRA'l'IGRAPHY OF NORTH AMERICA. 

beds. Near Coal Creek the Aucella-bearing beds seem to underlie the Upper Carboniferous 

limestone, which has apparently been thrust over them. 

R 3. CAPE LISBURNE, NORTHWESTERN ALASKA. 

Collier 1650 found a thick sequence of strata apparently overlying the Corwin 

formation (Jurassic), and in the absence of fossils assigned it provisionalLy to the 

Lower Cretaceous. He describes it as follows: 

Southwest of the area occupied by the Corwin formation, and lying between it and the 

Carboniferous rocks exposed at Cape Lisburne, there is a series of beds which, though they 

resemble the Corwin Jurassic rocks, are easily differentiated from them on lithologic grounds. 

These rocks outcrop along the coast from a point 2 miles west of Corwin Bluff to within 3 miles 

of Cape Lisburne and extend inland in a southeasterly direction. * * * The exact contact 

of this formation with the Corwin was not exposed, or if observed its significance was not 

understood, though the field relations of the two formations are definitely known at a number 

of localities. Continuous sedimentation and conformity between the formations are indicated, 

though the possibility of thrust faulting along the contact should not be overlooked. This 

formation is therefore provisionally regarded as overlying the Corwin and constituting an upper 

member of the Mesozoic series. * * * 

Lithologically this formation consists of sandstones and shales, with the former in the 

ascendant. The sandstone beds range in thickness from a few inches to 20 or more feet. They 

resemble the sandstones of the Corwin formation, but taken as a whole are probably somewhat 

less gritty and contain no conglomeratic material. The shales which are interbedded with the 

sandstones are dark colored and sometimes micaceous, so that they have a silvery sheen on the 

bedding faces. In a few instances ripple marking was observed on shaly beds. 

No definite fossils were found, after a diligent search, either in the sandstones or the shales, 

though indistinct impressions of vegetable fragments, probably detrital material, were found 

in some of the beds. The structure of the formation, while it consists of simple open folds near 

its boundary with the Corwin, becomes increasingly complicated as the fault at the contact 

with the Carboniferous rocks is approached. Overturned folds and minor thrust faults with 

axes extending in a general way northwest and southeast are typical features. * * * 

Owing to the complex structure of this formation, it was impossible to definitely m&asure 

its thickness, but from the imperfect evidence obtained it is believed to be not less than 5,000 

nor more than 15,000 feet, and for the purposes of this report it is estimated at 10,000 feet. 

Since no direct paleontologic or paleobotanic evidence was obtained, the age of the formation 

can only be inferred from its relation to the Jurassic Corwin formation, which it overlies. It 

is therefore provisionally assigned to the Lower Cretaceous. On Anaktuvuk River, 400 miles . 

east of Cape Lisburne, Schrader found a formation somewhat similar to this, both in its lithology and in its topographic relations to the Lisburne formation, which he called the Anaktuvuk 

series a and which contains Lower Cretaceous fossils. If the above assignment is correct, the 

upper Mesozoic formation of the Cape Lisburne region should be correlated with the Anaktuvuk 

senes. 

R 5. NORTHERN ALASKA, ARCTIC SLOPE. 

According to Schrader 1011 the Cretaceous which he crossed in descending the 

Colville may be divided into two groups, which are unconformable-" the Anaktuvuk (Lower Cretaceous) and the Nanushuk series (Upper Cretaceous)." 

The Anaktuvuk is made up of fine, heavy-bedded sandstones, or arkose-sometimes a 

grit, with little conglomerate-the whole aggregating at least 2,000 feet. Resting unconformably on these are sandstone, impure limestone, slate, quartzite, and chert, which make up the 

Nanushuk series. The Anaktuvuk carries Aucella crassicolis Keyserling, making it JuraCretaceous, while the Nanushuk has yielded Upper Cretaceous fossils. The Nanushuk, like 

the Upper Cretaceous of the lower Yukon, contains coal seams of excellent quality. 

a Schrader, F. C., Reconnaissance in northern Alaska: Prof. Paper U. S. Geol. Survey No. 20, 1904, pp. 74-76. 
Color, light green. 

Syrnbol, 7. 

CHAPTER XV. 

UPPER CRETACEOUS. 

Distribution: South America and West Indies; present but not distinguished in Mexico from 

Lower Cretaceous; Atlantic and Gulf coasts from Mexican boundary to New England; 

the Interior province, New Mexico to :Mackenzie; Pacific coast, Lower California to Alaska; 

the Arctic coastal plain of Alaska; and the west coast of Greenland. 

Content: Marine and coastal-plain deposits of the Atlantic and Gulf coasts and West Indies, 

comprising Raritan to Manasquan, New Jersey; Black Creek ("Bladen") and Peedee 

("Burches Ferry"), North Carolina; Tuscaloosa to Ripley, Alabama; and the Gulf seriesthat is, Woodbine to Navarro-of Texas and Louisiana. In Mexico included on map 

with Lower Cretaceous (8). Marine and coastal-plain deposits of the Interior, Dakota to 

Fox Hills, inclusive, and equivalents. Marine deposits of the Pacific coast, Chico and its 

equivalents. Laramie and coal-bearing portion of the Montana of the Rocky Mountains 

and Great Plains mapped separately. 

Color, olive-green. 

Syrnbol, 7 a. 

MONTANA, COAL-BEARING PORTION. 

Distribution: Rocky Mountains and northern Great Plains of the United States and Canada. 

Content: Middle Montana, generally coal bearing; Mesaverde of New Mexico, Colorado, and 

southern Wyoming; Eagle, Claggett, and Judith River of northern Wyoming and Montana and their equivalents in Canada. 

Color, yellowish green. 

Syrnbol, 6. 

LATE UPPER CRETACEOUS. LARAMIE. 

Distribution: Rocky Mountains of the United States, southern Wyoming to New Mexico. 

Content: Late Cretaceous coal-bearing formations; Laramie of the Denver Basin; "Lower 

Laramie" of southern Wyoming; and coal-bearing <'quivalents in Colorado and New Mexico. 

Upper Cretaceous areas. 

D 19 ........................ Curacao, Aruba, and Bonaire .............................. __ .: ...... , .... . 

E 18 ......................... Jamaica .............................. _ ............................ _ .... . 

E 19 ...................... _ .. Santo Domingo .......................................................... . 

F17-18 ....................... Cuba ................................................................... . 

F-G 13-14 ......... _ .......... Mexico (mapped in part) ............................................ ___ .. . 

G 12, II 11 ........ _ . _ ....... _Lower California .................................. _ ........... _ . _ ........ . 

G-Il 13-14 .......... _ ........ Coahuila and Zacatecas, Mexico ..................... _ .... _ ...... ___ ....... . 

H 14 .............. _ ... _ ...... Southern Texas .......................................... __ .............. . 

II-I 14 .......... _ ............ Northeastern Texas ................................................... _ .. . 

I 15 ............. _ ......... _ .. Northeastern Texas, Arkansas, and Louisiana ...•........................... 

I 16 .............. _ ......... _. \Yestern Tennessee ..........................•.................. _ ......... . 

I 16-17, J 16 .... : ............. Eastern Gulf region, Georgia, and South Carolina ........................... . 

I -J 13 ..................... _ .. Colorado and New Mexico ................................................ . 

I-K 10 ....................... California and southern Oregon ......................................... _ .. . 

I-K 10 ....................... Atlantic Coastal Plain. (See Chapter XIV, pp. 608-614.) 

J 12 .......................... Plateau province of r tah and Colorado. . ................................. . 

637 

Page. 

639 

639 

642 

643 

644 

644 

648 

649 

650 

652 

653 

654 

660 

667 

670 
FIGURE 17.-Sketch map showing the distribution of Upper Cretaceous rocks represented on the geologic map of 

North America and the key to references in the text. Includes Laramie and coal-bearing Montana, which are 

mapped separately where their extent is known. 

638 
UPPER CRETACEOUS. 639 

Page. 

J-K 13-14. __________ . __ . ____ .Eastern Colorado, Kansas, and Nebraska.................................... 672 

K 12. _ .. _____________________ Northeastern Utah, northwestern Colorado, and southwestern Wyoming·_...... 673 

K 13 _ .. _. __ . __ .... ___ . _. _____ Northern Colorado and Wyoming........................................... 678 

K 14-15 _____________ . _ . ______ Iowa and Minnesota. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 682 

K 18. _ . _ . ___ ...... _ ..... _____ Long Island . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 682 

K 19 ... __ .. _ . ________________ Massachusetts (not mapped) ....... __ . __ . _ ...... _ ........... _ ... _ . ____ . . . . . 682 

K-L 12-13 ...... _____ . _ ....... Northern Wyoming ...................... -- ... ---- ......... --- ......... --.. 684 

K-L 13. ___________ . _. _____ ._.South Dakota and northwestern Nebraska ..................... -............. 685 

L 10 ... __ . _ ....... _. _ ... ___ ._.Western Washington······-····················--- ...... -.... ____ ......... 685 

L 10-11... _ .... ______________ .John Day Basin, Oregon. (See Chapter XIV, p. 621.) 

L 12-13. ____________________ .. Eastern Idaho, northwestern Wyoming, and Montana.. . . . . . . . . . . . . . . . . . . . . . . 685 

L 13-14 .. __ ... _ .. _. __ . _____ ... South and North Dakota ........................................... -.-...... 691 

M 9-10 .. __ ................... Vancouver Island ........................................... -............. 692 

M 11. _ . ____ .... _. ___ .. _. __ . __ Canadian Rockies, Alberta and British Columbia (not mapped)............... 693 

M 12 ... _ . _ ................... North western Montana. . . • • . . . . . . . . • • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 694 

M-N 11-14 .................... Plains of Alberta, Saskatchewan, and Manitoba .......................... -.. 695 

0 4-5 ... ____ ................. Alaska Peninsula (mapped with Jurassic)................................... 698 

0 8. _ ... __ . _ .......... _ . _ . _ .. Southeastern Alaska. (Mapped with Lower Cretaceous. See Chapter XIV, 

pp. 632-633.) 

0 10-12. ____ ................ _Northern British Columbia and Alberta........... . . . . . . . . . . . .. . . . . . . . . . . . . . 698 

P 8 ... _. ___ ........ _ .. _._._._.Lewes River, Yukon Province ....... _____ ... __ ............................ 700 

P-Q 4 _____ ........ ·- ... _ .. ___ . Lower Yukon, Alaska.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 701 

Q 7 _. _ .. ____ .. ______ . ____ .... Upper Yukon. Alaska (notmapped) ..•.. __ ....... ____ ... __ ... -- ...... ------ 703 

Q 8 .. ___ . ___ .......... _ . _ .. __ Northern Yukon Territory.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 703 

Q-R 8-10. _ .................. _Mackenzie basin. . . . . . . . . . . • • . . . . . . . • . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 703 

R 5. ____ . _. ________ . _ ....... Northern Alaska, Arctic slope. (See Chapter XIV, p. 636.) 

R 22. ______ ............. _ .. _West coast of Greenland ................. _................................. 704 

D 19. CURACAO, ARUBA, AND BONAIRE. 

The little islands of Curacao, Aruba, and Bonaire, in the Dutch West Indies, were 

mapped by Martin.576 He identified the Upper Cretaceous (Rudist(mkalk), which 

on Curacao consists of a fine-grained crystalline limestone, of dirty blue or yellowwhite color, that resembles a Paleozoic rock. The strata are rich, however, in 

remains of Rudistes radialites Lam., which are identified by Stanton on the basis 

of Martin's illustrations as of Upper Cretaceous age. There is also a siliceous slate 

formation with which the limestone occurs in immediate and conformable contact. 

E 18. JAMAICA. 

Hill's work on the geology of Jamaica 443a is the basis of the mapping of that 

island and affords the following excerpts. Many details of the original work are 

necessarily omitted. Hill classifies the geologic formations of Jamaica into four 

great categories, as follows: 

1. A fundamental series of stratified shales and conglomerates (of terrigenous origin), 

tuffs and other debris of volcanic material (whose source is not apparent), and, rarely, marine 

limestones and marls, all of which have suffered great displacement and deformation. This 

series characterizes the higher mountains and forms the nucleus of the island structure upon 

or around which all subsequent formations have accumulated. 

2. A series of organically derived oceanic material-marls and limestones-which rest 

unconformably against and upon but do not completely overlap the more elevated outcrops 

of the first-mentioned series. It constitutes piedmontal formations of great thickness around 

bases of the higher mountain summits. 

3. Laccoliths, dikes, and sills of igneous rocks, which penetrate the first series and the 

lower portion of the second and nre, therefore, of later age than both. 

4. Ct'\rtain deposits of alluvium, oceanic marls, and coral reef rock, which are adjacent to 

the present coasts and represent fringing reefs and other accretions around the island's border 

after it had almost attained its present area and outline. 
640 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

These four series of rocks are unconformable to one another and are the products of the 

greater events in the geologic history of the island. 

Hill gives a tabular summary of the geologic history of the island, of which the 

following is a part: 

Geologicformations on Jamaica. 

Time. Series. Formation. l\fa terial. Fossil remains. 

--- ------- --------

Bogue Island. _____ Mangrove mud. 

Montego _ .. _ ... ____ Alluvial. 

Late Pleistocene and Coastal. Falmouth. ___ ... __ Littoral marL ____ ._ .... _. Marine Mollusca, reef coral, 

Recent. etc. 

Coast Soboruco _ .. __ Elevated reef rock._._ ... _ Reef coral. 

Barbican. ______ . _ .. Elevated reef rock. ___ .... Reef coral. 

HopewelL _________ . 1£levated reef rock. ___ ... _ Reef coral. 

··--- ---· --

Pliocene. ManchioneaL . _ . _ . _ Littoral marl. Marine Mollusca, Forami- Kingston ___________ Old aggradational material_ nifera, Brachiopoda. 

- ---- -----

May Pen. _________ Impure lime. __ . __ . ____ ._ Marine Mollusca, echinoids, 

Miocene or late Bowden. simple corals, ForamiOligocene. nifera, and Bryozoa. Bowden ___________ Conglomerate and marL __ Same as above, and freshwater shells. 

----

Middle Oligocene. Break. 

Co br<J _____________ V.'hite limestone and marl. 

Moneague. _________ vYhite limestone. ____ .. ___ A few mollusks and simple 

corals. 

Montpelier ________ White chalk with flints_. __ Foraminifera and RadioEarly Eocene to early Oceanic. !aria. 

Oligocene. Chapelton. ___ . _____ Yellow-white limestone ___ Mollusca, corals, echinoids, 

and Foraminifera. 

Catadupa. _________ Nodular limestone in clay. 

Richmond ... _ ... _. Alternation of clay and 

sandstone .... ______ . _ . _ A few mollusks and coralR. 

-------· --- -----------

Minho ______ . _ . _ . ___ Volcanic tuffs. Ballard. ________ .. __ Black bituminous shale ___ Rudistes, corals, and mollusks. 

Logie Green .. __ . __ Yellow marls. __ ... _. __ . __ Rudistes, corals, and molLate Cretaceous. Blue Mountain. lusks. 

Jerusalem ________ . _ Irregular beds of limestone. 

Frankenfield .... _ .. Irregularly bedded lavas, Rudistes, corals, and moltuffs, and conglomerates 

of hornblende andesites. 

lusks. 

In his table Hill placed the line between the late Cretaceous and early Eocene 

above the Richmond. In copying the table it has been moved to a position below 

the Richmond, on recommendation ofT. W. Vaughan and in accordance with the 

text of Hill's work, which shows. clearly that he regarded the Richmond as early 

Eocene. 

The late Cretaceous rocks of Jamaica are called Blue Mountain series, of which 

Hill says: 

This series comprises the oldest rocks of the island. It consists of loose or slightly indurated 

beds of gravel, clay, bowlders, and tuffs, with exceptional beds or bosses of hard indurated 
UPPER CRETACEOUS. 641 

limestones and yellow clay. The rocks are usually of dark color (black, blue, or dull chocolate), 

in strong contrast to the glaringly light colors which characterize the succeeding formations 

of the Oceanic and Coastal series. The material, with the exception of occasional limestone 

beds and a few outcrops of clay marls, can be traced to igneous rocks; it was first volcanic 

ejecta and subsequently and successively underwent various degrees of attrition and sedimentation from coarse bowlders and tuffs to finely triturated impure clay shale, a process 

indicating extensive working over. These rocks are the material of the Central Mountains, 

composing the eminences above 3,000 feet, such as the Blue Mountain Ridge. They undoubtedly underlie the surface rocks of the rest of the island, as occasionally revealed by erosion 

through the white limestone which veneers them, as seen in some of the central basin valleys, 

the canyons of the marginal streams, and certain bluffs of the back coast border along the 

northwest coast. 

Nowhere on the island can all the beds of the series be seen in continuous exposure. As 

has been noted concerning the rocks of the Blue Mountain district, "the strata are so excessively 

disturbed, so traversed and semimetamorphosed by dikes of syenite and mixed up with porphyritic masses, that it is impossible to observe the intricacies of the stratification or to determine 

the sequence of the beds inter se without a lengthened and detailed investigation." Sufficient 

is known to state that it probably exceeds 5,000 feet. 

Previous attempts to classify the rocks which are collectively arranged in this series have 

been confusing and unsatisfactory. * * * 

While it is still impossible completely to differentiate all the beds of the Blue Mountain 

series, our observations have enabled us to make a more accurate classification of them than 

any hitherto presented, which may be stated as follows: 

Blue Mountain series: 

Upper division (Eocene): Richmond beds. 

Lower division (Upper Cretaceous): 

Minho beds. 

Ballard beds. 

Logie Green beds. 

Frankenfield beds. 

Jerusalem beds. 

Yallahs beds. 

[In classifying the basement beds the chief difficulty] is the complex folding and partial 

concealment which make it impossible to determine the exact base of the series. The Jamaican 

reports present conflicting conclusions on this subject, inconsistently stating in different places 

that the base of the section is composed of igneous rocks, Cretaceous limestones, and a formation 

termed the "Metamorphosed series." 

Hill quotes various opinions and states that the visible base of the section is 

a great series of tuffs and conglomerates in which the fossiliferous Cretaceous beds 

constitute local occurrences. The limestones are certainly the oldest rocks paleontologically identifiable, but they are clearly intercalations in vast beds of igneous 

debris. He searched with care but in vain for evidence of some older or lowerlying rocks beneath the Blue Mountain series. 

Referring to the lower division or Upper Cretaceous of the Blue Mountain 

series, Hill says: 

All beds of the lower subdivision, taken collectively, represent the product of disturbed 

conditions, such as active volcanism accompanied by the piling up and contemporaneous 

degradation of vast quantities of igneous material much of which was deposited below the sea 

level, alternating with short periods of quiescence, ·when shdes and marls were permitted to 

accumulate and sparse faunas to gain temporary foothold. The alterations of shale and igneous 

material in the Blue Mountain series indicate alternating conditions of sedimental placidity 

48011°--12----41 
642 INDEX TO THE STRATIGRAPHY OF NOHTH AMERICA. 

and volcanic extrusion, and a conflict between disturbed and quiescent conditions of deposition 

which finally culminated in the establishment of the latter in the succeeding Richmond epoch. 

For a description of the Richmond and later beds of the early Tertiary, see 

Chapter XVI (pp. 717-721). 

E 19. SANTO DOMINGO. 

The Sierra group of S::tnto Domingo was described by Gabb as of Cretaceous 

age. His account of the rocks shows them to be highly metamorphosed and varied 

in character, and generally unfossiliferous. For this reason the major part of 

the terrane is mapped as Paleozoic undivided, and his description is quoted in 

Chapter VII (pp. 345-347). The description of the limestone which contains 

Cretaceous fossils is as follows: 352a 

On the Nigua River the limestone acquires its greatest development. Here the metamorphic action has been unusually well marked and the formation.is represented mainly by limestones and jaspers. The stratification also is unusually well preserved, so that a good section 

is attainable. The lime strata of the Ocoa are apparently all repeated on the Nigua, and -the 

conglomerates are replaced by beds containing but few pebbles, the matrix being either a pure 

or more usually an earthy limestone. This latter rock, at two loca1ities on the river, yields 

fossils, in a bad state of preservation for extraction, although occasionally recognizable. The 

shell substance is completely crystallized, so that it is next to impossible to extract a thick 

shell in such a manner as to expose its surface. Of hundreds of attempts to obtain a specimen of a very common Trigonia I have only succeeded once or twice in obtaining a little piece 

of the surface; the fracture always taking place among the crystals of calc spar into which 

the shell has been cemented. The univalve shells invariably break across and, in a word, 

the collector has to content himself with the few imperfect fragments found weathered out. 

Nowhere else have fossil Mollusca been discovered in this formation in Santo Domingo, and 

only in one other instance have I found any ,other fossil in it. Three or four miles west· of 

San Jose de las Matas I was fortunate enough to discover two fragments of the same limestone, 

being of a dark bluish-gray color, on the surface of which can be detected, faintly marked, 

the stars of a coral. Doubtless by means of polishing they can be brought out. These are 

of especial value, being the only traces of corals yielded to us by the formation; unless indeed 

a stray pebble, found on the surface of the ground near Bani, also containing corals, may 

belong to the same group. On the peninsula of Samana the limestones are highly metamorphosed, and here occurs a very curious mixture. In some cases the limestone has a few 

scattered scales of mica embedded in it; in others the mica is so abundant as to form layers, 

while not infrequently, especially in the eastern part, mica slate, alternating with the limestone, is not an unusual feature. This is the more remarkable since it occurs nowhere else 

on the island, and in only one other locality is mica found, and there in hardly noticeable 

quantities. 

With so few data it would seem hazardous to venture a determination of the geological 

age of the group of rocks in question. But a careful study of the scanty material at my disposal reveals the existence of a serrated oyster, a Trigonia, a Turritella, shells resembling 

Ancillaria, Natica, Pugnellus (?), and Mactra, besides a fusoid, one fragment that seems to 

belong to the group of Pterocrea-at least it is an alate shell-bivalves that may prove to 

be Cucullooa and Lima, and better than all else a beautiful little ammonite in perfect preservation, 

and a fragment that I think more careful study will decide to be a piece of a baculite. From 

the above list it will be seen that there can be no possible doubt of the secondary age of the 

rocks. The ammonite restricts it so far. The style of the ammonite besides confines it to 

the two groups of Jurassic and Cretaceous, a determination corroborated by the Trigonia, 

which further belongs to a type much more common in the latter than in the former formation, 

resembling T. emoryi Con., T. evansana Meek, and T. mooraena Nob. (T. crenulata Roem., 
UPPER CRETA CEO US. 643 

not Lam.). In fact I am not sure but that the second of these species is also found in New 

Grenada, whence it was previously described by Mr. Lea as T. tocaimaana, and that the present 

one may have to be included under the same name. The gastropodous shells are of but little 

real assistance, although the Ancillaria belongs to a type as yet only known by one of two 

species high up in the Cretaceous; the oldest members of the family being in that horizon. 

The naticoid of course has but little weight, while my generic determination of the ( ~) Pugnellus 

is not sufficiently sure to warrant me in availing myself of this really valuable aid. 

The Mactra is not of any great stratigraphical value, and the other bivalves are of still 

less importance. The baculite, if it should prove to be such, is a little fragment so embedded 

in the matrix that it will have to be developed by grinding or polishing, since any other process 

would inevitably destroy it. It will be thus seen that the formation is either Cretaceous or 

Jurassic, and the preponderance of evidence is in favor of the Cretaceous. This receives additional weight from the results of the labors of other geologists in the Caribbean region. * * * 

Dr. P. Martin Duncan has elaborately studied and described the fossil corals of the West 

Indies, having had large collections from nearly all of the islands at his disposal. He is quoted 

by Mr. Etheridge as anticipating the discovery of Cretaceous rocks in Santo Domingo on 

account of some corals from the Miocene of the Cibao, which seemed out of place in that 

formation. a 

F 17-18. CUBA. 

T. W. Vaughan has contributed the following original notes to this work: 

Cretaceous formations possess an extensive development in Cuba. In the Province of 

Havana calcareous strata containing Upper Cretaceous fossils occur at Santiago de los Banos. 

Lying between the Tertiary limestones and the serpentine protaxis in the vicinity of Havana 

are glauconitic limestones, somewhat earthy in composition, and magnesian marls, which 

have been referred by Salterain to the Cretaceous. We consider the age of these beds as doubtful, as neither the paleontologic nor the stratigraphic evidence is sufficient to warrant a positive 

conclusion. 

Occurring below the lowest observed fossiliferous Tertiary strata in the vicinity of Matanzas 

are limestones, sandstones, and shales which occupy the same relative stratigraphic position 

as the supposed Cretaceous of the region near Havana and may be referable to this geologic 

period. Cretaceous formations occupy extensive areas in the central portion of the Province 

of Santa Clara, where such typically Cretaceous fossils as Barrettia, Requienia, etc., were 

collected. The basement beds consist of an unfossiliferous arkose, composed very largely 

of material derived from the underlying serpentine and granite. Above these basement beds 

lies a hard grayish limestone replete with the remains of organisms characteristic of the Cretaceous period. Formations of the same age occur also in the vicinity of Cienfuegos, and 

Cretaceous strata of calcareous composition occupy extensive areas in the central portion of 

the Province of Camaguey. Strata have been referred to this age in the literature on Oriente 

Province, but as no fossils have been listed there is doubt as to the extent of the area underlain by the Cretaceous in this portion of the island. Coal-bearing sandstones of no economic 

importance occur at various places in eastern Cuba and are perhaps of Cretaceous age. 

In the Province of Pinar del Rio, between Vi:fiales and the city of Pinar del Rio, there 

is a hard grayish limestone overlying the schists. No paleontologic evidence as to the age 

of this limestone was obtained, but from its stratigraphic position and general lithologic character 

it is referred provisionally to the Cretaceous period. 

a Etheridge (Geological report of Jamaica, Appendix V, 1869, p. 308) says: "Dr. Duncan has also stated his belief 

that 'the Hippurite limestone exists in the neighboring island of Santo Domingo, basing this opinion upon the fact 

that corals having very decided lower Cretaceous affinities were noticed in Miocene strata' in that island. He noticed 

having found the. European lower chalk coral Astrocomia decaphyllia in the Jamaican Miocene; Phyllocomia seulpta, 

from the Gosau and Uchaux beds, was also found in the Nijavi shale in St. Domingo, associated with four other species 

of Turonien affinities in the same shale." 
644 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

F-G 13-14. MEXICO. 

The Upper or Neo-Cretaceous of Mexico is described in general terms by Aguilera/c as follows: 

The Nco-Cretaceous is encountered principally in the northern part of the Republic and 

commences with shales of the lower Turonian characterized by Inoceramus labiatus of the 

Ligerian substage. This substage occurs at Cerro Prieto, at the foot of Cerro Muleros, near 

the city of Juarez. It is also known in the north of Zacatecas, at Mazapil; in Coahuila, at 

Parras and Peyotes, and in the latter locality it contains, besides Inoceramus labiatus Schlotheim, Ptycliclus mortoni Mantell, Ptychodus cf. whiplei Marcou, Ceratodus sp., Tryonix sp., 

and many -ceeth of fishes, etc. 

The upper Turonian or the Angoumian and the Emscherian or lower Senonian have not 

as yet been found in Mexico characterized by their fossils. The rocks of this age in general 

are shales interbedded with occasional layers of limestone and are unfossiliferous. * * * 

The Aturian h well represented at Cardenas and at Santa Catarina, in the State of San 

Luis Potosi, between the capital and Tampico, by a fauna very rich in lamellibranchs: Gryphcea 

vesicularis Lamarck, Coralliochama G. Boehmi Bose, Biradiolites cardenasensis Bose, Radiolites 

austinensis Roemer, Exogyra costata Say; and containing also gastropods-different species 

of Cerithium, Turritella, Actreonella, Nerinea; one finds also Orbitoides and a large number of 

corals. An Actreonella fauna is found likewise in the environs of Monterey, in Nuevo Leon, 

but on approaching Coahuila Actreonella. disappears and Exogyra costata Say, Exogyra ponderosa 

Roemer, Ostrea glabra var. wyomingensis Meek and Hayden are predominant. The Senonian 

is found at Las Esperanzas, in Coahuila, where it is formed of calcareous and marly sandstones 

which alternate with shales, and is terminated in the upper part by glauconitic sandstones 

characterized by Sphenodiscus lenticularis, lamellibranchs, and gastropods. * * * In the 

south of Mexico the Senonian has not yet been encountered, and it is probable that erosion 

has destroyed it in certain places where it may have occurred. 

Sapper described Upper Cretaceous strata of the Province of Chiapas, but they 

have been assigned to the "Meso-Cretaceous" (Comanche) by Bose. (See Chapter 

XIV, p. 589.) 

Regarding the Upper Cretaceous of Mazapil, see quotation from Burckhardt in 

Chapter XIII (p. 554). 

Local descriptions of the Upper Cretaceous of Mexico and its relations to the 

Lower Cretaceous strata will be found, together with lists of fossils and correlations 

with European divisions, in the "Guide des excursions" 8 of the tenth international 

geological congress, at Mexico, in the following sections: 

No. 29. Environs de Monterrey et Saltillo.-Bose. 

No. 26. Geologie de la Sierra de Mazapil ot Santa Rosa.-Burckhardt. 

No. 24. Geologie de la Sierra de Concepcion del Oro.-Burckhardt. 

No. 23. Excursion dans les environs de Parras.-Bose. 

No. 27. Les gisements carboniferes de Coahuila.-Aguilera. 

G 12, H 11. LOWER CALIFORNIA. 

The "Mesa sandstones" of Lower California, which were described by Gabb on 

very slight evidence as possibly Miocene, are here assigned to the Upper Cretaceous 

on the evidence of their similarity to the sandstone of that age which occurs at Ensenada. (Seep. 647.) From Gabb's account of the peninsula 350 we quote as follows: 

The three geographical divisions into which I have separated the peninsula are dependent 

for their peculiar features on their geological stmcture. Tho rough mountains of the south are 
UPPER CRETACEOUS. 645 

almost wholly granite, the table-lands of the middle are made up of nearly horizontal sandstones 

and volcanic rocks, while the more northern portions combine the ragged and irregularly disposed ridges of the south with occasional flat-topped mountains, capped by rocks of sedimentary 

or eruptive origin. 

· All of the higher ridges of the southern extremity of the Territory are made up of granites 

and syenites, and formed, during the deposition of the heavy bedded Mesa sandstones, an island 

of considerable height and very irregular outline. The structure of these mountains is so simple 

that a further description is unnecessary. It is not until within half a mile south of the mining 

town of San Antonio that any change in the geology occurs. Here mica slate is encountered for 

the first time, and forms a belt several miles wide, and running from Todos Santos, on the southwest, past San Antonio and Triunfo, northeast. It probably extends into the Cacachilas Range 

and forms there, as at the other mining districts, the country rock of the metalliferous veins. 

Beyond the mica slate again, on the road between Triunfo and La Paz, granite is encountered, 

making the face of the range and extending to near the latter town. 

In all of the valleys scattered through these mountains and in some of the lone hills on the 

east side of the peninsula are sedimentary formations of a comparatively late geological age. 

At Santiago I was informed that 3 miles northeast of that place is a locality where large fossil 

oysters occur in great abundance, and that they are collected and burnt for lime. I had no 

opportunity of visiting the locality, a circumstance which I have regretted ever since. A short 

distance farther northeast, near the coast, at a rancho called Los Martyres, is a high hill of sandstones, without fossils, dipping to the westward at an angle of about 15°. From its general 

appearance it is, in all probability, of the same age as the sandstones which make up the mesas 

above La Paz. In none of these sandstones have I ever succeeded in finding fossils by which to 

obtain a clue to their geological age. They probably, however, belong to the same group as the 

Miocene sandstones of Upper California. They have in many respects the same lithological 

characters and bear the same relations to the granites that those rocks hold where we have had 

an opportunity of proving their age. Besides this very doubtful testimony, there is still another 

item of evidence which, in the absence of any better, should have some weight. Mr. John 

Xantus, an able collector, sent from Cape San Lucas to the Academy of Natural Sciences of 

Philadelphia a few fossil oysters, which, if my memory does not deceive me, l_>elong to a species 

very characteristic of the Upper Californian Miocene-0. titan Conrad. Should I be correct, 

this is important, though half a dozen years is a long interval, particularly if one had never 

devoted any especial attention to the specimens remembered. 

With so little evidence of their age, therefore, I have hesitated about pronouncing a decided 

opinion, preferring to leave it an open question, trusting that some future explorer will be 

more lucky than myself and discover fossils from which these rocks can be assigned to their 

proper place in the geological scale. In consequence of the difficulty I have adopted the 

provisional name of Mesa sandstone in speaking of the formation. 

After leaving the granitic ranges south of La Paz the whole appearance of the country 

changes, and with it the geological structure. The granite itself has disappeared, only to show 

itself as one or two insignificant outliers, and in its place come enormous deposits of sandstones 

forming flat-topped mountains, ragged and precipitous along the east coast but sloping off so 

gradually toward the Pacific as to merge insensibly into the broad, low plains of the west. 

Pretty regularly bordering the west coast and occurring occasionally along the gulf are deposits 

of post-Pliocene age, in places filled with and almost made up of the casts or shells of Mollusca, 

still living in the adjoining waters. Penetrating both these formations, and often capping one 

or the other or both indiscriminately, are deposits of volcanic origin. These volcanic rocks 

usually occur as dikes or broad superficial sheets which have been spread over the top of the 

mesa subsequent to the deposition of the post-Pliocene, and are by no means uniform either in 

thickness or in the manner of their distribution. Very few volcanic cones exist. Almost the 

only ones are the volcano of the Virgines, north of Moleje, and a series of cones and ridges extending westward to near San Ignacio. Elsewhere the eruptions appear to have taken place in the 
646 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

form of long fissures, forming dikes, which, having spread their surplus over the surrounding 

plains, have closed, never again to reopen. In this manner immense areas have been covered 

with caps of eruptive rocks often 100 feet thick, the source of which is now entirely hidden, an 

occasional hint only existing in the denuded section of some bluff where the dike has been cut 

through by the agency of running water. 

The post-Pliocene rocks usually lie on the lower margins of the mesa in such a manner as 

to show that they were deposited during the period of elevation of this portion of the peninsula. 

The older Mesa sandstones are usually so little disturbed that the two formations seem conformable, though sufficient evidence exists to prove that the elevating force had been acting for a 

long time before the oldest beds of the newer formation were deposited. This later series consists of fine-grained argillaceous sandstones and shales, some coarser light-gray sandstone, and 

lastly a thin bed, highly fossiliferous, as are also some of the earlier strata, but the latter highly 

calcareous. Where the series remains unbroken, this last stratum is always the highest, and it 

is nearly made up of the casts of living species of shells, Ostrea cummingii being almost the only 

one retaining its structure. At Purissima, on the west slope, the Mesa sandstones have been 

folded in a series of long and graceful undulations, the tops denuded to a nearly straight line and 

the post-Pliocene lies unconformably capping the surface. On the opposite side of the mountains bordering the gulf there are still more marked instances of unconformability, which will be 

described in their proper place. 

The Mesa sandstones are easily distinguished from the overlying rocks by their coarser 

grain, greater compactness, and above all by their being highly metamorphosed along the greater 

part of their eastern margin. Another marked feature is the presence of large quantities of 

bowlders and pebbles of volcanic rocks embedded in them, sometimes to such an extent as to 

form even a preponderance of the bulk of some strata. These bowlders are uni:liormly small and 

very much rounded near the west coast wherever the rock is encountered, and increase in size 

toward the vicinity of Loreto, or rather toward that part of the coast a little below Loreto, in 

such a manner as to point unmistakably to this region for their origin. Not only does the size 

increase, but in the same ratio is the increase in number and the decrease in the amount of 

attrition to which they have been subjected. The lithological characters vary markedly from 

those of any eruptive rocks encountered in place on the peninsula; no similar rocks have been 

discovered between the Mesa sandstones and the underlying granite, and the only reasonable 

conclusion which can be arrived at is that they must have been derived from a body of land 

which formerly lay in that region now occupied by the gulf, and somewhere in the vicinity of or 

a little south of Carmin Island. 

Another striking feature of this region is the peculiar manner of the elevation of the mesa. 

It has not been lifted by an evenly distributed force; not, like most mountain chains, by a folding 

along a given axis. The eastern side seems to have felt this force almost alone, the elevation 

of that portion lying to the west seeming to be due almost as much to the rigidity of the rocks 

as to the extension westward of the uptilting power. More properly speaking, the great force was 

exerted very nearly parallel with what is now the coast line of the gulf, and from there toward 

the Pacific this agency diminished so gradually as to produce no breaks or even foldings worthy 

of mention. We thus have the whole width of this portion of the peninsula tilted up by its 

edge from coast to coast, so that traveling eastward one can hardly realize the rise until, within 

15 or 20 miles of the coast, he finds himself on the verge of a precipitous descent of from 2,000 to 

3,000 feet in height. This eastern escarpment extends from near La Paz to near Moleje, with 

but few interruptions, and exhibits nearly everywhere the projecting edges of nearly horizontal 

beds of sandstone, sometimes unaltered, but usually metamorphosed. 

The preceding description of the peninsula by Gabb should be supplemented 

by consulting the articles by Lindgren, and by Emmons and Merrill. Lindgren's 

account is quoted below and the map follows his inference in placing the "Mesa 

sandstones" in the Cretaceous. 
UPPER CRETACEOUS. 647 

Emmons and Merrill 323 sum up the work of previous writers and give their own 

observations in latitude 30°. The section which accompanies their article has been 

compiled in the map of North America, as is shown by the details of distribution of 

granitic and metamorphic rocks in that latitude. If we knew the distribution, 

the great mass of granite which is shown as the backbone of the peninsula would 

undoubtedly prove to be broken up by areas of metamorphic rocks of greater or 

less extent, which are presumably to be assigned to the Mesozoic or Paleozoic, 

and by patches of the " Mesa sandstones'' and volcanic rocks which overlie the 

intrusive and metamorphic rocks that cap the peaks and ranges. 

Lindgren 536 gave the following account of Cretaceous strata at Ensenada: 

The first evidence of the existence of Cretaceous strata in Lower California was furnished 

by a few fossils sent to the National Museum by Mr. C. R. Orcutt, of San Diego, who found 

them at the southern shore of Todos Santos Bay. 

Dr. C. A. White has mentioned and described those fossils. * * * The exposures are 

not very extensive; they are, in fact, limited to a patch about 3 miles long east and west and 

1 mile north and south, on the northern side of Punta Banda. This promontory consists mainly 

of old porphyritic rocks, against which the Cretaceous strata have been deposited; they form 

a perpendicular sea cliff about 50 feet high and extending for about 2! miles along the shore; in 

most places post-Pliocene gravel and sand cover the top of the cliff, but Cretaceous exposures 

may be found a little higher up, protruding from the later, covering beds. 

The strata consist of a series of yellow coarse sandstones, interstratified with heavy conglomerates of well-rolled pebbles up to a foot in diameter, evidently petrographically identical 

with the massive rocks forming the peninsula and derived from them. * * * 

In these heavy sandstones, generally void of fossils, there are at intervals strata 2 to 4 

feet thick composed entirely of the calcareous shells of Coralliochama, accompanied by a small 

specimen of Cerithium. The fauna is decidedly monotonous, and but a few new forms were 

found. 

There are strong reasons for believing that this isolated Cretaceous mass is but the first of 

a series of similar strata farther south, and I only regret that I could not extend my trip in that 

direction. On Todos Santos Island, about 12 miles from the coast, there appears to be an 

exposure of sandstone similar to that of Punta Banda. At the harbor of Santo Tomas, 40 

miles south of Ensenada, a steep sandstone cliff, containing many and large pebbles, is said to 

form the coast. Similar sandstones occur at Cape Colnett, about 70 miles south of Ensenada. 

From here it is not very far to where the Mesa sandstones begin, and it appears to me quite 

probable that these also will eventually be .found to belong to the Cretaceous period. Gabb 

has followed the sandstones more carefully on the eastern than on the western coast and states 

expressly, regarding the former, that they continue to skirt the coast for a long distance north 

of the end of the second or middle division, where they occupy the whole peninsula. His 

description of the appearance of the sandstone corresponds very well indeed with the Todos 

Santos occurrence. It must be remembered that Gabb did not determine the age of the Mesa 

sandstones, but only conjectured, based on a very slight clue, that they were Miocene. At the 

san'le time he describes the quite extensive metamorphism which has affected the strata in certain regions. This fact can not well be brought into accord with such a comparatively recent 

age as that to which he assigns the rocks. At least nothing has been observed in Upper 

California indicating that any extensive metamorphism has occurred so recently.a 

The strata which occur at Todos Santos Bay were placed in the Wallala group of 

White, which has since been recognized as lower Chico. 

a The character of the Miocene ~eries recently found in the southern part of the peninsula at Boleo * * * 

appears to be very different from the Mesa sandstones ancl from the Todos Santos occurrence; it also incloses volcanic 

materials of andesitic and basaltic character. It is probable that the shells referred to above (Ostrea) came from a 

series equivalent to this and not from the Mesa sandstone. 
648 INDEX TO THE STRA'fiGRAPHY OF NORTH AMERICA. 

G-H 13-14. COAHUILA AND ZACATECAS, MEXICO. 

The Upper Cretaceous of northeastern Mexico contains important coal measures. The stratigraphy and structure of the State of Coahuila have been described 

by Aguilera, 10 who tabulates the stratigraphy as follows: 

.eries. Stage. Substage. 

Pliocene. I 

I 

i ~--- ~--

I 

E ocene. i 

', 

-------I 

I 

j Laramie. 

Neoc 'retac eous. 

M esoc .retac . eons. 

I 

1--

I 

I 

I 

Montana. 

----~-

Colorado. 

Edwards 

limestone . 

----

Eagle 

Pass. 

Fox Hills 

and Fort 

Pierre. 

Niobrara. 

1 Denton. 

---

I 

Stratigraphy of Coahuila, Mexico. -

I 

Division. Plains. Sierra de Santa Rosa. 

- -~- --------

Uvalde:. Conglomeratic limestone. 

Reynosa. Yellowish limestone. 

,,-

Oyster beds in shales ....... 

Variegated shales ............ 

Removed by erosion. 

Do. 

Glauconitic sandstones with Do. Danien. 

impressions of plants and Exposed only in moderate 

silicified wood. thickness in a few places 

---·- at foot of the Sierra. 

Carbonaceous shales on the Shales with workable beds Aturien. 

Las of coal. slopes; of slight thickness. 

Esperan- ' 

zas. Yellowish fossiliferous cal- Calcareous shales with Era- careous sandstones, with gyra costata on the SUlllthin beds of shale and mit of the Sierra. 

limestone, also fossilifer- Fossiliferous shales of M uz- Emscherim 

ous. quiz (Montana and Colorado ). 

Darro- Diu ish shales without foster:in. sils. 

-------

I Calcareous shales with Ina- I T Peyotes. ceramus labiatus, Ptycho- 1 Lo:ver 

dus Whipley. n1en. 

I 

Santa Rosa . Compact ash-gray limestone.~ Cenomanie 

In describing the strata Aguilera says: 

1 (?). 

uron. 

The sedimentary rocks are marly sandstones, of bluish and reddish colors, and also limestones of various tones of gray, including argillaceous shales that are gray and black in the 

upper part and bluish in the lower part of the entire mass of the formation. The sandstones 

arc in general of fme grain. There is a bed, varying in thickness from 5 to 30 meters, which 

consists of conglomerate of large limestone pebbles. 

* * * * * * * * * Throughout the broad region in which the coal-bearing strata of tlw Cretaceous are developed in Coahuila, one may distinguish the following divisions: At the base the Barroteran, 

and then, following in succession upward, the Esperanzas formation comprising the fossiliferous beds of Esperanzas, Muzquiz, and other places upon the slopes of the mountains; the 

Sabinas, consisting of the glauconitic sandstones of the village of Sabinas, and topped by the 

shales which contain a bed of Ostrea cortex; the Arroyo Tulillo for the beds of Ostrea glabra 

Meek. To these may be added the Peyotes division with beds containing Inoceramus labiatus 

Schlotheim, etc. 

Burckhardt 109 has classified and described the Jurassic and Cretaceous of the 

Sierra de Mazapil district, in the States of Zacatecas and Coahuila, in the "Mesa 

Central" of Mexico. (See table in Chapter XIII, pp. 552-553.) 
UPPER CRETACEOUS. 649 

H 14. SOUTHERN TEX.~ . .S. 

In describing the Upper Cretaceous of the Rio Grande section near Eagle Pass, 

Vaughan 832a adopted with slight modifications the classification of Dumble 294 and 

distinguished the Eagle Ford formation, Austin chalk, Upson clays, and Eagle 

Pass formation. The Eagle Ford rests upon the Buda limestone of the Comanche 

series. H is composed of fiaggy argillaceous limestones, in places separated by 

calcareous shaly layers. The thickness is 250 feet or more. 

The Austin chalk is a soft, chalky, argillaceous white limestone, composed in 

part of Foraminifera. Its thickness is undetermined but was estimated by Dumble 

at 1,.500 feet. 

The Upson clays are described as yellow at the base and as containing calcareous septaria; the upper portion is a clay shale. The thickness was estimated by 

Dumble at 700 feet. 

The Eagle Pass formation is described as comprising three members, called 

San Miguel beds, Coal series, and Escondido beds. These consist of sandstone and 

clay with coal beds, of which Vaughan gives many detailed sections. An artesian 

well near Eagle Pass penetrated 1,512 feet of strata, of which Vaughan assigns 767 

feet to the San Miguel beds and 7 45 feet to the Coal series. A summary of the 

formation is given as follows: 

Resume of characters and thickness of the Eagle Pass formation. 

Escondido beds, composed of sandstones and clays, with many fossiliferous horizons, exposed Feet. 

for 26 miles below Eagle Pass. ______ ...... _________________________ .. ___ ..... _ ..... _____ 2,600 

Coal series, as determined by artesian well bore, which be;~ins in the uppermost bed ..... _____ 900 

San :Miguel beds, the lower 600 feet of the artesian well bore and the thickness of sandstone 

exposed in the hills north of the Carter ranch, 10 miles above Eagle Pass (200?) .. _ _ _ _ _ _ _ _ _ 800 

4,300 

Aguilera 10a has divided the Upper Cretaceous in the coal-bearing area of 

northern Coahuila, south of Eagle Pass, into the Sabinas, Las Esperanzas, Barrateran, and Peyotes formations. 

In the Uvalde area, Texas (90° 30'-100° west longitude and 29°-29° 30' north 

latitude), according to Vaughan, 833a the Upper Cretaceous rests upon the Buda 

limestone and exhibits the following divisions: 

Generalized section of Upper Cretaceous sedimentary rocks of Uvalde quadrangle, Texas. 

I 

Formation. 

I 

! Pulliam formation. 

Anacacho formation. 

Austin chalk. 

Thickness 

(feet). 

100-200 

:~00-400 

3G0-400 

Character of rocks. 

. . 

' Coarse and fine grained yellowish and brown sandstones and 

clay; asphaltum horizon near top. Bed of Ostrea cortex Conrad at top. Sphenodiscus pleurisepta (Conrad) also occurs near the top. 

Yellow, usually argillaceous but sometimes arenaceous limestones, with beds of yellow marl or clay. The limestones are more developed in the western portion of the quadrangle and 

the chy in the e:tstern portion. Fossils: Radiolites sp., 

Sphmrulites sp. Exo;nra lxviuscula Roemer, Exogyra ponderosa Roemer, Gryphl£a vesicularis Lam., Baculites sp. 

White and yellowish chalk, with some marly beds. Fossils: 

Gryphxa aucella Roemer, Inoceramus cf. digitatus Sowerby, 

Jlortoniceras texanum (Roemer), Pyrina parryi IIall. 

1---------:,-----------------------------

Eag_le __ F_or_d_f_o_rm_a_t_io_n_. ______ ..!.___ __ 7.>+ I __ Ar~!~aceous and calcareous~:~s.:_ _________________ _ 
650 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

H-I 14. NORTHEASTERN TEXAS. 

According to Hill, 445a the Upper Cretaceous of northeastern Texas is characterized as follows: 

The upper Cretaceous or Gulf series rests unconformably upon the Comanche series and 

may be divided into five conspicuous formations, the beds of which grade into one another by 

imperceptible transition. The lowest of these north of the Brazos, the Woodbine, consists of 

ferruginous sands and clays. Above this is a formation characterized by bituminous clays, 

the Eagle Ford. Then follows a conspicuous formation of chalk, the Austin chalk. Succeeding 

this is a formation of marly clay, the Taylor marl. The uppermost formation, the Navarro, is 

composed of unindurated beds of glauconitic sands, clays, and a little chalk, as will be described 

later. There is no sedimental break between these formations, the whole series being practically continuous. All are characterized, with certain exceptions, by their general lack of 

consolidation, little or no hard rock being found. The beds grade into one another so gradually 

that partings are mappable only with the greatest difficulty. * * * 

The Woodbine formation apparently rests unconformably upon the Grayson marls and 

Main Street limestones of the Denison beds of the Washita division, at the top of the Comanche 

series. The upper beds pass, by inseparable transition, from sands into sandy clays and finally 

into the bituminous clays of the Eagle Ford formation. This transition is so gradual that no 

exact line of separation can be drawn between the Woodbine and Eagle Ford formations. 1'he 

parting is arbitrarily established at the zone of Exogyra columbella, which is considered as the 

top of the Woodbine formation. 

The formation has a thickness of at least 600 feet in the northern section and diminishes 

southward until it disappears by thinning out and overlap at the Brazos. On Aquilla Creek 

north of Waco the formation is 45 feet thick. According to Taff, it is 200 feet thick in the 

Cleburne section. On Cottonwood Creek northwest of Hillsboro it is 95 feet thick. In the 

Fort Worth section its thickness is about 300 feet and in the Denison section about 500 feet. 

* * * * * * * * * 

The Eagle Ford formation is essentially a bituminous clay, accompanied in places by thin 

laminated clay limestones and nodular septaria of blue limestone. These clays are notable in the 

Texas section, where the other clay formations are mostly of a marly nature by reason of their 

bituminous character, resembling the shales of the Cretaceous formations of the Rocky Mountain 

region and the northern part of the Great Plains. Even these dark-blue clays become more 

calcareous in the upper layers and in the extension of the beds south of the Brazos, but north 

of that stream they form most of the medial and lower portion of the beds. From Dallas north 

the nodular septaria are of large size and abundant. In age these beds are identical with the 

Benton formation of the Meek and Hayden section. On Red River, in the Paris section, their 

thickness is estimated at 600 feet; in the Sherman section, 600 feet; in the Dallas section, about 

480 to 500 feet; near Midlothian, 350 feet; in the Waco section, south of South Bosque, 200 

feet; in the Austin section, 30 feet; on the N ueces, 200 feet. 

* * * * * * * * * 

The Austin chalk consists of beds of impure chalk containing 85 per cent or more of carbonate of lime, interstratified with softer beds of marl. It is usually of an earthy texture, free 

from grit, and when freshly exposed easily cut with a handsaw. Under the microscope the 

material shows calcite crystals, particles of amorphous calcite, and the shells of foraminifers, 

mollusks, echinoids, and other marme orgamc debris, such as usually constitute chalk formations. 

* * * * * * * * * 

Throughout the area included in this report the Austin chalk rests upon 5 to 10 feet of 

finely laminated and usually arenaceous, calcareous, argillaceous yellow to bluish material 

constituting the top of the Eagle Ford formation and ordinarily termed the Fish beds. The 

formation passes upward into the Taylor marls witliout stratigraphic break. Southeast of 

Waxahachie, at the upper contact or parting between the Austin chalk and the Taylor marl, 
UPPER CRETACEOUS. 651 

the marl rests directly on the massive upper strata of the chalk, the transition being very 

abrupt; but south of Waxahachie there are several feet of calcareous arenaceous marl intervening between the two divisions which are included with the chalk. 

The thickness of this formation is difficult to determine with accuracy. Southeast of 

McKinney it is 625 feet; at Waxahachie, 550 feet; and southeast of Sherman, Dallas, and 

Waco it is estimated to be very nearly 600 feet thick. At Austin, according to the log of the 

Manor well, it is about 410 feet thick, but the exact thickness has not been determined. 

* * * * * * * * * 

The Cretaceous section above the Austin chalk in the Black Prairie region of Texas is 

composed almost entirely of unindurated layers, fum rock strata being very few and exceptional. 

The beds are principally calcareous clays which weather so rapidly into a mantle of thick black 

soil that continuous sections of them can not be seen or measured with accuracy, and hence 

their thickness, sequence, and general character must be judged largely from well holes. These 

unindurated uppermost Cretaceous strata in places, as at Corsicana, are fully 2,000 feet thick. 

They can be differentiated, after a manner, into two general formations, the lower of which 

may be termed the Taylor and the upper the Navarro. In some places, notably in the northeastern corner of the State, the upper formation, which will be described later, is separable into 

several members. 

* * * * * * * * * 

The Taylor formation consists of calcareous clay marls which are locally known as "joint 

clays." These are blue-black in the substructure but weather into a deep regolith consisting 

of a whitish-yellow subsoil and a dense black soil which characterizes the main ''black waxy" 

belt of the Black Prairie. The regolith is jointed, laminated, and friable throughout, having a 

crackled appearance when dry. Because of their rapid surface disintegration the character of 

the unaltered beds is seldom seen except when their material is brought up by the well digger 

or is exposed in freshly cut ravines or creeks. · To the eye this clay marl is generally lacking in 

siliceous material, although a portion may be detected by chemical analysis. The bituminous 

matter which characterizes the Eagle Ford formation and the grains of glauconite which are 

found in the rocks of the overlying Navarro beds are also less notable. Their accessory 

constituent is lime, in a chalky condition. The marls are of fine consistency, compact, and 

apparently massive until their laminated character is developed by exposure. 

* * * * * * * * * 

Owing to lack of outcropping sections for measurement it is difficult to ascertain the 

exact thickness of this formation or to separate it from the overlying Navarro formation. In 

the latitude of Austin, as determined from the well at Manor, the beds are about 650 feet thick. 

In north Texas we have no reliable records by which to estimate their thickness. At Corsicana 

there are at least 1,500 feet of clays above the Austin chalk, a portion of which belong to the 

Taylor marls. Taff gives the Taylor marls nearly 1,000 feet in Williamson County, but this is 

probably overestimated. 

* * * * * * * * * 

The Navarro formation includes the highest beds of the Cretaceous which outcrop along the 

eastern portion of the Black Prairie region and of the northern margin of the Rio Grande Plain. 

This formation is the upward continuation of the Taylor marls, the one passing into the other 

by gradual transition. The chief lithologic differences are that the clays, chalks, and sands 

composing the Navarro formation contain more or less sand and glauconite, while the Taylor 

marls are apparently free from those substances. Besides these lithologic differences, there are 

conspicuous changes in the fossils. The latter become more plentiful in the Navarro formation 

and have the same character as those of the Upper Cretaceous of the New Jersey and Alabama 

regions, of which they are the equivalent and continuous beds, being especially marked by 

Gryphxa vesicularis, Exogyra costata, Ostrea larva, Sphenodiscus lenticularis, and numerous 

other forms. 

* * * * * * * * * 

In the southwest corner of Arkansas and in the Red River counties the uppermost Cretaceous beds show considerable stratigraphic differentiation, consisting of beds of glauconitic 
652 INDEX TO THE STRATIGRAPHY OF NOHTH AMERICA. 

clay marl, chalks, and glauconitic sands. South of the Sulphur Fork of Red River to tJw Colorado the beds consist almost exclusively of glauconitic sand and clay marls, there being only 

a few local occurrences of secondary limestone or arenaceous flrgs. 

I 15. NORTHEASTERN TEXAS, ARKANSAS, AND LOUISIANA. 

According to Veatch 83ScThe upper Cretaceous of Arkansas is composed of the following members, beginning with 

the lowest: 

l. Sands with bituminous laminated clays containing leaf impressions and lignite beds-the Bingen 

formation. 

2. Blue calcareous clay with Exogyra ponderosa-the Brownstown formation. 

3. White chalk-the Annona chalk. 

4. Calcareous clay or clayey chalk, with considerable greensand-the Marlbrook formation. 

5. Indurated sand, with thin calcareous and quartzitic layers locally called "water rocks," glauconitic 

in part-the Nacatoch sand. 

6. Dark calcareous clays, fossiliferous below, which pass upward without a sharp break into the 

sandy, lignitiferous lower Eocene beds-the Arkadelphia clay. 

The near-shore character of the Bingen sand is in such contrast to the overlying and rnderlying Cretaceous marls and in the outcrop is so similar to the overlying sandy surficial deposits 

of the late Tertiary that in Arkansas it has heretofore, with the exception of a limited outcrop 

near Morris Ferry, either been confused with the surficial deposits or been regarded as an outlier 

of the Lower Eocene beds, which it closely resembles lithologically.a 

This formation consists of white or brown sands t1nd clays containing some greensand and 

considerable lignite or lignitiferous matter, in which respect it differs from the overlying formations. 

* * * * * * * * * To the west and south the beds below the Brownstown and Taylor marls thicken rapidly, 

and the various sand beds encountered together in southern Sevier and Howard counties, Ark., 

become greatly separated by layers of clay. * * * 

The Bingen sand, while the lithological counterpart of the Woodbine formation, is apparently tho time equivalent of all the beds of the lower [upper] Cretaceous below the Brownstown and Taylor formations. 

* * * * * * * * * 

The Brownstown formation, into which the Bingen sand gradually grades, is well developed 

in the southern part of Sevier County, Ark., about Brownstown, from which place it takes its 

name. It is a blue or gray calcareous clay containing many fossil oysters and is characterized 

by the presence of the large oyster Exogyra ponderosa, whence it has sometimes been called 

the Exogyra ponderosa marl. * * * It is limited above by the Annona chalk and has a 

total thickness of 150 feet in the eastern part of the area and 600 feet in the western. 

* * * * * * * * * 

The White Cliffs chalk,b [so named] from the bluffs and village of that name on Little 

River, in the northeastern part of bittle River County, Ark., was renamed the Annona chalk c 

from the town of Annona, Red River County, Tex., because it was found that White Cliffs as a 

formation name had been applied by Powell d to certain Jura trias beds in Utah. It consists 

of white chalk, which at White Cliffs has a thickness of over 100 feet, but thins out rapidly 

to the east, disappearing entirely before reaching Okolona, where Taff has found only the chalky 

marl which, at the type locality, underlies it. 

a Hill, R. T., Ann. Rept. Geol. Survey Arkansas for 1888, vol. 2, 1888, pp. 56-58; Bull. Geol. Soc. America, vol. 5, 

1894, p. 309, Pl. XII; Twenty-first Ann. Rept. U.S. Geol. Survey, pt. 7, 1901, p. 195, fig. 21. 

b Hill, R. T., Ann. Rept. Geol. Survey Arkansas for 1888, vol. 2, 1888, pp. 87-89. 

cHill, R. T., Ball. Geol. Soc. America, vol. 5, 1894, p. 308; Twenty-first Ann. Rept. U. S. Geol. Survey, pt. 7, 

19::Jl, p. 340. Hill's spelling Anona has been changed to Annona, the spelling used in the Postal Guide and on Hill's 

map of the Black and Grand prairies of Texas, 1899 (Twenty-first Ann. Rept. U.S. Geol. Survey, pt. 7, 1901, Pl. LXV). 

d Geology of the Uinta Mountains: U. S. Geol. and Geog. Survey Terr., 2d div., 1876, pp. 41, 51, 151. 
UPPER CRETACEOUS. 653 

The Annona chalk is succeeded by a series of blue, chalky, somewhat glauconitic marls, 

in places impure chalk [the Marlbrook formation]. * * * About 200 to 300 feet above the 

base of this formation is a very chalky layer 20 to 50 feet thick, which has been called the 

Saratoga chalk marl or the Saratoga formation.a * * * The thickness of the Marlbrook 

formation ranges from 750 feet at Texarkana to 50 feet or less at Arkadelphia. 

Above the Marlbrook marl is a series of sandy beds which are of vast economic importance 

to a strip of country along the Iron Mountain Railway between Arkadelphia and Texarkana, 

since they are the source of the main water supply of that region. Like the other sandy beds 

of the Cretaceous, at the outcrop they are distinguished with difficulty from the surficial sands 

that mantle the region. * * * · 

The outcrop at N acatoch Bluff, on Little Missouri River, in Clark County, is one of the 

most complete exposures occurring along tllis belt and shows the calcareous and quartzitic 

rocks which, when encountered in wells, are called "water rocks." 

Section of Nacatoch Bluff on Little Missouri River, Clark County, Ark. 

Feet. 

1. Slope not well exposed; seems to be composed entirely of chert and quartz graveL __ ..... 20 

2. Ledge of fossiliferous arenaceous l,imestone, containing many large fossil shells: Exogyra 

costata, Pectunculus sp., and Ostrea subspatulata ............... _ . _ . __ . . . . . . . . . . . . . . . . . . 1 

3. Sand ........................... _ ................ _ ..... _ ........ _ ............. _....... 10 

4. Very impure sandy limestone or calcareous sandstone, with many imperfect fossils....... .1 

5. Sand ..... _ ...... _ . _ . _ ............................ _ ........... _ .... _ ......... _,. . . . . . . . 4 

6. Hard fossiliferous calcareous sand[ tone. ______ ...................... _. _ ... _ ............ _. . 5 

7. Sand ... _ ... _ ... _._ ....... _._._ ... __ . __ ._._ .... _._._._._ ........... __ ._ ......... __ ._. 5 

8. Slope on which landslip masses render positive determination difficult; seems to be composed of sand .... _ . _ . _ .......... _ . _ ........... _ _ . ___ . _ ..... _ ... _ . _ ......... _ . _ . _ 25 

Level of Little Missouri River. 

* * * * * * * * * 

The dark laminated clays which overlie the Nacatoch sand and form the ''blue dirt" of 

the well drillers along the line of the Iron Mountain Railway from Arkadelphia to Texarkana 

were named by Hill in 1888 the Arkadelphia shales, from the outcrops at Arkadelphia, Clark 

County. b These beds contain uppermost Cretaceous fossils for 100 to 200 feet above the 

N acatoch sands, the fossil-bearing beds being well developed on Yellow Creek 3 to 4 miles 

northwest of Fulton, 5 to 6 miles north of Hope, north and northwest of Emmet, and at Arkadelphia. Thus far no fossils have been found in the upper portibn of this formation, which 

extends without any apparent break to the Eocene sand beds forming the sandy hills (the crest 

of the Sulphur Wold) south of the Iron Mountain Railway. This absence of fossils, together 

with the fact that the Midway (Eocene) formation, though commonly characterized by limestones, contains dark-colored clays, makes the exact determination of the top of the Cretaceous 

in this section particularly difficult. 

* * *. * * * * * * 

The total thickness of the Arkadelphia clay, excluding the beds which appear to be stratigraphically Eocene, is from 200 to 300 feet at Arkadelphia, 500 feet at Lanesburg, 500 to 600 

feet at Hope and Spring Hill, and 500 feet at Texarkana and Shreveport. 

I 16. WESTERN TENNESSEE. 

The Cretaceous of western Tennessee comprises the Coffee sand member of the 

Eutaw formation, the Selma chalk ("Rotten limestone"), and the Ripley formation. The deposits are described by Safford 687 c and Glenn. 368 The section does 

not differ materially from that in Mississippi.891a (See p. 654.) According to 

recent field studies by L. W. Stephenson the Coffee sand member represents all of 

the Eutaw formation that is present in western Tennessee. 

a Branner, J. C., Trans. Am. Inst. Min. Eng., 1897, pp. 42-63; Taff, J. A., Twenty-second Ann. Rept. U. S. Geol. 

Survey, pt. 3, 1902, pp. 714-723. 

b Ann. Rept. Geol. Survey Arkansas for 1888, vol. 2, 1888, pp. 53-56. 
654 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

I 16-17, J 16. EASTERN GULF REGION, GEORGIA, AND SOUTH CAROLINA. 

As a result of the recent studies of the Coastal Plain of the United States, conducted in cooperation between the Federal and the State geological surveys, data 

have been procured on the stratigraphic and age relations of the several Cretaceous 

formations. L. W. Stephenson contributes the following review of the literature 

and discussion of the subject: 

C. A. White 891 in 1891 published a resume of the literature on the Cretaceous of these 

areas to that date. The more important previous investigators were Tuomey;812 Winchell,943 

and Smith and Johnson 750 in Alabama, Hilgard 438• 439 in Mississippi, Safford 688• 687 in Tennessee, 

and Ruffin 682 and Tuomey 811 in South Carolina. 

The principal contributions to the geology of these regions, since the publication of those 

enumerated by White,S91 have been by Langdon,S20 Smith, Johnson, and Langdon,751a Crider,178a 

Glenn,S69a Sloan,743• 7440 and Veatch.842 

A table which sets forth in condensed form the present writer's views regarding the age relations of the lithologic divisions heretofore recognized in the region is inserted opposite to enable 

the reader to understand more clearly the following discussion of past and present interpretations. 

In 1860 Eugene W. Hilgard/38a State geologist of Mississippi, differentiated four major divisions in the Cretaceous deposits of that State. These were, in ascending order, the Eutaw 

group, Tombigbee sand group, Rotten limestone group, and Ripley group. 

His Eutaw group rests upon Carboniferous rocks and includes all the Cretaceous deposits 

below the Tombigbce sand. These deposits consist of "bluish-black or reddish laminated clays, 

often lignitic, alternating with and usually overlain by noneffervescent sands, mostly (though 

not always) poor in mica, and of a gray or yellow tint. Contains beds of lignite, very rarely 

other fossils.'' 438b 

Hilgard's reason for adopting the name "Eutaw group" is given in the following quotation: 

"I adopt this name in view of these beds having been first examined in detail and recognized 

as being of Cretaceous age, by Tuomey,a near Eutaw, Ala., where they are characteristically 

developed." 4380 

The type region of the Tombigbee sand is in the vicinity of Columbus, in Lowndes County, 

Miss., where the beds are mapped as a belt 15 or 18 miles wide. The type exposures occur in 

bluffs of Tombigbee River." To the north of Lowndes County the Tombigbee belt is represented as narrowing down to a strip 2 to 4 miles wide, with a corresponding widening of the 

Eutaw area. By thus narrowing the Tombigbee belt, what Hilgard actually did was to run his 

Eutaw-Tombigbee boundary line obliquely across the strike of the beds so that to the north of 

the line he represented as belonging to the Eutaw a thickness of strata which correspond in age 

and stratigraphic position to the lower two-thirds or three-fourths of the Tombigbee as mapped 

south of the line; indeed the sections given as typical of the Eutaw are within these northward 

Tombigbee representatives. 

In 1887 Eugene A. Smith, State geologist of Alabama, and Lawrence C. Johnson 750a published a classification of the Cretaceous deposits of Alabama, the divisions recognized being, in 

ascending order, the Tuscaloosa formation, Eutaw formation, Rotten Limestone, and Ripley 

formation. They described the Tuscaloosa formation as consisting of at least 1,000 feet of 

"purple and mottled clays interstratified with white, yellowish-white, pink, and light-purple 

micaceous sands, and near the base of the formation dark-gray, nearly black, thinly laminated 

clays, with sand partings." The Eutaw formation is described as "a series of laminated sands 

and sandy clays at least 300 feet in thickness." 

If only those parts of the area in Mississippi immediately west of the Alabama line, mapped 

by Hilgard respectively as Eutaw and Tombigbee, are considered, his Eutaw division corresponds almost exactly to the Tuscaloosa formation of Smith and Johnson, and the Eutaw divia Tuomey's account of the beds near Eutaw to which reference is made is given in First Bienn. Rept. Geol. Survey 

Alabama, 1850, pp. 118-120.-L. W. S. 
Correlation of the Cretaceous deposits of the eastern Gulf region and of the Oarolinas.a 

[By L. W. Stephenson.] 

--------~~-~----~-------------------,------------------,-----------------~-----------------~------··------------,----------------------,----·-------------------,----------------------,----------------------

l I 

Kentucky and Illinois. Tennessee. Northern Mississippi. Western Alabama and 

east-central .Mississippi. 

Eastern Alabama, including Central Alabama. immediate Chattahoochee Western Georgia east of immeregion in Georgia. diate Chattahoochee region. 

----------+------------1--------------l--------------l---------------------------l 

Eocene. Eocene. Eocene. Eocene. Eocene. 

Absent. Absent. Absent. Absent. Absent. 

----------l---.---------l-----------1-------------\--·----·--------

Ripley formation 

(shallow-water 

phase). 

Shallow-water 

phase. 

Marine phase. 

Selma chalk (impure 

phase). 

Coffee sand member of 

Eutaw formation. d 

Ripley formation (marine phase). 

Selma chalk. 

Coffee sand mem- ber.d 

Selma chalk. 

l Ripley formation. b 

1---------

Selma chalk. 

Eocene. 

Ripley formation. b 

Eocene. 

Providence sand mem- ber. 

Typical marine beds. 

Cusseta sand member. 

Central Georgia. 

Eocene. 

Providence sand mem- ber. 

Cusseta sand member. 

g 

] ...... ················ ·············· 1-----,.---------------l·------,-----------------l------.---------------------l·-----+---------------------l ~~~-~~~~-~ 

Absent. 

Absent. 

Tombigbee sand 

member. 

Laminated sands 

and clays. 

Tuscaloosa formation. 

Absent. 

Tombigbee sand 

member. 

Laminated sands 

and clays. 

Tuscaloosa formation. 

Tombigbee sand 

member. 

........ ·······-···· ·····---------· 

Laminated sands 

and clays. 

Tuscaloosa formation. 

ci Tombigbee sand mem- .s her. c ..., 

cl 

s ... 

'" 0 

- Laminated and massive !;:; 

...., cl sands, clays, and ;; marls. 

[;4 I 

Absent. 

_g 

..., 

cl 

§ 

0 -!;:; 

cl ..., 

;; 

[;4 

Tombigbee sand mem- ber.c 

Laminated and massive 

sands, clays, and 

marls. 

Absent. 

Absent. 

Absent. 

----~-----------------l-----------------------·1-----------------------------------------·l---------------------l,~~~~~-~~~~~~~~~~-~~ 

Absent. Absent. I Absent. Absent. Lower Cretaceous.! Lower Cretaceous./ 

~ 

Lower Cretaceous.! 

South Carolina. 

Eocene. 

Absent. 

Peedee sand. 

§ Typical irregularly bed- -~ ded sands and clays. 

s 

.£ 

~ 

"' ... Q 

~ ~ Middendorf arkose 

member . 

Absent. 

Lower Cretaceous. 

Crystalline rocks. 

North Carolina. 

Eocene. 

Absent. 

Peedee sand. 

Black Creek formation. 

Absent. 

Patuxent formation.g 

Crystalline rocks. 

a For extension of the correlation northward, seep. 612. b A series of nonchalky equivalents of the Selma chalk referred by Langdon to the Ripley. c Included by Langdon in his Ripley group. 

d Correlated by Safford and subsequent investigators with the Eutaw formation, but now considered to represent only the upper part of the Eutaw. 

f Correlated by Langdon and others with the Tuscaloosa formation (Upper Cretaceous) of central and western Alabama, but on the evidence of 

fossil plants now referred to the Lower Cretaceous. It has not been proved that this division is synchronous with the Patuxent ("Cape Fear") 

formation of the Carolinas, as indicated in the table. 

g Correlated with the Patuxent formation on physical evidence only. Since the extension of this name to include the "Cape Fear" formation e The stratigraphic position of the base of the Black Creek formation with reference to the eastern Gulf section has not been established with accuracy. of North Carolina some doubt has arisen as to the correctness of the correlation. 

~~~~Unconformity. . ..... Line of separation between members of a formation. 

48011°--12. (To face page 654.) 
UPPER CRETACEOUS. 655 

sion of those authors corresponds to the Tombigbee sand of Hilgard. However, the sections of 

the Eutaw described by Hilgard, all of which are north of Columbus in Mississippi, do not correspond to the Tuscaloosa formation but, as previously stated, represent a part of the northward extension of the Tombigbee division as mapped and hence correspond in stratigraphic 

position to a part of the Eutaw of Smith and Johnson. 

The essential difference between the Tuscaloosa and Eutaw divisions of Smith and Johnson 

may perhaps best be stated as follows. The Tuscaloosa consists of a series of sands, clays, and 

gravels in large part of shallow-water origin, characterized by irregularity of bedding and, where 

the conditions for their preservation were favorable, by the presence of fossil leaves. The Eutaw 

consists predominantly of glauconitic sand of marine origin which in approximately the lower 

two-thirds or three-fourths of its thickness contains subordinate lenses of dark clay and exhibits 

fine cross-bedding and in its upper one-third or one-fourth is made up of massive beds of glauconitic sand with calcareous sand beds in its upper part. So far as known no structural break 

exists between the Tuscaloosa and Eutaw formations, sedimentation apparently having been 

continuous from the one to the other. Nor has it been possible to recognize any sharp litho. 

logic line of separation between them, the change from the one kind of sedimentation to the 

other having been transitional. 

Beds representing the Tuscaloosa formation extend from western Alabama northward, 

occurring in a wide belt that includes the northwestern part of Alabama and a relatively narrow area in the adjoining northeastern part of Mississippi. The formation as a whole, however, becomes much thinner toward the north and disappears in the vicinity of the Tennessee 

State line. It is doubtful if, in the region of their outcrop, the Mississippi representatives of the 

division exceed a maximum thickness of 400 feet. Hilgard did not differentiate these lower beds 

of shallow-water origin from the higher beds of marine origin but included them in his Eutaw 

f0rmation, as shown by the map accompanying his report. 

The Mississippi representatives of the Eutaw formation of Smith and Johnson include, as 

previously stated, all of the Tombigbee sand and a part of the Eutaw group of Hilgard. 

Although the width of the Tombigbee belt as mapped by Hilgard immediately west of the Alabama line is 15 or 18 miles, corresponding to a thickness of 400 or 500 feet, the actual sections 

given by him in this part of the area are all near the western border of the belt and probably 

include only about the upper 150 or 200 feet of the strata mapped. Farther north in Mississippi 

beds which correspond in stratigraphic position to the lower two-thirds or three-fourths of the 

Tombigbee as mapped in Lowndes County are included by Hilgard in his Eutaw group, and 

among these are the sections which he indicated as typical of this division in Mississippi. These 

correspond in age and position to a part of the Eutaw division of Smith and Johnson, although 

in the intervening area in Lowndes County beds of the same age were mapped as Tombigbee. 

This confusion was due apparently to the fact that Hilgard failed to find in Lowndes County 

any of the beds of dark clay corresponding in position to those farther north, upon the basis of 

which he seems to have differentiated his Eutaw group. These clajs are of a resistant character and where they occur in stream bluffs form rather conspicuous exposures; but when the 

division as a whole is considered they constitute subordinate lenses only of deposits made up in 

the main of glauconitic sands. Such clay beds, however, do occur in Lowndes County, being 

exposed in the banks of Floating Turtle Creek a short distance east of Columbus. 

From the facts brought out in the above discussion it is apparent that a readjustment of 

the nomenclature as applied by Hilgard to the beds subjacent to the Selma chalk in Mississippi 

is necessary. The classification of the corresponding deposits in Ala bam a by Smith and Johnson 

is based on essential physical differences, namely, those _depending on origin. In Mississippi 

these differences were not recognized. It would appear, therefore, that the Alabama nomenclature is the more logical. For this reason, in the opinion of the writer, the name Tuscaloosa, 

which stands for the lower shallow-water portion of the series, should be extended to include the 

corresponding deposits in Mississippi. The name Eutaw, which in Alabama stands for the upper 

or marine portion of the series, can appropriately be extended to include the corresponding beds 
656 INDEX TO THE STRATIGRAPHY OF NORTH AMERlCA. 

in Mississippi, although this will mean the expansion of the term as Hilgard used it, to include 

tho Tombigbee sand above, and its contraction with reference to the Mississippi representativu> 

of the Tuscaloosa formation below. 

The name Tombigbee sand, however, if applied to the actual type sections of the division 

described by Hilgard and their equivalents, is expressive of a natural phase or subdivision of the 

Eutaw formation and is eminently worthy of preservation in the literature. If we disregard 

Hilgard's imperfect mapping, the sections of the Tombigbee sand described by him are all 

included within a thickness of strata which probably does not exceed 150 or 200 feet. Thus 

limited the division includes the uppermost massive, more or less calcareous and phosphatic 

beds of the Eutaw formation, as distinguished from the more irregularly bedded and more 

argillaceous portion of the formation beneath it. These upper, massive beds are traceable for 

many miles to tho north of Lowndes County in Mississippi and they extend eastward, with certain modifications, entirely across the State of Alabama into Georgia. They were recognized 

by Smith and Johnson, who spoke of them as the ''upper member of the Eutaw formation." 

This member, however, can not be sharply differentiated from the remainder or lower member 

of the formation, for massive lenses of glauconitic sand of greater or less extent occur in places at 

lower levels than the Tombigbee member proper, and where these appear in small exposures 

they-are not distinguishable from that member. 

The Eutaw formation as thus defined (including the Tombigbee sand member) extends 

from Alabama northward through Mississippi to the vicinity of th~ Tennessee State line, where it 

ends against the unconformably subjacent Paleozoic rocks. 

The term 11 Rotten limestone" was introduced by Alexander Winchell 943a in 1857. This 

name was the commonly accepted designation of this great body of chalk rock until1894, when 

Smith, Johnson, and Langdon 751 b proposed the geographic appellation Selma chalk, as a coname 

with 11Rotten limestone," and since that time the geographic term has been the accepted de:signation. It has been found that the Selma chalk makes up all of the Upper Cretaceous strata 

above the Tombigbee sand member in western Alabama and east-central Mississippi, where 

it has an approximate thickness of 1,000 feet, the terrane being overlain unconformably by 

Eocene strata carrying characteristic fossils from the eastern part of Marengo County, Ala., to 

the northern part of Noxubee County, Miss. To the north in Mississippi and to the east in 

Alabama the Selma chalk as such becomes thinner and in each direction finally disappears. 

The thinning of the formation is due, not to the actual thinning or disappearance of the beds, 

but to their replacement along the strike by nonchalky materials (sands, clays, marls, etc.) 

having the same age and stratigraphic position. In the region of its fullest development the 

formation is divisible on paleontologic grounds into two parts; the lower, embracing approximately the lower half of the formation, is most conspicuously characterized by the presence 

of Exogyra ponderosa Roemer; the upper, embracing the remainder of the formation, is characterized by tho presence of Exogyra costata Say, and carries a fauna which corresponds in a 

general way with that of the Ripley formation of northern Mississippi, though it contains fewer 

spemes. 

The Ripley formation, which in its type region in northern Mississippi conformably overlies 

beds of the Selma chalk, is not younger than the youngest of the Selma chalk beds where the 

latter are most completely developed in western Alabama and east-central Mississippi; on the 

contrary, it is of the same age as the upper 300 or 400 feet of the Selma, tho nonchalky, sandy, 

and argillaceous beds of the Ripley being the representatives in northern Mississippi of the 

upper part of the Selma chalk. To the north in Tennessee both the Selma chalk and the Ripley 

eventually lose their distinguishing lithologic characters, the former ~erging into marine 

and estuarine equivalents and the latter into shallower-water equivalents, probably largely of 

estuarine ongin. The Ripley formation with these lithologic modifications is traceable northward through Kentucky to the head of the embayment region in southern Illinois, to which limit 

the beds maintain their shallow-water characteristics. 

What has been said thus far applies more especially to the Cretaceous beds of the eastern 

Gulf region between central Alabama and J\Iississippi River. The conditions of deposition which 
UPPEH CRETACEOUS. 657 

prevailed in the region of the Chattahoochee Valley in eastern Alabama and western Georgia 

were, during much of Cretaceous time, markedly different from those existing farther west. 

The lowest Cretaceous division of the Chattahoochee region, the Tuscaloosa group of Langdon,520 was supposed by that author to represent the eastward extension of the Tuscaloosa of 

Smith and Johnson. The physical aspects and relations of these deposits, and the paleontologic 

evidence furnished by a collection of poorly preserved fossil plants from Old Fort Decatur, on 

Tallapoosa River, studied by E. W. Berry, have led both Mr. Berry and the writer to doubt the 

correctness of this correlation. It is believed that they are of Lower Cretaceous age and hence 

older than the Tuscaloosa formation. 

The Eutaw group of Langdon in the Chattahoochee region is approximately the eastward 

extension of the Eutaw of Smith and Johnson except that in the opinion of the writer, based on 

paleontologic evidence, it should have included at least 120 feet of the overlying beds which 

Langdon referred to the base of his Ripley group. The beds of the division exposed on Chattahoochee River are in the main of marine origin, although in places they exhibit in part the 

characters of shallow near-shore or estuarine deposits. To the northeast in Georgia they pass 

into shallow-water equivalents and eventually end unconformably against the underlying older 

terrane (Lower Cretaceous). 

The conditions which favored the deposition of chalklike rocks in central and western 

Alabama were entirely lacking in the Chattahoochee region, and we have in place of the chalk 

a series of marine sands and clays which as a whole are synchronous with the fully developed 

Selma chalk of western Alabama. The conditions unfavorable to the deposition of chalk, 

which at the beginning of Selma time existed only from Macon County eastward, gradually 

spread westward as Upper Cretaceous time proceeded, ending, so far as the reeord has been 

preserved, a short distance east of Tombigbee River in Marengo County, Ala. These nonchalky 

deposits of the Chattahooehee region were by Langdon referred in their entirety to his Ripley 

group. Reeent studies by the writer in this region have shown that Langdon's Ripley group of 

the Chattahoochee region is divisible on paleontologic grounds into two parts-a lower part 

carrying a number of species restricted to the lower one-third or one-half of the formation, and 

an upper part earrying a large number of speeies that do not range lower than the upper one-half 

or two-thirds of the formation, and characterized espeeially by the presence of Exogyra costata 

Say. These two parts, with the exception of the Tombigbee representatives at the base of the 

lower one, correspond to the two parts recognized paleontologically in the Selma ehalk. There 

are, however, in the Chattahoochee region, a large number of wide-ranging species common to 

both the lower and upper divisions noted. 

Northeastward from Chattaho(')ehee River in Georgia the equivalents of Langdon's Ripley 

group pass first into a series of alternating marine and shallow-water beds, and finally, still farther to the northeast, into irregularly bedded sands and clays of shallow-water origin. The 

latter are overlapped and eoncealed in central and eastern Georgia by Eocene beds. 

The classification of the Georgia Cretaceous deposits adopted by Otto Veatch 842 in 1909, is 

essentially the same as that of Langdon, except that Veatch subdivided the Ripley into four 

parts on the basis of the alternati0n of beds of marine and shallow-water origin recognizable 

in a part of the area. These subdivisions are, in ascending order, the Blufftown marl, Cusseta 

sand, Renfroes marl, and Providence sand. 

The lower part of the "Blu:fftown marl" is probably synehronous with the Tombigbee sand 

member. The upper part of the "Blufftown marl," the Cusseta sand, the so-called Renfroes 

marl, and the Providence sand together are the equivalents of the Selma chalk where that 

formation is most fully developed in western Alabama and east-central Mississippi. 

As regards the correlation of the Upper Cretaceous deposits of the eastern Gulf region with 

deposits in regions outside of this area, the following may be said: That part of the series characterized by the presence of Exogyra costata Say, which includes the Ripley formation of northern 

Mississippi; about the upper half of the Selma chalk where most fully developed; and the upper 

one-half or two-thirds of the Ripley formation as developed in the Chattahoochee region are 

48011°--12----42 
658 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

correlated on the evidence of the invertebrates they contain, with the Peedee sand of the Carolinas 

and with the Monmouth formation of Maryland and New Jersey. 

The invertebrates present in that part of the Chattahoochee section lying below the beds 

characterized by the presence of Exogyra costata Say and above the top of the Eutaw formation 

indicate synchroneity with the upper marine invertebrate-bearing beds of the Black Creek 

formation of the Carolinas; the few species of plants found in the same beds offer no evidence 

in contradiction of this correlation. The invertebrates also point to synchroneity with all but 

the lowermost beds of the Matawan formation of Maryland and New Jersey. This portion 

of the Chattahoochee section is believed to correspond approximately to the lower one-half of 

the Selma chalk where the latter is most fully developed. No paleozoologic data have been 

obtained for a direct comparison of the Eutaw formation with the Black Creek formation; however, the invertebrate fauna present in the upper part of the Chattahoochee representatives of the 

Eutaw ("Blufftown marl") includes a considerable number of Black Creek species which do not 

range up into the beds carrying Exogyra costata Say. On account of this close faunal relationship 

it is believed that the Eutaw is represented inN orth Carolina by an undetermined portion of the 

Black Creek formation lying immediately beneath the invertebrate-bearing beds of that formation. There is evidence for considering the upper part of the Eutaw (Tombigbee sand member) 

as corresponding to the lowermost beds of the Matawan group (Merchantville clay) of New 

Jersey. 

Fossil plants have been collected from the Chattahoochee representatives of the Eutaw 

formation, and on the evidence thus furnished the beds have been correlated by E. W. Berry 

with the Black Creek formation of the Carolinas, no particular horizon in that formation, however, 

being designated, and with the Magothy formation of Maryland and New Jersey. The Tuscaloosa formation in Alabama has furnished an extensive flora which Berry considers in part contemporaneous with the Black Creek flora, in this case likewise the reference being made to no 

particular horizon in the Black Creek formation, and in part contemporaneous with the 

Magothy formation. 

In this connection it may be stated that in an unpublished manuscript on the Cretaceous flora of South Carolina Berry admits the possibility of the Magothy flora having persisted 

during the time of deposition of the Matawan equivalents in the Carolina and Chattahoochee 

regions. 

The question of the correlation of the eastern Gulf Upper Cretaceous with the Cretaceous 

of the western Gulf and western interior region is at the present time under investigatior. As 

regards the age relations of the beds toward the lower part of the series the two classes of biologic 

evidence, plant and animal, have led to certain differences of opinion between the students of each 

class. Until further facts have been obtained and a closer comparison of the species in the two 

regions has been made, it seems inadvisable to attempt a statement of exact correlation. As 

regards that portion of the eastern Gulf Cretaceous, however, characterized by the presence of 

Exogyra costata Say, there is general agreement that it corresponds approximately to theN avarro 

formation of 'Texas and to an undetermined upper portion of the Montana group of the western 

interior region. 

The Upper Cretaceous deposits present in South Carolina belong regionally with the deposits 

of the same age in North Carolina, the former being the southward continuation of the latter. 

The Carolina Upper Cretaceous is separated, geographically, from the corresponding Gulf Cretaceous deposits by a great overlap of Eocene strata. The two formational units recognizable 

in North Carolina, the Black Creek and Peedee formations, are also easily distinguishable in 

South Carolina. 

The Black Creek formation, the older of the divisions, received its name from Black Creek, 

South Carolina, along whose banks and valley sides it is best exposed in this State. 743a Better 

exposures occur, however, in the bluffs of Cape Fear River, in Bladen County, N.C. 

The deposits typical of the formation consist of an estimated thickness of 500 to 700 feet 

of irregularly bedded, laminated carbonaceous clays and thin laminre and lenses of sand, the 

whole being more or less lignitic and pyritiferous. The sand lenses and laminre are slightly 
UPPER CRETACEOUS. 659 

glauconitic in places throughout the formation, and toward the top occur rather massive interbedded layers of glauconitic sand some of which bear marine invertebrates. The clays carry 

fossil leaves in various stages of preservation. The sands and clays are believed to be in part 

of estuarine and in part of marine origin. An Upper Cretaceous terrane which has not been 

differentiated in "North Carolina but which is developed in South Carolina from Chesterfield 

County southwestward consists mainly of light-colored clays and coarse arkosic sands. These 

beds, designated the ~Iiddendorf beds by Sloan, 744b although lithologically different from the 

Black Creek, and evidently of shallower-water origin, are regarded by E. W. Berry, on the evidence of fossil plants, as contemporaneous with the lower portion of the Black Creek formation, 

and they are treated as a member of the Black Creek under the name .Middendorf arkose member. 

The Black Creek formation rests unconformably upon the Lower Cretaceous deposits of the 

region and is overlain by the Peedee sand. The typical beds of the Black Creek formation occur 

in the valley of Peedee River and its tributaries in parts of Marion, Florence, Marlboro, and 

Darlington counties, and the Middendorf arkose member appears in a relatively narrow area 

from Chesterfield County southwestward to Aiken County. The failure of the upper part of 

the Black Creek formation to appear at the surface to the south and the narrowing down of the 

Middendorf member in that direction are due to an overlap of Eocene beds from the southeast. 

Over much of the area of its occurrence the formation is concealed at the immediate surface by 

thin surficial deposits of late Tertiary or Pleistocene age. 

The Peedee sand received its name from Peedee River, South Carolina. 682 It was later designated by Sloan 743'

7440 the "Burches Ferry marl." The formation consists of 800 feet or more of 

marine sands and clays, more or less calcareous and glauconitic, carrying marine invertebrates. 

It appears at the surface in bluffs of Peedee River and its tributaries in Florence, vVilliamsburg, 

Georgetown, Marion, and Horry counties and is present in considerable areas in these counties 

beneath thin patches of Tertiary deposits and beneath a thin but almost continuous covering of 

Pleistocene and Recent deposits. Southward from this area the formation is overlapped and 

completely buried by Eocene strata. 

As previously stated, the Upper Cretaceous formations of this State constitute the southward continuation of deposits which have their most extensive areal distribution in North 

Carolina. More complete collections of fossil leaves and invertebrates have been made in that 

State than in South Carolina, and it is largely on the results of paleontologic investigation 

carried on in North Carolina that the following attempt at correlation with Cretaceous deposits 

in outside regions is based. The plants have been studied by E. W. Berry and the invertebrates 

by the writer. 

The invertebrates present in the upper part of the Black Creek formation indicate a prePeedee, or, in terms of the Maryland-New Jersey section, a pre-Monmouth age of the beds containing them. This part of the formation would appear, therefore, on this evidence to be 

synchronous with a part of the Matawan formation. The plants which occur throughout the 

vertical extent of the formation, being interbedded with the invertebrates in the upper part of 

the terrane, constitute a flora, according to Berry, analogous with that contained in the Magothy 

formation of Maryland and New Jersey, the Matawan formation in these States not having 

yielded any considerable flora. The Black Creek beds below the invertebrate-bearing beds of 

the formation are doubtless referable, therefore, in part or in whole to the Magothy formation, 

but the presence of the flora in supposed Matawan equivalents in the Carolinas would seem to 

indicate its persistence here to a later time than the record preserved in theN ew Jersey-Maryland 

deposits would indicate. 

Referred to the Upper Cretaceous deposits of the Chattahoochee region (Georgia-Alabama) 

the invertebrates in the upper beds of the Black Creek indicate close synchroneity with the 

beds exposed along Chattahoochee River from Roods Bend, in Stewart County, northward to 

the vicinity of Florence, in the same county, or to that part of the Ripley formation below the 

beds characterized by the presence of Exogyra costata Say. Fossil plants referable to the Black 

Creek flora have been found at several horizons from beds at the extreme base of the Upper 

Cretaceous deposits (Eutaw formation) of the region up almost to the base of the beds carrying 
660 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Exogyra cost'ata Say. The Black Creek would appear, therefore, to represent all the Upper 

Cretaceous deposits of the Chattahoochee region subjacent to the beds carrying the abovenamed species. This would mean the correspondence of the Black Creek to about the basal 

one-half of the Selma chalk, where that formation is most fully developed in western Alabama 

and east-central Mississippi, and to all of the Eutaw formation of the same region. According 

to Berry, on the evidence of the plants, the Black Creek includes also representatives of at least 

a part of the Tuscaloosa formation of Alabama, which forms the basal division of the Cretaceous 

in central and western Alabama and northeastern Mississippi. 

The Peedee sand is correlated, on the evidence furnished by invertebrates, with the Monmouth of the Maryland-New Jersey Cretaceous, with the beds of the eastern Gulf region carrying Exogyra costata Say (which would include the upper one-half or two-thirds of the Ripley 

formation of the Chattahoochee region, the upper half of the Selma chalk, and the Ripley 

formation of northern Mississippi), and with the Navarro formation of Texas. 

I--J 13. COLORADO AND NEW MEXICO. 

Concerning the Cretaceous of southwestern Colorado, Cross 187 states: 

The lowest Cretaceous formation recognized is the Dakota, which alone, of all the divisions, 

has the lithologic character common in other parts of the Rocky Mountain region. 

Succeeding the Dakota comes a very homogeneous clay shale formation more than 1,000 

feet thick, which from the invertebrate fossils found at several horizons must be supposed to 

represent the Benton, Niobrara, and a part of the Pierre formations as distinguished at the 

eastern base of the Front Range in Colorado. But the fossil-bearing strata are neither sufficiently numerous nor well enough developed to serve as horizons for a satisfactory subdivision 

of this shale formation, which was named the Mancos shale in the Telluride folio. 

The next higher distinguishable series in the Cretaceous section is the variable complex 

whose more massive sandstones cause the principal scarps of the Mesa Verde. Holmes named 

this series after the Mesa Verde in the Hayden reports and his designation is here accepted. 

It was not used, however, on the Hayden map. The Mesaverde formation consists of alternating sandstones and shales with several seams of excellent coal. The invertebrate fossils, 

which are not uncommon at several horizons in the shales and sandstones, range throughout 

the Montana group, and hence give no ground for a reference of the Mesaverde strata to the 

Fox Hills, as was done on the Hayden map. · 

Above the Mesaverde formation occurs another formation of clay shale, reaching an 

observed thickness of nearly 2,000 feet, which is very much like the Mancos shale but contains fewer fossils. The only identifiable form thus far found in this shale occurs also in the 

Mancos shale, so that this division is still apparently below the true Fox Hills. This formation 

is called the Lewis shale. Holmes designated it the "Sand Shale group." 

Still above the Lewis shale is a second series of sandstones, shales, and coals, bearing some 

resemblance to the Mesaverde formation but differing in detail. The lowest member of this 

complex is the "Pictured Cliff sandstone" of Holmes's San Juan section, which he placed in the 

Fox Hills upon the evidence of invertebrate remains. The remainder was referred by Holmes 

to the Laramie, but without fossil evidence. The present survey has also failed to bring to 

light valid ground for assigning any of the beds in question to the Laramie, while there is some 

reason to believe that more than the lower sandstone belongs to the Montana group. 

Between the uppermost quartzose sandstones of the Cretaceous and the Puerco marls 

(Eocene), which are well developed below Durango on the Animas, there occurs a series of 

beds not recognized by Holmes. These strata are composed mainly of andesitic debris, tuffs, 

or conglomerates, and it has been proposed by the writer to call them the Animas beds or 

formation. The fossil plants obtained from the tuff layers clearly indicated that the beds may 

be correlated with the Denver, Middle Park, Livingston, and other post-Laramie formations, 

which paleontologists refer to the Mesozoic, although they are stratigraphically shown to be 

later than the great revolution which terminated the conformable succession of Cretaceous 

sediments. 
UPPER CRETACEOUS. 661 

The strata thus described by Cross extend southward in New Mexico around 

the east side of the San Juan basin, where they have been traced by Gardner: 358 

The San Juan coal region is a basin of more or less circular outline, with an area of about 

13,500 square miles, about one-seventh of which lies in Colorado and the remainder in New 

Mexico. The region receives its name from San Juan River. The two chief coal-producing 

localities are Durango, in the extreme southwestern part of Colorado, on the Denver & Rio 

Grande Railroad, and Gallup, in New Mexico, on the Atchison, Topeka & Santa Fe Railway. 

The formations known to occur in the San Juan district are as follows: 

Generalized section of rocks in coal field between Gallina and Raton Spring, N. Mex. 

------------c-----~---~~---------------,------ ----

System. Series or formation. 

Quaternary................. . . . . Recent._ ... _....... . . . _ .................. . 

ij'~~~~f~r:i~~tion.-------.----- - ---- -------- --- -- -

Tertiary.. . . . . . . . . . . . . . . . . . . . . . ~~~~~f~r~i~a(~)~- .......... _ _ _ .................... . 

Puerco formation ..... _ ....... __ . _. _ ..... _ ......... _______ . _. _ 

_ Unconformity. 

I Laramie formation ..... _ . _ . _ . _ . _ ... _ . _ ... _ . _ ..... ___ . _____ ..... _ .. 

Lewis shale .... __ ............. _ . _ ................................. . Cretaceous ... _ .... _.............. Mesaverde formation .......... __ ._ . _ ............. . Mancos shale._ ................................................... . Dakota sandstone. 

Thickness 

(feet). 

1}-50 

(?) 1,000 

110 

690 

900 

250-2,000 

200- 900 

500-1,000 

-----------------'-------------------------~-'------

The Dakota or basal formation of the Cretaceous throughout the San Juan region * * * 

consists chiefly of hard quartzite with intercalated shale toward the top but near the base is 

made up of reddish sandstone and yellowish shale that grade gradually into the Jurassic-Triassic 

rocks below. No signs of coal beds were observed in the Dakota, but they are known to occur 

in other parts of the basin. 

'Ihe Mancos shale rests conformably upon the Dakota. In the type-locality at Mancos, 

Colo., the formation is all shale, but in New Mexico there are transitional sandy beds toward the 

top. At a point 10 miles north of Gallina a part of the formation becomes arenaceous and 

forms a hogback in the shale valley. This sandy bed is about 30 feet thiGk and about 275 

feet below the top of the formation. It is no doubt the beginning of the sandstone and shale 

formation that increases in thickness toward the south and is coal bearing on the south side 

of the basin. In the vicinity of San Miguel, 12 miles down Rio Puerco from Cuba, the writer 

observed a thickness of 300 feet of argillaceous sandstone and sandy shale in the Mancos, 

grading upward through a transition zone to the Mesaverde. 

The ~fesaverde is the most important coal-bearing formation in the area, as well as throughout the San Juan region. It forms a prominent hogback across the east side of the GallinaRaton Spring field. * * * Coal beds occur at varying intervals between a prominent basal 

and a capping sandstone. The main coal bed of the area is just below the top sandstone. 

'Ihe Lewis is much like the Manc0s in appearance. It changes notably in thickness across 

the field. From about 2,000 feet north of Gallina it thins to 250 feet on the Arroyo Torrejon 

and in the vicinity of Raton Spring. It may be, however, that the lower part of the shale in 

that region is replaced by sanclsto~e which has heretofore been considered Mesaverde. 

The Laramie is without workable coal beds at the north limit of the field. In fact, Schrader a 

maps the entire area northward to the Colorado State line as barren. West of Gallina the Laramie and underlying Lewis shale disappear beneath unconformable Eocene beds. The next 

a Schrader, F. C., The Durango-Gallup coal field, Colorado and New Mexico: Bull. U. S. Geol. Survey No. 285, 

1906, p. 243. 
'662 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

point to the south at which the Laramie shows is where it emerges from beneath the Puerco, 

about 10~ miles southwest of Cuba. The Laramie strata exposed between this point and 

Raton Spring are coal bearing, the coal beds increasing in thickness and number toward the west. 

The section given by Gardner applies in a general way to the region originally 

described by Holmes in the valley of San Juan River and may be compared with 

that observed by Dutton in the Zuni Plateau farther south. Sections by both 

Holmes and Dutton are given in the latter's report. 301c 

South of Santa Fe, N. Mex., Lee a observed the following section. The lower 

555 feet of the section was measured about 2 miles north of Galisteo Canyon; the 

upper part about 1 ~ miles south of Galisteo. 

Age. 

(?) 

Section of rocks exposed in Galisteo Canyon, south of Santa Fe, N. ~lfex. 

Formation. I Character. 

Galisteo Sandstone, conglomeratic, red, containing petrified trunks of palm wood and ~andstone. trees of deciduous varif'ties. 

Sandstone and shale, coal bearing (Madrid group of Johnson) ............... . Sandstone with layers of black shale ...... _._ ................... _._ ..... _._ Rand8tone, brown, massive, cliff-making ...... _ .......... _ ................ . Montana. Shale, dark colored, with limestone concretions containing Benton fossils near the base; calcareous layers with Niobrara fossils a little higher; and 

limestone concretions containing Pierre fossils near the middle and at the 

top ............. -- ..... ----- ..... ------ ..... --·--------------- .. ------ --~~--1 Limestone in thin plates alternating with black shale (probably Greenhorn limestone) ................ _ ..................................... . Upper Cre- Shale, black, with sandy layers near the base .............................. . taceous. Sandstone, brown, in thin layers, alternating with black shale and characterColorado. ized by numerous worm borings ................................. _ ..... . Sandstone, massive, buff colored, irregular texture ......................... . 

Dakota 

sandstone. 

Shale, black, with concretions of impure limestone that weathers yellow ... . 

Sandstone, white, conglomeratic at the base .. ___ ... __ . ____ ... _______ .. Rhale, blue. ____ ....... ___ ....... _ .. _ .. _______ . __________ . _________ _ 

Sandstone, white, friable, coarse grained, cross-bedded ..... _._ .. _ .... __ 

--- .. ------ -j~~~--j-~-~- ~--~-~~~-~--

Jurassic or Morrison 

Cretaceous. formation. 

--~-j-~--

Carboniferous (Pf!nnsylvanian). 

Rhale and sandstone, variegated_ .... 

Sa~dstone and shale with beds of gypsum, red. 

Thickness 

(feet). 

460± 

200± 

50-100 

2,000 

20 

110 

15 

10 

70 

40 

10 

70 

210 

The Cretaceous of the western Great Plains near the southern boundary of 

Colorado is described by Hills, 150• 

451 from whose account the following notes are 

derived. 

The lowest Upper Cretaceous in the Elmoro quadrangle is the Dakota sandstone, the base of which is not there exposed. On Purgatoire River, farther east. 

it rests upon the Comanche series and, as described by Stanton/81a is a gray and 

brown, mostly massive cross-bedded sandstone about 100 feet thick. On the same 

stream in the Elmoro quadrangle Hills measured 300 feet and estimated the total 

a Lee, W. T., unpublished notes. 
UPPER CRETACEOUS. 663 

at 375 feet, but it is probable that he included in the Dakota some Comanche strata 

which had not at that time been recognized in the region. Hills says :

450 

The lower two-thirds of the Dakota consists of sandstones, with fine conglomerates, 

imperfectly stratified or cross-bedded, and the heavy layers which make up this part of the 

formation are separated from one another by thin bands of finer, shaly material. The upper 

one-third also consists of sandstone layers parted from· one another by thin bands of shale, 

but the individual beds are not so thick and the shale partings are more numerous. These two 

portions are separated from each other by a prominent bed of hard shale-fire clay-the position 

of which, in cliff exposures, is often indicated by a narrow shelf or terrace immediately below it. 

The color of the upper sandstone is generally grayish white, the lower somewhat darker, 

with yellowish and brownish weathered surfaces. The pebbles of the coarser layers are quartzite, quartz, and chert. The finer-grained layers are made up of quartz grains, among which 

white, kaolin-like specks are induded. The lower sandstone is of an open, porous texture and 

more loosely aggregated than that lying above the fire-clay stratum. But the texture of any 

particular layer varies from place to place, and the same is true of the thickness of the individual beds, so that the only constant features are the fine-grained, compact sandstone above 

and the coarser, porous sandstone below the persistent bed of fire clay separating them. 

The Dakota is followed in succession by the Graneros shale, the Greenhorn 

limestone, and the Carlile shale, which constitute the Benton group. Of these formations Hills says: 

The Graneros formation, which marks the beginning of the marine conditions following 

the subsidence that terminated the Dakota epoch, consists of dark-gray clay shale, from 200 

to 210 feet in thickness, darker near the eenter than elsewhere, resting on the Dakota sandstone 

and graduating rather abruptly into it. Large limestone eoneretions are not uncommon in the 

upper half but are not a distinguishing feature, as similar eoncretions are met with in the other 

shale formations of the district. At a distance of about 30 feet above the base there is a layer, 

from 1 to 2 feet thiek, of hard concretionary limestone, weathering an orange tint, whieh is 

noticeable and eharacteristic. 

The Greenhorn formation is made up of layers of dove-colored limestone, usually less than 

12 inches thiek, separated from one another by somewhat thicker lay.ers of shaly material. It 

graduates into the Graneros shale below and the Carlile shale above. Fossil shells are abundant 

in the-limestone layers, especially the flat, oval, eoncentrieally ridged Inoceramus labiatus. 

The coiled ammonite Prionocyclus is sometimes present. The thickness varies from place to 

place, owing to the thickening 6r thinning of the shaly layers. At the same time the graduation into the Graneros and Carlile formations is more abrupt in some places than in others, thus 

rendering it doubtful at times where to draw the line. The maximum thickness occurs in the 

northeastern part of the quadrangle, where it is often 50 feet. In the southeastern part the 

exposed sections are not so eomplete and it is thought that in some places the thickness may 

not exceed 30 feet. * * * 

The Carlile formation consists of about 180 feet of dark-gray shale, the middle portion the 

darkest, overlain by from 10 to 15 feet of soft, shaly yellowish-gray sandstone, into which it 

graduates through a varying thickness of more distinctively shaly material. A thin band of 

purplish bituminous limestone containing large numbers of coiled ammonites is persistently 

present capping the formation. Concretionary nodules several feet in diameter and seamed 

with lime spar are rather common, especially in the upper half of the beds. 

Overlying the Benton group is the Niobrara group, concerning which Hills 

says :45Ja 

The Timpas and Apishapa formations, both of which are characterized by the presence of 

limestone strata, or of shale containing a considerable proportion of lime, constitute a Niobrara 
664 INDEX TO THE STRA'l'IGl~APHY OF NORTH AMERICA. 

group-and are elsewhere mapped undivided as the Niobrara formation. The Niobrara beds are 

distinguishable by their limy character from all other Cretaceous formations, except the Greenhorn limestone of the Benton group, from which, however, the limestone of the former is readily 

distinguished by its color and fracture. 

The Timpas formation comprises about 200 feet of strata, of which the lower 45 to 50 feet 

is limestone and the remaining 150 feet calcareo-argillaceous shale interrupted by thin limestone 

bands, which become prominent toward the top. The limestone at the base is made up of 

layers, usually less than 12 inches thick, which are separated from one another by very much 

thinner layers of calcareous shale. The fracture is conchoidal and rudely parallel with the 

bedding planes, and the grayish-white weathered surfaces break off naturally into thin conchoidal 

flakes. As the Greenhorn limestone is dove colored and has a cross fracture, the two are easily 

distinguished. The only fossil at all noticeable is the large oval, concentrically ridged shell 

Inoceramus deformis, characterized by the excessive bulge of the ventral valve. The limestone 

itself, however, consists largely of the skeletons of foraminiferal organisms, readily seen in thin, 

transparent sections under the microscope. The middle and upper portions of the formation 

consist mainly of bluish or dove-colored shale, with thin bands of limestone at intervals. There 

are three of these bands from 1 to 3 feet thick in the upper 40 feet of the section, and one of these 

marks the top of the formation. * * * 

The total thickness of the Apishapa approaches 500 feet. The lower portion for about 

40 feet consists of dark-gray or blue-gray shales, followed by rotten shales of paper-like lamination about 90 feet thick, which grade through blue sandy shale into calcareo-arenaceous shales. 

The latter become coarser and flaglike toward the middle of the formation and constitute 

about one-third of it. The upper 100 feet resembles the basal portion, but includes two and 

at times three thin layers of limestone and usually lens-shaped concretions of similar but more 

impure material. The middle zone is always more or less bituminous and fairly constant in 

character. The remainder of the formation varies considerably except in its general shaly 

features and the presence of limestone strata near the top. The fossil remains consist of fish 

scales, which are generally abundant in the shales and sometimes in the coarser flaglike layers. 

In the sandy shales at the base of the middle zone the tracks of what was probably a small 

crustacean are characteristic. These tracks appear as a double row of short, straight lines, 

those on one side inclined toward those on the other. 

The Pierre shale succeeds the Apishapa formation of the Niobrara group, and 

of it Hills says: 

The beds of the Pierre epoch consist of argillaceous shales throughout. The thickness is 

estimated at from 1,300 feet at the southeast extremity of the outcrop to 1,500 feet at the northwest extremity, the changing dip and small number of exposures making accurate measurement 

very difficult, if not impossible. The shales vary much in appearance. The basal and upper 

zones weather to a yellowish-green color; the middle zone is dark gray to lead-gray, occasionally 

almost black. The latter zone contains an abundance of lime-iron concretions that break 

up readily and impart a rusty tint to the surface. They are always arranged parallel with the 

bedding. 

The Trinidad sandstone follows the Pierre shale. According to Hills it representssome part or possibly the whole of the Fox Hills group, but on account of its relation to 

the Laramie and the thickening of the lower zone of the formation northward it is presumably 

the upper portion only. In the Spanish Peaks quadrangle the total thickness is about 150 feet 

in the vicinity of Trinidad and 170 feet toward the north boundary. As elsewhere the formation consists of a basal zone of thin-bedded, fine-grained dark-gray sandstone layers, separated 

from one another by thinner partings of shale; and an upper zone of massive light-gray sandstone, 

capped by a few feet of brown sandstone in contact with the overlying Laramie. * * * 

The marine Cretaceous ended with the Trinidad. The conditions of the succeeding Laramie 

epoch were shallow waters connected with the ocean. * * * 
UPPER CRETACEOUS. 665 

Owing partly to a certain amount of erosion preceding the deposition of the succeeding 

Eocene formation, though mostly to the general thinning out of the measures toward the north, 

the thickness of the Laramie varies considerably. Thus, along the southwestern border of the 

district and in the Raton Mountains near the southern border it is not less than 2,000 feet, 

and doubtless exceeds this amount near the crest of the high ridge immediately south of the 

line; while in the central and northern portions it does not exceed 1, 700 feet, and is even less 

than this in the northeastern area near the north boundary, where it is about 1,500 feet. 

The sections of the Laramie in different parts of the district vary but little in their general 

features. There is always an alternation of massive or thick-bedded gray sandstone beds with 

thick shaly beds. The latter predominate toward the base of the group, the former toward the 

top. The shaly beds of the upper half of the group are shale or clay shale, but in the lower 

half, noticeably in the lower portion of it, they consist of sand shale-that is, thin layers of 

greenish-gray fine-grained sandstone with partings of shale of the same color. The lower shaly 

beds are occasionally interrupted by bands of sandstone a few feet in thickness and by beds 

of clay shale associated with seams of coal, which may occur toward the center of the shale bed 

or entirely above it and may equal the latter in thickness. Some of the upper sandstone beds 

are disposed to weather into cavernous forms, and some of the alternating beds associated with 

them consist of fine-grained greenish-gray fissile sandstone instead of shale. But aside from 

the general features the sections possess little in common. It is only the lower, main sandstone 

bed and the shaly beds above and below it that are really persistent throughout the 

distri:lt. * * * 

The group is characterized by a rich semitropical flora, very similar to what is found in the 

Gulf States to-day, and leaf imprints of certain species of oak, fan palm, fig, poplar, willow, and 

tulip tree are of common occurrence in the thin-bedded sandstone and lower shaly beds. 

Lee's recent work in southern Colorado and northern New Mexico 529 throws 

doubt on the Laramie age of the coal-bearing rocks of this region, or at least of the 

upper part of them. 

The Cretaceous of the Denver district was described in great detail by Eldridge322 in the Denver monograph. The original description should be consulted. 

Fenneman 328a has published a report on the Boulder quadrangle, which lies partly 

in the Denver Basin, and his descriptions are here abstracted as follows: 

Above the Jurassic [Morrison] comes the prominent Dakota formation, easily recognized 

and well known in the great hogback which parallels the Front Range for hundreds of miles. 

It is a firm sandstone that is often quartzite, is generally thick bedded, and is characterized by 

frequent cross-bedding and ripple marks. * * * At its base, though not everywhere present, 

is a pebble conglomerate. The constituent pebbles include ''abundant limestones, quartzites, 

clays, flints, jaspers, and rocks of granitic composition, together with the separate mineral constituents of the last." The whole is so firmly cemented that, where unweathered, the rock 

fractures in broad planes which pass through the pebbles. Frequently a series of thin pebble 

beds in a mass of sandstone takes the place of the continuous conglomerate. This alternation 

of beds makes the thickness of the basal zone indefinite, but there are few pebble beds above the 

first 20 or 30 feet. Considerable variation may be discerned in the sandstone, but with the 

exception of the basal conglomerate no one bed has a constant position in the column. Generally the sandstone is composed of quartz grains, with a siliceous cement, and is gray or yellowish gtay. With increase of iron oxide the sandstone exhibits striking features of differential 

coloring. * * * At intervals between the stronger ridge-making ledges occur layers of thinly 

laminated shaly sands, aggregating in. thickness only a few feet. * * * The line between the 

Dakota and the overlying Benton shales, while very distinct in a large way, is not so easily 

located in detail. Alternations of sandstone and shale occur over a zone of 50 feet or more. 

The thickness of the Dakota at Bear Canyon is about 320 feet, and at Fourmile Canyon a little 

greater. 
666 INDEX TO THE STRATIGRAPHY OF NORTH M1ERICA. 

The Benton shales have a thickness of more than 500 feet at the north end of the field. 

They are somewhat thinner at the south end and taper uniformly from both ends toward Boulder 

Creek, where the formation almost disappears. The great body of the shale is dark. There are 

frequent layers a few inches thick which are strongly impregnated with iron. The formation is 

calcareous in varying degree. At many places some beds are composed of a black limestone 

showing a crystalline surface when broken and having a strong bituminous odor. * * * As 

the summit is approached the blackness disappears and the last 75 feet (observed near the north 

end of the field) show light-colored limestone, shale, and sandstone. North of Sixmile Canyon 

these beds, which may be regarded as transitional to the Niobrara, show the following section: 

Section of upper part of Benton formation north of Sixmile Canyon. 

Greenish sandstone, calcareous in upper third ................. . 

Shales, blue to yellow, non calcareous .............. . 

Sandstone, noncalcareous, firm, rather purplish ...... . 

Shale, iron stained at intervals ...................... . 

Shale, calcareous (or calcareous at top). 

Feet. 

15 

---- 15 

10 

10 

Below these beds is a limestone of variable thickness strongly resembling the basal Niobrara. 

It occurs in lenses only. The greenish sandstone at the top is found below the basal Niobrara 

wherever the latter is exposed in this district. It is generally 10 or 15 feet thick and is not 

calcareous except in the upper portion. As it is often very much fractured and the cracks 

are abundantly filled with carbonate of lime, this calcareous character may be due to infiltration 

from the limestone above. The blue and yellow shales below are also seen wherever the base 

of the greenish sandstone is exposed. 

The Benton is succeeded by the ~iobrara, whose prominent characteristic is its calcareous 

nature. It is composed in small part of true limestones, but the greater mass is made up of 

calcareous shales, while considerable portions are of intermediate character. Its thickness at 

Fourmile Canyon is a little more than 400 feet. The basal stratum of compact limestone rests 

upon the greenish sandstone which is at the top of the Benton. Occasionally a foot or more 

of light-colored marl intervenes. Below the Niobrara, as pointed out above, are occasional 

beds of similar limestone and calcareous shales interbedded with noncalcareous sandstones. 

Above the Niobrara are the Pierre shales, which are more than 5,000 feet thick. They are 

slate colored, leaden gray, dark brown, and sometimes nearly black. * * * While in general 

noncalcareous, the Pierre has local limy beds. At places these form continuous strata, as, for 

example, 4 miles north of Boulder, one-half mile east of the contact with the ~iobrara. Here, 

for a thickness of nearly 40 feet, strong limestone beds are so closely grouped as to give the 

outcrop the appearance of the basal Niobrara. At other places the limestone beds are smaller 

and more isolated or are divided into concretionary masses often containing fossils. Less 

prominent calcareous masses may be found at any horizon, either in beds or in more or less 

perfect concretions. Concentrations of iron occur in similar but less massive forms, ranging 

from clear-cut beds to well-formed nodules. The lime and the iron may or may not occur in 

the same concretionary mass. Many of the calcareous nodules mentioned contain much iron 

carbonate, which, in progressive oxidation toward the center, gives rise to sharply marked 

concentric shells differing in color. Sandy beds may occur at any place in the section. The 

most prominent and persistent of these is about one-third way up from the base, or a little 

higher. * * * From pure sands at one extreme to pure clay shales at the other, the Pierre 

shows all gradations in composition. The sandy layers are generally firm and gritty, almost as 

dark colored as the shales themselves, and not very porous. In rare instances light-colored, 

friable sands are encountered in drilling oil wells. The thickness of the sandy beds is as variable 

as their constitution, while the lateral extent of such beds, as indicated by occasional outcrops 

and by the records of wells, is, in a large majority of cases, a small fraction of a mile. Some of 

these beds may be lenses, but doubtless the more common mode of lateral limitation of the 

sands is by a gradual change in composition of the beds into the shales. 
UPPER CRETACEOUS. 667 

Within the limits of this area the great body of the Fox Hills is but indefinitely distinguished 

from the Pierre. In mild contrast with the latter its shales are yellowish instead of slate colored 

and are also more arenaceous. * * * The topmost stratum of the Fox Hills is, however, 

a very definite feature in the stratigraphy. For many feet below it there are occasional sandstone beds, and the intervening shales arc highly sandy, but at the top is a continuous bed of 

sandstone 40 feet thick. 

The Laramie outcrops in the southeast corner of the area. Within the limits here defined 

this formati'on consists essentially of (1) sandstones at the base, (2) sandstones alternating with 

shales and coal overlying, (3) sandstones above the coal, and (4) clays, containing isolated sandstone beds and lignitic streaks. * * * The basal sandstones are exposed at various places 

in the Marshall coal field, but best of all at White Rocks, on the eastern border of the area 

mapped. Here the bold sandstone escarpment comprises two distinct and massive beds, 

whose topographic effect, however, is that of a single stratum continuous with the Fox Hills 

sandstone beneath. The lower Laramie sandstone is 40 feet thick, equaling the underlying 

Fox Hills sandstone, while between the two are a few feet of thinly laminated sandstones, varying 

to a lignitic shale. The second and thicker stratum of Laramie is separated from the first by 

gray shaly sands, inclosing 10 inches of lignitic shale and above 10 inches of coal. Both Laramie 

beds are clearly distinguished from the Fox Hills by their gray or white color and coarser grain. 

They are composed of coarse quartz sand and in addition alw~ys show some black specks of an 

undetermined mineral. The two sandstones differ in the following respects: The upper is 

distinctly whiter and, where exposed along bedding planes (and to a less degree on fracture 

planes), the surface is marked by weathered-out cracks, making polygonal patterns a few feet 

across. Both strata are weakly cemented and noncalcareous but contain giant concretions 

which are very calcareous, hard, and, on weathered surfaces, are stained brown with iron oxide. 

The 7 5 feet of thinner-bedded sandstones above, containing some shale and coal, are best seen 

at Marshall. The shales occur at frequent intervals and are often lignitic. The one workable 

coal seam is sometimes at the top of this division but again is overlain by 5 or 10 feet of shales 

and thin sands; all, however, lie below the more persistent sandstone referred to under (3) above. 

Aside from the coal seam, no horizon above the basal sandstones is more definite than the 

Ostrea glabra zone, which occurs 15 or 20 feet from the base of the series. The sandstone above 

the coal is not unlike the se{{ond massive bed above the bottom. It weathers into the same angular patterns and has the same appearance in the hand spQcimen. Its thickness is from 8 to 15 

feet. The overlying clays, as shown in this area, are yellow and purple, and have frequent 

lignitic bands but no coal, at least within the limits of the area covered by the map. 

I-K 10. CALIFORNIA AND SOUTHERN OREGON. 

The Upper Cretaceous (Chico formation) of California has long been known. 

It was described by Diller and Stanton 2840 as part of the "Shasta-Chico series." 

(See J-K 10, Chapter XIV, p. 615.) Anderson 27 discussed its general relations. 

Stanton 782a has recently stated the following regarding the fauna: 

On the Pacific coast the Horsetown fauna is succeeded by tho littoral Chico fauna, which is 

distributed from the Yukon River to Lower California, occurring on the lower Yukon, tho 

Alaska Peninsula, Queen Charlotte and Vancouver islands, in middle and southern Oregon, 

in the Sacramento Valley and the Coast Ranges of California to San Diego, and on the peninsula 

of Lower California as far south as latitude 31° 30'. There are considerable local variations 

in this fauna, as would be expected in view of its great range in latitude. The assemblage of 

forms found on the Yukon is quite different from that occurring in the Sacramento Valley, and 

still another facies is found in southern California, but these are all connected by common 

species, so that there is no hesitation about referring both the northern and the southern facies 

to the Chico fauna. The fauna as a whole, like the later Horsetown fauna, is Indo-Pacific 

in its affinities and is strikingly different from the faunas of the Atlantic border and interior 

regions of North A::.nerica. Whiteaves and F. M. Anderson have argued for a connection during 

Chico time between the Pacific and interior seas, but the evidence brought forward in support 
668 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

of this view is based on types that have a world-wide distribution and on those that are only 

similar, not specifically identical. In my opinion direct connection has not been proved. In 

time range the Chico formation apparently began somewhat earlier and continued somewhat later 

than the Colorado fauna of the interior seas, but it did not extend to the end of the Cretaceous, 

and latest Cretaceous time is probably not represented by marine deposits on the Pacific coast. 

The character and relations of the Chico vary in different localities from southern California northward through the Coast Range and the northern Sacramento 

Valley. The Chico in the San Luis quadrangle is described by Fairbanks 325 as 

follows: 

The Atascadero formation, the local representative of the Chico group, consists mainly 

of certain soft sandstones of a grayish-yellow color. The formation derives its name from 

Atascadero Creek. A few poorly preserved fossils were found in it at several points along the 

northern slope of the Santa Lucia Range. 

* * * * * * * * * Near the coast the Atascadero formation occurs above the San Luis (pre-Cretaceous} 

formation, but northeast of the Santa Lucia Range it rests on the Toro (lower Cretaceous). 

In the latter region the Atascadero terminates downward in a conglomerate which is in places 

100 feet thick and contains large granite bowlders. The striking contrast in general lithologic 

character between the Atascadero and Toro formations is indicative of a marked change in 

conditions of deposition. The hypothesis that there is a hiatus in the Cretaceous sediments is 

well founded. It is based, on the one hand, on the fact that the Atascadero sediments extend 

over the Toro across both strike and dip, indicating that the Toro had been upturned and planed 

off before the Atascadero began to be deposited (as may be seen at many points, particularly 

on the divide between Atascadero and Santa Margarita creeks), and, on the other hand, on the 

fact that the Atascadero in the same locality rests indiscriminately upon the Toro and San 

Luis formations. 

Another interesting fact should be mentioned in connection with the discussion of an unconformity. The serpentine here, as in other portions of the Coast Ranges, wherever it comes in 

contact with the lower Cretaceous is intrusive, while it P-as nowhere been observed to penetrate 

the Atascadero formation. There were at least two epochs of igneous activity during the 

Cretaceous, and three if the formation of the San Luis Buttes be included; this supports the 

view that marked movements occurred during Cretaceous time. 

The Chico is developed on the east side of the Coast Range in the mountains 

bordering the San Joaquin Valley, according to Arnold and Anderson. 34b A quotation from their paper has been given in Chapter XIV (pp. 616-617), outlining the 

general sequence of the Cretaceous beds in the Coalinga district. The rocks are 

there separable into three divisions, of which the lowest is supposedly of Knoxville 

(Lower Cretaceous) age, and the middle and uppermost contain Chico (Upper 

Cretaceous) fossils. The Chico portion is described as follows: 

The middle one of the main divisions into which the Knoxville-Chico rocks are divisible upon 

lithologic grounds comprises a thick series of alternating thin beds of dark shale and sandstone 

with the above-mentioned heavy conglomerate at its base and with the characteristic massive, 

concretionary sandstone beds that form the upper division overlying. Its thickness, including 

the conglomerate zone, measures at least 4,800 feet. * * * The conglomerate is locally 

extremely variable and is not continuous. It ·may in places be traced directly into massive 

sandstone or even into thinly bedded sandstone and shale, as along Alcalde Canyon between 

2 and 3 miles west of Alcalde. It represents throughout the district, however, an important 

stratigraphic horizon characterized by a coarsening of the sediments. * * * 

The uppermost of the three divisions of the Knoxville-Chico is predominantly concretionary sandstone in the lower part and shale in the upper part and has a thickness of at least 

4,700 feet. * * * Taken as a whole the upper division is strikingly distinct from other 
UPPER CRETACEOUS. 669 

formations in the district and seems to represent a separate stratigraphic unit, although no 

unconformity has been made out at its base. 

The lower half of the upper division consists chiefly of massive sandstone beds, often weathering cavernous. * * * The sandstone is usually drab, medium grained, and not very hard. 

Above the succession of concretionary sandstone beds, and forming the upper half of the 

upper division of the Knoxville-Chico, comes a less prominent and less uniform succession of 

beds in which shale is predominant. * * * This upper half of the upper division consists 

of two main members predominantly of shale, each approximating 1,000 feet thick, separated by 

a much thinner but more prominent member of concretionary sandstone, in general similar to 

that lower down. * * * The lower of the two shale members has few exposures but is 

notable for the presence in it of different kinds of deposits, such as blackish, thiruy bedded 

clay shale and yellowish and whitish calcareous and arenaceous shale and sand, and for the 

presence of ammonites, baculites, Inoceramus, and other fossils, which weather out in a fragmentary state on the surface of the clayey soil. * * * The sandstone separating the two 

shale members varies from 200 to 300 or 400 feet in thickness and consists of yellowish-gray and 

brown sandstone full of large brown concretions. It is of the same type as the characteristic 

Chico concretionary sandstone farther down in the section. * * * The uppermost member 

is one of particular interest owing to its individuality among the known types of Cretaceous 

deposits, its large content of organic material, its petroliferous nature, and its similarity to the 

Eocene beds. It is at least 1,200 feet thick and consists principally of shale but has a considerable admixture of sand and sandstone. For convenience it will be referred to as a whole as 

the purple shale member. The most characteristic beds of this zone are of purplish-brown, fairly 

hard, thinly bedded, both siliceous and calcareous clay shale, in which the tests of Foraminifera 

are very abundant. This shale bears a resemblance to some of the less siliceous shale in the 

upper part of the overlying Tejon (Eocene), especially to that shale as it occurs in the southern 

part of this district, and is not unlike some argillaceO'IS phases of the Monterey shale (middle 

:Miocene) of the outer Coast Ranges and. the shale mapped as Santa Margarita (?) (middle 

Miocene) along Reef Ridge and at other points in this district. * * * 

Above the purple shale of the uppermost Cretaceous lie dark clay and clay shale beds 

aggregating several hundred feet in thickness, which appear to form an upward continuation of 

the shale of the Chico but which are mapped with the Tejon (Eocene). Fossils recently found 

near the northern edge of the Coalinga district show that the higher of these beds belong with the 

sandstone of the Tejon above, but there is reason to believe that 200 feet or so of beds at the 

base belong in the Chico. * * * ·whether the line of separation between the Cretaceous 

and Tertiary occurs at the top of the purple shale or somewhat higher, within the darker clay 

shale, it is noteworthy that it should occur within a zone of fine sediments and be marked by no 

break of evident stratigraphic importance. However, in spite of the apparent transition between 

the shale of the Cretaceous and that of the Eocene in the northern part of the Coalinga district, 

it is believed that they are separated by an unconformity. The evidence of this is the progressive 

disappearance of the upper members of the Knoxville-Chico southward in the district, whereas 

the basal Tejon is believed to represent a fairly constant horizon. * * * This thinning 

and disappearance of the members is probably the effect of erosion upon them before the 

deposition of the Eocene. 

For a general correlation of the Mesozoic and Cenozoic formations of the Coast 

Range, see Chapter XVII (p. 818). 

In the Santa Cruz quadrangle the Chico is very thick. Branner 97 a states: 

The Chico strata along the coast are made up for the most part of hard siliceous shale, sand-. 

stone, imd massive, coarse conglomerate. The general dip of the beds, for a distance of 3 miles 

along the coast south of the mouth of Pescadero Creek, is toward the southwest and the section 

apparently exposes about 9,400 feet of strata. These strata dip at high angles, however, and 

may be repeated by folds, or to some extent by faults, thereby making the thickness appear greater 

than it is. This is the case 2 miles north of Pigeon Point, where massive conglomerate is faulted 

into contact with sandstone and shale. 
670 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The upper portion of the formation is characterized by massive, coarse conglomerate with 

interbedded sandstone. The conglomerate shows evidences of much crushing, faulted and 

crushed pebbles being plentiful in it. a 

The Chico of the northern portion of the valley of California was described by 

Diller and Stanton. 284b A recent account by Diller 279a is contained in the Redding 

folio. He says in part that the Chico formation is composed chiefly of yellowish 

sandstone which is in places pebbly and which, though conglomeratic toward the 

base, passes upward into gray shales. It extends throughout the Sacramento Valley 

and is covered by later formations except around the valley borders. Northeastward it extends through Lassen Strait between the Klamath :Mountains and the 

Sierra and possibly connects with the Chico of northern California and Oregon. The 

greatest thickness observed in the Redding quadrangle is about 500 feet. The formation thickens rapidly southwestward from Redding and is conformably underlain 

by the older beds that constitute the Horsetown and the Knoxville. It rests with 

marked unconformity on the older formations around the north end of the Sacramento Valley, and it is unconformably overlain by the lone, which has generally been 

assigned to the Miocene. 

1-K 17-18. ATLANTIC COASTAL PLAIN. 

See contribution by W. B. Clark, Chapter XIV (pp. 608-614). 

J 12. PLATEAU PROVINCE OF UTAH AND COLORADO. 

In southwestern Utah the Upper Cretaceous comprises Colorado strata and 

Montana (~) strata, and the Colorado is coal bearing. The stratigraphy is stated by 

Richardson 669 in the following table and comment: 

Outline of coal-bearing and associated rocks 'in the southern [.'tall coal region. 

-~-------,---------,-------------,-------- -- --

Serie~. Formation. Character. 

------1---------1--~------- --1------------

Tertiary .... _ _ _ _ Eocene................ Wasatch ......... _..... Varicolored shale, limestone, 

sandstone, and conglomerate. 

Cretaceous ..... . 

Unconformity. 

U C t· {Montana(?) ............ Duff sandstone and drab shale .. pper ,re aceous. · · · · · Colorado. __ . ________ .__ Duff sandstone and drab shale, 

Unconformity. 

including workable beds of 

coal in the lower part. 

Jurassic .. __ .... _ ... ____ .. _____ .. ___ .. _____ .... ____ . _____________ _ Varicolored shale and sandstone, 

with lenses of limestone and 

gypsum overlying massive ma- rine limestone. 

Thickness 

(feet). 

500+ 

500± 

2,500± 

800± 

-------'----~-----'-----------~------·-- --- --------

Throughout the plateau province * * * Upper Cretaceous strata lie directly upon beds 

of Jurassic age. * * * A thin bed of conglomerate at the base may be of Dakota age. The 

greater part of the Cretaceous rocks, including the coal, are assigned to the Colorado, but the 

upper few hundred feet contain fresh-water shells and plants of undetermined age, which may 

possibly belong to the Montana. The succession of Cretaceous strata in the southern Utah 

region is unlike that in western Colorado and northeastern Utah, so that the formation names 

used in the coal fields of those areas can not be applied to the rocks in the area under consideration. The coal in southern Utah is older than that in the Uinta Basin region, which includes the 

a For list of fossils see the work cited.-B. W. 
UPPER CRETACEOUS. 671 

Book Cliffs field, the largest and most important in the State. The southern Utah coal belongs 

to the same group as that in theW eber River field. 

The Cretaceous strata which form the escarpment of the Roan or Book Cliffs 

extend south of the fortieth parallel across the basin of Green River and around that 

of Grand River from central Utah to western-central Colorado. They comprise the 

Dakota sandstone, the Mancos shale, and the Mesaverde formation, and are unconformably succeeded by the Eocene. The following section is summarized from 

Richardson: 667 · 

Eocene. 

1J nconformi ty. 

Mesaverde: Alternating buff sandstone and drab or carbonaceous shale, with beds of coal in lower part; shale prevails in 

the lower part, and sandstone in the upper; beds of sandstone lenticular; sections variable; thickness 1,200 to 2,200 

feet, decreasing westward; fossils consist of plants and invertebrates of fresh and brackish water. Transition marked 

by increase of saiHls upward and appearance of brackish and fresh water, in place of marine conditions. 

Mancos: Clay shale, black or blue gray, with local lenses of limestone and near the top thin beds of buff sandstone, contains :Montanv fossils in the upper part and Colorado fossils near the base; thickness about 3,000 feet. 

Dakota: Quartzitic buff sandstone, commonly conglomeratic, with layers of carbonaceous shale and low-grade coal; 

thickness 25 to 200 feet, but formation sometimes wanting on account of irregularities of surface on which it was 

deposited. 

Unconformity. 

The following section is given by Lee 530 in an account of the Grand Mesa coal 

field: 

(}eneralizrd section c:f[ Cretaceous] rocks in the Grand .Mesa coal field, Colorado. 

-------

--

-S-ystem. Group. I Formation. ~!ember. I T~:~:t)~ss I 

I ! 

T . I I ! ~--- --,-----

Characteristics. 

_e_r_tl_ar_y ~-~--'--·---]-unconformity-1-------1-----J---------------

1 

Gray quartzoge sandstone, varying 

from soft and friable to hard and 

.:\fontana. 

Cretaceous. 

Colorado. 

----1--------

Jurassic (?). 

I 

cliff making, and shale with plant 

2,000± remains and shells of fresh-water 

~-------!----~ invertebrates. 

' Paonia shale. I 400+ 1 Shs~~ds~~~~~~U~ ~~a~~ :e:~iis ~:~~ 

l

i ___________ l shells of fresh-water invertebrates. 

Dark-colored shale and gray sand-

;\lesaverde . 

from central part of field.) 1

1 Bowie shale. -

1 

---425 ± l--s-t-on_e_,_c_o_n-ta_i_n-ir-rg_m_a_r_in_e_a_n_d_b_ra_c_k_- ish water invertebrates. (Absent 

I

I Rollins sandstone. 

1----~-

100± White cliff-making sandstone containing marine invertebrates. 

Mancos. 3,000+ 

Dakota. 10-100+ 

Gunnison. 600 

Dark-colored shale, with limestone 

concretions and marine invertebrates. Sandy limestone occurs 

locally near the top, and the base 

consists of black carbonaceous coalbearing shale and flinty sandstone. 

The upper portion is correlated on 

fossil evidence with part of the 

Pierre shale and the lower portion 

with the Benton. 

Conglomeratic sandstone. 

Variegated shale and sandstone ranging from fin3-grained and flinty to 

coarse-grained, conglomeratic, and 

friable. Colored in various shades 

of red, yellow, green, blue, etc. ~- ·-----'---;-----'-------_:_ ___________________________ _ 
672 INDEX TO THE STRATIGRAPHY OF NOR:J'H AMERICA. 

J-K 13-14. EASTERN COLORADO, KANSAS, AND NEBRASKA. 

Darton 238a gives the following general account of the Cretaceous of the Great 

Plains: 

Dalcota-Lakota.formations.-In 1893 Prof. Lester Ward discovered that the so-called Dakota 

sandstone of the Black Hills contained not only a Dakota flora but in its lower beds extensive 

flora of lower Cretaceous age. As the Dakota sandstone in its type region is characterized by a, 

distinct upper Cretaceous flora, it became necessary to restrict the term "Dakota" in the Black 

Hills to the upper sandstone carrying the upper Cretaceous plants. In investigating the stratigraphy of the uplift it was found that the upper sandstone is separated from the lower sandstone, 

which was designated the Lakota sandstones, by a persistent body of shale which has been designated the Fuson formation. In tracing these formations northward, it was found that the 

principal plant-bearing horizon in the northern Black Hills was in the Fuson formation, which 

has yielded a large and beautiful flora of lower Cretaceous plants, which Professor Ward has 

described. The tripartite composition of the old "Dakota" group in the Black Hill~ is very 

distinct throughout the uplift and apparently is a widespread feature in adjoining regions. 

* * * * * * * * * 

Benton group.-The rocks of this group are the most widespread and constant in characteristics of all the sedimentary deposits of the Central Plains region, their salient feature being a 

thick s:lCcession of shales overlying the Dakota sandstone. They present, however, persistent 

subdivisions or horizons of variation. The thickness is variable, ranging from about 400 feet 

in the southeast to 1,600 feet in the Black Hills. 

In nearly all the half million square miles under consideration the group comprises three 

members-a basal, dark shale series known as the Graneros shale, a medial limestone known as 

the Greenhorn limestone, and an upper shale series with sandy layers known as the Carlile formation. Toward its base the Graneros shale includes a horizon marked by local deposits of sandstone; the Greenhorn limestone always presents alternations of slab by limestone and shales; the 

Carlile formation generally has a sandstone bed at or near its top, not far below which concretions usually occur. The Greenhorn limestone is characterized by great colonies of Inoceramus 

labiatus, a species rarely found at all in other horizons; the upper portion of the Carlile contains 

Prionotropis woolgari, which appear to be restricted to that horizon and to characterize it 

throughout the region and even in the Bighorn Basin. Throughout east Wyoming and Black 

Hills region the middle part of the Graneros shales includes, not far above the local sandstone 

horizon a series of hard gray shales and fine-grained thin-bedded sandstones filled with fish 

scales, which weather light gray and from their hardness often give rise to a ridge or cliff. These 

have been termed the Mowrie beds and are conspicuoc:s along both sides of the Bighorn uplift, 

all around the Black Hills, and along the Laramie Front Range to the Colorado line. 

* * * * * * * * * 

Niobrara .formation.-This deposit occupies a wide area in the central Great Plains region, 

succeeding the Carlile without suggestion of unconformity and, except in the vicinity of the 

Bighorn Mountains, consisting largely of carbonate of lime. Its thickness varies considerably 

from apparently less than 100 feet in some portions of eastern South Dakota to 700 feet in centralsoutheast Colorado. 

At the type locality on Missouri River at the mouth of the Niobrara the formation is represented by a chalk rock having a thickness of about 200 feet. In southern Nebraska and Kansas, 

where it appears extensively, the amount is considerably greater, 350 feet being the estimate of 

the Kansas geologists. The formation usually presents purer and harder carbonate of lime 

deposits near its base, constituting the Fort Hays limestone in Kansas and the Timpas formation 

in Colorado. The characteristic fossil of this horizon is the Inoceramus de.formis, which is a 

conspicuous feature in Colorado and for some distance north into Wyoming. 
UPPER CRETACEOUS. 673 

Along the foot of the Rocky Mountains and the Laramie Front Range the formation usually 

presents three limestone layers, a lower massive bed and two upper layers, separated by limy 

shales, the uppermost overlain by impure limestones, which weather to a bright-yellow color and 

always contain flat masses of limestone consisting of colonies of Ostrea congesta. The formation 

thins to the north in Colorado and Wyoming, becoming about 400 feet thick northwest of Cheyenne, and about 200 feet on the slopes of the Black Hills. The bright-yellow color of 

the weathered beds is a conspicuous feature. The point farthest west at which the formation 

was noted is southwest of Casper. It is not characterized along the slopes of the Bighorn Mountains, although doubtless it is there represented by some gray shales, not ·distinguishable from 

those of the adjoining formations, for there is no suggestion of hiatus in the sedimentary series. 

Pierre shale.-The great shale series of the Pierre formation occupies a vast area in the 

central Great Plains and was probably originally of even greater extent, for it appears to have 

been removed by erosion in the mountain uplifts, in eastern Nebraska, and in southern and eastern Kansas. No special investigation has been made of the Pierre stratigraphy, and, although 

the beds seem to be uniform in composition, probably a careful study of the distribution of its 

numerous fossils would show widespread stages. One of these is the upper horizon of concretions with Lucina occidentalis, giving rise to "tepee buttes," which appears to extend from 

Arkansas Valley through Colorado to and all around the Black Hills. In places along the 

western margin of the area great variations in thickness are presented, the shales becoming 

thicker and local sandstone beds being included. West of Denver the formation appears to have 

a thickness of over 7,700 feet, and of considerably over 3,000 feet at Florence and near Boulder. 

Fox Hills formation.-The Fox Hills formation appears to be present everywhere between 

the Pierre and the Laramie, merging into both formations and constituting beds of passage 

between them. In some districts the Fox Hills beds begin abruptly with a sudden change 

from the dark shales of the Pierre to sandstones or sandy shales of the Fox Hills containing 

some distinctive species. It is probable that this change does not take place at the same horizon 

throughout, and the Fox Hills fauna appears in connection with the sandy sediments. 

Usually the Fox Hills deposits are less than 300 feet thick, but in the Denver region, where 

they comprise a thick mass of sandy clays in their lower portion, they attain a thickness of a 

thousand feet. The top member in this region is a persistent characteristic sandstone, 50 feet 

thick, which appears to be the same as the Trinidad sandstone in the Spanish Peaks district 

in south Colorado. The top of the Fox Hills formation is not always clearly definable and in 

most cases can only be placed arbitrarily at the horizon where the first deposits of evident 

fresh-water origin appear. 

The divisions thus distinguished are commonly classified as the Dakota sandstone, the Colorado group (Benton and Niobrara formations), and the Montana 

group (Pierre and Fox Hills of the eastern plains). The term Dakota was proposed 

by King 5050 and given the present definition by Eldridge, 303 who at the same time 

proposed the term Montana. The strata, faunas, and distribution of the Colorado 

have been described in detail by Stanton.m 

K 12. NORTHEASTERN UTAH, NORTHWESTERN COLORADO, AND SOUTHWESTERN 

WYOMING. 

The Cretaceous strata of the eastern Uinta Range were described by Powell 638 

under the names Henrys Fork, Sulphur Creek, Salt Wells, and Point of Rocks 

groups. The latest work in this region has been by Gale, 353 who has described 

the Rangely oil district, which lies in Colorado just north of the fortieth parallel. 

In a correlation table Gale shows that the Cretaceous of western Colorado is now 

48011°--12----43 
67 4 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

divided into five formations-Dakota, ·Mancos, Mesaverde, Lewis, and Laramieand he gives 353ct the relations of this classification to those of Hayden, King, Powell, 

and White, as well as the reasons for abandoning the earlier ones. 

For the Rangely field Gale gives in substance the following account 3530 of the 

several Cretaceous formations: 

The Dakota sandstone presents the following descending section at the southern foot of 

Blue Mountain, a southern outlier of the Uinta Range: 

Section of Dakota sandstone at Willow Greek. 

Feet. 

1. Sandstone, weathered brown (overlain by dark-gray and black slaty shale, supposed to 

represent the base of the :Mancos [Benton])........................................... 10 

2. Shale with beds of white clay and a hard siliceous conglomerate; shale very black and slaty 

near its base. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 

3. Sandstone, white, cross-bedded, containing conglomerate layers......................... 40 

4. Interval, probably shale, covered by sandstone slide rock. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 

5. Sandstone............................................................................ 3 

6. Shale, variegated in colors of pink and green, containing also one or more beds of dense 

reddish-purple limestone .................... _ .. _................................... 95 

7. Conglomerate of coarse, perfectly rounded pebbles in a scant sandy matrix; pebbles largely 

of chert and siliceous material. .. _ .......................................... _ ....... _ 45 

483 

According to Stanton Nos. 4 to 7 may be older than Dakota and may correspond 

to the Fuson or the Lakota (both Lower Cretaceous?) or to the Morrison formation 

(Jurassic?). Farther west, in Utah, the Dakota shows much the same divisions as 

those given above, but the basal conglomerate thins out eastward and the formation 

is reduced to two thin sandstone beds separated by shale. 

The Mancos shale, which overlies the Dakota, is homogeneous, with the exception of a few sandy layers, and is probably nearly 5,000 feet thick. It includes 

Benton, Niobrara, and part of the Pierre, and is characterized by Benton fossils 

near the base and by a Montana fauna having some Fox Hills elements near the top. 

The Mesaverde succeeds the Mancos and is the youngest Cretaceous remaining 

in the Rangely field. It consists of massive sandstones, interbedded with sandy 

shales and many beds of carbonaceous shale and coal. The thickness is about 5,000 

feet. Gale describes its members in detail. 

North of the Rangely field, in southern Wyoming, Cretaceous strata form the 

Rock Springs dome in the great area of Eocene. Schultz 716 describes the strata 

there exposed as Mesaverde, Lewis, and Laramie(?) and says: 

The present investigation led to the conclusion that the subdivisions previously mapped 

by King and Powell could not be applied to the sequence of rock in this region. The fossils 

collected by this party and studied by F. H. Knowlton and T. W. Stanton indicate that the 

several formations have the geologie time values indicated in the accompanying table, where 

the general character and 'succession of the Cretaceous and Tertiary rocks, together with their 

economic importance, are set forth. [Only the Cretaceous part of the table referred to is quoted 

here.] 
UPPER CRETACEOUS. 675 

Cretaceous rocks in northern part of Rock Springs coalfield, Wyom·ing. 

Group. Formation. Economic designation. 

I 

Thickness Description. (feet). 

Massive basal bed of white and yellow 

sandstones, showing traces of conglomLaramie(?). Black Buttes coal group. 2,371± erate in places; forms pr<•minent scabt. 

The overlying bed consists of variab e sandstones, clay, and coal beds. Fossils abound in places. 

Dark-gray, drab, and black shales, highly 

Lewis shale. 750± gypsiferous, with some soft shaly sandstone and large concretions. Produces 

region of low relief. 

Almond coal group. 900 

Soft white and brown sandstones, sandy 

shale, and clay with numerous beds of 

coal and bituminous shale. 

Massive white and yellowish sandstones, 

with little shale and ferruginous matter. 

. 800 Upper third conglomeratic, with fine 

black and gray quartz pebbles. Sand-

' stone forms pronounced escarpments 

and hogback ridges. 

Mesaverde. White to yellow sandstone, interbedded 

Montana. Rock Springs c o a 1 shale and clay with several large coal 

2,400 bed& ranging from !1 few inches to 2 or 3 group. feet. The heav1est sandstones are grouped near the base of the formation. 

Drab, yellow, and brown sandstones and 

interbedded shale and shaly sandstone 

860 with little or no bituminous matter. 

Massive sandstones are grouped near top of formation, giving rise to the 

" Golden \Vall." 

Shaly sandstone and arenaceous shale, in 

I 940 places highly gypsiferous. Much of it 

I 

very friable, producing low benches 

and badland ndges. 

j 550+ I Black and drab shales, very soft and friable. 

The Cretaceous of southwestern Wyoming has been described by Veatch, 839a 

who gives the following classification from Jurassic up to Eocene, inclusive, the 

upper and lower parts of his geologic column not being here quoted: 
Section in southwestern Wyoming. 

Systems and Formations. Character of rocks. Thickness 

groups. (feet). 

Bridger. Bridger formation ...... Greenish sand and clays, composed largely of volcanic ash, with occasional calcareous white bands 1,200-1,800 

filled with fresh-water shells. Contains a large mammalian fauna. 

Green River formation .. Predominantly light-colored calcareous beds, characterized by light-colored thin-bedded shales with c 2,000± 

Green River. abundant fish and plant remains. Layers of dark bituminous shales show near Fossil at base of 

formation. ---·-

Knight formation._ .. _ .. Variegated yellow and red sandy clays, with irregularly bedded white and yellow sandstones. Con- 500-1,500± 

c5 tain Coryphodon and other animal remains. >< 

<ll ~~Unconf< rmitv~~~ -~-...... "'--'~~''--'"~~~~~~-~-~-~~ '--'""~~~~~~ 

'-' Fowkes forrrmtion· ... _ .. "White beds;" light-colored rhyolitic ash beds with interbedded limestones containing fresh-water 0-2,500+ rS Wasatch. shells, fish, and plants. 

Almy formation._ ...... Yellow and reddish-yellow sandy clays, 

glomerate beds. 

with irregularly bedded sandstone and near the base con- 2,100-2,200 

Evanston formation .... Yellow, gray, and black carbonaceous clays, with irregular yellow sandstone, in places conglomeratic. 0-1,600+ 

I "Upper Lara- Several coal beds. Characterized by plants which are distinctive of the upper Laramie or De11ver 

mie.'' beds, and by invertebrates, some of which are common to the Laramie and Fort Union. Rests on 

I Bear River and Beckwith beds. ~~ -~~~ 

~~~Unconformity~~~"- ~~~~~-~~~~~~-~~~~~~-~~~~~~~~-~~~~~~~-~~~~~~-~---

Adaville formation, with Yellow, gray, and black carbonaceous clays, with irregularly bedded brown and yellow sandstones and 4,000+ 

'' Lo"rer Lam- basal Lazeart sand- numerous coal beds. South of Hodges Pass tunnel there is at the base of this formation a prominent 

mie.'' stone. white sandstone, 100 to 200 feet thick. Immediately above this is the Ada ville-Lazeart coal, 2D-84 feet 

thick, and associated with it are beds containing plants and invertebrate remains, which are older -- ----~ -·-- ------- than Laramie. The overlying strata contain lower Laramie leaves. -· ---·-----

Montana. Hilliard formation ...... Gray to black sandy shales and shaly sandstones, which weather readily and produce a region of low 5,fi00?-G,SOO 

relief, Mammoth Hollow, affording few exposures. West of Frontier and 3,000 to 3,800 feet above 

the base of the formation there are several thick lenses of white sandstone. These contain numerous .; Niobrara. specimens of large Inoceramus exogyroide8, a species characteristic of the basal Niobrara or upper ;::J 

C· Benton in the Cretaceous east of the Rocky Mountains. <ll 

(..J 0 ---------

Zl Frontier formation, with Alternating beds of yellow and gray sandstone and yellow, gray, and black carbonaceous clays with 2,200-2,GOO <ll '0 I Q "' .... ;::J Oyster Ridge sand- numerous coal beds. Forms pronounced parallel ridges or hogbacks. Contains distinctive Benton 0 

I 

c '2 stone member. fossils. In upper part of formation is a pronounced bed of coarse sandstone, occasionally conglom- 0 

Q "' era tic, containing numerous large oysters. This is the "Oyster Ridge sandstone." ~ 

Aspen formation._ ..... Black and gray shales containing abundant fish scales; often weathering silvery gray. 1 ,500-2,000 

Bear River, Da- Bear River formation .. _. Dark-colored shales with thin-bedded shaly sandstones and limestones, containing abundant inverte- 500-5,000± 

kota?, and brate fossils and seveml thin beds of impure coal. 

Lower Creta- -~ --

ceous? Beckwith formation .... Red, yellow, and reddish-yellow shales and sandstones, at many places containing thick reddish con- 3,S00-5,500 

glomerate beds. 

Jurassic. Twin Creek formation .. _ Black and gray shales and shaly limestones with occasional beds of yellow sandstone, the whole con- taining numerous characteristic marine upper Jurassic fossils. 

3,500-3,SOO 

~-
UPPER CRETACEOUS .. 677 

The numerous formations listed in the above table are described in detail by 

Veatch, who states the general relations as follows: 839d 

The exact base of the Cretaceous in this region is not known. The lowest fossiliferous 

Cretaceous beds are clearly near the base of the Upper Cretaceous, and the Dakota, as well as 

the Cretaceous beds which Darton has found beneath the Dakota in eastern Wyoming, if they 

exist in this region, are thus inferred to be represented in the upper part of the Beckwith formation. The top of the Cretaceous is likewise in doubt, involving, as it does in other parts of the 

Rocky :Mountains, rather conflicting lines of stratigraphic and paleontologic evidence. In the 

present discussion the Cretaceous is made to terminate with the great dynamic revolution which 

interrupted the period of relative quiescence in this area, which extended without important 

interruption from the earliest Carboniferous to late Cretaceous time. These disturbances produced important folds and faults, involving the movement of these sediments through thousands of feet. This known portion of the Upper Cretaceous series has the enormous thickness 

of over 20,000 feet. Its fossils indicate that it contains the time equivalents of the Benton, 

Niobrara, Montana, and Laramie groups of the eastern section, but the natural lithologic subdivisions do not correspond with these faunal subdivisions and do not agree with those east of the 

Rocky .Mountains. There is in this section an entire new member-the Bear River formationcharacterized by brackish and fresh water forms, which, although attaining lJ, great thickness, 

is essentially of local development. 

Regarding the division line between the Cretaceous and the Eocene of southwestern Wyoming, Veatch 839e makes the following statement: 

In the Wasatch group as thus defined by Hayden the field work of the season of 1905 showed 

three divisions-(!) a basal member composed of reddish-yellow sandy clays, in many places 

containing pronounced conglomerate beds, which has been named the Almy formation; (2) a 

great thickness of light-colored rhyolitic ash beds containing intercalated lenses of white limestones with fresh-water shells and leaves, the Fowkes formation; and (3) a group of reddishyellow sandy clays with irregular sandstone beds closely resembling (1) lithologically and 

separated from (1) and (2) by a pronounced period of folding and erosion. The last group has 

been called the Knight formation and is the horizon of the Coryphodon remains found in this 

vicinity. The Almy and Fowkes formations belong, with the Evanston, in the conformable 

series separated on the one hand by a pronounced period of folding and erosion from the Laramie 

beds, and on the other from the Coryphodon Wasatch beds by a period of folding and erosion of 

great magnitude though of much less importance than the one between the Adaville and the 

Evanston. The fossils from the Almy and Fowkes have, without exception, been considered 

Eocene, but the formations are treated with the Evanston because of their very intimate stratigraphic relation to it and the stratigraphic isolation of the Evanston, Almy, and Fowkes from 

the beds above and below. Whether it can ever be conclusively proved from the limited 

paleontologic data available that the line between the Cretaceous and Eocene should be drawn 

in this section between the Evanston and Almy, so that one great physical break will be thrown 

into the Cretaceous and the other secondary physical break into the Tertiary, is very doubtful. 

Stratigraphic geologists will, in the absence of very positive paleontologic data to the contrary, 

and none such exist at present, favor taking one physical break or the other for the line between 

the Cretaceous and Tertiary, preferably the earlier and greater one. The Knight formation is 

not in dispute and has therefore been treated under the Eocene. 

The formations distinguished by Veatch in southwestern Wyoming have been 

identified and traced northward from the forty-second parallel to the Gros Ventre 

Range by Schultz.a 

In the Wind River Basin, which lies northeast of the western Wyoming area 

just described and is separated from it by the Wind River Range, the stratigraphic 

a Unpublished manuscript. 
678 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

development of the Cretaceous is more like that of the Rock Springs dome and other 

areas farther north, though the upper beds are largely concealed by overlap of the 

\Vind River Eocene. Woodruff 948 has described the part of the basin that is 

included within the Lander oil field and gives the following tabular description of the 

Cenozoic and :Mesozoic formations: 

Geologic formations [Cenozoic and Mesozoic] in the Lander oil field. 

Era. System. Series. Group. I :Formation. Character. Thickness (feet). 

--

I Quaternary. Recent. Alluvium. 

CJ 

·s 

~ Sandy shale, shaly i:'i 

Q) \Yind River for- sandstone, and Only the lower Tertiary. Eocene. u mation. local beds of con- part exposed. 

glomerate. 

-- Unconformity 

Mesa verde forma- Massive light-buff Less than 200 

tion. sandstone and feet exposed. Montana. sandy shale. 

Drab sandy shale 

merging upward 

Upper Cretaceous. Mancos shale. into moderately 6,110. 

Colorado. rusty very sandy 

shale. 

Creta('eous. 

Dakota sandstone. Massive ferruginous 

sandstone. 20 to 56. 

Shale, sandv, and 

sandstone !n both CJ Lower Cre.ta- massive and ·c: shaly beds and 400 to 410. N ceous (?). - w 

0 beds of conglom- Q) erate locally de- ~ veloped. 

Variegated sandy 

shale and c o n - Jurassic(?). Morrison formation. glomerate com- 236 to 242. 

posed of water- worn pebbles. 

Sundance form a- Olive-green fossilifJurassic. tion. erous limestone 347 to 350. 

and shale. 

Chugwater forma- Sandy shale and 

Tdassic (?). tion (''Red massive sand- 1,500. 

Beds"). stone. 

K 13. NORTHERN COLORADO AND WYOMING. 

In northwestern Colorado Cretaceous strata outcrop between the pre-Cambrian 

of the Park Range and the Tertiary of the wide basin on the west. Just north of 

the fortieth parallel is the Yampa coal field, which has been examined by Fenneman and Gale.329 They give the following section: 
UPPER CRETACEOUS. 679 

Generalized columnar section in Yampa coal field, Colorado. 

Cretaceous: Feet. 

Laramie formation-sandstone and shale, with coal ..... ___________ --_-_-_______ 1,000 

Lewis shale-dark shale, calcareous layers.---_: ________________ ------------_-_ 1,000-2,000 

Mesaverde formation-sandstone, shale, and coal seams. _________ -------------- 2,500-3,500 

Mancos shale-dark shale, containing limestone and sandstone layers. ____________ 2,000-2,500± 

Dakota formation-conglomerate and shale .... _________________ ----- ---- -- - _- _ 200 ± 

Jurassic-Triassic (?) "Red Beds" (Triassic to Carboniferous?). 

Archean (ancient crystalline and metamorphic rocks). 

The Dakota and Mancos present no special peculiarities. The Mesaverde, 

being the coal-bearing formation, was studied in detail and yielded the following 

generalized section: 

Generalized section of the Mesaverde formation in Yampa coalfield, Colorado. 

Sandstones (occasionally massive) and shales, containing coal, especially in upper part (upper Feet. 

coal group) ...................... __________________________________ - _ - _- _- _--- _- _ - _--- _- _ 400 

Twentymile sandstone member ............ __________________________ -_---_---------------- 75 

Weak sandstones and shales, with frequently a prominent ledge-making yellow sandstone about 

250 feet from the top. ______________________________________________ - _- _____ - _- _- ___ - _- _ 600 

Sandstones (occasionally massive), shales, and coals of the middle group ...................... _ 400 

Trout Creek sandstone member ____________________________________ .

1

• _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 75 

Shales and weak sandstones, with few massive beds, containing in the lower part the upper seams of the lower group of coals .... ____________________________ _ _ _ _ _ _ __ __ _ _ _ _ __ __ _ _ __ __ 400 

Massive sandstone, with subordinate shaly sandstones and shales, containing near the top the 

lower seams of the lower group of coals .............. ____ _ __ _ _ _ _ _ _ _ _ _ _ _ _ __ __ _ _ _ _ __ _ __ _ _ _ _ _ 750 

Slab by or shaly sandstones with some shales, frequently having greater strength at two or three 

horizons, on erosion giving rise to hogbacks .......... ____________________________________ 750 

3,450 

Above the coal-bearing Mesaverde lies the Lewis shale, a marine formation 

between 1,000 and 2,000 feet thick, which grades into the sandstones below and 

above by thin sandy_ strata. The Lewis is followed by the "Laramie," a terrane 

characterized by sandstones and coal beds, with shales, which occupies the stratigraphic position of the Laramie of adjacent areas but from which in this district 

no fossils have been obtained. A part of the "Laramie" is shown to have a 

thickness of 312 feet, but this is presumably but a small part of the thick terrane. 

North of the Yampa field the Cretaceous outcrops range into Wyoming, on 

the southern boundary line of which Ball 53a determined the following section: 

Section of Cretaceous rocks in the western portion of the Little Snake River coal field, Wyoming. 

Thickness (feet). 

Formation. Description. North end South end 

of field. of field. 

Brown and gray shaly and concretionary sandstones and 

dark shale, with several beds of coal. In the southern 

Laramie formation. end of the field the lower half is yellow, softer and more 4,000 0-2,500 

sandy and apparently contains little coal. Marine 

fossils in base. 

Lewis shale. Drab, slightly sandy, highly gypsiferous shale, with a few 1,600 2,300 (?) 

P.. thin, soft sandstones. Not coal bearing. 

;:l 

0 Upper and lower members consist of heavy sandstone 61 

'" Mesaverde formation. with a few interbedded shales. Intermediate member 2,500 Bottom not ~ consists of shaly sandstone and shale. Upper member seen. '" ..., coal bearing . ~ 

0 

;:s Dark-drab concretionary calcareous shale, with several Bottom not seen. I thin, soft brown :;andstones. Not coal bearing. - --- -----
680 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Still farther north the following section of the Cretaceous in southern Wyoming 

west of Rawlins was observed by E. E. Smith 752a in the Great Divide Basin coal 

field: 

Section of Cretaceous rocks of Great Divide Basin coalfield, Wyoming. 

I 

Thickness (feet). 

Group. Formation. General characteristics. 

South end 

I 

North end 

of field. of field. 

Alternating layers of yellowish-brown and white massive sandstones, thin brown sandstone, and drab, brown, and black 

(?) Laramie. 3,900± 1,050 shales. Sandstones are very resistant in southern portion. 

At north end the sandstones in the basal part are more resistant 

than those in the upper part and constitute prominent topographic features. i 

i 

In southern part of the area it consists of very dark drab shale 

Lewis shale. 

with considerable gypsum and several thin layers of rusty 

1,520± 520 sandstone. In the northern part of the area it consists of 

drab shale and soft yellowish-brown sandstone containing 

~ I some thin layers of gypsum. Produces a region of low relief. 

I "" I 1:1 

0 Near the top and at the base are two massive white sandstones ~ Mesaverde. 3,600± 2,000± which are resistant and form two prominent ridges or hogbacks. Between them is a soft brown sandstone interbedded 

with drab to brown shale. 

I Upper portion is exposed only at south end of field and consists 

---- of soft brown shaly sandstone interbedded with drab to brown 

(a) 5,000± I 4,000± shale. Lower portion consists of very dark drab calcareous I 

shale, containing numerous thin, soft brown sandstones near 

the top. Produces areas of low relief. 

Frontier sand- Three massive yellowish-brown sandstones with dark shale bestone member. 900± 500 tween, contaming numerous concretions. Upper sandstone 

ci i is slightly conglomeratic. I "1j I "" '" 

I 

0 

0 Mowry shale I Compact gray and black shales which break with conchoidal 0 700± 1,000 member. fracture and contain abundant fish scales. 

30± 20± :3Iassive yellowish-brown to pink sandstone resembling Dakota. 

100± 60± Black shale which breaks with conchoidal fracture. 

Dakota sand- 100-150 

I 

100-175 Massive vellowish-brown to pink sandstone, containing small 

stone. chert pebbles near base. Locally quartzitic. 

a This formation is equivalent to the ~iobrara and the basal shale portion of the Montana. A local name will 

probably be applied to it. 

Regarding the formations, Smith remarks: 

The coal-bearing formations show considerable change in character from the southern to 

the northern edge of the field. Those of the Cretaceous system thin rapidly toward the north 

and the outcrops of the beds of the undifferentiated Tertiary become more and more narrow, 

owing to the overlap of Wasatch conglomerate. The accompanying section [above] shows the 

thickness and general characteristics of the coal-bearing formations near the Union Pacific 

Railroad and in the gap between Whisky Peak and the Ferris Mountains. 
UPPER CRETACEOUS. 681 

East of Rawlins the Cretaceous strata extend around the Park and Medicine 

Bow ranges into the Laramie Plains. They surround the Fort Union (Tertiary) in 

the Hanna coal field of Carbon County. Veatch 841 has reported on the section, in 

which he found a marked unconformity between the "Lower Laramie" (equivalent 

to Laramie of Denver Basin) and the "Upper Laramie" (Lance formation). He 

gives the following classification: 

Generalized section of Cretaceous and Tertiary rocks of central Carbon County, Wyo. 

----,------,------------------,-----------------

~~~ Group. I Formation. I 

------- ·-

Thickness 

(feet). Characteristics. 

---------l------------------------1---------------------·--------------------

North Park. 

Unconformity. ~~~ 

Fort Union. 

"Upper Laramie." 

Unconformity. ~~--

'' Lo·wer Laramie. '' 

4,500 

1,200± 

6,800± 

6,500 

White volcanic-ash beds, cherty bands; base conglomeratic. 

Dark-colored shales and shaly sandstones. 

Dark-colored shales and gray to brown, irregularly bedded 

sandstones; coal bearing. Contains conglomerate at base 

composed largely of pebbles derived from the underlying 

Cretaceous rocks. Fresh-water fauna. 

Dark-colored shales and gray to brown, irregularly bedded 

sandstones: coal bearing. Fresh-water fauna. 

______ 1 ___________________ 1----------- 1-----------------------------------------------

Lewis. 1' 800-3' 000 

Mesaverde 1,500-3,200 

Pierre shale.a 3' 000-:-3' 500 

Shales and shalysandstones. Coal bearing. Has in parts of 

fteld a very persistent white sandstone near top. Marine 

and brackish-water faunas. 

White to yellow sandstones and interbedded shales, coal 

bearing, producing areas of marked relief. Heaviest sandstones are grouped near top and at base of formation, and 

thus produce, under favorable conditions, two terraces or hogbacks. 

D>trk-gray to brown, sandy, concretionary shale and thin, 

soft shaly sandstones, producing areas of low relief. 

1-------1 ------------------1 --------- -- ------- -------------------------------------

Kiobrara. 

I 

750-850 Dark-colored, very calcareous shale, weathering light gray. 

----,-------------, .. --

150 Black shale. 

0 Frontier. "Cl 

"' d .... 

..s 0 0 ..., Mowry. u ~ 

"' 

l-------------l-----------1------------------------------------------------

400-800- _j Brown sandstones and shales, producing marked ridges. 

300-750 Black fish-scale shale, weathering silver-gray . 

I=Q ------------- ----------- ------------------------------------------------

10-15 Yellow quartzitic sandstone, resembling the Dakota. 

60-150 Black shale, with thin coal beds. 

Dakota. I 80-125 Coarse conglomeratic sandstones. 

----~------------------------~----------~-----------------------------------------------

a It is the belief of Dr. T. W. Stanton that the ~Iesaverde and part of the Lewis also belong to the Pierre, as that 

formation is developed east of the Rocky Mountains. A local name will therefore probably be applied to this lowest 

division of the Montana in this region. 
682 lNDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

K 14-15. IOWA AND :MINNESOTA. 

In Iowa the Cretaceous is represented by the Dakota sandstone and the Colorado group. The Dakota is exposed in the western part of the State where it was 

originally studied and was named from the town of Dakota, Nebr., on Missouri 

River. It is also penetrated in many artesian wells and has a thickness of 50 to 

100 feet. The formation consists of more or less calcareous shale and sandstone, 

with thin bands of lignite.586 

The Colorado exhibits a section of shale and chalky limestone, having near 

Hawarden, Iowa, a thickness of 50 feet but elsewhere ranging from a thin edge to 

150 feet. The strata carry Prionocyclus wyomingensis, Inoceramus labiatus, and 

Ostrea congesta. Selenite is of common occurrence in the shales. 

In Minnesota the Cretaceous is widely distributed over the western part of the 

State but so heavily covered by drift that but few outcrops appear. Hall 394a 

gives a total of 500 feet of beds, white sandstone of the Dakota at the base and soft 

blue shale and incoherent sandstone of the Benton above. 

K 18. LONG ISLAND. 

The Cretaceous strata which appear along the northern shore of Long Island 

have been carefully correlated with the New Jersey section by Veatch, 837 a who concludes that the "basal beds are the stratigraphic equivalents of the Raritan and 

are Upper Cretaceous. The Matawan beds are apparently well represented but their 

character changes going seaward" to gray sands and clays. "No greensand beds 

comparable to the great greensand marl beds of New Jersey have been found, their 

stratigraphic position being occupied by fine lignitiferous sand with occasional clay 

beds." Hollick 460 expresses another view. 

K 19. MASSACHUSETTS. 

At Gay Head and elsewhere on the island of Marthas Vineyard are exposures of 

the Vineyard series of Shaler/28a which comprises Cretaceous strata and Miocene 

beds (unconformable~) upon them. Shaler says_: 

The Gay Head section consists of three divisions. The central part (that is, that part 

which faces nearly west) has a length of about 3,500 and an average height above the sea of 

about 80 feet. At the southern end of this section there is an exposure of about 2,000 feet in 

length, which trends toward the southeast. At the northern end of the principal section there 

is another short and incomplete section which trends nearly east and west. These three divisions constitute one great and nearly continuous sea cliff having a length of over 6,000 feet. 

* * * * * * * * * 

The face of this cliff shows us a great number of thick, steeply inclined beds of sand, clay, 

and lignitic matter, of extremely vivid and contrasted colors. The colors range from the 

dazzling white of the sandy beds to the nearly pure black of the carbonaceous layers, with 

intermediate hues of brown, green, yellow, and red. * * * 

The orderly arrangement of the beds in the section is greatly masked by the continued 

slipping of large wedges of the deposits down the steep incline of the talus. When we apply a 

correction for this slipping the beds are seen to lie in a tolerably regular order, dipping usually 

to the northeast, with inclinations varying in general from 20° to 60° of declivity but rising 

in one place to 90°. 
UPPER CRETACEOUS. 683 

In 1890 Shaler was able to reexamine the section at Gay Head, then more clearly 

exposed by exceptional rains, and determined that the strata were closely folded, 

not monoclinal. He distinguished certain divisions of the ''Vineyard series" as 

follows: 730a 

The section at Gay Head is apparently divisible into two tolerably distinct elements, viz, 

a lower division, the upper limits of which are not determined, which is likely to prove of Cretaceous age; and an upper part cif the section, which from the fact that it contains bones of cetaceans is likely to prove of Tertiary age-the two together forming the greater part of the longitudinal section of Gay Head. Above these two more ancient portions of the escarpment lies 

an extended series of unfossiliferous sands, which apparently belong to a somewhat later age than 

the other portion of the section. To this age we may also presumably assign the extensive 

series of beds exhibited in the W eyquosque series. These later-formed beds are, at least in the 

W eyquosque cliffs, deposited unconformably upon the earlier series. A portion of these later 

unfossiliferous sands are involved in the contortions at Gay Head, and a portion of them lie 

unconformably upon the edges of the beds which were involved in the dislocation. It seems 

likely, therefore, that this later series will in the end be found divisible into two parts-a portion which was laid down before and a portion formed after the greater part of the disturbance 

had been effected. 

Shaler was in doubt as to the age of the different divisions. White 894 identified 

a number of Cretaceous plants from "several localities and horizons in the Vineyard 

'series.'" Dall 209 described Miocene faunas apparently from the same closely 

folded strata, and Pliocene forms from sands which lie unconformably upon them. 

(See Chapter XVII, p. 823.) 

Supposed Cretaceous clays have been reported in well borings in Boston. W. 0. 

Crosby 184 was the first to suggest that these clays were pre-Pleistocene. Later 

F. G. Clapp 139 reported these distinctive clays from several wells in Boston, and 

discussed in detail the boring at Ames Building, the samples of which he examined 

critically. The following log and notes are taken from Clapp's paper: 

Record of boring at Ames Building, Boston. 

Thickness. Depth. 

Feet. Feet. 

Coarse sand and gravel. . . . ........................................................... . 17 17 

Sand ................................................................................. . 1 18 

Gravel and band ...................................................................... . 5 23 

3 26 

16 42 

Coarse gravel and white clay ............................................................ . Stony sand, gravel and clay with much water (very hard) ................................ . Blue clay .............................................................................. . 18 60 

Fine sand ........................................... ---- ... --.---- ...... ----------.--- .. 5 65 

12 77 

136 213 

Clay, sand, and gravel, with water (till) ................................................. . Hard dry nearly white clay, with bowlders .............................................. . Slate (Carboniferous) ................................................................... . 15 228 

The material below 77 feet is dry and in a previous boring had been called rock and not 

entered by the drill. All the samples of this bed were seen by the writer and found to consist 

mostly of a very fine grained gray to white clay, which became plastic when wet. It varied 

from very soft and putty-like to nearly as hard as the underlying slate. The material when 

examined by Dr. W. T. Schaller, of the United States Geological Survey, was found to consist 

of Si02=59.18 per cent and (Al20 8, Fe20 8, PP5, Ti02)=27.11 per cent, thus being a very 

pure clay. * * * 
684 INDEX TO 'l'HE STRATIGRAPHY OF NORTH AMERICA. 

This clay is important for the reason that it is unlike the general type of clay found at 

Boston. All the Pleistocene clays of the vicinity are of blue-gray to brown or buff colors; this 

clay is light gray to nearly white. The Pleistocene clays contain numerous bowlders and pebbles composed of all kinds of rock found in New England, but in this clay only two bowlders 

have been discovered, and these consist of rock only found in the vicinity of Boston, and which 

forms the bedrock of the region. The Plei~ocene clays are interstratified with glacial deposits; 

this clay rests on bedrock and is separated from the overlying Pleistocene clay by a bed of till. 

This clay is much dryer than the overlying Pleistocene clay. * * * 

Samples of the white clay from the Ames Building boring were compared at the office of 

the United States Geological Survey with samples of clay collected by Mr. Veatch from anumber of borings on Long Island, New York, and found to agree very closely with them in appearance. Mr. Veatch has correlated the Long Island deposits with the Raritan formation of New 

Jersey .. If this correlation is correct, it is possible that the Boston deposits may be of similar 

age. This is rendered more probable by the similarity of the material in the Boston borings to 

some of the clays on .Marthas Vineyard. 

K-L 12-13. NORTHERN WYOMING. 

The Bighorn Basin, in northern "Wyoming, is surrounded by Cretaceous strata 

which Fisher 331b described under the names Morrison, Cloverly, Colorado, Pierre, 

and Laramie and associated formations. Recent surveys by Woodruff 947a yield the 

following section of the southwestern portion of the Bighorn Basin : 

Section along Shoshone River near Cody, Wyo. 

I I 

System. Formation. I Thickness Characteristics. (feet). 

Wasatch formation. [Seep. 774.] 

Tertiary. Unconformity. 

Fort Union formation. 3,100 [Seep. 774.] 

Unconformity (?) 

Laramie (?) formation. 2,630 Dull green sandy shale with local brown leaf-bearing beds 

and gray massive sandstone. 

;::;., Undifferentiated In lower part gray massive sandstone and dark-colored ~andy ;::; 760 shale in alternating layers; in upper part dark and light 0 Montana. '" gray shale alternating, and numerous lignitic beds. CD 

ol 

~ 

,S 

Cretaceous. ~ Gray massive sandstone, weathering tan, and gray sandy 0 Eagle sandsto.ne. 220 ..... shale with dark coaly bands. Locally coal bearing . .-; 

Black to dark-gray shale with rusty l'andstone at base and 

Colorado shale. 3,375 gray massive sandstone at short intervals in lower half. 

Thin beds of coal occur a little below the middle. 

Cloverly formation. 300 I Gray, green, and maroon shales and gray compact sandstone. 

As shown in the above table, the thickness of sandstone and shale between the top of the 

Colorado formation and the great unconformity at the base of the Wasatch formerly mapped 

by Fisher a as "Laramie and associated formations" is here tentatively subdivided into Eagle, 

undifferentiated .Montana, Laramie 0), and Fort Union. These formations are suggested on 

a Fisher, C. A., Prof. Paper U.S. Geol. Survey ~o. 53, 1906, p. 8. 
UPPER CRETACEOUS. 685 

lithologic and paleontologic evidence. * * * At the beginning of the field season, in the 

absence of definite fossil evidence, differences in lithology alone were accepted as a basis for the 

subdivision into formations. A subsequent study of the fossils, both in the field and in the 

laboratory, by T. W. Stanton and F. H. Knowlton, has shown that the lithologic units do not 

coincide in all particulars with the formations as they are recognized farther north and elsewhere. Fossils collected at various localities in the fields point to the presence of the Eagle 

and Laramie formations, though the evidence is not conclusive, as many of the species are either 

new or heretofore unknown to the formations, and strictly characteristic specimens are Lacking. 

A fresh-water fauna which contains forms suggestive of upper Montana occurs in beds between 

the Eagle and Laramie (?). There is abundant fossil evidence to prove the presence of the 

Fort Union formation. A suggestive break occurs at the base of the conglomerate beds noted 

in the table, which was thought in the field to be an unconformity at the base of the Fort Union, 

but later study of the plant collections shows that Fort Union forms occur a few feet below this 

horizon. As the final determinative evidence has not been obtained, the divisions shown in 

the table are only provisionally introduced. 

For notes on the northeast side of the Bighorn Basin, see L 12-13 (p. 690). 

K-L 13. SOUTH DAKOTA AND NORTHWESTERN NEBRASKA. 

Darton 232• 

233• 237 • 238 has described the strata 'of South Dakota and northwestern 

Nebraska in several publications. In the Newcastle folio 236 he gives the local 

development of the Cretaceous as follows : 

Upper Cretaceous: 

Laramie formation-massive soft buff sandstone with concretions and carbonaceous shales. 

Fox Hills formation-thin hard sandstone in sandy shale, and soft clayey sandstone below. 

Pierre shale-dark gray shale or clay with concretions containing many fossils. ________ _ 

Niobrara formation-gray calcareous shale, and impure chalk. ______________________ _ 

Carlile formation-variable gray shale. ______________________________________________ _ 

Greenhorn limestone-thin bedded, hard gray limestone, with lnoreramuslabiatus. ___ _ Graneros formation-dark shale .. ___________________________________________________ _ 

Dakota sandstone-gray to buff sandstone mostly very massive. ______________________ _ 

Lower Cretaceous: 

Fuson formation-gray to red shales with thin sandstones. ___________________________ _ 

Lakota sandstone-massive cross-bedded gray to buff sandstone, with local coal beds and 

·conglomerate. ___________________________________________________________________ _ 

Morrison shale-massive sandy shale and fine sandstone. _____ .. _______ . _____________ _ 

Unconformity. 

L 10. WESTERN WASHINGTON. 

Feet. 

800 

75-150 

1,_250 

200 

700 

.so 

1,001) 

50-100 

15-30 

150-200 

150 

Cretaceous sandstones are supposed to form a large part of the Olympic Peninsula, in \Vashington. Arnold 29a examined them on the western coast and states: 

The rocks supposed to be Cretaceous in age, the correlation being based on their stratigraphic position and lithologic character, are confined to the western coast of the peninsula. 

They extend over most of the territory from 1! miles south of Point of the Arches to 1 mile north 

of Cape Elizabeth and consist almost entirely of a coarse gray sandstone, with occasional zones 

of black shale and rarely a little conglomerate. The thickness of the formation is. probably 

over 5,000 feet, although, owing to its complex structure, this is only a very rough approximation. 

L 10-11. JOHN DAY BASIN, OREGON. 

(See Chapter XIV, p. 621.) 

L 12-13. EASTERN IDAHO, NORTHWESTERN WYOMING, AND MONTANA. 

Cretaceous strata occur here and there in the Yellowstone Park and vicinity. 

Stanton 779 reported on the strata and their correlation and showed that representatives of the Colorado and Montana are present. Certain strata which were • 
• 

686 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

doubtfully referred to the Dakota are now a regarded as in part referable to the 

Kootenai and in part probably to the Bear River. 

In an unpublished manuscript F. C. Calkins describes and correlates the Colorado 

formation in the Philipsburg quadrangle, Montana, as follows: 

Immediately above the Kootenai formation in the Philipsburg district is a very homogeneous accumulation of fissile black shale whose upper part contains thin beds of low-grade 

coal near Drummond. On Mount Princeton the shale is about 450 feet thick. The greater 

part of the shale. is barren of fossils, but according to Dr. Stanton it lithologically resembles 

the Colorado shale of areas farther east. Immediately above the coal near Drummond a Unio 

which may be of Colorado age was found. 

At the top these shales pass by a rapid gradation into beds dominantly arenaceous, attaining 

a thickness of mdre than a thousand feet. They consist mainly of greenish flaggy sandstones 

but comprise considerable shale and several beds of conglomerate. 

In the lower part of the sandstone on Mount Princeton and about 4! miles east of Drummond, very imperfect specimens doubtfully referred by Dr. Stanton to Mactra and Callista were 

collected which appear to be of Colorado age. About 1! miles southeast of Drummond a small 

collection of plants from a horizon a few hundred feet above the base of the sandstones is reported 

upon as follows by Dr. Knowlton: b 

"There are three things in this little collection-a Marchantia which is probably new, a 

conifer which is probably a Glyptostrobus, and a fern that is pretty close to if not identical with 

Aspidium oerstedi Heer. The latter is from Patoot, which=Senonian=Fox Hills. I can not 

place this material definitely, but should incline to regard it as possibly Upper Cretaceous." 

In 1910 .Mr. Pardee collected more satisfactory fossils from a limestone outcrop in Coberly 

Gulch, 10 miles north-northwest of the northeast corner of the quadrangle. The exact position 

of the horizon is not known; the limestone bed, however, is underlain by about 400 feet of 

sandstone and shale similar to those above the black shale, so that it is virtually certain that 

the fossils occur at least 400 feet stratigraphically above the main body of black shale. 

The list of forms identified by Dr. Stanton and his comment on thein follows: 

6552. Specimen No. 10-P, 4. NE. i NW. 1 sec. 34 and SW.l sec. 27, T. 10 N., R. 12 W., Granite County, Mont. 

Modiola sp. 

Cyrena securis White. 

Corbula sp. 

Glauconia coalvillensis Meek. 

Admetopsis subfusiformis Meek. 

"The horizon is in the Colorado group. The same association of forms occurs in the Oyster 

Ridge sandstone member of the Frontier formation of southwestern Wyoming." 

By way of summary it may be said that lithologic and paleontologic evidence put the 

correlation of the black shale and about 400 feet of the overlying beds with the Colorado beyond 

reasonable doubt. It is probable, however, that some beds of Montana age occur in this district. 

Calvert 115 describes the Cretaceous of the Lewistown coal field, in central 

Montana, as follows: 

The Lewistown coal field *. * * lies between longitude 109° and 110° 15' west, and 

the 47th parallel divides it into two nearly equal portions. It is thus located in the center 

of Montana, including the west-central part of Fergus County and a few square miles of northeastern Meagher County. The greater part of the field lies in the Judith Basin, a name applied 

to the upper drainage area of Judith River. * * * The Little Belt and Big Snowy mountains are in the southern part of the field and the Judith and South Moccasin groups lie well 

within its northern borders. The area as described includes about 1,500 square miles. * * * 

The rocks of the Lewistown coal field range in age from lower Carboniferous to Quaternary, 

inclusive. * * * The succession of the rocks and the relation of the principal coal-bearing 

beds to strata above and below are shown in the following generalized section: 

a Stanton, T. vV., comment on manuscript. b Personal communication to Dr. Stanton. 
UPPER CRETACEOUS. 

Generalized section of sedimentary rocks in the Lewistown coal field. 

Claggett formation (Upper Cretaceous): White and brown sandstone in lower part and greenish 

sandy shale above. 

Eagle sandstone (Upper Cretaceous): 

l<'eet. 

Shale, dark bluish, containing carbonized wood fragments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 

Sandstone, soft, yellowish, cross-bedded, containing iron concretions and woody fragments.. 53 

Sandstone, soft, white, usually without bedding .......................................... 170 

Sandstone, white, with coaly layer at top................................................ 10 

Colorado shale (Upper Cretaceous): 

Shale, dark gray to black, with a few thin sandy members ................................ 720 

Sandstone, hard, greenish, weathering brown, fine grained, ferruginous..................... 3 

Shale, dark gray to black, with a hard bed 420 feet above base ............................ 675 

Sandstone, grayish brown, thinly bedded, containing an abundance of fish scales (supposed 

Mowry)............................................................................. 47 

Shale, dark gray to black, alternating hard and soft layers ................................. 890 

Sandstone and shale, alternating, brownish in color throughout........................... 25 

Kootenai formation (Lower Cretaceous): 

Shale, maroon, argillaceous..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 

Sandstone, grayish, coarse grained, cross-bedded......................................... 8 

Shale, maroon, argillaceous ................ ·............................................. 60 

Sandstone, gray, coarse grained, cross-bedded ................ _ ..... _.................... 25 

Shale, maroon, argillaceous ............................... _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 

Sandstone, massive, coarse grained to pebbly, weathering soft gray........................ 50 

Coal and coaly shale ............................. _ ......... _._ .... _ .. _ .. _............... 10 

Shale and sandstone, alternating; the shale is sandy and the sandstone thinly bedded..... 87 

Morrison formation (Jurassic?). 

687 

The above section, being compiled from measurements made in several places in the field, 

should not be considered as a type of any one locality. 

The Colorado shale decreases in thickness northward from the Big Snowy Mountains, for a 

section of that formation to the south of the uplift shows that the interval between the Kootenai 

red shale and the Eagle sandstone is 2,400 feet, whereas the same interval 15 miles northeast of 

Lewistown is less than 1,600 feet. 

Throughout the field the Kootenai is fairly uniform in thickness, although the individual 

members comprising the formation vary locally. As a formation it is readily distinguished 

by the bright maroon-colored shales and by the coarsely cross-bedded sandstone just above the 

coal. 

In 1908 Stone 798 gave an account of the Cretaceous and Tertiary rocks surrounding the Crazy Mountains, west of longitude 115°. Further studies in 1908-9 by 

Stone and Calvert 799 led to a revision of the classification and nomenclature, which 

is expressed in the following table and notes abstracted from their report: 

Stratigraphy of the Upper Cretaceous and early Tertiary in the vicinity of the Crazy Mountains, 

.iV!ontana. 

Fort Union formation, 4,000+ feet: Massive sandstones and intercalated shales. 

Lebo andesitic member, 450-2,200 feet: Fort Union fossils; Torrejon 

mammals. 

Lance formation ("Laramie" or "Ceratops beds"), 1,000-2,400 feet: Lightgrav sandstone and variegated shales. (Stanton thinks equivalent to L" · to f t' • . . . 1vmgs n orma 10n as Laramie of Denver Basin. Knowlton thmks 1s Fort Union.) · · II d fi d f . . ongma y e ne or Lennep sandstone, 250-460 feet: Dark-colored sandstone w1th mtercalated l'th 1 . "t ( . . . . a 1 o og1c un1 an- shales. Few foss1ls. Not defimtely correlated w1th Fox H1lls sandstone. desitic material). 

Bearpaw shale. 

Judith River formation. 

Claggett formation. 

Eagle sandstone. Livingston flora nearly through this sandstone. 

Colorado. 

Kootenai (Lower Cretaceous). 

Jurassic. 
688 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The following notes give the substance of Stone and Calvert's remarks, though 

not a literal quotation. 

In the upper valley of Musselshell River and north of the Crazy Mountains the 

basal Cretaceous rocks belong to the Kootenai formation, which rests conformably 

on the Morrison formation. The Kootenai is 235 feet thick, is composed of shale 

and sandstone, and is not coal bearing. It is overlain conformably by Colorado 

shale, about 1,300 feet thick, prevailingly dark colored and carrying marine invertebrates. 

The four formations of the Montana group, Eagle, Claggett, Judith River, and 

Bearpaw, are found here. The Eagle is mainly massive sandstone, about 200 feet 

thick, and in some places carries coal which usually is unworkable. The Eagle is a 

conspicuous ledge or ridge maker. The Claggett is composed of dark shale3 and 

white to light-brown sandstones of marine and brackish-water origin, from 400 to 

800 feet thick, and is overlain by the Judith River formation, which has about the 

same range in thickness. The Judith River is prevailingly of fresh-water origin, 

carries thin beds of coal, and has fossil shells, bones, and wood. 

Above the fresh-water Judith River is the upper marine Cretaceous shale, 

700 to 1,000 feet thick, known as the Bearpaw shale. This shale is commonly 

dark-colored and has fossiliferous limy nodules. The Cretaceous section is normal 

to the top of the Bearpaw. Resting on these marine shales and evidently of a 

transitional nature is about 300 feet of dark-colored fresh and brackish water shale 

and sandstone. The stratigraphic relation of these beds is like that of the Fox Hills 

sandstone. but enough fossils have not yet been obtained to make the correlation 

positive. These beds are more or less tuffaceous. 

There is some question as to the age of the overlying Lance formation, which 

is 1,000 to 2,400 feet thick and composed of light-colored fresh-water sandstone and 

shale. The paleobotanic collections are ascribed by Knowlton to the Fort Union, 

but the vertebrate and invertebrate fossils point to Cretaceous age for the same 

beds. There is no doubt that they should be in part correlated with the "Cera tops 

beds," but whether the latter are Cretaceous or Tertiary is as yet unsettled. 

Resting conformably on the Lance formation is another series of tuffaceous 

sandstones and shales. The beds are about 2,200 feet thick at the north end of 

the Crazy Mountains and 460 feet on Fish Creek northeast of the mountains. They 

are of Fort Union age and will be described in future papers as the Lebo andesitic 

member of the Fort Union formation. 

The youngest consolidated strata in the Crazy Mountains are the massive sandstones and shales of the Fort Union formation. They are of fresh-water origin and 

are shown to be Tertiary both by plant and by animal remains. The thickness 

is unknown but exceeds 4,000 feet. 

At the north end of the Crazy Mountains the Upper Cretaceous formations 

gradually lose their distinctive lithologic characteristics, and all from the Eagle to 

the massive sandstones of the Fort Union become merged into a single series of 

tuffaceous beds several thousand feet thick and constituting a single lithologic unit. 

On the west side of the Crazy Mountains, therefore, the Eagle sandstone is overlain 

conformably by a great series of sediments more or less andesitic in composition 
UPPER CRETACEOUS. 689 

and varying in age from lower Montana to Tertiary. These in turn are overlain 

by the Fort Union. 

The Kootenai (Lower Cretaceous) and Colorado formations extend northwestward from the fields described and have been traced around the Big Belt Mountains, 

according to Fisher, 332b who says (see also Chapter XIV, pp. 621-623): 

The Colorado shale rests with apparent conformity upon the underlying Kootenai and is 

overlain conformably by the Eagle sandstone, the lowest member of the Montana group. 

Although conformable relations appear to exist between the Kootenai and Colorado formations 

in this region, the Dakota, which occupies a position between these two formations in other localities, is, as previously stated, believed not to be present. If this is true, there is a hiatus at this 

contact representing at least several hundred feet of beds. It is possible that Dakota time is 

here represented by marine sediments not easily separable from the Colorado shale. 

The Upper Cretaceous section of central Montana was established by Stanton 

and Hatcher,785 from whose report the following general facts are abstracted: 

The Benton (or more properly the Colorado, as more than the Benton is 

included) consists of dark clay shales with intercalated bands of sandstone, especially in the upper portion, and frequent calcareous concretions. The fossils of the 

lower portion are Inoceramus labiatus, Scaphites warreni, and others. The upper 

part yields Inoceramus umbonatus, I. exogyroides, Pholadonya papyracea, Scaphites 

ventricosus, Baculites asper ( ~), and many other forms. The total thickness is 

estimated at 800 feet. 

Immediately above the Colorado is the Eagle formation. At its base the Eagle 

consists of sandstones and shale which grade into the underlying shale, but its 

conspicuous member is a massive light-colored cross-bedded sandstone, more than 

100 feet thick. Above this member are softer beds of sandstone together with shale 

and lignite. Fossils are scarce but include, of invertebrates, Cardium speciosum, 

Thetis ?circularis, Jl1actra alta, Placenticeras whitjieldi?, and others, and, of vertebrates, remains of the dinosaur Ornithomimus grandis. The thickness is probably 

300 feet or more. 

The Claggett formation is a body of dark clay shales, about 400 feet thick, 

which rests on the Eagle. In the upper part are yellow sandstone beds, and the 

passage into the Judith River is by gradual transition. The lower part of the 

Claggett contains Gervillia borealis, Baculites ovatus, Baculites compressus, and other 

characteristic Pierre forms. The sandstone beds contain a fauna which "has long 

been considered a typical 'Fox Hills' fauna." Stanton concludes that "faunas 

similar to that of the Fox Hills sandstone have a great vertical range and are likely 

to be found at any horizon within the Montana group where a littoral or shallowwater facies is developed." 

The Judith River consists chiefly of fresh-water deposits together with layers 

laid down in brackish water, especially near the top. There are also local marine 

beds. Workable coals occur in the upper portion. The thickness is about 500 feet. 

Extended descriptions of the Judith River formation are given in the bulletin cited. 

The Bearpaw shales are marine and succeed the prevailingly fresh-water 

Judith River. They are dark clays which include many calcareous concretions. 

The thickness is estimated at 750 feet. The commoner forms in the varied invertebrate fauna are listed in Stanton and Hatcher's report. 

48011°--12----44 
690 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The grounds for distinguishing the Eagle, Claggett, Judith River, and Bearpaw 

formations as divisions of the Montana group are fully stated, their correlations are 

discussed, and special reports on the faunas and the flora are presented. 

The distribution of the Cretaceous and early Tertiary in eastern Montana is 

shown as determined by the special surveys of coal fields a and reconnaissances 

connecting them. 

Notes relating to the development of the sequence in particular fields (Lewistown coal field, Crazy Mountains, Livingston district, and Great Falls coal field) 

are given elsewhere in this chapter. 

For the northeast side of the 

following section of the Cretaceous. 

Bighorn Basin, Washburne 867 determined the 

(For Tertiary, see p. 775.) 

Cretaceous rocks on northeast side of Bighorn Basin. 

Series. Group. Formation. Thickness Characteristics. (feet). 

Laramie (?) formation.a 150-700 Massive sandstone with subordinate shale. 

Contains workable coal. 

Bearpaw shale. 150 Dark marine shale. 

Judith River formation. 300-400 Variegated clays and soft sandstone. 

Upper Creta- Montana. Massive fresh and brackish water sandClaggett formation. 400-500 stones and dark shale. Coal not work- ceo us. able. 

Massive fresh and brackish water sandEagle sandstone. 150-225 stones, separated by carbonaceous shale. 

Contains workable coal. 

Dark shale with one or two conspicuous 

sandstones, not divisible in this field, 

Colorado shale. 4,400 though more than 1,500 feet of the lower 

part is known to be equivalent to the 

Benton shale. 

Unconformity 

Lower Creta- Bright-colored clays, with massive sand- ceous (?). Cloverly. 0-275 stones at the top and bottom. 

workable. 

Coal not 

a The evidence is not sufficient to class this formation as undoubted Laramie, consequently the term is used throughout this report in a questionable sense. 

In the wide basin southeast of the Bighorn Mountains near longitude 106° 

and latitude 43° the general section of the Cretaceous is, according to Shaw: 735a 

Cretaceous: 

Montana-upper two-thirds principally sandstone with coal; lower third dark shale with no coal. 

Colorado-mostly dark-brown shale with some orown sandstone layers, and at the top a buff to 

white sandstone, which may be Niobrara. Near the base is the Mowry member, a very resistant 

dark shale which weathers white. 

Cloverly-massive, brown, resistant sandstone, which commonly forms a pronounced hogback. 

Near the top there is some shale, and at the bottom a fine conglomerate. 

a Bull. U. S. Geol. Survey Ko. 316, 1907; No. 341, 1909. 
UPPER CRETACEOUS. 691 

Of the formations Shaw writes as follows: 

The coal-bearing rocks described above are unconformably overlain by Tertiary and Quaternary formations. The ·white River, a Tertiary formation of white sandy clay and conglomerate, covers a considerable area in the southeastern part of the field. It is spread over parts 

of all the older formations, and is even found high up in the.mountains. The so-called Chalk 

Buttes, 3 miles southwest of Douglas, are also composed of Tertiary rocks, and the outcrop of 

similar rocks extends westward for 25 miles along the foot of the mountains. 

L 13-14. SOUTH AND NORTH DAKOTA. 

A representative section of the Cretaceous of the Great Plains northeast of the 

Black Hills is given by Darton. 245 

Generalized section [of Cretaceous] for the Belle Fourche quadr_:angle, South Dakota. 

Sys- Se- Formation name. Character of rocks. tern. ries. 

----

Fox IIills sandstone. Sandstone, light colored and slabby below, massive and yellowish to pinkish above. 

Pierre shale. Limestone concretions that give rise to "tepee buttes." 

Dark-gray shale with numerous concretions. 

Niobrara formation. Soft impure limestone or chalk and limy shale with thin limestone masses composed of Ostrea congesta. 

en 

I Carlile shale. 

------------·- -- ~ ----~---~ - ;::j 

0 Gray fissile shale with numerous ferruginous limestone concre- Cl 

'-' tions. Thin sandstone near bottom. " ..., 

Cl 

en ... Q ;::j 

0 ... Greenhorn limestone. I Impure gray slab by limestone with shale intercalations . Cl Cl 

'-' p.. 

" p.. ..., Cl p 

Q '"' Gray fissile shale with scattered concretions. Thin bed of 

sandy limestone near middle and bentonite near base. 

Graneros shale. 

Mowry shale member, composed of hard gray shale and finegrained sandstone, weathering light gray and containing numerous fish scales. 

Local bed of sandstone. 

Dark fissile shale with concretions and thin sandstone layers near base. 

Dakota sandstone. Gray to brown sandstone, mostly massive below, slab by above. 

en 

;::j Fuson formation. Gray to purple sandy shale and thin sandstones. ... 0 Cl Cl 

~ '-' o-.5 

....:1CJ ... Lakota sandstone. Gray to buff sandstone, massive to flaggy, mostly hard . Q 

Cretaceous Morrison shale. :\fassive sandy shale, greenish gray to maroon. or Jurassic. 

Leonard 532 recognizes in the Upper Cretaceous of :North Dakota the Laramie, 

Montana (Fox Hills and Pierre), Colorado (Niobrara and Benton), and Dakota. 

He describes the strata in detail, but they present no special peculiarities. 

In a later discussion of this area 533 Leonard refers the Laramie of his previous 

:report to the Lance and Fort Union formations and says concerning the strata of 

the Lance formation that "they have the same stratigraphic position as the Laramie 

formation, with which they correspond in whole or in part." 
692 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

M 9-10. VANCOUVER ISLAND. 

The Cretaceous of Vancouver Island forms three areas-the Nanaimo, Comox, 

and Quatsino, named from southeast to northwest. There are local differences of 

stratigraphy among the basins, but in general the terrane closely resembles that of 

Queen Charlotte Island, except that the two lower formations of that island are 

lacking on Vancouver. Dawson 256b states: 

In the northern part of Vancouver Island the Cretaceous which still remains appears to 

consist of outliers of a distinct and older basin and may probably be regarded as having been 

originally continuous with that developed in the Queen Charlotte Islands. The Cretaceous 

rocks of Quatsino Sound have so far afforded the best sections, and in these we appear to find 

the three higher members of the Cretaceous section of the Queen Charlotte Islands, as it exists 

in the vicinity of Skidegate Inlet. * * * In comparing these with the corresponding rocks 

of the Queen Charlotte Islands it is probable that the thickness of the Quatsino beds is somewhat less and that the conditions met with in the lower or coal-bearing portion of the series 

are more distinctly littoral at Quatsino, sandstones and conglomeratic layers being relatively 

more important. The Cretaceous rocks which extend along the northeast shore of Vancouver 

Island, from Port McNeill to Beaver Harbor, may in part represent the lowest or coal-bearing 

portion of the Quatsino section. A few fossil plants obtained from Beaver Harbor are Middle 

Cretaceous and possibly referable to a horizon near that of the lowest beds at Quatsino, but 

are regarded by Sir William Dawson as distinctly newer than these, though possibly older than 

much larger collections since made at Port MeN eill, which have not yet been worked up in detail, 

the N anaimo and Comox Cretaceous floras. It is thus evident that we have not merely a single 

horizon to deal with along this part of the northeast coast. No traee of the lower subdivisions 

represented at Skidegate (D and E) has yet been found on Vancouver Island. 

The relations of the Cretaceous rocks of the Queen Charlotte Islands and those of the 

northern part of Vancouver Island, as now understood, may be expressed as below, in tabular 

form: 

Queen Charlotte Islands. Northern part of Vancouver Island. 

Upper Cretaceous. A. Upper shales and sandstones, 1,500 A. Port McNeill beds(?). 

· feet. Upper shales. 

"-~-----

B. Coarse conglomerates, 200 feet. 

C. Lower shales and sandstones, with 

B. Coarse conglomerates. 

C. Lower sandstones and shales with coal. 

Middle Cretaceous. coal, 5,000 feet. 

D. Agglomerates, 3,500 feet. D. Wanting. 

E. Lower sandstones, 1,000 feet? E. Wanting. 

In the course of the examination of the Cretaceous rocks of the northern part of Vancouver 

Island, it has been found that these rest unconformably on a rough and irregular denudation 

surface of the older rocks. * * * Owing to this circumstance the higher Cretaceous beds 

successively overlap the older rocks, and as the areas of these beds which have escaped subsequent denudation are probably to a great extent those which have filled the deeper portions of 

the hollows, it follows that the actual outcropping edges of the beds rarely give a complete 

section of the entire thickness of the formation. 

In 1873 Richardson 671 made a report on the N anaimo anQ Comox fields, which 

contains numerous detailed sections of the Cretaceous strata. Dawson 259 summarizes the facts as follows: 

The rocks accompanying the coals are sandstones, conglomerates, and shales, being largely 

of the character of littoral formations but also containing, particularly in the shaly members of 
UPPER CRETACEOUS. 693 

the series, truly marine fossils. They hold also in some layers abundance of fossil plants, and 

in appearance and degree of induration much resemble the older Carbcniferous rocks of some 

parts of eastern America. Coals of a workable character have been found only in the lower 

part of the Cretaceous series, which is represented with closely similar characters in the Comox 

and Nanaimo areas. The somewhat variable character of the Cretaceous measures as a whole 

is, however, shown by the fact that Mr. Richardson found it necessary to adopt a different. 

scheme of subdivisions for the two areas, notwithstanding their general correspondence. The 

sections at Com ox and N anaimo are as follows, in descending order: 

Comox. Nanaimo. 

Feet. 

Upper conglomerates ........................ . Upper shales ................................ . Middle conglomerates ........................ . 

Feet. 

320 

776 

1,100 

76 

Sandstones, conglomerates and shales ................ 3,290 

Middle shaies ................................ . 

Lower conglomerates. ______ ......... _......... 900 Shales.............................................. 660 

Lower shales ..... _. ___ . __ ._ ...... _............ 1,000 Productive coal measures............................ 1,316 

Productive coal measures ...... ___ ............. 739 

4,911 5,266 

The age of the productive coal measures of N anaimo and Com ox is approximately that of 

the Chico group of California, in which, however, in its typical locality, coaJs are not found. 

M 11. CANADIAN ROCKIES, ALBERTA AND BRITISH COLUMBIA. 

George M. Dawson 255b classified and described the Cretaceous of the Canadian 

Rockies as follows: 

The sections representing the upper part of the Cretaceous rocks of the mountains are, 

unfortunately, very unsatisfactory, the best being that of the Northwest Branch. * * * 

The volcanic beds are there followed by dark shales which afford a few fossils referred to the 

Benton group and are estimated to attain a minimum thickness of 1,400 feet. Above these 

are sandstones and shales, generally of pale tints and possibly several hundred or a thousand 

feet in thickness, which are supposed to represent the Belly River series of the plains to the eastward. A concealed area beyond these is presumed to be underlain by the Pierre shales, and 

still higher in the section are beds referable to the base of the Laramie, with characteristic fossils. 

The thickness of the Laramie at this place is indeterminate but .must be considerable. * * * 

A provincial general representation of the Cretaceous beds of the mountains of this region, 

as compared with those of the plain to the east, may be given as follows, in descending: 

Rocky Mountains. 

I 

Foothills and plains. 

o.i Feet. Feet. "§ Porcupine Hill beds ......................... 2,500 

"" ... \Villow Creek beds ............... _ .......... 450 

I "" St. Mary River beds (base) ............... Not known. St. Mary River beds ........................ 2,800 .-1 

Fox Hill and Pierre ..................... Not known. Fox Hill and Pierre .......................... 830 

Belly River series ....................... Not known. Belly River series .......................... 910 

00 Benton and (Niobrara?) ....................... 1,400 "Lower dark shales" ........................ 800 ;:l 

0 Volcanic rocks (greatest thickness) ............. 2,200 0) 

'-' _g D~~~eb!!tn;h~~fzrfna_r_t_ -~f- -~~~-~~~~. ~~~i~~- ~~ 2,750 0) 

... Lower part of Kootanie series ................. 7,600 0 --- 13,350 8,290 
694 INDEX TO THE STRATIGHAPHY OF NORTH AMERICA. 

T. W. Stanton comments as follows on the foregoing section: 

The lower part of the strata Dawson referred to the Kootenai in this region doubtless 

includes some marine Jurassic. (See Whiteavcs, Description of a species of Cardioceras from 

the Crows Nest coal fields: Ottawa Naturalist, vol. 17, 1903, pp. 65-67.) This Jurassic ammonite is one of the fossils mentioned by McElroy as occurring in the lower beds of the Kootenai 

below the coal and plant-bearing l;wrizon (Rept. Geol. Survey Canada, vol. 13, 1900, p. 91A). 

McConnell's description 559a supplements that given by Dawson: 

The Cretaceous is essentially a clastic formation and contains beds ranging through every 

degree of coarseness, from fine-grained fissile shales to heavy conglomerates. 

* * * * * * * * * The lower part of the series consists mainly of beds and bands of fiaggy sandstone, alternating with dark shales. The shales are usually somewhat arenaceous and pass gradually, 

by the addition of more sandy material, into pure sandstones. They are also occasionally 

carbonaceous and in a number of places inclose coal seams, some of which are workable. The 

sandstone occurs characteristically in somewhat thick beds and is usually coarse grained and 

soft, but harder quartzitic beds are not altogether absent. It weathers to a dull red color. 

The bands of sandstone are little persistent and if traced along their strike for any distance 

are found to break up into subordinate beds, separated by thin shaly partings, or to pass altogether into shales. The upper part of the section contains some conglomerate, in addition to 

the shales and sandstone. This occurs in massive beds, measuring up to 150 feet in thickness, 

and is composed of rounded siliceous pebbles, with some shaly and calcareous grains, embedded 

in a hard siliceous matrix. The pebbles are usually small, seldom exceeding an inch in diameter, 

and the rock passes insensibly into sandstone. The section here is more arenaceous than is 

usually the case, and there is reason to believe that it occupies a comparatively high position 

in the series and that the lower part contains a greater proportion of shales. The Cascade 

River section, a few miles farther north, which is undoubtedly lower, shows no conglomerate, 

and the sandstones are also of less importance, and in nearly eyery case where beds of Cretaceous age overlie the Banff limestone in an undisturbed condition, showing that tho base of the 

formation is present, they consist almost entirely of dark shales. 

* * * * * * * * * The following fossils were collected near the base of a small Cretaceous outlier situated 

3 miles north of the east end of Devil's (Minnewanka) Lake: Oxytoma mucronata, Trigonia intermedia, Trigonoarca tumida,a all three charaeteristie of the Queen Charlotte Island series, and 

species of Terebratula, Ostrea, Camptonectes, Lima, Cyprina, ammonites, and belemnites. 

A small collection, obtained from the shales faulted under the Cambrian limestones at 

the gap of the south fork of Ghost River, includes amongst others, such Benton species as 

Scaphites ventricosus and possibly S. warreni, and an Inoceramus like I. undabundus. 

McEvoy 564 gives a detailed section of 4, 736 feet of Cretaceous beds in the 

Crows Nest Pass basin near Morrisey and notes 1,000 feet or more of shaly limestone 

and calcareous shales below the measured section, as well as 4,000 to 5,000 feet of 

soft shale and sandstone above it. He concludes that the total thickness of Cretaceous strata in the Crows Nest Pass basin is 12,000 to 13,000 feet. 

M 12. NORTHWESTERN MONTANA. 

In northwestern Montana, at the eastern base of the Rocky Mountains, Cretaceous strata form the valley floors and foothills. In a reconnaissance survey in 

1901 Willis 940a distinguished Dakota, Benton, and Laramie. ------------------------------------------------------- ·-- ------ a' 'Most probably Jurassic" [Fernie shale].-T. W. Stanton. See also statement by D. B. Dowling in Bull. Geol. 

Soc. America, vol. 17, 1906, p. 298. 
UPPER CRETACEOUS. 

Laramie sandstone [a]: Sandstone, hard, gray, cross-bedded, and Joft, shaly, interbedded, carrying 

layers of oyster shells and containing plant remains. 

Benton shale: Shale, dark bluish gray, very fissile, fossiliferous, with occasional beds of sandstone, 

medium grained, brown, and thin limestone layers. 

Dakota sandstone: Sandstone, yellow and brownish, and shale, arenaceous, with plant remains and 

fresh-water shells. 

695 

A recent reconnaissance b by l\1. R. Campbell and C. A. Fisher shows that 

the Colorado is exposed in a broad strip extending from the Big Belt Mountains 

north by west, possibly to or into Alberta. This strip is flanked on both sides by 

the Eagle sandstone and higher formations of the Montana group, including the 

Judith River. 

M-N 11-14. PLAINS OF ALBERTA, SASKATCHEWAN, AND MANITOBA. 

Dawson's classification of the Cretaceous strata of the southwestern part of the 

Great Plains in Canada is given on page 693 in comparison with that of the Cretaceous 

in the Rocky Mountains. The Athabaska and Peace River sections are described 

on pages 699-700. 

The standard section of the Upper Cretaceous of Canada was established by 

Dawson 254 in a study of the region between the base of the Rocky Mountains and the 

meridian of 110° 45', near Medicine Hat, on th_e South Saskatchewan. Dawson's 

classification is as follows: 

Laramie: . Feet. 

Porcupine Hill beds: Sandstones, frequently thick bedded and generally comparatively soft, 

with intercalated grayish and blackish shales and shaly clays. Fresh water __ .. ____ ... _____ 2,500 

Willow Creek beds: Soft sandstones, shales, clays, and sandy clays, generally with pronounced 

reddish or purplish tint. Fresh water._ .... ____ .. ______ . _______ . _____ .... ___ ... _____ ._____ 450 

St. Mary River beds: Sandstones, shales, and shaly clays in frequent alternations, and generally 

well bedded. Fresh water except near base ..... _ ....... ___ ... ___ ....... __ .......... _..... 2,800 

Cretaceous: 

Fox Hill sandstones: In some parts of the district well defined as a massive yellowish sandstone, 

but inconstant, and apparently often represented by a series of brackish-water transition 

beds between the Laramie and the Pierre ..... _. _. _ .. ___ ..... ___ ... ____________________ . _ _ _ 80 

Pierre shales: Neutral gray or brow·nish to nearly black shales, include a zone of pale soft sandstone in the northeastern part of district, and frequent intercalations of harder sandstones near the mountains. Marine._ .... ____ ..... ___ .. _________ . ___ . ______ ... _____ .__________________ 750 

Belly River series: Composed of an upper or "pale" and lower or "yellowish" portions and consisting of alternations of sandstones, sandy clays, shales, and clays .. _______________ ._ .. _____ 910 

Lower dark shales: Gray to nearly black shales, frequently with arenaceous shales._ .. ______ ._. 800 

Details of occurrence and local character of each of these formations are given 

in the subsequent pages of Dawson's report and he states his interpretation of the 

geologic history. 254 a 

The region east of that examined by Dawson, lying between the mendians of 

106° and 110° 50.', was studied by McConnell/58 who recognized Belly River, Pierre, 

and Fox Hill, overlain conformably by the Laramie, and the latter overlain unconformably by Miocene. 

a "The 'Laramie' of this section is probably Judith River or older. The distinction between Laramie and Judith 

River was not generally recognized when these fossils were examined."-T. W. Stanton. 

b Data contributed from manuscript records of the United States Geological Survey. 
696 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

On the North Saskatchewan and its tributaries Tyrrell 816 distinguished the 

following beds: 

Laramie: Feet. 

Paskapoo series: Gray and brownish weathering lamellar or massive sandstones and olive sandy 

shales. This is an exclusively fresh-water deposit.......................................... 5,700 

Edmonton series: Soft whitish sandstones and white or gray, often arenaceous clays, with bands 

and nodules of clay ironstone and numerous seams of lignite. These are of brackish-water 

origin and correspond to the lowest portion of the St. Mary River series of Dr. Dawson's report 

(Geol. Survey, Rept. for 1882-84, p. ll4c).. .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 700 

Fox Hill and Pierre: Brownish-weathering sandstones and dark-gray clay shales.................. 600 

Belly River series: Soft whitish sandstones and arenaceous clays, changing toward the east to lightbrownish and yellowish sandstones and sandy shales; bottom not seen. 

In the foothills evidence was found of the presence of rocks of the age of the Benton shales, 

which immediately underlie the sandstones of the Belly River series, but our knowledge of 

them is as yet too imperfect to allow of our treating of them in any way, and we can therefore 

simply record their occurrence. 

No intrusive rocks occur anywhere throughout the district, and below the top of the 

Laramie there is no evidence of any unconformity between the different formations, although 

in some cases the extreme irregularity of the bedding gives the strata very much the appearance 

of having been laid down unconformably one on the other. 

[The Belly River series is represented by] white or light-gray clays and soft clayey sandstones, 

interbedded with bands and nodules of clay ironstone. These nodules are often highly calcareous, breaking with a smooth, sharp fracture. Toward the center, on a freshly broken surface, they are of a clear slate-gray color; around are darker and darker layers, till the outer one, 

which is very dark brown, almost black. 

As has already been pointed out in the reports of Dr. Dawson and Mr. McConnell, this 

series, if followed toward the east, is found to lose gradually its clayey character and to consist 

of purer and much more massive sandstones, generally of a yellowish color. 

The Fox Hill and Pierre are described by Tyrrell as consisting ofdark or light gray, very friable clay shales, weathering down into a soft tenacious clay, interbedded with bands of coarse-grained yellow sandstone. Unlike the beds both above and below, 

it is of purely marine origin, having been laid down in a sea of varying though generally very 

considerable depth. 

The thickness of the formation, wherever it could be measured, was found to be from 600 

to 700 feet. 

* * * * * * * * * It is quite impossible here to separate the Fox Hill sandstone from the Pierre shales, as they 

are completely interbedded from the top to the bottom of the group. In descending Battle 

River this is particularly noticeable; as at the top of the group yellow sandstones are met with 

containing Placenticeras placenta, teredo burrows, etc., and at the bottom a sandstone quite 

undistinguishable from that above is seen holding precisely the same fossils. In the southern 

part of the district, nodules of clay ironstone are common throughout the shale, and fossils are 

plentiful, both in the nodules and in thin bands of included sandstone, but to the northward, 

fossils become much more rare and new species begin to appear, which are not known to the 

south. 

The fossils found in the district, so far as known at the time of the report, are 

listed by Tyrrell to the number of 32 species. 

No workable beds of coal occur in this group within the district, though in the shales on 

the top of the high ridge to the north of the Neutral Hills a thin band of carbonaceous shale is 

seen over a considerable area, and at Egg Creek, near the North Saskatchewan, there is a thin 

seam of coal of fine quality. 
UPPER CRETACEOUS. 697 

For an account of the Edmonton and Paskapoo series, see Chapter XVI 

(pp. 781-782). 

In the eastern portion (M-N 13-14) of the area under consideration the classification of the Cretaceous differs from that given for the western portion (M-N 11-12) 

in the recognition, by Tyrrell, 817b of Dakota, Niobrara, and Benton. Tyrrell gives 

the following systematic account in a report which contains also many local details: 

The Dakota sandstone formation, resting unconformably on the limestones of the Devonian, 

is composed of white or reddish sandstones, either cemented by a calcareous matrix or often 

quite incoherent, being then an even-grained white quartzose sand. It grades up into a lightgree,p and rather hard sandstone, commonly interstratified with thin hands of shale. 

Very few fossils have been found in this sandstone, and those that have been found are confined to the greenish upper beds. 

Overlying the Dakota sandstones, the Benton formation occurs as a band of dark-gray, 

almost black shale, holding a considerable quantity of carbonaceous material. This shale is 

evenly bedded and breaks <lown readily into thin flakes, on which account it generally forms 

sloping banks. With the dark shales are associated thin beds of white, soft, sweet-tasting 

magnesian clay. 

It is generally quite destitute of fossils, but in a few places undeterminable fragments of 

oysters and Inocerami have been collected from the shale. 

. * * * * * * * * * 

The Niobrara formation conformably overlies and is an upwanl extension of the Benton. 

The rock, however, insten'l of being a soft fissile shale, with little or no admixture of calcareous 

material, is a lighter-gray calcareous shale or marl, sometimes varying to a band of moderately · 

hard limestone. This is especially the case at the top of the terrane, where a band of grayish 

chalky limestone is generally met with. This band is often highly charged with pyrite. 

A very characteristic feature of the formation is the presence of a large number of Foraminifera, among which Globigerina cretacea is often very conspicuous and in great abundance.a 

The terrane varies considerably in thickness. In the :Manitoba Oil Co.'s bore on Vermilion 

River it appears to have a thickness of 130 feet. On North Pine Creek its total thickness is 

less than 400 feet and probably is not more than 200 feet. On Bell River it is probably less 

than 250 feet. In the Swan River valley, near Thunder Hill, it would seem to have a thickness 

of 540 feet, but it is quite possible that the upper beds represent a foraminiferous horizon in 

the overlying Pierre formation. 

This terrane is known to extend southward through the western portion of the province of 

~fanitoba, having been recognize<l in the valleys of the Assiniboine all<l other streams near the 

face of the Manitoba escarpment and in the borings from the deep wells at Morden and Deloraine. 

It is doubtless continuous with the Niobrara shales and limestones, originally described by Messrs. 

~Ieek and Hayden, from the banks of the Missouri River in Nebraska. Northwest of the area 

now described a fragment of typical Niobrara rock was collected from Carrot River, about 

west longitude 103°, by Mr. A. L. Russell, beyond which it has not been traced, and its exact 

correlation with the beds on Athabasca River is not yet known. 

* * * * * * * * * 

Grading upward fwm the top of the Niobrara formation the Pierre shales occupy the 

summits of all the higher lands of the Riding, Duck, and Porcupine mountains. In the Riding 

Mountain and farther south this formation naturally separates itself into an upper and a lower 

subdivision, which the writer has elsewhere called the l\lillwood and the Odanah series.b 

* * * * * * * * * 

Farther west the Pierre is highly fossiliferous, but in northwestern Manitoba fossils are 

very scarce, and of those recorded in the following list a the Radiolaria are from a bed of shale on 

a For list see the work cited.-B W 

b Tyrrell, J B., The Cretaceous of Manitoba: Am. Jour. Sci., vol. 40, 3d ser, 1890, pp 227-232. 
698 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Bell River, and the remainder are from ironstone nodules from the west bank of the Assiniboine 

Valley at Millwood, a short distance south of the present map. 

The total thickness of the Pierre in northwestern Manitoba is 800 feet or more. The 

Millwood series, as seen in the valleys on the northern face of riding Mountain, has a thickness of 

between 450 and 500 feet, while about 300 feet of the overlying Odanah series is there also 

seen, reaching to near the summit of the mountains and being immediately overlain by the 

drift deposits. The top of the Odanah series is not seen. 

0 4-5. ALASKA PENINSULA. 

Atwood 42b in a report on the mineral resources of southwestern Alaska discusses the Jurassic and Cretaceous of the peninsula, stating in regard to the Upper 

Cretaceous: 

Upper Cretaceous sediments are exposed in the mountains northwest of Chignik Bay and 

west of Chignik Lake. They are also present in the Herendeen Bay district. They * * * 

consist of sandstones, shales, conglomerates, a little limestone, seams of bituminous coal, and 

some lignite. Upper Cretaceous fossils were procured by Paige a from the coal measures in the 

Herendeen Bay field and by the present writer from the several other localities above mentioned 

in this district and in the region of Chignik Bay. 

(See also Chapter XIII, p . .574.) 

0 8. SOUTHEASTERN ALASKA. 

See_ Chapter XIV (pp. 632-633). 

0 10-12. NORTHERN BRITISH COLUMBIA AND ALBERTA. 

The northern portion of the great Cretaceous area of the plains has been examined on Liard, Peace, and Athabaska rivers and their tributaries. McConnell 560b 

describes the structural relations in the eastern foothills and out on the plains and 

concludes: 

The Cretaceous section along the Liard shows two great shale and sandstone series separated 

by a heavy band of sandstones and conglomerates. The lower shales, from the imperfect fossil 

evidence at hand and also from their lithologic character, may be referred tentatively to the 

horizon of the Queen Charlotte Islands, or Kootanie formation, the upper shales to that of the 

Benton, while the intervening conglomeratic band probably represents the Dakota. The lithological succession of the Cretaceous beds here is almost identical with that which obtains in 

other parts of the Cordilleran belt north of the international boundary and on the Queen Charlotte Islands and shows that similar conditions of deposition prevailed at the same time over 

this whole area. 

The Cretaceous rocks cross the Liard with a width of over a hundred miles and north of 

the river enter a bay in the mountains, the extent of which to the northwestward is not known; 

southward they are connected with the great Cretaceous basin in the plains. 

South of the Liard the next section examined is that of Peace River, which 

was seen by Selwyn 725 and McConnell. 562 Dawson 253a observed the Cretaceous 

rocks more fully in a parallel section on Pine River, a tributary of the Peace near 

longitude 121° and utilized Selwyn's notes in the following discussion: 

Cretaceous beds in the vicinity of the [Rocky] Mountains appear to be composed almost 

exciusively of sandstones and conglomerates and with little exception maintain this character --------------

a Paige, Sidney, The Herendeen Bay coal field: Bull. U.S. Geol. Survey No. 284, 1906, p. 103. 
UPPER CRETACEOUS. 699 

on the Pine River as far as the Middle Forks. * * * The sandstones are generally brownish 

in color, contain little calcareous matter, and are often quite coarse in grain. They are usually 

regularly bedded, and broad surfaces are freque~tly ripple marked. In the coarser grits and 

conglomerates the constituent fragments are found to be almost entirely of cherty material 

like that occurring in the more resistant of the limestone beds about the summit of the pass. 

* * * From sections exposed in the nearly bare hillsides of Pine River, the thickness of 

the series must be at least 2,000 feet and may be much more. * * * 

While there is no means of arriving at the precise age of most parts of the sandstone series 

of the upper Pine River, I see no reason to doubt that it forms the coarse littoral portion of 

the Cretaceous rocks which spread so widely to the eastward. It seems probable, as more 

fully detailed elsewhere, that fine shaly materials become increasingly abundant in receding 

from the mountains, and that the rocks eventually resolve themselves into the subdivisions 

described below. * * * 

l. Upper sandstones and shales with lignite coals (Wapiti River sandstones). 

2. Upper dark shales (Smoky River shales). 

3. Lower sandstones and shales with lignite and true coals (Dunvegan sandstones). 

4. Lower dark shales (Fort St. John shales). 

The preceding paragraphs refer particularly to the Cretaceous of the eastern 

foothills of the Rocky ·Mountains. The typical development of Cretaceous strata 

in the northern plains of the Athabaska and Peace River region differs from that of 

the foothills. It has been well described by McConnell,S61 a who says: 

The Cretaceous section in the Peace-Athabaska country includes beds ranging in age from 

the Laramie to the Dakota, but the lithological succession of the various divisions differs from 

that which obtains on the Great Plains and also varies in different parts of the district. This 

feature of the formation, together with the further fact that most of the fossils collected are 

new to science and therefore useless for the purpose of correlating the beds here with 

known horizons elsewhere, makes it difficult to classify the different terranes in a satisfactory 

manner and also renders necessary the provisional use of some new names. The following 

illustration shows the succession of the various diYisions of the Cretaceous on the two rivers, 

and also their ages, so far as the stratigraphical and paleontological evidence at hand admits: 

Athabaska River section. 

Laramie. 

Foxhill sandstone. 

La niche shales (upper part). 

Unrepresented. 

LaBiche shales (lower part). 

Pelican sandstone. 

Pelican shale. 

Grand Rapids sandstone. 

Clearwater shale. 

Tar sands. 

Laramie. 

}~Iontana. 

}Colomdo 

Dakota. 

Peace River section. 

\Yapiti River sandstone. 

{

Foxhill sandstone. 

Smoky River shales. 

Dunvegan sandstone. 

{

Fort St. John shales. 

Peace River sandstones. 

Loon River shales. 

Unrepresented. 

For an account of the stratigraphy, with notes on the faunas and correlation, 

McConnell's report should be consulted, but the following summary indicates the 

nature of the formations enumerated in the preceding table: 

The Laramie is an alternation of yellowish and grayish flaggy and massive 

sandstones with grayish and dark clays and shales. It carries thin ironstone bands 

and lignite and is at least 1,000 feet thick in the plateaus south of Lesser Slave 

Lake. No determinable fossils were obtained in it. 

The Montana comprises 50 feet of alternating sandstone and shale (Foxhill) 

and 700 feet of shale, the upper part of the La Biche shales. "The exact junction 

between the Montana and the Colorado was not definitely ascertained, owing to 
700 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

the scarcity of fossils and to the fact that the LaBiche shales pass downward from 

the Montana into the Colorado without any structural break or lithologic change 

of any kind." 

The Smoky River shales of the Peace River section are the equivalents of the 

upper part of the La Biche shales of the Athabaska section. They are dark-grayish 

to bluish-black shales, 200 feet thick, with bands of ironstone. The fossils belong 

to a typical "Pierre and Foxhill fauna." 

The Dunvegan is a littoral formation which is lacking in the east and thickens 

westward from 100 feet on Smoky River to 600 feet at Dunvegan and 2,000 feet at 

Table Mountain, on Peace River. It consists of sandstone and arenaceous shales 

and carries fresh-water, brackish-water, and marine fossils, evidence of estuarine 

conditions and deposition on an oscillating surface. It occupies the stratigraphic 

position of the Belly River series of Assiniboia and Alberta, but the Belly River 

does not contain any marine fossils. The fauna of the Dunvegan is said to be like 

that of the Bear River formation of vVyoming, inasmuch as it contains "two of 

the most characteristic species of the Bear River, Corbula pyriformis and Corb1:cula 

durkeii," but Stanton a does not consider the likeness established by these species. 

The Dunvegan overlies the Colorado, whereas the Bear River underlies it. 

The beds of the Peace River section which are assigned to the Colorado comprise about 1,500 feet of shale and sandstone, constituting three named formations. 

The Fort St. John is 700 feet thick, the Peace River is a lens which thins out eastward, and the Loon River is about 400 feet thick. The Loon River apparently 

rests directly on the Devonian. . . 

In the parallel Athabaska section the corresponding formations that make 

up the Colorado are 930 feet in thickness. Compared with the Peace River section 

the divisions are stratigraphically equivalent as follows: La Biche (lower part)= 

Fort St. John; Pelican sandstone and shale and Grand Rapids sandstone= Peace 

River sandstones; Clearwater shale= Loon River shale. 

McConnell says: 561c 

The Tar sands underlying the Clearwater are assigned to the Dakota on lithologic and 

stratigraphic evidence, as no fossils were found in them. They rest on Devonian limestones 

and occur in the same position as the sands of undoubted Dakota age, which outcrop along the 

eastern edge of the Cretaceous in Manitoba and south of the international boundary in Minnesota. They consist of an almost homogeneous mass of tar-cemented sands, ranging in texture 

from a coarse silt to a grit, and vary in thickness where fully exposed from 140 to 220 feet. 

P 8. LEWES RIVER, YUKON PROVINCE. 

Rocks of Cretaceous age, both igneous and sedimentary, are described by 

Dawson 258 as occurring along the Lewes and other valleys of the inner Coast Ranges. 

He says: 

Besides the Triassic rocks previously referred to, the Mesozoic period is represented also by 

strata of Cretaceous and Laramie age. These rocks are distinctively more recent in appearance 

than and rest quite unconformably on all the older formations, though they have since been to 

some extent involved in their flexures. On the lower part of the Lewes, below the mouth of the 

Little Salmon, these rocks are cut across by the river for a distance of at least 35 miles. Some 

a Personal statement. 
UPPER CRETACEOUS. 701 

fossil mollusks and plants have been obtained from this area, from which it would appear to 

include beds referable to the Middle or Lower Cretaceous a and to the Laramie period, and it 

is not improbable that the series is a consecutive one between these limits, as the total thickness 

represented must be very great. * * * The rocks comprise, in their lower portion, coarse 

conglomerates, graywacke sandstones, yellowish and gray quartzose sandstones, and dark calcareous slates. The upper portion, in which Laramie plants are found, consists chiefly of rather 

soft sandstones, shales, and clays, generally of pale colors. Evidence of contemporaneous 

volcanic action is observable in both parts of the series, and the higher beds include lignite coal 

of good quality. 

Some miles farther up the Lewes, midway between the Little and Big Salmon rivers, peculiar green graywacke sandstones and green, highly calcareous conglomerates occur, which are 

provisionally referred, though with some doubt, to the Cretaceous. They are at least newer 

than the Paleozoic rocks, being composed of fragments of those and of granites.b 

Conglomerates and sandstones similar to the last are again found near the lower end of 

Lake Labarge, on the east side, and are associated with black calcareous slates, which recur in 

several places along the same side of the lake, farther up, and from which a few fossils have been 

obtained. These seem to show that the beds are on or near the horizon of series C, of thfJ Queen 

Charlotte Islands, which is of Middle Cretaceous age, approximately equivalent to the Gault. a 

On the Upper Pelly River, 43 miles below Hoole Canyon, a single low outcrop of hard dark 

shales, containing fossil plants of Cretaceous or Laramie age, was found, but in the absence of 

further exposures along the river in that vicinity nothing can be said of the extent of this area, 

except that it must be quite limited in width. Again, on the Stikine River, between Glenora 

and Telegraph Creek, thete are local occurrences of conglomerates and soft sandstones which 

may be regarded as probably Cretaceous, though no paleontological evidence is forthcoming. b 

The position of these last-noted areas, as well as that of those along the Lewes River, 

occurring as they do in a zone of country immediately within the line of the Coast Ranges, is 

analogous to that held by Cretaceous rocks on the Skeena and in other localities still further 

southward in British Columbia. Further investigation will probably show that the rocks of 

this age occur in many additional places, and occupy somewhat extensive areas in this belt of 

country. In the vicinity of the Lewes, particularly, it is noted that" the plane of the original 

base of the Cretaceous, now thrown into a number of folds, is about that of the present surface 

of the country, and these rocks may therefore be expected to recur frequently in the form of 

troughs or basins,.more or less strictly limited and only to be discovered in detail by thorough 

examination. The loose material brought down by the Big Salmon River appears to indicate the 

existence of a considerable development of these rocks not far up the valley of that stream. 

P-Q 4. LOWER YUKON, ALASKA. 

The large area mapped as Cretaceous on the lower Yukon includes the Nulato 

sandstone, and the strata probably range in age from Lower Cretaceous to upper 

Eocene, according to Brooks, 101r who says: 

Cretaceous rocks outcrop almost without break on the lower Yukon from the mouth of the 

Melozi River to the head of the delta and northward into the basin of the Koyukuk River. In 

this part of the Yukon Valley Dall made the first geologic observations in the interior of Alaska 

over 40 years ago. In his summary of Alaskan geology,C made many years after, he assigned 

some coal-bearing beds to the Kenai (Eocene) ancl reported that they were succeeded by 

marine fossil-bearing sandstone. Spurr d corroborated Dall's observations and, accepting 

Eocene as the age of the underlying coal-bearing beds, assigned the succeeding strata to the 

a In the opinion ofT. W. Stanton these strata are probably of Jurassic age.-B. W. 

bIn the opinion of A. H. Brooks these strata are probably of Kenai (Eocene) age.-B. W. 

c Dall, W. H., and Harris, G. D., Correlation papers-Neocene: Bull. U.S. Geol. Survey No. 84, 1892, pp. 347-348. 

d Eighteenth Ann. Rept. U. S. Geol. Survey, pt. 3. 1898, p. 196. 
702 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

·:uiocene under the name Nulato sandstone. This conclusion seemed to be further supported 

by fossils from sandstone which were determined as :Miocene. The stratigraphic position of the 

coal-bearing beds of the Yukon will be considered below, but it wlll be noted that so-called 

Kenai of the Yukon embraces beds as divergent in age as the Upper Cretaceous and the upper 

Eocene. The stratigraphic work of Collier a in 1902, followed by that of Hollick in 1903 and the 

studies of their collections by Stanton and Knowlton, have yielded ample proof of the Upper 

Cretaceous age of both the Nulato sandstone and the underlying coal-bearing beds. * * * 

Near .Nulato there seems to be exposed a conformable series, consisting of sandstones, shales, 

and conglomerates, which represent continuous sedimentation from the middle of the Cretaceous to the Upper Eocene. 

Schrader's Koyukuk report b makes mention of Lower Cretaceous fossils in an impure 

limestone, associated with volcanic rocks, which outcrop near the sixty-sixth parallel, and to 

the south of these of an impure limestone which carried Upper Cretaceous fossils, but assigned 

the Nulato sandstone to the Miocene. 

Collier 163 gives the following description and tabular arrangement of the Cretaceous and Tertiary of the region : 

The Upper Cretaceous is represented near NuLato by sandstones, conglomerates, and darkcolored shales, which outcrop along the river at intervals for about 100 miles. These have in 

part yielded a marine invertebrate fauna of Upper Cretaceous age, as determined by Stanton. 

Fossil plants were found in the same general horizon and were assigned by Dr. Knowlton to the 

Upper Cretaceous. It is evident, therefore, that these beds include both marine and freshwater deposits. The fresh-water beds carry coals of commercial importance. The Cretaceous 

beds have undergone considerable deformation but are not metamorphosed and, in fact, are 

only slightly indurated. 

The succeeding horizon is made up chiefly of sandstone and conglomerate, with some shale. 

It is called the Kenai series and is of upper Eocene age. These beds usually carry abundant 

plant remains, which show them to be of fresh-water origin. The Kenai series has been named 

from its typical occurrence on Kenai Peninsula and has been identified in various other parts of 

Alaska. It occurs in isolated areas on the Yukon near the boundary and near Rampart and is 

more extensively developed near Nulato. On the upper river it unconformabl;y overlies various 

horizons below the Upper Cretaceous, but near Nulato its relation to the Upper Cretaceous 

seems to be one of conformity. The Kenai beds are, as a rule, little distu.rbed, but in some 

localities they have suffered considerable deformation. The Kenai is the great coal-bearing 

horizon of Alaska. Its coals are usually characterized by the presence of fossil resin, or amber. 

Provisional tabular statement of Yukon stratigraphy . 

I 

.. 

Age. Formation name. Contact relations. Lithologic character. 

Recent ............... Alluvium ........... -------------------- Flood-plain deposits. 

Pleistocene? ......... Yukon silts .... , .... Unconformity ...... Fresh-water silts, sands, and gravels. 

{Twelvemile beds ... } Post-Eocene Tertiary. Palisade conglom- (?) Sands, clays, and gravels. 

erate. 

Upper Eocene ....... Kenai series ....... (?) Fresh-water sandstones, shales, and conglomerates. 

Upper Cretaceous ..... ---·---------------- Conformity? ........ Fresh-water and marine sandstones, shales, arkoses, 

and conglomerates. 

Lower Cretaceous .... ----------·······--- (?) Fresh-water calcareom; sandstones. 

Do ............... -------------------- (?) ~farine black, slaty shales, and thin-bedded limestones. 

Permian .............. -------------------- Unconformity ...... Marine, massive, white limestones, heavy con- glomerates, and gray shales. 

a Bull. U. S. Geol. Survey ~o. 213, 1903. 

b Twenty-first Ann. Rept. U. S. Geol. Survey, pt. 2, 1900, pp. 476-477. 
UPPER CRETACEOUS. 703 

Q 7. UPPER YUKON, ALASKA. 

In 1905 Prindle and Hess 641 reported the occurrence of a Cretaceous sandstone 

in the Rampart region. More recently Prindle 640 has revisited this locality and 

found fossils assigned to the Upper Cretaceous. The rock in which this fauna 

occurs is a black carbonaceous sandy argillite. Granitic rocks cut these beds, showing a later intrusion of acidic rocks than was previously known. The areas are too 

small to show on the map. 

(See also Q 7, Chapter XIV, pp. 635-636.) 

Q 8. NORTHERN YUKON TERRITORY. 

According to Camsell, 128c Peel River, which flows northward from the Rocky 

Mountains in Yukon Territory to the Mackenzie Delta, emerges from a lower canyon, 

cut across folded slates of supposed Devonian age, and thence to a tributary called 

the Snakecuts a deep valley 500 to 700 feet in soft shales and sandstones of Cretaceous age. A section 

of tho bank * * * shows about 300 feet of yellow and red shales, which toward tho base 

are interbedded with layers of sandstone, resting on massive sandstone 50 feet in thickness. 

* * * Farther downstream the banks consist principally of sandstone, with thin beds of 

shale interposed between sandstone beds. In parts the sandstone contains concretions, many 

of which are 10 feet in diameter. Apparently the river in this portion cuts through a low anticline. * * * The Snake River has a deep and narrow valley cut into soft gray argillaceous 

sandstones, which lie horizontally or dip at a low angle to the east. The sandstone is massive, 

but tho beds are separated from each other by thin seams of a harder red-weathering sandstone, 

which contains many fossils of ammonites. * * * South of Snake River is a range o-1' hills 

whose highest points arc 2,000 feet above the river. This range is built up of hard gray sandstone, very similar to the sandstone of the Snake River valley, only a little more indurated and 

approaching a quartzite. 

The fossils.collected in the sandstone of Snake River have been referred by 

Whitea ves to the Cretaceous period. The list of forms is: PanopCBa or Pleuromya ~' 

Thracia, Tellina~, Inoceramus, Desmoceras~ possibly D. affine cf. D. liardense W. 

Q-R 8-10. MACKENZIE BASIN. 

Dawson 257 d refers to Richardson's observations on the lower Mackenzie and 

along the Arctic coast eastward, in accordance with which Cretaceous rocks are 

indicated in this region. McConnell 560c made a reconnaissance of the Mackenzie 

and Porcupine basins, and regarding the area here in question says: 

The plains bordering the lower part of the Liard and the upper part of the :Mackenzie rest 

on Devonian limestones and shales, and the Cretaceous rocks were not detected in descending 

the latter stream until the Dahadinni River, in latitude 64° north, was reached. They consist 

here of a couple of hundred feet of dark-gray shales and sandstones. They are exposed along 

the valley for 10 or 12 miles, and are then concealed by the bowlder clay, but probably 

continue under the latter as far as the Tertiary basin at the mouth of Bear River, a distance 

of 50 miles. The Cretaceous beds here occupy a depression between two high ranges of lime--

stone mountains and can not have a greater width than 10 or 15 miles. They have been separated 

from the Cretaceous beds which form the western shores of Great Bear Lake by the elevation 

of the :Mount Clark range. 

Forty miles below Bear River the Cretaceous beds reappear on the banks of the :Mackenzie, 

and with the exception of one break of a couple of miles where they have been removed by 
704 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

denudation, underlie the valley all the way to the Ramparts, a distance of 90 miles. The fossils obtained both from this area and from the one above Bear River consist of fragments of 

ammonites and Inocerami, too imperfect for specific determination. 

A hundred and twenty miles below the Ramparts the Mackenzie enters a third Cretaceous 

area, and the largest one on the river. Cretaceous beds appear in the banks a short distance 

below old Fort Good Hope and extend down the Mackenzie to the head of its delta and westward across the Rocky Mountains and down the Porcupine to about longitude 139° west. They 

consist on the Mackenzie of coarse shales interstratified with some sandstones and fine-grained 

conglomerates; in the mountains of several thousand feet of barren sandstones and quartzites 

underlain by dark shales; and on the Porcupine of the same two series underlain by a great 

thickness of alternating shales, sandstones, and conglomerates, holding Aucella mosquensis var. 

concentrica. The intermediate dark shales are probably of Benton age, while the lower division, 

so far as the fossil evidence goes, represents the Queen Charlotte Island formation and the Dakota. 

Cretaceous shales holding Aucella and passing upward into fine-grained conglomerates 

occur on the Yukon for many miles above and below the mouth of the Tatonduc and- were 

traced by Ogilvie up the latter stream for some distance. They have been greatly disturbed 

and are folded up in broad bands with the underlying Paleozoic limestones. 

These rocks are described in greater detail by Brooks and Kindle. 103 

The area of Cretaceous west of Great Bear Lake is briefly described by J. 1\L 

Bell. 64 The rocks are shales and sandstones which lie in nearly horizontal attitude. 

On Bear River the strata dip very gently downstream and consist of dark ferruginous and arenaceous shales overlain by thin-bedded and jointed sandstones. No 

fossils were collected and the correlation as Cretaceous depends on stratigraphic 

and lithologic comparison. 

The paleontology of this area is discussed by F. B. Meek.585 

R 5. NORTHERN ALASKA, ARCTIC SLOPE. 

(See Chapter XIV, p. 636.) 

R 22. WEST COAST OF GREENLAND. 

The N ugsoak Peninsula and Disco Island, on the west coast of Greenland, 

present sections of late Lower Cretaceous and of Upper Cretaceous littoral strata. 

The coast of the Cretaceous sea was apparently not far from the present seacoast, 

the more easterly exposures of the sediments carrying plant fossils without marine 

remains and being coarse clastic rocks, whereas the strata farther west are marine 

clays. The latest account of these strata is that given by White and Schuchert, 902 

whose conclusions are in part as follows: 

The Cretaceous and Tertiary rocks in the region described lie everywhere unconformably 

upon a hilly basement of old crystallines, chiefly gneiss and diorite (K:Brsut, Pagtorfik, Ekorfat), 

or upon early Cretaceous or pre-Cretaceous (?) basalts (Niakornat, Alinaitsunguak, Atanikerd 

luk). The greatest altitude of the sedimentary terranes is at Atanikerdluk, 3,400 feet above 

sea leveL The old basalts are highly altered and usually occur as breccias (Niakornat, Alinaitsunguak). 

The prevailing easterly dips of the Lower Cretaceous along the north side of Nugsoak 

Peninsula, in which the strata should dip westerly, since it is in that direction that the higher 

and younger beds appear, may be in part explained by fault compensation, as illustrated at 

Ujarartorsuak. A certain degree of irregularity of dip, the variable and often strong coastward dips as well as the low altitude of the Tertiary at its eastern border on the south side of 
UPPER CRETACEOUS. 705 

the peninsula (Atanikerdluk), are probably due to inequality in the post-Tertiary epmrogemc 

movcrncnis 

The sediments appear to have been derived from the east, since the light-colored sandstones and conglomerates arc most abundant on that side of the sedimentary belt (Kock, 

Kre •sut), where marine fossils appear to he wanting. At one of the eastern localities (Ujarartorsuak) fresh-water shells occur with plants. To the west dark homogeneous shales with 

abundant remains of marine animals predominate. 

Sedimentation appears to have been continuous in some portion of this region throughout 

Cretaceous and early Tertiary times, since no marked unconformities or unmistakable evidence 

of interruption of deposition have been seen. In certain sections, however, there appears to be, 

either in a variable thickness of the series or a slight difference of attitude, evidence of movements or erosion prior to the imposition of the Tertiary basalt cap, though these may be 

only local or of minor extent. But in many well-exposed sections there is no local trace of 

sedimentary cliscontinuity between the Mesozoic and Tertiary. 

The entire thickness of the clastic deposits is probahly over :3,500 feet. They are divided 

by Hecr mto four series, on the basis of their vegetable contents. Of the lowest of these, the 

Kome series, developed on the north coast of the peninsula, a thickness of pr-obably not over 

700 feet is exposed above tide. The discovery of aclditional dlCotyle<lons in the Kome series, 

from which hitherto only Popnlus primxva was known and which was rPgarded as Urgonian in 

age by Heer, casts a serious doubt on the reference of those beds to so low a stage in the 

Lower Cretaceous. The flora as a whole is, however, to he comparecl with that of the Virginian 

Potomac formation, with some, perhaps the upp<'r portion, of whrch the Kome series is probably 

synchronous. 

The Atano series, lutherto not positively known on the north shore of ~ugsuak Peninsula, 

is clearly present at Ujarartorsuak with charactcnstic Atane plants. Farther west, at Kook 

Angnertunek and Niakornat, the dark homogeneous shale series probably represents both the 

Atane and Patoot members of the Upper Cretaceous, since of the marine organisms found hPie 

some are identical with those occurring at Ata and Patoot, the typical localities for the two 

divisions of the Upper Cretaceous. The marine invertebrates from tho Atane series, which 

Heer correlated by means of fossil plants with the Cenomanian of Europe, strongly indicate 

that the series is to be correlated with the Fort Pierre and Fox Hrlls or Montana formation of the 

western United States. Paleobotanically the Atane series is so closely related to the Vineyard 

series of l\Iarthas Vineyard, the Amboy clays of the Raritan region of ~ew Jersey, or the uppermost Potomac of ~\labama as to furnish strong reason for the belief that the middle of Heer's 

groups is the Greenland contPmporary of the Amboy clays. The Patoot series, which appPars 

lithologically and stratigraphically to be inseparable from the Atano series, contains at the same 

time many plants common in the upper part of the Amboy clays, with others allied more closely 

to the higher Cretaceous floras, such as that of the Laramie. The Patoot series may perhaps 

be safely interpreted as constituting a paleontological as well as sedinwntary transition from 

the Atane series to the Tertiar)'· The thickness of the Atane and Patoot series (Senonian) is 

not lPss than 1,300 fppt and may considerably exceed this. 

48011°--12----45 
CHAPTER XVI. 

EARLIER TERTIARY (EOCENE AND OLIGOCENE). 

Color, orange and light orange, in ruling and dots, and orange brown. 

Symbol, 5, 5a, 5b, 5bl, 5c, 5d. 

Distribution: Throughout the Atlantic and Gulf Coastal Plain, Mississippi embayment, Central 

America, the West Indies, Jamaica, Colombia, and along the Pacific coast to Alaska; also 

in the interior western United States and Canada and in Greenland. 

Content: Marine Eocene and Oligocene of Central America, the West Indies, and Pacific coast 

to Alaska (5), including the coal-bearing formations of Puget Sound (Puget group) and 

Alaska (Kenai formation); marine Eocene and Oligocene of the Atlantic and Gulf coast 

plains, the Mississippi embayment, Jamaica, and Greenland (5b and 5d); continental 

Eocene (Puerco, Fort Union, Wasatch, Green River, Bridger, and Uinta formations) of · 

the Interior (5bl); continental Oligocene (White River group, including Chadron and 

Brule formations) of the Great Plains (5c); earliest Tertiary or latest Cretaceous of the 

Interior (Shoshone group, Denver and Arapahoe and equivalents in Colorado; "Upper 

Laramie," Lance formation, and "Cera tops beds" or "Somber beds," in Wyoming, Montana, and the Dakotas), Edmonton of Alberta, ''Upper Laramie" of Canadian reports, 

and in Colombia the Guaduas or Cerro de Oro formation (5a). 

Earlier Tertiary areas. 

Page. 

B JR ......................... Colombia................................................................. 708 

B-C 19 .... __ .................. Venezuela (not mapped) ................................ _._ ........... _... 708 

C 16 ..... __ . _ .................. Nicaragua . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 709 

C 17 .... _. _ .................... Panama (not mapped)............................................. . . . . . . . . 711 

C 20 .. _. _ ....... _ .............. Trinidad (not mapped).................................................... 714 

E 17-18 ...................... Jamaica.................................................................. 717 

E-F 15-16 .................... Chiapas, Guatemala, Tabasco, and Yucatan ............•................ _... 721 

F 17-18 ....................... Cuba ...................................... :.............................. 722 

G-H 14, H-I 15 .... _ ........... Texas, Louisiana, and Arkansas............................................ 723 

G 17, H 16-17, I 15-17, J 16 .... South Atlantic and eastern Gulf Coastal Plain and north end of Mississippi embayment................................................................... 731 

I 17-18, J 18, K 18-19 ... _ ..... North Carolina to Massachusetts, inclusive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 745 

I-J 11. _____ ..... _ ............ Great Basin, Nevada and California .................................... ___ . 750 

J 10. ________ .... _ ............ Sacramento Valley and Coast Ranges, California... . . . . . . . . . . . . . . . . . . . . . . . . . . 751 

J ] 2 _ ~ _______ .. _ ... __ ... __ .... Plateau province of Utah.. . . . . . . .. . . . . . . . . . . . . . .. . . . . .. .. . .. . . . .. . . . . . . .. . 755 

J 12-13 ............ _ .... ___ .... SanJuan Basin, Colorado and New Mexico.................................. 755 

J 13 ...... ___ ... _ ... __ ... _ .... Great Plains of Colorado; east-central Colorado (not mapped)................. 757 

J-K 12-13 .... __ .. __ ... _. __ ... Uinta Valley, Roan or Book Plateau, and Grand Mesa....................... 759 

J-K 13, L 13-14 ... ___ ......... Great Plains of Colorado, ·wyoming, Montana, North and South Dakota....... 761 

K 10 .. _ ... _ ... __ ... __ ........ Rogue River valley, Oregon............................................... 764 

K 12. ___ .... _ ... __ ... ___ ..... Northeastern Utah and southwestern Wyoming; Wind River Basin, Wyoming. 765 

K 13 .... __ ... _ ... __ .......... ·wyoming and Colorado . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . 766 

K 13-14 ... ___ .. ___ .... ___ ·_ ... Great Plains of South Dakota, Wyoming, Colorado, and Nebraska............. 769 

K-L 10 .. __ ........ ___ ........ Coast Range of Oregon.................................................... 771 

L 10 ....... _ ... _. _ .... ____ .... John Day Basin, Oregon; Cascade Range and Yakima Valley, Washington ... _ 772 

L 12 .... _ .... _ ..... _ .......... Bighorn Basin, ·wyoming; western Montana; Bull Mountain coal field, Montana; 

Red Lodge coal field, Montana........................................... 774 

L 13 .............. __ .......... Plains east of the Bighorn Mountains, \Y yoming; Miles City coal field, Mon 1 ana; 

Sentinel Butte coal field, North Dakota and Montana ....••.. :............. 777 

L--M 10 .............. __ ....... Olympic Peninsula and Puget Sound region, Washington.................... 778 

M 10 ................. _____ ... Southern British Columbia (not mapped)................................... 780 

M-N 11-12 .................... Great Plains, Alberta..................................................... 781 

706 
FIGURE 18.-Sketch map showing the distribution of earlier Tertiary rocks represented on the geologic map of North 

America and the key to references in the text. .Eocene and Oligocene mapped separately where their extent is 

known. 

707 
708 INDEX TO THE STRATIGRAPHY OF NORTH AM:ERICA. 

Pag-e. 

~ 4 ........................... Chichagof Cove, Alaska Peninsula.......................................... 782 

N 4, 0 4-5 .............. _ .. __ .Alaska Peninsula (mapped in part) ..................... _ .... _ ..... _...... 783 

0 5 ___ .................. __ .. ·.Kodiak Island and Katmai Bay .......... ___ .. _ ..... _._ .... _ .... _ ...... __ .. 784 

0 8. __ ....... _ .... _ ..... _ ... _Southeastern Alaska (not mapped) ....... __ .......... . . . . . . . . . . . . . . . . . . . . . . 784 

0 10. __ ... _ .............. _ ... Finlay and Omenica rivers, British Columbia ... _ ....................... __ .. 785 

0-P 5 _ ........... _ .. _ .. _ . ____ Kenai Peninsula .. _ .. ___ .... _ ................ ___ .. _ ...... _ .. __ . _ .. _ .. _ .. __ 785 

P 3 ............... _ ........... Nunivak Island and Yukon Delta ........ ______ .. · ........ _ .. _ ... _ .. __ . ___ .. 7S7 

P 5 ................. _ .. _ .... _.Cook Inlet near Tyonek ..................... __ .... _. __ .. _ .. ___ . __ .. _____ .. 787 

P 6 .................. _. ____ . _ .1\Iatanuska Valley .. __ ................................. _ ........... _____ ... 788 

P G-7 __ ... _ ........... _ ....... Controller Bay to Cape Yakataga (mapped with later Tertiary); 1\[ount\Yrangell 

district, Alaska (not mapped) ....................... _ ........ _ .... _. _.... 788 

P-Q 5-G ........ _. _ .. _ .... _ ... Foothills of the Alaska Range (not mapped) ...... _._ ........ _ .. _ ... ___ ...... 790 

Q 3. __ ....................... Seward Peninsula (not mapped).. .......... __ .. _ .... _ ....... __ . __ ....... ___ 791 

Q 3-4. __ ....... _. _. __ .. _ ..... Norton Sound, Alaska (not mapped) ..... __ ................. _ ...... _ ..... __ 791 

Q 4-5 __ . __ . _ ... _. __ . __ . __ . ___ Kobuk River ............................ _._._.... . . . . . . . . . . . . . . . . . . . . . . . 791 

Q 5-G ................ _ ... _._.Yukon Valley (not mapped) ................. __ ..... _...................... 792 

Q 7 ................ __ . ____ . __ Upper Yukon ................................ _ . ___ .......... _ . . . . . . . . . . . . . 792 

R 5-6 .. __ ..................... Arctic coastal plain (mapped with later Tertiary) ..... _ .... _._ .............. _ 792 

R 26-27 ....... __ .. _ ..... _ ..... Northeast coast of Greenland (not mapped) .................... _ ..... ___ ... _ 793 

B 18. COLOMBIA. 

A formation which has been assigned with doubt to the Cretaceous or Tertiary 

is described by Hettner 437 a as the Guadu:is formation of the Cordillera of Bogota. 

This was recognized by Sievers in the Cordillera de Merida in Venezuela and there 

entitled the Cerro de Oro series. It consists of bright-colored, especially red, 

yellow, or violet clays that contain particles of brown iron ore and interbedded 

layers of coarse sandstone which is mostly red or dirty white and which in places 

becomes conglomeratic. The lower portion of this formation or the upper part of 

the underlying Guadalupe (Upper Cretaceous) belongs to the coal-bearing strata 

of Colombia. No other fossils than imperfect remains of plants have been found 

with the coaL Karsten was of the opinion that this formation was unconformable 

upon the Guadalupe and therefore considered it to be Tertiary. Hettner, however, 

regards the unconformity as apparent rather than real, and as he could not find 

any sharp boundary between the two divisions, he doubted the Tertiary age of the 

Guaduas formation, thinking 'it more likely Cretaceous. 

B-C 19. VENEZUELA. 

Sievers, 741 b in describing the Cordillera de Merida, places provisionally in the 

early Tertiary a division which he calls the Cerro de Oro terrane. He says: 

In Tachira, as well as elsewhere in various places in the Cordillera, massive deposits of very 

varied constitution lie above the limestone of Albien age. In various places one may observe 

coal beds occurring between shaly calcareous and sandy formations, and in two places petroleum 

occurs in these deposits. It is probable that the thickness varies from place to place and that 

it may often be impossible to establish a particular sequence of strata, especially as the formation has undergone great tectonic disturbance. However, I had the good fortune to discover 

at least in one place a thickness of 800 meters in which the relations of this formation were 

clearly presented. 

The section as measured by Sievers and given in great detail shows an alternation of thin sandstone, shale, and carbonaceous layers and is compared with the 

Caroni series of Wall in the Island of Trinidad. Sulphur occurs as a characteristic 

constituent of many of the s:1ndstones. 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 709 

Regarding the age of the formation, Sievers has no definite data, as he found 

no fossils. The Caroni series of Wall was placed in the Miocene on fossil evidence, 

and Sievers regards the Cerro de Oro terrane as probably equivalent to it~ On the 

other hand, he is not sure that it should be separated from the Cretaceous, and in 

the absence of fossils its age remains undetermined. 

C 16. NICARAGUA. 

Hayes 427 states that the Tertiary rocks along the line of the proposed Nicaragua. 

Canal are the oldest certainly known in that section and comprise two formations. 

the Brito and Machuca. 

The [Brito] formation presents considerable variety in its lithological composition, hut it 

has not yet been sufficiently studi~d to permit of its subdivision, even if this may be eventually 

possible. Much the larger mass of the formation consists of somewhat calcareous nonfissile' 

shale. When fresh this is bluish gray and weathers to a yellowish or brownish color. Distributed through the shale are numerous beds of sandstone. These are also somewhat calcareous and doubtless contain a considerable proportion of volcanic ash. The sandstone beds 

vary in thickness from a few inches to 2 or 3 feet and occur singly or in groups. * * * These 

sandstones, like the shales, are blue when entirely fresh but arc always weathered at the surface 

to some shade of yellow or brown. * * * They occur most abundantly near the Pacific 

coast and are well exposed in the headland northwest of the Rio Grande Valley at Brito. Tho 

beds here have a general though somewhat variable dip to tho southwest, hence the higher 

portions of the formation make the cliffs along the Pacific. This seems also to be its most 

variable portion. In addition to the shales, which constitute its greatest bulk to the eastward, 

it here contains also beds of sandstone, conglomerate, and coarse breccia on tho one hand, and 

on tho other marly beds and lenses of pure limestone. Forming a part of the headland south 

of Brito is a bed of limestone something over a hundred feet in thickness. Small outcrops of 

this bed, or one very similar, have been noted at several other localities to the eastward in 

the Divide Hills. Its limited extent is due in part to erosion, since the dip of the bed would 

carry it above the tops of most of the hills to tho eastward, but it is doubtful if its original 

extension was very great. Several of the limestone outcrops noted are probably small lenses 

in the shale and not connected with the more continuous bed at Brito. A portion of this limestone has a peculiar concretionary structure, some of the concretions attaining a diameter of an 

inch and a half, while other portions of the bed are oolitic. Immediately west of this exposure 

of limestone, forming a group of islets nearly covered by high tide, is a very coarse volcanic 

conglomerate or breccia. The larger fragments are a foot or more in diameter and quite angular, 

and from this extreme they grade downward to small pebbles, some of which are well rounded. 

The present relations indicate that the conglomerate is the stratigraphical equivalent of the 

limestone, replacing it within a few yards. In some places the two rocks are seen to merge, the 

limestone containing numerous angular fragments of volcanic rock. At other points along the 

coast both north and south of Brito, similar conglomerates occur. Their bedding is extremely 

irregular, and they afford evidence of having been formed rapidly and near tho source from which 

their constituents were derived. While it is possible that the source of this material may have 

been to the eastward, it seems much more likely that it came from volcanic vents to the southwest, from volcanoes '>vhieh have been entirely removed by the waves of the Pacific. * * * 

The exposures of the Brito formation arc so infrequent and the dips are so variable that 

no satiHfaetory measure of the thickness of the formation can be obtained. Taking the observed 

dips between the Pacific coast and the lake shore the thickness exposed is estimated at about 

10,000 feet. This of course is not the total thickness of the formation, since the bottom is not 

exposed at the axis of the anticline. Also the formation has undoubtedly suffered an unknown 

but considerable diminution in thickness by erosion, and there are no data for determining the 

thickness of strata which have been removed from the highest beds now observed. * * * 
710 INDEX TO THE STRATIGRAPHY OF NORTH A..l\fERICAo 

The greater part of the Brito formation is apparently barren of organic remains. The 

only locations at which fossils have been found are on or near the Pacific coast. This, however, 

may be due to the fact that the rock exposures are not elsewhere of such a character as to facilitate the discovery of fossils, and the latter may possibly be more generally distributed than 

present knowledge would indicate. The fossils are confined almost wholly to the limestones 

and marly beds. They consist of corals, molluscans and foraminiferal remains. The latter 

are especially abundant. The rather meager collections have been submitted to Dr. Dall for 

determination. He pronounces them Oligocene and probably identical with the foraminiferal 

beds described by Hill from the Caribbean coast at Panama. One of the most abundant 

forms is a small nummulite, Orbitoides, probably forbesei, which is characteristic of the lower 

Oligocene. The molluscan remains were collected on the Pacific coast about 75 miles northwest of Brito in what was supposed to be a higher portion of the same formation. Dr. Dall 

states that these have the upper Oligocene aspect, though there are not enough of them to 

be conclusive. He thus confirms the view entertained in the field that successively higher beds 

in the Brito formation are exposed along the coast toward the northwest. 

In addition to the fossils on which is based the above conclusion concerning the age of the 

Brito formation, it also contains rather abundant plant remains. They are in the form of 

driftwood and coal, and as yet no remains sufficiently well preserved for identification have been 

discovered. Associated with the coarser sandstones are numerous blocks of wood, whose 

rounded forms suggest that they are fragments of drift which were incorporated with the sand 

and gravel while it was accumulating. In some cases they still contain a large proportion of 

their original carbon, and in others this has been more or less perfectly replaced by silica or 

iron pyrites. The coal occurs associated with the finer sediments, and although a careful search 

was made, the thickest seam observed was under half an inch. VVhile sufficient carbonaceous 

matter is sometimes disseminated through the shales to give them a black color, no indications 

were found pointing to the existence of workable coal deposits in the region examined. 

Coal in workable quantity has been reported from the region southwest of the lake, 

between the lake shore and the Costa Rican volcanoes. The exact locality is on the Rio 

Hacienda, 12 miles from its mouth. It was not visited and no samples of the coal were seen, so 

that the report lacks verification. There appears to be no reason, however, why conditions 

favorable for coal accumulation should not have prevailed in some portions of this region during 

the deposition of the Brito beds. * * * 

[The Machuca formation] appears to consist chiefly of calcareous shales with which sandstones arc interbedded. The constituents of the rocks are largely igneous in their origin, but 

there are no coarse conglomerates or breccias such as occur in the Brito. Also no pure limestones or distinctly marly beds have been discovered, although the examination. of the formation 

has not been sufficiently exhaustive to enable one to say that such beds do not occur. * * * 

No fossils have as yet been found in the Machuca formation which are sufficiently well preserved for specific determination. At Cruzita, 1 mile below Machuca, the core from the diamonddrill hole in the bed of the river contains numerous indistinct organic forms. The rock is 

described by Dr. Ransome as an andesitic tuff containing fragments of limestone. The organic 

forms are revealed by the weathering of the rock with the removal of the soluble limestone, 

and they are also shown in the thin section under the microscope. VVhile they can not be 

identified, they strongly suggest the forms which occur so abundantly in portions of the Brito 

formation. The beds in which they occur are evidently derived in large part from fresh volcanic 

tuff, though the latter was not so abundant as to prevent the growth of organisms in the sea in 

which it was being deposited. In the absence of conclusive fossil evidence, therefore, the age 

of the Machuca formation, so far as it may be determined, rests upon other and less satisfactory 

evidence. It is believed to be nearly or quite contemporaneous with the Brito formationthat is, Oligocene (Tertiary). The grounds on which this conclusion is based are briefly as 

follows: (1) There is a general similarity in lithologic composition and appearance between the 

two formations. (2) Both have suffered about the same amount of deformation, elevation, 

and erosion since they were deposited. The value of this fact for correlation depends upon the 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 711 

proximity of the areas which they occupy and the evidence that the recent geologic conditions 

have been similar in both. (3) Both formations bear about the same relation to a group of 

igneous rocks which was in part contemporary with them and in part subsequently invaded 

their beds. The differences in composition of these intrusive rocks are not greater than differences in igneous rocks within the same area which are known to be nearly or quite contemporaneous. (4) Finally, as pointed out above, it is possible and even probable that the two formations are nearly or quite continuous through the southern part of the upper San Juan Valley. 

C 17. PANAMA. 

Howe 465 states, in a report on the geology of the Canal Zone: 

The central portion of the isthmus along the canal line consists of rocks of igneous origin. 

They are the oldest rocks of the region and have been observed at the surface in the central 

area, between Mamei and Empire and northeast of the city of Panama. Diamond-drill borings 

have indicated their presence also at other points, and it is believed that they underlie at greater 

or less depth the whole territory included in the Canal Zone. 

To the northwest younger rocks of sedimentary origin occur, resting on the older igneous 

mass and gently inclined toward the Caribbean Sea, so that in passing from the interior toward 

Colon successively younger beds are encountered. Their well-defined stratification and the 

abundant fossil remains of marine organisms indicate that these rocks were formed by the 

deposition of gravel, sand, and mud on the sea bottom, or in tidal estuaries where the materials gradually hardened into rock. Nearly the same conditions prevail on the Pacific side, 

where, in addition to the older igneous and sedimentary rocks, younger igneous rocks occur. 

Dikes and large crosscutting masses of a basaltic nature have invaded all of the older 

sedimentary rocks; they occur in greatest abundance in the central and southern parts of the 

Zone and are believed to represent the last phase of active volcanism in the neighborhood. 

From its very characteristic occurrence in the vicinity of Obispo, this name has been given 

to the formation about to be described that occupies a large part of the central region and 

consists of andesitic breccias and associated lava flows. * * * 

The Obispo breccias, which are believed to constitute a large part of the formation, are 

of variable texture, usually being composed of angular fragments an inch or more in diameter. 

No evidence was found that they were laid down or sorted by the action of running water. 

The fragments consist of andesite of a variety of textures and show slight differences in composition. The majority of the fragments appear to consist of pyroxene andesite, although a 

fair percentage of hornblende andesites are present. The color of the breccia on fresh exposures 

is a dark blue or green. The rock near the surface has been altered to a red clay. 

At a few places, notably in the vicinity of Empire, lava flows of massive andesite were 

found associated with the breccias. The actual relation of the flows to the breccias is not 

clearly shown, but it is believed that they were contemporaneous and that quiet outpourings 

of lava alternated with the explosive eruptions that produced the breccias. The massive rock 

is of essentially the same composition as that composing many of the fragments in the breccias, 

but in most cases is too far decomposed to admit of exact determinations. * * * 

Judging from the extremely unconformable relations that exist between the Obispo formation and the younger rocks, it seems clear that following the eruption of the breccias the region 

was thoroughly dissected by the erosive action of streams. The interval between the close 

of the andesitic eruptions and the beginning of the next recorded epoch was of unknown extent, 

and the original surfaces of the Obispo rocks were completely obliterated before the next succeeding formation-the Bohio-was deposited. * * * 

Probably the oldest sedimentary formation represented in the Zone is that which has 

its most characteristic outcrops in the vicinity of Bohio. • 

Near the railroad station is a cliff, from which building stone has been quarried and which 

rises 50 feet or so from the level of the flat on which the town is built. The rock here is of 

a very even texture and at first glance strongly suggests a fine-grained volcanic breceia. It 
712 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

is of a peculiar brownish color, unlike that of the Obispo breccia; the fragments are apparently 

angular and usually less than 1 inch in diameter. One of the most striking features of this 

rock, shown in deep ·borings as well as at surface outcrops, is its alteration; it mashes under a 

blow of the hammer and yet has not the appearance of being greatly decomposed, except at 

or very near the surface. The alteration seems to have been to serpentine or some related 

mineral instead of kaolin, as is usually the case with the other rocks, especially those of the 

Obispo formation. 

Across the river, at the old lock site south of Bohio and east of Pena Blanca, quite a 

diJ'Terent phase of this formation is exposed; it consists of alternating layers of sandstones and 

coarse conglomerates all clearly water transported and deposited. .Many of the bowlders 

are a foot or more in diameter; they are of andesites for the most part, but not a few are of a 

lighter-colored porphyritic rock with abundant hornblende crystals. The finer layers and 

the cementing material are very like the rock occurring at the Bohio quarries. Cross-bedding is 

common and fine material often occurs in lenses in the grits and conglomerates. The prevailing 

strike is N. 25° E., and the dip to the northwest at an angle of about 14°. 

The identity of these conglomerates and the more even-textured breccia-like rock is not at 

all evident in the field, but many borings made in the vicinity show a gradual transition southward from the even-textured breccias of Bohio to the conglomeratic facies at Pena Blanca. 

The boring made at kilometer 24 (hole 24-b) is of interest, since it shows carbonaceous 

sandstones in the middle part and fossils in the lower part of the core. 

Further study of this formation to the southeast and by means of borings has shown that 

it is of variable character, in some places clearly sedimentary and water sorted, both fine grained 

and conglomeratic; in other places the appearance is more that of a volcanic breccia, possibly 

water-laid but not water transported. * * * 

In general the formation may be described as a probable fluviatile deposit characterized 

by sudden changes and transitions, the composition of the materials being fairly uniform. 

It is not improbable that volcanic eruptions may have been taking place during the period 

in which the formation was deposited and the material forming the breccia-like portion attributed 

directly to such a source. 

The fossils previously referred to that were found in the core taken from hole 24-b occur 

at elevations of from 30 to 40 feet below sea level. They include, in addition to vegetable 

matter, certain fossils indicating probable Eocene age. At about 2 miles to the west, at a locality 

known as Vamos Vamos, on the left bank of the French canal, are outcrops of a limy shale 

with large calcareous concretions resembling bowlders in a conglomerate; both the shale and 

concretions contain numerous fossils which Dr. William H. Dall regards as of undoubted Eocene 

age. Outcrops of similar rock containing the same fossils occur about 6 miles to the northwest 

on the left bank of the canal in the vicinity of Gatun. 

The rocks at Vamos Vamos and in the vieinity of Gatun are finer grained than those of the 

Bohio formation and consist of shales and fine sandstones. 

The fossil evidence shows with certainty that the beds near Gatun and at Vamos Vamos 

and Bohio are of the same age, and it is believed that they are to be regarded strictly as part 

of one formation, the occurrence at Bohio representing a littoral facies, while those farther 

to the northwest were deposited in deeper water. 

In the excavations made by the French between Bohio and Pena Blanca, and also at the 

base of a little hill at the west end of the village of Bohio, there are outcrops of a white calcareous 

sandstone or marl containing some volcanic material in the form of crystals of feldspar and 

fine specks of a ferromagnesian mineral. In places it is extremely rich in the remains of Foraminifera, especially Orbitoides Jortisi, and may seem to consist altogether of the shells of these 

minute organisms. * * * 

The Foraminifera of• the Pena Blanca rocks, and especially the species Orbitoides jortisi, 

are characteristic of the Lower Oligocene. From their position between two well-determined 

occurrences of Eocene rocks it is believed that they are clearly younger than the Bohio formation and rest upon these rocks unconformably. 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 713 

Directly above a conglomerate that occurs near the railroad station at Gatun is a brownish 

impure calcareous clay or argillaceous sandstone, apparently containing much debris of volcanic 

rocks and numerous fragments of shells. Many perfect fossils are to be found, but the extremely 

crumbling nature of the rock makes it almost impossible to obtain good specimens. Such 

as were collected have been determined by Dr. Dall as of probable Oligocene age and newer 

than the foraminiferal beds of Perra Blanca, and the rocks are to be regarded as near the 

base of the succeeding Oligocene formations that occur at numerous places between Gatun 

and the bay, notably at the Mindi Hills and at the Monkey Hills. 

The conglomerate under these sandstones contains many fossils that are the same as those 

of the Bohio and Vamos Vamos beds, but it is believed that the conglomerate represents the 

base of the Gatun formation and that the Eocene fossils present were derived from the older 

rocks and so do not indicate the true age of the conglomerate. 

Soft sandstones of a dirty greenish-gray color, derived from igneous rocks with a calcareous 

and clayey cement, are the most abundant rocks of the Gatun formation. Associated with 

them are shales, impure marls, greensands, and, at certain horizons, fine white tuffs composed 

of pumice, probably of the composition of a rhyolite. * * * The rocks are all well consolidated, though in a few rare cases sandy layers are found which crumble on exposure to the 

air. These arc the beds that have been referred to frequently as "indurated clays." The 

term is a misleading one, since true clays make up but a small part of the formation. Induration is a term applied to the process by which sandstones or argillaceous rocks are converted 

into quartzites or slates by heat or mineralized solutions accompanying the intrusion of igneous 

rocks. None of these conditions existed in the vicinity of Gatun. The rocks are of sedimentary 

origin and were deposited on the sea bottom at some distance from the shore in the form of 

sands and clays. Their subsequent hardening into rock is the result of simple cementation by 

calcareous solutions contained in the sea water alfd through pressure. Certain beds are harder 

than others, since the nature of their constituents favored more complete consolidation. The 

beds, however, are not to be regarded as unconsolidated. They are all "rock," though in some 

instances soft enough to be loosened with a pick. 

These beds extend northward with little change in lithologic character to the Monkey 

Hills in the vicinity of Colon. Fossils collected in the more northerly localities indicate that 

the beds in this region are still younger than those at Gatun. No sharp breaks have been 

observed, however, and it is believed that practically continuous sedimentation took place 

from the time the Gatun beds were deposited until the close of later sedimentation. 

The rocks belonging to the Culebra formation have been exposed by excavation from 

Las Cascadas to Pedro Miguel along the line of the canal, the best exposures being in the vicinity 

of Culebra. 

The formation consists of a series of soft shales, with sandy, conglomeratic, and calcareous 

layers abundant. Limestones, as at Empire, Las Cascadas, and in the railroad cut between 

these two places, are also indicated at several points by borings. Of these the occurrences at 

Empire (Camacho) are undoubtedly the most massive, the others being present apparently as 

lenses in the shales and sandstones. Although some thick beds of very homogeneous pure 

clay shales occur, most of the formation is richly carbonaceous, and at a number of places in 

the _cut lcnslike seams of lignite have been found and remains of trees and plants are abundant. 

The age of the Culebra formation can not be frx-ed with absolute certainty. Fossils collected at a number of points between Las Cascadas and Pedro Miguel were not sufficiently 

characteristic to determine the age of the beds, but at the lock site at Pedro Miguel collections 

were made at two points less than 100 yards apart that supply more definite information. The 

fossils from the more northerly point, 30 feet vertically above the other horizon, are regarded 

by Dall as representing the Oligocene, probably a reef deposit. The material from the lower 

and more southerly locality is pronounced Eocene by Dall. From the prevailing southerly 

dip of the beds in the region the fossils from the two localities were believed in the field to belong 

to the ~arne horizon. The lack of continuous outcrops, however, makes it impossible to assert 

positively that this is so. The only fossils collected by Hill from the Culebra formation came 
714 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

from the Empire limestone. Only the foraminiferal portion seems to have been determined, 

and these are regarded by Bagg as probably Eocene. The fossiliferous beds near Pedro Miguel 

are undoubtedly at or very near the top of the formation, since the dip carries them below 

the surface a short distance to the south, and borings at kilometer 59, slightly to the north, 

show the usual Culebra formation extending to an unknown depth below. The Eocene and 

Oligocene ages of the beds at the two localities at Pedro Miguel seem certain. In any event 

there can be little doubt of the Eocene age of the Culebra formation as a whole and its probable 

correlation with the Bohio and Vamos Vamos beds. The occurrence of an Oligocene fauna 

directly above the characteristic Eocene at Pedro Miguel is comparable to the sudden change 

that takes place at Gatun from the Eocene of the Vamos Vamos beds to the Oligocene of the 

Gatun formation. 

The thickness of the Culebra formation has been variously estimated at from 400 to 500 

feet. A boring made at kilometer 55 of the canal (hole 31) extends 40 feet below sea level, 

starting at 167 feet above the sea; 207 feet of Culebra beds are here indicated, while possibly 

17 5 feet might be added as representing the part already excavated at the cut, giving a thickness 

of nearly 400 feet, with the bottom not yet shown. 

C 20. TRINIDAD. 

Wall ;tnd Sawkins 863b distinguished the Newer· Parian group m Trinidad as 

Tertiary and recognized five divisions. They say: 

The ~ewer Parian group comprises a considerable succession of limestones, calcareous 

sands, shales, loose ferruginous sands, conglomerates, clays, and marls, which seem sufficiently 

related to one another by fossiliferous contents to form one group, of which the organic remains 

present a certain analogy with the Miocene fauna. 

For distinct classification, five divisions or series are admitted, in naming which the same 

principle of locality already employed, and so convenient in provisional nomenclature, will be 

again. adopted. These divisions areA. The :Nariva series. 

B. The Naparima marl. 

C. The Tamana or calcareous series. 

D. The Caroni or carbonaceous series. 

E. The Moruga or arenaceous series. 

The Nariva series consists of clays, with shales and extremely rare yellowish limestones, 

and forms the substrata to the well-known red soils. * * * The strata are traversed by 

bands of highly ferruginous matter parallel with the stratification. 

The geological importance of these beds is very subordinate; they possess, probably, but a 

slight thickness and seem to constitute merely the inferior portion of the following division. 

Their relations to the Older Parian group were not ascertained, and generally, from the absence 

of proper sections, but little information has been obtained respecting this series. * * * 

The Naparima marl includes a series of strata composed of marls, conglomerates, and 

calcareous sand. 

The mineral matter of these marls is in a state of fine division apd varies from a basis of 

clay, with 10 to 50 per cent of carbonate of lime, to a basis of siliceous substance, consisting 

of the shields of Infusorire, and an average content of 20 per cent carbonate of lime. The 

clay marl contains sometimes a much smaller proportion of Infusorire. 

There is generally a small proportion of carbonate of magnesia, and in some cases even 

30 per cent, almost sufficient to combine with the carbonate of lime to form true dolomite. 

* * * These strata have usually a highly conchoidal fracture, especially the more argillaceous marls. 

The conglomerates are formed of rounded pebbles of indurated sandstone, and varieties of 

jasper from the Older Parian, with cement. They do not exceed 8 or 10 feet thick and are 

sometimes bounded by sands containing shelly fragments and a variety of calcareous matter. 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 715 

Limestones occur interstratified in the marl, in rather thin beds, and of oolitic or 

even subcrystalline texture. Corals are of common occurrence, especially a species of 

Orbicella. * * * 

The Tamana calcareous series consists of the massive limestone of Tamana, L'Ebranche, 

and ::\fontserrat, which varies from white to yellow in color and from granular to crystalline in 

texture. These strata have experienced a very complete change of structure, the particles 

being entirely rearranged, which is most beautifully exemplified in the obliteration of the fossil 

corals, whose exterior surfaces are well preserved, but toward the interior all organized texture 

gradually fades into the crystalline mass. 

This is the most definite stratum of the whole island, and can be traced, .with only two 

or three interruptions, from near the western to the eastern coasts. There is only one common 

coral (a species of Orbicella) which also occurs in the limestones of the ·Naparima marl. The 

stratification being usually obliterated, the dip can be but rarely determined and is always found 

to be to the northwest, at an angle varying from 30° to 70°. The thickness can not be less 

than several hundred feet. 

The beds of conglomerate are composed partly of rounded pebbles of indurated sandstone 

and jasperized clays from the Older Parian, and partly of quartzose detrital froin the northern 

hills (Caribbean group). The cementing matter is ferruginous, calcareous, or siliceous. These 

conglomerates are generally highly consolidated. 

Calcareous sand and sandstone form a marked feature in this succession of strata. The 

former are loose, with a certain, usually small admixture of calcareous, often shelly matter, and 

occasionally traversed by layers of hard calcareous sandstone. The latter consist of grains of 

sand, with calcareous cement, which is frequently fine organic debris or larger shelly fragmEmts, 

and form hard beds of a few inches to 20 or 30 feet in thickness. Both these varieties of strata 

contain abundance of marine shells and have supplied the larger proportion of the animal 

fossils collected in the island. • 

The remaining strata of the series consist of sands and clays, more or less fossiliferous, but 

not consolidated. 

The sequence of strata is exposed in the cliffs at Manzanilla. The thickness, including the 

crystalline limestone, may be about 2,000 feet. * * * 

The crystalline limestone seems to form one of the lowest members, over which are calcareous sandstones, conglomerates, and calcareous sand, above which are fossiliferous clays and 

sands. * * * 

The Caroni or carbonaceous series is exposed in a complete section in the cliffs between 

Manzanilla and the Oropuche. Two divisions may be introduced-the lower or noncarbonaceous and the upper or carbonaceous. The former consists of shales, generally dark gray; 

dark, often black fossiliferous clays; a few thin beds of sand, frequently sulphurous, and associated with a small number of pebbles from the Caribbean and Older Parian groups; and in the 

upper part of highly laminated but unfossiliferous hard calcareous sandstone. The superior 

division contains strata composed of sand, with small pebbles of the usual varieties, shelly 

fragments, and calcareous cementing matter. The rock of Point Noir is an illustration of this. 

Of shales there are all varieties, from light-colored to dark carbonaceous. The clays are 

frequently carbonaceous and sulphurous. 

Beds of massive yellow but pulverulent sand generally overlie the larger seams of coal, with 

only a few feet of shale intervening. 

Subordinate layers of calcareous sandstone, usually only a few inches thick, occur in places. 

The seams of Tertiary coal associated with the preceding strata form an important item. They 

are numerous and vary from a mere carbonaceous film to over 4t feet in thickness. * * * 

The lower strata of the upper division contains shells similar to those at Manzanilla, but 

the superior beds are characterized by large shells, which are believed to be confined to that 

portion of the series. A few dicotyledonous leaves occur in the nodules of calcareous sand or 

day. * * * 
716 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The Moruga or arenaceous series is an extensive series of strata, usually of a loose sandy 

nature. These are well exposed in cliffs all along the southern shore and offer some characteristics quite" peculiar to themselves and others which are possessed in common with the Caroni 

division. Thick strata of massive sand, generally loose and pulverulent, are the most prevalent beds, and, indeed, sand may be said to be in great excess. Granular sulphur is very generally disseminated in these strata, having been observed from Canary round Point Icaque to 

Oropuche. Shales are also numerous, but clays of rarer occurrence. 

Calcareous sandstone is extensively diffused in beds not exceeding 6 to 8 feet thick, and 

often only a few inches, and, being very hard, resists the destructive action of the sea, running 

out in parallel lines on the beach often beyond low water, and forming quite a characteristic 

feature of this line of coast. The cementing calcareous matter seems to have been comminuted 

organic detritus, but in some cases the original nature of the deposit was fossiliferous sand, 

the indistinct impressions of the shells remaining, but their calcareous substance being entirely 

removed and reprecipitated as cementing matter round the grains of sand, thus binding the 

whole into one compact mass. * * * 

Layers of carbonaceous matter occur, but by no means so commonly as in tho Caroni series. 

The vegetable structure is usually very distinct, but occasionally obliterated. The principal 

seam of lignitic shale is near Point .Yioruga. It occupies a vertical position and is 20 feet wide, 

containing several layers of lignite not exceeding 10 inches but much inclined to be bunchy. 

These carboniferous beds are all more or less mixed with shaly matter, rE)ndering them impure. 

At Erin and Irois the beds of lignite are less inclinded and the ligneous texture still more 

apparent. 

Strata which will be named porcellanite occur especially at Erin, Points Cedros and Rouge, 

part of Point Brea, to a small extent at Moruga, and adjacent to the large seam of coal at Punta 

Paloma (Caroni series). By the above term it is intended to imply strata of semi to perfectly 

indurated and compact structure, presenting a great variety of "colors, among which brick-red 

is predominant. They are fissured and jointed into almost cubical masses, these joints being 

frequently lined with vesicular slag. An alternation of colors in thin laminre frequently prevails. 

Some specimens are semivitrified, forming porcelain jaspers, and the fracture is frequently 

conchoidal. 

The peculiarities of these strata are most fully developed in the central portion, diminishing in intensity upward and downward, and finally graduating into the adjacent shales or 

sands. The thickness has not been noticed over 70 to 80 feet. 

This structure has been induced by the heat developed in the combustion of carbonaceous 

matter, for not only arc there remnants of the original stratum with its unconsumed carbon, 

but this porcellanite is identically the same with the substances produced immediately above 

or below seams of coal which have accidentally taken fire and qurnt for a length of time. The 

unconsumed portions are associated with granules of sulphur. Perhaps the decomposition of 

pyrites (extensively disseminated in this series) generated sufficient heat to occasion the ignition 

of the carbonaceous matter of the seams of lignite, and tho cracks or fissures might permit so 

much air to penetrate as would support a slow combustion. That this combustion originated 

within the altered portions is evident from the circumstance of the adjacent lignitic beds being 

unaffected, which could not have been tho case had the heat been transmitted from below. * * * 

Natural asphalt, a well-known product of Trinidad, is extensively disseminated in this 

senes. * * * 

No sections sufficiently extensive occur from which to deduce any very positive order of 

succession; as far as could be ascertained, there seemed to be a great repetition of sands and 

shales of very similar characters. 

The data for estimating the thickness are very uncertain; conclusions founded on the 

inclined positions give at least 3,000 to 4,000 feet. 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 117 

E 17-18. JAMAICA. 

Hill's classification of the rocks of Jamaica is given in Chapter XV (pp. 639-642). 

From his account 443b we take the following description of the deposits assigned to 

the early Tertiary: 

The Richmond beds constitute the upper subdivision of the Blue Mountain series. Their 

arrangement and composition, consisting of shallow marine deposits of worked-over and waterassorted terrigenous material, indicate a succession of more quiet sedimental conditions than 

tho.se which marked the preceding epoch. 

The rocks are mostly black bituminous laminated clays and ferruginous sandstones with 

occasional beds of loose conglomerate. They occur in uniform alternations of thin, regular, 

and evenly bedded strata, varying from an inch to a foot or more in thickness. They are dull 

blue-black on fresh exposure, but undergo excessive oxidation and hence are ordinarily of darkbrown ferruginous colors. In general texture, arrangement, color, and stratification they resemble 

the Eo-Lignitic (lower Eocene) beds of the southern United States·. The clays contain many 

small flakes of carbonized vegetal matter, and silicified wood has been found in the gravel. The 

gravel is mostly derived from the antecedent beds of the lower division of the Blue Mountain series. 

The so-called "sandstones" are composed of cemented grains of waterworn hornblende ~ndesite 

derived from the underlying igneous rocks, and the shales are the same material more finely 

triturated and mixed with vegetal matter. The conglomerates con6ist of rounded pebbles of 

various dimensions and in places attain a thickness of 50 feet. They are almost entirely of 

the same material as those of the lower subdivision. Rounded fragments of the Rudistean 

limestone also occur in them. * * * In addition to these rocks of the conglomerate, former 

observers have noted, from the bluff at Port l\Jaria, specimens of gneiss and crytalline slates, 

"rocks of which no trace either in situ or otherwise have hitherto been found in Jamaica; also 

a fine-grained granite to which nothing analogous has been noted on the island. * * '* In 

this unique collection are many instances of rocks which have totally disappeared from the 

surface of Jamaica but which must have existed during former epochs, either in the formations 

of this country or in .adjacent lands that have been destroyed." a 

At the same locality, as also noted in the Jamaican reports,a the ordinary sandstone is 

rapidly transformed in its seaward extension into a promiscuous assemblage of large pebbles 6 or 

8 inches in diameter. Thi8 fact indicates that some of this material came from the area to the 

north, now occupied by the sea. In this same bed of conglomerate were found the Eocene 

corals described by Duncan, and a few species of mollusks. * * * 

The Richmond formation outcrops in many places a short distance back of the sea along 

the north coasts of the parishes of St. Ann and Trelawney. It is well exposed beneath the 

Cambridge beds south of Cambridge, along the highway on the west side of Great River, as seen 

by the "\vTiter. It also occurs on the south side of the Blue Mountain Ridge in St. Andrews and 

St. Thomas. According to Sawkins, in the latter parish at Blue Mountain Valley it comists of 

"alternate bands of red clay, yellow •sandstone, and light-gray shales, 1,000 to 1,200 feet in 

thickness." 

In general, this formation underlies nearly all the later rocks, and, in our opinion, prior to 

the Montpelier subsidence it occupied an area as large or larger than that of the island of to-day. 

From data presented in the paleontological chapter of this work the age of these beds is 

undoubtedly old Eocene, although it is impossible to draw an exact line between these beds and 

those of the lower division which we have termed Cretaceous, and they are no doubt stratigraphically continuous. 

The uniform alternations of the Richmond beds indicate that they were rapidly deposited 

over a considerable shallow area of deposition; since much of this area was the present locus 

a Jamaican Reports, p. 130. (Entitled" Reports on the geology of Jamaica, or Part II of the \Vest Indian Survey," by James G. Sawkins, with contributions by others.) 
718 INDEX TO THE STllATIGRAPHY OF NORTH AMERICA. 

of the island, it is difficult to infer the situation of the near-by land from which the material 

was derived; some of it may have come from the old nucleus of Blue Mountain Ridge, but in 

our opinion this was not of sufficient size to afford all the material. These facts, together· 

with the presence of foreign material, are at least strongly suggestive of the occurrence of land 

areas during this epoch, concerning the locality of which present knowledge is wholly wanting. 

The Cambridge formation is named after the typical locality of its occurrence at Cambridge, 

between Ipswich and.:Montpelier, in the parish of St. James, in the northwestern portion of the 

island, near the junction of the boundaries of St. James, Hanover, and Westmoreland. 

In places the Richmond beds grade up into irregular alternations of impure clay, marls, 

and yellow limestones, which, in general, occupy a transitional position between the obviously 

land-derived beds of the Blue Mountain series and the ocean-derived limestones of the Oceanic 

series. Argillaceous calcareous marls appear in the upper part of the Richmond beds, become 

successively more and more frequent, and finally dominate. These are accompanied by thin 

beds of impure blue lime8tone of a segregational character, oxidizing yellow on weathering and 

alternating with the marls which gradually increase in thickness and relative proportion until 

they preponderate. Finally these yellow limestones become more purely calcareous :n ascending 

series as the sediments become clearer and freer from land-derived material, until they finally 

pass into the purer White limestones. 

As he was not able to correlate certain divisions of the Cambridge formation 

precisely with one another, Hill distinguished them under the names of Catadupa 

and Chapelton beds. After describing these different occurrences, he continues: 443c 

There are several paleontologic, and stratigraphic features of the Cambridge beds which 

are peculiar and will require more extensive field work for final explanation. We have reason 

to believe that the beds are not connected but occur in broken patches, which, at least in their 

lower portion, like the Cretaceous beds, represent sporadic colonies of lime-making organisms, 

which found temporary foothold at intervals during a period of turbulent deposition generally 

unfavorable to a large development of marginal life. These deductions are based upon the fact 

that in no two localities are the sequence of sediments or association of species identical, while 

in others the beds do not appear between the Richmond and the Montpelier. Furthermore, the 

fossiliferous horizons of the Lower Cambridge are so like some of the Cretaceous that the one 

has been frequently mistaken for the other. The mixture of Cretaceous Rudistes and Eocene 

corals and Mollusca at Catadupa, as seen by us, and of Orbitoides and Rudistes in Portland, as 

noted by Barrett, indicates a transgression of Cretaceous life into the Eocene and further 

denotes the anomalous nature of this formation. 

These beds, while showing sedimentary relations to the Richmond, undoubtedly represent 

a transitional step in the deepening which later produced the Montpelier formation. In some 

places it seems perfectly conformable beneath the latter, while again, as shown by Brown 

and seen in several places by us, they are unconformable. These apparently irreconcilable conditions can probably be explained upon the hypothesis that the island was undergoing dubsidence 

during the Cambridge epoch, although parts of it were then dry land, which was still further 

covered by the Montpelier beds during the succeeding epoch. As shown in another chapter, 

the age of these beds, although containing a remarkable mixture of Cretaceous and Tertiary 

fossils, is undoubtedly Eocene, and with the Richmond beds they constitute the Eocene system 

in Jamaica. 

Of the vVhite limestones, Hill distinguished two series, the Oceanic and Coast 

ser1es. He says: 443d 

The transitional Cambridge beds grade up into rocks of organic oceanic origin. These are 

the White lime.>tone formation of the official Jamaican reports. They have no genetic relationship with the rocks of the Blue Mountain series and differ from them in every physical and 

chemical aspect. 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 719 

The interpretation of the white limestones has been one of tl1e greatest problems of Jamaican 

geology. There have been so many diverse opinions concerning their age and sequence that 

it is almost impossible to obtain from current literature any approximation of their true relations and significance. The difficulties can be readily seen by any one who reads the conflicting 

and apparently involved conclusions in the Jamaican reports. The fragmentary descriptions 

of their local occurrence are frequently well written, but through lack of correlation and erroneous 

deduction they fail to clear up the sequence and age of the beds. * * * 

The truth is, the white limestones of the Jamaican sequence represent several distinct 

formations and ages, from Vicksburg to recent inclusive, but that the greater portion of it, as 

I shall show, is of old Oligocene age. There are even some white limestones in the Cretaceous 

in Clarendon which are almost lithologically indistinguishable from those of the Tertiary. In 

recent years English geologists have observed the discrepancies of previous interpretations of 

the white limestone and suggested, from specimens of the material sent them, that at least an 

upper and lower division might be distinguished. Our investigations will show that not two 

but several subdivisions can be made, and that the rocks hitherto classified under this general 

head really belong to several distinct formations of two great series, the Oceanic and the Coastal, 

the former constituting most of the rocks of this character and occupying large areas of the 

interior upland, while the latter are confined to a narrow belt along the coast. 

The older white limestone formations, constituting the greater mass of these rocks, are 

found in the upland area of the island and are all of Tertiary age. More exactly speaking, they 

are of the Vicksburg stage, which is placed in the Eocene by some writers and in the Oligocene 

by others. The later white limestone formations-including the Coast limestone of the Jamaican 

reports, which we shall describe as the Falmouth formation, and the Hospital Point limestone 

of Montego Bay-are of Pliocene, Pleistocene, and recent age. 

There has also been much vagueness concerning the origin of these rocks, accompanied by 

an opinion on the p·art of many that they are of coral-reef origin. * * * 

Not the least important result of our researches will be a demonstration that the larger 

thicknesses of these limestones are neither of molluscan, coralline, or reef-rock origin, but are 

foraminiferal oceanic deposits and other offshore calcareous oceanic muds composed of organic 

detritus laid down at depths below that at which reef rocks were formed and in periods of eologic time prior to the appearance of the modern reef-building species in the sequence. * * * 

The upland white limestones or Oceanic series, as we shall call the Tertiary formations 

under discussion to distinguish their.. from the later deposits of the Coastal series, consist of 

white limestones of varying texture and hardness, and probably aggregate 2,000 feet in thickness. These present a perplexing series of surface and interstitial changes under the influences 

of solution and oxidation, as explained in their detailed descriptions, which render their study 

a difficult task. They consist of deeper-water organic deposits and arc free from coral-reef rock, 

littoral shell agglomerates (such as coquina, cantera, and caleche), beach wash, eolian debris, 

or other clastic formations which characterize the rocks of the Coastal series. They contain few 

macroscopic fossils by which their age can be independently determined, but this is fixed by their 

microscopic fossils and their position between including fossiliferous horizons-the underlying 

Cambridge beds and the overlying Bowden gravels and marls. 

In general, the Oceanic series occupies most of the plateau region, which practically includes 

all the island under 3,000 feet in altitude outside of the Blue Mountain district, except its immediate coastal borders. In the mountainous region of eastern Jamaica these rocks occur as a 

high piedmontal peripheral border around that end of the island. In the western half of the 

island the beds of the Oceanic series completely cover the old Blue Mountain series and occupy 

the higher summits of that portion of the island. 

Owing to the elevation of the plateau region which took place after the deposition of these 

beds, and the subsequent contraction of its oceanic borders by erosion and subsidence, the 

coastward extension of the rocks is truncated and partially embedded near the littoral by the 

still later formations of the Coastal series, which are de·posited unconformably against them. 
720 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The detailed subclassification of the Oceanic series comprises not only the 

Catadupa and Chapelton beds of the Cambridge formation, but also the Montpelier, 

Moneague, and Cobre formations. Of the Montpelier Hill 4438 says, quoting 

Charles B. Brown: 

It consists of thin beds of white limestone, interbedded with a soft white chalky marl, the 

limestone beds invariably containing nodules of flint. The limestones are chiefly soft but seldom compact or crystalline; they form thin beds, which vary from a few inches to 4 feet in 

thickness and are much disturbed, so as to dip in almost every direction over small areas. The 

marl beds, being interstratified with these, of course show the same disturbance and dips and are 

similar to them in thickness. The flints and chert contained in the limestone beds lie usually 

in flattened nodular masses in lines of stratification and arc rarely in beds themselves. They 

arc not connected continuously but are in long, hollow flat masses, and have all the appearances 

of having been deposited around or in the substance of some organic form which was embedded 

in the limestone. These flints are chiefly of brownish-pink, brown, and gray colors. At Knockalva and other places in the vicinity the limestone contains small veins of silica, and also has 

become so thoroughly impregnated with that substance as to be completely changed into a 

siliceous limestone. a 

Microscopic examinations show that the calcareous beds consist of organic oceanic material 

and are composed of the shells of Foraminifera, occasional sponge spicules, and fine crystals and 

amorphous particles of carbonate of lime, like those usually found in all chalky oceanic deposits. 

No terrigenous material whatever has been found in any specimens examined. The Montpelier 

beds are singularly free from molluscan or other visible fossils, except a large species of Orbitoides 

in its lower beds. Nummulime have also been found. * * * 

The thickness of the Montpelier formation is difficult to determine, owing to lack of continuous exposures. Our observations have led to the conclusion that they do not exceed 1,000 feet. 

Everywhere thes-e beds show great disturbance, but not to the degree of the Blue Mountain 

series, usually consisting of more open folds. 

The Montpelier beds are the deepest sediments preserved in the geological structure of 

Jamaica and represent the culmination of the great subsidencE initiated in the Cambridge 

epoch. Judging from the rapid transition between the littoral Cambridge formations and the 

chalks of the Montpelier formation, this subsidence must have been rapid in geologic time. 

The age of the Montpelier beds most probably corresponds to that of the late Eocene (old 

classification) now called the early Oligocene, agreeing approximately with the position of the 

Vicksburg stage of our American Tertiary. This inference is based upon the position of the 

beds above the undoubted lower Eocene of the Cambridge formation and below the undoubted 

late Oligocene of the Bowden formation, together with the occurrence of Orbitoides mantelli. 

In regard to the Moneague formation Hill 443 r states: 

The Montpelier beds grade up into more massive limestones, white in color, firmer in texture, 

often scmicrystalline, sometimes containing casts of fossil mollusks and solitary corals, and 

occurring in well-defined bands of stratification from 1 to 5 feet in thickness. More massive 

texture and regular bedding especially distinguish this formation from the other white limestones of the island, such as the chalky rocks of the underlying Montpelier and the irregular 

lumpy texture of the overlying Cobre formations. These rocks contain many cavernous molds 

of Mollusca and single corals, indicating that a considerable amount of shell debris may have 

accompanied their original deposition. The fossils obtained near Ewarton, Retreat, and Cinnamon Hill, in a firm limestone matrix, were mostly poorly preserved molds of corals and mollusks, 

which the paleontologists could not determine. * * * 

a The description above given refers to Drown's lower division of the white limestone (our Montpelier beds); the 

upper beds (our Brownstown bed8) are more compact and massive and contain fewer interstratified marls_ 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 721 

From their usual association with and occurrence above the :Montpelier beds, there is little 

doubt that they were continuously deposited with the latter an~ possibly may represent shallowing but nevertheless deep-water beds after the culmination of the :Montpelier subsidence. Our 

knowledge of the upper contact .of these beds is very deficient. In Clarendon and St. Elizabeth 

they clearly occur below the Cobre and Porus (Bowden) formations. 

The name Cobre formation is applied to a local occurrence of white limestone 

exposed in the canyon of the Cobre. Hill says that from the Bog Walk section it 

is evident that the Cobre formation lies stratigraphically above the supposed Moneague beds at Ewarton and below the May Pen formation. Its relations with the 

Bowden beds are not established. It apparently occupies an intermediate position 

between the Moneague and the Bowden. 

For description of the later Tertiary formations, see Chapter XVII (pp. 799-801). 

E-F 15-16. CHIAPAS, GUATEMALA, TABASCO, AND YUCATAN. 

The peninsula of Yucatan is mapped in accordance with an interpretation of 

the map given by Sapper, 6940 who characterizes the Tertiary of the States of Tabasco 

and Chiapas as follows: 

The major part of the Tertiary terranes consists of marls and shales with sandstones and 

conglomerates as well as limestones which are, however, of minor importance. 

The fossils which Sapper cites from these formations are Pecten, Ostrea, Nummulites, Elypeaster, and different Glossophora ( ~), lamellibranchs, and corals. 

Sapper regards these fossils as representing the upper Miocene or some of them 

as coming from a lower horizon. Dall thinks it probable that they represent the 

Oligocene. Sapper further cites certain remains of plants and Foraminifera which 

were determined by Schwager to be of Tertiary age. 

Heilprin 433a describes in the following terms the limestone of the Sierra de Yucatan, a range of hills which runs in a northwest-southeast line from Ticul in the 

direction of Peto: 

The rock formation of the Sierra de Yucatan differs in many particulars from that of the 

basal plain. The surface rock, forming the crest and the slopes on either side-presumably 

. an anticlinal structure-is a fairly compact red or reddish limestone, which seems to rest at 

nearly all places, as we had occasion to observe in the Caves of Calcehtok and Loltun, on a 

semicrystalline white or gray marble or op an exceedingly fine grained cream limestone, somewhat resembling in texture true lithographic stone. A brecciated limestone, containing fragments of the last-mentioned rock, occurs at intervals along the base of the hills, and we also 

found it among the rocks used in the construction of the buildings (now ruins) of Labna. I 

am not absolutely certain as to the age or even as to the general nature of the red rock. The 

brecciated masses are almost undoubtedly of marine origin, and they give evidence of the 

encroaches of the sea after the underlying rock had not only been formed but been converted 

into its present semicrystalline condition. In other words, the present range of hills probably 

by that time already existed. It is, however, less clear that the red or reddish rock which 

extends away from the base of the hills but forms their slopes is of marine origin. Its universality would seem to indicate that it was of this nature, but at many places where I examined 

it, on and off the crests of the hills, it bore suspicious marks of being a disintegration product, 

which had subsequently undergone cementation. The only fossil that I found in it, on any surface exposure, was a Helix (probably identical with a species now living in the same region), 

which was obtained from near the summit of the pass between Ticul and Santa Elena, at an 

48011°--12----46 
722 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

·absolute elevati~n of perhaps 300 feet. It occurred in a thoroughly hard rock, but this circumstance is in itself no proof of actual antiquity, since in a purely calcareous region such 

as this one rock cementation is a rapid process, as we had occasion to observe in the terrestrial 

(fossiliferous) limestone now forming near a quarry about 2 miles south of Ticul. In th«ii red 

rock which in the cave of Calcehtok overlies the gray limestone I found the impression of a 

single gastropod, which I should unhesitatingly refer to a terrestrial form and to a genus of 

Pupidre close to Macroceramus, if indeed it is not Macroceramus itself. I could find no vestiges of marine mollusks, but yet they may well occur in other parts of the rock and it would, 

perhaps, not be safe to conclude that the entire red rock is of terrestrial origin, or that it represents a single type of formation. 

No doubt attaches to the heavily bedded gray and white limestones and marbles which 

are so well exhibited in some of the deeper caves, such as that of Calcehtok, for example. The 

mouth of this cave, according to a rough approximation, is some 200 feet above the sea. At 

a depth of some 50 feet the red limestone appears in a solid mass, and beneath it we reach the 

crystalline limestones, which are disposed in layers of 10 to 15 feet thickness. ·Fossils are not 

abundant in this rock, and Col. Glenn, who had explored this-cave on a previous occasion, was 

of the opinion that no fossils were to be found in it. After considerable search, however, we 

discovered a few in an indifferent state of preservation, and still later some whose characters 

were sufficiently defined to permit us to determine their relationship. Among these are a 

Pecten, with little doubt Pecten nucleus, the cast of a large Marginella, apparently the living 

MargineZZa labiata, a Potamides or Cerithidea, the impression of the apex of a large Oliva (of 

the type of Oliva literata), and a single impression of Venus cancellata. While the above forms 

are barely sufficient to determine the exact age of the formation in which they occur, whether 

Pliocene or Miocene, I am inclined to believe that it is rather the former, the mountain rocksemicrystalline or highly compact and but scantily fossiliferous-being a compressional alteration of the much less compact and highly fossiliferous rock of the basal plains. But whether 

Pliocene or Miocene, I think it can be all but positively assumed that it is not older than Miocene, 

although it has been asserted that it represented the Oligocene or Vicksburgian period.a 

F 17-18. CUBA. 

T. W. Vaughan has contributed to this work the following notes on the early 

Tertiary of Cuba: 

The only rocks that we positively know to be of Eocene age in the island occur in the 

Province of Santiago, not far from the city of Santiago, where they are associated with manganese ores. This information is furnished by William H. Dall, who determined some fossils 

collected by Clarence King. Associated with the manganese ores in this province are foraminiferal limestones and foraminiferal marls, which appear to be of Eocene age and are tentatively referred to that epoch. It is probable that the limestones occurring along the northern 

foot of the Sierra Maestra from Los N egros to Cabo Cruz are also Eocene. Eocene limestones 

are reported from the Province of Santa Clara, particularly near Cienfuegos, from the Province 

of Matanzas, near the city of Matanzas, and from the vicinity of Havana. The data on which 

the age of these rocks has been determined for these three provinces seem doubtful, the doubt 

for the vicinity of Havana being so strong that the formations in that area are referred to the, 

late Oligocene. 

North of the city of Pinar del Rio and along the Rio Santa Fe, just south of the village of 

San Jose, sandstones underlie the upper Oligocene limestones. No paleontologic data by which 

the age of this formation could be determined were procured, but it may be of Eocene age. 

A yellowish marl composed of the remains of Radiolaria has been described by several 

authors as occurring in Baracoa. This material underlies the upper Oligocene and is probably 

of early Oligocene age. 

Limestones and marls of late Oligocene age constitute by far the most widespread geologic 

formation in Cuba. They extend uninterruptedly from the Province of Pinar del Rio to the 

a Agassiz, Alexander, Three cruises of the Blake, vol. 1, p. 69. 
• 

EARLIER TERTIARY (EOCENE AND OLIGOCENE). 723 

Province of Santiago. The most westerly locality at which rocks of this age were observed 

was in the Province of Pinar del Rio, some 4 miles north of the city of that name, on the road 

to Vifiales. Lithologically the material is either soft limestone or calcareous marl. There is a 

quarry in yellowish upper Oligocene limestone at the town of Consolacion del Sur, from which 

a fair collection of fossils was obtained through the kindness of the alcalde of that town. Limestones and marls, with a few beds of calcareous sands, occur over large areas in the vicinity of 

Havana, extending from the city toward the west, south, and east. 

Limestones and marls of the same age, with conglomerates, occupy extensive areas around 

Matanzas and east of that city. The gorge of Yumuri River is cut through rocks of this age 

and exposes an excellent section. At this place the river runs nearly east and west through a 

narrow canyon 500 to 600 feet wide. From its bottom the vertical distance to the top of the 

highest level through which it is cut is some 450 feet. The gorge itself is about 200 feet in depth. 

The rocks dip at an angle of about 27° SE., the thickness here exposed being estimated at 600 

to 700 feet. The whole section, except the lowest 100 feet, at the west end of the gorge, is 

composed of limestone, more or less impure, with a few beds of sandstones and conglomerates 

near the top of the section. Characteristic upper Oligocene fossils are abundant. The writer did 

not collect any upper Oligocene fossils in the Province of Santa Clara but has reason to believe 

that limestones of this age are extensively developed in its northern and southern portions. 

Upper Oligocene yellowish calcareous marl or limestone are found in the vicinity of Nuevitas; also at Baracoa, where they immediately underlie the Pleistocene coastal soborruco. There 

is a very great development of marls and limestones, containing large numbers of reef corals, 

in and around the city of Santiago. The terraces in this city, excepting the lowest soborruco, 

have been cut into upper Oligocene formations. Upper Oligocene limestones have also an 

extensive development in the vicinity of Manzanillo. 

G-H 14, H-I 15. TEXAS, LOUISIANA, AND ARKANSAS. 

The following discussion of the early Tertiary of Texas, Louisiana, and Arkansas has been compiled by T. W. Vaughan from the literature, from unpublished 

manuscript or notes of Alexander Deussen, C. H. Gordon, and A. F. Crider, and 

from the results of his own researches. 

Space will not permit detailed descriptions or geologic sections, and for further 

information the reader should consult the publications listed in the bibliography 

(pp. 840-865) under Nos. 297, 299, 370,401, 406, 407, 408, 430, 485, 486,487,488, 

633,832, 833, 838. Additional references are given on page 731, and many of these 

publications contain still other citations. 

GENERAL SECTION. 

The same division of the Eocene into Midway, Wilcox, Claiborne, and Jackson can be 

made in the Coastal Plain area west of Mississippi River as east of that stream (see p. 731); 

for the Oligocene, however, a different classification is necessary, as the Vicksburg is not so far 

west as Red River, and the Apalachicola group is not known in the western area, the sediments 

stratigraphically equivalent to the Apalachicola being of estuarine or littoral character, similar 

to those across southern Mississippi. In the table opposite page 724 the section for Arkansas 

and Louisiana is modified from the one published by A. C. Veatch838a and that for Texas east 

of Guadalupe River has been furnished by Alexander Deussen. 

EOCENE. 

~lJidway group..-The Midway group is extensively developed from Arkansas southwestward 

across Texas to the Rio Grande. Usually the group has not been subdivided, and the name is 

therefore applied in a formational sense. However, future studies may lead to subdivision 

and the adoption of several proposed names for local manifestations. There is a general unconformity by erosion between the Midway and the underlying Cretaceous, but it is usually con-
724 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

cealed or inconspicuous because of the similarity of the Eocene and 'Cretaceous sediments. In 

northeaRtern Arkansas the :Nfidway overlaps the Cretaceous, and rests upon a Paleozoic floor. 

Stephenson and Crider, in an unpublished manuscript, state: 

"In Pulaski County, Ark., the strata of the Midway formation, where most completely 

developed, are separable, according to HarriR,a in ascending order into (a) white, compact sand 

(2 feet); (b) ledge of calcareous sandstone (2t feet); (c) the 'Turri tell a limestone' (8 feet); (d) 

the 'Ostrea [Gryphrea] limestone' (3 feet); (e) the 'Enclimatoceras limestone' (1! feet). In 

general, the 'Turritella limestone' in Arkansas consists of layem of hard light-gray to blue 

limestone interbedded with layers of Rand, and this division is the one most often seen in outcrops. The formation is easily separable both lithologically and paleontologically from the 

underlying Paleozoic rocb and the overlying younger formations." 

. According to Harris and to Stephenson and Crider, the northernmost Midway outcrop is 

near Newark, in Independence County, Ark., whence it has been traced southward, more or less 

continuously, along the edge of the Paleozoic rocks to a point near Rockport on Onoshata River, 

Hot Springs County. North of the locality near Newark it has not been recognized on the surface or in well borings. In southern Missouri the group may be represented by the Porters Creek 

clay. From Olyphant, Jackson County, to Russell, White County, the Midway outcrops in 

numerous places along the St. Louis, Iron Mountain & Southern Railway and on the terrace-like 

elevation which extends almost unbroken from Russell to Olyphant. It occurs in Pulaski and 

Lonoke counties. The best exposures in Arkansas are between Little Rock and Malvern. It 

outcrops in Little Rock near the point where the Hot Springs wagon road crosses the St. Louis, 

Iron Mountain & Southern Railway and may be traced almost continuously from this place westward to Malvern. Outcrops of the Midway are not known in Arkansas southwest of Hot Springs 

County. 

In Louisiana two outcrops of the Midway are known, one on the road from Marthaville 

to Many, at Rocky Spring Church, in Sabine Parish, and the other at King's salt works, in 

southwestern Bienville Parish. These outcrops have been brought to the surface by anticlinal 

folding. The material in both localities is calcareous.408a Harris 407e says regarding a third 

probable outcrop: . 

"Farther to the south in the Sabine uplift territory-for example, along the Texas & 

Pacific Railway for over a mile in the vicinity of Marthaville-;-Ostrea thirsac} a very characteristic fossil of the basal Wilcox formation, occurs in great abundance. As the strata in 

that vicinity dip to the south, though but slightly, it is evident that Midway beds must occur 

at the surface over a considerable area to the north. Their geographic distribution has not 

yet been worked out." 

In Texas the basal contact of the Midway has been positively identified at only two localities-on Brazos River 11 miles above the Falls-Milam county line 403a and on Frio River.832 e 

At the former locality no erosion unconformity can be seen, notwithstanding the great faunal 

change; at the latter locality there is evidence of such an unconformity. Deussen, in an 

unpublished manuscript, says that northeast of Brazos River "at the base of this formation 

are usually found bluish micaceous clays or clayey sands with occasional light-yellowish fossiliferous limestone layers of marine origin. These arc succeeded by sandy ledges, resting on 

which are generally found black selenitic clays. The outcrop constitutes the Eastern :Nfarginal 

Prairies and occupies a narrow belt extending approximately north and south in Van Zandt, 

Kaufman, Henderson, Navarro, Freestone, Limestone, Falls, Robertson, and Bastrop counties. 

Much of the exposure is obscured by materials of later age. This formation in northeast Texas 

averages about 260 feet in thickness. The dip varies between 1° and 5° SE." 

Southwest of Bastrop County the Midway has not yet been definitely traced in Texas, but 

evidence obtained by Vaughan along Frio River and the Rio Grande indicates that it extends 

into Mexico. On Frio River,832e 5 miles due north of the southern boundary of Uvalde County, 

a Harris, G. G., Ann. Rept. Arkansas Geol. Survey, 1892, vol. 2, pp. 28, 29. 

b Through a slip of the pen, 08frea sell:£jormis in the original.-T. "\V. V. 
Section of older Tertiary formations in Arkansas, Lonisiana, and eastern Texas. 

--------------------------------------------------------------------------~--------------------~---------------------------

s u:i P. "' "' ;:; tl ·;::: 0 >-. "' ... w. w. 0 

Arkansas and Louisiana. Eastern Texas. 

------------------~------------------------~-------i\ ______________________________ _ 

Formation. Thickness Character. Formation. Thickness t'll.ha t (feet). (feet). ~,rae er. 

.--------~------------------------------------------------------------------~-------------------------

Fleming clay. 260 Green calcareous clays, with a few brackish-water fossils. Fleming clay. 100--400 Gray, white, and bluish-white bedded 1.::alcareous clays, with numerous small concre- tions of lime; occasional lenses of sa-.Ad. 

------------------------------------------- ----~------------------

Catahoula formation. 

Vicksburg limestone. 

Jackson formation. 

Cockfield formation. 

-----------

St. Maurice formation. 

Wilcox formation. 

Midway for1r.ation. 

Near-shore deposits; sandstones, occa- 1,000-1,200 sionally quartzitic, and green clays, 

with fresh-water shells and land plants. 

Limestones and calcareous, somewhat 

100-200 lignitiferous clays, containing marine 

shells. 

Catahoula sandstone. 

200-550 Highly fossiliferous shallow-water marine Jackson formation. 

sandy calcareous clay. 

300-390 

Lignitiferous sands, and 

clays, with plants and 

occasional beds of ma- rine shells. 

Y egua formation. 

Cook Mountain formation. 

\ 

' 100-300 Hard blue semiquartzitic sandstones. \ 

50-60 

500-600 

Calcareous blue clays of 

Angelina counties only. 

sandstone, which passes progressi 

of Claiborne age. 

A very persistent series of gray w'"ua~"" 

forms the base. 

in Sabine, Ran Augustine, and 

is occu1,1ed by the Catahoula 

in the col~u until it includes rocks 

es, the Wellborn beds of Kennedy, 

Green calcareous clays with con-:(tions of se.le\).ite; occasional lenses of sand and 

lignite; possibly also occasionalc~;nses of fossilifl s clays. 

Lenticular masses of yellow san~ 1 an.d clar; ~~casio lenses of green ~alcareous glauconitic fossiliferous marl; oq casional fossili:fercus calcareous ;;oncretwns, beds 

of limonite and lignite. r \. 

200-500 

Fossiliferous sandy clay, 

containing shallowwater marine shells. 

Landward 

these formations merge 

into lignitif- erous sands 

and clays 

without dl.stinctive ma- rine fossils. 

-------~-------- ---------

Red ferruginous indurated and pr Jba~~ altered ~and, lenses of lignite and clay~ 

400-500 

20-260 

Mount Selman formation. 

Lignitiferous sands and 

clays, with land Wilcox formation. 

plants. 

200--400 beds and concretions of limoni•;e. ·~ 

100-200 Palustrine phase, consisting of " ite ~ Queen City beds of Kennedy). . j 

500-800 

Lignitic beds, consisting of lenticular masses of sand, clay, and li~fte. Clays § . are leaf bearing and in places•carry crocodi.e teeth; large concretions, som ' 01 <-> g) 

to 30 feet in diameter, of hard, flintli''e sanllstone are especially characteristic. > gJ as ----------- ----------------- -~--· "' § 

:Marine phase, consisting of calcareous gl~uco~'tic fossiliferous marl, alternating 

with beds of sand, clay, and lignite. Exp ed only on Sabine River; does 

not outcrop in the central Coastal Pla:n regi , the Wilcox being there repre- ~ 

sented by the palustrine phase only, \nto which the marine phase grades. ~ 

--~---- ------------------ ~------ --------

Limestone and black calcareous clays. Midway fo;mation. 

100-200 

Pall!-stri_ne deposits co~~isting of lentic!lhr mass~s of sand, cl!ly, and P?ssibly lignite, 

with mdurated fossiliferous concretw1,1. This member srmulates rn composition 

the basal member of the overlying Wil·~ox formation. 

100-200 Black and blue fossiliferous shales, etc. of distinctly marine origin. 

--------- --~----~--~----- -----~----------------------- ~----- ---------------------------------

~ 0 

"' 

~ 

0 "' 

Beds separated by a :pronounced break 

in the fauna, which IS concurrent with an erosion unconformity now traced 

from the Carolinas across Texas. 

a The Jackson, Claiborne. and Wilcox which are fossiliferous and distinct in central Louisiana, grade toward the north into lignitiferous beds containing no distinct fossils. In northern Louisia111. and southern Arkansas the 

fossiliferous Jackson limits this lignitifero~s complex above. Still farther north however the Jackson also grows lignitiferous and merges with the rest. The Midway, likewise, in the upper embaymelt,region shows a decidedly 

lignitiferous tendency and may in places merge with the lignitiferous time equivalents of th~ other Eocene beds. 

48011°-12. (To face page 724.) 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 725 

no limestone was found, but there is a yellowish or bluish sandstone, usually rather soft, containing Midway fossils. The Midway also occurs along the Rio Grande, near the WebbMaverick county line, above the mouth of San Ambrosia Creek.8320 The material consists of 

dark-brownish or yellow clays and· soft sandstones. The thickness was not determined. 

According to Dumble 298 the main divisions of the Texas Eocene extend into Mexico. 

Wilcox formation.-The following statement regarding this formation in Arkansas and 

Louisiana is modified from that of A. C. Veatch.838d 

Overlying the limestones and calcareous clays of the Midway formation is the Wilcox 

formation, a series of dark, finely laminated sands and clays containing much vegetable matter, 

either scattered through the mass or accumulated in lignite beds, and a few layers containing 

marine shells. It commonly differs from the underlying Midway in the presence of lignitic 

material and fossil leaves and when containing marine fossils is readily distinguished from both 

the Midway and the overlying Claiborne. Toward the coast, where it is overlain by the very 

calcareous, argillaceous, fossiliferous St. Maurice formation of the Claiborne group, its upper 

limit can be fixed with exactness, but farther inland, where estuarine and swamp conditions 

persisted until Jackson time, no separation is possible except on a purely paleontologic basis. 

On the whole, the formation is predominantly sandy. Vea,tch closes his description as follows: 

"The Sabine [Wilcox] formation and its equivalent beds in the undifferentiated Eocene 

underlie the whole of Louisiana, except the limited areas occupied by the outcrops of the 

Cretaceous and Midway domes, and all of Arkansas south and east of thA Cretaceous and Midway 

outcrops. Its thickness, as shown by carefully constructed sections in which local irregularities are reduced to their proper minor importance, ranges from 300 feet in northern Bossier 

Parish to from 800 to 900 feet near N achitoches and on Sabine River." 

From an unpublished manuscript by Deussen the following description of the Wilcox 

formation in eastern Texas is taken: 

"In eastern Texas the Wilcox formation comprises a series of beds of palustrine and littoral 

origin, carrying deposits of lignite and glauconitic, fossiliferous, nonlignitiferous beds of marine 

ongm. This formation consists chiefly of a great mass of lenticular beds of sand, concretion 

and leaf bearing sandstones and clays, sandy clays, and lignites, all of palustrine origin. Crossbedded sands and sandstones also occur. In places the sand is indurated into a hard sandstone 

that is locally useful for building purposes. Thick lenses of lignite of good grade, irregularly 

distributed, give to the formation great economic value. Plant remains indicative of the 

shallow-water origin of these beds occur at a number of places. The lignitic and palustrine 

deposits apparently grade seaward into glauconitic and fossiliferous marls of marine origin. 

The great thickness of these shallow-water sediments-500 to 600 feet-is indicative of subsidence contemporaneous with deposition. It is otherwise impossible to account for this 

thickness. Along Sabine River close to the southern margin of the outcrop of the formation 

glauconitic beds of marine origin occur, which carry characteristic Wilcox fossils. 

"The rocks of this formation outcrop over a wide belt of country, occurring in large portions 

of Robertson, Limestone, Leon, Freestone, Navarro, Anderson, Henderson, VanZandt, Srnith, 

Gregg, Harrison, Rusk, Shelby, Panola, and Sabine counties, occupying a position to the east 

and south of the Midway exposures. Where they are not covered by deposits of later age they 

almost invariably give rise to sandy soils easily eroded. The sandy outcrop constitutes a 

portion of the east Texas timber belt. 

"In northeastern Texas, in the counties of Cass, Marion, Harrison, Panola, Gregg, Smith, 

and Upshur, the Wilcox formation is generally seen to underlie a red sandstone which carries 

casts of Venericardia planicosta and appears to be an altered greensand. This red sandstone is 

provisionally referred to the Mount Selman formation of the Claiborne group. 

''The uppermost beds of the Wilcox formation in this portion of the State consist of a 

series of laminated or thinly stratified white and red sands and sandy cla:ys, in many places 

merging into one another. They do not carry any lignite, so far as we are aware, nor have 

they yielded thus far any organic remains. These deposits are so distinctive in this portion of 
726 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

the State that they have sometimes been described as a separate formation, to which the name 

Queen City has been applied by Kennedy.a 

"The lower beds of the Wilcox in northeastern Texas, which are seen to underlie the beds 

above described, are similar in all respects to the deposits occurring on the Brazos." 

West of the Colorado River the Wilcox or its representatives have not been definitely 

traced, but the studies of Penrose, Vaughan, and Dumble have proved that it is extensively 

developed along the Rio Grande. Vaughan 832b has shown that on the Rio Grande 3t miles 

above the mouth of San Ambrosia Creek, Maverick County, sandstones and thinly bedded 

lignitic sands carrying Midway fossils underlie coarser sands outcropping in the vicinity of the 

Chupadero ranch and extending thence northeastward through Carrizo Springs and Batesville. 

These sands are the Carrizo sands of Owen 625 and are probably the lower portion of the Wilcox. 

They are at least 150 feet thick. They are overlain by about 300 feet of fine-grained micaceous 

sandstones, which are succeeded by alternating beds of clay, shales, and sandstones, at least 

400 feet thick, and these in turn by clays, sandstones, and lignite beds 190 feet thick. 832 ct 

Dumble 297 b reports: ''About 35 feet above the San Pedro seam [Santo Tomas] there is a band 

of shell breccia which contains a great number of fossils. Among there were Ostrea divaricata 

Lea, Anomia ephippoides Gabb, Oorbula texana Gabb, and many others." These fossils belong 

to the Claiborne group and occur between the two coal seams in this mine, or the last division 

of the section described above belongs to the Claiborne. The Wilcox along the Rio Grande is 

probably at least 850 feet thick. · 

Claiborne group.-In central Louisiana the Claiborne group is divisible into a lower fossiliferous formation, the St~ Maurice, and an upper formation, the Cockfield, which contains no 

marine fossils. The St. Maurice formation is much more calcareous, glauconitic, and clayey 

than the underlying Wilcox formation and where typically developed contains no lignitic nor 

lignitiferous matter, though to the north it changes to lignitiferous sands and clays and 

merges into the undifferentiated Eocene. 

The thickness of the St. Maurice formation is 250 to 300 feet in the region about Monroe, 

but increases to over 500 feet at Winnfield. On Sabine River the thickness, calculated from 

dip observations, is 550 feet. 836 In a well recently put down near Robinsons Ferry, Tex., at a 

depth of 1,250 feet fossils were obtained that W. H. Dall regards as Claiborne, indicating that 

the thickness is as much as 700 feet. 

Harris 4070 says: ''The Claiborne group borders the Sabine< uplift. It is represented only by 

patches in Gregg, Marion, and Cass counties, Tex, and Caddo and Bossier parishes, La., where 

it has been for the most part carried away by long-continued erosion. It spreads out extensively in Rusk and Nacogdoches counties, Tex., and Bienville and Winn parishes, La., where 

the dip is slight, but it narrows down in Sabine Parish, where a steep dip carries it beneath the 

later Tertiary deposits." 

The northwestern area of the St. Maurice formation referred to in the following note of 

Harris 407 d probably represents the Mount Selman formation of Texas. 

"In the Caddo field, as already defined, marine Claiborne fossils have been found in but 

one locality, by the roadside about one-fourth of a mile east or east-southeast of the railway 

station at Vivian. Here, as at Roberta, Bolinger, and Plaindealing, in Bossier Parish, and in 

Ouachita County, Ark., the fossils are in the form of casts in very ferruginous indurated layers. 

From their appearance, which is very different from that of the fossil species so abundant and 

characteristic of the Claiborne from Bienville Parish to Nacogdoches County on the south, it 

is inferred that either these northern forms existed under considerably different conditions 

from their southern relatives or they represent a somewhat older type of life. It is possible 

that the Sabine uplift was more or less manifest in early Eocene or perhaps even late Cretaceous 

time. Desoto Parish, La., as well as Shelby, Panola, and Harrison counties, Tex., may have 

constituted an island in Claiborne time. The ferruginous, more or less brackish waters to the 

north of the island would naturally contain a very different fauna from that flourishing in the 

pure sea water to the south." 

a Kennedy, William, Proc. Acad. Nat. Sci. Philadelphia, 1895, pp. 135, 136. 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 727 

The Cockfield formation comprises lignitiferous sands and clays which occur in central 

Louisiana between the St. Maurice and Jackson formations and is extremely similar in lithologic 

character to the Wilcox formation, with which it was at first confused. It contains no marine 

mollusks and is characterized by thin, impure lignite beds and clays which in many places contain plant remains in an excellent state of preservation. It is identical in appearance with the 

lignitiferous complex to the north (undifferentiated Eocene), of which it forms a part, and can be 

definitely differentiated only when fixed between fossiliferous Claiborne and Jackson strata or by 

paleontologic data. (Modified from A. C. V catch.) 

Of the Claiborne group in eastern Texas Deussen has the follov,~ing to say in an unpublished 

manuscript: 

"In eastern Texas the Claiborne group comprises three formations-the Mount Selman, 

Cook Mountain, and Y egua-which are lithologically and genetically distinct. 

"The Mount Selman formation consists chiefly of dark-green and brown sands and sandstones, with thin seams and concretions of limonite. The fossils arc not plentiful and usually 

occur in the form of casts. This formation has been given the name Mount Selman from its 

typical exposur~ at that place in Cherokee County.a These highly ferruginous sands with casts 

of fossils and beds of iron ore of economic value occupy extensive areas in Anderson, Henderson, 

Cherokee, Rusk, Gregg, Harrison, Marion, Morris, and Cass counties. 

"The formation overlying the Mount Selman has been named Cook Mountain, from Cook 

Mountain,b Houston County. At the base of this formation occur beds of greensand, greensand 

marl, and iron ore, all highly fossiliferous and of marine origin; in the medial portion lignites, 

lignitic clays, and sands of palustrine origin are found; at the top occurs another series of fossiliferous greensands, greensand marls, and iron ores of marine origin. Tho thickness along Brazos 

River is at least 400 feet. The outcrop appears in Robertson, Brazos, Leon, Houston, Anderson, 

Cherokee, Nacogdoches, San Augustine, and Sabine counties. 

The lignitiferous unit stratigraphically and conformably overlying the Cook Mountain 

formation, was recognized by Dumble c in 1892 as a separate formation, and he applied to it 

the name Y egua. It consists of clays, sands, and lignites of palustrine and marine origin. The 

clays are characterized by the presence of fragments and concretions of selenite. The thickness 

of the formation varies from 375 to 750 foot. The outcrop appears in Sabi:::J.e, San Augustine, 

Angelina, Trinity, Houston, Madison, Grimes, and Brazos counties. 

"On the Brazos beds belonging to theY egua formation are exposed between the mouth of 

the Little Brazos and a point southwest of Wellborn, in Brazos County. The beds as exposed 

in this section consist entirely of palustrine and lignitifcrous deposits, barren of marine fossils. 

On Sabine River beds belonging to this formation are exposed from a point 3 miles below 

Columbus to a point a short distance below Robertson's Ferry, in Sabine County. The beds 

here are typical palustrine deposits." 

The details of the Claiborne group have not as yet been studied between Guadalupe River 

and Rio Grande. Dumble's work along the latter stream has shown that representatives of the 

marine Claiborne outcrop from Santo Tomas, 30 miles above Lando, to the vicinity of Roma. 

The material consists of lignite beds near the base, soft sandstone, and clays, which are more or 

less calcareous, 297a and grecnsands. The thickness of the marine Claiborne in this region is not 

known. 

J aclcson formation.-The Jackson formation in Louisiana immediately overlies the Cockfield 

and represents a return to marino conditions, being composed of calcareous gray fossiliferous 

sands and clays, which in places contain large calcareous concretions. It extends farther 

up the Mississippi embayment than any other formation bearing marine fossils except the Midway. Its most northern outcrop is in Crowleys Ridge, near Forrest City, St. Francis County, 

Ark. To the south of this locality the formation underlies an extensive area southward from 

a Kennedy, Third Ann. Rept. Geol. Survey Texas, 1892, pp. 52-54. 

b Idem, pp. 54-57. 

c Dumble, E. T., Report on the brown coal and lignite of Texas, character, formation, occurrence, and field uses: 

Rept. Geol. Survey Texas, 1892, pp. 148-154. 
728 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Pine Bluff in Jefferson County to the Louisiana line. 401b, 406a It is concealed in northern 

Louisiana over a large area by the swamp deposits of Ouachita River, but again comes to the 

surface in southern Caldwell Parish and .thence occupies a belt of territory that crosses Red River 

at Montgomery and Sabine River just below Robinson's Ferry, Sabine County. 

According to A. C. Veatch 838e the Eocene beds, which in central Louisiana, Mississippi, and 

Alabama are fossiliferous, all become lignitiferous in the upper portion of the embayment. The 

marine fossils of the Wilcox, St. Maurice, and Jackson epochs each extend farther northward than 

those of the preceding epochs, but in each case the beds bearing marine fossils grade into 

lignitiferous clays and sands containing no distinctive marine fossils. 

Veatch says: "The first name given to this lignitiferous group, which can not be separated 

except on structural grounds, was the Lagrange. This included all the Eocene beds in Tennessee 

above the Midway and was afterward quite logically extended by its author, Prof. J. M. Safford, 

State geologist of Tennessee, to include the lignitiferous sands and clays of Crowleys Ridge,a 

which are of lower Jackson age and are the stratigraphic equivalents of the beds in the upper 

Chickasaw Bluffs. This formation grows more sandy to the north, where at Memphis essentially continuous sand beds 800 feet thick have been penetrated." b 

The following is taken from an unpublished manuscript by Deussen: 

"The Jackson formation in eastern Texas lies stratigraphically and conformably above 

the Y egua and beneath the Catahoula. It consists of a series of calcareous, fossiliferous clays 

of marine origin with large limestone concretions. It outcrops in the region between Trinity 

and Sabine rivers, in Sabine, San Augustine, and Angelina counties. Along the Sabine the 

formation is estimated to be 250 feet thick. It thins rapidly westward and disappears completely between Trinity and Brazos rivers. The formation is characterized by such fossils as 

Umbrella planulata Conrad, Levifusus branneri Harris, and Trochocyatus lunulitiformis var. 

montgomeriensis Vaughan. 

"On Sabine River 1 mile below Robertson's Ferry, in Sabine County, highly fossiliferom, 

calcareous clays and marls carrying large limestone concretions outcrop and carry characteristic 

Jackson fossils. The following species occur here: Mitra millingtoni Conrad, Ilipponyx america nus Conrad, Oalyptrcea trochiformis Lamarck, Ostrea trigonalis Conrad, Area (Scapharca) 

rhomboidella Lea, Orassatellites flexurus Conrad, Cardium (Protocardia) nicolletti Conrad, Dione 

securiformis Conrad, Oorbula wailesiana Harris. 

"The Jackson formation extends from Angelina River in Texas eastward across Louisiana 

into Mississippi. In Texas the time equivalents of the formation have been traced as far west 

as the Brazos. The equivalents in the region of the Brazos, however, are not lithologically 

similar to the Jackson formation and therefore do not belong to the Jackson but are here a part 

of the lithologic unit next to be described, namely, the Catahoula sandstone." 

The Jackson has not been recognized in southwestern Texas, although more thorough 

investigation may discover it in that region. 

OLIGOCENE. 

Vicksburg limestone.-This formation is known west of Mississippi River only in a small 

area in northern Catahoula Parish, La. The material is yellow calcareous clay and yellow 

limestone, which contains typical fossils. 830 

In Louisiana and eastern Texas the Oligocene deposits are divided into two formationsa lower one, the Catahoula sandstone, which in east-central Texas also comprises the uppermost Eocene and which consists of semiquartzitic sandstones and sands with some clay and 

carries a few plant remains, and an upper one, the Fleming clay, which consists of calcareous 

clays with nodules of lime and occasional crystals of gypsum. ------------------------

a Report of John Lundie on waterworks system of Memphis, Tenn., 1896, p. 16. 

b Safford, J. M., Bull. State Board of Health, vol. 5, pt. 7, Feb. 20, 1890, pp. 98-106; Ann. Rept. Geol. Survey 

Arkansas for 1889, vol. 2, 1891, pp. 28-29. 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 729 

Catahoula sandstone.-This formation is thus described by Veatch: 838f 

"Overlying tho fossiliferous Vicksburg clays and limestones is a series of sandstones and 

greenish clays which are generally [very] different, lithologically, from any of the older beds 

of the Tertiary series in Louisiana and Arkansas. The sandstones which are the characteristic 

feature of this formation range in thickness from a few inches to 50 or 60 feet, and thicknesses 

of as much as 140 feet have been reported.a These sand bods are often cemented by silica 

into very hard quartzites, but such occurrences are essentially local, and the quartzitic beds 

pass laterally in very short distances into soft sandstones or even unconsolidated sands. These 

sandstones and quartzitic layers have resisted erosion more than the underlying clays and 

unconsolidated sands of the Eocene and so have formed a line of rocky hills, the Kisatchie 

Wold, extending across Louisiana, into Texas on the one hand and into Mississippi on the 

other. 

"These beds contain no indications of marine lifo, but land plants are abundant and freshwater shells have been found in several places. The change from the conditions existing in 

the Vicksburg is very marked and indicates an elevation during which the region where the 

oceanic conditions were favorable for the growth of marine life was considerably south of the 

present outcrop of the formation. 

"Those beds were observed at Grand Gulf, on Mississippi River, in Claiborne County, 

Miss., by Wailes, the first State geologist of Mississippi, who referred to them as tho Grand 

Gulf sandstones. b Later Hilgard c used tho name 'Grand Gulf group' to include the beds 

exposed in southern Mississippi between the Vicksburg and the relatively recent coastal clays 

(Port Hudson), and the name has been used with varying shades of meaning by different authors 

since that timo.d 

"In view of this confusion and in order to furnish a name not likely to be misunderstood, 

the name Catahoula formation is used in this paper as a synonym for the 'typical Grand Gulf' 

or the 'Grand Gulf proper.' This new name is from Catahoula Parish, La., which is directly 

across the Mississippi Valley from Grand Gulf and where there are many outcrops which are 

lithologically and stratigraphically counterparts of the beds of the old type locality. From 

this place the beds have been traced eastward through Mississippi into Alabama, where they 

apparently grade into a series of fossiliferous sands and calcareous clays known as the 'Chattahoochee group.' To the west they extend in a very pronounced line across Louisiana into 

eastern Texas.e The thickness of this formation, as shown by comparative cross sections based 

on wells at Alexandria and Boyce and on dip observations on Sabine River/ is about 1,100 

feet." 

The Catahoula sandstone in eastern Texas is thus described by Deussen in an unpublished 

manuscript: 

"The Catahoula sandstone Ees stratigraphically and conformably above the Jackson 

formation in eastern Texas and above the Y egua in central and southwestern Texas. It Ees 

stratigraphically and conformably beneath the Fleming clay. It consists of a series of gray 

and blue sandstones, interbedded with brown, gray, and green clays, gray sands, and a few 

deposits of lignite. The sandstones in places carry marire fossils; in other places they carry 

casts of palm leaves, reeds, and great quantities of silicified and opalized wood. A characteristic feature is the occurrence locally of very hard blue quartzites, which, owing to their superior 

hardness, resist weathering better than the adjacent materials and appear topographically in 

the form of hills. These qmwtzites pass laterally in very short distances into soft sandstones 

and unconsoEdated sands. --------------------·-·-------------------

a Kennedy, \Yilliam, Third Ann. Rept. Geol. Survey Texae, 1892, p. 63. 

b Wailes, B. C. L., Agriculture and geology of Mississippi, 1857, pp. 216-219. 

cHilgard, E. W., Report on agriculture and geology of Mississippi, 1860, pp. 147-154. 

dIn this connection see the following: Smith, E. A., and Aldrich, T. II., Science, new ser., vol. 15, 1902, pp. 

835-837; idem, vol. 18, 1903, pp. 20-26. Dall, W. H., idem, vol. 16, 1902, p. 947; idem, vol. 18, 1903, pp. 83-85. 

Hilgard, E. W., idem, vol. 18, 1903, pp. 180-182. 

e Dumble, E. T., Science, new ser., vol. 16, 1902, pp. 670-671. 

I Rept. Geol. Survey Louisiana, 1902, pp. 120, 132-135, Pl. XXXVII. 
730 INDEX TO THE STRATIGRAPHY OF NORTH .AMERICA. 

"The formation ranges in thic.kness from 500 to 800 feet. The outcrop appears as a belt 

extending across the area in an east-west direction, about 15 miles in width, and including 

portions of Sabine, Newton, San .August;ne, Jasper, .Angelina, Tyler, Trinity, Polk, Walker, 

San Jacinto, Montgomery, Grimes, and Brazos counties.'' 

Deussen states that great confusion has existed regarding the age and correlation of this 

unit and, after reviewing the literature relating to it, continues: 

"As here interpreted, the Catahoula sandstone is a lithologic and stratigraphic unit which 

transgresses several biologic zones. Stated differently, it is conceived to be of different ages 

and to have been laid down at different periods in the different regions of its occurrence. In 

southwest Texas it is of Claiborne age, and this kind of deposition seems to have begun in this 

area as early as Claiborne time. In central Texas, in the region of the Brazos, it is largely of 

Jackson age. In eastern Texas it is largely of Vicksburg age. .According to Matson, the 

vertical transgression continues across Louisiana into Mississippi where the formation is of 

post-Vicksburg age. This kind of deposition, be.gun in southwest Texas in Claiborne time, 

gradually shifted eastward, and prevailed in Mississippi as late as middle Oligocene time. 

If this interpretation is correct it precludes the possibility of an unconformity between deposits 

of Eocene and Oligocene age in the Coastal Plain; no evidence of such unconformity has been 

found. It also explains the apparent absence of the Vicksburg limestone in eastern Texas. 

Upper Eocene deposits are not absent in eastern Texas and there is no hiatus in the sedimentary 

series there. The assumption by Hilgard, Hopkins, and Loughridge that the 'Grand Gulf 

group' of Hilgard was stratigraphically continuous across Mississippi, Louisiana, and Texas is 

thus demonstrated to have been correct, if this interpretation is valid, but they were in error 

in regard to the age of the materials in Texas. On the other hand, Dumble's determination of 

the age of his 'Fayette beds' (the Catahoula here recognized) is demonstrated to have been 

correct for southwest Texas, but if the view here maintained has force he is in error in assuming 

that the formation in east Texas is of the same age as in southwest Texas." 

Fleming clay.-Veatch sasg says: "The Fleming clay, which was so named by Kennedy in 

1892 a from Fleming siding on the Missouri, Kansas & Texas Railway near the line between 

Tyler and Polk countie&, Tex., consists of green or bluish-green calcareous clays, differing from 

the underlying Catahoula beds in the presence of numerous small white calcareous nodules and 

the absence of the characteristic Catahoula sandstone layers. Near its base it often contains 

a bed of bright-red clay which forms a convenient line of parting. 

"Although these deposits represent less truly littoral sediments than the Catahoula beds, 

extended search has failed to reveal any marine remains except near Burkville, Newton County, 

Tex., where a brackish-water Oligocene fuunab has been found in a local development of limestone 3 to 4 inches thick. William Kennedy" reports a number of lower Claiborne (Eocene) 

species from this locality, but the collection made by the writer in 1902, which was by far the 

largest made at this point, showed none of the species listed by Kennedy. Dr. T. Wayland 

Vaughan later visited the outcrop and states that the fragmentary material which he was able 

to obtain was regarded by both himself and Dr. W. H. Dall as having a decidedly Oligocene 

aspect." 

This formation in Louisiana outcrops in a belt of country extending from Alexandria, on 

Red River, westward to Burr's Ferry, on Sabine River, south of the outcrop of the Catahoula 

sandstone. Deussen says: 

"This formation consists of grayish sandy clays with small nodules of lime, thin beds of 

sandstone, and bluish and greenish-gray sand with nodules of lime. The occurrence of the 

nodules of lime is a characteristic feature. The formation is from 200 to 500 feet in thickness. 

The outcrop appears as a belt of country varying in width from 2 to 7 miles, lying south of the 

Catahoula outcrop and extending east and west across Newton, Jasper, Tyler, Polk, San 

Jacinto, Walker, and Grimes counties. 

a Kennedy, William, Third Ann. Rept. Geol. Survey Texas, 1892, pp. 62-63. 

b Veatch, A. C., Rept. Geol. Survey Louisiana, 1902, p. 136; Maury; C. J., Bull. Am. Paleontology No. 15, vol. 3 

1:)02, p. 80. 

cBull. U.S. Geol. Survey No. 212, 1903, p .. 53. 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 731 

"Much the same interpretation must be given to this formation as has been given to the 

Catahoula, for .it appmtrs that these clays, like the Catahoula sandstone, transgress several 

biologic zones." 

Oligocene strata have not been recognized in southwestern Texas but may be present there. 

G 17, H 16-17, I 15-17, J 16. SOUTH ATLANTIC AND EASTERN GULF COASTAL PLAIN AND 

NORTH END OF MISSISSIPPI EMBAYMENT. 

The following discussion (pp. 731-745) has been compiled by T. W. Vaughan 

from the literature and from the unpublished results of G. C. Matson and E. W. 

Berry in western Florida, southern Alabama, and Mississippi, of E. W. Berry in 

western Tennessee and Kentucky, and of his own researches. 

As the space allotted to this subject is limited, it is not possible to present 

detailed descriptions of the several formations or to give geologic sections of specific localities or lists of the important fossils. Further information will be found 

in the publications listed in the bibliography (pp. 840-865) under Nos. 141, 178, 179, 

212, 214, 369, 403, 404, 405, 438, 557, 580, 583, 693, 737, 744, 751, 831, 835, 843. 

Many of these publications contain still other citations. 

A series of reports on the Atlantic and Gulf Coastal Plain of the United States 

is in preparation in cooperation between the United States Geological Survey and 

the respective State surveys. These reports will present as complete discussions of 

the different geologic formations, the geologic structure, etc., as present information 

will permit. 

GENERAL CLASSIFICATION. 

For the Eocene formations a classification into four groups has been adopted in the Gulf 

and South Atlantic Coastal Plain region. The type sections of the three lower groups occur 

in Alabama along Alabama and Tombigbee rivers, and that of the highest is in Mississippi. 

These groups are the Midway, Wilcox, Claiborne, and Jackson. The marine Oligocene is 

divicled into two groups-a lower, the Vicksburg, and an upper, the Apalachicola. The former 

takes its name from Vicksburg, Miss., the latter from Apalachicola River, Florida. The nonmarine Oligocene of southern Alabama, Mississippi, Louisiana, and Texas has received no 

group name. The Catahoula sandstone and the Fleming clay of Louisiana and Texas, which 

are mostly of upper Oligocene age, are described on pages 729-730. 

Each stratigraphic group will be described in ascending order, its distribution and variations 

being indicated. 

EOCENE. 

Midway group.403-This group takes its name from Midway Landing, on Alabama River, 

in Alabama, where it is divided into three formations. 749 The lowest, the Clayton limestone, 

rests unconformably on the Upper Cretaceous. It is an impure limestone 25 feet thick in 

western Alabama along Tombigbee River, but it increases in thickness to the east and along 

Chattahoochee River includes fully 200 feet of alternating calcareous sands and limestone. The 

Clayton limestone is overlain by the Sucarnochee clay, which on Tombigbee River is a series 

of black or dark-brown clays at least 100 feet thick. At Black Bluff, on Tombigbee River, 

these clays contain a few fossils but except in the lowermost strata are almost devoid of lime. 

Toward the east, however, they become more calcareous, and in Wilcox County, east of Alabama 

Hiver, they form the basis of some fine black prairie lands. This formation has not been traced 

east of Wilcox County. The Naheola formation, which conformably overlies the Sucarnochee 

clay along Tombigbee and Alabama rivers, is composed of 150 feet or more of gray sandy 

glauconitic clays, containing many marine fossils. It does not extend so far eastward as 

·Chattahoochee River. 
732 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The Midway group has been identified along Chattahoochee River between Alabama and 

Georgia, in the vicinity of Fort Gaines, whence it extends as a narrow belt, only a few miles 

wide, in a northeast direction to Montezuma, on Flint River, and a short distance beyond into 

Houston County.a As the group in Georgia has not been subdivided into formations, it is 

termed the Midway formation in this State. It is separated from the Upper Cretaceous by 

small erosion unconformities, but at no place has there been found good evidence of any profound physical break between the two. According to Veatch, "the formation is mainly a 

marine deposit consisting of sands, clays, and marl or limestone. The sand is varicolored, 

generally loose or friable, and contains lenticular layers of white clay. A characteristic of the 

lower part of the formation is a rather wide distribution of limonite in thin crusts in the sand 

and sandy clay and in the form of hollow concretions having black, polished botryoidal interiors, 

The limestone is fossiliferous and in general highly arenaceous, but in a few places it is sufficiently pure for use in the manufacture of lime. Friable marls, made up of glauconitic quartz 

sand, clay, and shells occur, and also laminated black clay and fuller's earth. The limestone 

is conspicuous at several localities and is the phase of greatest stratigraphic importance because 

it is abundantly .fossiliferous, but sand and clay probably make up the greater part of the 

deposit. The thickness of the Midway on Chattahoochee River was estimated as 218 feet by 

Langdon.b The thickness to the northeast is probably greater, and although it can not be 

accurately estimated, it is probably as much as 400 feet." 

There are no known exposures of the Midway formation east of Houston County in Georgia, 

nor are there any in South Carolina east of Santee River. Sloan 744a has described an occurrence 

in the vicinity of Georgetown, at Perkins Bluff on Black River, of 16 feet of buhr rock, silicified 

black shale, and compact red sands, immediately and unconformably overlying the Peedee 

(Cretaceous). Species of Midway fossils were obtained from the material at this locality. 

This is Sloan's Black Mingo formation, and he has also referred to it other outcrops along Black 

and Sampit rivers. 

West of Alabama the Clayton limestone, the lowest formation of the Midway group, 

extends into Mississippi, where it is represented by a series of hard crystalline limestones and 

calcareous sandy marls. The limestone of this formation was referred by Hilgard to the Ripley 

(Cretaceous), but later investigation by Harris and others has, on paleontologic evidence, 

placed it in the :Midway. The limestone has a maximum thickness of 20 feet near the town 

of Ripley. It is overlain by 20 to 30 feet of reddish to yellow sandy marl containing lime carbonate and is slightly fossiliferous. The reddish color is due to a large amount of iron oxide. 

The Clayton outcrop forms a narrow strip of territory from 2 to 6 miles wide, lying just west 

of the Ripley (uppermost Cretaceous) area. The line of the New Orleans, ::VIobile & Chicago 

Railroad approximately follows the outcrop from Middleton, Tenn., to Houston, Miss., where 

the outcrop turns in a southeasterly direction west of Starksville and Macon and passes into 

Alabama southeast of Scooba.c 

In Mississippi the calcareous sandy marls of the upper Clayton are overlain by 75 to 100 

feet of gray nonfossiliferous clay, which forms the well-known" Flatwoods" area, extending from 

Tennessee into Alabama. To this clay Crider applied the name Porters Creek clay, originally 

used by Safford in Tennessee. It corresponds approximately to the Sucarnochee and N aheola 

formations of the Alabama section. 

The Midway group is represented in Tennessee by the Porters Creek formation as described 

by Glenn. 369 Harris presents m his monograph on the Midway, already cited, definite evidence 

that the Porters Creek clay of Safford included Midway. According to Glenn, the Porters 

Creek formation rests unconformably on the Ripley (Cretaceous). He says: 369b 

a The Tertiary descriptions for Georgia are based on a manuscript furnished by Otto Veatch, who has since published a report by himself and L. IV. Stephenson. 843 The paleontologic determinations and correlations were made 

by T. W. Vaughan. 

b Smith, E. A., Johnson, L. C., and Langdon, D. W., Report on the geology of the Co2stal Plain of Alabama: Geol. 

Survey Alabama, 1894, p. 369. 

c Descriptions of the Tertiary formations of Mississippi are modified from A. F. Crider's "Geology and mineral 

resources of Mississippi" (Bull. U.S. Geol. Survey No. 283, 1906) and A. F. Crider and L. C. Johnson's ''Summary of 

the underground water resources of Mississippi" (Water-Supply Paper U.S. Geol. Survey No. 159, 1906). 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 733 

"The formation is composed mainly of a fine-grained clay that is very dark gray or in places 

almost black when wet, but which becomes a light gray on dry.ing. It is familiarly known in 

the region as soapstone. Interbedded with this clay are sometimes found, especially in the 

lower part of the formation, beds of fine micaceous silty sands, which are usually indurated to 

soft sandstones. The lower part of the formation also contains interbedded with the gray clay 

and micaceous sand beds of greensand that may contain enough calcareous matter to cement 

certain layers into pure limestone. The calcareous matter has doubtless been derived from 

marine shells, the hollow impressions of which are abundant in some of the more calcareous 

beds. Such beds have been found near the base of the Porters Creek formation at intervals 

from a point just east of Middleton, Tenn., nearly to Paducah, Ky." 

The thickness of the formation is about 175 feet, and Glenn states that it "outcrops immediately west of Ripley in a belt about 8 miles wide in southern Tennessee, but averages only 

about 4 miles in width across the State. In Kentucky it widens out again, reaching 10 or 12 

miles in northern Calloway County. The outcrop narrows much as it curves westward beyond 

Paducah and is concealed by the alluvial deposits of Ohio River before crossing the Illinois. 

In Illinois it is known to outcrop only along the bank of the Ohio, at Caledonia Landing, and 

for some distance to the north toward Grand Chain. The exposures are for the most part poor, 

however, and its identification is made partly by a few indistinct fossil casts but mainly by the 

presence of greensand, which is absent from the Ripley below and the Lagrange above but 

which is found in the lower part of the Porters Creek. Farther west, across southern Illinois, 

its outcrop is obscured by either the Lafayette gravels and the loess or by the alluvial deposits 

of the. Cache and Mississippi River bottoms." 

Shepard 737a states that the Porters Creek formation "has been identified in Missouri wells 

at but one point. It was reached in the Morehouse well at a depth of 248 feet, where it consisted of 197 feet of bluish gumbo." 

Wilcox group. 404, 405-This group takes its name from Wilcox County, Ala., where unusually 

good exposures of it are recorded. In that State it forms the most massive of the Eocene 

groups, having a thickness of probably not less than 900 feet. It also presents a great variety 

in lithologic character and in fossil contents. In general terms the Wilcox strata are crossbedded sands, thin-bedded or laminated sands, laminated clays, and clayey sands, with beds 

of lignite and lignitic matter. · With these are found, interbedded at several horizons, strata 

containing marine and estuarine fossils. The fossil-bearing beds form the basis for the separation of this group into four formations, which Smith 749a describes as follows: 

"The lowest formation of the Wilcox group, the Nanafalia, overlies the Naheola formation 

of the Midway and maintains a tolerably uniform thickness of about 200 feet entirely across 

the State. These beds are mostly sandy but contain great numbers of the shells of a small 

oyster, Gryphcea thirsce. Near Alabama River and for a short distance to the east a gray siliceous clay with a tendency to indurate into a tolerably firm rock resembling very closely some 

of the strata of the Tallahatta buhrstone of the Claiborne group, * * * is a characteristic 

feature of the whole section. At the base of the oyster-shell beds there are, at certain localities, 

other fossiliferous beds containing a great variety of forms. 

"At the bottom of the .Nanafalia formation there is a bed of lignite, 5 to 7 feet thick, which 

may be traced across the country from Tombigbee River into Pike County, where it is well 

exposed ncar Glenwood station, not far from J'roy. 

·"The Tuscahoma formation, which overlies the Kanafalia, is about 140 feet thick and 

consists mainly of gray and yellow cross-bedded sands and sandy clays, generally poor in fossils except at one horizon, which is typically exposed at the locality from which the name is 

taken and at Gregg's and Bell's landings on Alabama River. 

"Above the Tuscahoma is the Bashi formation, which averages perhaps 80 feet in thickness. It is composed of the sands and sandy clays common in the Tertiary. It is distinguished by a characteristic bed of highly fossiliferous greensand with associated beds of lignite 

immediately below it. By these features the Bashi may be easily identified across the width 

of the State. The best exposure of the fossiliferous greensands of this formation is at Woods 

Bluff, on Tombigbee River. · 
734 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

"The Hatchetigbee formation, the uppermost formation of the Wilcox group, is composed 

of beds of brown, purple, and gray laminated sandy clays and cross-bedded sands abounding 

in characteristic fossils. It is about 175 feet thick in the vicinity of Tombigbee River, but it 

thins to the east, though otherwise maintaining its distinctive character. These beds have 

been named Hatchetigbee from a bluff on Tombigbee River." 

The Wilcox group extends eastward into Georgia, where it has not been subdivided into 

formations and has a small areal distribution. It is best exposed in the bluff of Chattahoochee 

River at Fort Gaines and probably continues northeastwa,rd to Flint River, but it is not easily 

differentiated from the Midway, except at Fort Gaines. At Fort Gaines the Wilcox and Midway are separated by a distinct erosion unconformity·represented by old potholes in the limestone of the :Midway filled by black sandy clay of the overlying formation. Evidence of this 

erosion unconformity has not been observed farther east, but this may be due to the imperfection of the natural exposures of the strata. The contact with the overlying Claiborne, where 

observed, is generally an undulating line of small pebbles or a stratum of coarse sand, and 

there is no physical evidence of any considerable time interval between the deposition of the 

two. According to Veatch-

"Along Chattahoochee River the formation is made up of a sandy glauconitic calcareous 

shell marl, in places indurated, overlain by dark laminated, often lignitic sandy clays, some 

beds of which are consolidated into mudstone. To the east, in Randolph County, appears 

glauconitic clay like fuller's earth, but near Flint River the formation is chiefly sand, in which 

there are massive beds of white clay. 

"The thickness lying between the Claiborne and Midway at Fort Gaines is about 75 feet. 

The maximum thickness at any place over the area of outcrop is probably not more than 150 

feet. This is not in agreement with the thickness on the Chattahoochee, estimated by Langdon a at 402 feet, but in view of the recent determination of strata of Claiborne age bin the upper 

part of the bluff at Fort Gaines, it is not improbable that a portion of Langdon's 'Lignitic' 

belongs to the Claiborne formation." 

No outcrops definitely known to represent the Wilcox group occur between Flint River in 

Georgia and Santee River in South Carolina. In the latter State, on Dr. W. S. Boyd's plantation (the old Gourdin plantation), Sloan collected from a silicified rock fossils characteristic of 

the Nanafalia formation of the Wilcox group. For the formation containing these fossils Sloan 

has proposed the name Williamsburg. It has probably been identified at Manning. 

West of Alabama, in Mississippi, the Wilcox group has not been subdivided into formations 

and is known as the Wilcox formation. In this State it is of a more or less sandy character 

throughout. Crider and' J ohnson 179a say: 

"The coarse-grained, unconsolidated sand beds are often interbedded with seams of lignite 

and white and chocolate-colored clays. The clays of the upper division, as at Grenada, are 

very dark and may properly be called shale. In the eastern half of the area loosely bedded 

sands predominate. The western portion, which is a series of irregularly cross-bedded sands 

and sandy clays, is separated from the eastern by a more or less regular line of white and 

chocolate-colored clays, which are used for making stoneware. 

"The thickness of the group is estimated from the width of the outcrop to be 750 to 800 feet. 

"The Wilcox covers the largest territory of any formation in northern Mississippi. It occupies the entire area lying between the Porters Creek outcrop and the bluffs on the eastern rim of 

the Yazoo Delta as far south as Grenada. The west edge south of Grenada is a line extending 

southeast 6 miles east of Winona, west of Philadelphia, and southwest of Meridian." 

In Tennessee, Kentucky, and southern Illinois the deposits of Wilcox age are included in 

the Lagrange formation of s .. afford, redescribed by Glenn. Harris 404 has given a resume of the 

evidence on which the determinations of the Wilcox age of the strata are based. It seems 

a Smith, E. A., Johnson, L. C., and Langdon, D. W., Report on the geology of the Coastal Plain of Alabama: 

Geol. Survey Alabama, 1894, p. 369. 

b Determined by T. W. Vaughan. 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 735 

probable that the Lagrange includes more than the ·wilcox, probably beds of Claiborne age, and 

perhaps some as late as Jackson, as the formation includes all the beds between the Porters 

Creek clay below and the Lafayette above. The following description of the Lagrange formation 

is adapted from Glenn: 369 

The formation consists of interbedded sands, clays, and lignitic material. Much the larger 

part is sand, which is mostly fine grained, though here and there throughout the formation 

beds of medium or coarse sand or even gravel may be found. Such coarser beds do not seem 

to be continuous over any large area. 

The sands exposed to view are usually strongly cross-bedded and were deposited under 

brackish water in a sea characterized by strong and ever varying currents. The clays of the 

Lagrange vary from pure, fine-grained plastic material to sandy, silty clays that are in places 

dark from organic matter or black from lignite. The clays of the lower part of the formation 

are characteristically fine grained, pure, plastic, and either very light colored or white. Chemical1y they are highly siliceous. The plastic siliceous clays occur as lenses embedded in the sands 

and outcrop in a belt along the eastern part of the Lagrange area in both Tennessee and Kentucky. Many of the beds contain great numbers of beautifully preserved leaf impressions, and 

numerous collections of these remains have been made. It is entirely possible or even probable 

that the upper part should be separated from tht; middle and lower parts and after very detailed 

work criteria may be forthcoming for this discrimination. At present it is impracticable and 

all the beds are lumped together, though certain facts render it probable that the upper clay 

is considerably younger than the plant-bearing clays in the lower part of the formation at Grand 

Junction, Tenn., and elsewhere. Lignitic material is found throughout the formation but is 

more abundant in the upper part. Glenn gives the maximum known thickness as 963 feet. 

The eastern edge of the Lagrange formation extends from the southwestern part of Hardeman County, Tenn., north-northeastward through Chester, Madison, Henderson, Carroll, and 

Henry counties, Tenn., and southwestern Calloway, northeastern Graves, middle McCracken, 

and northern Ballard counties, Ky. It then passes westward into Pulaski County, Ill., not 

far south of Caledonia Landing. It is not possible to follow it westward across Pulaski and 

Alexander counties because it is concealed beneath later deposits. 

Shepard 737 reports the Lagrange formation from wells in Caruthersville and Morehouse, Mo. 

Claiborne group.-This group, which overlies the Wilcox, is easily divisible in Alabama into 

three formations, the lowest being the Tallahatta buhrstone, the middle the Lisbon formation, 

and the upper the Gosport sand. Smith 749b describes the Tallahatta as follows: 

"The Tallahatta buhrstone, in the western part of the State, is predominantly composed 

of aluminous sandstone or siliceous claystones. They vary slightly in composition but are 

always poor in fossils except the microscopic siliceous shells of marine diatoms and Radiolaria. 

To the east the percentage of clay decreases, the rocks becoming more calcareous and fossils more 

abundant, and in place of the silicified shell casts of the Tombigbee and Alabama drainage 

basins are extensive beds of shells, mostly oyster shells. The thickness of the buhrstone varies 

from 400 feet in the western part of the State to 200 feet in the eastern part. In the western 

part of Alabama and still more in Mississippi, beds of fossiliferous greensand are abundant in 

both the Tallahatt'1 and in the Lisbon strata of the Claiborne. The decay of the greensands has 

in many places given rise to the accumulatiOn of deposits of brown iron ore. The Tallahatta 

buhrstone as here defined is the equivalent of the Siliceous Claiborne of Hilgard." 

The Lisbon formation lies between the Tallahatta buhrstone and the Gosport sand and consists of about 115 feet of calcareous clayey sands and sandy clays, generally fossiliferous. It is 

thus described by Smith.7490 

"The lower half of these beds contains a great number and variety of well-preserved shells; 

in the upper half the shells of Ostrea sellceformis and several species of Pecten greatly preponderate over other forms. The most characteristic exposures in Alabama of these beds, which are 

the equivalents of Hilgard's Calcareous Claiborne, are at the Claiborne and Lisbon bluffs on 

the Alabama River." 
736 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The Gosport sand, according to Smith/490 "so far as yet known,. does not appear in any othei' 

of the Gulf States but embraces the strata of the Claiborne group lying between the top of the 

Lisbon and the base of the St. Stephens. The beds are in general highly glauconitic sands about 

30 feet in thickness at the Claiborne and Gosport bluffs and include the fossiliferous greensands 

which have made the name Claiborne famous and which have furnished the greater part of the 

Claiborne fossils described and figured by Conrad and Lea. While this division, as above mentioned, is not known in Mississippi, Louisiana, or Texas, yet its importance in Alabama, from 

the historical point of view and because of the great number and variety and beautiful state of 

preservation of its fossils, is such as to compel mention and a distinct name. This member of 

the Claiborne group has been observed at a number of localities in Monroe, Clarke, Choctaw, 

and Washington counties. The name is from Gosport, a landing on the Alabama River a few 

miles below the Claiborne Bluff." 

In Georgia,S43 although in a general way the correlatives of the formations of the Claiborne 

group in Alabama may be recognized, the extension of the formational nomenclature used in 

that State is inappropriate, for the group is not naturally divisible into the same units. The 

divisions recognized are the Barnwell sand and the McBean formation, with the Congaree clay 

member at its base. 

·The McBean formation rests unconformably upon strata of Lower Cretaceous age east of 

Ocmulgee River, and tongues of the formation extend to the crystalline rocks of the Piedmont 

area. Between Flint and Chattahoochee rivers the McBean rests upon the Wilcox formation, 

with evidence of an erosion unconformity along Chattahoochee River in the vicinity of Fort 

Gaines. In eastern Georgia the formation is overlain by the Barnwell sand, the relations 

between the two formations being somewhat obscure. Along the northern margin of the areal 

occurrence of the Barnwell sand there is evidence of an unconformity of slight time importance, 

but farther south the sand seems to rest upon the McBean formation with conformable relations. 

It seems probable that near the close of McBean time there was an uplift which brought the 

northern margin of the area of Claiborne deposition above sea level, permitting erosion to take 

place along the margin of the emerged area, while deposition continued in the area which 

remained under water. The formation consists mainly of clays, in places having the character 

of fuller's earth, shell marls, sandy limestones, or calcareous glauconitic sands. The maximum 

exposed thickness of the formation occurs at Shell Bluff, on Savannah River, where 115 feet of 

strata were measured. Outcrops of the formation occur in an extremely irregular belt that 

extends entirely across the State and ranges from a few miles to 25 miles or more in width. 

East of Flint River exposures are known in Columbia, Richmond, Burke, McDuffie, Jefferson, 

Glascock, Washington, Baldwin, Wilkinson, Jones, Twiggs, Bibb, and Houston counties. 

There are also exposures on Flint River in eastern Sumter county and along Chattahoochee 

River from Fort Gaines southward. · 

The Congaree clay member in eastern Georgia rests directly upon the Lower Cretaceous, 

the contact being marked by conspicuous erosion unconformities. It is conformably overlain 

by the clays and marls of the McBean formation or by the B·arnwell sand, either passing into 

tl1e latter by gradation or in some exposures being separated from the former by unconformities. 

Lithologically the Congaree clay member consists of fuller's earth in which are small lenses and 

pockets of sand; in some places it contains large amo~nts of disseminated lignitic matter and 

thin beds of lignite. The thickness of this member is at least 100 feet. There are numerous 

outcrops of tbe Congaree clay member from Grovetown southwestwar·d along the "fall line" 

to Bibb and Twiggs counties. It is confined to the northern part of the area of the outcrop of 

the McBean formation, but no sharp lines separating the member either from the marls of the 

McBean formation or from the overlying Barnwell sand can be drawn. Clays and fuller's 

earth of the same general character as the Congaree clay member also occur in the vicinity of 

Chattahoochee River near the northern margin of the area of outcrop of the McBean formation. 

The Barnwell sand directly overlies the McBean formation and is in contact with both the 

mf1rls and the Congaree clay member. Along the northern margin of the Barnwell sand area 
EARLIER 'l'ERTIARY (EOCENE AND OLIGOCENE) 737 

there is evidence of a local unconformity with the underlying McBean formation, but farther 

south the relations are conformable. The Barnwell sand is overlain by the Jackson formation, 

but as the 'exact contact between the two has nowhere been observed the nature of the contact 

is not known. In Burke and Screven counties_the formation IS overlain by the Vicksburg formation and in places questionably by the Chattahoochee and Alum Bluff formations. In the 

eastern part of the State the Altamaha (Lafayette~) formation probably origrnally covered a 

large part of It. The Barnwell sand consists largely of u,nconsohdated red and varicolored sands 

With solll:e tlun layers of sandstone, quartzite, siliCified lrmestone or flint, and siliccqus limonite. 

The sands, especially where weathered, are somewhat similar in appearance to the red residual 

sands of the VIcksburg formation. The maximum measured thickness of the Barnwell sand is 

105 feet. East of Ocrnulgee -River the Barnwell sand is practically coincident in distribution 

With the Claiborne group as a whole. The formation overlies both the marls and the clays 

of the McBean formatiOn and extends to the "fall line." It is probable that red sands between 

Flint and Chattahoochee rivers belong to this formation, but as yet no positive statement can 

be made. 

In South Carolina the Claiborne group attains an extensive development, and Sloan 744ct. 

has applied a number of names to its local phases, some of which are of considerable importance. 

The names he proposed are Oongaree, Warley Hill, Oawcaw, Santee, Barnwell, and Mount Hope. 

Near Savannah River the successwn of material is similar to that m Georgia At the base are 

siliciiled clays, fuller's earth, the Congaree shales of Sloan; these are overlarn by glauconitic 

sandy marls, locally with silicified shells and buhr rock, and calc~reous beds, the Cawcaw shales 

and marls of Sloan, which are equivalent to his Warley Hill marl, San!ee marl, and Mount 

Hope marl of the Santee area and whiCh are succeeued by calcareous beds containrng rn their 

lower portion large numbers of Ostrea georgiana, these beds in turn being overlain by red sands, 

the typical Barnwell buhr sand of Sloan. 

In the regwn of Santee River the geologic section is decidedly different in some respects from 

that of Savannah River. The Oongaree shales of Sloan can be identified, overlain by glauconitic, 

more or less calcareous sands (the,Warley Hill of Sloan), which is overlarn by a soft lrmestonc 

(the Santee marl of Sloan), and this is succeeded by Sloan's Mount Hope, a limestone largely 

composed of Bryozoa, among winch are mollusks of Claiborne age. 

In Mississippi the Claiborne is divisible on hthologiC grounds into three distinct formations. 

The lower of these is the Tallahatta buhrstonc, which is overlain by the Lisbon formation, and 

at the top is the Cockfield formation. 

According to Crider and Johnson/70b the Tallahatta buhrstone, "called 'siliceous Claiborne' by H1lgard, consists chiefly of glaucomtic coarse-grarned micaceous sands tome that is 

almost quartzite The estimated thickness is 350 feet. The formation outcrops in a belt o'f 

territory between the Wilcox and Lisbon beds and vanes rn Width from 10 miles in northeastern 

Clarke County to 30 miles in Leake and Wrnston counties. The eastern hne of outcrop is traceable from the Alabama lmc 4 miles south of Hurricane Creek post office to Eastville; thence it 

swings southwest nearly to Sterling, south of Mendian, thence It bends northwest past Battlefield, Philadelphia, Plattsburg, Hinze, and French Camp, 6 miles east of Wrnona, and west of 

Grenada. No trace, of the Tallahatta has been found north of Yalobusha River. 

* * * * * * * * * "Above the Tallahatta is a series of beds which Hligard called 'calcareous Claiborne' and 

w'hich will be termed the Lisbon formation. The series is about 150 feet thick and is compose<l 

of calcareous sands and laminated and ligmtic clays. The character 9f the surface is little 

affected by the Lisbon, which is almost everywhere overlain by the Lafayette. In Alabama the 

area underlain by this formation is limited in extent, but. 1n "M1~'l1ssippi it widens out and occupies the territory from southeastern Clarke to southern Carroll County, varying from 5 to 25' 

miles in width." · · 

H1lgard 438ct has described "beds intervening between the Claiborne and Jackson groups" 

These beds arc exposed where the Qmtman and Winchester road crosses Coonupy Creek, on t~1e 

17 
738 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

banks of Chickasawhay River due west of the locahty just mentioned, and at other places in 

the same VIcinity. They also outcrop at Garlandsvillc, Jasper County, and extensive beds of 

earthy hgmte underlie th'c marine fossiliferous Jackson at Jackson, M1ss. At the latter place, 

"in the penitentiary well after passmg through 32 feet of surface matenal and fossiliferous 

strata of the Jackson age, hgmtw clays were penetrated for 418 feet, after wh:tch a bed of 

shells 20 feet thick, extremely rich in greensand, was passed through mto water-bearing sand." 

The hgmtw sands and clays mtervemng between the marme fossiliferous Jackson and the 

marrne Clai"J?orne occupy precisely the stratigraphic positwn of the Cockfield formatwn of 

Louisia,na; and the use of that name is extended so as to apply ·to them. 

·Jack'songroup.-This group, whwh Is called a formatwn where not subdrv,Ided, has its 

typical outcrop in the VIcimty of Jackson, Mtss, from whtch place It takes its name. 

,' , ~Irr }.i.illssissippi, accordmg to Crider and Johnson,179c "the essential matenals of the Jackson 

group are·gray calcareous and hgmtw clays and sands. The outcrop occupies a belt of country 

10 to 30 m'lles .WJde, extendmg southeast and northwest across the State fro~ Yazoo to the 

Alabama lme north of Waynesboro The area Is known as the 'central praine.' * * * 

"The Jackson has usually been described as 'marls' and clays, but recent mvestigatwns ' 

along the line of contact With the VIcksburg have shown that there are between 50 and 75 feet 

of yellow, gray, or whtte siliCeous sand at the top of the Jackson. Whether from a paleontologic 

standpomt this should be considered Jackson or VIcksburg we are unable to say, since no fossils 

have been found in the sands They are regularly stratified, showing that they were deposited 

in a qmet sea with little or no cl!rrent In places near the surface the sands are slightly cemented 

With iron oXIde, causmg some layers to resiSt eroswn more than others." 

· For Alabama Simth 749d says· "Above the Clatborne, and const1tutmg the uppermost 

member of the Eocene in Alabama, is the St. Stephens limestone, equivalent m part to the 

VIcksburg hmestone and in part to the Jackson hmestone of MISSISSippi. In Alabama these 

two formatwns blend' so dompletely that it has been impossible to draw clearly the line of 

demarcatwn between them,~ and:·the'St. Stephens is therefore mtended to include the Alabama 

representatives of both. · Immediately overlying the Claiborne foss1lrlerous sands, at many 

points in Clarke, Choctaw, and Washmgton counties, is an argillaceous hmestone closely 

~resemblm~ the Selma chalk and like it g~vmg rise to_nch black limy solls. The fossils of this 

bed show that it is probably of Jackson age,: but the great mass of the St. Stephens formatwn, 

between 200 and 300 feet thiCk, consists of a hmestone of a considerable degree of purity in 

which the ever present foss1l is a nummuhtic shell, Orbitoides mantelli. Other shells also abound, 

but this is characteristic." 

More detailed paleontolo~:,ric investigation in Alabama will probably differentiate the 

Jackson and Vicksburg. This opinion is borne out by some incomplete and unpublished 

studies of Vaughan. 

Veatch states that "m Georgia the area underlain by the Jackson formation, so far as 

known, 1s very small. The largest area is in Houston, Twiggs, and Pulaski counties. There 

is an 1solated occurrence at Rich Hill, Crawford County, one on Oconee RIVer in Johnson 

County, and probably one on Chattahoochee River near Alaga, Ala. 

"The formatiOn Is the uppermost Eocene exposed in Georgia and lies directly beneath the 

VICksburg~an Ohgocene. No evidence of a tmie interval between the depos1twn of the two 

has been observed, and there seems to have been no interruptiOn in the sedimentatwn, although 

there arc htholog1c differences. While the formatwn is known to overhe the Claiborne, contacts 

between the two formatwns have not been discovered. , The Jackson at Rich Hill, Crawford 

County, rests upon lower Cretaceous strata. 

"The Jackson consists mainly of white or cream-colored mass1ve-bedded hmestone, overlain by calcareous, glaucomtic, or sandy lammated clay. The limestone 1s highly fossiliferous, 

and m places the rock IS made up almost ent1rely of a friable mass of Bryozoa and shells. 

"The thickness of the formation can not be determmed With much aecuracy, as the hne 

of·contact between it and the Claiborne or underlymg formation has not been defin1tely located. 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 739 

The formation has a low southward dip and the width of the outcrop is only a few miles, so 

that the total thickness probably does not exceed 150 or 200 feet." ' 

On the South Carolina side of Savannah River, at Johnson's Landing, are exposures of 

silicified limestone which is replete with Bryozoa and contains a few specimens of Pecten perplanus. This rock may belong to the Jackson, but in this region the exposures are poor and 

fossils are rare and not well preserved, rendering it difficult to discriminate between Jackson, 

Vicksburg, and Chattahoochee. 

The thick beds of soft limestone exposed along Ashley and Cooper rivers in the vicinity 

of Charleston, called by Sloan 744e the Ashley-Cooper marl, are referable to the Jackson group. 

The marl is green-drab or gray-green and slightly plastic when wet, but is lighter in color and 

more pulverulent when dry. The marl along Cooper River usually contains less than 2 per: 

cent of calcium phosphate; that along Ashley River may contain as high as 15 per cent. The 

formation exceeds 100 feet in thickness. 

OLIGOCENE. 

Vicksburg group.-This group takes its name from the city of Vicksburg, Miss., in the 

vicinity of which are excellent exposures, especially along the bluffs of Mississippi River. The 

outcrops of the group extend from Louisiana to Savannah River, except where they are intersected by stream valleys. In Mississippi it consists of a semicrystalline limestone in beds 

varying from 1 foot to 3 feet in thickness, alternating with beds of sandy fossiliferous marl 

of about the same thickness. Usually the beds of limestone near tho surface are more or less 

affected by weathering and have therefore become soft and locally yellow, but below the zone 

of weathering there is in many places hard blue rock. The beautiful, well-preserved fossils 

of the Vicksburg are found mostly in the beds of marl. The thickness of the formation is between 

65 and 75 feet in Mississippi. This formation marks the end of the marine conditions of the 

Tertiary in western Mississippi. Its outcrop occupies a narrow band just south of the Jackson 

area and extends across the State from the type outcrop at Vicksburg through Warren, Hinds, 

Rankin, Smith, Jasper, and Wayne counties into Alabama. 

In eastern Mississippi near Hiwannee, on Chickasawhay River, the base of the Vicksburg, 

immediately overlying the Jackson, bears fossils of an older facies than those at Vicksburg and 

constitutes the Red Bluff group of Hilgard, which is composed of calcareous clays and some 

limestone beds. 

The Vicksburg continues across southern Alabama, where it has not been differentiated 

from the Jackson (uppermost Eocene), the two being included in the St. Stephens limestone. 

It seems, however, that by more detailed studies the Vicksburg and Jackson can be discrimmated. 

The Vicksburg part of the St. Stephens limestone consists of a limestone of a considerable degree 

of purity, in which the nummulitoid fossil Orbitoides is persistently present. The rock is 

largely a foraminiferal limestone. Other fossils are present, but this one is characteristic. In 

some places this limestone is hard and' capable of polish, but usually it is soft and easily cut 

with a saw. Its thickness is between 200 and 300 feet. It outcrops across Clarke, Choctaw,. 

and Washington counties and extends eastward into Georgia and southward and southeastward 

into Florida. 

In Georgia the Vicksburg, according to Veatch, "consists mainly of white, massive-bedded 

limestone interbedded with sand and clay. The limestones are extensively silicified and in 

many places do not appear at all at the surface but are concealed by red coarse-grained 

argillaceous sand and are represented by residual flint. The limestone is generally soft but in 

a tew places is exceptionally hard and crystalline and very fossiliferous, Orbitoides, Bryozoa, 

pectens, and their fragments forming nearly the whole of the rock. 

"The thickness of the Vicksburg in the western part Of the State, to judge from well records 

is hardly more than 300 feet, and there is no evidence that it is likely to exceed this at the east: 

"The Vicksburg formation in Georgia underlies a large area lying mainly west of Flint River. 

East of Oconee River the formation is usually concealed by later formations and in Screven 

and Burke counties only small areas are known." 
740 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

In Florida the Vicksburg group is tentatively subdivided into three formations-the 

Marianna, "Peninsular," and Ocala limestones. The Marianna limestone occurs in Florida 

mostly west of Apalachicola River; the "Peninsular" limestone constitutes that portion of the 

Vicksburg group underlying the Ocala limestone in Peninsular Florida and is largely con..:. 

temporaneous with the Marianna limestone. Matson and Clapp ssoa give the following 

description: 

"The Marianna limestone is thought to be the stratigraphic equivalent of the upper part 

of the bluff at Vicksburg, Miss., and some of the wells in west Florida enter beds of sand and 

clay which probably represent older horizons, but the stratigraphic relation of the formation 

to these older beds can not be determined. In west Florida, where this formation is recognized, 

it is unconformably overlain by beds belonging to the Apalachicola group or by post-Pliocene 

formations. 

"The Marianna and 'Peninsular' formations consist of soft, porous white or light-gray 

limestone, sometimes resembling marl, especially when partly decomposed. Some bands of 

darker-colored dense limestone are reported at various localities where these formations have 

been penetrated by drilling, and nodules and layers of chert are common throughout them, 

but chert beds are especially prominent in certain horizons. The chert beds are usually darker 

in color than the limestone and range in thickness from a fraction of an inch to 12 or 15 feet. 

In some localities as many as six or seven successive beds of chert have been encountered in a 

single well. In general the heavier layers are more persistent, and it is usually the chert which 

forms a nearly water-tight cap to the artesian-water beds in these formations. Certain horizons 

are abundantly fossiliferous, containing innumerable specimens of Orbitoides and shells of 

mollusks, such as Pecten poulsoni, etc. At several localities the rock is so soft that it can be 

cut into blocks with a saw, and upon exposure to the weather these blocks harden rapidly, 

making a very fair quality of building stone. Beds of sand, sometimes 10 feet or more in 

thickness, are reported in some of the wells which penetrate this formation. In general, these 

sands appear to be most numerous in the northwestern part of the State. 

"The thickness of the 'Peninsular' limestone and the Marianna limestone appears to be 

exceedingly variable. The thickness given by Foerste, from his investigations of the Vicksburgian limestones in southwestern Georgia and the adjacent part of Florida, is 220 feet, and 

probably this may be regarded as the approximate meas~re of the thickness of the Marianna. 

On the basis of well borings Dr. Dall estimates the thickness to be over 350 feet at Gainesville, , 

212 feet at Lake Worth, and 1,068 feet at St. Augustine. From recent examinations of well 

borings by Drs. Vaughan and Bassler, limestone of Vicksburg age is known to have a thickness 

of over 225 feet at Quincy, 250 feet at Alachua, and 325 feet at Bartow. Apparently there is 

a marked thickening of these limestones from the exposures of Georgia and Alabama southward. Of all the estimates given above the one at Gainesville is probably the most reliable, 

because the well is cased to the bottom." 

Rocks belonging to the Vicksburg group occur in deep wells on Key Vaca and Key West. 

The Ocala is described by Matson and Clapp ssob as follows: 

"The Ocala limestone lies stratigraphically between the 'Peninsular' and the beds here 

designated Apalachicola group. Lithologically it bears a strong resemblance to the underlying 

'Peninsular' limestone, with which it also has a close faunal relation. These facts have led to 

the conclusion that the two formations are conformable, and it has also been suspected that the 

Ocala limestone represented a local phase of the 'Peninsular.' While the two formations are 

probably conformable, the extensive distribution of nummulites of the Ocala limestone shows 

that it represents a widespread change in conditions and is not to be classed as a mere local 

phase of the underlying beds. 

"The Ocala limestone, as already noted by Johnson, is sometimes wanting, so that the 

overlying formations rest directly upon the 'Peninsular.' This relation was noted at several 

localities which will be mentioned. in discussing the younger formations. At present it is 

sufficient to note its absence and to suggest that since the Ocala limestone does not appear to 

be a local phase of the 'Peninsular,' there is probably a stratigraphic break between the rocks 

belonging to the Vicksburg and Apalachicola groups in the central part of the peninsula. 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 741 

"The Ocala limestone consists of a soft, porous light-gray to white limestone which bears 

a strong lithologic resembl1:1nce to the underlying 'Peninsular' limestone, but is distinguished 

from it by the included fossils. When slightly weathered the rock becomes light yellow and 

owing to its granular appearance is often regarded as sandstone. The removal of the calcareous 

material by the leaching action of underground water leaves a pale-yellow, more or less incoherent sand, containing a small percentage of calcium carbonate. When fresh the Ocala limestone is so soft that it is easily broken, but exposed surfaces often become hardened by the 

deposition of calcium carbonate from the waters which emerge along the outcrop. For this 

reason the rock frequently appears to be hard and firm. Its porosity and ready solubility 

permit the formation of numerous underground channels which are sometimes seen at the 

outcrop and are inferred from the presence of numerous sink holes. The rock contains 

an abundance of organic remains which are commonly preserved as casts. Nodules and 

large masses of chert are also common and in some localities a large part of the rock has been 

silicified." * * * 

"The greatest thickness noted during the recent field investigation was in a sink hole near 

Ocala, where the formation is exposed to a depth of about 40 feet without reaching its base." 

Apalachicola group.-The following descriptions are adapted or copied from Matson and 

Clapp. 5800 In Florida "the Apalachicola group includes a number of beds differing widely in 

lithological character, though they are recognized by their fossils as integral parts of a single 

group. While limestones and marls predominate, the group also includes beds of nearly pure 

sand and clay. The entire period of deposition appears to have been characterized by the 

accumulation of more or less terrigenous materials, and hence the limestones are usually rendered 

somewhat impure by an admixture of clay and sand. At certain times the conditions appear 

to have been especially favorable for the development of organic life, and some horizons, such 

as the Chipola marl member of the Alum Bluff formation and the 'silex bed' of the Tampa 

formation, contain very large faunas. 

''Owing to the lithologic variations and widely separated exposures, the exact correlation 

of the formations of this group is dependent upon their organic remains. While the paleontological studies, especially those made by Dall, have shed much light upon the stratigraphic 

relations of the different beds, there are still many points which can not as yet be fully decided. 

For this reason it seems best to retain the names of various beds and to indicate as far as possible 

their known relationships. The Apalachicola group is separated into four· formations-the 

Chattahoochee, the F{awthorne, the Tampa, and the Alum Bluff. There is, however, some reason 

for believing that the first three are, in part at least, synchronous, though exact equivalence is 

difficult to determine where outcrops are widely scattered and faunal variations are slight. 

The Alum Bluff formation is clearly younger than the Chattahoochee formation, upon which 

it rests." 

The Hawthorne formation, "according to Dr. E. H. Sellards, is a light-colored soft, porous 

limestone. The original building-stone quarry which is located near the station of Grove Park, 

about 3 miles west of Hawthorne, is now abandoned and is badly overgrown, so that the thickness 

of this limestone can not well be determined. At the old phosphate mine, which is at least a 

mile southwest of the stone quarry, the rock is a phosphatic conglomerate. At many localities 

the limestones of the Hawthorne formation are silicified, forming bowlders and beds of chert. 

This is a very common condition in the rock-phosphate region, where these limestones rest 

directly on those belonging to the Vicksburg group. 

"Beneath the phosphatic limestones of the Hawthorne formation are beds of sand, sandstone, or gravel, which are underlain by several feet of clay. The sand beds at some localities 

contain iron oxide which forms a coating on the grains of silica. The clays are greenish and 

locally sufficiently calcareous to be called a marl. The thickness of the Hawthorne formation 

varies greatly, the maximum amounting to approximately 95 feet. The three members of this 

formation with their maximum observed thicknesses, according to Dall, consist of greenish 

clay 70 feet, ferruginous yellow sandstone 4 feet, and phosphate rock 20 feet. The maximum 

thickness of the Hawthorne formation, as given by the same author, is 125 feet. However, 
742 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

over a large part of the peninsula, where the sole representative of the Hawthorne formation 

is the phosphatic or siliceous rock, the thickness is but a few feet. 

* * * * * * * * * 

"The Chattahoochee formation consists of light-calored limestones and marls, containing 

some thin beds of chert, clay, and sand. The colors vary from creamy white to light gray or 

green on recently exposed surfaces to light yellow, brown, or more rarely pink on weathered 

outcrops. Lithologically there is a gradation from nearly pure limestone to sands and clays, 

but in general the argillat;eous and siliceous limestones predominate, forming impure limestones 

or marls. The formation is in part composed of semicrystalline limestone, but soft, loosely 

coherent rock resembling an impure chalk is more common. ·while chert beds occur at various 

horizons, they are much thinner and less persistent than those of the underlying group. At 

times organic life appears to have been abundant and hence some layers are very fossiliferous, 

though the fossils are usually preserved in the form of imperfect casts and molds which have been 

left by the solution of the shells. 

. "Vaughan's observations along the Apalachicola River show that the Chattahoochee 

attains a considerable thickness near the type locality. 

"Well borings from Quincy indicate that the thickness of the Chattahoochee formation 

at that locality is slightly greater than 100 feet, but here, as elsewhere, it is difficult to determine 

the exact thickness of formations from well samples. The maximum thickness of the formation 

is probably double the figure given above and it may be even as great as 250 feet." 

The Tampa formation, named from the city of Tampa, has as its upper member "a wellstratified greenish clay containing some calcareous nodules and thin beds of limestone near the 

base. Scattered throughout the clay are many silicified corals, some of them having a diameter of 

2 or 3 feet. The clay is very plastic and hence is valuable for the manufacture of brick. Beneath 

this clay is the light-gray to yellow limestone which was formerly called the 'Tampa limestone.' 

The 'silex bed' represents a silicified zone in this limestone and is therefore a zone of replacement. This is well shown by some of the fossils, which have been only partially silicified, and 

by the presence of more or less unaltered carbonate of lime in the original rock. Small nodules 

of chert occur at other horizons in the limestone, and outcrops of the rock are often denser and 

ha:rder than exposures in quarries. Locally the limestone is hard enough to make a durable 

building stone. Fossils are abundant in some parts of the limestone, but they are largely represented by casts and molds, which have been left by the solution of the original shells. The 

'silex bed' contains numerous fossils which have been wholly or partly replaced by chalcedony. 

Resting upon the 'silex' at some localities is a siliceous residual material which was formerly 

thought to be infusorial earth but is now known to be weathered materia:! derived from the 

underlying rock. In such cases the action of the percolating water has removed the matrix, 

leaving many beautifully preserved pseudomorphs and casts of shells. These fossils are commonly composed of chalcedony which frequently exhibits the characteristic markings of the 

original shells. 

''Beneath the limestone beds is a greenish clay which commonly contains a considerable 

admixture of sand. This clay is very plastic and resembles the clay which overlies the limestone. 

Judging from well records, the deposit is homogeneous, but there is a possibility that the sand 

contained in the well samples may be derived from thin sand partings in the clay bed. 

"The information concerning the thickness of the Tampa formation is meager, but it is 

sufficient to fix the maximum thickne,;s at more than 130 feet. The clay bed at the top of the 

formation has a known thickness of 15 feet. The limestone between the 'silex bed' and the 

upper clay is about 40 feet thick. The thickness of the 'silex bed' varies considerably, ranging 

from about 4 feet to more than 10 feet. Beneath the 'silex bed' is a limestone which has a 

known thickness of 6 feet. The clay bed at the base of the formation has hem penetrated by 

two wells within 200 feet of each other, and the thickness varied from 41 feet to 64 feet. 

* * * * * * * * * 

"The Alum Bluff formation consists of marl, sand, and clay, which are sometimes fairly 

distinct but more often interbedded. Limestones also occur in the formation, but they are not 

extensively developed and usually contain enough earthy material mixed with the carbonate 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 743 

of lime to form marls. Shell marls with a calcareous or sandy matrix are common and they 

oft<Jn occur interbedded with nearly pure sand. In general the beds belonging to this formation 

are light gray, but occasionally shades of green or yellow prevail. * * * 

"The typical Alum Bluff formation consists of coarse light-greenish gray to white argillaceous sands, often showing cross-bedding and usually containing more or less interbedded 

clay and fuller's earth. One of the most characteristic features of the sands is the presence 

of innumerable flakes of white mica-the 'isinglass' of the well diggers. The change from the 

shell marls of the Chipola marl member is by a transition zone which contains some of the same 

species of shells which characterize the marls. This zone also contains nodules of calcium 

carbonate which often inclose fossils. The upper part of the sand is usually free from shells 

but occasionally contains impressions of leaves and fragments of plants. Locally the Alum 

Bluff formation contains some clay, and near Chattahoochee it consists of greenish sticky marl. 

"The fuller's earth has the appearance of a dense, hard fine-grained siliceous clay. It 

is thinly laminated and commonly light gray to greenish in color. Sand partings sometimes 

occur, but they are comparatively rare, the material usually being homogeneous. Beds of sand 

and clay arc commonly associated with the fuller's earth, the sections consisting of interbedded 

sand and clay. 

''The aggregate thickness of the Alum Bluff formation is at least 135 feet, but the maximum 

thickness of a single section is scarcely one-half that amount. It is doubtful if the total thickness is represented in any single section. The thickness of the sands of tho Alum Bluff formation at the typo locality is about 20 to 25 feet, but farther north, at Rock Bluff, Dall reports 

a maximum of 63 feet. The fuller's earth commonly occurs in beds of 2 to 10 feet in thickness 

associated with several feet of clay and sand or sandstone. In some places· two or more beds 

occur in the same section, separated by beds of sand and clay. Tho maximum observed thickness of fuller's earth in a single section is about 15 feet, and the aggregate thickness of the 

associated clays and sand which appear to belong to the same horizon is not less than 20 feet." 

Three members of the Alum Bluff formation have been recognized-tho Chipola marl 

member, the Oak Grove sand member, and the Shoal River marl member. 

''The Chipola marl member, named from Chipola River, forms tho basal portion of the Alum 

Bluff formation and rests conformably upon either the Chattahoochee or the Ha'Ythorne formation. At the type locality of the Alum Bluff formation it constitutes tho basal division of that 

formation, but farther north it thins and permits the sandy beds of the Alum Bluff tolap over 

on the Chattahoochee formation. 

"vVhen fresh this member consists of a light-gray to yellow marl, containing many shells 

and shell fragments. The matrix is composed of calcareous clay containing a small percentage 

of fine sand. When weathered the marl becomes dark yellow or reddish yellow from the presence 

of hydrated iron oxide. The character of the deposit indicates comparatively quiet water, with 

conditions especially favorable for the development of organic life. In some localities this 

horizon is represented by a very sandy marl." 

This member is not known to have a thickness of more than 15 feet and the average is 

probably only a few feet. The limestone belonging to it is so imperfectly known that a satisfactory estimate of its thickness is difficult to make. The maximum exposure which has been 

reported is about 10 feet. 

The Oak Grove sand member, named from Oak Grove, on Yellow River, has been correlated 

on paleontologic grounds by Dall with the typical sands of the Alum Bluff formation. This 

member consists of fine-grained light-gray to greenish sands containing many excellently preserved shells. As it is not fully exposed at the type locality, whore a thickness of only 2 feet is 

visible, it may attain a greater thickness. The fauna of the Oak Grove sand member is closely 

related to that of the Chipola marl member, but it contains large species of both Cardium and 

Lyropecten, which appear to foreshadow the largo species of those genera occurring in the Miocene 

marls. 

''The Shoal River marl member, which has recently been recognized by Vaughan, lies 

stratigraphically about 30 feet above the Oak Grove sand member. It thus forms the upper 

part of the Alum Bluff formation. In the section at Shell Bluff, on Shoal River, the lower sand 
744 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

represents the Oak Grove sand member and the upper fossiliferous marl horizon is the Shoal 

River marl member. Lithologically this member consists of interbedded greenish sands, clays, 

and marls. The color is usually greenish, oxidizing yellow, occasionally whitish or purplish, and 

the material varies in texture from fine clay to sand." This member is about 50 feet thick. 

In Georgia, according to Veatch, ''the area over which the Chattahoochee formation appears 

as a surface formation is small, being confined mainly to small exposures along streams and in 

lime sinks. 

"Erosion unconformities with the underlying Vicksburg have been noted in the vicinity of 

Bainbridge by Pumpelly and Vaughan. The Alum Bluff fmmation everywhere overlies the 

Chattahoochee and. there appears to have been a continuous deposition from the beginning of 

the Chattahoochee to the end of the Alum Bluff.· 

"The formation is, on the whole, calcareous and the rock varies from a compact pure 

crystalline limestone to earthy and m·gillaccous limestone and calcareous sand and sandstone. 

The strata are in places phosphatic, and the limestone at the base has been extensively silicified 

and contains a rich coral fauna. 

"The formation has a total thickness of about 100 feet in the gorge northwest of Faceville, 

Decatur County. No very rehable data arc at hand for estimating the thickness east and 

northeast of this point, where it is under cover of later formations. The thickness is not great, 

however, and is not likely to be in excess of 250 feet. 

"The Alum Bluff formation underlies a very large area in Georgia, extending northeastward, 

from Decatur County to Savannah River in Screven and Effingham counties, the eastern limit 

of outcrop being 50 or 60 miles from the coast. This formation overlies the Chattahoochee 

formation conformably. The line of division between the two is, in places, indefinite, as there 

is no apparent abrupt lithologic or faunal change from one to the other. In the Savannah and 

Altamaha river exposures small unconformities between the Alum Bluff and the Miocene were 

observed. This formation presents several different lithologic phases~sand and sandy laminated 

clay, fuller's earth, phosphatic sand, quartzite, silicified clay, and local limestone or calcareous 

layers and nodules. Greenish or drab argillaceous sap.d and fine-grained sandy laminated clay 

form the greatest portion of the strata. The maximum thickness of the Alum Bluff in southwestern Georgia is estimated at 150 feet. The natural exposures on Savannah River do not 

exceed 2.5 or 30 feet. It is not probable that at any place the thickness exceeds 250 or 300 feet, 

even where it is urrder cover of the later formations." 

Sediments of upper Oligocene age extend westward from western Florida to Mississippi 

River. The Apalachicola group, or marine upper Oligocene, has been identified by means of 

fossils in Alabama at Roberts and probably at Wallace. In wells at Mobile fossils characteristic of the Alum Bluff formation were encountered between depths of 1,250 and 1,550 feet; 

below these is limestone, correlated with the Chattahoochee formation. The marine upper 

Oligocene is not known west of Mobile, the sediments becoming estuarine in character as the 

axis of the }Iississippi embayment is approached. The unpublished results of the recent field 

work of Matson and the parallel paleobotanic studies of Berry have shown that the leaf-bearing 

clays and sandstones near Chicoria, Wayne County, 5 miles south of Florence, Rankin County, 

and Raglan, near 1IcCallum, Perry County, :Yiiss., are of upper Oligocene ago.a The exposure 

at Raglan (the Hattiesburg clays of L. C. Jc,hnson) appears to represent the top of the Alum 

Bluff of Florida, while the one near Florence is stratigraphically lower and perhaps belongs in 

the upper part of the Vicksburg group. The exposure of interbedded sandstone, semiquartzitic sandstone, an:d clay at Grand Gulf, 1Iiss., is, according to the available evidence, to be 

referred to the upper part of the lower Oligocene and is the ~fississippi representative of the 

Catahoula formation of Louisiana at the type locality. These estuarine or fresh-water deposits 

of clay and sandstone represent the basal portion of the Grand Gulf group of Hilgard/388 which 

according to his definition included the sandstone and clays lying between the Vicksburg below 

and the Lafayette above, but which is now known to be a series of geologic formations, including 

a Paleontologic determinations furnished hy E. W. Berry. 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 745 

those of lower and upper Oligocene, Miocene, and Pliocene age, with -perhaps some Pleistocene. 

The portions of the "group" later than the upper Oligocene will be referred to in Chapter XVII 

(pp. 806-813). The detailed tracing of the boundaries between the successive formations is 

now in progress by G. C. Matson. 

I 17-18, J' 18, K 18-19. NORTH CAROLINA TO MASSACHUSETTS, INCLUSIVE. 

The subjoined discussion of the Tertiary deposits of the northern Atlantic 

Coastal Plain has been prepared by William B. Clark and is based on a briefer 

statement 144 covering this region. 

The Tertiary deposits of the Atlantic Coastal Plain overlie the Cretaceous formations 

unconformably. They have been as a whole even less changed than the Cretaceous, although 

they present much the same complexity, owing to the variation in the angle and direction of 

tilting during the successive movements of the sea floor in Tertiary time. The sediments in 

general form a succession of thin sheets which are inclined seaward so that successively later 

formations are found toward the east. At no point do we find a continu:ous sequence of these 

formations, a condition which must be regarded as marginal and due to the transgression and 

retrogression of the sea along the coastal border, as continuous sedimentation must have been 

going on over a considerable part of the continental shelf. 

The Tertiary formations have variously transgressed the underlying deposits and at many 

points actually reach beyond them and rest directly on the crystalline rocks of the Piedmont 

Plateau. Similarly la"ter formations of the Tertiary have in many places transgressed the earlier, 

and the latest formation provisionally referred to the Pliocene has been found over wide areas 

resting on earlier Tertiary, Cretaceous, and crystalline rocks alike. 

The northern Atlantic Coastal Plain contains deposits that are referred to the Eocene, 

Miocene, and Pliocene epochs. The Eocene formations are best developed in Maryland and 

Virginia, although Eocene deposits of moderate areal extent are also known in New Jersey and 

North Carolina. The Miocene formations are most extensively developed in the drainage 

basin of the Chesapeake Bay in Virginia and l\faryland, but strata of that age also cover large 

areas in North Carolina and New Jersey. The marine Pliocene deposits are limited so far as 

known to North Carolina, although the Lafayette formation, of somewhat doubtful Pleistocene 

or Pliocene age, covers extensive areas in North Carolina, Virginia, and Maryland. North of 

these States only small remnants of the Lafayette have been found. 

Long Island and southern New England.-The Tertiary deposits of Long Island and southern 

New England are confined so far as known at the present time to a few localities on Long Island 

and the islands off the Massachusetts coast. The scarcity of the exposures and characteristic 

fossils has led to much doubt as to the age of the beds, although they have been generally 

regarded as .Miocene. The deposits have been studied chiefly by Shaler, 728• 729,730 Veatch,S37 

Fuller, and Crosby. 

On Long Island small eroded remnants of supposed l\fiocene strata have been found overlying the Cretaceous, and certain sandy beds penetrated in deep well borings in the vicinity 

of the city of Brooklyn have been thought to belong to the same horizon and have been 

tentatively referred to the Beacon Hill formation of New Jersey. 

The residual sandy strata overlying the Cretaceous deposits at Gay Head, Marthas Vineyard, and containing a meager fauna of supposed Miocene age have also been referred to the 

:Miocene and may represent the same horizon. Similar deposits are also reported from Block 

Island. 

New Jersey.-The Tertiary deposits of New Jersey comprise representatives of both the 

Eocene and the Miocene. Some of the Miocene deposits are evidently unfossiliferous, so that 

their position in the sequence of Miocene strata can not be clearly determined. Among those 

who have studied and described these deposits may be mentioned Cook/69 Whitfield, 926 

Clark,142, 145, 146, 152 and Salisbury.691 
.746 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The following scheme of classification has been proposed for the New Jersey formations: 

Miocene ...•...................................• _____ { S~hanseyd s

1

and a~d Deacon Hill formation. 

:>.lfkwoo ormatwn. 

Eocene. __ ... _ .. _____ .................... _______ .... _ . _Shark River marl. 

The Shark River, which is limited to a small area in eastern New Jersey, consists of' greensand marls and apparently overlies the Manasquan formation of the Upper Cretaceous conformably. The deposits are about 12 feet in thickness. The fossils are marine invertebrates of 

lower Eocene age. 

The Kirkwood formation consists of sands and clays which unconformably overlie the 

older deposits of Eocene arid Cretaceous age. It has a thickness of about 100 feet and contains 

in places a considerable fauna of marine invertebrates similar to the Calvert fauna of Maryland 

and Virginia. 

The Cohansey consists chiefly of buff sands, although sandy clays and coarse white sands 

are also found. It has a thickness of about 100 feet. No diagnostic fossils have been found. 

The Beacon Hill formation consists of gravel and sand and probably represents the shoreward phase of the Cohansey sand in the northern part of the New Jersey Coastal Plain. It 

has a maximum thickness of about 40 feet. No fossils have been found. 

The deep well borings near the coast have penetrated several hundred feet of characteristic 

Miocene sediments in which fossils that apparently represent the Calvert, Choptank, and St. 

Marys faunas 'of Maryland and Virginia are found. It is apparent that the Kirkwood formation represents the Calvert formation, but whether the Cohansey sand and the Beacon Hill 

formation should be regarded as Choptank, which they resemble lithologically, is impossible 

of determination in the absence of characteristic fossils. It has been suggested that the Cohansey 

and Beacon Hill may perhaps overlie all the Miocene formations of the Chesapeake region. 

Maryland and Delaware.~An extensive series of Tertiary deposits is found in Maryland 

and Delaware, including representatives of the Eocene, of the Miocene, and probably of the 

Pliocene. All the deposits, except the Pliocene, are highly fossiliferous and have been investigated by many students of geology and paleontology. Among those. who have studied the 

region may be mentioned Say/04 Conrad/68 Harris/00 McGee, 565a, 566 Clark,149• 150 Martin,t49 

Shattuck, 733• 734 and :Miller. 595• 

597 

The following scheme of classification has been adopted for the Maryland and Delaware 

Tertiary formations: 

Pliocene(?) ......... -.-.-.-_._ .Lafayette formation. 

Miocene ............ ------- ... _. Chesapeake group: 

St. Marys formation. 

Choptank formation. 

Calvert formation: 

Plum Point marl member. 

Fairhaven diatomaceous earth member. 

Eocene .................. ---- .... Pamunkey group: 

Nanjemoy formation: 

Woodstock greensand marl member. 

Potapaco clay member. 

Aquia formation: 

Paspotansa greensand marl member. 

Piscataway indurated marl member. 

The Aquia formation consists chiefly of greensands and greensand marls, in places highly 

calcareous and here and there argillaceous. These beds overlie the earlier deposits unconformably. The total thickness of the formation is about 100 feet. The Aquia formation has been 

divided into the Piscataway and Paspotansa members. The deposits contain a rich fauna of 

lower Eocene age. The formation is transgressed by the Calvert formation toward the north 

and disappears near the Maryland-Delaware line. 

The Nanjemoy formation consists of greensands, in many places highly argillaceous but 

less commonly calcareous than the Aquia formation, which it overlies conformably. The 
EARLIER TERTIARY (EOCENE AND OLIGOCENE.) 747 

maximum thickness of the Nanjemoy formation is 125 feet. It has been divided into the 

Potapaco and Woodstock members. It contains an extensive fauna of middle Eocene age. 

It is not known to occur on the eastern shore of Chesapeake Bay. 

The Calvert formation, which overlies the Eocene formations unconformably, consists of 

sands, clays, marls, and diatomaceous earth. These deposits have a thickness of about 200 feet.' 

The formation has been divided into the Fairhaven diatomaceous earth member and the Plum 

Point marl member. It contains an extensive marine fauna. 

The Choptank formation consists of sands, clays, and marls and has a total thickness of 

125 feet. An extensive marine fauna characterizes these deposits. 

The St. Marys formation consists of clays, sands, and sandy clays, the last typically greenish 

blue and bearing large quantities of fossils. The formation has a thickness of 150 feet. It 

carries a distinctive marine fauna. 

The Lafayette formation consists of clays, loams, sands, and gravels which are in many places 

highly ferru'ginous. The thickness is variable but in few places exceeds 50 feet. No characteristic fossils have been found in these deposits and there is much doubt as to whether they are 

of late Pliocene or early Pleistocene age. The formation covers a wide area on the southern 

peninsula of Maryland and is represented to the north, on the western shore of Chesapeake 

Bay, by many small outliers. It overlies the Miocene and earlier formations unconformably. 

"Virginia.-The Tertiary deposits of Virginia comprise strata of Eocene, of Miocene, and 

probably of Pliocene age. The Eocene and Miocene formations are highly fossiliferous. The 

geology and paleontology of the region have been studied by many investigators, among them 

Rogers, 676 Conrad/ 08 Clark/ 49•

150 1'1iller/ 95• 597 Berry, 75 and Gardner. 

The following scheme of classification has been adopted for the Tertiary deposits of Virginia: 

Pliocene ('') ...................... Lafayette formation. 

Miocene ........................ Chesapeake group: 

Yorktown formation. 

St. Marys formation. 

Choptank formation, probably present but does not outcrop. 

Calvert formation. 

Eocene ...... ,.------------- __ .... Pamunkey group: 

Nanjemoy formation: 

·woodstock greensand marl membAr. 

Potapaco clay member. 

Aquia formation: 

Paspotansa greensand marl member. 

Piscataway indumted marl member. 

The Aquia and Nanjemoy formations of Virginia are similar in their lithologic and faunal 

characters to the same formations in Maryland, the deposits being less highly calcareous in 

central and southern Virginia than in the valley of the Potomac. 

The Calvert formation in Virginia is similar in character to the same formation in Maryland. 

It disappears at the outcrop in south-central Virginia, owing to the transgression of the St. 

Marys formation. 

The St. Marys formation overlaps the Choptank formation near the Maryland-Virginia 

line and in Virginia directly overlies the Calvert formation unconformably. 

The Yorktown formation consists of sands, sandy clays, and marls. In many places the 

marls are highly calcareous and fragmental in character. Th~ deposits have a thickness of 150 

feet and contain an extensive fauna of marine animal remains. The formation overlies the St. 

Marys formation unconformably. 

The Lafayette formation in Virginia is similar in character to the same formation ·in Maryland, the strata being found along the western margin of the Coastal Plain in outliers of various 

extent. 

North Carolina.-The Tertiary deposits of North Carolina comprise representatives of the 

Eocene, Miocene, and Pliocene. The extent and character of the deposits have not been known 

until within recent years. Among those who have studied the region may be mentioned Dall, 2128 
748 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Clark,140 Miller,596 and Gardner. To Miller we are indebted for tho detailed stratigraphy and 

to Gardner for an exact knowledge of the molluscan faunas. 

The scheme of classification adopted for the 1~ orth Carolina Tertiary deposits is as follows: 

Pliocene(?) ................ _ .. .' .. Lafayette formation. 

Pliocene ...... __ ._ ....... _._ ... Waccamaw formation. 

Miocene .................. _ ... _ .Chesapeake group: 

Yorktown formation north of Hatteras axis: Duplin formation 

south of Hatteras axis. 

St. Marys sand (north of Hatteras axis). 

E {

Castle Hayne limestone} II · ocene .................... -.-. _ 1 

south of at teras ax1s. 

Trent mar .......... . 

The Trent, which overlies tho Cretaceous deposits unconformably, consists of calcareous 

marls and clays, the former locally indurated, forming a compact limestone. The deposits 

have a thickness of about 50 feet. The fauna consists chiefly of marine invertebrates. The 

formation covers a small area in the valley of Trent River. 

Tho Castle Hayne consists chiefly of calcareous marls and sandy clays. It has a thickness 

of about ~0 feet and contains a fauna of late Eocene age. It apparently overlies the Trent 

unconformably. 

The St. Marys andY orktown formations inN orth Carolina are in general similar in character 

to the same deposits in Virginia. They are both confined to the area north of the Hatteras 

aXlS. 

The Duplin formation consists of sands, clays, and marls and represents the Yorktown 

formation south of the Hatteras axis. It has a thickness of 100 feet and contains an extensive 

marine fauna similar to the Yorktown but of a warmer-water facies. 

The Waccamaw formation consists of sands, clays, and marls. It is confined to a narrow 

belt along the eastern margin of the State where it rests unconformably on older formations. 

It has a thickness of about 50 feet. Its fauna is marine in character and consists of characteristic 

Pliocene forms. 

The Lafayette formation consists of sands, loams, and gravels and is confined chiefly to 

outliers west of the main body of Coastal Plain sediments, where it forms the series of "sand 

hills." 

General remarks.-The Tertiary deposits of this region overlie the Cretaceous strata unconformably, but owing to the differential movements already described the later transgress the 

earlier formations in certain areas, so that the Cretaceous deposits arc in some localities overlain 

by Eocene and in others by Miocene or later formations. The dip of the Eocene formations 

rarely exceeds 15 feet in the mile toward the east and is in many places less; the dip of the 

Miocene formations is 10 to 12 feet in the mile, and that of the Pliocene formations is even less. 

The correlation of the Tertiary formations within the region and with other areas is shown 

in the following tables. 

Eocene formations in northern part of Atlantic Coastal Plain. 

--------------- 1\ ew Jersey_ Maryland and Virginia. "Norlh Carolina. Alabama. 

Castle Hayne. 

Jackson and Claiborne. ---------- -------- -------------------------------

Trent. 

Nanjemoy. 

Wilcox. --------------------- ---------------- - --- ------------

A quia. 

Shark River. Midway. 

-----------~----------~----------------------------
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 749 

Miocene and Pliocene formations in northern part of Atlantic Coastal Plain. 

' ----~ ------------~--------~-----c--------c------~~-----~---

Long Island and south-~ I Maryland and ern New England. Kew Jersey. Delaware. 

----~[ -------~1 -----~ 

Pliocene (?) I : Lafayette. 

~--~-~~---~--------1 

Pliocene. I I 

~-----------r------

1 I 

I i ~----------~--------- St. Marys. 

Miocene. l J--------1------

1 Deposits of Long Island 

and Marthas VineCohansey and Beacon 

Hill. Chop tank. 

yard. ---------1------

Kirkwood. Calvert. 

Virginia. North Carolina. 

---~-

Lafayette. Lafayette. 

I 

Waccamaw. 

Yorktown. Yorktown and Duplin. 

St. Marys. St. Marys. 

(?) 

Calvert. 

The Eocene deposits are found in three distinct and separate regions, so that the relations 

of the strata in these areas to one another can not be satisfactorily determined. 

The Shark River marl of New Jersey apparently overlies the Manasquan formation of 

the Upper Cretaceous conformably. The two formations constitute a continuous series of relatively deep water deposits, no evidence of erosional or other unconformity being found. These 

stratigraphic features, together with a somewhat undiagnostic Eocene fauna, have led to the 

reference of the beds to an earlier horizon than that of the Aquia formation of Maryland, which 

overlies the Cretaceous strata with a marked unconformity. The Shark River marl has been 

referred to the Midway horizon of the Gulf. 

The Aquia and Nanjemoy formations contain a distinctively Wilcox fauna, the Aquia 

being clearly lower Wilcox and the Nanjemoy probably upper Wilcox, although a few Claiborne 

forms appear in the upper beds of the Nanjemoy and it may in part belong to that horizon. 

The Trent and Castle Hayne formations occupy a small area south of the Hatteras axis in 

North Carolina. The faunas have not yet been fully studied, but the forms found are of late 

Eocene age, which would suggest their reference to the Jackson, although they may also represent a part of the Claiborne as well. The bryozoans in the Castle Hayne have led Bassler to 

refer this formation to the Vicksburg. 

The Chesapeake group and equivalent Miocene deposits from the New England coast to the 

Hatteras axis m North Carolina belong to ~ single geologic province, the strata and the fossils 

presenting a marked similarity throughout, though showing indications of increasingly colder 

waters toward the north. The Duplin formation south of the Hatteras axis is a part of the 

southern province and contains a fauna characteristic of much warmer water than that of the 

Yorktown, the synchronous formation to the north. 

The Waccamaw formation is limited to the belt near the coastal border of North and South 

Carolina and contains a subtropical fauna. 

The Lafayette formation has been traced along the western margin of the Coastal Plain, 

oecurring as outliers on the adjacent Piedmont Plateau, from Pennsylvania, where the last 

remnants are found, to North Carolina. Berry80 has shown that the deposits at Lafayette, 

Miss., the locality from which the name is derived, are of Eocene age, so that the term Lafayette 

is really a misnomer. Much question still exists as to whether the Lafayette of the Atlantic 

Coastal Plain is late Pliocene or .early Pleistocene. 
750 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

I-J 11. GREAT BASIN, NEVADA AND CALIFORNIA. 

The Esmeralda formation 814 occurs in southwestern Nevada along the base of 

the Sierra Nevada in the ranges developed by later Tertiary movements. It is 

tentatively assigned to the Oligocene and described as a lake deposit. Its general 

character appears to place it among the continental deposits of' mixed character. 

The southern portion of the Great Basin, lying in southeastern California near the 

K evacla line, comprises Death Valley and the adjoining ranges, which are composed 

largely of Tertiary strata. Spurr 772a says: 

In the eastern part of the [Grapevine] range, where the road crosses from the Amargosa 

Valley into Furnace Creek, there is found a great amount of conglomerate, forming high hills. 

These conglomerates are very coarse and contain rounded pebbles and bowlders of all sizes, 

made up of reddish and white quartzite and black and gray limestones bearing the badly preserved Paleozoic fossils above mentioned. The conglomerate is as hard and firm as the rocks 

from which it is derived. It is water-laid and well stratified and evidently a shore formation. 

The whole thickness exposetl is estimated at 4,000 feet. It is sharply folded, together with 

the limestones from which it is derived, but it abuts abruptly against these limestones on 

the west. 

The irregularity of the contact between conglomerate and limestone denotes a great erosion 

interval, yet no unconformity of attitude is apparent. 

This conglomerate seems to fringe the north edge of the bold Paleozoic scarp of the Grapevine Mountains across the greater portion of the range. It is found at various points. A little 

west of Pyramid Peak conglomerate occurs, interbedded with and running laterally into a hard 

limestone, which has all the appearance of being calcareous tufa. A specimen examined microscopically bears out this idea and shows that the rock is probably a chemical precipitate. It 

is like a rock foun<l in crossing the Panamint Range from Death Valley to Windy Gap, and 

also like one from the Esmeralda formation, between the Candelaria Mountains and the Pilot 

Range. 

Besides these rocks there occur, as parts of the same series, semiconsolidated gravels, with 

clays partially hardenetl to slaty shales, limy clays partially consolidated to argillaceous secondary limestones, and sands partially hardened to cherty and limy sandstones, all interbedded. 

All these, including the conglomerate and the limestone tufa, have a general light-yellow, qften 

greenish color, characteristic of the series. 

This sedimentary series makes up the greater portion of the Funeral Range. Along Furnace Creek valley and on both sides of it the mountains consist chiefly of yellow-green strata 

capped by basalt. The lava seems to occur interbedded with the sedimentarios, as well as 

overlying them. The series is here consolidated into a hard clay rock, with occasional thin 

sandstone, and the general yellow-green color is changed in places to reddish, yellowish, and 

pinkish. The rocks are often gypsiferous and contain abundant grass remains, which are, 

however, indeterminable. From the yellow-green Tertiary series in the hills just east of the 

mouth of Furnace Creek there has been taken much borax, which occurs as borate of lime in 

beds in the strata. * * * 

On the eastern side of Death Valley, southward from Furnace Creek, the upturned yellowgreen Tertiaries, with some few intercalated sheets of lava, constitute the mountains. Beneath 

some of these sheets the clays are baked to a red, natural brick. The lavas seem to occur chiefly 

at the top of the yellow-green series, or at a still higher horizon, for the great mass of beds 

exposed in tlie lower portion of Furnace Creek contains no lava sheets; yet in these beds occur 

occasionally lava bowlders and pebbles, so that we conclude that the period was one of continual volcanic activity. From fragments of lava picked up at the base of the mountains and 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 751 

from observations at a distance the lower lavas seem to be not so basic as the upper ones, which 

are chiefly olivine basalt. A single specimen of biotite andesite was all that was collected to 

represent these more siliceous volcanics. 

Near the summit of the pass, just east of Furnace Creek, there come in above the yellowgreen Tertiary series softer dark-brown honeycombed conglomerates, recalling the similar rocks 

of Meadow Valley Canyon. Thin sheets of basalt are interbedded with the conglomerates, 

but the great sheets lie on top. Patches of this same upper conglomerate series were elsewhere 

observed, and at one place its contact with the underlying yellow-green series appeared slightly 

discordant. The conglomerate contains pebbles and bowlders which are chiefly of lava and 

must have been derived from the sheets of basalt which were periodically poured out during 

the deposition of the beds. 

A rough estimate of the thickness of this whole series of slightly consolidated beds and 

volcanics puts it at not less than 4,000 feet and the nature of the sediments shows that they 

must have been deposited in standing water. The presence on some of the beds of gypsum, 

borax, and calcareous tufa shows that at some periods the waters in which the sediments were 

deposited were evaporated. They were, therefore, those of an inclosed lake, which was probably of great dimensions. It is likely that a large portion of the beds were deposited in fresh 

water at a period different from that in which the chemical precipitates were laid down. 

The borax in these beds is probably contemporaneous with the borax deposits in similar 

folded Tertiaries at Daggett and elsewhere in the Mohave Desert. Between these two localities, moreover, the strata, so far as known, appear to be roughly continuous. The strata of 

Mohave Desert are exposed on a grand scale at Cajon Pass, where they contain beds of black 

lignite. 

Northward from Furnace Creek, at Silver Peak, are found beds of the Esmeralda formation, which are entirely similar in nearly every respect to those at Furnace Creek. Moreover, 

the fossils found in the Esmeralda beds indicate a nearly similar age to that indicated by 

fossils found in the Tertiary strata of the Mohave Desert, just west of Cajon Pass. 

The upper part of the Furnace Creek beds is identical in appearance with certain semiindurated and slightly folded conglomerates and sandstones found in Meadow Valley Canyon, 

which have been referred to the Pliocene. 

J 10. SACRAMENTO VALLEY AND COAST RANGES, CALIFORNIA. 

The general relations of the Eocene of the Pacific coast to the underlying 

strata are thus stated by Arnold :

31 

A widespread unconformity exists between the Eocene and the Cretaceous on the Pacific 

coast of North America. Throughout Washington, Oregon, and certain parts of California 

this unconformity is angular, while over considerable areas in California and at one locality 

in Oregon the unconformity may only be recognized by a more or less marked hiatus in the 

faunas. 

It is a noteworthy fact that wherever the line between the marine Eocene formations 

(1Iartinez, Arago, Tejon, etc.) and the Cretaceous beds is marked by an angular unconformity, 

the underlying beds are either of lower Cretaceous (Knoxville) or middle Cretaceous (Horsetown) age, and that wherever the Eocene rests on the Chico, or upper Cretaceous, with the 

one exception at San Diego, the unconformity is not angular and, as far as the stratigraphic 

evidence goes, the two formations represent an apparent uninterrupted period of sedimentation. 

The apparent conformability of the Eocene on the Cretaceous, together with the superficial similarity of their faunas, led Gabb and Whitney, of the early California Survey, to class 

the Martinez and Tejon formations with the Cretaceous. "White, Stanton, and Merriam have, 
752 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

however, shown the Eocene age of the Martinez and Tejon. Of the relationships existing 

between these two and the Chico, or upper Cretaceous, Dr. Merriam has the following to say:a 

"The Martinez group, comprising in the typical locality between 1,000 and 2,000 feet of 

sandstones, shales, and glauconitic sands, forms the lower part of a presumably conformable 

series, the upper portion of which is formed by the Tejon. It contains a known fauna of over 

sixty species, of which the greater portion is peculiar to itself. A number of its species range 

up into the Tejon and a very few long-lived forms are known to occur also in the Chico. Since 

the Martinez and Chico are faunally only distantly related it is probable that an unconformity 

exists between them." 

Another fact showing the relations existing between the Eocene and the Cretaceous is 

the occurrence in the Eocene beds in the Roseburg region, Oregon, of oysters so similar in 

appearance to the characteristic Cretaceous fossil, Gryphrea, that without their accompanying 

Eocene fauna these oysters would certainly be mistaken for Cretaceous forms. 

* * * * * * * * * 

Rocks of marine origin and Eocene age are found at many localities throughout Washington an<d Oregon west of the Cascade Range and over considerable areas of the Coast Ranges 

in central and southern California. Although Eocene rocks probably once fringed the greater 

part of the western base of the Sierra Nevada, they are now all removed by erosion or covered 

by later formations except at one locality near Merced Falls. For the most part the Eocene 

rocks of the Pacific coast are either sandstone or shale. Conglomerate is found at the base 

of the formation throughout southeastern Oregon, north of San Diego, and at a few localities 

along the northeastern flanks of the Coast Range; and at Port Crescent, Wash., Eocene fossils 

are associated with tuff, but these occurrences are exceptional. Also, diatomaceous shales 

occur at the top of the Eocene series in the vicinity 9f Coalinga, Cal., where they are believed 

to be the source of important deposits of petroleum. Coal and other indications of shallow 

and brackish water conditions are found over much of Washington and Oregon and California, 

usually overlying marine Eocene beds. The maximum thickness of the Eocene sediments 

varies from 8,500 feet east of the Cascades, b 10,000 to 12,000 feet in western Oregon, c to 9,000 ± 

feet in southern California. d 

The Tejon is the prevailing marine Eocene formation of California. Notes on 

its general relations and the extent of its occurrence have already been quoted 

from Arnold. Stanton 777 discussed the stratigraphic and faunal relations with 

the Chico and concluded that the Tejon and Chico are distinct. Gabb 3s

1 had 

described the Tejon as Cretaceous, whereas Cooper 170 and White 889 had regarded 

it as a transition from Cretaceous to Eocene. 

Arnold 33 has recently published the following classification and description of 

the rocks in the Santa Maria district: 

a Jour. Geology, vol. 5, 1897, p. 775. 

b Smith, G. 0., Mount Stuart folio. 

c Diller, J. S., Roseburg, Coos Bay, and Port Orford folios. 

4 Arnold, Ralph, Bull. U.S. Geol. Survey No. 321, p. 21. 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 753 

Tentative correlation of formations of Santa Maria district with the standard California Coast 

Range section and with that of the Santa Clara Valley. 

Era. 

I 

<:) 

·::: 

"' 0 

~ C) 

u 

--

System. Period. 

---

Standard Coast Range I Santa Maria district Santa Clara Valley 

sertion. section. section. 

-------1---------~i---------·-- ------·---~--

~ Recent. 

<ll 

"'"' ~ Pleistocene. ;::l 

I Alluvium. Alluvium. Alluvium. 

l------1 Terrace deposits and dune Sand and gravel. 

01 

Pliocene. 

I 

I 

I 

San Pedro. sand. 

--Unconformity----Unconformity--

----1--------~-- Unconformity --1 

Merced. I 

Purisirna. I Fernando. Fernando. 

>. 

... 

. ~ 

"'"' ... 

<ll 

E-< 

San Pablo. I 

! --Unconformity -~~ -- Unconformity----Unconformity--

~riocene. Monterey. Monterey. !

Shale. 

M d 1 Upper sandstone. 0 e 0 Shale. 

Lower sandstone . 

Vaqueros. Vaqueros. 

-------1-----------1 Vaqueros, Sespe, and 1---------~ 

I 

Tejon, undifferentiated 

San Lorenzo. (including some Monterey in Santa Y nez ------ --L'"nconformitv?-- Range). I I • 

j Oligocene. 

I 

I Tejon. 

{

Upper. 

Sespe Red beds. 

Lower. 

-----------

Topatopa. Eocene. ~-------

1 i 1\Iartin,ez. . --~--1---- ----·---·--Dnconformlty?---

Chico. 

--Unconformity--

Horse town. --Unconformity-~ 

Knoxville. ---------~~-~~--Unconformity---

ob ~ [ Franciscan. . ~ ~ --UnconformitY--

,.=; ·~ Granite, schist, etc". 

(?) 

Knoxville. 

Franciscan. 

(?) 

--~'C nconformity---

Granite, gneiss, etc. 

The Sarita Ynez Range is mostly composed of a thick terrane of marine sediments equivalent to a part or all of the Tejon formation and the Vaqueros formation. The former is Eocene 

and the latter lower Miocene in age. This terrane comprises a continuous succession of marine 

sediments of detrital origin, seeming to present no point at which an angular unconformity 

exists, although the line at the base of the coarse conglomerate containing the Vaqueros fossils 

doubtless marks a long time interval. 

* * * * * * * * * 

The lower portion of the terrane is made up of a thick series of greenish-gray coarse and 

fine sandstones, many of them concretionary in character, interbedded with dark, fine-grained 

thin-bedded shales in lesser amount. Toward the middle of the terrane the shale increases 

in amount, alternating with thin beds of sandstone. Much of the shale has a characteristic 

olive-gray color. * * * The shales and sandstones give place above the middle of the 

terrane to deposits of shallow-water character-coarse sandstone and a great quantity of 

coarse, in many places greenish or reddish gravelly conglomerate. This conglomerate contains abundant Vaqueros [Miocene] fossils and probably represents the base of that formation 

48011°--12----48 
754 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

and a period of shallow-water conditions with which the Vaqueros began. The conglomerate 

gives place in turn to more shale and sandstone, which continue to the summit of the terrane. 

At the top there is a conformable gradation into the Monterey (middle Miocene) beds, the 

summit of the Vaqueros being marked by a calcareous zone in many places-as, for instance, 

southwest of Lompoc, where the two formations are divided by a very prominent exposure 

of hard limestone. 

In the hills west of Tulare I,ake lies the Coalinga oil district, studied by Arnold 

and Anderson, 3

4c who tentatively assigned to the Tejon formation a series of beds 

described as follows: 

The formation mapped as the Tejon in the Coalinga district is made up entirely of sedimentary strata that dip toward the great valley in the monocline along the eastern flank of 

the mountains and are exposed on the surface in a narrow ,discontinuous belt between the 

Cretaceous beds which underlie them and those of the Miocene which overlie them. The beds 

so mapped have a thickness of 1,600 to 1,850 feet and are divisible into two main members of 

approximately equal thickness-a lower one consisting of sandstone in the southern part of the 

district and of dark clay shale and sand in the northern part, which is certainly of Eocene age, with 

the possible exception of a small thickness at the base, and an upper one of light-colored organic 

shale which affords few species of fossils and no conclusive evidence as to its age. This upper 

member may represent either Eocene or Oligocene time, but the facts that there seems to be a 

gradation from the beds of the lower member into those of the upper and that the two invariably 

occur together in this region favor its assignment to the Eocene. It is made up of thin beds 

of whitish and purplish siliceous, argillaceous, and locally calcareous shale, which is easily 

recognizable and which lends individuality to the formation. The shale is very similar, especially 

in some places, as north of Coalinga, to the siliceOll.3 shale of the formation along Reef Ridge 

that is described later as the Santa Margarita ( ?) formation, and the two must not be confused: 

It is also somewhat similar to the purple shale of the upper Chico. Where the Tejon formation 

is thick, shale and clay form a greater proportion of the whole than the sandstone, but a great 

local variation in the thickness of this member is noteworthy because due to the great unconformity between it and the overlying Miocene beds. A large portion of the formation had been 

worn away before the Vaqueros (lower Miocene) sandstone was deposited on its upturned 

surface. It is possible that an unconformity occurs within the beds mapped as Tejon at the 

base of the upper shale, but no discrepancy in dip between the beds of the two divisions has 

been found, and the succession of beds is seemingly continuous. 

As already pointed out, an unconformity exists between the Chico (Upper Cretaceous) and 

Tejon (Eocene) beds, in spite of the facts that no sharp line of demarcation is to be drawn 

between the Tejon and the underlying Chico in the northernmost part of the district and that 

there appears to be a gradation from the beds of the former into those of the latter, as if they 

had been formed during a continuous period of sedimentation. In the southern portion of the 

district the Tejon overlies unconformably beds that belong to an earlier portion of the Cretaceous, either lower Chico or Knoxville, thus proving that a period of land conditions and orogenic 

disturbances preceded the Tejon. 

Tejon group was the name applied by J.D. Whitney to the fossiliferous strata in the vicinity 

of Fort Tejon, Kern County, and Martinez, Contra Costa County, which were included by Gabb 

under his division B, or Upper Cretaceous.a As the result of later studies the fossils of this 

formation are now considered to be of Eocene age. Strata of the same age occur extensively 

in the region of Carquinez Straits, east of Mount Diablo, and have been found at a number of 

different points along the western border of the San Joaquin Valley, notably at New Idria and 

in the region discussed in the present paper. 

For a general correlation table of the Tertiary formations of the California 

Coast Range see Chapter XVII (p. 818). 

a Geol. Survey California, Paleontology, vol. 2, 1869, preface, p. xiii. 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 755 

J 12. PLATEAU PROVINCE OF UTAH. 

In southwestern Utah the Cretaceous is overlain by Eocene ('Vasatch) strata. 

Richardson669 a says: 

The Cretaceous rocks are unconformably overlain by Eocene strata, which, as already 

stated, outcrop in the Pink Cliffs and underlie the Markagunt and Paunsagunt plateaus. The 

unconformity, marked by a basal conglomerate containing pebbles of the underlying rocks, is 

emphasized by the absence of the upper members of the Cretaceous system, which are well 

developed in other parts of the plateau province. The Eocene rocks consist of a variable 

succession of shale, limestone, sandstone, and conglomerate that are characteristically varicolored. Shades of red and white predominate and are beautifully developed in the Pink Cliffs. 

Fossils are extremely rare in these rocks and only a few fragments of Vivipara and Unio have 

been obtained in this area, but the characteristic peculiarities of stratigraphy and coloring 

of the rocks leave little room for doubt that, except possibly a few feet of basal beds containing 

conglomerate of doubtful significance, they belong to the Wasatch formation of the Eocene 

series, which is so largely developed in the High Plateaus of Utah and from which characteristic 

fossils have been obtained in a number of places. 

J 12-13. SAN JUAN BASIN, COLO.RADO AND NEW MEXICO. 

The Tertiary of the San Juan Basin of New Mexico and Colorado comprises 

possibly the Animas formation and certainly the Puerco and Torrejon formations 

(Eocene). The Animas formation is thus described by Cross: 186a 

In the article already cited on the post-Laramie deposits of Colorado, the writer referred 

to a series of strata occurring on the Animas River below Durango, which had been visited 

by Mr. T. W. Stanton and found to be very similar to the Denver beds. In the summer of 

1894 the writer was able to hurriedly examine this series of beds as exposed on the railroad 

below Durango and found them to resemble the typical Denver beds in a very high degree. 

These strata occur above the Laramie and below the Puerco and, as far as the present meager 

observations show, are conformable with both of them where now preserved. The beds are 

some 700 feet or more in thickness and are composed of yellowish-brown clays, tuffs, sandstones, 

and conglomerates, in which andesitic material greatly predominates, and present a variety 

rivaling that in the Denver beds. 

A few fossil plants occur, but those found thus far are poorly preserved, and the only 

identifiable species collected is Magnolia tenuinervis Lx., a common Denver bed species originally 

described from Table Mountain. No invertebrate fossils have been found as yet, but it seems 

probable that a number of vertebrate species, described by Cope as from the Laramie of the 

Animas River section, came out of the strata which so closely resemble the Denver formation. 

In an article discussing the relations of the Puerco and Laramie deposits Prof. Cope refers 

to the succession of beds on the Animas River, saying: "According to the observations of Mr. 

David Baldwin the Laramie beds succeed [the Puerco] downward, conformably it is thought 

by Mr. Baldwin; and have a thickness of 2,000 feet at Animas City, N.Mex. [Colorado?]. A few 

fossils sent from time to time by Mr. Baldwin identify the Laramie. This is especially done by 

the teeth of the dinosaurian genus Dysganus Cope, which is restricted to the Laramie formation 

elsewhere, also by the presence of the genera Lrelaps and Diclonius, which in like manner do 

not extend upward into the Puerco beds." 

According to the statement of Prof. Cope, made personally to the writer and quoted with 

his permission, these fossils were collected incidentally to the investigation of the Puerco fauna 

and for the purpose of identifying the underlying formation. He believes it most probable 

that they came from what are here called the Animas beds, which extend for several hundred 

feet below the Puerco. Prof. Cope now regards the Dysganus and Diclonius as closely allied 

to the horned dinosaurs (Ceratopsidre Marsh, Agathaumidre Cope), which, as will be shown, 

form the most characteristic element of the vertebrate fauna known in the Arapahoe and 

Denver beds. 
756 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The Animas beds, as this post-Laramie formation may be called, are to be regarded as a 

most direct equivalent of the Denver beds, identical in peculiar lithologic character, lying 

between typical Laramie and Puerco, and containing fossils which, so far as known, indicate 

a similar fauna and flora. 

The Tertiary of the northwestern part of the San Juan Basin is outlined in a 

recent map accompanying a report on the coals of the region, in which M. K. Shaler 727 

thus states the relations of the Tertiary and Cretaceous: 

The Animas beds outcrop only in a narrow belt along the north border of the field, thinning 

rapidly both east and west from Animas River. If present at all in the central part of the 

area, they are hidden by the Puerco marl, which north of Pueblo Alto apparently overlaps the 

Cretaceous rocks. Unconsolidated white sand, unquestionably of Puerco age, here lies in 

contact with an irregular surface of Laramie coal, immediately overlying the basal sandstone 

member of that formation. At this place the outcropping Laramie is only about 200 feet thick. 

The upper and lower limits of the Puerco marl are difficult to determine in the area of flatlying beds near Rio Chaco. There is nearly everywhere a marked gradation between these 

rocks and the Laramie, although the main body of the Puerco is easily distinguished by the 

presence in it of fossil mammal remains and silicified wood. 

The available notes on the stratigraphy of the Puerco and Torrejon have been 

well summarized by James Hervey Smith: 761 

The Puerco formation is located in northwestern New Mexico at the headwaters of Puerco 

River, from which the formation takes its name, and where it "reaches a thickness of outcrop 

of about 850 feet." a The rocks of this formation consist of "sandstones and gray and green 

marls." a The formation is thus characterized by 'Wortman: b "The thickness of the beds is 

roughly estimated at 800 to 1,000 feet, and as far as can be observed they lie conformably upon 

the Laramie." 

The fossils occur at two horizons which are separated by barren strata 700 to 800 feet 

thick (not 30 feet as erroneously quoted by Dall in the Eighteenth Ann. Rept. U. S. Geol. 

Survey, pt. 2, p. 347). "The lower fossil-bearing strata occur in two layers, the lowermost of 

which lies within 10 or 15 feilt of the base of the formation. This is succeeded after an interval 

of about 30 feet by a second stratum in which fossils are found. * * * Both of these strata 

are red clay, and at no place did we find them more than a few feet in thickness." c 

This horizon "is especially and sharply distinguished by the occurrence of the remains of 

Polymastodon, which appear to be entirely absent from the upper horizon." c The upper 

horizon is richer in fossils than the lower. "The genera Chirox and Pantolambda appear to 

belong exclusively to the upper beds." c 

Wortman believes that the upper fossiliferous horizon contains several layers, and that 

their vertical range is somewhat greater than that of the lower horizon. Matthew states that 

the "Upper and Lower Puerco beds do not contain a single species in common, and only three 

or four genera pass through. The two faunas are entirely distinct. Dr. Wortman proposes 

to call the upper beds the Torrejon formation, retaining the name Puerco for the lower beds." d 

Scott correlates the Puerco with the Cernaysien of Europe.e 

Osborn 623a briefly describes the Puerco, 500 feet (Polymastodon zone), as 

bassl Eocene, characterized by small archaic mammals; and the Torrejon, 300 feet 

(Pantolambda zone), as the equivalent of a part of the Fort Union formation of 

Montana, also still characterized by descendants of Mesozoic types. 

a Clark, \V. B., Bull. U.S. Geol. Survey No. 83, 1891, p. 138. 

b Quoted by Osborn, H. F., Bull. Am. Mus. Nat. Hist., vol. 7, 1895, p. 1. 

c Wortman, quoted by Osborn, op. cit., p. 2. 

d Science, new ser., vol. 6, 1897, p. 852. 

e Scott, W. B., Science, new ser., vol. 2, 1895, p. 499. 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 757 

The coal field between Gallina and Raton Spring, N.Mex., in the San Juan coal 

region, is described by Gardner 358a as follows: 

In the vicinity of Gallina and to the south beyond Lajara the variegated shales of the 

Wasatch rest horizontally against the foot of the SierraN acimiento, covering the highly inclined 

strata of the Cretaceous and lower sedimentary rocks. The Wasatch bears many fragment& 

of vertebrates, and collections were sufficient to permit its positive identification. 

In the southern portion of the area, along the mountain foot northeast of Cuba and along 

the headwaters of Rio Puerco, the Wasatch is underlain by a mass of variegated bituminous 

shale, with two beds of massive sandstone. The sandstones form prominent escarpments, 

the upper immediately west and the lower about 10 miles southwest of Cuba. The entire 

thickness of these beds is about 800 feet. They are highly inclined along the mountains, and 

northeast of Cuba they are overturned and dip toward the mountains at about 70°. The high 

dips of the massive sandstones are in marked contrast to the unconformable horizontal shale 

of the overlying Wasatch. The prominent sandstone escarpments swing westward from Cuba, 

the lower being traced across the area beyond the limits of the present mapping. The upper 

escarpment could not be traced with certainty. The prominent escarpment of the Wasatch 

to the north follows in a general way parallel to these escarpments. Near a small pond, about 

7 miles N. 76° E. of Ensino Spring, vertebrate fossils were collected from 25 feet of dark and 

gray argillaceous sand and shale immediately overlying the basal escarpment sandstone. A 

careful study of these fossils has been made by J. W. Gidley, of the United States National 

Museum, and the specimens have been compared with original material in the American Museum 

of Natural History, New York. This comparison definitely places them in the Torrejon 

formation.a The Laramie reappears from beneath the lower escarpment, striking almost at 

right angles with it, thus bringing out a marked unconformity between the two. It does not 

follow from the fossils that the lower escarpment is of Torrejon age. It is probable that there 

is an unconformity between the Puerco and the Torrejon. This accounts for the Torrejon 

fossils immediately above the basal escarpment sandstone, which is in all probability the lowest member of the Puerco.. It is certainly at the base of an 800-foot mass below the "\Vasatch, 

exposed along the headwaters of Rio Puerco, as originally described by Cope.b Along Rio 

Puerco the base of the Wasatch is 750 feet above the top of the basal Puerco sandstone. At 

the point where the Torrejon fossils were collected the base of the Wasatch, as determined by 

both stratigraphic relationship and fossil evidence, is only 135 feet above the top of the samec 

sandstone. Hence the 800 feet of the original Puerco is represented by only the basal sandstone, 

from 30 to 50 feet thick, unconformably overlying the Laramie. This sandstone is unconformably overlain by 110 feet of Torrejon, above which, also unconformably, lies the ·wasatch. 

J 13. GREAT PLAINS OF COLORADO. 

In the plams southeast of Denver the Oligocene and possibly part of the Eocene 

are represented by the Monument Creek formation. Darton 240 describes it asan extensive deposit of conglomerates, sand, sandstone, gravel, and clay, known as the Monument Creek formation. It lies on the Laramie formation to tho east and tho Arapahoe formation 

to the west, and at Palmer Lake it abuts against the granite at tho foot of the mountain. Ther0 

arc two members, a lower one of sands and clays and an upper one of conglomerate and sandstone. The latter caps numerous buttes and plateaus in the high region west and north of Calhan 

and north of Monument. 

Fossil bones of Titanotherium have been discovered by the writer c and Mr. C. A. Fisher 

in the upper member of the region north of Calhan and southwest of Elizabeth, which indicate 

a Torrejon is a name proposed by J. L. Wortman (Bull. Am. Mus. Nat. Hist., vol. 9, 1897, pp. 260-261) for a fossil 

zone at the top of the original Puerco of Cope. 

"Cope, E. D., Rept. Chief Eng., 187.5, pt. 2, p. 1008. 

c Darton, N. IL, Age of the Monument Creek formation: Am. Jour. Sci., 4th sor., vol. 20, 1905, pp. 178-180. 
758 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

that this portion of the formation is of Oligocene age. The lower member may be Oligocene, or 

perhaps Wasatch or Bridger, in age. 

In southern Colorado just east of the mountains is the Huerfano basin, described 

by Hills 448• 

449 and studied by Osborn. 622 The latter summarizes Hills's conclusions 

and his own: 

In this third paper (1891) Prof. Hills positively identified the "upper beds" as equivalent 

to the Bridger group, and restricted the term Huerfano to these beds, applying the terms 

Cuchara to the middle division and Poison Canyon to the lower division. These divisions, 

correlated with the measurements previously assigned them, would then occur as follows: 

{

Huerfano beds ........ Bridger group ............... , ........... 3,300 

Huerfanoseries(Eocene) .. Cuchara beds .......... }Lower Eocene (Green River, Wasatch { 300 

Poison Canyon beds... and Puerco) ........................... 3,500 

While these studies were in progress a large collection of fragmentary bones was made by 

Mr. Milligan, of Gardner, which is now preserved in the museum of the Colorado Scientific 

Society and which Prof. Hills kindly enabled the writer to carefully examine. 

The essential features of Prof. Hills's conclusions may be summarized as follows: 

1. The identification of the total Huerfano series of 3,300 feet with the Bridger or middle 

Eocene, and the provisional identification of the Cuchara and Poison Canyon series with the 

lower Eocene, in the absence of fossils, upon stratigraphical evidence. 

2. The post-Laramie formation of a great anticlinal axis, as the eastern border of the 

Huerfano Lake to the east and southeast of the Wet Mountain Range and Spanish Peaks, and 

the subsequent removal of this axis by erosion. 

3. The eruption of the laccolithic Silver Mountain and Spanish Peaks subsequent to the 

deposition of upper lake deposits of Bridger age. 

4. The drainage of the Huerfano Lake to the north through the Wet Mountain Valley. 

It should be stated here that these opinions were expressed at a time when several geologists 

had identified Laramie deposits east of the Rockies as Tertiary, owing partly to Prof. Marsh's 

identification of a Laramie dinosaur with Bison alticornis. 

For the sake of clearness of contrast it may be well to summarize at this point the geological 

conclusions formed by the writer and Dr. Wortman during their brief reconnaissance of this 

region: 

1. That west of the Huerfano Canyon the variegated marls, clays, soft shales, and sands 

aggregate only 800 to 1,000 feet in thickness, and are nearly horizontal in position. They 

may be positively divided into Upper beds, equivalent to the Bridger, and Lower beds, equivalent 

to the Wind River, or Upper Wasatch. These constitute the only true Huerfano Lake deposits. 

2. That the Cuchara and Poison Canyon beds are unconformable with the Huerfano beds 

and older than the Eocene, probably marine Cretaceous, as partly determined by the presence 

of a species of Baculites in the yellow sandstone of the typical Poison Canyon section. 

3. That the present canyon of the Huerfano River cuts through the base of the main 

anticlinal axis of post-Laramie origin, which formed the eastern boundary of the lake. This 

axis extended to the south so as to include the base of Silver Mountain toward the Cuchara 

divide; but it lies from 3 to 7 miles west of the anticlinal axis described by Prof. Hills. 

4. That the Huerfano Lake deposition did not extend as far to the east or south as the 

Spanish Peaks, and that the variegated beds observed there are of older origin. This would 

materially effect the geological age of the prominent neighboring laccoliths. 

The geological features of these conclusions can hardly be dignified by the term "a theory 

of the Huerfano Lake," for thev were formed during a hasty reconnaissance of this basin, while 

Prof. Hills's theory certainly deserves the deliberate consideration of a prolonged survey. In 

fact, this basin, with its volcanic disturbances and eruptions, presents in compact form a 

fascinating problem in the geology of Tertiary times. 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 759 

Hills 451b describes the Poison Canyon, Cuchara, and Huerfano formations as 

they occur in the Spanish Peaks quadrangle. The two older formations (Poison 

Canyon and Cuchara) are placed doubtfuily in the Eocene, the Poison Canyon being 

regarded as possibly equivalent to the Arapahoe of the Denver basin. Osborn's 

determination (1897) of the Eocene (Bridger and \Vind River) age of the Huerfano 

formation is sustained by later studies of the fauna by Wortman and Matthew.e23e 

J 13. EAST-CENTRAL COLORADO. 

The Fl.orissant lake beds, discovered by Hayden and described by Peale and 

Scudder, 719 occupy an area too small to be shown on the map, about latitude 39°, 

longitude 105° 20', in the pre-Cambrian mass of the Colorado Front Range. The 

beds consist of volcanic ash, from showers and washed volcanic detritus, more 

than 50 feet thick. The deposit is noted for the rich harvest of fossil insects it 

has yielded. For descriptions of these fossils Scudder 720• 

721• 722• 723 and Cockerell 161• 162 

should be consulted. 

J-K 12-13. UINTA VALLEY, ROAN OR BOOK PLATEAU, AND GRAND :MESA. 

South of the Uinta Range in Utah lies the Uinta Valley, which Emmons 320 

examined cursorily in course of his work for the Fortieth Parallel Survey. The strata 

extend into northwestern Colorado and were there studied by White, 888 who distinguished the Wasatch, Green River, Bridger, and Uinta groups, applying the 

term Uinta to the rocks described by Powell as the Browns Park group. The 

Wasatch, Green River, and Bridger are described as conformable, and the Uinta as 

resting unconformably upon the Bridger and older formations around the east end 

of the Uinta Range. According to the recent work of Gale 355 in this area, the Browns 

Park formation is of later age than the true Uinta of King. It underlies the Bishop 

conglomerate.(Bishop Mountain of Powell), which is the same as the Wyoming conglomerate of the Fortieth Parallel Survey. In Gale's preliminary report 354 the 

Tertiary formations are described as follows: 

[The "Browns Park" formation] consists of loose or slightly consolidated sandy material 

with local harder sandstone beds and some beds of gravel. Contains much calcareous material 

in the form of cement or filling between the quartz sand grains. Its color is everywhere chalky 

or limy white. The thickness is not determined. 

[The Green River formation is] composed of shale, sandstone, and beds of oolitic rock. 

The shaly beds predominate and are very compact and firmly bedded. They are generally 

exposed in escarpments and high bluffs, in which the weathered beds have a very characteristic 

chalky-white aspect. The shales are, however, of various shades of gray, drab, and light brown 

and are in many places hard and thin bedded. In some districts the lower part contains much 

massive white sandstone. Measured sections exceed 2,400 feet; upper limit not reached. 

[The Wasatch formation is] composed chiefly of clay or soft clay shale; commonly variegated, 

but various shades of red and drab predominate. It also contains beds of pebbles or conglomerate of very perfectly rounded siliceous material, such as jasper, colored vein quartz, chert, 

or flint. Sandstones in places very massive and hard. From 4,000 feet in thickness on the 

eastern side of the Uinta Basin to about 2,500 feet near the Utah line. 

[The Fort Union or earlier beds are] not readily distinguished from the Wasatch in the 

Uinta Basin, but are apparently more clearly differentiated in the Yampa field. As developed in the latt~r region they consist of massive white or light-colored sandstones and shales 
760 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

containing valuable coal beds sharply defined at the base by a conglomerate or conglomeratic 

sandstone, without doubt marking an unconformity of considerable magnitude. Thickness 

estimated as about ROO feet on Lay Creek north of Lay. 

Osborn 623g describes the later Eocene deposits of the Uinta Basin as comprising the Uintatherium zone (800 feet), provisionally equivalent to the upper 

part of the Bridger; the Eobasileus zone (350 feet), equivalent to the upper zone 

of the Washakie Basin; and the Diplacodon zone (600 feet), which is the true Uinta 

of King and properly the Uinta formation. This last he regards as "approaching 

if not equivalent to the lowermost ·white River Oligocene-that is, lower Titanotherium zone or Chadron formation." 

Eocene strata extend southward from the Uinta Valley and White River in 

Utah and Colorado and, rising, form the Roan or Book Plateau. Their southern 

margin has been traced by Taff and Richardson in connection with surveys of the 

underlying (Cretaceous) coal measures. Lee 530a states the section as follows: 

The Grand Mesa coal field is located on the southern rim of the Uinta coal basin, which lies 

partly in northwc.;;tern Colorado and partly in Utah. It derives its name from Grand Mesa, a 

high table-land between Grand and Gunnison rivers. The coal beds underlie the mesa and 

outcrop along the south and west sides. They extend westward into the Book Cliffs field, 

north of Grand Junction, a and eastward into the Anthracite-Crested Butte region,b long known 

for its anthracite coal, and thence northward along the Grand Hogback, recently described 

by Gale." 

Generalized section of rocks in the Grand "Mesa coal field, Colorado. 

[Only the Tertiary part of the section is here given.] 

Formation. 

Green River. 

Thickness 

(feet). Characteristics. 

200-1,800 \Vhite friable sandstone and day shale, capped by basalt. 

------------------- ----- --

Ruby (probably Wasatch). 500-2,000 

Conglomeratic sandstone and shale, varicolored. In the eastern 

part of the field the rocks are mainly red and conglomeratic beds are numerous. The basal conglomerate consists principally of 

quartz and chert pebbles and the higher ones of various crystalline, metamorphic, and extrusive rocks. In the western part of 

the field lighter colors prevail and the rocks are finer in texture. 

Unconformity-------1------1---------·----------

Ohio Creek. 

Unconformity. 

100 \Vhite friable conglomeratic sandstone, containing pebbles of quartz, 

jasper, and igneous rock. 

Detailed sections of certain districts covered by the coal surveys made by 

the United States Geological Survey, in 1907-8, will be found under L 12 and L 13, 

pages 774-778. 

--------------- ----- ·--

a Richardson, G. D., The Book Cliffs coal field: Bull. U.S. Geol. Survey No. 316, 1907, pp. 302-320. 

b Eldridge, G. H., Anthracite-Crested Butte folio (No. 9), Geol. Atlas U. S., U. S. Geol. Survey, 1894. 

c Gale, H. S., Coal fields of the Danforth Hills and Grand Hogback in northwestern Colorado: Bull. U. S. Geol. 

Survey No. 316, 1907, pp. 264-301. 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 761 

J-K 13, L 13-14. GREAT PLAINS OF COLORADO, WYOMING, MONTANA, NORTH AND SOUTH 

DAKOTA. 

In the northern and central parts of the Great Plains area there are several 

nonmarine formations lying near the boundary between the Cretaceous and Tertiary, concerning the exact age and correlation of which there has been much controversy. They are the Denver and Arapahoe formations of the Denver Basin 

and the Lance and Fort Union formations of the Dakotas, Wyoming, and Montana. 

The earlier history of the discussion concerning them, in which the more general 

Laramie question is involved, was summed up by Clark 141 in 1891. The Arapahoe 

and Denver formations were first recognized as distinct from the Laramie by Cross 

and Eldridge 322 in the course of their detailed study of the Denver Basin. The 

following statement concerning their age is quoted from Cross: 322a 

Until the discoveries which are described in preceding chapters were made the strata 

of the Arapahoe and Denver formations had been uniformly assigned by geologists to the 

Laramie, under the accepted definition of the latter as the uppermost division of the conformable 

Cretaceous series; and not only had they been assigned to the Laramie, but no characteristics 

of any kind had been mentioned, or apparently observed, by which these upper beds might be 

even locally distinguished from the lower, coal-bearing horizon. This correlation was based 

on the presence of the true Laramie below the beds in question, on the failure to notice their 

peculiar and distinguishing characteristics, and on the assumptions regarding the unity of the 

fossil flora, whose species were, however, collected from widely separated horizons in the Golden 

section. 

In the earliest descriptions of these formations by Mr. Eldridge and the writer they were 

assigned to the Tertiary. The reason for this assignment was the discovery that between the 

I~aramie and Arapahoe epochs there had occurred an orographic disturbance whose magnitude 

was measured, for this locality, by the presence in the Arapahoe strata of pebbles of highly 

indurated clastic rocks, sandstones, conglomerates, etc., clearly belonging to various geological 

horizons as far down as the Trias, representing erosion of 14,000 feet of strata, according to 

the section of the formations in question in the Denver region. The lithological character of 

the Denver beds showed that the interval of unknown duration between the Arapahoe and 

Denver epochs had witnessed the occurrence of volcanic eruptions on a gigantic scale, and also 

subsequent local erosion. 

Up to the time when these formations were thus identified, great orographic movements 

in the Rocky Mountains had been commonly supposed to mark the ending of Mesozoic time, 

and to be in great measure the cause of the wonderful changes that took place at this period, 

especially in vertebrate life, as shown by the remains in the earliest known Eocene deposits. 

The beginning of Tertiary time was also known to be widely characterized by great volcanic 

outbreaks, recorded in the sediments of the Green River, Florissant, and other Eocene basins. 

Hence it seemed natural to place the Arapahoe and Denver beds in the Tertiary, as, perhaps, the 

earliest lake deposits of Cenozoic time. ·Examination of the paleontologic evidence available 

at the time showed either that it did not controvert the assignment or, as in the case of the fossil 

plants, was entirely untrustworthy because the floras of the distinct horizons involved could 

not then be compared. 

The reeent discoveries of fossil vertebrate remains are said by paleontologists to show 

that the life of the epochs under discussion was much more nearly allied to Mesozoic than to 

Cenozoic types, and in deference to this opinion the post-Laramie formations are classed in 

this report with the Cretaceous. But such a course raises !1t once tho question as to the nature 

and position of the boundary between Mesozoic and Cenozoic time in the Rocky Mountains 

and broadens very materially the treatment which must be given to the problem. 
762 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Cross m recently contributed a paper to the discussion of the age of the Laramie 

formation in which he proposed to distinguish those strata which unconformably 

succeed the latest conformable Cretaceous as the Shoshone group. After describing in much detail the various local formations which may be referred to the 

Shoshone group, he says: 192a 

In the preceding discussion I have avoided the question as to the age of the Shoshone 

beds, whether Cretaceous or Eocene. I desire now to urge their reference to the Eocene. The 

Denver beds were originally referred by me to the Eocene, but the great weight attached to 

the Mesozoic affinities of the vertebrate fauna by paleontologists led to a tentative acquiescence 

in the assignment of the Arapahoe and Denver formations to the Cretaceous, in the Denver 

monograph. In that volume I reviewed various aspects of the question and can add but little 

to what was there said. The main point seems to be that the Laramie and Shoshone beds 

belong to a transition series between the Cretaceous and Eocene and that whatever break 

occurs between any two formations is possibly bridged over by deposits of some other locality. 

The Laramie is related to the Judith River and other brackish-water formations of the Montana 

Cretaceous, the Shoshone to the great succession of Tertiary local deposits. The retreat of 

marine waters and the decided uplift of a large continental area marked the appropriate boundary 

· between Cretaceous and Eocene from the stratigraphic side. 

The name Lance formation has recently been adopted by the United States 

Geological Survey for the dinosaur-bearing strata variously known as the" Ceratops 

beds," "Lance Creek beds," "Hell Creek beds," .and "Somber beds," which have 

by some geologists been assigned to the Cretaceous and referred to or correlated 

with the Laramie and by others included in the Fort Union and assigned to the 

Eocene. The typi9al area is in Converse County, Wyo., where the formation has 

yielded an abundant and varied vertebrate fauna, including Triceratops and several 

other genera of dinosaurs and a number of small primitive mammals. Recent 

areal work in connection with the examination of coal lands by the United States 

Geological Survey has shown that the Lance formation is widely distributed in 

Wyoming, Montana, North Dakota, and South Dakota. It is mapped together 

with the Denver, Arapahoe, etc., as "Earliest Tertiary or latest Cretaceous" (5a). 

The Fort Union formation was named by Meek and Hayden/86a who stated that 

it consists of "beds of clay and sand, with round ferruginous concretions, and 

numerous beds, seams, and local deposits of lignite" and "occupies the whole 

country around Fort Union [at the mouth of Yellowstone River], extending north 

into the British possessions to unknown distances; also southward to Fort Clark." 

The formation as developed in this original area is now generally regarded as 

Eocene, and it is so mapped with the other formations of the "Continental Eocene" 

(5bl), but the underlying strata which Knowlton (see pp. 763-764) called the lower 

member of the Fort Union are excluded from it and assigned to the Lance formation. 

The argument for placing the Lance formation in the Cretaceous has been 

presented by Stanton/83 who does not share with Cross the view that there is a 

widespread unconformity of great significance between the Laramie and the Shoshone, although he, like all other geologists, clearly recognizes that there are very 

pronounced local unconformities. Stanton's argument is based on the actual 

stratigraphic sequences and upon the relations of the vertebrate and invertebrate 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 763 

faunas. He does not consider that the floras furnish 5ufficient evidence for correlation with the Tertiary, and he concludes: 

In the interior region of North America the formations between the uppermost marine 

Cretaceous and the Wasatch together constitute a real transition from the Cretaceous to the 

Tertiary. 

Notwithstanding the fact that there are several local unconformities at various horizons 

and perhaps some of more general distribution, there is no conclusive evidence that any one 

of these represents a very long period of erosion not represented by sediments elsewhere in the 

region. 

The Fort Union formation, properly restricted, is of early Eocene age, the determination 

resting chiefly on its stratigraphic position and its primitive mammalian fauna, which is related 

to the earliest Eocene fauna of Europe. The very modern character of the flora tends to 

confirm this correlation. 

The "Cera tops beds" are of Cretaceous age, as decided by stratigraphic relations, by the 

pronounced Mesozoic character of the vertebrate fauna with absence of all Tertiary types, and 

by the close relations of its invertebrate fauna with the Cretaceous. The relation of the flora 

with Eocene floras is believed to be less important than this faunal and stratigraphic evidence. 

Taken in their whole areal extent they probably include equivalents of the Laramie, Arapahoe, 

and Denver formations of the Denver Basin. 

Knowlton, 508 presenting the evidence from the point of view of the paleobotanist, also discusses the stratigraphy and regarding his conclusion states: 

The present paper deals with the extensive series of fresh-water deposits of the Northwest 

(that is, broadly, the region east of the Rocky Mountains and between Wyoming and the valley 

of the Mackenzie River), comprising what is here considered as the Fort Union formation. It 

is shown that the Fort Union embraces more than has been commonly assigned to it. Conformably below the beds by some geologists considered as the true Fort Union occur darkcolored sandstones, clays, and shales, which have often been incorrectly referred to the Laramie, 

or its equivalent, but which are stratigraphically and paleontologically distinct from the Laramie, and the contention is here made that these beds, which include the "Hell Creek beds" 

and so-called "somber beds" of Montana, the "Cera tops beds" or "Lance Creek beds" of 

Wyoming, and their stratigraphic and paleontologic equivalents elsewhere, are to be regarded 

as constituting the lower member of the Fort Union formation and are Eocene in age. 

Knowlton sosa sums up his argument as follows: 

1. The Fort Union formation is a fresh-water Tertiary formation of wide areal extent, 

mainly east of the Rocky Mountains, ranging from Wyoming and western South Dakota over 

western North Dakota, eastern and central Montana, the central Canadian provinces, and 

reaching the valley of the Mackenzie River. 

2. It is shown that the Fort Union formation may be separated into two members on 

lithologic grounds. The present paper deals only or largely with the stratigraphy and paleontology of the lower member, which includes the "Hell Creek beds" and so-called "somber beds" 

of Montana and the "Ceratops beds" of Wyoming. 

3. The areal distribution of the lower member is traced in Montana, North and South 

Dakota, and Wyoming, and its probable extension in other areas ia indicated. Complete lists 

of the fossil plants are given by localities for each of the areas. 

4. It is shown that the lower member rests, in some cases unconformably, in others in 

apparent conformity, on the Fox Hills or Pierre, and the conclusion is reached that an erosional 

interval is indicated during which the Laramie, if ever present, and other Cretaceous and early 

Tertiary sediments were removed. 
764 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

5. It is shown that the beds under consideration, being above an unconformity, can no 

longer be considered as a part of the "conformable Cretaceous series" and hence are not 

Laramie. 

6. It is shown that the two members of the Fort Union, although usually distinct lithologically, can not be separated structurally, sedimentation having been uninterrupted, except 

locally. 

7. The paleontological elements of the lower member are considered at length, beginning 

with the plants. It is shown that of the 84 species, 61 are common to the upper member and 

only 11 species to the Laramie of Colorado, while 15 species are common to other American 

Eocene and nine species to the Miocene. The Eocene age of the Fort Union is fixed by tying 

its flora to that of various Old World beds of known Eocene position. 

8. The invertebrate evidence is shown to be in substantial accord with that of tho plants, 

there being only four of the 49 species common to the Colorado Laramie. All, with a single 

possible exception, are fresh-water forms. 

9. It is shown that the vertebrates afford no positive evidence of Cretaceous age. That 

the dinosaurs exhibit Cretaceous affinities is not denied, since, being without known descendants, it is possible to compare them only with their progenitors. It has been proved beyond 

question that they survived the profound orogenic movement and attendant physical break at 

the top of the Laramie in the Denver Basin of Colorado, and lived on in Arapahoe and Denver 

time, and it is shown that in the areas considered in this paper they passed over a similar erosional interval and are found in association with the Fort Union flora, which is of Eocene age. 

10. The mammals of the lower Fort Union show very little relationship with Jurassic or 

Cretaceous forms but find their closest affinities with those of tho Puerco and Torrejon, which 

are of acknowledged Eocene age. 

11. The chelonians are shown to be of little value in their bearing on tho age of the lower 

Fort Union, especially when compared with the Judith River forms, which are evidently in 

confusion. 

12. It is held that the line between Cretaceous and Tertiary should be drawn at the top of 

the true Laramie. 

13. The final conclusion is reached that the beds here considered ("Hell Creek beds," 

"somber bods," "Ceratops beds," "Laramie" of many w1iters) are stratigraphically, structurally, and paleontologically inseparable from the Fort Union, and are Eocene in age. 

See also A. C. Veatch 840 and Whitman Cross/90 and later papers by Stanton, 784 

Knowlton, 510 and Leonard. 533 

K 10. ROGUE RIVER VALLEY, OREGON. 

Diller 281 says: 

Coal occurs at numerous localities in the Rogue River valley of southwestern Oregon, 

between the Cascade Mountains on tho east and the Klamath Mountains, locally called the 

Siskiyou Mountains, on the west. 

* * * * * * * * * 

The Cascade Range, east of the coal belt, is made up mainly of Tertiary lavas; the Klamath Mountains, on the west, are composed of granular igneous rocks and a smaller proportion 

of nrc-Cretaceous sediments. 

~ The soft rocks in which the Rogue River valley has been cut are sandstones, shales, and 

conglomerates. They dip generally eastward, extending beneath the lava fields of tho Cascade 

Range. The older sediments along the western border of the valley, by Bear Creek from the 

Toll House to Ashland, Phoenix, and Jacksonville, are Cretaceous in age and do not contain 

coal. The coal-bearing rocks lie east of Bear Crock as far north as Medford, but beyond that 

point they overlap the Cretaceous rocks and occupy the whole northern portion of tho Rogue 

River valley. 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 765 

K 12. NORTHEASTERN UTAH AND SOUTHWESTERN WYOMING. 

The southwest corner of Wyoming and the immediately adjacent part of 

Utah were mapped by Veatch,839a who subdivided the Tertiary (all Eocene) as 

follows: 

Eocene: 

Bridger formation. c ••••........................................ : ••••••••••••••• 

Feet. 

1,200-1,800 

Green River formation ........................................................ . 2,000± 

Wasatch group: 

Knight formation .......................................................... . 500-1,500± 

Unconformity. 

Fowkes formation ......................................................... . 0-2,500+ 

2,100-2,200 

0-1,600+ 

Almy formation ........................................................... . 

Evanston formation ("Upper Laramie") ..................................... . 

Unconformity. 

Cretaceous. 

Veatch's table, from the Jurassic to the Tertiary, inclusive, and his comments 

regarding the division line between the Cretaceous and the Tertiary are quoted in 

Chapter XV (pp. 676-677). For detailed descriptions of the formations see the 

work cited. 

The sequence of Wasatch strata thus described by Veatch is correlated by 

Osborn with the Wasatch near Black Buttes in the Washakie Basin; with the 

Wasatch of the San Juan Basin, New Mexico (1,500 feet); with the Wasatch of 

the Bighorn Basin, Wyoming (2,391 feet, Loomis); and with the lower portion of 

the Huerfano formation of Colorado. 

The Bridger and Washakie basins lie in southern Wyoming on either side of 

the Rock Springs dome. The Eocene on the western margin of the Bridger Basin 

has been studied stratigraphically by Veatch, 839 f and the lower Eocene on the flanks 

of the Rock Springs dome by Schultz.716a Schultz defines the area and gives the 

following section of Tertiary rocks: 

The field here considered lies along the eastern margin of the great Green River Basin and 

includes in part, on the east, the Great Divide Basin. It lies on the north flank of the Rock 

Springs dome, which is completely surrounded by Tertiary beds. 

* * * * * * * * * 

Section of Tertiary rocks of Sweetwater County, Wyo. 

Economic designa- Thickness 

tion. (feet). Formation. Description. 

--------1--------1------1------ ----------------

Green River. 

UnconformityGreen River. 

Unconformity -' 

\Yasatch.a 

Unconformity. 

Black Rock coal 

group. 

- ___ _. ------

350 

600 

400-825 

1,200-2,650 ± 

Massive irregular-bedded sandstone. 

Thin-bedded shales, sandstones, and limestones, some of 

which are oolitic, for the most part light colored, white, 

gray, yellow, or greenish. 

Variegated clays, shales, and sandstones, the sandstones in 

places being slightly conglomeratic. 

-------------------------

Alternating layers of white, yellow, and brown sandstones, 

gray, drab, and carbonaceous shales, with coal beds and 

conglomerate containing granite and quartzite pebbles. 

Numerous bands of white concretionary sandstone weathering in irregular shapes. Basal sandstone is conglomeratic. 

a Abundant collections of plants have been obtained from the lower third of this formation and determined by F. H. 

Knowlton, who studied the collections, as undoubtedly Fort Union. 
766 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Osborn 623r gives a columnar section of the Bridger formation, 1,875 feet, as 

developed in the Bridger Basin, based on detailed stratigraphic and paleontologic 

work by Matthews and Granger. Five divisions are distinguished according to 

faunas. The Bridger is assigned to middle Eocene time and correlated with the 

upper part of the Huerfano formation, the lower part of the later Eocene (Uintatherium zone) of the Washakie Basin, Wyoming, and the lower part, or Uintatherium 

zone, of the later Eocene ·of the Uinta Basin of northern Utah; also with the Clarno 

formation of the John Day Basin, Oregon. 

K 12. WIND RIVER BASIN, WYOMING. 

E. G. Woodruff has contributed the following data on the Tertiary of the Wind 

River Basin: 

The highest Tertiary beds recognized in the Wind River Basin are called by Osborn and 

others the Wind River formation (Eocene). They consist of alternate beds of gray, drab, and 

pink very sandy shale and a few sandstone members near the base. In several areas about the 

edge of the basin a conglomerate member is the base of the formation. The Wind River is 

notably unconformable above the Fort Union formation, and probably was deposited subsequently to the formation of the Wind River Basin. The material composing it is believed to 

have been derived from the surrounding mountains. The thickness of the formation is undetermined. The Fort Union formation (Eocene) peeps out from beneath the Wind River cover 

in a few places around the edge of the Wind River Basin. It is believed that all of the Fort 

Union is not -represented in any of these exposures. The formation where seen consists of a 

series of sandy shales and both shaly and massive sandstones which are generally pale rusty 

colored but are locally gray. The underlying formation is the Mesaverde (Upper Cretaceous). 

Osborn/23ct who bases a section of the Wind River formation on work done by 

Hayden and Loomis, assigns 1,200 to 1,400 feet to the formation, with red beds at 

the base. The strata comprise the Lambdotherium and Bathyopsis zones (lower 

to middle Eocene) and fall into two divisions which correspond to the upper part of 

the Wasatch of the Bighorn Basin and the lower part of the Huerfano formation 

of Colorado. (See J 13, pp. 758-759.) 

K 13. WYOMING AND COLORADO. 

The eastern border of the Washakie Basin has been mapped by Ball/3 who 

determined the following section of the Tertiary on the southern line of Wyoming: 

The coal field drained by Little Snake River extends from the Sierra Madre westward to 

and partly into the Red Desert, and from the summit of the Elkhead Mountains of Colorado 

northward to the divide between the Pacific and Great Divide Basin drainages, a few miles 

south of the Union Pacific Railroad. 

The area discussed in this paper is located near the middle of the southern boundary of 

Wyoming. 

The stratigraphic relations of the coal-bearing and associated formations, with tneir general 

character and approximate thicknesses, are shown in the following table [only the Tertiary part 

of the table is quoted]: 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 767 

Gen'!ralized section of coal-bearing rocks in western portion of the Little Snake River coal field, 

Wyoming. 

I Thickness (feet). 

Sys- Formation. Economic desig- Description. tem. nation. North South 

end of end of 

I 

field. field. 

--

Upper part of VIa· Variegated clay passing upward into brown I 

satch and later and gray shales, sands, and sandstones. Top not seen. Tertiary. Not coal bearing. 

~~~~~~-~~~~~~~~~-~~ -~-----~~ ~~,...__~~~ 

~ \Vasatch. 

1 

Shale and soft sandstone, with many beds 

-~ of impure coal. +' (?)~-~~-··~· Conglomerate. .... 

Q) i Upper coal group. Gray and brown sandstones and gray and 8,500 0 to 4,000 E-< I drab shales, with many coal beds. 

Vvnite to dark clay shale. No coal. 

(?)a Heavy sandstone with interbedded shale 

and numerous beds of good coal; con- : glomerate at the base. I 

a The three lower members of the upper coal group have the stratigraphic position of the ''Upper Laramie'' of 

A. C. Veatch (Coal fields of east-central Carbon County, Wyo.: Bull. U.S. Geol. Survey No. 316, 1907, pp. 244-260). 

Osborn correlates the upper part of the section in the Washakie Basin as later 

Eocene, Uintatherium and Eobasileus zones. The strata are largely volcanic ash. 

The lower zone (250 feet) is widely distributed. The upper zone (250 feet or more) 

is restricted to Haystack Butte and the surrounding badlands. 

E. E. Smith 752 gives the following section of the Tertiary in southern Wyoming, 

on the eastern margin of the large area mapped as Eocene. (See Chapter XV, 

p. 680, for the Cretaceous section.) 

The Great Divide Basin coal field is situated along and north of the Union Pacific Railroad in south-central Wyoming and embraces portions of the northeast end of Sweetwater 

County, the northwest end of Carbon County, and the southeast corner of Fremont County. 

* * * * * * * * * 

The coal-bearing rocks of the area here described are of Upper Cretaceous and Tertiary 

ages. They consist of the Colorado, Montana, Laramie, undifferentiated Tertiary, and Wasatch 

formations. Of these, only the last four contain workable coal beds. Thin beds of coal occur 

in the basal portion of the Colorado, but at no place within the area treated do they reach minable thickness. The coal-bearing formations show considerable change in character from the 

southern to the northern edge of the field. Those of the Cretaceous system thin rapidly toward 

the north and the outcrops of the beds of the undifferentiated Tertiary become more and more 

narrow, owing to the overlap of Wasatch conglomerate. The accompanying section shows 

the thickness and general characteristics of the coal-bearing formations near the Union Pacific 

Railroad and in the gap between Whisky Peak and the Ferris Mountains. 
768 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Section of the Tertiary rocks of the Great Divide Basin coal field, Wyoming. 

--~~-~ 

Thicknes~ (feet). 

System. Gtoup. Formation. South Korth General characteristics. 

end of end of 

field. field. 

In the southern part of the area it is com- booed of masslve white and yellowish- rown soft sandstones alternating with lay- ers of drab to black carbonaceous shale. 

The sandstone members harden locally and 

weather into forms resembling large concre- tions. The basal portion is also concre- Wasatch. 900± ,SOO± tionary and contains small granite pebbles. 

In the northern part of the field it consists 

entirely of white conglomerate containing 

decomposed granite bowlders up to 6 feet in 

diameter in the upper portiOn, and of 

coarse-grained white sandstone containing 

scattered bowlders of granite and sedimenUnconformitytary rocks in lower portion. ~------

Tertiary. Alternating layers of soft yellowish-brown and 

white sandstones and drab, brown, and 

black shales. The middle portion consists 

of soft shale and sandstone and is not exI posed in this area. MaRsive white sandI ;wlifferent i a ted I stone at the base is conglomeratic and conTertiary." (?) 7,980± (2,000 tains pebbles of Paleozoic rocks. At the I north end of the field only the lower part ! of the formation is exposed. The proportion of shale is much greater than at the south 

end. The tasal portion contains conglomeratic layers with Cretaceous pebbles up to 

8 inches in diameter. 

I 

Alternating layers of soft drab, brown, and 

black shales and thin strata of dark, rusty-

(?) 800± brown resistant sandstone. Sandstone is 

11,800 increasingly conglomeratic toward the top. 

Shales in northern portion erode into badland forms. I Uncnnf<>=it.y- Alternating layers of yellowish-brown and 

white massive sandstones, thin brown sandstone, and drab, brown, and black shales. 

Cretaceous. (?) l,aramie. b 3,900± ,050 Sandstones are very resistant in southern 

bortion. At north end the sandstones in the 

asal part are more resistant than those in 

the upper part, and constitute prominent 

topographic features. 

a The fossil evidence from this group is conflicting and the age of the group can not be decided until further 

paleontologic work is donfl. 

b Marine Cretaceous (upper Montana) species were obtained about 500 feet above the base of this formation in sec. 1, T. 21 N., R. 89 W., and at the base in sec. 26, T. 26 N., R. 90 W. They mayprobablybe found at various places 

in the lower portion, and therefore no definite formation line can be drawn on paleontologic evidence. The base of the 

sandstones has been used in mapping the formation because it is the only line which is marked lithologically. 

Between the Washakie Basin on the west and the Laramie Basin on the east 

lies the Hanna Basin of Carbon County, Wyo., which comprises the "Lower Laramie" and "Upper Laramie" of Veatch. 841 a 

Veatch's generalized section of the Cretaceous and Tertiary strata is quoted 

on page 676. His "Lower Laramie" is now recognized as Laramie and as of Cretaceous age. His ''Upper Laramie" is regarded by Knowlton as equivalent to the 

Lance formation C'Ceratops beds"), which Knowlton believes is of Eocene age 

and equivalent to the lower part of the Fort Union formation, but which Stanton 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 769 

and others believe is of Cretaceous age and older than the Fort Union, representing 

in fact the upper part of the Laramie. 

Tertiary strata occur in the Laramie Basin and in the valleys of the adjacent 

slopes on the east and northeast. They have been mapped by Darton/47 who 

assigns the deposits on Little Medicine Bow Creek, at the north end of the basin, 

to the Chadron formation, the lower formation of the White River group (Oligocene). 

The age of the other occurrences has not been determined. 

The elevated basin of Middle Park, Colorado, contains strata which are correlated by Cross with the Denver formation. They were first described by Marvine, 577 who distinguished a "doleritic breccia" and a "lignitic formation," the latter 

5,500 feet thick. Cross 185 reviewed Marvine's observations in detail in the field 

and reported on the stratigraphy and correlation of the formations. The strata 

are unconformable to the marine Cretaceous, and their correlation with the Denver 

formation is determined on their stratigraphic condition, lithologic similarity, and 

closely related floras. Cross 186 says: 

The "doleritic breccia" of Marvine is a series of dark tuffs, conglomerates, and breccia 

beds, made up of a large series of andesitic fragments, of types identical with those in tl1e Denver formation. These beds are coarser in texture and are more variable than the Denver strata 

but resemble them very much in many details. The sharp line drawn by Marvine between 

the "breccia" and his "Lignitic" series does not appear justifiable. While Marvine does not 

refer to volcanic materials in the upper series, there is in fact a gradation between the lower, 

dark, almost purely. andesitic strata and the lighter-colored beds above, in which granitic 

debris usually predominates, although micaceous and hornblendic andesites are abundant for 

more than 2,000 feet upward in the series, as far as the writer's observations go. 

Plant remains are the only fossils as yet known from the Middle Park strata. These were 

found by the Hayden Survey party in the "Lignitic" series only, but they occur also in the 

dark tuff layers of the lower beds. A number of the species described by Lesquereux as from 

Middle Park are now known to have come from the Eocene lake bed at Florissant, Colo. The 

entire known fossil flora of the Middle Park series has been studied by Mr. Knowlton. * * * 

Twenty-five satisfactory species are known from these strata, and by far the strongest alliance 

is with the flora of the Denver formations. 

Along the Grand River near Hot Sulphur Springs the stratigraphic relations of the Middle 

Park beds are clearly shown. They here rest upon the upturned and eroded section of the 

Mesozoic series, from the Jura to the Fox Hills, and overlap the former to the granite. 

According to Shaw, 735 the following Tertiary formations occur in the Glenrock 

coal field in east-central Wyoming: 

Red and light-gray conglomerate and sandstone. 

White clay, more or less calcareous and commonly sandy (White River formation). 

Fort Union (?)formation (shales, sandstones, and coal). 

K 13-14. GREAT PLAINS OF SOUTH DAKOTA, WYOMING, COLORADO, AND NEBRASKA. 

Eocene strata are lacking in part of the northern Great Plains, the lower Oligocene being the lowest Tertiary. In considerable areas it rests on the eroded marine 

Cretaceous, though there are outlying remnants on later formations, and it constitutes the White River group of Hayden, which includes the Chadron and Brule 

formations of Darton. Darton 238b says: 

Early in the study of Great Plains geology the Tertiary formations were divided into the 

White River group below and the Loup Fork above. This distinction is a clearly recognizable 

48011°--12----49 
770 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

one, although, as now well known, there were confused under the name of Loup Fork a number 

of separate formations ranging in age from Miocene to early Pleistocene. 

The White River group has been studied mainly in the Big Badlands, lying southeast of 

the Black Hills, where three principal subdivisions were defined, the lower one as the Titanotherium beds, the middle as the Oreodon beds, and the upper as a series consisting of the Protoceras sandstone and some overlying clays. This classification is distinctly set forth by Dr. 

Wortman.a In the Oreodon clays there is often a marked sandstone horizon known as the 

Metamynodon beds. 

In mapping the geology of western Nebraska, in 1897, I had need to subdivide the formations 

in the valley of Platte River and Pine Ridge, where I found that the White River group consisted of the usual basal series, the Titanotherium beds, which I designated the Chadron formation, and the usual overlying series of flesh-colored sandy clays, the Oreodon beds, to which 

the name Brule clays was applied. 

* * * * * * * * * 

The Chadron formation [consists mainly of] sandy clays and greenish-gray sandstones, 

mostly of soft texture, in which characteristic Titanotherium remains are of frequent occurrence. 

The upper limit to the formation is placed arbitrarily just below some pink clays lying below a 

thin bed of limestone, which is believed to be at the same horizon as one in the Big Badlands, 

where it immediately overlies the last of the beds of Chadron character. The thickness of the 

formation appears to be about 200 feet at most, but, as it lies on a very uneven surface, the 

amount varies greatly. The sandstones, which occur at various horizons, appear to lie in narrow 

belts, doubtless indicating channels of deposition. The lineal character of some of these channels 

is very distinctly exposed in the western portion of Goshen Hole. 

The Brule clay consists mainly of a hard sandy clay of pale-pink color and massive structure, 

having near the base a thin layer of limestone. Locally some portions are sandy and contain 

beds of sandstone. * * * In the northern face of Scotts Bluff, * * * from the base of 

the overlying Germg beds to the surface of the river, there is a vertical interval of 500 feet 

continuous outcrop. The formation also has a small additional thickness below the level of 

the river. * * * The badlands topography is a characteristic feature of most exposures 

of the Brule clay. * * * The basal portion of the formation generally includes a thin bed 

of limestone, and at various horizons there are occasional irregular lens-shaped masses of sandstone. * * * [The limestone] is a very thin bed of compact cream-colored rock lying on a 

series of pinkish and greenish clays which are regarded as the base of the formation. 

Beds of volcanic ash occur in the Brule clay, some of them of wide extent and apparently 

at constant horizons. One bed conspicuous in many outcrops lies at 60 to 70 feet below the 

top of the formation in the district south and southeast of Gering. It is about 150 feet below 

the top at Scotts Bluff, a position which it holds for some distance to the west. Another higher 

bed often occurs. Fossil bones of various mammals and turtles characteristic of the Oreodon 

fauna of the Oligocene occur in the Brule clay. 

Osborn 623h assigns the Chadron formation to the lower Oligoce:ae and gtves its 

homo taxis and synonymy. The lower part of the Brule Osborn place3 in the middle 

Oligocene and the upper part in the upper Oligocene; the former comprising the 

Oreodon zone and "Metamynodon sandstones," the latter containing the Leptauchenia zone and "Protoceras sandstones." He also gives the homotaxis and 

synonymy of the lower and upper parts of the Brule. 6231 

a Wortman, J. L., On the divisions of the White River or lower Miocene of Dakota: Bull. Am. Mus. Nat. Hist. 

vol. 5, 1893, pp. 95-105. 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 771 

K-L 10. COAST RANGE OF OREGON. 

According to Diller/73 Eocene rocks form the mass of the Coast Range from 

a point near the Columbia to Coquille River. Three groups of strata are distinguished-(1) the oldest, composed in general of igneous sediments closely related to 

lavas of earlier or contemporaneous eruption; (2) shales, containing here and there 

much material of igneous origin; and (3) sandstones, forming the uppermost group. 

Diller describes many local occurrences and cites Dall's determinations of fossils 

from specific places. 

These Eocene terranes constitute the Arago group (named from exposures near 

Cape Arago), which is divided into the "Pulaski'' and Coaledo formations. 275 

The" Pulaski" formation comprises all the Eocene strata below the coal-bearing 

Coaledo formation in the Coos Bay and Port Orford quadrangles. It consists 

chiefly of soft yellowish sandstone interstratified with thin beds of shale but includes 

also small bodies of limestone composed largely of remains of algre and Foraminifera. 

During the " Pulaski" epoch and particularly toward its close there were volcanic 

eruptions which resulted in basalt flows and tuff beds. 

The Coaledo formation consists of sandstoaes and shales with coal beds. The 

strata were deposited chiefly in brackish waters and thus contrast with the marine 

"Pulaski." Sandstones predominate in the !~wer part of the Coaledo, whereas in 

the upper portion light-colored shales are characteristic. 

The Arago group, composed of the "Pulaski" and Coaledo formations, comprises about 10,000 feet of strata. The uppermost portion as measured near Cape 

Arago consists of foraminiferal and other shales (2,200 feet) and sandstones (850 

feet). The sandstones are distinguished by Dall 211 a as the Tunnel Point beds. 

Regarding th<-~ correlation of the Arago group Dall 211b states: 

Thc,;e beds are composed of sandstones and shales and extend northward from Cape Arago 

to Cape Gregory and thence eastward to .Miners Flat, on the south shore of the entrance to 

Coos Bay, Oregon. They have an average dip of 70° NE. and a thickness of over 3,000 feet. 

They contain Oardita planicosta, Ampullina sp., and other middle Eocene forms which suggest 

their correlation with the Claibornian of the Gulf column. They are apparently newer than 

the blackish rocks of the region about the junction of Little River and the North Umpqua, 

which also contain Oardita planicosta but which have also a large proportion of distinct species. 

They appear to be older than the brackish-water deposits which inclose the Coos Bay lignites, 

though the latter have occasional intercalary marine layers which contain species of fossil 

shells apparently identical with members of the Arago fauna. The brackish-water species 

comprise forms belonging to Corbicula, Cyrena, and .Melania or Cerithiopsis, forcibly recalling 

those which occur in the lignite beds of the Puget group, some of which prove to be identical. 

The Umpqua beds above alluded to contain a notable number of "Loxonema" turrita 

Gabb, which is stated by him to be common in the Tejon, and have been referred by Diller a 

to the Tejon group. While this disposition of them may be confirmed by a study of their . 

fauna and is probable, the Arago beds, which were not at first discriminated from those of the 

Umpqua, now appear, from the differences in their fauna, to require separation as a distinct 

series of beds. 

a Bull. Geol. Soc. America, vol. 4, 1893, p. 219. 
772 INDEX TO THE STRATIGRAPHY OF NORT.H AMERICA. 

See Harris a on the correlation of the Tejon. There seems to be a strong probability that 

part of the bods heretofore referred to the Tejon represent the basal Eocene, but at present we 

arc without sufficient evidence to speak positively. 

Diller describes the Arago group in the Coos Bay 275 and Port Orford 277 folios 

and the Umpqua in the Roseburg folio. 274 The following quotation is from the 

Coos Bay folio: 

The rocks of the Eocene period in this region have been called the Arago formation, but in 

this quadrangle they are grouped into two formations-the Pulaski and the Coalodo. These 

formations occupy almost the whole of the Coos Bay region. They are composed generally of 

sandstones and shales, which are especially well exposed near the mouth of Coos Bay and at 

Cape Arago, where they contain Cardita planicosta and numerous other characteristic Eocene 

fossils. Heavy-bedded sandstones prevail in the eastern part of the area, toward the Coast 

Range, whore the Eocene rocks have a wide distribution, and shales become abundantly interstratified with the sandstones in the western part, near the coast. In the eastern part of the 

quadrangle the sandstones are penetrated and separated by dark, heavy intrusions of igneous 

rock, basalt, and tho overlying sandstone near by generally contains much sediment derived 

from it. 

The strata among which the coal beds are found contain at a number of places the fossils 

which characterize the Arago formation, and it is therefore evident that the coal-bearing strata 

are of the same age as that formation and form part of it. 

L 10. JOHN DAY BASIN, OREGON. 

Merriam distinguished as probably Eocene the Clarno formation, a deposit of 

"tuffs, ashes, and lavas," which overlies the Chico (Upper Cretaceous) and is overlain by the John Day formation (Oligocene) at Clarno Ferry, on John Day River, 

Oregon. He says: 590a 

At numerous localities along the western side of the John Day Basin there are exposed, 

either below the lowest' John Day beds or above the Chico Cretaceous, several hundred feet of 

strata which certainly do not belong to either of these horizons. To these beds the name 

Clarno formation has been applied by the writer. 

Typical exposures of the Clarno are to be seen at Clarno's Ferry, on the John Day east of 

Antelope, near the town of Fossil, on Cherry Creek, and near Burnt Ranch. 

The Clarno formation is made up almost entirely of erupted materials. Part of the section 

consists of rhyolite and andesite flows, but the most characteristic portion comprises sedimentary beds grading from ashy shale to coarse tuff. The ash and tuff beds frequently contain 

plant remains in abundance and were evidently, at least in part, deposited in water. The 

strata seem in some places to have accumulated very rapidly. At one locality where large 

specimens of Equisetum have been found in shaly beds, the stems are standing erect and cutting 

across the stratification planes. This could occur only where deposition or shifting of the 

ashy mud was taking place very rapidly. The wide extent of the plant beds, which seem to 

be present at nearly all of the well-known occurrences of the formation, indicates the existence 

of lacustrine conditions, intermittently at least, over this region during the Clarno epoch. 

The thickness of the Clarno formation is not less than 400 feet. It will probably be found 

to exceed that limit. The strata are usually gray to buff but sometimes show brilliant coloration 

in shades of reel, green, and blue. 

The relations of the Clarno to the Cretaceous may be seen just east of the town of Mitchell, 

where a considerable thickness of andesite and tuff is resting upon the Chico. Again, on the 

wagon road between Allen's ranch and Mitchell, the Clarno appears to rest upon the western 

side of tho Knoxville anticline. 

a Science, vol. 22, Aug. 18, 1893, p. 97. 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 773 

Where the Clarno has been found in contact with the John Day there is no apparent angular 

unconformity of the strata. The difference in induration and weathering is, however, very 

noticeable. The sedimentary parts of the Clarno show a much greater degree of induration 

than the John Day beds immediately above and tend at all localities to form steep bluffs ornamented frequently with balanced rocks or grotesque figures. 'l'he soft beds of the Lower 

John Day normally weather into rounded, mud-covered domes or more gently sloping banks. 

On the river above Clarno's Ferry this formation dips about 15° to 25° to the north and 

beneath the Lower John Day. Fine exposures continue along Pine Creek east of the ferry. 

North of the town of Fossil the Clarno is again seen typically developed and dipping under 

the John Day. Along Currant Creek it is well exposed and is close to or in contact with the 

Columbia lava. 

At most of the localities mentioned the Clarno shows a considerable thickness of lava beds 

toward the top. These flows are not, however, the uppermost part of the section. The base 

of the formation is formed hy andesite flows in several places, but it was not determined whether 

the whole Rection is present at these points. 

At most of the Clarno localities where careful collecting has been done, plant remains are 

found to be fairly abundant. Repeated attempts have been made to obtain vertebrate or 

invertebrate fossils also, but, so far as the writer is aware, none have ever been discovered. 

The plants are, perhaps, most common in a bed of tuff and ash, 100 or more feet in thickness, 

belonging to the middle or the lower part of the formation. 

Knowlton 590b reported on the fossil plants as follows: 

In attempting to work out the bearing of the plants above enumerated on the question 

of the age of the beds, it should not be oYerlooked that any conclusions drawn might be quite 

different from what they would be were the whole flora of each of the localities to be considered .• 

For example, Dr. :Merriam's collection from Bridge Creek embraces only 14 previously named 

species, whereas the complete known flora of this locality includes over 40 species. And further, 

it is impossible at the present time, without having worked out the affinities of the Tertiary 

floras of California and elsewhere, to give with any degree of completeness the outside relationships of the flora of the ,John Day region. The following conclusions, however, are not likely 

to be greatly modified by subsequent work. 

The oldest horizon represented by these collections seems to be that near the crossing of 

Cherry Creek. The species, though few in number, seem to have their greatest affinities with 

forms from the lower Tertiary, and it is probable that this horizon should be referred to the 

lower or middle Eocene. There are a few species in common with Bridge Creek, but in general 

its flora has a slightly older facies. 

The Bridge Creek, as already suggested, has an ample flora which is represented by a 

wealth of individuals. A large proportion of its species are endemic, but on considering the 

obvious relations of these, as well as the forms known from other localities, an upper Eocene 

age is indicated. 

Several other of the localities seem to be of the same age as the Bridge Creek beds, namely, 

1! miles east of Clarno's Ferry, 3 miles above Clarno's Ferry, and one-half mile northeast of 

Fossil. Not more than three previously named species are known from either of these localities, 

and not rarely the identification of some of these is more or less doubtful, but as nearly as can 

be made out they should be of the same age as Bridge Creek. · 

It will be noticed that the determination of the plant remains, both as regards the flora as 

a whole and with respect to its subdivisons, agrees with the statement relating to stratigraphic 

succession. The Bridge Creek beds, with the few specimens from the shales 11- miles east of 

Clarno's Ferry, are considered upper Eocene, while those from Cherry Creek are held to be an 

earlier facies. 
774 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

L 10. CASCADE RANGE AND YAKIMA VALLEY, WASHINGTON. 

The Eocene of the upper Yakima Valley comprises sediments and igneous rocks 

which in order from older to younger are the Swauk formation, Naches formation, Kachess rhyolite, Teanaway basalt, gabbro, Roslyn formation, and Manastash 

formation. The following descriptions are condensed or quoted from those of 

George Otis Smith: 756• 758a 

The Swauk formation consists of conglomerate, sandstone, and shale, which vary greatly 

in character from place to place. At the base there is usually a conglomerate or arkose derived 

directly from the older rocks and composed largely or exclusively of their material. Arkose 

sandstones and carbonaceous shale make up the greater part of the formation. The thickness 

is 3,500 to 5,000 feet but varies with inequalities of the underlying surface, which are considerable. 

The shales contain abundant and well-preserved fossil leaves, which are regarded by Knowlton 

as of Eocene age. 

The Roslyn formation occurs in a small basin in the upper Yakima, where its extent and 

structure have been well determined in the development of the coal mine opened upon its principal coal bed. The greater part of the formation consists of massive sandstones, with which 

fine-grained clay shales are interbedded. The thickness is approximately 3,500 feet. The 

included flora is quite distinct from that of the Swauk formation and has Miocene affinities, 

but, though evidently younger than the Swank, it is considered to belong in the Eocene. 

The Manastash formation is the latest Eocene sedimentary deposit known in the Yakima 

Valley. It rests directly upon the pre-Mesozoic schists, with a well-developed basal conglomerate, and consists of about 200 feet of sandstone and shale. But two small areas are known, 

and they might readily be confused with other similar sandstones, which, however, do not have 

'the flora that the Manastash contains. It has been described by Knowlton, who states that 

none of the species occur in the Roslyn or Swauk formations. They are correlated with species 

found in the Florissant beds of Colorado and at Corral Hollow, California. 

The Naches formation is composed of interbedded sandstone and basalt, the sedimentary 

rock predominating in the lower and the volcanic in the upper portion. * * * No occurrences of the Naches formation are known outside of the Snoqualmie quadrangle. 

Since the Naches and Swauk formations are not found in juxtaposition, there is lack of direct 

stratigraphic evidence regarding their relative ages. It is noteworthy, however, that they have 

similar relations to both the older and later rocks, a fact which suggests that they may be 

nearly contemporaneous. The evidence afforded by fossil plants confirms this view. 

L 12. BIGHORN BASIN, WYOMING: 

For the southwest side of the Bighorn Basin Woodruff 947 determined the following section of the Tertiary: 

Section of coal-bearing and associated rocks exposed along Shoshone River near Cody, Wyo. 

System. Formation. 

~---~~---~ 

Thickness 

(feet). 

-------------

Characteristics. 

----~--- ---1----------

Tertiary. 

Wasatch formation. 

--Unconformity-------

Various colored shales interbedded with sandstone and 

conglomerate. 

Gray to drab sandy shale and tan-colored massive sandFort Union formation. 3,100 stone. In the lower part of the formation conglomerates occur at intervals through 1,000 feet of strata. 

---------~--Unconformity(?)------~--------------

Cretaceous. Laramie (?) formation. [Seep. 684 for the Cretaceous section.] 
EARLIER TERTIARY (EOCENE AND GLIGOCENE). 775 

For the east side of the Bighorn Basin \Vashburne 867 gives the following section: 

Stratigraphic column on the east side of the Bighorn Basin!' 1ryoming. 

-~----

System. 

I ! 

Formation. Thickness Characteristics. (feet). i 

! 

:-- ---

\Vasatch formation. 500 Bright-colored clays, with a few thin lenses of sandstone. Contains workable coal in the central I part of the basin. 

~--Unconformity--

I / Fort u mon · f ormatwn. · 1, 000--2,000 Dark-colored shale and massive sandstone. Contains workable coal. I 

~-Unconformity(?)-- I --------•--

[For the Cretaceous sec p. 690.] 

Tertiary (Eocene). 

Cretaceous. 

_i __ ------ --- --

Loomis 546 has discussed the conditions of deposition in the Bighorn Basin 

and has shown that the strata are mainly fluviatile, using the term to cover all kinds 

of flood-plain deposits, in contrast to lacustrine. Osborn 6230 says: 

Geologically the section is 2,391 feet thick, divided into lower, middle, and upper levels, 

all showing flood-plain rather than eolian characteristics, but indicating different rates of deposition and consequent longer or shorter exposure of the deposits to the sun and air. Only the 

middle or red beds are decidedly fossiliferous, and they seem to have been exposed longest to 

the air, leaving the bones of terrestrial animals on the flats; they contain the typical Wasatch, 

Coryphodon and Eohippus fauna. Occasionally truly aquatic animals, such as crocodiles, fishes, 

and turtles, becoming stranded or inclosed in lagoons far from the river, mixed their remains with 

those of the land animals. Loomis's approximate analysis of the natural habitat of the total 

vertebrate fauna is: Aerial, 3 per cent; terrestrial and arboreal, 77 per cent; amphibious, 12 

per cent; aquatic, 10 per cent. 

The section compiled by Osborn 623b from Loomis gives the Lambdotherium 

zone as the highest fossiliferous horizon of the Bighorn Basin, with 730 feet of 

unfossiliferous clays above it. Lambdotherium occurs at the base of the Wind 

River section and thus serves to correlate the two. 

L 12. WESTERN MONTANA. 

The areas in southwestern Montana on the headwaters of the Missouri, which 

are distinguished by the "Later Tertiary" color on the map, include possibly 

Eocene and .certainly Oligocene deposits. Douglass 288 describes the Sage Creek 

beds (Eocene~), White River (Oligocene), and Fort Logan beds (upper Oligocene, 

John Day~). 

The Eocene ( ~) "occurs on Sage Creek about 7 miles northeast of Lima, 

Beaverhead County." The fossils found are considered to represent Heptodon ~' 

Hyrachynus priscus Douglass, and Metamynodon 1. 

The deposits of White River age are shown to be lacustrine, in contrast to those 

of the Great Plains, and "appear in the main to represent the Titanotherium and 

Oreodon beds of South Dakota." 

The Fort Logan beds of Douglass are the lower Deep River beds of Scott. 717 

They occur on Smith River, formerly known as Deep Creek, southwest of the Little 
776 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Belt Mountains. Scott quotes from the first description by Grinnell and Dana 

(1875): 

The Tertiary beds found here consist for the most part of homogeneous cream-colored clays, 

so hard as to be with difficulty cut with a knife. The beds are horizontal. * * * Some . 

bluffs were noticed where the Miocene beds attain a thickness of about 200 feet and these were 

capped by 50 feet of the Pliocene clays, both beds containing characteristic fossils. 

Scott infers an unconformity between the two, there being suggestions of 

erosion in the surface of the lower and "the fossil contents of the two series of 

strata" being "very strikingly different." 

Calkins, in an unpublished manuscript, states that the age relations of the 

Tertiary rocks in the Philipsburg quadrangle are very imperfectly known. 

If the Eocene is represented at all, it is probably by a very thick accumulation of c~mented 

gravels observed at the east end of the Anaconda Range and by some of the andesitic and 

rhyolitic tuffs associated with them. These rocks are considerably tilted but show far less 

deformati.on and metamorphism than the pre-Tertiary rocks of the region. No fossils have yet 

been found in them. 

See also L 12, Chapter XVII (pp. 831-832). 

L 12. BULL MOUNTAIN COAL FIELD, MONTANA. 

According to \Voolsey, 950 the Fort Union formation in the Bull Mountain coal 

field (latitude 45° 30', longitude 108°) is 1,400+ feet thick and consists chiefly of 

gray to buff sandstone, alternating with gray shale. The sandstone, though 

extremely variable, is commonly massive and evenly distributed throughout the 

section. Coal beds occur at intervals of about 100 feet or less and are most numerous 

in the upper part. The base of the formation is strongly marked by contrast with 

a band of olive-green clay shale, which belongs to the next lower formation. 

Richards 665 and Lupton 553 have reuorted later on the central and eastern parts 

of the field respectively. 

L 12. RED LODGE COAL FIELD, MONTANA. 

Woodruff 946 describes the Fort Union formation in the Red Lodge coal field 

as 8,500 feet thick and as consisting of sandstone and shale, with carbonaceous 

shale and coal at several horizons. Workable coal beds are confined to a zone 

above the middle of the section. The formation is therefore divided into: 

Feet. 

Upper barren member .................................................................... 1,975 

Middle productive member........ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 825 

Lower barren member ......................... :. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5, 700 

8,500 

The lowest member is composed mostly of yellowish sandstone and shale. Beginning 

1,650 feet above the bottom of the formation is a group of beds 1,000 feet thick, composed of 

varicolored sandy shale with a few beds of soft yellowish sandstone, numerous beds of carbonaceous shale, and in the upper part a few coal beds, one of which contains 18 to 24 inches of 

coal. Above this group carbonaceous shale and coal beds occur at diminishing intervals as the 

productive member is approachedo * * * 

In the middle productive member * * * the sandstone and shale resemble the sandstone and shale of the lower member and do not seem to indicate any essential difference in 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 777 

conditions of deposition, but the carbonaceous shale and workable coal beds intercalated with 

the other rocks serve to distinguish the member. As indicated above, the coal beds of the 

middle member do not begin abruptly but are presaged in the lower member by thin beds of 

coal. At the upper limit of the middle member, however, there is a sharp transition from the 

productive measures to the barren beds above. * * * 

The upper barren member * * * is composed, like the lower member, of sandstone 

and shale, with a very little carbonaceous material. Shale predominates in the lower portion 

and sandstone in the upper po:r:tion. 

L 13. PLAINS EAST OF THE BIGHORN MOUNTAINS, WYOMING. 

The Tertiary strata of northern Wyoming were described by Darton 239 under 

the names De Smet formation and Kingsbury conglomerate and were assigned to 

the Cretaceous system. Later investigations show that the "De Smet" formation 

and the Kingsbury conglomerate comprise the Fort Union formation (Eocene). 

Details of the coal-bearing section of the strata in the Sheridan coal field are given 

by Taff, 809 and in the Buffalo coal field by Gale and \Vegemann.357 The name 

"DeSmet" has been abandoned by the Survey in favor of Fort Union, and the 

Kingsbury conglomerate is now treated as a member of the Fort Union, as it also 

is of Fort Union age. 

L 13. MILES CITY COAL FIELD, MONTANA. 

The Fort Union formation in the Miles City coal field is described by Collier 

and Smith 167 as follows: 

The rocks consist of comparatively fine material, mainly clay shale and sandstone, including 

lignite and thin beds of impure limestone. They are all fresh-water deposits and contain an 

extensive fossil flora of about 400 species of plants which resemble those of modern times, and 

a fauna including fishes, fresh-water mollusks, and reptiles. 

The total thickness of Fort Union rocks exposed in the Miles City field is about 900 f:et, 

which may be increased by data obtained from drill holes at 1\<files City to a total of 1,400 feet. 

From a comparison of the section at Miles City with that exposed about 70 miles to the northeast 

near Glendive, it is inferred that the base of the Fort Union formation is not very deeply buried, 

and it is probable that some of the drill holes at Miles City have penetrated to underlying 

Cretaceous rocks. 

The Fort Union rocks exposed are rapidly separated into two members by a marked difference in lithologic character. The lower member, about 500 feet thick, consists mainly of 

alternating beds of clay shale and sandstone, having a general dark-gray or somber hue. In 

detail the individuallayers'of this part of the formation, especially the sandstones, show numerous irregularities of deposition. Thin layers of ferruginous limestone occur at short intervals 

throughout the seotion, and concretion-like masses of the same material, more or less lenticular 

in form, are included in the shales and sandstones. The thicker sandstone beds are usually 

characterized by more or less irregular cross-bedding. Coal is found at numerous horizons, 

but the beds are extremely variable in thickness and horizontal extent. 

L 13. SENTINEL BUTTE COAL FmLD, NORTH DAKOTA AND MONTANA. 

The Fort Union formation in the Sentinel Butte field (latitude 47°, longitude 

104°) resembles the beds as developed in the Miles City field. It is described by 

Leonard and Smith 534 as follows: 

The Fort Union formation has a thickness * * * as measured on its outcrop of 900 

feet. If to this be added 820 feet of lignite-bearing rocks, which are probably to be referred to 
778 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

the Fort Union, penetrated by the Medora wPll below tho lowest )ignite outcropping in the field, 

the total thickness is 1, 720 feet. 

Overlying the heavy sandstone which forms the summit of Sentinel Butte and constitutes 

the topmost member of the Fort Union formation, there are about 40 feet of calcareous clay 

and limestone, as shown in the Sentinel Butte section. These beds are merely the remains of a 

formation which doubtless at one time covered a large area in this region. Strata which have 

yielded Oligocene vertebrates and which occupy a similar horizon immediately over the massive 

sandstones at the top of the Fort Union occur in Chalk Butte, 70 miles farther southeast. Other 

similar buttes in northwestern South Dakota and southeastern Montana have likewise been 

referred to the Oligocene. 

On the basis of mammalian remains, Osborn 623 correlates a portion of the Fort 

Union with the Torrejon formation of New Mexico. In the San Juan Basin of 

northwestern New Mexico the Torrejon is conformably underlain by the Puerco, 

which carries a ·basal Eocene fauna. 

L-M 10 .. OLYMPIC PENINSULA AND PUGET SOUND REGION, WASHINGTON. 

Arnold 29b describes Eocene deposits on the north coast of the Olympic Peninsula 

as follows: 

The oldest formation of definitely known age on the Olympic Peninsula is a 1,200-foot 

series of black basalt and greenish basalt tuffs and tuffaceous sands found in the vicinity of 

Port Crescent and hero designated the Crescent formation. It comprises the region immediately 

west of Crescent Bay and a prominent ridge extending eastward from the latter to Freshwater 

Bay. Venericardia planicosta Lamarck, Turritella uvasana Conrad, and other characteristic 

fossils found in the tuff indicate the Eocene age of the series and its general contemporaneity 

with the Tejon of California. 

The basalt occurs in two thick sheets, an upper and a lower, each of which may represent 

several surface flows. Between the two basalt sheets and intimately associated with the top 

of the lower is a series of roughly bedded fossiliferous tuffs. * * * In the region of Crescent 

Bay the lower basalt has an exposed thickness of 200 feet, while the tuffs and upper basalt 

sheet each show approximately the same. The Freshwater Bay section gives basalt and coarse 

massive basalt tuff 600 feet, thin-bedded green tuff 355 feet, and black vesicular basalt 200 feet. 

The base of the Crescent formation is not exposed, so that the subjacent rocks are unknown. 

The overlying sediments consist of coarse conglomerates separated from the basalt by an 

erosion interval. Faults define the contact between the Crescent formation and the Clallam 

formation (Oligocene-Miocene) adjacent. 

These basalts and tuffs are the only rocks of igneous origin found along the whole length 

of the northern shore of the peninsula. Taking into consideration the volcanic activity which 

prevailed during the Eocene in the Cascade Range, only a comparatively short distance away, 

this single and rather limited occurrence of eruptives seems rather remarkable. The paucity 

of igneous rocks, however, may possibly be accounted for, at least along the northern coastal 

border of the Olympics, by the fact that formations younger than the basalt are the only ones 

exposed, and it is possible that some of these newer rocks are underlain by the Eocene basalt 

senes. 

The Puget group comprises many thousand feet of estuarine and marsh deposits, 

which are extensively coal bearing. ·willis 939 says: 

The coal-bearing rocks of the Puget Sound basin have been designated the Puget formation. 

They are prevailingly sandstones of variable composition, texture, and color, thinly interbedded, 

and frequently cross stratified. Their composition varies from that of a typical arkose, consisting 

of slightly washed granitic minerals, to siliceous clay. Beds of conglomerates or concentrated 
EARLIER TERTIARY (EOCEl\E AND OLIGOCENE). 779 

quartz sands have not been observed. Carbonaceous materials arc generally present as fragments of plants, as vegetal ooze in greater or less proportion to tho other constituents, and as 

distinct coal beds. Carbonate of iron is frequently an integral constituent of the rocks. 

In color they are, when fresh, generally bluish gray, shading to brownish black. They 

weather to buff tints, which arc usually dull. The coarser and more massive varieties form beds 

20 to 100 feet thiQk, in which bedding planes are not distinguishable. The finer deposits are 

thinly laminated and carry abundant leaf impressions, which occasionally interlap with one 

another so as to form a mass of leaf fragments. * * * 

In many of the sandstones silvery-white mica has developed as a secondary mineral, but 

they exhibit no other indication of metamorphism. The coals, on the contrary, being chemically 

more sensitive, have undergone metamorphism to a greater or less extent through loss of 

combined water and concentration of fixed carbon. * * * 

The stratigraphic relations of the Puget series are not determinable within the area under 

discussion, since the strata nowhere come in contact with older sedimentary rocks. Sixty 

miles northward, on the Skagit River, is a contact between similar coa1-bearing strata and 

older metamorphic schists, described in an earlier report as possibly a surface of deposition 

or of faulting. Examination of this locality in 1895 led to the discovery of small pebbles of 

the schist forming a basal conglomerate in the sandstone beds next the contact, which was 

therefore a surface of deposition during a transgression by the sea. Fossils found in limestone 

under the schists are stems of crinoids of Carboniferous or Triassic age, whereas the coal-bearing 

sandstones of this locality are assigned by Knowlton to the Eocene on the evidence of numerous 

leaf impressions. 

The age of the Puget formation has been in doubt because of the obscurity of strati-

. graphic relations, the general absence of marine fauna, and the indeterminate character of the 

flora. * * * 

A preliminary examination of the fossil plants enabled Knowlton to report that the lower 

beds of the series are Eocene, whereas the upper beds may be of Miocene age. The floras from 

horizons several thousand feet apart in stratigraphic range are so distinct as to afford means of 

·correlating separate strata of the Pugct formation. * * * 

The measured sections of the Puget group exhibit total thicknesses of 5,800 feet on Green 

River, 5,500 feet on South Prairie Creek, and 5,480 feet in Carbon River Canyon. None of 

these measures is complete. In each instance the lowest stratum is of the Puget group outcropping on an anticline, and the highest is the limit of exposure where the rocks pass under later 

formations. These sections overlap, and there arc also higher beds exposed on South Prairie 

Creek above the limit of the measured sections. These considerations justify the inference that 

.the thickness of the Puget group may probably be 9,000 feet or more. 

C. A. White, 890 who gave the name Puget to the strata described by. Willis, 

·quotes Newberry on the resemblance of the flora to that of the "Laramie" and 

comments on the molluscan faunas of the two as follows: 

The fauna to which one instinctively turns for the purpose of zoological comparison with 

this Puget estuary fauna is that of the Laramie group. Such a comparison is especially 

suggested by the known floral relations of the two groups of strata, their presumable contemporaneity of origin, and the nonmarine character of the molluscan faunas of both. Upon 

making a comparison, however, important zoological differences appear. It is true, there are two 

species of Corbicula in the Puget fauna that are so closely like Laramie forms as to suggest 

specific identity upon casual examination, but the differences between the two faunas are 

strikingly shown by the family and generic characters of the other members of the Puget fauna 

as compared with the Laramie fauna. 

For example, a species of Teredo has been found in tho Puget group, but no member of 

the Teredinidm has yet boon found in the Laramie. Two species of the Puget fauna are referred 

to the Tollinidm, but no member of that family has yet been found in the Laramie. But the 

generic form which gives an especially unique character to the Puget fauna is that of Batissa. 
780 XNDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

This genus has not hitherto been known to occur in North America in either a fossil or living 

condition, nor has it been found nearer to this continent than certain of the Pacific islands. 

Still the hinge characters observable on these Puget estuary specimens leave no room for 

reasonable doubt that they are strictly congeneric with true Batissa. Indeed, a species of that 

genus which is now living upon the Fiji Islands is closely related to this fossil form: 

Knowlton (in manuscript) has described 365 species of plants from the Puget 

group. The lower strata are Eocene and the upper are possibly Miocene. The 

general character and distribution of the flora are stated by Knowlton 507 as follows: 

The flora of the Pugct formation is an exceedingly rich one. Over 100 species have already 

been named and described, and from tho material in hand it seems safe to assume that the 

number will reach 250 [365]. Inasmuch as a very largo proportion, perhaps more than ninetenths, of tho plants arc new to science, it becomes extremely difficult to settle their affinities 

and determine satisfactorily their bearing on tho question of age. It is only by a study of their 

general facies that results along either line can be obtained. 

While. the Puget flora as a whole may be considered relatively uniform, there are wellmarked differences between tho plants found in the lower beds, as represented at Carbonado, 

Wilkeson, and South Prairie Creek, and those found in tho upper beds at the highest point in 

the Carbon River canyon, tho Clay mine on Green River, Snoqualmie Pass, and at Steels 

Crossing near Black River Junction. Certain few genera are found throughout the series, but 

thus far no species has been noted as common throughout. On the other hand, both lower 

and higher bods are characterized by a considerable number of genera. Thus Quercus, Juglans, 

Rhamus, Populus, and Laurus arc found from base to summit. Tho following genera have thus 

far been found in the lower beds but not at all in the upper: Cladophlebis, Lastrea, Dryopteris, 

Anomia, Calamopsis, Sabal, Siphonites, Ficus, Eucalyptus, and Aralia; and the following have 

been detected in the upper but not in the lower: Hhus, Castanea, Betula, and Platanus. 

The lower beds, on account of tho abundance of ferns, gigantic palms, figs, and a number 

of genera now found in the \Vest Indies and tropical South America, may be supposed to have 

enjoyed a much warmer, possibly a subtropical temperature, while the presence of sumacs, 

chestnuts, birches, and sycamores in the upper beds would seem to indicate an approach to 

the conditions prevailing at the present day. 

A number of species of plants have been found to be common to the west and cast sides 

of the Cascades. This number is not large, but they are important and easily recognized forms, 

and there is indication that tho number will be increased when the material in hand has been 

more thoroughly studied. This would indicate that approximately similar conditions of climate 

and topography prevailed throughout this general area during the Puget epoch. The Cascade 

Hange as it now exists did not then intervene. 

The Puget group is well described by George Otis Smith, 754 who brings together 

the data quoted above, with additional details. 

M 10. SOUTHERN BRITISH COLUMBIA. 

At the junction of Similkameen and Tulameen rivers, British Columbia, is a. 

basin containing strata assigned by Camsell 129a to the Oligocene: 

These sedimentary rocks alorie in the northern part of the district cover an area of nearly 

50 square miles, the basin being 14 miles long with a variable width of from 3 to 5! miles. 

They consist of thick beds of sandstone, with clay, shales, and several seams of lignite. The 

base of the series appears to be a very coarse grained sandstone containing many large rounded 

white feldspars in a matrix of calcareous material. This rests on the eastern side of the basin, 

on the Copper Mountain series of rocks [monzonite], while on nearly all other boundaries the 

sediments dip under the more recent volcanic rocks, which lie as sheets on them. In parts. 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 781 

also these volcanics have thrust themselves through the sediments and now appear as islands 

in the older rocks. The strata do not now lie horizontally but have been tilted at low angles, 

making an irregular series of folds. Some faults also occur. 

Many drill holes have been bored in this Tertiary basin in search of lignite seams, and 

with some good results. Most of them, however, were put down at or near the edge of the 

river, and only one near the western edge of the basin. * * * These have disclosed the 

thickest lignite seams to be in the vicinity of the town of Princeton, where a bed over 18 

feet in thickness was struck at a depth of 49 feet below the surface. The hole in which this 

seam was found was sunk near the bridge over the Similkameen River to a depth of 280 feet. 

In this hole lignite seams aggregating 35 feet 7 inches were crossed in the first 90 feet, while 

the rest was in shales and sandstones. 

Several drill records are given, the strata having been penetrated in one hole 

to a depth of 1,000 feet. In regard to the character of the lignite, Camsell states: 

Though these beds are of the same age as the Coldwater group of the Nicola country, in 

which coal also occurs, there is a difference in the quality of the fuel contained in each. The 

Nicola coal is a true bituminous, whereas this is a lignite. The former, also, is considerably 

higher in fixed carbon and lower in water, while the fuel rate is 1.447, as against 1.108 of the 

Princeton coal. 

Some of the beds of the Princeton coal basin are only in a primary st:fge of formation, 

and they still show the brown, woody fiber of the slightly altered vegetable remains. Much 

retinite also occurs in them. Some also have been completely destroyed by combustion, and 

it is to the combustion of an underlying bed of lignite that Dr. Dawson attributed the 

metamorphism and color of the rocks at the Vermilion Bluffs. 

M-N 11-12. GREAT PLAINS, ALBERTA. 

The Eocene of the Great Plains in Alberta is the Paskapoo series of the Canadian 

Survey, the so-called "Upper Laramie," which is areally continuous with the Fort 

Union and is approximately its equivalent. Beneath the Paskapoo lies the 

Edmonton, which is classed as Cretaceous by Stanton on the evidence of brackishwater faunas and dinosaurian remains, whereas by Knowlton it is placed in the 

Tertiary on account of the flora which it contains. The Canadian Survey regards 

the Edmonton as Cretaceous. Both these formations are mapped as earliest 

Tertiary or latest Cretaceous (5a). 

Tyrrell's original descriptions 816a of the Edmonton and Paskapoo are in part 

as follows: 

The Edmonton series is perhaps, on the whole, the most characteristic series of the entire 

region, for though its thickness, wherever determinable, was never found to exceed 700 feet, 

the horizontal position of the strata causes it to underlie a very large extent of country. 

It consists generally of whitish or light-gray clay and soft clayey sandstone, weathering 

very rapidly with more or less rounded outlines. In some places, as on Red Deer River and 

in the Hand Hills, it is seamed with a great number of beds of ironstone, which, with thin 

beds of lignite and lignitic shale, give a definite banded character to all the escarpments. It 

also contains a great number of nodules of compact ironstone, which are often perched on 

little pinnacles cut out of the soft sandstone. In the northern portion, especially along the 

North Saskatchewan, the banded appearance is seldom seen, though, with the exception of a 

smaller quantity of ironstone, the rock has very much the same character as farther south. 

This is essentially the coal-bearing horizon within the district, all the coal found east of 

the foothills, except probably the seams on the upper North Saskatchewan and at Egg Creek, 
782 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

being of this age. The top of t'he formation is marked by an extensive coal deposit, seen first 

in the Wintering Hills as a thin bed of carbonaceous shale, but on being traced northward is 

found to thicken very greatly, till on the North Saskatchewan, near Goose Encampment, it 

has a thickness of 25 feet. The bottom of the series lies conformably on the Pierre shales, 

without any sharp line of demarcation between the two. In fact, the shales gradually lose 

their massive character and change almost insensibly into thin beds, which are of decidedly 

brackish-water origin. In the Pierre remains of land plants and animals are very rare, while 

here traces of land plants become fairly plentiful, and on Red Deer River dinosaurian bones 

are met with in great abundance, showing, with the presence of estuarine shells, the partly 

land-locked character of the area within which the beds were deposited. 

* * * * * * * * * 

Under the Paskapoo series we group all the Laramie rocks lying above those of the 

Edmonton series; thus it will include Dr. Dawson's Porcupine Hills and Willow Creek series 

and all but the lowest 700 to 900 feet of his St. Mary River series. On the plains no place 

was seen where its total thickness could be measured, but at the outer edge of the foothills, 

on Little Red Deer River, a thickness of 5, 700 feet at least was determined, the bottom of the 

formation not being seen, and it is probable that a considerable thickness had been denuded 

from the top. 

The beds consist of more or less hard light-gray or yellowish, brownish-weathering sandstone, usually thick bedded but often showing false bedding; also of light bluish-gray and 

olive sandy shales, often interstratified with bands of hard lamellar ferruginous sandstone, and 

sometimes with bands of concretionary blue limestone, which burns into an excellent lime. 

The sandstones consist of very irregular though slightly rounded grains of quartz, feldspar, 

and mica, cemented together in a calcareo-argillaceous matrix. 

The whole series, as shown by its invertebrate fauna, is of fresh-water origin. 

N 4. cmCHAGOF COVE, ALASKA PENINSULA. 

Palache 628 distinguished marine sediments containing abundant fossil remains 

which show them to be of lower Eocene age. He described the terrane as the Stepo- ' 

vak series and divided it into lower and upper beds. The lower beds comprise coarse 

breccias or agglomerates and fine tuffs composed wholly of igneous material. The 

coarse agglomerates contain angular fragments, a foot or less in diameter, of white 

or greenish porphyry, and rarely granite. They are cemented by comminuted material which consists essentially of interwoven hornblende needles. Although macroscopically the rocks are varied in appearance, microscopically they are very similar. 

They are pyroclastic, but some exhibit a little evidence of water sorting and others 

may be called flow breccias. They contain pecten-like fossil shells which are too 

imperfect for determination. The upper beds consist of soft shales, sandstones, 

and grits, with some thin beds of limestone and here and there a chert band. 

After describing local sections and the folded structure of the Stepovak series, 

Palache continues: 

Concerning the fossils collected fr?m this formation Dr. Dall says: "The fossils from the 

Stepovak beds are Eocene, probably of about Claiborne age (middle Eocene), and are the only 

typical Eocene yet discovered in Alaska." 

(See quotations in regard to the age of the Kenai under 0-P 5, Kenai Peninsula, pp. 785-787, and 0 4-5, Alaska Peninsula, pp. 783-784.) 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 783 

N 4, 0 4-5. ALASKA PENINSULA. 

The general geology of the Alaska Peninsula was thus stated by Stanton and 

Martin: 786 

The Alaska Peninsula contains a coarse crystalline core of granite or of similar rocks, flanked 

on the eastern side by Mesozoic sediments and on the western side by late Tertiary or postTertiary beds. The Mesozoic beds are overlain in places by early Tertiary formations. Both 

the Mesozoic and the Tertiary beds are cut by andesite and basalt. The intrusion and volcanic 

outflow has continued from late Jurassic time until the present, the region containing Mveral 

active volcanoes. 

The structure of the region is varied. The west shore of Cook Inlet has its general position 

outlined by a number of great overthrusts, by which the Triassic rocks have been brought in 

contact with the Upper Jurassic. The Alaska Peninsula is a region of open folding, with the 

folds crosscut by an irregular series of faults. 

At Herendeen Bay Atwood/2a in 1908, distinguished the following section: 

Geologic sequence in western part of Alaska Peninsula. 

----------,- ·-----------------

Age. Geographic distribution. I 

-~-- - -----~------·-· 

Recent .............. _ Pleistocene ......... . 

Post-Mioccn<: .. _ .. _ .. 

Stream valleys ......... _._ 

Lowlands and along valleys. 

U nga Island, Fopof Island, 

Balboa Bay, Port Moller, and Chignik Bay. 

Miocene ............ _ .

1

, Unga and Popof islands, 

Balboa and Herendeen 

bays, and Port Moller. 

Eocene ........... _._ Chignik Bay, Unga Island, 

center of Alaska Peninsula, and Hcrendcc>n 

Bay region. 

Upper Cretaceous .. _ Chignik and Herendeen 

bays. 

I 

Lithologic character. Thickness 

(feet). 

Sands, muds, and gravels ... - ..... _ ...... _. Unconsolidated clays, sands, _ .... ____ .. _ .. 

gravels, and glacial drift. 

Tuffs, agglomerates, brec- . _ .. _. _ .... __ . cias, and flows. 

Loosely cemented clays, 

sands, gravels, and con- glomerates. Some beds 

furnish abundant marine 

fossils. 

Shales, sandstorws, grits, 

and conglomerates. Locally carries lignite. 

Conglomerate, sandstone, 

and shales, with coal scams. 

Up to 5,000 

600+ 

Lower Cretaceous... . Herendeen Bay....... . . . . Shale, sandstone, and cal- 1,800+ 

Upper Jurassic ....... Chignik and Herendeen 1,000+ 

bays. 

Atwood's comment follows: 

careous sandstone. 

Sandstones, conglomerates, 

and arkose. 

Remarks. 

Many volcanic de 

posits still show cone structure. 

These deposits usu- ally occur in very 

small areas. 

Carries workable 

lignite b cd at Coal 

Harbor. Occupies a very large 

part of Alaska Pen 

insula in Herendeen Bay region. 

Contains valuable 

coal beds at Chignik and Herendeen bays. 

Eocene, Miocene, and post-Miocene formations are exposed in this portion of the peninsula. The Eocene strata include at least 5,000 feet of sandstone, shales, conglomerates, and 

seams of lignite and form the central portion of the Aleutian Range in the Balboa-Herendeen 

Bay district. They extend westward at least as far as Pavlof Bay and eastward to the Chignik 

Bay region. Several collections of fossil shells and plants have been procured from these beds. 

The shells are those of marine invertebrates and have been determined by W. II. Dall to be of 

upper Eocene age. Mr. Dall reports that some of the material from these strata may be upper 

Eocene or Oligocene. The plants, as determined by F. II. Knowlton, are all of Kenai age. 

They were procured from beds that are interstratified with those from which the shells were 
784 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

obtained. Kenai plants from Alaska have been determined by Mr. Knowlton to be of upper 

Eocene age and the harmony between the age determinations of the plants and animals is 

exceedingly satisfactory. The nature of the Eocene deposits indicates that the area of sedimentation was several times just below sea level, probably near to shore, and at other times 

above sea level, receiving wash from higher lands, or overgrown by dense growths of vegetation. 

0 5. KODIAK ISLAND AND KATMAI BAY. 

Dall 210 refers as follows to Katmai Bay and Kodiak Island: 

Katmai Bay, some miles westward from Amalik Harbor, is the site of a village and trading 

station. The portage across the mountains of the peninsula ends here. On this portage both 

coal and petroleum have been found, the exact locality not being stated. The latter is a dark 

lubricating oil, which is said to float on the surface of certain ponds or lakes. No information 

could be obtained about the coal, but it almost certainly belongs to the age of the Kenai beds. 

* * * * * * * * * 

Tertiary beds occur in various places on the islands of the Kadiak group, both of Kenai 

age and of the later Unga beds containing Miocene marine fossils. 

On the island of Kadiak marine Miocene strata are found, and among the specimens brought 

back by Wossnessenski were clay ironstones containing plant remains referable to the Kenai 

group. These stones were used by the native women for reddening the inner surface of dressed 

skins, and the only indication of locality for them is that they came from the northern part of 

the island. About the middle of the island, surrounding Ugak Bay, at the old settlement of 

Orlovsk and on the northern shore of Miliuda Bay next southward, and on the opposite side of 

the island, part of the shores of Uganuk Bay and of Uganuk Island in the bay, sandstones with 

lignite in thin seams, overlain in places by marine sandstones like those of Unga, are reported . 

on the authority of Kharitonoff and other Russians familiar with the island. 

0 8. SOUTHEASTERN ALASKA. 

During the season of 1907 Atwood visited the two localities in southeastern 

Alaska where Eocene strata had been reported/53a and he has furnished the following 

information. On the shores of Hamilton Bay, Kupreanof Island, there is a small 

area of sandstones, shales, conglomerates, and lignite, which lithologically resemble 

the Kenai formation of other portions of Alaska. The localization of these strata 

to a somewhat restricted basin is also suggestive of the Kenai. They rest unconformably upon much-deformed beds of Triassic age and older and are overlain unconformably by glacial drift and recent alluvium. The flora obtained from a stratum 

not more than 15 feet in thickness contains, according to F. H. Knowlton, Upper 

Cretaceous cycads, possibly redeposited from older strata, and many typical Kenai 

plants. 

At Killisnoo Inlet, an irregular reentrant on the west shore of Admiralty Island, 

sandstones, shales, conglomerates, and lignites outcrop on the shores. These strata 

have the same character as those near Hamilton Bay and are of similar small extent. 

They rest unconformably upon strata that are considered to be of Paleozoic age, 

and on their truncated edges there is some glacial drift. No record of animal life 

was found in this locality, but the plant remains contain Upper Cretaceous and 

Kenai (Eocene) forms. 

At these two localities in southeastern Alaska the stratigraphic and floral 

studies seem to indicate a period of continuous deposition from late Cretaceous 

time into Eocene time. Such conditions prevailed in other portions of Alaska. 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 785 

0 10. FINLAY AND OMENICA RIVERS, BRITISH COLUMBIA. 

McConnell, 562e in his report on Finlay and Omenica rivers, British Columbia, 

says: 

Beds consisting of conglomerates, interbedded in places with shales and sandstones, occupy 

the bottom of the valley of the Finlay from the Ingenica River north to the Tochieca and continue northward along the valley of the latter stream. Similar beds appear again on the Finlay 

a few miles farther west in a parallel longitudinal valley, which it enters and follows for some 

distance. They are also found on the Omenica from the Black Canyon up to its junction with 

the Tchutetzeca. 

The pebbles of the conglomerate are usually small but in places are several inches in diameter. They consist mainly of slate, quartz, and limestone. Oxide of iron is occasionally present 

in the matrix in sufficient quantities to give a reddish coloration to exposures. The shales are 

dark in color, are evenly bedded, and are interstratified in places with small lignite seams. The 

sandstones are usually somewhat argillaceous and occasionally consist largely of mica derived 

from the .disintegration of the underlying schists. 

The Tertiary conglomerates and associated rocks * * * are distributed in narrow 

strips along the deep valleys of the district and were nowhere found on the highlands. They 

were probably deposited in lakes during a Tertiary depression and evidence the pre-Tertiary 

age of the present main river channels. The conglomerates are occasionally horizontal or 

nearly so, but in most cases they are tilted at angles ranging from 10° to 40°, showing that they 

have been affected to some extent by the later mountain-making movements. 

Some leaves and other plant remains, obtained from the shales interbedded with the conglomerates, were examined by Sir J. William Dawson, who lists eight species and concludes: 

"All the above fossils, so far as determinable, appear to indicate the Upper Laramie period. 

Of the collections in my possession, the plants seem most nearly to resemble those of the Lignite 

series on the Mackenzie River, which are referable to the Upper Laramie. There is nothing 

among the plants to indicate any other horizon." 

Knowlton regards these deposits as of Fort Union age. 

0-P 5. KENAI PENINSULA. 

Kenai Peninsula lies between Cook Inlet and the ocean and is the type locality 

of the Kenai formation. The strata have been recently studied by Moffit and 

Stone, 602 who state: 

The upper member of the list of bedded sedimentary rocks [of Kenai Peninsula] is a succession of sandstones and shales, with interbedded coal seams, which overlies the lower Jurassic 

unconformably and forms the whole northern coast line of Kachemak Bay and the eastern coast 

line of Cook Inlet as far north as Cape Kasilof. Isolated masses of these rocks also occur at 

various points on the south shore of the bay. These beds, while slightly folded and sometimes 

faulted, are not always thoroughly consolidated. They were described by Dall and furnish the 

type exposures of the Kenai beds. * * * This formation, consisting of partly consolidated 

sandstones and shales, is of economic importance because of the lignitic coal seams interstratified 

with its various members. As previously pointed out, it rests unconformably on the Seldovia 

lower Jurassic rocks. 

Fossils from the Kenai beds of Port Graham and Ninilchik were described by Heer as 

early as 1869. The former locality was afterward visited by Dall,a who collected fossils there, 

as well as from other localities on the north side of Kachemak Bay. The Kenai beds probably 

underlie the whole of the Kenai Plateau, but their northward dip carries them below sea level ------------------------~-

a Dall, W. H., Report on coal and lignite of Alaska: Seventeenth Ann. Rept. U. S. Geol. Survey, pt. 1, 1896, 

pp. 787, 842. 

48011°--12-50 
786 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA . 

. a few miles south of Kasilof River, and they do not appear again. These coal measures were 

thought by Heer to be of Miocene age, but Dr. Dall referred them to the Oligocene and gave a 

list of plant and animal remains collected at Port Graham, among which are both Coniferre 

and broad-leaved trees, the total number of species amounting to 44. He says: "The deposit 

appears to have formed at the bottom of a lake." 

Dr. F. H. Knowlton in the same report a gives a list of plant remains from the Kenai formation collected by Dr. Dall in 1895, as well as those previously known from the same region, 

and states that they are believed to be of Eocene or Oligocene age. 

Later, in speaking of the typical Eocene strata of Chichagof Cove, Dr. Dall b says:. 

"The only representative of the Eocene epoch known in Alaska previous .to the Harriman 

Expedition was the Kenai series (formation), which had been referred by Heer to the Miocene 

and by others to the Eocene but which has of recent years been recognized as Oligocene by the 

present writer and others." 

In the same publication c Dr. Knowlton, after describing a collection of fossil plants from 

Kukak Bay, makes this statement concerning their age: 

"It is hardly necessary at this time to go into a history of the plant-bearing horizons of 

·Alaska. * * * It is sufficient to state that the named species above enumerated are typical 

of the so-called Arctic Miocene, which is now regarded as of the age of the upper Eocene. The 

species described in this paper as new are in various ways allied to forms characterizing this 

·horizon, and I do not hesitate to refer this collection to the upper Eocene." 

The determination of marine Oligocene invertebrates and upper Eocene floras 

-from nearly related strata may seem to suggest that there was a sequence of deposits 

which included the two terranes, but Atwood's results of 1908 appear to indicate 

· "tp"at the Kenai pla:q.ts are associated with marine Eocene fauna. (See pp. 783-784.) 

' Moffit and Stone continue: 

The Kenai fo~mation as exposed in Kachemak Bay is composed of soft light-gray sandstones and clay shales, with numerous interspersed coal seams. Four partial sections of the 

formation aggregate 1,763 -feet of strata. * * * [They contain] seams ranging in thickness 

from a few inches to 7 feet. * * * The sandstones are medium grained, soft, light gray, 

sometimes iron stained, and occur in beds from a few inches to 30 feet thick. Cross-bedding was 

· noted at one horizon. Some portions of the heavier beds of sandstone are hard and weather 

out in nodular blocks. In these blocks the best-preserved fossil plants are sometimes found. 

In one locality lenses of grit occur in a sandstone mass. The pebbles in the grit are smaller 

than one-half inch in diameter and are mostly quartz. Dall d reports conglomerates in the 

- Kenai series on Kachemak Bay, but the author found none in the portion he visited. Sand-

' stone at places grades into sandy shale. 

The shales of the Kenai formation on Kachemak Bay are all light-colored clay or mud 

, rocks, grading on one side into arenaceous shale and on the other into clay. The shales are soft 

and crumbly on the outcrop and when wet become plastic. Beds of clay that have been baked 

by the burning of coal seams are red and hard. Small blocks of gray hard limestone were found 

at one locality and suggest that calcareous sediments in small amount may be contained in the 

formation. Limestone was not seen in place. 

The abundant coal seams in the Kenai rocks of this field are all lignite. They vary in 

thickness from mere streaks to beds several feet thick. Eldridge e counted 36 seams along the 

a Dall, W. H., Report on coal and lignite of Alaska: Seventeenth Ann. Rept. U.S. Geol. Survey, pt. 1, 1896, 

p. 876. 

b Alaska, geology and paleontology: Harriman Alaska Expedition, vol. 4, 1904, p. 101. 

c Idem, p. 162. 

dDall, W. H., Report on coal and lignite of Alaska: Seventeenth Ann. Rept. U.S. Geol. Survey, pt. 1, 1896, p. 789. 

e Eldridge, G. H., A reconnaissance in the Susitna basin, Alaska: Twentieth Ann. Rept. U. S. Geol. Survey, 

pt. 7, 1900, p. 21. 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 787 

beach at Tyonek, varying in thickness from a foot to 1.5 feet, and Kirsopp a figures 73 seamB on 

the nor.th shore of Kachemak Bay. Much of the Kachemak Bay lignite, especially that in the 

lower beds, is hard and glossy, clean to handle, and tends to break cubically. The higher beds, 

however, are dull and lighter and show more woody fiber. 

The thickness of the formation exposed in Kachemak Bay has not been determined, and it 

is almost impossible of determination because there are stretches over which the beds can not be 

traced. Anchor Point is near the base of the formation, but it is not known how far the coalbearing rocks extend beyond the head of the bay, except that coal has been found 15 miles up 

Sheep Creek. Kirsopp b published a section from Anchor Point to the head of the bay, including 2,683 feet of coal-bearing measures. This section contains at least 126 feet of lignite in 

seams over 2 feet thick. Estimated roughly, there probably are about 1,500 feet of strata 

between Bluff Point and the base of Coal Point. From Coal Point to McNeil Creek the dip is 

strong and 3,000 feet may be a low estimate. From McNeil Creek to the top of the bluff at 

Falls Creek at least 1,000 feet are exposed. Hundreds of feet of strata probably overlie the section measured at Falls Creek and outcrop in the bluff north of the head of the bay. The writer 

is inclined to think that 10,000 feet may not be a high estimate for the thickness of the Kenai 

formation in the Kachemak Bay field. 

P 3. NUNIVAK ISLAND AND YUKON DELTA. 

Dall 210a reported an occurrence of sandstones, probably Kenai, at Etolin Harbor, 

Nunivak Island, but G. M. Dawson 260 describes the rocks as "cellular olivine diabase" and the island as composed of nearly horizontal basaltic flows. 

Cape Vancouver is a prominent point rising from the flats of the Yukon Delta 

and composed of sandstone and sandy shales, capped by basalt flows in the higher 

hills. Dawson says: 

The north shore of the cape, which alone was examined, forms scarped bluffs or cliffs,. rising 

from the edge of the sea, and presenting fine exposures of sandstones and sandy shales, well 

bedded and dipping southward, at low and undulating angles. At the extremity of. the cape 

these beds appeared to be horizontal, and on the south side, though imp~fectly seen from a 

distance, they seem to lie at higher and more irregular inclinations. 

The sandstones, where examined, are gray, bluish and brownish in color, rather .soft, and 

sometimes nodular. They con tam a few very thin and dirty seams of coal or lignite, of which 

the thickest seen was only a few inches. There are also in the sandstones numerous carbonaceous fragments and occasional fossil leaves, of which a couple were collected. · 

Sir William Dawson found these plants to represent J uglans acuminata and 

assigned them to the Miocene. The horizon is now placed in the upper Eocene by 

Knowlton. 

P 5. COOK INLET NEAR TYONEK. 

The exposures of the Eocene on the west shore of Cook Inlet, about 3 miles 

south of the village of Tyonek, and the beltlike continuation of the strata to the 

northwest at least as far north as Beluga River have been called Kenai and consist 

of sandstones, shales, conglomerates, and some lignite. None of the material, so 

far as known, is of marine origin. The deposits are such as to suggest estuarine 

origin or sediments laid down on the land adjoining bodies of water. In the section 

exposed along the shore of Cook Inlet, more than 2,000 feet of sediments are 

shown. The beds are but slightly deformed. The base of the formation is not 

exposed, the eroded surface of the upturned beds being mantled by glacial drift'. 

a Kirsopp, J., jr., Coal fields of Cook Inlet, Alaska: Trans. Inst. Min. Eng., London, 1901. b Idem, p. 3. 
788 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

, Plant remains which have been obtained from this locality have all been determined by Knowlton to belong to the Kenai, or to be of upper Eocene age. The 

exposures along the beach near Tyonek were described by Spurr 771 in 1900. The 

Yentna and Hayes River beds of Spurr, which occur north of Tyonek on the lower 

Susitna and in Skwentna Valley, are now also regarded as of Kenai (Eocene) age. 

P 6. MATANUSKA VALLEY. 

Matanuska River enters Cook Inlet at its northeastern embayment. It comprises a large area of coal-bearing strata classed as Kenai (Eocene) and described 

by Paige and Knopf 627 as follows: 

The Kenai of the Matanuska basin comprises a series of sandstones, shales, arkoses, numerous coal seams, and a large volume of conglomerate. The rocks are well indurated and, as 

first noted by Mendenhall, resemble the Paleozoic coal measures of the Appalachian region. 

The sandstones are gray, hard, and tough and are characteri.zed by the presence of silvery shreds 

of white mica. At some localities, as in the leaf-bearing strata in the Kings Creek coal measures, 

the sandstones contain shale fragments. The shales show no unusual features; they are dark 

bluish, fissile, and interstratified with the sandstones in very regular beds. The arkoses were 

noted only on the ridge north of Tsadaka Creek, abutting against the quartz diorite mass. They 

are composed of feldspar, quartz, and chlorite and locally contain granite pebbles. Certain 

strata are fine examples of regenerated granites. 

Conglomerate is found at Castle Mountain, between Kings and Chickaloon creeks, and at 

Conglomerate Mountain, between Tsadaka and Eska creeks. At both places the deposit 

is at least 1,000 feet thick. Thin sandstone beds, not exceeding a few feet in thickness, are 

intercalated with the conglomerate and pinch out along the dip. The pebbles of the conglomerate are well worn and possess a well-defined shingling. Their diameter averages 4 inches and 

ranges up to 8 inches. Greenstone porphyries form the principal material of the conglomerate, 

with some quartz prophyry and very rarely some granite and vein quartz. The matrix of the 

pebbles is a grit. 

* * * * * * * * * 

Heavy beds of conglomerate dipping to the north can be seen on the east side of Chickaloon 

Creek. They are part of a great series of sandstones, shales, and conglomerates, probably not less 

than 3,000 feet thick, which are overlain by basaltic porphyries at an elevation of about 4,700 

feet. 

The coal of the Kenai of the Matanuska basin is bituminous except where modified by 

igneous rocks. The seams vary in thickness up to a maximum of 17 feet. 

The age of these strata has been determined by Knowlton as Kenai (upper 

Eocene). Fresh-water gastropods have also been found in them. 

P 6-7. CONTROLLER BAY TO CAPE YAKATAGA. 

On the southern coast of Alaska, in latitude 60°, Tertiary sediments which 

resemble the Kenai in character but may be younger have been examined on Controller Bay and are known to extend east to Cape Yakataga. They have been 

classified in several formations and described in detail by Martin,S73a who says: 

The Tertiary sediments * * * consist of monotonous repetitions of shales and sandstones, with an included mass of coal-bearing arkose and one or more massive conglomerates. 

The total thickness, as .shown in the following table, is many thousand feet. The structure of 

the region in which these rocks outcrop is complex, exposures at critical points are often wanting, 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 789 

and neither the lithologic character of the beds nor the fossils which they contain are sufficiently 

distinctive to make it possible to recognize with certainty the complete stratigraphic succession. 

The presence of two easily recognized horizons, the arkose and the conglomerate, give 

distincti~e character to two parts of the stratigraphic column. The arkose, with its associated 

coal, is restricted in areal distribution to the region north of Bering Lake, and the conglomerate 

to the region south of the lake. Between these regions are areas of no outcrops, and none of 

the beds of either region can be recognized with certainty in the other. 

Section north of Bering Lake. 

Tokun formation: 

a. Sandstone ........................................................ ·· ... ····· ... . 

b. Shale with thin, flaggy sandstones and with occasional calcareous concretions ........ . 

Kushtaka formation: 

Feet. 

500 

2,000+ 

c. Arkose with many coal beds and with some shale and sandstone .................... 2,500± 

Stillwater formation: 

d. Shale and sandstone ............................................................. l,OOO+ 

Section sonth of Ber1"ng Lake. 

Katalla formation: 

e. Conglomerate and conglomeratic sandstones interbedded with shale and sandstone .... . 

f. Flaggy sandstone ............................................................... . 

g. Soft shale with calcareous concretions and with bed of glauconitic sand near base ..... . 

h. Sandstone ........................ : ............................................ . 

i. Soft shale ...................................................................... . 

Feet. 

2,500 

500± 

2,000 

1,000 

500+ 

The succession in each of these sections may be assumed as reasonably correct, although 

there is a possibility that the thicknesses are too great because of there having been repetition 

of the less characteristic beds by faulting. The correlation of the beds of one section with 

those of the other rests at present upon evidence which is incomplete and unsatisfactory and 

must be regarded as suggestive rather than conclusive. It is probable that one of two correlations is true: The shale and sandstone of the Stillwater formation (d) may overlie the conglomerates (e) of the Katalla formation with a concealed interval of unknown extent between 

them, or a and b may be identical with hand i. In the former case the conglomerates underlie 

the coal field; in the latter case the coal underlies all, or nearly all, of the entire region under 

discussion. The stratigraphic and structural field evidence proves nothing either way but 

suggests, as the most probable relation, that the entire section north of Bering Lake overlies 

the section south of the lake. 

The Tertiary rocks contain fossils at many localities, but they are usually poorly preserved 

or not characteristic. They consist chiefly of leaves and of marine Mollusca, but include also 

a few echinoids, Crustacea, fish, and fresh or brackish water Mollusca. 

* * * * * * * * * 

The paleontologic evidence may be summarized as follows: a 

1. The marine Mollusca from the sandstone of the Tokun formation are either so poorly 

preserved as not to admit of specific identification or belong to undescribed species. b They 

are almost certainly Miocene, but can not be definitely correlated with any known Miocene 

faunas of other regions. 

2. The plants from the coal-bearing rocks include poorly preserved individuals which 

suggest species of the Kenai formation of Cook Inlet, generally considered to belong in the 

upper Eocene or Oligocene. The best-preserved specimens, however, represent species which 

are not known in the Kenai and which are suggestive of later Tertiary age. There is no positive 

evidence that the exact equivalent of the Kenai occurs in this region. 

a Data furnished by W. H. Dall and Ralph Arnold on the Mollusca, by F. H. Knowlton on the plants, and by 

W. B. Clark on the echinoids. 

b This statement applies to all the faunas of this region. 
790 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

P 6-7. MOUNT WRANGELL DISTRICT. 

Moffit and Knopf 600a thus refer to the local occurrence in the Mount Wrangell 

district of deposits which are provisionally assigned to the Tertiary. 

A formation consisting of soft, thin-bedded shales and sandstones, associated with large 

.. amounts of well-rounded conglomerate composed mainly of diorite cobbles, occurs in the region 

of Coal Creek, north of White River, near the international boundary. The area in which these 

rocks are exposed is small, but there is some probability that they underlie the volcanic cappings 

of the mesas which form prominent features of this part of the White River region. 

The strata lie nearly horizontal and rest upon older rocks which stand on edge. In places 

they are lignitiferous, and petrified wood of exogenous character is common as float in gulches 

cutting the formation. 

The resemblance of these rocks to those of similar patches scattered throughout the Yukon 

basin a leaves little doubt as to their Tertiary and probably Kenai age. Rocks of identical 

character occur near the head of Chitistone River and, like those of the White River region, 

are covered by a heavy series of volcanic flows. 

P-Q 5-6. FOOTHILLS OF THE ALASKA RANGE. 

The Bonnifield and Kantishna placer districts lie on the northern slopes of the 

Alaska Range. In course of prospecting for gold, lignites have been located and 

the field is thus described by Prindle : 639 

Deposits containing lignite coal have a wide distribution in the northern foothills of the 

Alaska Range, but the only section to be considered here is that extending east from Cantwell 

River to Wood River, a distance of about 50 miles, and northward to the flats. The low spaces 

within this area between the east-west ridges of old metamorphic rocks are occupied by these 

deposits. They are for the most part but slightly consolidated and have been so deeply incised 

by the drainage systems that in places nearly complete sections are exposed. That the present 

areas are only a part of masses formerly much larger in extent is shown by small isolated p~;~,tches 

of these deposits that lie slantingly on the upper slopes of ridges and by well-worn pebbles 

derived from them that lie scattered on the tops of the highest ridges, 1,500 to 2,000 feet above 

the occurrences of the valleys. These deposits have been folded, the flexures being for the 

most part broadly open, with dips of 30° to 35°, but locally closer, with resultant vertical dips 

attended in places by consolidation of the gravel beds to conglomerate; in addition, here and 

there parts of the deposits have been faulted. 

The material comprises alternating beds of sands, clays, coal, and gravels that are divisible 

into three parts-an underlpng white deposit composed of angular and some well-worn, subangular, fine quartz gravels, with a large admixture of kaolinic material where the bedrock is 

feldspathic; an intermediate member of yellowish cross-bedded sands and fine well-worn 

gravels, dark plastic clays, and coal beds; and an upper member composed almost entirely of 

gravels. The feldspathic schists produce by weathering a large amount of white clay, and the 

quartz veins which in places in these rocks are very numerous furnish abundant quartz material~ 

and these characteristics of the old bedrock have gone over into the basal members of the sediments. The transition from the decomposed products of the schists that still retain their 

structural position to the same materials in the overlying deposits is in some places strikingly 

exhibited. The thickness of these underlying deposits was not determined, but one section 

was observed in which 100 feet of them was exposed. The sands and clays of the intermediate 

member are naturally less conspicuous than the underlying beds but have in many places 

become indurated by the burning of the coal beds and baked to a conspicuous red color. The 

a Collier, A. J., Coal resources of the Yukon, Alaska: Bull. U.S. Geol. Survey No. 218, 1903, p. 19. 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 791 

overlying gravels at the localities where their relations to the underlying deposits were observed, 

whether in horizontal or tilted strata, were found to be structurally conformable. They are 

characterized by a yellow color. They include both fine and coarse material, are well worn 

and well rounded, and the predominant constituents are white quartz and chert of various 

colors, principally black. There is a considerable proportimi of metamorphic rocks and many_ 

pebbles of compact chert conglomerate. In the upper part of the gravels, in strong contrast. 

with their medium to fine grained material, are locally many bowlders of granitic rocks and· 

diabase and a few well-rounded bowlders of dense chert and quartzite conglomerates. The 

greatest observed thickness of these deposits was approximately 3,500 feet. The upper gravels 

constitute about half of the entire deposit. 

Fossil leaves are observable nearly everywhere in the beds associated with the coal, but· 

except where these beds have been baked by the burning of the coal the fossils are poorly· 

preserved. The age of the coal-bearing member has been determined as Kenai. The age of· 

the gravels has not been determined, nor is it definitely known that they are chronologically 

conformable with the underlying deposits, but they have been folded at every point where 

folding was observed, along with the underlying deposits. Where valleys have been extensively 

developed in these deposits bench gravels have in many places been laid down on the truncated 

edges of the older deposits, and where these older beds are horizontal the bench gravels are 

in apparent conformity with them, obscuring the relationship. It is probable that deposits 

of various ages since the Kenai, formed under varied conditions of sedimentation, occur in this 

area and that the coarse material in the uppermost part of the gravels owes its origin to 

glaciation. 

Parts of the gravel members of these deposits are auriferous and have supplied the gold 

for the Bonnifield region. There is a marked resemblance between these coal-bearing deposits, 

with their thick beds of overlying gravels, and the Kenai beds of the Seventymile Creek area 

near Eagle, with their coal-bearing deposits and thick beds of conglomerate formed largely 

of the same kinds of material. 

Q 3. SEWARD PENINSULA. 

Moffit/98 in his report on the Fairhaven gold placers, states that "In the northeastern part of Seward Peninsula lignitic coal has been mined in a small basin on 

Kugruk River. The associated strata are sandy and shaly and include thin limestones. Though folded and jointed, they are less metamorphosed than the neighboring schists. No fossils have been found and the age is indeterminate," but the 

rocks are presumably late Cretaceous or early Tertiary. The area is too small to 

be shown on the map of North America. 

Q 3-4. NORTON SOUND. 

Mendenhall 587 mentions the occurrence of coal-bearing strata supposed to be 

of Tertiary age outcropping on Tubutulik and Koyuk rivers. 

Q 4-5. KOBUK RIVER. 

Strata belonging to the early Tertiary were found by Mendenhall 588 on Kobuk 

(Kowak) River and also farther east on Dall River, in separate local basins. They 

comprise conglomerates, of quartz pebbles with some pebbles of the neighboring 

crystalline rocks, soft sandstones, shales, and lignite beds. On the basis of four 

recognized species of plants Knowlton referred the strata to the "Arctic Miocene" 

(upper Eocene). 
792 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Q 5-6. YUKON VALLEY. 

Spurr 770 distinguished an occurrence of Tertiary strata which he described as 

the Twelvemile beds and provisionally referred to the Miocene or Pliocene. These 

are now regarded as of Kenai (Eocene) age, according to Brooks (personal communication). Spurr says: 

Twelvemile Creek is one of the branches of Mission Creek. Near the point of junction of 

these two streams are exposed in numerous outcrops slightly consolidated and coarse-bedded 

gravels and sands which carry seams of light-brown sandy lignite. Fragments of wood, considerably altered, having a diameter of as much as' 2! inches, are found, but no fossil leaves or 

shells. Occasional pieces of black, shiny lignite, such as is found in the Kenai series and less 

abundantly in the Mission Creek series, occur, but in such a manner as to lead to the suspicion 

that they are fragments derived from these older rocks. The beds are slightly folded, having 

a dip of about 20°. Near the mouth of Twelvemile Creek the dip is southward, though about 

a mile above Twelvemile Creek, on Mission Creek, the dip is to the north, though the strike 

remains nearly the same; thus a shallow syncline is indicated.· 

The rocks of the Mission Creek series, which underlie these beds, are sharply folded, and 

although no actual contact was seen, it is probable that an unconformity exists. Below Mission Creek the rocks of the Kenai series are well indurated, forming compact conglomerates and 

sandstones, and they are apparently conformable with the rocks of the underlying Mission 

Creek series, with which they are infolded. It appears, therefore, that the Twelvemile beds 

can not be correlated with the Kenai series, and yet they are older than the horizontal Pleistocene silts and gravels which are exposed all along the course ·of the Yukon. They may be 

provisionally referred to the Miocene or Pliocene. From their nature they seem to be freshwater lake deposits. 

Q 7. UPPER YUKON. 

A belt of coal-bearing, probably fluviatile deposits crosses the international 

boundary in the Yukon Valley. The occurrences on the Alaskan side of the line 

are described by Brooks and Kindle : 103a 

The Kenai formation has usually been described as occurring in local basins, either of 

lacustrine or fluviatile origin. That described here appears, in part at least, to be of fluviatile 

origin. The distribution * * * indicates that a belt of the Kenai rocks runs parallel to 

the Yukon from Eagle to Birch Creek. While this zone has not been traced continuously, it is 

sufficiently well known to justify the opinion that it was originally deposited as one continuous 

belt. * * * The conglomerate of the Kenai on Woodchopper Creek and Seventymile has 

been found to be auriferous, which lends weight to the assumption that the deposits are of 

fluviatile origin. 

R 5-6. ARCTIC COASTAL PLAIN. 

In traversing the Colville region Schrader 708a distinguished the Eocene and 

Pliocene strata as the Colville series, which he describes as follows: 

The Colville series is named from the large river along which it occurs and is excellently 

exposed. It is a series of Tertiary terranes which underlies the fiat tundra country, or Arctic 

Coastal Plain, that succeeds the more southerly rolling plain formed by the Upper Cretaceous 

or Nanushuk series, which it apparently unconformably overlies, being itself in turn unconformably overlain by the Gubik sands. * * * 

The series consists principally of heavy-bedded silts, soft sandstone, limestone, shale, and 

lignite. It is best exposed along the Colville in the region of the mouth of the Anaktuvuk, where 

it forms steep-faced bluffs about 200 feet in height, extending for a number of miles both up 

and down the river. 
EARLIER TERTIARY (EOCENE AND OLIGOCENE). 793 

The Colville series has been but little disturbed. The beds lie nearly horizontal. * * * 

Observations made along Colville River indicate that the series has a thickness of 500 or 

600 feet. 

On account of difierence in degree of consolidation of the beds, together with their fossil and 

lignite contents, the series has been separated by the writer into two parts, upper Colville and 

lower Colville. It is possible that an unconformity may exist between the lower and upper parts 

of the series, but if present it must be very slight. 

The lower Colville (Oligocene) constitutes the main portion or lower three-fourths of the 

section exposed at the mouth of the Anaktuvuk. It is about 150 feet thick, while the upper 

Colville at this same locality is about 40 to 50 feet thick. The lower Colville contains the more 

indurated class of rocks and consists mainly of partially consolidated silts in beds 6 to 8 feet in 

thickness. They are usually light slate-colored or ash-colored, constitute about one-half of the 

lower Colville section, and are generally much less consolidated toward the top than near the 

base. The harder rocks, which increase in volume toward the base of the section, include 

impure dull-gray medium to fine grained sandstone with detritallignitic plant remains; slatecolored and brownish calcareous shale, with disseminated undeterminable vegetable detritus; 

lignitic coal in layers 1 to 5 feet in thickness; dark slate-colored' or brownish chert, containing 

cavities incrusted with chalcedonic silica; rusty brown, very ferruginous sandstone or impure 

ironstone, and some iron-stained siliceous conglomerate, which also contains lignitic vegetable 

remains. There are also a few layers of hardened silts, forming a rock of very fine texture, 

resembling soft, smooth hone stone. 

The lower Colville is tentatively classed as Oligocene, on account of the presence in it of 

lignite beds and vegetable remains, and from its resemblance to the Kenai beds occurring elsewhere in Alaska, and also on the ground of its relation to the supposed Pliocene silts which it 

immediately underlies. 

The Kenai is now generally referred to the Eocene. For Schrader's description 

of the upper Colville (Pliocene) see Chapter XVII (p. 838). 

R 26-27. NORTHEAST COAST OF GREENLAND. 

N athorst/09 in a report on the geology of northeastern Greenland states: 

The Tertiary is found in two different facies. On Hochstetters Vorland they occupy a 

large territory and are composed of fine-grained yellowish sandstone with impressions of marine 

shells. These are found, according to Copeland, in great quantities, but the collections that 

were here brought together had to be left behind to a great extent on Kuhn Island. The 

specimens that were brought home were .some unidentifiable casts of Cytherea, Venus, and 

Lucina, to which Th. Fuchs later added Astarte and Pecten, after he had again been over the 

collections. This locality deserves to be explored again, but unfortunately the ice rarely breaks 

up and, remaining solid for years, makes the shore seldom accessible from a vessel. 

The rest of the Tertiary is found in connection with the basalts and is covered by them. 

Whether it is also underlain by them is not made clear from the text, but judging from the map 

it would seem to be the case. They sometimes contain layers of coal, and on Sabine Island are 

found fossil plants, namely Taxodium distichum miocenum Hr., Populus arctica Hr., Diospyros 

brachysepala Al. Br., and Celastrus sp., described by Heer. These specimens indicate the flora 

to be contemporaneous with the common Arctic Tertiary flora that Heer considers to be of 

Miocene age [upper Eocene 0), Knowlton]. 
CHAPTER XVII. 

LATER TERTIARY (MIOCENE AND PLIOCENE). 

Oolors, yellow, light yellow, lemon-yellow 

Symbols, 4, 3, 2. 

Distribution: Later Tertiary, where the Miocene and Pliocene are recognized but can not be 

separated or individually identified in the present state of knowledge. The :Miocene is 

separately indicated on the Pacific coast and on the Atlantic and Gulf coasts, so far as_ 

surveys permit. Elsewhere on the map it is comprised with Pliocene under the term, 

"Later Tertiary" (4). The Pliocene is distinguished on the Atlantic and Gulf coasts, so 

far as surveys permit, in California, and in northern Nevada. Elsewhere on the rnap it 

is classed with the Quaternary (1), as in the valley deposits of the Great Basin; or with 

the :Miocene under the headmg "Later Tertiary" (4). The Lafayette formation of the 

Atlantic and Gulf slopes, including the Altamaha of Georgia, is shown only where it completely conceals the underlying formations. 

Oontent: Pacific coast marine deposits; Alaskan Arctic Coastal Plain deposits; fluviatile and 

lacustrine beds of the Interior; western Gulf coast marine formations; and late marine 

Tertiary of Mexico, Central America, and South Amenca. Monterey shale and equivalents of the Pacific coast; beds of Carrizo Creek, California; and marine Miocene of the 

Atlantic and Gulf slopes. Does not include so-called ''Arctic Mwcene" nor'' Old Miocene," 

both of which are included "in "Marine Eocene." :Marine Phocene of the Coast Ranges of 

California; Humboldt formatwn (nonmarine) of Nevada; and marine Pliocene and Lafayette of the Atlantic and Gulf slopes east of the Mississippi, including the Altamaha of 

Georgia; also Yucatan. 

Later T frtiary areas. 

Page, 

B-C 18 ...................... Colombm...... .. . .. .... ... . .. . . . .. .. .. . . . . . . . . . . . . . . . . . . . . . .. . .. .. . . . 796 

C 17 ............................ Panama (See Chapter XVI, pp 711-714) 

E 14-15, F 14, 16, G 12, 14, H-T 11. .Mexico (m part mapped with Quaternary).............................. 797 

E 14 .......................... Oaxaca....... . . .. . . . . . . . . . . . . .. . .. . . . . . .. . . . .. . . . . . . . . . . .. ... . ... 797 

E 15 ........................ Chmpas.............................................................. 797 

F 14 ...................... Vera Cruz and Hidalgo..................................... ... .. . .. .. 797 

F 16 ........................ Pernnsula of Yucatan...................................... . . . . . . . . . . 797 

F-G 12 ....................... Lower Cahforn1a............. ........... ..... ....... .. .... .... .. ... 799 

G 14 .................... Tamauhpas .. .. .. . .. .. .. .. .. .. .. . .. .. .. . .. . .. .. . .. .. .. .. . . .. .. .. .. . 799 

H-I 11 .................... Tia Juana, Lower Cahforma.................... .. .. .. .. .. . .. .. .. .. . 799 

E 18...... . .. ............. Jamaica....... .. .. .. .. . .. . .. .. .. .. .. .. .. . .. .. . .. .. .. . .. .. .. .. . .. .. . 799 

E 19 ........................... Santo Dommgo and Porto RICo............................. . .. .. .. .. . 801 

F 17-18..................... . . .. Cuba................................................................ 803 

G-H 14, H-I 15 ................. Texas, Lomsmna, and Arkansas........................................ 804 

G 17, H 16-17, I 15-17, J 16 ....... SouthAtlantlc and eastern Gulf Coastal Plam and north end of Mississippi 

embayment........................................................ 806 

H-J 13-14 ..... _ . . . . . ......... Great Plam~, Colorado, Kansa", Oklahoma, New MexiCo, and Texa~ .. . .. . 813 

I 10-lL..... . . .. . .. ..... Santa Barbara and southern Cahforma.. ..................... .. ........ 814 

I-J 10-11 ........................ Coast Range, Cahforma.. ... .... . . .. .. .. .. .. .. .. .... . . .. .. . . . . .. . .. .. 815 

J-K 11.... _ .. . . .... Nevada, Oregon, and Idaho............. . . .. ... ..... .. . .. ....... ... 819 

K 10.... . ... .. ............. Northern C'ahfornia......... ......................... ... ... ...... .... 820 

K 11-12 ........................... Nevada, Utah, and Idaho (See also K-L 11 ).. .. . .. .. .. .. .. .. . .. .. .. . . 820 

K 13-14 .......................... Northern Great Plams, Wyoming, Nebraska, and South Dakota.......... 821 

K 18 ............................ Long Island (not mapped).................................. . . . . .. . . . . 823 

794 
FiGURE 19.-Sketch map showing the distribution of later Tertiary rocks represented on the geologic map of North 

America and the key to references in the text. Miocene and Pliocene mapped separately where their extent is 

known. 

795 
796 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

K 19 .............................. Marthas Vineyard and Nantucket (not mapped)......................... 823 

K-L ll ............................ Snake ~iver basin, Oregon and Idaho.................................. 824 

L 10 ............................... Coast Range of Oregon; Cascade Range and Yakima Valley, Washington.. 825 

L 10-11. ........................... John Day Basin, Oregon, and Columbia Plateau......................... 826 

L 12 ............................... IV estern Montana..................................................... 831 

L-M 10 ............................ Olympic Peninsula, Washington....................................... 832 

L-M ll-12 ......................... Lake basins of western Montana........................................ 833 

M 12-13 ........................... Cypress Hills, southwestern Saskatchewan.............................. 834 

N 8-9 .............................. Graham Island, Queen Charlotte group (mapped as earlier Tertiary)...... 834 

N 10 ............................... Upper Peace and Fraser rivers, British Columbia........................ 835 

N-0 4 ............................. Alaska Peninsula (not mapped)........................................ 835 

0 4 ............................... Bristol Bay........................................................... 835 

0-P 9 ............................. Dease and upper Liard river8, British Colmnbia......................... 836 

P 6-7 .............................• Controller Bay region, A,aska. (See Chapter XVI, pp. 788-789.) 

Q 5-6 ............................. Yukon Valley (not mapped)........................................... 836 

Q 7 ..............................• Upper Yukon (not mapped)........................................... 836 

Q 8 ............................... Peel River (not mapped).............................................. 837 

Q 9-10 ............................ Mackenzie Valley and Bear River (not mapped)......................... 837 

R 5-6 .............................. Arctic coastal plain, Alaska............................................ 838 

R-U 16-22 ........................ Arctic Archipelago and western Greenland.............................. 838 

B-C 18. COLOMBIA. 

Karsten 473 describes certain strata of Cretaceous age as occurring in the Cordillera of Colombia (see Chapter XIV, pp. 581-582) and states that they are covered 

unconformably by a micaceous white or yellow sandstone, of more or less coarse 

grain, succeeded by quartzose ( ?) and variegated marls and by clay shales, which 

include beds of lignite that alternate with the shales in thin layers and in beds up 

to 3 meters in thickness. The latter group, which is distinguished by paucity of 

fossils, is not very thick in the higher regions, but it becomes thicker and more 

important in the lower regions and in the valleys of Magdalena, Cauca, and Patia 

it constitutes the surface to the exclusion of almost everything else. 

According to the region it is sometimes represented chiefly by conglomerates, or again by 

sands and clays; the latter, which are for the most part variegated in color and micaceous, 

often contain pebbles and pass into pucldingstones. The conglomerates are formed of pebbles, 

of the size of a fist or smaller, of a siliceous schist or of a quartzite which belongs to the rocks 

which contain Foraminifera and which are united by siliceous cement. In some districts of 

Magdalena this complex overlies the reddish-brown sanely marls which have been described 

above and which contain flakes of mica; the latter should be studied in order to ascertain 

whether it belongs to the Cretaceous or itself constitutes the lowest member of the Tertiary 

series. The latter hypothesis appears to me most probable because the Tertiary conglomerates 

rest directly upon this dense marl; the Cretaceous marls do not contain any mica. They are 

firmer and more distinctly stratified and in their upper portion inclose thin layers of limestone. 

Karsten mentions the occurrence of petroleum in these strata, and continues: 

Limestones are rare in this Tertiary series. On the Upper Magdalena I have never observed 

any fossils. At Popayan I found a thin bed of argillaceous shale and limestone resting upon 

porphyry and containing shells of Tertiary mollusks (gastropods, Cardium, and Rostellaria 

guadichaudi D'Orb.) very like those of the present. * * * 

With regard to the gigantic bones of extinct mammals, I may say that I saw them in 

Colombia,constantly in a red sandy marl which lies upon the Tertiary. In Ecuador one finds 

them not only in the lower places but also upon the plateau and on the slopes of trachytic 

volcanic cones, where they lie in part in a volcanic tuff that is to the general view very like 

this marl. These remains are very widely distributed in the country. 

Karsten gives numerous localities at which he observed the remams of fossil 

bones. 
LATER TERTIARY (MIOCENE AND PLIOCENE). 797 

E 14-15, F 14 AND 16, G 12 AND 14, AND H-I 11. MEXICO. 

Several localities at which the Miocene or Pliocene have been identified in 

Mexico are mentioned by Aguilera/e and are here referred to under the index 

headings enumerated above. A general account of the Tertiary of Mexico is given 

by Felix and Lenk. 327 The local occurrences are the same as those given by Aguilera, 

but it is profitable to refer to their lucid and connected description. 

E 14. OAXACA. 

The Pliocene of Paso Real, at Tuxtepec, in Oaxaca,9r includes conglomerates of 

old crystalline rocks which overlie sands and white sandstones and contain Pecten 

(Euvola) bowdmensis Dall, Lmvicardium sublineatum Conrad, Calliostoma cf. linuum 

Dall, Anguinella virginica Conrad, Xenophora cf. conchyliophora Born, Natica canrena L., Natica (Polynices) perspectiva Rogers, Strombus pugilis L., Sconsia sublmvigata Guppy, Pyrula papyratia Say, Melongena (Solenistra) mengeana Dall, 

111arginella wilcoxiana Dall, Marginella cinerarea Dall, Oliva cf. litterata Lamarck, 

Pleuritoma (Drillia) alesidota Dall, Conus cf. verrucosus Bruguiere. 

E 15. CHIAP AS. 

In Chiapas,9e in the vicinity of Simojovel, the Miocene is composed of dark 

argillaceous shales, blue clays, brown sandstones, and interbedded limestone of a 

white color, which assumes a reddish tint and which extends to the north in the 

plateau of central Chiapas. The following fossils have been found: Pecten, Ostrea, 

Turritella, Conus planiceps Heilprin, Clypeaster cf. meridamensis Michelin, etc. 

In the vicinity of Coatzacoalcos, upon the river of the same name, there are 

white and brown sandstones which contain Amusium papyraceum Gabb, Anomia 

simplex D'Orbigny, and Lmvicardium sublineatum Conrad, of the Pliocene. 

In the vicinity of Tenejapa, Chiapas, occur marine Pliocene rocks consisting of 

micaceous sandstones and argillaceous shales, together with andesitic tuffs, conglomerates, and marls which contain Ostrea. This terrane occurs also in the valley 

of the Rio Chiapas beyond the boundaries of the State of Chiapas. It is found in the 

hills of Tabasco, near Macuspana, with Natica canrena; on the frontier between 

Tabasco and Vera Cruz, near Tenosique; and in the peninsula of Yucatan with 

Ostrea virginica, Pecten gibbus, Pyrula papyracea, etc. 

F 14. VERA CRUZ AND HIDALGO. 

In the States of Vera Cruz and Hidalgo 96 lacustrine deposits of Miocene age 

occur in the vicinity of Zacualtipan and at Tehuichila. They consist of argillaceous 

shales with beds of lignite and contain Hippotherium (Hipparion peninsulatum 

Cope), H. rectidens Cope, and Protohippus castilloi Cope. 

The marine Pliocene is recognized by its fossils at Santa Maria Tatetla, at 

Papantla, and at Tuxpan, in Vera Cruz. 

F 16. PENINSULA OF YUCATAN. 

The northern portion of Yucatan is occupied by Pliocene and possibly in places 

by post-Pliocene limestone, which forms a broad plain that rises gradually south-
798 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

ward to the hills of the Sierra de Yucatan. Heilprin 433 describes the plain and 

says: 

The rock formation over the greater part of the plains is that of a gray or white shell limestone, highly indurated or subcrystalline in local areas, but rarely to the extent of obliterating 

its fossiliferous character. Secondary depositions of calcite, in the form of veins, crystals, and 

nodular masses, are abundant. Where less compact the rock may be said to be a mass of loosely 

united shells, a condition that is best shown in the superficial layers. Good sections of the rock 

are seen only in the walls of the aguadas and cenotes and in a number of railway cuts which 

traverse it both in a north-south and east-west line; the rock surface is, however, visible over a 

very large part of its extent, being but scantily covered with soil and supporting only an indifferent vegetation. Its decomposition has liberated large quantities of red earth, similar to that 

which is found in our own northern region (terra rossa) and on coral islands (for example, the 

Bermudas, Bahamas), and which is seemingly a residual product representing impurities of one 

form or another which were introduced into the limestone at the time of its formation. * * * 

The paleontological evidence of the fossils contained in the limestone is to the effect that 

the latter belongs to two periods of geological time, the Pliocene and the post-Pliocene, but 

stratigraphically it is not easy to draw a line of demarcation between the two formations. It, 

indeed, appears as though the post-Pliocene, except in the coastal area, were present only in 

patches, having been removed through atmospheric decay and denudation. It is in most places 

easily distinguished by the large numbers of Venus cancellata which fill the rock, making a 

true Venus cancellata bed, such as I observed capping the Pliocene beds en the Caloosahatchie, 

Florida, just below Fort Thompson. The beds occupy similar positions and hold equivalent 

relations to the construction of the land and may, therefore, be considered as counterparts of an 

identical formation. 

For lists of living and extinct species, see the work cited. Heilprin continues: 

The exact position in the Pliocene series which these Yucatan rocks hold can not, perhaps, 

be stated, but they with little doubt correspond at least in part with the series occurring in 

Florida which I have designated the "Floridian." It is true that the number of extinct species 

of the mollusks is seemingly less in the Yucatan rock than in that of Florida, but it should be 

said that in addition to the forms above enumerated, there are a considerable number, occurring 

mainly in the condition of unrecognizable casts, which may largely represent extinct species. 

Dall and Vaughan agree with Ileilprin on the Pliocene age of the fossils cited 

by him. Sapper 694b says: 

The Tertiary beds are in general but slightly inclined. In the vicinity of Istapa, of San 

Antonio, Tenejapa, and Tumbala there are horizontal beds. They are more modern than the 

andesitic eruptions, for they include the andesites in the conglomerates and the horizontal 

strata even rest directly upon the andesite. 

In the peninsula of Yucatan the Tertiary terranes predominate and it would seem that from 

south to north there is a sequence of more recent beds until one reaches the post-Pliocene 

(Quaternary) deposits of the northern coast. 

The southern region of Yucatan is composed of calcareous formations which in many places 

abound in cherts. Between the beds of limestone there are also some beds of marl and others 

of alabaster, and in the marls there may be found in the Cerro de Ixconconcal, near Icaiche, 

certain fossils which may serve to determine the relative age of the deposits. 

These fossils are apparently not cited, but the beds are supposed to be those 

which are mapped by Sapper as limestones with marl and alabaster and are regarded 

by Dallas Oligocene. All the other formations distinguished by Sapper, comprising 

the white and red limestones, as well as his Pliocene, are here placed in the Pliocene. 
LATER TERTIARY (MIOCENE AND PLIOOENE). 799 

F-G 12. LOWER CALIFORNIA. 

At Santa Rosalia and Boleo, Lower California, 9

d there are deposits of upper Miocene age which probably correspond to the beds of Carrizo Creek, California, and 

which are characterized by Pecten (Plagioctenium) cedroscensis Gabb, Pecten (Pecten) 

carrizoensis Arnold, P. (P.) keepi Arnold, Semele aff. pulchra Sowerby, and Malea 

aff. ring ens Swainson. 

For a general statement of the geology of Lower California and sources of 

information, see Chapter XV (pp. 644-647). , 

G 14. TAMAULIPAS. 

In the valley of the Rio Bravo, near Matamoros, Tamaulipas, the marine 

terrane of the late Tertiary is well represented, and according to Aguilera od it is 

possible to recognize several of Dumble's subdivisions of the later Tertiary of Texas, 

namely, Oakville, Lapara, and Lagarto. 

H-1 11. TIA JUANA, LOWER CALIFORNIA. 

At Tia Juana, Lower California,9

d there ocG:urs a formation equivalent to the 

.Purisima formation of California, which belongs at the base of the Pliocene. In the 

island of Cedros this formation is present but not mapped and is characterized 

by Pecten(Nodipecten) veatchi Gabb, Pecten lecontei Arnold, and Pecten (Plagioctenium) 

cedroscensis Gabb. 

E 18. JAMAICA. 

The classification of the geologic formations of Jamaica is given in Chapter XV 

(p. 640), and the older formations are discussed in Chapters XV and XVI (pp. 639-

642, 717-721). 

According to Hill 443 the later Tertiary is separated from the early by a hiatus 

corresponding to the middle Oligocene. The formations representing the late 

Oligocene or Miocene and the Pliocene are classified as the Bowden, May Pen, 

Kingston, and Manchioneal formations, in ascending order. 

Under the heading "Bowden and allied formations" (the Yellow limestone 

.Df some previous authors), Hill 443g says: 

This series includes a class of formations which represent the products of events more 

recent in the history of the Jamaican sequence than those hitherto enum!'lrated. Its members 

occur around the coastal perimeter of the island, principally along the margins of the sea at 

·altitudes nowhere exceeding 250 feet, and deposited unconformably against the sides of an older 

-'mainland. Here and there on the south coast they fill previously formed erosion plains. They 

-were all made during epochs subsequent to an epoch of elevation whereby the white limestones 

of the Oceanic series and all preceding formations had been elevated into land, had undergone 

tremendous denudation, and had again suffered partial marginal subsidence. 

They are of four types of formations, to wit, beds of impure marine limestone, gravel, and 

marl; alluvium of the Kingston type; elevated coral reefs as illustrated in the Barbican and 

Hopewell formations; and littoral deposits of calcareous mud, with embedded fossils of contemporaneous origin with the elevated reef formation. The four types in their general lithologic 

characters are analogous to the marine, littoral, alluvial, and coral-reef formations now being 

made around the margins of Jamaica. 

The Bowden and allied formations of later Tertiary age constitute the older beds of the 

Coastal series and are all marginal to the main upland mass of the island. They apparently 
800 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

represent a series of fringing formations extending around the olaer plateau region. These in 

turn are bordered by still later and lower-lying formations. 

Along the south coast of the east end of the island, between Morant Bay and Port Morant, 

there is an extensive occurrence of gravel beds less than 50 feet in thickness, containing rolled 

specimens of nearly every species of volcanic rock found in the island, which grades upward into 

an impure stratified brown and buff colored marl, the latter having a thickness of 200 feet 

as measured in the bluff upon which Capt. Baker's house at Port Morant stands. The loose 

gravels at the base of this section have a very recent appearance, a deception which is further 

aided by the fact that they occur at beach level and contain perfectly preserved fossils resembling 

modern shells. The fossils heretofore reported from Bowden are found in the gravel bed and, 

less abundantly, in a few feet of the lower part of the overlying marls, at the foot of the hill, 

at the beginning of the road leading up the hill to Capt. Baker's, and in such abundance that as 

many as 400 species of mollusks have been determined by Dr. Dall from two barrels of material 

collected by Messrs. J. B. Henderson, jr., and C. T. Simpson, and the writer. A few specimens 

occur higher up the hill, while near the summit there is a body of firm crystalline secondary 

limestone containing molds of the characteristic fauna. The physical characters of this formation can be traced from Bowden to Morant Bay and beyond nearly to Yallahs Island, but 

there it loses its identity. On the road from Bath to Bowden its position above the Cambridge 

beds is fairly well revealed. 

The stratigraphy of the formation has not hitherto been presented correctly, although in the 

Jamaican reports under the name of the "Yellow limestone" it was partially confused with the 

entirely different beds herein described as the Cambridge formation, and the gravel beds were 

mapped with the Pleistocene and Recent formations. Hence its identity as a formation did 

not appear in these reports. 

It is only on the south coast of the east end of the island that the Bowden beds have the 

characters mentioned. It is evident that the formation with modified lithologic features 

occurs elsewhere on the island, for the Bowden fossils have been found on the opposite side 

by us and reported from round the district of V ere, near the coast of Clarendon, by other writers, 

in formations of quite a modified lithologic nature. Probably the Buff Bay, May Pen, and 

Porus formations, next to be described, are allied and synchronous deposits. 

For details of the several related formations named, see the report cited. 

The :Manchioneal formation is of marine origin and is composed of alternating 

layers of loose yellow marl and lumpy white limestone with well-defined bedding 

planes, and locally of alternating evenly bedded marl and impure limestones. 

Hill describes exposures that exhibit from 100 to 200 feet of deposits of this character. Fossils are not numerous and the occurrences appear to be of small area. 

Hi11443h says: 

From the low position of the Manchioneal formation adjacent to the coast and unconformably against the older and more disturbed white limestones, it is evident that it was a 

marginal fringing deposit. Its stratigraphic position above the Bowden formation and below 

the undoubted elevated reef rock, as well as the paleontologic evidence of its pteropods and 

Brachiopoda, indicates the Pliocene age of this formation. The contained corals, here poorly 

developed but occurring in increased proportions in the succeeding beds, mark the first definite 

appearance of the marine reef-building species in the Jamaican sequence. 

The Kingston formation is described as consisting mainly if not entirely of 

material derived from adjacent uplands of the mountains and plateau. It varies in 

composition, being mostly detritus of the Blue Mountain series to the east of the Rio 

Cobre and largely white limestone debris .to the west of that stream. It has been 
LATER TERTIARY (MIOCENE AND PLIOCENE). 801 

successively accumulated through several geologic epochs and may ultimately be 

classified into several distinct terranes. Hill 4431 says: 

For the present, however, we shall recognize but two principal stages-an older one, to which 

the name of Kingston will be applied, and a newer one, which will be called the Montego. 

The Kingston formation is the oldest of the formations of old gravel and other alluvium 

occurring upon the plains of the Liguanea type. This is the formation upon which the city of 

Kingston and suburbs are built, including the strip of land known as the Palisades, and the 

plain extending back of Kingston to the foot of the mountains. * * * The material consists of bowlders, gravel, and pebble of varying sizes, usually very angular, and representing 

every known material of the Blue Mountain series. These are embedded in a matrix of dull 

red arenaceous clay, producing a chocolate soil and derived from the Minho beds so conspicuously exposed in situ in the mountains north of Kingston. 

The thickness of this formation is unknown, but over 200 feet are exposed in the thalweg 

of Hope River, and probably fully this thickness is concealed. It is even likely that it may be 

nearly a thousand feet in places. * * * 

As a whole, it represents excessive deposition, first as estuarine or littoral material during 

an epoch when the coasts were submerged, and later talus deposits of subsequent epochs, when 

the land was rapidly rising and stream erosion was very active, as discussed more fully in another 

part of this paper. The alluvial deposits in the bottom of the larger interior basins are also 

closely synchronous with the Kingston formation, and it is probable that these basins are 

products of the same great erosion epoch which preceded the Kingston deposition. 

Fossils are generally missing from the Kingston formation; speculation concerning its age 

must be founded entirely upon stratigraphical relations. In our opinion it is clearly older 

than the elevated reefs of the Barbican and Hopewell formations, of presumable Pleistocene 

age, and younger than the Bowden formation, being nearly allied by position to the age of the 

Manchioneal, which we consider Pliocene. 

The present beds of both the Hope and the Cobre rivers deeply indent the Kingston formation, cutting far below the surface of the plain. The alluvium of these stream valleys and 

their general level constitute distinct deposits which are later described under the head of the 

Montego formation. 

In his further description Hill gives many details regarding the elevated reefs 

and miscellaneous coastal formations contemporaneous with them. 

E 19. SANTO DOMINGO AND PORTO RICO. 

Gabb 252b placed the Tertiary of northern Santo Domingo in the Miocene and 

probably that of Porto Rico as of the same age. Regarding Santo Domingo Gabb 

says: 

All of that part of the island which lies north of the Cibao Mountains, except a part of the 

peninsula of Samana, is made up of Tertiary rocks, usually bordered by a narrow strip of more 

modern age. They also form one or two insignificant deposits on the south side about San 

Cristobal and the Nizao, and are said further to cover a part or all of the valley of the lakes 

running to Port au Prince in Haiti. The work of the geological survey not having extended to 

the latter region I shall confine my observations to the others. 

The district covered by this formation in the north, including its extension into Haiti, 

toward Cape Haitien on the west, and into Samana and south of the bay east, is little less than 

150 miles long, although, cutting off these prolongations, it forms a compact area of about 100 

miles long by 30 miles wide, or say, in round numbers, about 3,000 square miles. It abuts 

against and even overlaps the lower foothills of the central chain, underlies the whole valley 

of the Yaqui and Yuna, makes up the entire northern or Monte Cristi Range, and sends others 

48011°--12----51 
802 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

along both sides of Samana Bay. In the south it forms a little group of hills extending from 

near the Jaina River across the Nigua and thins out in a few isolated patches toward the Nizao. 

Its total thickness in the vicinity of the Nigua River is about 400 feet, and it is made up of a 

succession of brown earthy and sandy beds, occasionally calcareous, superposed on a thin stratum 

of conglomerate. The top of the series is a rather compact calcareous deposit containing 

corals. The fossils, except the corals, are usually badly preserved and very meager in species; 

a small oyster, two species of Pecten, and some echinoderms being the only recognizable forms. 

Besides these, a few internal casts of gastropod shells have been discovered. The corals are so 

embedded in their matrix that they can only be collected satisfactorily when they are weathered 

out, and this same process of weathering is only too apt to destroy the delicate structure of 

their surfaces. They are, however, nearly all of the massive forms and are so thoroughly 

fossilized as to be well adapted for polishing. 

But while the formation is so small in aTea and so unsatisfactory in general characters on 

the Santo Domingo side, it becomes, in the Cibao, the most interesting on the island. Cut 

through by all the tributaries of the Yaqui the sections are numerous and excellent for study. 

Its local modifications are well illustrated by sections innumerable, into and across the Monte 

Cristi Range on one side and into the southern hills on the other. In short, it would be difficult 

to find a region where the facilities furnished to the geologist are greater, or where the results 

could be more certainly arrived at. Add to this that a larger part of the formation is highly 

fossiliferous, and that the fossils, whether shells or corals, are almost always preserved entire 

and hard; as beautiful as the famous fossils of the Paris basin, or as the less known though 

equally beautiful specimens from Jackson, Miss. 

The entire thickness of the formation in the Cibao is probably over 1,500 and under 2,000 

feet. It is made up of coarse sandstones at the base, sometimes bearing beds of conglomerate, 

which are, however, rather local in extent. These beds are best developed between the Bao 

and the Yaqui, where, being uptilted, their thickness is best seen, and are about 600 feet thick. 

They gradually merge into gray shales, which form a transition to the heavy blue-sh&le beds 

underlying the town of Santiago and called by the English paleontologists the Nivaje shale. 

The upper part of this member is always of a light yellowish brown or buff color and sometimes, especially at its upper part, contains beds of sandstone. The whole of this shale member may be safely estimated at about 800 feet of average thickness. The remainder of the 

formation, say 400 feet more in all, varies locally. It caps the greater part of the Monte Cristi 

Range, and while north of Moca it forms high bluffs of a nearly white earthy rock, in which it is 

doubtful whether the argillaceous or the calcareous ingredients preponderate, it forms north 

of Esperanza sheets of a compact limestone, which, less pure, forms the cap on the isolated 

table mountain of Monte Cristi. Near Cevico it appears as an impure lime rock containing 

corals and Foraminifera, and similar beds occur also on Samana and south of Savana la Mar; 

while the caves of San Lorenzo, in the same beds, are in a hard, coarse-grained calcareous sandstone. Nor do the variations cease here. Near the mouths of the ancient Miocene rivers running from the then much smaller islands now constituting the Cibao Mountains, and among 

which the Mao was probably the largest, the gravel debris of these streams was deposited, 

occasionally alternating with a bed of coarse sandstone, synchronously with the formation 

of the coral reefs and beds of fine white mud which now glistens in the sun on the top of the 

Monte Cristi Range. We have thus an ideal section as follows: 

Feet. 

White calcareous marl, north of Moca; white or light-brown limestone ("Tufaceous limestone'' 

of Heneken); light-brown calc sandstone, San Lorenzo Bay; gravels of Mao and Savaneta; limestones of Samana, San le Mar, Cevico, and the north face of the Samba Hills; oyster beds of 

Samba Hills, south of Guayubiu.... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400 

Brownish or yellowish shale of Guayubin; conglomerate of Angostura of the Yaqui; sandstone 

strata near Santiago: dark-blue shale of Santi-ago; gray shale with beds of sandstone of Rio 

Verde and in the hills north of Moca ................................................... -- .. 800 

Coarse gray sandstone with some conglomerate; seen best in the hills south and southeast of Santiago, also in a rew places in the north range ................ -............................ -.. GOO 
LATER TERTIARY (MIOCENE AND PLIOCENE). 803 

These three members are so intimately united that their separation is purely arbitrary. 

Beds of sandstone are found in the shale, and beds of shale extend far down into the lower 

member. Very few if any fossils have been found in the sandstone, though the gravels of 

Angostura yield shells abundantly, in connection with fragments of fossilized wood. The 

same species of fossils occur in all parts of the series, and I have collected from a bed of sandstone at the very summit of the Mao gravel a series of shells identical with those embedded in 

the rocks of the "nonfossiliferous sandstone" plain east of Guayubin, and which are found 

abundantly in the blue shale of the Gurabo, Amina, or Verde. 

Fossils are not regularly distributed either vertically or laterally, but seem to occur in 

colonies. The blue-shale bluff under the city of Santiago, 60 feet high from the level of the 

river, does not show a single streak where they are ever abundant enough to repay the trouble 

of hunting, although isolated shells occur throughout. At Puiial, but a few miles off, near the 

Rio Verde, shells and corals abound. The same irregularity exists throughout, and although 

there is but little change in the species of the Mollusca in their vertical range, there is a marked 

difference between the eastern and western ends of the basin. Shells that are absent or scarce 

on the Verde are common on the Gurato and westward, and vice versa. The corals found in 

the shale are almost always of the cup forms, while the massive corals are almost exclusively 

confined to the upper beds and are particularly abundant on the north flanks of the Samba 

Hills. In all the shale beds and to the extreme top of the series Foraminifera occur and in some 

places are found in great numbers. They are not very numerous in species, probably not 

exceeding half a dozen. The Orbitoides ranges throughout all the strata and is not only found 

wherever any other fossil occurs but is often, especially in the higher beds, the only recognizable organic remains. It has more than once proved of great value to me in distinguishing these 

limestones from the overlying post-Pliocene calcareous beds. 

With one or two small exceptions all these rocks are entirely unaltered. On the southern 

limit, in contact or nearly so with the underlying Cretaceous in the vicinity of the Bao River 

and on the Yaqui, the coarse sandstones are slightly modified, though still retaining their stratification and mechanical structure unchanged. On the Yaqui at Tabera this rock is highly 

uptilted and slightly contorted, as will be seen by reference to the description of the locality. 

Also in the northern range a similar slight metamorphism occurs southeast of Puerto Plata. 

Gabb then discusses the geologic age of the West Indian Tertiary rocks and 

gives the age of many fossils, including 217 supposed extinct species and 97 known 

to be living. He concludes, "We are therefore at or near the top of the Miocene." ~ ~ 

F 17-18. CUBA. 

T. vV. Vaughan has contributed to this work the following notes on the later 

Tertiary of Cuba: 

An extremely interesting fact in the Cuban stratigraphy is that, so far as we at present 

know, there is absolutely no true Miocene on the island. The Miocene as described by De Castro, 

Salterain, and others is now referred to the upper Oligocene. From the evidence now before 

us, it seems most probable that during Miocene time none of the now existing portions of the 

Island of Cuba were submerged beneath the ocean. 

The data regarding the presence of Pliocene strata are unsatisfactory. The only data on 

which we could base a conclusion are derived from the notes and collections of William Palmer. 

In the western part of Havana, on the Calle Infanta, opposite Castillo de la Punta, Palmer 

collected fossils from a quarry in soft white limestone. The bottom of the quarry is about at 

sea level. According to Palmer the same formation extends to approximately 60 feet above. 

sea level. The fossils obtained from this locality may be Pliocene, though it is probable that 

they are Pleistocene. The limestone which is being quarried between Almandares River and 

Camp Columbia, on the north side of the road, may be of Pliocene age. 
804 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Surrounding the greater portion of Cuba, but especially along the northern coast and 

bordering the southern coast of Oriente from Cape Maisi to Cape Cruz, is a low coastal shelf 

nowhere exceeding a maximum elevation of 30 or 40 feet. There is beneath this shelf in places 

a lower terrace some 5 or 6 feet above the water's edge. Both of these terraces are composed 

of elevated coral-reef rock. The material is a limestone presenting an extremely rough upper 

surface and replete with the remains of numerous species of corals which are all, so far as examined, at present living in the surrounding Antillean seas. These reefs have been formed and 

elevated within very late geologic time. 

A coating of surface gravel exists over the plain in the Province of Pinar del Rio on the south 

side of the Sierra de los Organos. The material has been derived from the rocks constituting the 

mountains and has been distributed through the agencies of streams and floods. It is probably 

of Pleistocene age. 

G--H 14, H-I 15. TEXAS, LOUISIANA, AND ARKANSAS. 

The following discussion has been compiled by T. W. Vaughan from the literature and from manuscripts of A. F. Crider and Alexander Deussen. Most of the 

literature is cited in Chapter XVI (p. 723); other references are given in the discussion. 

MIOCENE. 

No surface outcrops of marine Miocene deposits between Mississippi River and the Rio 

Grande have yet been described. Buried marine .l\fiocene beds occur in southern Louisiana 

and in the coastal region of Texas. The two most thoroughly studied occurrences are those 

of the Jennings oil well, Louisiana, and the deep well at Galveston, Tex. 

In the Jennings area the equivalent of the Pascagoula formation of Mississippi was penetrated at depths ranging from 1,040 to 2,183 feet, the variation being due to folding. 407a In the 

Crowley field the" Rangia johnsoni" zone is from 1,960 to 2,600 feet below the surface.407b 

Harris 402 has described a large Miocene fauna encountered in the Galveston deep well 

between 2,158 and 2,920 feet below the surface. 

Deussen has discovered in De Witt County, Tex., littoral or fresh-water beds in which the 

remains of .1\fiocene vertebrates were found. The material consists of cross-bedded coarse gray 

semi-indurated sands, gray sandstones, and local lenses of clay. The beds grade seaward into a 

marine phase and are overlain by Pleistocene deposits. Deussen thinks that these beds may-be 

a littoral phase of the marine .1\fiocene encountered in the Galveston well. 

Dumble 2970 has proposed the name Oakville for "grits and coarse sands, cross-bedded, with 

some beds of clay, but oftener with balls, nodules, or lenses of clay embedded in the grit. Some 

of the sands form a sandrock which is apparently firm and hard, but much of it is so feebly 

coherent as to fall apart on a slight blow of the hammer. Local beds of conglomerate occur." 

A few fossil vertebrates were obtained, but they were considered sufficient to determine the age 

of the formation as "Loup Fork." The formation in which Deussen found Miocene vertebrates 

in De Witt County may belong to Dumble's Oakville. 

Above Dumble's Oakville are formations named by him Lapara and Lagarto, 297d but they 

have not been correlated with the geologic time scale. 

PLIOCENE. 

No marine Pliocene deposits are knowri to outcrop between .1\fississippi River and the 

Rio Grande, but a recent discovery of G. C. Matson in Louisiana, 8 miles west of south of Alexandria, indicates that such deposits may have a considerable development in south-central 

Louisiana and may even extend into Texas. 

The problematic Lafayette formation covers extensive areas in northeastern Arkansas, 

southern Arkansas, northern and central Louisiana (especially over the Catahoula and Fleming 

formations), and eastern Texas. 
LATER TERTIARY (MIOCENE AND PLIOCENE). 805 

The following description for northeastern Arkansas is taken from a manuscript by Crider: 

"Overlying the Tertiary in Crowleys Ridge and also on the western border, and extending 

for a short distance over the Paleozoic rocks, there is a thin blanket of sand and gravel of the 

Lafayette with a maximum thickness of about 30 feet. The Lafayette has been removed from 

the lowland regions east and west of Crowleys Ridge, along with the Tertiary. 

"Where the loess is absent, as in many places on Crowleys Ridge north of Jonesboro, the 

Lafayette is present on the highest divide. South of Jonesboro it appears beneath the loess in 

the railway cuts and deep ravines which have been cut to the middle portion of the ridge. Nearly 

all the principal streams of Crowleys Ridge have cut through the loess and Lafayette, and their 

materials have been carried down and spread out on the slopes and the adjacent bottoms. It is 

probable that most of the Lafayette which was originally deposited on the eastern foothills of 

the Paleozoic rocks from Missouri to Pulaski County, Ark., has been :reworked by the streams 

and carried farther down the slopes. 

"Where undisturbed the Lafayette is made up of chert, quartzite, and white and black 

quartz pebbles indiscriminately mixed with a coarse, well-rounded reddish sand. The whole is 

roughly stratified, showing the effects of ever varying currents. At the base of the formation 

the pebbles are, in places, interbedded with materials reworked from the underlying formation. 

The cherts constitute a large proportion of the pebbles in the formation. They are much 

larger and more angular than the quartz pebbles, and many of them contain fossil crinoid stems. 

They are, therefore, evidently derived from the cherty limestones of the adjacent Paleozoic 

hills. The quartz pebbles are much smaller than the cherts, and are well rounded and polished. 

"Sand everywhere accompanies the gravels and in places forms the bulk of the formation. 

The grains are well rounded and, like the pebbles, are almost universally stained with oxide of 

iron. It is probable that some of the sand has been derived from the underlying formations, 

but a current that would be strong enough to bring in a large amount of foreign gravel would 

also carry a still larger amount of sand. Much of the sand, therefore, doubtless has the same 

origin as the pebbles. 

"The Lafayette contains a large amount of ferruginous matter. Under favorable circumstances the iron oxide has cemented the sand into a rough, hard brick-red sandstone and the 

gravels into an ironstone conglomerate which is in few places more than 5 feet thick. These 

hard ferruginous masses are prone to form where the percolating waters, carrying the iron oxide 

in solution, come into contact with a compact clay or any other impervious layer. Subsequent 

erosion exposes these cemented masses, which in places protect the hills from further erosion, 

while large blocks break loose from the main ledge and cover the slopes." 

This description applies well enough to the other areas in Arkansas and Louisiana. 

According to Deussen (unpublished manuscript), "A wide area of the Coastal Plain in 

Texas east of Brazos River is occupied by a series of clays, sands, and gravels,, which overlap 

the Miocene beds and in many places overlie and obscure the Fleming clay and are seen to rest 

directly on the Catahoula formation. Originally these beds mantled the older rocks over this 

entire area and the adjacent Black Prairie and extended in broad tongues up the valleys in the 

region to the west. These exposed portions have been subjected to erosion for so long a time 

that the interior margin, once very far to the west, has been gradually transferred seaward. 

In the area of the former extent many outliers persist on the higher divides and plateaus where 

their isolated position has protected these materials against erosion. These high-level gravels 

are so common within this area that they generally obscure the older underlying formations. 

The latter are exposed only in the channels and valleys cut by the streams since the deposition 

of the Lafayette. 

"Toward the coast these sands, clays, and gravels dip beneath the overlying Pleistocene 

gravels and are recognized in many of the wells put down in this portion of the Coastal Plain. 

"These sands and clays and gravels wherever exposed unconformably overlie the lower 

beds, indicating an erosion epoch between their deposition and that of the underlying beds. 

"As a rule the materials carry no fossils indigenous to the strata. Waterworn fragments 

of fossils from older rocks are sometimes found embedded in the gravels, but these give no 
806 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

important clues to the age of the formation. At Sour Lake, Texas, they lie beneath beds of 

known Pleistocene age and above beds of known Miocene age, a position which would fix their 

age as Pliocene. This is also in accord with evidence from other sources." 

In the region of Austin and San Antonio three distinct terraces flanking the rivers are 

recognizable. The highest and oldest of these occupy the divides, and the material consists 

almost entirely of flint embedded in a calcareous matrix. This is the Uvalde formation of 

Hill 446a and corresponds to the Lafayette of more easterly areas. It consists of the products of 

destruction of the Edwards limestone. This material is now found only in the divides of the 

Coastal Plain, but it constitutes the uppermost terrace in the canyons of the Edwards Plateau. 

The terraces of the second series occupy a lower level and are therefore younger than the 

Uvalde terraces. The materials composing these in the vicinity of Austin consist of granitic 

debris derived from the granites of the Llano region, which was exposed only after the Cretaceous 

cover was removed. In a terrace along Onion Creek, just west of Pilot Knob, Travis County, 

occur vertebrate remains of early Pleistocene age. 446b This would make the upper terraces 

pre-Pleistocene. 

The Uvalde formation is present from Austin to Rio Grande along the interior margin of 

the Rio Grande plain and extends many miles seaward. For further description see Hill 

and Vaughan. 446 

PLEISTOCENE. 

For the areas bordering Mississippi River the brief descriptiOn given on page 813 will 

apply. In southern Louisiana the Port Hudson attains a great thickness-usually over 1,000 

feet and in places over 2,000 feet. This is also true of the Pleistocene of the coastal region of 

Texas. Landward from the border of the coastal prairies of Texas there are two systems of 

terraces between the level of the present flood plains and that of the Uvalde formation. 

G 17, H 16-17, I 15-17 (EAST OF MISSISSIPPI RIVER), AND J 16. SOUTH ATLANTIC AND EASTERN GULF COASTAL PLAIN AND NORTH END OF MISSISSIPPI EMBAYMENT. 

The following discussion (pp. 806-813) has been compiled by T. ,V. Vaughan 

from the literature and from unpublished results of G. C. Matson and E. W. Berry 

in southern Alabama and Mississippi and of his own researches. The principal 

references to the literature have been listed in Chapter XVI (p. 731). To the 

list there given may be added Nos. 566, 653, and 693 of the bibliography on pages 

840-865. 

MIOCENE. 

Vaughan 834 describes the subdivisions of the Miocene along the Georgia-South Carolina 

line, their correlation with formations farther north, and their relation to the upper Oligocene: 

"The following section of the exposure at Porters Landing is adapted from the description 

of it given by Mr. Earle Sloan in his 'Catalogue of the mineral localities of South Carolina,' 

page 273: 

Feet. 

6. Pleistocene-white, red, and yellow sands, with phosphatic pebbles and vertebrate fragments 

at the base.......................................................................... 64 

5. Miocene-compact yellow fossiliferous marl (Duplin horizon)............................. 6 

4. Miocene--grayish fossiliferous marl (Marks Head marl).. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 

3. Fine-grained laminated shale with sandy partings; a line of rounded pebbles at the base... 14 

2. Oligocene-fossiliferous marl (Alum Blufi formation)..................................... ! 

1. Laminated drab shale with arenaceous partings......................................... 8 

Ill! 

"Recent collections made at Porters Landing have rendered possible definite correlation 

of the two Miocene horizons with those of the area farther north. From bed Ko. 5 of the section 

34 identified species were obtained, 30 of which also occur in the Duplin marl of North 
LATER TERTIARY (MIOCENE AND PLIOCENE). 807 

Carolina. The four species which have not as yet been reported from there occur in other 

localities in horizons the stratigraphic equivalent of the Duplin, or in deposits of later age. 

Bed No. 5, therefore, can be definitely correlated with the Duplin marl of North Carolina and 

the fossiliferous Miocene marls of Darlington and Mayesville, S. C. 

"The Marks Head marl, which was first named by Sloan and is represented by bed No.4 

of the section, contains specimens of the genus Carolia, which suggests an Oligocene age, but 

every other identifiable species may be Miocene, and only three of them range downward into 

the Oligocene. Nine of the species are not known below the Miocene, and of these nine, six are 

confined to the Miocene. The horizon is, therefore, Miocene, while the presence of Turritella 

:equistriata Conrad, Calliostoma aphelium Dall, Ostrea mauricensis Gabb, a,nd Pecten marylandicus 

·wagner definitely points to a horizon low in the series, approximately equivalent to the Calvert 

formation of Maryland. 

"The recognition of the stratigraphic position of this horizon is of importance, as it is the 

only low Miocene horizon known south of VIrginia. Farther south in Florida, along the western 

extension, on the Ochlockonee and Apalachicola rivers, the Miocene rests upon the eroded surface of the upper Oligocene. The Miocene deposits of these localities represent a horizon high 

in the series. Therefore, the Marks Head Miocene is the equivalent in part to the erosion 

interval between the upper Oligocene and the Miocene of western Florida. 

"Bed No. 2 of the section at Porters Landing contains fossils indicative of an upper Oligocene age. Bed No. 3 is very likely of Miocene age, and the line of rounded pebbles at the base 

suggests that the Miocene may rest upon the eroded surface of the upper Oligocene. It seems 

probable that along the Savannah River an erosion interval occurred between Oligocene and 

Miocene depositions, but the interval was of shorter duration than in western Florida." 

The Marks Head marl is the oldest Miocene known south of the Hatteras axis. Sloan has 

applied the name Edisto marl to the indurated phosphatized marl in the vicinity of Charleston, 

the source of the rich phosphate deposits of that area. This material overlies the Cooper marl 

(Eocene) and underlies the Pleistocene and is only 2 or 3 feet thick. Although the identifiable 

fossils from it are few, stratigraphic equivalence with the St. Marys formation of Maryland and 

Virginia is definitely suggested. The Edisto marl is overlain by a softer, yellow sandy marl 

near the old Cohen plantation, three-fifths of a mile west of Goodrich station. To this marl 

Sloan has applied the name Goose Creek marl. According to Sloan it is overlain by the Duplin 

marl. The following section at Davis Landing, on Peedee River 16! miles N. 75° E. of Lake 

City, shows the relations of the beds: 

Feet. 

5. Pleistocene Rands and loam................................................................................... 8 

4. Indurated ledge of dirty yellow marl containing Pecten eboreus, especially at the base............. 161 

3. Compact yellow marl with large numbers of Chama striata and Area incile......................... 8 

2. Friable yellow marl, containing Amusium mortoni and Pecten eboreus (Goose Creek marl of 

Sloan)............................................................................................................ 41 

1. Dark blue-green marl, with Cretaceous fossils................................................ 23 

60! 

Beds Nos. 3 and 4 represent the Duplin marl. The faunal aff-inities of the "Goose Creek" 

marl have not yet been positively determined. The Duplin marl is an extension of the marl 

of the same name in North Carolina southward into South Carolina, where it is well developed 

along Peedee River and in the vicinity of Darlington, Mayesville, and Porters Landing, the 

last-mentioned locality being on the Georgia side of Savannah River. 

Otto Veatch, in the manuscript of a report that has been published since this discussion 

was compiled, gives the following account of the Miocene in Georgia: 

''Miocene strata have been discovered in the bluffs of Savannah River in Screven and 

Effingham counties; on Altamaha River near Doctortown, Wayne County; at Brunswick; and 

at Owens Ferry, on Satilla River in Camden County. 

"The Marks Head marl is typically exposed near Porters Landing, on Savannah River, 

Screven County. It has not been differentiated at other localities than the bluffs of this river. 
808 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

This formation rests unconformably upon the Alum Bluff formation and is also separated from 

the overlying Duplin marl by a small unconformity represented by an uneven line of quartz 

pebbles. The strata consist of gray or brownish compact argillaceous sand containing large 

calcareous nodules and, in places, of friable phosphatic sand containing shells. The formation 

does not reach a thickness of more than 30 or 35 feet in natural exposures. 

"The Duplin marl as exposed along Savannah River overlies the .Marks Head marl and is 

separated from it by a small unconformity indicated by quartz pebbles. It is overlain by 

Pliocene (Lafayette?) and Pleistocene deposits of sand and clay. It is a shell marl consisting 

of shells in a matrix of coarse phosphatic sand; in places it consists of a :fine gray or brown quartz 

sand. It probably does not reach a thickness of more than 10 or 12 feet. 

"The Duplin on Altamaha River consists of friable sandy and pebbly shell marl and bluish 

fine-grained argillaceous sand, which is also fossiliferous. The formation unconformably 

overlies strata of probable Alum Bluff age, and is in turn overlain by varicolored sand and clay 

which is probably Lafayette (Altamaha). The Duplin reaches a thickness of not over 12 or 

15 feet. 

"The .Miocene at Brunswick is not exposed naturally and was discovered in dredging operations on Brunswick River. The material thrown off the dredge consists of fragments of bones, 

teeth, sand, quartz pebbles, and compact sandy marl, or shells embedded in a phosphatic sand 

matrix, together with some argillaceous limestone and hard clay. A study of the fossils has been 

made by Vaughan and they were found to range from .Miocene to Recent. 

''.Miocene rock is exposed in the bed and banks of Satilla River at low tide, at Owens Ferry, 

8 miles west of Woodbine. The rock is a brown or grayish compact sand and calcareous 

sandstone, containing poorly preserved fossils." 

The Miocene in Florida rests upon the eroded surface of the upper Oligocene Alum Bluff 

formation, as is shown in the exposures at Jackson Bluff, on Ocklockonee River, and at Alum 

Bluff, on Apalachicola River. The series in thi:s State is divided into two formations that occupy 

different areas but are probably in large part contemporaneous. The formation in the eastern 

area is the Jacksonville, that in the western area the Choctawhatchee. Matson and Clapp 580d 

describe the Jacksonville as follows: 

"From well records and samples obtained along the east coast of Florida, the Jacksonville 

formation appears to rest unconformably upon the eroded surface of the limestones of the Vicksburg group at Jacksonville, St. Augustine, and other localities. Farther westward it probably 

rests on the beds belonging to the Apalachicola group, but no contacts were observed. 

"When fresh, the limestone of the Jacksonville formation varies in color from light gray to 

nearly white, but upon weathering it changes to pale yellow or yellowish gray. It usually has a 

porous texture but occasionally becomes hard and dense. The presence of a large percentage 

of clear quartz sand may be easily distinguished by the use of an ordinary hand lens, and microscopic examination shows that there is also a large amount of clayey material which varies in 

color from light gray to pale yellow. In certain horizons fossils are very abundant, the shells 

having usually been dissolved, leaving nothing but casts or molds; and this fact, together with 

the friable character of the rock, makes it very difficult to obtain satisfactory collections. However, enough material has been obtained to indicate the Miocene age of the rock. Unlike the 

Choctawhatchee marl, the Jacksonville formation appears to contain practically no mica. It 

also differs from the marl in its relatively higher percentage of lime and a correspondingly lower 

percentage of sand. 

''Although the Jacksonville formation is fossiliferous, the organic remains are less numerous 

and in a much poorer state of preservation than in the Choctawhatchee marl. An examination 

of well samples shows that limestone forms only a minor part of the formation, a fact which is 

well illustrated by the log of the well at Jacksonville, where the formation attains a thickness of 

about 500 feet and is composed largely of arenaceous and siliceous beds. From samples obtained 

in drilling a well at Jacksonville the clays are known to be siliceous and the hard materials described 

as gravel found to be chert nodules. Some of the beds consist of a hard gray siliceous rock which 
LATER TERTIARY (MIOCENE AND PLIOCENE). 809 

appears to have been formed by the replacement of the calcareous portion of a sandy limestone 

by silica which was probably derived from organic remains such as sponge spicules and diatoms. 

''The exposures of the limestone of the Jacksonville formation seldom exceed 5 or 6 feet in 

thickness, but there is a maximum exposure of about 15 feet at a locality 2 miles above Middleburg, on Black Creek." 

The maximum thickness of the formation is indicated by well borings to be about 500 feet, 

according to Matson and Clapp. Miocene strata have been identified in well borings as far south 

as Key Vaca, at depths between 375 and 400 feet. 835a 

The Choctawhatchee marl is described by Matson and Clapp ssoe as follows: 

"The Choctawhatchee marl includes the 'Ecphora bed' and 'aluminous clay' of Dall. 

It comprises a grayish sandy shell marl and gray plastic sandy clay of Miocene age. It lies 

stratigraphically between the Oligocene and Pliocene beds and contains characteristic species 

of Miocene fossils. 

"The Choctawhatchee marl rests unconformably upon the Alum Bluff formation at Alum 

Bluff, where the contact shows a wavy surface marked by shallow channels due to erosion. 

At this locality there is also a sharp change from the coarse light-gray sands of the Alum Bluff 

formation, which contain few fossils, to the bluish-gray shell marl of the Choctawhatchee, 

with its abundant fauna. Several years ago Dr. Vaughan noted similar evidence of an unconformity between the Oligocene and Miocene at Jackson's Bluff, on the Ochlockonee River. 

This fact is well shown by his section at that locality. * * * 

"The paleontologic evidence indicates a stratigraphic break between the Oligocene and 

Miocene as is shown by the following quotation: a 

"'As I have on various occasions insisted, the faunal gap between the uppermost Oligocene 

(Oak Grove) and the Chesapeake (Choctawhatchee) or Miocene is the most sudden, emphatic, 

and distinct in the whole post-Cretaceous history of our southeastern Tertiary and indicates 

physical changes in the surrounding region, if not in Florida itself, sufficient to alter the course 

of ocean currents and wholly change the temperature of the waters on our southern coast.' 

"Lithologically the two members of the Miocene in Florida are very unlike, both in character of the material and state of aggregation. The Choctawhatchee marl varies from greenish 

gray to light gray in color and consists of quartz sand containing very large admixtures of shells 

and shell fragments and a smaller percentage of calcareous sand. In some parts of the formation the shells comprise a large percentage of the whole, and they are often in an excellent state 

of preservation. Elsewhere the organic remains form a very subordinate part of the whole 

or they may be entirely wanting. One phase of this formation is distinctly plastic and was 

called 'aluminous clay' by Dall and Stanley-Brown. 

"When examined with a microscope the marl is found to consist of elear quartz sand, of 

medium fineness, coated and partially cemented with calcium carbonate mixed with more or 

less dark clay. The presence of calcium carbonate may be detected by the effervescence when 

treated with dilute hydrochloric acid. There is also a certain amount of dark-colored clayey 

material which appears in the form of a flocculent sediment in water. This material varies 

from light gray to nearly black and is, without doubt, organic matter. In addition, hydrous 

iron oxide may be detected, usually in the form of a coating about the sand grains or as a 

stain along the cracks and on the exposed surfaces of the beds. It is this iron compound which 

sometimes gives the exposed surfaces a rusty color. 

"The Choctawhatchee marl attains a thickness of over 50 feet in the vicinity of Red bay, 

Walton County, where it is exposed in some small ravines and on the banks of Mill Creek; near 

Holland post office, Leon County, its thickness exceeds 30 feet. However, from observations 

elsewhere it appears probable that the average thickness is not more than 25 to 30 feet." 

West of Florida Miocene beds have been recognized in the well of the Mobile Oil Co., at 

Mobile, at a depth of 700 feet, and probably continued to a depth of about 1,100 feet, where 

upper Oligocene fossils representing the Alum Bluff formation were encountered. Beds of 

a Dall, W. H., Trans. Wagner Free Inst., vol. 3, p. 1594. 
810 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

pebbles and conglomerate lying above the Apalachicola group (Oligocene) in this well probably 

indicate an erosion unconformity between the Apalachicola and the :Miocene. 

Miocene rocks are exposed at Shell Bluff, on Chickasawhay River, near Merrill, Miss., the 

type locality of L. C. Johnson's Pascagoula formation. G. C. Matson has discovered that the 

Miocene along the Alabama-Mississippi line is separated by an ero;•lion unconformity from the 

underlying upper Oligocene. Across southern :Mississippi the Miocene is represented by estuarine 

deposits that have not yet been definitely discriminated from the underlying upper Oligocene 

deposits, which are also estuarine and of similar lithology. 

PLIOCENE. 

The marine Pliocene of South Carolina is a southward extension of the Pliocene of North 

Carolina. The principal area lies along Waccamaw River, near Conway, in Horry County. 

The material is yellow, brown, and gray shell marl. Sloan gives the thickness at the mouth 

of Tilly's Lake as 10! feet. 

The Charlton formation of Georgia and Florida, which outcrops along St. Marys River 

from Stokes Ferry, 11 miles south of St. George, Charlton County, Ga., to Orange Bluff, 2 

miles above Kings Ferry, Nassau County, Fla., is probably of Pliocene age. The formation is 

composed of calcareous shell marl, sand, and clay, having a maximum exposed thickness above 

low-water level of about 15 feet. 

The most extensive development of the marine Pliocene in the Coastal Plain area is in 

Florida, where it is divided, largely because of its areal distribution, into two formations-the 

Nashua marl, which occurs along St. Johns River below the town of Nashua, and the Caloosahatchee marl, which takes its name from Caloosahatchee River. Matson and Clapp 580g give 

the following description of these fm'mations: 

"The Nashua marl bears a strong lithologic resemblance to the Caloosahatchee marl. 

There is the same alternation of sand beds with shell marl. The matrix of the Nashua marl, 

while usually calcareous, is always more or less sandy and sometimes consi.sts of nearly pure 

sand. The shells are commonly well preserved, though locally a marl consisting of broken 

and eroded fragments of shells is not uncommon. However, the organic remains are so well 

preserved that it is easy to obtain good collections of fossils from this formation. 

"The K ashua marl is much thinner than the Miocene strata. This fact, together with its 

distribution beneath the lowlands near the coast, indicates that the Pliocene submergence was 

less extensive than the Miocene; and the presence of shallow-water fossils shows that the Pliocene 

sea did not attain any great depth over that part of the State where the marine beds are now 

exposed. The Nashua marl is seldom more than 6 or 8 feet thick, but locally it attains a greater 

thickness. A series of samples of sand and marl from a well at DeLand indicates that at that 

locality this marl has a thickness of about 32 feet. 

"TheN ashua marl occupies the St. Johns Valley, where it underlies a broad terrace bordering 

the stream. It probably occurs beneath the plain east of St. Johns River, but the overlying 

Pleistocene forms such a thick mantle that the Nashua marl has no influence on the topography. 

On the whole, this formation has little or no influence on the topography of the State. 

* * * * * * * * * 

"The Caloosahatchee marl consists of a light-gray shell marl which is often interbedded 

with nearly pure sand. The matrix is usually very calcareous, but locally it consists of sand 

and even in the most calcareous portion sand is abundant. The shells are remarkable for their 

excellent state of preservation and their abundance in certain layers makes it possible to secure 

excellent collections. 

''It is difficult to form a correct estimate of the thickness of the Caloosahatchee marl, but 

its maximum is probably about 25 feet. Single exposures seldom exceed 5 to 10 feet, and the 

average thickness is probably less than 8 feet. On the whole the Caloosahatchee marl is probably 

to be regarded as thin, though it may thicken considerably toward the central portion of the 

peninsula and toward the southern end of the State. 
LATER TERTIARY (MIOCENE AND PLIOCENE). 811 

"The Caloosahatchee marl occupies a region of such low altitude that it has only been 

slightly dissected. In fact, with the exception of the valleys of the streams entering Charlotte 

Harbor the surface of the region underlain by this formation is an almost unbroken plain. 

While this is doubtless in part due to the later deposit of Pleistocene sand, it is doubtful if 

the surface of the Caloosahatchee marl has ever been greatly eroded." 

The nonmarine Pliocene of Florida includes the Alachua clay and the Bone Valley gravel. 

The Alachua is thus described by Matson and Clapp: 580h 

"The Alachua clay is known to occupy depressions such as sinks and gullies in the Oligocene and probably also in the .Miocene beds. Observations made by Dall along the banks of 

Peace River have established the fact that a bone bed ('Peace Creek bone bed'), which he correlates with the Alachua clay, rests upon older Pliocene beds. The relation between the Alachua 

clay and this bed on Peace Creek has not been observed, but they are believed to be lacustrine 

or fluviatile deposits which may have been formed at about the same time. The Alachua 

clay is also thought to be contemporaneous with a part of the Caloosahatchee and Nashua 

marls. It consists of blue to gray sandy clay which weathers to light yellow or red from the 

presence of iron oxide. There is usually sufficient clay to give the material a distinct plasticity, 

and sand is commonly present in considerable quantities. The weathered material is frequently more or less concretionary as a result of the aggregation of the iron oxide. The formation is nearly destitute of fossils except in a few localities where it is filled with vertebrate 

remains." 

As the accumulations took place in depressions of the surface of the Oligocene beds, the 

thickness is variable. In places it is 15 feet or more, and the average thickness is probably 

not less than 10 feet. 

The Bone Valley gravel, which comprises nearly all the pebble phosphates now being 

mined in Florida, derives its name from a locality west of Bartow, where the beds are exploited 

on a large scale. Eldridge designated this deposit land pebble phosphate, while Dall called 

it simply pebble phosphate, both writers distinguishing between the Tertiary deposits of Pliocene age and the younger pebble phosphates, which vary in age from Pleistocene to Recent. 

The deposits, according to Matson and Clapp, 580i "arc situated in the valleys of streams and vary 

in altitude from less than 25 feet to nearly 100 feet above tide. Lithologically the formation 

is composed of very poorly assorted materials, such as clay and phosphate pebbles, which 

usually show some evidence of stratification. * * * The poor assortment of the materials 

and the absence, locally, of distinct stratification point rather to fluviatile than marginal origin. 

It is, however, probable that some of the deposits were made in the margin of estuaries. The 

presence of such organic remains as bone fragments and shark's teeth is readily explained by 

the fact that the phosphatic gravels were derived from older formations in which such materials 

occurred. 

"The Bone Valley gravel rests upon beds of Pliocene or older rocks, and the relation is 

probably unconformable, but the poor e.;x:posures make it impossible to observe contacts except 

in a few localities. For this reason it may not be safe to postulate an unconformity between 

the Bone Valley gravel and the underlying Pliocene marls, though the contact with the postPliocene beds is certainly unconformable. * * * 

""While the exact correlation of this formation is somewhat uncertain, it is believed to be 

younger than the 'Arcadia marl' and older than the upper beds of the Caloosahatchee marl. 

It is probably in part contemporaneous with the Alachua clay. * * * 

"The exposures frequently reach a depth of more than 30 feet, without encountering 

the underlying beds, and hence the maximum thickness may be safely fixed at more than 30 

feet. The average thickness, however, is probably lower and it may not exceed 15 to 20 feet." 

West of Florida the presence of Pliocene rocks has not been definitely determined. It is 

probable that a portion of the 700 feet of strata above the Rangia johnsoni bed in the Mobile 

well is Pliocene. Berry examined outcrops and collected fossil plants in Alabama at a point 
812 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

1 mile south of Lambert, Mobile County (elevation about 325 feet), and at Red Bluff, Perdido 

Bay (just above tide). He bases the following opinions a upon studies of the fqssil flora: 

"Red Bluff is obviously of the same age as the outcrop near Lambert and the same age 

as the bluffs on Mobile and Pensacola bays. The flora, considered with that of the locality near 

Lambert, is decidedly modern in its facies as compared with the other so-called 'Grand Gulf' 

outcrops which contain fossil plants, the difficult question being to differentiate between Pliocene and early Pleistocene. The flora is a mixture of swamp types and those of live-oak barrens and indicates climatic conditions such as occur along the Gulf coast to-day, as, for example, 

on the Santa Rosa Peninsula. 

"In the absence of any American floras for comparison I am disposed to regard the age of 

the deposits as Pliocene, as the species are nearly all extinct and embrace positively identified 

genera (for example, Trapa) which no longer occur in North America." 

The Lafayette formation was first discriminated by E. W. Hilgard in 1855 and 1856, and 

named by him in manuscript from Lafayette County, Miss., but the name was not published 

until 189 I. This formation was included in the Orange sand of Safford in Tennessee and the 

Orange sand cf Hilgard in Mississippi. In 1888 McGee 565a applied the name Appomattox to 

the formation from "the river of typical development in the middle Atlantic slope." McGee's 

name Appomattox antedates the publication of Hilgard's Lafayette by about three years, 

but a fact that is perhaps more to the point is that the recent studies of Berry, Lowe, and others 

around Oxford, Miss., have shown that exposures in Lafayette County, formerly regarded as 

typical Lafayette formation, are of ·wilcox (Eocene) age, rendering very doubtful the propriety of applying the name to deposits of probably late Pliocene age. The nomenclature has, 

therefore, been unsettled by the attempt to supplant McGee's Appomattox and must temporarily 

be regarded as only tentative. From the evidence now in hand it seems probable that the term 

Lafayette for the deposits presently to be described will have to be abandoned, and McGee's 

Appomattox be revived. However, McGee's usage in his paper "The Lafayette formation" 

will be followed here. 

According to McGee,S66a "In composition the Lafayette formation is a bed of loam, sand, 

and gravel, with several minor elements, notably kaolin or kaolinic clay, comminuted silica or 

siliceous clay, etc. The clay element of the loam and much of the sand are evidently residua 

derived from decomposition of a variety of older rocks, the local characters generally reflecting the characters of local terranes; the gravel and a part of the sand represent the terranes 

traversed by the upper reaches of the rivers along which they are found; and the gravel varies in 

abundance and size with the volume, declivity, etc., of theserivers. 

"In geographic distribution the Lafayette formation coincides approximately with the 

Coastal Plain of the southeastern United States. In hypsographic distribution the formation 

ranges from altitudes of 700 or 800 feet to probably some distance below tide level. 

"In thickness the Lafayette deposits range from a mere veneer over many interstream tracts 

to 200 feet or more about the mouth of the Mississippi; and in general the thickness varies 

directly with the volume of neighboring rivers and inversely with the inland extension. The 

formation has, however, been degraded from considerable areas, particularly along the larger 

waterways. 

"In structural relation it is separated from the newer Columbia formation by the strongest 

unconformity of the Coastal Plain, an unconformity representing degradation of probably half 

the volume of the Lafayette formation and profound trenching of subjacent formations along 

the larger waterways; and it is separated from all of the underlying formations by a noteworthy unconfoctnity of such character as to indicate that during pre-Lafayette time the 

Coastal Plain was a land s·urface and was wrought into a configuration much like that existing 

to-day. ·---------------------------------------------------------------------- a "Cnpublished manuscript. 
LATER TERTIARY (MIOCENE AND PLIOCENE). 813 

"In structural composition the formation is a unit, varying from place to place in local 

characters yet indivisible throughout its area of 250,000 square miles, save on arbitrary grounds." 

The formation is important especially in the interstream areas across South Carolina, 

northern Florida, and each State from Georgia to southern Illinois. 

PLEISTOCENE. 

Marine Pleistocene deposits cover considerable areas along the coasts of South Carolina 

and Georgia and are greatly developed in Florida, where Pleistocene marls, coquina beds, a.nd 

limestones underlie over half the present land surface of the State. a 

Below the Lafayette level in the south Atlantic and Gulf Coastal Plain States are several 

persistent terraces above the present flood plain, representing McGee's Columbia group. From 

Georgia to Tennessee there are at least two-( a) one major terrace between the Lafayette and the 

"second bottoms" and (b) the "second bottoms." The loess of the Mississippi seems correlative 

with the major terrace below the Lafayette level. The terraces slope coastward and merge 

with shallow-water and estuarine deposits, to which in Louisiana Hilgard has applied the 

name Port Hudson group. 

H-J 13-14. GREAT PLAINS, COLORADO, KANSAS, OKLAHOMA, NEW MEXICO, AND TEXAS. 

Darton 238e maps the Miocene (Ogalalla and Arikaree formations) southward 

from Nebraska (see p. 822) through Colorado and Kansas into Oklahoma, Texas, 

and New Mexico. The following notes are taken from a paper by Gould: 3730 

Lying unconformably upon the surface of the red beds and Cretaceous over a large part of 

western Oklahoma is an extensive deposit of Tertiary rocks, the exact age of which has never 

been determined with accuracy. Paleontological evidence is rare, but, following the usual 

classification of beds of apparently the same age in western Kansas and Nebraska, there seems 

no valid reason for not considering them Miocene or Pliocene. * * * 

With the exceptions of the alluvium and sand hills the Tertiary is the uppermost formation in Oklahoma. The red beds underlie it, except that between the red beds and the Tertiary 

occur sometimes Comanche Cretaceous members. * * * 

In general the later Tertiary occupies the uplands of the western half of Oklahoma, almost 

always occurring on the high divides between the streams. * * * 

The Tertiary consists for the most part of clay, sand, and gravel. These materials are in 

no regular stratigraphic succession. * * * In places the entire thickness of the formation 

is clay; again sand and gravel predominate, and often deposits of different character will be 

interbedded. * * * 

The clay is usually white or pinkish and sometimes forms steep banks or cliffs along the 

bluffs or around the heads of canyons. To the harder ledges the name "mortar beds" has 

been applied. * * * 

The sand is of various degrees of fmeness and is composed for the most part of quartz, 

although other minerals are present. The grains, when examined under the microscope, are 

usually rounded. * * * 

"Tertiary pebbles" is the term usually applied by geologists to the smooth, rounded, 

waterworn pebbles scattered abundantly over the slopes and points throughout western Oklahoma and Kansas. These pebbles have been washed out of the Tertiary deposits, of which 

they often constitute a moderately lurge proportion. They are frequently cemented together and 

form a hard conglomerate rock known as Tertiary grit, which on exposure forms conspicuous 

ledges. * * * -- - -~-~----- ------ a For detailed information see papers un Florida by Sanford "93 and Vaughan.'"5 
814 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The pebbles are of all sizes, from coarse sand to stones several inches in diameter. Quartz 

is the principal mineral, granite, feldspar, and other minerals also being present. * * * 

It is probable that the Tertiary deposits at one time covered the entire western part of 

Oklahoma. The valleys of the present streams have been carved in these deposits, and in 

many parts of the Territory all traces of the Tertiary are gone, except scattered quartz pebbles. 

The thickness of the formation varies with the locality, being greatest on the high divides. 

Throughout a large part of western Oklahoma its thickness averages 100 feet or more, while in 

a few localities distant from the streams it may reach as much as 300 feet. On the other hand, 

in a great many places there is but a thin blanket of the deposit over the red beds. 

I 10-11. SANTA BARBARA COUNTY AND SOUTHERN CALIFORNIA. 

Arnold and Anderson 32 thus describe the Monterey shale (Miocene) in the Santa 

Maria oil district, California: 

A great series of fine shales, largely of organic origin, overlies conformably the coarse and 

fine sedimentary deposits of the Vaqueros. These shales make up the Monterey formation and 

are representative of the whole of middle Miocene t.ime. The formation is of great thickness and is doubly important as the probable source and the present reservoir of the oil. The 

areal extent of the Monterey is not adequately represented on the map. It doubtless covers 

as one continuous sheet the whole basin between the Santa Ynez and San Rafael mountains, 

as well as a large part of these ranges, but it is covered over considerable areas by later deposits, 

which are in many places very thin. The character, structure, and relations of the Monterey 

have been the chief subject of the present study. 

The name "Monterey" was given by William P. Blake a in the early fifties to an organic 

shale formation typically developed in the vicinity of Monterey, in Central California. It is 

very extensive in the California Coast Ranges, being the "bituminous shale" series described by 

Whitney in the reports of the Geological Survey of California as occurring at widely separated 

points north and south of the Golden Gate. Its age is generally considered to be middle Miocene. It is the source of much of the petroleum found in California. The shale that characterizes this unique formation is not similar to ordinary clay shale but is composed largely of 

the remains of minute marine organisms. In its unmetamorphosed condition it resembles 

chalk but is of siliceous instead of calcareous composition. 

The Monterey in the part of California treated here may be divided on lithologic grounds 

into two parts, although there seems to be perfect conformity throughout the formation. There 

is no definite dividing line to be drawn, but taken as a whole the lower half, composed chiefly 

of hard, metamorphosed, in places flinty shales, is distinct from the upper half, in which soft 

shale, giving evidence to the naked eye of its organic origin, is predominant. 

The following summary description of the stratigraphy of the Summerland 

district, Santa Barbara County, is quoted from Arnold: 30 

The formations involved in the geology of the Summerland district are 9,000 ± feet of conglomerate, sandstone, and shale of the Topatopa (Eocene); 4,300 ± feet of conglomerate, sandstone, and shale of the Sespe (Eocene or Oligocene); 2,400 ± feet of sandstone and shale of the 

Vaqueros (lower Miocene); 1,900 + feet of shale and volcanic ash of the Monterey (middle 

Miocene); 1,000 + feet of conglomerate, sandstone, and clay shale of the Fernando (upper .Miocene-Pliocene); and 50+ feet of gravel, sand, and clay of the Pleistocene-in all, 18,650 ± feet 

of sediments, practically all of Tertiary age. Unconformities occur between the Monterey and 

Fernando formations and between the latter and the Pleistocene. 

a Proc. Acad. Nat. Sci. Philadelphia, vol. 7, 1855, pp. 328-331. 
LATER TERTIARY (MIOCENE AND PLIOCENE). 815 

Tentative correlation of formations of Summerland district with the standard California Ooast 

Range and Santa Clara Valley sections. 

--~1,-

Era. i System. Series. Standard Coast Summerland district Santa Clara 

Range section. j section. Valley section. 

Cenozoic. 

Mesozoic. 

Quaternary. ! 

Tertiary. 

Recent. Alluvium. ~--~~luvium. I Alluvium. 

-- ------------[- . -- ~--------~- - --~--

pl . S , p d 1 

::\Iarn~e and stream de- I Sand and "ravel. e1stocene. a;l e ro. 

1 

posits. 1 " 

1 ---- - f · I u f · --lJnconformity-! -- Jllcon orm1ty~-:- --- neon ormlty--

Merced. II I 

Pliocene. I 

I 

I I 

uns1ma. I Fernando. Fernau o. 

I 

P .. I i' d 

------~------------------ --1 'I San Pablo. I 

:Miocene. 

Oligocene. 

. -Unconformity--~-- --Unconformity----- ~-Unconformity-.-

.:'llonterey. Monterey . !

Shale. 

Upper sand-

'I d 1 stone. 11 0 e 0 Shale. 

Lower sandstone. 

- ---------------1----------------

! Vaqueros. Vaqueros. Vaqueros. 

i I {Red beds. ~- {Upper. 1 San Lorenzo. · Sespe Lower s a n d - II Sespe Red beds. 

I I stone. I. Lower. 

-

1 ---Unconformity? -,---------i---------

1 

iT· 

Eocene. ! ~----- Topatopa. 

I

I !Martinez. 

Topatopa. 

-----:-------~--Unconformity?-_' 

Chico. 1 

I 

-Unconformity--

Horsetow:n. 

·-Unconformity--

Knoxville. 

Cretaceous. 

------------

1 

I 

Jurassic (?). I 

I __ _ 

--Unconformity--

Franciscan. 

--UnconformityGranite, schist, etc. 

(?) 

Franciscan? (fide Whitney). 

I-J 10-11. COAST RANGE, CALIFORNIA. 

(?) 

--lJ :nconformi ty--

Gra:ni te, gneiss, etc. 

Lawson 525 states, in a paper on the geological section of the middle Coast 

Ranges: 

The paper is an attempt to summarize recently acquired information as to the sequence of 

formations and their respective volumes of sediments in the middle Coast Ranges of California. 

The results given for the thickness are approximations sufficiently close to afford a general idea 

of the section. Other features of the paper are the subdivision of the Franciscan into seven 

stratigraphic subdivisions by the recognition of a persistent horizon of foraminiferal limestone 

and two important horizons of radiolarian chert; a similar subdivision of the Monterey into 

seven stages and a summary announcement of the character and history of the post-Monterey 

Tertiary. The essential features of the paper are given in the following tabulation: 
81G INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Geological section of the Ooast Ranges of California in the vicinity of the Bay of San Francisco. 

Merced: Feet. 

Upper marine sandstones, sandy shales, and clay shales ............................. 1 

Lower marine clays, sandy shales, sandstones, fine pebbly conglomerates ............. J 5•

830 

Unconformity. 

Cam pan: 

Volcanics, andesites, basalts, rhyolite agglomerates ............ : ...................... } 

Fresh-water conglomerates, sandstones, clays, limestones ........................... __ . 500 

Unconlormity. 

Upper Berkeleyan: 

~~~t:~~c;;e~~~;~;~:~~;~~~i~~st~~-~~.- ~~~d~t~~~~: ~h~i~~,· ii~-it~: t~ffs~ -~~~~i~~~~~t~~-·.: l 200 

volcamcs, andesltes, basalts, rhyohte tuffs .......................................... f 

Unconformity. 

Lower Berkeleyan: 

Volcanics, and_esites, basalts, rhyolite tuffs ................ -... -.. ---------------··· -} 2,

000 Trampan, marme shales, sandstones, pebbly conglomerates ............. _. _. _ ....... . 

Orin dan, fresh-water conglomerates, sandstones, clays, limestones, tuffs ........... _._.. 2,400 

Pinole: Tuffs (pumiceous) fossiliferous ................................ _ .............. _ .. 1,000 

San Pablo: Blue tuffaceous sandstone, marine ............................. _ .... _....... 1,500 

Unconformity. 

Monterey: 

Upper: Stage 7-Sandstone .................... _ .. ____ .. __ .................... _... 1,800 

Middle: 

Stage 6-Bituminous shale . ___ . _. _ ....................... _. _. _. __ .......... _. _ 

Stage 5-Sandstone .............. _ ........ _. _. _ .......... _. _ ...... _ .......... . 

Stage 4-Bituminous shale ... _. _ .................... _ .. __ . _. __ . _ ............ _. 

Stage 3-Sandstone .......................... _ ................... _. _ ......... . 

Stage 2-Bituminous shale and chert ..... __ ... _ .......... _ ... _. _ ............... . 

Lower: Stage l-Sandstone ........................... _. _. _ .............. _ ... _ .... . 

Unconformity. 

Karquinez: 

Tejon: Massive sandstones .................. _._ ................................... . 

Martinez: Massive sandstones ........... _ ............................... _._ ........ . 

Rhyolite flows (age not certainly determined). 

Unconformity. 

Shasta-Chico: 

Chico: Sandstones and shales ............. _._ ... _ .................... _ ............. . 

Oakland: Conglomerate ........ _ ........ _._ ..................... _ .. _ .............. _ 

Peridotite irruptions. 

Knoxville: Shales with subordinate limestone and conglomerate .................... _ 

Unconformity. Volcanics. 

Franciscan: 

Bonita sandstone ................................... _._ ................ __ ._ ....... . 

San Miguel cherts, radiolarian ....................... _ .. _ .................. _ . _ .... . 

Marine sandstone ............................. ___ . _ ................ -............. - . 

Sausalito cherts, radiolarian ... _ . __ .. _ ...... _ .. _ .......... _ .. ____ ....... _ .. ___ .. _ .. . 

Bolinas sandstone (volcanics) ......... _ .. _. __ ._ ........ _ ............. _ .. _ ........ _ .. 

Volcanics. 

Calera limestone, foraminiferal. .. _ . _ ...... _ . _ .. _ ........... _ .. _ ........ _ . _ ......... . 

Volcanics. 

Pilarcitos sandstone ........ _ . _ ........... _ .. _ ........ _ . _ . _ ........... _ ....... _ .. _ . 

Unconformity. 

Montara granite (correlated tentatively with late Jurassic granite of Sierra Nevada). 

670 

1,200 

460 

600 

250 

400 

2,100 

2,200 

3,000+ 

500 

1,000 

1,400 

530 

1,000 

900 

2,000 

60 

790 

34,290 

In the hills west of Tulare Lake, southern California, lies the Coalinga oil district 

studied by Arnold and Anderson/4

d who thus describe the post-Eocene formations: 

The periods following the Eocene are here represented by a great series of sandstone, shaleand conglomerate beds, all tilted at about the same angle, having usually similar character, 

istics, and presenting an appearance of conformity and intergradation. By means, however, of 

discontinuous fossil faunas, distinguishable lithologic groups, the absence in some places of formations or zones known elsewhere, as a result of erosion and the overlappmg of later beds, and 

the appearance of fragments of older formations within younger ones, several important breaks 
LATER TERTIARY (MIOCENE AND PLIOCENE). 817 

may be definitely made out, which prove the intervention of periods of time during which land 

conditions existed over wide areas or locally. The important post-Eocene formations that 

represent the epochs of submergence of the land in the area now occupied by the Coalinga 

district are the Vaqueros (lower Miocene), the Santa Margarita ( ?) (upper middle Miocene), 

the Jacalitos (early upper Miocene), the Etchegoin (late upper Miocene), and the Tulare (Pliocene and lower Pleistocene) formations. The Tulare formation is probably in large part of 

different origin from the others but is similar to them in the general features of its appearance. 

These formations are all united into one series in the monocline dipping down the east flank of 

Joaquin Ridge in the northern part of the district and again in the monocline dipping away 

from Reef Ridge in the southern portion, but the character of the series is not entirely the same 

in the two regions. 

In the northern part of the district the base of the Miocene-Pliocene is formed of coarse and 

fine oil-impregnated sands unconformably overlying the whitish and purplish petroliferous 

Eocene (Tejon) shales, these sands being overlain by prominent sandstone beds (the "reef beds"), 

a prominent zone of white siliceous shale (the "indicator"), and soft sand up to the base of a 

zone of bluish-gray and variegated clay, sand, gravel, and serpentine detritus locally known as 

the Big Blue. Up to this point the beds are fossiliferous, have a thickness of about 550 feet, and 

are mapped as Vaqueros (lower Miocene). The Big Blue has a thickness of about 300 feet and 

is nonfossiliferous. It corresponds in stratigraphic position to the Monterey shale (middle 

Miocene) of regions nearer the coast, but nothing has been discovered to indicate that it may 

belong to that formation. It is overlain by a thickness of about 17 5 feet of sand, sandstone, and 

conglomerate beds full of immense oysters, barnacles (Tamiosoma), scallop shells (Pecten), and 

other fossils. These fossiliferous beds will be referred to as the Tamiosoma zone. They are 

overlain by 400 to 500 feet of sand and gravel beds up to the base of a very prominent gravel 

zone full of petrified wood. The beds from the base of the Big Blue up to this point are mapped 

as the Santa Margarita (?)formation (upper middle Miocene). The gravel zone with fossil wood 

forms the base of a succession of sand, sandstone, gravel, and clay beds extending up to the base 

of a prominent zone of bluish-gray sand beds having near their base a rich fossil bed, the Glycymeris zone. The succession of beds up from the base of the fossil-wood gravel zone to this point 

has a thickness of about 1,600 feet and is mapped as the Jacalitos formation (early upper Miocene). 

The fossil bed (Glycymeris zone) and bluish sands immediately overlying grade upward into 

sand and clay beds, the whole forming a thickness of about 1,700 feet, which is mapped as the 

Etchegoin formation (uppermost Miocene), and this finally is overlain by poorly exposed coarse 

gravel deposits, which are mapped as the Tulare formation (Pliocene-lower Pleistocene). The 

total thickness of the succession in the Coalinga field thus outlined is about 4,600 feet, exclusive 

of the Tulare formation, which can not be measured in this portion of the district. 

In -t.he southern part of the district the basal portion of the Miocene-Pliocene series consists 

of about 700 to 900 feet of steeply dipping hard sandstone and conglomerate beds forming the 

face of Reef Ridge. These overlie, with an important though usually not apparent unconformity, 

the shale of the Tejon (Eocene) and are locally petroliferous. At the summit they grade into 

softer beds which are overlain by hard siliceous shale. Up to tlus shale the beds are fossiliferous 

and are mapped as the Vaqueros formation. The overlying shales are hard and whitish, form a 

prominent zone varying up to 1,200 feet in thickness, and are mapped as Santa Margarita (?), 

although only tentatively referred to that formation. These shales are overlain by a great succession of beds of sandstone, shale, sand, clay, gravel, and conglomerate of many varieties, having a thickness as measured in a section south of Big Tar Canyon of about 9,500 feet. This 

succession is divided on the map, on the basis of criteria to be discussed later, into three approximately equal divisions corresponding to the formations in the north, namely, the Jacalitos (early 

upper Miocene), Etchegoin (uppermost Miocene), and the Tulare (Pliocene-lower Pleistocene). 

The total thickness of the Miocene, Pliocene, and lower Pleistocene series measurable in the 

above-mentioned single section is over 11,000 feet. 

The following table, from Arnold and Anderson's report/4 gives a correlation of 

the Mesozoic and Cenozoic formations of the California Coast Range: 

4801] 0 --12----52 
Tentative correlat:ion offormations rif Ooali,nga district with the standard California Ooast Range sedion and those 1if oth rr localities ·in r'a {~fom ia. 

! 

Era. I 

Sys- Serie;;. 

I 

tern. 

-~~ ----

"'' Recent. '" "' .::: ----- '" (j) 

~ PleistoCt cene. 

---

Pliocene. 

<.) 

·s 

" 0 

.::: >.. Miocene. (j) 

0 '" ·E 

'" (j) 

['-< 

Oligocene. 

I Eocene. 

I 

--! 

I do ~ 

I ~0 

'"' (j) 

! 

Vc., 

. ;:: 

fitandard ( 

Range Bee· 

Alluvium. 

------

San Pedro. 

Unc.--1 

.Merced. 

Han Dit·go. 

San Pablo. 

~ o a s t 

tion. I 

Santa .l\f aria district Santa Clara \'alley 

Coalinga district section. section. (Ventura County) 

! 

section. 

8t;e~I;l~ongl;Jmer~t;;-;;,r~d ~~-.-------. 

alluvium. 1 uvmm. Alluvium. 

-Stream deposits, valley I Terrace deposits and T err a c e deposits, 

fillings, and raised beach. dune sand. sand, and gravel. 

.. --Unconformity----unconformity----unconformity--

Tulare. 

--unconformity---! 

Etchegoin. I Fernando. Fernando. 

---Unconformity---~ 

Jacalitos. 

-unconform 

Santa .Marga 

-Unconfor 

---u nconformity----r 

Santa Margarita(?). 

--U nconforrnity-----Unconformity--

ity ('?)-

rita. 

mity--- --Unconformity--' 

Monterey. 

Lacking (with possible 

exception of a small Monterey. 

part). 

-Unconforr 

Vaqueros. 

Unconfor I San Lorenz 

I Unconform 

I 

Tejon. 

.l\lartine;r,. 

unconforr 

I Chico. 

\'aqueros. \ Yaqneros. 

Unconformity 

(?) 

uit.y--

mitv-----

o. • Wanting(?) i) 

it , (?)- I' Sesl?e and ~'ejon un- J · • T · differentiated. I e]on. 

-------Unconformity---, I • I 

uity--' 

('hi<"o. 

I 

Or"'' Q) Upper sandstone. 

"§ Shale. 

;:;;j Lower sandstone. 

Vaqueros. 

a5 {Upper beds. ~Red beds. 

(;5 Lower beds. 

Topatopa. 

;-Unconfon 

I Hor;;etown. niiy-- 1 

I 

'-Unconfor 

I 

-----·-· ----- --· ----.---------

Los Angeles and 

Puente Hills sec- tion. 

Alluvium. 

Terrace deposits, 

sand, and gravel. 

Santa ( 'ruz ::\"lountains 

section. 

Alluvium. 

Terrace deposits, sand, and 

graYel. 

--Unconformity-----Unconformity--- ! 

Men·ell. I 

Santa Clara. 

Fernando. Purisima. 

1-------~-----

Santa Margarita. 

--Unconformity-----U nconform it::-

Upper shale. 

C) 

§ Sandstone. 

~ 

Lower shale. 

.l\1ont erey. 

1

---U IJ<'<mformit) ---

Vaqueros. 

!-----·-~---- --

San Lorenzo. 

--Unconformity(?)---

Undifferentiated Eocpne, 

probably Martinez. 

---Unconformity (? )--

Chico. 

I Knoxville. mity~• ·I , Knoxville. Knoxville. , KnoxYille . 

0 Unconforr 

" 0 · I Franciscan. oc J.~ ~C'-· -Unconfor 

nity--· ---Unconformity----unconformity-- I ---Unconformity---

Franciscan. Franciscan. Franciscan. 

(j) mity--, -Unconformity--~-unconformity-----Unconformity---

;:;:j ,.,~ I Granitic r ;j <.) ....,.~ 

w schist, etc 

1 

Unconfor 

(?) Schist; lime 

o c k s , i Granitic r o c k s , Granitic r o c k s , Granitic rocks. 

1 gneiss, etc. gneiss, etc. ~ity--' -Unconformity-----Unconformity---

stone. I j Black schist. Schist; limestone. 

--- ---~ 
LATER TERTIARY (MIOCENE AND PLIOCENE). 819 

J-K 11. NEVADA, OREGON, AND IDAHO. 

The .Miocene and Pliocene sediments of Nevada and adjacent parts of Oregon 

and Idaho have been described by King under the names Truckee and Humboldt, 

respectively, and Cope has applied the name Idaho formation to certain Pliocene 

deposits. King 505g postulates an extensive lake (Pah-Ute Lake) and says: 

The beds of this lake, to which, in the Fortieth Parallel area, I have given the name of 

Truckee Miocene, are made up of, first, detrital rocks and gritty sandstones, with more or less 

conglomerate, never over 150 feet. Over this lie about 250 feet of palagonite tuff, which, for 

reasons already described, is referred to the age of the augite andesites; over this, 250 to 300 

feet in Nevada, with a greater thickness in Oregon, of infusorial silica, followed by 120 feet of 

sandy, gritty rocks, purely detrital, but containing alw~ys a considerable amount of infusorial 

silica, succeeded by a fresh-water limestone of about 60 feet, in its turn succeeded upward by 

250 feet more of detrital grits, which give way to an enormous formation of volcanic tuffs of 

the trachytic period. The thickness of these trachyte muds in Nevada can not be less than 

2,000 or 3,000 feet; in Oregon, according to the observation of Prof. Marsh, they are even 

more fully developed. It is in these volcanic muds that the enormously abundant Miocene 

fauna of this lake is mostly entombed. Out of the grits overlying the limestone in Nevada 

have been obtaine<l teeth of a rhinoceros, probably R. pacificus. 

At the close of the Miocene, according to King, the Truckee strata "were 

thrown into bold folds, their dips reaching angles of 30°." Louderback 547a recognizes "a certain amount of deformation in later Tertiary." 

Ball 54a gives an account of the relations of igneous rocks and lake beds in 

southwestern Nevada and eastern California, from which the following partial 

columnar section and extracts are taken: 

Columnar section [in part] of rocks of southwestern :Vevada and eastern California. 

Quaternary. 

Tertiary. 

---------,---------------------------------~~ 

Pleistocene and Recent. Older nlluvium, with PliocenE' lake beds nt base. 

Pliocene. 

Rhyolite. 

--Unconformity---------------------------------

Siebert lake beds, with rhyolite and ba,alt flows. 1---------------·- ·~-- ------· 

Rhyolite. 

---------:--"Cnconformity----------------------------

Dasic andesite. 

Miocene. 

Second rhyolite, with minor basalt flows. 

----------1-------

Monzonite porphyry and acid andesite. 

Eocene. ---Unconformity----------

First rhyolite. - ------,--·-·-·--·-----Unconformity-------------------

Carboniferous. I Pennsylv:tni:cm. 

The Tt>rtiary rocks include a numbt>r of igneous rocks, lava flows, and fewer intrusive 

masses, and sediments laid down in lakes. * * * 

The oldest of the Tertiary rocks is a rhyolite which occurs in Stonewall Mountain. This 

occupies a similar stratigraphic position with rhyolites in the Panamint Range, in the Randsburg district, and near Daggett in the Mohave Desert, which, according to Spurr, lie beneath 

"lake beds which are probably, in part at least, Upper Eocene." This rhyolite in Stonewall 

Mountain is cut by dikes of quartz monzonite porphyry and quartz syenite, which are probably 
820 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

contemporaneous with monzonite porphyry, quartz monzonite porphyry, hornblende-biotite 

latite, and biotite andesite of other ranges. These rocks are in part intrusive masses and in 

part flows. Prior to the succeeding extrusion of rhyolite these rocks * * * were eroded, 

unconformities being observed in the Kawich, Amargosa, and Cactus ranges, in the Bullfrog 

Hills_, and in Shoshone and Skull mountains. Then followed an extrusion of rhyolite, with 

minor siliceous latites and dacites, which was attended by insignificant basalt flows. This 

period of extrusion of rhyolitic lavas, the most important in this portion of the Great Basin, 

was not, however, strictly contemporaneous over the whole area. * * * This rhyolite is 

everywhere separated from the Siebert lake beds by a marked erosional unconformity, and 

in the Kawich and possibly in the Cactus Range it is separated by an erosional unconformity 

from the succeeding andesites. The next younger igneous rocks * * * are basic andesites. These two rocks were found in contact only in the area covered by the Goldfield special 

map, and here Mr. F. I.~. Ransome found dacites intrusive into the andesites. The succeeding 

igneous rocks are rhyolites and siliceous latites and dacites which occur only in the Goldfield 

and Southern Klondike hills and the Silver Peak Range. In the latter two localities at least 

these rocks are interbedded with the Siebert lake beds without erosional unconformity. 

Thick masses of sediment occur in the majority of the ranges of the area and on lithologic and stratigraphic grounds are correlated with the Siebert lake beds of Miocene age at 

Tonopah described by Spurr. These tuffaceous sandstones and conglomerates, largely composed of rhyolitic material, reach an observed maximum thickness (in the Amargosa Range) 

of 1,150 feet. * * * 

The succession of the lavas of the Great Basin has recently been treated at length by 

Spurr.a His succession for the petrographic province of the Great Basin and that of the writer 

for the portion of that province here treated are practically identical. Both assign "the first 

rhyolite to the end of Cretaceous and to Eocene time. It is believed, however, from the length 

of time indicated by the complex history of extrusion and erosion intervening between this 

rhyolite and the deposition of the Siebert lake beds, that the monzonites and acidic andesites 

may well also be in part Eocene, while the second rhyolite is believed to be largely of early 

Miocene age. The andesite and dacite are also of comparatively early Miocene age, while the 

third rhyolite covers the middle and late Miocene and early Pliocene. The basalts range in 

age from late Miocene to Pleistocene; the major extrusions occurring in late Pliocene and Pleistocene time. As to the genetic relations of the magmas, the writer is wholly in accord with 

the v.iews of Spurr in the article already cited. He believes that the Tertiary lavas of the 

Great Basin are the representatives of two complete cycles of the differentiation of a magma 

of medium composition into acidic and basic lavas and that probably the end of a still earlier 

cycle is also represented. 

K 10. NORTHERN CALIFORNIA. 

Miocene and Pliocene deposits occur in the old valleys of upper Sacramento 

and Trinity rivers, on the southeastern slope of the Klamath Mountains and west 

of Lassen Peak. They comprise auriferous gravels, fresh-water sediments with 

some coal, allied to the lone formation, and tuffs. These deposits have been 

described by Diller, 272• 

276a Anderson, 28 ·and Hershey. 436 

K 11-12. NEVADA, UTAH, AND IDAHO. 

Only the later Tertiary (Pliocene) is represented in the northern and eastern 

parts of the Great Basin. King 505r states: 

Along the western base of the Wasatch a portion of the terrace country, rising to 700 or 

800 feet above the level of the lake, is composed of loose, friable Tertiaries, carrying very 

a Spurr, J. E., Jour. Geology, vol. 8, 1900, pp. 621-646. 
LATER TERTIARY (MIOCENE AND PLIOCENE). 821 

recent fresh-water mollusks, the genera at least being chiefly the equivalents of existing types. 

These beds along the western base of the Wasatch are approximately horizontal. Three considerable depressions east of the main ridge of the Wasatch-Morgan, Cache, and Ogden valleys-which unquestionably represent bays formerly connected with the main Pliocene lake 

west of the Wasatch, have been receptacles of Pliocene sediments very similar to the .fragments of horizontal Pliocene terraces on the west base of the Wasatch. They are all characterized by recent genera of fresh-water mollusks. The height of the Tertiary in all these 

valleys -reaches a full thousand feet above the level of Salt Lake. 

·with the exception of terrace masses along the western base of the Wasatch, which for 

the most part are deeply covered by Quaternary deposits, the valley of Salt Lake carries a. 

sheet of Quaternary, through which rise masses of Paleozoic and volcanic rocks. The northern. 

boundary of this great basin is beyond the limits of our map but has been crossed by us in 

several places, and the members of the exploration have been unanimous in referring to the: 

Pliocene period a considerable series of horizontal rocks which occupy a divide between the 

waters of the Utah Basin and those of Snake Valley. These rocks are composed chiefly of 

friable gray, white, and drab sandstones anfl marly limestones, for the most part horizontal 

but in places uplifted at low angles. At the northwest boundary of the Salt Lake Basin, near 

the one hundred and fourteenth meridian, at latitude 40°, are further exposures of horizontal 

Pliocene rocks, which rise to altitudes of 1,000 to 1,800 feet above the level of the basin. 

K 13-14. NORTHERN GREAT PLAINS, WYOMING, NEBRASKA, AND SOUTH DAKOTA. 

The lower Miocene of the northern Great Plains in the United States is the 

Arikaree formation, including locally the sediments to which the names Gering, 

Monroe Creek, and Harrison have been applied. 623k The Arikaree rests on the 

Brule clay (Oligocene), in some places unconformably, and is unconformably overlain by the later Miocene Ogalalla formation. 

Darton 234' 

235 originally described the Gering as a distinct formation, rather than 

as part of the Arikaree. The deposit is locally developed and consists of coarse sands 

and soft sandstones which contrast with the finer sediments of the Arikaree. It is 

now 238c interpreted as a river deposit laid down in the channels of early and possibly 

somewhat later Miocene streams. Osborn 6231 says: 

The typical Gering formation of Darton, 1899, is at Scotts Bluff, western Kebraska; the 

broad extension by Darton of thi.s formation to other localities is somewhat doubtful. The name· 

Gering formation as used by Darton, Hatcher, and Peterson probably applies to noncontinuous 

river sandstones and conglomerates (maximum 200 feet), which are in a manner analogous to 

the "Titanotherium," "Metamynodon," and "Protoceras sandstones" that traverse the lower 

Arikaree clays or finer beds and partly erode irregular channels in the upper Brule clay (Leptauchenia zone). This formation is thus probably of the same age as the lower parts of the Arikaree, 

~fonroe Creek, and Rosebud. Its known fauna is very limited. The so-called Gering of, Hatcher 

and Peterson i~ in southeastern Wyoming and northwestern Nebr·lska; in their section it is said 

to be lithologically similar to the overlying Monroe Creek. 

The typical Arikaree formation of Darton, 1899, is at Pine Ridge Bluffs, in South Dakota;. 

whether or not this extends to southeastern Wyoming rests on future paleontological correlation. 

The Arikaree as described and mapped by Darton would broadly include the whole of the 

Rosebud formation of Matthew, as well as the Monroe Creek and Harrison, and broadly cover the 

whole of the Miocene. The entire Arikaree formation of Darton consists of finer matenals 

whitish or light-buff sandstones, more continuous and widespread, lying either on the Gerin~ 

formation or on the Brule clay. · 
822 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Appro;cimate correlations of the Arilcareeformation. 

Westerly section, ~outheastern \Vyoming I Easterly section, South Dakota, Porcupine 

and northwestern ~ehraska. Hatcher, Creek. Matthew, Gidley, 1904; Mat1902; Peterson, J flOG. ' thew, Thomson, l90G. 

Feet. Feet. 

rppcr (livision. _ ........... _ Upper part of Harrison ...... _____ . 200 

!

Lower part of Harrison._. ______ .. __ 200 

Upper part of Rosebud ..... ________ a 250 

LowPr division. ______ . ___ .___ Uppe-r part of Monroe Creek- ___ : ___ 300 

Lower part of Monroe Creek ( Germg of Jiatcher and Peterson) ________ 200 

Upper part of Brule clay, or Leptau- chema zone_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 150 

a Estimated_ 

)Lower part of Rosebud. ___________ a 250 

Upper part of Brule clay. or Leptauchenia zone. 

Darton238 d described the Arikaree and Ogalalla as follows: 

A large portion of the higher lands of western Nebraska and southeast Wyoming extending 

south from Pine Ridge is capped by sands and soft sandstones which have been designated the 

"Arikaree formation." It is the principal component of the series formerly termed "Loup 

Fork." Generally it lies unconformably on the Brule clay but overlaps the margins of that formation in some portions of the area. It attains a thickness of over 800 feet in southeast Wyoming 

and, judging from the occurrence of outliers, formerly extended far up the slopes of the mountains 

to the north and west. 

The predominant material is sand loosely cemented into a soft sandstone. The colors vary 

from white to light gray. Characteristic, partly calcareous concretions occur throughout the 

formation and greatly predominate in its lower members. They are mostly of elongate 

cylindrical form, usually occurring in layers connected to a greater or less extent into irregular 

sheets. * * * From observations by Profs. Barbour and Fisher it has been found that these 

concretions are due to the growth of calcite crystals in certain portions and layers of the sandstone. 

* * * * * * * * * 

In studying the geology of North Platte Valley in west Nebraska it was discovered that the 

Arikaree deposits were overlain unconformably by deposits of sand, gravel, and calcareous 

grits, which, on being traced south, were found to be the north extension of the Tertiary grit 

and mortar beds of the Kansas and east Colorado region. They were given the local designation 

Ogalalla formation. 

* * * * * * * * * 

The materials of the Ogalalla formation are mainly sands, merging into gravels, and gravelly 

sands more or less cemented by carbonate of lime into a grit rock which often has the appearance 

of rough mortar, from which the name "mortar beds" is derived. Sometimes the lime rock 

contains but little sand, and usually it varies from grit to conglomerate or conglomeratic grit. 

The original descriptions of the Monroe Creek and Harrison are by Hatcher, 413 

as follows: 

Returning to the Arikaree formation, I have already remarked that in Sioux County, 

Nebr., and Converse County, Wyo., it is lithologically and faunally divisible into two easily 

distinguishable horizons. Commencing below, these may be named and characterized as 

follows: 

1. The Monroe Greek: beds.-These are well shown in the northern face of Pine Ridge, at 

the mouth of the Monroe Creek canyon, 5 miles north of Harrison, Nebr., where they overlie the 

Gering sandstones and are composed of some 300 feet of very light-colored, fine-grained, not 

very hard, but firm and massive sandstones. On account of their usually barren nature they 

have been neglected by collectors, and very little is known concerning their fauna beyond the 

fact that toward the top they contain Promerycochcerus. They decrease in thickness very 

rapidly to the eastward and increase to the westward. 
LATER TERTIARY (MIOCENE AND PLIOCENE). 823 

2. The Harrison beds.-These are well sho~wn in the bluffs of all the small streams that head 

near the summit of Pine Ridge, in the vicinity of Harrison, Nebr. They are also known to cover 

a considerable area to the east, west, and south of that village, extending well into the State of 

Wyoming. They are composed of about 200 feet of fine-grained, rather incoherent sandstones, 

permeated by great numbers of siliceous tubes arranged vertically rather than horizontally. 

They are further characterized by the presence, often in the greatest abundance, of those 

peculiar and interesting but as yet not well understood fossils known as Dremonelix, and by a 

considerable variety of fossil mammals belonging to characteristic Miocene genera. They 

immediately and conformably overlie the Monroe Creek beds and pass insensibly into them. 

Osborn 623m distinguished the upper Miocene, comprising the Procamelus zone, 

and the "latest Miocene or first phase of the Pliocene," the Peraceras zone. He 

gave an extended homotaxis and synonymy. 

K 18. LONG ISLAND. 

Veatch 837 b mentions a possible occurrence of Miocene strata on Long Island as 

follows: 

In the Long Island region and in the New Jersey region the Miocene sediments were 

deposited under similar conditions, and as these two areas have been subjected to the same 

forces, except glacial action, their distribution in both should be similar. The only bed thus 

far seen on Long Jsland which is regarded as possibly Miocene is a thin bed of "fluffy sand" 

which Mr. G. N. Knapp recognized in the upper part of the Melville section, and which is the 

counterpart of certain sands occurring in the Miocene of New Jersey. A comparison of the 

sections indicates that if this structure is normal, and there is every reason to believe it is, a 

Miocene outlier should be expected at this point. The same evidence shows the absence of the 

Miocene above sea level on southern Long Island, except possibly along a portion of the South 

Fluke. This line of argument is important, for it shows that the Tertiary deposits can not be 

expected on the north shore any more than in the Hightstown Vale in New Jersey, and that 

the occurrences on Long Island are probably limited to erosion outliers, with the embed beneath 

the Atlantic. 

K 19. MARTHAS VINEYARD AND NANTUCKET. 

Dall 209a carefully examined the meager occurrences (too small to appear on 

the map) of Miocene strata on the islands of Marthas Vineyard and Nantucket and 

the collections which had been made from them and reported lists of species upon 

which he comments as follows: 

It will be observed that this is a distinctly northern assemblage; any of the species might 

be at home in the waters about Gay Head to-day, as far as we can judge by analogy in the case 

of extinct species. 

As regards correlation with the divisions of the southern Miocene it may be said (1) that 

the Gay Head Miocene is Chesapeake and not older; and (2) that it belongs in all probability 

to the upper part of the Chesapeake, certainly not lower than the St. Marys fauna, and probably between that and the Yorktown beds. 

For a description of the strata see Chapter XV (pp. 682-683). 

In regard to the Pliocene, Dall says that a small collection of shells (for list 

see the work cited) taken from a "layer of sand unconformably overlying the 

Miocene" appears to belong to a "more recent fauna than the Miocene and may 

perhaps be regarded as Pliocene." 
824 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

K-L 11. SNAKE RIVER BASIN, OREGON AND IDAHO. 

The Payette formation of the Snake River valley is described by Lindgren 537 

as follows: 

During the earlier part of the Neocene (Miocene) a large fresh-water lake occupied at 

least the lower part of the Snake River valley, and its sediments are now prominent features 

of the region. For these lake beds the name Payette formation is proposed, and their age is 

determined as upper Miocene. 

* * * * * * * * * 

It extends over large areas to the north of the Payette, along the flood plains of the Snake 

River, and is seen to occupy vast areas in Oregon between the mouth of the Owyhee River 

and Weiser, where the Snake River canyon begins. On both sides of the lower Snake River 

the bluffs of the Payette formation attain a height of over 800 feet. In the Payette Valley 

south of Emmett the sharply defined bluff of Payette beds rises 600 feet above the alluvium. 

Smaller masses, detached by erosion or uplifts, lie in the intermontane valleys, as far east as 

the Idaho Basin. 

Along the Boise Mountains the Payette beds rest against the irregularly eroded and sharply 

sloping surface of the granite, and the top stratum attains a height of 4,100 feet. A total 

thickness of 1,000 feet is exposed near Boise, and wells bored show several hundred feet of 

similar strata below the surface. Over the larger part of its extent the formation lies nearly 

horizontal or dips only a few degrees. Near the mountains dips of 8° to 10°, gener~lly westward, are noted, and the smaller detached masses in the intermontane valleys are still more 

disturbed, generally dipping westward at angles up to 50°. 

* * * * * * * * * 

As might be expected from the character of the land mass from which the sediments were 

obtained, the laLter consist chiefly of granitic, light-colored sands, locally cemented by hotspring deposits to hard sandstones or clayey semiconsolidated sandstones. Heavy masses of 

conglomerates and gravels begin to appear at Table Mountain and reach their greatest development opposite the mouth of Boise River, in the high ridge extending in a westerly direction. 

Purely clayey deposits are rarer, occurring only in convenient sheltered locations near the 

shore line or in places where volcanic eruptions took place. The basal part of the formation 

contains, at Horseshoe Bend, Jerusalem, and other localities along the Payette, small coal 

seams. In the clay accompanying these coal seams vegetable remains are of frequent occurrence. The following forms were identified by Prof. Knowlton: 

Sequoia angustifolia? Lx. 

Quercus consimilis Newb. 

Quercus simplex Newb. 

Acer trilobatum productum? Heer. 

Salix angusta Al. Br. 

Platanus aspira? Newb. 

Ficus ungeri Lx. 

Ulmus speciosa Newb. 

Betula angustifolia N ewb. 

* * * * * * * * * 

From these data Prof. Knowlton draws the conclusion that the age is Upper Miocene, 

. contemporaneous with the flora of the auriferous gravels and the lone formation of California, 

the Lamar flora of the Yellowstone National Park, and the John Day formation of Oregon. 

The paleobotanical evidence confirms the conclusion, confidently drawn from the field work, 

that all these smaller detached masses of lake beds are of practically the same age. 

During the time of the maximum extension of the Payette Lake its surface stood at the 

present elevation of 4,200 feet. Its deposits, over 1,000 feet thick near the shore, rested against 

the abrupt slope of the Boise Mountains and filled the old canyon of the Boise to the same 

depth. The canyon must have formed a fiord, the branches of which reached as far back as 

the Idaho Basin, and in which vast quantities of gravel and sand accumulated. Isolated 

occurrences of well-washed gravel on the summit of high ridges in the lower Moore Creek 

· drainage, at elevations of 4,500 feet, confirm the above conclusions. The data are not at 
LATER TERTIARY (MIOCENE AND ~LIOCENE). 825 

present sufficient to determine the extent of the Payette Lake, though it is probable that it 

was confined to the Snake River valley, inclosed on the west by the Blue Mountains and on the 

east by the divide toward the Salmon River. 

In a subsequent study Lindgren extended the observations on the Payette 

(Eocene~) and uverlying Idaho (Pliocene) formation in the Snake Canyon region. 

Details of occurrence and notes on the fauna by Dall and flora by Knowlton are 

given in his report. 539 

Russell 686 gives the following sketch of the Payette formation in Oregon: 

The Payette formation, which consists principally of unconsolidated sands, clays, gravel, 

etc., together with important beds of light-colored and frequently white volcanic dust, and 

which is widely exposed in southwest Idaho, extends westward into Malheur County, Oreg., 

where it forms a large portion of the surface. This formation was crossed during my reconnaissance in 1902 and again in 19031 but its entire extent in Malheur County can not as yet be 

stated. It occupies the Snake River valley, from near Owyhee northward beyond Ontario, 

and extends westward to a locality about 30 miles southwest of Vale. Similar beds occur also 

along the courses of Jordan and Succor creeks and in several other valleys. As exploration 

progresses it will probably be found that many of the valleys of Malheur County are floored 

to a depth of several hundred feet with soft unconsolidated deposits like those of the Payette 

formation and probab1y of the same or of approximately the same age. Whether all of these 

deposits are portions of one continuous formation, or were laid down in separate and contiguous 

basins, is not as yet determined. It is probable, however, that they were accumulated in much 

the same manner that beds of like character are now being spread out on the surface of the 

valleys of the same region by existing streams. In most of the sediments referred to as being 

analogous to the Payette formation, however, volcanic dust added materially to the depth of 

the deposits. 

L 10. COAST RANGE OF OREGON. 

Diller 273a says: 

I 

The Miocene is widely distributed in western Oregon on both sides of the Coast Range. 

It occurs over a large part of the Willamette Valley * * * and on the coast more or less 

continuously from Astoria to Coos Bay, and most likely beyond, with interruptions, to Califorr~:a. 

Descriptions of local observations and identifications of fossils by Dall follow 

this general statement. A type section of the Miocene is exposed near Empire City, 

Oreg., from which the Empire formation takes its name. Diller 275 states that the 

Empire formation consists chiefly of sandstones and dark shales below with white 

shales above, in all not more than 500 feet thick at the type locality. 

Dall 11 classifies the Empire formation in relation to the Astoria group as 

follows: 

Empire beds.-From typical exposures near Empire City, Coos Bay, Oregon. * * * 

These beds are well exposed between Pigeon Point and Fossil Point, 3 miles southwest of Empire 

City, and abut unconformably upon the Oligocene beds at Coos Head and the Eocene at Marshfield, in the same region. At Fossil Point they are overlain by the richly fossiliferous Pleistocene 

beds of the Coos conglomerate. So far as can be judged from the fauna collected, the Empire 

beds are the exact equivalent of the upper part of the Miocene beds at Astoria, called by Dall, 

in 1892, the Astoria sandstones, to distinguish them from the (Oligocene~) Astoria shales 

(formerly called Miocene), which conformably underlie them. The exact place of the Astoria 

shales in the column must await a better knowledge of the fauna. If the double use of the name 
826 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

Astoria in this manner is regarded as objectionable, the name Empire beds might be taken for 

the sandstones. 

Dall 213 has made an elaborate report on the fauna, with a discussion of the 

stratigraphy and the history of investigation of the Empire formation, particularly 

at Astoria. 

L 10. C.ASCADE RANGE AND YAKIMA VALLEY, WASHINGTON. 

The Miocene of the Cascade Range and Yakima Valley includes both sedimentary and igneous rocks, but the sediments consist largely of volcanic material. 

In order of age from older to younger the formations are the Taneum andesite, 

Yakima basalt, Guye formation (probably contemporaneous with the basalts), 

Keechelus andesitic series and Ellensburg formation. The following notes are 

condensed from the accounts by George Otis Smith: 755• 758 

The Guye formation consists of dark shale and gray sandstone, with some chert and limestone. It is interbedded with basalts and rhyolites. The formation is represented in a very 

small area near Snoqualmie Pass, in the Cascade Range, where it is sharply folded and has been 

intruded by granodiorite. The black shale contains PlaJtanus dissecta Lesq., Acer requidentatum 

Lesq., Ficus n. sp. cf. F. artocarpoides Lesq., and Cinnamomum n. sp., which are assigned by 

Knowlton to the Miocene. 

The Ellensburg formation occurs extensively in theY akima Valley. It is composed largely 

of volcanic sediments, occasionally but rarely containing pebbles of the underlying basalt. 

The greater part of the conglomerate bed is composed of peblbles of light-gray and purple hornblende andesite and of white pumice of the same composition, while the sandstones and shales 

consist of finely comminuted andesitic material. The composition of the conglomerate beds 

and the prevalence of stream bedding indicate that the formation is of fluviatile rather than 

lacustrine origin. The original thickness <;an not be stated. Individual sections show 1,200 

to 1,600 feet in localities where it is evident that the upper part has been removed. The Ellensburg formation carries a flora in which 15 specimens have been identified. Of these 12 or 13 

are reported by Knowlton as occurring also in the Mascall beds of the John Day Basin, which 

are regarded as being upper Miocene. 

L 10-11. JOHN DAY BASIN, OREGON, AND COLUMBIA PLATEAU. 

Merriam 590c describes the strata of the John Day Basin as follows: 

Resting upon the Clarno formation and extending over the greater portion of the John 

Day Basin is a thick s~ries of sediments which Marsh a called the deposits of the "John Day 

Lake." It has generally been referred to in geological and paleontological literature as the 

John Day beds. King b correlates this series with his Truckee beds as a part of the deposit 

of his Pah Ute Lake. In the statement regarding this correlation, King has, however, recognized 

Marsh's name, so that, if a correlation is attempted, Pah Ute should be displaced by John Day. 

Nearl:r the whole of the John Day formation consists of ashy or tuffaceous materials. Only 

toward the top of the section do we find typical products of erosion. At Haystack, Spray, 

and in the lower end of Turtle Cove, good exposures show the highest portion of the series to be 

composed of 100 or 200 feet of hard, blocky tuff, below which is about the same thickness of 

sand and gravel. The gravels are in ·some places quite coarse, containing pebbles 4 or 5 inches 

in diameter. The sands sometimes show cross--bedding. Included in these deposits are worn 

a Marsh, 0. C., Am. Jour. Sci., 2d ser., vol. 9, 1875, p. 52. 

b King, Clarence, U. S. Geol. Expl. 40th Par., vol. 1, p. 458. 
LATER TERTIARY (MIOCENE AND PLIOCENE). 827 

fragments of bones and teeth, which probably represent forms similar to those in the beds 

immediately below. 

Rhyolite flows are found toward the lower part of the Middle John Day at Bridge Creek, 

ncar the top of this division in Turtle Cove, and overlying what is probably Middle John Day 

on Pine Creek, about 3 miles northwest of Spanish Gulch. 

The tuffs and ashes seem in some cases to have been worked over somewhat by air or water. 

At other points beds many feet thick have apparently been deposited directly, without mueh if 

any working over by either wind or water. 

The source of the ash and tuff is as yet unknown. It probably carne from vents not very 

distant from this basin of deposition. 

Excepting the beds of sand and gravel near the top of the section. the stratification throughout the whole thickness of the John Day is very regular. Numerous beds of almost pure ash 

or tuff compose uniform, hard, and prominent layers, between which in the softer beds the 

regular deposition of thin layers is plainly indicated by delicate variations in color. Nodular 

layers, possibly produced in part by contained organic remains, are not infrequent in some 

localities, and small nodules are usually scattered through a large part of the Middle John Day. 

* * * * * * * * * 

Without having accurately measured the John Day section, the writer would not be willing 

to consider the exposures north of the southern range of mountains as representing a thickness 

much greater than 2,000 feet. Perhaps it is not more than 1,500 feet thick. At Sheep Rock, 

near Picture Gorge, the whole section is shown rather sharply tilted, and all but the lower 

division would be included in the column between the cap l'ock and the level of the river. At 

Bridge Creek, also, the section includes the whole of the series. It may reach a thickness somewhat over 2,000 feet at that locality. 

* * * * * * * * * 

Wherever the John Day is well exposed in the central and western portion of the basin, 

it seems to be divisible into three stages, which have been designated a the Lower, Middle, and 

Upper John Day. 

The lower division consists usually of highly colored shale, which breaks down readily, 

forming characteristic mud-covered domes. These beds are in the main a deep red, with 

occasional alternating strata of buff or white ash. At Bridge Creek alternating beds of red, 

white, and green, occurring in a group of the typical hills of this division, form a striking feature 

of the landscape, the colored strata making sharply defined rings about the hills. At Clarno's 

Ferry numerous alternations of contorted and faulted red and white beds arc splendidly exposed 

in prominent hills at the bottom of the section. 

The beds of this group appear usually to show more deformation than those higher up in 

the series .. This may be due in part to their being softer and having offered less resistance to 

disturbances than tho more rigid strata above them. 

The Lower John Day is almost barren of fossil remains at all points where it was visited 

and has never, so far as can be discovered, furnished many good specimens. Diligent search 

by the writer at several localities has been rewarded by the discovery of two or three fragments 

of rhinoceros teeth. An Oreodon skull was found at this horizon, many years ago, by Mr. L. S. 

Davis, but definite information regarding it is not now obtainable. 

The lower division was estimated to be 250 to 300 feet thick at Clarno's Ferry. Its maximum thickness will probably exceed that limit. It is not impossibl~ that the Lower John Day 

will some time be found to be separated by an unconformity from the middle division. Such 

fossil remains as have so far been found in it indicate, however, that it belongs to the John Day 

senes. 

The middle portion of the John Day section at Bridge Creek, Clarno's Ferry, and Turtle 

Cove consists of drab to bluish-green beds, sometimes forming rounded hills but more frequently 

a Merriam, J. C., Science, new ser., vol. 11, Feb., 1900, p. 219. 
828 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

exposed as steep, pinnacled, and ribbed bluffs. Nodular layers and thick beds with small 

nodules scattered through them are common in this group, while they are rare, if not entirely 

absent, in the lower division and are not common in the uppermost beds. The strata of this 

group are never so sharply contorted as those of the lower division, though they may stand at 

a fairly high angle and may show considerable faulting. 

This stage has probably furnished more fossil remains than the upper division, partly 

because the remains are here frequently found in hard nodules, which have protected the bones 

and held them together. 

At Bridge Creek a rhyolite flow is interbedded with the lower part of the Middle John Day 

or possibly separates it from the lower division. In Turtle Cove a similar flow is found at the 

top of this division and possibly separates it from the upper group. At many places, particularly in Turtle Cove, hard beds of white to greenish ash and tuff are intercalated between the 

softer and usually more fossiliferous strata. 

The middle division is at least 500 feet thick in Turtle Cove and possibly as much as 800 

to 1,000 feet at Bridge Creek. 

At most John Day localities, including Bridge Creek, Turtle Cove, and the entire region of 

the North Fork, the uppermost beds in the section are buff tuffaceous or ashy deposits, sometimes with sand and gravels near the top. These beds show a thickness of at least 300 to 400 

feet and perhaps much more in some localities. 

* * * * * * * * * 

This division contains the only typical sands and gravels in the John Day, and the only 

known remains of fresh-water Mollusca occur here. Excepting a single leaf, the only plant 

remains known to occur in the series are in the upper division. 

While it has not been possible for the writer to draw sharp lines between the divisions 

discussed, the lithologic characters are in general sufficiently well marked so that one is enabled 

to determine the horizon in the series to which beds in question belong. 

* * * * * * * * * 

The John Day beds are usually slightly disturbed. They are generally tilted 5° to 10°. 

From the observations made by the writer, no definite system of folds could be made out, 

though there seem to be several which trend east and west. Faulting is not uncommon and 

in some places there has been much friction along the fault planes, so that the soft beds have 

been changed into hard slate bands several inches in thickness. Both the normal and reverse 

types of faults are represented. Toward the west end of Haystack Valley a break of unknown 

extent brings what are probably Middle John Day strata up to the level of the highest beds of 

the series. At another locality, some miles east of this point, numerous thrusts are beautifully 

shown in cliff sections. Along the North Fork two systems of fractures were noticed. One 

trends north and south and the other appears to cross it at nearly a right angle. 

As has already been indicated, the series is evidently unconformable upon the Clarno. 

In the whole of the region occupied by John Day north of the southern range of the Blue 

Mountains, it is covered by the Columbian lavas, being accessible only in the deep canyons, 

where it has been exposed by extensive stream corrasion. At every locality in the basin where 

the series can be seen, its relations to the overlying formations are beautifully shown. In 

several places, notably at Sheep Rock in the upper end of Turtle Cove, and on the main river 

below Spray, residual hills in the middle of the valley are capped by portions of the lower flows, 

which have served to protect the softer beds beneath. 

The Columbia lavas are in some places' seen to be decidedly nonconformable to the John 

Day. Near Haystack the fossil beds form a fairly sharp anticline below lavas which are almost 

horizontal. At Clarno's Ferry lava .ijows are seen at one locality to rest upon the middle beds, 

the typical upper divisions being absent. 
LATER TERTIARY (MIOCENE AND PLIOCENE). 829 

The strata thus described are tabulated by Merriam and Sinclair 591 as follows: 

Stratigraphic succession of the Cenozoic formations in the John Day Basin. 

--------------,---------------------------------

Age. Section jn the John Day Basin. Correia ti ves. 

------- ·--------- ----------------------------1--------------------------------

Terrace deposits with Equus and Elephas remains. Later half of Quaternary. 

Quaternary. 

Erosion interval (tilting of the Rattlesnake and 

erosion of John Day Canyon). · Sierran (?). 

Pliocene. 

Rattlesnake. formation (tuffs, gravels., ashy soil, I 

and rhyolitic lavas). _ Not determined. 

Miocene. 

Unconformity (tilting and erosion of the Mascall). 

----------------------------1 

La t e r :Mascall formation (tuffs, ashes, and possible gravMiocene. els). 

Columbia lava (basalt and interstratified basaltic 

tuffs). 

Pawnee Creek beds, Colorado; Deep 

River beds, Montana; Ellensburg formation, Washington.a 

Yakima basalt, Ellensburg 

Washington. 

Harrison formation. 

quadrangle, 

Earlier 

Miocene. - Monroe Creek formation. 

Oligocene. 

Unconformity. Slight folding of the John Day. 

Interval of erosion. 

-------c----- -----·---------------------1 

Upper John Day (mainly buff-tinted 

tuffs; sands and gravels near top). 

John Day : Middle John Day (drab and bluishseries. green tuffs). 

---- ------------------

Lower John Day (red, white, .and green 

tuffaceous shales). 

lT nconfo•·mity---l----------'----------------,-----------------1 

Clarno formation (shales, I 

Eocene. 

tuffs, andesitic and rhyo- I 

litic lavati). The Clarno 

has yielded an abundant 

flora, but no vertebrate 

remains have yet been 

found. 

Upper Clarno beds 

(upper Eocene). 

Lower Clarno beds 

(lower Eocene). 

Rosebud formation. 

Payette formation, Idaho.b 

Manastash formation, Washington. c 

Unconformity--- --------------------~-'------------------1---------------------------------

Cretaceous (marine). Chico formation (sandstones and conglomerates). 

Basal Chico at Texas Springs and near Horsetown, Cal.; Phoenix beds at '49 

mines, Oregon.d 

- ·--- - -------- ----------------

a Knowlton, F. H., Fossil flora of the John Day Basin: Bull. U.S. Geol. Survey No. 204, 1902, pp. 109-110. b Idem, pp. 110-111. c Smith, G. 0., Prof. Paper U.S. Geol. Survey No. 19, p. 16. 

d Stanton, T. W., note in Bull. Dept. Geology Univ. California, vol. 2, p. 294. 

Osborn 623i gives the following resume of the Oregon Tertiary as a whole: 

The known mammal fauna of Oregon, as determined partly by Cope and Wortman. and 

more precisely as to levels by Merriam and Sinclair, is found on five levels, partly separated by 

volcanic overflows, as follows: 

Rattlesnake 

Mas call 

Upper part of John Day 

Middle (fossils numerous) and (?) lower parts of 

John Day. 

=upper Miocene 

=middle Miocene 

=transition, upper Oligocene, 

lower Miocene 

=upper Oligocene, second phase 

=Procamelus zone. 

=Merychippus zone. 

=Promerycochmrus zone. 

=Diseratherium zone. 
830 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The time of the beginning of the John Day deposition appears to correspond with that ·of 

the close of the Leptauchenia zone in the South Dakota region, namely, the upper Oligocene. 

* * * * * * * * * 

The volcanic materials of the John Day were chiefly wind blown, as described by Merriam;a 

there is little evidence of fluviatile conditions. The Mollusca are terrestrial or air breathing, 

with the exception of one locality which contains fluviatile Mollusca. The Testudinata, genus 

Stylemys, are of the Testudo or terrestrial type; no fluviatile types have been recorded. The 

so-called beavers (Castoridre) are not the true river-living beavers (Peterson). 

The known fauna of the John Day formation as a whole is chiefly of open-forest and 

savanna-living type. We note the entire disappearance of the ancient fauna, CreodontaHyrenodontidre, and do not observe the introduction or invasion from Eurasia of any new 

families of mammals. The major part of the John Day fauna is of upper Oligocene age, but in 

its latest phases it is perhaps transitional to lower Miocene. The fauna is thus broadly transitional between that of the White River group and the Arikaree formation. 

* * * * * * * * * 

The lower John Day fauna is so little known that no deductions can be made from it, 

except that it appears to be closely related to that of the middle John Day. The faunistic 

comparison of the John Day formation therefore begins with the middle John Day, which is 

highly fossiliferous and slightly more advanced than that of the upper portion of the Brule clay 

and ''Protoceras sandstones." 

* * * * * * * * * 

The conclusion is that the middle John Day deposition partly overlaps and is partly sequent 

to the deposition of the upper part of the Brule clay and the ''Protoceras sandstones." 

* * * * * * * * * 

The upper part of the John Day formation, or Promerycochmrus zone, of the Mountain 

region of Oregon, as well as the Gering and Monroe Creek formation of Hatcher, the Gering or 

lower Arikaree of Darton, the Rosebud of Matthew, all in the plains region of South Dakota, 

may be regarded as covering the transition between the Oligocene and Miocene epochs, as these 

divisions are employed in France. They resemble chiefly the upper Oligocene of France. 

* * * * * * * * * 

It is concluded that the upper part of the John Day, for the present, may be somewhat 

arbitrarily separated as the American upper Oligocene, while the partly contemporaneous and 

partly sequent plains formations may be termed lower Miocene. 

The Columbia River basalt (Miocene) is the dominant formation of the Columbia Plateau. Overlying it in Washington are the strata described by Russell "

84• 

685 

as lake beds and assigned by him to the John Day formation, but apparently of 

later age. Russell states in his later report: 685 

In my report of a reconnaissance in central Washington certain lacustral deposits are 

described which rest on the surface of the latest extensive lava flow of the Columbia system. 

This series of lake sediments consists principally of stratified clays, with thick strata of white 

volcanic dust, and in certain localities contains beds of coarse conglomerate. It is termed the 

John Day system, for the reason that it is thought to be an extension of a similar formation 

which occurs in John Day Valley, Oregon. The connection between these two areas has not 

been actually traced, however, and the correlation just suggested must be considered as 

provisional. 

Beds of light-colored clay and of white volcanic dust, which have been referred to the John 

Day system, occur at the White Bluffs of the Columbia, 30 miles above Pasco, and are also well 

exposed in Naches Valley and near Ellensburg, in Yakima County. At these localities the 

impressions of the leaves of a large variety of plants and the bones of extinct animals have been 

obtained. The plant remains indicate that the shores of the ancient lake into which they were -----··----

a A contribution to the geology of the John Day Basin: Bull. Dept. Geology l:niv. California, vol. 2, 1901, pp. 

269-314. 
LATER TERTIARY (MIOCENE AND PLIOCENE). 831 

blown or washed by tributary streams were clothed in a vaJ.:ied and beautiful flora, resembling, 

in a general way at least, the vegetation of the South Atlantic and Gulf States at the present 

day. In the ancient forest and about the shores of the old lake, now known as Lake John Day, 

a veritable menagerie of strange and in part gigantic beasts found a congenial home. 

From the White Bluffs of the Columbia southward to the region described in this report 

there are no barriers, but the surface of the country rises gradually from the broad valley of 

the Columbia to the basaltic plateau of northeastern Washington. From studies made along 

the Columbia in 1892, I was led to the conclusion that Lake John Day extended far eastward 

and covered nearly all of southeastern ·vvashington, even to the base of the Blue Mountains. 

This view is now known to have been in part erroneous. The sediments of Lake John Day are 

but poorly exposed to the east of Pasco and Wallula, and their extent in that direction, although 

not clearly shown, is certainly far short of the Blue ~fountains and of the Idaho boundary. They 

cover the Eureka Flats, however, as is shown by a well198 feet deep at Eureka Junction, which 

is all in strata similar to those exposed in the White Bluffs of the Columbia but does not reach 

the bottom of the formation. Fossil leaves were found in the rock removed in digging the well, 

similar to those obtained from other portions of the John Day system. ·with the exception of 

the rocks found at Eureka Junction, no exposures of the Lake John Day system have been 

recognized in the region treated in this report. The sediment of the old lake does not occur 

above the Columbia lava in the vicinity of vValla Walla, Dayton, and Starbuck1 and its eastern 

shore must have been to the west of these localities. 

The lacustral deposits described in the preceding section as being interbedded with the 

Columbia lava are of about the same age as the John Day system and were accumulated under 

similar conditions. They should perhaps be included in the same system, but further study 

is necessary before a conclusion in this connection can be reached. 

Knowlton made a report on plants collected by Russell from an outcrop near 

Ellensburg, later placed in the Ellensburg formation by George Otis Smith. (See p. 

826.) Regarding the correlation Knowlton 684a concluded: 

The leaves from near Ellensburg, Wash., are preserved in a moderately soft white chalky 

matrix, that is in general very similar to the well-known material from the auriferous gravels 

of California and the John Day Valley in Oregon. * * * 

Of the ten species enumerated [for list see the work cited], seven, among which are the species 

most abundant in specimens and the most positive in identification, have been found in the 

auriferous gravels of Californiu. Seven of the species have also been reported from the ,John 

Day Valley, Oregon, of which number three are common to the auriferous gravels. The new 

species (Populus russelli) has great aflinities with Upper Miocene species of Europe. 

From this examination it appears that there can be no doubt but that the plants from 

Ellensburg are similar in age to the auriferous gravels and the John Day Valley. The John Day 

Valley deposit has always been called Miocene. The auriferous gravels, on the other hand, 

were regarded by Lesquereux and others as Pliocene, but a recent examination of that flora 

based on extensive collections from Independence Hill, Placer County, Cal., seems to indicate 

that they also are probably upper Miocene in age. 

L 12. WESTERN MONTANA. 

Calkins, in an unpublished manuscript, has the fqllowing to say in regard to 

the Tertiary in the Philipsburg quadrangle, 1\Tontana, which applies equally well to 

adjacent areas of these rocks: 

Rocks of Tertiary age apart from the intrusives occupy relatively small areas, chiefly in 

the valleys. The evidence at hand indicates that all these rocks are strongly unconformable. * * * They lie on various older formations indiscriminately, are not metamorphosed 

by the intrusions, and are much less deformed than the Cretaceous and older sediments. The 
832 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

quadrangle does not afford the best opportunity to determine the absolute age of the Tertiary 

formations, nor their relation to one another. * * * 

In Philipsburg Va1ley and Willow Creek valley there are exposures of light-colored silty 

material shown by microscopic examination to be chiefly volcanic ash. These correspond in 

character to beds well exposed near New Chicago, north of the quadrangle, in which Douglass 

has collected vertebrate fossils that indicate a late Miocene age. * * * 

The soft, pale-tinted, obscurely stratified volcanic ash beds, presumably of Miocene age, 

occur (1) at the north boundary of the quadrangle west of Flint Creek, (2) on Willow Creek near 

the west border of the qw_tdrangle, and (3) in Philipsburg Valley with its southern continuation across the east fork of Rock Creek. These beds are perhaps the least resistant to erosion 

and the most poorly exposed in the quadrangle,· being rarely uncovered except on steep slopes 

below the brinks of terraces capped by protecting gravel. Among the better exposures are 

some about 3 miles northwest of Philipsburg, whose whitish tint makes them visible from the 

town, and another.in a gully about 1 mile north of Quinlan"s ranch, at the head of Philipsburg 

Valley. 

L-M 10. OLYMPIC PENINSULA, WASHINGTON. 

The reconnaissance of the coast of the Olympic Peninsula in 1904 by Arnold 290 

led to the recognition of a formation covering parts of Oligocene and Miocene time, 

the Clallam formation. Arnold says: 

Resting unconformably upon the Eocene and older rocks of the Olympic Peninsula is a 

series of conglomerates, sandstones, and shales rich in fossils and extensive in occurrence. The 

formation is well exposed in the region between Clallam Bay and Pillar Point, to the east, 

and for that reason is here named the Clallam formation. According to Dr. Dall, the fossils 

of the formation indicate that the basal portion of the series is Oligocene in age, while the upper 

part is certainly Miocene. Since the separation of the two members will necessarily have to 

be made on paleontologic grounds and will require a more detailed study of the material in hand 

than time has yet permitted, the term "Oligocene-Miocene series" will be used temporarily 

to designate the age of the beds. A portion of the formation is unquestionably the equivalent 

of the Astoria sandstones and shales occurring at the mouth of the Columbia River, 130 miles 

farther south. 

All of the pre-Pleistocene deposits along Fuca Strait from Freshwater Bay to Cape 

Flattery, wjth the exception of the Eocene basalts and tuffs of Crescent Bay and the Pliocene 

conglomerate and sandstone of the Clallam Bay~Hoko River region, be1ong to the OligoceneMiocene series, and at least the greater part and possibly the whole of the thick series of conglomerates, sandstones, and shales exposed in the Cape Flattery promontory, and also the 

sandstones and shales exposed in the hills south of the Bogochiel River, come under the same 

head. The thickness of this series as exposed in sections along the strait, which, by the way, 

virtually parallels the strike of the beds for most of the distance from Freshwater Bay to Neah 

Bay, is about 3,650 feet. The Waatch-Neah Bay section, which cuts directly across the strike 

of the great Cape Flattery monocline, exposes approximat9ly 15,000 feet of conformable strata, 

most and possibly all of which may be Oligocene-Miocene. 

The conglomerates of the series are usually quite coarse and hard and consist of pebbles 

and cobbles of quartzite, jasper, black slate, and occasional granitics. They are found mostly 

at the base and near the top of the series along the straits and in the middle of the series on the 

Cape Flattery promontory. The zone of conglomerate in the middle of the Cape Flattery section may be the equivalent of the basal conglomerates of the series as developed unconformably above the Eocene around Crescent Bay. If so, the sandstones at the base of the Cape 

Flattery section are older than any of the Oligocene-Miocene beds exposed on the strait. The 

base of the Cape Flattery section is unknown, as the lowest beds exposed in the section are 

separated from the subjacent rocks by a fault. 
LATER TERTIARY (MIOCENE AND PLIOCENE). 833 

The sandstones of the Clallam formation are for the most part thin bedded, hard, and 

resistant to erosion and are extremely fossiliferous in certain localities, notably east of Clallam 

Bay. They are found at the base and near the top of the Cape Flattery section and below 

the upper conglomerates east of Clallam Bay. 

The shale of the Oligocene-Miocene occurs principally in the middle of the formation along 

the strait. The lower part of the shale is thinly and plainly laminated, but higher up becomes 

almost massive clay. * * * The overthrusting of the beds exhibited at [one] locality is 

very unusual, as the strata along this portion of the coast ordinarily lie in low simple folds. The 

shale is gray in fresh exposures but becomes more or less oxidized upon exposure. Sandstone 

dikes, probably derived from interbedded sandstones, cut the shales in the region east of the 

mouth of the Pysht River, and near Gettysburg hydrogen sulphide gas was noticed escaping 

from cracks in the shale along the beach. * * * Fossils are abundant and beautifully 

preserved throughout the finer sediments of the series, at least two distinct horizons being 

recognized. 

At least five recognizable faunas have so far been found in the Clallam formation. The 

oldest comes from the lowest clay shales of the series. [For lists see the work cited.] 

Above the clay shale horizon is a series of medium-bedded to fine massive sandstones in 

which are found fauna apparently transitional from the clay shales to the coarse sandstones. 

Still a third fauna [Miocene], later than the last, is represented by species found immediately 

east of Clallam Bay. 

The fourth fauna is that found in sandstone layers interbedded with conglomerates in the 

upper parts of the formation. · 

The fifth fauna of the Oligocene-Miocene is that found at the mouth of the Sekiu River 

in beds the equivalent of the uppermost strata of the Cape Flattery section. The relation of 

this fauna to those [below it] is somewhat problematical, although it appears quite likely 

that the former is younger than most of the latter. 

Correlations between the different fossiliferous localities of the Oligocene-Miocene series 

over the whole of the peninsula and Puget Sound region are comparatively easy, as are also 

correlations with certain of the Oregonian faunas such as those of the Astoria shales and sandstones, but when it comes to making direct correlations with the California or Alaskan faunas 

much difficulty is encountered. One of the greatest surprises the writer had in all of his work 

along the straits was his inability to find the characteristic upper Miocene fauna of the Sooke 

beds which are so well developed only 15 miles to the northward on Vancouver Island. With 

an almost unbroken series of Miocene faunas one would certainly expect to find the Sooke 

species somewhere among the lot, but such was not the case and no plausible explanation of 

their absence has so far presented itself. 

L-M 11-12. LAKE BASINS OF WESTERN MONTANA. 

The valleys which lie within the mountains of western Montana correspond 

throughout much of their extent with basins that are partly filled by sediments 

of Miocene and Pliocene age. The deposits were well described by Peale. 632 They 

were laid down in lakes, in large part at least, and comprise several types of sediment. The lowest are composed of material derived from the shores of the basins, 

from pre-Cambrian or Paleozoic rocks. They are succeeded by beds of volcanic ash, 

in part carried by wind and deposited in the lakes without admixture of foreign 

material, in part washed in from adjacent land surfaces. The sediments were 

locally covered by basalt. Peale's description applies to the Bozeman and Madison 

basins, in which the deposits exceed 2,000 feet in thickness. 

Douglass 287 describes the general distribution of the Tertiary. In a later 

article 288 he distinguished the Sage Creek beds (Eocene~), White River formation 

48011°--12----53 
834 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

(Oligocene), and Fort Logan beds (upper Oligocene, John Day?). (See pp. 775-776.) 

The Miocene he assigned to the "Loup Fork," and recognized three divisionsDeep River beds (upper Deep River of Scott 717), Flint Creek beds, and Madison 

Valley beds. Scott quotes from the first description by Grinnell and Dana (1875). 

(See Chapter XVI, p. 776.) 

M 12-13. CYPRESS HILLS, SOUTHWESTERN SASKATCHEWAN. 

McConnell 558a gives the following notes on the Cypress Hills, in Saskatchewan: 

The most interesting result of the geological examination of the district has been the 

discovery of an extensive area of .Mioeene beds, the first found in Canadian territory east of the 

Rocky Mountains. These beds cap all the more elevated parts of the range of uplands extending 

in a direction a little north of east, from the west end of the Cypress Hills to the east end of 

Swift Current Creek plateau, a distanee of 140 miles. They have an average width of 15 miles, 

and cover altogether an area of nearly 1,400 square miles. They are unconformable to the 

beds below and in their western extension rest on the Laramie, but near East End Coulee they 

overlap it and are then underlain by the Fox Hill and Pierre. They have a general easterly 

dip of about 15 feet per mile, which is somewhat greater than that of the underlying beds, and 

in their eastern part are affeeted to some extent by the same depressed fold whieh has thrown 

the White Mud River Laramie area into a flattened form. 

The Miocene beds arc characterized by the great quantity of watcrworn pebbles, derived 

from the quartzite formations of the Roeky l\fountains, which are found in every part of the 

series. The pebbles are usually cemented together into massive beds of hard conglomerate but 

also occur distributed irregularly through or arranged in layers and lenticular beds in the sands 

and sandstones. The more massive conglomerate beds are found toward the western part of 

the area or around its outskirts. The associated beds, consisting of sands, sandstones, marls, 

and clays, are described in a previous part of the report. They are all very irregular, and 

seldom remain constant in composition for any distance along their strike. 

* * * * * * * * * Under the general name of the South Saskatchewan gravels are included the pebble conglomerates and incoherent gravels and silty beds which are found, as valley or lake deposits, 

in different parts of the district and which, although destitute of organic remains so far as 

examined, are known by their relative position to be intermediate in age between the Miocene 

and Quaternary and to belong mostly to the period immediately preceding the latter. They 

are, however, not all contemporaneous and in one or two places afford evidence, by the admixture of Laurentian and quartzite pebbles toward the top, of a gradual blending with the lowest 

glacial beds. The deposit is usually confined to a single bed of conglomerate, varying in thickness from 2 up to 50 feet, composed of small quartzite pebbles, precisely similar to those found 

in the Miocene, and either consolidated by a calcareous or ferruginous cement, or with its 

constituents lying loose in a sandy matrix. In some places the conglomerate is overlain by a 

considerable thickness of sandy or silty beds. 

Cope's report on the vertebrates 558b is published as an appendix to McConnell's 

report. 

N 8-9. GRAHAM ISLAND, QUEEN CHARLOTTE GROUP. 

The Tertiary sediments of Graham Island are described by Ells 316a as gray 

cross-bedded quartzose grits, having a calcareous cement and holding scattered 

pebbles; gray and black shales in thin beds; conglomerates; and lignites. The age 

of these sediments appears to be Miocene or later but is incorrectly shown as earlier 

Tertiary on the map of North America. (See also tabular view of formations of 

Qneen Charlotte Islands, by G. M. Dawson, Chapter XII, p. 540.) 
LATER TERTIARY (MIOCENE AND PLIOCENE). 835 

N 10. UPPER PEACE AND FRASER RIVERS, BRITISH COLUMBIA. 

Under the title Lignite group Dawson b described the occurrences of sandstone 

and shale which earry lignite beds and commonly underlie the basalt flows of the 

upper Fraser Valley, British Columbia. At Quesnel they have yielded a flora of 

Mioeene or earlier age associated with insects. 

N-0 4. ALASKA PENINSULA. 

Atwood 42c thus describes the Miocene of the Alaskan Peninsula: 

:Miocene sediments appear in Unga and Popof islands and at several p1aces on the north 

and south sides of Alaska Peninsula. They consist of sandstones, shales, and conglomerates 

that re.present off-shore, shallow-water deposition. An abundance of fossil material was procured and has been identified by Mr. Dall. At Coal Harbor, Unga Island, the Miocene strata 

conformably overlie the Kenai formation (upper Eocene), but at other localities the Miocene 

sediments appPar to rest unconformably upon different formations and to have been restricted 

to local basins. They are but little disturbed. 

One collection of fossil plants, from the Herendeen Bay district but from a lithologic unit 

that occupies a VC'ry small area, seems to indicate post-Miocene age. The most extensive postMiocene formations consist of volcanic tuffs and basic lava flows. They are widespread on the 

mainland in the vicinity of the Balboa-Herendccn Bay district and covPr many square miles in 

the islands to tho south and in the region about Chignik Bay . 

.For Kodiak Island and Katmai Bay, see Chapter XVI (p. 784). 

0 4. BRISTOL BAY. 

On the east shore of Nushagak Bay, which enters Bristol Bay from the north, 

Spurr 771 a observed strata to which he gave the name Nushagak. He says: 

The high bluffs which form the cast shore of Nushagak Bay arc composed of stratified 

gravels, coarse sands, arkoses, and clays, which in places are slightly consolidated, apparently 

being cemented by iron which has leached out of the arkoses. These beds, in general horizontal, 

are frequently distinctly flexed, sometimes dipping as much as 20°, and in places there is even 

considerable folding and distortion. The strata are often heavily cross-bedded and contain 

pebbles derived from a great variety of rock, some of which are striated, apparently from ice. 

This formation is exposed for a number of miles along the shore of N ushagak Bay and around 

Cape Etolin to Bristol Bay. 

Overlying the folded clays and gravels which have been called the Nushagak beds are 

unconformable horizontally stratified clays and gravels which contain many pebbles and 

frequently large bowlders, often being striated by ice. Near Nushagak these upper beds occupy 

the tops of the bluffs, which are in places as much as 150 feet high, but where the bluffs become 

lo\ver and the beds themselves become thicker they often come down to the beach line, so that 

the underlying unconformable series is not exposed. These upper beds must be referred to thH 

Pleistocene, so that those which underlie are probably Tertiary. In this connection a note 

made by Dr. Dalla concerning fossils collected at Nushagak by C. W. McKay is of interest. · 

According to this, fossils were collected in an ''indurated clayey matrix," which evidently refers 

to the Nushagak beds just described. They include Modiola multiradiata Gabb, Pectuncul1(8 

patulus Conrad, }lucula tenuis Lamarck, and Serripes gronlandicus Beck and determine the age 

of the clays and gravels in which they occur as Miocene. 

Regarding the above Atwood states in a personal communication: "I have not 

been at this locality. The pebbles and bowlders striated by ice, which are reported ----------------

a Report on coal and lignite of Alaska: Seventeenth Ann. Rept. U.S. Geol. Survey, pt. 1, 1896, p. 847. 
836 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

as common in the Nushagak beds of Spurr, make me doubt their Tertiary age. I 

believe they must be younger." 

0-P 9. DEASE AND UPPER LIARD RIVERS, BRITISH COLUMBIA. 

Dawson/58t in a report on explorations in the Yukon district, describes a wide 

plateau cut on Tertiary rocks, which are unconformable to the underlying Paleozoic 

rocks. 

Q 5-6. YUKON VALLEY. 

Spurr 770a distinguished two occurrences of Tertiary. strata in the Yukon 

Valley-one as the Twelvemile beds and the other as the Palisade conglomerate. 

According to Brooks the former is now regarded as of Kenai (Eocene) age. Concerning the latter Spurr says: 

On the left bank of the Yukon, about 35 miles below the mouth of the Tanana, cliffs of silt 

and gravel rise to a height of 150 feet. This locality has been named the Palisades, but on 

account of the occurrence in the silt of abundant bones of the mammoth and other large animals 

it is more popularly known as the "Boneyard." The silts also contain lignite beds and small 

land and fresh-water shells and are of Pleistocene age. About a mile below the beginning of 

the silt bluffs the height of the vertical exposure changes from 150 to 200 feet, the increase 

being apparently caused by a fault which is visible in the face of the bluffs and which upthrusts 

the down-river portion. The fault is a normal one, and the silts of the upstream side are seen 

to be upturned against the fault plane. On the downstream side of the fault there is brought 

up a lower and more consolidated bed which underlies the silts. This new bed is pure white, 

being composed of clean sand and well-washed pebbles. It is strongly cross-bedded and 

contains much woody matter-sticks, logs, etc.-in a condition between wood and lignite. 

Many of these woody layers are steeply inclined, being cross-bedded with the sandstone. This 

bed is very gently arched and has a barely perceptible dip downstream. It is partly indurated, 

so that while it yields with comparative ease to a pick, it is firm enough to stand in solid, 

nearly perpendicular cliffs and falls in great slabs. 

In the materials collected from the woody layers Dr. Knowlton found fragments of dicotyledons, but none sufficiently distinct for identification. Many of the layers are full of finely 

preserved cones, which, according to Dr. Knowlton, appear to be the same as Heer's Pinus 

macclurii, and from these he infers that the age is Pliocene, or possibly Upper Miocene. 

Q 7. UPPER YUKON. 

Brooks 103 t states: 

No beds have been identified on the Yukon which are positively known to belong to the 

Pliocene or Miocene. It seems probable, however, that some terrace deposits may be of late 

Tertiary age. Such interpretation of the facts in hand has been made by both Spurr and 

Collier. 

McConnell 563 thus describes the occurrence east of the international boundary: 

Beds referred to the Tertiary occur at several points around the outskirts of the gold 

district. A wide band follows the Yukon Valley above Dawson, on the northeast side, and 

continues on in a direction a little south of east to the Klondike, which it crosses a short distance 

above the mouth of Rock Creek. It then follows the Klondike River to the mouth of Flat 

Creek and probably underlies the belt of plateau country that borders the latter and extends 

through to the Stewart. 

Exposures of these beds on Rock Creek and the Klondike River consist mostly of soft 

grayish sandstones, indurated clays and shales, and occasional beds of ironstone. A thick 

lignite seam is reported to outcrop on one of the branches of Rock Creek, and other seams occur 
LATER TERTIARY (MIOCENE AND PLIOCENE). 837 

along the band in its northwesterly extension. A seam, or group of seams, said to be 15 feet 

in thickness, is being worked on Cliff Creek, about 75 miles below Dawson, for the supply of 

that place. 

A small area of dark sandstones, agglomerates, hardened clays, and shales was found on 

Last Chance Creek, a tributary of Hunker Creek, lying at angles on the schists. The sandstones 

contain small particles of carbonaceous matter, but no lignite was noticed. 

Tertiary beds were also found along the southern boundary of the district on Indian River. 

The northern limit of this area follows Indian River Valley from Quartz Creek to a point above 

New Zealand Creek, and the band extends southward beyond the region examined. The beds 

lie in easy folds and consist mainly of soft light-grayish sandstone, dark coarse agglomeratic 

sandstone, soft dark shales, and, at one point, of heavy beds of coarse conglomerate. Fragments of fossil plants occur throughout the formation, but no determinable specimens were 

found. 

Q 8. PEEL RIVER. 

Camsell 128a explored Peel River, a western branch of the Mackenzie which 

joins it at the head of the delta. He says: 

The upper canyon of the Peel River is cut in a series of tilted black slates, often dipping 

upstream. The strata of which it is composed are alternately thick and thin bedded, containing 

concretionary nodules with crystals and veinlets of pyrite and some bituminous matter disseminated through the rocks. This formation extends for a distance of three-quarters of a mile 

below the mouth of the Wind River, where it is replaced and overlain by Tertiary clays and sandstones. The contact is not so well shown on the Peel River as it is on the Wind, though the 

unconformity between the two is plainly evident. These slates outcrop again 15 miles below 

in the lower canyon of the Peel River, so that they border the Tertiary rocks both to the east 

and to the west. A small outcrop of bituminous limestone, overlain by the red clay and sandstone of the Tertiary, is exposed 1 mile below the canyon on the south bank of the river. 

When cut through by the Peel River, the Tertiary basin is 13 miles in width. The rocks 

of this basin consist of thick beds of soft sandstone, with some thin seams of lignite, overlain 

by more sandstone containing pebbles, with clay and some very thick beds of lignite. The whole 

series has been gently folded into a number of anticlines and synclines. One lignite bed near 

the top of the series is 30 feet in thickness and fairly persistent, appearing in two exposures 

4 miles apart with a shallow syncline between. This bed rises in an anticline, the top of which 

has been truncated by later erosion, and beyond it dips again and disappears beneath the bed 

of the Bonnet Plume River. 

Q 9-10. MACKENZIE VALLEY AND BEAR RIVER. 

The" Bear River Tertiary" which outcrops along the :Mackenzie above and below 

Fort Norman is described in some detail by McConnell, 560d who quotes descriptions of the flora by Sir William Dawson.265 The original publications should be 

consulted for details. :McConnell states: 

After reviewing the evidence afforded by the collections of fossil leaves and fruits which 

have been brought out by various explorers and examined by Heer and others, Sir William 

Dawson arrives at the following conclusion: 

"The general conclusion indicated by the above facts is the strong resemblance of the 

flora of the Mackenzie River beds with that of the Laramie of other parts of Canada and the 

United States and also with the Tertiary of Greenland, Spitzbergen, Alaska, and the Hebrides. 

They thus confirm the inferences as to this similarity and as to the Lower Eocene age of the 

Upper Laramie stated by the author in 'The report on the forty-ninth parallel' in 1875, in 

subsequent 'Reports of the Geological Survey,' and in previous volumes of these Transactions." 
838 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

The Be9,r River Tertiary basin, measured along the Mackenzie, has a length of about 40 

miles. Its width was not ascertained, hut Tertiary beds probably underlie the flat country 

which borders Bear River for 20 miles aboYe its mouth. They can not extend more than 15 or 

20 miles in a westerly direction, as a lofty limestone range runs parallel with the river at about 

that distance. The distribution of the beds is thus limited to an area 40 or 50 miles in length 

and 30 or 40 in width and may be considerably less. 

The beds of this Tertiary basin are evidently lacustral in their origin and both in lithological character and stratigraphical position have a much closer resemblance to the Miocene 

(White River) of the Cypress Hills and neighboring areas than to the Laramie, ·with which their 

fossil flora correlates them. Like the Cypress Hills beds, they are characterized by their irregular deposition, by their slight induration, and by the large proportion of gravel and pebble beds 

which they contain, and a further degree of relationship is evidenced by the faet that they both 

rest unconformably on the beds beneath. 

Knowlton, in a personal communication, states that the "Bear River Tertiary" of the Mackenzie Valley is the equivalent of the Fort Union of the United 

States and is lower Eocene. 

R 5-6. ARCTIC COASTAL PLAIN, ALASKA. 

In traversing the Colville Valley Schrader 708b distinguished Oligocene and 

Pliocene strata of the region as the Colville series. For his description of the lower 

Colville (Oligocene) see Chapter XVI (pp. 792-793). In regard to the upper Colville 

(Pliocene) he states: 

This portion of the section is practically free from indurated rock. It consists of nearly 

horizontally stratified beds of fine gray, slate-colored, or ash-colored calcareous silts, containing 

faunal remains. It is tentatively assigned to the Pliocene on the basis of fossils collected in 

place by the writer in the bluff (near its top) on the west side of the Colville about a mile north 

of the seventieth parallel. These have been reported on by Dr. Dall. [List follows.] 

R-U 16-22. ARCTIC ARCHIPELAGO AND WESTERN GREENLAND. 

Dawson 257 b in 1886 wrote of the "Arctic Miocene:" 

The so-called Miocene of Greenland and Grinnell Land is now regarded as equivalent to 

the Laramie, or at least not newer than Eocene, by Mr. J. Starkie Gardiner, Sir William Dawson, and other paleobotanists. Our knowledge of the flora of the Banks Land beds is very 

slight, being confined to that of the structure of a few specimens of fossil woods * * * which 

have been reported on by Dr. C. Cramer, but, so far as it goes, it presents no features incompatible with the possible Laramie age of these deposits also. 

The Tertiary plant-bearing sediments on the west coast of Greenland are 

described by White and Schuchert 902a as conformable to the Cretaceous Patoot 

senes. 

The Patoot series, which appears lithologically and stratigraphically to be inseparable 

from the Atane series, contains at the same time many plants common in the upper part of 

the Amboy clays, with others allied more closely to the higher Cretaceous floras, such as that 

of the Laramie. The Patoot series may perhaps be safely interpreted as constituting a paleontological as well as sedimentary transition from the Atane series to the Tertiary. The thickness 

of the Atane and Patoot series (Senonian) is not less than 1,300 feet and may considerably 

exceed this. 
LATER TERTIARY (MIOCENE AND PLIOCENE). 839 

The Tertiary clastics at Atanikerdluk attain a thickness of not less than 1,500 feet, not 

including the intruded basalts at least 200 feet thick. The horizon of most of the plants 

described by Heer as Mioce!le is assumed to be near the base of that series, the demarcation of 

which appears to be purely arbitrary. a It is more probable that the age of the plants now 

generally conceded by paleobotanists to be Oligocene may even be Eocene instead of Miocene. 

No remains of marine animals have as yet been discovered with these plants. 

The Tertiary clastic zone appears to be thinner west of Atanikerdluk, and at Patoot and 

Atane it is presumably represented by the upper sandstone horizon 200 to 300 feet in thickness. 

At the western end of the peninsula its presence is established in the oecurrenee of "Atanikerdluk" plants. On the north coast east of Niakornat there may be n slight development of this 

z.one, and it evidently is represented in the interior cast of Kook. 

Tertiary strata of unknown position occur in western Ellesmere Land. Schei 707" 

says: 

In the depressions between the mountains of Mesozoic sandstones abutting on Heureka 

Sound are in many plaees thiek deposits of light quartz sand with embedded strata of lignite. 

The same is also the ease in the lowlands east of Blaamanden and at the head of Stenkulfjord 

in Baumann Fjord. In addition to the lignite, masses of slaty clay were also found at the 

latter plaee, in whieh were well-preserved remains of Sequoia langsdorjii, Taxodium distichum 

var. miocenum, and some others, well-known witnesses to a southern vegetation in these regions 

in a geologically late period-that is, the Mioeene. 

Descriptions of the eruptive rocks follow in the original work. 

a The conglomeratic sandAtone at 1,000 feet above tide at Atanikerdluk, assumed by the writers to be the base 

of the Tertiary at that point, is the only hypothetical lithological bench mark observed in any section. 
CHAPTER XVIII. 

BIBLIOGRAPHY. 

The subjoined bibliography comprises the publications cited in the text of 

this work. References included in quotations have been printed with the quotations as footnotes. The references in the bibliography are arranged alphabetically 

by authors' names and under each author in the order of dates of publication. 

'Vhere different pages of a single work are cited letters are used in connection with 

the number that refers to the work. 

1. Adams, F. D., Structure and relations of the Laurentian system in eastern Canada: Quart. Jour. Geol. Soc. 

London, vol. 64, 1908, pp. 127-148. 

2. -- The basis of pre-Cambrian correlation: Jour. Geology, vol. 17, 1909, pp. 105-123. 

3. Adams, F. D., Bell, Robert, Lane, A. C., Leith, C. K., Miller, W. G., and Van Rise, C. R., Report of 

the special committee on the Lake Superior region: Jour. Geology, vol. 13, 1905, pp. 89-104. 

4. Adams, G. I., Girty, G. H., and White, David, Stratigraphy and paleontology of the Upper Carboniferous 

rocks of the Kansas section: Bull. U.S. Geol. Survey No. 211, 1903, pp. 65-66; (a) p. 114. 

5. Adams, G. I., and others, Zinc and lead deposits of northern Arkansas, with a section on the determination 

and correlation of formations by E. 0. Ulrich: Prof. Paper U. S. Geol. Survey No. 24, 1904, pp. 24-28; 

(a) table opp. p. 90. • 

6. Adams, G. I., and Ulrich, E. 0., Fayetteville folio (No. 119), Geol. Atlas U. S., U. S. Geol. Survey, 1905. 

7. Aguilera, J. G., Sinopsis de geologia mexicana: Bol. Inst. geol. Mexico, Nos. 4, 5 and 6, 1897, p. 209. 

8. ~~- Guide des excursions du X" Congres geologique international, Mexico, 1906. 

9. ~~- Apen;:u sur la geologie du Mexique pour servir d'explication ala carte geologique de I' Amerique du Nord: 

Cong. geol. intern., Compt. rend. 10" sess., Mexico, 1906 (1907), p. 230; (a) pp. 231; (b) pp. 235-242; (c) pp. 

240-242; (J) p. 244; (e) pp. 244-245; (f) p. 245. 

10. -- Les gisements carboniferes de Coahuila (Mexico)· Cong. g6ol. intern., 10" sess., Guide des excursions, 

Mexico, No. 27, 1906 (1907); (a) p. 13 and table. 

11. Alden, W. C., Milwaukee special folio (.No. 140), Geol. Atlas U. S., U. S. Geol. Survey, 1906, p. 3. 

12. Ami, H. M., On the geology of Quebec and its environs: l:lull. Geol. Soc. America, vol. 2, 1tl9l, pp. 488-489; 

(a) p. 491. 

13. ~~-Notes on fossils from Quebec City: Ottawa Naturalist, vol. 8, 1894, pp. 82-90. 

14. -- Preliminary lists of organic remains occurring in formations comprised in southwest quarter map sheet 

of Eastern Townships of Province of Quebec: Ann. Eept. Geol. Survey Canada, new ser., vol. 7, 1896, Appendix p. 118 et seq.; (a) pp. 113-115 J, 123-133 J; (b) pp. 114-115 J; (c) pp. 123-133 J. 

15. ~~- On some Cambro-Silurian fossils from Lake Temiscaming, Lake Nipissing, and Mattawa outliers: Ann. 

Rept. Geol. Survey Canada, new ser., vol. 10, 1899, Appendix II, pp. 288-299 I; (a) p. 297 I. 

16. ~~- On the geology of the principal c1t1e" in eastern Canada: Proc. and Trans. Royal Soc. Canada, 2d ser., 

vol. 6, sec. 4, 1900, pp. 126-127 and table; (a) pp. 165-175; (b) table, p. 169. 

17. -- Synopsis of the geology of Canada: Proc. and Trans. Royal Soc. Canada, 2d ser., vol. 6, sec. 4, 1900, pp. 

202-204. 

18. ~~- Knoydart formation of Nova Scotia: Bull. Geol. Soc. America, vol. 12, 1901, pp. 301-312; (a) p. 302; 

(b) pp. 305-306; (c) pp. 306-307. 

19. --Lists of fossils from the several formations along the Ottawa River, pertaining to the report on the Grenville sheet: Rept. Geol. Survey Canada, new ser., vol. 12, 1902, pp. 139-143 J. 

20. -- Ordovician succession in eastern Ontario: Bull. Geol. Soc. America, vol. 13, 1903, pp .. 517-518; (a) 

p. 518. 

21. -- On the subdivisions of the Carboniferous system in eastern Canada: Proc. and Trans. Nova Scotian Inst. 

Sci., vol. 10, 1903, pp. 162-178. 

22. -- Meso-Carboniferous age of the Union and Riversdale formations, Nova Scotia: Bull. Geol. Soc, America, 

vol. 13, 1903, pp. 533-535; (a) pp. 533-534. 

840 
BIBLIOGRAPHY. 841 

23. Ami, H. M., Preliminary lists of fossil organic remains from the Potsdam, Beekmantown (Calciferous), Chazy, 

Black River, Trenton, Utica, and Pleistocene formations comprised within the Perth sheet in e::tstern Ontario: 

Ann. Rept. Geol. Survey Canada, new ser., vol. 14, 1905, Appendix pt. J; (a) pp. 80-89 J. 

24. --- Paleontology and chronological geology: Ann. Rept. Geol. Survey Canada, new ser., vol. 15, 1906, p. 319 

A; (a) pp. 319-323 A. 

25. --- Preliminary list of fossils collected by L. W. Bailey from various localities in New Brunswick in 1904; 

Ann. Rept. Geol. Survey Canada, new ser., vol. 16, 1906, Appendix pp. 289-290 A. 

26. --- Preliminary lists of organic remains from the Chazy, Black River, Trenton and Pleistocene formations 

comprised within the Pembroke sheet: Geol. Survey Canada, Appendix to Ells's report on Geology and 

natural resources of the northwest quarter-sheet, No. 122, 1907, pp. 47-71. 

27. Anderson, F. M., Cretaceous deposits of the Pacific coast: Proc. California Acad. Sci., 3d ser., Geology, vol. 2, 

1902, pp. 1-154. 

28. --- The physiographic features of the Klamath Mountains: Jour. Geology, vol. 10, 1902, pp. 152-153. 

29. Arnold, Ralph, Geological reconnaissance of the coast of the Olympic Peninsula, Washington: Bull. Geol. Soc. 

America, vol. 17, 1906, p. 459; (a) pp. 459-460; (b) pp. 460-461; (c) pp. 461-464. 

30. --- Geology and oil resources of the Summerland district, Cal.: Bull. U. S. Geol. Survey No. 321, 1907, p. 21. 

31. --- Environment of the Tertiary faunas of the Pacific coast of the United States: Jour. Geology, vol. 17, 1909, 

pp. 512-513. 

32. Arnold, Ralph, and Anderson, Robert, Preliminary report on the Santa Maria oil district, California: Bull. 

U. S. Geol. Survey No. 317, 1907, pp. 15-16. 

33. ---Geology and oil resources of the Santa Maria oil district, California: Bull. U. S. Geol. Survey No. 322, 

1907, pp. 27-30. 

34. ---Geology and oil resources of the Coalinga district, California: Bull. U. S. Geol. Survey No. 398, 1910, 

p. 48; (a) pp. 51-53; (b) pp. 51-61; (c) pp. 62-63; (d) pp. 75-77. 

35. Ashley, G. H., Geology of Arkansas: Proc. Am. Philos. Soc., vol. 36, 1897, p. 294. 

36. --- Coal deposits of Indiana: Twenty-third Ann. Rept. Indiana Dept. Geology and Nat. Res., 1899, pp. 85-91. 

37. --- Eastern Interior coal field: Twenty-second Ann. Rept. U. S. Geol. Survey, pt. 3, 1902, p. 273. 

38. --- The geology of the Lower Carboniferous area of southern Indiana: Twenty-seventh Ann. Rept. Indiana 

Dept. Geology and Nat. Res., 1903, pp. 71-89. 

39. --- Stratigraphy of southwestern Pennsylvania: Rept. Pennsylvania Top. and Geol. Survey Comm. 1906-

1908, 1908, pp. 130-132, 1.53-164; (a) pp. 152-154; (b) p. 161; (c) 165-186; (d) p. 186; (e) p. 190. 

40. --- Supplementary report (to report of 1898) on the coal deposits of Indiana: Thirty-third Ann. Rept. Indiana 

Dept. Geology and Nat. Res., 1909, pp. 13-150. 

41. Ashley, G. H., and Glenn, L. C., Geology and mineral resources of part of the Cumberland Gap coal field, Kentucky: Prof. Paper U.S. Geol. Survey No. 49, 190'6; (a) pp. 36, 49; (b) p. 209. 

42. Atwood, W. W., Mineral resources of southwestern Alaska: Bull. U. S. Geol. Survey No. 379, 1909, p. 113; (a) 

pp. 113-114; (b) p. 114; (c) p. 115. 

43. Bailey, L. W., Report on the geology of southwest Nova Scotia: Ann. Rept. Geol. Survey Canada, new ser., 

vol. 9, 1898, pp. 87-123 M; (a) p. 91 M. 

44. --- In Summary report by G. M. Dawson on work in New Brunswick: Ann. Rept. Geol. Survey Canada, 

new ser., vol. 13, 1903, pp. 146-147 A; (a) pp. 147-149 A. 

45. --- Carboniferous of New Brunswick: Ann. Rept. Geol. Survey Canada, new ser., vol. 13, 1903, Rept. M; 

(a) pp. 17-18, 37-38 M; (b) pp. 18-19 M; (c) p. 19M. 

46. --- Fossil occurrences and economic minerals in New Brunswick (in Summary report by Robert Bell): Ann. 

Rept. Geol. Survey Canada, new ser., vol. 16, 1904, pp. 280-281 A. 

47. Bailey, L. W., and Mcinness, Wm., Explorations in New Brunswick, Quebec, and Maine: Ann. Rept. Geol. 

Survey Canada, new ser., vol. 3, 1889, p. 12 M; (a) pp. 12-29 M; (b) pp. 29-31 M; (c) p. 35 ~1; (d) pp. 

40-46 M; (e) pp. 48, 51-52 M. 

48. --- Report on Province of Quebec and adjoining areas in New Brunswick and Maine: Ann. Rept. Geol. 

Survey Canada, new ser., vol. 5, 1893, pp. 7-8 M. 

49. Bailey, L. W., Matthew, P. F., and Ells, R. W., Geology of southern New Brunswick: Rept. Progress for 

1878-79, Geol. Survey Canada, 1880, pp. 14-15 D. 

50. Bain, H. F., The western interior coal field: Twenty-second Ann. Rept. U. S. Geol. Survey, pt. 3, 1902, p. 340; 

(a) pp. 340-343. 

51. ---Zinc and lead deposits of northwestern Illinois: Bull. B". S. Geol. Survey No. 246, 1905, pp. 18-22; (a) 

pp. 22-23. 

52. Bain, H. F., and Ulrich, E. 0., Copper deposits of Missouri: Bull. U. S. Geol. Survey No. 267, 1905, pp. 12-20; 

(a) pp. 20-36. 

53. Ball, M. W., The western part of the Little Snake River coal field, Wyoming: Bull. U. S. Geol. Survey No. 341, 

1909, pp. 244-246; (a) p. 246. 

54. Ball, S. H., A geological reconnaissance across southwestern ~evada and eastern California: Bull. U. S. Geol. 

Survey No. 308, 1907; (a) pp. 27, 31-34. 
842 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

55. Barlow, A. E., Report on Nipissing and Temiscaming map sheets: Ann. Rept. Geol. Survey Canada, new ser., 

vol. 10, 1899, pp. 118-123 I; (a) pp. 123-129 I. 

56. Barrell, Joseph, Origin and significance of the :\fauch Chunk shale: Bull. Geol. Soc. America, vol. 18, 1907, pp. 

449-476; (a) p. 451. 

57. Bascom, Florence, Piedmont district of Pennsylvania: Bull. Geol. Soc. America, vol. 16, 1905, pp. 289-328. 

58. Bascom, Florence, Darton, N. H., and others, Philadelphia folio (No. 162), Geol. Atlas U. S., U. S. Geol. 

Survey, 1909; (a) pp. 4-5; (b) p. 5; (c) p. 7. 

59.-- Trenton folio (No. 167), Geol. Atlas U.S., U.S. Geol. Survey, 1909. 

60. Bassler, R. S., Subdivisions of the Shenandoah limestone: Science, new ser., vol. 22, 1905, p. 756. 

61. Bastin, E. S., Rockland folio (No. 158), Geol. Atlas "G. S., U.S. Geol. Survey, 1908. 

62. Beede, J. W., Review of the Guadalupian fauna by G. H. Girty: Jour. Geology, vol. 17, 1909, pp. 672-679. 

63. ---The age of anthracolithic rocks: Jour. Geology, vol. 17, 1909, p. 710. 

64. Bell, J. M., Topography and geology of Great Bear Lake: Ann. Rept. Geol. Survey Canada, new ser., vol. 12, 

1902, pp. 24-25 C; (a) p. 25 C. 

65. Bell, Robert, Exploration between James Bay and Lakes Superior and Huron: Rept. Progress, Geol. Survey 

Canada, 1875-76, 1877, pp. 316-320, with lists of fossils by J. F. "\\niteaves. 

66. ---Report on Hudson Bay and some of the lakes and rivers lying to the west of it: Rept. Progress, Geol. Survey 

Canada, 1879-80, 1881, p. 30 C. 

67. ---Geology of the French River sheet: Ann. Rept. Geol. Survey Canada, new ser., vol. 9, 1898, p. 22 I; (a) 

p. 24 I. 

68. ---Exploration in Hudson Strait (in Summary report for year 1897 by G. M. Dawson): Ann. Rept. Geol. 

Survey Canada, new ser., vol. 10, 1899, p. 82 A; (a) pp. 82 A, 139 A. 

69. ---The northern side of Hudson Strait: Ann. Rept. Geol. Survey Canada, new ser., vol. 11, 1901, p. 16M. 

70. ---Summary report for 1903; Ann. Rept. Geol. Survey Canada, new ser., vol. 15, 1904, p. 153 A. 

71. Berkey, C. P., Paleogeography of St. Peter time: Bull. Geol. Soc. America, vol. 17, 1906, pp. 229-250. 

72. Berry, E. W., The flora of the Cliffwood clays: New Jersey Geol. Survey, Ann. Rept. State Geologist for 1905, 

1906, pp. 135-172. 

73. ---Contributions to the Mesozoic flora of the Atlantic Coastal Plain: Bull. Torrey Bot. Club, vol. 34, No. 4, 

1907, pp. 185-205. 

74. ---Some araucarian remains from the Atlantic Coastal Plain: Bull. Torrey Bot. Club, vol. 35, No. 5, 1908, 

pp. 249-260. 

75. ---A Miocene flora from the Virginia Coastal Plain: Jour. Geology, vol. 17, 1909, pp. 19-30. 

76. ---Contributions to the Mesozoic flora of the Atlantic Coastal Plain: Bull. Torrey Bot. Club, vol. 36, No. 5, 

1909, pp. 245-264. 

77. ---Geologic relations of the Cretaceous floras of Virginia and North Carolina: Abstract, Bull. Geol. Soc. 

America, vol. 20, 1910, pp. 655-659. 

78. ---Evidence of the flora regarding the age of the Raritan formation: Jour. Geology, vol. 18, 1910, pp. 252-258. 

79. ---Contributions to the Mesozoic flora of the Atlantic Coastal Plain-North Carolina: Bull. Torrey Bot. Club, 

vol. 37, 1910, pp. 181-200. 

80. ---Age of the type exposures of the Lafayette formation: Jour. Geology, vol. 19, 1911, pp. 249-256. 

81. Billings, Elkanah, Paleozoic fossils: Rept. Geol. Survey Canada, vol. 1, 1865, pp. 371-372; (a) pp. 372-373; 

(b) pp. 373-377. 

82. ---Catalogues of the Silurian fossils of the Island of Anticosti: Rept. Geol. Survey Canada, 1866, p. 75; (a) 

pp. 76-78. 

83. --- On some fossils of the Gaspe series of rocks: Paleozoic fossils, Geol. Survey Canada, vol. 2, pt. 1, 1874, 

pp. 1-64. 

84. Blackwelder, Eliot, New light on the geology of the ·wasatch Mountains, Utah: Bull. Geol. Soc. America, vol. 

21, 1910, pp. 517-542; (a) pp. 519, 529-530; (b) p. 523; (c) p. 526; (d) p. 527; (e) pp. 527-528. 

85. Blake, W. P., Report on the geology of the route, explorations, and surveys for a railroad route from the Mississippi River to the Pacific Ocean: \Yar Dept., Route near the 35th parallel, Lieut. A. W. \'nipple, vol. 3, 1856, 

pp. 25-26. 

86. Blatchley, W. S., and Ashley, G. H., Geological scale of Indiana: Twenty-second Ann. Rept. Indiana Dept. 

Geology and Nat. Res., 1898, pl. 2, pp. 20-21. 

87. Bose, Emil, Geologia de los alrededores de Orizaba: Bol. lust. geol. Mexico No. 13, 1899, pp. 5-10. 

88. --- Reseiia acerca de la geologia de Chiapas y Tabasco: Bol. Inst. geol. Mexico, No. 20, 1905, pp. 25-26. 

89. ---La fauna de moluscos del Senoniano de Cardenas, San Luis Potosi: Bol. Inst. geol. Mexico, No. 24, 1906, 

p. 15. 

90. ---Excursion a l'Isthme de Tehuantepec: Cong. geol. intern., 10• sess., Guide des excursions, Mexico, No. 31, 

1906; (a) p. 6. 

91. ---Excursion au Cerro de Muleros: Cong. geol. intern., 10• sess., Guide des excursions, Mexico, No. 20, 

1906, pp. 3 et seq. 

92. --- Monografia geologica y paleontol6gica del Cerro de Muleros: Bol. lust. geol. Mexico, No. 25, 1910, p. 18. 

93. Boutwell, J. M., Stratigraphy and structure of the Park City mining district, Utah: Jour. Geology, vol. 15, 

1907, p. 439; (a) pp. 446-454; (b) p. 454. 
BIBLIOGRAPHY. 843 

94. Brainard, Ezra, The Chazy formation in the Champlain Yalley: Bull. Geol. Soc. America, vol. 2, 1891, pp. 

295-29(L 

95. Brainard, Ezra, and Seely, H. M., The Calciferous formation in the Champlain Valley: Bull. Am. Mus. Nat. 

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96. Branner, J. C., Paleozoic sediments in Arkansas: Am. Jour. Sci., 4th ser., vol. 2, 1896, p. 235. 

97. Branner, J. C., and others, Santa Cruz folio (~o. 16:i), Geol. Atlas U. S., U. S. Geol. Survey, 1909; (a) p. 3. 

98. Broadhead, G. C., The Ozark uplift and growth of the Missouri Paleozoic: Missouri Geol. Survey, vol. 12, 

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99. Brock, R. W., The Kootenay district, British Columbia (in Summary report for 1900, by G. M. Dawson): Ann. 

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100. ---The Boundary Creek district, British Columbia (in Summary report for 1901): Ann. Rept. Geol. Survey 

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101. Brooks, A. H., Geography and geology of Alaska: Prof. Paper U. S. Geol. Survey No. 45, 1906, table opp. p. 

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102. Brooks, A. H., and Kindle, E. M., Paleozoic section of the upper Yukon: Abstract, Science, new ser., vol. 25, 

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103. ---Paleozoic and associated rocks of the upper Yukon, Alaska: Bull. Geol. Soc. America, vol. 19, 1908, 

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104. Brooks, A. H., and Prindle, L. M., The Mount McKinley region, Alaska: Prof. Paper l:". S. Geol. Survey 

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105. Brummel, H. P. H., Natural gas and petroleum in Ontario prior to 1891: Ann. Itept. Geol. Survey Canada, 

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106. Buckley, E. R., Geology of the di-sseminated lead deposits of St. Francois and \Yashington counties, Mo.: Rept. 

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107. Burchard, E. F., Butts, Charles, and Eckel, E. C., Iron ores, fuels, and fluxes of the Birmingham district, 

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108. Burckhardt, Carlos, La faune marine du Trias superieur de Zacatecas: Bol. Inst. geol. :Mexico, No. 21, 1905. 

109. ---Geologie de la Sierra de Mazapil et Santa Rosa: Cong. geol. intern., 10• sess., Guide des excursions, 

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110. ---La faune jurassique de Mazapil, avec un appendice sur les fossiles du cretacique inferieur: Bol. Inst. 

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111. Burckhardt, Carlos, and Scalia, S., Geologie des environs de Zacatecas: Cong. geol. intern., 10• sess., Guide 

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112. Butts, Charles, The Devonian section near Altoona: Jour. Geology, vol. 14, 1906, pp. 618-630. 

113. ---Northern part of the Cahaba coal field, Alabama: Bull. U.S. Geol. Survey No. 316, 1907, p. 76. 

114. Cairnes, D. D., Report on a portion of Conrad and Whitehorse districts, Yukon: Canada Dept. Mines, Geol. 

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115. Calvert, W. R., The Lewistown coal field, Montana: Bull. U.S. Geol. Survey No. 341, 1909, pp. 109-111. 

116. Calvin, Samuel, The LeClaire limestone: Proc. Iowa Acad. Sci. for 1895, vol. 3, 1896, pp. 52-54. 

117. ---Geology of lloward County: Ann. Rept. Iowa Geol. Survey, vol. 13, 1903, p. 49. 

118. ---Geology of \Vinneshiek County: Ann. Rept. Iowa Geol. Survey, vol. 16, 1906, p. 60. 

119. Campbell, H. D., Cambro-Ordovician limestones of the middle portion of the Valley of Virginia: Am. Jour. 

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120. Campbell, J. L., Silurian formation in central Virginia: Am. Jour. Sci., 3d ser., voL 18, 1879, pp. 20-27. 

121. Campbell, M. R., Estillville folio (No. 12), Geol. Atlas U.S., U.S. Geol. Survey, 1894; (a) columnar section3. 

122. --- Paleozoic overlaps in Montgomery and Pulaski counties, Va.: Bull. Geol. Soc. America, vol. 5, 1894, pp. 

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123. ---Pocahontas folio (No. 26), Geol. Atlas U. S., U. S. Geol. Survey, 1896. 

124. ---Tazewell folio (No. 44), Geol. Atlas U.S., U.S. Geol. Survey, 1897. 

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127. Campbell, M. R., and Mendenhall, W. C., Geologic section along the New and Kanawha rivers in West Virginia: Seventeenth Ann. Rept. U. S. Geol. Survey, pt. 2, 1896, p. 473. 

128. Camsell, Charles, Peel River and tributaries, Yukon and Mackenzie: Ann. Rept. Geol. Survey Canada, new 

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129. ---Preliminary report on a part of the Similkameen district, British Columbia: Rept. Geol. Survey Canada, 

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130. Case, E. C., Vertebrate fossils from the vicinity of Pittsburg: Annals Carnegie Mus., vol. 4, 1906_:1908, pp. 

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131. ---On the value of the evidence of vertebrate fossils of age of certain so-called Permian beds in America: 

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132. Castillo, A. del, and Aguilera, J. G., Fauna fosil de la Sierra de Catorce: Bol. Com. geol. Mexico, No.1, 1895. 
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133. Chamberlin, T. C., Geology of Wisconsin: Yo!. l, 1883, pp. 119, 121-122; (a) p. 138; (b) map opp. p. 151; (c) 

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134. Chamberlin, T. C., and Salisbury, R. D., Geology, vol. 2, 1906, p. 500; (a) vol. 3, p. 554; (b) p. 556; (c) p. 558. 

135. Chance, H. M., The Conglomerate series or Beayer River series; The Berea grit: Rept. Progress V, Second 

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136. Chapman, E. J., Exposition of the minerals and geology of Canada, Toronto, 1864, p. 190. 

137. Clapp, C. H., Southeastern portion of Vancouver Island: Summary Rept. Geol. Survey Canada for 1908, 1909, 

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138. ---Southern Vancouver Island: Summary Rept. Goo!. Survey Canada for 1909, 1910, p. 87. 

139. Clapp, F. G., Clay of probable Cretaceous age at Boston, Mass.: Am. Jour. Sci., 4thser., vol. 23,1907, pp.183-185. 

140. Clark, W. B., On the Tertiary deposits of the Cape .Fear River region: Bull. Geol. Soc. America, vol. 1, 1890, 

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141. ---Correlation papers, Eocene: Bull. U.S. Geol. Survey No. 83, 1891, pp. 111-143. 

142. ---Preliminary report on the Cretaceous and Tertiary formations of New Jersey: Ann. Rept. New Jersey 

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143. ---Physical features of Maryland: Maryland Geol. Survey, vol. 1, 1897, p. 171. 

144. ---Results of a recent investigation of the Coastal Plain formations in the area between Massachusetts and 

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145. ---(with collaboration of R. l\f. Bagg and G. B. Shattuck), Upper Cretaceous formations of New Jersey: 

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146. ---(with collaboration of R. .M:. Bagg and G. B. Shattuck), Upper Cretaceous formations of New Jersey, 

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147. Clark, W. B., and Bibbins, Arthur, The stratigraphy of the Potomac group in Maryland: Jour. Geology, vol. 

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148. --Geology of the Potomac grouP. in the middle Atlantic slope: BulL Geol. Soc. America, vol. 13, 1902, 

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149. Clark, W. B., and Martin, G. C., The Eocene deposits of Maryland: Eocene, Maryland Geol. Survey, 1901, 

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150. Clark, W. B., and Mathews, E. B., The physical features of Maryland: Maryland Geol. Survey, wl. 6, 1906, 

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151. Clark, W. B., and Miller, B. L., A brief summary of the geology of tho Virginia Coastal Plain: Virginia Geol. 

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152. Clark, W. B., and others, Philadelphia folio (No. 162), Geol. Atlas U.S., U. S. Geol. Survey, 1909. 

153. Clarke, J. M., The Naples fauna in western New York, Part I: Sixteenth Ann. Rept. New York Geol. Survey, 

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154. ---The Naples fauna in western New York, Part II: Mem. New York State Mus. No.6, 1903. 

155. ---Classification of the New York series of geologic formations: Handbook New York State Mus., No. 19, 

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156. --- Eurypterus shales of the Shawangunk Mountains in eastern l>.,.ew York: Bull. New York State Mus. No. 

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157. ---Early Devonic history of New York and eastern North America: Mem. New York State l\Ius., No. 9, 

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158. Clarke, J. M., and Ruedemann, R., Guelph fauna in the State of New York: Mem. New York State Mus., 

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1,59. Clarke, J. M., and Schuchert, Charles, Nomenclature of theN ew York series of geological formations: Science, 

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160. Cleland, H. F., Fauna of tho Hamilton formation of the Cayuga J,ake section in central Now York: Bull. U. S. 

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161. Cockerell, T. D. A., Fossil insects from Florissant, Colo., Bull. Am. Mus. Nat. Hist., vol. 24, 1908, pp. 59-69. 

162. ---Fossil flora of Florissant, Colo.: Bull. Am. Mus. Nat. Hist., vol. 24, 1908, pp. 71-110. 

163. Collier, A. J., Coal resources of the Yukon, Alaska: Bull. U. S. Geol. Survey No. 218, 1903, pp. 15-17. 

164. --Coal fields of the Cape Lisburne region: Bull. U. S. Geol. Survey No. 259, 1905, pp. 172-185; (a) pp. 

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165. ---Geology and coal resources of the Cape Lisburne region, Alaska: Bull. U.S. Geol. Survey No. 278, 1906, 

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166. Collier, A. J., and others, The gold placers of parts of Seward Peninsula, Alaska: Bull. U. S. Geol. Survey 

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167. Collier, A. J., and Smith, C. D., The J\filfs City coal field, Montana: Bull. U. S. Geol. Survey No. 341, 1909, 

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168. Conrad, T. A., Fossil shells of the Tertiary formation of North America, vol. 1, 1832-1835, republication by 

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169. Cook, G. H., Geology of New Jersey, 1868, pp. 239-289, and articles in other annual reports of New Jersey 

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172. Cragin, F. W., Description of the invertebrate fossils from the Comanche series in Texas, Kansas, and Indian 

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175. --The Permian system in Kansas: Colorado Coli. Studies, vol. 6, 1896; (a) p. 18. 

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177. --- Paleontology of the Malone Jurassic formation of Texas: Bull. U. S. Geol. Survey No. 266, 1905, pp. 

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178. Crider, A. F., Geology and mineral resources of Mississippi: Bull. U. S. Geol. Survey No. 283, 1906; (a) 

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179. Crider, A. F., and Johnson, L. C., Underground-water resources of Mississippi: Water-Supply Paper U. S. 

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187. --La Plata folio (No. 60), Geol. Atlas U. S., U. S. Geol. Survey, 1899. 

188. ---Silverton folio (No. 120), Geol. Atlas U. S., U.S. Geol. Survey, 1905, p. 3. 

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203. ---Geology of the northern Adirondack region: Bull. New York State Mus. No. 95, 1905, pp. 282-285; (a) 

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204. --Lower portion of the Paleozoic section in northwestern New York: Bull. Geol. Soc. America, vol. 19, 

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205. Dale, T. N., On the structure and age of the Stockbridge limestone in the Vermont valley: Abstract, Bull. 

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206. ---Mount Greylock, its areal and structural geology: Mon. U.S. Geol. Survey, vol. 23, pt. 3, 1894, p. 190. 

207. ---Slate belt of eastern New York and western Vermont: Nineteenth Ann. Rept. U.S. Geol. Survey, pt. 3, 

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208. ---Geology of the Hudson Valley between the Hoosac and the Kinderhook: Bull. U. S. Geol. Survey No. 

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209. Dall, W. H., Notes on the Miocene and Pliocene of Gay Head, Marthas Vineyard, Massachusetts: Am. Jour. 

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210. ---Coal and lignite of Alaska: Seventeeth Ann. Rcpt. U. S. Geol. Survey, 1896, pp. 799-800; (a) p. 814. 

211. ---Table of North American Tertiary horizon~: Eighteenth Ann. Hept. U. S. Geol. Survey, pt. 2, 1898, 

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212. ---Contributions to the Tertiary fauna of Florida: Trans. Wagner F1ee Inst. Sci. Philadelphia, vol. 3, pts. 

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213. ---Contributions to the Tartiary paleontology of the Pacific coast; I, The ::\fiocene of Astoria and Coos Bay, 

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214. Dall, W. H., and Harris, G. D., Correlation papers-Neocene: Bull. U.S. Geol. Survey No. 84, 1892. 

215. Dana, J. D., Manual of geology, revised ed., 1864, p. 246. 

216. ---Discoveries in Vermont geology by Rev. Augustus \Ying: Am. Jour. Sci., 3d ser., vol. 13, 1877, p. 332. 

217. ---Geological age of the Taconic system: Quart. Jour. Geol. Soc. London, vol. 38, 1882, pp. 397-408. 

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219. ---Taconic rocks and stratigraphy: Am. Jour. Sci., 3d ser., vol. 33, 1887, pp. 27(}-276, 393-419. 

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221. Darton, N. H., Notes on stratigraphy of a portion of central Appalachian Virginia: Am. Geologist, vol. 10, 

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224. ---Report on the relations of the Helderberg limestones, etc., in eastern New York: Forty-seventh Ann. 

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225. ---Reports on Albany and Ulster courrties, N.Y.: Forty-seventh Ann. Rept. New York State J\fus., 189·!, 

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226. ---Staunton folio (No. 14), Geol. Atlas U. S., U. S. Geol. Survey, 1894; (a) columnar section. 

227. ---Preliminary reports on Albany and on Ulster counties, N.Y., and also on the relations of the Helderberg limestones and associated formations of eastern New York: Thirteenth Ann. Rept. State Geologist, for 

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228. --Piedmont folio (No. 28), Geol. Atlas U.S., U.S. Geol. Survey, 1896. 

229. --Franklin folio (No. 32), Geol. Atlas U.S., U.S. Geol. Survey, 1896. 

230. ---Catalogue and index of contributions to North American geology, 1732 to 1891: Bull. U. S. Geol. Survey 

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231. --Monterey iolio (No. 61), Geol. Atlas U. S., U. S. Geol. Survey, 1899. 

232. --- Geology and water resources of the southern half of the Black Hills and adjoining regions in South Dakota 

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233. --- Preliminary report on geology and water resources of Nebraska west of the one hundred a11d third me rid 

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234. --Camp Clarke folio (No. 87), Geol. Atlas U.S., U.S. Geol. Survey, 1903. 

235. --Scotts Bluff folio (No. 88), Geol. Atlas U. S., U. S. Geol. Survey, 1903. 

236. ---Newcastle folio (No. 107), Geol. Atlas U.S., U.S. Geol. Survey, 1904, columnar sections. 

237. ---Comparison of the stratigraphy of the Black Hills, Bighorn Mountains, and Rocky Mountain Front Range; 

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238. ---Geology and underground water resources of the central Great Plains: Prof. Paper U. S. Geol. Survey 

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239. --Geology of the Bighorn Mountains: Prof. Paper U.S. Geol. Survey No. 51, 1906; (a) p. 25; (b) pp. 34-42; 

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240. ---Geology and underground waters of the Arkansas Valley in eastern Colorado: Prof. Paper U. S. Geol. 

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241. ---Fish remains in Ordovician rocks in Bighorn Mountains, Wyoming, with a resume of Ordovician geology 

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242. ---Red Beds in the Laramie mountain region: Abstract, Bull. Geol. Soc. America, vol. 17, 1907, pp. 724-725. 

243. --- Discovery of Cambrian rocks in southeastern California: Jour. Geology, vol. 15, 1907, pp. 470-473. 

244. ---Paleozoic and Mesozoic of central Wyoming: Bull. Geol. Soc. America, vol. 19, 1908, pp. 403-470; (a) 

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245. ---Belle Fourche folio (No. 164), Geol. Atlas U. S., U.S. Geol. Survey, 1909, columnar section. 

246. ---Reconnaissance of parts of northwestern New Mexico and northern Arizona: Bull. U. S. Geol. Survey 

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247. Darton, N.H., and Siebenthal, C. E., Geology and mineral resources of the Laramie Basin: Bull. U.S. 

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248. Davis, W. M., The Triassic formation of Connecticut: Eighteenth Ann. Rept. U. S. Geol. Survey, pt. 2, 1898; 

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Geol. Survey Canada, new ser., vol. 2, 1886 (1887), pp. 9, 51-52 R; (a) p. 10 R; (b) p. 12 R; (c) p. 15 R; (d) 

pp. 21, 29 R; (e) pp. 30-46 R; (f) 45 R; (g) 52 R. 

---Exploration in the Yukon district: Ann. Rept. Geol. Survey Canada, new ser., vol. 3, 1889, pp. 36-37 B; 

(a) p. 94 B; (b) pp. 95-102 B. 

---Mineral wealth of British Columbia: Ann. Rept. Geol. Survey Canada, new ser., vol. 3, 1889, pp. 8il89 R. 

260. ---Coasts of Bering Sea and vicinity: Bull. Geol. Soc. America, vol. 5, 1894, pp. 134-135. 

261. --- Report on area of the Kamloops sheet, British Columbia: Ann. Rept. Geol. Survey Canada, new ser., 

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262. ---Duplication of geologic formation names: Science, new ser., vol. 9, 1899, pp. 592-593. 

263. Dawson, J. W., Acadian geology, 3d ed., London, 1878, p. 87; (a) p. 93; (b) p. 111; (c) p. 125; (d) pp. 

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264. ---Quebec group in geology: Appendix A to Life of Sir \Y. E. Logan by B. J. Harrington, published at 

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265. ---On fossil plants collected by R. A. McConnell on Mackenzie River: Trans. Royal Soc. Canada, vol. 7, 

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266. ---The geology of Nova Scotia, New Brunswick, and Prince Edward Island, or Acadian geology, 4th ed., 

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267. ---Additional notes on fossil sponges and other organic remains from the Quebec group of Little Metis, on 

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268. De Wolf, F. W., Coal investigations in Saline and Williamson counties: Bull. Illinois Geol. Survey No.8, 1908, 

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269. Diller, J. S., Geology of the Lassen Peak district: Eighth Ann. Rept. U. S. Geol. Survey, pt. l, 1889, p. 407. 

270. ---Cretaceous rocks of northern California: Am. Jour. Sci., 3d ser., vol. 40, 1890, pp. 476-478. 

271. ---Geology of the Taylorsville region, California: Bull. Geol. Soc. America, vol. 3, 1892, pp. 369-394; (a) 

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272. ---Lassen Peak folio (No. 15), Geol. Atlas U. S., U. S. Geol. Survey, 1895. 

273. --- Gedogical reconnaissance in northwestern Oregon: Seventeenth Ann. Rept. U. S. Geol. Survey, pt. 1, 

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274. ---Roseburg folio (No. 49), Geol. Atlas U. S., U. S. Geol. Survey, 1898. 

275. --Coos Bay folio (No. 73), Geol. Atlas U. S., U. S. Geol. Survey, 1901. 

276. --- Klamath Mountains section, California: Am. Jour. Sci., 4th ser., vol. 15, 1903, pp. 356-358; (a) pp. 

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277. ---Port Orford folio (No. 89), Geol. At1as U. S., U. S. Geol. Survey, 1903. 

278. ---The Bragdon formation: Am. Jour. t-lci., 4th ser., vol. 19, 1905, pp. 379-387. 

279. --Redding folio (No. 138), Geol. Atlas U.S., U.S. Geol. Survey, 1906; (a) p. 6. 

280. ---Geology of the Taylorsville region, California: Bull. U. S. Geol. Survey No. 353, 1908, pp. 13 et seq.; 

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281. ---The Rogue River valley coal field, Oregon: Bull. U. S. Geol. Survey No. 341, 1909, pp. 401-402. 

282. Diller, J. S., and Kay, G. F., Mineral resources of the Grants Pass quadrangle, Oregon: Bull. U. S. Geol. 

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283. Diller, J. S., and Schuchert, Charles, Devonian rocks in California: Am. Jour. Sci., 3d ser., vol. 47, 1894, 

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284. Diller, J. S., and Stanton. T. W., Shasta-Chico series: Bull. Geol. Soc. America, vol. 5, 1894; (a) pp. 435-

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848 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

285. D'Invilliers, E. V., Summary description of geology of Pennsylvania, Carboniferous: Summary Final Rept. 

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286. Dollfuss, Auguste, and Mont-Serrat, E. de, Yoyage geologique dans les republiques de Guatemala et de 

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287. Douglass, Earl, Neocene Lake beds of western Montana (thesis), Univ. Montana, 1899. 

288. ~~-New vertebrates from the Montana Tertiary: Annals Carnegie Mus., vol. 2, 1903, pp. 145-200. 

289. Dowling, D. B., General index to the Reports of progress, 1863-1884, Geol. Survey Canada, 1900. 

290. ~~-Geology of the west shore and islands of Lake Winnipeg: Ann. Rept. Geol. Survey Canada, new ser., 

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291. ~~-Exploration of Ekwan River, Sutton Mill Lakes, etc.: Ann. Rept. Geol. Survey Canada, new ser., vol. 

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292. ~~-Report on the Cascade coal basin, Alberta: Geol. Survey Canada, No. 949, 1907, p. 8. 

293. Drake, N. F., Stratigraphy of the Triassic formation of northwest Texas: Third Ann. Rept. Texas Geol. Survey, 

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294. Dumble, E. T., Notes on the geology of the valley of the middle Rio Grande: Bull. Geol. Soc. America, vol. 3, 

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295. ~~-Notes on geology of Sonora, Mexico: Trans. Am. Inst. Min. Eng., vol. 29, 1900, pp. 122-152. 

296. ~~-Notes on the geology of southeastern Arizona: Trans. Am. Inst. Min. Eng., vol. 31, 1902, pp. 710-713. 

297. ~~-Geology of southwestern Texas: Trans. Am. Inst. Min. Eng., vol. 33, 1903, pp. 913-987; (a) pp. 936-938, 

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298. ~~-Tertiary deposits of northeastern Mexico: Science, new ser., vol. 33, 1911, pp. 232-234. 

299. Dumble, E. T., Kennedy, William, Herndon, J. H., and Walker, J. B., Reports on the iron district of 

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300. Dutton, C. E., Geology of the high plateaus of Utah: U.S. Geog. and Geol. Survey Rocky Mtn. Region, 1880, 

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301. ~~-Mount Taylor and the Zuni Plateau: Sixth Ann. Rept. U. S. Geol. Survey, 1885; (a) pp. 106-198; (b) 

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302. Eastman, C. R., Devonic fishes of the New York formations: Mem. New York State Mus. No. 10, 1907, p. 10. 

303. Eldridge, G. H., Method ofgrouping the formations of the Middle Cretaceous: Am. Jour. Sci., 3d ser., vol. 38, 

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304. --Anthracite-Crested Butte folio (No.9), Geol. Atlas U. S., U. S. Geol. Survey, 1894. 

305. Ells, R. W., Geology of northern New Brunswick: Rept. Progress for 1879-80, Geol. Survey Canada, 1881, pp. 

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306. ~--Report on the Gaspe Peninsula: Rept. Progress for 1880-1882, Geol. Survey Canada, 1883, pp. 15-16 DD. 

307. -~-Northern and eastern New Brunswick and north side of the Bay of Chaleurs: Rept. Progress for 1880-

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308. ---Explorations and surveys in interior of Gaspe Peninsula: Rept. Progress for 1882-1884, Geol. Survey 

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309. -~-Geological formations of eastern Albert and Westmorland counties, New Brunswick, and portions of 

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310. -~-Report on a portion of the Eastern Townships: Ann. Rept. Geol. Survey Canada, new ser., vol. 2, 1887, 

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311. ---Geology of a portion of the province of Quebec: Ann. Rept. Geol. Survey Canada, new ser., vol. 3, 1889; 

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312. ---Stratigraphy of the Quebec group: Bull. Geol. Soc. America, vol. 1, 1890, pp. 453-468. 

313. ---Portion of the Province of Quebec, southwest sheet of "Eastern Townships": Ann. Rept. Geol. Survey 

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314. -~-Geology of the Three Rivers map sheet: Ann. Rept. Geol. Survey Canada, new ser., vol. 11, 1901, p. 13 J. 

315. ---Charlotte County, New Brunswick: Ann. Rept. Geol. Survey Canada, new ser., vol. 15, 1903, pp. 151-

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316. ~~-Graham Island, British Columbia: Ann. Rept. Geol. Survey Canada, new ser., vol. 16, 1906; (a) pp. 

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317. Ells, R. W., and Bailey, L. W., Lower Carbonijerous belt of Albert and Westmorland counties, New Brunswick: Rept. Progress for 1876-77, Geol. Survey Canada, 1878, PI?· 353-355. 

318. Emerson, B. K., On the geology of Frobisher Bay: Appendix to Narrative of the second Arctic expedition 

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319. ---Geology of old Hampshire County, Massachusetts: Mon. U. S. Geol. Survey, vol. 29, 1898; (a) p. 354. 

320. Emmons, S. F., Tertiaries of the Uinta Valley: U.S. Geol. Expl. 40th Par., vol. 2, 1877, pp. 307-310. 

321. ---Geology and mining industry of Leadville, Colorado: Mon. U. S. Geol. Survey, vol. 12, 1886, p. 57; (a) 

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322. Emmons, S. F., Cross, Whitman, and Eldridge, G. H., Geology of the Denver Basin in Colorado: Mon. 

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323. Emmons, S. F., and Merrill, G. P., Geological sketch of Lower California: Bull. Geol. Soc. America, vol. 5, 

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324. Emmons, W. H., Reconnaissance of some mining camps in Elko, Lander, and Eureka counties, Nev.; Bull. 

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325. Fairbanks, H. W., San Luis Potosi folio (No. 101), Geol. Atlas U. S., U. S. Gcol. Survey, 1904; (a) p. 3. 

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328. Fenneman, N. M., Geology of the Boulder district, Colorado: Bull. U. S. Geol. Survey No. 265, 1905, p. 22; 

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329. Fenneman, N. M., and Gale, H. S., The Yampa coal field, Routt County, Colo.: Bull. U. S. Geol. Survey 

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330. Fischer, Paul, On some fossils from Alaska: Compt. Rend. Acad. Sci. Paris, vol. 75, 1872, p. 1784. 

331. Fisher, C. A., Geology and water resources of the Bighorn Basin, Wyoming: Prof. Paper U. S. Geol. Survey 

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332. --Geology of the Great Falls coal field, Montana: Bull. U. S. Geol. Survey No. 356, 1909, pp. 27-28; (a) 

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333. Fletcher, Hugh, Report on parts of the counties of Richmond, Inverness, Guysborough, and Antigonish, 

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334. ---Geological surveys and explorations in the counties of Guysborough, Antigonish, Pictou, and Colchester, 

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335. ---Geological surveys and explorations in the counties of Pictou and Colchester, Nova Scotia: Ann. Rept. 

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337. ---The Cincinnati anticline in southern Kentucky: Am. Geologist, 1902, pp. 359-369. 

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343. Fontaine, W. M., The•Potomac formation in Virginia: Bull. U. S. Geol. Survey No. 145, 1896. 

344. Fontaine, W. M., and White, I. C., Permian or upper Carboniferous flora of West Virginia and southwestern 

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345. Ford, S. W., Note on certain fossils discovered within the city limits of Quebec: Trans. New York Acad. Sci., 

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346. Freeman, H. C., Lasalle County, Geol. Survey Illinois, vol. 3, 1868, p. 261. 

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348. Fuller, M. L., and Clapp, F. G., Patoka folio (No. 105), Geol. Atlas U. S., U. S. Geol. Survey, 1904. 

349. Gabb, W. M., Paleontology of California: Geol. Survey California, vol. 1, 1864. 

350. --Lower California: Report of J. Ross Browne on the mineral resources of the States and Territories west 

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351. --Paleontology of California: Geol. Survey California, vol. 2, 1869. 

352. ---On the topography and geology of Santo Domingo: Trans. Am. Philos. Soc., new ser., vol. 15, 1872 (1881), 

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354. --Coal fields of northwestern Colorado and northeastern Utah: Bull. U. S. Geol. Survey No. 341, 1909, 

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355. --Coal fields of northwestern Colorado and northeastern litah: Bull. U. S. Geol. Survey No. 415, 1910. 

356. Gale, H. S., and Richards, R. W., Phosphate deposits in southeastern Idaho and adjacent parts of Wyoming 

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48011°--12----54 
850 INDEX '1'0 THE STRATIGRAPHY OF NORTH AMERICA. 

357. Gale, H. S., and Wegemann, C. H., The Buffalo C'oal field, Wyoming: Bull. U.S. Geol. Survey J'\o. :381, 1910, 

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358. Gardner, J. H., The coal field between Gallina and Haton Spring, New Mexico: Bull. U. S. Geol. Survey 

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359. Gibson, A. M., Report on the Coosa coal field: Alabama Geol. Survey, 1895. 

360. Gilbert, G. K., Geology of portions of Nevada, Utah, California, and Arizona: U. S. Geog. Surveys W. lOOth 

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361. Girty, G. H., Waverly group in northeastern Ohio: Abstract, Science, new ser., vol. 13, 1901, p. 664. 

362. ---The Carboniferous formations and faunas of Colorado: Prof. Paper U. S. Geol. Survey No. 16, 1903, pp. 

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363. ---Relations of some Carboniferous faunas: Proc. Washington Acad. Sci., vol. 7, 1905; (a) pp. 3--4; (b) pp. 

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364. ---The Guadalupian fauna: Prof. Paper U. S. Geol. Survey No. 58, 1908. 

365. --Some new and old species of Carboniferous fossils: Proc. U. S. Nat. Mus., vol. 34, 1908, pp. 281-303. 

366. ---Fauna of the Caney shale of Oklahoma: Bull. U. S. Geol. Survey No. 377, 1909, pp. 8-10. 

367. ---The Guadalupian fauna and new stratigraphic evidence: Annals New York Acad. Sci., vol. 19, 1909, 

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368. Glenn, L. C., Underground waters of Tennessee: \Vater-Supply Paper U. S. Geol. Survey No. 114, 1905, pp. 

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369. ---Underground waters of Tennessee and Kentucky: Water-Supply Paper U. S. Geol. Survey No. 164, 

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370. Gordon, C. H., Geology and underground waters of northeast Texas: \Vater-Supply Paper U. S. Geol. Survey 

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371. Gordon, C. H., Girty, G. H., and White, David, The Wichita formation of northern Texas: Jour. Geology, 

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372. Gordon, C. H., and Graton, L. C., Lower Paleozoic formations in New Mexico: Am. Jour. Sci., 4th ser., voL 

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373. Gould, C. N., Geology and water resources of Oklahoma: Water-Supply Paper U. S. Geol. Survey No. 148, 

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374. ---Geology and water resources of the western Panhandle of Texas: Water-Supply Paper U.S. Geol. Survey 

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375. Gould, C. N., Ohern, D. W., and Hutchinson, L. L., Proposed groups of Pennsylvanian rocks of eastern 

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376. Grabau, A. W., The faunas of the Hamilton group (in Stratig~aphy of Eighteen-mile Creek and adjacent territory): Sixteenth Ann. Rept. New York State Survey, 1899, pp. 233-240. 

377. --- Siluro-Devonic contact in Erie County, N.Y.: Bull. Geol. Soc. America, vol. 11, 1900, pp. 347-376. 

378. ---Geology and paleontology of Niagara Falls and vicinity: Bull. New York State Mus. No. 45, 1901. 

379. --Stratigraphy of the Traverse group: Ann. Rept. Michigan Geol. Survey for 1901, 1902. 

380. ---Stratigraphy of Becraft Mountain, Columbia County, N.Y.: Bull. New York State Mus. No. 69, 1903. 

381. ---Guide to geology and paleontology of the Schoharie Valley in eastern New York: Bull. New York State 

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382. ---Discovery of the Schoharie fauna in Michigan: Bull. Geol. Soc. America, vol. 17, 1907, pp. 718-719. 

383. ---Revised classification of the North American Lower Paleozoic: Science, new ser., vol. 29, 1909, pp. 

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384. ---Physical and faunal evolution of North America during OrdoviciC', Siluric, and early :Qevonic time (in 

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385. Grabau, A. W., and Sherzer, W. H., The Monroe formation of southern Michigan and adjoining regions: Michigan Geol. Survey, Geol. ser. 1, Pub. 2, 1910. 

386. Grant, U. S., and others, Lancaster-Mineral Point folio (No. 145), Geol. Atlas U. S., l'. S. Geol. Survey, 1907. 

387. Gregory, H. E., The crystalline rocks (in Manual of the geology of Connecticut, by W. N. Rice and H. E. Gregory, Hartford Press, 1906, pp. 86-93). 

388. Gurley, R. R., North American graptolites: Jour. Geology, vol. 4, 1896, pp. 63-102, 291-311. 

389. Gwillim, J. C., Report on the Atlin mining district, British Columbia: Ann. Rept. Geol. Survey Canada, new 

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390. Hague, Arnold, West Humboldt region: U.S. Geol. Expl. 40th Par., vol. 2, 1877, pp. 727, 732. 

391. ---Geology of the Eureka district, Nevada: Mon. U.S. Geol. Survey, vol. 20, 1892, pp. 57-59; (a) pp. 58-60; 

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392. Hague, Arnold, and others, Yellowstone National Park folio (No. 30), Geol. Atlas U. S., U.S. Geol. Survey, 

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393. ---Geology of the Yellowstone Park: Mon. U. S. Geol. Survey, vol. 32, pt. 2, Chapter I, Geology of the 

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.. 
BIBLIOGRAPHY. 851 

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395. Hall, C. W., and Sardeson, F. W., The Magnesian series of the Northwestern States: Dull. Geol. Soc. America, 

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396. Hall, James, Geology of New York, part 4, Geology of the fourth district, Albany, 1843, pp. 151-153; (a) pp. 

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408. Harris, G. D., and Veatch, A. C., Preliminary report on the geology of Louisiana: Louisiana Geol. Survey, 

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416. Hayes, C. W., An expedition through the Yukon district: Nat. Geog. Mag., vol. 4, 1892, p. 140. 

417. --Geology of northeastern Alabama: Bull. Alabama Geol. Survey No.4, 1892, p. 31. 

418. ---Geology of a portion of the Coosa Valley in Georgia and Alabama: Bull. Geol. Soc. America, vol. 5, 1894, 

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419. --Ringgold folio (~o. 2), Geol. Atlas U. S., U. S. Geol. Survey, 1894. 

420. ---Kingston folio (~o. 4), Geol. Atlas U. S., U. S. Geol. Survey, 1894; (a) columnar sections. 

421. ---- -Chattanooga folio (No.6), Geol. Atlas U.S., "G. S. Geol. Survey, 1894. 

422. ---Sewanee folio (No.8), Geol. Atlas U. S., U. S. Geol. Survey, 1894. 

423. -~Stevenson folio (No. 19), Geol. Atlas U. S., U. S. Geol. Survey, 1895. 

424. ---Cleveland folio (No. 20), Geol. Atlas U. S., U. S. Geol. Survey, 1895; (a) columnar sections. 

425. ---Pikeville folio (No. 21), Geol. Atlas U. S., U. S. Geol. Survey, 1895. 

426. ---Gadsden folio (.~o. 35), Geol. Atlas U.S., U. S. Geol. Survey, 1896. 

427. ---Geology and physiography of the Nicaragua Canal route: Rept. Nicaragua.Canal Commission, 1897-1899, 

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428. ---Rome folio (No. 78), Geol. Atlas U.S., U.S. Geol. Survey, 1902; (a) pp. 2-3; (b) p. 2. 

429. Hayes, C. W., and Eckel, E. C., Iron ores of the Cartersville district, Georgia: Bull. U. S. Geol. Survey No. 

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430. Hayes, C. W., and Kennedy, William, Oil fields of the Texas-Louisiana Gulf Coastal Plain: Bull. U.S. Geol. 

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431. Hayes, C. W., and Ulrich, E. 0., Columbia folio (No. 95), Geol. Atlas U. S., U. S. Geol. Survey, 1903; (a) 

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432. Heilpri.n, Angelo, Wyoming Valley limestone beds: Ann. Rept. Second Geol. Survey Pennsylvania for 1885, 

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852 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

433. Heilprin, Angelo, Geological researches in Yucatan: Proc. Acad. Nat. Sci. Philadelphia, 1891, 1892, pp. 140, 

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434. Henderson, Junius, Red beds of northern Colorado: Jour. Geology, vol. 16, 1901), pp. 491--492. 

435. Hershey, 0. H., Metamorphic formations of northwestern California: Am. Geologist, vol. 27, 1901, p. 225. 

436. --- Neocene deposits of the Klamath region, California: Jour. Geology, vol. 10, 1902, pp. 377-392. 

437. Hettner, Alfred, Die Kordillere von Bogota: Petermanns Mitt., Erganzungsband 22, No. 104, 1892, pp. 15-16; 

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438. Hilgard, E. W., Report on the geology and agriculture ol Mississippi, Jackson, 1860; (a) pp. 60-95; (b) p. 61; 

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439. ---On the geological history of the Gulf of Mexico: Am. Jour. Sci., 3d ser., vol. 2, 1871, pp. 391--404. 

440. ---Am. Geologist, vol. 8, 1891, p. 130. 

441. Hill, R. T., Outlying areas of the Comanche series in Kansas, Oklahoma, and New Mexico: Am. Jour. Sci., 

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442. ---Porto Rico: Nat. Geog. Mag., vol. 10, 1899, pp. 108, 110. 

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444. ---Cuba and Porto Rico, with the•other islands of the "\Vest Indies, 'The Century Company, New York, 1899, 

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445. ---Geography and geology of the Black and Grand Prairies, Texas: Twenty-first Ann. Rept. U. S. Geol. 

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446. Hill, R. T., and Vaughan, T. W., Geology of portions of the Edwards Plateau and Rio Grande Plain adjacent 

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447. Hills, R. C., Note on the occurrence of fossils in the Triassic-Jurassic beds near San Miguel, Colorado: Am. 

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448. ---Recently discovered Tertiary beds of the Huerfano basin: Proc. Colorado Sci. Soc., vol. 3, 1888, pp. 

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449. --- Remarks on the classification of the Huerfano Eocene: Proc. Colorado Sci. Soc., vol. 4, 1891, pp. 7-9. 

450. --Elmoro folio (No. 58), Geol. Atlas U. S., U. S. Geol. Survey, 1899. 

451. --Spanish Peaks folio (No. 71), Geol. Atlas U.S., U.S. Geol. Survey, 1901; (a) pp. 1, 2; (b) p. 2. 

452. Hitchcock, C. H., Geology of New Hampshire, Jour. Geology, vol. 4, 1896, p. 59. 

453. --- Paleozoic terranes in the Connecticut Valley: Abstract Bull. Geol. Soc. America, vol. 7, 1896, pp. 510--512. 

454. ---Geology of Littleton, N.H., Cambridge, 1905 (reprinted from History of Littleton), p. 14; (a) p. 16. 

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456. ----The Newark system of the Pomperaug Valley, Connecticut: Twenty-first Ann. Rept. "C. S. Geol. Survey, 

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457. Hollick, Arthur, Preliminary contribution to our knowledge of the Cretaceous formation on Long Island and 

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458. ---Observations on the geology and botany of Marthas Vineyard: Trans. New York Acad. Sci., vol. 13, 1894, 

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459. --Geological notes: Long Island and Block Island: Trans. New York Acad. Sci., vol. 16, 1898, pp. 9-18. 

460. ---The Cretaceous flora of southern New York and New England: Mon. U. S. Geol. Survey, vol. 50, 1906, 

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461. Honeyman, D., Geology of Arisaig, Nova Scotia: Quart. Jour. Geol. Soc. London, vol. 20, 1864, pp. 333-345, and 

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462. Hopkins, T. C., Carboniferous sandstones of western Indiana: Twentieth Ann. Rept. Indiana Dept. Geol. and 

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464. Hopkins, T. C., and Siebenthal, C. E., Bedford oolitic limestone of Indiana: Twenty-fir~t Ann. Rept. Indiana 

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465. Howe, Ernest, Geology of the [Panama] Canal Zone: Ann. Rept. Isthmian Canal Comm. for 1907 (60th Cong., 

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467. Hyatt, Alpheus, Jura and Trias at Taylorsville, Cal.: Dull. Geol. Soc. America, vol. 3, 1892, pp. 395--412. 

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469. Hyatt, Alpheus, and Smith, J.P., The Triassic cephalopod genera of America: Prof. Paper U.S. Geol. Survey 

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470. Ingall, E. D., Ann. Rept. for 1902, section of mines: Ann. Rept. Geol. Survey Canada, new ser., vol. 15, 1906, 

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501. ---Devonian fauna of the Ouray limestone: Bull. U.S. Geol. Survey No. 391, 1909, pp. 1-60, Pls. I-X. 

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507. Knowlton, F. H., Tacoma folio (No. 54), Geol. Atlas U. S., U. S. Geol. Survey, 1899, p. 3. 

508. ---The stratigraphic relations and paleontology of the "Hell Creek beds," "Cera tops beds" and equivalents: 

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509. ---The Jurassic age of the "Jurassic flora of Oregon": Am . .Tour. Sci., 4th ser., vol. 30, 1910, pp. 33-34, 63-64. 

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511. Kfunmel, H. B., Newark rocks of New Jersey and New York: Jour. Geology, vol. 7, 1899, pp. 23-52; (a) p. 44; 

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512. ---Cambro-Ordovician rocks of Warren and Sussex counties: Ann. Rept. State Geologist for 1900, Geol. 

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854 INDEX TO THE STRATIGRAPHY OF NORTH Ac"\1ERICA. 

513. Kiimmel, H. B., Geological section of New Jersey: Jour. Geology, vol. 17, 1909, pp. 354-355; (a) pp. 355-356; 

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514. Lane, A. C., Suggestion from the State geologist: Michigan Miner, vol. 3, No. 10, 1901, p. 9. 

516. ---Northern Interior coal field: Twenty-second Ann. Rept. U.S. Geol. Survey, pt. 3,1902, p. 315; (a) p. 316. 

516. ---Coal of Michigan: Geol. Survey "'Iichigan, vol. 8, pt. 2, 1902, pp. 42-47; (a) p. 143. 

517. --Notes on the geological section of Michigan, part 2: Jour. Geology, vol. 18, 1910, pp. 393-429; (a) p. 414; 

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518. Lane, A. C., and others, Nomenclature and subdivision of the upper Siluric strata of Michigan, Ohio, and 

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519. Lane, A. C., and Seaman, A. E., Notes on the geological section of Michigan: Tenth Ann. Rept. State Geologist for 1908, 1909, pp. 21-120; (a) opp. p. 42; (b) pp. 74-75; (c) p. 76; (d) pp. 79-80; (e) p. 80; (f) p. 83; 

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520. Langdon, D. W., jr., Variations in the Cretaceous and Tertiary strata of Alabama: Bull. Geol. Soc. America, 

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521. Lapworth, Charles, Preliminary report on some graptolites from the lower Paleozoic: Trans. Royal Soc. 

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524. Lawson, A. C., Geology of the San Francisco Peninsula: Fifteenth Ann. Rept. U.S. Geol. Survey, 1895, p. 416. 

525. ---Geological section of the Middle Coast Ranges of California: Bull. Geol. Soc. America, vol. 13, 1902, 

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526. Leach, W. W., Crows Nest coal fields: Ann. Rept. Geol. Survey Canada, new ser., vol. 14, 1901, p. 74 A. 

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528. Lee, W. T., Red Bods of the Rio Grande region in central New Mexico: Jour. Geology, vol. 15, 1907, p. 55; 

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529. ---Unconformity in the so-called Laramie of the Raton coal field, New Mexico: Bull. Geol. Soc. America, 

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530. ---The Grand Mesa coal field, Colorado: Bull. U.S. Geol. Survey No. 341, 1909, pp. 320-321; (a) pp. 316, 320. 

531. Lees, J. H., General section of the Des Moines stage of Iowa: Ann. Rept. Iowa Gool. Survey, vol. 19, 1909, 

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532. Le·onard, A. G., Topographic features and geological formations of North Dakota: Third Biennial Rept. Geol. 

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533. ---The Cretaceous and Tertiary formations of western North Dakota and eastern Montana: Jour. Geology, 

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534. Leonard, A. G., and Smith, C. D., Sentinel Butte lignite field, North Dakota and Montana: Bull. 'C. S. Geol. 

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535. Lesley, J. P., A summary description of the geology of Pennsylvania: Summary Rept. Goo!. Survey Pennsylvania, vol. 1, 1892, pp. 625-718; vol. 2, 1892, pp. 721-875, 989-1033; (a) vol. 2, p. 787. 

536. Lindgren, Waldemar, Notes on the geology of Baja California, Mexico: Proc. California Acad. Sci., 2d ser., 

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537. ---Mining districts of the Idaho Basin and Boise Ridge, Idaho, with report on fossil plants of the Payette 

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539. ---Gold and silver veins of Silver City, De Lamar, and other mining districts, Idaho: Twentieth Ann. Rept. 

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540. ---Gold belt of the Blue Mountains of Oregon: Twenty-second Ann. Rept. U. S. Geol. Survey, pt. 2, 1901, 

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541. ---Copper deposits of the Clifton-Morenci district, Arizona: Prof. Paper U. S. Geol. Survey No. 43, 1905; 

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542. Lindgren, Waldemar, Graton, L. C., and Gordon, C. H., Ore deposits of New Mexico: Prof. Paper U. S. 

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576. Martin, K., Geologische Studien tiber Niederlacndisch West-Indien: Scparatausgabe des zweiten 'fheib; 

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577. Marvine, A. R., Report of Middle Park division: Ann. Hept. U.S. Geol. and Geog. Survey Terr. for 1873, 

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578. Mather, W. W., Geology of Kew York, part 1 (comprising the survey of the first geological district), Albany, 

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579. Mathews, E. B., Correlation of Maryland and Pennsylvania Piedmont formations: Bull. Geol. Soc. America, 

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580. Matson, G. C., and Clapp, F. G., A preliminary report on the geology of Florida: Second Ann. Rept. Florida 

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(d) pp. 108-110; (e) pp. 114-116; (f) p. 124; (g) p. 129, 124; (h) p. 134; (i) pp. 138-139. 

581. Matthew, G. F., Heport on the Cambrian rocks of Cape Breton: Geol. Survey Canada, 1903, pp. 67-60. 
856 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

582. Matthew, G. F., Physical aspect of the Cambrian rocks in eastern Canada, with a catalogue of organic remains 

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583. Maury, C. J., A compari~on of the Oligocene of western Europe and the southern United States: Bull. Am. 

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584. Meek, F. B., .Fossils from Kennedy Channel: Am. Jour. Sci., 2d ser., vol. 40, 1865, p. 34. 

585. --- Remarks on the geology of the valley of the Mackenzie River, with figures and descriptions of fossils, 

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586. Meek, F. B., and Hayden, F. V., Descriptions of ... fossils ... collected in Nebraska: Proc. Acad. Nat. 

Sci. Philadelphia, vol. 13, 1862, p. 419; (a) p. 433. 

587. Mendenhall, W. C., Reconnaissance in the Norton Bay region, Alaska: Special publication U.S. Geol. Survey, 

1901, p. 214. 

588. ---Reconnaissance from .Fort Hamlin to Kotzebue Sound, Alaska: Prof. Paper U. S. Geol. Survey No. JO, 

1902, pp. 41-42. 

589. Merriam, J. C., A geological section through the John Day Basin: Abstract, Jour. Geology, vol. 9, 1901, p. 71. 

590. ---A contribution to the geology of the John Day Basin: Bull. Dept. Geology Univ. California, vol. 2, 1901, 

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591. Merriam, J. C., and Sinclair, W. J., Tertiary faunas of the John Day region: Bull. Dept. Geology Univ. California, vol. 5, 1907, p. 173. 

592. Merrill, F. J. H., Description of the State geologic map of 1901: Bull. New York State :Mus. No. 56, 1902; (a) 

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593. Merrill, F. J. H., and others, New York City folio (No. 83), Geol. Atlas U. S., U. S. Geol. Survey, 1902. 

594. Mierisch, Bruno, Eine Reise querdurch Nicaragua: Petermanns Mitt., vol. 41, 1895, pp. 61-62. 

595. Miller, B. L., Dover folio (No. 137), Geol. Atlas U. S., U. S. Geol. Survey, 1906. 

596. ---Erosion intervals in the Tertiary of North Carolina and Virginia: Bull. Geol. Soc. America, yol. 20, 1910, 

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597. --Choptank folio (No. 182), Geol. Atlas U.S., U.S. Geol. Survey, 1912. 

598. Moffit, F. H., .Fairhaven gold placers, Seward Peninsula, Alaska: Bull. U.S. Geol. Survey .'Jo. 247,1905, p. 25. 

599. Moffit, F. H., and Capps, S. R., Geology and .Mineral resources of the Nizina region, Alaska: Bull. U.S. Geol. 

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600. Moffit, F. H., and Knopf, Adolph, Mineral resources of the Nabesna-White River district, Alaska: Bull. U.S. 

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601. Moffit, F. H., and Maddren, A. G., Mineral resources of Kotsina-Chitina region, Alaska: Bull. U. S. Geol. 

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602. Moffit, F. H., and Stone, R. W., Mineral resources of Kenai Peninsula, Alaska: Bull. U. S. Geol. Survey No. 

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603. Mojsisovics, Edmund von, Vorlage des Werkes '' Arktische Trias faunen": Verhandl. K.-k. geol. Reichsanstalt 

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605. Morse, W. C., and Foerste, A. F., The \Vaverly formations of east-central Kentucky: Jour. Geology, vol. 17, 

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606. Morton, S. G., Synopsis of organic remains of the Cretaceous group of the United States, Philadelphia, 1834. 

607. Munn, M. J., Sewickley folio (No. 176), Geol. Atlas U.S., U.S. Geol. Survey, 1911. 

608. Murray, Alexander, Geological Survey of Newfoundland (reprint of reports) 1881, pp. 35-36, 3HO; (a) pp. 

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609. Nathorst, A. G., Didrag till nordiistra Griinlands geologi: .Fiirhandl. Geol. .Fiiren. Stockholm, No. 207, vol. 23, 

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610. Newberry, J. S., A Cretaceous flora of North America: Trans. New York Acad. Sci., vol. 5, 1886, pp. 133-137. 

611. ---.Flora of the Amboy clays: Bull. Torrey Bot. Club, vol. 13, 1886, pp. 33-37. 

612. ---Triassic plants from Honduras: Trans. New York Acad. Sci., vol. 7, 1888, p. 113. 

613. ---Rhmtic plants from Honduras: Am. Jour. Sci., 3d ser., vol. 36, 1888, p. 342. 

614. ---.Flora of the Amboy clays: Mon. U.S. Geol. Survey, vol. 26, 1895 (a posthumous work, edited by Arthur 

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615. Newsom, J. F., Geologic and topographic section across southern Indiana: Twenty-sixth Ann. Rept. Indiana 

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616. Nickles, J. M., Bibliography of North American geology for 1908; Bull. U. S. Geol. Survey No. 409, 1909. 

617. ---Bibliography of North American geology for 1909, with subject index: Bull. U.S. Geol. Survey No. 

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618. Nicolas, F. J., General index to reports 1885-1906: Geol. Survey Canada, Ottawa, 1908; (a) consult under 

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619. O'Harra, C. C., Geology of Allegany County, Maryland Geol. Survey, 1900, pp. 57-164. 

620. Orton, Edward, Geology of the Cincinnati group: Geol. Survey, Ohio, vol. 1, pt. 1, 1873, pp. 370-373. 

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633. Penrose, R. A. F., jr., Preliminary report on the geology of the Gu.w' Tertiaries of Texas: First Arn1. Rept. 

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634. Perry, J. H., and Emerson, B. K., Geology of Worcester, Mass., Worcester Nat. Hist. Soc., 1903, pp. 152-158. 

635. Phalen, W. C., Economic geology of the Kenova quadrangle, Kentucky, Ohio, and \Vest Virginia: Bull U.S. 

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636. --- Coal resources of the Pikeville special quadrangle: Bull. Geol. Survey Tennessee, No. 9, 1911. 

637. Platt, Franklin, Report of progress in Clearfield and Jefferson districts of bituminous coal fields of western 

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638. Powell, J. W., Report on the geology of the eastern Uinta Mountains: U.S. Geol. and Geog. Survey Terr., 1876. 

639. Prindle, L. M., Bonnifield and Kantishna regions, Alaska: Bull. U.S. Geol. Survey No. 314, 1907, pp. 221-222. 

640. ---The Fairbanks and Rampart quadrangles, Alaska: Bull. U. S. Geol. Survey No. 337, 1908, pp. 23-24. 

641. Prindle, L. M., and Hess, F. L., The Rampart gold-placer region: Bull. U.S. Geol. Survey No. 280, 1906, p. 22. 

642. Prosser, C. S., Thickness of the Devonian and Silurian rocks of central New York: Bull. Geol. Soc. America, 

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643. ---The classification and distribution of Hamilton and Chemung series of central and eastern New York, 

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645. ---Waverly series of central Ohio: Jour. Geology, vol. 9, 1901, pp. 205-231. 

646. ---Paleozoic formations of Allegany County, Md.: Jour. Geology, vol. 9, 1901, pp. 410--414; (a) pp. 415--422. 

647. ---Notes on stratigraphy of Mohawk Valley and Saratoga County, N.Y.: Bull. New York State Mus. No. 34. 

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o648. ---Revised classification of the upper Paleozoic formations of Kansas: Jour. Geology, vol. 10, 1902, pp. 703-

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649. ---The nomenclature of the Ohio geological formations: Jour. Geology, vol. 11, 1903, pp. 519-546; (a) p. 521. 

650. ---Romney formation of Maryland: Jour. Geology, vol. 12, 1904, pp. 361-372. 

651. ----Revised nomenclature of the Ohio geological formations: Bull. Geol. Survey Ohio, 4th ser., No.7, 1905. 

652. Prosser, C. S., and Cunings, E. R., Sections and thickness of the Lower Silurian formations on West Canada 

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653. Pugh, G. T., Pleistocene deposits of South Carolina, Press of the State Company, Columbia, S. C., 1905. 

654. Pumpelly, Raphael, Geology of the Green Mountains in Massachusetts: Mon. U. S. Geol. Survey, vol. 23, 

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655. Purdue, A. H., The slates of Arkansas: Geol. Survey Arkansas, 1909, pp. 30--40, 45--46; (a) p. 48. 

656. Purdue, A. H., and Adams, G. I., Winslow folio (No. 154), Geol. Atlas U. S., U. S. Geol. Survey, 1907. 

657. Ransome, F. L., Geology of the Globe copper district, Arizona: Prof. Paper U. S. Goo!. Survey No. 12, 1903, 

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658. ---Geology and ore deposits of the Bisbee quadrangle: Prof. Paper U. S. Geol. Survey No. 21, 1904, pp. 

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659. ---Geology of the Globe district; Min. and Sci. Press, vol. 102, 1911, p. 747. 

660. Raymond, P. E., Fauna of the Chazy limestone: Am. Jour. Sci., 4th ser., vol. 20, 1905, pp. 353-382. 

661. ---Trilobites of the Chazy limestone: Annals Carnegie Mus., vol. 3, 1905, pp. 328-386. 

662. ---On the occurrence in the Rocky Mountains of an Upper Devonian fauna with Clymenia: Am. Jour. Sci., 

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858 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

663. Reagan, A B., Geology of the Fort Apa<'he regw~ m Anzona Am Geologist, vol 32, 1!103, p 278; (a) p 279. 

664. --- Noteo on the OlymplC Penmsub Trano Kanoas Acad Sci , vol 22, 1909, pp 158-159 

665 R1chards, R. W, The central part of the Bull Mountam coal field, Montana Bull U S Geol. Survey No 381, 

1910, pp ()0-81 

666 Richardson, G. B , Reconnaissanee m trans-Pecos Texas Bull Texas Umv Mm Survey No 9 (23), 1904, 

pp 43--45, (a) pp 46--48 

667 ~~Book Chffs coal field Bull U S Geol Survey No 316, 1907, pp 304-305 

668 ---Paleozoic fo1mat10ns in ttans-Pecos Texas Am Jour Sci, 4th ser, vol 25, 1908, pp 475--478, (a) pp 

478--479, (b) pp 479--480, (e) pp 480--483 

669 ---The Harmony, Colob, and Kanab coal fields, southern Utah Bull U S Geol Survey No 341, 1909, 

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670. ---Stratigraphy of the uppe:· Catbomferous m We&t Texas and southeast New Mexi<'O Am Jour Set, 4th 

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671. Richardson, James, Report on coal fields of Vancouver ancl Queen Charlotte Islands Rept Progress for 1872-

73, Gcol Survey Canada, 1873, pp 32-65, (a) pp 84-86 

672 R1es, Hemnch, Geology ot Orange County Fliteenth Ann Rept of State Geologist, for 1895, Geol Survey 

New York, vol 1, 1897, pp 395--475 

673 --- Geology of Orange County Forty-mnth Ann Rept New York State Mus for 1895, 1898, pp 400-401 

674. Rogers, H. D., Geology of Pennsylvama, vol 2, Ph1ladelphm, 1858, pp 749-758 

675 Rogers, W. B , Proofs of the Protozo1c age ot some' of the altered rocks of eastern Mas~achusetts from fossils 

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676. ---Geology of the Vugnuas, 1835-1841, New York, 1884, (a) pp 209-217, 230, 717 

677 Rommger, C-; Paleozoic rocks Geol Smvey MlChigan, vol 1, 1869-1873 (1873), p 37; (a) pp 50-77 

678 Ruedemann, Rudolph, Hudson RIVer beds near Albany and theu taxonomic eqmvalents Bull New York 

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679 ---Trenton conglomerate of Rysedorph Htll and 1ts fauna Bull New York State Mus No 49, 1901, pp. 

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680 ---Graptolites of New York, part 1, Graptolites of the lower beds Mem New York State Mus No 7, 1904 

681. --- Giaptolites of New York, part 2, Graptolites of the higher beds Mem. New York State Mus No 11, 

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682 Ruffin, Edmund, Report of the commencement and pwgress of the agncultural survey of South Carolina for 

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683 Russell, I C, CorrelatiOn papers-The Newark system Bull U S Geol Survey No 85, 1892 

684. ---A geologu·al reconnaissance m central Washmgton Bull U S Geol Survey No 108, 1893', p 22, (a) 

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685 ---A reconnaissance m southeastern \Vashmgton Water-Supply Paper U S Geol Survey No 4, 1897, p 55 

686 --- PICliminary report on geology and water resources of central Oregon Bull U S Geol Survey No 252, 

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687. Safford, J. M., Geology of Tennessee, NashVIlle, 1869, (a) pp 338-365, (b) pp 383-398, (c) pp 410--421 

688 ---On the Cretaceous and supenor formatiOns of West Tennessee Am Jour SCI, 2d ser, vol 37, 1864, 

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689. ---Class1ficat10n of geological formatwns of Tennessee Bull Geol Soc Amenca, vol 13, 1901, p 11 

690 Safford, J. M., and Killebrew, J. B., The elements of the geology of TenneRRee, NashVIlle, 1900, p 153 

691 Salisbury, R D, Ann Rcpt State Geologist of New Jmsey for 1893 Geol Survey New Jpr~ey, 1894, also later 

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692 Salter, J. W, Arctrc Stlunan fossrls Quart Jour Geol Soc London, vol 9, 1853, pp 312-317 

693 Sanford, Samuel, Topography and geology of southern Flonda Second Ann Rept Flonda State Gcol Survey, 

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694. Sapper, Carl, La geografia fisica y Ia geologia de la peninsula de Yucatan Bol Inst. geol Mexico, No 3, 1896, 

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695 ---Die Alta Verapaz (Guatemala) Mitt Geog Gesell Ilamburg, vol 17, 1901, p 85, (a) pp 87-88 

696 --- Uber Gebugsbau und Boden des sudlichen ~httelamenka Petermanns Mttt , Erg.1nzungsb.1nd 32, 1906, 

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697 --- Gmndzuge der physikalischen Geographre von Guatemala PetCimanns Mitt , Erganzungs-band 24, 

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698 --- Uher Gebirgsbau und Boden des nordhchen l\Ilttebmenka Petermanns Mitt, Erganzungsbancl 27, 

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699 Sardeson, F. W, Fauna of the Magnesian senes Bull Mmncsota Acad Nat Sci, vol 4, No 1, pt 1, 1896, 

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701 Savage, T. E , Geology of Tama County Ann Rept Iowa Geol Survey, vol 13, 1903, pp 228-229 
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777. Stanton, T. W., Faunal relations of the Eocene and Upper Cretaceous on the Pacific coast: Seventeenth Ann. 

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778. ---Lower Cretaceous formations and faunas of the United States: Jour. Geology, vol. 5, 1897, pp. 594-599. 

779. ---1Iesozoic fossils: Mon. l~. S. Geol. Survey, vol 32, pt. 2, 1899, pp. 604-607. 

780. ---Review of paper on area near Orizaba, State of \-era Cruz, by Emilio Biise: Am. Geologist, vol. 2.5, 1900, 

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781. ---The Morrison formation: Jour. Geology, vol. 13, 1905, pp. 657-669; (a) p. 663; (b) p. 665. 

782. ---Later Mesozoic invertebrate faunas in North America: Jour. Geology, vol. 17, 1909, pp. 410-412; (a) 

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783. --- Age and stratigraphic relations of the "Ceratops beds" of Wyoming and Montana: Proc. \Vashington 

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784. ----Fox Hills sandstone and Lance formation ("Ceratops beds") in South Dakota, North Dakota and eastern 

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785. Stanton, T. W., and Hatcher, J. B., Geology and paleontology of the Judith River beds, with a chapter on 

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786. Stanton,-T. W., and Martin, G. C., Mesozoic section on Cook Inlet: Bull. Geol. Soc. America, vol. 16, 1905, 

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787. Stanton, T. W., and Vaughan, T. W., Section of the Cretaceous at El Paso, Texas: Am. Jour. Sci., 4th ser., 

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788. Stauffer, C. R., Hamilton in Ohio: Jour. Geology, vol. 15, 1907, pp. 590-.596. 

789. --- Devonian section on Ten Mile Creek, Lucas County, Ohio: Ohio Naturalist, vol. 8, 1908, pp. 271-276. 

790. ----The Middle Devonian of Ohio: Bull. Geol. Survey Ohio, 4th ser., No. 10, 1909, pp. 25-27. 

791. Stephenson, L. W., Some facts relating to the Mesozoic deposits of the Coastal Plain of North Carolina: Johns 

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798. Stone, R. W., Coal near the Crazy Mountains, Montana: Bull. U. S. Geol. Survey No. 341, 1909, pp. 76-80. 

799. Stone, R. W., and Calvert, W. R., Stratigraphic relations of Livingston formation of Montana: Econ. Geology, 

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801. ---Cambro-Ordovician limestones of the Appalachian Valley in southern Pennsylvania: Jour. Geology, vol. 

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803. ---Pawpaw-Hancock folio (No. 179), Geol. Atlas U.S., U. S. Geol. Survey, 1912. 

804. Suess, Edward, Face de la terre, map of eastern Siberia by E. de Toll, 1897, vol. 3, p. 29; also in Petermanns 

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805. Swartz, C. K., Portage and Chemung formations of Maryland: Jour. Geology, vol. 16, 1908, pp. 328-346. 

806. Taff, J. A., Atoka folio (No. 79), Geol. Atlas U.S., U.S. Geol. Survey, 1902. 

807. ---Southwestern coal field: Twenty-second Ann. Rept. U. S. Geol. Survey, pt. 3, 1902, p. 402. 

808. ---Geology of the Arbuckle and Wichita mountains, with faunal correlations by E. 0. Ulrich: Prof. Paper 

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810. Taff, J. A., and Brooks, A. H., Buckhannon folio (No. 34), Geol. Atlas U. S., U. S. Geol. Survey, 1896. 

811. Tuomey, Michael, Geology of South Carolina, Columbia, ttl. C., 1848, pp. 132-139. 

812. ---First biennial report on the geology of Alabama: Tuscaloosa, 1858. 

813. Turner, H. W., Bidwell Bar folio (No. 43), Geol. Atlas U. S., U. S. Geol. Survey, 1898, p. 1. 

814. ---The Esmeralda formation: Am. Geologist, vol. 25, 1900, pp. 168-170. 

815. Turner, H. W., and Ransome, F. L., Sonora folio (No. 41), Geol. Atlas U. S., U. S. Geol. Survey, 1897, p. 1. 

816. Tyrrell, J. B., Report on northern Alberta: Ann. Rept. Geol. Survey Canada, new ser., vol. 2, 1887, pp. 127-

139 E; (a) pp. 131-136 E. 

817. ---Report on northwestern Manitoba, with portions of the districts of Assiniboia and Saskatchewan: Ann. 

Rept. Geol. Survey Canada, new ser., vol. 5,1893, pp. 199, 204-209 E; (a) pp. 200-203 E; (b) pp. 209-215 E. 

818. --- Doobaunt, Kazan, and Ferguson rivers: Ann. Rept. Geol. Survey Canada, new ser., vol. 9, 1898, p. 91 F. 
860 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

738. Sherzer, W. H., and Grabau, A. W., New upper Siluric fauna from southern Michigan: Bull. Geol. Soc. 

America, vol. 19, 1909, pp. 540-553; (a) p. 551; (b) pp. 552-553. 

739. Shimer, H. W., A lower-middle Cambrian transition fauna from Braintree, Mass.: Am. Jour. Sci., 4th ser., 

vol. 24, 1907, p. 176. 

740. Shimer, H. W., and Grabau, A. W., Hamilton group of Thedford, Ontario: Bull. Geol. Soc. America, vol. 13, 

1902, pp. 149-186. 

741. Sievers, W., Die Cordillere von Merida: Geog. Abhandl., vol. 3, No. 1, 1889, pp. 8-16; (a) pp. 16-26; (b) 

pp. 26, 27. 

742. Skeat, E. G., Jurassic rocks of East Greenland: l'roc. Geologists Assoc., London, 1904, pp. 336-350. 

743. Sloan, Earle, Geology and mineral resources (in Handbook of South Carolina): State Dept. of Agriculture, 

Commerce, and Irrigation, 1907, pp. 85-88; (a) pp. 86-88. 

744. ---Catalogue of the minerallocalitics of Sonth Carolina: Bull. South Carolina Geol. Survey, 4th ser., No. 2, 

1908; (a) p. 3GO; (b) pp. 438-442,; (c) pp. 442-444; (d) pp. 453-462; (e) pp. 462-464. 

745. Smith, A. D, W., The Anthracite region: Summary Final Rept. Geol. Survey Pennsylvania, vol. 3, pt. 1, 

189.5, pp. 1916-2152; (a) p. 1918; (b) p. 1922. 

746. Smith, E. A., Geological map and explanatory chart of Alabama: Geol. Survey Alabama, 1894. 

747. ---Carboniferous fossils in "Ocoee" slates in Alabama; Science, new ser., vol. 18, 1903, pp. 244-246. 

748. ---Portland cement materials of Alabama: Bull. U. S. Geol. Survey No. 243, 1905, p. 60. 

749. ---The underground water resources of Alabama: Bull. Alabama Geol. Survey, 1907, pp. 15-19; (a) pp. 16, 

17; (b) pp. 17-18; (c) p. 18; (d) p. 19. 

750. Smith, E. A., and Johnson, L. C., Tertiary and Cretaceous strata of the Tuscaloosa, Tombigbee, and Alabama rivers: Bull. U.S. Geol. Survey No. 43, 1887; (a) pp. 71-138. 

751. Smith, E. A., Johnson, L. C., and Langdon, D. W., Geology of Coastal Plain of Alabama: Geol. Survey 

Alabama, 1894; (a) pp. 255-373, 422-445; (b) pp. 276-289. 

752. Smith, E. E., The eastern part of the Great Divide coal field, Wyoming: Bull. U. S. Geol. Survey No. 341, 

1909, pp. 220-224; (a) pp. 223, 225. 

753. Smith, G. L., The Carboniferous section of southwestern Iowa: Ann. Rcpt. Iowa Geol. Survey, 1909, vol. 19, 

p. 611. 

754. Smith, G. 0., Pacific coast coal fields: Twenty-second Ann. Rept. U.S. Geol. Survey, pt. 3, 1902, pp. 483-489. 

755. --Ellensburg folio (No. 86), Geol. Atlas U. S., U. S. Geol. Survey, 1903. 

756. --Mount Stuart folio (No. 106), Geol. Atlas U. S., U. S. Geol. Survey, 1904, pp. 5-7. 

757. Smith, G. 0., and Calkins, F. C., A geological reconnaissance across the Cascade range near the forty-ninth 

parallel: Bull. U. S. Geol. Survey No. 235, 1904, p. 27; (a) pp. 28-29. 

758. --Snoqualmie folio (No. 139), Geol. Atlas U. S., U.S. Geol. Survey, 1906; (a) pp. 4-5. 

759. Smith, G. 0., and White, David, Geology of the Perry Basin in southeastern Maine: Prof. Paper U. S. Geol. 

Survey No. 35, 1905, p. 28; (a) pp. 83-84. 

760. Smith, G. 0., and others, Penobscot Bay folio (No. 149), Geol. Atlas U.S., U.S. Geol. Survey, 1907; (a) p. 12. 

761. Smith, J. H., Eocene of North America west of the one hundredth meridian: Jour. Geology, vol. 8, 1900, pp. 

448-449. 

762. Smith, J.P., Metamorphic series of Shasta County, Cal.: Jour. Geology, vol. 2, 1894, pp. 592-601; (a) p. 601; 

(b) p. 604. 

763. ·--Age of the auriferous slates of the Sierra Nevada: Bull. Geol. Soc. America, vol. 5, 1894, pp. 243-258. 

764. --Comparative stratigraphy of the marine Trias of western America: Proc. California Acad. Sci., 3d ser., 

vol. 1, 1904, pp. 348-350; (a) pp. 35G-351; (b) p. 364. 

765. ---The stratigraphy of the western American Trias: Festschrift A. von Koenen, Stuttgart, 1907, pp. 377-434. 

766. --Salient events in the geologic history of California: Science, new ser., vol. 30, 1909, pp. 347-348. 

767. Smith, P. S., Geology and mineral resources of Solomon and Casadepaga quadrangles, Seward Peninsula, 

Alaska: Bull. U. S. Geol. Survey No. 433, pp. 22-26. 

768. Smith, P. S., and Eakin, H. M., Geologic reconnaissance in southeastern Seward Peninsula and the Norton 

Bay-Nulato region, Alaska: Bull. U.S. Geol. Survey No. 449, 1911, p. 48. 

769. Spencer, A. C., and others, Franklin Furnace folio (No.161), Geol. Atlas U.S., U.S. Geol. Survey, 1908, p. 11. 

770. Spurr, J. E., Geology of the Yukon gold district, Alaska: Eighteenth Ann. Rept. U. S. Geol. Survey, pt. 3, 

1898, pp. 196-197; (a) pp. 199-200. 

771. ·--Reconnaissance in southwestern Alaska: Twentieth Ann. Rept. U. S. Geol. Survey, pt. 7, 1900, p. 171; 

(a) pp. 173-174. 

772. ---Descriptive geology of Nevada south of the fortieth parallel: Bull. U. S. Geol. Survey No. 208, 1903; 

(a) pp. 189-191. 

773. Squire, Joseph, Report on the Cahaba coal field: Geol. Survey Alabama, 1890. 

774. Stanton, T. W., Stratigraphic position of the Bear River formation: Am. Jour. Sci., 3d ser., vol. 43, 1892, pp. 

98-115. 

775. ---The Colorado formation and its invertebrate fauna: Bull. U. S. Geol. Survey No. 106, 1893. 

776. --·- Contributions to the Cretaceous paleontology of the Pacific coast; The fauna of the Knoxville beds: 

Bull. U. S. Geol. Survey No. 133, 1895; (a) pp. 3G-3l. 
BIBLIOGRAPHY. 861 

777. Stanton, T. W., Faunal relations of the Eocene and Upper Cretaceous on the Pacific coast: Seventeenth Ann. 

Rept. U. S. Geol. Survey, pt. 1, 1896, pp. 1005-1037. 

778. ----Lower Cretaceous formations and faunas of the United States: Jour. Geology, vol. 5, 1897, pp. 594-599. 

779. ---Mesozoic fossils: Mon. U. S. Geol. Survey, vol 32, pt. 2, 1899, pp. 604-607. 

780. ----Review of paper on area near Orizaba, State of~-era Cruz, by Emilio Bose: Am. Geologist, vol. 25, 1900, 

p. 315. 

781. ----The ~Iorrison formation: Jour. Geology, vol. 13, Hl05, pp. 657-669; (a) p. 663; (b) p. 665. 

782. ---Later Mesozoic invertebrate faunas in North America: Jour. Geology, vol. 17, 1909, pp. 410--412; (a) 

pp. 418--419. 

783. ---Age and stratigraphic relations of the "Ceratops beds" of Wyoming and Montana: Proc. Washington 

Acad. Sci., vol. 11, 1909, pp. 239-293. 

784. --~ Fox Hills sandstone and Lance formation ("Cera tops beds") in South Dakota, North Dakota and eastern 

Wyoming: Am. Jour. Sci., 4th ser., vol. 30, 1910, pp. 172-188. 

785. Stanton, T. W., and Hatcher, J. B., Geology and paleontology of the Judith River beds, with a chapter on 

the fossil plants by F. II. Knowlton: Bull. U.S. Geol. Survey No. 257, 1905, pp. 11-14. 

786. Stanton,-T. W., and Martin, G. C., Mesozoic section on Cook Inlet: Bull. Geol. Soc. America, vol. 16, 1905, 

p. 393; (a) pp. 393-396; (b) pp. 409--410. 

787. Stanton, T. W., and Vaughan, T. W., Section of the Cretaceous at El Paso, Texas: Am. Jour. Sci., 4th ser., 

vol. 1, 1896, pp. 21-26. 

788. Stauffer, C. R., Hamilton in Ohio: Jour. Geology, vnl. 15, 1907, pp. 590-596. 

789. --- Devonian section on Ten Mile Creek, Lucas County, Ohio: Ohio Naturalist, vol. 8, 1908, pp. 271-276. 

790. ----The Middle Devonian of Ohio: Bull. Geol. Survey Ohio, 4th ser., No. 10, 1909, pp. 25-27. 

791. Stephenson, L. W., Some facts relating to the Mesozoic deposits of the Coastal Plain of North Carolina: Johns 

Hopkins Univ. Circ. No. 199, 1907, pp. 681-687. 

792. Stevens, R. P., Geological and mineralogical specimens collected by Mr. C. F. Hall in Frobisher Bay: Am. 

Jour. Sci., 2d ser., vol. 35, 1863, pp. 293-294. 

793. Stevenson, J. J., Fayette and Westmoreland district of bituminous coal fields of western Pennsylvania: Rept. 

Progress KK, Second Geol. Survey Pennsylvania, 1877, p. 31. 

794. ---Lower Carboniferous of the Appalachian basin: Bull. Geol. Soc. America, vol. 14, 1903, pp. 15--45; (a) 

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795. --Carboniferous of the Appalachian Basin: Bull. Geol. Soc. America, vol. 15, 1904, p. 38; (a) pp. 38-92; 

(b) p. 39; (c) pp. 39--40; (d) p. 42; (e) p. 89; (f) p. 109; (g) p. 125; (h) p. 143; (i) p. 151. 

796. ---Carboniferous of the Appalachian Basin: Bull. Geol. Soc. America, vol. 17, 1906, p. 44; (a) p. 65; (b) 

p. 66; (c) p. 74; (d) pp. 76, 124; (e) p. 78; (f) p. 80; (g) p. 154; (h) p. 216; (i) p. 222; (j) p. 228. 

797. ---Carboniferous of the Appalachian Basin: Bull. Geol. Soc. America, vol. 18, 1907, p. 30; (a) p. 41; (b) 

pp. 95-96; (c) pp. 171-173. 

798. Stone, R. W., Coal near the Crazy Mountains, Montana: Bull. U. S. Geol. Survey No. 341, 1909, pp. 76-80. 

799. Stone, R. W., and Calvert, W. R., Stratigraphic relations of Livingston formation of Montana: Econ. Geology, 

vol. 5, 1910, pp. 551-557, 652-669, 741-764. 

800. Stose, G. W., Sedimentary rocks of South Mountain, Pennsylvania: Jour. Geology, vol. 14, 1906, pp. 204--208. 

801. ---Cambro-Ordovician limestones of the Appalachian Valley in southern Pennsylvania: Jour. Geology, vol. 

Hi, 1908, pp. 698-714; (a) 698-704. 

802. ---Mercersburg-Chambersburg folio (No. 170), Geol. Atlas U.S., U.S. Geol. Survey, 1910; columnar section. 

803. --Pawpaw-Hancock folio (No. 179), Geol. Atlas U. S., U. S. Geol. Survey, 1912. 

804. Suess, Edward, Face de la terre, map of eastern Siberia by E. de Toll, 1897, vol. 3, p. 29; also in Petermanns 

Mitt., vol. 46, 1900, Pl. XIII. 

805. Swartz, C. K., Portage and Chemung formations of Maryland: Jour. Geology, vol. 16, 1908, pp. 328-346. 

806. Taff, J. A., Atoka folio (No. 79), Geol. Atlas U.S., U.S. Geol. Survey, 1902. 

807. ---Southwestern coal field: Twenty-second Ann. Rept. U.S. Geol. Survey, pt. 3, 1902, p. 402. 

808. ---Geology of the Arbuckle and Wichita mountains, with faunal correlations by E. 0. Ulrich: Prof. Paper 

U.S. Geol. Survey Xo. 31, 1904; pp. 21-22, 68-69; (a) pp. 23-27; (b) pp. 28-30; (c) pp. 31-33. 

809. ---The Sheridan coal field, Wyoming: Bull. U. S. Geol. Survey No. 341, 1909, pp. 123-150. 

810. Taff, J. A., and Brooks, A. H., Buckhannon folio (No. 34), Geol. Atlas U.S., U. S. Geol. Survey, 1896. 

811. Tuomey, Michael, Geology of South Carolina, Columbia,*l. C., 1848, pp. 132-139. 

812. ---First biennial report on the geology of Alabama: Tuscaloosa, 1858. 

813. Turner, H. W., Bidwell Bar folio (No. 43), Geol. Atlas U.S., U. S. Geol. Survey, 1898, p. l. 

814. ---The Esmeralda formation: Am. Geologist, vol. 25, 1900, pp. 168-170. 

815. Turner, H. W., and Ransome, F. L., Sonora folio (No. 41), Geol. Atlas U.S., U. S. Geol. Survey, 1897, p. 1. 

816. Tyrrell, J. B., Report on northern Alberta: Ann. Rept. Geol. Survey Canada, new ser., vol. 2, 1887, pp. 127-

139 E; (a) pp. 131-136 E. 

817. ---Report on northwestern Manitoba, with portions of the districts of Assiniboia and Saskatchewan: Ann. 

Rept. Geol. Survey Canada, new ser., vol. 5, 1893, pp. 199, 204-209 E; (a) pp. 200-203 E; (b) pp. 209-215 E. 

818. --- Doobaunt, Kazan, and Ferguson rivers: Ann. Rept. Geol. Survey Canada, new ser., vol. 9, 18()8, p. 911<'. 
862 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

819. Udden, J. A., A sketch of the geology of the Chisos country, Brewster County, Tex.: Bull. Texas Univ. Min. 

Survey No. 93, 1907; (a) pp. 18-19; (b) pp. 26-27. 

820. Ulrich, E. 0., Determination and correlat:on of formations of northern Arkansas: Prof. Paper U. S. Geol. Survey No. 24, 1904, correlation table opp. p. 90, pp. 90-98; revised for this manuscript by Mr. Ulrich, 1910. 

821. ---Revision of the Paleozoic systems: Bull. Geol. Soc. America, vol. 22, 1911, pp. 281-680. 

822. Ulrich, E. 0., and Cushing, H. P., Age and relations of the Little Falls dolomite (Calciferous) of the Mohawk 

Valley: Bull. New York State Mus. No. 140, 1910; (a) pp. 102-103. 

823. Ulrich, E. 0., and Schuchert, Charles, Paleozoic seas and barriers in eastern North America: Bull. New 

York State Mus. ~o. 52, 1902, p. 639. 

824. Ulrich, E. 0., and Smith, W. S. T., The lead, zinc, and fluorspar deposits of western Kentucky: Prof. Paper 

U. S. Geol. Survey No. 36, 1905, p. 24. 

825. Umpleby, J. B., Geology and ore deposits of Republic mining district: Bull. Washington Geol. Survey Ko. 1, 

1910, pp. 15-17. 

826. VanHise, C. R., The problem of the pre-Cambrian: Bull. Geol. Soc. America, vol. 19, 190", pp. 1-28. 

827. ---Principles of classification and correlation of the pre-Cambrian rocks: Jour. Geology, vol. 17, 1909, pp. 

97-104. 

828. VanHise, C. R., and Leith, C. K., Pre-Cambrian geology of North America: Bull. U.S. Geol. Survey No. 360, 

1909; (a) pp. 889-890, 888 (Summary by A. H. Brooks, Alaska). 

829. Vanuxem, Lardner, Geology of New York, part 3, comprising the survey of the third geological district, 

Albany, 1842. 

830. Vaughan, T. W., A brief contribution to the geology and paleontology of northwestern Louisiana: Bull. D. S. 

Geol. Survey No. 142, 1896, p. 52. 

831. ---The Eocene and lower Oligocene coral faunas of the United States: Mon. L. S. Geol. Survey, vol. 39, 

1900. 

832. ---Reconnaissance in the Rio Grande coal fields of Texas: Bull. 1:". S. Geol. Survey No. 164, 1900; (a) pp. 

18-21, 28; (b) p. 37; (c) pp. 37, 38; (d) p. 45; (e) pp. 51-52. 

833. ---Uvalde folio (No. 64), Geol. Atlas U. S., U. S. Geol. Survey, 1900; (a) columnar section. 

834. ---The Miocene horizons at Porters Landing, Georgia: Science, new ser., vol. 31, 1910, pp. 833-834. 

835. ---A contribution to the geologic history of the Floridian Plateau: Pub. Carnegie Inst. Washington No. 133, 

1910; (a) p. 128. 

836. Veatch, A. C., Geography and geology of the Sabine River: Louisiana Geol. Survey, pt. 6, 1902, p. 120. 

837. ---and others, "Cnderground water resources of Long Island, New York: Prof. Paper U. S. Geol. Survey 

No. 44, 1906; (a) pp. 18-26; (b) pp. 27-28. 

838. ---Geology and underground water resources of northern Louisiana and southern Arkansas: Prof. Paper 

U. S. Geol. Survey No. 46, 1906; (a) table opp. p. 16; (b) pp. 20-22; (c) pp. 22-28; (d) p. 36; (e) p. 40; 

(f) pp. 42-43; (g) pp. 43-44; (h) pp. 44-45. 

839. ---Geography and geology of southwestern Wyoming: Prof. Paper U.S. Geol. Survey No. 56, 1907, pp. 50-51; 

(a) table opp. p. 50; (b) p. 56; (c) pp. 56-58; (d) p. 59; (e) pp. 88-89; (f) p. 99. 

840. ---Origin and definition of the term "Laramie:" Jour. Geology, vol. 15, 1907, pp. 526-549. 

841. ---Coal fields of east-c<mtral Carbon County, Wyo.: Bull. U. S. Geol. Survey No. 316, 1907, pp. 244-260; 

(a) pp. 246-250. 

842. Veatch, Otto, Second report on the clay deposits of Georgia: Bull. Geol. Survey GeorgiaN o. 18, 1909, pp. 82-106. 

843. Veatch, Otto, and Stephenson, L. W., Preliminary report on the geology of the Coastal Plain of Georgia 

under directio~ ofT. W. Vaughan: Bull. Geol. Survey Georgia No. 26, 1911. 

844. Walcott, C. D., The Permian and other Paleozoic groups of the Kanab Valley, Arizona: Am. Jour. Sci., 3d 

ser., vol. 20, 1880, pp. 221-225. 

845. ---Utica slate and related formations, and Fossils of the Utica slate: Trans. Albany Inst., vol. 10, 1883, 

pp. 1-38. 

846. ---Pre-Carboniferous strata in Grand Canyon of Colorado, Arizona: Am. Jour. Sci., 3d ser., vol. 26, 1883, 

pp. 439-440. 

847. ---Paleontology of the Eureka district: Mon. "C. S. Geol. Survey, vol. 8, 1884, p. 284. 

848. --- Second contribution to the studies on the Cambrian faunas of North America: Bull. U. S. Geol. Survey 

No. 30, 1886, pp. 32-35. 

849. ---The Taconic system of Emmons: Am. Jour. Sci., 3d ser., vol. 35, 1888, pp. 229-242, 307-327, 394--401; 

map opp. p. 326. 

850. ----Review of Dr. R. W. Ells's report on Geology of a portion of Quebec: Am. Jour. Sci., 3d ser., Yol. 39, 

1890, pp. ll1-113. 

851. --- Fauna of the Lower Cambrian or Olenellus zone: Tenth Ann. Rept. U. S. Geol. Survey, pt. 1, 1890, 

pp. 570-571; (a) footnote, p. 581. 

852. --- Study of a line of displacement in the Grand Canyon of the Colorado in northern Arizona: Bull. Geol. 

Soc. America, vol. 1, 1890, p. 50. 

853. ---Classification of the Quebec group rock (in discussion of the geology of Quebec, by H. M. Ami): Bull. 

Geol. Soc. America, vol. 2, 1891, p. 501. 
BIBLIOGRAPHY. 863 

854. Walcott, C. D., Correlation papers-Cambrian: Bull. U. S. Geol. Survey No. 81, 1891, pp. 310-313; (a) p. 324; 

(b) pp. 330-334; (c) pp. 354-3.56. 

855. --~Preliminary notes on the discovery of a vertebrate fauna in Ordovician strata: Bull. Geol. Soc. America, 

vol. 3, 1892, pp. 153-167; (a) pp. 153-172. 

856. --~Lower Cambrian rocks in eastern California: Am. Jour. Sci., 3d ser., vol. 49, 1895, pp. 142-144. 

857. --~ Lower Cambrian terrane in the Atlantic province: Proc. Washington Acad. Sci., vol. 1, 1899, p. 304; 

(a) pp. 305-311; 318-323; (b) p. 339. 

858. --~New term for the Upper Cambrian series: Jour. Geology, vol. 11, 1903, pp. 318-319. 

859. --~ Cambrian geology and paleontology. No. 1-Nomendature of some Cambrian Cordilleran formations: 

Smithsonian Misc. 8oll., vol. 53, 1908; pp. 2-5; (a) pp. 6-9; (b) pp. 9-12; (c) pp. 11-12. 

860. --- Cambrian geology and paleontology, No. 5-Cambrian sections of the Cordilleran area: Smithsonian 

~lise. Coil., vol. 53, 1908, pp. 185-189. 

861. --Evolution of early Paleozoic fauna~: Jour. Geology, vol. 17, 1909, pp. 196-198. 

862. ---Cambrian geology and paleontology; Abrupt appearance of the Cambrian fauna on the North American 

continent: Smithsonian Misc. Coll., vol. 57, 1910, pp. 13-14. 

863. Wall, G. P., and Sawkins, J. G., Report on the geology of Trinidad: Mem. Geol. Survey Great Britain, London, 1860, pp. 12-13, 17; (a) pp. 33-:{5; (b) pp. 35-52. 

864. Ward, L. F., The Potomac formation: Fifteenth Ann. Rept. U.S. Geol. Survey, 189.5, pp. 307-397. 

865. ---Geology of the Little Colorado Valley: Am. Jour. Sci., 4th ser., vol. 12, 1901, pp. 401-413. 

866. ---Status of the Mesozoic floras of the United States·: Mon. U. S. Geol. Survey, vol. 48, 1905; (a) pp. 13-42. 

867. Washburne, C. W., Coal fields of the northeast side of the Bighorn Basin, Wyoming, and Bridger, Montana: 

Bull. U.S. Geol. Survey No. 341, 1909, p. 167. 

868. Webster, Arthur, Geology of the west coast of Vancouver Island: Summary Rept. Geol. Survey Canada for 

1902, 1903; (a) p. 53. 

869. Weed, W. H., Geology of the Little Belt Mountains: Twentieth Ann. Rept. U. S. Geol. Survey, pt. 3, 1900, 

pp. 284-287. 

870. Weeks, F. B., Bibliography of North American geology, paleontology, petrology, and mineralogy for the years 

1892-1900, inclusive: Bull. U. S. Geol. Survey No. 188, 1902. 

871. --- Index to North American geology, paleontology, petrology, and mineralogy for the years 1892-1900, 

inclusive: Bull. U.S. Geol. Survey No. 189, 1902. 

872. --- Bibliography and index of North American geology, paleontology, petrology, and mineralogy for the 

years 1901-1905, inclusive: Bull. U. S. Geol. Survey No. 301, 1906. 

873. ---Stratigraphy and structure of the Uinta Range: Bull. Geol. Soc. America, vol. 18, 1907 p. 436; (a) pp. 

437-439; (b) pp. 439-440. 

874. Weeks, F. B., and Nickles, J. M., Bibliography of North American geology for 1906 and 1907, with subject 

index: Bull. U. S. Geol. Survey No. 372, 1909. 

875. Weller, Stuart, Correlation of the Devonian faunas in southern Illinois: Jour. Geology, vol. 5, 1897, pp. 625-

635; (a) p. 635. 

876. ----The Silurian fauna interpreted epicontinentally: Jour. Geology, vol. 6, 1898, pp. 698-700. 

877. --~Fossil faunas in the Kinderhook beds: Geol. Survey Iowa, vol. 10, 1900, p. 79. 

878. -- ~ A preliminary report on the Paleozoic formations of the Kittatinny valley in New Jersey: Ann. Rept. 

State Geologist for 1900, Geol. Survey New Jersey, 1901, pp. 3-7. 

879. --- Corniferous fauna in the Appalachian province: Jour. Geology, vol. 10, 1902, p. 424. 

880. ---The Paleozoic faunas of New Jersey: Geol. Survey New .Jersey Rept. on Paleontology, vol. 3, 1903; 

(a) pp. 13-14; (b) pp. 54-80. 

881. ----Northern and southern Kinderhook faunas: .Jour. Geology, vol. 1:~, 1905, pp. 617-634. 

882. --~ Kinderhook faunal studies, IV.-The fauna of the Glen Park limestone: Trans. St. Louis Acad. Sc·i., 

vol. 16, 1906, pp. 435-438. 

883. ---Notes on the geology of southern Calhoun County: Bull. Geol. Survey Illinois No.4, Year Book for 1906, 

p. 225. 

884. ---Cretaceous paleontology of New Jersey based on ~tratigraphic studies of G. N. Knapp: Geol. Survey 

New .Jersey, Paleontology, vol. 4, 1907. 

885. ---The pre-Richmond unconformity in the Mississippi Valley: Jour. Geology, vol. 15, 1907, p. 519. 

886. ---Correlation of the Middle and Upper Devonian and the Mississippian faunas of North America: Jour. 

Geology, vol. 17, 1909, pp. 270-285. 

887. Weston, T. C., Notes on the Quebec group; Ottawa Naturalist, vol. 8, 1894, pp. 81-82. 

888. White, C. A., Geology of a portion of northwestern Colorado: Tenth Ann, Rept. "l'. S. Geol. and Geog. Survey 

Terr., 1878, pp. 34-39. 

889. ----Mesozoic and Cenozoic paleontology of California: Bull. l;. S. Geol. Survey No. 15, 1885. 

890. ---Invertebrate fossils from the Pacific coast: Bull. U.S. Geol. Survey No. 51, 1889, pp. 51, 63. 

891. ---Correlation papers-Cretaceous: Bull. U.S. Geol. Survey No. 82, 1891, pp. 93, 104-106; (a) pp. 104-105. 

892. ---On the Bear River formation: Am. Jour. Sci., 3d ser., vol. 43, 1892, pp. 91-97. 
864 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 

893. White, David, Cretaceous plants from Marthas Vineyard: Abstract, with discu~sion, Bull. Geol. Soc. America, 

vol. 1, 1890, pp. 554-555. 

894. ---Cretaceous plants from Marthas Vineyard: Am. Jour. Sci., 3d ser., vol. 39, 1890, pp. 93-101. 

895. --- The stratigraphic succession of the fossil floras of the Pottsville formation in the southern anthracite 

coal field, Pennsylvania: Twentieth Ann. Rept. U.S. Geol. Survey, pt. 2, 1900, p. 749; (a) p. 759; (b) pp. 

79(}-794; (c) pp. 794-795; (d) pp. 795-800; (e) pp. 800-802; (f) pp. 813 et seq.; (g) Pis. CLXXXI-CLXXXIl. 

896. ---Relative ages of the Kanawha and Allegheny series as indicated by fossil plants: Bull. Geol. Soc. America, 

vol. 11, 1900, p. 145. 

897. ---Permian elements in the Dunkard flora: Abstract, Bull. Geol. Soc. America, vol. 14, 1903, pp. 538-542. 

898. ---Deposition of the Appalachian Pottsville: Geol. Soc. America, vol. 15, 1904, p. 267; (a) p. 267, Pl. XI; 

(b) pp. 267-282; (c) p. 271, Pl. XI; (d) p. 273. 

899. ---Geological position of principal insect-bearing localitie·s of the American Paleozoic: Proc. U. S. Nat. 

Mus., vol. 29, 1906, p. 668. 

900. ---Report on field work done in 1907; Bull. Geol. Survey Illinois No.8, 1907, pp. 268-272. 

901. ---Permian floras in western "Red Beds;" Abstract, Science, vol. 32, 1910, p. 223. 

902. White, David, and Schuchart, Charles, Cretaceous series of the west coast of Greenland: Bull. Geol. Soc. 

America, vol. 9, 1898, pp. 365-367; (a) p. 367. 

903. White, I. C., Geology of Lawrence County: Rept. Progress QQ, Second Geol. Survey Pennsylvania, 1879, 

pp. 46-47. 

904. ---Geology of Mercer County: Rept. Progress for 1878 (QQQ), Second Geol. Survey Pennsylvania, 1880, 

p. 33. 

905. ---Stratigraphy of the bituminous coal field of Pennsylvania, Ohio and West Virginia: Bull. U. S. Geol. 

Survey No. 65, 1891, p. 43; (a) p. 44; (b) p. 70; (c) p. 72; (d) p. 91; (e) p. 99; (f) p. 179. 

906. ---Appalachian coal field: West Virginia Geol. Survey, vol. 2, 1903, p. 339; (a) p. 501. 

907. ---Supplementary coal report: West Virginia Geol. Survey, Rept. II-A and accompanying map, 1908; 

(a) p. 13; (b) p. 23; (c) p. 126; (d) p. 225; (e) pp. 226-240; (f) p. 271; (g) p. 281; (h) pp. 493, 549; (i) p. 

622; (j) p. 623. 

908. White, T. G., Faunas of the Upper Ordovician strata at Trenton Falls, New York: Trans. New York Acad. Sci., 

vol. 15, 1895, pp. 71-96. 

909. ---The original Trenton rocks: Am. Jour. Sci., 4th ser., vol. 2, 1896, pp. 430-432. (Author's abstract of 

paper in Trans. New York Acad. Sci., vol. 15, 1896, pp. 71-96.) 

910. ---Relations of the Ordovician and Eo-Silurian rocks in portions of Herkimer, Oneida, and Lewis counties: 

Fifty-first Ann. Rept. New York State Mus., for 1897, 1899, pp. r 22-r 54. 

911. Whiteaves, J. F., Notes on some Jurassic fossils, collected by G. M. Dawson: Rept. Progress for 1876-77, Geol. 

Survey Canada, 1878, pp. 150-159. 

912. ---Silurian and Devonian fossils (in Appendix to report on Churchill and Nelson rivers, by Robert Bell): 

Rept. Progress for 1878-79, Geol. Survey Canada, 1880. 

913. ---Notes on some Mesozoic fossils from various localities on the coasts of British Columbia: Ann. Rept. 

Geol. Survey Canada, new ser., vol. 2, 1887, p. 108 B. 

914. ---On some fossils from the Triassic rocks of British Columbia: Contributions to Canadian paleontology, 

Geol. Survey Canada, vol. 1, pt. 2, no. 3, 1889, pp. 127-149. 

915. ---Fossils of the Hamilton formation of Ontario: Contributions to Canadian paleontology, Geol. Survey 

Canada, vol. 1, pt. 2, 1889, pp. 91-125. 

916. ---Fossils of the Devonian rocks of the Mackenzie Basin: Contributions to Canadian paleontology, Geol. 

Survey Canada, vol. 1, pt. 3, 1891, pp. 250-251. 

917. ---Fossils of the Devonian rocks of the islands, shores, or immediate vicinity of lakes Manitoba and Winnipegosis: Contributions to Canadian paleontology, Geol. Survey Canada, vol. 1, pt. 4, 1892, pp. 255-359. 

918. ---The Cretaceous system of Canada: Proc. and Trans. Royal Soc. Canada, vol. 11, pt. 4, 1893, p. 16. 

919. ---Revision of the fauna of the Guelph formation of Ontario: Geol. Survey Canada, Paleozoic fossils, vol. 3, 

pt. 2, 1895, pp. 45-109. 

920. ---Fossils of the Galena-Trenton and Black River formations of Lake Winnipeg and vicinity: Geol. Survey 

Canada, Paleozoic fossils, vol. 3, pt. 3, 1897. 

921. ---Additional fossils from the Hamilton of Ontario: Contributions to Canadian paleontology, Geol. Survey 

Canada, vol. 1, pt. 5, 1898, pp. 361-427. 

922. ---The Devonian system in Canada: Proc. Am. Assoc. Adv. Sci., vol. 48, 1899, pp. 193-209. 

923. ---Mesozoic fossils: Geol. Survey Canada, vol. 1, pts. 1, 3, 4, 1876-1903. 

924. ---Report on fossils; Appendix I to Report on Ekwan River by D. B. Dowling: Ann. Rept. Geol. Survey 

Canada, new ser., vol. 14, 1905, pp. 38-59 F. 

925. Whitfield, R. P., Brachiopoda and Lamellibranchiata of the Raritan clays and greensand marls of New Jersey: 

Mon. U. S. Geol. Survey, vol. 9, 1885. 

926. ---Mollusca and Crustacea of the J',fiocene f'omations of New Jersey: Mon. U.S. Geol. Survey, vol. 24, 1894. 

927. ---Descriptions of new Silurian species from near Fort Cassin: Bull. Am. Mus. Nat. IIist., vol. 9, 1897, 

pp. 177-184. 
BIBLIOGRAPHY. 865 

928. Whitfield, R. P., and Hovey, E. 0., Invertebrate Jurassic fossils of the Black Hills: Bull. Am. Mus. Nat. 

Hist., vol. 22, 1906, pp. 389-402. 

929. Wilder, F. A., Geology of Webster County, Iowa: Geol. Survey Iowa, vol. 12, 1902, pp. 99-127. 

930. Williams, H. S., On the fossil faunas of the Upper Devonian: Bull. U.S. Geol. Survey No.3, 1884; (a) pp. 28-29. 

931. ---The Cuboides zone and its fauna: Bull. Geol. Soc. America, vol. 1, 1890, pp. 481-500. 

932. ---Correlation papers-Devonian and Carboniferous: Bull. U.S. Gcol. Survey No. 80, 1891, pp. 265-266. 

933. ---Silurian-Devonian boundary inN orth America: Bull. Geol. Soc. America, vol. 11, 1900, pp. 333-346. 

934. ---Correlation of geological faunas: Bull. U.S. Geol. Survey No. 210, 1903, pp. 42-45, 48-49. 

935. ---Devonian section of Ithaca, New York: Jour. Geology, vol. 14, 1906, pp. 579-598; (a) vol. 15, 1907, 

pp. 93-112. 

936. ---Age of the Gaspe sandstone: Bull. Geol. Soc. America, vol. 20, 1910, pp. 688-698. 

937. Williams, H. S., and Gregory, H. E., Contributions to the geology of ~faine: Bull. U. S. Geol. Survey 

No. 165, 1900; (a) pp. 21-22. 

938. Williams, H. S., and Kindle, E. M., Contributions to Devonian paleontology: Bull. U. S. Geol. Survey 

No. 244, 1905; (a) pp. 32-33. 

939. Willis, Bailey, Some coal fiefds of Puget Sound: Eighteenth Ann. Rept. U. S. Geol. Survey, pt. 3, 1898, pp. 

400-404. 

940. ---Stratigraphy and structure of the Lewis and Livingston ranges, Montana; Bull. Geol. Soc. America, vol. 

13, 1902, pp. 305-352; (a) p. 315; (b) pp. 316, 324-325. 

941. Williston, S. W., New reptiles from the Upper Trias of Wyoming: Jour. Geology, vol. 12, 1904, p. 688; (a) 

pp. 688-697. . 

942. ---The Hallopus, Baptanodon, and Atlantosaurus beds of Marsh: Jour. Geology, vol. 13, 1905, p. 338; (a) 

pp. 339-340. 

943. Winchell, Alexander, Notes on the geology of middle and southern Alabama: Proc. Am. Assoc. Adv. Sci., 

vol. 10, pt. 2, 1857, pp. 82-93 with section; (a) p. 91. 

944. Winchell, N. H., and Ulrich, E. 0., The lower Silurian deposits of the upper Mississippian province: Final 

Rept. Geol. and Nat. Hist. Survey Minnesota, vol. 3, pt. 2 (Paleontology), 1897, pp. lxxxiii·c"Kxix; (a) pp. 

cii-ciii. 

945. Wolff, J. E., Lower Cambrian age of the Stockbridge limestone: Bull. Geol. Soc. America, vol. 2, 1891, pp. 

331-338. 

946. Woodruff, E. G., The Red Lodge coal field, Montana: Bull. U. S. Geol. Survey .'\o. 341, 1909, pp. 90-95. 

947. ---Coal fields of the southwestern side of the Bighorn Basin, Wyoming: Bull. U.S. Geol. Survey No. 341, 

1909, p. 202; (a) pp. 202-203. 

948. --The Lander oil field [Wyoming]: Bull. U. S. Geol. Survey No. 452, 1911, pp. 3-36. 

949. Woodworth, J. B., The Atlantic coast Triassic coal field: Twenty-second Ann. Rept. U. S. Geol. Survey, 

pt. 3, 1902, pp. 43-46. 

950. Woolsey, L. H., The Bull Mountain coal field, ~fontana: Bull. U. S. Geol. Survey No. 341, 1909, p. 65. 

951. Worthen, A. H., Coal measures: Geol. Survey Illinois, Yol. 6, 1875, pp. 1-3. 

952. ---Coal measures and Lower Carboniferous limestones: Geol. Survey Illinois, vol. 3, 1909, p. 9. 

953. Wright, F. E. and C. W., The Ketchikan and Wrangell mining districts, Alaska: Bull. U.S. Geol. Survey 

No. 347, 1908, p. 34; (a) pp. 59-61. 

48011°-12--55 

INDEX. 

A. 

Abo sandstone 

Page. 

363 

Abrams formation_______________________________________________ 242 Abrigo limestone _________________________________________________ 74-75 

Acadian series_ .... ___ ._ ....... _ _ _. _ .... 75,104,145,147 

Acknowledgments to those aiding. ________________________ 5, 21}-21, 31}-61 

Adams, F. D., acknowledgments to ___________________________ 30-31,60 

on pre-Cambrian classification ... _ .......... _ .. _ .............. 65,69 

publications by, list of_______ _ _ _ _ _ _ __ __ _ _ _ __ _ __ _ __ _ __ __ __ __ 840 

Adams, F _ D., and others, publication by __ __ __ __ __ _ __ __ __ __ __ __ 840 

Adams, G. I.,acknowledt,'Tilentsto ........... _. __ . _ ...... 31,56, 57,58,59 

cited___________ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 411}-412, 458, 486 

Adams, G. L, and Purdue, A. H., publication by________________ 857 

Adams, G. L, and Ulrich, E. 0., cited____________________________ 458 

publication by_______________________________________________ 840 

Adams, G. L, and others, publication by__________________________ R40 

Ad{m de Yarza, Ramon, acknowledgments to _____________________ 31,56 

Adaville formation.______________________________________________ 676 

Adirondack Mountains, authorities on._______________ 120, 123-126 geology oL __ __ __ __ _ __ __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ __ _ _ _ _ _ _ __ __ _ __ lli, 121}-127 

Adkins coal __ __ __ __ __ __ __ __ __ __ __ __ __ _ _ _ __ __ __ __ __ _ 455 

Admire shale _____ --------________________ _ __________ 45R,465 

Aguilera,J. G., acknowledgments to___________________________ 31,56 

cited ___________________________ 227,504,589,593,644, 64R, 649, 797-799 

publications by, list of.___ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ 840 

Aguilera,J. G., and Castillo, A. del, cited_____ __ __ __ __ __ __ __ __ __ 551 

publication by______________________________ R43 

Akpatok Island, geology of. ____________________________ 221-223,264,265 

Alabama(H-I 16),authoritieson. _ _ _ _ _ _ _ _ _ __ __ _ __ _ __ _ _ _ _ _ 56, 

84, R7-8.R, 164,363,401-402,406,407,430,605,655 

geology of __________________ . _________________________ 11, 13, 15, 64, 

72,84-88,156, 164-165, 225, 231}-232, 269,274,275,288,355, 363, 

401-407, 418, 425, 430, 452-455, 579, 605-006, 612-614, 748 

publications on ..• --- ______________________ 31, 33, 34, 42, 47, 51, 52,54 

See also Gulf coast; Appalachian Mountains. Alachua clay ________________ . _____ . ___ . _____ . _. ___________ . __ . __ 811 

Alamitos formation ............................................ 55!-552 

Alaska (N-R 3-9), authorities on .. _._. __________ ._. ______ 61,221,353-354 

geology oL ____ 11, 12, 13, 15, 16, 17, 64,156, 221-224, 263-266,336-341, 

355' 392-399, 541-545' 574-577,631-636,698-704,782-793,835-838 

See also Alaska, northwestern; Alaska, southern; Alaska, 

southeastern; Alaska Peninsula; Arctic Coast; Seward 

Peninsula; Yukon region; etc. 

Alaska, northern. See Arctic coast of Alaska; Endicott Range; 

Alaska, northwestern. 

Alaska, northwestern, geology of. __ ... ______ ._._ ........ ________ 355, 

396-399,500,515-546, 5·19, 577,579,635 

See also Cape Lisburne; Cape Thompson; "Uaska, northern; 

Kobuk Valley. 

Alaska, southeastern, authorities on...... . . . . . . . . . . . . . . . . . . . . . . 61, 

262-3:36,393,394,542,632,633, 708, 784 

geology oL ...... _ .. _. _. _. __ .. _. _. ____ .... __ .. ________ 225,252-263, 

21\9,336,355,392-:394,500,542,579,632-633, 639,698,784 

publica !ions on ___ ._._._. ______ ._._ 34,44,52,56,225,262-263,269,336 

Alaska, southern, geology of. ____ .. _. ____ .. _ ....... ________ 225,263,269, 

337-338,355,394-395,500,541-542,708,787-789 

See also Cook Inlet; Controller Bay; Copper River basin 

(lower); Kenai Peninsula; Wrangell Mountains; 

Prince \Villiam Sound; Mount St. Elias Range; 

Nabesna-While River basin. 

Alaska Peninsula, authorities on. 61,574-575,631,632,698,708,782-787,835 

geology of._ .. -- .... . 549, 574-575,579,631-632,639,698,708, 782,796,835 

publications on ________ . __ . ___ . _____ ...... ___________ . __ ._ 31, 47,52 

See also Alaska, southern. · 

Page. Alaska Range, authorities on ___ .. ___________________________ 61,337,790 

geology oL -- ________ . _ .. -.... _______ .. ________ 269, 337, 708, 791}-791 

publications on .. ____ .____ .. __ .. ____ .. ________ .... ____ ...... 34,49 

Albany formation __________ . ___ .. __ ... ___ .. ___ 429,430,478-477,479-480 

Alberta (M-0 11-12), authorities on._._._ 60,336,388,574,624,693-700,781 

geology of.. _______ . ___ .. __ .. _________ .. ___ 10, 11, 14, 62, 64,269,336, 

355,388-389, 549, 574,579, 624-625, 639, 693-700,706, 781-782 

publications on .... __ . ___ .. _____ . __ ... __ 33, 35,37-38,44,46, 47, 51,53 

See also Rocky Mountains of Canada. Albert shale .... ______________ .. _ .. _. _. ____ . ______ . _____ .. __ . _ .. 383, 384 

Alden, W. C.,acknowledgments to. _______ .... _______ ._ ....... 31,57, 59 

cited ________ .................... _ .... _ ..... __________ .. _ .. _ 291}-291 

publication by ______ .. _____ .... _. _______ . __ .. __ .. _. __ ..... ___ 840 

Aleutian Islands, geology of. ___ .......... ____ ._ ......... _. __ .____ 16 

Alexandrian series _ . _ . _ ... _ ... ___ . _ .. _ . _ . _ .... __ . _ .... _ . __ ... _ . _ . 171 

Algonkian system, establishment and subdivisions of. ________ ._. 6.5-66 

See also l(eweena,van; Huronian. 

Allegheny formation _. _ . _ .. ___ . ' ...... _ 431,434-436,443-444,458, 467-468 

Allen limestone _______ . _ .. __ . ______ . ___ ... __ .... _ .. ___ . _ . _ .... _ . _ 458 

Almy formation _. _____ . _ .. __ .. _. ____ ... _ .. _ .. __ . _ ..... _. __ 676-677,765 

Alsek River region. See Yakutat Bay-Alsek River region. 

Altamaha formation __ . _. _. _ .. _ ... _. _. __ . _. _____ .. _ .. _. __ .. _ .. ___ 9, 794 

Altamont limestone ... _. _. ___ . ___ . _. ___ .. __ .. _____ ..... _. _ 457,458,463 

Alum Bluff formation_. __ . __ ._ ..... _ .. _. _____ ._ .. _ 741,742-744,809-810 

Americus limestone_. __ ._ .. _ ... ____ . _ .. _ ...... _. ____ ... _ 458,465 

Ames limestone- ___ ... _____ . ___ .. _._._. __ , .. ______ .. _ ... __ 431-432,436 

Amherst burg formation ____________ . __________ .. _. ______ . _. __ __ _ 248 

Ami, H. M., acknowledgments to __ .. ____ .. __ __ __ . __ .. 31,60, 130,134 

cited_._ 136,183, 195, 196-203,206,207,251-253,326,329-332,385-386,576 

publications by ______ ._. . __ . _. _ .. _ ... ___ . 183,204, 841}-841 

Amsden formation . ____ .. _. _____ .. ___ .. ___ ...... __ .. _ ........ _ 373,495 

Anacacho formation .... __ ...... _ . ________________ ... __ .. ___ . _ . .. 649 

Anaktnvuk River basin. See Endicott Range, etc. Anaktuvuk series _ . ____ .. __ . _ . ____ . _____ ... _ . ___________ . _ . __ .. _ 636 

Anamosa limestone __________ . ___ . 242 

Anderson, F. M., acknowledgments to .. ____ . __ ._. _____ ._. __ .. 31,56 

cited ___ -----._._.----.--.-. ___ ._ .... ________ . __ .. _._._. ____ 667-668 

publications by ...... ~- ................. _ ....... _ ...... 615,820,841 

Anderson, Robert, acknowledgments to .. ___ . _____ .... _. __ ._._ 21, 31,56 

Anderson, R., and Arnold, R., cited _______ 616,617,668-669,814,816-818 

publications by, Jist oL __ . __ . ____ . _. _. ____ . _. _ .. _. ______ . _ _ 841 

Anderson coaL- _________ .. _ .. _ . __ ... _____ . _ .. __________ . _ . 436, 444, 451 

Anderton limestone . __________ . ______ . _______ . ___________ . __ __ 248-2{9 

Andrews schist ____________ .. __ . ___ . ___ .. ___ . __ . _ ... _______ . __ __ _ 98 

Animas formation . _________________ . ___ .. _. __ ...... _ .. ____ 660,755-756 

Animikie group .. _ ... _. _ ... _____ . __ .... __ . _. ____ . __ . _. ___ . __ . _. _ 14 

Ankareh shale ___________ ._.-- __________ -- ___ . _________ . __ .. __ . 380,494 

Annona chalk .. _____ . ____ . -- .. _________ . _____ . _ . ______ . _______ 652-653 

Anthracite region, geology of.- __ .. ____ . ____ .... _ . _ .... __ . _ . __ __ 439-442 

Anticosti group ____ . ___________ . _______ . ______ .... ______ . _ . __ __ __ 209 

Anticosti Island (M 20), geology of. ______ . __ . ____ ._ .. _. 209,225,259-261 

Antietam sandstone ____________ .. _. _ ... ______ . __ . ___ . _. ____ . _. _. 109 

Antrim shale. _______ .. _________ .. ________ • ____ . ___ 313,314-315, 421}-421 

Am·il Rock sandstone ___ . _ ... ________ .. _____ .. ________ . __ . _ . __ __ 468 

Apalachicola group _____ . __ ....... _________________ 731,740-745,808-810 

Apishapa formation_. __ . _____ . __ . __________________ . _. __ . _. __ 662-663 

Apison shale ... ____ . __ . _________ .. _ . __ . ________ . __ ... _ . _________ 89-92 

Appalachian coal field, geology of. ___ . __ ._._. ______________ 425, 431}-455 

Appalachian Mountains, authorities on __ .. ______ ._. _____ .. __ ._._ 21,164 

See also Alabama; Georgia; Tennessee; Virginia; 'Vest Vir· 

ginia; Maryland. 

geology of. ___ ._. _____ 12, 13, 15, 16, 71}-71, 156,164-165,237,269, 431}-455 

Appalachian Valley, geology oL ________ ... 109-111,269,274-275, 431}-455 

See also particular States. 

867 
868 INDEX. 

Page. 

Appanoose formation .................................. 457-458, 46&-466 

Appleton group................................................. 458 

Aquia formation ........................................... 746,748,749 

Arago formation ........................................... 751,771-772 

Arapahoe formation ................... _ .. _ .. ___ .. 10,706,761-762 

Arbuckle limestone ............................................. 82, 159 

Arbuckle Mountains, Okla., geology of....... . ....... 159-160,228-230 

Arcadia mar I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 811 

Archean system, establishment of.. . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 

subdivision of................................................ 67 

See also Keewatin; Laurentian; Pre-Cambrian. 

Archean of Dana, subdivision of................................. 67 

Archimedes group.......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408, 412, 458 

Arctic Archipelego (R-T 10-17), authorities on ... 60,222,223,226,341,547 

geology of. .......... 62,156,222-224,226-227,269,341,500,547,838-839 

publications on .......................................... 33,45-46 

Arctic coast of Alaska, geology of................................ 9, 

10, 12,355,579,636,639,704,792-793,794, 796,838 

See also Alaska, northern. 

Arctic coast of Canada, geology of ............. 12, 13, 15,225,264-265,355 

See also Queen Charlotte Islands; Ellesmere Land; Mackenzie Valley; Bear Valley; Hudson Bay; Ungava Bay; 

Baring Land; Parry Islands; Grinnell Land; Arctic 

Archipelago, etc. 

Arctic Miocene, classification of. ................................ 97,794 

Arctic region. See Arctic coast; Arctic Archipelago; Hudsoii Bay; 

Greenland; Alaska, etc. 

Arikaree formation ........................................ 821-822,830 

Arisaig formation ...................... __ ....... __ .... ____ ..... 252,332 

Arizona (H-J 11-12), authorities on .................. 21,56, 72,81,88,89, 

159,228,271,272,284,357,361,366,367,484,485,513-517,592 

geology of ............................................... 11, 15, 64, 

72,74-75,81,88-89,156, 158-159,228, 269,271-273,284,357-

358, 361-362,366-367, 474, 484-486, 500,513-517, 579, 592-593 

publications on.............................................. 32, 

34, 35, 36, 38, 40, 42, 43, 44, 45, 48, 49, 50, 54, 55 

Arkadelphia shale.............................................. 653 

Arkansas !I-J 1S), authorities on................................. 56, 

103-105,160,169,408,411,412,653,723,804 

geology of. ................................................. 72, 103-

105,156,160-164,169,269,274,400,407-412, 4S", 

456, 458, 637,653-654,706,723-731,794,804-805 

publications on ....................... 31, 34, 35, 36, 40, 41, 49, 52, 53,54 

See also Interior region; Mississippi embayment. 

Arkansas novaculite ....................................... 160,163-164 

Arkansas Valley, geology of. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 458 

Arnheim formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172 

Arnold, Ralph, acknowledgments to ....................... 21,31,56,59 

cited.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 572, 685, 750-7.56, 814-815, 832-833 

publications by, list of. ................ :.................... 841 

Arnold, R., and Anderson, R., cited .... 616-617,668-669,754,814,816-819 

puhlications hy, list of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 841 

Aroostook limestone............................................. 328 

Aruha, geology of. ............................................. 637,639 

Arundel formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 610-613 

Ashhurner, C. A., cited.......................................... 419 

Ashland formation... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328 

Ashley, G. H., acknowledgments to......... . ...... 20, 21, 56,-17, 58,59 

cited.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 436, 45&-460, 466-469 

pub Vi cations by ............................................ 413, 841 

Ashley, G. II., and Blatchley, W. S., cited·_..................... 412 

puhlication by..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 842 

Ashley, G. II., and Fuller, M. r.., cited ........................ 467-468 

publication hy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 849 

Ashley, G. H., and Glenn, L. C., cited........................... 450 

publications by............................................. 841 

Ashley-Cooper mart................................... 739 

Aspen formation................................................ 676 

Atane series ................................................... 705,838 

Atascadero formation ......................................... 616, 668 

Atchison shale.................................................. 458 

Athahaska-Nastapoka series..................................... 14 

Athens shale ............................................. 92-94,96,174 

Atlantic coast, authorities on ............................... 21,608,806 

geology of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-10, 

11,401,579,608-614,637,670,706,731-749,794,806-813 

See also particular State-'. 

Atlin Lake district, geology of. ................................ 549,576 

.A,tokaformation ...... -. •...........•.......................... 458,459 

Page. 

Attleboro sandstone.......................................... 145,469 

Atwood, W. W., acknowledgments to ........................... 11,31 

cited ....................................... 632,698,783-784,835-836 

puhlication by.............................................. 841 

Auhrey group ......................... 357,361-362,366-367,378-379,558 

Augusta formation................................. . .... 408,420 

Austin chalk ............................................... 649, 651}-651 

Aux Vases-sandstone.................................... 413 

Avalon group ........................................... 14, 16,142,145 

Avalon Peninsula, geology of............. . . . . . . . .. . . . . 13 

Avant lin;estone............................... 464 

B. 

Baffin Land, geology of................ .. ............ 221-224 

Bailey, L. W., acknowledgments to....... .. ...... 31-32,60 

cited ....................... 135, 136, 207, !.50, 256,332,383,473,497-498 

publications by ........................................... 254,841 

Bailey, L. W., and Ells, R. W., cited............................ 384 

publication by.................................... . . . . 848 

Bailey, L. W., and Mclnness, W., publications by. ..... 254,841 

Bailey, L. W., and others, cited ............................ 325,326,384 

publications by, list of........................................ 841 

Bain, H. F., acknowledgments to ................................ 32,57 

cited ........................................... 176,243-244,456-458 

publications by, list of...................... . . . . . . . . . . . . . . . . 841 

Bain, H. F., and Ulrich, E. 0., publication by................... 841 

Baird formation................................ 373-375 

Bakerstown coat.......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 436 

Baldwin, D., cited................... 755 

Ball, M. W., acknowledgments to...................... 3],56,58 

cited................................................. 766-767 

publication by......................................... 841 

Ball, S. H., acknowledgments to ................................. 32,58 

cited ................................................... 679,819-820 

publications by ............................................ 702, 841 

Bancroft, Howland, acknowledgments to..... . ............. 32,56 

Bancroft, J. A., acknowledgments to. . . . . . . . . . . . . . . . . . . . . . . . . 32, 60 

Bandera shale................................. . ........... 458,463 

Banff limestone............................................. 388-389 

Bangor limestone .......................................... 403-406,418 

Banks Land, geology of.................. . ........... 355,399 

Baraboo quartzite . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 

Barbican formation ...•.••••••................................. 799,801 

Barbour, E. H., acknowledgments to ............................. 32,58 

Barclay limestone............................................... 458 

Bard, D. C., acknowledgments to ................................ 32,58 

Baring Land, geology of.. ...................................... 355,399 

Barlow, A. E., acknowledgments to .............................. 32,60 

cited......................................................... 250 

publication by............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 842 

Barlow, Scott, acknowledgments to ............................. 32,252 

Barnett, V. H., acknowledgments to ............................. 58,59 

Barnett, V. H., and Kindle, E. M., cited........................ 233 

publication by................................................ 853 

Barnwell sand ..............•.................................. 736-737 

Barrell, Joseph, cited........................................... 417 

publication by........ . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . 842 

Barroteran formation .......................................... 648, 649 

Basal sandstone............................... . .............. 145-147 

Bascom, Florence, acknowledgments to... . ............. 32,58,59 

cited ............................................... 111-113,177-178 

publication by....................................... 842 

Bascom, F., and others, publications by, list of...... 842 

Bashi formation....................................... 733 

Bass Islands series ......................................... 246,247,248 

Bassler, R. S., cited ........................................ 175,740,749 

publication by............................................... 842 

Bassler, R. S., and Ulrich, E. 0., cited........................... 164 

Bastin, E. S., acknowledgments to ...................... 21,32,57,58,59 

cited......................................................... 350 

publication by..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 842 

Batesville series ........................................... 411-412,458 

Battie quartzite................................................. 135 

Bauerman, Hilary, acknowledgments to .......................... 32,60 

Baxton schist................................................... 472 

Bayard formation............................................... 443 

Bayley,W. S., acknowledgments to .............................. 32,58 

Bayport formation ............................................ 420,423 

Bays formation ................................................ 230-231 
INDEX. 869 

Page. 

Beacon Hill formation ..................................... 745, 746, 749 

Bearpaw shale.............................. . . . . . 687-690 

Bear River, authorities on ..... _ ......... _..... 264,837 

geology on...... 225,264,796,837-838 

Bear River group. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 676 

Bearwallow formation ... ______ ..... __ .. _ ...... _.... 449-450 

Beaverfoot Range, geology of.. __ ..... 207-208 

Beaver formation ............ _ ............ _........... 84,89,92 

Beaver River group. _____ . ___ ....... _ ..... _. 434,444 

Becker, G. F., acknowledgments to... :3:3,.56,59,61 

Becl.--with formation .... _ ... _. __ .... _ ..... __ ...... 56.5-566,676 

Becraft limestone.................................... . . 295,297,300 

Bedford oolitic limestone............................... . ... 412,413 

Bedford shale _...... 315,408,409,414,415-417.420-421 

Beede, J. W., acknowledgments to.. 33,57 

cited...... . ..... 359,476,479,487.496 

publicationsJ:>y, list of..................... 842 

Beekly, A. L.,acknowledgmentsto ........................ 33,55.57,59 

Beekmantown group ..... 13,72, 109,111,130,134,184,186,191, 197, 21!-212 

Bell, .T. l\L, acknowledgments to............... . .... 33,60 

cited. . . . . . . . . . . . . . . . . . . . .. .. . . . . . .. . . . . . .. . . . . . . 264. 704 

publication by............... 842 

Bell, Robert, acknowled~ments to................. . ... 33, 60. til 

cited ................... 195-196,220,221-222,223, 245-246,264, 2G9, 335 

publications by, list of.................... 842 

Bell, Robert, and others, publication by........................ 840 

Belle Isle formation.......................... 124,145 

Bellevue formation.......................... 172 

Bellowspipe limestone ................................ . 

Bell shale ................................ .. 

Bellvale sandstone ......................................... . 

193,194 

314 

296 

Belly River series ......................................... 693,695,696 

Belt series . . .. . . . . . . . . . . . . . . . . . .. . . . . . 14, 16, 62, 64, 67 

Belva shale.................................... . . . .. . . . . . . 458 

Belvidere formation ............................ . 606 

Bend formation................................... . . . . . . . . . . . 374 

Benton shale .............. 64~, 666,672,674,676,681,693,694-695,697,698 

Benwood limestone........................................... 438 

Berea grit................................ 315,408,414, 41E-417, 420-421 

Berkeleyan formation........................................... 816 

Berkey, c. P., cited... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176 

publications by......... . .. . . . . . . . .. . . . . . . . .. . .. . . . . . . . . 169,842 

Berkshire schist.......................... . ........... 192,193, 194 

Berry. E. W., acknowledgments to ............ 33,56,57,58,59,612,731 

cited ................................... ()06, 657,658,659,749,811-812 

publications by......... . ....................... 611.824 

Berry, E.'"·' and Matson, G. C., cited......... . ... 806--813 

Bethany Falls limestone ... _..................... 4.57, 458,464 

Bettles group .. . .. .. .. .. .. .. .. .. . .. .. .. .. .. . . . . .. 340 

Bibbins, A., and Clark, W. B., pulJlicatiom; by, list of..... 844 

Bibbins, A. B., acknowledgments to....... 34,57,.j8,59 

Bibliography of material used.... . .. 30-56 

of publications cited................... . ............. 840-865 

Bicknell sandstone ......................................... 561,563-564 

Bigby limestone .. .. .. . . . . .. . .. . . .. . .. . .. . . .. . . . . . . . .. .. .. . .. . 168 

Big Clifty sandstone . .. . .. . . . . . .. . .. . .. .. .. . .. . .. .. . . . . . .. .. .. .. . 413 

Bigfork chert................................. . ............ 160-162 

Bighorn dolomite ............................................. 179-180 

Bighorn Basin, geology of 706,774-775 

Bighorn Mountains, geology of..... .. 179,372 

Big Injun sandstone..... .. .. .. .. .. . .. . . .. . .. . .. . .. . . . . . . 415 

Billings, E., cited .............. 133, 153, 195,210,213-216,257.258,260-261 

publications by... .. .. . .. .. .. .. .. . .. 334.842 

Bingen sandstone .. .. .. . .. .. . .. .. .. . .. . .. . .. . . . .. . . . . . . . . . 652 

Birdseye limestone ........................ 170, 18:!,194, 198-200,209-210 

Birdsville formation . .. . . .. . . . .. . . .. . .. . .. . .. . . .. 411.413, 458 

Birmingham district, geology of...... 164-16.5 

Bisbee district, Ariz., geology of. .... 72,74-75 

Bishop conglomerate . .. . . . . . . .. .. . .. . .. . .. . .. .. . . . . . . . . 759 

Black Creek coal . .. . .. . .. . .. .. . .. . .. . . .. .. . .. . .. . 454 

Black Creek formation............... 11. 60ti. 611-614, 637,655,6.58-660 

Blackhand conglomerate ............................... 408.414,422,430 

Black Hills, S.Dak., authorities on... 118 

geology of._................ . ........... 12, 72, 118, 156, 176,372-373 

See also North Dakota. 

Black Mingo formation .. .. .. .. .. .. . . .. . . .. .. . .. . . . . . . . 732 

Black River group................................ 168, 

170, 183-184,186,191,194, 197-202,209-210,212,217-218 

Blacksmith formation ................................ . 

Blackwater formation_ ............................ . 

Page. 

106 

445 

Blackwelder, Eliot, acknowledgments to.......... . 34,59, 61 

cited ................................... 106, 117,176,237,283-284,379 

publication by................................... . .. .. .... .. 842 

Bladen formation. See Black Creek formation. 

maine formation .. -.. - ... -......... -......... -...... 478, 487-488,490 

Blake, W. P., acknowledgments to.................. . ..... 21,34,56 

cited...... . . . . . . . . . . .. . . . .. . . . .. . . . . . . . . .. . .. . 506-507,814 

publicationby..................................... 842 

Blatchley, W. S., and Ashley, G. II., cited..................... 412 

publication_by......... ............. 842 

Blaylock sandstone ........................... , ................ 160-163 

Bliss sandstone ........ _ ................... ___ . _. _. _ ....... ____ .. 75-76 

Blocks, geology of: 

B-17........ ..• •• . . . . . . . . . • . . . . . . . . . .•• .. .. •• . . . . . . . . . . . . . . . . . . 64 

B-18 .......................... 64,342,344,579,581-582. 7GG, 708,794, 796 

B-19 .............................. 64,342,344,579,583-584,706,708-709 

B-20........ ..... . ................................ 64.579.58.3-584 

C-16................. . ............ 706, 709-711 

C-17........... .. .. . . .. . .. . ......... 583,706,711-714 

C-18.......... .. .. 579,581-582,794,796 

C-19. .......... . ..................... 64,579,583-584,706,708-709 

C-20............. 64,342,344-345,579,583-584, 706, 714-716 

D-14.............. .................................. 64 

D-15............ . .......... 64,42.5-427, 500,503-504,579,58S-587 

D-16............. . .. 64,342,345,425-427,500-503,549,579,585-587 

D-19............. . .................................... 637,639 

E-13...... ... .. ... .. ............................. 64,579,589-591 

E-14 .............. 64.500,504-.505,549-551,579, 587-58§. 589-591, 794, 797 

E-15...... 64,500,503-504,579,58.5-587,588-591, 700,721-722,794,797 

E-16............. .. ....... 64,355-357,579,585-587, 706, 721-722 

E-17............ . ................................. 706,717-721 

E-18 ............................. 637,639-642,706,717-721,794,799-801 

E-19............. . ........ 342,345-348,637, 642-643,794,801-803 

F-12........ ... . .. . . . . ......................... 579,589-591,794,799 

F-13 .......................................... 64,579,689-591,637,644 

F-N .......... 64,500,504-505,549,551-552,579,589-591,637,644,194,797 

F-15 ..................................................... 706,721-722 

F-16 ......................................... 706,721-722,794,797-798 

F -17............ 342,348-349,549,552,637,643,706,722-723,794,803-804 

F -18 ............. 342,348-349,549,552,637,643,706,722-723,794,803-804 

G-12..... . ...... 225,227,579,589-591,637,644-647,194,797,799 

G-13 .......................... 64,549,552-5M,579,589-592,637,644,648 

G-14. . ....................................... 549,552-554, 

579, 589-592, 637, 644, 648, 706, 723-731, 794,797,799,804-806 

G-17 ......................................... 706,731-745,794,806-813 

H-11 ......................................... 637,644-648,794,797,799 

H-12. . 72,74-75,225,227,269,271-272,355,357-358,579,589-591,592--504 

H-13 .................. 64, 72, 75-77, 156, 158,225,227,355,358-360,474-

479,549, 554, 579, 589-591, 594-5g8, 637, 649-652,794,813-814 

II-14 ........................................... 64, 72,77-80,425,427-

428, 474-479, 579, 589-591, 598-604, 706, 723-731, 794, 813-814 

H-15 ............................. 579,589-591,706, 723-73l, 794,804-806 

H-16 ......................................... 706,731-745,794,806-813 

H-17 .................... .' .................... 706,731-745,794,806-813 

l-10 .............................. 549, 554-555,637,667-670,794,814-818 

I-ll. ...... 64,500,505-506,549,554-555,706,750-751,794,797,799,814-818 

I-12 ..................... 64,72,81,88-89,156,158-159, 225,228,269,271'-

273,284, 28.5,355, 357-358, 361-362, 474, 479-486, 500,510-518 

I-13 ............................................. 64,72,81-82,156,158-

159,225,228,269,273,284-285,355,358-360,362-363,474-486, 

500, 506-508,510-518, 579,606-608,637, 660-667,794,813-814 

I-14 ......................................... 65,72,82-84,156,159-160, 

225, 228-230, 269, 273-274,425,428-430,455-466, 474-479, 486-

490, 500, 506-508, 579, 601-605, 606, 637, 650-652, 794,813-814 

I-15 ......................... 72,82-84,156, 160-164, 269, 273-274, 425, 

455-466, 579, 604-605, 637, 652-653, 706, 723-745, 794,804-813 

I-16 ........................................... 64,65, 70-71, 72,84-98, 

156, 164-168,225, 230-235,269,274-282,355,363, 401-407, 425, 

430-455,579, 605-606, 637, 653-660, 706, 731-745, 794, 808-813 

I-17 .................................................... 64,65,70-71, 

72,81-89, 156,165-168,225,230-232,237-242,500, 508-510,579, 

605-606, ()08-614, 637, 654-660, 670, 706, 731-749,794, 806-813 

I-18 .................. 64,225, 237-242, 579,608-614,637,670,706,745-749 

J-10 ... -...... -.- .. -.. -.---.-.-.- 355,363-364,500,519--523,527-528,549, 

554-555, 579, 615-617, 637, 667-670, 706, 751-754,794,815-820 
870 INDEX. 

Blocks, geology of-Continued. Page. 

J-11 ············-······························-········ 64,72,88-89, 

98-102,156, 168-169,225, 236-237, 269, 282-284, 355, 364-366, 

500, 521-522,527-528,549,554-556, 706, 750-751, 794,815-820 

J-12 ..... --.- .... -.... -. --.- .. -.. - --.-- ·- ..•.. - -- .• 98-102,156,168-169, 

225,236-237,259,282-288,355,366-367,474, 479-486,500, 510-

518, 527-528, 549, 556-561, 637, 670-671, 706, 755--757, 759-761 

J-13 •.•••...•.....••••..•••...••••..••..•..•....•.•••.• 64,72,102-103, 

156, 169, 355, 367-373,474,470-486, 490-492, 500, 510-512,579, 

606-608, 637, 639, 660-667, 672-{)73, 706, 755-764,794, 813-814 

J-14 •••••.. ----.----- .• -..• --.- .• - -·--- •..•. ---- .•• --.-.-- •• 425,455-

465,474,486-490,579,606,614-615,639,672-674, 794,813-814 

J-15.--- ·--. ·------ .• ·- .•.••• -- •• -•. ------ .. ------ •••. ---- 64, 72,103-

105,156, 169-171, 225, 236, 269,278-282, 407-412, 425, 455-458 

J-16.-- ••••• ----.--- 72,89-98,156, 16:>-172, 225,230-235,269,275-282,401, 

412-413, 425, 430-455,637, 654-660, 706, 731-745, 794, 806-813 

J-17 ..... --- .•• ----- .••. ------- 64, 65,70--71, 72, 89-98,156,165, 168, 173-

175,225,230-232,269,274-275,285-288, 401,414-420, 425,430-

455, 474,492-494,500, 508-510, 518-519, 579, 608~614, 637, 670 

J-18.--- •..• 64, 65, 70-71,156, 173-175, 269, 285-288,401,417-420,425, 430-

455,500, 518-519, 522-527, 579, 608-614, 637,670, 706, 745-749 

K-10 ...•.......•• _ ..... _ ..... 64, 156, 175,225,242,269,288-289,342,349-

350,355,373-376,474, 494, 500, 519-521, 527-528, 549, 554-555, 

561-565, 579, 615--621, 637, 667-570, 706,764, 771-772, 794, 820 

K-11 ..•....••.....••• __ ....•••....••• 64,225,236-237,269,282-288,342, 

350, 355, 376, 500, 527-528, 549, 554-555, 794, 819-821, 824-825 

K-12........ .. . .• • •. • . • . . . • .. . . • . . . . • . . . . . . . • •• .. . . . •• . . . • . . . • 64, 

72, 106-107,116-117, 156, 175-176, 179-180, 225,236-237, 244, 

269,282-285,342, 350, 494-495, 500, 510-518, 527-532,549,565-

567, 639, 673-678, 684-685, 706, 759-761, 765-766, 794, 820-821 

K-13 •.... 64, 72,116-118,156,176,179-180,269,284-285,474,490-492,494-

497,500,510-518, 531-533, 549, 566-570, 579, 606-608, 637, 639, 

670-673, 678-681, 684-685, 706, 759-764, 766-770, 794, 821-823 

K-14 ...... 64, 425,455-466,637,670-673,639,682,706, 769-770,794,821-823 

K-15 ...•.....•.•.........•.•...•.• _ ......• 64, 72,118-120,156,180-183, 

225, 242-244, 269, 290, 401,407-412, 425, 455-468, 497, 639,682 

K-16 •......•••.•..•.••••• 72,118-120,156,176,178-179,225,232-235,242-

244, 269, 290-291, 313-319, 401, 412-413, 420-423, 425, 466-469 

K-17 .•.•.•.••••. 156,183-192,225,237-242,244-245,269,285-288, 291-319, 

401, 414-423, 425, 430-455, 474, 492-494,579, 608-614, 637, 670 

K-18 .•....•••....••••..•.............................. 64, 65, 72, 107-

114, 120-127, 156, 176-179, 183-194, 225, 237-242, 244-245, 269, 

285-288, 293-313, 342, 350, 401, 417-420, 425,430-455,500,522-

527, 532,579, 608-{)14,637, 639,670,682,706,745-749, 794,823 

K-19 •..........•••........••........................•... 64,156,192-

194, 342, 350, 425, 469-472, 639, 682-684, 706, 745-749, 796,823 

K-20... •. . . . . . •••. •• •• •• •• •• .• •• . • ••• .• • . . . . . . . • •• . . . . . . . . • . • . . 04 

L-10.-- .•. -- -- ••• -•••••• -•••• ---•.•. --- ... ----. 500,527-528,549, .572-

573, 579, 621, 639, 685, 706, 771-774, 778-780, 798,825-8:31,832 

L-11 ...•.•...•.•...••.•.•.•.•..••.•.. 64,342,350,380-381,386-387,500, 

.527-528,533-534,549,571,639,685,798,824-825,826-831,833-834 

L-12 ........•...• 62,64, 72,116-117,127-130,156,178-179,194,225,244,269, 

319-324, 342, 350, 381-382, 386-387, 500, 527-528, 534-535, 549, 

571-572, 579, 621-623, 639, 684-691, 706, 774-777, 796, S:Jl-834 

L-13 ..••.•..••••.••••.••••.•......•.......... 62,156,179-180,355,372-

373,500, 533, 549, 566-570, f>39, 684-691, 706, 761-764, 777-778 

L-14.----.- ••••• -.- .•.•. -.•. 62, 64, 72, 116-118, 148,639, 691, 706, 761-764 

L-15 .•••••.•••.•....••••••••••••••.• 62, 64, 72, 118-120, 148, 156, 180-183 

L-16 ..••.•..•••••...••.•••••••.••.•••.•....••.. 62, 64, 72,118-120, 148, 

156, 194-195, 225, 242-244, 246-250, 269, 313-319, 401, 420-42:3 

l.;-17 ............................................. 62,64,65, 72,148,15(), 

183-192, 195--196, 225, 244,246-250, 269, 313-319, 401, 421--123 

L-18 ...•.•...•.....•.•.•.•.....•...•...• 62, 64, 65, 72,120-127, 130-1:H, 

148, 156, 183-194, 196-206, 225, 244, 250, 269, 324-325, 342, 350 

L-19 ...•.•..••.•.. ···---- 62, 64, 65, 72, 130-136, 148, 156, 192-194,196-

207, 225, 250, 252-256, 269, 325--329, 342,350, 355, 383 42.5, 473 

L-20- •••• -- •.• -••. -.•••••• - 62, 64, 72, 136-147, 148,225,250-256, 2(i9, 329-

332, 355, 383-386, 401, 423, 425, 473 ,474, 497-499, 500, 535-536 

L-21. •.•.....•.•.....•.••........... 62, 64, 72, 136-147, 148,225, 25G-258 

L-22 •.••.• --- ... -----. -----.-.-------------------.-- 62,64, 72,136-147 

M-8 ••••....•............•....•.•.....•...... _ ........... 355,390-394 

M-9 .....•.•... 342,350-.351,355,390-.394,500,.536-538,549,574,639,692-694 

M-10 ....•..••.•........... 64, 342, 350-353, 355, 390, 394, 500, 536-539, 

549, 572-574, 579, 623-628, 639, 692-694, 706, 778-781, 796, 832 

M-11. .•.• ____ •• ___ ...•. ___ .... __ .. __ . __ ...• __ .... ___ ..... 64, 154, l5r, 

207-208, 225,258, 269, 333, 342, 352-353, 355, 386-389, 390-.194, 

549, 574, 579, 624-625, 639,695--697, 706, 781-782, 796, 833-834 

M-12 ................................................ 64, 225, 261-262, 

355, 386-387, 579, 624-625, 639, 694-697, 706, 781-782, 796,834 

Blocks, geology of-Continued. Page. 

M-13 .••••..••........... _ ........•...•..•... 261-262,695-{)98, 796,834 

M-14 .................................................. 62, 64, 72,148, 

156, 217-219, 225, 261-262,269, 335, 639, 695-{)9R, 796, 834-835 

M-15 .•••••...•.•.........•................. ·: . ...... 62, 64,65, 72,148 

M-16 ..•••• ., •••.•........•................. 62, f>4, 72,148,269,335-336 

M-17 ...•••...•.••.............•................ 02, 72,148,269,335--336 

M-18 ................................................. 62,64,65, 72,148 

M-19 •••••.....•.. 62,65, 72,148-149, 1JG, 208-209,225,252-256,269,333-334 

M-~0 .••••.••••••................................... 62, 65,72,148-149, 

156,208-210,225,252-256, 259-2H1, 269, 334-335, 401, 423-424 

l\I-21. •••••••••• -••• 62, 64, 72, 148--153, 156, 211-217,225,256-258,389-390 

M-22 •.••••••••.••..•............•...............•..........•... 62,64 

N-4 .•••••.•••••...••.•............... 579,631-632,708,782-784,796,835 

~-8 ................. --.-.----.-.--.-.--- .•.• --- •. -- .•• -- 225,262-263, 

342, 350-351, 355, 390-394, 500, 539-541, 579, 628-630, 796, 834 

~-9.- •• -.- .••.•••••••.. -.--.-.------ •• -- •• ·---- ----- 269, 336,342,35Q3tll, 355, 390-394, 500, 539-541, 549, 574, 579, 625-631, 796,834 

N-10.. ••• ••• ••• •• •• • ••• ••• . • . . • • . . . . •• . •. •• •. . .. . . . . . • . . • • . .. • 64, 

225,263, 342, 353, 355, 390-394, 549, 574, 579, 625-628, 796, 835 

N-11...................... .. ... .. .•. ....•. .. . .•.. .. ..... .. .. .. . 64, 

154,342, 353, 355, 390-394, 500, 541, 639, 695-697, 706, 781-782 

N-12 ••••.•..••••••.•.......•......... 269,336, 639, 695--697,706,781-782 

N-13 .•••.••.••••••••••.•.......... 62,225,261-262,269,336,639,695-698 

N-14. ......••••• 62, 72,148,156,217-219,225,261-262,269,335,639 695-{)98 

N-15 .•.•.•..••.•••.••..•.•...................•.•... 62, 72, 148,225,263 

N-16 ............•...................... 62, 72,148,225,263,269,335--336 

N-17 .•.•........................... 62. 65, 72,148,225,263,269,335-336 

N-18 •••...................•.................•........ 62, 64,65, 72,148 

N-19 .......•.••......................................... 62,64, 72,148 

N-20 .........•..................................•.... 62, 64, 65, 72, 148 

N-21. ..•.....•.•..................................... 62, 64, l\5, 72,148 

0-3 .•.• -- ..•• -------.---------.-------------------------- 342.353-354 

0-4 ... --- .......... -.... -.... -.- .. --.- .. -..... -.. 342, 353-354, 549, 574-

575, 579, 631-632, 633-634, G:l9, 698, 708, 7&3-784, 796, 835-836 

0-5 .• 342,353-3.54,500,541-542,549,574-575,639,698, 708, 783-7R4 .• 785-787 

0-G .•.••..•••........•.....•.•..•.••.•.•.....•..•........ 342,353-354 

0-7.- ••••.••••• --------------.-.-- .•. ---- •• -- .•.• 342,353-354,500,542 

0-~- ..•.••••• -•. -••• ------ 225, 262-263, 209 336 342, 353-354, 355, 390-

394, 500, 542, 549, 576, 579, 632-633, 634-f>35, 639, 698, 708, 784 

0-9 -················-----------·---------------- 64,156,219-220,269, 

336-337, 353, 355, 390 ·394, 500, 542-543, 579, 625-628, 796, 836 

0-10 .••••••. -••• -••.•.• --- •• ·------ .• ------.--- •. -------------- 64, 

225, 263, 269, 336-337, 353, 35E, 390-394, 639, 698-700, 708, 785 

0-11. ••... -..•••• -.------ 209,336-337,355,390-394,500,541,639, 698-7()(') 

0-12 .•.•........................ 62, 64, 72, 148,209, 33Cr337, 639,698-700 

0-13 ... ----- .. ------------------------ ·---- ----- 62, 64, 72,148,269,336 

0-14.---------------------------------------.-------------- 62, 72,148 

0-1!J ................................ G2,6J, 72, !48, lr.5,220-221,225,263 

0-16-------------- ---'---------------------- 62. 72,148,225,263 

0-17 _____ ................ _.... . ............ 62, 65, 72,148, 22S, 263 

0-18 ..•. ---- .. --- -------------------------------------- 52,65, 72,148 

0-19 .... --------- ------- -------- --·- ----------------- 62, 72,148 

0-20------------------------------------------------------- 62, 72,148 

P-3 ..•.......... -..... -.............................. 1::6,221,708,787 

P-4 ................... 64, 1c6, 221,260, 337-33X, -"79, 6:J3-6o'!, 639,701-702 

P-5 .........•............. 6-1,156,221,269,337-338,708,785-787,787-788 

P-6............. . ................ 64, 156,221,355,394-395,708, 781<--791 

P-7 ...•.....•...•. 64, 1;56, 221,353, 35.1, 394-395,500,543-544,708,788-791 

P-S ....•...••..••••••...........•....•............... 64,269,338,353, 

355, 390-394, 500, 544-5·15, 549, 576,579,634-63.5,639, 70Q-701 

P-9 ......•..••..•.......• 225,264,269,336-337,353,355,390-394,796,836 

P-10 ..•............•.......•. 22!i, 264-265,269,336-337,353,355,390-394 

P-11 .......•........... 62, 72,148,225,264.-265,269,336-337,355,390-:194 

P-12 ..•...........................• 62, 72,148,225,264-263,269,3:16-337 

P-13 .........•.........................•...... 62, 72,148,225,264-255 

l'-14 ..•. -------------------------------. ·- -- 62,64,'72, 148,225,264-265 

P-15 .....................................•.•••. 62, 72, 148, 22.5, 264-265 

P-16 ........................................... 62, 72,148,225,264-26.1 

P-17 ........•................... 62, 65, 72,148,156,221--222,225,264-265 

P-18 ..................................... 62,04,65,72, 148,156,221-222 

l'-19 .... ------------------------- (;2,64,65, 72,148,156,221-222,225,264 

l'-20--.------------------------------------------------.--- 62,72,118 

P-22. _ .......... _ ..................................... _ ..... _ .. 62, 6.1 

P-~:l ........................................................... ti2, 65 

P-24 .... _ •..................•.••.• , •....••.•...•.•.......•...•. 62,65 

Q-3.----------- 64, 72, 155,156,221,225,265--266,269,338,355,395,708,791 

Q-4----.---------------.------ 64,156,221,579,635,639,701-702,708,791 

Q-5.----.-- •. ------------------.--------- •. -------.----- 64, 75,155, 

156, 221, 225,266, 269, 340, 579, 635, 708, 790-791, 792, 796, 836 
INDEX. 871 

Blocks, geology of-Continued. Page. 

Q-5 .... 64, 72,155,156,221,225,266,269,338-340,708,790,791-792,796, 1'36 

Q~7 ·•••••••••••·•····•··············••·•· 64,156,221,269,338--340,342, 

353,355,395-396, 579, 635-636,039, 703, 708,792, 796, 836-837 

Q-8 ..••.•••.•................. 64,269,340,342,353,039,703-704,796, &17 

Q-9 ......• 62,225,264-265,269,335-335,342,353,039,703-704,796,837-838 

Q-10 .•..•.•...•......................................•..... 62, 64, 72, 

11R, 225, 264-265, 269, 336-337, 353, 639, 703-704, 796, 836-837 

Q-11 ...•... " ••................•. 62, 64, 72, 148,225,264-255,269,336-337 

Q-12 •.•....•.•.•................ 62, 64, 72, HS, 225, 264-265, 269, 336-337 

Q-13---.- ........ ·- ... -.. -.- .................. 62, 64, 72,148,225, 264-26.~ 

Q-14 ..••...•••.. -- ....... -.... -............. 62, 64, 72,148,220,264-265 

Q-15 ..••.........•............. -............... 62, 72,148,223,264-265 

Q-16 •••.••••...............•..•.... ··- .......... 62, 72,148,225,264-265 

Q-17 •••.••..................... -... 62, 72,148,156,221-222,225,246-265 

Q-18 •.•••.•...•.•..•.•............ -..... -- ... -. 62, 72,148,156,221-222 

Q-19 ·•·•·•···•·••·•······•·•·················· 62,72,148,156,221-222 

Q-20 ..••.......... -.. -· ..... -· ......... ······ .......... -... 62, 72,148 

Q-22 •.•.•............... -....... -••...... -.... -..... -......... - 62 

Q-25 .......•.... ·- --.--- .... -- ... ··- ---- .. ·--- .. --.-- 62 

R-3 ........••... _ .. __ 269,341,355,396-399,500,545-546,549,577,579,636 

R-5 ...•...•.. 266,269,340,355,399,579,636,039,704,709,792-793,796,838 

R-o ...•...•••.. _ ....... ____ .... ____ ..... ___ .......... 792-793,796,838 

R-8 ••.••....•.............. ___ .... __ ..........•.... _ .• 62,639,703-704 

R-9 •••••••..•........ _ ...... __ . _ ....... __ . 62,225,264-265,639,703-704 

R-10 ••••••...••..........• 62,64, 156, 222-224,225,2G4-2fi5,639,703-704 

R-11 ••..•..•••............. _ ..•.. _____ . 62, 64,156,222-224,225,264-265 

R-12 •..............•. __ ...... ____ .... _____ 62,64,222-224,225,264-265 

R-13 ..••••...•..... _ •.................. 62, 64,156,222-224,225,264-265 

R-14 ....•.•...... _ ....... ____ ............. 62,156,222-224,225,264-265 

R-15 ...•.• __ ........ _. _ .... ______ . _ ...•••• 62,156,222-224,225,264-265 

R-W .........• _ ..... _ ......... 62,156,222-224,225,264-265,796,838-839 

R-17 .....•.•.. _ ........•...... 62,156,222-224,225,264-265,796,838--839 

R-18 ....•...••................... ____ ....... _ 62,796,838--839 

R-19 ....••..•.. _ ................... ____ ...... ___ . _ ... 62,796,838-839 

R-21. ...•.•..•........ __ ....... _. ____ .. __ ... __ .. 796,838-839 

R-22 ••••.....•....... __ ........ _ ....... 62, 65,639,704-705,796,838--839 

R-26 ••••.•...•.... _ ...... ________ ... __ .. _ ...... _ 62,709,793 

R-27 ...•.......... ___ ........ _____ 62,506,546-547,549,577-578,708,793 

S-10 .•••.•...•.•...... _ ........ __ 156,222-224,225,264-265,355, 39\l--400 

S-11 ..••.•. -.••.•. __ ......... ___ . 156,222-224,225,264-265,355, 39\l--400 

S-12 •...•.......•. ·c ........ __ .. 156,222-224,225,264-26.5,355, 39\l--400 

S-13 .•...•......•................ 156,222-224,225,264-265,355, 39\l--400 

S-14 ...•••...•............•... 62,156,222-224,225,264-265,355, 39\l--400 

S-15 ..••••..•...... _. _ ....... _ .... 62,156,222-224,225,264-265,269,341 

S-16 ............••. __ • 62,156,222-224,225,264-265,269,341,796,838-839 

S-17 .... -- ....... --- .. 62,156,222-224,225,264-265,269,341, 796; 838--839 

S-18 .... -- ........ ____ .. -- .......••...••.•...• 62,269,341,796,838--839 

S-21 ............... ___ ............•.............. _______ . 796, 838--839 

S-22 ....... -...... __ ........... __ .................. 62,796,838-839 

S-26 _ 62 

S-27 ......•.....•...... -· ...... 62,72,155,156,224,269,341,549,577-578 

T-10 ...........•..•............•. ___ .. _____ . 156,222-224,355,39\l--400 

T-11. ..•......... -............... _ ... 156,222-224,355, 39\l--400, 500,547 

T-12 ..•..•.......................... _____ ... 156,222-224,355,39\l--400 

T-13 _ ......•.•.... __ ......•.. _ ....... 156,222-224,355,399-400,500,547 

T-14 ...•.•.......................... 156,222-224,355,39\l--400,500,547 

T-15 ....••.... _ ... __ •........ 156,222-224,269,341,355, 39\l--400, 500,587 

T-16 ........••....•..... -.... 156,222-224,269,341,500,547, 79tl, 838--839 

T-17 ......•..•............. 62, 72,155,156,222-224,269,341,796,838--839 

T-18 ..•••...•.... -........ -............ 62,72, 155,269,341,796,838--839 

T-19 .....•..................••.•.•.•••........ 62,269,341,796,838-839 

T-20.- .................•.......•.........•.... 62,269,341,796,838-839 

U-15 .................................. ____ ...• _ 269,341 

U-16 ...•...... __ ........•............. _____ .. ___ 269,341,796,838--839 

U-17 ....•.....• _ .... __ ......... __ 62,269,341,355,39\l--400, 796,838--839 

U-18 .......... ___ ..... 62,269,341,355, 39\l--400, 500,547-548,796,838--839 

U-19 __ .......•.... _. __ 62,269,341,355,399-400,500, 547-MS, 796, 838-839 

U-20 •........••.......... 269,341,355,399-400,500, 547-.'>48, 796, 838--8:'9 

u -21. ........•.•.. -.............. -.. - . - - - -.. - 500, 54; -548, 796, 838--839 

Bloomington formation ........... __ ... __ .... _ 106 

Bloomslmrg shale ......................... ___ ... _ _ _. ___ . _ .. _. _ _ 239 

Bloyd shale .•••................ _ ...... _ ..... _ 458 

Blue Canyon formation .......... ____ ........ __ ..... _. _. _ 364 

Blue limestone ...................... __ .... _. _______ . __ ... _.. 368-369 

Blue Mountains, geology of.. .. _ .. _.__ _ ___ 355, 380-:JSl 

Blue Mountain series ...... _ ..... _ ......... __ ...... _ ...... 640-042. 717 

Blufftownmarl ..•••.............. _____ .......... ______ ...... _ _ 657 

Boggy formation ................................. __ .. 458. 462 

Bohio formation ................................... _ ......... _. 711-712 

Page. 

Bohm, Joh., cited................................................ 585 

Balsa quartzite ..........................................•••.•... 74-75 

Bolton gneiss ...............•.................................. 471-472 

Bonair conglomerate_ ........••........................ 448,449,451,452 

Bonaire, West Indies, geology of. ... __ ... ____ ... ___ ........ __ .. 637,039 

Bonaventure conglomerate ............. __ ............. 254-255,423-424 

Bone Valley gravel ................... _ .............. __ ... _...... 811 

Bonneterre limestone ................. _ .............. __ ..... _.... 104 

Book Plateau, Colo., geology of. ...... _____ . ___ .... _ ..... _ .. 706,759-760 

Boone limestone .. _ .......................... __ ....... _ .... __ .. 411,458 

Booneville group ............................... _. _ ..... _ .... __ .. 458 

Boscabel beds .... _ .......................... _ ..... _ ..... _ ..... . 519 

Bose, E., acknowledgments to ..... ___ ..... _._ .................... 34,56 

cited .... _._ ...... __ ......... _ .... _____ . 504,551,586-589,591,596-597 

publications by ..... _____ ....... _._ .... __ .... __ ..... _ ...... 644,842 

Bossard ville limestone .................. _ ............... ___ 238,239,241 

Boston Basin, geology of. .... _ _ ____ ..... _ ........ 114-116 

Bosworth formation ....................... _ ...... _.............. 154 

Boutwell, J. W., acknowledgments to ...... ___ ................... 34,59 

cited ..... _ .. ___ .... _____ .. __ . _ ..... _ ..... __ ....... _ ........ 49-J, 530 

publication by .... _ ........................... __ ..... _....... 842 

Bowden series ..... _ ................•...... __ .... __ .... 540,719,799-801 

Bowie shale ...•...............•............. __ ..... _._ ... _...... 671 

Bowman, Amos, acknowledgments to .. __ .. _.......... 34, GO 

Bownocker, J. A., acknowledgments to ..... ___ .... __ ..... _._.. 34,58 

Bow Rh·er group, ............................. _ .... _ ..... _ . . . . . 154 

Boxboro limestone ...... _ ........................ _.............. 471 

Bragdon formation ............................................ 373,376 

Brainard, Ezra, cited .................... __ ..................... -- 187 

publication by ............•.•......................... _...... 843 

Brainard, E., and Seely, II. M., cited ....... __ ....... _ .... __ .... 125-126 

publication by ..... _ ................................... __ .... 843 

Braintree shale ....... _ . _. _ ........... _ .... ____ ........... 115,145 

Branner, J. C., acknowledgments to ............................. 34,56 

cited .. _ .. _ .. _ .. __ ..................... _ ..... _ ...... 458,459, 669-()70 

pnblication by ...................................... __ ....... 843 

Branner. J. C., and Simonds, F. '\V., cited .... __ .... __ 458 

Branner, J. C., and others, publication by ......... _ ...... __ ...... 843 

Brasstown schlst ........................................ __ .. .. . . 98 

Braxton formation .... _.............................. . _ .. 444,446-447 

Brazil formation .. __ ...................................... _ .... 457-468 

Breger, C. L., cited.... . ................ _ .... 528--529 

Brentwood formation........... . . . . . . . . . . . . . . . ................. 4.58 

Bretonian series ..... ___ ..... ___ ....... _ .... __ .............. 139,147 

Brevard schist. .............................................. -... 97 

Briceville shale.................................................. 451 

Bridge Creek forma lion . . . . . . . . . . . . . . . . . . . . . . . . • • • ••• . . . . . . . . . . . . , 773 

Bridger formation ................. _ ........ 10,676,706,758,759,765-766 

Brigham formation .........................•....••••..... ___ .... 106 

Brimfield schist ..................................... __ ... _._ 472 

Bristol Bay, geology at.. ............... __ ................ __ 796, 835-83G 

British Columbia (M-0 8-9), authorities on .... 60,219,220,333,390,392, 

538,541,542,543,573,574,576,625,628,693,694, 698--700,785, 8~5 

geology of __ . _ .................•... _ ......... _ 11, 

13, 14, 64, 156, 21\l--220, 225,203,269, 337,342,352,353,355, 390-

392, 500, 538-539, 541-543, 549,573,574,576,579, 623-()28, 630-

031, 034-635, 039, 693-()94, 698-700,706,780-781, 785, 796. 835 

publications on ...................... 32_, 34-39,41-44,46,49-51,54,56 

Sec also Pacific coast; Hocky Mountains of Canada. 

British Honduras (E 16), authorities on ....... _ ............ _. 355,357 

geology of. .. ___ ... _ .............. ____ . _ ..........•...... 64, 355, 357 

See also Central America. 

Brito formation .................................... _ .......... 709-710 

Broadhead, G. C., cited... . .. ___ .............. __ ....... .. 103 

publicationby.. -----·········- -------·--················ 843 

Brock, R. W., acknowledgments to ........ _ ..................... 34,60 

cited ........... -- ............. -.................... _____ 69,221,392 

publications by, list of ........... ___ .................. __ .... _ 843 

Bronson limestone •.••••••••.••••••••••••.••••............... _._. 458 

Brooks, A: II., acknowledgments to ••••..............•..... _ .. 34,59,61 

cited ............•.. 266,338,340,353,399,528, 632-()33, 701-702,792,836 

publications by ................. __ .. _ ........ ___ ...... ___ ._ 574,843 

Brooks, A. H., and Kindle, E. M., cited .... ___ ..... 395,635-6.36,704,792 

publications by, list of. ....... _____ ..... __ .. __ ....... ____ ._ 843 

Brooks, A. H., and Prindle, L. M., cited......................... 221 

Brookville coal ••.•.................................. _____ ... _. 435,458 

Brookwood coal ..••....................•............. _. ___ . _ _ _ 454 

Brown, C. B., cited •••..... __ .................................... 720 
872 INDEX. 

Page. 

Brown, C. W., acknowledgments to ... ___ ._ ...... ___ .. ___ .... 34.57,59 

cited .. _ .... _._. ____ ._ .... _. _____ .. __ .. _............ . . . . . . . . . . 350 

Brown, N.H., cited.......... ___ .. .. . .. . 531 

Browns Park group ............................ _ .. _. _ 759 

Brownsport formation ............................. _ 235 

Browntown sandstone •.........•.............................. 438,653 

Brule clay .......•.••.•...•••....•................ _. 10, '706, 770,821-822 

Brummel, H. P. H.,cited ••..... ---·---·---------- ------------- 291 

publications by.·············-·-··---- __ ... _ ..... _. ___ ..... 293,843 

Brunswick group ..••.•..•••...•••.••.•......... _____ . _ 522-524, 52&--527 

Brush Creek limestone ..•..................................... 4.1&--437 

Bryson formation ....................... _ .... _ .... _ _ ______ 444,450 

Buckley, E. R., acknowledgments to ... _ _ ______ . _____ ... ___ . _ 34,58 

cited ........ ___ . ___ . ____ ... _______ ................ ___ ........ 278 

publications by ... _ _ __________ ......... ____ . . . . . . . 105, 843 

Buda limestone .........•....................... ____ ...... 596,604. 649 

Buehler, H. A., acknowledgments to.. ___ . _ .............. 34,58 

Buena Vista sandstone .... ___ ............... -- ............ __ .. 415,417 

Buffalo sandstone ................................. _. _. _......... 436 

Buff Bay formation---- ............................ _. ... .. .. ... 800 

Bull Mountain field, Mont., geology of. ................ _......... 776 

Burchard, E. F., acknowledgments to ........................... 34,57 

Burchard, E. F., and Grant, U.S., cited ......... _ .. _ ....... _ .. 18G-183 

Burchard, E. F., and others, cited ....... _ ........ __ ._ ......... 164--165 

publication by . _ ......... _.. .. .. . .. . • ••• • . . • 843 

Burches Ferry formation. See Peedee formation. 

Burckhardt, C., cited .............................. 552-554,592,644,648 

publications by, list of....................................... 843 

Burckhardt, C., and Scalia, S., cited .............. _ .......... _. 504--505 

publication by ...... _............ .. .. ... .. .. ... .. .. ... 843 

Burlingame formation ......................................... 458,465 

Burlington formation .................................. 401,408,411,458 

Butler, B. R., acknowledgments to.... . . . . .. . . . . . . . . . . . . . 34,59 

cited........................... ........................... 284 

Butts, Charles, acknowledgments to ..... _.......... . _. _ 34, 56,59 

cited ......... _ .. __ ......... __ ._. __ ..................... 294,402-405 

publications by..... . . _. __ ...... 455,843 

Butts, C., and others, publication by ................. _.. 843 

Buxton formation................................ 458 

c. 

Caballos Mountains, Tex., geology of.. . ................ 156,158 

Cacapon sandstone .. . .. . . . . .. .. . . . . . . . . .. . . .. . . . . . . . . 231 

Cache Creek group ......................................... 353,390-392 

Cairnes, D. D., acknowledgments to..... . ...................... 35,60 

cited .......................... --............................. 635 

publication by .. .. . . . . . . .. . . . . . . . . . . . . .. . .. . . . 843 

Calaveras formation ......................... ---......... 364,555 

Calciferous formation .. 125-126,153, 192,194--195,197, 20G-201, 204--205,209 

See also Beekmantown formation. 

Calhoun shale ................................................. 458,465 

California (I-K lG-11), authorities on ............ 21,56--57,98-102,175, 

242,363,364, 373-376,505,519,520,521,522,527, 554--555, 561-

564,615-617,617--620,667--670,750,751, 752, 754,814--817,819 

geology of. ................ __ ........ __ .................... 9-12,1.5, 

17, 64, 72, 98--102, 156, 175, 225, 242, 269, !»;8--289, 355,363-364, 

373-376, 494, 500, 505-506, 519-522, 527-528,549,554--555,561-

565, 569--615, 617--621,637, 667--670, 706, 75G-754, 796, 814--820 

publications on ............... _ ....... __ 31-34,36--45,47--48,50,52-.55 

See also Pacific coast; Sierra Nevada. 

Calkins, F. C., acknowledgments to ........................ 35,57,58,59 

cited ................................... 128--130,381,571,621,686,776 

Calkins, F. C., and Smith, G. 0., publications by, list of.... 860 

Callaway limestone............................... 278 

Caloosahatchee marl............. .. .. .. . . . .. . . . . . . . . . . . . .. .. . . . 81()-811 

Calvert, W. R., acknowledgments to ..... ______ ......... __ ...... :\5,58 

cited ....................................................... 686--687 

publication by ...................... _ ... __ .................. 843 

Calvert, W. R., and Stone, R. W., cited ........................ 687--690 

publication l.Jy . . . . . . . . . . . . . .. . . . . . . .. . . . . . . . . . . . . . . .. . . . 861 

Calvert formation ........................................ "74&--747,749 

Calvin, Samuel, cited................................. 180,242-243,290 

publications by, list of ...... __ ..................... __ . 843 

Calvin sandstone . . . . . . . . . . . . . . . . . . . . • • • • • • . • . . . . . . . . . . . . . . . . . . 458, 463 

Cambrian and Lower Ordovician, content of. .................... 13,72 

distribution of.. ......... __ ............ __ ..................... 13,72 

detailsot ............................................... 72-155 

map showing .................................... __ ....... 73 

representation of, ou map ............. __ .................. 13, 17,72 

Page. 

Cambndge formation ... __ ................. _._ .. 436,470,717-718,719,800 

Camden chert, . . . .. .. .. . .. .. .. . . . .. .. . . . . .. .. 275-276 

Campagrande formation . .. .. .. .. .. .. .. .. . .. . . . . . .. .. .. . 597-598 

Campau formation ....... _._ ........................... __ ... __ ... 816 

Campbell, H. D., acknowledgments to.......... 35,59 

cited ........ __ .... _ .......................... _ .... _ 174--175 

publication by.................................. 843 

Campbell, J. L., publications by ...... __ ........ 174,843 

Campbell, M. R., acknowledgments to .............. 21,35,56,57,58,59 • 

cited........... . _. 94,174,231,287,406,449, 4.51, 695 

publications by .. _ ................... _ . _ . . . . . . .. . 173, 286, 843 

Campbell, M. R., and Mendenhall, W. C., publication by....... 843 

Camsell, Charles, acknowledgments to ....... _ ..... _ .. _ ........ 35, 60,61 

cited ............................... 338,340,623--624, 703_, 78()-781,837 

publications by, list of.. .... ____ ._. 843 

Canaan dolomite .................................. _ ..... _._. 194,418 

Canada, authorities on. . .. . . ... _ ..... __ .. _ ...... _ . .. . . . 60, 192 

geology of.............. . ....... ___ ..... 10, 11, 12, 13, 14, 15,192 

publications on ..... _ ....... _. 33,34,37,45, 51 

See also partic·ular provinces; Rocky Mountains of Canada; etc. 

Canadian Geological Survey, bibliographies issued by... 6 

on classification of pre-Cambrian rocks. __ .. 65-70 

Canadian Rockies. See Rocky Mountains of Canada. 

Canadian shield, geology of ....... _. 148 

Caney shale .......................... ___ ..... __ . 458,459 

Cantwell forma,tion ............ ____ ............. _ ... _. __ ....... _. 338 

Canyon formation ........................................ __ ..... 429 

Cape Breton, authorities on... . .................... _ ..... _. 145 

geology of............ . ................. _. _ .... 72,136,145-147 

Cape Fear formation ................................ _ ....... _ .. 605,613 

Cape Girardeau formation ....................... _ .............. !69-171 

Cape Horn slate................. . . .. . . . . . . . .. .. . .. . . .. .. .. 364 

Cape John sandstone............. . .. .. .. .. .. . ..... .. .. ........ 386 

Cape Lisburne region, authorities on ............... _ 61,341,39&--399,636 

geology of. ............. _ ....... 269,341,355,39&--397,549,577,579,636 

publications on . ... . . .. .. .. . . . .. .. . . . . . . . . 35,44 

See also Alaska, northwestern; Alaska, northern. 

Cape Rawson beds............................................. 17 

Cape Thompson, geology near....... .. . . . . . . . . . 355, 397-399, 500, 545-546 

See also Alaska, northwestern; Alaska, northern. 

Capitan limestone .......................................... 75,359,474 

Cap Mountain formation .. ___ ....... ___ .......................... 77-79 

Capps, S. R., and Moffit, F. II., publication by..... 856 

Carbondale formation ........................... _ .. . .. . . . . 467, 468 

Carboniferous rocks, undivided, content of. . . . 12, 17, 355 

distribution of. ..................... __ ..... 12,17,355 

Carboniferous rocks, distribution of, details of..... 355--400 

distribution of, map showing............ 356 

representation of, on map .......... _....... . .... 12,355 

See also Permian; Pennsylvanian; Mississippian. 

Cardenas division...................... . ...... -----. .. .... 591 

Cardiff shale ........................................... ___ ...... 247 

Caribbean coast, geology of........... . . . . . . . . . . . . . .. 11 

See alsg Yucatan; Panama; Central America; South America. 

Caribbean group . .. . . .. . . .. . .. .. . .. .............. _ .. 344,715 

Carlile formation ...................................... 662, 672, 685, 691 

Carlinville limestone ................................ _ ........ __ 467,468 

Caroni series........... . ........ ___ ............. 708--709,714-715 

Carrizo sand .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . 726 

Carters limestone . . .. .. . . . . . . . . . .. . . . .. .. . . . . . .. . . 168 

Carthage limestone . . . . . . . . . . . .. .. . . . .. . . . . . . . .. 468 

Cartography, restrictions of....... 7-8 

Cascade Range, geology of........ . .... 706,774 

Case, E. C., cited .. _._ .. _._.. . ..... ·477, 4R9-490 

publications by, list of...... 843 

Caseyville conglomerate . . . . . . . . . . . .. .. . .. . ........ _.... 468 

Cashaqua shale..... . . . . . . .. . . . . . .. . . ............. __ .. 307 

Cason shale.......................... 169 

Caspar formation .. . . ........................................ _ 531 

Cassin formation . .. . .. . .. . .. . . . . . . . . . . . ............... 12&--127 

Castile gypsum . _............................. . ...... 360, 474 

Castillo, A. del, and Aguilera, J. G.,cited. ................. 551 

publication by .. _. _ . . . . 843 

Castle Hayne limestone .. ___ .................................... 748 

Castle Mountain_group . _..... 145_.154, 258,388 

Catadupa formation.... . .... _. __ .............. _ .......... 71R, 720 

Catahoula sandstone .............. _ .. _._.......... 724,728--731,804,805 

Cat Head limestone ................ _ ........................ __ 218-219 

Cathedral formation . . . . . .. .. . .. .. .. . .. . . .. . . . .. . .. .. . .. . .. . .. .. . 154 
INDEX. 873 

Page. 

Catheys limestone.............................................. 168 

Catron formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 450 

Catskill formation . . . . . . . . . 12, 294, 297 

Cattaraugus beds _ _ _ ...... __ ... _ ..... _ . _. . 297 

Cavanial group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45R 

Cave Creek formation........ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 487 

Cawcaw formation ...... . 737 

Cayuga formation.. . .............. 13,245 

Cayuta shale.... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304 

Cedar formation . . . ......... ~ ................... 374,520 

Cedartop gypsum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 487 

Cedar Valley limestone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290 

Cedarville limestone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234 

Central America (C-D 1~17), authorities on..................... 56 

geology of...... 9, 10, 11, 12, 16,355,500-503,706,794 

publications on, lists of...... . .......... 31, 40, 42, 43, 50, 52, 53,56 

See also particu.lar countries. 

Central limestone.......... . . . . . . . . . .. .. .. .. . . .. . . . . . . . . . . 168 

Cera tops beds...... . . . .... .. .. .. .. .. . . . 10 

Cerro de Oro formation..... . .................. 10. 706, 708 

Chadron formation.......... . .. 10,706,769,770 

Chagrin shale.... . . . . .. .. .. . .. . . . . . . . . . . .. .. . .. .. . .. . . .. . .. . . .. .. 421 

Chamberlin, T. C., acknowledgments to.......................... 35 

cited ........................................ 69, 118-120, 176, 183,290 

publication by......... . . . . . . . . . . .. .. . . . . . . . . . . .. .. .. . . . .. .. 844 

Chamberlin, T. C., and Salisbury, R. D., cited ..... 242,408,410,412.414 

publication by. . .. . .. . . . . .. .. .. .. .. . . . . . . . . . . . . . . . . . .. . .. . 844 

Chambersburg limestone ...................................... 109,177 

Chambersburg quadrangle, Pa., geology of.............. . .... 107-109 

Chance, H. M., cited ........................................... 509-510 

publication by............................................... 844 

Chandalar-npper Koyukuk region, authorities on • . . . . . . . 61 

publications on .. . . . .. . .. . . .. . .. . . ......................... 47.50 

Chandler beds . .. .. .. . . . . . .. . .. . . . . . . .. . . .. .. .. . . . . . . .. .. .. .. .. .. 464 

Chaney gypsum . . . . .. . . . . . . . . .. . . . .. .. .. . . .. . . . .. . .. .. . . .. . . 487 

Chanute shale ................................................. 458, 464 

Chapel ton formation ........................................... 718, 720 

Chapman, E. J., cited.............. . . . .. . . . . . . 245 

publication by............... . . . .. . . . .. . .. . 844 

Chapman sandstone . . . . . . .. . . . . . .. .. .. .. . .. . .. .. .. .. . .. . .. . . . . 328, 329 

Charleston sandstone .......................................... 445,447 

Charlton formation.............................................. 810 

Chat River limestone . . . . . . . .. .. . .. . . .. . .. . .. .. . .. . . . . . . . . .. .. .. . 253 

Chattahoochee formation .................................. 741,742, 744 

Chattanooga shale .......... 231,234,274,275, 277-278,287-288,405,413,458 

Chautauqua group............................................... 297 

Chazy formation .................................... 13.,17, 153,164,183, 

184,187-188,191,194,195,197,200-201,204-205,209-210,217 

Chemung formation ................ 12,291,293, 294,297,304,309-313,413 

Cherokee shale ......................................... 457-458,465-466 

Cherry Creek group...................... . ........ 14, 62,64 

Cherryvale shale. . .. . . . .. . .. . . . .. . .. .. . . . . .. . .. . . .. . .. . .. .. .. . 458, 464 

Chesapeake group................................ 74~749 

Chesterfield group . . . . . . . . . . . . . . . . . . . . . .. .. .. .. .. .. .. .. . . .. .. .. .. 519 

Chester formation ................................. 401,407-413,418,458 

Chester Valley limestone ...................................... 112-113 

Chiapas (D-E 15), authorities on ........ 427,503,504,525,585-587, 721,797 

geology of ................................................. 425-427, 

500,503-504,579,585-587,590,644,706,721-722,794,797 

See also Mexico. 

Chichagof Cove, geology of. .................................... 708, 782 

See also Alaska Peninsula. 

Chickamauga limestone .......................... 9()-.94, 164-165, 173-174 

Chickies quartzite . . .. . . . .. . .. .. .. .. . .. .. .. . .. . .. .. .. .. . .. .. . .. .. 112 

Chico formation ..... 11, 615-617,621, 667-670,750, 753, 754,772,815,816.818 

Chicopee shale .. . . .. .. .. .. .. . . .. .. .. .. .. .. .. . . . . .. .. .. .. .. .. .. . • 532 

Chihuahua (E 15), authorities on................................. 21 

geology of. ............................................. 591, 59~598 

Chilhowie group .. .. .. .. .. .. .. .. . .. .. . . . .. .. .. . . . . . . . . . .. . . . . 13, 89, 145 

Chinitna shale •- ................................................ 11,549 

Chipola marl.. ................................................. 741, 743 

Chisna formation . . .. . . . . . .. . .. . . .. . . . .. . .. .. . . .. .. .. .. .. . .. . .. .. 338 

Chisos region, Tex., geology of. ................................ 595-596 

Chitina Valley, authorities on ............................. ·....... 61 

publications on ........................................ 47, 48, 50,52 

Chitistone limestone. . . . . . ............................... 394, 544 

Choctawhatchee marl ......................................... 808-809 

Choptank formation ................................... : ... 746,747,749 

Chouteau formation ............................................ 408,409 

Page. 

Chugwater group .............................. 492,495,516,530-531,678 

Cieneguita formation ........................... ~- ............. 551-552 

Cimarron series............................... __ .. .......... 487 

Cincinnati series ................................... 165-168, 172,176,317 

Cintura formation....... . . . . . .. .. .. .. . .. .. .... .. . .. ...... • 592 

Cisco formation................................... . ..... 429,476 

Citico conglomerate ............................................. 94-95 

Claggett formation... . .. ...... . . . . .. .. . .. .. . .. . . . 11,637,687-690 

Claiborne group ................... 723-724, 72~727, 731,734,735-738,748 

Clallam formation............................... . . . . . . . . 778, 832-833 

Clapp, C. H., acknowledgments to............ 35, 57, 59,60 

publications by, list of. . .. .. .. . .. .. .. . . 843 

Clapp, F. G., acknowledgments to............................... 35 

cited .. . . .... .. .............. 351,683-684 

publication by............................................... 844 

Clapp, F. G., and Fuller, M. L., publication by .. .. .. .. 849 

Clapp, F. G., and Matson, G. C., cited.... 74()-.741,808-811 

publication by .. .. .. .. .. . . . .. . .. . .. .. . .. .. . .. .. . 855 

Claremore formation............................................. 461 

Clarion limestone .. .. .. .. .. .. .. .. . .. . .. . .. .. . • ... .. .. . .. .. . .. .. .. 435 

Clark, W. B., acknowledgments to ......................... 35,57,58,59 

cited ....................................... 527,608-614,670,745-749 

publications by ............................................ 611,844 

Clark, W. B., and Bibbins, A., publications by, list of........... 844 

Clark, W. B., and Martin, G. C., publication by.................. 844 

Clark, W. B., and Mathews, E. B., publication by............... 844 

Clark, W. B., and Miller, B. L., publication by................. 844 

Clark, W. B., and others, publications by ..................... 844,859 

Clarke, J. M., acknowledgments to............ . ....... 35,58,60 

cited ....... 184,245,254,285,297,299-300,307,308,312,334,335,423-424 

publications by, list of. . .. . .. . .. .. .. . .. . .. .. . . . . .. . . . 844 

Clarke, J. M., and Ruedemann, R., publication by........ 844 

Clarke, J. M., and Schuchert, C., publication by................. 844 

Clark formation ............................................... 445,446 

Clarno formation ...................................... 772-773,826,829 

Classification, departures from. . .. . . . . . . . . . . . . . .. . .. .. . .. .. . . .. .. 6 

system of.................................................... 6 

uniformity in, impracticability of, over continental areas..... 8 

Clayton limestone ............................................. 731-732 

Clear Creek limestone ...................................... 276,278,279 

Clear Fork formation .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . . . . . .. . . . .. .. 476 

Clearwater shale ............................................... 699-700 

Cleland, H. F., cited......... . . . . .. .. . .. .. ............ 304 

publication by .. .. .. . . . .. . . . . . . . . . . .. .. . . .. . . . . .. . . .. .. . 844 

Cleveland shale ............................................... 414,421 

Clinch formation .......................................... 23()-.231, 237 

Clinton formation ............................................ 164,191, 

196,225,229, 23()-.232, 234-235,236,237-238,239,244-245,251,282 

Clipper Gap formation........................................... 364 

Cloverly formation ............................................ 685,690 

Coahuila (G-H 13-14), geology of. .................. 549,552-554,591,648 

See also Mexico. 

Coaledo formation .. .. .. .. .. .. . .. .. .. .. . .. .. .. .. . .. .. .. . .. .. . .. .. 771 

Coal measures. . . . . . . . .......... 12, 439-442, 45H58 

Coal series .. .. .. .. .. .. . . .. .. .. .. . .. . .. .. . .. .. . .. . .. .. . . . .. .. . .. .. 649 

Coastal series ................................... :. .. . . .. .. .. . .. .. 640 

Coast formation ........................................... 346,718-719 

Coast Range, geology of.................. 554-555,794,815-818,825-826 

Cobb coal............................ . . . . . . .. .. .. . .. .. .. 454 

Cobleskill formation .. .. . .. . .. .. . .. . . . .. .. .. . . .. . . 245 

Cobre formation ............................................... 720,721 

Cochran conglomerate ..................................... 91-92,95,96 

Cockerell,~·- D. A., publications by ............................ 759,844 

Cockfield formation ............................... 724, 72~727, 737,738 

Cocni quartzite.................................................. 582 

Coeymans limestone ....................................... 294,297,300 

Coffee sand .. .. .. .. . .. . .. . .. . .. .. . . .. .. . . . . . ................. 653, 655 

Coffeeville formation . . .. . . .. .. . . . ........................ 458, 463, 464 

Cohansey sand ................................................ 746,749 

Cold brook group ...................................... 137-138, 146, 147 

Coldwater formation .......................................... 42()-.422 

Collier, A. J., acknowledgments to ......................... 35,56,58,61 

cited ....................................... 341, 39G-397, 577,636,702 

publications by, list of.................................. 844 

Collier, A. J., and Smith, C. D., cited............................ 777 

publication by . .. .. .. • . . .. . .. .. .. .. .. .. .. . . . . . . . . . . . . . 844 

Collier, A. J., and others, cited................................... 458 

publication by .. .. .. . • • • • .. .. .. .. .. .. .. .. . . . . . . . .. . . . . .. .. . . 844 

Collier shale ................................................... 16o--161 
874 INDEX. 

Pa.ge. Page. 

Collingsworth gypsum ....................... :................... 487 Corniferousformation ...................................... 241-292,301 

Collins, W. H., ackno,vledgments to .................. : .......... 36,60 Correlation, discnssioJO of......................................... 5 

Colombia (B-C 18), authorities on ..................... 581,582,708,796 Corry sandstone ......................... ." ..................... 414,421 

geology of ................... : .... 10,04,579,581-582,706,708,794,796 Corryville formation .................................... ___ ...... 172 

See also South America. Corwin formation .............................................. 577,636 

Colora(io (J-K 12-13), authorities on ............ 21, 57,102, 109, 179, 284, Costa Rica (C 16-17), authorities on ....................... _...... 5&5 

285,367-372,474,480-483,490, 494, 495, 500, 510-513, 516,556, geology of ... : .............................................. 579,585 

557, 566, 606,607, 660, 670-674, 678, 755-759,760-764,770,813 See also Central America. 

geology of ....................................... 10, 11, 13, 14, 64, 72, Cottonwood formation ..................................... 145,458,465 

102-103, 156, 109, 179,284-285, 355, 367-372, 474,479-483,490- Cox formation ............ ~ ..... _ .............................. .197-598 

492, 494-495, 510-512, 549, 550-561, 560-507, 579,600-607,637, Cragin, F. W., cited ............................... , 487-489,554,614-615 

648, 660-667, 670-674, 678-679, 706, 755-764, 769-770, 813-814 publications by, list of....................................... 845 

publications on .......•••••••.......... 33, 35, 36,38-44,49-52,54,55 Crandall, Roderic, ackilOwledgments to ......................... : 36,56 

See also Great Plains; Rocky Mountains. Cranston formation ................. .-........ .... .. .. .. .. .. .. .. .. 469 

Colorado group ................ 662,670-671,673,676,678,682,685-089, 767 Crescent formation .. .. .. . .. .. .. .. .. .. . . . .. .. .. . . .. .. .. .. .. .. .. .. 778 

Color printing, method of •.••............ _....................... 23 Cretaceous system. See Earliest Tertiary or latest Cretaceous; 

Colors, allotment of, to particular rocks .......................... 27-29 Late Upper Cretaceoll?; Upper Cretaceous; Montana 

combinations of .............................................. 22,30 group (coal-bearing portion); Lower Cretaceous. 

contrast in, obtaining of...................................... 22 C'rider, A. F., acknowledgments to ........................ 36,56..58, 723 

value of.:................................................ 29 cited .. ,...................................................... 732 

overprint.ing of. ................. : .. : ........ ; ................ 23,30 publication by ....................................... _...... 845 

Color schemes, principleS of ............. , ... , ........... 21-23,26,27-30 Crider, A. F., and Johnson, L. C., cited ........................ 737,738 

usages in .............................. :.· ..... __ .............. 23-27 publication by............................................... 845 

Colors used on map, significance of............................... 9-16 Crider, A. F., ar d Stephenson, L. W ., cited ............ __ -__ ...... ·724 

succession of ........ : .. , ......................... _ . .. .. .. .. .. 27 Crosby, W. 0 ., acknowledgments to.. . .. .. .. .. .. .. .. .. .. .. .. .. .. 36,58 

Columbia lava ................. :· ..... :".......................... 829 cit~d ............................................... 114-116, 169,683 

Columbus limestone ................. ~ ... : .. ; ................... 315,317 publications by .......................................... :. 470,845 

Colville River basin, ·See Endicott Range, etc, Cross, Whitman, acknowledgments to ............................ 36,57 

Colville series ...................... , ...................... 792-793,838 cited ............. : . ................... 102-103,367-368,370-371,372, 

Comanche Peak·!iJp.estone ..................................... 598-599 480-484, 490-492,511-518, 550-561, 660, 751)-7 56, 761-762, 769 

Comanche series ....... : .. ...... II, 579,591,593,595-598,601,604,607,608 publications by ............................................ 764,845 

Compilation of data; assistance in................................ 5 Cross, W ., and Rowe, E., publication' by......................... 845 

method of ............. : .............................. ____ .... 5 Cross, W., and others, publications by ......................... 845,849 

classification of.. ........................................... 124, 145 Cross Plains sandstone .. .. .. .. .. .. .. .. .. .. .. . . . .. .. . . .. .. . .. .. .. 458 

Conasauga formation ................................ 85-86,89-91,93,94 Crystal Mountain sandstone ........... · ................. _ ...... _160-161 

Concrete shale................................................... 458 Cuba (F 17-18), authorities on ...................... 21,348,552,722,803 

Conemaugh formation ..................... 420,431-432, 43fl-437, 443, 458 geology of. .............. 13,342,348-349,552,706,722-723,794,803-804 

Congaree fonnation .. .. .. .. .. .. .. .. .. . .. .. . .. .. . .. .. .. .. . .. .. .. 736, 737 See also West Indies. 

Connecticut (K 18-19), authorities on ............... __ ...... 57,192,532 Cuchara formation ............................................. 758-759 

geology of .................... , .............. 64, 1.5G, 192, 1!)4, 500,532 Culebra formation ................................... '.......... 713-714 

publications on .............................. 32, 37, 39, 40, 43,50, 52 Cumings, E. R., cited ................................. :::· ...... 171-172 

See also Atlantic coast; New England. publications by ............................................ 187,845 

Connellsville sandstone .. .. .. .. .. .. . .. .. .. . ..... .. . .. . .. .. .. .. .. .. 436 .Cumings, E. R., and Prosser, C. S., publication by .......... --.. 857 

Connoquenessing sandstone . . .. .. .. .. .. .. . .. .. .. .. .. .. . . . .. .. .. . 434 Cummins, 'V. F., acknowledgments to.. .. . .. .. .. .. .. .. .. .. .. 30, 59, 130 

Conococheague limestone .......................... _ ..... _. _ ... 109=110- ~~cited ....................................... 429-430,476-477,479,507 

Conrad, '!'. A., publication by ........................... __ .. __ __ 844 publications by, list of.. ................... :.................. 845 

Continental Eocene, content of. ..................... : .. __ .. _. __ .. 10 Cunningham-Craig, E. H., publications by .................... 584,845 

distribution of. ......................................... __ .. _ 10 Cura~ao, West Indies, geology of.. .... ,; ...................... : 637,639 

representation of, on map ....................... __ ....... ____ 10 Curlew limestone .... : .. ..................................... :. .. 468 

Continental Oligocene, content of. ............................ __ _ 10 Cushing, H. P., cited ..................... · __ 120-123,126-127, 184-187,204 

distribution of ............................................. _: 10 · publications by ....................... : .................... 187,845 

representation of, on map .... ~ ........................... ____ 10 Cushing, R, P., and Ulrich, E. 0., cited ........................ 180-187 

See also Earlier Tertiary. publications by ............................................ 124, 862 

Contributions, sources of ......................... · ............... 30--56 Cusseta sand .............. , .................................... 055, 657 

Contributors, acknowledgments to ....................... _ ....... 30-61 Cussewago sandstone ..... : .. ................................ --.. 414 

Controller Bay region, authorities on .......... _ ............. : ... · 61,788 Cutler formation ....................................... 371,480-485,558 

geology of .............................. __ .............. 708, 788-789 Cuyahoga shale ................................ 408,414,415-416,422,430 

publications on ............................................ _ ~ 47 Cypress Hills, Saskatchewan, geology of.......................... 834 

See also Alaska, southern. Cypress Hills formation ...................... ---- .. , .......... --- 838 

Cook, G. H., acknowledgments to ................................ 36,58 Cypress sandstone .......................................... 411,413,458 

publication by .. .. .. .. . .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 844 

Cook Inlet, geology near.. .............. 225,263,500,541-542,708,787-788 

See also Alaska, southern; Matannska Valley. 

Cook Mountain formation ..................................... 724, 727 

Coombs limestone .. . . .. .. . . . .. . .. .. .. .. .. .. .. . . .. . .. . . . .. .. . . .. . 135 

Cooper, J. G., cited.............................................. 752 

publication by ....................... :...................... 845 

Cooper, W. F., publication by.................................... 845 

Coosa limestone ............................................ · 145;104-165 

Coos group ................................................ 192,250,825 

Cope, E. D.,cfted ...... · .... -~ .......................... 477,517,559,755 

publications by.............................................. 834 

Copper River basin (lower) authorities on .................. 01,337,338 

geology of ........ · .......................................... 337-338 

publications on .............................................. ·50, 52 

Copper River basin (upper), authorities on ... .'................... 61 

publications on .............................................. 47,50 

Corbin conglomerate .. .. .. .. .. .. .. . .. . .. .. . .. .. . . . . . .. .. .. .. .. .. 452 

Cordillera, geology of ............. : ... 12, 1.1, 15, 10, 17, 72,269,355,401,425 

D. 

Dakota formation ...... 11, 53,1, 558,566-567,606,637,660,661-663,665,671, 

. 672-674, 676, 678-682, 691, 693, 694-695, 697,698 

Dale, '1'. N., acknowledgments to .............................. 36,58,59 

cited ........................................... 114,188-189,192-193 

publications hy, list of........................................ 845 

Dall, W. II.,acknowledgmentsto ....................... , ..... 20,36,61 

cited ..................................... 712-713; 721,722,726,730, 

740,771-772,782,783,784,786,787,798,809,823,825-826,832,835 

puhllcations by .. .. .. .. .. . . . . . .. .. . .. .. . • . .. .. .. • .. .. . 683,826,846 

Dall, W. H., and Harris, G. D., publication by.................. 846 

Dall, >V. H., and others, publication by ......•.............. ----- 859 

Daly, R. A., acknowledgments to ............ _. __ .............. --- 36,60 

. Dana, J.D., classification by..................................... 184 

publications by ............................................ 192,846 

·Danville group:.................................................. 458 
INDEX. 875 

Page. 

Darton, N.H., acknowledgments to ................ · 6, 21, 36,56,57,58, 59 

cited ........... , . .. .. .. .. .. .. .. .. .. .. .. .. .. .. . .. .. .. .. .. .. . 102, 

1Hhl17, 118, 173-175, 176, 192, 230-231, 284, 300, 366-370, 

372-373, 443, 491-492, 495, 516, 526-527, 530-531, 533, 567, 

569, 672-673,685,691,7 57-7 58,769-7 70, 777, 813-814,821,822 

publications by ........................ · .... 179,238,286,300,367,846 

Darton, N.H., and Siebenthal, C. E., publication by ........... ·. 846 

Darton, N.H., and others, publications by, list of.. ... :.......... 842 

Davis, W. :IlL, acknowledgments to .............................. 37,57 

publications by .............................................. 532,846 

Dawson, G. M., acknowledgments to ............... : ...... 37,60,61,353 

cited ........................... __ . 68,219-220,222,-264-265,341,3.11-

352,624-630,635, 69Z..:693, 695, 69$-'-701, 703, 787,835,836,838 

publications hy, list of.. .... : ....... :. __ . __ ................... 847 

Dawson, Sir J. W., cited ...... :._ ................... _ ...... 208,264,283, 

293, 327-328, 331-333, 383, 497-498, 535-541' 547-548, 785, 787 

publications by .............................. __ ........ 203,326,847 

Day Creek formation ........... _ ..................... __ .. .. .. .. 487, 488 

Dayton limestone ......... _._ .................................. 23-:,282 

Deadwood formation ................. _ .............. _ .......... 116-118 

D~ar Creek limestone .. .. . . . . . . . .. .. . .. .. .. . .. .. .. .. . .. .. .. 458, 464-465 

Dease River, geology on .................... 219-229,500,542-543,796,836 

Decker Ferry formation .......... ___ ........................... 238,241 

Decorah shale ...... _ .. , ...... _ ..................... _ · 180 

Deep kill shale ............... __ .................... __ . . . . . ... . . . .. 184 

Deep River formation . .. .. .. .. .. .. .. .. .. .. .. .. .. _ .. __ .... .. . 834 

Delaware (J-18), authorities on ........... :. __ ............ 57 

geology of. ........................... 64, 65,610-611,612-613,746-749 

publications on .............................. _· 33,34,35,36,47 

See also Atlantic coast. 

Delaware limestone................................... 242,315-317 

Page. 

Double Mouutain formation..................................... ·475 

Douglas formation ............................... _ 458,833-834 

Douglass, Earl, cited.......... . . . . . . . . . . . . . . . . . . . . . . . . 775 

publications by, list oL .... _ .. ...... .. .. . 848 

Dove limestone............................... .. .. . . . . . .. .. 168 

Dowling, D. B., acknowledgments to ....................... 37-38,60,61 

cited ......................... :...... . .. ·. 217~219, 2fl3, 335-336,574 

publications by, list oL ............... ___ .... ... .. 848 

Doyle shale................................. 465 

Drake, N. F., acknowledgments to. _ ...... ______ 38. li7, S9 

cited ................. __ . __ . ___ . . . . . ________ ..... _ _ _ 458, 506-507 

publication by .. .. .. .. .. .. .. .. .. __ . _....... 848 

Dresbach sandstone ........................ ,_ 118 

Dresser, J. A., acknowledgments to........ 38,60 

Drum limestone ............ :.. .. .. .. .. .. .. .. .. . __ .. __ .. ____ .. 4.>8, 4H4 . 

Dry Creek shale..................................... . ...... 127,128 

Duck Creek formation ......... __ ..................... C04 

Dudley shale . . . . .. .. . . .. . . . .. . . . .. .. . . .. .. . .. . . . . . . .. . . . . . 458 

Dumble, E. T., acknowledgments to ................ __ .... _ ... 38,58,59 

cited ................................... 593,649, 725, 726,727,730, 804 

publications by, list of. ............................. : .. _____ . 848 

Dumble, E. 'l'., and others, puhlication by....................... 848 

Duucan, P. :IlL, cited ........... __ ................................ 643 

Dundee limestone .................... : ..................... 313-314,317 

Dunkard group ................. _ ....................... 12,432, 492,494 

Duunegun sandstone .......... .': .... ::· ......................... G99, 700 

Duplin marl. ............... ~ ... _- ......... · .. , . .. . . . . .. . 7 48, 7 49, 806-808 

Dutton, C. E., acknowledgments fo.: ...................... 38,56,58,59 

cite<!. .......................................... 361-363,513,556-557 

publications by............... :. _._. -~- .• 7 ..... 484,662,848 

Dyes tone formation. See Clinton formation. 

_ Dela_war~oU1ltain formation ......... : .......... ,.. 75,35S--3.>9,474: 

Delhi formation ....... : ........ : ...... : .. : .. ~-~-:~ .. :-:.-.~. 364 --E;-

Del Rio clay................................ . . __ ........ __ .. 590,604 Eagle Ford formation .......................................... 649,650 

Denis, Theodore, acknowledgments to ............ ___ ............. 37, GO Eag!eformation ......................................... 11,637, C85-G90 

Denison formation ..... __ ................... _ .... ___ 650 Eagle Pass formation .......................................... 648,649 

·Dennis limestone ................................... ___ ........ 458,464 Eakin, H. M., acknowledgments to .............................. 38,61 

Denton formation ... , ........... :............................... f>04 · Eakin, H. :IlL, and Smith, P. s., cited............................ 395 

Denver Basin, geology of ............ __ ._. . ......... _ .. 10,66.5-G57 publication by ............... _· __ ........................... ·.. i60 

Dem·er formation ................................... 10, 706, 761-762, 7ti9 Earlier Tertiary (Eocene and Oligocene), content of. ............ 10,706 

De Hance, C.· E., and Fell den, H. W ., publication by............ 849 distribution of.. ...................... : .................. 10,706-708 

D~ Smet formation ................................ , .. .. .. .. .... .. 777 · details of. .............................................. 708-793 

Des Moines group .................... ,_ .................... 457,46.5-466 map showing............................................. 707 

Detroit River series .. ~ .................................... _ .... 246-248 representation of, on map ............................. _ ..... 10,706 

Denssen, Alexander, acknowledgments to ............... __ ._. 37,59, 723 Earlier pre-Cambrian, content of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 

cited __ .... .. . .. . .. . .. . . .. .. .. .. . . . .. . . . . . . . 725, 727, 729-73i, 804, 805 distribution of..... . . . . . . . . . . .. . . . .. . . . . . . . . . .. . . . .. .. .. . .. . .. 14, 62 

Devonian system, content of. .......... __ .......... __ ........ 12, 17,269 representation of, on map ......... --.- ...... :. .. .. .. .. .. . . . .. 14 

distribution oL .......... _ ...... __ . _ ..... _. _ :. ____ . _ ........ 12,269 Earliest Tertiary or latest Cretaceous, content of.................. 10 

details of.. ... _ ...... _ ........ __ .... __ ._· .... __ .......... 271-341 · . distribution oL............ · ...................... 10,20 

map showing ........ _ .......... __ .... __ .... ___ ........... 270 representation of, on map..... . . . .. . . . . . .. .. .... .. .. .. . . . . . 10 

representation of, on map .. _ ................. _ .... __ ........ 12,269 Earlton limestone ............... ·................................. 458 

Dewey limestone ...... _ .......... _ ............ ___ .... _........... 464 Eastern Interior coal region, authorities on ... _: ..... ,............. 466 

De Wolf, F. W., publication by............... . . . . . . . . . . . . 847 geology of. ..... ---- .... -.. : .. - -----.- .. -... ------ ... 425,46tl-4fl8 

D·iamond Peak quartzite . .. . . .. . .. .. .. . . .. .. . . .. .. .. . . .. . . . .. . . . 3(\5 Eastman, C. R., cited.-- ....... -- ... --.--- ...... ,--.----- ....... : S15 

Dighton group ... ____ .. __ ........................ _ 469 publication by............................................... 848 

Diller,J. S.,aclmowledgmcn.tsto................ . ....... 37,57,95 Eckel, E. C., and llayes,C. W.,cited ............................ 87-88 

cited .......... __ .... __ .. _ ......... __ ......... _._ .. __ ._ 289-2ll0,349- publication hy.... ... .. .... . ... .. . . .. .. . . . . . .. . .. . .. .. .. . .. .. 851 

350, 373, 376, 519-521, 561-563, 617-GlS, 670, 7fl4, 771-772, 825 Eckel, E. C., and-others, publication by ................. · __ ....... 843 

publications by ...... __ ..... __ .................. __ 376,820,847 Economy formation.............................................. 172 

Diller, J. s., and Kay, G. F., puhlication by ............... __ .... 847 Economy in printing, restrictions of. ............................. 23,30 

Diller, J. s., and Schucbert, C., puhlication by .............. ".... 847 Ecphom bed ............................ --....................... 809 

Diller, J. s., and Stanton, T. W., cited............... G15,6fl7,670 · Eden shale ....................... : ............................ 165,172 

puhlicatioD by ............... ___ . ___ ........... _ .... _ 847 Edisto marL..................................................... 807 

D'lnvilliers, E. V., publications by ................. __ .......... 433,848 · Edgemont limestone .. ------- ........... : ................. · ... 16,20,194 

Dip of strata, innuence·of, on cartographic representation......... 8 Edmtmton formation ........................ 10, 20,696,697, iOG, 781-782 

. Dismal formation ................................ ____ .......... ·.. 449 Edwards limestone .................................... 596,598,603,648 

District of Columbia. authorities on .... ____ ........ _ ....... __ .... 5'' Effusive rocks (Tertiary and later), distribution of................ 16 

publications on .......... _ _ ............ ___ ..... 36,43,47,51 map showing................................................. 19 

Ditney formation ...................................... _ 467-46~ Elbert formation ........................ :........................ 284 

Dixon clay ................. __ ............. __ ...... ___ ..... ____ .. 235 Elbrook formation ............................................. 109-110 

Dobbs, W. S., acknowledgments to........ .. ........ · 37, flO Eldon formation ................................ : ................ ' 154 

Dockum formation ................................... ·. 476,478,506-507 Eldridge, G. B., acknowledgments to ...................... 38,57,59,61 

Dog Creek formation .............................. _ ............ 487,488 cited ................................... 369,491,558,761-762,786-787 

Dollfuss, A., and Mont-Serrat, E. de, eited........................ 519 publications by ........................................ 665,673,848 

publication by............................................... 848 Eldridge, G. H., and others, publication by ................. · __ ... 849 

Dolores formation .......... __ ._ .... 481-482,492,511-513,518,558,560-561 Elgin sandstone .................................. ,............... 458 

Dome formation ....... ,......................................... 107 Elk Lick coaL................................................... 436 

·Dothan formation............................................... 618 · Ellenberger limestone ........................................... 79-80 

Dotson sandstone ....................................... · ....... 449-450 · Ellensburg formation .................. :.. .. .. .. .. .. .. .. .. .. . .. .. 826 
876 INDEX. 

Page. 

Ellesmere Land, authorities on ................. 155,266,268,341,400,839 

geology of .......................... 15.5, 225,266-268,341,399-400.839 

See also Arctic coast of Canada. 

Ellis formation ................................ 530,534,571-572,621,623 

Ells, IL W.,acknowledgmentsto ...... . ....... 38-39,60,130 

cited........... . ... _ ...... _ ........ _ ..... 132-134,192,197-

204, 209,250, 254, 32.1, 326-327,334, 383, 384,423,498-499, 834 

publications by ............. _ .................. 250,254,541,628,848 

Ells, R. W., and Bailey, L. W., cited..... .. .. .. .. .. .. .. . 384 

publication by.... .. . 848 

Ells, R. '\V., and others, publication by..... .. .. .. .. .. . 841 

Ellsworth schist ...................... _ _ 134 

Elmdale formation .................... . 

El Paso limestone ......................... . 

El Paso quadrangle, geology of. .. . 

Elvins formation ........ . 

Em bar formation ............ . 

......... 458,465 

. . 7.1-76,158 

75-77,158,596-598 

104 

495 ! 

Emerson, R. K ., acknowledgments to ..................... 39,57, .18,59 

cited. . . .. . . . . . . . . . . .. . . . . . . . . . .. .. . .. . . .. .. . .. . 350, .132 ! 

publications by, list of...... . . .. .. .. . . . .. . . . . . . . . 848 

Emerson, B. K., and Perry, J. H .. cited ........................ 470-472 

publication by .. .. .. .. . . .. . .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 857 

Emmons, S. F., acknowledgments to......... .. ..... 39,.18,59 

cited........................ . ............................. 369,759 

publications by, list of............................. 848 

Emmons, S. F., and Merrill, G. P.,cited..... 647 

publication lly........................ .. 849 

Emmons, S. F., and others. publication by........... 849 

Emmons, W. H., acknowledgments to..... 39,57 

cited.............................. 236,491,560 

publication by.. .. .. .. . . . . .. . .. .. .. . . . .. .. . . . . 849 

Emmons, W. H., and Woolsey, L. H., cited..... 512 

Emory sandstone....................................... 452 

Empire formation .. .. .. .. .. .. .. .. . .. . .. . .. . .. .. . . ....... 82-5-826 

Emporia limestone ............................................. 4.58, 465 

Endicott Range. geology of.. ........................... 266,269,340,399 

Endicott Range, Anaktuvuk and Colville River tasins, authorities on .. _ .. __ .......................... -....... - 61 

puhlications on........................................ .50, 72,155 

Enfield shale . . . . .. .. . .. . . . . .. . .. . .. . .. .. . .. . .. . .. .. .. . . . .. . .. . .. 304 

Englewood formation ..................................... _ .... 372-373 

Englishtown sand . .. . . . . . .. . . . . .. . .. . .. . . . . . . . . .. . . . . . 609 

Enid formation . . .. .. . . . .. . . . . . . . . .. . . .. . . . . 478, 487-488,490 

Enochkin formation. See Tuxedni sandstone. 

Eocene. See Marine Eocene; Continental Eocene; Earlier Tertiary. 

Erian group................................. . . .. .. . . . .. . . 297,302 

Erie formation . .. . . .. . .. . . . . .. . . . . .. . . . . . . .. .. .. .. . 421,457,458 

Erwin quart1ite .. .. .. .. .. .. .. 97 

Escabrosalimestone . . . . . . . ............. 357-358 

Escamela limestone........... . .......... 587-588 

Escondido beds. . . .. . .. . .. . . . . . .. .. . . . . .. . 649 

Eskridge shale . .. . .. .. .. .. . . . . . . . . .. . .. 4.58, 465 

Esmeralda formation.................................... 750 

Esopus grit............... . . . . . . .. . . . . . . .. .. .. . .. . 295,297,300 

Etchegoin formation .. .. . .. . . . . . . . .. . . . . . . . . . .. . .... . . . ..... 817,818 

Etcheminian group ................................... 137-139,145-147 

Eureka quartzite .. . .. .. . . .. .. . . . . . .. . . . . . .. . .. . .. .. . . 236,411 

Eureka shale..................................................... 458 

Europe, color scheme for.. . . . . . ................ 24-25 

Eutaw formation .............................. 606,612,614,653,654-660 

Evanston formation . .. .. . .. .. . . . . .. . .. . .. . . . . .. . . . . . 676-677,765 

Everett schist................... . . . . . . . . .. .. .. .. . . . . . . .. .. . . 194 

E xter sandstone ................................................ . 608 

F. 

Fairbanks, H. W., acknowledgments to.. . .............. 39,57 

cited.................. .. .. .. .. .. .. .. .. 616,668 

publication by..... 849 

Fairfax formation . . . . . . . . . . . . 443 

Fairhaven earth ................. .. 

Fairmont formation .................... .. 

Fainriew formation .. _____ . . . . . . . . . . . . . . . . . ................ . 

Fall Creek conglomerate ................ _ ... .. 

Falmouth formation ........................................ . 

Faribault, E. R., acknowledgments to ............ . 

Farnham formation .................................... . 

746,747 

172 

154,172 

304 

719 

39-40,60 

197 

Fayette formation ............... _ .............................. . 730 

Page. 

Fayetteville formation ..................................... 411,412,458 

Feilden, H. W., and De Rance, C. E., publication by............ 849 

Felix, J., and Lenk, H., cited .............................. 549,551,797 

publication by............. . . . . .. . .. .. . 849 

Fenneman, N. M., acknowledgments to ....................... 40,57,58 

cited.: ......................................... 370,516-517,665-667 

publication by . . . . . .. . .. . .. .. .. . . . . .. . .. .. .. .. . .. .. .. . .. .. .. 849 

Fenneman, N. M., and Gale, H. S., cited ....................... 678-679 

publication by............ . . . .. . . . .. . .. . .. .. . . .. . . . .. . .. .. . 849 

Ferguson gypsum ........ _ ..... _ .. . .. . . . . .. . . . . .. .. .. . . . .. . .. . 487-488 

Fernandez de Castro, Manuel, acknowledgments to .............. 40,56 

Fernando formation ........................ _ .................. 814,818 

Fernie shale ...................... __ .. . ............... 574.624 

Fernvale formation ................ . 168 

Fickett series .................................................. 340,399 

Finlay formatiOI .................. _ ...... __ ... _................. 598 

Finlay River region, B. C'., geology of.. ................ 225,263,708,785 

Fischer, Paul, publication by ............... _ ...... ___ ........... 849 

work of......... .. .. .. .. .. .. .. .. .. .. .. . -542 

Fisher, C. A., acknowledgments to ......................... 40,57,58,59 

cited ........................... 495,530,572, 621-G23, (i84, 695,757-758 

publications by, list of....................................... 849 

Fish pot limestone . . .. . . . . .. . . .. .. . . .. .. . . . . . . . .. . . . .. .. .. .. .. .. . 438 

Flaming Gorge formation .......................... 516,558,560,566-567 

Flathead formation ............................................ 127-130 

Flat Rock dolomite ........................................... 247-248 

Fleming clay . . .. . . . .. . . .. . . . . . . . .. . .. . .. _. . 724, 728, 730-731, 804, 805 

Fletcher, Hugh, acknowledgments to ........................ 40, 60,252 

cited................................. 231,329,331,384-385,497,536 

publications by, list of.............. . .. . . . .. .. .. . .. .. .. . .. . 849 

Flint Creek formation .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 834 

Florena shale . .. .. . .. .. . . .. . . . .. .. . . .. .. .. .. .. .. .. . . . .. .. .. .. .. .. 465 

Florence flint .. .. . . .. .. . .. . .. . .. . .. . . . . . .. .. .. . . . .. .. . .. .. .. .. .. . 465 

Florida (G-H 16-17), authorities on.............................. 57 

publications on ..................................... 35,47,50,51,54 

See also Atlantic coast; Gulf coast. 

Floridian series.................................................. 798 

Florissant lake beds .. .. .. .. .. .. .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 759 

Flowerpot formation .. .. . . .. .. . . . . .. .. . . .. .. .. . . . . . .. . . .. .. .. .. . 488 

Floyd shale ................................................ 403-405,418 

Foerste, A. F., acknowledgments to .............................. 40,59 

cited ................................... 116,167,232-235,275-277,740 

publications by, list of...................................... 849 

Foerste, A. F., and Hopkins, T. C., cited ........ ~ .............. 318-319 

publication by . . .. .. . . . . .. . .. . .. .. .. . . . . .. .. . .. . . .. . . . . .. . . . 852 

Foerste, A. F., and Morse, W. C., cited ........................ 415-417 

publication by. .. .. .. .. . . .. . .. . . . . . . . . . . . . .. .. . . .. . . . . .. . . . . . 856 

Foerste, A. F., and others, cited.................................. 116 

publication by......................................... 859 

Fontaine, W. M., cited................................... 565 

publication by .. .. .. . . . . .. .. .. . .. . . . . .. . . . . . . . .. . . . .. .. . 849 

Fontaine, W. M., and White, L C., cited......................... 493 

publication by............................................... 849 

Forbes limestone .. . . .. .. .. .. .. .. .. . .. . .. . .. . . .. . .. .. .. . .. . . .. . .. 458 

Ford, S. W., cited ............................................... . 

publication by ............................................. .. 

206 

849 

Foreman formation . . .. . . . . .. . .. . .. . . . . .. . .. . .. . .. .. . . . .. .. 561, 564-565 

Fork Mountain slate ........................................... 160, 164 

Fort Cassin formation............................................ 206 

Fort Hayes limestone .. .. .. .. . .. .. .. .. .. .. .. .. .. . .. .. .. .. .. .. .. . 672 

Fort Logan formation ...................................... 775,833--834 

Fort Payne chert .............................. _ 403-407,415,418 

Fort Pierre formation ....... _.................................... 648 

Fort Riley limestone ............................ _ ........ 465,479 

Fort St. John shale............................. .. ...... 699-700 

Fort Scott limestone ....................................... 457,458,463 

Fort Smith formation.................................... 458 

Fort Union formation............................... .. ...... 10,681, 

685-688,706,756,761-763,766,769,774-775,770-778 

Fort Worth formation........................................... 604 

Fortyrnile group................................................. 266 

Fossils, citations of.. ........................................... _. 5 

Fountain formation.. . . . . . . . . . . . . . . . . . . . . 369-370, 373, 492, 516-517 

Fowkes formation .. _ ...................................... 676-677,765 

Fox Hills formation.. 11,637,648,667,673,685,691,693,695-696,699 

Fox Land, geology of. ..................... _ ................... 221-222 

Franciscan formation ................ 11,549,554-555,618,753,815,816,818 

Frankfort group---------------------------· ............... 168,184,191 
INDEX. 877 

Page. 

Franklin, authorities on ......•........ --------------.----..... 60 

Franks conglomerate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 458 

Fraser River, geology of..._... . ... _ ... _.... 835 

Fredericksburg group ................... 11,579,588,594-598, 601...(i()3, 604 

Fredonia limestone .. .. ... .. .. .. .. .. . .. .. .. . .. .. . . . .. _ ... 409,413 

Freeman, H. C., publication by • . . . . . . . . . . . . 849 

Freeport limestone, etc................................. . . . . 435 

Fremont limestone................................. 169,367 

Frobisher Bay, geology of._. . .... 222-224 

Frog Mountain sandstone ...................................... 288,405 

Frontenac axis, position of. . _ . 196 

Frontier formation................................ 676,680-681 

Fuller, M. L., acknowledgments to.. 40,56,57,58,59 

Fuller, M. L., and Ashley, G. H., cited ........ _...... .. . 467-468 

publication by ............ _... 849 

Fuller, M. L., and Clapp, F. G., publication by............ 849 

Fuller, M. L., and others, publication by...... 851 

Fulton formation .. .. .. .. . .. .. .. .. .. .. .. .. .. .. .. . .. .. _......... 172 

Fundy, Bay of, geology of. ... _ ... :. . . . . ... _ . . 535-536 

Furnace Creek formation ....................................... 750-751 

Fuson formation .............................. ___ ... 

Fusselman limestone ...... _ ..... . 

G. 

.... :- 672, 685, 691 

.. -...... --- 75,228 

Gabb, W. M.,cited ................ 340-347,519,628,642-648,752,801-803 

publications by, list of. ...... _ ... _ ... _....................... 849 

Gale, H. S., acknowledgments to .............................. 40, 57,59 

cited ................ _ .......... _ ... 382,557,566-567,673-674,759-760 

publications by, list of....................................... 849 

Gale, H. s., and Fenneman, N. M., cited ...................... 678-679 

publication by............................... . . . . . . . 849 

Gale, H. S., and Richards, R. W., publication by................ 849 

Gale, H. s., and Wegemann, C. H., publications by ............ 777,850 

Galena dolomite ................................... 171,176,180,182,195 

Galesburg shale ................................................ 458,464 

Galice formation................ .. .. . . .. .. .. .. .. .. .. .. .. .. . .. .. .. 618 

Galisteo sandstone...... . .. . .. . . .. . .. .. . .. . . .. .. . .. .. .. .. .. .. .. .. 662 

Gallatin formation .. . . . .. .. .. .. .. .. . . . . . 124,127,145,321 

Gane,H. S.,cited .......................................... 483,513,560 

Garde, Victor, acknowledgments to .............................. 40,61 

Gardeau formation............................................... 307 

Gardner, Miss J. A., acknowledgments to ...................... 40,5S,59 

Gardner, J. H., acknowledgments to............................ 40,58 

cited ................................................... 661-{;62,757 

publication by ............................................. 40,8:o 

Garnett limestone . . .. .. .. .. . .. .. .. .. .. .. . . .. .. . .. .. .. .. . .. .. .. .. . 458 

Garrison formation . .. .. .. . . . .. .. .. . . .. .. .. . . . . . .. .. . . . . . . . .. .. . . 458 

Gasconade limestone.. .. .. . .. .. .. . .. . .. .. .. . . .. . . . . .. .. . .. . . .. .. . 104 

Gaspe limestone and sandstone ........ 148-149,254-255,325,334-335,424 

Gaspe Peninsula, authorities on ............ 148,208,209,252,269,334-335 

geology of... . . . 148-149, 151, 208-209,225, 254-256, 325, 423-424, 498-499 

Gatun formation.................................................. 713 

Gault formation................................................. 582 

Geiger, H. R., acknowledgments to .............................. 40,59 

Genesee shale ...................................... 294,297,304,305,307 

Geneva limestone ..................... ·. . . .. .. . .. . . . .. . . . . .. . . . . . . 317 

Geologic divisions, distribution of......... . . . . . . .. .. .. . . .. . . . . 9-16 

ignorance concerning, effect of, in mapping................... 8 

representation of, on map ................................... 7-9,16 

conferences concerning . . . .. . .. .. .. .. .. .. .. .. .. .. . .. .. . 16 

difficulties of.. ....................................... 7-9,10-20 

unequal development of, in different regions.................. 7-8 

Geologic map, explanation of..................................... 5 

George, R. D., acknowledgments to............................. 41,57 

Georgetown limestone . .. . .. . . .. .. .. . .. .. . . .. .. . .. . . .. .. . . .. . .. . . 604 

Georgia (H-I 10-17), authorities on ............. 57, 84, 87, 88,164,605,654 

geology of.. ................. 9, 11, 64, 65, 70, 72,84-88,156,164-165,225, 

230-232, 238, 269, 274, 288,452-455, 579, 605-{;06, 637,654-{;60 

publications on ......................... 33, 42, 43, 44, 46, 49, 52, 54,56 

See also Atlantic coast; Appalachian Mountains. 

Georgian series ....................................... 13,72,108-112,145 

Gering formation .............................................. 821,830 

Gerona marble......... . .. .. .. . .. .. . .. .. .. .. .. .. . .. . .. .. .. .. .. . .. 349 

Gibson, A. M.,cited ............................................ 454,455 

publication by............................................... 850 

Gidley,J. W.,cited.............................................. 757 

Gilbert, G. K., acknowledgments to ....................... 41, 57, 58,59 

cited ............................................... 284,360-367,485 

publication by............................................... 850 

Giles formation ................................................ 231,287 

Page. 

Gilmore, C. W., cited......................................... 622 

Girty, G. H., acknowledgments to ................................ 20,41 

cited .................. 283,320,357-360,367-372,376,379,381,382,380-

387, 392-398, 400, 414, 421, 459-460, 479, 48~1~7. 494,495,530 

publications by . . .. . . .. . .. .. .. . . . . . . . ... o15, 478,479,850 

Girty, G. H., and others, publications by ...................... 840,850 

Glade limestone . .. . . .. .. . . .. .. .. . .. . . . . . . . . .. .. .. . . . 168 

Gladeville sandstone............. . . . . . . .. .. .. 450 

Glance conglomerate. . .. .. . . .. . . . .. ................ .. 

Glass Mountain formation ............................ . 

592 

487 

Glenn, L. C., acknowledgments to... . . . . . . .. .. . . 41,57,59 

cited................. 732-733,734,735 

publications by................................. . ... 653,732,850 

Glenn, L. C., and Ashley, G. H., cited.... .. .. .... .. .. .. 450 

publication by.... .. .. .. .. .. .. . 841 

Glen Rose formation ........................................... 598,602 

Globe limestone . .. . . .. .. . . . . . .. .. .. . .. . . .. . . .. .. . . . . . . . . . .. . . . . . . 357 

Goldman, M. I., acknowledgments to............................ 41,57 

Goldthwait, J. W., acknowledgments to ......................... 41,59 

Goodland limestone.......... . . .. . .. .. . . . . .... 604,605 

Goose Creek marl. . .. .. . . .. .. .. .. . . .. . . .. .. .. . . 807 

Gorby, S. S., acknowledgments lo............... 41,57 

Gordon, C. H., acknowledgments to............. .. 41,58,59, 723 

cited................ . . . . . . .. . . . . . . . . . . . . . . 362,478-480 

publication by . .. .. .. .. .. .. .. .. .. . .. .. .. .. .. . 850 

Gordon, C. H., and Graton, L. C., cited........ 158, 159,228,273 

publication by .. .. .. . . .. .. .. .. .. .. .. .. 850 

Gordon, C. H., and others, publications by ..... 850,854 

Gosport sand .. .. .. .. .. .. .. . .. . .. .. .. .. .. .. .. . .. .... 735-736 

Gould, C. N., acknowledgments to.... . ... 41.58,59 

cited.................. 460-465 .. 476 .. 478,487-490 

publications by................ .. .... 479,859 

Gould, C. N., and others, publication by_...... 850 

Grabau, A. W., acknowledgments to. .. ... 20,41,58 

cited ....................................... 194,237-238,245,246,304 

publications by................ 124, 184_, 238,302,314, 850 

Grabau, A. W., and Sherzer, W. H., cited....... . . . . . . . . . . . . . . 249 

publication by .. .. . .. .. .. . .. .. .. .. .. .. .. .. .. 850 

Grabau, A. W., and Shimer. H. W., cited.......... 293 

publication by. . . .. .. . .. .. . .. .. . .. . .. .. . . . . .. .. .. . .. . .. . .. .. . 860 

Grady coal. . . .. .. .. . . . . .. . . . .. . .. . . . . . . . . . 458 

Graham, R. P. D., acknowledgments to. .. .. .. .. .. .. . 41,60 

Graham Island, geology of...... . ...................... 796,834 

Grainger shale ................................................. 287-288 

Granby tuff . . . . . . . . . . . . . . . . . . 532 

Grand Gulf sandstone . . . . . .. ............................. 729,744 

Grand Mesa, Colo., geology of. . ..... 706,759-760 

Grand Rapids group ..... _ ............................. 420,423,699-700 

Grand Tower limestone .. .. .. .. .. .. .. .. .. .. .. .. .. .. . . .. .. .. .. .. . 278 

Graneros shale .. .. .. • .. . .. .. .. . .. . .. .. . .. .. 663, 672, 685, 691 

Grant, U. B., acknowledgments to ............................ 41,57,61 

Grant, U.S., and Burchard, E. F., cited... .. ... 180-183 

publication by......................................... s5o 

Graptolite shale. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . .. . . . 328-329 

Grassy Creek shale .. .. .. .. .. . • .. .. • .. . .. . .. .. .. .. . .. .. .. . 413 

Graton, L. C., and Gordon, C. H., cited... .. .. 158,159,228,273 

Graton, L. C., and others, publication by......................... 854 

Gravina series.............................. .. .. .. .. .. .. .. .. 542 

Grayson formation ............................................. 604,650 

Great Basin, authorities on... . ..... 98--102,282-284,750 

geology of.. 9, 72,98-102, 156, 168-169,269,282-284,706,750-751,820-821 

Great Plains, geology of............. . . . .. . . . . . . . . . . .. . . . .. . . . .. 11, 

637' 761-764,769-770,781-782,794, 813-814,821-823 

Great Smoky conglomerate. • . .. . .. . . . .. .. .. . .. .. .. . .. . .. . .. .. . .. . 98 

Green Bay region, Mich., geology of. . . 195 

Greenbrier limestone . .. .. .. .. .. . .. .. .. .. .. . .. .. .. .. .. .. .. .. .. 408, 418 

Greene formation. . .. . . . . . .. . . . . . . .. .. .. . .. .. .. .. .. .. . .. .. . .. . 493 

Greenfield dolomite .. . .. .. .. .. . .. ............................ 247, 248 

Greenhorn formation .................................. 662,672,685,691 

Greenland, authorities on.... . ........ 61,224,341,546,547,577,839 

geology of......... . ...................... 10, 16, 62, 65, 72,155, 

156,224,269,341,500,546-548,549,577-578,639,704,705-796,839 

publications on ................ , ..................... 40-46, 48, 52,53 

Green Pond conglomerate ..................................... 240-241 

Green River formation .......................... 10,676,706,758--760,765 

Greenwood shale . . . . .. .. .. . . . . . . . . . .. .. .. .. .. .. .. .. .. .. .. . .. .. • • 458 

Greer formation ....................................... 478, 487, 48~89 

Gregory, H. E., acknowledgments to .......................... 40,56,57 

cited......................................................... 194 

publication by............................................... 850 
878 INDEX. 

Page. 

Gregory, H. E., and Williams, II. S., cited ....... _ 328-329 

publications by._ .. _ .. _______ _ _ _ _ _ _ _ _ _ _ _ _ 254, R65 

Grenville series .... _ .............................. _ ... _._ .. 137-138, 197 

See also Hastings and Grenville series. 

Greytock schist._._ ................................. _ .. _. __ ._ .. 193,194 

Grinnell Land, authorities on ........... _._ ... _ ......... _ ..... _.. 547 

geology of. ...... __ ...... _ ........... __ ..... _._. 355,400,500,547-548 

Griswold, L. S., acknowledgments to ............ __ ..... _ ..... _._ 41,56 

Grizzly formation ...... _ ........... _ .... __ .... __ .... _._ .. _ .... 175,242 

Guadalupe group._. __ ... _._ ..... _ ..... __ ......... _ ..... 75,359-360,363 

Guaduas formation ........ _ ................................ 10, 706,708 

Guatemala (D-E 15-16), authorities OIL 425,427,503,504,549,585-587,721 

geology of......................... .. _................ .. .. . 12, 64, 

357,401,425-427,500, 503-50-!,549,579,585-587, 590,706, 721-722 

See also Central .America. 

Guelph dolomite .... _ .......... _ .. _ .. _ .. _ ........ _ ..... 237,238,245,255 

Guernsey formation. __ ..... _ ...... _ .. __ .......... _ ..... _ ... _. _.. 373 

Guerrero (E 14), geology of.. __ ._._. __ ._ .. _._ .... _ ...... _._ .. _.... 589 

Gubik sand ....... _ .. .. .. _ ...... _ .... _ . _ ......... _ . 792 

Gulf coast, authorities on ................ -.......... _ .... _ .. 21,654,806 

geology of •. _._. __ .... _. 9, 10, 11,637, 654-660,706, 731-745,794,806--813 

See also particular States. 

Gulf series .......... __ ...... _ .... _. __ ... _ ..... _._ .. _._ ..... _ 11,637,650 

Gunnison group ..... _ ............. _ ... __ .......... 513,557-558,5G7,(i71 

Gurley, R. R., publications by .. _._.____ _ ... _ .. _. _ .......... 206,850 

Guyeformation ...................... -. _ ... _ ...... -. _ .. -.. ... .... 826 

Gwillim, J. C., acknowledgments to.- .. _ .. _ ... _._._ .. _ .... _ ...... 41,60 

cited ............. _ ...... _._ .... _ .... __ ._ ... _ .. _._............ 576 

publication by ....... _._ .. _ .. _ ... _ ......... _ .. _._._ .... _-.... 850 

Gwinn coal. .... _ ................... _ ... _.. .. .. .. .. . .. . .. . .. . .. .. 454 

H. 

Hague, Arnold, acknowledgments to ..... _ ....... _ ....... _ .... 41,58,59 

cited ............ _ .. _ .... _ ..... __ .... _ ....... _ .. 168,236,364--365,387 

publications by ........ _ ........................... _ ... _ ... 550,850 

Hague, A., and others, publications by, list of. ............ _ 850 

Hale formation ..... _ ..................................... _...... 458 

Hall, C. W., acknowledgments to ........ _ ..... _ ....... -...... 41,58,59 

cited ........ _ ............. _.-.- .... _ .. -................ _-.--. ~8'.l 

Hall, C. W., and Sardeson, F. vV., publications by._ ........ 41,169,851 

Hall, C. W., and others, publication by .•....... _ ........... -.. _. 851 

Hall, J., cited .... _._. __ ...... _ ...... _._. __ .......... _._ ... _ 208,297-308 

publications by ........... _._._._ .. _ ........ _ .. _._._ ..... _. 298,851 

Hamburg !ormation. __ .................... _ ....... _ .... _._ 124, 145,005 

Hamilton formation ..• 200,279--280,291-292,294,297,302-304,309-310,317 

Hamlin, Homer, acknowledgments to ... __ ._ .. _. __ ... _ .. _._ ...... 41,57 

Hammer, R. R.I., acknowledgments to ...•.• __ _ __ ... _ 41, til 

Hampshire !ormation .................. _. __ .. __ .... __ ...... _-.- 275, 28ti 

Hampton shale ...... _ .. _ ............ _ ......... _._ ...... _._ 97 

Hance !ormation ......... _ ........................ _ .... _._...... 450 

Hancock limestone ...... _ ........... _ ... _ ............. _ .... _ .. 231,287 

Hanford formation ...................... ,_ ............ _ .. _....... 145 

Harder, E. C., acknowledgments to ....... _ ................... 41,57,59 

Hardgrave sandstone ................................ _ ..... 561--562,571 

Hardin sandstone ..... -.. - _ ........ _ .. . .. .. .. .. .. .. .. .. .. . .. .. .. 277 

Harding sandstone ...... -. _ .......................... _ .. .. .. .. .. lti9 

Hardwood Point shale.-._ -__ ....................... _.......... 422 

Hardyston quartzite ........ -............................. 113,178-179 

Harkness coal. ••... _._- ____ ........... -......... _ ........ _...... 455 

Harlem formation) et(' ....... -.......................... , ...... 436) 450 

Harpers formation ... __ -... _ ................... -....... -... 108, 109, 4S7 

Harris, G. D., acknowledgments to ..... -.. -... _.- ........... _ .... 42,57 

cited ......... _ .... _-._ ...... _ ... _ ............. _ .... 726, 734-735,804 

publications by, list of. ........... -.- ........ -.. -.- 851 

Harris, G. D., and Dall, W. H., publication by ....... __ ......... 846 

Harris, G. D., and Yeatch, A. C., publication by ............ _.... 851 

Harrison formation ................ _ ............. _ .. - ___ . 821-823 

Harrodsburg limestone ...... ____ ...... -.................... __ . 412-413 

Hartford limestone ................................. ----.. -.... -. 458 

Hartley, Edward, acknowledgments to_. __ ._._ .. -_.- __ ..... 42,60 

Hartnagel, C. A., rited... . ............... _ ............. !.... 2-U 

publications by_.... ____ . _____ ..... _ .. _ .. -.. _ ....... 238,8.51 

Hartselle sandstone ................................ 403,405--406,418,458 

Hartshorne coal ancl sandstone .. _ .............................. 458, 462 

Hartville formation ................................. - 373 

Hasmark formation .... ---- ....... --- .... _ .................... --. 130 

Hastings and Grem·illc series ......... --......... -.. --.... - 14, 16, M, 67 

Hatcher, J. B., cited .... -·-------- ________ ............... 822--823 

publication by._ ............. _............................... 851 

Pa,ge, 

Hatcher, J. B., and Stanton, T. \V., publication by.............. 861 

Hatchetigbee formation ................ _......................... 734 

Hattiesburg clay ........ __ _ ____ ................. _..... .... .. 744 

Haughton, Samuel, cited .... _ .. _._ .. _ _ _ .... _. __ ... 264--265,399--400 

publication by.......................... .................... 851 

Haworth, Erasmus, acknowledgments to .... _._ .. _ .. _ ....... _ .. _. 42,57 

cited ...... _ .. ___ .... _ ......... _._ _. _ .... _ .. ___ ..... 456,457,458 

Hawthorne formation ................................. _ .. _ .. _. 741-742 

Haycock, Ernest, acknowledgments to. __ ._ 42,60 

cited .... __ .. ___ ..... _ .. ___ .. _ .. _ ... __ .. _ ... _ .. ___ .. _ ... ___ .. 352 

publication by ............. ___ .. __ ............. _ .. __ 851 

Hayden, I<'. V., acknowledgments to .................... 42,56,57,58,59 

Hayden, F. V., and Meek, F. B., cited...................... 762 

publication by ...... ______ ....... ______ .. _. _ ........ _ .. -. _.. 856 

Hayes, C. W., acknowledgments to ...... -.. _._. __ ....... _. 42,56,59, 70 

cited ...... _ ..•... _ ..... 84--88,90,91,164,232,288,406,418,452,709--711 

publications by .... _ .. _.-_ .... _ ..... _ .. _ .... _ .. _ .... _ .. 173,542,851 

Hayes, C. W., and Eckel, E. C., cited .. _ .. ___ ...... _ .... ___ .. _ .. 87-88 

publication by ........ __ ... _ .. _-.- ........... _ .. ___ .. _ 851 

Hayes, C. W.,and Kennedy, W., publication by .............. __ 851 

Hayes, C. W., and Ulrich, E. O.,cited ............. 168,277-278,401-402 

publication by ...... ____ ........ _ .. _____ .. _ .. _ __ 851 

Haystack gypsum .. _ __ _ .............. _ ................ _.. ... 487 

Hazel slate ..... ___ ............ _ ..... __ ....... ________ .... __ ..... 95 

Hedges shale ...... __ ...... _ ..... _ ..... _ ... _ ................... 418-419 

Heer,O.,cited.... . .................................... 222,400 

Heikes, V. C., acknowledgments to ....... _ ....................... 42,57 

Heilprin,A.,cited ........................................ 721-722,798 

publications by, list of. ...... _ .. _ .. _ .. _ ........... _____ .... 851-852 

Helderberg group ........ _ ....................................... 12, 13, 

17,201,225,245,250,269,274--275,279,282,297,298-300,324--325 

Helena coal. .... _._ ............................ _ .. _. __ ._......... 455 

Hell Creek beds ..... _ ...................................... _ .. 763-764 

Henderson, Junius, cited ... _._ .. _._ ... ____ ._ .. _._ .. _ ........... 369--370 

publication by ......... _- __ .- ...... _ ... ____ .................. 852 

Henrietta formation .... ___ ............................. _ ...... 457,458 

Henrys Fork !ormation ................................. __ ....... 558 

Hermitage formation . . . _ ................... _...... . . . . . . 168 

Hermosa formation ... _ -_ . ___ ....................... _ .. _ .. 371, 558 

Herndon, J. H., and others, publication by ........ ____ ...... ____ 848 

Herrick, C. L., acknowledgments to ..... __ ....... _ .. _ .... _ .. ____ . 42,58 

cited ... -.- .. -.- .. --.--.- .. -...... --- ...................... - 362,415 

Hershey, 0. H., ack--nowledgments to ................ _ ............ 42,57 

publications by ............... -._.- ___ .. _ .. _ ....... _._ .. __ . 820,852 

Hertha limestone ... : .... _ .... -............................ _____ . 458 

Hess, F. L.,acknowledgments to ............................... 42,57 

Hess, F. L.,and Prindle, L. M., cited............................ 703 

publication by ....... _ .. -.. _................................ 857 

Hesse sandstone ............................ _ ................. 92, 95,96 

IIettner, Alfred, acknowledgments to .. ___ _____ . _ .... _ .. _ .. __ . __ 42,56 

cited ... -.. -.-._ .. -... -...... -.. -.... --.- .. -.- ......... -.... 582,708 

publication by .................... __ ........... _ .......... __ 852 

Hickory sandstone ................................. -............ 77-79 

Hidalgo (F 14), geology of. .. -............ -.......... -.......... 590,797 

See also Mexico. 

Higgins, D. F., acknowledgments to ............................. 42,61 

High Falls shales .. . .. .. .. .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 240, 241 

Hignite formation .................................. _ .. _ _ 450 

Hilgard, E. W., cited ....... _ ..... -.. _.-.-_ 654-656,729,730,737-738,812 

publications by, list of. ..... -...... -.- ...................... _ 852 

Bill, B. F., acknowledgments to ...... _ .. -....................... 42,59 

Hill, J. IlL, acknowledgments to ................................. 42,56 

Hill, R. T ., acknowledgments to ...... -.. _- ...... 21, 42, 56, .57, 58, 59,227 

cited .......................... _ ............... ___ ........... 227, 

345--346,348,585,589,001,606,639-642, 65{}---()52, 717-721,799-801 

publications by, list of. ......................... _............ 852 

Hill, R. T., and Vaughan, T. W., publication by................ 852 

Hilliard formation ............................ ____ ...... _.-_. ___ . 676 

Hill Quarry beds .......................................... 165--166,172 

Hills, R. C., acknowledgments to ............. -........ ___ ... __ .. 42,57 

cited .. __ ......... _. __ ._ .... _ ................... 491,662-665,758-759 

publications by, list of. ..... _.-.-._ .... _ .. _.-._ .......... _ .. _ .. 852 

Hillsboro sandstone ......... _ ...................... _ ... -... -.. -. 234 

Hinchman tuff .. .. .. . .. .. . .. .. .. .. .. .. . .. . .. .. .. . .. .. .. .. .. .. . 561, 564 

Hitchcock, C. H., acknowledgments to .................... _ ... 42, 58,59 

cited ..... _ ........ _ .. _ ........ _ .................. -._._ ..... 192,250 

publications by,list of. ................................... _ 852 

Hiwassee slate ................................... __ ...... -. _. 95, 96,98 
INDEX. 879 

Page. 

Hobbs, W. H., cited ..••..•.........•...•..•••••.••.....•...... 194,532 

publications by, list of. •.............•...•.... ,.............. 852 

Hoeing, J. B., acknowledgments to ..••..•....................... 42,57 

Hogs hooter formation . . . . . . . . . . . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . 464 

Holdenville formation ........•............................ 458,463-464 

Holiknuk series . . . . . . . . . . . . . . . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . 633 

Hollick, Arthur, cited .......................................... 502, 702 

publications by, list of....................................... 852 

Holm, G. F., acknowledgments to ............................... 42,61 

Homewood sandstone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434 

Bonakcr limestone ........................................... 93-94, 69 

Honduras (D 16-17), authorities on .................... 345,50Q-503,584 

geology of. •...................... 12, 64,342,345,355, 50Q-503, 579,585 

Ste also Central .\merica. 

Boneyman, D., publications by, list of........................... 852 

Hoosac schist ........................ _ ............. _ . . . . . . . . . . . . . 194 

Bopcwell formation ................. _ ............. _ ....... 386,799,801 

Bopkins, T. C., cited ....... _... . .... _ ... _ ....... _ ........... 467, 730 

publication by ................................ _ 852 

Bopkins, T. C., and Foerste, A. F., cited .......... _ ........... 318-319 

publication by .... _ ............. _ ............. __ . . . . . . . . . . . . 852 

Hopkins, T. C., and Sicbenthal, C. E., publications by ........ 413,852 

Bornerstown marl ..................................... _ . . . . . 609 

Borse Creek coal ........................•...••••••............ 454, 455 

Horsetown formation ........................ 11,615-620,751,753,815,818 

Bosselkus limestone ............................... _ ... 374,519-521,528 

Bovey, E. 0., and Whitfield, R. K., publications by ........... 570,865 

Boward limestone ......... _ ................................... 4.58, 465 

Howe, Ernest, acknowledgments to..................... . .. 43, 56,57 

cited ....................................................... 711.714 

publication by............................. 852 

Howe, E., n.nd Cross, Vtl., publication by. __ . 845 

Howell formation .............. _................. 107 

Howlcy,J. F., acknowledgments to..... . .... 43,('0 

Hudson Bay, region west of, geology of................. 68 

southwest coast of, geology of ...................... 220-221,225,263 

Hudson River group ... __ .......... 172,187,192,193,196,209,217,239,259 

Hudson shale ......................................... wg, 169-171, 189 

Hue, definition of................................................ 22 

Hueco limestone .. _ ... _ ..... _ ........................... 75-76,358,363 

Huene, F. von, cited............................................. 559 

Huerfano formation ................................... _ .. 758-759,766 

Hmnboldt formation............................................ 9 

Huntington, Elloworth, acknowledgments to........... . ... 43,59 

cited......................................................... 507 

publication by.............................................. 852 

Huntington formation .. . .. .. .. . . .. .. .. .. .. . . .. . .. . . . . .. . . . . 415 

Hunton limestone ......................................... 228-230.273 

Huron liJnestone ........... ---------- ... ---- ... __ ...... _ ....... _ 413 

Huronian syBtem ......................................... 137-138,147 

See also Upper Huronian; Middle and Lower Huronian. 

Hutchinson, L. L., and others, publication by.................. 850 

Hyatt, Alpheus, cited ......................... 52Q-521, 528,562-505,571 

publications by ............ : ................................ \55, 852 

Hyatt,A.,andSmiih,J. P.,cited ............................. 527-528 

publication by.............................................. 852 

I. 

Iceland, authorities on ......................................... _. 61 

geology of.................................................... 1G 

publications on ...... __ .. _ ... -.. _ ... -.. _ ........ _ .. 40-4tl, 48, 52, 53 

Idaho (K-M 11-12), authorities on ............... _ ... _ ... _....... 57, 

106,107,350,527,528,529,533,534,685,819, 82Q-824 

geology of. ......................... 12,14, 17, 04, 72, lOfr-107, 322,342, 

3.10, 500.527-5:30,.533-534,639,685-686,794,819, 82Q-821, 824-825 

publications on ........................ 35, 38, 40, 41, 42, 45_. 49, 50, .\4 

See also Rocky Mountains. 

Iddings, J. P., acknowledgments to .... _ ......... _ ........ _ ... 43, 58,59 

Iddings, J.P., and Weed,_W. II., cited.......................... 534 

Ignacio quartzite .............................................. 102-103 

Igneous rocks, representation of. ................ _ ....... _........ 29 

Iliamna-Lake Clark region, authorities on ....... __ ... G1 

publications on ............................................. 43,47 

Illinois (J-K 15-16), authorities on............................... 57, 

169, 170, 176, 180, 183,236, 24:l, 278,279,408,410,411 

geology of. ................................... _ .... 156, 169-171,176, 

18Q-183, 225,236, 243-244, 27G, 278-282, 401, 407-412, 466-468, 655 

publications on ............................... 31, 32, 34, 35, 40, 41,55 

Page. 

Indiana (J-K 16), authorities on .................... 57,171,232,317,318 

geology of. .. _ .......... 156, 171-172,225,232-235,269,317-319,466-468 

publications on .................................... 31, 32, 35, 40,41 

Ingall, E. D., acknowle<lgments to ............................... 43,60 

publication by................... --------··-· 8.52 

Inglefield formation ........................................... 467-468 

Innoko region, authorities on .......... _ ................ _........ 61 

publications on.............................................. 47 

Interior province, geology of ................ 9. 10, 11, 13,455,468. fh'l7, 794 

See al80 Great Plains; Western Interior field; Eastern Interior 

field; particular St"t<-<. 

Intermediate limestone .. _. _ .................. _ .... _ ..... _....... 333 

International Geological Congress, color scheme adopted by ..... . 

Intrusive rocks (post-Cambrian), content of. .................... . 

distribution of ........ _ .. _ ... _ ... _ ........ _ ......... _ ....... . 

map showing.................... . ............. . 

representation of, on map................ . .. __ .... _ .... . 

Intrusive rocks (pre-Cambrian), content of ...... . 

distribution of ....... _ .. _ ......... _ ......................... . 

24 

16 

16 

18 

16,20 

15 

15,65 

representation of, on map ......... _ ...... _ .. _ ........ _._ ..... 15, 20 

lola limestone ................................................. 458,.464 

Iowa (K 14-15), authorities on .. 57, 180,183,242,290,408,410,411,455,465,497 

geology of. ........ _ . . . . ......................... 156, 18Q-183,. 225, 

242-243,269,290,401,407-412,455,458,465-466,474,497,639,682 

publications on ................................. 32, 34. 41, 50, 53,55 

Ireland, William, acknowledgments to ........................... 43,57 

Isle of Pines, geology of. ................................ _ ...... 349,552 

Ithaca group ............................... 293.297,304,305,308-309,312 

Tr.ard limestone.................................................. 169 

J. 

Jacalitosformation ............................................ 817,818 

Jackass Mountain group ....................................... 625-626 

Jackfork sandstone ............................................ 458,459 

Jacksonhurg limestone........................................... 179 

Jackson formation .............. _ ....... 723-724,727-728,731,738-739,748 

Jacksonville formation ......................................... 808-809 

Jaggar, T. A., jr., ac1:nowledgments to ........................ 43,56,59 

cited ......................................... -............ 178 

publication by............................................... 853 

Jalisco (E-F 13), geology of............ --··--··--···-···-· 590 

See also Mexico. 

Jamaica (E 18), authorities on .......................... 639,717,799-801 

geology of. .................. 10,637,639-642,706,717-720,794,799-801 

See also West. Indies. 

James Bay, Ontario, geology of. ............................. __ . 335-336 

Jamesons Land, geology of................................ 547 

JeJierson City limestone......................................... 104 

Jefferson limestone .................................... 2R3-284, 319-323 

Jefferson;-illelimestone ........................................ 317,319 

Jennings formation ............................................ 27-5,286 

Je.:sen, A., acknowledgments to............. . ............ _____ . 43,61 

Jiron formation .. .. . . .. .. . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . .. 582 

Joaquin limestone ................................. --........ 104 

Johannian series._.............. . ....... ----- ... _. .. . 147 

John Day Basin, geology of.. . .... 579,621,639,685,796,820-830 

John Day formation............ ------······· 772,826,830 

Johnson, II. R., acknmYledgments to .. --. . ... __ ..... _ ..... 43,57,60 

Johnson, L. C., cited.... -... -- .. -.... -.......... --... 6.14-657 

Johnson, L. C., and Crider, A. F., cited .. _ ... __ ... _. __ ... _._. __ 737,738 

Johnson, T,. C., and Smith, E.,\., puhlication by ..... ___ ...... __ 8fi0 

Johnson, L. C.,and others, pu:,ucation by.- ..... _---··_._ .... _. 860 

Johnston, J. F. E., ackno\vledgments to ..... _. __ ._ .... _ ...... _ ... 43.60 

Johnston, R. A. A., acknowledgments to ................. ____ .... 43,60 

Johnston, V{.A.,acknowledgmentsto...... --··----···-- 43,60 

Johnstown limestone...... . . . . . . .. . . . . . .. .. 435 

Jones, T. H., pul)lications 11y ___ . __ ... 

Jordan sandstone .... _ ... 

Judith River formation .. 

Juniata formation ... _ ... 

·-··--···· 265,400,8.53 

118 

. ....... 11,637,(i87-690 

--·----·- 23i,239 

Jurassic system, contenL of._ .. ------- .. -- .. ---- .. - 11,549 

distrihntion of .... _ .. . - . - . --- -- -- -. - ... -- -- .. --. -- 11' 17' 549 

details of. .. ---.-- .. -- .. -- ·-- ... -· .. -.. ·---- .. - 549,578 

map showin~~---· _. . ............... ___ ..... __ .. __ . __ . .550 

representation of, on map._ .. _ ... _ .. _ .. _ ........ __ ... ___ . 11, 17,549 

See af.~o Triassic and Jurassic. 

Jurassic and Triassic. See Triassic and Jurassic. 
880 INDEX. 

K. Page. 

Kachemak Bay region, authorities on............ .. . . . . . . . . . . . . . . 61 

publications on, lists oL .... _ ................ _ ................ 47,52 

Kachess rhyolite._. __ ..... _ ............. _ ....... _ ... _........... 774 

Kaibab limestone. _ ... __ ... _. _ ................... ____ ... __ . _ ... _ _ 366 

Kamloops district, geology of .... _ .... __ ... ____ . _ .. _ ... ____ .. _ _ 538--539 

Kanawha formation __ ..... _ ................. _ ..... ____ .. __ 443,446-447 

Kanouse sandstone . _ ... _. _ .. _ .. __ . _ ... ___ ... _ . __ .. ___ ..... ___ . . . 299 

Kansas (J 14-15), authorities on ..... 57,455,486-487,489,606,614,672,813 

geology of.. .. __ .. _ ........... _ ... _ ......... ___ . 12,42-5,455-458,466-

465, 474, 486-487, 489-490, 579,606,614-615, 672-673, 813-814 

publications on _ .. __ ... ______ . ___ .. ___ . _. ____ .... _ .. 33, 36, 42, 49,50 

See also Interior province; Great Plains. 

Kanwaka shale .. __ .·--·--_._ .. ___ .... ____ .. _ .. ___ .. _ 458,464 

Karquinez formation _ ... ___ ... _. _ ... ____ .. _. ___ ... 816 

Karsten, Hermann, acknowledgments to.... _ ...... _ 43,56,581 

cited ........ __ .. __ .. __ ... __ ..... __ . _____ .. ________ . 581-582,708,796 

publication by ..... _. __ .... _. ____ .. _____ .. _____ .. ______ .. __ -- 853 

Kaskaskia formation .. _ .... __ ... __ .... _ .... ___ ... ____ . 408,411-413,458 

Katalla formation __ .... __ ... _ .... _ ..... __ ... _ ... __ ... ___ .. -... - - 789 

Katemcy formation ... _ .. ___ .. ___ _ __ . _ ---- .. _ 124,145 

Katmai Bay, geology of ... _ _ _ _____ . . 70S, 784 

See also Alaska Peninsula. 

Katz, F . .T., acknowledgments to .. _ _ _____ ... _-- 43,61 

Kay, F. H., acknowledgments to ... _______ 43,59 

Kay, G. F., and Diller, J. S., publication by_ ... ___ ..... _ 847 

Keele, Joseph, acknowledgments to ..... ___ . _ .. ____ ... _____ . .. 43, 60, 61 

cited ..... _ .. ___ .. __ . __ . ___ ... __ . _ . ____ .. _ _ _ . . . . 338, 544-545 

publication by. __ ... __ . __ .. _ .. ___ . _____ .. ____ ... ___ --........ 853 

Keewatin series __ .... _ . _ .. _ ..... ___ . _ . _ _ _ _ ___ . ______ ... _ 15, 62,65-66 

Keith, Arthur, acknowledgments to. ____ .. ____ ... ___ ... _ 21, 43, 57, 58,59 

cited ... _ .... __ ... _ ... __ .... _._ .. ____ 76-71,89,93-98,173-174,231,451 

publications by .... _ .. ___ .. ____ ... ___ .. ____ ... ____ .. __ . 173,288,853 

Kemp, I. F., acknowledgments to ... ___ . _______ , ____ ... _____ .--.- 44,58 

Kenai formation .... __ ......... _ .. ___ . __ 10,574,702,706,784---787,792,793 

Kenai Peninsula, authorities on.__ _ .. __ .. _ .......... 61,785 

geology of.._ ... __ .... __ ... ___ _. __ . ___ ... ___ .. 708,785-787 

publications on_ .... ___________ _ ____ .. ___ . _ -- _--- 41,42,48 

See also Alaska, southern. 

Kennedy, William, cited._ ... _ _ ... ______ ... ____ .... --... 730 

publications by, list of. .. __ _ _ ..... __________ -------- 853 

Kennedy, W., and Hayes, C. W.,publication by,________________ 851 

Kennedy, W., and others, publication by__________________ 848 

Kennett formation ___ ... __ ... _ .... _____ ........ __ . ____ .. ____ --. 289,374 

Kentucky (J 16-17), authorities on .... __ .... 57, 165,275,412,413,415-417 

· geology of.. 225,232-234,269,275,401.412-417,418,442-452, 466-4f>9, 655 

publications on ....... ______ .. ___ . 31.35,41,42,48,49,55, 156, 1G5-156 

Keokuk limestone . _ .... __ .... __ ... ___ .. _____ .. 401.403,408,411,413,458 

Kerr, W. C., cited .. ____ ... _____ . __________ .... ______________ 70,508-509 

publication by.___________________________ ------------· 853 

Kessler limestone__ _ _________ . ___ .. _____________ . 458 

Ketona dolomite_ .... _ .. _ .. __ .... _ .... __ .. __ .-._ ------. 164-165 

Keweenawan series ... __ .... ___ ... __ ... __ --._. __ ... __ -... -- 14, 64,68 

Keyes, C. R., acknowledgments to .... _ .. _________ ... _______ .... - 44,58 

cited .... __ .... ___ ..... _ ... ___ ... ___ ... _ 1tl9-170,236,278, 375,457,458 

publications by .... __ ... ____ ... __ .: __ -- ... _ -.. 278,457,853 

Kiamitia formation_ .. _____ ... _._ .... _. ___ ----._ .. _ 604 

Kickapoo lill\estone ..... __ .... _. _ ... _- . _ ..... -.... _ --. -- . 458, 464 

Killebrew, J. B., and Safford, J. M., publication by .... _ 858 

Kimberling shale .... ____ .. _ _ _ .. -- .... - __ -_ -· _ 287-288 

Kimeridge formation ..... ___ .. ___ .... -... -- - -- _ .. -•-. _ --. _ - -. _- . 553-554 

Kinderhook group ..... __ .... ___ ... ____ ..... _ .. 278, 401, 408, 410, 413, 458 

Kindle, E. M., acknowledgments to ..... _-- .. -_ .. __ ........ 20, 44. 58,61 

cited .... _ .... __ .. _. _ ....... ___ ... 1G9, 222,236-2.37,244,262-266,275, 

283-287,317-319,323-324,339-340,349,392-395,397-399,545-546 

publications by._ .......... __ .... _-_ .. ---- .. __ .. 273,294,320,413,853 

Kindle, E. M., and Barnett, \'. H., cited.-- .. - __ .. ___ . __ .. _ .. __ ._ 233 

publication by-._ ........ _--- ..... -- .... -- .. -- ... ----·.--·.-_ 853 

Kindle, E. M., and Brooks, A. II., cited .... __ -.. __ . 395,635-636, 704, 792 

publications by, list of. ... -- .. --- .. ----- .. -- .. -------·-- .. --. 843 

Kindle, E. M., and Williams, H. S., cited ..... __ .. ___ ._ 293 

publication by ...... _ ... ___ .. __ --- .. ------- .... -.. --.-------- 865 

King, Clarence, acknowledgments to __ .. __ -... __ .. ___ . __ ... 44, 57, 58,59 

cited .......... __ _ ___ ... ___ 376-377,510-511,521,556, 675,819-829 

publication by ..... _ ...... ____ ------- ... -- .. _ .... --- .. -...... 851 

Kingfisher formation._ ... __ .... ___ ... -·- ................ -· .. -- 487 

Kingsbury conglomerate __ ._ .... _ ..... _ ..... _ .... _ ......... _..... 777 

Kingston formation ................ _ ............. _ ..... __ .. 295,806-801 

Kintla formation ____ .......................... ____ ... -- .. -...... 539 

Kiowa shale ...................................... _ ......... __ . 614-615 

Page. 

Kirkwood formation ....................................... _._ 746,749 

Kirsopp, J., cited ... ----- ____ ... _ ..... _ .. __ ..... _ .. ____ .. ____ ._ 787 

Kiser gypsum ....... , ........................ _ .............. _... 487 

Kittanning limestone, etc ...................................... 435,458 

Kittatinny limestone ................................... _ .. _ . _ . 113, 179 

Klamath Mountains, authorities on._ .................. 288,289,617-620 

geology of. .......... 12,242,269,288-289,342,349-350,494,579,617-621 

Knapp, G. N.,cited............................................. 823 

Knapp beds ............................. _ .... ___ ... _____ . __ ._ .. _ 297 

Knight, W. C., cited .............. _ ............................ 491,532 

publication by ........... _ ............... _ ........... _ ..... __ 853 

Knight formation ...... _ ................................. _. 676-677,765 

Knobstone formation .......................................... 412,413 

Knopf, Adolph, acknowledgments to .............. _ ............. 44,61 

Knopf, A., and Moffit, F. H., cited .......... _ .. _ .......... 394---395,790 

publication by ..................... _......................... 856 

Knopf, A., and Paige, S., cited ... _ ..... _ ........ _ ........... _.... 788 

publication by............................................... 857 

Knowlton, F. H., aid of.......................................... 20 

cited ...... -· .......... 502,565,617, 618-619,623,633,674,6S6, 702,762-

764, 767, 773, 779, 780, 783-784, 786, 787, 791, 826,831,836,838 

publications by ..................... ______ .. _ ........ _. ____ 764,853 

Knox dolomite ...... -.. -....... 86-87,89-94,96,124,145,164---165,173-174 

Knoxville formation ............................................ 11,17, 

565,615-621,668--669,751,753, 754,815,816,818,824 

Knoydart formation ....................................... 251,336-331 

Kobuk Valley, authorities on ...... _ ............................ 61,791 

geology of ........ -.. -.. _ ............................... 354, 708, 791 

publications on.............................................. 47 

See also Alaska, northwestern. 

Kodiak Island, authorities on. .. .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 61 

geology of .................................................. 708, 784 

publications on .............................................. 33,36 

See also Alaska Peninsula. 

Koipato group ........... _. . .. . .. . .. .. .. .. .. . . . .. .. .. .. . .. .. .. .. 521 

Kolmakof series .. .. . .. .. .. .. . .. . .. . .. . . .. .. . .. . .. .. . .. .. .. .. .. .. 633 

Kootanie series. See Kootenai series. 

Kootenai series ..... -...... _. __ .. __ . 11,579,621-625,630,686,687,693,698 

Kornerup, A., acknowledgments to. _______ . _____ ...... ___ ....... 44,61 

Koyukuk River region (lower), geology of.. __ ._ ....... ___ ... _._ 579,635 

Koyukuk River region (upper). See Chandalar-upper Koyukuk 

River region. 

Kiibel, S. J., aid of.._ ....... -....... ____ . _____ ............ _____ .. 21 

Kuiu Island, geology of. ... _ .... -... _._ ... _ ..... _ ........... _ .. 262-263 

Kiimmel, H. B., acknowledgments to .. _ .. ___ ............... __ 44,58,59 

cited .......... -.. --- .......... -.... 113, 179, 240-242, 294-296, 522-526 

publications by, list of.- ......... _ .............. _ .......... 853-854 

Kush taka formation ................................ _ ......... __ . 789 

Kuskokwim Valley, authorities on .............................. 61,633 

geology of ........... -.................................. 579, 633---<l34 

publications on.............................................. 52 

See also Bristol Bay. 

L. 

La bette shale.... . . . . . . . • . • . • • . • • . . . . . • . . . . . . . . . . . . . . . . . . . . 457, 458, 463 

LaBiche shale ..................................... _ ..... _ .... 699-700 

Labrador, authorities on......................................... 60 

geology of ....................................... _.... . 13, 62, 68, 149 

publications on ................................. _ ......... 33,45-46 

Labrador series .... _ .................................... _........ 145 

Ladore shale ........................................ _ .......... 458, 464 

Lafayette formation .............. __ .. __ . 9, 746,749,794,804-805,812-813 

Laflamme, J. C. K., acknowledgments to .. _._ ................... 44,60 

La Forge, Laurence, acknowledgments to ____ .. _ .. _._ ............ 44,57 

La Forge, L., and Sayles, R. W., cited._......................... 470 

publication by_____ ........................ 859 

Lagarto formation --.................... _. .. .. .. . . . .. . .. .. .. .. .. . 804 

Lagrange group . -...... -.. -.... -. -.. _ . _ . _ -. _ .. ___ . _ _ .. _ .. 728, 734-735 

Lagunillas conglomerate .. .. . .. . .. .. . .. . . . .. . . . .. . .. .. .. .. .. .. .. . 583 

Lake Clark region. See Iliamna-Lake Clark region. 

Lake Louise formation .. _ .. _. . .. .. .. . .. .. .. .. .. _ ...... _ . _ .. .. . . 154 

Lake Superior region, geology of. ...... _ .. ___ ._._ ... _ ..... _ ...... 14, 15 

Lakota formation ..................................... _ ... _ 672,685,691 

La Motte sandstone ............•.... _ ............ _ . . . . . . . . . . . . . . 104 

Lancaster formation._ ..................... __ .. _ .... _ .......... 329,331 

Lance Creek formation ............ _ .... _ .. __ .. _ 10,687-688,706,761-763 

Lane, A. C., acknowledgments to ................................ 44,58 

cited ... _ .. _ ....... _ ........ 194---195,245,246,313,314-315,426-423,468 

publications by ................................. _ .......... 250,854 

Lane, A. c., and Seaman, A. E., publication by................. 854 
INDEX. 881 

Page. 

Lane, A. C., and others, cited .................................. 246-248 

publications by ............................................ 840, 854 

Lane shale............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 458, 464 

Langdon, D. W., cited........................................... 732 

publication by.... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 854 

Langdon, D. W., and others, publication by..................... 860 

Langston formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 

La para formation.... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 804 

La Platasandstone ............................. 481,513,514,518,557-561 

Lapworth, Charles, cited ............................... 133,206-209,220 

publications by, llst of. . . .. . .. . . . . . . . . . . . . . . . . .. .. . . . . . . . .. . . 854 

Laramie formation ....................... 10, 11, 20,637,648,661-665,667, 

674-676, 679-681, 685-686, 694-697, 699, 762-764, 767-768,774 

See also Late Upper Cretaceous; Upper Laramie. 

Las Esperanzas formation ..................................... 648,649 

Late pre-Cambrian, content of................................ 14 

distribution of. .............................................. 13,64 

representation of, on map ...... __ .... _ .. _ ........ __ ..... _.... 13 

Later Tertiary (Miocene and Pllocene), content of. ............... 9, 794 

rustribution of. .......................................... 9, 794,796 

details of. . .. .. . . . . . . . . . .. . . . . . . . .. .. .. .. . .. .. .. . . . . . . . 798-832 

map showing .......................................... .. 795 

representation of, on map ................................... . 9, 794 

Latest Cretaceous. See Earliest Tertiary or late"t Cretaceous. 

Late Upper Cretaceous (Laramie), content of ......... . 

distribution of. .................................. .. 

details of. ...................................... . 

10,637 

10,637,639 

.... 639-705 

map showing.................................. 638 

representation of, on map. . .. . . . . .. .. .. .. .. .. . .. .. .. . . . . . . . . 10, 637 

See also Upper Cretaceous. 

Lauderdale formation .......................................... 403,415 

Laurel limestone ........................................... 232,234-235 

Laurentian system, classification of. ............................. 68-69 

Laurentian (Canadian usage), content of. ....................... 15, 138 

distribution of. ....................................... 15, 16, 62, 137 

representation of, on map.................................... 15 

Laurentian series (Lake Superior region), content oL............ 15 

distribution of. .............................................. 15.62 

representation of, on map.................................... 15 

Lawrence shale . .. . .. . .. . .. .. . .. .. .. . .. .. .. .. . .. .. . . . .. . . . .. . . . 458, 464 

Lawson, A. C., acknowledgments to ....................... 21, 44, 57,60 

cited ............................................ 94,554-655,815-816 

publications by, list of........................ .. .... 854 

Lazeart sandstone . .. . . .. . .. . . .. .. .. .. .. . .. .. . .. . 676 

Leach, "\V. W., acknowledgments to ............................ 44,60 

cited ................................................... 386, 630-631 

publications by, list of........... 854 

Leadville limestone ........................................ 367-369,371 

Lebanon formation ...................... . 

l>e Claire limestone ........................... .. 

164, 165, HiS, 172 

........ 242-243 

Lecompton formation . . . . . .. .. . .. .. .. .. .. .. .. .. .. . . . . . ... 458, 4!i4 

Lee, W. T., acknowledgments to. 44,56,57,58 

cited. . . . . . . . . . . . . . . 362-363, 506, 662, 664, 760 

publications by, list of...... 854 

Leeformation.................................... 448,450,451 

Lees, J. H., publication by.......................... 854 

Legend of map, details of....... .. .. .. . 9-16 

Legibility, restrictions of, on accuracy in mapping....... . .. 8, 21-22 

Lego limestone .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 235 

Leipers formation....................................... 168 

Leith, C. K., acknowledgments to........ . ..... 44,58,59 

cited....................... ....................... 62 

Leith, C. K., and Van IIise, C. IL,publication by.......... 862 

Leith, C. K., and others, publication by . . . . . . . . . . . . . . . . . . . . . . . 840 

Lenapah limestone .. .. . .. . .. . . . .. . .. . .. . .. . . .. .. . . . 461,463,464 

Lenk, H., and Felix, J., cited .. _ 549J 551,797 

publication by................ ........... 849 

Lennep sandstone ........................ , . . . . . . . . 687 

Leonard, A. G., acknowledgments to...... 44,58 

cited.... .. .. .. .. . .. .. . 691 

publications by............................ 764,854 

Leonard, A. G., and Smith, C. D., cited............. . .. 777-778 

publication by.................. 854 

Le Rouxformation _ ... ------ .. ________ .. __ . _ __ ___ 514 

Leroy, 0. E., acknowledgments to... .. .. .. .. .. .... .. .. . 44,60 

Le Roy shale . .. .. .. . .. .. .. .. .. . . .. .. . . .. .. . . . . . . . . . . . .. . . . . . . . 458, 464 

Lesley, J.P., acknowledgments to...................... 45,59 

cited........................................................ 239 

publication by............................................... 854 

48011°-12--56 

Page. 

Leverett, Frank, acknowledgments to ............................ 45,58 

Levis formation ................................................ 202,215 

Lewes River, geology of. . . . . . . . . . . . . . . . 549, 576, 639, 700-701 

Lewis, J. V., acknowledgments to.. .. ...................... 45,58 

Lewis shale................................... 660,661,674-675,679-681 

Lewistown field, Mont., geology of...... . ............. 687-688 

Lewistown limestone .................................. 231,239,274,286 

Liard River, geology on ........................... 500,542-543,796,836 

Liberty formation....... .. .. .. .. .. .. .. . .. .. .. . .. .. .. .. 172 

Lime Creek formation ......................................... 290,410 

Linden formation .............................................. 27&-276 

Lindgren, Waldemar, acknowledgments to .............. 45, 56, 57, 58,59 

cited ......... 81-82,272,273,362--363,364,380,522,533-534,555,646-647 

publications by, Jist of...................................... 854 

Lindgren, W., and others, publication by..................... 854 

Lines, E. F., acknowledgments to.............................. 45,59 

I>iniettaclay ................................................. 416,417 

Lisbon formation.......................................... 735,737 

Lisburne formation...... . ...... 12,355,396-397 

Little Clarksburg coal . . .. .. .. .. . .. . .. .. .. .. .. .. . .. .. . . . . . . . . .. . . 436 

Little Falls dolomite .......................................... 186-187 

Little Pittsburg coal.......................................... 455 

Little River group ............................................ 327,329 

Littleton Township, N. II., geology of........................... 250 

Livingston formation............................................ 687 

Llandovery formation . . . . . .. .. . .. . .. . .. . .. . . .. . . .. . . . . . . . . . . .. . . 261 

Llano-Burnet district, Tex., authorities on ...................... 77,595 

geology of. ....................................... 77-80,579,598-601 

Lockatong group ...................................... 522--523,526-527 

Lockport dolomite ......................................... 237,238,245 

Lodore shale................................ . . . . . . . .. .. . . . .. .. . 175 

Logan, W. E., acknowledgments to .......................... 45, 60,130 

cited ...................... 131-132, 134,148-153, 183, 197, 198, 20&-206, 

208,209-210,211-213,245,254-255,259-260,292--293, 334,423,497 

publications by ................................ 203,250,252,254,854 

Logan shale ................................... 239,407,408,414-415,430 

Lone Mountain limestone .......................... 168-169,236,282-283 

Longfellow formation.......... . ..................... 158, 159 

Long Island, geology of. ....................... 609,612,682,745,794,823 

See also New York. 

Longmeadow brownstone . .. . .. . .. . . .. . .. . .. . . .. .. . .. . .. .. . . .. .. 532 

Longwood shale .. .. . .. . .. . . . .. . . .. . .. .. .. .. . . . .. . .. .. .. . .. .. 238, 241 

Lookout sandstone ................................ 448,449,452,453,455 

Loomis,F.B.,cited..... .................................. 775 

publication by............................... 854 

Loon River shale................................ . ........... 699-700 

Lorraine group .. .. . .. . . . . . . . .. . .. . .. . .. . . . . .. . . . . . . . .. .. . . . . . 166-168, 

172, 184,187,189-191, 194, 195,196,197-199,201-203 

Louderback, G. D., acknowledgments to..... .... . .. .. .. 45 

cited.......................................... 556 

publication by............. 555 

Louisiana (H-I 15), authorities on ....................... 57,604,723,804 

geology of.. ............. 11,579,604-605,654,706, 723-731,794,804-805 

publicationson................................. ... . .. 31,42,54 

See also Gulf coast; Mississippi embayment. 

Louisville limestone.................................... 232-233,235 

Loup Fork group................................. 769-770,822,834 

Low, A. I'., acknowledgments to ............................ 45-46,60,61 

cited ............................... 220-221,264,265,268,399-400,547 

publications by ............................................ 254, 855 

Lower California (F-H 11-12), authorities on ............... 644,646,647 

geology of.. ................................. 10,637,644-647,794,799 

See also I'acific coast: Mexico. 

Lower Cretaceous system, content of. _______ ._._.__ _ ____ 11,579 

distribution of...... .. .......................... 11,579 

details of.................................. . .......... 581-636 

map showing............................................. 850 

representation of, on map....... .. .. 11,20,579 

Lower Helderberg series ............................ 251,254,291,297-298 

See also Helderberg. 

Lower Huronian. See Middle and Lower Huronian. 

Lower Magnesian limestone ........................... , ........ 119-120 

Lower Mottled limestone............................. 218-219 

Lower Ordovician system, distribution of......................... 75 

See also Cambrian and Lower Ordovician. 

Lowville limestone ............................. 183-186, 191,194,209-210 

Lucas, F. A., publications by, list of............................. 855 

Lucas dolomite: ............................................... 233,248 

Ludlowville shale .. .. .. .. .. .. .. .. .. .. .. .. .. .. .................... 297 
882 INDEX. 

Page. 

Lupton, C. T., acknowledgments to ........................... 4o,5~.59 

publications by ............................................ 776. S55 

Lykens formation.......................... ... 440,446-447,516 

Lyons formation................................ . ........ 370,51G-517 

M. 

McAdam formation ............................... . 

McAlester shale ..................................... . 

McBean formation .................................... . 

.. 251-252 

... 458,462 

736 

McCalley, Henry, cited.................... 454 

publications by, list of............. 855 

McCallie, S. W., acknowledgments to................. .. 46,57 

publication by........................................ . .... 855 

McCloud shale ............................................. :ml-:377,519 

McConnell, R. G.,acknowledgmentsto ........................ 46,60,61 

cited. . . . . . . . . .. . . . . . . . . . . . . . . . 154, 207, 258,263,333, 33f,...337, 388-389, 

391, 541, 543, 694, 695,698, 699,700, 703-704~ 785, 834, 83()-.838 

publications by, list of................................. . ...... 855 

MacDonald, D. F., cited... . . . . .. . .. . . . . .. . .. . . . . . . 382 

McElmo formation.................................. 513.557-559 

McEvoy, James, acknowledgments to............ . .. 46,60 

cited.......................................... 694 

publication by................................... 855 

McFarlane, Thomas, acknowledgments to.............. 46, GO 

McGee, W J, acknowledgments to............................... 366 

cited,..................... . ............................. 812,855 

Machuca fonnation ........................................ 709,710-711 

Mcinnes, William, acknowledgments to .................... 4G-47,60, ~il 

Mcinnes, W., and Bailey, L, W., publications by .............. 254,841 

Mackenzie Valley, authorities on ....................... 264, 33G-337, 837 

geology of .............. 225,264,269,336-337,639, 703-704, 796,837-838 

See also Pel! River; Arctic coast of Canada. 

McLeansboro formation ....................................... 467-468 

McMicken formation............................................. 172 

McMillan formation.............................................. 172 

MeOuat, Walter, acknowledgments to ........................ 47, 60,61 

Macoun, John, acknowledgments to .............................. 47,60 

cited................... .............. ......... . ......... 336 

publication by . . .. . .. . .. .. . . . . .. . . . . . .. .. .. . . . . . .. .. . . . . . . . . 855 

Maddren,A. G., acknowledgments to ............................ 47,61 

cited......................................................... 634 

publication by............................................... 855 

Maddren, A. G., and Moffit, F. H., cited...................... 543 

publication by........................................ .. .. .. 856 

Madera limestone .. .. .. .. . . . .. .. .. . .. . . .. . .. . .. . .. . . . .. . .. . . . . . .. 362 

Madison limestone ................................. 321,371,381, 38G-387 

Madison Valley formation............................... 834 

Madrid group........... .. . .. . . . . .. . .. . . . . . . . . . . . . . . . . . . . . . . . 662 

Magdalena group.......................... 362 

Magnesian Limestone series ............................ 103-105,169-170 

Magog shale......................................... . ... 204,206,250 

Magothy formation ........................................ 609-614, 659 

Mahoning limestone, etc......................................... 437 

Maine (L-19), authorities on .................... 57,1:34,252,255,326,327 

geology of. ....................... 17, 72, 134-135,225, 252-25fi, 327-328 

publirations on .. .. .. .. .. . . . . . .. .. . .. . .. .. . . . . . . . 32, :l4, 51-52,55 

See also Atlantic coast; New England. 

Main Street formation ......................................... 604,650 

Malloch, G. S., acknowledgmento to.............. 60 

Mal pais gravel .. .. .. .. .. . . .. .. . . .. .. .. .. .. .. .. . . . 349 

Maltrata limestone.................................. . ....... 587-588 

Manasquan formation. . .......... 11,609,612,637,749 

Manastash formation .............................................. 774 

Manchioneal fonnation. . . . . .. .. . . . . .. .. .. . .. .. .. .. .. .. .. .. .. .. 800, 801 

Mancos formation .......................... 558,660, 661.671, 674,678, 679 

Mangum dolomite............................................... 487 

Manitoba (M-N 14-15), authorities on ....... 60,217,219,262,335,695-697 

geology of. ...... 62, 156,214,217,219,225,261-262,269,335,639,695-698 

publications on ................................ 33, 44,45-46,51,52,53 

Manitoulin formation .. .. . .. . .. . .. .. . .. .. .. . .. . .. .. . .. .. .. .. .. . .. 245 

Manitoulin Islands, geology of. ......................... 195-196,245-246 

Mankomen formation ....................................... 12,355,394 

Manliuslimestone .................................. 239,241,242,245,274 

Mansfield, G. R., cited........................................... 570 

publication by............................................... 855 

Mansfield sandstone ....................................... 413,467-469 

Manzano group . .. .. .. .. .. .. .. . .. .. .. .. .. .. .. . .. . . . .. . . .. . .. .. . 362-363 

Map, ge.ologic,explanation of .................................... · 6 

subdivisions of, plan of. ..................................... · 6 

Page. 

Mapleton sandstone ............................................ 328,329 

Maps, authorship of.............................................. 21 

Maquoketa sbale ............................... 171.176, 180, 182-183,195 

Marais des Cygnes formation .................................. 457,458 

Marble Falls limestone........................................... 427 

Marbut, C. F., publications hy............ .................. 457 

Marcellus shale ............................ 2.o.0,294,295,297,302,304,317 

Marcou, Jules, cited....... 50G-507, 517 

Marianna limestone ..... ___ ....... _ ... ___ .... __ ... 740 

Marine Eocene, content of .. __ .. 

distril)ution of.. ...................... . 

representation of, on map ..... ___ .... . 

See also Earlier Tertiary. 

Marine Oligocene, content of. .............. . 

distribution of.. ............ . 

representation of, on map .......... . 

See also Earlier Tertiary. 

Marine Pliocene, classification of. ...... . 

Marion formation ...................... . 

Mariposa slate ................................ . 

Marjum formation ................................ . 

Marks Head marl. ................................ . 

9,10 

10 

10 

9 

9 

9 

9, 794 

465 

ll, 549,555,618 

107 

807-808 

Marlbrookmarl.................................. 652,653 

Marmaton formation . . . . . . . . . . . . . . . . . 457,458 

Maroon'conglomerate............................. .... . . . . 368-369 

Marsh, 0. C., cited................................. . . .. .. . . .. . 516 

publication by................................. 855 

Marshall formation................................. 420,422,458 

Marshalltown formation .. . . .. .. .. . . .. .. .. . .. . . .. . 609 

Marsouin River format.ion . . .. . .. . .. . .. . . .. . .. .. . . .. . .. . . . .. . 208 

Marthas Vineyard, geology of..................... 682,683,749,796,823 

Martin, G. C., oeknowledgmenis to................ . .. 47,57,.59,61 

cited.................................. . .... 575,788 

puhlieations by, list of....................................... 855 

Martin, G. C., and Clark, W.B., publication by........... 844 

Martin, G. C., and Katz, F.J.,publication by................... 855 

Martin, G. C., and Stanton, T. W.,cited........ 541-542,574,631,783 

publications hy................................ 855,861 

Uartin, K., cited.......................... 639 

publicationby................................. 855 

Martinlimestone................................ 271 

Martinez formation............ . . .. . . .. . . . . . .. . . 751,753,815,818 

Martinsllurgshale ...................................... 109,179,239,240 

Marvine, A. R.,puhlication by................................... 8.55 

Maryland (J 17-18), authorities on .. 57,173,174,274,275,2R5,417-419,527 

geology of.. ..... 64, 65,156,175,177,237,239,269,274-275,285-286,313, 

401,417-420,442-452,500,524,527,610-611,612-613,745, 741)..749 

publications on ....................... 31,33-36,43,47,50-53,55 

See also Atlantic coast; Appalachian Mountains. 

MaryYillelimestone. ... ............ ... .. . .. . .. . .. . . . . . . . . . 92-93 

~fascalJ formation---- ......... --- __ . 824 

Massachusetts (K 18-19), authorities on .......................... 57-58, 

114.115,116,192,194,469,470,532,682,683 

geology of .......................................... 64, 72,114-116, 

1.56,192-194,425,469-472,500,532,639,682-684 

publications on ............................ 32, 36, 39, 43, 49, 50, 52,55 

See also Atlantic coast; New England. 

Massanuttensandstone................................. 231 

Massillon sandstone .............................. . 

Matanuska Valley, authorities on ....... . 

geology of. ................................ .. 

publications on ............................. . 

See also Cook Inlet. 

434 

... 61,788 

.... 708,788 

...... , 44,47,48 

Matawangroup ........................................ 609-614,659,682 

Material, arrangement of.............. . . .. . . . .. .. . . . .. .. 6-7 

character and source of.................................... 5-6 

Matfield shale.................................. 465 

Mather, W. W., puhlications.by ................................ 304,855 

Mathews, E. P., acknowledgments to ......................... 47,57, 59 

publications by ........................................ 177,844,855 

Matson, G. C., acknowledgments to ............ 47,56,.57,58, 731, 744_,804 

cited......................................................... 730 

Matson, G. C., and Berry, E. W., cited........................... 80 

Matson, G. C., and Clapp, F. G., cited ................. 740-741,808-811 

publication by.............................................. 855 

Mattawa, geology of.............................................. 196 

Matthew, G. F., acknowledgments to ............................ 47,60 

cited ....................................... 13G-139, 145-147,326,756 

publications by, list of ..................................... 855-856 
INDEX. 883 

Page. 

Matthew, P. F., and others, cited .............................. 325,320 

publication by.............................................. 841 

Matthews, W. D., cited................................... 759 

Mauch Chunk formation ............................... 408,417-419,430 

Maury, C. J.,publication by...................................... 850 

Maury shale ................................................... 277-278 

Maxville formation .................... 406-407,408,414,418,420,423,430 

May Hill sandstone.............................................. 261 

May Pen formation....... . ............................... 721,800 

Maysville shale.................................................. 194 

Meadville shale ................................................ 414,415 

Meagher limestone. .. .. . . .. . . .. . .. . . .. .. . .. .. .. .. . .. . . . . .. .. .. .. . 128 

Medicine Lodge gypsum......................................... 487 

Medina formation ............... 13, 19.5,197-198,237,238,239,244-245,251 

Meek, F. B., cited .............................................. 204,265 

fossils identified by ......................................... 237,407 

publications by ............................................ 704,856 

Meek, F. B., and Hayden, F. V., cited........................... 762 

publication by............................................... 856 

Megurna series ......... ---------------------------------------- 14,16 

Meinzer, 0. E., acknowledgments to._ ... _...................... 47,58 

Meinzer, 0. E., and others, publication by....................... 851 

Mendenhall, W. C., acknowledgments to ...................... 47,57,61 

cited ........................................... 354, 394, 505-500, 791 

publications by, list of. ........................................ 856 

Mendenhall, W. C., and Campbell, M. R., publication by........ 843 

Meniscus limestone.............................................. 235 

Mentor formation................................................ 614 

Meramec group ........................................... 411,413,458 

Merced formation ...................................... 753,815,816,818 

Mercer limestone................................................ 434 

Merchantville clay.... .. . . .. .. . .. . . . . . . . . . . .. . .. .. .. .. .. .. .. .. .. . 609 

Merom group .................................................. 467-468 

Merriam, J. C., acknowledgments to ........................... 47, 57,59 

cited ....................................... 621,752,772-773, 82(}...830 

publications by, list of. ........................................ 856 

Merriam, J. C.,and Sinclair, W. J.,publication by............... 856 

Merrill, F. J. H., acknowledgments to ........................ 47,58,245 

cited........... . .................................. 183,187,194,245 

publications by ............................................ 238,854 

Merrill, F. J. H., and others, publication by...................... 856 

Merrill, G. P., and Emmons, S. F., cited......................... 647 

publication by............................................... 849 

Merritt, W. M., acknowledgments to ............................. 47,60 

Mesa sandstone ................................................ 64-Hl47 

Mesaverde formation.. . .. 11,637,660,661,671,674,675, 678-{)81, 766 

Metamorphic Paleozoic, undivided, content of. .................. 13,342 

distribution of........................................ 13 

details of.. . . .. . . . . . . .. .. . . . . . . .. .. . . . . . . . . .. . .. . .. . . .. . 342-354 

map showing...................................... 343 

representation of, on map .. __ ... __ ....... ___ . . _______ . 13,342 

See also Paleozoic, undhrided. 

Metamorphic rocks, representation of._ ........ _____ 29 

Meta pan formation.............................................. 585 

Mexico (E 13-15, F-II 12-14), authorities on...................... 21, 

50,227,504,505,589, 644-{)48, 797 

geology of.... . .................................... 9,10,!1,12, 

13, 20, 64,225,227,500,504-505,579,589-591,637,648,794,797 

publications on .................................. 31,34,42,48,50,55 

See also particular States. 

Michigan (K-L 1(}...17), authorities on ............................... 58. 

118-120, 194,195,245-250,313,314,420-423,468 

geology of. ............................. 14,15, 62, 64, 72,118-120, 156, 

194, 19&-225, 24(}...250, 269,313-315,401,420-423,425, 4G8-4D9 

publications on............. .. .......... 32,44,45,50,54 

Michigan formation............................. . ............ 422-423 

Michoacan (E-F l:l-14), geology of.......... 589-590 

See also Mexico. 

Middendorf beds..................................... G59 

Middle and Lower Huronian, content of...... 15 

distribution of.._._ .. _.__ _ _ ...... _ ..... _ 15,64 

representation of, on map................................... 15 

Middle and Upper Ordovician, content of. ...................... 13,156 

distribution of........ . ................................ 13, 75, 156 

details of.... .. . . . . . . . . . . . . . . . .. . .. .. . .. .. . .. . . . . .. . .. . . 158-224 

map showing. . . . . .. .. . .. .. . .. . . . . . . .. . .. . . . . .. .. . . . . . 157 

representation of, on map ................................ 13, 17,156 

Page. 

Midway formation ............................. 653,723-725,731-734,748 

Mierisch, Bruno, cited ......................................... 502-503 

publication by............................................... 856 

Miles City field, Mont., geology of............. . ......... 700,777 

Mill Creek limestone.......................... .. . 442 

Miller, B. L., acknowledgments to............. . 47,57,58,59 

publications by............................... .. .. 844,856 

Miller, B. L., and Shattuck, G. B., publication by........ 859 

Miller, W. G.,acknowledgments to................ 47 

Miller, W. G.,and others, publication by........................ 840 

Millersburg formation ......................................... 467-468 

Millers River conglomerate...................................... 469 

Millsap limestone.............................. 367-369,371,373,429 

Millstone grit .............................................. 383-386,458 

Millwood series............................ . ............ 697-698 

Milwaukee formation............................................ 290 

Mingan Island, geology of...... . ........................ 209-210 

Mingo formation............................ . . . . . .. . . .. .. . . . . . 450 

Minnekahta formation.................. . ..... 12,492,495 

Minnelusa formation ..... __ ......... _.. . ...... ___ . _ _ _ 372-373 

Minnesota (K-L 14-15), authorities on...... . .... 58,118-120,180,183 

geology of..... . .. 14,15, 62, 64, 72,118-120,156, 181}-183, 639,682 

publications on............... . ..... 41,44,47,54,55 

Miocene, content of...... .. .. .. .. .. .. 9 

distribution of...... .. .. .. .. .. .. 9 

representation of, on map .. _. ___ ._ ......... _ 9,794 

See also Marine Miocene; Later Tertiary. 

Mispeck group .. . .. .. . .. .. .. .. . .. . . .. .. .. . .. . . .. 327, 329,331 

Mission Creek series.................................... 792 

Mississippi (H-I 15-IG), authorities on........ .. .. .. .. ....... 58 

occurrence and character of. . .. . .. . . . . . . . . . . . . .. .. .. 655 

publications on ................. . ............ 36,47,54 

See also Mississippi embayment. 

Mississippian series, classification of.. ___ ._._._. ___ . ___ ._._....... 408 

content of. . . .. . . .. . . .. . . . . . . .. . . . .. . . . . .. . .. .. .. .. . 12, 401 

distribution of........ .. ....................... 12, 75,401 

details of........... . ............................ 401-424 

map showing ...... . 402 

representation of, on map . ... __ ........ 12,17,401 

See also Carboniferous rocks, undivided. 

Mississippi embayment, geology of........ . .. 10,700,731-745 

Missouri (J-K 15-16), authorities on... 58, 

103-105,169,236,278,408,410,411,455 

geology of .. . . . . . . . . . . . . .. .. .. .. .. .. .. .. .. . . . . . . . . . . 15, 64, 72, 

103-105, 156, 169-171,225, 236,209,278,400,407-412,425,455-458 

publications on................ . ........... 31, 34, 40, 44, 51, 52,53 

Missouri group ................................ . 

Missouri Mountain slate ...... _ .. _ .. _ ............... .. _ 

Mitchell limestone ..................................... . 

Moccasin limestone ................. . 

Modelo formation ..................................... . 

457-458,465 

100,163 

412,413 

93,174 

818 

Modin formation......................................... 561 

Modoc limestone......... . ............................ 357-358 

Moencopie formation .................................. 366,4R4,513-514 

Moffit, F. H., acknowledgments to ............................... 48,61 

cited......................................................... 791 

publication by ................................................ 856 

Moffit, F. H., and Capps, S. R., publication by..... 856 

Moffit, F. H., and Knopf, A., cited ......................... 394-395,790 

publication by.............................................. 856 

Moffit, F. H., and Maddren, A. G., cited.......... 543 

publication by............................................... 856 

Moffit, F. H., and Stone, R. W., cited ......................... 785-787 

publication by............................................... 856 

Mohawk Valley, geology of.. ................................... 186-187 

Mohawkian series............................................... 194 

Mojsisovics, E. von, publications hy, list of...................... 856 

Molas formation................................................. 371 

Moneague formation ........................................... 72D-721 

Monmouth group ..................................... 609-611,613-614 

Monongahela formation ......................... 12,432,437-439,442,458 

Monroe Creek formation ................................... 821-822,830 

Monroe formation .................................. 233,246-248,313-314 

Montana (L-M 11-13), authorities on............................. 21, 

58, 127, 128, 244,319-324,350,381,386,387,571,572,621-

623,085-690,694,695,761-764,775, 77(}...778, 831,833-834 
884 INDEX. 

Page. 

Montana, geology of............................... . . . . . . . . . . . . . . . . . 10, 

11, 13, 14,62,64,127-130,156,194,225,244,269,319---324, 

342,350,355,381-382,386--387,549,571-572,579, 621-·623, 

639,685-690,694-695,706,761-764, 775-778, 796,831-834 

publications on .. _ .... _ ..... 32, 35, 36, 39, 40, 42,43, 45, 46,48, 49,51-56 

See also Great Plains; Rocky Mountains. 

Montana group .... 648,662,670,674-676,678-681,685,690,691,699-700,767 

Montana group (coal-bearing portion), classification of............ 579 

content of. .................................................. 11,637 

distribution of.............. . ........................ 11,637,639 

details of.. ............................................ 639-705 

map showing . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . .. . . . . . 638 

representation of, on map ................................... 11,637 

See also Upper Cretaceous. 

Monterey shale ............................... 9, 231,286,753-754,814-818 

Montevallo limestone .......................................... 164-165 

Montgomery limestone . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . .. .. . . . . . . 242 

Montoya limestone ............................................. 75, 158 

Montpelier formation . .. . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 720 

Montreal (St. Helene Island), geology of. .................. 269,324-325 

Mont-Serrat, E. de, and Dollfuss, A., cited....................... 549 

publication by . . . . . . . . . . . . . .. . . . . .. .. . . . . .. .. . . . . . . . . . . . . . . . 848 

Monument Creek formation ................................... 757-758 

Moorefield shale................................................. 4ll 

Moose River sandstone ........................................ 328,329 

Morenci formation ............................................. 272,358 

Morgan formation . . . .. . . . .. . . .. .. . . .. .. .. .. . . . . . . . . . . .. . . . . .. .. . 379 

Morgantown sandstone . . . . . .. . . . . .. . .. . . . . . . . . . . . . . . .. . . . .. .. .. . 436 

Morita formation . . .. . . . . . . . . . . .. . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . 592 

Mormon sandstone . .. . .. . . .. .. . .. . . . .. . . . . . . . . . . .. . .. . . . . .. . . . . . 563 

Morrison formation ....... ~- ..... __ ............. _................ 530, 

567,.569-570,572,607-608,621-623,678,685,687,691 

Morrow formation............................................... 458 

Morse, W. C., and Foerste, .\.F., cited ........................ 415-417 

publication by,.............................................. 856 

Morton, S. G., publication by.................................... 856 

Moruga series ................................................. 704, 716 

Moscow shale ................................................. 297,304 

Mound Valley limestone ....................................... 458,464 

Mountain limestone ....................................... 401,403,418 

Mount Auburn formation........................................ 172 

Mount Hope marl.. ............................................ 172,737 

Mount Laurel sand. . . . . . . . . . . . . . . . . . . . . . . . .. .. . . . . . . . . .. . . . . . . . . 609 

Mount St. Elias Range, geology near. .............. 3.55, 394-395,500,542 

See also Nabesna-Whlte River region; Alaska, southern; 

Alaska, southeastern. 

Mount Selman formation . .. . . . . . . . . .. . .. . . . .. . . .. . . .. . .. . 724, 726, 727 

Mount Stephen formation........................................ 145 

Mount Toby conglomerate....................................... 532 

Mount Whyte formation......................................... 154 

Mount Wrangell district, geology of. ........................... 708,790 

Mowry sandstone .............................................. 680-681 

Moydart formation .. . .. .. .. .. . .. . .. .. . .. .. . .. .. .. .. .. . 251 

Munn, M. J., acknowledgments to ................................ 48,ii9 

publication by............................................... 856 

Munn, M. J., and Shaw, E. W., publication by.................. 859 

Mural limestone ............................................... 592-593 

Murchison, R., cited............................................. 222 

Murphrccsboro limestone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168 

Murphy marble............ . . .. .. .. . . .. .. . .. . .. .. . . . .. . .. . .. .. .. 98 

Murray, Alexander, acknowledgments to ...................... 48,60,61 

cited ................................................... 256--258,389 

publication by............................................... 856 

Murray slate .............................................. 91-92,95,96 

Muscogee group ................................................ 460-463 

Myers shale .................................................... 418-419 

Myrtle formation .......................................... 565,617-618 

Mystic coal.. .. .. .. . .. . .. . .. . . .. . .. ... .. .. .. .. . .. .. .. .. .. .. .. .. .. 466 

N. 

Nabesnalimestone ............................................. 12,355 

Nabesna-White River region, geology of.. ...................... 394-395 

See al/Jo Tanana basin (upper). 

Nacatoch sandstone ........................................... 652-653 

Naches formation ................................ ·................ 774 

Naco limestone ................................................ 357-1!58 

Nahcola formation ........................................ 731,732,733 

Naknek formation .......................................... 11,549,574 

Nanafalia formation ........................................... 733,734 

Page. 

Nanjemoy formation ....................................... 746--743,749 

Nantahala slate.................................................. 98 

Nantucket, geology of.. . .. .. . .. .. . . . . .. .. .. .. . . .. .. .. .. . . .. . . .. 796, 823 

Nanushuk series ............................................... 636.792 

Naparima marL ................................................. · 714 

~:~~~~:~~:;,:,~ti~~-:: :::::::::::::::::::::::::::::::::::::::::. ·~~ Nariva series.................................................... 714 

Nashuamarl .................................................... 810 

Nashville formation ........................................... 164,168 

Nathorst, A. G., acknowledgments to ........................... 48,61 

cited ........................................... 224, 341, 547, 577, 793 

publications by ............................................. 546,856 

Navajo Church sandstone........................................ 513 

Navarro formation ...................................... 11,637,650,651 

Navesinkmarl................................................... 009 

Nebosandstone ............................................ 91-92,95,96 

Nebraska (K 13-14), authorities on .............. 58,672,685,769,821-823 

geology of .............. 456,639,672-673,685,706,769-770,794,821-823 

publications on ..................................... 32, 36, 42, 52,53 

See also Great Plains. 

Necoxtla slate............................ .. ........ 587-588 

Needle Mountains, geology of.......... . . . .. .. . . .. . . . . . . . . . . .. 13 

Needle Mountains group, classification of......................... 14 

distribution of................................................ 64 

representation of, on map..................................... 64 

Neocomien series................................................ 582 

Neosho formation................................................ 465 

Nevada (J-K 11), authorities on................................. 58, 

98-102, 168-169, 236, 282, 283,364,521,527,556,750,819,820 

geology of ................................................. 9, 11, 12, 

13, 64, 72, 98-102, 1<>6, 168-169, 225, 236, 269, 282-284,355,364-

365, 376, 509, 521, 527, 5~8, 549, 556,706,750-751,794,819-821 

publications on ...................... 32,39, 41, 44, 45, 50,52,53, 54,55 

See also Great Basin. 

Nevada limestone ............................................. 282-283 

Neva limestone ................................................ 458,465 

New Albany shale ............................. 275,280,317-318,412,413 

Newark group .......................................... 12,524-527,535 

Newberry, J. S., acknowledgments to............................ 58 

cited .............. _ ................. 363,503,517.557,559,623, 77~,856 

New Brunswick (L 19-20), authorities on........................ 60, 

135_, 136, 138, 139, 207, 325,326, 333,334,383, 384, 473, 497-498 

geology of. ............ 12, 16, 62,72, 135-142, 156,207,225,252-256,269, 

325-327, 333-334, 35.5, 383-1!84, 401, 423, 425, 473, 474,497-498 

publications on ............................ 31-32,38-39,43,46--50,56 

New England (K-L 18-20), authorities on........................ 21 

geology of. ................................ 16, 17, 72,114,609,745,749 

Newer Parian group ........................................... 714-716 

Newfoundland (L--M 21-22), authorities on....................... 60, 

139, 149,153, 156,211-214,217,256,257,389 

geology of ................................ 12, 13, 14, 16, 62, 64, 72,139-

145, 149-153, 156, 211-217, 225, 256-258, 355, 389-390, 401,425 

publications on ........................................... 33, 43,48 

New Glasgow conglomerate ............................. 12,385,386,497 

New Hampshire (K-L 18-19), authorities on ................ 58,192,250 

geology of .......................................... 156,192,209,250 

publications on ........................................ 32,42,43,52 

See also New England. 

New Jersey (J-K 18), authorities on.............................. 58, 

113, 176, 177, 179, 238-240, 294, 522, 526 

geology of ........................ 11, 16,64,156,176--179,225,238-242, 

269, 293-296, 500, 522-526, 609-610, 612-613, 745-746, 748, 823 

publications on ............................ 32-36,44,47,48, 50, 52,55 

See also Atlantic coast. 

Newman limestone .... : ................................... 287,406,415 

New Mexico (I-J 12-13), authorities on............ . . . . . . . . . . . . . 58, 

159, 169, 228, 273, 484, 506, 507, 513, 606, 661-665, 757, 813 

geology of ................................................ 10, 11, 12, 

15, 64, 72, 81-82, !56, 158-159, 169, 228, 269, 273, 474, 484, 500, 

506--507, 513-557, 579, 606--608, 637, 660-667,706,757,794,813-814 

publications on .......... 32, 35,36, 38, 40, 41, 42, 44, 47, 49, 50, 51, 53,55 

New Richmond sandstone................................ 118 

New Scotland formation ....................... 279,282,294-295,297,300 

Newsom, J. F., acknowledgments to ............................. 48,57 

publications by ............................................ 413, 856 

New York (K-L 17-18), authorities on........................... 58, 

114, 120, 123-126, 183-192, 237, 245, 297-313, 522,682 
INDEX. 885 

Page. 

New York, geology of ......... _ ........ 12, 13, 16, 64, 65, 72, 114, 120-127, 

156, 183--192, 225, 237-238,245, 269, 297-313, 522-524, 639, 682 

publications on ......................... 35,36,40,41,44, 47, 50, 53,55 

See also Long Island; Appalachian Mountains. 

Niagara series ............... 75,183,234,236,238,239,243-246,250,251,282 

Nicaragua (C-D 16-17), authorities on .................. 345,509--503,709 

geology of ........................... 64,342,345,509-503,706,709-711 

See also Central America. 

Nichols shale .............................................. 91,92,95,96 

Nickles, J. M., publications by, list of............................ 856 

Nicola formation ....... _ ... __ .................................. 538-539 

Nicolas, F. J.,publication by .................................... 856 

Nictaux beds. ___ . _____ . __ ....... __ .............. _............... 252, 

Nijavi shale..................................................... 643 

Nikolai greenstone ........... __ ... _ .................... 337,394-395, M4 

Niobrara group .. _. 648,662-663,668,672-673,674,676,681,685,691,693,697 

Nipigon series................................................... 14 

Nipissing Lake, geology of....................................... 196 

Noel shale ....................................................... 411 

Nolichucky shale ............................................. 92-94,96 

Nomegroup ..................................................... 265 

NordenskjOld, Otto, acknowledgments to ......................... 48,61 

Normans Kill shale .................................... 184,187,189--190 

Norristown group . . .. .. . . .. .. . .. • • .. • • • .. .. .. . .. .. .. .. . .. .. . . . .. 458 

North Carolina (I-J 17-18), authorities on ............. _ .. 58, 89,508,509 

geology of. ........ _ ........................... _ .... __ ....... 11, 

12, 64, 65, 71, 72,89--98,500,508-510,611-613, ()55, 745,747-749 

publications on ...................... 33, 34, 40, 43, 45, 47, 49, 50, 52,54 

See also Atlantic coast; Appalachian Mountains. 

North Dakota (L-M 13-14), authorities on ....... 58,691,761-764,777-778 

geology of .......... _ ....... 10, 13, 62, 64,634,691,706,761-764,777-778 

publications on ............................ 32, 33, 35, 36, 41, 44, 49.55 

See also Black Hills. 

Northern Alaska. See Alaska, northern. 

North Park formation ................... _....................... G81 

Northwestern Alaska. See Alaska, northwestern. 

Northwest Territories (N-R 9-20), authorities on................. 60 

geology of. ...................... _._ .................... 13,62,64,65 

publications on ................... _ ..... 33, 35,37-38,43,45-46,48,53 

Norton formation ...... _ ...................................... _.. 450 

Norton Sound, geology of. ............ _ ....................... _ 708,791 

See also Yukon Valley (lower). 

Norwood, C. J., acknowledgments to ............................ _ 48,57 

Nosoni formation ............................................. _ 373,519 

Notch Peak formation ........................................ ___ 107 

Nottely quartzite ...... _ ...................................... ___ 98 

Nounan formation .......................................... _____ lOG 

Nova Scotia (L--20), authorities on ...... _ ......... _ ... _ .... ___ oo, 

250, 251! 329-332,384-386,497,498, 535J 53G 

geology of. ............. _ ......... 11, 12, 13, 14, 16, 62. 64,259--252, 2(i9, 

329--332, 355, 384-386, 389, 401, 423, 425, 474, 497-498, .135-536 

publications on ............... __ .... __ . _ 31-32,38-40,42,45,47,49-51 

Nugget formation .................................. ____ ..... ___ 494,530 

Nulato sandstone................................. 702 

Nunda group................................. .. 294,304,307-308 

Nunivak Island, authorities on.... _____ .. __ _ __ _ 61 

geology of.... . .. .. . . . . . . . . . . . .. .. .. .. . .. . . . . . . . _ . . . . 708, 787 

publications on........... ___ . ______ ... _. 

Nunnallycoal ........... ___ .. ___________ ... ___ .. _ 

Nushagak formation ... _____ . ______ .... __ .. _____ .. __ 

Nuttall formation .... ____ .. _ ..... __ .... __ .. __ ...... _ 

3G, 3i 

455 

835-836 

449,450 

0. 

Oakgrove sand .... __ ......... _______ .... __ .. _ .. 

Oakland formation __ .. ___ .. __________ ... __ ....... 

Oakville formation ... _________ ............ ________ . 

Oaxaca (D-E 14-15),authorities on .... .. 

geology of. .............. ----. 

See also Mexico. 

743 

816 

804 

549 

549,551,588,794,797 

0 bispo breccia .... __ .... __ ...... _ 711 

Ocala limestone ...... _ ............ ___ ............ 740 

Oceanic series ......................... __ ........ __ _ 640, 718-720, 799 

Ocoee group .. _._._... . . __ ..... _. 13, 72,87-88,89-90,94-98,363 

Octoraro schist ............. _ ......... ___ ... __ ....... ____ .... __ 177-178 

Odanah series ..................... __ ............. _... __ . _ .. 697-WS 

Ogalalla formation .... __ ........... __ .. ___ ... _____ ._ _ _____ 821,822 

Ogden quartzite .. .. .. . . .. .. . .. . .. .. . .. • .. . .. . .. .. . .. . 175-176, 283, 379 

Page, 

Ohara limestone .............................................. _ 409, 413 

O'Harra, C. C., acknowledgments to .......................... 48, 58,59 

publications by ..................................... __ .... _ 239,856 

Ohern, D. W., cited .. __ ._. __ .. ___ ....... ___ ._ .. ___ .... _____ . ___ 463,464 

Ohern, D. W., and others, publication by ............ __ ._ ... ___ ._ 850 

Ohio (J-K IG-17), authorities on .... _ 58, 165, 233,315,317,414-415,492,493 

geology of.. .... ____ .. ____ . ___ .. __ ............... _ __ 12, 156, 165-166, 

225, 234, 269, 315-317, 401, 414-415, 418, 432-439, 474, 492-494 

publications on ........... _ .. __ .. ____ ... _ 31,34,35,49 

Ohio Creek formation ................................... ·... 760 

Ohio shale .............. ___ ................ _______ ...... _ .. 413,416-417 

Oklahoma (I-J 14-15), authorities on .... _________ .. ____ ........ __ 58, 

82, 83,273,408,410,411, 4GO, 487,489,604,606,813 

geology of. ...... ______ . ___ .... ____ ....... __ ..... __ . . . . 11, 15, 65, 72, 

82-84,156,158, 159--160,228-230,269,273-274,400,407-412,455-

456, 458-465, 474, 476, 487, 490, 579, 604-606, 608,794,813-814 

publications on .. __ ....................................... 31,41, 53 

See also Interior province. 

Oklune series ........ _........................................... 633 

OlderPariangroup ............................................... 584 

Old Miocene, classifi~ahlon of ..................................... 9, 794 

Olean conglomerate.............................................. 297 

Olen tangy shale ................... _ ..... ___ .. __ ............. __ 315,317 

Oligocene. See Marine Oligocene; Continental Oligocene; Earlier 

Tertiary. 

Olive shale ......................................... _ ... __ ..... __ 415 

Olpe shale ........ __ ............................................. 458 

Olympic Peninsula, geology of ................. 572-573,706,778-780,832 

Omenica River, geology on ....................... __ ... 225,263,708, 7&5 

Oneida conglomerate .... __ .. __ ...... _ ....... __ .. _ ............. 237,239 

Oneota dolomite ..... _ .. __ ........................ _ .... 118,297,312-313 

Onondaga group. _ ... __ .... __ ..... _ ...... __ .... ___ .. __ . . .. . . .. . .. 245, 

275-27!', 278-281,285,289,291,295,297,309-302,304,317 

Ontario (L--M 15-17), authorities on ............... __ ............. 60, 

156, 183-192,245,250,291-293,335,336 

geology of.................................................... 14, 

15, 62, 64, 65, 156, 183-192,225,244-246,250,269,291-293.335-336 

publications on ...................... 39--33,35-39,43-48,51,52,54-56 

Oologah limestone .. .. .. . .. . .. . .. . .. .. .. .. .. .. .. .. .. .. .. . . .. .. .. 463 

Opeche formation ............................. ___ ... 12,373,492,495-496 

Orange sand .. __ ..... __ . . .. . . .. . .. .. .. .... .. . .. . .. . .. .. .. . .. .. .. . 812 

Orangeville shale .. __ .. _ .. .. .. .. . . . . . .. .. .. . . .. . . .. .. . .. .. .. .. . .. 414 

Ord6iiez, Ezequiel, acknowledgments to .................. -- ..... 48,56 

Ordovician system. See Middle and Upper Ordovician; Cam· 

brian and Lower Ordovician. 

Oread limestone. __ .... _ . ___ ...... _ .... __ .... __ . . . .. . . . .. . .. . .. 458, 464 

Oregon (K-L 19--11), authorities on. 59,349,380,527,533,534,561-564,571, 

579,G17-620,621,667-670, 764,771-773,819,824,825,826,839--831 

geology of ... ____ ...... _ ............. ___ .......... 10, 11,12,64,342, 

349--350, 355, 389--381,500,527-528,533-534,549,561-569,571, 

579, 617-621, 637' 667-670, {)85, 764, 771-773, 794,819,824-830 

publications on ... _ .......... ___ ....................... 37,38,45,50 

See also Pacific coast. 

Oriskany formation ___ . __ .. ____ .... _ ......... _ .. _ .... _____ .. __ .. _ 200, 

274-276,278-281,288,291-292,294-295,297,299--300,304, 3Hl 

Orizaba limestone ..... _ ..................... __ ........ ___ .... __ _ 588 

Orr formation .. _ ........... __ . ____ ............. _ .... __ .. _ 101 

Orton, Edward, acknowledgments to ...... _ ...... ____ . ___ .. __ .... 58 

cited .. -......................................... __ . 165,316,415,435 

publications by, list of. .......... __ ......... _______ . ____ ...... 856 

Osage group ..................... _ ......... 408,409,410, 411,413,420,458 

Osann, A., acknowledgments to ... __ ..... __ ....... __ . _________ . __ 48,61 

Osborn, H. F., cited ..... --- .. ___ ... __ ......... __ ....... ____ ...... 756, 

758-759,760, 76fi, 7G7, 770,775,778,821-822,823, 82(}-830 

publications by, list. oL ... __ .... __ .. ___ .. ________ ... __ . _ __ _ __ &57 

Osgood formation ................ __ ... __ .. . . . _ _ _ _ _ _ _ __ _ 232, 235 

Osmont, V. C., cited. ___ ...... __ ....... _____ _ _______ 61.5-616 

publication by ............... _ ...... __ .. ___ 857 

O'Sullivan, Owen, acknowledgments to............ ·------- 48,60,61 

Oswayo beds .......... __ .... _ ........... __ _ _ 297 

Oswego limestone ..... ___ . . . . . . . . . . ___ ... ___ .. _ .... ______ . _ _ _ 458 

Ottawa l3asin, geology of..._ ..... ___ .. _____ .. _______________ .... _ 196 

Otterdale sandstone ......... ____ .. ___ .. ___ .. ___ .. ____ .. ___ .. .. .. 519 

Ouachita area, geology of.. ....................... ____ .. 455-456, 458-460 

Ouachita slate ....... _ ........... __ ..... _ ..... __ ... _ ......... __ 169--161 

Ouray limestone ........................... 284-285,357,367-368,379--371 

Overprinting, effect of.. ........................... ___________ .... 23,30 
886 INDEX. 

Page. 

Owen, J., publication by ... ------···-·----------·-··-··........ 857 

Oxmoor formation .............. _ ....... _._...................... 403 

Oyster Ridge sandstone ........ _ .. _ ............... __ ............ _ 676 

Ozark series .... _ .... _ .. _ .. _ ..... __ . __ . ___ ................. 103-105,458 

See also Magnesian Limestone series. 

Pa.ge. 

Pennsylvania (T-K 17-18), author;ties on .... _ ....... ____ .... ___ 59,107, 

109, 1J 1, 176,177,179,239,285,293,294,417--419,492,493,527 

geology of. ........... _ 12, 64, 6-5, 72, 107-113, 156, 176-179,225,239,269, 

285, 293--294, 401, 417--420, 432, 442,474,492--494,500,527--528 

publications on __ ........ ____ .. ___ .. __ .. ___ 31~36, 40, 44, 45,47--53,56 

P. 

See also Atlantic coast-; Appalachian Mountains. Penusylv~nian series, content of. ______ .. ________ .. _____ .... ____ 12,425 

Pacific coast, geology of. .. _____ ..... _ ....... _._ ........ 9, 10, 11,637,794 distribution of .. _ ........... __ .. ___ .. _________ . ___ .. __ 12, 76,79,425 

Pack, R. W., acknowledgments to ..... _. ____ ... ___ . ______ ....... 48,57 details of.. .... __ .... _______ . __________________ . ____ .. .. 425--473 

Paget formation .......... _ ............ _ ...... _______ ......... ·.. 154 map showing .. ___ .... ___ .... ________ .. ______ . __ .... _ .. __ 426 

Pahasapa formation_ ....... __ ._ ...... _ ............. _._._ ... _ .. 372--373 representation of, on map .... _ .. _____ .. ____ _ ___ .. _ .. _ 12,17,425 

Paige, Sidney, acknowledgments to. ___ .. ________ .. _._._ _ _ .. 48, 59,61 See also Carboniferous rocks, undivided. 

cited .. _ ......... _ ... __ ._ .... _ 427--428,598--601,698 Penobscot Bay region, geology of.. .... _____ . _________ . _ 134--135 

publication by ............. ____ ._____ _ ______ ... _ 857 Penobscot slate .. _ ...... __ ...... __________________ ...... _ .. ____ .. 135 

Paige, S., and Knopf, A., cited._ _ _ _ _ _ ______ . . . . 788 Penrose, R. A. F., jr., publication by .... ________ . __ ............. 857 

publication by_________________________ _ ______ . _. _ 857 Pepperberg, L. J., acknowledgments to. ________________ .. _______ 58 

Paige, S., and Spencer, A. C., cited .... _ _ ______ ---- 77--80 Pequanac shale ... __ .... ____ .. _____ .. ___ .. ___ .. __ .. _______ .. _____ 296 

Painted Desert formation _________________ . _________________ . __ .. 514 Percha shale ... __ .. ___ .. __ .. ____ .... ______ .... ___ .. ___ .. ___ .... __ 273 

Painterhood limestone .... __ .... ___________ .. ---· .. ___ . _____ .---· 458 Permian series, content of. _______ .. ___ .... __ .. ___ ._ .. _ .. ____ .. _ 12,474 

Pala.che, Charles, acknowledgments to____________ _ __ . __ . _ 48,56, 58 distribution of. ... -------- .... ________ .. _______ .. ___ . ____ 12,17,474 

cited ..... _______________ _ ______________________ .. .. 782 det2ils of. .... __ .... ___ ........ __ ._ .... __ ......... ____ .. 474--499 

publication by .. _________ ._. __________________________________ . 857 map showing .. ______ .... _ .. __ .. _ .. __ .. _ .... _ .. ___ .. _ .. __ 475 

Paleozoic (undivided), content of. ___________________ . ______ . 12,13,342 representation of, on map .. __ ...... __ ......... __ .... __ .. _ 11, 12,474 

distribution of. _ . __ . _ _ _ _ _ ________________ . _ . _ _ _ _ _ _ _ 12, 17 Perry, J. H., and Emerson, B. K., cited .... __ .... __ ............ 470--472 

details of.. ______ .. _________ . __________ . ___ . ____________ 342--354 publication by ... _. ____ . _ .. ___ . __ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 857 

map showing"._. __ . _______________ . _______________ ..... _ 343 Perry sandstone ........... _____ .... __ .. __ .. __ .. _______________ 326-327 

representation of, on map._ ... ________________________ .. ____ 13,342 Petersburg formation __ .. __________ .• __ . ___ . _______ . ____ . ______ 467--468 

See also Metamorphic Paleozoic. Petoskey limestone ....... __ .. ___ .. __ .. ___ .. ___ .. ___ ... _ .. ____ .. _ 314 

Palisade conglomerate. ________________________________________ 702,832 Peyotes formation __ ... __ .. ______ .. ____ ..... _ .. __ .... _ .. _______ 648,649 

Paluxy formation .... _------ _______ -·-- ______ -----______ 606 Phalen, W. C., acknmqedgments to ... ___ . ____ ......... _ ... 49,57,58,59 

Pamelia limestone. _______ . ____ .. ____ . _________ .___ _ _. _ 183-186,196 publications by, list of. _____ .. __ ...... __ ...... __ ..... __ .... __ 857 

Pamunkey group .... __ ...... ---------- _________ .. _____________ 746,747 Philipsburg quadrangle, geology of .. __ . ___ . ______ .. _____ .. ___ • 128--130, 

Panama (B-C 17), authorities on._.__ .... _. ______ . 711 244, 320--321, 381-382, 571' 621' 686, 831--832 geology of.. .. ---. _________ . _____________ . ____ .. _____ 64,706,711-714 Pickens sandstone-- ...... _____ . ___ ... __ . ________ .. ___ . ______ .. 444,445 

See also Central America. Pictou formation • ____ ... ____ .. ___ .. ____ .. _______ ...... ____ .. _ _ __ 386 

Panama conglomerate . _. ____ .... __________ . _____ . _____ . ___ ...... 297 Pictured Cliff sandstone .... _______ .. __ .. __ ...... __ ......... __ .. _ 660 

Paonia shale._ ........••. _ •. _. _ .. _____ . ___ ..... _ . _______ .. _. __ . . . 671 Pierce limestone __ .... __ •... __ .• __ .. ____ . ____________ . ___ ._______ 168 

Pardee, J. T., acknowledgments to. ________ ._. _______ .... ___ ..... 48,58 Pierre shale •... __ ............ __ 663,665,673,674,681,685,691,693,695-697 

Parian group------------ .. __ ------ ...... ___ ... ___ . ______ ..... ___ 344 Pigeon slate ...... ---- .. --- .. __ .... ____ .... _____ .. ______ .. _. _____ 94--95 

See also Older Parian; Newer Parian. Pilgrim limestone .. -- ......... __ . ____ .. _ .... _____ ... ____ .. _ _ _ _ _ 128, 130 

Paris shale ... _ .....• __ . _. _____ .. ___________ .. _________ . _____ . _. _. 458 Pinkerton sandstone ....... __ .. __ ..... ___ . ______ ...... ____ .. __ 418--419 

Park City formation_ .. _._. ________________ ._ .... __________ 379--380,382 Pinole formation ......... __ ........... _ .... __ .. __ ._ ........ __ .... 816 

Parks, W. A., acknowledgments to ... _______ --. __________________ 48,60 Pioche formation ... -- __ ... __ .. __ .• _ .... __ . ____ . _. __ .. _____ .. _ _ _ _ 107 

cited ............ ____ . __ . __ .. ___________ ... ___ ... _____ ... __ ._. 336 Piqua limestone ............ __ .. _ .... __ ... __ .. ___ .. _ ............ _ 458 

publication by .•..... _ .. __ ._. __ ._. ____ ... ___________ . ___ ... _ 857 Pirsson, L. V ., acknowledgments to .. _ .. _ .. __ .. _. __ ..... ___ .. __ .. 49,58 

Park shale ....... _ ..... __ .... ___ . ___ . _____ ..... __ . ____________ .. _ 128 Piscataway marL-- .... --- .... __ .. ---- ... ________ ..... ____ .... 746,747 

Parkville shale_------- _______ ... ·--------.-----_________________ 458 Pishel, M.A., acknowledgments to ... _________________________ 49,.08,59 

Parkwood formation .. ________ . ________ .... __ ._. ____ .. _____ . ___ 403--405 Pitkin limestone .. ---- ......... _ ..... ____ ... ___ . _______ . ___ 411,412,458 

Parma formation---- ___ ...... _____ ·---- ___ ----- ___ . _______ 420,423,468 Pitt formation ...... -- .. --- .... __ .. ______ .... __ ... _. __ . __ ._ 374,519--520 

Parry Archipelago, geology of. ... _. ___ .. ___ ... ___ .. _____ 12,355,399,547 Pittsburg limestone, coal, etc ............... _ .. _ ..... __ .... _ 436,437,439 

Parsons limestone ............ _ ............... __ ........ ____ .... _ 458 Pittsburg Reds .................... __ .. __ .. _____ ..... _ .. _____ .. __ 436 

Pasayten formation._ ....... __ ........ __ ...... _______ . __ .. _ .. _ .. _ 624 Placentia formation ......... _ .•. __ .... ____ . ______ ._______________ 145 

Pascagoula formation .. _ ......... _ .... _ ........... ___ .___ 804 Platt, Franklin, cited ....... ____ ....... _ .. ___ .. ____ -- .. --_ .... _ 434,436 

Paskapoo series ................. __ ...... __ ..... ______ .. 696,697, 78i-782 publication by.-- ............ _ ..... ___ . ____________ . ___ ._____ 857 

Paspotansa greensand ............ _ ... __ .. _ ...... __ .. _____ .. _ .. 746,747 Platte shale .. -- ... ---- __ -........... __ ...... _ .... ___________ .. ___ 458 

Patapsco formation .......... _ ........... _ ...... ___ . _____ ...... 610--613 Platteville limestone .... ----- .. __ .. -- ..... -_____ .. _ 176,180,181-182,195 

Patoot series ....... _ .. _ .................. __ .... _ .... _____ .... _ 705,838 Plattsmouth shale-- .. __ ... __ .. _____ ......... ___ ... _ ...... _______ 458 

Patterns, use of, in mapping ... -. ___ .. _ ... _.-._._ ... ________ .. 23,29-30 Pleasanton shale ..... ___ ...... __ .. __ . __ ... ______ .. _ 457,458,464, 46/Y-466 

Patuxent formation. ___ .... ___ .... __ . ___ .. _ ... _________ 606,610,613,655 Pliocene series, content of. .... __ ....... _ ......... _ .. __ . __ .. _ .. __ . 9 

Pawhuska formation __ .. __ .. ___ .. __ ... __ ....... _ .. __ ..... _ .. __ 461,464 distribution of. ... __ .... __ .......... _ .. _ . _ .. ___ ...... __ .... __ 9 

Pawnee limestone .. _ ........... _ .............. _. __ . ____ ... _ 457,458,463 representation of, on map .............. ___ ._ .. ___ .. _ .. _ ...... _ 91 794 

Pawpaw formation ............. ___ .. ___ .. _.-------_ .. __ .. __ ..... 604 See also Later Tertiary; Marine Pliocene. 

Pawtucket shale .... __ ... _ ......... __ ..... _ ... ___ ... _____ ._...... 469 Plum Point marL----. __ .... __ ... _ .......... __ .... _ ... _ .. ____ .. 7461 747 

Payette formation .. ______ .. _ .. _ .. __ .. _ .. _ .... __________ .. _ .. _... 824 Pocahontas formation. __ .... ______ . __ . __ . _______ ....... 445,446,449--450 

Payne sandstone. __ ... ____ . ________________ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 464 Pocono sandstone .... ___ . _____ . __ .. ____________ 286,294,408,417--420,430 

Peace River, geology on ..... __ .. _ .. __ .. ____ ... _ ... _________ 541,796,835 PointauxBarquessandstone. _. __ . __ ... _____ . ___ ... __ . _ .... _ _ _ _ _ _ 422 

I'eace River sandstone ............ _ ...... _ ........... __ ...... __ 699-700 Point Pleasant formation.-._. ____ .... _____ . ____ ._. ___ ._ .. ______ 166-166 

Peale, A. C., acknowledgments to .. __ . ___ ..... 49,58 Poison Canyon formation ... _______ .. _ .. _____ .. _ .. _ .. _. _. ____ . _ 758--759 

cited .. _ ...... __ .... _. __ .... - ___ 319--321,324,482,491,528,529,558,560 Polk Bayou limestone .... __ . ___ .... _ .. _ ... ____ .... __ . __ ._ ... _ .. __ 169 

publications by __ .. ____ ....... _______ ..... __ .. ____ .. ___ 386,833,857 Polk Creek shale .. --- ___ ... __ ........... _ .. __ .. __ ._... ____ 160--162 

I'eale, A. C., and Scudder, S. H., cited ............... ___ ... __ .... 759 Pond ville group .... -- ..... ___ ........ __ .. ______ .. _... 469 

Peedee formation .... _. __ ....... _ ......... - 11,611-614, fl37, 655,658--660 Poole, H. S., acknowledgments to ........ ________ ._. ____ . _ 49,60 

Peel River, geology of. .. __ ............ _ ............ _ .. _ 269,340,798,837 Popo Agie formation ...... ___ .. _ ........ : .. _ .. _ ..... ____ ... 516,530,531 

See also Mackenzie Valley. Porcupine Hills formation ................... _ .... ____ .. __ .. 693,695,782 

Pelbam limestone .... _ ... _ .................................... 164--165 Porcupine River basin, authorities on ..... ____ . ___ ._. ___ ..... ___ . 61,395 

Pelican formation ___ .... _ ................. __ ............ _ ..... 699--700 geology of ..... -----.--.- __ .... -- .. -- .. _______ -......... 355,395---396 

Pendleton sandstone .... _ .. _ .......... __ .. __ ........ __ ........ __ 317 publications on ... __ . __ .... _ ........ ___ ...... _ ............ __ . 44,47 

.Peninsular limestone ... _ .... _ .. _ .................... ____ ... _.... 740 See also Yukon-Tanana; Yukon-Porcupine; MacKenzie 

Pennington shale_. __ ........... ___ ..................... __ . 403-406,418 Valley. 
INDEX. 887 

Page. 

Portage formation ..•.............................. 291,293,297,305,307 

Port Austin sandstone........................................... 422 

Port Clarence limestone .......................................• 222, 265 

Porters Creek clay ....................................... _ . . . . . 732-733 

Port Ewen beds .......................... _ ... __ .. __ . __ .... 295,297,299 

Port Hudson formation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 806 

Portland group.............................. 137,138,553-554 

Porto Rico (E-19), authorities on......... . ...... 348,801,803 

geology of. .................................. 13,342,348,794,801-803 

See also West Indies. 

Porus formation ................................................ . 800 

Post-Cambrian intrusive rocks. See Intrusive rocks (post-Cambrian). 

Potapacoclay...................................... . ........ 746-747 

Poteau group .... _ ....... _._ ..... _._._ ... _........... 458 

Potem formation ........... _ .. _. _ ........ _. . . . . . . . 561 

Potomac group. __ ..... __ 00 •••••• _................... • ••••• 11,579,610 

Potomac marble ........................ _._...... 524 

Potosi group .... _ ......... _._ ......... _.............. 104 

Potsdam sandstone. 118-119,120-124,130,145,149-153,184,186,196,200-201 

Pottawatomie formation .... _ .... _ .......... _.. . . . . . . . . . . . . . . . . . . 458 

Pottsville formation ••. _ ..... _ . _ .... _ ......... __ . __ . _ .... ____ . _ _ 12, 

404, 413, 420, 430-433' 439-442' 444-452' 458, 466-468 

Powell, J. W., acknowledgments to ... ___ ... _. 00 _ ••• ___ • 49,56,57, 59,60 

cited ..... __ ........ __ ... _ _ _ ... ____ .. _ _ _ _ ... ___ 558,560 

publication by._. ___ ..... ____ ....... __ ._ 857 

Poxino Island shale ................ -·-· ..... _ ..... _ . __ . 238,241 

Prairie du Chien group .. __ .. _._._ ..... __ . __ ... _ 118,120,180 

Pratt, J. H.,acknowledgmentsto........... ···--····---· 49,58 

Pratt coal. ......... _____ .................................. ___ 454 

Pre-Cambrian system, areas of, list of. .... __ .... -.. 62, 64--{)5 

areasof,mapshowing. __ ...... __ ..... _ _ _ _ ___ .... ___ .... _ _ 63 

authorities on ........................... __ .... _____ .. . . 62 

classification of ... _ ....... _ ..... __ .... . 68 

conference on .. ____ ............... __ .... _ ...... _. _ ... _.. . . 63-70 

See also Late Pre-Cambrian; Earlier Pre-Cambrian; Undifferentiated pre-Cambrian; Intrusive rocks (pre-Cambrian); Pre-Cambrian(?) gneisses, schists, and metamorphosed sediments. 

Pre-Cambrian(?) gneisses, schists, and metamorphosed sediments, 

classification of .. _ ..... __ .............. _ ........ ___ .. _ 67 

content of. ..... _ ....... __ ...................... _ . _ ........ __ . 15 

distribution of.. ..... __ ._ ..... ___ ......... _ ... ___ 15,64 

representation of, on map ...... ____ ._ ... ___ ._ ... _ 15,16 

Price sandstone ....................•............... _ 287 

Prince Edward Island, geology of. .. __ ...... ___ .. _______ .... 12,498-499 

Prince William Sound, authorities on .. ____ ..... __ ....... ____ 61 

publications on .................. __ . 41, 42,50,52 

Prindle, L. M., acknowledgments to ...... __ ._.__ _ _____ 49,61 

cited................ 703,790-791 

publications by, list of....................... . .. . . . . . . . . . 857 

Prindle, L. M., and Brooks, A. H., cited....... 221 

Prindle, L. M., and Hess, F. L., cited.. 703 

publication by.................. 857 

Prospect formation........................ 145 

Prospect Mountain formation.................................... 107 

Prosser, C. S., acknowledgments to............... . .... 49,57 

cited ............... 233-234,239,246,274-275,312-313,315,414,486-487 

publications by .................................... 187,240,286,857 

Prosser, C. S., and Cumings, E. R., publication by........... 857 

Proterozoic rocks, subdivision of..... . .... _ ..... _ 67 

Proyidence sand.................................... . .. 655,657 

Puebla (E-F 14), authorities on........ . ............. 519,551 

geology of.......... . . . . . . . . . . . 549,551,590 

Sec also Mexico. 

Puente formation................................... 818 

Puerco formation ............................... 10,661,706,756-758,778 

Puget group ....••.•........... _ ... 10,706,778-780 

Puget Sound, geology at..... . . . . . . . . . . . . . . . 10.778-780 

Pugh, G. T., publication by.......... . . . ... .. ... . 857 

Pugh formation..................................... 444 

Pulaski formation.............................. . . . 180,779 

Pulliam formation................................ 641 

Pumpelly, Raphael, acknowledgments to .... 

cited ...... . 

publication by .............. . 

Purdue, A. H., acknowledgments to ........... · 

cited... . .............. . 

publication by ......•••................. 

49,58 

194 

857 

.. 49,56 

160-164,458,459 

857 

Page. 

Purdue, A. H., and Adams, G. I., publication by................ 857 

Purisima formation ........................................ 753,815,818 

Purslane sandstone ............................................ 418, 419 

Put-in-Bay dolomite ..........................•.•••••.......... 247,248 

Q. 

Quadrant formation........... . ............ 381-382,386,387,621 

Quartermaster formation .................................. 478,487,489 

Quaternary system, content of..... 9 

distribution of. . . • . . . . . . 9 

representation of, on map ...... . 

Quebec (M-N 17-21), authorities on..... . ... 60-61,250,423 

geology of ....... 14, 16. 62. M, 65, 130-1:34,225,250,269,325,401,423-424 

publications on............. 30-33,35,38-39,42-49,51,53-56 

Quebec group.................................................... 131-

132, 148, 153, 192,202, 204,206, 254-255 

Queen Charlotte formation. . . . . . . . . . . . . 11, 542, 579,628-629, 630 

Queen Charlotte Island, authorities on ......... 350,351,539,541,628,630 

geology of. ..•...... 342,350-351,500,537,539-542,579, 628--{)30, 796,834 

See also Arctic coast of Canada. 

Queen City formation........ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 726 

Queretaro, geology of........ 590 

Quinnimont shale................ . . . . . . . . . . . . . . . . . . . . . . .. . . . . . 445, 446 

Quitman Mountains, geology of.... . ...... 579,594-595 

Quotations, use of............................................... 5 

R. 

Raisin River dolomite ......................................... 247,248 

Raleigh sandstone.................................. 445,446,449-450 

Ralston group............................. . .... 461,464-465 

Rampart group................................... 338 

Rancocas group ................................................ 609--{)12 

Random formation........................................ 14, 16,142 

Ransome, F. L., acknowledgments to ......................... 49,56,57 

cited.............................. . ... 72,74-75,271,592-593,820 

publications by, list of....................................... 857 

Ransome, F. L., and Turner, H. W., cited .............. _ ..... __ 555 

publication by............................................... 861 

Raritan formation ....................... 11,609-610,611-613,637,682,684 

Rattlesnake formation........................................... 829 

Raymond, P. E., cited ............................. 188,320,323-324,437 

publications by, list of....................................... 857 

Reagan, A. B., acknowledgments to ............................. 49,59 

cited ........................................ 81,228,272-273,361,573 

publications by, list of....................................... 858 

Reagan sandstone ............................................... 82-84 

Red bank sand.. . . . . . . . . . . . . . . . . . . .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . 609 

Red Beds ....................... 12,363,369,481-482,490-492,516-517,679 

Red Bluff formation ........................................... 487,739 

Red Lion formation ........................................... 129-130 

Red Lodge field, ¥ont., geology of............... . ........... 776-777 

Redstone limestone, etc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 439 

Redwalllimestone ................................. 284, 357, 361, 366-367 

Relief quartzite.................................................. 364 

ltenfroes marl.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . 657 

Reynosa formation .................. __ ._ ....... _ . ... __ ... _ .. _ _ 648 

Rhode Island (K-19), authorities on ............................ 59,469 

geology of. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64, 425, 469-472 

publications on ............................... 32, 34, 39, 40, 51, 52,56 

See a/.,o Atlantic coast; New England. 

Rhode Island Coal Measures.... . . . . . .... . .. . . .. 469 

Richards, R. W., acknowledgments to.... . ....... 49,58,59,60 

publications by................... . ........ 776,858 

Richards, R. W., and Gale, II. s., publication by..... 849 

Richardson, G. B., acknowledgments to. _____ ._. 49,.16, 58,59, 61 

cited ..................... 75-77, 158,228,358-360,363,474-475,597-598 

publications by....................... . ................. 692,858 

Richardson, James, acknowledgments to. . ............ 49-50,60 

publication by........................ 858 

Richmond Basin, Va., geology of......... . ..... 500,518-519 

Richmond formation......................................... . ..... 13, 

166-168, 172, 191, 195, 196, 217, 228-229, 640, 642, 717-718 

Richmond group................................. . ..... 166-168.195 

Richmond-Maquoketa group........................... · 171 

Rico formation............................... 371 

Ridley limestone............................. . . .. . . . . . . . . . . . . . . . 168 

Ries, Heinrich, cited............................................. 192 

publications by.. . . . . ................................. 238,858 

Riga schist...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .. . . . . .. . . . . . . . . 194 
888 INDEX. 

Page. 

Ripley formation .................... 11,612,614,637,653,654-660,732-733 

River Quarry beds............................................... 165 

Riversdale formation ................................... 33(}-331, 355, 386 

Roan Plateau, Colo., geology of. ........................... 706,759--760 

Roaring Creek sandstone.. . . . . . . . . . . .. . .. . .. . . .. . . .. .. . .. . . . . . .. 443 

Robb, Charles, acknowledgments to ............................. 50,60 

Robinson, II. H., acknowledgments to ........................... 5G,57 

Robinson formation .................................... 364,376,520--521 

Rochesler shales .... _. __ ............................... __ ...... 237,245 

Rockcastle conglomerate ................................... 448,451,452 

Rockford limestone............ __ .................... 409,412 

Rockmont slate .. _ .. _ ......... _____ ....... _ ....... _ .......... _... 164 

Rockwell formation._ ........ _ .. ____ ... _ .. _ _ ............. ___ . 418,419 

Rockwood formation ... _ .. _.. _. _ ... 164,23(}-232,238,287 

Rocky Mountains, geology of. ...... _... 10, 11, 12, 13, 14, 15, 17,637 

Rocky Mountains of Canada, authorities on . _____ ..... _. _....... 154, 

207,208,258,333,355,387,388--392,624 

geology of. ....... ________ .... _._. __ ....................... 154,156, 

207-208,225,258,269,333,387-388,579,624-625,639,693--694 

Rocky Woods oonglomerate.............................. .... .. .. 469 

Rogers, H. D., publications by ........ _ ............... _ ........ 433,858 

Rogers, W. B., acknowledgments to .............................. 50,59 

cited ................................................... 115,326,418 

publications by .................. _ ....... __ ................ 174,858 

Rogersville shale ........ _ . _ ...... __ ............ _ ....... __ . . . . . . . . 92-93 

Rollins sandstone .................................... _. __ .. _..... 671 

Rome formation ........................................ _ .. 85,89--91,93 

Rominger, C., cited ........... _. ____ ......... __ ................ 194,245 

publication by ............. __ .............. _ ........... _..... 858 

Ronmey shale ......................................... __ ... 275,286,287 

Rondout formation ......... _._ ............................ 239,241,245 

Rosiclare sandstone ............................................ 409, 413 

Roslyn formation................................................ 774 

Rotten limestone. See Selma chalk. 

Roubidoux formation............................................ 104 

Roxbury conglomerate ......... _ ............................... 115,470 

Ruby formation .............................. _._................ 760 

Ruedemann, Rudolph, acknowledgments to ..................... 50,58 

cited ...................... __ ............................... 189--191 

publications by, list of.. ........ _ .......... _ .......... _...... 858 

Ruedemann, R., and Clarke, J. M., publication by............... 844 

Ruffin, Edmund, publication by ....................... _ ........ _ 858 

Russell, I. C., acknowledgments to ..... _ ................ 50,57, 58, 59,61 

cited ................................. _ . .. . .. . . . 623--624, 825, 83(}-831 

publications by .............. _ .. __ ........................ _ 532,858 

Russell formation ....................................... __ ....... 94 

Russellville shale ............................... _................ 458 

Rustler formation .......................................... 360,474-475 

Rutledge limestone ..................................... _ ........ 92-93 

Rysedorph conglomerate ....................................... 184,190 

s. Sabinas formation .. .. . .. .. .. .. .. .. .. .. .. .. .. • .. .. .. .. .. .. .. .. .. . 649 

Sabine formation. See Wilcox formation. 

Sacramento formation . .. .. . .. .. .. .. .. .. .. .. . .. .. .. . . . .. . .. .. .. .. 374 

Safford, J. M., acknowledgments to .............................. 50,59 

cited ....................................... 276,277-278,401,418,728 

publications by ........... _ ............................ 173.653,858 

Safford, J. M., and Killebrew, J. B., publication by .. ... .. . .. .. . 858 

Sage Creek formation ....... _.................... . .. .. . 775--776, 833-834 

Saginaw formation ............................................ 420, 468 

Sailor Canyon formation .... _ .. .. .. .. .. .. . .. .. .. .. .. .. .. .. . .. .. 522, 555 

St. Charles formation .. _......................................... 106 

St. Croix formation ..................... _ ...................... 124, 145 

Ste. Genevieve limestone .............................. 409,411,413,458 

St. Elias Range, geology along._ ........................... 355,394-395 

Ste. Marie formation .................. __ ......................... 198 

St. Helens Island, geology of. .. _ ...................... _ .... 269,324-325 

St. Joe limestone .............................................. 411,458 

St. John group ..................................... 137-139, 142,145,147 

St. Lawrence formation .. .. .. . .. .. . .. .. .. .. .. .. . . .. .. .. .. .. . .. .. . 118 

St. Lawrence Island, authorities on .... _ .. .. .. .. .. .. . .. .. .. . .. .. 61 

publications on ............. _........................ ... ..... 35 

St. Lawrence Valley, authorities on .... __ ...................... 13(}-134 

geology of. ...................................... 72, 13(}-134, 19&-206 

St. Louis limestone ........... _ ... 401,403,406,408,411,413,418.420,458 

St. Marys formation .. . .. . . ~ .............................. 74&-749 

St. Marys River formation ................................. 693,695, 782 

St. Maurice formation ......................................... 726, 727 

Page. 

St. Peter sandstone .........•... _ .......... 104,118, 169, 176,180, 194,249 

St. Piran formation ............ _................................. 154 

St. Stephens limestone ........................................ 738,739 

Salem limestone ....... _ ...................... __ . _............... 409 

Salina shale .................. __ ............ ___ .... 239,241,245,246,248 

Salisbury, R. D., acknowledgments to........................... 58 

publication by............. ................................. 85~ 

Salisbmy, R. D., and Chamberlin, •r. c., cited ..... 242,408,411,412,414 

Saltsburg sandstone .......... __ .................... _ ...... __ .... 436 

Salmon formation .......... _ ............... _ .. _ ...... _ .. _ 242 

Salmon River shale ............ _ .... __ .... _ ............. _ ... _ ... _ 184 

Salmon Trout limestone .......... _ .. _ .......... _ .. _ 339 

Salter,J. W.,cited ............................................. 222,261 

publications by ........ _ ...... _ ...... _ .. ___ ............. ___ 265,858 

Salterain y Legarra, Pedro, acknowledgments to .... ____ .. _ 50.56 

Saluda formation ........................... _...... 172 

San Andreas limestone .......... _ .... _ .... _.. .. 363 

Sandia formation ......................... __ .. _ ......... _ 362 

San Diego formation ...... _ .......... _ .. _ ........... _ .. _ 818 

Sandsuck shale ......................... _ ....................... 91-92 

Sanford, Samuel, acknowledgments to .... _ .... _ _ ___ .... __ . _ 50,57 

publication by ................................... _ ...... _.... 858 

San Francisco sandstone ........................... _ ............ _ 555 

Sau Juan basin, geology of. ............. __ .......... _ ..... _ 70r, 755--757 

San Lorenzo formation .... _ ........ _.. .. _ .. _ ............. 753,815,818 

San Luis formation .. _ .............. _ .... _ ...................... _ 6C8 

San Luis Potosi (F-14), authorities on .......................... 551.591 

geology of. ................................. 549,551-552,579,590,591 

See also Mexico. 

San Miguel beds ............ _ ................ _ .. _.............. 649 

San Pablo formation ........................ _ .......... 723,815,816,818 

San Pedro formation ......... _ .. _ ..... _ ......... _ .... ___ .. .. . . 815, 818 

Santa Clara formation .............. _ ..... _ .... _ ...... _.......... 818 

Santa llfargarita formation __ .. _ ............... __ .......... _ 754,817.818 

Santa Rosa formation .... _ ............... __ .. __ .... _._ .......... 12,425 

Santee marl .......................... __ ........ _ ............... _ 737 

Santo Domingo (E 18-19), authorities on ..... _ .. _ .. 345,346,642,801,803 

geology of ................ 13, 16,342,345-347,637,642-643,794,801-803 

See also West Indies. 

Sapper, Carl, acknowledgments to ............................... 50,56 

cited .... __ ..... 345,355,357,425, 50(}-502, 503-504,549,585--586,721,798 

publications by ......................................... _ .. 427,858 

Sapulpa group .......... _ ............... _ ................. _ .... 461,464 

Saratogan series ................................... _ .... _ .... 75, 104,124 

Sardeson, F. W., cited ............... _ .... _ ..................... _ 120 

publications by, list of ................ _._ ............... _._.. 858 

Sardeson, F. W., and Hall, C. W., publications by ...... _ ...... 169,851 

Saskatchewan (M-0 12-13), authorities on ...... _ 61,262,336.695--697,834 

geology of. ........... 62, 64,225,261-262,269,336,629,695--698,796,834 

publications on ............................... 33,37--38,46--47,51,53 

Savage, T. E., acknowledgments to .............................. 50.57 

cited ............................................... 171,236,279--282 

publications by ...................... _ .............. _ .. 278,858-859 

Savage formation .. .. .. .. .. . . . .. .. .. . .. . .. .. .. .. .. .. . .. .. .. . .. . 443-444 

Savanna formation . .. .. .. . .. .. .. .. .. . .. . . . . .. . .. . .. . .. .. .. . .. 458,467 

Sawkins, J. G., acknowledgments to ...... _ ........ _ .... _........ 56 

cited......................................................... 717 

Sawkins, J. G., and Wall, G. P., cited .............. 344-345,584,714-716 

publication by .. _ ........................... _ .... _.......... 863 

Say, Thomas, publication by ................ _ .... _.............. 859 

Sayles, R. W .. and La Forge, L., cited .... _ ........ _............. 470 

publication by ....... _ ............................... __ ...... 859 

Scale of map, restrictions imposed by ..................... _....... 7-8 

selection of. ........................... _ ............. _........ 8 

Scalia, S., and Burckhardt, C., cited ....... _ .. _ .... _ ........... 504-505 

publication by ...................... _ ........ _........ .. .. .. 843 

Schagticoke shale ............ _ ... _ .............................. _ 191 

Schaller, W. T.,cited............................................ 360 

Schei, P., cited .. : .............................. 155,26&-268,400,548,839 

publications by ............................................ 341,859 

Schoharie grit ................................ _ ............ ___ 297,300 

Schrader, F. C., acknowledgments to ...... _ .. _ ...... 50,56,57,58. 61,636 

cited ....................... _ ... 340,354,399,458,636,702,792-793,838 

publications by ....................... _ ................. _ .. 793,859 

Schrader, F. C., and Spencer, A. C., cited .................. 394,543-544 

publication by.............................................. 859 

Schuchert, Charles, acknowledgments to ........ _................ 20 

cited ................................... __ ....... _ ......... 223-224, 

227,254,275,276,288,290,298--299, 324-" :9,495 
INDEX. 889 

Page. 

Schuchert, Charles, publications by ........... 171,265,275,293,334,859 

Schuchert, C., and Clarke, J. M., publication by.................. 844 

Schuchert, C., and Diller, J. S., publication by.................. 847 

Schuchert, C., and Ulrich, E. 0., cited........................... 187 

publication by . . . . . . . . .. .. . . . .. . .. . . . .. . . . . . . . . . . . . . 862 

Schuchert, C., and White, D., cited. . . . . . .. . . . . . . . . . . . . 704-70.5, 838-839 

Schultz, A. R., acknowledgments to ......................... 50-51,60 

cited ................................... 494-495,529,674-675,677,765 

publication by . . .. . .. .. .. . . . . . . . . . . .. . . . . .. . . . . . .. . . .. . . . . .. 859 

Scope of paper............... . . .. . . . .. .. . . . . . .. . . . . . . .. . . .. . .. . 5-6 

Scott, W. B., cited... .. . . . . . . . . . .. . . .. . . . . . .. . . . . . . . . . . . . . . 775-776, 834 

publications by, list of....................................... 859 

Scott shale .. .. .. .. .. .. .. .. . . .. . . .. . .. . . . . . . . . . . . . . . . . . . . . .. . . . . . 451 

Scranton shale .. .. .. .. .. . .. . .. .. . .. . .. . . .. .. .. .. . . . . . . . . . .. . .. . 458, 465 

Scudder, S. H., cited............................................. 437 

publications by. • .. . .. .. . . . . .. .. . .. .. .. .. .. . . . . . . . . .. . .. .. . 759, 859 

Scudder, S. H., and Peale, A. C., cited........................... 759 

Seaman, A. E., and Lane, A. C., publication by................. 854 

Sebastian group................................................. 458 

Sedimentary rocks, representation of... .. . . .. . .. . . . . . . .. .. . . . . . . . 39 

Seekonk conglomerate .. .. .. .. .. .. .. .. . .. . .. . . . .. . .. . . . . . . .. .. . . . 469 

Seely, H. M., and Brainard, E., cited .......................... 125-126 

publication by .. .. .. . . . • . .. . . . . . . .. . . . . . . . .. . . . . . .. .. . . . . . . . 843 

Selden, H. S., aid of.............................................. 21 

Sellards, E. H., acknowledgments to............. .. ........... 51,55 

cited ....................................................... 741-744 

Sellersburg beds ........................................... 275,317-318 

Selma chalk ....................................... 612,614, 653-C56, 660 

Selwyn, A. R. C., acknowledgments to ........................ 51,60, 61 

cited ............................................... 625,627,C98-C99 

publications by ............................................ 203,859 

Seminole conglomerate .. .. .. .. .. . .. . .. . .. . .. . . .. .. . . . . . . 458 

Seneca group............................ .. . .. .. .. .. .. .. .. .. .. .. . 297 

Senora formation . .. .. .. .. . . .. . .. . . .. . . .. .. . . . .. . .. . . .. 458,462-403 

Sentinel Butte field, geology of......... . ...... 700,777-778 

Sequoyah formation............................. 449 

Sera! conglomerate . .. .. .. . . .. . .. . . . . . . . . . . . . . ............. 433,439 

Sespe formation ............................................... 814,818 

Severy shale .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 458, 4Ei7 

Sevier shale.................................. .. ......... 173-174 

Sewanee conglomerate ................................. 448,449,451-452 

Seward Peninsula, authorities on .................... 61,222,265,395,791 

geology of .... 64, 72,155,156,222,225,265-266,269,338,354,355,395,791 

publications on.................................. . .. 34,35,48,52 

Sewell formation .......................................... 445, 44E\-447 

Sewickley formation .. .. .. .. . . . . . . . .. .. . .. . . . .. .. .. . . ...... 438,442 

Shade, definition of.......... .. .. .. .. .. . 22 

Shady limestone .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ... 95, 96,97 

Shakopee dolomite .. .. .. .. .. .. .. . .. . . . . . .. .. . . . . . .. 118 

Shaler, M. K., acknowledgments to..... . ...... 51,57 

publication by . . . . .. .. .. .. .. .. . .. .. .. .. .. . 859 

Shaler, N. S., acknowledgments to...... .. ....... 51,58,59 

cited................................ 275,470,682-683,756 

publications by, list of........................ 859 

Shaler, N. S., and Woodworth, J. B., cited.... .. ....... 518-519 

publication by .. .. .. . . .. . .. .. .. .. .. .. .. . 859 

Shaler, N. S., and otherR, publication by............. 859 

Shark River marl ......................................... 746,748,749 

Sharon conglomerate .. . .. .. . . . .. .. .. . .. . .. . . . . . . . . .. . . . . . . . .. . . . 434 

Sharpsville sandstone ......................................... 414, 419 

Shasta series......................................... 11.575,615 

Shattuck, G. B., acknowledgments to ......................... 51,57,59 

Shattuck, G. B., and Miller, B. L., publication by............... 859 

Shattuc}:, G. B., and others, publication by...................... 859 

Shaw, E. W., acknowledgments to............. . ..... 51,59,60 

cited ................................................... 690-691,769 

puhlication by.................................. 859 

Shaw, E. W., and Munn, M. J., publication by................... 859 

Shawangunk conglomerate .................................... 238,240 

Shawnee formation.............................................. 458 

Shenandoah group.................................. 109-113,173-175 

Shenango shale.............................. 40E\-407, 415,418 

Shepard, E. M., cited....................... 733,734 

publication by.................. 8S9 

Sherbrooke formation .. .. . . . .. .. . . .. .. . . . . .. . .. . . . . . . . .. . . . . 154 

Sherburne shale .................................... . 

Sheridan sandstone ............................. .. 

297' 304, 312 

328 

Sherzer, W. H., cited ............................................ . 246 

Page. 

Sherzer, W. H., and Grabau, A. W., cited........................ 249 

pul:;lications by. . . .. . . . . . .. . . . . . . .. . .. .. .. 81i0, 860 

Shimer, H. W., cited.............. . ............ 115-116 

publication by........................ .. . . . .. .. . .. . . .. . 860 

Shimer, II. W ., and Grabau, A. W., cited........................ 293 

publication by............................................... 860 

Shimer gypsum ............................................... 487-488 

Shinarump conglomerate. .. . . . . .. . . . .. . . . 484, 513-SlS, 556, 558 

Shoal Creek limestone..... .. .................. 467-468 

Shoal River marl................ . ...................... 743-744 

Shoshone group.............. . .................... 10, 20,706,762 

Shumard, B. F.,cited........... . ..................... 77,170,408 

Siebenthal, C. E., acknowledgments to ..................... 51,57,58,60 

Siebenthal, C. E., and Darton, N.H., publication by............. 846 

Siehenthal, C. E., and Hopkins, T. C., publications by ......... 413,852 

Siebert lake beds.. .. .. . .. . .. .. . . .. .. .. .. .. .. . . . .. .. .. .. . .. .. .. . . 819 

Sierra de Catorce, Mexico, geology of. ...................... 549,551-5.52 

Sierra de Mazapil, geology of. .................. 549,552-.554,579,592,644 

Sierra group .. . .. . .. .. .. . .. . .. . . . .. . . . . .. .. . .. . . .. .. .. . .. .. 346, 642-643 

Sierra Nevada, geology of. ............................. 355, 363-364, 555 

Sievers, Wilhelm, acknowledgments to ........................... 51,56 

cited ....................................... 342,344,583-584,708-709 

publication by .. . .. . .. .. .. .. .. .. . .. .. .. .. . .. .. .. .. .. .. .. .. . .. 860 

Signal Hill conglomerate......................................... 142 

Siliceousgroup................................................... 418 

Sillery formation ........................................... 197,203,204 

Silliman's Fossil Mount, geology at ...•......•................. 223-224 

Silurian system, content of. ..................................... 13,225 

distribution of..... .. .. . .. . . . . .. .. .. . .. .. .. .. . .. .. .. .. . .. .. . . 13,225 

details of.. .. . .. .. .. . . . . .. . .. .. .. . .. .. . .. .. .. . . .. .. .. .. .. . 225 

map showing-.................... __ ........ __ .... _........ 226 

representation of, on map ............................. 12,13,17,225 

Silver Creek limestone ......................................... 318-319 

Silver Hill formation ........................................... 128-130 

Similkameen formation .. .. . . . . .. .. .. .. .. .. . . .. .. . .. . .. .. .. .. .. . . 624 

Simonds, F. W., and Branner, J. C., cited........................ 458 

Simpson formation ...................................... , .. .. .. . 159 

Sinclair, W. J ., and Merriam, J. C., publication by.............. 856 

Sioux quartzite.................................................. 15 

Skajit formation................................................. 266 

Skaneateles shale .. .. .. . . .. . .. . .. . . . . . .. . .. . . . . . .. . . . . . .. . .. . .. . . 297 

Skeat,E.G.,cited........................ . ............. 546 

publication by............................................... 860 

Skunnemunk conglomerate...................................... 296 

Sloan, Earle, acknowledgments to ................................ 51,59 

cited ............................... 605,659,732,737,739,806,807,810 

publications by, list of................ . . .. . .. ... . .. . . 860 

Smelt Brook shale .. .. .. .. . . .. . .. .. .. .. . .. . .. .. . . . . . . . .. .. .. .. .. . 386 

Smith, A. D. W., acknowledgments to...... .. .......... 51,59 

publications by ............................................ 439,860 

Smith, C. D., acknowledgments to......... . ......... 51,58 

Smith, C. D., and Collier, A. J., cited....... 777 

Smith, C. D., and Leonard, A. G., cited........ . ....... 777-778 

publication by...... .... .. .. .. . .. .. . .. .. .. .. .. . .. . 854 

Smith, E. A., acknowledgments to ............................... 51,56 

cited................ . .. 88,402,430,654-657,733-734,735-736,738 

publications by ............................................ 173,860 

Smith, E. A., and Johnson, L. C., publication by . . .. . .. . .... .. .. 860 

Smith, E. A., and others, publication by............ 860 

Smith, E. E., acknowledgments to..... . .................. 51,60 

cited......... . ........... 680,767-768 

publication by.......... .. .. .. .. .. . .. .. .. .. .. .. .. . .. 860 

Smith, G. L., publication by.......... . .. .. .. .. . .. 860 

Smith, George Otis, acknowledgments to ............. 21,51-52,57,68,59 

cited........................ .. .. 350,573,774,780 

publications by. . .. . . . . . . .. . .. . . . . .. .. . . . . .. . . . 623. 860 

Smith, G. 0., and Calkins, F. C., publications by, list of......... 860 

Smith, G. 0., anci White, D., cited........ ... ................ 327 

publication by............... .. .. ...... .. ... 860 

Smith, G. 0., and others, cited......... .. .......... 134-135 

publication by. . .. .. .. . . . .. . . .. . .. . . .. .. . . . 860 

Smith, J. H., cited... . .. .. . .. .. ...... . 756 

publication by .. . .. . . .. .. .. .. . .. .. .. . .. .. . .. .. .. .. .. .. .. . 860 

Smith, J.P., acknowledgments to................................ 20 

cited....... 374-376.464,504,519-522,527,528,534,556,617,620-621 

publications by....... . ......... 555,860 

Smith, J.P., and Hyatt, A., cited........ .. ........... 527-528 

publication by.................... .. .. ............. 852 
890 INDEX. 

Smith, P. S., acknowledgments to ...... _ 

cited._._ 

Page. 

52,61 

265 

publication by ................ _._ 860 

Smith, P. S., and Eakin, H. M., cited ...... _ 395 

publication by ............... ____ 860 

Smith, W. H. C., acknowledgments to ... __ 52,60 

Smith, W. S. T., acknowledgments to .... _ 52, 57, 58, 59,60 

Smith, W, S. T., and Ulrich, E. 0., publication by.............. 862 

Smith Point limestone .••...........•................ _._ 142 

Smithwick shale .••••....•....•............ _._ _ _____ . 427.428 

Smoky River shale ............................ _.. .. .. . 699-700 

Snake River valley, geology of .. _._ ... _ _ .... 790,824-825 

Snowbird formation . .. .. .. • .. .. .. .. .. . .. .. .. .. . .. .. . ....... 95,96 

Sockanasset sandstone . • . . . . . . . . .. .. . . .. .. . .. . .. .. .. .. .. 469 

Somber beds ............... _______________ 10,706,762-764 

Somerville formation ................................. _. ___ .... 467-468 

Sonora (G-H 12), authorities on....... _____ ......... 227,593 

geology of. ... ___ ....... ___ . 225, 227, 269, 271, 593-594 

See also Mexico. 

South America, authorities on .... _ 

geology of.. _ _ _ ..... __ .... _ 

publications on ............. _ 

See also Colombia; Venezuela. 

56 

9, 10, 11, 15, 16,637,794 

--------- 42,43,51,54 

Southampton Island, geology ...... ___ .. _. __ . _ ... __ . 221-222 

South Carolina .(I-17), authorities on ..... ___ _ __ . 59,605,654 

geology of ..... __ _ .. 64, 65, 70,579,605-606.613,637,654-660 

publications on................... ___ . 33, 43, 51,52 

See also Atlantic coast. 

South Dakota (K-L 13-14), authorities on .. _ . _. _ ... _....... 59, 

118,496,533,685,691,761-764,769,821-823 

geology of.... __ . _ ..... _. _ ..... 10, 15, 64, 72, 118,474,495-497,500, 

533, 549, 567, G39, 685, 691, 706, 761-7()4, 769-770,794,821-823 

publications on ............ _ ..... 32, 33, 36, 41, 42, 43, 48, 49, 52, 53,54 

See also Great Plains. 

Southeastern Alaska. See Alaska, southeastern. 

Southern Alaska. See Alaska, southern. 

Southgate formation._ _ _............ 172 

Spadra shale ....................... -............ _ _ 458 

Sparagmite formation .............................. _ 147 

Spearfish formation _ ................................ _ .. 492,495-497,533 

Spencer, A. C., acknowledgments to ...... _._ .. 21,52, 56, 57,58, 59,60,61 

cited ..... _. _. _ ....... _. __ .... ___ - __ . ___ .. _. _ ... 367-368 

Spencer, A. C., and Paige, S., cited .............................. 77-80 

Spencer, A. C., and Schrader, F. C., cited ... __ .... __ .... ___ 394,543-544 

publication by .............. -...... -........ _ ....... -..... -.. 859 

Spencer, A. C., and others, publication by .. . .. .. . .. .. . . .. .. .. .. 860 

Spencer, J. W., acknowledgments to ....... -.- .... _ ...... _._ 52, GO 

Spence shale ............................ -....... _................ 106 

Spergenlimestone ..................... -............. __ . 409,411,413,458 

Spokane formation ................................ _. _ .......... _ 128 

Spring Creek limestone .............................. _ .... ___ . .. . 411 

Springfield limestone ...... -.................. -................... 234 

Spurr, J. E., acknowledgments to.-._.- ...... --_ .... _ .... _. 52, 57, 58,61 

cited ........... _. __ .. _ ......... 701-702,750-751,788,792,820,835,836 

publications by ........... _ .......... -............ _ .... 102,236,860 

SquareLakesandstone ......... -............ --- ...... -.... - 328 

Squire, Joseph, cited. __ ......... -.- .. -.... -.--- ........ _ .... _ 455 

Stanley shale ............ _ ................. , .... _ . -.. . .. . . .. . . . 458, 459 

Stanton, T. W., acknowledgments to .......................... 20, 52,61 

rited _. _ .... _ .... __ 505,506.533, 535) 543,545-546,552,554,556,5571 5G5, 

566, 571, 57~, 576, 588,591,593,594-595,607-608,619-620,623, 

6.30, 632-633, 636, 662, 674,685-686,694,752, 762-7C,3, 767-768 

publications by ... __ ............. _.- ... _- .. 570,615, 673, 7G4, 860-861 

Stanton, T. W., and Diller, J. 8., cited ..................... 615,667,070 

publication by __ .... __ ....................... _ .......... _.... S47 

Stanton, T. W., and Hatcher, J. B., publication by............... 861 

Stanton, T. W., and Martin, G. C., cited ........... 541-542,574,631,783 

publication by ............. _ ............. -. _. _ ..... _ .... _. _ 855,861 

Stanton, T. "\Y., and Vaughan, 1\ "\V., cited........ 59G 

publication by ....... _. ____ ...... - 861 

Stanton Jin1estone .......................... -..... _ 458,464 

Star Peak series ............ _........... ___ ...... - 521-522 

Starrs conglomerate ................... _. __ .......... _ .... _ 91 

Stauffer, C. R.,cited..................... ------- 315-317 

publications by, list of. ..... __ ......... _ --- .. .. .. . .. 861 

Stebinger, Eugene, acknowledgments to ....... _ 

Steenstrup, K. J. V., acknowledgments to ............. .. 

Stellarton formation ................................. _._ ........ -

Stephen formation .................... -------- -... --- .. ----.----

52,60 

52,61 

386 

154 

Page, 

Stephenson, L. W., acknowledgments to ............ 21, 52,56, 57, 59,612 

cited ............................... _ .... _ .... _. _ .. _ 605-606, 653--ll60 

publications by ...................... __ ........ _ ........... 611,861 

Stephenson,L, ,V.,andCrider,A. F., cited ...................... 724 

Stephenson, L. W., and Veatch, 0., publication by............... 862 

Stepovak series ............................................. __ .. 782 

Sterrett, D. B., acknowledgments to ........ __ .. _ .......... _ .. 52, 58,59 

Stevens, R. P., publication by.................................. 861 

Stevenson, J. J., cited ... _ .................... _ ... ___ .. 363,406,407,410, 

414-415,417-418,419, 4.3(), 438-439,442,444,449,450,451,452,492-494 

publications by ............... _ ..... _ ... _ ... _ ...... _ ... 433,443,861 

Stewart River region, geology of ....... _ ... __ ... ___ ....... 500,544-545 

See also Yukon Territory. 

Stillwater formation .... _ ........... _ ... _ ... _._.................. 78il 

Stissiug series................................................... 145 

Stockbridge dolomite ................... _ .... _ _ _ ... _ 189,192,193,194 

Stockton coaL. ....................... _ .... _._ ... _._............. 443 

Stockton group .............................. _ ........ 522-524,526--527 

Stone, R. W., acknowledgments to ....... _ ......... _ .... _ .. 52, 58, 59,61 

publications by ....................... _._ .. _. __ ............ 687,861 

Stone, R. W., and Calvert, W. R., cited ... ____ ............... __ 687-690 

publication by ........ _ ................... _ . . . . . .. . .. .. . .. .. . 861 

Stone, R. W., and Mofflt, F. H., cited ..... _ ............ _ ..... _. 785-787 

publication by .................. _ ... __ ._..................... 856 

Stonehouse formation._ ............... _ ........ _ ................. · 251 

Stones River group ................ __ .......... 109,165,168,176--177,217 

Stony Hills formation ..... _ ... _ .. _ ............ _ ........ _........ 487 

Stony Mountain formation. .. ...... __ ............ ••. . .• . .. .. .. . 219 

Stormville sandstone ............ _ .. _ _ _ ...... _ ....... 294,295 

Stose, G. W., acknowledgments to ......................... 21,52,57,59 

cited .. _ ............. _ ..... _ ...... _ ......... 107-111,176--177,418,419 

publications by, list of. .................. _ ....... _ ...... _.... 861 

Stratigraphy, discussion of.................. .. .. .. .. .. .. . 5 

Strawn formation ...... _ _ _ ..... _ ............. , .. .. . .. .. . .. .. . 429 

Stringtown shale ..... _ .............. _..... ____ ........... 160-162 

Stuart shale .......... _ ................. _ . __ .. _ ... _ . .. . . . .. .. . .. . 458 

Stuver series .............. _ ................... _._................ 340 

Sucarnochee clay .... _ ...... _ ................. _ ................ 731,732 

Suess, Edward, publication by .. . .. .. .. . .. .. .. .. .. . .. . • .... . .. . . 861 

Sugar Loaf arkose ....... _ .................... _.................. 532 

Sulphur Springs formation .... _ ................................. - 278 

Sunbury shale ..................................... _ ... 408,414-417,420 

Sundance formation ....................... _ ... _ 11,531,549,567-570,678 

Surficial rocks, representation of.. ......... _ ... _._ .. _............. 29 

Susitna basin, authorities on .................... _._ ... _ 61 

publications on ...................... _ ...... _ ..... _ .... __ . 34, 38,52 

Sutton Mountain, geology of. ............ -............ - 16 

Swartz, C. K., acknowledgments to ....... _ ...... _ ..... _ ...... 53,57,59 

cited ..... ___ ..... _ _ .... _ . _ ..... _ . __ .... _ . _ -. . . . .. . . .. . .. .. 285-286 

Swasey formation ... __ ................. _ ................... _.... 107 

Swank formation .......... _ ........... _ .................... _.... 774 

Swearinger slate ....................................... 374,519-521,561 

Sweetland Creek shale............................ .. .. .. .. .. .. .. . 290 

Sylamore sandstone ..... ___ ..................................... 274 

Sylvania sandstone ...... _ ......... _ .... _ .......... 233,246,247,249,315 

Sylvan shale .... ___ ... -..... -....... -......... -............... 228-229 

Symbols, explanation of.. ........ _ _ ..... _.................. 9-16 

T. 

Tabasco (E 15), geology of.. ...... -----.---- ............ 721-722 

See also Mexico. 

Tachatna series . _ ................ _ ... _ ........ _ ........ _ ...... _ . _ 633 

'raconic system ...... _ .. _ ........... -................. - __ .... _ . 192-194 

Tall', J. A., acknowledgments to ... _ .. _._ .... _._ .. ____ 53,56,57, 58, 59,60 

cited._ _ _ ...... _ .. _ ...... _ ... 82-84,428-429,458,459,462,650 

publications by ......... __ ........ _ .... _ ...... _ ..... _._ .... 777,861 

Taff, J. A., and Brooks, A. H., publication by.................... 861 

Tall', J. A., and Ulrich, E. 0., cited ............ 159-160,228-230,273-274 

Tallahatta buhrstone ................... _ .... _ ......... ___ . . .. . 735, 737 

'raloga formation ........... _ ... _ ................. _ ... -..... ___ .. 487 

Tamana series ................ _ ............... _ 714-715 

Tamaulipas (F-G 14), geology of. ... ___ .... _. __ ..... __ ._._ ..... 590,799 

See also Mexico. 

Tampa formation. __ ........... __ ....... _ ...................... 741,742 

Tanana basin (upper), authorities on ......... _ .. - 61 

publications on ...... __ ........... _ .... _ ....... _ ...... _ 34, 44, 48,50 

See also Yukon-Tanana region. 

Taneum andesite .. __ ............................. -...... _....... 826 
INDEX. 891 

Page. 

Tarr, R. S., acknowledgments to .............................. 53,58, 61 

cited......................................................... 359 

Taylor marl ........ _ ...... _ ................... _ .. __ ... _ ...... _ 650-651 

Taylorsville district, Cal., geology of.. ... _._ _ .... _ .. _. _ .. _ 175,242 

Taylorsville formation ......................... __ .. _ _ _ .. _. _. _.. 242 

Teanawaybasalt........................ -------·-··---- 774 

Tecovas formation ....................... _ .................. __ ... 478 

Tecumseh shale ......................... _ .. _ ..... _ .. _ . _ ... _ ... _ 458, 464 

Tegucigalpa formation ...................... _ ... _ ....... __ ... _... 502 

Tehuacan slate .. .. .. .. .. .. .. . .. . .. .. .. .. .. . .. 588 

Tehuantepec, Isthmus of, geology of.. ... _ _ .. _ 579.588-589 

Sec also Central America. 

Tejon formation ............... 669,751-752,753-754,771-772,815,817,818 

Telkwa River district, B. C., geology of ........ _ ...... _._ .. 579,630-631 

Tellico sandstone ....................................... _ ...... 173---174 

Tellowa formation ............................... _ ........ _ 449 

Temiscaming, Lake, geology of. ......... _ .... _ ................. 196,250 

Temiscouata Lake, geology at._ .. __ .... _ .................... _ .. 252-254 

Tenmile River formation ................................... __ .. _ 469 

Tennessee (I-J 1&-17), authorities on ................... 59, 89, 164, 167, 

168, 173, 174, 231, 232, 234, 235, 275---277,401,402,406,407' 653 

geology of ................ 72, 8!i-98, 156,164-168,173-175,225,230-232, 

2.'l4-235, 238,269,274,275---278,401-407,418, 442-452_, 637,653,655 

publications on ............................ 35,41,42,43,50,53,54,55 

See also Appalachian Mountains. 

Tensleep sandstone ............................ 00 .............. 495,531 

Terra Cotta series ............................................. _ .. 221 

Tertiary system. Sec Earlier Tertiary; Later Tertiary_; Earliest 

Tertiary or latest Cretaceous; Effusive rocks (Tertiary 

or later). 

Teton formation ............................. _ ............ _ ... __ . 534 

Texas (G-I 13-15), authorities on .... _ ........ __ ... _ .... _ ....... _ 59, 75, 

77, 158,227,228, 358-3CJO, 427,428,430,455,474-479, 

506,554,579,594-605,649,650,652,652,723,804,813 

geology of ....................... 11,12,15,64,72,75---80,156,158,225---228, 

355,358---360,425,427-430,455---456,474-479,500, 50&-507, -549, 

554,594-605,637, 64!i-653, 706,723---731, 794, 804-806, 813---814 

publications on ..•.•...•.... _.......... 31, 3&-38, 41-43,48,49,52-54 

See also Great Plains; Mississippi embayment; Gulf coast. 

Thayer shale .... _................................................ 4.58 

Thaynes limestone .......................................... _. 380,494 

Thebes formation .............................................. 170,171 

Theresa dolomite ............................... _ ... _ .. 123---124,184, 186 

Thompson limestone ................................ ___ .. _ .... 561-.563 

Thoroddson, Th., acknowledgments to ........... _ . _. _ ... 53,61 

Threeforks shale ............................. ___ ._ 319-324 

Thunderhead formation ......................................... 94-95 

Thurman sandstone ............................. _ 4.58 

Thurmond formation ................................ _ 446 

Tia Juana, Lower California, geology at ............ _ .. _ ...... _. 794,799 

Tim pas formation ................................... _ .... _ ..... 662---663 

Tint, definition of.._ ......... _ ... _ .... _ ....................... _ 22 

production of.. ............. _ .... _ ... _._ ... _ .. _ .... _ .... _._. 23 

Tippenhauer, L. G., acknowledgments to ........................ 53,.56 

Todd, J. E., acknowledgments to....... 53,57,58,59 

Todos Santos formation .................................. _ 503---504,586 

Tokun formation ....... 00 ... 00 ................ _ 789 

Tombigbee group .................................. __ _ ... 654-657 

Tomlinson shale ...... 00 .. 00 .. 00 ...................... _.......... 458 

Tomstown limestone ................................ _ ..... _ . _ . 109-110 

Tonto group ... _ . _. _ ...... _ ..... _. 72, 81, 89,124,145 

Topatopa formation ........ _ ...................... _ .. _..... 814 

Topeka limestone ............................ 00 ........ _ ••• __ .. 458. 465 

Topography, restrictions imposed by, on geologic mapping....... 8 

Torbrook sandstone .................................... _ ... _.... 252 

Toro formation ......................................... _ ...... 616,668 

Torrance, J. F., acknowledgments to ..... _ ......... _ ............. 53,61 

Torre, Carlos de Ia, acknowledgments to ...... 00 __ ... _ .... _ ••• _ ••• 53,56 

cited ...... _ 00 .. _ .... __ .. 00. _ _ _ __ ... _. _ ....... 00 .... _. 552 

Torre jon formation ............................... 00.00 661, 75&---757, 778 

Tower, G. W.,acknowledgments to ........................... 53,.58,59 

Trail formation.. . .. . .. . . . . . . . .. .. . .. • .. .. .. . .. . .. .. • .. • .. .. .. . . . 561 

Trans-Pecos 'l'exas, geology of. .................................. 75---77 

Traverse formation ........................................ 313,314,317 

Travis Peak formation .................................. 00 598-599, 602 

Trent marl ............................... _ ...... _. oo·........... 748. 

Trenton group ........................................ oo ... 164,168,169-

171,176,183-184,187,189-193,194-195,196,197-202,204,217,223 

Page. 

Triassic system, content of. ........................... 00 00 ... 12,17,500 

distribution of. ................................. 00 .. oo ... 11,17,500 

details of. _ _ _ ...... _ ........................ _ 00 .. 00 • 500-548 

map showing ... oo· ..... __ ................ _ •• 00 ... ___ ••• _. 501 

representation of, on map ................ __ .. __ .. _ ..... _ 11,12,500 

See also Triassic and Jurassic. 

Triassic and Jurassic systems, content oL ... __ ... __ . __ .. ___ . _ 11 

distribution of. ..... ___ .. _ ... _ ................. _ ... _ ... ___ .. 11,412 

representation of, on map ..... _ 00 • __ ••• _ ...... 00 00 .. • .. • • • • .. 11 

Tribune limestone .... _ ....... _ .................. _ ... _ ..... 411, 413,458 

Trinidad (C-20), authorities on ........ _ ... _ .. 00 ......... 00 344,584,714 

geology of. .......... _ .. _ ... _ . __ . .. . 342, 344-345, 579, 584, 706, 714-716 

Trinidad sandstone ............ _. :. _ ........ _ .......... _ ... 00 •• _ 663 

Trinity group.................. __ . 11,579,594-598,601-602,604-605 

Trout Creek sandstone ............. _ ................ 00 .... _. _ ... _ 679 

Trujillo formation ............ _ ........... 00 ...... _ 00 •• _ •• __ •• : _ • 478 

Tuckahoe group 00 .............. _ ....... _ ....... __ ••• _ ..... _. __ •• 519 

Tulare formation ....................... 00 _ ..... _. _ .. _ ..... _ ••• 817,818 

Tule Spring limestone ...... _ .......................... ___ .. _. . 357-358 

Tullahoma formation ....................... _ ......... _ .... 401,403,413 

Tully limestone .......................... _ . _ .......... _ 293, 297, 304-306 

Tulsa group ................................. _ .... ___ .. _. _. 461,463-464 

Tuomey, Michael, publications by, list of. ........ _ 00 .. _. _. _. _... 861 

Turner, H. W., acknowledgments to ........... _ _ ... 53,57,58 

cited ................. _ . _ .................. 00 ... _ • __ ... _ 363-364, 522 

publications by, list of.. .............. 00 ..... _ ........ _ .... 00 861 

Turner, H. W., and Hansome, F. L., cited.................... 555 

publication by ... _ ........................... _ .... _ ... _ ... _.. 861 

Tuscahoma formation ............... __ .. 00 _. _. _ ........... _...... 733 

Tuscaloosa formation ..... _.__ . ___ .. 11,606,612,614,637,654-655,657 

Tuscarora quartzite ...................... _ ............. _ .. 231,237,239 

Tuscumbia limestone .......................... _ .... _ .. 403,406,407,418 

Tusquitee quartzite ......... __ ... _ .... _ ...... _._ 98 

Tutshi series ................ _ ................... _ ... _ .. _ _ 635-636 

Tuxedni sandstone ......... 00 _ ••• ___ .. _ ... 00 •• _ •• _ ••• ___ • __ 11,.549,574 

Tweh·emile formation ............................. __ .. _ ... _ . _ . 702, 836 

Twentymile sandstone ................................. _ . _ ... _ .. 679 

Twin Creek formation .................... _ ........... _ 530, 56.5-566, 676 

Tymochtee member ................................ _ .. 00 .. 233,247,248 

Tyonek, geology near ................. _ ........ _ .. _ ... _._._ 708,787-788 

See also Cook Inlet. 

Tyrrell, J. B., acknowledgments to ....... _ .. _ ................ 53, 60,61 

cited .......... _ ... _ ................... 262,263,335,696-698,781-782 

publications by ... _ ... _ .................................... 220, 861 

u. 

Udden, J. A., acknowledgments to ........................... 53,59,158 

cited._ .. _ ... _ _ _. _ ... _ .. 00 ......... _ ••••• _ .... 227,595-596 

publication by .... _ .............. _ .. 00 .. 000 .. _ ....... __ •• _. _ 862 

Uffington shale ........ _ ... _ ......... 00 ..... __ .. _. _ ••• _ ... _ ••• _ 437 

Uinta formation ..... _. __ .. _ ..... _ .. _ ... _ ... _ .. _. _ ... _. 10,706,759-760 

Uinta Range, geology of. .... _. 13, 14, 64, 156, 175-176,284,377-378,515-516 

Uinta Valley, geology of. ..... _._ ... _ ... _ ..... __ ... _ ....... 706,759-760 

Ulrich, E. 0., acknowledgments to ................. 20, 53,56, 58, 59, 1CJO 

cited ........ _ ... _ ............. _ ... _ ........ _ .. __ . 77,83-84,104-105, 

ll1, 112, 120, 128, 158, 159, 162, 168,169, 171, 176,195, 20.5, 208, 

209-210,212,213,217,219,236,262---263,278,315,413, 421, 459 

publications by ......... _ .......... _ .......... _ ........ 124, 183,852 

Ulrich, E. 0., and Adams, G. I., cited ..... _._ .. __ .... _ ... _._ ... _ 458 

publication by . _ ................. _ ........... _ ... _ ..... _. , . _ 840 

Ulrich, E. 0., and Bain, H. F., publication by .......... _........ 841 

Ulrich, E. 0., and Bassler, R. S., cited .......... _ ... _. __ .. __ .. 00 164 

Ulrich, E. 0., and Cushing, II. P., cited ......... 00 .... ___ .... _ 18&-187 

publications by ...... _ ........... 00 .. 00 ••• _ •••• _ .... ___ .... 124,862 

Ulrich, E. O.,andiiaycs,C. W.,cited ............. 168,277-278,401-402 

publication by ............................. _ ............. _ 851 

Ulrich, E. 0., and Schuchert, C., cited. .. _ .... 00 .. _ _ 187 

publication by ............................... _ ...... _ .... _ 862 

Ulrich, E. 0., and Smith, W. S. T., publication by.............. 862 

Ulrich, E. 0., and Tafi, J. A., cited ............ 159-lf>O, 22S-23fi, 273-274 

Ulrich, E. 0., and Winchell, N. H., cited ...... _ ...... _ ... _ .. _. 165-166 

publication by ............................. _ .... _ .... _....... 865 

Ulsterian group ................................... _ ........... 297,300 

Umpleby, J. B., acknowledgments to ................... _........ 54 

cited ...................................................... _ 352---353 

publication by............................................... 862 

Umpqua formation . . .. . . .... .. .. .. .. .... ... .. .. .. .. ............ 771 
892 INDEX. 

Page. 

Undifferentiated pre-Cambrian, content of....................... 15 

distribution of. ................ _ .........................•..• 15,64 

representation of, on map ..... _ ..... _ .... _ ......... __ ..... 15, 16,64 

subdivision of. .. ___ .... _ .... _ ... __ ........ _ ...... _........... 67 

Ungava Bay, geology of.._ .......... _ ........ _._._ 221-222,225,264,265 

Unicoiformation ................................. __ ... _ 97 

Union formation ...... _ ....... _ ..... _ ................. _ ... 330-331.386 

Uniontown formation ................•••...•........... _ ....... 438. 442 

United States Geological Survey, bibliographies issued by........ 5 

color schemes of. ..... _ ................. _ . _ ... _ ............ _ . . 24, 26 

Unkpapa sandstone ...................................... ____ .. 569,570 

Upper Cretaceous system, content of. ... __ .. __ ... _ ...... _ _ _. 10,637 

distribution of. ........ , .... _._ .. _ .... _ ... _ 10, 637-fl39 

dlltails of.. ............. _ ........... _ .. _ _. _. _ 639-705 

map showing .............. _ ..... _ ... _ 638 

representation of, on map .......... _ ...... _ _ _. _. _ ... _. 10, 20,6-37 

See also Late Upper Cretaceous; Montana group (coal-bearing 

portion). 

Upper Huronian series ....................... _ _ ................ 14,64 

Upper Laramie formation ....................... _ .. 10,706,765, 767-7fi8 

See also Laramie. 

Upper Mottled limestone .................................. _..... 219 

Upper Ordovician. See Middle and Upper Ordovician. 

Upshurformation................................................ 444 

Upson clay...................................................... 649 

Utah (J-K 12), authorities on ....... 59, 9&--102,16&--169, 175,176.236-237, 

284, 36(\, 494,495,510-512,530,556-557,670-671,756-757,768,820 

geology of. ................................................. 13, ll4, 

72, 9&--102, 156, 16&--169, 176-176,225,236-237, 2ll9, 282-289,320, 

322-323,355,366,371,376-380,474,479-480,494--495, 500,5!0-513, 

517,530,ll37,670-671, 673--674,706,756-757,766-766,794,820-821 

publications on .................................. 34, 3&--44, 49,52-55 

See also Rocky Mountains. 

Ute formation ............................................. 106,189-191 

Utica group ......... _. 166-168, 172, 184, 187, 194-195, 196, 197-203,217,223 

Uvalde formation .............................................. 648,806 

v. 

Valdez group ............................... _.................... 2ll3 

Valley limestone...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174 

Valleytown formation .. .. .. .. .. .. .. .. .. . .. .. .. .. .. .. .. .. .. .. .. .. 98 

Vancouver Island, authorities 011. •• _ ••• _ •••.•••.••••••• 350,351,536,692 

geology of ...... _ ............... 342,350-351,500,536-538, 539,692-693 

Vancouver series ....•.......•...............•.. 351-352,537-538,539,542 

Van Rise, C. R., acknowledgments to ............................ 54,58 

on pre-Cambrian classification ............................... 66-69 

publications by ............................................. 62,862 

VanHise, C. R., and TJeith, C. K., puhJication by __ ....... _. ___ . 8fi2 

Van Rise, C. R., and others, publication by .. .. .. .. .. .. .. .. .. .. . 840 

Van Horn quadrangle, geology of. ........... _ .. _ .. _ .. _ ...... 76-77, 158 

Van Horn sandstone ........................................ _ .... 75-76 

Van Ingen, Gilbert, cited ........... _ ... _ ........ _ ... _ ... _ .... _ 121-122 

Van port limestone ...................................... _ .. _.. . 435, 444 

Vanuxem, Lardner, publications by ............ _ ............... 304,862 

Vaqueros formation ......... -.................. 753-754,814-815,817,818 

Vaughan, T. W., acknowledgments to ..... _ ... 20, 21, 54,56,57,58,59, 348 

cited •.... _ ..... 34&--349, 552,640,643,649,722-745,798,803-804,806-813 

publications by, list of........................................ 862 

Vaughan, T. W., and Hill, R. T., publication by................. 852 

Vaughan, T. W., and Stanton, T. W., cited...................... 596 

Veatch, A. C., acknowledgments to ......................... 54,56,57,60 

cited ...................... 565--566,604-605,652-653,675-677,681-682, 

684,725, 727, 729, 730, 732, 734, 73&--739, 744,765,767-768,823 

publications by......... .. .. .. . .. .. .. .. .. .. . .. .. . .. . . .. . .. . . 764, 862 

Veatch, A. C., and Han-is, G. D., publication by................. 851 

Veatch, Otto, acknowledgments to .. .. ...... .. .. .. .. .. .. .... .. .. 54 

cited ....................................... 494-495,530,057,807-808 

publication by ....................................... _ .. .. . .. 862 

Veatch, 0., and Stephenson, L. W., publication by.............. 862 

Venezuela (B-C 1&--19), authorities on ........... 342,344,583,584, 70&--709 

geology of. .......... _ .. 13, 16, 17, 64,342,344,579,583-584,706,708-709 

See also South America. 

Vennor, H. G., acknowledgments to .......................... _ 54, 60,61 

Vera Cruz (E-F 14), authorities on ...................... 551,587,588,797 

geology of ........................ _. 549,551,579,587-588,590, 794,797 

See also Mexico. 

Vermilion Cliff sandstone .............................. 514,518,556-558 

Page. 

Vermont (K-L 1&--19), authorities on ................... _ .. _ ... _ 59,192 

geology of._. __ .. _ ......... _ ....... _ ............ 15,114, 192,209 

publications on ....... _ ........ _ ............ _._ ... _ 32, 36, 42, 43,52 

See also New England. 

Vermont formation ........ _ ...................... _._ ...... _ 193 

Verne coal ............................ _._ .. _ .. __ 4C8-469 

Vicksburg group ............. _ ....... _ ....... _. 724,728,730,731,739-741 

Vilas shale ............. _ ......................... _ ... __ .. _ ...... _ 458 

Villetas formation ................................ _______ .. __ .. _. 582 

Vincentown saud ........................... _ ... _._._ .. _ 609 

Vineyard series ........................... _ .. .. .. _ ... _ (i82-683 

Vinita beds...................................................... 519 

Viola limestone ............................ _ ......... _. 159-160, 22&--229 

Virginia (J 17-18). authorities on. 59, 173, 174,230,231, 28G, 287,417-419, 51g 

geology of ............................................ _ .... _ .... 13, 

64, 65, 70, 156, 173--175,225, 2:30-232,238,239,269, 274, 285-

288,401.417-420,442-452,500, 51&--519. 611, 612-613,745,749 

publications on ......................... 33-36,40,43,47,50,51,54,56 

See also Atlantic coast; Appalachian Mountains. 

w. 

Wabash formation ...... _ ...................................... 467-468 

Wabaunsee stage ................................... _ ... _ ....... _ 458 

Waccamaw formation .......... _ ........................... __ .. 748,749 

Wadsworth coal................................................. 455 

Wailes, B. C. L., cited ................... __ ....................... 729 

Walcott, C. D., acknowledgments to ....... _ ............ 20,54,56,58,114 

cited ..... ___ ..................................... _ ... _ 75,8&--89,9&--

102, 103, 106-107, 118, 120,122-125, 127, 129, 132-134, 139-145, 

154, 169,175, 179, 192, 197,242,283,484-485,514-515,518,521--522 

publications by ....... _ ... _ ........ _ ...... _ .... _ 114, 187,236, 862-8()3 

Walden sandstone ............................... _. . .. . 44&--449, 452, 453 

Waldron clay ................................. _ ................ 232-235 

Wales series • .. . .. .. .. .. .. .. .. • . . .. • .. .. . .. .. .. .. . .. .. .. .. .. .. .. . 221 

Walker, J. B., and others, publication by ............. _.......... 848 

Walker, T. L., acknowledgments to ..................... _ 54,60 

Wall, G. P., acknowledgments to ........... _ ........ _ ... _ ... _ .. _. 54,56 

cited •........................•...•.............. _ ... _.__ 584 

Wall, G. P., and Sawkins, J. G., cited ........... _ ... _ .. 344-345,554,714 

publication by ................................. _ ... _ ........ _ 862 

Wallala group .................................... _ ........ _ .. _.. 647 

Walnut clay ............................ _ ... _ ...... _ ... 458,463,598,603 

Wamsutta group ............. _ ...... _ ............ _ .. __ .... _..... 469 

Wapanucka limestone .............................. _ ...... __ ... _ 458 

Wapiti River sandstone ................................. _ 699 

Wappinger limestone ................................... _ .. __ ... _ 184 

Wapsipinicon formation ............................... _ .. _ .... _. 290 

Ward, L. F., cited ................................. 484,513-514,518,672 

publications by, list of....................................... 8ll3 

Ward limestone ........................................ _. _ ... _.. 168 

Warley Hill marl ........................................... __ ... 737 

Warren formation ..................................... _ .. _. _ .. _ 172 

Warsaw limestone ................................. 408,409,411,413,458 

Wartburg sandstone ................................... _ .... _.... 451 

Wasatch formation .................................... _ .. __ ... _ 10,376-

379,661,670,676,677,684,706,757,758,759-760,765,767,774-775 

Wasatch Range, geology of.. ......................... _........... 13, 

14, 64, 156, 176-176,237,284,322-323,376-377 

Washburne, C. W., acknowledgments to ................... 54,57,58,60 

cited ....................................................... 690,775 

publication by .......................... _ .... _.... .. .. .. .. .. .. 863 

Washburn sandstone............................................ 458 

Washington (L-M 10-11), authorities on .... _ .. _.................. 59, 

352,572--573,623-624,685, 774, 77&--780, 826,832 

geology of.._ ..... _ ............................. 64,342, 352-353, 549, 

572-573, 579, 623--624, ()39, 685, 706, 774, 77&--780, 794, 820, 832 

publications on .......................... _. 31, 33, 35, 47, 49, 50, 52,55 

See also Pacific coast. 

Washington formation ........................................ 458, 493 

Washita group ......................... 11,579,58S,594-595,601-604,650 

Watauga shale ............................ _ ..................... 96,97 

Water lime .................................. _ ........ _.......... 245 

Watson, T. L.,acknowledgmentsto ............................. 59,70 

Waubakee formation ............................... _ ... _ .. .. . . .. 291 

Waverly group ............................................ 410,414--417 

Waynesville formation .. _ .............. _ ... __ ...... 109-110, 172,437-438 

Weaver, C. E., acknowledgments to ......................... _ 54,57 
• 

INDEX. 89\3 

Page. 

Weber formation .............................. 365-36ii. 368-369,377-380 

Webster, Arthur, acknowledgments to ..... . 

cited ................................ . 

publication by .......................... . 

Wedington sandstone ..................... . 

Weed, W. II., acknowledgments to ... .. 

cited ............................ . 

publication by ................. .. 

Weed, W. H., and Iddings, J. P., cited ....... . 

Weeks, F. B., acknowledgments to ........... . 

Weeks, F. B., cited ........................... . 

publications by, list of. ................... . 

54,60 

351 

863 

...... - 411,458 

. ..... 54,58,60 

128,381,515-516 

........... 863 

534 

.... 54, 57, 58,59 

175, 2:Jn. 322,366,377-378 

863 

Weeks, F. B., and Nickles, J. M., publication by . . . 863 

Weeks formation........................... 107 

>Vegemann, C. H., acknowledgments to............ 55,60 

Wegemann, C. H., and Gale, H. S., publications by.. . ...... 777,850 

Weisner quartzite ............. .,................................ 84 

Welch formation . . . .. ... .... ............ ... .. . . . . . 449-450 

Weller, Stuart, acknowledgments to...... .. 55,57,58 

cited ....................... 113, 176,238-239,278,290, 381i, 407,409, 410 

publications by.................................... . .... 179,863 

Wellesley formation.............................. 338 

Wellington shale .. .. .. .. .. . .. . .. . . . . . . . . 465, 487 

Wellsburg sandstone............................. 304 

Weno formation .. .. .. .. . .. .. .. .. .. .. .. . .. .. .. .. 604 

Wenonah sand .. . .. .. .. .. .. .. .. .. .. .. . .. .. .. .. .. fl09 

Western Interior coal region, geology of. . . . . . . . . . . . 455-466 

West Indies (E-G 17-19),gcologyof ................... 10.11,17, 637,706 

See also Jamaica; Curac;ao; Aruba; Bonaire; Cuba; Porto Rico; 

Santo Domingo; Windward Islands; etc. 

Weston, T. C.,cited................... 20G 

publication by................. 863 

West Union limestone .. .. .. .. .. .. .. .. .. . .. 234 

Westville formation ........................................... 386,469 

West Virginia (J-17), authorities on ..... 59,230,231,275,417-419,492,493 

geology of. ................................................. 12,225, 

239-232, 2G9, 274-275,401,417-420,442-452,474,492-494 

publications on ...................... 31, 34, 36, 43, 47, 49, 50, 52, 53,55 

See also Appalachian Mountains. 

'Vetumka shale ............................. . 

Weverton sandstone ................. _ ... _ ... . 

458,463 

108 

Wewoka formation .. .. . .. .. .. . .. .. .. .. .. .. .. . .. . .. .. 458, 463 

Weyquosque series.............................................. 683 

Wheeler, G. M., acknowledgments to.......... .. . 55,56, 57,58, 59 

Wheeler formation...................................... 107 

Whirlpool sandstone............................................ 237 

White, C. A., cited ......................... 477,479,528,752,759,779-780 

publications by, list of................................. 863 

White, David, acknowledgments to............. 20, 55,57 

cited ........ 88,329,370,398,400,439-455,468,4139,478,479, 4H7, 493,683 

publications by.................... . .. 395,864 

\Vhite, D., and Schuchert, C., cited.... .. ... 704-705,838-839 

publication by . . . ... .. . . . .. . . . . . . . .. . . .. . . 864 

White, D., and Smith, G. 0., cited............. 327 

publication by .. .. .. . .. .. . .. . .. .. 860 

White, D., and others, publications by ......................... 840,850 

White, I. C., acknowledgments to............. . ........ 55,59 

cited.................................. 418,419,433-438,440,445, 44', 

publications by.............. . . . . . . . . . . . 443,477, 8G4 

White, I. C., and Fontaine, W. M., cited.......... 493 

White, James, acknowledgments to ........ _ ...... _. 55 

White,T. G., publications by....................... . ....... 87,864 

Whiteavcs, J. F., cited ......... 333-335,337,338,H27,628,630,636,667-668 

publications by ..................... _ .......... 219,220,293,334,538 

'Vhite Cliff sandstone . . . . . . . ........................... 514-518, 

557-558,560,566--567 

White Cliffs chalk .......... _ ..................... _._............ 652 

Whitehorse sandstone .................... .. 

White limestone ............................... . 

White Pine shale ............................... . 

.. . .. .. .. 487' 488, 490 

. . - 718-719 

. .. -.-. 282-283 

'Vhite River basin, authorities on............... 394 

geology of.. .. .. . . .. . . . .. . . . . .. . . . . . . 355, 394-395 

See also Tanana basin (upper). 

White River group................... . ..... 10,706,769-770,775,833-834 

Whitewater formation ............................... _........... 172 

Whitewood limestone .... _ ......... _........... 176 

Whitfield, R. P., cited........................ . ... 126-127,407 

publications by, list of............................... 864 

Page. 

Whitfield, R. P., and Hovey, E. 0., publications by ........... 570,865 

Whitney, J.D., cited........ .. .. .. .. .. .. .. .. .... 754 

Wichita formation ..................................... 476-477,479-480 

Wilberns formation . . . . .. .. . . . . . .. .. . . . . . . ..................... 77-79 

Wilcox formation ................. . 72:1-726,731,733-735,748,749 

Wilder, F. A., acknowledgments to ..... . . ... -......... 55,57 

publications by ....................... . .. ....... 497,865 

Wilhite slate ................... ., ............ . .. ........... 94-95 

Willard, D. E., acknowledgments to......... .. ......... 55,58 

Willard shale.............................. . . _ ...... 458,465 

Williams, G. S., cited........................ ............... 305 

Williams, H. S., acknowledgments to .............. _ .... _ ........ 5.5,58 

cited ....................... 271-272,293,304,305,309-311,334-335,408 

publications by ... .. ... ... . ... . . . .. . .. . . . ....... 312,865 

Williams, H. S., and Gregory, H. E., cited.. .. .......... 328-329 

publications by............................... .. 254,865 

Williams, H. S., and Kindle, E. M., cited... 293 

publicationby....................... 865 

Willis, Bailey, acknowledgments to... 55, 56, 57, 58, 59,60 

cited ........... _ ............. _ .... _. 694 

on classification of pre-Cambrian............... . .... 65-6Q 

pulilications by........ .. _......... .. 539,865 

Williston, S. W., cited.... 477,489,490,516,530,531 

publications by, list of.......... 865 

Willow Creek formation .................................... 693,695,782 

Wilson, A. W. G., acknowledgments to.... 55,60,61 

Wilson, M. E., acknowledgments to .. _._.. . .. _ ........ _ 55 

Wilson, W. J., acknowledgments to .. _ .. _. . .... _. _ ........ 55,60,61 

Wilson formation............................... .. ..... _........ 458 

Winchell, Alexander, publication by............................. 865 

Winchell, N.H., cited.................. .. ............ 122,656 

Winchell, N.H., and Ulrich, E. 0., cited ...................... 165-166 

publication by............................................... 865 

Winchester, D. E., acknowledgments to ....................... 55,57,60 

Wind River Basin, geology of...... . .......... _ ......... 706,766 

Wind River formation ......................................... 678,766 

Wingate sandstone.............................................. 513 

Windsor formation.............................................. 386 

Windward Islands, geology of.._ ...... _ ... _.......... 16 

Windy Arm series............................................. 635 

Winfield limestone.............................................. 465 

Wing, Augustus, acknowledgments to..... . ...... 189, 192 

Winnepeg, Lake, geology of... .. . 225,261-262 

Winslow, A., cited.. .. . .. .. .. .. .. . 456,457,458 

Winslow formation............................. .. ..... 4.58, 462 

Winterset limestone.............................. 457 

Wisconsin (K-L 15-16), authorities on ... 59, 118-120,176, 180, 183,243, 290 

geology of... .. .. .. . .. .. . .. 14, 

15, 62, 64, 72,118-120, 156,176, 189-183,225,242-244,269, 29()-291 

publications on.............. 31. 34. 36, 38,40-44,46,48-56 

Wiscoy shale............................... 308 

Wise formation ........................................... _ .... _. 450 

Wissahickon mica gneiss ......................................... _ 111 

Wolff, J. E., acknowledgments to.. .. .................... 55,58,189 

publication by............................................. 865 

Woodbine formation ........................................ 11,637,650 

Woodbury clay................................. ............ 609 

Woodford chert..................................... .. ... 273-274,458 

Woodruff, E. G., acknowledgments to .... .. 

cited.. .. ........................ .. 

publications by, list of.. ........ .. 

.. .. 55,57,58,60 

678,684-685,.766,774,776-777 

.. .................... 865 

Woodside shale ................................................ 380,494 

Woodstock greensand .......................................... 746-747 

Woodville formation............................................. 420 

Woodward formation ...................................... 478,487,488 

Woodward, H. S.,cited... ............. 341 

Woodworth, J. B., acknowledgments to ........ _ ................. 56,59 

cited ............................................... 469-470,509-510 

publication by ................................................. 865 

Woodworth, J. B., and Shaler, N. S.,cited. .... .. .. .. ........ 518-519 

publication by................................................ 859 

Woodworth, J. B., and others, cited.............................. 116 

publication by .................. _............................ 859 

Woolsey, L. H., acknowledgments to .......................... 56,58,59 

publication by ................................................. 865 

Woolsey, L. H., and Emmons, W. H., cited...................... 512 

Woolsey shale................................. .. .. 127,128 
894 INDEX. 

Page. 

Worcester phyllite ............................................. 470-471 

·warthen, A. H., cited............................................ 170 

Wortman, J. L., cited .......................................... 756,758 

Wortman, J. L., and Mathews, W. D., cited..................... 759 

Wrangell Mountains, geology of............ . .... 500,543-544,708,790 

See also Alaska, southern; Copper River basin; NabesnaWhite River region. 

Wreford limestone............................... 461,464,465,487 

Wright, C. W., acknowledgments to ... ,... . ...... 56,61 

Wright, F. E.,acknowledgments to... . .. 50,60,61 

Wright, F. E. and C. W., cited... 633 

publication by....................... 8G5 

Wyman sandstone.............................................. 458 

Wyoming (K-L 12-13), authorities on .................. 21,116,117,179, 

244, 284, 386, 387, 490, 494, 495, 530-532, 565,566, 5(i7, 569,(i06, 

607, 675-G81, 684, 685, 690-691, 761-770, 774, 775, 777, 821-823 

geology of ........................ 10, 64, 71, 72, 11G-117, 179-180, 225, 

244,209,284,320,322,355,386-387,474,490-492,494-495,500, 

5IG, 530-532,534-535, 549, 557,565-571,579,606-608, 639,675-

681, 684-086, 690-691, 706, 761-770, 774-775, 777, 794, 821-823 

See also Yellowstone National Park; Rocky Mountains; Great 

Plains. 

Wyoming group ........................................... 368,492,759 

Y. 

Yakataga, Cape, geology near ....... . 

Yakima basalt .................................. . 

Yakima Valley, geology of. ........... . 

Yakutat Bay-Alsek River region, authorities on ..... . 

geology of .................................... . 

publications on ....................... . 

Yampa sandstone ............................... . 

Yeates, W. S., acknowledgments to .... . 

Yegua formation ................................... . 

Yellowstone National Park, authorities on .... . 

geology of. ....................... . 

Yellville group ............................... . 

Yeso formation .............................. . 

... 708, 788-789 

826 

774 

G1 

225,263 

34. 50,53 

378 

56,57 

. .. 724. 727,728 

534 

.. 534-535.571 

104 

3()3 

Page. 

Yoga limestone.................................. .. .. ........... 128 

York River beds................................. 334-335 

Yorktown fonnation....... ............... .... .. . . . . . . 747,748,749 

Young, G. A., acknowledgments to... . .......... 50,60-61 

Yucatan (F 16), authorities on.... . . .. 721, 79~ 

geology of................. 9. 721-722,794,797-798 

See also Mexico. 

Yukon-Porcupine region, authorities on. :395,836 

geology of .......... 355,395-396,579,63.5-636, li39, io:l, 708, 792,836-837 

See also Yukon-Tanana region; Mackenzie \"alley; Yukon 

Valley (upper). 

Yukon silt...................................... 702 

Y nkon-Tanana region, authorities on ••... til. 2fiG. 338, 339 

225. 2li6. 269, 3:38-340 

:H,49,52 

geology of. .............................. . 

publications on ......................... . 

See also Yukon-Porcupine region. 

Yukon Territory (Canada) (P-Q 7-9), authorities on...... . .. C9, 336 

geology of ...................................... G4, 2ti9, 338,342,353, 

355,394-395,500,544-545,549,576, 579, 635-636, ()39, 700-7o:J 

publications on ..................................... 35,37,4:3,46,53 

Yukon Valley, authorities on............................... til, 792 

See also Yukon Valley, middle, upper, and lower. 

Yukon Valley (lower), geology of ...... 579,633-634,639,701-702,708,787 

publications on .......................................... 38,52, 787 

See also Kuskokwim Valley. 

Yukon Valley (middle), geology of. ................ 701-703,792, 79ti, 836 

See also Koyukuk RiYer. 

Yukon Valley (upper), geology of.............. . . . . . . . . .. . . . .. 579, 

635-036, li39, 703,708,792, 798,836-837 

See also Yukon-Porcupine; Yukon-Tanana. 

z. 

Zacatecas (F-G 13-14), authorities on .................. 552.590,592,648 

geology of... . .. . . .. .. . . . . . .. .. . .. .. . 12,549, 552-554, 579, 590-592, 648 

See also Mexico. 

Zapotitlan slate............................................ 588 

Zuni sandstone.................................................. 513 

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