DEPARTMENT OF THE INTERIO 

FRANKLIN K. LANE, Secret ary 

UNITED STATES GEOLOGICAL SUR 

GEORGE OTIS SMITH, Director 

Professional Paper 108 

SHORTER CONTRIBUTIPNS TO 

GENER.AL GEOLO· Y 

1917 

DAVID WHITE, CHIEF GEOLOGIST 

WASHINGTON 

GOYERNMENT PRINTING OFFICE 

1918 
. 

NOTE.-The papers inch.ided in the ·annual volume "Shorter contributions to g~neral geology" are issued 

separately, with the final pagination, as soon as they are ready. The last paper will include a volume title-page, 

tabl.e of contents, and index for the use of those who may wish to bind the separate .parts. A small edition of 

the bound volume will also be issued, but copies can not be supplied to those who have 'received all the parts., 

II 
CONTENTS. 

·. [The let""' in pa,nth""' p.-ecedingthe titl" ..-e thooe medto d"ijomto the pape" lr advance publication.] 

_ ·Page • . 

(A) Baked shale and slag formed by the burning of coal beds, by G. S. Rogers (pu ' lished Mar. 3, 1917)...... . 1 

(B) The N e~ngton moraine, Maine, ' New Hampshire, and Massachusetts, by F ·l Katz and Arthur Keith 

(C) A <:a~:=~~ ~~~~l~o!:~2s~~~i~~~ ·i~- ~~~~h~~~. N~~ -M~~i~~: by -N ~ "H~ :D~~t~~-(~~bii-si;e~ M~~- 2?: i9i 7) ~ ~ ~ {D) Wasatch fossils m so-called Fort Umon beds of the Powder River basm, Wyo., , and therr bearmg on the 

stratigraphy of the region, by C. H. Wegemann (published May 29, 1917) ............................ . 

(E) Geologic history indicated ·by the fossiliferous deposits of the Wilcox group (Eocene) at Meridian, Miss., 

by E. W. Berry (published June 22, 1917) ........................•......... 1 ........................ -

(F) A~~~~)~. fro~_~~· -F~ontier_ ~~~~~i~n _ ~~ ~~u~h~es~- ~:~~: ~~ _ F: _n: .ro~~~~~ _ ~pu~~~~~ -~~g: (G) The stratigraphic position and faunal associates of the orbitoid Foraminifera ~ the genus Orthophragmina 

from Georgia and Florida, by C. W. Cooke (published Dec. 12, 1917) . .... •........................... 

(G) Orbitoid Foraminifera of the genus Orthophragmina from Georgia and Florida by J. A. Cushman (published Dec. 12, 1917) ............... -... -... -.. --.--.- ·--- ·- ·- ·-- ·--··-·-~ ···-··---·-·············· {H) The Pliocene history of norther~ and central Mississippi, by E. W. Shaw (publis~ed Feb. 15, 19'18) .... ~ .. . . 

{I) St~~~ii~~~~~- ~~. ~~~~~-e-s~~~~ _ ~~i~~ -~~~. ~~~~~~~~~~~~ _ ~ ~~" ~~~~~~r_e:. ~:. -~ ~ -~·- ~~~~ _ ~~~~~~s~~~ _ ~-e·c~ 

{J) T~:~l;~I_l;roa;:~~r~~~~~s~~:!i~:nt.o ~~h ~~~~~~~- ~~~~~~~ ~~ -t~~ ~~~~~~~-~~f.~~ ~1~~~~: -~~ .~: _J_. _ ~~~~i~~ {K) The Helderberg limeston~ of central Pennsylvania, by J. B. Reeside, jr. (publ~shed Dec. 13, 1917). -- .. . 

(L) Stratigraphy of the Hanna Basin, Wyo., by C. F. Bowen (puplished May 7, 191 ) ... ·.· ................... . 

Index .......... ." .. ' ....................................... -........ ···············-···-···---··-·· 

III 

. n 

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57 

61 

73 

109 

115 

125 

165 

179 

185, 

227 

237 
·' 

ILLUSTRATIONS. 

PLATE I. Effects of the burning of coal beds in eastern Montana: A, A chimney or core of hard fused 

roc'k projecting through partly baked strata near Miles City; B, Coal bed 11 feet thick on 

. Custer Creek near Yellowstone River, between Miles City and Terry ............... . . . 

II. Photomicrographs of vesicular slag formed by the burning of coal beds: A, Glassy slag 

with spherulitic structure; B, Holocrystalline slag composed chiefly of diopside and 

plagioclase ...................................................... · ................ . .. . 

III. .Photomicrograph of holocrystalline slag ................................................ . 

IV. MapofNewEnglandcoastalregio~fromPlum Island, Mass., to Casco Bay, Maine, showing 

v. 

distribution of moraine and outwash deposits ................. , .................. · .... . 

A, B, Gravel pit in Biddeford, Maine~ ..... ~ ............................................ . 

VI. A, B, Moraine front and outwash, Merriland Ridge,. Wells, Maine .......... ~ ·.; .......... . 

VII. South side of railroad cut across Merriland Ridge, Wells, Maine ........................... . 

VIII. A, West side of inner slope of Newington moraine on Bay Side road in Newington, N. H.; 

B, Sand pit in Pine Hill Cemetery, Dover, N.H ................................... ; .. 

IX. Map of parts of Newington, Greenland, and Portsmouth, N. II., and diagrammatic sections 

showing relation of the Newington moraine to rock and till and Pleistocene marine sediments.: ......................................................... •............. •...... 

X. A, B, Moraine gravel on New Road, Portsmouth, N.H .................................. . 

XI. Wiggins gravel pit, Po~tsmouth, N. H ........................ ~ .......... ~ ............... . 

:XII. A, _Gravel pit on Middle Road, Portsmouth, N.H.; B, Gravels and sand, perhaps of kame 

origin, . in Sunset Hill, Eliot, Maine ......... ~ ....................... · ................ . 

XIII. Map of part of New Mexico and adjoining regions, showing relations of lower Paleozoic rocks. 

XIV. A, Bliss sandstone in Bennett Canyon, 18.miles northeast of Las Cruces, N. Mex.;· 

B, West face of Sandia Mountains at Bernalillo, N. Mex .................. -............ . 

XV. Views on east side of San Andres Mountains, west of· Alamogordo, N.Mex.: A, View looking east out of mouth of Hembrillo Canyon; B, View looking northeast in Goodfortune 

. Canyon ...... • ............................................. .' .......... . ~ ............. . 

XVI. A, West face of Caballos Mountains near Apache Canyon, Sierra County, N. Mex.; B, 

Paleozoic rocks on granite at Capitol Dome, Florida Mountains, Luna County, N.Mex .. 

XVII. A, Sierra Cuchillo west of Palomas Springs, N.Mex.; B, Fault in limestone at Palomas 

Gap, Caballos Mountains, Sierra County, N.Mex ........................................ . 

XVIII. A, Limestones from Ordovician to Pennsylvanian on granite, Sheep Mountain, San .Andres 

Mountains, Socorro County, N. Mex.; B, East face of San Andres Mountains at Rhodes 

Canyon, Socorro County, N. Mex ...................... ~ .........................•..... 

XIX. 4, North side of entrance to Alamo Canyon, 3 miles southeast ot Alamogordo, N. Mex.; 

B, .Kelly limestone at Grappic mine, near Magdalena, N.Mex ........................ . 

XX. View looking southeast· along west front of Sacramento Mountains from Alamogordo, Otero 

County, N.Mex ................ . . · .................. ~ ................................. . 

XXI. · View along west front of Sacramento Mountains at Agua Chiquita Canyon, . Otero County, 

N.Mex ............... · ......... , .......... .......................................... . 

XXII. A, Sandstone bed in Lance formation showing large "concretions"; B, Great Pine Ridge, 

Wyo., formed .by outcrop of Fort Union formation~ ...................... .' ............. . 

XXIII. A, Badlands in Wasatch formation at fossil locality near the Davis ranch, Sussex, Wyo.; 

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B, :Kingsbury conglomerate on Kingsbury Ridge, 8 miles southwest of Buffalo, Wyo...... 59 

XXIV-XXVI. Nelumbo protolutea Berry, n. sp ........................................................ 70-72 

XXVII. A, Plant-bearing shale in Frontier formation 1 mile east of Cumberland, Wyo.; B, White 

plant-bearing shale in Frontier'formation south of Little Muddy Creek, near Cumberland, 

Wyo . . ....................................................................... ...... 74 

XXVIII-XXXIX. Fossil flora from the Frontier formation ............. · ................................... 98-107 

XL-XLIV. Species of Orthophragmina ............... · ..............•.•.•...•...................... 119-124 

XLV. Generalized eMt-west and north-south sections of Mississippi ................... ~ . . . . . . . . 126 

XLVI. Stratification and general appearance of massive, cross-bedded, and laminated material 

formerly included in the "Lafayette formation," now interpreted as belonging with 

IV 

. various formations underlying Mississippi ... , ....•.•....•• ~.......... . . . . . . . . . . . . . . 132 
ILLUSTRATIONS. 

PLATE . XLVII. Stratification and general appearance of material formerly regarded as "Lafayette formation," 

at and near type locality, now regarded as belonging to the Wilcox group . . ....... -....... . 

'XL VIII. Stratification and general appearance of Pliocene and early Pleistocene terrace deposits, most 

of which have .been classified as ' ' Lafayette formation'' .. . ................. . .......... . . . 

XLIX. Stratigraphic relations of Pliocene terrace deposits .............. . . . .................... . ... . 

L. Hollow pebbles of iron oxide "(Klappersteine), possibly produced by replacement oflimestone 

pebbles .............................. . ............. ': ....... . ....•.......... . __ ..... . _. 

LI. Uneven bedding and gravelly portions of Pliocene terrace c;leposits ................. : .. . .... . 

LIL Typical exposures of colluvium ......•..................... . ......... . ........ : ........... . 

LIIL Exposures suggestive of origin o£ colluvium ........ : .................. -................... . 

LIV. Recently formed deposits of known origin and history, somewhat resembling the older colluvium but still differing rather markedly ...... _ ....................................... ~ .. . 

LV. Remarkable pocket-like features, suggesting filled burrows or potholes, and pebbles and 

boulders of quartz and quartzite from colluvium .......................... -- . -. -. .. . : ... . 

LVI. Residuum or material in place but modified somewhat by we~thering, though little .if any 

part has been removed ............................................................. . ... . 

LVII. Views illustrating reddening and probable concentration of iron compounds near the surface .. 

LVIII. Profiles along Illinois Central Railroad from Grand Junction, Tenn., through Jackson to 

Martinsville, Miss., and from a point near Memphis, Tenn., to·Grenada, Miss ............. . 

LIX. Views illustrating occurrence and mode of develop~ent and the excellent exposures afforded 

by old field gullies .............. . · ..................................................... . 

LX. View<:> illustrating peneplains and monadnocks .................................. . ......... . 

LXI. Geologic sketch map of southwestern Maine and southeastern New Hampshire .............. . 

LXII. Map of northeastern :Montana and adjacent parts of Canada, showing the distribution of erosion 

levels and gravel horizons ........ .. ... . ............................................. . . . 

LXIII. A, Surface of the Flaxville plateau, northeastern Montana; B, Outcrop of cemented Flaxville 

gravel in escl;U'pment of plate·au northwest of Opheim, Mont.; C, Escarpment of the Flaxville 

plateau, northeastern Montana, showing outcrops of cemented sand and the thickness of the 

Flaxville gravel ............................................. . ....................... . . 

LXIV. A, Cemented gravel interstratified with cemented sand 9 mlles northeast of Scobey, Mont. ; 

B, Cross-bedding of Flaxville gravel5 miles west of West Fork post office, Mont ........... . 

LXV. A, Railway cut west of Flaxville, Mont. ; B, Vandalia dam, Milk River, Mont., showing the 

escarpment surrounding the late Pliocene or early Pleistocene bench; C, Escarpment surrounding the late Pliocene or <€arly Pleistocene bench in Milk River valley, Mont. ....... . . 

LXVI. Chart showing thickness, character, and probable correlation of formations between Medicine 

Bow, Wyo., and Coalville, Utah .... . ......... ~ ........ . ............................... . 

FIGURE l. Diagrammatic section of moraine and outwash deposits of Merriland Ridge, Wells, Maine.------ . . -

2. Columnar sections showing stratigraphic relations of Paleozoic rocks in southern New Mexico ..... . 

3. Section across the Franklin Mountains 3 miles north of El Paso, Tex ... ... . __ ....... . ............ . 

4. Sectipn across Cooks Range at Cooks, N. Mex ..... _ ........................................... . 

5. Section through the Klondike Hills, Luna County, N. Mex ... . ................................ . 

6. Section through the Snake Hills, southwest of Deming, N.Mex ................• ................ 

7. Cross section showing relations of Paleozoic rocks in the Silver City region, N.Mex ....... _·_ ..... . 

8. Section across the Caballos Mountains, southwest of Engle," N.Mex ....... . ..................... . 

9. Sections across the San Andres Mountains, Socorro and Dona Ana counties, N.Mex .... . ...... . . . 

10. Section through the Lake Valley mining district, Sierra County, N. Mex ........... _ . . ....... _ .. _ 

11. Columnar ctions showing stratigraphic variations in lower Paleozoic rocks in the San Andre::: 

Mountains, Dona Ana and Socorro counties, N. Mex . .... . . . ................. ~ ............ _ .. 

12. Section from the Mimbres Mountains eastward through Kingston and Hillsboro, N.Mex .......... . 

13. Section of the west front of the Sacramento Mountains 12 miles southeast of Alamogordo, N.Mex .. 

14. Section along western slope of the Sacramento Mountains east of Alamogordo, N .. Mex., from La Luz 

Canyon to Grapevine Canyon ........................................................ . ..... . 

15. Section across the southern part of the Florida Mountains, Luna County, N.Mex .............. . ·.. 

16. Map of northeastern Wyoming ............................ . ................. . .............. . . . 

17. Zamia mississippiensis Berry, n. sp ............. ; ........................... . ................. . 

18. Sketch map showing the existing and gBologic distribution of Nelumbo .......................... . 

19. Map showing position of stations on Chipola River, Fla., and Flint River, Ga., at which specimens 

of Orthophragmina were collected .......... .. .. _. __ ...... . .. ___ .. . ....... . ................... · 

20. Map showing position of station 7348, Troy Springs, on Suwannee River, Fla ... -................ . 

v 

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VI ILLUSTRATIONS. 

FIGURE 21. Diagram showing general nature and areal arrangement of materials underlying the surficial deposits 

Page. 

of 1-lississippi ........ ".............................. .......................... . . ............ 127 

22. Diagram showing the slope of the Cretaceous peneplain, according to l!ayes and Campbell, and 

the slope of the Paleozoic floor beneath the Cretaceous deposits of Mississippi, which has been • 

considered as being equivalent to this peneplain ............................. __ .............. 150 

23. Diagrammatic profile to _show relations of upland surface feapures_ of 'Mississippi to the peneplains 

in a portion of Tennessee to the northeast .............. _ : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151 

24. Diagr~~a~ic_ :ross section of Pliocene deposits and profil~ of Pliocene. terraces in the south end 

of MlssiSSlppl. _ . _ ......................................... _ . _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 

25. Sketch map shoWing shapes of drainage basins in Mississippi. .... ~... • . . . . . . . . . . . . . . . . . . . . . . . . . . 159 

26. Index map showing area in southwestern Maine and southeastern New Hampshire................ . 165 

27. Diagrammatic .section showing the relative altitudes ·of the four erosion levels represented in northeastern Montana and the adjacent part of Canada .. .' .................... _ . . . . . . . . . . . . . . . . . . . . . 184 · 

28. Map showing outcrops of Helderberg limestone in Pennsylvania and Maryland... . . . . . . . . . . . . . . . . 189 

29. Diagram showing relations of the zones and sub zones of the Keyser limetone member of the Helderberg limestone in Pennsylvania ........................ _ ........................ _............ 190 

· 30. Diagram showing relations of the zones and subzones of the Keyser limestone member of the Helderberg limestone in Maryland ................... _ ............. _ .......... ... _ . _ .............. · 194 

31. Key map showing location of Hanna Basin, Wyo .... __ .............. " .... _ ... ; ~.............. . . 227 

• 
DEPARTMENT OF THE INTERIOR 

FRANKLIN K. LANE, Secretary 

UNITED STATES GEOLOGICAL SURVEY 

GEORGE OTIS SMITH, Director 

PROFESSIONAL PAPER 108-A 

BAKED SHALE AND SLAG FORMED BY THE 

BURNING OF COAL BEDS 

BY 

G. SHERBURNE ROGERS 

Published March 3,1917 

Snorter contributions to general geology, 1917 

. (Pages 1-10) 

"\V ASHINGTON 

GOVERNMENT PRINTING OFFICJ<J 

. 1917 
DEPARTMENT OF THE INTERIOR 

FRANKLIN K. LANE, Secretary 

UNITED STATES GEOLOGICAL SURVEY 

GEORGE OTis SMITH, Director 

Professional Paper 108-A 

BAKED SHALE AND SLAG FORMED BY THE 

BURNING OF COAL BEDS 

BY 

G. SHERBURNE ROGERS 

Published March 3, 1917 

Shorter contributions to general geology, 1917 

(Pages 1-10) 

WASHINGTON 

GOVERNMENT PRINTING OFFICE 

1917 
CONTENTS. 

Introduction .... . ... . . . ................. . ..... . ... ... .. . . . ..... . . . . .. . . . ....... . . ...... . ... .. .. ... ..... . 

Causes of burning .... .. ........................ ...... .. .. ..... ... .. ....... . . .. .. . . ... . .. ... .. . . . ..... . . . 

General effects of burning on the overlying strata .. ... .. . . ... .. . . .. , . ... .... .. . .. ... . ... .... ... . . . ... ..... . 

Petrologic character of the rocks formed .. . ......... .. . . . . . . ..... .. .. ... ....... .. ... . ...... . ... ... .. .. . . .. . 

Character of the original sedimentary rocks ...... ... .. . ... . ...... . ... . ..... ...... .. ... . ...... . .. ...... . 

Baked rock .......... ... .......... .. .. . .. .. . . . . : . .... . ..... .. .... . ....... . ........ . ............. . . . . 

Vitrified shale . ............. .. ........ . . . .. . . . ......... . ....... . ... . . . ............. . .... ___ . _ .. ____ . 

Glassy slag ..... . ... . .. . . -. . ......... .. . . ... .. ....... .. ..... . .. . . . .. . . · .. , . . . . ...... . .. .. _ . . _ . . . _ . __ . .. . 

Recrystallized slag .......... .. .. .. ... . ... ... . . ... . ..... . ........... __ .. . _ . . _ . . ... __ _____ __ . ___ . __ . _ .. 

Chemical changes ... . .. . . . . . ........... .. . .. . . . . ... .. ....... . . .. .. . ...... . ... . ... . ... .... .. ...... ....... . 

ILLUSTRATIONS. 

PLATE I. Effects of the burning of coal beds in eastern Montana: A, A chimney or core of hard fused rock projecting through partly baked strata near Miles City; B , Coal bed 11 feet thick on Custer Creek near 

Page. 

1 

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4 

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6 , 

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I 8 

Page. 

Yellowstone River, between Miles City and Terry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 

II. Photomicrographs of vesicular slag formed by the burning of coal beds: A, Glassy slag with spherulitic structure; B, Holocrystalline slag composed chiefly of diopside and plagioclase... .. . . ... .. .... 6 

III. Pliotomicrograph of holocrystalline slag.............................................. .. . . . . ...... 8 

NOTE.-The papers included in the annual volume "Shorter contributions to general geology" are issued . 

separately, with the final pagination, as soon as they are ready. The last paper will include a volume title-page, 

table of contents, and index for the use of those who may wish to bind the separate parts. A small edition of 

the bound volume will also be issued, but copies can not be supplied to those who have received all the parts. 

II 
SHORTER CON'TRIBUTIONS TO GENERAL GEOLOGY, 1917. 

BAKED SHALE AND SLAG FORMED BY THE BURNING OF COAL BEDS. 

By G. SHERBURNE RoGERs. 

INTRODUCTION. 

The baking and reddening of large masses of 

strata caused by the burning of coal beds is a 

str~king feature of the landscape in most of the 

great western coal-bearing areas. The general 

character and br6ader effects of the burning 

have been described by many writers/ but 

the fact that in places enough heat is generated 

to fuse and thoroughly recrystallize the overlying . shale and sandstone has received less 

a,.ttention.. Some of the natural slags thus 

formed simulate somewhat abnormal igneous 

rocks, but others consist largely of rare and 

little known minerals. A wide range in the 

mineral composition of such slags is to be expected, depending on the composition of the 

original sediment and the conditions of fusion 

and cooling. These products of purely thermal 

metam0rphism offer a fertile fiel.d for petrologic investigation. 

The writer has observed the effects produced 

by the burning of coal beds in several localities 

in Montana, particularly along upper Tongue 

River in the southern part of the State, in the 

district lying southeast of the mouth of Bighorn 

River, and in the Little Sheep Mountain coal 

field north of Miles City. A number of specimens of the rock formed have been examined 

under the microscope, though time has not 

been available for a systematic examination. 

The writer is greatly indebted to Mr. E. S. 

Larsen for assistance in the study of some of 

the minerals. 

1 Allen, J. A., Metamorphism produced by the burning of lignite beds 

in D.akota and Montana territories: Boston Soc. Nat. Hist. Proc., vol. 

16, p. 246, 1874. See also Lewis, Meriwether, and Clarke, William, History of the expedition under the command of Lewis ahd Clarke, vol. 1, 

pp. ~80, 189, Philadelphia, 1814; Hayden, F . V., Geological report of the 

exploration on the Yellowstone and :Missouri rivers, pp. 56-103, 1869; 

and Dawson, G. M., Report on the geology and resources of the region 

in the vicinity of the forty-ninth paralle:, pp. 1G4--1G9, Montreal, 1875. 

70460°-17 

CAUSES OF BURNING. 

Most writers on the burning of coal beds have 

attempted to explain the mode of ·their ignition, .which they usually ·ascribe to lightning, to 

prairie or forest fires, to the agency of man, 

or to spontaneous combustion. AU these 

agencies have probably been effective in one 

place or another. 

Lightning has doubtless ignited some · beds, 

especially those exposed on th~ higher hills, 

but it is apparently inadequate to account for 

the burning of beds over great areas. There 

are also well-authenticated reports of the ignition of beds by prairie fires, 2 but it may well 

be doubted whether this agency has often 

been effective in the sparsely grassed badlands,. 

where burning is so common. Similarly, the 

writer knows of one locality in which a bed of 

coal "11 feet thick was ignited by the camp 

fires .of a round-up outfit, but much of the 

burning evidently took place many thousands 

of years ago and some of it probably dates back 

to Pleistocene time. 3 Ignition from . an ex-;-

traneous source is perfectly possible and may · 

be the most plausible explanation in any given 

instance, but the fact that burning on the outcrop is so common as to be actually characteristic of the coal beds over an area greater 

than 200,000 square miles indicates a more 

widespread mode of origin and one less depen ... 

dent on special local conditions. 

Ever since coal first became widely used as 

fuel the possibility of its spontaneous combustion has been recognized. Disastrous fires 

have started through spontaneous combustion 

in mines, many others at the surface in piles of 

2 Allen, J. A., op. cit., p. 261. 

a Idem, p. 258. Also Collier, A. J., and Smith, C. D., The Miles 

City coal field, Mont.: U.S. Geol. Survey Bull. 341, p. 45, 1909. 

1 
2 SHORTER ·coNTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

culm or slack coal, and others in stocks of coal 

held in storage or undergoing shipment, 

especially at sea. Because of its economic importance the phenomenon has been carefully 

studied by many observers, and although there is considerable disagreement as to detail the 

main determining conditions have been well 

outlined. Thus, it is . generally recognized 

that only coals that contain a moderate to high 

proportion of volatile matter are subject to 

spontaneous combustion; that the more finely 

divided the coal the more liable it is to ignite; 

and that a small increment of heat from an 

outside source is an important contributing 

cause. 

Most of the coal in the Western States that 

has burned at the outcrop is of lignitic or-subbituminous grade; this coal when exposed to 

the air loses moisture and tends to slack or 

crumble to fragments. All freshly mihed coal 

absorbs oxygen and according to Lewes 1 may, 

if in fairly small fragments, absorb two to 

three times its own volume. This absorption 

of oxygen takes place at ordinary temperatures 

but proceeds more rapidly at higher; temperatures, and as the process itself generates some 

heat it is self-accelerating. The heatfirst generated may be due merely to the compression 

of the gas, but a slow oxidation of. resins or 

unsaturated hydrocarbons in the coal, with the 

formation of humic or other acids, probably 

soon begins. The elaborate experiments of 

Parr and Kressmann 2 indicate that this reaction assumes positive · activity at about 80° C. 

With rise in temperature the occluded oxygen 

. becomes ·more active, combining with certain 

hydrocarbons and converting them to carbon 

dioxide and water. According to Parr and 

Francis 3 this reaction begins only when the 

coal becomes heated to 120° to 140° C., but it 

represents a critical stage in the process of 

oxidation, for so much heat is generated that 

the temperature thereafter rises rapidly. At a 

little over 200° C. autogenous oxidation begins 

and at 350 to 450° c~ actual ignition takes place. 

1 Lewes, V. B., The .carbonization of coal, p. 23, London, 1912. See 

also Parr, S. vV., and Barker, Perry, The occluded gases in coal: Illinois 

Univ. Eng. Exp. Sta. Bull. 32, 1909; White, David, The effect of oxygen 

in coal: U.S. Geol. Survey Bull. 382, pp. 63-71, 1909; and Chamberlin, 

R. T., Notes on explosive mine gases and dusts: U. S. Geol. Survey 

Bull. 383, pp. 15, 60, 1909. 

2 Parr, S. W., and Kressmann, ~· vV., The spontaneous combustion 

·of coal: Illinois Univ. Eng. Exp. Sta. Bull. 46, pp. 24, 52, 1911. 

a Parr, S. "\V., and Francis, C. K., The modification of Illinois coal by 

low temperature distillation: Illinois Univ. Eng. Exp. Sta. Bull. 24, 

1908. 

According to experiments by Fayol,4 however, 

coal in a state of fine dust ignites at a much 

lower temperature, gas coal igniting at 200° C. 

and lignite at 150° C. 

The oxidation of pyrite or marcasite in the 

coal was once considered the chief cause of 

spontaneous combustion, but it is now known 

that coals practically free from iron sulphides 

may spontaneously ignite. Some a:uthorities 

therefore hold that the influence of pyrite is 

negligible and that at the most it merely 

increases the general rise in temperature and by 

swelling splits up the coal, thus exposing fresh 

surfaces to the action of atmospheric oxygen.5 

Parr and Kressmanri....:find7 however, that the 

oxidation of pyrite ii+ :the presence of moisture 

results in a distinct increment of heat, and as 

this reaction takes place at ordinary temperature they believe that it is one means by which 

the mass is heat~d to the point at which active 

oxidation of the coal itself commences. · They 

state that the oxidation of one-fifth of the 

pyrite in a coal containing 6 per cent generates 

sufficient heat to raise the temperature of the 

mass 70° C., assuming no loss by radiation.~ 

As the conductivity of coal is very low compared with that .of the surrounding rocks, according to figures given by Prestwich/ it seems 

probable that loss of heat by radiation is slow 

and that small amounts of heat generated 

within the coal may well be conserved to produce far-reaching results. 

It is generally recognized that the presence 

of moisture favors spontaneous combustion. 8 

In fact, Dennstedt and Biinz,9 as a result of experiments, conclude that "self-ignition increases in a ratio corresponding to the amount 

of moisture [water of constitution] in air-dry 

coal." Opinions differ1 however, as to whether 

its action is chiefly mechanical, catalytic, or 

chemical. It is also known that inflammable 

gases are occluded in coal, and though it may 

be doubted that these gases are the direct cause 

of spontaneous combustion it is evident that if 

the coal is heated by oxidation to the temperature at which these gases can unite with atmosf Fayol, Henri, Etudes sur l'alteratio.O: et la combustion spontanee 

de la houille exposee a l'air: Soc. ind. min. Bull., ~d ser., vol. 8, pt. 3, 

1879. . 

• Lewes, V. B., op. cit., pp. 21-22. 

e Parr, S. W., and Kressmann, F. W., op. cit., p. 34. 

7 Boulton, W. S., Practical coal mining, vol. 2, p. 331, London, 1907. 

sParr, S. W., and Kressmann, F. "\V., op. cit., p. 52. 

9 Dennstedt, M., and Biinz, R., Die Gefahren der Steinkohle: Zeitschr. 

angew. Chemie, vol. 21, P:::>· 1825-1835,1908. 
BAKED _SHALE AND SLAG FORMED BY BURNING OF COAL BEDS. 3 

pheric oxygen they may become an important 

contributing cause. Penhallow 1 believes that 

the burning of ligni-te beds is caused by the spontaneous ignition of escaping gases, particularly 

sulphureted hydrogen, carbureted hydrogen 

(methane~), and phosphureted hydrogen. 

chemical character of four typical coals that 

have burned extensively on the outcrop is 

shown by the first four analyses, and the character of a coal that has nowhere burned by the 

last analysis. A considerable range ~ com:-

position is shown by these analyses, though all 

show high moisture and volatile matter but 

Analyses of lignite and coal from Montana and Wyoming. fairly low sulphur. It will be noted that the 

Made at the Pittsburgh laboratory of the Bureau of Mines; F. M. Stan- coal that has nowhere burned is . much higher ton and A. C. l!1eldner, chemists in charge.] 

in sulphur than any of the others; whether its 

10898 64G9 11111 8465 14755 lack of tendency to burn-is due to the offsetting 

--------!·---------- of this factor by the low percentage of mois- SAMPLE AS RECEIVED. 

Proximate: 

Moisture ......... . Volatile ma.tter .. _ . Fixed carbon ..... . Ash ................... . Sulphur ............... . 

Ultimate: 

Hydrogen .. ~ ..... . Carbon ............ . Nitrogen .......... _ Oxygen ....... _ . __ 

42.8 26.8 22.6 . 29.4 19.8 

25. 7 32. 8 31. 9 25. 4 30. 7 

26. 9 27. 9 39. 5 38. 8 35. 2 

4.6 12.5 6.0 6.4 14.3 . 24 . 64 . 51 . 37 1. 50 

7. 21 6. 04 . ----- -.... - ------ 36. 21 42. 72 - . - - - - -.. -- - - - - - -- . 62 . 60--.-----.--.------

51. 08 37. 53 -.. - - - - - -- -- . -. - -- 6, llO 7, 340 8, 811 7, 170 8, 579 

ture and the high ash content is a matter ?f 

conjecture. 

British thermal units .. Loss of moisture on air 

drying ... "·------ .... 

The physical factors promoting spontaneous.· 

combustion are a finely divided condition of 

the coal, a slight increment of heat from an 

outside source, and a sufficient volume of coal 

to retard ·toss of heat by radiation. A pile· of 

coal exposed to the direct rays of the sun 

would thus be liable · to become heated arid 

finally ignite. In general, the outcrop of a 

35.3 20. 5 3. -7 19.3 8· 5 coal bed, even in the arid western coal fields, 

AIR-DRIED SAMPLE . 

Proximate: 

Moisture .......... . Volatile matter .... . Fixed carbon ..... . 

Ash ................... . Sulphur ............... . 

11. 6 7. 9 19. 6 12. 5 12. 3 

39. 7 41. 3 33. 1 31. 4 33. 5 

41.5 35.1 41.1 -48.1 38.5 

7. 2 15. 7 6. 2 8. 0 15. 7 . 37 . 81 . 53 . 46 1.64 

weathers down slowly and is more or less 

covered by talus, so that the oxidation of the 

coal is too slow to generate much heat. Where 

a young, rapidly cutting gulch intersect~ ·a 

coal bed, however, a perpendicular face of coal 

may be formed, and as this is undercut by the Ultimate: , Hydrogen ........ . Carbon ........... __ 

Nitrogen .......... . 

5. 09 4. 73 . . . . . . . . . . . . . . . . . . . stream a considerable mass of finely broken but 

55· 97 53· 74 ------ ------ ------ · fairly fresh coal may accumulate at the base· . 96 . 75------------------ . Oxygen ..... ___ .. . 30. 44 24. 28 . _ .... _ ... ___ ... _. of the bed. Under such conditions oxidation 

British thermal units .. . 9, 440 9, 238 9, 153 8• 880 9• 376 would be fairly rapid, especially as the normal 

LIGNITE OR COAL KNOWN T? BURN ON O}JTCROP. 

10898. Lignite from Culbertson lignite fie'ld, Mont. Red Bank open-cut 

mine, sec.IO, T. 28 N., R. 59 E. Fort Union formation. 

6469. Subbituminouscoalfrom Buiialocoalfield, Wyo. Mitchell mine, 

sec. 26, T. 51 N ., R. 82 W. Fort Union formation. 

17711. Subbituminous coal from Tullock Creek coal field, Mont. Prospectin sec. 30, T. 1 N ., R. 38 E. · Fort Union formation. 

8465. Subbituminous coal from Bull Mountain coal field, Mont. McCleary prospect, sec. 26, T. 9 N., R. 30 E •. Fort Union formation. 

, COAL NOWHERE BURNED ON OUTCROP. 

temperature of the coal, if exposed to the direct 

heat of the sun, would reach 130° F. (55° C.), 

or more on summer afternoons. 

In the writer's opinion most of the burning 

of western coal beds has been spontaneous and 

has originated under conditions similar to those 

just described. C. H. 1Wegemarin,2 who has 

studied particularly the relation of topography 

to burning, finds that burning is most prevalent 

14755. Subbituminous coal from Tqllock Creek coal field, Mont. Pros- along rapidly cutting- streains and believes 

pect 12 miles southeast of Bighorn. Lance formation. that it is partly a function of the character of 

It is evident from the foregoing summary 

that both chemical and physical factors enter 

into spontaneous combustion. As regards 

chemical· compositi~n, coals highest in volatile 

matter, moisture, and sulphur are most liable 

thus to ignite. In the accompanying table the 

1 Penhallow, D.P., Tertiary plants of British Columbia: Canada Geol. 

Survey Pub. 1013, pp. 148-149, 1908. 

the topography. The writer has 'observed 

beds actually burning at six -localities, and in 

all of them combustion evidently started in a 

gulch on . a small, rapidly cutting stream. 

Field studies indicate that two other generalizations can be made: First, thin beds are less 

commonly burned than thick ones, probably 

2 Personal communication. 
4 ·SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

because piles of coal large enough to retain 

.self-generated· heat can not accumulate along 

their outcrop; and second, beds of impure coal 

burn less commonly than those of clean coal. 

feet back from the outcrop, and as the coal 

burns out and these beds cave they tend to 

break into irregular fragments. Incipient fusion may occur on the edges of these fragments, 

which therefore have a tendency to cohere 

GENERAL EFFECTS OF BURNING ON THE OVERLYING STRATA. and thus form a stable rock 30 or 40 per cent 

of whose volume is air space. It is chiefly 

The rocks overlying a burned-out coal bed through the crevices in this rock that oxygen 

present widely different appearances, ranging is supplied to the coal burning farther back. 

from Teddened and only slightly hardened How far the burning extends back from the 

shale or sandstone through vesicular glassy outcrop is a n1atter on which there is little 

slag to gray medium-grained rock. These positive info'rmation. Field studies indicate 

broader·differences are due chiefly to the degree ~hat a bed under 20 feet or less of cover may 

of heat to which the material has been subjected~ burn out completely under large areas, and 

and their relati.ons to the coal bed may be similarly that all the coal underlying a small 

:plore clearly understood if the process of burn- butte or a narrow neck of land may burn out 

ing is briefly considered. even though the overburden is 100 feet or more 

Whatever the cause of ignition, the · com- thick. Bowie 1 cites an instance -in which 

hustion apparently always starts at the surface the coal burned out to a point almost 500 feet 

and spreads first along the outcrop. The from the outcrop, as ascertained in the course 

presence of the burning bed is disclosed by the of mining the unburned portion of the , bed_. 

(3moke and fumes which rise from it, and by According to F. R. Clark/ development at 

the heat at the surface of the earth near the Sunnyside, Utah, has shown that burning may 

outcrop or. above the bed; which becomes so extend even farther back under high spurs 

intense that all vegetation is killed. As the jutting out from the main ridge. In general, 

coal burns out the overburden generally caves, however, where there is a cover .of more than 

and large fissures may be opened in the surface 50 or 100 feet, and where the outcrop of the 

of the ground above the bed. During this bed is fairly straight, it seems probable that 

stage of the burning the heat is for the most burning does not extend more than 200 or 300 

part dissipated and the overlying strata are feet b~ck from the outcrop. 

only slightly aff.ected. However, thin red · Although the rocks within a few feet of the 

bands may be formed by the baking of clay top of the burning bed may be partly fused, 

partings in the bed, and as these slump down those beyond are in general merely baked and 

they become curiously contorted and form, still further up are only_ slightly reddened. 

with white· bands of ash or cinders, a structure The great bulk-of the rock retains itsoriginal 

resembling somewhat that of a crumpled schist. texture, ·and though much of the shale is vitriPlate I,· B, shows a burning coal bed 11 .feet tied or hardened the sandy strata may be only 

thick exposed on Custer Creek, near Yellow- slightly affected. The most striking effect is 

stone River, between Miles City and Terry, the reddening of the rock, which is due to the 

Mont. To the left the bed is slowly burning action of moderate heat under conditions favbut has not perceptibly affected the overlying orable to simple oxidation and which theresandstone; to the right it is entirely consumed fore implies no very extensive chemical 

at the outcrop and the overburden has slumped changes. 

down irregularly. Though_ fusion is for the most part confined 

As the burning progresses back from the to the rocks directly above the burning bed, 

outcrop the heat is conserved and tends to act it may locally extend many feet above. The 

.more strongly -on the overlying rocks, until gases formed during combustion of the coal es.:. 

finally a point is reached where combustion is cape chiefly through ·fissures in the overlying 

smothered by the lack of oxygen. The under- strata and apparently are hot enough to fuse 

lying strata are scarcely affected, if at all, and the rock thoroughly along their paths of escape. 

in many places the coal does not burn entirely 

to the base of the bed. Baking and hardening 1 Bowie, Alexander, The burning of coal beds in place: Am.Inst. Min. Eng. Trans., vol. 48, p. 181, 1915. · 

of the overlying strata doubtless begin a few 2 Personal communication. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE I 

A. A CHIMNEY OR CORE OF HARD FUSED ROCK PROJECTING 

THROUGH PARTLY BAKED STRATA NEAR MILES CITY. 

Photograph by C. D. Smith. 

B. COAL BED 11 FEET THICK ON CUSTER CREEK NEAR YELLOWSTONE RIVER 

BETWEEN MILES CITY AND TERRY. 

To the left the bed is slowly burning but has not yet perceptibly affected the overlying strata; to the 

right it is entirely consumed, leaving only contorted white bands of ash and darker bands formed 

by the baking of clay partings. 

EFFECTS OF THE BURNING OF COAL BEDS IN EASTERN MONTANA. 

BAKED SHALE A~D SLAG FORMED BY BURNING OF COAL BEDS. 5 

As the melting point of silic.a is above 1,600° C., I oxygen, a considerable proportion . of carbon 

however, it is highly improbable that this ac- monoxide is probably for~ed, an~ If the rock 

tion is accomplished by the spent gases, the is ferruginous the reduCing, actwn may . be 

products of combustion, alone. It is reasonable very striking. Directly above the. burnmg 

to suppose that the coal itself becomes highly bed and along the paths. of the escaping gases 

heated, as well as the overlying rocks, and that the iron is partly or wholly :educed and gray, 

considerable distillation goes on a short dis- green, yellow, or black slag IS formed. When 

tance back of the burning face. According to the reduction is partial magnetite may be proBowie/ in the King mine, on North Fork of duced, in some places in sufficient quantity 

Gunnison River Colo. to affect the compass needle. When the rock 

' ' is thoroughly fused under reducing conditions, the coal adjacent to the burned-out area seemed to have 

its cohesive quality entirely destroyed. It was soft and however, a great deal of the ferrous iron formed 

very easily mined but could not be utilized even for steam is taken up in the formation of new minerals 

fuel as the volatile constituents of the coal seemed to and a light-colored slag results. A reducing 

hav~ been expelled by the heat. We had a zone of sev- atmosphere may also be developed in beds of 

eral hundred feet of this kind of coal. carbonaceous shale that are highly heated by 

It is probable that the gases arising through the burning coal bed, but most of the rock outfissures in the overlying rocks contain a consid- side of the chimneys is ·merely baked .under 

erable proportion of combustible matter, which oxidizing conditions to the characteristic redexplodes or burns on reaching a supply of dish color. 

oxygen, and that the intense heat necessary to 

fuse rock 7 5 feet or more above the bed is thus 

transmitted. 

PETROLOGIC CHARACTER OF THE ROCK~ 

FORMED. 

Apparently small fissures may control the CHARACTER OF THE ORIGINAL SEDIMENTARY 

paths of the gases and thus start the lormation ROCKS. 

of well-defined chimneys. As the material 

forming the immediate walls of the fissures 

becomes molten it tends to sink and clog the 

passage, so that the gases may be slightly 

diverted and thus be caused to act on_ a greater 

volume of material. A similar effect is produced when a fissured zone rather than a single 

fissure controls the escape of the gases. In this 

case, however, the heat is less concent.rated and 

may not be sufficient to melt more than the 

edges of the interfissural blocks. A single fissure may lead to the formation of a core of 

molten material extending many feet up 

through partly baked rock, whereas a fissured 

zone apparently produces a larger and less 

sharply defined core of partly fused fragments. 

On cooling, the fused or partly fused rock coheres and forms a roughly cylindrical mass of 

hard "clinker." Chimney-shaped masses of 

this kind resist erosion to a greater degree than 

the partly baked strata around them and 

weather to the curious pinnacles that commonly 

surmount clinker bluffs or buttes (Pl. I, A). 

Aside from the strictly thermal effects of 

the heated gases, they also play an important 

part as reducing agents. As the combustion 

of the coal takes place in a scanty supply of 

1 Bowie, Alexander, op. cit., p. 182 .. 

Although the degree of heat and the rapidity 

of cooling govern to a large extent · the general 

character of the materials formed, the fundamental factor is of course the composition of the 

original rock. The coal-bearing formations of 

the Western States are made up largely of shale 

and sandstone. The shale may be yellow, 

bluish or greenish gray, or brown and carbonaceous; less commonly it is reddish. The sandstone, which is usually gray, yellow, or brown, 

is generally more or less arkosic and may carry 

25 per cent or more of feldspar, hornblende or 

pyroxene, and mica. Under the microscope 

the rock from some localities or formations is 

seen to be made up of predominantly angular 

grains, and the feldspars and ferromagnesian 

minerals are surprisingly fresh. In other 

specimens, however, the grains are more 

rounded, the feldspars kaolinized, and the 

ferromagnesian minerals altered to chlorite or 

serpentine. Accessory mineralH, such as garnet, 

zircon, and magnetite, are present in most of 

the sandstone in minor quantity, and there is 

usually much fine clayey interstitial material, 

commonly iron stained. Some of the rocks 

examined, notably those of the Lebo shale 

member of the Fort Union formation (Ter-

·tiary), are evidently derived from fairly basic 
6 H RTER TRIB TI .. T E TER \ L 

inter 

y 1 17. 

mblino· lu 

f d 

allw 

n id rabl 

n ·tituting a 
j, 

BAKED SHALE AND SLAG FORMED BY BURNlNG OF COAL BEDS. 7 

minor facies of the metamorphic products. positive; - axial angle nearly 90°; dispersion 

The recrystallized material is generally, if not strong, and red greater than violet; extincinvariably, confined to the chimneys. As a tion angle 23°-25°; and indices of refraction 

rule it is gray to dark greenish gray, and exceP,t about 1.655 and 1.675. The mineral is pleofor its vesicularity is very similar in appearance chroic, deep yellow to apple-green. These 

to a fairly basic igneous rock. The grain is gen- properties indicate that it is not epidote and 

, erally fine, though in one specimen a crystal a suggest that it may be clinoenstatite. The 

tenth of an inch in diameter resembling pyrox- colorless mineral is biaxial negative in charene was observed. All gradations between acter, has a large axial angle, and has strong 

holocrystalline material and glassy slag may be dispersion, red being less than violet. Its 

found, and in most of 'the specimens examined birefringence is about that of quartz, and its 

a small amount of interstitial glass occurs. In refractive· indices are about 1.615 and 1.625. 

one slide remnants of the original quartz grains These properties suggest andalusite or some 

appear together with amorphous glass and form of wollastonite, though the mineral 

small, slender newly formed crystals. does not resemble either of these in habit. 

A specimen from Tongue River near the Two other minerals are present that could 

Wyoming-Montana line (T. 9. S., R. 40 E.) was not be identified. One is pleochroic, yellow 

studied under the microscope and found to con- to colorless; it is uniaxial negative in charsist chiefly of diopside and basic plagioclase. acter and its refractive indices are about 1.62 

The mineral called diopside has the following and 1.64. The other, which is not abundant, 

optical characters: Biaxial positive; axial angle is isotropic, colorless, and lacks cleavage; its 

. about 60°; dispersion weak with red greater index of refraction is about 1.61. In addition 

than violet; extinction angle, 36°; and in- the rock contains a basic labradorite, occurring 

dices of refraction about 1.675 and 1.702. The in small but well-twinned laths, magnetite, 

plagioclase has a maximum extinction angle of and a few grains of garnet, probably almandite. 

38° in microlites and refractive indices of 1.57 Several rounded xenoliths of shale · surrounded 

and 1.58, which indicate a basic labradorite or by contact rims of the yellow and white 

bytownite of the approximate composition minerals already described were observed. 

Ab1An3• As shown in the accompanying photo- (See Pl. III.)-

micrograph (Pl. II, B), the diopside crystals A specimen collected in T. 1 N., R. 36 E., 

have a tendency to form radiating groups, and not far from the one just described, appears 

the plagioclase occurs in well-formed laths to have been derived from a more highly 

and microlites. Some garnet, apparently al- aluminous shale. It is hnly partly recrystallized 

mandite, was observed, and magnetite in small and consists largely of glass, but acicular 

grains is fairly abundant. As near as can be crystals of sillim~nite (fibrolite) are abundant, 

ascertained the rock from which this material and several grains of what seem to be cordierite 

was derived is a sandy shale; consisting largely were observed. Spinel may be present but 

of kaolin, feldspar, and altered ferromagnesian could not be positively identified. Close to 

minerals, together with subordinate quartz and the chimney in which this mineral occurs a 

some calcite. mass of specular hematite about a foot in 

A sp_ecimen collected near the head of diameter was found. The hematite appears 

Sarpy Creek (T. 1 N., R. 37 E.) resembles' to be closely associated with the chimney, 

the specimen from Tongue River megascopi- although it lay rather in ijhe partly baked 

cally, but under the microscope appears to be shale through which the chimney projects. 

a very different rock. A larger number of This remarkable occurrence is discussed on 

minerals are present and the characters of the pages 9-10. 

most important of these do not correspond All the rocks described appear to be irreguwith those of any of the ordinary rock-form- lar in composition, and different portions of 

ing minerals. The rock consists largely of the same specimen may contain different 

greenish phenocrysts-at first sight suggesting minerals. It is probable that a detailed 

epidote-s.et in a mosaic of colorless grains study would reveal many more species, and 

resembling melilite. The optical characters some have indeed been reported by other 

of the green mineral are as follows: Biaxial observers. In slag~ from eastern Wyoming 
8 SHORTER CONTRIBUTIONS TO G,ENERAL GEOLOGY, 1917. 

Bastin 1 finds oligoclase, pyroxene, and cordi- Within the chimneys and d~rectly above the 

erite, in addition to magnetite and hematite. burning bed, where the rocks are fused under 

He describes a vein of slag about one-tenth of conditions favorable to reduction, more exan inch in diameter-penetrating red argillite tensive changes take place. The conditions 

as follows: . · · - are, of course, very different from those under 

In passing from th~ reddish argillite toward the center which igneous rocks are formed, and are analoi the vein the contact zone shows a gradual decrease ogous rather to those in the slag furnace. 

~n the .normal shale constituents and a development, in The pressure is low, mineralizing. agents are 

mcreasmg amount and coarseness, of purplish-blue b d 

pleochroic cordierite. Next the coars~r part of the a sent, an much of the water that the rocks 

vein this mineral is present to the exclusion of all others. contained is doubtless quickly driven off. 

In this contact zone the red iron oxide of the argillite The · material involved, however, is different 

has been wholly reduced to magnetite. The central from that which enters into the composition 

portion of t~e :e~n is a some~hatvesicular, holocrystalline of most furnace slags, being generally argilmass, conslAtmg of _ abundant magnetite in irregular 1 h 

masses, some hematite, usually lining the vesicles and aceous rat er than calcareous, and many of 

following fractures, and abundant cordierite, feldspar, the minerals formed are therefore probably 

and pyroxene. unlike those common in artificial slags. In 

Hibsch 2 has described similar material this connection the classic researches of V ogt 

from the Mittelgebirges (northern Bohemia) and Morozewicz, on prepared slags of known 

under the name Kohlenbrandgesteine. In the composition, are of interest. 

recrystallized specimens he finds magnetite, It is impracticable to correlate many pieces 

cordierite, epidote in well-formed crystals, of slag with the unaltered rock from which 

plagioclase, tridymite, , and abundant dark they _were derived, _ owing to the 'irregularity 

grains that may belong to the spinel group. in composition of the strata. Furthermore, 

unless fusion is very complete and the molten 

CHEMICAL CHANGES. mass is well mixed its mineral composition 

The· most widespread chemical change pro- may also be irregular. However, the diopsideduced in the overlying strata by burning coal plagioclase rock described above is e_vidently 

beds is dehydration under conditions favor- derived from a sandy shale, and after microable, to oxidation. This change affects chiefly scopic study a sample of this shale was analyzed 

the limonite and the siderite or other ferrous by the writer in the hope that the analysis as 

iron co-mpounds, which are converted into recast might explain the mineral character of 

hematite, with consequent reddening of the the slag. The composition of the shale is 

rock. Some of the hydrous silicates may be shown by analysis 1 in the accompanying table. 

partly or wholly dehydrated without ·fusion The sample analyzed had been partly baked,. 

under some conditions, but if this change which explains the ferric condition of nearly all 

takes place it is difficult to detect. In one the iron. The analysis accounts in a general 

specimen, however, the writer observed a large way for the mineral composition of the slag, 

fresh grain of green augite in a sandy shaie indicating rather high iron, lhne, arid magnesia. 

that had been baked but not fused. The According to Morozewicz, 4 diopside or heden_, 

augite could not be a product of s~condary bergite is formed in a slag in which the molec:-

crystallization, and all the other constituents ular ratio of Fe+ Mg : Ca is less than 3 : 1. 

of the rock were considerably altered. This This analysis shows a ratio of only 94 to 89,. 

suggests that it may have been re-formed by or if all the iron is calculated as ferrous, _ of 

the dehydration of alteration products, such as 140 : 89, and pyroxene of the diopside-heden-· 

chlorite or serpentine, though the writer is bergitc type is therefore to be expected. 

aware that such a process is not well supported According to the same investigator,5 augite is 

by"laboratory results.s generally forined when the melt contains 

more than 50 per cent of silica, and .though no 1 Bastin, E. S., Note on baked clays and natural slags in eastern 

Wyoming: Jour. Geology, vol. 13, pp. 408-412, 1')(}5. 

~ Hibsch, _J· E., Geologische Karte des bohmischen Mittelgebirges: 

Mm. pet. Mitt., vol. 27, pp. 35-40, 1908. 

3 Clarke, F. W., and Schneider, E. A., Experiments upon the constitution of certain micas and chlorites: U. S. Geol. Survey Bull. 113, 

pp. 27-33, 1893. 

augite was observed in this slag it might, if 

irregularly distributed, easily escape observa-· . I 

4 Morozewicz, Josef, Experimentelle Untersuchungen der M:inerale. 

im Magma: Min. pet. Mitt., vol. 18, pp. 113-128, 1898. 

5 Idem, P"?· 113, 120, 123-124. 
U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PI,..ATE Ill 

PHOTOMICROGRAPH OF HOLOCRYSTALLINE SLAG. 

BAKED SHALE AND SLAG FORMED BY BURNING OF COAL, BEDS. 9 

tion. The analysis, however, indicates a more 

acidic plagioclase than that found in the slag 

and suggests that an excess of silica would 

probably be left to crystallize as quartz or 

tridymite, which are apparently absent. These 

discrepancies are presumably due to irregularities in the composition of both the shale 

analyzed and the slag. 

Analyses of baked shale from Fort Union formation, Montana. 

[G. S. Rogers, analyst.] 

1 

Si02.----.-.-..................... 65.41 

Ti02 ••••••••••••••••••• ___ • _...... 1.17 

Al20 3 -- ••••••••••••••••••••••• _.. 11.94 

Fe20 3 •••••••••.•••••• _ •••• _. _____ •• 7. 38 

FeO ......... "·-------- _ ......... _ __ . 76 

MnO ....................................... . MgO ................ -----......... 1. 50 

CaO ............................ _ . 5. 02 

K20----------------...... .. . . . . . . . I. 96 

~:00~----~~--~:~~---------~:::: :::::::::: 2: ~~ H20+---------------------------·- . 50 

C02 •••••••••••••••••••••••••• _. _.. 1. 57 

803 •••••••••••••••••••••• · •••• _ • _. . · • 22 

P20s---------------.------- .. ----- Trace. 

100.34 

1. Sandy shale from upper Tongue River, T. 9 S., R. 40 E. 2. Clay shale from T. 1 N., R. 36 E. 

2 

58.30 

. 28 

20.50 

4.23 

.46 

. 18 

1. 31 

4.40 

2.28 

1.46 

1. 03 

1. 90 

3.37 

. 19 

Trace. 

99.89 

The third specimen described, containing 

sillimanite, cordierite, and probably spinel, is of 

interest as indicating the minerals that form in 

a m.elt more highly aluminous than any normal 

igneous magma. The composition of the shale 

from which this slag is derived is shown by 

analysis 2. The specimen analyzed had been 

moderately baked. It is uniformly fine grained 

and under the microscope appears to consist 

largely of clayey material together with a few 

grains of quartz and some calcite. 

The analysis indicates a slag similar in composition to some of those studied by Morozewicz/ who was able to formulate the conditions under which the several aluminous minerals form. If the molecular ratio of alumina 

is greater than the sum of the ratios of lime, 

soda, and potash, the magma is supersaturated 

with respect to alumina. If the general formula of the magma is written 1RO.mA120 3 .nSi02 

the following rules aP,ply: When magnesia and 

iron are very low, if n is less than 6 corundum 

will form, but if n is greater than 6 sillimanite 

will crystallize out. When magnesia and iron 

I Op. cit., pp. 22-83. 

are present in appreciable amount, if n is less 

than 6 corundum andspinel are produced, but 

if n is greater than 6 spinel and cordierite will 

form. Analysis 2 indicates the formula 

125R0.201Al20 3 .971Si02, or 1R0.1.6Al20 3 .-

7.7Si02; as m is greater than 1 and n is greater 

than 6 the melt is supersaturated with respect 

to alumina, and the alumina should form spinel, 

cordierite, and sillimanite. The sum of the 

molecular ratios of iron and magnesia is 64, or 

less than the difference between those of RO 

and Al20 3 • It may be supposed that cordierite 

and spinel would be formed until the magnesia· 

and iron were nearly exhausted, and that the 

balance of the alumina would then be consumed 

in the formation of sillimanite. Unfortunately 

the slag examined was incompletely crystallized, · and the order of formation of the minerals could not be determined. Cordierite is 

reported by both Bastin and Hibsch, and a 

mineral resembling spinel was found by Hibsch, 

which indicates that the aluminous silicates are 

probably common in the slags formed by the 

fusion of shales, and as magnesia and iron are 

generally present in considerable amount cordierite and spinel are doubtless more common 

than sillimanite or corundum. 

As already mentioned, a mass of hematite 

weighing several pounds was found close to the 

chimney from which the slag described above 

was taken. A partial analysis of the hematite 

is as follows: 

Analysis of hematite from T. 1 N., R. 36 E., Montana. 

[Chase Palmer, analyst.] 

Ferric iron (Fe20 3)............ • • • • • • • • • • • • • • • • • • 83. 57 

Sulphur (S) ...... , ............................ _ Traces. 

Chloride (insoluble) (Cl)---------------- .... _ .. __ Traces. 

Metallic iron (Fe) ......................... ____ . None. 

Ferrous iron (FeO) ....................... _,..... None. 

The origin of this mass of hematite is not 

easy to tmderstand. So far as the writer knows 

hematite has never been observed elsewhere 

in these flat-lying and only partly consolidated 

strata, and the specimen described must 

therefore have been formed in some way 

through the agency of the burnivg coal. It 

might be ascribed to the oxidation of a large 

pyrite or ironstone nodule, but a careful search 

failed to reveal any such nodules in the unaltered beds near by. On the other hand, if 

it is considered to have resulted from segregation during heating or fusion, the details of 
10 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

the process are very difficult to explain. As 

shown by analysis 2 (p. 9), the surrounding 

rock contains less than 5 per cent of iron, and 

rather extensive concentration would therefore 

have to be postulated. According to Vogt/ 

he~atite rarely occurs in ordinary furnace 

slags, as it can crystallize only when ferrous 

compounds are present in very subordinate 

amounts. In the surrounding rock ferrous 

iron is practically absent, but in order to 

. concentrate the ferric iron complete fusion 

would appear to be necessary,. and as this seems 

·always to take place under conditions favorable 

to reduction, much of the ferric iron would 

b~come ferrous. If the iron had occurred 

directly in the chimney as native iron, or even 

as magnetite, it might therefore be supposed 

that a smelting process akin to that in the 

ordinary blast furnace had taken place, but 

as it was found at the edge of the chimney and 

is completely oxidized to hematite this view 

does not appear to be tenable. 

A third hypothesis that might be suggested 

is that the hematite formed as it forms around 

volcanoes, through the decomposition of ferric 

chloride or sulphate by steam or heated air. 

The ground water of the region in which the 

hematite was found carries a considerable 

proportion of sodium chloride and of sodium, 

calcium, and magnesium sulphate, and as these 

salts are not uncommon as incrustations on 

1 Vogt, J. H. L., Beitrage zur Kenntniss der Gesetze der Mineralbildungin Schmelzmassen, pp. 215-217, 1892 

the rocks 3tn adequate supply of chloride or sulphate is undoubtedly present. On the assumption that hydrated ferric oxide (limonite) is 

capable of uniting with sodium chloride under 

the influence of intense heat, it seems probable 

that the ferric chloride so formed would ascend 

as vapor with the other gases and would be 

deposited as hematite in the upper part of the 

chimney. It is by no means certain that the 

primary reaction between disseminated limonite or siderite and soluble chlorides or sulphates is chemically possible under the conditions prevailing, but the presence of traces 

of basic (insoluble) chloride in the hematite is 

difficult to explain on other grounds and 

therefore tends to support this hypothesis. 

Native iron of secondary origin has been 

observed near coal beds in other localities. 

On North Saskatchewan River, 70 miles 

above Edmonton, Alberta, lignite beds have . 

burned -and have reduced the large clay ironstone nodules in the overlying strata to metallic 

iron, masses of which weighing from i5 to 20 

pounds have been found. 2 At three localities 

in Missouri drill holes have penetrated small 

masses of soft malleable iron in the sedin\entary 

rocks above coal beds,3 but the genetic relations of the iron and coal in this case are not 

so clear. 

2 Tyi-ren, J; B., Naturally reduced iron: Am. Jour. Sci., 3d ser., vol. 33, 

p. 73, 1887. . 

a Allen, E. T., Native iron in the coal measures of Missouri: Am. 

Jour. Sci., 4th ser., vol. 4, pp. 99-104, 1897. 

0 
DEPARTMENT OF THE INTERIOR 

FRANKLIN K. LANE, Secretary 

UNITED STAT.ES GEOLOGICAL SURVEY 

GEORGE OTIS SMITH, Director 

Professional Paper 108-B 

THE NEWINGTON MORAINE 

MAINE, NEW HAMPSHIRE, AND MASSACHUSETTS 

BY 

FRANK J. KATZ AND ARTHUR KEITH 

Published March 15, 1917 

Shorter contributions to general geology, 1917 

(Pages 11- 29) 

WASHINGTON 

G0VERNMENT PRINTING OFFICE 

1917 
CONTENTS. 

Introduction .................................. _. _ ............. _. __ ..................................... . General character of the region. _____ .. ~ _____ . __ .. ____________ . _____ . __ . _______ . _________ . __ . ___ . _ . __ ..... . 

Location and disposition of the moraine _____________________ ... _______________________________ . ____ . ______ . 

General character of the moraine _________________________________________ . ___________________________ . ___ _ 

Local details .. _____ ...... _____ . _______ ___ ____ ______ ____ ___ . _____ . ______________________________________ _ 

Saco segment .............. ___________________________________________________________ .. __ ........... . Biddeford segment. ___ __ . __ . _____ -_____ .______________ ____ ________________ ____ __ _ ____ __ _______ . _____ _ 

Kennebunkport segment. ____________________________________________________________ .......... __ ... . 

Merriland Ridge (Wells segment). ______ . ___________ . __ _ ... ___ . ____ .. __ .......... _ .. _ ..... ........... . 

Morainal deposits in South Berwick __ ... _____ . _________________________ . ___________ ·. ____ ... . ......... . 

Morainal deposits in Dover _____________ ______ __ ______________ .. __ . _ . ____ __ __ . _ . _____ ....... ......... . 

Newington and Portsmouth segment. _____ . __ . _____ .. ____ . ____ .. . _ ... _ ........... __ .. ...... . ......... . 

Rye, North Hampton, and Hampton segment. ____________ .. _____ _ ... _ . _ .............................. . 

Morainal deposits in Greenland. __ . _ .. ____ ________ .. ___________ ... .... __ ............................. . 

Hampton Falls, Seabrook, and Salisbury segment ... _._._ .. ___ .. _ ...................................... . Newburyport segment. __________________________________ _____ ___ __ _______ ____ ____________ __________ _ 

Observations by Upham ______ ... ___________ . _______________________________ . ________ .... __ ......... . 

Observations by Sears. _________ .. ________________ ___ ___ . __ __________________ . ________ ............... . 

Other ice-front deposits of the region. _______ .. __________________ . ___ ...................................... . Northward extension of the Newington moraine ________________ _ . _________ ___ __ ____________________________ _ 

Southward extension of the Newington moraine. ______ .. _. ________________________________________ . ________ _ 

Relation of the moraine to other Pleistocene formations. _____ ________ . ____ . _______________________ . ________ _ 

Roches moutonnees and till .. _____ . __________________ . __________ . ________________________ . __________ _ 

Marine sediments .. , .. __ . ___________________________________________ . _______________________________ _ 

Evidence that the moraine was laid down in the sea. _____________________________________ . ________________ _ 

Position of the moraine with respect to direction of ice movement. ___________________ ... ____________________ _ 

Recessional nature of the moraine. ________________________________________________________ . ______________ _ 

Discontinuity of the moraine ................ _____ ._ .. __ . ________________________________________ . _________ _ 

Age of the !lloraine ............ , . _ . _ ... _ . _____________ . __________ . ______ . ______ . ________________________ _ 

Summary ......... _ ... __ . ____ ._ ............ __ . _____________________________ . ____ . ______________________ . _ 

ILLUSTRATIONS. 

Page. 

11 

11 

12• 

13. 

14 

14 

14 

15 

15 

16 

16 

17 

20 

20 

21 

21 

22 

24 

24 

I 25 

26 

26 

26 

26 

27 

27 

28 

28 

28 

29 

PLATE IV. Map of New England coastal region from Plum Island, Mass., to Casco Bay; Maine .......... _....... 12 

·v. A, B, Gravel pit in Biddeford, Maine. ______________ ..... _...................................... 14 

VI. A, B, Merriland Ridge, Wells, Maine _____ ... ____ . ___ . _ .. _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 

VII. South side of railroad cut across Merriland Ridge, Wells, Maine. ___ . __ ...... __ ._ .. _ ............ _ .. _ 16 

VIII. A, West side of inner slope of Newington moraine on Bay Side road in Newington, N.H.; B, Sand 

pit in Pine Hill Cemetery, Dover, N. I-L __ . __ .... _. _ ... _ .... ____ : ............................. 17 

'IX. Map of parts of Newington, Greenland, and Portsmouth, N. H., and diagrammatic sections showing 

relation of the Newington moraine to rock and till and Pleistocene marine sediments............ 18 

X. A, B, Moraine gravel on New Road, Portsmouth, N.H............................................ 18 

XI. Wiggins gravel pit, Portsmouth, N.H. ___________ ._. __ ..................... _..................... 19 

XII. A, Gravel pit on Middle road, Portsmouth, N. H.; B, Gravels and sand, perhaps of kame origin, in 

Sunset Hill, Eliot, Maine _ . __ . ____ . _ ..... _ ..... __ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 

FIGURE 1. Diagrammatic section of moraine and outwash deposits of Merriland Ridge, Wells, Maine... . . . . . . . . . 16-

II 
THE NEWINGTON MORAINE, MAINE, NEW HAMPSHIRE, AND 

MASSACHUSETTS. 

By FRANK J. KATz and ARTHUR KEITH. 

INTRODUCTION. 

The present paper embodies the results of 

brief studies in 1915 and some earlier observations (1911-1914) on glacial and associated 

deposits in Maine and New Hampshire. It is 

preliminary in character, and the work was 

incidental to more extensive and detailed 

studies of the Pleistocene geology of southwestern Maine and vicinity, which will be the 

subject of later publications. 

The fact that a belt of gravelly and sandy 

ridges in southwestern Maine and adjacent 

New Hampshire has the character of a terminal 

moraine was recognized by the authors while 

they were together engaged in geologic reconnaissance. The moraine was first noted in 

Biddeford and Wells, Maine, and in Newington 

and Portsmouth, N.H. Mr. Keith traced the 

course of the moraine from Rye, N. H., to 

Newbury Old Town, Mass.; the portion in Newbury and Newburyport, Mass., had been noted 

by Sears. 1 Mr. Katz subsequently studied 

the moraine from Saco, Maine, to Rye, N.H. 

The late Prof. C. A. Davis was for a time in the 

field with the authors and contributed to the 

results here announced. His familiarity with 

the geography and geology of the region about 

Portsmouth was of assistance in tracing the 

moraine. 

Earlier geologic writings that are of interest 

as discussions of Pleistocene geology of the 

same region are limited to three-Warren Upham's chapter, "Modified drift," in Hitchcock's 

"Geology of New Hampshire," volume 3 ; J. H. 

Sears's "Geology of Essex County, Mass.," 

cited by full title below; and F. G. Clapp's 

"Complexity of the glacial period in northeastern New England. " 2 

1 Sears, J. H., The physical geography, geology, mineralogy, and 

paleontology of Essex County, Mass., pp. 296,301, map, Essex Institute, 

Salem, 1905. 

• 2 Geol. Soc. Amerjca Bull., val. 18, pp. 505-556, 1907. 

The name here adopted is taken from the 

town of Newington, N.H., in which the moraine 

is characteristically developed and forms a 

prominent topographic feature. The time of 

the Newington moraine will be designated the 

Newington substage. 

GENERAL CHARACTER OF THE REGION. 

The region in which the Newington moraine 

is situated is a coastal lowland from 12 to 20 

miles wide, bounded on the landward side by 

an upland that rises inland by a series of thoroughly dissected rock platforms or terraces. 

The coastal lowland, which also includes several similar but lower terraces, is a hilly, 

heavily drift-mantled rock surface, rising from 

below sea level to about 300 feet above sea 

leveL The rock floor of this terraced surface 

is thoroughly dissected into ridges separated 

by wide, open valleys, some of which are in 

part worn to depths below the present sea 

level. Some ridges, for example the Bauneg 

Beg Ridge, project from the upland terraces 

into the lowland area, and some monadnocklike rock hills or outliers of the higher terraces, 

notably Mount Agamenticus, rise above it. 

The entire region has been rigorously glaciated and abundantly supplied with glacial 

deposits of many kinds. During part of the 

glacial epoch the coastal terraces were submerged beneath the sea, but since . then they 

have emerged. During the period of subsidence 

marine clays and sands were deposited in the 

depressions, and these deposits are now to be 

seen as broad, flat areas only slightly dissected 

by a very young drainage system. Davis 3 has 

shown that" The present shore line is therefore 

not the direct result of submergence of a rugged 

land, but of the emergence of an uneven sea 

3 Davis, W. M., Physiography, in Grabau, A. W., and Woodman, 

J. E ., Guide to localities jllustrating the geology * * * of the vicinity 

of Boston, p. 5, Am. Assoc. Adv. Sci., 1898. 

11 
12 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

bottom-uneven because the marine clays that 

were spread upon it had not been deposited in 

sufficient quantity to smooth over its previous 

inequality." 

The glacial and marine deposits have modified and in general softened the relief of the 

region and have deflected many of the streams 

from the preglacial rock . valleys. N evertheless, the general trend of the principal drainage 

lines is now, as formerly, southerly to eastsoutheasterly. The marine deposits increase 

in breadth and thickness and indicate greater 

submergence toward the north and northeast. 

The surface of these deposits now slopes southeastward (toward the sea), and, furthermore, 

the broad plains of marine clay and sand lie 

at higher elevations in the northern part of the 

region than in the southern part. There appears, then, to have been some tilting. These 

relations, however, may be in part explained as 

due to differences in the degree of filling caused 

by differences in the quantity of material discharged into the sea at different localities and 

in the distance of the several localities from 

the shore line and the sources of the materials. 

The Pleistocene marine sediments of this region 

and the associated problems of coastal movements and delineation of shore lines are now 

being studied. 

LOCATION AND DISPOSITION OF THE MORAINE. 

The drift formations here considered are distributed along a sinuous 60-mile course in York 

County, Maine, Strafford and Rockingham 

counties, N. H., and Essex County, Mass.t 

They lie nowhere more than 9 miles from the 

present Atlantic coast and in some places are 

adjacent to tidewater. Their distribution is 

shown on the accompanying map (Pl. IV). 

The moraine does not form a continuous 

ridge but is made up of a number of segments, 

more or less widely separated by intervals in 

which no deposits belonging to a terminal moraine have been found. Nevertheless, there is 

a conspicuous alignment of the segments, as 

displayed on the map (Pl. IV), which supports 

the conclusion tliat all are parts of the same 

moraine. The arrangement and extent of the 

several segments and intervals are as follows: 

1 This region is represented on the following maps of the United States 

Geological Survey's topographic atlas: Portland, Biddeford, and Kennebunk, Maine; Berwick and Dover, Maine and N.H.; and Newburyport, N.H. and Mass. All these maps, except that of the Portland quadrangle, are of reconnaissance grade, and therefore too much generalized to 

bring out features like those described. 

Beginning at the north, the first is the Saco 

segment, in the western part of the city of Saco, 

Maine, on the north bank of Saco River just west 

of Deep Brook. It is a little less than a quarter of a mile long and trends southeast. Between the Saco segment and the next one, the 

Biddeford segment, is a short interval occupied 

by Saco River and its flood plain. The Biddeford segment has its north end south of the 

Saco segment, on the south side of Saco River, 

in Biddeford, and extends south-southeast for 

nearly a mile, and thence west of south along 

the west side of the post road for 1 t miles, 

finally turns southwestward and ends near the 

granite hills in the southern part of the town 

of Biddeford. Beyond an interval of 1 t miles 

to the southwest, across granite hills, is the 

next ;:;egment, the Kennebunkport, which is a 

ridge 1 t miles long with SOUtJllWest trend. 

About 7 miles to the southwest, across Kennebunk, Mousam, and Branch rivers and the 

flat lowlands adjoining them, is the Wells segment or Merriland Ridge. This ridge has a 

sinuous course about 7 miles long, trending 

south for a mile, then swinging westward and 

finally southwestward and terminating about 

2 miles east of North Berwick village, against a 

massive hill of granite. About 2! miles southwest of this point there is a small area of probably morainal sands and gravels. Two miles 

farther south is the Knights Pond segment, 

a crescentic ridge inclosing the southeast end 

of Knights Pond, in the northwest corner of 

the town of South Berwick. The succeeding 

interval, measured to either the Dover or the 

'Dover Neck segment, is approximately 8 miles 

across areas of ground moraine (till), marine 

clay and sand, and rock ledges. 

The Dover segment, including Pine Hill 

Cemetery, in the city of Dover, is an irregular 

area from half to three-fourths of a mile wide. 

This is separated by an interval of clay plain 

and till-covered rock hills, 1 mile wide, in a 

southeast direction from the Dover Neck segment, which is a north-south ridge 2! miles 

long between Little John Creek •on the north, 

Dover Point 011 the south, and Piscataqua and 

Bellamy rivers on the east and west, respectively. Across Little Bay, 1 n1ile south of the 

end of the Dover Neck ridge, is the north end 

of the Newington and Portsmouth segment, 

which extends south about 2! miles along or 

near the eastern shore of Great Bay, thence . 

east three-fourths of a mile to Newington Town 
U. S. GEOLOGICAL SURVEY 

. oon I ~ 

~ 

~ 

~ 

0 

PROFESSIONAL PAPER 108 PLATE IV 

LEGEND 

Outwash sand and gravei 

Mora1ne!; 

l7l 

~ not correlated with the Newington, and gravel and sand ridges, possibly morainal 

Clay and 

.. 

sand horizontaliy strati- . fied1 containing a marine fauna and · equivalent in age to outwash sand and gravel contemporaneous with and younger than. the Newington morame 

Rock "anchors" against which the moraine is.deposited 

Blank areas chiefly rock and ground moraine 

6ealogy .e,v F. J.Ka.tz and A .Keith 

MAP OF NEW ENGLAND COASTAL REGION FROM PLUM ISLAND, MASS., TO CASCO BAY. MAINE, SHOWING 

DISTRIBUTION OF MORAINE AND OUTWASH DEPOSITS. 

NEWINGTON MORAINE, MAINE, NEW HAMPSHIRE, AND MASSACHUSETTS. 13 

Hall, southeast 3 miles to Portsmouth Plains, 

south 1 mile to Peverly Hill, and south into the 

swamp along Berrys Brook. The part of the 

moraine 'between Newington and Peverly Hill 

is shown on Plate IX (p. 18). The Rye, North 

Hampton, and Hampton segment, beginning 

south of Berrys Brook opposite the end of the 

Newington and Portsmouth segment, extends 

west-southwest through Rye Center and West 

Rye 2 miles to Breakfast Hill, south and west 

of which, in North Hampton, morainal deposits 

are irregularly distributed over a broad area of 

several square miles. North of this area, in 

the town of Greenland, is an outlying moraine 

ridge 1! miles long from north to south. From 

North Hampton the moraine continues southward through Hampton village into Hampton 

Marsh, north of Taylor River. The Hampton 

Falls, Seabrook, and Salisbury segment begins 

in Hampton Falls, It miles southwest of the 

preceding segment, and extends south and 

south-southwest through Seabrook and Salisbury to Merrimack River. The Newburyport 

segment begins in Amesbury and runs southeast across Merrimack River and for 7 miles in 

a nearly straight course into Newbury village, 

whence it extends south-southwestward for a 

short distance to Parker River. The moraine 

has not been traced beyond this point. 

The above-outlined disposition of moraine 

segments indicates that the ice front of the 

Newington substage from Saco, Maine, to Newbury, Mass., a distance of 59 miles, had a gen-

, eral south-southwest course, though it was not 

straight. From Saco through Wells ' the line 

indicated by the segments was nearly 15 1niles 

straight southwest. Beyond Wells, through 

North Berwick and South Berwick, Maine, and 

Rollinsford and Dover, N. H., the front was 

bowed 2 miles westward through another 

stretch of 15 miles around the Mount Agamenticus mass, which was a barrier to eastward ice 

movement. From Dover it swung southeasterly for 8 miles through Newington and Portsmouth into Rye, being herd south of Piscataqua 

River, probably by the influence of both the 

Agamenticus highland and the Piscataqua estuary. This southeasterly stretch and the succeeding west-southwesterly course of 4 miles in 

Rye and North Hampton outline a small lobe, 

caused by the Great Bay depression. From 

North Hampton the general course of the ice 

front was south-southwest for 11 miles to Merrimack River, with a slight easterly bowing. 

South of Merrimack River its course has been 

traced for 2,bout 8 miles in a southeasterly 

direction, determined by the river, from Amesbury to Newbury Old Town. I 

GENERAL CHARACTER OF THE MORAINE. 

The Newington moraine is a ridge ranging in 

height from 40 to 100 feet above its base and 

in width frmn a few rods to a mile or more. 

It consists of· a western inner or ice-con tact 

slope, the summit or moraine crest, and in 

some places an outer sTope with which is associated an outwash apron. These parts are 

not everywhere distinct. The inner side is 

generally steep, rising abruptly the full height 

of the moraine from ground moraine or marine 

clay plains. The crest, whether narrow or 

broad, is nearly everywhere flat and approximately level. It is hummocky in only a few 

places, nowhere markedly so. It does not 

exhibit the typical knob and kettle form of 

kame moraines, nor the rough surface of till 

and boulder moraines. Where kamelike forms 

have been developed, as in Newburyport, 

Kennebunkport, and Dover, and locally in 

.Newington and Portsmouth, they are small and 

subdued in form and relief. As a rule, kettle 

holes are few, isolated, and small. In Newburyport and North Hampton, however, there 

are groups' of good-sized ones. Where the 

moraine does not lie against rock hills the 

outer side is a moderate slope descending to 

clay plains or merging into an outwash apron 

or else a low scarp between the outwash and 

the moraine crest. Outwash plains were not 

formed everywhere, and some of them are not 

distinct frmn the moraine. They are smooth 

gentle slopes a few rods to It miles wide and 

locally pass gradually in both slope and constitution into broad flats of marine clay and sand. 

Within a moderate range the moraine ascends and descends with the relief of the floor 

upon which it stands. Thus it rises 011t of the 

valley of Saco River upon the small rock hills 

in Biddeford and descends again into the 

valley of Kennebunk and Mousam rivers. In 

Wells and South Berwick it attains its greatest 

elevation of about 200 feet on the flanks of a 

large obstruction of high ground. Southwest 

of this locality it descends to sea level in Pis-
14 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

cataqua River. However, ·the maximum difference in altitude of different parts of the 

moraine does not exceed 200 feet. 

The materials of the moraine are boulders 

gravel, and sand. With the exception of som~ of those at one place, all the boulders and 

pebbles o.bserved are foreign to the locality of 

the morame. A very small amount of strati-· 

fied clay has also been noted in the moraine 

but no till has been identifi~d in morainal de~ posits of typical Newington form. Bo~lders 

are not abundant as a rule but have been found 

in considerable numbers in the north end of 

Merriland Ridge, Rye Center, and Greenland. 

Gravelly sand and gravel made up of large 

cobbles, small pebbles, and sand predominate 

in the moraine. These materials are all more 

or less washed and water-rounded. The outwash mat~rials are gravel and sand, dominantly 

of small Size, and are progressively finer toward 

the farther limit of the outwash. 

The moraine has in many places a welldev~loped internal structure consisting of a 

sortmg and stratification approximately parallel to the cross profile of the moraine. Beds 

~hat are nearly flat in the center dip outward 

mto and constitute the proximal part of the 

outwash plain. In several places in Biddeford 

Newington, and Portsmouth the inner side of 

the ~oraine is made up of. beds dipping strongly 

and In part parallel to the surface slope. These 

"backset" beds are well developed in the 

bro~der parts of the moraine and were deposited 

dunr:g slow retreat of the ice. In places in 

Newmgton the moraine contains structureless. 

unsorted sand and gravel. Irregularly dis~ 

tributed patches of sand and gravel were noted 

in Saco and Portsmouth. 

LOCAL DETAILS. 

SACO SEGMENT. 

The moraine in Saco is very narrow and inconspicuous; it consists of aligned sandy 

knolls almost covered by the sur.rounding clay 

and sand plain. The ridge extends northwest 

toward a till-covered rock hill, from which it is 

separated by nearly half a mile of horizontal 

sand plain. In two pits marin~ clay and overlying sand lie above the moraine material 

which consists of waterworn sand, gravel, and 

boulders, not stratified but in pell-mell structure. Pebbles of moderate size predominate, 

although there are also numerous large boulders. 

The materials in these pits are not weathered. 

BIDDEFORD SEGMENT. 

Opposite the Saco segment is the north end of 

the Biddeford segment, also covered by clay. 

A b:oad mound of stratified sand overlain by 

marine clay on the north side of Main Street 

Biddeford, is the northernmost recognizabl~ part. Thence the moraine continues southeastward, rises above the clay as a gravel 

cover on the south-southwest slope of the 

rocky hill in the center of the city, and extends 

as far as Elm Stree-t (the post road), where it 

forms a flat-topped sand plain that on the 

east in part abuts against higher granite hills 

and in part grades into a clay plain. From 

this plain the moraine narrows to an evencrested ridge which trends southwest on the 

west side of the post road for about a mile. 

This ridge is 160 to 180 feet above sea level 

J ' and from it the descent to the northwest is 

moderately steep for about 50 feet to a low 

area floored by rock ledges, ground moraine, 

and marine clay. On the southeast side, however, the ridge is only locally marked off by 

a low scarp and slight change in slope from the 

bordering sandy outwash plain, which slopes 

gently southeastward and merges into a clay 

plain. The difference in slope and altitude 

between the two sides is a most striking feature 

in a view from the top of the moraine. From 

the post road the morame turns westward and 

decreases in height. It trends toward the 

granite hills on the edge of the town of Kennebunkport but ends at the low pass immediately east of those hills~ 

The make-up of th~ Biddeford segment is 

disclosed in a number of gravel pits and sand 

banks from which material is taken for railroad, highway, and construction work in and 

around Biddeford. Two cuts on the summit 

and the large gravel bank worked by the railroad on the northwest side of the high ridge 

along the post road show that the material is 

made up of gravel and boulders packed in a 

sandy matrix without sorting or stratificatiQn 

and at least in part lying on granite ledges. 

The material is all more or less waterworn and 

rounded, and in the summit cuts it is iron 

stained and partly rotted. A sand pit near 

the junction of the post road and the Alfred 

pike, near the moraine border of the outwash 

plain, shows 20 feet of stratified and approximately horizontal sands. Pits in the northwest slope of the ridg:e and on the north side 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE V 

A. UPPER PART OF PIT. 

Shows 15 feet of rudely stratified moraine gravel. 

B. LOWER PART OF PIT. 

Well-stratified sand and gravel on inner slope of moraine. These sands are overlain by the gravel 

shown in A. 

GRAVEL PIT IN BIDDEFORD, MAINE. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE VI 

A. 

B. 

MORAINE FRONT AND OUTWASH, MERRILAND RIDGE, WELLS, MAINE. 

In the upper view the moraine front is fairly smooth and not sharply separated from the outwash. 

In the lower view the moraine is scalloped and more sharply s eparated from the outwash. 
NEWINGTON MORAINE, MAINE, NEW HAMPSHIRE, AND MASSACHUSETTS. 15 

of the Alfred pike expose 15 to 20 feet of sand the moraine springs from the south side of the 

and gravel. (See Pl. V.) This material is granite hills, against which on the north the 

for the most part stratified and sorted, although Biddeford segment terminates. On the east, 

but poorly sq, and the beds dip strongly 35°- north, and west the Kennebunkport segment 

45°W.-thatis,theyare"backset"beds. The is bordered by wide plains of marine clay and 

pebbles and boulders, the latter not uncom- sand. These deposits fill the valleys of Kennemonly 2 feet and rarely 3 feet in diameter, are bunk, Mousam, and Branch rivers, and exalmost all rounded. Although some of them cept for detached protuberant hillocks of 

are somewhat polyhedral, like faceted pebbles rock and ground moraine they bury ali other 

or soled boulders, they have been so much formations. It is 7 miles south-southwest 

rounded off that plane surfaces, other than across these filled valleys, in which no terminaljoint or cleavage faces, are scarce. In these moraine deposits have been found, from the 

exposures beds of sand or small pebbles con- Kennebunkport to the next segment. 

taining a few scattered larger pebbles are overlain by gravel beds containing 4 to 6 inch MERRILAND RIDGE (WELLS SEGMENT). 

cobbles and many boulders. In all the gravel The moraine of Merriland.Ridge is terminated 

beds there ·is a closely packed matrix of sand at both ends by granite hills. The north end 

and small pebbles. springs from a small, low granite knob on 

The prominent part of the Biddeford seg- Merriland River, in the town of Wells, about 

ment is the ridge along the post road. The 2 miles above the mouth of the river. From 

southwest end of this ridge, which is low and this rock knob the moraine extends southward 

inconspicuous, trends toward and terminates for a mile as a generally flat but in a small 

near rock hills that are higher than any part way hummocky area one-fifth mile to 1 mile 

of the moraine. The northeast end of this broad. Over this area are scattered numerous 

ridge lies against the higher rock ledges in the large boulders, which, however, are more 

city, and the morainal gravels and sands con- abundant on the western part of the broadest 

tinue to the north as a cover on the flank of portion; the eastern part has fewer boUlders 

these l~dges. The northern part of the Bidde- and is more sandy. Southwestward from this 

ford segment and the Saco segment connect broad, flat part the moraine is narrower, higher, 

rock hills on both sides of Saco River. It is and more sharply ridgelike, and from a point 

clear that these rock hills determined the form about 1! miles north of west of Wells Beach 

and position of the ice front and that the low station through a distance of 3! miles westground between them was the site of the dis- southwest the moraine is a prominent s!gmoid 

charge of the glacial drainage of Saco Valley. ridge which rises abruptly 40 to 50 -feet above 

Between the Biddeford and Kennebunkport low and wide meadows on the northwest. (See 

segments is an interval of 1-! miles occupied Pls. VI and VII.) Through this distance it 

by hills of granite that stand about 50 to 100 has a nearly level and generally smooth or 

feet higher than surrounding areas. These . gently undulating crest, at an altitude of about 

hills for the most part are bare rocks, but in 200 feet above sea level. The crest is in some 

places they have a drift cover, no part of which places only a few rods in width and in others 

has yet been recognized as belonging to a several hundred yards. The southeast slope of 

terminal moraine. this part of the ridge is short, 10 to 20 feet 

KENNEBUNKPORT SEGMENT. 

The Kennebunkport segment is a narrow 

southwestward-trending ridge 1~ miles long 

and for the most part only 30 to 100 rods wide, 

though it widens to nearly three-quarters of a 

mile at. its southwest end. It is made up of a 

number of coalescent sandy kamelike k:Q.olls 

and includes in its higher and broader southern 

part a few small rock ledges. This segment of 

high, and steep. It is in places somewhat irregularly scalloped or ribbed and breaks sharply 

into a very gently sloping outwash apron of 

gravel and sand. In other places this southeast slope is smooth and merges gradually into 

the outwash apron. (See Pl. VI.) 

The moraine is prolonged 1! miles farther 

west, retaining its sharp ridge form. In this 

stretch it approaches the nearly parallel north 

slope of a large granite hill, against which it 
16 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

ends at a point about 2 miles east of North 

Berwick village. Through this end of the 

moraine some ledges of granite protrude. 

The materi,al constituting the northern part 

of this .moraine is largely bouldery gravel. 

Elsewhere, as seen on the surface, it is chiefly 

sand and gravel of moderate size. The only 

· section found is the railroad cut through Merriland Ridge, the south bank of which is shown 

in Plate VII. The height of this section is 

about 35 feet. The material in it is stratified 

small gravel and sand, with a little clay and 

·relatively few small and large boulders. The 

attitude of the beds, which is faintly indicated 

in the photograph, is in approximate parallelism with the front or east side of the moraine. 

The bedding has a low easterly dip under the 

outwash plain and rises to a greater inclination 

under th'e crest, and then with lessened dip the 

beds are cut off at the back slope. This attitude is shown in figure 1. The clay seam, 

territory north and west disclosed no morainal 

deposits, but in South Berwick, at 2! miles 

southwest of the end of the Merriland Ridge 

segment and on the west flank of the rock hills, 

was found the feature next described. 

MORAINAL DEPOSITS IN SOUTH BERWICK. 

In South Berwick, 1! miles southeast of 

North Berwick village, there is a small area of 

sand and gravel that fills a saddle between rock 

hills. No distinctly morainal features were 

noted here, but the position of this drift and its 

similarity in character to the drift of Merriland 

Ridge are suggestive of morainal origin. In 

189~ Leonard H. Davis 1 regarded this drift as 

a moraine. 

Three to four miles southwest of this area 

of ~;;and and gravel is the ridge inclosing the 

south end of Knights Pond. This ridge is a 

crescentic belt, · convex to the south, of small 

contiguous sand and gravel knolls which preMoraine crest 

FIGURE l.-Diagrammati9 section of moraine and outwash deposits of Merriland Ridge, Wells, Maine, showing the structure of the moraine. 

visible as a dark streak at about the center of 

the section in the photograph, thickens very 

slightly eastward out to the limit of its exposure, and on the west it thins and is replaced 

by coarse sand. In appearance and composition this clay is very much like the marine 

clay of the region in general. The entire outwash apron along this part of the moraine 

slopes down to and grades into the low, flat 

sand . and clay plal.ns about the headwaters of 

Webhannet River. 

· The continuation of the moraine was not 

sought in a southerly direction from the end 

of Merriland Ridge, because rock hills that are 

very much higher, culminating in Mount Agamenticus, 692 feet in altitude, extend for many 

miles southward and occupy a large area in 

the towns of Wells, South Berwick, and York. 

The westward swing of Merriland Ridge at 

Jlearly constant level against and around the 

north side of this high rock mass indicates that 

during the Newington substage the ice did not 

ascend these hills. A reconnaissance of the 

sent a continuo·us smooth, even slope toward 

Knights Pond. There are no well-exposed 

sections in this ridge., and consequently its 

form and position with respect to the pond are 

the only evidence of its morainal character. 

From ICnights Pond to Dover, 8 miles southwEst across the valley of Salmon Falls River, 

there are no known terminal moraine deposits. 

MORAINAL DEPOSITS IN DOVER.. 

'Pine Hill Cemetery, in Dover, N. H., is on a 

roundish kamelike hill 150 feet above sea level, 

or 60 to 70 feet above the adjoining plains of 

marine sediments. The hill extends east half 

a mile to a higher rock ridge and has a sloping 

southerly extension of 0.4 mile. A small 

rock ledge protrudes through gravels and sand 

0.1 mile southeast of the summit of the hill. 

The higher central part of the hill is cmnposed 

of unsorted gravels of moderate size in a sandy 

matrix. A gravel-and sand pit in the cemetery, 

near the eastern limit of the kame area, ex1 Unpublished notes filed in the U. S. Geological Survey. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE VII 

SOUTH SIDE OF RAILROAD CUT ACROSS MERRILAND RIDGE, WELLS, MAINE. 

Stratified gravels, sand, and clay constitute the moraine and outwash. 
U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE VIII 

A. WEST SIDE OF INNER SLOPE OF NEWINGTON MORAINE ON BAY SIDE 

ROAD IN NEWINGTON, N. H. 

The flat surface in the foreground is sandy marine clay. 

B. SAND PIT IN PINE HILL CEMETERY, DOVER, N. H. 

Shows irregularly bounded beds and pockets of sorted sands and fine gravel. 
NEWINGTON MORAINE, MAINE, NEW HAMPSHIRE, AND MASSACHUSETTS. 17 

poses 15 feet of sandy material and has not cut 

through to the bottom. Plate VIII, B, shows 

a part of this section. Sand and fine gravel are 

very irregularly interspersed throughout the 

exposed section except at the top, which is 

clayey and more evenly layered; small gravel, 

in which the pebbles are less than h~lf an inch 

in size, is more abundant toward the bottom. 

All the material is to some extent stratified, in 

general unevenly so, and as a rule the coarser 

material is the more uneven. The photograph 

brings out the irregular but sharp boundaries 

of the various kinds and grades of rna terial. 

This is distinctly kame structure. Upham 1 

refers to "the kamelike plain" of Pine Hill 

. Cemetery and implies a connection between it 

and the sand and·gravel plains north of Dover, 

. which, however, are now believed to be out-

,wash deposits of a later stage. 

About 2 miles southeast of Pine Hill is the 

north end of the Dover Neck Ridge. This 

ridge is 21 miles long, three-quarters of a mile 

wide, and 100 feet high near its north end, half 

a mile wide and 130 feet high 1 mile farther 

south, and about 100 yards wide and 40 feet 

high at its south end. The ridge is nearly 

symmetrical except in the broadest northern 

part, where the crest is nearer the west side 

and the eastward extension has the form of an 

outwash plain. The surface of the ridge is for 

the most part smooth, although in places it is 

very slightly hummocky. The rna terial seen 

on the surface and also in small openings is 

gravel and sand. There are thin interstratified 

seams of sand and clay covered by small gravels in a cut near the summit, and near by is a 

small ledge of slate. On the sides are variously inclined sand beds which appear to grade 

toward and are not topographically distinct 

from the marine clay that fringes the ridge. 

The eastward expansion at the north end is a 

sandy plain that slopes toward and merges into 

a flat plain of marine clay. · 

NEWINGTON AND PORTSMOUTH SEGMENT. 

The moraine has been more carefully studied 

in Newington and Portsmouth than elsewhere. 

Its form and constitution in those towns are 

described below. 

Beginning on the shore of Little Bay east of 

Fox Point, the moraine extends 1.1 miles 

I Upham, Warren, in Hitchcock, C. H., The geology of New Hampshire, vol. 3, pt. 3, p. 153, 1878. 

across Fox Point and south along the shore, 

rising abruptly to a height of 40 to 60 feet to a 

narrow ridge at about 500 -feet from the bay. 

A recent sea cliff 25 feet in height has been cut 

along part of this slope. The eastward descent 

is gradual and smooth through one-eighth to 

one-fourth mile to the level of the bay, or to 

flat plains of marine clay approximately 20 

feet above sea level. The materials making up 

this ridge, as shown in cliffs on the shores and 

gravel pits on the crest, are sand and abundant 

well-rounded gravel, generally of moderate 

size but grading from small pebbles to large 

cobbles and containing also a few boulders. 

However, in the north end, where the moraine 

directly overlies slaty rock, many angular 

fragments of that rock are mixed with the 

gravels. South of the above-described section 

the moraine is very much broadened, owing 

to the east-southeasterly trend of its outer 

(easterly) border, whereas the inner margin 

continues southward for 1 ~ miles. The principal axis or· crest of the moraine in this part 

curves from a southward to a nearly eastward 

trend toward Newington Town Hall. In the 

part where the greatest width is nearly a mile 

the height of the moraine is 60 to 80 feet and the 

surface is hummocky, being composed of small 

kame knobs and kettles. The rna terial here 

is gravel and sand, dominantly sandy on the 

surface, and unsorted gravels and sand were 

seen in one pit. From Newington Town Hall 

the moraine trends east of south 1 k miles along 

the Greenland road to Gosling Road. Its 

width is half to three-quarters of a mile, and its 

top is broad and flat and stands at an elevation 

of about 100 feet. The descent to the west is 

fairly steep and about 20 to 30 feet high (Pl. 

VIII, A), but the eastward descent is less in 

amount and gentle. N ea.r the town hall a rock 

ledge included in the moraine makes two small 

outcrops. Elsewhere the surface is sandy and 

bears a few boulders. Unassorted sands, 

rounded gravels, and small boulders are exposed in a bank west of the town hall. 

Plate IX shows the position and outline of the 

moraine from Gosling Road in Newington to 

Peverly Hill in Portsmouth. The westerly 

boundary of the moraine in this length is sharp 

and marked by an abrupt change in slope. 

In places, particularly near New Road and at 

Peverly Hill, the morainal gravels present to 

the west steep walls and buttn~ss-like forms 
18 SHORTER CONTR.IBUTIONS TO GENERAL GEOLOGY, 1917. 

'that could have been made only by accumula- Along l\1iddle Road the moraine trends easttion of the gravels against a retaining mold- ward and is rather lower than the parts already 

the ice front. In two places, however, at the described. Here its surface is composed of 

inner margin of the moraine there are flat or irregular knolls of small size. Its limits are 

nearly flat-lying sands and gravels, which sharply defined against rock, till, and clay surare not distinctly separated from morainal faces on the south and a clay meadow on the 

materials on the one side and from low clay north. Portsmouth Plain-s is a flat expanse of 

plains on the other. Although the exact sands and gravels making the crest of the roonature and origin of these sandy flats has not raine, which north and east of Portsmouth 

been determined, it seems probable that they Plains abuts against rock hills. 

:are the result either of deposition in small From Portsmouth Plains the moraine exbodies of water ponded between the moraine and tends southward for about a mile t'o Peverly 

the ice after the ice had locally melted away Hill. In that distance it is comparatively low 

from the moraine, or else of reworking and and narrow, and north of Sagamore Creek is 

redeposition of the morainic materials by rna- made up of small knobs of sandy gravel includrine· waters that flooded the region after the ing a small, shallow, circular kettle. South of 

withdrawal of the ice. the creek the moraine is a flat-topped bench of 

The summit of the moraine is about half a gravel and sand about 40 feet in elevation, lying 

mile wide along Gosling Road, is smoothly against the rock :t;nass of Peverly Hill. In one 

level, sloping inappreciably east, and grades place through a length. of 100 feet or more the 

into a narrow eastward-sloping outwash apron. flat top of the plain does not quite reach the 

South of' Gosling Road the moraine is both rock, there being a small and shallow depresnarrower and lower and is not distinct from sion or ''foss" between them. The flat gravel 

outwash on the east and a flat sandy plain on bench · extends along the northwest side of 

the west. Farther south, however, it rises Peverly Hill and is continued eastward in a 

to a flat gravelly top 90 feet in elevation and 0.4 plain that surrounds the hill and descends by 

mile wide on New Road. Here it has a steep moderate slopes northward into the Sagamore 

west side, rising 50 feet out of a clay meadow, Creek marshes and by gentle slopes eastward 

and a . sinuous east border marked by a low to rocky hills east of Lafayette Road. The rooscarp between the moraine and its outwash, · raine extends as a broad, smooth ridge of gravel 

near which it is pitted by a few small kettle southward from Peverly Hill across Lafayette 

holes. The flat top is continuous from New Road to Belly hack Swamp (Berrys Brook). 

Road southeast to Middle Road, a distance of Gravel and sand pits and road cuts_ give the 

1! miles, in which it ranges from 1,000 to 3,000 following data on the constitution of the roofeet in width and descends from about 90 feet raine in Newington and Portsmouth: 

above sea level to 75 feet. The western slope At the junction ofSherburne and Greenland 

is steep but is in part mantled at its foot by a roads, in Newington, in that part of the roobelt of sand on very gentle slopes. The frontal raine which has a high, broad, flat top, the 10 

scarp is pronounced and 10 to 20 feet high to 15 feet of material immediately next below 

in this reach but vanishes east of Sherburne the summit is gravel, for the most part well' 

Road. The outwash plain is continuous for rounded but containing also many boulders 

4 miles from a point north of Gosling Road that have planed surfaces. The pebbles are 

to a point a quarter of a mile northeast of not assorted as to size, yet there is a distinthe corner of Sherburne and Middle roads. guishable succession of layers dipping about 

It is an almost perfectly smooth surface, having 15° W., and of these the upper layers are more 

a very gentle eastward slope, through which abundantly composed of finer gravel and sand 

there is a gradual transition from gravel and and the lower of coarser stuff. 

coarse sand to clay. There is no natural In the same part of the moraine, at the juneboundary between this clay and the outwash, tion of Gosling Ro-ad and the Greenland road, 

and there is no other basis for the line on the in Newington, an excavation of 3 to 4 feet in a 

map than the limit of the wet, dead-level area flat sandy plain (1, Pl. IX) contains fine yelof the clay plain. lowish sand with relatively few rounded peb-
U. S. GEOLOGICAL SURVEY 

0 

Moraine 

A Sand·an~ ~r<_J.vel j ~tw:-sh Marine clqy i . Marireclay 8 

SECTION ALONG LINE A-B 

PROFESSIONAL PAPER 108 PLATE IX 

L!;(;;:ND 

Moraine 

~ 

~ 

WMl:Mil\Wi~\~j Sand. and ~avel 

§ 

Outwash sand 

and gravel· 

Marine 

~ day 

D 

Rock and till 

0 

Kettles 

Gravel 

~ pit 

[ill 

Glacial striae 

Base and ~e.Olo~ by Frank J.Katz. 

SECTION ALONG LINE C-D 

MAP OF PARTS OF NEWINGTON, GREENLAND, AND PORTSMOUTH, N. H., AND DIAGRAMMATIC SECTIONS SHOWING 

RELATION OF THE NEWINGTON MORAINE TO ROCK AND TILL AND PLEISTOCENE MARINE SEDIMENTS. 
U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE X 

.A. COARSE, PARTLY ROUNDED MATERIAL WITH RUDE STRATIFICATION. 

B. COARSE MATERIAL, FAIRLY WELL ROUNDED, WITH NO SORTING OR 

STRATIFICATION. 

MORAINE GRAVEL ON NEW ROAD, PORTSMOUTH, N. H. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XI 

WIGGINS GRAVEL PIT, PORTSMOUTH, N. H. 

Shows undulating beds of clean, evenly stratified sand abutting against coarse, unsorted, and unstratified gravel. 
NEWINGT'ON MORAINE) MAINE) NEW HAMPSHIR.E, AND MASSACHUSETTS. 19 

bles or boulders and some rock fragments. 

No stratification is shown. 

On the Sherburne road in Portsmouth, half 

a mile east of the excavation last noted, there 

are a pit (2, Pl. IX) and a road cut whi9h show 

approximately 15 feet, measured down from 

the moraine surface, of large cobbles mixed 

with small pebbles and sand, which are like the 

material in excavation 1, but without apparent 

stratification. One-eighth mile to-the south is 

a sand pit (3, Pl. IX), west of the Sherburne 

road, in the place where the moraine ridge is 

low and not distinct from the outwash plain. 

Here, the flat sandy top of the ridge shows 3 

feet of yellow sand containing much dust and 

fine claylike rock flour, scattered pebbles 2 

inches or less in diameter, and a few cobbles 

as large as 6 inches. This material is devoid of 

strati:(ication and hence is not outwash but 

morainic dump. 

In the cut on New Road (4, Pl. IX; see also 

Pl. X), at the west edge of the flat-topped 

moraine crest, there are exposed 10 to 12 feet 

of boulders and coarse gravel packed in fine 

gravel and sand, without clay or other cementing material. The material here, as in 

all but one other exposure, that near Little 

Bay, is dominantly of foreign origin, being 

composed chiefly of granite gneiss, pegmatites, 

basaltic porphyries, and much fine-grained micaceous graywacke gneiss, such as are not 

indigenous to the coastal towns of New Hampshire. Although there are many faceted boulders and pebbles, the dominant forms are 

round and subrounded, and none of them are 

striated. All the materials are surficially more 

or·less iron-stained, giving to the bank as a 

whole a light rusty-brown color, and many of 

the pebbles and boulders are rotted. A small 

part of the west end of this exposure (Pl. X, A ), 

through a thickness of 3 to 4 feet at the top, 

shows a faint trace of stratification parallel to 

the back slope of the moraine ("backset" 

beds). 

In the Wiggins gravel pit, near Middle and 

Sherburne roads, in Portsmouth (5, Pl. IX; see 

also Pl. XI), there are undulating beds of interstratified clean sands and fine gravels which 

abut directly against unsorted coarse rusty 

gravels lightly packed with sandy material but 

not cemented. Weathering has produced a 

black rust varnish on pebbles and boulders 

and has rotted the gabbroid rocks. 

The city gravel pit on Middle Road, Portsmouth (6, Pl. IX; see also Pl. XII, A, p. 24) 

shows stratified material consisting of gravel 

and sand beds and intercalated clay seams that, 

have a southerly dip and are therefore "backset" beds. The gravel consists of pebbles, for 

the most part well rounded and under 6 inches. 

in size, but the number of larger and only 

partly rounded and faceted cobbles is consid-· 

erable, and they show prominently because of 

a lack of pebbles of intermediate sizes. The 

sand and gravel are loose and friable, but the. · 

clayey seams are stiff and project from the, 

face of the bank. 

- On Peverly Hill Road low gravel banks (T 

and 8, Pl. IX) show loose gravels and sands. 

mostly unsorted and unstratified. A small 

cut on the north side of the road exposed in 

1914 a vertical section of 8 to 10 feet of well-· 

stratified small gravel, sand, and sandy clay, . 

dipping 30° W. and about parallel to the surface of the moraine; the upper 3 to 4 feet was 

gravel and the lower part sand. A lens of 

finely laminated clayey sand lay between 

gravel beds near the top of the section, and 

these beds were in · abrupt discordant contact 

with unsorted gravels that were a:U strongly 

iron-stained to the full depth of the exposure. 

Many of the pebbles had the form of faceted 

blocks whose edges and planes had he~en somewhat rounded. Immediately above this pit, 

in the flat summit of the moraine, where it 

lies against Peverly Hill, is another pit (10, 

Pl. IX) 8 to 10 feet deep, which shows evenly 

stratified, approximately horizontal sand and 

fine gravel lying on rounded glaciated ledges. 

A short distance southwest of Peverly Hill, 

near the inner edge of the moraine, there is a 

shallow cut (12, Pl. IX), showing small 

rounded gravel and sand, stratified and dipping southwest, resting against glaciated 

ledges. The city gravel pit on Lafayette 

Road (the Boston post road) near Sagamore 

Creek (11, Pl. IX) contains about 20 feet of' 

stratified gravels and sand. 

The continuation of the moraine southward 

from the pttrt shown in Plate IX has not been 

closely studied. ~ It is, however, known south 

of Berrys Brook in Portsmouth and Rye. In 

Rye Center the moraine is a prominent boulder· 

and gravel ridge, which is narrow and has. 

steep sides, but it broadens and rises to the 

southwest, where it abuts against a rock butte 
20 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

east of West Rye. Thence the gravel ridge 

runs westward to Breakfast Hill, which is 

essentially a rock ledge but is partly mantled 

by the morainic materials. These materials 

are exposed in cuts along Lafay·ette Road, 

where they consist of stratified waterworn 

grav,el and sand having a southerly dip. The 

moraine continues in a southerly direction 

from Brea~fast Hil,.l as a sandy grav,el ridge 

with broad plainlike top extending to Hampton village. 

RYE, NORTH HAMPTON, AND HAMPTON 

SEGMENT. 

The portion of the moraine lying in Rye, 

North Hampton, and Hampton forms a fiattopped ridge running westward from Rye 

almost to Greenland depot and then0e southward through North Hampton and Hampton, 

where it slopes southward , and passes under 

Hampton Marsh. The morainal deposits of 

Greenland, described below, may be an outlying part of this segment. North and west 

of this segment lie low valleys along the heads 

of Berrys Brook and Taylor River, and the 

moraine stands above them with a welldefined scarp. These bounding valleys are 

floored in the main with rock covered with a 

thin coating of till and marine clay. Surfaces 

of this character practically surround the 

outlier near by in Greenland. Th,e morainal 

ridge slopes gent~y eastward and merges very 

irregularly into the low till slopes with numerous rock ledges that extend to the sea. 

Most of the ridg,e is more than 100 feet above 

the s,ea, as is also the Greenland section. The 

two highest points are a mile north of North 

H_ampton village and in Hampton village. In 

<>utward form the morainal deposits of these 

towns are nearly everywhere outwash plains, 

made up of two distinct benches or terraces, 

from 15 to 20 feet apart, both of which are 

well seen in North Hampton and Hampton. 

In most places these terraces or plains have 

little visible slope, but locally they have a 

decided dip. This dip is best seen about a mile 

south of North Hampton village and a~o in 

the ,southerly part of Hampton village, where 

the plain slopes southward under the marsh. 

The westward scarp is usual).y to be seen and 

marks we]J. the old position of the ice front. 

Along or near this are numerous kettle holes, a 

fine group of them appearing haY a mile north 

of North Hampton village. The contrast 

between the fiat-topped moraine and the valleys at the west is best seen in the vUlage of 

North Hampton, where the moraine forms a 

westward-facing scarp of nearly 40 feet. 

Hummocky moraines, till ridges, or kames 

have not been found in this segment of the 

moraine. In the western corner of Rye, where 

the moraine turns southward, a rock hill 

projects 20 or 30 feet above the plain level and 

appears to have formed an anchor for ,the ioo. 

Numerous other ledges project through the 

moraine, rising as high as any of its parts, a~ · 

fo~ instance in Hampton village. _ !:-

The two terraces or benches mentioned above 

are formed by layers of hard gravel between tlie 

sandy portionS" of the morainal deposit. .Atthough there are numerous minor exposures of 

these beds, there are no complete sections. A 

small pit at the west end of North Hampton 

shows about 20 feet of gravelly sand with 

waterworn pebbles. Usually the surfaces of 

the plains or terraces are sandy with scattered 

small pebbles, and as a rule even a small cutting 

below these surfaces exposes gravel. In general the amount of gravel appears to be somewhat greater in Hampton than it is farther 

south or east. The sections observed showed 

sorting and rough bedding of ~he materials. 

MORAINAL DEPOSITS IN GREENLAND. 

In Greenland, N. H., there are two areas of 

morainal deposits that extend south from the 

center of Greenland village along a course 

marked by the highway to North Hampton 

village. They are about 2 miles west of the 

Newington moraine in Portsmouth and, taken 

together, are in a general way parallel to it, 

but they also trend toward the broad area of 

morainal deposits in North Hampton, as if 

they formed a protrusion from that area. The 

deposit in Greenland village forms· a broad, 

flat-topped ridge that descends to a narrow sag 

about half a mile south of the village which 

separates the northern from the southern part. 

The moraine rises southward rather steeply 

from this sag to a narrow, fiat-topped ridge 

about 125 feet above sea level and 1 ~ miles 

long in a south-southwest direction. The west 

side of the moraine is a short and steep slope 

toward the low clay plain of Winnicut River, 

but the opposite side is a broad and gentle 

sandy wash slope which merges into the clay 

plains on the east. 
NEWINGTON MORAINE, MAINE, NEW HAM~SHIRE, AND MASSACHUSETTS. 21 

Upham 1 describes the morainal deposits in 

Greenland as a u kame." He says: 

The academy in Greenland is built on a broadly rounded, 

kamelike ridge of gravel, which at a short distance to the 

southwest becomes a nearly level plain 40 or 50 rods wide 

[Greenland Parade] but still farther to the southwest is 

narrowed to a typical kame. The length of this deposit is 

a half mile. Its height is nearly 100 feet above the sea. 

At a schoolhouse half a mile south from the academy 

we rise to a plain about 125 feet above the sea, which extends a mile to the south and southeast, descending with 

a gentle slope 25 to 40 feet in that distance. This plain 

forms the highest land between Winnicut River and 

Berrys Brook. Its northwest portion is quite thickly 

strewn with boulders, the largest of which are 5 or 6 feet 

in diameter, and over nearly its whole extent these have 

been sufficiently abundant for walling the fields. Four 

wells, however, between the schoolhouse and the Eastern 

depot [Greenland depot, on the Eastern division of the 

Boston & Maine Railroad], varying from 20 to 30 feet in 

depth, passed all the way through stratified gravel, sand, 

and blue clay. In three of these wells the upper portion 

was fine gravel or sand. One of them, a half mile south-

-east, and a cistern a quarter of a mile south from the 

.schoolhouse, showed at the top 10 feet of very coarse but 

waterworn gravel, which was underlain by clear sand. 

The moraine in Greenland marks a halt of 

the ice at a short distance back from the small 

1obe of the Newington moraine in Rye and is 

.seemingly very little younger. 

HAMPTON FALLS, SEABROOK, AND SALISBURY 

SEGMENT. 

Morainal deposits of the next segment con-

·sist almost wholly of outwash sand and gravel 

plains except in Hampton Falls, where a small 

ridge of till is exposed. This ridge starts in the 

center of the village and runs southwest for 

nearly a mile. Along its western border the 

:sand plains of this segment pass very irregularly between a group of till-covered rock hills 

and drumlins in the town of Salisbury, Mass. 

In Seabrook, N. H., the moraine is bordered on 

the wes.t by the low valley of Hampton Falls 

River, which is underlain mainly by till with 

scattered rock ledges. Eastward the sandplain surfaces pass beneath the marshes of 

·Salisbury and Hampton, except for a small 

area in South Seabrook, where till with scattered rock ledges rises a little above the general 

surface of the sand plain. 

The sand-plain characteristics are very well 

marked, especially between Salisbury and East 

1 Upham, Warren, op. cit., pp. 162-163. 

Salisbury, and there are also wide stretches of 

well-developed plain in Seabrook. Although 

these plains are in general nearly horizontal, 

there are locally strong dips-for instance, 1 

mile southwest of South Seabrook, where 

there is a marked dip to the southeast. In 

Salisbury and East Salisbury there is a gentle 

though not obvious dip which results in the 

disappearance of the plain below the level of 

the salt marshes. Rock outcrops are comparatively common in these lower portions of the 

sand plains, but there seems to be no causal 

relation between the position of the rock surface and the plain. 

The deposits of .the sand and gravel plains 

of this segment lie in three benches or terraces, 

at the edges of which hard beds . of gravel 

appear. Two of these benches are seen in 

most of Seabrook and in the northern part of 

Salisbury. The third bench is seen only in 

northern Salisbury about a mile west and 

southwest of South Seabrook. The lower two 

benches are about 20 feet apart; the upper two 

are about 15 feet apart and are separated by a 

heavy bed of fine white sand that is well exposed 

the water tower a mile southwest of South 

Seabrook. The gravel is usually fine and 

makes a smaller proportion of the morainal 

deposits than the gravels of the Rye and 

Hampton segment. The gravels appear to 

rest upon marine clay along the edge of the 

marsh at East Salisbury and also along the 

small brook about a mile northwest of East 

Salisbury. 

NEWBURYPORT SEGMENT. 

The next segment of the moraine runs southeastward from Amesbury through Newburyport to Parker River in Newbury. :Most of 

this segment is separated from the Salisbury 

segment by Merrimack River and the adjacent 

marshes. During the formation of this part of 

the moraine, however, the sand outwash plains 

probably extended northeastward into those 

of the south end of the S~lisbury segment. 

The 1noraine in this segment in general takes 

the form of a distinct ridge bordered by gently 

sloping sand plains on the northeast. TheN ewburyport ridge is for most of its length flanked 

on the southwest by a low valley containing 

numerous rock outcrops or rocky hummocks 
22 SHORTER CONTRIBUTIONS. TO GENERAL GEOLOGY, 1917. 

thinly covered with till. In its northwestern 

part, however, the moraine abuts against a 

high rocky ridge through which the Merrimack 

has cut its course, thus separating about a 

mile of the moraine from the main part in 

Newburyport. 

This segment of the moraine varies much in 

height. At its northwest end it forms a group 

of kames about 150 feet above the sea. These 

diminish in height within a short distance and 

pass southward and southeastward into a welldeveloped sand plain (''Grasshopper Plains'') 

about 100 feet above sea level, which fills in 

the area between the Tock ridge above mentioned and the morainic ridge. 

"Grasshopper Plains" has a broad, nearly 

level surface of more than 1 square mile, which 

is markedly pitted near High Street in Newburyport by kettle holes ranging from a few 

yards to 200 and 300 yards across and reaching 

40 or 50 feet in depth. The smaller kettle 

holes are round and regular in shape but some 

of the largest are less regular and have hummocky and ridged bottoms. From ''Grasshopper Plains" southwestward through Newburyport the moraine is a narrow ridge with a 

definite southwestward-facing ice-contact searp 

30 to 50 feet in height. Part of this searp, between 1 mile and 1-! miles west of the railroad, 

is eomparatively steep and is notably ribbed, 

with deep and sharp reentrants toward the 

north and northeast between the ribs, resembling the buttressed forms on the iee-eontaet 

side of parts of the moraine in Newington. 

Elsewhere this slope, although smoother and 

less steep, is well marked for a distanee of over 

4 miles, to the point where the ice front turned 

southwestward around the drumlins in the 

village of Newbury. In that distance its 

summit diminishes gradually in altitude from 

80 feet above sea level at the northwest to 20 

feet at the southeast. The erest of the moraine 

lies along and for the most part so.uth of High 

Street in Newburyport. It is in general a 

smoothly shaped ridge deereasing gradually in 

height toward the southeast, but in it there are 

several large kettle holes. On the northeast 

side the morainic ridge is bordered by an outwash plain of sand which slopes eastward (in 

part northeastward to the tidal basin of Merrimaek River). Through a distanee of 2 miles 

between "Grasshopper Plains" and the freight 

railroad the moraine stands above the outwash 

plain and is set off from it by an abrupt frontal 

searp, which in plaees is 15 to 20 feet in height 

and is slightly sinuous or sealloped in trend 

where best develop.ed. To the northwest and 

the southeast there is less and in many plaees 

no topographic. distinction between the moraine crest and the outwash. In the form of 

its slopes and in its relation to low meadows on 

the one side and higher, gently sloping sand 

plains on the other side, the Newburyport ridge 

presents features almost identical with those . · 

of Merriland Ridge and the moraine in Biddeford. The moraine in Newburyport extends, 

diminishing in width and height, to the drumlins in Newbury and appears also on the'southeast side of these drumlins as a narrow gravel 

terrace from 10 to 20 feet above sea level. 

The moraine is composed entirely of sand 

and gravel in this segment. The materials are 

not now well exposed at any point, but a th.ickness of about 40 feet is shown in the railroad 

cuts in the city of Newburyport. Upham re .. 

ports that wells in Newburyport show a maximum depth of 90 feet of sand and gravel. The 

materials are waterworn and appear fro~ the 

poor exposures to be stratified, with gentle 

northeasterly dips. A gravel pit just northeast of the drumlins of Newbury shows about 

20 feet of sand and gravel in whieh the pebbles 

are as much as 6 inehes in diameter. The beds 

are roughly stratified and approximately horizontal, and they rest directly on large ledges of 

bedrock. No bedroek projects through the moraine exeept at the border of the high sand 

plain in the western part of Newburyport and 

also at the turn of the moraine next to the 

drumlins in Newbury. At these two loealities . 

the bedrock hills seem to have ehecked the advance of the iee. 

OBSERVATIONS BY UPHAM. 

Upham 1 made the following observations on 

the features herein deseribed as the Newington 

moraine and on associated deposits in New 

Hampshire. It must be remembered in reading these extracts that the term "kame" as 

used by Upham in 1878 eonnoted deposits that. 

were supposed to have been laid down by 

streams flowing between retaining walls of glaeial ice-that is, in erevasses or between ice 

1 Op. cit., pp. 150, 155-156, 164, and 17Q-172. 
NEWINGTON MORAINE, MAINE, NEW HAMPSHIRE, AND MASSACHUSETTS. 23 

lobes-or between an ice wall and a valley 

wall from which the ice had withdrawn. 

In Newington and Portsmouth a kamelike plain of gravel 

and sand is the highest land between Great Bay and the 

Piscataqua River, but their shores, with the islands of 

this river below Portsmouth, are almost everywhere gently 

sloping hills of till or ledge. 

Marine shells and other organic remains have been 

found in the lower portions of this valley [Piscataqua 

basin], showing that the ocean stood at a higher level 

when the modified drift in which they occur was 

deposited. * * * 

Kames and kamelike plains about Dover and southward.-

Near the coast from Dover to Newburyport are frequently 

found massive kamelike deposits, consisting of high plains 

or broadly rounded ridges of gravel and sand, which often 

form watersheds between wide valleys 100 to 200 feet 

below. The absence in these valleys of the terraces which 

mark erosion through modified drift shows that they were 

never filled with the same materials and that these remarkable plains and ridges were deposited in their present 

isolated position, with wide areas of lower land at each 

side. How this took place we can only explain by referring the formation of these deposits to the same causes 

which produced the kames. The ice sheet still remained 

unmelted upon each side at the time of their deposition, filling the valleys and wide areas of lowland, over 

which thls gravel and sand must otherwise have been 

spread by the current of the floods on which they were 

brought. 

The most extensive of these plains occur * * * in 

Newington and the northwest part of Portsmouth. Broadly rounded deposits of the same class occur frequently in 

this district, and southward, along the seacoast, they form 

the elevations on which the villages of Rye, N mth Hampton, and Hampton are built. A very interesting ridge of 

this kind extends from northwest to southeast through 

Newburyport. * * * 

The last of these kamelike deposits which remains to be 

described within the limits of Piscataqua basin is the extensive plain of Newington and the northwest part of 

Portsmouth. This is 3 miles long from north to south, and 

for most of this distance averages a mile in width, forming 

a plateau 60 to 100 feet above Great Bay and Piscataqua 

River on each side. Outcropping ledges and scattered 

boulders are seen in many places upon its surface, but 

numerous wells show only modified drift to depths of 30 

or 40 feet, being first coarse gravel, 3 to 10 feet in thickness, 

succeeded below by interstratified fine gravel and sand. 

The entire western edge of this deposit is a gently sloping 

escarpment, which descends 10 to 30 feet. On the north 

and east it rests mainly on ledges but at one place falls 

in an abrupt slope more than 50 feet. A section at its 

base in the north part of Newington showed sand overlain 

by gray clay, as at Dover. Southward, near the Concord 

& Portsmouth Railroad, its surface is sand, obliquely stratified. Between this and the Eastern Railroad it is changed 

to a broad ridge, 25 to 30 feet high, composed mostly of 

pebbles 6 inches to a foot in diameter, packed as compactly as possible, with no layers of sand. This gravel 

is finely exposed in an excavation, from which it is teamed 

2 miles for repairing streets in Portsmouth. The deposit 

terminates southeast from the Eastern Railroad in a small 

plain of horizontally stratified sand. * * * 

Modified drift along the seacoast.-The oldest and most 

prominent deposits of modified drift near our coast are 

kamelike hills, elevated plains, and broad ridges, composed of gravel, sand, and clay. * * 7<- The gently sloping hill on which Rye village is situated, nearly 100 feet 

above the sea, is mainly stratified gravel from 25 to 40 feet 

in depth. It is coarse for the first 10 feet, with the largest 

pebbles a foot in diameter; below, it is fine but has little 

clear sand. The character of these deposits will be seen 

from the foll~wing sections of wells, 1 to 1!- miles southwest 

from Rye village, on the watershed south of Berrys 

Brook, and about 100 feet above the sea: 

1. AtJ. Philbrick's(countymap)[on the northwest side 

of Washington Road, 1.05 mile west of Rye Center], said to 

be the deepest well in Rye, coarse gravel, 25 feet; sandy, 

gray clay, very compact, free £rom pebbles, 28 feet; total 

depth, 53 feet. The only rock found in the clay was an 

angular block weighing about 200 pounds, 40 feet below 

the surface. 

2. Near L. Brown's [on the northwest side of Washington 

Road, 1.1.5 miles west of Rye Center], coarse gravel, 8 feet; 

sand, 8 inches; coarse gravel, 6 feet; very coarse gravel, 10 

feet, much of it composed of rounded rocks of nearly uniform size, about a foot in diameter, with scarcely any earth, 

so that "one could look down among the pebbles;" ordinary gravel, with layers of sand, 20 feet, resting on ledge; 

total depth, 45 feet. 

3. At R. Shapley's [about 1.4 miles S. 65° W. of Rye 

Center], coarse gravel, 10 feet; fine white sand, 15 feet, 

resting on till or ledge. 

Several other wells in this neighborhood, 30 to 40 feet in 

depth, encountered nothing but stratified gravel, sand, or 

clay. 

Breakfast Hill, about 150 feet above the sea, and the 

plain about 50 feet lower, which extends southward to the 

first railroad crossing in North Hampton, are composed of 

coarse gravel and sand. Thence similar deposits, 100 to 

125 feet above the sea, extend in nearly level plains southwest to North Hampton village, forming the watershed 

between Winnicut River and the ocean. They are 

bounded in many places by escarpments which descend 

steeply 25 to 50 feet, and a hollow, about an acre in extent 

and 50 feet deep, is half fi.lled by Knowles Pond. This 

formation continues southward with nearly the same 

height to Hampton village, where it terminates, falling 

in gentle slopes toward the sea. 

Nine miles farther south part of the city of Newburyport 

is built on a broadly rounded ridge of gravel and sand, 

which, like the foregoing deposits, probably had a similar 

origin with the narrow and steep ridges of the kames, having been bounded by portions of the melting ice sheet. 

The series of kames' noticed by Rev. Mr. Wright in New.:. 

ton and Amesbury may be continuous southeast to the 

Newburyport ridge. So far as traced, this deposit appears 

first in the south part of Amesbury. It has been cut 

through by Merrimack River and on its opposite side rises 

to a height of about 150 fest in Moultons Hill. A quarter 

of a mile farther to the southeast it is depressed to 75 feet 

and shows the sharp ridges and knolls of typical kames. 

From this point it extends, with a nearly uniform height 

of about 100 feet, along High Street to the middle of the 
24 SHORTER CONTR.IBUTIONS TO GENERAL GEOLOGY, 1917. 

city and thence continues on the southwest side of this 

street to the Upper Green. Here it is interrupted for a 

little distance, beyond which it lies on the northeast side of 

this street, extending to within a half mile of Old Town 

Hill. It is thus at least 6 miles long. No other high 

deposits of modified drift are found in this vicinity, and 

wide areas of lowland lie on both sides. Excavations in 

the north.vest part of the city show the ridge there to be 

composed mainly of waterworn gravel, with the largest 

pebbles about a foot in diameter. A railroad cut, known 

as Marchs Hill, 2 miles farther southeast, has only occasional layers of gravel, '\\ith the largest pebbles 6 inches in 

diameter, very irregularly stratified with sand, which is 

here four-fifths of the whole deposit. The depth of 

modified drift forming the ridge is shown by wells to be 

from 50 to 90 feet. 

OBSERVATIONS BY SEARS. 

Sears noted the ridge in Newbury and Newburyport and some sections in it that are not 

now exposed. He regarded it as partly 

moraine and partly barrier beach. The following quotation 1 shows that his interpretation of the position of the ice front with respect 

to the moraine differs from that of the present 

authors: 

The Merrimack River was probablyahalting place of the 

glacial ice in its retreat northward, for its southern shore, 

from the mouth of the Parker River to Pipestave Hill, 

marks typical ice contacts of morainal till and overwash 

gravels capped by sand and silt. High Street, in Newbury and Newburyport, is laid out upon the top of the 

terrace formed by this ice contact, a section of which 

shows it to be composed of boulder till and clay beds resting 

upon the glacial bedrock * * * in varying depths. 

At Grasshopper Plain it is at least 50 feet in thickness and 

is covered by 20 feet of coarse gravel with 25 feet of fine 

sand at the surface. * * * A section of this terrace 

across High Street extending from the rivet through Green 

Street to the frog pond by "the Mall" gives boulder till on 

High Street at an elevation of 80 feet above tidewater. 

The frog pond is the site of a small detached iceberg that 

was buried in the morainal till. South of "the Mall" the 

overwash and outwash gravels have formed a series of cones 

and short ridges or kames of sand and gravel extending 

southeasterly into Newbury. The tracks of the Boston & 

Maine Railroad cut through these gravels on the west, and 

the track of the City Freight Railroad cuts through them 

on the east. In 1898 this cut exhibited a good section of 

the deposits some 300 yards in length. The gravels and 

sands dipped to the south at an angle of 35° and were 

capped by a deposit of clay having sand partings every few 

inches. The greatest depth of the gravel and sand was 40 

feet. North of the center of the hill there was a dip 20 feet 

deep filled with clay having fine sand partings, and under 

the clay, at the bottom of the dip, there was a mass of peat, 

probably the site of an iceberg in the gravel before the clay 

was deposited: 

1 Sears, J. H., The physical geography, geology, mineralogy, and 

paleontology of Essex County, Mass., pp. 296, 301, and fig.169, p. 352, 

Salem, Essex Institute, 1905. 

South of Oak Hill Cemetery there is a "kettle hole.'' * * * It is a typical small ice-block hole with southeastern outwash sand and gravel kames, probably deposited in cracks or gorges in the glacial ice which filled the 

whole valley of Little River. 

High Street, in Newbury, is built on sand and gravel that 

cap clay and till, a typical beach barrier sloping back to 

the lagoon at Four Rock Creek. The debris is washed 

away from the outcropping ledges that rise above the 

boulder till covering the surface. This beach barrier with 

the lagoon on the shore side occupied the whole of the 

Little River valley and was continuous on the southwest 

around ·Old Town and Little Old Town hills. A gorge 

between these hills, now filled with coarse waterworn 

gravels on top of boulder till, was the drainage outlet to the 

southeast. In front of the gravels the outwash sands 

spread out over Newbury Old Town, to the mouth of 

Parker River, where steep banks and fringing lobes extend 

into the salt marsh overlapping the boulder till. 

OTHER ICE-FRONT DEPOSITS OF THE REGION. 

In this region there are a few other ice-front 

or morainic deposits which do not seem to be 

related to the Newington moraine and yet are 

of interest in connection with the subject of 

this paper by reason of their bearing on the 

interpretation of the glacial history of the 

region. The most distant of these is the 

moraine which lies across the south end of 

Lower Bay, Sebago Lake, Maine, 18 miles north 

of the Saco segment. This is a gravel ridge 

trending southwest to west-southwest, rising 

steeply 50 to 60 feet from the lake level, and 

presenting a very gentle southward slope of 

gravel and sand in which there are several 

deep pits occupied by ponds. At the lake the 

outwash slope has an altitude ·of 300 feet above 

the sea and is composed of coarse sand and 

gravel. About 1 ~ miles southwest, at an 

altitude of 200 feet, the outwash is very fine 

sand which grades imperceptibly into marine 

clay. 

The moraine at Bauneg Beg Pond, 3 ~ miles 

north of North Berwick village (Pl. IV, p. 12), 

in the towns of North Berwick and Sanford, 

Maine, is several miles west of Merriland Ridge. 

It surrounds the south end of Bauneg Beg 

Pond as a hummocky, "knob and kettle" 

surface which grades eastward and southward 

into the broad sand plain that over\ies marine 

clay in Wells and North Berwick. 

The moraines at Bauneg Beg Pond and Sebago 

Lake lie several miles back from the Newington 

moraine, at the western edge of the coastal 

lowland.- Besides these moraines and their 

outwash deposits, there are extensive sand 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XII 

A. GRAVEL PIT ON MIDDLE ROAD, PORTSMOUTH, N. H. 

Shows stratified gravel, sands, and clay in the inner side of the moraine, contai ning here 

and there larger but little-rounded cobbles. 

B. GRAVELS AND SAND, PERHAPS OF KAME ORIGIN, IN SUNSET HILL, ELIOT, 

MAINE. 

Poorly sorted, unevenly stratified gravel. 

NEWINGTON MORAINE, MAINE, NEW HAMPSHIRE, AND MASSACHUSETTS. 25 

plains that front the highlands and valley 

trains .in the valleys that debouch from the 

highlands upon the coastal lowlands, as, for 

example, in the valleys of Salmon Falls, 

Mousam, Little Ossipee, and Saco rivers, 

which seem to indicate other moraines or at 

least ice-front positions correlative with the 

moraine at Sebago Lake. The outwash from 

these later ice halts is larger in amount and 

more broadly and deeply 'spf-ead over the 

region. In places the later outwash covers the 

Newington deposits and extends beyond them 

to the present shore line. 

In Eliot and Kittery, Maine, there are anumber of hills (indicated by moraine symbol 

on Pl. IV), wholly or in part composed of 

stratified drift, which lie a short distance east 

(outside) of the Newington moraine. The 

stratified gravels and sands of these hills are 

seemingly kame or other ice-front deposits 

which show no relation to one another nor to 

the Newington moraine. Th~y do not appear 

to mark any definite or continued stand of the 

ice front. The following have been noted, 

and there are doubtless others in the region. 

In Kittery there is a broad, flat-topped ridge 

of gravels and sand in which the Boston & 

Maine Railroad Co.'s gTavel pit exposes a 

thiclmess of about 40 feet of well-sorted and 

stratified materials. An area of stratified 

sands and gravels lies immediately east of Bolt 

Hill, a drumlin, in Eliot. At Greenacre, in 

Eliot, and including Frankfort Island, in 

Piscataqua River, is a narrow patch threequarters of a mile long of low, hummocky 

knolls which are distinctly ka~elike and are 

composed of waterworn gravel and sand. 

Sunset Hill, in Eliot, i~ probably composed 

largely of till but contains in its northern part 

thick deposits of stratified sands and gravel, 

perhaps of kame origin (Pl. XII, B). 

These scattered kamelike or moraine-like 

deposits east of the moraine indicate no prolonged halt in the retreat of the ice before the 

front reached the Newington position. 

NORTHWARD EXTENSION OF THE NEWINGTON 

MORAINE. 

l 

In the town of Saco (see Pl. IV and the map 

of the Portland quadrangle ), from Goose fare 

Brook to Stuart Brook, for 1 i miles along the 

Boston-Portland post road, is a line of ·smooth, 

flat-topped ridges about 100 feet in elevation, 

composed of sand and small gravel which is in 

part water-rounded, sorted, and stratified. 

These ridges rise only a few feet above the surrounding plains of marine clay and sand except 

where rock ledges having the same northeast 

trend protrude through the gravels. These 

ridge's are 4 miles northeast of the Newington 

moraine at Saco River and are separated from it 

by a lowland consisting chiefly of clay. They 

may be an extension or an equivalent of the 

Newington moraine, but the observed facts 

indicate rather that these ridges are to be 

classed with other northeastward-elongated 

hills in the Portland quadrangle, such as part 

of Oak Hill, Pleasant Hill, and Sandy Hill, 

which are drift-covered ledges having superposed mantles of stratified gravels formed by 

the reworking of their till and other drift by 

the sea, which at the same time deposited clay 

in the low places around them. There are no 

other drift deposits farther northeast in the 

Portland quadrangle that can be regarded as 

morainal. If there were such a northeastward 

extension of the moraine it may have been 

destroyed after the Newington substage by 

strong streams that discharged from the Sebago 

Lake or younger ice fronts through the territory 

now largely covered by marine clays in Saco, 

Scarboro, South Portland, and Portland. It 

is more likely that any Il!Oraine deposited in 

this region, where the pre-Newington bedrock 

and till surface is generally low (being now in 

large part below or only slightly above sea level), 

would have been buried by the later marine 

deposits. Morainal material has not been observed where it might be expected on rock surfaces that protrude above the level of the marine 

clay and are in the line of general trend of the 

Newington moraine. It may be inferred, therefore, that the Newington ice front departed from 

this trendeitherseaward by the advance of a lobe 

through the Saco and Scarboro lowland or else 

northward. Southeastward lobation is not attested by any known de.posits of morainic materials. To the north, on the other hand, in the 

northwest corner of the Portland and the northeast corner of the Buxton quadrangles, in Gorham and Buxton, there are gravel ridges and a 

kamelike gravel hill (Pl. IV) which may well 

be parts of the moraine. They are about 2 to 8 

n1iles south of the moraine at Sebago Lake and 
26 SHORTER CONTR.JBUTIONS' TO GENERAL GEOLOGY, 1917. 

approximately on the line between that mo-l Some of the clay lying outside of the moraine 

raine and the Saco segment of the Newington is contemporaneous with and stratigraphically 

moraine, which is 12 miles farther south. On equivalent to the moraine. This relation is 

this line also is the rock ridge north of the Saco best shown at Merriland Ridge, where, in the 

segment, which may be a link between moraine railroad cut (Pl. VII and fig. 1), a bed of clay 

segments like the rock hills between the Bidde- identical with that in the broad plains of rnaford and Kennebunkport segments. The con- rine deposits is intercalated in the sand and 

ditions thus afford a weak suggestion of con- gravel beds of the moraine and outwash. At 

nection between the Newington moraine and that locality also the entire outwash plain 

the moraine at Sebago Lake. The latter, how- slopes down to and grades into a low, swampy 

ever, may belong wholly or in part to a later sand and clay plain about the headwaters of 

substage, -for its gravel and sand outwash in Webhannet River . . It is clear that this clay 

the main is continuous with and in part over- bed records a period of quiet discharge of 

lies the clay and sand plains, which can be glacial waters during which they carried to 

traced without interruption or break in their and deposited on the moraine only the finest 

nearly plane surface to and over the moraine of glacial detritus-rock flour and mud. At 

in Saco. other periods such materials were borne or 

SOUTHWARD EXTENSION OF THE NEWINGTON drifted seaward and deposited in deeper or less 

MORAINE. disturbed waters than those at the ice front, 

The Newington moraine was not traced 

southward and southwestward beyond Newbury. Very probably correlative deposits will 

be found when that region is studied. 

and there formed the plains of which the f:la t 

in the valley of Webhannet River is one. This 

particular plain probably received no appreciable contributions of outwash during stages 

later than the Newington substage, because it 

RELATION OF THE MORAINE TO 

PLEISTOCENE FORMATIONS. 

ROCHES MOUTONNEES AND TILL. 

OTHER is some distance away and cut off by rocky 

uplands from the Kennebunk and Mousam 

valleys on the north and the Great Works and 

All the moraine segments noted lie in part 

on roche moutonnee surfaces and by inference 

also on ground moraine, or till. They have 

not been found to overlie stratified drift or 

such marine sediments as abound in the region. 

Glacially sculptured ledges lie both inside and 

9utside of the moraine-in fact, all the ledges in 

the region have been glaciated. Till also is 

found on both sides of the moraine, and there 

are no perceptible differences between any of 

the exposures of till seen in the region. No 

till has been found in or on the typically developed moraines. 

MARINE SEDIMENTS. 1 

Marine clay and associated sand beds, in 

the main horizontally stratified and in a few 

places fossiliferous, form extensive plains of 

sedimentation throughout the region, both 

east (outside), and also north and west (inside) 

of the moraine. In a few places the clay is 

sandy or contains san~y lenses and beds, and 

over a large part of this region, particularly at 

the north and west, the top beds are clean sand. 

Salmon Falls valleys on the southwest. It was 

from points farther up these valleys that the 

outwash of later stages came. On that account 

the marine clay deposits in the lower parts of 

these valleys are more extensive and at higher 

altitudes than in the coastal territory between 

the drainage basins of these streams. In other 

places the earlier clay deposits and someof the 

sandy outwash of the Newington substage are 

covered by more or less clay discharged into 

the sea from more northerly and later stands of 

the ice, during the time when clay was accumulating behind and upon the inner slope of the 

moraine. In Saco and Biddeford, along Saco 

River, excavations for gravel and sand show 

that the clay overlies the northwest side of the 

moraine and in places covers the crest. In 

most places where the marine clay borders the 

:iri.ner side of the mo;raine the surfaces of the 

two formations meet at an angle, and there is 

no significant mingling of their materials, as 

there is on the opposite side. Wells along the 

western base of the moraine in Portsmouth 

show that the clay does not pass under the 

morain~ but lies against it. The inference to 1 These formations, the so-called "Leda clay" and overlying sands, as be drawn from this fact is that all the deposits developed in southwestern Maine and southeastern New Hampshire, are • • • • 

the subject of another paper, to be published later. I of marme clay and sand lYJ.Ilg mside the New-

,... 
NEWINGTON MORAINE, MAINE, NEW HAMPSHIRE, AND MASSACHUSETTS. 27 

i.."lgton moraine are younger than that moraine. 

Furthermore, these deposits are traceable inland into the broad sand plains and valley 

tra.ins shown on the map (Pl. IV), which are 

evidently glacial outwash from ice that stood 

some miles back of the Newington moraine. 

However, all the clay in this region, from the 

lowest and oldest bed to the highest and 

youngest, must, for the following reasons, be 

regarded as a stratigraphic unit that was deposited uninterruptedly during a period perhaps beginning before the Newington substage 

but certainly continuing through and after it. 

First, the clay can be traced as a continuous 

deposit from points well inside of the moraine 

through such breaks as are made by Sa co, 

Kennebunk, and Salmon Falls rivers in the 

moraine ridge to areas outside of the Inoraine. 

Second, careful scrutiny of the surface forms of 

the clay deposit, 1 of sections in the clay, and of I 

the physical character of the cla;y itself fail to 

reveal any basis for subdivision of the clay 

into younger and older deposits. 

as high as the moraine. Therefore, unless it is 

postulated that an ice block, of which there is 

no evidence, or some high land not now remaining separated the moraine area from the 

ocean, there could have been no body of 

standing water not part of the sea at the required place and altitude to determine the 

form of the moraine. 

3. In Merriland Ridge the interlamination 

of clay with moraine and outwash material, 

and the continuity there indicated of the sand 

and gravel beds in the moraine with marine 

clay beds in the plains to the east show that 

the debris from the glacier was discharged 

directly into the ocean. 

4. Although the wide, level plains of marine 

clay were deposited in situations open to the 

disturbing influence of river, tidal, and storm 

currents, the clay is characteristically uniform 

in composition and texture and in the attitude 

of its bedding. Therefore the clay must have 

been deposited in quiet water-namely, in this 

instance, water whose surface was considerably 

above the levels up to which the clay plains 

EVIDENCE THAT THE MORAINE WAS LAID DOWN were built and in cqnsequence probably deep 

IN THE SEA. enough to submerge the moraine. 

The foregoing observations on the relation POSITION OF 'THE MORAINE WITH RESPECT TO 

of the Newington moraine to marine sedi- DIRECTION OF ICE MOVEMENT. 

ments indicate that the ice front stood in the The general direction of ice movement in 

sea at the time and place of deposition of this this region was south-southeastward, as is indimoraine. This conclusion is established by cated by numerous striae and also by a few 

the following evidence: drumlins. In the neighborhood of Biddeford, 

1. The surface of the moraine, as shown Maine, the striae trend S. 10°-15° E., and 

above, is in most places fairly smooth or is from Biddeford so:uthwestward the easting inhummocky onl~ in a small way by reason of creases with seeming regularity to S. 40o ±so E. 

knolls that are low and have gentle slopes, in in the neighborhood of Portsmouth, although 

contrast to.the characteristically knobby ka~e there are local exceptions. The ice flow was 

forms, and In large part the crest of the moraine in accord with the general southeasterly land 

is broad and fiat. Fur~her~ore, altho~gh the slope and approximately paraUel to the trend 

material of the moraine Is predorrnnantly I of the major drainage lines. The moraine segrounded,. wat~r-tra:r:sported, and accuin:rrlated ments in Biddeford, Kennebunkport, Wells, 

by glacwflu~Ial discharge, the for~ Is not South Berwick, Rye, the Hamptons, Seabrook, 

~h~t of moraines accumul~ted subaenally but and Salisbury are then approximately athwart 

Is hke that of a delta or a hne of rr:-any.laterally the general course of ice movement, and ,such 

confluent d~ltas, as for example In Biddeford, departures of the moraines from that trend as 

Wells, Newington, North Hampton, and Sea- are indicated by the map are accounted for by 

brook. the influence of the local topography of the 

2. These very nearly level and broad, fiat rock floor. 

delta-like tops are all near the sea and are not Dn the other hand, the Dover Neck, Newseparated from it by any present obstructions ington and Portsmouth, and Newburyport segIThewriter'sobservationsoffernosupportforsubdivisionoftheclay ments are in part oblique to and in part even on the basis of "distinct topographic types," as postulated by F. G. nearly parallel to the general direction of ice 

Clapp (Complexity of the glacial period in northeastern New England: 

Geol. soc. America Bull., vol. 18, pp. 505-556, 1907). movement. The explanation of this seeming 
28 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

discordance is found in the fact that the the ice front during the accumulation of the 

moraine is predominantly the product of ac- morame. 

cumulation of the load of effluent glacial 

waters and is not pushed material. It might DISCON'pNUITY OF THE -MORAINE. 

therefore lie at any site on the margin of the The major intervals between the segments 

ice which permitted the discharge of glacial of the Newington moraine which require explastreams, regardless of the normal form of the nation are of two kinds. Those in Biddeford 

front with respect to the direction of ice advance. [ and Kennebunkport and in Wells and South 

The factor that in all probability chiefly deter- Berwick are occupied by rock hills of greater 

mined the form of the ice edge in the vicinities height than the moraine. These rock hills are, 

of Portsmouth and Newburyport was the de- in fact, links rather than gaps between the 

struction of the glacier by calving of bergs and moraine segments. They obstructed the admelting in the deep waters of the Piscataqua vance of the ice and were the anchors that held 

and Merrimack estuaries. Thus ' reentrants the ice and in a measure determined the posiwere made in the ice front. Probably also tion of the Newington halt. No effort was 

subglacial drainage in large volumes was dis- made to find on these hills morainal deposits 

cparged at these low points and assisted in marking the position of the ice front; perhaps 

cutting back the front. careful search will disclose them. However, 

the absence of push ni'aterial and the preponderance of stream-borne materials along other 

parts of the ice border lead to the inference that 

little morainic drift was piled up against or on 

these hills, for they could not have been the 

sites of glaciofluvial discharge. Such materials 

as were dropped here from the melting ice were 

perhaps too small in amount to make a noticeable accumulation and would otherwise be 

indistinguishable from ground _ moraine. 

RECESSIONAL NATURE OF THE MORAINE. 

A large number of exposures of drift deposits 

have been observed in the course of five seasons' field work on the general geology of 

southwestern Maine and the adjacent part of 

New Hampshire, particularly in the regions 

of Portland, Maine, and Portsmouth, N. H., 

which have been closely examined. In none 

of these exposures is there any evidence of 

more than one ice advance over that region. 

There is no superposition of later till on earlier 

till; there are no differences in the degree of 

weathering or extent of. erosion of till which 

could safely be ascribed to any other cause 

than accident of situation or exposure; and 

there are no "interglacial" deposits. There 

is, therefore, no basis for assuming that the 

Newington moraine marks the termination of 

an epochal advance or readvance of the ice, 

nor even of a very short readvance. It can 

only be concluded that this is a recessional 

moraine that marks a stand of the ice front 

conditioned by a balance between the rates of 

ice movement and of ablation. In accord with 

this conclusion is the evident lack of angular 

till and of materials heaped up by glacial shove, 

a fact which suggests that the ice was not moving vigorously. The regular stratification of 

the washed material also indicates that the ice 

On the other hand, the Kennebunk, Mousam, 

and Salmon Falls valleys make real breaks in 

the continuity of the moraine so wide (7 and 

8 miles) as to demand special consideration. 

A brief search in these valleys for morainal 

deposits or for evidence of either absence or 

obliteration of the moraine was without conclusive result. On account of the deep filling 

by later marine sediments there seems to be 

little chance of establishing either the presence 

or the absence of the moraine across these 

valleys, but the manner in which the clay and 

sand plains surround exposed ends of moraine 

segments suggests strongly that the continuations of the segments lie buried under clay 

in the deeper parts of these valleys, just as 

the Biddeford and Saco segments are partly 

buried in the Saco Valley. 

AGE OF THE MORAINE. 

front made no advance during the deposition The age of the Newington moraine can not 

of the moraine. On the contrary, the great be decisively stated until the general problems 

width of parts of the moraine and the thickness l of Pleistocene correlation in ~orthern .New Engof the "backset" beds indicate slow retreat of land have been settled. It Is established that 
NEWINGTON MO,R.AINE, MAINE, NEW HAMPSHIRE, AND MASSACHUSETTS. 29 

the Newington moraine is the youngest strictly 

glacial deposit in the im1nediate vicinity of the 

coast of New Hampshire and southwestern 

Maine. The only younger deposits are the later 

beds of marine clay ("Leda") and sand which 

overlie parts of the Newington moraine, and, as 

has been indicated, these are sea-laid outwash 

materials of a somewhat later stage during 

which the ice front stood not far back from the 

Newington moraine. Clapp's statement 1 that 

there is a till formation younger than and overlying marine ("Leda") clays finds no support 

in any exposed sections of the clay and its 

associated deposits which the authors have 

been able to find. But it is not merely for 

that reason that Clapp's conclusion is held to 

be inapplicable to the coastal region here con-

. sidered. The critical fact is that the surface 

of the clay deposit is not glaciated but is a plain 

of deposition which, except for slight or moderate trenching by stream erosion, has been entirely unaltered since it.s formation. It is not 

denied that Pleistocene marine clays older than 

the Newington substage may have been covered by till, but if such clays are present in 

this region they are not to be seen be·cause they 

are buried. It is also granted that elsewhere 

marine clays equivalent to the Newington or 

later substages may have been glaciated but 

not that such relations have yet been established. 

It seems reasonable and safe to assume that 

when ice of the Wisconsin stage occupied Long 

1 Clapp, F. G., Complexity of the glacial period in northeastern New 

England: Geol. Soc. America Bull., vol. 18, pp. 505-556, 1907. 

Island, Marthas Vineyard, Nantucket, and the 

Cape Cod Peninsula 2 there must have been ice 

over the coastal counties of New Hampshire 

and southwestern Maine. Therefore, it must 

be concluded that the Newington moraine is of 

Wisconsin age, probably late Wisconsin, and, 

as a corollary, that so also is the marine 

("Leda") clay 9f that region. 

SUMMARY. 

A recessional moraine consisting of several separate segments disposed along a sinuous course lies near the Atlantic coast and has been traced through 60 miles from 

Saco, Maine, to Newbury, Mass. It is for the most part 

about or less than 100 feet above sea level but rises to 180 

feet in Biddeford, Maine, 150 feet in Dover, N.H., and 

Newburyport, Mass., and is between 200 and 250 feet above 

the sea in Wells and South Berw~ck, Maine. AI though not 

more than 40 to 100 feet higher than surrounding Pleistocene formations, nevertheless it is topographically prominent because it is in a region of slight relief. The moraine 

rests upon and is surrounded by a floor of ice-smoothed 

rock and of till. The region was submerged during the 

building of the moraine, and the ice front stood in the sea. 

The moraine is the result of the accumulation of glaciofluvial detritus discharged directly .into the sea; consequently in some places it is built up as broad, flat, deltalike plains of sand and gravel. Clay (" Leda clay") was 

continuously deposited in the sea, both while the moraine 

was accumulating and after the ice retreated from the mo-

.raine, so that the younger clay beds in some places overlie 

the moraine. This clay is the fine glacial outwash. The 

moraine and the marine clay probably belong to a late 

Wisconsin substage of the Pleistocene epoch. 

2 The correlations of moraines in these regions with the early Wisconsin 

moraine of New Jersey is accepted. See Fuller, M. L., The geology of 

Long Island, N.Y.: U.S. Geol. Survey Prof. Paper 82, table opposite 

p. 220, 1914. 

0 
COMPARISON OF PALEOZOIC SECT10NS IN SOUTHER.N NEW MEXICO. 

Crania aff. C. missouriensis. 

Schizophoria aff. S. swallowi. 

Productus aff. P. burlingtonensis. 

Productus aff. P. arcuatus. 

Productus aff. P . sampsoni. 

Pustula n. sp. 

Pustula sp. 

Rhynchopora occiden talis. 

Camarotoechiaaff. C. metallica. 

Spirifer aff. S. grimesi. 

Spirifer aff. S. vernonensis. 

Brachythyris aff. B. suborbicularis. 

Delthyris novamexicana. 

Reticularia aff. R. cooperensis. 

Pseudosyrinx aff. P. gigas. 

Athyris lamellosa. 

Cliothyridina temeraria. 

Cliothyridina aff. C. obmaxima. 

Cliothyridina aff. C. incrassata? 

Eumetria? tuta. 

Platyceras aff. P. equilatera. 

Gon:iatites sp. 

Orthoceras? sp. 

Phillipsia aff. P. peroccidens. 

Proetus sp. 

Griffithides? sp. 

The crinoids were not as abundant in bed 8 

as in bed 7. Beds 5 and 6 contain corals and 

crinoids, but nothing was determined. According to Keyes bed 5 is Devonian, 1 consisting of 

three members, the lowest of which carries a 

typical late Devonian fauna. 

In the exposure of Lake Valley limestone, 2 

miles east of Hillsboro, Gordon 2 found beds 5 

and 6 absent and beds 7 and 8lying on fossiliferous Devonian shales. The following fossils 

were obtained : 

Cyathaxonia? sp. 

Zaphrentis sp. 

Amplexus aff. A. fragilis. 

Periechocrinus whitei. 

Rhodocrinus wortheni var. urceolatus. 

Cactocrinus multibrachiatus. 

Leptaena analoga. 

Cactocrinus proboscidialis. 

Steganocrinus pentagonus. 

Platycrinus subspinosa. 

Platycrinus sp. 

Physetocrinus lobatus. 

Physetocrinus copei. 

Fistulipora americana. 

Schizophoria aff. S. swallowi. · 

Rhipidomella dalyana. 

Leptaena analoga. 

Productus aff. P. burlingtonensis. 

Pustula n. sp. 

Spirifer aff. S. vernonensis. 

Spirifer aff. S. grimesi. 

Delthyris novamexicana. 

Brachythyris aff. B. suborbicularis. 

1 Am. Inst. Min. Eng. Trans., vol. 39, p. 147, 1909. 

2 Am. Jour. Sci., 4th ser., vol. 24, p . 61, 1907. 

Sp iriferina sp. 

Athyris lamellosa. 

Cliothyridina aff. C. ~ 

glenparkensis. ,...., ..... ~ Platyceras aff. P. equi- g ~ ~ 

latera. t€ ~ •

1 

Platyceras sp. 

Orthonychia sp. 

Phillipsia aff. P. peroccldens. 

Proetus aff. P. loganensis. 

At Kingston, 9 miles 

west of Hillsboro, the 

following fossils were 

found by Gordon: 3 

§'2.ff 

§<g. 

~ ~ g· ... ~~ ~ 

g ~~ ~CIQ ~ s _ ..... ~ 

§ofi 

:=¢~ 

s 8. 0 ~ it '"d e-t- .... {t) 

g.?'S. 

•• "' r:n s Q:> p 

~ ~~ ... ~s~ qg~ 

::::,-...o 

~~~ 

g ~~[ •. Q:> 

~ !!> ~· ~ t".! (!) ~ D' ,_. ~ NQI 

s. ~ ~ ~ ro- ~.i:); 

Zaphrentis sp. 

Amplexusaff.A.fragilis. 

Platycrinus sp. 

Fenestella sp. 

Rhombopora sp. 

Leptaena analoga. 

Schizophoria aff. 

swallowi. 

Pustula n. sp. :n--

Spirifer aff. S. ~·s·s vernon- ~· ~ ~ 

ensis. :.§a 

Brachythyris aff. 

suborbicularis. 

B ~ ~ ... o 

• ~ J3 ~ 

Pseudosyrinx aff. 

gigas. 

P. ~ f~ a:: ..... ~ 

~ ~ 8' Athyris lamellosa. g.~El 

Cleiothyridina aff. 

incrassata. 

c. §' El t" ~ ~ ~ 

~§b 

From limestone overlying the Percha shale a 

short distance east of 

Kingston the writer collected t h e following 

f o r m s , identified by 

G. H. Girty: 

Fenestella, several sp. 

Polypora sp. 

Rhombopora sp. 

Cheilotrypa? sp. 

Cystodictya aff. C. 

pustulosa. 

In another bed were 

found the following: 

8 a> ,. 

'?~~ e; t::l l>l''Cl 

s t::l 

~ s 

f!l.Q 

al ~ ,_.'"d o< 

§' ~. ~ ~ g r+ 

§ ~ ~~· a> t::l o- o '< 0(.1\ 

< 0 @ 

~ P ro- s· to 

.., ~t€ 

~ 0 D'-

~ 2€ .....~ 

'< ~ 

=§ 

~In' 

~;;; § a> 

~t:: 

Cladochonus sp. ~ ~ CJ:athaxonia arc11ata? :_ ~ &q· ~ 

Fenestella sp. g a> 

Polypora sp. ~ ~ 

Rhombopora sp. ~ S' 

Rhlpidomella? sp. ~ ~ 

Productus aff. P. mesialis. 

Delthyris? sp. 

Spiriferina sp. 

Cliothyridina aff. C. glenparkensis. 

a Idem, p. 62. 

-! 

0 

0 

I 

I 

I ~ Esco~dido 

Canyon I 

I 

I 

51 
52 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

The fossils collected by Lee in the canyon of 

Rio Salado, on the south side of the Sierra 

Ladrones, were determined by G. H. Girty,t 

as follows. All of them are lower Mississippian 

forms: 

Zaphrentis 2 sp. 

Granatocrinus? sp. 

Platycranus? sp. 

Rhipidomella aff. R. dubia. 

Spi.rifer aff. S. logani. . 

Spirifer aff. S. tenuicostatus. 

Spiriferella aff. S. neglecta. 

Athyris lamellosa. 

Cliothyridina aff. C. obmaxima. 

Phillipsia sp. 

There are abundant fossils in the Lake Valley 

limestone in the Cooks Peak region. The following were determined by G. H. Girty: 

Rhombopora sp. 

Cystodictya aff. C. pustulosa. 

Paraparchites sp. 

Leptaena analoga. 

Rhipidomella pulchella? 

Prod uctus semireticulatus. 

Productus ovatus. 

Productus aff. P. burlingtonensis. 

Productus aff. P. wortheni. 

Brachythyris suborblcularis? 

Spirifer centronatus. 

Composita humilis. 

From the lower division of the Fierro limestone of the Silver City region Paige obtained 

the following distinctive Mississippian forms 

identified by G. H. Girty: 

Actinocrinus copei? 

Dorycrinus lineatus. 

Leptaena analoga. 

Rhlpidomella aff. R. oweni. 

Prod uctus mesialis. 

Spirifer aff. S. imbrex. 

Reticularia cooperensis. 

Girty 2 regards the Lake Valley fauna at 

Silver City as closely related to that· found at 

Fern Glen, Mo., and at other points in that 

general region. 

From the _Kelly limestone in the Magdalena 

Range, Keyes 3 reports Batocrinus subaequalis 

Hall. 

From the Mississippian beds in the section 

east of Alamagordo, Girty 3 obtained the following species: 

1 Personal communication. 

2 U.S. Geol. Survey Geol. Atlas, Silver City folio (No. 199.\, p. 5,1916. 

a Am. lnst. Min. Eng. Trans., vol. 39, p. 169, 1909. 

Triplophyllum sp. 

Leptaena analoga. 

Schuchertella aff. 

S. chemungensis. 

Rhipidomella diminutiva? 

Schizophoria postsriatula? 

Productus gallatinensis. 

Productella n. sp. aff. P. pyxidata. 

Shumardella? aff. S. missouriensis. 

Brachythyris suborbicularis. 

Ambocoelia levicula. 

Reticularia cooperensis. 

Proetus peroccidens. 

Spirifer sp. undet. 

Platyceras sp. undet. 

In 1915 the writer collected from shales 

about 50 feet above the Fusselman ledge on the 

north side of Alamo Canyon the following forms 

identified by G. H. Girty: 

Zaphrentis sp. 

Rhipidomella dalyana. 

Schizoporia? sp. · 

Spirifer rowleyi. 

Spirifer centronatus? 

Delthyris novamexicana. 

Composita humilis? 

Cliothyridina pro uti? 

Cliothyridi:Q.a sp. 

At the same horizon in the slope near Dog 

Canyon wete collected the following: 

Schizoblastus aff. S. roemeri. 

Dielasma sp. 

Spirifer aff. S. grimesi. 

Platyceras aff. P. fissurella. 

Platyceras aff. P. paralius. 

Platyceras aff. P. equilatera. 

Lower Mississippian (Lake Valley) ·fossils 

were collected at several localities in the San 

Andres Mountains. The following forms were 

identified by G. H. Girty: 

San Andres Canyon, in heavy ledge above Percha shale: 

Triplophyllum sp. 

Schizopophoria aff. S. swallowi. 

Productus aff. P. arcuatus. 

Spirifer aff. S. grimesi. 

Spi1ifer centronatus. 

Brachythyris suborbicularis. 

In cherty beds at top of this heavy ledge, in a canyon 

3 miles south of San Andres Peak: 

Triplophyllum sp. 

Spirifer aff. S. pellensis. 

Eumetria vera. 

In the basal part of the first heavy ledge above the 

Percha shale on the ridge west of the San Nicolas Spring: 

Cystodectya sp. 

Chonetes aff. C. logani. 

Spirifer sp. 
COMPARISON OF PALEOZOIC SECTIONS IN SOUTHERN NEW MEXICO. 53 

MAGDALENA GROUP. 

The representatives of the Pennsylvanian 

series have been studied in detail in many parts 

of New Mexico, but the following statements 

refer only to the beds associated with the older 

formations in southern New Mexico and adjacent parts of Texas. 

Cooks Range.-About 40 feet of dark-gray · 

shale lying on the white chert of the Lake Valley limestone high on the slopes on the northwest side of Cooks Peak yielded fossils that 

appear to indicate the presence of a representative of the Magdalena group, the lowest subdivision of the Pennsylvanian series in New 

Mexico. Possibly it occurs elsewhere in Cooks 

Range, b~t at all other places visited the Gym 

and Lake Valley limestones are in immediate 

succession. The fossils in the limy layers in 

the shale include the following, all determined 

by G. H. Girty: 

Derbya crassa. 

Chonetes mesolobus. 

Productus semiretlculatus. 

Pustula nebraskensis? 

Marginifera rnuricata. 

Pugnax sp. 

Spirifer cameratus. 

Spirifer rockymontanus. 

Ambocoelia planiconvexa. 

A viculipecten, 2 sp. 

Acanthopecten carbonifer. 

Lima retifera. 

Astartella vera. 

Edmondia subtruncata. 

Phillipsia scltula. 

Silver City region . ..:.._As remarked on page 48, 

the upper part of the Fierro limestone of the 

Silver City region. as defined by Paige in the 

Silver City folio, includes beds representing 

more or less of the Magdalena group. The 

fossils found in this upper division were determined by Girty as follows: 

Fusulina secalica. 

Campophyllum torquium? 

Zaphrentis sp. 

Chaetetes milleporaceus. 

Fenestella tenax. 

Stenopora sp. 

Meekopora? sp. 

Prismopora triangulata. 

Productus cora. 

P. semireticulatus. 

Pustula nebraskensis. 

Spirifer cameratus. 

S. rockymontanus. 

Squa~ularia perplexa. 

Composita subtilita. 

Cliothyridina orbicularis. 

These forms are comprised in the Magdalena 

fauna in Sierra and Socorro counties.· 

Mimbres Mountains.-At Kingston, on the 

east slope of the Mimbres Mountains, according 

to Gordon, 1 the basal Magdalena strata consist 

of about 300 feet of dark-blue and gr'ay limestone in thick beds with thin shale partings. 

The upper part of the group has about the 

same thickness and consists chiefly of blue and 

drab shales interstratified with several beds of 

limestone from 15 to 20 feet thick. Unconformably overlying these beds are -red sandstones and shales (Abo sandstone) of the Manzano group. At the Palomas mining camp, 

20 miles north of Kingston and 2 miles east of 

Hermosa, the Palomas Creek canyon has 

nearly vertical walls, the lower half of limestone and shale in about equal amounts and the 

upper half of hard, massive gray limestone. 

About halfway up the cliff a few thin beds of 

quartzite are interstratified with the other 

rocks. There is no evidence on which to separate the group into Sandia formation and 

Madera limestone, as in the region farther east. 

Magdalena Mountains.-In the Magdalena 

Mountains, according to Gordon, 1 the basal 

member of the Magdalena group is 10 to 15 

feet of moderately coarse conglomerate interstratified with dark shale, whose bedding is 

apparently parallel to that of the underlying 

Kelly lirr1estone. This conglomerate is over-· 

lain by 115 feet of limestone capped by coarse 

white quartzite or conglomerate in massive 

ledges separated by thin beds of shale. Next 

above is a member 80 to 90 feet thick, consisting mostly of limestone, in which are some 

thin beds of shale and quartzite. The basal 

part of this member is 6 feet of thick-bedded 

drab-blue subcrystalline limestone; next above 

are 25 feet of shale and thin limestone, 2 feet 

of quartzite, 50 feet of compact bluish earthy 

limestone, and 410 feet of shale and conglomeratic sandstone or quartzite. The total thickness of these beds (Sandia formation) is about 

600 feet. They are overlain by 300 to 500 feet 

of limestone (Madera), more or less of whose 

surface has been removed by erosion. 

GYM LIMESTONE. 

The Manzano group is represented in central 

and northern New Mexico by the Gym limestone, whioh crops out extensively in the Flor1 U. S. Gaol. Survey Prof. Paper 68, pp. 232, 269, 1910. 
54 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

ida Mountains, type locality/ and also in the 

Victorio Mountains. In both places it lies 

unconformably on formations from the El 

Paso to the Fusselman, for the Percha shale and 

Lake Valley and Magdalena limestones are 

absent. In Cooks Range a thin body of the 

Gym limestone lies on the Lake Valley limestone at most places, but on the northwest 

slope of Cooks Peak these two limestones are I 

separated by an outlier of shale of Magdalena 

age. The Gym limestone also appears extensively in the Tres Hermanas Mountains, where 

it is uplifted and cut by porphyry, and it also 

crops out in a few small hills rising out of the 

desert in the south-central part of the county. 

The formation has not been recognized outside 

of Luna County, although doubtless it is represented in the Manzano and Hueco sections in 

other areas. 

NW. 

0 

Prod uctus semireticula tus. 

Productus occidentalis. 

Prod uctus cora. 

Marginifera splendens? 

Pugnax utah. 

Squamularia perplexa. 

Composita perplexa. 

Composita subtilita. 

Composita mexicana? 

N ucula levatiformis. 

Nucula levatiformis var. obliqua. 

Manzanella elliptica. 

Parallelodon politum? 

Pinna peracuta. 

Monopteria marian? 

Plagioglypta canna? · 

Bellerophon crassus. 

Bellerophon majusculus? 

Bucanopsis modesta. 

Pleurotomaria texana. 

Rhynchomphalus obtusispira. 

Euomphalus aff. E. pernodosus. 

Chonetes playtnotus? 

I MILE 

FIGURE 15.-Section across the southern part of the Florida Mountains, Luna County, N. Mex. gr, Granite; b, Bliss sandstone; e, El Paso 

limestone; mf, Montoya and Fusselman limestones; g, Gym limestone with dark-gray shale member (sh). 

In the Florida Mountains the Gym limestone 

is about 1,000 feet thick, but, as shown in 

figure 15, it is greatly faulted and the u:ppermost beds have been more or less deeply removed by erosion. In Cooks Range its thickness is less than 50 feet. 

The formation consists almost entirely of 

light-gray limestone, mostly massive and in 

part brecciated. An 80-foot member of darkgray shale is ap.parently included on the southeast slope of the Florida Mountains, but this 

may be the Percha shale overlapped, or faulted 

into its present position. In the Tres Hermanas Mountains part of the Gym limestone 

is metamorphosed to white marble and there is 

included a member of 50 to 60 feet of gray to 

reddish quartzite. 

Fossils were collected at several horizons in 

the Gym limestone at numerous localities. 

They were determined as follows by G. H. 

Girty: 

Echinocrinus ornatus. 

Meek ella mexicana? 

I Darton, N. H., Geology and underground water of Luna County, 

~. Mex.: U.S. Geol. Survey Bull. 618, p. 35, 1916. 

Orthonema socorroense? 

Sphaerodoma aff. S. humilis. 

Sphaerodoma aff. S. primigenia. 

Bulimorpha inornata. 

In the San Andres and Sacramento mountains and farther north in New Mexico the supposed equivalent of the Gym limestone is separated from the Magdalena group by a thick 

series of red beds (Abo sandstone), but these 

beds are lacking in the southwest corner of the 

State and also in the region near and east of 

El Paso. 

Most of the fossils in the Gym limestone are 

doubtless of the Manzano group, but they do 

not afford a basis for correlation with the rocks 

of other regions, nor do they indicate how 

much of the group is represented here. Mr. 

Girty has called the writer's attention to the 

fact that Productus occidentalis is characteristic of the limestone capping the Sacramento 

Mountains at Cloudscroft, a bed which is high 

in the Carboniferous. Some of the gastropods 

strongly suggest the Hueco fauna, and therefore the formation is believed to represent part 

of the Hueco limestone. 
COMPAR.ISON OF PALEOZOIC SECTIONS IN SOUTHERN NEW MEXICO. 55 

HUECO LIMESTONE. 

According to Richardson 1 the Carboniferous 

rocks are represented in the Franklin and 

Hueco mountains by a massive gray limestone 

of which 3,000 feet appears, but the total thickness is greater, as more or less of the top has 

been covered or removed by erosion. Thin 

bedding is rare, and chert is practically absent. 

The magnesia. content was found to be less than 

1 per cent. Locally some beds are black; in 

the Hueco Mountains most of the limestone is 

light colored. The Hueco Mountains consist 

mainly of this formation, and it constitutes the 

northwestern flank of the Franklin Mountains. 

The Hueco limestone carries a·n abundant fauna 

regarded by Girty as of late Carboniferous age, 

on account of which at least the upper part of .it 

has been tentatively correlated with the Kaibab 

limestone of northern Arizona. 

GEOLOGIC HISTORY. 

The sequence of events in southern New 

Mexico during the earlier part of the Paleozoic 

era can be known onlyin a most general way, 

for many long intervals of the time are not 

represented by deposits. It is probable that 

many beds were laid down that were subsequently removed. Doubtless some of the beds 

now remaining have been thinned by erosion, 

and possibly, also, they were formerly much 

more extensive. Some or all of the pre-Pennsylvanian formations may have covered all of 

New Mexico. Apparently the uplifts were 

l U.S. Geol. Survey Geol. Atlas, El Paso folio (No. 166), 1909. 

widespread and not attended by folding, for the 

attitude of all the Paleozoic formations is the 

same with a few slight local exceptions. 

The first Paleozoic event of which there is 

evidence was the deposition of sand on beaches 

of granite and other old rocks in the later part 

of Cambrian time. There may have been 

accumulations of ea:rlier Cambrian sediments, 

but if so they were completely removed. Possibly sedimentation was continuous into early 

Ordovician time, when the materials of' the El 

Paso limestone accumulated to a thickness of 

900 feet or more. The hiatus between the El 

Paso limestone and the Montoya is a long one, 

representing all of the Middle Ordovician and 

the early part of the Upper Ordovician. The 

hiatus between the Montoya and Fusselman is 

from late Richmond to probable early Niagara 

time. Only a small part of later Devonian 

time is represented by the Percha shale, so 

during that epoch there was either long emergence of the land or extensive removal of earlier 

Devonian sediments. During part of early 

Carboniferous time the region was submerged 

and the Lake Valley sediments were laid down, 

but there is only a long hiatus to represent later 

Mississippian time. Pennsylvanian and Permian time is represented in the main by deposits 

of the Magdalena and Manzano groups and the 

Hueco and Gym limestones. The Hueco and 

Gym are contemporaneous, at least in part, 

with the Manzano group, which includes 500 

to 1,000 feet of red beds (Abo sandstone) that 

thin out to the south. 

0 

DEPARTMENT OF THE INTERIOR 

FRANKLIN K. LANE, Secretary 

UNITED STATES GEOLOGICAL SURVEY 

GEORGE OTIS SMITH, Director 

Professional Paper 108-C 

A COMPARISON OF PALEOZOIC SECTIONS IN 

SOUTHERN NEW MEXICO 

BY 

N. H. DARTON 

Published May 29, 1917 

Shorter contributions to general geology, 1917 

(Pages 31-55) 

WASHINGTON 

GOVERNMENT PRINTING OFFICE 

1917 

CONTENTS. 

Introduction .................................... . 

Cambrian system .................. . ............ . 

General features ........................... . 

Bliss sandstone .............................. . 

Franklin Mountains ...................... . 

Florida Mountains and Cooks Range~ .... . 

Silver City region .............. · .......... . 

Caballos Mountains ..... . ............... . 

San Andres Mountains .................... . 

Sacramento Mountains ......... .......... . 

Mimbres Mountains ...... . ........... ~ .. 

Ordovician system ............ ·.· ..... . ........... . 

General features ........................... . 

El Paso limestone ........................... . 

Franklin Moi.uitains ...................... . 

Florida Mountains ......... __ . ... . ....... . 

Cooks Range ............................ . 

Snake Hills ...... ~ ...................... . 

Victorio Mountains ....................... . 

Klondike Hills ........................... . 

Silver City region ........................ . 

Caballos Mountains ..................... . 

Lake Valley district ................... _. 

Mimbres Mountains ..... . ................ . 

San Andres Mountains .................. . 

Sacramento Mountains ............... . ... . 

Fossils ............... . . . . . ......... · ..... . 

Age and correlation ....................... . 

Montoya limestone .............•..... . ........ 

General relations ......................... . 

Franklin: Mountains ...................... . 

Luna County ............... . ........ ... . . 

Silver City region ........................ . 

Caballos Mountains and adjoining regions. 

Lake Valley .............................. . 

Mimbres Mountains ..................... . 

San Andres Mountains .... . ...... . ...... . 

Sacramento Mountains ................... . 

Fossils .................................. . 

Age and correlation ........... . .......... . 

Silurian system ................................... . 

Fusselman limestone ........................ . 

Franklin Mountains and eastward ....... . 

Cooks Range ............................ . 

Florida Mountains ..................... . . . 

Page. 

Silurian system-Continued. 

Fusselman limestone-Continued. 

Page. 

31 

32 

32 

32 

32 

32 

32 

33 

33 

,33 

33 

Victorio Mountains ...................... ·.. 41 

Silver City region......................... 41 

Caballos Mountains ...................... · 41 

Robledo Mountain .. -................... 42 

Lake Valley..... . . . . . . . . . . . . . . . . . . . . . . . . 42 

Mimbres Mountains ................ "..... 42 

San Andres Mountains. . . . . . . . . . . . . . . . . . . 42 

Sacramento Mountains........... . . . . . • • . . 43 

Fossils and correlation........ . ............ 43 

34 Devonian system .... . .......................... . 

34 Percha shale ................................. . 

34 General relations ....................... . 

34 Lake Valley and Hillsdale region ........ . 

34 Cooks Range ............................ . 

34 Florida Mountains ....... , ....... . ..... . 

35 Silver City .................. ~ ........ . . . 

35 Caballos Mountains ....................... . 

35 Franklin Mountains .................... . 

35 Sacramento Mountains .. . ................ . 

35 San Andres Mountains .................. . 

35 Fossils .................................. . 

35 Age and correlation .................... . 

35 Carboniferous system ............................ . 

36 General features ....... ~ ..................... . 

36 Lower Mississippian limestones .............. . 

36 Lake Valley region ...................... . 

37 Cooks Range ............................ . 

37 Silver City region ........................ . 

37 Mimbres Mountains ...................... . 

37 Caballos Mountains ....................... . 

38 Magdalena Mountains .. · ................. . 

38 San Andres Mountains .................... . 

38 Sacramento Mountains ................... . 

38 Sierra Ladrones ................... . ...... . 

39 Fossils .................................. . 

39 Magdalena group ............................. . 

39 Cooks Range ............................ . 

40 Silver City region ........................ . 

41 Mimbres Mountains ...................... . 

41 Magdalena Mountains ..... . ............. . 

41 Gym limestone ......................... -• .... . 

41 Hueco limestone ............................. . 

41 Geologic history .............................. . . . 

III 

44 

44 

44 

44 

44 

44 

44 

44 

45 

45 

45 

45 

46 

46 

46 

47 

47 

48 

48 

48 

48 

48 

49 

49 

50 

50 

53 

53 

53 

53 

53 

53 

55 

55 
ILLUSTRATIONS. 

PLATE XIII. Map of part of New Mexico and adjoining regions, showing relations of 

lower Paleozoic rocks ....... _.-.- __ . 

XIV. A, Bliss sandstone in Bennett Canyon, 18 miles northeast of Las 

Cruces, N. · Mex.; B, West face of 

Sandia Mountains at Bernalillo, 

N.Mex .. ---------------------·-· XV. Views on east side of San Andres 

Mountains, west of Alamogordo, 

N. Mex.: A, View looking east out 

of mouth of Hembrillo Canyon; B, 

View looking northeast in Goodfortune Canyon. _________ ... __ .. __ 

XVI. A, West face of Caballos Mountains 

near Apache Canyon, Sierra County, 

N. Mex.; B, Paleozoic rocks on 

granite at Capitol Dome, Florida 

Mountains, Luna County, N.Mex .. 

XVII. A, Sierra Cuchillo west of Palomas 

Springs, N.Mex.; B, Faultin limestone at Palomas Gap, Caballos 

Mountains, Sierra County, N.Mex .. 

XVIII. A, Limestones from Ordovician to 

Pennsylvanian on granite, Sheep 

Mountain, San Andres Mountains, 

Socorro County, N. Mex.; B, ,East 

face of San Andres Mountains at 

Rhodes Canyon, Socorro County, 

N. Mex .. ___ ..... __ .. _ . __ . _ .. ___ _ 

XIX. A, North side of entrance to Alamo 

Canyon, 3 miles southeast of Alamogordo, N. Mex.; B, Kelly limestone 

at Graphic mine, near Magdalena, 

N.Mex ......................... . 

XX. View looking southeast along west 

front of Sacramento Mountains 

from Alamogordo, Otero County, 

N. Mex ... _ ....... __ ......... _ .. . 

XXI. View along west front of Sacramento 

Mountains at Agua Chiquita Canyon, Otero County, N.Mex .. ------

IV 

Page. 

32 

32 

33 

34 

35 

36 

37 

50 

51 

FIGURE 2. 

3. 

4. 

5. 

6. 

7. 

8. 

9. 

10. 

11. 

12. 

13. 

14. 

15. 

Columnar sections showing stratigraphic 

relations of Paleozoic rocks in southern 

New Mexico ....................... . 

Section across the Franklin Mountains 

3 miles north of El Paso, Tex ........ . 

Section across Cooks Range at Cooks, 

N.Mex ............................ . 

Section through the Klondike Hills, 

Luna County, N.Mex ............... . 

Section through the Snake Hills, southwest of Deming, N.Mex ............ . 

Cross section showing relations of Paleozoic rocks in the Silver City region, 

N.Mex ............................ . 

Section across the Caballos Mountains, 

southwest of Engle, N. Mex ........ . 

Sections across the San Andres Mountains, Socorro and Dona Ana counties, 

N.Mex ........................... . 

Section through the Lake Valley mining 

district, Sierra County, N.Mex ..... . 

Columnar sections showing stratigraphic 

variations in lower Paleozoic rocks in 

the San Andres Mountains, Dona Ana 

and Socorro counties, N.Mex ........ . 

Section from the Mimbres Mountains 

eastward through Kingston and Hillsboro, N.Mex ...................... . 

Section of the west front of the Sacramento Mountains, 12 miles southeast 

of Alamogordo, N.Mex ............. . 

Section along western slope of the 

Sacramento Mountains east of Alamogordo, N. Mex., from La Luz Canyon 

to Grapevine Canyon .............. . 

Section across the southern part of the 

Florida Mountains, Luna County, 

N.Mex ............................ . 

Page. 

31 

32 

35 

36 

37 

38 

39 

42 

44 

45 

48 

50 

51 

54 
A COMPARISON OF PALEOZOIC SECTIONS IN SOUTHERN NEW MEXICO. 

By N.H. DARTON. 

INTRODUCTION. 

In studying the geology of different parts 

of southern New Mexico the writer has obtained many new data on the distribution 

and relations of the sedimentary rocks. The 

stratigraphy of the Pennsylvanian series was 

investigated in detail, and in Luna County all 

the formations were studied.1 A recently 

~ 0 

~ z 

0 

a:> 

5 

z 

<{ 

Hueco 

Franklin Mts 

~ Fusselman 

Vi 

z 

~ 

~~ Montoya 

-'0 

a: 

0 

z 

::;~ c:: 5 El Paso <to 

wo a: 

0 

Florida 

Mts. Cooks 

Range Silver 

City 

in publications by Gordon and Graton, Lee, 

Herrick, and others. 

It has been known for some time that in 

southern New Mexico there are representatives of portions of later Cambrian, Ordovician, Silurian, Devonian, earlier Mississippian, 

and Pennsylvanian time, and that the lower 

formations thin out to the north, so that in 

Caballos Mts. Lake 

Valley 

500 

Kingston- San Andres Sacramento Hillsboro Mts. Mts. 

Red beds (Abo) 

.Scale 

0 500 

50 

I,OOOFeet ~~~~------~----~ 

mf Mississippian fossils m Magdalena fossils 

FIGuRE 2.-Colum.nar sections showing stratigraphic relations of Paleozoic rocks in southern New Mexico. 

published folio 2 gives many new facts for the 

stratigraphy of the Silver City region, some of 

which are utilized in the present paper. Richardson's work in the El Paso region 3 established the succession in the southeastern part 

of New Mexico. There are also many details 

I Darton, N. H., Geology and underground waters of Luna County, 

N.Mex.: U.S. Geol. Survey Bull. 618, 188 pp., 13 pl., 1916. 

2 Paige, Sidney, U.S. Geol. Survey Geol. Atlas, Silver City folio (No. 

199), 1916. 

s Richardson, G. B., U. S. Geol. Survey Geol. Atlas, El Paso folio 

(No. 166), 1909. 

central New Mexico the strata of the Pennsylvanian series lie directly on the pre-Cambrian crystalline rocks, as shown in Plate 

XIV, B. There are also numerous irregularities in the overlap relations of the formations. 

The broader features of the stratigraphy of 

this region are here presented. The principal 

Paleozoic formations in southern New Mexico 

are shown in the columnar sections (fig. 2), 

and some conditions of the distribution of the 

formations are indicated on the map (Pl. XIII). 

31 
32 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

CAMBRIAN SYSTEM. 

GENERAL FEATURES. 

The presence of Cambrian strata in New 

Mexico was announced by Gordon and Graton 1 in 1906, on the evidence afforded by the 

discovery of Obolus stoneanus in sandstones on 

the west side of the Caballos Mountains near 

Shandon. In 1910 the name" Shandon quartzite" 2 was given to the beds at _ this place, 

and they were tentatively correlated with the 

Bliss sandstone of the Franklin Mountains, 

near El Paso, Tex.J defined by Richardson 3 in 

1904. Sandstones and other rocks of Cambrian 

age occur at many places in Arizona, where 

apparently they underlie wide areas. The 

name Bliss sandstone has been adopted for 

0 

beds comprise Lingulepis a,cuminata, Obolus 

matinalis ?, and fragments of Lingulella. Some 

relations of the Bliss sandstone in the Franklin Mountains are shown in figure 3. 

Florida Mountains and Cooks Range.-In 

Luna County the Bliss sandstone is similar in 

character, thickness, and relations to the formation in its type locality. It crops out in the 

Florida Mountains and Cooks Range, as well 

as in several outliers, everywhere lying with 

strong unconformity on granite, as shown in 

Plate XVI, B (p. 34), and grading upward into 

the El Paso limestone. Gray to brown sandstone prevails; part of it is quartzitic, but the 

upper beds are slabby and have intercalations 

of sandy and limy shale. The formation contains much glauconite. Its average thickness 

1 MlLE. 

FIGURE 3.-Section across the Franklin Mountains 3 miles north of El Paso, Tex. (After Richardson.) gr, Granite; b, Bliss sandstone; 

e, El Paso limestone; m, Montoya limestone; f, Fusselman limestone. 

southern New Mexico because of its priority 

in the El Paso region. It replaces the name 

"Shandon quartzite." 

BLISS SANDSTONE. 

Franklin _._lfountains.-In its type locality, 

at the east base of the Franklin Mountains, the 

Bliss -Sandstone consists of small grains of 

quartz embedded in a matrix of sericite and 

kaolin. The basal beds are mostly quartzitic 

and locally conglomeratic, and the higher beds 

are softer and finer grained. The prevailing 

color is brown, but some portions have lighter 

tints. A thickness of 300 feet is attained in 

places, but locally the. formation thins out and 

overlying limestones rest on the pre-Cambrian 

rocks. It appears to grade upward into the 

El Paso limestone. Annelid borings are abundant, and a few brachiopods in the lower 

1 Gordon, C. H., and Graton, L. C. , Lower Paleozoic formations in 

New Mexico: Am. Jour. Sci., 4th ser., vol. 21, p. 392, 1906. See also 

Lindgren, Waldemar, Graton, L. C., and Gordon, C. H., The ore deposits of New Mexico: U. S. Geol. Survey Prof. Paper 68, .P· 225, 1910. 

2 Lindgren, Waldemar, Graton, L. C., and Gordon, C. H., op cit., 

p. 225. 

a Richardson, G. B., Report of a reconnaissance in trans-Pecos Texas 

north of the Texas & Pacific Railway: Texas Univ. Mineral Survey 

Bull. 9, p. 27, 1904. 

is 150 feet, but locally it is much thinner. No 

fossils were found in these areas. 

Silver City region.-In the Silver City region 

the Bliss sandstone consists of quartzite and 

limy sandstone containing some glauconite 

throughout. The thickness averages 180 feet, 

but varies somewhat. At most places the 

basal member is quartzite, which grades upward as a rule into fine-grained greenish sandstone but locally into soft ferruginous sandstone, and here and there the greater part of 

the formation is quartzite. At the top there 

is generally a thin quartzite or glauconitic 

sandstone, grading upward into limy sandstone 

that appears to merge with the overlying El 

Paso limestone. A typical section given by 

Paige 4 is as follows: 

Section of Bliss sandstone 7 miles northwest of Silver City, 

N.Mex. 

Feet. 

Sandstone, coarse, glauconitic....... . . . . . . . . . . . . . . 12 

Limestone, sandy; thin, wavy bedding; fucoid 

markings ..................... -.-............... 47 

Quartzite, coarse, slightly cross-bedded............. 17 

Sandstone, limy; thin, wavy bedding; fucoids?.... 57 

4 Paige, Sidney, Geol. Survey Geol. Atlas, Silver City folio (No. 199), 

1916. . 
U.S. GEOLOGICAL SURVEY 

1090. 

LEGEND 

Outcrop of lower 

-

Paleozoic rocks 

(Cambrwn to Ordovician; O'Verlain in most places by Silurian and Devonian and locally by lower Mississippian) 

35 CSJ 

Contact of Cambrian on granite 

rx;:J 

Contact of Mississippian 

~ on granite 

r___:___] 

~ 

Contact of Pennsylvania~ on granite 

VAL 

..... ___ ..... ..... ____ _ 

X 

10 o 10 20 30 40 50 60 70 so 90 100 Miles 

PROFESSIONAL PAPER 108 PLATE XI II 

\,\ 

NEW MEXICO \~~\,, ----------'r"'; 

-:5- TEXAS ;: 

~0 \,' -,, ',,_~~;~:- \ 

0 t.~---:::~~:::::~ ~:;j .:, 1 ' I ... - ... "' I 

-- -A-';S 0 

10:f 

_MAP OF PART OF NEW MEXICO AND ADJOINING REGIONS, SHOWING RELATIONS OF LOWER PALEZOIC ROCKS. 

U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XIV 

A. BLISS SANDSTONE IN BENNETT CANYON, 18 

MILES NORTHEAST OF LAS CRUCES, N. MEX. 

8, Contact of Bliss sandstone and El Paso limestone. 

B. WEST FACE OF SANDIA MOUNTAINS AT BERNALILLO, N. MEX. 

a, Sandia formation on granite, etc. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XV 

A. VIEW LOOKING EAST OUT OF MOUTH OF HEMBRILLO CANYON. 

f, Fusselman limestone; m, Montoya limestone; e, El Paso limestone; b, Bliss sandstone; gr, granite. 

B. VIEW LOOKING NORTHEAST IN GOODFORTUNE CANYON. 

mgr, Microgranite; mg, limestone of Magdalena group; lv, Lake Valley limestone; p, Percha shale; m, Montoya limestone; e,l El Paso limestone; b, Bliss limestone; gr, granite. 

VIEWS ON EAST SIDE OF SAN ANDRES MOUNTAINS. WEST OF ALAMOGORDO, N. MEX. 
. COMPARISON OF PALEOZOIC SECTIONS IN SOUTHERN NEW MEXICO. 33 

Quartzite; massive, cross-bedded, ferruginous, glauconitic; pebbly streaks ......................... . 

Sandstone, soft, glauconitic ....................... . 

Quartzite, massive, coarse (on granite) ........... . 

Feet. miles northeast of Las Cruces, where it is 125 

17 feet thick and lies between granite and the El 

13 Paso limestone. This exposure is shown in 

15 Plate XIV, A. The Bliss is 60 feet thick 2 miles 

178 

The area of outcrop of the formation is small. 

It appears along the west slope of the ridge northwest of Silver City and on some outlyingridges 

and in a small exposure at the west end of LQne 

Mountain, 6 miles southeast of Silver City. 

The beds near the base yielded abundant specimens of Billings ella coloradoensis, an Upper 

Cambrian fossil. 

Caballos Mountains.-The Bliss sandstone in 

the Caballos Mountains has been described by 

Gordon and Graton 1 and by Lee. 2 As explained above, the beds at this place were 

called "Shandon quartzite." They lie on a 

smoo~h plane on granite, which is exposed to a 

height of about 1,000 feet above the Rio Grande 

on the west slope of the range, as shown in 

figure 8 (p. 39) and Plate XVI, A (p. 34). 

Gordon and Graton described a thin basal 

member of dark quartzite, absent in places; 

white quartzite 4 to 5 feet thick; and an upper 

member, 40 feet thick, of dark-brown and green 

sandy shales and thin-bedded quartzite carrying Obolu_s. The beds recorded by Lee in a 

section 3 miles north of Shandon consist of a 

basal quartzite 10 feet thick, in places conglomeratic, grading upward into 90 feet of 

dark-green shale. The shale yielded Obolus 

( Westonia) stoneanus, Obolus sinoe?, Eoorthis 

desmopleura, and Lingulella acutangulata?, determined by C. D. Walcott and regarded as 

Upper Cambrian. A similar section was observed by Lee in Cerro Cuchillo, near Palomas 

Spring. (See Pl. XVII, A, p. 35.) In both 

places the overlying limestone is the El Paso. 

Lee states that the basal quartzite thickens to 

300 feet 8 miles south of Shandon. 

San Andres Mountains.-The Bliss sandstone 

crops out continuously along the east slope of 

the San Andres Mountains, but it becomes 

very thin in the north end of the range. (See 

figs. 9, p. 42, and 11, p. 45.) The formation is a 

conspicuous feature in Bennett Canyon, 18 

1 Am. Jour. Sci., 4th ser., vol. 21, pp. 391-392, 1906; U.S. Geol. Survey 

Prof. Paper 68, pp. 225-226, 1910. 

2.Lee, W. T., Notes on the lower Paleozoic rocks of cimtral New Mexico: 

Am. Jour. Sci., 4th ser., vol. 26, pp. 180-181, 1908. 

northeast of Organ, where it is cut off by igneous rocks. At this locality the rocks are 

sandstone, mostly hard, and many layers 

contain considerable glauconite. In San Andres Canyon the formation comprises 110 

feet of beds, consisting of a lower member of 

gray quartzite, mostly massive; a medial member of brown sandstone, partly slabby; and 

an upper slabby member that apparently 

merges with the base of the El Paso limestone. 

In the central part of the range, at Deadman 

and Hembrillo canyons, the thickness is from 

30 to 40 feet. (See Pl. XV.) In Sulphur 

Canyon it consists of 25 feet of brown sandstone, conglomeratic at the base, grading upward into 30 feet of thin, slabby softer sandstone, in part glauconitic, which appears to 

grade into slabby, finer sandstone, and this in 

turn into an impure buff slabby limestone that 

is certainly the El Paso. In Rhodes Canyon 

the sandstone that separates the El Paso beds 

from the granite is 6 feet thick, and this thin 

deposit extends northward, as shown in Plates 

XV, B, and XVIII, A (p. 36). 

Sacramento Mountains.-In the small exposure of the base of the sedimentary rocks 

just south of the mouth of Agua Chiquita Canyon, in the Sacramento Mountains, the El Paso 

limestone is separated from a dark granite by 

a few feet of hard sandstone, which is presumably Bliss.· It is not especially characteristic, 

however, and yielded no fossils, so that the 

correlation can be only tentative. 

Mimbres Mmtntains.-According to Gordon/ the limestone in the east slope of Mimbres 

Mountains is separated from the granite by 

quartzite, which undoubtedly represents the 

Bliss sandstone. (See fig. 10, p. 44.) Exposures on Carbonate Creek show 75 feet of darkred quartzite, which includes a 3-foot bed of 

shale near the middle and rests on an irregular 

surface of red granite. In most of. the slopes 

of these mountains the basal formations of the 

sedimentary series are hidden by younger 

igneous rocks, which cap the range; 

a U. S. Geol. Survey Prof. Paper 68, pp. 268, 269, 1910. 
34 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

ORDOVICIAN SYSTEM. 

GENERAL FEATURES. 

Ordovician rocks were first discovered in the 

Southwest by G. G. Shumard in 1856/ :Who 

found fossils now known to be charactenstic of 

the Ordovician in the Franklin Range at El 

Paso . . Some years later the geologists of the 

Wheeler Survey 2 found similar fossils at .several localities, including the vicinity pf Silver 

City, N. Mex. 

Gordon and Graton 3 found other fossiliferous localities in southern New Mexico in 1905. 

The beds of Ordovician age which they describe are about 750 feet thick, and in 1910 

these beds, -together with a Silurian li~estone 

that overlies them in places, were designated 

the "Mimbreslimestone."4 All these limestones 

are well represented in the Franklin Mountair~s 

north of El Paso, where Richardson 5 subdivided them into the El Paso and Montoya 

limestones, of Ordovician age, and the Fusselman limestone of Silurian age. As these ' . formations are separable throughout southern 

New Mexico the name "Mimbres limestone" ' . is no longer useful. Throughout the regwn 

the middle part of the Ordovician and the lower 

part of the Silurian appea: to .be absent. 

The Ordovician successiOn In southern New 

Mexico shows everywhere uniform and very 

marked characteristic features. They are wonderfully distinct at the many widely scattered 

exposures examined by the W:i ter, f:om the 

Franklin Mountains west to Silver City, and 

to the north in Cooks Range, Lake Valley, and 

the San Andres, Caballos, and Sacramento 

mountains. TheEl Paso limestone, at the base 

of the section is in most places of unmistakable 

character it~ conspicuous features being thin 

bedding, 'a light color on weathering, ~nd brownish-buff reticulations on the bedding 

pl~nes, caused by irregular layers of an iro~­

silica deposit probably due to a seawe~d. !his 

formation is overlain by dark massive hmestone at the base of the Montoya; locally a thin 

sandstone separates the two limestones, and 

everywhere there is a sharp break. The upper 

member of the Montoya invariably consists of 

alternating layers of limestone and chert carrying abundant Richmond fossils. 

EL PASO LIMESTONE. 

Franklin Mountains~-The El Paso limestone 

was separated from other Ordovician strata 

in the Frank:Jin Mountains north of El 

Paso by. Richardson.6 In the type locality 

the formation consists of about 1,000 feet of 

gray limestone mostly massive but in part 

slabby. The lower 100 feet contains some 

sand and weathers brown. Where it is in contact with pre-Cambrian rocks the basal member 20 feet thick consists of round pebbles of 

porphyry in a liiny matrix. In the middle of 

the formation occur thin connected nodules of 

brown chert in streaks parallel to the bedding, 

but this feature, characteristic here, was not 

observed in other regions. Magnesia is a 

general constituent in variable amount. The 

principal outcrop is along the eastern f:lan~ of 

the Franklin Mountains, where the relatwns 

are those shown in figure 3 (p. 32). Distinctive 

Lower Ordovician fossils were found in the 

formation at many places. _ 

Florida Mountains.-The El Paso limestone 

is extensively exposed in the south-central 

part of the Florida Mountains and also on the 

northwestern slope of that range a short distance southwest of Deming. (See Pl. XVI, B.) 

At the latter place the thickness is about 800 

feet and the lower 140 feet is darker and more 

massive than in other outcrops. The greater 

part of the formation consi~ts of light-g;ray 

slabby dolomitic limestone With pale reddishbrown blotches over the bedding planes. 

There is very little chert. The upward gradation from the Bliss sandstone is well marked, 

and the change to the overlying Montoya limestone is abrupt. The structural relations in 

the southern part of the range are shown in 

fiaure 15 (p. 54). 

· 

0 

Oooks Range.-At the north end of Cooks 

Range and in Fluorite Ridge, at its south end, 1 Shumard, G. G., A partial report on the geology of western Texas, the El Paso is well exhibited. The northern 

p 103, Austin, 1886. exposures show 600 feet of beds between the .2 u.s. Geog. and Geol. Expl. w. 100th Mer. Rept., vol. 3, PP· 515-517, Bli"ss sandstone and the sandstone member at 1875. 

a Am. Jour. sci., 4th ser., vol. 21, pp. 392-393, 1906. the base of the Montoya. The relations near • U.S. Geol. Survey Prof. Paper 68, p. 226, 1910. . 

5 Richardson, G. B., U. S. Geol. Survey Geol. Atlas, El Paso foho 

(No. 166), 1909. au. s. Geol. Survey Geol. Atlas, El Paso folio (No. 166), 1909. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XVI 

A. WEST FACE OF CABALLOS MOUNTAINS. NEAR APACHE CANYON, SIERRA COUNTY, N. MEX. 

Looking northeast. gr, Granite; b, Bliss sandstone. 

B. PALEOZOIC ROCKS ON GRANITE AT CAPITOL DOME, FLORIDA MOUNTAINS, LUNA COUNTY, 

N. MEX. 

Looking northeast. ag, Agglomerate; m, Montoya limestone; e, El Paso limestone; gr, granite. 
U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XVII 

A. SIERRA CUCHILLO WEST OF PALOMAS SPRINGS, N. MEX. 

Looking northwest. Granite, Bliss sandstone, Ordovician and Pennsylvanian limestones. 

B. FAULT IN LIME:STONE AT PALOMAS GAP, CABALLOS MOUNTAINS, .SIERRA COUNTY, N. MEX. 

, Looking north. 
COMPARISON OF PALEOZOIC SECT'IONS IN SOUTHERN NEW MEXICO. 35 

Cooks are · shown in figu1e 4. In Fluorite 

Ridge, 12 miles north of Deming, the beds are 

so crushed and faulted that only about 400 

feet of the El Paso limestone appears. 

Snake Hills.-The east end of the Snake Hills, 

a small range rising out of the desert a few 

miles southwest of Dem'ing, consists of El 

Paso limestone showing distinctive features 

and fossils. The base of the formation is not 

exposed, but to the west, ak shown in figure 6 

(p. 37), its top passes uhder the Montoya 

limestone with marked unconformity. 

Victorio ·Mountains.-The knob constituting 

the northeastern member of the Victorio 

Mountains presents extensire exposures of El 

Paso limestone, 600 to 700 feet .thick at least, 

dipping south toward a mass of Montoya limestone which constitutes m:uch of Mine HilL 

The El Paso beds presen~ the usual slabby 

character, weather to a light color, and show 

f 

nearly the same distribution as the Bliss sandstone in Lone Mountain in the Silver City 

Range, northwest of Silver City, and In an 

area north of Bear Mountain. 

Caballos Mountains.-The El Paso limestone is a prominent feature in the great 

section along the west front of Caballos 

Mountains, where it has the relations shown 

in figure 8 (p. 39) and Plate XVI, .A. The 

Bliss sandstone grades upward into ·the El 

Paso, and above it are typical cherty beds of 

the Montoya limestone. It constitutes 300 or 

400 feet of the , lower part of the limestone 

cliffs, . and the rocks present the same characteristics that . are seen in . the · Franklin 

Mountains and Luna County. However, Lee 1 

notes a section 8 miles south of Shandon in 

which it consists of 200 feet of cherty limestone, overlain unconformably by 500 feet of 

cherty limestone (Montoya and later). CharHor izbon~;,··~~~~;- gr - P f V€rtical scale . . 1 0 ~MILE 0 4,000FEET 

e - -~-=~~~-=-~~:~=-~-=-=~ ~-:o=:~_j f3~~J,~~t~~!ii:~~r~ 

FIGURE 4.-Section across Cooks Range kt Cooks, N.Mex .. gr, Granite; b, Bliss sandstone; e, El Paso limestone; m, Montoya limestone; 

f, Fusselman limestone; p, Percha shale; lv, Lake Valley limestone; g, Gym limesful· ne; 1, Lobo formation; s, Sarten sandstone (Cretaceous); ag, agglomerate. 

abundant pale-brown reticulations on the bed- . acteristic [ossils were fomid by Lee in both 

ding planes. formations 

Klondike Hills.-The Klondike Hills, 12 Lake v;, lley district.-The lower 150 feet 

miles south of the Victorio, Mountains, consist of the limrstone in Quartzite Ridge, on the 

mainly of the El Paso and Montoya lime- west side f the Lake Valley mining district, 

stones, the former mostly i!n the western part is made · of El Paso beds. On the east 

of the ridge as shown in fig-qre 5. At one place these bed are overlain . by 20 feet of hard 

the underlying Bliss sandstone· is exposed. sandstone at the base of the Montoya limeThe thickness is about 650 feet and all the stone, and on the west they are cut off by 

usual features are presented. At the top there igneous r cks. The relations are shown in 

is an unconformable overlap of sandy beds at figure 10 (p. 44). The rocks are the highly 

the_ base of the Monto~a ~i~estone~ but the ch~racteris ic slabby ~imestone, weathering. to 

attitude of both formatiOns IS practically the a h.ght col r and having mos.t of the bedding. same. planes sta ned with brownish reticulations. 

Silver Oity region.-In the vicinity of Silver Mimbres Mountains.-Gordori and Graton 2 

City the El Paso limestonff is mostly gray or report an extensive section of Ordovician 

grayish blue and in part fagnesian. It ap- rocks in tiT. ¥imbres Mountains near Kingston. 

pears to grade upward from the Bliss sandstone, At this ace the lower division doubtless 

the lowermost 100 feet becoming progressively represents the El Paso limestone, but it is 

less sandy. The lower and middle parts are mostly a ~lue and white marble, and the dis-

. slabby, and the slabs have the characteristic tinctive. fo~si·ls were not found. On Carbonate 

mottled surface seen -in o~her areas. In the Creek the basal limestone is exposed in conupper part the formation is more massive and tact with andstone of Cambrian age (Bliss). 

contains considerable cliertj. The total thickf f 1 A . Jour. ScL, 4th ser., vol. 26, p. 180, 1908. 

ness is about 900 eet. The ormation has 2 Ide , vol. 21, p. 392, 1906. 

76787°-17-· -2 
36 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

San Andre~ .Jlountains.:_The El Paso lime- beds are more massive than at most other · 

stone extends continuously along the east face localities. 

of the San Andres Mountains, from the igneous Fossils.-Fossils occur in the medial and 

contact near Organ to the north end of the upper beds of the El Paso limestone at all 

range. Its relations are shown in figures 9 localities, but they are not numerous either 

(p. 42) and 11 (p. 45). (See also Pis. XV and individually or in species. A small coiled shell, 

XVIII, B.) Its thickness is about 300 feet at Ophileta, is by far the most common form. 

the south but gradually diminishes northward Richardson 1 found the fauna very meager in 

from San Andres Canyon to 160 feet on Lost- the Franklin Mountains but collected Ophileta 

man Canyon, 125 feet ·at 'Rhodes Canyon, and and other gastropods, and also cephalopods 

80 feet in Lava G~p. In Sulphur Canyon, related to Piloceras and Oameroceras. Higher 

which is nearly due west of Tularosa, it is 160 beds near Deming have yielded a form refeet. The limestone lies on or grades upward sembling Dalmanella pogonipensis, Strophofrom the Bliss sandstone and has characteristic mena near S. nemea, Hormotoma sp., and 

slabby structure with the slabs weathering Trochonema. In the Silver City region the 

light gray and having surfaces mottled with fossils collected by Paige 2 were Oalathium 

reticulations of brownish-buff markings, prob- anstedi, Dalmanella cf. D. wempeli, Protoably due to a seaweed. Locally the medial warthia cf. P. rossi, Bucamella nana?, Lophobeds are massive and less distinctive in appear- spira sp., Raphistoma trohiscum?, Eccyliopterus 

ance. Fossils were found at many places. sp., Maclurea cf . . M. oceana, Holopea sp., 

The relations 18 mi~s northeast of Las Cruces Piloceras cf. P. wortheni, Oameroceras, an~ the 

FIGURE 5.-Section through the Klondike Hills, Luna County, N. Mex. gr, Granite; b, Bliss sandstone; e, El Paso limestone; m, Montoya 

limestone with sandstone (s) at base; r, rhyolite. 

and in _Lava Gap are shown in figure 9 (p. 42). 

The formation is conspicuous in Rhodes 

Canyon, a few miles south of Salinas· Peak 

(see Pl. XVIII, B), in about latitude 33° 10', 

where it is separated from the granite by only 

6 feet of sandstone, and this relation continues 

to the north el\d of the range. 

Sacramento Mountains.-The basal limestone 

in the west front of the Sacramento Mountains from Alamo Canyon to a point · near 

. Grapevine Canyon is typical El Paso, showing all the features distinctive in other areas, 

including fossils. The relations are shown in 

figures 13 (p. 50) and 14 (p. 51). The thickness is 250 feet, but except in a small area near 

the mouth of Agua Chiquita Canyon the basal 

beds are covered by talus. In Alamo Canyon 

125 feet of the El Paso is well exposed in the 

cliff on t4e north side of the creek, capped by 

thin sandstone and dar~ massive limestone at 

. the base of Montoya; as shown in Plate XIX, A 

(p. 37). At _Dog Canyon 200 feet is exposed. 

The rocks are slabby limestones, weathering 

to a light tint, and in part the bedding planes 

show brownish-buff reticulations. The medial 

usual Ophileta . . In the Caballos Mountain 

section Lee 3 collected Ophileta cf. 0. complanata and H ormotoma cf. H. artemesia. In 

the exposure in Bennett Canyon in the San 

Andres Mountains, 15 miles northeast of Las 

Cruces, were obtained Polygyrata ro~uliformis? 

and an indeterminable cystid. In the canyon 

3 miles south of San Andres Peak were collected Oalathium cf. 0. anstedi, Polygyrata 

trohiscus, and Piloceras sp. In San Andres 

Canyon Oalathium cf. 0. anstedi was found and 

this distinctive fossil was observed throughout 

the exposures in the San Andres Range. From 

the cliff in Alamo Canyon, in the Sacramento 

Mountains, were collected Oalathium cf. 0. 

anstedi and Dalmanella pogonipensis. 

Age and correlation.-The fossils in the El 

Paso limestone are regarded_ by Ulrich and 

Kirk as Lower Ordovician, representing late 

Beekmantown time. It is possible that in 

some ar~as strata of early Chazy age have been 

included with the El Paso. On this basis the 

1 U.S. Geol. Survey Geol. Atlas, El Paso folio (No. 166), p. 4, 1909. 

t Idem, Silver City folio (No. 199), p. 4, 1916. 

· a Am. Jour. Sci., 4th ser., vol. 26, p. 180, 1908. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XVIII 

A. LIMESTONES FROM ORDOVICIAN TO PENNSYLVANIAN ON GRANITE, SHEEP MOUNTAIN, SAN 

ANDRES MOUNTAINS, SOCORRO COUNTY, N. MEX. 

Looking south. lv, Lake Valley limestone; p, Percha shale; m, Montoya limestone; e, El Paso limestone;gr,granite. 

B. EAST FACE OF SAN ANDRES MOUNTAINS AT RHODES CANYON, SOCORRO COUNTY, N. MEX. 

p, Percha shale; m, Montoya limestone; e, El Paso limestone on Bliss sandstone; gr, granite. 

-------- -------------------------------------------------~ 
38 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

highly cherty rock at the crest of the ridge. 

In the Klondike Hills (see fig. 5, p. 36) the 

basal member is a dark-gray sandstone, 6 to 8 

feet thick, lying on the slightly irregular surface of the El Paso limestone. It is overlain 

by 30 to 40 feet of dark massive sandy limestone, capped as in other areas by a succession 

including two or three thick cherty members 

with limestone layers that contain many 

fossils, listed on page 40. 

Silver City region.-The first observers of the 

Montoya limestone in southwestern New 

. Mexico were Howell and Gilbert, 1 who in 

1873 collected "Cincinnati" fossils from limestones near Silver City and in the Santa Rita 

Range. 

In the Silver City area the M'ontoya limestone shows its characteristic features and has 

a thickness of about 300 feet. · Its relations in 

the ridge west of Silver City are shown in 

NW. 

cliff yielded distinctive fossils. Between this 

cherty member and the limestone containing 

Pennsylvanian fossils is 500 feet of limestone 

whose age was not determined. Lee 2 also 

reports outcrops of the cherty limestone in the 

Sierra Cuchillo, near Palomas Springs, west of 

the Rio Grande (see Pl. XVII, .A), and in the 

north slopes of Robledo Mountain, 15 miles 

south of Rincon, but the fossils· collected at the 

latter locality appear more probably to be 

Fusselman. 

Lee 2 reports that the cherty limestone carrying distinctive Montoya fossils is exposed in the 

south end of the Caballos Mountains, 8 miles 

south of Shandon, but the rocks are so faulted 

and crushed that it is difficult to make a section. Below these cherty beds is limestone containing El Paso fossils. In exposures along the 

same line of outcrop, about 6 miles west of 

Rincon, 300 feet of cherty limestone exposed at 

• 

0 I MILE 

FIGURE 7.-Cross section sliowing relations of Paleozoic rocks in the Silver City region, N.Mex. (After Paige.) gr, Granite, etc.; b, Bliss 

sandstone; e, El Paso limestone; m, Montoya limestone; f, Fusselman limestone; p, Percha shale; fr, Fierro limestone; K and Kc, sandstone 

and shales of Cretaceous age. 

figure 7. Although most of the formation is 

limestone, it contains a large amount of chert, 

mainly in thin beds interlaminated with the 

limestone. One member of this character, 80 

feet thick, begins about 40 feet above the top 

of the El Paso limestone, from which it is 

separated by magnesian limestone. The base 

is not distinct. Above the thick chert members are alternating thin beds of smooth 

whitish limestone and massive beds of blue 

limestone with cherty layers at intervals. 

Fossils of the Richmond fauna are abundant, 

especially in two layers, one near the base and 

the other near the top of the formation. . 

Caballos Mountains and adjoining regions.-

In the Caballos Mountains, southwest of Engle, 

the Montoya limestone is extensively exposed. 

Lee 2 has given many details of its features, 

with a list of fossils determined by Ulrich. In 

a section 3 miles north of Shandon, shown in 

figure 8 and Plate XVI, .A, the cherty lime-· 

stone near the top of the first great limestone 

1 U.S. Geog. and Geol. Expl.1oothMer. Rept., vol.3, pp.515-517, 1875. 

2 Am. Jour. Sci., 4th ser., vol. 26, pp. 181-182, 1908. 

the foot of the cliffs yielded a number of 

Montoya fossils. Apparently here, as elsewhere, the Montoya lies directly on the El 

Paso limestone, no intermediate Ordovician 

rocks being present. 

Lake Valley.-Lying on the El Paso limestone in the west front of Quartzite Ridge, west 

of Lake Valley, is 20 feet of gray hard sandstone, above which is 25 feet or more of cherty 

and brecciated limestone that doubtless represents the Montoya. No fossils were found here. 

The relations are shown in figure 10 (p·. 44). 

Next above is 80 feet of compact limestone that 

weathers to a very light color and is similar to 

beds which are tentatively included in the 

Fusselman in other uplifts. Apparently it 

. does not contain fossils. 

Mimbres Mountains.-According to Gordon 

and Graton, 3 the Ordovician limestones outcrop at intervals along the east slopes of the 

Mimbres Mountains from the vicinity of 

Kingston to and beyond Hermosa. From 

Hillsboro southward the upper siliceous beds, 

a Am. Jour. Sci., 4th ser., vol. 21, p. 392, 1906. 
COMPARISON OF PALEOZOIC SECTIONS IN SOUTHERN NEW MEXICO. 39 

including the silicified portions of the overlying shale, appear at many places in irregular 

reefs projecting above the surface of the ground 

or as J.edges capping escarpments. In the 

canyon of the Rio Percha, about a mile east of 

Hillsboro, the "upper limestone" is overlaid 

unconformably by a bed of red and white 

conglomeratic quartzite 6 to 10 feet thick, 

containing nodules that are possibly phosphatic. This stratum is overlain by a reddishbrown compact siliceous rock which may be 

a secondary deposit. Some of the strata carry 

Richmond fossils, but the limit of beds that 

should be classed as Montoya is not indicated. 

San Andres Mountains.-The Montoya limestone is a pro min en t feature in the great eastward-facing escarpment of the San Andres 

Mountains. It appears on the north side of 

the igneous mass of the Organ . Mountains and 

extends continuously northward to the north 

end of the range, where it thins out. It lies 

limestone ledge forms a high cliff of dark color 

and in places makes a shelf or bench along the 

mountain front, as shown in Plates XV and 

XVIII, B. 

Sacramento Mountains.-The dark ledges of 

Montoya limestone are a prominent feature in 

the great series of limestones exposed in the 

higher part of the Sacramento uplift from the 

vicinity of Alamo Canyon to a point near 

GrapeVine Canyon. The relations are shown 

in figures 14 (p. 51) and 15 (p. 54). 

The two members that occur in the San 

Andres and Franklin mountains and other 

uplifts present characteristi_c features. The upper one, 60 feet thick, consists largely of alternating thin beds of chert and limestone with 

abundant Richmond fossils. The lower member is a dark-colored very massive limestone 

which crops out as a high cliff; its thickness is 

75 feet at Dog Canyon and 120 f,eet at Alamo 

Canyon. At the latter place (see Pl. XIX, A) 

FIGURE 8.-Section across the Caballos Mountains, southwest of Engle, N. Mex. gr, Granite; b, Bliss sandstone; e, El Paso limestone; m, 

Montoya limestone; f, Fusselman limestone (?); p, Percha shale (?); lv, Lake Valley limestone (?); mg, limestone of Magdalena group; 

c, Cretaceous sandstone. 

on the El Paso limestone throughout this area, its base is gray sandstone and it is separated 

and it is overlain by the Fusselman limestone from the underlying El Paso beds by an 

to the south, as in the Franklin Mountains, and abrupt change in character of material and 

by the Percha shale north of the latitude of apparently there is a slight channeling of the 

Tularosa. The principal features of thickness, surface of the older formation. 

stratigraphy, and relations to other formations Fossils.-The fossils found in the Montoy.a 

are shown in figure 11 (p. 45). Some features limestone in the Franklin Mountains, north of 

are also shown in figure 9 (p. 42). El Paso, were identified by E. 0. liTrich. The 

Two members are everywhere present-an fossils in the lower part comprised Receptaupper member of alternating thin beds of chert culites near R. oweni, Maclurina manitobensis, 

and limestone, averaging about 75 feet in I and Hormotoma major ( ?). The fossils In the 

thickness but thinning to 30 feet at Hays Gap; upper part are as follows: 

and a lower member of very massive dark- St t 1 t. 

I . . rep e asma rus 1cum. 

co ored limestone, about 100 feet thick, except Hemiphragma imperfectum. 

north of Rhodes Canyon, where it thins grad- Monotryprella quadrata. 

ually. The lower member includes locally at Strophomena fl.exuosa. 

its base a sandstone that lies on the slightly Leptaena unicostata. 

uneven surface of the El Paso beds. This bed Dinorthis subquadrata. 

is 9 feet thick in the slopes 3 miles south of San Platystrophia acutilirata. . . · Rhynchotrema capax. Andres Peak and 15 feet thiCk Ill San Andres Orthis near o. davidsoni. 

Canyon. At all places there is a sharp break Plectorthis whitfieldi. 

at the base of the Montoya. The Montoya Parastrophia divergens. 
40 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

These fos'sils are all of Richmond age. The 

fossils from· outcrops in Luna County, as identified by Mr. Ulrich, comprise the following: 

Eurydictya cf. E. montifera. 

Dinorthis subquadrata. 

Plectorthis whitfieldi. 

Herbertella occidentalis. 

Dalman ella cf. D. meeki. 

Dalmanella near D. jugosa. 

Platystrophia acutilirata var. 

Strophomena cf. S. subtenta. 

Rafinesquina loxorhytes. 

Leptaena unicostata. 

Plectambonites saxea. 

Rhynchonella anticostiensis. 

Rhynchotrema capax 

Rhynchotrema perlamellosa. 

Zygospira recurvirostris. 

Streptelasma rusticum. 

Cyrtodonta sp. 

Vanux:emia sp. 

Bumastus sp. 

These forms are characteristic of the Richmond fauna that occurs in many parts of the 

Rocky Mountain region. No fossils were 

found in the basal dark massive member. 

In the Caballos Mountains Lee 1 collected 

Rafinesq_uina cf. R. kingi, Plectambonites saxea, 

Plectambonites n. sp., Favosites asper, Zygospira 

recurvirostris, Rhynchotrema . capax, Oalapoecia 

canadense, and Platystrophia dentata var. 

Many fossils were collected by Paige 2 in the 

Silver City area near the base and near the top 

of the formation. The following were determined by E. 0. Ulrich: 

Streptelasma. 

Columnaria alveolata var. 

Cohimnaria vicina. 

Tetradium sp. nov. 

Favosites asper. 

Favosites cf. F. a13per. 

Stromatocerium huronense. 

Dicranopora cf. D. fragilis. 

Plectorthis kankakeensis. 

Dalmanella tersa (?). 

Dinorthis sp. 

Dinorthis subquadrata. 

Hebertella sinuata. 

Platystrophia n. sp., near P. acutilirata 

Strophomena sp. ' 

Rhynchotrema capax. 

Rhynchotrema anticostiensis. 

Rhynchonella neenah. 

Ctenodonta cf. C. coata. 

Conradella sp. 

Lophospira cf. L. perangulata. 

L. medialis. 

lAm. Jour. Sci., 4th ser., vol. 26, p. 181, 1908. 

2 U.S. Geol. Survey Geol. Atlas, Silver City folio (No. 199), p. 4, 1916. 

From the basal beds were collected Eridotrypa mutabilis 0), Batostoma cf. B. varium, 

Dalmanella testudinaria var., and Zygospira 

recurvirostra var. 

In the vicinity of Hillsboro Gordon 3 obtained 

some corals identified by Ulrich as Oolumnaria 

alveolata, Favosites asper (late Ordovician 

variety), and Stromatocerium cf. S. pustulosum, 

regarded as Richmond. 

In the San Andres Range fossils were collected at several localities. One ledge of che-rty 

limestone in Sulphur Canyon yielded the following, determined by Edwin Kirk: 

Bythopora gracilis. 

Bythopora cf. B. meeki. 

Bythopora striata. 

Monotrypella quadrata. 

Eridotrypa sp. 

Dalmanella sp. 

Zygospira recurvirostris (Richmond variety). 

Calymene. 

In the canyon 3 miles south of San Andres 

Peak Dinorthis subq_uadrata was found, and in 

Cottonwood and Rhodes canyons were collected numerous specimens of Dalmanella testudinaria var. 

Along the west front of the Sacramento 

Mountains fossils are abundant in the cherty 

layers of the upper member and many corals 

are scattered through thelower massive dark 

limestone. From the lower member near Dog 

Canyon were obtained Halysites gracilis, Streptelasma sp., Receptaculites sp., and Rhynchotrema capax. The cherty member at this 

locality yielded abundant DalTfl:anella cf. D. 

corpulenta. 

Age and correlation.-Most of the fossils collected in the Montoya limestones are species 

common in the Richmond of the Mississippi 

Valley and indicate that the formation comprises two, or possibly three, representatives of 

the Richmond epoch. The lowest may be 

c·orrelated with the Fernvale of the Mississippi 

Valley, the lower part of the Bighorn dolomite 

of Wyoming, the Whitewood limestone of the 

Black Hills, and the middle of the Fremont 

limestone of eastern Colorado. The upper part 

of the Montoya may be correlated with some 

portion of the upper Bighorn and probably 

with the upper part of the Fremont and with 

the Stony Mountain limestone of Manitoba. 

It is not represented in the Black Hills and· 

apparently not in the Mississippi Valley. The 

aU. S. Geol. Survey Prof. Paper 68, p. 2Z'I, 1910. 
COMPARISON OF PALEOZOIC SECTIONS IN SOUTHERN NEW MEXICO. 41 

Montoya is equivalent to part of the Lone 

Mountain limestone ·of Nevada. Apparently 

the formation is absent in Arizona. 

SILURIAN SYSTEM. 

FUSSELMAN LIMESTONE. 

Franklin Mountains and eastward.-The existence of rocks of Silurian age in New Mexico 

was discovered by Gordon and Graton, 1 who 

found fossils at Silver City in 1905.1 Their 

presence in the Franklin Mountains north of 

El Paso was announced by Richardson 2 in 

1904, in a formation which he later designated 

the Fusselman limestone. 3 It is found that this 

limestone is separable in many parts of southern 

New Mexico. 

In its type locality the Fusselman limestone 

is estimated to be about 1,000 feet thick and is 

of considerable topographic prominence, cap-

. ping the range for several miles and appearing 

in a number of detached knobs. It also crops 

out in the Hueco Mountains, 3 miles east of 

El Paso. The rock is mostly a massive lightcolored magnesian limestone. Fossils are 

scarce on the whole, but they abound at a few 

horizons, especially a characteristic Pentamerus 

that indicates upper Niagara age. 

The upper limit of the Fusselman is indistinct, and a thin representative of the Devonian 

or Mississippian may possibly be present at the 

top. In · an exposure 5! miles west of south 

from Hueco Tanks, 30 miles northeast of 

El Paso, white limestone containing Silurian 

fossils is overlain by 100 feet of thin-bedded 

gray limest,one in which n~ fossils ·were found.' 

This formation dips much more steeply than 

the one below it. Overlying it with the same 

steep dip are beds that carry Pennsylvanian 

fossils. In the Hueco Mountains a similar thinbedded gray to purplish limestone that contains 

some chert and weathers buff separates the beds 

containing Silurian and Pennsylvanian fossils 

and dips at a less angle than the Silurian. On 

the northwest flank of the Franklin Mountains, 

however, thin-bedded cherty limestone containing Pennsylvanian fossils overlies the 

Fusselman without discordance of dip. In the 

Van Horn area, farther east in Texas, Silurian, 

Devonian, and Mississippian representatives 

are absent. ·· 

1 Am. Jour. Sci., 4thser., vol. 21, p. 394,1906. 

2 Texas Univ. Mineral Survey Bull. 9, p. 31, 19(}1, 

~Am. Jour. Sci., 4th ser., vol. 25, pp. 479-480, 1908. 

The Fusselman limestone lies on the Montoya 

limestone without conspicuous unconformity; 

at one locality 2 miles north of El Paso its lower 

layers carry small pebbles of black limestone 

similar to some that · occurs in certain beds of 

the Montoya. ·-· _ 

Cooks Range.-The Fusselman limestone is 

well ·developed in the Cooks Peak mining district, where it is the principal rock containing 

the ores of tdtd?,''silver, and zinc. It crops out 

extensively along the road from Cooks to the 

mountain top and along the slopes 2 miles to 

the north. It is a massive gray limestone of 

exceptionally hard, compact texture, but its 

upper part is cavernous in places, and in the 

cavities, a short distance below the Percha 

shale, most of the rich ore pockets have been 

found. In this region the thickness of the 

formation is about 200 feet. The distinctive 

Pentamerus occurs in places. The limestone 

appears in the south end of the range, near the 

fluorspar mines, bu~ its relations are obscure 

owing to igneous intrusions and faults. 

Florida Mountains.-In places in the southern half of the Florida Mountains the Fusselman 

limestone is absent in the varied overlaps. The 

Percha shale apparently is also absent, and the 

Fusseiman limestone where present is overlain 

by the Gym limestone. . 

Victoria Mountains.-The Montoya limestone in Mine Hill is overlain by the Fusselman 

limestone which constitutes the summit and 

west side' of the hill. The silver ore deposits 

occur in this limestone, as in the Cooks Peak 

district. Its thickness appears to be somewhat 

more than 100 feet, but the top may be eroded. 

In other ridges to the west it is cut off by faults 

and also hidden by overlapping Gym limestone. 

Silver City region.-In the Silver City region 

the Fusselman limestone consists of 30 to 40 

feet of gray limestone and dolomitic be_ds, 

not plainly separated from the underlying 

Montoya. In its upper part there are abundant 

casts of the characteristic Pentamerus. 

Caballos Mountains.-Above the massive 

cherty limestone with Montoya fossils in the 

Caballos Mountains Lee 4 found 500 feet of 

white to brown limestone, cherty in places, 

from · which ;no fossils . were obtained. These 

beds extend :to the base of the limestone that 

carr1es Pennsylvanian fossils, and doubtless 

they include the· Fusselman an~ possibly also 

1 Idem, vol. 26; p. 181. 
42 SHORTER CONTRIBUTIONS -TO GENERAL GEOLOGY, 1917. 

strata of Devonian and Mississippian age. In 

the slopes 8 miles south of Shandon 300 feet of 

black shale, probably the Percha, is present in 

the section, and very likely it is, as usual, 

underlain by the Fusselman. 

Robledo Mountain.-ln a small exposure of 

cherty limestone not far below Pennsylvanian 

limestone on the northern slope of Robledo 

Mountain, 5 miles south of Rincon, Lee 1 

obtained Lophospira, Trochus?, Bucania?, Trochonema, Eotomaria, and a pen tameroid shell, 

all suggestive of Silurian age and if so indicating the Fusselman limestone. 

tinctive fossils were collected. The upper 

member is probably the 12 feet of pink limestone referred to by Gordon/ who obtained 

from it some fragments of corals regarded as 

Silurjan by Ulrich. According to Keyes 3 this 

limestone is dark colored and compact but 

contains crevices filled with red clay which 

give it a pink appearance. 

Mimbres Mountains.-It appears probable 

from the statements of Gordon 4 that the Fusselman limestone is present, at least in places, 

in the Kingston-Hillsville region, but he reports no fossils. The statement that the 

A 

W. 

B . 

0 r,ooo z,ooo FEET . ~-----L---~ 

FIGURE 9.-Sectionsacrossthe San Andres Mountains, Socorro and Dona Ana counties, N.Mex. A, Section across Sheep Mountain at Lava Gap; 

B, section southwest of San Nicolas Spring, in latitude 32° 35' N.; gr, ·granite; b, Bliss sandstone; e, El Paso limestone; m, Montoya lime 

stone; f, Fusselman limestone; p, Percha shale; lv, Lake Valley limestone; mg, limestone of the Magdalena group. 

Lake Valley.-It was found that the limestones underlying the Percha shale in the Lake 

Valley area (see fig. 10, p. 44) include 200 feet 

or more of the Fusselman limestone, which 

contains many distinctive fossils. At the 

base, overlying beds that are probably Montoya, there is an 80-foot bed of massive limestone which weathers to light tint, and which 

yielded no fossils but is tentatively regarded 

as the Fusselman, as in other regions. Next 

above are 40 feet of cherty beds, somewhat 

like th~ Montoya in character but carrying 

distinctive fossils. These beds grade upward 

into 80 feet or more of massive limestone of 

light color, constituting the summit of Quartzite Ridge for some distance and extending 

down its east slope to the Percha shale in the 

valley. In cherty layers on this slope dis1 Am. Jour. Sci., 4th ser ., vol. 26, p. 185, 1908. 

"footwall lime" at Kingston and Tierra Blanca 

is similar to the ore-bearing sandstone in the 

Cooks mining district is highly suggestive in 

this connection. 

San Andres Mountains.-The Fusselman 

limestone is a conspicuous feature in the limestone succession along the east front of the 

San Andres Mountains from a point near Organ, 

where it is cut off by igneous rocks, to a point 

2 or 3 miles north of Sulphur Gap, where it 

thins out. Some of its relations are shown in 

figures 9 and 11. The thickness ranges from 

220 feet in the southern part of the range to 

120 feet in the middle part and at Sulphur Gap, 

and there is rapid thinning toward its north2 U. S. Gaol. Survey Prof. Paper 68, pp. 227, 277, 1910. 

a Keyes, C. R., Genesis ofthe Lake Valley, New Mexico, siJver deposits: 

Am. Inst. Min. Eng. Trans., vol. 39, p. 146, 1909. 

'U. S. Gaol. Survey Prof. Paper 68, p. 227, 1910. 
COMPARISON OF PALEOZOIC SECTIONS IN SOUTHERN NEW MEXICO. 43 

ern termination. The formation comprises 

two members-an upper bed of hard darkcolored massive limestone, marked by a cliff 

at most places, and a lower member of finegrained limestone, most of which weathers 

nearly white. The upper member contains 

distinctive fossils, but the lower one has 

yielded no fossils and is arbitrarily placed in 

the formation because of its distinctness from 

the underlying cherty beds, which are characteristic of the upper part of the Montoya. 

The massive bed gives rise to a shelf at the 

base of the slope of the overlying Percha 

shale. Its thickness is 80 feet in the southern part of the range, but it gradually thins 

northward to 40 feet in Lostman Canyon, 30 

feet in Hembrillo Canyon (see Pl. XV, A), and 

25 feet in Sulphur Gap. The lower limestone 

is 140 feet thick in the south end of the range, 

but it thins somewhat north of San Andres 

Peak. It is nearly 100 feet thick in Sulphur 

Gap but thins out and disappears in slopes 

north of the gap. In places some of its beds 

are soft and earthy, as in Lostman Canyon, 

but most of it is a fine-grained, compact darkgray rock that weathers to very light gray or 

nearly white so that it is conspicuous in all 

outcrops. 

Sacramento Mountains.--:- The Fusselman 

limestone makes a prominent ledge along the 

east front of the Sacramento Mountains from 

Alamo Canyon to a point near Agua Chiquita 

Canyon. Its disappearance to the north and 

south is due to the downward pitch of the anticline that brings it to the surface. (See fig. 14, 

p. 51.) The thickness ranges from 105 to 130 

feet; the maximum is reached in Alamo Canyon. 

(See Pl. XIX, A, p. 37 .) As in the San Andres 

Mountains and other uplifts, the formation comprises two members-an upper one, about 50 

feet thick, of hard dark limestone carrying distinctive fossils, and a lower one of compact, 

fine-grained gray limestone that weathers 

nearly white, and is 60 feet thick in Dog Canyon 

and 85 feet thick in Alamo Canyon. The lower 

member yielded no fossils, but is arbitrarily included in the formation because of its unlikeness to underlying distinctively cherty beds at 

the top of the Montoya limestone. It constitutes a steep light-colored slope below the dark 

cliff of limestone of the upper member of the 

formation. This cliff is well shown in Plate 

XIX, A. 

Fossils and correlation.-In general fossils 

are rare in the Fusselman limestone, but at 

some localities a few of the beds yield abundant 

remains. The most common and characteristic form is a Pentamerus, but many corals 

occur at some places. 

The fossils found by Richardson 1 in the 

Franklin Mountains included Amplexus, Favosites, and numerous casts of Pentamerus, all 

indicative of Niagara age. The same Pentamerus is abundant in the upper beds near 

Cooks and Silver City.· On the south side of 

Mine Hill, in the Victorio Mountains, numerous 

corals were collected, including Heliolites megastoma, Favosites cf. F. venustus, Oyathophyllum ef. 0. radicula, Halysites catenulatus (large 

and small varieties), and Syringopora sp., also 

an orthoid suggesting Rhipidomella hybrida. 

These were determined by E. 0. Ulrich, who 

regards them as probably late Niagara and 

similar to a coral fauna found by Kindle in the 

Laketown dolomite of northeastern Utah. 

From the upper ledge of the limestone in the 

San Andres Mountains 1l miles southwest of 

San Nicolas Spring, or about 22 miles 'northeast of Las Cruces, the writer collected the 

following forms, determined by Edwin Kirk: 

Pentamerus sp., Oyathophyllum sp., Heviolites 

sp., and Hormotoma sp.-a distinctive Fusselman fauna. 

The Pentamerus was observed at many other 

localities in the San Andres Mountains as far 

north as Sulphur Gap and also in the east front 

of the Sacramento Mountains. 

Fossils were collected at three horizons in the 

Fusselman limestone at Lake Valley, all from 

beds above the 80-foot member that weathers to 

a light color. Cherty layers not far above this 

member yielded Monomerellan. sp. and Zaphrentis sp. In cherty layers about 100 feet higher 

Monomerella was very abundant, and near the 

top, about 30 feet below the base of the Percha 

shale, were collected Zaphrentis sp., Amplexus 

sp., and a variety of Pentamerus oblongus that 

is characteristic of the upper beds in other 

regwns. 

1 U.S. Geol. Survey Geol. Atlas, El Paso folio (No. 166), 1909. 
44 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

DEVONIAN SYSTEM. 

PERCHA SHALE. 

General relations.-Only a small part of 

Devonian time is now represented in New 

Mexico. The deposits consist of the Percha 

shale, in which Gordon and Graton 1 found 

Dev.onian fossils in the Lake Valley and Kingston regions. The formation is named . from 

Percha Creek, near Kingston . . It overlies the 

Fusselman limestone, but in places It is ab~ent 

and the Fusselman is overlain by beds of Carboniferous age. N otwithstandi~g the long interval between the Fusselman and Percha 

epochs, the beds show no noticeable difference 

in attitude, but there is an abrupt change from 

massive limestone to black shale. 

Lake Valley and Hillsdale region.-In the 

Lake Valley mining region the Peroha shale 

appears in a narrow outcrop that extends for 

about 3 miles along a valley just west of the 

ndge of Lake Valley limestone, as shown in 

Horizontal scale 800 . 0 800 FEEi 

part fine grained, with no fossils. The upper 

member consists of 10 feet of bluish thinbedded limestone made up largely of chert in 

elongated nodules and containing no fossils. 

According to Keyes, "it contrasts strikingly 

with the massive compact blue limestone lying 

immediately above." 

In the Kingston-Hillsboro region portions of 

the basal beds are altered to a fine-grained red 

to black siliceous rock of a j aspery character, 

somewhat brecciated and seamed with quartz. 

The quartz seams are believed to have been 

formed by heated siliceous water. 

Oooks Range.-In Luna County the Percha 

shale appears in Cooks Range and Fluorite 

Ridge, where it has a thickness of 175 feet. 

The rock is a uniform black shale of moderate 

hardness separating into thin brittle layers. 

It crops out extensively along the limestone 

slopes on both sides of the range northwest of 

Cooks, where it immediately overlies the oreVertical scale 0 400 800FEET 

FJGURE 10.-Section through the Lake Valley mining district, Sierra County, N.Mex. e, El Paso limestone; m, Montoya limestone, with 

sandstone (ss) at base; f, Fusselman limestone, with white limestone (w) at base; p, Percha shale, including lower member (d) and upper 

member (c); n, nodular limestone; lv, Lake Valley limestone, including ore horizon, or · "footwa lllime" (o), shale and thin limestone (s); 

limestones, upper beds cherty (b), and andesite and rhyolite (a). 

figure 10~ It is mentioned in several published reports regarding the relations of the 

ore~ of the district. Two members were recognized by Gordon 1

-an upper grayish-yellow to 

blue shale 60 feet thick (c in fig. 10) and a 

black fissile shale 100 feet thick (d in fig. 10). 

Neither of these is fossiliferous at Lake Valley, 

but beds near the top of the upper member 

yielded an extensive fauna at Hillsboro and 

Kingston. Keyes 2 stated that the overlying 

nodular limestone, 50 feet thick, at Lake Valley is also Devonian and' proposed for it the 

name Barenda. He described it as consisting 

of three distinct members. The lowest one is 

a massive, compact gray limestone, like 

lithographic stone, 10 feet thick, weathering 

rusty brown and carrying ,a "typical late 

Devonian fauna." The medial member, 30 

feet thick, is gray thin-bedded limestone, 1n 

1 Am. Jour. Sci., 4th ser., vol. 21, p. 394, 1904. 

ll Am. Inst. Min. Eng. Trans., vol. 39, p. 147, 1909. 

bearing Fusselman limestone. It is absent in 

the Victorio Mountains. 

Florida Mountains.-In the southern part 

of the Florida Mountains there is a dark shale 

which closely resembles the Percha but which 

appears to be in the Gym limestone succession. 

though this apparent relation may be due to 

overlap or faulting. 

Silver Oity.-The Percha shale crops out in 

several small areas about Silver City, and it 

also occurs in the vicinity of Georgetown and 

Hanover, a few miles to the east. The maximum thickness in this area is 500 feet, but in 

places the amount is much less. 

Caballos Mountains.-Gordon3 suggested that 

the black shale in the Caballos Mountains 

is the Percha, but he reported no fossils. 

In places, especially to the north, the shale is 

absent and the Pennsylvanian limestone lies on 

.the Montoya or higher limestones. According 

a U. S. Geol. Survey Prof. Paper 68, p. 226, 1910. 
COMPAR.ISON OF PALEOZOIC SECTIONS TN SOUTHERN NEW MEXICO. 

to Lee, 1 in the section 8 miles south of Shandon 1 in blue shales near the upper part of the upper 

300 feet of black shale intervenes between member at Kingston and at a locality 2 miles 

"late Ordovician" cherty limestone and lime- east of Hillsboro. The following were identistones of Carboniferous age. fied by Girty and Kindle: 4 

Franklin Mountains.-As Richardson 2 found 

Carboniferous and Silurian fossils very near 

· together in the Franklin Mountains, it appears 

that the Devonian is not represented in the 

succession of limestones in that range. . 

Sacramento Mountains.-The Devonian is 

probably represented in the section exposed 

along the west front of the Sacramento Mountains southeast of Alamogordo, in the lower 

part of the shale that lies on the Fusselman 

limestones, but the fossils found were not 

sufficiently wel.l preserved to be determined 

specifically. 

Zaphrentis sp. 

Spirorbis sp. 

Leptaena rhomboidalis. 

Productella coloradensis var. plicatus. 

Productella spinigera. 

Productella hlllsboroensis. 

Schizophorla striatula var. australis. 

Camarotoechia (Plethorhyncha) endlichi. 

Camarotoechia contracta. 

Eunella sp. 

Athyris coloradensis. 

Pugnax pugnus. 

Spirifer whitneyi. 

Spirifer whitneyi var. animasensis. 

S pirifer nota b ili s; 

Southerr. San Andres Deadman and Hembr; l!o Sulphur Gap Cottonwood Rhodes Salinas Peak ridges Canyon,· Lostma!' canyons Canyon Canyon Canyon to Hays Gap 

CARBONIFI;ROUS 

DEVONIAN 

SfLURlAN 

ORDOVICIAN 

Magdalena group (lower part o~ly) 

h~is'ft~~y 

E.l Paso li'!'estone 

CAMBRIAN Bliss sahdstone 

f'R.E· CAMBRIAN Granite and schist Vertical scale o soo 1.000 Feet 

m, Magdalena fossils 

lv, Lake Valley f'ossils 

FIGURE 11.-Columnar sections showing stratigraphic variations in lower Paieozoic rocks in the San Andres M:Quntains, Dona Ana and 

Socorro counties, N. M:ex. 

San Andres Mountains.-Shale with Upper 

Devonian fossils extends along the San Andres 

Mountains from a point 2 miles northeast of 

Organ, where igneous intrusions cut off the 

succession, nearly to Mockingbird Gap. Its 

thickness is 50 feet or more, and it crops out 

in a slope between the prominent ledge of 

massive limestone above and a shelf or cliff 

of Fusselman or Montoya limestone below. 

The basal beds are black shale, above which are 

layers of slabby and nodular limestone separated by gray shale. Possibly in places the 

uppermost layers of shale are Carboniferous. 

The fossils found were mostly in the medial 

beds. Some of the relations are shown in 

figures 9 and 11 and Plates XV (p. 33) and 

XVIII (p. 36). . 

Fossils.-The Devonian fossils reported by 

Gordon and Graton 3 were found in abundance 

1 Am. Jour. Sci., 4th ser., vol. 26, p. 182, 1908. 

2 U.S. Geol.Survey Geol. Atlas, El Paso folio (No.166), p. 4, 1909. 

a Am. Jour. Sci., 4th ser., vol. 21, p. 394, 1904. 

Syringospira prima. 

Reticularia splnosa. 

Merlstella barrisi. 

Fossils found by Paige in the Percha shale at 

Silver City are as follows: 

Schizophoria striatula var. australis. 

Productella coloradensis. 

Productella spinigera. 

Productella laminatus. 

Camarotoechia contracta? 

Camarotoechia (Plethorhyncha) endlichi. 

Pugnax pugnus. 

Spirifer notabilis. 

Spirifer whitneyi. 

Reticularia spinosa. 

Athyris coloradensis. 

A viculipecten n. sp. 

Bellerophon sp. 

Euomphalus eurekensis? 

Corals and bryozoans. 

The following fossils were found in the 

Percha shale in 1915 a mile south of Capitol 

4 See Kindle, E. M., The Devonian fauna of the Ouray limestone: 

U.S. Geol. Survey Bull. 391, 1909. 
46 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

Peak, in the northern part of the San Andres 

Mountains. They were identified by Edwin 

Kirk: 

Tropidoleptus carinatus var. 

Alveolltes sp. 

Spirifer n. sp. 

Stropheodonta near S. arcuata Hall. 

Productella hallanus. 

Atrypa reticularis. 

Atrypa hystrix. 

Schizophoria striatula var. australis? 

Dlaphosostoma sp. 

On the . north slope of Sheep Mountain, in 

Lava Gap, a mile farther south, were obtained 

Zaphrentis, Atrypa reticularis, Oyrtia n. sp., 

Productella hallanus, and Stropheodonta near 

S. arcuata. In Sulphur Gap, which is not far 

north of the latitude of Alamagordo, the following forms were collected from medial beds: 

Atrypa hystrix. 

Atrypa reticularis. 

Schizo phoria striatula var. australis. 

Pugnax pugnus. 

Camarotoechia contracta? 

Chonetes sp. 

Stropheodonta n. sp. 

Spirifer whitneyi var. animasensis. 

Spirifer sp. 

In a canyon 3 miles south of San Andres 

Peak were found Rhipidomella sp., Spirijer 

sp., and Chonetes sp. In Cottonwood Canyon 

the shale yielded Spirijer whitneyi. 

In nodular beds in the middle of the formation in San Andres Canyon were found the 

following: 

Zaphrentis ·sp. 

Fenestella sp. . 

Productella d. Productellacoloradoenslsvar. plicata. 

Ambocoelia sp. 

Schlzophoria striatula var. australis. 

Leiorhynchus? sp. 

Spirifer cf. Spirifer utahensis. 

Retlcularia undifera var. 

Phacops sp. 

At the same horizon in Hembrillo Canyon 

were obtained Fenestella, Atrypa reticularis, 

Pugnax pugnus, Oyrtia sp., Stropheodonta near 

S. arcuata, Gypidula sp., and Productella sp. 

A few fragmentary fossils were collected from . 

black shale a few feet above the Fusselman 

ledge near Dog Canyon, in the west front of 

the Sacramento Mountains, but they could not 

be determined. Mr. Kirk recognized one of 

the brachiopods as Jferistella or some closely 

allied genP", almost certainly Devonian. 

Age and correlation.-The fossils from the 

Percha shale are regarded by Mr. Kirk as indicating that the formation is late Devonian, 

equivalent to the lower part of the Ouray 

limestone and the upper part of the Martin 

limestone (Upper Devonian) of the Bisbee 

region, Ariz., and the upper 2,000 feet of 

Nevada limestone of the Eureka district, 

Nev. As the lower beds of the Percha shale 

in the type locality have not yielded fossils, 

the formation may represent a somewhat 

greater range than is indicated by the collections recorded. The beds in the San Andres 

Mountains appear to carry a smaller number 

of the typical lower Ouray forms than are 

present in Lake Valley, and more of the forms 

characteristic of the Martin limestone and 

Nevada limestone. However, all the New 

· Mexico collections are too fragmentary to per-

;mit precise correlation. 

CARBONIFEROUS SYSTEM. 

GENERAL FEATURES. 

In southern New Mexico rocks of Carboniferous age comprise representatives of the 

earlier part of Mississippian and of a large 

part of Pennsylvanian and Permian time, the 

later Mississippian being unrepresented there; 

as in most · other portions of the West. In the 

Lake ·Valley region and to the south the formation of lower Mississippian age is the Lake 

Valley limestone, which appears in most of 

the uplifts between latitudes 32° 20' and 34°. 

The rocks of supposed Mississippian age in the 

Magdalena region are known as the Kelly 

limestone. The beds of the Pennsylvanian 

and Permian series occur throughout the area 

and in the adjoining States. They comprise 

a great thickness of limestone, which to the 

northeast is accompanied by the red sandstone 

and shale of the Abo sandstone and many 

thick deposits. of gypsum. 

In Luna County the formations of the Pennsylvanian and Mississippian series are separated 

by a hiatus of considerable amount, and there 

is an overlap of the higher limestone toward 

the south. Thus, in the Florida, Victorio, 

and Franklin mountains the later Carboniferous rocks lie directly on the Silurian limestone, 

and the Mississippian and earlier PenJsylvanian 

(Magdalena group) appear to be absent. The 

Manzano group, or later Carboniferous, is 

represented by a thick limestone formation, 
COMPARISON OF PALEOZOIC SECTIONS IN SOUTHER.N NEW MEXICO. 47 

the Gym limestone. A still younger formation, separated as the Lobo and tentatively 

assigned to the Triassic, may possibly represent 

·the upper part of the Manzano. 

A comparison of the Carboniferous rocks of 

southern New Mexico with those of Arizona 

shows close similarity. The Lake Valley limestone has the same fauna as the Modoc limestone at Clifton, 1 180 feet thick, and the Escabrosa limestone of the Bisbee region, 2 700 feet 

thick. The Magdalena group is represented in 

whole or part by the Tule Spring limestone of 

Clifton, 500 feet thick, and by part of the Naco 

limestone of the Bisbee region. The Naco, 

which is 3,000 feet or more thick, appears to 

include in its upper,part a thick representative 

·of the Hueco limestone of western Texas. 

Farther west and north in Arizona, especially 

in the Grand Canyon region, the Redwalllimestone, 1,000 feet or more thick, comprises representatives of both the Pennsylvanian and the 

earlier Mississippian, the Pennsylvanian beds 

being equivalent to the Magdalena group. The 

overlying red beds of the Supai formation, 

1,200 feet thick, probably correspond to the 

Abo sandstone (red sandstone), 700 to 1,000 

feet thick, at the base of. the Manzano group. 

The overlying Coconino sandstone and Kaibab 

limestone, the latter in places containing gypsum deposits, are probably equivalent to the 

great succession of sandstone, gypsum, and 

limestone that constitute the upper part of the 

Manzano group in New Mexico. G. H. Girty 

regards the fauna of the upper limestone of the 

Manzano group as Closely similar to that of the 

Kaibab limestone. Representatives of the 

Supai and Abo red beds are lacking to the 

south, notably in southern New Mexico, in 

southwestern Texas, and in the Naco limestone 

succession of the Bisbee region. 

LOWER MISSISSIPPIAN LIMESTONES. 

Lake Valley region.-The Lake Valley limestone received its name from the Lake Valley 

:.:nining district, where it crops out in an area 

about 3 miles long and half a mile wide. In 

that district it consists of about 200 feet of 

I Lindgren, Waldemar, U.S. Geol. Survey Geol. Atlas, Clifton folio 

(No. 129), 1905. 2 Ransome, F. L., U. S. Geol. Survey Geol. Atlas, Bisbee folio (N o.112), 

1904. 

limestone underlain by the Percha shale and 

at the top eroded and in part overlain by Tertiary igneous rocks. (See fig. 10, p. 44.) Distinctive lower Carboniferous (Mississippian) 

fossils were found in these limestones by Cope 3 

in 1881 and by others at intervals later, notably 

by Springer/ who published a detailed list of 

many forms, including an extensive crinoid 

fauna closely similar to the lower ·Burlington 

of Iowa. The section given by Springer is as 

follows: 

Section of Lake Valley limestone at Lake Valley mining 

camp, N. Mex. 

Feet. 

9. Cherty limestone, with irregular flinty masses, in 

places light colored and full of crinoids ... _. __ .. 30 

8. Limestone, heavy bedded, pink to drab; marly 

partings; many crinoids, corals, and other fossils. . 40 

7. Limestone, thin bedded, bluish, mostly shaly; 

many crinoids, corals, bryozoans, and other fossils . . ............................ ___ . _ _ _ _ _ _ _ _ 20 

6. Limestone, hard, granular, sandy, pinkish to bluish .......................... __ ... ____ .______ 6 

5. Shale, light yellow, with flinty nodules. ___ ._.... 15 

4. Limestone, irony, coarse, irregularly bedded, with 

marly partings; corals and crinoid fragments .. __ 30 

3. Sandstones, dark brown, heavy bedded and hard below, shaly above ............ __ ...... __ .. ____ ._ 12 

2. Shale, light yellowish, with irregular flinty masses; 

no fossils._ .................... ____ ._. ___ ...... 8 

1. Slope covered by debris. 

Beds 7 and 8 yielded most of the fossils. 

The beds below No. 7 Springer referred to the 

Kinderhook group. No fossils were reported 

from bed 3. A section given by Gordon, 5 who 

visited the locality in 1905 is as follows: 

Section of Lake Valley limestone at Lake Valley, N. Mex. 

9. Capping of andesite. Feet. 

8. Limestone, coarse, subcrystalline, yellowish white; 

moderately thick beds, some cherty; many crinoids and other fossils; top eroded. __ . __ .. _.____ 60 

7. Shale, blue; includes thin bluish limestone beds; 

many fossils but fewer crinoids than No.8 .... _. 75 

6. Limestone, grayish blue, hard, more or less siliceous, called "blue limestone" in the mines. Local breccia of flint at top. At base 5-foot bed of 

coarse crystalline yellowish-white limestone.... 25 

5. Limestone, compact, grayish, filled with nodular 

chert; partings mostly thick................... 50 

Percha shale. 

scope, E. D., Geology of the Lake Valley mining district: Am. Naturalist, vol. 15, pp. 831-832, 1881. 

4 Springer, Frank, on the occurrence of the Lower Burlington limestone 

in New Mexico: Am. Jour. Sci., 3d ser., vol. 27, pp. 97-103, 1884. 

6 Gordon, C. H., Mississippian formations in the Rio Grande valley, 

N.Mex.: Am. Jour. Sci., 4thser., vol. 24, pp. !:)8--64,1907. 
48 SHOR.TER CONTRIBUTIONS TO GENERAlt GEOLOGY, 191'7. 

No. 5 (n, fig. 10) is the nodular limestone of 

Clark,1 who described the region in considerable 

detail. Keyes, 2 however, placed this m.ember 

in the Devonian and called it the Barenda 

limestone. 

Cooks Range.-In Luna County the Lake 

Valley limestone occurs only in Cooks Range, 

where its thickness is between 600 and 700 

feet. It consists mainly of light-gray, massive 

to slabby limestone, with several intercalated 

members of shale, partly limy. The limestone 

members crop out mostly as cliffs 80 to 100 feet 

high, separated by shaly slopes. The basal 

member consists of 150 feet of bluish-gray limestone, with some chert in its lower part. The 

upper member contains some thick bodies of 

white chert and cherty limestone. A small 

body of Lake Valley limestone lies on the Percha 

shale in Fluorite Ridge, at the south end of 

Cooks Range, near Cooks Peak. It is cut by 

0 

some beds, and the lower ones yield many Mississippian forms. 

Mimbres Mountains.-Gordon 4 states that 

the Lake Valley limestone crops out at many· 

points along the east side of the Mimbres Mountains, and he gives the section reproduced here 

as figure 12, showing its relations in that region. At Kingston the formation consists of 

thick-bedded blue limestones with nodular 

cherty beds and shaly thin-bedded limestone, 

100 to 125 feet in all. Many distinctive fossils 

occur in it. 

Caballos Mountains.-It is not unlikely 

that some Lake Valley limestone is included in 

·the great section on the west front of the Caballos Mountains, but no data are available on 

this point. 

Magdalena Mountains.-The Kelly limestone, or so-called "Graphic Kelly" limestone, 

the ore-bearing formation in the silver-lf!ad 

E 

2 MILES ~~~---~-~ 

FIGURE 12.-Section from the Mimbres Mountains eastward through Kingston and Hillsboro, N. Mex. (After Gordon.) gr, Granite; b, Bliss 

sandstone; e-f, Mimbres limestone [El Paso, Montoya, and Fusselman]; p, Percha shale; lv, Lake Valley limestone; mg, Magdalena group; 

m, Manzano group; pg, Palomas gravel; bs, basalt sheet; a, andesite; ry, rhyolite; d, dike. 

the great porphyry intrusion and interrupted 

by several faults. Fossils are abundant in the 

limestone in this locality. 

Silver City region.-In the Silver City region 

the two divisions of the Carboniferous are 

grouped together by Paige 3 as the Fierro limestone. The rocks are limestones, ranging in 

color from light gray to dark blue or purplish. 

West of Silver City the upper half is chiefly 

light gray or light blue and the lower part 

darker blue. All but the upper 100 feet is 

cherty, and near the base there is some red chert. 

Some thin, more or less shaly beds are included. 

The Fierro limestone varies in thickness because of the unconformity at its top, and doubtless also between its two division~, but the 

maximum thickness is about 800 feet. It is 

widely distributed, constituting much of the 

range northwest of Silver City, part of Lone 

Mountain, and areas near Fort Bayard and 

north of Santa Rita. Fossils· are abundant in 

IC'lark, Ellis, The silver mines of Lake Valley, N.Mex.: Am. Inst. 

Min. Eng. Trans., vol. 24, pp. 138-169, pl., 1884. 

SAm. Inst. Min. Eng. Trans., vol. 39, p. 147, 1909. 

a U. S. Geol. Survey Geol. Atlas, Silver City folio (No. 199), p. 5, 1916. 

mines at Kelly, is supposed to be of Mississippian age, Herrick 5 and Keyes 6 having reported 

that crinoids were found in it. This limestone 

is white and crystalline, and occurs in thick beds, 

about 125 feet in all, lying on pre-Cambrian 

schist and granite. (See Pl. XIX, B.) Near 

the middle is a 5-foot layer of dark-blue noncrystalline rock, weathering yellowish drab, 

which the miners call "Silver Pipe limestone." 

Keyes 6 gives the following section of the 

limestones in the Magdalena Mountains, including the Kelly limestone, in which Mississippian crinoids were obtained: 

Section of limestone in Magdalena Mountains. 

Feet. 

Limestone, blue, heavy bedded, with thick shale 

partings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300 

Shale, sandy, greenish............................ 200 

Sandstone, greenish, micaceous, soft.............. 50 

Sandstone, quartzite, pebbly (base of Magdalena 

group)........................................ 60 

4 U. S. Geol. Survey Prof. Paper 68, p. 229, 1910. 

o Herrick, C. L., Laws of formation of New Mexico mountain ranges: 

Am. Geologist, vol. 33, p. 310, 1904. 

6 Keyes, C. R., Northward extension of the Lake Valley limestone: 

Iowa Acad. Sci. Proc., vol. 12, pp. 169-171, 1904. 
COMPARISON OF PALEOZOIC SECTIONS IN SOUTHER.N NEW MEXICO. 49 

Shale, dark, siliceous (Mississippian) ............ . 

Limestone, gray, crinoidal (Mississippian) __ ... __ .. 

Limestone, heavy bedded, crinoidal (''uppervein ") 

Limestone, blue, impure,· fine grained, siliceous 

Feet. 

50 

45 

30 

Mississippian series in the west front of the 

Sacramento Mountains but gave but little information as to the conditions of occurrence. 

The bed was stated to be 560 feet above the 

(''Silver Pipe lime") ........................... . 

Limestone, gray, subcrystalline (contact vein) .... . 

8 base of the section in Dog Canyon (see Pl. 

On schists, granite, greenstone, etc. -

60 XIX, A), and the thickness of the "Burlington 

limestone," as Herrick termed it, is 250 feet. 

In 1908, G. H. Girty examined a section east. of 

Alamogordo, in which 1,500 feet of limestone 

and shale containing Pennsylvanian fossils, 

were found to be underlain by 150 feet of limestone containing Mississippian forms. Some of 

the same species were .collected in Alamo Canyon, a few miles farther south, by G. B. Richardson, and also in 1915 by the writer. An 

unpublished section, kindly furnished by Mr. 

Girty, is as follows: 

San Andres Mountains.-The Lake Valley 

limestone occurs in an area of considerable 

extent in the San Andres Mountains, but it is 

not thick and may be discontinuous. In the 

central part of the range a heavy bed of limestone overlying the Percha shale yielded lower 

Mississippian (Lake Valley) fossils at several 

localities, notably in San Andres Canyon and 

on the slopes 3 miles south of San Andres Peak, 

and also at a locality, shown in figure 9 (p. 42), 

west of San Nicolas Spring, or about 16 miles 

northeast of Las Cruces. The greatest thickness observed was in San Andres Canyon and 

northward for 10 or 12 miles, where the amount 

may be 100 feet or more. · The principal bed 

that yielded Lake Valley fossils is a massive 

limestone, cherty in its upper part; but some 

overlying softer beds and a higher massive bed 

may possibly be included in the formation. 

In San Andres Canyon 'the higher massive bed 

is capped by 28 feet of hard gray sandstone, 

immediately above which is shaly limestone 

containing Magdalena fossils. In Hembrillo 

Canyon the only member present is the first 

massive bed that caps the Percha shale, for the 

strata next above carry Pennsylvanian fossils. 

This bed extends northward past Salinas Peak 

to and beyond Hays Gap, where, however, no 

fossils were found in it. In Sulphur Canyon 

it is 60 feet thick and is capped by 30 feet of a 

peculiar sandstone, including considerable conglomerate of large pebbles and fragments of 

white chert. This material is presumably basal 

Magdalena. Some of it appears also in Lostman Canyon. In Deadman Canyon the massive limestone bed above the Percha shale is 80 

feet thick and grades upward in to 50 feet of 

limestone with cherty layers. In Rhodes Canyon the ledge is only 25 feet thick, and in Lava 

Gap it is 30 feet thick. The outcrop at the latter place is shown in Plate XVIII, B. 

Sacramento .llfountains.-In 1900 C. L. Herrick 1 announced the discovery of fossils of the 

1 Herrick, C. L., Univ. New Mexico Bull., vol. 2, No.3, p. 8. The 

geology of the white sands of New Mexico: Joirr. Geology, vol. 8, pp. 

112-128, 1900. 

Section of Carboniferous racks in ridge N. 63° E. of Alamogordo, N. Mex. 

Feet. 

43 Massive limestone. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50± 

42. Thinner beds and concealed .................. 100± 

41. Dark limesto1le- ........ __ ............. c...... 50± 

40. Concealed. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 

39. Dark limestone............ .. ................. 3 

38. Concealed ................................. ~ . . 50 

37. Soft greenish gritty sandstone................. 10 

36. Concealed; debris, limestone and thin greenish 

sandstone .................................. 100 

35. Dark massive limestone, weathering brown..... 25 

34. Concealed.................................... 20 

33. Dark limestone............................... 5 

32. Sandy shale, partly concealed................. 10 

31. Earthy limestone (fossils) ..................... : 4 

30. Dark shale above (20 feet), concealed below.... 50 

29 . Arg.illaceous and calcareous shale (fossils).... . . . 10 

28. Dark siliceous limestone....................... 10 

27. Greenish sandy shale............. . . . . . . . . . . . . . 15 

26. Greenish-brown gritty sandstone............... 10 

25. Shaly materiaL............ . . . . . . . . . . . . . . . . . . . 5 

24. Thin dark siliceous limestone.................. 10 

· 23. Concealed; probably thin impure limestone.... 15 

22. Massive dark limestone........................ 10 

21. Concealed...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 

20. Siliceous limestone below, concealed in middle, 

purer and fossiliferous limestone above....... 20 

19. Greenish gritty sandstone, thin bedded below, 

massive in middle, thinner above.... . . . . . . . 60 

18. Partly concealed; upper part with thin black 

limestone, weathering bluish and yellowish.. 50 

17. Lower 30 feet probably thin gritty sandstone; 

upper 20 feet massive; some layers calcareous, 

with quartz pebbles and fossils.............. 50 

16. Gritty sandstone, calcareous below and fossiliferous ............... : . . . . . . . . . . . . . . . . . . . . . . 10 

15. Dark-brown limestone, somewhat shaly, many 

fossils ........... ·. . . . . . . . . . . . . . . . . . . . . . . . . . 10 

14. Poorly exposed; probably thin dark siliceous 

limestone, weathering brown, poor fossils .... 100± 
50 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

Feet. 

13. Black llmestone, siliceous, weathering brown... 3 

12. Poorly exposed; probably thin impure limestone and a few ledges of dark cherty limestone; poor fossils.......... . . . . . . . . . . . . . . . . . 50 

11. Light-colored sandstone and fine conglomerate; 

poorly exposed. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 ± 

10. Shale with calcareous layers; fossils. ........... 30 

9. Dark impure limestone....................... 15 

8. Unexposed; probably t.h.in sandstone and then 

impure limestone; Productus cora and P. 

semire(iculatus in debris . . . . . ... . . . . . . . . . . . . . 100 

7. Whitish and rusty gritty sandstone, and fine 

conglomerate, not well exposed; perhaps as 

muchas .................................... 300 

6. Light-colored crinoidal limestone; some very 

soft and weathering to graveL..... . . . . . . . . . . 75 

5. Dark siliceous limestone with chert in bands... 30 

4. Massive, rather soft calcareous shale; big crinoid stems and Schizo phoria... . ............... 5 

E. 

occur on the south side of the Sierra Ladrones, 

Socorro County, where in 1905 W. T. Lee 1 

obtained distinctive Mississippian fossils. (See 

list on p. 52.) The locality was in the canyon 

of Rio Salado, about one-eighth of a mile from 

the granite ledges and therefore very near the 

base of the sedimentary succession. Not far 

above are limestones with fossils of Pennsylvanian age, and in 1913 the writer found Pennsylvanian fossils within 3 or 4 feet of the granite on the northwest side of the mountain. 

Evidently the Salado Canyon exposure is 

either an outlying lens of the Mississippian 

limestone or an extension northward from 

Magdalena Mountain. The Mississippian is 

not present east of Socorro and in the Manzano, Sandia, Zuni, Nacimiento, and Rocky 

w. 

FIGURE 13.-Section of the west front of the Sacramento Mountains, 12 miles southeast of Alamogordo, N. Mex. gr, Granite; b, sandstone 

(Bliss?); e, El Paso limestone; m, Montoya limestone (dark massive limestone, overlain by cherty limestone); w, limestone, white when 

weathered (Fusselman?); f, Fusselman limestone; mf, shaly limestone, with Mississippian fossils. 

3. Dark limestone and thin shale interbedded; 

limestone with '' Caudagalli "...... . . . . . . . . . . 20 

2. Same as No.1 but more massive................ 15 

1. Dark bluish-gray calcareous shale, thin bedded 

and rather.massive; base not seen. 

Fossils of Mississippian age were obtained 

from bed 6 (see list on p. 52), as well as in the 

lower beds, and this member is tentatively 

regarded as the top of the Mississippian, 

although possibly bed 7 should also be included. Beds 1 and 2 extend down to the edge 

of the valley fill. The strata containing Mississippian fossils extend all along the west front of 

the range, from a point opposite Alamogordo 

nearly to Grapevine Canyon. The most abundantly fossiliferous beds are in the 100-foot 

member of shales and slabby limestone lying 

between a massive ledge of coarse-grained limestone and the top of the cliff of Fusselman 

limestone. 

The relations of these Mississippian beds are 

shown in figures 13 and 14, the latter showing 

the long arch extending along the mountain 

front east-sQutheast of Alamogordo. (See also 

Pls. XX and XXI.) 

Sierra Ladrones.-The northernmost known 

rocks of Mississippian age in New Mexico 

mountains, where rocks of the Pennsylvanian 

series lie directly on pre-Cambrian granite. 

Fossils.-ln the type locality at Lake Valley, 

from beds 7 and 8 in the section gi v~n on page 

4 7, were obtained the following fossils. The 

identifications were made by G. H. Girty, 

except those of the crinoids, which were made 

by Frank Springer: 

Cladochonus sp. 

Favosites aff. F. valmeyerensis. 

Zaphrentis sp. 

Amplexus aff. A. fragilis. 

Platycrinus peculiaris. 

Platycrinus parvinodus . . 

Platycrinus pileiformis. 

Periechocrinus wh.itei. 

:M:egistocrinus evansi? 

Dorycrinus unicornis. 

Physetocrinus lobatus. 

Physetocrinus planus. 

Steganocrinus sculptus. 

Fistulipora americana. 

Cheilotrypa? sp. 

Fenestella sp. 

Pinnatopora sp. 

Rhombopora sp. 

1 Gordon, C. H ., Mississippian formations in the Rio Grande valley, 

N.Mex.: Am. Jour. Sci., 4th ser., vol. 24, p. 58, 1907. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XX 

VIEW LOOKING SOUTHEAST ALONG WEST FRONT OF SACRAMENTO MOUNTAINS FROM ALAMOGORDO, OTERO COUNTY, N. MEX. 

A, M outh of Alamo Canyon; 0, canyon with small orchard at its mouth; F, northwest-southeast fault; S, San Andres Canyon; c, [I Paso limestone; m, M ontoya limestone; f, Fusselman limestone; mf, limestone with 

M ississippia n f ossils above which arc Pennsylvanian limestones. 

,. 
U. S. GEOLOGICAL SU~VCY PROFESSIONAL PAPER 108 PLATE XXI 

VIEW ALONG WEST FRONT OF SACRAMENTO MOUNTAINS AT AGUA CHIQUITA CANYON, OTERO COUNTY, N. MEX. 

Looking southeast. m , M on toya limestone ; e, El Paso limestone ; gr, granite. 
DEPARTMENT OF THE INTERIOR 

FRANKLIN K. LANE, Secretary 

UNITED STATES GEOLOGICAL SURVEY 

GEORGE OTIS SMITH, Director 

Professional Paper 108-D 

WASATCH FOSSILS IN SO-CALLED FORT UNION BEDS 

OF THE POWDER RIVER BASIN, WYOMING 

AND THEIR BEARING ON THE STRATIGRAPHY OF THE REGION 

BY 

CARROLL H. WEGEMANN 

Published May 29,1917 · 

Shorter contributions to general geology, 1917 

(Pages 57-60) 

WASHINGTON 

GOVERNMENT PRINTING OFFICE 

1917 
ILLUSTRATIONS. 

PLATE XXII. A, Sandstone bed in Lance formation showing large "concretions"; B, Great Pine Ridge, Wyo., 

formed by outcrop of Fort Union formation ......................................... : .... . 

XXIII. A, Badlands in Wasatch formation at fossil locality near the Davis ranch, Sussex, Wyo.; B, 

Kingsbury conglomerate on Kingsbury Ridge, 8 miles southwest of Buffalo, Wyo ........... . 

FIGURE 16. Map of northeastern Wyoming ..•.................••..•.............•.....•....•..•.••........ 

II 

Page, 

58 

59 

57 
W~SATCH FOSSILS IN SO-CALLED FORT UNION BEDS OF THE POWDER 

RIVER BASIN, WYOMING, AND THEIR BEARING ON THE STRATIG-

. RAPHY OF THE REGION. 

By CARROLL H. WEGEMANN. 

Northeastern Wyomipg is occupied by a 

broad structural basin opening to the north 

and bounded on the ea~t, south, and west by 

three mountain upliftsTthe Black Hills, the 

Laramie Mountains, and the 

Big Horn Mountains. (See 

fig. 16.) Throughout much 

of this basin the suriface 

rocks are of Tertiary! age. 

They contain the pr~cipal 

coal beds of the region and 

have been classified in all the 

more recent Survey reports as 

Fort Union. The true age of 

these rocks and the general 

stratigraphyofthefresh-water 

beds that underlie them are 

the theme of this paper. 

tion, the transition being marked by thin beds 

of coal and carbonaceous shale. Neither at 

the base nor at the top has evidence of unconformity been observed in this region. 

104 

The rocks above the Fox 

Hills sandstone on the southwest side of the basin may 

be separated, on lithologic 

grounds, into three divisions. 

TheLanoofurmation, about ~~~~~~~~~~~~~~~~~~~~~~~~~· 

3,200 feet thick, consisting of 

gray shale and buff finegrained slabby or concretionary sandstone, is at the base. 

It conta-ins a few thin coal 

beds at various horizons in 

the formation, particularly 

near the base and top, but 

they are so thin and the coal 

is so poor as to be· of no commercial value. 

One of the most characteristic features of the 

Lance consists of large round concretionary 

masses that weather from the sandstone beds. 

(See Pl. XXII, A.) These masses resemble 

great boulders, and some of them are as much 

as 10 or 15 feet in diameter. 

At its top the Lance grades almost imperceptibly into the beds of the overlying forma77482°-17 

10 20 30 40 50 60 Mll.ES 

FIGURE 16.-Map of northeastern Wyoming. 

The Lance formation, as a whole, is a unit 

that is not susceptible of division on lithologic 

grounds. The vertebrate remains, however 

(for the most part Triceratops and Trachodon), 

are not distributed through the w:hole formation, but are found only in the lower 2,000 feet. 

The upper 1,200 feet of beds, although identical in appearance with those below, are apparently barren of vertebrate fossils. 

57 
58 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

Above the Lance formation is about 2,000 

feet of very fine grained bluish-white sandstone interbedded with gray shale and with a 

few beds of coarser sandstone, containing 

grains one-eighth of an inch in diameter. 

This formation is distinguished from the underlying Lance by its bluish-white color, the absence of large round concretionary masses, 

and the presence of beds of highly ferruginous 

sandstone only a few inches thick. The iron 

in many of these ferruginous beds appears to 

be of secondary origin, having probably been 

deposited from ground water. Some . of it 

may represent swamp deposits, although this 

is difficult to demonstrate. · 

The formation as a whole is more resistant 

to erosion than the formations above and below it, so that its outcrop around the margin 

of the great basin already described forms a 

prominent escarpment, which is generally timber covered, and to which the writer has referred in several reports as the ''Great Pine 

Ridge." (See Pl. XXII, B.) Fossil leaves, 

that are found in abundance in some of the 

ferruginous beds, have been determined by 

F. H. Knowlton as of Fort Union age, but 

the strata have heretofore been considered as 

comprising only the basal mmnber of that 

formation. 

The bluish-white shale and sandstone of the 

Great Pine Ridge are overlain by about 2,500 

feet of beds that are the principal coal-bearing 

rocks of the upper Powder River valley and 

that have in the past been considered by most 

workers in the region, the writer included, as 

of Fort Union age, constituting the upper division of that formation. (See Pl. XXIII, A.) 

These beds consist mainly of gray shale and. 

fine-grained dirty-white sandstone. They include some beds of coarser sandstone, especially 

in the upper part of the formation, and at the 

bases of these are found in many places thin 

layers of conglomerate. At certain horizons 

there are layers of pink shale and pink sandstone whose color-in the sandstone at leastis variable from place to place. Ferruginous 

layers, so abundant in the underlying formation, are here absent. Distributed through the 

formation at various horizons are beds of sub bituminous coal, which range in thickness from 

a few inches to 50 feet. Some of the beds are 

apparently very lenticular and can be traced for 

only a few miles along their outcrop. Others 

are very persistent and underlie hundreds of 

square miles of territory. 

During the season of 1915 R. W. Howell and 

the writer examined an area of about 2,000 

square miles, extending from northwest Converse County northward ~ong the divide on 

which are situated the Pumpkin Buttes to the 

Powder River valley. In the Pumpkin Buttes 

are exposed the highest beds that are present 

in this general region. About 12 miles west of 

the buttes lies the Great Pine Ridge, and between this ridge and the buttes is the most advantageous locality at which to measure the 

thickness and study the characteristics of the 

overlying formation, the so-called upper division of the Fort Union. To Mr. Howell belongs 

the credit of finding the first tooth of Ooryphodon discovered by the party. The specimen was 

found between the Middle and North buttes 

at about 950 feet below the top of the formation as there exposed. Mr. Howell and the 

writer afterward returned to the place and obtained several other teeth. All came from a 

blue shale underlying a thick sandstone bed; at 

the base of which is one of the small local unconformities characteristic of the formation. 

Later in the season we obtained from Mr. William Black, a rancher, other specimens of Coryphodon teeth, which ~e described as having 

been found at the top of Dome Butte, an outlier 

of North Pumpkin Butte. The sandstone that 

caps this butte is the same as the basal part of 

the thick sandstone bed that caps all the Pumpkin Buttes. Mr. Black gave the locality accurately, and Mr. Howell afterward visited it. 

He did not discover any more teeth but did 

find fragments of bone embedded in sandstone, 

that correspond in texture to that ·in which 

the specimens which we had received were embedded. J. W. Gidley states, with regard to · 

this as well as the former collection, that . the 

teeth belong to Goryphodon molest us, a genus 

knownonlyfrom the Wasatch. Itw<;mldseem, 

therefore, that. these remains afford definite 

evidence for correlating the rocks that form 

the Pumpkin Buttes, or the upper 1,000 feet of 

the formation heretofore called Fort Union, 

with theW asatch. The 1,400 feet of beds from 

the base of the Pumpkin Buttes down to the top 

of the Great Pine Ridge are lithologically similar to the rocks of the buttes themselves, and 

there is every reason, on lithologic grounds, to 

suppose that they belong to the same formation 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XXII 

A . SANDSTONE BED IN LANCE FORMATION, SHOWING LARGE "CONCRETIONS." 

B. GREAT PINE RIDGE, WYO., FORMED BY OUTCROP OF FORT UNION FORMATION. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XXIII 

A. BADLANDS IN WASATCH FORMATION AT FOSSI.L LOCALITY NEAR THE DAVIS RANCH, 

SUSSEX, ·WYO. 

Photograph byT. W. Stanton. 

B. KINGSBURY CONGLOMERATE ON KINGSBURY RIDGE, 8 MILES SOUTHWEST OF 

BUFFALO, WYO. 
WASATCH FOSSILS OF THE POWDER RIVER BASIN, WYO. 59 

as the rocks from which Ooryphodon has been 

obtained. 

In 1910 T. W. Stanton, A. R. Schultz, and 

the writer made a collection of small mammal 

"teeth from a horizon about 700 feet above the 

top of the beds forming the Great Pine Ridge, 

at a place 20 miles west of Pumpkin Buttes. 

(See Pl. XXIII, A.) · Some shale beds in the 

vicinity are pink or red and resemble the Wasatch beds of southwestern Wyoming. The 

writer was directed to this loc!;tlity by Mr. H. W. 

Davis, an old-time rancher of the region, who 

stated that some years before students from 

Amherst, Mass., had made a collection from 

the locality and found the jaw of a fossil horse. 

Concerning this statement Prof. F. B. Loomis, 

of Amherst, has informed the writer that a 

party under his direction made a collection 

near the Davis ranch in 1904 which included 

teeth regarded by him as belonging to Eohippus 

and Ooryphodon. With regard to the 1910 

collection near the Davis ranch, Mr. Gidley has 

very kindly prepared the following statement: 

On a former preliminary examination of the material 

from the vicinity of the Davis ranch, Sussex, Wyo., I was 

led to believe that it indicated Fort Union deposits at that 

locality. My · conclusion was based principally on the 

presence in the collection of a little insectivorous mammal 

represented by a portion of a lower jaw containing two 

teeth. This or a closely related species occurs also in 

the Fort Union beds of Sweet Grass County, Mont., and 

so far as I know has never been found elsewhere. Its 

presence, however, is by no means conclusive-evidence of 

the Fort Union age of these b~ds. For, while this particular animal has not yet been found in other formations, 

there are several forms commonly found in the Fort Union 

(or the Torrejon) which are known to extend beyond the 

limits of this formation and occur in beds recognized as 

lower Wasatch. 

Of the three mammal molars also included in the collection from the Davis ranch, I stated five years ago that 

they represented undescribed species but seemed to be 

generically identical with certain forms of the Torrejon. 

To this I can now add that one of these (catalogue No. 

6734) is very close to if not identical with Polycodus ralstoni, recently described by Matthew 1 from beds in the 

Clark Fork basin, Wyo., designated by Granger 2 the 

Sand Coulee beds and regarded as transitional in age between the Fort Union (represented in northwestern New 

Mexico by the Puerco and Torrejon) and the Wasatch. 

This suggests that the other specimens may also prove to 

belong to this horizon, especially as it now seems very 

evident that many of the Fort Union forms have passed 

without much change into the basal Wasatch. 

I Matthew, W. D., The Cretaceous-Tertiary problem: Geol. Soc. 

America Bull., vol. 25, pp. 387-402, 1914. 2 Granger, Walter, On the names of lower Eocene faunal horizons of 

Wyoming and New Mexico: Am. Mus. Nat. Hist. Bull., vol. 33, pp. 

204-205, 1914. 

As the Clark Fork beds and Sand Coulee beds of Granger, 

which contain both Fort Union and Wasatch forms are 

regarded as a transitional phase, there appears to have 

been no great time break between the Fort Union and 

Wasatch formations. A series of beds near Ignacio, Colo;, 

mapped by Gardner 3 as Wasatch, also appears to contain 

a fauna intermediate between Fort Union and Wasatch. 

The fossils from this locality are not numerous, but they 

show the presence of Coryphodon (species not determinable) in the upper levels. The lower levels contain a 

phenacodont, intermediate between Phenacodus of the 

Wasatch and Euprotogonia of the Torrejon; He:miacodon 

(probably a new species); a Bridger genus; and Nothodectes sp., a genus from Granger's Clark Fork beds 2 (species 

may also be identical). A few other teeth in the collection appear to be species belonging to the Clark Fork beds. 

Coryphodon and Eohippus are not known to occur lower . 

than the beds designated by Granger Sand Coulee beds. 

Therefore, as Coryphodon has been found in the Pumpkin 

Buttes locality and as Loomis has reported Coryphodon 

and Eohippus from the Davis ranch locality it seems 

reasonable that these beds should be classed with the 

Wasatch formation and that those at the Davis ranch 

should be regarded as probably equivalent to one of the 

lower ·members of this group, either the Sand Coulee or 

the Clark Fork of Granger. 

It is evident, then, that the fresh-water beds 

above the Fox Hills sandstone in this part of 

Wyoming comprise at the base a formation 

3,200 feet in thickness which bears Triceratops 

in its lower 2,000 feet and which is unquestionably Lance, at the top a formation 2,400 feet 

in thickness which ·bears Coryphodon and is 

therefore Wasatch, and intermediate between 

these two a formation 2,000 feet in thickness 

which bears Fort Union leaves in abundance 

and which probably represents that formation. We may therefore refer to the rocks of 

the Great Pine Ridge as the Fort Union of 

this region, and to the formation overlying it 

as Wasatch. 

That theW asatch rests unconformably upon 

the Fort Union would seem to be indicated by 

the following observations: At Kmgsbury 

Ridge, 8 miles ·southwest of Buffalo and about 

50 miles northwest of the Pumpkin Buttes, is a 

thick conglomerate named by Darton 4 the 

Kingsbury, which appears to represent a great 

alluvial fan, its outcrop being some 40 miles in 

length from north to south and 2 to 5 miles in 

width from east to west. (See PL XXIII, B.) 

It was apparently deposited by streams which 

flowed from the highest part of the Big Horn 

Mountains and which had, pnor. to the deposia Unpublished material. 

• Darton, N. H., Geology of the Bighorn Mountains: U.S. Geol. 

Survey Prof. Paper 51, p. 61, 1906. 
60 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

tion of the conglomerate, cut deep valleys in the 

underlying beds. The conglomerate thus rests 

unconformably on the rocks below it, transgressing at Kingsbury Ridge strata ranging in 

age from Tertiary to Carboniferous. Its greatest thickness is estimated by Darton 1 as 2,500 

feet. In recent Survey reports it has been 

treated as a member of the Fort Union formation. It is certainly younger than the Fort 

Union beds on which it rests toward the south, 

and in that direction also the conglomerate as a 

member thins out within a few miles, although 

layers a few inches to several feet in thickness 

can be found at or near its horizon as far south 

as Powder River. To the east the Kingsbury 

conglomerate appears to become finer grained 

and to :finger out into the shale and sandstone 

of the coal-bearing beds that are now believed 

to be of Wasatch age. In other words, it is the 

writer's opinion that the Kingsbury conglomerate is equivalent to part of the Wasatch, and 

that the unconformity at its base separates that 

formation, in the Kingsbury region at least, 

from all older rocks. 

Along the Dry Fork of Cheyenne River 35 

miles south of Pumpkin Buttes and 90 miles 

southeast of Kingsbury Ridge there is some 

evidence of an unconformity between the 

Wasatch and underlying Fort Union beds. The 

Dry Fork of the Cheyenne heads in the Great 

Pine Ridge, and along its valley there are exposed two beds of coal stratigraphically about 

160 feet apart. The lower coal bed is only a few 

feet above the top of the Fort Union as exposed 

in the Great Pine Ridge. The upper coal bed 

may be traced eastward along the Cheyenne 

I Darton, N.H., Geology of the Bighorn Mountains: U.S. Geol. Survey 

Prof. Paper 51, p. 61, 1906. 

Valley for about 10 miles from the ridge to a 

point where both the lower and upper beds are 

exposed, together with about 50 feet of strata 

underlying the lower bed. There is no indication at this locality of the highly ferruginous 

layers characteristic of the Fort Union. Still 

farther east along the Cheyenne lower rocks are 

exposed, including a third coal bed that lies 

about 220 feet below the lower coal bed above 

described. The rocks associated with this 

third bed are in appearance Wasatch rather 

than Fort Union. A coal bed, therefore, which 

at the head of the Dry Fork of the Cheyenne 

rests almo_st directly on the Fort Union beds 

has below it in an area 15 miles farther east at 

least 27 5 feet of strata that appear to be W asatch, and it seems probable that an unconformity is here present between the two formations. Inasmuch, however, as the coal beds in 

the lower part of theW asatch do not extend for 

any great distance north and south in the region 

of the Fort Union outcrop, and as there are, besides the coal beds, no· other key rocks that are 

easily recognizable in the lower part of the W asatch, it is impossible to prove conclusively the 

amount of the unconformity. 

In summary, we :find in the region southeast 

of the Big Horn Mountains three fresh-water 

formations above the marine sandstone of the 

Fox Hills; the lowest of these is Lance, the highest Wasatch, and the intermediate formation 

may reasonably be considered to be Fort Union. 

A local unconformity is known to exist in the 

vicinity of Buffalo between the Wasatch and 

Fort Union, and there is evidence to indicate 

that this u,nconformity is present, although less 

evident in other parts of the Powder River 

basin. 

0 
DEPARTMENT OF THE INTERIOR 

FRANKLIN K. LANE, Secretary 

UNITED STATES GEOLOGICAL SURVEY 

GEORGE OTIS SMITH, Director 

Professional Paper 108- E 

GEOLOGIC HISTORY INDICATED BY THE FOSSILIFEROUS 

DEPOSITS OF THE \YILCOX GROUP (EOCENE) 

AT lVIERIDLAN, lVIISSISSIPPI 

BY 

ED\VARD vVILBER BERRY 

Published June 22, 1917 

Shorter contributions to general geology, 1917 

(Pages 61-72) 

W AS}IING1~0N 

GOVERNMENT PRINTING OFFIOE 

1917 
. . 

CONTENTS. 

Page. 

Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 

The locality . ..................................... ,_ ............................... •......... . ............. 61 

Geologic interpretation ......................................................................... : ... , . . . . 62 

Two new species of fossil plants ...................................................................... ,· . . . 63 

ILLUSTRATIONS. 

Page. 

FLATES XXIV-XXVI. Nelumbo protolutea Berry, n. sp .......................................... : ........... 70-72 

FIGURE 17. Zamia mississippiens1:s Berry, n. sp............................................................ 63 

18. Sketch map showing the existing and geologic distribution of Nelumbo .. . . • . . . . . . . . . . . . . . . . . . . . . . 67 

II 
GEOLOGIC HISTORY INDICATED BY THE FOSSILIFEROUS DEPOSITS OF 

THE WILCOX GROUP (EOCENE) AT MERIDIAN, MISSISSIPPI.· 

By EDWARD WILBER BERRY. 

INTRODUCTION. 

The presence of erosion intervals at several 

horizons in the Eocene of the Gulf States has 

been pointed out in a recent paper/ and the 

evidence of an erosion interval between the 

period of deposition of the sediments of the 

Wilcox group (lower Eocene) and that of the 

Claiborne group (middle Eocene) ·was reviewed 

in some detail in a general discussion. of the 

extensive flora of the Wilcox group of that 

region. 2 This evidence was not entirely conclusive ·and was based on the littoral character of 

the basal Claiborne, the occurrence of autochthonous beds of 'lignite at the base of the 

Claiborne at certain localities in the northern 

part of the Mississippi embayment, the great 

change between the Wilcox and Claiborne 

floras and faunas, and the reported unconformities in western Georgia 3 and in southwestern Texas.4 Recently E. N. Lowe, 5 State 

geologist of Mississippi, discovered a westward 

extension into that St·ate of the glauconitic 

shell marl of the Bas hi ("Woods Bluff") formation of southern Alabama. C. W. Cooke, of 

the United States Geological Survey, visited 

this region in the spring of 1916 and collected 

fossil plants at Meridian, Miss. This collection 

contained two new and important plants, and 

1 Berry, E. W ., Erosion intervals in the Eocene of the. Mississippi embayment: U. S. Geol. Survey Prof. Paper 95, pp. 73-82; 1916. 

2 Berry, E. W ., The lower Eocene floras of southeastern North America: 

U.S. Geol. Survey Prof. Paper 91, pp. 3~38, 1916. 

a Veatch, Otto, and Stephenson, L. W., Preliminary report on the 

geology of the Coastal Plain of Georgia: Georgia Geol. Survey Bull. 26, 

p. 228, 1911. 

• Dumble, E . T., Some events in the Eocene history of the coastal area 

of the Gulf of Mexico in Texas and Mexico: Jour. Geology, vol. 23, pp. 

481-498, 1915. 

5 Lowe, E. N ., Mississippi, its geology, geography, soils, and mineral 

resources: Mississippi Geol. Survey Bull. 12, p. 71, 1915. 

76975°- 17 

it is the purpose of the present paper to discuss 

briefly these additions to the flora of the Wilcox 

group and the new evidence of the u:n,con·-

formity between the Wilcox and the Claiborne 

groups afforded by this outcrop .. 

THB LOCALITY. 

The outcrop from which the fossil plants were 

obtained is in the southeastern part of the town 

of Meridian, Miss., on a hillside immediately 

south of the Meridian & Memphis Railway, in 

an extensive excavation for the: fill leading to. 

the overhead crossing of the 1~o bile & Ohio 

Railroad, 200 yards east of that crossing. The 

section, for which I am indebted to Mr. Cooke, 

shows the following sequence: 

Section at Meridian, Miss. 

Fine yellow incoher-ent sand with .flat, disklike 

pebbles of clay and thin beds of clay, some of 

Feet. 

which show apparent ripple marks._.~. __ . __ .. 15-20± 

Probable unconformity. 

Gray to brown and black hackly clay, very sandy 

in places, with much lignitic matter; impressions of leaves abundant near the top"··.. . .... 30± 

Greenish-yellow fine incoherent glauconitic sand 

with large spheroidal indurated masses crowded 

with fossil shells ( Venericardia planicosta, Pseudoliva petrosa tuomeyi, Solariella louisiana, 

etc.), characteristic of the Bashi (" Woods 

Bluff") formation of the Wilcox group......... 12 

The fossil plants were col1ected from the end 

of the cut nearest to the railroad crossing, and 

the base of the section is a little higher than 

the flood plain of Souwashee Creek. The 

basal member contains an abundant marine . 

fauna, which Mr. Cooke states is characteristic 

of the Bashi formation of the Alabama section. 

The overlying member is packed with plant remains in its upper layers. The :following t able 

61 
62 SHORTER CONTRIBUT'IONS TO GENERAL GEOLOGY, 1917. 

enumerates those that are determinable and 

gives their known range: 

Sped,es of fossil plants occurring at Meridian, Miss. 

Previously known range. 

Lower Middle Upper 

Wilcox. Wilcox. Wilcox. 

-----~------------ ---~------ ----

Lygodium binervatum (Lesquereux) Berry __ ---------- X 

Zamia mississippiensis Berry, 

(?) 

n. SP-----.--- -------------- ____________ ____________ _ Sabalites grayanus Lesquereux X X 

Ficus puryearensis Berry- . _ _ _ X X X 

N elumbo protolutea Berry, n. 

SP-------------------------------.--------- -------- Gleditsiophyllum eocenicum 

Berry .... ______ . _ ---- - - - --- X 

Dalbergites elliptic i foli us Berry _____________________ _ 

Sapindus formosus Berry __ . _ _ X 

Sap indus mississippiensis Berry. ____________________ _ 

Mespiloda phne eol igni t ica 

Berry-.- .... _ - _ - _ -- - - - -- - -- X 

Mespilodaphne pseudoglauca Berry_____ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ X 

N ectandra lowii Berry .. _ . _ - _ X 

Combretum obovalis Berry __ _ Aralia acerifolia Lesquereux __ 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

This rather obvious correlation is not, however, the feature of especial interest in the 

Meridian section. The significance of that section lies in the facts that at the base the material 

is a glauconitic sand with an abundant faunaobviously a shallow-water marine depo~it-and 

that these marine sands pass imperceptibly upward into sandy lignitic clays which must be 

interpreted, in part at least, as true continental 

deposits, thus clearly presaging the withdrawal 

of the sea during the interval between the Wilcox and the Claiborne. 

The presence of land plants and scattered 

lignitic material (allocthonous) in the sediments 

argues for the nearness of a vegetation-covered 

shore. T?e legitimate evidence in the Meridian 

locality, however, justifies more than this inference, for the upper layers of the middle member 

are not only filled with 'the remains of land 

plants but contain in addition the rootstocks 

and abundant leaves of what appears to be the 

Eocene ancestor of the American Lotus. This 

species (Nelumbo protolutea) belongs to a genus 

whose known .living representatives are large 

perennial herbs growing exclusively in shallow 

and still fresh water, or nccasionally in water 

It will be seen that of the 14 species identified that is only very slightly brackish. Were the 

from Meridian, three occur in the lower Wilcox leaves the only traces of this plant present in 

or Ackerman formation, eight In the middle the deposits they might be interpreted as havWilcox or Holly Springs sand, and twelve, or all ing been drifted into an estuary, although their 

but the two new species, in the upper Wilcox or great abundance in all sizes and the fact that 

Grenada formation. In addition it should be the leaves are not deciduous but would have to 

noted that several recorded from , the middle be torn away from their stout petioles are opWilcox are found only near the top of that divi- posed to such an interpretation. But inassion, so that the present assemblage would be much as the clays c0ntain-rootstocks whic:h 

referred unhesitatingly to the upper Wilcox or during life creep in the mud at the bottoms of 

Grenada formation even were its stratigraphic ponds, and as a great abundance of rootlets 

position unknown. permeate the clays in every direction, many of 

GEOLOGIC INTERPRETATION. them .with the root hairs preserved, it is obvious 

that these remains were not transported but 

The· Bashi formation of the Alabama section 

Is overlain by the Hatchetigbee formation, 

which contains an obviously shallow-water 

marine fauna. It would seem indisputable 

that the lignitic sands overlying the glauconitic 

marl at Meridian correspond to the Hatchetigbee formation as it occurs to the southeast ·in 

Alabama and also to the Grenada formation as 

it occurs to the northwest. The Hatchetigbee 

fauna indicates the shallowest-water assemblage of Mollusca represented in the ·Alabama 

- section of the Wilcox group 

grew on the spot where they are now found~ 

They thus afford a record for this locality of 

a period of changing conditions during which 

greensands carrying a marine fauna became 

replaced by littoral sands and muds and these in 

turn were overlain by the sandy muds of what 

was probably a shallow pond containing a vigorous growth; of innumerable nelumbos or 

lotuses and receiving the leaves that fell from 

the trees along its shores. 

The section at Meridian, as interpreted by Mr. 

Cooke, ·appears to show an unconformity above 
GEOLOGIC HISTORY OF THE WILCOX GROUP A'l' MERIDIAN, MISS. 63 

the plant bed, and the uppermost member-a 

fine yellow sand-contains disklike pebbles 

of waterworn clay, of a type usually associated 

~ith rather quiet wave action on beaches, and 

thin beds of clay that appear to have been 

ripple marked. These clay beds and pebbles 

may be local in c·haracter or they may n1ark the 

beginning of the Claiborne transgression. 

The conclusion seems justified that the 

upper Wilcox was a time during which the 

open sea became gradually smaller as the strand 

line moved southward, and that there was an 

interval of emergence between the deposition 

of the Wilcox and that of the Claiborne group, 

an interval whose considerable length is indicated by the great contrasts between the terrestrial fl'oras and the marine faunas of the 

Wilcox and the Claiborne. 

The locality at Meridian is the southernmost 

point in the Wilcox outcrop where fossil plants 

have been found, and if this locality, so far to 

the south, thus clearly indicates the succession 

of events between the last \Vilcox marine fauna 

and the transgressing sands of the lower 

Claiborne sea, it is obvious that a similar succession and a longer- erosion interval characterized that great area of the Mississippi embayment which lies to the north of Meridian. 

TWO NEW SPECIES OF FOSSIL PLANTS. 

The two new species described below are of 

especial interest in that the Nelumbo adds an 

entirely new type to the Wilcox flora, representing a family hitherto unknown in that 

.remarkable assemblage of b-etween 300 and 400 

species, and the second adds a new cycad 

(Zamia), represented by fronds, the only known 

cycad from the American Tertiary except a 

single piece of a pinnule of another species of 

Zamia from the Wilcox, previously described. 1 

Class GYMNOSPERMAE. 

Order CYCADALES. 

Family CYCADACEAE. 

Genus ZAMIA Linne. 

Zamia mississippiensis Berry, n. sp. 

Although Zamia-like foliage is very con1mon 

and widespread in :Mesozoic deposits the world 

over and more than 30 species of Zamia still 

exist in tropical and subtropical America~ including two that occur in the Floridian region, 

I Berry, E. W., U. S. GeG>l. Survey Prof. Paper 91, p. 169, pl. 114, 

fig. 2, 1916. 

only a few cycads have thus far been discovered in Tertiary depos.its anywhere~ Much 

interest therefore attaches to the present discovery of a small-leafed form of Zamia. . 

Leaves elongate, slender, and linear. Rachis 

stout. Pinnules small, crowded, opposite or 

subopposite, bluntly pointed, constricted proximad to a relatively broad inequilateral base, 

attached to the sides of the top of the rachis. 

Length 1.25 to 1.50 centimeters; 1naximum 

width about 2 n1illimeters. Margins entire. 

Texture coriaceous. Venation consisting of 

eight to ten longitudinally subparallel veins, 

a few of them dichotomous proximad. 

· This characteristic Zamia is represented in 

the present collections by three specimens, two 

of which are shown in the accompanying 

b c 

FIGURE 17.-Zamia mississippiensis Berry, n. sp. a, Specimen showing traces of 14 pair~ of pinnules; b, specimen with slightly larger 

pinnules; c, pinnule enlarged 4 diameters to show form and venation . 

figures. In the specimen represented in figure 

17, b, which shows a portion of the pinnulebearing part of a. rachis 4.4 centimeters long, 

the pinnules are slightly larger than in the other 

specimen figured and . are more scattered, but 

this is due to the loss of the intervening pinnules. In the other specimen '(fig. 17, a) a 

similar pinnule-bearing part of the rachis 4. 7 

centimeters long shows traces. of 14 pairs of 

pinnules. The rachis is somewhat. more 

slender than in the specimen shown in figure 

17, b, and the pinnules are slightly smaller. 

The unfigured specimen shows 5 centimeters of 

pinnule-bearing rachis with traces of 12 pairs 

of pinnules. 

The8e remains evidently represent a Zamia 

with slender, graceful leaves and much reduced pinnules, somewhat suggestive of the 
64 SHORTER CONTRIBUTIONS . TO .GENERAL GEOLOGY, 1917. 

existing Zamia floridana De Candolle, which 

· inhabits the so~called flatwoods of the east 

coast of Florida south of New River. 

In my account of the lowerEocene flora of 

southeastern North America1 I described as 

Zamia? wilcoxensis a single broken pinnule of 

cycad which I compared with the existing 

Floridian Zamia pumilaLinne. It is interesting 

to find the remains of a second species smnewhat resembling the only other living Florida 

species at a horizon as old as the lower Eocene. 

The two species, though based on a rather 

meager amount of material, are apparently 

distinct, for Zamia? wilcoxensis has pinnules 

with more than twice as many veins as· the 

pinnules of Zamia mississippiensis. It is of 

course possible that the two occurrences 

represent the extremes of variation of a sing~e 

lower Eocene species, but I do not regard this 

as probable. 

Only five or six other Tertiary species of 

cycads are known, and most of these are based 

on poorly preserved or unrepresentative ~aterial. The only non-European form Is an 

undoubted species of Zamia from the Eocene 

of -Coronel, Chile, described by Engelhardt.2 

The oldest known Tertiary species is Zamites 

palaeocenicus, fro~ the Thanetian of Gelinden, 

Belgium, described by Saporta and Marion. 3 

Meschinelli 4 described a species from the 

Stampian of Venetia, Italy, whic~ he referred 

to Oeratozamites, and two species have been 

recorded from the lower Miocene (Aquitanian) 

of Europe-a Zamites from southern France 5 

and a well-marked Encephalartos from Kumi, 

in Greece. 6 Heer 7 recorded a species of 

Zamites from the Helvetian of Switzerland and 

a species of Oycadites from the Tortonian of 

that country, but both of these are rather 

doubtful determinations. 

The small amount of material on which the 

present species is based is nevertheless suffi1 Berry, E. W., U. S. Geol. Survey Prof. Paper 91, p. 169, pl.l14, 

fig. 2, 1916. 

2 Engelhardt, H., Ueber . Tertili.rpflanzen von Chile: .Senckenberg. 

naturf. Gesell. Abh., Band 16, p. 646, pl. 2, fig. 16, 1891. 

a Sa porta, Gaston de, and Marion, A. F., Revision de la floreheersienne 

de Gelinden, p. 20, pl. 1, figs. 4, 5, 1878. 

4 Meschinelli, L., Studiosulla flora fossile di Monte Piano: Soc. venet@-

trentina Sci. Nat. Atti, "\rol. 10, p. 276, pl. 6, Padua, 1889. 

o Saporta, Gaston de, Sur la decouverte d'une cycadee dans le terrain 

tertiaire moyen -de Provence: Soc. geol. France Bull., 2d ser., tome 21, 

pp. 314-328, pl. 5, 1864. 

6 Sa porta, Gaston de, Notice sur l' Encephalartos gorceixianus, cycadee 

fossile, du depot miocene de Koumi (Eubee): Soc. bot. et hort. Provence Bull., pp. 41- 44, 1 pl., 1880. 

7 Heer, Oswald, Flora tertiar\a Helvetiae, vol. 1, p. 46, pl. 15; pl. 16, 

fig. 1, 185.5. 

cient to establish the undoubted relationship 

of the fossil, as the accompanying text figures 

show, and it is quite possible that future 

research will reveal other members of this 

interesting family in the later Tertiary deposits 

of this region, as the plants thus far collected 

from the upper Eocene and lower Oligocene 

are more tropical in character than those from 

the lower Eocene. 

Class ANGIOSPERMAE. 

Order RANALES. 

Family NYMPHAEACEAE. 

Genus NELUMBO" Adanson. 

Nelumbo protolutea Berry, n. sp. 

Plates XXIV-XXVI. 

Leaves of all sizes, orbicular or suborbicular 

in outline, peltate. Petioles stout, that of one 

of the smaller leaves being 5 millimeters in 

diameter. Margins slightly undulate. Texture coriaceous. Primaries numerous, radia1;-

ing from the center of the leaf, about 25 in 

number (this is the number in the central fragment of the very large leaf figured in Pl. XXIV, 

fig. 2, as it is also in leaves not over half 

the size), stout, prominent on _the under side 

of the leaves. Although all the primaries 

are approximately equal in size they appear 

to be more cr0wded in one-half of the leaf than 

in the other, as in the large leaf figured (Pl. 

XXIV, fig. 2), where the ratio in the one-half 

to the other is 10 to 15. They pursue rather 

uniformly straight courses but fork dichotomously three or four times; the first dichotomy 

is somewhat more than half the distance to· 

the margin. The angles of the dichotomies 

are about 30°. In some specimens the primary 

remains straight and the second~ries are curved, 

a~ in the vertical primary shown · -in Plate 

XXIV, figure 2. The marginal dichotomy is 

tiny, and the ultimate parts of the forking of 

adjacent primaries are united by a broad loop 

or arch subparallel with the margin, as shown 

in Plate XXIV, figure I, and Plate XXV, 

figure 2. The tertiaries are thin and 'percurrent, or they inosc-qlate midway between adjacent primaries. Areolation very fine but 

well marked, forming isodiametric ,hexagonal 

meshes, well . shown ·enlarged twice in Plate 

XXVI, figure 3. 

The diameter of the larger leaf figured (Pl. 

XXIV, fig~ 2) is estimated as 32 centimeters; 

that of the leaf shown in Plate XXV, figure 2, . 
GEOLOGIC HISTORY OF THE WILCOX GROUP AT' MERIDIAN, MISS. 65 

at 28 centimeters; that of the leaf shoWn in 

Plate XXV, figure 4, at 15 or 16 centimeters; 

and that of the small leaf shown in Plate XXV, 

figure 3, at 7 centimeters. The clays at this 

locality are packed with fragments of large 

leave~, so that the normal diameter seems to 

have been between 25 and 35 centimeters. 

The leaves were probably normally concave, 

as in the existing species, and several are preserved with the two halves of the upper surface in apposition. A fragment showing this 

method of preservation is shown in Plate XXV, 

figure 1. 

Associated with the leaves are fragments of 

the rootstock, most of them poorly preserved 

· but showing traces of nodes with leaf cushions 

and rontlet scars. In Plate XXVI, figure 2, 

) are shown the flattened rootlets radiating from 

a node, and figure 1 on the same plate shows 

the rootlets and root hairs. Traces of rootlets 

are very common in the clays and serve to indicate that this species grew at the exact locality 

where it was preserved, as might also· be inferred from its great abundance. Associated 

with these remains are a few rather poorly preserved oblate-spheroidal seeds, about 1.3 centimeters long and 0.8 centimeter in diameter, 

which I consider as representing the seeds of 

this species, although they are too poorly preserved for exact diagnosis. No traces of the 

characteristic large torus of this genus have yet 

been discovered at this locality. 

This new species is wholly unlike any American Tertiary species heretofore known and is 

larger and much better preserved. Among the 

considerable number of European ·Tertiary 

forn1s it resembles somewhat Nelumbo b·uchii, 

from Monte Promina, in Dalmatia, as figured 

by Ettingshausen,t and Nelumbo protospeciosum 

from the Aquitanian of southern France, described by Saporta.2 The latter is one of the 

most completely known fossil forms. It is 

represented by large and small leaves showing 

the details of areolation, by traces of flowers 

(stigmatic disks), and by seeds. Sa porta considers it in the direct line of descent to the 

existing sacred lotus of India ( Nelumbo nelumbo), which it certainly· resembles very 

much. This French species is more like the 

1 Ettingshausen, Constantin von, Die eocenel Flora des Monte Promina 

in Dalmatien: K. Akad. Wiss. Wien Denkschr., Band 8, p. 36, pl. 10, 

figs. 2, 3; pl. 11, fig. 1; pl. 12, 1855. 

2 Saporta, G. de, Recherches sur la vegetation du niveau aquitanien 

de Manosque, p. 17, pl. 1, figs. 2, 3; pl. 4, figs. 1, 2, 1891. 

Wilcox form than . any other previously described, and if the two occurred at the same 

horizon it would be impossible to distinguish 

them by their foliage alone. Nelumbo protospeciosum is probably descended from Nelumbo 

provinciale, from the Upper Cretaceous lignites 

of Fuveau, in Provence, referred by Saporta 

to the Campanian stage but now usually considered as forming a part of the Aturian stage. 

The existing species of N elumbo are two in 

number, both magnificent plants. One, the 

Indian lotus, Nelumbo nelumbo (Linne) Karsten, is found in the southeastern Asia~ic region 

from southern Japan to northern Australia and 

ranges westward as far as the Caspian . Sea. 

The other, the American lotus or· g:r:eat water 

lily, Nelumbo lutea (Willdenow) Persoon, is 

found in eastern North America from Ontario 

and Michigan to Florida and Louisiana and 

southward in the West Indies and northern 

South America, extending as far as latitude 

7° S. in Brazil. 

Any genus of plants represented by but two 

closely related existing species, each with a 

comparable habitat and distribution and separated by the breadth of the Pacific Ocean, is 

sure to have had a long geologic history during 

,which the aneestors of the existing species 

oceupied the intervening land areas. That 

Nelumbo had such a history has long been 

known, a1_1d a considerable number of fossil 

species have already been described. · The 

oldest are forms with small leaves for which I 

have proposed the generic term Nelumbites 3 and 

which are common in the Patapsco formation 

of the Potomac group in Maryland and Virginia (late Lower Cretaceous or Albian in age) 

and occur also in the earlier Upper Cretaceous 

of North America. Of about the same age or 

somewhat younger are Nelumbium lusitanicum 

and Nelumbium choffati, reported by Saporta 4 

from the supposed Albian oi Portugal, neither 

of which has been figured or adequately described. 

A species of especial interest_in the present 

connection is Nelumbo kempii Hollick, 5 which 

occurs in the Magothy formation of Long 

Island and New Jersey, for it appears to be 

a Berry, E. 'vV., Maryland Geol. Survey, Lower Cretaceous, p. 462,1911. 

'Saporta, G. de, Nouveaux details concernant les Nympheinees: 

Compt. Rend., vol. 119, pp; 835-837, 1894. 

5 Hollick, Arthur, The-Cretaceous flora of southern New York and New 

England: U.S. ·Geol. Survey Mon. 50, p. 6'1, pl. 13, figs. 1-4; pl. 14, figs. 

1, 2; pl. 15; pl. 16, figs. 1-6, 1906. 
66 SHORTER. CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

the logical ancestor of Nelumbo protolutea of Europe; N. nymphaeoides Ettingshausen,11 from · 

the Wilcox, thus paralleling Nelumbium pro- the Oligocene of Europe; and N. casparianum 

vinciale Saporta,t of the Aturian of southern Heer/2 N. ettingshauseni Sieber/3 and N. 

France, which seems to be the ancestor of hungarica Tuzson/4 from the Miocene of Europe. 

Nelumbo · protospeciosum Sa porta, in turn lead- One species, N. minima Clement and E. M. 

ing to the existing Indian lotus. Other Upper Reid/5 is recorded from the Pliocene of northern 

Cretaceous species are Nelumbium schwein- Europe, and the genus is also represented by 

furthi Couyat and Fritel,Z from the Aturian of rhizomes in the late Tertiary of Japan. 

Assouan, Egypt; Nelumbium arcticum Heer/ The remains referred to these several species 

from the Atane beds of western Greenland; comprise leaves, flower parts, rhizomes, rootNelumbo intermedia Knowlton, 4 from the Mon- lets, characteristic fruits, · and seeds, and they 

tana group of the West; ahd Nelumbo dawsoni clearly establish the once cosmopolitan range 

Hollick,S from the Belly River beds of Canada. of the genus, at least in the Northern 'Remis.:. 

The two latter are small-leafed forms, possibly phere, and its former abundance in Europe and 

referable to Nelumbites; residence there as late as the upper Plioce'ne. 

Besides several poorly characterized forms, The existing Nelumbo nelumbo, · therefore, 

the following 'more definite species may be appears to be a species whose extinction in 

mentioned from the Tertiary: Nelumbo lakesi- Europe was brought about by the unfavorable 

anum Lesquereux 6 and N. tenuifolium Les- conditions that existed during the Pleistocene 

quereux/ from the early Tertiary of Colorado; epoch but which survived in eastern and 

N. palaeocenicum Fritel,8 from the Sparnacian, :;outhern Asia, as did its only existing ally, 

or lower Eocene; of the Paris Basin; N. micro- Nelumbo lutea, in eastern North America, by 

carpum Ettingshausen/ from the Ypresian, or the opportunities afforded it to withdraw 

lower- Eocene, of England; N. buchii Ettings- southward beyond the reach of adverse con-: 

hausen/0 which is found at a number of ditions-opportunities which Europe, with its 

localities in the Oligocene and Miocene of high east-west mountain ranges and interior 

. . . l seas, failed to furnish. 1 Sa porta., Gaston de, Le Nelumbzum provmczale: Soc. geol. France Pal. I d t · }" . th f t t f th · th mem. 5, 1890. · n or er o VIsua 1ze e ac s se or 1n e 2 Couyat, J., and Fritel, P. H., Sur la presence d'empreintes vegrtales preceding discussion I have assembled them on 

dans le gres nubian des environs d'Assouan: Compt; Rend., vol. 151, th · k t h m (fi 18) whi h p. 963, 1910. e accompanying s e c ap g. . , c 3 Heer, Oswald, Flora fossilis arctica, vol. 6, Abt. 2, p. 92, pl. 40, fig. 6, shows the approximate range of the two 1882· existing species of Nelumbo by the obliquely 4 Knowlton, F. H., ·Flora of the Montana formation: U.S. Geol. Survey Bull. 163, p. 53, pl. 13, figs. 3-5, 19oo. lined areas and such Cretaceous and Tertiary 5 Hollick, Arthur, A new fossil Nelumbo from the Laramie group at records as OCCUr OUt&ide these areas by solid 

Florence, Colo.: Torrey Bot. Club Bull., vol. 21, p : 309, 1894. 

6 Lesquereux, Leo, The Tertiary flora: U. S. Geol. Survey Terr. Rept., black circles· 

vol. 7, p. 252; pl. 46, figs. 1, 2, 1878. · ----.,--------------------

7 Idem, p. 253, pl. 46, fig. 3. n Idem, p. 37, pl. 10, fig. 1; pl. 11, fig. 2. 

a J?ritel, P. H., Note sur trois nympheacees nouvelles du Sparnacien 12 Heer, Oswald, Flora tertiaria Helvetiae,· vol. 3, p. 299, 18.59. 

des environs de Paris: Soc. geoL ·:France Bull., 4th ser., vol. 8, p. 472, 13 Sieber, Johann, Zur Kenntniss der nordbohmischen Braunkohlenpl. 10, fig. 3

, 1908. flora: Akad. Wiss. Wien Sitzungsber., Band 82, p. 83, pl. 2; figs. 15, 16, 

9 Ettingshausen, Constantin von, Report on phyto-palaeontological ~2Tuzson,' Janos, A. Zsilvolgy egyuj Harmadkori novenye: Magyar 

investigations of the fossil flora of Sheppey: Roy. Soc. London Proc., tud. Akad. Math. Termeszettud., Ert. 29, pp. 827-829, 1911; Beitra.ge zur 

vol. 29, P· 395, 1879. fossilen Flor3 Ungarns: K. ung. geol. Reichsanstalt Jahrh., vol. 21, p. 10 Ettingshausen, Constantin von, Die eocene Flora des Monte Promina 257, pl. 17, fig. 3; pl. 19, figs. 2, 3; pl. 20; pl. 21, figs. 1, 2, 1914. 

in Dalmatien: K. Akad. Wiss. Wien Denk:schr., Band 8, p. 36, pl. 10, 15 Reid, Clement and E. M., The Pliocene floras of the Dutch-Prussian 

figs. 2, 3; pl. 11, fig. 1; pl. 12,.1855. border, p. 85, pl. 6, fig. 20 a, b, 1915. 
FIGURE 18.-Sketch map showing the existing and geologic distribution of Nelumbo. 

67 
PLATES XXIV -XXVI. 

69 
PLATE XXIV. 

FIGURES 1, 2. Nelumbo protolutea Berry, n. sp., from the Grenada formation at Meridian, Miss. 

1. Specimen showing margin and marginal venation of a small leaf. 

2. Specimen showing the central part of a large leaf. 

70 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XXIV 

2 

NELUMBO PROTOLUTEA BERR~ 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XXV 

NELUMBO PROTOLUTEA BERRY. 
PLATE XXV~ 

FIGURES 1-4. Nelumbo protolutea Berry, n. sp., from the Grenada formation at Meridian, Miss. 

1. Specimen showing part of the under and upper surfaces of a small funnel-shaped leaf. 

2. Specimen showing inargin and marginal venation of a large leaf. 

3. Specimen showing part of a very small leaf. 

4. Specimen showing the central part of a medium-sized leaf. 

71 
PLATE XXVI. 

FIGURES 1-3. Nelumbo protolutea Berry, n. sp., from the Grenada formation at Meridian, Miss. 

72 

1. Specimen showing rootlets and root hairs. 

2. Specimen showing rootlets radiating from the node of a crushed rootstock. 

3. Fragment of a large leaf, enlarged 2 diameters, to show the well-marked hexagonal areolatiou 

and other details of the venation. 

0 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XXVI 

3 

NELUMBO PROTOLUTEA BERR~ 
DEPARTMENT OF THE INTERIOR 

FRANKLIN K. LANE, Secretary 

UNITED STATES GEOLOGICAL SURVEY 

GEORGE OTIS SMITH, Director 

Professional Paper 108-F 

A FOSSIL FLORA FROM THE FRONTIER FORMATION 

OF SOUTHWESTERN WYOMING 

BY 

F. H. KNOWLTON 

Published August 22, 1917 

Shorter contributions to general geology, 1917 

(Pages 73-107) 

WASHINGTON 

GOVERNMENT J?RINTING OFFICE 

1917 
CONTENTS. 

Page. 

Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 

Stratigraphic relations................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 

Age of the Frontier formation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 

General features of the flora............................................................. . . . ..... . ......... 77 

Species now recognized. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 

Localities and collectors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 

Biologic aspects of the flora. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 

Physical and climatic conditions indicated.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 

Evidence of insects in Frontier time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 

The flora ........................................... . ...... , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 

ILLUSTRATIONS. 

Page. 

PLATE XXVII. A, Plant-bearing shale in Frontier formation 1 mile east of Cumberland, Wyo.; B, White plantbearing shale in Frontier formation south of Little Muddy Creek, near Cumberland, Wyo.. 74 

XXVIII-XXXIX. Fossil flora from the Frontier formation·-··· ........................ . ........... 96-107 

II 
A FOSSIL FLORA FROM THE FRONTIER FORMATION OF SOUTHWESTERN 

WYOMING. 

By F. H. KNOWLTON. 

INTRODUCTION. 

This paper deals with a small but important 

fossil flora, now known to be of Colorado age, 

from the vicinity of Cumberland, Lincoln 

County, Wyo. It was for many years thought 

to be of Jurassic age, and only within the last 

decade has its stratigraphic position been established. Although small in number of species, this flora offers information bearing on the 

physical and climatic conditions that prevailed 

during early Upper Cretaceous time in this 

region, and, moreover, it furnishes a series of 

stratigraphic marks that may be used in the 

recognition of this horizon elsewhere. It h11s 

also a possibly important biologic bearing, for 

it shows the presenoe of certain plant types that 

are now found living in Polynesia. The presence of certain types of insects that lived in 

and on the plants is shown by their characteristic markings. Finally, this study has a historical and sentimental interest because it is 

based on material collected on the celebrated 

Fremont exploring expedition more than 70 

years ago and now rediscovered and redescribed. 

The fossil plants to be described in this paper 

were discovered in 1843 by Capt. John C. Fremont, while engaged on an exploring expedition that had for its object the finding of a 

''new and better road" over the mountains 

and plains to Oregon and northern California. 

On August 19, 1843, the expedition turned 

north from Fort Bridger, on the old Oregon 

Emigrant Road, and soon passed over Muddy 

Creek, near the present site of Carter, Uinta 

County, Wyo. The fossil plants were found 

somewhat farther north, on Little Muddy Creek, 

near the present line between Uinta and Lincoln counties. Fremont's description 1 of the 

discovery of the fossil plants is as follows: 

1 Fremont, J. C., Report of the exploring expedition to the Rocky 

Mountains in the year 1842, and to Oregon and north California in the 

years 1843-44: Twenty-eighth Cong., 2d sess., House Ex. Doc. 166, p.131, 

1845. 

August 19: A few miles from our encampment [of August 

18] the road entered a high ridge connecting the Utah with 

the Mud River chain; and in one of the hills near which 

we passed I remarked strata of a conglomerate formation. 

We crossed a ridge of this conglomerate and descended 

upon one of the heads of Hams Fork, called Muddy, where 

we made our midday halt. In the river hills at this place 

I discovered strata of fossiliferous rock having an oolite 

structure, which, in connection with the neighboring 

strata, authorize us to believe that here, on the west side 

of the Rocky Mountains, we find repeated the modern 

formations of Great Britain and Europe, which have hitherto been wanting to complete the system of North American geology. * * * 

In the afternoon we continued our road and, searching 

among the hills a few miles up the stream and on the same 

bank, I discovered among alternating beds of coal and 

clay a stratum of white indurated clay containing very 

clear and beautiful impressions of vegetable remains. 

This was the most interesting fossil locality I had met in 

the country, and I deeply regretted that time did not 

permit me to remain a day or two in the vicinity. * * * 

After remaining here only about an hour, I hurried off, 

loaded with as many specimens as I could conveniently 

carry. 

These plants were referred to James Hall,t 

then paleontologist to the State of New York, 

who named, described, and figured most of them 

in an appendix to Fremont's report. Hall also 

gave the following additional information concerning the locality, evidently derived from 

Fremont's notes: 

Longitude 111°, latitude 41! 0 , Muddy River: These 

specimens are of a yellowish-gray oolitic lil!lestone, containing turbo, cerithium, etc. The rock is a perfect oolite 

and, both in color and texture, can scarcely be distinguished from specimens of the Bath oolite. One of the 

specimens is quite crystalline, and the oolitic structure 

somewhat obscure. In this instance the few fossils observed seem hardly sufficient to draw a decisive conclusion 

r'egarding the age . of the formation; but, when taken in 

connection with the oolitic structure of the mass, its correspondence with the English oolites, and the modern 

aspect of the whole, there remains less doubt of the propriety of referring it to the oolitic period. A further collection from this interesting locality would doubtless 

1 Hall, James, Descriptions of organic remains collected by Capt. J. C. 

Fremont in the geographical survey of Oregon and north California: 

Idem, Appendix B, pp. 304-307, pis. 1, 2, 1845. 

73 
74 SHORTER CONTRIBUTIONS T'O GENERAL GEOLOGY, 1917. 

develop a series of fossils which would forever settle the 

question of the relative age of the formation. 

A few miles up this stream Capt. Fremont has collected a 

beautiful series of specimens of fossil ferns. The rock is 

an indurated clay, wholly destitute of carbonate of lime, 

and would be termed a ."fire clay." These are probably, 

geologically as well as geographically, higher than the 

oolite specimens, as the rocks at this place were observed 

to dip in the direction of N. 65° W. at an angle of 20°. 

This would show conclusively that the vegetable remains 

occupy a higher position than the oolite. Associated with · 

these vegetable remains were found several beds of coal 

differing in thickness. 

The stratum containing the fossil ferns is about 20 feet 

.thick, and above it are two beds of coal, each about 15 

inches. These are succeeded by a bed of sandstone_. 

Below the bed containing the ferns there are three distinct 

beds of coal, each separated by about 5 feet of clay. 

Before examining the oolitic specimens just mentioned I 

compared these fossil _ ferns with a large collection from 

the coal measures of Pennsylvania and Ohio, and it was 

quite evident that this formation could not be of the same 

age. There ate several specimens which I can only refer 

to the Glossopteris phillipsii (see description), an oolitic 

fossil; and this alone, with the general character of the 

other species and the absence of the large stems so common 

in the coal period, had led me to refer them to the oolitic 

period. I conceive, however, that we have scarcely sufficient evidence to justify this reference; and though among 

the fossil shells there are none decidedly typical of the 

oolite, yet neither are they so of any other formation; and 

the lithological character of the mass is not reliable evidence. Still, viewed in whatever light we please, these 

· fossil ferns must, I conceive, be regarded as mostly of new 

species and in this respect form a very important addition 

to the flora of the more modern geological periods. 

From the foregoing statement it appears 

that, although Hall tentatively referred these 

plants to the Oolite-that is, to the Upper 

. Jurassic-as perhaps the best disposition that 

could be made under the circumstances, he was 

by no means certain of their age. 

For more than 40 years after these plants 

were ·described and figured ·by Hall they remained in obscurity and practically lost. In 

1887 I found some of them, including five of 

the figured types, in the United States National Museum. They were without adequate 

labels and were thickly covered with dust and 

mingled with other material of miscellaneous 

and unknown origin. How they came into the 

possession of the National Museum, or where 

the rest of the collection is-if, indeed, it is in 

existence-,-is not now known. 

published 1 in 1888. Lesquereux changed a 

number of Hall's generic references-for example, Sphenopteris and Trichopteris to Thyrsopteris-but was evidently somewhat confused by the presence of apparent dicotyledonous leaves, which he forced into or compared with certairt genera of ferns and cycads. 

He referred them to the Jurassic, his statement 

being as follows: "What seems to me to be 

conclusive of the oolitic age of the plants is 

the number of fragments of small ferns referable to the genus Thyrsopteris, of which Heer 

has described a number of species from the 

Jurassic of Siberia." 

To return to the field relations of these 

plants, it appears that none of the Government expeditions that operated in this region 

after the early explorations of Fremont had 

happened to find the beds containing them, 

though they are now known to be conspicuous. 

A. C. Peale, of the Hayden Survey, studied the 

region a few miles to the north of the Cumberland area during the field season of 1877. He 

was therefore familiar in a general way with 

the stratigraphy of this part of Wyoming, and 

in 1898 he attempted to determine, in the office, 

from Fremont's account, the locality whence 

these fossils came but was not able to reach a 

satisfactory conclusion. The matter then 

rested for several years, until 1905. 

When A. C. Veatch, of the United States 

Geological Survey, · began his study of the coal 

and oil fields of this general region, Peale 

called his attention to this unique material 

and to the desirability of determining the true 

stratigraphic position of the original locality 

and of procuring additional collectio;ns. From. 

the knowledge Veatch soon acquired of the 

region, as well as from a careful consideration 

of the original notes of Fremont and Hall 

quoted above, the locality that furnished these 

plants was. determined to be on the south bank 

of Little Muddy Creek, about 1 mile -east of 

the present town of Cumberland. The account of this rediscovery was first given by 

Veatch 2 in a short article published in June, 

1906, and more at length in his formal report 3 

on the region in 1907. 

The great interest that attaches to these · • 1 Lesquereux, Leo, Recent determinations of fossil plants from Ken- · 

plants was recognized by me, and as Prof. Leo 'tucky, Louisiana, Oregon, etc., with descriptions of new species: u.s. 

Lesquereux was at that time engaged in study- Nat. Mus. Proc., vol. 11, PP· 37, 38, 1888. • • • • 2 Veatch, A. C., Age and type locality of the supposed Jurassic fossils 

mg and naming the miscellaneous fossil-plant collected north of Fort Bridger, Wyo., by Fremont in 1843: Am. Jour. 

material in the National Museum they were Sci., 4th ser., vol. 21, pp. 457- 460,1906. . • ' s Veatch, A. C., Geography and geology of a portion of southwestern 

sent to him for restudy, and his report was Wyoming: u. s. Geol. survey Prof. Paper 56, pp. 65-69, 1907. 
U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XXVII 

.A. PLANT-BEARING SHALE IN FRONTIER FORMATION," 1 MILE EAST OF CUMBERLAND, WYO. 

Photograph by T. W. Stanton. 

B. WHITE PLANT-BEARING SHALE IN FRONTIER FORMATION SOUTH OF LITTLE MUDDY CREEK, 

NEAR CUMBERLAND, WYO. 

Probably very near the original Fremont locality. Photograph by T. W. Stanton. 

A FOSSIL FLORA FROM THE FRONTIER. FORMATION OF SOUTHWESTERN WYOMING. 7 5 

Veatch made a considerable collection of 

plants on the north side of Little Muddy 

Creek, in sec. 29, T. 19 N., R. 116 W., and in 

this collection the matrix, as well as a number 

of species, are absolutely identical with the 

original material collected by Fremont and 

preserved in the United States National 

Museum. There can be no doubt, therefore, 

that the beds from which Veatch's collection 

was obtained arenot only at the same horizon 

but at the same or approximately the same 

locality as that which furnished the Fremont 

collection of 1843. 

STRATIGRAPHIC RELATIONS. 

The plants described in this paper occur in 

what is now known as the Frontier formation. 

This formation was named by W. C. Knight 1 

in 1902 from the coal town of Frontier, near 

which the beds are well exposed. It was 

defined as being" composed of very thick beds 

of compact sandstone, with shales and coals 

having an approximate thickness of 2,000 feet." 

Knight stated that it was characterized by the 

presence of Ostrea soleniscus, a long, slender 

oyster which has a maximum length of 12 

inches, but subsequent study has shown that 

this species also occurs several thousand feet 

above the designated top of the Frontier formation. 

The Frontier formation was further described by Veatch 2 as follows: 

The pronounced sandstone layer or group of sandstone 

layers, occasionally conglomeratic and containing numerous specimens of the elongate oyster mentioned, produces 

a pronounced ridge, which was named Oyster Ridge by 

Hayden in 1872. This name was adopted by the King 

Survey and used on the maps of that organization. This 

group of sandstones has therefore been named the Oyster 

Ridge sandstone member of the Frontier formation. At 

several places minor sandstones or oyster-bearing ridges 

occur above the Oyster Ridge sandstone. * * * The 

Oyster Ridge sandstone is generally about 200 feet thick. 

Beneath the Oyster Ridge sandstone there are other sandstone layers, which produce pronounced ridges, but these, 

except near the northern extremity of the map, are definitely separated from and not readily confused with the 

main Oyster Ridge sandstone. The total thickness of 

this formation ranges from 2,200 to 2,600 feet. It is exposed along the east side of Mammoth Hollow throughout 

this area, and on the west side north of Hams Fork and 

between Little Muddy and Clear creeks. It outcrops 

west of the great Absaroka fault from the Evanston-Fort 

Bridger road south to Sulphur Creek. 

1 Knight, W. C., Coal fields of southern Uinta County, Wyo.: Geol. 

Soc. America Bull., vol. 13, pp. 542-544, 1902. 

2Veatch, A. C., Geography and geology of a portion of southwestern 

Wyoming: U.S. Geol. Survey Prof. Paper 56, p. 65, l907. 

The stratum that undoubtedly supplied the 

plants collected by Fremont and that was rediscovered by Veatch is about 1,200 feet below 

the top of the Oyster Ridge sandstone. It is 

also below the several minor sandstone ridges 

mentioned by Veatch. The fossiliferous layer 

is a hard, brittle white clay only a few inches 

thick, in the midst of white clay shales, which 

in the exposure near Cumberland are about 30 

feet thick. (See Pl. XXVII.) This almost 

snow-white band of shales is very conspicuous 

and may be traced for miles. The layer containing the plants was found to be fossiliferous 

at nearly every foot of its exposure, and in 

some places it is literally packed with remains, 

especially ferns, which, at least at the Cumberland locality, are the dominant types. This 

great abundance of plants in the bed makes it 

difficult to procure large or perfect specimens. 

AGE OF THE FRONTIER FORMATION. 

As already stated the plant-bearing bed discovered by Fremont and now placed in the 

Frontier formation was tentatively regarded 

by Hall as of Jurassic age, and this reference 

was accepted by Lesquereux, who restudied a 

portion of the original collection in 1888. Long 

before this date, however, the beds had come to 

be recognized as belonging to the Upper Cretaceous. Thus, in 1870, when Hayden 3 gave 

the name Oyster Ridge to the conspicuous 

sandstone ridge near Sulphur Creek, he said: 

"It [Oyster Ridge] is composed mostly of 

gray and yellow-gray sandstone, capped with a 

calcareous sandstone, filled with a small species 

of Ostrea, and belongs, I think, to the upper 

portion of the Cretaceous group-probably No. 

5." This is a virtual reference to the Fox 

Hills sandstone, though that term was not actu- . 

ally employed. 

Later, however, Oyster Ridge was directly 

referred to the Fox Hills by both the Hayden 

and the King surveys, and it is so assigned on 

the map of this region published by the King 

Survey. 

It is difficult to ascertain just when the 

Oyster Ridge sandstone and the associated 

sandstones, shales, and coals of the Frontier 

formation were first regarded as of Colorado 

age. At least as early as 1877 Meek 4 described 

invertebrates that he recognized as of this age, 

a Hayden, F. V., Geology of the Missouri Valley: U. S. Geol. Survey 

Terr., Prel. Rept. for 1870, p. 149, 1871. 

'Meek, F.B., U.S. Geol.Expl.40th Par. Rept., vol.4, pl.1, p.143, 1877. 
76 SHORTER CONTB.IBUTIONS TO GENERAL GEOLOGY, 1917. 

from the vicinity of Sulphur Creek, 3 miles 

west of Oyster Ridge, where they occur in a 

heavy sandstone which is the same as the 

Oyster Ridge sandstone but is in the western 

limb of the syncline. 

This condition was also recognized and 

briefly alluded to in 1892 by Stanton.1 In a 

longer paper published the following year Stanton 2 described a number of the invertebrates 

from the Sulphur Creek area which he r~garded 

as of undoubted Colorado age. 

Although Knight/ when he named the Frontier formation, did not definitely fix its age, he 

took occasion to say that he could "not find a 

Fox Hills fauna such as is common to the Fox 

F~ills of the eastern part of Wyoming" and, at 

least by inference, placed it lower than Fox 

Hills. Veatch 4 also obtained evidence which 

in his opinion strengthened the reference of the 

formation to the Colorado. He also mentions 

the discovery of numerous specimens of Inoceramus exogyroides, an invertebrate held to be 

of Benton age, 3,000 feet above the top of the 

formation, or approximately in the middle of the 

overlying Hilliard formation. Mr. Stanton informs me that he has since procured a distinctly Benton fauna from the same sandstone 

lentil from which Veatch collected, in the Hilliard formation about 3,000 feet above its base. 

Mr. Stanton has been kind enough to supply 

the following account of the invertebrates and 

their occurrence: 

The evidence from the in vertebrate faunas that the 

Frontier formation and the lower half of the Hilliard formation are of the age of the Colorado group was presented by 

Veatch o in 1907. Most of the Frontier invertebrates then 

known came from the upper part of the formation and from 

localities near the Union Pacific Railroad, 20 to 30 miles 

south of Cumberland. They include a number of very 

characteristic Colorado group species, which, in connection 

with the known stratigraphic relations and the fauna of the 

underlying beds, justified the reference of the whole 

Frontier formation, including the plant-bearing bed near 

Cumberland, to the Colorado group. 

Later collections and observations have confirmed and 

strengthened the evidence for the Colorado age of both the 

Frontier formation and the lower 3,000 feet or more of the 

overlying Hilliard formation, and they have a more direct 

bearing on the age of the plant bed because their relations 

to it are definitely determined. The white shales associ1 Stanton, T. W., The stratigraphic position of the Bear River formation: Am. Jour. Sci., 3d ser., vol. 43, p. 105, 1892. 

2 Stanton, T. W., The Colorado formation and its invertebrate fauna: 

U. S. Geol. Survey Bull. 106, 1893. 

3 Knight, W. C., Coal fields of Southern Uinta County, Wyo.: Geol 

Soc. America Bull., vol. 13, p. 543, 1902. · 

4 Veatch, A. C., Geography and geology of a portion of southwestern 

Wyoming: U. S. Geol. Survey Prof. Paper 56, p. 69, 1907. 

6 Veatch, A. c., .op. cit., pp. 66--68, 71, 72. 

ated with the plant bed may be traced along the strike for 

many miles north and south of Cumberland. Tothenorth 

they have been recognized near Glencoe, Oakley, and as 

far as Kemmerer, holding the same position far beneath the 

Kemmerer coal, which is mined at all these places. Two 

collections received from the late Robert Forrester have 

been identified as follows: 

120 feet above· Kemmerer coal, near Oakley, Wyo.: 

Ostrea sp. 

Jnoceramus related to I. deformis Meek. 

Inoceramus sp. 

V eniella goniphora Meek. 

Baculites gracilis Shumard? 

Scaphites ventricosus Meek and Hayden? 

Roof of Kemmerer coal, Glencoe mine, Glencoe, Wyo.: 

Ostrea sp. 

A vicula gastrodes Meek. 

Inoceramus labiatus Schlotheim? 

Nemodon? sp. 

Cardium pauperculum Meek. 

Mactra? sp. 

Corbula sp. 

Melania? sp. 

Scaphites ventricosus Meek and Hayden. 

All the identified forms in these two lots are character:-

istic of the fauna of the Colorado group, and most of them 

in other regions would indicate the upper part of the group, 

but in this western Wyoming area the Upper Cretaceous 

sediments are abnormally thick and many species seem to 

have an unusual vertical range, indicating rapid sedimen-· 

tation. Thus the sandstone lentils near the middle of the 

Hilliard formation about 3 miles northwest of Kemmerer, 

though fully 3,000 feet above the horizon of the two collections last mentioned, still yield a characteristic Colorado 

fauna. Veatch recorded the presence of Inoceramus exogyroides in these lentils and correctly assigned the beds to the 

Colorado group. In 1913 I collected from these sandstones, 

which, according to Veatch, lie from 3,000 to 3,800 feet 

above the base of the Hilliard formation, the following 

species: 

Ostrea soleniscus Meek. 

A vicula gastrodes Meek? 

Inoceramus umbonatus Meek and Hayden. 

Inoceramus exogyroides Meek and Hayden. 

Inoceramus cf. I. undabundus Meek and Hayden. 

Inoceramus fragilis Hall and Meek? 

Cardium pauperculum Meek. 

Cyprimeria? sp. 

Donax oblonga Stanton. 

Tellina? sp. 

Mactra emmonsi Meek. 

Mactra sp. 

Martesia? sp. 

Pugnellus fusiformis (Meek). 

Placenticeras sp. cf. P. pseudoplacenta Hyatt. 

None of the species in this list is known to range above 

the Colorado group. The first two species of Inoceramus are 

especially abundant and are characteristic of a horizon 

near the top of the Colorado not far below the Eagle sandstone on Missouri River below Fort Benton, Mont. The 

Donax and the Pugnellus are equally characteristic of a 

sandstone in the Colorado group above the principal coal 

bed at Coalville, Utah. 
A FOSSIL FLORA FROM THE FRONTIER FORMATION OF SOUTHWESTERN WYOMING. 77 

The evidence of the plants as to the age of the 

beds containing them was first believed to be in 

substantial accord with that of the invertebrates. In my report 1 on the plants collected 

by Veatch I made the following statement regarding their position: "The age, so far as I am 

able to fix it, is the lower part of the Upper Cretaceous, about the position of the Turonian, 

possibly a little lower." 

The Colorado age of the Frontier formation, 

as based on stratigraphie position and the evidence of the invertebrates, is here accepted. It 

is but fair to state, however, that the critical 

study of the plants does not lend conclusive 

support to their reference to the Colorado. Inasmuch as practically all the forms are new to 

science, the interpretation of their bearing on 

the question of age must be made through 

their affinities, and these, so far as they can be 

made out, appear to favor a position stratigraphically higher than the Colorado. This 

evidence may be briefly reviewed as follows: 

The spleenwort (Asplenium occidentale) belongs to the same group as and is pretty closely 

related to an unpublished species from the 

Farmington sandstone member of the Kirt-

. land shale (Montana group) of San Juan 

County, N. Mex. The shield fern (Dryopteris 

coloradensis) is strongly suggestive of an unpublished species from the Vermejo formation 

of the Raton Mesa region of Colorado and New 

Mexico. The Anemia is very closely related to 

and perhaps identical with a species common in 

the Eocene of Europe but also reported from the 

Montana at Point of Rocks, Wyo. Among the 

dicotyledons, Oinnamomum hesperium is hardly 

distinguishable, except in size, from Oinnamomum wardii, from the upper part of the Adaville formation at Hodges Pass, a few miles 

north of the Cumberland localities. Dewalquea 

pulchella and Dryandroides lanceolata are so 

close to Dewalquea insignis and Dryandroides 

quercinea, respectively, from the Upper Senonian of Westphalia, that it is perhaps doubtful 

if they should be maintained as distinct. 

Quercus stantoni is very similar to Quercus 

formosa, also from the Senonian of Westphalia. 

Ficus fremonti agrees in shape with Ficus 

proteoides Lesquereux, and in shape, size, and 

nervation with Ficus lanceolata acuminata 

Ettingshausen, as figured by Lesquereux, from 

I Knowlton, F. H.,in Veatch, A. C., Age and type localities of supposed 

Jurassic fossils collected north of Fort Bridger, Wyo., by Fremont in 1843: 

Am. Jour. Sci., 4th ser., vol. 21, p. 459, 1906. 

the Dakota sandstone. This is the only species 

that appears to show any special like,ness to 

forms from beds whose position is lower than 

that assigned to the plant beds at Cumberland. 

The foregoing is not the only evidence for 

assigning the Frontier formation to a position 

higher than the Colorado, though ~he additional 

evidence is not so strong as it was supposed at 

one time to be. In 1907 A. R. Schultz, of the 

United States Geo1ogical Survey, began an 

investigation of the coal resources of the socalled Rock Springs dome, about 75 miles east 

of the Cumberland area. Incidentally to this 

study Schultz procured a number of very interesting collections of fossil plants, mainly from 

thin, indurated clay partings in coal. The age 

of these plants has been fixed as near the middle 

of the Mesaverde formation (Montana group), 

in what has been called the Rock Springs coal 

group. The most abundant plants are ferns of 

the genera Gleichenia and Anemia, and the 

dicotyledons are comparatively few. This 

flora has a facies strikingly similar to that of 

the flora from the Frontier formation, and as 

several species appeared to be in common, I 

held that the plant-bearing beds at Cumberland 

and Rock Springs were identical in age. A 

critical study of the Frontier flora, however, 

discloses the fact that there are apparently no 

dicotyledons and few if any ferns common to 

the two areas. 

GENERAL FEATURES OF THE FLORA. 

SPECIES NOW RECOGNIZED. 

Before proceeding to a discussion of the 

various aspects of this flora, it will be of interest 

to present the following complete list of the 

forms now recognized: 

Tapeinidium? undulatum (Hall) n. comb~ 

Microtaenia variabilis n. gen. and n. sp. 

Microtaenia paucifolia (Hall) n. comb. 

Dennstaedtia? fremonti (Hall) n. comb. 

Dryopteris coloradensis n. sp. 

Asplenium occidentale n. sp. 

Anemia fremonti n. sp. 

Equisetum sp. 

Smilax? coloradensis n. sp. 

Myrica nervosa n. sp. 

Salix cumberlandensis n. sp. 

Salix frontierensis n. sp. 

Quercus stantoni n. sp. 

Ficus fremonti n. sp. 

Ficus? sp. 

Ficus? sp. 

Cinnamomum hesperlum n. sp. 

Cinnamomum? sp. 
78 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

Dryandroides lanceolata n. sp. 

Aralia veatchi.i n. sp. 

Staphylea? fremonti n. sp. 

Dewalquea pulchella n. sp. 

Phyllites fic.ifolia n. sp. 

Phyllites dentata n. sp. · 

Phyllites. 

LOCALITIES AND COLLECTORS. 

I. Probably on the south bank of Little 

Muddy Creek about l mile east of the present 

town of Cumberland, Wyo. Collected by J. C. 

Fremont August I9, I843. Below is a list of 

the species described by Hall with their present 

disposition: 

Sphenopteris fremonti Hall=Dennstaedtia? fremonti. 

Sphenopteris triloba Hall=Microtaenia paucifolia. 

Sphenopteris? paucifolia Hall=Microtaenia paucifolia. 

Sphenopteris? trifoliata Hall. 

Glossopteris phillipsi?=Ficus fremonti. 

Pecopteris undulata Hall=.Tapeinidium? undulatum. 

Pecopteris undulata var.=Tapeinidium? undulatum. 

Pecopteris? odontopteroides Hall=Tapeinidium? undulatum. 

Trichopteris filamentosa Hall=rootlets of ferns. 

Trichopteris gracilis Hall=rootlets of ferns. 

Leaf of dicotyledonous plant?=Phyllites fremonti Unger. 1 

2. North branch of Little Muddy Creek I mile 

east of Cumberland, Wyo. Collected by A. C. 

Veatch August 3, I906. 

Tapeinidium? undulatum. 

Dryopteris coloradens.is. 

Equisetum sp. 

Aralia veatchii. 

Dewalquea pulchella. 

3. Approximately same locality as No. 2. 

Collected byT. W. Stanton and F. H. Knowlton 

August 5, I908. 

Tapeinidiutn? undulatuill. 

Microtaenia variabilis. 

Microtaenia paucifolia. 

Dennstaedtia? fremonti. 

Asplenium occidentale. 

Anemia fremonti. 

Ficus fremonti. 

Staphylea? fremonti. 

Phyllites ficifolia. 

Insect mine in leaflet of Staphylea. 

4. Mine No. I, Cumberland, Wyo. Collected 

by F. H. Knowlton August 6, I908. 

Smilax? coloradensis. 

l This is apparently not from the Frontier formation but probably 

from the Green River formation 40 or 50 miles east of the Cumberland 

locality. (Seep. 94.) 

5. About half a mile east of Cumberland, 

Wyo. Collected by T. W. Stanton and F. H. 

Knowlton August 5, I908. 

Ficus? sp. 

Ficus? sp. 

Cinnamomum? sp. 

6. About I mile east of Cumberland, Wyo. 

Same horizon as principal Cumberland locality 

but at a slightly different point. Collected by 

A. C. Peale August I8, I909. 

Ficus fremonti. 

Aralia veatchi.i. 

7. About It miles south of Cumberland, 

Wyo., in theSE. i sec. 6, T. I8 N., R. II6 W. 

Same horizon as locality I mile east of Cumberland, and probably near the original Fremont 

locality. Collected by T. W. Stanton September I, I9I3. · 

Tapeinidium? undulatum. 

Myrica nervosa. 

Salix cum berlandensis; 

Salix. 

Quercus stantoni. 

Ficus fremonti. 

Cinnamomum hesperium. 

· Dryandroides lanceolatum. 

Phyllites dentata. 

Phyllites. 

8. About I mile east of Oakley and 3 miles 

southeast of Kemmerer, Wyo., in the SW. i 

sec. 3, T. 2I N., R. II5 W. Collected by T. W. 

Stanton September 2, I9I3. 

Ficus fremonti .. 

Quercus stantoni. 

Fragments of dicotyledons, not determinable. 

BIOLOGIC ASPECTS OF THE FLORA. 

The known flor~ from the Frontier formation near Cumberland embraces 25 forms, of 

which 7 are ferns, I an Equisetum; I a monocotyledon (Smilax), and the remaining I6 

dicotyledons. As regards the relative abundance of the different types,' it is probable that 

the ferns outnumber the other forms by perhaps 

two to one. Several of the dicotyledons are 

based on single specimens, but there is hardly 

a piece of matrix without fragments of ferns. · 

The first four species of ferns enumerated 

in the list on page 77 possess great biologic 

interest. They form a natural group that, 

from their peculiar and well-marked type of 
A FOSSIL FLORA FROM THE FRONTIER FORMATION OF SOUTHWESTERN WYOMING. 79 

fructification, marks them as being undoubtedly davallioid-that is, clearly allied to the 

group of mainly tropical ferns of whi~h the 

genus Davallia is the central form. They are 

entirely unlike anything now living in the 

New World and appear to find their closest 

relatives among species now living in Polynesia. Thus the Tapeinidium, although far 

from being conspecific with any living form of 

the genus, appears to be most closely related to 

Tapeinidium pinnatum ( Ca vanilles) C. Christensen, a species widely dispersed in Malaysia and 

Polynesia. The two species called Microtaenia 

are so wholly unlike any living or fossil form 

known that it has been necessary to create a 

new genus for their reception. They are very 

abundant in individuals, showing that they 

formed a well-established element in the 

Frontier flora. The species referred to Dennstaedtia is not so well established as either of 

the first three forn1s in the list and is based on a 

few fragments that may possibly represent an 

extreme modification of Microtaenia paucifolia. The genus Dennstaedtia is a large 

group comprising more than 60 species. They 

are of wide, mainly tropical distribution, only 

one species (D. punctilobula), the so-called hayscented fern, inhabiting North America; this 

species is quite unlike the fossil form under 

discussion. 

The single species of shield fern (Dryopteris) is of an ordinary type, but the spleenwort (Asplenium occidentale) belongs in the 

group of living species of which A. hemitonites 

Linne is the type. Anemia is also a large 

genus of almost exclusively tropical American 

forms, only two inhabiting the United Statesone in peninsular Florida, the other in southern Texas and extending into adjacent parts 

of Mexico. 

The horse-tail (Equisetum sp.) is so poorly 

represented that it has little value beyond 

indicating the presence of this type of vegetation. 

The smilax, the only form referred to the 

monocotyledons, is based on a single specimen 

and is of doubtful biologic value. 

The dicotyledons are represented by a number of well-known types. They include a 

coriaceous-leaved waxberry (Myrica), two 

willows (Salix), and a small-leaved oak (Quercus), all of which are very modern in appearance. The named species of fig (Ficus fre816380-17-2 

monti) is so placed on account of its general 

resemblance to and affinity with certain described fossil species, and not on account of its 

relationship with living members of the genus. 

Ficus is a vast, mainly tropical group comprising over 600 species. The named form referred to Cinnamomum, the well-known cinnamon tree, is of the type of an unidentified 

living species from China. The genus is not 

now a native of the New World, its center of 

distribution being tropical and subtropical 

portions of southeastern Asia. The species of 

Dryandroides, if correctly placed, is of importance as showing the presence of the 

Proteaceae in this country during early Upper 

Cretaceous time, but it is so fragmentary 

that I can not be certain of its position. 

PHYSICAL AND CLIMATIC CONDITIONS 

INDICATED. 

From the facts now available it appears unquestionable that at least the major portion 

of the Frontier formation was laid down in 

fresh water. This is proved by the numerous, 

thick, and widespread beds of coal it contains. 

The coal swamps of that epoch, which must 

have been of wide extent and long duration, 

might well have been and doubtless were but 

little above sea level, for sandstones containing oysters occur both below and above certain of the coal beds, showing slight oscillation that permitted the access of at least 

brackish water. No strictly marine organisms 

are known. About 1,000 feet below the top of 

the formation there are several thick beds of 

unios which indicate that the water at that 

time was fresh. There is nothing in the flora 

to indicate that any of its members required 

or indeed could tolerate a saline habitat; on the 

contrary, they could have found a congenial 

home only in or near fresh-water swamps and 

forests. 

The climate during Frontier time appears to 

have been tropical or subtropical, as is shown 

in a number of ways. Thus, one of the most 

abundant of the ferns (Tapeinidium) was indeterminate in growth, a condition that could 

survive to the extent here indicated only in 

the absence of frosts. The most abundant 

elements in this flora are the ferns, and of these 

the davallioid forms (Tapeinidium, Mic1·otaenia, and Dennstaedtia), to which may be 

added the Anemia, all call for a tropical or 
80 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY,. 1917. 

subtropical habitat. The spleenwort (Aspleniu~), if its affinity has been correctly interpreted, likewise calls for at least a subtropical 

setting, as do~s the single shield fern (Dryopteris). . The smilax is too incompletely known 

to permit a generalization concerning its climatic environment, though it must have been 

as warm as warm temperate and might well 

enough have been still warmer. The waxberry (Myrica), the oak (Quercus), and the 

willows (Salix), on the other hand, might not 

be out of place in a temperate region, but the 

figs (Ficus) and the cinnamon trees ( Cinnamomum) certainly required a tropical or subtropicalloca tion. 

EVIDENCE OF INSECTS IN FRONTIER TIME. 

An interesting though very meager fragment of information concerning the insect ]jfe 

of Frontier time has resulted from this study. 

Evidence of the presence of insects was noted 

on two leaves. One of these leaves (see Pl. 

XXXV, fig. 5), now named Ficusjremonti, was 

found by Frenwnt and is fortunately one of 

those in the collection of the United States 

National Museum. This specimen was figured 

by Hall, 1 who noted the presence of a cluster 

of circular bodies on one side of the leaf. He 

was uncertain as to the nature of these bodies, 

and as he had referred the leaf to Glossopteris 

phillipsi, a fern, he suggested that they might 

possibly represent the fruiting stage, though 

he adds: "This structure is so partial that iy 

can only with doubt be referred to the fructification of the plant; and it is not improbable 

that the same n1ay be some parasitic body or 

the eggs of an insect which have been deposited 

upon the leaf." This specimen was shown to 

Dr. August Busck, of the Bureau of Entomology, who at once recognized these circular 

bodies as an undoubted insect egg mass, probably of a microlepidopterous insect. 

The other specimen, shown in Plate XXXIII, 

figure 5, is a leaflet of Staphylea? fremonti 

in which ·a symmetrically looping mine has 

been made in the leaf substance by an insect 

larva. This Dr. Busck pronounced also to be 

the work of a microlepidopter, possibly belonging to the genus Phylloenistis. The mine 

appears to increase slig~tly in size from the 

apex of the leaflet toward the base, the exit 

being the basal margin next to the n1idrib. 

The work of this Frontier insect is absolutely 

similar in character to that of forms now living, 

a fact which would seem to indicate that the 

habits of life have persisted with no observable 

change from middle Cretaceous time to the 

present. THE FLORA. 

Family POLYPODIACEAE. 2 

Tapeinidium? undulaturn (Hall) Knowlton, n. comb. 

Plate XXVIII, figures 1-4. 

Pecopteris undulata Hall, in Fremont, Report of the 

exploring expedition to the Rocky Mountains in 

1842, etc., Appendix B, p. 306, pl. 1, figs. la, 1b, 

1845. -

Pecopteris undulata Hall, var., idem, p. 306, pl. 1, figs. 

2, 2a, 2b. 

Pecopteris? odontopteroides Hall, i~em, p. 306, pl. 1, figs. 

3, 4. 

Outline and habit of whole frond not known 

but·presumed to be simply pinnate, lanceolate 

in outline, gradually narrowed to the apex 

(base not seen); rachis strong, ridged, in places 

slightly winged; pinnae numerous, at right 

angles to the rachis, sessile, linear in general 

outline, sharp-pointed at apex, cut in v;arying 

degree into numerous rounded, slightly oblique 

or fan-shaped lobes which are entire or slightly 

erose-dentate; the lobes decrease in size apjcally, becoming merely undulations, the tip 

being almost or quite entire; upper , pinnae 

reduced in size, with undulate or almost entire 

margins; nervation of pinnae eonsisting of ll, 

very strong, grooved midvein, the lobes provided with a thin, delicate midvein and usually 

about three pairs of once-forked veins. 

This species is exceedingly abundant, probably the most abundant plant found in these beds, 

as there is hardly a pieee of matrix that does no't 

contain a fragment. In spite of its abundance, 

however, it is very rarely that specimens of 

considerable size and completeness are procured. It was apparently very brittle and 

easily broken up before it was entombed. The 

most complete example thus far found is that 

shown in figure 3, which has a preserved length 

of 12 centimeters but was undoubtedly considerably longer than this when perfect. The 

2 In the study of the ferns, especially the first four species, I have had 

1 Hall, James, in Fremont, J. c., Report of the exploring expedition the benefit of the assistance and critical judgment of Mr. W • R. Maxon, 

to the Roc:Ky Mountains in the year 1842, and to Oregon and North of the United States National Museum. My thanks are due to Mr. 

California in the years 1843-44~ Twenty-eighth Cong., 2d sess., House Maxon for detecting and pointing out affinities and interrelationships 

Executive Doc. 166, pl. 2, figs. 5b, 5c, 1845. that would otherwise have been overlooked. 
A FOSSIL FLORA FROM THE FRONTIER FORMATION OF SOUT'HWEST'ER.N WYOMING. 81 

width, of course, varies according to the position in the frond, the ma.ximum width being 

6 or 8 centimeters. In the upper pa.rt of the 

frond the pinnae a.re continuous, but in the 

middle a.nd lower pa.rts some of them a.re 

sepa.ra.ted by a. distance of once or twice their 

width. 

An interesting feature connected with the 

manner of growth in this fern is tha.t it a.ppea.rs 

to be indeterminate in growth-that is, the 

a.pica.l bud continued active a.nd the frond continued to grow indefinitely. This is a. condition not unknown a.mong living ferns, though 

its recorded occurrences a.re not numerous. It 

is presumed to occur, a.t lea.st to a. noticeable 

degree, only in ferns ~f a. tropical habitat, 

where absence of frost would permit the· delicate growing tip to survive. 

It has been difficult to place this fern biologically, a.nd for information a.nd advice concerning its position I am greatly indebted to 

Mr. W. R. Maxon, of the United States N ationa! Museum. It has, at lea.st superficially, 

some features of resemblance to Gleichenia, 

such as the size and shape of the pinnae and 

the thin right-angled insertion on the rachis, 

but on closer inspection it is seen that the lobes 

or segments of the pinnae are really oblique or 

somewhat unequal-sided. The · forked veins 

also exclude the present form from Gleichenia. 

In . habit this form somewhat approaches 

certain species of Dryopteris, but, all things considered, its characteristic features appear to be 

davallioid and to approach most closely those 

of Tapeinidium, a small genus of fern species 

of pinnate form, mainly natives of the Polynesian Islands. 

Although Hall described this fern under two 

specific names and one varietal name, the distinctions are based mainly on size a.nd it is not 

believed tha.t they can be ma.inta.ined. Thus 

the type of his Pecopteris undulata (his Pl. I, 

fig. 1a) is evidently a. segment from the middle 

part of a. large frond, where the pinnae are 

s.eparated by a considerable interval, as shown 

in Pla.te XXVIII, figures 1 and 4. Hall's Pecopteris? odontopteroides (his Pl. I, figs. 3, 4) is based 

on small pinnae with ·undulate or slightly cut 

margins that can be duplicated in the upper portion of the frond shown in Plate XXVIII, figure 

3. The form described by Hall as a. variety of 

Pecopteris undulata (his Pl. I, fig. 2) is also a segment from the middle or lower pa.rt of a. very 

large frond, and the pinnae, although broader 

than a.ny others noted, are not cut so deeply by 

the lobes a.s many smaller ones. If it has been 

correctly drawn, however, it appears to be 

slightly different from the normal forms, but 

even so it is hardly entitled to separate recognition. The other specimens referred to this 

variety (Hall's Pl. I, figs. 2a., 2b) are clearly 

segments with nearly entire pinnae from nea.r 

the apex of a frond of the normal type. 

The nervation of the pinnules shown by Hall 

in his Plate I, figures 1 b and 2a., is incorrect, 

as the lateral nerves are shown as simple a.nd 

unforked, although he describes the veins in 

the text a.s forking. As may be seen from the 

enlargement shown in figure 2a, the nervation 

consists of a thin, delicate midvein a.nd two or 

three pa.irs of once-forking veins. 

The only specimen of the original Fremont 

collection known to be extant is one of the 

types of Pecopteris? odontopteroides, figured by 

Hall in his Plate I, figure 4. It is No. 30848 

of the United States N ationa.l Museum collections. 

Occurrence: Frontier formation, about 1 n1ile 

ea.st of Cumberland, Wyo. Collected originally 

by J. C. Fremont August 19, 1843. Subsequently collected by A. C. Veatch in 1906 a.nd 

by F. H. Knowlton and T. W. Stanton in ~908. 

Genus MICROTAENJA 1 Knowlton, n. gen. 

Small davallioid,· pinnate herbaceous ferns, 

with close, linear, acute pinnules; lower pinnules barren, entire or slightly crenulate-margined; middle pinnules incompletely fertile; 

upper ones more completely or wholly fertile, 

reduced, becoming undulate, then cut nearly 

to the mid vein into sharp-pointed lobes; sori 

large, terminal, somewhat elongate, occupying 

the whole of the tips of the lobes. 

Type, Microtaenia 'variabilis. 

Microtaenia variabilis Knowlton, n. sp. 

Plate XXIX, figures l-4a. 

Size a.nd shape of whole frond unknown but 

apparently at least bipinna.te, the divis~ons 

(frond?) lanceolate in outline, narrowed at ba.se, 

acutish a.t apex; rachis slender, distinctly sulcate; segments or pinnules numerous, approximately a.t right angles to the rachis, close to 

1 From JL•Kpos, small, and T<nv.a, Latin taenia, a ribbon, in allusion to 

the narrow, ribbon-like pinnules. 
82 SHORTER CONT'RTBUTIONS TO GENERAL GEOLOGY, 1917. 

distant, linear and grasslike in shape, slenderly 

acuminate at apex, truncate or very slightly 

heart-shaped or halberd-shaped at base, closely 

sessile; lower barren pinnae entire or very 

slightly . undulate; middle · pinnules incompletely fertile, the fertile portion reduced, cut 

nearly to the midvein into sharp-pointed lobes; 

sori terminal or elongate, occupying nearly the 

whole outer part of the lobe; nervation of pinnules obscure, consisting of a very strong, 

sulcate midvein and apparently delicate, onceforked lateral veins which are at a low, almost 

right angle with the midvein. 

This very strongly marked type is represented by a large number of specimens, some of 

which, it will be seen, are exceptionally well 

preserved. In spite of the profusion of specimens, however, none are so complete as to give 

incontestable evidence as to the size and shape 

of the whole frond, though it appears to have 

been at least bipinnate. The two largest segments preserved, shown in figures 1 and 2, are 

from th,e lowest portion- of the frond, but 

neither quite reaches the base. They are narrowly lanceolate in outline, narrowing below 

to their point of attach:nient. Another specimen not figured shows that the apex also narrows and becomes acutish. The largest of the 

segments has a preserved length of 10 centimeters and a maximum width of about 4 

centimeters. Its full length was probably not 

less than 15 or 18 centimeters. 

The pinnules are all approximately at right 

angles to the rachis. In the specimen shown 

in figure 2, which must be very near the base of 

the frond, the pinnules are close together, but 

in the upper portion they become more distant, 

and in the specimen shown in figure 1 they are 

separated by more than the width of the pinnules. In other specimens, such as those shown 

on the left of figure 2 and in figure 4, the pinnules are separated by two or three times their 

width. The pinnules clearly are more distant 

in the middle and upper portions, where the 

frond is becoming fertile. 

Most of the barren pinnules are entire or 

nearly so, as shown, for instance, in figure I, 

but· a tendency to variation is constantly manifest. Thus, in figure 2, which to all intents and 

purposes is about the same as figure I, the 

pinnules show a decided tendency to be undulate margined and some of them to become distinctly lobed near the tips. In the fragmentary 

specimen on the left of the stone shown in 

figure 2 the exceedingly long, narrow pinnule 

is lobed up to the point where it becomes 

fertile, as are the other, broken pinnules, 

though the undulate lobed to strongly cut 

fertile portions are well shown in figure 3. 

None of these pinnules is completely fertile, 

each having a short barren, undulate-lobed 

portion near the base. In the specimen shown 

in figure 4a the whole of the pinnule has become fertile. 

The sori are perhaps best shown in figure 3. 

They are seen to be terminal and somewhat 

elongate and to occupy the whole of the tips of 

the lobes. 

The relationships of this fern are not easy to 

determine. That it is extremely variable in a 

number of particulars has been brought out in 

the above discussion. In certain specimens in 

which the barren pinnules are more or less 

undulate lobed this species appears to approach 

what is here called Tapeinidium? undulatum. 

Some specimens of that species have pinnules 

only slightly lobed and are almost impossible 

to distinguish from the present form. The 

character of the mid vein is exactly t~e same in 

both forms-that is, it is strong and deeply 

sulcate, thus producing the appearance of two 

lines when seen from the upper side of the 

pinnule. 

So far as can be learned by study of the 

figures given by Hall and such of the original 

material as is now accessible, Fremont did not 

collect specimens of Microtaenia variabilis unless the fertile upper portion of Hall's Sphenopteris triloba (his Pl. II, fig. 2) is an isolated 

fragment of a pinnule. 

Occurrence: Frontier formation, 1! miles 

east of Cumberland, Wyo. Collected by F. H. 

Knowlton and T. W. Stanton August 5, 1908. 

Microtaenia paucifolia (Hall) Knowlton, n. comb. 

Plate XXX, figures 1, 2. 

Sphenopteris? paucijolia Hall, in Fremont, op. cit., Ar- pendix B, p. 304, pl. 2, figs. 1, la, b, c, d . . 

Sphenopteris? trijoliata Hall, idem, pl. 2, fig. 2. 

Similar in general effect to the type species 

but evidently more finely divided, probably 

tripinnatified, the rachis much more slender; 

complete barren pinnules not seen; basal barren 

portion of fertile pinnules strongly undUlate 
A FOSSIL FLORA FROM: THE FRONTIER FORMATION OF SOUTHWESTERN WYOMING. 83 

lobed; fertile pinnules very short, with only 

two or three lobes on each side; sori terminal, 

occupying the whole of the tip. 

There is more or less uncertainty regarding 

the status of this form. It is represented by 

only four or five very fragmentary specimens, 

all of which show the fertile pinnules but give 

very little evidence regarding the barren portions. In the first place, it appears to be more 

finely divided than M. variabilis, as shown in 

one of Hall's figures (his .Pl. II, fig. 1) of S phenopteris? paucijolia, though none of the recent 

specimens is sufficiently complete to show this 

feature. The specimen shown in Hall's figure 

is certainly tripinnatified, with the pinnules 

short and very much reduced. 

The only evidence regarding the character of 

the barren pinnules is shown in figure 2, where 

the basal portions of three or four of the lower 

pinnules are seen to be undulate lobed before 

they pass into the deeply lobed, fertile portion. 

The specimen named Sphenopteris triloba by 

Hall is probably only a smaller and more 

reduced state of S. paucijolia in which the 

fertile lobes are reduced to three. It may be 

that the pinnules are broken at the tips, but 

as the specimen is not now known to be extant, 

it is impossible to settle this point. 

In the upper portion of Hall's figure 2 he 

shows the axis apparently passing into a 

fertile portion (enlarged in his fig. 2d), but this 

portion is only accidentally in that position and 

has no organic connection with the rest of 

the specimen. It appears to be an isolated 

fragment of a fertile pinnule of Jl!. variabilis. 

Occurrence: Frontier formation, 1! miles 

east of Cumberland, Wyo. Collected by F. I-I. 

Knowlton and T. W. Stanton August 5, 1908. 

Dennstaedtia? frernonti (Hall) Knowlton, u. comb. 

Plate XXX, figure _5; Plate XXXI, figure 1. 

Sphenopterisjremonti Hall, in Fremont, op. cit., Appendix 

B, p. 304, pl. 2, figs. 3, 3a. 

Size and shape of whole frond unknown but 

probably at least tripinnate or tripinnatified; 

main rachis exceedingly strong, ridged; pinnae 

approximately at right angles to the rachis, 

linear or lanceolate, with the secondary rachis 

sulcate; pinnules rather remote, subovate, 

somewhat decurrent at base, about three or 

four lobed; sori large, terminal on the tips of 

the lobes. 

This form is represented by so few and so 

fragmentary specimens that it must stand as 

insufficiently characterized. The most important features that can be made out are the 

exceedingly thick main rachis; small, fewlobed pinnules; and rather large, terminal sori. 

As regards the probable affinity of this form 

the best that can be said is that it is undoubtedly a davallioid fern, which as a matter of 

convenience is tentatively referred to the genus 

Dennstaedtia. 

Occurrence: Frontier formation, about 1 mile 

east of Cumberland, Wyo. Collected by J. C. 

Fremont August 19, 1843, and by F. H. 

Knowlton and T. W. Stanton August 5, 1908. 

Dryopteris coloradensis Knowlton, n. sp. 

Plate XXX, figures 3, 4. 

Outline of whole frond not known but evidently of large size and at least bipinnatified; 

rachis strong, round; pinnules at an angle of 

about 30°, alternate, rather remote, linearlanceolate, acuminate at apex, broadest at base, 

sessile, cut more than half the distance to the 

secondary rachis into numerous close, slightly 

scythe-shaped, obtusely pointed, or somewhat 

acute lobes; small upper lobes entire, larger 

lobes uneven or in places sharply serrate; 

secondary rachis slender; nervation of the lobes 

consisting of a thin, slightly flexuose midvein 

and five or six pairs of delicate, once-forked 

veins, the fork occurring just above the midvein; fructification not seen. 

This form is represented by several pieces, 

two of the most complete of which are figured. 

From the presence of large pieces of stems 

intermingled with the fronds and presumed to 

belong with them, it is assumed that this fern 

was probably of large size, but the direct 

evidence is only sufficient to say that it is at 

least bipinnatified. Under the circumstances 

measurements are of comparatively little value, 

though it may be stated that the pinnules 

range from 5 or 6 to 10 centimeters or more in 

length and from 8 to 18 millimeters in width. 

Occurrence: Frontier formation, about 1 mile 

east of Cumberland, Wyo. , Collected by A. C. 

Veatch in 1906. 
84 SHORTER CONT~IBUTIONS TO GENERAL GEOLOGY, 1917. 

Asplenium occidentale Knowlton, n. sp. 

Plate XXXI, figures 2-5. 

Although this form is represented by a large 

number of specimens, they are all so fragmentary and disconnected that it is impossible 

to gain an adequate conception of the frond as 

a whole. Under the circumstances it seems 

best simply to figure a number of the bestpreserved fragments and describe them as fully 

as possible, but to leave to the future its 

definite allocation. It was evidently a fern 

of considerable size, as may be seen from the 

example shown in figure 4. This has a preserved length of 7 centimeters and a width of 

3.5 centimeters but was probably considerably 

larger. The margin is undulate-lobed and has 

a few fine, sharp teeth. The apex in other 

specimens is shown to be strongly toothed. 

The nervation consists of a very stout midvem 

and strong veins that arise at an angle of 

probably 40° but curve outward until they are 

nearly at right angles to the midvein. The 

veins fork usually very close to the midvein 

and once or twice above. 

The specimen shown in figure 2 consists of 

two pinnules attached to a minute piece of 

the rachis. Each is rounded on the lower side, 

so that they produce together a deeply heartshaped base. The tip of the left-hand pinnule 

shows the strong teeth above mentioned. 

. In figure 5 two examples are shown; the 

lower is about the size of the one last described, 

the upper much smaller. The margin of the 

upper one is strongly undulate-toothed, becoming in the upright segment almost lobed. 

The nervation is of the same character as that 

in the large· example (fig. 4), described above, 

except that there is usually only one fork in 

the nerves and this is near the midvein. 

On account of the uncertainty attending 

the assignment of this form it is G>bviously unwise to attempt comparisons with either living 

or fossil species. It is placed in the genus 

Asplenium on the ground of its resemblancefancied or real-to the living Asplenium hemionites Linne, but more complete material will 

·be necessary before its status can be fixed. It 

is believed, however, that enough of it is here 

described and figured to permit its subsequent 

recognition, not only in the Frontier formation 

but elsewhere. 

Occurrence: Frontier formation, 1 mile east 

of Cumberland, Wyo. Collected by F. H. 

Knowlton and T. W. Stanton in 1908. 

, Family SCHIZAEACEAE. 

Anemia fremonti Knowlton, n. sp. 

Plate XXXI, figure 6; Plate XXXII, figures 1-3. 

Outline of whole front not known; stipe 

long, slender, dichotomous; frond bipinnate, 

possibly tripinnate; pinnae narrowly deltoid; 

pinnules arising at an acute angle, linear-lanceolate, sessile and decurrent or lower ones nearly 

free; pinnules cut, especially near the base, . 

into deep, sharp-toothed, entire, forwardpointing lobes, which decrease ap~cally so that 

the terminal fourth is entire or merely crenulate; middle and upper pinnules becoming 

more and more entire toward the apex, which 

is only crenulate; nervation rather sparse, at a 

very acute angle, nerves once or twice forked; 

fertile frond not found. 

This species is represented by a large number 

of specimens, but unfortunately all are so fragmentary that it is impossible to make out the 

shape and size of the whole frond. Some evidence to show that the frond was very large 

and several times compounded is afforded by 

the presence of certain fragments disposed in 

such a way on the matrix as to suggest the 

possibility of their organic connection, but no 

such union has been seen. A dichotomous 

branching of the slender rachis, such as is 

shown in figure 3, is all the branching that has 

been observed. The longest segment of rachis 

observed (fig. 3) is 6 centimeters long but was 

certainly considerably longer when perfect. 

The best-preserved pinna, shown in figure 1, is 

14 centimeters long, of which ~t least 2 centimeters is made up of secondary rachis. It is 

approximately 6 centimeters broad between the 

tips of the lower pinnules. The manner and 

extent of the marginal cutting of the pinnules 

is so well shown in the figure that it is not necessary to describe them at greater length. 

This species is exceedingly close to Anemia 

subcretacea (Saporta) Gardner and Ettingshausen/ a species that was described from 

~5pecimens obtained in the Eocene travertines · 

of Sezanne and was subsequently found to be 

abundant in the Eocene of Bournemouth, England. The present form appears to differ 

slightly in its broader pinnae, generally less 

sharply cut pinnules, and more erect nervation, but at best the difference is not great. 

Gardner and Ettingshausen referred Lesquereux's Gymnogramma haydenii,2 from the divide 

1 Gardner, J. S., and Ettingshausen, Constantin von, Monograph of 

the British Eocene flora, vol. 7, p. 45, pls. 8, 9, 1880. 

11 U.S. Geol. Survey Terr. Rept., vol. 7, p. 5·9, pl. 5, figs. 1-3, 1878. 
A FOSSIL FLORA FROM THE FR.ONTIER FOR.MATION OF SOUTHWESTERN WYOMING; 85 

between the headwaters of Snake River and 

Yellowstone Lake, to their Anemia subcretacea, 

and in this reference Lesquereux concurred. 

The specimen shown in figl{re 3 of Lesquereux's 

plate is considerably like the specimens from 

Cumberland, but those shown in the other fig~ 

ures are quite different. 

At one time Newberry was of the opinion 

that he had found Anemia subcretacea at a 

number of localities, as Point of Rocks, Wyo. 

(Montana), Erie, Colo. (Laramie), and Bellingham Bay and Carbonado, Wash. (Eocene), but 

in his formal report 1 he inclined to regard them 

as representing a well-marked, robust variety. 

This work was edited by Hollick, who substituted the name Anemia perplexa for the reason 

that A. subcretacea was considered nomenclatorially untenable. The specimens figured 

by Newberry are very unlike the present 

species, and furthermore, it would seem to be 

wise not to regard them as identical with the 

European form. 

A fine large species of Anemia from the 

Raton formation of Colorado is described by 

me in a paper now in press/ but it is quite 

different from Anemia gracillinea. 

Fragmentary specimens of Anemia have 

been found at many localities in the Rocky 

Mountain region, ranging in age from early 

Montana to Laramie, but none of them appear 

to agree very closely with the present species. 

Occurrence: Frontier formation, 1 mile east 

of Cumberland, Wyo. Collected by F. H. 

Knowlton and T. W. Stanton in 1908. 

Family EQUISETACElE. 

Equisetum sp. 

Plate XXXIII, figure 6. 

The collection made near Cumberland by 

Veatch contains a single specimen with its 

counterpart that apparently represents the 

underground stem of an Eq_uisetum. It is 

about 9 centimeters long, has a maximum 

diameter of nearly 1 centimeter, and is more or 

less constricted or cut up into short segments 

10 to 15 millimeters in length. It is irregularly 

ridged or wrinkled longitudinally but otherwise 

has no marks or features of diagnostic value. 

I Newberry, J. S., The later extinct floras of North America: U. S 

Geol. Survey Mon. 25, p. 4, 1898. 

2 Lee, W. T., and Knowlton, F. H., Geology and paleontology of the 

Raton Mesa and other regions in Colorado and New Mexico: U. S. 

Geol. Survey Prof. Paper 101, p. 285, pl. 54, fig. 2 (in press) . 

• 

Beyond the fact of attesting the presence of 

vegetation of this type in the Frontier formation this specimen is of little value, as it could 

probably not be recognized or discriminated if 

found elsewhere. For this reason there is little 

use jn attempting comparisons with described 

species, though incidentally it may be compared 

as being similar in type to Eq_uisetum prelaevigatum Cockerell (E. laevigatum Lesquereux3), 

from the Denver formation of Colorado. 

Occurrence: Frontier formation, north side 

of Little Muddy Creek, about 1 mile east of 

Cumberland, Wyo., in sec. 29, T. 19 N., R. 116 

W. Collected by A. C. Veatch in 1905. 

Family SMILACElE. 

Smilax? coloradensis Knowlton, n. sp. 

Plate XXXIII, figure 1. 

Leaf small, membranaceous, regularly elliptical, abruptly rounded below to a very slightly 

heart-shaped base, apex destroyed but apparently rather obtusely pointed; three-ribbed 

from base, the midrib slightly the stronger, 

lateral ribs passing up nearly or quite to the 

apex, each with several branches on the outside 

which join and produce a semblance of an additional rib on each side; no secondaries observed 

on the midrib, but a few strong nervilles between the ribs; fine nervation not retained. 

The specimen figured is all that was found 

of this form. It is about 5 centimeters long 

and 3.5 centimeters wide. The nervation is so 

poorly preserved that hardly anything but the 

main ribs is retained. It is for this reason that 

the generic reference has been questioned, 

though it has the size, shape, thickness, and, so 

far as can be made out, the essential nervation 

of certain living forms of the genus. More and 

better material will be necessary to settle the 

matter fully. 

Occurrence: Frontier formation, dump of · 

mine No. 1, Cumberland, Wyo. Collected by 

F. H. Knowlton August 5, 1908. 

Family MYRICACElE. 

Myrica nervosa Knowlton, n. sp. 

Plate XXXIV, figure 1. 

In the small collection obtained about 1! 

miles south of Cumberland, Wyo., there are a 

number of fragmentary leaves of Jfyrica. The 

a Lesquereux, Leo, U.S. Geol..oSurvey Terr. Rept., vol. 7, p. 68, pl. 6, 

fig. 6, 1878. 
86 SHORTER CONTRTBUTIONS TO GENERAL GEOLOGY, 1917. 

nervation is very distinct and characteristic, 

and although the specimens are so much broken 

that the size and shape can not be fully made 

out, it seems best to put the form on record so 

that it may be looked for in the future. 

This species is narrowly lanceola'te, probably 

acuminate at base and apex, ·and has perfectly 

entire margins. The length was apparently 8 

or 9 centimeters and the width about 2 centimeters. · The leaf substance is thick and leathery, as shown by the wrinkled appearance of 

the leaves. rrhe midrib is exceedingly strong. 

The secondary nervation is thin and irregular, at an angle of 50° or more, much curved 

upward, each principal nerve arching just outside the margin and producing an intramarginal 

"stitch." There are numerous intermediate 

.secondaries which pass up and join the bows of 

the larger nerves, or disappear in a network of 

nervilles. The finer nervation produces a network of irregular areas. 

This species is, in a way, of the type of Myrica 

torreyi Lesquereux, of the Montana group and 

slightly younger horizons. It differs markedly 

from that species, however, in its smaller size, 

entire instead of serrate margins, and secondaries of two sizes, the larger ones forming the 

intramarginal vein. The nervation is also at a 

more acute angle than in M. torreyi. 

09currence: Frontier formation, 1l miles 

south of Cumberland, Wyo., in theSE. i sec. 6, 

T. 18 N., R. 116 W. From same horizon as 

plant beds 1 mile east of Cumberland. Collected by T. W. Stanton September 1, 1913. 

Family SALICACEAE. 

Salix cumberlandensis Knowlton, n. sp. 

Plate XXXVIII, figure 3. 

Leaf firm in texture, lanceolate, 8 centimeters 

long, 2 centimeters wide, abruptly rounded 

below to the short, thick petiole, broadest at 

and below the lower third of the blade, whence 

it is gradually narrowed to the slenderly acuminate apex; margin finely and evenly crenate 

throughout; midrib very thick, especially below; 

secondaries strong, 16 or more pairs, alternate, 

emerging at an angle of 30° or 35°, much curved 

upward anQ_ apparently effused near the margin; 

finer ner:vation not retained. 

This handsome little species is represented 

only by the very perfect example figured. It 

is well marked by its narrowly oblong-lanceolate 

outline, abruptly rounded base, finely crenulate 

margin, and numerous strong, apparently 

camptodrome secondaries. 

Occurrence: Frontier formation, 1! miles 

south of Cumberlang, Wyo., in theSE. ! sec. 6, 

T. 18 N., R. 116 W. From same horizon as the 

plant beds 1 mile east of Cumberland. Collected by T. W. Stanton September 1, 1913. 

Salix frontierensis Knowlton, n. sp. 

Plate XXXV, figure 4a. 

Leaf small, apparently rather thick, elliptical lanceolate, broadest at ~ point below the 

middle, whence it rounds rather abruptly to 

the short, thick petiole; apex destroyed but 

apparently acuminate; margin perfectly entire; midrib very strong for a short distance, 

then much thinner; secondaries 10 or 12 pairs, 

very thin and delicate, curved upward, camptodrome; finer nervation obscure. 

The little leaf figured is unfortunately the 

only one of this kind noted in the collection. 

It was about 3.5 centimeters long and 1.3 centimeters wide; the petiole is about 3 millimeters long. 

Occurrence: Frontier formation, 1~ miles 

south of ·Cumberland, Wyo., in the SE. i sec. 

6, T. 18 N., R. 116 W. From same horizon 

as plant beds 1 mile east of Cumberland. Collected by T. W. Stanton S~ptember 1, 1913. 

Family FAGACEAE. 

Quercus stantoni Knowlton, n. sp. 

Plate XXXIII, figures 2-4. 

Leaves membranaceous,- rather broadly lanceolate, long, wedge-shaped at base, much 

more abruptly narrowed above to an obtusely 

acuminate apex; margin entire below, coarsely 

few-toothed or lobed above, the teeth separated 

by shallow sinuses, sharp, mucronate-tipped; 

petiole strcmg, at least 1.5· centimeters long; 

midrib very strong below, not much thinning . 

above; secondaries about 10 or 12 pairs, mainly 

alternate, at an angle of 45°, running nearly 

straight to the teeth below, slightly curved upward above; nervilles numerous, strong, irregular, finer nervation forming a coarse, irregularly quadrangular network. 

This species is represented by nearly a dozen 

specimens, none of ~hich, however, is complete. The length, including the petiole, must 

have been at least 10 or 12 centimeters and 

the width between 3 and 4 centimeters. The 
A FOSSIL FLORA FROM THE FRONTIER :E'ORMATION OF SOUTHWESTERN WYOMING. 87 

species is well marked by the long, wedgeshaped base, more obtuse apex, and coarse 

marginal teeth or lobes, which are all mucronate-tipped, thus indicating that it is a member of the black-oak group. In figure 3 is 

shown a cluster of three leaves that were pro bably attached to the same branch, though the 

actual union is not shown. The best preserved 

of these gives a very satisfactory view of the 

lower half of the blade, with its strong petiole 

and mucronate teeth. In figure 2 is shown a 

very complete apical portion of a leaf of the 

same size as the one in figure 3. The basal 

portion of another well-preserved leaf is seen 

in figure 4. 

Among fossil species of Quercus the present 

species is rather closely related apparently to a 

number from the Senonian of Haldene, Westphalia, as described by Hosius and Von der 

Marck.1 It is perhaps nearest to Quercus formosa, from which it differs in being broader 

and in having larger, sharper, mucronatetipped teeth. From Quercus sphenobasis it 

differs in its fewer, larger teeth and fewer secondaries. 

Occurrence: Frontier formation, 1~ miles 

south of Cumberland, Wyo., in the SE. l sec~ 

6, T. 18 N., R. 116 W. From same horizon as 

plant beds 1 mile east of Cumberland. Collected by T. '-l{. Stanton September 1, 1913. 

Family MORACEAE. 

Ficus fremonti Knowlton, n. sp. 

Plate XXXIV, figures 4-6; Plate XXXV, figures 4c, 5. 

Glossopteris phillipsii? Brongniart . .. Hall, in Fremont, 

op., cit., Appendix B, p. 305, pl. 2, figs. 5, 5a-c. 

Lesquereux, U. S. Nat. Mus. Proc., vol. 11, p. 37, 

1888. 

Leaves small, very thick and coriaceous, 

narrowly lanceolate, broadest below the middJe, 

whence they narrow below "to a rather long, 

wedge-shaped base and· above to a very long, 

narrow acuminate apex; margin perfectly 

entire; petiole short (1 centimeter), relatively 

strong; midrib very stro1!-g; secondaries immersed in the substance of the leaf and indjstinct, numerous, at an acute angle, camptodrome; finer nervation obscure. 

This form is represented by 25 or more specimens, few of which are perfect. It is a small, 

very narrowly lanceolate leaf, 6 to 8 or 9 cen ti1 Hosius, A., and Von der Marek, W., Flora der westf3Jischen Kriede. 

formation: Palaeontographica, vol. 26, p. 164 [40], pl. 31, fig. 81, 1880. 

meters long and 1 to 2 centimeters wide, with a 

petiole 1 centimeter or slightly over in length. 

I't is especially distinguished by its long, narrowly acuminate apex. 

The species here called Ficusfremonti has had 

a most interesting history. It was first collected by Fremont in 1843 and was identified by 

Hall as Glossopteris phillipsii, for the reason, 

he adds, that Brongniart's species afforded ''the 

only description and figure accessible to me to 

which this fossil bears any near resemblance." 

Examination of Brongniart's figure 2 shows that 

this form certainly does resemble it so far as 

size and shap.e go but is totally different in 

nervation. Glossopteris phillipsii has of course 

a pteroid nervation with close, parallel, forking veins, but the secondary nerves in the 

leaves here described, as may be seen from the 

figures, are distinctly those of a dicotyledon. 

Fortunately, two of the original Fremont 

specimens (Hall's figs. 5 and 5b) are preserved 

in the United States National Museum and are· 

shown here(Pl. XXXIV, fig. 6; Pl. XXXV, fig. 

5). These leaves passed under Lesquereux's eye, 

and although he lists them under Glossopteris 

phillipsii he makes the following statement: 3 

''This is remarkably similar in form of leaves 

and nervation to Glossochlamys transmutans 

Gardner and Ettingshausen (British Eocene 

flora, p1. 3, fig. 3; pl. 12, fig. 8). The specimens of Fremont show indistinctly nervilles 

between the lateral nerves composing irregular, 

square meshes." 

The figures of Giossochlamys transmutans 

given by Gardner and Ettingshausen show that 

to an intents and purposes this form is a dicotyledon, and in fact these authors admit that 

Saporta, whom they consulted, objected to the 

reference of this fossil to a fern, and Heer 

stated flatly that "it is not a fern, but a leaf of a 

dicotyledon." There can be absolutely no 

question about it-the leaves under consideration belong to a dicotyledon and have nothing 

to do with ferns. 

It was largely on the basis of Hall's identification of these leaves as Glossopteris phillipsii 

that the beds were referred to the Jurassic. 

On this point Hall says: "The geological position of the fossil is so well ascertained to be the 

schists of the upper part of the Oolitic period 

2 Brongniart, Adolph, Histoire des vegeteaux fossiles, p. 225, pl. 51 bis, 

fig. 2, 1828. 

3Lesquereux, Leo, Recent determinations of fossil plants from Kentucky, Louisiana, * * * : U. S. Nat. Mus. Proc., vol. 11, p. 37, 1888. 
88 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

that, relying upon the evidence afforded by a 

single species, we might regard it as a strong 

argument for referring all the other specimens 

to the same geological period." 

region, it might well be discarded. It simply 

calls attention to the presence of a large leaf 

whose more definite placing must be left to 

the future. 

Occurrence: Frontier formation, mine No. 1, 

half a mile east of Cumberland, Wyo. Collected by T. W. Stanton and F. H. Knowlton 

in 1908. ' 

Ficus? sp. 

Plate XXXI'V,.figures 2, 3. 

Ficus fremonti agrees very well in shape with 

Ficus proteoides Lesquereux/ from the Dakota 

sandstone of Kansas, but the latter is a much 

larger .leaf and has a more open nervation. 

In shape, size, and nervation it · is even closer 

to Ficus Zanceolata acuminata Ettingshausen, as 

figured by Lesquereux,2 from the Dakota sandstone of Kansas. This species, however, is The collection obtained half a mile east of 

somewhat longer and broader and has the Cumberland contains a number ·of narrow 

nervation more regular and at a less acute leaves that are included here only on the 

angle of divergence. ground that it seems desirable to enumerate 

As stated on page 80, one of the original everything known from this general region. 

specimens figured by Hall sh'Owed on one side of They are preserved in a coarse-grained sandthe leaf round bodies which have now been stone that has obscured most of the characteridentified as the egg mass of an insect, prob- istic featu~es-in fa~t, about all t~at c~n _be 

ably a micro1epidopterous insect. It is shown made out IS the outhne and ~he th1ck m1dr1b. 

in figure 5 of Plate XXXVI. · They are narrowly lanceolate leaves that are 

Occurrence: Frontier formation about 1 rather abruptly rounded to· the base and 

mile east of Cumberland, Wyo. ' Originally appare~tly long acumin~te at the apex. The 

collected by J. C. Fremont August 19, 1843; len~th IS about 10 centrmeters and the width 

subsequently found at or near the same place a httle over 2 centimeters. The midrib is 

by F. H. Knowlton and T. W. Stanton in 1908. strong, and there is sollle slight indication of 

Ficus? sp. 

. Plate XXXV, figure 1. 

A small collection made from a rather coarsegrained shaly sandstone about 300 feet above 

the main plant locality east of Cumberland 

contains a number of fragmentary leaves that 

seem to belong to Ficus, but there are little 

more than outlines to afford basis for a judgment. The leaf shown in figure 1 is one of the 

best preserved of these specimens. It is 

ovate, with an abrttptly rounded truncate 

base, probably obtusely acuminate apex, and 

entire margins. The length was about 10 or 11 

centimeters and the width nearly 5 centimeters. 

Even the primary nervation is so obscure that 

it is made out with difficulty. It consists of a 

fairly strong midrib and apparently a strong 

rib or secondary arising near the base and 

passing up for a long distance, but it is more 

or less uncertain. 

This form is so obscure that it is of little 

value, and except for the desirability of 

enumerating all the plants present in this 

1 Lesquereux, Leo, Flora of the Dakota group: U.S. Geol. Survey Mon. 

17, p. 7i, pl. 12, fig. 2, 1892. 

'Idem, p. 85, pl. 13, fig. 4. 

secondary branches, but they are very uncertain. 

This form might be compared with a number 

of long, narrow-leaved species of Ficus or 

certain entire-leaved species of Salix, 'but 

absence of essential features makes definite 

comparisons of little value. 

Occurrence: Frontier formation, half a mile 

east of Cumberland, Wyo. Collected by F. H. 

Knowlton and T W. Stanton August 5, 1908. 

Family LAURACEAE. 

Cinnamomum hesperium Knowlton, n. sp. 

Plate XXXVIII., figure 2. 

Leaf semicoriaceous or finer in texture, narrowly lanceolate, broadest near the middle, 

whence it narrows in almost the same degree 

to both base and apex; length 7 centimeters 

including the petiole, which is about 8 millimeters long; width about 13 millimeters; 

petiole relatively short, stout; midrib very 

strong below, becoming much thinner in the 

upper half of the blade; lateral ribs at an 

acute angle, arising at a point about 5 millimeters above the base of the blade, passing up 

and joining the lowest pair of secondaries 

near or above the middle, each with two or 
A .FOSSIL FLORA FROM THE FRONTIER FORMATION OF SOUTHWES,TERN WYOMING. 89 

three secondary branches on the outside; 

secondaries on the midrib three pairs, alternate, 

lowest arising far below the middle of the blade, 

arching upward and runniug along near and 

gradually lost in the margin; nervilies obscure, 

apparently close, parallel, unbroken, and at 

right angles to the ribs and secondaries. 

This species is represented only by the 

exan1ple figured, which fortunately is practically perfect, so that its characters can be made 

out with certainty. It is with much hesitation 

described as new. At one time it was identified ·with a specimen from Hodges Pass, 

Wyo., described and figured by Ward 1 under 

the name Ginnamomum Zcinctolatum (Unger) 

Heer but later given the name G. wardii 

Knowlton 2 on the ground that it was not 

conspecific with the European species. Except 

in the matter of size these two leaves are 

undoubtedly close. Thus, G. wardii is 15 

centimeters long and 2.5 centimeters wide, 

G. hesperium is 6 centimeters long and 1.4 

centimeters wide. There are also other slight 

differences. In G. wardii the base is more 

obtuse and rounded, the lateral ribs at a less 

acute angle and without outside se0ondaries, 

and the secondaries on the midrib are closer 

and more numerous, but these are all comparatively unimportant divergences that might 

possibly break down if a series was available for 

comparison instead of a single leaf of each form. 

The leaf found near Cumberland, Wyo., is 

also strikingly similar in size, shape, and general appearance to Ginnamomum salicifolium 

Staub, 3 from the well-known Tertiary beds at 

Sotzka, in Styria, but here again there are 

noticeable slight differences. Thus there are 

no outside secondaries on the lateral ribs, and 

the secondaries on the midrib are more numerous and confined to the upper half or upper 

third of the leaf. 

Ginnamomum salicifolium was segregated by 

Staub from G. lanceolatum (Unger) Heer, on 

the basis of its generally narrower shape, 

higher secondaries, etc., but the difference is 

not great. 

The geologic horizon at which the leaf G. 

wardii was found is more or less in doubt. The 

1 Ward, L. F., Synopsis of the flora of the Laramie group: U. S. Geol. 

Survey Sixth Ann. Rept., pl. 46, fig. 12, 1886. 

~Knowlton, F. H ., A catalogue of the Cretaceous and Tertiary plants 

of North America: U.S. Geol. Survey Bull.152, p. 69, 1898. 

a Staub, Moriz, Die Geschichte des genus Cinnamomum, p. 65, pl. 12, 

figs. 7-14, 1905. 

specimen was supposed by Ward to be from 

beds of Laramie age as then interpreted, but 

the work of Veatch appears to place it in the 

upper part of the Adaville formation of the 

Montana group, or nearly 10,000 feet above the 

horizon which supplied the Cumberland leaf. 

The species was not found in any of the recent 

collections made in this general region. 

Although these two species (G. wardii and 

what is here called G. hesperium) are undoubtedly close together, the best that can be done 

under the circumstances, considering the differences in size and nervation already pointed 

out, as well as the apparent disparity in age, 

is to regard them as distinct until additional 

material can be obtained. 

Occurrence: Frontier formation, 1! miles 

south of Cumberland, Wyo., in the SE. t sec. 

6, T. 18 N., R. 116 W. Same bed as plant 

locality 1 mile east of Cumberland. Collected 

by T. W. Stanton September 1, 1913. 

Cinnamomum? sp. 

Plate XXXV, figure 2. 

There are in the collection several very 

fragmentary leaves that appear to belong to 

the genus Ginnamomum, though they are 

obscure at critical points. The one figured is 

ovate-lanceolate and has a rounded wedgeshaped base and an acuminate apex. The 

length is 9 centimeters and the width a little 

less than 5 centimeters. The midrib is strong; 

the lateral ribs are somewhat thinner and pass 

up nearly to the apex. There are several 

secondary branches on the outside of the lateral 

ribs, but otherwise the nervation can not be 

made out. 

Occurrence : Frontier formation, half a mile 

east of Cumberland, Wyo. Collected by F. H. 

Knowlton and T. W. Stanton August 5, 1908. 

Family PROTEACEAE. 

Dryandroides lanceolata Knowlton, n. sp. 

Plate XXXIV, figure 7. 

Leaves coriaceous, narrowly lanceolate, base 

not seen but apparently rather abruptly narrowed to a short, wedge-shaped basal portion, 

prolonged above into a very long, acuminate 

apex which is minutely emarginate at the tip; 

margin in lower and middle portions distinctly 

toothed, the teeth sharp 'pointed, separated by 

very shallow sinuses; margin in upper portior.. 
90 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

undulate and finally entire; midrib very strong; 

secondaries numerous (probably at least 15 

pairs), alternate, at an angle of 35° or 40°, 

considerably curved upward, entering the teeth 

or arching and each joining the secondary 

next above and sending a short, outside branch 

to the tooth; secondaries in the narrowed, 

entire apical portion of the blade arching 

upward for a considerable distance and disappearing in or near the margin; nervilles 

numerous, mainly broken and at right angles 

to the secondaries. 

The portions of the two leaves shown in 

figure 7 are all that has been observed of this 

well-marked form. It is not possible to ascertain the exact length, but it could hardly have 

been less than 11 or 12 centimeters. The 

greatest width is slightly less than 2 centimeters. 

The large segment referred to this species is 

certainly very oaklike in appearance, but the 

long, slenderly acuminate apical portion is 

much less so, and it seems best referred to the 

genus Dryandroides. It is, for instance, very 

similar to D. quercinea V elenovsky, 1 from the 

Cretaceous of Bohemia. It is, however, . a 

larger, longer leaf, with a narrower apical 

portion, fewer lower teeth, and fewer secondaries at a more acute angle. 

Dryandroides quercinea has been reported by 

Hollick 2 from the Magothy formation at Gay 

Head, Marthas Vineyard, Mass., but this reference depends on two fragmentary leaves and is 

open to some question. 

The only other species of Dryandroides 

tentatively accepted as North American was 

described by Lesquereux 3 under the name 

Quercus cleburni. It comes from Black Buttes, 

Wyo., and is very different from the present 

form; in fact, it is doubtful if it should be 

placed in Dryandroides. 

Occurrence: Frontier formation, 1! miles 

south of Cumberland, Wyo., in the SE. 1- sec. 

6, T. 18 N., R. 116 W. From same horizon as 

plant bed 1 mile east of Cumberland. Collected by T. W. Stanton September 1, 1913. 

1 Velenovsky, J., Die Flora der bohmischen Kreideformation: Beitr. 

PaUi.ontologie Oesterr.-Ungams u. des Orients, Band3, Heft 1, p. 33 (8), 

pl. 10 (2), 1883. 

2 Hollick, Arthur, The Cretaceous flora of southern New York and 

New England: U. S. Geol. Survey Mon. 50, p. 60, pl. 8, figs. 18, 19, 190(). 

a Lesquereux, Leo, U.S. Geol. Survey Terr. Rept., vol. 7, p. 154, pl. 

20, fig. 2, 1878. 

Family RANUNCULACEAE? 

Dewalquea pulchella Knowlton, n. sp. 

Plate XXXVI, figures 1-3; Plate XXXVII, figures 1-3. 

Leaves of medium or small size, palmately 

decompound, the segments usually five but 

occasionally six in number; petiole extremely 

long, much longer than the longest foliar segment, splitting at top into two nearly equal 

branches, one of which usually gives rise to 

two and the other to three segments, though 

the middle segment in a five-parted leaf may 

be nearly or quite free; segments all narrowly 

linear-lanceolate, of approximately the same 

size, the other segments slightly inequilateral, 

the middle one in some leaves slightly smaller 

than the others, all long and very narrowly 

wedge-shaped at base, acuminate at apex; 

margin of segments usually entire' for a short 

distance at the base, thence strongly and sharply 

serrate; midrib strong, straight; secondaries 

obscure owing to the thickness of the leaf substance, numerous, apparently subopposite, at 

an angle of about 40°, slightly curved upward, 

all but the lower ones craspedodrome and ending in the marginal teeth; finer nervation not 

retained. 

This splendid species is represented by nearly 

twenty specimens, six or seven of which have 

been figured. In none of the specimens are all 

the segments preserved entire, but some are 

nearly perfect, and hardly any of them. is so 

fragmentary as not to show the manner in 

which the segments arise from the top of the 

petiole. Apparently in a majority of the 

leaves of this genus from other areas, as 

described, the segments are so broken and 

detached that it becomes a matter of difficulty 

to interpret them satisfactorily. The leaves 

here described, however, are so well preserved 

that there can be absolutely no question as to 

their being congeneric with the type and typical species from European deposits, from 

which the genus was first made known. 

The present leaves are rather small compared 

with those of typical members of the genus. 

None of the segments exceed 8 or 9 centimeters 

in length and 1.5 centimeters in width, and 

apparently most of them are only 6 or 7 centimeters long and 1 centimeter or less in width. 

The segments are cut so deeply that they are 
A FOSSIL FLORA FROM THE FRONTIER FORMATION OF SOUTHWESTERN WYOMING. 91 

almost free, and there is very little evidence of 

their being unequal-sided at the base. In only 

one specimen, that shown in Plate XXXVI, 

figure 3, is there six seg1nents, all the remainder 

having five very symmetrically spaced divisions. 

The petiole, which is preserved entire in several specimens, is extremely long and slender. 

In the leaf shown in Plate XXXVII, figure 2, 

for instance, it is nearly 5 centimeters long and 

probably exceeds the length of the segments. 

The average length is about 4 centimeters. 

This species is very closely related to Dewalquea insignis Hosius and Von cler Marek, 1 from 

the Upper Senonian of Westphalia-so closely 

related, in fact, that it would perhaps do no 

great violence to call them the same. 'l'he 

present form differs from the Westphalian 

species in its generally sma1ler size, longer petiole, usually fewer segments with much larger, 

sharper teeth, and, so far as can be made 

out, fewer, more curved secondaries. These, 

however, are all minor differences that might 

well be covered by individual variation; but 

in consideration also of the difference in geo-

. graphic and stratigraphic position, it is perhaps 

as well to consider the Wyoming form under 

another name. 

Dewalquea insignis was recorded by Heer 2 

from both the Atane and Patoot beds of 

Greenland, and by Hollick 3 from the Cretaceous of Staten Island, but as Berry 4 has recently pointed out, ''both these determinations 

are based upon fragments of single leaves and 

are, in the writer's judgment, entirely untrustworthy." 

The genus Dewalquea was established by 

Sa porta and Marion 5 in 187 4, and was based on 

two species (Dewalquea lwldemiana and D. 

aquisgranensis) from the Senonian of W estpha-

~ lia, sent to them by Debey under the manuscript names Araliophyllum and Grevillea, and 

one (D. gelindensis) collected by themselves 

from the Paleocene of Gelinden, Belgium. 

Since that date 10 additional species, all from 

1 Hosius, A., and Von der Marek, W., Die Flora der westfiUisc:hen 

Kreideformation: Palaeontographica, vol. 26, p. 172 (48), pl. 32, figs. 

111- 113; pl. 33, fig. 109; pl. 34, fig. 110, 1880. 

z Heer, Oswald, Flora fossilis arctica, vol. 6, Abt. 2, p. 86, pl. 25, fig. 7, 

pl. 33, figs. 14-16, 1882; vol. 7, p. 37, pl. 58, fig. 3; pl. 62, fig. 7, 1883. 

3 Hollick, Arthur, The Cretaceous fiora of southern New York and 

New England: U.S. Geol. Survey Mon. 50, p. 106, pl. 8, fig. 24, 1906. 

4 Berry, E. W., The Upper Cretaceous and Eocene fioras of South 

Carolina and Georgia: U S. Geol. Survey Prof. Paper 84, p. 42, 1914. 

o Saporta, Gaston de, and Marion, A. F., Essai sur l'etat de la vegetationa l'epoque des marnes heersiennes de Gelinden: Acad. roy. Belgique Mem. cour. et des sav. etrang., vol. 37, p. 55, 1874. 

the Upper Cretaceous, have been named by 

different authors. Of these one (D. gronlandica 

Heer) is from the Patoot and Atane beds of -

Greenland, two (D. dakotensis Lesquereux and 

D. primordial is Lesquereux) from the Dakota 

sandstone of Kansas and Minnesota respectively, one (D. trijoliata Newberry) from the 

Raritan formation of New Jersey, and one 

(D. smithi Berry) from the Tuscaloosa formation of Alabama and the Black Creek formation 

(Middendorf arkose member) of South Carolina. 

Of the Greenland and American species all 

but one (D. smithi Berry) 6 have leaves with 

only three segments or leaflets and are very 

unlike D. insignis or D. pulchella. The species 

described by Berry is a very handsome one; 

the leaves have five segments which are from 

8 to 16 centimeters in length and sharply 

serrate, and the lateral segments are curiously 

unequal-sided at the base. This is undoubtedly- a Dewalquea, but it is very distinct from 

the species here described. 

The systematic affiliations of the genus 

Dewalquea are still more or less obscure. A8 

may be inferred from the names suggested by 

Debey, he regarded it as belonging either in 

the Araliaceae or in the Proteaceae, but when 

Saporta and Marion established the genus they 

took occasion to review the matter with great 

care, and after comparing it with several genera 

such as Aralia, Ampelopsis, and Arisaema (a 

monocotyledon of the family Araceae) concluded that it had the greatest affinity with 

the tribe Helleboreae of the family Ranunculaceae. The Helleboreae in the living flora 

are herbaceous, but Saporta and Marion state 

that the presence of a Cretaceous or early 

Eocene shrubby ancestor would be quite in 

accord with the evolutionary history of some 

other groups. 

Although these authors pointed out the 

reasons opposing the reference of Dewalquea 

to the Araliaceae, such a reference seems to 

the writer to be entitled to further consideration. It .is, for instance, difficult to escape 

the conviction that certain leaves from the 

Dakota sandstone referred to Aralia may well 

have been ancestral to leaves of Dewalquea 

of the type of D. insignis, D. pulchella, etc. 

Take, for example, the species described by 

6 Berry, E. vV., op. cit., p. 41, pl. 8, figs. 3-9 (restoration, fig. 1 in 

text). 
92 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

Lesquereux 1 as Aralia wellingtoniana. This 

is a medium-sized leaf with five deeply cut, 

sharply serrate lobes in which the secondary 

nervation is close, parallel, and craspedodrome 

in the upper portions. If the separation of 

these lobes were continued .a short distance 

until the lobes were nearly or quite free, 

though still showing the method of origin from 

the branches of the petiole, a palmately decompound leaf would result that seemingly 

would be a Dewalquea. A further step in this 

process is shown in one of the Dakota leaves 

figured by Lesquereux 2 under the name 

Aralia saportanea var. deformata. Here the 

central lobe is reduced and cut almost to the 

base. The lateral lobes are also deeply cut 

and the margin· below the major fork of the 

petiole is reduced to a very narrow web. A 

very slight continuation of this lobing would 

make these segments free or at least cut them 

to the branches of the petiole. Hence it seems 

to the writer a less violent assumption to 

derive the decompound, coriaceous-leaved 

species of Dewalquea from an equally coriaceous deeply lobed Aralia of. the type above 

indicated than to suppose them to be the Cretaceous ancestors of the living herbaceous 

Helleboreae. 

Occurrence: Frontier formation, 1 mile east 

of Cumberland, Wyo., in sec. 29, T. 19 N., 

T. 116 W. Collected by A. C. Veatch in 

August, 1905. 

Family ARALIACElE. 

Aralia veatchii Knowlton, n. sp. 

Plate XXXVI, figure 4; Plate XXXVII, figure 4; Plate 

XXXVIII, figure l; Plate XXXIX. 

Aralia cf. A. saportana Lesquereux. Knowlton, in Veatch, 

Am. Jour. Sci., 4th ser., val. 21, p. 459, 1906. 

Outline of whole leaf not known, but clearly 

a leaf of large size ·and firm texture; palmately 

three-lobed and, presumably at least, fivelobed, the central lobes lanceolate, slenderly 

acuminate at apex, slightly contracted at the 

base; margin conspicuously toothed, the teeth 

sharp pointed, separated by shallow sinuses; 

lateral lobes at an angle of about 45° with the 

middle lobe and separated from it by a deep 

narrow sinus, margin entire below, becoming 

toothed above like the central lobe; nervation 

· of lobes consisting of a very strong midrib and 

12 or 14 pairs of fairly strong secondaries which 

1 Lesquereux, Leo; The flora of the Dakota group: U. S. Geol. Survey 

Mon. 17, pl. 22, fig. 2, 1891. 

2 Idem, pl. 23, fig 1. 

emerge at an angle of 45° or 50°, are nearly 

straight, and end in the marginal teeth; nervation of lateral lobes similar, but secondaries 

more curved upward and camptodrome in the 

lower untoothed portion; finer nervation consisting of numerous strong nervilles, which are 

irregular and in places broken, and finer quadrangular areas. 

The above description is in the main drawn 

from the specimen shown in Plate XXXVI, 

figure 4, which is the best one available. It 

consists of a nearly perfect central lobe and a 

small portion of one lateral lobe, the two being 

separated hy ·a deep, narrow sinus. It is 

impossible to ascertain the size of this leaf 

when it was perfect, or to determine whether 

it had more than three lobes. It must have 

been 17 or 18 centimeters long and presumably 

20 centimeters or more broad between the tips 

of the lateral lobes. From its analogy with a 

species to which it is presumed to be related, 

it is thought probably to have been five-lobed, 

but this is not known. 

If I am correct in referring the other specimens here figured (Pl. XXXIX) to Aralia 

veatchii, the whole leaf was rriuch larger than 

the dimensions given above. Thus, the specimen shown in Plate XXXVIII, figure 1, could 

hardly have been less than 20 centimeters in 

length and 7 or 8 centimeters in greatest width. 

In Plate XXXIX there are portions of three 

leaves or, more properly, lobes, which, while 

not now in actual organic connection, are so 

placed as to lend support to the idea that this 

was a huge five-lobed .leaf. The central lobe, 

if it is such, was about 20 centimeters long and 

7 centimeters wide, and the other was about 16 

centimeters ·long and 6 centimeters wide. 

Both of these are more elliptical-lanceolate in 

shape than that shown in figure 1, and the 

margin is less sharply toothed. The fragment 

of a leaf given in Plate XXXVII, figure 4, is 

quite distinctly undulate-toothed. The nervation, however, is practi~ally the same in all the 

specimens figured under this name, and this is 

one of the strong reasons for considering them 

all as conspecific. 

There seems to be little or no doubt as to the 

propriety of referring these leaves to the genus 

Aralia on the basis of their resemblance to 

leaves from different horizons that have been 

so regarded. One of the species that is perhaps 

nearest to the present species, as exemplified in 

Plate XXXVI, figure 4, is Aralia saportanea 
A 'FOSSIL FLORA FROM THE FRONTIER FORMATION OF SOUTHWESTERN WYOMING. 93 

Lesquereux, 1 from the Dakota sandstone of 

Kansas. The Dakota species is a smaller form 

and has the lateral lobes at a much inore acute 

angle, the margins less conspicuously toothed, 

and the secondaries more curved upward, but 

they may well enough have belonged to the 

same genus. 

Occurrence: Frontier formation, north side 

of Little Muddy Creek, about 1 mile east of 

Cumberland, Wyo., in sec. 29, T. 19 N., R. 

116 W. Collected by A. C. Veatch in 1905. 

Family STAPHYLEACEAE 1 

Staphylea? fremonti Knowlton. n. sp. 

short-stalked, whereas in the fossil form the 

central leaflet has a markedly shorter stalk 

than the.,lateral ones. The margin in the living 

leaf is finely, sharply serrate, but in the fossil 

leaf it is entire. Again, the texture in S. 

fremonti was evidently much thicker than in 

S. trifolia. The shape, size, and nervation are 

approxin1ately the same in both forms. 

It wa,s at first thought possible that the 

leaves under consideration might be congeneric 

with Dewalquea tr·ifoliata Newberry, 2 from the 

Raritan formation of New Jersey, especially in 

view of a statement made by Berry 3 to the 

effect that "it is remarkable that where this 

Plate XXXII, figures 4, 5; Plate XXXIII, figure 5. genus has been found in abundance, two species 

Leaves trifoliolate, the leaflets petioled, all are usually described-one entire · and one with 

arising from the same point at the top of the 

main petiole; leaflets all of about the same size, 

elliptical-lanceolate, broadest near or just below 

the middle, whence they are gradually rounded 

or narrowed to the wedge-shaped base and to 

an acuminate apex; margin of leaflets perfectly 

entire; midrib exceedingly strong, straight; 

secondary nervation obscured by the thick 

substance of the leaflet; secondaries emerging 

at a low angle, close, nearly parallel, camptodrome, arching, and apparently joining well below the margin; finer nervation not discernible. 

toothed margins," the inference being that both 

forms probably grew on the same plant. This 

condition can not be true in the present instan-ce, for the leaves under discussion are 

clearly trifoliolate, while in Dewalquea the leaf 

is merely palmately decompound. 

One of the leaflets (Pl. XXXIII, fig. 5) shows 

a mine made in the leaf substance by an insect 

larva. (See p. 80.) 

Occurrence: Frontier formation, 1 mile east 

of Cumberland, Wyo. Collected by F. H. 

Knowlton and T. W. Stanton in 1908. 

Unknown systematic position. 

Phyllites :ficifolia Knowlton, n. sp. 

This beautiful species is represented by the 

two specimens figured, as well as their counterparts and a number of detached leaflets. They Plate XXXV, figure 3. have a thick general petiole of unknown length 

but at least 1 centimeter long. Standing on The leaf figured is all that was noted of this 

the top are the petioles of the leaflets, each of form. It was evidently a leaf some 15 or 18 

which is from 5 to 8 millimeters in length. centimeters in length and about 6 centimeters 

The petiole of the middle leaflet is uniformly a in width. It appears to have been ellipticallittle shorter than the lateral one. The leaf- lanceolate, very gradually narrowed at the 

lets are 3.5 to 4 centimeters long and about 12 base, and .Pr~s~ma.bl~ acuminate ~t the ape::. 

millimeters wide. The leaflets are very thick The margin IS Indistinct. There IS some eviin texture and, with the exception of the ex- dence ~o ~how that t~ere were a_fm: low teeth, 

tremely strong midrib, the secondary nerva- 1 b_ut this IS not certain. Th~ midrib ':as relation has been observed in only one or two leaf- tlvely strong. The secondaries, _of whiCh there 

lets. Here it is seen to be . thin close nearlv were probably about a dozen pairs, were alterparallel, and arching some dista~ce below th~ nate, at an angle of 35° or 40°, remote in the 

middle of the blade, somewhat curved upward, marg1n. 

. There is some uncertainty as to the propriety 

of this generic reference. These leaves appear 

to be close enough to the living Staphylea tr~folia 

Lesquereux to warrant their being considered 

as congeneric with it, though there are some 

differences. Thus, in the living form the lateral leaflets are sessile and the central one is 

1 Lesquereux, Leo, U.S. Geol. Survey Terr. Rept., vol. 8, p. 61, pl. 8, 

fig. 1, 1883. 

and presumably camptodrome. None of the 

finer nervation can be made out. 

This is probably a Ficus, but in the absence 

of definite knowledge concerning certain of the 

essential characters it seems best to leave its 

allocation to further and better material. 

2 Newberry, J. S., The flora of the Amboy clays: U. S. Geol. Survey 

Mon. 26, p. 129, pl. 22, figs. 4-i, 1895. 

a Berry, E. W., The Upper Cretaceous and Eocene floras of South 

Carolina and Georgia: U.S. Geol. Survey Prof. Paper 84, p. 42, 1914. 
94 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

Occurrence: Frontier formation, 1 mile east 

of Cumberland, Wyo. Collected by F. H. 

Knowlton and T. W. Stanton in 1908. · 

Phyllites dent~Ja Knowlton, n. sp. 

Plate XXXIV, :figure 8. 

The example figured is all that was found of 

this form. It is a segment apparently from 

the middle portion of a narrowly lanceolate 

leaf of membranaceous texture. It was acuminate at the apex, but the base is not known. 

The margin is provided with numerous low, 

sharp-pointed teeth. The nervation consists 

of a rather strong midrib and several pairs of 

·alternate thin secondaries which arise at a low 

angle and arch and join well inside the margin, 

sending branches from the outside to the marginal teeth. There are a few intermediate secondaries. The nervilles ar~ numerous, rather 

strong, and usually broken, forming irregular 

areas. 

This leaf, although a mere fragment, is so 

entirely distinct from any other focm found in 

these beds that it merits recognition. 

Occurrence: Frontier formation, 1 mile east 

of Cumberland, Wyo. Collected by F. H. 

Knowlton and T. W. Stanton in 1908. 

Phyllites sp. 

Plate XXXV, :figure 4b. 

The basal portion of the leaf here figured 

seems to represent a very distinct form that can 

probably be recognized if found in the future. 

It appears to have been ovate, the base at first 

abruptly rounded, then projected downward 

into a wedge-shaped portion. The rather 

slender, curved petiole is apparently complete. 

The margin is entire. The nervation consists 

of a rather slender midrib, a pair of very slender 

secondaries just above the basal margin of the 

blade, and a pair of opposite secondaries some 

distance above the base. These upper secondaries, or perhaps ((ribs," have branches on the 

outside that curve upward along. and perhaps 

end in the margin. These "ribs" do not join 

with the midrib where they come into contact 

with it but are distinct and run down along the 

midrib almost to the base of the leaf. The finer 

nervation can not be made out with certainty. 

Occurrence: Frontier formation, 1! miles 

south of Cumberland, Wyo., in the SE. 1 sec. 

6, T. 18 N., R. 116 W. From same horizon as 

plant beds 1 mile east of Cumberland. Colle"ted by T. W. Stanton September 1, 1913. 

FORMS EXCLUDED FROM THJS FLORA. 

· Genus TRICHOPTERIS. 

Trichopteris filamentosa Hall, in Fremont, op. cit., Appendix B, p. 306, pl. 2, :fig. 6, 1845. 

Trichopteris gracilis Hall, idem, p. _307, pl. 1, :fig. 5. 

This genus with two species was established 

by Hall, but clearly the forms are only rootlets 

of ferns. 

Phyllites .fremonti Unger. 

Phyllites jremonti Unger, Genera et species plantarum 

fossilium, p. 503, 1850. Leaf of a dicotyledonous 

plant (?) Hall, in Fremont, op. cit., Appendix B, 

p. 307, p. 2, :fig. 4, 1845. 

There is much doubt about the propriety of 

ineluding this species in the present flora. 

It waf:i placed by Hall at the ·end of the description of this flora, with the following 

remarks: 

Locality in the neighborhood of the specimens containing the preceding fossils and regarded by Capt. Fremont as belonging to the same formation. The rock containing them is a soft or very partially indurated clay, 

very unlike the hard and brittle mass containing the 

other· species. 

The probability that it did not come from 

the vicinity of the Cumberland locality is 

further strengthened by the chance statement 

"Fr.· Aug. 17, and No. 201' of collection," 

which appears to. mean that it was collected on 

Friday August 17, whereas the others are recorded ' under the date of August 19. F 1 re-~ 

mont's itinerary for the earlier date 1 indicates 

that on that day the expedition encamped on 

Blacks Fork of Green. River, some 40 miles 

east, of the locality reached on August 19. In 

the low hills bordering the stream he found 

((strata containing handsome and very distinct vecretable fossils." This locality is presulnably0 in the Green River formation, and if 

the above reasoning is correct, it apP,ears to 

dispose of the reference of this species to . the 

Colorado flora under consideration. The type 

specimen is now lost, and hence it is impossible 

to study the 1natrix in which it was preserved. 

This leaf was named and described by Unger 

as Phyllites fremonti,· from Hall's figu~e~ an_d 

Unger fell into the usual error of ascnb1ng 1t 

to Oregon, as the expedition went to "Oregon 

and north California." The above history has 

been given at some length for the purpose ~f 

settincr forth the unsatisfactory status of this 

specie~ and thus preventing future misunderstanding. 

1 Fremont, J. C., op. cit., p. 130. 
PLATES XXVIII-XXXIX. 

95 
PLATE XXVIII. 

FIGURES 1-4. Tapeinidium1 ' undulatum (Hall) Knowlton, n. comb. ________ __________________________ _ 

2a. Pinnules from figure 2, enlarged about three and one-half times to show nervation. __ . ___ _ 

96 

Page 

80 

80 
U. S. GEOLO(,liCAL SURVEY PROFESSIONAL PAPER 108 PLATE XXVIII 

1 

2a 

3 

4 

2 

FOSSIL FLORA FROM THE FRONTIER FORMATION. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XXIX 

3 

4 

FOSSIL FLORA FROM THE FRONTIER FORMATION. 
PLATE XXIX. 

Page. 

FIGURES 1-4. Microtaenia variabilis Knowlton, n. sp .. _________________ . _____ . ___ . __ . ___ .. _ .............. _... 81 

4a. Uppermost pinnule in figure 4, enlarged three times to show nervation and sori. _. ___ . _____ ____ . 81 

~7 
PLATE XXX. 

Page. 

FIGURES 1, 2. Microtaenia paucifolia (Hall) Knowlton, n. comb.............................................. 82 

3, 4. Dryopteris coloradensis Knowlton, n. sp ......... _... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 

5. Dennstaedtia? fremonti (Hall) Knowlton, n. comb .................................. -........... 83 

98 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XXX 

3 

FOSSIL FLORA FROM THE FRONTIER FORMATION. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XXXI 

2 

5 

FOSSIL FLORA FROM THE FRONTIER FORMATION. 
PLATE XXXI. 

Page. 

FIGUR E l. Dennstaedtia? fremonti Knowlton, n. sp ..... . ................. .. .............. . . . ..... . ... . . _... . 83 

2-5. Asplenium occidentale Knowlton, n. sp... . ...... ... ................. . ........................... 84 

6. Anemia (remonti Knowlton, n. sp ................ .....•••................ ~....... ......... ..... 84 

99 
PLATE XXXII. 

Page. 

FIGURES 1-3. Anemia fremonti Knowlton, n. sp. _______ __ ____ ___ __________ _______________________ . _......... 84 

4, 5. Staphylea f fremonti Knowlton, n. sp .............. ___ . ___ .... _ ............... __ . . . _ . _ . . . . . . . 93 

100 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XXXII 

4 

1 

FOSSIL FLORA FROM THE FRONTIER FORMATION. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XXXIII 

1 

3 

4 

6 

5 

FOSSIL FLORA FROM THE FRONTIER FORMATION. 
PLATE XXXIII. 

Page. 

FIGURE 1. Smilax? coloradensis Knowlton, n. sp. ______ . ___ . _. _____________ ........ _______ . _______ .......... 85 

2-4. Quercus stantoni Knowlton, n. sp. ____ . ___ .. _ .. _______________ __ __ ... _____ . __ . _. ______ .. . ....... 86 

5. Leaflet of Staphylea? fremonti, showing mine of microlepidopterous larva. ____ .... __ . . . . . . . . . . . . . . 93 

6. Equisetum sp ................................•.•.•..••.•.•.•...•................. ____ ......... 85 

101 
PLATE XXXIV. 

Page. 

FIGURE 1. Myrica nervosa Knowlton, n. sp. ____________ ~ ______________________________ . __ .. __ ...... _ . . . . . . . 85 

2, 3. F'ieusf sp ___ . _ ..... _. _. _. _. _. _. ___ . ____ . ____ . _. _. _. _. ___ . _________________________ . ___ . ____ .. 88 

4-6. F'icus (remonti Knowlton, n. sp _ ... _ . _ . _____ . ___ . _ . _______ . __________________________________ . . 87 

7. Dryandroides lanceolata Knowlton, n. s:;:> _____________ . _ . ____________________________________ __ _ . 89 

8. Phyllites dentata -Knowlton, n. sp . _. _. ___ .. __ . _ ... _. _______ . __ . ___ . _. ___ ... ___ . __ .. ___ . ___ .. _.. 94 

102 
U. S. GEOLOGICAL SURVEY PROFESS!ONAL PAPER 108 PLATE XXXIV 

6 

7 8 

5 

FOSSIL FLORA FROM THE FRONTIER FORMATION. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XXXV 

1 2 

4 

3 

FOSSIL FLORA FROM THE FRONTIER FORMATION. 
PLATE XXXV. 

Page. 

FIGURE 1. FU:u~J'! sp ................................ _ . _ . _ ... . . . . __ . _ ... __ ... _ . _ ... . ..... _ ... _ . . . . . . . . . . . . . 88 

2. Cinnamomum? sp ........................ _ . _ . _ . _ .. __ . _ . . . . ___ . _ . . . . . . . . . . . . . . . . . 89 

3. Phyllites fidfolia Knowlton, n. sp . .............. __ . _ _ . . . . . . . . . . . . . . . . . . . . . . . . 93 

4a. Salix jrontierensis Knowlton, n. sp .............. _ .. _ . . _ _ . . . . . . . . . . . . . . . . . . . . . . . . 86 

{b. Phyllites sp ........................ . ... . . . . _ . . . . . . . _ . . . . . . . . . . . . . . . . . . . . . . . 94 

4c. Ficus jremonti Knowlton, n. sp ............ _ ... _ . _ . _ ... _ .... ............ ........ : . . . . . . . . . . . . . . . . 87 

5. Leaf of FU:us.fremonti Knowlton, twice natural size, to show egg mass of microlepidopterous insect.. 87 

103 
PLATE XXXVI. 

Page. 

FIGURES 1-3. Dewalquea pulchella Knowlton, n. sp ....... . ....... : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 

4. Aralia veatchii Knowlton, n. sp........ . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 

104 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XXXVI 

FOSSIL FLORA FROM THE FRONTIER FORMATION. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XXXVII 

1 

FOSSIL FLORA FROM THE FRONTIER FORMATION. 
PLATE XXXVII. 

Page. 

FIGURES 1-3. Dewalquea pulchella Knowlton, n. sp ........... _. __ ... _.. ........................... .. . . . . . 90 

4. Aralia veatchii Knowlton, n. sp.. . . . . . .. . . . .. . . .. .. .. .. .. . . .. . . .. . • . .. • . . . . .. .. . . . . . . .. . . .. 92 

105 
PLATE XXXVIII. 

Page. 

FIGURE 1. Aralia veatchii Knowlton, n. sp............................................................... 93 

2. Cinnamomum hesperium Knowlton, n. sp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 

3. Salix cumberlandensis Knowlton, n. sp......................................................... 86 

106 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XXXVIII 

2 

1 3 

FOSSIL FLORA FROM THE FRONTIER FORMATION. 
U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XXXIX 

FOSSIL FLORA FROM THE FRONTIER FORMATION. 
PLATE XXXIX. 

Page. 

Aralia veatchi,i Knowlton, n. sp ...... __ .. _ .. ____ ......... _ .. _____ ..................................... 92 

107 

0 
DEPARTMENT OF THE INTERIOR 

FRANKLIN K. LANE, Secretary 

UNITED STAT-ES GEOLOGICAL SURVEY 

GEORGE OTIS SMITH, Director 

Professional Paper 108-G 

ORBITOID FORAMINIFERA· OF THE GENUS ORTHOPHRAGMINA · 

FROM GEORGIA AND FLORIDA 

P APERS BY 

c. w. GOOKE AND J. A. CUSHMAN 

Published December 12, 1917 

Shorter contributions to general geology, 1917 

(Pages 109- 124) 

WASHINGTON 

GOVERNMENT PRINTING OFFICE 

1917 
CONTENTS. 

The stratigraphic position and faunal associates of the orbitoid Foraminifera of the genus Orthophragmina from 

G;~:::d~~~i:~~~~~~'.' ~:. ~-. ~ ~ ~~~~~ .·. ·_ ·_ ·_ -_ ~- ·_ ·_ ·. ·. -. ·. ·. ·. ·_ ·_ ·_ ·_ ·_ -. ·_ -. ~ -- ·_ ·_ ~ ~ ~ -_ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~- ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ::: ~ ~: ~ ~ ~ Localities on Chipola River ......... _ ..... : ........................ ~ ............... , ................ . 

Localities on Flint River ...... : ............................. -............. " .... -... . .... _ .... -.......... . 

Lo~ality on Suwannee River ...•....... _ ... _ .... __ . __ .... _ .. --._ ......... _ ..... _ .. _ .. : __ ._ .. : ...... _ .. 

Faunal associates of species of Orthophragmina .. ........................... . ..... : . ................... . 

Orbitoid Foraminifera of the genus Orthophragmina from Georgia and Florida, by J_ A. Cushman ............ . 

ILLUSTRATIONS. 

Page. 

109 

109 

109 

110 

112 

112 

115 

Page. 

PLATES XL-XLIV. Species of Orthophragmina~ .......... ....................................... ~ ... , . . . . 119-124 -

FIGURE 19.· Map showing positionjof stations on Chipola River, Fla., and Flint River, Ga., at which specimens 

- of Orthophragmina were collected ................ , .............. _ .. : ............... •.. . . . . . . . . . 111 

20. Map showing position of station 7348, Troy Springs, on Suwannee River, Fla .. ,.................. 114 

II 
THE STRATIGRAPHIC POSITION AND FAUNAL ASSOOIATES OF' THE 

ORBITOID FORAMINIFERA OF THE GENUS ORTHOPHRAGMINA· FROM 

GEORGIA ·AND FLORIDA. I-; 

. ' 

By CHARLES WYTHE CooKE. 

INTRODUCTION. obtained at the other localities cited 1n this 

The present short paper is designed to fur- paper. . . 

nish information regarding the stratigraphic The follq~1ng IS a. list of the species of 

relations of the species of Orthophragrnina de- Or_thophragm~n:a described by Mr. Cushman, 

scribed by Mr. Cushman in the succeeding w1t~ the station numbers of the localities at 

paper and to enumerate the other organisms whwh they were found: 

found in association with them, and therebly Orthophragmina jlintensis Cushman, n. sp. 7115, 7116, 

make evident the value of these species in the 7117., 7119, 7237 · 

investigation of problems of geologic corre- Orthophragmina jloridana Cushman, n. sp. 6768. 

Orthophragmina americana Cushman, n·, sp. 3387, 6768. 

lation. Evidence, chiefly paleontologic, pre- Orthophragmina mariannensis Cu,shman, n. sp. 3387, 

sented in a recent paper 1 in my opinion shows 6768. 

that the Ocala limestone is of upper Eocene Orthophragmina mariannensis var. papillata Cushman, 

age. , The occurrence of Orthophragmina at n. var. 6768, 7126, 7129~, 7191,, 7192. 

Orthophragmina . georgiana, Cushman, · n. sp. 3387, 

numerous exposures which are referred to the 7097, 7099, 7126, 734.s. 

Ocala on the basis of physical and faunal Orthophragmina vaughani Cushman, n. sp. 3387. 

resemblance is in accord with the deduction 

from other paleontologic data and corroborates 

the reference to the upper Eocene of the part 

of the formation i:p. which they are found. · 

The orbitoid Foraminifera described by Mr. 

Cushman in the accompanying paper were 

LOCALITIES ON CHIPOLA RIVER. 

Stations 6768, 7191, 7192.-The following 

sections at Marianna are quoted from my paper 

on the age 'of the Ocala-li~estone: 2 

obtained from the Ocala limestone in three Section on the west bank of Chipola River at the wagon 'bridge 

regions-on Chipola River at Marianna, Jack~ one-haljmile .east of Marianna, Fla. 

son County, Fla.; at several localities on Flint Marianna limestone: Feet 

River, Ga., between the crossing of the Sea-: 

board Air Line Railway in Sumter County, 

about 8 miles west of Cordele, and Bainbridge, 

Decatur. County; and ·on Suwannee River in 

Suwan~ee County, Fla. The positions of the 

stations have been plotted on th!e maps, text~ 

figures 19 and 20. Some of these occurrences 

are believed to represent the upper part of . 

the Ocala limestone, but the exact stratigraphic position of most of them in the formation has not been definitely ascertained. The 

collections obtained on Flint River above 

Albany (characterized by the presence of 

Orthophragmina jlintensis Cushman) represent 

a horizon lower in the formation than those 

1 Cooke, C. W., The age of the Ocala limestone: U. S. Geol. Survey· 

Prof. Paper 95, pp. 107-117, 1915. 

5. Alternating hard and softer beds of lightcolored limestone, very hard and compact 

in places, locally -semicrystalline. The 

lower portion contains a considerable 

amount of glauconite. The upper portion 

has been quarried for building stone and 

contains Orbit-oides, Pecten poulsoni (var. ?), 

Clypeaster rogersi, and casts of other fossils. 

The floor of the bridge is 9 feet above the 

base of this bed._.. . . . . . . . . . . . .. . . . . . . . . . . . 33 

Ocala lilp.estone: . 

4. Concealed ...................•.•..... .; . . . . . . . 3 

3. Hard creamy-white semicrystalline limestone~ 

apparently a more indurated phase of bed 

No. 1. Contains Orbitoides (stellately 

marked species), Area, Glycymeris, Amusium 

ocalanum, Plicatula (Ocala species), Venericardia ........... .................. ~ . . . . . . . ll 

2. Concealed .............................. :.... 4 

· 2 Idem, p: 109. 

109 
110 SHORTER CON'rRIBUTIONS TO GENERAL GEOLOGY, 1917. 

Ocala limestone-Continued. Feet. _ 

1. Soft cream-colored porous limestone or marl, 

composed largely of Foraminifera loosely 

·packed together. Contain~;~ Nummulites, 

Orbitoide8 (stellately m~ked species), Bryozoa, Amusium ocalanum,-Cardium. Extends 

beneath water in the river.. . . . . . . . . . . . . . . . 5 

The intervals concealed at the bridge are exposed near 

the mouth of the cavern about 200 yards below the bridge, 

where the following supplementary section was observed: 

Section "200 yards below the wagon bridge east of Marianna, 

· Fla. ' 

Marianna limestone: ' Feet . 

. 5. White limestone, the ,same as bed No.5 of the 

section at the bridge. . . . . . . . . . . . . . . . . . . . . . 33 

Ocala limestone. _ 

4. Soft cream-colored limestone with several 

species of Orbitoides_ and some Bryozol}. . . . . . 1 -

3. Hard semicrystalline pinkish limestone with 

.large Orbitoides, Flabellum, and Amusium 

ocalanum.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6! 

2. Soft granular cream-colored limestone, much 

like No. 1 ofsection at bridge but with fewer 

Foraminifera. Contains Orbitoides (stel- . 

lately marked species)~ Flabellum, Bryozoa, 

Terebratulina lachryma?, Natica, Area, 

Pecten indecisus, Amusium ocalanum, and 

Plicatula (Ocala species)................... 3 

1. Concealed to wate! level in Chipola River. . . . 3 

From bed 1 .of the first section (station 6768) 

Mr. Cushman records Orthophragmina floridana, 0. americana, 0. mariannensis, and 

0. mariannensis var. papillata. The la,c;;tnamed variety occurs also in bed 3 . of ·the first 

section (station 7192) and in bed 2 of the 

second section (station 7191). 

LOCALITIES ON ~INT RIVER. 

Station 72.~7~-Small quarry_on the Averitt 

property, 300 or 400 yar~ southwest of the 

corner of lots 7 and 26, half a mile east of 

Hugenen Ferry and 1 mile south of Daphne 

station, Crisp County. 

The rock at this locality is _a soft white 

limestone containing Orthophragmina fiintensis 

· Cushman, numerous Bryozoa, and an undetermined pecten, pro~ably Amusium ocalanum 

(Dall). An analysis of the limestone fron1 

. this locality given by Brantley 1 shows 85 per 

cent calcium carbonate. Better . exposures of 

this rock occur in a sink about 300 yards east 

of the quarry, where 23 feet of soft argillaceous 

white limestone containing small specks of 

glauconite is overlain by 18 feet of reddish 

sandy loam. The course of an underground 

stream that flows through this sin~ can be 

i. Brantley, J. E., Limestones and marls of the Coastal flain of Georgia: 

Georgia Geol. Survey Bull. 21, p. 158, 1916. 

traced northwestward by means of long, 

narrow, slot-shaped sinks whi,ch expose it at 

intervals to Gum Ci·eek. 

Station 7115.-East bank of Flint River at 

bend to west 6 miles below Burke Ferry and 

ab~ut 6 miles above the bridge of the Georgia 

Southwestern & Gulf Railway near Warwick, 

Worth County. ' 

The material exposed -consists of white, 

compact limestone rising 5 feet above water 

level and overlain bv flint boulders, sand, and 

gravel. Orthophrag::nina fiintensis and Ope1'-

culina sp. were collected here. - _ 

Stations 7116, 7117.-Bluff on the west bank 

of Flint River about 1! miles above the bridge 

of the Georgia Southwest~rn & Gulf Railway 

near Oakfield . 

The section 'at this locality is as follows: 

Section o~ Flint River near Oakfield. Feet. 

3. Covered slope to top of hill...................... 22 

2. Hard ledges of compact white semicrystalline 

limestone (station 7117)........................ 3 · 

1. Compact white limestone, mostly soft but with 

harder places. Contains _ (station 7116) Orthophragmina .ftintensis and Laganum? trustuloides 

(Morton)? To water level at 4-foot stage...... '20 · 

From bed 2. were collected the following: 

Foraminifera: 

Orthophragmina flintensis Cushman. 

Bryozoa: 

Several specie~. 

Echinodermata: 

. Laganum? crustuloides (Morton)? , 

Mollusca: 

Ostrea sp. 

Pecten perplanus Merton. 

Pecten suwaneensis Dall. 

Station ?'119.-East bank of Flint River, 

about 16 miles above Albany, in Worth County, 

near the Dougherty County line. 

The rock here consists· of 5 feet of limestone, 

the upper part white, and the lower part gray, 

overlain by flint fragments. It contains 

Orthophragmina jlintensis· Cushman, Operculina 

sp., and Pecten suwaneensis Dall . 

Station 7126.-East bank of Flint ·River at 

Dry Bread Shoals, Mitchell County, .8! or _ 9 

rriiles below Newton. 

The following species were collected from 

lumps- of hard limestone . excavated from the 

channel: 

Foraminifera: . 

Orthophragmina manannensis v:ar. papillata Cusl:-

man. 

Orthophr3.oomina georgiana Cushman. 
OR.BITOID FORAMINIFERA FROM GEORGIA AND FLORIDA. Ill 

Anthozoa: 

Trochoseris :n. sp. · 

Echinodermata: 

Cidaris georgiana Twitchell. 

Laganum? crustuloides (Morton)? 

Oligopygus haldermani (Conrad). 

Mollusca: 

Mitra sp. 

Chamasp. 

Limo psis sp. 

Barbatia sp. 

Mollusca-Continued. 

Ostrea trigon~lis Conrad. 

Amusium ocalanum (Dall). 

Pecten perplanus Morton. 

Spondylus sp. 

Plicatula, Ocala sp. 

Mya? sp. 

Venericardia vicksburgiana Dall. 

Venericardia sp. 

Crassatellites sp. 

Scale l. oo~ ooo 

leocs~~~oE===·===·~1~o=======~2o~s 

FIGURE 19.-Mapshowin~ position of stations on Chipola River, Fla., and Flint River, Ga., at which spe9imens of Orthophragmina were _collected. 

Station 7129.-East bank of Flint River 1 

mile below Windell's Landing and about 15 

miles above Bainbridge, in Decatur County. 

Orthophragm~na mariannensis var. papillata 

Cushman and an undetermined species of 

Pecten were found in 5 feet of irregularly 

weathered pinkish limestone. 

Stations 3387, 7097, 7099.-Species of Orthophragmina have been obtained from the Ocala 

limestone at three localities near Bainbridge, 
112 SHORTER CONTiiiBUTIONS TO GENERAL GEOLOGY, 1917 .' 

the stratigraphic relations of which are nearly 

identical. The 09ala ·limestone is the oldest 

formation in the vicinity of Bainbridge, and 

all the exposures of it · appear to represent a 

single horizon. It is a soft, . coarsely granular 

white to yellow limestone and is composed 

largely of ·tests of Foraminifera and Bryozoa, 

'Yhich on·exposed surfaces have become firmly 

cemented or "casehardened" into a brittle 

semicrystalline · limestone ·-t>ut which when 

freshly exposed are only sligh-tly coherent. 

The rock appears to lie very nearly horizontal, 

but the -upper surface is exc~edingly irregular 

~nd jagged;with.pinnacles extending in places 

to 20 feet above'water level. · The irregularity 

is due in part to erosion prior to the deposition 

of the overlying rna terials- and in part to 

subsequent solution. 

The Ocala is overlain unconforn1ably by a 

complex series of red and variegated sands and 

carbonaceous clays containing chert fr~gments 

with impressions and siliceous pseudomorphs 

of mollusks and corals of earliest Chattahoochee 

age. The Ocala itself appears to have been 

· subjected in less degree to the silicifying 

agencies, for chert fragments carrying Ocala 

fossils are occasionally found. The accidental 

inclusion of some of these fragments· in the 

collections of the coralliferous . chert has "!lnfortunately been interpreted as a mingling of 

the Ocala and Chatt.ahoochee faunas. 1 

The following species have been identified in 

the Ocala limestone from localities near 

Bainbridge: 

Station 7099. East bank of Flint River, half a mile above 

Red Bluff: ' 

Foraminifera: 

Orthophragmina georgiana Cushman. 

Bryozoa: 

Many species. 

Echinodermata: 

- Oligopygus haldermani (Conrad). 

Agassizia conradi (Bouve). 

Stations 3387, 6159, 7098. Red Bluff, Flint River, 7 miles 

above Bainbridge: 

Foraminifera: · 

Orthophragmina americana Cushman. 

Or.thophnigmina mariannensis Cushman. 

Ortbophragmina georgiana Cushman. 

Orthophragmina vaughani Cushman. 

Bryozoa: 

Many species. 

Echinodermata: 

Oligopygus haldermani (Conrad). 

Laganum? crustuloides (Morton)? 

Cassidulus (Pygorhynchus) georgiensis TwitchelL 

Agassizia conradi (Bouve). 

1 Dall, W. H., A contribution to the invertebrate fauna of the Oligocene 

beds of Flint River, Ga.: U.S. Nat. :M:us. Proc., vol. 5t, p. 488, 1916. 

Station3387, 6159,7098, Red Bluff, Flint River, etc.~Con. 

Moilusca: · 

Pecten perplanus Morton. 

_Pecten indecisus Dall. 

Pecten suwaneensis Dall. 

Amusium ocalanum (Dall}. 

Station 7097.-Bluff on east bank of Flint 

River near the old ·'factory three-fourths mile 

northeast of the Atlantic Coast Line Railway 

station at Bainbridge: 

Foraminifera: :::-:'~ 

Orthophragm:in~ georgiana Cushman and many 

others. . 

Bryozoa: 

About 34 species, most of them new. ; 

. Echinodermata: 

Cidaris georgiana Twitchell. 

Cassidulus (Py-gorhynchus) conradi (Conrad). 

Oligopygus haldermani (Conrad). 

Agassizia conradi (Bouve). 

Eupatagus carolinensis Clark? 

Mollusca: 

Ostrea,·2 sp. 

·Pecten perplanus Morton. 

Amusium ocalanum (Dall). 

Pijcatula, Ocala sp. 

Cardium sp. ' 

LOCALITY ON SUWANNEE RIVER. 

Station 7348._:_Left bank of Suwannee River 

84! miles above its mouth, 9 miles above 

Branford, and · · about 1 mile above Troy 

Springs. (See fig. 20.) . 

There is at this place a small exposure of 

cream-colored orbitoidal limestone containing 

Orthophragmina georgiana Cushman, Pecten 

perplanus Morton, -·and Pecten ind~cisus Dall. 

The exposure is believed to represent a horizon 

well _up in the Ocala limestone but not the 

topmost. · · 

FAUNAL ASSOCIATES OF SPECIES OF ORTHOPHRAGMINA. 

The species which hav:e been found associated with each species of Orthophragmina 

are listed below: · 

Orthophragmina fiintensis Cushman. . 

Operculina sp. 

Lagan urn? crustuloides (Morton)? 

Ostrea sp. 

Pecten perplanus Morton. 

Pecten suwaneensis Dall. 

A':musium ocalanum (Dall). 

Orthophragmina fioridana Cushman. 

Orthophragmina americana Cushman. 

Orthophragmina mariannensis Cushman. 

Orthophragmina mariannensis var. papillata Cushman. 

. Flabellum sp. 

Terebratulina lachryma (Morton)? 

Pecten indecisus_ Dall. 

Amusium ocalanum (Dall). 

Plicat_ula, Ocala_sp . . 
ORBITOID FORAMJNIFERA FROM GEORGIA AND FLORIDA. 113. 

Orthophragmina americana Cushman. 

Orthophragmina fioridana Cushman. 

Orthophragmina mariannensis Cushman. · 

Orthophragmina mariaimensis var. pap illata Cushman. 

Orthophragmina georgiana Cushman. 

Orthophragmina vaughani Cushman. 

Flabellum sp. 

Oligopygus haldermani (Conrad). 

Laganum? crustuloides (Morton)? 

Cassid ul us (Pygorh ynchus) georgiensis T'vi tchel1. 

Agassizia comadi (Bouve). 

Terebratulina lachryma (Morton)? 

Pecten indecisus Dall. 

Pecten perplanus Morton. 

Orthophragmina mariannensis Cushman-Continued. 

Terebratulinalachryma (Morton)? 

Pecten indecisus Dall. 

Pecten perplanus Morton. 

Pecten suwaneensis Dall. 

Amusium ocalanum (Dall). 

Plicatula, Ocala sp. 

Orthophragmina mariannensis var. papillata Cushman. 

Orthophragmina mariannensis Cushman. 

Orthophragmina floridana Cushman. 

Orthophragmina americana Cushman. 

Orthophragmina georgiana Cushman. 

Flabellum sp. 

Trochoseris ri. sp. 

Cidaris georgiana Twitchell. 

Oligopygus haldermani (Conrad). 

Laganum? crustuloides (Morton)? 

Terebratulina lachryma (Morton)? 

Pecten perplanus Morton. 

Pecten indecisus Dall. 

Amusium ocalanum (Dall). 

Spondylus sp. 

Plicatula, Ocala sp. 

Venericardia vicksburgiana Dall. 

Orthophragmina georgiana Cushman. 

Orthophragmina americana Cushman. 

Orthophragmina mariannensis Cushman. 

Orthophragmiil.a mariannensis var. pap illata Cushman. 

Orthophragmina vaughani Cushman. 

Trochoseris n:. sp. 

Cidaris georgiana Twitchell. 

Oligopygus haldermani (Conra>f). 

Laganum? crustuloides (Morton)? . 

Cassidulus (Pygorhynchus) conradi (Conrad). 

Cassidulus (Pygorhynchus) georgiensis Twitchell. 

Agassizia conradi (Bouve). 

Eupatagus carolinensis Clark? 

Ostrea trigonalis Conrad. 

Pecten suwaneensis Dall. 

Pecten perplanus Morton. 

FIGURE 20.-Map showing position of station 7348, Troy Springs, on Suwannee Pecten indecisus Dall. 

Amusium ocalanum (Dall)r 

Spondylus sp. 

River,Fla. · 

Pecten suwaneensis Dall. 

Amusium o<;alanum (Dall). 

Plicatula, Ocala sp. 

Orthophragmina mariaimensis Cushman. 

Orthophragmina floridana Cushman. 

Orthophragmina americana Cushman. 

Orthophragmina mariannensis var. papillata Cush- man. · 

Orthophragmina georgiana Cushman. 

Orthophragmina vaughani Cushman. 

Flabellum sp. 

Oligopygus haldermani (Conrad). 

Laganum? crustuloides (Morton)? 

Cassidulus (Pygorhynchus) georgiensisTwitchell. 

Agassizia comadi (Bouve). 

Plicatula, Ocala sp. 

Venericardia vicksburgiana Dall. 

Orthophragmina vaughani Cushman. 

Orthophragmina georgiana Cushman. 

Orthophragmina americana Cushman. 

Orthophragmina mariannensis Cushman. 

Oligopygus haldermani (Conrad). 

Laganum? crustuloides (Morton)? 

Pecten perplanus Morton. 

Pecten indec!sus Dall. 

Pecten suwaneensis Dall. 

Amusium ocalanum (Dall). 

Cassidulus (Pygorhynchus) georgiensis Twitchelt 

Agassizia conradi (Bouve). 

ORBITOID · FORAMINIFERA OF THE GENUS ORTHOPHRAGMINA FROM. 

GEORGIA AND FLORIDA 

By JosEPH AuGusTINE CusHMAN. 

The larger orbitoid Foraminifera of theW estern Hemisphere are very inadequately known, 

yet their occurrence in great numbers has been 

noted in many papers during the last threequarters of a century. Lepidocyclina mantelli 

(Morton), the type species of that genus, was 

described by Morton in 1833. 

As now known the. orbitoid Foraminifera 

found in beds below the Miocene are grouped 

largely · in three genera, the grouping depending upon the internal structure of the test. In 

these gro-q.ps there is a central plane of chambers, known technically as ''equatorial chambers,"· and a mass of more irregularly placed 

chambers on each side, making up the thick-

' ness of the test, known ·as "lateral chambers." 

In transverse (\ertical) section the equatorial 

chambers show slight differences, but when 

cut horizontally, or in the plane in which they 

lie, those of Lepidocyclina typically have a 

hexagonal form, those ·of Orthophragmina are 

elongated_rectangular, and those of Orbitoides 

are diamond shaped. Because in general Orbitoides, with s·ome modifications to be noted 

in a future paper, is Cretaceous, 01thophragmina Eocene, and Lepidocyclina Oligocene, 

much importance is attached to these organisms in the investigation of problems of geologic correlation. 

The specimens described here belong to the 

second of the genera mentioned, Orthophragm,ina. Although not limited to this genus, the 

stellate form or stellate1y marked surface is 

rather characteristic of a number of the species. Bagg 1 and Cooke 2 have referred to 

"stellately marked" orbitoid Foraminifera, all 

of which have proved on examination to be 

Orthophragmina. Two of the species here det Veatch, Otto, and Stephe:rison, L. W., Preliminary report on the 

geology·Df the Coastal Plain of Georgia: Georgia Geol. Survey Bull. 26, 

p. 320, 1911. Identification by R. M. Bagg. 

2 Cooke,. C. W., The age of the Ocala limestone: U. S. Geol. Survey 

Prof. Paper 95, p. 109, 1~15. 

100605°-17-2 

scribed are circular and not stellately marked, 

but the others are distinctly stellate, either in 

form or markings. 

After a ~areful study of the species all seem 

to be new, although one or two of them are 

somewhat related to certain European species, 

as is noted in the descriptions. The specimens as a rule occur in soft chalky limestone 

and do not section well to show the .finer structure of the interior. 

Data in regard to material are included in the 

description of each species. 

Orthophragmina flintensis Cushman, n. sp. 

Plate XL, figures 1, 2. 

Test small, circular, about 5 millimeters in 

diameter; central portion thickened, gradually 

sloping to the periphery; surface slightly pustulate l:Yut not papillate, almost smooth, the raised 

pustules generally in· concentric lines. 

· Horizontal section shows very narrow rectangular equatorial chambers and the embryonic chambers consisting of a small circular 

chamber nearly surrounded by ·the elongate 

second chamb<er (Pl. XL, fig. 2) . . 

Type specimen from U. S. G. S. collection 

7117, from Ocala limestone in bluff on west bank 

of Flint River 1 t miles above the Georgia Southwestern & Gulf Railway bridge near Oakfield, 

Lee County, Ga.; upper bed, No.2 of section; 

C. W. Cooke, collector. 

Other specim'ens of this same species from 

the Ocala limestone are in collections 7116,. 

same locality, No.1 of section; 7115, east bank 

of Flint River at bend to west 6 miles below 

Burke . Ferry and about 6 miles above the 

Georgia Southwestern & Gulf Railway bridge 

near Warwic~, Worth County, Ga., C. W. 

Cooke, collector; 7119, east bank of Flint 

River about 16 miles above Albany, in Worth 

Co~nty 1 Ga., C. W. Cooke, collector; 7237, 

115 
116 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

small quarry on Averitt plantation, 300 or 400 

yards southwest of corner of lots 26-27' and . 

~nlf a mile east of Hugenen Ferry, Crisp 

vounty, Ga.; C. W. Cooke and J. E. Brantley, 

collectors. 

Material from station 7237 may possibly not 

be the same, but the horizontal section, which 

alone was visible, is very similar. The species 

seem to be fairly common in the fine-~ained 

white Ocala limestone .along Flint River at 

these localities. 

Orthophragmina floridana Cushman, n. sp. 

Plate XL, figure 3. 

Test circular, much flattened, of ll\edium 

size, 10 to 14 millimeters in diameter, central 

region very slightly raised and uinbonate, thence 

flattened to the periphery, whole test very 

thin; surfac~ ornamented . throughout with 

fine but distinctly 'raised papillffi almost 

spinose, arranged in concentric, lines . parallel 

with the peripheral margin. 

. Equatorial chamb~rs in horizontal section 

very narrowly rectangular. 

Type specimen from U. S. G. S. collection 

6768, from 'Sof~ white Ocala limestone on Chipola River at wagon bridge half a mile east of 

·Marianna, Fla.; No.1 of section; C. W.Cooke, 

collector. This species is abundant at this 

locality. . 

In many respects this· species resembles 

0. archiaci Schlumberger, but it is a little 

larger and more flattened, and · its surface 

ornamentation is, somewhat different. It is 

evidently, however, an American relative of' 

this ·French species~ 

Orthophragmina americana Cushman, n. sp. 

Plate XL, figure 4; Plate XLI, figure 1; Plate XLII, 

figure 1. · , 

- Test large, as much. as 45 millimeters in 

diameter; peripheral margin with a series of 

projecting angles corresponding to the peripheral terminati9ns of the radiately arranged 

raised ornamentation or thickenings; peripheral 

.margin very thin, especi~lly at the reentrants 

between the projecting angles; central region 

with a· thickened umbo about 2 millimeters in 

diameter, from which radiate the thickened 

rib like raised areas rmining from the urn bo to 

the ends of the peripheral angles, highest near 

· the umbo and .decreasing in height and.increasing in· w·idth .toward the periphery; nearly 20 

radiating ribs in all, some startmg from the 

umbo, others initiated·1ater, not as branches of 

previous ones but arising in the intermediate 

area, usually more or' less irregular, the angle 

with the adjacent ones at either side not usually 

the same; surface comparatively smpoth, very 

slight traces of papillae, usually inconspicuous 

or lacking. . 

In vertical section the equatorial cham hers 

are rectangular, the area of the raised radial 

portions consisting of more ni.unerous lateral 

cham hers in the · columns, curving ·about the 

axis of the rib at either side, those of the intermediate depressed areas parallel with the equatorial belt of cham hers and fewer . in number. 

In horizontal section the equatorial chambers 

. are rectangular, four to five times as long as 

wide,· those of the axis of the radial portions 

narrower than ·those of the intermediate . 

depressed areas. 

·Type specimen from U. S. G. S. collection · 

6768, Ocala limestone on Chipola River at 

wagon bridge a quarter of a mile east of Marianna, Fla.; No.1 of section; C. W~ Cook~, collector. · 

A specimen referred to this species is from 

station 3387, Ocala lim~stone at Red Bluff, on 

Flint River 7 miles. above Bainbridge, Decatur 

County, Ga.; T. W. Vaughan, collector, 1900. 

In1 some respects this species resembles 0. 

patellaris Schlotheim, but it is nearly three 

times as large and has much finer and clearercut radial arms and smaller umbo as well as 

angular periphery. It is inore like 0. munieri 

Schlumberger, but . it is nearly four times as 

large and the number of ribs is greater and they 

do not branch as in 0. munie:ri. 

· 0. americana is ·one of the largest species of 

· the genus. 

Orthophragmina mariannensis Cushman, n. sp • . 

Plate XL, figu're 5; Plate XLII, figure 2; Plate XLIV. 

·Test flattened, conspicuouslystellate in outline, the angles extending out acutely with 

curved reentr-ants, or' medium. size, mostiy 1~ 

to 18 millimeters in diameter; .central region 

raised, umbonate, from which extend eight to 

eleven' (typically eight) raised rihs, running. to 

the peripheral angles; umbo and ribs finely 

papillate; . depressed. areas between, flat and 

rather remotely and finely papillate except 
·ORBITOID FOR.AMINilfERA FROM GEORGIA AND FLORIDA. 117 

toward the periphery, where the papillae are 

slightly more conspicuous. , 

Horizontal section showing much elongated, 

rectangular equatorial chambers, the lateral 

' chambers irregularly polygonal in section. 

Vertical section with the embryonic chambers very unequal, distinct pillars between the 

vertical rows of lateral chambers,-increasing in 

diameter peripherally. 

Type specimen from station 6768, Ooala limestone on Chipola River at wagon bridge half a 

mile east of Marianna, Fla.; No. 1 of section; 1 

C. W. Cooke, collector. Abundant. 

One sp'ecimen from U. S. G. S. station 3387, 

Ocala limestone at Red Bluff, on Flint River 

7 miles above Bainbridge, Decatur County, 

Ga.; T. W. Vaughan, collector, 1900. 

0. mariannensis . somewhat remotely re- . 

sem b les 0. lanceolata Schlum berger, but it is 

much larger and has a greater number of ribs, 

and its surface ornamentation is different. 

Orthophragmina mariannensis Cushman, n. sp., var. 

papillata <;ushman, n. var. 

Plate XLIII, :figure 1; Plate XLIV. 

Variety dli1ering frolll; the typical form of 

the species in the much more prominent, higher 

ribs, , which are semicylindrical and very 

strongly papillate; number of ribs also slightly 

greater than in the typical_ fo:r:m; a few specimens have 8, but 9 to 12 or even 16 ribs are 

more frequent. 

Occurs in Ocala limestor:e, with the typical 

form, at the type locaJity, U. S. G. S. station 

6768, on Chipo~a River at wagon bridge half a 

mre east of Marianna, Fla.; No. 1 of section; 

No.3 of section at station 7192; C. W. Cooke, 

collector. 

Specimens also from stations 7126, Ocala 

limestone, east bank of Flint River at Dry 

Bread Shoals, 8! or 9 miles below Newton, in 

Mitchell County, Ga., from lumps blasted from 

the channel, C. W. Cooke, collector; ar..9- 7129, 

Ocala limestone, east bank of Flint River a mile 

be~ow Windell's landing, about 6 miles above 

Red Bluff, Ga.; C. W. Cooke, collector. 

. There is a single specimen, an impression 

only, from station 7191, from Ocala limestone 

at mouth of small cavern about 200 yards southwest of briP,ge over Chipola River east of 

Marianna, Fla.; No.2 of section; C. W. Cooke 

and W. C. Mansfield, collectors. 

1 Cooke, C. W., The e of the Ocal~ limestone: U.S. Ceol. Survey 

;prof. Paper 95, p. 109, 1915. 

This variety for the most part is that referred 

to by Cooke in his paper cited above. It is 

recorded there under the name '' Orbitoides, 

stellately marked species." 

Orthophra~mina georgiana Cushman, n. · sp. 

Plate XLI, :figures 2, 3; Plate XLII, :figure 3; Plate XLIII, 

figUres 2, 3. 

Test typically almost square .in outlir:e, the 

angles slightly projecting and the sides slight:y 

concave near the angles, convex in tlie center, 

small; diameter usually about 6 millimeters for 

the adult specimens, diagonals of the square 

occupied, by raised radial areas with a eentra.l 

umbonate :~!lass of a little more than a millimeter in diameter, intermediate triangular areas 

flat and thin; entire surface with very r..umerous, evenly , distributed, prominent papillae, 

those of the central umbo and the middle line 

of the radial ridges slightly larger than those 

6f the rest of the surface. 

Type specimen from U. S. G. S. collection -

3387, Ocala limestone at Red Bluff, on Ffu:t 

River 7 miles above Bainbridge, Decat-cr 

County, Ga.; T. W. Vaughan, collector, 1900. 

It has also been collected in the Ocala limestone at the following stations: 7097, east 

bank of Flint River above the old factory, 

at bend three-quarters of a mile northeast 

of the Atlantic Coast Line Railway station 

at Bainbridge,, Ga., C. W. Cooke and W. C. 

Mansfield, collectors; 7099,· east bank of Fli.--:t 

River about half a mile above Red Bluff, De- . 

catur County, Ga., C. W. Cooke, collector; 

7126, east bank of Flint River at Dry Bread 

Shoals, 8! or 9 miles below Newton, in Mitchell 

County, Ga., from lumps blasted from the channel, C. W. Cooke,· collector; 7348, left bank of 

Suwannee Rive;r about a. mile above Troy · 

Springs, Fla., C. W. Cooke, collector. 

In its general form this species is very much 

like 0. ·stellata D'Archiac as figured by Schlumberger, but it does not seem to have the characteristic increase in width of the equatorial band 

of chambers toward the periphery inthe vertical section along the ray that occurs in that species. On the ~on trary, in 0. georgiana the equatorial chambers seem . to decrease in width toward the periphery, in this being more like those 

cf 0. lanceolata Schlum berger. In 0. georgiana 

also the radial ribs incline to a thickening in 

the center. 
11& SH ORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917 • . 

Orthophragmina'vaughani Cushman, n. sp. 

Plate XLIII, figures 4, 5. 

Test flattened, small; 8 to 10 millimeters in 

diameter, quadrate or octagonal in outline, stel-

, late; main ornamentation consisting of ~ central raised umbonate portion with four radiating raised areas to the main angles of the test, 

broad and rather low, about halfway to the periphery considerably increasing in height and 

width, finely papillate toward the center, much 

more _ coarsely so toward the periphery; inter-

. -

mediate spaces mucl~ depressed, with a smoqth 

U-shaped area near the inner angle next to the 

raised portions; the peripheral part raised and 

strongly papillate, the peripheral portion of this 

raised area 'at the margin strongly· convex or 

even bluntly angled.. . 

The ornamentation of this species is unique. 

Type specimen and others from U.S. G. S. 

station 3387, Ocala limestone, Red Bluff, ori 

Flint :River 7 miles above Bainbridge, Decatur County, Ga.; ~- W. Vaughan, collector, 

1900. 
PLATES XL-XLIV. 

119 
PLATE XL. 

Orthophragmina flintensis Cushman, n. sp. (p. 115). 

FIGURE 1. .Sectional View of type specimen, X 20, showing proloculum and second chamber which nearly encircles it, 

and the annular rings of narrowly rectangular chambers. U. S. G. S. station 7115. 

FIGURE 2. Accidental section of another specimen, X 20. U.S. G. S. statio~ 7119 . 

Orthophragmina floridana Cushman, n. sp. (p~ il6). 

FIGURE 3. Surface view of type spe_cimen, X 8. U.S. G. S. station 6768. 

Orthophragmina americana Cushman, n. sp. (p.ll6). 

FIGURE 4 .. Type specimen, X 4. Central portion prominently elevated. ·U.S. G. S. station 6768. 

Orthophragmina mariannensis Cushman, n. sp. (p. 116). 

FIGURE 5. Incomplete specimen, X 4. From Marianna, Fla. · 

120 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XL 

1 

3 

SPECIES OF ORTHOPHRAGMINA. 
U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XLI 

1 

2 3 

SPECIES OF ORTHOPHRAGMINA. 
PLATE XLI. 

Orthophragmina americana Cushman, n. sp. (p. 116). 

FIGURE 1. Surface view of a specimen, X 4, largely covered with an incrusting bryozoan. U. S. G."-8. station 6768. 

Orthophragmina georgiana Cushman, n. sp. (p. 117). 

FIGURE 2. Specimen viewed from the exterior, X 8. U.S. G. S. station 7097. 

FIGURE 3. Specimen with a more papillate surface, X 8. U. ~-G. S. station 7099. 

121 
. I 

' . 

PLATE 'XLII. 

Orthophragmina americana Cushman, n. sp. (~. 116). 

FIGURE 1. Surface view of one-half of-a very large specimen, X 4. U.S. G. S. station 3787. 

Orthophragmina marianneU:sis Cushman, n. sp. (p. 116). · 

FIGURE 2. Surface view of specimen, X 4. U. S. G. S. station 7191. 

Orthophragmina georgiana Cushman, n. sp. (p. 117). 

FIGURE 3. Portion of rock fragment with h~o specimens, the upper one much more papillate than the lower. U. S. 

G. S. station 7126. 

122 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XLII 

1 

2 3 

SPECIES OF ORTHOPHRAGMINA. 
U. S. GEOLOGICAL SURVEY PROF.ESSIONAL PAPER 108 PLATE XLIII 

1 

SPECIES OF ORTHOPH RAGMINA. 
PLATE XLIII. 

Orthophragmina mariannensis var. papillata Cushman, n. var. (p. 117). 

FIGURE 1. Surface view of a fairly complete speCimen, X 6. U.S. G. S. station 7126. 

Orthophragmina georgiana Cushman, n. sp. (p. 117). 

FIGURE 2. Surface view of a nearly complete specimen of the papillate form, X 8. , U.S. G. S. station S387, 

FIGURE 3. Surface view of type specimen, X 8. U. S. G. S. station 7348. · 

Orthophragmina vaughani Cushman, n. sp. (p.l~8). 

FIGURE 4. Surface view of type specimen, X 8. U.S. G. S. station 3387. 

FIGURE 5. Surface view of a less fully developed specimen from the same station, ·X 8. 

123 

•, 
PLATE. XLIV. 

Orthophragmina mariannensis and var. papillata Cushman, n. sp~ an n. var. - (pp. 116, 117.) 

Rock specimen from Marianna, Fla., showing two spechnens of the typical form of the spee!es and one of the variety 

at die lower left, X 4. U.S. G. S. station 6768. . . 

124 

0 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XLIV 

SPECIES OF ORTHOPHRAGMINA. 
DEPARTMENT OF THE INTERIOR 

FRANKLIN K. LANE, Secretary 

UNITED STATES GEOLOGICAL SURVEY 

GEORGE OTIS SMITH, Director 

Professional Paper 108-H 

THE PLIOCENE HISTORY ()F NORTHERN - ' 

AND CENTRAL MIS~3ISSIPPI 

BY 

EUGENE WESLEY SHAW 

Published February 15, 1918 

Shorter contributions to general geolo~'y, 1917 

(Pages 125-163) 

WASHINGTON 

GOVERNMENT PRINTJN,G OFFICE 

1918. 

CONTENTS. 

Page. 

Introduction. . . . . . . . . . . . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 

or~elation of deposits and surface featur~s of lower and upper parts of Miss ssippi basin .. . ....... ____ ....... . 125 

Sedrmentary record ............................... _ . .................... . ........... -__ .... _ .. _ .. _ . _ . . . . . 126 

General character of pre-Pliocene formations ....... _ ... ~ .... ;_ ..... ;._ ..................... ___ ... _.~... 126 

Identification of pre-Pliocene formations ....... _ ..... . __ .... __ .... __ ............... __ .. __ · ___ .... _..... 127 

"Lafayette formation" ........... ____ . . . ... __ .................... __ ~ _ .............. . .... ___ . . . .. . .. . 128 

Gener~l nature ......................... _ ...... . ............ . .......... __ . . . . . . . . . . . . . . . . . . . . . . . . . 128 

Interpretations .......... _ ... _ . _ ..... . ... . _ ........... . . . .. _ ..... . . ~ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 _ 

Basis of various interpretations ..... _ ... ___ .. .. .. . . .. .. .. . . .. . . . . . .. .. . .. .. .. .. .. . . .. .. . . . .. . . . . .. 131 

Terrace deposits correlated with the Oitrone1le formation.... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132 

Location. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132 

Number arid names ............. ~ ... · ..................... . . .. ....... ~ . ·. . . . . . . . . . . . . . . . . . . . . . . . . . . 134 

Constitution .......... . .................................................................. ". . . . . . . 134 

Hollow pebbles ~f iron oxide ....................... . .... _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 

Stratification .................................. · ....... . .......... ~ ... -........ .. ................. 138 

Stratigraphic relations...................................... .. .................................... 139 

Fossils ................................................... . . . ...... . . _-__ ......................... 139 

Age and correlation ....................... . ................ . ...................... : . . . . . . . . . . . . . . 139 

Upl~~~:~:~nma:~~:~~i~~l~~~~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ i~~ Temporary definitions ........ . ......... . ............................................ -.............. 141 

Possibility that some record of Pliocene time may be left in the colluvium or residuum .... _ . . . . . . . . . . 142 

Colluvium .... _ •...... _._.~ ................. -....................... : ......... ·.......... . .......... .142 

General nature ................. .. ......... .................................................. 142 

Pebbles and boulders ......................................................... ............. 142 

Distribution and lithology ........................................ --....... _ .. -... . ..... _.... 142 

Source ........ ~ ....................................... .. __ .. . ....................... . ..... - 143 

History ................................. . .... -. _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 

Past cycles .......................... . _ ... ·..... . .. .. ......................... . . . . . . . . . 143 

Present cycle .. ........... . .... . ................. _ ........................ ~ . . . . . . . . . 144 

Residuum .................. . ............... . ...... . ............................ ~ ............. ·... 146 

General nature."--- ... . ..... -........... _-. .. ............ . .. _ .............. ~................... ·146 

Iron content .................... . . -. .. . . . . . ..... . .......... _................ . ................. 146 

:Bearing on Pliocene history of region ...... _ ............... , .................. _ . .. . . . . . .. . . . .. . · 148 

Physiographic record .......... . . .. ................... . ... . ..................................... . ... ,...... 148 

Nature of data ...... . ..... . . . . . .... . .. . .......... . ..... ·_ ................ . ............ _ . . . . . . . . . . . . . . . _148 

General surface configuration of the region ...................... : . ......... _ .......... .. ~ . • . . .. . . . . . . . .. 149 

Uplands ....................... . ......... . .. . . ·. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 

Monadnocks .............................................. . ................................. ·. . . . . 149 

Evenness and concol'dance in height of lower crests....................................... . ........ 150 

Relation of physiographic features to those of the Appalachian province............................ 151 

General character of surface along border...................................................... 151 

Highland· Rim peneplain... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • . . . . . . . . 152 

Coosa peneplain .. . ........... . ...... . ................ . . . ............. .. . ·..................... 153 

Warping of peneplains ................ . . . ....... : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 

Terraces ..........•..... --. . .......... . .. . ................ ~ .. _, ...................................... 154 -_ 

General features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 -

Brookhaven terrace ....... . ... . .......... . ......... . .... . .... ~ ............... -. . . . . . . . . . . . . . . . . . . . 155 

Sardis terrace... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 -

Canton terrace ............. · ............ . ..... . .. . ................. . ............................ ~ 156 

Loxley terrace .............................. . ............ . ................................ , ..... - 156 

Warping of terraces ....................................... ~ ........ . ........ _ ............ ~ . . . . . . . . 156 

III 
IV CONTENTS. 

Physiographic record-Continued. Page. 

Drainage modifications .... · ........... ·....•....... ........................ ..... ..•................... 156 

Mississippi River................................................................................. 156 

Pearl River ...................................... ~ .............. ·.· ......... ~.................. .... 157 

Big Black River ...................................... _.: .... .. ................................ 158 

Tom big bee River .............................................. ·. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 

Structural record ....................... · ........ ................... .. ........ ...... '. . . . . . . . . . . . . . . . . . . . . . . 160 

Conclusions ...................................................................... · .................... ·_ . . . 160 

Interpretation of the "Lafayette formation'' .................. ..... .... ~ ........... ~................... 160 

Diastrophism .....••••••................. : ................ ... ................................ ~ . . . . . . . 161 

Position of surface at beginning of epoch ............................................ :. . . . . . . . . . . . . 161 

Deformation .••.•••••••••...................................... ~ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 

Erosion ...................•.••....... ............................. : .................. ; . . . . . . . . . . . . . . 161 

Weathering and local transportation..... . ..... . ... . ..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 

Through transportation and corrasion.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 

Drainage modifications .•........................ , ........................................... ~ . . . 162 

Sedimentation.:. . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 

Sedimentation in valleys· ................... ' ............... : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 

Coastal sedimentation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 

Climate and life of the epoch .................. . ............ :. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 

ILLUSTRATIONS. 

PLATE XLV. Generalized east-west and north-south sections of Mississippi. ............................... . 

XLVI. Stratification and general appearance of massive, cross-bedded, and laminated material 

formerly included in the "Lafayette formation," now interpreted as belonging with various 

formations underlying Mississippi. ................................................... ~ ... . 

XLVII. Stratification an'd general appearance of material formerly regarded ·as "Lafayette formation','' 

at and near type locality, now regarded as belonging to the Wilcox group ............. . 

XLVIII. Stratification and general appearance of Pliocene and eu.rly Pleistocene terrace deposits, most 

of which have been classified as " Lafayette formation" ................................. . 

XLIX. Stratigraphic relations of Pliocene terrace deposits .......................................... . 

L. Hollow pebbles of iron oxide (Klappersteine), possibly produced by replacement of limestone 

pebbles ........... · ...................................................................... . 

LI. Uneven bedding and gravelly portions of Pliocene terrace deposits .............••............ 

LII. Typical exposures of colluvium ............................................................ . 

LIII. Exposu,res suggestive oi origin of colluvium ................................•. _ .............. . 

LIV. Recently formed deposits of known origin and history, somewhat resembling the older colluvium but still differing rather markedly. ~ ........................ ~ .......... ~ .. ' ......... · 

LV. Remarkable pocket-like features, suggesting filled burrows or potholes, and ' pebbles and 

· boulders of quartz and quartzite from colluvium ........... · ..................•......... ~ .. . 

LVI. Residuum or material in place but modified somewhat by .;eathering, though little if any part 

has been removed ..................................................................... . 

LVII. Views illustrating reddening and probable concentration of iron compounds near the surface .. 

LVIII. Profiles along Illinois Central Railroad from Grand Junction, Tenn., through Jackson to Martinsville, Miss., and from a point near Memphis, Tenn., to Grenada, Miss .......••....••.... 

LIX. Views illustrating occurrence and mode of .development and the excellent exposures afforded 

by old field gullies ......................................... . ·· .................. · ........ . 

LX. Vie~s illustrating peneplains and monadnockS ................................ ~ ............. . 

FIGURE 21. Diagram showing general nature and areal arrangement of materials underlying the surficial deposits 

of . Mississippi .............................................................. ~ ............. . 

22. Diagram showing the slope of the Cretaceous peneplain, according to Hayes and Campbell, and the 

slope of the Paleozoic floor beneath the Cretaceous deposits of Mississippi, which has been· considered as b~ing equivalent to this peneplain ..................... , ......................... . 

23. Diagrammatic profile to show relations of upland surface features of Mississippi to the peneplains 

in a portion of Tennessee to the northeast ........................ ~ .......................... . 

24. Diagrammatic cross section of flio ene deposits and profile of Pliocene terraces in the south end of 

Mississippi ............................... · ........ ~. · .... ' ................................. 

25. Sketch map showing shapes of drainage basins in Mississippi ................•.................• 

Page. 

126 

132 

132 

132 

133 

138 

139 

142 

142 

142 

143 

146 

147 

148 

148 

149 

127 

150 

151 

155 

:L59 
• 

THE PLIOCENE HISTORY OF NORTHERN AND CENTRAL MISSISSIPPI.1 . 

By EUGENE WESLEY SHAW. 

INTRODUCTION. 

The record of Pliocene time in northern and 

central Mississippi is generally assumed to 

he scant or lacking. The published geologic 

maps of this region show no Pliocene formations, and the only deposit in the region that 

has been assigned to the Pliocen~ is the unmapped . so-called Lafayette formation. This 

formation, however, in recent years has lost 

some of its good standing, for several students 

. have become convinced that the material constituting the "Lafayette" in Mississippi has 

been altogether misinterpreted, most of it being simply more or less weathered material belonging to various underlying formations. 

Heretofore no stratigraphic record of early and 

middle Pliocene time and no physiographic 

record of any part of this epoch have been recognized in this region, and hence if recent views 

concerning the "Lafayette," commonly regarded as late Pliocene, are correct, knowledge 

of Pliocene events in this part of the State is 

very scant indeed .. However, recent work on 

the later Tertiary and Quaternary geology of 

the Mississippi embayment has brought to 

light an unexpected amount of data bearing on 

the Pliocene history of Mississippi, and the object of the present paper is to present some of 

these data in preliminary form and to point out 

their apparent significance. They pertain not 

only to the deposits of the region but also to 

the surface features. Space is not available for 

more than an outline of the basis of the conclu::. 

sions set forth, and the life of the epoch is 

barely mentioned. 

. The field work upon which this report is 

based was done in the years 1912 to 1916, inclusive, and is a part of a general study of the 

1 In its basis of field work and in its conclusions this paper is closely 

related to a recent paper by G. C. Matson, entitled "The Pliocene Citronelle formation of the Gulf Coastal Plain" (U. S. Geol. Survey Prof. 

Paper 98, pp. 187-192, 1916. The writers of the two papers visited 

critical points in the field together and compared their data and conclusions. 

Mississippi embayment planned and arranged 

for by T. Wayland Vaughan, chief of the section of Coastal Plain inv-estigations of the 

United .States Geological Surv-ey. For sev-eral 

years before 1912 the writer had been studying 

the surficial geology of the upper part of the 

Mississippi basin, and thus,.although the report 

deals primarily with only a portion of Mississippi, it is based upon a general study of both 

the upper and lower parts of the Mississippi 

basin. It has been the writer's good fortune 

to see also deposits and surface features more 

or less closely related to those under discussion 

in other parts of the Atlantic and Gulf Coastal 

Plain, including eastern Mexico. In the field 

work in Mississippi he had the advantage of 

frequent consultation with Dr. E. N. Lowe, 

State geologist. · 

CORRELATION OF DEPOSITS AND SURFACE 

FEATURES OF LOWER AND UPPER PARTS OF 

MISSISSIPPI BASIN. 

One of the principal objects of the study of 

the embayment area was the correlation of the 

late Tertiary and Quaternary deposits and 

physiographic features of the Mississippi embayment and Gulf coast with those of the 

upper par.t of the Mississippi basin. The need 

for such correlation has long been felt. For 

example, concerning the field work of R. D. 

Salisbury in 1889 T. C. Chamberlin 2 says: · 

The especial object of this investigation was to determine the relationships between the valley deposits of the 

lower Mississippi and the glacial. deposits of the upper 

, Mississippi. By examining these deposits at the supposed 

po,int of their junctions with the border of northern drift 

it is hoped to demonstrably establish their time ratios 

and their genesis. 

The elev-enth and twelfth annual reports of 

the Surv-ey contain similar statements as to 

Prof. Salisbury's work. No area offered greater 

promise for valuable results, for here extensive 

2 U. S. Geol. Survey Tenth Ann. Rept., pt. 1, p. 129, 1890. 

125 
126 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

Coastal Plain deposits of late Tertiary and loess of the upper part: of the Mississippi basin _ 

Quaternary. age were believed to be contiguous has been traced almost continuously to that 

to if indeed not actually interstrati:fied with of the lower part, a:rid apparently there are at _ 

glacial deposits, and a -great trunk stream, least two other deposits :of :loess in both areas, 

along which terraces and .other alluvial de- one older and one younger, but both Pleistoposits might be -expected flows from . one cene. (2) Two low stream ~erraces, one probpart of the area to the other. In New Jer- ably Illinoian and the other Wisconsin, may 

sey, how~ver, deposits of the two classes be traced from the north into the Mississippi 

were found to be more c~osely connected, . embayment, where both dip . down to the 

though no large stream flows from the deposits present flood plain of the Mississippi. No 

of one class to those of the other. As a matter· record of early Pleistocene ~ime (Kansas ~r 

of fact, north of Cairo, ill., there is. a gap of Nebraskan) has yet · been found adjacent to. 

about .40 Inil.es between glacial . and Coastal or n~ar. the upper .end of the Mississippi embay-· 

Plain deposits, and in this gap the Mississippi ment. . (3) Certain rather . extensive gravel 

flows through a rather narrow gorge in which deposits along the lower Mississippi are believed -

there are practically no terrace deposits, so that to be terrace deposits of 'Pliocene age and are 

it is almost impossible to determine the rela- correlated with most of the scattered patches 

tion of any Quaternary formation of the upper of gravel in the upper part of the Mississippi 

part of the Mississippi basin to any of 'the lower basin. 

part~ . The loess deposits of the two areas, 

however, can be correlated with a considerable 

degree of certainty. 

Along the lower Wabash and Ohio not only 

the loess but also two or three low terrace deposits form a practically continuous connection 

between the ·coastal Plairi. and glacial forma.:. 

tions. On both the southeast and southwest 

borders of Illinois there are scattered patches 

of gravel that have been called Lafayette and 

are commonly regarded as late Tertiary. If, 

as the writer believes, they ~re of late Tertiary 

age, they should be of some use in correlating 

the formations' of the two areas. In southwestern Indiana, however, small areas of such 

gravel have been referred provisionally to the 

Eocene, 1 because of their position on a plain 

thought to be Eocene. . 

Although the correlation of formations and 

surface features of the upper and lower parts · 

of the Mississippi basin is thus. difficult and 

somewhat unsatisfactory, nevertheless" certain 

significant facts have been ascertained and 

certain inferences are more or less probable. 

Some conclusions by the author and others 

regarding pre-Pliocene and also Quaternary 

geology and physiography are included in this 

,paper, f<?r upon them · depends in part the 

identification of '· the Pliocene deposits and 

. surface features of Mississippi. The conclusions having to do ·with Quaternary geology 

!l!ay be __ ~u:rnmarize~ as follows: (1) The main 

t Fuller, M. L., 'and Clapp, F. G., U.S. Geol. Survey Geol. Atlas, 

· Patoka folio (No. 105), 1904. 

SEDIMENTARY RECORD • . 

The sedimentary record of Pliocene time in 

northern and central Mississippi is believed by 

the writer ~o consist principally of a part of 

the materials that have been included in the 

"Lafayette forlliation." This formation has 

heretofore been regarded as the only record of 

Pliocene time in this region, but some revision 

in the interpretation of. material referred to 

it is suggested in . the following · pages. In 

order to give a clear idea of the basis on which 

the previous inferences concerning this formation rest, it is necess~ry to describe briefly . the 

the nature of the underlying formations. 

GENERAL CHARACTER OF PRE-PLIOCENE FORMATIONS. 

The general distribution of the materials· underlying central and northern Mississippi is indicated in fig~e 21. From this map it is to be 

seen that these portions of the State .are under- . 

lain by formations ranging in ag~· from , 

Devonian to Oligocene, and that a large part 

of the area is · underlain by Eocene strata. 

No Pliocene strata are shown, the "Lafayette" 

D;lantle not being_ mapped. Most of the formations shown .consist, like the "Lafayette," 

largely of irregularly bedded silty sands, but 

a _ few . consist of limestone or clay. ·The 

individual formationshave been identi~ed and 

traced principally by means of ·their fossil 

content, lithologic character, and stratigraphic 

relations, but their fossil content is commonly meager, their lithologic character IS 

• 
U. 9. GEOL.OQICAL SURVEY 

N. 

A 

1,ooo N. 

HIGH LA -----------------

-1.000 

B 

N 0 

s 

A 

B 

H A v E N p L 

Centers of middle Pliocene upl ifts ? 

B' 

I I - 5•;;, e ~.oo uu(} 

0 10 I!> 7.0 

N 

<U 

c: Ill Vo 

uu o., 

.. ~ t 

· ... -~-:--=- . -- -:------- -

Center of latest 

~5 .)0 MI L(; 

•.• --- ..1 ----

SARDIS PLAIN ? 

c A 

PAOFE8810NAL. PAf'ER 10 PLAT£ XLV 

Feet 

1,000 

500 

0 

-soo 

s. 

-1,000 

8 

s. 1,000 

500 

0 

-500 

GENERALIZED EAST-WEST ~NO NORTH-SOUTH SECTIONS OF MISSISSIPPI, EACH REPRESENTING DIAGRAMMATICALLY THE GENERAL FORM OF THE SU RFACE AND NATURE OF THE UNDERLYING ROCKS IN A BEL.T 80 OR 40 MIL.ES WIDE. 

A. EAST-WEST SECTION THROUGH OXFORD. 

Near the east end the I ine of the section bends to the northeast. The dip of the paleozoic rocks is not k nown with certainty, but appare ntl y its directio n is southwest, though presumabl y not at t he same rate as that of the coastal plai n deposits. 

B AND B'. NORTH-SOUTH SECTION REPRESENTING A BELT THROUGH THE CENTRAL PART OF THE STATE INCLUDING OXFORD AND JACKSON. 

S hows the effect of pliocene(?) uplifts in t he south . cen tral pa rt of the state whi ch carr ied pli ocene gravels to a ompa rative ly 1reat alt itL1de. 
PLIOCENE HISTORY OF NORTHERN AND CENTRAL MISSISSIPPI. 127 

extremely varied, and their stratigraphic relations are somewhat difficult to determine. 

All three lines of evidence taken together are 

so commonly inconclusive that opinions differ 

as to the identity of some of the most accessible 

strata-those lying near the surface, abundantly exposed, and known as Lafayette. 

Some have inferred that most of the beds 

lying close to the surface belong in this surficial 

formation, which is described as differing 

markedly in many respects from the underlying formations; others, particularly more -recent workers, have thought that the concept 

of a blanket formation is incorrect and that 

most of the sands and other materials so 

classified belong in fact with the several 

underlying formatjons. Indeed, as shown in· 

Plate XLV, most of the "Lafayette" of Mississippi is found where ·the underlying beds 

are very sandy. 

IDENTIFICATION OF PRE-PLIOCENE FORMATIONS. 

The confusion concerning the "Lafayette" 

appears, to be due partly to the lack of diagnostic features in that_ formation itself and 

partly to the irregular distribution of such 

features in underlying formations. Concerning the older rocks, the testimony of fossils 

is in many places incontrovertible. Remains 

of land pi_ants are fairly common in some 

formations and sea shells in others, but nevertheless the mass of material whose age can be 

directly determined from fossils is a small 

fraction of that involved in this discussion. 

In many exposures fossils are not to be found, 

and in many others only certain beds can be 

classified with certainty by means of fossils. 

The lithologic character of only a few of 

the formations is sufficiently distinctive to be 

areas or by comparing stratigraphic relations. 

It is therefore difficult to identify much of the 

material that liesfar from beds of known age. 

Thus Tertiary and Cretaceous strata that 

aggregate thousands of feet in thickness and 

crop out over an area· of thousands of square 

miles.include few layers sufficiently persistent 

and identifiable to be traced far with certainty 

as to their exact stratigraphic positions. Yet 

these strata were long ago divided into forma25E3::::z=3:::==:E25=:==3:so'=====:i75E======SJoo M i I es 

usable in identification and mapping. The FIGURE 21.-Diagram showing general nature and areal arrangement of 

Selma chalk is easily recognized by both its materials underlying the surficial deposits of Mississippi. 

lithologic character and its fossil content, but 

most of the formations in this region and also 

in much surrounding territory in the Coastal 

Plain are made up largely of irregularly stratified sand and silt which include very few beds 

that are identifiable by their lithologic character. 

Many of the individual pre-Pliocene strata 

are not persistent and hence can not be 

correlated by continuous tracing over wide 

100833°--18----2 

tions, concerning whose general positions and 

areas of outcrop there can be no doubt, notwithstanding the fact that there is a lack of 

agreement as to whether the most accessible 

strata in the region-those immediately underlying the surface and abundantly exposed in 

cuts and washes-belong with the underlying 

strata or constitute, as has been thought for 

many years, a distinct surficial formation. 

In the opinion of the writer and others much 
128 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, ·1911. 

if not most of the material in central and 

northern Mississippi which has been called 

Lafayette or Orange sand belongs in fact with 

the underlying formations and differs from 

them only in being on the whole more reddened 

and otherwise weathered. The very fact, 

however, that ·such an idea, though tenable, 

has been so slow in arising is expressive of the 

difficulty in identifying and tracing the beds. 

"LAFAYETTE FORMATION." 1 

GENERAL NATURE. 

The ''Lafayette formation" as heretofore 

described 2 is a late Pliocene or early Pleistocene mantle deposit which crops out throughout most of the Coastal Plain of eastern North 

America and some adjoining territory, an 

area of more than 200,000 square miles. It 

consists largely of more or less deeply ironstained gravel, sand, clay, and loam, the upper 

part generally massive and the lower stratified. 

In thickness it ranges from 1 foot to 200 feet or 

more. Fossils are generally rare, and those 

that have been found are regarded as out 

of place and range. in age from Devonian to 

Pleistocene, inclusive. As described, ·the formation shows little detailed or consistent relation to altitude, -topography, physiography, 

or geologic features. However, though it 

. rests upon rocks of all ages, from pre-Cambrian to late Tertiary, it is scantily developed 

in tb.e high country of Paleozoic' and older 

rocks bordering the Coastal Plain. Its surface and base are . roughly parallel to the 

present surface, and it underlies uplands, hill-

~ides, and terraces alike. Other Coastal Plain 

formations have roughly concentric areas of 

outcrop, the youngest being nearest the sea, _ 

but this one mantles all the others. 

INTERPRETATIONS. 

The interpretations of the "Lafayette formation," though showing more or less variety, 

fall into four principal classes; the first assumes that it was deposited by flood water 

. from Pleistocene glaciers; the second, that it 

was laid do~ during a marine submergence 

1 A more complete discussion of the status of the "Lafayette formation" is in preparation. · 

2 See particularly the description by Hilgard (Geology and agriculture 

of Mississippi, 1860) and McGee (U . S. Geol. Survey Twelfth Ann. Rept., 

pt. 1, pp. 347-521, 1891). ' 

of the Coastal Plain; the third, that it is the 

product of a less catastrophic process of stream 

deposition induced by broad uplifts of the 

Appalachians; and the fourth, that much if 

not most of it is a more or less weathered portion of the older and underlying formations 

of the region, a part of it being made up of 

material of other kinds. 

Although :Bartram,3 the Rogerses/ Booth,5 

Conrad, 6 :Mather/ Lyell, 8 and Tuomey 9 had 

done some work on similar deposits along the 

Atlantic coast, and Wailes/0 Safford, 11 and Harper 12 in Tennessee and Mississippi, Tuomey 13 

seems to have been the first to attempt an extended interpretation of the "Lafayette" of 

the Gulf coast. He called it the "Southern 

Drift" and correlated it with the glacial.deposits of northern United States. Wailes had 

called it" "Diluvium or Northern Drift" without attempting an explanation, and Safford 

and Harper had called it "Orange sand." 

It should -be remarked that there has been a 

lack of complete harmony as to what should be 

included in the formation. Modifications have 

been made at different tim.es in the 80 years of 

work upon it, so that although "Southern 

drift," "Orange sand," and "Lafayette fonnation" have in a general way a similar significance, they differ somewhat in meaning from 

time to time and from author to author . 

Safford, 11 who introduced the term "Orange 

sand," applied it not only to what later becan1e 

McGee's Lafayette and Columbia, but also to 

deposits of Wilcox age (Eocene), and he classis Bartram; William, Travels through North and South Carolina, 

Georgia, east and west Florida, pp. 28-30,1791. 

t Rogers, W. B., Report of the geological reconnaissance of the State. 

of Virginia, p ; 13, Virginia Board Pub. Works, Phila,delphia, 1836. 

Rogers, H. D., Report on the geological survey of New Jersey, 2d ed., 

p. 17, 1836. 

• Booth, J. C., Memoirs of the geological survey of the State of Delaware, pp. 94, 97, 1841. · 

6 Conrad, T . A., Observations on a portion of the Atlantic Tertiary 

region; Nat. Inst. Proc., vol. 1, p. 177, 1842. 

1 Mather, W. W ., Geology of New York, pt. 1, pp. 246, 261-268, 274-

275, 1843. \ 

s Lyell, Charles, jr., On the newer deposits of the Southern States of 

North America: London Geol. Soc. Quart. Jour., vol. 2, pp·. 405-406, 1846; 

A second visit to the United States, vol. 1, pp. 344-346, vol. 2, pp. 242-

266, 1849. 

9 Tuomey, M., Geology of South Carolina, pp. 186, 188, 212, 1848 . 

10 Wailes, B. L. C., Report on the agriculture and geology of Mississippi, pp. 245-253, 1854. · ) 

u Safford, J. M., A geological reconnaissance of Tennessee: Tennessee 

Geol. Survey First Bienn. Rept., pp. 148, 162, 1856. ' 

12 Harper, L., Preliminary report on the geology and agriculture of 

Mississippi, p. 162, 1857. · 

1a Tuomey, M ., Second biennial report on the geology of Alabama, p. 

146, 1858 (transmitted for publication in 1855). 
PLIOCENE HISTOR.Y . OF NOR.THER.N AND CENTRAL MISSISSIPPI. 129 

fied both as Cretaceous. Crider,! on the other 

hand, excluded much that· had been included 

by McGee, saying: 

He [McGee] likewise included in the term Lafayette 200 

feet or more of the Wilcox which belongs to the Eocene. 

* * · * The term as used in this [Crider's J report is 

restricted to the thin veneering of iron-stained pebbles and 

sand which overlaps unconformably all the other formations of the State, from the older Paleozoic rocks along 

Ten~essee River to and including the Grand Gulf group of 

the late Miocene. * * * The thickness of the formation varies from a knife-edge to 50 feet. 

Yet McGee 2 states that ''It · is sepai·ated 

from all of the underlying formations by a noteworthy unconformity." 

It seems remarkable that there should be 

such certainty about the existence of a thing 

and such difference of opinion as ,to its whereabouts. The disagreements as to the location 

of the great unconformity at the base of the 

forn1ation suggest the query whether it may not 

after all be at the top-in other words, whether 

there is any Lafayette. 

The writer and others of the section of the 

Coastal Plain investigations of the United 

States Geological Survey have traced a part of 

even Crider's restricted Lafavette into older 

formations and suspect that · very large part 

must be so reclassified. For example, the ex-

' tensive gravel deposits that are well exposed in 

the pits east of Iuka, regarded by Crider as 

Lafayette, have been found by L. W. Stephenson and the writer independently to pass beneath Cretaceous formations at Iuka. 

Hilgard,3 the chief student of the "Lafayette" in Mississippi, agreed with Tuomey in his 

interpretations of the "Southern drift," saying 

"His [Tuomey's] suggestions regarding the 

nature and origin of the water whieh deposited 

the Orange sand [or 'Southern drift'] forrnation appear to be confirn1ed by · all the additional observations subsequently made by 

myself." He says further: 

However different may be the geological detail of the 

Orange sand formation from that of the Northern d.rift 

deposits, the evident analogy of their lithological composition and general history would lead us to suppose the two 

formations to be genetically related. In both cases immense volumes of water destitute, or nearly so, of organic 

life rushed southward, bearing with them the fragments 

and detritus of the older formations. * * * 

lCrider, A. F., Geology and mineral resources of Mississippi: U.s. Geol. Survey Bull. 283, p. 45, 1906. 

2 McGee, W J, The Lafayette formation: U. S. Geol. Survey Twelfth 

Ann. Rept., pt. 1, p. 497, 1891. 

a Hilgard, E. W ., op. cit., pp. 27-28. 

Whether or not the Orange sand deposits contain any 

material necessarily derived from a high northern latitude 

still remains to be determined, for thus fat the materials for 

comparison are imperfect on both sides. By far the greater 

mass of the pebbles occurring · in Mississippi appear to 

be referable to sources lying south of the Ohio River on 

either side of the Mississippi, while the rocks most common 

in the drift of Illinois-granite, mica schist, and metamorphi_c sandstone are either very rare or (like granite) entirely 

wanting. 

Thirty-two years later Hilgard published an- " 

other paper 4

- on the "Lafaye_tte" in whieh he 

says that the formation was laid down by running and violently agitated waters at a time of 

high elevation, partieularly of the northern 

United States, and says that much erosion 

preceded and followed its; deposition. 

The hypotheses concerning the "Lafayette" 

may be summariz~d as follows: in the order in 

which they have been advanced and peeome 

more or less popular: (1) It was laid down by 

glacial floods; (2) it is a sea deposit made during 

rapid submergence; (3) it is a stream deposit; 

and (4) it is not a formation at all but a hodgepodge of parts of various formations. Parts 

of it have also from time to time been ex-

-cluded because of their identification with 

other formations. But there have been many 

departures from this general trend. For example, Crider 5 as late as 1906 says that the 

quartz pebbles are "doubtles·s the fragments 

of the great northern drift carried southward 

by great volumes of cold fresh ~a ter at the. 

elose of the glacial epoch," thus not only subseribing to the glacial hypothesis but dating 

the formation at the end of that epoeh, whereas 

most workers, have eonsidered it much more 

ancient. The end of Pleistocene time was 

probably not more than a tenth and perhaps 

not more than a twentieth or thirtieth as long 

ago as the beginning. 

The second interpretation, that of deposition by sea water, was best set forth by McGee. 

By its excellence of logic and presentation of 

evidence his paper brought the name Lafayette into general use and crystallized ideas 

eoncerning its extent and interpretation. McGee's views are suggested by the following 

quotation: 6 

The record of Lafayette deposition is one of oceanic 

invasion, not of catastrophic swiftness, yet of such rapidity 

4 Hilgard, E. W ., The age and origin of the Lafayette formation: Am. 

Jour. Sci., 3d ser., vol. 43, pp. 389-402,1892. · 

5 Crider, A. F., op. cit., p. 45. 

6 McGee, W J, op. cit., p. 508. 
130 SHORTER CONTRIBUT'IONS TO GENERAL GEOLOGY, 1917. 

that the waves rolled over the sinking hills without carving 

shore lines; without even building broad beach~s such as 

the modern keys of the southern coast; and the inunda:-

tion was not stayed until it reached inland, drowning the 

southeastern margins of the continent in a zone 100 to 500 

miles wide. * * -*. The waves and currents spread 

* * * · [the sediment] here and there along the newmade coast, mixing it with the materials gathered from the 

new-made sea bottom. In this way only could have .been 

accumulated the widespread Lafayette mantle, composed 

chiefly of residua · of slow rock decomp<?sition and subordinately of material from local formations, together 

with great gravel beds about the waterways. * * * 

In age the Lafayette formation is many times older than 

the earliest known Pleistocene deposit, and much newer 

than any other well-defined formation of the Coastal 

. Plain. 

The third interpre~ation, that the "Lafayette" is a stream deposit, is well set forth 

by Chamberlin and-Salisbury/ who say: 

It is assumed that the [Plio~ene] upward bowing (of 

the Appalachian province] was felt first in a relatively 

narrow belt along the predetermined axis, that thle rise 

was gradual, and that the rising arch increased in breadth 

as it rose. 

The result wa.s renewed erosion and increase 

of load of the streams, and this load was too 

great for them to carry across the Coastal · 

Plain to . the sea. As the uplift progressed the 

deposit was spread farther and farther toward 

the sea. Hill and Vaughan 2 plac~ a somewhat similar interpretation on the Uvalde 

formation, which they say is of the same age 

as the "Lafayette," though they do not assume 

a broadening area of uplift and a consequent 

gradual seaward shifting of gravel. They 

say: "It does not appear to the writers that 

it is necessary to postulate a marine submergence or an absolutely horizontal deposition 

level," and they describe the deposit as occurring on the seaward side of the Balcones 

sca.rp, suggesting as conditioning agents (1) 

cloudburst storms in an ·arid or semiarid 

· region and (2) gradual uplift of the area on 

the landward side. 

It will be noted that the "Orange sand" or 

"Lafayette" is regarded as ·Cretaceous by 

Safford (1856), as Pliocene by McGee (1891) 

and by Chamberlin. and Salisbury (1906), 

and as Pleistocene by Tuomey (1855), Smith 

t Chamberlin; T. C._, and Salisbury, R. D., Geology, vol. 3, Earth 

history, pp. 305-306, 1906. 

2 Hill, R. T ., and Vaughan, T. W ., Geology of the Edwards Plateau 

and the Rio Grande Plain adjacent to Austin and San Antomo, Tex.: 

U.S. Geol. Survey Eighteenth Ann. ~ept., pt. 2, p. 246, 1898. 

and HHgard (diff~rent dates), and Crider 

(1906). ' 

The fourth interpretation of the "Lafayette" 

-that at least part of it is in reality more or 

less weathered and slumped .portions of under-

.lying formations-may be illustrated by the 

following quotations from McGee, Vaughan, 

and Berry. 

McGee 3 says: "It should be noted that a 

part of the deposits designated Orange sand 

by different geologists consists of rearranged 

residuary debris of the Tuscaloosa and perhaps 

other formations." 

Vaughan 4 argues that the "Lafayette" 

aromid Mount Lebanon and Arcadia, La., _ is 

residual and states the grounds for his belief 

as follows: (1) In it are found "fossils as casts 

in ferruginous sandstones or as ferruginous 

replacements," and these fossils are the same 

as those in the underlying formation; (2) "the 

transition from the Eocene to the superficial 

deposits can be traced"; (3) "there are in the 

specimens from the superficial deposits no 

indications of their having been waterworn." 

Berry 5 says: 

-In the exposures at Oxford the deposits are a unit with 

every graduation from unweathered materials below to 

oxidized and more or less ferruginous sands above. · Now here in this region is there a lin~ of unconformity or a 

pebble be~ to mark the supposed time interval extending 

from the early Eocene to the Pliocene. The change in 

color of the materials, when marked at all, is at varying 

levels and is due apparently to the depth to which the 

ferric oxide in the sands has been dehydrated.-

A distinct variety of this interpretation worthy o{ mention has been set forth by Harris,6 

who believes that the "Lafayette" is made up of 

parts . of various formations but that those 

parts differed originally from other parts of the 

same formations. He says:. "It has been my 

belief for several years 'that whenever the 

shingle of an old shore has -been preserved, 

there will be found 'Orange sand,' be the age 

of such littoral beds Mesozoic or Cenozoic," 

and he postu)ates a gradual seaward shifting 

of the deposits during emergence of the land. 

a McGee, W. J., Three formations of the middle Atlantic slope: Am. 

Jour. Sci., 3d ser., vol. 35, p. 330,"1888. 

4 Vaughan, T. W ., The stratigraphy of northwestern Louisiana: Am. 

Geologist, vol. 15, p. 219, April, 1895. 

• Berry, E. w ., The age of the type exposures of the Laf~yette formation: Jour. Geology, vol. 19, p. 251, April-May, 1911. 

·6 Harris, G. D., The geoiogy of the Mississippi embayment with special reference to the State of Louisiana: Louisiana Geol. Survey, pt. 6, 

p. 33, 1902. 
PLIOCENE HISTORY OF NORTHERN AND CENTRAL MISSISSIPPI. 131 

BASIS OF VARIOUS INTERPRETATIONS. 

The question naturally arises, Why should 

there be so much difference of opinion concerning the content and interpretation of the "Lafayette"~ Surely it is not because the' material has failed to receive sufficient attention ' for many able investigators have given long 

study to it in the field, and many others have 

written and theorized about it. Again, it is 

not because the formation is inaccessible for it . . ' 

hes at or near the surface and is abundantly 

exposed throughout a populous region covering 

hundreds of thousands of square miles. Why 

then should ideas concerning it differ so much 

more widely than those concerning other formations~ · 

In the first place the formation is generally 

described as being unique, both in development and in constitution, differing more or less 

markedly from any other ancient or modern 

deposit, and hence there are few opportunities 

for making enlightening comparisons. Second, 

although many investigators regard it as a 

unit having a persistent and recognizable character for example, McGee 1 says that "as a 

whole_ the formation maintains so distinctive 

and strongly individualized characteristics as to 

be readily recognized wherever seen * * * 

it is more uniform petrographically than any 

other formation of even one-fourth of its extent"; and E. A. Smith 2 says that "the Lafayette has a character * * * _ so well 

marked that the observer with any reasonable 

degree of experience will scarcely ever rerriain 

long in doubt as to its identity," yet, as McGee 

himself says, "this distinctive aspect of the 

formation is to some extent fortuitous." If it 

consisted of any single or any small group of 

diagnostic characteristics there would be less 

room for doubt. The difficulty arises out of 

the fact that it consists of a large group of features, several of which may be found together 

in another formation. . 

In correlating other deposits fossils are often 

use_d, bu~ the ''Lafayette," l!nder all interpretatiOns, Is regarded as having no index fossils. 

Fossils are often found in material that had 

been regarded as Lafayette, but it is always 

inferred either that they are out of place, having 

come from some older formation, or that the 

I McGee, W J, op. cit., p. 489. 2 Smith, E. A., Am. Assoc. Adv. Sci. Proc., vol. 55, p. 374, 1906. 

stratum containing them and all below it 

should be reclassified and put into the underlying fo~mation, for, remarkable as it mayseem, 

the fossils that are certainly in place are always 

found to be just such as occur in the formation 

which happens to lie just below. Under the 

fourth interpretation the ''Lafayette" thus 

becomes a combination of the nonfossiliferous 

autcropping portions of several formations. 

Stratigraphic relations should be of some 

use in identifying the "Lafayette," ·for it is 

described as being everywhere unconformable 

at the top and bottom, as resting upon rocks 

o~ all ages older than Quaternary, and as lying 

either at the surface or just below some oth~r 

surficial deposit. But throughout three-fourths 

if not nine-tenths of the region under discussion 

the unconformities can not be found or their 

location agreed upon. The remainil).g tenth 

or. fourth is the area of the terrace-deposit 

phase of the "Lafayette" described below. 

. Stratification seems to be one of the prinCipal features used in the -identification of the 

''Lafayette," the bedding of which is commonly, 

especially in the _area under discussion, extremely irregular, often being described as 

jumbled. But irregular bedding is also found 

in older formations, where it is of the same 

general type in so far as bedding so varied can 

be said to follow a general type of irregularity. 

Lithology is of some value in identifying the 

"Lafayette," which lacks limestone and certain other kinds of rock, though it consists of 

materials so diverse as clay, shale, sand, sand:.. 

stone, gravel, conglomerate, and iron ore. But 

the usefulness of lithology for this purpose is 

reduced by the fact that other formations in 

the region are lithologically similar to the 

''Lafayette," though perhaps none others show 

so great diversity. 

Other criteria are often useful in correlationcolor, physiographic expression, mode of weathering, etc.-and some of these are involved in 

the differentiation of the "Lafayette," but 

apparently no one of them is sufficient. Ratner 

its identification seems to rest on an aggregate 

of many features, of which any one or even 

several may be found in some other formation. 

Some single features, however-for example, 

the common extreme irregularity of bedding, 

with clay m~sses in. sand-have generally been 

believed to be somewhat more characteristic of' 
132 SHORTER CONTRIBUT'IONS TO GENERAL GEOLOGY, 1917. 

the "Lafayette" than of other formations. 

The writer and others regard these irregularities 

in bedding · as characteristic of many Coastal 

Phtin formations and believe that material near 

the surface does not differ in this respect from 

that farther down and that parts of the "Lafayette" are terrace deposits. (See PlP.XLVIXLIX.) . 

In brief, the basis upon which the first three 

interpretations of the "'Lafayette formation" 

set forth above have rested is about as follows: 

First, throughout central and northern Mississippi and also mos't other parts of the Coastal 

Plain of the eastern United States, to which all 

but a very small fraction of the material called 

Lafayette is confined, the material within 20 

to 100 feet of the surface is redder than that 

below, no matter to what formation the lower 

material belongs. Second, the material from 

1 to 15 or 20 feet below the surface is commonly 

more faintly stratified and many believe it to 

be more irregularly stratified than that below. 

Third, in some places the material within a 

few feet of the surface contains elements not 

found in the underlying formations and is set 

off from them by a rather sharply defined plane, 

being apparently susceptible of the interpretation that it consists of the remnants of terrace 

deposits. 

Under the fourth interpretation it is contended that much of the "Lafayette" differs 

from underlying formations only in being, on 

the whole, redder, except that close to the surface the stratification is fainter or disturbed and 

the color in many places changed to brown or 

buff. Thesefeatures are believed to be much 

more reasonably regarded as products of the 

, weathering and slumping of the underlying 

sandy and silty formations, both at the time of 

their deposition and later than as characteristic 

of a single formation, especially because (1) the 

constitution of the material seems to depend 

·everywhere on the constitution of the underlying formation; (2) there is.generally no sharp 

lower limit to the redness and irregular or jumbled bedding, and, on the whole, the faintness 

of the stratification decreases downward; (3) 

notwithstanding the general irregul,arity of bedding and lack of persistent strata and fossils in 

the pre-Pliocene formations strata called "Lafayette" can here and there be traced continu.:. 

ously in to strata belonging unquestionably to an 

underlying formation. Moreover, characteristic 

fossils of the underlying formation, particularly 

impressions of plant leaves, have been found 

by Lowe, 1 Berry, 1 and others in lenses of soft 

clay, s.ome of which are extensive and evenly 

laminated, and . therefore could not possibly 

have 'Qeen taken bodily from some older formation and incorporated in the "~afayette." It 

is regarded as a significant fact that the fossils 

from the "Lafayette formation" described as 

transported and redeposited are either silicified 

Pal~ozoic fossils in hard pebbles or are characteristic of the particular formation which happens to underlie the "Lafayette" at the place 

of their occurrence. 

TERRACE DEPOSITS CORRELATED WITH THE 

CITRONELLE FORMATION. 

LOCATION. 

In discussing the constitution of the·" Lafayette," Hilgard 2 says: 

There are within the State two distinct regions of occurrence in which this material [gravel] appears in force. 

One of these e~tends along the eastern edge of the alluvium 

of the Mississippi River, occupying, in northern Mississippi, parts of the counties of D~ Soto, Panola, Yalobusha, 

Carroll, Holmes, and Yazoo, gradually diminishing as the 

territory of the fossiliferous Eocene is approached and giving out almost entirely in the greater portion of Warren 

County. Then, below Vicksburg, it extends inland in a 

southeast direction and is found in numerous cuts on 

theN ew Orleans, Jackson & Great Northern Railroad down 

to the Louisiana line. 

The other region of occurrence of the pebble bed begins 

at the north on the Tennessee River, in East Tishomingo, and extends along the waters of Big Bear Creek to 

the. eastern head of the Tombigbee, reaching the latter 

str~am by way of Hurricane and Bull Mountain creeks, in 

Itawamba County. It then extends southward on the 

eastern side of the Tombigbee and is continued into Alabama, meeting the great pebble beds of the Warrior, which 

bear the city of Tuscaloosa. · 

Further study ha$ confirmed the generaliza- . 

tio:r~ that most of the gravel of the "Lafayette" 

borders· the largest streams. In Mississippi it 

is found (1) in a belt of ~oull.ties adjoining the 

Mississippi bottoms and .extending from Memphis to Vicksburg, where the belt broadens and 

swings east across the State, and (2) in the 

northeastern counties of the State and a belt 

extending southward along the Tombigbee. 

The question naturally arises: Is it not possible 

that the gravel has been misinterpreted and 

that it is in part Cretaceous and Tertiary, be1 Unpublished notes. 

2 Hilgard,E. W., Report on the geology and agriculture of Mississippi, 

pp. q-12, 1860. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XLVI 

A. B. 

c. D. 

E. F. 

G. H. 

STRATIFICATION AND GENERAL APPEARANCE OF MASSIVE, CROSS-BEDDED, AND LAMINATED MATERIAL 

FORMERLY INCLUDED IN THE "LAFAYETTE FORMATION,", NOW INTERPRETED AS BELONGING WITH 

VARIOUS FORMATIONS UNDERLYING MISSISSIPPI. 

A, Thin wavy-bedded silty sand with embedded fragments of iron-cemented sandstone 5 miles east of Batesville. B, lndisti nctly cross-bedded gravel 5 miles southeast of I u ka. C, Cross-bedded sand, shale, and pebbles of Eutaw formation half a mile south of luka. D, Indistinctly cross-bedded sand of Eutaw formation(?), with clay pebbles and streaks, 1 mile east of 

luka; altitude600 feet. E, Cross-bedded silty sand of Wilcox group at Baileys Spring, 1 mile southeast of square, Oxford. 

F, Massive purple clay of Wilcox group in bottom of lsom Ravine, Oxford. G, Thin, hard, evenly bedded white sandy 

clay 6! miles southeast of Oxford. H, Doubly cross-bedded sand of Wilcox group half a mile north of Oxford. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XLVII 

A. B. 

c. D. 

E. F. 

G. H. 

STRATIFICATION AND GENERAL APPEARANCE OF MATERIAL FORMERLY REGARDED AS "LAFAYETTE 

FORMATION" AT AND NEAR OXFORD, THE TYPE LOCALITY, NOW REGARDED AS BELONGING TO 

THE WILCOX GROUP. 

A, Uneven interfingering beds of clay and sand t~ree-fourths of a. mile north of Oxford. B1 "Jumbled" clay balls and 

lenses 4 miles west of Oxford. C, Intraformational unconform1ty between strat1f1ed redd1sh sand and wh1te clay half a mile east of Oxford. D , Somewhat indistinct, uneven interfingering beds of clay and sand three-fourths of ·a mile north of Oxford. E, Heavy beds of sand and clay 3 miles west of Oxford. F, Sharpl y defined interfingering 

beds of white clay and red sand 1 mile north of Oxford. G, Peculiar stratification of silty sand on east side of 

Fourmile Creek 2 miles east of Oxford. H, Irregular stratification of sand 1 mile south of Oxford. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XL VIII 

A. n. 

c. D. 

E. F. 

G. H. 

STRATIFICATION AND GENERAL APPEARANCE OF PLIOCENE AND EARLY PLEISTOCENE TERRACE DEPOSITS, 

MOST OF WHICH HAVE BEEN CLASSIFIED AS "LAFAYETTE FORMATION." 

The strata seem to range generally from 5 to 10 feet in thickness and to be comparatively persistent and yet lenticular, and these 

seem to be diagnostic features. A, 3t miles east of Bates ville, M1ss. B, 3 miles east of Batesville, Miss. C, 6t miles 

southeast of Oxford , Miss. D, 3~ miles east of Batesville, Miss. E, Part of type exposure of Port Hudson formation at Port 

Hickey, La., probabl y early Pleistocene but shows same general form of stratification as Pliocene terrace deposits. F, West 

end of main part of petrified forest 3 miles southwest of Flora, Miss. G, Detail from E, illustrating buttress form of 

weathering common in sandy clay deposited by Mississippi River. H, 8z miles west of Grenada, Miss. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE XLIX 

B. 

A. 

D. 

F. 

E. G. 

STRATIGRAPHIC RELATIONS OF PLIOCENE TERRACE DEPOSITS. 

A, Terrace deposit resting on strata of Wilcox group and overlain by 2 feet of loess 4! miles east of Batesville, Miss. 

B, Terrace deposit resting on strata of Wilcox group and overlain by 2 feet of loess 5 miles northeast of Sardis, 

Miss. C, Reworked terrace gravel on deformed and eroded edges of Tuscaloosa formation, Cottondale, Ala. 

D, Eastern edge of terrace deposit resting on strata of Wi I cox group and overlain by loess 2! miles north of Batesville, Miss. E, Terrace deposit overlain by loess, with well-preserved old soil between, 15 miles east of Yazoo 

City, Miss. F, Terrace deposit overlain by loess 1! miles south of Edwards, Miss.; apparent gradation from one 

to the other probably due to creep. G, Terrace daposit, perhaps somewhat shifted and reworked, resting on Tuscaloosa formation, Tuscaloosa, Ala. 
PLIOCENE HISTOHY OF . NOHTHEHN AND CENTHAL MISSISSIPPI. 133 

longing in underlying formations, and in pa:rt a -

terrace deposit or a series of terrace deposits 

along the Mississippi and Tombigbee and. perhaps other streams, thus differing markedly 

from and having little relation to the "Lafayette'' of most of the broad regions between 

these rivers~ The gravel exposed in the pits 

east of Iuka, for example, is evidently neither a 

Quaternary terrace deposit nor a mantle formation corresponding to descriptions of the 

H Lafayette," for it dips under Cretaceous strata 

and belongs in that system, as was inferred by 

L. C. Johnson 1 as long ago as 1887. Other gravels have been found to belong at other places in 

the Cretaceous and Tertiary systems. 

The attempt to answer_ this question was 

begun by making a traverse westward from 

Oxford, Miss., in company with the State 

geologist, Dr. E. N. Lowe. The gravel area 

·was entered about 9 miles east of Ba,tesville. 

West of this point not only the deposits but 

also the surf ace features differ more or less 

markedly from those to the east, although the 

general altitude is not much lower. As discussed more fully under ''Physiographic :record," the principal difference · in surface features is that to the east there are no extensive 

flat upland areas, whereas to the west the 

slightly lower interstream areas are commonly 

flat-topped, and from many points it is evident that several have almost exactly the same 

height, though different groups have different 

heights, suggesting several terraces. 

Similar examinations were then made west 

of Holly Springs and near Grenada, Durant, 

Canton, Jackson, Vicksburg, Natchez, and 

Fort Adams, Miss., and St. Francisville and 

Baton Rouge, La. The same gravels were 

followed eastward across the State to the 

great deposits at Weathersby, Montrose, and 

other places, which Matson 2 has in~luded in 

the Citronelle formation. The gravels in 

Tishomingo County, in the northeast corner 

of the State, and those along the Tombigbee 

and its branches, particularly in and near 

Greene County, Ala., were then examined. In 

some districts the evidence that the deposits 

are remnants of terraces is so strong as to be 

thoroughly convincing. Elsewhere, especially 

1 Smith, E. A., and Johnson, L. C., Tertiary and Cretaceous strata 

of the Tuscaloosa, Tombigbee, and Alabama rivers: U.S. Geol. Survey 

Bull. 43, pp. 115-116, 1887. 

2 Matson, G. C., The Pliocene Citronelle formation of the Gulf Coastal 

Plain: U. S. Geol. Survey Prof. Paper 98, pl. 38, 1916. 

where the underlying rocks are limestone or 

clay, as near the junction of the Warrior and 

Tombigbee, the gravel remnants are small, far 

apart, and discordant in height. In the 

writer's opinion the discordance is due to the 

facts that the deposits are remnants of several 

terraces which stood at different heights, and 

that the underlying materials have suffered 

more or less erosion· while they were capped 

with considerable bodies of . gravel, which 

have thus been le~ down, with more or less 

lateral shifting. Some of the gravel, how-

.ever, belongs in Cretaceous and Tertiary formations. 

Although the terrace deposits are somewhat 

difficult to recognize, because they are not 

well preserved and because only a very small 

fraction of the region of their occurrencethe western part of Mississippi-has been 

topographically mapped, sufficient data have 

been gathered to rarrant the conclusion that 

some of the material formerly included in the 

"Lafayette formation" is in reality several 

terrace deposits. These deposits differ markedly from the "Lafayette" of most of t~e 

area under discussion, in being dissimilar to 

the underlying formations, in containing elements that could not have been derived from 

the weathering of those formations, in hav'ing 

a sharp lower limit, _and in lying at concordant 

altitudes. To illustrate, nearly aU the material called Lafayette :formation in . Lafayette 

County, Miss., the type locality, falls in that 

part now interpreted as belonging in the underlying formation. It consists of reddish silty 

sand and clay, such as could readily have been 

formed by the weathering of the underlying 

Wilcox deposits, and it grades downward into 

those deposits. But in Panola County, immediately to the west, there are extensive 

deposits of gravel lying at concordant and 

somewhat lower altitudes and having sharply 

defined bases. These deposits could not have· 

been produced by the weathering of the 

underlying forma~ion and are evidently terrace 

deposits of the Mississippi Valley. Some of 

them have been so profoundly eroded that 

they are now scarcely recognizable as terraces, 

but their terrace origin is shown by the facts 

that the eroded remnants are, so far as determined, of concordant heights, that the material 

is rather sharply distinct from the other material formerly referred to the Lafayette but 
134 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

now regarded as belonging with the underlying formations, and that they occupy a belt 

along the side of the Mississippi Valley. · 

NUMBER AND NAMES. 

The reasons for believing that the terracedeposit portion of the "Lafayette'! represents 

several distinct terraces are largely found in 

differences in altitude, which are discussed 

under "Physiographic record." No reasons 

for subdivision have yet been found in the 

nature of the materials, and apparently differences in degree of weathering or dissection are 

not sufficiently marked to .be usable as criteria. 

The deposits along the Mississippi seem to lie at 

four different heights above the river bottom, 

and it is inferred that they are remnants of four 

terraces. In addition, there are also two or 

more lower terraces which are assigned to the 

Pleistocene, and these are considerably less 

gravelly. Exact and reliable determinations 

·of altitude are scarce, however, as the deposits 

have been worn down and dissected considerably, and much gravel has crept or been washed 

down over the slopes of the valleys that streams 

have sunk into them. Hence infe:r:ences concerning the number of terrace deposits are uncertain and will probably remain so for many 

years, though the number of principal developments may. be determined. In order to make 

reference'to them easier, it has seemed desirable 

to name the ·four apparently well-developed' 

terrace deposits, and Mr. Matson 1 and the 

·writer have agreed to call them Brookhaven, 

Sardis, Canton, and Loxley, in order from oldest 

to you:p.gest, each deposit being · extensively 

d~veloped and well preserved yet abundantly 

exposed at or near the place for which it is 

named. Brookhaven is in the southern part 

of Mississippi, 60 miles east of Natchez; Sardis 

is in the northern part, 50 miles south of 

Memphis; Canton is in the southern part, 25 

miles north of Jackson; and Loxley is in Bald"" 

win County, southern Alabama. 

CONSTITUTION. 

AltJ::wugh the terrace deposits are such as are 

ordinarily called gravel, the bulk of the material 

is sand through which pebbles are irregularly 

distributed. In some places the pebbles are 

contiguous, but they are rarely fitted so closely 

I Matson~ G.-C., The Pliocene Citronelle formation of the Gulf Coastal 

Plain: U.S. Geol. Survey Prof. Paper 98, p. 180, 1916. . 

together that the interstitial sand and clay_ is 

reduced to a minimum. · Generally the pebbles 

occur in irregular and poorly defined _lenses 

having a· wide range in size. In many places 

pebbles are scarce and the, material is more: or 

less clayey. The terrace deposits are comparatively poorly sorted, as illustrated by the following mechanical analyses. 

Sample 1 was taken from the Sardis terrace 

5 miles ·east of Batesville, and sample 2 from the 

Canton terrace 3 miles west of Canton. Each 

sample weighed about a pound and was· taken 

·from what seemed to be a single layer lying 

about 8 feet below the surface. The percentages of the coarser constituents were determined with wire screens.; of the finer, with a 

microscope. 

Mechanical analyses of samples of Pliocene terrace materials 

from Mississippi. 

Size of grains in millimeters. 

16. 000 -11. 312 .. : ............... 11.312 - 8. 000 .. ~ ............... 

8. 000 - 5. 656 ... .. .. . .......... 

5. 656 - 4. 000 .. ' .......... ~ .... 4. 000 - 2. 828 .................. 

2. 828 - 2. 000 ................. : 

2.000 - 1. 414 .... . ............. 

1. 414 - 1. 000 ......... . ........ 1.000 - . 707 .......... . ....... 

. 707 - . 500. · ... . . . ...... . .... 

. 500 - . 3535 ................. 

. 3535 - . 250. ________ ________ .

1 

. 250 - . 177 ......... . .... · . .. .. 

. 177 - .125 .......... . .... ·_ .. 

. 125 - . 0884 .. . ............. . 

. 0884 - . 0625 ............... -- . 0625 - . 0442 ... -.-.-. -.- ... -- . 0442 - . 0312 ..... -.- . . . -... -- . 0312 - .0221.---------------- . 0221 - . 0156 ..... . .... --. : . .. . 0156 - . 0110 ... -... . .... -.... . 0110 - . 00781 .... - . - -.. -·_ . - - - . 00781- . 00552 .......... - . _· - - -

. 00552- . 00391. . -........ - . -_ -· . 

. 00391.:... ~ 0027 6 .· ..... -... - - - - - - . 00276- . 00195 ......... - - - - - , . .00195 .............. . .. . ....... 

Approxima~e 

percentage. 

1 2 

0. 1 

.1 

.3 

. 5 

1 

1. 5 

2 

2. 5 

3 

3 

3 

3.5 

6 

8 

13 

11 

11 

7.5 

6.5 

5 

4 

2. 5 

1. 5 

1 

.5 

.3 

.2 

98. 5 

I 

0 

0 

0 

0 

. 1 

.1 

. 3 

. 5 

.5 

1 

1 

1 

2 

2 

3 

4 

6 

8 

8.5 

10 

11 -

9 

9 

8 

-6 

5 

3 

99 

Samples of various surficial materials from 

Mississippi were sent to the Bureau of Soils, 

United States Department of Agriculture, with 

the request that they be analyzed according to 

the standardized method of that bureau. The 

results are valuable for c·omparative studies of 

terrace deposits and other surficial n1aterials. 
PLIOCENE HISTORY OF NORTHERN AND CENTRAL MISS!ISeiPPI. 

Analyses of "surficial rnaterials frorn Mississippi. 

[Made by Bureau of Soils, U.S. :Cept. Agr.] 

Medium Fine Very fine sand sand sand 

(0.5 to (0.25 to (0.1 to 

o.25 o:1 0 05 

Locality. 

Fine Coarse 

gra'rel sand 

(2 t) 1 (1 to 0.5 

milli- milliSilt 

(0.05 to 

0.005 

milli- milli- milli: · meters). meter). t ) t ) milli- meter). me er . me er . meter). 

32 

38 

1 

724 

Recent alluviurn. 

Mississippi River silt from bank of canal 

3 miles northwest of Vicksburg, Miss .. Mississippi River silt from foot of bluff, 

Natchez, Miss ...... , .............. ·1 

Alluvium of Tennessee River at Riverton, Ala ....... " ................... . Composite of 20 specimens of_ surface 

soil from Delay, Miss ............... . . 

Pleistocene alluviurn. 

41 Second bottom loam at west end of 

wagon bridge, Tuscaloosa, Ala ..... _ . 36 Clay from thin lamina iq. upper part of 

Natchez formation, Natchez, Miss .... 37 Sand from thin lamina at top of Natchez 

formation, Natchez, Miss ........ ... . 54 ·Pseudoloess 4 inches below the surface, 

941 

942 

943 

944 

945 

946 

725 

727 

731 

732 

734 

26 

29 

34 

35 

39 

40 

49 

50 

51 

half a mile east of Kokomo, Miss ..... . 

True loess. 

Loess 2 feet below surface near Ed wards, 

Miss ..•..... ----- ..... ---- .. ------- Loess 4 feet below surface near Ed wards, 

Miss ........ -----.----------------- Loess 5! feet below surface near Edwards, Miss ...................... . Loess 5! feet below surface near Ed- . wards, Miss ............ _ . _ ........ . 

Loess 6 feet below surface near Ed wards, 

Miss .............................. . 

''Brown loam" 2 feet below surface near Ed wards, Miss ............. ·_ ....... . 

Loess 6 feet below surface 1 mile southwest of Flora, Miss ........... _ . _ . _ .. _ 

Loess 20 feet below surface at south edge 

of Natchez, Miss. (contains fragments 

of shells) ................. _ . _ .. _ ... . 

Loess 8 to 10 feet below surface at Yazoo 

City, Miss. (contains fragments of 

shells) ............................. . Loess 12 feet below surface at Yazoo City, 

Miss. (contains fragments of shells) .. Loess 30 feet below surface at Yazoo City, 

Miss ........ ----- ... --------------- Loess 4 feet below surface 31 miles west 

of Grenada, Miss ................... . Basal! inch of loess at Yazoo City, Miss. 

''Brown loam" near Ed wards, Miss ... .. 

Loess or ''brown loam" 4 feet below sur- face 2 miles east of Chichester, near Edwards, Miss ..................... . Fossil-bearing loess, Natchez, Miss., 

from the loess clinging to several hundred fossils (contains fragments of 

shells) ............................ . Loess 2 feet above base of formation at 

Natchez, Miss. (contains fragments of 

shells) .........................•••• Loess 3 miles east-southeast of Yazoo 

City, Miss ................ " ..... .. Loess ( ?) 10! miles east of Yazoo City, 

Miss .... -----------------··------- Loess 15 miles west-southwest of Canton, 

Miss.' .................... ..•••...• 

100833°--18-3 

0.0 

.0 

. 6 

. 6 

. 0 

• 0 

. 0 

. 0 

• 0 

.0 

• 0 

.0 

. 0 

. 0 

. 0 

.1 

. 3 

.1 

.0 

. 0 

. 0 

. 0 

.0 

. 7 

.1 

.0 

.0 

.0 

-- --1 

0.0 

.3 

1.9 

1.5 

.0 

. 0 

. 3 

• 6 

• 0 

.0 

.1 

. 0 

.0 

.1 

. 0 

.1 

.4 

.1 

. 0 

.0 

.5 

.0 

.0 

1.2 

.1 

.0 

.0 

.0 

0.0 

.2 

4. 2 

.4 

.1 

.1 

1.0 

;2. 5 

.1 

• 0 

.1 

.1 

.1 

. 2 

. 0 

.0 

.1 

. 0 

.1 

. 0 

.3 

.0 

.1 

.9 

.1 

.0 

.0 

.o 

0. 1 

. 6 

39. 1 

2.6 

2.1 

3.2 

19. 1 

48.0 

.2 

. 0 

.3 

. 2 

.2 

.3 

. 2 

. 2 

. 2 

.2 

.2 

.5 

1.2 

.2 

.5 

4.9 

.2 

.3 

.4 

.4 

0. 6 

13.6 

15.9 

8.8 

4. 5 1 

12.8 

26. 7 

9. 6 

3.7 

4.2 

4.8 

4.6 

3.2 

1.5 

4.8 

5.6 

9.6 

6.2 

8.4 

10.4 

9.4 

5.9 

5.8 

10.8 

9.2 

5.5 

8.3 

6.0 

34.9 

49.1 

24.1 

62,8 

66.6 

46.8 

39.4 

30.6 

88.1 

82.0 

83.4 

83.9 

85.0 

84.0 

81. 6 

86.9 

83.3 

88.2 

87.2 1 

75.9 

80.3 

77.2 

81.5 

76.0 

83.2 

80.7 

74.0 

82.0 

Clay 

(0.005 

135 

to 0 Total. 

millimeter). 

65.1 

35.9 

14.8 

22.3 

26.2 

37.2 

13.5 

8.1 

8. 1 

13.4 

10.5 

11.9 . 

10.7 

14.8 

12.6 

6.3 

5.8 

4.2 

3.8 

12.6 

7. 7 

16.5 

11.6 

5.5 

7.1 

13. 1 

16.4 

10.9 

100. L 

99.7 

100.6 

99.9 

99.5 

100. 1 

100.0 

99.4 

100.2 

99.6 

99.2 

100.7 

99.2 

100.9 

99.2 

99.2 

99.7 

99.0 

99. 7 

99.4 

99.4 

99.8 

99.5 

100.0 

100.0 

99.6 

99.1 

99.3 
136 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

Analyses of surficial materials from Mississippi-Continued. 

Locality. 

Quasiloess. 

11 Upper 2 feet of ''brown loam '' 8 miles 

northwest of Oxford, Miss .......... . 13 ' 'Brown loam'' 18 inches below the sur- face 1 mile southwest of Oxford, Miss. 

15 ' ' Brown loam'' 2~ feet below the surface · 2 miles southeast of Oxford, Miss ..... 17 "Brown loam" 2 feet below surface } 

mile east of Oxford, Miss ........... . 

Mixed loess, colluvium, residuum, and 

terrace deposits. 

7 ''Brown loam'' from a groove cut from 

top to base in a vertical face in the 

head of a ravine 3 miles northwest of 

Oxford, Miss ...................... . 9 "Brown loam" from a groove cut from 

top to bottom (5 feet) in a vertical cliff 

8 miles northwest of Oxford, Miss ..... 16 '' Brown loam'' 2 feet below the surface 

at south edge of Oxford, Miss. (probably not true loess) ................ . 24 Mixed loess 10 feet below the surface 2} 

miles north of Batesville, Miss ..... . 43 Loess ( ?) 2 feet below surface of divide 3 

miles west of Holly Springs, Miss .... 46 Loess ( ?) 4 feet below the surface 1 mile 

south of Sardis, Miss .............. . 48 Loess ( ?) 16 miles west of Yazoo City, 

Miss ............................... · 726 Material down to 4 feet below surface 3 

miles west of Grenada, Miss ....... . 728 Material down to 2 feet below surface 1} 

miles south of Oxford, Miss ....... . 729 Material2 to 4 feet below surface (mostly 

colluvium), same locality as 728 ..... 

W asked loess. 

33 Loess or loess wash, Vicksburg, Miss ... 

Recent colluvium. 

12 "Wash creep"! mile south of station at 

Oxford, Miss. (composite of 20 small 

4 

10 

42 

30 

52 

5i3 

handfuls ......................... . 

Old colluvium. 

Sandy-silt containing pebbles ! mile 

west of station at Iuka, Miss. (composite of 20 small handfuls) ....... . ''Brown loam'' ( ?) from top of exposure 

below schoolhouse, at Oxford, Miss. 

(May belong just below ''brown 

loam ") ........................... . Washed loam 8 feet below the surface 

10 miles southeast of Corinth, Miss ... 

Pliocene sea-terrace deposits . . 

Clay conglomerate 6! miles east of Pinola, Miss ......................... . Lafayette (?) from groove 8 feet high, 6 

inches wide, and 1 inch deep, cut in 

cliff in gully in northeastern part of 

Brandon, Miss .................... . "Buttress clay," Woodville Miss .•.•.. 

Fine Coarse IMedi~ gravel san'd san (2 to 1 (1 to 0.5 <

0·

5 to 

"11" "11" 0.25 m1 1- m1 1- millimeters). meter). meter). 

0.0 

.0 

.0 

.0 

.0 

.0 

.0 

.2 

.0 

.0 

.0 

.0 

.0 

:5 

.0 

.4 

.0 

.0 

.0 

5.0 

2.0 

. 0 

1.9 

.2 

1.4 

.4 

.1 

.7 

.4 

3.6 

.2 

.0 

.1 

.1 

.4 

7.6 

.1 

4.9 

.4 

1.1 

5.0 

9.3 

31.0 

.1 

3.7 

.1 

1.8 

.4 

.. 2 

.7 

.5 

2.2 

.1 

.1 

.1 

.1 

.4 

5.9 

.1 

5. 7 

1.6 

1.7 

14.1 

7.2 

23.0 

.3 

Fine 

sand 

(0.25 to 

0.1 

millimeter). 

6.1 

.5 

4.5 

1. 7 

1.0 

2.5 

2.1 

1.8 

. 3 

.5 

.6 

.6 

1.8 

18.4 

.4 

17.6 

39.6 

5.4 

45.8 

18.7 

21.3 

65.5 

Very 

fine 

sand 

(0.1 to 

0.05 

millimeter). 

5.9 

4.0 

4.0 

5.5 

5.1 

. 7. 5 

6.6 

10.1 . 

3.0 

8.1 

10. 7 

4.3 

3.5 

5.1 

9.3 

9.4 

11.5 

5.4 

3.2 

16.8 

1.2 

3.4 

Silt 

(0.05 to 

0.005 

milli~ 

meter). 

69.1 

72;6 

71.4 

76.2 

Clay 

(0.005 

to 0 

millimeter). 

13.1 

22.6 

16.7 

15.0 

74.4 18.2 

72.0 16.4 

t 

72.1 18.1 

71. 9' 9. 2 

71.1 25.0 

7.3. 6 16.8 

65.0 23.3 

78. 1 16.2 

73.0 20.1 

44.9 16.9 

85.4 

50. 7 

20.0 

56.1 

24.8 

19.5 

1.4 

13.8 

4.8 

11.3 

27.0 

29. 3" 

6.8 

22.9 

19.7 

16.6 

Total. 

99.8 

100.0 

99.8 

99.2 

99.0 

99.8 

99.8 

99.0 

99. 7 

99.1 

99.8 

99.4 

99.2 

99.3 

100.1 

100.0 

100.1 

99.0 

99. 7 

99.4 

99.6 

99.7 
PLIOCENE HISTORY OF NO::tTHERN AND CENTRAL MISSISSIPPI. 137 

Analyses of surficial malt!rials from Mississippi-Continued. 

Q) Medium Fine Very 

'a Fine Coarse sand sand fine Silt Clay 

grave . sand sand (0.05 to (0.005 

~ Locality. (2 to:. (1 to 0.5 (0.5 to (0.25 to (0.1 to 0.005 to 0 Total. tll milli- milli- 0.25 0.1 0.05 milli- milli- ....... milli- milli- 0 meten). meter). milli- meter). meter). 

ci meter). meter). meter). z ---

Pliocene stream-terrace deposits. · 

27 Ancient stream silt (?) 10~ miles westsouthwest of Grenada, Miss. _________ OA 2.1 1.7 7.1 12.0 64.6 11.1 99.0 

28 Laminated loess or ancient stream silt 

30 feet below the surface at Yazoo 

City, :Miss ____ .. ______ . _ . ____ ....... .a 1.1 .5 1.4 11.2 79.9 5.6 100.0 

45 Loess (like silt) 6 feet below the surface 

7 miles southeast of Vidalia, Miss._ . .. • B 3.5 4.1 11.4 5.5 63.0 11.6 99A 

47 Terrace deposit ( ?) 6 miles north of 

Sardis, Miss ..... _ . _ . _ . _ . _ . _ ....... .0 .6 3.1 22.4 13.3 30.2 30. 1 99.7 

Residuum of Miocene deposits. 

31 Clay from Grand Gulf formation ! mile 

east of Pinola, Miss __ ..... _ ......... .0 .0 .0 .9 5. 1 65.8 27.5 99.:> 

Residuum of Eocene deposits. 

8 Wilcox or Lafayette formation 10 to 20 

feet below the surface ~ mile east of 

Oxford, Miss ... · .......... _ . _ . ___ . _ . 6.0 60.0 16.0 15.7 1.1 .8 .6 100.2 

14 Wilcox or Lafayette formation from thin 

sand lamina j mile north of station at 

Oxford, Miss._. __ .... _._. ___ ... ___ . .0 .0 .1 2.8 20.6 42.7 33.5 99. 7 

18 Clay lens in Wilcox formation 1~ miles 

south of Oxford, Miss. A layer of iron ore has been concentrated on top of clay .0 .0 .0 .1 2.8 58. 7 37.7 99.3 

19 Leaf-bearing clay at Oxford, Miss ..... .0 .0 .0 .4 12.9 48.4 37.7 99.4 

20 Wilcox or Lafayette formation 4 to 16 

feet below the surface 1~ miles south 

of Oxford, Miss . ....... _____ . _ .. _ . _ . .6 4.4 4.4 68.2 4.2 9.2 8.5 99.5 

21 Purple clay from Wilcox formation at 

Oxford, Miss ......... _ ........ . .... .0 1.0 2. 5 7.6 6.0 43.6 38.3 99.0 

22 Clay from Lafayette or Wilcox formation at schoolhouse, Oxford, Miss .... .0 .0 .0 .6 1.0 49.6 47.8 99.0 

23 Sand from Wilcox formation 10 to 20 

feet below the smface 1~ miles south 

of Oxford, Miss ..... _ ......... _ .. ___ .0 .4 1.5 81.9 5.4 5.8 4.2 99.2 

25 Sand from Wilcox formation 4 miles 

east of Grenada, Miss. This apparently iron-free sand is interbedded 

with iron-bearing sand. _ ....... _____ .0 .7 8.1 90.1 . . 5 .1 .0 99.5 

947 Residuum 3 feet below surface near Oxford, Miss ............ _ . __ -. -....... .2 2.4 6.0 29.0 7.0 41.7 14.6 100.9 

948 Residuum 6 feet below surface near Oxford, Miss ............ _ .. ~ .......... .0 .9 2.2 11.3 6.2 70.2 9.5 100.3 

Residuum of Cretaceous deposits. 

2 Clay balls in sand 6 feet below surface 1 

mile east of Iuka, Miss .... _ .. __ ._._. .0 .1 2.0 12.4 6.1 39.9 39.3 99.8 

3 Sand surrounding clay balls 6 feet 

below surface 1 mile east of I uka, Miss. .0 1.0 8.3 70.3 1.2 3.9 15. 7 100.4 

5 Sand 5 miles south of Iuka. Miss .. _____ ' .1 .6 1.0 48.0 31.0 10.1 8.9 99.7 

6 Sand containing small masses of white 

clay 4~ miles east-southeast of Iuka, 

6.0 1 

Miss. (Is the clay the residuum of 

limestone pebbles?) ............. __ .. .0 .1 1.3 60.0 7.2 25.5 100.1 
138 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, ·1917. 

The pebbles of the terrace deposits are mostly 

·of subangular chert, though well-rounded 

quartz pebbles are common. On the other 

hand, among the sand grains quartz predominates, and both quartz and chert are less well 

rounded. Quartzite, sandstone, and some other 

. rocks are represented among the pebbles, but 

limestone seems to be lacking throughout the 

·extent of the ·deposits. Many pebbles of all 

rocks, even quartz, are ready to fall to pieces so 

long have they been exposed to the weather .. 

The ·chert pebbles have evidently come from 

the areas of Paleozoic · rocks bordering the 

Mississippi embayment, particularly central 

Tennessee and Kentucky and the Ozark province, for many of them contain identifiable 

Paleozoic fossils. Most of the quartz pebbles 

may have come indirectly from the Piedmont 

province, which extends northeastward from 

northeastern Alabama, but _if so they probably 

started long .ago and in the meantime have 

been incorporated in one, if not several, Paleozoic and younger formations, for though very 

resistant they are well rounded and hence have 

been subjected to much wear, and no trans-

. porting agent is known to have carried materi.al 

from the Piedmont province to central and 

northern Mississippi since middl~ Tertiary 

time. The large streams have been flowing 

southward across this line instead of westward 

along it, and if the "Lafayette" is not the 

product of marine invasion no shore-line transportation has been operative along this course 

since Miocene, if indeed since Oligocene, time. 

On the whole, the lower part of each terrace 

deposit is more gravelly tha~ the upper part. 

In many places the upper fewfeet is sandy clay, 

free from pebbles, and separated rather sharply 

from the underlying more gravelly portion. 

Generally, however, the gravel lenses become 

smaller, less numerous, arid more sandy toward 

the top. 

As is common with the Coastal Plain formations, the terrace deposits are more or less deeply 

stained with iron and are here and there cemented into sandstone and conglomerate. 

HOLLOW PEBBLES OF IRON OXIDE. 

In some places-for example, near highwater mark in the bluff of the Mississippi at. 

N atchez_:.iron compounds seem to have partly 

replaced the .lime carbonate of limestone pebbles, for although here, . as elsewhere in the terrace deposits, limestone pebbles are lacking, 

there are many .hollow and fragile ·pebbles of 

iron oxide which contain a little clay. They 

are similar to some of the pebbles known as 

Klappersteine, aetites, or eagle sto_nes. (See 

Pl. L.) · These pebbles must have been more 

durable at the time of their transportation, for 

although t4ey have outwardly the form of pebbles they could not have been hollow when they 

were formed, else the shells of individual pebbles would vary -in thickness, many would be 

worn through, and fragments would be abundant. The clay in the interior appears to be 

indistinguishable from the residue of limestone 

after the lime carbonate has· been dissolved 

with acid, though both materials show considerable variation. . . 

The nature of the chemical processes involved 

in the replacement is not obvious. The facts 

(1) that in other regions layer:s of iron ore are 

common at the tops of such limestones as are. 

overlain by marcasitic shale, (2) that in many 

places the contact between iron ore and limestone does not lie along a bedding plane, its position indicating that the ore is not an original 

bed, and (3) that fossils consistjng partly of iron 

o~e and partly of limestone are :q.ot uncommon 

show that the replacement of lime carbonate by 

. some iron compound takes place rather readily 

under certain conditions that are common in 

nature. The fact that in some places the ore at 

such contacts is in the form of carbonate suggests .that ground water saturated with iron 

carbonate may on reaching . ~orne . lime carbonate effect replacement because of a greater solu.-

bility of the lime carbonate in water containing 

a moderate amount of carbon dioxide. 

STRATIFICATION. 

Although the Wilcox and other sandy 

Coastal Plain formations seem to show· every 

possible variety of stratification, the terrace 

deposits are commonly distinguishable from 

them by differences in stratification ·alone. 

The s&ata of the terrace deposits are comparatively thick and persistent, they are commonly separated from one another . by . a gradation layer several inches thick, and few of 

them can be followed more than half a mile 

because, as a rule, they pinch out or become 

indistinct. The contrast in stratification is 

well shown in Plates XLVI-XLIX and LI, 

·and its significance is b~lieved to be that the 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE L 

HOLLOW PEBBLES OF IRON OXIDE CKLAPPERSTEINE), POSSIBLY PRODUCED BY REPLACEMENT OF 

LIMESTONE PEBBLES. 

Each pebble contains a little clay, and some have a I ittle iron carbonate, suggesting that iron carbonate was the replacing 

compound and that it has since changed to the oxide. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE Ll 

B. 

A. c. 

D. 

E. F. 

UNEVEN BEDDING AND GRAVELLY PORTIONS OF PLIOCENE TERRACE DEPOSITS. 

A, Evenly stratified red gravel 2 miles north of Batesville, Miss. B, Uneven bedding planes 9 miles west of Holly 

Springs, Miss.; red (dark) material Wilcox group. C, Gravel in pit on campus at University, Ala. D, Undulating bedding plane with old soil 3 miles east of Batesville, Miss. E, Gravel and clay at Rocky Springs, 

Miss. F, Gravel resting upon Wilcox group 7! miles southeast of Byhalia, Miss. 
PLIOCENE HISTORY OF NORTHERN AND CENTRAL MISSISSIPPI. 139 

terrace- deposits were made by a single large I it might have been taken from some older · 

s~ream, wher~as the Wilcox and other forma- formation and reburied in the terrace depostwns were laid down by many small streams. its. The writer, however, found some large 

STRATIGRAPHIC RELATIONS. 

The terrace deposits rest unconformably on 

rocks ranging in age from Cretaceous to Miocene or younger; In some places where the 

underlying formation is sandy and the terrace 

deposit not pebbly, it is difficult to recognize 

~he unconformity, but there can be no doubt of 

Its presence. Plate XLIX, A, B, D, G, shows 

the common appearance of the basal contact. 

The chief material overlying the terrace 

deposits is loess, which is thickest on the bluffs 

of the Mississippi and gradually thins to the 

east. It · also varies considerably along the 

bluffs, being 50 to 75 feet thick at Vicksburg 

and Natchez and scarcely half as thick west of 

Grenada. The contact at the base of the 

loess is _undoubtedly unconformable everywhere and is in places _marked by an ancient soil, as shown in Plate XLIX, E. However, as shown in Plate XLIX, F, in many 

places one formation seems to grade into the 

other. Most of this gradation is believed to 

be due to creep. At Natchez a thin layer of 

terrace gravel is overlain unconformably by a 

heavy deposit of river sand, which is apparently of early Pleistocene age; for it contains 

very deeply weathered pebbles from Canada. 

The formation which it represents has been 

so severely eroded that though a somewhat 

careful search has been made no other remnants 

of it have been found. -

The stratigraphic relations of the terrace 

deposits therefore indicate that they are considerably younger than any other Tertiary 

deposit of the region and considerably older 

than the loess and probably also than the 

early Pleistocene gravel at Natchez. 

FOSSILS. 

Diligent search for fossils that might aid 

in the determination of age and , in the 

_interpretation of the terrace deposits has 

been made by the writer and several others ' but almost none have been found. Silicified 

shells in pebbles are common but serve only 

to show that the material is post-Paleozoic. 

Petrified wood is not at all rare, but it has been 

considered of little · value in this study, for 

logs that could scarcely'have been reworkedthey are not only too large but are broken 

into sections which retain their natural position and orientation. Thin sections of some 

of this petrified wood have been cut and submitted to F. H. Knowlton, who says: 

One specimen is a conifer, probably Sequoia, and the 

other a 'dicotyledon, perhaps Querr:us. It is not possible 

t.o fix the age, though I think it is probably Tertiary, 

but beyond this I would not venture an opmion. -

AGE AND CORRELATION. 

The assignment of the terrace deposits to 

the Pliocene is based on the absence of igneous pebbles in them, their extremeiy weathered and dissected condition, their position 

topographically above the Natchez terracer 

which contains pebbles of glacial origin and is 

believed to be of early Pleistocene age, and 

the fact that they may be traced almost continuously into great deposits in the southern 

part of the State, some of which are unquestionably Pliocene.1 The terrace deposits are 

certainly younger than Oligocene, for they overlie formations of that age, and they are older 

than any of the loess, which is Pleistocene. 

Their appearance and relations indicate that 

they are much younger than the Oligocene formations and yet much older than the loess. 

UPLAND SURFICIAL MATERIALS. 

CLASSIFICATION AND TERMINOLOGY. 

For some purposes it is desirable to classify 

the material near the surface of the earth according to the extent and nature of its modification by weathering a~d other erosive 

processes. In the region under discussion 

the upland surficial deposits seem to fall naturally into the principal divisions named bel~w, 

from above downward. For convenience these 

will be called layers, though most of them 

have not been laid down as true strata. 

1. The surface soil, about a foot thick, containing more or less organic matter and other 

matte_r that has been modified by organic · 

agencies. 

2. A discontinuous but ubiquitous layer from 

1 foot to 15 feet or more in thickness, consistI Matson, G. C., op. cit. 
140 SHORTER CONTRIBUTIONS TO GENERAL _GEOLOGY, 1917. 

ing of material from the outcropping edges of landslides and creep and says that "colluvial 

underlying formations which has been washed soils form a large portion of rolling and hilly 

down slopes by sheet floods and small rills. uplands." On the whole, other authorities 

3. A layer from 1 foot to 4 or 5 feet thick, seem inclined to use the term in a broad sense 

consisting of surface portions of underlying more or less si-milar to Hilgard's usage, but 

formations which have crept a few or many most authors of geologic textbooks do not 

feet down slopes. Both Nos. 2 and 3 are as a use it at all. The adjective "pluvial" (from 

rule scarce or altogether lacking on the crests pluvius, rain) has been used for such deposits, 

of divides. but there is no corresponding noun, and, fur4. A layer of material in place, from 1 foot to thermore, rain ceases to be rain after it reaches 

5 feet in thickness and very deeply weathered. the surface of the earth. 

5. A much less but still deeply weathered Layer 3 is the result of a process for which the 

layer extending from No. 4 doWn. to the lowest ·word" creep'" is generally used, but there seems 

dry-season position of the ground-water sur-: ·to be no corresponding noun for the product. 

face. In other words, this division includes Layer 4, produced -by the weathering of 

all the material below No. 4 which is subject to underlying beds in place, might be called 

alternate wetting and drying and as a conse- residuum, but it is not exactly formed in place 

quence exhibits certain peculiarities, particu- by rock decay and left as a residue after the 

larly as regards its content of iron oxide. It ·leaching out of the more soluble products, for 

may be subdivided into two parts at the ordi- materials so extensively oxidized as those of 

nary position of ground water and ·is often most ·of the formations underlying . qplands in 

found at two horizons because of perched Mississippi can scarcely be said to decay 

ground water. . . further, and these materials consist generally of 

6. Below the dry-season ground-water table about equally insoluble substances-mainly 

the Coastal Plain strata are practically a unit quartz, clay substance, and iron oxide-and 

as regards weathering a~d consist largely of hence they are subject to little change in con- · · 

unconsolidated sand and clay many hundred stitution ·through the carrying away of more . 

feet thick, resting upon a floor of hard Paleo- soluble parts. Furthermore; layer 5, the 

zoic rocks. This division is scarcely surficial, layer between the subsoil ·and the groundand yet it seems to fall under the name regolith, water table, though differing in important 

which was proposed for unconsolidated sur- respects from layer 4, is almost as truly 

:ficial deposits. . residual. "Eluvium" also is not sufficiently 

The terms in use for surficial materials and definite and restricted. 

also those proposed but not yet current are The great mass of material below layer 5, 

only in part satisfactory for the materials comprising all the unc0nsolidated deposits 

listed above. . below the dry-season water table, is .somewhat 

Layer 1 is commonly called "soil," but many peculiar to areas of Cretaceous and Tertiary 

writers use this word in a broader sense to in- deposits in this and other parts of the yoastal 

dude this layer, the underlying subsoil, and Plain, for in few other places does a great thickvarying amounts of lower unconsolidated ness of largely unconsolidated material permaterial. petually saturated with water. rest upon a floor 

' For layer 2 the descriptive word "colluvial" of hard rock. For this material th~re seems to 

would be used by some geologists, but this be no distinctive name. It might be called 

term is an adjective and it has been used for "regolith," a name proposed by Merrill 3 for 

deposits of other kinds. Merrill 1 restricts it the"entire mantle of unconsolidated material" 

to "talus and cliff debris," a definition that resting upon "solid rock," but this term would 

would exclude layer 2. On the other hand, include all the other members in the list, for 

Hilgard 2 uses it in a much broader sense for though here and there ~he Coastal Plain strata 

the product of "rolling or sliding down, wash- are cemented they are on the whole comparaing of rains, sweeping of wind, etc." He does tively unconsolidated. 

not mention cliff debris, though he speaks of Other more or less generally current terms 

1 Merrill, G. P., A treatise on rocks, rock weathering, and soils, p. 319, 

1897; new ed., p. 307, 1906. 

2Hilgard, E. W., Soils, p.12, New York, 1906. 

·seem still less applicable to the surficial mate.,. 

s Merrill, G. P ., op. cit., new ed., p. 287. 
PLIOCENE HISTORY OF' NORTHERN AND CENTR.AL :i\HSSISSIPPI. 141 

rials in Mississippi and adjoining States than 

those already mentioned. ''Saprolite," proposed by Becker 1 for ''thoroughly decomposed 

earthy but untransported material," would include layers 4 and 5 and perhaps also a part of 

layers 6 and 1. As Merrill 2 remarks, it is also 

objectionable on other grounds. "Geest, " . 

proposed by Deluc 3 and indorsed by Eaton, 

Beck, McGee,4 and others, for decayed rock in 

place, as opposed to alluvium, has been used 

in a variety of senses, and in each it seems to include inore than one of the Mississippi deposits. "Local drift" 5 and "meteoric drift" 6 

would indicate layers 1 to 5 but were especially 

intended for residual material, for which the 

word "drift" seems inappropriate. 

TEMPORARY DEFINITIONS. 

Although most of the terms available seem 

objectionable on one score or another, it is undesirable to burden geologic literature with 

additional terms, at least until careful and 

somewhat extended consideration can be given 

to the invention of new ones. For the present 

report the existing terminology may perhaps 

be made to serve if temporary definitions are 

given and two terms introduced which, though 

new, are closely allied to two already in use. 

For layer 1 the word "soil" will be used in 

this report, the application of tl;le term being 

thus restricted to that surficial material which 

contains much plant and plant-modified matter.· The Latin word "humus" (soil) might be 

used in making a technical term, such as 

"humulite," especially as this layer generally 

contains much humus. 

Layers 2 and 3, which together have sometimes been called a colluvial deposit, deserve a 

substantive appellation, and for this purpose 

''colluvium," corresponding to ''alluvium," 

seems so natural that its apparent novelty is remarkable. The writer and perhaps others 

have used it orally for many years. This new 

term will be used in a broad sense as similar as 

possible to that given to the adjective form by 

Hilgard and others. It thus becomes a generic 

1 :Seeker, G. F., Reconnaissance of the gold fields of the southern 

Appalachians: U. S. Geol. Survey Sixteenth Ann. Rept., pt. 3, p. 289, 

1895. 

2 Merrill, G. P. op. cit., new ed., p. 287. 

a Deluc, J. A., Abrege geologique, p. 121, Paris, 1816. 

4 McGee, W J, The Pleistocene history of northeastern Iowa: U. S. 

Geol. Survey Eleventh Ann. Rept., pt. 1, p. 279, 1891. 

o Broadhead, G. C., Missouri Geol. Survey Rept., 1873-74, p. 64, 1874. 

6 Kinahan, G. H., Irish drift, subgroup meteoric drift: Royal Geol. 

Soc. Ireland Jour., new ser., vol. 4, pt. 3, pp.l15-121, 1877. 

or class name, and no doubt at a ·later date 

· the two species here referred to as layers 2 and 

3, and perhaps others, will be setoff and named. 

It seems necessary even now to recognize the 

two · species, and for these the Anglo-Saxon 

words "wash " 7 and "creep" will be used temporarily, though it is recognized that both 

words are in some respects objectionable. 

Layer 2 is perhaps the least well washed of all 

aqueous deposits, and "wash" has many other 

meanings. "Pluvialite" seems at present not 

quite satisfactory, even though the ancient 

Rorrians used "pluvialis" for "produced by 

rain." It would seem better to limit "pluvial" to the product of true rain, including 

accumulations of soil particles through the 

beating of rain, and to classify deposits made by 

little rills and other water running down hillsides as of streani origin. Not only in origin 

but in character such deposits are more similar 

to stream deposits than to material moved by 

rain beat. However, they should not. be 

classed with alluvium, and Hilgard's criticism 

of Shaler for so doing seems well taken. The 

Latin word "rivulus" (a rivulet) would thus 

seem to furnish a better foundation than 

"pluvius" (rain), "pluvialis" (produced by 

rain), or "nimbus" (pouring rain). "Creep" 

has been used by St!Veral authorities for the 

process by which layer 3 is formed, but no 

name seens to have been given to the result. 

"Creep" is not altogether satisfactory as a 

noun, but it may suffice until a better term is 

invented-perhaps "repite," from the Latin 

"repo," to creep. The Latin "gravitas" 

(weight) may be found useful as the basis for 

a generic term to include both •the products of 

slow creep and landslides which .gravitate down 

hill slopes. 

For layers 4 and 5 "upper residuum" and 

"lower residuum" may be used temporarily, 

though "residuum'' is misleading except as it 

indicates rough homology wi tl+ the un transported product of weathering in other regions, 

where, in the process of erosion, a mere soluble 

part of the rock is carried ·away and a less 

soluble part thus concentrated at the surface. 

A name for layer 6 can perhaps be dispensed 

with in this report. One seems to be needed 

that will mean unweathered, except for the 

7 See, for example, Hill, R. T., and Vaughan, T. W., Geology of the 

Edwards Plateau and the Rio Grande Plain adjacent to Austin and San 

Antonio, 'l'ex.: U. S. Geol. Survey Eighteenth Ann. Rept., pt. 2, p. 254, 

1898. 
142 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

weathering before arid during deposition, and 

signify that the deposits are comparatively uncemented, and ,another would be useful for the 

underlying Paleozoic rocks, which are both unweathered and cemented. It will be noticed 

that layers 1 to 5, inclusive, lie . in the belt of 

weathering, a part of the zone of katamorphism 1 

and those below in 'the belt cementation. Van 

Hise says: "The zone of katamhrphism is 

divisible into two belts-(1) an upper belt of 

weathering and (2) a lower belt of cementation. 

The belts are delimited by the level of ground 

water." · 

POSSIBILITY THAT SOME RECORD OF PLIOCENE 

' TIME MAY BE LEFT IN THE COLLUVIUM OR 

RESIDUUM. 

If throughout the broad area of uplands occupying·the central and northern parts of Mississippi east of the practically single row of 

counties in which the Mississippi bluffs and 

Pliocene terraces occur the ";Lafayette" consists in reality only of the outcropping portions 

of several underlying formations, the sedimentary record of Pliocene time would seem to be 

lacking in this area, for all parts of it have been 

.visited by geologists, and no Pliocene deposit 

other than the " .Lafayette" has ever been 

found. However, in a geologic sense the Pliocene epoch was not very long ago, and the 

questions arise: (1) May there not have. been 

made in this region in that epoch some deposit 

of which, though now mostlyworn away, some 

remnants are left on or just below the surface~ 

(2) Even if no Pliocene deposit was made, may 

not the colluvium or . the residuum contain 

material from other formations or display some 

other feature due to Pliocene events~ . 

COLLUVIUM; 

GENERAL NATURE. 

The material lying from 1 foot to 10 feet or 

so · below the surface of central and northern 

Mississippi is generally massive reddish or buff, 

more or less sandy clay, having at least ·the 

general appearance of such material as would be 

expected to develop through the weathering of 

underlying more or less sandy strata. · The upper part, which, especially in the western half 

:of the region, is less sandy, has be~il called" the 

.

1 Van Rise, C. R., A treatise on metamorphism: U. S. Geol. Survey 

Mon. 47, pp. 162-163, 1904. · 

yellow loam" 2 or "the brown loam." a- Some. 

if not all of the lower part has been regarded as 

''Lafayette" or Cblumbia. How~ver, several 

inconspicuous but nevertheless definite characteristics show that this lower part is neither 

residuum nor a sea or stream deposit . . It is not 

residuum, for it contains elements not found in 

the immediately underlying strata, and it commonly has a sharply defined base. It is not a 

stream or sea deposit, for it mantles the surface 

at . all. altitudes and slopes, it is comparatively 

unsorted, it contains fragments of soft ironcemented sandstone that show no wear, and it 

partakes from place to place of the nature of 

the underlying material . . Its features indicate 

that it has been produced by rain wash, modified perhaps from time to time by climatic 

changes, and hence it falls under the class name 

colluvium. Its general features are well shown 

in Plates LII and LIII and its possible origin 

suggested in Plate LIV. · 

The upper part, comprising much of what 

has been included in the brown or yellow loam, 

is believed to be partly eolian and related to the · 

loess and partly rriuch weathered colluvium 

and other surficial material. 

PEBBLES AND BOULDERS. · 

DISTRIBUTION AND LITHOLOGY. 

The study of the colluvium was begun at 

Oxford, where after a search of a few hours 

pebbles were found that seemed considerably 

larger than any occurring. in the underlying 

Wilcox. In a few days many such pebbles 

were found, some being so large as to be more 

appropriately called boulders, whereas in the 

Wilcox no pebbles over half an inch in diameter 

were found, and few more than a quarter of 

an inch. On a later field trip an estimate of 

the average number of exotic pebbles and 

boulders present on a unit area in northern 

Mississippi indicated between 20 and 100 to 

the acre. 

The suspicion then arose that the pebbles 

and boulders had come from some very high 

gravel deposit, practically unmodified remnants 

of which ·might be found in some part of 

Lafayette County or in the adjoining region. 

A careful search, however, was without result. 

Instead, more pebbles and boulder~ were 

2 Hilgard, E. W ., Geology and agriculture of Mississippi, p; 197,1860. 

a McGee, W J, The Lafayette formation: U. S. Geol. Survey Twelfth 

Ann. Rept., pt. 1, p. 393, 1891. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE Lll 

A. B. 

c. D. 

E. F. 

G. H. 

TYPICAL EXPOSURES OF COLLUVIUM. 

The colluvium shows little or no stratification and contains quartz pebbles and other elements commonly lacking in underlying 

formations, also angular fragments of iron-cemented sandstone. A, Colluvium about 2 feet thick, overlain by 2 feet of loess 

and underlain by Wilcox group, with an old soil at top, half a mile north of station at Oxford, Miss. B, Colluvium with fragments of iron-cemented sandstone at base, south edge of Oxford, Miss. G, Colluvium, from 5 to 15 feet thick, resting on Eutaw formation about 2 miles northwest of Leedy, Miss. D, Layer of iron-cemented sandstone fragments and concretions 

at base of colluvium 10 miles northwest of Holly Springs, Miss. E, Distribution of pebbles in subsoil 1! miles east of 

I u ka, Miss. Base of coil uvi um indicated by black I i ne. F, Distribution of pebbles in su bsoi I near top of Red Hi II, southeast 

of Jackson, Miss. G, Colluvium resting on Citronelle formation 1 mile south of Lamberts, Ala. H, Colluvium, largely 

red sand with layer of iron-cemented sandstone fragments at base, 4 miles northeast of Holly Springs, Miss. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE Llll 

A. . B. 

c. D. 

E. F. 

G. H. 

EXPOSURES SUGGESTIVE OF ORIGIN OF COLLUVIUM, SHOWING PARTICULARLY THAT IT COMMONLY FILLS 

HOLLOWS AND IS IN SOME PLACES THOUGH RARELY DOUBLE. 

Base of colluvium indicated in places by black line. A and B, Panorama of colluvium 10 miles southeast of Corinth, Miss. 

The concretionary mass beneath the collecting bag throws light on the origin of the surficial deposit, for it contains many 

Eutaw fossils, is very tragile,and has evidently been let down from the concretionary layer seen in the distance at a stratigraphic position abouf10 feet higher. The concretion is of a kind characteristic of this layer. The associated pebbles, 

however, are not COr:QI,nOn, if indeed such pebbles occur at all in the underlying Eutaw formation, and hence the con- clusion seems unav,q)dfible that the coarser parts of overlying strata have been concentrated downward in the development 

of the surficial forrn~tion and that none of the material has been transported very far. C, Small valley fi lied with coli uvi um 8 miles southeast ,.O:f"-C,orinth. D, Colluvium with very uneven base 1 mile west of luka. E, Colluvium with angular 

fragments of iron-cem~nted sandstone at base, Fourmile Creek, 2 miles east of Oxford. F, Colluvium with uneven base half a mile west\ of luka. G1 Gully filled with colluvium 71 miles southeast of Corinth. (Photograph by L. W. 

Stephenson.) H, Double(?) colluv1um half a mile west of luka. Upper 8 or 10 feet is from railway cut; below are two 

layers, each several feet th1ck, with q~artz pebbles at base. 
U. S. GEOLOGICAL:. SURVEY PROFESSIONAL PAPER 108 PLATE LIV 

A. 

c. 

B. 

E~ 

D. F. , 

RECENTLY FORMED DEPOSITS OF KNOWN ORIGIN AND HISTORY, SOMEWHAT RESEMBLING THE OLDER COLLUVIUM BUT STILL DIFFERING RATHER MARKEDLY. 

A, Exposure 7 miles northeast of Canton, showing coarse material left behind in a wash; perhaps the 

old colluvium was formed in part by the burial of a residual accumulation of this kind. B, Product of creep half a mile south of Oxford. C, Colluvium in bank of small stream 7t miles southeast of Byhalia. D, Colluvium in bank of small stream 7± miles southeast of Byhalia, somewhat 

similar to the old colluvium. E, Small filled gully St miles east of Grenada. F, Colluvium in 

bank of small stream 7-l miles southeast of Byhalia. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE LV 

B. 

A .' 

D. 

c. 

E. 

F. 

G. H. 

REMARKABLE POCKET-LIKE FE,ATURES, SUGGESTING FILLED BURROWS OR POTHOLES, AND PEBBLES 

AND BOULDERS OF QUARTZ AND QUARTZITE FROM COLLUVIUM. 

A, Filled burrows (?)extending below colluvium 3! miles southeast of Corinth, Miss. (Photograph by L. W. Stephenson.) 

B, Botryoidal quartzite from colluvium St miles south of Oxford, Miss. C, Filled burrows(?) extending below colluvium 4-! miles southeast cif Corinth, Miss. (Photograph by L. W. Stephenson.) _D, Pebbles and blocks of quartz 

and quartzite from colluvium 1 m i lenortheast of Buford M i lis, Miss. E, Fi lied burrow(?) extending below colluvium 

1! miles southeast of Washington, Ark. (Photograph by G .. D. Harri.s.) F, Botryoidal quartzite from colluvium 5! 

miles south of Oxford, Miss. G, Quartzite in place in colluvium three~fourths ofa mile north of Oxford, Miss.; the 

quartzite is so much weathered that it is about to fall to pieces. H, Near vieW of one of the filled burrows(?) just 

northwest of Strickland, Miss. (Photograph by L, W. Stephenson.) 
PLIOCENE HISTORY OF NORTHERN· AND CENTRAL MISSISSIPPI. 143 

found, every one lying at or near the surface 

with?ut regard · to altitude or physiographi~ r~latwns. The :pebbles and boulders not only 

differ f:om any In the underlying Wilcox, but 

they. differ · among themselves, falling naturally Into several groups. Lithologically they 

may be classified as iron-cemented sandstone 

or sandy iron oxide, quartz, quartzite, and 

chert. All the pebbles are of very resistant 

materials, and ~et _most of them are deeply 

weathered. · Thmr features are illustrated in 

Plate LV. 

The fragments of iron-cemented sandstone 

s~ow all degrees of rounding, rang~ng from 

pieces that are almost entirely angular to some 

t~at are nearly sp~erical, and it is generally 

~Ifficult to determine whether the rounding 

Is due to wear or. to concretionary or some other 

cementation. · 

The quartz pebbles are nearly white and are 

well ~oun~ed, but many show more or less deep 

solutiOn pits and some, particularly the larger 

ones, hav:e many cracks, probably made by 

changes In temperature extending over a 

long period of time. M:any of them have one 

or two flat faces, indicating that they have 

been broken by this process of insolation. 

~he quartz.ite pebbles and boulders display 

a wide_range In form. Some look so much like 

the quartz pebbles that a close examination is 

necessary to distinguish them. On the whole 

they are larger, more angular, and more of a 

cream or brownish color. The most striking 

features they display are the huge size of such 

blocks as those 5~ miles south of Oxford, one of 

which is over 8 feet ac:r:oss, and the botryoidal 

form of some of the same blocks and others 

elsewhere, as illustrated in Plate LV B D F ' ' ' . Another feature, which, though more obscure, 

is fully as significant with reference to the origin 

of · some of the quartzite, is the presence of 

gra~ns of certain minerals, particularly graphite, 

wh~ch are characteristic of the metamorphic 

regwn of northern Georgia and farther north. 

Except the boulders nothing has so far been 

found in the residuum that promises to throw 

light on the Pliocene history of _the region, 

t~ough here an.d there th~ clay and sand portwns seem to differ essentially from the underlying materials. · 

SOURCE. 

Th~ fact that all the pe,bbles and boulders 

are within a few feet of the surface and are· 

much larger than any found in underlying formations indicates that they came from some 

other formation, and they are sufficiently nu-

~erous and observations on the size of pebbles 

In the underlying strata are sufficiently abun- . 

dant to put this inference beyond question. 

The ~arge size and angularity of such quartzite 

blocks as those shown i~ Plate LV, B, makes the 

conclusion that they are less than a mile from 

their place of formation practically unavoidable, but. on_ the. other hand the p;resence 

of graphite In fmrly well rounded quartzite 

boulders 1 to 5 inches in diameter points 

clearly to a source in the area of metamorphic 

rocks 200 miles to the east. Obviously, then, 

the quartzite is of two v~rieties. Some was 

formed i!l the Coastal Plain by the cementation 

of sand grains with silica without the help of 

~igh temperature and pressur~. Such quartzItes have been found at numerous places in the 

Mississippi embayment, particularly in the 

Cla~bo~e group, the northernmost outcrop of 

· whiCh Is at Grenada. Being similar in certain 

peculiar features they may also be similar in 

conditions of development and perhaps also in 

age to the abundant· quartzite blocks scattered 

over some parts of the Dakota plains and the 

region to the west. On the other. hand, some of 

the quartzite must have been subjected to high 

pressure and fairly high temperature, else it 

would not contain delicate flakes of graphite. 

Such flakes could scarcely have been taken by 

water, wind, or any other agent from some other 

rock and incorporated in the sand of this rock 

at the time of its deposition without the delicate 

cleavage folia being broken up if not ground to 

powder or floated, b~cause of their lightness, 

far out among finer deposits. 

HISTORY. 

Past cycles.__:_Although something can be determined concerning the original source of the 

pebbles and boulde-rs, their history is largely 

problematic. The quartz and some of the 

quartzite pebbles and boulders evidently 

started in the region of metamorphic rocks 200 
144 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

miles and more to the east. At many places the eroded landward portions of formations 

the quartz and quartzite boulders are cer- now present in the region once contained pebtainly larger than any in the formations which bles larger than any now fou:nd in them. If 

underlie these places, and they seem larger the blockS of stone too large to be moved by 

than' those known to be in place anywhere -streams, rills, and rain wash were so numerous 

else in the region. The large quartzite blocks 

and probably the iron-cen1ented sandstone 

also were formed near by; for such sandstone 

occurs abundantly in many formations in 

the region particularly near the surface and 

some of the quartzite blocks are too large 

and too angular to have been transported_ 

far. The chert pebbles had .their source-in a 

region of Paleozoic limestone; probably most 

of them came from central Tennessee. In 

any event the pebbles and boulders are. evidently remnants of strata now worn away, for, 

they are not concretions or other forms originating in their present positions. The question then arises, Did those strata belong to a 

single formation that covered all or practically 

all the region, or did they belong to several 

formations, some or all of which are still represented by more or less continuous deposits~ 

It seems improbable, if not unbelievable, that 

they are the sole remnants of a single formation, for the removral of a formation from an 

area of 10,000 or 20,000 square miles would 

ordinarily proceed by its complete removal 

from some parts of the area before it had 

scarcely been dissected in other parts. The 

removal of '99.9 per cent or more from all 

parts of the area before all had been carried 

away from any part seems altogether beyond 

possibility, t~ough if possible for any formation it would be so for one consisting of sand 

and silt containing scattered boulders. If the 

boulders had been let down from a single formation th}3y should show some relation to altitude and surface features. · They should be 

most abundant near their source and in the 

bottoms of washes and gullies. 

The second hypothesis, that the boulders 

have come from several different formations, 

seems to accord with all known facts and principles. The original landward portion of any 

coastal-plain deposit, whether marine or subaerial, is likely to. be coarser than the seaward 

portion, and as the beds off-lap one another the 

landw~rd portion of each formation is exposed 

from the beginning of deposition, though the 

seaward portion is buried and protected from 

erosion. · Hence it is not at all unlikely that 

as to form a I thick bed, they would act as- a 

resistant stratum which in the 1course of erosion. 

would come to cap the highest hills. But . if 

they were scattered here and there in a matrix 

of sand and clay this :fint;~r material would he 

worn away from above, around, and below 

them, and they would be let down, with more 

or less lateral shifting, until by long exposure 

to the weather they would be broken to pieces 

small enough to be carried away. 

Little has been determined concerning the 

long gaps between the times when the pebb.les 

were integral parts of their parent rocks and 

the time or times when they reached their present positions, probably· before · the Pliocene 

epoch. The quartz pebbles may have passed 

through several cycles of weathering, transportation, and deposition. Probably they 

have traveled fat, and to this their rounding is 

no doubt partly due. On the other hand, their 

long travel is due partly to their ·rounded form . 

. Some of the quartzite may have had a similar 

varied history. The large, angular quartzite 

blocks, however, and the iron sandstones have 

never formed parts of any strata except those 

in which their cementation was accomplished 

and those in which they now lie. They seem to 

be similar in origin to the "graywethers" or 

"sarcen stones" of the English chalk downs, 

except that these are believed to be relics of 

formations not now . present in the region. 

Some of the chert pebbles, particularly the 

smaller ones, may have been taken from their 

parent limestones long ago, dropped in a 

Coastal Plain formation, and perhaps later 

taken up and redeposited once or many times, 

but it seems probable that most of them came 

directly from the Appalachian province comparatively late in geologic time, during one of 

the more recent epochs of uplift of that province. 

Present cycle.-The questions then arise, 

When and under what conditions were the pebbles moved from their places in the last formation of _which they formed a part to th~ir present positions, and how far did they travel~ 

These questions are more germane to the present discussion, for it is believed that their 

answers afford data on the Pliocene history. 
PLIOCENE HIST'ORY OF NORTHERN AND CENTRAL MISSISSIPPI. 145 

The data bearing on them are · also more abundant and less inscrutable. The distribution of 

the pebbles, their stratigraphic relations, and 

certain general inferences concerning rate of 

erosion seem to throw light on the Pliocene 

history of this region. 

The fact that the pebbles and boulders are 

nowhere concentrated into gravel beds or lenses 

but are widely and rather evenly scattered, 

particularly over the smoother middle and high 

portions of the surface, suggests that their lowering began, if indeed most of it did not occur, 

at a time when the region was lower and 

smoother than now, for if they had been let 

down by the erosion of their matrix while the 

country was rough they would have shown a 

tendency to move away from divides and down 

slopes, accumulating here and there in the bottoms of gullies. A similar argument indicates 

that their downward movement has not been 

great-at least not many hundred feet. 

Their apparently close genetic relationship 

and the fact that they rest upon Coastal Plain 

formations ranging from middle or early Cretaceous to Oligocene indicates that they came 

to their present positions not longer ago thari 

middle Tertiary time. , 

It seems much more likely that the pebbles 

came to approximately their present positions 

in Pliocene time than in any other epoch. If 

pebbles and boulders had been scattered over 

the surface of Mississippi in any epoch preceding the Pliocene, it seems very improbable that 

most of them would still remain near their 

original position, for in the opinion of the writer 

the assumption is well warranted that the up;. 

lands of central and northern Mississippi have 

been worn down more than 100 feet in Pliocene 

and Quaternary time. The present rate of 

erosion is probably about a foot in 10,000 years. · 

The pebbles and boulders have certainly been 

let down many feet, for they are found only in 

the colluvium. If they had been lowered much 

less than 100 feet, one might reasonably expect 

to find here and there remnants of the-beds from 

which they came, but no such remnants have 

been found. They have not been let down 

many hundred feet, however, for they are somewhat evenly distributed and are almost as common on divides as anywhere else. On sharpcrested and steep-sided ridges and knobs they 

are scarce or lacking, but on rounded divides 

they seem as common as anywhere else. No 

beds known tobe of Quaternary age have been 

so extensively eroded. Hence it is inferred that 

the beds from which the pebbles and boulders 

came were worn away, in part at least, in Pliocene time, and the somewhat even distribution 

of the pebbles and boulders suggests that the 

region lay lower in that epoch than it does now. 

Just how the colluvium was formed is not yet 

clear. The distinctly greater abtindance of 

coarse material at the base and the great 

extent of the deposit can apparently be explained best by climatic change, for ordinarily 

in the wash of soil down a slope there is little 

chance for such sorting. It would therefore 

appear that the basal coarse material was accumulated under different conditions from those 

which .existed while the upper, finer part was 

being formed. 

The general history of little hillside gullies in 

the region to-day seems to consist of (1) cutting 

of the gully, (2) deposition of gravelly and sandy 

silt in its bottom, (3) gradual obliteration of the 

gully by wash of fine material from above and 

the sides. This proce~s being qbserved, the 

resulting deposit was carefully . compared with 

the older colluvium, but it was found to differ 

markedly on the whole, though perhaps not in 

any single essential respect. The principal difference is that the basal coarse layer is much 

more irregularly developed in the present-day 

colluvium. This may be accounted for by the 

fact that owing to the activities of man in clearing forests and pasturing, etc., washing proceeds more rapidly than formerly, with results 

that differ not only in extent but in kind; but 

this seems scarcely an· adequate explanation, 

and hence the writer is inclined to accept the 

hypothesis of climatic change. 

On the other hand, objections may be raised 

'to this hypothesis. The greatest climatic 

changes since middle Tertiary time have been 

those of the glacial epoch, and it might be reasonably assumed that the colluvium was pro..:. 

duced by them, but if so it should be possible to 

find several deposits of colluvium of different 

ages and in many places one deposit superimposed upon or cutting another, whereasin only 

a few places, as in the railroad cut half a mile 

west of the depot at Iuka (see Pl. LIII, H), has 

one colluvial deposit been found above another. 

In any case many of the pebbles and boulders 
. 146 · · SHORTER CONTR.IBUT'IONS TO GENERAL GEOLOGY, 1917 • 

seem to date back to Pliocene time, though they 

may not have reached their present positions in 

that epoch. 

Except the pebbles and their arrangement 

little that promises to throw light on the 

Plioce:p_e history of the region has so far been 

found in the colluvium, though here and there 

the clay and sand portions seem to differ from 

underlying materials. ·One of its very remarkable features consists of forms that resemble 

filled burrows or potholes and extend down 

into underlying material. Harris 1 reproduces 

a photograph (see Pl. LV, E) showing one of 

these burrows;which he ascribes to a Cretaceous 

reptile, a Cretaceous age being assumed because 

the supposed burrow is in Cretaceous strata on 

a hillside and higher strata crop out near by. 

But the writer has found a great many of them, 

and all are connected with the colluvium. The 

best· examples of them have been found by 

L. W. Stephenson in new cuts along the Illinois 

Central Railroad 5 to 10 miles southeast of 

Corinth, Miss., and pictures of some of these 

are shown in Plate LV. To judge by the 

present rate o{ erosi~n these burrows would 

seem to be of late Pliocene or early Pleistocene 

age. 

RESIDUUM. 

GENERAL NATURE. 

Below the material which has been moved 

down slopes a greater or less distance by some 

agency, or at the surface in places where such 

material is lacking, ·lie strata of different ages 

that are in almost the exact position in which 

they were deposited and yet have been subjected to the somewhat effective weathering 

process of frequent wetting and drying. (See 

Pl. LVI.) They consist for the most part of 

irregularly bedded sand or clay or mixtures of 

the two. ' The upper few feet of this member, · 

here called the upper residuum, commonly has a 

different appearance from the underlying part. 

In some places it is huffish gray or dull colored, 

contrasting with the brigh~er-hued strata below, but more generally it has red, brown, or 

black colors due to iron oxide, which here and 

there constitutes more than half of the deposit. 

(See Pl. LVII.) Below is a greater thickness of 

bright-colored and more sharply defined strata, 

the lower residuum, extending down to the 

dry-season water table. 

1 Harris, G. D., Oiland gas in Louisiana: U, S. Geol. Survey-Bull. 

429, pl. 15, B, 1910 . 

IROi,q" CONTENT. 

It seems to have been generally assumed 

that the iron which is so abundant or at least 

so conspicuous near the surface in Mississippi 

was deposited in one form or another along 

with · the sediments .with which it is now mingled, except for so.me shifting by solution and 

redeposition. For example, Crider 2.says: "The 

water passing through the Lafayette takes up 

iron oxide in solution-and, being checked by the 

underlying impervious bed, ·deposits the iron 

oxide, thus cementing t~e sands into a compact mass." It is also assumed that the relative abundance of red color near the surface 

is due to some chemical change induced by 

exposure to the weather. Thus Berry, in- the 

quotation given on page 130, ascribes the redness 

of the surficial material to dehydration of ferric 

oxide.. Hilgard,3 on the other hand, says that 

the color is due to ,"hydrated peroxide of iron 

or orange-yellow ocher." So far as the writer 

can determine many of the more or less reddish 

tints displayed may be due to either hydrous 

or nonhydrous iron oxide, and not only limonite 

and hematite may be present but perhaps 

turgite or other oxides and also iron compounds 

that are not red, such as the carbonate, sulphate, and sulphide. 

If the iron has been subject to solution and 

redeposition and to change in constitution, it 

is reasonable to suspect that these processes 

would have been affected by_ any change in 

climate or altitude, by any burial · benea.th 

strea~ or sea. sediments, and perhaps by faunal 

or floral changes. If so, the question presents 

itself, May not some Pliocene events have been 

thus recorded and the record preserved ? 

Although the iron 'compounds ·seem to have 

been modified more than other portions of the 

residuum, perhaps other materials -may also 

contain scraps of Pliocene history. A search 

has not yet brought to light any considerab~e 

record of this sort. Evidently one reason IS 

that such records are more obscure than might 

be expected, and a:qother is that the greater 

part of any rec?rd that was. m.ade has been 

effaced ·by erosiOn. The pr1nc1pal effect of 

such chanO'es as those mentioned would have 

been felt ~thin 50 feet of the surface, and the 

writer believes that most of the region h~s 

2 .Crider, A. F., Geology and mineral resources of Mississippi: U. S. 

Geol. Survey Bull. 283, p. 46, 1906. 

a Hilgard, E. W., op. cit., p. 7. 
U. s •. QEOJ..OGIC~L S.URV.EY PROFESSIONAL PAPER 108 P)..AT,E LVI . 

A. 

c. 

B. 

D. 

E. F. 

RESIDUUM OR MATERIAL IN PLACE BUT MODIFIED SOMEWHAT BY WEATHERING, THOUGH 

· LITTLE IF ANY PART HAS BEEN REMOVED. 

Dr. E. A. Smith believes that much of the iron cementation shown in railway cuts has occurred since the 

cuts were made, but some is apparently much older, perhaps PI iocene. The residuum seems to contain 

material brought to it in solution and in the form of minute particles by the way of pores, from strata 

removed in the PI iocene and other epochs. A, Tuscaloosa formation 5 miles east of Tuscaloosa, Ala. 

B, Wilcox group 2 miles east of Holly Springs, Miss. C, Wilcox group at Oxford, Miss. D, Eutaw 

formation about 11 miles northwest of Leedy, Miss. E, Wilcox group 6! miles east of Sardis, Miss. 

F, Wilcox group 13 miles east of Holly Springs, Miss. 
U. $. GEOLOGiCAL SURVEY PROFESSIONAL PAPER 108 PLATE LVII 

B. 

c. D. 

E. F. 

G. H. 

VIEWS ILLUSTRATING REDDENING AND :PROBABLE CONCEN I RATION OF IRON COMPOUNDS NEAR THE 

SURFACE. 

A, One mile north of station at Oxford, Miss. B, Gravel composed of hollow pebbles of iron oxide 1 mile north of wharf at 

Natchez, Miss. (See Pl. L.) C, Red sand with much iron oxide over· impervious white clay, Grand Junction, Tenn. 

D, West side of Fourmile Creek, 2 miles east of Oxford, Miss. E, One mile south-southeast of Oxford, Miss.; upper part 

of white material is impervious clay and basal part of overlying red sand is more than half iron oxide. F, Three-fourths 

of a mile north of Oxford, Miss. G, Three-fourths of a m.ile south of Oxford, Miss. H, 4! miles south of Oxford, Miss.; 

sand is white under clay lens showing in upper part of view but reddened to each side. 
PLIOCENE HISTORY {)F NORTHERN AND CENTRAL MISSISSIPPI. 14 7 

been reduced more than that · amount since II water table, and many iron crusts ma).Je inPliocene time, and an additional, probably terpreted as marking a present or former posistill greater, amount during Pleistocene time. tion of the ground-water surface, but these 

However, other facts point to the .inference crusts are comparatively thin instead of 

that the fundamental assumptions above men- characterizing the saturated zone or its upper 

tioned need some modification. part as a whole, evidently more of the iron-

· It seems probable that the iron was not de- j rich sand is related to impervious beds than to 

posited along with the sediments where it is present or former positions of the water table, 

. now found, but that it has been moved and and the arrangement can be much better exconcentrated not only through solution and / plained by a mechanical process of downward 

redeposition but also mechanically. The basis concentration, the minute particles of iron 

of these inferences may be briefly state'd. being swept downward by rain water as it 

Much of the iron oxide is in the form of minute sinks into the ground a.nd accumulating 

discrete grains, which are corrimonly less than at the top of the ground water, where the 

a thousandth of a millimeter in diameter, and rain water. js stopped or its velocity greatly 

some are less than a ten-thousandth. Many checked. · 

of them are thus smaller than the pores of sand It should be remarked, however, that a large 

and other surficial material an4 must be car- part of the iron oxide is very irregularly disried about by percolating water. The main tributed, in an unaccountable manner, and 

movement is naturally downward, for the much of it has -evidently been affected by 

downward movement of water after a rain is[ solution and reprecipitation, for some of it fills 

more rapid and more effective in washing than pores completely as a practically impervious 

the upward and lateral movements due to[ mass and some of it coats sand grains, adhering 

capillarity and hydraulic gradient. As a rei to then1 closely. The iron oxide is thus found 

suit and also because the comparatively im- in two principal f<;>rms-as a compact mass 

pervious bed acts as a strainer the iron i~ clinging to sand grains and filling pores and as 

concentrated· at the base of a porous layer andl loose particles scattered through the pores. 

the top of an impervious layer. fany specirr1ens of. what seen1s to be deeply 

The accumulatio~ of iron oxide at the top o~ iron-stained red sand are easily cleaned by 

a clay layer, as illustrated by the quotation washing in water, and under the microscope 

from Crider on page 146, has been ascribed to the iron oxide is seen to consist of separate 

transfer in solution, but the assigned reason! particles. The iron · thus seems to be transfor precipitatio~ of the iron seems inadequatel ferred both mechanically and in solution, and 

Only two poss1ble causes suggest themselves, there is reason for believing that the dominant 

and both seem probably ineffective. First, th ~ process is a downward mechanical concentraimpervious bed is generally different in chen1J tion, followed by a slight rearrangement and 

ical constitution froll_l the ·pervious bed, and compacting by solution and redeposition. 

something in it may cause a precipitation of ·In son1e places, particularly where erosion is 

the iron, but there is little reason for assuming proceeding rapidly, the n1aterial most enriched 

that such a reaction occurs, particularly as thJ with iron lies at the surface, the iron having 

iron is concentrated only at the top of the imT come from material eroded away. In a railpervious bed. Second, it is conceivable that way cut half a mile south of the station at 

the iron oxide is slowly being precipitated frorrl Oxford about 5 feet of colluvium overlying 10 

ground water all the time, and the reason wh~ feet of sandy Wilcox strata is exposed. A 

more of it accumulates at the top of clay beds series of samples were taken at this place and 

than elsewhere is -that water is more nearl~ submitted to Chase Palmer, of the United 

perpetual at such positions than elsewhere. States Geological Survey, with the request that 

But if this is so, it would seem that iron should the percentage of total iron· in each be deteraccumulate at and below the water table and mined. The results show a concentration of 

that the sand above should be robbed of its iron at the present surface and a similar coniron content. In many places there seems to centration at the old surface which existed 

be a concentration of iron at the top of the before the colluvium was laid down. 
148 SHORTER CONTRIBUTTONS TO GENERAL GEOLOGY, 1917. 

Percent' of metallic iron in colluvium and residuum hal/ gravel may have been swept from the region a mile southwest of station, Oxford, Miss. under study. 

[Chase Palmer, analyst.] As detailed topographic maps have not been 

Colluvium: Per cent. made for most of Mississippi, full and ex1 foot below surface.······ ·· ····· ·· ····· 3· 85 act data regarding the surface features, such as 

2 feet below surface ......... . .......... ·. . . . . 3. 08 

3 feet below surface._. __ _ , _______ .__________ 2. 58 are necessary for their interpretation, are com4 feet below surface . ............... . ........ 2. 06 partitively meager. The literature concerning 

Residuurp. : Mississippi seems to · contain no .descriptions of 

6 feet below surface.·---·----- -- ---- --·-·- · 3. 18 peneplains and little reference to terraces. The 

8 feet below surface · · · · · · · · · · ·-· · · · · · · · · · · · · 2· 85 drainage lines are well shown ori many maps of 

~~ :~ ~:~~; ::!:~:~ ~ ~ : ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~: :~ the State, but they appear in greatest detail on 

14 feet below surface ... . ......... . ........ . . 89 the General Land Office map, upon which most 

.BEARING ON PLIOCENE HISTORY OF REGION. 

If the process of downward concentration of 

-iron is now operative it has presumably been 

in progress for ages, though perhaps modified 

from tin1e to time by climatic changes. If the 

surface of central and northern Mississippi has 

been lowered by erosion 100, 200, or 300 feet 

since the beginning of the Pliocene epoch, and 

the process of concentration has been active 

during this tin1e, some iron from strata worn 

away in Pliocene time is probably present in 

the region to-day. But the search for some 

record of climatic an~ other changes in the 

iron deposits has thus far been fruitless. Ironrich layers and lenses lie at many positions; 

which so far seen1 quite discordant, and much 

of the iron-cemented sand does not follow the 

bedding but cuts across it at various angles. 

PHYSIOGRAPHIC RECORD. 

NATURE OF DATA. 

In order to decipher the physiographic history of a region it is necessary first of all 'to have 

knowledge concerning areas that are approximately flat or that lie at accordant altitudes, 

for such features, whether large or small, may 

mark periods of erosion, producing extensive or 

incipient peneplains; of erosion and sedimentation, particularly in connection with stream 

terraces; or of sedimentation essentially- alone, 

such as produces the surfaces of many 8ea,Jake, 

and even stream deposits. Second, the investigator must know the arrangement of drainage 

lines. Third, he must know to some extent 

how readily the rocks underlying different 

parts of the region yield to erosion. Fourth, he 

can often use certain other facts concerning the 

nature of the sedimentary strata of the region 

and adjoining areas to which silt, -sand> and 

commercial maps are based. Information of 

other sorts is still comparatively scarce, though 

it has been considerably augmented by the 

present study. · 

The basis of the inferences set forth in this re-

. port consists of published maps and descriptions 

of the region; unpublished topographic and physiographic observations of other geologists, particularly Dr. E. N. Lowe, State geologist, and 

members of the section of Coastal Plain investigations of the United States· GeologicaJ Survey; 

results of spirit leveling, the profiles, generously furnished by many railroads (see. Pl. 

LVIII), being of especial value; and notes on the 

appearance of the surface, made by the writer 

as he traveled by rail and buggy throughout the 

region, these notes being correlated with points 

of known altitude by the help of barometricreadings between such points. 

As good topographic maps are not available,. -

it was necessary to use a barometer constantly, 

and although the readings of this instrument 

are subject to unknown and variable corrections, still, by using all possible means of 

checking, results of some value were obtained. 

The checks consisted of established bench 

marks, Weather Bureau records of air pressure. 

for the times during which the bar_ometer was 

used, the general average diurnal variation in. 

air pressure, previous barometer readings, and 

occasional sights with a hand or spirit level.. 

The appearance of the surface to .the unaided 

eye, although scarcely usable in checking even 

a barm;neter, was nevertheless recorded, especially where appearances and barometer readings were discordant. Part of the time a barograph was used to record the air pressure for 

the day at a ~ingle point, generally in a hotel, 

and .the barometer readings were modifie~ t() 

accord with those of the barograph. 
U S GEOLOGICAL SURVEY 

W 0 L F Lamar R I V E R VALLEY HEADWATERS COL DWATER R I V E R 

Grand Junction 

. · c· £N RTtN SVIL L£ M ISS. ; •••hd\lgan ity L£ FROM GRAN{) Ju'VCiJON, T IV .. TO MA 

: pRof1 · 

.• . / _ •• •••• ••• ·-. .•• ,_ .... ,, . , •• , •• , ___ ,. , ___ ,. , -. ····~· .. _r,/',_ ....... , • .,_... Col'J;;:!:r .. · .... ... . 

;·- - · ... . .. ... ............ -.. .. ----------· Hen18ndo -.' '- ---•"\· -~'" ' .. --· r ..... -----..... _, ......... ____ .......... .. 1 ...... ___ .. _ ... _ .. _ ..-.. _ --:------.... _ .... / .. _ ............. _ ... ......... .. ........... , --

500-

20 

400-

20 

10 

40Q300 

200 

tOO 

210 miles from Jackwn. Miss. 205 

Abbev ille 

' 

165 

S<;obey 

_/ .~" .. '"---.-.... -- Tillatobe 

' -... 

Coffeeville 

125 

62·mi!e 5iding 

BOTTOM LANDS, HAYS CRE~~ 

Col l~ge Hil l 

, ........ _,. ...... ,-:·-......... --....... _ ..... , ...... .... '\; .. .. sardis 

160 

H~rdy 

---...... _ ... __ ---·-----...----

Torrance 

120 

Horn L4ke Nesbitt 

200 ISS 

Oxford 

r a.l.lahatchi.e 

·.,_·.'•.·.·,!·--V>,•, __ .-,-,, _____ ,___ Rtver 

---- -~--- .... .. ! ..... : .... ·--;•'" " - -----........... " .................. .. , ..... _______ __ _ ---j "---......... - - -

T"l l,hatchie ' Bates'ville 

155 

115 

YaLobusiUL Rb•er 

Grenada VALLEY 

110 

190 185 

'-'--.... --~--¥ ___ .......... _ ---; ..... ----- Courtland Pdpe 

150 145 

5 I D E, BATUPAN lli~tt R I V E R 

105 

BLACK R IVE R 

Love 

~" __ ,._, ''-,.__ ... ~ ... ~ ... ~>~ _ ... "' 

---....... ---

Duck Hill 

100 

Du t 

' 

140 

ater 

180 

95 

Aberdeen Junction BO T T OM 

135 

L A ND S , 

PROF"ESSIONAL PAPER 108 PLATE LVIII 

Spring Creek 

TolJ.ahatchi-. -t. 00 

!Uver 

~----- --~------------- -~~-~---~-~~~~~~~~_,--,3 00 ~-- .. -\ ..... ---------- Senatobia 200 

100 

0 

175 170 

~on 

::::::::: ...-- ---: ... S ..c:-: ..=- ~~...:..:.~:.::..::::::::.::......_.~~..,c,-.,.&:.--::;·-~~-3oo 

200 

100 

0 

90 

Goodman 

B I G B L A C K R I V E: R 

13 0 

-400 -~-----~-------1 300 

200 

100 

0 

0~----------------~---------.--------~--~----~--~----~--~----~--~---.----~--~----~--~----r---~------------~----.---~----~--~----~---.----~--~----~--~----s~--~----~------------~----L o 45 

200 

100 

0 

85 55 80 75 70 65 60 

v,u~h"" BLACK , RIVER 

200r-·---------~~---------------/--------~--_/ 

Pickens I 

' B OT TOM LANDS, BIG BigBlackRiver Canton 

: C ANTON TERRACE 

300 

200 

tO 100 

0 

40 35 30 25 20 15 10 

Mil l Hazlehur11t t~ rt.in ill e 

400- Asylum switch Jack:!!on Terry B R 0 0 K H A v N L A -400 

300 

200 

100 

0 

NORTH --- 0 ~ SOUTH 5 10 15 20 25 3 0 

PROFILES ALONG ILLINOIS CENTRAL RAILROAD FROM GRAND JUNCTION, TENN., THROUGH JACKSON TO MARTINSVILLE, MISS., AND FROM A POINT NEAR MEMPHIS, TENN., TO GRENADA, MISS. Profiles show surfa,ce features before cuta and fills were made. 

Figures along bottoms of profiles show distances north and south from Jllcltson, Miss. 

Vertical I!Cale exaggerated about 20 times. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE. LIX 

A. B. 

c. D. 

E. F. 

G. H. 

VIEWS ILLUSTRATING OCCURRENCE AND 'MODE OF · DEVELOPMENT AND THE EXCELLENT EXPOSURES 

AFFORDED BY OLD FIELD GULLIES. 

Such gullies may have played an important part in the Pliocene erosion of the region, though they were no doubt much less numerous than to-day. The part played by the sod in resisting erosion is well shown. Many of the .gull ies have rounded 

instead of V -shaped heads and evidently grow neither through erosion by water flowing into their heads nor through softening of materials by underground water issuing as a seepage, but only because of the fact that the rain which falls into 

them finds erosion easier than that which falls on sodded areas. A, Recent colluvium on border of flood plain 1t miles 

south of Delay. B, 8 miles south-southeast of Yazoo City. C, 5 miles west of Grenada. D, 12 miles east of Batesville. 

E, 7 miles west of Oxford. F, 12 miles west of Oxford. G, 15 miles east of Batesville. H, At Oxford; shows filling after 

deep erosion. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE LX 

A. B. 

c. D. 

VIEWS ILLUSTRATING PENEPLAINS AND MONADNOCKS. 

A and B, Peneplain with monadnock ii1 distance 6 miles east of Holly Springs; the road on the right follows an even-crested divide, whose top was once a part of 

the peneplain. C, Thackers Mountain, a monadnock, from a point 5~ miles south of Oxford. D, Flat plain at altitude of 600 feet (barometric) on Ripley road, 

11 miles east of Holly Springs. 
PLIOCENE HISTORY OF NORTHERN AND CENTRAL MISSISSIPPI. 

GENERAL SURFACE CONFIGURATION OF THE known as Thackers Mountain stands on the 

REGION. west side of the Illinois Central Railroad 5 

The surface features of northern and central miles southwest of Oxford, and another, someMississippi are those of comparatively rough what lower, known as Summerville Mountain, 

elevated coastal plain, sculptured for the most is 9 miles west-northwest of Oxford. These 

part in only slightly consolidated sand and hills are not capped with gravel or other mateclay, the layers of which are nearly fiat but rial differing from the country rock, though as 

lenticular and commonly ill defined. The alti- a rule each one has a layer of sand firmly cetude ranges from about 800 feet above sea level men ted by iron at or near its top. · 

at the tops of some of the higher hills in the The question then arises whether any or all 

northeastern part of the State to about 100 feet of these striking isolated hills have been 

on Mississippi River at Vicksburg, in the south- formed in one and the same cycle of erosion. 

west corner of the area here discussed. The Apparently the two in Lafayette Qounty ~ere 

profile in Plate LVIII shows some of these not formed in the same cycle, for one, Thackers 

features. · Mountain, rises above a· high divide, whereas 

The areas underlain by sand are mostly 

rough, and some of them are almost rugged. 

The ·areas of clay and limestone are less extensive and smoother; some parts, as for example 

the uplands north .of West Point, being strikingly fiat and prairie-like. A part of the fiat 

country around West Point, however, is made 

up of terrace tops. The principal areas of 

clay and limestone are along the ea&t and south 

sides of the region. The divides in these areas 

are lower than in the sand areas; on the other 

hand, the valley. bottoms seem somewhat 

higher. . Old field gullies are common in most 

parts of the State, and their general form is 

illustrated in Plate LIX. 

The physiographic record of Pliocene time in 

Mississippi seems to fall into three principal 

divisions. One is found in the upland surface 

forms, another in high terraces along Mississippi. River, and a third in the arrangement of 

~ drainage lines. 

UPLANDS. 

. MONADNOCKS. 

the other, Summerville Mountain, is on the 

side of the · broad valley of To by Tuby Creek, 

and its crest is scarcely so high as the divide 

between this stream and Clear Creek, the next 

stream to the southwest. According to barometer readings, it is also considerably lower than . 

the divide between Tallahatchie River and 

Yocona River, the major drainage lines to the 

northwest and sou.theast. 

Most of the isolated hills, however, stand on 

high uplands and their tops show more or less 

concordance in height . . Those in the northeast _ 

corner of the State reach about 800 feet above 

the sea; those in the Pontotoc Ridge country, 

east of New Albany, about 700 feet; and 

Thackers Mountain about 600 feet. In Choctaw County hills that are perhaps similar in 

history have crests at about 650 feet, suggesting that if they are of the same age . the area 

including Choctaw County has been uplifted, . 

for it is no more favorably situated with reference to drainage lines than the area to the 

north. The similarity in height of these isolated hills is not very close, however, the high 

hills in any county commonly showing a disSeveral more or less distinct stages in erosion / cordance of 100 feet or more. · 

are reco~d.ed in the surfac~ features. T~e I The fact that no such large m~sses of ~ard 

most stnking and most legible part of th1s rock seem to be present anywhere 1n theregwn, 

record consists of isolated monadnock-like hills except on the tops of scattered hills, suggests 

which rise above the general upland where the that their formation was started by conditions 

underlying material is sand, for sand seems to different from those of•to-day. If other such 

be much more favorable to their preservation masses were present in the earth and were 

than limestone or clay. Several of these hills sharply defined and not close together, no 

are to be seen in the vicinity of Iuka; one is 3 doubt in the progress of a single cycle of erosion 

miles southwest of the town and another· 5 they would come to cap isolated hills, but unmiles northwest . . Blue Mountain, south of less the strata were horizontal and the hard 

Ripley, and parts of the Pontotoc Ridge also masses occurred in only one layer the hills 

belong in this class. A striking isolated hill would be discordant in height. As a matter of 
150 SHORTER CONTRIBUTIONS TO GE"NERAL GEOLOGY, 191'7. 

fact, strata belonging at the horizons of the 

iron-cemented hill caps: are well exposed at 

many places and are within reach of wells in 

extensive areas, but no, such large; hard, and 

sharply defined masses have been found except 

on hilltops. Hence it must apparently be infeiTed that the formation of the hard masses 

began on a peneplain now marked by the tops 

ofmost of these hills and that instead of .disintegrating with exposure to the weather the 

masses that now cap the hills have become 

more and more consolidated.· The processes 

~ 

~ 

In any case their rough accord:ance of•summits 

suggests a peneplain. · 10n the ·other hand, the 

hard caps ar:e .not being softened by weather 

and even seem to be due in part to the forms of 

the hills, as well as the forms of the hills to the 

hard caps. 

EVENNESS ·AND CONCORDANCE IN HEiGHT OF 

LOWER CRESTS. 

Throughout~;tlarge partoftheregion the divide , 

crests are so ~early .even that more and better 

wagon roads .are to be found on them than 

. a~ any other topographic position. 

This is well shown in Plate LX, 

which shows also in the distance 

two low mon:adnocks. ~ The even- · 

ness, _howev.er, though co.mmonly a 

striking feature, is throughout 

, most of. the region onJ.y relative. 

Generally the divides in any area 

are not only even crested but somewhat similar in height, the differences in altitude being as a rule only 

50 -to 100. feet. At many places, 

how.ever, the average altitude of 

the divid seeems to increase rather 

~b:ruptly by 50 or 100 feet, and the 

increase can scarcely be explained 

Contours showing atzitude and 

shape of' restored .Cretaceous ~Jeneplain" after Hayes and 

Campbell, 1894 

Contours showing attitude and 

shape of Paleozoic floor u.nder 

Cretaceous deposits 

· by the presence of harder rock. In 

some places the rise is so abrupt 

as to be unquestionable, but more 

. commonly there is room for doubt 

as to the existence of any signi:fi:... 

. cant boundary of a -physiographic 

feature. _ 

The scarcity of exact ·data as to 

altitude, the uncertainties of the 

barometer' and the common lack 

of definition of the surface features 

make the unraveling of the upland 

FIGURE 22.-Diagram shoWing the slope of the Cretaceous peneplain,' according to 

Hayes and Campbell, and the slope of the Paleozoic floor beneath the Cretaceous deposits of Mississippi, which has been considered as being equivalent to this peneplain. 

. erosional record very difficult. At 

hundreds of places it is evident 

that more of the upland surface lies 

at one, two; three, or even four alti-

. The contours shoWing the Cretaceous surface are. copied directly from an illustration in 

the pioneer description of peneplains of the southern Appalachians, which may be regarded as a first approximation and a representation of a hypothesis of the -authors. 

Some believe that no peneplain of the Appalachians would, if restored, have the form 

of that here represented, but there is general agreement (1) that peneplains· are represented in the Appalachian province, (2) that they slope outward from a central region at an angle no greater than that represented here, and (3) that in a belt around 

the margin of the pro; ince the slope decreases outward. 

. .tudes than at any intervening positions, · and that the difference is not due 

altogether to differences in hardness of rock 

nor to a combination of such differences and 

some other cause. But satisactory proof 

that any particular feature records a change . 

-in the rate or nature of erosion is difficult 

to obtain, and the correlation of features that 

·probably record stages of erosion is f~lly as 

of underground mechanical concentration of 

· ·iron oxide outlined on page 147 seem in accord 

with this inference. It seems possible if :not 

probable that the hard masses began to develop 

in little hollows on a smoothish surfac.e and then 

after uplift and during dissection the hard 

masses caused hills to develop where there had 

been hollows . . Had there been no peneplain 

there ~ght have been no such isolated hills. . difficult. 
PLIOCENE HISTORY OF NORTHERN AND CENTRAL MISSISSIPPI. 151 

However, after several months of study the 

writer has become convinced that several 

stages of erosion are recorded in the uplands 

and that these stages can be proved when detailed topographic maps are made. The data 

collected suggest that surfaces of concordant 

height stand at four different main positions. 

One position is represented by the tops of 

most of the monadnock-like hills. A second 

is represented by the comparatively evencrested high divides of the Pontotoc Ridge 

and some other less conspicuous features, 

particularly in a belt extending north-northeastward from the headwaters of Pearl River 

to Tishomingo County. A third, which is at 

present by far the most extensively represented, 

is. that of most of the divides of the region. 

A four.th is represented by the tops of innumerable shoulders or benches, 

which are broadest near Missis- NW. 

According to Hayes, 1 the region lying northeast. of the northeast corner of :Mississippi, 

including n1uch of central Tennessee and 

northeastern Alabama, belongs in the Highland Rim portion of the Interior Lowlands 

division of the southern Appalachian province. 

(See figs. 22 and 23·.) Later studies have not 

led to any essential revision of this classification. Hayes and Campbell 2 describe two peneplains in · this region. . The older and higher 

or "Cretaceous peneplain" slopes westward 

and southwestward from 2,000 feet above 

sea level in Warren County, Tenn., 60 miles· 

southeast of Nashville, to 1,000 feet above sea 

level within 100 n1iles, or at the rate of about 

10 feet to the n1ile. The second or Tertiarv 

peneplain is represented on Plate' YI .of -th~ 

report cited, reproduced in. part in figure 22, 

SE. 

sippi River and on the more yield- z,ooo ___ c;:_u_'"'2~~~~nd ttretaceous"J . Hi hi and Rim---------'--- e_e_n~E~~~ ---_-:. ::_ ':!.!1?'2_1~~d_R!._m_trJ~~sY~L e_e~e_p!_?i_9.. 

ing formationS. 1•

000 Prese.nt uplands.'of . . 

Sh uld d b h northeastern MISSISSippi 

0 ers On SpUrs an enC eS Floor under 

on hillsides which are accordant l _____________ c_re_ta_ce_o_us_de_p_os_it_s ____ ____::~__., . ~1,000 

in altitude but not sufficiently so 0 10 20 3<J 40 50 60 70 SO MILES 

to be terrace re1nnants and which 

bear no terrace deposits are common at still lower positions, but 

they are even more difficult of 

correlation and interpretation. 

Any single one might be due to 

a resistant bed or to some unknown cause. However, after 

traversing n1any valleys the 

FIGURE 23.-:':iagrammatic profile to show relations of upland surface features of Mississippi to the peneplains in a portion of Tennessee to the northeast, described in the text. 

This profile indicates that the peneplains ofthe Appalachian province are much younger 

than the floor beneath the Cretaceous sediments, and apparently the older of the two 

plains represented is younger than the floor under the Tertiary. This representation of 

the Appalachian peneplains seems subject to amendment of two principal sorts. ·First, 

the restored Cumberland peneplain may be warped up over the Nashville uplift, which 

falls in the left center of the figure; and, if so, the apparent discordance between it 

and the floor under the Cretaceous would be reduced. Second, there is strong indication that more than two peneplains are represented in this region, and each has a ge\].-

eral slope less than those represented, and, if so, the discordance would be increased. 

writer has become convinced that below the 

four upland flats referred to above, two or 

more changes in rate and nature of erosion are 

recorded in features that are not stream or seacut terraces. 

RELATION OF PHYSIOGRAPHIC F:mATURES TO 

THOSE OF THE APPALACHIAN PROVINCE. 

GENERAL CHARACTER OF SURFACE ALONG BORDER. 

In the northeast corner of :Mississippi and 

adjoining parts of Tennessee and Alabama 

opportunity is afforded for tracing the peneplains of the Coastal Plain northeastward into 

the Appalachian . province, where three peneplains have been mapped and described and 

have become widely known. Fortunately 

several quadrangles in this critical border area 

have been mapped topographically. 

as having a westward and southwestward slope 

in the same region from 800 to 600 feet in 

60 n1iles, or 3 1 feet to the mile. Hayes 3 a 

little later deseribed three peneplains- under 

the names Curnberlarid, llighland Rim, and 

Coosa, of which the first two apparently correspond ·to the Cretaceous and Tertiary, 

though he does not say so explicitly. The 

conclusions concerning these peneplains have 

received wide acceptance, and it would be 

out of place to discuss their status in a report 

on Mississippi. 

In the vicinity of Iuka, ·in the northeast 

corner of Mississippi, the divide tops average 

perhaps 650 feet above the sea and are thus 

1 Hayes, C . . W., Physiography of the Chattanooga district: U. S. 

Geol. Survey Nineteenth Ann. Rept., pt. 2, pl. 2, 1899. 

2 Hayes, C. W ., and Campbell, M:. R., Geomorphology ofthe southern 

Appalachians: Nat. Geog. Mag., vol. 6, pis. 5, 6, May, 1894. 

a Hayes, C. vV ., op. cit. 
152 SHORTER CONTRIBUT'IONS T'O GENERAL GEOLOGY, 1917. ' 

not far from: alignment with the slope of the 

Tertiary peneplain above referred to . . As a 

matter of fact, however, between 10 and 25. 

miles to ·the northeast the divides of to-day rise 

somewhat abruptly to 1,050 feet, and farther 

northeast the rise is again very slight. Thus 

the divides in south-central Tennessee fail to 

accord with the described slope of the Tertiary 

.or Highland Rim penephiin. To the west they 

hold their altitude or decline very gently to 

600 feet at the border of the somewhat lower 

area of :Mississippi River terraces 25 miles east 

· of Memphis. To the south · they decline 350 

feet within 80 miles, the altitude of those near 

West Point being · only about 300 feet. The 

decline is not regular but is relatively steep to 

the belt underlain by the nonresistant Selma 

chalk. . For example, the divide on which Guntown, 35 miles southwest of Iuka, is built has 

an altitude of about 350 feet. This same belt 

of weak rocks is, however, over 500 feet high 

west of Iuka, suggesting two stages of erosion·. 

South-southwest of Iuka, along the main divide 

between :Mississippi and Tombigbee rivers, and 

southward to the latitude of Natchez, or fully 

250 miles, the surface ranges from 450 to 600 

feet in altitude, showing from place to place a 

response to varying rock hardness and perhaps 

reoording substages in erosion and slight warping. In other words, the uplands of :Mississippi 

seem to show remnants of several plains, all of 

which are nearly horizontal and lie below the 

uplands of the adjoining Interior Lowlands subdivision of the Appalachian province and most 

of which, at least, have . not sufficient northeastward rise to meet the "Tertiary peneplain" 

of Tennessee, unless they have undergone a 

somewhat sharp upwarp, so as to rise 400 feet 

in 25 miles. 

HIGHLAND RIM . PENEPLA!N. 

assumption that the-uplands of Mississippi are 

not of the same age as those of the adjoining 

portion of the Appalachian province seems warranted, and this assumption is verified by the 

fact that ' the divides near Waynesboro show 

some degree of accordance with the tops of the 

monadnocks near Iuka, . suggesting that these 

two groups of features may be . equivalent in 

age and may owe their difference in size and · 

form to the difference in · underlying rna terials. 

East and south of Waynesboro, Tenn., .there 

are some rather large and flat upland areas 

that are no doubt remnants of the plain which 

Hayes called the Highland Rim peneplain, and 

apparently considered identical with the Ter- . 

tiary peneplain that he and Campbell had 

described three years before. One remnant 

is a flattish . divide area of about 40 square· 

miles, from 1 to 5 miles wide and about 22 · 

miles long, all of which ·is between 1,000 and 

1,080 feet above sea level. The crest of the 

,north end of this divide averages about 1,065 

feet above sea level and that of the south end 

~bout 1,005 feet; in other words, the divide 

slopes southwestward at the rate of about 3 · 

feet to the mile for 20 miles. 

In Mississippi, 45 miles southwest of · th~s 

area, is a monadnock whose t~p is almost 800 

feet above the sea. If the divide south of 

Waynesboro, with its slope of 3 feet to 'the mile, 

were extended to this hill it would lie 870 feet 

above the ·sea. As, if other considerations 

balance, the smaller the remnant of a peneplain 

thf\ lower is its altitude, it may be that the two 

crests are to be correlated, and this possibility 

is strengthened by one or two remnants of 

intermediate height-for example, one 3 miles 

southeast of Riverton, Ala., whose top is 850 

feet above the sea. It is also only natural 

that the peneplain should be found to slope 

continuously in a southwesterly direction 

Not only would the upwarp first referred to toward the sea and the master drainageline. 

be called for if the general uplands of :Mississippi ·In view of .the presence of a large stream 

are to ·be correlated with the Tertiary pene- (the Tennessee) in this region, it is remarkable 

plain, as described, or with the Highland Rim, that the distance between the remnants 

as it exists to-day, but also a downwarp a little described is not greater. They are so close 

farther to the northeast, for the slope of the together and so similar in altitude that it 

"Tertiary peneplain" is only one-third as great must be inferred either that they are all remas this rise, and the crests of the present divides . nants of the same surface or that the larger 

in the vicinity of Waynesboro, Tenri., 40 miles . and relatively higher ones near Waynesboro 

northeast of Iuka, :Miss., are still more nearly belong to a somewhat older surface. 

horizontal and 400 feet higher than most of the If a broader area is considered it is found 

divides of northeast~rn :Mississippi. Hence t4e that the flat near Waynesboro extends inter-
PLIOCENE HISTORY OF NORTHERN AND CENTRAL MISSISSIPPI. 153 

ruptedly northeastward 40 miles, or nearly 

to Columbia, holding the same altitude of a 

little over 1,000 feet; indeed, it may be carried 

to Duck River Ridge, 10 or 12 miles north of 

Columbia, whose crest is also between 1,000 

and 1,050 feet above the sea. East of this 

ridge the surface rises gradually for at least 15 

miles, to a point where it reaches 1,150 feet, 

and it seems to have a general eastward rise 

beyond that point. However, in the Hollow 

Springs quadrangle, 40 miles east of Columbia, 

where itis well developed and preserved, it has 

a southeastward slope from 1,200 or 1,300 

feet to about 1,100 feet within 15 miles. To 

the north the old flat is interrupted by the· 

Nashville Basin, the bottom of which Hayes 1 

correlated with a peneplain in Georgia that he 

called the Coosa. 

From these facts it is evident that the Highland Rim is _so high and so nearly horizontal 

that if projected south-southwestward it would 

inklrsect nothing in northeastern Mississippi 

but would lie slightly above the tops of the 

monadnocks in that region. _ If extended still 

farther it would likewise lie just above the tops 

of the highest hills in Union and other counties, 

and at Thackers Mountain (600 feet), 70 miles 

southwest of the 800-foot hill near Iuka, it 

would lie at 660 ·feet. Other intermediate 

hills, however, suggest that the slope of 3 feet 

to the mile is slightly reduced in Mississippi, 

so that at Thackers ~1ountain the position of 

the' old plain is perhaps 700 feet above the sea, 

this hill, like others of the monadnocks, having 

been worn down 100 feet or so more than the 

larger remnants in Tennessee. 

Still farther south the old plain seems to be 

traceable in the tops of the highest hills as far 

as the latitude of Jackson, a short distance 

south of which it is ·apparently covered by 

strata of Pliocene age, at an altitude of about 

4 70 feet. However, as the Pliocene overlaps 

somewhat it is possible that this old surface 

lies below the Miocene. The tracing is a little 

uncertain because of the lack of topographic 

maps, the poor preservation of the features 

representing the old plain, and the comparatively slight difference in· height between this 

plain and younger and lower upland plains; but 

two features relieve a large part of the uncertainty. One is the comparatively strong 

-contrast in form between the monadnock-like 

1 Hayes, C. W ., op. cit., pl. 2. 

remnants of ·the old surface and the much 

broader remnants of younger plains, and the 

other is the apparently uniform response to 

erosion by the numerous ferruginous sand 

member~ of several formations . . If no error 

has been made in tracing,· the average slope 

of the old surface in Mississippi is 2 feet to 

the mile for 200 miles. Owing to warping, 

however, the slope is not regular but apparently ranges from 3 feet to the mile to horizontality, or even a slight reversed slope here and 

there. 

COOSA PENEPLAIN. 

If the old surface represented by the tops of 

monadnocks in Mississippi is the Highland Rim 

peneplain, one would expect to find remnants 

of the younger Coosa peneplain in some of the 

lower hilltops. Correlation is somewhat un-· 

certain, because the distance from the Mississippi region to known remnants of this surface is greater than to the type region of the 

Highland Rim peneplain. It seems possible 

that the Coosa plain is compound and that its 

members are equivalent to the two or three 

upland plains of Mississippi that lie lower than 

the tops of the monadnocks. 

According to Hayes z peneplains may be correlated by continuous tracing, by noting 

similarities in degree of dissection, by observing 

coincidence of projected plains, and by determining recent drainage _ changes. To this list 

may be added observations of relation to other 

peneplains. Apparently the Coosa peneplain 

can not be traced continuously into Mississippi. 

Its degree of dissection would presumably be 

different in the "region under consideration from 

that in the type locality, because the underlying materials are very different and also 

because of a different arrangement of principal 

drain.age lines. The regions are too far apart 

to use coincidence of projected plains as a 

criterion, and no recent drainage changes seem 

to help in correlation. 

In Mississippi the next to the oldest · peneplain of which remnants are preserved lies 

a'Qout 100 feet below the tops of the widely 

spaced monadnocks, and if they have been 

wor:ri down 100 feet more than larger remnants 

its position is about 200 feet lower than that of 

the Highland Rim. On the other hand, it 

lies from 100 to several hundred feet above 

the present vall-ey bottoms, which have ap2 Hayes, q. W ., op. cit., p. 25. 
154 SHORTER CONTRIB.UTIONS 'l'O GENERAL GEOLOGY, 1917. 

proximately adjusted gradients, and it is 

maturely dissected. It thus resembles the 

Coosa peneplain in being next below the Highland Rim peneplain, in lying considerably 

above present graded valley floors, in being 

much dissected, _ antl in being the principal if 

not the only peneplain between ·the Highland 

Rim and the present valley floors. It differs 

from the Coosa plain in being somewhat more 

dissected and in being apparently one of about 

three that are younger than the Highland Rim. 

The greater dissection may be explained by 

more yielding materials. The Coosa plain is 

decidedly undulating if not rough, and it seems 

possible if not probable that it will be found to 

be compound. If so, its divisions may correspond with plains later than the Highland Rim 

lying -lower than the tops of monadnocks in 

northern Mississippi. -

Thus it · seems possible to determine the 

probable age of certain peneplains in Mississippi 

from evidence found within the State, and this 

forms a basis for revising and clarifying ideas 

concerning the age of Appalachian peneplains. 

It is recognized, however, that the data are not 

conclusive. 

WARPING OF PENEPLAINS. 

The peneplains , of northern and central 

Mississippi lie nearly horizontal, and yet all of 

them have suffered SOUle warping; originally 

each had no dou"Qt a slight general inclinati,on 

in some direction between . west and south. 

Their present slopes are in the same quadrant, 

but the directions of slope of some have ap-

- parently been shifted a little, and the amount 

of slope :of some has been increased and of 

some diminished. In general, the younger the 

plain the gentler is its present inclination, · and 

a considerable part of the deformation seems 

to have taken place in Pliocene time. 

The Paleozoic floor slopes about 30 feet to 

the mile; the plain at the base of the Tertiary 

about 20 feet to the mile; the slope of one at 

the top of the Eocene and others buried in the 

Eocene is _ no doubt considerably less than 20 

feet to the mile. Thus the slope of _successive 

buried plains gradually decreases toward the 

top of the geologic time scale. The slope of 

the top of the Oligocene averages only about 

2 feet to the mile, and still youn,ger peneplains 

seem to have average slopes of less than 2 feet 

to the mile. 

Next to the general southwestward tilting 

of the plains and the fact that the older the 

plain the _greater the .slope, the most ·striking 

feature of their warped form consists in the 

decidedly steeper average _slope of the older 

plains south of a belt of counties in th~ latitude of Vicksburg. The downward bend does 

not follow a sharp line but is irregularly developed. On the whole, its course trends 

east-southeastward from Jackson. For the 

older plains it inclines more to the southeast, 

and for the younger plains to the east. The 

slopes of the plains continue to increase southward, and at the present coast even some of 

the Pliocene -buried plains are tilted as much 

as 25 feet to the mile. _ 

~ ot only do the plains slope steeply in the 

south end of the State, but in the centr_al part 

they seem to have been warped i:q_ the opposite 

direction, so that north of Jackson their original gentle seaward and riverwar·d slope has 

been reduced _ to zero or a reversed slope. So 

far it has not been possible to determine the 

details of the warping. Some features suggest that a principal axis of uplift runs from 

Natchez to the northeast corner of the .State, 

and ' another from Mobile northeastward, and 

other features suggest an east-west axis through 

Vicksburg and another through Natchez. 

Perhaps the warping has followed all these 

lines at the same time or at different times. 

Determin~tion must await the preparation of 

topographic maps. _In any case the evidence 

that some of this warping occurred in Pliocene 

time seems. convincing, for both peneplains 

andquasipeneplains, including those which slope 

down into Pliocene deposits, seem to be warped 

upward around Jackson, and features of terraces and the drainage ·confirm the inference. 

TERRACES. 

GENERAL FEATURES. 

The presence of several ancient and high 

gravel terraces; principally along the Mississippi, the deep erosion of these terraces, and 

some other reasons for regarding them _as 

Pliocene have been referred to illnder "Sedimentary record." Apparently there are four 

main Pliocene terraces. All of them are now 

discontinuous, but on account of the facts 

that the terrace remnants are parts of ancient 

valley floors which were evenly graded, and 

that they have not since suffered very great 
PLIOCENE HISTORY OF NORTHERN AND CENTRAL MISSISSIPPI. 155 

deformation, they can be classified and correlated roughly, and if topographic maps were 

available they could no doubt be traced with 

a good degree of certainty. 

The scattered remnants of the terraces were 

followed southward from Illinois through 

Tennessee, Kentucky, and western Mississippi 

to Vicksburg, where they were found to 

broaden and swing abruptly to the east 

across the State and continue into Alabama. 

After a conference with G. C. Matson/ who 

had been working on the late Tertiary deposits of the Gulf coast, it was decided . to 

name the four main terraces as described below and illustrated in figure 24. 

BROOKHAVEN TERRACE. 

The Brookhaven terrace is broad and well 

preserved around Brookhaven, where it now 

lies nearly 500 . feet above the sea. On th~ 

-north it rises gradually for 35 miles to the 

FEET Brookhaven pla in 500 

400 

300 

200 

100 

0 

Horizontal scale 10 20 30 40 MILES 

-500 

Thus• the Brookhaven terrace, or plain, as 

Matson has called its seaward portion, is fully 

60 miles wide and rises northward from 

about 450 feet to more_ than 550 feet, perhaps 

to 600 feet, and then declines to some unknown 

altitude greater than 450 but probably not 

mo:J;'e than 5oo feet. It has been so severely 

deformed and eroded that present information is not sufficient to justify a statement that 

it is not compound. Relative to lower terraces, it is much broader in the east-west 

coast belt than along the Mississippi in the 

central and northern parts of the State, and 

this may be due simply to a difference in resistance of underlying materials, but differences in the process of development n1·ay also 

have played a part, and differences in destructive processes have almost certainly had 

a notable effect. 

North of Vicksburg and Jackson, for the 

width of a county or two, no remnants of the 

FIGURE 24.-Diagrammatic cross section of Pliocene deposits and profile of Pliocene t erraces in the south end of Mississippi. 

southern parts of Hinds and Rankin counties, 

where, notwithstanding the fact that it has 

been severely eroded, its scattered remnants 

still reach 550 feet above the sea. That this 

terrace or some similar gravel-formed surface 

must have once ·extended 20 or 30 miles still 

farther north is indicated by the gravelly soil 

and subsoil of the higher knobs in that belt. 

These knobs are all lower than the remnants of the terrace south of Jackson, apparently for two reasons-the easy erodibility of the Vicksburg and Jackson formations, which underlie this district, and the fact 

that the horizon of the original surface of 

the terrace is lower because of warping than 

in , the vicinity of Star and other places south 

of Jackson. The warping is inferred from the 

position of several plains and terraces but 

particularly from t4at of the younger terraces, 

which are fairly well preserved west and northwest of Jackson. 

1 Matson, G. C., op. cit., pp. 180-186. 

Brookhaven terrace are now known, though 

pebbles tet down from the deposit forming it 

are numerous in many places. North of 

Yazoo County, however, where the underlying formations are the more sandy and resistant Claiborne and Wilcox, scattered remnants 

of the Brookhaven terrace are found as far 

north as Memphis. They seem to decline 

very gradually to the north, or upstream, from 

about 460 to about 430 feet above sea level. 

SARDIS TERRACE. 

The'· Sardis terrace is somewhat better pre- _ 

served than the Brookhaven but is still so 

badly eroded that in the lack of exact topographic data the identification of many of the 

supposed remnants is somewhat doubtful. 

It seems to be practically horizontal and from 

2 to 10 miles wide from Sardis, where it lies 

nearly 400 feet above the sea, to Durant. 

Between Durant and Vicksburg, where no _ 

part of the Brookhaven terrace'remains, there 
156 SHORTER CONTRIBUTIONS TO GENERAL _GEOLOGY, 1917. 

are a few remnants of the Sardis terrace. A 

·few miles southeast of Vicksburg the _terrace 

lies a little more than 400 feet above the sea, 

and east of Natchez it. reaches nearly 450 feet, · 

is 30 to . 40 miles wide, and is fairly well preserved. To the east it becomes narrower and 

slopes to the e~st and south. 

· CANTON TERRACE. 

gentle than that of the present flood plain. 

However, the divergence of th~ two is not 

uniform. 

WARPING OF TERRACES. 

Although many of the terrace ·tops are undoubtedly parts of ancient flood plains, most of 

them differ in gradient from the present flood 

plains of the same streams. On the whole they 

have a more gentle slope, but in some parts of 

In the vicinity of Canton, Miss., there are the State they seem to slope upstream instead 

some very broad, rather flat, upland areas, of down, and these upstream slopes can be acunderlain by sandy clay with gravel here and counted for only by deformation. -

there, at an altitude. of somewhat less than !J.'he Brookhaven terrace seems to be warped 

300 feet above the sea, evidently remnants of a upward as much as 200 feet just south of Jackterrace. To the north the terrace seems to son, where its position reaches 550 feet. Inbe nearly horizontal· or to ris~ very gently to deed, it seems to slope away from this district 

the Tennessee line. To the south the remnants in all directions, but most steeply' to the west 

rise to an altitude of about 370 to 380 feet at a and south. Fifty miles to the northeast it is 

point east of N'atchez. Along the Mi~sissippi · 60 or 70 feet lower. To the east, near. the 

this terrace ranges generally from 1 mile to 10 Alabama line, it is over 100 feet lower, and 

miles in width, though here and there it seems according to Matson 1 this slope continues 

to have been cut away by the lateral swing of across Alabama. Appa,r:ently, however, anthe river. Unlike the older terraces, it seems other and smaller upwarp iE! located north of 

to be fairly well developed along some of the Mobile. Fifty miles south of Jackson the terlarger tributaries, particularly the Big Black. race is ·more than 75 feet lower. To the west 

LOXLEY 'EERRACE. 

The Loxley terrace lies generally 40 to 80 

feet below the Canton terrace, and its general 

slope is slightly greater, or more nearly like that 

of the present·flood plains of the Mississippi and 

other large rivers. In the northern part of the 

State it lies 275 to 300 feet above the sea, or 

100 feet above the present flood plain. To. the · 

south it declines gradually at about the same 

rate as the present flood plain to Yazoo City, 

where its surface buried under the loess is 

about 250 feet above the s.ea. · From Yazoo 

City to Vicksburg it seems to be about horizontal and thus its distance above the present 

stream increases. Farther south · its altitude 

increaSes somewhat rapidly downstream to 

more than 300 feet at a point east of Natchez. 

·Apparently a terrace equivalent in age was well 

developed and is fairly well preserved on 

Pearl, Big Black, Y alobusha, and T~llahatchie 

rivers and on the Tom big bee, .·in the eastern 

part of _ the State. The terrace rises up each 

one of these streams, though its height above 

the present flood ·plain gradually decreases upstream-in other words, on these streams the 

terrace has a downstream slope which is more 

also it declines to about 380 feet in Louisiana. 

The site' of maximum uplift of the later terraces seems to be successively farther and farther southwest toward ' Natchez, and the 

amount of uplift less and less. Perhaps, however, the actual amounts of uplift of each terrace did not differ greatly, but, the effect being 

cumulative, the oldest terrace now shows the 

greatest deformation. . The re~ulting slopes 

have been still further modified by an uplift 

of the ear.liest Pleistocene terrace in the vicinity 

of Natchez.2 

DRAINAGE MODIFICATIONS. 

MISSISSIPPI RIVER. 

During Pliocene time the Mississippi or some 

other large stream· followed the general course 

of the present Mississippi, in the region under 

discussion, as . ·can· be inferred from the remnants of its old deposits and valley floors 

which are preserved in the form of terraces. 

N ev:ertheless the stream differed in several 

.noteworthy respects from the Mississippi of 

to-day. 

1 Matson, G. C., op. cit., p. ISO: 

2Shaw, E .. W., The mud lumps at the mouths of the Mississipri: 

U.S. Geol. Survey :frof. Paper 85, p.IS, 1914. 
PLIOCENE IUST'QRY OF NORTHERN AND CENTRAL MISSISSIPPI. 157 

In early Pliocene time its mouth was far 

· above the site of its present mouths-probably farther north than Natchez, which is 375 

miles by water above the mouths-for (1) the 

general effect of bringing so huge a load of 

sediment as it carries to the sea is to build the 

coast forward, whether or not moderate warping is in progress, though in case of rapid 

downwarping the coast might migrate landward; (2) no Pliocene river ,deposit is known 

south of the southwest corner of Mississippi; and 

(3) a Mississippi River terrace deposit believed 

to be early Pliocene spreads eastward across the 

State 100 miles north of Natchez, indicating 

either a seashore at this latitude or the northern 

boundary of a great and continuous area of land 

sedimentation, for the deposit caps the highest 

divides; and its landward edge, though now 

much frayed, was apparently once straight or 

gently sinuous. 

The volume of the Mississippi was evidently 

much smaller in the Pliocene epoch than now, 

for an extensive area is kno-wn to have been 

added to the northern part of its basin by the 

glaciers of Pleistocene time, and certain topographic features in the upper half of its basin 

including the youthful form of its valley, seem 

to indicate that this added area is consider~ 

ably larger than has generally been supposed. 

'l'he coarseness of the Pliocene deposits of the 

river may also be an indication of lesser volume. 

If its volume was less its gradient was presumably steeper, as the coarse deposits also suggest; and if the gradient was steep~r the inferred deformation which has brought the deposits in places to a horizontal attitude or even 

given them an upstream slope was greater 

. than if the slope had been as gentle as at 

present. However, the gradient of the lower 

half of the Mississippi is not extremely gen tie 

to-day, for the lower Amazon, the lower Nile, 

and even the lower Ohio have gradients as 

slight or slighter. 

The breadth of the Mississippi Valley was 

apparently not so great in Pliocene time as 

to-day, for the terrace remnants of its Pliocene valley floor are small and have evidently 

been severely worn by lateral swings of the 

river. In very few places are all four of the 

main Pliocene terraces represented, and in 

some places all have been worn away. 

In one or several parts of the Pleistocene 

epoch the Mississippi flowed on the west side 

of its valley, ·at times whipping against the 

bluff at Little Rock, and the Ohio joined it 

at some point below Helena, Ark., perhaps 

s'outh of Greenville, :Miss., Crowleys Ridge 

being the divide between the two rivers. . It 

appears probable that a similar arrangement 

existed in Pliocene time, but direct evidence is 

lacking. 

PEARL RIVER. 

The course ,of Pearl River 'lies for the most 

part in the region of the coastal Pliocene deposits, and although precise data concerning 

the form of the valley and the profile of the 

stream are scant it is evident that some anomalous features are displayed in the vicinity 

of Jackson. These features seem to be explained by the upwarps at Jackson and to the 

southwest. In the first place its course has a 

peculiar westward bend at Jackson and its 

main tributaries come from the east, suggesting 

that one or more of its main western tributaries 

have been captured and diverted by the ·Big 

Black. Second,' the smaller southern tribu~ . 

taries of the Big Black are pushing the divide 

close over to the Pearl, whose channel is from 

50 to 100 feet higher than that of the Big 

Black. Third, in the vicinity of Jackson the 

Pearl has a low gradient, a very meandering 

channel, and a swampy flood plain, whereas 

the Big Black and also sections of the Pearl 

abov,e and below this part have a higher 

gradient, a more direct course, and a lesf:) 

swampy flood plain. · In the vicinity of Jackson the Pearl has the appearance of an aggrading stream, which is disproportionately small 

compared with its v~lley, yet it is 250 to 300 

feet' above sea level and the distance that its 

water hasto travel in getting to the sea is 100 

miles shorter than that traveled by the water 

of the Big B~ack. 

These facts suggest that the headwaters of 

the Big Black were once the western headwaters 

of the Pearl. Whether the diversion took place 

near Canton or at some place farther upstream 

·has not , been ascertained. The remarkable 

width of the Canton terrace and the much 

lower general altitude and more subdued surface features around Canton, compared with 

the region around · Jackson, shown on the 

Jackson topographic · map, suggests that the 

stream capture may have occurred in that 

vicinity, and, that the time was late. Pliocene 

or later. 
158 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

BIG BLACK RIVER. 

. In addition to the apparent enlargement of 

its drainage basin one other feature of th~ Big 

Black seems worthy of mention in a paper on 

the Pliocene history of the region. The divide 

between the Tennessee and the headwaters of 

Big Black, Yalobusha, Y ocona, and T~llahatchie rivers is well over toward the Tennessee, · 

the middle and upper portion$ of which are 

much more nearly in line with one of these 

Mississippi rivers than with the lower course of 

the· Tennessee.. On account of . this and other 

considerations Hayes and Campbell 1 have inferred, and many geologists have accepted the 

inference, that the Tennessee once had a southwesterly . course across Missis~ippi. They believe tb,.at "at the close of the Cretaceous cycle 

of erosion" a small river flowed westward 

. across northern Alabama and emptied into the 

sea in the northeast corner of Mississippi; that 

one or more of the head branches of this stream 

to indicate that when they were laid down 

many small streams (or distributaries of ·a few 

large ones) with shifting channels flowed in general southwesterly courses across Mississippi. 

Presumably the Eocene sediments of Mississippi came from the adjoining portion of the 

Appalachian province, which includes .. t~e 

middle and upper parts of the present basm of 

the Tennessee and adjacent territory. There 

is hence reason for assuming that the drainage 

of most of the Tennessee basin in Eocene time, 

and perhaps also in Oligocene time, went sout?-

westward a'cross western Alabama and J\!bssissippi. However, the Oligocene Vicksburg 

limestone and some of the Eocene Jackson 

marl indirectly indicate that at the time of 

their deposition.sand and silt from the southern 

part 'of the Appalachian province was not being 

deposited in the region of their occurrence 

(Mississippi and farther east). 

TOMBIGBEE RIVER. 

then captured some eastern Tennessee drainage Along the Tombigbee· there are somewhat 

that had been going to Mobile Bay; that upon extensive high terraces, particularly in the 

the withdrawal of the sea this stream followed vicinity ofWest Point, Miss., and to the souththe course of the Big Black to the Mississippi. east in Alabama; Beat Creek, a tributary of the 

The northward diversion of the Tennessee in Tennessee in the northeast corner of Mississippi, 

the northeast corner of Mississippi is de- has a strikingly gentle gradient and a broad 

scribed as having occurred in the early part of valley; the divide around the headwaters ofthe 

"the present cycle," a~ter "the Lafayette de- Tombigbee, in the northeast corner of the State, 

pression," which "QCcupied the closing epoch is only 15 or 20 miles 'from the Tennessee; and 

of the Tertiary cycle." 2 northeast of Iuka the Tennessee flows over a 

Although many . details of the ;history of the rocky s{wa1 in a very narrow valley. These 

Tennessee as set forth by Hayes and Campbell facts suggest that the .Tennessee may have 

appear to need modification, numerous facts emptied down the Tombigbee Valley in Plioseem to support the more essential parts of their cene tim~, but if so some parts of the old cour8e 

postulate. The ·Tennessee surely did not flow of the stream have not been found. · It seems 

down the course of the Big Black in Pliocene rather unlikely that Bear Creek occupies a part 

time, for no high terraces seem to be left along of the. old course, for its valley, though wide, is 

the Big Black as a record, and there is no scarcely wide enough for the Tennessee, and if 

abandoned valley between the . two streams. it was cut by a large stream that is now diverted 

Certainly the Tennessee did not flow near Iuka · the diversion must have occurred in Quaterand Tupelo, as shown in their figures. For nary time, for the valley is broad to its bottom. 

similar reasons it seems also certain the Tennes- As Lowe a has pointed out, however, the 

see did not flow down the Y alobusha, Y ocona, higher part of the divide between the major 

or Tallahatchie valleys·in the Pliocene epoch. streams is in some places ''a narrow ridge'' a 

That it did not flow down the Tombigbee, few hundred yards wide and perhaps 50 feet 

however, or even that it did not follow one of high, and it is probable that at a point 4 miles 

the other valleys mentioned, in some earlier below Paden Mackeys Creek, a tributary of the 

epoch, is not clear. The Eocene deposits of Tombigbee, is as low as the Tennessee at the 

Mississippi seem to be largely streani hiid and 

1 Hayes, C. W ., and Campbeli, M. R ., op. cit. 

2 Idem., p. 119. 

a Lowe, E. N.,A diversion scheme to prevent overflows of the Mississippi and to establish a navigable waterway from Mobile Bay to the Ohio 

River, p. 5, 1912. · 
PLIOCENE HISTORY OF NORTHERN AND CENTRAL MISSISSIPPI. 

.A, "' 

~ 

~ 

91° 

32~----~~~~~~~~~-=~L-~~~~~~~~,4~-+~~~~~~rt---~~t---~-p ~ 

~ 

~ 

'\ 

159 . 

· , j 

FIGURE 25.-Sketch map showing shapes of drainage basins in Mississippi. Note particularly that the divide between Mississippi and Tennessee 

rivers is located far to till! east, and that the form of the drainage basin of the Pearl strongly suggests that the upper and middle parts of the 

Big Black basin formerly drained into it. 
160 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, l917. 

north boundary of the State. Lowe states 

that "the total distance * * * from the 

Tennesse~ "·River to··an ··equal•elevation on 

Mackeys' Creek is 29 miles," and the crest of the 

divide is: only about 200 feet above -low water 

on the Tennessee· and considerably less above 

high water. · -

The general shap~ of the drainage basins of 

Missis~ippi, whi~h seems to have been largely 

acquired in Pliocene time, is indicated rn 

figure 25. 

STRUCTURAL RECORD. 

What is· known of the structural record of 

Pliocene time in northern and central Missis.:. 

sippi has been largely outlined in the discussion 

of warped physiographic features. It consists 

of evidence of uplifts in the southwestern part 

of the State and perhaps also along a belt extending northeastward to the northeast corner 

and possibly another uplift whose axis lies in 

southwestern Alabama, affecting the southeast 

corner of the State. Stephenson 1 has found 

evidence of an uplift at Starkville, on the axis 

that is thought to run northeastward from 

Jackson, and such an uplift may have occurred, 

as there seem to .have been 'other movements 

along this axis in Pliocene time. 

The Pliocene uplift along the MemphisCharleston axis suggested by Shaler; 2 described 

by McGee/ and accepted by Hayes and Campbell,4 does not seem to have affected either the 

surface features or the deposits of Mississippi,. 

though it is described as crossing the northern 

part of the State. · 

That a surprisingly large amount of ·deformation of the strata of Mississippi probably occurred in Pliocene or early Pleistocene time is 

~hown by the comparatively much disturbed 

attitudes of the Pliocene deposits and the surface features that are buried -in them or for 

other reasons ·are believed to . date from the · 

Pliocene epoch. 

Hilgard 5 and Crider 6 call attention ·to a 

northward, dip of Eocene and Oligo?ene strata 

1 Stephenson, L. W ., unpublished notes. 

2 Shaler, N .. S., On the causes which have. led to the production of Cape 

Hatteras: Boston So·~. Nat. Hist. Proc., vol. 14, pp. 110-121, 1871. 

a McGee, W J, The Lafayette formation: U.S. Geol. Survey Twelfth 

Ann. Rept;, pt. 1, p. 403, 1891. 

•Hayes, C. W., and Campbell, M.R., op. cit., p. 81. 

o Hilgard, E. W ., Geology and agriculture of Mississippi, p. 128, 1860. 

6 Crider, A. F., Geology and mineral resources of Mississippi: U. S. 

Geol. Survey Bull. 283, p. 34, 1906. 

between Jackson and Canton. Veatch 7 describes a fault with a downthrow on the north 

of about 600 feet that extends from Texas 

through. southern Arkansas and northern 

Louisiana to a point 15 or 20 miles north of 

Vicksburg and forms a continuation: of one 

-in Texas called by Hill .

8 the Red River fault 

and described as having a similar displacement; 

but later work by Stephenson 9 throws doubt 

on · the existence of this fault ill at least a 

part of its ·course. Another structural feature, 

''the Angeline-Caldwell monoclinal flexure, '' is 

described by Veatch as extending southwestward from the same point north of Vicksburg. 

·· However, on account ·of the fact that an 

uplift of the southwestern part of Mississippi is . 

implied by the physiographic features, the 

writer recommended . that an area around 

Vicksburg be examined 'with reference to its 

possibilities of yielding oil and· gas. A survey 10 

was made and the hard rocks were found to 

be bent upward, thus confirming the inferences drawn from surface ·features.- The 

map showmg the structure · of the hard rocks 

gives somewhat more detail than can be inferred from the surface features in the lack of 

topographic_ maps, but still it shows· less 

accurately the movements that have affected 

the rocks, because it includes the effects of 

pre-Pliocene warping and also those of all 

later movements together, whereas from the 

surface features something niay be inferred as 

to the time, place, and _ effect of each movemerit. 

CONCLUSIONS. 

INTERPRETATION OF THE "LAFAYETTE FORMATION." 

In the opinion of the writer, the material 

called "Lafayette formation" in Mississjpp{ is 

the product neither of Pleistocene icy Roods 

from the north nor of a marine invasion; it 

is not a Pliocene blanket of waste from the 

Appalachians gradually spread over the State 

by streams; and it does ~ p.ot consist altogether 

7 Veatch, A. C., Geology and underground water resources ofnorthe~ 

Louisiana and southern Arkansas: U. S. Geol. Survey Prof. Paper 46: 

p; 68, pls. 36, 37, 41, 1906. 

s Hill, R. T ., Geography and geology of the Black and Grand prairies, 

Tex.; U. S. Geol. Survey Twenty-first Ann. Rept., pt. 7, p. 384, 1901. 

9 Stephenson, L; W ., unpublished notes. 

1o Hopkins, 0. B., Structure of the Vicksburg-Jackson area, Miss.: 

u. S. Geol. Survey Bull. 641, pp. 93-120, 1916 (Bull. 641-D). 
PLIOCENE HISTORY OF NORTHERN AND CENTRAL MISSISSIPPI. 161 

of parts of pre-Pliocene formations, with their 

surface ;residuum. It is believed to be made 

up of unrelated or distantly related materials 

that have been erroneously .grouped together 

~nd to consist in the main of more or less 

modified parts of the underlying ·formations, 

including some residuum and colluvium, and 

of terrace deposits of Pliocene and Quaternary 

age. 

DIASTROPHISM. 

Position of surface at begi'[!Jning of epoch.-

The facts that the buried portion of the Pliocene surface is of gentle relief and that the 

tops of monadnocks and other remnants of 

plains are somewhat concordant in altitude 

suggest that at the beginning of the Pliocene 

epoch the surface of ~1ississippi was smoother 

than it is to-day. The coarseness of the 

stream deposits and the nature of the warping 

of the plains and for~ations suggest that at 

that time the surface of central and northern ~ss.issippi, though possibly lower than 

at present, had a considerable and somewhat regular westward and southwar.d slope 

toward ~ssissippi River and the Gulf. 

However, this surface, though perhap& lower 

with reference to sea level, was higher '\\-rith 

reference to the underlying rocks and possibly 

with reference to the earth's center; for it has 

not only suffered local upheaval but has been 

worn down by erosion and perhaps has sunk 

a little, owing to general earth shrinkage. 

Deformation.-The triangular area of which 

Jackson, Vicksburg, and Natchez form the 

corners has certainly been eleva ted in and 

perhaps after Pliocene time, and the place of 

maximum upwarp seems to have shifted southwestward during the epoch, for the deposits and 

plains are not only warped upward, but the 

earliest ones are uplifted most and the center 

of uplift is different for different plains and 

deposits. In addition there ·appear to have 

been a general east-west and a northeastsouthwest belt of uplift through Jackson and 

another region of uplift just east 'of the southeast corner of the State. The maximum 

amount of uplift seems to have been at least 

200 feet, for a terrace seems to rise in a downstream direction to that extent between Yazoo 

City and Star. The uplift seems to have been 

intermittent and to have occurred in four 

principal stages. The great breadth of the 

earliest Pliocene terrace and its height compared with the bordering divides suggest that 

the low relief of the beginning of Pliocene time 

lasted through perhaps a third or a half of the 

epoch before the first of the four uplifts 

occurred. The most pronounced result of all 

the movements is a great steepening of the 

seaward slope of strata and plains of all ages 

in the southern third of the State. Other than 

the depression of the coast region involved in 

this steepening, no downwarps are known to 

have occurred. 

EROSION. 

Weathering and local transportation.~The 

work of meteoric waters and of vegetation 

during the Pliocene epoch was evidently 

manifold. In addition to the main processes 

involved in the production of soil rains and 

consequent rills washed much of the in cohereD. t 

underlying sand and clay down slopes and 

dissolved and carried away much mineral 

matter, both above and below ground; gravity 

through the aid of wetting and drying and 

other agencies, including perhaps freezing and 

thawing, . pulled surface material downhill; 

wetting, aeration, and chemical processes 

weathered the material lying above ground 

water and transported iron oxide and other 

substances, both by solution and mechanically, 

a greater or less distance; and apparently much 

iron oxide that lies near the surface to-day has 

been concentrated downward from strata that 

were worn away in Pliocene time. 

Through transportation and corrasion.-Aside 

from the probably small amount of mineral 

rna tter that has been carried to the sea underground the removal of such ~atter from Mississippi has evidently been accomplished largely 

by streams, though no doubt some material 

has been swept out of the State by wind. The 

general work of erosion has been the gradual 

deepening of valleys, though apparently this 

work has been in places, particularly on the 

Mississippi, subjected to interruptions during 

which considerable deposits were laid down. 

Not only were valleys deepened, however, but 

divides were reduced both by mechanical and 

by chemical agencies. To . judge by processes 

now active the amount of rna terial carried 

away in solution was fully as great as that in 

suspension if not greater. Hence it must be 

assumed that all parts of the region that have 

been exposed since Miocene· t!me have been 
162 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 191'7. 

subjected to a continuous and vigorous process 

of reduction, perhaps to an. extent of 100 tons 

to the square mile each year.1 · It seems reasonable to assume, therefore, that the surface at the 

beginning of Pliocene time was at least 100 

feet above the highest hills remaining, to-day, 

and that much of it was lowered more than: 200 

feet in the Pliocene epoch. _ 

At apparently · four different times the nature of the erosive processes was 'so modified 

that plaihs began to · be formed, though the 

earliest one or two of these times may have 

been in the Miocene epoch. It seems possible 

that the deepening of valleys in Mississippi 

was checked at times when it was accelerated 

in adjoining provinces, for at such times in 

Mississippi through streams would probably 

-be overloaded with · material from their upper 

courses. In any case -erosion developed striking monadnock-like hills in certain sa:ndy 

areas. and cemented their tops with iron oxide. 

In the northeast corner of Mississippi an 

opportunity is afforded for tracing the peneplains of the Appalachain provmce southwestward into the Coastal Plain. A careful study of 

the surface features in and near this part of the 

State suggests that the Highland Rim peneplain; so well developed ill the adjoming portion of the Appala9hain province, is less 

ancient than has generally been supposed. It 

does not seem to be older than the beginning 

of the Pliocene but may be as old as early 

Miocene. A pre-Cretaceous peneplain, however, is apparently' represented by hilltops in 

and near the northeast corner of Mississippi, 

but this plain is preserved because for a large 

part of its existence it was buried beneath the 

Coastal Plain sediments and has 'only recently 

been exposed. There is also indication that a 

peneplain emerges from between the Cretaceous and Tertiary systems in Mi~sissippi and 

passes upward toward the ·northeast but 

slopes less steeply than the pre-Cretaceous 

plain, with the result that the two intersect. 

Both plains no doubt suffered considerable -

denudation in Pliocene time. The Miocene 

0) plain at the tops of the isolated hills rises 

even more gently to the northeast and intersects the other two plains. The still lower 

and younger plains are not yet satisfactorily . 

differentiated, b~t they are nearly horizontal : 

·1 See particularly data on the Pearl at Jackson .given in U.S. Geol. 

Survey Water-Supply Paper 234, p. 87, 1909. 

and, like the older ones, rise to the northea·st, 

each successive one more gently than the preceding and . each intersecting all the older 

plains: 

If the old surface represented by the tops of 

monadnocks is not the Highland Rim peneplain, it must be sli"ghtly younger7 and if so 

that peneplain must cross it and ·slope down _ 

under slightly older sediments. The lack · of 

any indication of such a relation lends support 

to the in terprett1tion that the monadnocks are 

really somewhat' reduced remnants of the 

Highland Rim peneplain. Moreover, if the 

seaward portion of this peneplain passes under 

Pliocene sediments, it must have been formed 

just before Pliocene time, and one piut was 

buried and another carved into monadnocks 

during Pliocene time. 

It seems evident that the present divides, 

which show a comparatively abrupt rise 10 to 

25 miles northeast of Iuka, do not belong to a 

surface of uniform age and origin, but that 

the surface farther northeast is the remnant 

of a plain which was mainly developed upon 

resistant cherty limestone of Mississippian 

(St. Louis and Fort Payne) age and which now 

has a gentle southwesterly slope to a line 

lying about 25 miles northeast of Iuka. Along 

this line the · Highland Rim peneplain intersects a more steeply sloping and ol~er planed 

surface which dips under Cretaceous deposits 

that reach sea · level 15 or 20 miles ·west of 

Iuka. The accordant crests of Mississippi, 

with the possible exception of the monadriock 

tops, evidently belong neither to the Highland Rim peneplain nor to the peneplain finished just before Upper Cretaceous- time. 

However, the -surface of the region when it 

became partly subm-erged in the Upper Cretaceous sea may have been little or no smoother 

thanit has been at.many times before and since. 

Drainage modifications.-The drainage modifications seem to have been continuous and very -

gradual rather than sudden. A portion of the 

Pearl seems to have been captured by the Big 

Black; but the other changes seem to have consisted in a gradual shifting of divides, which is 

suggested by drairiage patterns but can not be 

demonstrated because of lack of topographic-. 

data. Perhaps the inost striking feature of this 

class is the short distance between Tennessee 

River and the divide on th~ southwest side of 

its basin in Mississippi. 
PLIOCENE HISTORY OF NORTHERN AND CENTRAL MISSISSIPJ;>I. 163 

SEDIMENTATION. composition and extent and resemble the terSedimentation in valleys.-Not only did the race deposits of the Mississippi much more than 

streams of Mississippi considerably deepen their those of other streams, and that the surface feavalleys in the Pliocene epoch, but at the same tures consist of about four terraces parallel to 

·time, thoug?- not ~t a uniform rate, they depos- the coast suggesting in some respects the surited much sand and gravel in their valley bot- faces of uplifted compound deltas seem to sugtoms. Apparently, at four stages in particular, - gest marine conditions. On the other hand, the 

the Mississippi received more sand .and gravel facts that the terrace fronts are not well-defined 

than it could carry perhaps because of uplifts of . escarpments' that sea cliffs and beaches seem to 

the Appalachian or Ozark mountains, and as a be lacking, that Pliocene land plants grew at 

consequence it meandered widely, undercutting least as near the present coast a~ Perdido Bay, 

its valley sides and spreading sand and gravel Ala., and perhaps considerably farther south 

over its flood plain. Somewhat extensive than the present coast, that the stratification 

though much dissected remnants of the~e de~ and sorting seem to point to stream rather than 

posits are to be found to-day here and there ocean action, and that nowhere in these depos- -

along the valley side. The overloaded condi- its do there seem to be marine fossils strongly 

tion did not last long, for the deposits do not . suggest land deposition. 

seem tohave been much thicker than the ordinary alluvium along large rivers. Perhaps the 

four terrace deposits correspond to the four 

peneplains that are possibly represented in the 

divides; but it may be that at only two or 

three times of valley filling were plains perceptibly developed and that the older one or two 

peneplains are Miocene~ · 

Coastal sedimentation.-Whether at the beginning of Pliocene time the coast was at the 

northern limit of the Pliocene deposits or 

whether part or all of these sediments are land 

deposits are problems that have not been 

solved, though the balance of evidence seems 

to favor land deposition. The facts that the 

-northern boundary seems to have been a somewhat regular line, that the deposits cross interstream areas, that they are fairly uniform in 

CLIMATE AND LIFE OF THE EPOCH. 

What is lmown of the plants and animals that 

lived in Mississippi in Pliocene time is largely 

set forth in recent papers by Matson and Berry .

1 

The. only additional organic remains worthy of 

mention are petrified logs, such as are fairly 

common in the high terrace deposits of the Mississippi. The climate also seems to have left 

little record except the products of weathering, 

which seem to be in,distinguisha ble from those · 

of to-day. Perhaps some· of the erosion features were produced by changes in climate, but 

they seem more reasonably accounted for by 

deformation. 

1 Matson, G. C., The Pliocene Citronelle formation of the Gulf Coastal 

Plain: U.S. Geol. Survey Prof. Paper 98, pp.167-192, 1916. Berry, E. W ., 

The flora of the Citronelle formation: Idem, pp.193-208. 

0 
DEPARTMENT OF THE INTERIOR 

. FRANKLIN K . . LANE, Secr~tary 

UNITED STAT.ES GEOLOGICAL SURVEY 

GEORGE OTis SMITH, Director · 

Professional Paper 108~1 

STRATIGRAPHY IN SOUTHWESTERN M·AINE AND 

SOUTHEASTERN NEW H.AMPSHIRE 

BY 

FRANK J. KATZ 

Published December 13, 1917 

Shorter contributions to general geology, 1917 

(Pages 165-177) 

WASHINGTON 

GOVERNMENT PRINTING OFFiCE 

1917 
CONTENTS. 

Introduction •......... ... ... : ............... _ .. _ .............. _ ..... ~ .................................. . 

Area .............. - - -. --------- ----- ---- -------------------· · · · -: · · · · · · · --· - -· · · · · · · :-· · · · · · · · · · · · · · Field work ................. _-_ ..... . ... ... .. . ..... . . ..... . ... ~ .......... : ....... . .. , ..... ....... ... . Preyious work ............. _· . . ............ _ . _ . _ . _ . ___ . _ ·. _ . _ . ·_ :. ___ . ____________________ . ___ . _ . _ . ____ _ 

Stratigraphy .............................. .. . _ . _ . _ . _ . _ ... .. _ . _ . _ . _____ . __ .· ____ · _____ . __ . _ . . __ . ___ . ___ ___ _ 

General features ....... : . ........ . . ................... . ..... , ...... ~ .. . ..... ......................... . 

Sedimentary rocks .......... . ... .... ... , ............................... . ........................... ~ .. 

Pre-Carboniferous rocks ...... . ........ . ................... . ............................. _· ...... . 

Berwick.gneiss ..... · .................................. , ............................... ~ .... · .. 

Algonkian_(?) complex .................. .. .............. ·_ ............... _-_ .................. . 

Carboniferous rocks ........ ... _ .. .. ............ ...... ................ ~ ...... ... . .. . ............. . . 

Kittery quartzite •.......... .... ~ ..................... ~ ............................ . .. , .... . 

Eliot slate ......•........ ~ ........... • . . . ......... . ... .... -. -... -. ----------------------------

Casco Bay group .•..... .. .. ..... .' ............... ... , .. . . ·_ .... . ... · . . ..... . c •.•. ·_ ...•••••••• ••• 

General features ....... ...................... . . ....... .. ..... ........................ . . . . 

Cape Elizabeth formation ... ... .......... . ..... -.... ·_ .............. . ........ .............. . 

Spring Point greenstone ....... ·_ .. . ................... ... ................ ... · ........ ..... . 

Diamond Island slate ..... . ............. . .... .. . : .... ....... . ..... ....... . . ..... ...... . . 

Scarboro phyllite .. ...... ~ . ...... .... .............. . ... .... ....................... ·_ ..... . 

Spurwink limestone .. -.............. .... ...................... : ......................... . 

Jewell phyllite ............................ . ... ....... , . ......................... ~ ...... . 

Mackworth slate ......... . .. .. . . .... ....... ... .... ·_ ........ _· .................. -........... . 

Relations of the Casco Bay group .................. . ............... ~ ..... ......... : .... .. . 

Gonic formation . ... ...... .. ... ......... ... _ ....... ... .. , ........................ ... .. , .. _ .. 

Rirrdgemere formation: ......... ........ ~ ................................................ .... . 

Towow formation ..................................... . ............................. '........ . 

Stratigraphic relations and age of the Gonic, Rindgemere, and Towow formations ........... .... . 

Igneous rocks ................................... . ....... . ... . -. .. ..... _ .. . _ . ... : .................... . 

Westbrook granite and Falmouth pegmatite .................. , . .. ~ ............... : ..... ... ........ . 

Igneous rocks of the Algonkian (?) complex .............................................. -........ . 

Cushing granodiorite ................. _ ................ ..... .. ....... ....... ... .... . ............ . 

Altered basic dikes .. ." ............................................ _ ......... · . .... .......... . _·_ .. . 

Diorite in Saco .......... ........ ~. _ ............................ · ........ : .... ... ... .... ......... . 

Exeter diorite ....... , .............. ... ............... .. ........ . ....... . ..... ... ... . .. , . .......... . 

Biddeford granite ............................................................. .......... __ .... . 

Other granites ...... .... ........... ............... . .... ......... ... _._ .. ..... . ............. ..... . 

Trap dike.s ................ ~ ...... -: .................... ' ...... -..... -. -. --- --- - - . -- --- -. -. --- - --

ILLUSTRATIONS. 

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Page. 

PLATE LXI. Geologic sketch map of southwe~tern M~ine and southeastern New Hampshire.................. 168 

FIGURE 26. Index map showing area in southwestern Maine and southeastern New Hampshire................ 165 

II 
STRATIGRAPHY IN SOUTHWESTERN MAINE AND SOUTHEASTERN NEW 

HAMPSHI~E . .. 

By FRANK J. KATz. 

INTRODUCTION. 

Area.-The region discussed in this paper 

includes some 1,500 square miles, most of which 

is in the southwest corner of Maine, in Cumberland and York counties, the remainder being 

in the adjacent parts of Strafford and Rockingham counties, N. H. The area lies between 

67° 

__L_ -~(J---j43 

!.., ' 

\ r~ 

2~ 25 50 75 IOOMILES 

FIGURE 26.-Index map showing area in southwestern Maine and southeastern New Hampshire. 

meridians 70° and71 ° arid parallels 43° and 43° 

45', which inclose the Casco Bay, Portland, 

Buxton, Newfield, Biddeford, Kennebunkport, 

Berwick, York, and Dover quadrangles of the 

United States Geological Survey topographic 

atlas. _(See fig. 26.) -

100330°-17 

Field work.-The conclusions on this region 

here set forth are the result of wor~ begun in 

July, 1911, and still in progress. The field 

work has included critical study and detailed · 

mapping of about one-third of the area and 

reconnaissance examination of the remainder. 

This work was under the direction of Mr. Arthur 

Keith, who has conferred frequently in the 

field and office with the writer and whose 

encouragement and assistance contributed to 

its progress. Mr. Laurence LaForge, who has 

long · been studying areas in New Hampshire 

and Massachusetts soU:-:!}lwest of the region here 

considered, has also contributed to the results 

by field conferences and by critical discussions. 

The writer gratefully acknowledges indebtedness to both these geologists. 

Previouswork.-Little geologic work had been 

done previously in southwestern Maine and the 

adjacentpart of New Hampshire, and there are 

no published conclusions of present interest 

except those of Charles. H. Hitchcock/ which 

can be briefly summarized as follows: 

Hitchcock elaborated the views of his father, 

Edward Hitchcock, on the geology of the 

vicinity of Portland, Maine, and following him 

divided the rocks of the region on the basis of 

lithology into a number of varieties of schists 

and assigned them to his Huronian and Cambrian, or Paleozoic ( ~). Furthermore, he recognized these sedimentary rocks of the Portland 

and Casco Bay region as distinct from those of 

adjacent areas. The gneisses to the north and 

west of the Portland rocks he assigned to the 

"Laurentian or Azoic," but later he_ correlated 

part of these gneis~es with his Coos group 

(Paleozoic) _of New Hampshire. He further 

1 Hitchcock, C. H., General report upon the geology of Maine: Maine 

Board Agr. Sixth Ann. Rept., pp. 146-328, 1861; The geology of Portland 

(Maine]: Am. Assoc. Adv. Sci. Proc., vol. 2, pt. 2, pp. 163-175, 1874; The 

geology of New Hampshire, pt. 2, Stratigraphical geology; and atlas; 

Concord, N.H., 1877; Geology of northern New England (Maine, with 

map), 1885; The geology of New Hampshire: .Jour. Geology, vol. 4, pp. 

44-52, 1896. 

165 
166 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

-noted in York County, Maine, the continuation 

of his Merrimack slates ("flinty slates") of New 

Hampshire, and northwest of these in Maine 

and New Hampshire, in the vicinity of Rochester and elsewhere, he mapped and described the 

"Rockingham mica schists" and "Kearsarge 

group" (andalusite schists), both of which he 

stated to be more or less equivalent to his· 

Merrimack slates and related to the Huronian 

as well as the Cambrian but referred-doubtfully 

to the Paleozoic. The relation of Hitchcock's 

several subdivisions and his petrographic units 

. can not bereconciled with those of'the present 

paper. An attempt is made, howe.ver, by 

means of footnotes in the stratigraphic table to 

indicate so far as possible the correspondence 

of his subdivisions. · 

STRATIGRAPHY. 

GENERAL FEATURES. 

The region under discussion is a part of the 

New England coastal lowland, here a belt 10 to 

25 miles wide, whose rock surface is abundantly 

mantled with glacial drift and over broad areas 

deeply buried under outwash deposits, both 

terrestrial and marine, of late Pleistocene age.t 

This condition, with the further handicap th'at 

the sedimentary rocks so far as known are nonfossiliferous and are metamorphosed to an 

extent which makes · the discovery of fossils 

improbable, is a considerable hindrance to 

stratigraphic work. However, over a large 

part of the regipn outcrops are found at intervals short enough for positive correlation on the 

basis of pronounced lithologic characteristics, 

and furthermore, although the structure is 

complex in detail, the region shows a dominant 

and_simple major structure-that of elongated 

folds on approximatefy paralle~ northeast 

axes-which is of assistance in tracing and correlating stratigraphic units. The rocks include 

(1) an assemblage of more or less severely deformed and metamorphosed sediments, with 

which are associated some volcanic rna terials, 

and (2) a number of types of intrusive rooks, 

some of which also are metamorphosed. None 

· of the rooks have been sufficiently altered by 

mashing and recrystallization to lose their 

original character completely. 

1 Katz, F.'J'., and Keith, Arthur, The Newington moraine, Mairie 

N.H., and Mass.: U. S. Geol. Survey Prof. Paper 108', pp. 11-29, 1917 

(Prof. Paper 108-B). 

The differenti~tion of the sedimentary formations a~d their classification and mapping have 

been based upon recognition of t:t ·general and. 

characteristic lithologic facies for each formation, upon careful consideratio~ of their petrographic similarities and differences, upon 

cautious use of character and degrees of deformation and metamorphism as crit,eria, and upon 

areal di~tribution as interpreted in the light of 

distinguishable structure. Thus eight cartographic units have been recognized.. The igneous rocks are roughly grouped by means of 

their obvious petrographic features, areal distribution, and relation to the sedirllents. The . , 

resulting classification of the rocks and their 

stratigraphic relations and equivalences are 

shown in the accompanying table. 

The map (Pl. LXI), on account of its small 

scale and the lack of precise data in a large 'part 

of the area, is very much generalized as to position and minor features of the formation boundaries. Because of lack of outcrops the following 

parts are wholly arbitrary and inferential: 

The southwest termination of the Towow 

formation in Lebanon, ·Maine; the approximately north-south line which bounds part of 

the Berwick gneiss and ·cuts ·off the Carboniferous rocks in Rollinsford . and Somersworth, 

N. H.; and the line between the Casco Bay 

group and the Kittery quartzite in Biddeford 

and Saco, Maine. The igneous rocks are represented as continuous over some areas, and · 

their boundaries are drawn with solid and 

smooth lines where they'· have most irregular 

outlines and ·partly or wholly include large 

blocks of sediments. Furthermere, the relations of formations at contacts, whether of intrusion, faulting, conformable succession, or otherwise, are nowhere indicated by the character . 

of the lines on the map. With these exceptions, 

however, the map is presented with considerable assurance that it conforms generally with 

the facts. 

SEDIMENTARY ROCKS. 

PRE-CARBONIFEROUS ROCKS. 

BERWICK GNEISS. 

The Berwick gneiss, named from the town of 

Berwick, Maine, occupies a continuous belt in 

the central and northeastern parts of the region 

here discussed and extends both northeast and 

southwest for undetermined distances. The 
Carboniferous 

(Pennsylvanian(?). 

Pre- Carbonif- erous. 

For. .. tions in southwestern Maine and southeastern New HampBh'l>'re. 

Sedimentary rocks. 

Casco Bay group: a Mackworth s!ate: Qu.artzites and q~artz slates, 200 feet(?) .. Jewellr:hyl~tte: b SIIIC~ous and argillaceous slates and phyllites, 500 feet(?). 

Spurwtnk ltme~tone: Limestone and phyllites, 200feet (?). 

Scarboro phylltte: Black and gray argil- laceous phyllite, 200-600 feet. . Towow formation: Black carbonaceous 

Diamond Island slate: Black carbona- Elwtslate:c Gray quartz slate and phyllite, 200-300 

ceous quartz slate, 75-150 feet. slates, c~lc;a- ~eet (?). . Sprinp Point greenstone: Hornblende reou~ argillite Rt'ndgemere formatwn: d Dark-gray car- schists, etc., 0-600 feet. (lfadite), and bonaceous phyllites, slates, grayCaJ!e. Elizabeth formation: Graywacke, ~ ack phyl- w~cke, and_quartzite, 1,000 feet(?). 

siliceous slates, and argillaceous hte. Gon~c form_atwn:e Gray~acke schists, . slates and phyllites, 600 feet(?). miCaschists,andphylhtes, 500feet(?). 

Ktttery quartzite: I Quartzite, argillite, slate, and schist, 1,500 feet(?). 

Quartzites with rhyolite flows and tuffs; slates, schists, and hornblende schists; quartzite and graywacke 

gneisses of Algonkian (?) age.Y 

Berwick gneiss:h Graywacke gneisses and schists and quartzite. 

a C. H. Hitchcock's Huronian and Cambrian in the vicinity of Portland, except as indicated in note b. 

b Part of this formation in Saco is C. H. Hitchcock's Cambrian slate. c Included in C. H. Hitchcock's Merrimack slates. 

Triassic. 

Post- Carbonif- erous. 

Late Carboniferous(?). 

Unknown 

(probably 

pre - CarbonIferous). 

Unknown (postBerwick). 

d Approximately equivalent to C. H. Hitchcock's Kearsarge group in the vicinity of Rochester (a part of his Huronian and Cambrian or Paleozoic?). e Iricluded in C. H. Hitchcock's Rockingham schist (a part of his Huronian and Cambrian or Paleozoic?). 

Igneous rocks. 

Gabbro, diabase, and other 

dikes. 

Gneissoid biotite- muscovite 

granites and pegmatites in 

Milton, Lebanon, Acton, Sanford, etc. 

Biotite granites in Lyman, Alfred, Dayton, and Rochester. 

The assemblage in Mount Agamenticus; biotite granites, 

gabbros, and other differentiates in Wells, South Ber~ 

wick, and York. 

Biddeford granite: Mediumgramed biotite granite and 

/ pegmatite in Biddeford, Kennebunk, etc. 

Exeter diorite: Fine to medi urn grained light-gray diorite in 

Rollinsford, Dover, Newmarket, Exeter, etc. 

Medium io coarse, pariiy gneissoid diorite in Saco. 

Basic dikes. 

C u s h i n g granodiorite: Finegrained porphyritic gneissoid 

granodiorite. 

White(tourmalinic)pegmatites. 

Fine-grained muscoVIte granites. 

Coarse biotite granites, augen 

gneiss. 

Fine-grained diorite, etc. 

Westbrook granite and Falmouth 

pegmatite: Gneissoid biotite 

granite and white tourmalinegarnet pegmatite. 

I Included in C. H. Hitchcock's Merrimack slates and Rockingham schist (a part of his Huronian and Cambrian or Paleozoic?). g Included in C. H. Hitchcock's Merrimack slates. · h That part in New Hampshire and York County, Maine, placed by C. H. Hitchcock in his Merrimack slates and Rockingham schist (a part of his Huronian and Cambrian or Paleozoic?); that in the Portland 

region partly in his Laurentian or Azoic and partly in his Coos group or Paleozoic. 

100330°-17. (To face page 166.) 
,· 
I 

STRATIGRAPHY IN SOUTHWEST~RN MAINE AND SOUTHEASTERN N:EjW HAMPSHIRE. 167 

belt ranges in width from 2! miles at the south- toward the southeast on approxim~te parallel 

west, on the west side of the Dover quadrangle, northeasterly axes. ·.· In very small areas a few 

to at least 9 miles at the northeast, where it wide departures from the prevailing attitude 

occupies the northwest corner of the Casco indicate local intricacies in structure. 

Bay quadrangle, the northwest half of the Port- Along its southeast border the Berwick· 

land quadrangle, and the east half of the Bux- gneiss within this region is in contact with 

ton quadrangle. the Casco Bay group, with the partly equivaThe formation is composed chiefly of gray- lent slates in Dover, Madbury, and Lee, and 

wacke gneiss but contains also. clean quartzit~s, with the Kittery quartzite. Its north and 

micaceous quartzites, mica schist, and argillite northwest boundaries have not been deterschist and slate. The beds range from about an mined except in the Dover, Berwick, ' and 

inch to a few feet in thickness. Almost all the Kennebunkport quac!rangles, where it is adrocks are · moderately fine grained and deli- joined on the northwe.st by the Gonic forcately banded. . Their colors are medium to mation. Several bodies of massive granitic 

dark gray, bluish gray, and brown. In the and dioritic rocks are intrusive in the BerWick 

P_ortland · quadrangle a few layers, 1 to 3 and also cut younger fqrm~tio~s. In the 

inches thick, of light-blue and white crystalline northwestern part of the region there are 

limestone have been found. The most abun...: bodies of intrusive gneissic granite and pegdant and characteristic rocks are moderately matite, which are restricted to the area of the 

fine grained banded gray and bluish-gray gray- Berwick. Its greater deformation and more 

wacke or quartz-feldspar-biotite gneiss and complex structure, its notably greater metamicaceous quartzite~ Th~ formation is marked morphism, and the presence in it of deformed 

by a high degree of . crystallinity, by an a bun- intrusives not known to invade other for-

. dance of metamorphically developed biotite, mations show that the Berwick gneiss is older 

and in places by actinolite in graywacke and than the sedimentary formations which adjoin 

quartzite. Many of the beds are flecked with it. Evidep.ce is lacking to determine whet~er 

metacrysts of bl~ck biotite. The most dis- .the juxtapositions are due to unconformity or 

.tinctively characteristic alteration is a recrys- to faUlting. There are also no data on the 

tallization of the graywacke into nonfoliate · relative stratigraphic positions of the Berdiorite-like aggregates which contain chiefly wick gneiss ahd the other pre-Carboniferous 

quartz, feldspar, and hornblende and in some sediments. The age of the Berwick gneiss is 

places also garnet and which have the form of unknown. 

seam selvages or bands, lenses, and small spheroidal and irregular patches. On the northwest ALGONKIAN (l) COMPLEX. 

end of the belt, in parts of the Buxton, Port- In the southeastern part of the region a 

·land, and Casco Bay quadrangles and farther · greatly metamorphosed crystalline complex 

north, where this formation is heavily injected occupies a belt It to 4! miles wide trending 

by granite and pegmatite, it is metamorphosed northeast to east-northeast along' the coast 

to wholly crystalline quartz-biotite and quartz- in Gerrish Island, Maine, the islands in the ' 

feldspar-biotite gneisses of fine· t9 medium mouth of · Piscataqua River, New Castle, 

gra1n. and Rye, and parts . of Portsmouth, North 

The thickness of the Berwick gneiss is not Hampton, and Greenland, N. H. Among the 

determinable. stratiform rocks of this complex there have 

From the p~evailing northeast strikes, which been recognized fine-grained gray and whitish 

range, however, from nearly north to nearly quartzites associated with rhyolite flows and 

east, with dips generally moderate to steep breccias; see~ningly overlying dark-colored 

toward the northwest but in some places steep banded slate and Bchist, including abundant 

toward the southeast, and from intricate crum- hornblendic schist, which in turn appear to 

piing and close folding on northeasterly axes overlie medium to coarse grained micaceous 

discernible ·only in, some exposures of thin- quartzite and . graywacke. In these rocks the 

bedded members, the Berwick gneiss is in- cleavage is almost uniformly ver:tical or 

ferred to be closely folded and overturned has a very steep dip; it seems to be parallel 
168: SHORTER CONTRIBUTIONS TO GENERA~ GEOLOGY, 1917. 

to the bedding wherever that is discernible, 

and the strike of both cleavage and bedding 

swings from northeast on the south end of 

the belt to nearly east on the north end. 

All these rocks are intruded by large masses 

and interleaved with layers of a variety of 

granitic and some dioritic rocks, which are 

generally deformed and more or less foliated. 

The stratiform rocks of this complex lie in 

the general trend of the belt of outcrops· of 

presumed pre-Cambrian (Algonkian~) f~rmations, the Westboro quartzite and Marlboro 

formation of eastern Mass.achusetts,t and are 

very probably counterpar,ts .. of those formations. The areal relation&'and'the similarities 2 

in lithology and assoe:iation of ·the rocks in 

_ Rye and Portsmouth, N. H., to those of the 

Algonkian0) in eastern Massachusetts afford 

the basis for tentative assignment of these 

rocks in Maine and New Hampshire to the 

Algonkian. 

CARBONIFEROUS ROCKS. 

- lOTTERY QUARTZITE. 

The Kittery quartzite, named from the town 

of Kittery, Maine, in which typical exposures 

abound, occupies a 45-mile belt from Exeter; 

N .. H., to Saco, Maine. This belt is 7 to 13 

miles wide and lies along the coast, except for 

about 11 miles in the southeastern part, in 

Kittery, Portsmouth, Greenland, · Rye, and 

·North-Hampton, where pre-Carboniferous rocks 

intervene, and thence continues inland southwestward beyond ·the region here considered. 

Within this belt, especially along the coast, the 

exposures of the quartzite are practically continuous, being interrupted only by two very 

large and several small areas of granitic rocks 

and an area of slate described on pages169-170. 

Within the granite areas, particularly along 

their coastward sides, are many inclusions and 

large . engulfed blocks of. Kittery quartzite, 

which ·assist in establishing the continuity of 

the formation. · · . . 

This formation consists of banded flinty and 

vitreous quartzites, subordinate amounts of 

argillitic and micaceous quartzites, some argillite, and very thin beds of micaceous slate and 

1 Emerson, B. K., Geology of Massachusetts and· Rhode land~ 

U. S. Geol. Survey Bull. 597 (in press). 

2 Laurence LaForge, who has examined the rocks in both regions, 

has in personal communications reported these similarities. 

schist. .All these rocks are very fine grained. 

The formation is characteristically thin bedded, 

few of the beds exceeding 2 feet in thickness, 

and the thicker beds are generally marked par--

allel to the bedding by thin layers 9f different 

colors. The most striking feature of the formation is a fine interbanding of various tones of 

dark gray, bluish, chocolate-brown, and black 

with a little light gray E:tnd white. . On weathered surfaces there is an equally characteristic 

and more pronounced interbanding of white, 

drab, green, blue, and chocolate-broWn.. _ The 

dark-gray and brownish beds in particular are 

in many places banded, mottled, and intricately patterned in drab shades as the result of 

leaching and silicification, and argilli tic beds are 

commonly dotted with small variously colored 

spots.' The Kittery quartzite is only slightly 

metamorphosed; excppt in relatively few included thin beds of micaceous schist, recrystallization and foliation are weakly developed. 

Se.veral-exposures -of the Kittery quartzite 

show that it has been folded into a great number · of small open to ·moderately close rolling 

folds that trend northeast in most places buteast-northeast in Kittery and nearly east naar 

Biddeford Pool. Generally, however, the only . 

observable structure is a northeasterly strike. 

and vertical or high dips. Over small areas, 

notably near Ogunquit, Maine, and thence 

northward along the coast, and on Fox Point 

in Newington, N. H., there is considerable irregularity and departure from the normal strike 

and dips. The few data obtained along the 

west border of the granite in the Dover quadrangle indicate that the quartzite lies vertically 

against the granite or dips away from it. A 

few observations made in Portsmouth and 

Eliot along the east side of the Eliot slate (see 

p. 169) indicate that the quartzite dips toward 

(under) the slate~ _ 

No reliable measurement of the thickness of 

the Kittery quartzite is possible. The best 

estim.ate, made. at York Harbor, where .there is 

no evidence of repetition of beds, indicates a 

minimum of 1,500 feet at that place. 

The Kittery quartzite is bounded by diorite, 

granite, a:n,d gabbro, which intrude it; by the 

slate in Eliot, Newington, Dover, Stratham, and 

Exeter; arid the rocks of the Casco Bay group, 

which conformably overlie it; along most of" its 

northwest boundary by the Berwick gneiss, 
U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE LXI 

IGNEOUS ROCKS 

SEDIMENTARY ROCKS 

M.ackw-orth s1ate 

Jewell phyllite 

Spurw:ink limestone • CascoBay group 

Scarboro phy1lite i 

Cupe.Ehzabeth 

Dw.mond 

Spring Pomt 

Island 

greenstone 

formation 

slate j' 

Eliot 

~ 

~ 

slare 

Kittery quart7..ite 

orik:ian ~ ti'ICOlnple.x of r~(irke !!neiss, wrill>1 ndt' I:khist, qunrtzi .t·hrol it • nnrl wf 

rrrttn. tJ w e aro i7 ~<lnded 

p~yrnal''l~. granUe, dwrite, aJ.ldflf"(UUU gt te£.5~ 

~ 1. 

C<_'lle 375,000 

:-;::-.;:~~ 

":-;::-.;: "' "\·'"" ~~ 

Towow formation 

' 

' 

Rlnd~emere ormation 

~ 

Goni~ c fmmation 

Berwick gnei, , st=~~==~~=io============ 5============~1oM iles 

GEOLOGIC SKETCH MAP OF SOUTHWESTERN MAINE AND SOUTHEASTERN NEW HAMPSHIRE. 
STRATIGRAPHY IN SOUTHWESTERN MAINE AND SOUTHEASTERN NEW HAMPSHIRE. 169 

against which it is either faulted or is in unconformable superposition; ·and by the other preCarboniferous sediments, with which its relations,are unknown. The intrusive contacts are 

• exhibited and conclusively established in several exposures. _ The 9onformable relation of 

the overlying slate in Eliot and elsewhere is 

inferred from two facts-(1) the greater abundance of argillite in the Kittery quartzite ·near 

the exposures of Eliot slate in Eliot Neck and 

-in the vicinity of York River, which suggests 

transition of lithologic character from one to 

the other, and (2) the areal distribution and the 

apparent attitude of the quartzite with.relation 

to the slate. The quartzite surrounds the slate 

with approximately pttrallel strike and seems 

to dip toward it. The areal distribution of the 

quartzite and slate with respect to the granitic 

masses-that of successive surrounding belts~ 

also indicates the same relation. (See map, 

Pl. LXI.) For similar reasons the rocks of the 

Casco Bay group are inferred to overlie the Kittery quartzite, probably conformably, because 

the basal formations of that group are probably 

equivalent to the Eliot slate. · According to 

Mr. LaForge, outcrops across the Newburyport 

and Haverhill quadrangles, Mass., indicate that 

the belt of Kittery quartzite and overlying slate 

extends southwestward to . Merrimack River 

and is continuous with the Carboniferous Merrimack quartzite.1 The quartzite facies in the 

vicinity of Lowell, Mass., and in Kittery, Maine, 

are lithologically identical, but the Merrimack 

quartzite as defined and mapped in the work 

cited includes some slate and phyllite, which 

are very probably equivalent to those in the 

Eliot slate. , By correlation with the Merrimack quartzite, the Kittery quartzite and overlying slate are assigned to the Carboniferous 

period. , 

ELIOT SLATE. 

The - Eliot slate, named from the town of 

Eliot, Maine, occupies two parallel belts trending southwest through about 13 miles-one in 

Eliot and Kittery, Maine, and extending thence 

through Dover and Newington into Stratham 

and Exeter, N. H.; the otP,er in Dover, Madbury, Durham, and Lee, N. H. Both extend 

southwestward for undetermined , distances 

beyond the limits of the region here considered. 

-These belts are 2 to 5 miles and half a mile to 3 

1 Emerson, B. K., op. cit. 

miles wide, respectively, and are separated by 

a 3 to 5 mile belt of Kittery quartzite and intruded diorite. 

The rocks of both belts are identical in all 

respects, comprising an assemblage of gray 

sericitic and siliceous sericitic slates; beds of 

light-gray and drab argillo-quartzitic rocks, 

some of which are also calcareous; thin laminae 

of light-bluish limestone; .and thin layers of 

black carbonaceous sericite phyllite. Almost 

the whole formation is uniformly fine grained 

and thin bedded. In the central part of the 

eastern -belt, and presumably at the highest 

horizons in the formation, the black sericite 

phyllite layers are more abundant and thicker 

than elsewhere. 

The thickness of the Eliot slate is not determinable; there 'are no formations overlying it, 

and its top may be absent. 

The Eliot slate has the appearance of greater 

deformation and schistosity than the Kittery . 

quartzite, but this appearance is due to the 

fact that the formation is predominantly thin 

bedded and argillaceous; deformation has produced about the same degree of metamorphism 

in the Eliot slate as in the similar thin-bedded -

argillaceous rocks in the Kittery quartzite. 

The Eliot slate is somewhat_ less deformed 

structurally and less well recrystallized than 

the Casco _Bay group. 

Where discernible the strike of the bedding 

of the Eliot slate is almost uniformly northeast 

and the dip vertical or very high to the northwest; small folds pitch gently southwest. In a 

few areas there are easterly strikes indicating 

local folds. The structure of the eastern belt 

is inferred to be synclinal, the slate being infolded in the Kittery quartzite, as indicated in 

the discussion of that formation. 

The Eliot slate is in contact with the Berwick 

gneiss along a straight northeastward-trending· 

boundary of unknown structural significance; 

with a diorite by which it is intruded in Dover 

.and Exeter, N.H., and intervening towns; and 

with the Kittery quartzite, which it overlies 

conformably. It is therefore of Carboniferous 

age. The Eliot slate is correlated with the 

lower part of the Casco Bay group, more particularly with the Cape Elizabeth formation, on 

the basis of very close lithologic similarity, expressed not only in the colors, texture, and composition of the various rocks but also roughly in 

the proportions of each and the manner of inter-
. 4 

170 SHORTER CONTRIBUTIONS TO GENERAL . GEOLOGY, 1917. 

lamination of the thin layers of .black phyllite 

and calcareous beds. 'There is, however, a 

greater abundance of black phyllite in the upper 

part of the Eliot slate, ·which gives it an approach in character to the Scarboro portion of 

the Casco Bay group. Hence the 'Eliot slate 

does not appear to be preci~ely equivalent to 

the Cape Elizabeth formation but may repre ... 

sent also a part of the Scarboro phyllite. It is 

therefore given a separate name. · · 

CASCO BAY GROUP. · 

General features._:_The Casco Bay · group 

-derives its name from Casco. Bay, Maine, in and 

around which its parts are· well developed. 

The rocks of the group are limited ·in their distribution to the northeastern part of the region 

here considered, where they occupy: a compact 

area about 30 miles long and 12 miles wide, 

including the extreme northeast corner of the 

Kennebunk quadrangle, the north edge of the 

Biddeford quadrangle, the southeast half of the 

Portland quadrangle, and all but the northwest 

· corner of the Casco Bay quadrangle. From the 

central part of this area is excluded a strip, occupied by mtrusive granodiorite, some 16 miles 

long and as · much -as 3 miles wide, in Cape 

Elizabeth and the central islands of Casco Bay. 

The Casco Bay group has an aggregate thick-

:qess of 1,500 to 2,000 feet and consists of slate, 

phyllite, and schist, -dominantly of argillaceous 

origin; siliceous slate, graywacke, and quartzite; calcareous beds; and some greenstone and 

associated schist, probably of volcanic origin. 

-These rocks are divided into seven formations, 

as described below. . · 

Cape Elizabeth formation,-The Cape Elizabeth formation, the lowest unit in the Casco 

Bay group, is named from Cape -Elizabeth, 

Maine, where it is best and most~ completely 

exposed. The formation · crops out in many 

other places throughout the area occupied by 

the Casco Bay group. The Cape Elizabeth formation is an assemblage of mostly thin-bedded 

light-gray siliceous and sericitic slates, heavier 

beds of graywacke slate, schist, and quartzite, 

and it contains at short intervals thin layers or 

laminae of black n1icaceous phyllite and lightbluish calcareous schist or slate. Near High 

Head, on Cape Elizabeth, the lowest exposed 

parts contain about 10 feet of massive drab 

graywacke or quartzite, succeeded by 12 to 15 

feet of gray slate and sericite phyllite, with oaloare~us _laminae, followed by about ·the same 

thickness of gray ·sericite--quartz phyllite containing thin layers of blackish phyllite. Above 

these are thin layers of fine gray sericite-quartz 

slate iriterbe~ded with coarse-grained gray- . 

waoke·slate in beds 1 tQ 2 inches thick. These 

beds are succeeded by a considerable thickn.ess 

(not ·measuiable) tnade up chiefly of gray sericite·· slate and schist, which are finer grained, 

darker colored; and more mieaceous toward the 

top~ In other localities the formation contains 

beds of gneissic micaceous (biotite) quartzite, 

1 to 3 or 4 feet thick; · garnetiferous mica schist; 

and finely intermingled micaceous and siliceous 

schists. · The thickness of the Cape Elizabeth 

formation is difficult' to estimate but seems to be 

about 600 feet, whiohissuffioient to account for 

all exposures, for•ialthough they cover large 

areas the dips· are in the aggregate very low. 

Spring Point greenstone.-The Spring Point 

greenstone, which lies a_bove the Cape Elizabeth 

formation; is named from Spring Point, South 

Portland, 'Maine;.' :It is made up of gray to 

dark-green actinolite schist, in part thoroughly . 

schistose and in part somewhat massive; chlo.;.. 

ritic schists; ana some schistose rocks that still 

show j ·their'· origmal· coarsely ·and irregularly 

fragmenta.l texture and contain seoondary felts 

of small actinolite needles and small blebs ofblue quartz. In 'composition and texture the 

more ·massive phases resemble moderately 

mafic 'igneous rooks· and the schistose fragmental varieties resemble ·tuff, agglomerate,- or flow 

breccia. · The formation is very probably volcanic material locally but oonfonnably intercalated between the~' Cape Elizabeth formation 

and the Dianiondisland slate. Its distribution 

is not so wide :as that of the other formationsthat is, it is ·not found in aU places where its 

horizon is exposed but chiefly oniy in the cen:-

tral part of the Portland region in parts of Port:.. 

land, Bouth Portland, Cape Elizabeth, and 

southe~stern Scarboro. Its thickness is irregular but attains a maximum of probably 600 

feet'. 

Diamond Island slate.-The Diamond Island 

slate is named from Great Diamond Island and 

Little Diamond Island, in Casco Bay, where it 

is typically' exposed. It conformably _ overlies 

the Spring Point· greenstone but is more extensive than that formation aii.d also overlies 

directly the Cape Elizabeth formation in the 

northeastern part of Casco Bay and ill the 
STRATIGRAPHY IN -SOUTHWESTERN MAINE AND SOUTHEASTERN N-EW HAMPSHIRE. · 171 

southern part of Cape Elizabeth Township. 

The Diamond Island slate seems to be continuously developed in a tract 6! miles wide 

and 18 miles long within the region examined 

and to extend for an undetermined distance 

nor~heast; but the formation is not known 

and is seemingly not developed at its horizon 

in Richmond Island and in -the western part 

of the · area occupied by the Casco Bay group. 

The formation is made up in major part of a 

black pyritiferous, graphitic, and slightly 

micaceous quartz slate of very fine grain and 

in -lesser part of a black or bluish-black, somewhat graphitic and also pyritiferous quartzsericite phyllite. The rock is characteristically 

black and studded with small masses and 

crystals .of pyrite, which weather out on the 

surface 'of exposures and give rise to abundant 

copperas and rust . coatirigs. Equally characteristic of the Diamond Islarid slate are intricate 

crumpling on a small scale and an abundance of 

small crumpled quartz veins. Estimates based 

on width of outcrops where the beds are 

vertical indicate a thickness betw~e~ 75 and 

150 feet. --

Scarboro phyllite.-The . Scarboro . phyllite 

takes its name from _the town o'f Scarboro, 

Maine, in which it crops out abundantly, par-

. ticularly in the vicinity of Scarboro Beach, 

where the several 'phases of the phyllite are 

exposed. The Scarboro phyllite overlies the 

Diamond Island slate and the Cape Elizabeth 

formation. It consists of , uniformly fine.., 

grained sericite phyllite, for the most ·part 

dark bluish gray to black from the presence 

of biotite . and carbonaceous :matter, but 

locally light gray and white in the upper half 

of the formation. The rocks are typically not 

siliceous. .They are in places somewhat garnetiferous; and the dark-colored parts are in 

generalheavily impregnated with pyrite. The 

presence of vein quartz in chunky lenticles and 

irregularly contorted seams is characteristic, as 

are also knobby and undulatory rather than 

plane cleavage surfaces. Estimates of thickness based on width of outcrops of vertical 

beds indicate 200 to 600 feet. 

The Scarboro phyllite and Diamond Island 

slate are connected by rocks of intermediate 

and ·transitional lithologic type. In some 

sections both formations are present, the slate 

at the bottom; in other sections, in western 

Scarboro, Old Orchard, and Saco, the slate is 

absent. The phyllite is thus more widely 

distributed than the slate and may be regarded 

as overlapping on the Cape Elizabeth formation because of local failure of deposition of the · 

Diamond Island slate or a change from siliceous 

(Diamond Island) to argillaceous (Scarboro) 

sedimentation. 

Spurwinlc limestone.-The Spurwink limestone conformably overlies the Scarboro phyllite. It is named from Spurwink River, in 

Scarboro and Cape Elizabeth, Maine, whera it 

crops out. The formation is exposed in the 

eastern and southern parts of the Portland 

region but is probably also present under a 

heavy drift cover in the w:estern part. It is 

composed of thin in terlamina ted lenses of finegrained white and light-bluish crystalline limestone, fine-grained dark-gray calcareous mica 

schist, and fine gray siliceous mica phyllite. The 

layers· of pure limestone which preqominate in 

the lower and middle parts of the formation are 

f:r:om a small fraction of an inch to 2 or 3 inches 

'thick. The .gray phyllite bands of similar 

thickness are n1ore abundant in the higher 

than in -the lower parts and seem to dominate 

in the upper 50 feet. The formation is pyritiferous, in .places richly so. Weathering produces ribbed and rugose surfaces on the ledges 

and reddish .soils. Pefoimation has developed 

a characteristic intermingling of the fragments 

of disrupted limestone beds with the laminae 

of phyllite and' slate. The Spurwink limestone 

is about 200 feet_ thick. 

Jewell phyllite.-The Jewell phyllite conformably overlies the Spurwink limestone. It 

is named from Jewell Island, in Casco Bay, and 

is geographically coextensive with the Casco 

Bay group as mapped. The formation is an 

assemblage of .alternating gray and bluish to 

black fine-grained sericite phyllites in thin beds 

(a few inches to a few feet thick) containing 

also interbedded gray siliceous slate and very 

thin layers of quartzite. In some places the 

formation is dominantly light colored; in others 

it is dark, resembling the black-phase of the 

Scarboro phyllite. It is also like that for~ation in that its dark-colored parts ar.e in some 

places heavily impregnated with small grains 

and crystals of pyrite. However, the Jewell 

phyllite is distinguished qy the dominance o{ 

very fine grained medium-gray phyllite of silky 

luster and by the abundance in this rock of 

metacrysts, chiefly of garnet, but including 
172 ·. SHORTER CONTRIBUTIONS TO GENERAL · GEOLOGY, 1917. 

ottrelite, staurolite, magnetite, and other min- · but is not in visible contact with the Kittery 

erals, which commonly range from those of quartzite and -the Berwick gneiss. Farther 

minutely microscopic size to some measuring northeast the Jewell phyllite and Mackworth 

-an eighth of an inch. In some . places crystals slate are the areally marginal members of the 

of ottrelite and andalusite ( n an inch in length Casco Bay group and closely approach the 

are abundant. Berwick gneiss. The relation to the Berwick 

No relia~le measurement of the thickness of gneiss thus indicated is structural or strati- -

the Jewell phyllite is possible in view of the graphic · discordance (fault or overlap). By 

crumpling and repetition of the beds, but 500 correlation of the Cape Elizabeth formation 

feet seems more than ample to account for all with the Eliot slate the confo:..·mable superthe · outcrops, and the actual thickness may be position of the Casco Bay group on the Kitte~y 

much less 'than that. quartzite is indicated. This inference is supMackworth slate.-The Mackworth slate, -ported by the structure in the southwestern 

named from Mackworth Island, Casco Bay, part of the area occupied by the Casco Bay 

probably overlies the Jewell phyllite con- groJlp, where the rocks lie in a northeastwardformably. · It is the uppermost formation of pitching syncline and where the surrounding 

the Casco Bay group and is known only in and quartzite strikes east on the south side ar;d 

around the northern and northeastern parts of northeast on the northwest side of this syn- '--

of Casco Bay. The formation is composed of cline. The age of the Casco Bay group is 

quartzite and quartz-chlorite-mica slate in beds therefore Carboniferous. 

ranging from less than an inch to 2 or 3 feet in 

thickness. The rocks are dominantly siliceous 

and laminated and are characterized by abrupt 

alternations in lithologic character from flinty 

to chloritic slate. In color they range from 

white through drabs and light grays to dark 

grays and browns. Probably a thickness of 

100 fe~t is shown by the several exposures 

in and around Casco Bay. The top and 

whole thickness of the formation are unknown. 

Relations of the Oasco Bay group.-The metamorphism of the Casco Bay group is moderate 

and of the regional or dynamic type. It has 

resulted from the complex folding and intricate 

plication of its weaker -members. All its parts 

except the -nearly pure quartzitic beds are 

thoroughly . deformed, recrystailized, and 

foliate. -

In structure the Casco Bay-group is as a 

whole synclinal, _with a slight northeasterly 

pitch at the southwest end. I_n th~ longitude 

of Portland at least three secondary anticlines 

and two synclines are indicated, in which all 

. the formations are involved, and throughout 

the area there are many series of parallel minor 

folds that pitch northeast or southwest and 

involve one or several formations. 

- ·The area mapped as occupied by the Casco 

Bay group is bordered on the south and southwest by an area of Kittery quartzite and on the 

northwest by the Berwick gneiss. On the 

south and southwest the Cape Elizabeth format_ion, the lowest one of the group, approaches 

The Gonic formation, named.from the village 

of Gonic, N. :ij.; near which it is exposed, occu..: 

pies a so.:uthwesterly b~lt 2 to 6 miles wide and 

18 miles long from Sanford, Maine, to Barrington, N.H.· -This formation is made up ·of ar~naceous 

(graywacke) and argillaceous materials, metamorphosed to schist and phyllite, which are fo-r 

the most part rather thin bedded, fine grained, 

and whitish or light gray to dark gray. The 

rocks include mica schist and phyllite and interbedded fine to medium grained micaceous graywacke schists in beds as much as 2 feet thick; 

fine-grained light and dark gray -phyllites abundantly studded with dark staurolite crystals, 

some minute, others an inch or more long, or 

with red or brown garnets~ commonly in dodecahedrons about one-eighth to one-fourth inch in 

diameter, or with both minerals; and a little 

coarse muscovite schist·composed almost wholly 

of mica and very thin htminae of quartz. The 

beds of argillaceous origin that have developed 

into garnetiferous and staurolitic phyllites and 

mica-schist predominate, but the arenaceous 

beds (graywacke) are prominent. 

, The metamorphism of the formation is regional or dynamic and has progressed little furth~r and produced only slightly more general 

crystallinity than in the Casco Bay group. 

There is no evidence of significant contact 

metam?rphism, altho11:gh the granitie intrusive · 
STRATIGRAPHY IN SOUTHWESTER.N MAINE AND SOUTHEASTER.N NEW HAMPSHIRE. 17 3 

masses in the formation are large~ The de-

. velopmentof garnet and staurolite has no apparent relation to the granite. 

The beds of the Gonic formation are in general minutely crumpled, but folding on a large 

scale is not discernible. The strike is uniformly about northeast and the dip vertical or 

steep to the north west. · The thickness of the 

formation is unknown. About 100 to 150 feet 

of the coarser-grained phyllite and graywacke 

schist is shown in the hill northwest of Gonic 

village, and there may be two or three times as 

much in the rest of the formation. 

The Gonic formation is in contact on the 

southeast with the Berwick gneiss along a 

seemingly-straight line. The inferred relation, 

on the assumption of greater age of the -Berwick, is either fault contact or unconformable 

overlap. The northwest boundary of the belt 

of the Gonic formation, as drawn on the map, is 

a line between outcrops of rocks of dominantly 

Gonic type on the one side and of Rindgemere type on the'· other. The Gonic formation 

is intruded by biotite granite and pegmatite at 

both ends of the belt here considered. 

Discussion of the stratigraphic relations· and 

age of the Gonic formation follows the description of the Rindgemere and Towow formations. 

RINDGEMERE FORMATION. 

stone ·beds to dark bluish, gray, and black in 

the argillaceous beds. The rock varieties found 

in this region are light and dark gray micaceous 

slates and sericite phyllite associated with very 

fine grained micaceous graywacke schist, all 

abundari.tly speckled with small · to minute 

sporadic phenocryst-like minerals; :fine-grained 

gray ·sericite slate and phyllite which are pyritiferous and studded with chiastolite; interbanded light and dark gray and black carbonaceous quartz-sericite phyllites speckled with 

biotite flakes. and abundantly filled with large 

crystals of . chiastolite in the dark-gray and 

black bands; coarse mica schist. with chiastolite crystals measuring 6 to 8 inches by one-half 

to three-fourths of an inch; dark-gray ferrugi- _ 

no us chiastolite-bearing phyllite with which are 

interbedded dense quartzite and graywacke; 

and (in Acton and Shapleigh, Maine) some thin 

layers of white to bluish crystalline limestone. 

Andalusite artd chiastolite in large prismatic 

forms, in places with well-developed ''crosses," 

are abundant in ce;rtain -beds, notably in 

Rochester, 1! miles north of the center of the 

city, and in E.ast Rochester-, N.H., and on the· 

summit and upper east slope of Bauneg Beg 

Mountain in North Berwick, Maine. 

In the eentral part of the area occupied by 

the Rindgemere formation, and therefore, because of the structure, toward its top, the fine-: 

The Rindgemere formation is named from grained carbonaceous and argillitic sediments 

Rindgemere station (East Rochester), N. H., are the most abundant, although thin beds of 

on the Worcester, Nashua & Portland division quartzite and graywacke are present. At South 

of the Boston & Maine Railroad, at Salmon Lebanon, however, very near exposures of the 

Falls River. The formation is exposed in the Towow formation, · there ~s a zone of thincentral and northern parts of the Berwick quad- bedded light-gray slate and _quartzite. In the 

rangle in an area at least 12 miles wide and 15 outlying parts of the _area, as in the northeast 

- miles long. On the northeast it is cut off by corner of Rochester and the eastern part of 

granite and gneiss in Sanford and Acton, Maine, Lebanon, and therefore near the base of the 

and it extends southwest from Rochester, N.H., Rindgemere formation, quartzitic and grayfor an undetermined distance beyond the region wacke ·beds are dominant; but as a whole the 

examined. Within this area it surrounds a Rindgemere is made up dominantly of argilbelt 3 miles wide by 10 miles long occupied by laceous and somewhat carbonaceous rocks. 

the Towow form.ation, described below. The incomplete sections afforded by isolated 

The rocks of the Rindgemere formation are outcrops provide no basis for a measurement 

slate, phyllite, · and schist derived from some- of thickness. Several hundred feet is indicated 

what carbonaceous shale and argillite, with for each of the different · rock facies in East 

subordinate amounts of interbedded argilla-- Lebanon, East Rochester, and North Rochesceous quartzite, graywacke, and limestone. ter. The aggregate thickness of the formation 

They are generally thin bedded-few beds ex- is therefore considerable and may be about 

ceed ;2 -feet in thickness-and fine grained. 1,000 feet. 

The colors range from white and light gray or The data on the structure of the Rindgemere 

bluish in the quartzite, graywacke, and lime- formation in the Berwick quadrangle are 
174 SHORTER CONTRIBUTIONS TO GENERAL GEOLQGY, 1917 • . 

meager. T4e oqserved strikes are, in general, mation were seen near its contact with the 

northeast, with high northwest or vertical dip, Rindgemere .formation ~nd are therefore at the 

except between Rochester and West Lebanon, base ·of the Towow. ' The top of the Towow 

where . th~re. i~. an easterly strike .. and a lower formation is presumably· not present, and no · 

~ip, thus indic.ating ,a large major.syncline,in-: overlying formations are kn~Wn.. 

closing the elongate -oyal ,ar(:)a of the Towow There is no means of determining the thickformation. Another fold .of considerable. size ness of the part of the formation present in this 

is. suggested by the west-northwest strike arid region, b11:t it seems to be a few hundred feet. 

high northwest dip in East Lebanon, and many . The beds of tlie Towow formation are severely 

subordinate folds are shown by crumpling of crumpled, and the formation as a whole is probthe beds. Northwest dips in the hill 5_ nlj.l~~ ably intricately folded. Its relation to the · 

north of Rochester suggest that the · major Rindgemere formati()n indicates that the 

syncline may be overturned to the southeast. Towow formation here lies in the trough of a 

The Rindgemere formation surrounds the large syncline, whose east end is split by a $ecTowow forn1ationareally and is in contact with ondary anticline that pitches southwest . 

. the Gonic formation along an_ approximately 

straight northea.."t line on the southeast. The 

northern, northeastern, and northwestern limits of the Rindgemere have not been determined, because in those directions numerous 

1 masses of granite and pegmatits have disrupted 

an~ extremely metamorphosed . the sediments, 

so that their delineation is not yet possible-. 

Besides these intrusives on the border of the 

mapped area of the Rindgemere formation there 

are gra~i~i~ intrusives in North Berwick, Ma!ne, 

and in Rochest_or, N. H. .. · 

Discussion of the strf}tigraphic relations and 

age of the Rindgemere formation follows the 

description of the Towow formation. 

TOWOW FORMATION. 

The name of the Towow forrnation is derived 

from the original name of the first settlement 

in. the town of Lebanon, :Maine. The formation has been found only within that town, 

where it occupies a northeasterly belt about 

10 miles long and 2 to 3 n1iles wide. It is cmnpQsed of unifoirnly very fine grained and thinbe<Jded dark-gray to black carbonaceous or 

graphitic siliceous slates and s~ricitic slate or 

phyllite~ Except for some light-gray siliceou~ 

sericitic slate in North Lebanon and South Lebanon ~p.d for some interbedded layers of lightgray quartzite afew inches thick in South Lebanon, the fornlat,ion is rich)y carbonac;e~~ms and 

in places graphitic and is in1pregnated with 

-. pyrite in sn1all individual crystals and lenticular masses. These rocks are lithologically 

identical with the Diamond Island slate and 

the black pyritiferous part of the Scarboro 

phyllite of the Casco Bay group. The lightgray and quartzitic phases of the Towow forSTRATIGRAPHIC RELATIONS .A'ND .AGE OF THE GONIC, 

RINDGEKERE, AND TOWOW FORKATIONS. 

The Towow formation is surrounded by the 

Rindgemere formation, which occupies the area 

between the T()wow and Gonic form~tions. 

Between these .three formations there are intermediate or transitional phases, and all three 

show a general lithologic · similarity in bejng 

dominantly fine grained and thin bed.ded and 

containing .an abundance of argillaceous :qtaterial. They are, furthermore, allied by · a content of fine carbonaceous-matter, inconspicuous in the Gonic formation but increasing to 

abundance in the Rindgemere formation and 

to dominance in the Towow formation. They 

are ! structurally conformable and show no _ 

di~erences in aegree of metamorphism between beds of similar character. For these 

reasons and, furthermore, because there are no 

da~a to indicate the'contrary, they are assumed 

to form a stratigraphically conformable succession, of which the Gonic, on the basis of the . 

structural data present, is the lowest and the 

To.wow the highest. · 

These formations are assigned to the Carboniferous .period and are approximately equivalent to the lower formations of the Casco Bay 

group-the Cape Elizabeth, · Diamond Island; 

and Scarboro-and so also to the Eliot slate 

and to the Carboniferous Worcester phyllite 

in the Worcester Basin, Massachusetts~ This 

correlation rests on the following considerations: 

(1) The Towow formation and the J?iamond. 

Island slate are of identical character. (2) The 

three groups correspond closely in lithologic 

facies---that is, all three contain basal thin 

interbanded gray arenaceous (graywackf) and 
• 

. . 

STRATIGRAPHY IN SOUTHWESTERN MAINE ' AND SOUTHEASTRRN NEW HAMPSHIRE. f7 5 

a:r:gillaceous beds with abundant black carbonaceous laminae, succeeded by incr~asingly argillaceous beds, which in turn are followed by 

black carbonaceous arid pyritiferous siliceous 

slates and sericite phyllite . . Furthermore, the 

data on the thickness of the several members and 

formations, though not sufficient to · establish 

close resemblance, nevertheless indicate coniparable thicknesses 'or at least measurements 

compatible with the argument for correlation. 

Thus the maximum aggregate thicknesses of 

the formations compared are about 1,300 and 

1,800 feet, of both of wh.ich the far larger parts 

are in the lower arenaceous and gray argillaceous members and much smaller parts in the 

black carbonaceous slates. (3) Similarity in 

structure and in type and degree of metamorphism indicate identical history for both. (4) 

In lithology, deformation, and metamorphism 

these formations are similar to a formation of 

Carboniferous age (Worcester phyllite) in the 

Worcester Basin, described by Emerson. 1 Mr. 

Keith and Mr. LaForge 2 report that these 

formations of the Worcester Basin extend 

northeastward into New Hampshire within 30 

miles of Rochester, in a belt trending approximately toward the area of the equivalent Eliot 

slate. They are on the northwest side of a 

belt of graywacke and other gneisses that Mr. 

LaForge 2 reports to ·be, in part at least, continuous with and equivalent to the Berwick 

graywacke gneiss, which is in similar relation 

to the Gonic formation. 

IGNEOUS ROCKS. 

The relations of the igneous rocks of this 

region to the surrounding sediments have been 

determined so far as opportunity for field o bservation permitted. Very few of the igneous 

rocks have yet been studied petrographically. 

The following statements are made merely to 

point out _the areal distribution of the larger 

associated groups of igneous rocks and. to indicate roughly their stratigraphic relations. 

Westbrook granite and Falmouth pegmatite.-

In West brook, Falmouth, ·and Portland, Maine, 

granite and pegmatite intrude the Berwick 

gneiss and, so far as is known, are restricted 

to the northeast part of the gneiss belt. These 

1 Emerson, B. K., Geology of Massachusetts and Rhode "island: U. S. 

Geol. Survey Bull. 597 (in press). · 

2 Personal communications . 

rocks are named the Westbrook granite and 

Falniouth pegmatite, after the towns in which 

they are well developed and exposed. 

The West brook granite protrudes through 

the Berwick gneiss in a number of bodies 

elongated in northeaSterly and northerly 

directions and ranging in size from those 

that are very small to some 5 miles or more 

long and 2 or 3 miles wide. · It is a gneissoid 

granite of medium-gray color and fine, even 

texture and contain!' conspicuous crystals of 

biotite. Its essential components are microcline or orthoclase, quartz, oligoclase, and 

biotite, named in the order of abundance. 

Some very small masses of gneissoid granodiorite and diorite are included with the Westbrook granite. 

The Falmouth pegmatite occurs as . dikes' 

ranging from about an inch to many hundred 

feet in thickness and from a few feet to 3 or 4 

miloo in length. They are generally parallel to 

the northeasterly trend of the gneiss, although 

some of the smaller dikes transect or irregularly 

invade the gneiss they intrude. The Falmouth 

is a normal medium to very coarse grained 

pegmatite composed of perthitic microcline, 

quartz, muscovite, and albite, in places carrying 

abundant crystals of black tourmaline and red 

garnet. With it is associated a fine~grained 

white or light-gray garnetiferous apliter The 

pegmatite and aplite in many places have diffuse 

contacts with each other and with the Westbrook granite, indicating transition or intimate 

relation between them, although theW est brook 

granite is cut by the pegmatite and aplite and 

is very evidently somewhat older. Some of 

the larger pegmatite dikes in Falmouth have 

been slightly crushed. 

The age of the West brook granite and Falmouth pegmatite is. post-Berwick and presumably pre-Carboniferous, because they are not , 

known to intrude the . near-by rocks of the 

Casco Bay group. 

Igneous rocks of the Algonkian ( ?) complex.-

An assemblage of igneous roc~ restricted in 

distribution to' the area of the Algonkian ( n 

complex includes chiefly several varieties of 

fine to medium grained, evenly granular and 

porphyritic pink or buff-colored muscovite 

granites which are generally free of or deficient 

in biotite. They are very commonly gneissoid 
176 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1911. 

in texture. The series also includes fine- referred to the Maokworth slate. The visible 

grained dark-gray diorite, a gneissoid coarse contacts are so badly mashed and recrysta1-

porphyritic biotite granite (augen gneiss), and lized that the intrusive nature there indicated 

a very coarse white feldspar-quartz-muscovite is not decisively shown. This· nature is, howpegmatite which in places contains black tour- ever, further indicated by transgression of·the 

maline and some of which is crushed. · The bedding of the formations and by the aplite-

-small masses of granitic rocks and the pegma- like border facies. · The Cushing granodiorite, 

tites very closely parallel the trend of the sedi- though yolinger than the Carboniferous Casco 

mentary bands and are injected along the Bay group, is not improbably late Carbonifcleavage. Larger m:;tSses are ·elongate and erous, because it is older than undeformed 

have the same or approximately the same post-Carboniferous granite, which in: turn is 

trend, as the result of injection along the beds older than supposed Triassic. dikes. · (See 

or of infolding with them, or probably hoth. below.) 

Except that they are presumably pre- Altered ba..~ic dikes.-A considerable number 

Carboniferous, because they do not invade _of small black and dark-green dikes of basic 

the Kittery quartzite, the age of these intru- rocks (all less than 10 feet wide) are abundant 

sives has not been deterniined. However, a in _ the rocks of the ·casco Bay gro.up and the 

small body of white or buff fine-grained mus- Cushing granodio1_:ite. They are now severely 

covite granite and aplite that intrudes the altered schistose biotite-hornblende and hornKittery quartzite at Brave ·Boat Harbor, blende-garnet rocks. They may be c!osely 

though not deformed, is otherwise not unlike related in age to the Cushing granodiorite. 

some of the fine muscovite granites in Rye . Diorite in Saco.-The diorite in Saco, Maine, 

and New Castle. This rook at Brave Boat is an irregular elliptical body about 3 milesHarbor makes .the assignment of the similar long and 1! miles wide. The rock is medium 

rocks in Rye and New Castle doubtful. to dark gray, moderately coarse grained, and in _ 

Gushing granodiorite.-The Cushing grano- some places massive, in others gneissoid; it is 

diorite, named from Cushing Island, in Casco composed essentially of orthocla~e (~),andesine, 

Ba.y, occupies a single northeasterly belt hornblende, biotite, and subordinate amounts of 

extending for 16 miles from Scarboro, Maine, · quartz. This ro_ck invades the Berwick gneiss 

across Casco Bay to the northern lin1it of the and the Kittery quartzite and is therefore 

region here discussed. It is narrow at its post-Carboniferous. An argillaceous quartzite 

ends and has a maximum width of about 3! in contact wit~ the diorite is slightly altered 

miles. The granodiorite is thoroughly gneiss- to a rock somewhat like hornfels. 

oid, of light ,to dark gray color, and for the Exeter diorite.--The Exeter diorite, in Exeter,. 

most part finely and evenly but only slightly Newmarket, Durham, Madbury, Dover, and 

porphyritic in texture. Its principal com- Rollinsford, N~ II., occupies an area 15 miles 

ponents are albite-oligoclase as phenocrysts long and from half a mile to 5 miles wide. 

and quartz, feld~par, biotite, and hornblende The small area of diorite in Greenland_, N~ H., 

in the groundmass. Muscovite · or sericite, is a similar, and probably related rock. The 

probably all of secondary origin, is abundant, rock is a generally even, medium-grained iight 

but in proportions - differing from place -to to medium gray hornblende-bjotite diorite or 

place. Along part of the northwest · border quartz diorite, which changes in composition 

there is a white aplite-like facies. In places considerably but gradually fron1 place to place. 

toward the southwest end of the belt the In Newmarket, N. H., both aplitic and basic . 

granodiorite is dark gray, very biotitio, and vari~ties are present. These dioritic rocks are 

richer in hornblende ,than elsewhere. At the intrusive in the Kittery quartzite and Eliot 

northeast end it is very light gray and deficient slate and are therefore post-Carboniferous. · 

in biotite.· Biddeford granite.~The Biddeford ·granite, 

The Cushing granodiorite is infolded in and -in Biddeford, Kennebunkport, Kemi.ebunk, 

deformed with the . rocks of the Casco Bay and Dayton, Maine; is a generally even or 

group. It is known to be in contact chiefly slightly · porphyritic medium-grained biotite 

with the Cape Elizabeth formation but also granite of light-gray or 'pinkish-buff color, 

with the Jewell phyllite and rocks doubtfully composed of white microcline or orthoclase, 
STRATIGRAPHY IN ~OUTHWESTERN MAINE ANI) SOUTHEASTERN NEW HAMPSHIRE. 177 

quartz, oligoclase, biotite, and in some places 

also a little 1nuscovite. A few very small 

dikes of pegmatite and aplite are associated 

with it. The rock is intrusive in the Kittery 

quartzite and is post-Carboniferous. 

Other granites.-The granitic mass in Wells, 

York, South Berwick, and Eliot, Maine, is an 

assemblage, including chiefly a granite of the 

Biddeford type and several more mafic 

varieties, probably differentiates, among which 

are the gaboros of Cape Neddick and South 

Berwick. These rocks are intrusive into the 

Kittery quartzite and are of post-Carboniferous 

age. 

The granite in Rochester, Dover, and Barrington is generally a fine or medium and evengrained · but in places somewhat porphyritic 

and moderately coarse grained biotite-muscovite granite containing orthoclase and plagioclase and in places garnetiferous. In it a:re 

abundant large bodies of coarse pegmatite, COJfsisting of microcline, quartz, muscovite, and 

albite. 

In North Berwick, Maine, there is a small 

body· of very fine grained muscovite-biotite 

gTanite surrounded by and probably intrusive 

into the Rindgemere formation. It is, therefore, probably post-Carboniferous. 

The large area of granitic · rocks in Lyman, 

Alfred, Sanford, and Shapleigh, Maine, contains 

many included patches of gneiss (metamorphosed sediments) · and a variety of granites, 

the most conspicuous of which are large 1p.asses 

of granite of the Biddeford type; some quartz 

diorite, composed of oligoclase, biotite, quartz, 

dark hornblende, and magnetite; and somewhat gneissoid coarse-grained biotite-musco- · 

vite granite, with which is associated abundant 

coarse pegmatite. These rocks are intrusive 

in the Berwickgneiss and the Gonic and Rindgemere formations and are post-Carboniferous. 

The assemblage may include also some older 

but as. yet unrecognized granitic rocks. 

The areas of granitic rocks in Milton, N. H., 

and Acton and Lebanon, Maine, shown on the 

map, are occupied chiefly by medium to coarse 

grained gneissoid muscovite-biotite granites 

and coarse pegmatite. Included with these 

are various other granitic rocks and many 

patches of metamorphosed sediments. 

Trap dikes.-Throughout this region there 

are large numbers of small to moderately large 

trap dikes, for the most part of fine-textured 

gabbroic, diabasi:c, or doleritic habit. A few of 

the larger dikes are coarse grained, and many 

are in part glassy. They have been observed 

in all the other rocks of the region and many are 

themselves cut by others. ·Most if not all of 

them are younger than the post-Carboniferous 

·granitic intrusives and are tentatively correlated with the Triassic eruptions of Nova 

Scotia and southwestern New England. 

0 
DEPARTMENT OF THE INTERIOR 

FRANKLIN K. LANE, Secretary . 

-UNITED STATES GEOLOGICAL SURVEY 

GEORGE OTIS SMITH, Director 

Professional Paper 108-J 

THE FLAXVILLE GRAVEL AND ·ITS RELATION TO 

OTHER TERRACE GRAVELS OF THE 

NORTHERN GREAT PLAINS 

BY 

ARTHUR J. COLLIER 

AND 

W. T. THOM, JR. 

Published January 26,1918 

Shorter contributions to general geology, 1917 

( Paates 179-184 ) 

WASHINGTON 

GOVERNMENT PRINTING OFFICE 

1918 
CONTENTS. 

Introduction ............... ~ ... ~ ........... , ........... . .......... ~ ......................... ~ .... -.-----

Flaxville gravel ...................................................................... · .. . ............ · .... . 

Late Pliocene or early Pleistocene gravel. ..................................... . ..... . .. . .................• -

Late Pleistocene and Recent erosion and deposition ........................ . ..... . ..... .... ... ~ ............ . 

Oligocene beds in Cypress Hilla .................... .' ................. . ........................ . .......... . 

Summary ....•......................... ················· · ·· · ········· .············· ··" ···················· 

ILL USTRA 'fl ONS. 

PLATE LXII. Map of northeastern Montana and adjacent parts of Canada, showing the distribution of erosion 

Page. 

179 

179 

182 

182 

183 

183 

Page. 

levels and gravel horizons................................................................ 180 

J,XIII. A, Surface of the Flaxville plateau, northeastern Montana; B, Outcrop of cemented Flaxville 

gravel in escarpment ·of plateau northwest of Opheim, Mont.; C; Escarpment of the Flaxville 

plateau, northeastern Montana, showing outcrops of cemented sand and the thickness of the 

Flaxville gravel .................. ~ .......... ·.........•.................................. 182 

LXIV. A, Cemented gravel-interstratified with cemented sand 9 miles northeast of Scobey, Mont.; B, 

Cross-bedding of Flaxville gravel 5 miles west of West Fork post office, Mont................. 182 

LXV. A, Railway cut west of Flaxville, Mont.; B, Escarpment surrounding the late Pliocene or 

early Pleistocene bench in Milk River valley, Mont.; C, Vandalia dam, Mi.lk River, Mont., 

showing the escarpment surrounding the late Pliocene or-early Pleistocene bench............ 183 

FIGURE 27. Diagrammatic section showing the relative altitudes of the four erosion levels represented in northeastern Montana and the adjacent part of Canada.............................................. 184 

II 

i, 

'!· 
THE FLAXVILLE GRAVEL AND ITS RELATION TO OTHER TERRACE 

GRAVELS OF THE NORTHERN GREAT PLAINS. 

By ARTHUR J. CoLLIER and W. T. THoM, Jr. 

INTRODUCTION •

1 

In Nebraska and South Dakota there are 

widespread deposits of · gravel and other· 

material, largely surficial and generally unindurated, known as the White River, Arikaree, 

Ogalalla, and other formations, 2 which range 

in age from Oligocene to Pleistocene. West of 

these deposits, on the flanks of the Rocky 

Mountains, are several high piateaus covered 

with gravel, whose age, though not known, is 

generally regarded as Pleistocene. At some 

places the position of this gravel indicates its 

continuity with the Tertiary formations farther 

east, but their equivalency has not been proved. 

It is the purpose of this paper to outline the 

e'vidence obtained by. the writers in 1915 and 

1916 regarding the age of the gravel found on 

two high terraces in the northern part of the 

Great Plains ·and t.o show its relation to a 

still higher gravel, known to be of White 

River age, discovered by Canadian geologists 

some years ago. Messrs. R. F. Baker, E. T. 

Conant, and H. R. Bennett were enthusiastic 

coworkers in collecting this evidence, and to 

them much of the credit is due. 

The area described, as shown in Plate LXII, 

extends along the south side of the international boundary from Redstone, about 30 

miles west of the Montana-North Dakota line, 

w~stward to the west side of Boundary Plateau/ 

a distance of 175 miles. It continues northwestward from the plateau far enough to take 

in the whole of the Cypress Hills, where Canadian geologists have discovered deposits of 

·White River (Oligocene) age. 

1 An abstract of this paper has been published by the Washington 

Academy of Science. 

2 Osborn, H. F., Cenozoic mamJl!,al horizons of western North America: 

U. S. Geol. Survey Bull. 361, p. 65, fig. 10, 1909. 

s The name Boundary Plateau was used by McConnell to designate 

the northern extension of what is called Cherry Ridge on the American 

side. It is retained in this paper for convenience. 

103977°-18 

FLAXVILLE GRAVEL. 

The Flaxville gravel, named from the town 

of Flaxville, on the Scobey branch of the Great 

Northern Railway, was deposited in Miocene 

or early · Pliocene time. The history of · its 

discovery is as follows: 

During the field seasons of 1915 and 1916, 

in the course of an investigation of the lignite 

resources. of northeastern Montana, the writers 

found some "extensive plateaus that are so 

deeply buried beneath a cap of gravel and 

kindred materials as to make the location of 

lignite outcrops impossible. This gravel has 

been described by several writers under the 

names ''glacial overwash, '' ''quartzite gravel,'' 

etc. Bauer 4 had recognized the possible significance of this terrane and had provisionally 

referred it to 'the Oligocene of the Cypress 

Hills.5 

On the third day in the field the senior 

writer inquired of Atle Taerum, the proprietor 

of the store at Avondale, whether in digging 

his well he had seen any signs of lignite. 

.Being answered in the negative, the writer 

made a personal examination of the well and 

found on the dump some fragments of bone 

said to have been found in sand at a depth of 

30 or 40 feet. From this beginning as close 

an inspection as the circumstances would 

permit was made of wells and other natural 

and artificial exposures of the gravel by members of the Geological Survey party. In many 

places fragments of fossil bones had been 

found but not preserved, as their significance 

was not appreciated. D. H. Linton, Hagen 

Hayenga (postmaster at West Fork), L. T. 

Greenup, Martin Presnell,. Warren Redfield, 

4 Bauer, c." M., Lignite in the vicinity of Plentywood and Scobey, 

Sheridan County, Mont.: U.S. Geol. Survey Bull. 541, p. 301, 1912. 

~ Cope, E. D., Species from the Oligocene or lower Miocene beds of the 

Cypress Hills: Canada Geol. Survey Contr. Canadian Paleontology, 1891. 

179 
180 SHORTER CONTRIBUTIONS T:O GENERAL GEOLOGY, 1917. 

J. A. Stewart, Herman Forbregd, and Prof. 

L. 0. Swenson contributed specin1ens . . 

As a result of · the search, fragments of 

foE?sil bones have been collected from 25 widely 

distributed localities. · These fragments were 

submitted to Dr. J. W. Gidley, of the United 

States National Museum, who identified them 

as representing various forms of the three-toed 

horse (protohippid, Protohippus; Neohipparion, 

and Merychippus), horned gopher (mylagaulid), rabbit (Lepus), rhinoceros (Teleoceras), 

oreodont (Merycodus), camel (ProcameZ.us, 

camelid, and Gamelops), saber-tooth tiger . 

(machaerodont), doglike animal (amphicyonid), 

and fish. His full report follows: 

F.l. SE. ! .sec. 26, T. 34 N., R. 42 E., Atle Taerum's 

well at Avondale: 

Protoh:i,ppid (astragalus). 

F. 2. Near north side of SW.! sec. 27, T. 34 N., R. 42 E., 

excavation on land of D. H. Linton, Avondale: 

Protohi ppid (distal end ofradi us). 

?Mylagaulid (proximal half of humerus). 

Lagomorph cf. ?Lepus (fragment of maxillary and 

toe bone). 

F. 4. 300 feet southwest of northwest corner sec. 5, T. 35 

N., R. 45 E. 

Proto hi ppid (astragalus). 

? Procamel'us sp. (phalanx). 

F. 5. SW. l NW. l s.ec. 24, T. 34 N., R. 44 E., Hagen 

Hayenga's well: . 

Neohipparion sp. (part of upper cheek tooth). 

Procamelus sp. (distal end of meta podia!). 

F. 6. Near West Fork post office, T . 34 N., R. 44 E.: 

? Neohipparion sp. (upper cheek tooth of left side). 

F. 7. NW; t SW. t sec. 25, T. 34 N., R. 44 E.: 

Protohippid (fragments). 

F. 11. NE.l sec. 31, T. 36 N ., R. 45 E., "from gravel and 

sand resting on top of Fort Union bluff." 

Protohippid cf. Neohipparion ~p. (astragalus, portion 

of upper molar, and fragments). 

Camelid d. Procamelus sp. (astragalus, piece of toe 

bone, and fragments). 

F.. 13. SW. l sec. 13, T. 34 N ., R. 45 E., slope of TaylorGreen prospect: 

Camelid cf. Procamelus sp. (distal end of phalanx). 

F. 14. Near east -quarter corner of sec. 6, T. 34. N ., R. 

47 E., from well at depth of 28 fee.t: 

?Camelid (lumbar.vertebral centrum). 

F. 15. NE.l sec. 33, T. 35 N., R. 47 E.: 

Mylagaulid (lower molar). · 

F. 19. Sec. 20, T. 36 N. , R. 45 E.: 

· Protohippid (fragment of upper molar). 

. ?Procam~lus sp. (phalanx and astragalus). 

F. 20. Sec. 15, T. 37 N., R. 44 E.: . 

I . Protohippid (ge~us and species not determined). 

F .' 21. SW. t sec. 7, T. 36 N,, R. 44 E.:· 

Merycodus sp. (fragment of a left lower jaw containing four deciduous premolars). 

F. 22. Near center ofT. 35 N. , R. 41 E.: 

Neohipparion sp. 

F. 23. Sec. 12, T. 35 N. , R. 41 E., J. A. Stewart's well: 

Protohippid. 

F. 26. Sec. 32, T. 36 N., R. 49 E.: 

Protohippid (end of metapodial, ftagment of lower 

molar). 

F. 27. C.ut of Great Northern Railway a mile west of 

Flaxville station: 

?Teleoceras sp. or ?Aphelops (toe bone and fragments). 

?Procamelus sp. (tooth and toe-bone fragments). 

Protohippid, probably Neohipparion sp. (fragment 

of lower jaw containing teeth, three parts of teeth, 

astragalus, and fragments). 

F; 28. Just south of quarter corner between sees. 28 and 

29, T. 35 N., R. 50 E.: . 

· Protohippus sp. (fragments of teeth). 

Carnivore (?amphicyonid) (fragment of left maxillary containing fangs and alveoli). 

F. 29. T. 35 N., R. 50 E., first cut of Great Northern 

Railway west of Flaxville. 

Neohippar,ion ?affine or n. sp. (upper molar and lower 

molar possibly belonging to same speciei>). 

Neohipparion sp. (lower molar). 

Procamelus sp. (fragmentary foot bones and teeth). 

?Camelops sp. (large tooth, last right lower molar, 

wrapped in mud ball). Apparently Pleistocene 

species. 

Machaerodont, genus and species nqt determined 

(metapodial). 

Fish, not determined (lower jaw). 

F. 31. Sec. 33, T. 36 N., R. 50 E. , 2 miles north of Flaxville: · 

Camelid cf. Procamelus sp. (portion of posterior 

molar or left lower jaw). 

F. 33. In railroad cut a mile west of Flaxville: 

Protohippid (fragm.ents of jaw, toe, and limb bones). 

Artiodactyl, probably Merycodus (single phalanx). 

F. 34. Cut of Gre~t Northern Railway a mile west of Flaxville: 

Mylagaulid cf. Ceratagaulus sp. (large cheek tooth). 

Protohippid cf. Neohipparion niobrarensis (right 

upper molar). 

Protohippid ? Neohipparion sp. (fragments of three 

upper teeth). 

F. 35. Railroad cut a mile west of Flaxville: 

?Procamelus sp. (part ofulna, much broken). 

F. 36. Southeastern part ofT. 33 N ., R. 43 E., collected by 

W. C. Alden: · 

· Merychippus sp. (toe bone and fragment of jaw). 

Certainly one of the Miocene three-toed horses; 

probably upper Miocene. 

F. 37. Sec. 23, T. 36 N., R. 23 E., Prof. Swenson's well: 

?Protohippus, fragments of fossil mammals, one 

piece recognizable as fragment of upper molar 

of one of the Miocene h0rses. 

F. 38. Sec. 24, T. 36 N., R. 23 E., Louis Hoff's well: 

? Protohippus, fragments of manun:alian remains; 

among them portion of an upper molar of one of 

the Miocene horses. 
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. THE FLAXVILLE GRAVEL OF THE NORTHERN GREAT PLAINS. 181 

Mr. Gidley further remarks: 

None of the material is sufficiently good or complete to 

make positive specific determinations, and it is therefore 

of no value as indicating horizon, except in a broad way. 

With the exception of the specimen reported as Pleistocene 

all the material appears to belong to the upper Mipcene. 

It can be stated positively, I think, that with the exception noted, the beds from which these fragments were collected can not be older than Miocene or younger than 

lower Pliocene. 

The formation from which these fossils were 

collected caps a series of even-topped plateaus 

ranging in altitude from about 2,600 feet at its 

east end, a few miles south of Redstone, to . 

3,200 feet in the west _front of the Boundary 

Plateau in the Cherry Creek quadrangle. It is 

from a few feet to 100 feet thick and rests upon 

the eroded surfaces of the Fort Union, Lance, 

and Bearpaw formations. A characteristic 

view of the plateau surface is given in Plate 

LXIII, A. In the opinion of the writers this 

plateau represents an erosional level developed 

during a period . subsequent to the Oligocene 

as represented in the Cypress Hills, and the 

fossil-bearing formation must have been deposited in Miocene or early Pliocene time. It 

seems hardly possible that these fossils could 

have been eroded and redeposited over so wide 

an area in -the Pleistocene epoch, especially 

as no source from which they could have come 

has been recognized. Moreover, there seems 

to be no intermingling of Pleistocene fossils 

with the ·Miocene. 

The distribution of the Flaxville gravel is 

shown on the accompanying map (Pl. LXII). 

It is generally composed of yellowish to ashgray gravel, clay, and sand, but in some places 

it contains beds of white marl and volcanic ash. 

The gravel consists of well-rounded pebbles 

from less than an inch to a foot or more in diameter, of quartzite and argillite derived from 

the Rocky Mountains. Limestone pebbles 

from the same source may have been dissolved 

and the lime redeposited as cementing material 

and beds of marl. The materials composing 

the Flaxville gravel are mostly noncoherent and 

are excavated easily by well diggers, though 

beds of hard sandstone and conglomerate cemented with calcite from 1 foot to several feet 

thick are encountered in most of the wells. In 

places the formation is very thoroughly cemented with calcite and forms prominently 

outcropping ledges of sandstone and conglomerate, as shown in Plate LXIII, B and C. 

Many such outcrops present a great deal of 

cross-bedding and 'are not continuous over · 

large areas. 

In ~he railway cuts west of Flaxville (see 

Pl. LXV, A), where the best collection of fossils was made, about half the material exposed 

is gravel _and the remainder clay and sand; 

about 1 foot of marl or concretionary calcite is 

also present. The bedding is very irregular, as 

might be expected of deposits on the flood 

plain of a river. North of Flaxville the road 

to Whitetail crosses a considerable thickness of 

gravel. Ten miles southeast of Flaxville, in · 

the escarpment at the edge of a plateau, the focmation consists of about 35 feet of cemented 

sand and gravel overlain by uncemented sand. 

Northeast of Scobey about 55 feet of more 

or less cemented sand and gravel is overlain 

by· 25 feet of uncemented gravel and soil. 

Plate LXIV, A, shows a bed of gravel interstratified with sand. The following section of 

a well southwest of Scobey was given by Martm 

Presnell, the owner: 

Section of a well southwest of Scobey, Mont., in sec. 33, T. 35 

N. , R. 47 E. 

Ft. in. 

GraveL .......... ... --. . . . . . . . . . . . . . . . . . . . . . . . . . . 6 0 

Clay ... .. ......... -............................... 52 0 

Lignite slack.... . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . 6 

Clay ........................................... ·. 2· 0 

Lignite slack..... . ........... . .. .. ............... 1 0 

Gravel and bones; water. 

61 6 

In a well 2 miles southwest of the Presnell 

well 28 feet of coarse gravel, carrying bones, 

was found. About 20 miles west of Scobey 

there are several good exposures of the lower 20 

feet of the formation, together with the underlying Fort Union. The gravel is uncemented _ 

and in"terstratified with cemented sand, and the 

surface is strewn with loose gravel containing 

bone fragments. A very striking exposure of 

the fo~mation occurs 5 miles west of West Fork 

post office, south of Hell Coulee, in sec. 30, T. 

34 N., R. 44 E., where ltbout 30 feet of hard 

sandstone showing very marked cross-bedding 

caps the edge of the plateau. This feature is 

shown in Plate LXIV, B. The sandstone probably rests on gravel, for an exposure of uncemented gravel was found near the bottom of 

the coulee. In sees. 19, 20, and 29, T. 35 N., 

R. 43 E., 8 miles nor~heast of Avondale, south 
182 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, l917. 

of Dawson Coulee, a slightly different phase is 

presented, as shown by the following generalized section: 

Generalized section of Flaxville gravel in sees. 19, 20, and 29, 

T. 35 N., R. 43 E. 

[Thicknesses approximate.] 

Feet. 

Marl, containing a few scattered quartzite pebbles.... 15 

Sandstone cemented with calcite ......... __ .___ __ . . _ 30 

Volcanic ash, white to yellow, very pure but mixed 

with the underlying gravel at the base. _ . ___ ... _ . 15 

Gravel, more or less cemented._ ......... _._. ___ .. _._ 20 

Fort Union formation. 

80 

The marl (an impure soft white limestone) 

was either deposited by water flowing over the 

surface into a shaJlow pond or gathered from_ 

the underlying beds and brought to its present 

position by percolating waters. Similar occurrences are indicated by fragments of marl in 

the soil of the townships to the west and nor.th. 

This is the only locality where pure volcanic 

ash has been recognized, though similar material mixed with sand has been noted about 12 

miles to the northeast. The gravel is very 

coarse, and well-rounded pebbles at least a 

foot in diameter, which must have been derived from it, were noted on the surface a short 

distance away in Daw$on Coulee. 

On Boundary Plateau in the vicinity of 

Cherry Ridge 74 feet of sandy gravel overlies 

8feet of cemented sandstone in a well in sec. 10, 

T. 36 N., R. 23 E., south of which two other 

wells of somewhat less depth have yielded 

fragments of fossil bone. The eastern . edge 

of the formation is exposed in Tps. 35 and 36 

N., R. 27 E.~ where it is dissected by Woody 

Island Coulee; the western edge of the formation along the west escarpment of the Boundary Plateau has been mapped by Stebinger 

in Tps. 35, 36, and 37 N., ~. 21 E., where it 

consists of cemented sand, gravel, and marl. 

LATE PLIOCENE OR EARLY PLEISTOCENE 

GRAVEL. 

Below the Flaxville level there are extensive 

areas varying in altit1lde from 2,500 to 2,800 

feet on which the bedrock is exposed or can be 

found in wells at no :very great depth. The 

relative altitudes of this bedrock surface are 

indicated on _the maps prepared but not yet 

published by (he International ·Boundary 

Commission. In the ~ vicinity of Redstone it 

is a well-marked plateau or bench ranging in 

altitude from 2,400 to 2,500 feet. · This feature 

extends westward near the international boundary to Scobey (altitude 2,450 feet), at the 

forks of Poplar River. 

Between Opheim and the Boundary Plateau 

the same period of erosion is represented by a 

gn~at expanse of highly dissected country 

incl~ding level-topped areas, sloping grasscovered hills, and badlands on which the Bearpaw shale is exposed, ranging in altitude from 

2,500 feet nea~ Milk River to 3,000 feet at the 

international boundary near the crossing of 

Frenchman Creek. Small bodies of ~tratified 

gravel and silt have been noted in sec. 3, T. 36 

N., R. 52 E;·, east of Daleview; in several wells 

in the neighborho'od of Julian; west of Opheim, in sec. 13, T: 37 N., R. 39 E., and west 

of Baylor,. in sec. 25~ T. 35 N., R. 38 E. The 

best exposures seen are in sec. 23, T. 33 N., 

R. 30 E., north of Malta, a few miles from Milk 

River, where about 25 feet of interstratified 

gravel and yellowish silt caps the edge of the 

bench at an altitude of about 2,500 feet above 

the sea, . or 300 feet above· Milk River. The 

gravel is cemented, presumably with calcite, 

forming a conglomerate that crops out in the 

form of a small cliff. Fragments of bone and a 

single toothwere obtained from the face of the 

cliff. Dr. Gidley identified the tooth as that 

of a horse ·resembling the living species and 

states that it can not be so old as the Flaxville 

fauna. The formation here _ rests upon the 

Judith River formation, but about 5 miles east 

of this locality it rests upon the Claggett shale 

and consists of .about 25 feet of yellowish silt 

containing two beds of gravel, one at its hase 

and ·another 15 feet higher. The g~avel is comparatively fine, the pebbles being less than an 

inch in diameter. In the light of the evidence 

now at hand this formation i~ regarded as of 

late Pliocene or early Pleistocene age. The 

erosion of the very extensive areas below the 

Flaxville level must have been accomplished 

during middle Pli?cene time. 

LATE PLEISTOCENE AND RECENT EROSION AND 

. DEPOSITION. 

The streams of the · region have eroded' their 

valleys from 100 to 500 feet below· the level 

assigned to the late Pliocene or early Pleistocene. Milk River now occupies a valley 1 to 

5 miles wide eroded by Missouri River before 

the last great invasion of ice in the glacial 
Ua S, GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE LXIII 

.A. SURFACE OF THE FLAXVILLE PLATEAU, NORTHEASTERN 

MONTANA. 

B. OUTCROP OF CEMENTED FLAXVILLE GRAVEL IN ESCARPMENT OF 

PLATEAU NORTHWEST OF OPHEIM, MONT. 

0 . ESCARPMENT :oF THE FLAXVILLE PLATEAU, NORTHEASTERN 

MONTANA, SHOWING OUTCROPS OF CEMENTED SAND AND THE 

THICKNESS OF THE FLAXVILLE GRAVEL. 

• 

U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE LXIV 

A. CEMENTED GRAVEL INTERSTRATIFIED WITH CEMENTED SAND 9 

MILES NORTHEAST OF SCOBEY, MONT. 

B. CROSS-BEDDING OF FLAXVILLE GRAVEL 5 MILES WEST OF 

WEST FORK POST OFFICE, MONT. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 108 PLATE LXV 

A. RAILWAY CUT WEST OF FLAXVILLE, MONT 

B. ESCARPMENT SURROUNDING THE LATE PLIOCENE OR EARLY; 

PLEISTOCENE BENCH IN MILK RIVER VALLEY, MONT. 

0. VANDALIA DAM, MILK RIVER, MONT., SHOWING THE ESCARPMENT 

SURROUNDING THE LATE PLIOCENE OR EARLY PLEISTOCENE BENCH. 

• 
THE FLAXVILLE GRAVEL OF THE NORTHERN GREAT PLAINS. 183 

epoch.~ This valley contains alluvium deposited by Missouri River, glacial drift, and th~ 

Recent alluvium of Milk River and is bounded 

on the north and south by steep escarpments 

rising 100 to 500 feet to the late Pliocene or early 

Pleistocene bench. Plate LXV, B and 0, shows 

views of these escarpments taken from the 

flood plain of Milk River. Big Muddy Creek 

flows in a valley cut 200 feet in the same bench. 

Similar benches are found along Poplar River 

and its branches. The canyon of Rock Creek 

where it crosses the bench is so precipitous as 

to have been considered unsurveyable by the 

United States Land Office. Frenchman Creek 

and Woody Island Coulee occ~py narrow val-

.leys, arid the latter was diverted from its old 

course westward into Whitewater Creek by 

the last glacial advance. 

OLIGOCENE BEDS IN CYPRESS HILLS. 

In 1883 and 1884 McConnell 2 and Weston, 

of the Canada · Geological Survey, examined 

the Cypress Hills and made a very good collection of fossil vertebrates at Bone Coulee, 

in the east end of the hills. This collection 

was submitted to Cope,3 who identified several 

species and pronounced them to be of Oligocene age and equivalent to the fauna of the 

White River formation of Nebraska. The 

locality was visited in 190~ by Lambe/ who 

made further collections of the fauna and 

reaffirmed the determination that the beds are 

of White River age. 

The formation exposed in the Cypress Hills 

is shown on McConnell's map as capping a 

series of plateaus ranging from 3, 700 feet in 

altitude at the east to 4,800 feet at the west. 

The gravel· on the Swift Current Creek plateau, 

which lies northeast of the Cypress Hills, is 

regarded by McConnell 5 as an eastern extension of the Oligocene gravel, though only . un1 Calhoun, F. H. H., The Montana lobe of the Keewatin ice sheet: 

U.S. Geol. Survey Prof. Paper 50, pp. 32-45, 1906. 

2McConnell, R. G., On the Cypress Hills, Wood Mountain, and adjacent country: Canada Geol. Survey Ann. Rept., vol. 1, new. ser., pp. 

1c-78c, 1886. 

a cope, E. D., The Vertebrata of the Swift Current Creek region of the 

Cypres11 Hills: Idem, pp. 79c-85c; The species from the Oligocene or 

lower Miocene. beds of the Cypress Hills: Canada Geol. Survey Contr. 

Canadian Paleontology, 1891. 

4 Lambe; L. M., A new species of H.vracodon (H. priscidens) from the 

Oligocene of the Cypress Hills, Assiniboia: Canada Roy. Soc. Proc. and 

Trans., 2d ser., vol. 11, sec. 4, pp. 37-42, 1906; Fossil horses of the Oligocene of the Cypress Hills; Idem, pp. 43-52; Vertebrata of the Oligocene 

of the Cypress Hills; Saskatchewan: Canada Geol. Survey Contr. Paleontology, vol. 3, pt. 4, 1908. 

6McConnell, R. G., op. cit., p . 34c. 

I 

I . 

identifiable bone fragments were found in it. 

As its altitude is about: 2,900 feet, or 200 feet 

below that of the nearest exposure of Flaxville 

gravel, it is suggested by the writers that a 

more thorough' search might result in the discovery of the Flaxville fauna. The Oligocene 

beds exposed near Bone Coulee, Cypress Hills, 

are described by McConnell 6 as follows: 

The Miocene [Oligocene] beds are characterized by the 

great quantity of waterwom pebbles, derived from the 

quartzite for~ations of the Rpcky Mountains, which are 

found in every part of the series. The pebbles are usually cemented together 1nto massive beds of hard conglomerate but also occur distributed irregularly through 

or ananged 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 beds] are all very irregular and 

seldom remain constant in composition for · any distance 

along their strike. 

SUMMARY. 

The gravel that caps the Cypress Hills in . 

Canada is of Oligocene (White River) age. -It 

is made up of materials from the Rocky 

Mountains, to the west, . and rests upon a 

series of plateaus cut on the Fort Union, Lance, 

and Bearpaw formations and ranging from 

4,800 feet in altitude at its west end to 3, 700 

feet ne~r its east end. 

The Flaxville gravel in Montana is from a 

few feet to 100 feet thick and is composed of 

well-rounded quartzite and argillite pebbles 

from the Rocky Mountains, sand, clay, marl, 

and volcanic ash. It rests upon a series of 

plateaus cut on the Fort Union, Lance, and 

Bearpaw formations, and ranging in altitude 

from 2,600 feet at the east to 3,200 feet at the 

west. Fragmentary fossils collected at 25 

well-distributed localities were not good enough 

for specific determination, but it can be stated 

positively that the formation can not be older 

than Miocene nor younger than early Pliocene. 

Below the Flaxville level there are extensive 

areas, eroded since its deposition, on which the 

covering is thin or absent. Stratified gravels 

and silts have been noted at several localities. 

A single fossil tooth collected from one of these 

exposures of gravel was identified as that of a 

horse resembling the living species. It certainly is not so old as the fauna of the Flaxville 

gravel. The formation is known to be older 

than the advance of the Wisconsin glacier. 

6 Idem, p. 69c. 
184 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

It must therefore be of late Pliocene or early 

Pleistocene age. 

Present drainage has eroded valleys from 100 

to 500 feet below the late Pliocene bench. 

¥ost of . this cutting was accomplished before 

the advance of the Wisconsin glacier, whose 

drift deposits lie alike on uplands and bench 

lands and. in the valleys. 

The relative altitudes of these four erosion 

levels and the gravel assigned to them are 

3 • 700 ....--0=1.,...i g-oc-en-e-----. 

3,.100 ----------------

2,500 

Flaxville 'gravel 

.(Miocene or early Pliocene) 

is suggested but must be regarded as not yet 

proved. These relations are at present under 

investigation. 

Terrace gravel found by Bowen 2 in the 

neighborhood of Musselshell River, south of the 

Missouri, is probably either Oligocene or 

Miocene; that around the Bearpaw,a Little 

Rocky, Highwood, Judith, Big Snowy, Little 

Belt, Crazy, and other mountain groups is 

probably of Tertiary age and represents one 

2,200 ----- ---·- ------------ ----------------------------------------------

FIGURE 27.-Diagrammatic section showing the relative altitudes of the four erosion levels represented in northeastern Montana and the 

· adjacent part of Canada. 

shown diagrammatically in figure 27. The 

Oligocene of the Cypress Hills is the highest, 

the Miocene or early Pliocene Flaxville gravel 

bench represents a second stage of erosion and 

deposition, the late Pliocene or early Pleistocene 

bench a third stage, .and the late Pleistocene 

and Recent level a fourth stage'.· 

The correlation of these erosio:J;l levels with 

the Blackfoot peneplain and the second and 

third lower benches in the Glacier National 

Park region, described by Alden and Stebinger, 1 

1 Alden, W. C., and Stebinger, Eugene, Pre-Wisconsin glacial drift in 

the region of Glacier National Park, Mont.: Geol. Soc. America Bull., 

vol. 24, p. 569, 1913. 

or more of the erosion levels described. The 

relation of these erosion epochS to the physiographic history of the Rocky Mountains, as 

presented by Atwood 4 and Blackwelder, 5 is 

very problematic and can not be solved until · 

all the factors are known. 

2 Bowen, C. F., The anticlines of the Musselshell Valley (in preparation). 

a Bowen, C. F., The Cleveland coal field, Blaine County, Mont.: U.S. 

GeoL Survey Bull. 5~1, p. 348, 1912. 

'Atwood, W. W., The physiographic conditions at Butte, Mont.; and 

Bingham Canyon, Utah, when the copper ores in these districts wera 

enriched: Econ. Geology, vol. 11, pp. 697-7-\.9, 1916. 

5 Blackwelder, Eliot, Post-Cretaceous history of the mountains of 

central western Wyoming: Jour: Geology, vol. 23, Nos. 2, 3, and 4, 

May-June, 1915. 

0 
DEPARTMENT OF THE INTERIOR . 

FRANKLlN K. LANE, Secretary 

UNITED STATES GEOLO.GICAL SURVEY 

GEORGE OTIS SMITH, Director 

Professional Paper 108-K 

THE HELDERBERG- LIMESTONE OF 

CENTRAL PENNSYLVANIA 

BY 

JOHN B. REESIDE, JR. 

Published December 13,1917 

Shorter contributions to general geology, 1917 

(Pages 185-225) 

WASHINGTON 

GOVERNMENT PRINTING OFFICE 

1917 
CONTENTS. 

Introduction ........................................................................................... . 

Historical summary ............ _ ....................... _ . _ ... _ . _ ............... _ ... _ .................... . 

General features ofthe Tonoloway and Helderberg limestones .............. , ......... : ....................... . 

Tonoloway limestone .. ~ ....... _. ____ .... _._ ... _. ___ ~ __ ._. _____ ._._ · _________ ._._._ ... _ ... __ ._ ....... . 

Helderberg limestone ................. ___ . __ .... __ . __ . __ ... _ ... _ . _ . _ .. __ . ______ ... _ . _ . _ .. __ ... _ ...... . 

General character ......................... _ . _ ... _ ... _ . _ ... _ ... _ ... _ ............ . ..... _ ............ . 

Keyser limestone member ............................................ ~ .................. ~ ....... . 

Salient features ....................... ·. : . ................ , ....... , ....... _ ..... _ .............. . 

Chonetes jerseyensis zone .. · ................................. : _-_ ............................ , ... . 

Transition zone ..................................... : ... ~ ... ~ ................. , .............. . 

Favosites helderbergiae var. praecedens zone . _ ......... _ .........•................................. 

Coeymans limestone member ........................................... _ ........................ . 

New Scotland limestone member .... _ ................................... _ ........................ . 

Becraft limestone member .......................................................... __ ,_ ........ . 

Correlation of the Tonoloway limestone ........................................ _ ..... _ ... _ ................ . 

Correlation ofthe Helderberg limestone ............................................. _ ..... ~ .............. . 

Keyser limestone member ................................................ . ......... _ ... .. ........... . 

Correlation with beds in Maryland .. _ ......................................... _ ....... _ .......... . 

Correlation with beds inN ew Jersey .................................... _ ... _ ... _ ................ . 

Correlation with beds in New York .................................... . ........ · .................. . 

· Formations east of the Helderberg Mountains ...................... ~ ...................... ~ ... . 

Formations west of the Helderberg Mountains ................................................ . 

Coeymans, New Scotland, and Becraft elements in the Keyser fauna ........ _-_ ..................... . 

. Analysis of the fauna .........•................................ ~ ............................... ~:. 

Age of the Keyser limestone member ....... ~ .. ~ .............•.................... ~ ............... . 

Coeymans limestone member ........................... · ................................... : ......... . 

New Scotland limestone member ........... .' ......................................................... . 

Distribution of the fauna ...................................•.... . .............. . .......................... 

Summary .................................................... _ ......... _·_ ............................... . 

Local sections ofthe Tonoloway and Helderberg limestones ............................................... .. 

Lincoln and Fifteenth streets, Tyrone ................................................................. . 

Pennsylvania Avenue, Tyrone ......... · :'.'>- .••..••.......... ; ..........•.........•...•...........•...• 

Mapleton •............................................................ · ........................... , .. 

· Mount Rock, Lewistown ........................................... _ .................. ~ _ ..... _ ....... . 

Clark's Mill, northwest of New Bloomfield ....................... ~ ..................................... . Dalmatia .............................. _. __ .. __ · __ .-. ___ ._. ___________ ._. ____ ._ ·_._. ________ " __ . ___ .... . 

Selinsgrove Junction ........................... _-_ .. ___ ._ ......... __ ............. _._ .. _._._._._._. ___ . 

Grovania ... -..................•.. __ . _ . ___ . ___ . ___ . _ . ___________ . _ . _ . _ . _ .• ____ . _ . _ . ~ . _. _. ___ . _ . ___ . ___ _ 

- ·; .... 

ILJ_;USTRATIONS. 

Page. 

185 

185 

187 

187 

188 

188 

188 

188 

190 

191 

191 

192 

192 

193 

193 

194 

194 

194 

195 

196 

196 

- 196 

197 

197 

198 

199 ' 

199 

199 

204 

204 

204 

206 

209 

212 

214 

216 

220 

224 

Page. 

·FIGURE 28. Map showing outcrops of Helderberg limestone in Pennsylvania and Maryland.................... 189 

29. Diagram showing relations of the zones and subzones of the Keyser limestone member of the Helderberg limestone in Pennsylvania. _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190 

30. Diagram showing relations of the' zones and subzones of the Keyser limestone member of the Helderberg limestone in Maryland ........................................................... "...... 194 

II 
THE HELDERBERG LIMESTONE OF CENTRAL PENNSYLVANIA. 

By JoHN B. REESIDE, Jr. 

INTRODUCTION. 

This paper .presents the results of a study 

made during 1913, 1914, and 1915, while the 

writer was a student at Johns Hopkins University. The formations discussed have been 

studied in Maryland, New Jersey, and New 

York, and described with more or less detail, 

but concerning their occurrence in the intervening area in Pennsylvania little exact information has been available. The conflict in 

opinion as to the proper position and correlation of the Keyser limestone and as to the 

interpretation of some of the standard New 

York sections has made further data very 

desirable, and the present paper is an attempt 

to meet a part of the deficiency. 

The writer wishes to express his indebtedness to the members of the geologic faculty of 

Johns Hopkins University, especially to Prof. 

W. B. Clark and Prof. 0. K. Swartz, and for 

many helpful suggestions also to Mr. E. 0. 

Ulrich, Mr. _ Charles Butts, and Mr. Arthur 

Keith, of the United States Geological Survey .. 

HISTORICAL SUMMARY. 

The first systematic discussion of the rocks 

of Pennsylvania is contained in the first annual 

report of H. D. Rogers, as State geologist, to 

the Pennsylvania legislature, made in 1836.1 

The present Helderberg limestone and an 

indeterminate thickness of late Silurian beds 

seem to -be included in his division "No. 6 " 

which is described 2 as "an argillaceous bl~e limestone" that "contains between its beds 

thin layers of shale resembling that last described (No. 5), though these grow less as we 

ascend, while the rock becomes progressively 

purer and less argillaceous." Rogers states 

1 Rogers, H. D., Pennsylvania State Geologist First Ann. Rept., 

Harrisburg, 1836. 

2 Idem, p. 14. 

also: "This stratum is terminated by layers of 

gray chert." In later reports Rogers used the 

Roman numeral (VI). · 

In 1843 Mather 3 correlated his Pentamerus 

limestone with Rogers's No. Vi, and in the 

same year James Hall 4 correlated the beds in 

the interval from the Niagara group to the, 

"Upper Pentamerus" _limestone inclusive with 

Rogers's No. VI. 

In 1858 Rogers, in the long-delayed final 

report of the First Pennsylvania Survey, 

applied the so-called transcendental nomenclature to supplement the numerical designa,tion 

of the preliminary reports. To No. V, the 

"Scalent series," he assigned three divisionsthe uppermost of which he described 1 as 

a blue fiaggy limestone, sometimes containing bands of 

chert. Certain portions have thin-bedded, wavy stratification * * * This -rock contains the Cytheri7w alta, 

Tentaculites ornatus, and a few other distinctive fossils. 

No. VI, .the "Pre-Meridian series," he de:.. 

scribed 1 as 

a diverE;ified calcareous formation, usually of some shade 

of grayish blue. It is argillaceous and fiaggy in its lower 

beds and shaly toward the middle. It frequently contains layers and n?dules 'of chert, especially near its 

upper limits. It has many characteristic fossils, the Pentamerus galeatus·and other shells, with corals. 

Overlying these is the ":Meridian slate," 

which apparently includes the shales at the 

top of the New Scotland and at the base of 

the Oriskany. Rogers correlated the limestone of his No. V with the "Waterlime" of 

New York, and his No. VI with the ''Lower 

Helderberg" of New York; In discussing ·the 

rocks of the United States as a whole Rogers 

seems to transfer the "Meridian slate" and 

the "Sea lent" limestone to the "Pre-Meridian 

3 Mather, W. W., Geology ofNew York, pt. 1 [First district], p. 325, 

1843. 

4 Hall, James, Geology of New York, pt. 4 [Fourth district], pp. 80, 

144, 145, 519, 1843. 5 Rogers, H. D., Geology of Pennsylvania, vol. 1, p. 107, 1858. 

185 
186 SHORTER CON·TR.IBUTIONS TO GENERAL GEOLOGY, 1917. 

series." Hence in its larger ·aspect No. VI 

included the limestones of the late Silurian, 

the Helderberg, and the shales of the Oriskany. 

In 1874 was established the Second Geological Survey of Pennsylvania, under J. P. 

Lesley. During the following 20 years this 

organization. issued many county · and special 

reports, in which the utmost freedom was 

allowed to the severa~ geologists in the usage 

of stratigraphic names. The volumes therefore disagree among themselves. Very little 

detailed st:ratigraphio discussion is given in 

these reports. The f{)llowing table shows the 

usage of the several geologists in describing 

the sections discussed in another part of thispaper: 

New York and its far more extE)nsive and numerous lines 

of outcrop through Pennsylvania, it would be simply.misleading to describe it as composed of any fixed number of 

beds, or groups of beds, arranged in a definite series, each 

group characterized by one or more species of organic 

form. All that can be said of it with truth is this: (1), 

that it is mainly a limestone formation, underlying the 

whitish sandstone formation No. VII and overlying the 

reddish shale formation No. V; (2), that many of its beds are 

crowded with Pentamerus, Delthyris, Tentaculites, encrinal 

stems, and masses of coral; (3), that one or more of its beds 

are nearly solid layers of the sponge coral Stromatopora,· 

(4), that at its bottom, whether included in it or not, are 

hydraulic limestone beds, containing the remains of lobsterlike creatures, Eurypterus and Polygnotus,· and (5 ), 

that it might perhaps be made by a downward extension 

to include the whole Salina ·shale and Niagara limestone 

formations of western New York and Canada, were it not 

for the extraordinary thickness of the Salina · red shales, 

Usage of the Second Pennsylvania Geological Survey, correlated with stratigraphic div1'sions of the present paper. 

Claypole, D'Invilliers, White, Platt, 

This report. White, White, White, Perry Mifflin Huntington Blair 

Grovania.a Selinsgrove. b Dalmatia.b County, County, County, County, Clark'sMill.c Lewistown. d M,apleton. e Tyrone.! 

---

Oriskany. Oriskany. Oriskany. . Oriskany. Oriskany. Oriskany. Oriskany. 

Oriskany. 

Stormville 

Stormville shale. 

Stormville Stormville Lime shale. 

shales. shales. shales. 

New Flint Lime shale. 

Scotland. shales. Q.) 

~ ~ 

0 

+=> Q.) Q) Stormville tll 

Q) 

~ Coeymans. ] ~ 

""' conglomerate. Stormville 0 

Lewistown Q) 

Stormville +=> 

~ tll 

and Q) Massive Q) and ~ limestone. ~ Bastard ] Bastard !5: limestone. 

Stormville limestones. ·clarks 0 

limestones. +=> Lower Keyser. and Bastard Mill ':11 

-~ massive !5: 

limestones. shales. 0 Q) limestone. +=> ,...::; <ll 

·~ Q) 

H 

Tonoloway. Bossard ville. Bossardville. Bossard ville. Lewistown. Shaly · limestone. 

a Peimsylvania Second Geol. Smvey Rept. G7, p. 88, 1883. b Idem, p.'93. c Idem, Rept. F2, p. 182, 1885. 

a Idem, Rept. F3, p. 256, 1891. e Idem, Rept. T3, 1885. I Idem, Rept. T, 1881. 

In 1892 Lesley 1 correlated No. VI in a 

general way with the "Lower Helderberg" 

(Helderberg) of New York, which he regarded 

as Silurian. His oomn1ent on this subject is 

characteristic: 

Considering the great variety of thickness, quality, 

order of subdivision, and fossil distribution exhibited by 

the formation as a whole along .its northern outcrop through 

I Lesley, J. P.1 Pennsylvania Second Geol. Survey Summary Final 

Rept., vol. 2, p. 904, 1892. 

especially in Pennsylvania, by which the Niagara is very 

far separated from the limestones of No. VI above. 

In 1903 Schuchert 2 stated that he had 

traced the Cobleskill and Manlius faunas 

through New Jersey, Pennsylvania, Maryland, 

and West Virginia, and that in central Penn- . 

sylvania these are still distinct, but that. they 

become more confused in Maryland. 

2 Schuchert, Charles, On the Manlius formation of New. York: Am. 

Geologist, vol. 31, p. 176, 1903. 
HELDERBERG LIMESTONE OF CENTRAL PENNSYLVANIA. 187 

In 1906 Grabau 1 considered White's Stormville limestone of Pennsylvania to represent 

. the Manlius and in part • the Coeymans. The 

top of this limestone he believed to represent 

generally a marked break, indicated by conglomerate beds, composed at many places 

almost entirely of quartz. The section at 

Grovania, Pa., he cited as an example of over.,. 

lap, the sandstone present being considtlred 

New Scotland and the underlying limestone 

Manlius and Decker. 

In 1909 Grabau 2 expressed the view that the 

Lewistown represented only the upper part of 

his Monroan series-that is, the RosendaleManlius interval of New York. 

In 1911 Ulrich 3 announced the presence of 

. an unconformity of considerable time significance in certain beds of the Appalachian region 

previously referred to the upper Cayugan. 

The rocks between this horizon and another 

well up in the Coeymans of Schuchert -and 

other authors he referred to as the Keyser 

limestone . For the Silurian beds beneath the 

Keyser limestone he used the name Tonoloway 

limestone. Ulrich did not discuss either unit 

in detail. 

In 1912 Stose 4 gave an adequate description of the Tonoloway limestone and presented 

a statement (furnished by Ulrich) of the fauna 

and of its correlation. In this statement the 

beds just above the Tonoloway limestone were 

differentiated, as'' the lowest faunal zone of the 

Helderberg," from the beds containing the 

Coeymans, New Scotland, and Becraft faunas. 

In 1913 Grabau 5 suggested the occurrence of 

the Bertie limestone at Selinsgrove Junction, 

Pa., and again referred the entire Lewistown to 

his upper Monro an, disputing the reference of the 

Keyser and equivalent beds to the Devonian. 

In 1913 also Brown,6 on paleontologic evidence, considered the Decker and Rondout 

present in Milesburg Gap, near Bellefonte, Pa. 

I Grabau, A. W., Guide to the geology and paleontology of the Schoharie Valley in eastern New York: New York State Mus. Bull. 92, p. 

173, 1906. 

2 Grabau, A. W., Physical and faunal evolution of North America 

during Ordovicic, Siluric, and early Devonic time: Jour. Geology, vol. 

17, p. 247, 1909. 

3 Ulrich, E. 0., Revision of the Paleozoic systems: Geol. Soc. America 

Bull., vol. 22, p. 590, 1911. 

• Stose, G. W., U.S. Geol. Survey Geol. Atlas, Pawpaw-Hancock folio 

(No. 179), p. 7, 1912. 

5 Grabau, A. \V., Early Paleozoic delta deposits of North America: 

Geol. Soc. America Bull., vol. 24, p. 510, 1913. 

6 Brown, T. C., Notes on the Simrian limestone of Milesburg Gap, ncar 

Bellefonte, Pa.: Am. Jour. Sci., 4th ser., vol. 35, p. 83, 1913. 

In the same year the Maryland Geological 

Survey/ in its volume on the Lower Devonian 

of Maryland, divided the Helderberg into the 

K.eyser, Coeymans, New Scotland, and Becraft 

members, named in ascen.ding order. The last 

three were correlated with the divisions of the 

same names in Pennsylvania and other States, 

and the Keyser with beds in sections at Clark's. 

mill, Selinsgrove Junction, and Grovania, Pa., 

which are discussed in some detail. Regarding 

the State as a whole, the suggestion was made 

that the top of the Keyser is a plane of unconformity. 

Schuchert 8 in 1916 gave a brief discussion 

of the section in the Tyrone region. He 

attributed all the beds referable to the Helderbergian to the Keyser limestone, and expressed 

the opinion that there is a marked stratigraphic 

break at the top of the Keyser and possibly 

another at the base. · 

As this brief summary indicates, the an1ount 

of detailed information available concerning 

the Lower Devonian and late Silurian horizons 

of Pennsylvania leaves much to be desired. 

The present study of seven selected localities, 

it is hoped, will contribute toward the solution 

of some of the problems involved, though the 

writer recognizes fully the difficultie~ and 

limitations imposed upon correlations which 

are made without field work throughout the 

areas between the exposures discussed and 

which · are based entirely upon the fossils 

collected. 

GENERAL FEATURES OF THE TONOLOWAY AND 

HELDERBERG LIMESTONES. 

TONOLOWAY LIMESTONE. 

The type expos·ures of the Tonoloway limestone are . in the lower slopes of Tonoloway 

Ridge, and the type locality is just west of 

Rock Ford, W. Va., where Great Cacapon 

River cuts through the ridge. The name was 

given by Ulrich, as 

1

stated above, but the formation was first adequately described by 

Stose.4 Typically it is composed of finely 

laminated light-gra:y limestone and calcareous 

shale and is generally more shaly toward the 

top. 

7 Maryland Geol. Survey, Lower Devonian, 1913. 

s Schuchert, Charles, Silurian formations of southeastern New. York, 

New Jersey, and Pennsylvania: Geol. Soc. America Bull., vol. 27, p. 

.552, 1916. 
188 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

The Tonoloway formation in central Pennsylvania has, at all the exposures studied except 

Tyrone, the same chatacteristic lithology, consisting of platy, in places laminated fine-grained 

gray limestones . and calcareous shales. The 

uppermost beds in the Susqueha,nna region are 

heavy, pure, and very dark. At Tyrone the 

sharp. Even_ where the uppermost Tonoloway 

is massive, the nodular structure of· the Keyser 

permits a separation. 

HELDERBERG LIMESTONE. 

GENERAL CHARACTER. 

The Helderberg formation is a series of calstrata referred to the Tonoloway are relatively careous deposits of varied character. It in~ light cream-colored to buff limestones, in eludes some shale but is chiefly limestone. In 

places platy and in places containing shale. lithology individual beds may represent any These beds probably- represent a special facies stage in the gradation between a coarse· agglomvery much like the Wills Creek shale of Mary- eration of fossil fragments and a dense, very land. Indeed, if there were sufficient evi- fine grained subcrystalline rock, or between a 

dence of an unconformity and hiatus at the somewhat calcareous shale and a laminated 

top, the lithology of .these beds would suggest their correlation with the Wills Creek. . The impure limestone. Some parts of the formation have in all exposures much bedded ·chert, 

Tonoloway at Tyrone also contains a bed of and locally chert is present as nodules in other 

material that seems to be siliceous oolite. parts of the formation. In very minor quan- The Tonoloway is not fully exposed at any of the localities studied; The maximum thick- tity arenaceous limestone and even calcareous 

ness observed is 325 feet. sandstone are present. Figure 28 shows the surface distribution of 

The fauna of the Tonoloway in Pennsyl- the ·Helderberg limestone in Maryland and 

vania as displayed in the sections ~tudied com- Pennsylvania. prises Camarotoechia? lamellata, Camarotoechia Four members are rec9

gnized in the Helderlitchfieldensis, Spirijer keyserensis, Rhyncho- berg limestone-the Keyser limestone at the 

spira globosa var., Favosites sp. and other corals, . base, and above it, in order, the Coeymans 

Ectomaria min uta, Orthoceras sp., Leperditia limestone, the New Scotland' limestone, and 

sp., and other Ostracoda, Pelecypoda. Spirijer the Becraft limestone. 

keyserensis occurs in the thick upper beds at 

Lewistown and near Dalmatia. It also occurs 

at about the same horizon in the Maryland 

Tonoloway. Associated with it are the two 

KEYSER LIMESTONE MEMBER. 

SALIENT FEATURES. 

species of Camarotoechia. At Mapleton there The name Keyser limestone was first used by 

is a bed about 40 feet below the top of the Ulrich,! who cited Keyser, W.Va., as the source. 

Tonoloway which is very -fossiliferous. This He made several brief references as to its age 

bed carries Camarotoechia litchfieldensis, Spiror- and structural relation to the inclosing beds, 

bis laxus?, Proetus sp. ~' corals, Bryozoa, Pele- but gave no adequate discussion. The first decypoda, and abundant Leperditia. Below this tailed account of the Keyper is to be found in · 

is a bed with many poorly preserved brachio- the Lower Devonian volume of the Maryland 

pods, almost, all a species of Rhynchospira. Geological Survey cited above. This discus-

. Usually, however, the Tonoloway contains sion is considered under the heading ''Correlanothing but ostracodes, and in some pla:ces, as tionoftheHelderberglimestone" (pp.-194-199.) 

at Tyrone, even these are very r.are. All the · The Keyser limestone forms the larger part 

forms mentioned above occur also in the Mary- of the Helderberg of central Pennsylvania. It 

·land Tonoloway. is divisible into two major lithologic units-a 

The Tonoloway and Keyser succession has lower limestone series with many nodular 

been considered -by most observers as unin- layers and an upper series of relatively shaly 

terrupted, but Ulrich believes the two lime- limestone, which contains very few -nodular 

stones to be separated by a marked break. beds. At Tyrone no nodular limestone whatThe change from the platy fissile gray lime- ever was recognized, but everywhere else it is a 

stone of the Tonoloway to the much thicker- prominent feature. At Mapleton and near 

bedded nodular bluish limestone of the Keyser, 

In some places very dark iri color, is usually 1 Ulrich, E. 0., Revision of the Paleozoic systems: Geol. Soc. America 

Bull., vol. 22, pl. 28, 1911. · 
HELDERBERG LIMESTONE OF CENTRAL PENNSYLVANIA. 189 

Lewistown a thick bed of very pure massive 

crinoidal limestone lies near the base of the 

member. Here and there the Keyser contains 

chert and in many places Stromatopora-bearing 

beds. 

The thickness is variable in the area studied, 

ranging from 88 feet in one of the Tyrone .sections to 202 feet at Selinsgrove Junction. · 

LOCATION 

OF 

SECTIONS 

1. Tyrone 

2. Mapleton Depot 

3. Lewistown · 4. Clark's .Mill 

s. Dalmat-ic;~ 

6. Selinsgrove Junction 

7. Grovania 

p E 

Dalmatia a distinct transitional unit lies 

between them, and at Selinsgrove Junction and 

Clark's Mill _the faun~s mingle somewhat near 

the limits of the two zones. 

The Chonetes jerseyensis zone and the 

Favosites helderbergiae var. praecedens zone may · 

be divided into the following subzones, each 

with its diagnostic faunule: 

Scranton 

0 

0 50 100 MILES 

FIGURE 28.-Map showing outcrops of Helderberg limestone in Pennsylvania and Maryland. 

Two' m.ajor faunal units were recognized in 

the Keyser of Maryland, and were designated 

the Chonetes jerseyensis zone and ·the Favosites 

helderbergiae var.- praecedens zone.1 As corresponding faunal units are presep.t in the 

Key~er of Pennsylvania and agree in every 

essential with those found in Maryland, the 

same names will be used. The favositoid 

corals have not been studied in detail, but 

Favosites _ helderbergiae var. praecedens is known 

to occur in the Favosites z<_>ne in Pennsylvania. 

The faunal zones do not coincide with the two 

lithologic units described above. These faunal 

zones are sharply separated in some of the 

sections, but at Lewistown and south of 

I Swartz, C. K., Maryland Geol. Survey, Lower ·Devonian, p. 99, 1913. 

103969°--17----2 

Favosites helderbergiae var. praecedens zone: 

17. Upper Leperditia subzone. 

16. Tentaculites subzone. 

15. Stromatopora subzone B. 

14. Rensselaeria mutabilis subzone. 

13. Pholidops ovata subzone. 

12. Lower Leperditia subzone. 

_ 11. Coral subzone B. 

10. Spirifer vanuxemi var. prognosticus subzone. 

Chonetes jerseyensis zone: 

9. Calymene camerata subzone. 

8. Bryozoan subzone. 

7. Gypidula subzone. 

6. Dalmanella clarki subzone. 

5 .. Spirijer modestus subzone. 

4. Stromatopora subzone A : 

3. Coral subzone A. 

2. Rhynchospira subzone 

1. Camarotoechia? lamellata subzone. 
SH9RTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

Figure 29 shows the relations of the faunal fer modestus, Stenoschisma formosa, SchuchertZOD:es and subzones in the several sections ella deckerensis, and locally Orthostrophia 

and brings out the similarity of the faunal str~phomenoides, Dalmanella clarki, Sphaerosequence at most of the localities. studied. cystites multifasciatus, Tentaculites gyracanThe sections at,Grovania .and :Tyrone resemble · thus, Calymene camerata, Proetus profuberans, 

one another and . .. differ from those farther and Proetus pachydermatus. · 

south and east, reSpectively . . This fact sug- C6ral subzone A.~At Tyrone the Rhynchogests that some fundamental factor governing spira subzone is_ overlain by beds containing a 

the deposition of the ,Keyser had its effect profusion of Cladopora rectilineata and HaZyin a line nearly parallel to the present strike; sites catenulatus. Associated with them are 

possibly the amount of muddy sediment derived Strophonella leavenworthana var.1 Spirifer octofrom the land mass to the east permitted costatus, Atrypa reticularis, and Rhynchospira 

greater coralline growth away from its shore. globosa var. 

1/) 

(I) 

."!::!Ill 

tl)t: 

00 

>N 

~ 

1/) 

2Q) 

<llt: 

co 

ON 

..s:: 

u 

FEET 

150 

100 

50 

Mapleton 

)JE 25 miles )!'( 22 miles 31<. 

FIGURE 29.-Diagram showing relations of the zones and subzones of the Keyser limestone member of the Helderberg limestone in 

Pennsylvania. 

CHONETEs JERSEYENsis zoNE. Stromatopora subzone A.-At Selinsgrove 

G_amarotoechia? lamellata subzone.-.Oaina- Junction a 6-foot bed of stromatoporoids lies 

rotoechia? lamellata characterizes a subzone ·about 20.feet above the Rhynchospira subzone. 

at the base of nearly all the sections. It is This bed is represented at Grovania by·scattered 

especially well shown at Dalmatia and Selins- heads of stromatoporoids, at Dalmatia by a 

grove. Leperditia sp.~ Spirifer vanuxemi, and 6-inch layer of stromatoporoids, and at Clark's 

Rhynchospira globosa var. con:imonly occur in Mill by a unit that bears loose on the surface 

the subzone; Tentaculites gyracanthus, Pholi- numerous stromatoporoid fragments . . The 

dops ovata, Spirifer modestus, Orthostrophia stratigraphic position of these ·occurrences is 

strophomenoides, and Stenoschisma formosa are so nearly alike as to warrant the assumption 

less abundant. that they are at the same horizon. ' 

Rhynchospira globosa var. subzone.-Above Spirifer modestus subzone.-Above the Strothe Oamarotoechia? lamellata subzone a variety matopora subzone-A at Selinsgrove, Dalmatia, 

of Rhynchospira globosa is abundant. Asso- and·Clark's Mill a definite _ horizon is marked 

ciated with it are Atrypa reticularis, Chonetes by' an abundance of Spirifer modestus, assojerseyensis, Camarotoechia litchfieldensis, Lep- ciated with which are Camarotoechia litchfieldtaena rhomboidalis, Spirifer octocostatus, Spiri- ensiS, Chonetes jerseyensis, Rhynchospira for-
• 

.. 

HELDERBERG LIMESTONE OF CENTRAL PENNSYLVANIA. 191 . 

mosa, Schuchertella deckerensis, Stenoschisma 

formosa, Stenoschisma deckerensis, Oalymene 

· camerata, and undetermined corals and ostracodes. 

Dalmanella clarki subzone.-At ·Tyrone, 

Mapleton, and Lewistown Dalmanella clarki 

occurs between the Rhynchospira subzone and 

the Gypiilula subzone and seems to characterize · a definite horizon. The associated 

forms are very numerous and include most of 

the characteristic species of the Chonetes jerseyensis-zone. 

Gypidula coeymanensis var. prognostica subzo~.-At Lewisto·wn and Selinsgrove Junczone-and S pirifer vanuxemi prognosticus and 

Pholidops ovata-forms which are abundant 

only in the Favosites zone-are associated with 

or beneath species which are confined at most 

localities to the Chonetes jerseyensis zon~that 

is, Dalmanella concinna, Leptaena rhomboidalis, 

Btropheodonta bipartita, Strophonella geniculata, 

Oamarotoechia litchfielifensis, Atrypa reticularis, 

Merista typa, and Oalymene camerata. 

This transition zone varies in vertical thickness and in the number of subzones included 

in it in the four sections mentioned. 

FAVOSITES HELDERBERGIAE VAR. PRAECEDENS ZONE. 

tion Gypidula coeymanesis var. prognostica is The beds above the Oalymene camerata subabundant in a very massive nodular lime..: zone carry a fauna that is rather sharply sepstone. The form was not observed at any . arated from that of the Ohonetes zone. The 

other horizon nor at any other locality. The few forms which are common to both zones 

associated species are Atrypa reticularis, Ohone- differ much in relative abundance. Such forms 

tes jerseyensis, Dalmanella concinna, Merista as· Pholidops ovata, Spirifer vanuxemi var. 

typa, Leptaena rhomboidalis, Orthostrophia prognosticus, and Tentaculites gyracanthus are 

strophomenoides, Schuchertella deckerensis, Spi- unimportant members of the lower fauna, but 

rifer octocostatus, Stenoschisma deckerensis, they are abundant in the upper fauna. The 

Stenoschisma formosa, Proetus protuberans. complete absence of Atrypa reticularis . and 

Bryozoan subzone.-Above the Gypidula sub- Leptaena rhomboidalis from the upper zone and 

zone at Lewistown and at a c_orresponding their abundance in the underlying zone and 

horizon at Mapleton, Dalmatia, and Clark's the overlying Coeymans member is noteworthy. 

-Mill there is a profusion of unstudied Bryozoa. The presence of a transitional zone between 

At Tyrone and Selinsgrove a similar Bryozoan the Favosites and Chonetes zones in some of the 

zone seems to be present, though not conspic- sections modifies the sharpness of the separation 

~ous. The forms associated with the Bryozoa of the two faunas, but in general the statements 

include many of the characteristic species of made above hold good. 

the Chonetes jerseyensis zone. There are eight subzones in the Favosites 

Oalymene camerata subzone.-'--Oalymene came- zone. 

rata occurs above the Bryozoan subzone in Spirifer vanuxemi var. prognosticus subnearly all the sections. In several sections this zone.-Just above the Oalymene camerata subis the only occurrence, and in those in which zone in several of the sections an abundance of 

the fossil occurs at several horizons it is the Spirifer vanuxemi var. prognosticus marks 

highest one. The associated forms are com- apparently the same horizon. 

monly Atry;pa reticularis, Stropheodonta bi- Goral subzone B.-In the Grovania and 

partita, Merista typa, Dalmanella concinna, Tyrone sections a thick bed of massive limeLeptaena rhomboidalis, and less abundantly stone is composed of a profusion of Oladopora 

Schuchertella deckerensis, Oamaroto~chia litch- rectilineata, Halysites catenula_tus, Favosites sp., 

fieldensis, Rensselaeria mutabilis, Spirifer va- and other corals. Associated with these are 

nuxem~ var. prognosticus, and Uncinulus key- scattered heads of Stromatopora, Bryozoa, and 

serensis. 

TRANSITION ZONE. very rarely brachiopods of the genera Rhynchospira and .Oamarotoechia. At the top of this 

At Lewistown and Dalmatia and to a less subzone is. a bed of Stromatopora which might 

marked degree at Selinsgrove Junction and well be separated as a distinct subzone. At 

Clark's Mill Rensselaeria mutabilis, Beachia Mapleton this coral horizon is represented by 

· proaVita, and Uncinulus keyserensis-forms . a sparse occurrence of Oladopora rectilineata, 

which are usually confined to the Favosites Favosites, and other corals . 
192 ...:... 

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, ·1917. 

Lower Leperditia su.bzone.-Above the coral 

subzone Bat Tyrone and Mapleton there is an 

abundance of large Leperditias. These are 

associated at Mapleton with Uncinulus nucleolatus and Spirifer vanuxemi · prognosticus. At 

Selinsgrove Junction a zone with Leperditia 

was observed which seems to be identical with 

that occurring farther west. 

Pholidops ovata subzone.-Pholidops ovata 

occurs above the lower Leperditia subzone at 

Mapl~ton . and Selinsgrove .Junction and at a 

corresponding horizon in all the sections except 

at Tyrone. The associated forms are numerous 

and include species usually diagnostic of both 

Favosites and .Chonetes zones. 

Rensselaeria mutabilis subzone.-One of the 

· most persistent subzones of t_he Pennsylvania 

sections is that marked by Rensselaeria mutabilis. In some of the sections this subzone contains the only specimens of this form, in others 

it is the horizon of greatest abundance. The 

associated species are the cha!'acteristic forms 

of the · Favosites zone-S pirifer vanuxemi prognosticus, Uncinulus nucleolatus, Meristella 

praenuntia, and others. 

Mapleton Stromatopora subzone.-At Mapleton the beds carrying the . greatest abundance 

of Stromatopora are well . up in the section and 

correspond to the upper Stromatopora beds at 

Grovania and Tyrone. 

Tentaculites gyracanthus subzone.-A wellmarked and persistent subzone carries Tentaculites gyracanthus, though in some of the sections where Tentaculites occurs at numerous 

horizons this subzone can be identified only by 

the characteristic association with Schuchertella 

prolijica. 

Upper Leperditia subzone.-At Lewistown 

and Selinsgrove Junction Leperditia occurs at 

the very:summit of the Keyser. This subzone 

. may also be represented by the Leperditia at 

. the top of the Mapleton section, ·though this is 

doubtful. · · 

COEYMANS LIMESTONE MEMBER. 

. The Coeymans member is variable in· its 

lithology. In the west it is locally arenaceous 

at the base and consists of coarse ·crinoidal 

· limestone in the upper part. Farther east this 

sandy character extends through the whole of 

the member and becomes so pronounc~d at 

Grovania that the Coeymans 1s a sandstone. 

Usually chert is present. 

The thickness of the Co.e'Ymans in the sections studied varies from 3 to 10 feet, though 

it is possible 'that the minimum thickness should 

be increased by including some of the overlying 

limestone. · . · 

· The fauna is diagnostic, contairiing the characteristic ·species Gypidula coeymanensis, together with Atrypa reticularis, Oamarotoechia 

sp., Dalmanella perelegans, Leptaena · rhomboidalis, Lingula sp., Meristella sp., Phol-idops 

ovata, Rhipidomella oblata?, Sch~chertella woolworthana, Stropheodonta arata, Strophonella leavenworthana, Spirijer cyclopterus, Uncinulus sp., 

Dalmanites sp., and Phacopslogani. 

The Coeymans~Keyser boundary is everywhere strikingly clean cut. The uppermost 

beds of the Keyser are :P,laty, banded impure 

limestones. The base of the Coeymans is 

coarse, commonly arenaceous limestone or· 

sandstone. The faunal' change is likewise 

sharp. · · · 

NEW SCOTLAND LIMESTONE MEMBER. 

TheN ew Scotland member usually has a thin 

bed of limestone at its· base, above which lie · 

shales, interbedded in many places with impure 

limestone and with white chert. 

In the vicinity of Dalmatia the basal limestone is very thin or lacking. It was likewise 

not observed in Perry County.· At Tyrone it 

is 12 feet thick; at Lewif:?town, 6 feet; at Selinsgrove Junction, 12 feet; at Grovania it-seems 

to be about 13 feet thick and contains much 

shale. ·The limestone' is arenaceous at Selinsgrove Junction, but in most other places it is 

simply a coarse-grained bluish-gray fossiliferous 

rock. 

The fauna of the limestone contains the 

characteristic _ form Spirifer macropleurus and 

Atrypa reticularis?, Anoplotheca concava, Oamarotoechia sp., Ohoriostrophia helderbergiae, Dalmanetla p~relegans, Eatonia medialis, Meristellr} 

sp., Orbiculoidea sp., Rhipidomella oblata, Schuchertella woolworthana, Stropheodonta planulata?, 

Stropheodonta becki?, Strophonella · punctulifera, 

Spirifer cyclopterus, Spirifer perlamellosu-s, Uncinulus nucleolatus, Dalmanites pleuroptyx, Dalmanites micrurus, and Phacops log ani. 

The shale is ashy gray, fissile or splintery, 

and fine grained and contains more or less 

impure limestone in thin layers. It weathers 

yellow and is not usually very fossiliferous. 

The only measurement of the thickness, made 
, 

' 

HELDERBERG LIMESTONE OF CEN•T'RAL PENNSYLVANIA. 193 

at Selinsgrove Junction, gives a total of 44 feet. 

Some uncertainty as to the position of the upper 

boundary renders the accuracy of this figure 

only approximate. 

The shale -is relatively barren of fossils at 

most places, but at Dalmatia the following 

species were observed: Anoplotheca concava, 

Chonetes cf. 0. hemisphericus, Dalmanella perelegans, Meristella sp., Pholidops ovata, Stropheodonta becki, Strophonella punctulifera, Spirifer 

cyclopterus, Spirifer perlamellosus, and Phacops 

logani?. At the Emerick & Lebo quarry, 4 

miles northeast of Dalmatia, Spirifer macropleurus was foundin the shale. 

The New' Scotland-Coeymans boundary is not 

weU defined lithologically. The division has 

been made arbitrarily between the highest beds 

with Gypidula coeymanensis and the lowest with 

S pirifer macropleurus. 

BECRAFT LIMESTONE MEMBER. 

No lithologic or faunal evidence of the presence of the Becraft member of the Helderberg 

was obtained at any locality studied. 

CORRELATION OF TONOLOWAY LIMESTONE. 

The Tonoloway limestone of central Pennsylvania includes the beds at Grovania, Selinsgrove Junction, and Dalmatia, referred by I. C. 

White to the Bossardville limestone. It includes also the beds at Clark's Mill, referred by 

Claypole to .the Lewistown lin1estone, the tern1 

being used by him in a restricted sense. At 

the other localities treated in this paper it forms 

a part of "Formation No. VI," or the Lewistown lin1estone, these terms having been used 

so loosely as to prevent an exact statement of 

equivalency. 

The Tonoloway in Pennsylvania agrees in all 

its lithologic details with the formation of the 

same. name in Maryland. Both are mainly 

platy, laminated limestones. Both have, locally, heavy beds at the top. · 

As shown on page 188, the small fauna identified from Pennsylvania is duplicated in 

Maryland. Considering, then, the stratigraphic position, .lithologic similarity, and 

faunai likeness, the identity of the Maryland 

and Pennsylvania Tonoloway seems assured. 

The relations . with the formations toward 

the east -and north are more difficult to decipher. Lithologically and stratigraphically the 

Tonoloway resembles the BossaJ:dville limestone of New Jersey, but the lack of paleontologic evidence from the Bossardville renders 

correlation with it uncertain. Oamarotoechia? 

lamellata and Oamar~toechia litchfieldensis 

occur in the Decker limestone of New Jersey 

and in the Cobleskill and Rondout of eastern 

New York. Theformer species occurs in the 

Cobleskill and Rondout and Ectomaria minuta 

in the Manlius of central New York. Inasmuch as these three forms occur also in the 

Keyser, it seems jnadvisable to say more at 

present than that the Tonoloway is eqtlivalent 

to some part of the late Silurian of the standard 

New York section. 

CORRELATION OF HELDERBERG LIMESTONE. 

KEYSER LIMESTONE MEMBER. 

CORRELATION WITH BEDS IN MARYLAND. 

The Keyser member of the Helderberg in 

Pennsylvania duplicates in a striking way the 

lithologic succession in Maryland. The lower 

beds in both are nodular and the upper relatively shaly. Banded, l~minated impure limestones of varying thickness occur at the top of 

both. Both have Stromatopora reefs, and both 

have locally, as at Lewistown and Mapleton, 

a heavy crinoidal bed near the base~ 

The faunal likeness of the Pennsylvania sections (except those at Tyrone and Grovania) 

to sections in Maryland is as striking as the 

similarity in lithology. The same species· occur 

with much the same stratigraphic ranges in 

both States. The same two major faunal 

zones are recognized in both, and these are 

divided into subzones which correspond In a 

remarkable fashion in the two areas. (See 

figs. 29, p. 190, and 30, p. 194.) 

The following table affords a comparison: 

Central Pennsylvania. Maryland.! 

Favosites zone: 

17. Upper Leperditia sub- i4. Leperditia subzone. 

zone. 

13. Corriganville Stromatopora subzone. 

16. Tentaculiiessubzone .. _. 12. Tentaculites subzone. 

15. StromatoporasubzoneB. 11. Corriganville lower 

Stromatopora subzone. 

14. Rensselaeria mutabilis 10. Rensselaeria subsubzone. 

13 . . Pholidops ovata sub .. 

zone. 

zone~ 

(P r e s e n t , not 

named?) 

1 Swartz, C. K., Maryland Geol. Survey, Lower Devonian, p. 99, 1913. 
194 SHO~TER CONTRIBUTIONS TO GENERAL GEOLOGY, 19'17. 

Central Pennsylvania. 

Favosites zone-Continued. 

12 .. Lower Leperditia ·subzone. 

11. Coral subzone B........ 9. 

10. Spirifer vanuxemi prog..,_ 

nosticus subzone. 

Chonetes zone: 

·Maryland. 

(P r e · s e D. t , not 

named?) 

Keyser coral reef. 

(P r e s e n t , not 

named?) 

9. Calymene camerata sub- (Pres en t, not 

zone. named?) 

8. Bryozoan subzone. . .... 8. Bryozoan subzone. 

7. Gypidula subzone ..... _ 7. Gypidula subzone. 

··FEET 

300 

- _;.... ___ _ 

At Market Street Bridge, Cumberland, Md., 

there is an abundance of Oamarotoechia lamel- . 

lata near the base of the Keyser, which probably represents subzone 1 of central Pennsylvania. The occurrence of Dalmanella clarki at 

Cash Valley, about 3! miles southwest of Cumberland, Md., harmonizes very well with sub.:.~ 

zorie 6 of Pennsylvania. Spirifer vanuxemi 

var. prognosticus o'ccurs at Millers Spring, near 

Ridgely, Md., at about the horizon of subzone 

14 !4 ----------------- PENNSYLVANIA 

EQUIVALENT 

= 17 PA. 

Z50 

200 

100 

50 . 

0 

\) -ci ~ ::E 

;:. ..x"' ro u 

~ 0 

u 0 c 0 ro c :r: 0 

1-

FIGURE 30.-Diagram showing relations of the zon~s and subzones of the Keyser limestone member of the_ Helderberg limestone in Maryland. 

6. Dalmanella clarki sub- (P r e s e n t , not 

zone. named?) 

5. Spirijer . modestus sub- 6. Cystid-Spirifer subzone. 

4. Stromatopora subzone A. 

3. Coral subzone A ........ . 

2. Rhynchospira subzone ... 

1. Camarotoechia? lamellata subzone. 

zone. 

5. Rawlings Stromatopora reef. 

4. Cladopora rectilineata 

subzone. · 

2, 3. Rhynchospira subzone. 

(P r e s e n t , not 

named?) 

10 of Pennsylvania. Leperditia gigantea occurs at Devils Backbone, near Cumberland, 

Md., above the "Corriganville lower · Strornatopora'.reef '' a~d may represent subzone 12 of 

Pennsylvania. · The. Pholidops · ovata subzone 

and Oalymene camerata subzone probably have 

p1:1rallel occurrences in Maryland. In short, 

the subzones of the more central sections lJl 

Pennsylvania are practically duplicated 1n 

Maryland. 
'Oil:' 

I 

• 

HELDERBERG LIMESTONE OF CENTRAL PENNSYLVANIA. 195 

. The sections at Tyrone and Grovania, however, offer some difficulty. In both the fauna 

of the Chonetes jerseyensis zone is well devetoped, though some of the subzones that are 

well .marked in the other sections are not disWeller contains many corals, including Cladopora rectilineata and Halysites catenulatus. The 

coral subzone A seems to correspond best 

with this zone, though it might possibly be 

equivalent to the coral· subzone B. 

cernible in these two. The Favosi{es zone is The fauna ~f the Chonetes jerseyensis zone of 

characterized by the great abundance of corals Pennsylvania as a whole shows a marked relaa.nd stromatoporoids. On the other hand, the · tion to that of the Decker limestone of New 

remaining members of the upper fauna are Jersey. Of.41 species identified in the Chonetes 

conspicuously absent at Tyrone and almost jerseyensis zone of Pennsylvania 18, or 44 per 

lacking at Grovania. There are no sections in cent, occur in the Decker and include its most 

the Maryland area which present these pecul- diagnostic forms. It is probable that further 

iarities nor that of the small thickness shown study of the corals, pelecypods, ostracodes, 

in these two Pennsylvania sections. Possibly and Bryozoa will show that the percentage of 

the facies exposed at Tyrone and Grovania is species common to the two units is still greater. 

buried beneath the ·later rocks of . western A very marked difference between the Decker 

Maryland, for the sections of the westernmost 

Maryland exposures most closely resemble 

those at Mapleton, Lewistown, and Selinsgrove. The chief difference lies in the lesser 

thickness in Pennsylvania. 

These facts lead to the conclusion that the 

Keyser member of the Helderberg in Maryland and the Keyser member in cent:ral Pennsylvania are essentially identical. 

CORRELATION WITH BEDS IN NEW JERSEY. 

limestone and the Chonetes jerseyensis zone of 

the Keyser limestone is the notable percentage of Devonian (typical Coeymans, New 

Scotland, and Becraft) forms in the Keyser. 

Three such species are present in New Jersey, 

but in Pennsylvania . there are nine. In 

Maryland there are still more. 

The lithology of the Decker is also like that 

of the Chonetes jerseyensis zone. The lithologic, faunal, and stratigraphic similarity therefore shows that the two units are essentially 

Weller 1 divided the Lower Devonian and the same. If the coral subzone B is the equivalate Silurian limestones of New Jersey as lent of the coralline zone of the Decker, the 

follows: . . upper beds of the Decker are younger than the 

Helderberg: upper beds of the Chonetes jerseyensis zone of 

Becraft. the Keyser. The faunal succession given on 

· New Scotland. ·page 194 makes it very likely that the coral reef 

Coeymans. d · · 1 Silurian: of the Keyser of Marylan IS equ1va ent to the 

Manlius. coral subzone B. As the coral reef of the KeyRondout. ser contains a numbt3r of species which are limDecker Ferry. ited to the Favosites zone, the coral subzone B . 

Bossardville. is probably not the equivalent of the coralline 

The probable equivalence of the Bossard- zone of the Decker. If, as seems more prob-. 

ville and the Tonoloway has been mentioned ·able, then, the coral subzone A is the equiva-

(p. 193). lent of the coralline zone of the Decker, the upThe Decker (or "Decker Ferry" limestone) per beds of the Chonetes jerseyensis zone are 

was divided by Weller 2 into the Chonetes younger than the upper beds of the Decker. 

jerseyensis zone, the Ptilodictya frondosa · zoneJ The Rondout of New Jersey has no welland the Rhynchonella lameilata zone. The defined equivalent in Pennsylvania. The presChonetes jerseyensis zone contains a fauna ence of Leperditia in the Favosites zone suggests 

which has many forms common in the lower similarity of conditions, but there is no real 

zone of the Pennsylvania Keyser. The Ptilo- evidence of equivalency. 

dictyafrondosa zone, which is very thin in New The Marilius of New Jersey is characterized 

Jersey, has not been recognized in Pennsyl- by the presence of Strdmatopora-bearing beds 

vania. The Rhynchonella lemellata zone of and an abundance of Spirifer vanuxemi, Strot Weller, Stuart, Paleontology of New Jersey, vol. 3, p. 9, 1903. 

2 Idem, p. 67. 

pheodonta varistriata, and Leperditia altq,~ Tentaculites gyracanthus occurs but is rare. The 
196 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

Favosites zone of ~he Keyser of Pennsylvania 

contains stromatoporoids at _three localities. 

Tentac1#lites gyracanthus occurs abundantly in 

it at four localities, ra-rely at Mapleton, and not 

at all at Grovania and Tyrone. Spirijer vanuxemi is represented by the variety prognosticus, a very abundant form in the Favosites 

zone _of most of the sections, except again 

Tyrone and Grovania. This variety occurs 

also in the lower zone of Pennsylvania, but nowhere abundantly. Stropheodonta varistriata 

has not been observed in the central Pennsylvania sections, nor was it recognized farther 

south in Maryland. Leperditias related to if 

not identical with the New Jersey species are 

likewise known in the Favosites zone of Pennsylvania. 

The most marked difference between the 

fauna of the New Jersey Manlius and -that of 

the Favosites zone of Pennsylvania is the 

presence in thelatter of fiv:e Devonian (Coeymans, New Scotland, and Becraft) species, in 

comparison ·with the single form of Devonian 

affinity in the New Jersey beds. A still larger 

number occur at the equivalent horizons in 

Maryland. 

It is shown on page 199 that. the Coeymans 

of central Pennsylvania is the same as the 

Coeymans in New Jersey and New York. The 

equivalency of the basal beds of the Keyser 

and the Decker having been established, it 

follows ·that the Keyser 'is included between 

the same limits as the Decker, Rondout, and· 

Manlius of New Jersey. Considering this fact 

and the faunal and lithologic evidence, the 

equivalency of the formations appears to be 

. as follows: 

Coey:ri:lans =Coeymans. 

!

Manlius. 

_ Keyser = Rondout. 

Decker. 

Tonoloway= Bossardville. 

Possibly the top of the Keyser is somewhat 

younger than the -top of the Manlius of N'ew 

Jersey. It has been sho~ already that there 

is probably an unconformity between the 

Keyser and -the Coeymans. Horizons present 

in Pennsylvania may be missing in New Jersey. 

COJ;tRELATION WITH BEDS IN NEW YORK. 

FORMATIONS EAST OF THE HELDERBERG MOUNTAINS. 

The formations in N e~ York east of the 

Helderberg 'Mountains are continuous with 

those of New Jersey-, the chief change .being 

the development of cement beds and the consequent differentiation of · new formations. 

Clarke and Hartnagel 1 recognize·the following 

succession in eastern New York: · 

-Devonian: 

Coeymans. 

Silurian: 

Manlius. 

Rondout. 

Cobleskill. 

Rosendale. 

Wilbur. 

Binnewater. 

High Falls. 

Shawangup.k. 

Unconformity. 

Ordovician. 

The Coeymans, Manlius, and Rondout are 

identical with the corresponding formations in 

New Jersey. There is a difference of opinion 

as to the equivalency of the Decker. Weller 2 

correlated it with the Cobleskill. Hartnagel,3 

however, proposed to restrict the term to the 

Chonetes· jerseyensis and Ptilodictya zones of 

Weller, and considered them equivalent to the 

Wilbur· and Rosendale. Hartnagel divided 

Weller's Rhynchonella lamellata zone into two 

parts, considering only the upper to be of 

Cobleskill age. If Hartnagel is correct the 

Keyser is equivalent to the Wilbut-Manlius 

interval of eastern New York. 

FORMATIONS WEST OF THE HELDERBERG MOUNTAINS. 

Hartnagel and other authors consider the 

Cobleskill, Rondout, and Manlius of central 

New York equivalent to the formations of the 

same names in the eastern part of the State . 

If this is true the Keyser is equivaient to formations which have been accepted as silurian~ 

The To_noloway horizons would then be considered as entirely lacking in central New York. 

Ulrich 4 proposes a view quite different from 

this generally accepted one-namely, that the 

Cobleskill-Rondout-Manlius interval of eastern 

New York is not the same as that of central 

New York, but that the latter is for the most 

part older. - Ulrich believes that the Manlius 

1 Hartnagel, C. A., Classification of the geologic formations of the _State 

of New York: New York State Mils. Handbook 19, Table 2, 1912. 

2 Weller, Stuart, Paleontology of New Jersey, vol. 3, pp. 74-75, 1903. 

a Hartnagel, C. A., Notes on the Siluric or Ontaric section of eastern 

New York: New York State Mus. Fifty-seventh Ann. Rept., vol. 1, 

pt. 1, p .. 348, 1905. 

• U.S. Geol. Survey Geol. Atlas, Pawpaw-Hancock folio (No. 179), 

1912; Maryland Geol. Survey, Lo:wer Devonian, pp. 115-117, 1913. 
~ 

I 

HELDE~BERG LIMESTONE OF CENTRAL:. 'PENNSYLVANIA. 197 

of the central area contains four divisions, 

which may be named and correlated as follows: 

Manlius of different authors (central area): 

Upper beds ~Manlius of eastern New York. 

Cement beds =Rondoutof eastern New York 

(typical). 

Fossiliferous beds =Cobleskill of eastern New 

York (typical). Same as 

Decker. 

Rondout of central New =Tonoloway of Pennsylvania 

Typical Manlius of) central New York. 

York. and Maryland. 

Cobleskill of central New · 

York. . 

In other words,· the typical Manlius of Ulrich, 

the Rondout, and the Cobleskill of the central 

area are, in Ulrich's opinion, the equivalent of 

the Tonoloway of the south and are Silurian, 

while most of the Manlius of different authors 

of the central area is equivalent to the typical 

Cobleskill (same as the Decker, in Ulrich's 

opinion), the typical Rondout, and the so"'" 

called Manlius of eastern New York and is 

Devonian. There is much to substantiate this 

view in the relations of the Tonoloway fa~na 

as shown in Pennsylvania and as more fully 

represented in Maryland. The close relationship of the central New York Cobleskill and the 

Decker is explained by Ulrich as a recurrence 

of the fauna of the former in thelatter formation. However, the presence of diagnostic 

· Decker forms in the "fossiliferous beds" of the 

. central New York Manlius has not been 

demonstrated, and Ulrich's solution of the 

problem can not be finally accepted until this 

evidence is brought forward, though it does 

offer a very logical way out of the difficulty. 

COEYMANS, NEW SCOTLAND, AND BECRAFT 

ELEMENTS IN THE KEYSER FAUNA. 

The Pennsylvania Keyser as a whole contains 13 species (28 per cent of the species that 

occur elsewhere) which are found in the Coeymans, New Scotland, and Becraft of New York. 

Eleven of these (30 per cent of the species of 

the Chonetes jerseyensis fauna that occur elsewhere) are found in the Chonetes jerseyensis 

zone, and six (38 per cent of the species of the 

Favosites fauna that occur elsewhere) are .found 

in the Favosites helderbergiae var. praecedens 

zone. If only the number of forms common to 

the Keyser and the New York and New Jersey 

Helderberg formations is used as a basis, the 

percentages of Devonian forms rise to 43 per 

cent for the whole Keyser, 34 per cent for the 

103969°--17----3 

(/honetes jerseyensis zone, and 45 per cent for 

the Favosites zone. 

In the Maryland Keyser there are 31 species 

(or 43 per cen tof the forms that occur el~ewhere) 

which also occur in the Coeymans, New Scotland, and Becraft of New York. Of these, 19 

species (30 per cent of the Chonetes jerseyensis 

fauna) _ occur in the'· Chonetes jerseyensis zone 

and 12 species (6Q per cent of the forms that 

occur elsewhere) in the Favosites zone. 

In the Decker of New Jersey the Devonian 

(Coeymans, New Scotland, and Bec:raft) element is very small. Only two such species are . 

cited/ with one that is related to a Devonian 

form -Pholidops ovata, Rhynchospira formosa, 

Stenoschisma declcerensis. The New Jersey 

Rondout, judged by the published lists, has 

no Devonian elements, and the Manlius has a 

single form with Devonian affinities-Stropheodonta varistriata. 

There seems to be thus_ a progressive decrease 

northward in the Devoni'~h aspect of the Keyser and its equivalents. Possibly the Devonian 

fauna invaded the Maryland area first, attained 

a lesser development in Pennsylvania, and did 

not reach New Jersey and New York in large 

numbers until Coeymans time. 

The species of the Chonetes zone that occur 

in the Coeymans, New Scotland, and Becraft 

of New Xork or Have very close relatives there 

are Pholidops. ovata, Orthostrophia strophomenoides, Strophonella leavenworthana var., 

Stenoschisma formosa, Rhynchospira globosa 

var~, Rhynchospira formosa, Nucleospira ventricosa, Nucleospira.· elegans, ~nd Proetus protuberans. The species in the Favosites zone 

are Orbiculoidea discus, Pholidops ovata, Uncinul us nucleolatus, Rensselaeria mutabilis, Nucleospira elega;ns, and Favosites helderbergiae · 

var. praecedens. 

ANALYSIS OF THE. FAUNA. 

The following table summarizes the relations of the species of the Keyser member in · 

Pennsylvania ·to those of other horizons and 

other .areas. The figures given here . are based 

on the table of distribution on pages 200~203. 

The occurrences cited for Maryland, New Jersey, 

and New York are taken from publications of 

the Maryland Geological Survey, New J-ersey 

Geological Survey, and New York State Museum. 

1 Weller, Stuart, Paleontology of New Jersey, vol. 3, p. 74, 1903. 
198 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

Sumrrwry of fauna of Keyser limestone member. 

Keyser 

member. 

Chonetes 

zone. Favosites zone. Transition zone. 

I 

Num- Per Num- Per Num- Per Num- Per 

ber. cent. ber. cent. her. . cent. ber. cent. 

--------:-----------'-·--'------1---1:---1-----.----------- --

Restricted to Pennsylvania .............. ~ . . . . . .. . . . . . . . . . . . . 6 

Species occurring elsewhere ............. ~ ... :-............... 49 

11 

89 

54 100 

Occurr!ng ~n the Tonoloway ~f Pennsylvania ................. ----

4 8 

Occurrmg m both zones of Keyser .•......................... 8 15 

Occurring in Coeymans, etc., of Pennsylvania ................ 2 4 

Ranges of species occurring elsewhere (exclusive of Atrypa _reticularis and Leptaena rhomboidal is) ............... . . . .. : .. 47 

Keyser of Maryland ................................. . ... 38 81 

Chonetes ·zone .................. , .................... 32 68 

Favosites zone ...................................... 11 23 

Decker of New Jersey ......... .' ................... _._ ... 16 34 

Rond-out of New Jersey .................... _ ..... ___ . ___ . 0 ·o 

Manlius of New Jersey ..................... _ ..... ___ ._._. 3 6 

Wilbur of eastern New York ............. _ ..... _._._. __ .. 5 11 

Cobleskill of eastern New York .......... _ . .. _._.~ ___ . . _. 7 15 

Rondout of eastern New York ...... .': ..... _ . _ . _ . _ . ___ . _. 4 9 

Manlius of eastern New York ....... . ... _-_ .. _ . . _. __ __ .... ' 2 4 

Cobleskill of central New York ............ . .-.... ___ ._ ... 5 11 

Rondout of central New York ................ .. ...... .. . ·1 3 6 

Manlius of central New York ............... __ ............ 4 9 

Coeymans and New Scotland .................... _ ....... 13 28 Rang~s of ~pecies occurring in Ma,tkla;nd (exclusive of Atrypa 

1·ecttculans and Leptaena rhombo alts) .......... _ ..... _ ..... 38 

Chonetes zone of the Keyser member ..... : ............... 32 84 

Favosites zone of Keyser member ................ _ . _ . . ... 11 29 

Ranges of species occurring in New Jersey and New York ...... 30 

Decker of New Jersey ......•••. ~ .............. __ ........ 16 53 

Rondout of New Jersey .................. ~ ............... 0 0 

Manlius of New Jersey ........................ _._ . . . _ ... 3 10 

Wilbur of eastern New York .. ~ ....................... . .. 5 17 

Cobleskill of eastern New York ................... _ ..... _. 7 23 

Rondout of eastern New York ........................... 4 13 

Manlius of eastern New York ................ _ ... _. __ .... 2 7 

Cobleskill of central New York .......................... 5 17 

Rondout of central New York ................ ___ ._._ ..... 3 10 

Manlius of central New York :·.: ~ · ................ _ ....... 4 13 

Wilbur to Manlius of eastern New York and New Jersey .. 20 66 

Cobleskill to Manlius of central New York ................ 9 30 

Wilbur to Manlius of New York and New Jersey .......... 21 70 

Coeymans to Becraft of New York ....................... 13 43 

4 

41 

9 

91 

45 '100 

----

4 9, 

8 18 

2 4 

39 ............... ........... 31 80 

4 10 .16 41 

0 0 

3 8 

5 13 

7 18 

4 10 

2 6 

5 13 

3 8 

4 10 

11 30 

34 

31 91 

4 12 

28 

16 57 

0 0 

3 11 

5 18 

7 25 

4 14 

2 7 

5 18 

3 11 

4 14 

20 71 

9 32 

20 71 

10 34 

2 

16 

11 

89 

18 100 ----

0 0 

8 44 

0 0 

16 .............. 

............. ............ 

6 38 

11- 75 

5 31 

0 0 

1 6 

1 6 

2 13 

0 0 

2 13 

1 6 

1 6 

1 6 

5 31 

12- .......... 6 50 

11 92 

11 .............. 

5 45' 

0 0 

1 9 

1 9 

2 18 

0 0 

2 18 

1 9 

1 9 

1 9 

7 64 

3 27 

9 82 

5 45 

0 

12 

12 --

... ~ ......... 

.............. 

............... 

.......... ...... 

I 

0 

100 

100 --

................. 

.................. 

........... 

.......... 

:::::r:::: 

:::::J::::: 

.............. ............... 

.............. .............. 

.............. ............. 

.............. .............. 

............ .. .............. 

.............. ............. 

.............. ............... 

.............. ............. 

............ ... ........ 

............... ... ........... 

.............. ............ 

............... .... .. ....... 

................ .............. 

............... ................. 

------ ................ 

................ 

......... , ...... .............. 

................ ............. 

............. 

............ .............. 

......... ....... .............. 

............ 

............... ............... 

: : ~ ~ ~ :I: : :_: : : ...... , ..... -. 

------ ---··· 

I 

AGE OF Tii:E KEYSER LIMESTONE MEMBER. forms in common with the pre-Keyser beds. 

The Keyser limestone member, as shown If, also, c~:msidering the small number of species 

above, lies betwe~n the Coeymans and beds of common to the Keyser and the Cayuga group 

unqu~stioned Silurian age. It is furthermore of central New York, Ulrich is correct in the 

dearly equivalent to the Keyser of Maryland; view that these species in the Keyser are really 

• which containS a large number of Coeymans, a recurrence, and that the Cayuga of central 

New Scotland, and Becraft forms, and to the New York is mainly older than the supposed 

' Decker, Rondout, and Manlius of New.Jersey equivalent in eastern New York, we have a 

and eastern New York; which contain very few rational explanat~on for the differences beCoeymans, N ~w Scotland, and Becraft species. tween the depo~Its of eastern and central 

If the age of a formation is determined by the · New York commonly grouped as Cayuga and 

. youngest element in the fauna, the Keyser is for ~he more definitely Sillirian aspect of the 

Devonian. If the perc~ntage of an older fauna Cayuga of the central area. How~ver, the 

surviving is taken _as the significant factor, the presence of characteristic Decker fornis in the 

Keyse~ is likewise Devonian, for it has but few "fossiliferous zone" of the Manlius of oentraJ 
HELDERBERG LIMESTONE OF CENTRAL PENNSYLVANIA. 199 

New York (see p. 197) has not yet been demonstrated, and a definite decision must await 

further investigation. For the pr~sent, it 

seems to the writer that the weight of the 

evidence favors the reference of the Keyser to 

the Devonian. 

No physical evidence · of unconformity was 

observed at the base · of the Keyser in any of 

the sections studied, but the sharp faunal 

change and the ordinarily sharp lithologic 

change at that horizon are very suggestive of 

a break in the succession and to that extent 

favor the argument for the Devonian age of the 

Keyser beds. 

COEYMANS LIMESTONE MEMBER. 

The Coeymans member of the Helderberg of 

central Pennsylvania is clearly to be correlated 

_ with the beds at the corresponding horizons in 

Maryland, in New Jersey, and in New York. 

There is a suggestion of an unconformable contact at the base of the member in Maryland, 

and still stronger evidence for it in Pennsylvania, New Jersey, andNewYork. The fauna 

is marked in all the areas by the presence of 

the guide fossil Gypidula coeymanensis. 

Of the ten species identified from the Coeymans of Pennsylvania nine occur in the Coeymans of Maryland and eight in the Coeymans 

of New Jersey and New York. -

NEW SCOTLAND LIMESTONE MEMBER. 

The New Scotland member is closely related 

to the beds at the san:te horizon in Maryland 

and in New Jersey and New York. The 

presence of S pirifer macropleurus and other 

diagnostic forms makes the connection intimate. The species identified from the New 

Scotland of Pennsylvania number fifteen, of 

which thirteen (87 per cent) occur in the New 

Scotland of Maryland and fourteen (93 per 

cent) in the New Scotland of New Jersey and 

New York. -

DISTRIBUTION OF THE FAUNA. 

' The following table gives a d,etailed statement of the occurrence of the fossils found in 

the Tonoloway and Helderberg limestones: 
$ 

0 

~ 

~ 

Distribution of Tonoloway and Helderberg fossils. 

Pennsylvania. 

Helderberg. 

Keyser. 

[R indicates a related form.] 

Maryland. 

Helderberg. 

Keyser. I 

New Jersey. 

Helder-

, berg. 

New York. 

Easte;rn. Central. Helder-

/berg. 

P., 

::l • 

2 eP • b£1 <ll <ll • • • • • • d$ ..0 

c.i § <ll "0 c.i ~ "0 "0 "0 b£1~ 

§ N § § · · § 0 § § § ::l "0 

N ~ N oo ~ >-, N N 00 ~ , 00 ~ ;::l , ...... , 00 ~ ~ 'Ci) 

C'JJ -~ C'JJ § 0 ~ <'J ~ § 8 . ~ 00 § 8 . ;r;l ~ 00 ~ ~ 00 § 8 0 ~ ~ -~ -~ s rll ..9 ~ -~ s w ] .g .;:1 s w ~ ~ .g .;:1 ~ .g .;:1 s w ~ ~ 0 § - ~ ~ ~ g § -~ ~ ~ a5 § ] ~ ~ s :0 §- ] :0 § ] ~ ~ ~ ,8 ~ 8 ~ 8 Z ~ ~ ~ 8 Z A ~ ~ 8 Z ~ 8 ~ ~ 8 ~ ~ 8 Z ~ ~ ------ -- --------------

. _ Coelenterata. , 

t ~a!S~~:~~~~~~:~~~-:-:.:::::: :~: ~ :::: ~ ::: ::::::: :~: ::::::::1:::: :~: :::: ::::._:::: :::_: :::: y: :::::::::::: :::·:::: :::y:: :::::::: 

4. Halysites catenulatus Linne ................ X .... X . . . .. ......... /< ........ X ....... -I· ....... X X ........ X X ...... - !-- .. X ... . 5. Stromatoporoidea, undetermined. . . . . . X x . . . . X . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..... _1 •••••••••••• 

. I. Echinodermata. • l 

I 

6. Sphaeroc_ ystites_ multifasciata HalL •.. ·.. . . . . X .......... -- -.-- . -.. X -·- · --: · ---- ·- ·- -- · · ·-- · --- · · ·- · -- · · -·-- · · · · · · · · · · · · · · · · · -. · · · ·[· ·_ ··1· · · ·1· · · · 7. Crinoidea, undetermined ••.•.•••.......... x ........................... _ ..................... 1

•••• •••• •••• •••• ••••• •••• •••• ••• • ••••••••••••• •••••• 

I 

Vermes. _ 

~: ~~~:~~~-~~~:~:::·:::::::::::::: •• 

1 

.. -~- :::: -~- ::::::::::::::::::::::::::::::.:. ::::::: ::: ' ::::::::::::1:::: ~- ::::::: :::l::::l:::r:r:: 'I I - ' 

Molluscoidea .• I 

10. Bryozoa, undetermined ••.••..... .- .... X 'I X I X X ... ·--1···· ... .l ....... ·. .... ... . .... , .............. _ .... _ ...· .... 1····1····1·-··.····i····j····r--·.·· 11. Lingula ~p ........ ~ .· ...... ~ ............... , . . . . . . . . X . . . . ... -....... -... · .. · --. · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·_ ·· · · · · · · ~ · · · · · · · · · · · · · · · · 

;~~ ;~~~:~%1f3f1.~tttr :::_1;~; -~; -~- ;:; .:::;;: -~; -~- :;;: :::: ;~. :;; ;;:; :::: -~; ;;;;,;;;; ;:;; >::;;: :::; :-::1::;; ::::-:: ;:;: 

16. Orthostrophia strophomenoides (Hall).. .. .. X .. .. .. .. .. .. .. .. .. .. X .. .. .. .. X .. · · ...... · .. · X · .. ·I· · · · · --- · · · · · · · _. · · · · · · · ·. -~ · · · X · · · · · '· · 17. Dalman ella concinna (Hall) ........ ~ . .. .. .. X X .... j .... 1 

.. ~. .. .. X ? .. .. .. .. .. . . ......................................................... .. 

18.-Dalmap.ella clarki Maynard ....... · .. _, ..... X .... / .... J .... 1 ...... ~. X ..... ~.. .. .. .. .. . ...... _. · ... , ... ·:-- . ........ , ............................... . 

t-O 

0 

0 

(/)_ 

P4 

0 

~ 

H 

tr_j 

!:0 

Q 

0 

z 

q 

~ 

~ 0 

z 

<fl· 

f-3 

0 

Q 

tr_j 

z 

tr_j 

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Q 

tr_j 

0 

t"" 

0 

Q 

---~ . 1--' 

~ 

~ 
~ ~ 

'· \.\ 

• ~ , -----.. a • a a a ; ; 5 

19. Dalmanellacf,_. D. perelegans (Hall) ........ ·[ X 1- --- ---- ... . .................. ' .... · ... .' .... ! •.... ···· 1. ···· ····!···· .. : ..... ···· ····~···· .............. . 20. Dalmanella perelegans (Hall) .................. 1 

........ X X ............ X X ................ , X ............................ X X ....... . 

21. Dalmanellasp .......................... . ..... 

1 

..... ~ .................. _ .................. ' ......... ... ... .1 ...................................•.... 

22. Rhipidomellaemarginata (Hall) ............ X ....................... X ................ 1.... ... .._ ... _ .................. 

1 

.... 

1 

................... . 

23. Rhipidomellaoblata(Hall) ..................... , ............ X ...... ...... X X ....... 1 .... X 'X ............................ X X ....... . 

24. Leptaenarhomboidalis (Wilckens) ......... X 1

1 

X .... X X .... X .. .. X X X ....... X X X X ........ X ........ X X X X 

~~: ~~~~~~~~~~~~b~~t;j~f~~?i)·.-.-.-.-.-.~::::: :::::::::::::::: 9 :::::::::::::::: -~- 9 ....... ·::: ::: "x' :::::::::::::::::::::::::::: -~- 9 :::::::: 

27; Stropheodonta planulata (Hall) ........................ X ................ X X .. . . . . . .. . X ............................... X ......... .. 

28. Stropheodonta bipartita (Hall) ............ X X ........ 1 .. _ .. X X ............ X .... .. . . .. . . ~ R R R .. . . R . ------- --- --- · -· ·--· · 

~~: ~~~~~~~~~~~~t;:Ji~~i~i~cii~il):::.-.·_-.-_~: :::: ·x· ·x·l:::: :::·,·::: :::: ·x· :::::::::::::::::::. _::: ::: :::::::::::::: ::::::::::::::::::: :::· ::::::: 

31. Strophonellaleavenworthana(Hall) .................. . . X . ...... . 1 ........ : X X .. . . ·:-- ........ X ........ --~ ---- ---- ---- ........ X ....... . 32. Strophonella leavenw~n't~ana (Hall) var. . . . . X .... 1

• • • • R ... .... 

1

. . . . . . . . R R . . . . . . . . . . . . . . . . R . . . . . . . . . . . . . ... --·1· ---I-------- R -- · · --· 33. Strophonella punctuhfem (Conrad)........................ X .......... , . X X ... ......... X X ...................... 1 

•••• X X ...... -. 34. Schuchertella prolifica Schuchert ........... I ........ i X . . . . . . . . . . . . . . X .. .. . . . . .. .. .. .. . .. . . .. . .. .. . . . . .. .. . . . , .. .. . .. ... ".. .. . . . .. . ..... .. 35. Schuchertellawoolwo;th_ana (Hall) ........ !....... .. . X X ............ 1 X X ............ X X .... ·....... .. . .. . . ...... X X ... : ... 

36. Schuchertella deckerenBis (Weller) .•...... ·I X . . . . ... --- .. ·l·. -X ---· · · · · · · · · X · · · · · · · · · · · · · · · · · · · -1-· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · 

~: ~~~~1~~~!f::~~=~t ~ ~ ~. ~ ~. : :. ~ ~: ~. ~ ~; : ~ : : . ~. : ~ : .: ~ ~ : ~ : :: : ~ ~ ~ : : : . ~: : :. ~ ) : ~ : :.. . : ~ ~ ~ ~ : : : : . ~ ~ . ~.:: : : ~: ~ ~ ~: !~: 8~~~~r:,~~~·:e1~:h~~~USH~li ~d· ···· ·r · ··· ···· x I · ···· I. · ···· ···· ···· ···· ···· ···· ···· ···· ···· ··· ·· ···· ···· ···· ··· ··· x 

43. G~~iJ~1~ ~~~Y~~~~;{si~ ·s~h~~h.~~i::::: :::: ::: J:: ::: · x · . ~. :::: :::: :::: · x · . ~. :::: :::: :::: · x · :::: ::: · ·::: :::: :::: ::: :::: :::: 9 x :: J::: 

44. Gypidula coeymanensis prognostica ; . [ . 

:~: ~='F=:·!i:~~~:~:\~~i~~~;: __ :.:: : :. ~ ::: t : .. :: : : : ~ ---- ::: : : :~: :: .:: :. ~: y :: ::::::: ::: : : : ::: :~: :~ :: :::: 47. Camarotoechia lamellata HalL ........ X X ................ X X ....... x· ...... I ....... X X X .... X X ........... T ..... .. 48. Camarotoechia litchfieldensis Schuchert X X i X .. .. .. .. .. .. X X ... ! .. .. X ... , . . . . .. .. .. X X X ........................ ...... .. 49. Camarotoechia sp ................ · ... : ....... 1 

•••••• _ •••••••••••••••• _I _... • _. ' .... • • • • •• I.... ___ . . . . . . . . ........... _ .......................... . 50. Uncinulus nucleolatus (Hall)......... . .... :.. . . . . X ........... I X X X X .. . .. ... _ X .. .. . .. .. .

1

.... . . . . . . . . . . . . . . . . . . . . X .. ...... , 51. U ncinulus keyserensis Schuchert. .·... .. . _ . .. . ? X . . . .. . .. .. _ . _ X .... i . . . . . . . .. . . .. .. . . . . . . . .. .. ....... _ ....... : ..... _ .. _, ..... ~ .... .. 

52. Uncinulus convexorus Maynard? .......... X ..... - ------ ---- X ------ - ---------- · ·--- · · ·-- · ·- · · ·-- · ·---- · ·---- .. · .. l .. · 53. Unc~nu!us mutab~lis Hall var. . . . . . . . . . . . . . . . . . X --- --- --. - --- -- -· - --- ---- --- ---- --· -1--· - -· · ---- : · · · -· -· · -· · · · · · · · --1- · · · · · · ·r· · · · 

~t E~~i~~~~: ~~;r~~~!~~~aR~~~i~i~:::~:: :::: ·x .::: -~ .:::::: ::: ... .. :::::: :::::::.::::::::::: :::::::::::::::: ::::r:::: ::::·:::: :::::::: 

!~:I~E~!~~~~(~¥L_:._:_::: ::::\\:{1/Y:: ·r; ~: < J<! />;x::: >T:///1/II ;>Y<T: ~~: ~~~::~~:~~~: (~~~~h~)e;~~:~it~. s~il~~ ......... : ... ·I X ..... .. .... ' ..... -.. . .. .. . . .. . . . . . . .. .. .. . . . . . . . . .. . . .. ............................... .. 

63. R~~!~\~~;i~-~p::::::::::::::::::::::: :::::::: -~- -~.1:::: :::: :::· ::: -~- :::::::::: ·::: :::::::::::::::::::: ::::::::::::::: ::: ::::::::: ::::::: 

64. Atrypa reticularis (Linne) ...... ~ . . . . . . . . . X X .... I X X . . . X ... - X X X . . . . . . . . X . . . . X X ....... I X ---- . - . - X X - -- . -- . 

~~: ~~i~f!.~~~~~~e~~~~(c~;;r~·d·)·.·_-_-_::::: :::::::. :::: __ ? __ 1:::: ·x· ::: ··-- ---- ::: ·x· :::· :·:::·:::: ·x· -x· :::1:: ::::::::::::::::::::::: ·x -~- :::: 

s . . 1 11 H ll i I ? . I ~ I i X ~~: s~i~i~~~ ~~d~~~s ~~~L _a __ ~ : : ~ ·_ -_ · _· .-. ·_ -_ : : : : : -x -·: : : :I: : : : .. : .. ~ . : : : x : : : . ~ . : : : : : : : : : : : : : : : : . ~ . : : : : : : : : : : : : : : : : : : : : : : : ·: : : : . ~ . . . . : : : : : : : : 

69. S_pirifer modestus plicatus Maynard .. _ ..... ) X 1- ... I, ... :. .. . . . . .. . X .. . . .... : . ... J ....... J .................. J .......... -,-.: ......... :--1-- .. 

Ill 

.t;:j 

~ 

t>:l 

~ 

~ 

'"" 

~ 

t>:l 

U1 

H 

0 

~ 

t>:l 

0 

1-:;j 

0 

t>:l 

~ 

~ > 

~ 

"'d 

t>:l 

~ 

z 

U1 

~ 

E 

z 

~ '"" 

1:--!) 

0 

~ 
>. 

~ 

"* >=l 

0 

~ 

-

1. 

Mollu.scoidea--Continued. 

Distribution of Tonoloway and Helderberg fossils--Continued. 

Pennsylvania. 

· Helderberg. 

Keyser. 

tJ5 

Q.) 

>=l Q.) ~ >=l 0 >=l § 0 !>< 0 !>< >=l !>< 00 ~ 

<¢ .s ~ ~ 0 

~ ....., <:) 

...... -~ w. ~ rn 

§ 0 0 G' ~ 

~ "" 8. ~ 0 a:> 

Q z - - -- --

(R indicates a related form.] 

Maryland. 

Helderberg. 

Keyser. 

Q.) 

>=l · >, 0 

~ !>< 

<¢ 

.;:$ ..9 

§ ~ 0 0 

~ ~ 

Q.) .e >=l 

0 @ !>< 

<¢ 00' ~ § 0 .;:$ <:) ..,.. 

•<¢ s w. ~ ,..!:o:l 0 G' "" <:) 

~ ·o a:> 

Q z A 

New Jersey. 

~ 00 6 -~ ] § ~ ~ 

Helderberg. 

~ 

§ 00 

§ ~ <:) 

~ w. 

~ 0 a:> 

Q z 

New York. 

Eastern. Central. 

- .;..;; - ~ 

"I~ - 6 00 ~ ;::1 00 

-~ 0 ;::; Q.l "'0 Q.l "'0 -~ 

.,::; ..a -.g >=l § ~ § § ~ Q ~ ~ Q ~ ~ 

Helderberg. 

.e 

>=l - c6 00 ~ >=l 0 c:l <:) 

s w. 

G' ~ 0 a:> 

Q z 

A 

:::; 

tb 

0 

Q.l 

~ 

c6 

:::; 

~ ~ "'0 

~ a) 

Q ~ 

] Q.l 

> 0 a:> ..a ~ -< 

~~: ~~~~:~~~~~::luE:~i~~----~:::::::::: :::: ·Q ::::::::::::1:::: ·ii- Q :::::::::::: -ii- :::: ·x· -~- :::::::: ::::1·><· :::: ::~: ·x· ·x· :::::::::::::::: 

72. Spirifer vanuxemi prognosticus Swartz. . . . . X X X . . . . . . . . . . . . X X . . . . . . . . R .... .. ... , ... . .......... 

1 

........... - - - - - .. .. ............... . 

~!~ li~E~;~~~~~~::::::::·: : ~ \\~:~: ~:·: :~· :~: :~: < ~-- :< / ~~~: ~ ::::: )· ). ~-~~ ~t: :~. -~- .:~· :::: _.·: :~. :::::::: 

77. Rhynchospira globosa (Hall) var. . . . . . X X . . . . . . . . . . . . . . . . R X ... _ .. . . . R - X ................... . .... 1. . . . . . . . . . . . . . . . . . . . R R ....... . 

~~: ~~~~~~:~~~: f~~:R~~~ci!~ ·_ -_ -_ -_ -_ ~: ~ : : : : : : : : 9 : : : : : : : · -: : : : : : : : : ~ ~ -: : : : : : : : : : : : -~ . : : : -: : : : -~- : : : : : : : : ~ : : : :-: : ·: : : : : : : : ~ : : : : : : : : : : : : -~ . : : : : : : : : 

80. Rhynchospira sp ...................... . . . . . . . . . . . . . . . . . . . . . . . . ........ . _. . . . . . . . . . . . . ............... -...... . ........... ___ .................. ~ .. . 81. Nucleospira ventricosa (Hall).......... . . . X . . . . ? X . . . . X X . . . . . . . . . . . X X .. . ................. -.-- . . . . . . . . X ....... . 

ll-~1~1l~~t~fi~/.:.~--~;: 88. Whitfieldella cf. W. nucleolata HalL .. ,· . . . :}:::·!!:]:/:x:: 

. X . . . . X . . . . . . . . X. 

: ~:!}Y X : . . . . . . . . . ~:!!! . . X l! .. . ........... :/!!Y!!<!!!!><:r!<Y:~:t:-J: --- . . . . X X . . . . X X .... --- ... -- -- .. 

1

.---

:~: s:~::~!~~~;:t~:~~~~~~::::::::: :::: :~: 1 ~: :~: : :::: :::: :~ ~: : ::: :1 ::::::: ::: :::::::::::::: :::: ::::1::: ·::: :.::::::::::::::::::: 

Mollusca. · 

~~: ¥~!~~E~t~~,;~t~!d~i~~1i?_·::_-_-.-::: :J. ~- I Q 1::::1. -I- ~ -I·~ -1::::1::::1::::,:.:::1::::1::: :J::: :1::::1::::1::::1::::1:: :·:1::: 1 :::1::: :r::: :r::: :r::: :r::: :r: :: :r·- >< 

94. Bellerophon auriculatus? Hall. . . . . . . . . . . . X ........ -. -. . ....... I R · .. : . ............ J ...••..•...•..•••.••••••••• . • • • X ... ' ....... -... -. -... - - -. 

t:..:> 

0 

. «:-:> 

(]). 

Ill 

0 

~ !:tl 

0 

0 

':2l 

q 

~ 

~ 0 

z 

(]). 

t-3 

0 

Q 

l";j 

':2l 

l";j 

~ 

t"" 

C:l 

l";j 

0 

t"" 

0 

C:l 

"'~ 

.... 

~ 

::r 
.. • I ' . . . . 

. . . . 

: : : :I: : : :' : : : :' : : : :I: : : :I: : : :I : : : :II : : : :I: : : : 1: : : :I: : : :I : : : :I: : : :I: : : :' : : : :I: : : :I: : : :I: : : : : : : :I: : : :. : : : ~I: : : :. : : : :I : : : :I: : : : ............ ............ ...................... .. .... ............ ···.-!·· ·· ····.··· · ........ ---· -------- ···· ------------X ---· ---· -··· -------- .... -------· ---- ---· ---· -·-- .... -··· -- --X ---·--·······---

95. Ectomariasp ......... ............. . .. ... . X 

96. Coe1idium pennsy1vanicum Reeside ... . _ _ X 

97. Coelidium da1matiae Reeside ............ _ X 

98. Ectomaria minuta (Hall) .............. X X 

IIi ~~~ii~l]r:::·::::: :::: -~- i~ii :~~iii! !!:~ iii: ~J: II :::: ~::: :::: :::: !!!! :~: iiii :::::::: i~\i !x: !~! :::: !~! :~: ~:;: :::: :~~ :~~~ 107. Tentacuhtesgyracanthus(Eaton) ......... X -- X --- -~- --- X X X ............ 1 .... X .. . . ---· -- ·· --·- .... X ........ X .. . ..... .. .. ··· · 

. m~ lSE£t F~:~~~HH:~~~ ~ : : : ~ : · ; · : ~ ~ ~ : ~ : ~ ~ ~ r ~ : ~ ~ ~ ~ ~ ~ J ~ ~ . : : ~ : · : ~ : : : ~ ~ : : : : ~ j ~ ~ ~ : : : ~ ~ : : ~ ~ ~ : ~ ~ : : ~ : : ~ : ~ : : : ~ : : ~ ~ ::: ~ ~ ~ : ~ : ~ :. ~ ~ : t: ~ · 

112. 113. Goldius ProetuspachydermatusBarrett ba:=~~:;). · · · · · · · ........... · · · · · · · · · · X X ·---- · · · · ....•...••.. · --1· · --1-- · ····- ----~-·-·I··· X --·· -I-··· ,--·•---· ···-I-·· X ·I·-------- '· -I ·I···· ---· ··-·,· ---· ---- ··-I-·· -· ·-

T·-- I-·.··.··· -----I-··· ···-I-··· · · · · X I.·· ·I···· 

1

---- ... T ... ----1---- 1---- --· · 

gg: ~~~:~~: ~;~~~~~r~-~s- ~~1_1 ~: : : : : : : : : : : : : : : : . ~. : : : : : : :: : : : : : : : : :: : : : : : : : : : : : : : : _ ~ _ : : : ~ : : : : : : : : _ ~ _ : : : :I: : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : _ ~ _ :: : : : : : : 

116. Cyphaspis. cf.C.minuscu1us(Hall)~--- .... X ---· .................................... ---- ........ ·:-- .. . ......... --.-- ............ .. .......... X 

117. Ca1ymenecamerataConrad ............... X X ............ X X ............ X -------- ---- .. . . X X ---- -·-- X ---- ................ ----

~~g: ~~~~inif~::~~~~~-(a~~~~)::::::::: :::: --?- :::::::: -~- ~ ::::-it-:::::::: · :::::::::::::::: -~- :::: :::::::::::::::::::::::::::: ·x· :::: ~ 120. Da1manitesp1europtyx(Green) ... _ ...................... X .......... ' .. X 1 

X .... -··- ---- X X ........ . .......... _ ...... . ... . .. X .... X 

~~~: r:~~rdi~!:ss~::::::·: :::::::::::: ::: ·x· ·x·.:::: ·x· :::::::: ·x· ·x· ·x· ::::i.:: .:: ·x·l·.x· ·x· :::::::: ::::::::::::::::::::::::::::::::::::::::: 

123. Ostracoda, undetermined .. .. .. . ....... :» X X X X X ····( -- ---- ----1---- ---- ... : ···· ------- ---- ----· -------- ·--· ··-- ·--· ·---- ····j·--- ---· 

p:j 

i:?=j 

b 

i:?=j 

~ 

b:1 

i:?=j 

~ 

~ 

~ i:?=j 

00 

H 

0 

z 

i:?=j 

0 

l'%j 

a 

i:?=j 

z 

H 

~ 

> t"" 

1-d 

1;:1 

z 

z 

m 

~ 

t"" 

< 

> '!2-l 

..... 

?". 

1:>0 

0 

~ 
204 SHORTER CON:TR.JBUTIONS TO GENERAL GEOLOGY, 1917.._, 

SUMMARY. LOCAL SECTJONS OF THE TONOLOWAY AND 

HELDERBERG LIMESTONES. 

- - The facts presented in the foregoing pages 

lead to the following conclusions: In the folloWing discussion the figures follow1. The Tonoloway limestone and the Keyser, ing the name of a fossil indicate the stratiCoeymans, and New Scotland members of the graphic distance in feet at which the form 

Helderberg limestone may be traced from occurs above the base of the member containMaryland through central Pe:p_nsylvania with ing it. · The distances in the Tonoloway formatheir respective characteristic lithology and tion are given by negative figures which indifaunas, and the essential equivalents of all are cate the stratigraphic distance -in feet ·below 

to be found in New Jersey and eastern New the base of the Keyser at which the form occurs. 

York. The letters a and c mean abundant and com2. The _ equivalents of the Tonoloway and mon, respectively. 

Keyser in central New York are in doubt 

h h 

' LINCOLN -AND FIFTEENTH STREETS, TYRONE. 

t oug u1rich's view (p.l97) is very suggestive 

and may prove to be correct. The ex;posure represented by the subjoined 

3. The beds referred to the. Tonoloway at section begins just behind the house on the 

Tyrone, Pa., differ- from. those found in that southwest corner of Lincoln and Fifteenth 

formation elsewhere, and the sharpness of the streets, Tyrone. It extends along - a small 

supposed Keyser-Tonoloway contact suggests creek known locally as Sink Creek and as the -

an unconformity. Further work may show dip is high, comprises within a short ho~izontal that the beds immediately in contact with the distance an excellent section of part of the 

Keyser at this point are of Wills Creek age. Tonoloway formation and the Keyser, Coey4. The Keyser member decreases in thick- mans, and New Scotland limestones. 

11ess northward from Maryland. - .The· Tonoloway-Keyser contact is marked by 

5. The Devonian elements in the fauna ap- the_ abrupt appearance of the Chonetes jerseyparently decrease from Maryland to New Jersey ensts fauna and by the change in lithology from 

and New York. the light-colored limestones of- the Tonoloway 

6. The Tyrone and ·Grovania sections of the formation to the darker beds of the Keyser, 

Keyser limestone resemble each other _and though parts. of the Keyser are unusually light 

.differ very materially from the remaining sec- colored and resemble the Tonoloway. The 

tion~ in Pennsylvania and from the 1faryland Keyser-Coeymans contact is shown by the 

sectiOns. abrupt change fron1 the impure platy fine7. The Tonoloway limestone ·and the Keyser grained li1nestone of the uppern1ost Keyser to 

member of the Helderberg limestone in Mary- the coarsely crystalline limestone of the Coeylan~ and ~ennsylvania and their probable mans and by the presence of the characteristic 

eqmvalents In New Jersey were possibly laid Coeymans fauna. The Coeymans-New Scot- ._ 

down in a b_asin which was connected with land contact is not very sharply defined lithothe open sea in the Maryland region and was _ logically; In the section it is placed arbitrarily • 

progressively restricted northward and east- beneath the lowest beds containing Spirifer 

ward to New Jersey. There may have been also macropleurus. It is probable that at least part 

a second basin which included the Tyrone and of the concealed unit at the top of the section 

Grovania regions. Conditions in this second is of New Scotland age. , ~ basin were different and favored the growth of Schuchert} in discussing the Lower Devonian 

c~rals and stromatoporoids, owing to a greater of this locality, refers 115 feet of the sectio-n to 

distance from the source of sediments or to the the Keyser limestone, stating that the "cystid _ 

presence of some sort of barrier on the east. member" is present at the base and several 

8. The suggestion of an unconformity at the Stromatopora-bearing beds toward the top. 

top of the Keyser in Maryland is borne out in The beds beneath the Keyser he referred to the 

Pennsylvania by the variations in thickness of Cayuga; the beds overlying the Keyser he conthe member and the presence of arenaceous 1 Schuchert, Charles, Silurian formations in so~theastern New York 

material at the base of the Co-eymans-.- New Jersey, and Pennsylvania: Geol. Soc. America Bun.,--\Tol. 27 p. 552, 1916. - ' ' 
• 

• 

HELDERBERG LIMESTONE OF CENTRAL PENNSYLVANIA. 205 

siders Oriskany and believes therefore that the 

Coeymans, New Scotland, and Becraft are abs.ent. However, as the following description 

shows, both the Coeymans and New Scotland 

are rep res en ted. 

Section at Lincoln and Fifteenth streets, 1'yrone. 

Concealed; scattered outcrops of darkgray and brown fissile shale; a few 

bands of impure limestone. 

Helderberg limestone: 

New Scotland limestone member: 

Limestone, medium bedded (1 

foot), fine grained, light gray; 

contains chert lentils and shale 

laminoo. Leptaena rhomboidalis, 

Stropheodonta becki, Strophonella punctulifera, Schuchertella 

woolworthana, Eatonia medialis, 

Spirifer perlamellusus,Dalmanella sp., Camarotoechia sp., 9.9 .. Shale; weathers brown .......... . 

Limestone, impure, fine grained, 

thin bedded, light gray, in courses 8 inches thick, with 

shale partings ..... ; ......... . 

Limestone, shaly, weathered ... . Limestone, massive, heavy bedded, coarse grained, crystalline, gray.; much interbedded 

chert. Lingula sp., Orbiculoidea sp., Dalmanella perelegans, 

Rhipidomella oblata, · Leptaena 

rhomboidal is, Stropheodonta plamllata?, Schuchertella wool-

'lvorthana (a), Uncinulus nucleolatus, Eatonia mediai'is, Spirifer 

cyclopterus, Anoplotheca con- cava, Meristella sp., Camarotoechia sp., Orthocerassp., Phacops logani, Dalmanites micrurus, Pelecypoda, Bryozoa, 3.2; 

Spirifer nwcropleurus loose on surface ...................... _ . 

Coeymans limestone member: 

Limestone, very impure, shaly, 

yellowish. · Atrypa reticularis, 

Spirifer sp., Dalmanites sp., 

Bryozoa, 5.5 .................. . Limestone, somewhat weathered, 

lightgray, coarsely crystalline; 

line of chert nodules (2 by 10 

inches) near the top. Dalmanella perelegans, Stropheodonta . arata, Gypidula coeymanensis, 

Atrypa reticularis, Spirifer cf. 

S. perlamellosus, Dalmanites 

sp ..... -.................. -- . Limestone, massive, coarsely 

crystalline, dark .......... -.- __ _ 

. Total 

Thick- thick- ness. nes~>. 

Feet. 

4.4 

1.4 

2.6 

.8 

4.8 

14.0 

3.8 

2.0 

2. 5 

8. 3 

Feet. 

14.0 

9.6 

8.2 

5. 6 

4.8 

8. 3 

4. 5 

2. 5 

Section at Lincoln and Fifteenth streets, Tyrone-Contd. 

Total 

Thick- thickness. ness. 

~----~------------~--------- ----------

Helderberg limestone-Continued. 

Keyser limestone member: 

Limestone, single bed, light gray, 

fine grained, impure ......... . 

Limestone, very shaly, light 

gray ....... --- ......... ------ Limestone, light gray, fine 

grained, platy ............ ----. Shale brown, weathered ... ·_ .... Lime~tone, light gray, fine 

grained, platy ............... . Shale, brown, weathered .... _ . _. Limestone, impure, brownish 

gray, · very platy; breaks into 

sheets half an: inch thick. . Pelecypoda ................... - Limestone, pure, fi:o.e grained, 

brownish gray; in two beds separated by brown shale; has 

conchoidal fracture ........... . Limestone, shaly, banded, dark 

gray; contains carbonaceous 

films. Leperditia sp., 69.8 .. __ _ Limestone, composed entirely 

of stromatoporoids; Leperditia 

sp., 66.8 ............. -.- ... . -- Limestone, shaly, yellowish 

gray. Scattered heads of 

stromatoporoids at 67 .0 ...... . Limestone, composed entirely 

of stromatoporoids; under sur- face very irregular .. _____ . ___ . 

Shale, brown, weathered ... _ .... 

Limestone, composed entirely 

of stromatoporoids and corals; 

under surface irregular ....... . 

Limestone, buff, fine grained, shal y ........... _ . _ ... ___ ... __ 

Limestone, extremely massive, 

composed entirely of corals, 

Bryozoa, and stromatopo.: 

roids ....................... . 

Limestone, with profusion of cor- als and stromatoporoids._ ... __ 

Shale . ............... _ .......... . 

Limestone, coarsely crystalline, 

gray· ..... --- ·--·--------------. Limestone, coarsely crystalline, 

gray. ' Scatte!ed stromatoporoids, Favos'ltes sp., A ulopora sp., Calymene camerata, 

36.8 ... -... -.-.---. ~ .. -- .. --- Limestone, coarsely crystalline, 

gray. Dplmanella concinna, 

Calymene camerata, 34.5; Dalmanella clarki, Rhipidomella 

emarginata?, 33.5 ............. . Limestone, massive, coarsely 

crystalline. Clado'pora rectiline':lta, Halysites catenulatus 

(a), Aulopora sr., Favosites 

sp., stromatoporoids .......... . Limestone, thin bedded (1 to 6 

6 inches), crystalline, li~ht 

gray ............... ~ -- - --- -- - Limestone, massive, coarse grained, light gray ........... . 

Feet. 

1. 1 

1.8 

.8 

2. 9 

1.1 

2.0 

4.6 

2. 7 

1.5 

2. 3 

2. 0 

3.2 

.4 

5. 9 

1.5 

9. 4 

6.0 

.6 

1.0 

3.0 

3.5 

7.7 

3.5 

5.0 

Feet. 

88.3 

87.2 

85.4 

84.6 

81. 7 

80.6 

78.6 

74.0 

71.3 

69.8 

67.5 

65.5 

62.3 

61.9 

56.0 

54.5 

45. 1 

39.1 

38.5 

37.5 

34.5 

31.0 

23.3 

19.8 
206 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, l917 . 

. Section at Lincoln and Fifteenth streets, Tyrone-Contd. 

Helderberg limestone-Continued. 

Keyser limestone member-Contd. 

Limestone, thin bedded, gray, 

and shale. Cladopora recttlineata, Orthostrophw strophomenoides, Leptaena rhomboidalis, 

Stenoschisma formosa, Atrypa 

recticular·is, Spirifer octocostatus, N_ucleospira elegp,ns?, Rhynchosptra sp., Orthoceras sp ..... . Limestone, brownish gray · to -· buff, in single bed standing 

out as a ridge; coarse, crinoidal. 

Bryozoa, 9.5 ............ , ..... . Limestone, thin bedded, coarse, 

gray- - - - - - - -. -- -. - - - --- - ~- . - - Shale .......................... . Limestone, buff, massive, coarse grained, crystalline .......... . Limestone, . brownish gray, single bed. Fragments of fossils on sutface ................... . Limestone, thin . bedded, buff; 

drab on fresh fracture. Dalmanella coiwinna, Stropheodonta · bipattita, Schuchertella 

deckerens'/,8, Camarotoechia litchfieldensis, Atrypa reticularis, 

S pirifer eriensis?, Meristella sp. , Bryozoa, _ 0. 8 ................. . 

Tonoloway limestone: 

Limestone, massive, buff ............ . Limestone,· massive, fine grained, 

buff, cherty ...................... . Limestone, massive, fine grained, buff, banded ............. ......... . Limestone, fissile, banded, buff; drab on fresh fracture .......... : ..... __ Shale, buff, calcareous, contorted and 

in places apparently brecciated ._ . - Shale, weathered, brown, earthy ..... Limestone, massive,· fine .grained; 

weathered surface light gray, fresh 

fracture drab; banded; contains some thin chert lentils ............. . Limestone, platy, banded, fine 

grained, light gray ............... . Limestone, platy, laminated, fine 

grained, buff. Leperditia sp., 

-41.0 ..... -...................... . Limestone, buff to light brown, platy; 

much_geodal calcite in small crystals ............................. . Limestone, fissile, light gray ........ . Concealed; probably platy limestone. 

Limestone, light gray, platy, impure. 

Limestone, light gray in solid bed; 

platy fracture ..................... . Limestone, platy, fine grained, buff .. Concealed; brown shale in part ..... . Limestone, platy,. buff ............... . Shale, calcareous, and fine siliceous 

oolite(?); weathered · surface ferniginous, brown; bedding irregular .. Limestone, blocky, fine grained, buff. 

Shale, weathered brown ......•...... 

Thick- T?tal ness. thickness. 

Feet. Feet 

1.5 14.8 

3.9 13.3 

.6 9.4 

.4 8.8 

3.6 8.4 

2.5 5.8 

2.3 2. 3 

88.3 

2.0 -2.0 

1.4 -3.4 

> 6. 4 -9. 8 

11. 7 -21.5 

7.8 -29.3 

1.0 -30.3 

6. 7 -37.0 

2.3 39. 3 

-9 -40.2 

1.3 ;_41. 5 

2.3 -43.8 . 

4.0 -47.8 

1.0 -48.8 

3.3 -52.1 

4.0 -56.1 

15.0 -71.1 

2.5 ~73. 6 

2.4 -76.0 

1.3 -77.3 

2.5 -79.8 

Section at Lin.coln and Fifteenth streets, Tyrone-Contd. 

Tonoloway limestone-Continued. 

Limestone, platy, fine grained, buff .. Shale, calcareous, much weathered; some fine-grained sandy (?) layers 

(siliceous oolite?) stand out ....... . Shale, calcareous, buff to light gray .. . Limestone, fairly pure, fine grained, 

buff, blocky fracture .............. . Limestone, buff, platy, laminated in· part ... : ............. --.--- ........ · Limesto:p.e, shaly, platy, yellowish; 

many geodal calcite masses with 

large fine crystals ................ . 

· Total 

Thick- thick- ness. ness. 

Feet. Feet. 

2. 3 -82.1 

10.3 -:-92.4 

1.5 -93.9 

4.0 -97.9 

6.3 -104.2 

5.0 -109.2 

i 109.2 

This section is noteworthy in several respects: The lithology of the Tonoloway portion 

is unlike that of any other save the adjacent 

Pennsylvania Avenue section. It resembles, 

in the light color and fine texture, parts of the 

·wills Creek of Maryland rather than the Tonoloway. There -is not sufficient ground for referring the beds to the WiHs Creek, however, for 

they are almost barren of fossils (even Leperditia is very scarce), andit would be necessary 

to assume a hiatus, for which there is little evidence. The Chonetes jerseyensis zone of the 

Keyser is well defined faunally, but the nodular 

character so prominent elsewhere _is lacking 

here. The_presence of an abundance of corals 

and stromatoporoids, notably Oladopora rectilineata and Halysites catenulatus ,_ and the 

absence of the characteristic brachiopods of 

the . Favosites zone-Rensselaeria, Meristella, 

Uncinulus, etc.-as well as of Tentaculites gyracanthus, are also remarkable features of this 

section. 

PENNSYLVANIA AVENUE, TYRONE. 

The section given below was measured at the 

north end of Pennsylvania Avenue, Tyrone, 

just north of the West Virginia . Pulp & Paper 

Co.'s plant.- Its base is in a small quarry 200 

feet northeast of the concrete bridge over Bald 

Eagle Creek, parallel to which the exposure 

extends westward to the road cut through it. 

The rocks·. exposed comprise 325 feet ·of the 

Tonoloway, the entire Keyser, and the base of 

the Coeymans. The lower part· of the Tonoloway exposure is much-crumpled, and the thick-
HELDERBERG LIMESTONE OF CENTRAL PENNSYLVANIA. - 207 

nesses given are therefore only approximate. 

The upper part of the Tonoloway and the overlying beds are overturned about 21°. There 

are no signs of faulting in the exposure itself, 

but the Keyser is repeated about 100 yards to 

the west by a concealed fault. 

The Tonoloway-Keyser contact is exceedingly sharp. The light-colored barren beds 

referred to the Tonoloway are _succeeded with-

-out any transition by a thin shale carrying 

Keyser fossils, and this in turn is succeeded by 

an impure gray ''bastard '' limestone containing 

many characteristic species. The lithology of 

the Tonoloway here, as in the adjacent section 

at Lincoln and Fifteenth streets, is unlike that 

in any of the other exposures studied by the 

writer. It resembles that of the Wills Creek of 

Maryland, but as assignment of the formation 

to the Wills Creek would necessitate the assump.,. 

tion of a large hiatus at the top, for which there 

is insufficient evidence, it is better to refer the 

beds to the Tonoloway in spite of their lithologic difference from the Tonoloway elsewhere. 

The Keyser-Coeymans contact ·is likewise 

very sharp. The platy barren beds at the top 

of the Keyser are overlain immediately by the 

coarse siliceous fossiliferous limestone of the 

Coeymans. 

Section at north end of Pennsylvania Avenue, Ty--,one. 

Helderberg limestone: 

I Total 

Thick- thick- ness. ness. 

Coeymans limestone member: 

Limestone, coarse, gray, crystalline, crinoidal; fossil fragmentsshowonsurface. Basal Feet. Feet. 

1 foot siliceous....... . . . . . . . . . 4. 0 4.0 

Keyser limestone member: 

Limestone, fissile, laminated, 

fine grained, yellow ......... . Concealed; probably shaly limestone ........................ . Limestone, platy and impure; 

buff on weathered surface, 

drab on fresh fracture ........ . Limestone, massive, fine 

grained, yellow; irregular 

fracture .................... . Limestone, fissile, shaly ....... . Limestone, massive, fine 

grained, yellow; irregular 

fracture. Color probably 

due to weathering, though 

the rock is firm ............. . 

4. 0 ..... · ... 

1.8 

2.9 

7.2 

1.7 

1.0 

95. 5 

93. 7 

90.8 

83.6 

81. 9. 

80.9 

Section at north end of Pennsylvania Avenue, Tyrone-Con. 

. Total 

Thick- thickHelderberg limestone-Continued. 

Keyser limestone member-Cont'd. 

Limestone, laminated, fissile; 

light gray on weathered sur- face, drab on fresh fracture ... Limestone, relatively impure, 

platy; light gray to buff ..... . Limestone made up mainly of 

partly silicfied stromatoporoids ....................... . Limestone, shaly, yellow ...... . Limestone, compact, light gray; 

conchoidal fracture. Scattered stromatoporoids; Leperditia sp., 63.4 ....... ~--- ... . . . Limestone, impure, platy, buff. 

Limestone, c o m p a c t, · fine 

grained, very light colored. 

Leperditia sp., 61.4 ........... . 

Limestone, made up entirely of 

stromatoporoids . and corals, 

mainly the former ........... . Limestone, impure, shaly, fine 

grained, light gray. Corals 

and stromatoporoids near base. 

Limestone, fine grained, light 

' gray to buff; conchoidal fracness. 

Feet. 

3.4 

7.0 

1.7 

.2 

.8 

.5 

1.0 

2.0 

2.0 

ture. Unit partly concealed. 

Scattered corals and stromatoporoids; Favosites sp., Leperditia sp., 56.4; Leperditia 

sp., 54.0..................... 6. 2 

Limestone, light gray to buff, 

fine grained, massive. Cross 

sections of Leperditia on weathered surface..... . . . . . . . 3. 6 

Concealed; probably shale...... 1. 0 

Limestone made up of stromatoporoids and corals. Cladopora rectilineata, 44.4.......... 7. 2 

Limestone, light gray; almost 

entirely coral. Cyathophylloid corals, Favosites sp., 

Cladopora rectilineata, and 

stromatoporoids are very 

abundant; Rhynchospira sp., 

30.9......................... 12.3 

Limestone in single bed, light 

gray, fine grained; conchoidal 

fracture. Pholidops ovata, 

Stropheodonta bipartita, Whitfieldella cf. W. nucleolata, 

Meristella sp.?, 26.4........... 1. 2 

Limestone, thin bedded (1 to 2 · inches), fine grained, impure, 

weathered, light gray. Whitfieldella cL W. nucleolata, 24.9. , 2. 3 

Limestone in two beds, coarse, 

crystalline, medium gray. 

Favosites sp., S tropheodonta 

bipartita, 22.4................ 1. 3 

Limestone, impure, shaJy, indistinctly nodular. Strophonella geniculata?, Schuchertella sp., Camarotoechia sp.?, 

Cladopora rectilineata, Stromatoporoidea, Bryozoa, 21.1; 

Whitfieldella cf. W. nucleolata, 18.9..................... 3. 7 

ness. 

Feet. 

75.8 

72.4 

65.4 

63.7 

63.5 

62.7 

62.2 

61. 2 

59.2 

57.2: 

51.0 

47.4 

46.4 

39.2 

26.9 

25.7 

23.4 

22.1 
208 SHORTER CONTR.IBUTIONS TO GENERAL GEOLOGY, 1917. 

Section at north end of Pennsylvania Avenue, Tyrone-Con. Section at north end of Pennsylvania Avenue, Tyrone-Con. 

Total Thick- thick- ness. ness. 

Helderberg limestone-Continued. 

Keyser limestone member-Contd. 

Limestone, solid, coarsely crys- Feet. 

talline, huffish gray ... _ . _ . . . 1. 7 

Limestone, thin bedded (1 

inch); gray, coarsely crystalline. ' Strophonella leaven'" 

worthana var., Atrypa reticularis, Spirifer octocostatus, 

Rhynchospira globosa var., 

Cladopora rectilineata, Eo tomaria sp., Bryozoa, 15.4 .... _ _ 2_. 4 

Limestone, massive, coarse, 

crinoid a 1, huffish gray. 

Schuchertella deckerensis,10.0, 

10.9; Atrypa reticularis, Spirifer octocostatus, Camarotoechia 

sp., Favosites sp., Stromatoporoidea, Bryozoa, 10.0·...... 4. 4 

Limestone, "bastard," gray, 

weathered, shaly. Cladopora 

rectilineata, Schuchertella deckerensis ,Bryozoa occur through- out; Atrypa reticularis, Rhynchospira globosa var., Rhyn- chospira lata?, Chonetes jerseyensis, 9.4; Spirifer octocostatus, 7.4, 9.4; Stenoschistnaformosa, Meristella sp.?, 6.4, 7.4; 

Leptaena rhomboidalis, Strophonella leavenworthana var., 

Camarotoechia sp.?, 6.4 ...... _ _ 4. 5 

Limestone, huffish gray, coarse- ly crystalline; weathers to a distinctly darker gray than 

the Tonoloway beds. Stropheodonta bipartita, Schuche?·t- ella deckerensis, Uncinulus 

sp., Atrypa reticulans, 3.9..... 1. 7 

Limestone, impure, gray; a " bastard " bed. Dalmanella 

concinna,Stropheodonta bipartita, Strophonella leavenworth- ana var., Chonetes jerseyensis, · Stenoschisma formosa, Atrypa 

reticuldris (a)~ Nucleospira elegans, Schuchertella sp., Cama1"0toechia sp. ?, Bryozoa, Pelecypoda, Ostracoda, 2.4. __ . . . 1. 7 

Shale, we~thered, yellow, irregular. Orthostrophia stropho"-

?nenoides, Atrypa reticularis, 

Bryozoa, 0.4 ............ _ _ _ _ _ _ 2. 0 

95. 5 

Tonoloway limestone: 

Limestone, buff, coarse looking; in 

single layer ................ ___ . . . . 6 

Limestone, banded, platy, dark drab on fresh surface, light gray on weathered surface .. .. . _ . . . . . . . . . . . 8 

Limestone, solid bed, buff, fine 

grained; has a diagonal cross fracture .. __ ... _ ....... _ . _ . __ ...... _ 1. 8 

Limestone, solid bed, dark drab; 

layer of ~hert at top. Looks as if 

it had been crushed and rece- mented. Leperditia sp., -3.3..... 1. 7 

Clay seam......................... .1 

Feet. 

18.4 

16.7 

14.3 

9.9 

5. 4 

3.7 

2.0 

-Q.6 

-1.4 

-3.2 

-4.9 

.:...5.0 

Total Thick- . thick- ness. 

Tonoloway limestone-Continued. 

Limestone, brown, weat~ered, im- pure ___________________________ _ 

Limestone, buff, banded, . thin bedded; fresh fracture brown; some layers rather red .. ____ .. __ ....... . - Limestone, vesicular, leached; fresh 

fracture whitish, with ferruginous 

spots .......... ............ - - - - - - - Limestone, buff to light drab, laminated; part :fissile, in part fairly 

so lid ----------- - -- --- --- - --.--- - - - Limestone, vesicular, leached ...... . Limestone, light drab, laminated, 

platy, fine grained; dark drab on freash surface ....... ...... ..... . Concealed ........................ . ' Limestone, vesicular; leached ..... . Shale, weathered, anQ. poorly ex- posed .................. , ....... . Limestone, composed mainly of 

geodal calcite; resists weather and 

projects above the surface ........ . Limestone, buff, . shaly, platy, 

weathered, and · poorly exposed ... Limestone, very light gray, has an earthy fracture and looks as if it · had been leached; much calcite 

in druses; a little chert .... ..... . Limestone, impure, platy, light 

drab; many cavities lined with 

calcite druses ..... : ............. . Limestone, buff, :fine grained, me- dium bedded (6 inches), blocl<:y 

fracture ......... . ............ . . . Limestone, shaly, platy, buff ...... . Limestone, fine grained, drab on fresh fracture .................... . Limestone and shale, very platy,fissile, buff ....................... . Limestone, massive, fine grain~d, 

weathered surface almost wh1te, · fresh fracture drab .............. . Shale and shaly limestone, stained - yellow .......... _ .. . ............ . Shale and shaly limestone, buff and 

light drab ...... , ............... . Limestone, buff, fine grained, impure; blocky fracture •...... : .... Shale, yellow, calcareous; breaks 

into irregular fragments ... _, _ _. ..... Oolite(?), very :fine, siliceous, chocolate-brown ....... . .... ..... ..... . Shale, ~\iff, more or less oolitic ( ?) 

and Slliceous ................... . Oolite ( ?) , v_ery fine, siliceous, choco- · late-brown, weathered somewhat; 

resembles a friable sandstone ..... Shale, :fissile, calcareous, weathered · surface very light colored ........ . Concealed; apparently shale. (Thick- ness ·of this and underlying units 

only approximate) .............. . Shale, -:fissile, calcareous, light 

colored ...........•.............. Limestone, massive, impure, buff; 

much calcite in druses in irregular 

cavities ... : ... -_ .- ......... .... : . . Concealed; some shale exposed .... . 

ness. 

Feet. Feet . . 

1.5 -6.5 

16.3 -22.8 -

4.8 -27.6 

17.5 -45.1 . 

1.0 -46.1 

13.5 -59.6 

6. 5 -66.1 

5.0 -71.1 

3.3 -74.4 

.4 -74.8 

19.7 -94.5 

.8 -95.3 

9.0 -104.3 

3.3 -107.6 

8. 3 -115.9 

0 8 -116.7 

11.0 ·-127. 7 

4.0 -131.7 

2. 8 -134. ~ 

6. 2 -140.7 

1. 0 -141.7 

1. 5 -143.2 

11.0 -154.2 

6.0 :-160.2 

20.0 -180.2 

12.0 -192.2 

30.0 . -222.2 

28.0 -250.2 

6.0 -256.2 

15.0 -271.2 
• 

i 

• 

HELDERBERG LIMESTONE OF CEN'P'RAL PENNSYLVANIA. 209 

Section at north end of Pennsylvania Avenue, Tyrone-Con. 

Tonoloway limestone-Continued. 

Limestone, thin bedded (1 to 2 

inches), banded, fine grained, buff; geodal calcite. _____ ........ . 

Clay seam ... _ ... _ ................ . Shale, fissile, calcareous, light colored_ ... _ . ___ . _ .............. . 

Limestone, massive, impure, buff; 

looks as if it had been crushed and 

recemented ... _ ..... _ . _ . ~ . _ . __ .. 

Clay seam, weathered .... _. _ . . . _ . ... Shale, fissile, light drab .... _._ .. _._. 

Limestone in 6-inch courses, im~ 

pure, buff_ ...................... . Shale, fissile, calcareous, light drab . on fresh surface, almost white on weathered surface ............... . Limestone, in 6-inch courses, impure, buff ....................... . Limestone, massive, buff, impure; 

contains cavities with calcite 

druses; looke. as if it had been 

crushed and recemented •...... _ . Limestone, thin bedded (1 to 2 

inches), banded, fine grained, 

buff ........................... . 

Total 

Thick- thick- ness. ness. 

Feet. Feet. 

6.0 -277.2 

.5 -277.7 

10.0 -287.7 

8.0 -295.7 

1.0 -296.7 

5.0 -301.7 

2.0 -303.7 

4.0. -307.7 

4.4 -312.1 

5.5 -317.6 

8.0 -325.6 

325.6 

This section is remarkable for the barrenness 

and peculiar lithology of the Tonoloway and 

for the' sharpness of the Tonoloway-Keyser contact. In the Keyser itself the fauna of the 

Chonetes jerseyensis zone. is .well developed, but 

the characteristic nodular beds ·are lacking. 

The presence of Cladopora rectilineata in considerable abundance in this lower zone is noteworthy. The characteristic brachiopods of the 

Favosites zone and Tentaculites gyracan.thus are 

not represented by even a single specimen. 

This zone, on the other hand, carries a profufusion of corals and stromatoporoids, and in 

this respect the section resembles no other 

section studied except that at Grovania. 

MAPLETON. 

A very gpod exposure of part of the Tonoloway and nearly all f the Keyser member of 

the Helderberg is to be seen in the quarry of 

L N. Swope _on the north ba:p.k of Juniata 

River directly opposite Mapleton (or Mapleton 

Depot); The Tonoloway at this place is characteristically developed and, in addition, contains several beds with fossils that suggest more 

normally marine conditions than those under 

which the rather barren faGies occurring in 

most of the other sections studied · were laid 

down. The Keyser ·has near its base a thick 

bed of pure · crinoidal limestone, which is comparable to that exposed near Burnham, north 

of Lewistown. The contact of the Keyser 

and Coeymans was not seen at this locality. 

The section was measured from the exposures 

directly north of the end of the bridge over the 

Juniata: 

Section in Swope quarry, near Mapleton. 

Helderberg limestone (Keyser limestone · member): 

Co_ncealed by talus, quarry waste, 

etc. Much of the talus of the 

upper part is ash-colored shale. 

Limestone, light-gray; banded on weathered surfaces; fresh surface 

dark ·gray, fine grained, not 

banded; conchoidal fracture; 3-

inch courses separated by shale. 

Leperditia sp., 150, 149.1; Bryozoa, 148.1, 145.7; Tentaculites gyracanthus, Ostracoda (a), 148.1; 

Spirorbis laxus (a), 147.2; Whitfieldella cf. W. nucleolata, 145.7?, 

144.7 ... ------- ... --- ....... ----.- Limestone, like unit above but not 

in courses separated by shale; 

fairlymassive. Pelecypoda,142.7. 

Shale, calcareous, "Weathered, yellow_ 

Limestone, very light gray, compact, 

fine grained; dark on fresh surface; 

faintly banded .... __ .. __ ....... . Limestone, composed entirely of 

stromatoporoids ................ . Shale, weathered yellow~ ......... . Limestone, massive, light gray; com- posed of stromatoporoids ........ . Limestone nodules, large, in shale 

matrix ......................... . Limestone, rather platy, shaly, dark 

gray. Stromatoporoids, 129.7; 

Leperditiasp., 128.7 .............. _ Limestone, dark gray, conchoidal, 

impure, fine grained; in 2 to 12 

inch courses, separated generally 

by thin shale laminae. Pholidops 

ovata, 121. 7, 109. 7; Rensselaeria 

mutabilis, Rensselaeria keyserensis, 

121.7; Spirijer vanuxemi var. prognosticus, 121.7-108. 7; Uncinulus 

nucleo latus (a), 119.7-108.7 ; Leperditia sp., 118.7, 108.7; Pelecypoda, 117.2 (a), 109.7 (c); OstraTotal 

Thick- thick- ness. ness. 

Feet. Feet. 

9.0 153.1 

4.8 144.1 

. 9 ' 139.3 

2.8 138.4 

.9 135.6 

.8 134. 7 

3.0 133.9 

: 8 130.9 

4.3 130_.1 

coda, 113.7, 108.7; Gyp~dula coeymanensis prognostica, 109. 7. . . . . . . 19. 1 125. 8 

Shale, calcareous, containing large 

nodules (diameter 5-6 inches) of 

limestone and one or two beds of 

fine-grained conchoidal blue limestone. Uncinulus nucleolatus 

throughout; Aulopora sp., 106.7, 

104.7 (c); Stromatoporoidea, Bryozoa, 106.7 (a), 102.7; Pholidops 

ovata, 106.7; Favosites sp., 104.7 

(c), 102.7; S chuchertella interstriata?, Pelecypoda, Ostracoda, 

104.7 (a); Spirorbis laxus, Meri- . stella praenuntia, 102.7. . . • . . . . . . . 4. 3 106. 7 
210 SHOR.TER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

Section in Swope quarry, near .1llapleton-Continued. 

h . I Total T Iek- thi k- ness. ne~ . 

----------------------~-------- 1-----------

Helderberg limestone (Keyser limestone 

member )-Continued. . 

Limestone, rather shaly, dark gray; 

single bed. Favositessp., Stromatoporoidea, Dalmanella concin~, 

Schuchertella prolifica, Uncinulus 

nucleolatus (a), Rensselaeria keyserensis, Ostracoda, 101.7 ........ . Limestone, massive, impure, gray; 

nodular character indistinct; 

weathers thin bedded at top of 

quarry. Favosites sp., Bryozoa, 

Atrypa reticularis (c), 99.7 ....... . Limestone, -massive, impure, nodular. Pholidops ovata, Uncinulus 

keyserensis (a), 96.7 ............... . Shale, weathered, yellow .......... . Limestone, : impure, nodular, dark 

gray, somewhat crystalline. Fa- vosites sp., Aulopora sp., Uncinulus keyserensis, Orthoceras sp., Calymene camerata?, 95.7; Bryozoa, 

Ostracoda, 93.2 ................ . Limestone, impure, dark gray; many 

cleavage faces of calcite show, 

giving it a coarse grain; very mas- sive unit; shows indistinct nodularstructure. Favosites sp., 91.7 ... Limestone, much_ like unit above 

but does not show; the nodular 

structure. Stromatoporoidea, 80.0. 

Limestone, dark, much weathered 

in places, massive. Favositessp., 

Bryozoa (c), Rhynchospira globosa 

var., 75.7 --·· ··············-.·-··· Limestone, pure bluish crystalline 

layers alternating with shaly 

dark-gray impure layers; the 

whole mak-es a massive unit. 

Bryozoa throughout; Cladopora 

rectilineata, 74.2, 70.7; Aulopora 

sp., 74.2; Favositessp., 72.7;Stropheodonta bipartita, Schuchertella 

deckerensis, Atrypa reticularis, Caly- mene camerata, 70.7 ............. . Limestone, light gray, fine grained, 

conchoidal fracture ........•.... _ . 

Limestone, massive, coarselv crystalline, bluish; many small chert 

nodules. Favosites sp., ·Bryozoa, 

Leptaena rhomboidalis, Stropheodonta bipartita (c), Camarotoechia 

sp.?, 65.2 .......... ~ ... . ........ . Limestone, blue gray, coarse, crystalline, pure, thin bedded (2 to 6 

inches). Bryozoa (a), Leptaena 

rhomboidalis, Stropheodonta bipartita, Strophonella geniculata, Schuchertella interstriata?, Camarotoechia litchjieldensis, Atrypa reticularis, 63.7 ................••...... Limestone, shaly,, impure, '' bastard"; weathers light gray and 

yellow; finely nodular. Bryozoa, 

Strophonella geniculata, Atrypa 

reticularis throughout; Stenoschisma deckerensis, 58.7, 55.7; Spirifer octocostatus, Favosites sp., 

Eotomaria sp., 58.7; Stenoschisma 

formosa, Spirijer modestus?; Spirifer vanuxemi, Rhynchospira formosa, Dalmanites mi:-rurus?, 56.7 _ . 

Feet. 

1.6 

3. 1 

1.3 

. 5 

3.4 

5.6 

8.8 

3. 9 

5.0 

2.0 

2.4 

1.1 

9.6 

Feet. 

102.4 

100.8 

97. 7 

96.4 

95.9 

92.5 

86.9 

78.1 

74.2 

69.2 

67.2 

64.8 

63. 7 

Section in Swope quarry, near .Mapleton-Continued. 

Helderberg limestone (Keyser limestone 

member-Continued. Limestone, bluish gray, crystalline, 

single bed, fairly pure.: ... _ ..... . Limestone, very impille, earthy, 

dark gray; shaly fracture: Da~­

manella concinna, Atrypa reticularis, 50.7 ... . .................. . 

Shale, fissile, calcareous; weathers a 

ferruginous bro·wn; has some nodules near top. Bryozoa; Pholidops 

ovata, Dalmanella concinna, Dalmanella clarki, Leptaena rhomboidalis, · Stropheodonta bipartita?, 

Chonetes jerseyensis, Atrypa reticularis, Spirijer modestus plicatus, 

49 .. 2 ..... - ................. · ..... . 

Limestone, impure, nodular, dark, 

single bed. Orthostrophia strophomenoides?, Dalmanella concinna, Stenoschisma formosa, Atrypa reticularis (a), 48.7 ... : ............. . 

Limestone, fairly pure, blue, crystalline; nodular character lacking on fresh surfaces and very indistinct on weathered surfaces; thin 

bedded (2 to 4 inches); a few 2-

inch chert nodules scattered near top. Atrypa reticularis, 41.2-46.7; 

Spirifer octocostatus, 46.7, 45.7; 

Orthostrophia strophomenoides, Dalmanella concinna, Stropheodonta 

bipartita, S chuchertella deckerensis, 

43.7; Camarotoechia litchfieldensis, 

43.7; Crinoidea, Bryozoa, Pholidops ovata, ~tenoschisma deckerensis, 41.2 ........................ . 

Limestone, nodular, relatively impure, rather coarse grained and 

with considerable in terlaminated shale: would be classed as a "bastard'' limestone, but it is 

purer than the unit beneath. 

Dalmanella conciniw, Dalmanella 

clarki, Stropheodonta bipartita, 

Chonetes · Jerseyensis, Atrypa 

reticularis, Platystoma niagarensis?, 39.1---·····-·········-·--·· 

Limestone, shaly, very nodular, 

"bastard," light gray and brown on weathered surfaces. Crinoidea, 

Stropheodonta bipartita·, Chonetes 

jerseyensis, Atrypa reticularis, Spirifer octocostatus, Pelecypoda, 

throughout; Orthostrophia strophomenoides, 38.7; Dalmanella con- cinna, Nuc,leospira elegans, 38.71 

35.5; Rhipidomella emarginata?; 

37.7;· Leptaen(J,· rhomboidalis, Strophonella geniculata (c), Schuchertella deckerensis, Platystoma ni: 

agarensis?, 37.7, 35.5; Aulopora 

sp., Spirorbis sp., Bryozoa (a), 

Dalmanella clarki, Dalmanella cf. 

D. perelegans, Schuchertella interstriata?, Ste'noschismaformosa (c), 

Stenoschisma deckerensis, Camarotoechia litchfieldensis, Rhynchospira globosa, Nucleospira ventri- cosa, Orthoceras sp., Calymene 

camerata, 35.5 .................. . 

Total 

Thick- thick- ness. 

Feet. 

2.8 

1.5 

1.0 

2.0 

5.6 

2:4 

3.5 

ness. 

Feet. 

54.1 

51.3 

49.8 

48. 8 

46.8 

- 41.2 

38.8 
•• 

, 

.. 

• 

HELDERBERG LIMESTONE OF CENTRAL PENNSYLVANIA. 211 

Section in Swope quarry, near Mapleton-Continued. 

Helderberg limestone (Keyser limestone 

member )-Continued. 

Limestone, coarsely crystalline, 

light gray, very pure (98 per cent 

CaC03 ), extremely massive and 

crinoidal. Bryozoa, 32.3, 9.4 (a); 

Pholidops ovata, Leptaena rhomboidalis, Camarotoechia sp., Proetus 

pachydermatus, 32.3; Stropheodonta 

bipartita, 24.7; Schuchertella sp., 

Meristella sp., 19.4; Sphaerocystites multifasciatus, Dalmanella . clarki, Stenoschisma formosa (c), 

Camarotoechia litchfieldensis -(a), 

Atrypa reticularis (c), Rhynchospira globosa var. (a), Rhynchospira formosa, 9.4 .............. . Limestone, thin bedded (2 to 3 

inches), dark gray, fine grained, 

distinctly nodular .............. . Limestone, somewhat nodular but 

yet massive, dark gray, fine 

grained. Leperditia sp., 2. 7 •...... 

Tonoloway limestone: 

Limestone, medium bedded ( 4 to 12 

inches), pure, dark gray, not 

banded; shale between the courses. Leperditia sp. throughout; Favosites sp., - 30 .......... . Limestone, thin bedded (3 to 6 

inches), pure, dark gray, fine 

grained; banded and light gray on weathered surface ........... . Shale, calcareous .................. . Limestone, massive, dark gray, 

fine grained, pure; conchoidal 

fracture; in places shows a l-inch 

bedding. Leperditia sp. throughout ............................ . Limestone, light gray, in 3-inch courses with shale between ...... . Limestone, massive bed, very light 

gray, fine grained; conchoidal 

fracture. In this unit there has 

been dissolved out a good-sized cave reaching down to an un- known depth. The limestone seems very pure and has small 

scattered masses of crystalline 

calcite. Leperditia sp., -15.4, 

-16.4 ......................... . Limestone, banded, thin· bedded 

(2 inches) but not fissile, light 

gray, pure. Leperditia sp., -20.8. 

Travertine ........................ . Limestone, banded, thin bedded, 

light gray. Leperditia sp., -26.3. 

Limestone, very platy, fissile; 

weathered . surfaces have a faint 

greenish tinge ................. .. Limestone, rather irregular, heavy 

bed, fine grained, light gray, 

pure ........................... . Limestone, very platy, fissile, light 

gray, fine grained; seems fairly 

pure. Leperditia sp .. (a), -33:2 ... Limestone, dark gray, with a 4-

inch layer of chert at center ..... . 

Total 

Thick- thick- ness. ness. 

Feet. 

29.8 

1. 7 

3.8 

153.1 

6.8 

2.8 

.2 

3.8 

1.8 

4.0 

5.5 

. 5 

3.6 

2.6 

1.2 

3.4 

1.3 

Feet. 

35.3 

5.5 

3.8 

- 6.8 

9.6 

9.8 

13.6 

15.4 

19.4 

24.9 

25.4 

29.0 

- 31.6 

- 32.8 

36.2 

37. 5 

Section in Swope quarry, near Mapleton-Continued~ 

Total 

Thick- . thick- ness. ness. 

------------------------------1~---~----· 

Tonoloway limestone-Continued. 

Limestone, massive, finely (1 inch) 

but distinctly nodular, dark gray, 

impure. Corals, Stromatoporoidea, Spirorbis laxus (c), Bryozoa, 

Camarotoechia litchjieldensis, Le- Feet. Feet. 

perditia sp. (a).................... 3. 0 - 40: 5 

Limestone, massive, fairly pure, 

blue-gray. . .. . .. . .. . .. .. .. . .. .. . 3. 6 44. 1 

Limestone, fissile, platy, dark gray; 

layer of chert at -45.2. Leperditia sp. (c) throughout........... 5. 2 49.3 

Limestone, fairly solid, banded, 

dark gray, fine grained........... 8. 9 58.2 

Limestone, fissile, shaly, impure; 

drab on fresh surface. Leperditia sp., -62.2................. 5. 6 63.8 

Limestone, fairly pure, knotty, 

light gray, fine grained.......... 1. 5 65.3 

Limestone, fissile, we a the red, 

brown and gray, fine grained, 

impure. Favosites sp., Rhynchospira globosa, Ectomaria minuta 

(c), Leperditiasp. (a), -66.2 ...... 12.4 77.7 

Concealed... .. .. .. .. .. .. .. .. .. . .. . 5. 9 83. 6 

Shale, weathered, calcareous, gray 

to brown. Leperditia sp., -89.2.. 7. 4 91.0 

Shale, poorly exposed, weath~red... 4. 0 95. 0 

Limestone, fissile, impure, gray. 

Leperditia sp., -96.5 to -97.5.... 5. 5 -100.5 

Limestone, platy, gray; looks much 

purer than unit above or below. . . 1. 0 -101. 5 

Limestone, fissile, impure, weathered brown... .. .. . .. .. .. .. . .. .. . 1. 0 -102. 5 

Concealed ..... --...... .. .. .. .. .. .. 3. 8 -106. 3 

Limestone, thin bedded ( 4 to 6 

inches), impure·, light gray....... 5. 0 -111.3 

Shale, calcareous, gray, and limestone, gray to brown, weathered, 

fine grained; alternating layers of 

each about 3 inches thick....... . . 9. 4 -120. 7 

Shale, fissile, ash-colored, calcar- eous............................ 5. 5 -126.2 

126.21 

The Mapleton section is noteworthy because 

it contains several zones of the Tonoloway of 

a more normally marine· facies than was 

observed In any other section studied. In 

this feature it resembles parts of the Maryland 

Tonoloway that carry a relatively large marine 

fauna. The thick crinoidal unit near the 

base of the Chonetes jerseyensis zone of the 

Keyser is also notable. The Favosites zone of 

the Keyser contains a subzone with Oladopora 

rectilineata and other corals at about the 

horizon of the profuse coralline development at 

Tyrone and Grovania. · As in those sections also, 

it has a Stromatopora reef well up in .the Keyser 

and shows a rarity of such forms as Rensselaeria 

mutabilis, ~Meristella praenuntia, and TentaC'llr 
212 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

lites gyracanthus. The abundance: of Uncinulus Section on Ki8hacoquillas Pike at Mo'unt Rock, Lewistownnucleolatus in the Favosites zone is not paralleled · Continued. · · · · 

in any other section studied. 

MOUNT ROCK, LE.WISTOWN. 

The section given below begins just across 

the Kishacoquillas Pike from the Spanogle· & 

Yeager Co.'s flour mill at Mount Rock and 

extends southward · along the pike past the 

west end of the bridge over Kishacoquillas 

Creek. It lies about 100 . yards south of the 

Lewistown & Readsville Railway Co.'s power 

house and car barn. 

E. V. d'Invilliers/ describing the geology of 

Derry Township, Miffiin County, refers to this 

section very briefly. He gives the thickness 

of the limestone and lime shales of the Lewistown exposed here as · 350 ·feet and mentions 

several massive beds. 

The ·lowest exposures reveal the top of the 

Tonoloway. Above these a large part of the 

Keyser member of the Helderberg is to be 

seen, though the uppermost part of the ·Keyser 

·is concealed. The Coeymans, New Scotl~nd, 

and Oriskany are well developed. The section 

given below extends from the lowest exposure 

up into the new Scotland. It is probable that 

part of the . beds overlying those d,efinitely 

known to be New Scotland are also of that age, 

but the data at hand are insufficient to determine the position of the New Scotland-Oriskany 

contact.-

Section on Kishacoquillas Pike at Mount Rock, Lewistown. 

Thick- T<_>tal ness. thickness. 

-------------------------------1-----. -----

Concealed. 

Helderberg limestone: 

New Scotland limestone member : Lime~tone, very dark, impure, Feet. Feet. 

fissile .......... : .. _. . . . . . . ... . . 3. 0 18. 5 

Shale, weathered brown, very 

fissile; contains some bands of 

very dark impure limestone. . . 10. 4 15. 5 

Limestone in two beds (12 and 9 

inches) separated by shale 

(9 inches), fine grained, bluegray, crystalline. Meristellasp. 

throughout; Dalmanella pe:relegan,Q, Stropheodonta beckii?, 

Eatonia medialis, Atrypa reticularis?, Spirifer macropleurus (a), 

Spirifer perlamellosus, Ostracoda, 156.7; Rhipidomella 

oblata?, Schuchertella woolworthana (a), Chonostrophia 

helderbergiae?, 3.2 ........ :: .. .. . 2. 5 5. 1 

1 Pennsylvania Second GeoL Survey Rept. F3, p. 256, 1891. 

Helderberg limestone~Continued. 

New Scotland limestone memberContinued. 

Limestone, single bed, light gray, 

cherty, fine grained; some calcalcite cleavage faces show; 

does not scratch . hammer. 

Bryozoa, Dalmanella perelegans, Stropheodonta planulata, · Qamarotoechia sp., Eatonia 

medialis, 2.5 .....•....... - - -.. 

Coeymans limestone member: 

Shale, weathered, brown ......... . Limestone, single b~d, light gray, 

cherty. Stropheodonta arata, 

Schuchertella sp., Gypidula 

coeymanensis, Atrypa reticularis, . Meristella sp., 8.2 .... . . _. 

Shale, weathered, dark gray, 

calcareous; limestone bands 

and large nodules. Lingula 

s:p., Leptaena rhomboidalu, Stropheodonta planulata?, 

Schuchertella woo.lworthana, 

Chonetes cf. C. hemisphericus, 

Pelecypoda, Orthoceras sp., 

Ostracoda (a), 7.3 ... : ......... Limestone, inassive, sandy, crystalline, blue; some bhtckchert 

nodules; very tough, hard 

rock. Dalma.nella perelegans?, · Leptaena rhomboidalis, Gypidula coeumanensis, Atrypa reti- cularis, Pelecypoda, 5.3; Camarotoechia sp. ?, Spirifer cyclopteris, 5.3, 2.0; Stropheodonta arata, 2.8; Bryozoa, 

Pholidops ovata, Rhipidorru:lla 

oblata?, Strophonella leavenworthana (c), Phacops logani, 

Dalmanites sp., 2.0 ........... . 

Keyser limestone member: 

Limestone, dark gray; fine ~a~ned, .thin bedded. Leper- d~tw sp ..................•.. · .. Limestone, massive, dark 'gray, 

fine grained; conchoidal frac- ture~., ..............••........ Limestone, . shaly, yellow, 

weathered .................... . Limestone, massive, dark gray, 

impure, fine grained; con- choidal fracture ........... . .. . Shale, weathered .... · ....... __ .. Limestone, light gray, solid, fine 

grained; conchoidal fracture ... Limestone, platy, dark gray, impure ..... _ ................... . Concealed ...... . _. ~ .......... , Limestone, platy, light gray, impure, fine gramed; conchoidal 

fracture ..................... . ·Concealed ...... _ ........... _ .. _, 

Thick- T~tal ness. thickness. 

Feet. Feet. 

2. 6 2. 6 

18.5 . 

. 6 10.6 

2. 3 10.0 

1. 5 7. 7 

6. 2 6.2 

10.6 

1.0 157.9 

2.0 1,56. 9 

1.0 154. 9 

2.5 153~9 

2.0 151.4 

1.0 149.4 

3.0 148.4 · 

5. 1 145.4 

2.0 140.3 

6.2 ·138. 3 
HELDERBERG LIMESTONE OF CEN'fRAL PENNSYLVANIA. 213 

Section on Kishacoquillas Pike at Mount Rock, Lewistown-:-

Continued. 

Section on KishacoquWas Pike at Mount Rock, LewistownContinued. · . . 

Thick- Total Thick- Total 

thick- thick- ness. ness. ness. ness. 

------

Helderberg limestone-Continued. Helderberg limestone-Continued. 

Keyser limestone member-Contd. Keyser limestone member-Contd. -

· Limestone, impure, platK, yel- Limestone, thin bedded, bluelow; weathered muc and Feet. Feet. gray, crystalline. Spirijer van- poorly exposed ..•.... ~ ......... 3.8 132.1 uxemi prognosticus, 80.2, 81.2; 

.Limestone, platy, 7eure, weath- Pholidops ovata, 80.2·; Cam.aroered, yellowish, eristella Feet. sp .. 4. 0 128.3 techia litch.fieldensis, Rensselaeria Feet. 

Limestone, massive, light gray; mutabilis, Pelecypoda, 79.2 .... 2. 9 81.5 

conchoidal fracture ............ 1.5 124.3 Limestone, massive; in part light 

Limestone, thin bedded (2 blue-gray, fine grained; in part 

inches), dark gray; conchoidal subcrystalline. · Bryozoa, Dalfracture ..•...... , ............ . 1. 0 . 122.8 .manella sp., Pelecypoda, 78.2 .. 2.4 78. 6 

Concealed. Dalmanella sp., Limestone, thin bedded (2 to 6 

Schuchertella proli.fica, Rensse- inches),. fine grained, light 

laeria keyserensis, Metistella bluish gray; conchoidal fracpraenuntia?, Hormotom.a sp., ture: Atrypa reticularis, CaBryozoa loose on surface ....... 16. 6 121. 8 marotoechia, sp., throughout; 

Limestone, banded; conchoidal Pholidops ovata (a), Dalmafracture . . Meristella sp.?, Ten- nella concinna, Merista typa, 

taculites gyracanthus, 105.2 .... .5 105.2 Ostracoda, 75.2 ................ 7. 1 76.2 

Concealed ...................... 1.0 104. 7 Limestone, impure, shaly, alLi:nr\3stone, very impure. Ten- ternating with harder layers, 

taculites gyracanthus, Rensse- each in about 6-inch courses. laeria mutabilis, Bryozoa, Pe- Pholidops ovata, Rensselaeria 

lecypoda, 103.2 ............... 2.0 103. 7 mutabilis (a); 68.2 ............ 3.4 69.1 

Limestone, thin bedded, fine Concealed .• : ......•............ 4.2 65.7 

grained, dark ray' impure, Limestone,· shall, impure, with 

poorly expose . Pholidops hard layers o more resistant 

ovata, Re'nsselaer1"aobtusa, Pele- . rock. Dalmanella concinna, 

cypoda, throughout; Bryozoa, Leptrena rhom.boidalis, StroS chuchertella interstriata?, Rens- pheodonta bt::rtita, Camarotoeselaeria m.utabilis, Tentaculites chia litch.fie densis, Atrypa re- gyracanthus, Orthoceras cf. 0. ticularis, Spirijer vanuxem.i 

pauciseptum., Ostracoda, 101.2; prognosticus, 60.7 •............ 1. 7 61. 5 

Cam.arotoechia sp.?, Meristella LimestOne, dark gray, crystalsp.?, 99.2 .•................... 4.0 101.7 line. Bryozoa, Stropheodonta 

Limestone, impure, dark gray, bipartita, Rensselaeria mutabithin bedded, fine grained. lis, Merista typa, Calym.ene 

Bryozoa, Pelecypoda, through- camerata, 56.2 ...•............. 5. 1 59.8 

out; Rensselaeria keyserensis (a), Limestone, tl~in bedded ( 1 to 6 

97.7; Tentaculites gyracanthus, inches), light blue-gray, fine 

96.2, 97.7; Dalmanella sp., Schu- raained, impure; has shale 

chertella proli.fica, Uncinulus aminre between the layers 

keyserensis (c), 96.2; Rensse- and several small lenses of 

laeria (Beachia) proavita, 95.2, brown weathered chert. Bry96.2; Meristella sp.?, 96.2 ...... 4.3 97. 7 ozoa, Leptaena rhomboidal is, 

Concealed. Bryozoa (c), Pho- Calymene camerata, 52.2, 54.7; 

lidops ovata, Rensselaeria ob- Stropheodonta bipartita, 50.2, 

tusa?, Meristella s~.?, Pelecy- 53.2; Spirijer vanuxemi, 53.2; 

poda, loose on sur ace ......... 5. 9 93.4 Merista typa, 52.2; Schuchertella deckerensis,, 50.2 .......... 5.8 54. 7 Limestone, very shaly, with Limestone, massive, nodular, imhurer fine grained light-gray . pure, dark gray. Bryozoa, ands. Spirifer vanuxem.i 42.2-47 .2; Leptaena rhomboidaprognosticus, · Pelecyr,odia, lis, Stropheodonta bipartita, throughout; Uncinulus eyser- Schuchertella interstriata?, A try- ensis, Dalmanella concinna, pa reticularis, 4·7 .2; Dalm.anella Meristella sp.?, 87 .2; Pholidops concinna, S tenoschisrhaformosa, ovata, Stenoschisma formosa?, Spirijer vanuxemi, Orthoceras Rensselaeria (Beachia) proavita, s:p., 45.2; Gypidula coeymanen- Ostracoda, 86.2 ............... 2.8 87.5 sts prognostwa, 42.2; Merista 

Limestone, verycoarselynodular typa, 41.2 ..................... 8.3 48.9 · (4 to 6 inches), light blue-Jray; Limestone, massive, dark gray, conchoidal fracture. Sh e be- impure, not very nodular. 

tween nodules. srr:;ijer van- Orthostrophia strophomenoides, 

uxemiprognosticust oughout; ·Btenoschurna formosa (c), 

Camarotoechia litch.fieldensis, Spirifer octocostatus, Merista 

Rensselaeria mutabilis, Pelecy- typa, 40.2; Gypidu,la coeypoda, 84.2; Uncinulus keyser- manensis Vfli. prognosti.cus (a), 

ensis, 82.2; 83.2; Rensselaeria At-rypa · reticularis, 38.2, 40.2; 

keyserensis, 82.2 ................ 3.2 84. 7 Bryozoa, 37 .2 ........ ~ ......... 4. 1 40.6 

• 
214 SHORTER CONTRIBUTIONS T'O GENERAL GEOLOGY, 1917. 

Section on Kishacoquillas Pike at Mount Rock, Lewistown- · Section on Kishacoquillas Pike at Mount Rock, LewistownContinued. - Continued. · 

Thickness. 

Helderberg limestone-Continued. 

Keyser limestone member-Contd. Feet. 

Shale, weathered, yellow ........ 0.5 

Limestone, very nodular, . impure, sbaly, g:ray; many of its fo~sils are silicified. Atrypa 

reticularis throughout; Pelecypod a, 35.2; Bryozoa, Dalmanella concinna, Strophonella 

leaventoorthana var., 34.2 ...... 2.4 

Limestone, massive, somewhat 

nodular, dark gray, subcrystalline, impure. Gypidula 

prognostica (a) throughout. 

Schuchertella swartzi'!, AtryfZO 

reticularis, 33.2; Dalmane la 

clp,rki?, Rhipidomella emarginata?, Leptaena rhomboidalis, 

Strophonella geniculata, Chonetes jerseyensis (c), Stenoschisma 

deckerensis (a), Rensselaeria mu- tabilis?, Nu.cleospira ventricosa, 

Goldius barrandt, Cyphaspis cf. 

C. minuscula, Calymene came- rata, Ostracoda, Pelecypoda, 

31.2 ----.-.--- -'•. ·--.-------- 2.8 

Limestone, very nodular, impure, dark gray, weathered .... 1.8 

Limestone, massive, not nodular, 

dark gray, coarselv crystalline. 1.6 

Limestone, nodular, ii.npure, 

weathered ; bastard · limestone 

with ·occasional thin lenses of 

black chert .. Ostracoda, 26.2. 2.6 

Limestone, crystalline, dark - blue, thin bedded, with shaly 

laminae. PelecyJlida, 23.8 ... 2: 0 

Limestone, crysta line, dark 

blue, pure, massive, not 

nodular. Schuchertella deckerensis (c), Chonetes jerseyensis, 

Uncinulus sp., Atrypa reticularis, 21.9 ................ ~ .... 1.9 

Limestone, weathered, very 

nodular. Chonetes jerseyensis, 

Stenoschisrnajorrnosa, throughout; · Dalmanella concinna, · Stropheodonta bipartit.a, Meristella sp.?, 17.2 ...... · ....•.... 4.4 

Limestone, massive, blue.-{!l"ay, 

coarse, crystalline, crinoidal; weath~rs thin bedded in upper part. Camarotoechi.a sp., 

Rhynchospira sp., throughout .................•........ 9.4 

Limestone, single massive bed, 

pure, dark gray, coarsely crystal line and crinoidal in part; 

fine grained. and curly in other 

part.s, which suggest slightly 

weathered Stromatopora. Sptrijer vanuxemi, 1.9 .............. 6.2 

Limestone, nodular, impure, 

weathered; crystalline on fresh 

fracture and blue-gray: Spirifer abundant on basal face ..... . 9 

157.9 

----

Total 

thickness. 

Feet. 

36.5 

36.0 

' 33.6 

30.8 

29.0 

27.4 

24.8 

22.8 

20.9 

16.5 

7.1 

. 9 

Tonoloway limestone: 

Total Thick- thickness. ness. 

Limestone, rather massive, fine 

grained, pure,_ dark gray, almost a blue-black; conchoidal fracture. 

Leperditia sp., . Camarotoechia? 

lamellata, -0.2, -2.3; Camarotoechia li"tchfieldensis, -0.2; Ostracoda 

(c), -17.3; Spirijer keyserensis, Feet. Feet. 

-2.3............................ 6.4 -6.4 

Limestone, thin bedded (1 inch); 

much like unit above, . but less ·massive and resistant; looks fairly 

solid where entirely unweathered; 

pure. Leperditia sp. throughout; 

Camarotoechia? lam,.ellata, -18.8 ... Limestone, solid-looking, heavy bedded, gray ...........••.•••.•..... Shale, weathered .......•.......•... Limestone, fairly solid, gray, in 

three beds (18, 12, 12 incb.~s) separated by shale ................... . Limestone, gray; weathers into small 

blocky fragments and has a some- what nodular appearance ..... · .... . Limestone, thin bedded, gray.· ...... . 

13.4 -19.8 

5.0 -24.8 

. 5 -25.3 

3.5 -28.8 

4.0 -32.8 

2.0 -34.8 

34.8 

This f;lection contains near the top of the 

Tonoloway formation the zone of Spirijer 

keyserensis which is present at the. same 

horizon at Dalmatia and in Maryland. The 

lower part of the Keyser member is massive 

and crinoidal, resembling the heavy crinoidal 

bed at Mapleton. The zone. of Gypidula 

coeymanensis var. prognosticus, so persistent 

and so well marked in Maryland, seems to be 

developed here, as at Selinsgrove Junction. 

The upper part of ·the Keys~r is ·so poorly 

exposed as to render the identification of the 

fossil zones difficult, but· the presence of .the 

Leperditia subzone just beneath the Coeymans 

is a feature of interest. 

CLARK'S MILL, NORTHWEST OF NEW BLOOMFIELD. 

The section ·given below lies along the 

Newport & Sherman's Valley Railroad a 

short distance north of McKee station and 

about 2 miles northwest of New Bloomfield, 

the county seat of Perry County. The highest · 

exposures are just opposite the old Clark's Mill. 

The section was measured and studied in 

1885 -by E. W. Claypole/ who divided it into 

1 Pennsylvania Second Geol. Survey Rept. F2, p. 182, 1885. 
I 

, 

" 

HELDERBERG LIMESTONE OF CENTRAL PENNSYLVANIA. 215 

the following: Black cherty limestone, 8 feet; 

Clark's Mill lime shales, 150 feet; Lewistown 

limestone, t"oo feet. His Clark's Mill lime 

shales he correlated in a general way with 

the "Delthyris shaly limestone" and "Lower 

Pentameru~ limestone" of New York-that is, 

with the Coeymans~N ew Scotland interval. 

The Lewistown he correlated with the "Waterl4n.e" or "Tentaculite" limestone of New York. 

This section was examined in 1913 by C. K. 

Swartz/ who cited Claypole's measurements 

and recognized in the lower 103 . feet the 

Tonoloway of Maryland and in the upper 150 

feet the Keyser of Maryland. 

In the . following section the beds in the 

upper 140 feet comprise the entire Keyser 

member of the Helderberg and are apparently · 

the same as those included by Claypole in his. 

Clark's Mill lime shale. The b.eds in the lower 

62 feet are equivalent to part of the Tonoloway of Maryland. The concealed interval 

immediately above the Keyser carries 

weathered Gypidula valves on its surlace, 

and it is likely that the Coeymans member ·of 

the Helderberg is represented by part of this 

interval. 

Section at Clark's Mill, about 2 miles northwest Jj New 

Bloomfield. 

· Concealed by residual clay, filled with 

white blocky chert, fragments of coarse sandstone, and thin, platy, shaly limestone. Immediately above the top of 

the Keyser, weathered Gypidula valves 

and segments of a larse crinoid column are abundant and indicate the probable 

presence of the Coeymans member of 

the Helderberg. 

Helderberg limestone (Keyser limestone 

member): 

Thick- T~tal ness. thickness. 

Limestone, fissile, platy, dark gray; 

fragments ring when dropped; no che~t; f~esh surface shows distinct Feet. Feet. 

lammatwn........................ 2. 0 139. 7 

Limestone, thin bedded, dark gray, 

with much interbedded black 

chert; one layer is about 10 inches 

thick; compact, bluish gray, with 

conchoidal fracture. Schuchertella 

prolifica, Meristella praenuntia, 

Tentaculites gyracanthus, Ostracoda 

(c), 137.7-136.7 .............. ~.... 5. 8 137.7 

Limestone, thin bedded, full of 

crinoid fragments and other fossils, crystalline. Bryozoa (a), 

Schuchertella prolifica (a), Meristella 

praenuntia (c), Tentaculites gyracanthus (a)........................ LO 131. 9 

Concealed by talus.................. 2. 7 130.9 

1 Maryland Geol. Survey, Lower Devonian, p. 105, 1913.-

Section at Clark's Mill, about 2 miles northwest of New 

Bloomfield-Continued. 

Helderberg limestone (Keyser limestone 

member)-Continued. 

Th. k Total IC - thick- ness. ness. 

Limestone, thin bedded (1 to 3 

inches), a little nodular, bluish 

gray; some of the layers are com- pact, with conchoidal fracture; 

others are subcrystalline, crinoidal, 

and crammed with fossils; the 

unit, however, looks homogeneous. 

Meristella praenuntia, Tentaculites 

gyracanthus, Bryozoa, Ostracoda, 

Pelecypoda, throughout; Orbiculoidea sp., Camarotoechia sp., ·127 .1; 

Orbiculoidea discus (a), 123.5; P.holidops ovata, 119.1-122.1; Orthoceras 

sp., 121.1; Whitfieldella cf. W. Feet. Feet. 

nucleolata, 113.6, 109.1. . . . . . . . . . . . 20. 1 128. 2 

Limestone, thin bedded, blue, crinoidal, subcrystalline, and 

crammed with fossil fragments. 

Bryozoa, Dalmanella clarki, 

Camarotoechia sp., Whitfieldella cf. 

W. nucleolata, .Meristella praenuntia, Tentaculites gyracanthus........ 1. 5 108. 1 

Concealed.......................... 3. 0 106. 6 

Limestone, crinoidal, bluish. Uncinulus keyserensis?, Uncinulus 

gordoni, Uncinulus nucleolatus, 

Whitfieldella cf. W. nucleolata, Orthoceras sp .................. ~..... . 5 103.6 

Concealed. Lingula sp., Orbiculoidea sp., Pholidops ovata, Dalmanella concinna?, Dalmanella clarki 

(c), Schuchertella prolifica, Schuchertella swartzi, Camarotoechia 

litchfieldensis, Uncinulus nuceolatus, Uncinulus keyserensis, Rensselaeria keyserensis (a), Rensselaeria · obtusa (a), Beachia proavita, Spirifer vanuxemi prognosticus, Rhynchospira sp., Nucleospira ventricosa?, Meristella praenuntia, Tentac;ulites gyracanthus, Orthoceras 

sp., Favosites sp., Spirorbis sp., 

Bryozoa, Pelecypoda, Ostracoda, 

loose on the surface................ 4. 7 103.1 

Limestone, gray, crammed with a ramose bryozoan, Uncinulus nu- cleolatus, Uncinulus keyserensis, 

Spirifer vanuxemi prognosticus, 

Ostracoda........ . .. .. . . . .. . . . . . . . l. 0 98. 4 

Concealed........................... 2. 0 97.4 

Limestone, compact, hard, bluish. 

Pholidops ovata, Camarotoechia 

litchfieldensis, Ostracoda (a)......... . 5 95.4 

Concealed. Bryozoa, Pholidops 

ovata (c), Dalmanella concinna, 

Dalmanella clarki, Leptaena rhomboidalis, Stropheodonta bipartita 

(a), Schuchertella swartzi, Camarotoechia litchfieldensis, Uncinutus 

keyserensis, Uncinulus mutabilis, 

Atrypa reticularis (a), Spirijer 

octocostatus, Spirijer vanuxemi var. prognosticus (a), Whitfieldella cf. W. nucleolata, Meristella · sp., Coelidium pennsylvanicum, 

Holopea antiqua?, Cyclonema sp., 

Tentaculites gyracanthus, Ortho- ceras sp., Calymene camerata, 

Ostracoda (a), loose on the sur- face.............................. 27.6 94.9 
216 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

Sectiqn at Clark's Mill, about 2 miles northwest of New Section at Clark's Mill, about 2 mil'ds northwest of New 

Bloomfield-Continued. Bloomfield-Continued. 

Thi k Total nes.~. - thickness. 

Helderberg limestone (Keyser limestone 

member)-Continued. 

Limestone, thin bedded, dense, · bluish; conchoidal fracture. Bryozoa, Ostracoda, throughout; Dalmanella concinna1 Leptrena rhom.-

boidalis, 67 .3-66.4; Stropheodonta 

bipartita, Schuchertella prolifica?, 

Uncinulus keyserensis, Spirijer 

vanuxemi prognosticus, Calymene Feet. 

camerata, 66.4 . . . . . . . . . . . . . . . . . . . . 4. 0 

Concealed. Favosites sp., Stroma-~ 

toporoidea, Bryozoa, Dalmanella 

concinna, Leptaena rhomboidalis, 

Strophonella geniculata?, Strophonella leavenworthana var., Uncinul us keyserensis, Spirifer vanux- emi prognosticus, loose on the 

surface........................... 20. 0 

Limestone, thin bedded, blue, ·nodular. Favosites sp., Chonetes jer- -seyensis, . throughout; Dalmanella 

sp. , Schuchertella deckerensis (a), Stenoschisma formosa, Camarotoechia litchfieldensis (c), Spirifer 

modestus, Pelecypoda, Ostracoda, 

42.3 .....•.....•................ -. 5. 0 

Concealed. Favosites sp., Stromatoporoidea, Chonetes jerseyensis, 

Meristella prrenuntia, Calymene 

camerata, loose on the surface. . . . . . 4. 6 

Limestone, very thin bedded, nodular, dark gray. Camarotoechia 

litchfieldensis, · 32.6, 31.6; Ostracoda, 30.6. .............. .. .. . . . . . 4. 2 

Concealed. Ectomaria: min uta, Hormotoma sp., loose on the surface... 3. 0 

Limestone, , thin bedded, much 

weathered and stained; debris 

full of fossils. Sphaerocystites multifasciatus, 24.5?, 26.5; Camarotoechia?, lamellata, Stromatoporoi 

dea, Stenoschisma formosa, Camarotoechia litchfieldensis, Spirifer mo- destus, Spirifer modestus var. plicatus'l, Rhynchospira globosa (a), 

Leperditia sp. (a), loose on the sur- face........................... . . . 6. 0 

Limestone, thin bedded, rather 

nodular, dark gray; upper 3 feet 

heavier bedded. Whitjieldella cf. 

W. nucleolata, 20 .§; Ectomaria 

minuta, 20.5?, 17.5; Leperditia sp. , 20.5, 17.5, 13.9 (a); Ostracoda, 17.5. 9. 9 

Concealed interval................. . 3. 0 

. Limestone, thin bedded, very nodular, bluish gray. Camarotoechia? 

latnellata, 6.6, 5.6; Spirifer van- uxemi, 6.6; Rhynchosptra globosa, 

6.6, 4.6; Leperditia sp., 6.6-3.6; 

Rhynchospira sp., 5.6; Ostracoda, 

5.6 (a), 3.6 .................. ·.'... 6. 6 

Limestone, single heavy bed, com- pact, dark gray .............. ~---... 1. 0 

139.7 

Tonoloway limestone: · · Limestone, rather ma8sive', dark gray, 

not nodular. Leperditia sp., '-1.5 . 3. 0 

Feet. 

67.3 

63.3 

43.3 

38.3 

33.7 

29.5 

26.5 

20. 5 

10.6 

7.6 

1.0 

-3. 0 

Tonoloway··limestone-Continued. 

Limestone, fissile, platy, yellowish, · banded; fossils very. rare; very different from overlying beds; gives a shingle-like talus; dark gray on fresh fracture ................. · .... . Limeston~, single bed, dark gray. · Leperditia sp., -8.9 to -9.9 ........ 

Limestone, dark gray, separated into 

l-inch courses by silicified seams l inch thick, which stand out a little in relief. Leperditia sp., 

-11.2 to -12.3 .................. . Limestone, single bed, ·knotty, dark · gray; weathers into laminre, ...... . Limestone, . platy, shaly; weathers 

into plates ........... : ............ . Shale, contorted, yellow, partly con- cealed ...•........................ Limestone, knotty, irregular, -yet 

massive ...•.•.•...•.............. Concealed .......................... . Limestone, very thin bedded, platy, . dark gray ..................... , .. . Limestone, massive bed, dark gray; ·breaks into thin plates ............. . Concealed ......................... . Limestone, massive, dark gray; 

breaks into. thin plates. Leperditia sp., -,-56.3 ................... . 

Concealed below. 

Thick- T?tal ness. thickness. 

Feet. 

5.9 

1. 0 

2.6 

3.6 

4.0 

4.0 

5.0 

7.5 

8. 6 

6.2 

4.5 

6.0 

61.9 

Feet. · · · 

-8.9 

-9.9 

-12.5 

-16,1 

-20.1 

-24.1 

-29.1 

-36.6 

-45.2 

-51.4 

-55.9 

-61.9 

The Clark's Mill section has the faunas of 

the Chonetes jerseyensis and Favosites helderbergiae var. praecedens zones well developed 

and is divisible into a number of subzones~ 

DALMATIA. 

An excellent exposure of part of the Tonoloway formation, the Helderberg, and the Oriskany is to be seen along the Northern Central 

Railway 1 mile south of Dalmatia. The lower 

beds are shown in a large abandoned quarry, 

and most of· the Keyser and higher beds have 

b~en laid bare by the cuttings of the railway 

company. 

The section was -studied by I. C. White1 in 

1883 and referred to by him as the Georgetown 

section. He recognized in it the Oriskany 

sandstones; the Stormville shale, 100- ·feet 

thick; the Stormville and Bastard limestones, 

with a combined thickness of 135 fee.t; the 

Bossardville beds, with a thickness of 115 

feet; and, at the. base, the Salina. The sub1 Pennsylvania Second Geol. Survey Rept. G7, p. 93, 1883. 
HELDERBERG LIMESTONE OF CENTitAL PENNSYLVANIA: 217 

joined section does not include any of White's 

·Oriskany, the uppermost units, referred to the 

New Scotland, representing part of his Sto:qn~ 

ville shale. · The beds forming the Coeymans 

and Keyser membeFs of the Helderberg are 

his Stormville and Bastard limestones. The 

Tonoloway portion of the section is all included 

in his Bossardville. 

The Tonoloway-Keyser contact is placed at 

the base of the nodular beds. The KeyserCoeymans contact is marked sharply by the 

very sandy limestone forming the Coeymans 

member. This limestone contains few fossils, 

but its stratigraphic position and its lithologic 

agreement with the Coeymans of other sections justify its reference to this member. At 

the Emrick & Lebo quarry, 4 miles northeast 

of Dalmatia . and about a quarter of a mile 

south of Mandata (Bull Run), this sandy limestone-is about 6 feet thick and is overlain by 

shale carrying S pirijer macropleur'L!s. The 

Coeymans-New Scotland contact is placed at 

the base of the concealed unit, which carries 

loose on its surface numerous New Scotland 

fossils. / 

Section 1 mile south of Dalmatia. 

Helderberg limestone·: New Scotland limestone member·: 

Total 

Thick- thick- ness. ness. 

Concealed by wash, filled with 

yellow-brown ochery shale 

and much chert. Strophonella Feet. Feet. 

pun,ctulijera, Pelecypoda. . . . . . 6. 4 21. 6 

Shale, ochery yellow, fissile, 

fine grained. Bryozoa, Spirifer cyclopteris, Anoplotheca concava. . . . . . . . . . . .. . . . . . . . . . . 1. 5 1'5. 2 

Concealed interval; clay and 

soil filled with fragments of 

weathered brown ochery shale 

and sandstone; a little chert 

observed. Pholidops ovata (c), 

Dalmanella perelegans (c), Stropheodonta beckii, Chonetes cf. 

C. -hemisphericus, Spirifer perlamellosus, Spirijer cyclopterus, Anoplotheca concava (a), Meristella sp., Phacops logani? 

Ostracoda, loose on the surface. 13. 7 13. 7 

Coeymans limestone member: 

Limestone, coarse, dark gray, 

very sandy; weathers to re- semble a brown ferruginous 

sandstone; contains black 

chert lentils; no fossils observed ..... -................ . 

21. 6 

2.0 2.0 

2. o 1 

Section 1 mile south of Dalmatia-Continued. 

Helderberg limestone-Continued. 

Keyser limestone member-Contd. 

Total Thick- thick- ness. ness. 

Limestone, banded, fine grained, 

with conchoidal fracture, in 2 

to 4 inch layers, separated by same thickness of weathered 

yellow shale; contains near top some large, irregular curly masses ( 18 inches in diameter), 

which look somewhat like Feet. Feet. 

Stromatopora........ . . . . . . . . . . 10. 3 139.· 8 

Limestone, blue-gray, conchoidal, fine grained, in four layers 

(8, 10, 3, 10 inches), separated by platy yellowish limestone. . . . . . . . . . . . . . . . . . . . . . . . 3. 3 129. 5 

Limestone, banded, fine grained, 

extremely platy; yellow on weathered surface, light gray on fresh fracture; calcite seam at top..... . . . . . . . . . . . . . . 5. 7 126. 2 

Limestone; blue-gray, fine 

grained, conchoidal, thin bedded (6 inches); scattered lentils of black chert (1 inch 

thick and 18 inches long); 

calcite sheet at 118.6 and 

top ......................... - 2. 9 120. 5 

Limestone, bluish, fine grained; 

conchoidal fracture; in thin 

layers (1 to 3 inches), with 

shale laminae between; calcite sheet at 111.6 and at top. 

Meristella sp., 107.6-116.6; 

Tentaculites gyracanthus, 106.1-

112.6; Pelecypoda, 106.1, 

107.6. ..•..................... 12. 1 117. 6 

Limestone, verY impure, dark, 

shaly; carries irregular ~enses 

(2 to 3 inches in diameter) of 

pure bluish limestone; in 

bulk about half of each; w~athers to a light-gray color; 

calcite seam near base and at 

top. Meristella praenuntia (a), 99.6-102~6; Pelecypoda, Tentaculites gyracanthus, 99.6-

104.6 ....... -................. 6. 0 105. 5 

Limestone, pure, thin bedded, 

fine grained, bluish gray; con- choidal fracture; some · fossilif- erous lenses. Jferistella sp., · 98.6 ...................... . .... 1.7 99.5 

Limestone, coarse, blue-gray, crystalline, in irregular 2 to 3 

inch layers with light-gray 

shale laminae between; calcite sheet near top. Uncinulus 

keyserensis, Meristella praenuntia, Tentaculites gyracanthus, and Pelecypoda throughout; Bryozoa, Camarotoechia 

litchfieldensis, Whitjieldella cf. 

W.nucleolata,94.9............ 3.2 97.8 

Limestone, shaly, weathered, 

impure, dark gray; contains a few pure crystalline streaks; 

calcite sheet near top. Meri;. 

stella sp., Tentaculites gyracanthus, 93.6.................. . . . . 1. 9 94.6 
218 SHORTER CON RIBUTIONS TO GENERAL GEOLOGY, 1917. 

Section 1 -nile south of Dalmatia-Co:rrtinued. 

Total 

Thick- thick- ness. ness. 

-~---------------1--- ---

Helderberg limestone-Continued. 

Keyser limestone member-Contd. 

Limestone, coarse, crystalline, bluish gray, profusely fossilif- erous. Uncinulus keyserensis'!, 

Meristella praenuntia (a), Tentaculites gyracanthus, Pelecypoda, Bryozoa, Ostracoda, 

92.6 ........ _._ ............... - Limestone, solid, impure, dark 

gray; weathers yellow; con- tain&many streaks of pure finegrained limestone; calcite 

sheet at top. Whitfieldella'! 

prosseri, Meristella praenuntia 

(a), Tentaculites gyracanthus 

(a), Orthoceras sp., Pelecypoda, 

90.6 ................... -.- ... -- Limestone, coarse, crystalline, 

blue-gray; weathers light 

gray; profusely fossiliferous. 

Uncinulus keyserensis, Meristella praenuntia (c) throughout; Bryozoa, Atrypa rugosa?, 

Whitfieldella cf. W. nucleolata, Pelecypoda, 89.6; Uncinulus nucleolatus, Rensselaeria mu- tabilis (c), 88:6 .............. . Limestone, impure, medium 

gray, fine grained; weathers 

brown and has a number of 

thin conchoidal purer lenses 

which weather light gray; calcite sheet at base; solid unit as a whole. Tentaculites gyracanthus throughout; Ostracoda, 85.6 .. . ............ . . .. . . Limestone, blue, crystalline, in 

lenses 1 to 2 inches thick, with irregular shaly layers 

between; 'shale weathers yellow; limestone gray. . Meristella p~~raenuntia, Tentar.ulites gyracanthus 1 Ostracoda, 

throughout; Rensselaeria mu- tabilis, 82.1 ... . .......... . ... . Limestone, in four layers; blue, 

conchoidal, fine grained; crystalline fossiliferous streak at 

80.6; ·shale laminae between 

layers. Meristella praenuntia, 

Tentaculites gyranthus, 80.6 .... Shale, calcareous; light gray and 

yellow on weathered surface, 

dark gray on fresh fracture; 

has a diagonal ' 'shear " parting and is interleaved with numerous thin beds of pure 

blue-gray crystalline limestone. 

Rensselaeria mutabilis (a), 78.8; 

Rensselaeria keyserensis, Tentaculites gyracanthus, Pelecypoda, 78.8, 77.3; Pholidops 

ovata, Dalmanella sp., S chuchertella prolifica, Rensselaeria 

(Beachia) proavita (a), Meristellasp. ?, Bryozoa, 77.3 ...... . Limestone, solid; blue, fine 

grained ; conchoidal fracture; 

apparently very pure; calcite 

sh_eets at top, at base, .and in , middle ...................... . 

Feet. 

0.4 

2.0 

2.3 

3.9 

2. 2 

2. 5 . 

4.0 

Feet. 

92. 7 

92.3 

90.3 

88.0 

84.1 

81. 9 . 

79.4 

75.4 

Sectio.n 1 mile south of D::tlmatia-Continued. 

Total 

Thick- thick- ness. ness. 

Helderberg limestone-Continue9.. 

J{eyser limestone· member-Contd. 

Shale, calcareou~; light gray and - yellow on weathered surface, 

dark on fresh fracture. Spirifer vanuxemi prognosticus, Tentaculites gyracanthus, throughout; Bryozoa, Orbiculoidea 

cf. 0. numula, Rensselaeria keyserensis; Orthoceras sp., 71.1; 

Pelecypoda, 71.1, 70.3; 

Pholidops ovata, Ostracoda, 

70.3 (a), 67.0; Meristella praenuntw?, Holopea antiqua?~_ 

Orbiculoidea sp., 70.3; Camarotoechia ·Sp.?, Rensselaeria mu- Feet. 

tabilis, 67.0.................. 6. 5 

Limestone, solid but impure; 

dark gray and fine grained on fresh fracture, but very light . gray and yellow on weathered 

surfaces; calcite seam at top • with a slickensided surface. 

Orbiculoidea cf. 0. numula, 

Coelidium dalmatiae , Rensselaeria mutabilis, 65.6; Pelecypoda,65.6, 63.6; Orthocerassp. , 64.6, 63.6; Meristella sp.?, Ostracoda, 63 .6. . . . . . . . . . . . . . . . . . 3. 0 

Shale, calcareous, very platy 

and papery; weathers yellowish and light gray; contains a number of solid but impure 

limestone layers (2 to 6 inches 

tl?ick); s~~ly pa~~ssho~ much 

dmgonal shear partmg..... 7. 5 

Shale, calcareous, light gray, 

with diagonal ' 'shear " parting. ·......................... . 5 · Limestone, massive, somewhat 

nodular, impure, dark gray, 

with several crystalline fossiliferous seams. Dalmanella 

concinna, Leptaena rhomboidalis, Stropheodonta bipartita, 

Atrypa reticularis, Ostracoda, 

throughout; Bryozoa, Camarotoechia sp. , Spirijer 'Vanuxtmi prognosticus, Proetus sp. ?, Calymene camerata, 55.1; Camarotoechia litchfieldensis, Uncinulus keyserensis ?, Meri.stella 

sp., Merista typa, 52.2.......... 3. 9 

Limestone, sin~le layer, finely 

crystalline, hght bluish; con- choidal fracture; calcite seam at top. · }rferistella sp.?, 51.3. . .. . 3 

Limestone, massive, somewhat 

nodular, impure, dark grar., 

with several crystalline fossiliferous seams. , Byrozoa, Spirifer vanuxemi prognosticus, . throughout; Leptaena rhomboidalis, Stropheodonta bipartita, Strophonella geniculata, 

Camarotoechia litchfieldensis, 

Pelecypoda, Ostracoda, 48.2. . . - 4. 0 

Limestone, single layer, finely 

crystalline, light bluish; c~nchoidal fracture; ~-inch calcite seam at top. Spir~fer van- uxemi prognosticus, 46.9. ···: ... . . 4 

Feet. 

72.8 

66.3 

63.3 

55.8 

55.3 

51.4 

51.1 

47.1 
liELDERBERG LIMESTONE OF CENTRAL PENNSYLVANIA. 219 

Section 1 mile south of Dalmatia-Continued. S~ction J_mile south of Dalmatia---,-Continued. 

~- -------

I ThickTotal Thick- Total 

ness. thick- ness. thick- ness. ness. 

! ------

·Helderberg limestone-Continued. . Helderberg limestone-Continued. 

Keyser limestone member-Contd. Keyser limestone member-Contd. 

Limestone, massive, dark gray, Limestone, massive, nodular, 

crystalline, not distinctly nod- darkgray; conchoidal fracture. 

ular; fossils show on weathered Camarotoechia? !J1mellata 

surface sparingly. Leptdena Feet. Feet. throughout; Bryozoa, Spirijer Feet. Feet. 

rhomboidalis, 45.7 ........... __ 2. 2 46. 7 sp., 5.0 ..................... :- 5.5 5.5 

Limestone, massive, nodular, impure, dark gray, coarsely crys- 139.8 

talline layers; calcite seams persistent parallel to bedding Tonoloway limestone: 

at 44.5, 42.4. Bryozoa, 41.6 Limestone, dark gray, pure, crystalto 44.4; Orbiculoidea sp., line; solid bed; shows a rude columSpirijer vanuxemi prognosti- nar character in places; has everycus, Uncinulus sp., Proetus where one or two !-inch calcite 

sp., 44.4; Stropheodonta bi- seams at base. Spirijer -lceyserenpartita, 40.6 to 44.4; Rens- sis, 1.4; Leperditia sp., Ostracoda, 

selaeria mutabilis, 44.4, 42.6; -2.4 .....................••.. · ... 3.2 -3.2 

Uneinulus keyserensis, 31.7 to Limestone, thin bedded (1 to 3 

42.6; Rensselaeria (Beachia) inches); beds do not seem to sepaproa·vita, Whitfieldella cf. W. rate, and unit looks rather massive; 

nucleolata, Meristella sp., Pele- dark gray, fine . grained, con- cypoda, Calymene camerata, choidal in part; crystalline in part; 

Camarotoechia litchfieldensis, very pure. Leperditia throughout; 

42.6; Dalmanel!n, cf. D. perele- Camarotoechia lamellata, -5.4, 

gans, 41.6; Atrypa reticularis, -11.4, -21.4; Camarotoechia litch38.6; Orthocerassp., 37.1. ____ . _ 8. 1 44.5 fieldensis, -5.4, -11.4; Spirijer 

Limestone, massive, nodular, im- keyserensis, -5.4 to -15.9; Ostrapure, medium gray; nodules coda, -:-12.4, -14.9 .............. _ 20.4 -23.6 

~Ire, I?Iatri~impure and shaly, Limestone, thin bedded (3 to 6 

avoS'tt,es, Ill large heads, inches), dark gray, in part coarsely 

abundant in lower 7 feet; crystalline. Camarotoechia? lamelLeptaena rhomboidalis, 36.4, · lata, Leperditia sp., Ostracoda, 

1.7 -25.3 ~ 34.6; Dalmanella sp., Steno- -24.4 ..................... -•• -.-- schisma deckerensis?, Atrypa Limestone, massive, dark gray, crysreticularis (a), Rhynchospira talline. Leperditia sp., -25.4?, 

globosa, Coelidium dalmatiae, -27.0, -29.0 .......... -- ......... 4. 7 -30.0 

34.6; Favosites sp., 30.6-25.6; Limestone, impure - looking, dark 

Dalmanella concinna, Stropheo- gray, banded; much very fine, dis-

• 

donta bipartita, Stenoschisma seminated pyrite; purer than the 

formosa, Pelecypoda, 30.6; next lower unit ...... __ ..... _ .... _ 2.5 -32.5 

Orthoceras sp., 27.6; Schuchert- Limestone, impure, gritty-looking, 

ella sp., Camarotoechia litch- dark gray, with a pronounced difieldensis, Spirijer modestus, agonal parting; looks as if it had 

23.7 .......................... 12.8 36.4 been sheared.~------ ............ _. 3.6 -36.1 

Limestone, massive, nodular, Limestone, massive, banded; pure, 

ifimpure, much like unit above; dark gray; shows columnar struccalcit!e seams, HU, 23.6; ture ......................... ~ ... 2.4 -38.5 

layer of Stromatopora, 3 to 6 Limestone, shaly, dirty gray; irreguinches, 15.1-15.6; Dalmanella Iar, cl.iagonal "shear" parting; 1 

sp., Schudl,ertelln, deckerensis, inch of calcite at base ............ _6 -39.1 

Chonetes jerseyensis, Steno- Limestone, massive, banded, pure, 

schisma deckerensis, 22.6; Caly- gray; shows columnar structure in 

• mene camerata, Carnarotoechia places. Leperditia sp., -39.4, 

litchfieldensis, 22.6, 16.6; Spiri- -42.8 ............................ 4. 7 -43.8 

fer modestus, 22.6 (a), 13.6?; Limestone, alternating shaly and 

Camarotoechia? lamellata, 13.6- pure in l-inch courses ... -......... . 9 -44.7 

18.1; Spirijer sp., 16.6; Ostra- Limestone, massive, dark gray, pure, 

coda, 16:6, 13.6; Pelecypoda, banded ............ __ ............. .8 -45.5 

15.6, 13.6; Spirijer vanuxemi, Jjmestone, same, not banded. Leper-

-46.1 • 12.6 ........................ -. 12.3 23.6 ditia sp., -45.9 .............. -... .6 

Limestone, massive, nodular, Limestone, massive, dark gray, pure, 

dark gray, impure: i-inch seam banded ................. -......... 1.7 -47.8 

of calcite at base; when weath- Limestone, dirty gray, sandy-lookered looks thin bedded. Cama- ing but contains no sand; shows 

rotoechia? lamellaw, Ostracoda everywhere an irregular diago-

(c), throughout; Spirijer van- nal parting as if it had been 

-48.5 • uxemi, Tentaculites gyracan- sheared ........................ -- .7 

thus, 8.6; Camarotoechia litch- Limestone, pure, platy, dark gray ... LO -49.5 

fieldensis, Spirifer modestus?, Limestone, very massive, blue-gray; 

7.6: Leperditia sp., 6.6 ....... _. 5.8 11.3 shows no banding .... _ ............ 3 .. 2 --52.7 
220 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

Section 1 mile south of Dalmatia-Continued. 

Tonoloway limestone-Continued. 

Limestone, pure, very platy, laminated; has some geodal calcite layers; shows distinct rude columnar 

structure in places ............... . Limestone, pure, dark gray, fine 

grained; conchoidal fracture ...... . Limestone, pure, dark gray, very 

platy and laminated . .. .... .... _ .. Limestone, light gray, fine grained; · conchoidal fracture; has black 

layers which mottle its fract\lre 

surfaces ..................... _ . _ .. Limestone, platy; dark, impure, 

passing into weathered yellow cal- careous shale above .. · ..... _ ...... . Limestone, pure, thin bedded (3 to 

6 inches), blue-gray .............. . Shale, calcareous, weathered, yel- . low, with some geodal calcite lay- ers and several thin limestone 

streaks .......... : ............ _ . _ Limestone, fairly pure, but thin 

bedded and platy_ .............. . Limestone, impure, banded, platy, 

light gray; curly layer near base 

contains small radiating masses of 

strontianite ................... _. __ Shale, weathered, yellow ........... . Limestone, curly, dull gray, fine 

grained, with much disseminated 

pyrite: ......... : ............... :- Limestone, heavy, blue-gray, pure, 

fine grained; shows some banding .. Limestone, impure, shaly-looking; 

weathers into thin laminae; perhaps a little purer in middle 3 feet. 

Limestone, pure, dark gray, thin 

bedded (1 to 2 inches) ...... _ .... . Limestone, impure, shaly, dark gray. 

Limestone, fairly pure, dark gray, 

thin bedded (.l to 2 inches) ....... . Concealed by quarry debriR. 

Total 

Thick- thick- ness. ness. 

Feet. Feet. 

6. 9 -59.6 

1.0 -60.6 

1.0 -61.6 

.8 -62.4 

3.2 -65.6 

1.0 -66.6 

6. 7 -73.3 

6.2 -79. ·5 

2.2 -81.7 

.6 -82.3 

.2 -82.5 

3.0 -85.5 

12.0 -97.5 

.9 -98.4 

l. 5- -99.9 

2.5 -102.4 

102.4 

In-this section the characteristic faunas of 

the Chonetes jerseyensis and Favosites helderbergiae var. praecedens zones are well developed, 

and a number of subzones are recognizable. 

The Tonoloway formation contains near its 

top the zone of Spirijer keyserensis, which is 

recognized at -the same horizon in Maryland. 

SELINSGROVE _JUNCTION. 

The limestone described by tl}e Second Geological Survey of Pennsylvania as the Lewistown limestone or' "Formation No. VI" is exposed along the Northern Central Railway 

_ north of Selinsgrove .Junction. Susquehanna 

River cuts across an anticlinal arch at this 

point, presenting a section which begins 1 mile 

abo.ve the railway station and extends approximately I! miles toward the north. Both limbs 

of the anticline_ were studied, but only the 

' southern half is described here. The concealed 

unit forming the center of the arch is probably 

of Wills Creek age. The succeeding 148 feet of 

beds contain only Leperditia, rare Rhynchospira, and Ectomaria and havethe characteristic_ 

lithology of the Maryland Tonoloway, with 

which they are probably to be correlated. The 

overlying beds are richly fossiliferous and embrace the Keyser, Coeymans, and New Scotland 

members of the Helderberg formation. These 

are succeeded by the Oriskany. formation. No 

indication of the presence of the Becraft member of the _ Helderberg was seen. The exposures here are excellent and afford the hestand 

most continuous section ·of these formations 

observed by the writer. 

The two sections were measured by I. C. 

White, 1 who refers the lowest part to the Salina, 

and the overlying beds to the Bossardville, 

Bastard limestone, Stormville limestone, Stormville shales, and Ori~kany. It is probable that 

the upper 114 feet of the Tonoloway formation 

described in the. subjoip.-ed section represents 

White's Bossardville;· the beds from the base 

of the Keyser to the base of the calcareous 

shales of the New Scotland represent his Bastard and Stormville limestones; and the shaly 

beds above the New Scotland limestone and 

extending up to the top of the section represen~ 

his Stormville shales. On the north side of the 

axis there is exposed above the horizons shown 

in the southern section about 25 feet ofcoarse 

cherty ferruginous sandstones, which are probably White's. Oriskany beds. 

The. Helderbergian portion of the s~ction was 

exammed also by C. K. Swartz 2 in 1913. He 

recognized in it the equivalents of the Maryland Keyser and referred the underlying beds 

to· the Tonoloway. 

- As fossils are comparatively rare in the beds 

.lying immediately above the New Scotland 

.limestone, the position of the New ScotlandOriskany contact is open to question. The 

writer places it tentatively at the base of the 

lowest distinctly sandy beds. 

1 Pennsyl~ania Second Geol. Survey Rept .. G 7, p. 93, 1883. 

2 Maryland Geol. Survey, Lower Devonian, p. 108, 1913. 
' 

HELDER.BERG LIMESTONE OF CENTRAL PENNSYLVANIA. 221 

Section on south side of anticlinal axis at Selinsgrove Section on south side of anticlinal axis at Selinsgrove 

Junction. Junction-Continued. 

Total 

Thick- thick- ness. 

Oriskany formation: . Sandstone, cherty, fine grained, fer- Feet. 

ruginous ... c.. • • • • • • • • • • • . • • • . . . . 4. 0 

Concealed.. ....................... 10. 9 

Sandstone, cherty, fine grained, ferruginous. Anoplotheca ftabellites, 

39.5, 32.5........................ 7.1 

Concealed. 

Limestone, dark gray, fine grained, 

very arenaceous; numerous l-inch 

chert lentils....................... 12. 0 

Shale, dark brown. 

Limestone, dark gray, fine grained, 

very arenaceous; numerous l-inch 

chert lentils. Spirifer sp......... 15. 0 

Shale, very sandy; breaks into flat 

fragments; dark gray to chocolatebrown............................ 5. 4 

54.4 

Helderberg limestone: 

New Scotland limestone member: 

Limestone, very impure, dark 

gray, mottled with yellow; 

weathers into small irregular f~~ments, some of which are sihceous . . . . . . . . . . . . . . . . . . . . 8. 6 

Lime shales, dark gray, with a few thin limestone layers; 

weathers to thin laminae...... 35. 8 

Limestone massive, crystalline, 

arenaceous, dark gray. Lingula sp., 6.0, 12.0; Dalmanella 

pe:relegans, Leptaena rhomboidalis, .Meristella sp., 4.3-9.0; 

Schuchertella woolworthana, 

6.0-9.0; Uncinulus nucleolatus, 

9.0; Eatonia medialis, 8.9, 9.0; 

Spirifer macropleurus, Spirifer 

perlamellosus, Phacops logani, 

Dalmanites sp., 9.0; Pelecypoda, Bryozoa, Ostracoda..... 9. 0 

Limestone, in large nodules 

(diameter 6 to 8 inches), em- bedded in a shaly matrix. 

Dalmanella perelegans, Schuchertella woolworthana, . Eatonia-medialis, Anoplotheca con- cava (a), 3.7 ............... _ . ; 4. 2 

57.6 

Coeymans limestone member: Limestone, fairly massive, 

coarse, blue-gray, arenaceous, 

interbedded with layers of 

black chert 3 to 4 inches thick; 

joint planes show large imperfect crystals of calcite and 

quartz. Pholidops ovata, Da-lmanella perelegans, Strophonella leavenworthana, Schuchertella woolworthana?, Gypidula coeymanensis, Atrypa reticularis, Leptaena rhomboidal is, 

Spirifer sp., .Meristella sp., , Phacops logani, Pelecypoda, I 

Bryozoa, Ostracoda ......... ~ 

3.6 

ness. 

Feet. 

54.4 

50.4 

39.4 

32.4 

20.4 

5.4 

57.6 

49.0 

13.2 

4.2 

3.6 

Helderberg limestone-Continued. 

Keyser limestone member: 

Limestone. thin bedded, (1 to 

3 inches), blue, fine grained. 

Leperditia sp., 201.9 ........ . Limestone, blue, fine grained, 

with conchoidal fracture; courses 6 to 12 inches, sepaarated by about the same thickness of gray calcareous 

and arenaceous shale ........ . Shale, yellow ................ . Limestone, heavy bedded, 

massive, impure, light gray, indistinctly laminated. _ ... -. Limestone, medium bedded, 

impure, light gray; a few 

layers very shaly and weathered; toward upper part the 

bedding planes weather out 

clearer and rock is laminated; 

not distinctly separated from 

underlying unit. Tentaculites gyracanthus, 154.9 ___ .. ... Limestone, thin bedded (1 to 2 

inches); some layers crystalline, pure, blue, fossiliferous; 

others impure and shaly. 

Tentaculites gyracanthus (a). 

Pelecypoda (a), throughout; 

Camarotoechia litchfieldensis?, 

Whitfieldella c£. W. nucleolata 

(a), Meristella praenuntia, Ostracoda, 150.4 ......... _ .... . Limestone, finely crystalline, 

light bluish gray, in two solid 

beds separated by 8 inches of 

shaly limestone. Tentaculites gyracanthus scattered 

throughout the heavy beds; 

abundant in the shaly layer .. Limestone, pure, fine grained, 

thin bedded (3 to 8 inches), 

blue ; breaks with conchoidal 

fracture, though a few layers are platy and impure; layers are separated by thin shale. 

Tentaculites gyracanthus 139.4-

144.9; Pholidops ovata, .Meristella praenuntia (c), Holopea 

sp., Orthoceras sp., 141.1; Pelecypoda, 143.9, 144.9; Ostracoda, 144.9_ ................ . Shale, weathered, yellow, filled 

with small lenses of crystalline blue limestone crowded 

withSchuchertella prolifica (a), 

Rensselaeria obtusa, Rensselaeria mutabilis (a), Pholidops 

ovata, Uncinulus nucleolatu.~, 

Uncinulus lceyserensis?, Ten- taculites gyracanthus, Ortho- ceras sp., Pelecypoda, Ostracoda ....................... . Limestone, medium bedded 

(10 to 12inches), fine grained, 

blue, with conchoidal fracture; platy in parts; a few fossiliferous lenses. Tentaculites gyracanthus (c) throughout; Whitfieldella c£. W. nuTotal 

Thick- thick- ness. 

Feet. 

5.5 

6.9 

1.4 

18.3 

17.i 

3~5 

3.2 

7.8 

2.1 

ness. 

Feet. 

202.3 

196.8 

189.9 

188.5 

170.2 

153.1 

149.6 

146.4 

138.6 
~22 SHORTER · CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

S ection on south side of anticlinal axis at Selinsgrove Section on south side of anticlinal axis at Selinsgrove Junction~Continued. Junction-Continued. 

Helderberg limestone-Continued. 

Keyser limestone member-Contd. 

cleolata, 132.9; Rensselaeria 

mutabilis, Rensselaeria keyserensis, Pelecypoda, Ostracoda, 

129.9 ....................... . Limestone, very E!haly, light 

gray to yellow, withafewthin 

pure streaks. Orbiculoidea cf. 

0. numula, Pholidops ovata, Rensselaeria mutabilis, Ortho- ceras sp., Bryozoa; Pelecypoda, Ostracoda, throughout; 

Spirifer vanuxemi var. prognosticus, 119.9-125.9; Meristella praenuntia, 125.9; Tentaeulites gyracanthus, 122.9; 

125.9; Unci'{l,ulus nucleolatus, · 117.9-124.9; Nucleospira elegans, 121.9; Whitfieldella cf. 

W. · nucleolata, 119.9; Dalmanella clarki, Stenoschisma · formosa, Camarotoechia litchfieldensis, Holopea antiqua, 

110.9; Calymene camerata (a), 

110.9; Schuchertellasp., 110.9, 

114.9; Leperditia sp., 121.9 ... Limestone in 3 to 6 inch courses separated by about 18 inches 

of lime shales. The shales are light gray to yellow; the limestones are in part fine grained, 

in part crystalline, Layer 

With much pyrite, 103.7. 

Dalmanella concinna, Stro- pheodonta bipartita, Spi?·ifer vanuxemi var. prognosticus, Pelecypoda, throughout; 

Rensselaeria mutabilis, Caly- mene camerata, Orthoceras sp., 

Ostracoda, 108.9; OrbiculQidea 

cf. 0. numula, Spirijer van- uxemi'!, Cyclonema sp., Leperditia sp., 106.9; Stenoschisma 

formosa?, 104.9; Sc(l,uchertella 

sp., 103.9; Leptaena rhomboidal is, Camarotoechia litch.fieldensis, Atrypa reticularis, Bry- , ozoa, 102.9 ................. . Limestone, extremely massive; 

nodular character not nearly so distinct as in the unit below; coarse . crystalline lenses 

abundant. Leptaena rhomboidalis, Atrypa reticularis, 

throughout; Holopea antiqua, 

101.9; Dalmanella concinna, 

Proetus sp., 97.9; Orthoceras 

sp., Bryozoa, 96.4; Spirijer 

vanuxemi var. prognosticus, 

Schuchertella deckerensis '!, 

Goldius barrandi, 93.9; Pelecypoda, 99.9; Ostracoda, 97.9, 

101.9 ....................... . Limestone, extremely massive, 

nodular, dark; nodules pure; 

matrix earthy, gray; basal 2 

feet has in many places a rude 

columnar structure and is not 

nodular; upper 2 feet only 

faintly nodular. Dalmanella 

Total 

Thick- thick- ness. 

·Feet. 

7.8 

19.8 

6.6 

9.0 

ness. 

Feet. 

136.5 

128.7 

108.9 

102.3 

Thick- Total 

ness. ~~:.-

-------------- --------

Helderberg limestone-Continued. · Keyser limestone member-Contd. · concinna, Leptaena rhomboidalis, Atrypa reticularis, 88.9, 

81.9; Stenochisma formosa, 

Camarotoechia litchfoldensis, 88.9; Chonetesjerseyensis, 87.9, 81.9; Meristella pmenuntia?, 

87.9; Schuchertella deckerens1:S, 

Gypidula coeymanensis var .. prognostica, Stimoschisma 

deckerensis, Ectomaria sp., Proetus protuberans, 81.9; Bryozoa, 81.9-90.9; ·Pelecypoda, 

85.9, 81.9 ....••... " ......... . Limestone, impure, nodular; 

looks sandy but contains no sand ....................... . Limestone, rather heavy bedded, blue-gray, with con- choidal fracture; nodular 

character pronounced. Stropheodonta bipartita, Schuchertella deckerensis, Chonetes 

jerseyensis. (c), Camarotoechia? 

lamellata, At1·ypa recticularis, 

Spirifer vanuxemi, Orthocems 

cf. 0. perstriatum, Calymene 

camerata, Pelecypoda, Ostracoda, 77.9 .................... . 

Limestone, thin bedded, otherwise like the unit above. 

Camarotoechia? lamellata 

Calymene camerata, Ortho- ceras sp., Ostracoda . ......... . Limestone, very nodular, thin 

bedded, fine grained, dark 

gray. Orthoceras sp., 70.9 ... . Limestone, very nodular, more or less impure, dark gray. 

Some benches (52.9-55.9, 

58.9-60.9, 63.9-65.9) much more shaly than the remainder and weathers back faster. 

No other bedding .noticeable. 

Ostracoda and Bryozoa, 

throughout; . Favosites sp., 

64.9, 60.9; Stenoschisma formosa, 63.9?, 60.9; Schuchertella deckerensis, 60.9, 51.4; 

Schuchertella interstriata?, 

Atrypa reticularis, Orthoceras 

sp., 60.9; Calymene camerata, 

60.9, 54.9; Chonetesjerseyensis, 

54.9, 49.9; Camarotoechia'! 

lamellata, 54.9, 51.4; Camarotoechia litchfieldensis, · 54.9, 

49.9; Rhynchospira formosa, 

53.9, 49.9; Rhynchospira globosa var., Dalmanella sp., 

51.4; · Spirifer modestus, Ectomaria minuta, 49.9; Pelecypoda, 52.9 .................. . Limestone, nodular, dark gray, 

fine grained; impure looking on fresh fracture; in places 

inseparable from the unit 

below, but apparently not a stromatoporoid bed .......... 1 

Limestone, made up entirely of j 

stromatoporoids ...... . ....... . 

Feet. 

13.6 

1.2 

3.4 

3. 2 

4.0 

1.9.4 

3.0 

6.0 

Feet. 

93.3 

79. 7 

78.5 

75.1 

71.9 

67.9 

48. 5 

45.5 
HELDERBERG LIMESTONE OF CENT'RAL PENNSYLVANIA. 223 

Section on south side of anticlinal axis at Selinsgrove Section on south side of · anticlinal axis at Selinsgrove 

Junction-Continued. Jun0tion-Continued. 

Helderberg limestone-Continued. Keyser limestone member-Contd. 

Limestone, very nodular, fine 

grained, thin bedded, bluish 

gray. Bryozoa throughout; 

Cama1·o toechia? lamellata, 

38.9, 36.9; Spirifer modestus, 

Ostracoda, 38.9; Schuchertella 

deckerensis, 36.9; Rhynchospira 

globosa var. , 35.9, 34.9 ...... . Limestone, single bed, dark · gray, fine grained, with con- choidalfracture; very distinct 

along exposure; not nodular. 

Limestone, thin bedded, dark 

gray, nodular, impure. Cama- ro~chia? lamellata, Ostracoda, 31.9; Leperditia sp., 

Bryozoa, 30.9 ....... . ........ . Limestone, massive, blue-gray, 

somewhat nodular; bounded 

where measured by prominent bedding planes. Spirifer vanuxemi (a), Rhynchospira 

globosa var. (a), Ostracoda, 

Bryozoa, 27 .9, 25.9; Schuche?·tella deckerensis (a), Chonetes. 

jerseyensis, Spirifer modestus, 

Camarotoechia sp., Tentaculites gyracanthus, 25.9; Ortho- ceras ~p., 24.9 .............. . . Limestone, thin bedded (l-inch 

course."!), with shaly laminre 

between the layers; very nodular. Some layers dense, 

bluish gray, conchoidal; 

others subcrystalline; others 

earthy. Camarotoechia? lamellata, Spirifer vanuxemi, Rhynchospira globosa var., Spirifer 

rrwdestus, Tentaculites gymcanthus, Ostracoda, Bryozoa , throughout; Schuchertella 

deckerensis (a), 16.9-23.9; 

Meristella sp.?, Camamtoechia 

litch.fieldensis, . Spirifer octocostatus?, Pholidops ovata, 

Spirorbis sp., 19.9; Pelecypoda, 23.9, 19.9 ........... . Limestone, like the unit above 

but somewhat less nodular. 

Spirifer modestus?, Bryozoa, 

Ostracoda, 7 .9; Camamtoechia? lamellata, 7 .9, 4.4; Spinfer vanuxemi, 5.9, 4.4; Nucleospim sp., Leperditia sp., 5.9 .. Limestone like the above two 

units but less nodular still. 

Spirijer vanuxemi, Leperditia 

sp., throughout ............. . 

Tonoloway limestone: 

Limestone, massive, dark gray, con- choidal, fine grained; quarried for 

lime. Ectomaria minuta, -2.1; 

Leperditia sp., -3. L ............ . 

Limestone, thin bedded, medium 

gray, fine grained, with con- choidal fracture; quarried. Leperditia sp., -5.5 ............... . 

Total 

Thick- thick- ness. 

Feet. 

6.0 

.9 

2.5 

6.0 

15. 1 

5.2 

3. 8 

202.3 

4: 8 

3.0 

ness. 

Feet. 

39.5 

33. 5 

32. 6 

30. 1 

24. 1 

9. 0 

3. 8 

-4.8 

-7. 8 

Tonoloway limestone-Continued. 

Limestone, solid, dark gray, with 

conchoidal fracture; quarried just 

behind some old limekilns by a long cavelike opening. Lepe?·-

ditia throughout; Rhyncho~pira 

globosa var., -13.1. ............ . Concealed ........................ . Limestone, banded, dark, impure; 

has a very noticeable rude col- umnar structure ................ .' 

Limestone, dark gray, fissile, 

banded; contains large geodal calcite masses. In some parts a fine 

reticulated structure weathers out, 

due perhaps to silicification along . closejoints. Leperditiasp., -47.4. Limestone, light gray, siliceous, 

knotty ......................... . Limestone, rather platy, crystalline, light g,ray; many stringers 

and spots of calcite and some small geodes; weathers to thin 

lamin;:e ................. ~ ........ . Limestone, fairly pure, dark gray, fine grained, conchoidal; in thin ~enses separated by very _ shaly 

rmpure layers .................... . Limestone, very light gray to yel- . low; impure; conchoidal fracture ; 

apparently not much weathered . . Limestone, oolitic, siliceous, dark 

gray ......................... ----- Shale, laminated, light gray; thicker 

layers very light gray on fresh 

fracture ......................... . Layer. of irregular geodal calcite masses ........................... . . Shale, laminated, light gray ....... . Limestone, fairly massive, dark 

gray, fine grained; conchoidal 

fracture. Sand lens at -98.3. 

Leperditia sp. throughout ....... . . Limestone, platy, dark gray ....... . Limestone, light gray, knotty ...... . Limestone, very. platy, laminated; 

light gray on weathered surface; 

dark, impure, earthy on fresh 

fracture ; some layers finely crystalline ........................ . .. . Limestone, light gray; banded on weathered. surface; dark, con- choidal, resinous on fresh fracture ; 

solid bed; very fine grained ..... . Limestone, mostly concealed by 

talus ........ . .................. . Limestone, banded, gray; breaks 

into thin, papery fragments ..... . Limestone, banded, yellowish ..... . Shale, yellow, weathered ........ . . . Limestone, massive, banded, light 

gray .................. ············- Shale, brown, weathered ....... . .. . Limestone, blue, sandy-looking, massive ; apparently very impure ; 

breaks into irregular fragments .. . 

Concealed to the level of the railro,;td at the axis of the anticline, 

about 35 feet. 

Total 

Thick- thick- ness. 

Feet . 

8.2 

4.0 

14. 4 

17.0 

1.0 

10.0 

6. 5 

3.0 

.5 

11. 2 

. 5 

9.8 

8. 2 

1.0 

3.0 

4.8 

3.2 

io.o 

4. 0 

3.5 

2. 0 

6.0 

1.8 

7. 0 

148. 4 

ness. 

Feet. 

-16.0 

-20.0 

-34.4 

-51.4 

-52. 4 

-62.4 

-68.9 

-71.9 

-72.4 

-83.6 

-84.1 

-93.9 

:---102.1 

-103.1 

-106. ~ 

-110.9 

-i14.1 

-124.1 

128.1 

-131.6 

-133.6 

-139.6 

-141.4 

-148.4 
SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

The difference between this section and that 

at Grovania, only 19 miles to the northeast, is 

striking. The total thickness of the Keyser 

here is 202 feet; at Groyania, 122 feet. The 

Ohonetes zone is well developed in both, but 

differs greatly in thickness. The Favosites zone 

at Selinsgrove Junction carries an abundance of 

Tentaculites gyracanthus, S pirifer vanuxemi var. 

prognbsticus, and Rensselaeria mutabilis, but has 

very few corals and no ·stromato-por~ids; the 

same zone at Grovaniahas-a profusion of corals 

and stromatoporoids but almost none of the 

other forms usually common, carrying only 

Rensselaeria mutabilis, associated with a late 

form of Oamarotoechia? lamellata. The Coeymans at Selinsgrove Junction is a sandy cherty 

limestone; at Grovania it is a dense calcareous 

sandstone. 

GROVANIA. 

The section at Grovania was measured in the 

quarry f~rmerly owned by the Grove brothers, 

almost on the Columbia-Montour County line, 

about halfway between Danville and Bloomsburg. This quarry may be identified by the 

fact that it is the only one in the vicinity which 

is· drained by a tunnel. The exposures are very 

good and include the upper 40 feet of the Tonoloway, the Keyser, the Coeymans, and, in the 

tunnel, about 110 feet of shale and limestone 

representing probably all of the New Scotland,· 

the Becraft (if present), and perhaps part of the 

Oriskany. 

The section was studied in 1883 by I. C. 

White/ who gave a fairly detailed account of it. 

His description includes the following divisions: 

Oriskany sandstone; Stormville shale, 100 feet; 

Stormville conglomerate, 4 feet; Stormville 

limestone, 111 feet; Bastard limestone, 24 feet; 

Bossardville limestone, 105 feet. · He con-

. sidered these divisions equivalent · to those of 

the same name in the counties along Delaware 

River. However, as the fossils cited from the 

Delaware River area would make his· Stormville limestone . in part Coeymans and in part 

New Scotland, and his Stormville conglomerate 

and shale New Scotland, the correlation is incorrect. The evidence given below demonstrates that White's Stormville conglomerate 

of the Grovania section is Coeymans in age; his 

Stormville limestone is upper Keyser; and his 

1 Pennsylvania Second Geol. Survey Rept. G7, p. 88, 1.883. 

Bastard limestone is lower Keyser. · The upper 

part of White's Bossardville is represented by 

the Tonoloway. · 

· Section at Grovania. 

Limestones and shales of undetermined 

Total 

Thick- thick- ness. ness. 

age , but probably New Scotland and Feet. Feet. 

· Oriskany ......... . ..... -.... - -. . . . . . . 110 110 

Helderberg limestone: ·- · Coeymans limestom{ mem~er: 

Sandstone, coarse (grams ls to ! 

inch in diameter), white; base 

filled with crinoid stems and 

other fossils; contains some chert. Bryozoa, Leptaena 

rhomboidal is, Strophonella 

leavenworthana, Strophonella - punctilijera, Schuchertella woolworthana, Gypidula coeymanensis (a), Atrypa reticularis, Stropheodonta arata, Phacopslogani, Ostracoda, Pelecypoda, 1.0 _ _ _ _ 3. 0 3. 0 

3.0 

Ke~er limestone member: 

Limestone, irregular, crinoidal, dark blue ... ---"--_ ........ _._. 1. 6 122. 5 

Limestone, compact, light blue, 

heavy bedded; conchoidal 

fracture . _ . _ . ___ . _______ - .. __ . . 5. 5 120. 9 

Limestone, laminated, light gray 

to yellowish, platy. Has some solid 6-inch layers of light-gray 

rock, but for the most part is 

rather shaly. Barren of fossils. 36. 4 115. 4 

Limestone; a peculiar pebbly 

stromatoporoid makes up whole 

ofrock...... . . . . . .. .. . . . . . . . . . 3. 0 79. 0 

Limestone, blue, pure, with 

many transverse calcite seams; · massive and somewhat nodular; composed almost entirely 

of stromatoporoids; has ~-inch 

layer of shale at top. _ ..... _ . _ _ 3. 4 76 .. 0 

Shale, yellow .......... _......... . 2 72.6 

Limestone, composed almost en- tirely of stromatoporoids .. __ . .. 5. 6 72. 4 

Shale; blue-black, with one or two limestone layers. Limestone at 65.1 is arenaceous. Camarotoechia? lamellata, 65.1, 63.1 (a); Rensselaeria mutabilis 

(a), 65.1; Atrypa rugosa ?, 63.1, 

62.1; Favosites sp., Spirorbis 

laxus; Pholidops ovata (c), S chuchertellasp.?, Camarotoechia 

litch.fieldoosis?, Rensselaeria keyserensis (a), Spirijer vanuxemi 

prognosticus, Whit.fieldella cf. 

W. nucleolata, Ostracoda _(a), 

62.1.------------------------- 4. 6 66. 8 

Limestone, crystalline, blue, 

pure. Favositessp............. L 3 62 .. 2 

Limestone, crystalline, blue, 

pure; many transverse calcite ·seams .. ______ .. ___ .... , ..... -- . 8 60. 9 
1-

HELDERBERG LIMESTONE OF ' CENTRAL PENNSYLVANIA. 225 

Section at Grovania-Continued. 

Helderberg limestone-Continued. 

Keyser limestone member-Contd. 

Limestone, crystalline, blue, 

pure, massive; weathers thin 

bedded; has rriuch black shale. 

Stromatoporoids throughout; 

Favosites sp., Halysites catenulatus (a), 57.1, Camarotoechia 

litchfieldensis, 55.L ........... . Limestone, crystalline, blue, 

pure, massive; numerous trans- verse thin calcite seams; 

weathers thin bedded. HaZysites catenulatus throughout, 

abundant at 51.1-A8.1; Favosites sp., Cladopora rectilineata, 

Uncinulus nucleolatus?, 44. L .. Limestone, heavy bedded, light 

gray; has great masses of vein 

calcite. Favosites sp., Cladopora rectilinecita (a), . Halysites 

catenulatus(a), Bryozoa, Camarotoechia litchfieldensis, Rhynchospira globosa?, 42.L ....... . Limestone, crinoidal, relatively 

impure .............. "' ...... . Limestone, light gray, nodular; 

much shalier than the beds beneath; weathers easily; "Bastard" limestone of the quarry- men. Rhipidomella emarginata 

31. 2; Stropheodonta bipartita, Stenoschisma - formosa, 32.1-

19.9; Spirijer vanuxemi var. prognosticus, 31.1, 24.0; Ortho- ceras sp., 31.1-23.0; Leptaena 

rhomboidalis, Atrypa reticularis, 28.1-13.4; Favosites sp. , 26.0, 25.0; stromatoporoids 

25.0; Uncinulus nucleolatus?: Eotomaria sp., Schuchertella 

deckerensis, Pelecypoda, Bryozoa, 25.0-23.0; Orthostrophia 

strophomenoides, Spirijer octocostatus, 25.0-17.9; Dalmanella 

concinna, C!fonetes jerseyensis, 

Camarotoechw? lamellata, 25:0-

12.3; Coelidium pennsylvanicum, 25.0; Stenoschisma deckerensis, Merista typa, 24.0, 23;0; 

Calymene camerata, 24.0, 12.3· 

Spirorbis laxus, Camarotoechi~ litchfieldensis, Tremanotus profundus ?, Loxonema fitchii?, 

23.0; Strophonella lemJenworth- ana var., Leperditia sp., 22.0, 

13.4; Whitfieldella cf. W. nu- cleolata, 22.0; Euomphalus? 

sp., 15.9, 13.4; Dalmanella 

clarki, Uncinulus convexorus?, Wilsonia globosa, 13.4; Spirijer 

modestus, Spirifer vanuxemi?, 

Rhynchospira globosa . var., 

Proetus pachydermatus, Proetus protuberans, 12.3 ......... . Shale, irregular .............. . .. . 

Total 

Thick- thick- ness. ness. 

Feet. 

8.0 

10. 0 

6.0 

. 6 

23.6 

.3 

Feet. 

60.1 

52. 1 

42. 1 

36. 1 

. 35.5 

11.9 

Section at Grovania-Continued. 

Helderberg limestone-Continued. 

Keyser limestone member-Contd. 

Limestone, irregu~arly bedded, 

somewhat nodular, dark gray; courses often separated by 

shale laminae. Favos7:tes sp., 

11.1; Schuchertella sp., 11.1, 

7.6; Camarotoechiasp. ?, Atrypa 

reticularis, Proetus protuberans, 11.1; Leperditia sp., 

11.1-1.6; Camarotoechia? laTotal 

Thick- th~ck­ ness. ness. 

mellata, Rhynchospira globosa Feet. Feet. 

var.,9.6;0stracoda,8.6 ....... 11.6 . 11. 6 

122.5 

Tonoloway limestone: 

Limestone, dark gray, pure; con- choidal fracture; many transverse 

calcite seams; when unweathered 

is a massive unit though l-inch 

bedding is shown in the upper part 

and 6-inch bedding near the base; 

it is not nodular or platy; shows a persistent thin shaly layer at 

-8.0. Ostracoda, -2.L.......... i2. 0 -12. 0 

Limestone, fissile, platy, dark gray; 

joints have yellow discolored borders. Leperditia sp. (a), -17.0..... 10. 0 -22. 0 

Limestone, fissile, · .P~aty, much 

weathered. Leperdttw sp., -26.0.. 6. 0 -28. 0 

Limestone, solid, dark gray, banded 

in parts........ . . . . . . . . . . . . . . . . . . . 6. 6 -34. 6 

Limestone, :fissile, platy, much 

weathered, yellow; fresh surface is 

dark gray. Leperditia sp., -35.9, 

-37.9 ............................ 4.3 -38.9 

Concealed. 

38. 9 

The Grovania section resembles the Tyrone 

sections very closely, but differs from all the 

others studied in Pennsylvania and from the 

Maryland sections. The Tonoloway is identical 

.1n lithology with that in the other sections, 

though its fauna, so far as it is known, includes 

only ostracodes. The Chonetes jerseyensis zone 

of the Keyser is well developed and carries a 

· characteristic fauna. The Favosites helderbergiae var. praecedens zone of the Keyser is peculiar in that its lower part 1s made up of 

thick_ beds of coralline limestone and stromatoporoids. ·It has f:tlso a thin zone of Rensselaeria mutabilis, but it lacks most of the other 

characteristic brachiopods of the upper Keyser 

and contains no Tentaculites gyracanthus. The 

Coeymans is here. a sandstone, ·as it is in the 

easternmost Maryland sections: 

0 
DEPARTMENT OF THE INTERIOR 

FRANKLIN K. LANE, Secretary 

UNITED STATES GEOLOGICAL SURVEY 

GEORGE OTIS SMITH, Director 

Professional Paper 108-L 

STRATIGRAPHY OF THE. HANNA BASIN, WYOMING 

BY 

C. F. BOWEN 

Published May 7,1918 

Shorter contributions to general geology, 1917 , I 

<.t;ages 227-235) 

WASHINGTON 

GOVERNMENT PRINTING OVFICE 

191 8 
CONTENTS. 

Introduction .............. __ ... _ ........ . ..... _. : . .......... ......... -... ---.-----.----- -------.---.-----

stra~~~:!i ~~~t-i~~- _- _- ~ ~ --~ _- _- _____ ~: : : : : : : : : : : ~ ~ : : : : : : : : : : : : : : : : : : : : : :·: : : : : : : : : : : : : : : : : : : : : : : : : : : : : :_: : : : : ~ ~ ~ ~ 

~=r~~~i~~::: ~o~~a~~~~: : : : : : : : : : : : : : : : : : : : : : : : : : : :·: : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : :_: : :: 

Hanna formation._ .. _______ _____ _____ ___ . __ . ______________ . ___ . _______ .. _ ........ _. ___ .. ... _ . . _. __ .. . 

North Park formation .. c • .•.. . . ..••••.••••••••...... ..•..•• • •••••• - ••••••••• ------------ - ------------

Structure ..... : ..... _ .......................... · ......... : ............ -.------.------------- ~- ------ ----- Folding and faulting ____________ ... ___ .. .. _ . _ ... __ ... _ . ____ .. _ . ___ _____ ... ___ . _ ... __ . _______ . ~ _____ . 

Unconformities._ ... _ _" _. __ . __ .. _ .... _._ ... _ .. _________ .......... _. ____ ._. __ __ -.- __ . . ...... _ .. ______ .. 

Source of the materiaL ___ ~ __ .. ______ ...... _ ........... ___ .. _. __ . _ ... _. ___ .. __ . ___ . _ .. ____ ..... _-___ . ___ . . . 

Conclusion ....... . ... _ .. _ . ___ . ____ . _ .. ~ .. . ....... ___ __ ____ . ~ ____ ... __ ..... _ . _______ · ___ . _ . _ . _ ... _ . _____ .. . 

ILLUSTRATIONS. 

• PLATE LXVI. Chart showing thickness, character, and probable correlation of formations between Medicine 

Bow, Wyo., and Coalville, Utah .......... ______ ._._ ... _ ......... _ ................... __ ... . 

FIGURE 31. Key map showing location of Hanna Basin, Wyo .... _.: ............................. ..... .... . 

II 

·. 

Page. 

227 

228 

228 

229 

230 

231 

231 

231 

231 

231 

~34 

235 

Page. 

234 

227 
STRATIGRAPHY OF THE HANNA BASIN, WYOMING. 

By C. F. BowEN. 

INTRODUCTION. As the result of his work in the Hanna Basin 

Carbon CDounty, Vvyo., has attracted the ·(see fig. 31) in 1906, Veatch 1 subdivided this 

attention o geologists since the days of the group of rocks into two formations, which he 

territorial surveys under King, Hayden, designated "Lower- Laramie" and "Upper 

and Powell. During this earlier work all the Laramie," and made the statement that the 

50 o so 100 1501\files -~~~~======~~~~~====== 

FIGURE 31.-Kcy map showing location of Hanna Basin, Wyo. 

rocks (except the North Park formation) over..: 

lying the uppermost beds of marine origin 

were grouped in a single formation, for which 

the name Laramie was proposed. 

two were separated by an unconformity that 

involved the removal of 20,000 feet· of rocks. 

1 Veatch, A. C.,Coalin east-centralCarbonCounty, Wyo.: U.S. Geol. 

Survey Bull. 316, p. 246, 1906; The origin and definition of the term 

Laramie: Jour. Geology, vol. 15, pp. 526-549, 1907. · 

227 
228 . SHORTER CQNT'RIBUTIONS TO GENERAL GEOLOGY, 191i. 

Veatch's upper formation became the type of 

the "Upper Laramie formation," and the flora 

which it yielded was adopted as a standard for 

purposes of comparison in other fields. 

It is the purpose of the present paper (1) to 

show that the "Upper Laramie" as defined by 

Veatch consists of two formations separated by 

a marked unconformity; (2) to show that this 

unconformity is the one which he regarded as 

representing the · erosion of 20,000 feet and referred to the base of the "Upper Laramie formation"; (3) to present the facts so far as they 

can--now be interpreted for and against the existence of an unconformity at ·the . horizon 

~ndica ted by Veatch; and ( 4) to offer some suggestions as to the source of the material which 

goes to make up the enormous thickness of 

continental deposits of this era. 

STRATIGRAPHY. 

GENERAL SECTION. 

The formations exposed in or immediately 

adjacent to the area under consideration range 

in age from Cambrian (~)to probably Miocene. 

Those in the upper part of the section-that is 

above the base of Veatch's "Lower Laramie"-

are of chief interest and will be described somewhat in detail; the underlying formati-ons will 

be referred to but briefly. The sequence and 

gf:meral character of the Mesoz()ic and Cenozoic 

formations are shown in the following table: 

Mesozoic and Cenozoic jm:rnations in Hanna Basin, Wyo . 

. System. Formation. Thickness Characteristics. _(feet) . 

. Alluvium. Worked-over material from surrounding formations. 

Quaternary. 

Terrace gravel. 0-25± Waterworn pebbles of older sedimentary and crystalline rocks. 

North Park formation. 0-400± Whitish unconsolidated sand and clay with thin intercalated 

beds of limestone in some places; conglomeratic at base. 

........................... Unconformity ........... 

Alternating beds of dark-gray, yellowish, and carbonaceous 

shale; white, gray, and brown sandstones, massive to thin 

bedded and commonly cross-bedded; conglomerates and 

Tertiary. Hanna formation. conglomeratic sandstones containing pebbles of chert,-

7, 000± granite, quartzite, sandstone, Mowry shale, CloverlY.' con- glomerate, etc. (these conglomerates are distnbuted 

throughout the section but ~e most abundant in the lower 

half), and numerous beds of coal. Contains fossil bones of 

vertebrates, fresh-water shells, and an abundance of leaves. 

.......................... .. .. Unconformity .. ·_ ......... 

Light-colored, dark-gray, and carbona<;eous shale; buff to 

brown sandstone; in places extremely cross-bedded and 

showing great irregularity of deposition and numerous beds 

Tertiary (?). Ferris formation. I 6, 500± of coal. Pockets, ·lenses, and thin beds of conglomerate 

composed of pebbles of older rocks are distributed through a zone about 1,000 feet thick at the base of the formation. - Contains fresh-water invertebrates, land plants, and bones 

of vertebrates. -

Light-colored to gray carbonaceous shale; gray to brown 

sandstone showing cross-bedding, ripple marks, and -other 

Medicine Bow formation. 6, 200± features of irregular deposition; and thin irregular beds of 

coal. Fresh and br.ackish water, invertebrates, land plants, 

and bones of vertebrates. 

Cretaceous. 

Predominantly dark-gray shale with thin intercalated beds of 

shaly sandstone and some beds of light-colored massive to 

Lewis shale. 3, 300± heavy-bedded sandstone. N-ear the top of the formation 

is a persistent ledge-making gray sandstone about 270 feet 

thick. Marine. · 
STRATIGRAPHY OF THE HANNA BASIN, WYO. 229 

Mesozoic and Cenozoicjormations in Hanna Basin, Wyo.-Contlnued. 

System. Formation. Thickness Characteristics. (feet). 

An upper member of whitish sandstone alternating with gray 

and carbonaceous shale with a conspicuous resistant white 

sandstone at the top; contains thin irregular beds of coal in 

Mesaverde formation. some places. A midd~e member of brown to gray sandstone, 

2, 700 gray carbonaceous shale, and thin irregular beds-of coal; 

differs from upper member in its prevailingly brown color; 

fresh and brackish water fauna. A lower member of gray 

to white sandstone and gray shale; contains a marine fauna 

and is not coal bearing. 

Steele shale. 4, 000± 

Dark-gray shale with intercalated beds of sandstone and 

shaly sandstone, some of which form conspicuous ledges near top of formation. Shale contains concretions of cal- careous sandstone, dark limestone, and white crystalline 

calcite. Marine fauna. 

Niobrara formation. 370± Calcareous shale with considerable intercalated white crystalline calcite at top and bottom. -

Cretaceous. 

Carlile shale. 200 Dark-gray to black shale with some thin sandy layers. 

An upper member composed of thick beds of sandstone alterFrontier formation. 700 nating with thinner beds of shale and a lower member 

. composed of dark-gray shale . 

Mowry shale. 170 Fissile shale, dark brown on fresh surface but weathering to 

silver gray or white. _ . . 

Thermopolis shale. 140 Dark-gray shale with thin sandy layers. 

Cloverly formation. 231 An upper me~ber of sandstone, a midd-le member of shale, 

and a lower member of conglomeratic sandstone. 

-----------------------------· 

Cretaceous (?). Morrison formation. 350 Shale, mostly gray or greenish, alternating with sandy shale 

and sandstone. Contains .bones of. dinosaurs. 

\ 

-----------------------------

Jurassic. Sundance formation. 85 Chiefly green, olive, and drab shales with a few thin intercalated beds of sandstone~ 

I 

Triassic. Chugwater f~rmation. 1, 000- Chiefly red shale with· intercalated red, buff, and yellow 

sandstone. 

For stratigraphic study the most important 

of the formations given in the table are the 

Mowry shale, the Frontier, anu the Mesaverde, 

because they possess characteristics which render them valuable as horizon markers. This is 

especially true of the silver-gray fish-scale shale 

of the Mowry. 

·MEDICINE BOW FORMATION. 

Above the highest marine formation-the 

Lewis shale-is a mass of continental deposits, . divisible into four formations having a 

maximum thickness of more than 20,000 feet. 

For the lowest of these formations the name 
230 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

Medicine Bow is here proposed, because the formation is best exposed and most easily studied 

along both sides -of North Platte River at the 

mouth of the Medicine Bow. The Medicine 

found that are sufficiently diagnostic for even 

generic determination. 

FERRIS FORMATION. 

Bow formation. is the equivalent of the "Lower The Medicine Bow formation is terminated 

Laramie" as defined by Veatch. The latter above by a conglomeratic zone taken as the 

term is not applicable, for the _" Upper Lara- base of the Ferris formation, so named because 

mie," in the sense in which that term was it is best exposed from the old Ferris ranch, on 

originally used, · is not of Laramie age. As the North Platte River, ea~tward to the top of the 

relation of the Medicine Bow formation to the hill north of "Middle Ditch" at its junction 

Laramie ·of the Denver Basin can not be deter- with "Big Ditch." As defined the Ferris formined by field re~ations, and as paleontologists mation is approximately equivalent. to the 

are not agreed as to the relation of the fossil lower half of the "Upper _Lara:p1ie" of Veatch. 

remains found in the two formations, the use -The conglomerate at the b.a,se _of the: Ferris forof the unqualified term "Laramie" is not ad visa- mation ranges through an iiJterval of aheut 

ble, and it is thought that confusion may be 1,000 f~et, in which massive sandstone, more 

avoided by the use of an entirely new name or less conglomeratic, . alternates with nonfor the formation hitherto called ''Lower conglomeratic sandstone and shale. · The conLaramie." glomerate is sparingly developed at the · base 

The Medicine Bow formation rests-conform- of the zone but increases in amoun_t upward. 

ably on the Lewis and consists of an alternating It is succeeded by an alternating series of sandsuccession of shale and massive to thin-bedded, stone and shale containing .numerous beds of -

ripple-marked, and cross~bedded sandstones, eoal. The maximum thickness of the formawith several beds of coal in the lower third of tion is about 6,500 feet. 

the formation. The massive and thick-bedded Both the matrix and the pebbles of the consandstones are .commonly somewhat coarser glomerate consist of materials of the same kind 

-than the thin-bedded varieties and in some as make up the sandstone of the underlying 

places contain clay balls and an occasional Medicine Bow formation. The · pebbles conpebble the size of a pea. sist mainly of chert and white quartz or 

Microscopic examination -shows that the quartzite; then follow in about the order 

sandstone is composed of fragments of quartz, named red and gray quartzite, porphyries, ~nd 

quartzite, feldspar, chert, schist, volcanic rocks, conglomerate, with subordinate amounts of 

limestone, and other minor constituents. In other constituents. Three facts impress the 

other words, it has been derived from both student of this conglqmerate: (1) It · is m~de 

sedimentary and igneous rocks. The grains up of only the most resistant kinds of rock; (2) 

show considerable variation in the degree of it is lacking in several kinds of ;rock now exsorting and rounding, but on the whole are posed in the surrounding mountains-for 

decidedly angular. One section ~howed well- example, granite, Iimestone,sandstone,C~overly · 

rounded grains, 20 per cent; subangular grains, conglomerate, and Mo~y shalej (3) It co~-

35 per cent; angular grains, 45 per cent. These tains materials that seem to be foreign to this 

proportions suggest that the grains are chiefly region, namely, quartzite, porphyry (quartz 

the result of mechanical disintegration and latite), and rhyolite. These features lead to 

rapid transportation with little or no subse- the inference that the conglomerate and also 

quent reworking. ._ · the associated s.andstone- were derived from 

The formation contains remains of fresh and some distant source rather than from the 

brackish water invertebrates, land plants, and · f h 

d near-by- mountains. This In erence .· . as a. n bones of vertebrates. The plants are regarde f d - h important bearing on the unco_n ormities -Is- by F. H. Knowlton as of the same age as t_ e · f h D B · cussed on pages 231-234. 

plants of the Laramie o t e enver asin. The Ferris formation contains fresh-water The invertebrates are considered by T. W. 

Stanton to belong to the .fauna of the Lance invertebrat~s, land plants, and bones of verteformation. The bones J>elong in part to the brates. -- The shells and plants, which· are 

ceratopsians, but no specimens have been found chiefly above the conglomerate z.one, are 
STRATIGRAPHY OF THE HANNA BASIN, WYO. 231 

regarded as of Fort Union age, whereas the 

vertebrate remains, thus far found only in the 

conglomeratic zone, consist of bones of turtle8, 

indeterminable fragments of ceratopsians, and 

a few specimens that have been identified by 

_C. W. Gilmore as Triceratops. The bones of 

Triceratops tend to show that the basal part of 

the formation should be correlated with the 

Lance of Wyoming and Montana and the 

Denver foTmation of the Denver Basin. There 

is, however, no conclusive proof of an unconformity below the bone horizon in the Hanna 

Basin, as there is said to be in the Denver 

Basin. 

HANNA FORMATION. 

For the upper part of the "Upper Laramie" 

as defined by Veatch the name Hanna formation is proposed, because the formation is well 

exposed to the west and north of the townof 

Hanna and yields all the coal mined at that 

place. The Hanna formation rests unconformably on the Ferris formation. A conglomeratic sandstone marks its base, above which 

conglomerate, sandstone, shale, and coal beds 

alternate to the top of the formation, some 

7,000 feet above the ba;se. 

This formation differs from the Ferris . in 

being highly feldspathic, in being conglomeratic 

throughout, and in the fact that the conglomerate contains an abundance of local 

material, notably granite, Mowry shale, and 

Cloverly conglomerate. The relative abundance of these constituents varies from place to 

place in accordance with ·the character of the 

surrounding rocks. Thus near outcrops of the 

Mowry shale and the underlying Cloverly 

those rocks constitute most of the pebbles, 

near outcrops of granite that rock is the most 

abundant material in the conglomerate, and in 

the center-of the basin granite, sandstone, and 

conglomerate pebbles are associated with 

chert, white quartz, quartzite, etc. 

This formation contains an abundance of 

plant remains, all of which are referred to the 

Fort Union by Mr. Knowlton. The invertebrates are also regarded by Mr. Stanton as 

chiefly indicative of Fort Union age, though 

species found near the top are said to resemble 

the Wasatch fauna. Only a few fragmentary 

remains of vertebrates have thus far been 

found in this formation. They include fish 

scales, fragments of turtle shells, and a fragmentary mammalian jaw identified by J. W. 

Gidley as a creodont, -probably Claenodon, 

which may belong to either the Fort Union or 

Wasatch. 

NORTH PARK FORMATION. 

The North Park formation rests unconformably on the underlying rocks. This form·ation 

consists of conglomerate, unconsolidated sand 

and marl, and local thin beds of limestone. 

A peculiarity of the formation is that in many 

places its surface is thickly strewn with 

boulders of white, vitreous quartzite as much 

as 2 ·feet in diameter, -but none of these haveever been . found actually embedded in -the 

formation~ -· 

No fossils have been found in the North 

Park, and its age is therefore largely a matter 

of conjecture, but it is thought to be Miocene. 

STRUCTURE. 

FOLDING AND FAULTING. 

Folding is the dominant structural feature 

of the Hanna Basin, though faulting has 

occurred - to some extent. A characteristic 

of the folds is that they are all oversteepened 

toward the west or southwest. 

All the rocks up to and _including the Ferris 

formation seem to have been equally deformed 

and were folded, faulted, and deeply eroded 

before the deposition of the Hanna formation. 

After the deposition of this formation there 

was another disturbance, which followed chiefly 

the lines of the earlier movements and served to 

emphasize the features of structure already 

produced. By this disturbance the Hanna 

formation was tilted in some places into _a 

vertical position and was locally faulted. A 

third disturbance seems to have taken place 

subsequent to the deposition of the North 

Park formation, for this formation is now 

tilted in some places 40° or more. 

UNCONFORMITIES. 

Perhaps the most interesting structural 

problem in the field relates to the occurrence 

and magnitude of the unconformities. There 

_are certainly two and possibly three unconformities present. The highest of these _is at 

the base of the North Park formation, which 

overlaps all -other formations in the field. 
232 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

TIH~ next lower un·conformity is that at the 

base of the Hanna formation, formerly assigned 

to the base of the Ferris formation. It repre-

. sents the removal of more rather than less 

than the 20,000 feet assigned by Veatch. 

The existence of this unconformity is demonstrated by the following field relations: (1) 

There is a :inarked angular discordance between the underlying and overlying formations; 

(2) the Hanna formation transgresses all the 

underlying formationS at least down to the 

Cloverly and possibly down to· the granite; 

(3) the Hanna formation has been less intensely 

deformed than the . underlying formations; 

(4) the conglomerate _at the base of .the Hanna 

formation has clearly · been derived from all 

the underlying rocks and is chiefly of local 

origin. 

That this unconformity is the one assigned by 

Veatch to the base of his "Upper Laramie" is 

evident froni the following considerations: 

(1) It is the most conspicuous break in the field; 

(2) it is the only unconformity present at some 

of the typical places observed by Veatch, the 

lower beds being there cut by overlap; (3) the 

Ferris formation nowhere transgresses the 

"Lower Laramie" and overlaps older rocks, 

as was postulated by Veatch; (4) all the rocks 

between the Medicine Bow ("Lower Laramie") 

and North Park were included by Veatch in a 

single formation. 

Veatch's mistake was a natural one to make 

in rapid reconnaissance work. In the east~ 

ern part of the basin, where the unconformity 

is most evident,· the conglomerate of the Ferris 

formation is either cut out by overlap or is 

directly overlain by the conglomerate of the 

Harina formation, all the intervening strata 

being eroded. These relations were not 

detected in a rapid examination, but are perfectly clear when studied and mapped in detail. 

On the west side of the ·basin the two con:.. 

glomerates are separated by a stratigraphic 

inter·val of nearly 6,000 feet and by a horizontal· distance of 5 to 7 miles. In that area 

Veatch appears to have recognized only the 

lower of the two conglomerates and to have 

unhesitatingly correlated it with the unconformity he saw farther east. 

Th.e next question that arises is regarding 

the significance of -the conglomerate at the base 

of the Ferris formation. It has been held that, 

because this conglomerate is made up in part 

of pebbles containing Paleozoic fossils, it necessarily represents a period of uplift and erosion 

between the deposition of the Medicine Bow 

and that of the Ferris formation ("Upper 

Laramie" and .. "Lower Laramie") sufficient 

to expose the Paleozoic , rocks. This would 

naturally f~llow if it could be proved that Paleozoic rocks did not contribute materials to the 

underlying formation or th1;1t the pebbles of 

the conglomerate came from a different source 

than the sand- and clay of the underlying 

formation. As previously stated, microsco.pic 

study shows that the constituents of this conglomerate are all represented in the sandstone 

of 'the Medicine Bow formation. This seems 

to indicate that both were derived from· the 

same source and · that Paleozoic rocks contributed material to the Medicine Bow formation, as well as to the conglomerate above it. 

It is therefore not necessary to assume a great 

interval of uplift and ~r~sion between the 

periods of deposition of the two formations to 

account for the Paleozoic pebbles· in this conglomerate any more than it is necessary to 

assume a great interval of uplift and erosion 

to account for each of the successive conglomerates in the Hanna formation, or the conglomerates of · earlier formations, such as the 

Beckwith in Uinta County and the Frontier ( ~) 

at Coalville, Utah. The presence of P.aleozoic 

pebbles in these conglomerates, as well as in 

the Cloverly, is proof that the Paleozoic formations had been exposed somewhere in the 

region atleast since.the beginning of the Cretaceous period. That is, in so far as the evidence furnished by the conglomerate alone· is 

concerned, it seems to the writer that there is 

no more ·argument for assuming an · unconformity ·between the Ferris and Medicine Bow 

formations than there is for assuming an unconformity at the ~ase of each of the conglom- · 

erates in the Beckwith, Frontier, and Hanna 

formati~ns. Each of these conglomerates contains pebbles of Paleozoic rocks. 

It is recognized, however, that _a conglomerate indicates a more or less pronounced 

change in conditions of sedimentation. This 

change could be accomplished by a rejuvenation of the streams of an already existing land 

mass, by climatic changes, or by a combination of these and possibly other causes. The 

point made here is that the existence of a conglomerate is not positive proof of a great un-
STRATIGRAPHY OF THE HANNA BASIN, WYO. 233 

conformity. This is especially true of a conglomerate occurring in the midst of a great 

mass of continental deposits that have · the 

same lithologic character throughout-conditions entirely different from those presented 

by a conglomerate that separates two marine 

deposits or one deposit of marine origin and 

another of continental origin. 

The field relations of the Ferris conglomerate 

and the underlying formation show (1) that the 

two have ·been equally deformed; (2) that 

there is no angular discordance between them 

either in the Hanna Basin or in other areas 

where both are present; (3) that the Ferris 

formation is nowhere known to transgress the 

Medicine Bow formation and overlap older 

rocks; ( 4) that, as previously indicated, the 

conglomerate seems to have been derived from 

the same source as the Medicine Bow; (5) that 

there appears to be a gradual transition from 

the Medicine Bow formation to the Ferris formation. The contact between the two is not 

sharply defined, coarse sandstone of the Medicine Bow being followed by grits in which a 

few small pebbles occur, and these giving place 

higher up to pockets, lenses, and thin beds of 

conglomerate, which are fina.lly succeeded by 

thick beds of sandstone that are conglomeratic 

throughout. Interbedded in this transition 

zone are several beds of dark-gray shale, some 

.of which attain a thickness of 30 feet. 

This transition zone is very significant, occurring in all areas where both the Medicine 

Bow and Ferris formations or their equivalents 

are present. In the sou.thern pa~t of -the 

Great Divide Basin it is; according to Smith, 1 

800 feet thick and consists chiefly of clay with 

interbedded thin rusty-brown sandstone, which 

becomes increasingly conglomeratic toward the 

top. In the northern part of the Great Divide 

Basin, according tQ the same author, the transition zone is still thicker. 

Similar conditions in the Little Snake River 

- field are described by Ball and Stebinger. 2 

This thick . transition zone between the assumed unconformity and the principal conglomeratic zone supposed to represent it seems 

to the writer to be a fatal objection to the idea 

of an unconformity. It is difficult to conceive 

1 Smith, E. E., The eastern part of the Great Divide Basin coal field, 

Wyo.: U.S. Geol. Survey Bull. 341, p. 224, 1907. 

2 Ball, M. W., and Stcbinger, Eugene, The eastern part of thE' Little 

Snake River roal field, Wyo.: U. S. Geol. Survey. Bull. 381, p. 190, 1910. 

19437°-18--2 

of a basal conglomerate occurring several hun~ 

dred feet above the base it is assumed to repre-:-

sent. These conditions lead to the inference 

that no unconformity exists between the two 

formations. 

The arguments in favor of an unconformity 

are (1) the conglomerate at the base of the, 

Ferris formation, which, if the above reasoning · 

is sound, has no weight; (2) a considerable 

thinning of the Medicine Bow formation in 

some places, which is pattly offset by the fact 

that the Lewis and Mesaverde show just as 

great variations in thickness within as short 

distances; and (3) the fact that at the base of 

the Evanston formation of Uinta County, correlated with the Hanna at Carbon, there is an 

unconformity which ·has been assumed to represent the interval between the Medicine Bow 

("Lower Laram~e ") and Ferris ("Upper Laramie'') epochs. 

The question now arises whether the Evansron formation should be correlated with the 

Ferris or with the Hanna .formation. There · 

are three lines of evidence which suggest that 

it should be correlated with the Hanna. (1) 

The flora of the Evanston is said to correspond 

to that obtained from the old town of Carbon, 

which in all probability came chiefly if ~ot 

entirely from the Hanna formation and there:-

fore tends to support the correlation of the 

Evanston with that formation; (2) the Evans"'" 

ton is conformable with the overlying Wasatch, 

a relation which is not known to exist between 

the Wasatch and older rocks in any other place 

in southern Wyoming; (3) the relation of the 

Evanston to the Adaville ("Lower Laramie") 

is largely a matter of inference, for it nowhere 

rests on the Adaville, and sonie of those most 

familiar with the Evanston section now believe 

that the Adaville formation, formerly thought 

to represent the "Lower Laramie," is really 

Mesaverde. 

It seems to the writer, therefore, that the 

weight of evidence so far as it can now be interpreted is opposed to the existence of a great 

unconformity at the base of the Ferris formation, but it is freely admitted that more detailed field work over wider areas is necessary 

to decide this question. It is of course possible that a considerable unconformity near 

the margin of the ancient land mass from which 

the sediments were der.ived may give place to 
234 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1917. 

· apparent conformable relatiori.s at a considerable distance from that place. But it is ,still 

a fact that unconformity between the Fort 

Union and Wasatch is the most widespread and 

significant break that had been produced up to 

that time since the beginning of the Cretaceous 

period. · 

SOURCE OF THE MATERIAL. 

The source of the enormous amount of sediment represented in these continental deposits 

is an interesting problem. 

For the Hanna formation it can be stated 

with considerable confidence that the material 

was derived from all the underlying formations 

and is of more or less_ local origin. 

For the underlying formations the case· is not 

so simple. Even if it. coUld be demonstrated 

that the Ferris for!Jlation is of local-derivationJ 

it would still be necesSary to explain the SOUrCe 

of the 6,200 feet of the Medicine Bow formation 

to which the immediately underlying rocks did 

not contribute. A study of at least all the 

Cretaceous formations is therefore necessary 

to throw light on the problem. 

A few suggestions may be offered by comparing the sections in the accompanying 

chart (Pl. LXVI). These sections extend from 

_the east side of the Hann~ Basin westward 

through Rawlins, Rock Springs, and Evanston 

to Coalville, Utah. In constructing them the 

Mowry shale was taken as a datum plane. 

To consider first the sandstone fo'rmations ' these sections show that from east to west the 

Mesaverde and Frontier thicken regularly, the 

materials become coarser with pronounced 

development of conglomerate in the Frontier 

and with slight indications of conglOmerate 

in the upper part of the Mesaverde, and there 

is a marked development of coal in both 

formations. ' 

The 700-foot interval represented by the 

Morrison and Cloverly· near Medicine Bow . is 

represented by the several-thousand feet of 

Bear River and the, upper part of the Beckwith 

· in Uinta County. Although individual units 

{)f this group can not be exactly correlated, 

their upper and lower limits are definitely 

fixed, the upper by the Mowry shale and the 

lower by the Jurassic (Sundance and Twin 

Creek) formations, which are correlated with 

each ·other by their marine faunas. 

The Beckwith includes many beds of coarse 

sands~one· and conglomerate containing pebbles 

of Paleozoic rocks, and the Bear River is coal 

bearing. There is no coal ·in this interval in 

the Medicine Bow . area, and the conglomerate 

of the Cloverly is composed almost entirely of 

small -pebbles of black chert rarely exceeding 

half an inch in diameter. These pebbles 

show by their fineness and thorough. assortment that they have been transported for 

long distances. 

Of the shale fo~mations the Lewis thins 

from east to west-that is, i~ th~ direction in 

which the sandstones thicken. The Mowry 

and the Hilliard and Steele shales, however, do 

not. The westward thickening_ of the Mowry 

is doubtless due to the fact that it is coarser 

and contains .a considerable amount of interbedded sandstone in . its western 'part. The 

Hilliard also carries large lenses of sandstone 

in Uinta County, hut its apparent t.Q.ickening 

toward the west .may be due to the difficulty 

of accurately determining its thickness because 

of lack of exposures, inability to m~~sure dips 

except in the overlying and underlying formations, and the possibility that its boundaries 

have not been .. drawn at the same horizon in 

the several fields. 

·The evidence of these sections seems to 

indicate that all the Cretaceous formations up 

to the top of the .Lewis . were derived from a 

western source. 

As the Medicine Bow formation, or its 

equivalent the "Lower Laramie," rests conformably . on the Lewis and shows some tendency to become coarser westward, as indica.ted by !ts slightly Qonglomeratic character 

in places in the Rock Springs field, the inf-erence is that it was derived from the same source 

as the underlying formations. 

The fact that the Ferris Jormation seems to · 

be more closely related to the Medicine Bow 

both lithologically and structurally than to 

the overlying . formation, together with the 

evidence that the conglomerate cam·e from 

some distant source, would seem j;o indicate 

that this formation also came from the west. 

This view is somewhat strengthened by the 

fact that pebbles of quartzite occurring in the 

conglo~erate are similar to the quartzite in 

the Uinta Mountains. · 
PROFESSIONAL PAPER 108 PLATE LXVI 

U. S. GEOLOGICAL SURVEY 

Section at 

Coalville. Utah 

·p Ot' --

fO~,.V. --

/'.~C.;; - - - vJ"J - - ---- - -----

Conglom_erate 

.... ' ' .... Conglomerat e ', 

Coal r:~,, 

' ' 

Section in southwestern Uinta County 

\ Evanston) 

WASA1CH FORMATION 

-- -- -- - -

FORMATION 

- - -----

Probable gr_r~l!!t..! q_n - - -- --- ---·---

------~------ -­

-------------

I 

I 

I 

I 

I 

I 

Section in 

Rock Springs field 

(Schultz,t909) 

I 

I 

---

FORMATION 

___ _ .,.,. ---

LA RAM IE(?) FORMATION 

------ _-_:--=---=~ ~:: :::.::-~ ~:: ==· = == = ===--=-·-:_ _-:_~--_-_-. -: _- ------------------------------- LEWIS SHAI.E - -- - -------- ------- - -- -- --·-

ADAVILi E FORMATION 

M ESAVERDE fORMATIO"' 

------------

--- - --

H ILLIARD FORMATION 

.... 

FRON TIER FORMATION ' '-, 

' ' ' ' ----- - - --------- -------- ---- ---------------------- ---- ----- ---

·- ----87 mi les-----

- ---.... ----.,.,.,..--,.. 

--------- ------------- ----------------------------

--.. __ _ 

--------

------ ----- -------------------

Section at 

Section on westside of Hanna 

Basin 

Coal bearing HAN NA fORMATION 

sout h end of Great Divide 

Basin 

(Smith.l909) 

--- 35 m i les I 

--30 miles ----

-------------------------

UNDiffERENTIATED 

TERTIARY 

--------

LARAMIE FORMATION 

---- ---- ---

MESAVER DE FOR MATION 

Coal bearing 

----- -- ---

--- -----------------------

FORMATION= NIOBRARA SHALE 

AND BASAL SHALE PORTION 

OF M ONTANA 

FERRIS fORMATION 

------...... _ 

----------- MEDICINE BOW FOR MATION 

LEWIS SHALE 

MESAVERDE FORMAfiON 

STEELE SHALE 

Coal beds ------------- Conglomeratic sandstone 

--------------- - ----------- ---------- - - ---------------- - --·------- -------- ---------- ----- -·------ ------------- rRONT d:.R FORMATION ---------- ------------------ --------- - - ----- ------- - -------

Section on east s ide of Hanna 

Basin 

HANNA fORMATIO N 

f ERRIS FORMATION 

MEDICIN E B OW FORMATION 

MESAVERDE fORMATION 

Coal beds ~ ------ ---------·--- - -------- ------ - - ---------------------- --- ---- - -----·- ----=-------===....::-.::::.:::- - ---

-:~~~?t:::::: :: .!'-~~~5~~!== = = = -::.::-::-_-_-:::: ... --=----=---::.::.:::== = ===---- - ---- ------- -------------------- ---- ------- -------------- ---- - -------------------- ----------- -----

--- ------

' ' ' ' ' ' ' ' ' ' ' ' ' ' 

--:-_::-:-

-------·- --------------------- ----- --- - ------- ·- ----- ------- -----------------------· 

--- -~-- ------ -·- --- ----------------------

-----------------------------------

------ --- ------

TWIN CREEK LIMESTONf. 

---- -- ------

NU GG T SANOSTOIH 

---

---

------

-- ... - --

------

---- --

--- --- --

---- ----- --

---

-----

__ ... 

---

---

--- ---

----

-- -- --- ---- --- --- ---- -- -- ---- --

------ --- --- --- --- --- -- --- -- -- ---- --- --- -- ---- ------ -- ---- --- -- --- ---- --- --

Vertical scale 

s,oLo o~ __ _L __ L_~ ___ oL_ ______________ s~,oL o ______________ ~o~,oo~o~----------- 5~,ooo Feet 

CHART SHOWING THICKNESS, CHARACTER, AND PROBABLE CORRELATION OF FORMATIONS BETWEEN MEDICINE BOW, WYO., AND COALVILLE, UTAH 
STRATIGRAPHY OF THE HANNA BASIN, WYO. 235 

CONCLUSION. field relations do not suggest an unconformity 

By way of summary it may be said that the at the base of the Ferris formation; that 

great break, as indicated by structural a:n,d PaJeozoic rocks contributed to the sedimentary 

field relations, occurs at the base of the Hanna formations from at least the beginning of 

formation; that this formation is the equivalent Cretaceous time; a d that the sediments 

of the Wasatch of the Great Divide Basin and seem to have· been erived from the west or 

Rock Springs fields; that the structural and southwest. 
I'NDEX. 

A. Page. 

Acknowledgments for aid ................... 1, 49, 61, 80, 125, 1G5, 179, IsS 

·Alamo Canyon, N.Mex., entrance to, plate showing............. 37 

Alamogordo, N.Mex., view southeastward from, plate showing.. 50 

Algonkian (?) complex, distribution and character of, in southwestern Maine and southeastern New Hampshire .. 167-168 

igne.ous rocks of ..... .. . . ................................. . . 175-176 

Alluvium from Mississippi, analyses of....................... . ... 135 

Anemia fremonti Knowlton, n. sp., description of. . . . . . . . . . . . . . . . 84--85 

plates showing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99, 100 

Appalachian province, remains of peneplains in ............... 151-154 

Aralia veatchii Knowlton, n. sp., description of .................. 92-93 

plates showing .............................. , . . . . . . 104, 105, 106, 107 

Asplenium occidentale Knowlton, n. sp., description of............ 84 

plate showing..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • . . . . . . . . . . . . 99 

B. 

Badlands near Sussex, Wyo., plate showing...................... 59 

Baker, R. F., acknowledgment to................................ 179 

Bastin, E. S., cited... ... .... .... ..... ...... ...... ... .... .. ....... 8 

Bauneg Beg Pond, North Berwick and Sanfqrd, Maine., moraine 

on ............... . ................... . ........ ..... . .. 24-25 

Becraft limestone, absence of, in central Pennsylvania........... 193 

Bennett, H. R., acknowledgment to .................. ...... : ..... 179 

Berry, Edward Wilber, cited..................................... 130 

Geologic history indicated by the fossiliferous deposits of the 

Wilcox group (Eocene) at Meridian, Miss ....... . ..... 61-72 

Berwick gneiss, distribution and ch!'tracter of, in southwestern 

Maine and southeastern New Hampshire ........... 1G6-167 

Biddeford, Maine, gravel pit in , plate showing.................... 14 

Newington moraine in ... ......... , ... . . . ............. . .. . 12,14--15 

Biddeford granite, distribution and character of, in southwest•~rn 

Maine ... ...... ....... ...... .. .. ....... ...... ....... 176-177 

Big Black River, Miss., relations of, to other rivers ... , ........ 157-158 

Bliss sandstone, distribution and character of, in New Mexico .... 32- 33 

plate showing ... . ... ... ...... ........... .... ....... . . . . . . . . . 32 

Boulders, in Mississippi colluvium, distribution and lithology of 142-143 

history of. .............. ·. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 

source of................. . ....................... . ........... 143 

Bowen, C. F., Stratigraphy of the Hanna Basin, Wyo ........... 227-235 

Bowie, Alexander, cited ............. . ............ . ...... ... .'..... !5 

Brookhaven terrace, Miss., description of. .. .'................. .... 155 

Butts;Charles, acknowledgment to ........ :. .................... 185 

Buxton, Maine, gravel deposits in ................................ 25-26 

c. 

Caballos Mountains, N. ~fex., Bliss sandstone in................. 33 

El Paso limestone in. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 

Fusselman limestone in .... ... .. . .. ... ' ....................... 41-42 

lower Mississippian limestones in... . . . . . . . . . . . . . . . . . . . . . . . . . . 48 

Montoy<~ limestone in ...... .. .. . ............. . ..... ·...... . . . . . 38 

Percha shale in ............. .. .......... : ........... . ......... 44--4!5 

west face of, plate showing........ .. ................... . . . . . . 34 

Cambrian system, geneml features of, in southern New Mexic<•... ·32 

Canton terrace, Miss., description of. ................. ·· ......... ;. . 156 

Cape Elizabeth formation, distribution and character of, in southwe.>tern Maine. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 

Capitol Dome, N.Mex., phte showing .......... . ............. : .. 3-1 

Carboniferous system, general features of, in southern New MeJ:iro 46-47 

Casco Bay group, character and relations of, in southwestern 

Maine ................................... c ••.•••• . . . 17{}-172 

Chamberlin, T. C., cited ........................ , ......... . 

and Salisbury, R . D., cited ...... , ........... .... : .. : .. 

Chimneys, formation of, over burning coal beds ........... . 

Chipola River, Fla., sections on ....... ." ................... . 

. Chonetes jerseyensis zone of the Keyser limestone, sub zones of.. 

125 

130 

5 

109-111 

19{}-191 

Page. 

Cinrw,momum hesperium Knowlton, n. sp., description of. ....... 88-89 

plate showing.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ." . . 106 

Cinnr:~momum? sp. , description of...... . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 

plate showing..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 

Citronelle formation, terrace deposits.correlated with, in Mississippi.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132A39 

Clark, W. B, acknowledgment to ...................... ·..... . . . . 185 

Clark's Mill, northwest of New Bloomfield, Pa., section at. ..... 214--216 

Coal, analyses of.................................................. 3 

spontaneous combustion of.. . . . . . . . . . . . . . . . . . . . . .. . . . . . . . 2-4 

Coal-bearing formations, tacks of ..... . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6 

Coal bed on Custer Creek, Mont., plate showing................... 4 

Coal beds, burning of, action of gases from........................ 4--5 

burning of, causes of.......................................... 1-4 

chemical changes in rocks produced by.................... 8-10 

effects on overlying st:cata produced by................... 4-5 

underground limit of..................................... 4 

Coeymans limestone member of the Helderberg limestone, correlation of... . ....................... . ...... ... ..... ...... 199 

nature of.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 

Collier, Arthur J.,.and Thorn, W. T., jr., The Flaxville gravel and 

its relation to other terrace gravels of the northern 

Great P lains .................................... ~ .. 179-184 

Colluvium, Mississippi, analyses of. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 

Mississippi, exposures of, plates showing...................... 142 

general nature of.......................................... 142 

.pebbles and boulders In ................................ 142-146 

plate showing........................................ 143 

recent deposits resembling, plate showing ............ ·........ 142 

use of term ............................... ·.................... 141 

Conant, E. T., acknowledgment to ............................. : . 179 

Conglomerate, significance of ................................... 232-233 

Cooke, Charles Wythe, acknowledgment to... .. . ............ ..... 61 

The stratigraphic position and faunal associates of the orbitoid 

Foraminifera of the genus Orthophragmina from 

Georgia and Florida ................................ 109-113 

Cooks Range, N.Mex., Bliss sandstone in........................ 32 

El Paso limestone in ...... ...... : ............ ·.· ...............• 34-35 

Fusselman limestone in. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 · 

Gym limestone in. .... . ...... .. .... ... ..... . ................ . 54 

lower Mississippian limestones in............................. 48 

Magdalena group in ..... . ................. , ... : ........... -... 53 

Montoya limestone in ........................................ 37-38 

Percha shale in ........ . ........................ = . . . . . . . . . . . . . 44 

Coosa peneplain, probable position of, in Mississippi ...... . ..... 153-154 

Creep, use ofterm................................................ 141 

Cretaceous deposits, residuum of, from Mississippi, analyses of.. 137 

Crider, A : F., cited .......... . ............................... ,:. .. 129 

Cushing granodiorite, distrihution and character of, in southwestern Maine... . .......... .. ........ ................ 176 

Cushman, Joseph Augustine, Orbitoid Foraminifera of the genus 

Orthophragmina from Georgia and Florida .......... 115-124 

Cypress Hills, Canada, Oligocene beds in......................... 183 

D. 

Dalmatia, Pa., section south of ......................... ' ....... 216-220 

Darton, N. H., A comparison of Paleozoic sections in southern 

N.Mex . ...... .. . . ..... . ......... ..... ....... ......... 31-55 

Dennstaedtia fremonti (Hall) Knowlton, n. comb., description of. 83 

plates showing ....... .. . . . .. .................. .. ... . ... ...... . 98,99 

Devonian system, formations of, in southern New Mexico ........ 44--46 

Dewalquea pulchella Knowlton, n. sp., description oL ............ 90-92 

plates showing .......... . ....................... ' .......... 104, 105 

Diamond Island slate, distribution and character of, in southwestem Maine ....... _ .............. ." .................. : 17D-171 

237 
238 INDEX. 

Page. 

Dov:er, N.H., Newin n moraine in ........................... 12, 1&-17 

Dramage, modification of, in Mississippi. ..... . .. .. . .. ......... 15&-160 

Dryandroiileslanceolata Knowlton, n. sp., description of.. ......... 89-90 

plate showing. . . . . -. . . . . . . . . . . . . . . . . 102 

Dryopteris coloradensis owlton, n. sp., description cf........... 83 

plate showing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 

E. 

El Paso limestone, ag and correlation cf. . . . . . . . . . . . . . . . . . . . . . . 3&-37 

distribution and c racter of, in southern New Mexico. :. . . . . . 34-37 

Eliot, Maine, _gravels a ' d sand in, plate showing.................. 24 

outlying mqrainal eposits in ... ................... :.......... 25 

Eliot slate, distributio and character of, in southwestern Maine 

and southe stern New Hampshire .................. 169-170 

Eo.cene deposits·, resid um of, from Mississippi, analyses of...... 137 

Equisetum sp., descrip on of. ............................ , .. . ,... 85 

plate showing... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i01 

Exeter diorite, distrib ion and character ·of, in southeastern New 

Hampshire .......... · ............ : .. ......... : . . . . .. . 176 

Falmouth quartzite, 

westernM 

F. 

character of, in south175 

Favosites helderbergiae ar. praecedens zone of the Keyser limestone, natu e and subzones of. ........... ~ ......... 191-192 

Ferns, species of, in th Frontier formation ... · . ........... .. ..... 78-79-

Ferris formation, natur and correlation of. .................... 230-231 

~;~~~t~:nX:~t~:::~ .·.·. ~ :.·.·.·.: ::::::::::::::::::::::;:::::: :··232-:! 

Ficusfremonti Knowlt n, n. sp., description of. ...... ·............ 87 

Fic! :~~ ,s~~:~:tl~; ~ ::::::::::::::: :: :::: :::::::::::::::: : ::. 02' ~; plate showing. . . . . . ............. _ ..................... _ . . . . . . 103 

Fic;:a::;h~=t~~~. ~:::::::: :.:::::::::::::::::::::::::::::::: ~~ Flaxville, Mont., railro d cut west of, plate showing ..... _........ 183 

Flaxville grayel, cross bedded, near ·west Fork; 1.1ont., plate 

showing ......•.................. _ .. _ . _ . __ ... _ ... ·. __ . . 182 

nature and distrib tion of.. ................ _ .. ... _ 179-182,183 184 

northwest of Ophei , Mont., plate showing ........... .. _.... '182 

Flaxville plateau, Mon ., plates showing ................... :..... 182 

Flint Ri\·er, Ga., fos&i,ls collected on ...................... _ ..... 111-112 

section on.......... . ......... · .......... _ .............. _.: ... ·. 111 

Florida Mountains, N. ex., Bliss sandstone in. .. 32 

El Paso limestone · ....................... _ .. :::::: ::::: : :: : 34 

~: ::e~J~:e:~. ~ -i~:::::::: :·::: :-::::::::::::::::::::::::: 53-!~ Montoya limestone ................... _ ............... _: ... 37-38 

Pcrcha shale in... . . . ................ _ ... .......... _ ... _ .. . _ . 44 

Foraminifera, orbitoid, escription,s of.. .. _ .... __ ....... ~. __ .... 115-118 

orbitoid, genera oL ............................. _ ......... _. 115 

plates showing ....... · ...................... -. . . . . . . . . . . . 120-124 

relations of.. ........................ :._ ........... _. __ . 109-113 

Fort Union formation, ccurrence of, in the Powder River basin 

Wyo ............................ .. .................. : 58-60 

Fossils, occurrence of, i Canada ....................... : ... 183 

occurrence of, in Fl rida ............................... 109-111,112 

in Georgia ......... · ........................... __ . __ .... 111-112 

~~ ~~~~:~~~~-- ::::::::::::::::::::::::::::::::::::::: -~~~~~~;~ in New Mexico. . .. . .... ... . . . . . . . .. . . . . . . . . . . . 32, 

33, 36, 39-40, 41, 42, 43, 45-46, 50-52, 53·, 54, 55 

.....••... 185, 186, 188, 189, 190, 191, 192, 193, 194, 

195, 196, 197, 198, 199, 200-203, 204-225 

in Wyoming... . ....................... 57, 58, 59, 73-94 230 231 

Page. 

Frontier formation, age of. ......... : ............................ : 75-77 

deposition of, conditions during ............................. 79-80 

flora of, biologic aspects of.. ................• : ................ 78-79 

plates showing .......................................... 9&-107 

fossils collected from, near Cumberland, Wyo., list of. ..... 77-78 

in Wyoming, insects in. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 

plant-bearing shale in, plates showing........................ 74 

Fused rock, core of, plate showing ............ ·.................... 4 

Fusselman limestone, distribution and character of. .............. 41-43 

·G. 

Gases, occluded, influence of, on the spontaneous combustion of 

· coal.................................................... 2-3 

Gases from burning coal beds, action of.. ............ :. . . . . . . . . . . . 4-5 

Gidley, J. W-., fossils determined by ....... .. ......... 58, 59;180-181, 231 

Gilmore, C. W., fossils determined by............................ 231 

Girty, G. H., acknowledgment to................................ 49 

fossils determined by .............................. 45, 50-51, 52, 53,54 

Gonic formation, distribution and character of, in southwestern 

Maine and southeastern New Hampshire ........... 172-173 

relations and age of.. ...............•.................... : .. 174-175 

Goodfortune Canyon, N. Mex., view northeastward in, plate 

showing . . : ............. .' . .. . : .... :....... .... .. ... ... 33 

Gorham, Maine, gravel deposits in. . . . . . . . . . . . . . . . . . . • . . . . . . . . . . . 25-26 

Granit~s, distribution and character of, in southwestern Maine and 

southeastern New Hampshrre ... , •.......•.•.•.•.•. 17&-177 

. Graphic mine, N.Mex., Kelly limest.one at, plate showing·....... 37 

Gravel and sand beds, cemented, near Scobey, Mont., plate showing ......••................... ;........................ 182 

Great Pine Ridge, Wyo., plate showing ..... :.................... 58 

rocks forming. . . . • . • • . • . . . . . . . . • . . . . . . . . . . . . . . . . . . . • . • . . . • . • • 58 

Greenland, N. H., Newington moraine in ................•. 13, 18,20-21 

Grovania, Pa., sectwn at. ..................................•... 224-225 

Gullies, old field, in Mississippi, plate showing................... 148 

Gym limestone, distribution and" character of, in southern New 

Mexico ...........•..................... .' ...••.••.•. .. 53-54 

H. 

Hall,James;cited ......................... ": ..................... 73-74 

Hampton, N. H. 1 Newington morainein ...................... 13,20-21. 

Hanna Basin, Wyo., folding and faulting in...................... 231 

formations in, chart showing nature of ................. . :. . . . 234 

section of................................ . . . . . . . . . . . . . . . . . . . 228-229 

source of sedimentary materials in.......... . . . . . . . . . . . . . . . . . . 234 

unconformities in, time and extent of.. ..................... 231-234 

Hanna formation, definition and nature of.. . . . . . . . . . . . . . . . . . . . . . 231 

deformation of. . : . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231 

soruce of material of...................... . . . . . . . . . . . . . . . . . . . . ·234 

Helderberg limesto!le in central Pennsylvania, correlation of ... 193-199 

distribution and character of. .•............................• : 188 

earlier correlations of. ......•........ .' ....... : ............ ~. 185-187 

fauna of, distribut1on of. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • . • • 199-203 

members of. ..•........................................•.•• 1~193 

sections of. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • • . . 204-225 

summary of conclusions en................... . . . . . . . . . . . . . . . . 204 

Hematite, production of, by burning coal bed .... -................. 9-10 

Hembrillo Canyon, N.Mex., view eastward out of, plate showing.. 33 

Highland Rim peneplain, probable position of, in Mississippi.. •. 152-153 

' Hilgard, E. W.,cited ..........•...•...•.••....•..............• 129,132 

Hillsdale region,.N. Mex., Percha shale in........................ 44 

Hitchcock, Charles H., cited ........•.•.....•......•.....•.•... 165-166 

Hueco limeston~, distribution a~d character of, in southern New 

Mexico .......... , ........ _ ............................. . 55 

I. 

plates showing ............................... 70-72, 9&-107

7 

119~124 Franklin Mountains, N Mex., Bliss sandstone in ............... :. 32 Igneous rocks, distribution and character of, in southwestern Maine 

El Paso limestone i and southeastern New Hampshire .................. 175-177 

Fusselman limesto in~::::::::::::::::::::::::::::::::::::: :~ illinois Central Railroad, profiles along, plate showing............ 148 

Montoya limestone ·n.. ....... ...... .. . . .. . . . . .. . . .. . . . . .. . . . 37 Insects in Frontier fossil leaves, evidence·of.... ...... ..... ....... 80 

Percha shale absent fro evidence of, plates showing .................•...........•••• 101, 103 

m .. · · · · · · · · · · · · .. · · · · · · · · · · ·-- ·....... 45 Iron in Mississippi residuum, accumulatwn of~ .............•.• : 14&-148 

Fremont, John C., c ted.·····................................ 73 in Mississippi residuum, bearing of, on Pliocene history...... 148 

discovery of fossils y, on Little Muddy Creek Wyo ........ 73-74, 78 native, productwn of, by burningcoal beds ... ········"······ 10 
INDEX. 239 

Page. 

Iron compounds, reddened and probably concentrated, plate showing ........................................... ~....... 147 

Iron sulphides, influence of, on the spontaneous combustion of · 

coaL ......................................... -....... . 

J. 

Jewell phylhte, -distributiOn and character of, in southwe.;tern 

Maine .... , ....... .. .......... , .... . ........... -.-. .. 171-172 

K. 

Katz, Frank J., .Stra.tigraphy in southwestern Ma1Ile and southeastern New Hampshire ...........•..•.•.•...... ... 165-177 

and Ke1th, Arthur, -The Newington mo-raine, Maine, New 

Hampshire, and Massachusetts .........••..•......... 11-29 

Keith, Arthur, acknowledgments to ........•.•.•.•••••••...•.... 165,185 

· Katz, Frank J., and, The Newington moraine, Maine, New 

Hampsbire, and Massachusetts.. . ......... ...... .. ... . 11-29 

Kelly limestone at Graphic mine, N.Mex., plate showing... . 37 

Kennebunk Valley, Maine, morainal deposits in ............ ,. 28 

Kennebunkport, Maine, Newington woraine in.............. 15 

Keyser limestone member of the Helderberg limestone, age or.. 198-199 

Chonetesjerseyensis zone of. ................................ 190-191 

correlat.on of. ........................................... . .. 193-199 

fauna of. ................................................... 197-198 

nature and faunal zones oL .. ........••.•... ..•............ 188-190 

Kindle, E. M., fossils determmed by............................. 45 

Kingsbury conglomerate southwest of BuffalO., Wyo., plate.showing. .... .... ... . .. ................•. ..•....... .. .. .. .. 59 

Kirk, Edwin, fossils determined by •.•..•..•..•.. ~ ......•..... 40, 43,46 

Kittery, Maine, outlying morainal deposits in ........ :._ ..... . . . . 25 

Kittery quartzite, distribution and character of, in southwestern 

Maine and southeastern New Hampshire ........... 168-169 

Klondike Hills, N. Mex., El Paso limestone in................... 35 

Montoya limestone in. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 

Knowlton, F. H., A fossil flora from the Frontier formation of 

southwestern Wyo .................................. 73-107 

fossils determined by ... ............................. 58,139,230,231 

Frontier fossils collected by ......................... : . . . . . . . . 78 

L. 

LaForge, Laurence, acknowledgment to..... . . . . . . . . . . . . . . . . . . . . . 165 

"Lafayette formation," derivation of; from terrace deposits .. : .. 133-134 

interpretations oL., ............................ "·. 128-130, 160-16l 

basis oL ........................................•. : . . . . 131-132 

material formerly included in, plates showing................ 132 

nature of. ..... ·............................................... 128 

Lake Valley district, N. Mex., El Paso limestone in .... . ........ . 

Fusselman limestone in. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 

lower Mississippian limestones in ............ .. ........ ....... 47-48 

~:r~~;:;!:~~-~~~-i-~:::::::::::::::::::: ::::::::::::::::::: ~: Lance formation, nature of.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 

sandstone bed with large concretions in, plate showing....... 58 

Laramie formation, origin of the term .......................... 227-228 

Larsen, E. S., acknowledgment to................................ 1 

"Leda" clay, nature and age of. ........... -.... : ................. 26,29 

Lesley, J.P., cited............................................... 186 

Lesquereux, Leo, restudy of Frontier fossils by................... 74 

Lewistown,· Pa., section at Mount Rock in ..................... 212-214 

Lignite, analyses oL ... ..... , ..................... _ ............ _ . ·3 

Limestones on granite, Sheep Mountain, N.Mex., plate show:lng. 36 

Loess from Mississippi, analyses of ............................ _ 135-136 

Lowe, E. N., acknowledgment to .......... _ .. __ ..... : .......... _ 125 

Loxley terrace, Miss., description of ...... _ ..... _ .... _ .... _ .... _ . . 156 

Luna County, N. Mex., Montoya limestone in ........ _ ...... .. _ .. 37-38 

McConnell, R. G., cited.......................................... 183 

McGee, W J, cited •............................................. 129--130 

Mackworth slate, distribution and character of, in southwestern 

Maine ........ _ ........................ _ .. _ ... _....... 172 

Magdalena group, distribution and character of, in southern New 

Mexico .............. -...............•...... 1 •••• _ • • • . • • . 53 

Page. 

Magdalena Mountains, lower Mississippian limestones in .... _ ... _ 48-49 

Magdalena group in .. _ .............. _ .... _ .. _ .............. _ . 53 

Maine, southwestern, field work in ...... _.- ..... ........... .. . _.·.- 165 -

southwestern, geologic sketch map of. ....................... _ 168 

stratigraphy of .............. __ ... _ .. _ .................. 166-175 

Mapleton, Pa., section in Swope quarry near __ ....... _ .... _ .... 209--212 

Marianna, Fla., sections near .. ___ ...... ____ ._._ ... _._ .......... 109--111 

Marine sediments, relation of, to the Newington moraine ....... _ . 26-27 

Maxon, W. R., acknowledgment to ..... _____ ._._ ._ ......... ,.. .. 80 

Medicine Bow formation, definition and nature of. ....... ___ . 229--230 

source of material in .... __ ... ___ ._ .. __ .. _. ____ ._ .. _ .... __ ... _. 231 

Meridian, Miss., fos.sils at._ .... _ .. _ .. _ ... __ .. _ ..... __ .. _ .. _ ... ____ 61-62 

fossils at, deposition of. .................... __ .. __ . __ .. ____ . __ 62-63 

plate showing .. __ ... _ ........ _ ... _. __ ._._. _ . ... ..... _ ... _ .. _._ 15 

Merriland Ridge, Wells, Maine, description of. ..... _ ...... .. ... _. 15-16 

railroad cut across, plate showing._ .... __ .. _ ..... __ .. _ .. _____ . 16 

Microtaenia paucijolia (Jiall) Knowlton, n. comb., description oL 82-83 

plate showirig ..... _ , .. _ ...... _ .. _ ... _ ..... __ .. _ .. _ .. ______ , _ _ -98 

Microtaeniavariabilis Knowlton, n. sp., description of .... _ ....... 81-82 

plate showing ............. .. ........ ......... __ ... _ .... __ . . . . 97 

Milk River, Mont., benches on ............... __ ._ ...... _ ....... 182-183 

escarpment surrounding bench on, plate showing ..... . ..... _ . 183 

Mimbres Mountains, N. Mex., Bliss sandstone in ......... , ....... 33 

El Paso limestone in .•.......... _ .. _ ... _ .. _ ... _ ...... _..... .. 35 

Fusselman limestone in ..................... _ ...... _ ..... __ . . . 42 

lower Mississippian limestones in .......... _ .. _ .. . _ ..... ____ .. 48 

MagdaleDa group in .............. _ ...... _ .. _ .. _ ... _ ......... _ 53 

Montoya limestone in ...................... _ .. __ ....... _ .. _ _ _ 38-39 

Miocene deposits, residuum of, from Mississippi, analysis oL .... : 137 

Mississippi, east-west and north-south sections of, plate showing . 126 

northern ap.d central, evenness of divides in . . ...... .. ... .. . 150-151 

peneplains in ...... . .......... ... . ..... .... ......... 151-154,161 

Pliocene time in, climate during .. ... .............. _ . __ .. _ 163 

deformation during................................... 161 

drainage modifications during ..................... _.. 162 

erosion during ........... ........ .. ........ .. .. ___ ._ 161-162 

knowledge oL ........ · ............ ·:.. .. . . . . ... . . . . . . 125 

life during..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 

physiographic data on ............................... _ 143 

sedimentation during................................. 163 

structural changes during............................. 100 

stages of erosion in ................................... _.. 150-151 

surface features of. ' ................ -....... ---..... ..... . -.. 149 

surficial materials from, analyses of .... _ .. . .. _ .. _ ... __ . . 135-137 

Mississippi River, lower, Pliocene course and volume cf. ....... 156-157 

Mississippi River basin, deposits in upper and. lower parts of, correlation oL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125-126 

Mississippian, lower, limestones, distribution and character of, 

in southern New Mexico ................... -... -... -.. 47-52 

Moisture. SeeWater. 

Monadnocks, formation of, in Mississippi. ........ -....... -. . . . . 149--150 

plate showing ..... _ . .. .... _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 

Montana, northeastern, map of. ..... . . -.... -. ..... ..... ~ : . --. --. 180 

northeastern, Pleistocene erosion in ............. -....... -. . 182-183 

recent erosion in ..............••.... ;_ ... ....... · ........ 182-183 

Montoya limestone, age and correlation of __ : ............... : .. -... 40-41 

distribution and character of, in southern New Mexico. . . . . . . 37-41 

Mousam Valley, Maine, morainal deposits in...................... 28 

Myrica nervosa Knowlton, n. sp., description cf. ....... .... ....... 85-86 

plate showing.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 

N. 

Nelumbo protolutea Berry, n. sp., description oL .. -.. -........... 64-66 

· plates showing ...... _ ...................... -. . . . . . . . . . . . . . . . . 70-72 

New Bloomfield, Pa., section northwest of. .. ....... -.- .. -.-.- .. 214-216 

New England coastal region, map of part of ........... .' ....... -. . 12 

New Hampshire, southeastern, geologic sketch map of............ 168 

southeastern, stratigraphy of. ....... : ...... : .. -- ........... 166-175 

New Mexico, map of part of. .... .. .... .. .. ...... ............ -.. -. 32 

southern, Paleozoic history in .................... --. -. ~ --. . . . 55 

New Scotland limestone member of the Helderberg limestone, 

correlation of. ....... _._ ....... . . ..... -.. --- ......... - 199 

nature of.. .... ................ . _ ....... .... ... -.. --- ....... : 192-193 
240 INDEX. 

Page. 

Newbury, Mass., Newington moraine in ................. 13,21-22,23-24 

Newingtc,n, N. H,, Newington moraine in ... : .. .... ~ .... 12-13,17-18,23 

Greenland, and Portsmouth, N. H., map of parts of ......... - 18 

Newington moraine, Maine, New Hampshire, Massachusetts, 

age of.. __ . ______ . ___ . __ . _______ .. _ . _ ........ __ .. __ . . . . 28-29 

deposition of, in the sea ....................................... - 27 

direction of ice flow forming ....... ~ . . . . . . . . . . . .. . . . . . . . . . . . . . . 27-28 

features of. __ .... _ ....... _____ ._ ....... __ __ ............. , ..... 13-14 

field work on ... ------ .. -------- : ----------------------------- 11 

gaps in.--- -- --. - -. -- ---- .. --- -- - -- ---- -------- -. -- ---- -:- -.. · - 28 

inner slope of, plate showing........ . . . . . . . . . . . . . . . . . . . . . . . . . . . 17. 

location and disposition of.. ....... .. . : . ..... ......... -.. .. -- - 12-13 

northward extension of .................. . ............. ~. . . . . . 25--26 

recessional nature of. ................ _ .............. , . ---.... --- 28 

region of, character of. ................. --- ... · ..... ----- .. ----. 11-12 

relation of, to marine sediments ............... · .............. - 2&--27 

to roches moutonnees.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 

to tilL ....... __ ..... ___ .......... · .... __ ................... 26 

-southward extension of, possible ..................... -....... - 25 

summary of report on ...... -.......... . ............... -.. . . . . . 2) 

North Hampton, N.H.; Newington moraine in .................. 13,20 

North Park formation, nature of. ................. -.---.-..... .. . 231 

position. of ...... : ............................ -... -- . --. . . . . . . . 231 

0. 

"Orange sand," use of the term . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128-129 

Ordovician system, generalfeatures of, in southern New Mexico... 34 

Orthophragmina, faunal associates of ............... -............. 112-113 

americana Cushman, il. sp., description of ................... · 116 

plates showing ...... ---------- ..... ---.. . .............. 120--122 

jlintensis Cushman, n. sp., description of ................... 115--116 

plate showing ........ --, .. -.--------- ... -..... .. ......... 120 

florid ana Cushman, n. sp., description of...................... 116 

plate showing ................... -. . . . . . . . . . . . . . . . . . . . . . . . 120 

georgiana Cushman, n. sp., description of ........... . ...... _. . . 117 

plates showing ... -.---------.------- ................ . .. 121-123 

mariannensis Cushman, n. sp., description of. ........ · ..... _ 115--117 

plates showiJ?g .... -.- . -.... --- -. -- ---- .. -. . . . . . . . . . 120, 122,-124 

var. pa pillata Cushman, n. var., description of.._. ______ . . 117 

plates showing ..... ·.c·-- -- -- ----- .. -- .. . ......•.. __ 123--124 

va.ughani Cushman, n. sp., description of .......... __ .. _______ 118 

oxford,~!:.:~;;:~~-;~~t-f~~~;;_~~::: ::::: ~::::::: :::::::::::::: _ ~~; 

P. 

Paige, Sidney, cited .. -... --.-----.------.- .... ------- .... · .•. ... .. 32--33 

Paleozoic rocks, irregularity of, in N" ew Mexico ...... ...... _ .... _ _ 31 

on granite at Capitol Dome, N. Mex., plate'-showing. _ ... _ _ _ _ _ _ _ 34 

Palmer, Chase,analysis by ................................ _ .. ____ 9 

determination of iron by ......... -- -.. -- ............ ____ .. ___ 14S 

Palomas Gap, N.Mex., fault in limestone at, plate showing .. ___ . 35 

Peale, A. C., Frontier fossils collected by ...... · ............ _ ... _._ 78 

Pearl River, relations of, to Big Black River, Miss ..... __ .. ______ 157 

Pebbles, hollow, of iron oxide, ongin of ... -- .......... -.· _. _____ ._ 138 

hollow, plate showing .. ---.-- ---------.- ................. '. . .. 138 

in Mississippi colluvium, distribution _!lnd lithoiogy of._ . ~ _ _ 142--143 

history of. ... -.-.- .. ---.-.---.------- -.. .. .. . ...... .. ·._.. 143 

source of. .. ------------------------------- . .... "·......... 113 

Peneplains in Mississippi, plate showing .. . . .... ..... .. ... . ... _... 149 

in Mississippi, warping of .... --- --- ---.. .......... ..... ... __ . 154 

Percha shale, age and correlation of.. .................. , _ .... _ .. __ 46 

in southern New Mexico, general relations of ....... __ . .. ___ .. 44--46 

Phyllites dentata Knowlton, n. sp., description of ............ __ ... 94 

dentata Knowlton, n. sp., plate showing ....... ~ ....... ___ .... 102 

jicifolia Knowlton, n. sp., description of ...................... · 93--94 

plate slwwing ... -- ---- --- --- . --- .. -. . . . . . . . . . . . . . . . . . . . . . 103 

frcmonti Unger, exclusion of, from Frontier flora.............. · 94 

sp., description of. ............... -- . . . . . . . . . . . . . . . . . . . . . . . . . . 94 

plate showing ........... -.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 

Physiographic history, data needed for dec~phering............... 148 

Pine Hill Cemetery, Dover,N. H., Newington moraine in ..... ___ 15--17 

sand pit in, plate showing ... --- .... ---....................... 17 

Pleistocene or Pliocene gravel, occurrence of, in Uontana ... 182,183--184 

Pliocene terr~ce materials from 1-Iississippi, analyses of. .... 134,135--137 

Page. 

- Pliocene time, possible record of, in Mississippi ......... --- 142,145--147 

Pocket-like features in Mississippi,' plate showing ...... ---.---.--- 143 

Portsmouth,N. H., gra:velpit on Middle Road in,plate showing.. 24 

moraine gravel in, plate showing ..... --- ........ '--- .. ------- 18 

Newingt_on moraine in ___ ... .. ................... --. 12--13,18-19,23 

Wiggins gravel pit in, plate showing .............. ---------.: 19 

Powder River basin, Wyo., stratigraphy of. ............... --- -.-. 57--60 

Pre-Pliocene formations in :Mississippi, difficulty of identifying. 127-128 

Pumpkin Buttes, Wyo., rocks forming ...................... -. . -- 58-59 

Pyrite, influence of, on the spontaneous combustion of coaL ..... - 2 

Q. 

Quercus stantoni Knowlton, n .. sp., description of ................ - 86-87 

plate showing ........ : ...... . ......................... : .. . ... 101 

R. 

Reeside, John B., jr., "The Helderberg limestone of central Pennsylvania ............. ---.---.-- .. -.. . --- ..... -- .. --. 185--225 

Residuum in :Mississippi, general nature of.- . .... ·............... 146 

in Mississippi, iron content of. ..... : -- ..................... 145--148 

weathered, pll~.te showing ............ : . . . . . . . . . . . . . . . . . . . 146 -

iower, use of term ... -~ ........ -- .. ,----------- .. ---- ....... 141,146 

upper, use of term·., ... ---··-·--····---------·---.-·-.------ 141,146 

Rindgemere formation, distnbution and chltracter of, in southwestern Maine and southeastern New Hampshire .. 173-174 

relations and age of.. ..•.......• -- ... -.. --.. . . . . . . . . . . . . . . . . 17 4~175 

Robledo Mouritain, N.Mex., Fusselman limestone in ... __ ....... 42 

Roches mm!tonnees. relation of, to the Newington moraine ...... - 26 

Rogers, G. Sherburne, analyses by ....... -: ....... . :............. 9 

Baked shale and · slag formed by the burning of coal beds .. _ _ 1-10 

Rogers, H. D., cited ...... --------------------------- .. ------.-... 185 

Rye, N.H., Newington moraine in ........ --- ... .. _, .......... 13,19-20 

sections of wells in ........... - --.. -------------' .... -. . . . . . . . . 23 

s. Saco, Maine, diorite in.~ ........ ---·---·-- --- ------------ ----- . .. 174 

morainal ridges in.-............ --------------------.------.... 25 

Newington moraine in ....... ---- --. -. ----- ---- -. -. -. . . . . . . . . 12, 13 

Sacramento Mountains, N. Mex., Bliss sandstone in ...... __ . __ . _ . 36 

El Paso limestone in .... --- -.- . --- --- ------ ----. -- . -. . . . . . . . . 36 

Fusselman limestone in .. -------,.--._.------- ----- .. ......... 43, 45 

lower Mississippian limestones,in . ... -..... , .. _ ....... .... .. ___ 49-50 

_ Montoya limestone in .......... , ...... -. -- -. . . . . . . . . . . . . . . . . . 39 

west front of, plates showing ... ------ --- -- -- --. . . . . . . . . . . . . . . 50, 51 

Salisbury, N.H., Newington moraine in .. --.--- ................ _ 13,21 

Salix cumberlandensis Knowlton, n. sp., description of. . . ___ . . ____ 86 

cumberlandensi-s Knowlton, n. sp., plate showmg· ... _. _ _ _ _ _ _ _ _ 106 

frontierensis Knowlton, n. sp., description of.. .•. ___ . _ . _: _ _ _ _ _ 86 

plate showing.- . -- . -.. --.. ----- -- ---- .. -- ---- . -. . . . . . . . . . . 103 

Salmon Falls Valley, Maine and New Hampshire, morainal deposits in ....... ----,.-.---------- ................... _ 28 

San Andres Mountains, N.Mex., Bliss sandstone in ... _._ .. _._____ 33 

El Paso limestone in .. --. ---. -. -. -. --. ---------- --. : . . . . . . . . . 36 

Fusselman limestone in .. ---. --- ------ ---- . -..... . .. .- ..... _ . _ 42--43 

lower Mississippian limestones in--- -. -.............. ~ ... ___ . . 49 

Montoya limestone in .. -. --- -- ---- --. ---- ... , ............. _ . _ 39 

plates showing ...... -.. -- . -- . ------ ---................ _ _ _ 33, 36 

Sandia Mountains, N. Mex., west face of, plate shoWing_ . _ .. _ _ _ _ _ 32 

Sandstone, effects of baking on.--.--------- ......... , ......... __ . 6 

-Sardis terrace, Miss., description of. •. .•.. .. . . : .......... ____ .. . 155--156 

Scarboro phyllite, distribution and character of, in southwestern 

Maine ... -.... -. ------. ---------. -. -. . . . . . . . . . . . . . . . . . . 171 

Scobey, Mont., section of well' southwest oL ... . ..... __ ... __ . _ _ _ _ 181 

Seabrook, N.·H., Newington moraine in .... . , ....... . . .. . . ___ . ___ 13,21 

Sears, J~ H., cited ................. -·-·---- ......... ---- ....... _._ 24 

Sebago Lake, Maine, moraine on .... --- .. .. . __ . __ .... ... ... . __ __ . 24 

Selinsgrove Junction, Pa., section at ....... ' . .. ... . .......... _ . . 220--224 

Shale, baked, analyses of. .......... .... , .................... _._ .. 9 

effects 'or baking on.-.. -.. -- ... --.------.-------'-.-------.--- 6 

plant-bearing, near Cumberland, Wyo., plates showing . . .. ___ 74 

"Shandon quartzite," disuse of term in New Mexico._._ .. . _.___ 32 

Shaw, Eugene Wesley, The .Pliocene history oi northern and 

central Mississippi.. ................ . ........ __ :. __ .' 125--163 

Sheep Mmmtain, N.Mex., plate··showing........................ 36 

Sierra:Cuchillo, N: Mex., plate showing .............. . ....... _.___ 35 
INDEX. 241 

Page. 

.Sierra Ladrones, N.Mex., lower Mississippian limestones in ... -... 50 

Silurian system, formations of, in southern New Mexico .......... 41-43 

Silver City region, N. Mex., Bliss sandstone in ................... 32-33 

El Paso limestone in ...... , ....................... ~ . . . . . . . . . . 35 

Fusselman limestone in ..................................... . 41 

Page. 

Thackers Mountain, :Miss., location and height of.. ... ~..... ..... 149 

Thorn, W. T., jr., Collier, Arthur J., and, The Flaxville ·gravel 

and its relation to other terrace gmvels of the northern 

Great Plains.···'···························: .. -..... 179-184 

Tombigbee River, Miss., relations of, to Tennessee River ...... . 158-160 

lower Mississippian limestones in ............................ . 48 Tonoloway limestone, correlation of.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193 

Magdalena group in ......................................... . 53 fauna of. . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199-203 

Montoya limestone in .................. . ...... .. ............ . 

Percha shale in . ............ ................ .. ... . ............ . 

Slag, glassy, production of, by burning coal beds ......... ....... . 

glassy, with spherulitic structure, photomicrograph of. ...... . 

holocrystalline, photomicrographs of ............ . ... .... .... . 

recrystallized, production of, by burning coal beds .......... . 

Smilax? coloradensis Knowlton, n. sp.,description of.. ........... . 

plate showing ............................................... . 

Snake Hills, N. Mex., El Paso limestone in ...................... . 

38 

44 

6 

6 

6,8 

6-8 

85 

101 

35 

Montoya limestone in ............................ ·. . . . . . . . . . . . 37-38 

Soil, special use of term ........................... ·. . . . . . . . . . . . . . . 141 

South Berwick, Maine, Newington moraine in ....... . ......... . 16 

Spring Point greenstone, distribution and character of, in southwestern Maine. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 

Springer, Frank, fossils determined by. . . . . . . . . . . . . . . . . . . . . . . . . . . 50-51 

Spurwink limestone, distribution and character of, in southwestern Maine ....... ............ .. ~ ..... ·_ . . . . . . . . . . . 171 

Stanton, T. W., cited............................................ 76 

fossils determined by... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 

Frontier fossils collected by. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 

Staphylea fremonti Knowlton, n. sp., description of............... 93 

plates showing . .... .................... ............ ........ 100, 101 

Stream cutting, influence of, on the burning of coal beds......... 3 

Summerville Mountain, Miss., location and origin of............. 14:J 

Surficial materials, upland, divisions and designations of. ..... 13~142 

Swartz, C. K:, acknowledgment to._.............................. 185 

T. 

Tapeinidium? undulatum (Hall) Knowlton, n. comb., description of. .. : .......... · ....... -. . . . . . . . . . . . . . . . . . . . . . . . . 80-81 

plate showing.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 

Tennessee River, possible former courses of ........ , ...... . .. .. . 158-159 

Terrace deposits correlated with the Citronelle formation, age 

and correlation of. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 

constitution of. ....... ~ .................................... 134-138 

fossils in . ..... . .... .................. : .,......... .. ...... . ... 139 

location of.. ........................................ : . . . . . . . 132-134 

number arid names of. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 

pebbles in, nature of. ........ .... .... ...... ......... . . :... . .. 138 

relations of. .............................................. :... 139 

stratification of... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138-139 

Terraces in Mississippi, general features of. ........ .-........ , . 154-155 

stratigraphic relations of, plate showing. . . . . . . . . . . . . . . . . . . . . . 133 

unevenly bedded and gravelly portions of, plate showing.... 139 

warping of .............................. ·..................... 156 

general features of. ......................................... 181-188 

sections of.... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204-225 

summary of conclusions on.................................... 204 

Towow formation in southwestern Maine, distribution and character of. ......... .. .......... .. .......................... 174 

relations and age of. ....................................... 174-175 

Trap dikes, distribution and character of, in southwestern Maine 

and southeastern New Hampshire.................... 177 

Tres Hermanas Mountains, N. Mex., Gym limestone in... .... . .. 54 

Trichopteris, exclusion of, from Frontier flora..................... 94 

Tyrone, Pa., section at Lincoln and Fifteenth streets in ........ 204-206 

section on Pennsylvania A venue in .. ... · ............. ...... _ 206-209 

u. 

Ulrich, E. 0., acknowledgment to . . .. .. ..... '..................... 185 

fossils determined by ...................................... 39-40,43 

Upham, Warren, cited .... : ................................... 21,22-24 

V. 

Vandalia dam, Milk River, Mont., plate showing ............... ,. 

Veatch, A. C., cited ....... ·'· ....................... : ........... . 

Frontier fossils collected by .... .................... : . ....... . 

rediscovery of locality of Frontier fossils by ................. . 

Victoria Mountains, N.Mex., El Paso limestone in ............. . 

Fusselman limestone in ..................................... . 

Montoya limestone in ....................................... . 

w. 

183 

75 

78 

74-75 

35 

41 

37-38 

Walcott, C. D., fossils determined by ...... .................. --- .. 33 

Wasatch formation, occurrence of, in the Powder River basin, 

Wyo .. ~ .. ....... ......... .... ........ '·· ..... . ....... 58-60 

Wash, use of term .......................... _...................... 141 

Water, influence of, onthe spontaneous combustion of coal...... 2 

Wegemann, Carroll H., Wasatch fossils in so-called Fort Union 

beds of the Powder River basin, Wyo., and their 

bearing on the stratigraphy of the region ........... . 57-60 

Wells, Maine, Newington moraine in ....... ... ................... 15-16 

Westbrook granite, distribution and character of, in southwestern 

Maine ........................................ ·........ 175 

z. 

Zamia mississippiensis Berry, n. sp., description of .............. 63-64 

0