MKl'AUTMKNT OF Til tt ! N T K I,'I O IJ

HUKLKTIN

u N IT Mi) STATION

GEOLOGICAL SURVEY

No. HI

COl.'KKl.ATJON I'AI'ICIW CAMJShM/VN

\V A S i I 1 X (J T l) N

,( I () V JO i; N \\ K XT I' i; 1 N T 1 N < i U !< K J (' 10 

1 S J| 1

DEPARTMENT OF THE INTERIOR

BULLETIN

OF THE

UNITED STATES

GEOLOGICAL SURVEY

No. 81

WASHINGTON

GOVERNMENT PEINTINO OFFICE 

1891

UNITED STATES GEOLOGICAL SURVEY

J. W. POWELL, DIKECTOK

CORRELATION PAPERS

CAMBRIAN

CHARLES DOOLITTLE WALCOTT

WASHINGTON

GOVERNMENT' PRINTING OFFICE 

1891

CONTENTS.

Page.

Letter of transmittal ................................................ .... 13

Outline of tins paper ........................................................ 15

CHAPTER I. Introductory ........................ ......................... 17

Literature .............................................................. 19

List of authors and year of publication .............................. 19

List of papers by dates........................................ ... 22

CHAPTER II. Historical review of the geologic and paleontologic work ...... 49

Atlantic Coast Province ................................................. 50

Newfoundland...................................................... 50

Nova Scotia......................................................... 5G

New Brunswick and Cape Breton..................................... 59

Maine .............................. ........... ................. 68

New Hampshire..................................................... 70

Eastern Massachusetts ......................................_..... 72

Paleontology ......................................................... 78

Newfoundland ...................................................... 78

New Brunswick and Cape Breton.................................... 80

Eastern Massachusetts .............................................. 88

Appalachian Province................................................... 91

Northern Appalachian district................................ ... 91

Granular Quartz................................................ 91

Red Sandrock................................................... 96

Georgia slates .................................................. 98

Potsdam Sandstone................... .......................... 113

Canadian extension............................................. 114

Southern Appalachian district....................................... 122

New Jersey..................................................... 122

Delaware ..............................................__..... 123

Pennsylvania ......... ............ .. .................. 124

Maryland....................................................... 133

Virginia .........-'... ................................. .... 133

North Carolina.................................................. 13d

Tennessee ........................................ .. ...... 139

Georgia. ........................... ........ ....... 144

Alabama........................................................ 146

Paleontology ..................... .. ......... ............... 148

Northern Appalachian district......................... _........... 148

Southern Appalachian district.......'................................ 154

New Jersey, etc ................................................. 154

Tennessee....................................................... 154

Georgia......................................................... 155

Rocky Mountain Province .............................................. 155

Utah and Nevada................ _................_ ....a......... 155

Idaho .............................................................. 1G1

5
6 CONTENTS.

Page. 

CHAPTER II Continued.

Montana...... .......................--....---.--......-....---. - - 162

Canadian extension ................................................. 163

Paleontology ........................-..----. .---.....----- -...-- - 165

Interior Continental Province........................................... 171

Upper Mississippi area .............................................. 171

Wisconsin ...............................................^...... 171

Minnesota...................................................... 181

Iowa ........................... ............................. 187

Lake Superior sandstone... .................................. 188

Missouri........................................................ 199

Eastern border or Adirondack sub-Province .. .................... 201

Canadian Extension ................................................ 207

Western Border or Rocky Mountain sab-Province.................... 209

Colorado........................................................ 209

Wyoming.......................................I................. 211

Dakota......................................................... 214

Southwestern sub-Province.......................................... 216

Texas .......................................................... 216

Arizona ........................................................ 219

Paleontology ......................................................... 221

Upper Mississippi area .............................................. 221

Red sandstone of Lake Superior................................. 228

Missouri........................................................ 229

Eastern border or Adirondack sub-Province.......................... 229

Western border or Rocky Mountain snb-Province .................... 233

Texas .......................................................... 234

Arizona......................................................... 235

CHAPTER III. Nomenclature employed in the description of the formations.. 236

Cambrian............................................... . ......... 237

Tacouio ................................................................ 242

Taconiau................................................_............ 243

Primordial ........................................................._. 243

Potsdam................................................................ 244

St. Croix..................................................__......... 245

Madison ......_....................................................... 245

Mendota.................................... ........................... 245

Tonto .............................................................__. 245

Hamburg......................................... _................... 246

Secret Canon ............_......__...................._........... 246

Katemcy ..... ........_............................................ 246

Riley................................................................... 246

Hickory ................................................................ 246

Connasauga ......................._........_...._ ................ 246

Montevallo............................................................. 247

Choccolocco .................................. _....................... 247

Coosa .................................................................. 247

Rome sandstone..................................................... _. 247

Brotouian .............................................................. 247

Acadian ................................................................ 248

St. John's .. ..................................................._...... 248

Jouaunian .......__......................... ...................... 249

Georgia............................................................ -- 249

Granular Quartz... ......._..................... ...... ...... 250
CONTENTS. 7

Pago. 

CHAPTER III Continued.

Red Sandrock............................................_............ 250

Primal................................................................... 251

Chilhowee.............................................................. 251

Weisner .................................... ........................... 251

Ocoee................................................................... 252

Prospect... .......................................................... 252

Eastern and Western sandstone.......................................... 252

Lake Superior sandstone ................................................ 252

Potsdamic .............................................................. 252

CHAPTER IV. Summary of the present knowledge of the formations......... 253

Atlautic Coast Province...... ............................................ 253

Newfoundland and the adjoin! ng coast of Labrador.... .............. 253

Northwestern Newfoundland ................................ .... 253

Southwestern Newfoundland .................................... 256

Eastern and Southeastern Newfoundland ........................ 257

Nova Scotia.............. ........................................... 2G2

New Brunswick and Capo Breton .................................... 262

Maine .............................................................. 267

New.Hampshire..................................................... 267

Eastern Massachusetts .............................................. 268

Re'sum6...-.---..................................................... 273

Appalachian Province................................................... 274

Northern Appalachian district....................................... 275

Canadian extension ............................................. 285

Southern Appalachian district ...................................... 287

New Jersey ................................... .. .,.............. 287

Delaware'....................................................... 2H8

Pennsylvania................................................... 288

Maryland...................................... ................. 289

Virginia ........................................................ 290

North Carolina.................................................. 299

Tennessee....................................................... 299

Ocooo conglomerate......................................... 299

Chilhowee sandstone........................................ 300

Knox sandstone and shale................................... 301

Georgia......................................................... 303

Alabama....... .....-.......-.......;...-............-.......... 305

Rdsurao*......................................................... 308

Rocky Mountain Province............................................... 313

Utah and Nevada ................................................... 313

Idaho............................................................... 320

Montana............................................................ 323

Canadian extension................................................. 326

Rdsume'............................................................. 328

Interior Continental Province........................................... 330

Upper Mississippi Valley............................................ 330

Canadian extension............................................. 334

Lake Superior sandstone............................................ 335

Canadian extension............................................. 339

Missouri............................................................ 339

Eastern border or Adirondack sub-Province and its Canadian extension .............................................................. 341

Section at Potsdam ............................................. 34'2

Section at Chateaugay Chasm .............. M .................... 342
8 CONTENTS.

Page. 

CHAPTER IV Continued.

Section at Hemmingford........................................ 343

Section at Keeseville and in Au Sable Chasm .................... 343

Section at Whitehall............................................ 344

Section at Saratoga............................................. 346

Western border or Eocky Mountain sub-Province .........*.......... 347

SouthDakota .................................................. 347

Wyoming....................................................... 349

Colorado ....................................................... 351

Southwestern sub-Province ......................................... 354

Texas ........i.................................................. 354

Arizona.......................................................... 356

Ke"sume"..---... .................... .................. . 357

Synopsis of the Cambrian group......................................... 359

Base of Cambrian................................................... 362

Summit of Cambrian................................................ 362

Sedimentation of theCambrian group................................ 363

Subdivision of the Cambrian ........................................ 370

Comparison with the Cambrian rocks »f other countries ................. 373

Europe ............................................................. 373

Scotland............................................................ 376

Ireland............................................................. 377

China .............................................. ............. 377

India.............-.......-.....-.-..... ......................... 378

Australia....................................................... . 378

South America.................................. ................. 379

CHAPTER V. Problems for investigation and settlement..................... 380

Local problems ......................................................... 380

Newfoundland.....,................................................ 380

Nova Scotia ........................................................ 380

New Brunswick........................... ....................... 381

Maine and New Hampshire.......................................... 381

Eastern Massachusetts .............................................. 381

New York .......................................................... 381

Adirondack sub-Province ................. ....................... 381

Vermont............ ............................................. 381

Canadian extension................................................. 382

New Jersey .......................... .................. ....... 382

Pennsylvania .... .................................. ........... 382

Virginia............................................................ 383

North Carolina....................................................... 383

Tennessee .......................................................... 383

Georgia and Alabama ............................................... 383

Utah and Nevada................................................... 384

Colorado....................................................... .. 384

Eocky Mountains ............. ............._........._..._. 384

Arizona............................................................. 385

Upper Mississippi Valley ............ ...... ............ __ 385

Missouri........................... ...... ........ ....... 385

Texas............................................................... 385

Problems affecting our knowledge of the Cambrian group as a whole or in

large parts..---. ...................................................... 385

Problems of nomenclature and classification..--.......................... 388

The name............................................................ 388

The limit of the group....... ...1................................ 388
CONTENTS. 9

ijage.

CHAPTER VI. The criteria and principles used by authors in the correlation 

of the various parts composing the group, with observations on some methods

of correlation ............................................................. 391

Historical notes......................................................... 391

America............................................................ 391

Maclure ............ ....*. ................................. ...... 391

Eaton .......................................................... 392

Bigsby ......................................................... 39.")

James .......................................................... 396

Bakewell........................................... ............ 397

De la Beche..................................................... 398

Eaton .......................................................... 399

Conrad......................................................... 399

Hall................:..-.............. .......................... 401

Emmons........................................................ 403

Rogers.......................................................... 403

Safford ......................................................... 405

Canada............................................................. 40.r>

Logan.......................................................... 405

Newfoundland...................................................... 400

Dana............................................................... 407

Mississippi Valley................................................... 408

Hall............................................................ 408

Wincliell ....'.......................................---......... 409

Meek............................................................ 410

Rocky Mountains.................................................... 411

Whituey.................................................. ^..... 411

Bradley ........................................................ 411

Fortieth Parallel Survey ........................................ 412

Explorations and Surveys West of One Hundredth Meridian...... 412

Geological Surveys of the Territories ............................ 412

U. S. Geological Survey......................................... 413

Correlations with European formations.............................. 414

De Verueuil..................................................... 414

Hall......................................................'...... 415

Barraude....................................................... 416

Rogers ......................................................... 417

Bigsby ......................................................... 418

Agassiz......................................................... 419

Matthew ............. ....................................... 420

Methods of correlation .............................................. 421

Superposition................................................... 421

Organic remains ................................................ 422

Life zones .................................................. 424

Stage of evolution .......................................... 425

Life history................................................. 426

Contemporaneity and homotaxis............................. 427

Percentage of species........................................ 428

Lithologic character ............................................ 428

Unconformity................................................... 429

Miscellaneous................................................... 432

Homogeny...... ............................................ 432

Topographic features........................................ 434

ILLUSTRATIONS.

Page.

PLATE I. Map showing the distribution, by geologic provinces, of the Cambrian strata as shown by surface outcrops iu North America...... 358

II. Map to illustrate geologic provinces and relative thickness of the 

Cambrian rocks of North America, with theoretic sections of the 

Cambrian group at the close'of Cambrian time ................... 365

III. Hypothetical map of the North American contiuent at the beginning

of and during Lower Cambrian time............................. 368

FIG. 1. Typical sections of the Atlantic Coast Province ...................... 274

2. Typical sections of the Appalachian Province ........................ 311

3: Typical sections of the Rocky Mountain Province..................... 329

4. Typical sections of tbo Interior Continental Province.................. 357

5. Typical sections of the Interior Continental Province....... __... 358

11

LETTER OF TRANSMITTAL.

DEPARTMENT OF THE INTERIOR, 

UNITED STATES GEOLOGICAL SURVEY, 

DIVISION OP GEOLOGIC CORRELATION,

Washington, D. C., April 1,1891.

SIR : I have the honor to transmit herewith a memoir by Mr. C. D. 

Walcott, on the Cambrian of North America, prepared for publication 

as a bulletin.

The Division of Geologic Correlation was created for the purpose of 

summarizing existing knowledge with reference to the geologic formations of North America, and especially of the United States; of discussing the correlation of the formations found in different parts of the 

country with One another, and with formations in other continents; 

and of discussing the principles of geologic correlation in the light of 

American phenomena. The formations of each geologic period were 

assigned to some student already well acquainted with them and it was 

arranged that he should expand his knowledge by study of the literature, and by field examination of classic localities, and embody his 

results in an essay. The general plan of the work has been set forth 

on page 16 of the Ninth Annual Eeport of the Survey, and on pages 

108 to 113 of the Tenth Annual Eeport, as well as in a letter of transniittal to Bulletin No. 80 of the Survey.

The first of the series of essays resulting from this work, prepared 

by Prof. Henry S. Williams, pertains to the formations of the Carboniferous and Devonian periods, and constitutes Bulletin No. 80. 

The present essay is the second of the series, and others will follow.

Mr. Walcott finds that the American Cambrian includes three faunas, 

of which the first and third are of continental range, and that by the 

aid of these faunas the formations in the various geologic provinces 

may be classified into three divisions, an upper, a middle, and a lower. 

He finds also that these divisions may be homotaxially, and perhaps 

chronologically, compared with divisions of the European Cambrian. 

Very respectfully, your obedient servant,

G. K. GILBERT, 

Geologist in Charge. 

Hon. J. W. POWELL,

Director U. 8. Geological Survey.

13

OUTLINE OF THIS PAPER.

This work is a review, by one who is working in tbe Cambrian field, of the work of 

his predecessors, and of the results they and he have thus far obtained as he interprets 

them. It thus becomes historical and descriptive, and is a general statement of the 

principles upon which the correlations have been made in establishing the group.

Chapter i gives a statement of the principles upon which the delimitation of the 

group is based, a few brief remarks upon the nomenclature of the formations, and a 

list of the books and articles consulted in the preparation of this paper.

Chapter n gives a historical review of the geologic and paleontologic work that 

has been done in the four provinces in which the sediments of the Cambrian group 

occur. These are the Atlantic Coast Province; the Appalachian Province, which is 

. divided into the Northern Appalachian and Southern Appalachian areas; the Rocky 

Mountain Province, and the Interior Continental Province. The latter is divided 

into the Upper Mississippi Area, the Eastern Border or Adirondack sub-Province, the 

Western Border or Rocky Mountain sab-Province, and the Southwestern sub-Province of Texas and Arizona. Within each of the provinces the historical data are reviewed by the political divisions of States and Territories, and in British North 

America by provinces.

The historical review of the geologic work embraces all that has come within the 

knowledge of the writer of the descriptive geology of the rocks now referred to the 

Cambrian group. The paleontologic review includes only the mention of the genera 

and species described by the various authors.

Chapter in is a record of the names that have been employed to designate various 

formations. It is of an historical rather than a controversial character.

Chapter iv gives a summary of the present knowledge of the formations in each of 

the four geologic provinces, in the same arrangement as that of the historical review 

in chapter n. The attempt is made to give a concise statement of the present knowledge of the formations referred to the Cambrian group within each province. The 

paleontologic references are to the larger subdivisions of the fauna without mention 

of'genera or species. These will be described in special monographs, now in the 

course of preparation. At the close of this summary there is a synopsis of the Cambrian group, in which it is stated that the group is established by (a) the presence 

in the Rocky Mountain Province of 6,000 feet of limestone with an undetermined 

mass of quartzite beneath; (6) in the Appalachian Province by over 12,000 feet of 

quartzite, shales, slates, and limestones; (c) a continental distribution; (d) a characteristic, highly differentiated fauna. A table of the classification of the formations is 

arranged with the type formation of each subdivision at the head, while beneath 

are the formations correlated with it.

A map showing the geographic distribution accompanies this chapter ; also one 

on which the sedimentation is illustrated by vertical columns of strata. A section 

across the continent, with the base of the Ordovician fauna as the upper limit and 

the columns of strata arranged beneath it, reveals the presence of a great trough 

along the line of the Appalachians from Alabama to Labrador, and a second trough 

on the western side of the continent west of the eastern Rocky Mountain ranges. 

It is claimed that the great interior Continental Province was a land area during

15
16 OUTLINE OP THIS PAPER. [BULL. 81.

Lower and Middle Cambrian time and that the Cambrian Sea did not enter upon it 

until the beginning of Upper Cambrian time. A map based (PI. ui) upon this viewillustrates the supposed land area at the beginning of Cambrian time.

The base of the group is stated to be where the oldest known fauna that is referred 

to the Cambrian fauna occurs. The summit of the group is the transition from the 

Cambrian to the Ordovician fauna, or in the New York section between the Potsdam sandstone and the superjacent Calciferous formation. The rocks or sediments 

are described and the conclusion reached that there were geographic areas in which 

different types of sedimentation prevailed, and that as a whole the sediments were 

deposited in both shallow and deep waters on an ocean bottom that was being slowly 

depressed in relation to sea level.

The study of the fauna indicates that the group may be conveniently divided into 

three divisions, lower, middle, and upper. The evidence of the sedimentation and 

organic remains proves the presence of geographic provinces in Lower Cambrian time 

that became more strongly differentiated in Middle Cambrian time and less strongly 

marked in Upper Cambrian time.

The chapter concludes by notes on the Cambrian rocks of Great Britain, Europe, 

China, India, Australia, and South America.

Chapter v deals with problems for. investigation and settlement which are taken 

up, for the local problems, in the same order of presentation as the matter in chapters n and IV. The general problems respecting our knowledge of the Cambrian 

group, as a whole, or iu large parts, are discussed separately, as are the problems of 

nomenclature and classification. The latter includes a statement of the problems 

relating to the name and the limits of the group.

Chapter VI is devoted to the study of criteria and principles used by authors in the 

correlation of the various parts composing the Cambrian group, with observations 

on some methods of correlation. The first portion includes the historical notes, and 

is a review in chronologic order of the principles of correlation used by authors in the 

United States and Canada, and observations by authors upon correlation of American 

with European formations. This review shows that many authors have expressed 

sound views upon methods of correlation and that, with the exception of the additions made since the theory of evolution began to influence paleontologists, the 

addition to methods has been relatively small. Under the heading of methods of 

correlation, correlation by superposition, organic remains, lithologic characters, 

and unconformity are treated of at some length. Under organic remains are considered life zones, stage of evolution, life history, contemporaneity, homotaxis, and 

percentage of species. Reference is also made to homogeny and topographic features 

as elements entering into the problems of correlation.
THE CAMBRIAN GROUP OF ROCKS IN NORTH AMERICA.

BY CHARLES D. WALOOTT.

CHAPTER I.

INTRODUCTORY.

This report is an unfinished memoir. It is an account of the present 

knowledge of a great geologic group that will require prolonged investigation to bring it to the status in descriptive geology already attained 

by the superjacent members of the Paleozoic system.1

The history of the origin and application of the term Cambrian in 

geologic nomenclature is presented in connection with the description 

of the names that have been employed in the classification of the various 

formations characterized by the types of the "First or Primordial Fauna" 

of Barrande. The basal fauna, as now known, is that of the Olenellus 

zone; and the upper horizon of the group is drawn at the summit of 

the series characterized by theDikellocephalus fauna of North America. 

The delimitation of the group is based on the principles : (a) that the 

great geologic groups must rest on the broad zoologic characters of 

their included faunas, and not upon local stratigraphic breaks between 

certain series of rocks or upon local differences in sedimentation; (b) 

that the most reliable chronologic scale in geology is that afforded by 

the relative magnitude of zoologic change; and (c) that the geologic 

duration and importance of any system are in strict proportion to the 

comparative magnitude and distinctness of its collective fauna. 2

Geologic classification has been largely based upon the imperfections 

of the geologic record and an arbitrary assumption of breaks in the 

chain of sedimentation and life that are not of universal extent. Geologic continuity must have been a fact and the sequence of life and 

deposition continued uninterrupted on some portion of the earth from 

the earliest Cambrian time to the present day. Such continuity could 

not have existed in any one province, and it is doubtful if the complete 

record will ever be regained. In its absence the classification already

1 Iu tlie preparation of the historical portion I received material assistance from Pi'c^l Joseph F. 

James, who, talcing as a basis the bibliographic card-catalogue of Mr. N. H. Barton, prepared a aeries 

 of brief abstracts which guided me in my historical research. 

< 3-Lapworth, Charles. Geological Magazine, new sor., dec. II, 1879, vol. 6, p. 3.

Bull, 81 2 17
18 THE CAMBRIAN. [BULL. 81.

established is adopted and tben arbitrarily assumed whenever the original basis for it is cleared away by more perfect knowledge.

For convenience of description and geologic cartography, the geologic 

formation1 is taken as the primary unit of classification. The combination of these primary units forms the terrane, which may be composed of any number of geologic units. The groupings of the terranes 

form the groups, and the union of the groups the systems. Thus the 

Potsdam sandstone of the Adirondacks, the Dutchess County limestone 

of New York, the upper Knox shales of Tennessee, the Hamburg shales 

of Nevada, and many other formations unite to form the Upper Cambrian terrane. The union of the Upper Cambrian with the Middle and 

the Lower Cambrian builds up the Cambrian group. The combination 

of the Cambrian, Silurian, Devonian, and Carboniferous, forms the 

Paleozoic system.

The nomenclature of the formations of any group frequently expresses in local terminology the history of the development or evolution of knowledge of the group. For instance, the formations composing the Cambrian begin, in America, with the " Granular Quartz" and 

then follow the Potsdam sandstone, the St. John shales, the Chilhowee 

sandstone, etc. The plan of naming the formations from the locality 

at which they are best developed is a great safeguard and can be frequently adopted. For instance, the Potsdam sandstone of New York 

has its type locality at Potsdam in St. Lawrence County, where it can 

be readily identified. To say it is identical with the Upper Cambrian 

or St. Croix sandstone of the Mississippi Valley, with which it has been 

identified, and to speak of the latter as the Potsdam sandstone, is to 

practically state that they are synchronous. The use of the name St. 

Croix does not imply this. It enables the geologist to mention the 

formation without assuming a correlation that he may or may not believe in.

1 Dr. J. J. Bigsby states that "According to Deshayes ' a formation is a space of time represented by 

a certain number of beds, laid down tinder the influence of the same phenomena,' or, in other words, a 

formation is characterized by the constancy of its fossils." (On the Paleozoic basin of the State of 

New York. Part II. Classification of the Paleozoic strata of tbe State of New York. Quart. Jour. 

Gcol. Soc. London, 1858, vol. 14, pp. 428, 430.)
LITERATURE.

LIST OF AUTHORS AND YEAR OF PUBLICATION,

Adams (C.B.), 1845, 1846, 1847, 1848. 

Agassiz (Alexander), 1868. 

Agassiz (Louis), 1862. 

Ami (H.) and Sowter (T. W. E.), 1887. 

Aveline (W.T.); Salter (J.W.), and, 1853. 

. Bailey (L. W.), 1865, 1879. 

Bailey (L. W.) and Matthew (G. P.),

1872. 

Bailey (L. W.); Matthew (G. P.), and,

1869. 

Bailey (L. W.), Matthew (G. P.), and

Ells (R. W.), 1880. 

B;iily(W.H.), 1865. 

Bukewell (Robert), 1829. 

Barraude (J.), 1846,1852,1853,1860,1861. 

Barrande (Joachim), and Marcou (Jules),

1860.

Bayfleld (H. W.), 1829,1845. 

Beecher (C. E.) and Hall (C. E.), 1886. 

Bell (Robert), 1879. 

Bergeron (Jules), 1888. 

Bigsby (John J.), 1824, 1825, 1827, 1853,

1858, 1863.

.Billings (E.), 1860, 1861, 1862, 1865, 1872. 

Bradley (Frank H.), 1860,1872,1873,1874,

1875.

Broadband (G. C.), 1874, 1877, 1882, 1889. 

Brogger(W. C.), 1886. 

Brooks (T. B.), and Puiapelly (R.), 1872. 

Buckloy (S. B.), 1874, 1876. 

Bart (William A.), 1849. 

Calvin (S.), 1888. 

Cumpboll (H. D.), 1885. 

Campbell (J.), 1863. 

Campbell (J. L.), 1879, 1880, 1884. 

Campbell (J. L. and H. D.), 1884, 1885. 

Campbell (J. L.) and Rutther (W. H.),

1883.

Carpenter (F. R.), 1888. 

Chamberlin (T. C.), 1877, 1883. 

Cliamborliu (T. C.); Irving (R. D.), and.

1885.

Chapman (E. J.), 1877. 

Chester (Frederick D.), 1884.

Clemson (Thomas G.), 1835. 

Comstock (T. B.), 1874,1890. 

Conrad (T. A.), 1839, 1840, 1841, 1842. 

Cook (George II.), 1863, 1868, 1874, 1884,

1885.

Crosby (W. 0.), 1876,1880, 1881, 1889. 

Dames (Wilhelm), 1883. 

Dana (Edw. S.) and Grinnell (G. B.),

1876. 

Dana (James D.), 1863, 1872, 1874, 1877,

1885, 1887, 1890. . 

Dana (J. F. and S. L.), 1818. 

Daniels (Edward), 1859. 

Dawson (George M.), 1384, 1886, 1887. 

Dawson (J. W.), 1850, 1855, 1860, 1862,

1867,1868, 1873, 1878, 1883, 1888. 

D'lnvilliers (E.), 1883. 

De la Beche (Henry), 1832. 

Desor(E.), 1851. 

Devine(T.), 1863. 

Dewey (Chester), 1819, 1820, 1824. 

Dodge (W. W.), 1875. 

Dnttou (Clarence E.), 1881. 

D wight (William B.), 1886, 1887, 1889. 

Eaton (Amos), 1818,1820,1822,1824,1828,

1830,1832, 1839. 

ElliotUJohnB.), 1883. 

Ells(R. W.), 1887, 1889. 

Ells (.R. W.); Bailey (L. W.), Matthew

(G. P.), and, 1880. 

Emrnons (Ebeuezer), 1837, 1838, 1839,

1840, 1841, 1842, 1844, 1847, 1856. 

Emmous (S. P.), 1886. 

Emnions (S. P.); Hague (Arnold), and

1877.

Endlich (F. M.), 1878, 1879. 

Engoluiann (H.), 1857. 

Etheridge (R., jr.), 1883, 1890. 

Ferrier(W. F.), 1883. 

Fitch (Asa), 1850. 

Fletcher (Hugh), 1877, 1878. 

Foerste (A. F.); Shaler (N. S.), and, 1888. 

Foerste (Aug. F.), 1889. 

Fontaine (William M.), 1875, 1883.

19
20 THE CAMBRIAN. [BULL. 81.

Ford (S. W.), 1871, 1872, 1873, 1875, 1876,

1877, 1878,1880,1881, 1884, 1886. 

Foster (J. W.), 1849. 

Foster (J. W.) and Whitney (J. D.),

1849, 1850, 1851. 

Frazer (Persifor, jr.), 1878, 1879, 1880,

1882, 1883, 1886.

Geiger (H. R.) and Keith (Arthur), 1891. 

Geikie (Archibald), 1882. 

Gesner (Abraham), 1836,1841,1843,1845,

1849.

Gilbert (G. K.), 1874, 1875, 1890. 

Grinnell (G. B.); Dana (Ewd.S.), and,

1876.

Green (Jacob), 1834. 

Hague (Arnold), 1881, 1882. 

Hague (Arnold) and Ernmons (S. F.), 1877. 

Hall (Charles E.), 1881, 1885. (See

Beecher, C. E.)

Hall (James) 1839, 1843, 1844,1845,1847, 

 1851, 1858, 1859, 1860, 1861, 1862, 1863,

1873, 1884, 1886. 

Hall (James) and Whitfleld (R. P.), 1873,

1877.

Hall (James); Logan (W. E.), and, 1866. 

Hartt (C. Fred.), 1865, 1868. 

Harvey (M.); Hatton (Joseph), and, 1883. 

Hatton (Joseph) and Harvey (M.), 1883. 

Hayden (F. V.), 1858, 1859, 1861, 1862,

1863, 1369, 1871, 1873, 1874, 1875, 1885,

1888.

Henderaon (J. T.), 1885. 

Hicks (Henry), 1875. 

Hind (H. Y.), 1869, 1870. 

Hitchcock (C. H.), 1861, 1862,1867,1870,

1873, 1874, 1875, 1877, 1879, 1884, 1885,

1888,1890.

Hitchcock (Edw.), 1832,1841,1859. 

Hough (Franklin B.), 1847,1850, 1851. 

Houghtou (Douglass), 1839, 1840,1841. 

Howell (Edwin E.), 1875. 

Hubbard (Bela), 1849. 

Hunt (T. S.), 1852,1854,1861,1868,1870,

1871,1875,1876,1878,1879,1883, 1886. 

Hyatt (Alpheus), 1885. 

Irving (Roland D.), 1872,1874,1875, 1877,

1880,1883,1885,1888. 

Irving (R. D.) and Chamberlin (T. C.),

1885. 

Jackson (C. T.), 1844, 1849, 1851, 1856,

1859; 1861.

Jamea (Edwin), 1821,1822. 

Jenney (W. P.), 1874. 

Johnston (J. F. W.), 1850. 

Jukes (J. Beete), 1843,1862.

Kayser (Emanuel), 1876.

Kerr(W.C-), 1869, 1875.

Killebrew(J. B.), 1874.

King (Clarence), 1876,1878.

King (H.), 1851.

King (William), 16-89.

Kloos(J. H.), 1882.

Lane (Alfred C.), 1889.

Lapham (I. A.), 1851, 1855, 1869.

Lapworth (Charles), 1881.

Lea (Isaac), 1858.

Lesley (J. P.), 1853,1873,1883,1885.

Lewis (H. Carvill), 1883.

Little (George), 1876.

Lloyd (T.G.B.), 1876.

Logau (W. E.), 1845,1847,1849,1850,1851,

1852, 1854, 1855, i860, 1861, 1863, 1865,

1866.

Logan (W. E.) and Hall (James), 1866. 

Low (A.P.), 1884,1886. 

Lydekker (R.); Nicholson (H. A.), and,

1889.

Lyell (Charles), 1845. 

Lyman(B. S.), 1867. 

MoConnell (R, G.), 1887, 1889. 

McCreath (Andrew), 1884. 

McCutchen(A.R.), 1884. 

McGee (W J), 1890. 

Macfarlane (Thomas), 1867. 

Maclure (William), 1809,1817. 

Marcon (Jules),1850,1861,1862,1880,1885,

1888. 

Marcou (Jules); Barrande (Joachim) and,

I860.

Marr(J.E.), 1880,1883. 

Marsh (O.C.), 1869. 

Mar vine (A. R.), 1875. 

Mather (William W.), 1841,1843. 

Matthew (G. F.), 1863, 1865, 1878, 1883,

1884, 1885, 1880, 1887, 1888. 1889, 1890,

1891. ' Matthew (G. F.) and Bailey (L. W.),1869. 

Matthew (G. F.); Bailey (L. W.), and,

1872. 

Matthew (G. F), and Ells (R. W.); Bailey

(L. W.), and, 1880. 

Meads (A.D.), 1889. 

Meek (F. B.), 1868,1870, 1871,1872, 1873,

1877.

Meek (F.B.) and Hayden (F.V.), 1858, 

c 1859,1861,1864. 

Milne (John) and Murray (Alexander),

1877. 

Murchison (R. L); Sedgwick (Adam),

and, 1835.
WALCOTT.] LITERATURE. 21

Murray (Alexander); Milne (John), and,

1877. 

Murray (Alexander), 1852,1854,1866,1868,

1870, 1871,1873,1881. 

Nason (FrankL.), 1891. 

Nevvberry (J. S.), 1861,1873,1874. 

Newton (Henry), 1880. 

Nicholson (H. A.) and Lydekker (R.),

1889. 

Norwood (J.C.), 1852. 

Ordway (Albert), 1861. 

Owen (David Dale), 1843,1848,1851,1852. 

Owen (Richard), 1852,1862. 

Peale (A. C.), 1874,1876,1879,1890. 

Percival (James G.), 1856. 

Perkins (George H.), 1885. 

Perry (John P.), 1867/1868. 

Powell (J. W.), 1875,1876. 

Prime (Frederick, jr.), 1878, 1883. 

Front (H. A.), 1851.

Purnpelly (R.); Brooks (T. B.), and, 1872. 

Ratinesque (C. S.), 1818. 

Rand (T.D.), 1889. 

Richardson (James), 1870. 

' Richthofen (F. F. von), 1882. 

Robb (James), 1850. 

Roemer (Ferdinand), 1849,1852. 

Rogers (Henry D.),1838,1839, 1840,1841,

1844, 1846,1857,1858. 

Rogers (Henry D. and W. B.), 1842. 

Rogers (William B.), 1838, 1839, 1844,

1856,1861,1875,1879,1884. 

Rominger (C.), 1873,1887. 

Ruffiier ( W. H.); Campbell (J. L.), and

1883.

St. John (Orestes), 1879, 1883. 

Safford (J. M.), 1856,1869,1879. 

Salter(J.W.), 1859.

Salter (J. W.) and Aveline (W. T.), 1853. 

Schoolcraft (H. R.), 1855. 

Sears (John H.), 1890. 

Sedgwick (Adam), 1838, 1852, 18T3. 

Sedgwick (Adam) and Murchison(R. L),

1835.

fielwyn (A. R. C.), 1872,1879,1883. 

Shaler (N. S.), 1869,1888, 1889. 

Shaler (N. S.) and Foerste (A. F.),1888. 

Shaler (N. S.) and Williams (H. S.), 1891. 

Shumard (B.F.), 1852,1859,1861,1862.

Smith (E.A.), 1875, 1876,1878,1883,1884.

Smock (John C.), 1886.

Sowter (T. W. E.); Ami (H.), and, 1887.

Steele (John H.), 1823,1825.

Stevenson (John J.), 1887.

Strong (Moses), 1877,1880,1882.

Swallow (G. C.), 1855.1871.

Sweet (E.T.), 1876,1880.

Thompson (Zadock), 1853.

Todd(James E.), 1882.

Troost (Gerard), 1838,1840,1841.

Tnomey (M.),1858.

Tyson (Philip T.), 1860.

Upham (Warren), 1884,1885,1888.

Vanuxera (Lardner), 1840,1842.

Vernenil (Ed. de), 1847.

Wadsworth (M. E.), 1880,1882,1884.

Wadsworth (M. E.); Whitney (J. D.),

and, 1884. 

Walcott (Charles D.), 1879, 1880, 1883,

1884,1885,1886,1887,1888,1889,1890. 

Webster (J. W.), 1824. 

White (C. A.), 1870,1874,1875,1876, 1879,

1880.

White (George), 1849. 

Whiteaves(J.F.), 1878. 

Whitfield (R. P.), 1876, 1877, 1878, 1880,

1882, 1884.

Whitfield (R. P.); Hall (James), and, 

. 1873, 1877.

Whitney (J. D.),1855,1858,1862,1872,1883. 

Whitnoy (J. D.) and Wadsworth (M. E.),

1884. 

Wbitney (J. D.); Foster (J. W.), and,

1849,1850, 1851.

Whittlesey (Charles), 1851, 1863. 

Williams (H.S.), 1888. 

Winchell (Alexander), 1861, 1864. 

Winchell (N.H.), 1873, 1874, 1876, 1878,

1880, 1882, 1883, 1884, 1885, 1886, 1888,

1889.

Winchell (N. H., and H. V.), 1890. 

Win wood (H.H.), 1885. 

Wolff (J.E.), 1891. 

Woodward (Henry), 1884. 

Woodward (J.), 1723. 

Wooster (L.C.), 1878,1882, 1884. 

Young (A. A.), 1882.
22 THE CAMBRIAN. [BULL. 81.

LIST OF PAPERS BY DATES.

1723.

WOODWARD, Dr. J. An essay toward a Natural History of the Earth and Terrestrial 

Bodies. London, 3d edition, 1723. . .

1809.

MACLUBE, WILLIAM. Observations on the Geology of the United States Explanatory 

of a Geological Map. Am. Phil. Soc. Trails., vol. 6, 1809, pp. 411-428, map.

1817.

MACLURE, WILLIAM. Observations on the Geology of the United States; with remarks on the probable effects that may be produced by the decomposition of 

the different classes of roots on the nature and fertility of soils. With a map 

and two plates. Am. Phil. Soc. Trans., new series, vol. 1, 1817, pp. 1-91.

1818.

DANA, J. F., and S. L. DANA. Outlines of the Mineralogy and Geology of Boston 

and its vicinity, with a geological map. Am. Acad. Arts and Sciences, Memoirs, vol. 4, 1818, pp. 129-223.

EATON, AMOS. An Index to the Geology of the Northern States, with a transverse 

section from Catskill Mountain to the Atlantic. Leicester, 1818, pp. 52.

R(AFINESQUE) C. S. Observations on the Geology of the United States of America, 

by William Maclure; a notice. Am. Monthly Magazine, vol. 3, 1818, pp. 

41-44.

1819.

DEWEY, CHESTER. Sketch of the Mineralogy and Geology of the Vicinity of Williams' College, Williainstown, Mass. (With a map.) Am. Jour. Sci., vol. 1. 

1819, pp. 337-346.

1820.

DEWEY, CHESTER. Geological section from Taconick Range, in Williamstown, to 

the city of Troy, on the Hudson. Am. Jour. Sci., vol. 2, 1820, pp. 246-248.

EATON, AMOS. An Index to the Geology of the Northern States. 2d Ed., Troy, 

N. Y., 1820, pp. 286.

1821.

JAMES, EDWIN. Remarks on the sandstone and floetz formations of the western part 

of the valley of the Mississippi. Am. Phil. Soc. Trans., new series, vol. 2, 

1821, pp. 191-215.

1822.

EATON, AMOS. A geological and agricultural survey of Rensselaer County, New York, 

with a geological profile, from Onondaga to Massachusetts. Albany, 1822, 

pp. 70, plate. Memoirs of the Board of Agriculture of the State of New 

York, 1823, vol. 2, pp. 3-43.

JAMES, EDWIN. Geological sketches of the Mississippi Valley. Phila. Acad. Sci., 

Jour., vol. 2, 1822, pp. 326-329.
WAMJOTT.] LITERATURE. 23

1823.

STEELE, JOHN H. A report of the geological structure of the county of Saratoga. 

Memoirs of the Board of Agriculture of the State of New York, vol. 2, 1823, 

pp. 44-84, 155-161.

1824.

BIGSBY, JOHN J. A list of mineral and organic remains occurring in the Canadas.

Am. Jour. Sci., vol. 8, 1824, pp. 60-88. 

DEWKY, CHESTER. A sketch of the geology and mineralogy of the western part of

Massachusetts, and a small part of the adjoining States. Am. Jonr. Sci.,

vol. 8, 1824, pp. 1-60. 

EATON, AMOS. A geological and agricultural survey of the district adjoining the

Erie Canal. Albany, 1824, pp. 163, plate. 

WEBSTER, J. W. Remarks on the geology of Boston and its vicinity. Boston Jour.

Phil, and Arts, vol. 2, 1824, pp. 277-292.

1825.

BiasBY, J. J. Notes on the geography and geology of Lake Superior. Quar. Jour.

Lit., Sci. and Arts (of the Royal lust, of Gt. Britain,) vol. 18, 1825, pp. 1-34,

228-269, map. 

STEELB, JOHN H. A description of the Oolitic Formation lately discovered in the

county of Saratoga, and State of New York. Am. Jour. Sci., vol. 9,1825, pp.

16-19."

1827.

BIGSBY, J. J. On the geology of Quebec audits vicinity. Geol. Soc. London, Proc., 

vol. 1. 1827, pp. 37,38.

1828.

EATON, AMOS. Geological nomenclature, exhibited in a synopsis of North American 

rocks and detritus. Am. Jour. Sci., vol. 14, 1828, oppo. p. 144, pp. 145-159; 

359-368. 

 Annunciation of the second part of Prof. A. Baton's report of the geological 

survey on the Erie Canal. Am. Jour. Sci., vol. 13, 1828, pp. 383-385.

1829.

BAKEWELL, ROBERT. Introduction to Geology, 1st American Edition, New Haven,

1829. 

BAYITIELD, H. W. Outlines of the geology of Lake Superior. Quebec Lit. and Hist.

Soc. Traus., vol. 1, 1829, pp. 1-43.

1830.

EATON, AMOS. Geological text-book, prepared for popular lectures on North American geology; with applications to agriculture and the arts. Albany, 1830, 

pp. 64, pis. and map.

1832.

DE LA BECHE, HENRY. Geological Manual, Philadelphia, 1832.

EATON, AMOS. Geological text-book for aiding the study of North American Geology; being a systematic arrangement of facts collected by the author and 

his pupils under tbe patronage of the Hon. Stephen Van Rensselaer. Second 

edition. 5 plates. Albany, 1832.

 Geological equivalents. Am. Jour. Sci., vol. 21,1832, pp. 132-138.

 Four cardinal points in stratigraphies! geology established by organic remains

Am. Jonr. Sci., vol. 21,1832, pp. 199-200. 

HITCHCOCK, Envv. Report on the geology of Massachusetts; examined under the

direction of tbe government of that State during the years 1830 and 1831.

Am. Jour. Sci., vol. 22,1832, pp. 1-70, with map.
24 THE CAMBRIAN. [BULL. 81

1834.

GREEN, JACOB. Descriptions of some new North American trilobites. Am. Jour. Sci., 

vol. 25,1834, pp. 334-337.

1835.

CLEMSON, THOMAS G. Notice of a geological examination of the country between 

Fredericksburg and Winchester, in Virginia, including the gold region. 

Geol. Soc. Pennsylvania, .Trans., vol. 1, 1835, pp. 298-313. (Colored map of 

sections.)

SEDGWICK, ADAM, and R. I. MUKCHISON. On the Silurian and Cambrian systems, 

exhibiting the order in which the older sedimentary strata succeed each 

other in England and Wales. Brit. Assoc. Report for 1835, part 2, pp. 59-61.

1836.

GESNER, ABRAHAM. Remarks on the geology and mineralogy of Nova Scotia. Halifax, N. S., 1836, pp. 272.

1837.

EMMONS, EBENEZER. First annual report of the second geological district of New 

York. First annual report of the geological survey of New York, Albany,

1837. pp. 97-150; map.

1838.

EMMONS, EBENEZER. Report of the geologist of the second geological district of New 

York. Second annual report of the geological survey of New York, Albany,

1838. pp. 185-250; pi. 4, map.

ROGERS, HENRY D. Second annual report on the geological exploration of the State 

of Pennsylvania. Harrisburg, 1838, pp. 93, plate.

ROGERS, WILLIAM B. Second report of the progress of the geological survey of the 

State of Virginia, for the year 1837. Richmond, 1838, pp. 24. (This report 

occupies pp. 147-188 in the reprint " Geology of the Virginias," New York, 

1884.")

SEDGWICK, ADAM. A synopsis of the English series of stratified rocks inferior to the 

old red Sandstone, with an attempt to determine the successive natural 

groups and formations. Geol. Soc. London, Proc. vol. 2, 1838, pp. 675-C85 

(read May 23, 1838).

TROOST, GERARD. Fourth report of the geologist of the State of Tennessee. Nashville, 1838. Map, pp. 628-652.

1839.

CONRAD, T. A. Notes on American Geology. Am. Jour. Sci., vol. 35,1839, pp. 237-251. 

 Second annual report on the paleontological department of the survey. Third

annual report of the geolouical survey of New York, Albany, 1839, pp. 57-6(5. 

EATON, AMOS. Cherty Limerock, or Corniferous Limerock, proposed as the line of

reference for State geologists of New York and Pennsylvania. Am. Jour.

Sci., vol. 36, 1839, pp. 61-71, 198. 

EMMONS, EBENEZER. Third annual report of the second geological district. Third

annual report of the geological survey of New York, Albany, 1839, pp. 201-239. 

HALL JAMES. Third annual report of the fourth geological district of New York.

Third annual report of the geological survey of New York, Albany, 1839,

pp. 287-339. 

HOUGHTON, DOUGLASS. [Peninsula District.] Second annual report State geologist

of Michigan, Detroit, 1839, pp. 4-39. 

ROGERS, HENRY D. Third annual report on the geological survey of the State of

Pennsylvania. Harrisburg, 1839, pp. 119. 

ROGERS, WILLIAM B. Report of the progress of the geological survey of Virginia,

for 1838 (Richmond, 1839), pp. 32. (This report occupies pp. 189-244 of the

reprint "Geology of the Virginias," New York, 1884.)
WAWOTT.J LITERATURE. 25

1840.

CONRAD, T. A. On the Silurian system, with a table of the strata and characteristic

fossils. Am. Jour. Sci., vol. 38, 1840, pp. 80-93; 

EMMONS, EBENEZER. Fourth annual report of the survey of the second geological

district of New York. Fourth annnalreport of the geological survey of New

York, Albany, 1840, pp. 259-353. 

HOUGHTON, DOUGLASS. Third Ann. Rep. State Geol. of Michigan. House Reps.

Document No. 8. 1840, pp. 33. 

ROGERS, HENRY D. Description of the geology of the State of New Jersey, being a

final report. Philadelphia, 1840, with plate and map. pp. 301.

 Fourth annual report on the geological survey of the State of Pennsylvania.

Harrisburg, 1840, pp. 252. 

TROOST, GERARD. Fifth geological report on the State of Tennessee. Nashville,

1840. pp. 44, 3 maps.

VANUXEM, LARDNKR. Fourth annual report of the geological survey of the third 

district. Fourth report of the geological survey of New York, Albany, 1840, 

pp. 355-383.

1841.

CONRAD, T. A. Fifth annual report on the paleontology of New York. Fifth annual 

report of the geological survey of New York, Albany, 1841, pp. 25-57.

EMMONS, EBENEZER. Geology of the Montmorenci. American Magazine, ATO!. 1,1841, 

pp. 146-150.

GESNER, ABRAHAM. Third report on the geological survey of the Province of New 

Brunswick. St. John, 1841, pp. 88.

HITCHCOCK, EDWARD. Final report on the geology of Massachusetts, 2 vols., Amherst,

1841. vol. 1, pp. xn, 299; vol. 2, pp. 300-831; 55 pis.

HOUGHTON, DOUGLASS. Report [on the Northern or Upper Peninsula], Geol. Survey 

Michigan, 4th Ann. Rep. State geologist, 1841, pp. 4-89.

MATHER, W. W. Fifth annual report on the geological survey of the first geological 

district. Fifth annual report of the geological survey of New York, Albany, 

1841, pp. 63-112.

ROGERS, H. D. Some observations on the geological structure of Berkshire, Massachusetts, and neighboring parts of New York. Am. Phil. Soc., Proc., vol. 2, 

1841, pp. 3,4.

 Fifth annual report on the geological exploration of Pennsylvania. Harrisburg, 1841, pp. 156 and plate.

TROOST, GERARD. Sixth annual report of the geological survey of Tennessee by the 

State geologist. Nashville, 1841, pp. 48.

1842.

CONRAD, T. A. Observations on the Silurian and Devonian systems of the United 

States, with descriptions of new organic remains. Phila. Acad. Sci., Jour., 

vol. 8, 1842, pp. 228-235.

EMMONS, EBENEZER. Geology of Now York, part 2, comprising the survey of the 

second geological (northern) district, 1842, pp. 438, pis. 17.

 Topography, geology, and mineral resources of the State of New York. 

Gazetteer of the State of New York, by J. Disturnell, Albany, 1842, pp. 5-25.

ROGERS, II. D., and W. B. ROGERS. On the physical structure of the Appalachian 

Chain, as exemplifying the laws which have regulated the elevation of great 

mountain chains generally. Brit. Assoc. Rept., vol. 12, Trans. Sec., pp. 40-42; 

Am. Jour. Sci., vol. 44,1842, pp. 359-362: Trans. Am. Assoc. Geol. and Nat., 

184:?, pp. 474-531.

VANUXEM, LAUDNKR. Geology of New York. Geology of the Third (central) Geological District. Albany, 1842, pp. 307.

GESNER. ABRAHAM.. Report on the Geological Survey of the Province of New Brunswick, with a Topographical Account of the Public Lands and Districts Explored in 1842. St. John, 1843, pp. 88.

 Memoir of the Geology of Nova Scotia, with a map. Geol. Soc. London, Proc., 

Vol. 4, 1843, pp. 186-190.

HALL, JAMKS. Geology of New York. Geology of the Fourth (western) Geological 

District. Albany, 1843, pp. xxvii, 686, 19 pis. and map.
26 THE CAMBRIAN. [BULL. 81.

HALL, JAMES. Geological map of tlie Middle and Western States. Geol. of New 

York. Rep.,on the Fourth Geological District, Albany, 1843.

 Notes Explanatory of a section from Cleveland, Ohio, to the Mississippi 

River, in a Southwest Direction; with remarks upon the Identity of the 

Western Formations with those of New York. Assoc. Am. Geol. Trans., 1843, 

pp. 267-293.

JUKES, J. B. General report of the Geological Survey of Newfoundland in 1839 and 

1840, London, 1843, pp. 160, 2 pis.

MATTIKR, WILLIAM W. Geology of New York; Geology of the First (southeastern) 

District. Albany, 1843, pp. xxxvii, 655, 46 pis.

OWEN, DAVID DALE. On the Geology of the Western States. Ain. Jour. Sci., vol.' 

45, 1843, pp. 151, 152, 163-165.

1844.

EMMONS, E. The Taconic System; based on Observations in New York, Massachusetts, Vermont, and Rhode Island. Albany, 1844, pp. vii, 67, 6 pis.

HALL, JAMES. Geological Survey of New York; its Influence on the Productive Pursuits of the Community. New York State Agr. Soc. Trans. for 1843, 1844, pp. 

241-277.

JACKSON, C. T. Final Report on the Geology and Mineralogy of the State of New 

Hampshire, with Contributions towards the Improvement of Agriculture and 

Metallurgy. Concord, 1844, pp. viii, 376.

ROGERS, HENRY D. On American Geology and Present Condition of Geological Research in the United States. Am. Jour. Sci., vol. 47,1844, pp. 137-161,247-278.

ROGERS, W. B. A System of Classification and Nomenclature of the Paleozoic Rocks 

of United States, with an Account of their Distribution more Particularly in 

the Appalachian Mountain Chain. Am. Jour. Sci., vol. 47,1844, pp. Ill, 112.

1845.

ADAMS, C. B. First Annual Report on the Geology of Vermont. Burlington, 1845,

pp. 92. 

BAYFIELD, H. W. On the Junction of the Transition and Primary Rocks of Canada

and Labrador. Quart. Jour. Geol, Soc., London, vol. 1, 1845, pp. 450-459. 

GESNER, A. Geological Map of Nova Scotia. (Accompanying papers by J. W. Dawson and Richard Brown.) Quart. Jour. Geol. Soc., London, vol. 1, 1845,

oppo. p. 23. 

HALL, JAMES. Nature of the Strata and Geographical Distribution of the Organic

Remains in the Older Formations of the United States. Boston Jour. Nat.

Hist., vol. 5, 1845, pp. 1-20. 

LOGAN, W. E. (Account of General Structure of an Extended Area in North

America.) Geol. Survey Canada, Report of Progress for 1843. 1845. 

LYELL, CHAS. Travels in North America. New York, 1845, vol. 1, pp. 251, vol. 2,

pp. 231.

1846.

ADAMS, C. B. Second Annual Report on the Geology of the State of Vermont. Burlington, 1846, pp. 267.

BARRANDE, J. Notice Preliminaire sur le Syst&me Silurien et lea Trilobites de Bohthne, Leipsig, 1846.

ROGERS, H. D. On the Mineralogy and Geology of the South Shore of Lake Superior. Boston Soc. Nat Hist., Proc., vol. 2, 1846, pp. 124, 125.

1847.

ADAMS, C. B. Third Annual Report on the Geology of the State of Vermont. Burlington, 1847, pp. 32. (See foot-note on page 31).

 On the Taconic System. Am. Jour. Agri. and Sci., vol. 6, 1847, p. 260 (corrected pagination).

EMMONS, E. [On the Taconic system.] Am. Jour. Agri. and Sci., vol. 6, 1847, p. 

260 (corrected pagination).

 Agriculture of New York, vol. 1. Albany (1846), 1847, pp. 371, pis. 21, map.

HALL, JAMES. Paleontology of New York, vol. 1, Containing Descriptions of the Organic Remains of the Lower Division of the New York System. Albany, 

1847, pp. xxiii, 338, pis.

 Letter on Certain Fossils in the Red Sandrock of Highgate. Thifd Annual 

Report on the Geology of the State of Vermont. Burlington, 1847, p. 31.
WAT.COTT] LITERATURE. 27

HOUOII, FRANKLIN B. Observations on the Geology of Lewis County. Now York. 

Am. Jour. Agri. and Sci., vol. 5, 1847, pp. 267-274, 314-327.

LOGAN, W. E. Report ou Sequence ami Distribution of tlio Formations [on the Ottawa], Geol. Surv. Canada, Rep. Progress for 1845-6. Montreal, 1847, pp. 

40-75.

VERNEUIL, ED..DE. Note sur le parallelisme des roches des ddpAts paldozoiques do 

l'Ame"rique Septentrionale avec ceux do 1'Europe, suivi d'uii tableau des 

especes fossiles communes anx denx continents, avec 1'indication tlos 6tagos 

oh elles so rencontrent, et termin6 par un examen critique de chacuno de cos 

espcces. Soc. griol. France, Bull., 2° se"r., vol. 4, 1847, pp. 646-70D. Translated with annotations by Prof. James Hall, Am. Jour. Sci., 2d ser.,vol. 5, 

1848, pp. 176-183, 359-370; vol. 7, 1849, pp. 45-51, 218-231.

1848.

ADAMS, C. B. On the Tacouic Rocks. Am. Jour. Sci., 2d ser., vol. 5, 1848, pp.

108-110. 

OWEN, D. D. (Letter ou Geology of Wisconsin Territory.) Soc. ge"ol. France. Bull.

2«se"r., vol. 5, 1848, pp. 294-296.

 Report of a Geological Reconnoissance of the Chippewa Land District of Wisconsin ; and Incidentally of a Part of Iowa and of the Minnesota Territory. 

Letter of the Secretary of the Treasury Communicating a Report of a Geological Reconuoissance of the Chippewa Land District of Wisconsin (etc), by 

D. D. Owen, Thirtieth Congress, lirst session. Senate Ex. Doc. No. 57. 1848. 

pp. 3-72, map, plates.

1849.

BURT, WILLIAM M. Topography and Geology of the Survey, with reference to mines 

and minerals, of a District of Township Lines South of Lake Superior in 1845. 

Message President United States, Thirty-first Congress, first session, H. R. 

Ex. Doc. No. 5, part 3, 1849, pp. 811-333.

FOSTKR, J. W. Notes on the Geology and Topography of Portions of the Country 

Adjacent to Lakes Superior and Michigan, in the Chippewa Land District. 

Message from President of United States to Congress, Thirty-first Congress, 

first session, H. R. Ex. Doc. No. 5, part 3, 1849, pp. 773-785.

FOSTER, J. W., and J. D. WIIITNKY. Synopsis of the Explorations of the Geological 

Corps in the Lake Superior Land District in the Northern Peninsula of Michigan. Message from the President of United States to Congress, Thirtyfirst Congress, first session, H. R. Ex. Doc. No. 5, part 3, 1849, pp. 605-025, 

3 maps.

GESNER, ABRAHAM. The Industrial Resources of Nova Scotia. Halifax, N. S., 1849, 

pp. 341, and Appendix, p. 15.

IIuBBARii, BBLA. General Observations upon the Geology and Topography of the 

District South of Lake Superior, Subdivided in 1845, under Houghton. Message from President of United States, Thirty-first Congress, first session, H. 

R. Ex. Doc. No. 5, part 3, 1849, pp. 833-842.

JACKSON, C. T. Message of President of United States to Congress. Thirty-first 

Congress, first session, H. R. Ex. Doc. No. 5, part 3,1849, pp. 371-502.

LOGAN, W. E. Canadian Geological Survey, Report Progress for 1847-M8, 1849.

ROEMEK, FERD. Texas. Mit besonderer Riichsicht auf deutsche Auswaudt-.rung-nnd 

die physischon Verbiiltnisse des Landes nach eigener Beobachtung geschildert. Bonn, 1849, pp. 464, map.

WHITE, GEORGE. Statistics of the State of Georgia. Savannah, 1849, pp. 624 and 

77, map.

1850.

DAWSON, J. W. On the Metamorphic and Metalliferous Rocks of Eastern Nova Scotia. Quart. Jour. Geol. Soc., London, vol. 6, 1850, pp. 347-364.

FITCH, ASA, M. D. A Historical, Topographical, and Agricultural Survey of the 

County of Washington. Traus. N. Y. State Agric. Soc. for le!49, 1850, pp. 

753-944.

FOSTER, J. W., and J. D. WHITNEY. [Apercu de 1' ensemble des terrains Silurians 

du lac Superieur.] Soc. ge"ol. France, Bull.,2e s<5r., vol. 8, 1850, pp. 89-100.

 Report on the Geology and Topography of a Portion of the Lake Superior 

Ljiucl District in the State of Michigan. Part I. Washington, 1850. Stratitied and Sedimentary Rocks. Chapter 4, pp. 99-122.
28 THE CAMBRIAN,

HOUGH, FRANKLIN B. Catalogue, of Mineralogical and Geological Specimens Received from F. B. Hough. Third Annual Rep. of Regts. Univ. State Cab. 

Nat. Hist. 1850, pp. 31-33.

 On the Cylindrical Structure Observed in Potsdam Sandstone. Am. Assoc.

Proc., vol. 4, 1850, pp. 352-354. 

JOHNSTON, J. F. W. Report; on the Agricultural Capabilities of the Province of New

Brunswick. Fredericton, 1850, pp. 262. 

LOGAN, W. E. Report on Bay St. Paul and Murray Bay. Geol. Sur. Canada, Rept.

Progress for 1849-'50. Toronto, 1850, pp. 7-31.

 Report on Rocks on South Side of the St. Lawrence. Geol. Sur. Canada,

Rept. Progress for 1849-'50. Toronto, 1850, pp. 31-72. 

MARCOU, JULES. Re"ponse a la lettre de MM. Foster et Whitney sur le lac Sup6rienr.

Soc. g<5ol., France, Bull. 2e se"r., vol. 8, 1850, pp. 101-105. 

ROBB, JAMES. (Letter on the Geological Structure of New Brunswick.) Report on

the Agricultural Capabilities of the Province of New Brunswick, by J. F. W.

Johnstou, Fredericton, 1850, pp. 12, 13.

1851.

DESOR, E. [Potsdam Sandstone on the River St. Croix. ] Boston Soc. Nat. Hist.

Proc., vol. 3, 1851, p. 202. 

FOSTER, J. W., and J. D. WHITNEY. On the Age of the Sandstone of Lake Superior,

with a Description of the Phenomena of Igneous Rocks. Am. Assoc. Proc.,

vol. 5, 1851, pp. 22-39.

 Lower Silurian System. Potsdam and Calciferous Sandstones. Rept. on 

Geol. of Lake Superior Land District, part 2, 1851, pp. 110-139.

HALL, JAMES. [Geological Investigations on Drununond's Island and the North 

Shores of Lakes Huron and Michigan, etc.] Am. Acad. Proc., vol. 2, 1851, pp. 

253, 254.

 Description of New or Rare Species of Fossils from the Palteozoic Series. Kept, 

on the Geology of the Lake Superior Land District, by Foster aud Whitney, 

part 2, 1851, pp. 203-231.

 Parallelism of the Palaeozoic Deposits of the United States and Europe. 

Rept. on the Geology of the Lake Superior Land District, by Foster and 

Whitney, part 2, 1851, pp. 285-318.

JACKSON, C. T. [Some Observations on the Age of the Sandstones of the United 

States.] Boston Soc. Nat. Hist., Proc., vol. 3, 1851, pp. 335, 336, 337-339.

KING, H. Some Remarks on the Geology of the State of Missouri. Am. Assoc. Proc., 

vol. 5, 1851, pp. 182-199.

LAPHAM, I. A. On the geology of the southeastern portion of the State of Wisconsin; being the part not surveyed by the United States geologists. Kept, on 

the geology of the Lake Superior land district by Foster and Whitnev, part 2, 

1851, pp. 167-172.

LOGAN. W. E. On the occurrence of a track and footprints of an animal in the Potsdam sandstone of Lower Canada. Quart. Jour. Geol. Soc., London, vol. 7, 

1851, pp. 247-257.

OWEN, D. D. On the paleontology of the lowest sandstones of the Northwest. Am. 

Assoc., Proc., vol. 5, 1851, pp. 169-172.

PROUT, H. A. Description of a new Graptolite found in the lower Silurian rocks 

near the Falls of the St. CroixRiver. Am. Jour. Sci., 2d ser.,vol. 11,1851, pp. 

187-191.

WH'ITTLESEY, CHARLES. Remarks upon the section from the Falls of Wolf River, 

through Navariuo to Lake Michigan. Rept. on the geology of the Lake Superior land district, by Foster and Whituey, part 2, 1851, pp. 174-177.

 The dip, bearing, aud thickness of the Silurian groups. Rept. on the geology 

of the Lake Superior land district, by Foster and Whitney, part 2, 1851, pp. 

177-189.

1852.

BARRANDE, J. Systeme de la Boheme, vol. 1, 1852, p. 88.

HUNT, T. S. Remarks on the lithological and paleontological characters of the Potsdam sandstone. Am. Assoc., Proc., vol. 6, 1852, pp. 271-273.

LOGAN, W. E. Report [on country between Riviere du Nord and Beauharnois]. 

Geol. Survey of Canada. 1851-'52, 1852, pp. 5-56.

 On the age of the copper-bearing rocks of Lakes Superior and Huron, etc. British Assoc. Rep. for 1851-'52, Traus. of sections pp. 59-62. Am. Jour. Sci., 

2d ser., vol. 14, 1852, pp. 224-229.

 On the footprints occurring in the Potsdam sandstone of Canada. Quart, 

Jour. Geol. Soc. London, vol. 8,1852, pp. 199-208.
WAI.COIT.] LITERATURE. 29

MURRAY. ALEX. Report [of country lying between rivers Ottawa andSt. Lawrence].

Geol. Survey of Canada for 1851-'52, 1852, pp. 57-91.

NORWOOD, J. C. Description of the geology of middle and western Minnesota, including the country adjacent to the northwest and part of the southwest shore of

Lake Superior. Rep. Geol. Survey of Wis., Iowa, and Minn.. and incidentally

of a portion of Nebraska Territory, by D. D. Owen, Philadelphia, 1852, pp.

215-418. 

OWEN, D. D. Geol. Survey of Iowa, Minnesota, and Wisconsin, and incidentally of

a portion of Nebraska Territory, Philadelphia, 1852, pp. xvii-xxxviii, 39-

206, plates. 

OWEN, RICHARD. Description of the impressions and footprints of the Protichnites

from the Potsdam sandstone of Canada. Quart. Jour. Geol. Soc. London,

vol. 8, 1852, pp. 214-225. 

ROEMER, FERD. Die Kreidebildungen vou. Texas uud ihre organischen Eiuschlusse,

Bonn, 1852, pp. 100. 

SEDGWICK, ADAM. On the classification and nomenclature of the Lower Paleozic rocks

of England and Wales. Quart. Jour. Geol. Soc. London, vol. 8, 1852, pp.

136-168. 

SJIUMARD, B. F. Local details of geologic sections on the St. Peter's, Mississippi,

Wisconsin, Baraboo, Snake, and Kettle Rivers. Report of a geological sur- 

' vey of Wis., Iowa, and Minn., and incidentally of a portion of Nebraska

Territory, by D. D. Owen, Philadelphia, 1852, pp. 475-531, pis.

1853.

BARRANDE, J. [Silur-Fauna im Wisconsin uud im New York.] Neues Jahrbuch filr

Miner., 1853, pp. 335-347. 

 [Silur-Gebilde irn Texas uud am Oberen-See.] Nones Jahrbuch fiir Miner.,

1853. pp. 446,447.

BIGSBY, J. J. On the geology of Quebec and its environs. Quart. Jour. Geol. Soc., 

London, vol. 9, 1853, pp. 82-101.

LESLEY, J. P. [Report on Hiwassee copper region.] First annual report of the 

board of directors of the Hiwasseo Mining Company, made May 11, 1853. 

Now York, 1853* pp. 12-19.

SALTKR, J. W., and W. T. AVELINK. On the " Caradoc sandstone " of Shropshire. 

Quart. Jour. Geol. Soc. London, vol. 9, 1853, pp. 62-73.

THOMPSON, ZADOCK. Geology of Vermont. Natural History of Vermont. Burlington, 1853, Appendix, pp. 40-58.

1854.

HUNT, T. S. On some of the crystalline limestones of North America. Am. Jour. 

Sci.. 2d ser., vol. 18, 1854, pp. IU3-200.

LOGAN, W. E. [Exploration on the north side of the St. Lawrence, between Montreal and Cape Tourmente.] Geol. Surv. Canada, Rep. progress for 1852-'53,

1854. pp. 5-74.

MURRAY, ALEX. [Exploration between Kingston and Lake Simcoo.J Geol. Surv. 

Can., Rep. progress for 1852-'53, 1854, pp. 75-152.

1855.

DAWSON, J. W. Acadian Geology, first edition. Edinburgh, 1855, pp. 384.

LAM-IAM, I. A. Geological map of Wisconsin. Milwaukee, 1855.

LOGAN, W. E. [Sur la formation silurique des environs do Qu6bec.] Soc. g6ol. 

France, Bull., 2" ser., vol. 12, 1855, pp. 504-508.

SCHOOLCRAITT, H. R. Observations on the geology and mineralogy of the region embracing the sources of the Mississippi River and the Great Lakebasins during 

the expedition of 1820. SchoOlcraft's Mississippi River, Phila., 1855, pp. 303- 

362. Reprint from report made in 1820.

SWALLOW, G. C. Geology of Missouri. [Silurian system.] Geol. Survey Missouri, 

1st and2d Ann. Repts, part 1, 1855, pp. 107-133.

WHITNEY, J. D. Remarks on some points connected with the geology of the north 

shore of Lake Superior. Am. Asaoc. Proc., vol. 9, 1855, pp. 204-209.

1856.

EMMONS, EBENEZER. American Geology, containing a full statement of the principles of the science, with full illustrations of the characteristic American fossils. Albany, 1856. Vol. 1, pt. 2.
30 THE CAMBRIAN. [BULL. 81.

 Geological report of the midland counties of North Carolina. New York and 

Raleigh, 1856, pp. XX, 347, map and 12 pis.

JACKSON, C. T. [On the Braintree argillite and its trilobites.] Boston Soc. Nat. 

Hist., Proc., vol. 6,1856, pp. 42-44.

PKRCIVAL, JAMES G. Annual report of the geological survey of the State of Wisconsin, Madison, 1856, pp. 111.

ROGERS, W. B. Proofs of the Protozoic age of some of the altered rocks of eastern 

Massachusetts from fossils recently discovered. Am. Acad., Proc., vol. 3, 

1856, pp. 315-318.

 [On trilobites from Braintree and on the geological relations of the district.] 

Boston Soc. Nat. Hist., Proc., vol. 6, 1856, pp. 27-29, 40,41.

 Discovery of Paleozoic fossils in eastern Massachusetts. Am. Jour. Sci., 2d

ser., vol. 22, 1856, pp. 296-298. 

SAFFORD, J. M. A geological reconnaissance of Tennessee, 1st biennial report,

Nashville, 1856, pp. 154 and map.

1857.

ENGELMANN, H. Report of a' geological exploration from Fort Leaven worth to Bryan's Pass, made in connection with the survey for a road from Fort Riley to 

Bridger's Pass, under Bryan. Rept. Sec. of War, Appendix H, 1857, pp. 

489-517.

ROGERS, H. D. On the correlation of the North American and British Paleozoic 

strata. British Assoc. Adv. Sci., vol. 26, 1857, Trans. Sec., pp. 175-166.

1858.

BIGSBY, JOHN J. On the Paleozoic basiu of the State of New York. Part i. A 

synoptical view of the mineralogical and fossil characters of the Paleozoic 

strata of the State of New York. Quar. Jour. Geol. Soc., Londou, vol. 14, 

pp. 335-427.

 Part n. Classification of the Paleozoic strata of the State of New York, Ibid.

pp. 427-452.

HALL, JAMES. Geology of Iowa, vol. 1, 1858, pp. 35-146, 473-724. 

HAYDEN, F. V. Explorations under the War Department. Explanations of a second

edition of a geological map of Nebraska and Kansas, based upon information

obtained in an expedition to the Black Hills, under command of Lieut. G. K.

Warren, topographical engineer, U. S. Army. Am. Jour. Sci., 2d ser., vol.

26, 1858, pp. 276-278. 

LEA, ISAAC. [On the trilobite formation at Braintree, Massachusetts.] Phila. Acad.

Sci., Proc., vol. 9, 1858, p. 205. 

MEEK, F. B., and F. V. HAYDEN. Fossils of Nebraska. Letter from F. B. Meek and

P. V. Haydeu. Am. Jour. Sci., 2d ser., vol. 25, 1858, pp. 439-441. 

ROGERS, HKNRY DARWIN. The geology of Pennsylvania. Two vols. Philadelphia,

1858. Vol. 1, pp. 596, and pis; vol. 2, pp. 1046 and 30 pis., and atlas of 2

maps and 2 pie. 

TUOMEY, M. Second biennial report on the geology of Alabama, Montgomery, 1858,

pp. 168 and pi. 

WHITNEY, J. D. Geol. Surv. Iowa, vol. 1, 1858, pp. 259-472.

1859.

BIGSBY, JOHN J. On the Paleozoic basin of the State of Now York. Part in. An inquiry into the sedimentary and other external relations of the Paleozoic fossils of the State of New York. Quar. Jour. Geol. Soc. London, vol. 15, 1859. 

pp. 251-335.

DANIELS, EDWARD. [Notes on geology of Wisconsin and adjacent States.] Boston 

Soc. Nat. Hist.. Proc., vol. 6, 1859, pp. 309, 310.

HALL, JAMES. Remarks upon the trilobites of the shales of the Hudson River group. 

^ Palaeoutology of New York, vol. 3, supplement to vol. 1, 1859, pp. 525-529.

HAYDEN, F. V. Explorations under the War Department. Explanations of a second 

edition of a geological map of Nebraska and Kansas, based upon information 

obtained in an expedition to the Black Hills, under command of Lieut. G. K. 

Warren, topographical engineer, U. S. Army. Phila. Acad. Sci., Proc., vol. 

10, 1859, pp. 139-153.

HITCHCOCK, EDWARD. [Catalogue of State cabinet and notes on metamorpbic rocks. ] 

Sixth annual report of the secretary of Massachusetts Board of Agriculture, 

etc., by Charles L, Flint, Boston, 1§59, pp. iii-lxix.
WAMJOTT.] LITERATURE. 31

JACKSON, C. T. [On a trilobite froiu Braiutree.J Boston Soc. Nat. Hist.,rroc., vol. 

7, 1859, p. 54.

MEEK, F. B., and F. V. HAYDEN. [Some remarks 011 the geology of the Black Hills 

and portions of the surrounding country.] Phila. Acad. Sci., Proc., vol. 10, 

1859, pp. 41-49, map.

SALTER, J. W. On the fossils of the lingula-fiags or " zone primordiale." Quar. 

Jonr. Gcol. Soc., London, vol. 15, 1859, pp. 551-555.

SHUMARD, B. F. Letter touching the late discovery of Lower Silurian rocks, equivalent to the Potsdam sandstone and Caloifbrous sandrock of the New York 

system, in Bur net County, Texas. Trails. Acad. Sci., St. Louis, vol. 1, 1859, 

pp. 672,673.

1860.

BARRANDE, J. Trilobiten der Primordial-Fauna in Massachusetts. Neues Jahrb., f iir

Mirier, I860, pp. 429-431. 

BILLINGS, E. On some new species of fossils from the limestone near Point Levi,

opposite Quebec. Canadian Naturalist, vol. 5, 1860, pp. 301-324.

 [Review of] Acadian Geology, and a Supplementary Chapter thereto. Canadian Naturalist, vol. 5, 1860, pp. 450-455.

BRADLEY, F. H. Description of a New Trilobite from the Potsdam Sandstone. Am. 

Jour. Sci., 2d ser., vol. 30, 1860, pp. 241,242.

DAWSON, J. W. Supplementary Chapter to Acadian Geology, Edinburgh, 1860, pp. 70.

BALL, JAMES. Note upon the trilobites of the shales of the Hudson River group, in 

the town of Georgia, Vt. Thirteenth Aiin. Rep. State Cab. Nat. Hist., 1860, 

pp. 113-119. Report upon the Geology of Vermont, vol. 1, 1861, pp. 367-372.

LOGAN, SIR W. E. On the track of an animal lately found in the Potsdam formation. Canadian Naturalist, vol. 5, 1860, pp. 279-285.

MARCOU, JULES ; JOACHIM BARRANDE and. On the Primordial fauna and the Tacouic 

system; with additional notes by Jules Marcou. Boston Soc. Nat. Hist., 

Proc., vol. 7, 1860, pp. 369-382; Am. Jour. Sci., 2d ser., vol. 31. 1860, pp. 

212-215 ; Canadian Naturalist, vol. 6, 1860, pp. 108-112.

TYSON, PHILIP T. First Report of the State Agricultural Chemist of Maryland. 

Annapolis, 1860, pp. 145 and 20, map.

1861.

BARRANDE, J. Documents anciens et nouveaux sur la faune primordiale et lesysteme

taconique en Ame'rique. Soc. ge"ol. France, Bull., 2e s6r., vol. 18, 1861, pp.

203-321. 

BILLINGS, E. On the Age of the Red Sandstone Formation of Vermont. Am. Jonr.

Sci., 2d ser., vol. 32, 1861, p. 232. 

HALL, JAMES. On the Primordial fauna and Point Levi fossils. Am. Jour. Sci.,2d

ser., vol. 31,1861, pp. 220-226. Canadian Naturalist, vol. 6,1861, pp. 106-120.

 Report of the Superintendent of the Geological Survey [of Wisconsin] Exhibiting the progress of the work. January 1, 1861. Madison, 1861, pp. 52.

 Correction for the 13th Annual Report. Fourteenth Ann. Rep. State Cab. 

Nat. Hist., 1861, p. 110.

HAYDEN, F. V. Sketch of the geology of the country about the headwaters of the 

Missouri and Yellowstone rivers. Am. Jour. Sci., 2d ser., vol. 31, 1861, pp. 

229-245.

HITCHCOCK, C. H. Hypozoic and Paleozoic rocks. Report on the geology of Vermont, descriptive, theoretical, economical, and sceuographical, vol. 1, 1861, 

pp. 257-294. Notes on the Sections, vol. 2, 1861, pp. 595-682.

 [On the Geology of Vermont, chiefly in connection with tlie Taconic system.] 

Boston Soc. Nat. Hist., Proc., vol. 7, 1861, pp. 426,427.

 General Report on the Geology of Maine. Prelim. Rep. on the Natural History and Geology of Maine. Augusta, 1861, pp. 146-328.

HUNT, T. STERRY. On some points in American geology. Am. Jour. Sci., 2d ser., 

vol. 31,1861, pp. 392-414. Canadian Naturalist, vol. 6, 1861, pp. 81-105.

JACKSON, C. T. [On a trilobite from Braintree.] Boston Soc. Nat. Hist., Proc., vol. 

8, 1861, p. 58.

LOGAN, W.E. Remarks on the fauna of the Quebec group of rocks and the Primordial 

zone of Canada. Canadian Naturalist, vol.5,1860, pp. 472-477; vol. 6, 1861, 

pp. 106-120; Am. Jour. Sci., 2d ser., vol. 31,1861, pp. 216-220. Remarques sur 

la faune des rocbes du groupe de QiuSbec et eur la zone primordiale du Canada. Soc. geol., France, Bull., 2e s6r., vol. 18, 1861, pp. 309-914.

MARCOU, JULES. The Taconic ami Lower Silurian rocks of Vermont and Canada. 

Boston Soc. Nat. Hist., Proc., vol. 8, 1861, pp. 239-353.
32 THE CAMBRIAN. . [BULL. 81.

MEEK, F. B., and F. V. HAYDEN. Descriptions of new Lower Siluriau (Primordial) 

Jurassic, Cretaceous, and Tertiary Fossils, collected in Nebraska ; with some 

remarks on the rocks from which they were obtained. Phila. Acad. Sci., 

Proc., vol. 13, 1861, pp. 415-447.

NEWBERRY, J. S. Geological Report. Report upon the Colorado River of the West, 

explored in 1857-'58 by Lieut. J. C. Ives. Part in, 1861, pp. 154.

ORDWAY, ALBERT. On the occurrence of other fossil forms at Braintree, Massachusetts. Boston Soc. Nat. Hist., Proc., vol. 8, 1861, pp. 5,6.

ROGERS, WILLIAM B. [Notes on the geological structure of western Vermont.] Report on the geology of Vermont, vol. 1, 1861, pp. 326,327.

 [On fossiliferous pebbles of Potsdam rocks in Carboniferous conglomerate north 

of Fall River, Massachusetts. ] Boston Soc. Nat. Hist., Proc., vol. 7,1861, pp. 

389-391.

 Remarks on the geology of the neighborhood of St. John, New Brunswick.

Boston Soc. Nat. Hist.. Proc., vol. 7, 1861, p. 176. 

SHUMARD, B. F. [Letter on the Primordial of Texas.] Soc. ge"ol. France, Bull.,

2e se"r. vol. 18, 1861, pp. 218, 219.

 The Primordial zone of Texas, with descriptions of new fossils. Am. Jour.

Sci., 2d ser., vol. 32,1861, pp. 213-221. 

WINCHELL, A. Geology. [General sketch.] Geol. Surv. Michigan, 1st Biennial

Rep. of Prog., Lansing, 1861, pp. 21-141.

1862.

AGASSIZ, Louis. [On the differeace between faunas of zoological and geological 

periods.] Boston Soc.Nat.Hist., Proc., vol.8, 1862, p.58.

BILLINGS, E. On Prof. J. Hall's claim to priority in the determination of the age of 

the Red Sandrock series of Vermont. Am.Jour. Sci.. 2d ser.,vol. 33,1862, pp. 

370-376.

 Further observations on the age of the Red Saudrock formation (Potsdam

Group) of Canada and Vermont. Am. Jour. Sci., 2d ser., vol.33,1862, pp.

100-105. (See note and corrections, same vol., pp. 421,422.) 

DAWSON, J. W. On the flora of the Devonian period in Northeastern America.

Quart. Jour. Geol. Soc., London, vol. 18, 1862, pp. 296-330. 

HALL, JAMKS. Physical geography and general geology. Geol. Survey Wisconsin,

vol. 1, 1862, pp. 1-72, maps.

 On a new crustacean from the Potsdam sandstone. Canadian Naturalist, vol. 

7, 1862, pp. 443-445.

 Supplementary note to the 13th Ann. Rep. State Cab. Nat. Hist., New York. 

Fifteenth Ann. Rep. State Cab. Nat. Hist., New York, 1862, p. 114.

 [Letter on the Primordial of America. 1 Soc. ge"ol. France., Bull., 2e s6r.,vol. 19, 

1862, pp. 725-734.

 On the Potsdam sandstone and Hudson River rocks in Vermont. Am. Jour. 

Sci., 2d. ser., vol. 33, 1862, pp. 106-108.

HAYDEN, F. V. The Primordial sandstone of the Rocky Mountains in the Northwestern Territories of the United States. Am. Jour. Sci., 2d ser., vol. 33, 1K62, 

pp. 68-79. Canadian Journal, new ser., vol. 7, 1862, pp. 149-151.

HITCIICOCK, C. H. Reports on the Geology of Maine. Second Annual report on the 

natural history and Geology of Maine. Augusta, Id62, pp. 223-264, 266-312, 

323-332, 343-352, 377-382, 388-395, 404-405, 422-430, map.

 Fossils of the Potsdam Group in North America. Portland Soc. Nat. Hist., 

Proc. vol. 1, 1862, pp. 87-90.

JUICES, J. BEETE. The Student's Manual of Geology. Second edition, Edinburgh, 

1862, pp. xx, 764.

MAKCOU, JULES. [The slate of Nova Scotia metarnorphic Taconic rock. ] Boston Soc. 

Nat. Hist., Proc., vol. 9,1862, p. 47.

OAVEN, RICHARD. Preliminary observations; General report and description by 

counties. [Lower and Upper Silurian.] Geological reconnaissance of Indiana, made in 1859-'60, Indianapolis, 1862, pp. 3-26, 30-91.

SHUMARD, B. F. Notice of some new and imperfectly known fossils from the Primordial Zone (Potsdam and Calciferous sand group) of Wisconsin and Mis- 

. souri. St. Louis Acad. Sci. Trans., vol. 2, 1862, pp. 101-107.

WHITNEY, J. D. [Stratigraphical geology.] Geol. Survey Wisconsin, vol. 1,1862, 

pp. 140-192.

1863.

BIGSBY, J. J. On the Cambrian and Hurouian formations. Quart. Jour. Geol. Soc,

London, vol. 19, 1863, pp. 36-^52. 

CAMPBELL, J. Report on the Gold Fields of Nova Scotia. Halifax, 1863, pp. 12.
WALCOTT.] LITERATURE. 33

COOK, GKORGK H. Report of Prof. George H. Cook upon the geological survey of 

New Jersey, and its progress during the year 1863, pp. 13.

DANA, JAMKS D. Manual of geology, 1st ed., New Haven, 1863.

DEVINE, T. Description of anew trilobite from the Quebec group. Canadian 

Naturalist, vol. B, 1863, pp. 95-98: 210,211.

HALL, JAMES. Preliminary notice of the fauna or! the Potsdam sandstone, with remarks on the previously known species of fossils and descriptions of some 

new ones from the sandstone of the Upper Mississippi Valley. 16th Ann. 

Rep. Regents Univ. State Cab. Nat. Hist.. 1863, pp. 119-220. Albany lust., 

Trans., vol. 5, 1867, pp. 93-195.

HAYDEN, F. V. On the geology and natural history of the Upper Missouri. Am. 

Philos. Soc. Trans., new ser., vol. 12, 1863, pp. 1-217, with map.

LOGAN, W. E. Geological Survey of Canada; Report of Progress from its Commencement to 1863. Montreal, 1863, pp. 983.

MATTHEW, G. F. Observations on the geology of St. John County, Now Brunswick. 

Canadian Naturalist, vol. 8, 1863, pp. 241-259.

WHITTLESEY, CHARLES. The Peuokie Mineral Range, Wisconsin. Eoston Soc. Nat. 

Hist., Proc., vol. 9, 1863, pp. 235-244.

1864.

MEEK, F. B., and F. V. HAYDEN. Paleontology of the Upper Missouri; a report 

upon collections made principally by the expeditions under command of 

Lieut. G. K. Warren in 1855-'56. Invertebrates. Sniithsouian Contributions, 

No. 172, 1864, pp. 136, plates.

WiNCHELL, ALEXANDER. Notice of a small collection of fossils from the Potsdam 

sandstone of Wisconsin and Lake Superior sandstone of Michigan. Am. Jour. 

Sci., 2d ser., vol. 37, 1864, pp. 226-232.

1865.

BAILEY, L. W. Observations on the geology of Southern New Brunswick. Froderictou, 1805, pp. 1-30, 31-122.

BAILY, W. H. The Cambrian rocks of the British Islands, with especial reference 

to the occurrence of this formation and its fossils in Ireland. Geol. Magazine, 

vol. 2, 1865, pp. 385-400.

BILLINGS, E. Paleozoic Fossils, vol. I. Containing descriptions and figures of new 

or little known species of organic remains from the Silurian rocks. 1860- 

'65. Montreal, 1865, pp.426. (Of this volume pp. 1-24 were issued in Nov., 

1861; pp. 25-56 issued Jan. 1862; pp. 57-168 issued in June, 1862; pp. 169- 

344 issued Feb., 1865; pp. 395-416 published in Canadian Naturalist, vol. 5, 

1860, pp. 301-324.)

HARTT, C. FRED. Preliminary notice of a fauna of the Primordial period in the vicinity of St. John, N. B. Observations on the geology of southern New Brunswick. 1865, pp. 30, 31.

LOGAN, W. E. Geological Survey of Canada. Atlas of maps and sections with an 

Introduction and Appendix. [To accompany report of Progress from commencement to 1863.] Montreal, 1865, 11 maps and sections.

MATTHEW, G. F. On the Azoic and Paleozoic rocks of southern New Brunswick. 

Quart. Jour. Geol. Soc., London,vol. 21, 1865, pp. 422-434, map. Canadian 

Naturalist, new ser., vol. 3, 1865, pp. 387-391.

1866.

LOGAN, W. E. Lower Silurian Rocks of North America. Geol. Surv. Newfoundland, 

Rep. Prog, for 1864, Montreal, 1866, pp. 45,46. Revised ed. 1881', pp. 47-50.

 Report for 1866. Geol. Surv. Canada. Rep. of Prog. 1863 to 1866; 1866, pp. 3-27.

LOGAN, W. E., and JAMES HALL. Geological map of Canada and part of the United 

States, from Hudson's Bay to Virginia and from the Missouri River to Newfoundland. Montreal, 1866.

MURRAY, ALEXANDER. Sequence and distribution of the rocks of the great Northern Peninsula. Geol. Survey Newfoundland. Rep. of Prog, for 1864. Montreal, 1866, pp. 10, 44. Revised edition 1881, pp. 5-47.

1867.

DAWSON, J. W. On recent geological discoveries in the Acadian provinces of British 

America. Am. Assoc.,Proc., vol. 16,1867, pp. 1J.7-119. Canadian Naturalist, 

new ser., vol. 3,1868, pp. 295-297,

Bull. 81 3
34 THE CAMBRIAN. IBULL. 81.

HITCHCOCK, C. H. The Winooski marble of Colchester, Vermont. Am. Assoc., Proc., 

vol.16, 1867, p. 119.

 The geology of Vermont. Am. Assoc., Proc., vol. 16, 1867, pp. 120-122. 

LYMAN, B. S. Ou the Lower Silurian brown hematite beds of America. Am. Assoc.,

Proc., vol. 16,1867, pp. 114-117. 

MACFARLANE, THOMAS. On the geological formations of Lake Superior. Canadian

Naturalist, new ser., vol. 3,1867-'68, pp. 177-201,241-256. 

PERRY, JOHN P. The red sandstone of Vermont and its relations. Am. Assoc., Proc.,

vol. 16, 1867, pp. 128-134.

1868.

AGASSIZ, ALEXANDER. On the position of the sandstone of the southern slope of a 

portion of Keweenaw Point, Lake Superior. Boston Soc. Nat. Hist., Proc., 

vol. 11,1868, pp. 244-246.

COOK, GEORGK H. Geology of New Jersey. (With 13 maps in portfolio and 7 pis. 

bound in volume.) Newark, 1868, pp. 900.

DAWSON, J. W. Acadinn geology. The geological structure, organic remains, and 

mineral resources of Nova Scotia, New Brunswick, and Prince Edward Island, 2d ed., London, 1868, pp. xxvi, 694, map.

HARTT, C. FRED. Fossils of the Primordial or Acadian group at St. John. In Dawson, Acadian geology, 1868, pp. 641-657.

HUNT,T. STERRY. On some points in the geology of Vermont. Am. Jour. Sci., 2d 

ser., vol. 46,1868, pp. 222-229.

MEEK, F. B. Preliminary notice of a remarkable new genus of corals, probably typical of a new family * * * from the Silurian rocks of Nevada Territory. 

Am. Jour. Sci., 2cl ser., vol. 45,1668, pp. 62-64.

 Note on Ethmopbyllum and Archeocyathus. Am. Jour. Sci., 2d ser., vol 46,

1868, p.144. 

MURRAY, ALEXANDER. Of the sequence and distribution of the formations. Report

upon tbe geological survev of Newfoundland for 1868, St. Johns, 1868, pp. 68.

Revised edition, 1881, pp. 137-186. 

PERRY, JOHN P. Queries on the red sandstone of Vermont and its relations. Boston

Soc. Nat. Hist., Proc., vol.11, 1868, pp. 341-353.

1869.

HAYDEN, F. V. Geological Report of the Exploration of the Yellowstone and Missouri Rivers, under the direction of Capt. W. F. Raynolds, 1859-'60. Washington, 1869, pp. 144, with a geological map.

HIND, H. Y. Report on the Waverly Gold District, with geological maps and sections. 

Halifax, 1869, pp. 62.

KEUR, W. C. Report of the State Geologist of North Carolina. Raleigh, 1869, pp. 57.

LAPHAM, I. A. Geological map of Wisconsin. Milwaukee, 1869.

MARSH, 0. C. Description of a new species of Protichmtes from the Potsdam sandstone of New York. Am. Jour. Sci., 2cl ser., vol. 48,1869, pp. 46-49.

MATTHEW, G. F., and L. W. BAILEY. Remarks on the age and relations of the metamorphic rocks of New Brunswick and Maine. Am. Assoc. Proc., vol. 18,1869, 

pp. 179-195. Canadian Naturalist, new ser., vol. 4,1869, pp. 326-328.

SAFFORD, JAMES M. Geology of Tennessee. Nashville, 1869, pp. 551,7 pis. and map.

S'HALER, N. S. [On the relations of the rocks in the vicinity of Boston.] Boston Soc. 

Nat. Hist., Proc., vol. 13, 1869, pp. 172-178.

1870.

HIND, H. Y. Preliminary Report on a Gneissoid Series Underlying the Gold-bearing 

Rocks of Nova Scotia,, and supposed to be the equivalent of the Laureutian 

system. Halifax, N. S., 1870, pp. 14.

 Report on the Sherbrooke Gold District, together with a paper on the gneisses 

of Nova Scotia, and an abstract of a paper on gold mining in Nova Scotia. 

Halifax, N. S., 1870, pp. 79.

 On two gneissoid series in Nova Scotia and New Brnnswick, supposed to be the 

equivalents of the Huronian (Cambrian) and Laurentian. Quart. Jour. Geol. 

Soc., London, vol. 26, 1870, pp. 46P-479.

 On the Laurentian and Huronian series in Nova Scotia and New Brunswick.

Am. Jour. Sci., 2d ser., vol. 49, 1870, pp. 347-355. 

HITCHCOCK, C. H. The geology of Vermont. In geology of northern New England,

1870, pp. 5. Note added May 25, 1882. 

HUNT, T. STERKY. On the geology of Eastern New England. Am. Jour. Sci., 2dser.,

vol. 50, 1870, pp. 83-90.
WALCOTT.] LITERATURE. 35

MEEK, F. B. Descriptions of fossils collected by the United States Geological Survey 

under the charge of Clarence King, esq. Phila. Acad. Sci., Proc., vol. 22, 

1870, pp. 56^64.

MUKRAY, ALEXANDER. Of the rocks and associated minerals [of Bonavisca Bay, etc,]. 

Report upon t be geological survey of Newfoundland for 1869, St. Johns, 1870. 

Revised edit ion, 1881, pp. 11)4-205.

RICHARDSON, .TAMISS. Report on the south shore of the St. Lawrence, below Quebec. 

Geol. Surv. Canada, report progress for 1866 to 1869,1870, pp. 119-141, map.

WHITE, C. A. General geology. Azoic, Lower Silurian, Upper Silurian, and Devonian systems. Geol. Survey Iowa, vol. 1, Des Moines, 1870, pp. 167-188.

1871.

FORD, S. W. Notes on the primordial rocks in the vicinity of Troy, N. Y. Am. Jour.

Sci., 3d ser., vol. 2, 1871, pp. 32-34. Canadian Naturalist, new sor., vol. 6,

1872, pp. 209-213. 

HAYDEN. F. V. Report of F. V. Haycleu [on the geological survey of Wyoming]. U.

S. Geol. Surv. of the Terr., 4th Ann. Report, 1871, pp. 11-81. 

HUNT, T. S. On the geology of the vicinity of Boston. Boston Soc. Nat. Hist., Proc.,

vol. 14, 1871, pp. 45-49. 

MEEK, F. B. Notice of a new brachiopod from the lead-bearing rocks at Mine La

Motte, Missouri. Phila. Acad. Nat. Sci., Proc., vol. 23, 1871, pp. 185-187. 

MURRAY, ALEXANDER. Of Primordial Silurian and related formations. Rep. Geol.

Surv. N. F. for 1870, St. Johns, 1870 [1871], pp. 30-43. Revised edition, London, 1881, pp. 232-241. 

SWALLOW, G. C. Remarks on the geological map and section of the rocks of Missouri.

American Naturalist, vol. 5,1871, pp. 541,542. Am. Asso., Proc., vol. 20,1871,

p. 262.

1872.

BAILEY, L. W. and G. F. MATTHEW. Preliminary report on the geology of southern 

N%w Brunswick. Geol. Surv. Canada, Rep. of Prog.,1870-'71, 1872, pp. 13-240.

HILLINGS, E. Note on the discovery of fossils in the " Winooski marble" atSwanton, 

Vermont. Am. Jour. Sci., 3d ser., vol. 3,1872, pp. 145-146. Canadian Naturalist, new ser., vol. 6, p. 351.

 On some fossils from the Primordial rocks of Newfoundland. Canadian Naturalist, new ser., vol. 6, 1872, pp. 465-479.

 On some new species of Potsdam fossils. Canadian Naturalist, new ser., vol. 6,

1872, pp. 213-226, 240. 

BRADLEY, F. H. On the discovery of the Quebec formation tn Idaho. Am. Jour. Sci.,

3d ser., vol. 4, 1872, p. 133. 

BROOKS, T. B., and R. PUMVELLY. On the age of the copper-bearing rocks of Lake

Superior. Am. Jour. Sci., 3d ser., vol. 3, 1872, pp. 428-432. 

DANA, JAMES D. Green Mountain geology. On the quartzite. Am. Jour. Sci., 3d

ser., vol. 3, 1872, pp. 179-186,250-256. 

FORD, S. W. Descriptions of some new species of Primordial fossils. Am. Jour. Sci.,

3d ser., vol. 3, 1872, pp. 419-422. 

HUNT, T. S. History of the names Cambrian and Silurian in geology. Canadian

Naturalist, now sor., vol. 6, 1872, pp. 281-312, 417-448. 

IRVING, R. D. On the age of the quartzites, Mchists, and conglomerates of Sauk

County, Wisconsin. Am. Jour. Sci., 3d ser., vol. 3,1872, pp. 93-99. Wisconsin Acad. Sci., Trane., vol. 1, 1872, pp. 129-137. 

MEEK, F. B. Report on the paleontology of eastern Nebraska. Final Report U. S.

Geological Survey of Nebraska, Washington, 1872, pp. 83-139. 

SELWYN, A. R. C. Notes and Observations on the gold fields of- Quebec and Nova

Scotia. Geol. Surv. Canada, ReportProg. for 1870-71, 1872, pp. 2S2-282. 

WHITNEY, J. D. [On some fossils from Eureka, Nevada.] California Acad. Sci.,

Proc., vol. 4, 1872,p. 200.

 Note on the occurrence of the " Primordial fauna " in Nevada. Am. Jour. 

Sci., 3d ser., vol. 3, 1872, pp. 84-86.

1873.

BRADLEY, FRANK, H. Report of Frank H. Bradley, geologist of the Snake River 

Division. U. S. Geol. Surv. of the Terr., 6th Ann. Rep., 1873, pp. 193-271.

 Explorations of 1872; U. S. Geological Survey of the Territories, under Dr. 

F. V. Havden; Snake River Division. AIU. Jour. Sci.. 3d sor.. vol. 6, 1873. 

pp. 194-207,
36 THE CAMBRIAN. [BULL. 81.

DAWSON, J. W. Impressions and footprints of aqnatic animals and imitative markings on Carboniferous rocks. Am. Jour. Sci., 3d ser., vol. 5,1873, pp. 16-24.

 Address [On fauna and species in geological time; on the Laurentian and

Primordial, and ou the so-called glacial period.] Canadian Naturalist, new

ser., vol. 7, 1873, pp. 1-11. 

FORD, S. W. Remarks ou the distribution of the fossils in the Lower Potsdam

rocks at Troy, N. Y., with descriptions of a few new species. Am. Jour.

Sci.> 3d ser., vol 5, 1873, pp. 134-1,40. 

HALL, JAMES. Notes ou some new and imperfectly known forms among the Brachiopoda, etc. 23d Ann. Rep. N. Y. State Mus. Nat. Hist., 1873, pp. 244-247. 

HALL, JAMKS, and R. P. WHITFIKLII. Notice of two new species of fossil shells from

the Potsdam sandstone of New York. 23d Rept. New York State Mus. Nat.

Hist., 1873, pp. 241,242. 

HAYDEN, F. V. Report of F. V. Haydeu. U. S. Geol. Surv. of the Terr., 6th-Ann.

Rep., 1873, pp. 13-85. 

HITCHCOCK, C. H. The Geology of Portland. Am. Assoc., Proc., vol. 22, part 2,1873,

pp. 163-175. 

LESLEY. J. P. The iron ores of the South Mountain along the line of the Harrisbnrg and Potomac Railway in Cumberland County, Pennsylvania. AID.

Phil. Soc., Proc., vol. 13,1873, pp. 3-21. 

MEEK, F. B. Preliminary paleontological report * * * with remarks on the

ages of the rocks, etc. U. S. Geol. Survey of the Territories, 6th Ann. Rep.,

1873, pp. 429-518.

 Reports ou the Geological Survey of tho State of Missouri, 1855-1871, 1873,

pp. 111-188. 

MURRAY, ALEX. Distribution of the Formations [of Avalon]. Report upon the

Geol. Survey of Newfoundland for the year 1872, St. John's, 1873, pp. 14-

34. Revised edition, London, 1881, pp. 279-21)7. 

NEWBEHUY, J. S. Circles of deposition in American sedimentary rocks. Am. Assoc.

Proc., vol.22, 1873, part 2, pp. 185-196. Canadian Naturalist, new ser., vol.

7,1873, pp. 163-164. 

ROMINGEK, C. Paleozoic rocks. Geol. Survey Michigan, Upper Peninsula, 1869-1873,

vol. 1, pt. 3, 1873, pp. 1-105. 

SEDGWICK, ADAM. [On the classification of the Cambrian rocks.] A Catalogue of

the Collection of Cambrian and Silurian Fossils contained in the Geological

Museum of the University of Cambridge, by J. W. Salter, 1873, pp. ix-xxxiii. 

WINCHELL, N. H. General sketch of the geology of Minnesota. Geol. and Nat. Hisfc.

Survey Minnesota, First Ann. Rep. for 1872, 1873, pp. 40-48,60-118.

 Preliminary Geological Map of Minnesota, 1872. Geol. and Nat. Hist. Survey 

Minnesota. First Ann. Rep. for 1872, 1873. Map faces p. 45.

1874.

BRADLEY, FRANK H. Note on the occurrence of metamorphic Silurian rocks in 

North Carolina. Am. Jour. Sci., 3d ser., vol.8, 1874, p. 390.

BKOADHEAD, G. C. Geological Survey Missouri. Including tield work of 1873-74, 

vol. 1. = Jefferson City, 1874, pp. 18-34, 322-370,

BUCKLEY, S. B. First Annual Report of the Geological and Agricultural Survey of 

Texas. Houston, 1874, pp. 142.

COMSTOCK, T. B. Geological report. Report upon the Reconnaissance of Northwestern Wyoming, made in the summer of 1873, by William A. Jones, 1874, 

pp. 85-184, with a colored geological map.

COOK, GEO. H. Geological Survey of New Jersey. Map of northern New Jersey, 

showing the iron ore and limestone districts, 1874.

DANA, JAMES D. Reasons for some of the changes in the subdivisions of geological 

time in the new edition of Daua's Manual of Geology. Am. Jour. Sci., 3d 

ser., vol.8,1874,pp.213-216.

GILBERT, G. K. On the ago of the Touto sandstone. (Abstract.) Washington Phil. 

Soc. Bull., vol. 1,1&74, p. 109.

HAYDKN, F. V. Report of F. V. Hayden, U. S. Geologist. U. S. Geol. Surv. of tho 

Terr., Seventh Ann. Rep, 1874, pp. 17-82.

HITCHCOCK, C. H. Physical history of New Hampshire. Geology of New Hampshire, Concord, 1874.vol. 1, pp. 506-545.

 History of the geological surveys of New Hampshire. Geology of New

Hampshire, vol. 1, 1874, pp. 3-58. 

IRVING, R. D. On the age of the copper-bearing rocks of Lake Superior; and on the

westward continuation of the Lake Superior synclinal. Am. Jour. Sci., 3d

ser.; vol, 8,1874, pp. 46-56,
WAI.COTT.] LITERATURE.. 37

InviNG, R. D. On some points in the geology of northern Wisconsin. Wisconsin 

Acad. Sci., Trans., vol.2, 1874, pp. 107-119.

JENNEY, W. P. (Recent explorations in the geology of Western Texas.) New York 

Lyceum Nat. Hist., Proc., vol. 2, 1874, pp. 68,69.

KILLEBUEW, J. B. Resources of Tennessee. Nashville, 1874, pp. 20-46.

NEWBERRY, J. S. Remarks on geology of Western Texas. Now York Lyceum Nat. 

Hist., Proc., vol.2,1874, pp. 69,70.

PEALE, A. C. Report of A.C.Peale, M. D., geologist of the South Park Division. 

U. S. Geol. Surv. of the Terr., Seventh Ann. Rep., 1874, pp. 193-273.

WHITE, C. A. Preliminary report upon invertebrate fossils collected by the expeditions of 1371, 1872, and 1873, with descriptions of new species. Geog. 

and Geol. Sur. West of 100th Mer., Lieut. Wheeler in charge, Washington, 1874, pp. 27.

WiNCHELL, N.H. The geology of the Minnesota Valley. Geol. and Nat. Hist. Snr. 

Mimi., Second Ann. Rep. for 1873, 1874, pp. 127-212.

1875.

BRADLEY, FRANK H. On the Silurian age of the southern Appalachians. Am. Jour.

Sci., 3d ser., vol. 9,1875, pp. 279-288, 370-383. 

DODGE, W. W. Notes on the geology of eastern Massachusetts. Boston Soc. Nat.

Hist., Proc., vol. 17, 1875, pp. 388-419. 

FONTAINE, WILLIAM M. On the primordial strata of Virginia. Am. Jour. Sci., 3d

ser., vol. 9,1875, pp. 361-369,416-428. 

FORD, S. W. Note on the discovery of a new locality of primordial fossils in Rensselaer County, New York. Am. Jonr. Sci., 3d ser., vol. 9,1875, pp. 204-206. 

GILBERT, G. K. Report on the geology of portions of Nevada, Utah, California, and

Arizona examined in the years 1871 and 1872. Geog. and Geol. Expl. and

Surv. West of the 100th Mer., Lieut. Geo. M. Wheeler in charge, vol.3, Geology, 1875, pp. 17-187. 

 Report on the geology of portions of New Mexico and Arizona examined in

1873. Geog. and Geol. Expl. and Surv. West of the 100th Mer., Lieut. G. M.

Wheeler in charge, vol. 3, 1875, pp. 503-567. 

HAYDEN, F. V. Catalogue of the collections in geology Mid natural history obtained

by the expedition under command of Liout. G. K. Warren. Appx. to Rept. Sec.

of War, in Rept. of Topog. Eng., for 1858 (reprint edition of 1875, pp. 59-125,

map). 

HICKS, HENRY. The physical conditions under which the Cambrian and Lower

Silurian rocks were probably deposited over the European area. Quart. Jour.

Geol. Soc. London, vol. 31, 1875, pp. 552-558. 

HITCHCOCK, C. H. Remarks on the stratigraphic structure of the Cambrian and

Cambro-Silnriau rocks of western Vermont. Boston Soc. Nat. Hist., Proc.,

vol. 18,1875, pp. 191-193. 

HOWELL, EDWIN E. Report on the geology of portions of Utah, Nevada, Arizona, and

New Mexico examined in the years of 1872 and 1873. Geog. and Geol. Expl.

and Sur. West of the 100th Mer., Lient. Geo.M. Wheeler in charge, vol.3,

Geology, 1875, pp. 227-301. 

HUNT, T. STK.KKY. (Remarks on Massachusetts geology.) Boston Soc. Nat. Hist.,

Proc., vol. 17, 1875, pp. 509, 510. 

IRVING, ROLAND D. Note on some new points in the elementary stratification of

Primordial and Canadian rocks of south-central Wisconsin. . Am. Jour. Sci.,

3d ser., vol. 9, 1875, pp. 440, 443. 

KERR, W. C. Report of the geological survey of North Carolina, vol. 1. Raleigh,

1875, pp. xviii, 325. 

MARVINE, A. R. Report on the geology of route from St. George, Utah, toGila River.

Arizona, examined in 1871. Geog. and Geol. Expl. and Sur. West of 100th

Mer., Lient. Geo. M. Wheeler in charge, vol. 3, Geology, 1875, pp. 189-225. 

POWELL, J. W. Exploration of the Colorado River of the West and its tributaries,

explored in 1869,1870,1871, and Ib72. Washington, 1875, pp. 214. 

ROGERS, W. B. On the Newport conglomerate. Boston Soc. Nat. Hist., Proc.,vol. 18,

1875, pp. 97-101.

SMITH, E. A. Geological Survey of Alabama. Report of progress for 1874. Montgomery, Alabama, 1875, pp. 139. 

WHITE, C. A. Report upon the invertebrate fossils collected in portions of Nevada,

Utah, Colorado, New Mexico, and Arizona by parties of the expeditious of

1871-74. Expl. and Surv. West of the 100th Mer., Lieut. Geo. M. Wheeler,

in charge, vol. 4, pt. i, 1875, pp. 219.
38 THE CAMBRIAN. IBULL.SI.

1876.

BUCKLEY, S. B. Second Annual Report of the Geological and Agricultural Survey of

Texas. Houston, 1876, pp. 96.

C'ISOSBY,W. O. Report on the Geological Map of Massachusetts. Boston,1876, pp. 42. 

DANA, Emv. S., and G. B. GRINNELL. Geological report. Report of a geological reconnoissance, from Carroll, Montana Territory, on the upper Missouri, to tbe

Yellowstone Park and return, made in the summer of 1675, under Win. Ludlow,

1876, pp. 93-137. 

FORD, S. W. On additional species of fossils from the Primordial of Troy and Lansingburgh, Rensselaer County, New York. Am. Jonr. Sci., 3d ser., vol. 11,

1876, pp. 309-371. 

HUNT, T. STERKY. On the history of the crystalline stratified rocks. Am. Assoc.

Proc., vol. 25, 1876, pp. 205-208.

 Tbe Cornwall iron mine and some related deposits in Pennsylvania. Am.

Inst. Mining Eng.,Trans., vol.4, 1876, pp. 319-324. 

KAYSER, EMANUKL. Ueber pritnordiale nnd untersiluriscbe Fossilien ans der ArgeutiniHcheu Republik. Beitriige zur Geologic und Pal aeon tologio der Argentinischen Repnblik; part 11, Palaeoutologischer Theil, I Abtheiluug, 1876,

pp. 33. 

KING, CLARENCE. Paleozoic subdivisions on the Fortieth parallel. Am. Jour. Sci.,

3d ser., vol. 11,1876, pp. 475-482. 

LITTLE, GEORGE. Geological Survey of: the State of Georgia. Hand-book of tbe State

of Georgia, with geologic map of the State, by T. P. Janes, 187(5, pp. 17-61. 

LLOYD, T. G. B. Geological notes from tbe State of New York. Quart. Jour. Geol.

Soc., London, 1876, vol. 32, pp. 76-79. 

PEALE, A. C. [Report 01* Middle Division.] Stratigraphy Paleozoic formations. U.

S. Geoi. andGeog. Surv. of tbe Territories. Ann. Rep. for 1874, 1876, pp. 110-

120. 

POWELL, J. W. Report on the Geology of the Eastern Portion of the Uinta Mountains

and a Region of Country Adjacent Thereto. Washington, 1876, pp. 3-73,

136-210. 

SMITH, EUGENE A. Report of Progress of tbe Geological Survey of Alabama for 1875.

Montgomery, 1876, pp. 220. 

SWEET, E. T. Notes on the geology of northern Wisconsin. Wisconsin Acad. Sci.,

Trans., vol. 3,1876, pp. 40-55. 

WHITE, CHARLES A. Invertebrate paleontology of the plateau province, together

with notice of a few species from localities beyond its limits in Colorado.

Report on the geology of tbe eastern portion of the Uinta Mountains, by J.

W. PowelL Washington, Ib76, pp. 74-135. 

WHITFIELD, R. P. Descriptions of new species of fossils. Report of a reconnoissance

from Carroll, Montana Territory, on. the Upper Missouri, to the Yellowstoue

Park and return, made in the summer of 1875, under William Ludlow, 1876,

pp. 139-145.

 Description of new fossils. Report of Geol. Recon. of Black Hills. Appx. PP.

of report of Chief of Engineers, 1876, pp. 1202, 1*03. 

WINCHELL, N. H. Notes on tbe deep well drilled at East Minneapolis, Minnesota, in

1874-'75. Minnesota Acad. Sci. Bull., vol. 1,1876, pp. 187-L-9.

 Report on tbe geology of Fillinore County. Geol. and Nat. Hist. Survey 

Minnesota; 4th Ann. Rep., for 1875, 1876, pp. 13-74, map.

 Geological report [of a reconnaissance of the Black Hills of Dakota, made in 

tbe summer of 1874, by Capt. William Ludlow]. Report of the Chief of Engineers, Appx. PP, Itt76, pp. 1131-1172.

1877.

BROADHEAD, G. C. The southeastern Missouri lead district. Am. Inst. Mining Eng.

Trans., vol. 5, 1877, pp. 100-107. 

CHAMBEKLIN, T. C. [Geology of eastern Wisconsin.] Chapters 7 and 8, Lower and

Upper Silurian. Geology of Wisconsin, Survey of 1873-77, vol. 2, 1«77,

pp. 257-394. 

CHAPMAN, E. J. On the probable nature of the supposed fossil tracks known as Protichnites and Cliinactichnites. Canadian Journal, new ser., vol. 15, 1877,

pp. 486-490. 

DANA, JAMES D. An account of the discoveries in Vermont geology of the Rev.

Augustus Wing. Am. Jour. Sci., 3d ser., vol. 13,1877, pp. 332-347,405-419;

vol. 14,1877, pp. 36-37. 

FLETCHER, HUGH. Report of explorations and surveys in Cape Breton, Nova Scotia

Geol. Surv. Canada, Rep. Progress for 1875-76, 1877, pp. 369-418.
WALCOTT.] LITERATURE. 39

FORD, S. W. Note ou Microdiscus speciosus. Am. Jour. Sci., 3d ser., vol. 13,1877, 

pp. 141, 142.

 On some embryonic forms of trilobites from the Primordial at Troy, New

York. Am. Jour. Sci., 3d ser., vol. 13,1877, pp. 265-273. 

HAGUE, ARNOLD, and S. F. EMMONS. Descriptive geology. U. S. Geol. Expl. of the

Fortieth Par. under Clarence King, vol. 2. 1877, pp. 890. 

HALL, JAMES, and R. P. WHITFIELD. Paleontology [of the 40th parallel]. General

remarks. U. S. Geol. Survey of the 40th parallel, vol. 4, 1877, pp. 199-302. 

HITCHCOCK, C. H. Geology of New Hampshire, Concord, 1877, vol. 2, pp. 3-36.

 Geological map of New Hampshire and Vermont, with notes on topography 

and geology. In Geology of Northern New England, 1877, pp. 17.

JRVING, ROLAND D. The Lower Silurian rocks. (Geology of central Wisconsin.) 

Geology of Wisconsin, Survey of 1873-1877, vol. 2,1877, pp. 525-607.

 Note 011 the age of the crystalline rocks of Wisconsin. Am. Jour. Sci., 3d

ser., vol. 13, 1877, pp. 307-309. 

MEEK, F. B. Paleontology. Report of the Geol. Sur. of the Fortieth Parallel, vol.

4. 1877 pp. 197,

MILNE, JOHN, and ALEXANDER MURRAY. On the rocks of Newfoundland. Geological Magazine, vol. 4, new ser., decade n, 1877, pp. 251-262.

STRONG, MOSES. Geological formations. [Geology and topography of the lead 

regions. 1 Geology of Wisconsin, Survey of 1873-77, vol. 2, 1877, pp. 668-688.

WHITFIKLD, R. P. Preliminary report on the paleontology of the Black Hills. U.

5. Geol. and Geog. Surv. of the Rocky Mountain Region, 1877, pp. 49.

1878.

DAWSON, J. W. Supplement to the second edition of Acadian Geology, containing 

additional facts as to the geological structure, fossil remains, and mineral 

resources of Nova Scotia, New Brunswick, and Prince Edward Island, London, 1878, pp. 10?.

ENDLICIT, F. M. Report of F. M. Eadlich, geologist of the White River division. 

U. S. Geol. Snrv. of the Terr., 10th Ann. Rep., 1878, pp. 61-131.

FLETCHER, HUGH. Report on the geology of part of the counties of Victoria, Cape 

Breton, and Richmond, Nova Scotia. Geol. Surv. Canada, Rep. progress for 

1876-77. Montreal, 1878, pp. 402-456.

FORD. S. W. On certain forms of Brachiopoda occurring in the Swedish Primordial. 

Am. Jour. Sci., 3d ser., vol. 15, 187R, pp. 364-366.

 Note on the development of Olenellus asaphoidcs. Am. Jour. Sci., 3d ser., 

vol. 15, 1878, pp. 129,130.

 Note on Lingnle.Ua coelata. Am. Jour. Sci., 3d ser., vol. 15, 1378, pp. 127-129.

 Two new species of Primordial fossils. Am. Jour. Sci., 3d ser., vol. 15, 1878, 

pp. 124-127.

FRAZKR, PERSIFOR, ir. (Note on the Martic anticlinal and on ripple marks on a 

slab of limestone.) Am. Phil. Soc., Proc., vol. 17, 1878, p. 725.

HUNT, T. S. Special report on the trap dikes and Azoic rocks of southern Pennsylvania. 2d Geol. Surv. Pa., E., 1878, pp. 253.

 On the geology of the Eozoic rocks of North America. (Abstract.) Boston 

Soc. Nat. Hist., Proc., vol. 19, 1878, pp. 275-279.

KING, CLARENCE. Systematic geology. U. S. Geol. Exploration of the Fortieth 

Parallel, Clarence King, geologist in charge, vol. 1, 1878, pp. xii, 803.

MATTHEW, G. F. Report on the slate formations of the northern part of Charlotte 

County, New Brunswick. Geol. Surv. Canada, Rep. progress for 1876-77. 

Montreal, 1878, pp. 321-350.

PRIME, FREDERICK, Jr. On the Paleozoic rocks of Lehigh and Northampton Counties, Pennsylvania. Am. Phil. Soc., Proc., vol. 17,1878, pp. 248-254.

 Monocraterion lesleyi, n. sp. Appendix to report on the Brown hematite 

deposits of the Siluro-Cambrian limestones of Lehigh County. 2cl Geol. Surv. 

Penn., DD, 1878, pp. 79, 80.

 On the discovery of Lower Silurian fossils in limestone associated with hydromica slates in eastern Pennsylvania. Am. Jour. Sci., 3d ser., vol. 15, 1878, 

pp. 261-269.

SMITH, EUGENE A. Outline of the geology of Alabama. Berney's Hand-book of 

Alabama, 1878, pp. 129-196.

 The iron ores of Alabama, with special reference to their geological relations.

Am. Assoc., Proc., vol. 27, 1878, pp. 246-258. 

WHITEAVES, J. F. On some Primordial fossils from southeastern Newfoundland.

Am. Jour. Sci., 3d. ser., vol. 16, 1878, pp. 224-226. 

WHITKIELD, R. P. Preliminary descriptions of new species of fossils from the lower

geological formations of Wisconsin. Geol. Sur. of Wisconsin, Ann. Rep. for

1877, 1878, pp. 50-89.
40 THE CAMBRIAN. [BULL. 81.

WINCHELL, N. H. The geology of Rock and Pipestone Counties. Geol. and Nat.

Hist. Survey Minnesota, 6th Ann. Rep. for 1877, 1878, pp. 93-111. 

WOOSTER, Li. C. Work in St. Croix, Dunn, and adjacent counties. GeoL. Survey

Wisconsin, Ann. Rep. for 1877, 1878, pp. 36-11.

1879.

BAILEY, L. W. Report on the pre-Silurian (Hnronian) and Cambrian or Primordial 

Silurian rocks of southern New Brunswick. Gool. Surv. Canada, Rep. of 

Prog., 1877-78, 187'J, pp. 34 DD.

BELL, ROBKRT. Report on an exploration of the east coast of Hudson's Bay, 1877. 

Geol. Surv. Canada, Rep. Prog, for 1877-78, 1879, pp. 37C.

CAMPBELL, J. L. Silurian formation in Central Virginia. Am. Jour. Sci., 3d sor. 

vol. 18, 1879, pp. 16-29. Geology of Virginia. Balcony Falls. The Blue 

Ridge and its geological connections. Some theoretical considerations. 

Am. Jour. Sci., 3d ser, vol. 18, 1879, pp. 435-445.

ENDLICH, F. M. Report on the geology of the Sweet water district. U. S. Geol. 

Siwv. of the Terr., llth Ann. Rep., 1879, pp. 3-150.

(FRAZER, PJSIISIFOK.) [On the relations of the South Mountain rocks in Pennsylvania.] Am. lust. Mining Eng. Trans., vol. 7, 1871), pp. 336-339.

HITCHCOCK, C. H. Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, 

and Connecticut. (Geological formations.) Macfarlauo's Am. Geol. R. R. 

Guide, 1879, pp. 56-66.

HUNT, T. S. Dominion of Canada. (Geological formations.) Macfarlane's Am. 

Geol. R. R. Guide, 1879, pp. 52-55.

FEALE, A. C. Report on the geology of the Green River district. U. S. Geol. Surv. of 

the Terr., llth Ann. Rep., 1879, pp. 509-644.

ROGERS, WILLIAM B. Virginia and West Virginia. (Geological formations.) Macfarlane's Am. Geol. R. R. Guide, 1879, pp. 179-185. "Table of the geological 

formations found in Virginia and West Virginia. The Virginias, vol. 1,1880, 

pp. 14, 15; vol. 3, 1882, pp. 61.

SAFFOHD, JAMES M. Tennessee. (Geological formations.) Macfarlane's Am. Gool. 

R. R. Guide, 1879, pp. 196-199.

SELWYN, A. R. C. Report of observations on the stratigraphy of the Quebec group 

and the older crystalline rocks of Canada. Geol. Surv. Canada, Rep. of 

Prog. 1877-'78, pp. 15A. Canadian Naturalist, new ser., vol. 9,1879, pp. 17-31.

ST. JOHN, ORESTES. Report of the geological Held work of the Teton division. U. 

S. Geol. Surv. of the Terr., llth Ann. Rep., 1879, pp. 321-508.

WALCOTT, C. D. Descriptions of new species of fossils from the Calciferous formation. 32d Rep. State Mus. Nat. Hist. N. Y., 1879, pp. 129-131.

WHITE, C. A. Report on the paleoutological field \vork for the season of 1877. llth 

Ann. Rep. U. S. Geol. Surv. of the Territories for 1877, 1879, pp. 251-265. 

(General discussion.)

1880.

BAILEY, L. W., G. F. MATTHEW, andR. W. ELLS. Report on the geology of southern 

New Brunswick embracing the counties of Charlotte, Simbury, Queens, 

Kings, St. John, and Albert. Geol. Survey Canada, Rep. of Prog., 1878-79, 

1880, pp. 26D.

CAMPBELL, J. L. The Silurian formation in'Central Virginia. (Revised.) The Virgiuia.s, vol. 1, 1880, pp. 41-15, 54-56.'

 The mineral resources and advantages of the country adjacent to the James

River and Kanawha Canal and the Buchanan and Clifton Forge Railway.

The Virginias, vol.1, 1880, pp. 2-8. 

CROSBY, W. 0. Contributions to the geology of eastern Massachusetts. Boston Soc.

Nat. Hist., occasional papers, No. 3,1880, pp. 286. 

FORD. S. W. Note on the trilobite, Atops triliueatus of Emmons. Am. Jour. Sci.. 3d

ser., vol. 19,1880, pp. 152,153. 

FRAZER, PERSIFOR, Jr. The geology of Lancaster County. Second Geol. Survey

Penu., Rep. progress in 1877, CCC. Harrisburg, 1880, pp. x, 350. 

IRVING, R. D. The mineral resources of Wisconsin. Am. lust. Mining Eng. Trans.,

vol.8, 1880, pp. 478-508.

 The Lake Superior or Potsdam sandstone. [Geology of the eastern Lake 

Superior district.] Geol. of Wisconsin, vol. 3, 1880, pp. 207-210.

 Geological structure of Northern Wisconsin. [General geology of the Lake 

Superior region.] Geol.of Wisconsin, vol. 3.1380, pp. 1-25.

MARCOU, JULES. Sur les colonies dans les roches taconiques des bords du lao 

Champlaiu. Soc. ge"ol., France, Bull., 3e s6r., vol.9,1880, pp. 18-46.
WAT,COTT.J LITERATURE. 41

MARR, J. E. On the pro-Devonian rocks of Bohemia. Quart. Jour. Geol. Soc. London, vol. 36, 1880, pp. 591-619.

NEWTON, HUNRY. Geology. Section IV. The Silurian. The Potsdam sandstone. 

U. S. Geog. and Geol. Survey of the Rocky Mountain region, J. W. Powell in 

charge: Report on the Black Hills of Dakota. 1880, pp. dO-107.

STRONG, MOSES. Geology of the upper Sfc. Croix district. Geology of Wisconsin, 

survey of 1873-1879, vol. 3,1880, pp. 390-428.

SWEET, E. T. Lake Superior sandstone. [Geology of the Western Lake Superior 

District.] Geology of Wisconsin, survey of 1873-1879, vol. 3,1880, pp. 350-352.

WADSWOKTH, M. E. Notes on the geology of the iron and copper district of Lake 

Superior. Cambridge Mus. Comp. Zool. Bull., vol 7,1880, pp. 157.

WALCOTT, C. D. The Permian and other Paleozoic groups of the Kanab Valley, Arizona. Am. Jour. Sci., 3d ser., vol. 20,1880, pp. 221-224.

WIIITK, C. A. Note on Acrothele. U. S. Nat. Mns. Proc., vol. 3,1880, p. 47.

WIUTKIELD, R. P. Paleontology of the Black Mills of Dakota. Report on the geology and resources of the Black Hills of Dakota, 1880, pp. 325-408.

WINCHELL, N. H. Section of a deep well at Etnmetshurgh, Iowa. Minn. Acad. Sci. 

Bull., vol. 1,1880, pp. 387, 388.

1881.

CROSBY, W. O. Geology of Frenchman's Bay. Boston Soc. Nat. Hist., Proc. vol. 21, 

1881, pp. 109-117. Geology of Frenchman's Bay, Maine, just east of Mt. Desert Island. Am. Jour. Sci., 3d ser., vol. 23,188:2, p. 64.

DUTTON, CLARENCE E. The physical geology of the Grand Canon District. U. S. 

Geol. Survey, 2cl Ann. Rep. 1880-'81,1881, pp. 47-166.

FORD, S. W. Remarks on the genus Obolella. Am. Jour Sci., 3d ser., vol. 21,1881, pp. 

131-134.

 Embryonic forms of trilohites from the Primprdial rocks of Troy,N. Y. Am.

Jour. Sci., 3d ser., vol. 22,1881, pp. 250-259. 

HAGUE, ARNOLD. Report [on work in Eureka District], U. S. Geol. Survey, 2d Ann. *

Rep., 1880-'81,1881, pp. 21-35. 

HALL, CHARLES E. The geology of Philadelphia County and of the southern parts of

Montgomery and Bucks. 2d Geol. Survey Pa., C6, 1881pp. xvii,xvm,U3. 

LAPWORTH, CHAS. Materials for the correlation of the Lower Pakeozoic rocks of

Britain and Scandauavia. Geological Magazine, new ser., decade n, vol. 8,

1881, pp. 260-266,317-322.

1882.

BROADMICAD, G. C. Marble of southeast Missouri. Kansas City Review, vol. 5,1882,

pp. 523-526. 

FRAZER, PERSJFOR. M6moire sur la Ge"ologio de la parte sud-est do la Pennsylvanie.

Lille, 1882, pp. 179.

GKIKIE, ARCHIBALD. Text Book of Geology. London, 1882, pp. xi, 971. 

HAGUE, ARNOLD. Abstract of report on geology of the Eureka district, Nevada.

U. S. Geol. Survey, 3d Annual Report, 1881-18&2,1882, pp. 237-290. 

KLOOS, J. H. Geological notes on Minnesota. (Translated by N. 11. Winchell.)

Geol. and Nat. Hist. Survey Minnesota, 10th Ann. Rep. for 1881,1882, pp.

1.75-200. 

RICHTOFENT, F. F. von. Geologischo Boobachtungen am Roiseweg dnrch die siidliche Mantschurei. Drittes Capitel, in "China, ErgobnisseReison unddarauf

gegrundeter Studien," vol. 2,1882, pp. 69-124. 

STRONG, MOSES. Geological formations. [Geology of the Mississippi region north

of the Wisconsin River.] Geology of Wisconsin, Survey of 1873-1879, vol. 4,

1882, pp. 38-91. 

TODD, JAMES E. A description of some fossil tracks from the Potsdam sandstone.

Wisconsin Acad. Sci., Trans., vol 5,1882, pp. 276-281. 

WADSWORTK, M. E. On the relation of the Quincy granite to the primordial argillite

of Braiutree. Massachusetts. Boston Soc. Nat., Hist. Proc., vol. 21, 1882, pp.

274-277. 

WIIITFIELD, R. P. Paleontology [of Wisconsin]. Geology of Wisconsin, vol. 4,1882,

pp. 163-363.

WINCHELL, N. H. The Potsdam Sandstone. Geol. and Nat. Hist. Survey Minnesota, 10th Ann. Rep. for 1881,1882, pp. 123-136.

 The geology of the deep well drilled by C. C. Whelpley at Minneapolis, at 

the "C" Washburn Mill. Geol. and Nat. Hist., Survey Minnesota, 10th 

Ann. Rep. for 1881,1882, pp. 211-217.

WOOSTER, L. C. Detailed Geology. [Geology of the lower St. Croix district.] 

Geology of Wisconsin, Survey of 1873-1H79, vol. 4,1882, pp. 109-130.

YOUNG, A. A. Further observations on tbo crystallized sands of the Potsdam sandstone of Wisconsin. Am. Jonr. Sci., 3d ser., vol. 24,1882, pp. 47-49.
42 THE CAMBRIAN. [BULL. 81.

1883.

CAMPBELL, J. L., and W. H. RUFFNER. A Physical Survey extending from Atlanta, 

Georgia, across Alabama and Mississippi to the Mississippi River, along the 

line of the Georgia Pacific Railway. New York, 1883, pp. 3-117.

CHAMBERLIN, T. C. General geology. Historical geology. Palaeozoic era. Geol. 

Wisconsin, Survey of 1873-1879, vol. 1,1883, pp. 119-200.

 The copper-bearing series of Lake Superior. Science, vol. 1,1883, pp. 453-455. 

DAMES, WILHELM. Cambrische trilobiten von Liau-Tung. In China, by F. F. von

Richtof'en, vol. 4, 1883, pp. 1-3(5, pis. 1 and 2.

D(AWSON), J. W. Impressions on Potsdam sandstone. Science, vol. 1, 1883, p. 177. 

D'lNViLLiERS, E. The Geology of the South Mountain Belt of Berks County, 2d

Geol. Sur. of Penna. 1)3, vol. 2, part 1, 1883, pp. xxii-441. 

ELLIOTT, JOHN B. The age of the Southern Appalachians. Ain. Jonr. Soi., 3d ser.,

vol. 25, 1883, pp. 282-298. 

ETHKRIDGE, R., Jr. Trilobites and other fossils from the Mersey River district.

Papers and Proc. Roy. Soc. Tasmania for 1882-1883, pp. 151-158. 

FKRRIER, W. F. Notes on a fossil track from the Potsdam sandstone of northern

Now York State. Canadian Naturalist, new ser., vol. 10, 1883, pp. 466,467. 

FONTAINK, W. M. Notes on the mineral deposits at certain localities on the western

part of the Blue Ridge. The Virginias, vol. 4, 1883, pp. 21,22,42-47,55-59,

73-76,92,93.

 [Letter on relations of Archaean and associated formations in Virginia.] 

Gool. Chester Co., Pa. 2d Geol. Snrv. Pa., C4. 1883, pp. xiii-xvi.

FRAZER, PKRSIFOR. Geological notes on the several townships of Chester County. 

2d Geological Sur. Ponn. The Geol. of Chester County, C4,1883, pp. 215-345.

HATTON, JOSEPH, and M. HAKVEY. Geology of Newfoundland. Newfoundland, the 

oldest British Colony, its^ history, its present condition, and its prospects in 

the future. London, 1883, pp. 178-187. Boston, 1883, pp. 150-157.

HUNT, T. STERRY. The Geology of Lake Superior. Science, vol. 1,1883, pp. 218,219.

 The geology of Port Henry, New York. Canadian Naturalist, new ser.,

vol. 10, 1883, pp. 420-422. 

IRVING, R. D. The copper-bearing rocks of Lake Superior. U. S. Geol. Survey,

Monographs, vol. 5, 1883, pp. xvi,464. U. So Geol. Survey, 3rd Ann. Rep.

1881-'82,1883, pp. 89-188. '

 The copper-bearing rocks of Lake Superior. Science, vol. 1, 1883, pp. 140,

141, 359, 360. 422. 

LESLEY, J. PETER. The Geology of Chester County after the surveys of Rogers,

Frazer, and Hall. (With plate and map.) 2d Geol. Surv. Penu. CCCC, 1883,

pp. i-xx, 1-54, 63-213, 351-354, 

LEWIS, II. CARVEL. The Geology of Philadelphia. Franklin Institute Jour., 3d

ser., vol. 85, 1883, pp. 359-374, 422-427. 

MARK, JOHN E. The classification of the Cambrian and Silurian rocks. The Sedgwick Prize Essay for the year 1882. Cambridge and London, 1883, pp. xxiv,

147.

MATTHEW, G. F. Illustrations of the fauuaof the St. John group. Royal ?oc. Canada, Proc. and Trans., vol. 1, 1883, section iv, pp. 87-108, pp. 271-279. 

PRIME, FREDERICK, Jr. Geology of Lehigh and Northampton Counties. 2d Geol.

Surv. Pa., D3, vol. 1, 1883, pp. 161-212, 2 maps. 

SELWYN, A. R. C. Age of the rocks on the northern shore of Lake Superior. Science,

vol. 1, 1883, pp. 11, 221.

 Notes on the geology of the southeastern portion of the Province of Quehec. 

Gool. Surv. Canada, Rep. Prog., for 1880, '81-'82,1883, pp. 1A-7A.

SMITH, EUGENE A. Geological features and divisions of Alabama. Geol. Surv. Alabama, Rept. for 1881 and 1882,1883, pp. 178-181, 192-210.

ST. JOHN, ORESTKS. Report on the geology of the Wind River district. U. S. Geol. 

Surv. of the Terr., 12th Ann. Rep., 1883, pp. 173-269.

WADSWORTH, M. E. The Argillite and conglomerate of the Boston Basin. Boston 

Soc. Nat. Hist., Proc., vol. 22, 1883, pp. 130-133.

WALCOTT, C. D. The Cambrian system, in the United States and Canada. Washington Phil. Soc., Bull., vol. 6, 1883, pp. 98-102.

 Pro-Carboniferous Strata in the Grand Cauon of the Colorado, Arizona. Am.

Jour. Sci., 3d ser., vol. 26, 1883, pp. 437-442, 484.

WHITNEY, J. D. Geology of Lake Superior. Science, vol. 1, 1883, p. 39. 

WINCHELL, N. H. The Lake Superior rocks. Science, vol, 1, 1883, p. 334.
WALCOTT.] LITERATURE. 43

1884.

CAMPBELL, J. L. Geology of the Blue Ridge near Balcony Falls, Virginia ; a modified view. Am. Jour. Sci., 3d ser., 1884, vol. 28, pp; 221-223. The Virginias, 

vol. 5, 1884, p. 145.

CAMPBELL, J. L. tind H. D. The Snowdon slate quarries. The Virginias, vol. 5, 1884, 

pp. 162, 163, 170.

CHESTER, FREDERICK D. 'Preliminary notes on the geology of Delaware. Laurentian, 

Paleozoic, and Cretaceous areas. Phila. Acad. Sci., Proc., vol. 36, 1884, pp. 

237-259.

COOK, G.EO. H. Geological Survey of Now Jersey. Annual report of the State Geologist for the year 1884, 1884, pp. 168, map and 4 pis.

DAWSON, GEOKGK M. Recent geological observations in the Canadian Northwest 

Territory. Science, vol. 3, 1884, pp. 647, 648.

FORD, S. W. On the age of the glazed and contorted slaty rocks iu the vicinity of 

Schodack Lauding, Rensselaer County, New York. Atn. Jour. Sci., 3d ser., 

vol. 28, 1H84, pp. 20(i-208.

 Note on the discovery of primordial fossils in the town of Stuyvesaut, Columhia Comity, New York. Am. Jour. Sci., 3d ser., vol. 28, 1884, pp. 35-37. 

HALL, JAMKS. Cryptozoon, n. g., Cryptozoon prolifermu, n. sp. 36th Ann. Rep.

State Mns. Nat. Hist, 1884, PI. vi. 

HITCHCOCK, C. H. Geological sections across Vermont and New Hampshire. Am.

Mus. Nat. Hist., Bull., vol. 1, 1884, pp. 155-179, plates 16-18. On thirteen

sections across Vermont and New Hampshire. Science, vol. 4, 1884, p. 327. 

Low, A. P. Explorations and Surveys in the interior of the Gaspe" Peninsula, 1HH3.

Geol. Survey Canada, 1882-3-4, 1884, pp. 21F. 

McCKEATii, ANDREW. TUB Iron Ores of tho Valley of Virginia. Am. lost. Mining

Eng. Trans., vol. 12, 1884, pp. 17-26. 

McCuTCiiKN, A. R. Northwest Georgia. (Geologic description.) Tenth Census U.

S., vol. 6; Report on Cotton Production in the United. States, pt. 2, 1884, pp.

285-295. 

MATTHEW, G. F. The geologic age of the Acadian fauna. The primitive Couocoryphean. British Assoc. Rep. 54th meeting, 1884, pp. 742,743. The geologic

age of the Acadian fauna. Geol. Mag., new ser., decade 3, vol. 1, 1884, pp.

470,471. 

ROGKHS, WM. B. A reprint of annual reports and other papers on the Geology of the

Virginias. New York, 1884, pp. xv, 832, with map and colored sections. 

SMITH, E. A. General description of the State of Alabama. Tenth Census U. S.,

vol. 6; Report on Cotton Production iu the United States, pt. 2, 1884, pp.

19-69 (bottom pagination), map. 

UPHAM, WAKKEN. The Geology of Minnesota. Vol. 1 of Final Report, 1884, pp.

404-532, 562-588, 632-647. 

WADSWOKTH, M. E. On the relation of the "Keweenawan Series" to tho Eastern

sandstone iu the vicinity of Torch Lake, Michigan. Boston Soc. Nat. Hist.,

Proc., vol. 23,1884, pp. 172-180. 

WALCOTT, C. D. Paleontology of the Eureka District. U. S. Geol. Surv. Monograph,

vol. 8, 1884, pp. 298.

 On the Cambrian faunas of North America; preliminary studios. U. S. Geol. 

Simoy Bull. No. 10; vol. 2, 1884, pp. 283-354. Separately paged, 1-74.

 Notes on Paleozoic rocks of Central Texas. Am. Jour. Sci., 3d aer., vol.'28, 

1884. pp. 431-433.

 Potsdam fauna at Saratoga, New York. Science, vol. 3, 1884, pp. 136, 137.

WIHTFIK.LU, R. P. Notice of some now species of Primordial fossils in the collections of the Museum and correction of previously described species. Am. 

Mus. Nat. Hist., Bull., vol. 1, 1884, pp. 139-154.

WHITNEY, J. D., and M. E. WADSWOKTH. Tho Azoic system and its proposed subdivisions. Harvard Mus. Com)). Zool.,Bnll., vol. 7, 1884, pp. 331-565.

WINCIIELL, N. H. Notes on the age of the rocks of the Mesabi and Vermilion iron 

districts. Geol. and Nat. ilist., Survey Minnesota, llth Ann. Rep. for 1883, 

1884, pp. 168-170.

 Tho geology of Minnesota. Vol. 1 of the Final Report, 1884, pp. 1-324,

347-366, 376-393, 533-561, 648-673. 

WOODWARD, HENRY. Notes on the remains of Trilobites from South Australia.

Geol. Magazine, u. ser., dec. in, vol. 1, 1884, pp. 342-344. 

WOOSTBU, L. C. Transition from the copper-bearing series to the Potsdam. Am.

Jour. Sci., 3d ser., vol. 27, 1884, pp. 463-465.
44 THE CAMBRIAN. [BULL. 81.

1885.

CAMPBELL, H. D. The Potsdam group east of the Blue Eidge at Balcony Falls, Virginia. Am. Jour. Sci., 3d ser., vol. 29, 1885, pp. 470-474.

CAMPBELL, J. L , and H. D. CAMPBELL. Review of William B. Rogers's Geology of 

the Virginias. Am. Jour. Sci., 3d ser., vol. 30. 1885, pp. 357-374; vol. 31, pp. 

193-202.

COOK, G. H. Contact phenomena with the Paleozoic rocks. Geol. Surv. of New 

Jersey. Ann. Rep. State Geologist for 1885. Trenton, 1885, pp. 53-55.

DANA, JAMES D. On Taconic rocks and stratigraphy, with a geological map of the 

Taconic region. Am. Jour. Sci., 3d ser., vol. 29, 1885, pp. 205-222, 437-443.

HALL, CHARLES E. Laurentiau magnetic iron-ore deposits from northern New 

York, accompanied by a geological map of Essex County. Report of the 

State Geologist for the year 1884. Albany, 1885, pp. 23-34 ; map op. p. 23.

HAYDEN, F. V. (Report of the Montana division.) U. S~ Geol. Survey, 6th Ann. 

Rep., 1884-'85, 1885, pp. 48-53.

HENDERSON, J. T. Geology [of Georgia]. The Commonwealth of Georgia. The 

Country; the People; the Productions. Atlanta, 1885, pp. 74-117.

HITCHCOCK, C. H. Geological map of Maine (with notes on geology of). In Geology of North England, 1885, pp. 4.

HYATT, ALPHEUS. Expedition to Newfoundland. Boston Soc. Nat. Hist., Proc., vol. 

23,1886, pp. 316-319. Cruise of the Arethusa. Science, vol. 6,1885, pp. 384-386.

IRVING, R. D. Preliminary paper on an investigation of the Archean formations of 

the Northwestern States. U. S. Geol. Survey, 5th Ann. Rep. 1883-84, 1885, 

pp. 175-242.

IRVING, R. D.., and T. C. CHAMBERLIN. Observations on the junction between the 

Eastern sandstone and the Keweeuaw series on Keweenaw Point, Lake Superior. U. S. Geol. Sur. Bull. No. 23, 1885, pp. 124.

LESLEY, J. P. A geological hand atlas of the sixty-seven counties of Pennsylvania, 

embodying the results of the field work of the survey from 1874 to 1884. 

2d Geol. Surv. Perm., X, 1885, pp. cxii.

MARCOU, JULES. The " Tacouic System " and its position in stratigraphic geology. 

Am. Acad. Proc., vol. 20, 1885, pp. 174-256.

MATTHEW, G. F. An outline of recent discoveries in the St. John group. New 

Brunswick Nat. Hist. Soc., Bull. No. 4, 1885, pp. 97-102.

 Illustrations of the fauna of the St. John group, continued; on the Conocoryphea, with further remarks on Paradoxides. Royal Soc. Canada, Traus. and

Proc., vol. 2, sec. iv, 1885, pp. 99-124. 

PERKINS, GEO. H. The Wiuooski or Wakefielcl marble of Vermont. Am. Naturalist,

vol. 19, 1885, pp. 128-136. 

UPHAM, WARREN. Notes on the geology of Minnehaha County. Dakota. Geol. and

Nat. Hist. Survey Minnesota, 13th Ann. Rep. for 1884, 1885, pp. 88-97. 

WALCOTT, C. D. Paleoutologic Notes. Am. Jour. Sci., 3d ser., vol. 29, 1885, pp.

114-117.

 Paleozoic notes; new genus of Cambrian trilobites, Mesonacis. Am. Jour.

Sci., 3d ser., vol. 28, 1885, pp. 328-331. 

WINCHTCLL, N. H. Fossils from the red quartzito at Pipestone. Geol. and Nat Hist.

Surv. Miun., 13th Ann. Rep. for 1884, 1885, pp. (55-72. 

WlNWOOD, H. H. Geological age of the Rocky Mountains. Geol. Magazine, new

ser., dec. in, vol.2, 1885, p. 240.

BEECIIER, C. E., and C. E. HALL. Field notes on the geology of the Mohawk Valley.

5th Ann. Rep. of Geologist of New York for 188.3, 1886, pp. 8-10, map. 

BROGGER, W. C. Om alderen af Oleuelluszonen i Nordarnerica. (On the age of the

Olenellus zone in North America.) Aftryck ur Geol. Foren. i Stockh. Forhan,

No. 101, Bd. 8,1886, pp. 182-213. 

DAWSON, GEO. M. Preliminary report on the physical and geological features of

that portion of the Rocky Mountains between latitudes 49° and 51° 30'.

Geol. Survey Canada, new ser., vol. 1, 1886, pp. 169B. 

DWIGHT, WILLIAM B. Discovery of fossiliferons Potsdam strata at Poughkkeepsie,

New York. Am. Assoc., Proc., vol. 34, 1886, pp. 204-209. 

 Recent explorations in the Wappinger Valley limestone of Dutchess County,

New York. No. 5: Discovery of fossiliferous Potsdam strata at Poughkeepsie,

New York. (Illustrated by map, Plate VI.) Am. Jour. Sci., 3d ser. vol. 31,

1886, pp. 125-133. Primordial Rocks of the Wappinger Valley Limestone.

Vassar Brothers Inst. Trans., vol. 4, 1887, pp. 130-141. 

EMMONS, S. F. Geology and mining industry of Leadville, Colorado. Monographs

of U. S. Geol. Survey, vol. 12, part 1, 1886, pp. 362.
WALCOTT.J LITERATURE. 45

Four>, S. W. Note on the age of the Swedish Paradoxides beds. Am. Jonr. Sci., 3d 

ser., vol. 32, 1886, pp. 473-476.

FRAZKK, PKKSIFOK. General notes. Sketch on tlie geology of York County, Pennsylvania. Am. Phil. Soc., Proc., vol. 23, 188l>, pp. 301-410.

HALL, JAMES. Note on some obscure organisms in the rooting slates of Washington 

County, New York. 29th Kept. State Mus. Nat. Hist. N. Y., 18815, p. 100."

HUNT, T. STEIIKY. The Taconic <{iiestion in geology. Mineral physiology and physiography. A second series of Chemical and Geological Essays. 1880, pp. 

517-686.

Low, A. P. Report of the Mistassini expedition, 1884-85. Geol. and Nat. Hist. 

Snrv. Canada, new ser.. vol. 1, 1886, pp. 33D.

MATTIUSW, G. F. Synopsis of the fauna in division 1 of the St. John group, Avith 

preliminary notes on the higher faunas of the same group. New Brunswick 

Nat. Hist. Soc., Bull. No. 5, 1886, pp. 25-31.

 The Cambrian faunas of Cape Breton and Newfoundland. (Abstract.) Canadian Record Sci., vol. 2, 1886, pp. 255-258.

 Illustrations of the fauna of the St. John group continued. No. JIL Descriptions of new genera and species (including a description of a now species 

of Solenopleura by J. F. Whiteaves). Trans. Roy. Soc. Canada, vol. 3, sec. 

iv, 1886, pp. 29-84. (Proc. for 1885.)

 Note on.the occurrence of Olcnellua (?) kjerulfi in America. Am. Jour. Sci., 

3d ser., vol. 31, 1886, pp.472, 473.

SMOCK, JOHN C. A geological reconnoissauce in the crystalline rock region, Dutchess, Pntnarn, and Westchester Counties, Now York. 39th Ann. Rep. State 

Mus. Nat. Hist., 1886, pp. 166-185.

WALCOTT, C. D. Classification of the Cambrian of North America. Am. Jour. Sci., 

3d ser., vol. 32, lb8G. pp. 138-157.

 Second contribution to the studies of the Cambrian faunas of North America. 

U. S. Geol. Survey Bull. No. 30; vol. 4, 1886, pp. 729-1095. (Separate paging, 

pp. 1-369.)

 Cambrian age of the roofing slates of Granville, Washington County, New 

York. Am. Assoc. Proc., vol. 35, 1887, pp.220, 2>l. (Separates issued 1886.)

WINCHELL, N. H. New species of fossils. 14th Aim. Rep. Minn. Geol. and Nat. Hist. 

Surv.1886, pp. 31.3-318.

 Revision of the stratigraphy of the Cambrian in Minnesota. Ibid, pp. 325-337.

1887.

AMI, H., and T. W. E. SOWTER. Report of the geological branch [of Ottawa Field 

Naturalists' Club.] Ottawa Naturalist, vol. 1, 1887, pp. 93-97.

DANA, JAMES D. On Taconic rocks and stratigraphy, with a geological map of the 

Taconic regions. Part 2: the Middle and Northern part. Am. Jour. Sci., 

3d ser., vol. 33, 1887, pp. 270-276, 392-419, pi. 11. (Continued from vol. 29, 

18*5, p. 443.)

DAWSON, G. M. On certain borings in Manitoba and the Northwest Territory. Royal 

Soc. Canada, Proc. and Trans., vol. 4, section iv, 1887, pp. 85-99.

[DAWSON, G. M.] [Notes on exploration in the Yukon district.] Science, vol. 10, 

1887, pp. 165, 166.

D WIGHT, WILLIAM B. Primordial rocks of the Wappiuger Valley limestones and 

associated strata. Vassar Brothers lust., Trans., vol. 4, 1887, pp. 206-214. 

Discovery of additional Potsdam and pre-Potsdam strata of the Olencllus 

group near Poughkeepsio, New York. Ani. Jour. Sci., 3d ser., vol. 34, 1887, 

pp. 27-32.

ELLS, R. W. Report on the geology of a portion of the eastern townships of Quebec. Geol. Sur. Canada, 1886, new ser., vol 2, 1887, pp. 1 J-70J.

McCONNicLL, R. G. Report on the geological structure of a portion of the Rocky 

Mountains, with a section. Geol. Surv. Canada, 1886, new ser., vol. 2, 1887, 

pp. 1D-41D.

MATTHEW, G. F. Illustrations of the faunas of the St. John group. No. 4. Canadian Rec. Sci., vol. 2, 1887, pp. 357-363, 432. (Abstract.)

 On the Cambrian faunas of Cape Breton and Newfoundland. Royal Soc. Canada, Proc. and Trans., vol. 4, section iv, 1887, pp. 147-157.

 On the kin of the Paradoxides (Olenellus?) kjerulli. Am. Jour. Sci., 3d ser.,

vol. 33, 1887, pp. 390-392. 

ROMINGER, C. Description of Primordial fossils from Mount Stephens, Northwest

Territory of Canada. Philadelphia Acad. Sci., Proc. 1887, pp. 12-19. 

STEVKXSON, JOHN J. A geological reconuoissance of Bland, Giles, Wythe, and port ions of Pulaski and Montgomery Counties of Virginia. Am. Philos. Soc.

Proc., vol. 24. 1887, pp. 61-108. 

WALCOTT, CHAKLKS D. Fauna of the "Upper Taconic" of Einmous, in Washington

County, Now York. Am, Jour. Sci., 3d ser., vol. 34,1887, pp. 187-199,
46 THE CAMBRIAN. IBULL.SI.

1888.

BERGERON, JULES. Note snr la presence de la Faune primordialo (Paradoxidien) 

dans les environs de Ferrals-des-Moutagnes (He'rault). - Bull. Soc. ge"ol. 

France, 3° s6r., vol. 16, 1H88, pp. 282-285.

CALVIN, S. Notes on the formations passed through in boring the deep well at 

Washington, Iowa. American Geologist, vol. 1, 1888, pp. 28-31.

CARPENTER, F. R. Notes on the geology of the Black Hills. Preliminary Eep. Dakota School of Minos, on the Black Hills of Dakota, 188d, pp. 11-52.

DAWSON, J. W. On the Eozoic and Paleozoic rocks of the Atlantic coast of Canada 

in comparison with those of western Europe and the interior of America. 

Quar. Jour. Geol. Soc. London, vol. 44, 1888, pp. 797-817. Canadian Eecord 

of Science, vol. 3, 1888, pp. 182, 183, 230, 231.

HAYDEN, F. V. Report of Montana division of geology. U. § Geol. Survey. 7th 

Ann. Rep., for 1885-'86, 1888, pp. 85-87.

HITCHCOCK, C. H. Date of the publication of the report upon the geology of Vermont. Boston Soc. Nat. Hist., Proc., 'vol. 24, 1888, pp. 33-37.

IRVING, R. D. On the classification of the early Cambrian and pre-Camhriau formations. U. S. Geol. Survey, 7th Ann. Rep. for 1885-'86, 1888, pp. 365-454.

MARCOU, JULES. American Geological Classification and Nomenclature. Cambridge, 

1888, pp. 75.

 The Taconic of Georgia and the report on the geology of Vermont. Memoirs

Boston Soc. Nat. Hist., vol. 4, 1888, pp. 105-131. 

MATTIIEW, G. F. On a basal series of Cambrian rocks in Acadia. Canadian Record

Science, vol. 3, 1888, pp. 21-29.

 On the classification of the Cambrian rocks of Acadia. Canadian Record 

Science, vol. 3,1888, pp. 71-81.

 Illustrations of the fauna of the St. John group, No. IV. Part 1. Description of a new species of Paradoxides (Paradoxides regina). Part 2. The 

smaller trilobites with eyes (Ptychoparidfe and Ellipsocephalidte). Royal 

Soc. Canada, Trans., vol. 5, sec. iv, 1888, pp. 115-166.

SIIALER, N. S. On the geology of the Cambrian district of Bristol Connty, Massachusetts. Bull. Mus. Cornp. Zoo'1. Harvard College, vol. 16, 1888, pp. 13-26, 

map.

SHALER, N. S.. and A. F. FOERSTE. Preliminary descriptions of North Attleborough 

fossils. Bull. Mus. Cornp. Zool. Cambridge, vol. 16, 1888, pp. 27-41.

UPIIAM, WARREN. The geology of Minnesota. Vol. 2 of final report, 1888, pp. 102- 

263, 309-425, 612-645.

WALCOTT, C. D. Discovery of fossils in the lower Tacouic of Emmous. Am. Assoc. 

Proc., vol. 36, 1888, pp. 212, 213.

 The Taconic system of Emmous and the use of the name Tacouic in geologic 

nomenclature. Am. Jour. Sci., 3d ser. vol. 35, 1888, pp. 229-242, 307-327, 

394-401.

 Cambrian Fossils from Mount Stephens, Northwest. Territory of Canada. 

Am. Jour. Sci., 3d «er.,vol. 36,4888, pp. 161-166.

 The stratigraphical succession of the Cambrian faunas of North America.

Nature, vol. 38, 1888, p. 551. 

WILLIAMS, H. S. Report of the subcommittee on the Upper Paleozoic (Devonic).

International Congress of Geologists, American Committee. Report to the

session of the congress held in London, September 17, 1888, pp, 1-31C. 

WINCHELL, N. H. The Geology of Minnesota. Vol. 2, of final report, 1888, pp. 1-

101, 264-398.

 A great Primordial quartzite. Am. Geologist, vol. 1, 1888, pp. 173-178.

1889.

BROADHEATJ, G. C. The geological history of the Ozark uplift. American Geologist,

vol. 3, 1889, pp. 6-13. 

CROSBY, W. O. Physical history of the Boston Basin. Lowell Free Lectures, 1889-'90.

Boston, 1889, pp. 22.

DWIGHT, W. B. Recent explorations in the Wappinger limestones and other forma- 

. tions of Dutchess County, New York. Am. Jour. Sci., 3d ser., vol. 38, 1889,

pp. 139-153. 

ELLS, R. W. Second report on the geology of a portion of the Province of Quebec.

Geol. Sur. Canada, vol. 3, new ser., 1889, pp. 1K-120K. 

FOERSTE, A. F. The paleontological horizon of the limestone at Nahaut, Mass.,

Boston Soc. Nat. Hist., Proc., vol. 24, 1889, pp. 261-263. 

KING, WILLIAM. Note on the discovery of Trilobites by Dr. H. Wsirfch in the Neobolus beds of the Salt Range, Records of the Geol. Sur. of India, vol. 22.

1889, pp. 153-157.
WAI.COTT.I LITERATURE. 47

LANK, ALFRED C. The geology of Nahant. Boston Society Nat. Hist., Pfoc., vol.

2J, 1889, pp. 91-95. 

MATTHEW, 0. F. How is the Cambrian divided? A plea for the classification of

Salterand Hicks. Am. Geologist, vol. 4, 1889, pp. 139-148.

 . On the classification of the Cambrian rocks in Acadia. Supplementary 

note. Canadian Record Science, vol. 3, 1889, pp. 303-31f>, 371, 372.

 . On the Cambrian organisms in Acadia. Canadian Rec. Sci., vol. 3,1889, pp.

383-387. 

McG'ONNKLL, R. G. Notes on the geology of Mount Stephen, British Columbia.

American Geologist, vol. 3, 1889, pp. 22-25. 

MEADS, A. D. The Stillwater deep well. American Geologist, vol. 3, 1889, pp. 342,

343.

NICUOLSON, H. A., and R. LYDKKKEK. A manual of paleontology for the use of students with a general introduction on the principles of paleontology. 3d

edition, 2 vols. Edinburgh and London, 188'J. 

RAND, T. D. A discussion on the rocks of Pennsylvania and New York. New York

Acad. Sci. Trans., vol. 8, 1889, pp. 47-51. 

SHALER, N. S. The geology of the island of Mount Desert, Maine. 8th Ann. Rop.

U. S. Geol. Survey," part 2, 1889, pp. 987-1061. 

WALCOTT, C. D. Stratigraphic position of the Oleuellus faunain North America and

Europe. Am. Jour. Sci., 3d ser., vol. 37, pp. 374-392; vol. 38, IB89, pp. 29-42.

 . Descriptive notes of new genera and species of the Lower Cambrian or 

Olenellus zone of North America. U. S. National Museum, Proc., vol. 12, 

1889, pp. 33-40.

 . Descriptions of new genera and species of fossilsfrom thoMiddle Cambrian.

U. S. National Museum, Proc., vol. 11, 1889, pp. 441-446. 

WINCHELL, N. H. The crystalline rocks of Minnesota. General report of progress

made ill the study of their field relations. Statement of problems yet to be

solved. Geol. and Nat. Hist. Survey of Miuu. 17th Ann. Rop. for 1888,1889,

pp. 5-74.

1890.

COMSTOCK, THEO. B. A preliminary report on the geology of the central mineral 

region of Texas. 1st Ann. Rep. Geol. Surv. of Texas for 1889, 1890, pp. 

239-391.

DANA, J. D. Sodgwick and Murchison ; Cambrian and Silurian. Am. Jour. Sci., 

3d ser., vol. 39, 1890, pp. 167-180.

 -. Areas of coutiuental progress in North America and the influence of the conditions of these areas on the work carried forward within them. Geol. Soc. 

America, Bull., vol. 1, 1890, pp. 36-48.

ETIIERIDGE, R., jr. On some Australian species of the family Arcluaocyathinaj. 

Trans. Roy. Soc. South Australia, vol. 13, 1H90, pp. Id-22.

GILBERT, G. K. Lake Bounevillo. Monographs U. S. Geol. Survey, vol. 1, 1890, pp. 

438.

HITCHCOCK, C. H. Maine, New Hampshire, Vermont, Rhode Island, and Connecticut. (Geological formations.) Macf'urlaue's Am. Geol. R. R. Guide, 2ded., 

1890, p. 86.

MATTHEW, G. F. On Cambrian organisms in Acadia. Roy. Soc. Canada Trans., vol. 

7, Proc., sec. iv, 1890, pp. 135-162.

McGEE, W J. The southern extension of the Appoijiattox formation. Am. Jour. 

Sci., 3d ser., vol. 40, 1890, pp. 15-41.

PEALE, A. C. Report of Dr. A. C. Pealo (on the Montana division of geology). U. 

S. Geol. Surv., 10th Ann. Rep., 1890, pp. 130-132.

SEARS, JOHN H. The stratified rocks of Essex County (Massachusetts). Essex Institute, Bull., vol. 22, 1890, pp. 31-47 (separate, pp. 17).

WALCOTT, C. D. A review of Dr. R. W. Ella's second report on the geology of a 

portion of the province of Quebec; with additional notes on the " Quebec 

group." Am. Jour. Sci., 3d ser., vol. 39, 1890, pp. 101-115.

 Description of new forms of Upper Cambrian fossils. U. S. National Museum, 

Proc., vol. 13, 1890, pp. 267-279.

 The fauna of the Lower Cambrian or Olenellus zone. 10th Ann. Rept. U. S.

Geological Survey, Part i, 1890, pp. 509-763, pis. 49-98. 

WINCHKLL, N. H., and H. V. WINCHELL. The Tacouic iron ores of Minnesota and

ot western New England. Am. Geologist, Arol. 6, 1890, pp. 263-274.

1891. '

GniGER, H. R., and ARTHUR KEITH. The structure of the Blue Ridge near Harper's 

Ferry. Bull. Geol. Soc. America, vol. 2, 1891, pp. 155-164.

HAYES, C. WILLARD. The overthrust faults of the southern Appalachians, Bull. 

Geol. Soc. America, Vol. 2, February, 1891, pp. 141-154,
48 THE CAMBRIAN. [BULL. 81.

MATTHEW, G. F. Illustrations of the fauna of the St. John group No. 5. Roy. Soc. of 

Canada Trans., vol. 8, sec. iv, 1891, pp. 123-166.

NASON, FKANK L. The Poat-Archean age of the white limestones of Sussex County, 

New Jersey. Am. Geologist, vol. 7, 1891, pp. 241-252.

SHALKH, N. S., and H. 'S. WILLIAMS. On the geology of Little Falls, Now York. 

Bull. Geol. Soc. America, vol. 2, 1891, pp.

SMITH, EUGENE A. Geological structure and description of the valley regions adjacent 

to the Cahaha Coal Fields. Geol. Survey of Alahania. Report on the Cahaba 

Coal Fields, by Joseph Squire. Ft. 11, 1890 (issued March, 1891), pp. 133-180.

WOLFF, J. E. On the Lower Cumbrian age of the Stockbridge limestone at Rutland, Vermont. Bull. Geol. Soc. America, vol. 2,1891, pp. 331-337.
CHAPTER II.

HISTORICAL REVIEW OF THE GEOLOGIC AND PALEONTOLOGIC

WORK.

The scope of this review is limited, with a few exceptions, to the notice of papers and memoirs that have added something original to the 

preexisteut knowledge of the rocks and faunas now referred to the 

Cambrian group.

Several methods of presenting the historical data have suggested 

themselves.

(1) Chronologic; (2) Geographic and chronologic; (3) Chronologic, 

geographic, and stratigraphic.

(1) Chronologic. This method necessitates reference to papers in the 

order of their publication, whether they treat of Cambrian rocks in 

Newfoundland, New York, Alabama, or Nevada. All is subservient to 

the chronologic record.

(2) Ocographic and chronologic. This method permits of tne chronologic grouping of the papers referring to the rocks under consideration 

in geographic areas.

(3) Chronologic, geographic, and stratigrapMc. This third and more 

comprehensive method arranges the review in the form of a statement 

of the historical data as in the second method, with the addition of 

treating of such primary divisions separately as may be thought worthy 

of such consideration. To this there may also be added, in exceptional 

instances, the chronologic arrangement of the discoveries and opinions 

of some of the more prominent investigators and authors.

The second method is adopted in this review in connection with the 

third, where the latter is necessary in order to present more clearly the 

evolution of the present knowledge of the rocks and fauna of the Cambrian group.

The Cambrian group can usually be divided into three primary divisions. 

First, the Lower Cambrian; second, Middle Cambrian; third, Upper 

Cambrian. This nomenclature will be used throughout the review, 

when it is necessary to refer to a standard generally known.

Kocks of Cambrian age occur on the North American continent in 

lour principal geographic areas or geologic provinces. In reviewing 

the literature it is possible, owing to the investigators in each province 

having limited their work to their respective provinces, to present the 

history of discovery and publication in each by itself, as follows:

I. The Atlantic Coaat or Eastern Border Province.

II. The Appalachain Chain. 

ILL The Rocky Mountain or Western Border Province,

Bull, 81- 4 40
50 THE CAMBRIAN. [BULL. 81.

IV. The Interior Continental or Central Province. 

The record of paleoutologic investigation in each province will follow the geologic review.

ATLANTIC COAST PEOVINCE.

The Atlantic coast province includes the deposits on the island of 

Newfoundland, the provinces of Nova Scotia and New Brunswick and 

Cape Breton, and the States of Maine, New Hampshire, and eastern 

Massachusetts.

NEWFOUNDLAND.

Systematic geologic investigation in Newfoundland began with Prof. 

J. Beete Jukes, who in 1S431 published a report of his studies in field 

and office. He describes the relation of the strata at the base of the 

Paleozoic section (now referred to the Olenellus zone), to the unconformably subjacent crystalline rocks about Conception Bay, and mentions the red shales in which the Olenellus fauna is now known to 

occur, as well as the green and dark shales of the Paradoxides zone, as 

subsequently known. A description is given of the upper slate formation as shown on the islands in the bay, under the name of Bell 

Island shale and grits; and of the lower slate under the name of StJohn's slate, 2,000 to 3,000 feet thick, as seen near the town of St. 

John's; also the superjaceut Signal Hill sandstone, about 800 feet thick.2 

In the absence of fossils no attempt was made to correlate the formations with those of England. On the map accompanying the report 

the geographic distribution is given of the lower slate (St. John's) and 

of the upper slate (Bell Island) formations about Conception Bay and 

Smith Sound.

Two years later Capt. H. W. Bayfield3 described6 a sandstone with 

subjacent red and white limestone on the Straits of Belle Isle, which 

he stated contained a species of Cyathophyllum. This is the first notice 

of the Lower Cambrian rocks containing Arcbneocyathus, and it is the 

second recorded discovery of fossils now referred to the Oleuellus zone.

At a meeting of the Boston Society of Natural History, April 20,1859, 

Dr. 0. T. Jackson exhibited a trilobtte from the calcareous slate of St. 

Mary's Bay, Newfoundland, which he thought identical with Paradoxides liarlani from Braiutree, Massachusetts. He said that this formation could be followed, though in an interrupted line, from Braiutree 

to Newfoundland.4

In 1859 Mr. J. W. Salter 5 received a specimen of the genus Paradox1 General report of the geological survey of Newfoundland in 1839 and 1840, pp. 160, 2.pls., London, 

1843. 

S 0p.cit.pp. 55-60.

3 Ou the junction Of thO transition and primary rocka of Canada and Labrador. Quart. Jour. Geol. 

Soc., London, vol. 1, 1845, pp.45U-459.

4 On a trilobite from Braintroe. Boston Soc. Nat. Hist., Proc., vol. 7, 1859, p. 54. 

* On the fossils of the Lingula-nags or "Zoue Primordialo." Quart. Jour. Geol. Soc., London, vol. 

15, 1859, pp. 551-555.
NEWFOUNDLAND. 51

ides, collected from the upper slate of St. Mary's Bay, Newfoundland, 

which he described under the name of Paradoxides lennctti, calling 

attention to its relation to Paradoxides spinosus and P. bohemicus, of 

Bohemia.

In 1862, Prof. Jukes, referring to his work in Newfoundland, stated 

that he included under the upper slate formation the Bell Isle shale 

and gritstone and variegated slate; and in the lower slate formation the 

Signal Hill sandstones and St. John's slate. He says he did not find 

any fossils in them, but that Mr. C. Bennett subsequently found trilobites of the genus Paradoxides (named P. lennetti by Mr. J. W. Salter) 

in the slates on the west side of St. Mary's Bay. u These slates belong 

to the group I called the St. John's slate, which is covered conformably 

by the Signal Hill sandstone. The Variegated slate group, on the other 

hand, passes up into the Bell Isle shale and gritstone, and near Brigus 

Harbor, in Conception Bay, may be seen to rest unconformably on the 

St. John's slate" (as described in 1843). l This is the unconformity 

now recognized between the Cambrian and Algonkian rocks.

Eighteen years after Captain Bayfield had reported on the strata of 

the north side of the straits of Belle Isle, Sir William E. Logan 2 described the strata resting on the gneiss as red and green sandstones, 231 

feet thick, overlain by gray, reddish, and greenish limestone. In the limestone a number of fossils were found which Mr. Billings identified with 

those found in the " lied Sandrock " of Vermont. The formation was referred to the Lower Potsdam by Logan. Fifteen miles across the straits, 

on the Newfoundland coast, the rocks are apparently of Calciferous age; 

and he concluded that the Potsdam sandstone zone was buried beneath 

the waters of the Straits.3 Lu the description of the section at Bonne 

Bay, on the west coast of Newfoundland,4 it is compared with that at 

the Straits of Belle Isle; and on pages SG5-8G7, the section at Bonne 

Bay is given in detail. Of this 1,711 feet are, by the contained fossils, 

referred to the Potsdam group.

In the report of the Geological Survey of Newfoundland for 18G45 a 

summary is given of thetheu existing view of thesncccssion of the Lower 

Paleozoic rocks in North America. For Newfoundland the succession 

of the rocks now referred to the Cambrian is Upper Potsdam, Lower 

Potsdam, and St. John's group, and Newfoundland is cited as the locality where the lower portion of the series is complete. The lowest, or 

St. John's group, is correlated with that of St. John, New Brunswick, 

and the Paradoxides beds of Braintree, Massachusetts. The lower 

Potsdam is represented by several hundred feet of limestones and

1 The student's manual of geology. Second edition. Edinburgh, 1862, p. 457.

'Geological survey of Canada, lleport of progress from its commencement to 1803. Montreal, 1863, 

pp. 983,11 plates. Atlas of maps and sections, with an introduction and appendix. Montreal, 1865. 9 

maps and sections.

8 Op. cit., p. 288.

* Op. cit., p. 293.

8 Lopan, W. E,, Lower Silurian Rocks of North America. Geol. Snrv. Newfoundland, Hep. Prog, for 

1864, Montreal, 1866, pp. 45,46. Revised edition, 1881, p. 49.
52 THE CAMBKIAN. [BULL. 81.

sandstones on the Straits of Belle Isle, and on White Bay, Newfoundland, and by the slates of St. Albans and Georgia, Vermont. The Upper Potsdam is that of Wisconsin and Minnesota, represented in the 

typical Potsdam of New York. This horizon is not recognized in the 

northern part of Newfoundland, but occurs on Conception Bay, in the 

southeastern part. The tabulation made by Logan has been followed 

very largely by all writers upon American geology, and the succession 

was not changed until 1888, when it was discovered that the St. John 

group of Mr. G-. F. Matthew was above the Lower Potsdam of Billings 

and Logan.

The Geological Survey of Newfoundland, under the direction of Dr. 

Alexander Murray, added materially to our knowledge of the Lower 

Paleozoic rocks. All the strata beneath the Calciferous or Quebec 

group were referred to the Potsdam group. 1 Ill the neighborhood of 

Canada Bay, on the east coast, the entire series referred to the Potsdam 

has a thickness of 1,153 feet, of which the lower 7CO feet belong to the 

Lower Cambrian zone, as shown by Olenellus vennontana occurring in 

the upper portion.2 In the report of field work for 1808, Dr. Murray3 describes the rocks about Conception Bay, in the southeastern 

portion of the island. Of the lowest bed exposed on Manuel's Brook, a 

small stream that flows into Conception Bay, he says : " On Mauuel's 

Brook a very coarse conglomerate may be seen, in strong and moderately regular beds, resting directly upon the syenitic gneiss of the 

valley above. * * * About 400 yards below the bridge the conglomerate is overlaid conformably by a set of dark brown or blackish 

shales, * * * with some hard calcareous beds interstratitied," and this 

series extends down the stream nearly to the bay.4 Dr. Murray also 

describes, in a section at Topsail Head, a gray compact limestone in 

strong solid beds, 1 to 2 feet thick, showing a vertical thickness of 

about 100 feet, together with soineiuterstratitied shale. The limestone 

is subjacent to a dark brown, linely laminated shale. Detailed sections 

are given of the shales and sandstones exposed on Kelly's and Great 

Bell Islands, Conception Bay; the former has a tbickuess of 712 feet 

and the latter of 476 feet. A summary of the rocks referred to the 

Lower Silurian gives an en tire thickness of 3,880 feet.5 Figures of five 

sections accompany the text, in which the unconformity between the 

Lower Silurian rocks and the subjacent intermediate system or Hurouian and the Archeau is well shown. The subjacent slates and Signal 

Hill sandstones of Jukes are referred by Dr. Murray to the Cambrian 

group on account of fossils having been found there, which Mr. Billings described as Aspidella terra-novica and Areuicolites.6

1 Sequence and distribution of the rocks of the great Northern Peninsula. Geol. Surv. Newfoundland, Rep. Prog, for 18G4, Montreal, 1866, pp. 10,44. Koviscd edition, 1881, pp. 5-47.

2 Op. cit., p. 10.

8 Of the sequence and distribution of the formations. Report upon the geological survey of Newfoundland for 1868, St. John's, 1808, p. 68. Revised edition, 1881, pp. 154-107. 

4 Op. cit., p. 154. 

"Op. cit.,pp.l57-lCO. 

* Op. cit., p. 144.
WAMJOTT.I NKWFOTTNDLAND. 53

In the report for 1809 a description is given of the Lower Paleozoic 

rocks studied by Mr. Howley as they occur on Trinity Bay and St. 

Mary's Bay. 1 The variegated slates of Jukes are described as containing Paradoxides and the superjaceut argillaceous shales and sandstones 

carry Cruziaua and other fossils. These last represent the rocks of the 

Bell Islands in Conception Bay. In the report for 3870 2 a summary is 

given of the then existing knowledge of the Primordial formations in 

southeast Newfoundland. In descending order the upper formation is a 

brown and black micaceous shale with the gray micaceous sandstones 

of Great Bell Isle, Conception Bay. The organic contents are: Two 

species of Lingula, four species of Palseophycus, Eophyton linnceanum of 

Torrell, another Eophyton and Grusiana semiplicata Salter. Thickness, 

476 feet. He says that the slates of Little Bell Isle and the beds of 

shale beneath the water are considered to have a thickness of 1,426 

feet, to which the Kelly's Island sandstone and shale are to be added, 

with a thickness of 720 feet. [As now known this forms the upper 

division of the Cambrian.] Beneath this he describes the black slates, 

with Paradoxides bennetti, having a thickness of 150 feet. On St. 

Mary's Bay this division, united with the red, green, and black shales 

or slates, in which Paradoxides bennetti, Conocephalites grefjarius and 

other fossils were recognized, has a thickness of 1,045 feet. [This forms 

the middle division of the Cambrian as now known.] Below this the 

hard thick beds of gray and reddish limestone of Topsail Head, Brigus 

South Head, Conception Bay, and the Little Salmonier Eiver of St. 

Mary's Bay are united witli various outcrops of red, green, and blackish 

argillaceous slates and a series of sandstones below. [These form the 

lower division of the Cambrian as now known.] The total thickness 

of the section described is 5,972 feet.3 Several sections are illustrated 

to show the relation of the Primordial-Silurian to the subjacent rocks.

In the report for 1872 the Primordial-Silurian rocks are described as 

they are exposed on Trinity Bay, etc., by Dr. Murray.4 He states that 

on paleontological grounds Mr. Billings is disposed to draw a marked 

distinction between the upper strata of the section of 1870 and the 

lower members of that section, in consequence of an apparent hiatus or 

break in organic development between the Paradoxides beds and the 

fossiliferous strata of Great Bell Island in the Conception Bay section. 

The lower measures he [Billings] appears to regard as the equivalent of 

the lower Lingula flags of Great Britain, or the Meuevian group of 

Salter and Hicks; while the upper parts contain forms in some degree 

typical of the horizon of the Upper Potsdam.5 This is followed by a

'Murray, Alexander. Of the rocks and associated minerals [of Bonavista Bay, etc.]. Report 

upon the geological survey of Newfoundland for I860. Kovisod edition. 1881, pp. 200-203.

* Murray, Alexander. Of Primordial, Silurian, and related formations. Geol. Snrv. Newfoundland for 

1870, St. John's, 1870, pp. 30-43. Revised edition, 1881, pp. 232-241. 

S 0p. cit., pp. 237-230.

 Distribution of the formations [of Avalon]. Report upon Gool. Surv. of Newfoundland for 1872. 

St. John's, 1873, pp. 14-34. Revised edition. London, 1881, pp. 285-297. 

"Op. nit ,p 201.
54 THE CAMBRIAN. IBULL.IH.

list of the species described by Mr. Billings from the Paradoxides zone 

and the strata of Great Bell Island.

Prof. John Milne traveled extensively along the coast of Newfoundland, and published the results of his geologic studies in association 

with the " Notes on Geology " by Alexander Murray.1 The PrimordialSilurian is spoken of as a separate division; then, superjacent to the 

rocks of this formation, conie the Potsdam and Calciferous. There 

does not appear to be any additional data to that already given in the 

report on the geology of Newfoundland by Dr. Murray.

When describing some fossils collected by Mr. T. G. Weston, of the 

Canadian Geological Survey, in 1874, from St. Mary's, Trinity, and Conception Bays, Newfoundland, Prof. J. F. Whitcaves states that tbe 

paleontological evidence sustains the view of Sir W. E. Logan that the 

slates of St. John's, Newfoundland, probably belong to tbe same horizon 

as the Acadian or St. John group of St. JoliD, New Brunswick. 2 Of 

the deposits on the islands of Conception Bay he says:. u From Mr. 

Murray's report already quoted it would appear that the shales of Kelly's Island are not quite so old as those of Manuel's Brook, but that 

they are older than the Menevian sandstones of Great Bell Island." 3

Dr. Murray appears to have considered the Potsdam zone as above 

the Primordial beds of Newfoundland. This is shown in the chapter 

on the "Geology of Newfoundland," where a summary of the geology 

is presented as taken from Dr. Murray's work.4

Prof. Alpheus Hyatt, in his expedition to Newfoundland, visited the 

north coast of the Straits of Belle Isle, and collections were made at 

Anse au Loup and Amour Cove from the " so-called Potsdam sandstones 

and limestones of the Canadian survey. The observations made at these 

points indicate a fauna quite distinct from those of anjr of the limestones 

or slates of the west coast of Newfoundland. The absence of Cephalopoda and the prevalence of primitive forms of Archfeocyathus show 

the rocks to be probably older than those of the Quebec group at Port 

au Choix and other localities. The primitive sponges, or Archceocyathi, 

have here replaced corals completely, and may be described as reefbuilders, since numerous hummocks and masses and parts of the strata 

are formed entirely of their remains. Immediately below these limestones, and conformable with them, lie the red sandstones, several 

layers of which are perforated with Scolithus burrows." 5

A brief summary of the Lower Cambrian rocks of Newfoundland, 

was given by Mr. C. D. Walcott, in a study of the Cambrian faunas of

1 On tbe rocks of Newfoundland. Gcol. Mag., new ser., decade II, vol. 4,1877, pp. 251-202.

2 On some Primordial fossils from southeastern Newfoundland. Am. Jour. Sci., 3d sor., vol. 10,1878, 

p. 225.

3 0p.cit., p.226.

4 Hatton, Joseph, andM. Harvey. Geologyof Newfoundland. Newfoundland, the oldest British colony, 

its history, its present condition, and its prospects in the future. London,4883, pp. 178-187. American 

edition, Boston, 1883, pp.150-157.

Expedition to Newfoundland. Boston Soc. Nat. Hist. Proc., vol. 23, 1880, p.319. Cruise of the 

Arethusa. Science, vol. 0,1885, p. 386.
WAtcoTT.1 NEWFOUNDLAND. 55

North America1 when discussing the stratigraphic position of the Olenellus fauna. In it he says2 that the only locality known where the two 

faunas occur in the same geographic area is on Conception Bay, Newfoundland; and special stress is placed on the occurrence at Topsail 

Head of several species of fossils typical of the Olenellus zone at the 

Straits of Belle Isle. This fauna was referred to the Middle Cambrian,3 

although Dr. Murray states in his section of 1868 that Mr. Billings referred the species to the Potsdam.4 By this Mr. Billings probably 

meant his lower Potsdam, which is now (1890) included in the Lower 

Cambrian.

In an abstract of a paper on the Cambrian faunas of Cape Breton 

and Newfoundland, published in advance of the paper read before the 

Royal Society of Canada, Mr. G. F. Matthew5 classifies the horizons of 

the Cambrian as follows:

(1) The horizon of Paradoxides Jcjerulfi.

(2) The horizon of the Couocoryphees.

(3) The horizon of Paradoxides tessini.

(4) The horizon of Paradoxides spinosns.

(5) The horizon of Paradoxides davidis.

It is stated6 that "in this classification of the various Newfoundland 

horizons in the Paradoxides zone Mr. Matthew has placed that of Paradoxides Igerulfi first or oldest, because that is its position in Scandinavia." In the final paper7 he speaks of the fossils found at Topsail 

Head, and Brigus on Conception Bay, mentioning Agraulos stremms, 

Iphidea (allied to Iphidea bclla Billings), and Stenotlieca paupera Billings. He says these fossils do not give sufficiently firm indications to 

make it clear that they are older than some other horizons mentioned 

hereafter. He then describes the fossils of the Paradoxides zone. A 

new species, Solenopleura bombifrons, is described from the limestone of 

Topsail Head.8

In the summer of 1888 Mr. C. D. Walcott made a careful study of the 

Cambrian section in Newfoundland, and determined the Olenellus zone 

to be beneath the Paradoxides zone, and not above it, as arranged by 

Logan in his. scheme of 1864. A detailed section of the Cambrian 

strata on Conception Bay was published, with lists of the fossils 

occurring at the different horizons in it.9

'Second contribution to the studies on the Cambrian faunas of North America. "U. S. Gool. Surv., 

Bull. No. 30, vol. 4,1880.

* Op. cit, p. 49.

* Op. cit., p. 29.

4 0f the sequence and distribution of the formations. Report upon the geological survey of Newfoundland for 1808. Revised edition, 1881, " P. 1" of section, p. 157.

0 The Cambrian faunas of Cape Breton and Newfoundland (abstract). Can. Record Sci., vol. 2,1880, 

pp. 255-258.

°0p. cit, p. 258.

7 On the Cambrian faunas of Cape Breton and Newfoundland. Royal Soc. Canada, Proc. and Trans., 

vol.4, section iv, 1887, pp. 147-157.

» Op. cit., p. 156.

9 The stratigraphical succession of the Cambrian faunas of North America. Nature, vol. 38,1888, 

p. 551. Stratigraphic position of the Olonollns fauna in North America and Europe. Am. Jour. 

Sci., 3d ser., vol. 37.1889, pp. 374-392 ; vol. 38,1889, pp. 29-42.
56 THE CAMBRIAN. [BULL. 81.

NOVA SCOTIA.

The altered or metamorphic slate belt of the Atlantic coast of Nova 

Scotia is represented on an early geological map by Dr. Aoraham Gesner 1 as extending from Cape Canso to Cape Sable. He states that the 

area is within the primary district and composed principally of granite, 

gneiss, and mica slate. A general description of the rocks is given in 

the account of the local geology of the townships in which they occur.

At a meeting of the Geological Society of London on May 10, 1843, 

Dr. Gesner 2 presented to the society a geological map of Nova Scotia, 

accompanied by a memoir on the geology. In the text 3 the lowermost 

of the Silurian rocks devoid of animal remains is referred to the Cambrian. The map was not published with his paper. It appeared in 

1845 4 in connection with papers by Mr. Kichard Brown, on the geology 

of Cape Breton, and Mr. J. W. Dawsou, on the Lower Carboniferous 

rocks or gypsiferous formation of Nova Scotia. The strata now provisionally included in the Cambrian group are indicated on the map 

as micaceous and chloritic slates, clay slate, quartz rock, and gray wacke 

slate. They extend entirely around the central area of granite and 

syenite, and are separated from the Atlantic coast by a broad belt of 

color designated as granite. At a later date Gesner described the stratified non-fossiliferous rocks or Cambrian group of Nova Scotia 5 as an 

extended belt of hornblende slate, chlorite slate, clay slate, graywacke 

slate, and quartzite, succeeding the granite and its associates, and with 

them occupying almost the whole of the Atlantic side of the province. 

No fossil remains have been found in any of these metamorphic masses.

In 1850 Dr. J. W. Dawson described the Atlantic coast series as follows:

The prevailing stratified rocks in this group are compact and flaggy gray quartzite (often weathering white), mica slate, and clay slate, the latter usually of dark 

colors, and occasionally passing into flinty slate and qnarfczite. " * *

The hypogene rocks associated with them are white and flosh-colored granite, 

which has penetrated the raetamorphic rocks in large irregular bauds and masses.6

As a result of his study of this group of rocks Dr. Dawson concluded 

that they belonged either to some of the older members of the Silurian 

system or to a still earlier period. In the first edition of the Acadian 

Geology Dr. Dawson stated that the rocks are certainly older than the 

Devonian; and he was inclined to believe that they represented the 

Potsdam sandstone and Utica and Hudson River shales, in an altered 

condition.7 On the accompanying map their geographic distribution

1 Remarks on the geology and mineralogy of Nova Scotia. Halifax, N. S., 183C, pp. 272.

* A geological map of Nova Scotia, with an accompanying memoir. Geol. Soc. London, Proc., vol. 

4, 1843, pp. 180-190.

3 0p.cit.,p.l87.

4 Geological Map of Nova Scotia. (Accompanying papers by J. W. Dawson and Richard Brown,) 

Quart. Jour. Geol. Soc., London, vol. 1,1845, oppo., p. 23.

6 The industrial resources of Nova Scotia. Halifax, N. S., 1849, pp. 233,234.

6 On the metamorphic and metalliferous rocks of eastern Nova Scotia. Quart. Jour. Geol. Soc., London, vol. 6,1850, p. 348.

Acadian Geology, 1st Edition, Edinburgh, 1855, p. 367.
WAi.coTT.1 NOVA SCOTIA. 57

is shown and in tho legend they are noted as "perhaps altered Lower 

Silurian" strata.

In a supplementary chapter to the first edition the slates and quartzites of the Atlantic coast belt are spoken of, and ifc is suggested that 

they may be a continuation of the Primordial zone of Newfoundland, 

in which Paradoxides have been found. 1 Mr. E. Billings reviews this 

supplementary chapter and says: 2 " We are strongly inclined to the 

belief that this supposition will yet turn out to be well founded."

In 1862 the slates of the Nova Scotia metamorphic slate belt were 

referred to the Taconic System,3 A more detailed description of the 

rocks was published by Dr. J. W. Dawson, in 1808, in which they are 

stated to be formed of granite, gneiss, mica slate, quartz rock or quartzite, and clay slate. The granite appears to be intrusive, and the gneiss 

is considered a product of a metamorphisui or baking of sedimentary 

rocks. The clay slate or argillaceous slate abounds, and is usually, 

along the Ath-ntic coast, of a gray and black color, varying very much 

in texture and hardness.4 He states that the series has not afforded 

fossils, but ifc appears to be a continuation of the older slate series of 

Mr. J. B. Jukes in Newfoundland, which has afforded trilobites of the 

genus Paradoxides. On the map accompanying the volume the geographic distribution of the series is clearly exhibited.

In a general description of the Nova Scotia gold field Mr. J. Campbell 5 publishes a section across the gold-bearing rocks of the Atlantic 

coast, in which the arrangement and relative position of the different 

groups of strata are well shown. There is a great thickness of quartzite subjacent to blue and gray slates divided midway by the "black 

rock." Very few details are given of the section, as the report is 

mainly devoted to a description of mining and the mode of occurrence 

of gold.

When reporting upon the Waverly gold district Prof. H. Y. Hind 

stated that he had found PalcEotrochus minor and Palccotroclius major of 

Emmons, besides numerous concretionary forms, in the Waverly beds. 

He considers (a) that these fossils, if identical with those from North 

Carolina, probably establish the age of the gold-bearing rocks of Nova 

Scotia; (&) that they occur near the base of the Lower Silurian System; 

(c) that they belong to the upper part of the Potsdam formation and 

the lower part of the Calciferous formation, and (d) that they are subjacent to the great mass of serpentine and red slates, discovered by 

Dr. Honeyman in Antigonish, which belong to the Quebec group. The 

gold series is correlated with that described by Dr. Emmons in North

'Supplementary chapter to tlio Acadian Geology,Edinburgh, 1860, p. 53.

8 [Review of) Acadian Geology and a Supplementary Chapter thereto. Canadian Nat., vol. 5,1800, 

pp. 450-455.

"Marcon, Jnles. [The slato of Nova Scotia, motamorphic Taconic rock.] Boston Soc. Nat. Hist., 

Proc., vol. 0, 1802, p. 47.

'Acadian Geology. Tho geological atrncturo: organic remains, and mineral resources of Nova Scotia, 

New Brunswick, and Prince Edward Island, 2d. ed. London, 18C8, pp. 013-015.

6 Keport on tho Gold Fields of Nova Scotia. Halifax, 1863, pp. 12.
58 THE CAMBRIAN. [BULL. 81.

Carolina.1 In a paper presented to the Geological Society of London,2 

and subsequently published in the report on the Sherbrooke gold district of Nova Scotia, Prof. Hind describes the gold-bearing rocks of 

Nova Scotia as follows:

The gold-bearing rocks of Nova Scotia are of Lower Silurian age, and rest either 

on Huronian strata or, where these have been removed by denudation, on the old 

Laurentian gneiss. The gold is found chiefly in beds of auriferous quartz of contemporaneous age with the slates and quartzites composing the mass of the series, 

which in Nova Scotia is 12,000 feet thick, and the auriferous beds are worked, in one 

district or another, through a vertical space of 6,000 feet. 3

In a report on the gneissoid series underlying the gold-bearing rocks 

of Nova Scotia the same writer4 states that he has provisionally referred 

the gold-bearing series to the Lower Silurian, but that conclusive evidence derived from fossils has not been obtained from the gold-bearing 

slates and quartzites. Since the discovery of the forms resembling the 

Palaeotrochus of Emrnons, noticed in his report on the Waverly district, he has sent to Mr. Billings slabs containing supposed fossils from 

the Sherbrooke rocks. Mr. Billings thought that a species of Orthis 

and an Eospongia were indicated. In describing the gold-bearing 

rocks under the head of " Lower Silurian " Prof. Hind5 says:

The known gold-bearing rocks of Nova Scotia consist of quartzites, sandstones 

and grits, interstratified with argillaceous slates and thin conformable beds of auriferous quartz. This portion has an ascertained thickness exceeding 9,000 feet. * * * 

The thickness of the black slates in Nova Scotia exceeds 3, 000 feet, so that the goldbearing rocks of the province have a known thickness of 12,000 feet.

The essential parts of the description in the last paper are also 

printed in the American Journal of Science.6

In his report on the gold fields of Quebec and Nova Scotia, Dr. A. 

B. 0. Selwyn7 speaks of the geological position of the Atlantic coastseries 

of stratified gold-bearing slate and quartzite, stating that all former observers are agreed that they probably belong to the Lower Silurian 

series. His first impression of them was that they represented the 

groups known in Britain as the Harlech grit or quartzite, and the 

Lingula-flag series. He discovered in the gray sandy and flaggy pyritous slates at the Oven's Bluffs numerous specimens of the genus 

Eophyton, and states that Mr. Billings regarded this genus as characteristic of the Primodial Silurian epoch. He then gives an account of 

the distribution of the genus Eophyton, and in conclusion says: " In

1 lloport on the Waverly Gold District, with geological maps and sections. Halifax, 1869, p. 61.

2 On two gneissoid series in Nova Scotia and Now Brunswick, supposed to bo the equivalents of the 

IIuronian (Cambrian) aud Lanrentian. Quart. Jour. Geol. Soc., London, vol. 20,1870, pp. 468-479.

3 Report on the Sherbrooko gold district, together with a paper on tho gneisses of Nova Scotia and 

an abstract of a paper on gold mining in Nova Scotia. Halifax, N. S., 1870, p. 3.

 Preliminary report on a gneissoid series underlying the gold-bearing rocks of Nova Scotia, and 

supposed to be the equivalent of the Laurentian system. Halifax, N. S., 1870, pp. 14.

»0p.0\t,p.8.

6 On tho Laurentian and Hnronian series in Nova Scotia and New Brunswick. Am. Jour. Sci., 2d ser., 

vol. 49,1870, pp. 361-353.

7 Notes and observations on the gold fields of Quebec and Nova Scotia. Goel. Surv. Canada. Report 

Prog, for 1870-'7l, 1872, pp. 2C8-270.
WAI.COTT.I NEW BRUNSWICK AND CAPE BRETON. 59

general aspect, and in the succession of the beds the whole series in 

Nova Scotia closely resembles the Cambrian and Liugula-flag series 

of North Wales." 1

Dr. J. W. Dawson reviews his studies of the Atlantic coast belt of 

Nova Scotia in the supplement to the second edition of the Acadian 

Geology,2 and places the slates and quartzite in the Cambrian. He 

states that the evidence of fossils in determining the precise age of these 

rocks is unfortunately as yet somewhat imperfect, and quotes Prof. 

Hind as saying that the entire thickness of the series is 12,000 feet; 

of this the lower or quartzite and slate division comprises about 0,000 

feet, and the upper or ferruginous slate division about 3.000 feet.

On the colored geological map of the Dominion of Canada, published in 1882, the Cambrian rocks of Nova Scotia are made to extend 

from near the north eastern point of the peninsula south to Sable River, 

where they are interrupted by a mass of granite that extends to Harrington Harbor. From this point around the western slope to Annapolis Basin they occupy a wide strip along the shore. As represented on 

the map they occupy nearly one-half of the area of Nova Scotia.

In 1888 Sir William Dawson reviewed the rocks referred to the Cambrian group on the Atlantic coast of Canada, 3 stating that the Atlantic coast or gold series of Nova Scotia in their western extension 

appeared to rest on rocks of Huronian aspect. He also says:

It has unfortunately afforded no well-characterized fossils. The markings called 

Eophyton and certain radiating bodies (Astropolithon) found in it are, however, similar to those occurring elsewhere in Lower Cambrian rocks. Murray was disposed to 

regard this formation as corresponding to his Iluronian in Newfoundland; but it 

does not agree -with this either in mineral character or in fossils, and is perhaps 

rather to he regarded as a great development of the lowest member of the Cambrian, 

an exaggerated equivalent of the Harlech grits and Llanberris slates. In this case, 

however, it may be expected that it will yet afford true Cambrian fossils. 4

NEW BRUNSWICK AND CAPE BRETON.

In the report for 1842 on the geology of New Brunswick Dr. Abraham Gesner 5 uses the term " Cambrian system." He says:

This name has been applied to a group of rocks situated beneath the " Silurian" 

strata, from which it is not always separated by any very distinct line of demarcation, so far .is its lithological character is concerned. The few organic remains, however, found in this group are sufficiently characteristic to make it appear that the 

forms of animal life during the period of the accumulation of its strata were dift'erent 

from those found in the upper Silurian rocks.

J Op. cit, p. 271.

* Supplement to the second edition of Acadian Geology, containing additional facts as to the geological structure, fossil remains, and mineral resources of Nova Scotia, Now Brunswick, and trince 

Edward Island, London, 1878, pp. 81-83.

3 On tbe Eozoic and Palteozoic rocks of the Atlantic coast of Canada, in comparison with those of 

 western Europe and of the interior of America. Quart. Jour, Qeol. Soc. London, 1888, vol. 44. pp. 804-807. 

Canadian Record of Science, vol.3,1888, pp.182, 183, 230, 231.

" Op. cit., p. 805.

6 Report on the geological survey of the Province of Now Brunswick, with a topographical account 

of the public lands and districts explored in 1842. St. John, 1843, p. 72.
GO THE CAMBRIAN.

Tho rocks of this group extend from the American boundary line and cross the 

St. John a little .above the Meductic, and proceed in a northeast direction toward 

Bathurst. * * *

The strata consist chiefly of grauwacke, gran wacke slate, and clay slate. The gran- 

 vracke may be compared to a very compact sandstone. There are also beds of conglomerate, containing bowlders and pebbles of almost every variety of rock. The 

cementing matter is generally calcareous or argillaceous; but it is sometimes silicious, 

and the beds change imperceptibly into quartz rock. The slates are of different 

colors; red,blue, and green are often seen. Many of them con tain lime, and others 

will supply roofing slate.

The local details of the distribution of this series are not given, nor 

is the locality of the city of St. John mentioned. Portions of the rocks 

mentioned by Dr. Gesner are, however, now included in the Cambrian 

group.

In his third report Dr. Gesner 1 recognizes two series of rocks, both 

of which are referred to the Silurian age. The upper group consists of 

limestones,,slates, and sandstones, containing the remains of plants, 

mollusks, etc. The older group is formed of conglomerates, gray slates, 

sandstones, talcose slates, and the trap beds of Mispeck and Black 

Rivers.

On a map prepared by Dr. James Eobb,2 the geographic distribution 

of the formations described by Dr. Gesner is outlined, and under the 

" Cambrian system " we find the indicated distribution of the Cambrian 

rocks to include Carboniferous, Devonian, Lower Silurian, and Cambrian as now known. In the text of the volume accompanying the map 

Mr. J. F. W. Johnstou3 describes the geographic distribution of the 

rocks and also their general character. He states that the rocks of the 

Cambrian are distinguished from those of the Silurian by their greater 

hardness and by their containing less lime.

In speaking of the rocks referred to the Lower Silurian, and Cambrian, by Gesner and Kobb, Mr. J. W. Dawsou 4 states that for the distribution of these rocks, as indicated on the map, he was indebted 

principally to the map prepared by Dr. Eobb. Of the rocks he says:

I do not think that at present there is any good ground for separating the so-called 

Cambrian rocks from those last mentioned [Silurian], though it is quite probable that 

they may belong to an older formation, or that they may be older members of the 

name formation.

When relating the results of a visit to New Brunswick Prof. W. 

B. Kogers 5 described, by the aid of a section, the stratigraphic features 

exhibited at the junction of the older and less ancient groups of strata 

on the St. John's and Kennebecasis Eivers, a few miles above the city

1 Third report on the geological survey of the province of Now Brunswick. St. John, 1841, pp 5-11.

2 [Letter on the geological structure of New Brunswick. 1 Report on the agricultural capabilities 

of the province of New Brunswick, by J. F. ~W. Johnstou. Fredoricton, 1850, pp. 12, 13.

3 .Report on the agricultural capabilities of the province of New Brunswick. Fredericton, 1850, pp. 

17,18.

4 Acadian Geology, first edition, 1855, pp. 324, 325.

'Remarks on the geology of the neighborhood of St. John, New Brunswick. Boston Soc. Nat. 

Hist-jProc., vol. 7,1861, p. 170.
NEW BRUNSWICK AND CAPE BRETON. 61

of St. John, as observed by Dr. Bobb and himself, Referring to the 

probable ages of the two groups he states that the only fossils discovered consist of vegetable impressions found by Dr. Eobb at several 

localities, and some black scale like fragments of shells that he found 

about the city of St. John in loose pieces of siliceous slate. At several 

points the layers of rock in place are crowded with these remains, the 

more entire of which presented the form and markings of a Lingula.

Dr. J. W. Dawson described iu 18G2 the strata about St. John, and 

published a section 1 that includes the shales and slates of the vicinity 

of the city; and, iu the same section, a series of beds which have since 

proved to be of Devonian age. He states that the age of the lower 

members was less certain. They may represent either the Middle and 

Lower Devonian, or may be in part of Silurian age. " The only determinable fossil, the Lingula of the St. John shales, affords no decisive 

solution of this question."

In proposing a classification for the pre-Devonian rocks of New Brunswick, Mr. G. F. Matthew 2 states that Gesner's older group is to a 

great extent younger than his upper series. Be reviews the classification of Dr. Dawson 3 dividing the formations into several groups, proposing the name St. John group for Nos. 5 and C (in part) of Dawson's 

section of 1862. He says that the St. John group is formed of several 

zones of soft, black, dark gray, finely laminated shales, alternating with 

zones of coarser gray slates, containing, numerous thin beds of finegrained sandstone, the whole having a thickness of about 3,000 feet. 

The fossils noticed were a Lingula, a Conchifer, Annelids and Coprolites.4 

TheColdbrook group, No. C of Dawson, in part, is given a thickness of 

3,000 feet or more composed of greenish gray slate, bright red slaty 

conglomerate and dark red sandy shale, with a reddish conglomerate, 

grit aud hard, gray sandstone. The paper is accompanied by a map 

showing the geographical distribution; also a section crossing the district in the vicinity of St .John. In a foot-note mention 5 is made of 

the discovery of numerous trilobites of two or three species, but they 

were so excessively distorted that the genera could not be made out.

Li some observations on the geology of southern New Brunswick, 

Prof. L. W. Bailey 0 reprinted the table of formations published by Mr. 

Matthew in 1863. In a table on page 14 he places the St. John group 

at the base of the Lower Silurian as an equivalent of the Potsdam or 

Primordial of New York and the Quebec group of Canada. A full description of the St. John group is given,7 and accompanying it a letter

1 On the flora of the Devonian period iu northeastern America. Quart. Jour. Gcol. Soc. London, vol. 

18,1862, p. 303.

a Observations oil the geology of St. Johii County, New Brunswick. Canadian Nat., vol. 8,1803. p. 

243.

3 Op. cit.,p.24'2.

4 Op. cit., p. 244.

« Op. cit., p. 247.

 Observations on the geology of southern New Brunswick. Fredericton, 1805, p. 8.

1 Op. cit., pp. 20-31,
62 THE CAMBRIAN. (BULL.81.

from Mr. C.Fred Hartt,1 in which he states that he has recognized four 

genera of trilobites from the St. John rocks, viz, Paradoxides, Conocephalites, Aguostus and a new genus (?) allied to Conocephalites. 

There are also six species of Brachiopods, belonging to the genera Orthisina, Discina, Obolella, and Lingula. Although all of the species are 

apparently new, the occurrence of Paradoxides and Conocephalites led 

Mr; Hartt to correlate the entire fauna with the Primordial fauna of Barrande. He states that the lower part of the St. John group, at Coldbrook, has been divided by Mr. Matthew, on lithological grounds, into 

three bauds, viz:

No. 1. The lower or arenaceous band, with no determinable fossils, and constituting passage beds from the Coldbrdok group.

No. 2. Argillaceous shales, rich in fossils, Paradoxides, Orthisina ?, Conocephalites, Obolella.

No. 3. Carbonaceous shales, full of fossils, Paradoxides, Conocephalites, Orthisina, Discina, etc., all much distorted.

In the same year Mr. G. F. Matthew described the Azoic rocks of 

southern New Brunswick.2 He gave the geographic distribution of 

the St. John series, and a detailed section of the formation, to which he 

assigned a total thickness of 4,500 feet. He mentions the identification 

of the fauna by Prof. Hartt; and refers the St. John group to the Lower 

Silurian, correlating it with the Paradoxides liarlani beds of Massachusetts} with the Paradoxides bennetti beds of Newfoundland; the Lingula flags of Great Britain; the alum-schists of Scandinavia and 

"Stage C" of Barrande in Bohemia.3 He states that the upper portion of the section may be the equivalent of the Calciferous, perhaps 

the Chazy. The subjacent Coldbrook group is referred to the Huronian, 

while the terms Cambrian and Huronian are used as synonyms in their 

application to the Coldbrook formation.4

In noticing the discoveries made by Messrs. G. F. Matthew and 0. F. 

Hartt, Dr. J. W. Dawson refers to the correlation made by Prof. Hartt, 

and proposes to call this series, represented in New Brunswick by the 

St. John slates, the Acadian series.5 In 1868 he republished all the facts 

known to him in relation to the St. John group, naming it the Acadian 

group, and including it under the Lower Silurian.6 The section given 

by Mr. Matthew is published, and also descriptions by Mr. C. F. Hartt 

of all the species discovered by Messrs. Matthew and Hartt in the St. 

John group.7

1 Preliminary notice of a fauna of the Primordial period in the vicinity of St. John, N. B. Observations on the Geology of southern New Brunswick, 18G5, pp. 30,31.

2 On the Azoic and Paleozoic rocks of southern New Brunswick. Quar. Jour. Geol. Soc., London, 

vol. 21,1865, pp. 422-434, map.

3 Op. cit., pp. 426,427.

« Op. cit, p. 427.

* On recent geological discoveries in the Acadian provinces of British America. Am. Assoc., Proc., 

vol. 16,1867, p. 118. Canadian Nat, new series, vol. 3,1868, pp. 295-297.

6 Acadian Geology. The geological structure, organic remains, and mineral resources of Nova Scotia, New Brunswick and Prince Edw. Island, London, 1868, pp. 637-641,2d ed.

1 0p. cit., pp. 641-657.
VVALCOTT.] NEW BRUNSWICK AND CAPE BRETON. 63

In 1869 Messrs. Matthew and Bailey 1 described in a general manner 

the rocks referred to the Lower Silurian and stated that this series includes about 150 feet of slates (holding Paradoxides, Conocephalites, 

Agnostus, and other trilobites, besides several genera of Brachiopods), 

and an overlying mass, measuring not less than 2,000 feet, of flags and 

slates containing Lingulee, worm burrows, etc. Under the caption of 

u Lower Silurian," the same writers, three years later,2 include the St. 

John or Acadian group. A brief historical sketch is given, and a list of 

fossils that have been described from the formation, with a statement 

that the apparent thickness of the whole formation, as measured in the 

city of St. John, is about 4,500 feet. Owing to the disturbed condition of 

the beds the actual thickness may be much less. If repetitions occur, 

the aggregate thickness of the series, exclusive of the lower red beds 

which have been called Upper Coldbrook will not much exceed 2,000 

feet.3 This general description is followed by a detailed one, and a 

copy of Mr. Matthew's section at the city of St. John.4 The St. John 

group is then described as found in the Kennebecasis Valley, in northern King's County; in Wickham, Queen's County; in Nerepis Valley, 

and in Charlotte County.

In the supplement to the second edition of Acadian Geology, Dr. J. 

W. Dawsoii5 introduces the term "Cambrian" and includes under it the 

Acadian series of St. John and also the great Atlantic coast series of 

Nova Scotia. Nothing is added in the way of descriptive details to 

those given in the edition of 1868.

During the survey of the island of Cape Breton, Mr. Hugh Fletcher 

discovered near Marion Bridge, on the banks of the Mira Eiver, aseries 

of light gray, slaty, fine-grained, feldspathic sandstones, associated 

with red and green mottled sandstone in which he° found numerous 

specimens of Obolella. He points out the litliologic resemblance of 

these rocks to the Primordial rocks found by Mr. Alexander Murray in 

the southeastern part of Newfoundland and to those on the Strait of 

Belle Isle examined by Mr. Kichardson.6 lie also describes a series of 

purple, red, and green slates, sandstones, arid limestones, that he refers 

to the Lower Silurian.7 A detailed section of the rocks is given as they 

occur along St. Andrew Channel. In one of the greenish and blue 

papery slates he found impressions of an Obolella, with the head and 

tail of a trilobite, recognized by Mr. Billings as of Primordial or Quebec

1 Remarks on the ago and relations of the luotamorphic rocks of Now Brunswick and Maiuo. Am. 

Assoo., Proc., vol. 18,1869, pp. 182,183. Can. Nat., now ser., vol. 4,1809, pp. 320-328.

2 Preliminary report on the geology of southern New Brunswick. Gcol. Surv. Canada, Hop. of Prog., 

1870-'71,1872, p. 134.

"Op. cit., p. 135.

«0p.cit., pp. 136,137.

6 Supplement to the second edition of Acadian Geology, containing additional facts as to the geological structure, fossil remains, and mineral resources of Nova Scotia, New Brunswick, and Prince, 

Edward Island, London, 1878, p. 81.

6 Keport of explorations and surveys iu Cape Breton, Nova Scotia. Geol. Surv. Can., Hep. Prog. 

1875-'70, 1877, p. 393.

7 Op. cit.,p. 388.
64 THE DEVONIAN AND CAKBON1FEROUS. [BULL. 81.

group age. In Iris report for the following year lie 1 described a num 

ber of sections, referring them to the Lower Silurian, and mentioning 

the occurrence of Lingula, Obolella, and Dictyonema in some of the 

beds.

In a report on the slate formation in the northern part of Charlotte 

County, New Brunswick, Mr. G. F. Matthew 2 states that the St. John 

group occurs in the interval between the Kingston or Upper Silurian 

rocks and the inclosing Laurentiau ridges in King's County. No details 

are given of the St. John group.

A report on the Primordial-Silurian rocks of New Brunswick by Mr. 

L. W. Bailey3 presents a detailed description of the St. John group. A 

section is given of the strata on Eatcliffe's Mill-stream and ffandford 

Brook and local details of geographic distribution. This is accompanied 

by a list of the fossils found which were identified by Mr. J. F. Whiteaves.

In a later report on the geology of southern New Brunswick4 the 

Cambrian or Primordial Silurian rocks are described as occupying 

basins or trough-like depressions among the older hills of pre-Cambrian 

rocks east of the St. John River.

In speaking of the strata carrying the Parad oxides in the vicinity 

of the city of St. John, Mr. G. F. Matthew5 states that the strata of 

the St. John group fill a number of narrow, trough-like basins lying 

between the Bay of Fuudy and the central Carboniferous area of New 

Brunswick. A carefully measured and detailed section of the St. John 

outcrop is given with a description of the conditions under which the 

fossils occur in the same. A thickness of 2,900 feet is assigned to the 

section.

The same writer argues iu a paper on the "Geologic Age of the 

Acadian Fauna" 6 that on the evidence of the trilobites the St. John 

group does riot quite correspond to the Meueviau of Wales, iu the restricted application of that term; but, as a whole, they indicate the subjacent Solva group as the equivalent formation to the St. John group. 

He repeats this correlation a year later,7 when he says: " Prof. Hartt 

fixed the age of the St. John group as nearly as was possible in his time

1 Report on the geology of part of the counties of Victoria, Cape Breton, and Richmond, Nova Scotia. 

Geol. Surv. Can., Rep. Prog, for 187G-'77. Montreal, 1878, pp. 429-437.

2 Report on the slate formations of the northern part of Charlotte County, New Bruiiswick. Geol. 

Surv. Canada, Rep. Prog, for 187G-'77. Montreal, 1878, pp. 342, 343.

3 Report on the prc-Siluriau (ITiiroiiiaii)and Cambrian or Primordial Silurian rocks of southern New 

Brunswick. Gool. Surv. Can., Rep. Prog., 1877-'78, 1879; p. 28DD-34DD.

4Bailey, L. W., G. P. Matthew, and R. W. Ells. Report on the geology of southern New Brunswick, 

embracing the counties of Charlotte, Suubury, Queens, Kings, St. John, and Albert. Geol. Surv. Can., 

Rep. Prog., 1878-1879, 1880, pp. 6D-8D.

6 Illustrations of tha fauna of the St. John group. Royal Soc. Canada, Proc. and Trans., vol. 1, sec. 

iv, 1883, pp. 8.-88; pp, 271-279.

6 The Geologic Age of the Acadian fauna. The Primitive Conocoryphean. British Assoc. Rep., 54th 

meeting, 1884, pp. 742-743. The Geologic A go of the Acadian Fauna. Geol. Mag., new ser., decade 3, 

vol. 1, 1884, pp. 470-471.

7 An outline of recent discoveries in the St. John group. Now Brunswick Nat Hist. Soc. Bull. No. 

4,1885, p. 88.
WALCOTT.] NEW BRUNSWICK AND CAPE BRETON. 65

as ' Primordial,' or, as we now call it, Cambrian." He then calls attention to the article in which he correlated the St. John group fauna with 

the Solva group, stating, u In other words, it is the fauna of the older 

part of the Lower Cambrian."

In a preliminary study of the Cambrian fauna of North America1 a 

review is given of the history of the term " St. John group " by Mr. C. D. 

Walcott. In this the use of u St. John " was advocated as against "Acadian," and all species described by Mr. C. F. Hartt in the second edition 

of Dawson's Acadian Geology were illustrated.

When discussing the faunas of the St. John group, Mr. Matthew2 states 

that it is highly probable that the group covers nearly the whole of the 

Cambrian age; and that the fauna of the Upper Cambrian is equivalent 

to that of the shallow-water deposit of the St. John group near the summit of the series. The fauna discovered by Mr. Fletcher in the Cambrian shales of Mira Kiver, Cape Breton Island, is considered by Mr. 

Matthew3 to belong to the Olenus division of the Cambrian fauna. The 

species recognized by him are Peltura scarabceoides, Spliccrojplitlialmus 

alatus, and Agnostus pisiformis. In the same paper he mentions the 

faunas of the Oleuus division as found in Newfoundland. (An abstract 

of this paper appeared in the Canadian Record of Science, vol. 2,1886, 

pp. 255-258.)

Incited by the announcement of the discovery of fossils beneath the 

Paradoxides zone in Sweden and Kussia, Mr. Matthew4 began anew the 

study of the red rocks beneath the Paradoxides zone. These strata 

had been spoken of as the upper member of the Coldbrook group 5 and as 

constituting a series lower than the Primordial rocks at the base of the 

Silurian. They were subsequently joined to the St. John group6 as the 

base of that group. In a later report in 1888, Mr. Matthew7 says: " ft 

is now found that this red series is unconformable, not only to the, St. 

John group, but also (as had been previously discovered) to the underlying Coldbrook group." In the valley of Long Eeach of the St. John 

River Mr. Matthew estimates that the red series has a thickness of 1,200 

feet. He compares it with the red shales described by Dr. Murray in 

Newfoundland8 and correlates it with the Caerfai group of Wales and 

the lower division of the Sparagmite formation of Norway.9 A detailed 

description of the section is given10 with names of the fossils that have 

been found in the various beds. These include trails and casts of marine

1 On the Cambrian faunas of North America; preliminary studies. U. S. Geological Survey Bull. No. 

10, vol. 2, 1884, p. 289, separately paged, p. 9.

2 Illustrations of the fauna of the St. John group, No. 4, Can. Rec. Sci., vol.2,1887, p. 302. (Abstract.)

3 On the Cambrian faunas of Cape Breton and Newfoundland. Itoyal Soc. Canada Proc. and Trails., 

vol. 4, sec. 4,1887, p. 147.

4 On a basal series of Cambrian rocks in Acadia. Can. Rec. Sci., vol. 3,1888, pp. 21-29.

* Observations on the geology of southern New Brunswick. Fredericton, 1865, p. 24.

6 Bailey, L. \V., and G. F. Matthew. Preliminary report on the geology of southern New Brunswick. 

Geol. Surv. Can., Rep. Prog., 1870-71,1872, p. 59.

7 Ou a basal series of Cambrian rocks in Acadia. Can. Rec. Sci., vol. 3,1888, p. 22;

 Op. cit.,p.23. 1J Op. cit.,p.25. 10 0p.cit.,p.27.

Bull. 81 5
66 THE CAMBRIAN. [BULL. 81.

Avornis, tracks, and an unrecognized brachiopod. This paper was followed in the same year by an article on the classification of the Cambrian rocks of Acadia in which the classification of the Cambrian system in Acadia and Newfoundland is given as follows: 1

Series A. The Basal series or Eteminian. 

Series B. The St. John group or Acadian. 

Series C. The Lower Potsdam or Georgian. 

Series D. The Potsdam sandstone and limestone."

The division of series A was noticed in the preceding paper by Mr. 

Matthew. In series B he includes the zone of Paradoxides; describes 

the rocks in detail, and gives lists of the genera of the fossils. Series 

C, the Lower Potsdam of Billings, he states has not been recognized on 

the mainland of Acatlia, but is found in the Island of Cape Breton, 

where the fossils are Bathyurus, Orthisina, Orthis, Hyolithes princeps. 

This series is placed provisionally above B.2 Series D, or the Potsdam series of New York and the Mississippi Valley, is stated to be absent from New Brunswick and, as far as known, from the eastern 

border of the continent. 3

A reclassification of the Cambrian rocks of North America was published in 1888 by Mr. C. D. Walcott as follows: 4

TABLE I, Lower Silurian (Ordovician) system.

Subdivisions. ' Terranes. Faunas.

Oleuus.

This is followed by a comparison of typical sections of the Cambrian 

system in Sweden, Newfoundland, New York, and the Kocky Mountains. 

The section on Manuel's Brook, Conception Bay, Newfoundland, where 

the true stratigraphic succession of the Cambrian deposits in America 

was first discovered, is given in detail.

On learning of the discovery of the Olenellus fauna beneath the 

Paradoxides zone in Newfoundland, Mr. Matthew published a second 

paper "On the classification of the Cambrian rocks in Acadia," in 

which he arranged the Cambrian system as it occurs in Acadia as 

follows: 5

Localities. 

D. Upper Cambrian (Potsdam series) ................................ Unknown.

C. Middle and Lower Cambrian Acadian series ..................... St. John, etc.

B. Lower Cambriau Georgian series ................................ Cape Breton.

A. Basal Cambrian Etchemiuian series ...........'.................. St. John, etc.

t Matthew, G.F. On the classification of the Cambrian rocks of Acadia. Can. Kec. Sci., vol. 3,1888, 

p. 72.

*0p. cit., pi). 73-74. 3 Op. cit., p. 80.

*The stratigraphical Succession of the Cambrian faunas in North America. Nature, vol. 38,1888, 

p. 551.

* On thb clae'sificatitfn of the Cambrian rocks in Acadia. NOJ 2. Can. Kec. Sci., vol. 3, 1889, p. 310.
WALCOTT.1 NEW BRUNSWICK AND CAPE BRETON. 67

*

Instituting comparisons between the sections of Sweden and New 

Brunswick, he discusses the general relations of the Cambrian fauna 

of North America. The organic remains found in band B are an 

Agraulos, and at the base of the zone an Ellipsocephalus, of the type 

associated with Olenellus (1) Igerul/i in Europe. At the base of band B 

he found a species of Obolus which he described as Obohcspidcher. 1 This 

comprises the Lower Cambrian fauna or pre-Paradoxides fauna as 

known to him from New Brunswick up to date.

In another paper on the u Cambrian organisms in Acadia," published in the same year, he notes the discovery in the lower beds of the 

St. John section, beneath the Paradoxides beds, of several varieties of 

sponges, a species of Pakeochorda and another uudescribed species. 

Undoubted examples of Platysoleuites of Pander also occur.2 Mention is made of the discovery above the Paradoxides zoneiutheOleuus 

horizon, of three species of fossils, and above this another stage which he 

has placed under the title of Peltura beds, corresponding in age to the 

Cape Breton Upper Cambrian beds.

In September, 1889, Mr. Matthew 3 argues for the uniting' of the 

Oleuellus or Lower Cambrian, and the Paradoxides or Meuevian zone, 

as one division of the Cambrian, and the strata above the Paradoxides 

zone as the upper division, thus returning to the classification of Salter 

and Hicks, adopted for the Cambrian strata of Wales.

The full text of Mr. Matthew's paper on the Cambrian organisms in 

Acadia was distributed in June, 1890. It deals almost entirely with 

the pre-Paradoxides or Basal series of the Cambrian section of New 

Brunswick, and is accompanied by both tabulated and illustrated sections and sketch maps of Hanford Brook and Catou's Island.4 It is 

referred to at length in the description of the Cambrian rocks of New 

Brunswick in this paper (Chapter, iv).

In a paper read May 28,1890, Mr. Gr. F. Matthew gives a detailed 

description of the geologic structure of the St. John basin in connection 

with three sections crossing it. Further notice of it will be found in 

the summary of our present knowledge of the St. John terraue of New 

Brunswick.5

In a list of the geological formations of the Maritime Provinces of 

Canada, Dr. George M. Dawson tabulates the Cambrian as follows: 6

:2c. Upper Cambrian ................................. j Mire" and St. Andrew series.

( Cape Breton. 

'Zb. Middle Cambrian ..................................Acadian series.

2a. Lower Cambrian................................ 5 Atlantic Coast series.

( Nova Scotia.

1 Op. cit., p. 300.

2 0u tho Cambrian organisms in Acadia. Can. Kec. Soi., vol. 3,1880, p. 384. '

3 How is tho Cambrian divided ? A plea for the classification of Salter and Hicks. Am. Geol., vol. 

4,1889, pp. 139-148.

4 On Cambrian organisms in Acadia. Trans. Roy. Soc.'Can., vol. 7, sec. 4,1890, pp. 138-143. 

5 Matthow, G. F. Illustrations of the fauna of tho St. John group, No. 5. Trails. Koy. Soc. of Canada, 

Vol. 8, soc. 4,1891, pp. 123-130, pis. n-xvi. 

*An American Geological Railway Guide. Jamo sMcFurlaue. 2d ed., 1890, p. 52.
68 THE CAMBRIAN. [BULL. 81.

MAINE.

When describing the quartz rock of Bar Harbor, Mount Desert 

Island, Prof. 0. H. Hitchcock 1 suggested a Lower Silurian age for the 

siliceous slates associated with the coarse sandstone or quart/ rock, 

by comparison with similar rocks on Flint Island, of which he had 

stated that the correlation was more from fancy than real argument, 

because it reminded him so much of the Potsdam sandstone in its external appearance.

At a later date he says: 2

The first rock is a sandstone at Bar Harbor, dipping at an angle of twelve degrees. 

Ripple marks cover the surface of many layers, and curious cylindrical stems tantalize 

us by their resemblance to fossils. The formation is probably of Cambrian age.

The strata included under the title of "Cambrian" about Portland, 

Maine, is described by Prof. Hitchcock 3 as follows:

These rocks crop out in Saco, a dozen miles west. They are clay slates and indurated argillaceous schists, the latter having a north west strike, while the rocks of the 

older series run northeasterly. These rocks are in character and position allied to 

the Cambrian Paradoxides slates of Massachusetts, and exist in immense mass along 

the coast of Maine west of Saco, and in New Hampshire.

The correlation of these beds is based entirely upon their lithological 

characters, as no mention is made of any fossils having been found in 

them.

In his account of the geology about Frenchman's Bay, on the coast 

of Maine, Dr. W. O. Crosby describes the slate formation. The prevailing rock is a compact and well jointed argillite or clay slate, of 

black, drab, and purple tints, with distinct stratification. The author 

concluded that these rocks are the newest rocks on this part of the 

coast, by their relations in dip and distribution to the present contours 

of the land; by their uncrystalline character; by their relations to the 

iatrusives; by the fossils which they contain. The latter he describes 

as smoothly and even gracefully curved semi-cylindrical grooves and 

ridges about a line in diameter; they are often a foot or two in length, 

and might sometimes be regarded'as annelid trails, but in other cases 

they are irregularly branched in a way that would be impossible with 

worm-grooves, but is very suggestive.of smooth, slender fucoids.4 The 

general conclusion reached was that the Frenchman's Bay series belonged somewhere between the top and bottom of the Cambrian, with 

the chances in favor of its being near the latter. In other words, his 

observations tended to corroborate the suggestion made by Prof. Hitchcock twenty years before. He further states:

1 Reports on the Geology of Maine. Second annual report on the natural history and geology of 

Maine. Augusta, 1862, pp. 209-271.

2 Geology of New Hampshire. Concord, 1877, vol. 2, p. 32.

3 The geology of Portland. Am. Assoo. Proc., vol. 22, pt. 2,1873, p. 168.

4 Geology of Frenchman's Bay, Maine. Boston Soc. Nat. Hist., Proc., vol. 21,1881, pp. 111-116. Geolof Frenchman's Bay, Maine, just east of Mount Desert Island. Am. Jour. Sci., 3d ser., vol. 23,. 1882, p. 64*
WALCOTT.J MAINE. 69

The resemblance of these rocks to the Acadian slates of the Boston Basin and St. 

John is very marked; and I join with Prof. Hitchcock iu anticipating the discovery 

ou the Maine coast of characteristic Primordial fossils. 1

Iii describing a geologic inap of Maine, Prof. Hitchcock says that he 

is unable to divide the Cambrian and Huronian, owing to a want of 

knowledge of their distribution.

They are the talcose and mica schists of the reports, called the Quebec group by 

H. Y. Hind and Sir W. E. Logan; the St. John's group in New Brunswick, and the 

Merrimack, Rockingham, Kearsage, Audalusite, and Coo's groups of the New Hampshire reports. * * * They were called Cambrian in New Brunswick by Gcsner, 

and in our second report it was said that this term might ultimately express their 

true age. Subsequently Bailey and Matthew referred them to the Lower Devonian 

but the drift of opinion is towards the earlier view at present. 2

On the map it is very difficult to make out the distribution, owing to 

the color of the Laurentiau, Silurian, and the Cambrian being aj>parently identical. The supposed Cambrian rocks of New Hampshire 

and southeastern Canada follow up the valley of the St. John Kiver 

from a little distance above the entrance of the Allegosh lliver, and 

along the Canadian boundary line nearly to the boundary of New 

Hampshire. The Canadian extension of these rocks is described more 

in detail and will be mentioned under the head of the Canadian Extension of the Northern Appalachian District (Chapter iv)..

In the latest contribution that we have upon the subject of the geological age of the siliceous slate and associated sandstones or quartz 

rocks of Mount Desert, Maine, Prof. Shaler says: 3

We note in the first place that there is a total absence of limestones in all the Actions exposed to view. A careful -study of the drift materials on the south part of 

Mount Desert and on the Cranberry Islands where we could hope to find traces of 

bidden limestones shows that there are no limy bods in the sedimentary deposits of 

this island. The aggregate thickness of the various Mount Desert sections can not be 

less than about 6,000 feet and may amount to one-half more than this estimate. It 

seems as if this fact must exclude the hypothesis that these strata wore formed anywhere in the periods above the level of the Cambrian, for nowherp above that level 

do we have any such sections barren of limy matter.

It may be next noted respecting the schistose series of Mount Desert that those of 

its east and west margins are of singularly uniform composition. They were doubtless originally shales and thin sandstones of great uniformity of structure. Their 

texture is not such as at all points to exclude the preservation of fossils; indeed the 

greater portion of the deposits are well fitted to .exhibit organic remains, yet they 

have afforded no trace of them. Nowhere above the level of the Cambrian scries do 

we find any section of this description. On these grounds, it seems reasonable to 

place the greater part of the Mount Desert rocks in the lower portion of the" Cambrian 

section, if not yet lower iu the geological column.

This coincides with the views of Hitchcock and Crosby, that the 

strata under consideration are of pre-Silurian and probably of Cambrian 

age.

'Op. cit.,p. 117.

2 Geological map of Maine (with notes on geology of). In Geology of Northern New England, 

1885, p. 2.

3 The geology of the island of Mount Desert, Maine. Eighth Ann. Hep. TJ. S. G-eol. Survey, pt. 2,1889, 

p. 1059.
70 THE CAMBRIAN. [BULL. 81.

NEW HAMPSHIRE.

lu the final report of the geology and mineralogy of New Hampshire, 

Dr. C. T. Jackson describes the Cambrian system as understood by him 

at that time, and states that metamorphic Cambrian rocks occur in 

New Hampshire, but they contain no fossils. He also says:

The oldest transition, or Cambrian rocks, occur in Maine and Vermont, and dip in. 

opposite.directious, indicating an anticlinal axis in New Hampshire.

On the eastern side of this axis we discover the first distinct fossils in the slate 

strata on the Kennebec River, where the strata dip boldly to the northwestward.

On the western side we have not yet determined the limits of the Cambrian fossils, 

but indistinct remains of organic substances, whose nature is problematical, occur in 

the neighborhood of Castletou, and along the western flank of the Green Mountains. 

They were supposed by Dr. Carr, who first noticed them, to be graptolites, which are 

supposed to be allied to sea-pens. Graptolites are described by Mnrchison as belonging to the lower part of the Silurian system. He states, however, that these pen-like 

serrated fossils have a great vertical range in the older or protozoic rocks, being found 

from the lower part of the Ludlow formation down to very ancient beds in the Cambrian system.

Should these fossils prove to be graptolites, they would indicate the proximate limits 

of the Cambrian rocks on the western side of the New Hampshire anticlinal axis, 

where the strata dip to the southeastward.

It will be observed that the strata become more and more recent as we proceed 

eastward and westward from this axis, as is proved by order of superposition, lithological characters and fossil contents of the rocks. T j

Prof. Hitchcock says2 that the term Cambrian is misapplied by Dr. 

Jackson, and the ideal section showing the structural geology is incorrgct in many of its details. In the final report of the second geological 

survey of New Hampshire he describes the Kockiugham mica-schist as 

an uncouth mica-schist. The Merrimack group is a micaceous quartzite that has not yet been fully separated from the previous group. It 

abounds in beds of coarse, indigenous granite, which seem to have been 

altered in situ from the feldspathic conglomerate. In certain parts of 

Strafford County the granite beds predominate, forming numerous hills, 

while the slate occupies the valleys between.3 Some schists with interbedded clay slates which are referred to the Merrimack group, are supposed to be equivalent to the Paradoxides beds of Massachusetts.

The Connecticut Coos period can easily be divided into three parts: first, the epoch 

of the deposition of the mountain masses of silica; second, of hornblende and mica 

schists; third, of limestone. 4

In the White Mountain region there are several small areas of audalusite slate, 

supposed to be the equivalent of the Coos group. * * * * The Coos period was 

terminated by eruptions of syenitic grauito. * * * * The Coos quartzite now 

constitutes a distinct range of mountains. 5

The Mount Mote conglomerate is formed of an eruption of igneous 

material cementing together the slaty fragments. This is included in the

'Final report on the geology and mineralogy of the State of New Hampshire, with contributions 

towards the improvement of agriculture and metallurgy. Concord, 1844, p. 14.

2 History of the Geological Surveys in New Hampshire. Geology of New Hampshire, vol. 1,1874,p. 11. 

3 Physical history of New Hampshire. Geology of New Hampshire, Concord, 1874, vol. 1, p. 536. 

4 Op. cit., p. 537. *0p. cifc., p. 538.
WAMOTT.] NEW HAMPSHIRE. 71

section between the Hnroniau and the Helderberg period. On the map 

facing page 536 the formations referred to tlie mica-schist period are 

clearly outined. In a subsequent paper Prof. Hitchcock1 presented a 

table or scheme representing the stratigraphical column of New Hampshire. The Cambrian includes at the summit the Eockingham schists, 

and below, in order, the calciferous mica-schist, the Coos group, clay 

slates, and Mount Mote conglomerate. The description of the various 

formations is given on page 13 and on the map the geographic distribution is delineated. This paper appears to have been prepared and published prior to the issue of the second volume of the Geology of New 

Hampshire2 and it does not refer to the volume. On page 674 of the 

latter work the formations in New Hampshire are tabulated as follows:

Feet.

f Upper Helderberg (Vermont) 200; Lower Helderberg, 500...... 700

I

Calcil'erous mica schist........................................ 4,800

t Staurolite elate ................................. 3,000

Coos group. < Mica schist, often stanroliferous ................. 3,300

( Quartzite.---................................... 1,000

.Cambrian slates (Connecticut Valley).......................... 3,000

Total Paleozoic......................................... 15,800

fKearsarge andalusite group ...... t .................. .......... 1,:500

I Rockiugham mica-schist....................................... 6,000

Paleozoic? { Merrimack group ............................................. 4,300

I Ferruginous slates, with steatite (probably repetition of prececll iug) ........................................................ ___

Total Paleozoic?........................................ 11,600

Under the head of Cambrian, in the Geology of Northern New 

England, Prof. Hitchcock says :3

The discussions about the value of the Cambrian series are leading geologists to 

assign to this place in the column a thick mass of sediment, usually without fossils 

and largely argillaceous in character. We may for the present place here the following groups: (1) Mica-schists of southern New Hampshire. (<J) Merrimack group, 

including argillo-quartzites in Coo's County. (3) Coo's group. (4) Clay slates. (5) 

Mount Mote conglomerates.

In one of his later papers, Prof. Hitchcock,4 in speaking of the various 

formations that make up the mica-schist group, says they may be called 

Silurian, Cambrian, or pre"-Cambrian, according as each author is inclined to regard New England as very ancient or on the verge of the 

Paleozoic. In a table giving the thickness of the formations 5 the 

Cambrian slate series has a thickness of 4,000 feet; and beneath it

1 Geological map of New Hampshire and Vermont, with notes on topography and geology. In Geology of Northern New England, 1874, p. 9. 

* Hitchcock, C. H. Geology of New Hampshire, Concord, 1877, vol. 2.

3 Geological map of New Hampshire and Vermont, with notes on topography and geology. In Geology of Northern Now England, 1874, p. 13.

4 Geological sections across Vermont and Now Hampshire. Am. Mua. Nat. Hist., Bull., vol. 1,188i, 

p. 108. 

6 Op. cit., pp. 178,179.
72 THE CAMBRIAN. lnuiL.81.

we find the Crystalline group that was referred to the Cambrian in the 

Geology of Northern New England in 1874, as follows:

Crystalline group.

Feet. 

Calciferous mica-schist and Coos group ..................................... 12,000

Ke.irsarge group.....! .................................................... 1,300

Rockingham mica-schist................................................... 6,000

Merrimaclt group .......................................................... 4,300

Beneath the Merrimack group the Huronian is placed, with a thickness of 12,000 feet.

In a tabulation of the geological formations of Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, and, Connecticut, by 

Prof. Hitchcock, 1 thecalciferous mica-schist,staurolite slate and schists, 

qnartzite, andalusite schists, and Eockingham mica-schists are included in the Cambrian. In a foot-note he says that the quartzite, 

staurolite slate and schist, and the calciferous mica-schists may yet 

prove to be Silurian. In his -classification of the Paleozoic rocks of 

New England he places under Cambrian the St. John or Braintreeslate, 

Taconic slate, and Roxbury conglomerate.

In a table published in 1890 he includes only the Potsdam, Georgia, 

Acadian, and the Taeonic slate (in part) in the Cambrian. All of the 

foliated crystalline rocks of New England are classified as pre-Cambrian.2

EASTERN MASSACHUSETTS.

The references to the argillite and limestone in which the Cambrian 

faunas have been found, in the Boston and Narragansett Basins, occur 

in most of the publications relating to the geology of eastern Massachusetts. In 1818 Messrs. J. F. and S. L. Dana stated that the argillite was the oldest rock known in the region.3 Its distribution is shown 

in a general way upon the map accompanying the report. It is stated 

to be subjacent to the syenite in Milton and Braintree, and to be 

stratified. In the works of Prof. Amos Eaton 4 the rocks of eastern 

Massachusetts are shown in sections, but nothing is added to the data 

given by the Messrs. Dana.

The next description of the geology of Boston and vicinity, by Dr. 

J. W. Webster,5 mentions that the light gray clay slate is the only rock 

found on the Boston Peninsula in situ. He noticed the presence of the 

slate in Quincy and also at Nahant.

1 Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, and Connecticut. (Geological formations.) Macfarlane's Am. Geol. K. E. Guide, 1879, p. 5C.

2 Idem., second edition, 3800, p. 86.

3 Outlines of the mineralogy and geology of Boston and its vicinity, with a geological map. Am. 

Acad. Arts and Sciences, Memoirs, vol. 4, 1818, pp. 129-223.

4 An Index to the Geology of the Northern States, with a transverse section from Catskill Ifonntain 

to the Atlantic. Leicester, 3818, pp. 53. A Geological and Agricultural Survey of the District Adjoining the Erie Canal, Albany, 1824, pp. 1C3, plate.

6 llemarka on the geology of Boston and its vicinity. Boston Jour. Phil, and Arts, vol. 2,1824, pp. 

277-292.
EASTEEN MASSACHUSETTS. 73

Iu 1832 Prof. Edward Hitchcock1 described the argillite io the vicinity of Boston, aud stated that the unstratih'ed rocks were of igneous 

origin and intrusive among the stratified rocks. A general description 

of the argillite is given in the text with localities, aud on the map the 

geographic distribution, as known to him, is delineated. This includes 

the Quiucy locality. In the final report of the Massachusetts survey 

Dr. Edward Hitchcock, in speaking of the argillaceous slate of the eastern part of the State, says that owing to its intimate connection with varieties of rock referred to the Gray wacke group it ought to be described 

as one of the members of it, although marked as a distinct deposit on the 

map. He considered this slate as older than the graywacke, because 

fragments of the slate occur in one of the varieties of conglomerate of 

the graywacke.2 On the same page, in describing the limestone in the 

southwest part of Attleborough,he says small beds of compact light 

gray limestone occasion the red sandrock. He did not see much of it 

in place, but the numerous blocks in the stone walls indicated its existence in that locality. On the map accompanying the report the argillaceous slate is shown in eastern Braintree, the central part of Quincy, 

and thence extends across Milton and Dorchester to Roxbury. A small 

outcrop is also indicated on the north side of Nahaut. The North'Attleborough locality of the Cambrian as now known is covered by the 

Carboniferous (No. 17 of the legend of the map). The description in. 

the report of 1841 is essentially the same as in the preliminary report of 

1833.

In an article on the crystalline limestones of North America Dr. T. 

S. Hunt 3 suggests that the limestones interstratified with the red slates 

at Attleborough, as described by Dr. Hitchcock, may correspond to 

those which with similar slate and sandstone are met with at the base 

of the Carboniferous formation in Canada and in New Brunswick.

The long silence in relation to the geologic age of the altered rocks 

of eastern Massachusetts in the vicinity of Braintree was finally broken 

in 1856 by the announcement of Prof. W. B. Rogers that trilobites of 

the genus Paradoxides had been discovered at a quarry in a belt of 

siliceous and argillaceous slate lying on the boundary of Quincy and 

Braintree, about 10 miles south of Boston. In announcing this discovery he compares the species found with Paradoxides spinosus of Barrande. He states: 4

The rock in which these fossils occur is a compact, dense, rather fine-grained, silico-argillaceous slate or slaty sandstone, containing little or no carbonate of lime. 

* * * » * Qne of k]j e mogt curious facts relating to the trilohite of the Qnincy 

.and Braintree belt ia its seeming identity with Paradoxides harlani, described by 

Green in his Monograph of North American Trilobites.

1 Report on the geology of Massachusetts, examined under the direction of the government of that 

State during the years 1830 and 1831. Am. Jonr. Sci., vol. 22,1832, pp. 1-70, with map. 

* Final report on the geology of Massachusetts, 1841, vol. 2, p. 537, Amherst.

3 Am. Jonr. Sci., 2d ser., vol. 18,1854, p. 199.

4 Proofs of the Protozoic age of some of the altered rocks of eastern Massachusetts from fossils 

recently discovered. Am. Acad. Proc., vol. 3,1856, p. 317.
74 THE CAMBRIAN. [BULL. 81.

He adds further:

The occurrence of well preserved fossils among roots so highly altered and so contiguous to great igneous masses as are the fossiliferous slates of Quincy may well 

encourage ns to make careful search in other parts of New England where heretofore 

such an exploration would have been deemed useless. 1

Prof. Louis Agassiz, in commenting upon the announcement of Prof. 

Eogers, said that, geologically speaking, its importance could hardly 

be overestimated. We have now, he remarked, a standard level upon 

which to build up the formation of the metamorphic rocks.2 Prof. 

E,ogers also communicated the knowledge of the discovery of the 

Braintree fossils to Prof. J. D. Dana, in a letter dated August 13,1856.3 

He states that his attention was called to the locality by Peter Wainwright, Esq., who resided in the vicinity of the quarry.

Dr. Isaac Lea4 visited the Braintree quarry, and in reporting upon it 

to the Philadelphia Academy of Natural Sciences stated that he 

agreed with Prof. Eogers in placing this formation among the more 

ancient of the Paleozoic periods. " It lies directly on the granite rocks, 

or rather it is squeezed in, and is embraced by these rocks (on the east 

and west sides), which are disturbed by an upheaval." He considered 

the trilobito found there to be undoubtedly the same as described by 

Prof. Green many years before under the name of Paradoxidcs harlani.

Prof. W. B. Eogers again called attention to the Braintree locality 5 

for the purpose of noting the fact that the formation was among the 

oldest of the Paleozoic series, and situated somewhere about the level 

of the Primal rocks (Potsdam sandstone and the Protozoic sandstone 

of Dr. D. D. Owen), containing Dikellocephalus in Wisconsin and Minnesota.

In 1856 Prof. 0. T. Jackson ° described the rock at Braintree as a 

blue gray, argillaceous slate, containing silicate of lime but no carbonate, 

and some disseminated iron pyrites. The stratification of the rock, as 

indicated by its grain and cleavage, dips to the north 50°, and runs east 

and west. The existence of the genus Paradoxides in the argillaceous 

slates of Braintree, proves them to belong to the lowest of the fossiliferous 

Silurian rocks, and he believed them to be the geological equivalents 

of the argillaceous slates of Sweden, which are in a similar manner disrupted by the intrusion of syenite.

' Am. Acad.,Proc.,vol.3,1856, p. 318. *Ibid.,p. 319.

3 Discoveryof Paleozoic fossils in eastern Massachusetts. Am. Jour. Sci., 2d sor., vol.22,1850, pp. 

296-298.

4 [On the trilobite formation at Braintree, Massachusetts.] Phila. Acad. Sci., Proc., vol. 9, 1858. 

p. 205.

5 [On trilobites from Braintreo and on the geologic relations of the district.] Boston Soc. Nat. 

Hist., Proc., vol. 6,1856, pp. 27-29, 40, 41. 

« [On the Braintree argillite and its trilobites.] Boston Soo. Nat. Hist., Proc., vol. 6,1856, pp. 42-44 >
WAT.COTT.] EASTERN MASSACHUSETTS. 75

In arranging the collections of the State cabinet of Massachusetts, 

Dr. Edward Hitchcock placed the rock near Boston which carries the 

trilobites in the Silurian and Cambrian.1

Prof. Wt B. Kogers sent to MOMS. J. Barrande 2 a photograph of the 

Paradoxides found at Braintree. Barrande compared it with Paradoxides spinosus and concluded that Paradoxides harlani was a synonym of 

Paradoxides spinosus.

In 1861 Prof. Eogers 3 announced the discovery by Mr. Norman Easton of pebbles carrying fossils of the Potsdam fauna in Carboniferous 

con glomerate north of Fall River, Massachusetts. He thought the forms 

distinctly recognized in the pebbles were Lingula of two species, resembling Lingula prima and L.antiqua of Emmons, from the Potsdam sandstone of New York, and that the rocks from which the pebbles were 

derived were probably closely connected in time with the period of the 

Braintree Paradoxides beds. The conglomerate in which the pebbles 

occur is considered to be of Carboniferous age.

Various communications were made to the Boston Society of Natural 

History respecting the - Paradoxides fauna at Brain tree, by Messrs. 

Jules Marcou and C. T. Jackson in 1861 and 1862. From that time 

until 1869 little attention appears to have been given to the Braintree 

rocks. In the latter year Prof. N. S. Shaler 4 described the rocks in the 

vicinity of Boston, and referred to the argillites of Braintree, stating 

that they were deposited in deep water. In 1870 Dr. T. S. Hunt examined the rocks near Braintree, and stated that the unaltered argillites of Braintree, holding the Primordial fauna, were observed by Prof. 

Shaler and himself to rest directly upon a hard porphyrite felsite of 

the ancient series. He says: 5

The fact that the Primordial strata of Braintree have suffered no metamorphism is 

the more significant, since the beds of similar age in New Brnnswiclc and Newfoundland rest unconformably on crystalline strata supposed to belong to the same ancient 

series that underlies the Braintree bods, and are, like these, unaltered sand and mud 

rocks.

In 1875 Mr. W. W. Dodge 6 described the rocks at and about Braintree in the Boston Basin with great detail, and accompanied this with 

a discussion of the correlation of the Paradoxides beds with the various 

lower Paleozoic rocks of Europe.

In the same year, in some remarks on Massachusetts geology, Dr. T. 

S. Hunt 7 reaffirms his observation on the relations of the fossiliferous

'[Catalogue of State cabinet and notes on motamorphic rocksl 6th annual report of the Secretary 

of Massachusetts Board of Agriculture, etc., by Charles L. Flint, Boston, 1859, p. iv.

2 Trilobiton dor Primordial-fauna in Massachusetts. Neues Jahrb. filr Mineral., I860., pp. 429-431.

3 On fossiliferous pebbles of Potsdam rocks in Carboniferous c> ngliinerato north of Tall River, 

Massachusetts. Boston Soc. Nat. Hist., Proc., vol. 7, 1861, pp. 389-.'!'Ji.

4 0n the relations of the rocks in the vicinity of Boston. Boston Soc. Nat. Hist., Proc., vol 13, 18G9> 

pp. 172-178.

"On tho geology of the vicinity of Boston. Boston Soe. Nat. Hist., Proc., vol. 14, 1871, p. 48.

B Note« on the geology of eastern Massachusetts. Boston Soc. Nat. Hist., Proc., vol. 17, 1875, pp^ 

388-419.

'[Kemarks on Massachusetts geology.] Boston Soc. Nat. Hist., Proc., vol. 17, 1875, pp. 508-510.
76 THE CAMBEIAN. [BULL. 81.

rocks of Braintree and St. John, New Brunswick, to the subjacent 

crystalline Huronian strata.

The following year Prof. W. O. Crosby described the Geological Map 

of Massachusetts, and said: 1 «

Although the fossils characteristic of the Acadian group have been found at only 

one locality in Massachusetts, viz, Hayward's quarry, in Braiutree, yet most observers agree that the greater portion of the slates in the vicinity of Boston are probably 

of Primordial age; and I have so represented them on the map.

The strata referred to are then described in a general way.

In 1875 Prof. W. B. Eogers 2 announced the discovery of impressions 

suggestive of the fossil Lingula mentioned by him from Fall River, in 

pebbles of the conglomerate, at Newport, Rhode Island. The pebbles 

consist of a gray siliceous rock or quartzite.

The memoir of Prof. W. O. Crosby on the Geology of eastern Massachusetts, with its accompanying map, appeared in 1880. He says: 3

The Paleozoic rocks of eastern Massachusetts occur, as already indicated, only in 

limited basins or depressions excavated in the ancient crystalline formations. . . .

The most diligent search, continued for many years, by, in the aggregate, a small 

army of observers, has failed to bring to light, among the rocks of the Boston Basiu, 

more than one locality affording fossils. This is the celebrated slate quarry of the 

south shore of Hayward's Creek, in the extreme northeast corner of Braiutree.

Prof. Crosby 4 concludes that the Paradoxides bed in Braintree is the established base line for the stratigraphy of the Boston 

Basin ; and that all the rocks in the Boston Basiu above the Shawmut 

group, and including the Paradoxides bed, belong to one and the same 

essentially conformable series; although (p. 186) there is in the Boston 

 Basin essentially but one conglomerate and one slate, and the former 

underlies the latter. From this it follows that the slate is of Primordial age, and the conglomerate must be of the same age, or older. The 

conglomerate is stated to pass gradually into the slate, and a detailed 

description of these two formations is given as they occur in the Boston 

Basin. On the map a part of Nahant is colored to indicate the Cambrian slate. In the text he describes white and gray limestones that in 

texture are very compact and highly crystalline or saccharoidal. These 

have a thickness collectively of perhaps 20 feet. He assigns to the 

conglomerate a maximum volume not exceeding 1,000 feet; and considers that the greatest thickness of the slates cannot be much less than 

that of the conglomerate, though in some cases falling below 500 feet. 5

Dr. M. E. Wadsworth,6 in discussing the relation of the Qnincy granite to the Primordial argillite of Braiutree, states that Dr. Hunt was

1 Report on tbe geological map of Massachusetts, Boston, 1876, p. 40.

2 On the Newport conglomerate. Boston Soc. Nat. Hist., Proc., vol. 18,1875, p. 100. .

3 Contributions to the geology of eastern Massachusetts. Boston Soc. Nat. Hist., Occasional papers, 

No. 3,1880, p. 181,183.

«0p. cit., pp. 184,185. * Op. cit., p. 266.

6 On the relation of the Quiucy granite to the Primordial argillite of Braintree, Massachusetts. 

Boston Soc. Nat. Hist, Proc., vol. 21, pp. 274-277,1882.
 EASTERN MASSACHUSETTS. , 77

inistaken in regarding the granite as of Huronian age, as was Prof. Shaler 

in regarding it as a metamorphosed sedimentary rock. He says the 

argillite is surrounded by intrusive granite of a later age, thus adopting the view advanced by Dr. Hitchcock in 1832. In describing the 

&lates, he says they dip a little west of south at an angle of 55°, nearly 

as given by Mr. Lea. He thinks that, j udging from their writings, Profs. 

Rogers and Shaler based their conclusions regarding the dip of the 

 argillite upon its structural character. In another paper, published 

the following year, Dr. Wadsworth discusses the argillite and conglomerate of the Boston Basin, 1 and concludes from studies made by him that 

there are at least two distinct argillites. One like that underlying the 

conglomerate on Beacon street, Boston, and resembling in some of its 

characters the Paradoxides argillite at Braintree. The second is of 

coarser grain, often more decidedly arenaceous, and generally of a gray, 

lnlack, or reddish color, and forms the Somerville argillites (" Cambridge slates.") It is stated : 2

So far as wo have any evidence at present the oldest surface rocks in this basin 

are the argillites and the schists of allied character. Of these we only know the age 

of a very small area in Braintree and Quiucy. * * * Older rocks than the Braintree (Paradoxidos) argillites may exist, but of their existence we thus far have no

The discovery of fossils of Lower Cambrian age near North Attleborough, Bristol County. Massachusetts, by Prof. N. S. Shaler,3 located a 

second area of Cambrian rocks in eastern Massachusetts. He describes 

the geographic distribution and the character of the rocks, and in an 

accompanying paper in connection with Mr. A. F. Foerste gives a description of the fauna. As the description of the strata and the fauna 

is that which is given in our summary of the present knowledge of the 

rocks of eastern Massachusetts, it is here omitted,

In a review of the stratigraphic position of the Olenellus fauna by 

Mr. C. D. Walcott in 1889,4 it is shown that the Paradoxides fauna of 

Braintree, Massachusetts, of St. John, New Brunswick, and of southeastern Newfoundland, is super] aceut to the Olenellus fauna, and thus 

above the Olenellus fauna as found at North Attleborough by Prof. 

Shaler. This is presented more fully in a paper in the Tenth Annual 

Report of the Director of the U. S. Geological Survey.5

In a sketch of the physical history of the Boston Basin, Prof. W. O. 

Crosby6 mentions the old and more or less altered or metamorphic slates 

of the Braiutree quarry, and states it to be clearly established that the

1 Tho argillito ami conglomerate of the Boston Basin. Boston Soo. Nat. Hist., Proo., vol. 22, 1883, 

pp.130-133.

2 Op, cit., pp. 132,133.

3 On the geology of the Cambrian district of Bristol County, Massachusetts. Bull. Mus. Corap. 

Zo51. Harv. College, vol. 16, 1888, pp. 13-26.

4 Stratigraphic position of th'o Olenollus fauna in North America and Europe. Am. Jour. Sci., 3d 

eer., vol. 37, 1889, pp. 374-392 ; vol. 38, 1889, pp. 29-42.

6 Tho fauna of the Lower Cambrian or Oleuellus zone. 10th Ann. Rep. TJ. S. Geological Survey, 1890, 

pp. 509-7C3, plates 49-98.

B Physical History of the Boston Basin. Lowell free lectures, 1889-1890. Boston, 1889, pp. 22.
78 THE CAMBRIAN. [BULL. 81.

granite is eruptive through, and therefore newer than the Primordial 

slate. The evidence of the trilobites shows that the slates were formed 

very far back in geological time, and near the base of th& recognized 

geological formations. In a r6sum<§ of the geological history of the 

Boston Basin,1 a general description of the Primordial slates and quartzites and their physical relations is given.

In mentioning the discovery of fossils in the limestones at Nahant, Mr. 

A. F. Foerste correlated the Nahaut limestone with the red slates of 

North Weymouth, and concluded that they are stratigraphically beneath 

the Braiutree Paradoxides beds, and that the red slates of Mill Cove at 

North Weymouth are of Oleuellus age and beneath the Paradoxides 

strata.2

In 1889 Mr. A. 0. Lane described the geology of Nahant from a mineralogical standpoint,3 and in the following year Prof. J. H. Sears published a description of the stratified rocks of Essex County, which includes the limestones and associated slates of Nahaut. He mentions 

finding Hyolithesprinceps, Hyolithes communis var. emmonsi, Hyolithes impar, and Stenotheca rugosa.* He also discovered an outcrop of the Lower 

Cambrian limestone in a valley between Prospect Hill and Hunslow's 

Hill, in Eowley, in which fragments of Hyolithes occur.

PALEONTOLOGY. 

NEWFOUNDLAND.

The first announcement of the discovery of the Cambrian fauna in 

Newfoundland appears to be by Mr. J. W. Salter 5 in the description of 

Paradoxides bennettii. He referred the species to the " Lingula flags or 

Zone Primordiale."

From collections made by the Canadian Geological Survey Mr. E. 

Billings described in 18616 the fauna from the Cambrian strata on the 

north side of the Straits of Belle Isle, on the Labrador shore, at L'Ause 

au Loup, and assigned it to the horizon of the " Lower Potsdam," correlating it with the fauna found in Franklin County, Vermont, which is 

described in the same paper. The species described are Palwophycus 

incipiens, Archceocyathus atlanticus, Obolus labradoricus, Obolella chromalica, 0. (Kutorglna) cingulata, Conocephalites miser, Bathyurits senectus, 

B. parvulus, Salterella rugosa, 8. pulchella, and £ obtusa. The new

1 Op. cit., pp. 19-22.

2 The Paleoutological horizon of the limestone at Nahaut, Massachusetts. Boston Soc. Nat. Hist. 

Proc., vol. 24, 1889, pp. 261-263.

3 Geology of Nahaut. Boston Soc. Nat. Hist. Proc., vol. 24,1889, pp. 91-95.

4 The stratified rocks of Essex County. Essex Institute Bull., vol. 22, 1890, p. 32.

6 On the fossils of the Lingula flags or "Zone Primordiale." Quar. Jour. Geol. Soc., London, vol. 

15, 1859, p. 552.

 Paleozoic Fossils, vol. 1. Containing descriptions and figures of newer little known species of 

organic remains from the Silurian rocks. 1860-1805. Montreal, 1865, pp. 426. . (Of this volume pp. 

1-24 were issued in November, 1861; pp. 25-56 issued January, 1862; pp. 57-168 issued June, 1862; pp. 

169-344 issued February, 1865; pp. 395-416 published in Canadian Naturalist, vol. 5, 1860, pp. 301-324.)
WALCOTT.J PALEONTOLOGY NEWFOUNDLAND. 79

genera are ArchsBOcyathus, Obolella, Kutorgina, and Salterella. In 

reprinting, in 1865, the article published in 1861, Mr. Billings added 

a new species, Archceocyathus profundus ; and in the same year described 

Acrotreta gemma from near Portland Creek.

The mode of occurrence of the Cambrian section and fauna on the 

northwest coast of Newfoundland is given by Sir William Logan in the 

description of the geological section near Bonne Bay.1

From a collection of fossils from Newfoundland sent by Mr. Alexander Murray to Mr. E. Billings, there was described in 1865 Bathynrus 

gregarius=Solenopleura gregarius from the Paradoxides horizon of southeast Newfoundland.2 Subsequently he 3 described the fauna found at 

Great Bell Island and also " Fossils from the Menevian Group/' under 

which we find Obolella 9 miser, Straparollina remota, Hyolithes excellens, Agraulos socialis, A. strenuus, A.affinis, Solenopleura communis, Anopolenus venustus, Paradoxidestenellus, P. decorus, Iphidea, n.gen., Iphidea 

bella, Stenotheca pauper, Scenella, u. gen., Scenella reticulata. Also from 

the shalesand sandstones of Great Bell Island, Conception Bay : Eophyton linnceanum, E. julcesi, Arthraria antiquata, Lingula murrayi, Lingulella (?) affinis, L. (?) spissa, and Cruziana similis.

With the exception of Obolella f miser, Solenopleu ra communis, Stcno 

theca pauper, and Scenella reticulata the species described in 1872 were 

republished in the appendix to the report of progress of the Geological 

Survey of Newfoundland for 1881.

In 1878 Mr. J. F. Whiteaves described4 a new species of Liugula, L. 

billingsiana, from the shales of Kelley's Island, and republished Murray's geological section on Manuel's Brook, southeast Newfoundland, 

with a list of fossils collected there as follows : 1. Agnostus acadicus; 

2. Agnostus (sp. uiidet.); 3. Microdiscus punctatus ; 4. M. dawsoni; 5. 

Conocephalites tener; 6. C. baileyi; 7. G. orestes?; 8. Paradoxides 

sp. undet.), stating that Nos. 1,3,4, 5, t>, and possibly 7, are common to 

the Primordial slates of St. John, New Brunswick, and to the shales of 

Mauuel's Brook.

In 1887 when reviewing the Cambrian faunas of Cape Breton and 

Newfoundland Mr. G. F. Matthew5 described a new species from the 

Oleuellus zone, Solenopleura bombifrons, and identified from Mauuel's 

Brook Paradoxides sp., Agnostus gibbus (?), Agraulos socialis, and Hyolithes sp. From Trinity Bay he identified in addition to the species 

mentioned by Mr. Billings Eocystites sp., Agnostus Icevigatus, A. punctu1 Geological Survey of Canada; report of progress from its commencement to 1863. Montreal, 1803. 

pp. 805-867.

2 Paleozoic Fossils, vol. 1. Containing descriptions and figures of new or little known species of 

organic remains from the Silurian rocks. 1860-1865, p. 363.

3 On some fossils from the Primordial rocks of Newfoundland. Canadian Naturalist, new ser., vol. 

6, 1872, pp. 465-479.

4 Ou some Primordial fossils from southeastern Newfoundland. Am. Jour. Sci., 3d ser., vol. 10,1878. 

p. 226.

6 On the Cambrian faunas of Capo Breton and Newfoundland. Hoy. Soe. Canada Proc. and Trans., 

vol. 4, BOO. 4.1887, pp. 147-157.
80 THE CAMBEIAN. [BULL. 81.

osus, var., Agnosti of three other species, and Microdiscus punctatus. 

From Highland Cove in the same bay, Paradoxides davidis, Centraplvura loveni, Agnostus punvtuostis, var., A. brevifrons, A. Iwvigatus, A. 

acadicus, var. declivis.

In connection with the study of the stratigraphy of the Cambrian 

rocks of Newfoundland, the writer described' a number of species from 

the lower or Olenellus zone, and the middle or Paradoxides zone. 

From the former there were Obolella atlantica, Coleoloidest n. gen., 

Coleoloides typicalis, Hyolithes terranovicus, H. similis, Helenia, u. gen., 

Helenia bella, Microdiscus helena, Olenellus (M.) broggeri, Avalonia, n. 

gen., Avalonia manuelensis, Solenopleura harveyi and /S. howleyi. From 

the Paradoxides zone there was described the genus Karlia and the 

species K. minor. 2

In 1890 Mr. C. D. Walcott3 described Agraulos strenuus, var. nasutus, 

from MauuePs Brook.

NEW BRUNSWICK'AND CAPE BRETON.

The first description of the Cambrian fauna as found at St. John, 

New Brunswick, by Mr. C. Fred. Hartt 4 included the following species: 

Eocystites primccvus Billings, Linyula mattheici, Lingula, n. s., Obolella 

transversa, Discina acadica, Orthis biUingsi, Orthis, n. sp., Conocephalites 

baileyi, C. matthewi, C. robbi, G. orestes, G. elegans, C. ouangondianus, C. 

tener, C. aurora, C. thersites, G. gemini-spinosus, C. halli, G. quadratus, G. 

neglectus, G. formosus, Gonocephalites, n. sp. (?), Microdiscus dawsoni, 

Agnostus acadicus, Agnostus similis, Paradoxides lamellatus.

It appears that the Eocystites primccvus was submitted to Mr. Billings, 

to name the genus and species, in manuscript, and was printed in connection with Mr. Hartt's paper. The Paradoxides micmac, figured by 

Dr. Dawson at the close of Mr. Hartt's paper, was named by the latter 

in manuscript. The figure is a restoration, and no description accompanies it. In the report of Messrs. Bailey and Matthew 5 it is stated 

that Mr. E. Billings identified from the St. John group, in the Kenne. 

becasis Valley, fragments of Paradoxides and the pygidium of an 

Agnostus, three species of Conocephalites, one of Ellipsocephalus, one 

of Agnostus, what appeared to be a fragment of Salterella, and specimens of Paleeophycus of two or three kinds. Among the collections 

examined by Prof. J. F. Whiteaves for Professor Bailey6 there is a new

descriptive notes of new genera and species from the Lower Cambrian or Olenellus zone of North 

America. IT. S. Nat. Mus., Proc., vol. 12,1889, pp. 33-46.

2 Dascriptioii8 of new genera and species of fossils from tho Middle Cambrian. TJ. S.Nat. Mus. 

Proc., vol. 11,1889, pp. 441-446.

3 The fauna of the Lower Cambrian or Olenellus zone. 10th Ann. Kept. U. S. Geol. Stir., 1890, p. 654.

4 Fossil8 of tho Primordial or Acadian group at St. John. Dawson, Acadian Geology, 1868, pp. 641- 

657.

 Preliminary report on the geology of southern New Brunswick. Geol. Surv. Canacl., Rep. Prog., 

1870-1871,1872, p. 140.

"Report on the pre-Silurian (Huronian) and Cambrian or Primordial Silurian Rocks of Southern 

N»w Brunswick. Geol. Surv. Can. Kop. of Prog., 1877-78,1879, pp. 30, 31 DD.
WALCOTT.] PALEONTOLOGY NEW BRUNSWICK. 81

species of Agnostus and one of Hyolithes noted in association with 

other species described by Mr. Hartt.

In the year 1883 the first of Mr. Gr. F. Matthew's 1 memoirs on the 

fauna of the St. John group made its appearance. In this is given a 

brief historical review of the work that had already been done upon 

the fauna by Prof. Hartt, and a statement that from the collections made 

from time to time during the progress of the Canadian geological survey in New Brunswick Mr. Billings identified.fragments of Ellipsocephalus and Salterella and the remains of two species of Hyolithes. 

Besides these, there are the supposed plant remains of the genera Palseophycus, Eophyton, etc., of the higher divisions of the St. John 

group.2 Mr. Matthew made large collections, which were destroyed by 

the great fire at St. John in the spring of 1877. His published studies 

were based upon new material collected subsequently to that date.

In the first memoir we find that he recognized three well defined species of Paradoxides and six varieties, as follows : Paradoxides lamellatits 

Hartt; P. lamellatus var. loricatus Matthew; P.acadicus Matthew; P. 

cteminicus Matthew; P* eteminicus, vars. suricoides, breviatm, quacoensis, 

malicitus, and pontificalis.

A review by Mr. C. D. Walcott 3 of the typical collections upon which 

Prof. C. F. Hartt based his species, led to a revision of the genera and 

species, with the following results :

Lingula matthewi ........= Acrothele matthewi.

Discina acadica..........= Palieacmea (?) acadica.

Theca acadica ...........= Hyolithes acadica.

Agnostus similia .........= Agnostus acaclicus.

Microdiscus pulchellus...= Microdiscus puuctatus Suitor. 

Couocephalites matthewi = Couocoryplie matthewi.

gemini-spiuostis .... = Couocoryplie matthewi.

baileyi ............. .= Couocoryphe baileyi.

elegaus....,.........= Conocoryphe elegaus.

robbi................=^ Ftyclioparia robbi.

foruiosus...... .......= robbi.

ouaugondianus ......= ouaugondiana.

aurora.... ...........= ouangondiana var. aurora.

quadrata ............= quadrata.

orestes..........--...= orestes.

thersitos ..............= orestes ~var. thersites.

teuer ................= teuer.

neglectus ............= teuer.

The genus Harttia and species, Harttia matthcwi, is proposed for a 

small patelloid form of gasteropod. Mr. Matthew.was requested to give 

names to the new species, other than the preceding, and he proposed 

Lingula f daiosoni (p. 15), Hyolitlies danianus (p. 20.), Hyolithes micmac

1 Illustrations of the fauna of the St. John group. Eoyal Soc. Canad., Proc. aiid Trans., vol. 1, sec. 4, 

1883, pp. 87-108. Supplementary section, pp. 271-279.

2 0p. cit., p. 89.

*0n the Cambrian faunas of North America; preliminaiy studies. TJ. S. Geol. Snrv. Bull., No. 10, 

vol. 2,1884, pp. 283-354, plates.

Bull. 81 6
82 THE CAMBRIAN. [BULL. 81.

(p. 21), Conocoryplie ivalcotti (p. 30). The subgeiius Salteria was proposed by the author to include the Gonocephalites baileyi l of Hartt.

All of the species were figured arid described, with the exception of 

Conocoryphe ivalcotti. This included figures of the three species of 

Paradoxides, P. lamellatus Hartt, P. acadicus Matthew, and P. etenlinicus 

Matthew.

Some of the results of Mr. Gr. F. Matthew's studies are given in two 

papers read before the British Association for the Advancement of Science at the Montreal meeting in 1884. .In one he refers to the geological age of the Acadian fauna, and correlates it with the fauna of the 

St. John group and that of the Solva group of Wales. In the second 

is given a description of the development of Ctenocephalus mattliewi and 

other species of the genus Couocoryphe.2

In Mr. Matthew's second memoir on the fauna of the St. John group,3 

presented to the Koyal Society of Canada in 1884, additional notes are 

given of the Paradoxides acadicus and P. lamellatus. He proposes the 

name Paradoxides micmac for a large species, which he thinks is prob. 

ably the one figured in Acadian Geology.4 The original species to 

which Mr. Hartt intended to apply the name is unknown. The Conocephalites matthewi of Hartt is referred to the genus Cteuocephalus of 

Corda. A detailed description is given of the species, and also of the 

various stages of its growth, as found in the St. John slates. Conocoryplie baileyi, C. elegans, and G. walcotti are described and figured. In the 

description of the plate 5 the subgeneric name Hartella is placed after 

Ctenocephalus and Bailiella after Conocoryphe.

In 1885 Obolella transversa Hartt was referred by Mr. 0. D. Walcott 

to the new genus Liunarssonia, together with the closely allied Meuevian species, Obolella sagittalis. G

In a paper read before the Natural History Society of New Brunswick in 1885, Mr. Gr. P. Matthew stated7 he had found some Pteropods 

that appeared to have several distinct septa at the base of the tube. 

He sent them to Prof. Hyatt, who wrote that the aspect of the siphon 

is due to the compression of the sharper against the flatter side. The 

form of the sutures favors this impression. " These fossils with their 

distinct septa are startlingly similar to certain forms of Nautiloidea, 

but there is no siphon. They, however, confirm Yon Jhemig's and my 

opinion that the Orthoceratites and Pteropods have had a common, but 

as yet undiscovered, ancestor in ancient times."

1 Op. oit., pp. 31, 32.

2 The geological age of the Acadian fauna. The primitive Conocoryphean. British Association 

Hep., 54th meeting, 1884, pp. 742-743. The geologic age of Acadian fauna. Geol. Mag., new ser., decade 

3, vol.1,1884, pp. 470-471.

3 Illustrations of the fauna of the St. John group, continued; on the Conocoryphea, with further remarks on Paradoxides. Koyal Soc. Canada, Trans. and Proc., vol. 2, sec. 4,1885, pp. 99-124.

4 0p.cit.,p.l01. 6 0p.cit.,p.l24.

6 Paleontologic Notes. Am. Jour. Sci., 3d ser., vol. 29,1885, p. 115.

7 An outline of recent discoveries in the St. John group. New Brunswick Nat. Hist. Soc. Ball.,No. 4, 

1885, p. 102. .
WALCOTT.] PALEONTOLOGY NEW BRUNSWICK. 83

The third contribution by Mr. Matthew,1 presented to the Royal Society of Canada in 1885, treats of the Protozoa, Hydrozoa, Brachiopoda, 

Pteropoda, Gasteropoda, Pliyllopoda, Ostracoda, and some of the Trilobtta.

Of tlie Protozoa, Archceocyatlms f pavonoides, Protospongia? minor, 

P. 1 minor var. distans, the new genus Eocoryne and the species Eocorync geminum are described. Of Hydrozoa Dendrograpsus ? primordialis 

Protograpsus, n. g., with the species Protograpsus alatus. But one species of the Echinoclermata is mentioned, Eocystites primcevus of Billings. 

The new forms of Brachiopoda are: Lingulella $ inflata, I>. linguloides, 

Acrotrcta baileyi, A. f gulielmi, Kutorgina latourensis, K. f pterineoides, 

Orthis quacoensis. Of species previously described Lingulella dawsoni, 

Linnarssonia transversa Hartt, Linnarssonia misera Billings, AcrotheU 

matthc'ioi Hartt, and Orthis billingsi Hartt, are described and illustrated.

Among tlie Pteropods the new subgenus Camerotheca .is proposed, 

and the species Hyolithes (Camerotheca) gracilis, If. (C.) danianus, and 

II. (C.) micmac are described and illustrated. The genus Diplotheca 

includes JJiplotheca hyattiana and the variety caudata; also Hyolithes 

acadicus of Hartt, and its varieties, sericea, obtusa, and crassa.

The Gasteropoda include a notice of the genus Stenotheca and the 

description of the new species, Stenotkeca hiclcsiana, S. concentrica, 8. radiata, S. nasuta, and S. triangularis. The subgenus Parmophorella is 

proposed to include the original species, Discina acadica Hartt. Stenotheca acadica and Harttia matthewi Walcott are described and illustrated. To the Phyllopoda (?) the new genus Lepiditta, with the species 

L. alata and L. curta, and the new genus Lepidilla, with the species 

Lepidilla anomaly are referred. Mr. Matthew says that these forms 

are very minute, and belong either to laraellibranchs or Phyllopods. 

The Ostracod Crustaceans include the new genera Hipponicharion and 

Beyrichoua. One species is referred to the former genus, H. eos, and 

two to the latter, B. papilio and JB. tinea. To the 'genus Primitia lie 

refers one new species, P. acadica.

The Trilobita include the new species of Agnostus, A. regulus, A. 

vartitus, A. vir, A. vir. var. concinus, A. tessella, A. unibo, A. obtusilolus, 

and A. acutilolus. Agnostus acadicus Hartt is described and figured and 

the variety declivis proposed. Microdiscus ptdchella Hartt is placed as 

a variety of M. punctatus Salter, and a new variety, precursor, is proposed to be included under punctatus. M. daivsoni Hartt is also described 

and figured. Of the larger forms of the Trilobita, Agraulos (?) articeplialus is proposed, Solenopleura acadica of Whiteaves is figured and 

described for the first time, and Paradoxides abenacus is proposed as a 

new species. A redescription of Paradoxides micmac and the proposal 

of a variety, suricus of P. acadicus concludes the references to previously described species.

1 Illustrations of the farina of the St. John group, continued. No. III. Descriptions of new genera 

and species (including a description of a new species of Soloiioploura toy J. F. Wniteaves). .Royal Soc. 

Canada, Trails, vol. 3, sec. 4,1886, pp. 29-84. (Proc. for 1885.)
84 THE CAMBRIAN. [BULL.81.

In a synopsis of the fauna in Division 1 of the St. John group, Mr. 

Matthew1 notes the occurrence of thirty genera, sixty-five species, and 

twenty-one varieties of fossils. He states that in a higher horizon in 

the Kennebecasis Bay area he has ibund the following association of 

species: z

Anopoliiius 1? sp. Agnostus (cfr. Nathorsti, Brogg).

Paroboliua? sp. A. (cfr. parvifrons, Linrs.)

Anomocare? 2 sp. A. uiubo.

Ptycboparia, % sp. A. acadicus Hartt, var.

Agranlossocialis Bill., var. Hyolithes, sp.

Microcliscus pnnctatns Salter, var.? Linnarssouia transversa Hartt, sp.

Agnostus acutilobus (cfr. gibbus).

In some preliminary notes on the higher fauna 3 he says that 

The heavy band of black slates which runs through the center of the city of Saint 

John has yielded the following species, contained in calcareous nodules:

Cteuopyge (cfr.) spectabilis Brogg. Kutorgina (cfr.) cingulata Bill. 

Orthis (cfr.) leuticularis Dal. Kutorgina?

Those indicate a horizon in the upper part of the Lingula flags. 

A series of slates are exposed along the north side of the Kennebecasis Basin, whose 

fossils indicate that they also pertain to the upper part of the Cambrian system: 

Conocepbalites, a species with broad Kutorgina (?),sp. 

free cheek and flaring genal Lingulella (cfr.) lepis Salter. 

. spine. Lingulella, sp. 

Ptychoparia, a small species. Eophyton linnajanum Torrell, var, 

Agnostus (cfr.) pisiformis Ang. Eophytera, sp. 

A. (cfr.) richmondensis Wal. Arthraria, sp.

In a note to the American Journal of Science Mr. Matthew 4 states 

that he has found Olenellus (?) Icjcrulfi in the Kenuebecasis Eiver 

Basin in baud c and d of his Division 1; and that the same species occurs 

in the Cambrian beds of Newfoundland. Upon this reported discovery 

Mr. S. W. ITdrd 5 endeavored to show that as the species was found at 

the base of the St. John Paradoxides beds and at the base of the Swedish Paradoxides beds it was a true Paradoxides, and therefore did not 

influence the question of the stratigraphical position of the Olenellus 

fauna in North America.

In an abstract of a paper on the Cambrian faunas of Cape Breton and 

Newfoundland in the Canadian Eecord of Science, vol. 2,1886, pp. 255- 

258, that preceded the main report in the Eoyal Society of Canada 

Transactions,6 Mr. Or. F. Matthew points out that the slates of Mira 

Eiver, Cape Breton, contain several species of trilobites, which show 

that these measures are in the upper part of the Olenus zone or Lingula 

flags of Great Britain. The species observed were Peltura scarabeoides

1 Synopsis of the fauna in Division 1 of the St. John group, with preliminary notes on the higher 

faunas of the same group. New Brunswick Nat. Hist. Soc., Bull. 5,1886, pp. 25-31.

2 0p.cit.,p.29. 3 0p.cit.,p.30.

"Note on the occurrence of Olenellus (?) kjerulfiin America. Am. Jour. Sci., 3d ser., vol. 31,1886, p. 472.

6 Note on the a^e of the Swedish Paradoxides heds. Am. Jour. Sci., 3d ser., vol. 32,1886,pp. 473-47G.

6 On the Cambrian faunas of Cape Breton and Newfoundland. Eoyal Soc. Canada, Proo. and Trans.? 

vol. 4, Sec. 4,1887, pp. 147-157.
WALCOTT.] PALEONTOLOGY NEW BRUNSWICK. 85

Wahl., SpJtccroplitlialmus alatus, and Agnostus pisiformis. There was 

also a small Lingulella similar to that which characterizes the upper 

flags of the St. John group, and an Orthis similar to Orthis lenticularis 

of Dalnian.

In discussing the evidence afforded by the smaller-eyed trilobites of 

Division 1 of the St. John group, Mr. G. F. Matthew l speaks of their 

bearing on the origin of the Cambrian fauna. He also gives a list of 

fossils known to him at that date from Division 1 of the St. John series. 

The total is thirty genera, sixty-five species, and twenty-one varieties, 

.the same as in the paper previously mentioned in the synopsis of the 

fauna of the St. John group.2 Mention is made by Mr. Matthew of ad. 

ditional species from the St. John group in 1888.3 In the measures on 

the St. John River corresponding to those of Band B in Division 1 of 

the'St. John Basin, a calcareous organism that may be referred to Oldhamia has been found. It resembles 0. antiqua, but branches less freely. 

In the same sandstone occurs an elegantly ornamented Lingulella (?) of 

peculiar form. Mr. Matthew compares it with Lingula "I favosa of the 

Eophyton sandstones of Sweden. In Division 2 of the St. John group 

were found several genera of seaweeds, among which are two graceful 

species related to Taonurus or Spirophyton; also fragments of bodies 

of a small crustacean that is probably a Hymenocaris. In a paper published soon after on the "Classification of the Cambrian Rocks of Acadia," Mr. Matthews states 4 that the Lower Potsdam of Billings, or 

Georgian of Mr. Walcott, is found in the island of Cape Breton, where 

the fossils areBathyurus (sub-genus?), Orthisina, Orthis, and Hyolithes 

princeps. Remarks upon the affinities of the characteristic genera of 

the Georgian and other portions of the Cambrian fauna occur in this 

paper.

Mr. Matthew presented Part iv of his illustrations of the fauna of 

the St. John group to the Royal Society of Canada in 1887.5 The 

first species described is the great Paradoxides regina, one of the 

largest trilobites yet discovered in the Cambrian rocks. This is 

followed by a description of "The smaller trilobites with eyes." An 

undetermined species is referred to the genus Ellipsocephalus, and 

Agraulos? wliitfieldianus is described with its variety compressa. The 

subgeuus Strenuella is proposed, with the species Strenuella ? halliana 

as its type. A discussion of the genus Liostracus of Angelin is 

followed by descriptions of Liostracus tener Hartt, L. ouangondianus 

Hartt, and varieties immarginata, aurora, gibba, and plana, and a

1 Illustrations of the fauna of tbe St. John group, No. IV. Pt. I: Description of a new species of 

Paradoxides (Paradoxides regina). Part 2: The smaller trilobites Avith eyes (Ptychoparidze and Ellipsocephalidce). Royal Soc. Canada Traus., vol. 5, sec. 4,1888, pp. 115-1C6.

"Illustrations of the futma of the St. John Group. Canadian Rec. Sci. vol 2, 1887, p. 3G1.

3 On the basal series of Cambrian rocks in Acadia. Canadian Record Science, vot 3,1888, pp. 28, 29.

4 Canadian Rec. Sci., vol. 3,1888, p. 74.

B lllustratations of the fauna of the St. John group, No. IV. Pt. 1. Description of a new species of 

Paradoxides (Paradoxides regina). Pt. 2. The smaller trilobites with eyes (Ptychoparidffl and Ellipsocephalidffi). Royal Soc. Canada, Traus., vol. 5, sec. 4, 1888, pp. 115-166.
86 THE CAMBRIAN. [BOLL. a.

notice of the development of the young of this species. Under Ftychoparia, Liostracus linnarssoni Brogger is ' identified from the St. 

John series. For the narrow form he proposes the variety alata, and 

this is followed by a description of the development of the young. To 

the genus Solenopleura of Angeliu he refers the Gonocephalites robbi of 

Hartt, and gives a description of the development of the young as far 

as known to him. A more extended description of Solenopleura acadica 

of Whiteaves is given, and the variety elongata proposed.

In the second paper by Mr. Matthews on the classification of the 

Cambrian rocks in Acadia1 the species Obolus pulcher is described 

from the base of Band B of division 1 of the St. John group. In the 

middle of the band Mr. Matthews recognized an Agraulos and at the 

base an Ellipsocephalus. This paper also contains a discussion of the 

Olenellus fauna as found in Nevada. In a paper read later in 1889, 

entitled " On the Cambrian Organisms in Acadia,"2 Mr. Matthew states 

that he has found in this lower series beneath the Paridoxides zone a 

species that recalls Fucoides circinnatus (p. 384), the Obolus which was 

described later, and undoubted examples of Platysolenites of Pander. 

In mentioning the fauna and flora of the Paradoxides beds, he says the 

basket sponges and the rod-like sponges (?) are common to both this and 

Series B. In all the fine layers of this band species of Protospongidte 

may be found, but no examples of the typical Protospongia of the Paradoxides beds have been observed. A new species of Obolus and three 

species of Liugulella are mentioned as being described in the paper, and 

the Algae are represented by several different types, among which are 

a Buthotrephis and a microscopic form parasitic on the latter organism. 

There are also some quite small oval forms, resembling Hydrocystium, 

which may have been algoid. Among the new species of the Paradoxides beds is a little Platyceras. He says that Paradoxides pontificalis is 

found to be a narrow, and P. micmac a broad form of Paradoxides liiclcsi 

of Wales (p. 385). From stage 2, the Olenus beds, he reports abundant remains of a large Protospongia, including Protospongia fenestrata 

of Salter, and P. (?) major of Hicks, and another large species. From 

the fossils which appear to have been placed in the upper part of division 2 are some that have been found in Kennebecasis Basin of the 

Cambrian rocks. These are Leptoplasti, allied to L. stenotus of Angelin, Agnostus pisiformis, var. and Agnostus nathorsti, var. From 

division or stage 3, the Peltura beds, he mentions two species, Ctenopyge (cf. G. flagillifer and G. spectabilis), Orthis lenticularis, and a Kutorgina. At the bottom of the division Lingulella lepis and another 

large species. L. ampla, var.? are found. These beds are correlated with 

beds of Cape Breton containing species of Peltura, etc. (p. 386).

In a papes by Mr. Matthew, entitled " How is the Cambrian divided 1

1 Canadian Eecord Science, vol. 3, 1859, pp. 303-315. * Ibid., pp. 383-387.
WAT.COTT.] PALEONTOLOGY NEW BRUNSWICK. 87

A plea for the classification of Salter and Hicks," 1 a comparison of the 

genera of the different horizons of the Oambria.ii is made.

In tbe full paper on the Cambrian organisms of Acadia, published in 

1890, Mr. Matthew describes the strati graphic position of the fauna that 

he considers beneath the Paradoxides beds, and compares it with the 

lower Cambrian fauna of Sweden and Russia. The new genera and 

species described are: 2

Pbycoidella, n. g., p. 144. 

Pbycoidella stichidifera n. sp., p. 144. 

Palajocborda setacea n. sp., p. 145. 

Hydrocytium (?) silicula n. sp., p. 146. 

Microphycus n. g., p. 146. 

Microphycus catenatus n. sp., p. 146. Monadites n. g., p. 147. 

Monadites globulosus n. sp., p. 147. 

Monaditcs pyriformis n. sp., p. 147. 

Monadites nrceiformis n. sp., p. 147. 

Radiolarites n. g., p. 148. 

Radiolaritos ovalis n. sp., p. 148. 

Plocoscyphia (?) perantiqna n. sp., p. 148. 

Astrocladia(?) elongata n. sp., p. 148. 

Astrocladia (?) elegans n. sp., p. 149. 

Astrocladia (?) virguloides n. sp., p. 149. 

Dichoplectella n. g., p. 149. 

Dichoplectella irregnlaris n. sp., p. 149. 

Hyalostolia minima n. sp., p. 150. 

Obolns (?) major n. sp., p. 155. 

Lingulella inartinensis n. sp., p. 155. 

Leperditia veutricosa n. sp., p. 159. 

Leperditia steadi n. sp., p. 160.

JTe also describes and illustrates:

Bnthotrophis antiqua Brongn., p. 144. 

Platysolenites antiqnissimus Eiclvw., p. 150. 

Obolus pulclier Mattli., p. 151. 

Volbortbella tennis Schmidt, p. 156. 

Psammicbnites gigas Torrell, p. 157. 

Arenicolites lyelli Torrell, var. minor, p. 159.

In a note at the close of tue descriptions it is stated that he has 

learned that a suggestion made by him in reference to Olenelhis Icjerulfi 

has met with acceptance from a number of naturalists and the generic 

name Holmia is proposed for Olcnellus Ttjerulfi? Mention is made of the 

relations of the genera Olenellus, Olenoides, and Mesonacis.

In his fifth contribution to the illustrations of the fauna of the St. 

John group Mr. G. F. Matthew describes the folio wing new genera and 

species: 4 Platyceras aperta, n. sp., p. 132, Agraulos (?) lioloveplialus, n. 

sp., p. 138, Medusiclinites, n. gen., p. 143, with five varieties, Lingu1 Am. Geologist, vol. 4,1889, pp. 139-148.

2 On Cambrian Organisms in Acadia. Royal Soc. Canada, Trans., vol. 7,1890, sec. 4, pp. 135-162. 

8 Op. cit.,p. ICO.

4 Illustrations of the fauna of the St. John group No. V. Roy. Soc. of Canada, Trans., vol.8, 1891, 

pp, 130-160, pis. 11-16.
88 THE CAMBEIAN. [BULL. 81.

lella starri, n. sp., p. 146, Lingulella radula, n. sp., p. 147, jEoichnites, 

n. geu., p. 148, Ctenichnites, n. gen., p. 15L, Cteniclmites ingens, n. sp., 

p. 151, Frazna ramosa, n. sp., p. 159, Arenicolites brevis, n. sp., p. 159, 

Goniadichnites, n. gen., p. 160, Goniadichnites trichiformis, n. sp., p. 160, 

Monocraterion magnificum, n. sp., p. 161.

In addition to the preceding Mr. Matthew has remarked upon several 

genera and species that have been previously described from the Cambrian rocks. They include: Eocoryne geminum Matt., p. 130, Lepidilla 

anomala, Matt., p. 130, Orthis and Orthisina, p. 131, Stenotheca Salter, p. 

132, Stenotheca concentrica, Matt., p. 133, var. radiata Matt., p. 133, 

Stenotheca triangnlaris Matt., p. 134. In his remarks upon the genus 

Stenotheca he concludes that the type species is not a molluscan shell, 

but should be referred to a Phyllopod crustacean. This includes the 

typical form, but does not include Discina acadica, of Hartt, as the latter 

is a patelloid gasteropod. Conocoryphe walcotti Matt., p. 134, Concoryphe baileyi Hartt, p. 135, Paradoxides lamellatus Hartt, p. 135, Paradoxides micmac, var., pontificalis Matt., p. 136, Agraulos (?) whitfieldianus 

Matt., p. 138, Agraulos socialis Bill., p. 138, Medusitesprinceps Torrell, p. 

140, Medusites radiata Fathorst, p. 141, Medusites costata, p. 142, Eoiclinites linncvanus Torrell, p. 148, Psammiclmites Torrell, p. 157, Fraina, 

Eoualt, p. 158, Monocraterion Torrell, p. 160, Monocraterion tentaculatum, 

p. 161, Histioderma hibernicum, p. 162.

EASTERN MASSACHUSETTS.

The first description of a fossil from the Cambrian rocks of eastern 

Massachusetts is that of Paradoxides harlani, by Dr. Jacob Green,1 from 

specimens sent to him by Dr. Eichard Harlan, who supposed they came 

from Trenton Falls, in the State of New York. It was not until 1856 2 

that the true horizon from which the specimens came was discovered. 

In making the announcement of the discovery Prof. Bogers quoted 

from Barrande on the distribution of the genus Paradoxides, and stated 

that he considered the specimens from Braintree, 10 miles south of 

Boston, to be identical with the Paradoxides harlani described by Green 

in 1834. He says the fossils in the Braintree quarry are in the form of 

casts, some of them of great size and lying in various levels in the 

strata, and that as far as he could observe they all belong to one species and agree more closely with Barrande's Paradoxides spinosus than 

with any other form known to him. A fine figure of Paradoxides liarlani was published by Prof. Eogers,3 in his final report of the geological 

survey of Pennsylvania, under the name of P. spinosus.

Mons. J. Barrande, in referring to the discovery of Paradoxides in 

the slates of Braintree,4 institutes a comparison of the specimens from

1 Descriptions of some new North American triloMtes. Am. Jour. Sci., vol. 25,1834, p. 336.

2 Proofs of the Protozoic age of some of the altered rocks of eastern Massachusetts, from fossils 

recently discovered. Am. Acad. Proc., vol. 3,1856, pp. 315-318. 

8 The Geology of Pennsylvania, Philadelphia, 1858, vol. 2, p. 816. 

4 Trilobiten der Primordial-fauna in Massachusetts. Neuos Jahrb. for 1860, pp. 429-431.
WALCOTT.] PALEONTOLOGY EASTEKN MASSACHUSETTS. 89

there and Paradoxides spinosus from Bohemia, and concludes that P. 

Jiarlani is a synonym for P. spinosus.

In 1861 Prof. Jackson1 exhibited a small trilobite from Braintree of 

the species Paradoxides harlani, stating that it seemed identical with 

forms from Newfoundland described as Paradoxides lennetti from St. 

Mary's Bay. In a foot-note accompanying a paper on the geology of 

the vicinity of Boston, by Dr. T. S. Hunt,2 the writer says:

Mr. Billings informs me that he regards the Paradoxides lennettii (Salter) from 

Newfoundland as identical with the Paradoxilles Uarlani (Green) from Braintree.

A number of collectors obtained specimens of Paradoxides harlani 

from the Braintree beds, but it was not until 1861 that a notice of other 

species appeared. Mr. Albert Ordway 3 stated at a meeting of the Boston Society of Natural History that he had found a fragment of a trilobite which he referred to the genus Ellipsocephalus. He also reported 

finding a distinct fucoidal impression which shows three branches0, each 

about 4 inches long, but not sufficiently well marked to aiford any evidence as to its nature. Mr. Ordway also published a figure of a head 

of Paradoxides harlani when comparing that species with Paradoxides 

spinosus, Boeck., considered by Barrande identical with P. harlani.4

In his notes on the geology of eastern Massachusetts Mr. W. W. 

Dodge 5 reviews the then existing information in relation to the fauna 

of the Paradoxides zone of Braintree the Braintree slates mentioning 

Paradoxides harlani and a few obscure traces of fossils found at thatlo. 

cality. A general description of the Cambrian fauna of Wales is given 

in this connection.

The second described species from the Paradoxides beds of Braintree 

is Arionellus qiiadrangularls by Prof. E. P. Whitfield.6 This is probably 

the species of Ellipsocephalus referred to by Mr. Ordway.

A review of the fauna of the Braintree argillites by Mr. C. D. Walcott 7 included a mention of the species previously described, aud a description of a new Pteropod, HyolitJies shaleri, and a new species of 

trilobite, Ptychoparia rogersi. The species described by Prof. Whitfield as Arionellus quadrangularis was referred to the genus Agranlos.

Under the title of " Preliminary descriptions of North Attleborough 

fossils" Messrs. N. S. Shaler and A. F. Foerste 8 made the most important contribution to the Cambrian fauna of Massachusetts since the 

discovery of Paradoxides harlani. They identified the fauna as that

1 [On a trilobite from Braintree.] Boston Soc. Nat. Hist., vol. 8,1861, p. 58.

2 Boston Soc. Nat. Hist. Proc., vol. 14,1871, p. 48.

3 On the occurrence of other fossil forms at Braintree, Mass. Boston Soc. Nat. Hist. Proc., vol. 8, 

1801, pp. 5,6.

<0p.cit.,p. 3.

8 Notes on the geology of eastern Massachusetts. Boston Soc. Nat. Hist. Proc., vol. 17,1875, pp. 

405-407.

"Notice of some new species of Primordial fossils in the collections of the Museum, and correction 

of previously desoribt>d species. Am. Mns. Nat. Hist., Bull., vol. 1,1884, p. 147.

7 On the Cambrian Faunas of North America; preliminary studies. TJ. S. GeoL Surv. Bull. No. 10, 

vol. 2,1884, pp. 323-329. Separately paged, pp. 43-49.

 Bull. Mus. Comp. Zool., Harv. College, vol. 16, 1888, pp. 27-39.
90 THE CAMBRIAN. [BULL. 81.

of the Olenellns zone, as found in the vicinity of Troy, New York. The 

species described are:

Obolella crassa, var. H. commuuis var. eminonsi.

Obolella (?) H. americanus.

Fordilla troyensis. H. princeps.

Lamellibranch (?) H. billingai.

Scenella reticulata. Hyolitbellua mi cans.

Stenotheca rugosa, var. paupera. Salterella curvatna.

S. rugosa var. abrupta. Ariatozoe.

S. curvirostra. Microdiocus bellimarginatus.

Platyceras primsevum. M. lobatus.

Pleurotomaria (Raphiatoma) attle- Paradoxidea walcotti.

borensis. Ptychoparia mucronatns.

Hyolithes quadricostatus. Ptychoparia attleborensia.

Of these, two genera Pleurotomaria and Paradoxides have not 

heretofore been found in a strongly marked Olenellus zone fauna. A 

comparison of Paradoxides walcotti with specimens of Olenellus asaphoidcs from Troy, New York, of the same size, show them to be generically, if not specifically, identical. This removes Paradoxides from the 

Olenellus fauna.

Under the view that the Olenellus fauna preceded the Paradoxides 

fauna Prof. Shaler 1 speaks of Paradoxides walcotti as the surviving 

member of the series, and says the occurrence of the genus indicates 

close affinities with the Braintree Cambrian horizon. He made careful 

search for indications of the stratigraphic relations of the North Attleborough and Braintree section but without success. In mentioning the 

Braintree locality it is stated that a number of distinct remains occur 

near the Neponset Eiver, and the beds have much the same aspect and 

are apparently about the same distance from the syenites as those at 

Braintree.2

A notice and description of the fauna found at North Attleborough 

from the Olenellus horizon, was followed in 1889 3 by the announcement 

of the discovery of Hyolithes in limestone near East Point, Nahant. 

Mr. Foerste correlates the limestone and associated shales with those 

of North Attleborough, and states that the species of Hyolithes appears 

to be the same as that found at North Attleborough. He proposes the 

name of Hyolithes incequilateralis. From a study of the type specimens 

the writer believes it to be identical with H. communis var. emmonsi.

As now known, the entire Cambrian fauna from eastern Massachusetts includes from the Paradoxides or Middle Cambrian zone four 

genera and four species, and from the Olenellus or Lower Cambrian 

zone, twelve genera and nineteen species.

1 On the geology of the Camhrian district of Bristol County, Massachusetts. Bull. Mns. Comp. Zool., 

Harv. College, vol. 16, 1888, p. 21.

2 Op. cit., p. 23.

3 Foerste, A. F. The paleontological -horizon of the limestone at Nahant, Massachusetts. Bt>aton 

Soc, Nat. Hist., Proc., vol. 24,1889, pp. 261-263.
WALOOTT.J NORTHERN APPALACHIAN DISTRICT. 91 

APPALACHIAN PROVINCE.

The Appalachian Province includes the outcrops of Cambrian strata 

on the line of the Appalachian system of mountains, from the lower 

St. Lawrence Valley on the north, to Georgia and Alabama on the 

south.

For the purpose of presenting the historical data the province will 

be divided as follows:

A. Northern Appalachian district. 

B. Southern Appalachian district.

NORTHERN APPALACHIAN DISTRICT.

The northern Appalachian district includes the Hudson River and 

Lake Oliamplain area east of the river and lake and an extension 

northeastward into Canada, as far as the vicinity of Cape Rosier on 

the St. Lawrence River.

The Hudson River and Lake Champlain area will first be considered. 

It includes the strata referred to the Cambrian, found on the western 

slope of the Green Mountains, the foothills and the more level country 

stretching westward toward the Hudson River and Lake Cbamplain.

The earliest reference in the literature to a distinct formation that is 

now referred to the Cambrian is found in a description of the geology 

of western Massachusetts and eastern New York. On this account this 

formation, the " Granular Quartz," will be treated historically as it 

has been mentioned by authors in Massachusetts, New York, and Vermont, until the year 1861, when its history will be carried forward with 

that of the "Red Sandrock" and the "Georgia Slates," with which 

it was then correlated.

GllANULAK QUARTZ.

The first differentiation of a formation referred to the Lower Cambrian in America was made by Prof. Amos Eaton in 1818. l Prior to 

that time Mr. William Maclure, the pioneer of systematic geology in 

America, published a map with descriptions of the rocks of the Eastern 

United States, in which all the strata now referred to the Cambrian 

system in the Appalachian range were included in the Transition series. 

On his first map 2 the Transition rocks are represented as extending 

from Hudson, in the valley of the Hudson, south to the vicinity of 

Poughkeepsie, and thence south west throughout New York, New Jersey, 

Pennsylvania, Virginia, eastern Tennessee, northern Georgia, and 

into Mississippi. On the map accompanying a later work 3 the Trausi1 An index to the geology of tho Northern States, with atransverso section from Catskill Mountain 

to the Atlantic. Leicester, 1818, pp. 62.

2 Observations on the geology of tho United States explanatory of a geological map. Am. Phil. Soc. 

Trans., vol. 0,1809, pp. 411-428, map.

3 Observations of the geology of the United States; with remarks on tho probable effects that may 

be produced by the decomposition of the different classes of rocks ou the nature and fertility of soils. 

With a map and two plates. Am. Phil. Soe. Trans., new ser., vol. 1,1817, pp. 1-91. 
92 THE CAMBRIAN. [BULL. 81.

tion rocks are extended north into the valley of Lake Charnplain as far 

as the Canadian border. On the south they terminate in Georgia a 

short distance south of the Tennessee line. 1

In his first publication on the rocks between the Catskill Mountains 

west of the Hudson Eiver and the Atlantic Ocean, Prof. Amos Eaton2 

separated the " Granular Limestone and Quartz " as No. 2 of the section, and an argillaceous and siliceous slate as No. 9, giving the localities at which they occur. Two years later this classification was reviewed3 and the " Granular Quartz " dropped out of the nomenclature, 

only to reappear again with a very accurate description of the formation as it occurs in Vermont.4 It is interesting to note in this publication, that the " Granular Limerock" is mentioned as accompanying the 

" Transition Granular Quartz " from Whitehall on Lake Champlain, to 

Barnegat on the Hudson. Up to this time Prof. Eaton appears to have 

regarded the terms " Granular Quartz " and the " Granular Limerock " 

as interchangeable. In the classification of 1S24. 5 however, the "Granular Quartz " is separated from the " Granular Limerock " and fully 

described. The " Transition Argillite " and the " Primitive Argillite" 

are also defined, and some of the localities given are now known as 

localities of Lower Cambrian slates. The geologic profile accompanying the memoir of 1824 exhibits the differentiation made by Prof. Eaton 

in the classification of the rocks between the primitive granite and the 

secondary.

In the geologic nomenclature of to-day the "Granular Quartz" is 

included in the Lower Cambrian, and the " Granular Limerock" equals 

the Trenton-Chazy-Calciferous limestone. The " Primitive Argillites" 

of Williamstown Mountain equal the Upper Hudson or Lorraine 

shales. The "Transition Argillite" is nearly all Cambrian, with the 

exception of a small portion near the Hudson Eiver. The Calciferous 

sandrock is of the same age as the " Transition Argillite." The Graywacke of Peterborough Mountain, and the Metalliferous limerock is 

of Silurian (Ordovician) age. The "Transition Argillite" is mostly 

of Lower Cambrian age, and much of the so-called Calciferous sandrock and Graywacke of the section, represented as resting on the upturned edges of the "Argillite," are portions of the same series to which 

the "Argillite" belongs. Near the Hudson Biver a profound fault

 In a review of Maclure's memoir by C. S. Bafinesque it is suggested by him that " We must especially collect and describe all the organic remains of our soil, if we ever want to speculate with the 

smallest degree of probability on the formation, respective age, and history [of our strata." (Observations on the geology of the United States of America, by William Maclure; a notice. Am. 

Monthly Magazine, vol. 3,1818, pp. 41-44.)

2 An Index to the Geology of the Northern States, with a transverse section from Catskill Mountain 

to the Atlantic. Leicester, 1818.

8 Eaton, Amos. An Index to the Geology of the Northern States, 2d ed., 1820, pp. 154-212.

* Eaton, Arnos. A geological and agricultural survey of Kenaselaer County, New York, with a geological profile from Onondaga to Massachusetts, p. 16, plate. Albany, 1822. Memoirs of the board of 

agriculture of the State of New York, 1823, vol. 2, p. 9.

6 A geological and agricultural survey of the district adjoining the Erie Canal, 1824, pp. 30,56-58, 

plate. Albany.
WALCOTT.l GRANULAR QUARTZ.

with a great horizontal thrust has forced the Lower Cambrian over and 

on to the Silurian (Ordovician) rocks. The misunderstanding of the 

true relations of these rocks and a dependence upon their lithological 

characters led Prof. Eaton into an error that has come down to the 

present day in memoirs relating to the "Taconic System."

Prof. Eaton reviewed his work from time to time until 1832, when his 

final scheme of classification appeared. It is reprinted in the following 

tabulation, with the equivalents of his formations as known in the nomenclature of to-day. 1

t, p

f* r!

h-I B s

i o I

°

H M I

o

I L l

K I

I 

® f

*

- i tc f "i

H * 

Baton's Nomenclature (1832).

2. Millstone grit and rabble 1 C 

1. Second Gray wacke slate. { Secoml 0 yw«wke - 1

[Millstone gritand gray rubble ) First Gray- I

("Roof slate 1 (

1 Clay slate j (.

1. Granite, Mica slate.Hornblende and Talcose rock

1891.

Onoida, Clinton, Medina* 

TJtica, Hudson.

Lower and Middle Cambrian and Silurian.

Hudson. 

Considerable Hudson, but includes a

Kenssolaor County, K. Y. 

Trenton-Chazy limestone, Calciferons.

Cambrian livnostono.

Algonkian, pro-Cambrian, and Arohean.

The strati graphic position of the " GranularQuartz " (2 of the Primitive) 

is correctly represented, and it is now known to contain Olenellus sp.? 

A large portion of the strata referred to the " Argillite" (l,of the Transition) is also known to carry Olenellus asaphoides and to belong to the 

Lower Cambrian terrane. In the text the " Graywacke slate " (2, of the 

Transition) is described as resting uDconformably upon the upturned 

edges of the "Argillite" (1), and it is so represented in the section. This 

is essentially the same as the section of 1820 and as in the more detailed 

section of 1824.

Rev. Chester Dewey studied the geology of the vicinity of Williamstown, Massachusetts, and in 1819 2 published a short sketch of the 

mineralogy and geology of this region. He followed this in 1820 by a 

geologic section from the Tacouic range in Williainstown to the city of

1 Geological Text-book for aiding the study of North American Geology; being a systematic arrangement of facts collected by tho aiithor and his pupils under the patronage of the Hon. Stephen Van 

llensselaor. Second edition, 5 plates. Albany, 1832.

2 Sketcli of the Mineralogy and Geology of the. vicinity of Williams' College, Williatnatovm, Massachusetts. (With a map.) Am. Jour. Soi., vol. 1,1819, pp. 337-346.
94 THE CAMBRIAN. [BULL. 81.

Troy, on the Hudson.1 In this section the relations of the quartz formation to the mica slates of the Archeau are shown, and in a general way 

the Lower Cambrian slate is described. This is referred to the Transition argillite. In 1S242 he described the formation more in detail. On 

the map accompanying this paper the distribution of the various rock 

masses is more accurately given than in any maps published prior to 

those of Prof. James D. Dana, when studying the strata referred to the 

Taconic system. It exhibits an acquaintance with the surface distribution of the rock masses and a clear comprehension of the classification 

and correlation of rocks on the principle of lithologic characters. The 

distribution of the Granular Quartz and its relation.to the subjacent 

primitive rocks, or the mica slate of the map, is particularly well worked 

out. *

Dr. E. Emmons, a pupil of Prof. Eaton, adopted the order of succession of the strata as proposed by Eaton, and separated the " Granular 

Quartz" (2), "Granular Limerock" (3), and "Argillite" (1) to form a 

distinct series of rocks between the " Granite" (1) and the " Graywacke" (2) of the Transition. To this series of rocks he gave the name 

" Taconic," as Nos. 3 and 1 are largely developed in the Tacouic range of 

mountains. His central idea was that the rocks were nou-fossiliferous 

and beneath the zone of animal life, and were separated by their miueralogical characters from the subjacent and superjacent rocks.3

In accordance with the belief that the " Granular Quartz " belonged 

to a system of rocks which were beneath the zone of animal life, Dr. 

Emmons considered it the oldest of the sedimentary rocks, and far 

beneath the Potsdam sandstone surrounding the Adirondack mountains. He thus differentiated the Potsdam sandstone and the "Granular Quartz" as two distinct formations. The work of Messrs. Dewey 

and Emnions added little to the knowledge of the true position of the 

" Granular Quartz" in the geologic series, as they did not discover 

fossils in it or the associated formations.

Prof. H. D. Eogers, in summing up the results of his study of the 

marbles and sandstones of the western portion of Berkshire County, 

Massachusetts, states that he considered the Berkshire limestone and 

marble to be the equivalent of the (Trenton) limestone series of the New 

York section ; and that the semi-vitrified quartz was equivalent to the 

sandstone at the base of the same series (the Potsdam sandstone).4 In 

the same year, 1841, a discussion of these formations was published in

1 Geological section from Taconick range, in Williamstown, to the city of Troy, ou the Hudson. Am. 

Jour. Sci., vol. 2,1820, pp. 246-248.

2 A sketch of the geology and mineralogy of the western part of Massachusetts, and a small part of 

the adjoining States. Am. Jour. Sci., vol. 8,1824, pp. 1-60.

3 Geology of New York, Part 2, comprising the survey of the second geological (Northern) district, 

1842, pages 135-164.

4 Some observations on the geological structure of Berkshire, Massachusetts, and neighboring parts 

of New Tork. Am. Phil. Soc. Proc., vol. 2, 1841, pp. 3,4. On the physical structure of the Appalachian Chain, as exemplifying the laws which have regulated the elevation of groat mountain chains 

generally. Traus. Ajn. Assoc. Geol. Nat., 1842, p. 482.
WALCOTT.I GRANULAR QUARTZ. 95

the Geology of Massachusetts,1 in which the quartzite is described with 

many details. In the table on page 303, the " Granular Quartz " is 

placed at the base of the Paleozoic, or Sedimentary series, that is, at 

the base of the stratified rocks.

Dr. W. W. Mather,2 in his survey of this region, concluded with Prof. 

Kogers that the " Granular Quartz" and other rocks referred to the 

Tacouic by Einmons were the same as those of the Charn plain division 

of the New York section, modified by metauiorphic agency and the intrusion of Plutonic rocks. This correlates the " Granular Quartz" with 

the Potsdam sandstone. The " Granular Quartz" and the Potsdam 

sandstone were referred to the Primal series by Prof. H. D. Bogers 3 

along with all the quartzites that were found at the supposed base of 

the Paleozoic series in the Appalachian region and north through New 

York and Vermont into Canada, and westward into the Mississippi 

Valley. This reference to the Primal series is more fully described in 

the final report of the Geological Survey of Pennsylvania.4

Prof. Ebenezer Emmons described the " Granular Quartz" with considerable detail as the basal member of .his Tacouic system.5 In the reports of 1S44 and 184=7 its occurrence in western Massachusetts and western Vermont is noticed, and it is stated that in all probability it occurs 

as far north as the Canadian border. Its extension into Vermont had 

been previously noted by Messrs. Eaton and Dewey, and we find in the 

first annual report of the Vermont survey the statement by Prof. C. B. 

Adams6 that a quartz rock constitutes the western base of the Green 

Mountains from the north part of Addison County to Massachusetts; 

and it is further said7 that the quartz rock accompanies the Stockbridge 

limestone, disappearing with it in the north part of Addison County, 

and that near Lake Dunmore a bowlder was found in the vicinity of the 

quartzite beds containing two remarkable species of Polyparia(?). Two 

years later, in speaking of an excursion into Beuningtou County Prof. 

Adams says that the Quartz rock may equal the Potsdam sandstone, 

but there has evidently been too great a disturbance in this region to 

admit of certain conclusions.8

A full description of this formation is presented under the heading of

1 Final report on the geology of Massachusets, vol. 2,1841, pp. 560-593.

2 Mather, William. Natural History of New York. Ft. 1, Geology of New York; geology of the 

first (southeastern) district. Albany, 1843, p. 438.

3 0u American Geology and present condition of geological research iu the United States. Am. 

Jour. Sci., vol. 47,1844, pp. 151-154.

4 The geology of Pennsylvania. Philadelphia, 1858, vol. 2, p. 751.

'Geology of Now York, pt. 2, comprising the survey of the second geological (northern) district. 

1842, pp. 135-164. The Taconic System; based on observations in Now York, Massachusetts, Vermont, 

and Rhode Island, pp. i-vii, 67,6 plates, Albany, 1844. Agriculture of Now York, vol. 1, pp. 45-112, 

plates 21, map. Albany (1846), 1847. American Geology, containing a full statement of the principles 

of the science, with full illustrations of the characteristic American fossils. 8vo. Albany, 1856, vol. 

1, ;;t. 2, pp. 122.

c First Annual Report on the Geology of Vermont. Burlington, 1845, p. 57.

'Op. cit.,p. 61.

"Third Annual Koport on the Geology of the State of Vermont. Burlington, 1847, p 13,
96 THE CAMBRIAN.

" Quartz Eock " in the final report of the Geological Survey of Vermont 

by Prof. C. H. Hitchcock.1 Detailed descriptions are given of its character as found in Vermont, where it is said to have a thickness of at least 

1,000 feet.2 On this same page we read that " much of the quartz rock 

in the valley between Bristol and Starksboro can not be distinguished 

from members of the red sandrock series." Several species of fossils 

are mentioned as occurring in it; they are: A species of Lingula, a mollusk, resembling the Modiolopsis, a straight chambered shell (H), a few 

crinoidal columns, the Scolithus linearis (Hall), a few fucoids, and some 

indeterminable forms which are evidently organic.3 The exact geological horizon of the quartz rock is not determined.

At this point the review of the literature referring to the " Granular 

Quartz " will be postponed until it is taken up in connection with the 

" Ked Sandrock" and « Georgia Slates " of Vermont. In 1861 the three 

formations were practically united in one geologic terrane by the discoveries of Messrs. Billings and Barrande and the correlations of the 

Geological Survey of Vermont. A review of the references made to 

the Ked Sandrock and the Georgia Slates will next be given, and 

then the three formations will be considered together as they are described in .New York and Vermont.

BED SANDROCK.

When describing the formation terminating the Champlain group of 

the New York section Dr. E. Emmona correlated the brown or redbrown sandstone of Vermont, on the eastern border of Lake Champlain, as found at Addison, Charlotte, Burlington, and Colchester, with 

the gray sandstones that terminate the Lorraine shales of Jefferson 

County, New York. 4 He thus assigned the "Ked Sandrock" of the 

future to the summit of the Lower Silurian.

In presenting the results of his study of a section crossing Vermont 

from the Green Mountains to Lake Champlain, Prof. C. T. Jackson 4 

mentions the occurrence at Burlington Falls of a red sandstone containing numerous beds of buff-colored and blue compact limestone destitute of fossils. He referred it to the Potsdam sandstone of Dr. Emmous. " At Willard's quarry the red sandstone rock alternates with a 

bright red slate, covered with ripple marks made by the waters, from 

which the sediment was originally deposited." He further states that 

a mile from Burlington, on the Winooski River, large beds of compact 

blue and excellent white limestone are found.

Prof. C. B. Adams describes in the first report of the Geological

1 Hypozoic and Paleozoic rooks. Keport on the Geology of Vermont, descriptive, theoretical, economcal, and scenographical, vol. 1,1861, pp. 342-357.

*0p.cit.,p.355.

 Op. cit., p. 350.

4 Geology of New York, pt. 2, comprising thej snrvey of the second geological (northern) district. 

1842, pp. 123,124.

e Final Keport on the Geology and Mineralogy of the State of New Hampshire, with contributions 

towards the improvement of agriculture and metallurgy. Concord, 184.4, p. 16L
WAi.coTT.1 RED SANDROCK. 97

Survey of Vermont the occurrence of roofing slates in southern Vermont ' which he refers to the Taconic slate of Dr. Emuions, without a 

further attempt to assign them to a geologic horizon.

In the following year a section is given of Snake Mountain by Prof. 

Adams'4 in which the Eed sandrock is shown resting conformably upon 

the Hudson Eiver shale. In 1847 he referred to his studies of the Red 

sandrock3 and noticed the discovery of fragments of trilobites which 

Prof. James Hall identified as Conocephalus.4 He next assigned his 

Eed Sandrock to the Upper Silurian, correlating it with the Medina 

sandstone.5 Dr. E. Emmons criticised this view of Adams, and stated 

that he was in error. He regarded the formation as of Calciferous or of 

Potsdam age as proved by the fossils, stating that the rocks rest on the 

Taconic slate.6 Prof. Adams reasserted his view in 1848,7 stating that uo 

Hue of fracture occurred above the Treutou limestone,aiid that the Snake 

Mountain section showed that it contained Utica and Hudson Eiver 

rocks. Later, Dr. Zadock Thompson adopted the view that the Eed 

sandrock was in its natural position on the summit of Snake Mountain.8 

The view that the Eed saudrock series was the equivalent or the Medina of tbe New York section was sustained by Prof. W. B. Eogers9 

and the Medina or Clinton age of the " Eed sandrock " was supported 

by the Geological Survey of Vermont.10

Mr. E. Billings, on learning of the discovery of fossils in the " Eed 

sandrock " near Swanton, Vermont, by Dr. G. M. Hall and Eev. J. D. 

Perry, visited the locality and found a small Theca and a Conocephalites. Upon this paleoutological evidence he referred the strata to about 

the horizon of the Potsdam sandstone, to which position it has since 

been assigned by most authors who have had occasion to mention it.11 

Mr. Billings also corrected the statement of Prof. Hall, that the trilobites of the Georgia slate were from the Hudson terrane, and referred 

them to the Primordial or Lower Potsdam. This transferred the Georgia series and the associated " Eed sandrock " to the Cambrian.12

I have thus far referred only to the " Eed sandrock," as it was mentioned more definitely, and assigned to a geological position prior to 

the argillaceous and arenaceous shales and slates that overlie it. As 

the "Eed sandrock" and these shales or slates will be spoken of together

1 First Annual Report on the Geology of Veynont. Burlington, 1845, p. 35.

2 Second Annual Report on the Geology of the State of Vermont. Burlington, 1840, p. 163. 

8 Third Annual Koport on the Geology of the State of Vermont. Burliugion, 1847, pp. 13-15. 

4 Letter on certain fossils in the Ked sandrock of Highgate. Third Annual Keport on the Geology of 

the State of Vermont. Burlington, 1847, p. 31.

B On the Tacouic System. Am. Jour. Agrio. and Sci., vol. 6,1847, p. 260. 

6 (On the Taconic System.) Am. Jour. Agric. and Sci., vol. 6, 1847, p. 260. 

'On the Taconic Rocks. Am. Jour. Sci., 2d ser., vol. 5, 1843, pp. 108-110.

8 Geology of Vermont. Nat. Hist, of Vermont, Burlington, 1853, Appendix, p. 45.

9 (Notes on the geological structure of western Vermont.) Keport on the Geology of Vermont, vol. 

1, 1861, pp. 326, 327.

10 Hitchcock, C. H. Report on the geology of Vermont. Notes on the sections, vol. 2,1861, p. 650.

11 On the age of the red sandstone formation of Vermont. Am. Jour. Sci., 2d ser., vol. 32,1801, p. 232.

12 On Prof. J. Hall's claim to priority in the determination of the age of the rod saudrock series of 

Vermont. Am. Jour. Sci., 2d ser., vol. 33,1862, pp. 370-376.

Bull. 81 7
98 THE CAMBKIAN. [BULL. 81.

*

hereafter, I will now go back and give a short re"sum<§ of the history of 

the latter as mentioned by various authors.

GEORGIA SLATES.

The first notice we find of the slates and shales now referred to the 

Georgia terrane of Vermont is by Prof. Anios Eaton, iu 1818. The 

argillaceous and siliceous slates and, in isolated masses, a graywacke 

slate (Nos. 9 and 10 of his figured section) are shown to the east and west 

of the Hudson Kiver, the slates on the east alone belonging to the Cambrian.1 These slates were referred to the transition class.2 In the next 

edition of his index 3 these beds are referred to the Argillite (7) and the 

Graywacke (9), these terms being then applied to them as seen in Bensselaer County, New York, and in all of Baton's subsequent publications. 

It is the Argillite (1) and the First Graywacke or the Graywacke slate 

of the First Graywacke of the nomenclature of 1832 4 and his paper of 

1839.5 On liev. Chester Dewey's Geological Map of 1824 6 the-same 

areaiu Ronsselaer County is included under the term "Grey Wacke" 

and in part "Transition Argillite."

In defining the limits of the Taconic System in 1844,7 the northward 

extension of Prof. Eatou's Argillite aud Graywacke of Eensselaer 

County into Washington County was called the Taconic slates, and it 

was iu this series, a mile north of Bald Mountain, that the first fossils 

of the Ulenellus or Lower Cambrian zone were found by Dr. Asa Fitch. 

These slates, with their interbedded arenaceous layers, formed the Upper 

Taconic of Eminons, which he stated could be traced northward to the 

Canadian border. In the map accompanying Dr. Emmons's memoir on 

the Taconic System, published in 1844, all of the strata east of the 

Hudson are colored Taconic slates, or included in the Taconic system. 

The same strata in the map of 1842, published by the Geological Survey of New York, are included under the Hudson Kiver group.

Dr. Asa Fitch, a practicing physician in Washington County, Kew 

York, studied the local geology, and, under the headings of " Tacouic

'The Greywaeke or Grit area of the eastern part of Kensselaer County is now known to he ahove 

the metalliferous limestone of Eaton or the Trenton limestone series of the Now York State Survey. 

The recent work of Mr. T. Nelaon Dale, of the TJ. S. Geological Survey, establishes this and proves 

that I "was incorrect in referring this area to the Cambrian oil the map accompanying the paper on 

the Tacouic System of Emnions aud the use of the name Taconic in geologic nomenclature. (Am. 

Jour. Sci., 3d ser., vol. 35, 1888, pi. 3.) It is probable that the eastern portion of the Cambrian area, 

as thure mapped, to the north of the Berlin Grit area, iu western JBenningtou and Rutland counties, 

Vermont, may also prove to bo of Lower Silurian (Ordovician) age. (C. D. W., June, 1891.)

2 An iudox to the geology of the Northern States, "with a transverse section from Catskill Mountain to the Atlantic. Leicester, 1818, pp. 27-30.

3Au index to the geology of the Northern States. 2d ed., 12rno, Troy, N. Y., 1820, p. 163.

4 Geological Text Book, 2d ed., 1832. 

* Cherty lime-rock or Corniferons lima-rock proposed as the line ot reference for State geologists of 

New York aud Pennsylvania. Am. Jour. Sci., vol. 36,1839, pp. 69,70.

6 A sketch of the geology and mineralogy of the western part of Massachusetts and a small part of 

the adjoining States. Am. Jour. Sci., vol. 8,1824, pp. 1-60.

7 Emmons, E. The Taconic System; based on observations in New York, Massachusetts, Vermont 

and lihode Island. Albany, 1844, pp. i-vii, 67,6 plates.
WALCOTT.] GEOKGIA SLATES. 99

»

slate" and "Tacoiiic sandstone," 1 gives a description of the slates arid 

interbedded sandstone with considerable detail. He thinks that they 

may belong to an older system than the New York rocks, but no evidence is given to support this view. On page 865, Dr. Fitch states that 

in the summer of 1844 he found at Eeynold's Inn the first fossils known 

from the Taconic slate, and sent them to Dr. Emnions, who named and 

published illustrations of two species. Dr. Fitch also describes an 

annelid trail, Helminthoidichnites tennis, from the " Taconic slate" of 

Grauville.2

Dr. 0. B. Adams, of the Geological Survey of Vermont, called the 

northward extension of the Upper Taconic slate (of Emmons) of Washington and Beiisselaer Counties, the roofing slates of the Taconic system, 

and included them in his Hudson Eiver group.3

The fossils described from a locality of this horizon, near Troy, New 

York, in the paleontology of New York,4 were included by Prof. James 

Hall with those of the Hudson Biver group and were considered to be 

of that age. This same view was taken by him of the northward extension of this series in Yermont, when he described the trilobites from 

the shales of Georgia in 1859. At the close of this article he says: 5

In addition to the evidence heretofore possessed regarding the position of the shales 

containing the trilobites, I have the testimony of Sir W^ E. Logan that the shales 

of this locality are in the upper part of the Hudson River group, or forming a part 

of the series of strata which he is inclined to rank as a distinct group above the Hudsou River proper. It would be quite superfluous for me to add one word in support 

of the opinion of the most able stratigraphical geologist of the American continent.

Prof. 0. H. Hitchcock,6 in speaking of thetrilobite rock of Vermont, 

from which Prof. Hall's specimens were obtained, stated that he considered them as overlying the equivalent of the Oneida, which was 

superjacent to the Hudson Biver Bocks.

The attention of M. Joachim Barrande having been called to the 

fossils found in the Georgia slate, he studied them with great care, and 

published an extended review of the literature referring to them, and 

discussed the paleoutologic proof of the age of the rocks.7 He decided 

that the fauna was equivalent to his Primordial fauna of central Bohemia, and that it could not be referred to the Second fauna, as had been 

done by the American observers. Under the impression that Dr. Em1 A Historical, Topographical, nml Agricultural Survey of the County of Washington. Traus. N. Y. 

State Agric. Soc. for 1840,1850, pp. 830-857. 

2 0p.cit.,p.868.

3 First Annual Report on the Geology of the State of Vermont, Burlington, 1845, p. 01. On the 

Taconic Rocks, Am. Jouf. Sci., 2cl series, vol. 5, 1848, pp. 108-110.

4 Paleontology of New York, vol. 1, containing descriptions of the organic remains of the lower division of the New York system, 1847, pp. 252, 256,257.

r> Remarks upon the trilobites of the shales of the Hudson River group. Paleontology of New 

York, vol. 3, supplement to vol. 1,1859, p. 529.

8 On 'the geology of Vermont, chiefly in connection with the Taconic System. Boston Soo. Nat. Hist. 

Proc., vol. 7,1861, pp. 426,427.

'Documents anciens ot nouveaux sur la fauno priinordiale et le systoine tacouique on Am6rique. 

Soc. g6ol. France, Bull., 2" sor., vgl. 18,1861, pp. 203-321.
100 THE CAMBRIAN. [BULL. 81.

mons's stratigraphic work was correct, M. Barrande credited him with 

having correctly located the Primordial fauna in America.

In 1861 Prof. Hall changed the reference of the Georgia trilobites 

from the Hudson Eiver group to the Quebec group.1 In a letter written to M. J. Barrande, dated April, 1862, the explanation of this is given. 

He states that his own conviction was that the Red sandrock and 

the Granular Quartz of Vermont were of the age of the Potsdam sandstone and that the schists and shales which held the trilobites belong 

between the Potsdam sandstone and the Trenton limestone. He thus 

changed his views in relation to the age of the rocks containing Olenellus and other trilobites, and referred them to the lower portion of 

what is now designated as the Silurian (Ordovician). He says :

You will understand, then, that if rny views touching the relations of these rocks 

are exact the valley of the Hudson Eiver from the high lauds on the south of Lake 

Champlain, save a small number of inconsiderable exceptions, is occupied by rocks 

of the Primordial zone, that is, by rocks placed between the Potsdam sandstone and 

the Trenton group. Thus the Hudson Kiver group in its typical localities belongs to 

the Primordial period.2

In explaining how he came to adopt the view that the trilobites from 

the Georgia slates of Vermont and those described by Dr. Emmons 

from the black slates of Washington County belonged to the Hudson 

Eiver group, together with the strata in which they were contained, he 

says:

I wish to claim nothing for myself or for my former views, for we owe the final 

solution of this question to the Canadian survey. Yet there remain some divergent 

views in regard to the relation between the shales and the Potsdam sandstone.

He further states that this arose from his seeing the Potsdam sandstone run beneath the slate at Whitehall. New York, and a number of 

other places; that at no point where the Potsdam sandstone is seen is 

there any shale or other formation beneath it, excepting the crystalline 

rocks of the Adirondacks. Speaking of the " Granular Quartz," he says 

that it presents the same relation as the Potsdam sandstone to the 

schistose rocks; that he has always referred it without hesitation to the 

Potsdam sandstone. He held the view that the schistose rocks, with 

their impure sandstones, brecciated limestones, and calciferous sandrock, are to be placed between the Potsdam sandstone and the Trenton" 

limestone group; that the relation of this group of schists or slates to 

the Potsdam sandstone seems to be that of an upper formation. In 

none of the outcrops that he saw in the disturbed region east of the 

Hudson was there one that could explain the phenomena presented, on 

the supposition that the sandstone is the upper rock. He then quotes 

the nomenclature of Eaton to show that it was almost the same as that 

finally adopted by the Geological Survey of New York, that is, the order 

of superposition of theo formations, the ''Granular Quartz'7 being placed 

at the base. It is also stated that the graptolites found in the beds

1 Correction for the thirteenth annual report. 14th Ann. Rep., State Cab. Nat. Hist., 1861, p. 110. 

a Letter on the Primordial of America. Soc. geol. France, Bull., 2" aer., vol. 19, 1862, p. 732.
WALCOTT.] GEORGIA TEERANE. 101

formerly referred to the Hudson Biver are considered to belong to the 

Primordial fauna. l

The geologists of the Vermont survey in their final report included 

the shales aud associated slates and arenaceous beds under the title of 

Georgia group. In proposing the name Georgia group to designate 

these rocks, Prof. 0. H. Hitchcock said : 2

Wo use the terra Georgia group to designate this terrain, from the town of Georgia 

in Franklin County, where it is developed in its full proportions and where the mosfc 

interesting fossils have .been found. It is a name also which does not involve any 

theory, and may be used by both parties iu the controversy respecting its age. * * * 

The Georgia slate includes what Prof. Emrnons has ranked as the black slate, Taconic slate, aud roofing slate; and yet not altogether, for we have regarded all tho 

black slate beneath the rod sandrock as belonging to the Hudson River group. The 

characteristic trilobites of the Georgia slate are represented by Eminons in his Tacouic System, 1844, as found in the black slate.

The following fossils are cited as characterizing the Georgia slate in 

Vermont: Barrandia thompsoni Hall, B. vermontana Hall, Batliynotus 

holopyga Hall, Graptolitlius milesi Hall, the trail of an annelid, and 

unknown species of fucoides. 3

The strati graphic position of the Georgia series was considered to be 

above the sandstone which represented the Oneida conglomerate, and 

the thickness of the slate was thought to be at least 3,000 feet.4 A 

discussion of the stratigraphic position of the faunas found in the 

Georgia slates by Prof. James Hall, Sir William E. Logan, and M. J. 

P>arrande, accompanies the chapter. A fair presentation of the argument for and against the Silurian age of the terrane is given. In a 

note upon the trilobites of the shales of the Hudson Eiver group, in 

the same volume, Prof. Hall redescribes the fossils mentioned in his 

paper of 1859. In the second volume of the Geology of Vermont, on 

page 799, the " sparry limestones'7 occurring as thin bands in the roofing slate series in Fairhaven, Vermont, are correlated with the red sandrock or Wiuooski marble of the northern portion of the State.

In describing the rocks of Waterville, Maine, Prof. C. H. Hitchcock5 

states that the slates are similar in mineralogical structure to the 

Georgia slates of Vermont, which are equivalent to the Potsdam sandstone.

With the determination (a) by Mr. E. Billings that the " Red sandrock" was of primordial age;6 (6) by Mons. Barrande that the fossils 

from the Georgia slate belonged to the Primordial fauna; (c) that the 

"Granular Quartz" was the basal member of the Paleozoic, and had 

been correlated with the Potsdam sandstone, which, from its included

1 Op. cit., p. 732.

2 Hypozoic and Paleozoic rocks. Eeport OD the geology of Vermont, vol. 1,1861, p. 358. 

8 Op. cit., p. 367. 4 Op. cit., p. 366.

8 General report on the geology of Maine. Preliminary Eep. on the Nat. Hist, and Geology of Maine. 

Angnsfa,1861,p. 233. 

6 On the ago of tho rod sandstone formation of Vermont. Am. Jour. Soi., 2d aer., vol. 32,1861, p. 232.
102 THE CAMBRIAN. [BULL. 81.

fossils in the Mississippi Valley, was also referred to the Primordial, 

the review of the history of these three Cambrian formations as they 

appear in New York and Vermont is carried forward as that of one terrane.

In speaking of the determination of the age of the slates in Georgia, 

Vermont, Mr. E. Billings states that Mons. Barrande first determined 

their age.1 He further says:

At the time I wrote the note on the High gate trilohites it was not known that 

these slates were conformably interstratified with the Red sandrock. This discovery 

was made afterwards by the Rev. J. B. Perry and Dr. G. M. Hall, of Swanton.

He also mentions the discovery on the Straits of Belle Isle, by Mr. J. 

Richardson, of the Canadian Geological Survey, of Scolitkus linearis, 

Paradoxides thompsoni, and P. vermontana, and a number of other species of which a list would be given further on. He adds:

The sandstones and limestones of the north shore of the straits [of Belle Isle] appear to be of the age of the Potsdam of Pennsylvania and Tennessee. The form of 

the Scolithus is identical with that which occurs in these two States, and some portions of the rock is a coarse red sandstone, exactly like the specimens sent to rue 

about a year ago from Tennessee by Prof. Safford.

Mention is made of the discovery by Rev. J. B. Perry and Dr. G. M. 

Hall of a group of fossils interstratified with the Red sandrock east of 

Swanton, Vermont. Of the species found, four occur in the limestone 

which overlies the sandstone with Scolithus linearis on the north shore 

of the Straits of Belle Isle.

Taking all these facts together scarcely anything more is necessary to show that 

the Red sandrock of Vermont is of the age assigned to it by me from an examination 

of Conocephalifces at Highgate in July last. * * * Barrande's opinion, founded 

altogether upon the aspect of these trilobites is thus completely verified.2

At the close of the paper is a list of the fossils found in Vermont and 

on the Straits of Belle Isle, all of which are referred to the Potsdam 

group.3 In speaking of the claim of Mr. Billings, that he bad identified the Primordial fauna in the Red sandrock and determined its geological age, Prof. James Hall 4 states that he had published sections and 

made statements in relation to the age of these rocks to show that he 

considered them to be of the age of the Potsdam sandstone of the New 

York section. In reply Mr. Billings 5 said that the sections spoken of 

by Prof. Hall do not cross at any point the Red sandrock or Georgia 

slates, where they are recognized by Prof. Hall as belonging to the 

Potsdam. On the contrary, they are marked on the section as belonging to the Trenton-Hudson series.

1 Further observations on the age of the red sandrock formation (Potsdam group) of Canada and 

Vermont. Am. Jour. Sci., 2d ser., vol. 33, 1862, pp. 100-105. (See note and corrections, same vol., pp. 

421-122.)

2 0p.cit.,p.l02. 3 Op. cit., p. 104.

4 On thoPotsdam sandstone and Hudson Kiver rocks in Vermont. Am. Jour.Sci.,2d ser., vol.33, 

1862, pp. 106-108.

*0n Prof. J. Hall's claim to priority in the determination of the age of the Ked sandrock series of 

Vermont. Ani. Jour. Sci., 2d ser., vol. 33,1862, pp. 370-376.
WAI.OOTT.] GEORGIA. TERRANE. 103

When tracing the formations that occur north of the Vermont and Canada boundary to the southward, Sir William E. Logan studied a section 

in the vicinity of Swanton, Vermont, in which the Georgia slates and the 

Oleriellus fauna occur above the Red sandrock.1 The latter are red and 

white dolomites in sandy layers. The measurement of this section gave 

a thickness of 710 feet, including 190 feet of shale, carrying the fossils 

which Mr. Billings described. He traced the rocks of the Swanton section north to the vicinity of Saxe's Mill, near the United States and Canadian border, where a measured section of the dolomitic sandstone gave 

a thickness of 1,410 feet.2 These sections cross the Eed sandrock formation of the older authors. The name Eed sandrock is a misnomer, as 

there is in reality comparatively little sand or arenaceous material, other 

than arenaceous limestone of a highly dolomitic character, in the entire 

section.

Prof. Jules Marcou took a very active interest in the discussion of 

the strati graphic position of the fauna found in the slates of Georgia, 

Vermont, and published numerous papers upon the subject from 1860 

to 1888. In a paper published in 1861 3 he records some of his own 

observations, saying that in Vermont the Potsdam sandstone has exactly the same aspect and composition as at Potsdam, in the .State of 

New York. Near Saxe's Mills, a mile east of Highgate Springs, it contains two species of Conocephalites, C. adamsi and C. vulcanux. He 

states that the formation is broken up into narrow bands that are 

numerous and well developed west of Mr. Parker's farm at Georgia, 

and also on the road between St. Albans and Swanton, Vermont; and 

that although at first they appear to be interstratified with the Georgia 

slates, they are not so, but may be compared with the steps of a ladder 

placed over, or even a little wedged into the Georgia slates and Lingula 

Hags. He says:

This group has been known for a long time in Vermont by the name ol'Red Sandrock. * * * Below the Potsdam sandstone lie great masses of slate, fom: or five 

thousand feet thick, which for convenience I should divide into three parts.'1

These are the Lingula flags, Georgia slates, and St. Albans group.

The Georgia slates are stated to be characterized by Primordial fossils, notably Paradoxides (Olenellus) thompsoni, P. vermontana, Peltura 

holopyga, Obolella cingulata, etc.5

In noting the discovery of fossils in the Winooski marble, at Swan ton > 

Vermont, Mr. E. Billings c states that fossils were discovered by Mr. 

Solon M. Allis, of Burlington, Vermont, who sent them to him for cx1 Geological Survey of Canada; report of progress from its commencement to 1803. Montreal, 1SG3, 

pp. 281,282.

-Op. cit., p. 282.

3 The Taconic and Lower Silurian roots of Vermont and Canada. Boston Soc. Nat. Hist. Proc., vol. 

8,1802, pp. 239-253.

 > Op. cit., p. 244. * Op. cit., p. 245.

" Note on the discovery of fossils in the " Winooski marble," at Swanton, Vermont. Am. Jour. Sci., 

3d ser., vol. 3,1872, pp. 145,146. Canadian Nat., new ser., vol. C, p. 351.
104 THE CAMBRIAN. [BULL.81.

araiiiation. He found a species of Salterella, which he identified as 

Salterella pulchella. He observes that the Winooski marble, both at 

Swanton and St. Albans, seems to underlie the Georgia slates, and he 

says:

It is generally of a reddish, mottled color, but sometimes gray or greenish. The 

limestone at the Straits of Belle Isle, in which S. pulchella is found, is also red, gray, 

and greenish; and is, I have no doubt, of the same age. At this-latter locality it 

overlies a red or brownish sandstone, conformably, which holds Scolithus linearis. I 

consider the Belle Isle sandstone to be the " Quartz rock" of the Green Mountains of 

Vermont. In that case, the limestone at Belle Isle occupies, stratigraphically, the 

position of the Stockbridge limestone as represented by Dr. Emmons in his American 

Geology, part 2, p. 19. f

Under the title " Geology of Vermont," Prof. C. H. Hitchcock tabulates the formations of that State.2 The Potsdam group is made to 

include the Eed Sandrock, part of the Hudson Eiver slate, part of the 

Georgia slate, most of the quartz rock, and the Potsdam sandstone of 

West Haven. Speaking of the latter he says, the Potsdam rocks flank 

the gneiss upon the west side as far north as Middlebury. He further 

observes that the quartz rock is probably the same as the red sandstone; 

that both are overlain by the Levis3 limestone, and resemble each other 

very much near their supposed union. " I find this view of the identity 

of those two formations confirmed by the late map of the Canadian survey, published in 1866."

In an article on some points in the Geology of Vermont, Dr. T. S. 

Hunt states :

It happens, then, from the facts already set forth, that the Potsdam formation, 

which at its outcrop at the foot of the Adirondacks and Laurentides includes only 

from 300 to 700 feet of sandstone, is represented a few miles to the eastward by not 

less than 2,000 feet of dolomites, sandstones, and slates, and moreover that occupying a position between the calciferous and chazy formations, which are contiguous 

at their eastern outcrop, there becomes intercalated within this short distance a fossiliferous group, several thousand feet in thickness. 4

The explanation of this is quoted from Logan's opinion, to the effect 

that the Potsdam sandstone accumulated along the shore, while shales 

and limestones were accumulating to a greater thickness in the deeper 

water of the adjacent ocean. In summing up the evidence as to the 

age of the rocks of western Vermont he says:

All the evidence, paleontological and stratigraphical, as yet brought forward 

affords no proof of the existence in Vermont of any strata (a small spur of Laurentian excepted) lower than the Potsdam formation, which the present advocates of 

the Taconic system regard as forming its summit. * * * That strata still older 

than the Potsdam of New York and Vermont were deposited in some portions of the 

oceanic area is apparent from the existence in New Brunswick of the St. John's 

slates holdiug a Primordial fauna older than the Potsdam, and it is not impossible

1 Op. cit., p. 351. 2 Am. Assoc. Proc., vol. 16, 1867, p. 120.

3 Levis group, including the " Eolian limestones," "Hudson Biver limestones," and the greater portion of the Georgia slate. (Op. cit., p. 120.) 

4 Ou some points in the geology of Vermont. Am. Jour. Sci., 2d ser., vol. 46,1868, p. 225.
WALCOTT.] GEORGIA TERRANE. 105

that their equivalents may underlie the Potsdam formation of Vermont. No such 

rocks, Lave, however, as yet been detected in either Vermont or Canada. i

That Dr. Hunt also confounded the typical Potsdam sandstone of 

the Adiroudacks, the quartzite of the western base of the Green Mountains, and the Primordial series described by Murray in Newfoundland 

is shown by his statement that a few hundred feet of typical Potsdam 

sandstone in New York are represented in Vermont, Quebec, and Newfoundland by thousands of feet of strata lithologically very unlike the 

type.2

In 1867 Prof. C. H. Hitchcock identified the Winooski marble of 

Vermont as the Bed Sandrock, and stated that Olenellus tliompsoni and 

0. vermontana occurred in the superjacent slaty layers.3 In the same 

volume he presents a table of the strata from the Silurian to the Devonian, inclusive, as found in Vermont, and in this connection he says 

he considers the Taconic to be of Lower Silurian age. This included, 

as described by Emmous, the Georgia slates.4

At the time of the presentation of the two foregoing papers by Prof. 

Hitchcock a paper on the Bed sandrock of Vermont and its relations 

was read by Mr. J. B. Perry.5 He concluded that the Bed sandrock 

was equivalent to the Potsdam, and that the sedimentary beds below 

the Potsdam were not Utica or Lorraine, but belong to the Primordial 

zone of Barraude. The Potsdam is considered to be the top of the 

Primordial, not the base of the Silurian. In the table of formations 

the Bed sandrock or Potsdam is placed at the top of the Taconic system, aud the Taconic slate with the quartzite limestone or conglomerate at the base. The following year the same author 6 again stated 

that the Bed sandrock was of Potsdam age and not Medina, and he 

subdivided the slates below into the Swanton and Georgia series, as 

older than the Utica slate, referring them to the Primordial of Barran de.

In a summary of the Geology of Vermont, by Prof. 0. H. Hitchcock,7 

published in connection with the Geology of Northern New England, 

it is stated, under the head of " Potsdam Group," that it includes (1) 

black slate, or part of the " Hudson Biver slate" of the former report 

of the Vermont Survey. (2) Georgia slate. (3) Bed Sandrock and 

quartz rock at the base of the Green Mountains. (4) Potsdam sandstone, the same as the original beds in New York.

1 Op. cit., p. 229.

2 On the geology of eastern "New England. Am. Jour. Sci., 2d sor., vol. 50, 1870, p. 85.

3 The Winooski marble of Colchester, Vermont. Am. Assoc. Proc., vol. 16,1807, p. 119.

4 The Geology of Vermont. Am. Assoc. Proc., vol. 16,1807, p. 122. 

fi Am. Assoc. Proo., vol. 16,1867, pp. 128-134.

"Queries on the red sandstone of Vermont and its relations. Boston Soc. Nat. Hist., Proc., vol. 

11,1868, pp. 341-353. 

7 The geology of Vermont. In Geology of northern Mew England, 4to, 1870, p. 2.
106 THE CAMBRIAN. [BULL. 81.

The Rod sand rock is described as extending from St. Armaud, province of (Quebec, to Bridport, Vermont.

The brightest red rocks are found along the western border; so that while the alliance of the red rock of Burlington and the quartzite of Bennington seems incongruous, it is otherwise with the reddish rocks of Moukton and the brown quartz, of 

Sfcarksboro' and Bristol. 1

It is stated that the name Georgia was applied to the group of slates 

carrying Olenellus. It was then supposed that the slates \vere entirely 

distinct from the sandstones, but farther investigation has shown an 

interstratification, with the presence of the characteristic trilobites 

throughout the beds.

Of the " Granular Quartz " on the western slope of the Green Mountains he says:

No rock can be more distinct from all others than the quartzite from the State 

line north to Starksboro', consisting chiefly of pure vitreous silica, sometimes hardly 

showing a sedimentary composition. * * * The group makes a mountain range 

throughout, some of the peaks exceeding 3,000 feet in height. * * * An abundance, of Scoltlhus linearis appears in this formation, and the rock was referred to the 

Potsdam in 1841 by II. D. Rogers and W. B. Rogers, in opposition to E. Emmons, who 

subsequently called it "granular quartz," lying at the base of the Taconic system, 

thousands of feet below the former. 1

In 1871 Mr. S. W. Ford2 published an account of a section of rocks at 

Troy, New York, in which he had found the Olenellus fauna. In 1884, 

he added3 a description of a section near Schodack Lauding, south of 

Troy, in Columbia County, New York. By the contained fauna the 

strata were correlated with those described by Sir William Logan, in 

Vermont, Canada, and Newfoundland.

Prof. J. D. Dana,4 from 1872 to 1877 worked out, with considerable 

detail, the strati graphic relations of the "Granular Quartz," of Berkshire County, Massachusetts, to the subjacent Archean and the superjacent Silurian limestone, adding many details to the general outlines 

published by Messrs. Eaton, Dewey, and Emmons. In the description 

of the quartzite, limestone, and associated rocks of Great Barrington, 

Berkshire County, Massachusetts,5 it is stated that the quartzite of Great 

Barrington alternates with mica schist, and that both of the rocks for 

the most part overlie the Stockbridge limestone. Of the Green Mountain quartzite, Prof.Dana says: 6 "In the first place there are quartzites 

of more than one age in New England, west of the Connecticut Ei ver." A

'Op. cit., p.3.

"Notes on the Primordial rocks in the vicinity of Troy, New York. Am. Jour. Sci., 3d ser., vol. 2, 

1871, pp. 32-34. Can., Nat., new ser., vol. 6,1872, pp. 209-212.

3 On the age of the glazed and contorted slaty rocks in the vicinity of Schodack Landing, Kensselaei 

Connty, New York.. Am. Jour. Sci, 3d ser., vol. 28,1884, pp. 206-208.

4 Green Mountain geology. On the quartzite. Am. Jour. Sci., 3d ser., vol. 3,1872, pp. 179-186, 250- 

250. An account of the discoveries in Vermont geology of the Kev. Augustus Wing. Am. Jour. 

Sci., 3d ser., vol. 13,1877, pp. 332-347, 405-419 ; vol. 14, pp. 36-37, 1877.

6 0n the quartz, limestone and associated rocks of the vicinity of Great Barrington, Berkshire 

County, Mass. Am. Jour. Sci., 3d ser., vol. 4, 1872, p. 362.

6 Green Mountain geology. On the qnartzite. Am. Jour.' Sci., 3d ser., vol. 3,1872. p. 181.
WALCOTT.] GEORGIA TERRANE. 107

Hblderberg quartzite exists at Bernardston, Massachusetts, and another 

quartzite of different age, about 3 miles west of Plymouth, Vermont, 

is iuterstratified with gneiss; and then there is the great quartzite of 

the Green Mountain range, whose relation to the quartzites interbedded 

in the gneiss is unascertained. " We can not assume, therefore, that 

this last is all of one geological age." After examining the quartzite of 

Canaan, Connecticut, he was led to the conclusion from the facts observed 

that the quartzite is the inferior rock, and rests unconformably beneath 

the limestone.1

When briefly presenting some conclusions concerning the strati graphical structure of the Cambrian of western Vermont, Prof. C. H. Hitchcod^ states that Dr. Emmons believed the rocks were deposited against 

the western base of the Green Mountains, in order of, first, the Granular Quartz, then the Stockbridge limestone, and lastly the various slates 

which were capped by the black slates holding Olenellus. The report 

says further:

Prof. Hitchcock suggested as a better theory of structure, thatsedi incuts were formed 

contemporaneously, both upon the Greon Mountains and the Adirondack aide of the 

valley, thus making tho granular quartz on the east side of the- v:illoy of tlw KJI.IIIO 

age with the Potsdam sandstone at Whitehall, N. Y., and elsewhere west of Lake 

Champlain. Next, the Calciferous sandstone, Lev is, Chazy. and Trenton limstones, 

were deposited entirely across the valley and by means of their fossils are now identified adjacent to both the quartz rock and the typical Potsdam sandstone. Thirdly, 

the limestones are succeeded by slates. This theory of original deposition differs from 

that of Emmons, in supposing that sedimentation was being effected both on tho 

Green Mountain and Adirondack borders, instead of on the former only. 3

In summing up the account of the discoveries of lie v. Augustus Wing 

in Vermont geology, Prof. Dana says : 4

The Red sandrock on the west of the Eolian limestone admitted to be Potsdam or 

Primordial in ago and the Quartzyte on tho east which often rises into mountain 

ridges, are of the same formation, and come nearly or quite together in Monk ton, on 

the northern limits of the limestone area (p. 414).

The quartzyte of the eastern range, with that also of the local belts in the Eolian 

limestone area, is regarded as Potsdam (or Primordial) in age, because it contains in 

many places Scolithi (worm-burrows) and Fucoids like those found in the Potsdam 

sandstone; because also it adjoins Calciferous limestone beds at the localities just 

mentioned in North Middlebury and Now Haven; and because it joins the Red sandrock in Moukton, and one rock has in many places the character of tho other, although 

not commonly alike in color, and showing differences explainable on the ground of 

the greater metamorphism of the quartzyte. " In Monktou, tho Red sandrock and 

the Quartzyte meet in a succession of short auticlinals, thus cutting oil' to the norllv 

the great trough or synclinal;" and "the Red sandrock absolutely overlies tho beds of 

Red sandrock in one anticlinal and the quartzyte in another anticlinal, and both hold 

ScoUtlms linearis." 5

'Op. cit., p. 185.

"Remarks 011 tho stratigraphical structure of tho Cambrian anil Cambro-Silnrian rocks of western 

Vermont. Boston Soc. Nat. Hist., Proc., vol. 18,1875, p. 191.

S 0p.cit.,p. 101.

* An account of the discoveries in Vermont geology of tho Rev. Augustus Wing. Am. Jour. Sci., 3d 

sor., vol. 13, 1877, p. 414-416; vol. 14, pp. 36-37.

6 Op. cit.p.416.
108 ' THE CAMBKIAN. fBULL.81.

Dr. T. S. Hunt, in 1878, 1 gives an historical review of the rocks referred to the Cambrian and Taconic systems and in this way speaks of 

the " Upper Taconic" and refers it to the Cambrian, and the "Granular Quartz " to an Archean system. Again, in 18S3,-'S4,-'86, he went 

over the same ground,2 but did not add any original information upon 

the subject. He adopted the view of Prof. Eaton so well expressed in 

the section of 3 824, and brought down to 1886 the erroneous view of the 

unconformity between the Calciferous sandrock and the Argillite. To 

the strata which Dr. Emmons included in the Taconic system, in 1842, 

he gave the name Taconian, referring them to a pre-Gambriao, Archean, 

group of rocks.

In a paper upon the colonies in the Taconic rocks of the borders of 

Lake Champlain,3 Prof. Jules Marcou gives a resume" of his investigations in northern Vermont up to date. In the vertical section accompanying the geological map, the Potsdam sandstone is placed at the 

summit of the upper Taconic series, and then in order below, the Swanton schists, Phillipsburg group, Georgia schists, and the St. Albaus 

group. On sections in the text the Potsdam sandstone is represented 

as unconfor in ably superjacent to the Georgia slates, the Phillipsburg 

group, and the Swanton schists, and the St. Albans group. A general 

description is gi^en of the formations as interpreted by Prof. Marcou. 

As now known the Potsdam sandstone as identified by him, is the Eed 

saudrock of the Vermont geologists, or the arenaceous inagnesian limestone of Logan. Its stratigraphical position is at the base of the series 

described, or at the base of the Lower Cambrian as now understood.

A series of geological sections across Vermont and New Hampshire 

by Prof. C. H. Hitchcock4 have the Eed Sandrock series marked as 

Potsdam and the Georgia slate series as Cambrian. The Granular 

Quartz of the southern portion of Vermont is all marked Potsdam. In 

the text5 Prof. Hitchcock says :

Three bands of sandstone therefore are referred to the Potsdam in the Champlain 

valley: first, the normal gray sedimentary beds at the foot of the Adirondacks, 

always known -under this name since 1840 ; second, the quartzite on the flank of the 

Green Mountains; third, a range of red sandstone and dolomite from the Canada 

line to Bridport, where it is succeeded by outcrops of a material not distinguishable from the first named band. Partly accompanying the middle band is a series of 

slates and hard sandstones, passing into roofing slates called the Georgia group in 

the State report, which carries such fossils as Olenellus and Angelina, and is, therefore, thought to be somewhat older than the typical Potsdam sandstone.

In the same publication Prof. E. P. Whitfield 6 states it to be his

1 Special report on the trap dikes and azoic rocks of southern Pennsylvania, 2d Geol. Surv. Pa., E., 

3878, p. 253.

2 Tho Taconic question in geology. Mineral Physiology and Physiography. A second series of 

chemical and geological essays, with a general introduction. 1886, pp. 517-686.

8 Sur les colonies dans les roches taconiques des bords du lac Champlain. Soc. g6ol. France, Bull., 

3 s6r, vol. 9, 1880, pp. 18-46.

«Geological sections across Vermont and New Hampshire. Am. Mus. Nat. Hist., Bull., vol. 1,1884, 

pp. 155-179.

60p.cit.,p.160.

6 Notice of some new'species of.Primordial fossils in the collections of the Museum, and corrections 

of previously described species. Ain. Mus. Nat. Hist.. Bull., vol. 1,1884, p. 140.
WALCOTI.] GEORGIA TERRANE. 109

impression that the New York typical Potsdam is about equivalent to 

the lower portion of the Wisconsin series; and that the Acadian beds 

of Canada and Vermont, and perhaps the other Atlantic areas, are not 

appreciably different in age; but the difference in faunae is more the 

result of conditions upon which life depended than a difference in time. 

This generalization of Prof. Whitfield placed the "Granular Quartz," 

".Red sandrock" or dolomite, Georgia slate and the Potsdam sandstone 

of New York and the Upper Mississippi Valley in one geologic horizon, 

the equivalent of the lower beds of the Mississippi Valley section.

In 1888 Prof. N. H. Winchell 1 correlated the "Granular Quartz" of 

Emmous's Taconic system with the Potsdam sandstone, and mentions 

its westward extension in the Mississippi Valley. In another paper 2 he 

says that the stratigraphical relations of the "Granular Quartz" and 

the Potsdam of New York are the same; that the fossils are cognate 

with those of <£he Ked Saudrock and with those that have been found 

in the Potsdam; that the Eed sandrock overlies the Georgia unconformably, and that the stratigraphic relations of the Granular Quartz 

and the Potsdam sandstone to the granite are the same as those of a 

Primordial quartzite of the northwest to the granite.3

In summing up the opinions of the geological position of the quartzite 

on the eastern border of the limestone, and between the limestone, and 

the Archean, Prof. J. D. Dana 4 says that he pointed out in 1872 that 

the quartzite formation in southeastern Dutchess County lay between the 

limestone and the adjoining Archean, and the same also occurs in other 

localities; that he inferred from the position and apparent conformability that its age was Potsdam or that of the lowest beds of the Lower 

Silurian of the region; also, that there is a quartzite west of the border of 

the limestone that overlies the limestone conformably, and is an independent formation and newer than the limestone. In his stratigraphic 

conclusions at a later date 5 the Cambrian quartzites are supposed to be 

those immediately adjacent to the Archean gneiss and equivalent to 

the Potsdam sandstone, while those that occurred at a horizon above 

the limestone are supposed to belong to the Hudson period.

In a paper on " The Tacouic System and its position in stratigraphic 

geology" Prof. Jules Marcou6 tabulates the strata referred to the Taconic 

system in eastern North America. In this, the Saratoga limestone, 

with Dikellocephalus is the summit of the series, above the Eed sandrock of Vermont and the Potsdam sandstone of Keeseville, New York.

1 A great Primordial Quartzite. Am. Geol., vol. 1,1888, pp. 173-178.

2 The crystalline rocks of Minnesota. General report of progress made in the study of thoir field 

relations. Statement of problems yet to be solved. Geol, and Nat. Hist., Survey of Miun., 17th Ann. 

Bep. for 1888,1889, pp. 5-74.

3 Op. cit., pp. 49,50.

4 On Taconic rocks and stratigraphy, with a geological map of the Taconic region. Am. Jour. 

Sci., 3d ser., vol. 29,1885, p. 209.

6 On Taconic rocks and stratigraphy, with a geological map of the Taconic-regions. Part 2. The 

middle and northern part. Am. Jour. Sci., 3d ser., vol. 33,1887, pp. 408-409.

6 Am. Acad., Proc., vol. 20, 1885, p. 224.
110 THE CAMBRIAN. [BULL. 81.

In order, below, comes the Swauton slates, and the Phillipsburgh or 

Point Levis group, subjacent to which are the Georgia slates (or Olenellus zone). The Paradoxides zone, the Upper Cambrian or Eophyton 

sandstone of Great Bell Island, Newfoundland, and the Aspidella and 

Arenicolites slates of St. John's, Newfoundland, are assembled under 

the name li St. Albans group."

In this table, under the upper formations or " Potsdam group," there 

are brought together the summit of the Cambrian (the Saratoga limestone) and the base of the ©ambrian (the Red sandrock of Vermont), 

as well as the Keeseville sandstone, which is the lower portion of the 

Upper Cambrian. In the ".Swanton slates " (Trenton-Hudson terrane) 

and in the u Phillipsburg or Point Levis group," we have the Calciferous-Chazy zone. The Eophyton sandstone placed beneath the Georgia 

slates and the Paradoxides beds is the equivalent of the Saratoga limestone placed at the summit of the series. The Aspidella and Arenicolites slates of St. John, Newfoundland, are of pre-Cambrian age. Thus 

the lower or " St. Albans group " includes pre-Cambrian, Upper Cambrian, and Paradoxides zone strata.

In an article on the Winooski or Wakefteld marble of Vermont, Prof. 

G. H. Perkins1 described several sections of the strata containing the 

quarries worked for marble, one of which has a thickness of 1,410 feet, 

another 790, and another 710 feet. He found Salterella pulcliella in the 

marble beds and considered the series to be of Primordial age.

When describing a section in the Cambrian formation of western 

Vermont in the town of Georgia, Franklin County, Mr. 0. D. Walcott 2 

stated that the section consisted of a massive belt of limestone 1,000 

feet in thickness subjacent to a series of argillaceous shales, at the base 

of which the Oleuellus fauna occurred. He also stated that this section 

includes in its vertical range the sections above and below Troy, N. Y., 

in the Hudson Ki ver Valley, and those of Newfoundland and the Straits 

of Belle Isle. This was followed in the same year 3 by a detailed description of the Georgia section, and another section taken near the 

Canadian and United States boundary in the township of Highgate. 

At this latter locality the Eed saudrock series has a thickness of 1,170 

feet; the Georgia slates a thickness of 1,000 feet. A list of the fossils 

occurring in the strata is given in the tabulated section. Following 

the nomenclature proposed by Sir William Logan, the lied sandrock 

series and the Georgia slates are referred to the Middle Cambrian subjacent to the Potsdam sandstone of the Adirondacks, and above the 

Paradoxides slates of New Brunswick.4 In the same year he determined by paleontological evidence that the roofing slates of Granville,

1 Am. Naturalist, vol. 19, 1885, pp. 128-136.

8 Classification of the Cambrian, System of North America., Am. Jour. Sci., 3d aer., vol. 32,1886, p. 145.

3 Second contribution to the studies of the Cambrian faunas of North America. U. S. Geol. Survey 

Bull. No. 30,1886, pp. 13-20.

4 Op. cit., pp. 63,64.
WALCOTT.] GEORGIA TERRANE. 111

Washington County, New York, which includes green and purple slates, 

were of the same geologic age as the Georgia slate.1

The extension of the " Granular Quartz " of the eastern part of New 

York into Dutchess County was described by Dr. W. W. Mather 2 as it 

occurred about Stissing Mountain. He refers to it as the u Granular 

Quartz " and Potsdam sandstone. Within a few years Prof. John 0. 

Smock 3 examined the geological structure of the mountain, stating 

that the quartzite was unconformably superjacent to the Archean 

rocks; and that no fossils had been found in it. In the description of 

the Primordial rocks of the Wappinger Valley, by Prof. W. B. Dwight,4 

mention is made of the quartzite about ^Stissing Mountain, as well as 

the discovery by himself and Mr. C. D. Walcott of Middle 5 Cambrian 

remains in the arenaceous quartzite and limestones on the flanks of the 

mountain. It is thus correlated with the Olenellus beds of the Georgia 

series of Vermont.

At the Ann Arbor meeting of the American Association for the 

Advancement of Science, held in August, 1885, Prof. Dwight 6 announced the discovery of fossiliferous Potsdam strata at Poughkeepsie, 

New York. He says7 :

Lithologically, the rock is here very variable. It is everywhere calcareous, all its 

varieties effervescing freely with acids. It is also everywhere more or less arenaceous, often conspicuously so ; from being compact and massive it changes to a rock 

fissile into thin slabs or to one splitting into the thinnest leaves, which are covered 

with loose sand as they decompose.

This rock passes on the one hand into a smooth fine-grained, argillaceous limestone, 

and then into a very fissile calcareous shale or, on the other hand, into a quartzite, 

somewhat calcareous.

An account of the localities at which the rock occurs and a list of 

eleven species of fossils are given. This paper was published more in detail in the number of the American Journal of Science for February, 

188G, and was accompanied by a map on which the geographic distribution of the Potsdam and related strata are shown.8

Prof. Dwight9 announced in 1889 the discovery of fossiliferous strata

1 Walcott, G. D. Cambrian age of tho roofing slates of Granville, Washington County, New York. 

Am. Assoc., Proc., vol. 35,1887, pp. 220, 221. (Advance sheets published 1880.)

2 Natural Hist, of Now York. Part 1. Geology of New York; Geology of the first (southeastern) 

district. Albany, 1843, pp. 418, 423,430,437.

3A geological recoimoissniico in tbo crystalline rock region, Dutehcss, Putnam, and Wostchestor 

Counties, New York. Thirty-ninth Ann. Rep. State Mus. Nut. Hist., 1880. pp. 100-185.

4 Primordial rocks of tho Wappiugor Valley limestones and associated strata. Vassar Brothers 

lust., Trails , vol. 4, 1887, pp. 200-214. Discovery of additional fos*iliforous Potsdam strata and proPotsdam strata of tho Olenollus group near Poughkeepsie, N. Y Am. Jour. Sci.,3d ser., vol. 34,1887, 

pp. 27-32.

6 Now classed as Lower Cambrian.

"Discovery of fossiliferous Potsdam strata at Poughkeepsio, N. Y.,Am. Assoo., Proc., vol 34, 1886, 

pp. 201-209.

7 0p.cit.,p.205.

8 Kecent explorations in tho Wnppinger Valley limestone of Dutchess County, N. Y., No. 5. Discovery of fossiliferous Potsdam strata at Poughkeepsie, N. Y. (illustrated by map, Plate vi). Am. 

Jour. Sci., 3d ser., vol. 31, 1880, pp. 125-133. Primordial rocks of the Wappinger Valley limestones 

Vassar Brothers' Inst. Trans., vol. 4,1887, pp. 130-141, Plate 1.

9 Recent explorations iu the WappingoT Valley limestones and other formations of Dutchess County, 

N. Y. Am. Jour. Sci., 3d ser., vol. 38,1889, pp. 139-153.
112 THE CAMBRIAN. |Buu,.81.

0

of the Paradoxides zone at Stissiug, Dutchess County. In the limestone and calcareous shale immediately overlying the Oleiiellus limestone, at the south end of Stissiug Mountain, he discovered a fauna 

that is correlated with the* Middle Cambrian or Paradoxides fauna, 

thus establishing the middle member of the Cambrian system in addition to the Lower Cambrian and Upper Cambrian that had been previously found in this region. A plate illustrating the fauna accompanies the paper.

In 1887 Mr. C. D. Walcott1 published a description of the fauna of 

the Upper Tacoriic of Emmons, of Washington County, New York. In 

this a statement of the stratigraphic position of the fauna was made, 

based on the correlation with the fauna of the Georgia slates of Vermont. This was followed in 1888 by an account of the discovery of 

fossiisin the Granular Quartz near Bennington, Vermont.2 The discovery 

was further described in a paper which followed on the Taconic system 

of Emuious,3 where an account is given of the mode of occurrence of 

the "Granular Quartz" in western Massachusetts and Vermont. The 

quartzite is referred to the Middle (now Lower) Cambrian zone, of which 

the Olenellus bearing shales of the Georgia section are the type. A 

description is given4 of the slates and shales, and it is stated the formations of the Upper Taconic have a thickness of 14,000 feet. In these 

the Olenellus fauna occurs more or less abundantly at various horizons. 

An examination of the sections and the fauna of the " Granular Quartz" 

and"Tacouie" shales and slates, shows that the former is stratigraphically 

and faun ally the equivalent of the upper part of the latter; while the 

"Granular Quartz" is a sandy deposit of the shore line, and the shales and 

slates the offshore accumulation of sediments. On the map accompanying this paper the geographic distribution of the "Granular Quartz," 

the " Eed sandrock" of Vermont, and the Georgia slates and their southward extension as the Tacouic slates is represented.

In a tabular view of the American Classification and Nomenclature, 

published in 1888, by Prof. Jules Marcou,5 the Taconic system is divided 

into upper, middle, and lower divisions. In the upper division the 

Potsdam sandstone, Swanton slates, Phillipsburg and Point Levis formations are included. The middle division includes the Georgia formation and the St. John or Paradoxides zone, of New Brunswick, of 

Braintree, Massachusetts, and of St. Mary's Bay, Newfoundland. In 

the lower division are the Chuar and Grand Canon formations of the 

Grand Canon, Arizona, the sandstones of Great Bell Island, and the 

slates of St. John's, Newfoundland. The confusion in this table is not

1 Fauna of the ' 'Upper Taconic" of Einmons, in Washington County, New York. Am. Jour. Sci., 3d 

ser., vol. 34,1887, pp. 187-199.

2 Discovery of fossils in the Lower Taconic of Emraons. Am. Assoc., Proc., vol. 36,1888, pp. 212,213.

3 The Taconic System of Emmons and the use of the name Tacouic in geologic nomenclature. Am. 

Jour. Sci., 3d aeries, vol. 35,1888, pp. 229-242,307-327,394-401. 

4 Op. cit, pp. 241, 242. 

6 American Geological Claasilication and Nomenclature. Cambridge, 1888, p. 75,-
WALCOTT.J POTSDAM SANDSTONE. 113

as great as that of the 1885 paper. The Swanton slates, of Hudson 

age, and the Phillipsburgh and Point Levis formation of Calciferous 

age, are placed with the Potsdam sandstone; while in the Lower Taconic we find the sandstones of Great Bell Island, which are the geologic equivalent of the Potsdam sandstone.

During the summer of 1888 Mr. 0. D.Walcott visited Newfoundland 

and studied 1 a section on Manuel's Brook, Conception Bay, that extends 

from the Archean gneiss up to the Olenellus and Paradoxides zones. 

In this unbroken section it was found that the Olenellus faun a occurred 

at the base and the Paradoxides fauna above. This necessitated a 

revision of the classification of the Cambrian. The Lower Cambrian 

with the Olenellus fauna is at the basej next the Middle Cambrian 

with the Paradoxides fauna, and lastly the Upper Cambrian or Potsdam 

zone, at the summit of which the Dikellocephalus fauna occurs. This 

correlation places the " Bed Sandrock " series, the Georgia shale and 

slate series, the " Granular Quartz," and the " Upper Taconic " of Emuions beneath the Middle Cambrian or Paradoxides zone of the Atlantic 

coast.

In a paper on the fauna of the Olenellus zone 2 a brief historical review is given of the rocks referred to the Olenellus zone in Vermont 

and eastern New York, and also an account of the sections and the distribution of the fauna.

In a paper read before the Geological Society of America, December 

30, 1890, Dr. J. E. Wolff noted the discovery of fossils of supposed 

Lower Cambrian age in the limestones of the East Rutland Valley, Vermont. The limestones rest conformably upon the basal quartzite carrying the Olenellus fauna.3

Potsdam sandstone. The Potsdam sandstone of the Adirondack area 

appears only in a few small outcrops in Vermont and eastern New York. 

According to Prof. C. H. Hitchcock, there are three different localities 

in Vermont: 4 near the Lake Champlain shore in West Haven, Orwell, 

and the east part of Shoreham, in the counties of Addison and Rutland. 

There were none of these of sufficient importance to be indicated on the 

map of 1877. The outcrops in eastern New York are practically a continuation of the Vermont exposures. They occur in the vicinity of 

Whitehall, New York, and south to Fort Ann, Washington County.

In the review of the references made to the " Red Saudrock " series 

of Vermont, frequent mention has been made of its correlation with the 

Potsdam sandstone as well as of the correlation of the u Granular 

Quartz " with the Potsdam sandstone of the Adirondack area. As now 

known, these two belong to distinct geological horizons, as claimed by

1 The stratigraphical succession of the Cambrian faunas of North America. Nature, vol. 38,1888, p. 

651.

2 Walcott, C. D. The fauna of the Lower Cambrian or Olenellus zone. 10th Ann. Eep. D. S. Geological Survey, 1890, pp. 509-703. 

* Bull. Geol. Soc. America, vol. 2,1891, pp. 334-337. 

«Hvpo/oic and Paleozoic rocks. Report on the geology of Vermont, vol. 1,1861, p. 265,

Bull. 81 8
114 THE CAMBRIAN. [BULL. 81.

Dr. Emmons in 1842. As the typical Potsdam sandstone in this district is an extension of the sandstone of the Adirondack sub area within 

its borders, the review of its literature will be united with that of the 

typical Potsdam of the Adirondack district.

The occurrence of the Upper Cambrian or Potsdam zone as distinct 

from the Georgia slate and '* Bed Sandrock," is spoken of in the description of the section crossing the town of Georgia, Vermont,1 where 

mention is made of the discovery of a fauna closely related to that of 

the Upper Cambrian. This is the same horizon referred to on page 17, 

par. 14.

In a description of a section crossing the typical Taconic area of 

eastern New York and western Massachusetts by Mr. C. D. Walcott,2 

the typical Potsdam sandstone is not recognized. It is stated that certain shales designated as Terrane No. 2, may represent the Potsdam 

terrane, or it may be represented by the lower part of the limestones 

of Terrane No. 3, or the upper part of the Quartzite of Terrane No. 1.

CANADIAN EXTENSION.

The Canadian extension of the Northern Appalachian District is from 

the United States boundary northeast to the vicinity of Point Levis, 

Quebec, on the western side of the extension of the Green Mountain or 

Suttou Mountain anticlinal, and from Quebec down the south shore of 

the St. Lawrence River to Cape Rosier, Gaspe". On the eastern side of 

the anticlinal the supposed Cambrian rocks of New Hampshire, crossing the southeastern portion of the province of Quebec, to the Maine 

boundary, are also included.

The first notice of the rocks, subsequently referred to the Cambrian 

in the vicinity of Quebec, was by Dr. J. J. Bigsby.3 He divided the 

strata into three series. First, the slaty series, composed of slates and 

grauwacke, occasionally passing into a brown limestone, and alternating with calcareous conglomerate in beds, some of which are charged 

with fossils; second, the limestone series; third, gneiss. In the beds 

of this conglomerate on the south side of the St. Lawrence he noticed 

the presence of trilobites, encrinites, corallines, and other fossils. He 

considered them above the supposed equivalent of the Carboniferous 

limestone of the English geologists.

In his description of the succession of the strata at Montmorenci 

Falls, Dr. E. Emmous states that the rock forming the falls is a gneiss, 

and in the figure illustrating the section the Potsdam sandstone is shown 

resting unconformably upon the gneiss and subjacent to 'the Trenton 

limestone, but with a conglomerate between it and the Trenton limestone.4 He subsequently correlated the sandstones that are extensively

1 "Walcott, C. D. Second contribution to the studies of the Cambrian faunas of North America. T7. S. 

Geol. Survey, Bull. No. 30,1886, p. 19.

2 The Taconic System of Emmons and the use of the name Taconio in Geologic nomenclature. Am. 

Jour. Sci.,. 3d ser., vol. 35,1888, p. 240.

*0n tbe geology of Quebec and vicinicy. Proc. Geol. Soc., London, vol. 1, 1827, p. 37. 

4 Geology of the Montmorenci. The American Magazine, vol. 1,1841, p. 148.
WALCOCT-.] CANADIAN EXTENSION. 115

used in the construction of buildings, both public aud private, and in 

the fortifications of Quebec, with the gray sandstone terminating the 

Lorraine section of Jefferson County, New York,1 These sandstones 

were subsequently named the Sillery sandstones by Sir W. E. Logan, 

who at first followed the correlation made by Dr. Emmons, and referred 

them to the Lorraine shales or Hudson Eiver group.

In the report of progress for 1843, of the Geological Survey of Canada,3 

an account is given in a very general manner of an exploration by Sir 

W. E. Logan of the rocks on the south shore of the lower St. Lawrence, 

near Cape Eosier; and they are further described in the report for 

1844, as seen from Cape Chat toward Cape Rosier, going down the river. 

This is followed in the report for 1S47-'4S 3 by a description of the rocks 

of the extension of the Green Mountains into Canada, and the strata 

upon the west which are now supposed to be of Cambrian age. They 

were then referred to the Hudson Eiver group, with the possible addition of the Shawangunk conglomerate. In their extension it is stated4 

that these recognized rocks of the Hudson Eiver group have a continuous run from Lake Champlaiu along the south bank of the St. 

Lawrence to Cape Eosier.

In a report on the rocks on the south side of the St. Lawrence, in the 

report of progress for 1849-'50,5 a preliminary description is given of 

five masses of rock met with. They include the dark gray slates, gray, 

green, and occasionally red shales, hard sandstones, and a red and green 

shale that were subsequently largely referred to the Quebec group by 

Sir Wm. Logan, and now, in part, to the Cambrian by Dr. E. W. Ells. 

In a report for 1852-'53 6 a description is given of the strata on the north 

shore of the St. Lawrence between Cap Eouge Eiver and Quebec. At 

the base there is a succession of hard, sandy layers, with softer shales 

that extend along the river shore for some distance, and then thick 

beds of sandstone separated by thinner bands of red and green shales. 

The red and green shales have a great thickness further down the river. 

Mr. Logan says that it would be hazardous to pronounce with confidence what it is, from the probably contorted condition of the strata. In 

regard to the sandstones, however (supposed to represent the Oneida conglomerate), no folds have been detected. They are thought to be about 

900 feet in thickness. This is the first preliminary description of the 

sandstones and shales that were subsequently referred to the Lauzou 

and Sillery series of the Quebec group.7

1 Geology of New York, part 2, comprising the survey of the 2d geological (northern) district. 1842, 

p. 125.

2 [Account of the general structure of an extended area in North America.] Geological survey Canada, 

report of progress for 1843. 1845, pp. 6-13 [Documentary Edition.]

s Logan, W. E. Geological survey Canada, report for progress 1847-'48. 1849, pp. 2-17 [Documentary Edition.]

"Op. cit., p. 17.

6 Logau, W. E. (Eeport on rocks on south side of the St. Lawrence.] Geological survey Canada, 

report of progress for 1849-'50. Toronto, 1850, pp. 32-33.

6 Logau, W. E. [Exploration on the north side of the St. Lawrence, between Montreal and Capo 

Tourmoute.] Geological survey Canada, report of progress for 1852-'53, 1854, pp. 5-74.

7 0p. oik, p. 34.
116 .THE CAMBRIAN. [BULL. 81.

Dr. J. J. Bigsby,1 in describing the geology of Quebec and its environs, states tliat the Potsdam sandstone only occurs distinctly, as far 

as yet known in the neighborhood, at the Falls of Montmorenci ; but 

at Jeune Lorette there are traces of it. He says that 

The sandstone of Montmorenci has been unhesitatingly declared to represent the 

Potsdam rock by the New York State geologists, as well as by Sir Charles Lyell and 

Mr. Logan. With these high authorities I have only to concur. Its geological position is that of the Potsdam sandstone; but its aspect and mineral condition are very 

different from that of Lake Superior and of the Thousand Islands, near Kingston, 

Upper Canada.2

In describing the geology of the Falls of Montmorenci, he says:

The sandstone is plentiful on the east bank of the river above the bridge, and is a 

yard or more thick, as well as on the west bank both above and below the bridge; 

the plane of contact with the enclosing rock being clean and abrupt. It is white, 

brownish red or bright green, in well denned layers. Bowlders of the gneiss occur 

in it.3

A section is introduced in which the Potsdam sandstone is represented as beneath the Trenton limestone, and with the latter resting 

unconfomiably against the gneiss. It is stated that the Potsdam sandstone at this place has not yet been found to contain organic remains.

Dr. Bigsby described the north shore of the St. Lawrence, from Quebec 

to Cap Eouge, as consisting of frequent alternations of gritty gray 

sandstone, and red, brown, and black clay shale. On the south side of 

the St. Lawrence, near Point Levis, the rocks are stated to be formed of 

minute alternations of clay-slate, coarse sandstone, calcareous and other 

conglomerates that were met with on the north side of the river.4

In the report of progress for 1852-'53, published in 1854, Sir W. E. 

Logau 8 describes the red and green shales and green sandstones from 

Cap Rouge to Quebec, considering them to belong to the Hudson Eiver 

group of the New York section.

In a description of the Silurian rocks of the environs of Quebec, the 

same writer 6 states that the only exposure of the Potsdam formation in 

the vicinity of Quebec is at Lorette, where the sandstone is 7 metres in 

thickness and without the fossils which characterize the formation in 

other parts of Canada." The shales and sandstone of the Sillery formation are stated to correspond to the conglomerates of the Oneida formation of the New York geologists. This same view was expressed in 

the geological essay prepared for the Paris Exposition of 1855 by 

Messrs. Logan and Hunt.

From the collections of fossils made by the Geological Survey of Canada at Point Levis during the years 185G-'57, Mr. E. Billings, paleon1 On the geology of Quebec and its environs. Quart. Jour. Geol. Soc., vol. 9,1853, pp. 82-101.

2 0p. cit., p. 84. 3 0p. cit., p. 88. 4 Op. oit., pp. 94, 95.

 (Exploration on the north side of the St. Lawrence, between Montreal and Cape Tonrnieuto.) 

Geol. Snrv. Canada, report progress for 1852-'53,1854, pp. 33,34.

6 (Sur la formation silurique dea environs de Quebec.) Soo. g6oJL France, Bull.,2° s6r.,i vol..l2, 1855,, 

p.505. . '
WAM3OTT.1 CANADIAN EXTENSION. 117

tologist of the survey, decided that the rocks there and those which had 

been associated with them by Sir William E. Logan belonged at the 

base of the Lower Silurian and not at the summit, as had hitherto been 

held. These conclusions were announced by Logan in a letter to Mons. 

J. Barraude published in I860. 1 In this letter the whole Quebec group, 

from the base of the magnesian conglomerate with their accompanying 

magnesian shales, to the summit of the Sillery sandstone, is stated to 

have a thickness of perhaps from five to seven thousand feet. Jt appears to be a great development of strata at about the horizon of the 

Chazyand Calciferous of the New York section.

He says he is-not prepared to state that a typical form of the Potsdam sandstone is present where the shales are in greatest force.

Neither ami prepared to assert its absence, as there are in some places masses of 

granular quartz!to, not far removed from the magnesian rocks of the Quebec group, 

which require farther investigation; but, from finding wind-mark and ripple-mark 

on closely succeeding layers of the Potsdam sandstone where it rests immediately 

upon the Laurentian series, we know that this arenaceous portion of the formation 

must have been deposited immediately contiguous to the coast of the ancient Silurian 

soa, where part of it was even exposed at the ebb of tide. Out in deep water the deposit may have been a black, partially calcareous mud, such as would give the shales 

and limestones which come from, beneath the Quebec group.

In Canada no fossils have yet been found in these shales, but the shales resemble 

those in Avhich Oleni have been found in Georgia (Vermont). These shales appear to 

be interposed between eastward dipping rocks equivalent to the magnesian strata of 

the Quebec group, and they maybe brought up by an overlapping anticlinal or dislocation. We are thus led to believe that these shales and limestones, which may be 

subordinate to the Potsdam formation, will represent the true Primordial zone in 

Canada. 2

In 1803 Sir Win. E. Logan published his great re'surne' of the work 

done by the Geological Survey of Canada from its commencement to 

18C3.3 He describes the northward extension of the Georgia series 

audRedSandrock of Vermont into Canada, stating that they had been 

traced but a short distance when they become faulted out and replaced 

by a later formation.4

The Sillery shales and sandstones, as well as the conglomerate beds 

of Point Levis, Quebec, are described in detail and assigned to about the 

horizon of the Calciferous-Chazy formations of the New York section. 

The Levis and Sillery formations are referred to the Quebec group, and 

the latter series is traced south westward along the western base of the 

Sutton Mountain range. The Levis formation is divided into seventeen 

parts, consisting of alternating calcareous shales, argillaceous shales, 

limestone conglomerate, and gray sandstone. The upper beds consist of

1 Logan, W. TL. Remarks on the fauna of the Quebec group of rocks and the Primordial zone of Canada. Canadian Naturalist,vol. 5,1860, p. 475; vol. 6,1801, pp. 10G-] 20; Am. Jour. Sci., 2d ser., vol. 3], 1801, 

pp. 210-220. Remarqnes sur la fauue des roches du groupe de Qu6bec et sur la zone priinordialo dn 

Canada, Soc. geoL Franco, Bull., 2" s6r., vol. 18,1861, pp. 309-314.

"Am. Jour. Sci., 2d sor., vol. 31, p. 219.

3 Geological Survey of Canada. Report of progress from its commencement to 1863. Montreal, 18C3, 

pp. 083.

'Op.cit.p. 285.
118 THE CAMBRIAN. [BUM,. 81.

red and green shales with thin layers of gray sandstone or qnartzite in 

which Lingula and Obolella were found. At the summit of the red and 

green shales, interstratified sandstones appear and succeed the shales, 

with a thickness of about 2,000 feet, forming the Sillery division of the 

Quebec group (p. 232). Subsequently he ] divided the Quebec group 

into three parts: Levis or lower; Lauzon or middle j and Sillery or upper. The Lauzon or middle division embraces the red, green, and purple slates of the section above and below Quebec and on the island of 

Orleans. The only fossils known were Obolella pretiosa and fragments 

of Lingula. The sandstones and accompanying shales of the original 

Sillery were referred to the Sillery or upper division 'with the exception 

of those separated to form the Lauzon. The Levis, or lower division, 

was distinguished by its yellow, dark and black shales and the presence 

of numerous graptolites and Calciferous-Chazy fossils.

dp to this time none of the rocks of the Quebec group had been 

referred to the Cambrian system, or to an equivalent formation, beneath 

the Calciferous zone of the New York series. Messrs. Billings, Hall, 

and Barrande spoke of the Primordial character of some of the fossils 

of the Point Levis conglomerate, but the series as a whole was referred 

by Mr. Logan to the Calciferous-Ohazy zone.

Sir W. E. Logan also described the conglomerate beds of Bic Harbor and Trois Pistoles on the shore of the St. Lawrence River, where 

bowlders of limestone were found containing fossils of the Olenellus 

fauna.2 The shales in which the bowlders occur are supposed at the 

present time to be of Upper Cambrian age.

The report on the south shore of the St. Lawrence Eiver below Quebec, by Mr. James Eichardson, contains the information that another 

series of rocks came to the surface, differing from those farther to the 

west. He says:

These rocks have heretofore been classed with those of the Quebec group, but they 

appear to underlie them uncouformably, and being in some places marked by fossils 

which Mr. Billings considers to be of Potsdam age, they are now placed in the upper 

part of the Potsdam group. 3

They consist at the summit of a light drab quartz rock with intercalated beds of conglomerate holding limestone pebble? in an arenaceous 

matrix, the whole forming a series 600 feet in thickness. This is superjacent to a series of gray sandstones and iuterstratitied shales with a 

thickness of 700 feet in which near the base a conglomerate occurs 5 

below this a third division of gray limestones and limestone conglomerate occurs in beds of from 1 to 6 inches thick. A species of Salterella was observed in the limestone, and a species of Archseocyathus in 

the shales. The third series is assigned a thickness of 700 feet; and the

'Logan, W. E., Keport of, for 1860. Geol. Survey Canada, report of progress from 1863 to I860,1886, 

p. 4.

2 Geological Survey of Canada, report of progress from its commencement to 1863. Montreal, 1863, 

p.200.

3 Keport on the south shore of the St. Lawrence, below Quebec. Geol. Survey Canada, report progress for 1806, to 1869, 1870, p. 120.
WALCOTT.] CANADIAN EXTENSION. 119

entire section 2,000 feet. A number of species of the Olenellus fauna 

were found in the pebbles of the conglomerate near St. Denis Station 

on the Grand Trunk Eailway, and also at Bic Hnrbor.1

The reference by Mr. Richardson of the rocks mentioned in the preceding paragraph to the Potsdam zone is objected to by Dr. A. E. 0. 

Selwyn.2 He says that after examining a considerable portion of these 

supposed Potsdam rocks, there is in his opinion at present no sufficient 

evidence, either paleontological, stratigraphical, or mineralogical, for 

separating this belt from other very large areas of the Quebec group, 

hitherto assigned, the larger part to the Lauzon, but in some places 

also to the Levis and Sillery formations. He states that on any map 

now published it is best to include the whole of the rocks of this great 

fossiliferous belt in one group, as the data are insufficient to separate the 

Potsdam zone from the other rooks of the Silurian. The group referred 

to is No. I,3 the Lower Silurian. The second is " the volcanic group, 

probably Lower Cambrian." Group No. 2 is described as consisting of 

a great variety of crystalline, subcrystalline, and altered rocks, including red, gray, and greenish siliceous slates and argillites, great masses 

of diorite, epidotic and serpeutinous breccias- and agglomerates, etc.4 

Of the age of this group he says:

If fossils are found I should expect them to indicate a lower horizon than the Levia 

formation, probably not far removed from that of the St. John group and Atlantic 

coast series of Nova Scotia, or Lower Cambrian. 6

This series forms part of the Sillery formation of Mr. Logan.

In speaking of the reference of the Volcanic group to the Cambrian 

Dr. Selwyn quotes from the paper read before the Eoyal Society of 

Canada in May, 1882, as follows: 6

The upper portion of this series was designated " the volcanic belt" from the association with it, especially on the southeast side of the main axis, of a great variety 

of what were considered to be altered eruptive and irruptive rocks, but whether 

the strata forming this igneous belt are more nearly allied to the Lower Cambrian 

than to the Upper Hurouiau is not, fossils being absent, easily determined.

On the map of the Dominion of Canada geologically colored from 

surveys made by the Geological Corps from 1842 to 1882, under the 

direction of Dr. Selwyn, there is quite a broad belt of rocks colored 

Cambrian that extends from Cape Eosier on the Gaspe" Peninsula 

southeasterly along the shores of the St. Lawrence to Point Levis, Quebec. From Point Levis it turns more to the south, extending along the 

western margin of the Archean anticlinal to Mississquoi Bay, at the 

foot of Lake Champlain. A narrower strip is represented as extending

'Op. cit., p. 130.

"Report of observation s on the stratigraphy of the Quebec group and the older crystalline rocks of 

Canada. Geol. Survey Canada, report of progress, 1877-'78, 1879, p. 4A. Can. Nat,, now ser., vol. 9, 

1870, pp. 17-31.

s Op. cit., p. 3A. ''Op. cit., p. 5A. S 0p. cit., p. 6A.

6 Notea on the geology of the southeastern portion of the Province of Quebec. Gool. Survey 

Caniula, report of progress, 1880-'81-'82,1883, p. 2A.
120 . THE CAMBRIAN. (BULL.81.

from the north end of the Archean anticlinal or axis, along the eastern 

side of the latter to Lake Memphremagog. A smaller area is colored 

Cambrian in the southeastern part of the Province of Quebec, near the 

Maine boundary, at the northeastern corner of New Hampshire. In a 

map of a part of the Province of Quebec published in 1887, the distribution of the Cambrian about the Sutton Mountain anticlinal, or 

the Archean axis, extending north from the Green Mountains, is given 

more in detail than in the map of 1882.

ID. the table of the geological formations, accompanying Macfarlane's 

American Geological Railway Guide, Dr. T. S. Hunt places the following groups in the Lower Cambrian, in descending order: 1

Potsdam.

Sillery.

Acadian (Menevian).

Lower Taconic.

This same nomenclature is followed in the list of the geological formations of Canada on page 52.

In a report on the explorations and surveys in the interior of the 

Gaspe" Peninsula, Mr. A. P. Low 2 states that the Cambrian system is 

represented along the Ste. Anne River and along the east and west 

flanks of Table-top Mountain, by gray and black shales, limestones, 

and limestone-conglomerates of the Levis formation. He says:

These form but a small part of the great area of these rocks, which stretches from 

Cape Rosier along the south side of the Gulf of St. Lawrence to Quebec and thence 

through the Eastern Townships into the United States.

In describing the Silurian rocks on a previous page 3 he says the 

limestones rest in places upon a pinkish or gray sandstone of no great 

thickness, which is seen on the Ste. Anne and Matane Rivers and on 

the west side of Lake Mafripedia. This sandstone is supposed to be 

the lowest part of the system.

In his surveys of the eastern portion of the Province of Quebec, Dr. 

R. W. Ells 4 included in the Cambrian the extension to the northeast of 

those rocks described as Cambrian by Dr. Selwyn. As described in the 

reports of the Geological Survey of Canada for 1886,1887, they consist 

for the most part of hard cjuartzite interstratified with mica schists and 

black slates. Dr. Ells also referred the trappean rocks of Broughton to 

the Cambrian. All of this series, as described by Dr. Selwyn and Dr. 

Ells, is unconformably overlapped by the Sillery red slates, conglomerates, and sandstones. It is not improbable that some of the strata 

referred to the Lower Cambrian may prove to belong to that system of 

rocks, but in the absence of fossils it is very uncertain whether the strata

1 Dominion of Canada. (Geological Formations.) Macfarlane's Am. Geol. R. E. Guide, 1879, p. 51.

2 Explorations and surveys in the interior of the Gasp6 Peninsula, 1883. Geol. Surv. Canada, 1882-'83- 

1884, p. 14F.

3 Op. cit., p. 12F.

4 Second report on the geology of a portion of the Province of 'Quebec. Geological Survey Canada, 

new ser., vol. 3,1889, pp. 1K-120K.
WAT.COTT.] CANADIAN EXTENSION. 121

mid or consideration should be referred to the Cambrian or to some 

of the pro-Cambrian series of rocks. In a review of Dr. Ells's work by 

Mr. C. D. Walcott 1 it is suggested that from the occurrence of Lower 

Cambrian fossils (the Olenellus fauna) in grayish limestone interbedded 

with purple, green, and black slates, in Washington County, New 

York, the rocks containing them occupy a similar stratigraphic position 

to those described by Dr. Ells in the Canadian section. Dr. Ells considered that portions of the strata referred to the Lower Cambrian are very 

much like those of the gold series of Nova Scotia, while, in part, they resemble the Cambrian of New Brunswick. Stratigraphically they occupy 

a position between the chloritic and micaceous schists of the Archean 

and the superjacent Sillery. 2

The Canadian extension of the rocks referred to the Cambrian System 

by Prof. C. H. Hitchcock in New Hampshire is represented upon the 

geological map of Canada, published by Sir William E. Logan in 1864 as 

the Quebec group, thus being identified with the Quebec group series 

upon the western side of the Gaspe" limestone series. Eeferences have 

been made to them by various authors who have written upon the geology of the townships of eastern Quebec, but not in a manner to distinguish the strata now referred to the Cambrian.

When describing this belt of rocks in 1886, Dr.E. W. Ells3 states that 

Prof. Hitchcock has referred a belt composed principally of blackish, 

wrinkled slates and schistose sandstones, which form a ridge extending 

northeast from the vicinity of Canaan, between Hall's and Indian 

streams to the Quebec boundary, to the Lower or Cambrian system. 

The strata present a well defined anticlinal structure,which is recognized 

in the adjoining townships of Einberton and Ditton in Quebec, and 

northeast past the outlet of Lake Megantic and onward to the Maine 

boundary. The slates are penetrated by quartz veins, which in places 

have proved more or less auriferous.

In character and aspect the gold-bearing slates of Ditton and the area to the northeast almost exactly resemble, as already intimated, the rocks of the Nova Scotia gold 

series. 4

As far as known no fossils have been found in this series to identify 

the horizon, in either New Hampshire, Canada, or Maine. This is true 

also of the second area inclosed on either side of the Stoke Mountains 

and the Sherbrooke anticlinal. The strata forming the western area 

west of Sutton Mountain anticlinal have already been mentioned.

The presence of rocks of supposed Cambrian age is indicated on the 

geological map of Canada, published in 1882, on the eastern side of 

Hudson's Bay, near the mouth of Big Whale Eiver, and in the vicinity

1 A review of Dr. II. W. Ella's second report on the geology of a portion of the Province of Quebec, 

with additional notes on the "Quebec group." Am. Jour. Sci., 3d ser., vol. 39, 1890, p. 101-115.

a Ells, R. AV. Second report on the geology of a portion of the Province of Quehoc. Gcol. Surv. 

Can;tda, vol. 3,1889, p. 87K.

3 Jli>port on tho geology of a portion of the eastern townships of Quebec. Geol. Surv. Canada, 1880, 

now Her., vol.2, 18R7, pp. 24J, 25J".

"Op. cit., p. 25J.
122 THE CAMBRIAN. [BULL. 81.

of Bichmond Bay. The observations upon which this identification is 

based were made by Dr. Eobert Bell, who explored the east coast of 

Hudson Bay in 1877. He names the series the Manitounuck group, 

correlating it with the Nipigon series north of Lake Superior. By combining the sections of slates and sandstones he obtains a thickness of 

2,800 feet for the entire section on this part of the coast.1

Keferences to the occurrence of rocks of supposed Cambrian age on 

Lakes Mistassini and Mistassinis are made by Mr. A. P. Low in his 

report on the Mistassini expedition. The limestones, owing to the 

absence of any fossil remains, have been referred to the Cambrian horizon on account of their lithologic resemblance to Cambrian rocks of the 

east side of James Bay. 2

A map of Lake Mistassini accompanies the report, on which the 

boundary between the Laurentian and supposed Cambrian formations 

is traced.

Dr. George M. Dawsou tabulates the formations; he refers to the 

Cambrian in Ontario and Quebec as follows: 3

3Z>. Sillery and Levis.

3a. Calciferous.

2c. Upper and Lower Potsdam.

2&. Keweenian.

2a. Animikie.

SOUTHERN APPALACHIAN DISTRICT.

The Southern Appalachian district includes the outcrops of strata 

referred to formations of the Cambrian group in northern and central 

New Jersey, southeastern and southern central Pennsylvania, western 

Maryland,Virginia, and North Carolina, eastern Tennessee, northwestern Georgia, and northeastern Alabama.

NEW JERSEY.

In a table showing the geologic succession of the lower Secondary 

or Appalachian rocks as they occur in New Jersey, Prof. Rogers 4 

places as No. 1 of the series of formations a compact and very quartzose sandstone, of light bluish gray color, approaching to white. He 

discovered the formation in only three orfour small isolated areas along 

the western outcrops of the Primary rocks. Prof. Cook refers to this 

sandstone lying upon the gneiss as the u Potsdam sandstone " as known 

in New York. It is only a few feet in thickness.5 In a subsequent report 

a sketch is given of a section at Franklin Furnace, which shows the sanddeport on an exploration of the east coast of Hudson's Bay, 1877. Geol. Surv. Canada, Kep. Prog, 

for 1877-78. 1879, p. 17C.

8 Report of the MiBtassini Expedition, 1884-'85. Geol. and Nat. Hist. Surv. Canada, new ser., vol. 1, 

1885, p. 31D.

s Macfarlane James: An American Geological Hallway Guide. Seconded., 1890, p. 58. 

* Description of the Geology of the State of New Jersey, being a final report. Philadelphia, 1840, p. 45. 

B Report of Prof. George H. Cook upon the geological surveyof Now Jersey, and its progress during 

the year 1863. 1864, p. 6, par. 0.
WALCOTT.] NEW JERSEY AND DELAWARE. 123

stone resting unconforraably on the gneiss and passing conformably beneath the superjacent Magnesian limestone. 1 There are also doubtfully 

included under the "Potsdam sandstone" several outcrops of quartzite and conglomerate, and the conglomerates and sandstones of the 

Green Pond Mountain range. On the large geological map of northern 

New Jersey, published in 1874,2 the " Potsdam sandstone" includes 

shales, sandstones, slaty grits, quartz rock, and the Green Pond Mountain conglomerate; this entire series is represented by one color, 

extending on the trend of the Green Pond Mountain range from the 

New York boundary southwesterly into the central portion of Morris 

County.

In the annual report for 1884 the Green Pond Mountain rocks are 

included with the "Devonian and Silurian rocks." 3 This leaves the 

so-called " Potsdam sandstone " as the only Cambrian formation within 

the State. The following year reference is made by Prof. Cook4 to the 

contact phenomena with the Paleozoic rocks. In New Jersey one point 

is at " Owen's Island," in Sussex County, two-thirds of a mile south of 

the State line, as described by Prof. Eogers in his report of 1830. At 

this point the sandstone dips 20° northwest, and the Archean 70° to 

the southwest. Near Franklin Furnace a similar unconformity occurs, 

and the same conditions appear persistent along the entire northwestern 

margin of the highlands in New Jersey, though no other actual contact 

has been observed along this line.

In a paper presented to the Geological Society of America December 

31,1890, Prof. Frank L. Nason stated he had found fossils of Lower 

< Cambrian age in the quartzite resting on the pre-Paleozoic rocks at 

Hardistonville, Sussex County, New Jersey, and at Franklin Furnace, 

in the same county. He also discovered fragments of a species of 

Kutorgina in the superjacent limestone.5

DELAWARE.

In the northwestern corner of the State of Delaware there is a triangular area of sandstone referred to the " Potsdam " sandstone by Mr. 

Fred. D. Chester. He states that it extends into Pennsylvania, and is 

best exposed beyond the State line.

At Niviirs limestone quarry a mass of qnartzite forms what is clearly an anticlinal 

fold, over which is a corresponding anticlinal of Magnesian limestone. 6

The extension of this sandstone into Pennsylvania is shown upon the 

map of Chester County, Pennsylvania, where it occurs in the township 

of London.

1 Geology of Now Jersey. Newark, 18C8, p. 72.

3 Cook, Goo. U. Geological Survey of Now Jersey. (Map of) northern New Jersey, showing the 

iron-ore and limestone districts. 1874, in two sheets.

3 Cook, Geo.H. Geological Survey of New Jersey. Annual report of the State geologist for the 

year 1884. 1884, p. 29.

4 Contact phenomena with the Paleozoic rocks. Geological Survey of New Jersey. Annual Report 

of the State Gool. for 1885. Trenton, 1885, pp. 53-55.

6 Unpublished.

6 Preliminary notes on the geology of Delaware Laurentian, Paleozoic, and Cretaceous areas. Phila. 

Acad. Sci. Proc., vol. 30, 1884, p. 248.
124 THE CAMBRIAN. BULL. 81.

PENNSYLVANIA.

In the second annual report of the State geologist of Pennsylvania, 

Prof. H. D. Kogers summarizes in a table the order of stratification, 

the geographical position, composition, and thickness of the lower 

Secondary formation in Pennsylvania, east of the Susquehauna Eiver.1 

The description of formation No. I, or the sandstone of the South Mountain, is as follows:

la the ascending order, the first formation which we meet with, reposing on the 

primary rocks of the South Mountain, * * * is a remarkably compact and rather 

fine-grained sandstone, usually white or of some light shade of gray. * * * The 

formation ranges, according to my present helief, from the Delaware, at Eastou, more 

or less interruptedly across the State to the Maryland line, pursuing an undulating, 

irregular belt, coinciding with the northern and northwestern side of the chain of 

hills most commonly called in this State the South Mountain, the prolongation of the 

Highlands of New York and of the Blue Ridge of Maryland and Virginia. 2

It contains, as far as yet examined in Pennsylvania, very few organic remains, the 

best defined species discovered in it being a marine plant, indicative of the oceanic 

position into which the materials of this stratum were originally swept.

I have satisfied myself that this rock is not confined to the Appalachian region of 

Pennsylvania, but that it possesses a prodigiously extensive range, not only through 

Maryland and Virginia, but in a contrary direction through New Jersey and New 

York, and I believe beyond those limits, constituting everywhere the lowermost formation of the widespread Secondary strata which it encircles in a somewhat interrupted belt, following the primary boundary of these rocks from Tennessee to Lake 

Champlain, and thence northwestward to the northern shores of Lake Huron and 

Lake Superior.3

Prof. Rogers recognized the sandstone at many points in New Jersey 

and New York, and considered it identical with the formation in northeastern New York, described by Prof. Eaton under the name of Calciferous sandrock,4 and states that it is probably the same stratum 

 which Dr. Bigsby has mentioned as existing on the north side of Lake 

Huron.5 In the table showing the order of stratification, formation No. 

I is assigned a probable thickness of 1,000 feet.

A description is given in the third report 6 of the geographic distribution of the sandstone as it occurs in the various counties of the southeastern portion of the State.

In Northampton and the eastern corner of Lehigh the sandstone * * * is subordinate in importance to the gneiss and other primary rocks on which it rests. 7

1 Second Annual Keport 011 the Geological Exploration of the State of Pennsylvania. Harrisbtirg, 

1838, oppo. p. 19.

2 Op. cit.,p.21.

"Op. cit.,pp.22,23.

4 The Potsdam sandstone was not differentiated from the calciferous sandrock by Eaton. He included the sandstone and the superjacent calcareons sandstone, under the common name of calciferous 

anndrock, as one formation.

6 Op. cit.,p. 23.

"Ko^ers, Henry D. Third Annual Report of the Geological Survey of the State of Pennsylvania. 

Ilarrisbnrg, 1839, pp. 14-10.

7 0p.cit., p. 15.
WALCOTT.J PENNSYLVANIA. 125

In the fourth report1 formation. No. 1 is spoken of as the extensive 

slate and sandstone formation constituting u The lowest member of our 

oliler Secondary or Appalachian rocks." The slates of the Pigeon 

Jlills are referred to the lowest Secondary formation of the State, and 

the strata comprise different portions of formation No. I, consisting of 

dark slate and alight colored sandstone. The stratigraphic succession 

of the various beds referred to formation No. I of South Mountain, southwest of the Susquehanua, is given in detail. The intercalated limestone 

bed is considered to belong to the upper part of the division, 2 and there 

is a bluish slate interstratified in the sandstone. In the report of the 

following year3 the geographical range of the rocks of the South Mountains from the Delaware to the Schuylkill is outlined. The white and 

gray sandstone of formation I is not a continuous stratum in the belt 

of the South Mountains where they traverse Northampton and Lehigh 

Counties, but it is very probable it occurs at the base of all the primary 

ridges, buried under a deep covering of loose diluvium.4 Mention is 

made of its various points of outcrop and its occurrence in Berks 

County, and many details are given of the distribution of the sandstone and the mode of its occurrence in relation to the subjacent primary rocks.

In his grand summary of the geology of Pennsylvania, Prof. H. D. 

Rogers gives a synoptic description of the Primal series or " Potsdam 7' 

sandstone of New York, as follows : 5

The Primal series, under its-fullest and most diversified condition, or that which it 

wears in the Appalachian chain in Pennsylvania., Virginia, and Tennessee, is a thick 

fourfold group composed of two slates and two great arenaceous rocks in alternation: 

(1) The highest or Primal newer slate is a greenish and brownish talco-argillaceous 

slate, sometimes very soft and shaly. In Pennsylvania it has a thickness of about 

700 feet. (2) The next, thePrimal white sandstone, is a compact, white and yellowish, 

line-grained, vitreous sandstone, often containing specks of kaolin. This rock, which 

is of easy recognition and of an immense range, has a thickness in some parts of the 

Blue Ridge of Virginia of at least 300 feet. This is the Potsdam sandstone of New 

York. (3) The Primal older slate is a brown and greenish gray sandy slate, containing much feldspathic and talcose matter. It has hitherto disclosed no fossils. The 

thickness of this bed in the Atlantic slope in Pennsylvania is several hundred feet, 

and in the Blue Eidge of Virginia is not less than 1,200 feet. (4) ThePrimal conglomerate, the lowest of the yet distinctly recognized formations of the Prim miseries, 

is a heterogeneous conglomerate of quartzose, feldspathic, and slaty pebbles, imbedded in a talco-silicious cement. The thickness of this rock in Virginia and Tennessee, north of which it has not been discovered, is at least 150 feet.

In New York and the Northwestern States this series presents a materially different 

type, the Primal white sandstone being almost the sole representative.

Thickness. The thickness of the entire series is considerably more than 2,000 feet.

1 Rogers, H. D. Fourth Annual Report on the Geological Survey of the State of Pennsylvania. 

Harrisbnrg, 1840, pp. 33-35.

2 Op. cit.,p.41.

3 Rogers, H. D. Fifth Annual Report on the Geological Exploration of Pennsylvania. Harrisburg, 

1841, pp. 16-26.

* Op. cit., pp. 26,27.

* The Geology of Pennsylvania. Philadelphia, 1858, vol. 2, pp. 751,752.
126 THE CAMBRIAN. [BULL.81.

Geographical distribution. In its geographical distribution this primal series ranges 

coextonsively, or nearly so, with the other formations of the older Paleozoic division 

to be presently traced; that is to say, it shows two great continuous outcrops, one 

stretching southwest along the Appalachian chain and the other west from the St. 

Lawrence, through New York, Canada West, Northern Michigan, Wisconsin, and 

Minnesota beyond the Mississippi. It is probably likewise brought to the day in 

the anticlinals of Missouri, Arkansas and Texas, which elevate the gueissic strata on 

which it rests.

The only fossils found were a peculiar fucoid in the newer Primal 

slate, annelid borings in the Primal white sandstone, " one or two 

brachiopodus mollusks, especially lingula. In Wisconsin and other 

northwestern localities this formation contains several species of trilobites, and abounds in lingulae, obelus, and an orbicula." 1 Trilobites 

were also found on Lake Ohamplain.

Under the heading of " Equivalents " is the following:

These strata seem to be on the horizon of the lower Festiniog group or lingula 

flags of England, and equivalent to the obolns and lingula sandstone of Sweden and 

Eussia. They represent, too, the primordial zone of Bohemia, and are therefore on 

the horizon of the very dawn of discovered life.2

This summary of Prof. Rogers gives his information respecting the 

Primal series in Pennsylvania, Virginia, and Tennessee up to the time of 

publication. Under the heading of " Depositions and disturbances of 

the Primal period," he discusses the probable conditions under which 

the sediments were deposited, and sums up the period as one of vast 

duration j " an enormous age of quiet sedimentation with almost no 

life in the wide turbid sea." 3 The paleontological record for the Primal 

series is given a very few words : Three or four fossils known in the 

white sandstone, and a vaguely defined plant in the subjacent shale 

in the Appalachian region. But in Wisconsin, the white sandstone 

imbeds, on a succession of thin floors, some seventeen more species. 

Two of these are identical with those of the eastern outcrop, so the 

total number of species known at that date was eighteen. The distribution of the Primal series in Pennsylvania is tabulated in volume I4 and 

local details are given in the description of the various counties in which 

outcrops of the rocks and slates occur.

On an accompanying geological map the geographic distribution of 

the Primal series is delineated. As a whole it extends with many interruptions diagonally across the southeastern portion of the State, 

from South Mountain in Adams County to Northampton and Bucks 

Counties, on the Delaware Eiver.

Two maps of sections also accompany the report of 1858. On the 

line of section No. 2, the Primal is represented, in Northampton County, 

at Frey's Run and along Durham Creek to the Delaware River. At 

Attleborough, in Bucks County, a synclinal of the Primal sandstone 

is represented as occurring in the midst of the older Primal slate.

»0p. cit., p. 751. 2 Op. oit., p. 752. «0p. cit., p. 781. * Op. oit., pp. 122,123.
VTALCOTT.] PENNSYLVANIA. 127

Section No. 3 crosses the Primal slate in Berks County and represents the Primal sandstone dipping southeasterly from the Primal 

slate forming Mount Pleasant. The Primal sandstone is shown again 

in Montgomery County at Barren Hill and it is placed in the midst of 

11 Primal mica slate."

Section No. 4, in crossing Lancaster and Chester Counties, passes 

through the Primal series atNeversink Hill, near Heading, and also at 

Welsh Mountain, where the Primal sandstone is represented as forming 

a low anticlinal.

On the line of section No. 5, the Primal sandstone occurs to the west 

of the Primal slates and gneiss that form Millbough Hill in Berks 

County. In Lancaster County, on the line of the same section, the 

sandstones occupy the south end of Welsh Mountain. In Mine ridge 

the Primal slates and gneiss are represented as much distorted, while 

the sandstone forms an anticlinal and synclinal axis.

Sections Nos. 7 and 8 cross £he South Mountain in Adams and York 

Counties ; and the entire section of the mountain is represented as 

Primal, as stated in the text. The rocks of Pigeon Hills, to the southeast in section 7, are also referred to the " Primal" and to the" Primal 

slate, altered and crystalline;" and the same reference is made of the 

southwestern extension of the slates of the Mils where crossed by section 8.

1 have been unable to find any account of original researches upon 

the Primal rocks during the period between, the final report of Prof. H. 

D. Rogers and the renewal of their study by Prof. J. P. Lesley in 1873.

In a paper by the latter, on the iron ore of the South Mountain of 

Cumberland County, a diagrammatic sketch is given of a cross-section 

of the county at Carlisle, in which the " Potsdam " sandstone rests on 

the gneiss for a long distance.1 On the following page a sketch of a 

section shows the sandstone, resting on the Azoic slates and gneiss; 

and beneath is a series of iron ore bearing slates that, in turn, are subjacent to the Calciferous sandstone and Trenton limestone.

In describing the Cornwall iron mines and some related deposits, in 

Pennsylvania, Dr. T. S. Hunt2 refers Prof. Bogers's Primal slate of the 

mines to a portion of the Lower Taconic series of Emmons and beneath 

the horizon of the Potsdam sandstone of the New York system. This 

reference carries with it the ores which are found in Pennsylvania 

along the borders of the Mesozoic and Eed Sandstone formations of this 

portion of the State.

In another paper Dr. Hunt notes the discovery by Prof. Prime of a 

species of Monocrateriou, in the Auroral limestone of Pennsylvania, 

and says:

'The iron ores of the South Mountain along tho line of the Harrislmrg and Potomac Railway in 

Cumberland County, Pennsylvania. Am.Phil. Soc. Proc., vol. 13,1873, p. 4.

2 Tho Cornwall iron mine and some related deposits in Pennsylvania. Am. Inst. Mining Eng., Trans., 

vol. 4,1876, p. 320.
128 THE CAMBRIAN. [BULL.81.

These same limestones in Pennsylvania, which belong to the Lower Tacouic series 

of Emmons, have also afforded, an undescribed species of Lingula. 1

In reporting on the Paleozoic rocks of Lehigh. and Northampton 

Counties Mr. Fred. Prime, jr., states that the very lowest beds of the 

Potsdam sandstone are actually pudding-stones, containing pebbles the 

size of a man's fist and larger, and fragments of red, unaltered orthoclase. The upper beds are composed of a hard, compact quartzite containing greater or less quantities of feldspar nodules. The sandstone 

often, as elsewhere, contains Scolithus.2 He gives the geographic distribution of the sandstone as found about the South Mountain in the 

two counties mentioned. Of the upper Primal slates he says:

Next above the Potsdam sand stone occur hydromica slates, which Rogers has called 

the Upper Primal slates, but which really form a portion of the No. II limestone, 

and gradually pass into this. They overlie the Potsdam conformably and are far 

more persistent in their occurrence.3

In the limestone he found specimens of the genus Monocrateriou in 

Lehigh County, specimens of Lingula, and a single specimen of an 

orthoceratite.4 In the vicinity of Allentown and Bethlehem the sandstone is about 25 feet thick. The contact between the gneiss and the 

sandstoneis distinctly seen about 2 miles from Allentown, on the Lehigh 

Valley Eailroad track. (Prof. Prime's paper was also printed in the 

American Journal of Science, under the following title: " On the Discovery of Lower Silurian Fossils in Limestone Associated with Hydromica Slates, and on other points in the Geology of Lehigh and Northampton counties, Eastern Pennsylvania.") 5

The species of Monocraterion was described and illustrated by Prof. 

Prime in 1878.6 It is stated to be from, the Siluro-Cambrian limestone.

Prof. Eogers referred nearly all of the strata of the South Mountain, 

southwest of the Susquehanua River, to the Primal series. He says:

In its geological constitution this tract is without much variety, for it contain 

scarcely any rocks except those of the Primal series. 7

He describes the ridges as composed of the Primal white sandstone 

and the intervening valleys and plateaus of the Primal upper slate. 

These strata are represented as very much disturbed and extensively 

metamorphosed. This view is not accepted by Dr. Persifor Frazer, who 

says that in his report of 1875 (Second Geological Survey of Pennsylvania, CC) it is clearly shown, both in the text and in the graphic 

illustrations, that the Potsdam or Primal formation of Rogers is wanting over all that country with the exception, perhaps, of scattered 

patches on the northwestern flank of the South Mountain chain.8

1 On the history of the crystalline stratified rocks. Am. Assoc., Proc., vol. 25,1876, p. 208.

2 On the Paleozoic rocks of Lehigh and Northampton Counties, Pennsylvania. Am. Phil. Soc., Proc., 

vol. 17,1878, pp. 248, 249. 

3 Op. cit.,p.249. « Op. cit., p. 251.

6 Am. Jour. Sci., 3d ser., vol. 15,1878, pp. 261-269. 

8 2d Geol. Sur., Penn., DD, 1878, pp. 79-80.

7 The Geology of Pennsylvania. Philadelphia, 1858, vol. 1, p. 203.

8 Frazer, Persifor, jr. (On the relations of the South, l^qqutaiu rocks in Pennsylvania.) Am. ID at. 

Mining Eng., Trans., vol. 7, 1870, p. 336,
WALCOTT.] PENNSYLVANIA. 129

In noting the discovery of the Martic anticlinal in Lancaster County, 

Dr. Frazer calls attention to its exposing fundamental gneiss and granatoid beds in the new railroad cuttings along the left bank of the Susquehanna River and how it sheds off to the north and to the south at 

least 16,000 feet of Primal (Cambrian ?) slates.1 In a special report 

upon the geology of Lancaster County the same writer describes the 

character and mode of occurrence of the " Chikis" quartzite. The 

actual thickness of the quartzite above water level is not much over 

300 feet.2 Between the limestones and the quartzite there is, he says 

A vast series of hydro-mica schists and'decomposed argillaceous slates, which insensibly grow in the deep more and more chloritic until this mineral lends its color 

as well as its name to the larger part of the whole formation, but generally the 

chloritic series is divided from these nacrites by a quartzite.3

He says further:

A vast series of slates intervene between the lowest rocks of all oil the Susquehanna and the formation last described.4

As the result of his survey of the southern parts of Montgomery, 

Bucks, and Philadelphia Counties, Mr. Chas. E. Hall5 decides that the 

South Valley Hill hydromica and chlorite slates, which were considered by Prof. Rogers as equivalent to his Primal of the North Valley 

Hill, are not altered Primal slates, but no other than a series of slates 

overlying the limestones of No. II or the slates of the Hudson Period. 

He also gives a description of the Primal quartzite of Rogers, speaking 

of it as the Potsdam sandstone." He gives his opinion of the age of 

the sandstone known as the Edge Hill Rock, in Chester County, as 

follows: "The Itacolumite, or Edge Hill Rock, I consider proven, beyond dispute, to be the equivalent of the Potsdam sandstone." 7

In a memoir upon the geology of the southeastern portion of Pennsylvania, Dr. Persifor Frazer gives a summary of the general characters and geographical distribution of the Primal quartzite and the subjacent and superjacent schists. The upper division of the .Primal of 

Rogers is referred to No. Ill or Auroral, and the chloritic schists, subjacent to the quartzite, are referred to the Huronian, the quartzite alone 

representing the Primal or Potsdam of Rogers.8 The geographic distribution of the formation in Chester, Lancaster, York, and Adams 

Counties is represented on the map accompanying the memoir.

Prof. Lesley, in his description of the geology of Chester County, 

after the surveys of Messrs. Rogers, Frazer, and Hall 9 writes:

1 fNote on the Martio anticlinal and on ripple marks on a slab of limestone]. Am.Phil. Soc.,Proc., 

vol. 17,1878, p. 725.

2 The geology of Lancaster County. Second Geol. Survey Penn., Rep. Prog, in 1877, CCC. Hurrisburp, 1880, p. 7.

3 Op. cit., p. 5. * Op. cit., p. 8.

6 The geology of Philadelphia County and of the southern parts of Montgomery and Bucks. Second 

Geol. Survey Pa., C6., 1881, pp. xvii-xviii, 93. 

0 Op. cit., pp. 7,8. ' Op. cit., p. xvii.

8 Memoire sur la Geologie do la partie snd-eet de la Pennsylvanie. Lille, 1882, p. 75.

9 The geology of Chester County, after the surveys of Rogers, >'razer, and Hall. Sjecond. G-e,ol. Sur,.. 

Penu.,CCCC; 1883, p.viii.

Bull, 81 9
130 THE CAMBRIAN. [BULL.SL

Dr. Frazer divides the Potsdam sandstone formation into an upper and a lower. 

# » * rj< ue upper, or Kennett rock division, he identifies with Mr. Hall's Edge Hill 

rock.

The lower is the Toughkenamon division. Dr. Frazer himself says 

that the latter, or the lower division, "is composed of weathered particles 

of a gneiss or syenite loosely compacted and laminated." The second or 

Kennett rock is the upper division and u it is a thin-bedded rock, lying 

in plates of fairly parallel sides, composed of fragments of white limpid 

quartzite, and is generally large-grained."'

Prof. Lesley quotes Prof. Eogers's description of the Primal series as 

it occurs at various localities in the county, together with many of 

Dr. Frazer's observations; stating that he described three principal and 

a few very subordinate and doubtful areas of the Primal rock north of 

the Chester Valley. One important conclusion of Dr. Frazer's is here 

quoted:

In mentioning thus the " Primal," the quartzite and quartzose sandstone alone are 

considered here. It will be seen further on that abundant evidence sustains the view 

that the greater part if not all of the weathered feldspar porphyries, conglomerates, 

&c., in the townships both north and south of the Chester Valley are really Lower 

Potsdam. The effect of this would be to add a border of these rocks to the area of 

the (silicious) Potsdam as at present indicated on the map, and thus contract by this 

much the remaining area of real Azoic or Hypozoic. 2

The report of Mr. E. Y. D'lnvilliers upon the geology of the South 

Mountain belt of Berks County contains an extended description of the 

"Potsdam" sandstone, or No. 1 of Bogers's classification. The opening 

paragraph throws a doubt upon the correlation that has been made of 

this lower sandstone with the Potsdam sandstone of New York:

It would be safer to name this formation the Reading Sandstone; but in the descriptions of its outcrops along the Little Lehigh, the Lehigh, and the Delaware Rivers, 

in vol. i of this report, it has been called Potsdam Sandstone, taking for granted that 

any sand formation underneath the Magnesian limestones of the Great Valley must 

be the same sand formation which in northern New York underlies the Corniferous 

[Calciferous?], Chazy, and other limestones of the Mohawk Valley.3

The lower sandstone or conglomerate and the lower Primal slates of 

Rogers were not recognized in Berks County.

The lowest bed of the sandstone, always seen resting on the gneiss, is a coarse conglomerate of angular quartz rock fragments of all sizes in a silicons paste. * * * 

The term sub-Potsdam conglomerate would express its position underneath the Potsdam quartzite ivhite sandstone proper, belonging to it by conformity, and separated 

from the gneiss by nonconformity.4

A detailed description of the outcrop of the sandstones and their 

general character follows. Certain areas of slate exist in places between the sandstone and the Magnesian limestone and are referred to 

the Primal series. Where the slate is not present the limestone is iin1 Geological notes in the several townships of Chester County. Second Geol. Surv. Penn. The geology of Chester County. C4,18S3, p. 307.

2 The geology of Chester County, after the surveys of Eogers, Frazer, aud Hall. Second Geol. Surv. 

Penn., CCCC; 1883, p. 159.

8 The geology of the South Mountain Belt of Berks County. Second Geol. Surv. of Penn., D3,1883, 

vol. 2, p. 99.

 Op.oit.p.lOO.
WALCOTT.] PENNSYLVANIA. 131

mediately above the Potsdam sandstone. "Its place in the series is 

next above the Potsdam sandstone formation No. I." l

In a lecture upon the geology of Philadelphia, Prof. H. Carvill Lewis 

describes the Primal slates and Potsdam sandstone as follows:

On top of the gneiss and at the base of that great group of fossiliferous rocks known 

as the Paleozoic System, is a peculiar formation in the middle strata of which occur 

the oldest fossils yet found in the vicinity of Philadelphia. The lower part of the 

formation is the pale sandy slate which forms Edge Hill and Barren Hill, and the 

northern base of Chestnut Hill. The slates are closely folded and stand often almost 

perpendicular. * * * A sandstone, which from its great development at Potsdam, 

N. Y., has been named from that place, overlies the slates and often contains long 

tubular fossils, known as Scolithus lineariu, which appear to be the casts of wormholes. * * * On top of this fossiliferous sandstone is a series of soft, iron-bearing 

shales,, often decomposed into variegated clays, carrying extensive beds of iron ore 

(limonite).2

The "Potsdam" sandstone is described by Prof. Fred. Prime, jr., as 

it occurs in Lehigh and Northampton Counties.- It rarely exceeds 25 

feet in thickness, and there are no underlying rocks of any thickness 

between it and the unconformably subjacent Laurentian rocks. The 

Primal upper slate of Eogers is classed with the Siluro-Cambriau limestone/'

Prof. J. P. Lesley's hand atlas of the sixty-seven counties of Pennsylvania contains a description of the rocks referred to the Potsdam 

quartzite, No. I, of Bogers, in each of the counties in which they occur; 

and the geographic distribution is shown upon the maps of the counties. 

The text presents the best general statement of the distribution of the 

strata now referred to the Cambrian in Pennsylvania that has yet been 

published.4

Prof. Lesley's rdsume" was followed in 1886 by an important contribution by Dr. Persifor Frazer entitled " A sketch of the Geology of 

York County, Pennsylvania." In adopting the classification of the 

Geological Congress for the system he places under the heading "Cambric" the Hellam quartzite or Potsdam sandstone.5 The lower series 

or talcose slates of Bogers are considered in all probability as identical 

with the Azoic schists; and it is stated that abundant instances occur 

of the uiiconformable contact of the quartzite upon the supposed equivalent schists in Chester County. On the geological map accompanying 

this memoir the details and distribution of the Potsdam formation are 

delineated. The talcose schist of Bogers, or the upper member of his 

Primal series, is referred to the "Siluric" as "hydro-mica schists.'"5

Dr. T. Sterry Hunt objects to the interpretation of Prof. Bogers, that

1 Op. cit., p. 137.

"The geology of Philadelphia. Franklin Inst. Jour., 3d tier., vol. 85, 1883, p. 425.

3 Geology of Lehigh and Northampton Counties. Second Geol. Surv. Penn., D3, vol. 1,1883, pp. 210, 

212.

4 A geological hand atlas of the sixty-seven counties of Pennsylvania, embodying the results of the 

Verity field work of the survey, from 1874 to 1884. Second Geol. Surv. Peim., X, 1885, pp. cxii.

8 General notes. Sketch on the geology of Tjfork County, Pennsylvania. Am. Phil. Soc., Proc., vol. 

23, 1886, p. 398.

 Op. cit, p. 400.
132 THE CAMBRIAN. LBULL.SL

the Primal sandstone. Auroral limestone, and Matinal shales of central 

Pennsylvania are represented in southeastern Pennsylvania. He criticises the correlation upon the evidence of the presence of Scolithus linearis, stating that he has shown it to be very distinct from that found 

in the Potsdam sandstone. The argument for this is given in his " Azoic 

Bocks of Pennsylvania." 1 In a later publication Dr. Hunt concludes 

that 

There is, in fact, up to this time, no evidence that the typical Potsdam sandstone 

and Calciferous sandrock of northern New York exist in eastern Pennsylvania; but 

on the contrary there are many reasons for supposing that in this region, as in eastern Canada and along the eastern side of the Champlain and Hudson River Valleys, the 

period of these two subdivisions of the New York system is represented by the First 

Graywacke of Eaton, the Upper Taconic of Eninious, which, as will be shown farther 

on, is now recognized as contemporaneous with the typical Potsdam and Calciferous 

subdivisions. Rocks supposed to represent this Graywacke series are found in the 

great valley of Pennsylvania, and these, together with the divisions immediately preceding them namely, the Primitive quartz rock, the Primitive lime rock, and the 

transition argillite which constitute the Lower Tacouic of Eminons are, as we shall 

endeavor to show, represented by the so-called Primal, Auroral, and Matinal of the 

southeastern area.2

He refers the sandstone, limestone, and shale to his pre-Cambrian 

Taconian system, correlating the formations with the Granular quartzite, 

Granular limestone, and Transition argillite of the eastern New York 

section. This correlation, made long before by Prof. Eogers, is sustained by the latest observations. The " Granular quartz " of Baton's 

section is known to be of Lower Cambrian age; the limestone, of the 

Trentou-Ohazy horizon, and the argillite is referred to the Hudson terrane. If the correlation based upon lithologic characters and stratigraphic position by Messrs. Eogers and Hunt be correct, then the quartzite of southeastern Pennsylvania is of Cambrian age, and the limestones, 

with their super]acent shales and schists, are the equivalents of the 

Trenton and Hudson terranes.

The statement that the Upper Taconic of Eminons is contemporaneous with the typical Potsdam and Calciferous subdivisions is no longer 

sustained, as the Upper Taconic of Einmons is mainly the Lower Cambrian of the New York section.

In a discussion on the rocks of Pennsylvania and New York, Mr; T. 

D. Band 3 mentions the Cambrian of Chester Valley, near Philadelphia, 

and, as undetermined, the hydro-mica schist of the South Yalley Hill. 

He states that the Potsdam really exists in between the schist and the 

limestone, which refers the schist to the Archeau. The sandstone is 

very thin, but it rests upon the Laurentian shore of the ancient ocean, 

which explains the differences of thickness as compared with the rocks 

to the northwest.

1 Special report on the trap dikes and Azoic rocks of southeastern Pennsylvania. Second Geol. 

Surv. Pa., E. 1878, pp. 134-139.

2 The Taconic Question in Geology. Mineral Physiology and Physiography. A second series of 

chemical and geological essays: 1886, p. 534.

3 A discussion on the rocks of Pennsylvania and New York. New York Acad. Sci., Trana., vol. 8, 

1889, pp. 50,51.
WALCora.1 MARYLAND AND VIRGINIA. 133

MARYLAND.

A brief description is given by Prof. P. T. Tyson, in his first report,1 

of the rocks in Maryland referred to the Primal series of Eogers. Two 

formations are referred to the Primal: (1) a hard sandstone; and (2) a 

slate, varying in color from gray to brownish and greenish. On the 

map accompanying the report the geographic distribution of the Primal 

series is indicated.

VIRGINIA.

One of the earliest attempts to differentiate, by.lithologic characters, 

the formations of the Blue Kidge of Virginia is on the map of a section 

crossing it east of Winchester.2 The Transition, or blue limestone, is 

represented as passing beneath the limestone shale that, in turn, dips 

beneath a gray schistose rock. This section is of interest only when 

interpreted by the later sections of Prof. Eogers.

Prof. William B. Eogers describes in the Second Eeporfc of the Progress of the Geological Survey of Virginia the Primal series in the 

central counties of the State, or of the Great Valley, as follows:

(No. 1.) This rock or group of rocks, which is frequently exhibited in extensive 

exposures along the western side and base of the Blue Ridge, more especially in the 

middle counties of the valloy, is usually a compact, rather fine-grained, white or 

yellowish gray sandstone. Where resting on the declivity of the ridge it presents a 

gentle inclination to the northwest while the ^subjacent and more ancient strata of 

the ridge, in almost every instance, dip steeply to the southeast. In Page, Rockingham, Augusta, and Rockbridge counties this rock forms the irregular and broken 

ranges of hills lying immediately at the foot of the main Blue Ridge, and sometimes 

attaining an altitude little inferior to that of the principal mountain. A level region, 

sometimes of considerable breadth, and strewed profusely with the fragments of this 

rock, in general intervenes between these rugged hills and the first exposures of the 

valley limestone. * * * Talcose and micaceous matter make their appearance in 

it. * * * This micaceous and talcose variety is sometimes found in the same hill 

underlying the more purely silicious rock. The latter, in nearly all the exposures 

from the Balcony Falls to Thorn ton's Gap, as well as in various other places, exhibits 

vague, fucoidal and zoophytic impressions on the surfaces of bedding, together with 

innumerable markings at right angles to the stratification, penetrating in straight 

lines to great depths in the rock, and from their frequency and parallelism determining its cleavage in nearly vertical planes. These markings are of a flattened, 

cylindrical form, from one-eighth to one-tenth of an inch broad, giving the surface of 

the fractured rock a ribbed appearance, and resembling perforations made in sand 

which have been subsequently filled up without destroying the distinctness of the 

original impression. Precisely similar markings are found in great abundance in the 

white compact sandstone occurring at a higher point in the series, associated with 

numerous unequivocal impressions of fucoides.

The extent to which these sandstones are developed is comparatively inconsiderable in the southern and northern counties of the valley, and their structure and composition are in many respects materially changed.3

1 First Report of the State Agricultural Chemist of Maryland. Annapolis, 18150, pp. 34,35.

2Clomson, Thos. G.: Notice of a geological examination of the country between Frederickaburgh and 

Winchester, in Virginia, including the gold region. Geol. Soo. Penn., Trans., vol. 1,1835, map, oppo. 

p. 298.

3 Second report of the progress of the geological survey of the State of Virginia, for the year 1837. 

Richmond, 1833, p. 14.
134 THE CAMBRIAN. {BULL. 81.

The description of formation No. I in the third annual report is as 

follows:

The lowest of the 'Appalachian rocks consist for the most part of a close-grained 

white or light gray sandstone, in some places containing beds of a rather coarse conglomerate of white silicious pebbles. Near the bottom in many instances a brownish slaty sandstone occurs alternating with the former, while towards the top or 

approaching the next formation, the sandstone passes into reddish and brownish 

and olive-colored argillaceous slates.

This formation in Virginia is exclusively confined to the western slope of the 

Blue Ridge and the narrow belt of rugged hills and mountains extending thence to 

the commencement of the valley limestone. 1

In a paper on "The Lower Silurian brown hematite beds of America," 

Mr. B. S. Lyman states that all these beds seem to lie within the Virginia and Pennsylvania geological formation No. I, wholly below the 

Calciferous Sandrock of No. II.2

On the map accompanying the reprint of the annual reports and 

other papers on the geology of the Virginias, published in 1884, Prof. 

Eogers has included under one color, formations I to III or the Primal, 

Auroral and Matinal series. On the large series of sections, however, 

the three are differentiated and No. I or the Primal series is shown in 

sections 1 to 19, and also in 89.

Prof. W. M. Fontaine has added many details to the section of the 

Primal series described by Prof. Eogers, at Balcony Falls in Eockbridge 

County. The sketch of the Balcony Falls section3 is supplemented by 

that of Eockfish Gap and Harper's Ferry. »

For a further notice of the results of Prof. Fontaine's work the reader 

is referred to the description of the Cambrian rocks of Virginia.

In a note upon the Potsdam or Primal group of Virginia, prepared for 

Macfarlaue's American Geological Eailway Guide, Prof. W. B. Eogers 

puts as equivalent formations No. I of the Pennsylvania and Virginia 

surveys or Primal of the annual reports and Potsdam group. The 

latter is used in the nomenclature of the rocks of Virginia and West 

Virginia. In the note explaining the Potsdam group, he says:

The Potsdam, or Primal group, includes in Virginia, where complete, besides the 

Potsdam proper, the ferriferous shales next above, and the slates, shaly grits, and conglomerates, below this formation. It is exposed in varying mass and completeness 

on the western slope and in the west flanking hills of the Blue Ridge throughout 

much of its length, often, by inversion, dipping to the southeast, in seeming conformity beneath the older rocks of the Blue Ridge, but often, also resting uucontbrmably upon or against them. These older rocks, comprising masses referable probably 

to Huronian and Laurentian age, include also a group of highly altered beds, corresponding apparently to the copper-bearing or Keweenian series of northern Michigan, 

and perhaps to the lately described Dirnetian rocks of Wales. 4

'Report of the progress of tbe geological survey of Virginia, for 1838 (Richmond, 1839), p.G. Areprint of the annual reports and other papers, on the geology of the Virginias. New York, 1884, 

pp. 197,198.

2 On the Lower Silurian brown hematite beds of America. Am. Assoc., Proc., vol. 16,1867, p. 114.

3 On the primordial strata of Virginia. Am. Jour. Sci., 3d ser., vol. 9,1875, pp, 3G3-369.

4 Rogers, W. B. Virginia and West Virginia. [Geological formations.] Macfarlane's Am. Geol. 

K. R. Guide, 1879, p. 181.
WAT,COTT.) VIRGINIA. 135

Ifc will be noticed that Prof. Rogers adopts the same reference for the 

ferriferous or iron-bearing slates and shales that his brother did for the 

supposed equivalent formation in Pennsylvania.

Prof. J. L. Campbell published two papers in 1879,1 in which the 

Primal series of Prof. Eogers is described. These were followed in 1880 

by a revised description of the Silurian formation in central Virginia.2 

His observations will be noticed in the section on the Cambrian rocks 

of Virginia. In another paper he gives a definition of the " Primordial" 

as follows:

The Primordial. The great bed of ferriferous shales and sandstones skirting the 

western base ot the Blue Ridge from Tennessee to the Potomac; in the upper part of 

formation No. I of Prof. Rogers's Appalachian series.3

The most complete and detailed description of the formations referred to the Primal series of Eogers is that of Prof. W. M. Foutaine, 

published in 1S83.4 The section is formed of conglomerate at the base, 

subjacent to shales, upon which the so-caljed Potsdam quartzite rests. 

The upper member of the Primal series is the ferriferous shales. The 

entire thickness of this section is given as 2,380 feet, and the data 

given by Prof. Fontaf ue will be used largely in the summing up of our 

knowledge of the Primal series in Virginia. The reader is referred to 

that section for further details.

In an article upon the iron ores of the valley of Virginia, Mr. Andrew 

McCreath divides the u Primal or Potsdam sandstone" (Primal or Potsdarm formation) into (1) lower slates, (2) sandstone, (3) upper slate.

First. In the lower slates, or those geologically underneath the Potsdam sandstone 

occurs a red hemitite ore, sometimes in beds of considerable thickness and of good 

quality. This is the so-called "specular ore" of the Bine Ridge, and it has been quite 

extensively developed at numerous points, notably in Bototourt and Bedford Counties. * * * Second. In the Potsdam sandstone itself, important beds of iron-ore 

have been observed. The ore is generally a close-grained, brittle, dark brown hematite, invariably cold-short. In Rockbridge County a bed of it fully ten feet thick is 

exposed for a considerable distance on the Vesuvius property. * * * Third. The 

upper slates, however, are by far the most important from an economical standpoint, 

forming, as they do, one of the richest repositories of brown hematite iron ore in 

Virginia. They intervene between the Potsdam sandstone and the base of the calciferous limestone, and they are found all along the western slope of the Blue Ridge 

being geologically coextensive with it. They are generally more or lessdisintegrated, 

or decomposed into variegated clays; and while they may not always carry a continuous ore bed, yet, wherever the formation exists, deposits of iron, ore of greater or 

less extent may be confidently looked for. 6

1 Silurian formation in. central Virginia. Am. Jour. Sci., 3d ser., vol. 18,1879, pp. 16-29. Geology of 

Virginia; Balcony Falls; The Blue Kidge and it8 geological connections. Some theoretical considerations. Ibid., pp. 435-445.

2 The Silurian formation in central Virginia (revised). Tho Virginias, vol. 1, 1880, pp. 41-45,54-56.

3 Tho mineral resources and advantages of the country .adjacent to the James river and Kanawha 

Canal and the liuchanan and Clifton Forge Kail way. Tho Virginias, vol. 1, 1880, p. 3.

4 NoteH on the mineral deposits at certain localities oil the western part of the Blue Ridge. The 

Virginias, vol. 4,1883, pp. 21, 22,42-44. 

B The iron ores of the valley of Virginia. Am. Inst. Mining, 13ng., Trans., vol. 12,1884, pp. 18-20.
136 THE CAMBRIAN. [BULL.81.

In the sheet of sections accompanying "The Virginias" by Prof. William B. Eogers, printed in 1884, section 9 crosses the Primal series of 

Eockbridge County, about 30 miles north of Balcony Falls. On the 

eastern slope of the Blue Eidge a small synclinal basin of the Primal 

series is represented as resting in a hollow in the gneiss; on the western 

slope, the Primary series is shown as it occurs in numerous sections 

crossing the Great Valley and the Blue Eidge. The editor of the sections, Mr. Jed. Hotchkiss, states in the note accompanying them that the 

sections are "exact reproductions, in so far as the geology is concerned, 

of the sections as Prof. Eogers left them." From this it is evident that 

Prof. Eogers became aware of the presence of the Primal series on the 

upper eastern slope of the Blue Eidge in Eockbridge County after the 

publication of the third annual report in 1839, as he stated then that 

the Primal rocks were confined to the western side of the ridge.

Messrs. J. L. and H. D. Campbell, while studying the geological relations of the Snowdon slate quarries in Amherst County, on the borders 

of the counties of Eockbridge and Bedford, discovered the presence of 

the Balcony Falls series of Cambrian rocks and found that the quartzite 

passed beneath the slate of the quarries.1 On the map accompanying 

the paper (p. 170), an ideal section shows the shales and conglomerates 

resting on the gneiss beneath the sandstone, which they have referred 

to the Potsdam owing to its carrying Scolithua borings, and above the 

latter is the slate belt, in which the quarries are located. Under the 

title of u Geology of the Blue Eidge near Balcony Falls, Virginia; a 

modified view," Prof. Campbell corrects the statement made in a former 

paper, in the American Journal of Science in 1879, that the rocks of the 

southeast slope are of Archean age. He adds a sentence as follows:

We may conclude, therefore, that this portion of the Blue Ridge has heen formerly 

spanned by A grand arch, or series of arches, of Camhrian age, upturned perhaps at 

the time of their upheaval the broken fragments of which have been carried away, 

and only the abutments left to tell the story of a great catastrophe.2

In a letter on relation of Archean and associated formations in Virginia, Prof. W. M. Fontaine states that he finds in Virginia a valuable 

guide to the true base of the Potsdam in the conglomerates.

The lowest conglomerate is not always seen. It is often very coarse, with pebbles 

sometimes 4 to 5 inches in diameter, and composed of Laurentian or Hurouiau material, according to the nature of the underlying rock. The matrix is often shaly or 

slaty.

It is the conglomerates overlying this stratum that afford the best guide, for they 

may always be seen.

They are simply pebble beds in the slate or shale. The pebbles are from the size 

of a musket bullet down, and usually of quartz, often pink in color. The pebbles 

look as if they had been scattered over a muddy bottom, forming a very peculiar 

conglomerate in which all the material except the pebbles is a fine slate or shale. 

Sometime* some partially decayed feldspathic matter occurs with the pebbles.

1 The Snowdon slate quarries. The Virginias, vol. 5,1884, pp. 102,163.

*Geology of the Blue Ridge near Balcony Falls, Virginia; a modified view. Am. Jour. Sci., 3d ser., 

1884, vol. 28, pp. 222,223.
WALCOTT.J VIRGINIA. 137

These slialy conglomerates, as we may call them,' might sometimes be mistaken for 

certain amyydaloids of the Huronian when the latter are weathered, but careful examination will always detect the difference. I have never seen auy ahaly conglomerate in the Huronian.

I am now of the opinion that the conglomerates at the railroad bridge at Harper's 

Ferry are these lower Potsdam strata, but would require a reexamination of them 

before I make up my mind positively. I am also inclined to think that Frazer's 

Mountain Creek conglomerate is the same. 1

During the year 1885 Prof. H. D. Campbell published a more detailed 

account of the discovery of the Potsdam group east of the Blue Kidge. 

A resume" of the section is given as it occurs on the north western slope 

of the Blue "Ridge at Balcony Falls for the purpose of comparing the 

rocks as found upon the southeastern slope. On the eastern slope the 

strata lie in a basin of Archean rocks forming a synclinal, a section of 

which practically reduplicates the lower portion of a section of the 

" Potsdam group " of the western slope. A map and figure of the section accompany the paper.2 In a second article in connection with his 

father, the Cambrian-Primordial (No. 1 of Rogers) is described in considerable detail,3 and mention is made of the discovery of another area 

referred to the " Potsdam group " on the eastern slope of the Blue 

Bidge, at Tye Eiver gap, in Kelson County.

Prof. J. J. Stevenson identifies the Cambrian rocks, crossing Montgomery, Pulaski, and Wythe Counties, as the Lower Knox shales and 

the Potsdam of the Tennessee section. Under the title " Cambrian " 

he says:

Here aro^ placed the Lower Knox shales and. the Potsdam. The former are probably equivalent to the Hydromica schists of Pennsylvania and the lower part of the 

Calciferous of New York; the latter is the Potsdam of New York, vastly increased in 

thickness.

No fossils were observed in the Kuox or the Potsdam shale with the 

exception of Scolithus lincaris. The geographic distribution of the formations referred to the Cambrian is shown on a map accompanying 

the paper. Further reference will be made to Prof. Stevenson's paper 

in describing the Cambrian rocks of Virginia.4

In a paper read before the Geological Society of America December 

31,1890, by Messrs. H. E. Geiger and Arthur Keith, it is stated that 

the shales and quartzite at Harper's Ferry represent the Hudson and 

Medina series and not the Primal series as stated by Profs. Eogers and 

Fontaine. They present a number of sections showing the stratigraphtc 

position of the beds. In these the normal succession is limestone, 

shales, and sandstone. The shales succeed the limestones, and overlap

1 (Letter on relations of Arcliean and associated formations in Virginia.) G-eol. Chester Co., Pa., 

2d Gool. Surv., C4, 3883, p. XV.

2 The Potsdam group east of the Blue Ridge at Balcony Falls, Virginia. Am. Jour.Sci.,3d eer., 

vol. 29,1885, pp. 470-474.

3 Review of William B. Eogers's Geology of the Virginias. Ajn. Jour. Sci., 3d sor., vol. 30, 1885, pp. 

364-368.

4 A geological reconnaissance of Bland, Giles, Wythe, and portions of Pulaski and Montgomery 

Counties of Virginia. Am. Phil. Soc. Proo., vol. 24,1887, pp. 86-87.
138 THE CAMBRIAN. [BULL. 81.

upon the pre-Paleozoic rocks, the quartzite in turn resting upon the 

shales. This makes the limestones represent the Great Valley limestone of Virginia or the Calciferous-Chazy-Trenton belt; the shales, the 

Hudson series, and the sandstone, the Medina series of the New York 

section.1

iNORTH CAROLINA.

As now known the Cambrian rocks of North Carolina are confined to 

the extreme western boundary, where the Ocoee conglomerate and 

Chilhowee sandstone series extend across from Tennessee. This was 

recognized by Prof. J. M. Safford in his work in Tennessee; and Prof. 

W. C. Kerr notes the occurrence of thin-bedded, siliceous slates at Paint 

Eock, on the State line. He says of them:

They are called by Prof. Safford, the geologist of the State of Tennessee, Chilhowee sandstones, and are set down conjectnrally by several eminent geologists as 

Potsdam sandstone. They have never yielded any fossils by which their geological 

horizon might be determined. A few very thin beds of argillaceous slate are found 

interpolated here and there between the quartzose strata.

Passing up the deep gorge which the river has excavated, the quartzites are soon 

found to be interbedded with and are finally replaced by shales and grits, the latter 

generally fine, but occasionally approaching in appearance a breccia or conglomerate. 

These are succeeded by heavy beds of argillaceous slates and shales, which in turn 

give place, at Warm Springs, to a heavy bedded blue and gray limestone. This is 

followed by a calcareous, compact, fine-grained sandstone, which presently passes 

into a gray, much jointed quartzite rising in vertical cliffs along the river for 2 miles, 

and succeeded by a well characterized coarse conglomerate with bluish gray slates 

and shales, at and below the mouth of Laurel River. A little above this point cornea 

in a very extensive and conspicuous bed of feldspathic quartzite, or petrosilex, which 

continues for more than a mile, and then graduates through a gneissoid rock into a 

series of gray, drab, and mottled argillaceous slates and shales. This succession of 

quartzites, grits, shale, limestone, and conglomerate occupies in direct cross section 

a space of more than 10 miles. I have elsewhere referred to the identity of this formation with that which is so conspicuous on Valley River, and shall therefore call it 

the Cherolcee Slates. They pass in a northeast course np the Laurel Valley and 

through the Smoky or Unaka Mountains into Tennessee.2 ,

In a note on the occurrence of metamorphic Silurian rocks in North 

Carolina, Prof. F. H. Bradley states that the rocks about Franklin are 

of Lower Silurian age, and the marbles of Murphy and vicinity are the 

equivalents of the Knox limestones of Tennessee, which are of Quebec 

group age.3 This statement of Prof. Bradley's is noted here, as it is 

probable that the formations examined by him are equivalent to those 

exposed on the French Broad, between Warm Springs, North Carolina, 

and Paint Rock. If so, they may be of Cambrian age. In a paper published the following year, Prof. Bradley refers4 to the strata in the 

vicinity of Murphy, in southwestern North Carolina, and takes the view

1 Bull. Geol. Soc. America, vol. 2,1891, pp. 155-163.

2 lloport of the State Geologist of North Carolina. Raleigh, 18G9, p. 29.

3 Note 011 the occurrence of inelantorphic Silurian rocks in North Carolina. Am. Jour. Sci., 3d ser., 

vol. 8,1874, p. 390.

4 On the Silurian age of the southern Appalachians. Am. Jour. Sci., 3d ser., vol. 9,1875, pp. 286,382.
WALCOTT.] TENNESSEE.

already mentioned. There is, however, more or less of uncertainty 

in relation to the identification of the rocks about Murphy and on the 

line of the Hiwassee Biver; so much so that outside of the recognized 

Cliilhowee strata I think it would be very hazardous to state that the 

Cambrian is represented in southwestern North Carolina. In his description of the stratified rocks, Prof. Kerr states that so far as known 

the Primordial is represented only in its lowest member, where it crosses 

the northwest border in. a few points along the Smoky Mountain.1 A 

description of the section upon the French Broad, from Paint Rock to 

Warm Springs, is reprinted by him (pp. 138, 130), with the statement 

that Prof. Saiford makes the Paint Bock sandstone.^ to be Cliilhowee 

or Potsdam; the grits and conglomerates below and above Warm 

Springs to be Ocoee or sub-Potsdam; while the limestone is referred 

to the Knox Dolomite, which is above the Potsdam.2 He also gives 

Prof. Bradley's identification of the rocks that belong to Cherokee 

County in the southwestern portion of the State.

TENNESSEE.

The classification adopted by Dr. Gerard Troost, in his fourth report 

as geologist of the State of Tennessee, is as follows : 3

1. Primordial, or Primitive, or Crystalline.

2. Transition or Fragmentary. 

3» Secondary or Sedimentary. 

4. Tertiary or Upper Secondary, 

In mentioning this classification he says:

I should have confined myself to the two first parts of this division, the Primordial 

and Transition series, as they constitute the greatest part of the district that I have 

examined.

This nomenclature is used in the fifth annual report, where he states 

that the Crystalline Primordial rocks form the highest part of the 

Appalachian Chain. The line of contact of the Primordial rocks with 

the Transition or Fragmentary coincides in a general way, but not 

exactly with the boundary line between Tennessee and North Carolina.

The country lying between the Great Smoky Mountains and the Cumberland 

Mountains, or East Tennessee, is for the most part composed of strata of granwacke, 

sandstone, and limestone alternating with each other, and in which organic remains 

are rarely found; these strata are highly inclined, approaching in some places 

towards the vertical, dipping more or less towards southeast and running nearly 

parallel with the Smoky Mountain ridge; they are covered in several places by 

horizontal strata of limestone of a dark gray, approaching to a black color, and having a granular structure. It is in some places characterized by Macluritea, Le Suour, 

Conotubularia, nobis, Isotellus, Dekay, and several species of Calamopora, Goldf. *

On the map and sections accompanying the report the Primordial or 

Crystalline series is colored blue, and the Secondary or Grauwacke

1 Report of the geological survey of North Carolina, vol. 1,1875, p. 115. Kaleigh.

2 Op. cit., p. 140.

8 Fourth report of the geologist of the State ot Tennessee. Nashville, 1838, p. 630.

4 Fifth geological report on the State of Tennessee. Nashville, 1840, p. 5.
140 THE CAMBRIAN. . [BULL.81.

series, composed of grauwacke, slaty grauwacke, sandstone, and limestone, which extend from the Primordial series to where they are lost 

under the Cumberland Mountains, is colored yellow, thus roughly outlining the relations of the Cambrian and pre-Cambrian rocks of eastern Tennessee.

Before publishing the Sixth Annual Report, Dr. Troost read Murchison's " Siluria," and also the observations of Prof. Sedgwick on the 

Cambrian rocks of Wales. In discussing .the changes of nomenclature 

made necessary in accepting the views of Messrs. Murchison and 

Sedgwick, he says:

After having»pointed out, in my last report, the line of junction of the Primordial 

or crystalline rocks in East Tennessee, I mentioned that the country west of the liue, 

which separates Tennessee from the State of North Carolina, is composed of granwacke, slate, limestone, etc. All this country, according to the views of Mnrchison 

and Sedgwick, belongs to a new division, which they call the Cambrian system.

This series of strata contains few organic remains; in fact, I have carefully examined, in this respect, the Tennessee strata and have never discovered any in them. 1

In his attempt to identify the Cambrian and Siluriansy stems in 

Tennessee, he included rocks in the Cambrian system that, under the 

original definition of Sedgwick for that system in Wales, is surprisingly 

correct. In describing the geographic distribution of the Cambrian 

system, he says:

I consider the termination of the Cambrian System towards the west. This system 

commences, as already observed, about the line which separates the State of Tennessee from North Carolina; and, as mentioned in my preceding reports, is also, with 

a few exceptions, the line of separation between the transition and primordial strata. 

It runs sometimes a few miles into North Carolina; sometimes penetrates, for a few 

miles, into Tennessee, forming the great Unica or Smoky Mountain, Bald Mountain, 

and Iron Mountains; but the culminating ridge of this mountain chain is mostly 

composed of the Cambrian rocks, while south of it the crystalline or Primordial rocks 

are found.

Leaving this ridge in a north, or rather northwest direction, we have a series of 

slaty rocks, containing here and there chlorite, passing into talcose slate or into 

quartzite. This series seems to be equivalent to Sedgwick's Lower Cambrian series; 

some extensive strata, mostly of brown or reddish brown, fine grained limestone 

occur occasionally in this series; such a stratum is seen about 5 miles west from 

the Primordial rocks, crossing, near the Warm Springs in Buncombe County, the 

French Broad River. We have then a series of strata of slates and sandstone, and 

about 4 or 5 miles west of Newport a limestone stratum appears again, extending 

through Cocke and Sevier counties, parallel to the above-mentioned high chain. I 

suppose the Lower Cambrian system terminates there.

Upon the Lower Cambrian rocks follows another series. It is composed of roofing 

slate, glossy aluminous slate, and sandstone. A ridge of fine roofing slate crosses 

Sevier County. I believe that this series commences with Star's, Tellico, and Chilhowee Mountains in McMinn, Monroe, and Blount counties, ranging parallel with the 

great Smoky Mountain, extending in a southeastern direction through Sevier County. 

I have not been able to trace it further to the northeast. This series seems to be 

equivalent to the Middle Cambrian. * *

I consider, as stated above, that Bay's Mountain forms the upper part of the Cambrian system or, that it perhaps belongs to the Old Red sandstone that hence towards

 Sixth annual report of the geological survey of Tennessee, by the State geologist. Nashville, 

841, p. 4.
WALCOTT.1 TENNESSEE. 141

the north of that mountain chain another formation commences, which is the Silurian 

system of Murchisou, and extends northward as far as the line which separates this 

State from Virginia in fact, it continues into that State.1

In his description of Sevier County the roofing slate and other slaty 

rocks and the non-fossiliferous limestones are referred to the Cambrian 

group.2

Dr. Troost identified the Cambrian group in Tennessee with that of 

Wales entirely upon the lithologic characters and the absence of organic 

remains; and upon the fact that it was succeeded by a Series of limestones from which he obtained and identified Silurian fossils. Although, 

in the light of our present knowledge, there were many inaccuracies in 

this correlation it exhibits a comprehensive grasp of the views expressed by Messrs. Murchison and Sedgwick and unusual clearness in 

the correlation of the groups of rocks in the two countries.

In a sketch of the general geology of the Hiwassee copper region 

Prof. J. P. Lesley describes the primary region of the Hiwassee and 

Ocoee Rivers as a southern prolongation of the metamorphic rocks 

of the Blue Ridge, South Mountain, and Highlands of the Middle and 

Northern States.

It greatly resembles in every important geological particular the range of the White 

Hills in New Hampshire. * * * * They are not primary rocks, granites or porphyry, but the Primal and Matinal sandstones, shales, and limestones and conglomerates at the base of the older secondary series, baked, crystallized and upturned in 

collapsed synclinal and anticlinal axes.

He describes the section on the line of the Ocoee Eiver as formed of 

slightly metamorphosed conglomerate strata.

In places these rocks are a simple pea conglomerate, quartzose, and interstratified 

with the hardest homogeneous blue and gray grits and scarcely altered.3

The preceding correlation was based upon the view that the strata 

now referred to the pre-Cambrian Algonkian series were metamorphosed Primal and Matinal rocks, corresponding in age to the unaltered Primal and Matinal rocks to the westward. That they might 

form a great group of strata beneath the Primal and superjacent to the 

Primary proper, or Archean, was not at the time entertained by the 

writer. «

In 1856 Prof. J. M. Safford published his first report of "A Geological 

Reconnaissance of the State of Tennessee," in which he classified the 

formations as follows :4

Formation I. The mica slate group.

II. The Ocoee conglomerates and slates.

III. The Chilhowee sandstones and shales.

IV. The Magnesian limestone and shale group.

1 Op. cit., pp! 5, 6. * Op. cit., p. 28.

8 First annual report of the board of directors of the Hiwassee Mining tJompany, made May 11,1853. 

New York, 1853, p. 16. 

4 A Geological Reconnaissance of Tennessee; first biennial report. Nashville, 1856, pp. 151-154.
142 . THE CAMBRIAN. [BULL. 81.

Formations III and IV were referred to the Cambrian system, and 

the formations above IV to the Silurian and Devonian systems, etc.

The term Cambrian was used provisionally to unite the first two fossil-bearing formations. The upper portion of formation No. IV, or the 

limestone member, was subsequently, in 1869, referred to the Knox 

dolomite.

This preliminary report was followed in 1869 by the volume on 

" Geology of Tennessee," in which all the strata now referred to the 

Cambrian are described in detail. 1 A map illustrating the geographic 

distribution of the formations in the State, and a transverse section 

from the North Carolina line west, showing the stratigraphic relations 

of the formations, accompanies the volume.

In speaking of the age of the inetamorphic rocks of eastern Tennessee, which have been referred to by various authors as altered Silurian 

rocks, Prof. Safford says :

I have no reason for believing that this group within Tennessee includes the 

metamorphosed beds of any formation of more recent date than the Ocoee conglomerate and slates. A portion of the beds are certainly referable to the Ocoee group; 

the remainder, although conformable, may be older, and most likely are. * * * 

In the northern part of the State, at many points, the passage of the Ocoee beds into 

gneiss is gradual and apparent. A considerable part, indeed, of our inetaiuorphic 

rocks can be, I think, thus referred to these beds. The question as to the greater ago 

of other parts is not so easily settled, and must remain open for the present. I know 

of no sufficient reason for referring any of these rocks to the Hurouian or Laurentian 

series of Canada. 3

It will thus be seen that the line of demarcation between the preCambrian rocks and the Cambrian rocks has not been closely defined 

in Tennessee. It is only by compari son with the more clearly defined 

line found in the sections of the Blue Eidge in Virginia that we are led 

to consider that the metamorphosed rocks belong to an Algonkian 

group between the Cambrian and the Archean. The studies which are 

now in progress under the direction of the Geological Survey clearly 

demonstrate this, and give as the base of the Cambrian a series of sandstones. Where the sandstones and conglomerates are made up of the 

material derived from the adjacent Algonkian or Archean rocks they 

will necessarily have something of the character of those rocks, and it 

may be difficult in many instances to indicate the actual line of demarcation, especially where the basal beds have been more or less altered 

and disturbed by the subsequent folding, faulting, and compression 

that accompanied the Appalachian uplift.

As defined by Safford. Series II, or the Potsdam group of Tennessee, 

consists of 

1. The Ocoee conglomerate and slates.

2. The Chilhowee sandstone.

3. The Knox group of shales, dolomites, and limestones.

'Geology of Tennessee. Nashville, 1869, pp. 182-220. 2 Op. oit., pp. 177,178.
WALCOTT.] TENNESSEE. 143

As known to me at the present time the dolomites and limestone are 

referred to the Lower Silurian, as the equivalent of the Calciferous and 

Chazy zones of the New York section. This refers the Knox shale to 

the Upper Cambrian. Prof. Safford states that it is not easy to separate 

lithologically the Ocoee sub-group from the Ghilhowee, as they often run 

into each other. The distinction between the latter and the Knox is 

much more apparent.1

The Ocoee Conglomerate. The typical section of the Ocoee conglomerate in the gorge of the Ocoee Eiver, is described by Prdf. Safford as 

follows:

The strata are well displayed. They are, in general, coarse gray conglomerates, 

talcose, chlorite and clay slates repeatedly iutorstratified, all having a semi-inetamorphic aspect. The slates predominate, and of these, the greenish and light bluish gray, 

or the chloritic and talcoso varieties, are tlie most abundant. * * The middle 

part of tlie section presents little conglomerate, but in the upper part it abounds.

* * * The lower part of the gorge has several bands of conglomerate. 2

The thickness of the Ocoee formation was not determined. Provisionally it was estimated to be more than 1.0,000 feet (p. 186), As shown 

on the map, the main portion of the Ocoee conglomerate occurs south of 

Nolichucky Eiver. In Johnson County, in the extreme northeastern corner of the State, it occurs as a narrow band next to the metamorphic 

series. South of the French Broad River, it occupies a wide belt to the 

Georgia line. Prof. Safford says it is truly a mountain-making formation.

The recent work of the U. S. Geological Survey has shown that the 

Ocoee conglomerate is of Silurian age, and it is not to be included with 

the Cambrian.

The description of the Chilhowee sandstone, and Knox shales and 

sandstone, will be given in the summary of the present knowledge of 

the Cambrian rocks of Tennessee.

A re'sume' of the geology is given in a report upon the resources of 

Tennessee, by Mr. J. B. Killebrew,3 which was prepared by Prof. Safford. It is a brief restatement of the character of the formations as 

described in the " Geology of Tennessee," and the geological map accompanying it is based upon that published in 1869.

When discussing the Silurian age of the Southern Appalachians, Prof. 

F. JET. Bradley considered that the Knox group, of Safford, included the 

Quebec group and the Calciferous; the Chilhowee sandstone represented the typical Potsdam; and the Ocoee the Lower Potsdam or Acadian group. He also thought that the rocks of North Carolina, south 

and west of the Little Tennessee, together with the metamorphic area 

of Georgia, north of a line parallel with and 10 miles south of the Chattahoochee (and probably that south of this line), and the entire metamorphic area of Alabama, are Silurian or newer, with, the possible excep-

»Op. cit., p. 182. «Op. cit., p. 184.

8 Resources of Tennessee. Nashville, 1874, pp.26-46.
144 THE CAMBRIAN. [BULL. 81.

tion of two or three small patches not over 10 miles in diameter. 1 A 

description of sections from Athens and Knoxville, Tennessee, to Murphy, North Carolina, accompany the paper.

The descriptive notes and conclusions of Prof. Bradley were followed, 

in 1883, by the expression of a somewhat similar view of the age of the 

Southern Appalachians by Mr. J. B. Elliott,2 in which he concluded with 

Bradley that the metamorphosed strata east of the unaltered Ocoee and 

other " Lower Silurian" rocks were formed of metamorphosed strata of 

the Knox section.

In the table of formations accompanying Macfarlane's American 

Geological Eailway Guide, Prof. J. M. Safford arranges the formations 

now referred to the Cambrian in the following descending order: 

3&. Knox shale. 

3a. Knox sandstone. 

2&. Chilhowee sandstone. 

2a. Ocoee group. *

He places as equivalent formations, following Dana's Manual, the 

Ocoee and the Acadian; the Chilhowee and the Potsdam; the Knox 

sandstone and the Calciferous; and the Knox shale and the Quebec. 

This is the classification suggested by Bradley.3 The Metamorphic 

group, No. 1, beneath the Ocoee group, is correlated with the Archean.

In an attempt to assign to the proper stratigraphic horizon the rocks 

referred to the Cambrian group in the United States and Canada, Mr. 

C. D. Walcott correlated the Kuox shale and sandstone with the Potsdam sandstone. The supposed subjacent Chilhowee sandstone and 

Ocoee conglomerate were referred to a position corresponding to the 

horizons of the Olenellus and Paradoxides faunas.4 Subsequently, 

references to the two formations were omitted, pending an investigation of their true stratigraphic position. The discovery, in 1889, of the 

Olenellus fauna in the shales resting conformably in the Chilhowee 

series, thus verifying Prof. Safford's section, affirms the correlations 

of 1883, except that it carries the Middle Cambrian zone above the 

Chilhowee sandstone and drops the Ocoee, if it proves to be beneath 

the Chilhowee quartzite, back into the Basal Cambrian.

GEORGIA.

Of the Transition, or older fossiliferous rock formation, Mr. George 

White said, in 1849, that it has been less explored than any other part 

of the geology of Georgia.

That part of it which extends from the western hase of the primary rocks to the 

Chattoogatta range of mountains, and which forms the valley of the Oostanaula

1 On the Silurian age of the Southern Appalachians. Am. Jour. Scl., 3d ser., vol. 9,1875, pp. 279,280.

2 The age of the Southern Appalachians. Am. Jour. Sci., 3(1 ser., vol. 25,1883, pp. 282-298.

3 Tennessee. (Geological formations.) Macfarlane's Am. Geol. R. E. Guide, 1879, p. 196.

4 The Cambrian System in the United States and Canada. "Washington Phil. Soc., Bull,, vol. G, 1883, 

p. 100. Second contribution to thfj studies of the Cambrian faunas of North America. TJ. S. Geol. Survey, Bull. No. 30,1886, p. 63,
WAUJOTT.J GEORGIA. 145

River, belongs probably to the older series of the New York formations, as those portions which have been examined contain Potsdam sandstones, Calciferous sandrock 

and limestones of the Trenton group. Very few fossils have been found in it. 1

This brief description is accompanied by a map, upon which the transition or oldest fossiliferous formations are indicated by one color, in 

the northwestern corner of the State.

As in the case of North Carolina and Alabama, a long interval elapsed 

between the first geological survey and the renewal after the conclusion of the civil war. In 1876 Mr. George Little published an account 

of the geological formations in Georgia, to accompany Janes's HandBook of the State. He divides the Lower Silurian into two periods.

The hydro mica schists of the copper-bearing series of the Mobile mine and Ducktown, and Ocoee conglomerates and slates along the Ocoee River on the Tennessee 

line, and on the Etowah River, near Cartersville, are the lowest in position of the 

rocks in the State, and form a group of (2) Primordial rocks corresponding to what 

is called the (2a) Acadian epoch in Canada. The conglomerate is made up of feldspar and a bluish quartz. The slates are hard and siliceous. This group of rocks is 

overlaid in the Cohutta Mountains, and on Pine Log Mountain in Bartow County, 

by a sandstone called the Chilhowee, from a mountain of that name in Tennessee, 

corresponding to the Potsdam sandstone in New York, * * * and belongs 

also to the (2) Primordial period and to the (2ft) Potsdam epoch. This sandstone 

appears in the north of Haralson and Paulding counties, and in Yonah Mountaiu, 

White County, and Tallulah Mountain, Habersham County, being at all these places 

altered into gneiss by metamorphism.

The next period, called (3) Canadian, embracing the (a) Caloiferous * * * of New 

York, * * * the (&) (Juebec epoch in Canada, and the (c) Chazy limestone of New 

York, is represented by impure sandstones and cherty dolomitic limestones in the northwestern counties; by a sandstone on the western slope of the Cohutta Mountains; and 

in the metamorphic region to the eastward and southward by calcareous schists, hydromica schists, marble, and itacolumite of the Quebec epoch, and by calcareous schists 

of the (a) Calciferous epoch.2

 , __

This arrangement follows that of Prof. Safford in Tennessee except 

that the Knox sandstone and the Knox shales are not included.

In a work on " The Commonwealth of Georgia," prepared under the 

direction of J. T. Henderson3 in 1885, there is a general description of 

the geology of the State. The Acadian or the Ocoee and Chilhowee 

formations and the Kuox shales are all recognized. Eeference to this 

description will be made in the summary of our present knowledge of 

the Cambrian rocks of Georgia.

In the Tenth Census report a brief re'sume' of the geology is given 

with relation to the soils formed from their decomposition. In this Mr. 

A. K. McCutcheu states that the aggregate thickness of the groups, 

estimating the Primordial at 8,000 feet, and taking the maximum thickness of each of the higher groups, amounts to about 20,000 feet. The 

Primordial and Calciferous are followed by rocks referred to the Quebec

1 Statistics of the Stute of Georgia. Savannah, 1849, p. 22.

2 Little, George. Geological survey of the State of Georgia. Hand-book of the State of Georgia, 

with geologic mnp of State, by T. P. Janes, 1876, p. 37.

'Geology (of Georgia). The Commonwealth of Georgia, The country); the people; the produc* 

#OD8. Atlanta, 1885, pp. 73-117.
146 THE CAMBRIAN. [BULL. 81.

group; first by about 2,400 feet of shales, and then by 5,000 feet of 

cherty limestones1 . Combining these estimates we have 8,000 feet of 

Primordial and 2,400 feet of shales corresponding in position to the 

Knox shales, which gives a total of 10,400 feet for the Cambrian rocks 

of Georgia, as estimated. This paper is accompanied by a section 

crossing Bade, Walker, and Gordon Counties in northwestern Georgia. 

The stratigraphic relations of the Cambrian rocks are shown as they 

occur in Gordon County.

A geological section of the Cambrian rocks of northwestern Georgia 

has recently been published by Mr. 0. Willard Hayes of the U. S. 

Geological Survey. It is referred to in the description of the Cambrian 

rocks of Georgia.2

ALABAMA.

The report of Prof. M. Tuomey for 1858 3 contains a very general 

description of the formations of the State, and on the accompanying 

inap*the Silurian and Devonian formations are included under one 

color, so that it is impossible to differentiate that portion of the Silurian formation which has subsequently been found to belong to the 

Cambrian group. In a general north and south section, showing the 

disposition of the strata, the Silurian and Devonian rocks are represented as unconformably subjacent to the Coal Measures and mountain 

limestone.

A long interval elapsed between the work of Prof. Tuomey and the 

organization of the geological survey under Prof. Eugene A. Smith. 

In the report of progress of the latter, for the year 1875, a general 

description of the geological formations of Bibb, Shelby, Talladega, 

and Calhouu Counties is given. In this area there is a targe development of metamorphic rocks described by Prof. Smith in the report for 

1874.4 Of this series he says:

On the southeastern border of the Silurian formation in Alabama, from the Georgia 

line to the northeast corner of Chilton County, a stratum of crystalline liinestonej 

almost pure carbonate of lime, maybe traced by its occasional exposures. * » » 

Succeeding this limestone and apparently overlying it conformably * * * is a 

series of semi-metamorphic strata between 15,000 and 20,000 feet in thickness, striking northeast and southwest and dipping at high angles (45°) southeast. This series, 

beginning below, is composed of greenish gray hydro-mica slates (talcoid slates, nacreous argillites, talcose slates), passing upwards into a conglomerate by enclosing 

lumps of quartz; these slates are succeeded by thick beds of quartzite, alternating 

with greenish chloritic schists. The quartzite in places is a thin-bedded silicious 

slate, again a thick-bedded quartzose conglomerate, and still again a laminated 

quartzose or arenaceous rock, not very coherent, and enclosing small grains of quartz,

1 Northwest Georgia. (Geologic description.) Tenth Census U. S., vol. 6; Report on Cotton Production in the United States, Part 2, 1884, p. 287.

2 The overthrust faults of the southern Appalachians. Bull. Geol. Soo. America. Vol. 2, Feb., 1891, 

p. 143, pi. 3-

1 Seoondbiennial report on the geology of Alabama. Montgomery, 1858, pp. 168.

'Geological survey of Alabama. Report of progress for 1874' Montgomery, Alabama, 1876, pp, 

21-25.
WALCOIT.] . ALABAMA. 147

This series of qnartzites in their several varieties makes up the main body of the 

Blue Mountains range in Alabama.

These strata are the probable equivalents in Alabama of the Ocoee conglomerates 

and slates of Prof. Safford, of the Tennessee survey, by him referred to the Silurian 

age underlying the Potsdam. By Prof. Sterry Hunt the entire system of crystalline 

schists has been referred to pre-Silurian and pre-Cambrian age. My own observations 

in the field while inclining me to the latter view, have not been sufficiently extended to 

enable me to form an independent judgment on this point. * * * Mr. F. H. 

Bradley refers to the Lower Silurian all the metamorphic rocks of North Carolina as 

far east as Franklin. 1

This in eta in orphic belt is apparently the same as the altered Silurian 

rocks of Prof. Bradley, as stated by Prof. Smith, and also of the altered 

rocks forming the northward extension of the Blue Kidge through Tennessee, Virginia, and Maryland into Pennsylvania, where it forms the 

South Mountain.

In the report for 1875 Prof. Smith states that he has followed the 

Tennessee subdivisions as found in Prof. Saijbrd's published volume.2 

Under the caption of "Lower Silurian," the Primordial or Cambrian 

period is divided into (1) Acadian epoch and (2) Potsdam epoch. The 

Acadian slates and conglomerates of Talladega County are considered 

to be the exact equivalents of Saffiord's Ocoee slates and conglomerates.3 The direct superposition of the sandstone referred to the Potsdam, upon the Acadian slates, is not well shown in Alabama. The 

formation consists of fine-grained conglomerate, heavy-bedded sandstone, and sandy shale. The most characteristic markings of the rocks 

of this formation are the sandy rods, caused by the filling in with sand 

of the burrows of a marine worm, iScolithis linearis.*

The Knox sandstone and Knox shales are referred to the Canadian 

period, thus following Prof. Safford's arrangement in Tennessee. The 

Knox sandstone is considered to rest upon the sandstone referred to 

the Potsdam, but no contact of the two formations in such a position is 

known to him. The sandstone is a calcareous sandstone associated with 

hard calcareous shales.

The Knox, shales are very similar to those of Tennessee, and succeed 

conformably the Knox sandstone. The line between the Knox shale 

and the Kuox dolomite is difficult to draw since the lower part of the 

dolomite contains beds of blue limestone similar to those in the upper 

part of the shale. This report contains much detailed information of 

the strata referred to the Cambrian in Alabama, and will be principally 

used in the description of the Cambrian rocks of that State.

In a paper on the iron ores of Alabama, with special reference to 

their geological relations, Prof. Smith states that the Potsdam sandstone frequently contains large amounts of iron, principally as limonite. 

In the Kahatchee hills, in Talladega County, the sandstone is sometimes impregnated with iron in the form of specular ore or as magnetite.

'Op. cit.,pp.21,22.

' " Report of progress of the geological survey of Alabama for 1875. Montgomery, 1876, pp. 7,8. 

. » Op. oit., p. 127. ^ « Op. oit., p. 14,
148 THE CAMBRIAN. [BULL.SL

Small beds of limonite are found in the Knox sandstone and Knox 

shales.1 In 1878 the same writer published an outline of the geology 

of Alabama accompanied by a map of the State, based upon that of 

Tuomey, published in 1858. Of the age of the metamorphic rocks he 

says that until further examination he leaves the question of age an 

open one, except in two instances, in which he believes at least a part 

of them are metamorphosed Silurian beds.2

The classification and general description of the formations is essentially the same as that contained in the reports of 1874-'75.

In a report on the physico-geographical and agricultural features of 

Alabama, Prof. Smith notes the character of soil produced by the rocks 

of the different formations, from the Potsdam to the Coal measures.3 

This paper was also printed in a general description of the State of 

Alabama, in voL 6, of the Tenth Census.4

A brief description of the Cambrian rocks of Alabama is given by 

Prof. Eugene A. Smith, in a report on the geological structure and description of the valley region adjacent to the Cahaba coal field.5 A 

summary of it is given in the description of the Cambrian rocks of 

Alabama.

Keferences are made to the geology of Alabama, in a general way, 

by Dr. T. S. Hunt, Prof. Smith, and various mining engineers, but I 

have not, with the exception of the preceding notice, met with original 

contributions to the knowledge of the Cambrian rocks, since the publication of Prof. Smith's detailed description.

PALEONTOLOGY. 

NORTHERN APPALACHIAN DISTRICT.

The first discovery of fossils in rocks, now referred to the Lower 

Cambrian, was made by Dr. Asa Fitch.6 In the summer of 1844 he 

found trilobites in a black slate in Washington County, New York, 

which was referred by Dr. B. Emmons to the Taconic slate or Argillite 

(1 of Eaton). Dr. Fitch sent the fossils to Dr. Emmons, who described 

from them two species of trilobites under the names of Atops trilineatus 

and Elliptocephalus asaphoides."11 Believing that the rocks in which the 

trilobites occurred were unconformably beneath the Potsdam sandstone,

1 Tho iron ores of Alabama, with special Reference to their geological relations. Am. Assoc. Proc., 

vol. 27,1878, pp. 247, 248.

2 Outline of the geology of Alabama. Berney's Hand-Book of Alabama, 1878, p. 140.

8 (Geological features and divisions of Alabama.) Q-eol. Survey of Alabama. Report for 1881 and 

1882,1883, pp. 178-181.; 192-210.

* General description of the State of Alabama. Tenth Census U. S., vol. 6. Report on cotton production iu the United States, part 2,1884, pp. 19-69.

6 Geological Survey of Alabama. Report on the Cahaba coal field, part li, 1890, pp. 148-150. (Issued 

January, 1891.)

6 A Historical, Topographical, and Agricultural Survey of the Coiltttyof Washington, Tl&H8i Ifi 3T» 

State Agric. Soc. for 1849,1850, p. 865.

'The Taconic System, based on observations in New York, Massachusetts. Vermont, and, Rhode 

Island, p. 20,21 Albany, 1844..
WALCOTT.J PALEONTOLOGY APPALACHIAN. 149

Dr. Emmons called them the oldest known fossils in America. In the 

same work Dr. Emmons described Fucoides rigida, F. jlexuosa, Gordia 

marina, Diplograptus simplex, and others of Silurian (Ordovician) age 

that he referred to the Taconic system.

The second description of fossils was made by Prof. James Hall in 

the Paleontology of New York, vol. 1,1847. Under the title " Description of fossils of the Hudson Eiver group," the following species were 

described as new: Orbicula ccelata (p. 290), Orbicula ? crassa (p. 290), 

Avicula ? desquamata (p. 292), Theca ? triangularis (p. 313), Metoptoma 9 

rugosa (p. 306), Palwophycus virgatus (p. 263), and Agnostus lobatus (p. 

258). A description and figures are given of Olenus asaphoides, Emmous, on pages 256, 257, pi. 67, tigs. 2a-e. In a later publication1 he 

identified Conocephalus and Olenus from the Eed Sandrock formation 

of High gate, Vermont, but did not assign them to a geologic horizon. 

In studying a collection sent to him by Eev. Zadock Thompson, Prof. 

Hall determined and described Olenus thompsoni, 0. vermontana, Pefaira 

(Olenus) holopyga, referring them to the Hudson Eiver group.2 He 

supported this reference by the statement that Sir William Logan referred the shales containing the fossils to the upper part of the Hudson 

Eiver group. In I8603 he proposed the genus Barrandia, to include 

Olenus thompsoni and 0. vermontana. The genus Bathynotus was established to include Olenus (Peltura) liolopyga. In 18614 the reference of 

these trilobites was changed from the Hudson Eiver group to the Quebec 

group 5 and a little later a strong defense was made of the reference of 

the fossils of the Georgia slates to the Hudson Eiver and Quebec groups^ 

the authority of Sir William E. Logan for the stratigraphic position of 

the rocks being cited.5 Discovering that the proposed generic name, 

Barrandia, was preoccupied, he substituted the name Olenellus in 1862.6 

This js the first introduction of the name which is now given to the 

Lower Cambrian fauna.

The last reference of Prof. Hall to the fauna is the proposal of the 

genus Discinella for what he considered to be a small brachiopod, but 

which investigation proves to be the operculum of Hyolithellus micans."1

In notes on the fossils of Washington County, Dr. Asa Fitch8 de1 Hall, James: Letter on certain fossils of the red aandrock of llighgate. 3d Annual Report on the 

Geology of the State of Vermont. Burlington, 1847, p. 31.

1 Remarks upon the trilobites of the shales of the Hudson Kiver group. Paleontology of New York, 

vol. 3, supplement to vol. 1,1859, pp. 525-529.

8 Note upon the trilohites of the shales of the Quebec group in the town of Georgia, Vermont. 

13th Annual Report State Cab. Nat. Hist., I860, pp. 113-119. Report upon the geology of Vermont, vol. 

1,1801, pp. 307-372.

4 Hall, James; Correction for the 13th Ann. Rep. 14th Ann.Rep. State Cab. Nat. Hist., J8C1, p. 110.

6 Hall, James: Letter on the Primordial of America. Soc. g6ol. France, Bull., 2e sorvol. 19, 18G2,pp 

725-734.

6 Supplementary note to 13th Ann. Rep. State Cab. Nat. Hist. N. Y. 15th Ann. Rep. State Cab. Nat. 

Hist.N Y., 18,62, p. 114.

7 Notes on some new and imperfectly known forms among the brachiopoda, etc. 23d Ann. Rep. N. 

Y. State Mus. Nat. Hist., 1873, p. 246.

8 A Historical, Topographical, and Agricultural Survey of the County of Washington. Trans. N. T. 

State Agric. Soc. for 1849,1850.
150 THE CAMBRIAN. [BULL. 81.

scribes Palceophycus rectus (p. 862), Buthotrephis (?) asteroides (p. 863), 

Helminthoidichnites tennis (p. 866), from the slates now referred to the 

Lower Cambrian. He also mentions Palceophycus virgains Hall, Buihotrephis (?) flexuosus Emmons (p. 862), and Gordia marina of Emmous 

as Helminthoidichnites marina (p. 868).

The fauna of the " Eed sandrock" of Vermont was first discovered 

by Prof. 0. B. Adams in 1847, 1 who sent the specimens to Prof. James 

Hall. The latter identified Conocephalus, but did not refer the fossils 

to any geological horizon. Prof. Adams in 18482 mentions the Couocephalus and also an Atrypa, like Atrypa hemispherica (equivalent to 

Camerella f antiquata Billings).

Mr. E. Billings, as paleontologist to the Geological Survey of Canada, 

took up the study and correlation of the older paleozoic faunas, and 

was the first to assign the fossils described by Prof. Hall to a pre-Potsdam horizon and to correlate the strata containing them with the 

Upper Primal sandstones of Pennsylvania, and the limestones of the 

Straits of Belle Isle.3

In 1861 he described a number of Lower Silurian fossils from the 

" Potsdam group " of Vermont and assigned the following species to the 

horizon of Paradoxides thompsoni of Hall: Palceophycus congregates, P. 

incipiens, Obolella (Kutorgina) cingulata, Orthisina festinataj Camerella 

antiquata,Conocephalites adamsi} C. teucer, C.vulcanus, C.arenosus.

A little later he published a note on the " Eed sandrock " formation 

of Vermont,4 in which he refers the formation to the base of the Lower 

Silurian somewhere within the horizon of the Potsdam and identifies 

Conocephalites from the formation. In reprinting in 1865 the article 

published in 18615 he correlates the primordial fauna of the u Eed sandrock " of Vermont with that of Newfoundland and Labrador, and refers 

them to the Potsdam group, stating that there is no paleontojogical 

evidence of precise similarity of age, but the general affinities and scope 

of the fossils and the physical relations of the rocks prove that there 

can be no great difference.

Under the title " On some new species of fossils from the limestone 

near Point Levi, opposite Quebec." 6 Mr. Billings described the fauna 

collected by the Geological Survey of Canada from the limestone conglomerate. He designated the rocks simply as Limestone Kos.1, 2, 3, 

and 4, not recognizing at the time that the bowlders were transported 

and imbedded in a secondary deposit; and that the fossils in thebowl1 3d Annual Report on the geology of the State of Vermont. Burlington, 1847, pp. 31. 

* On the Taconic rocks. Am. Jour. Sci., 2d ser., vol. 5,1848, p. 109.

3 Paleozoic fossils, vol. 1. Containing descriptions and figures of new or little known species of organic remains from the-Silurian rocks. 1860-1865. Montreal, 1865, pp. 1,2.

4 Billings, E.: On the age of the Ked sandstone formation of Vermont. Am. Jour. Sci., 2d ser., vol. 

32,1861, p. 232.

8 Billings, E.: Palezoic fossils, vol. 1,1865, p. 371.

6 On some new species of fossils from the limestone near Point Levi, opposite Quebec. Canadian 

Nat., voL 6,1860, pp. 301-324.
WALCOTT.] PALEONTOLOGY APPALACHIAN. " 151

ders were of Upper Cambrian age while those of the limestone matrix, which resembled in character the limestone of the bowlders, was deposited in situ, and carried the Calciferous fauna. As far as I have 

been able to separate the species by a study of the material from the 

bowlders and the limestone matrix the following may be referred to the 

Upper Cambrian or Potsdam fauna: Camerella calcifera ?, Agnostus 

americanus, A. orion, A. canadensis, Dikeloceplialus magnlficus,D.planifrons, D. belli, D. oiveni, D.megalops, D. cristatuSj Arionellus cylindricm, 

A. subclavattis, Menocephalus sedgwicJci, M. globosus, Conocephalites zenJceri. Asaphus illwnoides.

Mr. T. Devine, of Quebec, having discovered several nearly perfect 

trilobites in the conglomerate limestone at Point Levi, described two 

species of them. One as Olenus V loganij the other as Menocephalus salteri.* In a foot-note accompanying the description of Olenm ? logani 

Mr. Billings states that the species is unquestionably congeneric with 

those which he had described as Dilcelocephalus belli and D. oweni from 

the same locality.

To the species described from* Point Levi in 1860 Mr. E. Billings 

added in 18653 Dilcelocephalus devinei, D. hisingeri, D.affinis, D. sesostris, D. selectus, and D. pauper. He also figured in this connection Olenus ? logani, Devine and Menocephalus salteri, Devine.

In 1872 Mr. Billings returned to the study of the fossils of the older 

Paleozoic rocks and described one new genus and several species found 

in bowlders, of several beds of conglomerate at St. Simon, below Quebec, as follows: The genus Obolellaand the species Obolella gemma and 

0. circe, Platyceras primwvum, Hyolithes americanus, H. communis, H. 

princeps, jff. micans. On page 240 of the same volume the genus Hyolithellus is proposed for the species Hyolithes micans; and on page 351 

he notes the discovery of Salterella pulchella in the Winooski marble 

of Vermont.4

The Cambrian fauna of northern Vermont was* further enlarged in 

1884 by Prof. E. P. Whitfield 5 describing Orthisina orientalis (p. 144), 

Nothozoa vermontana (p. 144), Dilcelocephalus, marcoui (p. 150), and 

Angelina hitchcocTci (p. 148); all of which were referred by him to the 

horizon of the Potsdam sandstone.

The oldest Phyllopod crustacean, Protocaris marshi, was described 

by Mr. C. D. Walcott 6 in 1884 from the Georgia slates of Vermont,

1 Description of a new trilohite from the Quebec group. Canadian Nat., vol. 8,1863, p. 95.

»Op.cit.,p.2lO.

3 Paleozoic "Fossils, vol. 1,1805, pp. 195-200.

4 On some new species of Potsdam fossils. Canadian Nat., vol. 6, new ser., 1872, pp. 213-226,240.

Note on the discovery of fossils in the "Winooski Marhle" at Swanton, Vermont. Am. Jour. Sci., 

3d aer., vol. 3,1872, p. 145. Canadian Nat., now ser., vol. 6,1872, p. 351.

'Notice of some new species of Primordial fossils in the oollections of the Museum, and correction 

of previously described species. Am. Mus. Nat. Hist. Bull., vol. 1,1884, pp. 139-154.

u On the Cambrian faunas of North America; preliminary studies. U. S. Geol. Survey, Bull. No. 10, 

1884, p. 50.
152 THE CAMBRIAN. (BULL. 81.

where it is found in association with Olenellus thompsoni and 0. vermontana. The latter was referred to the new genus Mesonacis in 1885. 1

Mr. S. W. Ford began, about 1808, a study of the rocks and fossils 

of the hills east of Troy, New York, from which vicinity the first fossils 

of the Olenellus fauna, found in New York, were obtained. These 

were described by Prof. Hall, in .1847, and referred by him to the Hudson Eiver group. Entering into correspondence with Mr. B. Billings, 

and comparing the fauna he found at Troy with that from below Quebec, referred by Mr. Billings to the Lower Potsdam, he concluded that 

the strata containing the fauna at Troy should be referred to an equivalent horizon. In his first papera he mentions finding eighteen species, 

eight of which are referred to described species and ten remained to be 

described. Mr. Ford published a number of papers from 1871 to 1885,3 

in which he described the rocks, and fossils found in them, that occur 

near Troy, and also a little south of Schodack landing, in Columbia 

County, N. Y. The fossils described by him are: Protocyatlms rarum, 

Archceocyathus rensselcericum, Ololella nitida, Scenella rettisd, HyolitUes 

emmansi, R. impar, Agnostus nobilis, Leperditia troyensis, Microdiscus 

meelci, M. speciosus, and Solenopleura nana. One of the most, interesting of Mr. Ford's studies is that on the embryonic development of 

Olenellus asaphoides. From the data thus obtained he decided that 

the Olenellus fauna followed the Paradoxides fauna in time.4

1 Paleozoic notes; new^enus of Cambrian trilobites Meaonacis. Am. Jour. Sci., 3d ser.,vol. 29,1885, 

pp. 328-330.

"Ford, S. W.: Notes on'the primordial rocks in the vicinity[of Troy, New Tork. Am. Jour. Sci., 3d 

ser., vol. 2,1871, pp. 32-34. Canadadian Nat., new ser., vol. 6,1872, pp. 209-212.

3 Descriptions of some new species of primordial fossils. Am. Jour. Sci., 3d ser., yol. 3,1872, pp. 419- 

422.

On some new species of fossils from the Primordial or Potsdam group of Rensselaer County, New 

York. Am. Jour. Sci., 3d ser., vol. 5,1873, pp. 211-215.

Remarks on the distribution of the fossils in the Lower Potsdam rocks at Troy, New Tork, with de. 

scriptions of a few new species. Am. Jour. Sci., 3d ser., vol. 6,1873, pp. 134-140.

Note on the discovery of a new locality of primordial fossils in Rensselaer County, New Tork. 

Am. Jour. Sci., 3d ser., vol. 9,1875, pp. 204-206.

On additional species of fossils from the primordial of Troy and Lansingburg, Renaselaer County, 

New Tork. Am. Jour. Sci., 3d ser., vol. 11,1876, pp. 369-371.

Note on Microdiscus speciosns. Am. Jour. Sci., 3d ser., vol. 13,1877, pp. 141,142.

On some embryonic forms of trilobites from the primordial rocks at Troy, New Tork. Am. Jour. 

Sci., 3d ser., vol. 13,1877, pp. 265-273.

Two new species of primordial fossils. Am. Jour. Sci., 3d ser., vol. 15,1878, pp. 124-127.

Note on Lingulella ecdata. Am. Jour. Sci., 3d ser., vol. 15,1878, pp. 127-129.

Note on the development of Olenellus asaphoides. Am. Jour. Set., 3d ser., vol. 15,1878, pp. 129,130.

On certain forms of Brachiopoda occurring in .the Swedish primordial. Am. Jour. Sci., 3d ser., vol. 16, 

1878, pp. 364-366.

Note on the trilobite Atops trilineatug of Emmona. Am. Jour. Sci., 3d ser., vol. 19,1880, pp. 152,153.

Remarks on the genus Obolella. Am. Jour. Sci., 3d ser., vol. 21,1881, pp. 131-134.

On additional embryonic forms of trilobites from the primordial rocks of Troy, New Tork. Am. 

Jour. Sci., 3d ser., vol. 22,1881, pp. 250-259.

Note on the discovery of primordial fossils in the town of Stuyvesant, Columbia County, New Tork. 

Am. Jour. Sci., 3d ser., vol. 28,1884, pp. 35-37.

4 Embryonic forms of trilobites from the primordial rocks of Troy, New Tork. Am. Jour. Sci., 3d 

ser., vol. 22,1881, pp. 250-259.
WALCOTT.] PALEONTOLOGY APPALACHIAN. 153

In 1880 Prof. William .B. Dwight announced tlie discovery of the 

fauna of the Potsdam zone in limestone near Jfoughkeepsie, New York. 

He gives a list of eleven species as follows: l

Lingulepis pinnaformis. Ptychoparia (Conocephalites) 11. sp.

Lingnlepis minima. Dilcelocephalns sp.

Liugulepis acnmiiuita (probably). Pfcychaspis sp.

Obolella(LiiignleUa) prima. Stroinatoccrium ?

Obolella sp. Remains of crmoid columns.

Platyceras sp.

The review of the Olenellus or Lower Cambrian fauna by Mr. C. D. 

Walcott in 1886 2 resulted in the description of the following species 

from Vermont: Glimacograptus ? emmonsi (p. 93), Orthisina transversa 

(p. 121), Scenella ? varians (p. 127) and Miorodiscusparlceri (p. 157). This 

was followed in 18873 by an account of the discovery of a number of 

new species of fossils from the Upper Tacouic slate of Einmons in 

Washington County, New York. The new species described are as 

follows:

Lingulella granvillensis. Leperditia (I) dermatoides.

Liuuarssonia taconica. - Microdiscusconnoxus.

Orthis saleinensis. Olenoides foidi,

Modiolopsis (??) prisca. Solenoplenra (?) tnroida.

Hyolithellus raicans, var. rngosa. Pfcychoparia (f) fitchi.

Aristozoa rotundata. P. (?) clavata.

In describing a section of the Cambrian rocks in northern Vermont 

notice is taken by Mr. Walcott of the occurence in the upper beds of a 

fauna resembling that of the Upper Cambrian or Potsdam zone.4

In a paper announcing the discovery of the fossiliferous strata of the 

Paradoxides zone at Stissing Mountain, Dutchess County, New York, 

Prof. W. B. Dwiglit5 identified Eyolithes billingsi ? (p. 143) and described 

as new Leperditia clenina (p. 144), Kutorgina stissingensis (p. 145), and 

Olenoides stissingensis (p. 147), correlating the fauna \dth that of the 

Middle .Cambrian of the Eocky Mountain province.

In a review of the Lower Cambrian fauna by Mr. C. D. Walcott, prepared for the Tenth Annual Eeport of the U. S. Geological Survey, a 

number of new species and genera are proposed, most of which are described in a preliminary paper published in the Proceedings of the U. 

S. National Museum.6 These are Archceocyathus dioighti (p. 34), Plan1 Recent explorations in the Wappinger Valley limestone of Dutchess County, New York. No. 5; 

Discovery of fossiliforons Potsdam strata at Poughkeepsie, Now York. Am. Jour. Sci.,3d 8er.,vol. 

31,1886, p. 131.

1 Second contribution to the studies of the Cambrian faunas of North America. 17. S. Geol. Survey, 

Bull. No. 30,1886.

8 Fauna of the " Tipper Taconic " of Emmons, in "Washington County, Now York. Am. Jour. Sci., 

3d ser., vol. 34,1887, pp. 187-199.

4 Second contribution to the studies of the Cambrian faunas of North America. TJ. S. Geol. Survey, 

Bull. No. 30,1886, pp. 17,19.

8 Recent explorations in tho "Wappinger limestones and other formations of Dutchess County, New 

York. Am. Jour. Sci-, 3d ser., vol. 38,1889, pp. 139-153.

0 Descriptive notes of new genera and species of tho Lower Cambrian) or Oleuellns zone of North 

America. U.S.Nat.Mns.Proc., vol. 12,1889, pp. 33-46.
154 THE CAMBRIAN. [BULL. 81.

olites annularius (p. 34), Agnostus desiderates (p. 39), and ZacantJioides 

eatoni (p. 45), from Washington County, and Camerella minor (p. 36), 

from Dutchess County, New York; Kutorglna cingulata, var. swantonensis (p. 30) from northern Vermont.

In 1890 the following new species were described: 1 TracJiyum vetustum, 

Dawson, from Metis, Canada; Phyllograptus cambrensis, from Georgia, 

Vermont; Stenotheca (?) rugosa var. acuta-costa, erecta, and levis, Platyceras dawsoni, from St. Simon, Quebec; Olenoides ellsi, from below 

Quebec, Canada; 0. desiderata,frow HighgateSprings, Vermont; Conocoryphe reticulata, from Washington County, New York; Ptychoparia 

metisensis and Agraulos redpathi, from below Quebec.

SOUTHERN APPALACHIAN DISTRICT.

NEW JERSEY, ETC.

The Cambrian fauna of New Jersey, Delaware, Pennsylvania, Maryland, and Virginia is thus far restricted to the presence of the Annelid 

boring Scoliihus linearis. It is extremely probable that trilobites and 

other fossils will be found in the Granular Quartzite series, or the basal

quartzite and the immediately superjacent shales and limestones.

«

TENNESSEE.

The Cambrian fauna of Tennessee consists of Scolithus linearis tubes 

found in the Chilhowee sandstone; while in the shales just above the 

sandstone occur numerous Annelid trails, a species of Hyolithes like 

H. americamis, an Ostracod crustacean, Isoxys cliilhoweana, and a species of Olenellus closely allied to Olenellus thompsoni and 0. asaphoides 

in that portion of the head preserved.2

From the upper part of the Knox shale Prof. J. M. Safford3 has 

named, without description or illustration, several species, as follows:

Crepicephalns similis, Safford.

roanenais, Safford.

tennesseensis, Safford. 

Lonchocephalus fecundus, Safford. 

Agnostus arcanus, Safford. 

Lingula prima ? Conrad.

Quite a large fauna occurs at this horizon in the collections of the 

Geological Survey which has not yet been studied with care. As far 

as examined it appears to be of the type of the Upper Cambrian of the 

Mississippi Valley.

1 Walcott, 0. D.: The fauna of the Lower Cambrian or Olenellus zone. 10th Ann. Hep. TJ. S. Geol. 

Surv., 1890, pp. 598-855. 

2 Ibid., p. 626. 

8 Geology of Tennessee. Nashville, 18C9, p. 212.
WALCOTT.] UTAH AND NEVADA. 155

GEORGIA.

A trilobite was sent to the great exhibition in London in 1851 said 

to be found somewhere in Georgia. Mr. J. W. Salter 1 describes the 

species as Conoceplialus antiguatus, comparing it with C. striatus of the 

Primordial rocks of Bohemia. The exact locality from which this species came was not known until collections were made in northwestern 

Georgia by the U. S. Geological Survey in. 1885. It was then found to 

be associated with a fauna much like that of the Middle Cambrian fauna 

of the Rocky Mountains. The specimens occur in and upon siliceous 

concretions imbedded in the Coosa Valley shales of Floyd County and 

to the southwest in Alabama.

A second species was described by Mr. C. D. Walcott in 1889 as Olenoides curticei. It occurs on and in siliceous concretions found in the 

shales of the Coosa Yalley.2 .

ROCKY MOUNTAIN PROVINCE.

The area of Cambrian rocks in this province includes the Cambrian 

outcrops of northern and western Utah, Nevada, eastern Idaho, and 

the Gallatin Eiver district of Montana. The Canadian extension is considered separately.

UTAH AND NEVADA.

During the progress of the geological survey of the fortieth parallel, 

under the charge of Mr. Clarence King, Prof. F. B. Meek described two 

species of trilobites from Antelope Spring, Nevada, Pardoxides(?)nevadensis and Conocoryphe (Conocephalites) Ungi, referring them to the Primordial zone.3

In the following year Prof. J. D. Whitney exhibited before the California Academy of Sciences some fossils that had been collected by Mr. 

J. E. Clay ton near Eureka, Nevada. He referred them to the age of the 

Potsdam sandstone, identifying Agraulos oweni, M. and H., or a species 

closely resembling it; Lingulepis prima, Obolella, Conocoryphe, Paradoxides, etc.4 A note on the occurrence of the Primordial fauna in 

Nevada was also sent to the American Journal of Science by Prof. 

Whitney. In this he mentions the occurrence of certain Primordial 

species, and the persistence with which these constantly recurring trilobites and brachiopods are found at various localities. In Bohemia 

they occur in argillaceous "shales; throughout the United States, from 

New York to the Eocky Mountains, in the Potsdam sandstone, or in 

shales or slates; in Texas, and now in Nevada, in limestones.5

1 Ou the fossils of the Liugula-flags or "Zone Primordiale." Quart. Jour. Geol. Soo., London, vol. 

15,1859. p. 554.

2 Descriptions of new genera and species of fossils from the Middle Cambrian. TJ. S. National Museum Proc.,vol. 11, 1889, p. 443.

3 Descriptions of fossils collected by the United States Geological Survey, under the charge of Clarence King, esq. Phila. Acad. Sci., Proc., vol. 22, 1870, pp. 62-64.

4 [On some fossils from Eureka, Nevada.] California Acacl. Sci., Proo., vol. 4,1871, p. 200. 

6 Note on the occurrence of the "Primordial Fauna" in Nevada. Am. Jour. Sci., 3d ser., vol, 3, 

1872, p. 85. o .
156 THE CAMBRIAN.

In the Sixth Annual .Keport of the U. S. Geological Survey of the 

Territories, Prof. F. H. Bradley states that his section along the Wasatch range of Utah is not complete. The bedded quartzites, referred 

to the Potsdam from the character of the overlying strata, rest unconformably upon the " Metamorphic." No fossils were found in the 

quartzite or in the superjacent gray and calcareous shales. The limestone above the shales is referred to the Niagara.1

During the progress of the survey west of the one hundredth meridian Mr. G. K. Gilbert visited the Antelope Spring locality, discovered 

by Mr. J. E. Clayton, and mentioned by Prof. Whitney when calling 

attention to the Primordial fossils found there. The fauna occurs in a 

blue gray, calcareous shale, some 200 feet in thickness. In addition to 

the species described by Mr. Meek, he collected Batliyurellus (Asaphiscus) wlieeleri, Agnostus, and Disciria. Beneath the blue gray shales is 

a massive gray limestone, 900 feet in thickness, superjacent to a vitreous sandstone.2 From our present knowledge of the Cambrian rocks 

in Nevada, the gray limestone, blue gray shales, and an upper gray 

limestone some 200 feet in thickness all belong to the Cambrian.

The section of the Oquirrh range at Ophir City, Utah, was found by 

Mr. Gilbert to have, near its base, 100 feet of light gray limestone containing Conocoryphe and Dikelocephalus. Subjacent to this a massive limestone with coralline mottling extends downward some 300 feet 

to an argillaceous shale, in which Mr. J. E. Clayton found Olenus gilberti? At the south end of the Timpahute range of eastern Nevada 

Mr. Gilbert also discovered a succession of shales and sandstones, in 

which he found Conocoryphe in the lower portion, and above, a band 

of purple ripple-marked vitreous sandstone, with bauds of siliceous 

shale.4 The descriptions of Olenus (Olenellus) gilberti and 0. (0.) lioivelli of Meek are printed on pages 182 and 383 of Mr. Gilbert's report.

In the same volume Mr. E. E. Howell states that at Pioche, Nevada, 

the massive quartzite forming the base of the section is subjacent to 

about 400 feet of arenaceous and calcareous shales of a reddish yellow 

color, containing in the more calcareous portions several types of 

Primordial fossils in great abundance? From the material found by 

Mr. Howell, Mr. Meek described two species of trilobites, Olenellus 

hoicelli and 0. gilberti.

On the map accompanying the Wheejer survey reports, published 

in 1874, the Cambrian rocks are included under the same color with 

those of the Silurian.

1 Report of Frank H. Bradley, geologist of the Snake River division. TJ. S. Geol. Surv. of the Terr., 

Gth Ann. Hop., 1873, p. 194.

2 Report on the geology of portions of Nevada, Utah, California, and Arizona, examined in the years 

1871 and 1872. Report on Geog. and Geol. Espl. and Survey west of the 100th meridian, in charge of 

Lieut. Geo. M. Wheeler, vol. 3, Geology, 1875, p. 167.

3 Op. cit., pp. 166,167.

»0p.cit.,p. 169.

6 Report on the geology of portions of Utah, Nevada, Arizona, and New Mexico examined In the 

years of 1872 and 1873. Rept. Geog. and Geol. Expl. Sur. west of the 100th mer., in charge of Lieut. 

Geo. M. Wheeler, vol. 3, Geology, 1875, p. 258.
WALCOTT.J UTAH AND NEVADA. 157

A reconnaissance of the northwestern portion of the Wasatch Mountains in Utah was made by Prof. F. H. Bradley in 1872. He found that 

the crest and eastern slopes are composed of quartzite and limestone.

The former, a white and ferruginous quartzite, 1,500 feet in thickness, was referred to the Potsdam, and a band of superjacent gray 

calcareous "shale, 1,000 to 1,200 feet thick, to the Lower Silurian. The 

section as arranged by Prof. Bradley is as follows: x

3. Blue and gray magnesian limestones, partly pebbly, \ Upper ? and 

l,900to 2,000 feet................................. > Lower

4. Gray calcareous shales, 1,000 to 1,200 feet ........... ; Silurian.

" 5. White and ferruginous quartzite, base pebbly, 1,500 ?

feet.............................................. $ pofc8damUnder the title of "Paleozoic subdivisions of the fortieth parallel" Mr. Clarence King describes the strata referred to the Cambrian 

system. This includes 12,000 feet of quartzites and argillites in the 

Big Cottonwood Canon section of Utah, superjacent to which is a shaly 

zone some 75 feet in thickness, carrying well defined Primordial fossils. 

He says:

Comparing the quartzitee and argillites with those of the Cambrian section in 

Wales, the likeness is too great to pass unnoticed, and iu view of the enormous developments of these low-lying rocks, as compared with the Silurian lying above the 

Primordial horizon, I have determined to draw a line at the upper limit of the Primordial period to include the uppermost members of the Potsdam epoch and to consider the whole underlying conformable series as Cambrian down to the point of 

their nonconformity with the Archean. In the extreme east of our work, in the region of the Rocky Mountains, the Cambrian formation is of variable thickness and 

nowhere reaches an exposure of over 100 feet. In middle Nevada the uppermost zone 

of the Cambrian, equivalent to the calcareous and argillaceous shales of the 

Wahsatch, is an immense body of dark limestones at least, 3,000 feet in thickness 

carrying Primordial fossils-throughout; the downward continuation of the series 

being there entirely hidden by the overlying Quaternary desert.2

This general definition of the Cambrian is accompanied by a list of 

the fossils described by Messrs. Hall and Whitfield.

The Cambrian section of Big Cottouwood Canon referred to by Mr. 

King is described by Mr. S. F. Emmons with more detail.3 On the 

west side of Box Elder Peak, near the little village of Call's Fort, in 

a body of dark blue argillaceous slates in the lower portion of the Ute 

limestone body, Mr. Emmons states that the following fossils of the 

Quebec group were found: Dikelocephalus wasatcliensis, D. gothicus, 

Crepic&plialus (Loganellus) guadrans, and Lingulepis ella.* In the section on Muddy Canon, within 25 feet of the base of the series, occurs a 

body of calcareous shales, interstratified with narrow beds of a dark,

1 Explorations of 1872; United States Geological Survey of the Territories,"under Dr. F. V. Hayden; 

Snake River division. Am. Jour. Sci., 3d ser., vol. 6,1873, p. 194.

2 King, Clarence: Paleozoic subdivisions on the 40th parallel. Am. Jour.Sci., 3d ser., vol. 11,1876, p. 

476.

3 Hague, Arnold, and S. F. Enjmons; Descriptive Geology. TJ, S. GeoJ. Expl. of the Fortieth Par. 5 

vol. 2, 1877, pp. 366, 367. 

«0p.cit.,p.405.
158 THE CAMBRIAN. [BULL.81.

fine-grained limestone, which contains abundant organic remains. 

Two species were recognized, Dilcelocephalus quadriceps and GonoceppJialites subcoronatus.1 The reference of the fossils at Call's Fort and 

Muddy Canon to the Quebec group was on the authority of the paleontologists. More recent studies of this fauna, by Mr. Walcott, in connection with the section at Big Cotton wood Canon prove that the fauna 

mentioned at these localities is a portion of the Middle Cambrian fauna, 

and that the Tipper Cambrian strata are absent in the section by nondeposition."

In the Weber Canon region of the Wasatch Mountains, 800 to 1,000 

feet beneath limestones referred to the Devonian, there were obtaiiled 

from a shaly limestone three forms of trilobites, which Mr. Emmons 

thought probably indicated the horizon of the Potsdam group. One 

was identified as Ogygia parabola and another as Crepicephalus allied to 

C. diadematus?

In the Oquirrh Mountains, at Ophir City, Utah, the section discloses 

a thickness of about 400 feet of compact reddish white Cambrian 

quartzite, above which are about 100 feet of greenish yellow clay slate, 

in which numerous trilobites and primordial fossils occur.3

In the Schell Creek Mountains of Nevada there are limestones in 

which primordial fossils have been found overlying heavy bodies of 

quartzite. Among the organic remains of this range two species have 

been identified : Crepicephalus (Loyanellus) anytus and Llngulepis mcera.*

At the northern end of Pogouip Ridge, of the White Pine Mountains 

of central Nevada, Mr. Arnold Hague mentions the presence of obscure 

outcrops of mica slates and black arenaceous and argillaceous slates 

and shales, in turn overlaid by an undetermined thickness of a compact, 

vitreous, steel-gray* quartzite, closely resembling the Cambrian quartzites of other Nevada localities. Above this quartzite, and forming the 

lower beds along the greater part of the ridge, occurs the Pogonip limestone, which extends to the top of Pogonip Mountain, with a thickness 

of from 3,000 to 4,000 feet of strata. They dip with an angle of 24° to 

30° eastward. The lower beds are a fine-grained, somewhat siliceous, 

black limestone, varying considerably in compactness and bedding, and 

frequently passing into calcareous shales. Higher up in the series, they 

develop more of a dark blue color, banded with layers of fine arenaceous limestones and occasional cherty bands a few inches in thickness.5 

From the lower beds of the limestone series he collected thirteen species 

of Upper Cambrian fossils.

Mr. Hague states that in Eureka mining district, northwest of White 

Pine, the section of Prospect Mountain has the same lithologic habit as 

that at White Pine, and carries throughout the greater part of the forma-

'Op. cit., p. 410. "Op. cit, p. 444 

20p. cit., p. 377. <0p. cit., p. 486.

'Hague, Arnold, and S.F. Emmona: Pescriptive Geology. TJ. S, Gool. Expl. of the 40th Par. 5 

Clarence King, vol. 2,1877, pp. 642,543,
WALCOTT.] UTAH AND NEVADA. 159

tion Primordial fossils, showing beyond doubt that the two series of 

beds are the same and equivalent to the Potsdam sandstone of Wisconsin. This statement is followed by a list of fifteen species, all of which 

belong to the Upper Cambrian fauna.1

The collections made by the officers of the Fortieth Parallel Survey 

were studied and reported upon by Messrs. Hall and Whitfield. Of 

the fauna referred to the Potsdam period they say: " Although there is 

not a single species common to the two regions, yet there is such a close 

generic resemblance as to leave no doubt whatever of the positive identity of the formations." They mention the resemblance between the 

fauna referred to the Potsdam zone in Texas and the Upper Mississippi 

Yalley, Wisconsin, Minnesota, etc.2 In speaking of the trilobites from 

the base of Ute Peak, Wasatch range, Utah, they state that the fauna 

is referred to the Quebec group on the evidence of the Brachiopodus 

and Molluscaii fauna.3 There must have been some confusion in relation to the occurrence of trilobites and the Molluscan fauna, as the trilobites belong to the Lower Cambrian zone, and have nothing in common with the fauna which they refer to the Quebec group.

In the comprehensive review of the geology of the fortieth parallel, 

Mr. Clarence King describes the Cambrian and Silurian rocks largely 

from the data published in the volume of Messrs. Hague and Emmons4 

and in the recapitulation of the Paleozoic he gives a condensed description of the Cambrian as known to him in Utah and Nevada. The base 

of the Cambrian is never seen. This is explained by the fact that the 

Cambrian sediments accumulated in the deep valleys between the ArcheauridgeSj and that the lower beds have not subsequently been brought 

up to the surface. Under the term Cambrian he includes all of the rocks 

of the lowermost Paleozoic exposures up to and including the whole of 

the Primordial, thus following approximately the eastern nomenclature. In describing the rocks referred to the Cambrian he says:

Thus far, among the reported occurrences of the rocks of this horizon in the Cordilleras, the locality at the mouth of Big Cottonwood Canon must remain as the finest 

example nud the stratigraphical type. The lowest member the Cottonwood slates,' 

a group about 800 feet thick, which here rest upon highly metaniorphic Archeau 

schists Las thus far yielded no organic forms. Though searched by us with considable care, it presented no indications of life. The rocks are dark blue, dark purple, 

dark olive-green, and blackish argillites, all highly siliceous, and as a group sharply 

defined from the light-colored quartzitic schists which conformably overlie them. 

This second group, by far the greatest of the whole Cambrian series, is a continuous 

zone of schists which have a prevailing quartzitic character, though varied with considerable amount of argillaceous matter. It would seem to be the product of a finegrained arkose formation, simply compressed into dense schists. From 8,000 to 9,000 

feet thick, it has a general uniformity of lithological condition from bottom to top,

1 Op. cit., pp. 547, 548.

'Hall, James,and B.P.Whitfield: Paleontology (of the 40th Parallel). General remarks. U.S. 

Gcol. Survey of tlio 4(Kh Parallel, vol. 4,1877, pp. 199, 200.

s Op. cit., p. 200.

«Systematic Geology: TJ. S. Geol. Exploration of the 40th Parallel, Clarence King, geologist in 

pharge, vol. 1,1878, pp. 154-189.
160 THE CAMBRIAN. [BULL.SL

except that in the region of Twin Peaks are some phlogopite schists and siliceous 

zones carrying considerable mus.covite. The phlogopite members recur in the Egan 

Caiiou region. The prevailing colors of this member are gray, greenish gray, drab, 

and pale brown; never dark colors. Conformably overlying it are 2,500 to 3,000 feet 

of cream-color and salmon- color and white quartzites and quartzo-feldsites. Occasional sheets of conglomerate are seen in the quartzites not far below the summit of 

the Cambrian.1

The details of the Cottonwood Canon section to this point have not 

been quoted, as these rocks are beneath the line provisionally drawn 

between the Cambrian and pre-Catnbrian rocks. This will be noticed 

under the description of the Cambrian rocks of the Rocky Mountain 

province. Above the quartzite series there is a thin series of green 

siliceous argillites which are usually not more than 75 or 80 feet thick, 

in which fossils of a Primordial type have been found. A description is 

given of the Cambrian as recognized in central Nevada, and a comparison made between it and the Cambrian of the Mississippi Valley and 

the Wasatch section. A complete list of the fossils of the Utah and 

Nevada Cambrian is given on page 231, and on page 233 a list of those' 

from the Quebec group, eight of which are from the Middle Cambrian 

zone, and will be mentioned under the description of the Cambrian 

fauna of the Rocky Mountain province. The geographic distribution 

of the Cambrian rocks and their mode of occurrence, as shown in crosssection, is represented on the sheets of the atlas accompanying the 

report.

In 1882 Mr. Arnold Hague published a preliminary report on the 

geology of the Eureka district,2 which was followed in 1883 by the 

abstract of a report on the geology of the district. 3 In this latter report a detailed description is given of the Cambrian rocks of the Prospect Mountain section. It is accompanied by a map of the district and 

a plate of sections showing the relation of the Cambrian rocks to the 

superjacent formations.

TLe fauna of the Cambrian rocks of the Eureka district was described and illustrated by Mr. C. D. Walcott in 1884. A short description of the range of the species is given, also a tabulation of the Paleozoic section of Central Nevada, showing the vertical range of genera.4 

Tliis was republished in 1886 with greater detail,5 accompanied by an 

original description of the Big Cottouwood Canon section (pp. 38, 39), 

and a section in the Highland range, 125 miles south of the Eureka 

section (pp. 33-35), with notes upon the section at Pioche and Ophir 

City.

'Op.cit.,pp.229,230.

2 Report [on work in Eureka district]. 2d annual report U. S. Geol. Survey, 1880-'81. pp. 21-35,1882.

3 Hague, Arnold: Abstract of report on geology of the Eureka district, Nevada. TJ. S. Geol. Surv., 

3d annual report, 1881,1882, pp. 237-290, 1883.

4 Paleontology of the Eureka district. TJ. S. Geol. Survey, Monograph vol. 8,1884. 

6 Second contribution to the studies of the Cambrian faunas of North America. T7. S. Geol. Surv.. 

Bull. No. 30,1880, pp. 30-33.,
WALCOXT.J IDAHO. 161

IDAHO.

In a letter to Prof J. D. Dana, dated Fort Hall, Idaho, July 7,1872, 

Prof. F. H. Bradley wrote to announce the discovery of the Quebec 

group. In a limestone he found many trilobites, some gasteropods and 

brachiopods, and beneath the limestone a compact ferruginous quartzite, which from its position he considered as representing the Potsdam 

sandstone.1 Near Malade City he discovered a series of limestones containing Conocoryphe, Bathyurus, Dikelocephalus, Aguostus, etc. He 

states in a later report that 

The first examination of these Malade rocks was made at a point where the section 

terminated below in a very quartzitic sandstone, which occupied the relative position of the Potsdam, aud was accordingly referred with doubt to that group in a letter extract which was published in the August number of the American Journal of 

Science. Later examinations have shown that this was really a part of the true 

Quebec, whose base is not here exposed.*

The fossils collected by Prof. Bradley were studied by Mr. F. B. 

Meek, who identified the genera Agnostus, Conocoryphe. etc., along 

with several genera of the Lower Silurian fauna, aud gave Prof. Bradley 

the paleontologic data for his correlation.3

It is to be borne in mind that at the time of the work referred to, the 

Quebec group was made to cover the horizons of the Potsdam, Calciferous, and Chazy of the New York section. Again, throughout the 

writings of Messrs. Hayden, Bradley, and Meek there are found many 

references to the Quebec group, of strata that belong to different formations. This confusion arose primarily from the misinterpretation of the 

mode of occurrence of the Upper Cambrian and Lower Silurian faunas 

at Point Levis, Canada, the typical locality of the Quebec group.

The Cambrian rocks north of Malade City were studied by Dr. A. 0. 

Peale in 1877, in the Portneuf and Bannock ranges. He also visited 

the Bear Eiver range. Several carefully measured sections are published with a summary of the rocks referred to the Silurian that will 

be referred to in the description of the rocks of Idaho.4

The northern end of the Portneuf range, in the vicinity of Mount Putnam, came within the Teton district of Prof. Orestes St. John. The 

central portion of the mountain is formed of ancient quartzite, alternating with slaty micaceous shale, which alternates with limestones 

above j and on the northern "terminus of Mount Putnam -there is an 

exhibition of the full series'of the Paleozoic formations as developed in 

this region. 5

1 On the discovery of the Quebec formation in Idaho. Am. Joar. Soi., 3d »er., vol. 4,1872, p. 133.

3 Bradley, Frank H.: Report of Frank H. Bradley, geologist of the Snake River division. U. S. Geol. 

Saw. of the Terr., 6th Ann. Rep., 1873, p. 201.

s Preliminary paleontologioal report, * * * with remarks on th» ages of the rooks, etc. U. S. 

Geol. Surv. of the Territories, embracing portions of Montana, Idaho, Wyoming, and Utah. 6th Ann. 

Rep., 1873, pp. 431, 432.

4 Report on the geology of the Green River district. 0. S. Geol. Surv. of the Terr., llth Ann. Rep. t 

1879, pp. 567-572, 599, 613-616.

6 Report of the geological field work of the Teton division. U. S. Geol. Surv. of the Ter^f, , llth 

Ana. Rep., 1879, pp. 477-484.

Bull. 81 11
162 THE CAMBRIAN. [BULL. 81.

On the map accompanying the twelfth annual report of the Haydeu 

survey, issued in 1883, the geographic distribu tion of the strata referred to the Silurian (which includes the Cambrian arid the quartzite 

referred to the Potsdam and a portion of the limestones referred to the 

Quebec) is delineated as it occurs in southeastern Idaho. This is based 

on the work of Messrs. Bradley, Endlich, St. John, and Peale, of the 

Haydeu survey.

MONTANA.

During the field season of 1872 Dr. F. V. Hayden made a geologic 

reconnaissance of certain portions of Montana and noted the presence 

of limestone on the Gallatiu Eiver, above Gallatiu City, that contained 

numerous fossils. The thickness of the entire series of strata referred 

to the Lower Silurian is estimated at 1,600 feet. The massive limestones referred to the Potsdam group are about 400 feet thick and 

pass gradually down into 50 feet of thinly laminated, cherty limestones 

or calcareous mud layers, with abundant organic remains. These are 

separated by a purplish sa ndstone that rests upon variegated shaly 

clays, yellow, green, etc., then hard, dull purplish brown quartzose 

sandstones, which in turn are underlaid by alternating sandstones 

and clays, the whole having a thickness of over 1,000 feet.1

The fossils collected were studied by Mr. F. B. Meek, who identified 

the genera Lingulepis, Conocoryphe, Bathyurus, Acrotreta, Hyolithes, 

and Agnostus from the beds Of the east side of the Gallatin Eiver.2

Strata of "Primordial age" were discovered by Messrs. Dana and 

Grinnell upon the southwestern slope of Little Belt Mountains and the 

south extremity of the Belt range of mountains ; these are referred to 

with certainty, owing to the finding of Primordial fossils.3

In 1884 Dr. F. V. Haydeu revisited the Gallatin Eiver locality, in 

company with Dr. A. C. Peale.4 The section near the mouth of the 

East Gallatin Eiver was studied in detail by Dr. Peale and two lithologically well defined groups determined.

In the report of the following year the East Gallatin group is spoken 

of as probably Middle Cambrian.5

In his administrative report to the Director of the U. S. Geological 

Survey for the field season of 1889, Dr. A. 0. Peale tabulates the Gallatin Eiver Paleozoic section, and includes under the Cambrian the 

Gallatiu limestone, 835 feet in thickness, and the Gallatin sandstone, 

415 feet. Beneath the Gallatin limestones are 5,000 feet of conglomer1 Report of F. V. Hayden, TJ. S. Geol. Sur. of the Terr., 6th Ann. Kep., 1873. p. 72.

2 Preliminary paleontological report, . . . with remarks on the ages of the rocks, etc. TT. S. 

Geol. Sur. of the Territories, embracing portions of Montana, Idaho, Wyoming, and Utah; 6th Anu. 

Kep., 1873, pp., 431, 432.

3 Geological report. 'Report of a geological reconnoissance from Carroll, Montana Terrritory, on 

the Upper Missouri, to the Yellowstone Park and return, made in the summer of 1875, by "Wni. Ludlow ; 1876, p. 22.

4 Administrative Report Montana Division. U. S. Geol. Survey, 6th Ann. Rep., 1884,-'85,1885, pp. 49- 

61.

<Ibid., U. S. Gtool. Survey, 7th Ann. Eejp. for 1885-'86,1888, p. 86.
WALCOTT.J CANADIAN EXTENSION. . 163

itic micaceous sandstones, with bands of siliceous limestones and indurated clay shales, which he refers to the Algonkian.1 

r

CANADIAN EXTENSION.

The discovery of rocks of Cambrian age in the western portion of 

Biitish Columbia is of recent date. During the summer of 1883 Dr. 

G. M. Dawson and Mr. E. G. McConuell investigated the Paleozoic rocks 

on the line of the Canadian Pacific Eailroadand discovered at the Crow 

Nest Pass a great thickness of limestone of Devonian age, beneath 

which is a great series of slaty and quartzite rocks. No fossils were 

found in the beds, but some were found in detached fragments, which 

are referred to the Cambrian.2 In the report published in 1886 Dr. 

G. M. Dawsoii says that of the rocks referred to throughout his report 

as Cambrian no complete general section can be offered. Along the 

line of the Columbia Valley the basal beds were not observed. The 

component beds of the great Cambrian series are, in the main, quartzites and quartzitic shales, passing into argillites, occasionally including 

limestones or more or less calcareous or dolornitic materials and conglomerates.3

Near Waterton Lake a section was measured 3,000 feet in thickness; 

another at South Kootanie Pass had a mininum (estimated) thickness 

of the outcropping Cambrian beds of 11,000 feet, and it included 

neither the summit nor the base of the series. Other sections were 

measured, but none were found in which the whole volume of the formation could be ascertained.4

Dr. Dawson compares these sections with that of the Wasatch Mountains of Utah; and more recent discoveries have shown that they are 

quite similar in character. If the view of separating the pro Olenellus 

beds from the Cambrian is accepted, most of the South Kootauie 

Pass rocks will be referred to the Algonkian, corresponding in this 

respect to the Algonkian (?) of the Big Cotton wood section of the 

Wasatch Mountains, Utah.

Dr. Dawson further states that Mr. H. H. Winwood announced the 

discovery of Cambrian fossils in the Kicking Horse Pass in a letter 

to the Geological Magazine in 1885.° .From among the specimens 

obtained at that time Mr. 0. D. .Walcott recognized Olenellus howelli 

and Olenoides lev is, trilobites characteristic of the Prospect Mountain 

group of Nevada. 6 Numerous other references occur in Dr. Dawson's 

report in connection with the description of the local details of the

 Administrative Report, Montana Division. U. S. Geol. Surv., 10th Ann. Rep., 1890, p. 131.

2 Dawson, Geo. M.: Recent geological observations on the Canadian Northwest Territory. Science, 

vol. 3,1884. p. 648.

S-Preliniinary report on the physical and geological feature of that portion of the Rocky Mountains 

between lat. 49° and 51° 30'. Geol. Survey Canada, new sor., vol. 1,1886, p. 157B.

«Op.oit.,p.l58B.

6 Geological age of the Rocky Mountains. Geol. Mag., new ser., dec. 3, vol. 2,1885, p. 240.

6 Preliminary report on the physical and geological features of that portion of the Rocky Mountains 

between latitudes 49° and 61° 30'. Geol. Surv. Canada, new ser., vol. 1,1886, p. 140B.
164 THE CAMBRIAN. [BULL. 81.-

geology. One of these refers to the finding of a specimen of Ptychoparia oweni M. and H. on the Cascade Eiver in debris brought down from 

the mountain, indicating the presence of the Cambrian in the Cascade 

Mountains.1

An admirable map accompanies Dr. Dawson's report, aud includes 

the region between latitude 49° and 50° 30'. The geographic distribution of the Cambrian quartzite series and its relations to the superjacent Carboniferous and Devonian rocks is delineated, and their stratigraphic position is shown in an accompanying diagrammatic section.

When exploring the Yukon district in 1887 Dr. Dawson 2 discovered 

that the country north of Dease Lake had a granitic nucleus with Paleozoic rocks on its flanks, ranging from the Cambrian to the Carboniferous. 

No details are given.

The detailed exploration of the Paleozoic rocks west of the great 

Archean area, near the border of British Columbia and Alberta, was 

undertaken by Mr. R. G. McConnell, and his results are presented 

in the annual report of the Canadian Survey for 1886. The Castle 

Mountain group, a great limestone formation, has a known minimum 

thickness of 7,700 feet. The lower portion is of Cambrian age, and the 

upper part forms the base of the Lower Silurian (Ordovician). Beneath 

the Castle Mountain group the Bow Eiver series forms a great thickness of dark colored argillites, associated with some sandstones, quartzites, and conglomerates. The portion exposed has an estimated thickness of 10,000 feet, and in the upper part of it occur the fossils menby Dr. Dawson, Olenellus gilberti, etc.3 The occurrence of fossils of 

Cambrian age in the lower portion of the Castle Mountain group is 

noted on page 28D of the report.

The fauna from the slates or shales at the base of the Castle Mountain group, in the Mount Stephen section, was described by Dr. C. 

Eominger in 1887,* and reviewed by Mr. C. D. Walcott in the following 

year.6

In noticing the two papers just mentioned Mr. E. G. McConnell gives 

a re'sume' of the section at Mount Stephen. He states that no fossils 

have been detected in the lower part of the Bow Eiver series, but specimens of Olenellus gilberti were found by Dr.^Dawson in 1884 about 2,000 

feet below the top of the formation.. The next fossiliferous zone occurs 

near the junction of Bow Eiver and Castle Mountain groups, where 

Paradoxides was found; and a third zone, between 3,000 and 4,000 feet 

higher up, carries the fauna described by Dr. Eominger.6

1 Op. oit., p. 143B.

2 Notes on exploration in Yukon District. Science, vol. 10,1887, p. 165.

3 Report on the Geological Structure of a portion of the Rocky Mountains, with a section. Geol. 

Surv. Canada, Ann. Keport, new ser., vol.2, 1887, pp. 24-30 D.

4 Description of Primordial fossils from Mount Stephens, Northwest Territory of Canada. Phila. 

Acad. Sci. Proc., 1888, pp. 12-19, PL I.

6 Cambrian fossils from Mount Stephens, Am. Jour. Sci., 3d ser., vol. 36,1888, pp. 161-166.

6 Notes on the geology of Mount Stephen, British Columbia. American Geologist, vol. 3, 1889, pp. 

23-25.
WAtcorr.] PALEONTOLOGY-! ROCKY MOUNTAINS. 165

Iii a "Note on the geology of the Selkirk Range," of British Columbia, Dr. George M. Dawson states that the Olenellus fauna lias been 

found 3,000 feet down in the Bow River series.1 He refers the Nisconlith, and the lower 15,000 feet of the Selkirk series, of the Selkirk section, to the Cambrian, and correlates them with the Bow Eiver and lower 

portion of the Castle Mountain series of the western side of the Rocky 

Mountains. (The details of these series are given in chapter iv, of this 

paper.)

PALEONTOLOGY.

The first description of Cambrian fossils from the Rocky Mountain 

province is that by Mr. F. B. Meek, in 1868, who described from the 

material discovered by Mr. Clay ton at Silver Peak, Nevada, Etlimopliyllum whitneyi and E. gracile.2 Shortly after he changed the reference 

of these species to Archseocyathus, making A. wliitneyi and A. gracile.3 

In 1870 he added Paradoxides f nevadensis and Conocoryphe (Conocephalites) Tdngi, from Antelope Spring, Nevada. From the known position 

of the genus Conocephalites the two species were referred by him to the 

Primordial zone.4

In 1872 Prof. J. D. Whitney calls attention to the occurrence of the 

Primordial fauna near Eureka, Nevada, at a locality discovered by 

Mr. J. E. Clay ton. He identified a species closely related to Agraulos 

oweni of Meek and Hayden, and fragments of the genera Conocoryphe, 

Paradoxides, Lingulepis, and Obolella.5 A notice of this discovery was 

also published in the proceedings of the California Academy of Sciences in the same year. (Vol. 4, p. 200.)

From the Upper Cambrian rocks of southeastern Idaho and southern 

Montana, Mr. F. B. Meek described in 1873 Iphidea f? sculptilis (p. 479), 

Agnostus lidens (p. 463), Conocoryplie (Gonocephalites) gallatinensis (p. 

485), Bathyurus f liaydeni (p. 482), B. serratus (p. 480), Bathyurelliis 

(Asaphiscus) bradleyi (p. 484), Bathyuriscus wheeleri (p. 485, foot-note). 

It is stated on page 465 that Bathyuriscus (Dikelocephalus ?) truncatus 

is described in the report. It does not, however, appear in the text. 

He also identified the species Acrfftreta subconica Kutorga (A. attenuata proposed if it proved to be a distinct species, p. 463), Hyolithes 

gregaria M. & H., Camerella calcifera Billings, and Agnostus josepha, 

Hall. Numerous generic references are made from the fragments in the 

collection, and in the lists from various localities species of the Calciferous zone of the Lower Silurian (Ordovician) occur, especially in the 

list of the collection from Malade City.6

1 Bull. Geol. Soo. America, vol. 2, 1891, p. 171.

"Preliminary notice of a remarkable new genusof Corals, probably typicalof anew family, * * * 

from the Silurian rocks of Nevada Territory. Am. Jour. Sci., 2d aer., vol. 45,1868, pp. 82-04.

3 Note on Ethmophyllum and Archaeocyathus. Am. Jour. Soi., 2d ser., vol. 46,1868, p. 144.

 "Meek, F. B.: Descriptions of fossils collected by the U. S. Geological Sarvey, under the charge of 

Clarence King, esq. Phil, Acad. Sci. Proo., vol. 22, 1870, pp. 62-64.

8 Note on the occurrence of the " Primordial Fauna " in Nevada. Am. Jour. Soi., 3d ser., vol. 3,1872, 

pp. 84,85. . 

6 Preliminary paleontological report, * * * with remarks on the agea of the rocks, etc. U. S.. 

Geol.Surv.of the Terr.,embracing portions of Montana, Idaho, Wyoming, and Utah; 6th Annual 

Report, 1873, pp. 463-487.
166 THE CAMBRIAN. [BULL.81.

From the collections made by the geologists of the Wheeler survey 

west of the one hundredth meridian, Dr. C. A. White describes, in a 

preliminary report, Cruzianalinnarssoni, G. rustica, Acrotreta 9 subsidua, 

Trematis pdnnulus, and Agnostus'interstricta. He also identified Hyolithes primordialis Hall ?; and published the manuscript description by 

Mr. Meek of Olenellus gilberti and 0. howelli.1 From the strata referred to the age of the Quebec group he describes Acrotreta pyxidicula (p. 9) and Dilceloceplialus flagricaudus (p. 12). The former species 

was subsequently identified by Mr. C. D. Walcott as Acrotreta gemma 

of the Upper Cambrian, and the latter species is referred to the Middle 

Cambrian fauna as Zacanthoides flagricaudus. The manuscript descriptions of Olenellus gilberti and 0. howelli by Mr. Meek were also printed 

in 1875 under the names of Olenus (Olenelhis) gilberti and 0. (0.) hoicelli 

in the report of Mr. Gr. K. Gilbert.2

The species described by Dr. White in his preliminary report of 1874 

were redescribed and illustrated by him in 1875. In addition to the 

species mentioned in the preliminary report he describes and illustrates 

Concoryplie (Ptychoparia) kingi Meek (p. 40) and Asaphiscus wheeleri 

Meek (p. 43.) 3

The two species described by Mr. Meek from Antelope Spring, Utah, 

in 1870, were redescribed and illustrated by him in 1877, under the 

names of Conocoryphe (Ptyclioparia) Mngi and Paradoxides ? nevadensis. 

In the description of the latter species he gave reasons for believing that 

the generic reference was incorrect, and that the species belonged to an 

undescribed genus. For this genus, if the species proved not to be 

Paradoxides, he proposed the genus Oleuoides.4

The description of the collections of the Fortieth Parallel Survey by 

Messrs. Hall and Whitfield added a large number of new forms to the 

Middle Cambrian fauna.5

The new species described are:

Obolella discoidea, p. 205. 

Lingulepia msera, p. 206.

? minuta, p. 206. « 

Kutorgina minutissima, p. 207. 

Lepttena melita, p. 208. 

Crepicephalns (Loganellus) haguei, p. 210.

(Loganellus) nitidus, p. 212.

(Loganellus) granulosus, p. 214.

(Loganellus) maculosus, p. 215.

1 Preliminary report upon invertebrate fossils collected by the expeditions of 1871, 1872, and 1873, 

with descriptions of new species, pp. 27. Geog. and G-eol. Sar. west of 100th Mer., Lieut. Wheeler 

in charge, Washington, 1874, pp4 4-12.

2 Report on the geology of portions of Nevada, Utah, California, and Arizona examined in the years 

1871 and 1872 Report on Geog. and Geol. Expl. and Sur. west of 100th Mer., vol. 3, Geology, 1875, pp. 

182,183.

'Report upou the invertebrate fossils collected in portions of Nevada,Utah, Colorado, New Mexico, 

and Arizona by parties of the expeditions of 1871-'74. Wheeler's Expl. and Sur. west of the 100th 

Mer., vol. 4, pt. 1, 1875.

«TJ. S. Geol. Expl. of the 40th Parallel, vol. 4, pt. 1,1877, pp. 20-25.

6 Ibid., vol. 4, 1877, pt. 2, pp. 205-246.
PALEONTOLOGY ROCKY MOUNTAINS.

Crepicepbalus (Loganellus) unisulcatus, p. 216.

(Loganellus) simulator, p. 218.

(Loganellus) anytus, p. 219.

(Batbyurua) ? flngulatus, p. 220. 

Couocepbalites (Pfcerocephalus) laticeps, p. 221, 

Ptychaspis pustulosa, p. 223. 

Chariocephalus tumifrons, p. 224. 

Dikelocepbalns bilobatus, p. 226.

multicinctus, p. 226.

flabellifer, p, 227. 

Agnostus communis, p. 228S

neon, p. 229.

prolongus, p. 230.

tumidosus, p. 231. ' 

Lingulepsis ella, p. 232. 

Couocephalites subcoronatus, p. 237. 

Crepicepbalus f (Loganellus) quadrans, p. 238. 

Dikelocephalus quadriceps, p. 240.

wasatchensis, p. 241.

t gotbicus, p. 242. 

Ogygia producta, p. 244.

parabola, p. 245.

Of these species those from Lingulepsis ella to Ogygia parabola, inclusive, are referred to the Quebec group, and the others to the Potsdam. The descriptions are accompanied by fine illustrations of all the 

species mentioned.

In 1880 Dr. 0. A. White referred his Acrotreta ? subsidua, described 

in 1874, to the genus Acrothele of Angelin.1

The study of a collection made l>y the U. S. Geological Survey from 

the Eureka district, Nevada, gave Mr. C. D. Walcott material for the 

description of a number of new species from the Cambrian. They 

include the following: 2

Acrotbele ? dicbotoma, p. 14. 

Scenella ? conula, p. 15. 

Kutorgina wbitfieldi, p. 18.

prospectensis, p. 19. 

Ortbis eurekensis, p. 22. 

Stenotbeca elongata, p. 23. 

Agnosfcus ricbmondensis, p. 24.

seclusus, p. 25. 

Oleuellns iddingsi, p. 28. 

Dikelocepbalus nasutus, p. 40.

ricbniondeusis, p. 41.

t angustifrons, p. 42.

iole, p. 43.

marica, p. 44.

? expansus, p. 45. 

Ptychoparia (?) prospectensis, p. 46.

(?) limiarssoni, p. 47-

' Note on Acrothele. TJ. S. Nat. Mus. Proc., vol. 3,1880. p. 47.

* Paleontology of the Eureka district. U. S. Geol. Surv., Monograph, vol. 8,1884, pp. 11-04.
168 THE CAMBRIAN. [BULL.61.

Ptychoparia (?) (Solenopleura) (I) breviceps, p. 49.

(?) pernasutus, p. 49.

(Euloiua?) dissimilis p. 51.

occidentalis, p 51. ©

similis, p. 52.

similis, var. robustus, p. 53.

(Euloma?) affinis, p. 54.

Iseviceps, p. 54.

(Pterocephalus) occidens, p. 58. 

Anomocare? parvuiu, p. 59. 

Agraulos ? globosns, p. 61. 

Arethiisina americana, p. 62. 

Ogygia? spinosa, p. 63.

(?) problematica, p. 63.

The following genera and species are mentioned and illustrated:

Protospongia fenestrata, p. 11. 

Lingulepis maera, p. 12.

fminnta, p. 13. 

Liugula ? manticula, p. 13. 

Obolella discoidea, H. & W., p. 14. 

Acrotreta gemma, Billings, p. 17.

Under this species are also included Acrotreta subconica and A. attenuata,

Meek, 1873, and Acrotreta pyxidicula, White, 1874. 

Kutorgina sculptilis, Meek, p. 20.

The synonymy of this species includes Iphidea (tt) eculptilie, 1873, and

Kutorgina minntissima, H. & W., 1877. 

Leptama melita, H. & W., p. 22. 

Hyolithes primordialis, Hall, p. 23. 

Agnostus bidens, Meek, p. 26. 

cominunis, H. & W., p. 27. 

neon, H. & W., p. 27. 

prolongus, H. & W., p. 28. 

Olenellus gilberti, Meek, p. 29.

howelli, Meek, p. 30.

Dikelocephalus bilobatus, H. & W., p. 40. 

osceola, Hall, p. 40. 

? quadriceps, H. & W., p. 45. 

Ptychoparia oweni, M. &H., p. 55.

Under this species are placed as synonyms ConocorypTie (Ptyohoparia') 

gallatinensw, Meek, 1873, Crepicephalus (Loganellus) centralis, Whitfield, 1877.

anytus, H. & W., p. 56.

granulosus, P. haguei and P. nitidus, H. & W., p. 57. 

Under the latter species CrepicepTialns (Loganellua) simulator, H. &

W., 1877, is placed as a synonym, 

unisnlcatus, H. & W., p. 38. 

^ (Pterocephalus) laticeps, H. & W., p. 59. 

Ptychaspis miuuta, Whitfield (?) p. 60. 

Chariocephalus (?) tumifrons, H. & W., p. 61.

Notes on the genus Acrotreta of Kutorga are given on page 16 j and 

observations on Olenellus howelli on pages 32-39.
PALEONTOLOGY KOOKY MOUNTAINS. 169

In 1886 Mr. 0. D. Walcott reviewed the species which he then considered to belong to the Oleuellus, or Middle Cambrian fauna.1 

The following new species were described from Utah and Nevada:

Eocystites ?? longidactylus, p. 94. 

Orthis ? highlandeusis, p. 119. 

Hyolitbes billingsi, p. 134. 

Leperditia ? argenta, p. 146. 

Olenoides typicalis, p. 183.

levis, p. 187. , 

Ptychoparia housensis, p. 201.

piochensis, p. 201. 

Crepicephalus liliana, p. 207. .~°

augnsta. p. 208.

Orytcocephalus, new genus, p. 210. 

Orytcocephalus primus, p. 210. 

0 Bathyuriscus howelli, p. 216.

The genus Ethmophyllum, described by Mr. Meek in 1868, and the 

species placed under it referred in the same year to Archaeocyathus, is 

redefined as the genus Ethmophyllura, with Etlimopliyllum whitneyi as 

the type (p. 81.) Etlimopliyllum gracile Meek is placed as a synonym of 

the latter species. Descriptions and illustrations of the following 

species also appear in this work:

Protospongia fenestrata, Salter, p. 90. 

Lingnlella ella, H. & W. p. 97. 

Acrotreta gemma, Billings, p. 98. 

Kutorgina pannula, White, p. 105. 

prospeotensis, Walcott, p. 106. 

Acrothele subsidua. White, p. 108. 

Scenella ? conula, Walcott, p. 127. 

Stenotheca ? elongata, Walcott, p. 129. 

Agnostus interstrictns, White-, p. 149. 

Olenellus iddingsi, Walcott, p. 170.

gilberti, Meek, p. 170. 

Olenoides nevadensis, Meek, p. 181. 

epinosus, Walcott, p. 184. 

t flagricaudns, White, p. 185. 

quadriceps, H. & W., p. 187. 

wasatchensis, H. & W.,p. 189. ' 

Ptychoparia kingi, Meek (sp.), p. 193. 

quadrans, H. & W., p. 1997 

f prospectensis, Walcott, p. 202. 

subcorouata, H. & W.,p.205. 

Anomocare ? parvum, Walcott, p. 209. 

Bathyuriscus producing, H. & W., p. 217. 

Asaphiscus wheeleri, Meek, p. 220.

A discussion of several of the genera is also presented.

In a paper on the stratigraphic position of the Olenellus fauna Mr. 

0. D. Walcott reviewed the stratigraphic position of the fauna described iu Bulletin 30 of the U. S. Geological Survey, and referred the

1 Second contribution to the studies of the Cambrian faunas of North America. U. S. Gaol. Survey. 

Bull. No. 30, 1886.
170 THE CAMBRIAN. [BULL.81.

following species, formerly assigned to the Lower Cambrian fauna, to 

the Middle Cambrian zone, considering the Olenellus zone to include 

only the Lower Cambrian fauna.1 The species are:

Protospongia fenestrata, Salter. 

Eocystites?? longidactylua, Walcott. 

Leperdifcia argenta, Walcott. 

Agnostus interstrictus, White. 

Olenoides nevadensis, Meek (sp.).

quadriceps, Hall & Whitfield (sp.). 

wasatchensis, H. & W. (sp.).

spinosus, Walcott.

typicalis, Walcott. 

Ptyclioparia housensis, Walcott.

kingi, Meek (sp.).

piochensis, Walcott. 

fprospectensis, Walcott.

qnadraus, H. & W. (sp.).

eubcoronata, H. & W. (sp.). 

Bathyimscufl howelli, Walcott.

productus, H. & W. (sp.). 

Asapliisctis wheeleri, Meek.

Ptychaspis piochensis occurs 100 feet above the Olenellus zone proper, 

in the Highland range section, but as it also occurs 1,137 feet higher 

up in the same section, it is now referred to the Middle Cambrian fauna 

and not to the Olenellus fauna.2

The presence of Cambrian fossils at Kicking Horse Pass of the Eocky 

Mountain division of the Canadian Pacific Railway was announced by 

Mr. H. H. Winwood in 1885.3 Indirect reference was also made to this 

by Dr. Gr. M. Dawson in 1884.4 The specimens obtained at that time 

were examined by Mr. 0. D. Walcott, who recognized Olenellus hoicelli 

and Olenoides levis, trilobites characteristic of the Prospect Mountain 

group of Nevada.5

During the survey by Mr. R. GT. McConnell of the section along the 

line of the Canadian Pacific Railway there was discovered at Mount Stephen a zone of fossiliferous slate 2.000 feet above the base of the Castle 

Mountain limestone. From the collections obtained Dr. C. Koininger 

described the new genus Embolimus and five new species of trilobites, viz: Ogygia Motzi, 0. serrata, Embolimus spinosa, E. rotundata, 

and Gonocephalites cordillerce. He also identified Mtnoceplialus salteri ?, 

Billings, BathyurusP, Agnostus ("compare A. interger Barr"), and the 

genera Orthis, Obolella, Kutorgina, Leptaena?, Metoptoina, and Hyolithes.6

1 Stratigraphic succession of the Olenellus fauna in North America and Europe. Am. Jour. Sci., 

3d ser., vol. 37, pp. 374-392; vol. 38,1889, pp. 29-42.

2 Op. cit., p. 387.

1 Geological age of the Rocky Mountains. Geol. Magazine, new ser., dec. 3, vol. 2,1885, p. 240.

* Hecent geological observations on the Canadian Northwest Territory. Scie nee, vol. 3,1884, p. 648. 

6 Preliminary report on the physical and geological features of that portion of the Rocky Mountains 

between latitudes 49° and 51° 30'. GeoL Surv. Canada, new ser., vol. 1,188t5, p. 140B.

 Description of Primordial fossils from Mount Stephen, Northwest Territory of Canada. Philadelphia Acad. Sci., Proc., 1887, pp. 12-19.
 VTAtCOTt.J WISCONSIN. 171

A review of Dr. Eominger's work on the Mount Stephen fossils by Mr. 

C. D.Walcott resulted in his determining that Embolimuft spinosa,J&om.= 

Zacanthoidesspinosus, Walcott; Embolimus rotundata, Hom.=I>atliyuriscus howelli, Walcott; Ogygiaserrata=0lenoides nevadensis, Meek; and 

that Conoceplialites cordillerce, ~Rom.=Ptychoparia cordillerce, Rom. 

(sp.), and Ogygia ? ? Uotzi, Bora., are new to the previously known 

Cambrian fauna. The genus Zacanthoides is proposed to include Olenoides typicalis, O.spinosus, 0. levis, and O.flagricaudus, described in 1886. 

There were also identified from the material studied by Dr. Eominger 

Agnostus interstrictus, Acrotreta gemma, Kutorgina prospectensu, and 

Hyolithellus micans.1 Subsequently from the collection studied by Dr. 

Eomiuger there were described by Mr. Walcott, Lingulella macconelli 

Crania ? columbiana, Acrotreta gemma var. depressa, Orthisina alberta, 

Platyceras romingeri, Karlia stephenensis, Bathyurisous (Kootenia) 

dawsoni, and the genus Ogygopsis was proposed to include the Ogygia 

Uotzi of Eominger. Linnarssonia sagittalis was also identified.2

In 1890 Mr. C. D. Walcott 3 described three new species from the 

Highland range section of Central Nevada, referring them to the Upper 

Cambrian. These species are Hyolithes attenuatus, H. curvatus, and JET. 

(?) corrugatus.

INTERIOR CONTINENTAL, PROVINCE.

This province includes the Upper Mississippi area, the eastern border 

or Adirondack subprovince, the western border or Eocky Mountain 

subprovince, and the Llano County area of central Texas and the 

Grand Cafion of Arizona as a minor southwestern subprovince.

UPPER MISSISSIPPI AREA.

For convenience of reference the review of the literature pertaining 

to Wisconsin, Minnesota, and Iowa is assembled for each State. The 

Ozark area of southeastern Missouri is considered separately, and the 

Lake Superior sandstones and the controversy in relation to them is 

noticed under a distinct heading, after the description of the recognized 

Upper Cambrian rocks of Wisconsin, Iowa, and Minnesota, and their 

extension into Canada. This division also includes the references to 

the Cambrian rocks of Michigan.

WISCONSIN.

In 1843, in notes on the geology of the Western States, Dr. D. D. 

Owen called attention to the presence of a sandstone on the Mississippi 

Eiver, at Prairie du Chien, visible beneath the Lower Magnesian lime1 Cambrian fossils from Mount Stephens. Am. Jour. Sci., 3d ser., vol. 36,1888, p. 165. 

*.Descriptions of new genera and species of fossils from the Middle Cambrian. U. S. National 

Museum, Proc., vol. 11,1889, pp. 441-446. 

1 Description of new forms of Upper Cambrian fossils. U. S. Nat. Mas. Proo., vol. 13,1890, pp. 267-279.
172 THE CAMBRIAN. . [BUM..81.

stone of the "Wisconsin Kiver.1 Five years later, in the report of a 

geological reconnaissance of the Chippewa land district of Wisconsin, 

he describes with considerable detail Formation 1, or the lower sandstone of the Upper Mississippi. The formation, as a whole, is subdivided into five parts. The lowest part rests upon crystalline and 

metamorphic roeks, in the eastern part of the Chippewa land district, 

as a coarse sandstone overlaid by a still coarser quartzose sandstone.2 

At the Falls of the St. Croix the schistose, silico-calcareous layers of 

the second division are highly fossiliferous. In the third division the 

prevailing genera are Lingula and Orbicula3 and it is designated as 

the "Liugula sandstone." In speaking of the beds of sandstone 

beneath the fossiliferous layers at Mountain Island it is stated that in 

all probability this.is the western equivalent of the Lingula beds of the 

New York Potsdam sandstone.4

A notice of the discovery of the fauna in the lower sandstone of Wisconsin was communicated by Dr. Owen in 1848 to the Geological Society of France through a letter to M.- de Verneuil.5

In a letter descriptive of the geology of southeastern Wisconsin addressed to Mr. J. W. Foster, Mr. I. A. Lapham states that 

The Inferior, or Potsdam sandstone, is found at Janesville and above, occupying the 

bed of the river. The grains are rounded, smooth, and without apparent cement; 

the rock easily crumbles upon exposure; color white or red. The white variety 

might be used for the manufacture of glass. The discovery, in 1849, of that singular 

and characteristic fossil described by Mr. Hall as Scolithus linearis (New York Pal., 

vol. 1, p. 2) in this rock, in Sauk County, may be considered as settling the question 

of the identity of this rock with the Potsdam sandstone of the New York reports. It 

occupies much of the counties Marquette and Columbia, enters Dane County, and is 

seen in the banks of Rock River from Lake Koshkonoug to Janesville.

* * * H. Caloiferous rock of Eaton. Resting immediately upon the sandstone, 

at Janesville, is a limestone with grains of the same sand intermixed, giving it the 

form and appearance of an oolite limestone ; the amount of sand diminishing as you 

rise from the surface of the sandstone. It accords exactly with the description given 

of a portion of the calciferous sandstone of New York, and contains the same fucoid 

(Palceopliycus tubnlaris), as well as other characteristic fossils. Its character and relative position also clearly show that it is the same rock that, farther west and north, 

is called the Lower Magnesian limestone, by Drs. Owen and Locke.*

In the same report, Mr. Charles Whittlesey describes the sandstone as 

it occurs near Wolf Eiver, etc., stating it to be a sandstone easily 

crushed between the fingers, which has been so extensively denuded 

that it is only here and there that a trace of its former existence is

1 On the geology of the Western States. Am. Jour. Sci,, vol. 45, 1843, p. 164.

2 Owen, David Dale: Report of a geological reconnaissance of the Chippewa land district of Wisconsin, and incidentally of a portion of * * * Iowa and of the Minnesota territory. Letter of the 

Secretary of the Treasury communicating a report of a geological reconnaissance of tho Chippewa 

land district of Wisconsin, etc., by D. D. Owen, Thirtieth Congress, first session, Senate Ex. Doc. No. 

57,1848, p. 1.3.

3 Op. cit.,p.!4.

4 Op. cit., p. 15.

6 Letter on geology of Wisconsin Territory. Bull. Soo. g6ol. France, 2° ser., vol. 5,1848, pp. 294-296.

6 Lapham, I. A.: "On the geology of the southeastern portion of the State of Wisconsin, being the 

part not surveyed by United States geologists." Kept, on the geology of the Lake Superior land district, by Foster and Whitney, part 2,1851, p. 16D.
WALCOTT.J WISCONSIN. 173

left.1 On the Upper Menomonee River the sandstone has a thickness 

of 150 feet, and the entire thickness is estimated at 200 feet. 2

In giving an account of his investigations in connection with the 

geological survey under the direction of Messrs. Foster and Whitney, 

Prof. J. Hall states:

I have also satisfied myself that the sandstones of the Upper Mississippi are of the 

same age as the Potsdam sandstones, and that the Lower Magnesian limestone of the 

Western geologists is identical with the calciferous sandstone of New York, the next 

member of the series above the Potsdam sandstone. The thin bed of sandstone succeeding this rock can not be identified as the Potsdam sandstone by itself, but must 

be regarded as a repetition of the arenaceous deposits below, which likewise alternate with the calciferous sandstone near its base.3

He thus corroborates the view of Dr. D. D. Owen that the lower sandstone of Wisconsin is the equivalent of the Xew York Potsdam.

In 1851 M. E. Desor called attention to the presence at St. Oroix of 

a tossiliferous sandstone 800 feet beneath that described by Professor 

Hall, in which he found fossils.4

In a paper on the paleontology of the lowest sandstone of the northwest Dr. D. D. Owen states that he observed multitudes of Lingulas 

and Orbiculas disseminated in strata abutting against the southwest 

side of the trap range that crosses the St. Groix River at the falls. 

This was in 1847. During the remainder of this season and in that of 

1848 he found finer-grained and more laminated soft sandstones, with 

subordinated silico-calcareous layers, charged with Obolus, like those 

which characterize the lowest sandstones of Kussia. This was in a 

section on the Mississippi, between the Falls of St. Anthony and the 

mouth Of the Wisconsin River. From the results of these observations 

he finally developed beneath the Lower Magnesian limestone at least 

six different trilobite beds, separated by from 10 to 150 feet of intervening 

strata.5

In the final report on the geology of the Upper Mississippi Valley, the 

same writer describes the lower sandstone as composed of light-colored 

quartzose sandstone that forms the greater part of the formation, with 

intercalations of magnesian limestone, especially toward its upper part, 

where it graduates into Formation No. 2, and at certain localities argillaceous, and other beds of a mixed character form a considerable portion of its lower mass.6 In a table of the elementary stratification of 

the lowest Protozoic sandstones he places the Lake Superior ferrugi1 Remarks upon the section from the falls of Wolf River, through Navarino to Lake Michigan. 

Kept, on the geology of the Lake Superior land district, by Foster and Whitney, part 2,1851, p. 174.

2 Whittlesey, Charles: The dip, bearing, and thickness of the Silurian groups. Kept, on the geology 

of the Lake Superior land district, by Foster aud Whitney, part 2,1851, p. 183.

3 (Geological investigations on Drummond's Island aud the north shores of Lakes Huron and Michigan, etc.) Am. Acad. Proo., vol. 2,1851, p. 254.

4 1Potsdam sandstone on the river St. Croix.J Boston Soo.Nat. Hist.Proc., vol.3,1851,p.202.

6 On the paleontology of the lowest sandstones of the Northwest. Ana. Assoo. Proc., vol.5, 1851 

pp. 169-172. '

6 Geoil. Surv. of Wisconsin, Iowa, and Minnesota., and incidentally of a portion of Nebraska Territory, 

Philadelphia, 1852, p. 48.
174 THE CAMBRIAN. [BULL. 81.

nous and argillaceous sandstones, shales, and conglomerates at the base, 

assigning it a thickness of 5,000 feet. Above this occur coarse grits and 

sandstones of the Chippewa, Black and Wisconsin Rivers.1 The placing 

of the lower sandstone of Lake Superior in this position is theoretical. 

Above the coarse sandstone the formation is divided into six trilobite 

beds, as follows: 2 

Table of the elementary stratification of the lowest Protozoic sandstones. 

Formation 1.

Feet.

f Quartzose, light-colored sandstones of various 

degrees of induration, with intercalations of 

I beds of uiagnesiau limestone, with glistenSixth Trilobite bed, . \ ing crystalline facets, and calcareo-siliceoua U1A.VU. J.HWIUUO uou,..^ oolite,produced by rounded gramsof quartz, 

/. < encased in calcareous cement, containing

Euomphalas and imperfect Trilobites. Loi. cally with a baud of green earth .......... 50to 85

Mammillary and botryoidal layer of white 

sandstone; sometimes banded with yellow.. ................. ......5to 6 inches.

J Thick beds of soft, yellowish and brown sandstone, sometimes with botryoidal, hard, projecting concretions passing downward into 

I fine-grained soft sandstones approaching 

t tripoli ...... ............................. 40 to 50

( Ash-colored and yellowish argillo-calcarepus 

v>n/i \ an<i magnesio-calcareons beds, containing 

bed... <^ Dilceloceplialm minnesotensis.

(StillwaterTrilobite bed..................... 8to 10

Green,red,and yellowish sandstones with thin, 

schistose, dolomitic intercalations ........ 40

Upper, brown dolomitic layers containing 

Orthis, Lingulas, and columns of Crinoidea 

as at La Grange Mountain................ 4

( Alternations of yellow, laminated sandstones, 

Fourth Trilobite bed.. < with green particles disseminated.......... 5

( Marine Mill Trilobite grit.................. 5

Fucoidal layers, and thin-bedded green and 

yellow sandstones, at their base often a 

band of about 6 inches of green earth used 

by the Indians as a pigment .............. 30 to 40

Green and red sandstones, charged with silid. < cateof iron............................... 5

Loose, green sand, and soft green sandstone... .................................. 15

C Micaceous sandstone, containing DikeloI cephalus menislcaensis, D. granulosa, etc .... 3

Third Trilobite bed ^ Alternations of green and ferruginous sand-

"" I stones.................................... 20

Micaceous sandstones containing D. menis- 

^ kaensis, etc ............................... 2

Thin layers of green sand, alternating with 

green earth, impregnated with silicate of 

iron...................................... 30to 40

Lower, brown siliceo-calcareous and dolomitic bands of Mountain Island, and elsewhere ................................... 4

Soft, thin-bedded sandstones, with scales of 

mica disseminated'........................ 10to 15

c............. .. .._ ....... .Coarse lingula grit, green, yellow, sometimes

almost white............................. 100 to 130

1 Op. cit., p. 53. * Op. cit., pp. 52, 53.
WALCOTT.J WISCONSIN. 175

Table of the elementary stratification of the Lowest Protozoic sandstones,

etc. Continued.

Feet.

f ( Fine grit. Place of the Menoinonie Trilobite 

Second Trilobite bed.. < grit (T). White and yellow sandstone, and

( Obolus layers of Black River ............. 15

C Ferruginous Trilobite grits. Schistose sandstone, containing fork-tailed Trilobite beds 

, First Trilobite bed ....{ and Obolus layers ........................ 1 to 8

6. ^ j Magnesio-calcareous rock, with Obolus and

^ fork-tailed Trilobite ...................... 3

Highly fossiliferous schistose, siliceo-calcareouslayers, in terlaminated with argillaceous, 

marly beds, charged with sulphate of iron; 

the former full of Lingulas and Orbiculas 

(Fallsof St. Croix)....................... 50

f Sandstone, with oblique lines of deposition, 

alternating with pebbly sandstones and 

I coarse grits of the Chippewa and Black aud 

a....... .................. ^ Wisconsin Rivers near tbe falls ........... 50 to 100

I Place of the Lake Superior ferruginous and 

I argillaceous sandstones, shales, and con- 

(. glomerates ............................... 5,000

The geographic distribution of the formation is shown on the map 

accomp*auyiug the report.

The local details of the sections in Wisconsin are reported upon by 

Prof. B. F. Shumard. Much of the information here given was used 

by I)r. (Jwen in giving the summary of the divisions referred to Formation No. 1, or the lower sandstone.1

The sandstones of the south shore of Lake Superior are described by 

Mr. J. C. Norwood, and a section given of them as seen at the mouth of 

Cranberry River. He also describes the sandstones of the St. Croix 

River.2

In his annual report of the geological survey of the State of Wisconsin Prof. J. G-. Percival describes the lower sandstone with considerable detail, but without special addition to the information given by 

Dr. Owen. He separates, however, the quartz rock of the Baraboo 

and of Portland from the Lower sandstone.3

The volume of the geological survey of Wisconsin, by Prof. James 

Hall, contains a general account of the Potsdam sandstone. The opening paragraph describes it as follows:

The lowest rock of the series is the Potsdam sandstone, which is known in the northwest as the Lower sandstone, in contradistinction to the Upper or St. Peter's sandstone, which lies above the Lower Magnesian limestone. This is equivalent to the 

Potsdam sandstone in New York, and holds in all respects the same geological position: 

it is the lowest fossiliferous rock observed in the geological surveys of New York, 

where it received its name.

This rock has been traced, with slight interruptions, westward from Lake Charn1 Geol. Eeport of local, detailed observations in the valleys of the Minnesota, Mississippi, and Wisconsin Elvers. Eeport of a geological survey of Wisconsin, Iowa, and Minnesota; and incidentally of 

a portion of Nebraska Territory. Philadelphia, 1852, pp. 475-031.

* Geol. Eeport of a survey of portions of Wisconsin, and Minnesota. Eep. Geol. Surv. of Wisconsin, 

Iowa, and Minnesota; and incidentally of a portion of Nebraska Territory. Philadelphia, 1852, pp. 

275-277.

 Anauftl Eeport of the Geological Survey of the State of WUoonsin. Madiaon, 1856, pp. 92-10L
176 THE CAMBRIAN. [BULL. 81.

plain through Canada to the outlet of Lake Superior and along the south shore of 

that lake. 1

This is followed by a general account of the formation and of the organic remains found in it.2

In the same volume Prof. J. D. Whitney prints a brief re'sume' of the 

Potsdam or lower sandstone.3

In a paper entitled "Preliminary notice of the fauna of the Potsdam 

sandstone," Prof. James Hall states that in 1850 he had the opportunity 

of tracing the formations from Drummond's Island and St. Mary's Kiver 

to the head of Green Bay and thence across the country to the Mississippi Eiver.4 He comes to this conclusion:

The position of the sandstone on the St. Mary's admitted of no doubt, and its relative position to the lower limestone had before that time been well determined, and 

the same was likewise ascertained by the several exploring parties along different 

lines between Lake Superior and Green Bay. 

Throughout Wisconsin there is no difficulty in recognizing the following sequence:

Trenton limestone;

Black Eiver or Buff limestone;

Birdseye limestone;

St. Peter's sandstone;

Lower Magnesian limestone, or calciferous sandstone;

Potsdam sandstone.

The St. Peter's sandstone holds the place of the Chazy limestone of the more 

eastern localities, and, with this exception, we have the same sequence that we find 

in New York, many of the fossils being common to the limestone of New York and 

Wisconsin.

Dr. Owen, in his published report, has adopted this view of the sequence, and the 

explorations of subsequent years have confirmed the opinions then entertained; and 

I believe at this time every geologist will admit the identity of the Potsdam sandstone of New York and the Lower sandstone of the Upper Mississippi Valley.

In speaking of this sandstone I shall, therefore, without hesitation, refer to it as 

the Potsdam sandstone. 5

A list of fossils described in the memoir is given to illustrate their 

stratigraphic position.6 In this list the fauna is divided into that of 

the lower beds, middle beds, and upper beds, the latter characterized 

especially by the presence of the genus Dikelocephalns. In a supplementary note on the Potsdam sandstone that accompanies the memoir 

he gives a re'sume' of the evidence upon which the lower sandstone of 

the Upper Mississippi Valley has been placed in parallelism with the 

sandstone of New York, known as the Potsdam sandstone, as follows: 7

In comparing the older rocks of New York and of the East generally with those of 

the West, it should not be forgotten that there is a long interval on the line of the

1 Physical geography and general geology. Geol. Surv. Wisconsin, Report, vol. 1,1862, p. 14.

a Op. cit, pp. 20-23.

»Stratigraphical geology. Geol. Surv. Wisconsin, Rep., vol. ], 3862, pp. 140-144.

Preliminary notice of the fauna of the Potsdam sandstone, with remarks on the previously known 

species of fossils and descriptions of some new ones from the sandstone of the Upper Mississippi Valley. 16th Ann. Rep. Regents Univ. U. Y., State Cab. Nat. Hist, 1863, pp. 119,120.

8 Op. cit., p. 120.

« Op. cit, p. 209.

'Op. cit, pp. 211-213.
WALCOTT.] WISCONSIN. 177

northern outcrop of these ancient strata, between the St. Lawrence and the western 

limit of Michigan on the Menomouee Kiver, where we can expect little aid from 

paleontology. The fossiliferous beds of these ancient formations in Wisconsin lie to 

the west of what appears to have been a great promontory at the time of their 

deposition, stretching southward from the region of Lake Superior far into the 

ancient sea. The disconnection caused by this promontory between the East and 

the West would of itself prepare us to expect a fauna differing in a great degree 

from beds of corresponding age on the opposite sides.

It has been shown, by the investigations of the Canadian Survey, that not only the 

Potsdam sandstone, but all the fossiliferous beds below the Birdseye and Black River 

limestones are absent from Kingston on Lake Ontario to Lacloche on Lake Huron. 

From Lacloche to Lake Superior there is a sandstone coming in below the Birdseye 

limestone, which, from its position, may be considered of the age of the Chazy1 formation and equivalent to the St. Peters sandstone of Wisconsin and Minnesota; and 

it is this sandstone, doubtless, which has been taken for the Potsdam sandstone in 

some localities along that line.

The succeeding Birdseye and Black River formation, from Lacloche to Lake Superior, has become a buff-colored ntagnesian limestone, or weathering externally to 

this color, but still holding the characteristic fossils.

In New York a sandstone (the Potsdam) lies immediately beneath a magnesian 

limestone (the " Calciferous sandrock "): this deposit is succeeded by a calcareous 

formation (the Chazy), including a sandstone and surmounted by the Birdseye, Black 

River, and Trenton limestones.

In Wisconsin, Iowa, and Minnesota, we have undoubted Trenton limestone, and 

below it a buff-colored magnesian limestone containing so many of the characteristic 

fossils of the Birdseye and Black River limestones as to leave no doubt of the parallelism of these beds with those of New York. Below this magnesian limestone we 

have the St. Peters sandstone, corresponding, as already shown, with the Chazy formation; and beneath this a magnesian limestone, which, in its position and lithological character, corresponds in all respects with the " Calciferous sandrock" of New 

York.

It is from all these facts that the lower sandstone of the Upper Mississippi Valley 

has been placed in parallelism with the sandstone of New York known as the "Potsdam."

Notwithstanding, however, that this sequence is precisely like that observed in New 

York, it may not yet be regarded as proved that the sandstone, from which I have 

described these fossils, is in all respects the equivalent of the Potsdam sandstone of 

New York, Vermont, and Canada. It may represent more, or it may represent less 

than that formation. The lower accessible beds of the Mississippi Valley may represent the Potsdam of 150 or 200 feet in thickness in the typical localities in New York, 

while the middle and upper beds of the West may be of epochs not represented in 

that part of the series studied in New York; and in some other places, as in the regions just mentioned, the same epochs may be represented by a shaly or semi calcareous deposition, or may be included in the commencement of the Calciferous epoch. 

It should not therefore be regarded as decided that the Potsdam sandstone, as developed in New York, occupies the entire interval from the base of the oldest sedimentary formation of the Paleozic era to the Calciferous sandstone. From what we 

know of the primordial fauna in other localities, we are prepared to find beds above 

or below, or both above and below, the epoch represented (so far as now known) by 

the Potsdam sandstone of New York, and which may still be of the same period.

'The "Chazy formation" of the Canadian Geological Survey,in its eastern localities, includes a 

sandstone which comes in below the greater part of the limestone, leaving from 10 to 20 feet of 

bhale and limestone beneath (Geology of Canada, 1863, p. 123^. It as apparently this sandstone of the 

Cbazy formation, having in Canada a thickness of 50 feet, which has become augmented in its western extension, while the calcareous part of the formation has partially or entirely disappeared.

Bull. 81 12
178 THE CAMBRIAN. [BULL.81.

He then enters upon the discussion of the relative age of the sandstones of Wisconsin and those of Lake Superior, and concludes that 

while the older beds of the latter, area are apparently below the fossiliferous beds of the Upper Mississippi Valley, the newer sandstone of 

the St. Mary's River, which is apparently of the age of the St. Peter 

sandstone, or the Chazy formation, will be found overlying the fossiliferous sandstone, either with or without the intervention of the Lower 

Magnesian. li inestone.1

On a geological map of Wisconsin published in 1855 Mr. I. A. Lapham 

delineates the distribution of a sandstone occurring beneath the Lower 

Magnesian limestone. Under the same color he includes the sandstone 

on the south shore of Lake Superior, both on the north and southeastern 

side of the trap rocks of Keweenaw Point. The distribution of the 

fossiliferous sandstone south and southeast and east of the northern 

area of the primitive rocks is also laid down.2 In a new geological 

map of Wisconsin, published in 1869, only the sandstones of the northwestern portion of the State are colored as Potsdam sandstone. In the 

vicinity of the shores of Lake Superior the Michigan area on the map of 

1855 is left uncolored.

A paper on the age of the quartzites, schists, and conglomerates of 

Sauk County, Wisconsin, by Prof. E. D. Irving, proves conclusively 

that the quartzites are of pre-Potsdam age, and that the latter are deposited unconformably upon the flanks of the hill formed by the quartzites.3 The evidence given by Prof. Irving negatives the conclusion arrived at by Dr. Alexander Winchell in his description of the fossils of 

Sauk County, where he states that Ptychaspis and Dikelocephalus 

occur at the base of the Potsdam, and that the quartzites in question 

are the lower beds of the Potsdam formation.4 In the region of southcentral Wisconsin, especially in Dane and Columbia Counties, Prof. 

Irving obtained a thickness of 800 feet for the lower or Potsdam sandstone, and for the superjacent Mendota limestone 30 feet, above which 

occurs the Madison sandstone, with a thickness of 35 feet. He refers 

only the lower or Potsdam sandstone to the Primordial.5

The sketch on the geology of northern Wisconsin by Mr. B. T. Sweet 

gives a general description of the Potsdam sandstone, and attention is 

called to the fact that all the strata at the falls of St. Croix belong to 

this sandstone formation and that none of them are of igneous origin, 

as suggested by Dr. Owen.6

»0p. cit., p. 220.

2 Lapham, I. A.: Geological Map of Wisconsin. Milwaukee, 1856. Also a map for 1869.

3 On the age of the quartzites, schists, and conglomerates of Sank County, Wisconsin. Am. Jour. 

Sci., 3d ser., vol. 3, 1872, pp. 95-99. Wise. Acad. Sci. Trans., vol. 1,1«72, pp. 129-137.

4 Notice of a small collection of fossils from the Potsdam sandstone of Wisconsin and the Lake 

Superior sandstone of Michigan. Am. Jour. Sci., 2d ser., vol. 37,1864, pp. 226-232.

5 Note on some new points in the elementary stratification of the Primordial and Canadian rocks of 

BOnth-central Wisconsin. Am. Jour. Sci., 3d ser., vol. 9,1875, pp. 441,443. 

'Notes on the geology of northern Wisconsin. Wise. Acad. Sci. Trans., vol. 3,1876, p. 61.
WALCOTT.l WISCONSIN. 179

A note on the age of the Crystalline rocks of Wisconsin by Prof. Irviug 

states that the exact junction between the Potsdam and the Huronian 

formations is often to be seen, the almost loose sand of the Potsdam, 

with numerous fossils, together with fragments derived from the 

older rocks, lying upon and wedged in between the tilted edges of 

Huronian quartzite, schist, or other rock. Exactly similar uuconformability is to be seen'at the Dalles of the St. Croix River between the 

Potsdam arid copper-bearing series; the horizontal beds of the former, 

filled with shells of Lingulella, lying directly upon the columar, melaphyre(f) of the latter series, the exact junction of the two series being 

exposed.1

The description of the geology of eastern Wisconsin by Prof. T. 0. 

Chamberlin contains a detailed account of the " Potsdam sandstone." 

He says:

That it is the exact equivalent of the Potsdam sandstone of Now York, as would 

seem to be implied by the name, is nofc absolutely certain, brft as the term has been 

used to designate this formation in previous reports upon the geology of the State, 

and as the weight of evidence and authority favors this view, tLe name Potsdam 

sandstone will be used without further qualification in this report."5

The sandstone varies greatly in thickness, ranging from zero to about 

1,000 feet. A detailed account of the formation is given with a list of 

the fossils found in the sandstone. The Madison sandstone and Mendota limestone are included as subdivisions of the terrane.

Reference to the description of the Lower or " Potsdam " sandstone 

series of central Wisconsin by Prof. E. D. Irving,3 will be made under 

the description of the Potsdam terraue in Wisconsin.

A general description of the mode of occurrence and character of the 

Potsdam sandstone in the lead regions of northwestern Wisconsin was 

published by Mr. Moses Strong in 1877.4

Upon the basis of work in St. Croix, Dunn, and adjacent counties, 

Mr. L. C. Woostersubdivided the "Potsdam" as follows: 5

The numbers indicate the distances below the Lower Magnesian limestone. 

(a} Upper calcareous band: This varies greatly in thickness, and is the probable 

northwestern equivalent of the Mendota limestone near Madison; 75 to 85 feet.

(b) Lower calcareous band: The limestone characters and the thickness are more 

uniformly persistent than in a; 145 to 195 feet.

(c) Hudson trilobite beds: Quite rich in trilobites and brachiopods, including one 

new species of the former, with several undetermined ones; 150 to 200 feet.

(d) Glauconite layers: These comprise those layers which are very rich in glauconite. Crinoid stems were found in these at Hudson; 160 to 210 feet.

In &, o, and d, the lesser distance from the Lower Magnesian is true for western St. 

Croix County, while the greater is nearer true for points east.

'Note on the age of the Crystalline rocks of Wisconsin. Am. Jour. Sci., 3d ser., vol. 13, 1877, p. 

308.

2 (Geology of eastern Wisconsin.) Geol. Wise., Surv. of 1873-77, vol. 2,1877, p. 257.

3 (Geology of central Wisconsin.) Geol. Wise., Surv. of 1873-77, vol. 2, 1877, pp. 525-607.

«Geol. Wise. Surv. of, 1873-'77, vol. 2,1877, pp. 668-688.

6 Work in St Croix, Dunn, and adjacent counties. Geol. Surv. Wisconsin, Ann. Rep. for 1877,1878 

pp. 36,37.
180 THE CAMBRIAN. tBULL.81.

(e) Eau Claire trilobite beds: These hold at least seven species of trilobites, of 

which three are new, and a few hrachiopods. These beds mark the lower limit of 

calcareous matter in the formation; 450 feet.

(/) Eau Claire grit: These layers mark the upper limit of the coarse sandstones, 

almost conglomerates; 680 feet.

The mode of occurrence and character of the " Potsdam" sandstone 

in the upper St. Oroix district is described in great detail by Mr. Moses 

Strong.1 In this he shows the unconformity between the " Potsdam n 

and the subjacent strata referred to the Keweenawan (Keweenaw) 

series, and describes the various sections of the sandstone exposed. 

The knowledge of the local details of the distribution and character of 

the "Potsdam" sandstone of the Mississippi region north of the Wisconsin Eiver was increased by him in 1882 by the publication of many 

sections and descriptive details that will be used in a summary of our 

knowledge of the Cambrian rocks of that region.2

The a Potsdam" terrane of the lower St. Oroix district was described 

by Mr0 L. C. Wooster in the same volume with the report of Mr. Strong. 

This report also contains considerable data that will be referred to in 

the description of the Cambrian rocks of the region.3

The geographic distribution of the " Potsdam" sandstone and its relation to the subjacent pre-Cambrian rocks and the super]aceutmagnesian limestone is shown with great accuracy upon the general geological map of Wisconsin, published in 1881, and in the two sections at the 

bottom of the sheet.

A note by A. A. Young on the crystallized sands of the u Potsdam " 

sandstone of Wisconsin describes the manner in which the original 

grains of the sandstone are surrounded, by crystalline envelopes of 

quartz.4

The summary of the geology of Wisconsin by Prof. T. C. Chainberlin contains a description of the rocks of the u Potsdam " period. These 

include the "Potsdam" epoch, the Lower Magnesian epoch, and the 

St. Peters epoch, in part. A general description of the formations, accompanied by an account of the life of each epoch, is followed by some 

general observations upon the Cambrian age, to which the formations 

are referred.5

The occurrence of a conglomerate formed of bowlders from the trap 

of the copper-bearing series in a matrix of sandstone that contains fragments of Linguloid shells, apparently Lingulepis pinnaformis, is noted 

by Mr. L. C. Wooster at a locality on the St. Croix River. From the 

mode of occurrence of the conglomerate he concludes that it must have

1 Geology of the upper St. Croix district. Geology of Wisconsin, survey of 1873-1879,1880, vol. 3, pp. 

390-428.

* [Geology of the Mississippi region north of the Wisconsin River.] Geol. Wisconsin, survey of 

1873-79, vol. 4,1882, pp. 38-91.

3 [Geology of the lower St Croix district. J Geol. Wisconsin, survey of 1873-'79, vol. 4,1882, pp. 109- 

130.

4 Further observations on the crystallized sands of the Potsdam sandstone of Wisconsin. Am. JourSci., 3d ser., vol. 24,1882, pp. 47-49. 

6 General Geology. GeoL Wisconsin, survey of 1873-79, vol. 1,1883, pp. 119-200:
WALCOIT.) MINNESOTA. 181

accumulated along a cliff'of the copper-bearing rocks and that the age 

of the conglomerate must be late " Potsdam."1

In an extended paper on the classification of early Cambrian and 

pro-Cambrian formations Prof. R. D. Irving illustrates the unconformity 

between the "Potsdam" sandstone and the subjacent Huronian and 

Keweenawan rocks. He also discusses the similar stratigraphic relations of the Cambrian and pre-Cambrian rocks of the Grand Canon 

Region.2

MINNESOTA.

The presence of the lower sandstone along the Mississippi River 

below the Falls of St. Anthony to the Iowa line was proved by the 

survey of Dr. D. D. Owen in Wisconsin, Iowa, and Minnesota. Alternating exposures of the strata occur along the river and some of the 

tributaries flowing into it from the west.3 On the accompanying map 

there is also a narrow area colored Potsdam along the valley of the 

Minnesota or St. Peter's River.

Little additional information in regard to Minnesota was published 

until Prof. N. H. Winchell, in the first annual report of the geological 

survey of Minnesota, discussed, under the title of "Potsdam Sandstone," 

the Sioux quartzite of northwestern Minnesota, and " The St. Croix 

Sandstone," the fossiliferous sandstone of the southeastern portion of 

the State, referred to the Potsdam by Dr. Owen.4 Of the term " Potsdam," he says:

This term is strictly applicable only to the sandstones of New York State, to which 

the name was first given, and to the equivalents of those strata in their extension 

through the West. It has been abundantly proved that the red sandstones of Lake 

Superior, however disturbed and changed locally, or however much increased in 

thickness by the agency of volcanic outbursts, are the exact equivalents of the New 

York Potsdam. They occupy the first position over the metamorphic slates of the Huronian rocks on which they lie nuconformably, and from which they diifer in being 

but slightly and only locally metamorphosed. They retain usually their evidently 

sedimentary characters, and have not well preserved fossil remains. 5

He states further that in Wisconsin the upper sandstones are found 

to lie unconformably upon the red sandstones where they have been 

tilted by volcanic agency, thus referring the quartzite of Sauk County 

to the Potsdam, and the superjacent fossiliferous, Upper Cambrian 

sandstones that have been correlated by authors with the Potsdam of 

New York, to his St. Croix sandstone. The red sandstone or Sioux 

quartzite is said to be both older than and unconformable with the

1 Transition from the copper-bearing series to the Potsdam. Am. Jour. Sci., 3d ser., vol. 27,1884, pp. 

463-465.

2 On the clarification of the early Cambrian and pre-C ambrian formations. U. S. Geol. Snrv., 7th Ann 

Eep.for 1885-'86,1888, pp. 365-454.

3 Geol. Surv. of Wis., Iowa, and Minn., and incidentally of a portion of Nebraska Territory, Philadelphia, 1852, pp. 48,49.

4 General sketch of the geology of Minnesota. GeoL and Nat Hist Survey Minnesota, 1st Ann. Rep. 

for 1872-'73,1st ed., pp. 68-80. 

5 0p.cit.,p.68.
182 THE CAMBRIAN. [BULL. 81.

light colored sandstones that occupy a conspicuous place in the bluffs 

of the Upper Mississippi, below the Lower Magnesian limestone. Of 

the Sioux quartzite he says that 

Its features here are easily identifiable with those of the Potsdam at the rapids in 

the St. Mary's River, at Sault Ste. Marie, Michigan. In their passage to the west, the 

over-lying, light-colored sandstones seem to become more largely developed. They 

acquire a thickness, including the intercalated beds of shale, of about 600 feet in their 

exposures along the Mississippi River. l

Of the fossils collected from, the horizontal beds at the Falls of the St. 

Croix it is said they:

Were described as coming from the Potsdam sandstone, and were supposed to belong 

to a horizon much lower than that of the Lingula Beds of the Potsdam of New 

York. The name has been still further removed from its original use by the Iowa 

geologists, in its application only to these upper beds, and in giving the name Sionx 

quarlzite to the western representative of the original Potsdam. Dr. Owen, although 

he recognized many points of difference between the Lake Superior and New 

York Potsdam, and these light-colored sandstones of the St. Croix and Upper Mississippi, seems not to have noted the important fact that the former are everywhere subject to distortions and fractures by volcanic forces, while the latter are never known 

to be disturbed by such causes. It is true that he embraces both the red and the 

light-colored sandstones in the designation of " Potsdam, " and argues at length to 

prove the great age of the red. (Geological Survey of Wisconsin, Iowa and Minnesota, p. 187.)

It is in accord with geological precedent, therefore, to separate these two sandstone 

formations under different names, retaining the name of Potsdam for the older, and 

giving provisionally the name of the St. Croix River, on which they are best exposed, 

to the latter.

The following reasons maybe assigned:

(1) The Potsdam beds were laid down before the close of the volcanic disturbance so 

evident in the rocks of the early Silurian and pre-Silurian ages; the Si. Crow beds 

were deposited and still lie in horizontal layers, unconformably not only over the 

Laurentian and latest trappean rocks of the northwest, but also on the upturned 

beds of the Potsdam.2

(2) This reason has little bearing and will not be quoted.

(3) The lithological characters of the Potsdam beds are uniformly different from 

those of the St. Croix beds. The former are hard and often vitreous, usually of a 

brick-red color. Theirbedding is very distinct, and often separated intoslaty layers 

by partings of red shale. They are strongly marked by the so-called fucoidal impressions. They are frequently ripple-marked and sun-cracked. The latter are 

white or buff-colored, often friable, and constitute a heavy bedded or massive sandstone, of handsomely rounded qnartzose grains.

(4) This notes differences in chemical composition.

(6) 3 The Potsdam sandstone has a thickness of at least 400 feet; (Note D. Owen 

makes the thickness of the Potsdam (red sandstones of Lake Superior) over 5,000 feet. 

See Owen's report on Wisconsin, Iowa, and Minnesota, p. 193); the St. Croix sandstone 

also has a thickness of over 500 feet. It is more in keeping with the canons of geological nomenclature to give separate titles to formations so well denned and so largely 

developed.

(7) This gives the evidence of paleontologic differences. He states 

that the fossils of the Potsdam sandstone of New York are Lingula

1 Op. cit., p. 69. * Op. cit., pp. 69,70. * 6th does not occur in the original.
WAI.COTT.] MINNESOTA. 183

antiqua (Con.) and Lingula prima (Con.), a Discma (or Orbicula), and 

uncertain impressions supposed to be of a Pleurotoinaria and of crinoidal remains. A species of Theca has also been described from Keeseville. In comparison to this he cites a large number of species described by Owen and Hall from Wisconsin.1

(S) In this it is shown that the number of species of the Lake Superior 

district and from the New York district, in the sandstone referred by 

him to the Potsdam sandstone, are the same, namely three.

Notwithstanding these considerations, it has not been thought best to attempt the 

delineation of the areas of these sandstones separately on the preliminary geological 

map accompanying this report.2

A detailed description of the lithological characters of the St. Croix 

and Potsdam sandstone is also given.3

The preceding observations by Prof. Winchell have been quoted in 

detail as they are the foundation for the theoretical views subsequently 

advanced by him correlating the Potsdam sandstone of New York with 

various other sandstones of pre-Silurian age,

On the map accompanying the report (opposite p. 45) the Sioux quartzite area of northwestern Minnesota is colored the same as the St. Croix 

sandstone of the southeastern portion of the State. In the legend the 

color is placed under the heading of Potsdam and St. Croix.

In the fourth annual report Prof. Winchell describes the St. Croix sandstone as it occurs in Fillmore County and illustrates the geographic 

distribution on an accompanying map.4 In some notes on a deep 

well drilled at Minneapolis, Minnesota, the same writer states that Nos. 

11,12, and 13 represent the St. Croix sandstone with a total thickness 

of 217 feet. Beneath this there is a red marl and red sandstone which he 

refers to the same horizon as the catlinite beds of the Sioux quartzite 

series. Of No. 14 it is said: "No. 14 may represent the Lingula flags 

or the upper portion of the Potsdam, so called." No. 15 is correlated 

as undoubtedly the upper portion of the great series of marls and sands 

which characterize this horizon in Minnesota. " It is the same formation, as the rock that embraces the well known ' pipestone' or catlinite 

of Minnesota." 5

The Sioux quartzite is referred by Prof. Winchell to the Potsdam 

sandstone in'a description of the geology of rocks in Pipestone County 

in the sixth annual report. ' It includes the famous pipestone quarry near 

the center of Pipestone County.6

A more extended account of the strata referred to the " Potsdam " 

sandstone is published by Prof. Winchell in the tenth annual report

»Op. cit., p. 71. *0p.oit,,p.73. 8 Op.cit.,pp.75-80.

4 Report on the geology of Fillmore County. Geol. and Nat. Hist. Surv., Minnesota; 4th Ann. Eep. 

for 1875,1876, pp. 31-32.

8 Notes on the deep well drilled at East Minneapolis, Minnesota, in 1874-'75. Minn. Acad. Sci., 

Bull., vol. 1,1876, pp. 188-189.

0 The geology of Bock and Pipestone Counties. Geol. and Nat. Bast. Survey, Minnesota, 6th Ann. 

Bep., for 1877,1878, p. 97.
184 THE CAMBRIAN. [BULL. 81.

of the survey. In this he affirms that the horizontal fossiliferous beds 

referred to the Potsdam by Dr. Owen, Prof. Hall, and other authors is 

above the true Potsdam of New York, and that the latter is represented 

by the rocks of the copper-bearing series in the west; also, that no fossils representing the Primordial fauna have yet been discovered in the 

west nor have any been found in the western representative of the Potsdam ; and finally, that the second fauna of Barrande is found in the 

Quebec group of Canada and in the St. Croix sandstone of the west, 

lying in each case above the Potsdam sandstone.1

An article by Dr. J. H. Kloos, translated by Prof. Winchell, describes 

the rocks of the Falls of St. Anthony and the St. Croix Biver,and gives 

a description and a diagrammatic section of the river bank at Taylor's 

Falls, illustrating an unconformity between the Potsdam sandstone and 

the subjacent copper-bearing rocks.2

In an account of the geology of a deep well drilled at Minneapolis 

Prof. Winchell states that the drill passed through sandstone in the 

lower portion of the well as indicated in the following section :3

Feet.

1. Drift................................................... 10

2. Trenton limestone.----......-...................'.......... 24

3. Light, crumbling sandstone (St. Peter?) .................. 125

4. Brown-red pipestone clay................................. 2

5. Potsdam sand ............................................ 42

6. Red quartzite, Potsdam .................................. 102

7. Li gat-colored Potsdam sand and shales.................... 722

8. Red Potsdam sandstone and shales at least................ 347

1,374

Particular attention is called to the brown-red pipestone clay of the 

section, which is the equivalent of No. 12 of that section on page 212. 

No. 6 of the section quoted is compared to a layer of red quartzite, seen 

at New Ulni, Minnesota, and at Baraboo, Wisconsin. Commenting 

upon this he says:

Thus we find an interhedded red quartzite in the Potsdam formation similar to 

those seen in the same formation in the Black Hills and in several other places in 

the Rocky Mountain region. 4

Attention is called to this statement as it is a correlation of a quartzite of the Upper Cambrian rocks of the Black Hills with a bed of 

quartzite in the Sioux quartzite series of Minnesota and the Baraboo 

quartzite series of Wisconsin.

In a tabulation of the strata beneath the lower fossiliferous sand-

'The Potsdam Sandstone. Geol. and Nat. Hist. Survey Minnesota, 10th Ann. Rep. for 1881,1882, 

p. 136.

2 Geological notes on Minnesota. (Translated by N. H. "Winchell.) Geol. and Nat. Hist. Survey 

Minnesota, 10th Ann. Rep. for 1881,1882, pp. 186-200.

3 The geology of the deep well drilled by C. C. Whelpley at Minneapolis, at the " C " Waahborn Mill. 

Geol. and Nat. Hist. Survey Minnesota, 10th Ann. Rep. for 1881,1882, p. 217.

4 Op. cit., p. 214.
MINNESOTA. 185

stone or St. Croix sandstone, Prof. N". H. Winchell defines the Potsdam formation as follows: 1

Potsdam formation. Tilted red sandstones, shales and conglomerates, changed by 

igneous gabbros and dolerites locally to red quartzites, felsites, quartz-porphyries 

and to red granite. The Keweenian and Huronian in part, in Wisconsin.

He places the Taconic group second and defines it as-follows:

Taconio group. Horizontal black slates and gray quartzites, with interbedded 

limestones and diorites (the Animikie group), changed to tilted slates, quartzites, 

iron ores, and silicious marble. The Gunfliut beds, the Mesabi iron rocks, the 

Ogishke Muncie conglomerate (?), the Thomson slates and quartzites, the Vermilion 

iron rocks; the Huronian in part, in Wisconsin and Michigan.

A description of the Sioux quartzite as it occurs at Few Ulm is 

given by Prof. Winchell in the second annual report.2 In the first volume of the final report of the Minnesota survey he describes the St. 

Croix sandstone as it occurs in Houston, Winona, and Fillmore Counties.3 

The entire thickness of the formation in Wiuona varies from 488 to 553 

feet.4 Under the title of Potsdam quartzite a description is given in 

this volume by Messrs. Winchell and TJpham of the pre-Cambrian 

quartzite of northwestern Minnesota.5

From the Sioux quartzite series at Pipestone, Minnesota, Prof. 

Winchell described, in 1885, Lingula calumet and JParadoxides larberi, 

referring them to the equivalent of the Potsdam sandstone of New 

York.6

In a note on the revision of the stratigraphy of the Cambrian in 

Minnesota, Prof. Wiuchell includes under the St. Croix terrane, Jordan 

sandstone, St. Lawrence limestone, shales, and Dresbach sandrock.7 

It is interesting to note that after the upper member of the St. Croix, 

the Jordan sandstone, we find " Potsdam " (?); also after the Dresbach 

sandstone at the base and (Potsdam) after formations placed as preSt. Croix.

The geological age of the Sioux quartzite of the pipestone quarries 

in Dakota and Minnesota is discussed by Prof. E. D. Irving,8 who concludes that their tilted position, great thickness, and lithologica*L contrast with the Potsdam sandstone " make it evident that they are not 

merely a downward continuation of that formation, but, on the contrary, form a great unconformably underlying series."

1 Notes on the age of the rocks of the Mesabi and Vermilion iron districts. Geol. and Nat. Hist., 

Survey Minnesota, llth Ann. Rep. for 1883,1884, p. 170.

"The geology of the Minnesota Valley. Geol. and Nat. Hist. Sur v., Minn. 2d Ann. Kep. for!873,1874, 

p. 157.

3 The Geology of Minnesota. Vol. 1, of the Final Report, 1884, pp. 223-227,257-259.

4 Op. cit.,p. 258.

6 Op. cit. pp. 422-424, 499-503.

6 FoHflils from the red quartzite at Pipestone. Geol. and Nat.Hist. Stirv. Minnesota, 13th Ann. Hep. 

for 1884,1885. pp. 65-72.

7 Revision of the stratigraphy of the Cambrian in Minnesota. Geol. and Nat. Hist. Survey Minnesota, 14th Ann. Rep. for 1885,1886, p. 337

8 Preliminary paper on an Investigation of the Archean formations of the Northwestern States. T7. 

& Geol. Surv. 5th Ann. Rep., 1883-84,1885, pp. 201,202.
186 THE CAMBRIAN. [BOLL. 81.

Mr. "Warren Upham in notes on the geology of Minnehaha County, 

Dakota,1 refers to the rocks in various portions of Minn ehaha County 

as " Typical Potsdam quartzite," but he mentions no reasons for concluding it to be of this age. No fossils were found in it.

In the second volume of the Geology of Minnesota Prof. N. H. Winchell states that the St. Croix formation in Wabasha County is about 

250 or 300 feet in thickness; and it is not known to vary particularly 

in its stratigraphic composition from that of Winoiia Co unty.2 In the 

account of the geology of Goodhue County he describes the formation 

and accompanies it with a list of the fossils found in the St. Croix 

formation in the Upper Mississippi Yalley.3

In the same volume Mr. Warren Upham describes the St. Croix sandstone as it occurs in Ohisago County,in the valley of the St. Croix River.4 

He also describes the formation as it occurs in Pine County, along the 

upper portion of the St. Croix River.5

In an article on the age of the St. Croix sandstone, Prof. N. H. 

Winchell discusses its relations to the typical Potsdam of New York 

and concludes it is a distinct formation.6 In an account of a deep well 

drilled at Stillwater, Minnesota, it is stated by Mr. A. D. Meads that 

The well starts at about 740 feet above the sea, and after passing through 701 feet 

of drift, white friable sandstone, and green shales belonging to the St. Croix and socalled Potsdam of the Northwest, enters a series of dark red and brown shales and 

brown feldspathic sandstones which exhibited a thickness of more than 1,500 feet. 

These gradually assume characters of a volcanic detrital tuff " amygdaloidal," calcitic, kaolinic, still brown, slightly siliceous and finally at the depth of about 3,300 

feet unmistakable beds of trap rock were encountered, alternating with sandstone 

beds. At this depth some grains of native copper were seen in the drillings. 7

Prof. N. H. Winchell has recently published his latest conclusions on 

the Tacouic rocks of Minnesota. On the evidence of the tracks described by Mr. G. F. Matthew8 he considers the Taconic (Lower Cambrian) age of the " Animike" formation to be sufficiently established, 

and thinks the name Taconic should be substituted for Animike.9 The 

Pewabic quartzite is referred to the base of the "Animike," although he 

says: "it was at first supposed to be the equivalent of the Potsdam 

(Paradoxides horizon) which apparently overlies the "Animike."10

A correction is made in relation to the reference of the stratigraphic 

position of the Granular quartz as follows r11

I Notes on the geology of Minnehaha County, Dakota. Geol. and Nat. Hist. Survey, Minnesota, 13th 

Ann. Eep. for 1884,1885, pp. 88-97.

2 The Geology of Minnesota. Vol. 2 of Final Eeport, 1888, p. 13.

3 Op. cit., pp. 31-36.

4 The Geology of Minnesota. Vol. 2, Final Report, 1888, pp. 407,409.

6 Op. cit., pp. 637-642.

6 Geol. and Nat. Hist. Surv. of Minn., 17th Ann. Hep. for 1888,1889, pp. 56-84.

' The Stillwater Deep Well. American Geologist, vol. 3,1889, p. 342.

 Am. Jour. Sci., 3d ser., vol. 39, 1890, p. 145.

9 The iron ores of Minnesota. Geol. and Nat. Hist. Surv. Minnesota. Bull. No. 6,1891, p. 113.

">0p. cit., p. 125.

II Op. cit. Foot note on pp. 417,418.
WALCOTT.) IOWA. 187

The writer wishes to correct the view published by him in the American Geologist 

a few years ago ("A Great Primordial Quartxyte," vol. 1, p. 178), that the granular 

quartz probably overlies the black slate of the Taconic system, and is equivalent of 

the Redsandrock of Vermont. The Red sandrock appears to be a part and near the 

top of the "Georgia series" and above the Winooski marble, but the "granular 

quartz" lies below the Winooski marble. The typical Potsdam is probably the 

' ^granular quartz." But the Red sandrock, and also some light-colored, loose sandstones still higher have very largely been regarded its equivalent.

IOWA.

On the map accompanying Dr. D. ~D. Owen's report of the geological 

survey of Wisconsin, Iowa, and Minnesota a small area is colored as the 

Potsdam sandstone of New York, in the northeastern corner of the 

State. 1

As State geologist of Iowa, Prof. J. Hall stated that the Potsdam 

sandstone attains its greatest exposures in Minnesota and Wisconsin 

north of the limits of Iowa, and about the regions of Lake Fepin. The 

excavation of the Upper Iowa Kiver, however, has removed the calciferous sandstone; so that at the junction of that river with the Mississippi there is exposed a broad belt of the lower rock. A general description of the sandstone is given with the statement that some slightly 

calcareous bands contain fragments of trilobites. In numerous localities shells of Lingula are found, though by no means so abundantly as 

in the same rocks in Minnesota. These fossiliferous bauds appear in 

the vicinity of Lansing.2 In the same volume there is a general ac 

count of the Potsdam or inferior sandstone by Prof. J. D. Whitney.3

In a general description of the geology of Iowa Dr. C. A. White describes the Sioux quartzite as occurring in the extreme northwestern 

corner of the State. In the table of classification he places it as Huronian (?) and beneath the Potsdam sandstone.4 This is the quartzite 

referred to the Potsdam in Minnesota by Prof. N. H. Winchell. 'In 

describing the Potsdam sandstone Dr. White states that it reaches a 

known thickness in Iowa of 300 feet, and it is exposed only in a small 

portion of the northeastern corner of the State.5

In the account of a deep well at Emmetsburg, Iowa, Prof. JN". H. Winchell refers to a white sandstone found beneath the blue shales of St. 

Croix, assigning it a thickness of 107 feet. The rock beneath this, which 

Mr. Swan, who kept a record of the well, called granite, is referred to 

the Potsdam quartzite.6

1 GooF. Surv. of Wise., Iowa, and Minn.; and, incidentally, of a portion of Nebraska Territory, 

Philadelphia, 1852.

2 Geology of Iowa, vol. 1, 1868, pp. 47-48.

"Ibid., pp. 328-331.

4 General geology. Azoic, Lower Silurian, Upper Silurian, and Devonian systems. Geol. Surv. Iowa, 

Rep., vol.1,1870, p. 168.

"Op. cit, p. 172.

8 Section of a deep well at Emmetsburg, Iowa. Minn. Aoad. SoL Bull., voL 1,1880, pp. 387,388.
188 THE CAMBRIAN. [BULL. 81.

In describing a deep well at Washington, io southeastern Iowa, Prof. 

S. Calvin states that a gray.sandstoue 1,230 feet from the surface probably represents the upper part of the Potsdam series.1

LAKE SUPERIOR SANDSTONE.

In an account of a journey along the south shore of Lake Superior:, 

Dr. J. J. Bigsby describes a red and white sandstone, for the most part 

horizontal, that predominates &long the shore, resting in places on 

granite.2 He also mentions the red sandstone of Point Keewawoonan 

and the sandrock described to him by Mr. Thomson.3

The description of the geology of Lake Superior, by Capt. H. W. 

Bayfield, mentions a horizontally stratified sandstone that he traced 

from one extremity of the lake to the other, on both the north and 

south shores, and on many of the islands in the lake. A description 

of the mode of occurrence of the sandstone on the south shore of the 

lake is given, with several diagrams illustrating the unconformity between the granite and the sandstone.4 He considers it quite probable 

that the formation extended to the west and southwest as far as the 

foot of the Eocky Mountains, and that it might possibly be the same 

as the sandstone at the Falls of Niagara, etc., but concluded it required 

much more elaborate investigation than has yet been bestowed to render it certain that the sandstone of Lake Superior and that of the 

extensive tracts of country mentioned are the same formation. He 

then gives reasons for terming the sandstone of Lake Superior the Old 

Red. These are its position immediately on the granite, its structure, 

and component parts.6 No fossils were observed. The student will 

find in this paper of Capt. Bayfield's a very fair description of the sandstones as they occur about Lake Superior, and it is worth reading in 

connection with the controversy in relation to their age.

As State geologist of Michigan Dr. Douglass Houghton reported 

upon the strata of the northern peninsula. In the second annual report 

he says that "the Old Red sandstone" has been very much shattered by 

the protrusion of trap rock through it.6 In his third report a more extended account is given of the Lake Superior sandstone on the Ste, 

Marie Eiver. The sandstone passes conformably beneath the superjacent limestone.7 Of the bulk of the formation he says:

The Lake Superior sandstone in its easterly prolongation does not attain a very 

great thickness, but in proceeding westerly this thickness is vastly increased, attaining 

on the south shore of Lake Superior to several hundred feet.

'Notes on the formations passed through in boring the deep well at Washington, Iowa. American 

Geologist, vol. 1,1888, p. 30.

2 Notes on the geography and geology of Lake Superior. Quart. Jour. Lit., Sci. and Arts (of the Royal 

lust, of Gt. Brit.) vol. 18,1825, p. 33.

3 Op. cit., p. 260.

4 Outlines of the geology of Lake Superior. Quebec Lit. and Hist. Soc. Trans., vol. 1,1829, p. 17, figs. 

2 and 3, on plate. 

8 Op. cit, p. 19.

6 (Peninsula District.) Second annual report State geologist of Michigan, Detroit, 1839, p. 14.

7 Third annual report State geologist of Michigan. House Reps. Document, No. 8,1840, p. 14.
WALCOTT.J LAKE SUPEEIOR SANDSTONE. 189

 So far as my examinations during the past year have extended the rock is destitute 

of fossils, and in fact after a careful examination (several years ago) along its whole 

line of outcrop, on the southerly shore of Lake Superior, 1 have never been able to 

detect in the rocks a single contained fossil. 1 f

The fourth report describes the "lower or red sandstone and shales" 

as follows:

The red sandstone, with its accompanying red and gray shales, occupies a much 

larger extent of the country bordering upon Lake Superior than any other single rock 

or group of rocks. It rests upon the primary and motainorphic rocks immediately 

west from Chocolate River; upon the conglomerate and mixed rocks from near Eagle 

Eiver, of Keweeuaw Point, west to the head of Lake Superior; upon the primary 

trap, metamorphic and conglomerate rocks of the north shore of the lake, and upon 

the conglomerate rock of Isle Royale. It is this rock which forms the basis of the 

level plateaus or valleys occupying the spaces between the several ranges of hilla 

south from Lake Superior, and west from Chocolate River. In these last situations 

this rock is frequently seen undisturbed to surround the bases of isolated knobs of 

granite, though when near to or in contact with knobs or [of] trap there are invariable evidences of very great disturbance. 8

A second bed of sandstone is described as the " upper or gray sandstone." " Upon the shore of Lake Superior, and extending from Point 

Iroqnois to Grand Island, a sandstone occurs, differing widely in its 

appearance from that before described. This sandstone rests unconformably upon the red sandstone, the former dipping gently to the south 

or southeast, while the latter dips very considerably to the north or 

northwest."3

A sandy limerock rests conformably and immediately upon the upper 

or gray sandstone. The tabulation of the rocks of. the Upper Peninsula 

is as follows:4

9. Tertiary clays and sands.

8. Upper limerock group (embracing as members the Drummond Island

and Mackinaw limestones). 

7. Lower lime rock and shales. 

6. Sandy or intermediate limestone.

Thickness. 

5. Upper or gray sandstone, mean .........................feet.. 700

4. Lower or red sand rock and shales, extreme .............. do... 6,500

3. Mixed conglomerate and sand rock, extreme ............. do... 4,200

2. Conglomerate rock, extreme.............................do... 5,260

1. Metamorphic, trap, and primary rocks.

A detailed account of the red sandrock and shales is given on pages 

37 to 41. This is followed by a description of the upper or gray sand 

rock, of which he says:.

The only remaining rock which separates the red sandrock from the limestone lying 

to the south is a gray or brownish sandrock that is almost wholly composed of 

grains of quartz, usually feebly cemented with calcareous matter. The composition 

of this rock differs from that of the lower sand rock in being more exclusively quartz, 

while in epoch of deposition the rock under consideration should not be confounded 

with that of the red sandstone. It has already been stated that the red sandrock of

>0p.cit.,p. 15. *0p.cit.,p. 19. 

 Fourth Ann. Hep. State geologist of Michigan, *0p.cit.,p.22. 

1841, pp. 18,19.
190 THE CAMBRIAN. [BULL.81.

the south coast dips regularly northerly, while the upper or gray sandstone dips 

equally regularly south or southeasterly, in which respect the last-mentioned rock 

conforms to the limestones resting upon it, while it rests itself upon the uptilted edge 

of the red sandrock helow. 1

The upper saudrock, like the lower, abounds in clearly denned ripple marks, and 

its line of cleavage is very irregular, frequently being opposed to the line of stratification over very considerable districts of country.- Two indistinct species of fucoides 

were all the fossils noticed in connection, with it.

1 was unable to obtain any observations upon the thickness of the upper sand rock 

which were satisfactory, but from the imperfect observations which were obtained I 

was led to conclude that the average thickness as far westerly as the Pictured Rocks 

does not vary far from 700 feet. The upper sandrock, like the rocks before mentioned, 

wedges out as far as we proceed in an easterly direction. 2

When presenting to the Boston Society of Natural History an account of his visit to Lake Superior Prof. H. D. Eogers states that he 

discovered in the neighborhood of Chocolate and Carp Rivers the following conditions of stratification:

First, a group of rocks, the equivalents, undoubtedly, of the Primal sandstone and 

Primal slate of Profs. W. B. Rogers anclJEL D. Rogers, denominated, in the nomenclature of the New York survey, the Potsdam sandstone, and these rocks, highly inclined, and traversed by parallel east and west axes. Secondly, upon the uptilted 

edges of this earliest Paleozoic formation rests, in an unconformable position and 

with a very gentle northern dip, the conglomerates and shales of the red sandstone 

series. Specimens of the conglomerate were displayed, in which the pebbles 'Were 

all from the older rocks. Mr. Rogers thought this fact of uncouformable superposition an almost conclusive proof of a post-Paleozoic date; and he proceeded to argue, 

from various points of analogy between the red sandstone itself, its trappean dikes, 

and their mineral associations, with similar components of the Mesozoic or new 

red sandstone of the Atlantic States, that the formation in question is of equivalent 

age and origin with this last-named interesting group of rocks.3

In his reconnaissance of the Cbippewa land district of Wisconsin, Dr. 

D. D. Owen examined a portion of the shores of Lake Superior. He 

noted the red sandstone, its mode of occurrence, and character. He 

states that various views have been advanced by different writers regarding the age of the red sandstone, marls, and conglomerates of Lake 

Superior. Some authors have referred them to the date of the oldest 

sandstones of the New York system; others believe them to be contemporaneous with the New Red sandstone of Great Britain and the 

bunter Sandstein of Germany. He further states:

Judging, however, from lithological and mineralogical character, there certainly 

is strong presumptive evidence that they were deposited subsequently to the Carboniferous era.

He calls attention to the strong resemblance between them and the 

formations above the Coal Measures, not only of the State, but of some 

parts of Europe.

Ranging through Connecticut, New Jersey, Maryland, and Virginia there are red 

sandstone and marly beds that are almost a counterpart of some portion of the Lake 

Superior formations, as well in aspect as in composition; like them, too, they are

1 Op.cit,pp.41,42.

2 Op. cit., pp. 42,43.

3 On the mineralogy and geology of the south shore of Lake Superior. Boston Soo. Nat. Hist. Proc. 

vol. 2,1816, p. 125.
WALCOTT.] LAKE SUPERIOR SANDSTONE. 191

traversed by ranges of intrusive trap, with accompanying veins of copper. » * 

To draw up in detail a comparison between these formations and those of the Northwest would, at this early stage of the survey of Wisconsin, be premature. 1

In 1849 Prof. 0. T. Jackson argaed that the red sandstone and conglomerate rocks of Keweenaw Point existed there anterior to the elevation of the trap rocks, and that the eastern sandstone and the red 

sandstone were the same in geologic age. After reviewing the mode of 

occurrence and the.relation of the sandstone to other rocks, especially 

a limestone from which a fragment of Pentamerus oUongus was obtained, indicating the upper member of the Niagara, New York series, 

he concluded that the sandstone of Keweenaw Point was not of the 

Potsdam series,but that it was most probably the New Red, or that system of sandstones which is regarded as such in New England.2

In their report of 1849 Messrs. Foster and Whitney color the accompanying map of Keweenaw Point so as to indicate that they consider 

the sandstone and conglomerate superior to the trap series, forming 

the base of the Silurian system. The same coloring and nomenclature 

are used on the map of the district between Mackinaw Bay and Chocolate Eiver, and that between Portage Lake and Montreal River and 

Isle Royale.3

In the same volume, following the report by Foster and Whitney, is 

a general description of the region between Keweenaw Point and Montreal River. The writer says the age of the sandstone of Lake Superior 

could not be determined by any evidence he had been able to collect. 

It is entirely destitute of fossils, and lies directly upon granitic rocks.4 

Whether it is written by Mr. Foster or Prof. Whitney is not stated.

Mr. J. W. Foster states that he is disposed to regard the sandstone 

of Lake Superior as resting at the base of all the fossiliferous rocks.5 

He evidently considered the horizontally bedded sandstone at Keweenaw Point the same as the disturbed sandstone on the opposite side. 

Full descriptive details of the sandstones at Keweenaw Point are also 

given by Mr. W. A. Burt.6 In the same report Mr. Bela Hubbard 

states that the Red sandrock is the equivalent of the Potsdam red sandrock of the New York reports, and that on the map the geographic distribution skirts the trap range on both sides, but having by far its 

broadest extension on the south side.

1 Report of a geological reconnaissance of the Chippewa land district of Wisconsin ; and incidentally 

of a part of Iowa and of the Minnesota Territory, 30th Congress, 1st sess., Senate Ex. Doc. Na. 57, 

1848, pp. 57-58.

2 Keport on the geological and mineralogical survey of the mineral lands of the United States in the 

State of Michigan, Ex. Doc. No. 5, House of Reps., 31st Congress, 1st sess., parts, 1849, pp.398, 399, 

452.

3 Synopsis of the explorations of the geological corps in the Lake Superior land district in the northera peninsula of Michigan, Ex. Doc. No. 5, House of Reps., Blst Congress, 1st sess., part 3,1849, pp. 

605-625.

4 0p.cit.,p.655.

6 Notes on the geology and topography of portions of the country adjacent to Lakes Superior and 

Michigan, in the Chippewa land district, Ex.Doc. No. 5,31st Congress, 1st sess., part 3, 1849, p. 781.

6 Topography and geology of the survey of a district of township lines south of Lake Superior, 1845, 

H. K. Ex. Doo. No. 5, part 3, 1849, pp. 815-839.
192 THE CAMBRIAN. {BULL. 81.

It here lies in nearly horizontal strata, though at the coast a slight dip inland is 

observable, becoming more apparent as it approaches the basin of Portage Lake. la 

its approach to the trap, however, it is found more or less tilted from its original 

horizontal position, and is also very much altered by its contact with that igneous 

rock. The evidences both of the deposition of this extensive rock formation in calm 

and shallow waters and of the subsequent change induced in it by the trap rocks 

when in a fused or heated state are very important. 1

In their report upon the copper region of Lake Superior, Messrs. 

Foster and Whitney tabulate the stratified sedimentary rocks as follows : 2

I. Conglomerate.^Not strictly a sedimentary rock, but a volcanic tuff.

II. Inferior sandstone. Potsdam sandstone.

III. Compact or Lower Magnesian limestone. Calciferous sandstone, Chazy limestone, Bird's-eye and Black Eiver limestone.

This table is followed by a detailed description of the conglomerate, 

sandstone and superjacent limestone. No attempt is made to differentiate the horizontally bedded Red sandstone, of Keweenaw Point, from 

the banded sandstone that occurs on the western part of tflie Point.

Of the transition of the sandstone to the magnesian limestone they 

say:

The sandstone, as we ascend from the lower strata to the higher, is found to be less 

colored by the oxides of iron, and to take into its composition particles of lime until 

finally it passes into well characterized, compact, magnesian limestone. * * * 

We apply the term magnesian to this belt to define its lithological characters, although 

the associated organic remains would seem to indicate the presence of several of the 

lower Silurian groups, which can not be recognized by lithological differences. 3

A notice of the work by Foster and Whitney in the copper district 

was published in the American Journal of Science, 2d series, volume 

12, 1851, pp. 222-239.

In a letter describing the Silurian terrane of Lake Superior, Messrs. 

Foster and Whitney reaffirm their opinion that the standstones of Lake 

Superior are of the age of the Potsdam of the New York series, and 

that the section exhibits the Azoic system at the base, upon which rests 

the conglomerate, formed of igneous rocks, and then in turn the Potsdam sandstone, the Calciferous sandstone, the Trenton limestone, etc.4

In commenting upon this statement of Messrs. Foster and Whitney, 

that the Lake Superior sandstones are of the same age as the Potsdam 

sandrock of New York, Prof. Jules Marcou disputes their correlation 

and considers the formation as equivalent to the New Eed sandstone, as 

was stated by Prof. Jackson.5

1 General observations upon the geology and topography of the district south of Lake Superior, subdivided in 18to under Hougbton, House of Heps., .Ex. Doc. No. 5, part 3,1849, p. 840.

2 .Report on the geology and topography of a portion of the Lake Superior land district in the State 

of Michigan. Washington, 1850. Stratified and sedimentary rocks. Vol. 1, 1850, p. 99.

3 Op.cit., p. 117.

* (Apercu do 1'ensemble des Terrains Siluriens du lac Sup6rieur.) Bull. Soc. g6ol. franco, 2« s6r., 

vol. 8,1850, p. 91.

6 Response a lettre de MM. Foster et Whitney sur le lac Supeoeur. Bull. Soc. geol. France, 2° s6r., 

vol.8,1850, pp. 101-105.
WALCOTT.J LAKE SUPERIOR SANDSTONE. 193

In their report on the geology of the Lake Superior land district, 

Messrs. Foster and Whitney describe, under the heading of " Potsdam 

sandstone," 1 a sandstone on the north shore, occurring in insulated 

patches on the isthmus between Thunder and Black Buys. This sandstone attains, according to Logan, a thickness of at least 200 feet.2 On 

the south shore the sandstones of the northwestern side of Keweenaw 

Point are considered to be of the same age as those on the south side 

of the point, extending along the lake shore from Keweeuaw Bay to St. 

Mary's Eiver. The sandstone extending southward, subparallel to the 

bay, is also cor related with the sandstone mentioned; and all of these 

are correlated with the Potsdam sandstone of the New York series. 

They quote from the manuscript of Prof. James Hall in relation to the 

westward extension of the sandstone in Wisconsin, in the Upper Mississippi Valley.3

In some observations on the age of the sandstones of the United 

States Prof. C. T. Jackson concludes that the Lake Superior sandstone 

is of Upper Silurian age. 4

Messrs. Foster and Whitney returned to the discussion of the age of 

the sandstone of Lake Superior in 1851 and conclude there can no longer 

be any doubt that this sandstone lies below the lowest fossiliferous 

members of the Silurian in the position of the Potsdam sandstone of 

New York.5 They describe with considerable detail the mode of occurrence of the horizontally bedded sandstone at the southeastern end of 

the lake along the Sault Ste. Marie, with its extension westward along 

the coast to Keweenaw Bay. They show it to be one continuous formation around the great central granitic and azoic nucleus; that it is 

a granular, quartzose material, mostly friable, and containing little 

iron ; that the thickness of the whole formation did not exceed 100 feet 

at Sault Ste. Marie, and that at the Pictured Eocks it was probably 

more than 300 or 350 feet, gradually increasing from the east toward 

the west.6 They then describe a sandstone on the western side of the 

Keweenaw Point and Isle Eoyale which is now referred to the Algonkian. This is the best re'sume' of the information relating to the Lake 

Superior sandstone published up to its date.

In his tabulation of the lowest Protozoic sandstones Dr. D. D. Owen 

places the Lake Superior ferruginous and argillaceous sandstones, 

shales, and conglomerates at the base of the section, assigning it a 

thickness of 5,000 feet.7 On the accompanying map the Lake Superior

1 Lower Silurian System. Potsdam and Calciferous Sandstones. Kept, on Geol. of Lake Superior 

Laud Distr., Pt. 2, 1851, pp. 113-134.

2 Op. cit., p. 115.

8 Op. cit, pp. 133, 134.

4 [Some observations on the age of the sandstones of the United States.] Bost. Soc. Nat. Hist. Proo., 

vol. 3, 1851, pp. 335,33G.

6 On the age of the sandstone of Lake Superior, with a description of the phenomena of igneous 

roclcsi. Am. Assoc. Proo., vol. 5. 1851, p. 25.

6 Op. cit., p. 29.

»Geol. Surv. of Wis., Iowa, and Minn., and, incidentally, of a portion of Nebraska Territory. 

Philadelphia, 1852, p. 53.

Bull. 81 13
194 THE CAMBRIAN. . [BULL. 81.

sandstone west of the Montreal Eiver is colored the same as the sandstones of the central portion of Wisconsin referred to the Potsdam. In 

the legend the Lake Superior sandstone is included with the lower 

sandstones of Wisconsin and Minnesota as the equivalent of the Potsdam sandstone of New York.

Mr. J. 0. Norwood calls attention to the resemblance of the sandstone 

on the south shore of Lake Superior, west of Montreal Eiver, to the 

sandstones of the Cbippewa, St. Croix, and Kettle Eivers. A section 

is given that occurs above the mouth of Cranberry Eiver. 1

In some remarks connected with the geology of the north shore of 

Lake Superior Prof. J. D. Whitney states that from Sault Ste. Marie, 

following the south shore in its whole extent, and along the north side 

as far east as the northeastern extremity of Neepigon Bay, we find exposed on the lake shore only shales, sandstones, and conglomerates, 

the equivalent of the Potsdam sandstone and the accompanying trappean rocks.2

In speaking of the red sandstone of Lake Superior Mr. H. E. Schoolcraft states that in his expedition of 1820 he recognized a sandstone at 

the Sault of St. Mary's, tie says:

That this is the Old Keel sandstone may be inferred simply from the fact that, although deposited originally in horizontal beds, its position has been disturbed in 

many localities. 3

In his report as State geologist of Michigan Dr. A. Winchell describes 

the sandstone at the Falls of the St. Mary's Eiver, where it has a 

measured thickness of at least 18 feet. On some of the surfaces he observed obscure traces of Algse. On some specimens from the Montreal 

Eiver not less than three species of fossil plants have been discovered. 

He favors the view that the sandstones of the south shore of Lake Superior are of the age of the Potsdam.4

When commenting upon the fact that Prof. Jules Marcou had referred the red sandstone of Lake Superior to the Trias Prof. J. S. 

New berry states:

No American geologist will need to be informed that the sandstones of Lake Superior are of the age of the Potsdam of New York and lie at the base of the Silurian 

series. It is true that there is considerable lithological resemblance between the 

Potsdam sandstones of Lake Superior and those overlying the Carboniferous series iu 

New Mexico; but that fact serves simply to show how fallacious are the inferences 

derived aloue from lithological characters.6

1 Description of the geology of middle and western Minn., including the country adjacent to tbo 

northwest and part of the southwest shore of Lake Superior. Rep. Geol. Surv. of Wis., Iowa, and 

Minn., and, incidentally, of a portion of Nebraska Territory. Philadelphia, 1852, p. 269.

2 Remarks on some points connected with the geology of the north shore of Lake Superior. Am. 

Assoc. Proc., vol. 9, 1855, p. 205.

3 Observations on the geology and mineralogy of the region embracing the sources of the Mississippi 

River and the Great Lake basins during the expedition of 1820. Schoolcraft's' Mississippi River. 

Phila., 1855, pp. 316,317.

4 Geology, general sketch. Geol. Surv. Michigan, 1st Biennial Rep. of Prog. Lansing, 1861, pp. 

49-51.

6 Geological report. Report upon the Colorado River of the West, expl. in 1857-'58 by Lieut. J. 0. Ives. 

Part ill, 1861, p. 75.
WALCOTT.] LAKE SUPERIOE SANDSTONE. 195

Of the sandstone at the base of the fossiliferous series Dr. T. S. Hunt 

says:

Along the northern rim of the great Paleozoic basin of North America the Potsdam 

saudstone of the New York geologists is unquestionably the lowest rock from below 

Quebec to the Island of Montreal, and thence passing up the valley of Lake Champlain 

and sweeping round the Adirondack Mountains until it reenters Canada and soon disappears to the north of Lake Ontario, where the Birdseye and Black Kiver limestones 

repose directly upon the Lanrentian rocks, and furthermore overlie the great Lake 

Superior group of slates and sandstones, which .reposing on the uncouformable Hurouian system, constitute the upper copper-bearing rocks of this region. This Lake 

Superior group, as Sir William Logan remarks, may then include the Potsdam, Calciferous, and Chazy, and thus be equivalent in part to the Quebec group, hereafter to 

be described. 1

The section on the Montreal Eiver, including 11,850 feet of strata, 

according to Mr. Charles Whittlesey, is referred by him to the Potsdam 

sandstone, with a statement that this is not the entire thickness of the 

Potsdam at the mouth of the Montreal.2 He states that some foreign 

geologists have essayed to place this formation nearly at the summit 

of the geological system, not only without evidence but against the most 

conclusive proof. He correlates the sandstone at the Falls of the St. 

Croix, with its abundance of fossils, with the sandstone of the section 

mentioned, and states that it has been traced strati graphically beneath 

the Trenton and Calciferous strata of the New York survey, on the 

St. Mary's Eiver, at the Pictured Bocks, on the Escanawba, the Menomiuee, Oconto, Wolf, Wisconsin, and St. Croix Eivers.3

The view that the sandstones and superjacent rocks of the south 

shore of Lake Superior were deposited within the lake's basin when 

the lake stood at a higher level has been held only, as far as known to 

me, by Mr. Thomas Macfarlane. In a report on the geological formations of Lake Superior he says:

On the other hand, the Upper rocks and St. Mary sandstones are never found far 

inland, but occur close to the shore in comparatively low-lying land and rocks. They 

seem to have had, as the theater of their eruption and deposition, the bottom of the 

lake, at a time when its surface was at a higher level than it is at present, although 

not so high as the general surface of the surrounding Laureutian and Huroniau hills. 4

In a paper on the position of the sandstone of the southern slope of 

a portion of Keweenaw Point, Lake Superior. Prof. Alexander Agassiz 

states that the sandstone of the southern side of the mineral range in 

the vicinity of Torch Lake is plainly of a different age, lying, as it does, 

unconformably upon the former (i. e., the trap). This view agrees with 

that held by the geologists who refer the sandstone of the southern portion of Keweenaw Point to the Potsdam, and that of the northern 

coast to a pre-Potsdam formation.5

1 Ou some points in American geology. Am. Jour. Sci., 3d ser., vol. 31,1861, p. 397.

2 The Ponokio Mineral Range, Wisconsin. Bost. Soc. Nat. Hist. Proo., vol. 9,1863, p. 238. 

3 Op.cit.,p.239.

4 0u the geological formation of Lake Superior. Canad. Naturalist, new ser., vol. 3,1867, p. 178. 

"On the position of the sandstone of the southern slope of a portion of Keweenaw Point, Lake 

Superior. Bostou Soc. Nat. Hist., Proc., vol. 11, 1868, p. 245.
196 THE CAMBRIAN. [BULL.81.

In an article on the age of the copper-bearing rocks of Lake Superior, Messrs. Brooks and Pumpelly refer the sandstones of the south 

shore to the Silurian, and state that they were deposited uuconforinably upon the subjacent copper-bearing rocks.1

In his report upon the Paleozoic rocks of Michigan, Dr. 0. Bominger concludes that the Lake Superior sandstone is the equivalent of the 

Potsdam sandstone. He states that there is no record of any instance 

iu which recognizable fossils were found in situ in the Lake Superior 

sandstone.2 The reference of the sandstones of the western side of 

Keweenaw Point is based upon their lithologic resemblance to those 

east of the trap range along the center of the point.

In a paper on some points in the geology of northern Wisconsin 

Prof. E. D. Irving drew the conclusions that 

(1) The Copper-Bearing and Huronian series were once spread out horizontally 

one over the other and owe their present highly tilted position to one and the same 

disturbance. (2) That subsequently, after a long period of erosion, the horizontal 

Silurian sandstones were laid down over and against the upturned edges of the 

Copper-Bearing series, filling also the synclinal, in Ashland County, which lies between the northward and southward dipping sandstones. (3) That hence the Copper-Bearing series is more clearly allied to the Archean than to the Silurian rocks.3

He describes the series of horizontal sandstones and shales that form 

the basement rock of the Apostle Islands and the north coast line of 

Ashland, Bayfield, and Douglas Counties. These he considers in every 

way to be the equivalent, or, which is more probable, the downward 

continuation of light-colored Primordial sandstone of the Mississippi 

Valley. They reappear farther south, on the headwaters of the St. 

Croix, from whence they can be traced uninterruptedly until they disappear beneath the light-colored sandstones of the Mississippi Valley.4 

This paper of Prof. Irviug's was reprinted in the American Journal of 

Science, under the title u On the age of the copper-bearing rocks of 

Lake Superior," etc.5

It is stated by Mr. E. T. Sweet that the term " Lake Superior sandstone" "is generally employed to designate the reddish aluminous 

sandstones which nearly everywhere border the south shore of Lake 

Superior. They also form the basement rock of the Apostle Islands. 

They have never been found in a tilted condition." 6 He considers that 

Dr. Kominger, of the Michigan Geological Survey, has definitely settled that these sandstones are the downward continuation of the lightcolored sandstones of the Mississippi Valley;7 and concludes that the 

western sandstone of Irving, or that of the Apostle Islands and vicin1 On the age of the copper-bearing rocks of Lake Superior. Am. Jour. Soi., 3d ser., vol. 3,1872, pp. 

431-432.

2 Paleozoic rocks. Geol. Surv. Michigan, Upper Peninsula, 1869-1873, vol. 1, pt. 3,1873, p. 80.

3 On some points in the geology of northern Wisconsin. Wisconsin Acad. Sci. Trans., vol. 2,1874, p, 

117.

4 Op. cit., pp. 114,115.

6Ara. Jour. Sci., 3d serM vol. 8, 1874, pp. 46-56.

6Notes on the geology of northern Wisconsin. Wis. Acad. Sci. Trans., vol, 3,1876, p. 48.

7 Op. cit., p. 49.
WALCOTT/I LAKE SUPERIOR SANDSTONE. 197

ity, is of the same age as the eastern sandstone, along the shore of 

Lake Superior, east of Keweenaw Point.

A description of the Lake Superior sandstone is given by Dr. Irving 

in his account of the geological structure of northern Wisconsin that is 

very full and complete, and it will be referred to again in the summary 

of our present knowledge of that formation. 1 In the account of the 

geology of the eastern Lake Superior district tin the same volume Dr. 

Irving described the Lake Superior or Potsdam sandstone of the 

Apostle Islands and adjoining shore.2 An account of the sandstone 

as it occurs in the western Lake Superior district is given by Mr. B. T. 

Sweet in 1880.3

Dr. M. E. Wadsworth notes that the sandstone at Marquette rests 

upon the Azoic schists. That south of the Carp Eiver, in the locality 

figured by Messrs. Foster and Whitney, the sandstone strata are seen 

to abut against and overlie the vertical edges of the quartzite.4

A general account of the Potsdam sandstone series is given by Dr. 

K. D. Irving in his article on the mineral resources of Wisconsin. Of 

the Lake Superior sandstone he says:

Tho horizontal sandstone of the south shore of Lake Superior belongs unquestionably to this formation, though it is a matter of doubt whether the two sandstones do 

or ever did connect. The Lake Superior rock differs from its more southern equivalent in its red color. 5

The sandstones at the eastern end of Lake Superior, on the St. Mary's 

Eiver, were referred to the Chazy formation by Sir W. E. Logan. Dr. 

T. S. Hunt calls this view a speculation, which was shown to be untenable by the establishment of the Potsdam age of the sandstones overlying the quartzites of Wisconsin and in northern Michigan, where 

Eominger finds the upper sandstone to be overlaid by Oalciferous-Chazy 

beds."

Tin- Eastern sandstone, or that between the Keweenaw Eidge and 

eastward along the south shore of Lake Superior, is well described by 

Dr. E. D. Irviug in his account of the copper-bearing rocks of Lake 

Superior.7 This is followed by a description of the.western sandstone, 

or that occurring on the south shore of the lake, west of Keweenaw 

Point. An abstract of this report also appeared in the third annual 

report of the TJ. S. Geological Survey, 1883, pp. 89-188.

In an article on the age of the rocks ef the northern .shore of Lake 

Superior Dr. A. E. C. Selwyn states that he considers the trap and 

sandstone to be of Lower Cambrian age. He calls them all Lower 

Cambrian, which includes Potsdam and Primordial Silurian. . He holds

1 Geological structure of northern Wisconsin. Gool. Wise. Surv. of 1873-70, vol. 3,1880, pp. 1-25.

2 Op. cit., pp. 207-210. '

8 L:iko Superior Sandstone. Geol. Wise. Surv. of 1873-1879, vol. 3,1880, pp. 350-352. 

4 Notes on the geology of the iron and copper districts of Lake Superior. Camb. Mns. Comp. Zool. 

Bull., vol. 7,1880, p. 60. 

6 The mineral resources of Wisconsin. Am. Inst. Mining Eng. Trans., vol. 8,1880, p. 489.

6 Tho Geology of Lake Superior. Science, vol. 1,1883, p. 219.

7 U. S. Geol. Survey, Monograph, vol. 5,1883, pp. 351-305.
198 THE CAMBRIAN. IBUIL.W.

that there is at present no evidence whatever on the north shore of Lake 

Superior of their holding any other place in the geological series.1

This view of Dr. Selwyn's was concurred in by Prof. J. D. Whitney, 

who stated it to be the opinion held by Messrs. Foster and Whituey 

thirty years previously.2

Dr. Irviug took exception to the statement made by Dr. Selwyn that 

there is no evidence whatever of the rocks holding any other place in 

the geological series than that including the Potsdam and Primordial 

Silurian, and stated:

(1) That the copper-bearing rocks underlie unconformably, and with an immense 

unconformity, a series of sandstones holding Cambrian fossils. * * * (2) That 

the copper-bearing strata also underlie unconformably the "eastern sandstone'' of 

the south shore of the eastern half of Lake Superior. * * * (3) That the timegap between the copper-bearing series and the Huronian was too long to allow of 

our classing them together. 3

The view of Messrs. Selwyn and Whitney was also opposed by Dr. 

T. S. Hunt, who referred the basal sandstone to a pre-Cambrian group.4

In a note on Dr. Selwyn's paper, Prof. N. H. Wiuchell concurs with 

him in the sweeping affirmation that there is at present no evidence 

whatever of their (i. e., the copper-bearing rocks) holding any other place 

in the geological series than that of the Potsdam or Primordial Silurian. 

" I would also add that there is incontestible evidence that they can hold 

no other." 5

In opposition to the view of Prof. Wincheli, Prof. Chamberlin stated 

the evidence upon which the pre-Cambriau age of the copper-bearing 

series of Lake Superior is based. It is (1) the general stratigraphical 

relation indicated. This he considers to be the weakest of all. (2) 

Differences in thickness; (3) differences in constitution ; (4) unconformity ; (5) the inherent inconsistency of the view; (6) the dynamic simplicity of the view; (7) the discovery of a like series in the Grand Oanon 

of the Colorado.6

Shortly after Prof. Chamberlin's paper, Dr. M. E. Wadsworth published an article on the relations of the Keweenawan series to the Eastern sandstones. His observations differ from those of Dr. Irving and 

he claims that the Keweenawan series has no existence distinct from or 

older than the sandstone of Potsdam age. In speaking of his observations he says, « ' These observations also prove at the birthplace of the 

Keweenawan series, that formation and the Eastern sandstone were 

one and the same."7

The paper of Dr. Wadsworth was followed shortly after by one of 

Messrs. Whitney and Wadsworth on the "Azoic system and its pro1 Age of the rocks on the northern shore of Lake Superior. Science, vol. 1, 1883, pp. 11,221.

2 Geology of Lake Superior. Science, vol. 1, 1883, p. 39.

3 The copper-hearing rocks of Lake Superior. Science, vol. 1, 1883, pp! 140, 141, 359,360, 422. 

* The Geology of Lake Superior. Science, vol. 1,1883, pp. 218,219. 

6 The Lake Superior Rocks. Science, vol. 1, 1883, p. 334.

6 The copper-bearing series of Lake Superior. Science, vol. 1,1883, pp. 453-455. 

T 0n the relation of the " Keweenawan series " to the Eastern sandstone in the vicinity of Torch 

Lake, Michigan. Boston Soc. Nat. Hist. Proc., vol. 23,1884, p. 174.
WALCOTT.J MISSOURI. 199

posed subdivisions." This contains a critical review of the published 

papers upon the age of the copper-bearing rocks of Michigan, Wisconsin, 

and Canada.1

In their observations on the junction between the Eastern sandstone 

and the Keweeuaw series Messrs. Irving and Ohamberliu published a 

map of Keweenaw Point, showing the distribution of the Eastern sandstone to be confined to the southeastern side of the point, the northern 

and northwestern sides being formed of the Keweenaw series.2 They 

discuss the views held by Messrs. Jackson, Foster and Whitney, Agassiz, Kominger, and Credner upon the stratigraphic position in the geologic series of the Eastern sandstone and the sandstones of the Keweenawan series; and give also a detailed account of the contact between 

the sandstone and the Keweenaw rocks.

MISSOURI.

The first notice we have of a sandstone about the Ozark Mountains of 

southeastern Missouri is by Dr. Edwin James in 1822, who called attention to an inclined sandstone, like that of the Alleghany Mountains, 

between which and the granite there intervened a stratum of clay 

slate highly inclined and resembling the primitive clay slate of New 

England.3

This was followed twenty-nineyears later by a sketch of the geology of 

the State of Missouri, in which Mr. H. King describes what he calls the 

second magnesian limestone. Beneath this is a sandstone which he 

was inclined to correlate with the Potsdam sandstone of New York. 

The presence, however, of Lituites, Euornphalus, Pleurotomaria, Natiea 1? was opposed to this view, but the stratigraphic and lithologic 

evidence sustains the correlation. In order to explain the presence of 

the fossils he suggests that "this may be an independent formation 

not represented in New York or elsewhere, and yet nearly contemporary 

with the first evidences of organic existence there and to be associated 

with them in the same geological epoch."4

The work of the first Missouri survey proved the presence of four 

magnesiau limestones with a belt of sandstone between the third and 

the fourth, the fourth limestone forming the base of the series. Prof. 

G-. C. Swallow describes the third sandstone, above the fourth maguesian limestone, as a white saccharoidal sandstone, made up of slightly 

cohering transparent globular and angular particles of silex. It is assigned a thickness of 30 feet, and owing to its position below the third 

maguesian limestone is considered at least as old as the Calciferous 

saudrock, and there is great probability that it may prove to be beneath

1 Tho Azoic system and its proposed subdivisions. Harvard Mus. Corap. Zool. Bull., vol. 7,1884, pp. 

482-498.

^Observations on tho junction between the Eastern sandstone and tho Koweenaw series on Keweonaw 

Point, Lake Superior. U. S. Geol. Surv. Bull., No. 23,1885, pi. i.

* Geological sketches of the Mississippi Valley. Phil. Acad. Sci., Jour., vol. 2, 1822, p. 329.

4 Some remarks on the geology of tho State of Missouri. Am. Assoo. Proo., vol. 5, 1851, pp. 190,191.
200 THE CAMBRIAN. . [BULL. 81.

the Potsdam sandstone.1 In a foot-note on page 129 it is said tbat 

since the report was written Mr. Meek discovered a trilobite in the third 

magnesian limestone, which he and Dr. B. F. Shumard considered 

identical with one from the Potsdam sandstone of the Northwest. In 

the tabulation of the strata as determined in Missouri both the third 

sandstone, and the fourth magnesian limestone are included under Calciferous sandrock.2

When speaking of the geological map and the section of the rocks of 

Missouri, prepared prior to 1861, Prof. G. C. Swallow states that the 

Potsdam sandstone rests unconforinably upon the Azoic stratified 

slates of Missouri.3

The presence of the third sandstone and the fourth magnesian limestone is noted by Mr. F. B. Meek in Morgan and Miller Counties. In 

Miller County the two formations have a thickness of 33 feet and in Morgan County the third sandstone varies from 15 to 30 feet. The fourth 

maguesian limestone is assigned a thickness of 150 feet.4

On the map of Madison County, prepared by Messrs. C. J. Norwood 

and G. C. Broadhead, the geographic distribution of the rocks referred 

to the Cambrian and pre-Cambrian is delineated. 5

Below the third maguesian limestone in Madison, St. Francois, and 

Iron Counties, Prof. G. C. Broadhead found siliceous or gritstone beds 

with intercalated magnesian limestones and subjacent to these are marble beds, beneath which occur sandstones, conglomerates, and shales. 

These are numbered one, two, and three, respectively. In No. 3, beneath 

the third magnesian limestone, Lingulella lamborni, Meek occurs. On 

the St. Francois Eiver, in Madison County, the lower unaltered sandstones rest directly on the granite.6

At a deep well at the St. Louis County Insane Asylum the following 

section is referred to as beneath the third maguesiau limestone:

11. 98 feet of third sandstone.

12. 384 feet of fourth magnesian limestone.

13. 54 feet of Potsdam sandstone.

14. 245-4 feet, mostly granite, although a portion of the upper 

part may be sandstone.

15. 40 leet of granite.7

A more detailed account of the strata beneath the third magnesian 

limestone is given on pages 352-357. The fossiliferous bed is separated 

as a "Lingulagrit." In this there were observed Lingulella lamborni,

'Geology of Missouri. Silurian System. Geol. Surv. [Missouri; 1st and 2il ann. repts , parti, 

1855, pp. 128,129.

2 Op. cit., pis. between pp. 60 and 61.

3 Remarks on the Geological Map and Section of the rocks of Missouri. Am. Nat. ,vol. 5,1871, p. 541.

4 Reports on the geological survey of the State of Missouri, 1855-1871,1873, pp. 127,149.

5 Atlas accompanying Geological Survey of Missouri, Keport, including field work of 1873-1874, 

vol. 1. Jefferson City, 1874. 

0 Op. cit., p. 31. 

7 Op. cit., p., 32.
WALCOTT.J ADIRONDACK SUB-PROVINCE. 201

Orthoceras, a gasteropod, and a form resembling a cross-section of a 

coral of the genus Zaphrentis.

In a description of the southeast Missouri lead district Prof. Broadhead gives a resume" of the geology, and suggests that if the Idngula 

(Lingulella) lamborni and Scolithus should be found in the Calciferous 

group he would prefer to assign all the rocks from the lower sandstone 

to No. 1, inclusive, as Calciferous. 1 The marble of southeastern Missouri was referred in 1882 by Prof. Broadhead to the older series or 

Potsdam, and the upper series to the Upper Silurian, with the statement that Potsdam quarries are found in Madison, Iron, and Reynolds 

counties. The marble beds will be spoken of in the summary of the 

Cambrian rocks of Missouri.2

In a paper upon "The Geological History of the Ozark Uplift" Prof. 

G. C. Broadliead describes, in 1889,3 in a general way rocks referred to 

the Potsdam and the Calciferous formations. Of these he says:

The evidence is that the sandstones and magnesian limestones (Potsdam atid Calciferons) were deposited in Archcan valleys of erosion, for they generally repose 

nearly horizontally, or with slight inclination, upon the Archean. 4

EASTERN BOEDER OR ADIRONDACK SUB-PROVINCE.

This includes the area about the Adirondack Mountains of New 

York and the adjoining portions of Canada to the north.

In a report of the geological structure of the county of Saratoga, 

Mr. J. H. Steele states that a conglomerated, mass of rock is found in 

the town of Greeufleld not far from its south line, on the southeast side 

of the Kayadarosseras Mountains, resting upon the primitive rocks. 

He says:

It consists of rounded pebbles of quartz, from the size of a small shot to that of a 

man's head, united into ouo common mass by a kind of coarse ferruginous sand. It 

extends along the mountains to no great distance, but fragments of it lay scattered 

in all directions, and, indeed, are found along the whole extent of the south line of 

the town of Greenfield, and in various other places.6

Under the heading of " Coarse Siliceous sandstone" a description is 

given of an extended horizontal stratum along the west part of the 

north line of the town of Saratoga Springs, and some way into the town 

of Greeufleld:

It is a coarse, hard rock, resembling common quartz in its fracture, but it is more 

loose and granular in its structure. It is of a white color, and when heated and 

thrown into water, crumbles into a fine white saud. * * * I have been somewhat 

at a loss to know where to place this formation, but from several circumstances I am 

confident it should bo placed among the oldest of the transition class. 6

'The Southeastern Missouri lead district. Am. Inst. Mining, Eng., Trans., vol. 5, 1877, p. 102.

2 Marble of southeast Missouri. Kansas City Review, vol. 5,1882, pp. 524-520.

3 Am. Geologist, vol. 3,1889, pp. 6-13. 

"Op. cit., p. 8.

6 A report of the geological structure of the county of Saratoga. Memoirs of tho Board of Agriculture of tho State of New York, vol. 2,1823, p. 53. 

6 Op. cit.,p.54.
202 THE CAMBRIAN.

A description is also given of a Calcareous sandstone as it occurs 

on the west side of the Kayadarosseras Mountains.1 The sandstone 

referred to by Mr. Steele, and also the lower portion of the Calcareous 

sandstone, are now known to be of Upper Cambrian age.

Various references are made by Prof. Amos Eaton to the Calciferous 

saudrock (or Transition sandrock) as examined by Mm in the valley of 

the Mohawk. He also says: " Perhaps the Transition sandstone of the 

Green Mountain series may not be connected with that of theMacomb 

Mountain series."2 Most of Prof. Baton's references to this formation 

are very indefinite, and he included it with the Calciferous sandrock, as 

exposed at Little Falls in the valley of the Mohawk. That he was 

aware of its stratigraphic position is shown by the comparisons made 

between the Transition sandstone of the Green Mountains and that of 

the Macoinb Mountains, the latter now being known as the Adirondacks.

The attention of Mr. J. H. Steele was called to the oolitic formation 

about 2 miles from the village of Saratoga Springs. He described the 

occurrence of great quantities of calcareous concretions of a most singular 

structure; they are mostly hemispherical, but many of them are globular 

and vary in size from half an inch to that of 2 feet in diameter; they are 

obviously composed of a series of successive layers, nearly parallel and 

perfectly concentric, etc.3 This is the first notice of a fossil that was 

subsequently described by Prof. James Hall as GryptozoonproUferum.4 

It occurs in layers in which the Upper Cambrian or Dikelocephalus 

fauna is found a few miles west of Saratoga Springs.

In the first annual report of the geological survey of New York 

Dr. Emmons mentions a sandstone resting on the primitive rocks both 

on the Lake Champlain side of the Adirondack Mountains, at Whitehall, 

and on the western side, in the vicinity of Theresa, on the Indian River.5 

In this preliminary paper the Calciferous sandrock of Prof. Eaton and 

the subjacent sandstone are not clearly differentiated. In the second 

report, however, he separated the sandstone as the u sandstone of Potsdam." 6 His description of the rock is as follows:

I shall not enter upon its geological relations any further than to state that in 

Potsdam and other towns in which it appears it uniformly rests on the primary 

strata; and in no part of the county is there any rock which interposes itself between 

it and the Primary, so that it appears here as the oldest representative of the transition series. The identification of this rock with the sandstones along the southern 

border of Lake Ontario will be a matter of some difficulty. It is geologically below

1 Op. cit., p. 56.

* A geological and agricultural survey of the district adjoining the Erie Canal, 1824, p. 78.

3 A description of the oolitic formation lately discovered in the county of Saratoga and State of New 

York. Am. Jour. Sci., vol. 9,1825, p. 17.

4 Cryptozoon, n. g., Cryptozoon proliferum, n. sp. Description of PL VI, 36th Ann, Kep. N. Y. State 

Mus. Nat. Hist., 1884.

8 First annual report of the second geological district of New York. First annual report of the 

geological survey of New York. Albany,'1837, pp. 106,107.

6 Report of the geologist of the second geological district of New York. Second annual report of 

the geological survey of New York. Albany, 1838, p. 214.
WALCOTT.] ADIRONDACK SUB-PROVINCE. 203

the transition limestone and never in the northern district alternates with it, but 

always holds the relation of an inferior rock. 1

This rock is a true sandstone, of red, yellowish red, gray, and grayish white 

colors. It is made np of grains of sand and held together without a cement. Intermixed with the siliceous grains are finer particles of a yellowish feldspar, which do 

not essentially change the character of the sandstone, but they show the probable 

.source from which materials forming it were originally derived, viz, some of the varieties of granite. Unlike, however, most of the sandstones, it is destitute of scales of 

mica. The coloring matter of the rock is evidently oxide of iron, but unequally 

diffused through it, giving it intensity or deepness of color in proportion to its quantity. In some places it is almost wanting, which makes it, when pulverized, a good 

material for glass. The grains and particles in its composition are generally angular, 

but where it takes the character of a conglomerate, as it does in the inferior layers, 

they are frequently rounded. The thicker strata exhibit an obscurely striped appearance, owing to prevalence of certain colors in the different layers. 2

In the description of the sandstone on the Lake Champlain side in 

Essex County it is said :

This I consider the same formation I have described under the name of the "Potsdam sandstone." Its position is evidently beneath the Transition limestone and Calciferous saudrock. It is very deficient in organic relics, though not entirely destitute 

of them. It is unnecessary to repeat what has already been said of this rock; it is 

purely quartzose or siliceous in its composition and finely stratified. It dips to the 

northeast at Port Kent, at an angle varying from 5° to 10°. The places where it 

occurs along Lake Champlaiu are indicated on the map of a part of this county, to 

which I refer the reader. This rock at Keeseville has been rent in the most remarkable manner ; several fissures, the principal one of which extends nearly a mile, and 

through which the Au Sable flows, have been opened by some convulsion in nature to 

the depth in some places of 100 feet, and from 5 to 20 feet wide. Near the bottom of the 

fissure at the High Bridge, as it is called, I discovered numerous specimens of a small 

bivalve mollnsca, a Lingula. I found also, on examination, that the same fossil occurred through an extent of seventy feet at least, and so far as I could discover it was 

the only fossil inclosed in the rock. It is extremely thin and delicate, yet the shell 

is perfectly preserved, and is probably one of the oldest inhabitants of the globe, as 

the rock in which they occur is the oldest of the transition series. 3

In the second annual report of the paleontological department of the 

New York survey Prof. T. A. Conrad tabulated the formations to show 

the order of superposition and some characteristic fossils in the transition strata. On the primary occurs No. 1, formed of variegated sandstones (Potsdam sandstone of Emmons), and the olive sandstones and 

slates, characterized by Fucoides serra. These are classified under the 

Cambrian system of Prof. Sedgwick.

The base of the Lower Silurian is a gray calcareous sandstone, characterized by Lingula acuminata. This part of his table is as follows :4

LOWER SILURIAN STRATA.

Gray calcareous sandstone..................................... ..Lingula acuminata

'Op.cit.,p. 214. 

2 0p.cit.,p.215. 

3 Op. cit.,p.230.

* Second annual report of the paleontological department of the survey. Third annual report of the 

geological survey of New York. Albany, 1839, p. 63.
204 THE CAMBRIAN. [DULL.81.

CAMBUIAN SYSTEM (SEDGWICK).

. ( Olive sandstone and slate......................... ...... Fucoides serra (Brong.)

' \ Variegated sandstone (Potsdam sandstone of Ernrnuus)....... Dictuolites radians

A description of the geographic distribution of the Potsdam sandstone in Clinton County is given by Dr. Emmons in the third annual 

report of the New York State survey. He also describes its strati-, 

graphic character and appearance, and states that at Flat Rock the 

sandstone is more or less a conglomerate and coarser than at Potsdam 

or Keeseville.1

A description of the Potsdam sandstone as it occurs on the western 

side of the Adirondacks, in Jefferson County, is given by Dr. Einmons 

in his fourth annual report, as follows :2

Lying unconformably upon the primary is the Potsdam sandstone. It is therefore next in the series. It is a firmer rock, more crystalline, and less porous than 

the same rock in St. Lawrence, and especially that belonging to Potsdam.

The only fossil found in it was a small linguloid shell called Lingula 

ovata.3

The presence of the Potsdam sandstone in Lewis County is noted by 

Mr. Lardner Vanuxem, who states that the sandstone appears in the 

northeastern part of the county in low ridges, with all the characteristics 

given by Prof. Einmons, in whose district it is an extensive rock.4

The Potsdam sandstone as it occurs in Washington County, upon 

the eastern side of the mountains, is described by Dr. W. W. Mather as

a hard, siliceous sandstone, white, red, gray, yellowish, and frequently striped. It 

is well developed at Whitehall, where it has a thickness of 150 to 200 feet. It extends 

up the valley of Wood Creek in a southerly direction by Cornstock's Landing, 1 mile 

east of Fort Ann, and so on farther south, diminishing in thickness and becoming 

interlaminated with finer-grained strata of grits, slates, and shales. Some of the 

strata of this rock are covered with the most beautifully characterized ripple-marks, 

as perfect as if just formed on the sand of a sea beach, while the rock is of the most 

indurated kind of sandstone. 6

The only fossils noticed were fucoidal impressions.

The geographic distribution of the Potsdam sandstone about the Adirondacks is shown on the map of 1844 that accompanies the final report 

of the State geologists of New York. On a geological map of the Middle and Western States by Prof. James Hall 6 the main geographic distribution is indicated and a small area on the southern side of the Wisconsin River in Wisconsin is the same tint as the Potsdam area of New 

York

1 Third annual report of the second geological district. Third annual report of the geological survey of New York, 1839, pp. 231,232.

2 Fourth annual report of the survey of the second geological district of New York. Fourth annual 

report of the geological survey of New York. Albany, 1840, p. 322.

3 0p.cit.,p. 323.

'Fourth annual report of the geological survey of the 3d district. Fourth Report of the Geological 

Survey of New York. Albany, 1840, pp. 363,368.

6 Fifth annual report on the geological survey of the 1st geological district. Fifth Annual Report of 

the Geological Survey of New York, 1841, p. 102.

6 Geological map of the Middle and Western States. Geol. of New York. Report on the Fourth 

Gool. district, Albany, 1843.
WALCOTT.] ADIRONDACK SUB-PROVINCE. 205

In a tabulation of the Lower Silurian strata of the State of New York, 

published in 1842, Prof. T. A. Conrad states that the Cambrian system 

has proved to be the Lower Silurian, and he places the Potsdam sandstone at the base of the latter system, beneath the Calciferous sandstone.1

The final report of the geology of the second geological district contains a summary by Dr. Emmoiis of the characters of the Potsdam sandstone as fouud in the counties of Warren, Essex, Clinton, Franklin, St. 

Lawrence, and Jefferson, and also gives details of the formation as 

found in each county.2 A description of the formation in detail and 

also a general descriptive summary of the formation is given by Mr. 

Larduer Vauuxem as it occurs in his district, 3 and Dr. W. W. Mather 

describes it as it occurs in Washington County and in Saratoga County.4 

Prof. James Hall describes it concisely in an account of the rocks of 

New York State. In its geographic distribution the rock is known in 

Canada, on Lake Superior, and, from its position, it is probably the 

same that appears on the Mississippi Eiver mentioned by Dr. Owen in 

the report on the lead region of the northwest.5 He also identifies it 

with No. 1 of the Pennsylvania survey, or a sandstone extending through 

New Jersey, Pennsylvania, and Virginia.6

In the account of his travels in North America Sir Charles Lyell describes the Potsdam sandstone as he saw it at Au Sable Chasm, near 

Keeseville, Essex County, New York. He speaks of it as a siliceous 

sandstone:

In many places, this most ancient of the fossiliferous rocks of New York (the Potsdam sandstone) is divided into laminae by the remains of innumerable shells of the 

genus Lingula. They are in such profusion as to form black seams like mica, for 

which they were at first mistaken. With the Lingula occurs another placunoid shell 

allied ±o, if not identical, according to Prof. E. Forbes, with a fossil which occurs in 

company with a small Lingula in the lowest beds of the English Silurian series ^t 

Builth, in Brecknockshire. 7

A general account of the Potsdam sandstone is given by Dr. E. Emmons in the Agriculture of New York. It is an excellent summary of 

the general characters of the formation.8

The Potsdam sandstone of Lewis County is described by Mr. F. B. 

Hough in a general manner. He states that it thins out to an unimportant stratum as compared with the formation in St. Lawrence County; 

also that the superjacent Calciferous sandrock is represented by only a

1 Observations on the Silurian and Devonian systems of the United States, with descriptions of new 

organic remains. Phila. Acad. Sci. Jour., vol. 8,1842, pp. 229,230. 

z Geology of New York, part 2, second geological (northern) district, pp. 102-105,177-179, etc.

3 Geology of New York, part 3, third geological (central) district, Albany 1842, pp. 28,29.

4 Geology of Now York; geology of the first (southeastern) district. Albany, 1843, p. 418..

6 Geology of New York; geology of the fourth (western) geological district. Albany, 1843, p. 27. 

6 0p. cit.,p.28.

7 Travels in North America. Now York, 1845, vol. 2, pp. 131,132.

8 Agriculture of flew York, vol. 1,1846, pp. 117,1J8.
206 THE CAMBKIAN [BULL. 81.

thin layer of the fucoidal sandstone.1 In 1850 he called attention to 

cylindrical masses from 3 inches to 15 and 20 feet in diameter that occur 

in the Potsdam sandstone near Somerville, St. Lawrence County.2

The description and accompanying figure recall the Cryptozoon proliferum described by Prof. Hall from the Potsdam formation of Saratoga 

County. A year later attention was again called by Mr. Hough to the 

cylindrical masses.3 They are described as vertical cylinders from 2 

inches to 20 feet and upward in diameter, and show a concentric structure. Numerous smaller bodies, not larger than an orange, of a spheroidal stmcture are also met with in the vicinity. No traces of organic 

life were observed in the matrix. It is evident that these bodies are 

unlike the Saratoga Cryptozoon.

A more extended definition of the Potsdam sandstone was given by 

Dr. E. Emmons in 1856. He then included with it the lower sandstone 

of the upper Mississippi Valley, and No. 1 of the Pennsylvania survey.*

An excellent summary of the existing knowledge of the Potsdam 

sandstone was given by Dr. J. J. Bigsby in 1858 in a paper on the Paleozoic Basin of the State of New York. A description is given of the 

mineral characters, mode of transition, stratigraphic position, mode of 

occurrence, thickness, and paleontologic character.5

In a tabulation of the succession of sedimentary rocks Prof. Eichard 

Owen states that the Potsdam sandstone of New York geologists is considered by some English writers as belonging to a separate system, the 

Cambrian.6

The presence of the peculiar cylindrical masses in the Potsdam sandstone mentioned by Mr. Hough is also noticed by Mr. T. G. B. Lloyd in 

Jefferson County,7 but without any attempt to explain their origin or 

nature.

In a note on the geology of Port Henry, New York, Dr. T. S. Hunt 

states that the Potsdam sandstone and the basal member of the overlying Paleozoic series is well seen in a railway cut near Port Henry. 

The lower beds are massive and compact, dark bluish or iron gray, with 

lighter bands and thin, blackish, shaly layers. The only fossils observed 

were Scolithus linearis and 8. canadensis of the Potsdam of the Ottawa 

Basin.8

1 Observations on tho geology of Lewis County, New York. Am. Jour. Sci. and Agric., vol. 5,1847, 

p. 273.

2 Catalogue of miueralogica) and geological specimens received from P. B. Hough, 3d Annual Kep. of 

Regts. Univ. State Cab. Nat. Hist, 1850, pp. 32, 33.

3 On the cylindrical structure observed in Potsdam sandstone. Am. Assoc. Proo., vol.4, 1851, pp. 

352-354.

4 American Geology, containing a full statement of the principles of the science, with full illustrations of the characteristic American fossils. Albany, 1856, vol.1, pt. 2, pp. 128-132.

8 On the Paleozoic Basin of the State of New York. Part I. A synoptical view of the mineralogical 

and fossil characters of the Paleozoic strata of the State of New York. Quart. Jour. Geol. Soc., London, vol. 14, 1858, pp. 338,339.

6 Preliminary observations; general report and description by counties. (Lower and Upper Silurian). Geological reconnaissance of Indiana, made in 1859-'60. Indianapolis, 1862, p. 14.

7 Geological notes from the State of New York. Quart. Jour. Geol. Soc., London, vol. 32,1876, pp. 78,79.

8 The geology of Port Henry, New York. Canadian Nat., new ser., vol. 10,1883, p. 421,
WALCOIT.I ADIRONDACK SUB-PROVINCE. 207

A short notice of the discovery of a massive limestone superjaceutto 

the typical Potsdam sandstone containing species of the Potsdam fauna 

equivalent to the fauna of the upper horizon of the lower sandstone of 

the Mississippi Valley was made by Mr. C. D. Walcott in 1884. The 

limestone was originally referred to the Calciferbus formation.1

Mention is made of the contact between the Potsdam sandstone 

and the subjacent pre-Cambrian rocks in the vicinity of Fort Ann, 

Washington County, New York, by Mr. C. E. Hall.2

A section of the Potsdam sandstone with the superjacent limestone, 

carrying the Upper Cambrian fauna was published by Mr. C. D. Walcott in 1886 accompanied by a list of the fossils found and a comparison 

of them with the Wisconsin fauna referred to the Potsdam by Prof. 

James Hall.3

In the fifth annual report of the State geologist of Few York, in 

some field notes on the geology of the Mohawk Valley, with a map, 

Messrs. C. E. Beecher and C. E. Hall describe a section that occurs in a 

cut on the West Shore Railroad at "Little Nose, Eandall, Montgomery 

County, New York." 4 In the woodcut illustrating the section, a breccia 

that occurs unconformably beneath the Calciferous sandrock is stated 

to contain Potsdam sandstone, crystalline limestone, quartzite, etc. 

The evidence upon which the fragments of sandstone were identified as 

of Potsdam age is not given.

In a paper on a great Primordial quartzite Prof. N. H. Winchell republishes a description of the Potsdam sandstone by Dr. Emmons and 

correlates the formation with the "granular quartz "of the western 

slope of the Green Mountains and the pre-Cambrian quartzites of Wisconsin and Minnesota. 5

In a paper read before the Geological Society of America, at Washington, B.C., December 31,1890, Messrs. N. S. Shaler and H. S.Williams 

described the presence of a thin bed of shale beneath the Calciferous 

saudrock and just above a thin bed of sandstone that rests unconformably upon the subjacent pre-Paleozoic rocks. The locality is a quarry 

at Little Falls. In the shale numerous specimens of Lingulepis acuminata were found.6

CANADIAN EXTENSION.

In a report of progress of the geological survey of Canada for 1S45-'4G 

Sir W. E. Logan notes the presence of a sandstone in the Ottawa district, but is doubtful whether it represents the Potsdam sandstone, as

1 Potsdam fauna at Saratoga, New York. Science, vol. 3,1884, pp. 136,137.

*Laurontian Magnetic iron ore deposits from northern New York, accompanied by a geological map 

of Essex County. Keport of the State geologist for tho year 1884. Albany, 1885, p. 32.

3 Second contribution to the studies of the Cambrian faunas of North America. U. S. Geol. Survey, 

Bull. No. 30,1886, pp. 21,22.

4 Fifth Ann. Kept. State Geologist of N. Y., for 1885. Albany, 1886, p. 10. 

8 A Great Primordial Quartzite. Am. Geol., vol. 1,1888, pp. 173-178. 

"Unpublished.
208 THE CAMBRIAN. IBULL.SI.

it may be in the lower beds of the Calciferous.1 In a later report he 

noted the-presence of the Potsdam sandstone on the north shore of the 

St. Lawrence at Murray's Bay, 90 miles below Montreal, describing it 

as a formation consisting of white, translucent, slaty quartz-rock having an exposed thickness of 45 feet and conformably subjacent to the 

Calciferous sand rock.2

A brief summary of the lithologic and paleontologic characters of the 

Potsdam sandstones in Canada was read by Dr. T. S. Hunt before the 

American Association for the Advancement of Science in 1851.3

In an extended paper on the foot-prints occurring in the Potsdam 

sandstone of Canada, Sir W. E. Logan describes the Potsdam sandstone 

as it occurs in Canada in the St. Lawrence Valley. He states that 

The sandstone in Beauharnois Coiinty and the neighboring part of the State of 

New York is from 300 to 700 feet thick. In the lower part it contains many beds of 

conglomerate, with quartz pebbles, and it has some red layers; but towards the top 

it becomes a fine-grained, hard, white sandstone, and at the summit it is interstratified with calcareous layers, forming a passage to the rock which overlies it. 4

The description of the extention of the Potsdam sandstone between 

the Eiver of the North and Beauharnois was continued by Sir W. E. 

Logan in the report for 1851-'52.5 In the same volume Dr. Alexander 

Murray describes the sandstone along the shores of the St. Lawrence 

in the vicinity of Brockville, and also in the outcrops exposed between 

the rivers Ottawa and St. Lawrence.6

This was followed in 1854 by the account of Dr. Murray's exploration 

between Kingston and Lake Simcoe. In this region the Potsdam is 

not largely developed, the greatest thickness of it observed in any one 

place being certainly not over 40 or 50 feet, while west of Knowltou 

Lake, in Loughborough, it appears gradually to decrease in thickness, 

aiid eventually to die out altogether.7

In the summary of the work of the Geological Survey of Canada from 

its commencement to 1863, there is given a very complete description 

of the stratigraphic, lithologic, and paleontologic characters of the Potsdam, sandstone as known in Canada.8 Since that time very little has 

been published upon the formation.

deport on sequence and distribution of the formations (on the Ottawa). Geol. Surv. Canada: 

Report of progress for 1845-'46, Montreal, 1847, p. 51.

2 Report on Bay St. Paul and Murray Bay. Gool. Surv. Canada: Report of progress for 1848-'49. 

Toronto, 1850, pp. 10,11.

3 Remarks on the lithological and palooutological characters of the Potsdam sandstone. Am. Assoc. 

Proc., vol. 6,1852, pp. 271-273.

4 On the foot-prints accurring in the Potsdam sandstone of Canada. Quart. Jour. Geol. Soc., Lond., 

vol. 8,1852, p. 200.

5 Report [on country between Rividre du Nord and Beauharnois] Geol. Surv. Canada, 1851-'52. 1852. 

pp. 8-14.

6 Report [of country lying between rivers Ottawa and St. Lawrence] Geol. Survey of Canada for

1851-'52, 1852, pp. 64-67.

7 [Exploration between Kingston and Lake Siincoe.] Geol. Surv. Canada: Report of progress for

1852-'53, 1854, p. 109.

8 Geological Survey of Canada: Report of progress from its commencement to 1863. Montreal, 1863, 

pp. 87-109.
WALCOTT.] COLOKADO. 209 

WESTERN BORDER OK KOOKY MOUNTAIN SUBPKOVINCE.

This stibproviuce includes central Colorado, central and northern 

Wyoming, South Dakota and southern central Montana.

COLORADO.

The probable presence of the equivalent of the Potsdam sandstone 

of the Mississippi Valley in the Colorado range was noticed by Dr. F. 

V. Hayden in 1874. He says:

The lowest beds of sedimentary rocks are rather coarse sandstones, and conglomerate made up of water-worn quartz pebbles, with very irregular laminuo of deposition, the whole reminding one of the Potsdam group. * * * There is considerable 

variety in the aggregate of beds here, which may be regarded aa Silurian, and wo may 

conclude that tho Potsdatn group is quite well represented, aud that it is possible 

that some of the higher divisions occur. These rocks require a still more careful 

istudy, yet it is an. interesting fact to know of their existence in this locality. In 

the lower sandstones I found a species of Lingula, the present season, probably a 

Potsdam form. 1

These observations were made along William's Canon, 2 or 3 miles 

above Colorado Springs. Of the probable presence of the "Potsdam" 

in the South Park, on the north slope of Mount Lincoln, and on all of 

the surrounding high mountains he does not appear to have any doubt. 

He says:

Before going further I will state what I believe to be the age of all the limestones nnd quartzites which seem to cover the highest mountains, and in which 

most of tho valuable mines are found. I think there is no doubt that they belong 

to the Potsdam group, though I was unable to discover*any fossils. Dr. Peale found 

a few obscure forms which indicated that the group is of the same age as those next 

to tho granites in Utah, which we now know are of that age.3

While studying the geology from Denver to Colorado Springs, Dr. 

A. C. Peale examined aud measured a number of sections passing from 

various horizons in the superjaceut rocks to the Archean. In one, extending from Glen Eyrie eastward to Camp Creek, there are 40 feet of 

coarse sandstone of a grayish white, dark green, gray and brick red 

color. This series rests upon the granite ; is beneath limestones referred to the Quebec group, and is considered to represent the Potsdam 

group.3

On Trout Creek, in Bergen Park, 93 feet of sandstone is referred to 

the Potsdam.4 In a reddish sandstone superjacent to the " Potsdam" 

a number of fossils were found that were referred to the Quebec group. 

As now known this fauna is of Lower Silurian (Ordovician) age, corresponding to the Calciferous zone of the New York section. Another 

section was measured on one of the eastern tributaries of Trout Creek,

1 Report of 1\ V. Haydon, TL S. Geologist. U. S. Geol. Surv. of the Torr., 7th Ann. Kep., 1874, p. 35. 

*0p.cit.,p.41.

'Report of A. C. Poale, M. D., geologist of the South Park Division. U. S. Geol. Surv. of the Terr., 

Uh Ann. Rep., 1874, p. 202. 

<0p. cit.,p. 208.

Bull. 81 14
210 THE CAMBRIAN. IBULL.SI.

in which 67 feet of sandstone occur resting upon the granite. Of these 

sectious Dr. Peale says:

A comparison of the sections given above shows that the Potsdam group is represented by sandstones having a thickness of from GO to 80 feet, while the beds that 

represent the Quebec group are a little over 100 feet thick. 1

References to the sandstone supposed to be Potsdam are also found 

on pages 226, 236, 242, and 255.

During the field season of 1874 Dr. A. C. Peale found on Eagle River 

a series of beds resting on the gneiss and schist. From their position 

and lithologic relations to corresponding beds seen in the Colorado 

Range in 1873 the lower layers are referred to the Potsdam group. It 

is represented by a bed of white quartzite.2

A reference to the probable occurrence of the Potsdam horizon upon 

the eastern side of the Colorado Range is made by Mr. Arnold Hague, 

in his general description of the geology of the range. From the fact 

that a sandstone occurs in the Black Hills, and contains fossils of a 

Primordial type, he thinks the sandstone occupying a similar stratigraphic position in the Colorado Range will be found to contain the 

same fauna.3

On the geological map of Colorado, published by Dr. Hayden in 1877, 

the quartzite and the limestone referred to the Potsdam series are included with the Silurian, and their geographic distribution is merged 

with the latter on the map.

In his synopsis of the geological formations found in Colorado Dr. F. 

M. Eudlich tabulates tke localities and formation of the "Potsdam 

group." 4

When describing the Paleozoic rocks of the Mosquito Range in central Colorado, Mr. S. F. Emmons states that the Cambrian is represented 

by quartzites passing gradually upward into calcareous shales, with 

limestones of probably Silurian age above, the aggregate thickness of 

the two being about 400 feet.5 In the tabulation of the Mosquito section the Cambrian white quartzite is given a thickness of from 150 to 

200 feet before passing into calcareous and argillaceous shales above.6 

The only fossil remains found in this series occur in a bed of greenish 

chloritic slates on the east flank of Quandary Peak, about a mile above 

the Monte Cristo mine. They belong to the genus Dikelocephalus and 

resemble closely Dikelocephalus minnesotensis of the Potsdam formation. From analogy with other sections Mr. Emmous thinks it safe to 

assume that the fossiliferous shales occur above the main body of 

quartzite and near the base of the transition series.7

J Op. cit., p. 209.

2 Keport on Middle Division. (Stratigraphy-Paleozoic formations). U. S. Geol. and Geog. Survey of 

the Terr., Ann. Kep. for 1874,1876, pp. 110, 111.

s Hague, Arnold, and S. IJYEinraons. Descriptive geology U.S. Geol. Expl. of the Fortieth Par.; 

Clarence King, vol. 2, 1877, p. 29.

4 Keport of F. M. Eudlich, geologist of the White Kiver Division. TJ. S. Geol. Surv. of the Terr., 

10th Ann. Rep., 1878, p. 130.

8 Geology and mining Indus try of Leadville, Colorado. MOD. U. S. Geol. Survey, vol. 12,1886, p. 55.

« Op. cit., p. 57. 7 Op. cit., p. 60.
WALCOTT.J WYOMING. 211

WYOMING.

As geologist to Capt. Reynold's expedition to the headwaters of the 

Missouri and Yellowstone Rivers, Dr. F. V. Hayden identified,_in 1861, 

the fossiliferous " Potsdam " sandstone of the Black Hills, and considered a sandstone holding the same relative position and exhibiting the 

same lithologic characters on the slopes of the Big Horn Eange as the 

same formation. It is further stated that " a few thin layers of fine 

calcareous sandstone were observed filled with fossils characteristic of 

this period." 1

From the Big Horn Eangehe crossed to the Laramie Eange. At the 

head of the La Bonte" Creek he noticed a bed resting discordantly upon 

Azoic slates 50 to 100 feet in thickness, holding the same position and 

possessing the same lithologic characters it reveals at other localities.

I could discover no fossils in it at this point, but I am confident that this bed represents the Potsdam sandstoue. This rock (the Potsdam) is more or less changed by 

heat from beneath, but I was able to trace it continuously from the source of the 

Chugwater Creek to the source of Cache la Poudre, a distance of over 100 miles. It 

was also seen along the eastern slope of the Wind River Mountains, but did uot contain any organic remains. 2

A more extended account of the character of the Primordial sandstone of the Eocky Mountains was published by Dr. Hayden in 1862.3 

It is accompanied by a description of the species of fossils found in the 

Black Hills and the Big Horn Mountains and further reference to it 

will be found in the account of the Cambrian rocks of Wyoming.

All of the essential part of Dr. Hayden's article of 1861 was reprinted 

in an article on the Geology and Natural History of the Upper Missouri, which appeared in 1863.4 This essay is, as stated by the author, 

the substance of a geological report made by him to Capt. Eaynolds on 

the exploration of the Yellowstone and Missouri Eivers. The latter 

report was issued in 1869, accompanied by a large map, dated 1859-'60, 

upon which the geographic distribution of the formations identified by 

Dr. Hayden are delineated. Within the present area of Wyoming a 

narrow belt of the " Potsdam " sandstone is represented as entirely surrounding the Big Horn Mountains, and as forming a continuous band 

with that along the eastern side of the Wind Eiver Eange and an interrupted belt on the western side of the latter range. The two mountains now known as the Wyoming Mountains also had a narrow band 

of " Potsdam " sandstone about them. To the north this band is represented as continuing westward across the Big Horn Eiver, then north 

on the western side of the Yellowstone Lake region as far north as Beaver Eiver, where it is interrupted. Several mountains directly north

1 Sketch of the geology of the country about the headwaters of the Missouri and Tellowstono Kivers 

Am. Jonr. Sci., 2d ser., vol. 31,1861, p. 234.

2 Op. cit.,p.234.

3 The Primordial Sandstone of the Eoclcy Mountains in the Northwestern Territories of the United 

States. Am. Jour. Sci. 2d ser., vol. 33,1862, pp. 68-79. Canadian Jour., n&w ser., vol. 7,1862, pp. 149-151.

4 On the Geology and Natural History of the Upper Missouri. Am. Philos. Soc. Trans,, voj. 12, ntw 

ser., 1863, pp. 1-218.
212 THE CAMBRIAN. [BULL. 81.

of the Yellowstone Lake region are represented as surrounded by the 

same formation.1

At the South Pass of the Wind River Mountains Dr. Hayden found 

the granites occupying a very restricted area and extending from them 

a large thickness of "Potsdam" sandstone containing Obolellanana 

and a Lingula. 2

Prof. F. H. Bradley in 1873 identified the " Quebec group " by the 

presence of Conocoryphe and Dikelocephalus in limestones upon the 

flanks of the Teton range of mountains. At one of the outcrops of 

these limestones " they are immediately underlaid by about 300 feet of 

partly compact, partly shaly, glauconitic sandstones, which are evidently equivalent to the so-called" Kuox sandstones of Safford, which 

form in Tennessee, the lower part of the Quebec group. No fossils 

were seen in these beds. They are apparently unequally distributed, 

since no corresponding beds appear along the canon of West Teton 

Creek. Beheath them, and often present when they are absent, we 

generally find from 50 to 75 feet of a very compact ferruginous quartzite which must represent the Potsdam, though this also, is sometimes 

wanting." 3 In a diagram of a section extending from Henry's Fork 

through the Teton Mountains the so-called Quebec group and Potsdam 

quartzite are represented on each side of the range, the quartzite resting directly on the granite.*

The preliminary paleontological report of Mr. F. B. Meek refers the 

beds containing fragments of Conocoryphe and Dikelocephalus, found 

on the west base of Big Horn Mountains by the Hayden survey in 1872, 

to the Potsdam or Primordial zone. 5

In speaking of the Paleozoic rocks of the Laramie Hills, Mr. Arnold 

Hague states that all paleontologic evidence obtained from these beds 

would tend to show that they belong to the Coal Measure limestone.6

The strata along the eastern slope of the Wind River Mountains referred to the Potsdam by Dr.Hayden were studied by Prof. T. B. Coinstock while geologist of Capt. W. A. Jones's expedition to northwestern 

Wyoming. He found the sandstone closely resembled that described 

by Prof. J. D. Whitney in Wisconsin. The local peculiarities of this 

sandstone and its associated rocks as described in the Mississippi Valley and New York are strikingly repeated in the Kocky Mountain 

region. The greatest thickness of the sandstone in the region of the

1 Geological report of the Exploration of the Yellowstone and Missouri Rivers. Under the direction 

of Capt. W. V. Raynolds, 1859-'60, Washington, 1869, p. 144, map.

2 Report of 3?. V. Hayden (on the geological survey of Wyoming.) U. S. Gaol. Surv. of the Terr., 

4th Ann. Rep., 1871, p. 33.

3 Report of Frank H. Bradley, geologist of the Snake River division. U. S. Geol. Surv. of the Terr., 

6th Ann. Rep., 1873, p. 216.

"Op. cit., p. 218.

B Preliminary paleontological report . . . with remarks on the ages of the rocks, etc. U. S. Geol. 

Survey of the Territories, embracing portions of Montana, Idaho, Wyoming.and Utah ; 6th Ann. Rep. 

1873, p. 431.

G Do8criptive geology, TJ. S. Geol. Expl.of the Fortieth Par.; Ciarence King,vol. 2, p. 76. Washington, 1877.
WALCOTT.l WYOMING. 213

Wind River Mountains is about 200 feet. All the beds bear evidence 

of deposition in shallow seas or upon beaches or sand flats. 1

Under the head of Quebec group, Prof. Comstock describes some 

calciferous layers and dolomitic limestones that are conformably superjacent to the sandstone. In them he found a species of Theca ?, a trilobite of the genus Dikelocephalus and Orthis tritonia"} Fragments of 

other fossils too imperfectly preserved for identification were found.2

If the identifications by Prof. Comstock of the species found in the 

limestone are correct, that portion, of the limestone containing them 

must be referred to the Upper Cambrian zone. On the map accompanying the report the "Potsdam" formation is represented along the 

entire eastern margin of the Wind Eiver Mountains and along the western central portion of the range. A narrow belt of it surrounds Creek 

Mountain in the northeast of the Snake Indian Reservation, and the 

Wyoming Mountains to the northwest of the Wind River Range.

The southern portion of the Sweetwater district in the Wind River 

Range was visited by Dr. F. M. Endlich in 1877. He found a Lingula, 

probably Lingula prima, and estimated the thickness of the entire series 

as varying between 180 and 320 feet.3 He refers to the Oalciferous 

group a thin series of sharply bedded strata composed of blue limestones and blue and yellow dolomite and locally of oolitic dolomite, 

altogether having a thickness of about 250 feet.4 These strata are correlated with those containing Dikelocephalus, etc., discovered by Prof. 

Comstock in 1874.

The Teton Mountain district was studied by Prof. Orestes St. John 

in 1877, and in his report he refers to the work of Prof. Bradley in 1872. 

Very little is added to the information given by Prof. Bradley of the 

lower quartzite series, but an important advance is made in the classification of the rocks of the district by the division of Prof. Bradley's 

Quebec group into the Upper and Lower Quebec limestone. The Lower 

Quebec limestone, carrying Conocoryphe and Dikelocephalus, is described in detail and separated from the upper limestone carrying 

Raphistoma, etc.5

The line of separation of these two limestones is the line between the 

Cambrian and Silurian (Ordovician) Systems, and reference will be made 

to it under the description of the Cambrian rocks of Wyoming.

Prof. St. John also studied the Buffalo Fork Mountain, east of the 

Tetou Range, and found there the same succession of beds as in the 

Teton section. Numerous fossils were collected from the limestone overlying the quartzite.6

1 Geological report. Report upon tho reconnaissance ot northwestern Wyoming, made in the summer of 1873, by William A. Jones. 1874, pp. 107,108.

a Op. cit., p. 110.

3 Report on the geology of the Sweetwator district. U. S. Geol. Surv. of tho Terr., llth Ann. Rep., 

1879, p. 71.

* Op. cit., p. 72.

6 Report of the geological field-work of tho Toton Division. TJ. S. Geol. Sarv. of the Terr,, llth Ann. 

Rep., 1879, pp. 481-483.

6 Op. cit., p. 469.
214 THE CAMBKIAN. [BULL. 81.

In his report on the geology of the Wind Eiver district, made in 1883, 

Prof. St. John describes the geology of the Gros Yentre Eange, accompanying it with two plates of sections across the range at various 

points.1 On the map accompanying the volume the geographic distribution of the strata referred to the Silurian is delineated. He also 

describes the out-crops of the strata on the northwestern and northeastern sides of the Wind Eiver Eange, that he refers to the Silurian.2 

Eeference to Prof. St. John's sections will be made in describing the 

Cambrian rocks of the Wind Eiver and Gros Veutre Eanges.

On the map accompanying the twelfth annual report of the Hayden 

survey, issued in 18S3, the geographic distribution of the strata referred 

to the Silurian in the Sweetwater Eange, the Wind Eiver Eange, the 

Gros Ventre Eange, and the Teton Eange is shown. The Silurian includes the quartzite referred to the Potsdam, the Cambrian limestone 

referred to the Lower Quebec by Prof. St. John, and the Calciferous 

referred by him to the Upper Quebec. This map was compiled from the 

work of Messrs. Peale, St. John, and Endlich. There is also a special 

map showing the district reported on by Prof. St. John in 1883.

DAKOTA.

The presence of evenly bedded sandstones about the Black Hills was 

noted as early as 1822 by Dr. Edwin James, who represented them 

upon a diagrammatic section, extending from the Alleghany to the 

Eocky Mountains. He undoubtedly confused the sandstones of the 

Trias with those of the Cambrian ; but it is one of the earliest recorded 

illustrations of the mode of occurrence of the sandstone in this region. 

That he did not penetrate to the interior portion of the hills is evident, 

as his section represents the sandstone extending in level horizontal 

layers entirely across the area occupied by them.3

In 1856 Mr. H. Engelmann published a description of the rocks of the 

Black Hills. The strata next to the granitic nucleus are described as 

" more or less altered sandstones and limestones, dipping in various 

directions and degrees. Most of the sandstones are fine grained, light 

yellowish red, and do look much like metamorphic, but some show the 

transition into a siliceous rock." 4 Not far from camp 56 he found a 

friable sandstone made up of coarse square grains of granite, apparently deposited after the formation of the igneous rocks. Near camp 

58 the sandstone is light yellowish red and tine grained. There is also 

a gray variety, above which is a layer of a dark red sandstone, coarse 

grained, soft, and highly micaceous.8 This is the sandstone in which 

Dr. Hayden subsequently found the Upper Cambrian fauna.

1 Report on the geology of the Wind Eiver district. TJ. S. Geol. Surv. of the Terr., 12th Annual 

Report, 1883, p. 208. 

*0p. cit., pp. 251-253.

3 Geological sketches of the Mississippi Valley. Phil. Acad. Sci., Jour., vol. 2, pt. 2,1822, pp. 320-329.

4 Report of a geological exploration from Eort Leavenworth to Bryan's Pass, made in connection with 

the survey for a road from Port Rileyto Bridger's Pass, under Bryan. Rept. Sec. of War, Appendix H, 

1850, p. 508.

6 Op. cit., p. 510.
WALCOTT.] DAKOTA.

In notes explaining the second edition of a geological map of Nebraska and Kansas in 1858 Dr. F. V. Hayden1 states that tbe existence 

of the Potsdam sandstone on the eastern slope of the Eocky Mountains 

was discovered during Lieut. G. K. Warren's expedition to the Black 

ilills in the summer of 1857.

In March, 1858, Messrs. Meek and Hayden presented a paper to the 

Academy of Natural Sciences, Philadelphia, containing "some remarks 

on the geology of the Black Hills and portions of the surrounding country." In this a section of the formations is given, in which the " Potsdam" sandstone is given a thickness of 30 to 50 feet and is said to contain Lingula, Obolus ?, and fragments of trilobites.2 The sandstone is 

described as of a reddish and grayish color, composed of angular grains 

of quartz, cemented by siliceous and sometimes small portions of calcareous matter. The fossils then identified were Lingula antiqua Hall, great 

numbers of a small shell similar to L. prima Conrad and fragments of 

trilobites.3 The information contained in this first paper by Messrs. Meek 

and Haydeu was also published in the American Journal of Science,4 the 

Canadian Naturalist (vol. 3, 1858, pp. 182-193), the report of the Chief 

of Engineers to the Secretary of War, 1858,5 the American Journal of 

Science (vol. 25, 2d ser., p. 439,1858), the Proceedings of Philadelphia 

Academy of Science (vol. 10, p. 139,1859), and in a reprint of the Preliminary Eeport of the Exploration of Nebraska and Dakota, issued in 

1875, which is the official account of Lieut. G-. K. Warren's exploration 

transmitted to the Chief of Engineers.

In a paper on the Primordial sandstone of the Rocky Mountains and 

Northwestern Territories of the United States Dr. Haydeu describes 

the sandstone he referred to the Potsdam in the Black Hills in considerable detail, as follows :6

3. Variegated sandstone, of pray and ferruginous red color, composed chiefly 

of grains of quartz and particles of mica, cemenled with calcareous matter. 

Some portions of the hed are very hard, compact, siliceous; others a coarse 

friable grit, others a conglomerate. Fossils: Linyidaprima, L. antiqua, Obolella iiana, and fragments of a trilohite, Arionellits? oweni. . . 50 to 80 f.

4. Stratified azoic rocks standing in a vertical position for the most part.

The "Potsdam" sandstone is again described by Dr. Hayden in 

1863,7 and in the following year he published, in connection with Mr.

1 Explorations under the War Department; explanations of a second edition of a geological miip of 

Nebraska and Kansas, based upon information obtained in an expedition to the Black Hills under 

command of Liont. G. K. Warren. Am. Jour. Sci.. 2d sor., vol. 20,1858, pp. 276-278.

3 18oino remarks on the geology of the Black Hills and portions of the surrounding country.] Phil. 

Acatf. Sci., Proc., vol. 10,1859, p. 44.

3 Op. cit.,p.49.

4 Explorations under the War Department; explanations of a second edition of a geological map of 

Nebraska and Kaunas, based upon information obtained in an expedition to tho Black Hills under 

command of Liout. G-. K. Warren, Top. Engr., TJ. S. A. Am. Jour. Sci., 2d sor., vol. 20, ]858, p. 276.

 Catalogue of the collections in geology and natural history obtained by the expedition iiudor command of Lieut. Gr.K. Warren. Appendix to Kept. Sec. of War in Kept, of Topog. Eng. for 1858. (Koprint edition of 1875, pp. 59-125. Map.)

°Tlie Primordial sandstone of the Rocky Mountains in the Northwestern Territories of tho United 

States. Am. Jour. Sci., 2d sor., vol. 33,1362, p. 70.

7 On the geology and natural history of the "Upper Missouri. Am. Phil. Soc. Trans., vol. 12, new 

eer., 1863, pp. 36-38.
216 THE CAMBEIAN. [BULL. 81.

Meek, the description of tbe fossils lie found in the Black Hills during 

the expedition of 1858. They are Lingulepis pinnqformis, L. prima, 

Obolella nana, and Agraulos sp.1

A general description of the sandstone of the Black Hills is given by 

Prof. N". H. Winchell in his report to Capt. William Lndlow, and the* 

geographic distribution of the outcrop in the southern portion of the 

Black Hills is shown on the accompanying map.2 In the same report 

Prof. E. P. Wbitfield 3 describes Obolus pectenoides, a new species of 

brachiopod, and also figures Lingulepis pinnaformis.

The report of Mr. Henry Newton on the geology of the Black Hills 

contains a detailed description and full discussion of the strata referred 

to the Potsdam sandstone. This will be again referred to in the summary of our knowledge of the Cambrian rocks of the BlackHills.4 From 

the paleontologic portion of the report we learn that the entire fauna 

of the Black Hills below the Carboniferous is Primordial, and Prof. R. 

P. Whitfield states it closely resembles that from Wisconsin, and although the species are nearly all distinct the generic facies is the same 

throughout.6

In 1888 Prof. F. R. Carpenter published a series of notes on the geology of the Black Hills, in which he criticised some of Newton's views, 

and also advanced some theoretical considerations of interest in relation to the original deposition of the sediments forming the Potsdam 

group.6

SOUTHWESTERN SUBPROVINCE.

This includes the areas of Texas and Arizona.

TEXAS.

The presence of Silurian rocks in Texas, subsequently referred to the 

Primordial, was announced by Dr. F. Eoemer in 1849.7 In tlie same 

work he describes from the lower portion of the section Lingula acutangula (p. 420) and Pteroccphalia sancti-sabce (p. 421).

On the .map accompanying this volume the entire Paleozoic series is 

included under one color, on the northern side of the granitic band, 

northwest of Austin.

1 Paleontology of the Upper Missouri; a report upon collections made principally by the expedition 

under command of Lieut. G. K, Wan-en in 1855-'56. Invertebrates. Smithacuian Contributions No. 

172,1864, pp. 2-10.

2 Geological report of a reconnaissance of the Black Hllis of Dakota, made in the summer of 1874 by 

Captain William Ludlow. Report of the Chief of Engineers, Appendix PP, 1876, p. 1170.

3 Description of now fossils. Report of Geological Reconnaissance of Black Hills. A ppendix PP of 

Report of Chief of Engineers, 1876, pp. 1202,1203. 

"Geology. Section IV. The Silurian. The Potsdam sandstone. U. S. Geog. and Geol. Surv. of tho 

Rocky Mountain region, J. W. Powell in charge; report on the Black Hills of Dakota. 1880, pp. 

80-107.

5 Paleontology of the Black Hills of Dakota. Report on the geology and resources of tho Black Hills

of Dakota. 1880, pp. 329,330.

6 Notes on the geology of tho Black Hills. Preliminary Rept. Dakota School Mines on the Black 

Hills of Dakota, 1888, pp. 11-52.

7 Texas. Mit besondorer Riicksicht auf deutsche Auswandornug und die physichen Verhiiltnisse 

des Landes nach eigener Beobachtung geschildert. Bonn, 1849.
WALCOTT.J TEXAS. 217

A more extended account of the geology and the paleontology was 

published by him in 1852, in which he notes the occurrence of Silurian 

rocks in Llano County, on the San Saba River (p. 7); and describes 

and illustrates Lingula acutangula (p. 90), Pteroceplialia sanotl sabcc (p. 

92), and the genus Pterocephalia. Attention is called^ by notes and 

figures to two undescribed species of trilobites. 1

In a letter addressed to the Secretary of the St. Louis Academy of 

Sciences in 1859 Dr. B. F. Shumard states that he had discovered in 

Burnet County, Texas, an extensive development of Lower Silurian 

rocks, equivalent to the Potsdam sandstone and the Calciferous sandrock of the New York system. The Potsdam sandstone is filled with 

trilobites belonging to the old genus Arionellus, with Obolus and Lingula, and a small Orthis, and it rests directly upon the granite. Above 

the Potsdam we have beds which appear to represent the third magnesian limestome and second magnesian limestone of the Missouri survey.2 Two years later Dr. Shumard published a more detailed account 

of the Primordial zone of Texas, accompanied by a number of sections 

measured in Burnet County, and a description of new species of fossils 

from limestones referred to the Primordial. Under the heading of "Potsdam sandstone" three sections are given; one, 5 miles northwests of 

the town of Burnet, has a thickness of 275 feet. In this fossils were 

abundant in the upper portion, just beneath the Cretaceous limestone, 

as well as in the lower beds. The base was not seen. This section is 

made up almost entirely of limestones, as are the other two sections 

mentioned.3

Dr. Shumard states that the Potsdam sandstone is also finely displayed in the southern part of San Saba County and around the margins of the granite districts of Llano. "The fauna of this division of 

the Primordial zone of Texas is very analogous to that of the Potsdam 

sandstone of Iowa, Wisconsin, and Minnesota." The genera identified 

are: "Dikelocephalus, Bathyurus, Arionellus, Conocephalites, Agnostus, Liugula, Discina, Orthis, Camerella, Obolus, and Capulus, all of 

which genera have been discovered in the Primordial sandstones of the 

northwest except Agnostus and Camerella."4 In the latter part of the 

paper six new species were described, and a species of Camarella and 

one of Oapulus mentioned. In a letter to M. Barrande, dated September, 1860, Dr. Shumard describes in a general way the Primordial rocks 

of Texas as seen along the Colorado River in Burnet County.5

Attention was called in 1874 to the presence of a sandstone in Organ 

Mountains, close to the city of El Paso, in southwestern Texas, by Mr.

1 Die Kreiclobildungen von Texas mid ihro organischon EinscMusse. Bonn, 1852, pp. 92, 93.

2 Letter toucliing the lato discovery of Lower Silurian rocks, equivalent to the Potsdam sandstone 

and Calciforous sandrock of the New York system, in Burnet County, Texas. Trans. Acad. Sci. St. 

Louis, vol. 1,1859, pp. 672, 673.

8 The Primordial zone of Texas, with descriptions of new fossils. Am. Jonr. Sci., 2d sor., vol.32, 

1861, pp. 216, 217.

4 Op. cit., pp. 217, 21?.

* Letter on the Primordial of Texas. Soc. geol. France, Bull., 2« s6r., vol. 18,1861, pp. 218,219.
218 THE CAMBRIAN. [BULL. 81.

W. P. Jenney. He states that the quartzite rests upon a coarse feldspathic granite, and passes upward into sandstone, filled with Scolitlius 

linearis, which he identified as the Potsdam sandstone. The superjacent 

formation is a crystalline limestone identified as calciferous. It contains several species of fossils resembling Archseocyathus, and rarely a 

gasteropod, like Pleurotomaria.1 In commenting upon the statements 

of Mr. Jeuney, Prof. J. S. Newberry says:

Now it appears there are found in the Rio Grande Valley the crystalline baserocks overlaid in succession by the Potsdam and Primordial, the Trentou, Hudson, 

Upper Silurian(?), and Carboniferous, just as they occur in the Northern and Eastern 

States. * * * It would seem as though the Orgau Mountains had formed one 

border, and the New York and Canadian highlands the other, of the great Paleozoic 

invasions of the sea. 2

A section of the strata referred ia 1874 to the Potsdam by Mr. S. B. 

Buckley, at Packsaddle Mountain, in Llano County, gave a thick ness of 

385 feet of alternating limestone and sandstone, beneath which occurs 

a massive bed of reddish brown sandstone 326 feet in thickness. Numerous genera of Primordial fossils were found, characteristic of this horizon.3 Other references are made to the occurrence of the Potsdam 

sandstone at various localities in this county. In the report for the 

following year Mr. Buckley refers to the occurrence of sandstones of 

the Potsdam period in Mason and Meuard Counties. He also calls 

attention to the probable presence of rocks of Silurian age at the base 

of the Organ Mountains at Fort Bliss, near the town of El Paso.4

A preliminary report of a reconnaissance of a portion of the Paleozoic area of central Texas was made by Mr. 0. D. Walcott in 1884. A 

measured section of the strata referred to the Cambrian on the west 

side of Honey Creek Valley gives 245 feet of sandstone and 625 feet of 

limestone, all marked by the presence of an abundant Upper Cambrian 

(Potsdam) fauna. The upper beds of the limestone become compact, 

hard, and have a little included cherty matter. The Cambrian fauna 

terminates here, as far as observed, and it is not until over 1,000 feet of 

limestone are passed through that recognized fossils again occur. The 

fauna is then of the type of the Calciferous group.5 The text is accompanied by a diagrammatic section of Packsaddle Mountain, that illustrates the unconformity between the Llano group and the strata referred to the Potsdam or Upper Cambrian. This gave a total thickness of 605 feet for the formation, with a massive sandstone 205 feet in 

thickness at the base.6

The latest addition to our knowledge of the Cambrian rocks of Texas

1 [Recent explorations in the Geology of Texas.] New York Lyceum Nat. Hist. Proc., vol. 2,1874, 

p. 69.

2 .Remarks on geology of Western Texas. New York Lyceum Nat. Hist.. Proc. vol. 2,1874, p. 70. 

'First annual report of the geological and agricultural survey of Texas. Houston, 1874, p. 73.

4 § wml auuual report of the geological aM agricultural survey of Texas. Houston, 1876, p. 10.

"Notes on Paleozoic rocks of Central Texas. Am. Jour. Sci., 3d ser., vol. 28,1884, p. 433. 

«0p. cit.,p.432.
WALCOTT.] ARIZONA. 219

is by Prof. T. B. Corastock. 1 He divides the rocks referred to the Cambrian into the Hickory series (Lower Cambrian 1?), the Eiley series 

(Middle Cambrian *?), and the Kateincy (Potsdam) series (Upper Cambrian ?). The supposition that the Lower Cambrian and Middle Cambrian are represented is based upon the presence of certain beds beneath 

the fossilit'erous Upper Cambrian. He considers that the Hickory beds 

have altogether a thickness of 200 to 250 feet. The maximum thickness of the Eiley series is probably 300 to 400 feet. The upper or Katemcy series is divided into, Division A, or the Potsdam sandstone, 

thickness 00 to 140 feet; Division B, the Potsdam flags, probable thickness 50 feet; Division 0, the Potsdam limestone, 200 feet.

ARIZONA.

As geologist of Lieut. J. 0. Ives's expedition to the Colorado Eiver 

of the West, Prof. J. S. Newberry was the first one to recognize the 

presence of a sandstone resting upon the Archean granite in the "Big 

Canon" of the Colorado. A diagrammatic cross-section of the canon 

represents the "Potsdam" sandstone uncoufo.rmably snperjaceut to 

the granite and conformably subjacent to strata doubtfully identified 

as Silurian.2 In the text it is said "the Potsdam (?) sandstone which 

is largely developed in the Great Canon is a coarse siliceous rock that 

must have been derived from the erosion of land at no great distance." 3

A section at Diamond Creek, as described by the same author, includes a conglomerate 3 feet in thickness resting on the granite, above 

which occurs 820 feet of sandstone. Of the upper beds of the sandstone, No. 10 of the section, Prof. Newberry says:

The foliated sandstones of No. 10 have an indescribable look of antiquity. They 

are usually fine grained and hard, the lighter ones drab or gray, speckled with dark 

red. The shales above and below these sandstones are very soft red or green mudstones, containing great numbers of cylindrical bodies, which resemble the casts of 

worm holes.

Nos. 12 and 13 are coarse siliceous rocks, having the same appearance of extreme 

ago as No. 10, but much coarser aud more massive. The lithological characters of 

these strata are strikingly like those of much of the Potsdam sandstone of the exposures I have examined of that rock on Lake Superior aud in Canada. * * * Iii 

the absence of fossils, whatever conclusions may be arrived at in regard to the ago 

of these sandstones must be in some degree conjectural and liable to modification by 

the discovery of new facts; yet the evidence is in a good degree satisfactory that 

they are the equivalent of the Potsdam sandstone of the New York geologists. The 

indications of this identity are found in their great relative antiquity and in their 

lithological characters. 4

Attention is called to the resemblance of these sandstones to those 

of the Black Hills which occupy the same relative stratigraphic posi1 A preliminary report on tlio geology of the central mineral region of Texas. 1st Ann. Rep. Gool. 

Surv. of Texas for 1889, 1890, pp. 285-289.

2 Geological report. Report upon the Colorado River of the West, expl. in 1857-'58 by Lieut. J. C. 

Ivos. Part ill, 1801, p. 42.

"Op. cit.,p. 47.

4 Op. cit.,p.56
220 THE CAMBRIAN. IBCLL.PI

tion, and which contain the Potsdam fauna, as identified by Dr. 

Hayden.1

When describing the section of the Grand Caiiou of the Colorado 

where it passes through the Kaibab plateau, Maj. J. W. Powell states 

that the summit of the section was formed by Carboniferous limestone. 

This extends from the edge of the plateau down 3,500 feet, and beneath 

it occurs 1,000 feet of conformable rocks of undetermined age. These 

in turn extend down to the unconformity between them and the subjacent 10,000 feet of strata that were subsequently referred to the Grand 

Canon group. At the close of the same paragraph, in speaking of the 

latter series of rocks, he says :

The beds themselves are not conformable to the overlying Carboniferous rocks; 

that is, the Carboniferous rocks are spread over their upturned edges. 2

It thus appears that all of the strata down to the unconformity wore 

referred to the Carboniferous. This includes the series of sandstones 

referred to the Potsdam by Dr. Newberry.

As the result of his studies of the lower strata of the Colorado Canon 

region at Diamond Creek and at the mouth of the canon, Mr. G. K. Gilbert in 1874 designated the series of sandstones referred to the Potsdam 

by Newberry, as the Tonto group, and considered it to belong to the 

Primordial division of the Silurian.3 The data for this conclusion were 

published in the following year.4

The section at the mouth of the Colorado has 80 feet of vitreous 

sandstone resting unconforinably upon the granite, and COS feet of 

shales alternating with limestones between the sandstone and a superjacent massive limestone.5 At the mouth of the Kanab Creek 100 feet 

of green arenaceous and micaceous shales occur between the superjacent massive gray limestone and the level of the river.6 From the 

stratigraphic position of the Tonto sandstone and shales and the presence of a species of the genus Cruziana he was led to conclude that the 

Tonto group is certainly Lower Silurian in age. and probably Primordial.7

The section of the Tonto series at the mouth of the Grand Canon was 

measured more in detail by Mr. A. E. Marvine in the same year. He 

traced 8 the formation to the south and southeast along the margin of

1 Op. cit., p. 57.

2 Exploration of the Colorado River of the West and its tributaries, explored in 18C9,3870,1871, and 

1872. Washington, 1875, p. 212.

3 On the age of the Tonto sandstone. (Abstract.) Washington Phil. Soe. Bull., vol. 1,1874, p. 109.

4 Report on the geology of portions of Nevada, Utah, California, and Arizona examined in the ynars 

1871 and 1872. Keport on Geog. and Gool. Expl. and Survey west of the 100th merid., in charge of 

Lieut. Geo. M. Wheeler, vol. 3, Geology, 1875, pp. 18<H86. Report oil the geology of portions of New 

Mexico and Arizona, examined in 1873. Ibid., vol. 3,1875, pp. 521,522.

6 Report on the geology of portions of Nevada, Utah, California, and Arizona examined in the years 

1871 and 1872. Report on Geog. and Geol. Expl. and Survey west of the luOth merid., in charge of 

Lieut. Geo. M. Wbeeler, vol. 3, Geology, 1875, p. 163.

6 Op. cit., p. 162.

'Op. cit., pp. 185,186.

8 Report on the geology of route from St. George, Utah, to Gila River, Arizona, examined in 1871. 

Rept. on Geog. and Geol. Expl. and Surv. west of 100th mfirid., in charge of Lient. Geo. M. Wheeler, 

vol. 3, Geology, 1875, p. 199.
WALCOTT.J PALEONTOLOGY UPPER MISSISSIPPI. 221

the plateau that extends southward from the Grand Canon. The geographic distribution of the formation ia indicated on the atlas sheets 

published by the Wheeler survey in 1874.

When describing the sedimentary groups of the Plateau province 

Mnj. Powell accepted the name Ton to group, proposed by Mr. Gilbert, 

but did not agree with him in considering the strata to be of Silurian 

age. From geological considerations he was inclined to consider the 

Ton to group as forming the base of the Carboniferous series. This 

opinion was strengthened, by the fact that he found in the Grand Canon 

10,000 feet of sandstone, shales, and limestones underlying the Tonto 

series uncouformably, and hence separated from them by long periods 

of erosion, and at the base of the latter series he reported finding Silurian fossils. 1

The fossils mentioned by Maj. Powell were studied by Dr. C. A. 

White, who identified the genera Lingulella and Obolella and referred 

them to the Lower Silurian.2

The supposed Primordial age of the Tonto series was accepted by 

Capt. 0. A. Dutton in his account of the physical geology of the Grand 

Canon district.3

The section at the mouth of the Kanab Canon was studied by Mr. C. 

D. Walcott in 1880. Ho found that 450 feet of a mottled limestone and 

100 feet of arenaceous and micaceous shales at the base of the section 

were of Primordial age, as indicated by the presence of the genera Lingulepis, Conocephalites, and Bathyurus in the upper portion, and in addition to these Hyolithes primordialis, Liugulepis, and Crepicephalus in 

the lower beds.4 Further evidence of the Cambrian age of the Tonto 

group was published by Mr. Walcott in 1883. Fossils representing the 

genera Cruziana, Liugulepis, Iphidea, Conocephalites, Crepicephalus, 

and Dikelocephalus were found in the upper 700 feet of the sandstones, 

shales, and limestones that form the upper part of the group in the 

cailoii valleys entering on the left side of the Kaibab plateau.5

PALEONTOLOGY. 

UPPER MISSISSIPPI AREA.

The first reference that we find to the fossils of the Cambrian fauna 

of the Upper Mississippi Valley is by Dr. D. D. Owen in his report of 

184.8 on a geological reconnaissance of the Chippewa land district of

1 Koport on the geology of the eastern portion of the Uinta Mountains and a region of conntry adja. 

cent thereto. Washington, 1870, p. 56.

2 Invertebrate paleontology of the Plateau province, together with notice of a few species from 

localities beyond its limits in Colorado. Kept, on the geology of the eastern portion of the Uinta 

Mountains, by J. W. Powell, Washington, 1876, p. 79.

3 The physical geology of the Grand Canon district. U. S. Geol. Surv., 2d Ann. Eep. 1880-'81. 1882, 

p. 114. 'i

4 The Permian and other Pnloozoic groups of the Kanab Valley, Arizona. Am. Jour.Sci., 3d ser., vol. 20, 

1880, p. 225.

6 Precarboniferous strata in the Grand Cafloii of the Colorado, Arizona. Am. Jour. Soi., 3d ser., vol. 

26,1883, p. 439.
222 THE CAMBEIAN. [BULL. 81.

Wisconsin. 1 The fossils discovered were referred to the genera Asaphus, Agnostus, Triuucleus, and Triarthrus, bat on PI. 7, accompanying 

the report, there is figured, but not named, the head and pygidium of 

Dikelocephalus minnesotensis, and a species of Ptychoparia as now 

known.

In a later paper in 1851 on the paleontology of the lowest sandstones 

of the Northwest he gives the name " Dikello-Cephalou " to a large 

genus of trilobites obtained in the lower sandstone formation.2 He also 

notes the discovery of Lingulas and Orbiculas by himself in 1847 at the 

Falls of St. Oroix, and the discovery of fossils on the Mississippi Eiver 

between the Falls of St. Anthony and the Wisconsin Eiver, the presence of trilobites in the sandstone .10 miles below Mountain Island, etc.

One of the first species described from the u Potsdam" sandstone of 

Wisconsin is Oraptolitlius hallianus Prout, 1851, from the middle portion of the formation at Osceola Mills, near the falls of St. Croix 

Eiver.3

The occurrence of the Potsdam fauna in the sandstone of northeastern Wisconsin is noted by Prof. James Hall in his report to Messrs. 

Foster and Whitney.4 He describes and illustrates Llngula prima Conrad (p. 204), Lingula antiqua Hall (p. 204), and an undetermined species 

of Dikelocephalus (p. 205).

We note that Lingula prima was subsequently described by Hall as 

Obolella polita, and that Lingula antiqua equals Lingulepis acuminata 

of Conrad and the Lingulepis pinnaformis of Owen.

From the material collected from the lower sandstones of Wisconsin 

(the Potsdam sandstone of New York) Dr. Owen described, in 1852, the 

following genera and species: 5

Dikelocephalns (n. geu.), p. 573. Lonchocephalus (n. gen.), p. 575. 

minnesotensis, p. 574. cliippewaensis, p. 576. 

pepinensis, p. 574. hamulus, p. 576. 

miniscaensis, p. 574. Crepicephalus (u. gen.), p. 576. 

ioweusis, p. 575. Menocephalus (n. gen.), p. 577. 

graaulosus, p. 575.

In the description of PI. 1 the species Menocephalus minnesotensis is 

named and figured (Fig. 11) 5 also Crepicephalus ? icisconsensis (Fig. 

13), and on PL la, Crepicephahis ("?) miniscaensis is named and illustrated (Fig. 14). On PI. 1&, the species Lingula pinnaformis is proposed 

and illustrated (Figs. 4, 6, 8) j Lingula ampla is figured and named

1 Report of a geological reconnaissance of the Chippewa land district of Wisconsin ; and incidentally, of a part of Iowa and of the Minnesota Territory. Letter of the Secretary of the Treasury commnnicating a report of a geological reconnaissance of the Chippewa land district of Wisconsin (etc), 

by D. D. Owen. Thirtieth Congress, 1st Sess., Senate Ex. Doc. No. 57, 1848, pp. 13-15.

2 Am. A.SSOC. Proc., vol. 5, 1851, p. 171.

»Description of a new Graptolite found in the Lower Silurian rocks near the falls of the St. Croix

BiTtt* AffliifottIi8ci,,2te,,wL 11,1851,p. 188.

4 Description of new or rare species of fossils from the Paleozoic series. Kept, on the geology of the 

Lake Superior land district, by Foster and Whitney, pt. 2, 1851, pp. 203-231.

5 Geol. Surv. of Wise., Iowa, and Minn., and, incidentally, of a portion of Nebraska Territory. Philadelphia, 1852.
WALCOTT.] PALEONTOLOGY UPPER MISSISSIPPI. 223

(Figs. 5,12), together with figures of Lingula antiqua and L.prima, and 

a number of others placed under Obolus and Orbicula.

Mr. Edward Daniels stated in 1859 that upon a small island in Black 

River he had found perfect impressions of crustaceans consisting of 

double rows of parallel tracks, precisely like those in Montreal. 1 (Protichuites of Logan. 0. D. W.)

In the report of the superintendent of the geological survey of Wisconsin, Prof. Hall describes, from the Potsdam sandstone: 2

Lingula polita, p. 24. Theca primordialis, p. 48. 

Liugula aurora, p. 24. Serpulitea tuurchisonia, p. 48.

In the geological volume he illustrates: 3

Graptolitliu8(Deudrograptu8)hal- Theca primordialis, p. 21.

liamis, p. 21. Serpulites murcliisonii, p. 21. 

Liugula polita, p. 21. Dikelocephalus uuuuesoteusis, p.

piuuaformis, p. 21. 22.

antiqua, p. 21. D. pepiuensis, p. 22.

aurora, p. 21.

In a letter to Principal J. W. Dawson, Prof. Hall describes a new 

crustacean from the Potsdam sandstone under the generic name of 

Aglaspis, stating it to be the same form mentioned in a communication 

to the Albany Institute.4

In 1862 Prof. C. H. Hitchcock published a list of the fossils of the 

Potsdam group in North America, including in it all the species known 

to him described from the Potsdam sandstone and also from the strata 

now referred to the Cambrian of other parts of North America. The 

list includes one hundred and thirty-four species.5

In 18G2 Prof. B. F. Shumard describes from the Potsdam sandstone 

of Wisconsin and Missouri the following species : 6

Dikelocephalus latifrous, p. 101. 

Arionellus bipunctatus, p. 101. 

Coiiocephalites minor, p. 105.

He also noticed under the name of ConocepJialites iowensis, the DiJcelocephalus (?) ioicensis of Owen (p. 102), and Crepicephakis (?) icisconsensis, 

under the name of Gonocephalites icisconsensis (p. 103). The Lonclwceplialus chippewaensis Owen and L. liamulus are both referred to the 

genus Conocephalites (p. 104). A species of Agnostus was referred to 

Agnostus orion (?) of Billings (p. 105).

1 Notes on geology of Wisconsin and adjacent States. Boston Soc. Nat. Hist. Proo., vol. 6, 1859, p. 

310.

2Keport of the superintendent of the geological survey (of Wisconsin), exhibiting the progress of 

the work. January 1, 1861. Madison, 1861, pp. 52.

'Physical geography and general geology. Geol. Surv. Wisconsin, Report, vol. 1, 1862, pp. 1-72.

4 On a new crustacean from the Potsdam sandstone. Canadian Naturalist, vol. 7, 1862, p. 445.

'.Fossils of the Potsdam group in North America. Portland Soc. Nat. Hist. Proo., vol. 1, 1862, pp. 

87-90.

8 Notico of some new and imperfectly known fossils from the Primordial zone (Potsdam sandstone 

and Calciferous Sand-group of Wisconsin and Missouri. St. Louis Acad. Sci. Trans., vol. 2,1862, pp. 

101-105.
224 THE CAMBRIAN. [BULL. 81.

In the same year Prof. Jaincs Hall read before the Albany Institute 

a preliminary notice of the fauna of the Potsdam sandstone, with remarks upon the previously known species and descriptions of some new 

ones from the sandstone of the Upper Mississippi Valley. This was first 

published in the Sixteenth Eeport of the State Cabinet of Natural History in 1863, and in 1867 in the Transactions of the Albany Institute. 

The new genera and species described are as follows: l

Liugnla winona, p. 126.

mosia, p. 126.

aurora var., p. 127. 

Discina(?) iuutilis, p. 130. 

Orthis pepina, p. 134. 

Platyceras primordialis, p. 136. 

Euotnpbalus (?) vaticinns, p. 136. 

Dikelooephalua miunosotensis

var. limbatns, p. 141. 

Dikelocepkalus mmnesotensis

var., p. 141. 

Dikelocephalns spininger, p. 143.

inisa, p. 144.

osceola, p. 146. 

Conocepbalites eos, p. 151.

persons, p. 153.

sbuuiardi, p. 154.

nasutns, p. 155.'

oweni, p. 155.

eryon, p. 157.

anatinus, p. 158.

patersoni, p. 159.

? biuodosus, p. 160.

 winona, p. 161.

diadematus, p. 167. 

Ptycbaspis sp.?, p. 174. 

Cbariocepbalus \vbittieldi,p. 175. 

Illomurus quadratns, p. 176. 

Triartbrella auroralis, p. 177. 

Agnosias josepha, p. 178.

parilis, p. 17-9.

disparilis, p. 179. 

Aglaspis barrandi, p. 181. 

Peiupbigaspis bullata, p. 221. 

Ampbion? inatutina, p. 222. 

Conocepbalites ? (Arionellus ?)

dorsal is, p. 222. 

Conocepbalites optatiis, p. 222.

Of species previously described he redescribed and illustrated:

Graptolitbus ballianus, Prout., as Dendrograptus halliauus, p. 124. 

Lingula arapla, Owen, p. 125.

aurora, Hall, p. 126.

pinuaformis, Owen, as Lingulepis pinnaformis, p. 129. 

Obolus apollinua Owen, as Obolella? polita, p. 133. 

Lingula? polita Hall, as Obolella? polita, p. 133. 

Tbeca primordialis Hall, p. 135.* 

Serpulites inurchisoni, Hall, p. 136.* 2 

Dikelocepbalus minnesotensis, Owen,, p. 138.

pepinensis, Owen, p. 142. 

Couocepbalites minor, Sbumard, p. 149.

minutus, Bradley, p. 150.

Dikelocepbalus iowensis, Owen, as Couocepbalitea iowensis, p. 162. 

Crepicepbalus? wisconsensis, Owen, as Conocepbalites winconsensis, p. 164. 

Loiicbocepbalus bamulus, Oweu, as Conocepbalites bamulus, p. 166. 

Arionellus bipunctatus, Sbumard, p. 169. 

Dikelocephalus miniscaensis, Owen, as Ptychaspis miuiscaensis, p. 171.

granulosns,-Owen, as Ptychaspis granulosa, p. 173.

Agnostus orion (?) Billings, noted by Shumard, is described as Agnostus josepha (p. 178). The genus Dikelocephalus is redefined (p. 137),

1 Preliminary notice of the fauna of tbe Potsdam sandstone, with remarks on the previously known 

species of fossils and descriptions of some new ones from the sandstone of the Upper Mississippi 

Valley. 16th Ann.Kep. Regents Univ. State Cab. Nat, Hist., 1863, pp. 119-220. Albany Inst. Trans., 

vol. 5. 18C7, pp. 93-195. '

2 Pages 135,136 each have an asterisk (') placed after thorn to indicate interpolated pagea.
'WATXJOTT.] PALEONTOLOGY UPPER MISSISSIPPI. 225

and the genus Obolella of Billings is described with special reference 

to the species Obolellapolita (pp. 131-134). 

The new genera described are:

Lingulepis, p. 129. 

Ptychaspis, p. 170. 

Chariocephalus, p. 175. 

Illtenurus, p. 176. 

Triarthrella (subgenus), p. 177. 

Aglaspis, p. 181. 

Pemphigaspis, p. 221.

The geims Conaspis is proposed in the event of a new generic group 

being formed of Conocephalites persons, C. shumardi, C. nasutus, C. 

otveni, C. eryon, C. anatinus, and C.patersoni (p. 152).

Prof. Hall states that he was unable to recognize the six successive 

trilobite beds of the sandstone as indicated by Dr. Owen, but he 

nevertheless refers the species described to three different epochs of 

the Potsdam period, as follows:

In the lower beds of the formation I have found Conocephalites proper, together 

with Liugnla, Lingulepis, Obolella ? and Theca. In the middle stage, neither tho 

limits of tho beds, nor the range of species or genera, have been so well determined; 

but, grouping together all that I have found between the well-defined upper beda 

and the lowerfossilferous beds known, we have Conocephalites, Dikelocephalus, Ariouellus, Ptychaspis, Chariocephalus, Illoenurus and Aguostus, in the trilobitic fauna, 

together with Orthis and Platyceras.

The Graptolitidao apparently begin their existence somewhere in this central epoch, 

but their precise relations to the other beds have not been determined.

In the higher beds of the formation, and clearly separated from the great central 

mass, we have the genera Dikelocephalus, Triarthrella, and Aglaspis, together with 

Lingula, Serpulites, and Euomphalus.

We observe, therefore, that the earliest trilobites are referable to the genus Conocephalites ; and the genus Dikelocephalua does not appear in the first stages of tho 

formation, nor below the beds which I have referred to the second or middle stage of 

the period. There this genus appears in three species, smaller and less conspicuous 

than those in the higher beds. It is only in the later stages of the sandstone that 

the typical species of this genus of Dr. Owen appear, and those from the lower beds, 

thus referred by him, belong apparently to other genera. 1

From a small collection of fossils from the Potsdam sandstone of 

Sauk County, Wisconsin, Dr. Alexander Winchell describes in 18G4 

four new species and mentions the presence of some others that have 

been described.2 The new species are:

Orthis barabuensis, p. 228. 

. Straparollus (Ophileta) primordialis, p. 228. 

Pleurotornaria ? advena, p. 228. 

Ptychaspis barabuensis, p. 230.

He mentions the occurrence of ScolitJius linearis (p. 227) and JHJceloceplialus minnesotensis and Dilcelocephalus pepinensis (p. 229). From' 

the Lake Superior sandstone he describes Palceophycus articulatus (p. 

231) and P. informis (p. 232). The two latter species are doubtfully re-

'Op. cit.,p. "183.

'Notice of a small collection of fossils from the Potsdam Sandstone of Wisconsin and Lake Superior 

Sandstone of Michigan. Am. Jour. Sci., 2d sor., vol. 37,1804, pp. 226-232.

Bull. 81 15
226 THE CAMBRIAN. [BULL. 81.

ferred to the Cambrian fauna. In this paper, Dr. Winchell points out, 

or, rather, he claims, that Dikelocephalus and Ptychaspis occur at 

the recognized base of the Potsdam sandstone.1

The preliminary notice of the fauna of the Potsdam sandstone of 

the upper Mississippi Valley read before the Albany Institute in 1862, 

by Prof. J. Hall, was published with illustrations in 1863, as has been 

noticed. The original paper appeared in 1867 in the transactions of 

the Albany Institute. The descriptions are the same as those of the 

paper of 1863, with the exception of the omission of those of Theca 

primordialis and Serpulites murchisoni.

From the material collected by the Wisconsin Geological Survey Prof. 

R. P. Whitfield described in 1878 under the title of Potsdam sandstone 

species :2

Palseophycus plumosus, p. 50. Ptychaspis striatus, p. 55.

Triplesia primordialis, p. 51. minuta, p. 55.

Palseacmsea irvingi, p. 51. Agraulos (Bathyurus?) woosteri,

Bellerophon antiquatus, p. 52. p. 56.

Conocephalites calymenoides, p. Arionellus (Agraulos) convexus,

52. p. 57.

Crepicephalus onustus, p. 53. Ellipsocephalus curta, p. 58.

Dikelocephalus granulosus, Owen, is redefined under Ptychaspis granulosa, but not the Ptychaspis granulosa of Hall (p. 54). Ptychaspis granulosa, Hall, is redescribed as P. striala (p. 55).

In 1879 Prof. T. 0. Ohamberlin referred to some tracks found on the 

Potsdam sandstone by Bev. A. A. Young, of New Lisbon, Wisconsin. 

He named Climactichnites youngi and G. fosteri. The material was subsequently studied by Mr. J. E. Todd, who published an illustration and 

description of the species. These tracks or trails are congeneric with 

Climaotichnites wilsoni, described by Logan in 1863, from Perth, Canada.3

In 1882 in his final report on the paleontology of Wisconsin, Prof. 

E. P. Whitfield described from the Potsdam sandstone the following 

new species: 4

Holopea sweeti, p. 174. Dikelocephalus lodensis, p, 188. 

Conocephalites ? quadratus, p. Aglaspis eatoni, p. 192.

180. Arenicolites woodi, p. 177. 

(Ptychaspis ?) explanatus, p.

181.

He also describes and illustrates:

Paleophycus plumosus Whitf., p. 169. 

Lingulepis pinnaformis, Owen, p. 169. 

Orthis pepina, Hall, p. 170.

barabuensis, Winchell, as Leptsena barabuensis, p. 171. 

Triplesia primordialis Whitt., p. 172.

1 Op.oit.,p.22G.

2 Preliminary descriptions of new species of fossils from the lower geological forraatiops of Wiscon-_ 

sin.. Geol. Surv. of Wisconsin, Ann. Eep. for 1877,1878, pp. 50-58.

3 A description of some fossil tracks from the Potsdam sandstone. Wisconsin Acad. Sci., Trans., 

vol. 5, 1882, pp. 276-281. 

'Paleontology (of Wisconsin). Geology of Wisconsin, vol. 4,1882, pp, 169-193.
WALCOTT.J PALEONTOLOGY UPPER MISSISSIPPI. 227

Palajacmtea irvingi, p. 173.

Straparollus (Ophileta) primordialis, Winchell, as Ophilefca (Raphistoma) primordialis, p. 173.

Theca primordialis, Hall, as Hyolithes primordialis, p. 175. 

Bellerophon autiquatus, Whitf., p. 176. 

Conocephalites calyinenoides, Whitf., p. 179. 

Crepicephalns onustas, Whitf., p. 182.

Conocephalites gibbsi, Whitf., as Crepicephalus? gibbsi, p. 184. 

Dikelocepbalusgrannlosus, Owen, as Ptychaspis grauulosa, p. 185. 

Pfcycbaspis grauulosa, Hall, as P. striata, p. 186.

iniuuta, Whitf., p. 186. 

Dikelocepbalns minnesotensis Owen, p. 187. 

Agraulos (Bathyurus?) woosteri, Whitf., p. 189. 

Arionellus (Agraalos) convexus, Whitf., as Ariouellns couvexus,

Whitf., p. 190. 

Ellipsocepbalus curfcus, Whitf., p. 191.

In the preliminary remarks on the fauna he says:

It is a matter of considerable interest that, in different localities of the Potsdam 

formation, the forms of trilobites found are generally specifically distinct; and notwithstanding the large number of species already described from this formation, both 

in this State and other parts of the country, other new forms, readily detected by 

those familiar with the several details of structure peculiar to these animals, are met 

with at almost every new locality examined. This change in species between different localities is usually accompanied also b y some slight difference in the material 

or composition of the rock, which not only shows that the species were of short duration in time, or that they were restricted to limited geographical areas, but that a 

change in the conditions of life and circumstances under which the animals existed, 

and with which they had to contend, was constantly taking place. How much these 

circumstances or conditions had to do with the production of forms, or modification 

of types among them, it would be difficult to determine; but one thing is certain, 

that where the same character of rock and apparent conditions of deposition prevail 

over a limited geographical area, or are repeated within a slight vertical range, we 

are pretty sure to find the same, or closely allied forms represented, showing that 

under like conditions similar forms prevail. 1

In 1883, when describing the life of the Potsdam epoch, in the General Geology of Wisconsin, Prof. T. C. Charnberliii illustrates the following species: 2

Palfeophycus plurnosus, p. 125, Fig. 11'. 

Bollerophon antiquatus, Whitfield, p. 126, Fig. 12, a, b. 

Ophileta priraordialis, Wincholl, p. 126, Fig. 12, c, d. 

Holopea sweeti, Whitfield, p. 126, Fig. 12, o. ° , 

Palfcacmsoa irvingi, Whitfield, p. 126, Fig. 12, f. 

Platyceras primordialis, Hall, p. 126, Fig. 12, g. 

Serpulites murchisoui, Hall, p. 126, Fig. 12, h. 

Theca primordialis, Hall, p. 126, Fig. 12, i. 

Dendrograptus halliauus, Front, p. 126, Fig. 12, j. 

Lingula antiqua, Conrad, p. 127, Fig. 13, b. 

Lingulella stoneana, Whitfield, p. 127, Fig. 13, a.

aurora, Hall, p. 127, Fig. 13, c.

ampla, Hall, p. 127, Fig. 13, d.

mosia, Hall, p. 127, Fig. 13, e.

'Op. cit., pp. 163.164.

* General Geology. Historical Geology. Paleozoic Era. Geol. Wis. Survey of 1873-1879, vol. 1,1883.
228 THE CAMBRIAN. [BULL.81.

Lingulepis pinuaformis, Owen, p. 127, Fig. 13, f, g. 

Obolella polita, Hall, p. 127, Fig. 13, h. 

Orthis pepina, Hall, p. 127, Fig. 13, i,j, k, 1. 

Triplesia primordialis, Whitfield, p. 127, Fig. 13, in. 

Leptsena barabuensis, Wincbell, p. 127, Fig. 13, n, o. 

Arenicolites woodi, Whitfield, p. 128, Fig. 14, a, b. 

Dikelocephalus sp. ?, p. 129, Fig. 15.

lodensis, Whitfield, p. 130, Fig. 16, a, b.

pepiiiensis, Hall, p. 130, Fig. 16, c, d, e, f. 

Aglaspis eatoni, Whitfield, p. 130, Fig. 16, g. 

Chariocephalus whitfieldi, Hall, p. 130, Fig. 16, h. 

Arionellus ccmvexus, Whitfield, p. 130, Fig. 16, i. 

Ptychaspis minuta, Whitfield, p. 130, Fig. 16, j, k. 

Illaenurus quadratus, Hall, p. 130, Fig. 16,1, m, n, o, p. 

Crepicephalus gibbsi, Whitfield, p. 130, Fig. 16, q. 

Conocephalites wisconsensis, Owen, p. 131, Fig. 17, a, b, c.

calymenoides, Whitfield, p-. 131, Fig. 17, d. 

Agnostus josepha, Hall, p. 131, Fig. 17, e, f. 

Ellipsocephalus curtus, Whitfield, p. 131, Fig. 17, g. 

Agraulos woosteri, Whitfield, p. 131, Fig. 17, h, i. 

Pernphigaspis bullata Hall, p. 131, Fig. 17, j. 

Cliniactichnites youngi, Chamberlin^ p. 132, Fig. 18.

fosteri Chamberlin, p. 132, Fig. 18.

The species Orthis remnichia and 0. sandbergi are described in 1886 

by Prof. K. H. Winchell from the St. Croix sandstone. 1

In 1890, Mr. 0. D. Walcott described the following species from the 

Upper Cambrian of Wisconsin and Minnesota: 2

Metoptoma? rniuneiskensis.p. 267.

? peracuta, p. 267. 

Conularia cambria, p. 270. 

Spirodeutaliuni, n. gen., p. 271. 

Spirodentaliura osceola, p. 271. 

Ptychoparia connata, p. 272.

pero, p. 274. 

Agraulos? thea, p. 277.

RED SANDSTONE OF LAKE SUPEKIOR.

On PI. i C and n, Figs. 1 and 2.of the illustrations in the Geological 

Eeport of Wisconsin, Iowa, and Minnesota, 1852, Dr. D. D. Owen figures certain markings he observed on sandstones from the northwest 

shore of Lake Superior. He considered they probably indicated the 

remains of fossil sea-weeds or'fncoids.

There is a specimen in the collections of the National Museum, labeled " Plants of Lake Superior, D. D. Owen." The specimen looks 

very much like the sandstones of the interior of Wisconsin, and is covered with casts of annelid trails, more or less crushed and matted down, 

which gives a resemblance to fucoids. Of traces of life other than that 

of annelid trails and borings nothing has to my knowledge been made 

known to the scientific world.

1 New species of fossils. 14th Ann. Eep. Minn. Geol. Nat. Hist. Surv., 1886, pp. 317-318.

* Description of new forms of Upper Cambrian fossils. U. S. Nat. Mns. Proc., vol. 13,1890, pp. 267-279.
WAI.OOTT.] PALEONTOLOGY ADIRONDACK. 229

MISSOURI.

The ouly description of a fossil referred to the Cambrian of Missouri 

is that of Lingulella lamborni by Meek.1

EASTERN BORDER OR ADIRONDACK SUB-PROVINCE.

The first notice of anything of an organic nature in the strata now 

referred to the Potsdam or Upper Cambrian zone, about the Adirondacks, was by Mr. J. H. Steele in 1825, who described certain large calcareous concretions.2 These were subsequently described in detail by 

Prof. J. Hall and named Cryptozoon proliferum?

The second notice is by Dr. E. Emmons, who states that near Jleeseville, in the bottom of the fissure at the high bridge, he found numerous 

specimens of small bivalve inollusca, a lingula.4

Llngula aciiminata was described by Mr. T. A. Conrad as occurring 

in the Calciferous sandrock, and in the table of classification he places 

it as occurring in the gray Calcareous sandstone at the base of the 

Lower Silurian above the Cambrian system.5 It is now known to occur 

in abundance in association with Dikelocephalus and Upper Cambrian 

fossils in a calcareous sandrock and limestone, both at Whitehall and 

in Saratoga County, and in the Potsdam sandstone on Marble Eiver, 

Franklin County, New York.

In his description of the Potsdam sandstone at Au Sable Chasm, Jefferson County, New York, Dr. Emmons figures and names Lingula 

antiqua.6 The same woodcut is used by Prof. Hall to illustrate Lingula 

aciiminata of Conrad.7

In volume I of the Paleontology of New York, Prof. J. Hall defines 

the genus Scolithus of Haldemau (p. 2), and describes S. linearis 

Haldeman (p. 2); Lingula prima of Conrad is described and illustrated; 

and Lingula antiqua is proposed as a new species for the specimen figured by Emmons as Lingula antiqua (p. 3). These species are illustrated 

on Plate i.8

Attention was called to the presence of a track and footprint of an 

animal in the Potsdam sandstone of Lower Canada by Sir W. E. Logan

1 Notice of a new brachiopod from the lead-bearing rocks at Mine la Motte, Missouri. Phila. Acad. 

Nat. Sci., Proc., vol. 23,1871, p. 185.

2 A description of the Oolitic formation lately discovered in the county of Saratoga, and State of New 

York. Am. Jour. Sci., vol. 9, 1825, pp. 16-19.

3 Crypto7,oon,n. gen., Cryptozoon proliferum, n. sp. Description of PI. VI. 30th ADD. Rep. State 

Mns. Nat. Hist., 1884.

4 'Report of the geologist of the 2d geological district of New York. Second annual report of the 

Geological Survey of N. Y. Albany, 1838, p. 230.

6 Second annual report of the paleontological department of the survey, Third annual report of 

the Geological Survey of New York. Albany, 1830, pp. 63, C4.

"Geology of New York, Part 2, comprising the survey of the 2d geological (northern) district. 

1842, p. 2C8, fig. 68.

"Geological survey of New York; its influence on the productive pursuits of the community. N. 

Y. State Agric. Soc. Xrans., for 1843, ]8W, p. 252.

8 Paleontology of New York, vol. J, containing descriptions of the organic remains of the lower 

division of the New York System. Albany, 1817.
230 THE CAMBRIAN. [uuLL.8l.

in 1851. He described its mode of occurrence and stratigraphic position.1 This paper was followed by one by Prof. Owen, who refers the 

tracks to a species of tortoise.2

At a meeting of the British Association for the Advancement of 

'Science, held at Ipswich in 1851, Sir W. E. Logan exhibited a slab of 

sandstone and a cast from a larger one, showing what Prof. Owen had, 

in a communication to the Geological Society, pronounced to be'a track 

and footsteps of a species of tortoise, thus proving the existence of 

reptiles at the very earliest period of known animal life.3

In describing in 1852 the sandstone occurring in Beauharnois County, 

Canada, Sir W. E. Logan makes the following observation upon Sco~ 

litltus linear is :4

In this part it [the sandstone] is abundantly marked over considerable surfaces by 

what the geologists of New York have called Scolitkus linearis, which consists, where 

the rock is weathered, of straight, vertical cylindrical holes, of about an eighth of an 

inch in diameter, descending several inches, and where the rock is unweathered of 

corresponding solid cylinders, composed apparently of grains of sand, cemented by 

a slightly calcareous matrix, more or less tinged with peroxide of iron. Mr. Hall 

and other American geologists include them among the Fucoids of the rock, but they 

appear to me more like worm holes. In one or two instances I have perceived that 

the tubes are interrupted in their upward course by a thin layer of sand, of a portion which descends into them and stops them up; and from this it Avould appear 

that the cylinders were hollow when the superincumbent sand was spread over them. 

Whatever may be the origin of the tubes, they strongly mark many beds in the upper 

part of the sandstone throughout the Canadian portions of its distribution already 

mentioned; and it is stated by Mr. Hall that the same characteristic accompanies 

the Potsdam sandstone in New York and Pennsylvania and as far as Tennessee.

He also speaks of the presence of Fucoides and of Lingula antiqua. 

This is followed by a detailed account of the strata containing the footprints described in the same volume by Prof. Owen.

This paper by Mr. Logaii was followed by one by Prof. Owen, who 

described the various footprints and impressions under the following 

names :5

Protichnites septem-notatns, p. 214. 

Protichuites octo-notatns. p. 217.

latus, p. 218.

multinotatus. p. 219.

lineatus, p. 220.

altemans, p. 221.

The descriptions are accompanied by admirable illustrations of the 

varieties designated. He concludes that the impressions appear to have 

been made by animals allied to Liinulus.6

1 On the occurrence of a track and footprints of an animal in the Potsdam sandstone of Lower 

Canada. Quart. Jour. Geol. Soc., London, vol. 7,1851, pp. 247-250.

2 Ibid., p. 250-252.

3 On the age of the copper-bearing rocks of Lake Superior and Huron, etc. British Assoc, Hep. 

Trans., of sections for 1851-'52, p. 62.

4 On the footprints occurring in the Potsdam sandstone of Canada. Quart. Jour. Geol. Soc. Lond., 

Proc., vol. 8, 1852, pp. 200, 201.

8 Description of the impressions and footprints of the Protichnites from the Potsdam sandstone of 

Canada. Quart. Jour. Geol. Soc. London, vol. 8, 1852, pp. 214-225.

6 Op. cit, p. 224.
PALEONTOLOGY ADIRONDACK. 231

In 1856 Dr. Emmons published a description of Lingula prima Emmoiis, Lingula antiquata Emmons, and L. acuminata Conrad. The two 

latter species are illustrated on PI. iv, but in the description of the 

plate the figure of Lingula antiquata is called L. prima by error.1

In 1860, Prof. F. H. Bradley described and illustrated Conocephalites 

minutus from the Potsdam sandstone at Au Sable Chasm, near Keeseville, New York.2

The announcement of the discovery of another type of track in the 

Potsdam sandstone was made by Sir W. E. Logan, in 1860. For this 

he proposed the name Climacticlmites wilsoni.*

In 1869 Prof. O. C. Marsh described a new species of Protichnitea 

from the Potsdam sandstone of Essex County, New York, naming it 

Protichnites logananus,*

As the result of comparative study of different tracks, Dr. J. W, 

Dawson concluded that Protichnites of Owen was possibly made by 

some Limuloid crustacean.3

From collections made at Keeseville, New York, Messrs. Hall and 

Whitfield described the genus Pakeacinrea, the type species, being 

Palceacmma typica and Hyolithes gibbosa.6

In 1877 Mr. E. J. Chapman says that the fossil tracks known as Protichnites and Climactichnites are of such a nature that he does not consider them to be of animal origin; and he suggests that they are nothing more than impressions of large fucoids. If this idea be accepted 

he proposes to change the names to Protichnides and Climactichnides.7

From the limestone in Saratoga County, New York, in which Mr. J. 

H. Steele noticed the large concentric concretions, Mr. C. D. Walcott 

described in 1879 the following species: 8

Ptatyceras miiiutissimum, p. 129. 

Metoptonia cornutiforrne, p. 129. 

Conocepbalites calciferus, p. 129. 

Conocephalites harttii, p. 130. 

Ptychaspis speciosue, p. 131. i

The presence of a species closely allied to Bathyurus armatus of Billings was noticed; also Stromatopora sp.?, Lingula acuminata, Metop1 American Geology, containing a full statement of the principles of the science, with full ilustrations of the characteristic American fossils. Albany, 1856, vol. 1, pt. 2, pp. 202, 203.

8 Description of a new trilobite from the Potsdam sandstone. Am. Jour. Sci., 2d aer., vol. 30, I860, 

P- 241.

8 On the track of an animal lately found in the Potsdam formation. Canadian Nat., vol. 5,1860, pp. 

282-285.

4 Description of a new species of Protichnites from the Potsdam sandstone of New York. Am. Jour. 

Sci., 2d ser., Vol. 48,1869, pp. 46-49.

0 Impressions and footprints of aquatic animals and imitative markings on Carboniferous rocks. 

Am. .Tour. Sci., 3d ser., vol. 5,1873, p. 17.

fl Notice of two new species of fossil shells from the Potsdam sandstone of Now York. 23d Hep. 

Now York State Mus. Nat. Hist., 1873, p. 242.

7 On the probable nature of the supposed fossil tracks known as Protichnites and Climactichnites. 

Canadian Jour. Sci., Lit. and Hist., new series, vol. 15,1877, p. 490.

8 Descriptions of new species of fossils from the Calciferous formation. 32d Kepi N. Y. State Mus. 

Nat. Hist., 1879, pp, 129-131.
232 THE CAMBRIAN. [BULL. 81.

toma simplex, Murchisonia sp. ?, and a Lamellibranchiate shell. The 

fauna was correlated with that of the Potsdam sandstone of Iowa and 

Wisconsin, although the rocks were referred to the Calciferous formation. This reference was corrected in 1884. 1

In 1883, Mr. W. F. Ferrier called attention to the presence of tracks 

on the Potsdam'sandstone at the head of An Sable Chasm, in Essex 

County, New York. They were referred to the genus Gyrichnites of 

Whiteaves.2 Later the tracks discovered by Mr. Ferrier were made the 

subject of a note by Sir J. W. Dawson, who proposed the generic name 

of Clydichnites for them.3

In a note on some obscure organisms in the roofing slates of Washington County, New York, Prof. James Hall redescribes ButhotrepMs f 

asieroides Fitch as Dactyloidites bulbosus.*

A revision of the fauna occurring in the limestone beds of Saratoga 

County was made by Mr. C. D. Walcott in 18863 and the following list 

was published: 5

NEW 1TOHK. WISCONSIN.

Oyptozoa proliferum.........................................

Lingulepis acuminata..............Lingulepis pinmeformis.

Platyceras miuntissimum........ ..Platyceras minutiasimuui.

Platyceras lioyti..............................................

Metoptoma cornutitbrme......... ..Metoptoma cornntiforme.

simplex..................................................

Billiugsia saratogensis........................................

Matthevia variabilis..........................................

Dicellocephalus kartti.......... ....Dikelocephalus pepiuensis.

speciosus .........................lodensis.

Ptyclioparia calcifera..............Ptyclioparia wiscouseusis.

(A.) saratogensis ..................oweni (of Hall).

As the result of the comparison of an extended scries of specimens 

from the Potsdam sandstone of Buckingham, Quebec, Messrs. Ami and 

Sowter concluded that Scolitlms linearis and 8. canadensis were identical species j the main differences existing between the two being 

principally in the preservation, 8. canadensis occurring in hollow tubes 

or burrows, while 8. linearis occurs as casts of the interiors of burrows 

or holes.6

In 1890 Mr. C. D. Walcott described7 the following species from the 

limestone in the vicinity of Saratoga Springs, New York:

Platyceras lioyti, p. 268. 

Trochus ? saratogensis, p. 268. 

Agraulos saratogensis, p. 276.

1 Potsdam fauna at Saratoga, New York. Science, vol. 3,1884, pp. 136,137.

a Notes on a fossil track from the Potsdam sandstone of northern New York State. Canadian Nat. 

new ser., vol. 10,1883, pp. 466, 467.

3 Impressions on Potsdam sandstone. Science, vol. 1,1883, p. 177.

4 Note on some obscure organisms in the roofing slates of Washington Comity, New York. 39th 

Rep. N. Y. State Mus.Nat. Hist., 1886, p. 160, pi. 11, fig. 1,2.

6 Second contribution to the studies of the Cambrian faunas of North America. U. S. Geol. Survey, 

Bull. No. 30,1886, p. 21.

a lteport of the geological branch [of Ottawa Field Naturalists' Club]. Ottawa Naturalist, vol. 1, 

1887, pp. 96, 97.

7 Description of new forms of Upper Cambrian fossils. U. S. Nat. Mus., Proc., vol. 13,1890, pp. 270-279.
WAICOTT.] PALEONTOLOGY DAKOTA. 233 

WESTERN BORDER OR ROCKY MOUNTAIN SUBPROVINCE.

In a letter from Messrs. Meek and Hay den to Lieut. G. K. Warren, 

dated February 8,1858, attention is called to the identification of fossils from a sandstone in the Black Hills equivalent to the Potsdam sandstone of the New York series. They recognized Lingula, Obolus?, and 

fragments of trilobites, belonging to species known to occur in the 

Potsdam formation in Wisconsin and Minnesota.1 This notice was followed in 1861 by the publication of the first description of the Cambrian 

fauna of the Eocky Mountains. The new species described but not 

illustrated include Obolella nana, Theca (Pugiunculus) gregaria, and 

Arionellus (Crepicephalus) oiceni.2 The descriptions of the species were 

republished in 1862, in the American Journal of Science, in connection 

with figures illustrating them. The last species is described as Arionellus 9 oweni. There were also identified from the same horizon Lingula 

prima Conrad and Lingula antigua Hall.3

The Black Hills fauna was again described by Messrs. Meek and 

Hayden in 1864, in their account of the paleontology of the Upper Missouri. Lingula antiqua, mentioned in their letter of 1858, is identified as 

Ungulepis pinnaformis Owen (p. 2), and the name L. dalcotensis proposed 

in the event of the shell being subsequently determined to be a new 

species (p. 3). A description and illustration is also given of Lingulepis 

prima Conrad (p. 3), Obolella nana, M. & H. (p. 4), Theca gregaria, M. 

& H. (p. 5), Agraulos oweni, M. & H. (p. 9), (Arionellus (Crepicephalus) 

oiveni, of the paper of 1861), and an undetermined species of Agraulos 

(p. 10). All of the species are referred to the Potsdam or Primordial 

sandstone.4

In 1876, when reporting upon the fossils collected by Captain Ludlow's expedition to the Yellowstone National Park, Prof. E. P. Whitfield described two species that are now referred to the Upper Cambrian 

zone, Crepicephalus (Loganellus) montanensis and Arionellus tripunc- 

 talus, referring them to the limestone of the Potsdam group overlying 

the quartzite near Camp Baker.6

A preliminary report on the paleontology of the Black Hills by Prof. 

E. P. Whitfield contains a description of Pakeochorda prima, Pakcophycus occidentalis, Lingulepis cuneolus, L.perattenuatus Crepicephalus (Loganellus) centralis, and C. (L.) planus. All of these species are referred

1 Fossils of Nebraoka. Letter from F. B. Meek an:l F. V. Hayden. A.in. Jour. Sci., 2cl ser., vol. 25, 

1858, p. 439.

"Descriptions of new Lower Silurian (Primordial), Jurassic, Cretaceous, and Tertiary fossils, collected in Nebraska, with some remarks on the rocks from which they were obtained. Phil. Acad. Sci., 

Proc., vol. 13,1861, pp. 435,436.

3 The Primordial Sandstone of the Eocky Mountains in the Northwestern Territories of the United 

States. Am. Jour. Sci., 2d ser., vol. 33,1862, pp. 73,74.

4 Paleontology of the Upper Missouri; a report upon collections made principally by the expeditions 

under command of Liout. G.K. Warren in 1855-'56. Invertebrates. Smithaonian Contributions No. 

172,1884, pp. 1-10.

0 Descriptions of new species of fossils. Report of a reconnaissance from Carroll, Montana Terr., 

on the Upper Missouri, to the Yellowstoue Park and return, made in the summer of 1875 by Win. 

Ludlow, 1876, p. 141.
234 . THE CAMBRIA^. [BULL. si.

to the Potsdam formation of the Black Hills of Dakota. 1 In the final report, which appeared in 1880, the species described in the preliminary 

report are illustrated, and descriptions and illustrations given ofPalceopliycus sp. undet., Arenocolites sp. undet. (p. 333), Lingulepi$ pinnaformis (p. 331), Lingulepis dakotentis (p. 337), Obolus ? pectenoides (p. 

338), Obolellapolita (p. 339), Obolella nana (p. 340). In the preliminary 

remarks to the paper it is stated that the horizon of the Potsdam formation of the Black Hills appears to be, so far as the fossils will serve to 

determine, about the same as that of Wisconsin and the neighboring 

States.2

The only fossils of the Cambrian fauna identified in Colorado are a 

species of Dikelocephalus from Quandary Peak of the Mosquito Range,3 

and the Lingulepis found in the Trout Creek section (p. 62).

In 1890 Mr. C. D. Walcott 4 described three species from the Upper 

Cambrian of the Black Hills of Dakota. They were Hyolithes newtoni 

(p. 270), Ptycliopariavacuna (p. 275), and P. (Liostracus) panope (p. 275).

TEXAS.

The first notice of the presence of a fauna in Texas subsequently 

assigned to the Cambrian is by Dr. Eoemer in 1849. A description of 

Lingula acutangula (p. 420) and Pterocephalia sancti-sdbce (p. 421) is given 

by him in that year without illustrations.5

In his more extended work on the geology of central Texas he describes and illustrates Lingula acutangula (p. 90), Pterocephalia sancti- 

'sabce (pp. 92, 93), and the genus Pteroceplialia (p. 93). He also illustrates the head of a trilobite, allied to Arionellus, and the pygidiuni of 

another species, on Table xi.6

The primordial character of the fauna referred to the Silurian by Dr. 

Eoemer was announced by M. J. Barrande the following year. He 

compared it with the fauna of the Potsdam sandstone of New York and 

Wisconsin.7

As geologist of the State of Texas, Dr. B. F. Shumard described in 

1861, the strata referred to the Potsdam sandstone. Of the fossils collected he describes as new;

Agnostns coloradoensis, p. 218. 

Ariouellus (Bathyurus) texanus, p. 218. 

planus, p. 219.

1 Preliminary report on the Paleontology of the Black Hills. U. S. Geol. and Geog. Surv. of the Rocky 

Mountain region, 1877, pp. 7-11.

2 Paleontology of the Black Hills of Dakota. Report on the geology and resources of thw Black Hills 

of Dakota, 1880, pp. 329-344.

3 Geology and Mining Industry of Leadville, Colorado. TJ. S. Geol. Surv., Monograph vol. 12, pt. 1, 

1886, p. 60.

4 Description of new forms of Upper Cambrian fossils. TJ. S. Nat. Mus. Proc., vol, 13,1890, pp. 267- 

279.

6 Texas. Mit besonderer Eiicksicht auf deutsche Auswanderung und die physischen Verhaltnisse 

ties Landes nach eigener Beobachtung geschildert. Bonn, 1849, pp. 420-421.

6 Die Kreidebilduugen von Texas und ihre organischen Eir.sehlusse. Bonn, 1852.

7 (Silur-Gebilde in Texas und am Obereu See.) Keues Jahrbuch fur Miner, 1853, pp.440,447.
WAUDOTT.I PALEONTOLOGY TEXAS AND ARIZONA. 235

Conocephalites depressus, p. 219.

billingsi, p. 220. 

Dikelocephalus roemeri, p. 220. 

Disciua rnicroscopica, p. 221.

and he mentions Camerella sp. ?, and Oapulus sp. ? (p. 221).1 He correlates this fauna with that provisionally designated as " being v.ery 

analogous to the Potsdam of Iowa, Wisconsin, and Minnesota," 2 and 

refers it to the Potsdam sandstone.

In the collections obtained by Mr. C. D. Walcott in his reconnaissance of the central area of Texas the following species have been 

identified:

Eocystites sp. ? Ptychoparia occidens, Walcott.

Lingnla acuuiinata, Conrad. affiuis, Walcott.

perattenuata, Whitf. bnrnetensis, Walcott.

Obolella polita, Hall. llauoensis, Walcott.

Triplosia primordialis, Whitf. ? nietra, Walcott.

Ortliis coloradoensis, Shuniard. pero, Walcott.

remnichia, Wiuchell. ? urauia, Walcott.

Platyceras texanuin, Walcott. siniilis, Walcott.

Udlorophou antiquatns, Whitf. patersoni, Hall.

Dikclocephalus ininnesotensis, perseus var., Hall.

Owen (?). wisconseusis, Owen.

lielli, Billings. Agraulos convexus, Whitf.

Pfcychaspis grauulosa, Owen. Agranlos ? sp. ? 

Chariocephalustninifrons, H. &W. Illtcnurus dia, Walcott.

This fauna will be illustrated in connection with a review of the Upper Cambrian fauna of North America now in course of preparation.

In 1890 Mr. Walcott 3 described the following new species from Upper Cambrian strata of Burnet and Llano Counties:

Platycoras texauuin, p. 2G8. 

Ptychoparia burnetensis, p. 272. '

llauoensis, p. 272.

? nietra, p. 273.

pero, p. 274.

? urauia, p. 274. 

Illajnurus ? dia., p. 277.

ARIZONA.

The paleoutologic work on the Cambrian fauna found in Arizona has, 

thus far, been confined to the identification of the species discovered 

in the Touto formation of the Grand Canon. A preliminary study of 

the fauna has been made and drawings prepared of the species, but up 

to the present time nothing has been published in relation to them.

1 The Primordial zone of Texas, with descriptions of new fossils. Am. Jour. Sci. 2d ser., vol.32, 

1801, pp. 213-221.

2 Op. cit., pp. 217, 218.

8 Description of new forms of Upper Cambrian fossils. U. S. Nat. Mus. Proc., vol. 13,1890, pp. 207-279.
CHAPTEEIII.

NOMENCLATURE EMPLOYED IN THE DESCRIPTION OF THE FORMATIONS.

Several considerations are to be borne in mind relative to geologic 

nomenclature:

(a) The name in itself is nothing unless it conveys to the mind a 

clear impression of what it refers to and enables the student to make a 

correlation between its entity and some other entity that has another 

terminology.

(6) Priority of discovery and naming should be sustained by the proof 

of the accuracy of the original observations, the latter to be judged by 

the testimony of the formations in the areas where they were first made. 

If the original proposer of a name bases it upon such errors of observation and interpretation that subsequent observers can not verify his 

work, and the name can be used only by dropping a name proposed as 

the result of accurate observation and definition, the latter should be 

retained and the law of priority should not be used to bolster up an indefinite term.

(c) Long use of, and the general acceptance of, a well defined term by 

the scientific world gives that term a standing that even the claims of a 

half understood, badly defined term supported by priority should not 

displace. This may be called the law of usage.

(d) From the faqt that all the strata of the geologic series do not exist in any one geologic province and that unconformities between different portions of them are not contemporaneous in all provinces, it necessarily follows that the rock series of any one geologic province can not 

possibly be the chronological equivalent of the rock series of other 

provinces. Overlappings of series of different chronologic age must 

occur, and it is therefore impossible for any one geologic province to 

afford a nomenclature that is applicable to the geologic provinces of 

the entire world or to the entire geologic series.

(e) Each geologic province should have a nomenclature denoting by 

name each formation contained in it and, if necessary, the names to be 

applied to the groupings of the formations; but, if practicable, the 

formations and the grouping of formations should be referred to some 

position within the larger composite groups. For instance, the Potsdam standstone of New York, the Saratoga County limestone, and the 

Dutchess County limestone are lithologically distinct formations, but 

they are grouped under the Upper Cambrian terraue as a portion of 

the Cambrian group. 

236
WALCOTT.] NOMENCLATURE CAMBRIAN. 237

This method necessitates the multiplication of uames,but if it insures 

accuracy of statement and meaning it is much better than the use of a 

few old names that have been established in some one geologic province 

and extended over other upper Cambrian formations in other geologic 

provinces that can not be proved to be identical or synchronous.

(/) The study of the serial relations among rocks by the modern 

method is of as much importance as that of the specific relations of distipct horizons or of particular formations. The serial relations of one 

seriesof rocks in one province can be compared with the serial relations of 

another group in another province 5 but the two should receive separate 

names and be grouped under the greater series to which they belong. 

For instance, the Trenton series of New York may be compared with 

the Lebanon series of Tennessee and united as a portion of the Lower 

Silurian (Ordovician) and respectively compared with the same portion 

of the Lower Silurian (Ordovician).

(g) If it is found that the strata included in a named formation, terrane, or group embraces portions of other formations, terranes, or groups 

it is allowable to remove portions of such formations, terranes, or groups 

and still apply the original name, if the portion remaining is distinct or 

was first described and included under the name.

(/&) Geologic nomenclature should, in all its parts, be the natural 

expression of the inter-relationships and mutual subordination of the 

facts it is the especial aim to associate and systematize.1

CAMBRIAN.

The term Cambrian was first introduced to the attention of geologists 

at the Dublin meeting of the British Association for the Advancement 

of Science in August, 1835. A joint paper was read by Prof. Adam 

Sedgwick and E. I. Murchison, entitled " On the Silurian and Cambrian Systems, exhibiting the order in which the older sedimentary 

strata succeed each other in England and Wales." An abstract of this 

paper appeared in the account of the proceedings of the British Association published in the Edinburgh New Philosophical Journal for 

April-October, 1835, page 390. In this the name Cambrian is spelled 

Cumbrian, probably by a typographical error. The paper appeared in 

1836, in volume 5 of the Eeports of the Association. In the account of 

the Transactions of the Sections it says :2

Prof. Sedgwick commenced by pointing out the imperfection of the sections exhibited in the north of England and some portions of north Wales, in consequence of 

the entire want of continuity between the Carboniferous series and the interior schistose group. * * * Prof. Sedgwick then described in descending order the group 

of slate rocks as they are seen in Wales and Cumberland. To the highest he gave 

the name of Upper Cambrian group. It occupies the greatest part of the chain of the 

Berwyus, where it is connected with the Llandeilo flags of the Silurian system, and

'Oil the tripartite classification of the Lower Paleozoic rocks; Charles Lapworth, Geol. Mag., new 

series, doc. n, vol. 0,1879, p. 11. 

2 Brit. Assoc. Report for 1835, part 2, Trans. of Sections, 1830, p. 60.
238 THE CAMBRIAN. [BULL. 81.

is thence expanded through a considerable portion of south Wales. In one part of 

its course it is based on beds of limestone and calcareous slate, but on the whole it 

contains less calcareous matter than the Silurian system and has fewer organic 

remains. Beds of good roofing slate occur, and a perfect slaty cleavage is often 

observed in it transverse to the stratification, but other parts of it are of a coarse 

mechanical texture, To the next inferior group he gave the name of Middle Cambrian. It composes all the higher mountains of Caernarvonshire and Merionethshire, 

and abounds in fine roofing slate, alternating Avith and apparently passing into irregularly interstratified masses of porphyry. Some portions of it are coarse and mechanical, and it contains (for example at the top of Snowdon) a few organic remains 

and a few samples of highly calcareous slates, but no continuous beds of limestone. 

The same group, with the same mineral structure, and in the same position, but without organic remains, is greatly developed in Cumberland. The Lower Cambrian 

group occupies the southwest coast of Caernarvonshire and a considerable portion of 

Anglesea; it consists chiefly of chlorite schist, passing here and there into mica schist 

and slaty quartz rock and contains subordinate masses of serpentine and white granular limestone. It contains no organic remains.

In tliis first description, Archeau rocks are included in the lower 

division; the Middle Cambrian embraces the roofing slates, and the 

Cambrian group as now generally accepted; while the Dppjer Cambrian 

included much of the Lower Silurian of Sir E. I. Murchison, or the 

Ordovician of Prof. Charles Lapworth.

At a meeting of the Geological Society of London in the spring of 

1838, Prof. Sedgwick read a paper entitled "A Synopsis of the English 

series of stratified rocks inferior to the Old Eed sandstone, with an 

attempt to determine the successive natural groups and formations." 1 

When describing the sections of North Wales, etc., the chlorite slates, 

quartz rock, and mica slates of Anglesea and Caernarvonshire are not 

included in the Cambrian as was done in 1835.2 The Lower Cambrian 

system includes the old slate series of Caernarvonshire and Merionethshire, and ends with the calcareous beds, which range fromBala to the 

neighborhood of Dinas Mowddy.

The next group, the Upper Cambrian series, commences with the fossiliferous beds 

of Bala. It includes all the higher portion of the Berwyns, and all the slate rocks 

of South Wales, which are below the Silurian system. * * * Many of the fossils 

are identical in species with those of the lower division of the Silurian system, nor 

have the true distinctive zoological characters of the group been well ascertained.

In this arrangement, the Lower Cambrian of 1835 is referred to the 

primary stratified group, to which he gave the provisional name of Protozoic.3

It is further stated that at the north end of the Ber-wyn chain the 

Upper Cambrian appears to pass by insensible gradations into the 

lower division of the upper system, the Caradoc sandstone. Prof. 

Sedgwick does not appear to have been aware at this time that his Bala 

series was a portion of Murchison's Lower Silurian, as described by the 

latter in 1835.

Many geologists have insisted upon restricting the Cambrian to the 

Lower Cambrian of the scheme of 1835, which Prof. Sedgwick cut off

1 Proc. Geol. Soo., London, vol. 2,1838, pp. 675-685. 2 Op. cit., p. 685. . a Op. cit., p. 684.
WALCOTT.] NOMENCLATURE CAMBRIAN. 239

in the revision of 1838. It is also well to notice that the Cambrian of 

1838 includes exactly the same representative formations as Einmons's 

Taconic System of 1842-1860, or the Cambrian and Lower Silurian 

(Ordovician) as now known.

In 1852 we find the Lower Cambrian divided into theFestiniog group 

above and the Baugor below. The Bangor group is composed of the 

Llanberris slates and Harlech grits; and the Festiniog group of the 

Lingula flags, Tremadoc slates, and Areuig slates and porphyry, the 

whole having a thickness of 10,000 feet. The Upper Cambrian includes 

the Bala group, which was divided into the Lower and Upper Bala, 

with a thickness of 8,000 feet. Above this the Caradoc sandstone, 

limestone, and shale of the Silurian occur with a thickness of 1,500 

feet.1

In the paper on the Caradoc sandstone of Shropshire, by Messrs. J. 

W. Salter and W. T. Aveline, it is stated that the fossils of the supposed 

typical Caradoc sandstone are identical in species, and in association 

and proportionate numbers of the prevailing species, with those of the 

Bala group; and there is no admixture of other or new forms, or of 

those characteristic of higher parts of the system.2 By priority of 

definition and description, the Llandeilo and Caradoc beds belong to 

Murchison's Silurian system; and the- Bala series of Sedgwick are 

stratigraphically and paleontologically the equivalents of the Llandeilo 

and Caradoc series. They were fairly removed from the Cambrian 

system by the work of Messrs. Murchison, Sedgwick, and Salter; and 

in 1854 the Cambrian system included of the original Cambrian the 

middle member only, the lower division having been removed by Prof. 

Sedgwick in 1838. The distinguished founder of the Cambrian system 

did not admit the exclusion of the Bala series from the Cambrian, but 

with all the facts assembled, as in a recent paper by Prof. J. D. Dana,3 1 

think we are compelled to restrict the Cambrian to the original middle 

division.

The last tabulation given by Prof. Sedgwick of his Cambrian system 

appeared in the preface of Mr. J. W. Salter's Catalogue of Cambrian 

and Silurian Fossils in 1873, as follows: 4

( Upper Bala. 

Upper...... < Middle Bala.

( Lower Bala.

(Arenig or Skiddaw. 

J Tremadoc.

| Ffestmiog.

^Menevian.

( Harlech.

Cambrian: Middle....

Lower..... J anger. .....<

^Llanberris.

1 On the classification and nomenclature of the Lower Paleozoic rocks of England and WalesQuart Jonr. Geol. Soc., London, vol. 8,1852, p. 147.

* On the "Caradoc Sandstone" of .Shropshire. Quart. Jour. Geol. Soc., London, vol. 10,1853, p. 63.

3 Sedgwick and Murchiaon; Cambrian and Silurian ; Am. Jour. Sci., 3d ser., vol. 39,1890, pp. 167-180.

4 (On the classification of the Cambrian rocks). "Preface to a Catalogue of the Collection of Cam. 

brian and Silurian fossils contained in the Geologica,! l^useuin qf the University of Cambridge," by JW, Salter, 1873, p. xv,
240 THE CAMBRIAN. [BULL. 81.

With the exception of the Bala and Arenig series the system is essentially the same as that generally accepted by the English geologists at 

the present day.

As geologist of Tennessee, Dr. Gerard Troost read Sir E. I. Murchisoii's Siluria, and also the observations of Prof. Sedgwick on the Cambrian rocks of Wales. Discussing the changes in nomenclature made 

necessary in expressing the views of Messrs. Murchison and Sedgwick, 

he says in 1841: 1

After having pointed oat, in nay last report, the line of junction of the primordial 

or crystalline rocks in East Tennessee, I meptioned that the country west of the line 

which separates Tennessee from the State of North Carolina is composed of graywaeke, slate, limestone, etc. All this country, according to the views of Murchisou 

and Sedgwick, belongs to a new division, which they call the Cambrian system.

He then proceeds to describe the geographic distribution of the rocks 

that he referred to the Cambrian system, identifying the series in Tennessee with that of Wales entirely upon its lithologic characters and 

the absence of organic remains, and from the fact of its being succeeded by a series of limestones from which he obtained and identified 

Silurian fossils.

The presence of the equivalent of the Cambrian system in America 

was clearly recognized by Dr. E. Emmons, who, in 1844, wrote:

There are, however, if I understand Mr. Sedgwick and Mr. Murchison, rocks still 

lower; those which are now considered by them as metamorphic. They are the 

lower masses which I considered as equivalent to the Taconic rocks; the Lower 

Cambrian of S edgwick, and not the Upper, which latter I proved to belong to the 

New York system. That the Taconic slate is precisely that in which the Nereites in 

Wales occur, there is not the slightest doubt in my own mind, and this is that part of 

the Taconic system which we can see lying unconformably beneath the oldest member of the New York system, and hence of the Silurian also. I know not, however, 

whether in Wales the same limestones, slates, and quartz rocks are to be found which 

we have here, and which are the oldest parts of the Taconic system. These are facts 

to be determined. Their non-existence in Wales, however, does not destroy the system. Very important members are known there, and should the lower slates and 

quartz be found wanting, it only proves the absence of that development which is so 

well known here in New York, Massachusetts, Vermont, and Maine, and I may add, in 

Michigan also. 2

Under the influence of the publications of Sir E. I. Murchison, American geologists, other than Drs. Troost and Emmons and the latter's followers, classified all the Lower Paleozoic rocks under Lower Silurian, 

entirely ignoring Cambrian except to state that it was equivalent to the 

Lower Silurian. In 1872, however, Dr. T. S. Hunt published his history 

of the names Cambrian and Silurian in geology, advocating the recognition of the term " Cambrian." 3

1 Sixth annual report of the geological survey of Tennessee by the State geologist. Nashville, 1841, 

p. 171, doc. ed., p. 4 of special ed.

2 The Taconic System, 1844, p. v.

* Canadian Naturalist, new ser., vol. 6, 1872, pp. 281-312, 417-448., Geological Magazine, vpl, 10, pp. 

385-395, 453-461, 504-510, 561-566, 1873,
WALCOTT.I NOMENCLATURE CAMBRIAN. 241

The view of Dr. Hunt was concurred in by Sir J. W. Dawson, who in 

1872 wrote as follows:

I concur in the view that it may well have the name Siltiro-Cambrian, while the 

name Cambrian or Primordial will remain for thoso great and important fossiliferous 

deposits extending downward from the Potsdam in America and the Tremadoo in 

England, and constituting an imperishable monument to the labors of Sedgwick and 

Barrande. 1

A notice of the proposed change from "Potsdam or Primordial" of 

the first edition of Dana's Manual of Geology to "Primordial or Cambrian" in the second edition, was published in 1874; 2 and the term was 

used in a subordinate sense in another edition of the Manual of Geology 

(1876) as a subdivision of th,e Lower Silurian (p. 163).

The term " Cambrian " came into general use in the Canadian and Fortieth Parallel Surveys and in the U". S. Geological Survey in 1882. 

With the exception of a few that prefer to use Taconic, the term is generally employed by geologists of all countries.

Most of the English geologists of the present time draw the line between the Cambrian and Silurian at the summit of tbe Tremadoc and 

the base of the Arenig terranes. From a study of the list of genera and 

species of the fauna of tbe Lower and Upper Tremadoc slates, I think 

tbat the line of demarkation between the two systems would naturally 

fall between these two subdivisions of the Tremadoc. The fauna of the 

Lower Tremadoc, in its general facies, is essentially the type of the 

Cambrian fauna, and there are only a few genera and species more characteristic of tbe Silurian. The large fauna of the Upper Tremadoc slate 

is characteristic of the Lower Silurian and the presence of a few genera 

and species of essentially Cambrian type are not sufficient to include it 

in the Cambrian. The fact that there is a slight unconformity at the 

summit of the Tremadoc and the base of the Arenig is not of sufficient 

general importance to warrant the placing of the line of demarkation 

between the groups at this horizon.

In a table showing the classification of the British sedimentary rocks, 

by Prof. A. J. Jukes Brown,3 the Tremadoc slates are placed in a stage 

between the Cambrian and Ordoviciau.

This view of the Tremadoc slates was held by Mr. J. W. Salter,4 who 

wrote:

But a few words must be said about this band of slate, which so intimately connects the Lingnla flags below with the rocks above, and which is nevertheless so distinct in fossil characters from either.

'Cannd. 'Nat., new ser., vol. 7, 1873, p. 7.

2 Dana, J. D. lloasons for some of the changes in -the subdivisions of geological time in the new 

edition of Daua's Manual of Geology. Am. Jour. Sci., 3d ser., vol. 8, 1874, p. 213.

, 3 The classification of stratified rocks. Geol. Mag., new ser., dec. in, vol. 2, 1885, p. 297.

4 Memoirs of the Geological Surveys of Groat Britain. Geology of North. Wales, second edition, 

1881, p. 355.

Bull. 81 16
242 THE CAMBRIAN. [BULL. 81.

Dr. Henry Hicks 1 says of it:

The Tremadoc group, therefore, may be said through many of its types of fossils to 

link the Cambrian and the overlying Ordovician (Lower Silurian) formations together, while it yet marks very distinctly the horizon in which all the truly characteristic types in the Primordial faunas are lost.

TACONIC.

The first proposition to apply the name Taconic to a system or series 

of rocks is found in a gazetteer of the State of New York, published in 

1842.2 The article is unsigned, but it bears internal evidence of having 

been written by Dr. Ebenezer Emmons as his first presentation of the 

views which were more fully elaborated and published later in the same 

year. He describes the Taghkanic range, and states that the rocks 

composing the same are situated between the gneiss of Hoosic Mountain on the east and the slates of the transition on the west; that they 

bear a very close resemblance to the primary on the east, and, on the 

other hand, a great similarity to the transition slates on the west.3

He says:

It is not proposed in this plan to separate these rocks from the primary, but to 

consider them as belonging to the upper portion and to speak of them as the Taghkanic rocks, or perhaps as the Taghkanic system. * * * Considering them for the 

present as belonging to the upper portion of the primary, the Taghkanic rocks will 

be composed, first, of a peculiar talcose slate, or a magnesian slate in part; in 

other parts it is plumbaginous, which strongly soils the fingers. * * * Second, of 

white, gray, and clouded limestone varying in texture from fine to coarse granular, 

often interlaminated with slate, the latter often merely coloring the limestone so as 

to impart the clouded appearance. * * * Third, of granular quartz, or a sandstone 

generally siliceous and of a brown color. 4

In the concluding remarks on the Taghkanic system, we read:

On the whole, in regard to those rocks we have denominated "Taghkanic," we believe they ought to be separated from those on the east, being, as a whole, clearly 

distinct from them.5

A second memoir appeared in 1842, in which the term " Taghkanic " is 

changed to Tacouic, and a detailed description given of the geographic 

distribution and character of the rocks forming the Taconic system. 

A typical section is presented with the following comment : 6

The following section, extending from Petersburgh, Rensselaer County, to Adams, 

Massachusetts, embraces all the rocks in this system. Its direction is nearly east 

and west, or perpendicular to the strike of the system over which it passes.

1 On some recent researches among Lower Paleozoic rocks in the British Islands. Proc. of the 

Geologists' Association, vol. 7, p. 9.

3 Topography, geology, and mineral resources of the State of New York. Gazetteer of the State of 

New York, by James Disturnell. Albany, 1842, pp. 5-25. 

3 Op.cit.,p. 11.

4 Op. cit., p. 11. 

B 0p.cit.,p.l2.

6 Geology of New York, part 2, comprising the survey of the 2d geological (northern) district, 1842, 

p. 145.
WAWOTT.] NOMENCLATURE PRIMOEDIAL. - 243

In. 1844, a separate memoir 1 was published in which a great addition, 

was made to the Taconic system west of the Petersburg end of the 

section of 1842. This addition was in 1856 2 separated as the Upper 

Tacouic.

TAGONIAN.

This name was proposed by Dr. T. S. Hunt, in 1877, to include the 

Lower Taconic of Dr. Bmmons,3 or the Granular Quartz, Berkshire 

limestone, and Taconic slates of the latter's typical Taconic section of 

1842. At the time of the proposal of the name the author was uncertain whether the strata included under it should be referred to the basal 

beds of the Cambrian or to a pre-Cambrian system of rocks.

In a later paper he refers the Taconian system of the Appalachians 

to a pre-Cambrian horizon as compared with the Cambrian rocks from 

that region. This is stated by him as follows: "This Appalachian-Cambrian series is wholly uncrystalline, and is separated from the Taconian 

by a stratigraphical break, and by a great interval of time, which includes the Keweenian period." 4 As we now know that the Granular 

Quartz is characterized by the Lower Cambrian or Olenellus fauna, the 

Berkshire or Stockbridge limestone by the Chazy-Trenton and perhaps 

at its base by an Upper Cambrian fauna, and the original Taconic slate 

of the Lower Taconic of Dr. Emmons is correlated by its stratigraphic 

position >ith the Hudson shales, the term Tacouian ceases to be of 

value in geologic nomenclature.

PRIMORDIAL.

This name was used by M. J. Barrande to designate the First fauna, 

in contradistinction to the Second and Third.5

The name was applied at first to the" fauna, but, in 1854, in the first 

edition of " Siluria," Sir Eoderick Murchison designated the formation 

containing the Primordial fauna as the Primordial Silurian, dividing 

the Silurian into the Upper Silurian, the Lower Silurian, and the 

Primordial Silurian. The use of the latter term has been advocated more 

or less by those who oppose the use of the term Cambrian ; but the 

name Primordial is now rarely used except when mentioning the First 

fauna of Barrande.

1 The Taconic System; based on observations in New York, Massachusetts, Vermont, and Rhode 

Island. Albany, 1844, pp. i-vii. 67.

2 Emmons,; Ebenezer. American Geology, containing a full statement of the principles of the 

science, with full illustrations of thecharacteristic American fossils. Albany, 1856, vol. 1, pt 2, pp. 49-66.

3 On the geology of the Eozoic rocks of North America. (Abstract). Boston Soc. Nat. Hist., vol. 19 

1878, p. 278.

*Hunt, T. Sterry. The Taconic Question in Geology. Mineral Physiology and Physiography. A 

second series of chemical and geological essays. With general introduction. 1886, p. 677.

 Systeme Silurieii du centre de la Boheuie, vol. 1, 1852, p. 88.
244 THE CAMBEIAN. [BULL. 81.

POTSDAM.

There are several early references to a sandstone occurring at the 

base of the section in the Upper Mississippi Valley and about the Adirondack Mountains in New York ; but it was not until 1838 that it was 

well defined and given a distinct name. This was done by Dr. E. Emmons. In describing this sandstone, Dr, Emmons says:*

I shall not enter upon its geological relations any farther than to state (hat, in 

Potsdam and other towns in which it appears, it uniformly rests on the primary 

strata; and in no part of the county is there any rock which interposes itself between 

it aud the primary, so that it appears here as the oldest representative of the transition series. The identification of this rock -with the sandstones along the southern 

border of Lake Ontario will be a matter of some difficulty. It is geologically below 

the transition limestone, and never in the northern district alternates with it, bat 

always holds the relation of an inferior rock. * * *

This rock is a true sandstone, of a red, yellowish red, gray, and grayish white colors. 

It is made up of grains of sand, and held together without a cement. Intermixed wi th 

the siliceous grains are finer particles of yellowish feldspar, which do not essentially 

change the character of the sandstone, but they show the probable source from which 

the materials forming it were originally derived, viz, some of the varieties of granite

On the Lake Champlain side of the Adirondacks it is described as 

follows:

Its position is evidently beneath the transition limestone and calciferous sandrock. 

It is very deficient in organic relics, though not entirely destitute of them. It is 

unnecessary to repeat what has already been said of this rock; it is purely quartzose 

or siliceous in its composition and finely stratified. It dips to the northeast at Port 

Kent at an angle varying from 5° to 10°. The places where it occurs along Lake 

Champlain are indicated on a map of apart of this [Clinton County], to which I refer 

the reader. This rock at Keeseville has been rent in the most remarkable manner; 

several fissures, the principal one of which extends nearly a mile, and through which 

the Au Sable flows, have been opened by some convulsion in nature to the depth, in 

some places, of a hundred feet and from five to twenty wide. Near the bottom of the 

fissure at High Bridge, as it is called, I discovered numerous specimens of a small 

bivalve molusca, a lingula. I found, also, on examination, that the same fossil 

occurred'through an extent of 70 feet at least, and so far as 1 could discover, it was 

the only fossil inclosed in the rock. It is extremely thin and delicate, yet the shell 

is perfectly preserved, and is probably one of the oldest inhabitants of the globe, as 

the rock in which they occur is the oldest of the transition series. 2

The name "Potsdam sandstone" was quickly accepted by the New 

York State geologists, incorporated in their annual reports, and used in 

the final report on the geology of the State. The extension, by correlation, of the name to the Southern Appala«hians, through Pennsylvania, Virginia, North Carolina, Tennessee, and Alabama; westward 

through the Mississippi Valley and the Kocky Mountains, and north 

into Canada, and down the St. Lawrence Valley, rapidly followed, until 

the name Potsdam is now used to typify the Upper Cambrian zone in 

all parts of America.

 Eeport of the geologist of the 2d geological district of New York. Second annual report of the Geological Survey of N. Y. Albany, 1838, pp. 214 215.

*0p.cit.,p.23l).
WALCOTT.J NOMENCLATURE. 245

ST. CKOIX.

The name St. Croix was proposed by Prof F. H. Winchell in 1873 

for the fossiliferous sandstone beneath the Lower Magnesian limestone 

of the Mississippi Valley. The reason given is that the sandstone identified by Dr. D. D. Owen as the Potsdam sandstone is unconformably 

superjacent to a series of quartzites in Wisconsin and Minnesota that 

are the true equivalents of the Potsdam sandstone of New York.1

The presence of the same fauna in the typical Potsdam sandstone on 

the northern side of the Adirondack Mountains as that found in the 

upper sandstone of St. Croix Falls negatives this view and correlates 

the sands tones that are unconformably superjacent to the lower quartzites with the typical Potsdam, and refers the lower quartzites to the 

Algonkiasi. The name St. Croix, however, is retained for the fossiliferous 

Cambrian sandstones of the upper Mississippi Valley in Wisconsin, 

Iowa, and Minnesota.

MADISON.

The name Madison sandstone was proposed by Prof. R.®D. Irving,2 in 

1877, for a band of sandstone consisting, in large part, of nearly pure 

white quartz sand, with a thickness of 35 to 50 feet, and lying between 

the base of the Magnesian limestone of the Lower Silurian (Ordovician) 

and the Mendota limestone in Wisconsin.

MENDOTA.

This name was proposed by Prof. E. D. Irving, in 1877, for a calcareous stratum near the upper portion of the " Potsdam " formation of 

Wisconsin. It is formed of alternating sandy and calcareous material 

that, in the upper portion, is almost a well marked and very persistent 

yellow limestone layer, with a thickness of 30 feet.3

TONTO.

This name was applied by Mr. G. K. Gilbert, in 1874,4 to a series of 

sandstone and shale between the subjacent granite and the superjacent 

massive limestones that occur in the section at the mouth of the Grand 

Calion of the Colorado River, Arizona. He considered the formation 

of Primordial age, and it has since been found to contain an Upper 

Cambrian fauna. It was more fully described by him in the following 

year.5

1 General sketch of the geology of Minnesota. Geol. and Nat. Hist. Survey, Minnesota, 1st Ann. 

Hep. for 1872,1873, pp. 70-72.

2 The Lower Silurian rocks. (Geology of central Wisconsin.) G eol. Wisconsin, survey of 1873-1879, 

vol. 2,1877, p. 525. 

" Ibid., 525.

4 On the age of the Tonto sandstone. (Abstract.) Washington-Phil. Soc. Bull., vol. 1,1874, p. 109. 

e Explorations and surveys west of the 100th Merid., vol. 3,1875, p. 163; pp. 521-522.
246 THE CAMBRIAN. [BULL, a."

HAMBURG.

The Hamburg limestone and the Hamburg shale are names used by 

Mr. Arnold Hague, in 1881, to designate the Upper Cambrian limestone 

and shale of the Cambrian section of'the Eureka district, Nevada. The 

limestone is superjacent to the Secret Canon shale and subjacent to 

the Hamburg shale. The latter is characterized by a well developed 

Upper Cambrian fauna.1

SECRET CANON.

This name was applied by Mr. Arnold Hague, in 1881, to a band of 

shale in the Cambrian section of the Eureka district, superjacent to the 

Prospect Mountain limestone and subjacent to the Hamburg limestone, 

characterized by a fauna that may be referred to the upper portion of 

the Middle Cambrian.2

KATEMCT.

Prof. Theodore B. Comstock, in describing the Upper Cambrian rocks 

of the central area of Texas, proposed the name "Katemcy" for the 

"Potsdam series," or Upper Cambrian.(?)3 This terrane is named from 

the beds exposed in the valley of Katemcy Creek, Mason County.

RILEY.

This name was proposed by Prof. Theodore B. Comstock, for a series 

of sandstones which he considered to be superjacent to the Hickory 

series of the Central Texas, Cambrian section, and subjacent to the 

Katemcy or Potsdam series. He referred it provisionally to the Middle 

Cambrian zone.4

HICKORY.

This name was proposed by Prof. Theodore B. Comstock, for a series 

of strata that he considered to underlie the typical Potsdam Sandstone 

of the central Texas section. He referred the series provisionally to 

the Lower Cambrian.5

CONNASATJGA.

This name was proposed by Mr. 0. Willard Hayes, for the Cambrian 

shales at the summit of the Cambrian section in northwestern Georgia. 

He correlated it with the Knox shale of Safford's Tennessee section, 

assigning to it a thickness of 1,600 to 2,000 feet.6

1 Eeport (on work in Eureka District). U. S. Geol. Surv., 2d Ann. Kep., 1880-'81,1881, p. 27; 3d Ann. 

Eep., 1883, p. 255. 

2 Ibid., pp. 27, 253.

3 Comstock, T. B.: A preliminary report on the geology of the central mineral region of Texas. 

First Ann. Kept. Geol. Surv. Texas, 1889, p. 289.

4 Ibid., p. 286. 

* Ibid., p. 285.

6 The overthrust faults of the southern Appalachians. Bull. Geol. Soc. America, vol. 2, Feb. 1891, p. 

143, pi. 3.
VTALCOTT.] NOMENCLATURE. 247

This name seems to be a synonym of Montevallo shales proposed by 

Prof Eugene A. Smith.

MONTEVALLO.

The name Montevallo, or Choccolocco, shales was proposed by Prof. 

Eugene Smith, for a series of sandy shales of a great variety of colors, 

such as olive, green, brown, chocolate, yellowish, etc., that occur above 

the Coosa shales in northeastern Alabama.1

This name appears to be equivalent to Connasauga shales proposed 

by Mr. C. Willard Hayes.

CHOCCOLOCCOo

This is apparently a synonym of Montevallo.

COOSA,

t The name Coosa shales was proposed by Prof. Eugene A. Smith for 

the shales in the Coosa Yalley at the base of the Cambrian section. 

They are described as thin-bedded limestones with clay seams between.2

This name is also used by Mr. C. Willard Hayes in a paper read before the Geological Society of America, December 29,1890, arid published February 9,1891. It was applied to the series of shales, some 

3,000 feet in thickness, occurring at the base of the Cambrian section 

in northwestern Georgia.3

ROME SANDSTONE.

This name was proposed by Mr. C. Willard Hayes for a sandstone of 

Cambrian age occurring at Eome, Georgia. In connection with the 

Weisner quartzite it is given a thickness of from 2,000 to 3,500 feet. 

The correlation is with the Knox sandstones of Tennessee.4

BRETONIAN.

This name is applied by Mr. G. F. Matthew to the upper series of 

Cambrian rocks as found in the vicinity of St. John, New Brunswick, 

and on the island of Cape Breton, where the fauna of the division is 

well developed. It will be arranged as an Upper Cambrian formation.5

1 Geological structure and description of the valley region adjacent to the Cahaba Coal Field. Gool. 

Surv. Alabama. Keport on the Cahaba Coal Field, pt. n, 1890, p. 148. (Issued January, 1891.)

* Ibid., p. 148.

3 The ovorthrnst faults of the Southern Appalacians. Bull. Geol. Soc. America, vol. 2, Feb., 1891, 

p. 143, pi. 3.

«lbid.,p,143.

"Illustrations of the fauna of the St. John group, No. 5. Trans. Roy. Soc. of Canada, vol. 8, 1890, 

p. 129.
248 THE CAMBRIAN. [BULL.81.

ACADIAN.

The name Acadian was proposed by Sir J. W. Dawson in 1867 foi 

the series of rocks represented in New Brunswick by the St. John slate 

of Mr. G. F. Matthew.1 In 1868 these observations were reprinted, 

with the statement that the discovery adds a new formation to the Paleozoic period in America. He says:

This formation has as yet been known as the " St. John group," but I think this 

name unsuitable, both on account of the number of places known as St. John and on 

account of the variety of formations occurring near St. John, in New Brunswick, and 

 would propose for the group now under consideration, characterized by Paradoxides, 

Conocep halites, etc., and the oldest known member of the Paleozoic of America, the 

name Acadian group, by which I hope it will be known to geologists in whatever part 

of America it may be recognized.'2

In a recent paper on the fauna of the St. John group, Mr. G. F. Matthew limits the term Acadian to his Division 1 of the New Brunswick 

Cambrian section. This includes the fauna of the Paradoxides zone.3

ST. JOHN'S.

Prof. J. Beete Jukes in 1843 4 used the name St. John's slate for the 

slate as seen near St. John's, Newfoundland, beneath the Signal Hill 

sandstone. When referring, in 1862, to this work 5 he states he did not 

find any fossils in the lower slate formation, but that Mr. G. Bennett, 

subsequently found trilobites of the genus Paradoxides in the slates on 

the west side of St. Mary's Bay. These were named P. bennetti by Mr. 

J. W. Salter. On the map accompanying the report of 1813, the slates 

of St. John's extend southward from St. John's and around the southern 

point of the Avalon Peninsula to and about the Bay of St. Mary's.

The investigation of Dr. Alexander Murray and Mr. J. P. Howley in 

connection with the geological survey of Newfoundland, have shown 

that the slate carrying Paradoxides about St. Mary's Bay is a later 

formation than the slate at St. John's 5 and that the Paradoxides slates 

are unconformably superjacent to the slates to which Prof. Jukes gave 

the name of St. John's in 1843. This restricts the name as given by 

Prof. Jukes to the slate series of St. John's, described as from 2,000 

to 3,000 feet thick. It was in this series of slates that the Rev. 

Moses Harvey discovered the fossil which Mr. Billings described as 

Aspidella terranovica. The entire series, along with the Signal Hill 

sandstone of Prof. Jukes, was referred to the intermediate or Huronian

1 On recent geological discoveries in the Acadian provinces of British America. Proc. Am. Assoc. 

Adv. Sci., vol. 1C, 1867, pp. 117-119.

2 Acadian geology. The geological structure, organic remains, and mineral resources of Nova Scotia, New Brunswick, and Prince Edward Islands. 2d ed., London, 1868, p. 638.

3 Illustrations of the fauna of the St. John Group No. 5. Trans. Hoy. Soc. of Canada, vol. 8, 1891, 

p.129.

4 General report of the geological survey of Newfoundland in 1839 and 1840. London, 1843, p. 59.

* The Student's Manual of Geology. 2d edition, Edinburgh, 1862, p. 457.
AVALCOTT.] NOMENCLATUEE. 249

system by Dr. Murray; and in the classification used in this memoir 

it is included under the Algonkian, as a pre-Cambriau formation.

In proposing a classification for the formations in the vicinity of St. 

John, New Brunswick, Mr. F. G. Matthew proposed the term, "St. John 

group " for several zones of soft black and dark gray, finely laminated 

shales alternating with zones of coarser grained slates, containing numerous thin beds of fine-grained sandstone.1 The fossils were Lingula, a 

Conchifer, Annelids, and Coprolites. This was republished in 1865, and 

is used in all the latest publications by Mr. Matthew.

In view of the fact that the term " St. John's" was used for a distinct 

formation by Prof. Jukes in 1843, it appears best to continue to apply 

it to these slates of the Algonkian ; and to use the later name "Acadian " for the slates at St. John, New Brunswick.

JOHANNIAN.

This name is proposed by Mr. G. F. Matthew for a local series of 

strata in the St. John basin of New Brunswick that occur between the 

Paradoxides zone, or Division No. 1, and the Upper Cambrian Zone, or 

Division No. 3, which he calls Bretonian.2

GEORGIA.

The name Georgia was incidentally used by Prof. Jules Marcou in 

I860, when stating that " Prof. Emmons has always regarded the black 

slates of Georgia as a part of his Tacouic system."!' In the following 

year the name was used in volume 1 of the Geology of Vermont, in the 

systematic description of a group of formations, the typical one of 

which is a series of slates and shales above the " Red saudrock" in the 

town of Georgia, Termout. There was also included in the group the 

roofing slate belt of Rutland County, Vermont, that passes into Washington County, New York. A provisional reference was made of a 

series of clay slates that occur in the central part of the State.4 A full 

description of the formations referred to the group is given in the text, 

and their geographic distribution is delineated on an accompanying 

map.

Prof. Jules Marcou advanced the claim that he first used the name 

Georgia in October, 1860, which was followed in December, 1861, with 

a full definition of the group.5 Prof. Hitchcock in reply to this, states

1 Mattbew, G-. F.: Observations- on tbe geology of St. John County, New Brunswick. Canadian 

Nat. vol. 8,1863, p. 244.

2 Illustrations of the fauna of tlie St. John Group No. 5. Trans. Roy. Soc. of Canada, vol. 8,1891, 

p. 129.

3 On the Primordial Fauna and the Taconio System, by Joachim Barrande, with additional notes by 

Julea Marcou, Proc. Boston Soc. Nat. Hist., vol. 7,1860, p. 375.

4 Hitchcock, C. H. Geology of Vermont, vol. 1, p. 357.

0 The Taconic of Georgia and .the Keport on the Geology of Vermont. Memoirs Boston Soc. Nat. 

Hist., vol. 4,1888, pp. 123,124.
250 THE CAMBRIAN. [BUI.UM.

that excerpts from volume 1 of the Geology of Vermont were distributed 

prior to December, 1861, and that it was in print by July, 1861. 1

On a map, in the atlas accompanying the Geology of Canada for 18G3, 

published in 1865, the Georgia group of Prof. Hitchcock is included 

with the " Eed Sandrock " in a common color, and is so referred to in 

the legend. This includes the " Eed Sandrock" series and the Geor. 

gia series of Prof. C. H. Hitchcock as one formation under the name 

of Potsdam.

In 1886 the "Ked Sandrock" was included by Mr. C. D. Walcott 

with the shales of the Georgia series, in the Middle Cambrian or Georgia group.2 The reference to the Middle Cambrian was changed to 

Lower Cambrian three years later.3

GRANULAR QUARTZ.

This is one of the first formations differentiated and named by Prof. 

Amos Eaton.4 He referred it to the Primitive class and indicated its 

stratigraphic position on a section accompanying the index. The name 

was accepted by Dr. E. Emmons5 in 1842 and placed as the second 

member of his Taconic system, between the second bed of Stockbridge 

limestone and the third bed of limestone. This section was corrected 

in 1844, so as to place the "Granular Quartz" at the base of the Taconic 

system.6

In 1887 the Oleuellus fauna was discovered by Mr. C. D. Walcott in 

the " Granular Quartz " near Bennington, Vermont, thus determining 

its pre-Potsdam age.7

RED SANDROCK.

The occurrence of a red sandstone at Burlington Falls, Vermont, was 

mentioned by Prof. C. T. Jackson in 1844.8

Iii the scheme of Dr. C. B. Adams, illustrating the rock s of Vermont, 

as expressed in the nomenclature of the New York system, the Ked 

Sandrock occurs above the Hudson Eiver shales.9

The correlation thus indicated is that of the reddish brown Medina 

sandstone of the New York series with the reddish colored "sandstone" 

of Vermont, and the name Eed Sandrock was applied to the latter, 

thus originating a term that has continued in geologic literature, not1 Date of the publication of the report upon the Geology of Vermont. Boston Soc. Nat. Hist. Proc., 

vol. 24,1888, p. 34.

2 IT. S. Geol. Survey, Bull. No. 30,1886, p. 44.

3 Stratigrapliic position of the Olenellus Fauna in North America and Europe. Am. Jour. Sci., 3il 

eer., vol. 37,1889, p. 383.

4 An index to the Geology of the Northern States, with a transverse section from Catskill Mountain 

to the Atlantic. Leicester, 1818, p. 21.

6 Geol. of N. Y., Part 2, comprising the survey of the 2d Geol. (Northern) District, 1842, p. 144. 

0 The Tacouic System; based on observations in New York, Massachusetts, Vermont and Rhode Island. Albany, 1844, p. 18.

7 Discovery of fossils in the Lower Taconic of Emmons. Am. Assoc. Proc.,vol. 30,1888, p. 212, 

 Final report on the Geology and Mineralogy of the State of New Hampshire, 1844, p. 161. 

9 First Ann. Rep. on the Geology of Vermont. Burlington, 1845, p. 61.
WALCOTT.] , NOMENCLATIVE. 251

withstanding tlie fact that the rock itself is a magnesian limestone, 

with more or less siliceous and sandy beds alternating with the limestone,

In the second annual report of Vermont by Dr. Adams, in the description of a section of Snake Mountain, Addison County, the strata capping the mountains are designated by the name of Bed Sandrock.1

PRIMAL.

The term Primal was proposed by the brothers Rogers in 1844 and 

defined as follows:

Our Primal series embraces the four great rocks between the base of the Paleozoic 

strata and the base of the first limestone, the Calciferons sandstone of New York. 2

The equivalent expression was Formation Fo. 1, and both terms have 

been used in the geologic work of Pennsylvania, Maryland, and Virginia, but they have not come into general use.

CHILHOWEE.

The name Ohilhowee was proposed by Prof. J. M. Safford in 1856 for 

a series of sandstones and shales superjacent to the Ocoee conglomerates and shales and subjacent to the Magnesian limestone and Shale 

group, or what was subsequently called the Knox shale and the Kuox 

limestone.3

By the discovery of the Olenellus fauna in the shale resting upon the 

quartzite of Chilhowee Mountain, the Chilhowee Mountain quartzite is 

referred to the Lower Cambrian and correlated with the Granular 

quartzite upon the western slope of the Green Mountains of Vermont.

WEISNEE.

This name is proposed by Prof. Eugene A. Smith for the lenticular 

masses of quartzite that occur in the Montevallo shale of northeastern 

Alabama. He correlates the quartzite with the Chilhowee Mountain 

quartzite of Tennessee. This correlation is, probably incorrect, as the 

latter quartzite is of Lower Cambrian age.4

This name is also used by Mr. C. Willard Hayes for a series of quartzites that occur between the Coosa shales and the Counasauga shales 

of the Cambrian section of northwestern Georgia. In connection with 

the Home sandstone he mentions the correlation of it with the Knox 

sandstone, Potsdam or Chilhowee, Prof. Safford's Tennessee section, 

by Profs. Smith and Safford.5

1 Second Ann. Hep. of Geol. Surv. of Vermont, 1846, p. 163.

2 On American geology and present condition of geological research in the United States. Am. Jour. 

Sci., vol.47,1844,p.]55.

3 A geological reconnaissance of Tennessee; first triennial report. Nashville, 1856, p. 152.

"Geological structure and description of the valley region adjacent to the Cahaha Coal Field. Geol. 

Surv. Alabama. Kept, on the Cahaha Coal Field. Ft. n, 1890, p. 149.

5 The overthrust faults of the southern Appalachians. Bull. Goal, Soc. America, vol. 2, Feb., 1891, 

p.U3.
252 THE CAMBRIAN. [BULL. 81.

OCOEE.

This name was proposed by Prof. J. M. Safford in 1856 for a series of 

conglomerates and slates that he considered to be superjacent to the 

Mica-slate group and subjacent to the Chilhowee sandstone.1

PROSPECT.

For the lower members of the Cambrian section, in the Eureka district, Nevada, Mr. Arnold Hague proposed, in 1881, Prospect Mountain 

quartzite and Prospect Mountain limestone.2 As now known the upper portion of the Prospect Mountain quartzite is characterized by the 

Olenellus or Lower Cambrian fauna, and the Prospect Mountain limestone by the Middle Cambrian fauna of the Eocky Mountain section.

EASTERN AND WESTERN SANDSTONE.

These names were applied to the horizontal, evenly bedded sandstones of the south shore of Lake Superior, east and west of Keweenaw 

Point, by Dr. E. D. Irviug in 1883 as convenient terms under which to 

describe the character of the sandstone and its geographic distribution.3

LAKE SUPERIOR SANDSTONE.

Dr. J. J. Bigsby described the red and white sandstone along the 

south shore of Lake Superior as early as 1825, and in the account of 

the geology of Lake Superior by Capt. H. W. Bayfield, he speaks of 

the sandstones of Lake Superior.4 As used by Capt. Bayfield, the Lake 

Superior sandstone included both the Cambrian sandstones of the south 

shore, and the pre-Cambrian sandstones of Keweenaw Point and the 

north shore of the Lake. It has been used by various authors in the 

same general manner, and has little value as a term in stratigraphic 

geology.

POTSDAMIO.

Prof. C. H. Hitchcock proposed in 1888 for the rocks5 containing the 

Cambrian fauna, the name Potsdamic or Taconic.

1 A geological reconnaissance of Tennessee; first biennial report. Nashville, 1856, p. 151. 

2 U.S.Geol.Survey, Second Ann.Kep., 1880-'81, 1882,p. 27; 3d Ann.Kep., p.254.

3 The copper-bearing rocks of Lake Superior. TJ. S. Geol. Survey, Monograpb, vol. 5; 1883, pp. 351,365.

4 Outlines of the Geology of Lake Superior. Quebec Lit. and Hist. Soc. Trans., vol. 1,1829, pp. 15-22. 

6 Date of the publication of the report iipon the Geology of Vermont. Boston Soc. Nat. Hist. Proc. 

vol. 24,1888, p. 37.
CHAPTER IV.

SUMMARY OF THE PRESENT KNOWLEDGE OF THE FORMATIONS.

The data under this heading is assembled for each of the following 

Geologic Provinces:

Atlantic Coast Province. 

Appalachian Province. 

Kocky Mountain Province. 

Interior Continental Province.

A brief re'sume' is given at the end of the description of the formations of each province and a general re'sume' of the Cambrian Group at 

the end of the chapter.

* ATLANTIC COAST PROVINCE.

This includes the rocks referred to the Cambrian group on the Island 

of Newfoundland and the adjoining coast of Labrador, the provinces 

of Nova Scotia and New Brunswick, and Cape Breton, and the States 

of Maine, New Hampshire, and eastern Massachusetts.

NEWFOUNDLAND AND THE ADJOINING COAST OF LABRADOR.

The detailed knowledge we have of the Cambrian rocks of Newfoundland is obtained largely from the publications of the Geological Survey 

of Canada for the northwest and west coast and the Labrador coast, 

and from, the descriptions by the Newfoundland Survey of the eastern 

and southeastern coast. To the latter there is added the results of a 

season's work on the Ayalon peninsula, by the writer.

NORTHWESTERN NEWFOUNDLAND.

The Cambrian strata on the adjoining coast of Labrador are included 

with those of the Cambrian area of northwestern Newfoundland, as 

the two are considered to belong to one geologic province.

The section at L'Ause au Loup, on the north side of the straits of 

Belle Isle1 shows 231 feet of arenaceous beds at the base, overlain by

"Logan, "W. E.: Geological Survey of Canada; report of progress iroin its commencement to 1863. 

Montreal, 1863, p. 288.

253
254 THE CAMBKIAN. [BULL.81.

143 feet of gray, reddish and greenish limestones. The section is, in 

detail, as follows:

Feot.

1. Red and gray sandstones, sometimes of a reddish gray; consisting, in the 

lower part, of a conglomerate composed of rounded pebbles of white quartz 

from an eighth of an inch to 3 inches in diameter, in a matrix of fine-grained 

sandstone, made up of whitish and reddish quartz, and white and red feldspar. A similar fine-grained mixture constitutes the great mass of rock in 

the upper part. The beds vary in thickness from 3 inches to 3 feet, and many 

of them are penetrated vertically by Soolithua linearis, about a quarter of an 

inch in diameter, and always of a lighter color than the surrounding mass. 

Four feet below the summit there is a bed 3£ feet thick, of a mammillated or 

concretionary character; the concretions, which are from 1 to 10 feet in horizontal diameter, being composed of concentric layers from a quarter to half 

an inch thick ............................................................. 231

2. Gray, reddish, and greenish limestones, presenting on the strike great diversities of character. They sometimes consist of yellow-weathering, massive, 

nodular, argillaceous limestones, probably magnesian, holding lenticular 

patches of pure limestone, as well as of red and green shale from 3 to 6 

feet in horizontal diameter. On the strike these yellow-weathering limestones pass in some parts into gray, compact, pure limestone, in thick, 

massive beds, while in others they are evenly divided into layers of only 2 

or 3 inches thick. In Forteau Bay the whole mass appears to be more or 

less fossiliferous .......................... ............................. 143

374

I examined the Collections from these limestones now in the Canadian 

Geological Survey collections, and found the following species, most of 

which had been recognized and described by Mr. Billings :

Palteophycus incipiens. 

Archteocyathus profundus. 

Spirocyathes atlanticus. 

Coscinocyathus billingsi. 

Iphidea bella. 

Kutorgina cingulata.

labradorica. 

Obolella chromatica. 

Orthis 2 sp.

Stenotheca elongata.

rugosa.

Hyolithes billingsi. 

Salterella pulchella.

rugosa.

Olenellus thompsoni ? 

Ptychoparia miser. 

Protypus senectus. 

Solenopleura (like S. nam

In describing the extension of the rocks along the north shore of the 

Straits of Belle Isle, Sir William E. Logan states that they rest on the 

Laurentian gneiss, and extend along the coast for nearly 80 miles, with 

a probable breadth of 10 or 12 miles, and slope towards the water at an 

average of about 60 feet to the mile. In this stretch along the coast 

they are divided into five or six tabular masses, separted from one another by narrow denuded portions of the gneiss. 1

On the Newfoundland shore sandstones occur that were referred to 

the Potsdam sandstone from their stratigraphic relations to superjacent limestones containing Lingulepis acuminata? The data, however, 

does not fully sustain this reference. Following south along the west

1 Op. oit., p. 287, a Op. cit, p. 289,
WALCOTT.I SUMMARY NEWFOUNDLAND. 255

coast nearly 200 miles, to Bonne Bay, a more extended section of Cambrian strata is met with that is described in detail, as follows i 1

Between 1 and 2 miles inland from the northeast side of the oast arm of Bonne 

Bay there arises a range of hills of Laurentian gneiss, 2,000 or 3,000 feet in height, 

on the flank of which is exposed the following measured section :

A.

.Feet.

1. Blackish blue, fine-grained slate, with a cleavage independent of the bcd- 

. ding. Of this slate only 105 feet of the upper part are seen; the lower 

part is concealed in the space between the upper portion and the gneiss, 

and may comprise a thickness of about 230 feet........................... 335

2. Blackish blue slate interstratified with gray quartz t tea, in beds of from 6 

inches to 3 and 4 feet. In the 80 feet at the bottom the qnartzites 

greatly predominate, and they constitute 15 feet at the top, while the intermediate 176 feet consist chiefly of slate............................... 270

B.

1. Light gray, yellow-weathering limestone, in beds of from 1 to 3 inches thick, 

interstratifled with blackish-blue, slightly calcareous slate, both containing small specks of silver-white mica, which are more abundant in the 

limestone than in the slate. The limestones hold in abundance fragments 

of trilobites, chiefly belonging to three or four species. Among them is 

Paradoxides (Olenellus) vermonlana, a new species of Bathyurus, and the 

pygidium of a species so closely resembling B. extans of the Birdseyo and 

Black River formation, that it can scarcely be distinguished from it and 

may possibly be the same............................................... 80

2. Grayish green, micaceo-arenaceous shale, interstratified with a few beds of

grayish quartzite weathering slightly yellow............................ 80

3. Strata concealed.......................................................... 30

4. Reddish granular quartzite in thick beds, with numerous parallel joints in

two directions, dividing the beds into rhomboids......................... 105

5. Gray and grayish green, micaceo-arenaceous shale in beds from a quarter of 

an inch to an inch thick, interstratified with a few beds of gray, very ferruginous, sandy dolomite, and fewer of gray quartzite...................

6. Reddish quartzite, in beds of from 1 to 2 feet thick.........................

7. Gray arenaceous dolomite, weathering yellowish brown, iuterstratified with 

reddish quartzite in beds of from 1 inch to 1 foot thick, and with reddish 

and grayish micaceo-areuaceous shale predominating toward the top. The 

beds of dolomite and shale contain fossils, among which are Obolclla cltromalica ?, Obolus labradoricm, Paradoxides vermontana, Conceiihalites, a now 

species of Bathyurus, and one or more undetermined species of Salterella. 27

483 

C.

1. Whitish quartzite in beds of from G inches to 2 feet, interstratified with 

light gray, micaceo-arenaceous shale, in layers of from 6 inches to 1 foot, 

which occur at intervals of from 5 to 10 feet............................. 150

1 Op. cit., pp. 865-807.
256 THE CAMBRIAN. [BULL. 81.

Feet.

2. White and reddish, quartzite, in beds of from 1 to 3 feet thick, interstratified

toward the bottom \vith a gray arenaceous dolomite, weathering yellowish 

brown.................................................................. 100

3. White and reddish quartzite, in beds of from 1 to 3 feet thick, interstratified 

with greenish micaceo-arenaceous shale, constituting about one-half the 

amount................................................................ 90

4. Gray, pure limestone, in beds of from 1 to 3 feet thick, marked with a few 

reticulating strings of yellowish-weathering dolomite. The rock is a mass 

of comminuted organic remains, among which are Paradoxides vermontana, 

and undetermined species of Bathyurus and Salterella, as before......... 20

5. Blackish blue, soft shale, iiiterstratified with gray yellow-weathering limestone, probably magnesian, in beds of 1 or 2 inches thick. The quantities 

of shale and limestone are about equal, and the whole is intersected by 

reticulating strings of calc-spar......................................... 35

6. Gray, pure limestone, composed of comminuted organic remains, belonging

to Paradoxides, Bathyurus, and Salterella, as before..................... 27

7. Bluish black, soft shale, iuterstratified with gray yellow-weathering clolomitic bands, as before.................................... _............. 60

8. Gray, pure limestone, probably composed of comminuted organic remains as 

before; underlaid by bluish black shale, inclosing nodules of blue compact limestone, some of which weather yellowish-brown, and are probably magnesian ........................................................ 13

9. Bluish black, soft shale of the same character as before, interstratified with

a few beds of quartzite................................................. 68

623

Total................................................................. 1,711

I examined the species of Bathyurus referred to in No. 1 of Division 

B, and also some other fossils labeled as coming from Bonne Bay, and 

there can be no doubt that some mistake was made in labeling the 

specimens, for they certainly belong to the Trenton fauna and could 

not have been associated with the Lower Cambrian fauna of the section. All the Paradoxides referred to belong to the genus Olenellus or 

Mesonacis and several of the specimens of Bathyurus to the genus 

Protypus. If the section was correctly measured and the Cambrian 

fossils occur as mentioned all the strata belong to the Lower Cambrian, 

and the fauna is a part of the Georgian fauna of the Cambrian. From 

the accessible data I am not able to discover that the Upper Cambrian 

or Potsdam fauna has been found on the northwest coast of Newfoundland or on the Labrador shore.

SOUTHWESTERN NEWFOUNDLAND.

On the " Map showing the distribution of the Silurian and Carboniferous Formations (etc.) in St. George's and Port au Port Bays, Newfoundland," by Dr. Alexander Murray, 1873-'74, a considerable area is 

designated as Potsdam that is continued north into the valley of the 

Humber. The reason given for the identification of the Potsdam Terraue, in the Eeports of the Geological Survey of Newfoundland for 

1873-'74, '75, is that the strata placed within it are subjacent to the beds 

containing fossils of the Calciferous formation of the Lower Silurian.
WALCOTT.] SUMMARY -NEWFOUNDLAND. 257

This is not sufficient in the absence of Upper Cambrian fossils to establish the presence of the Potsdam horizon on the southwestern side of 

the island. It is quite probable that strata of Cambrian age occur, but 

as yet the proof of their presence is very defective.

EASTERN AND SOUTHEASTERN NEWFOUNDLAND.

The section at Canada Bay is as follows, according to Dr. Alexander 

Murray :* ,

Feet. 

A. Clouds Mountain bluish gray slates, conglomerates, and diorite............ 2, 500

B. Salt Water Pond bluish gray, black, blue, reddish, and white limestones, 

yellowish gray and black slates, and gray and white sandstones, in some 

parts holding Olenelhis vermontanus, Lingnla, Scolithus and fucoids...... 2,000

C. Light and dark blue limestoues and brown slates, with cherty limestone at

the top ................................................................ 900

5,400

The strata referred to the Cambrian system in southeastern Newfoundland are well exposed on the peninsula of Avalou and westward 

along the coast to the northern shore of Fortune Bay, and northward, on 

the western shores of Trinity Bay. Dr. Murray has given a general 

description of the terrane in the reports of the Geological Survey of 

Newfoundland for 1868 and 1870 5 and a fine geological map of the 

Peninsula of Avalon, by Dr. Murray and Mr. James P. Howley, 1881, 

shows the distribution of the Cambrian rocks. The correlated section 

is described as superjacent to pre-Cambrian " Huronian n rocks and as 

having a thickness of nearly 6,000 feet, of which 138 feet are limestone and the remaining portion argillaceous and arenaceous deposits.

The section in descending order is as follows: 2

Feet.

(s) Brown and black micaceous shales, with gray micaceous sandstones of Bell 

Island, Conception Bay. Organic contents are : two species of Lingula, 

four species of Palseopbycus, JSophyton linnceanum (Torrell), and another 

Eophyton, Cruziana semiplicata (Salter) and some others................ 476

(r) Red and green sandstones and slates, with some calcareous beds at the base.

Estimated thickness ... ............................................ 1,426

(g) Kelly's Island sandstones and shales. A few fucoids were the only fossils

observed in this division .............................................. 720

(p) Black slate or shale. At Fortune Harbor this division was found to contain

Paradoxides tennettii .................................................. 150

(0) A bed of dark gray limestone. Fossils consist of broken fragments of

trilobites and shells, among which latter a Lingula was observed....... 5

(TO) Red, green, and black slates, or shales, which occasionally pass into a finely 

laminated argillaceous shale, as at Topsail Head. The fossils are Paradoxides bennettii, Conocephalites gregarius, and probably some other species 

not yet recognized ...................oT............................^.. 1,045

1 Sequence and distribution of the rocks of the great Northern Peninsula. Geol. Survey Now 

foiuulland, Report of progress for 1864. Kevised edition, London, 1881, p. 15.

3 Murray, Alexander: Of Primordial Silurian and Related formations. Hep. Geol. Surv. Newfoundland for 1870, St. John's, 1871, pp. 36-39. Geology of Newfoundland, 1881, London, pp. 237-239.

Bull. 81 17
258 THE CAMBRIAN. [BULL.81.

Feet.

(m) Hard, thick beds of gray and sometimes reddish limestone. Two species 

of Conocephalites have been recognized by Mr. Billings, and a small 

fragment snpposed of Paradoxides from a loose stone at Topsail Head; 

also Salterella and Crania labradorica. Thickness at Topsail Head...... 100

(I) Ked, green, and blackish argillaceous slates. A few remains of trilobites 

were found at Eandom Island, one of which resembles Bathyurua gregarius (Billings) ......................................................... 250

(fc) Conglomerate of Manuel's Brook, not recognized elsewhere ............... 50

(j) Ked and green argillaceous? shales or slates. Thickness at Brigus South

Head................................................................. 150

(i) Red and flesh-colored limestones, in which some obscure fossils have been

found, and an Archseocyathus detected by Mr. Billings.............. 20

(/O Redslate ............................................................... 30

(#) Thin bed of impure red limestone ........... .......................... 10

(/) Red slate................................................................. 40

(e) Red, green, and gray sandstones, with occasional beds of conglomerate. The

upper beds flaggy..................... ............................. 750

(d) Green and reddish brown or purple slates, with smooth and regularly parallel cleavage, independent of the bedding, splitting into slabs under 

half an inch thick. This is the position of the workable slates of Smith's 

Sound and Random Island.................................. ....... 137

(c) Abed of impure flesh-colored limestone .............................. 3

(6) Green slate, same character as d ..= .... ... .,....= .............. 10

 150 

(a) Hard, dark green-gray sandstones with slaty divisions, the sandstone beds

varying in thickness from 4inches to Ifoot.............. ........... 600

Total................................................................. 5,972

On page 160 of the reprint of the report of the Geological Survey of 

Newfoundland for 1868 l a section is given of the strata of Great Bell 

Isle, as follows:

ASCENDING.

Feet

(1) Black or dark brown shales, with thin beds of sandstone from 2 to 6 inches 

thick, of a gray color on fracture, mica being thickly disseminated in both 

shales and sandstones, and especially at the division of the harder members ..................................................................... go

(2) Thin bands of sandstone like the preceding, weathering a rusty brown color,

and divided by layers of black shale..................................... 6

(3) A hard, strong bed of gray sandstone, with conchoidal fracture, irregularly

bedded, average thickness about .......................................: 4

(4) Alternations of black shale and sandstone towards the top of the vertical

cliff ..........o......................................................... 60

(5) A heavy mass of strata, mostly sandstone, forms the crest of the cliff........ 10

(6) Alternations of very micaceous gray sandstone and shale, the former mostly 

thin-bedded, varying from 1 to 6 or 8 inches, with Cruziana iu great profusion on many surfaces. Nodular concretions, holding Lingulse among the 

shales ................... ................................................ 100

(7) The upper strata are a good deal concealed, but beds of sandstone occasionally crop out on the bed and banks of a small brook near the line of section, 

some of which is of a pale yellowish color, in some cases nearly a foot thick, 

estimated........................................... ................ 196

'Murray, Alex.: Of the sequence and distribution of the formations. Report upon the geological 

survey of Newfoundland for 1868. St. John's, 1868. Bevised edition, 1881.
WALCOTT.] SUMMAKY NEWFOUNDLAND. 259

Feet.

(8) The upper stratum is also in great part concealed, but large, angular-jointed 

fragments of it are abundant on the surface all along the summit level, 

which are clearly in place, or only slightly removed. Some of these beds 

appear to be from 1 to 2 feet thick, are rather coarsely granular, of a grayish 

or greenish color on fracture, and contain crowds of organic remains, chiefly 

a species of Lingula. Estimated...................-.........'............ 80

Total................................................................. 476

In No. 2 of this section I found, in 1888, a small species of Lingula (*?), 

abundant remains of Gruziaua, and an entire specimen of Olenus. Numerous trails of annelids occur on the surfaces of the sandstones, from 

one to six, inclusive.

Mr. E. Billings described the fossils obtained by the Newfoundland 

survey from Great Bell Island and named Eopliyton julcesi, Arthraria 

antiquata, Lingula murrayi, Lingulella ? affinis, L. f spissa, arid Gruziana, similis.1

In the upper portion of No. 6 Lingula murrayi occurs in considerable 

abundance, and from No. 8 a large number of specimens of Lingula 

spissa were collected; Eopliyton linnceanum Torrell and Arthraria antiquata occur in Nos. 2 and 4.

There is no detailed section given of the strata of Little Bell Island. 

The section, as determined by the writer in 1888, is made up of dark 

argillaceous and sandy shale, with beds of gray and dark sandstone, 

both thin-bedded and in massive layers. In the argillaceous shales 

Lingida billingsiana is very abundant and ranges through about 150 feet 

of strata. Toward the summit of the section on the west shore of the 

island a species of Hyolithes, and a long, slender shell, that may be 

provisionally referred to Lingulella, occurs in a light gray sandstone. 

A few feet below this horizon a new species of Lingula was found in a 

micaceous sandstone associated with the Lingula "I occurring below in 

the shales.

All the strata of Little Bell Island have a dip of about 7° westward 

toward Great Bell Island. If this dip be retained and the section be 

unbroken, the higher beds would pass beneath the strata on Great Bell 

Island, at a depth of about 1,200 feet. Dr. Murray in the generalized 

section mentioned, has given a thickness of 1,426 feet for the strata of 

Little Bell Island and that concealed beneath the waters of Conception Bay before reaching Great Bell Island.

A detailed section of the strata of Kelly's Island of what appears to 

be the same series as on Little Bell Island is published by Dr. Murray.2 

A small Lingula (L. lillingsonia) was found midway of the 713 feet of 

strata. I found the same species to be very abundant in the shales of 

tbe lower portion of the Little Bell Island section.

1 On some fossils from the Primordial rocks of Newfoundland. Canadian Naturalist, new ser., vol. 

6, 1872, pp. 405-479.

* Of the sequence and distribution of the formations. Report upon the geological survey of Newfoundland for 1868. St. John'8,1868; revised edition, 1881,pp. 157-159.
260 THE CAMBRIAN. [BULL.81.

The section on the mainland beneath Topsail Head, Conception Bay, 

was found to be as described by Dr. Murray.1 The limestone at the base 

is separated from the "Huronian " rocks by a fault line. Over the limestone 100 feet or more of greenish shale completes the section. In the 

limestones were found : 2

Obolella atlantica. Microdiscus speciosus.

Kutorgina labradorica. Microdiscus, sp. undet.

Scenella reticulata. Olenellus (H. )brb'ggeri.

Hyolithellus micans. Avalonia manuelensie.

H. micans var. rugosa. Solenopleura bombifrons.

Hyolithes princeps. Agraulos (S.) strenuus.

iinpar. Agraulos (S.) sp. ?

In the superjacent green shales a few fragments of a trilobite were 

observed that indicated by a portion of the glabella and eye-lobe a 

large species of Paradoxides. The evidence here obtained of the relation of the Olenellus and Paradoxides faunas being somewhat inconclusive, the section at Brigus Head, on the west side of Conception Bay, 

was next examined and found to be essentially the same as that at Topsail Head, with the addition of a greater thickness of green and red 

shales above the limestone, and a sandy deposit beneath the limestone 

which rested unconformably against the "Huronian." The limestone 

series is divided into three bands. In the lowest, a specimen of Hyolithes impar was found, similar to that in the limestone at Topsail Head, 

associated with fragments of Olenellus (H.) broggeri, Microdiscus lielena 

and Ptychoparia ? sp. (?). In the second bed of limestone, fragments of 

trilobites were seen; and in the upper bed Olenellus (H.) brb'ggeri and 

Agraulos strenuus were observed, the latter in great abundance. No 

fossils were discovered in the superjacent slates.

The stratigraphic succession on ManueFs Brook, as measured by me 

in August, 1888, is as follows :3

MANUEL'S BROOK SECTION.

Feot.

(1) Coarse conglomerate, in massive layers. The material next to the gneiss 

varies in size from bowlders of quartz and gneiss 6 feet in diameter 

down to small pebbles, and in the upper beds from pebbles to fine sand. 35 

Strike N. 80° E. (Magnetic); dip 12° to 13° N.

(2) Irregular beds of calcareous sandstone, siliceous limestone, and greenishcolored argillaceous shale, covering the irregular upper surface of the 

conglomerate ....................................................... 0 to 25

Fossils: Ololella dtlantica, Hyolithellws micans, Helenia tella, Hyolitlies princeps, H. impar, H. quadricostatus, H. similis, H. terranovicus, 

Scenella reticulata, Stenotheca rugo8a,^aii&tienacuta-costa,erecta, Iccvisand. 

pauper, Platyceras primcevum, Microdiscus lielena, M. speciosus, Olenellus 

(H.) broggeri, tAvalonia manuelensis, Agraulos (S.) strenuus and var. nasutus, Solenopleura lombifrons, S. harveyi and S. howleyi.

1 Op. cit., p. 154.

2 Walcott, C. D: Stratigraphic position of the Olonellas fauna in North America and Europe. Am. 

J our. Sci, 3d ser., vol. 37,1889, p. 378.

3 Op. oit, pp. 380, 381.
WALCOTT.] SUMMARY NEWFOUNDLAND. 261

Feot.

(3) Greenish argillaceous shale, conformably subjacent to 2 ................ 40

(4) Reddish-colored argillaceous shale ..................................... 4

(5) Calcareous sandstone, with pinkish limestone in irregular masses........ 2

(G) Green argillaceous shale with thin layers of hard, dark, ferruginous sand1 stone, interbedded at several horizons ............................... 270

Strike N. 80° E.; dip 12° N.

Fossils: Near the base the head of an Olenellus was found; also fragments of an Agraulos or Ptycho paria. At 218 feet from the base a 

layer of pinkish limestone contained the head of an Agraulos, like A. 

strenuus, and many fragments of trilobites. Fifty-two feet higher up 

quite an abu'ndaut fauna was found, and the following species were 

collected: Lingulella sp. a., Acrothelemaltlieivi, Agnostus sp. a., Agnostus 

sp.d., Paradoxides Mcksi, Conocoryphe mattheivi, and Liostracus sp. a.

(7) Dark argillaceous shales with thin layers of limestone and sandstone at

various horizons .................................................... 295

Fossils: Zone A: From 10 to 20 feet from the base the following species were collected: Lingulella sp. a, Linnarssonia misera, Acrothele 

matthewi, Hyolithes sp. a, Agnostus 3 sp. a, 1), c, Microdiscus punctatus, 

Paradoxides hiclcsi, Conocoryphe (C.) mattheivi, C.elegan8,Agraulo8sociaUs, 

 and Liostracus tener.

ZoneB: Forty-five feet higher the fauna is much larger and includes: 

Linnarssonia misera, Lingulella sp. a, Orthis sp. ?, Slenotheca sp. ? , Agnostu8 pwictiiosus, Agnostus 5 sp. b, e, f, g, h, Microdiscuspunctatus, Paradoxides davidis, P.hicksi, Paradoxides, sp., Anopolenus venustus, Conocoryphe 

elegans, Ctenocephalus matthewi, Erinnys renulosa, Ptychoparia robbi, P. 

variolaris, Holocephalina inflata and Agraulos socialis.

From 235 to °250 feet from the base a belt occurs in which a small 

species of Aristozoa occurs in large numbers, associated with Lingulella 

sp.a, Agnostus sp. ?, and the heads of a small Ptychoparia? sp. undot.

(8) Alternating bands of dark shale and dark, compact sandstone that carry

a small species of Orthis in large numbers................r........... 400

The section is here cut off by the shore of Conception Bay.

The fauna of No. 2 is essentially the same as that of the limestones 

of the Topsail Head and Brigus sections, and proved conclusively that 

the Olenellus fauna is subjacent to the Paradoxides fauna.

Beneath the conglomerate beds of Manuel's Brook and between them 

and the subjacent Archean gneiss, there is, according to Messrs. Murray and Howley, a series of red and green sandstones, conglomerates 

and massive sandstone strata, which, according to their tabulated section, have a thickness of 1,800 feet. They are exposed on the north 

side of Trinity Bay and partially on St. Mary's Bay. I think we should 

have more data before deciding that this series of 1,800 feet is really 

subjacent to the Manuel's Brook conglomerate; although it is extremely 

probable that such is the case, judging from the character of the Trinity Bay and Conception Bay sections.

On the islands in the bay the Upper Cambrian horizon is well developed. In the lower arenaceous shales at Lance Cove, on Great Bell Island, were found Eopliyton sp. ?, Cruziana semiplicata, Arthraria antiguata, Olenus sp. undet., and at a higher horizon, near the center of the 

island, Lingulepis ajfinis and Lingula ? murrayi, with fragments of Cru-
262 THE CAMBRIAN. IBULL.SL

ziana. In the sandstone at the summit of Little Bell Island, 20 feet 

above a band of sandstone carrying languid, ? billingsiana and an elongate, narrow species of Lingulella, a long slender Hyolithes"? and a broad 

species of Hyolithes occur. In the dark argillaceous shales beneath 

L. f billingsiana occurs in great numbers.

The conglomerate (No. 1 of the section) was traced, just north of the 

outcrop of the gneiss, a mile to the west of Manuel's Brook1, and the 

shales and limestone of No. 2 were seen in a number of sections, resting directly upon it. On the brook the stratigraphic succession is unbroken up to the summit of No. 8, and the strata are conformable and 

undisturbed with the exception of the dip of 12° to the north.

The Manuel's Brook section is the only one known to me on the 

North. American continent where the typical Olenellns and Paradoxides 

faunas occur in an unbroken stratigraphic section. The Olenellus 

fauna is well developed and typical, and the same is true of the Paradoxides fauna.

As shown on the Avalon Peninsula the early Cambrian Sea transgressed 

across all the pre-Cambrian rocks, includingthe Aspidellaslates and Signal Hill sandstone and the great series of altered slates and sandstones 

and, subjacent to them, the Laurentian gneisses. This unconformity is 

of a similar type to that between the Algonkian formations of the Lake 

Superior and Adirondack regions and the Upper Cambrian sandstone. 

In each, three groups of rocks have been deposited and subsequently 

elevated by an orographic movement and eroded before the deposition 

of the Cambrian sediments. The relations of the Cambrian and preCambrian rocks are all well shown upon the geological map of the 

peninsula of Avalon, Newfoundland, 1881, prepared by Mr. James Ps 

Howley.

NOVA SCOTIA,

It is very probable that the Cambrian group is represented in the 

gold-bearing slates of the Nova Scotia section, but as yet the only 

means of correlation is the supposed stratigraphic position. The principal details and arguments for including this series in the Cambrian 

have already been given under the historical review. (Ante, pp. 56-59.) 

It may be that they represent in large part a pre-Cambrian, Algonkian 

group equivalent to the St. John slates of Newfoundland.

NEW BRUNSWICK AND CAPE BRETON.

Our present knowledge of the Cambrian geology of the area under 

consideration is obtained from the reports of the Geological Survey of 

Canada, and the numerous papers on the geology and paleontology of 

southern New Brunswick by Mr. G. F. Matthew.

In the report of the Geological Survey of Canada for 1870-'71, a detailed description is given of the geographic distribution of the St. 

John group (pp. 134-143); and other details are aelded in the report 

for 1878«'79 (pp. 6D-SD). From these reports and the map accompany-
WAWOTT.J SUMMARY NEW BRUNSWICK. 263

ing the latter, Mr. G. F. Matthew has compiled a summary of the information relating to the St. John terrane. He says: 1

The strata of the St. John group fill a number of narrow, trough-like basons, lying 

between the Bay of Fuudy and the central carboniferous area of New Brunswick. 

Of these basins, that on which the city of St. John is situated is the most important, 

and it is here also that the life of the period can be studied to the best advantage. 

The St. John basin lies diagonally across the ridges of Huronian rock that are found 

in the eastern part of St. John County and touches the ridge of Laurentian rocks 

that divides this county from King's, As'might naturally be expected, the coarser 

sediments found at the base of the St. John group are largely derived from those 

older rocks, chiefly the Huronian; and the line of division between it (the St. John 

group) and the Huronian formation is marked by conglomerates of mechanical origin 

which show no trace of the hardening process by which the Huronian conglomerates 

and breccias have been so firmly cemented.

The Conglomerates of the St. John group are most fully developed in the eastern 

part of the St. John Basin, under the lee of the high ranges of Huronian hills which 

exist in that direction. In Portland and the city of St. John, at the western end of 

the basin, the following section represents the succession of members in this group 

in ascending order:

Foot. 

Division 0:

(a) Red Conglomerate wanting at that part of the basin where this section was made ..............................................!.....

(6) Red and green sandy slates.....................o...................o 150

Division 1:

(a) Coarse gray sandstone or quartzite ............ ...=.............. . .<, 50

(6) Coarse gray sandy slate (Linguloid sheUs)............................ 50

(o) Fine gray and dark gray slaty shales (Trilobites, etc.)............... 25

(d) Fine black carbonaceous slaty shales (Trilobites, etc.)................ 75

Division 2:

(a) Dark gray slates with thin seams of gray sandstone .........I......... 220

(&) Coarse gray slates and gray flagstones ............................... 200

(c) Gray sandstones and coarse slates (Liuguloid shells).................. 130

Division 3:

(a) Dark gray finely laminated elates.................................... 450

(1)) Black carbonaceous and dark gray slates, less fissile than the last..... 300

Division 4:

Slates and 'flags, resembling 2a and 26 (Linguloid shells).................. 800

Division 5:

Black carbonaceous slate like,36 (Orthids,Trilobites, etc.).... ........... 450

2,900

Beyond Division 5 the beds are supposed to be repeated by an overturn, and have a 

width across nearly vertical measures of 3,000 feet. Owing to this folding of the 

measures there is some uncertainty as to where the summit of the formation is, and 

the section given may not include the whole series of deposits. The faunas of Divisions 2 and 5 are very imperfectly known, but there are much larger species of Linguloid shells in these divisions than in Division 1, and the orthids of Division 5 are 

different from OrtMs billing ai of Division 1.

The Conglomerate at the base of the St. John group marks the time when the sea of 

the Acadian epoch invaded the valleys of the Huronian formation near St. John. No 

trace of life has yet been found in these coarse sediments, nor in the red and greon

1 Illustrations of the fauna of the St. John group. Royal Soc. Canada, Proc. and Iran8., vol. 1, section 4,1883, pp. 87-108. Supplementary section, pp. 271-270. 
264 THE CAMBRIAN. IBULL. 81.

slates into which they pass. After the colored mud of which these slates are composed was deposited, an abrupt change took place in the character of the deposit, and 

white sands were evenly spread over the whole basin. It is in the upper part of these 

sands that one meets with the earliest traces of primordial life. These first forms are 

linguloid shells of several genera. Such shells become more abundant in the upper 

part of the white and gray sandy beds, and were evidently littoral species, as on 

tracing the sandstones westward for half a mile they are found to change into a gray 

slaty and pebbly deposit evidently an old beach line and finally.disappear.

Probably the physical condition of the St. John Basin at this early period was unfavorable to the growth of the trilobites; but the land was sinking, and an additional 

depth of water in this sheltered area soon encouraged the growth and multiplication 

of the crustacean fauna. As the sediment which settled from the sea water in this 

deepening bay became finer, the remains of marine animals were preserved in greater 

numbers and variety, so that in the layers of fine slate in Group c of Division 1, many 

genera chacteristic of the early Cambrian age are found.

In Group d the slaty mass becomes quite fine and dark colored, but near St. John 

is much, affected by slaty cleavage, and the fossils are so much distorted, especially 

in the upper part, as to be unrecognizable.

In the beds of Division 2, a return of littoral conditions, and the influx of sand, 

interfered with the prosperity of the crustacean fauna, and as in the lower sand beds 

of Division 1, linguloid shells become the prevailing fossils. The Paradoxides which I 

will describe in this article are those of the intermediate mud beds, now converted 

into a mass of slaty rock (Division 1, c). 1

On the evidence of the contained fauna, Mr. Matthew correlated the 

fauna of the Paradoxides zone of the St. John group with that of the 

Solva group of Wales, as defined by Dr. Hicks.2

In addition to the section as found at St. John there is to be added a 

series described by Mr. Matthew, occurring below Division 1, on Hanford 

Brook, in the eastern part of St. John County. In the report upon 

the geology of southern New Brunswick, by L. W. Bailey, in 1865, this 

mass of sediments was spoken of as the upper member of the Coldbrook 

group and distinct from the St. John group; it was subsequently joined 

to the St. John group by Messrs. Bailey and Matthew in a report of 

progress of the geological survey of Canada, 1870-'71, p. 59, because the 

want of conformity existing between the two formations could not then 

be established; but it is now found that this series is uuconformable 

not only to the St. John group, but also, as had been previously discovered, to the underlying Coldbrook group.3 The section is as follows :4

Thickness 

in feet.

1 (a) Coarse purplish red Conglomerate, resting on an amygdaloidal greenstone

(toadstone) of the Coldbrook group.................................. 60

(ft) Gray and purplish flags and sandstones with worm-casts, seaweeds

(Palaeochorda and Buthotrepbis), and numerous spicules of sponges... 70

(c) Purplish red sandstones, with greenish layers. Remains of seaweeds 

(Phycoidella), animal tracks (Psamrnnichnites and Helminthites), 

worm-burrows (Arenicolites) etc..................................... 240

1 Op. cit., pp. 87-89.

s The geologic age of the Acadian fauna. The Primitive Conoooryphean. British Assoo. Rep.,54th 

.meeting, 1884, pp. 742-744.

8 On a basai series of Cambrian rocks in Acadia. Canadian Record Science, vol. 3,1888, p. 22. 

4 On Cambrian Organisms in Acadia. Eoyal Soc. Canada, Trails., vol. 7, Proc., sec. 4,1890, p. 138.
WALCOTT.J SUMMARY NEW BRUNSWICK. 2G5

Thickness 

in feet.

2 (a) Purplish red Conglomerate, more friable than 1 a. ............ .......... 35

' (fc) Soft purplish red shales, with green glauconito grains, the upper part 

firmer and more sandy, greenish gray layers interspersed especially 

towards the base. Platysolenites, Obolus, Volborthella, etc .......... 175

(c) Purplish sandy shales, with a few bands of greenish shale. Worm-casts

(Scolites) ........................................................... 300

Measures concealed, probably of this series............................. 320

1,200

In this series of 1,000 or more feet of beds, the very oldest layers which are fine 

enough to preserve organic markings, have trails and casts of marine worms, and 

also contain seaweeds, one a Palajochorda or allied genus, the other a weed with a 

flat frond similar to Buthotrephis. That these beds are marine is clearly shown by 

the great numbers of spicules of hexactinellid sponges which they contain.

About 350 feet above the base, where the measures are flaggy, tracks of annelids 

are again abundant. Besides the smaller trails and burrows, there are frequent 

tracks of a marine animal, possibly a worm, similar to the markiues on the Fucoidal 

sandstone of Sweden, which, by Prof. 0. Torrell, have been referred to the geuus 

Psaiuniichnites. A very similar track, with corresponding casts, occurs on the surfaces of the purple streaked sandstones (Assise 3) of Band 6 in Division 1, of the Sfc. 

John group, and a similar trail occurs as high up as the lower band of Division 2 of 

that group. Above this point, such markings have not been found, though the kind 

of rock flags and slates is favorable to their occurrence. The flags of the middle of 

Division 2, of the St. John group, seem to be the horizon of Cruziana aemiplicata 

(Salter) and C. similia (Billings); but I have not found them here.

About 100 feet or more above the horizon where Psammichuifces appears, separated 

from it by a Conglomerate, indications of the Olenellus fauna show themselves. 

These consist of Volborthella (a chambered coll resembling an Orthoceras), the cystideau genus Platysolenites, Pander, and a large Obolus, allied to Michwitzia (formerly 

Obolus? or Lingula?*) monilifera, Linrs., of the Eophyton sandstone of Sweden and 

the upper part of the " Blue Clay " of Russia. Some of the layers in this part of the 

series abound in soft green grains similar to the glauconite grains of the Cambrian 

rocks in Russia. The paste enveloping them is red.

A number of beds between this point and the top of the Basal series contain wormcasts and burrows, and some have remains of small strap-like seaweeds.

In summing up the facts bearing on the comparative age of this part 

of the Cambrian rocks in Acadiawe get no aid from the typical genera 

of this horizon, Olenellus and Mesonacis, but the Acadian rocks contain other genera of this fauna which serve to fix their age with a certain degree of accuracy. Some of these genera, however, are such as 

may have a wider range of existence in time than the trilobites, and 

therefore are not of the same homotaxial value. The trilobites that do 

occur are not so definitive as some others.1

In his latest table of classification Mr. Matthew arranges the Cambrian System, as it occurs in Acadia as follows :2

Localities. 

D. Upper Cambrian (Potsdam series) ..................Unknown.

C. Middle and Lower Cambrian, Acadian series.. ....St. John, etc.

B. Lower Cambrian, Georgian series.................... C. Breton.

A. Basal Cambrian, Etcheminian series ......... ....St. John, etc.

'Op. cit.,p.!43.

2 On the classification of the Cambrian rocks in Acadia. No. 2. Canadian Kecprd'of Science, vol. 3, 

1889, p. 310.
266 THE CAMBRIAN. IBULL.SI.

In describing in 1888 (at that time called series B) the Paradoxides 

zone, or C of the preceding tabulation, the term " stage " replaces the 

word " division " as heretofore used by Mr. Matthew, and the divisions 

of the series are given as follows :* ,

Stage 1. This includes the lower part of the series as high up as Paradoxides are

found. The divisions of this stage are as follows : 

Band (assise) a. Hard gray sandstone or quartzite. Fossils, none known. 

Band (or assise) &. Dark-gray sandstones and gray sandy shales. Fossils:

Ellipsocephalus, Agraulos, Hipponicharion, Beyrichoua, etc. > Band (or assise) c. Gray shales. Fossils: Paradoxides, Conocoryphe, Liostracus, Microdiscus, Agnostus, etc.

Band (or assise) d. Dark gray shales. Fossils: Paradoxides, Ptychoparia, 

Soleuopleura, Microxliscus, Agnostus, etc., of different species from those 

in assise c.

Stage 2. This consists of gray flags and sandy shales. The subdivisions have not 

been worked out, hut the stage corresponds to the lower half of the Olenus 

zone in Europe. No species of the genus Olenus have heen found in it. 

Stage 3. Dark-gray and black shales. Fossils: Ctenopyge, Kntorgiua, Orthis, etc. 

This corresponds to,the upper half of the Olenus zone of Europe. The 

shales in Cape Breton, which contain Peltura and Sphseropthaluius, belong here. There are in the St. John Basin gray flags, which overlie the 

Ctenopyge beds, but no higher stage than the Olenus zone has heen established by fossils.2

In a series of sections of Cambrian rocks in Acadia,3 the upper Cambrian or Oleuus beds are shown to be present in St. John County in the 

Portland section.

Just as this report is going to press (May 1, 1891) 1 received the fifth 

contribution of Mr. G. F. Matthew upon the fauna of the St. John 

Group. In the introduction he gives a description of the structure of 

the St. John basin and sections of the measures at St.John. He finds 

that all three of his divisions of the Cambrian are present. Division 1 

he names Acadian, Division 2 Johannian, and Division 3 Bretonian.4

The Cambrian rocks of. Cape Breton Island are described with many 

details by Mr. Hugh Fletcher in 1877 and 1878, but the various outcrops 

do not appear to have been well correlated. The section in McLean 

Brook, on Little Bras d'Or Lake, is as follows: 5

Feet

(1) Carboniferous conglomerate and related rocks..............................

(2) Feldspafchic sandstone and impure limestone, of white, green, amber, red, 

and other colors, mixed, and in distinct beds of different thickness; sometimes associated with greenish, soft, soapy rocks, probably decomposed felsites; films of hematite in the joints................................... 254

1 On the classification of the Camhrian roots of Acadia. Canadian Rec. Sci., vol. 8,1888, p. 73.

2 Mr. Matthew writes me under date of October 25,1890, that he has found the Areuig graptolitic 

fauna in the St. John series, thus establishing the presence of the Lower Silurian (Ordovician) fauna 

above the Olenus zone.

3 Matthew, G. P. On the classification of the Cambrian rocks in Acadia. No. 2. Canadian Rec. Sci., 

vol. 3,1889, p. 308.

4 Illustrations of the fauna of the St. John Group, No. 5. Royal Soc. of Canada, Trans., vol. 8,1891, 

p. 129.

6 Report on the geology of part of the counties of Victoria, Cape Breton, and Richmond, Nova Scotia. Geol. Sur. Canad. Rept. Prog, for 1876-77. Montreal, 1878, p. 431.
WALCOTT.] SUMMARY MAINE. 267

Feet.

(3) Blackish and gray slate, Qne sandstone, and argillaceous limestone; also, 

compact, feldspathic rock, mixed with limestone of different colors. Not 

well seen........._................._...._ ............................. 84

(4) Dark and pale gray slates, with thin layers of quartz, spotted -with iron

pyrites and mined for gold ............................................ 6G

(5) Greenish gray, fine-grained, pyrifcous rock, resembling sandstone and yielding easily to the knife................................................. 19

(6) Black and gray argillite, full of small twisted layers of quartz, which are 

sometimes so numerous as to constitute an impure qnartzite, spotted \vith 

pyrites. Associated with and overlie dark-blue, plumbaginous argillite, 

also full of pyritons quartz layers.......................... ............ 65

(7) Bluish-gray, pearly, papery slates, cleft in every direction and traversed in

the bedding and acrossjt by streaks of calcspar and quartz ............ 30

(8) Bluish felsite, crystalline limestone and quartz, confusedly mixed in contorted beds ...................................................a....... 37

(9) Bluish-gray coherent argillite............................................ 60

(10) Greenish,decomposed, feldspathic rock, of uncertain thickness .......... 110

(11) Bed syenite in steeply rising hills.........0 .... _.......................

725

The Cambrian rocks occur as long narrow areas resting on the subjacent Laurentian rocks, as shown on the map accompanying Mr. Fletcher's 

report of 1876-'77; and on the map accompanying the report for 1875-'7G. 

In the text of the latter report the rocks are described as they occur on 

St. Andrew's Channel, and the geographic distribution is given on the 

map. From a small outcrop on the Mira River a collection of trilobites was obtained that indicate the upper Cambrian fauna. They include, as identified by Mr. Matthew, Peltura scarabeoides, SpkcerophtJialtnus alatus, and Agnostuspisiformis.1 It is not certain that all the rocks 

referred to the Lower Silurian by Mr. Fletcher belong to the Cambrian 

group, but as far as known all the fossils that have been found indicate 

the upper Cambrian series.

MAINE.

The presence of typical rocks of the Cambrian group in the State 

of Maine is not yet proved. It is quite probable, as in the case of Nova 

Scotia, that the series of slates referred to the Cambrian actually belong 

at that horizon. But until paleontologic evidence is obtained, the 

question will be an open one. The strati graphic position of the slates 

and their lithologic character enable us to speak of them tentatively 

as belonging to the Cambrian group. That they were deposited in the 

same basin as the Cambrian series of New Brunswick and Massachusetts is not probable.

NEW HAMPSHIRE.

All the references of strata to the Cambrian group in New Hampshire 

are of a provisional character. They are based upon more or less im1 On the Cambrian faunas of Cape Breton and Newfoundland. Royal Soc. Canada, Proc. and Traus. 

vol. 4, sec. 4, 1887, p. 147.
268 THE CAMBRIAN. [BULL. 81.

perfectly determined stratigraphic horizons and the fact that there is 

a thick mass of sediments, usually without fossils and largely argillaceous in character, that appear to be pre-Silurian in age. By their lithologic character they are correlated with formations referred to the 

Cambrian group, as found in Maine and Nova Scotia, that have similar 

lithologic characters and occur in a similar stratigraphic position. All 

these doubtful formations are in turn correlated by their lithologic characters and supposed stratigraphic position with the Cambrian beds of 

Newfoundland and New Brunswick.

In speaking of the Mica-schist series of New Hampshire, Prof. C. H. 

Hitchcock says * that there unquestionably exists an enormous thickness of mica-schists in southern New Hampshire above the Huronian 

series. "No author who has devoted any attention to these groups has 

suggested an inferior position for them. They may be called Silurian, 

Cambrian, or pre-Cambrian, according as each author is inclined to regard New England, very ancient, or on the verge of the Paleozoic."

It is doubtful if these exposures should be referred to the Atlantic 

Coast Province. It is done at present as a matter of convenience.

EASTERN MASSACHUSETTS.

The description of the Cambrian rocks of the Boston Basin, by Prof.W. 

O. Crosby, is the most recent and the most thorough of any we have, 

and the summary of our present knowledge of them is taken mainly 

from his paper. He says: 2

The oldest rocks whieh we have found are the Primordial slates and quartzites, 

and the age of these is certainly and definitely known only at the Paradoxides quarry, 

in Braintree. We appear to be justified, however, in regarding them, provisionally 

at least as all of about the same age, partly on account of a general lithologic resemblance, but mainly because their relations to the different classes of eruptive 

rocks are everywhere the same. In Weymouth and Braintree, where we first met 

these rocks, they are either typical clay slates or slightly calcareous ; but along the 

northern base of the Blue Hills occasional layers are distinctly siliceous. They probably underlie a large part of the Boston Basin, being covered by the conglomerate 

and the newer slate; and north of the basin, as shown in the ninth lecture, they 

occur in isolated areas among the eruptive rocks. In some of these areas, especially 

in the Middlesex Fells and Melrose, and in Woburn, clay slate similar to that in 

Quincy and Braintree is repeatedly interstratined with quartzite, while toward the 

southwest, in Natick, and also in Reading andLynnfield, there are extensive developments of quartzite with little or no slate. It is very clear that the quartzite north 

and west of the Boston Basin is the source of the quartzite pebbles which play such 

a prominent part in the composition of the conglomerate, especially in the central 

and northwestern sections of the basin. In general, the quartzite is more and the 

slate less abundant northwestward, indicating that the ancient shore line along 

which these strata were deposited lay in that direction, and originally the Primordial 

strata were probably spread continuously over all the region to the southeast of 

that line.

1 Geological sections across Vermont and New Hampshire. Am. Mus. Nat. Hist. Bull., vol. 1,1884, p. 

168. 

'Physical History of the Boston Basin. Lowell free lectures, 1889-1890. Boston, 1889, pp. 19,20.
WALCOTT.J SUMMARY MASSACHUSETTS. 269

The deposition of tho Primordial strata was followed by a period of disturbance of 

this part of the earth's crust, during which they were strongly compressed, being 

thrown into sharp folds having, in general, a northeast and southwest direction. This 

appears, also, to have been a period of intense volcanic activity. The quartzite and 

slate were shattered and isolated by great volumes of basic lava, which we now caU 

diorite; and, as indicated by the compact and scoriaceous cliorite of the Middlesex 

Fells and other localities, immense floods of lava were also poured out on tho surface, 

concealing the sedimentary rocks. In breaking through the quartzite and slate, the 

diorite has often followed the plaues of stratification in those rocks, and thus appears 

in many cases to be regularly interstratifled with them; and this bedded appearance 

of the diorite is greatly increased by the very perfect flow-structure which was developed in large masses of it, as well as by the distinctly schistose or foliated structure sometimes resulting from the subsequent action of both mechanical and chemical 

forces. We are thus able to explain the fact that the diorite has been frequently 

mistaken for a stratified or sedimentary rock.

The eruption of the diorite was probably followed by a prolonged period of quiet 

erosion, which was finally terminated by the advent of a second period of intense 

and long continued igneous action, during which only acid rocks the granites and 

felsites were formed. All over this region the granite has brokBn through the Primordial strata and the diorite in the most irregular and intimate manner.

Prof. Crosby considers that after the deposition of the argillites and 

the eruption of the rocks occurring as dikes the series was raised above 

the sea level and subjected to long-continued erosion, prior to a downward movement or subsidence. As the surface passed slowly below 

the level of the sea a thick bed of conglomerate was spread over the 

earlier series of rocks and a fine silt or clay carried out into the deep 

water of the ocean. At the same time eruptive rocks were repeatedly 

poured out over the sea floor, where the beds of gravel and sand were 

accumulating, thus forming alternating beds of conglomerate and sandstone with beds of melaphyr and porphyrite. x

Of the subsequent depositions of sediment, he says:

Alternations of the conglomerate with beds of both sandstone and slate are also of 

common occurrence, indicating oscillations of level during this period. But the downward movement prevailed, until finally the water became too deep and quiet and 

too remote from the shore, in this vicinity, to permit the formation of conglomerate 

and sandstone; but these coarse sediments were gradually replaced by slate during 

the dying out of the volcanic activity. These tranquil, deep-sea conditions must 

have continued for a very long time, for the argillaceous sediments accumulate very 

slowly and yet the slate series has a thickness of from 500 feet to fully 1,000 feet or 

more.' The slates are probably somewhat thicker than the conglomerates, and were 

doubtless several if not many times longer in forming. Of the life existing in the sea 

at this time we unfortunately know but little, as the slate is very generally destitute 

of fossils; and the full chronologic significance of the few organic remains that have 

been obtained from-the layers of limestone in the slate at Nahant is still undetermined. 3

There is evidently an error in Prof. Crosby's interpretation of the 

stratigraphic succession of the formations he describes, as the fauna at 

Nahant is of an older date than that found in the argillites at Braintree. 

If, however, the conglomerates, with their contemporaneous eruptive

1 Op. oit., p. 20. B 0p. cit, p. 21.
270 THE CAMBRIAN. [BULL. 81.

rocks, belong to the same series as the Bast Point slate and limestone 

the entire series must be referred to the Cambrian.1

In his report of 1880 Prof. Crosby considers that the strata of the 

Boston Basin were deposited in a depression excavated in the crystalline formations and that there are several formations belonging to the 

Cambrian. First, a conglomerate, represented by the Roxbury puddingstone. Second, a slate series which incloses the Paradoxides zone in 

South Braintree. He assigns to the conglomerate a maximum volume 

not exceeding 1,000 feet, and considers that the greatest thickness of 

the slate can not be much less than that of the conglomerate, although 

in some cases certainly falling below 500 feet.2 At thetrilobite quarry 

in Braiutree, the known locality of Primordial fossils, the slate is described as of a greenish gray color, " somewhat siliceous, fine-grained, 

and remarkably uniform. Minute grains of pyrite are pretty generally 

diffused. In the quarry the rock is apparently only very coarsely 

jointed; but the weathered surface reveals much finer division by this 

means. The stratification is very massive and can hardly be detected, 

except by means of the trilobite remains; these may be supposed to 

lie in the plane of the bedding, and according to this indication the 

strike is E.-W., and the dip S. 80°-85°. Across the strike, southerly, 

the slate, still apparently maintaining a high dip in tbat direction, is 

met at a distance of perhaps 300 feet by fine-grained grayish and reddish Huronian granite, while on the west the same granite cuts off the 

slate at about twice the above distance from the trilobite quarry; that 

is, the contact of the two formations, as shown on the map, is oblique 

to the strike of the slate." 3 On the map the slate series throughout 

the Boston Basin is correlated with the slates at Braintree, and represented by a common color.

'In a letter received from Prof. Crosby, dated January 27,1891, he says: "The Nahaut slate is 

entirely isolated, and concerning its relations to the conglomerate we know nothing. I have supposed, 

however, that it should be referred to the newer series, above the conglomerate." Of the general 

geology of the Boston Basin he says :

"Assuming that the slates of the Boston Basiu now known to be Cambrian are overlain in succession by the conglomerates and a newer slate series (my present working hypothesis), it is still possible, I suppose, that all these rocks, in the Boston Basin, may be Cambriau; notwithstanding the. 

marted uniformity between the conglomerate and lower slates.

" The weak points in the stratigraphy are (1) the general (not entire) absence of slate pebbles in the 

conglomerate; (2) the absence of clear sections showing the conglomerate resting upon a lower slate 

series. Wherever the base of the conglomerate is seen, it reposes upon tins granite oifdsite. Some 

of the sections are very clear and unmistakable in this respect; and apparently the same granite and 

felsiteare eruptive through the Braiutree slates. It would, of course,be dillicult toprooc that tho 

granites and felsites are all of the same age; but it seems best to assume that uutilthe contrary clearly 

appears.

" The best general statement of the stratigraphy of this region appears therefore to be this: A 

lower slate, known to be Cambrian ; cut in succession by diorite, granite and felaite; all these rooks 

overlain wnconformably by the conglomerate of unknown age; aud the conglomerate in turn overlain 

conformably by a newer slate of unknown age.

"Thechief problems are, then, to determine which are older and which are newer slates, and to determine the age of the conglomerate and upper slate.

"As an indication of progress, we have the discovery by .Mr. Woodworth, just reported, of fossils 

in the slate of both Sornerville and Newton."

2 Contributions to the geology of Eastern Massachusetts. Boston Soc. Nat. Hist. Occasional 

papers, No. 3, 1880, p. 266.

8 0p.cit,p.l92.
VALCOTT.] SUMMARY MASSACHUSETTS. 271

According to Dr. M. E. Wadsworth1 the strata at the trilobite quarry 

dip a little west of south at an angle of 55°. This is nearly as given 

by Mr. Isaac Lea in 1858.2 It is quite probable that the variation in 

angle of dip mentioned by different observers is owing to the position 

of the exposures in the quarry, at the time of their respective visits, 

and by their mistaking the cleavage for the plane of bedding.

Dr. Crosby3 describes the rocks at Bast Point, Nahant, as composed 

of a very dark gray, almost black, compact slate, with a strike N. 60° E.j 

and nearly uniform northerly dip of about 40°. The slate is inclosed 

in, and extensively cut by, the coarsely crystalline pyroxenic rock of 

the Naugus Head series. The slate, except where it is vesicular, is of 

a uniform grayish black color and holds thin beds of limestone aggregating, perhaps, 20 feet of calcareous matter. The character of the 

limestone and its mode of occurrence are precisely like those of Mill 

Cove, in Weyinouth, 13 miles distant. The limestones are interstratified with the slate and not always distinguishable from it. The color 

is light gray and its texture varies from compact to finely crystalline 

or saccharoidal. Thin seams and veins of siliceous material become 

evident on the weathered surface.

In the iuterbedded limestones Mr. A. F. Foerste discovered in 1889 

traces of a species of Hyolithes which he identified as specifically the 

same as a species found in the decomposed limestones of North Attleborough 4 He proposed the name Hyolithes incequilateralis, but I think 

it is identical with Hyolithes communis, var. emmonsi, of the Lower 

Cambrian horizon at Troy, New York. He states that the Nahant limestones are the equivalent of the red slates in North Weyinouth; aud 

that it is very probable the red slates and included limestones are 

stratigraphically beneath the Braintree Paradoxides beds. Also that 

the red slates of Mill Cove, in North Weyinouth. are of Olenellus age 

and beneath the Paradoxides strata.

The district embracing the Cambrian rocks of Bristol County, Massachusetts, is well described by Prof. N. S. Shaler. He says:

Several geologists have observed the fact that between Providence, Ehode Island, 

and Wrenthara, Massachusetts, we have an extensive development of iuterbedded conglomerates, shaly slates, and sandstones, the whole separated from the other detrital 

deposits of this region by peculiarities of color. * » » Various conjectures have 

been made as to the age of these deposits. They have been thought by one observer 

to resemble the Trias, while others, owing partly to their position, have assigned 

them to the Devonian age.6

Prof. Shaler discovered fossils of the Lower Cambrian or Olenellus 

zone in this series of rocks in 1883, which for the first time gave data

1 On the relation of the Quinoy granite to the primordial argillite of Braintree, Massachusetts. Boston Soo. Nat. Hist. Proo., vol. 21, 1883, pp. 274-277.

2 [On the trilobite formation at Braintree, Massachusetts]. Phil. Acad. Soi. Proc., vol. 9,1858, p. 205.

3 Contributions to the geology of Eastern Massachusetts. Boston Soc. Nat. Hist. Occasional papers, 

No. 3,1880, pp. 195,261,262.

4 The Paleontological horizon of the limestone at Nahant, Massachusetts. Boston Soc. Nat. Hist. 

Proc., vol. 24,1889, pp. 261-263.

6 On the geology of the Cambrian district of Bristol County, Massachusetts. Bull. Mus. Couip. Zool., 

Harv. Col., vol. 16,1888, pp. 13,1(L
272 THE CAMBEIAN. [BULL. 81.

for determining the geologic age of the deposit. On the east the Coal 

Measures of the Narragansett Basin occur. On the west side he considers the rocks to be of pre-Cambrian age. as they consist mainly of 

gneissoid rocks of various composition, and a great area of dark greenish chloritic deposits which appear in part at least to be metamorphosed conglomerates and shales. Owing to the large amount of drift 

material covering the country, no absolute contact with the pre-Cambrian rocks was observed, nor is the overlap of the Carboniferous upon 

the Cambrian shown in any section. 

Of the rocks he says:

The Cambrian rocks exhibit very little sign of metamorphic action. The shales 

indicate a slight amount of infiltration, and in the conglomerates the pebbles all retain essentially their original character, save that they are sometimes slightly indented one into the other. The cement of the mass is not more altered than is usual 

with our unchanged conglomerates. Its general characters, save for its reddish color, 

is undistinguishable from the deposits of Millstone grit age in the neighboring coal 

fields.'

So far fossils have been found in rocks of this section which probably do not in 

the aggregate include more than 100 feet or so of the total section of the Cambrian 

series. However, as these deposits are of the same aspect, as all the red slates 

and conglomerates of the area, it appears at present reasonable to include all 

rocks of this description with the above-mentioned series. The total thickness of 

the section which I have termed Cambrian is not accurately determinable. It probally amounts to not far from 2,000 feet. In the main it consists of thin bedded shaly 

layers which occasionally pass intp moderately thick, fine grained, greenish and reddish slates. Intermingled with these in several levels we have a number of layers 

of conglomerate, perhaps as many as half a dozen distinct beds, varying in thickness 

from 200 to 300 feet. In all cases these conglomerates are frequently interrupted by 

thin layers of shale or sandstone. * * * The rocks from which the pebbles were 

taken are mainly identifiable in the western portion of the field before described.8

The sediments composing this Cambrian section appear to have been derived from 

rocks substantially the same as those which now lie in the field west of the area. 

Although fossils have been found in a small part of the section, close study makes it 

plain that by far the greater portion of the strata are clearly azoic. The frequent 

return of conglomerate layers and the coarseness of the pebbles show that during 

most of the time when the beds were accumulating the region was near shore; so, 

too, the large amount of sandy matter even in the slates affords a presumption that 

the region was not remote from the coast line. Abont 100 feet of shale beds have 

been subjected to a very careful search for organic remains. The total thickness of 

the deposits in which any trace of life has been found probably does not exceed 100 

feet, and even in this section only a small part of the rocks actually contain fossils. 3

Prof. Shaler suggests that the conglomerates were accumulated during an ice epoch j and he presents several arguments for this view. He 

states that the relations of the beds carrying the fauna at North Attleborough with those of the Paradoxides zone of Braintree are not discoverable by comparison with the Massachusetts Bay and Narragansett 

deposits. At the time he wrote the stratigraphic relation of the Olenellus fauna as found at North Attleborough with the Paradoxides 

fauna was not known, except that the Scandinavian geologists state

1 Op. oik, pp. 16,17. S 0p.cit.,p.l8. »0p.cit.,p.20.
WALCOTT.J ATLANTIC COAST RESUME. 273

that in their country, the Paradoxides zone, occupied a superior position 

to the Olenellus zone. With the knowledge we no w have of the stratigraphic succession of the Cambrian faunas, the Paradoxides beds of 

Braintree are considered to be superior to the Lower Cambrian rocks 

of Attleborough.

The physical characters and condition of the rocks constituting the 

formations referred to the Cambrian in this province indicate that they 

were accumulated not far from the shore line, and that several fluctuations in the level of the sea bed occurred during Cambrian time. On 

the coast of Labrador the accumulation of sand was followed by a 

deepening of the sea and the deposition of calcareous mud. That the 

depth was not profound, is shown by the character of the limestone and 

its fauua3 and the presence of lenticular masses of red and green shale. 

The 231 feet of sandstone, and 140 feet of limestone in the section represent only a portion of the Lower Cambrian or Olenellus zone. Two 

hundred miles to the south, on the west coast of Newfoundland the 

presence of 605 feet of slate beneath the alternating series of limestone 

and quartzite, over 1,000 feet in thickness, tell the same story of relatively shallow water accumulation.

On the Atlantic coast side, at Canada Bay, there are 2,500 feet of 

slate, conglomerate and eruptive rock, subjacent to a series of limestones and slates nearly 3,000 feet in thickness. There is here a greater 

development of limestone than anywhere to the south along the Atlantic coast line. It appears to have accumulated upon the bed of a 

protected sea not far distant from the shore and to have been frequently 

interrupted in deposition by the throwing down of a considerable thickness of argillaceous mud.

In southeastern Newfoundland the assembled sections have, according to Messrs. Murray and Howley, a thickness of nearly 6,000 feet, of 

which 128 feet are limestone, and the remaining portion argillaceous 

and arenaceous deposits. In the section on Manuel's Brook a conglomerate rests upon the pre-Cambrian gneiss, and upon the upper bed an 

irregular, arenaceous limestone in which layers of more or less pure 

limestone occur. This limestone-forming epoch was of very short duration, and was succeeded by an accumulation of clay that now forms a 

series of shales nearly 1,000 feet in thickness before sandy layers appear. When once the sandstones begin to alternate with the shales, 

they continue on up to the summit of the group and are very abundant 

in the Upper Cambrian. The sediments of southeastern Newfoundland 

were accumulated in bays of the pre-Cambrian sea and derived almost 

entirely from the adjacent shore, either a« sand and silt, worn from the 

rocks by the sea, or brought down to it by tributary streams.

The 4,000 feet or more of rocks in the New Brunswick section are 

almost entirely shales with a few sandstones and basal conglomerates. 

BulL 81= 18
274 THE CAMBRIAN. [BULL. 81.

It is the record of the accumulation of sediments in a gradually deepening sea.

The eastern Massachusetts section is largely formed of shale, except 

in the lower part, where a small proportion of limestone occurs in the 

Olenellus zone, much as in the southeastern Newfoundland section.

The great thickness of shales referred to the Cambrian in Nova 

Scotia, Maine, and New Hampshire probably represents much more 

than the Cambrian group, or it may be entirely a pre-Cambrian formation or a post-Cambrian formation. It is only probable that they are of 

Cambrian age. They may represent deep-water accumulations in which 

no organic remains were buried.

As a whole, we may regard the Atlantic Coast Province, during Cambrian time, as including bays and the adjacent shores of the Algonkian 

land, in and along which sediments, mostly of an argillaceous and 

arenaceous character, accumulated. The relative level of the sea bed 

varied, but in the main the depression greatly exceeded the elevation. 

The depth of water in which the sediments forming the limestones and 

shales accumulated was probably considerable, but not a deep sea in 

the present sense of the term. A few hundred or a thousand feet on a 

gradually sinking sea bed (in relation to the coast line) would give the 

required conditions. From the character of the sediments and the 

faunas it is probable that land barriers existed to the eastward of the 

present coast, and that none of the deposits were accumulated off the 

shore facing the open ocean.

As left by erosion the Lower Cambrian now occurs on the Labrador

coast, on the western and eastern sides 

of Newfoundland, in New Brunswick, 

and eastern Massachusetts. The Middle Cambrian has been recognized on 

the eastern coast of Newfoundland, in 

New Brunswick, and eastern Massachusetts. The Upper Cambrian is

M.C.

L.C. known in southeastern Newfoundland,

A!_ A* ''^S&SAU

ii^ir e Cape Breton Island, New Brunswick 

, ,, ... ,. and doubtfully on the southwestern TIG. 1. Typical sections of the Atlantic *;

Coast Province. Vertical scale, 6,400 feet COast Of Newfoundland. (See PI. II.) 

to the inch.

APPALACHIAN PROVINCE.

The Appalachian Province includes the outcrops of Cambrian strata 

on the line of the Appalachian System of Mountains, from the Gulf of 

St. Lawrence on the north to Georgia and Alabama on the south.

For convenience in presenting geologic data the Appalachian Province is divided into:

A. Northern Appalachian District. 

B. Southern Appalachian District.
WALCOTT.J SUMMARY NORTHERN APPALACHIAN. 275 

NOKTHERN APPALACHIAN DISTRICT.

The Northern Appalachian District includes the Hudson Eiver and 

Lake Cham plain area, east of the river and lake, and an extension 

northeastward into Canada as far as the vicinity of Cape Eosier on the 

Gulf of St. Lawrence.

The geographic distribution of the Cambrian strata of the Northern 

Appalachian District, south of the Canadian extension, is delineated on a geologic map of eastern New York and western Vermont 

published in 1888 by Mr. C. D. Walcott.1 On this map the « Granular, Quartz," "Eed sandrock," "Georgia slate," and Potsdam sandstone are differentiated as far as the known data would permit. 

The stratigraphic relations of the various divisions in Vermont are 

shown in a series of sections by Prof. C. H. Hitchcock,2 and for New 

York by a section on the above-mentioned map.

The " Granular Quartz" is found on the western side of the Archean 

rocks, from southeastern New York and western Connecticut northward 

to Massachusetts, and into Vermont nearly to the Canadian border. Tbe 

exposed outcrop is more or less interrupted because of the removal of 

the rock by erosion or its concealment by superjacent deposits.

In Vermont the " Granular Quartz" is a very compact, hard rock that 

passes into a number of varieties. It is described in the Geology of 

Vermont 3 as granular, gray, or reddish quartz rock; fine granular or 

arenaceous quartz rock: granular porous quartz, or pseudo-buhrstone; 

quartzose aggregate; quartzose breccia;. quartzose and micaceous conglomerate. There are also associated with it talcose and inica schists 

and limestone. The quartzite is remarkably compact and enduring, 

and it occurs in bowlders all over the southern part of Vermont, in 

Massachusetts, New York, and Connecticut, many miles from the parent 

ledges. Along the range of the rocks the bowlders cover the surface, 

and in some instances this is the only way in which the line of outcrop 

of the formation is indicated. Details of the geographic distribution 

in Vermont are given in volume 1 of the Geological Survey. A section of 973 feet was measured in East Dorset by Prof. C. H. Hitchcock, 

ami the thickness of the formation in 'Vermont is estimated at 1,000 

feet. It retains its essential characters in passing southward into 

Massachusetts, New York, and Connecticut.

On the western summit of Clarksburg Mountain, northeast of Williamstown, the basal bed of the quartz series is a conglomerate, resting 

unconformably upon pre-Oambrian gneiss. The conglomerate is succeeded by beds of quartzite, usually compact, hard, fine grained, and

'The Taconic system of Emmons and the use of the name Taconic in geologic nomenclature. Am. 

Jonr. Sci., 3d ser., vol. 35,1888, pp. 229-242, 307-327, 394-401.

"Geological sections across Vermont and New Hampshire, Am. Mus. Nat. Hist. Bull., vol. 1,1884, pp. 

155-179, pL xvi, xvii.

8 Hitchcock, C. H. Hypozoic and Paleozoic rocks. Eeport on the geology of Vermont, vol. 1,1861, 

p. 342.
276 THE CAMBRIAN. [BULL.81.

of a light gray color, in layers varying from a few inches to 2 or 3 feet 

and even up to 6 feet in thickness, on the spurs to the north of Clarksburgh Mountain. In the town of Benningtou, a few miles further 

north, the writer measured a section of the 'quartzite 400 feet in thickness. It is formed largely of light gray, nearly white, compact, fine 

grained, and massive bedded quartzite, with alternating beds of hyaline 

quartz. At this locality fossils other than the Scolithus borings, which 

were known to occur at a number of localities in Vermont, were found 

in 1887 for the first time in situ in the quartzite. The species belong 

to the genera Nothozoe, Hyolithes, and Oleuellus. Traces of a trilobite, apparently of the genus Olenellus, were also found 100 feet above 

the gneiss on the western summit of Clarksburg Mountain. In the 

bowlders on the line of the outcrop of quartz, to the north of Beuniugton, traces of fossils have long been known, among which are Notliozoe 

vermontana, Hyolithes communis, and Olenellus thompsoni.

Prof. J. D. Dana describes the quartzite in its extension into western 

Massachusetts, western Connecticut, and eastern New York. It varies 

very little from the characteristic features shown at the north, and 

from its disturbed condition no sections were obtained of its entire 

thickness. At Stissing Mountain, in Dutchess County, New York, it 

rests upon the Archean, and is a massive bedded, compact quartzite, 

in which the genus Olenellus and Camerella minor have been found. It 

here passes above into a limestone in which Hyolithellus micans, a characteristic Lower Cambrian species, occurs.1

In a paper read before the Geological Society of America at its second annual meeting, December 30, 1890, Dr. J. E. Wolff gave an account of the discovery, by Mr. A. F. Foerste and himself, of fossils of 

Lower Cambrian age in the limestones of the Bast Eutland Yalley. 

The limestones rest conformably upon the quartzite which carries 

Olenellus in Benuington County. Dr. Wolff identified the species as 

Kutorgina sp. ? and Salterella.2 The evidence of the Lower Cambrian 

age of the limestones is not fully proved, as the two genera may range 

up into the Middle Cambrian.

He mentioned that in the West Eutland Yalley, and in the valley 

between the West Rutland and East Eutland Valleys, the limestones 

contain fossils of Calciferous Chazy-Trentou age, or those which will 

be found above the Cambrian horizon. From his section it is probable 

that the Middle and Upper Cambrian faunas will be found to range up 

into the limestones beneath the Calciferous horizon, as has been discovered by Prof. W. B. Dwight in Dutchess County, New York, and 

Prof. Frank Nason, in Sussex County, New Jersey.

As a whole, the "Granular Quartz" may be said to consist of ashore 

deposit accumulated along the western shore of the Green Mountains

1 The Taconic system of Emmons and the use of the name Taconic in Geologic nomenclature. Am. 

Jour. Sei., 3d ser., vol. 35,1888, p. 236. 

3 Ball. Geol. Soc. Am., vol. 2,1891, pp. 334,335.
WALPOTT.] SUMMARY NORTHERN APPALACHIAN. 277

during early Cambrian times; the sediments my from pure quartz 

sand to mixtures of sand and argillaceous and calcareous mud.

The "Bed Sandrock" series is confined almost entirely to northern 

Vermont, not appearing south of Addison County. In the northern 

part of Addison County it comes into contact with and merges into the 

" Granular Quartz " series. It has not been recognized in contact with 

the Archeau rocks of the Green Mountains. From this, and its having 

less of the character of a shore deposit and from its occurring west of 

the line of outcrop of the " Granular Quartz," it is quite probable it is 

a deeper water accumulation, though contemporaneous with the "Granular Quartz." The Georgia slates, in the town of Georgia and in northern Vermont, are conformably superjacent to the "Red Sandrock." 

As the formation is traced to the south, the " lied Sandrock" series 

disappears, and the Georgia slates and shales, with their interbedded 

limestones and sandstones, represent the entire Cambrian section; so 

it is very probable that the Georgia series as found in southern Vermont and eastern New York represents or is equivalent to the " Granular Quartz" and the "Ked Sandrock." The "Granular Quartz" has 

been described separately, but it is more convenient to unite the "Red 

Sandrock" and the Georgia slates, because the sections usually show 

the latter resting conformably upon the "Red Sandrock" series throughout northern Vermont. The geographic distribution of the Canadian 

extension of the "Red Sandrock" and the Georgia slates is shown on 

a map by Sir Wm. E. Logan, entitled " The distribution of the rocks 

belonging to the Potsdam, Quebec, and Trenton groups of the east side 

of Lake Charaplain," accompanying an Atlas of maps and sections of 

the Report of Progress of the Geological Survey of Canada for 1863, 

published iu 1865. The formations extend north of the boundary line 

about 5 miles, where they appear to have been cut out by faults that 

bring the superjacent formations into contact with them.

The "Red Sandrock" series consists of white and red dolomites and 

sandy layers. Some of the strata are mottled red and white, and a few 

are brick red or Indian red. Some beds contain a considerable amount 

of siliceous sand, and all weather a yellowish or reddish brown. They 

are also iuterbedded with gray argillaceous limestones and buff sandy 

dolomites weathering brown. This description is taken from Logan's 

notes on the formation near the Canadian boundary. To the south, in 

the town of Georgia, Franklin County, Vermont, they form a bluish 

gray dolomitic limestone, followed by a steel-gray dolomitic limestone 

that passes into a mottled limestone or the Winooski marble. This in 

turn is subjacent to gray dolomitic limestones in massive layers, some 

of which are mottled reddish and white, though the larger part are gray 

and yellow. Still higher up the reddish pink dolomitic limestones appear. There are many variations in the color and composition of this 

series between the Canadian border and its point of disappearance 40 

miles to the south.
278 THE CAMBRIAN. s [BULL.a.

The Georgia slate series, according to Prof. C. H. Hitchcock, consist 

in Vermont of several varieties of rock.1 They are (1) clay slate; (2) 

roofing slate; (3) clay slate approximating to micaceous sandstone; (4) 

various kinds of limestone; (5) brecciated limestone; (6) conglomerate 

formed of pebbles of limestone.

A carefully measured section extending up through the " Red Sandrock " and Georgia series, beginning at the base of the western face of 

the cliff overlooking the level that reaches to the shore of Lake Chainplajn, in the town of Georgia, Franklin County, Vermont, and extending southeastward to Barker's quarry, a little south of the Georgia 

post-office, gives the following: 2

Feet 

(ij Massive bedded, bluish gray dolomitic limestone, with many inosculating

threads and bunches of a yellowish-drab sandy limestone that weathers

in relief3 .............................................................. 35

(2) No. 1 passes into a steel-gray dolomitic limestone that weathers to a dark 

buff and bluish black, with angular fragments of bluish gray limestone 

appearing irregularly at the surface. At 160 feet from the base the first 

band of mottled limestone, "Calico" or Winooski marble, is met with. 

The latter grades into a reddish dolomite, free from mottling, and then in 

a gray limestone. (Fossils, Hyolithellus f)............................ 200

(3) Gray dolomitic limestone in massive layers, some of which are mottled, reddish and white, but the larger part are gray and yellow. Many of the 

gray layers break up iuto a columnar structure, the columns 'being at 

right angles to the bedding. In a reddish-colored limestone, 200 feet from 

the base, a slender elongate tube occurs, probably Hyolithellus micans . .. 475

(4) Eeddish pink, dolomitic limestone, weathering to a reddish brown and decomposing on the exposed edges to an arenaceous, dark, brownish-red 

rock that shows numerous fragments of fossils: Kutorgina labradorica, 

Obolella (?) sp., Salterella pulchella (?), Plychoparia adamsi, Olenellus 

thompsoni ............................................................. 100

(5) Gray .arenaceous limestone in rough, massive layers, passing into more 

evenly bedded, light gray, arenaceous limestone. Fossils similar to those 

in 4 occur in the lower portion ........................................ 190

Total thickness of limestone........................................... 1,000

(0) Georgia shales. Argillaceo-micaceous and arenaceous shales, containing 

numerous fossils, at Parker's ledge, and showing deposition contact on 

No.5................................................................. 200

Strike at Parker's Quarry, N. 30° E., dip 8° to 12° E.

The fossiliferous shales at Parker's Quarry contain: Palaiophycus i»- 

cipiens, P. congregalus, Diplograptua simplex [now, 1891, Phyllograptus (f) 

cambrensis"], Climacograptus (?) emmonsi, Eutorgina cingulata, Orthisina orientalis, O.festinata, 0. transversa, 0. sp. (?), Microdiscusparkeri, Mesonacis 

vermontana, Olenellus thompsoni, Olenoides tnarcoui, Sathynotus holopyga, 

Ptychoparia adamsi, P. vulcanus, Protypus hitchcoelci, P. sencctus, and 

P. senectus vax.parvulm.

1 Hypozoio and Paleozoic rocks. Eeport on the geology of Vermont, vol. 1,1861, p. 358.

2 Walcott, C.D. Second contribution to the studies of the Cambrian faunas of North America. TJ. 

S. Geol. Survey, Bull. No. 30,1886, pp. 15,17.

3 A mile south of the line of the section about 75 feet of arenaceous limestone occurs beneath tliis 

bed. Fifty feet from the base I found during the summer of 1890 Obolella crassa, I, Salterella, sp. ? 

Hrjolithes 2 sp., and fragments of a species of OleueUus. A few foot higher in the section the heads of 

P rotypns sp. ? and of Olenellus sp. ? were found. Traces of the Olenellus fauna were also found at points 

85,153, and 103 feet above the lowest horizon.
WALCOTT.] SUMMARY NORTHERN APPALACHIAN. 279

Feet.

(7; East of the Parker quarry the rocks are argillaceous shales, with occasional 

layers of hard gray limestone one-half of an inch to 2 inches thick, that 

carry numerous fragments of a liuguloid shell.......................... 3,500

Strike of shales near top of 7, N.40° to 60° E., dip 60° SE.

(8) Light gray quartz ite...... i............................................. 50

(9) Gray limestone in massive layers, with occasional intercalated bands of 

hard argillaceous shale similar to that beneath the limestone. Many of 

the beds of limestone appear to have been broken up into fragments and 

recerneuted in situ ........................................ - ....... 1,700

Average strike of limestone beds N. 50° E., dip 50° to 90°; average dip 

GO0 SE.

In this limestone belt, 1 mile north of where the section crossed, a few 

fossils were found; Lingula, n. sp., Orthisinann&t. (fragment), Camerclla 

undt. (probably new), Agnostus like A. orion, and Ptychoparia like P. 

adamsi.

(10) Argillaceous shales, very similar to those in the Parker ledge, continue on 

up to the opposite side of the line of the Vermont Central Railroad track. 

At the base the shales rest conformably against the limestone of 9, and 

above appear to be cut off by a fault.

Strike N. 50° E., dip 60° to 80° SE., for a distance beyond the limestone; 

the dip then decreases and does not exceed 20° for a long distance, until 

within 1,000 feet of the railroad track, where the shales become coarser 

and changed by addition of arenaceous material, and the dip increases.

Total thickness to fault line of No. 10, :3,500 to 4,500 feet.

No. 8 of the section when traced on its strike to the southwest increases in force 

very rapidly to the thickness of 500 feet or more, and also changes from a quartzite to 

a more or less calcareous sandstone, containing irregular fragments of argillaceous 

shale. Followed to the northeast, it soon disappears and the limestones rest directly 

on the shales. Continuing northeast on the limestone (9), it is found to decrease rapidly, and a mile northeast of where it is over 1,500 feet in thickness the width across 

the outcrop is not over 150 feet, and soon the shales above it and those below it come 

together, the limestone having disappeared. Southwest of the line of the section the 

width of the outcrop narrows, and north of Georgia Plains post-office the entire 

section is covered by beds of sand.

No. 9 appears to be a great lenticular mass of limestone (lentile of Marcou) with 

intercalated beds of argillaceous shale, and more rarely with arenaceous beds imbedded 

in the argillaceous shales. The fauna is Cambrian in character, and, in the absence 

of Oleuellusand other typical Middle [now Lower] Cambrian fossils approaches that 

of the Upper Cambrian or Potsdam sandstone.

A section taken east of Highgate Springs beginning on the east 

side of the same fault as the Georgia section, gives a slightly greater 

thickness^ and more arenaceous matter in the limestone series beneath 

the Georgia shales. The limestones are here 1,170 feet in thickness and 

the Georgia shales 1,000 feet, above which there is apparently a conformable series of calcareous sandstones, with a thickness of 850 feet, to 

where they are cut off by a fault line. A section measured east of the 

village of Swanton, does not show as great a thickness of the limestone 

beneath the Georgia shale, and a fault line cuts obliquely across the 

shale. On the east side of the fault 200 or 300 feet of shales occur, aiyl 

many layers of conglomerate limestone, the fragments of limestone 

varying in size from small pebbles to masses 6 feet in diameter. The
280 THE CAMBRIAN. [BULL. 81.

fossils in the limestone conglomerate have an Upper Cambrian aspect, 

and include Lingula sp. f, Agnostus sp.?, Amphion sp.f, Batliyurus sp. 9 

Below the horizon of the conglomerate and in situ in the shales, there 

were found the genera Lingulella, Agnostus, Ptychoparia and Solenopleura. With the exception of the Solenopleura the species appear to be 

identical with those of the limestone lentile (9) of the Georgia section. 

A section measured east of Swanton by Sir William E. Logan gave but 

520 feet of the limestone (Bed Sandrock) series.1 But farther to the 

north, nearly on the line of the Canadian boundary, he found 1,410 feet 

of limestone in the section, proving that this portion of Cambrian terrane thickens rapidly to the north.

The section measured in the town of Georgia is the most complete yet 

taken in Vermont (ante., pp. 278,279). At the base a great belt of dolomiticlimestone 1,000 feet in thickness rests against, and, by an overthrust 

fault, overlaps the Trenton limestone of the Lower Silurian (Ordovician). 

What was originally beneath the Cambrian limestone is yet undetermined. 

In the High gate section the limestone belt is nearly 1,200 feet thick. The 

base is unknown, and it does not appear, so far as 1 know, in the section 

between the boundary of the United States and Canada and the outcrop in the town of Georgia. I have suggested that the great mass of 

shaly argillite east of the Vermont Central Railway track in the Georgia 

section may be older than the limestone at the base of the section, but 

until further evidence is obtained this is merely conjectural.2

During the field season of 1890 I studied the " Red Sandrock " series 

of the Georgia section, and found a little to the south and at the base 

of the original section that there was a band of buff-colored calcareous 

sandstone some 50 feet in thickness. In the upper beds of this, Obolella, like Obolella crassa, Hyolitlies americanus, H. communis, H. sp. 

uudt., Eyolithellus micans, and fragments of Olenellus occur. In a leadcolored inagnesian limestone, passing into a buff-colored limestone 15 

feet above the sandstone, fragments of Olenellus and the head of Ptychoparia, apparently identical with P. trilineata, were found, and in the 

superjacent pinkish magnesian limestone with interbedded drab-colored 

limestone, at horizons of 85 feet, 113 feet, and 198 feet above the sandstone, fragments of fossils that I recognized as portions of Olenellus and 

very perfect specimens of Salterella spJ occur in the decomposed silicious limestones.

The discovery of the Olenellus fauna in the lower portion of this magnesian limestone series gives the fauna a range through 1,000 feet of 

limestone and the 250 feet of superjacent Georgia shale.

The fragments and heads of the genus Olenellus that were found in the 

lower beds were not sufficient to determine whether it was the equivalent of the Olenellus asaphoides of the Washington County section or not.

* Geological Survey of Canada: Report of progress from its commencement to 1863. Montreal, 

1863, p. 281.

2 Walcott, C.D.: Second contribution to the studies of the Cambrian faunas of North America. 

TJ. S. GeoL Surv., Bull. No. 30,1886, p. 19.
SUMMARY NORTHERN APPALACHIAN. 281

It is quite probable that.it is, from the character of the associated 

fossils. As the vertical distribution of the fauna in the Olenellus zone 

will be treated of in a future paper, furtiher reference will not be made 

to it at present.

The shales and slates super)acent to the Olenellus-bearing beds of 

the Georgia slate, at Barker's quarry, do not apparently belong to the 

Lower Cambrian, but are the representative of the middle portion of 

the Cambrian section. This view was advanced by Prof. Jules Marcou, 

in 1885, 1 except that he placed the same series of shales which occurs 

at St. Albansbeneath the Georgia slates or Olenellus zone. The stratigraphy was erroneous, but the suggestion that the St. Albans slates correspond to the Paradoxides belt of the Atlantic Coast area will probably be found to be correct. In such an event Professor Maroon's name 

St. Albans will be a useful addition to the nomenclature of the Cambrian group in northern Vermont. It will, however, be difficult to differentiate between the St. Albans group and the superjacent beds carrying 

the Upper Cambrian fauna.

In the group of sections taken across New Hampshire and Vermont 

by Prof. C. H. Hitchcock2 the Georgia series is called Potsdam and 

Cambrian ; and in section xi, on PI. 17, the Georgia shales (Cambrian 

of section) are represented as resting conformably on the magnesian 

limestone (Potsdam of section) in the town of Milton. This is the same 

as in the Georgia section a few miles to the north. The great mass of 

argillites, oast of the railroad track in the Georgia section, are placed 

under the term Cambrian by Prof. Hitchcock, and the reference may 

possibly be correct; but as yet there have not been any recognized 

Cambrian fossils obtained in it, either at this point or to the north or 

south.

In southern Vermont the Georgia slate series widens out, and includes 

the great roofing-slate belt that extends through. Kutland County and 

into Washington County, New York. The outcrop of this series is narrow in the south part of Washington County, but it widens rapidly in 

Rensselaer County, occupying nearly the entire width of the county at 

its southern boundary. At its greatest point of development in Washington County it consists of the following strata, as shown in a section 

crossing the county in the towns of Greenwich and Salem, with its base 

1£ miles west of North Greenwich' post-office:

Eeet.

(1) Massive layers of impnre, shaly limestone embedded in irregular argillaceoarenaceous shale, with numerous fossils of the Olenellus fauna in the 

limestone............................................................. 340

(2) Massive layers of fine-grained, bluish gray, arenaceous limestone, that become almost a pure limestone in. places ................................ 670

About halfway of the mass Lingulella coslata, Hyolithellus inicans, and 

Leperditia dermatoides occur.

1 The Taconio System and its position in stratigraphic geology. Am. Acad. Proc., vol. 20,1885, table 

on p. 224.

* Geological sections across Vermont and New Hampshire. Am. Mas. Nat. Hist., Bull., vol. 1,1884, 

pis. 16,17.
282 THE CAMBRIAN. [BULL. 81.

. Feet.

(3) Shaly limestone in massive layers; argillaceous shales interbedded in the

layers .........................._................................_ 380

(4) Calcareous, argillaceous shales, in massive layers, with interbedded arenaceous limestones below, and passing into an argillaceous shale above... 240

(5) Dark, argillaceous, and arenaceous shales becoming fissile in places; occasional layers of a hard, gritty limestone 1 or 2 inches thick occur at 

various horizons. Near the summit of this section Hyolithes americanus, 

Microdiscuspulchellus, Olenellwasaphaides, and Conocoryphe trilineala occur 

near the roadside. This is the trilobite bed from which the original 

specimens described by Dr. Emmons were obtained ..................... 370

The section to this point gives a total of 2,600 feet, and is considered 

Division A of the section.

(6) Compact, steel-gray, massive-bedded argillaceo-argillaceous shale, breaking

into irregular fragments, and weathering a rust-brown color... ..... 2,200

At a point 1,300 feet up in this I found Stenotheca rugosa, Hyolithes amer? 

icanus, and fragments of Olenellus asaphoides. At 2,100feet up fragments 

of Olenellus occur in a stratum of calciferous shale.

(7) Massive beds of a thinly banded, cherty, and argillaceous rock, capped by

a band of calciferous sandrock ........................................ 400

(8) Argillaceous shale, more or less arenaceous and calcareous throughout its

extent................................................................ 2,400

(9) Calciferous sandrock, light colored, weathering to a reddish brown, crumbling sandy rock. This is embedded in a calcareo-argiHaceous rock, that 

breaks into angular fragments of a shaly character. The only fossils ob-. 

served were Obolella orasaa, Hyolithes, fragments uf Olenellus, on the 

decomposed surfaces of the more calciferous layers..................... 900

(10) Argillaceous and arenaceous shales, much like those of Nos. 8 and 9, with 

bands of bluish gray, evenly bedded, and conglomerate limestone carrying fossils. As shown in the section, this division appears to have a thickness of 4,500 feet; but it is assumed that there is much repetition by 

faulting, so that it is given a thickness of 2,250 feet.................... 2,250

The combined thickness of the section to this point is 10,750 feet. Its 

continuity is here broken by a fault, that brings the rocks of the Hudson (?) terrane against it and between it and the purple and green slates 

that form a large portion of the Cambrian section east of the rocks of 

the Hudson (?) terrane. The section is again taken up ou the east side 

of Salem Village, at the base of the green and purple slates and interbedded limestones, carrying characteristic Lower Cambrian fossils of 

the Olenellus fauna.

Feet.

(11) Green, purple, and higher up, gray and dark shales and slates and interbedded limestones, in very thin layers ................................. 2,500

(12) Nonfossiliferous green and purple slates ........................ ........ 2,150

In the township of Hampton to the north, the green and purple slates 

appear to have a thickness of 4,300 feet; and 2 miles north of that point 

there are over 5,000 feet of these beds, if no repetition occurs.

The lower portion of this division is characterized by the Olenellus 

fauna in association with some other species that indicate the Middle 

Cambrian zone. The entire thickness of the lower and upper divisions, 

according to the section, is 15,350 feet.

(13) Above the green and purple slate belt is a series of greenish, schistose, 

hydro-mica slates, estimated to have a thickness of 3,700 feet. They are 

not fossiliferous, and appear to pass beneath the limestones characterized
WALCOTT.] SUMMARY NORTHERN APPALACHIAN. 283

by the Chazy-Trentou fauna. I have referred them to the Potsdam zone 

provisionally. 1 If this reference he correct and the rocks in the section 

are not duplicated hy faulting, the Cambrian system has a thickness of 

19,000 feet in Washington County.

This section may be greater than the actual thickness of the sediments deposited in this region during Cambrian time. The upper 3,700 

feet of greenish, hydro-mica shales probably do not belong to the 

Cambrian, and there may be some reduplication in the section as measured. Eliminating the probable sources of error, 1 think there is at 

the least from 10,000 to 12,000 feet of strata that may be referred to the 

Cambrian group.

A section 35 miles to the south, across the extension of this series, 

exhibits a great development of the shaly portion similar to that in the 

lower part of the Washington County section, that passes above into 

the red and purple slate belt. In this section the upper member 

of the Washington County section is apparently represented by a 

coarse, greenish sandstone, and in places a fine conglomerate. At the 

base of this formation the red and green shales are interbedded with 

the sandstone, the passage from, the slates to the sandstone being by 

intercalation of sand and slate for a distance of several hundred feet, the 

slate gradually diminisliing in volume as the intercalation of the sandstone increases. The sandstone is estimated to have a thickness of 2,000 

feet or more, and it corresponds in stratigraphic position, and is on the 

strike of the 3,700 feet of greenish hydro-mica schistose shales of the 

Washington County section. The recent work of Mr. T. Nelson Dale 

proves this series (Berlin grit) to be of Lower Silurian (Ordovician) age, 

and indicates that the series of green and purple slates beneath may 

represent the base of the Lower Silurian (Ordovician) and the summit of 

the Cambrian.

Our knowledge of the rocks of the Cambrian group in their southern 

extension into Dutchess County, New York, is obtained from the observations of Prof. Win. B. Dwight. The base of the series is the " Granular Quartz" of Stissing Mountain, that had been referred to the 

Potsdam zone by Profs. W. W. Mather, J. D. Dana, and others. Occurring between the gneiss of Stissing Mountain and the super]acent limestone carrying the Calciferous fauna, it was natural that this should be 

correlated with the Potsdam sandstone about the Adirondacks; and it 

was not until the fall of 1886 that fossils of the Lower Cambrian or 

Olenellus zone were found in the quartzite, and in the limestone resting 

upon the quartzite.2 Prior to this Prof. Dwight had discovered in the 

more or less arenaceous limestone and argillaceous shaly limestone 

near Poughkeepsie the presence of the Potsdam or Upper Cambrian

1 Walcott, C. D.: The Taconic System of Einmons and the use of the name Taconic'in geologic 

nomenclature. Am. Jour. Sci., 3d ser., vol. 35,1888, p. 241.

a Dwight, W. B.: Primordial rocks of the Wappinger Valley limestones and associate strata. 

Vassar Brothers lust. Trans., vol. 4,1887, pp. 206-214. Aru. J our. Sci., 3d ser., vol. 34,1887, pp, 27-32.
284 THE CAMBRIAN. [BULL.81.

fauna.1 It includes Lingulepis acuminata, Obelella pnma, Ptycltoparia 

calcifera, and P. saratogensis, species identical with those found at the 

upper horizon of the Potsdam in association with Dikelocephalus of 

Saratoga County, New York. Subsequently he discovered in the limestone above the quartzite, at the south end of Stissiug Mountain, fossils 

that indicated the Middle Cambrian or Paradoxides zone. The species 

are Hyolitlies billingsi ?, Leperditia ebenina, Kutorgina stissingensis, and 

Olenoides stissingensis.

The stratigraphic succession is more or less interrupted by faults and 

the rocks are masked by the drift deposits. The succession as determined by the known stratigraphy, and the fauna is, first, at the base a 

massive bedded quartzite, resting upon the gneiss below, and subjacent 

to a bed of hard, compact limestone. In the quartzite the Olenellus 

fauna has been found, and in the bed of limestone immediately superjacent to it one of the characteristic fossils of the Lower Cambrian 

fauna, Hyolithellus micans occurs. In the superjacent limestone, the 

thickness of which could not well be determined but which appears 

to be considerable, the Middle Cambrian fauna was found in an arenaceous limestone, passing frequently into a calcareous shale; and in 

the vicinity of Poughkeepsie the Upper Cambrian fauna occurs in a 

somewhat similar limestone.

The contrast of the sedimentation of this section with that of Washington County is very striking. In the latter, the quartzite of Stissing 

Mountain is represented by the great thickness of shales, and interbedded limestones, slates, and sandstones; and the limestone of the 

Middle and Upper Cambrian of the Dutchess County section are entirely 

replaced by slates, schists, and sandstones, both in Bensselaer and 

Washington 'Counties. This difference in sedimentation is shown all 

along the northern Appalachian Province from Dutchess County to the 

Canadian border, and on to Quebec and down the St. Lawrence River 

to Cape Eosier. It represents the accumulation of sediments in a gradually sinking area and in a relatively shallow sea. It is a curious fact 

that near the old shore line the basal sandstone, " Granular Quartz " 

of the Lower Cambrian is almost directly succeeded by the massive 

limestones of the " Marble " belt. Unless there is here an area of nondeposition, the lower portion of the limestones of Berkshire County, 

Massachusetts, .Rutland and Addison Counties, Vermont, represent the 

sedimentation, of Middle and Lower Cambrian time.

The preceding paragraph was written several months prior to the 

discovery of Cambrian fossils in the limestones of the East Rutland 

Valley by Dr. Wolff, in 1890.

'Discovery of fossiliferous Potsdam strata at Poughkeepsie, N. Y. Am. Assoc. Proc., vol. 34,1880, 

pp. 204-209.

2 Recent explorations on the Wappjnger Valley limestone of Dutchess County, New York., No. 5 

discovery of fossiliferous Potsdam strata at Poughkeepsie, N. Y. Am. Jour. Sci. ,3d ser., vol. 31, 

1886, pp. 125-133. Vassar Bro. Inst., Traus., vol. 4,1887, pp. 130-141.
WALCOTT.] SUMMARY NORTHERN APPALACHIAN. 285 

CANADIAN EXTENSION.

The Canadian extension of the northern Appalachian district is from 

the United States boundary northeast to the vicinity of Point Levis, 

Quebec, on the western side of the extension of the Green Mountains, 

or Sutton Mountain anticlinal, and from Quebec down the south shore 

of the St. Lawrence Eiver to Cape Rosier, Gaspe. On the eastern side 

of the anticlinal the supposed Cambrian rocks of New Hampshire, crossing the southeastern portion of the Province of Qujebec to the Maine 

boundary, are also included.

The stratigraphic succession of the rocks referred to the Cambrian in 

the eastern Province of Quebec and down the St. Lawrence Eiver to 

Cape Eosier is not yet clearly determined, owing to the faulting, plication, and absence of clearly denned Cambrian faunas in situ in the 

strata. In the vicinity of Quebec, on the authority of Dr. E. W. Ells, 

the stratigraphic succession is as follows: 1

(1) Black, green, and gray shales, with hard and heavy hands of grayish, sometimes yellowish white, quartzose sandstone, which are thickest in the lower portion, 

and with occasional thin hands of limestone conglomerate, the pebbles being generally small and the paste highly quartzose. The quartzites have occasional scattered 

pebbles of grayish limestone.

(2) Greenish, grayish, and blackish, with occasionally dark-reddish or purplishtinted shales, with bauds of hard grayish sandstone, generally fine-grained, and in 

thickness from 1 inch to 1 foot, the massive quartzites being absent and many of 

the greenish layers being covered with fucoidal markings, well seen on the shore 

above Cape Rouge and in the cutting along the road above that village.

(3) Bright red shales, often with thin greenish or grayish bands, which in places 

are calcareous. The rocks on a smoothed surface have a striped red and green aspect; 

in the upper part occasional beds of a foot or more of hard green-gray sandstone 

occur.

(4) Red, greenish gray and black shales, with interstratified masses, often lenticular, of greenish and grayish Sillery sandstone, ranging in thickness* from 2 feet 

upward, in which the Sillery quarries are located. This is the typical Sillery sandstone, which ranges from a fine-grained homogeneous rock to a fine quartz conglomerate, much of the rock being characterized by the presence of small flaky pieces of 

shale and scattered small pebbles or large grains of clear quartz, the bands of sandstone being separated by partings of various colored shale. The local and lenticular 

character of the sandstone is well seen in the Sillery section, some of the heaviest 

beds inland thinning out before reaching the shore in either direction. In the upper 

part, at Sillery church, Ololella pretiosa occurs, from which point an anticlinal 

crosses the river to Point Levis, and appears in the cliffs at the Victoria hotel, where 

the same Obolella is found.

Above the Upper Sillery Dr. Ells places the Levis shales and conglomerates of Levis City, the shore extension below South Quebec and 

St. Joseph and the west end of Orleans Island. In the Levis shales, 

the conglomerate limestone, embedded in a calcareous matrix, carries 

numerous bowlders in which the Upper Cambrian fauna is found ; and 

in what is supposed to be the equivalent of No. 2, a conglomerate lime1 Second report on the geology of a portion of the Province of Quebec. GeoL Surv. Canada, new 

 er., voL 3, part 2,1889, pp* 63 K, WK.
286 THE CAMBRIAN. [BULL. 81.

stone occurs in which the Olenellus or Lower Cambrian fauna is present. The thickness of the strata referred to the Cambrian is not given 

by Dr. Ells in his publication, but he told me that the measurements 

given by Mr. Logan were as nearly correct as could be determined. 

These were 5,000 to 6,000 feet for the Sillery and Lauzon series.

The little shell Obolella pretlosa ranges through from 1,500 to 2,000 

feet of the Upper Sillery; and the lower or Olenellus fauna conglomerate occurs in the lower portion of this range.

Dr. Ells refers the entire Sillery series to the Cambrian, and in this 

I mainly agree with him, except that the upper portion is evidently a 

passage formation between the Cambrian and Silurian (Ordovician). 

On lithologic and stratigraphic evidence the line would be drawn at the 

summit ot the red shale; on paleontologic evidence, as furnished by the 

Graptolites, I would include the upper portion of the Sillery red and 

green shales in the Silurian (Ordovician), as I think they are above the 

typical Potsdam zone of America.1

The strata doubtfully referred to the Cambrian group between Quebec and Cape Eosier, on the south shore of the St. Lawrence Eiver, have 

already been described in the notice of the work of Mr. James Bichardson, reported upon by him in 1870. (Ante., pp. 118, 119.) As they 

may or may not beof Cambrian age, no further description will be given.

The.strata referred to the Cambrian on the western side of the Sutton Mountain anticlinal, or the belt extending southeasterly from Quebec to the Vermont boundary, are described by Drs. Selwyn and Ells 

as consisting for the most part of hard quartzites interstratified with 

mica-schists and black slates. All of this series, as described by them 

is unconformably overlapped by the Sillery red slates, conglomerates, 

and sandstones. Limited outcrops of grayish subcrystalline limestones 

are found occasionally in association with the black slates and quartzites.

The volcanic portion of the Cambrian, or group No. 2 of Dr. Selwyn,2 

presents a great variety of crystalline, subcrystalline, and altered rocks, 

including "coarse, thick-bedded, feldspathic, chloritic, epidotic, and 

quartzose sandstones, red, gray, and greenish siliceous slates and argillites, great masses of dioritic, epidotic and serpentinous breccias, and 

agglomerates, diorites, dolorites, and amygdaloides, holding copper ore; 

serpentines, felsites, and some fine-grained granitic and gneissic rocks, 

also crystalline dolomites and calcites. Much of the division, especially 

on the southeastern side of the axis, is locally made up of altered volcanic products, both intrusive and interstratified, the latter being clearly 

of contemporaneous origin with the associated sandstones and slates."

As far as known this zone has not afforded any fossils. Dr. Selwyn

1 Walcott, C. D.: A review of Dr. R. "W. Ells's second report ou the geology of a portion of the Province of Quebec, with additional notes on the " Quebec group." Am. Jour. Sci., 3d ser., vol.39,1890, 

p. 113.

2 Report of observations on the stratigraphy of the Quebec group and the older crystalline rocks of 

Canada. Geol. Surv. Canada: Report of progress, 1877-1878,1879, pp. 6A, 6A.
WALCOTT.] SUMMARY NEW JEESEY. 287

thinks that if found they would indicate a lower horizon than the Levis 

formation, probably not far removed from the St. John group and Atlantic Coast series of Nova Scotia, or Lower Cambrian. Details of the 

lithologic and stratigraphic features of the strata referred to the Cambrian and their geographic distribution may be found in the reports 

by Dr. Ells on the Eastern Townships of the Province of Quebec.1

SOUTHERN APPALACHIAN DISTRICT.

The Southern Appalachian District includes the outcrops of strata 

referred to formations of the Cambrian group in northern and central 

New Jersey, southeastern and southern central Pennsylvania, western 

Maryland, Virginia, and North Carolina, eastern Tennessee, northwestern Georgia, and northeastern Alabama.

NEW JERSEY.

As far as known the rocks of New Jersey referred to the Cambrian 

are found in the northern central portion as outcrops of a norifossiliferous sandstone resting upon Archeau gneiss and subjacent to a Magnesian limestone that has been referred to the Calciferous zone of the 

New York section. The greatest thickness assigned to it is 20 feet.

The correlation with the Potsdam sandstone of New York is based 

entirely upon the lithologic characters of the sandstone and its stra.tigraphic position. There is no positive evidence of its being the equivalent of the Potsdam sandstone of New York. It may be Lower, Middle, or Upper Cambrian, and possibly of Calciferous age. From the 

stratigraphic conditions to the north and south it will probably be 

found to be of Lower Camhjian age, or the equivalent of the " Granular Quartz " of New York and Vermont. The lower portion of the 

limestone series may be of Cambrian age, as in Dutchess County, 

New York.

Among the papers presented to the Geological Society of America 

at its second annual meeting, December 31, 1890, was one by Prof. 

Frank L. Nason on*"The post-Archean Age of the White limestones 

of Sussex County, New Jersey," in which he describes the discovery of 

the Olenellus fauna in the lower Primal sandstone of Kogers that rests 

uncouformably upon the pre-Cambrian rocks. He said also that fossils 

(Obolella or Lingulella) extended up into the superjacent limestone.

In Prof. Nason's collection I recognized Olenellus thompsoni, Obolella 

or Lingulella sp.?, and the cast of a coral-like organism that is probably a species of Ethmophyllum. These were found at Hardistonville and Franklin Furnace, Sussex County, New Jersey.

1 Second report on the geology of a portion of the Province of Quebec. Geol. Surv. Canada, new 

sorioa. vol. 3, 1889, pp. 1K-120K.

Keport on the geology of a portion of the Eastern Townships of Quebec. Geol. Surv. Canada, 188C, 

new ser., vol. 2,1887, pp. 1J-70J. .
288 THE CAMBRIAN. [BULL. 81.

DELAWARE.

The outcrop of the sandstone referred to the " Potsdam n in northwesterD Delaware is very limited, and is noted only to indicate its 

occurrence within the limits of the State.1

PENNSYLVANIA.

The rocks referred to the Cambrian System in Pennsylvania by the 

latest authorities include the Primal quartzite of Prof. Eogers; and 

Prof. Lesley is inclined to consider the sandstone and slate of the South 

Mountain proper as of Cambrian age. The line of outcrop of the 

quartzite extends along the boundaries of the various Archean areas 

from the Delaware Eiver ou the northeast, in Bucks, Lehigh, and 

Northampton Counties, southwesterly, with more or less interruption, 

across Berks, Montgomery, Chester, Lancaster, York, and Adams 

Counties, to the Maryland line. Prof. J. P. Lesley's summary is as follows:

The lowest Paleozoic formation in Pennsylvania, No. 1, logically identified with the 

Potsdam sandstone of northern New York, makes its appearance along the edges of 

the limestone No. 2 at the north foot of the Azoic Mountain Range between Bethlehem 

and Reading in Lehigh and Berks Counties; in Mulbaugh Hill, on the Lebanon 

County line ; in Chicques [" Chickis " of Frazer"] Ridge, on the Susquehanna, above 

Columbia; in the Welsh Mountain in northern Chester, and in the North Valley Hill, 

which stretches for 60 miles from the heart, of Lancaster to the Bucks-Montgomery 

county line north of the city of Philadelphia. Its only fossil as yet discovered is a 

Scolithua, but its position next beneath the Calciferous limestone is too well marked 

to admit of doubt. Formerly it entirely covered the mountain districts north and 

south of the Schuylkill River, because it still spreads in sheets upon their sides, and 

in many places makes their summits, lying unconformably upon the gneiss.

The South Mountains proper, which separate Cumberland from York and Franklin from Adams County, do not thus exhibit the fundamental gneiss covered by 

a coating of Potsdam, but are composed of peculiar sandstone and slate strata several thousand feet thick, which occupy the place of the Potsdam in the series, but can 

not certainly be identified with it. They may be considered the equivaleuts of the 

Ocoee and Sewanee strata of east Tennessee. * * * We may consider our South 

Mountain rocks, therefore, those lying north of the turnpike fault, as of Cambrian 

age. 2

The sandstone referred to the Potsdam in Lehigh and Northampton 

Counties is described by Mr. Frederick Prime, jr., as "a hard, compact 

quartzite, of a yellowish color where weathered, and when freshly quarried of a grayish tint. * * * The thickness, where it could be measured, was 21 feet.3 "

The quartzite varies in thickness from 20 to 300 feet, the greater 

thickness being in the " Chickis " section of Lancaster County, where, 

according to Dr. Persifor Frazer, it reaches 300 feet. Southwest of the

1 Chester, Frederick D.: Preliminary notes on the geology of Delaware Laurentian, Paleozoic, and 

Cretaceons areas. Phil. Acad. Sci. Proc., vol. 36, for 1884, pp. 237-259.

* A geological hand atlas of the sixty-seven counties of Pennsylvania, embodying the results of the 

field work of the survey from 1874 to 1884. Second Geol.Surv. Pa.,X, 1885, pp. xvi, xvii.

s Geology of Lehigh and Northampton Counties. Second Geol, Surv. Pa., D3, vol. 1,1883, p. 205.
WALCOTT.1 SUMMARY MARYLAND. 289

Susquehauua River it is difficult to measure its exact thickness, owing 

to its disturbed condition. The characters of the aandstoue appear to 

be very much alike throughout the State, and the only traces of organic 

remains found are the straight, vertical tubes of Scolithus.

Prof. H. D. Rogers referred a series of slates, between the sandstone, 

called Potsdam, and the base of the superjacent limestone to the Primal 

period, but the geologists of the Second Geological Survey consider them 

as belonging to the limestone series. If a comparison be made with the 

Tennessee sections, where the schists and shales between the quartz!to 

and the limestone are characterized by Cambrian fossils, this series of 

schists will certainly be referred to the Cambrian, as it is subjacent to 

the great limestone series and superjaceut to the quartzite. According 

to Prof. Rogers, the highest or Primal newer slate is a greenish and 

bluish talcose argillaceous slate, sometimes very soft and shaly, and 

has a thickness of about 700 feet. Dr. Frazer refers about 1,000 feet of 

"Hydromica schist "to the interval between the quartzite and limestone in York County. 1'

The upper part of the Primal slates does not appear to be developed to 

the northeastward in Lehigh, Northampton, Bucks, Montgomery, Berks, 

and Chester Counties. It first appears with any considerable thickness 

in Lancaster County, near the Susquehanua River, and south of the 

quartzites of the Chickis Hills. From" thence it extends southwesterly, 

across York and Adams Counties, to the Maryland line, increasing in 

thickness in Maryland and Virginia.

As a whole, the Cambrian System in Pennsylvania appears to be represented by the lower quartzite and the superjacent shales and schists 

as originally defined by Prof. Rogers, and it may be that the lower 

portion of the superjacent limestone will be included.

In a letter received from Prof. Lesley, dated May 8, 1890, he says:

Reading Ells's paper and Brainerd & Seely's paper in Bull. Geol. Soc. America, just 

published, with your remarks at the meeting, I naturally reverted to my South Mountain surveys (20 years ago) east of Chambersburgh, Pennsylvania (Fulton and Adanis 

counties), and the strange and powerful impression made on me then by the outcrop 

of a low ridge of purple shales, running from the pike southward, just back (vast) of the 

western mountain ridge. I never saw anything like them, and feel strongly inclined to consider them the Sillery purple shales (Cambrian) of the North. I can't 

liud or remember any description of this outcrop by Frazer. It lies in Ful ton County, 

outside the Adanis County lino.

MARYLAND.

I have been unable to find any detailed account of the rocks referred 

to the Primal series of Prof. Rogers, and have depended upon the general account given by Prof. P. T. Tyson in 1800, in his report as State 

agricultural chemist. His description is short and will be quoted in 

full:

(Primal of Pennsylvania survey.) Potsdam of New York. This division includes: 

(1) A hard sandstone made up of grains of quartz, with occasionally grains of

1 General notes. Sketch ou tho geology of York Comity, Peuusylvaiiui. Am. ljliil. Soc. Proc., vol. 

23,1880, p. 401.

Bull. 81 19
290 THE CAMBEIAN. [BULL.81.

feldspar and kaolin. The siliceous cement seems to have completely filled up the 

interstices between the grains so as to give a firm compact structure to the rock. 

Portions of this rock seem to have been subjected to such changes as to render it 

doubtful whether it should not bo considered a granular quartz and be classed among 

the metamorphic rocks. Vegetable life seems to have commenced at the period of 

the formation of this rock, because it contains fossilized stems of plants.

(2) A slate varying in color from gray to brownish and greenish. It is ranked as 

an argillite, but portions of it assume a marked talcose appearance, especially in the 

Catoctin Mountain and in parts of Middletown Valley, where it has been much disturbed and altered by proximity to intrusive rocks. These last consist of amphibolites (trap), porphyries, amygdaloid, serpentine, and epidote. This last-named rock is 

extensively developed both in large masses and intercalated between the slates,-and 

has largely contributed to produce the highly fertile soils of Middletowu Valley.

Approximate measurements of the thickness of these strata have been made in 

New York and Pennsylvania, but I have not as yet been able to obtain reliable information upon this point in our State.1

From this description and the geographic distribution of the Primal 

series as indicated on the accompanying map, it is evident that the 

quartzite of South Mountain, Pennsylvania, extends nearly north and 

south, across Maryland, and that the slates and associated eruptive 

rocks which form the main mass of South Mountain are included by 

Prof. Tyson in the Primal series. In the sections of these slates and 

accompanying rocks in Virginia they are recognized as pre-Cainbrian, 

and it is very probable that those of Maryland and north into South 

Mountain of Pennsylvania are also of pre-Cambrian age. The presence of the upper Primal slate of Rogers between the quartzite and the 

Auroral limestone is not noted by Prof. Tyson. The fossilized stems of 

plants referred to are probably the Scolitbus borings found so abundantly in the sandrock of Pennsylvania and Virginia. If the lower 

portion of the limestone series of Pennsylvania is of Cambrian age it 

is probable that the extension into Maryland is the same.

VIRGINIA.

Prof. William B. Eogers's description of the geographic distribution, 

stratigraphic position, and character of the strata that he referred to the 

Primal series, has been proved to be in a large measure essentially correct by the observations of geologists who have more recently studied 

the formations referred to the Cambrian group. He described formation No. 1 as consisting in the most part of a close-grained white or 

light gray sandstone, in some places containing beds of a rather coarse 

conglomerate of white siliceous pebbles. Near the bottom, in many 

instances, a brownish slaty sandstone occurs, alternating with the former, whilst toward the top or approaching the next formation the sandstone passes into reddish and brownish and olive-colored argillaceous 

slates. As far as known to him in his earlier work the formation in 

Virginia was exclusively confined to the western slope of the Blue 

Ridge and the narrow belt of rugged hills and mountains extending

1 Tyson, Phillip T.: First report of the State agricultural chemist of Maryland. Annapolis, I860, 

pp. 34,35.
VVALCOTT.] SUMMARY VIRGINIA. 291

thence to the commencement of the Valley limestone.1 At some later 

date, however, he discovered a small outcrop of the Primal series on 

the eastern slope of the Blue Eidge, in Kockbridge County, and drew 

it in on section 9 of the plates of sections published in connection with 

" The Virginias " in 1884. The Primal sandstones and shales are represented as occupying a narrow, deep basin on the eastern slope of the 

Archean rocks of the Blue Eidge. In this beautiful series of illustrations the twenty sections crossing the Primal series at subequal distances from the Potomac Eiver to the Tennessee line illustrate very 

fully Prof. Eogers's interpretation of th« geological structure, character, and thickness of strata forming ths Primal series.

Prof. W. M. Fontaiue in 1875 supplemented the work of Prof. Eogers 

by a detailed description of the sections of the " Primordial" strata at 

Balcony Falls in Eockbridge County, Eockfish Gap in Augusta County, 

and at Harper's Ferry on the Potomac. He concludes that the entire 

thickness of the Primordial strata at Harper's Ferry can not be much 

over 1,000 feet, and that they are composed of slaty rocks, similar to 

the variety of the lowest slate seen at Eockfish Gap, and a sandstone 

which much resembles some of the quartzites of the .'ower strata of the 

same locality. The section differs from that of Eockfish Gap and Balcony Falls in the absence of the coarser materials and the succession 

of shales and sandstones, with the subjacent conglomerate that rest on 

the Archean. The lower argillites, forming the main portion of the 

ridge and which Prof. Eogers included in his Primal series iu section 

No. 2 accompanying " The Virginias," Prof. Foutaiue refers to the 

Archean; whether of Laurentian or Huronian age, he does not undertake to decide.2

At the second annual meeting of the Geological Society of America, 

at Washington, D. C., December 31, 1890, a paper was read by Messrs. 

H. K. Geiger and Arthur Keith on the structure of tbc Blue Eidge 

near Harper's Ferry.

Several sections, taken on both the north and south sides of the 

Potomac Eiver, show that the geologic succession at the base is a 

limestone upon which rests a series of shales, subjacent to a quartzite 

which corresponds to the Medina sandstone of the sections farther to 

tne north and south. This section is the one described by Prof. Eogers 

as an overturned section, the quartzite corresponding to the primal 

quartzite of the Pennsylvania section, its present position being 

accounted for by the complete overturning, thus reversing the section. 

The authors of the paper mentioned conclude that the succession is a 

normal one from the pre-Paleozoic rocks through the limestone and

1 Second report of the progress of the gelogical survey of the State of Virginia for the year 1837. 

Richmond, 1838, pp. 14,15.

Geology of the Virginias, 1884, pp. 167-169.

lloport of the progress of tlio geological survey of Virginia for 1838 (Richmond, 1839) pp. 6,9-12. 

Geology of the Virginias, N. Y., 1884, pp. 197,198,203-209.

2 0n tho Primordial strata of Virgiuia. Aia. Jour. Sci., 3d ser., vol. 9,1875, p. 425.
THE CAMBRIAN. [BULL. 81.

shale to the sandstone. The basal limestone is of Calciferous ChazyTrentou age; the shales then would correspond to the Lorraine series, 

and the sandstone to the Medina series of the New York section. As 

as far known this is the only break in the continuity of the outcrops 

of the " Granular Quartz," where a quartzite is present, from central 

Vermont to Alabama. 1

At Uockfish Gap the massivechloritic argillites, that form the mass 

of the Blue Bidge, are shown in unconformable contact with the lowest 

Primordial strata. The Archean argillites are firm and hard, of a dark 

greenish color, and present a strong contrast to the first stratum of the 

Primordial rocks, the line of junction being strongly defined. Summarized, Prof. Fontaine's description of the section is as follows, beginning at the base: 2

Poet.

(1) Very thinly laminated slates or shales ................................... 300

(2) Ou the side next to (1), the layers of this rock in color, do not differ much 

from (1), but are thicker than the preceding .slates, aiid more sandy. The 

bedding thickens, and the amount of siliceous matter increases to the 

west, until a fine-grained white kaolin sandstone is the result .......... 75

(3) Conglomerate of brownish-red color, in massive layers from 5 to 6 feet 

thick, with thin seams of shaly matter between several of the layers. 

The coarser materials are rounded grains of quartz of the size of-a garden 

pea and under ; inclosures of angular fragments of the slates of the Blue 

Ridge are not rare .................................................... GO

(4) This is a partially concealed interval of 200 feet in which the rocks are, 

when seen, kaolin shales and kaolin sandstone, principally the former. 

To the Avest of this is a hand of kaolin sandstone, with layers of cellular, 

much indurated quartzite, and some subordinate beds of an indurated, 

gray, coarse sandstone. This series contains one bed of the gray sandstone 20 feet thick. Thickness 420 feet or including the partly concealed band........................................................... 020

(5) The first rock in this series is a highly indurated gray sandstone, the type 

of the beds above mentioned as forming occasional layers in No. (4). It 

is of a dark gray color, and composed of coarse grains which by nietamorphic action are changed to a nearly compact texture. The thickness of the sandstone is 50 feet. A band of diorite 20 foot thick interrupts the section, next to which is a baud of bluish gray, coarse sliales, 

75 feet wide; a partially concealed interval of 300 feet, occupied by 

similar rocks; then for 200 feet, several alternations of the same shales 

with bluish argillaceous sandstones. In these a layer 6 feet wide of red 

argillaceous hematite is found. Then a second band of diorite 12 feet 

wide, resembling in all respects the first.

(C) The bods of No. (5) which are^niostly sandy shales, and are rather thicklybedded in layers of from 1 to several feet, are succeeded by a band of 

very thinly-laminated, firm olive slates or shales, having a total thickness of.......................................... .. ............. 300

Indurated brown sandstone, with some chloiite.......................... 30

Interval of concealed rock................................. .............. 100

Alternations of brownish argillaceous sandstones with greenish shaly beds. 150 

Very finely fissile, pink-colored slaty shales, which weather purplish-red.. 200 

Then for 100 feet a. bluish shale is found ................. ................ 100

880

»]iull.Gool. Sue. Am., vol. 2, 1891,pp. 1&5-1M. 2Ain. Jour. Soi., 3d aor., vol. 1), 1875, pp. 410-121.
WALCOTT.I SUMMARY VIRGINIA. 293

Feet.

The two last series of beds, 5 and 6, appear to bo the equivalent of No. 

(9) of tlio Balcony Falls section. Their combined thickness is abont 1,450 

feet, that is, provided no reduplication from folding occurs. This is 

possible, though not probable, I think.

(7) "The strata now to be described are the equivalent of the Potsdam sandstone, and resemble No. (10) at Balcony Falls in their almost total freedom from iron and other coloring matters. * * * The system hero 

consists of a vast number of thin layers, in which \vo may distinguish 

three classes of rock: (a) A shale pale gray to bluish gray when fresh, 

composed almost entirely of kaolin, and occurring in thin plates. (Z») 

This is associated with a very fine grained kaolin sandstone, the quartz 

grains being now perceptible to the naked eye. * * * (c) A kaolin 

sandstone of moderately fine grain, often with a thickness of several 

feet in the individual layers. The quartz grains are mixed with an equal 

amount of kaolin ............................................... ........ 300

"The beds last described have a thickness of 300 feet, and are succeeded by a partially concealed interval, in which 50 feet of a similar 

rock are shown." The strata between this point and the Auroral limestone are largely concealed.

The section as studied at Balcony Falls by Prof. Fontaine is as follows: 1

Foot,.

(1) Unbodded quartzite, with crystals of feldspar............................ 120

(2) Brown, crumbling, argillaceous rocks or sandy shalo, conglomerate in its

upper portion......................................................... 40

(3) Brown, decomposing, thinly laminated and contorted shalfl............... 10

(4) Conglomerate, 1 i Ice the n pper portion of (2).............................. 20

(5) Shales, like (3).......................................................... 12

((i) Conglomerate,like (4).................................... ............... 15

(7) Crumbling, brownish shales, passing in the upper portion into argillaceous

sandstones of the same hue and texture................................ 200

(8) Massively bedded, coarse white quartz! te (apparently Rogers's typical

No. 1) ............................. .................................. 500

Up to this point the rocks are well exposed in the cliffs which closely 

border the canal. Proceeding west across the strike, we next encounter a series that forms No. (9).

(9) Thinly laminated, gray and reddish shales. Probable thickness...... _. GOO

(10) Alternating beds of quartzito and kaolin shales. Probable thickness.... 700

(11) The first rock seen next to the mountain is thinly laminated, fragile shale, 

of yellowish and reddish hues not fully exposed. Next, to the west, wo 

have bluish calcareous slate, and slaty limestone, 50 feet. Then very 

thinly laminated, firm, deep red slates, 60 feet. Next a similar slate of 

blue color, 15 feet. Then a bed of dark blue, hard, and dense limestone, 

used for cement, 13 foot. Then thinly laminated red slates, 20 feet. 

Then coarser and thicker bedded blue slates, 40 feet. Lastly, a coarse, 

rough, massive, siliceous limestone, 40 feet ..........................+. 238

2,455

Tie compares the Balcony Falls section with that of Eockfish Gap, 

stating that the thickness of Nos. 5 and 6 in the latter section is much 

greater than that estimated for their equivalent, No. 9 in the Balcony

'Am. Jour. Sci., 3d sor., vol. 9,1875, pp. 3C3-3C5.
294 THE CAMBRIAN. [DULL.81.

Falls section, showing that the proportion of shaly matter in the entire 

group at Rockfish Gap has greatly increased. 1

In summing up the physical characters of the sections as described, 

he says:

It will be seen from the above notes that in Virginia we have below the calciferous 

limestones a great development of sandstones, shales, and conglomerates, which 

attain in the middle portion of the State a thickness of over 2,000 feet, and increase 

in the proportion of coarse materials to the southwest. They probably attain greater 

thickness in that quarter, while to tbe northeast the amount of sediment diminishes, 

and tho proportion of line matter increased. This change is plainly due to the 

increasing development to the southwest of the sj enitic rocks which.formed the shores 

of tho ancient seas and to tbe greater violence in that direction of disturbing forces. 

Tho Potsdam sandstone forms one of the upper members of this group. Much further 

study of these strata is required to settle the question whether tbe entire series is a 

great expansion of the Potsdam or whether divisions may be made corresponding to 

other epochs. The fact that at Rockfish Gap, and to the southwest, a great body of 

ferruginous slaty shales separates the lower highly siliceous and altered, sandstones 

from the upper Kaolin sandstones of probable Potsdam age, seems to indicate a change 

in the conditions of sedimentation sufficient to justify such a division, in which the 

Acadian strata may be found.2

With the single exception of a Scolitkus, no fossils have been found 

in these rocks which would indicate their age.

In 1883 Prof. Fontaine supplemented his detailed description of the 

sections by a synoptic description, embracing the general character of 

all the formations that he considered belonging to the Primordial series.3 

Beginning with the base of the Primordial he recognized six divisions 

as follows:

Feet.

1. Lower Primordial conglomerate......................... 0 to 30

2. Lower gray shales andflags............................. 500

3. Red shales and flags ............................... ...... 400

4. Upper gray shales and flags............................. (iOO

5. Potsdam quartzite...................................... 350

6. Ferriferous shales ...................................... 500

2.380

The description of the various formations is so clear and full that I 

quote them:

(1) Lower Primordial conglomerate. I would confine this appellation to'the lowest 

conglomerate that forms the base of the'Primordial where it is present, excluding tho 

conglomerate bands that follow higher up, but are separated from the basal conglomerate by shale and slate. * * * This member, thus limited, I have not seen at all 

the places where the junction of the Primordial with tho Azoic is exposed. * * *

The conglomerate now in question is of special importance, since, when it is found, 

we may be sure that we have the true base of the Primordial. I have never seen it 

without finding the Azoic rocks immediately under it. It consists of a finer matrix 

that is shaly or slaty in texture, in which particles, angular or rounded in shape, 

of the Azoic strata are imbedded. The lithological character of the pebbles varies

'Op. cit.,p.421. 

2 0p.cit.,p.424.

3 Notes on the mineral deposits at certain localities on tho western part of the Blue Kidge. The 

Virginias, vol. 4,1883, pp. 22,42-44.
WAT.COTT.] SUMMARY VIRGINIA. 295

with the nature of the adjoining Azoic. To the south they are more commonly composed of gneissoid rock, but to the north the Huroiiian schists furnish the material. * * *

In the more southerly portions of the belt a good deal of partly decayed feldspar 

may be detected in the finer matrix, but to the north argillaceous material forms 

the cementing matter (p. 22).

(2) Lower Gray Shales and Flags. The lower portion of this member of the Primordial frequently contains bands of conglomerate, composed of quartz pebbles, often 

purplish in color, imbedded in a fine-grained matrix of shale or slate * * * 

(p. 42).

The lower gray shales and flags vary in character more than any other member of 

the Primordial. The predominant rocks are shales, that sometimes become slaty in 

firmness and thinness of lamination, or various more siliceous flaggy rocks that range 

from purely argillaceous shales, through argillaceous sandstones, into massive and 

highly siliceous quartzites. These latter have the character described above. The 

predominant color is gray, but reddish, yellowish, or purplish and greenish colors 

sometimes occur.

Some of the grayish white, argillaceous strata form a species of claystoue that 

weathers to a sorfc of kaolin. For the sake of distinction these may be called kaolin 

flags. This kind of rock is much more common in the member next under the Potsdam quartzite. The conglomerates occurring in the lower part of this member have 

been already described.

The general features of the qnartzite members of this group have been already sufficiently discussed. Towards the southern portion of the belt, they attain groat dimensions. This is especially true of the space between the southern border of Augusta 

County and Balcony Falls. At this latter place a quarfczite formation, occurs about 

150 feet above the base of the Primordial, forming the Balcony Rock. It lies in huge 

beds of a highly siliceous character, and is not less than 250 feet thick. Here the 

massive character of the beds has proven tod the cracking and smashing, accompanied 

with the infiltration of silica, so often neon in the smaller beds of quarfczite at this 

horizon in other places; otherwise tlio character is as given above for the lower 

quartettes. I have never seen any casts of Scolithus borings in these quartzites. The 

great quarfczite at Balcony Falls disappears almost entirely in the northern portion 

of the belt, its place being taken by minor beds of quartzito, and by shales and flags. 

Tlio subdivision of the Primordial bods now beiug described forms the lower portion 

of the Primal older slates of the brothers Rogers.

(3) lied Shales and Flags. This also is quite a variable group, and it changes its 

character very materially as wo go south. In the northern portion of the belt, as far 

as Mount Torrey, the greater portion of this group is composed 'of a fine-grained, 

very.thinly laminated, and tender slate. When fresh this rock has a steel gray color 

and pearly or nacreous luster, but on weathering many portions become deep blood 

red in color. Some of the lower and upper portions become yellow, but rod is the 

predominant color from weathering. Some bands have small pebbles of the size of 

bird shot graduating into sand. Some of the red and yellow colors may be original 

and not duo to weathering. This can not be decided, as all the exposures seen were 

much weathered. This member, in its northern exposures, is often affected by faults 

that cause it to extend over greater breadths than it could occupy in virtue of its 

thickness. Quartz veins occur in it, having the nature of fissure veins. Bands of 

this slate are impregnated with more or less specular iron, and this is the highest 

member of the Primordial that shows iron in the specular form. Some greenish, 

much indurated quartzite occurs in this member. This group to the south becomes 

more siliceous and the amount of red coloring matter diminished.

At Big Mary Creek the slaty character is nearly lost and the amount of red matter 

is much less. The strata are now chiefly rather siliceous gray flags, ami this character ia maintained to Balcony Falls; there the rocks at this horizon ure nearly all
296 THE CAMBRIAN. [BULL.81.

flaggy and gray in color; some reddish and brownish beds, however, are found. This 

change to a more siliceous nature is accompanied by a great increase in the accompanying quartzites. These strata everywhere, owing to their comparatively greater 

capacity for yielding to strains, have suffered much from contortions and minor 

faults.

(4) Upper Gray SJiales and Flags. This group, as the name implies, is somewhat 

like No. 2, but in it the conglomerates and specular ledges are wanting and the 

amount of quartzite is usually much less. Owing to the brittleness of the material 

of the beds and the ease with which many of them yield to crushing, portions of the 

strata are often found crushed to loose fragments. In the fractured and crushed portions important deposits of Uinonite are sometimes found that are evidently produced 

by the concentrating action of percolating waters. The reddish and brownish rocks 

found in No. 2 are also wanting hero. The predominant rocks are shales and flags, 

usually all highly argillaceous, and when fresh of a gray or greenish gray color, but 

on weathering apt to assume a grayish white color. Towards the top quartzite ledges 

are intorstratified with these and cause a gradual passage into the Potsdam qnartzito. In some places the amount of quartzito here is very large and should properly 

bo counted as a portion of the Potsdam member of the Primordial. Perhaps the predominant rock is a gray shale that resembles a hardened mndstone and which graduates into a sandy shale. This rock often decays to a pure white clay, and no doubt 

furnishes the material for the pure potter's clay sometimes found immediately west 

of the Blue Ridge. These strata for the sake of distinction may be called kaolin 

shales or flags.

(5) Potsdam Quartzite. The members of the Primordial below this, so far as observed by us, show no indications of the former existence of life. This portion of the 

formation, however, shows in some beds numerous casts of Scolithus borings, some 

of which are remarkably long, being visible for at least 3 feet. The brothers Rogers 

considered this member as identical with the Potsdam sandstone of New York. This 

portion of the Primordial is more constant in lithological character than the subdivisions that underlie it. Quartzite is always the predominant rock in it, the remaining portions being mostly composed of the kaolin shales and flags. To the south, 

and especially in the interval from Mount Torroy to Buena Vista furnace, the quartzite is very massive and siliceous, composing nearly all of the rock at this horizon. 

The material is more properly called a quartzite than a sandstone. The upper and 

lower portions are often flaggy, and cause a passage into the underlying and overlying shales and flags. So far as observed, these quartzitcs are never conglomeratic, 

and they are free from the infiltrations of silica, the diffused chlorito, and other'characters that mark the lower quartzites. Near the junction of this member with No. 

4, the strata are often crushed, the crushed band, holding important deposits of a 

dark limonite. The Quartzite members of this subdivision are sometimes broken up 

and crushed, forming a curious band of breccia, cemented by iron or manganese. 

Sometimes workable deposits of Hmouito are found in these disturbed portions.

(6) Ferrifei'ous shales. It might be .a question whether these shales ought not rather 

to be counted with the Calciferons group. It is certain that there seems to be a 

gradual passage from the shales into the pure Magnesian and Siliceous limestones, 

that correspond to the Calciferons sandstones of New York. No fossils are found to 

settle the matter, and it seems best to draw the dividing line at the first marked 

change in the lithological character of the strata. This change occurs with the lowest limestone beds, that usually occur interstratified with reddish and yellowish 

shales.

The Ferriferous shale group is noteworthy for containing throughout it deposits of 

limonite which are often suited for the manufacture of a neutral iron. These deposits seem to be of concretionary origin, formed by the decay of the shales which contain the iron in a diffused form, probably, for the most part, as a carbonate, but 

sometimes as pyrite. These ores are consequently usually imbedded in clay. They
WAI.COTT.) SUMMARY VIRGINIA. 297

assume tho form of lenticular masses, usually built up of concretionary forma. These 

ores are unlike those found iu and under the Potsdam sandstone, and not rarely are 

mingled with oxide of manganese or associated wi th it, forming ferro-manganeso. In 

the same shales, occurring under conditions similar 1o the iron and formed in like 

manner, we find, not rarely, deposits of quite pure manganese oxide. This is always 

in the form of Psilomelane or hard manganese.

The lowest of tho strata of this group have tho character of kaolin shales and 

Hags. They graduate insensibly into the Potsdam quartzite member. In ascending 

they become purely argillaceous shales, generally of lead, or bluish gray color, when 

fresh. With these, moreover, occur strata yellowish-reddish in color, the red often 

assuming a pinkish shade. Towards tho top, ledges of pretty firm pure purplish 

shales and Hags are found that are sometimes of the nature of fine-grained sandstone. 

The shales towards the top are often calcareous, and graduate into tho impure limestone with which tho Caloiforous group may be assumed to begin.

We thus have in tho Primordial formation, in tho belt now being described, at 

least throe horizons of iron ore. The lower strata contain specular iron ore usually 

of low grade, tho middle portions, extending as far as the Potsdam quart/ite, containing limonites, either impregnating definite strata, or filling what were once fissured and crushed bands. Hence all of these usually appear in massive or rocky outcrops. Finally, in the Ferriferous shales, we have interrupted deposits of liinonito, 

inclosed in clay and often mixed with manganese. (No. 12885, U. S. G. S. Library.) 1

The Balcony Falls section has also been studied by J. L. and IT. J). 

Campbell with a slightly varying result. As measured by Prof. J. L. 

Campbell the section is as follows:

Ff.et.

1. Conglomerates ............................ ............... 50

2. Sandstones...... ............................. ............. 350

3. Slates.................................... ................ (500

4. Sandstones (thickness not given).

5. Slat«-.8...1.......... ...................................... 180

(i. Scolithus sandstone ...................................... 340

7. Slialos..................................... .............. 000

Total......................................................... 2,120

A comparison of this with the secfJons measured by Pro£ Fontainc, 

in 1879, shows essentially the same succession of strata, although differing materially in the thickness of the various divisions based on the 

character of the rocks. Subsequently, Prof. Campbell added to the 

preexistent information of the section at Balcony Falls, by showing 

that the primal series is present upon the southeastern slope of the 

Blue Eidge, a short distance north of the James river. Tins was followed by a paper on the Snowdon slate quarries, by himself and his 

son, in which it is said that the sandstones are penetrated with Scolithus and dip beneath the Snowdon rooting-slate quarries. 2 An accompanying ideal section, crossing the Blue Eidge 3 miles north of 

James Eiver Gap, represents the Primal series at the summit dipping 

to the westward and on the eastern slope dipping at a high angle to 

the eastward and resting unconformably upon the Archean gneiss. 3

1 Op. cifc., p. 43.

2 Tho Snowdon slnto quarries. Tho Virginias, vol. 5,1884, pp. 162,1(53.

3 Op. cit., p. 170.
298 THE CAMBRIAN. [BULL fil.

Prof. J. L. Campbell concludes, from the structure, that this portion 

of the Blue Eidge has been formerly spanned by a grand arch or series 

of arches of Cambrian strata, upturned, perhaps, at the time of their 

upheaval. 1

In 1885 Mr. H. D. Campbell published a more detailed section of the 

Blue Eidge at Balcony Falls, to illustrate the view that the Blue Eidge 

at this point is a portion of an anticlinal fold, over which the Cambrian 

strata formerly extended from the west to the east, forming a synclinal 

basin on the western side of the Bine Eidge. He described the Cambrian section at Balcony Falls as follows:

Foot.

1. Conglomerate.............................................. 120

2. Sandstone................................................... 360

3. Slates.................... .................................. 500

4. Hard sandstone............................................. 150

5. Slates................................................ ...... 700

6. Sandstone.................................................. 90

7. Slates...................................................... 120

8. Scolitb.ua sandstone ........................................ 350

Total................................................. 2,390

He farther states that, away from the river some distance, there is 

about 600 feet more of sandstone and friable slate before reaching the 

limit of the Potsdam formation. 2 This gives a greater thickness to the 

Cambrian section of Balcony Falls than that measured by either Prof. 

J. L. Campbell or Prof. Fontaine.

The next complete description of the Cambrian in the southwestern 

portion of the State is that of Prof. J. J. Stevenson, in his account of 

a reconnaisance of Bland, Gyles, Wythe, and portions of Pulasld and 

Montgomery Counties. On the map accompanying the paper, the geographic distribution of the Cambrian rocks is shown for Montgomery, 

Pulaski, and Wythe Counties. He includes in the Cambrian the lower 

Knox shales and the Potsdam, stating that the former are probably 

equivalent to the hydromica schists of Pennsylvania and the lower part 

of the Calciferous of New York ; the latter is the Potsdam of New York, 

vastly increased in thickness. 3 The Knox shales are described as being 

reddish, sometimes streaked with white color, usually more or less 

greasy, often talcose-looking on the slipped surfaces. The shales are 

hard enough to form bluffs. The thickness could not well be ascertained, but it can not be less than COO feet.

Tbo Potsdam forms the great mass of Lick Mountain, is the sandstone of Draper 

Mountain, and is found along the southern border of Wythe, Pulaski and Montgomery Counties. The upper beds are alternations of sandstones and shales.

1 Geology of the Blue Ridge near Balcony Falls, Virginia; a modified view. Am. Jour. Sci., 3d ser., 

1884, vol. 28, p. 223.

2 The Potsdam group, east of the Blue Ridge, at Balcony Falls, Virginia. Am. Jour. Sci., 3d ser., 

vol.29,18Sf>, p. 472.

3 A. geological reconnaissance of Bland, Giles, Wytho, and portions of Pnlaski and Montgomery 

Counties of Virginia. Am. Phil. Soc. Proc., vol. 24,1887, pp. 80,87.
SUMMARY TENNESSEE. 299

The base of the series was not observed by Prof. Stevenson, but he 

thinks that the sandstone of Draper Mountain is not less than 2,000 

feet in thickness. The only fossils observed were Scolitlius linearis, on 

Lick Mountain.

InDutchess County, New York, on the north, and in Tennessee on 

the South, the lower portions of the limestones are of Cambrian age. 

Whether the same is true of the arenaceous limestones above the Cambrian shales is one of the problems to be studied in Virginia.

NORTH CAROLINA.

The Cambrian rocks in North Carolina are the extension across the 

border from Tennessee of the Chilhowee series with, perhaps, some of 

tlie Kuox shales. The best section is that along the line of the French 

Broad from. Paint Rock on the State line eastward up the river to tho 

vicinity of Warm Springs. The Paint Rock sandstone apparently is 

the representative of the Chilhowee sandstone, and the shales the Knox 

shales, or Upper Cambrian. The relation of the other portions of the 

section on the French Broad to these formations is, asyet, undetermined.

TENNESSEE.

Ocoee conglomerate. The descriptive details of the Cambrian rocks 

of Tennessee are almost entirely derived from the work of Prof. J. M. 

Safford as published in the " Geology of Tennessee" in 1869. A large 

amount of additional data has been obtained by the geologists of the 

U. S. Geological Survey. At my request Mr. Bailey Willis, chief of 

Appalachian Division of Geology, prepared the following notes upon 

the' geologic position of Prof. Safford's Ocoee formation :

The Appalachian Paleozoic area is bordered on tho eastern side by a belt of elastics 

of vory great thickness, which forms conspicuous ridges between the Archean granites and the calcareous Paleozoic strata. The slates, sandstones, and conglomerates 

of this belt, characterized by lithologic similarities among themselves and distinguished by marked lithologic contrasts from other rocks, fall into a natural group. 

Semimetainorphic, they occupy mineralogically a position between the crystallines 

and tho unaltered sediments. Resting in many localities directly on the Archean 

and containing fragmental granitic minerals, their apparent stratigraphic position 

is al«o intermediate between the Archean and the unaltered sediments. For these 

reasons, and in the absence of fossils, they have boon placed by all the older geologists at the base of tho stratigraphic column. Structural facts sometimes fall in with 

this stratigraphic arrangement, and where they do not faults have been assumed to 

account for the superposition of the supposed older on younger strata.

In Tennessee tho typo localities of these elastics are Chilhowee Mountain and the 

Ocooe gorge, and quartzites of the Chilhowee type, but not in Chilhoweo Mountain, 

have been correctly placed above slates of the Ocoee type by Saffbrd. Your own discovery of fossils in the upper shales of Chilhowee Mountain appears to determine the 

age of all those sediments as Lower Cambrian or pro-Cambrian. But there is an assumption which must be sustained, or the conclusion fails in its broad application. 

That Is, that the natural grouping of these strata by physical characters into a single 

series proves them to be of one period; this may be tho result of similar conditions 

which existed at different periods, and the natural group may include strata of widely
300 THE CAMBRIAN. [BUM.. 81.

separated horizons. The latter is the fact. The Chilhowee formation in Chilhowee 

Mountain has been proved by fossils to be Lower Cambrian, bub ifc is a synclinal 

mass isolated by faults, and the definite determination does not apply beyond its 

limits. It is not connected with the Ocoee area, and the Ocoeo rocks in the type 

locality are so separated from strata of known age, that nothing definite can now be 

asserted as to their correlations. Starrs Mountain, a "Chilhowee" outlier 24 miles 

southwest of Chilhowee Mountain, contains a fossiliferous limestone apparently conformably underlying the quartzite; if further study confirms this apparent relation, 

tlie quartzite is near or above the top of the Lower Silurian. Meadow Creek Mountain and the Big Butt range, extending from 25 to 70 miles east by north from Cliilho\voe Mountain and assigned by Safford to the Chilhowee and Ococe formations, are 

determined on stratigraphic and structural evidence to belong to the Nashville period, 

the last of the Lower Silurian deposits. " Ocooo" strata of Safi'ord, occurring southeast of Chilhovvoe Mountain about Cades, Tuckaleochee, and Weirs Coves, are known 

to belong to the Nashville on evidence of strict structural conformity to the Kuox 

dolomite over three extensive quaqnaversals and through transition beds from the 

dolomite to the slates. The Nashville " Ocoee" strata in this locality and in the Big 

Butt exceed 12,000 in thickness and form some of the highest ranges along the North 

Carolina boundary.

If, .as these facts prove, the great natural group of elastics along the eastern Paleozoic border is the result of conditions repeated in different periods, wo should seek 

sin explanation for recurrence of like conditions, and this is found iu the relative 

extent of subsidence in the Cambrian and Silurian times.

The Cambrian sea transgressed over the granitic continent under such conditions 

that the constituent minerals entered into shore deposits, without complete decomposition; these conditions probably existed in the deep disintegration of the granite, 

as suggested by Pnmpelly. The subsidence ceased during Knox time and the deposition of the Knox was followed by uplift which exposed the dolomite to the waves 

of the Nashville sea. The evidence of this and of subsequent subsidence is found 

in conglomerates of Knox dolomite at the base of and interstratified with the strata 

of the Nashvillo-Ocoee in many localities. The beds associated with those conglomerates are arenaceous shales and sandstones, but higher in the Nashville series conformably stratified with these, and extending to basal conglomerates resting on the 

Archean, are deposits containing granitic fragments like those of the CambrianOcoeo. The stratigraphic and geographic relations leave no doubt that the Nashville was a period of great transgressions beyond the limits of any previous subsidence, and the deposits derived from the granites in the later time wore identical 

with those earlier accumulated from the same source.

The somi-metamorphic character of both Cambrian and Nashvillo-Ocoee strata 

demands explanation which may possibly be found, in their original composition and 

in their common relations to thrust and resistance during Appalachian formation. 

Both aeries of rocks are thin bedded piles, both rest against the unyielding Archean 

masses. Whatever pressure they received they were forced to conform to and they 

appear to have suffered changes of form, which were both mechanical and chemical 

and which were induced by dynamic conditions.

The generalizations herewith submitted are derived from the detailed work of 

Messrs. Arthur Keith and C. Willard Hayes as well as from my own studies and tho 

conclusions as to the age of formations have been reached through mutual cooperation.

Chilhowee sandstone. The lithologic character of the Chilhowee sandstone is given as follows by Prof. Safford:

It is a great group of heavy-bedded sandstones, often dark, but generally weathering 

to a grayish whi te, and containing great beds of whitish quartzose sandstone, or quartzite. Inter stratified with the hoavy-bodded rocks are, at some points, sandy shales, 

and thin ilags, often containing scales of mica. Some of the sandstones are coarse
WALCOTT.J SUMMAEY -TENNESSEE. 301

and approach fine conglomerate. It may be mentioned, too, that not unfroqueutly 

the strata have green grains (gtanconite) disseminated througli them.

The sandstones of this group very often show the worm-holes, and the sandy rods 

within them, belonging to Hull's species ftcolithiia linearis. It is the exception not to 

meet with them. lu addition to these, the surfaces of the strata sometimes show impressions of. fucoids. No other fossils, that I know of, have been found in this horizon 

of Tennessee.

This formation is by no moans as thick as the Ocooe series; yet it has volume 

enough to form conspicuous mountain ridges. It is not easy to determine its thickness; its maximum is not less, however, than 2,000 feet, and it may be considerably 

more. 1

This general description is followed by the detailed description of a 

number of sections. The lithologlc features of this formation are much 

the same in all of its presentations, from Virginia to Georgia.2

Knox sandstone and skate. In the table of geological formations the 

Kuox group is next in order above the Ghilhowee sandstone, aud ita 

basal member is formed by the Knox sandstone,3 The principal rocks 

of the Kuox sandstone are hard shales and thin sandstones, heavier 

sandstones being iuterstratined with these. The heavier sandstones 

are line or coarse grained, sometimes quartzose. They occasionally 

abound in green grains. In the section of Webb's Kidge, near Knoxville, the hard, dark, gray sandstone referred to occurs six times in 

beds from three to ten feet thick, and weathers into a buff, softer material. In general, the included layers vary much in appearance. As 

before stated, beds of dolomite are met with in the division.4

The thickness of these rocks can not be much less than 800 or 1,000 feet. In Wobb'a 

Kidge, whore they are in less force than at many other points, the thickness is 540 

foot.

The strata are often ripple-marked, aud sometimes covered with fucoidal impressions and ridges. Aside from fucoids, I have not met with any fossils in these rocks. 

* # »

It may bo mentioned as a prominent feature of this division, and of the Knox shale 

overlying it that they present shales aud sandstones of many different colors. The 

rocks are pale green, brown, aud red, chestnut-colored, buff, gray, aud other colors. 

Brownish red, greenish, and buif are, perhaps, the prevailing tints. The colors are 

often bright, aud notably agreeable.

Iii reading the description of the Kuox sandstone by Prof. Saifbrd, I 

have failed to find any general or detailed section or description that 

connects the Ghilhowee sandstone aud the Kuox sandstone. Apparently there is not any .section known in which the two are seen in stratigraphic relation to each other. From the character of the section 

and the sedimentation, it may be I/hat the Kuox sandstone is the repre. 

sentative of a portion of the Chilhowee series, the former being the 

oil-shore deposit, while the Chilhowee sandstone accumulated near the 

shore.

The Knox shale is largely a variegated shale, with inter-stratified 

beds of thin layers of blue limestone, which is often oolitic.

1 Geology of Tenuosaoo, pp. 198,10!). 3 Op oil,., p. 158.

* Op. oit., isoa, p. ao3. "OIL «u., j>. m
302 THE CAMBRIAN. [HULL. 81.

»

The calcareous bands in the lower part of the division are not numerous; toward 

the top, they generally become more abundant, increasing as we ascend, until finally 

the shales disappear, and the blue ooliticlitne stoue, and dolomites are the only 

rocks. In this way the shale division runs into the uppermost one.

In the northeastern part of the State the shales, as a division, are not well characterized. As already stated they are much mixed with beds of limestone and dolomites, and lose, in good part, their distinctive features. Moreover, in this region 

there is little oolite rock. A portion of the shale appears to be replaced by a blue 

limestone containing thin clayey seams, which give the surface, especially when 

weathered, a striped appearance. This striped rock occurs, too, further south, its 

place being at the top of the shale.

The thickness of the Knox shale is not easily determined. What is said in reference to the thickness of the strata in Poor Valley * * * applies generally. Wo 

may place it as an approximation at 1,500 or 2,000 feet. 1

Prof. Safiford states that fossils occur in a blue limestone intercalated 

with shales, sometimes quite abundantly, both in the compact and oolitic 

layers. Toward the top of the division and in the blue rocks of the 

succeeding division they are seen at many points. The shales themselves are occasionally fossiliferous. It was his intention to describe 

the species in the appendix of the volume, but we find only a list of 

names, as follows :2

Crepicephalus similis, Safford.

roanensis, Safford.

teunesseensis, Safford. 

Lonchocephalus fecundus, Safford. 

Aguostus arcanus, Safford. 

Lingula prirna ?, Conrad.

A large collection has been made within the last few years at the 

localities from which he obtained his specimens, and from many others 

in Tennessee, that indicate this fauna to be a portion ot the Upper 

Cambrian or Potsdam fauna. The same fauna extends up into the base 

of the limestone for a short distance. The entire doloniitic series is 

referred to the Knox group by Prof. Safford, but I think that the line 

of demarcation must be drawn near the base of the dolomite.

As a whole, the Cambrian group in Tennessee is represented by a 

great series of sandstones at the base, succeeded by a series of shales 

that become more and more calcareous toward the top, where they pass 

into the dolomitic series, forming the base of the Silurian (Ordoviciau) 

system. During the progress of the resurvey of eastern Tennessee by 

the geologists of the U. S. Geological Survey Dr. Cooper Ourtice found 

a few fossils in the shales interbedded in the quartzite of Chilhowee 

Mountain, and in 1889 I found a few specimens in the shale about 20 

feet above the quartzite in the upper shale bed. The study of the fossils collected by Dr. Curtice and myself proves that the Olenellus or 

Lower Cambrian fauna occurs in the shales of the quartzite series of 

Chilhowee Mountain. This fauna, with that found in the upper portion 

of the Kuox shales and the base of the dolomite, gives two distinct

' Op. oit., p. 211. 2 0p.cit.,p.212..
WALCOTT.J SUMMARY GEORGIA. 303

horizons in the Cambriau of Tennessee the Lower Cambrian and the 

Upper Cambrian. Between the two there is an unknown thickness of 

shale, in which fossils have been found sparingly, but not in sufficient 

numbers to determine the presence of the Middle Cambrian fauna. If 

the definition that the base of the Cambrian is to be drawn at the lowest 

horizon in which the Olenellus fauna is found is applied in Tennessee, 

the Chilhowee sandstone will be referred to the Cambrian.

GKORGIA.

The published information relative to the Cambrian rocks of Georgia 

is largely contained in the work of Mr. George Little. It is summed up 

in the compilation prepared for the Department of Agriculture, under 

the direction of Mr. Henderson, as follows :

Acadian. Along the western escarpment of the Cohuttas exist beds of seuiimotaruorphic slates, and conglomerates, apparently of very great thickness. To this formation, in Tennessee, has been given tho name of Ocoee group, from the Ocoee River, 

along which, near the line of Tennessee and Georgia, tho rocks appear to have their 

greatest development, or at least are most prominently displayed.

The group as yet is not known to contain fossils, but has been referred on the ground 

of its supposed stratigraphic relations to the Acadian epoch. A sandstone of several 

hundred feet in thickness is conspicuously displayed in steep ridges or mountains 

skirting the western base of the Cohutta, Pine Log and Allatooua Mountains. This 

is the Chilhowee sandstone of Tennessee, and is believed to be tho equivalent of the 

Potsdam sandstones. In Tennessee, Scolitlius impressions worm holes filled with 

sandy rods, somewhat softer than the body of the rock are mentioned as a common 

characteristic of the sandstone by Prof. Safford, and indicate a probable identity in 

age with the Potsdam sandstone of New York. These markings have not yet, so far 

as known, been observed in this State, but the sandstones are often filled with small 

rounded concretions, that disappear from tho weathered surface, and give much the 

appearance presented by a cross-section of the Scolithus rods in sandstone.

This is succeeded by hard glauconitic shales and glauconilic sandstones, associated 

with siliceous limestones, found in a broad belt of country along the Coosa River, 

and give rise here to what is known as tho Flatwoods. Some portion of the same 

group is found in a belt of country in the eastern portions of Gordon and Bartow and 

the southern part of Murray, and also come to the surface again for a few miles in 

sterile ridges on the western side of Whith'eld County, between Dick's Ridge and 

Chattoogata Mountain. Trilobites are found in some of the shales and limestones, 

and are abundant in the Flatwoods, near Livingston, in Floyd County.

A prominent mineral characteristic is tho common appearance of green sand or 

glauconite in the shales and sandstones, and sometimes in the limestones. This green 

sand) may be found, on close examination, in most of the shales and sandstones, 

and is sufficiently abundant in some to give them a decided green color. * * *

Knox shale. Shales and limestone of an estimated thickness of 3,500 feet. Tho 

shales are more or less calcareous, and are generally of a light green shade of color, 

below the water surface, but weather into a great variety of shades from buff to red, 

blue, green, brown and black, but is most generally some shade of brown. These 

shales exist in all the counties in northwest Georgia except Dade, and are found in a 

number of long valleys, varying from half a mile to 1 or 2 miles in width, constituting 

a large part of the area of cultivated lands in this section of the State. Among 

these are the Oothkalooga Valley of Bartow and Gordon, the Cooehulle and Dogwood 

Valleys of Whitfield, and the Chattooga Valley of Walker and Chattooga. 1

1 ITonrterson, J. T.: Geology (of Georgia). The Commonwealth of Georgia; the country, the people, 

the productions. Atlanta, 1885, pp. 83,84.
304 THE CAMBEIAN. [HULL. 81.

As noticed in the historical review, Mr. McCutchen's estimates of the 

thickness of the formations referred to the Primordial is 8,000 feet, and 

to the Knox shale series 2,400 feet, making a total thickness of 10,400 

feet. The estimates of the author we have just quoted assign to the 

Knox shale a thickness of 3,500 feet, which will give a still greater 

thickness for the total Cambrian section. I think, however, that all 

such estimates must be carefully revised, as the rocks of the Kuox 

shale series are very much disturbed by plications and faulting.

An unpublished section, by 0. Willard Hayes, of the Appalachian Division of the U. S. Geological Survey, extending from Rome, Georgia, 

to Gadsdeii, Alabama, gives the following series, extending from the 

top downward:

Silurian.

<S fl +2 

00 N

<» .rH *J <

O

Knox dolomite.

Thin bedded seamy limestone, sometimes blue and massive.

Yellow shales, calcareous, grading into seamy limestone.

Earthy limestone inter bedded with shales, often wanting ; locally carries nodules of chert.

Yellow shales.

Oolitic limestone; thin beds in light green or yellow 

shales.

Variegated sandy shales, purple, green, brown, etc ....

Thin beds of highly colored sandstone; red, purple, and 

green; show ripple marks and sun cracks. Beds 1 

to 12 inches thick with iutorbedded shales. Maximum thickness shown between Rome, Georgia, and 

Big Cedar Creek ...................................

Green shales, with thin, hard, siliceous beds, ^ to 2 

inches thick, or layers of flat nodules. Maximum 

thickness at Georgia-Alabama line ..................

Fine yellow or brown shales, containing some beds of 

blue limestone......................................

Heavy beds blue, seamy limestone ....................

Yellow or green clay shales, with thin beds of blue 

limestone contorted and iilled with calcite veins. 

Sometimes the shales contain siliceous nodules. AlAvays highly contorted. Cover a large area between 

Home and Gadsdeu, and form the " Flatwoods" of 

Coosa Valley. Thickness not known ; probably not 

less than ...........................................

. 

4,000-5,000.

1,GOO-2,000

1,300-1,800

700-1, 500

1,0004-

3,500

In a recent paper on the valley rocks of northwestern Georgia, Mr. 

Hayes assigns a thickness of 1,COO to 2,000 feet to the Counasauga 

(=Montevallo of Smith) shales; 2,000 to 3,500 leet to the Rome sandstone and Weisner quartzite, and 3,000 feet plus to the Coosa shales.1

In a section at Mount Weisner, Alabama, Mr. Hayes found a quartzite that he considers to correspond to the Eome sandstone. It has a 

thickness of about 800 feet, and is in-the form of lenticular masses of 

white quartzite; sandstone and conglomerate occur at the base and

lrrhe Overtbrust faults of the eouthern Appalachians. Bull. Gool. Soo. America, vol. 2, Fob., 1891, 

p.HS.pU.
SUMMARY ALABAMA. 305

replace a portion of the Koine sandstone. In In.di.a-ri Mountain it is 

much thicker than in Mount; Woisner, and consists of several beds of 

quartzite, with intervening masses of yellow sandy shales.

The fossils collected from the Coosa shales by Dr. Cooper Curtice 

indicate, as studied by me, the Middle Cambrian fauna of the northern 

Appalachian section. The Connasauga shale is correlated by its stratigraphic position with the Knox or Upper Cambrian shales of the Tennessee section. In Mr. Hayes' table the Kome sandstone and Weisner 

quartzite are placed on the same horizon with the Knox sandstone, 

Potsdam or Chilhowee of Smith and Saffbrd. That the correlation by 

Messrs. Smith and Saflbrdof the Weisner quartzite with the Chilhowee 

is probably incorrect is supported by the fact that the fauna of the 

Coosa shales belongs above the Chilhowee sandstone in sections where 

the succession is undisturbed. The Chilhowee sandstone fauna is the 

type of the Lower Cambrian, and the Coosa shale fauna is that of the 

Middle Cambrian.

When the maps of the Paleozoic region of Georgia and Alabama are 

published geologists will have the data for the geographic distribution 

of the Cambrian rocks, and also sections showing the relative position, 

thickness, and the variations in the character of sedimentation from, 

the south to the north as the formations pass to the north into Tennessee.

ALABAMA.

Our knowledge of the Cambrian rocks of Alabama is largely obtained 

from the Keport of Progress for L875. The nomenclature adopted for 

the fossiliferous sedimentary rocks up to the base of the Kuox dolomite, 

by Prof. Satford, in Tennessee, is followed by Prof. E. A. Smith in this 

report. To the Primordial or Cambrian series he assigns the Acadian 

epoch, or the conglomerates and slates corresponding to the typical 

Ocoee section in Tennessee. To the Potsdam epoch he confines the 

Chilhowee sandstone of the Tennessee section. The Knox sandstone 

and Knox shales are referred to tlie Canadian period. The term " Calciferous sandstone" is used as the equivalent of Knox sandstone, and 

" Quebec shales " of the Kuox shales. The section of the Acadian slates 

and conglomerates in Talladega County is considered by Prof. Smith 

typical of this series in Alabama.1 The description is as follows :

Tlie western border of the Metamorphie rocks in Alabama is formed by a belt of 

slates and conglomerates, seaii-nietamorphicin aspect, and of varying width, but porhaps of an average width of six miles. These rocks, which in every respect seem to 

be the exact equivalents of Prof. Safford's Ocoee Slates and Conglomerates, are re- > 

i'erred like them to the Acadian epoch.3

The stratigraphic succession of the beds is not well determined. 

There is a. belt of greenish talcoid, or hydro-mica slate, and a series of 

conglomerates which are sometimes a slaty, arenaceous rock, but often

1 Report of Progress of tho Geological Survey of Alabama for 1875. Montgomery, 1870, pp. 13-17.

2 Op. oil., p. 127.

Bull. 81 20
306 THE CAMBRIAN. I BULL. 81.

quite massive, and made up of lumps of pebbles of opalescent quartz 

and opaque white feldspar, held in a matrix of greenish talcoid matter.

Of the second division, or the Potsdam, it is said:

Next in ascending order, to the slates and conglomerates of the preceding group, 

comes a series of sandstones which form the most conspicuous mountains outside the 

Metamorphic and Acadian areas. The direct superposition of this sandstone upon 

the slates of the Acadian age, I have not seen in Alabama, unless on the eastern edge 

of that belt, the prominent sandstone or quartzite ridge be, as seems quite probable, 

metamorphosed Potsdam sandstone. In the disturbed region of the Kahatchee Hills, 

also, half metamorphosed slates are seen, some of which may belong to the Acadian 

epoch, whilst others are evidently altered Knox shales.

Fine-grained conglomerates, heavy-bedded sandstones, and sandy shales make up 

the great mass of the rocks of this formation. I have noticed, also, occasionally, 

masses of a brownish porous chert, which, from its association with the sandstones, 

seems to be of the same age.

In general, the rocks of this formation are heavy bedded, almost massive, and the 

higher crests of the Potsdam Mountains are usually covered with huge blocks of 

sandstone aud fine-grained conglomerate. In the lower parts of these ranges, sandy 

shales are the prevailing rocks. * * * The most characteristic; markings of the 

rocks of this formation are the sandy rods, caused by the filling in with sand of the 

burrows of a marine worm, Scolithus linearis. Upon the bedding planes of the sandstones, small rounded depressions or dots mark the cross-sections of these Scolithus 

burrows. As yet I have found no other marks of organic origin in strata of this 

horizon. * * *

The nature of the rocks of this group, conglomerates, sandstones, and sandy shales, 

the fossil markings, principally the burrows of marine worms, etc., all point to a seashore origin. 1

From the preceding descriptions, the equivalency of the Chilhowee 

saiidstoue and quartzite with that of Alabama is extremely probable, 

if not certain.

Of the succeeding formation, the Knox sandstone, the following description is given:

The rocks of this group succeed next, in ascending order, the Potsdam sandstone, 

and they are often, no doubt, found resting directly upon that rock. I have not, 

however, often seen them in this position; but much oltener just on the southeast side 

of a fault by which they have been raised to the level of a much higher formation. 

This sandstone is more generally associated with the shales of the next higher group, 

and these with dolomite, so that three groups are usually closely associated geographically as well as lithologically.

A calcareous sandstone, sometimes thick, sometimes thin bedded, is the characteristic Kuox sandstone.

It is associated with hard calcareous shales much like the shales of the next higher 

division. The bedding planes of the sandstone commonly show ripple marks and 

irregular raised markings, which are commonly supposed to be fucoidal impressions. 

The bedding planes are also frequently smooth and shining as if polished. Green 

grains of glauconitic mineral are usually to be seen upon a fresh fracture of the sandstone ; upon weathered surfaces the brown color of hydrated ferric oxide is often 

the result of the decomposition of this mineral. The colors of the Knox sandstone 

are pleasing to the eye, and are gray, greenish brown, buff, chestnut colored, etc. 

Beds of dolomite, impure and chcrty, are found iu the upper part of this formation; 

two such calcareous bods were noticed in the exposure of Kuox sandstone at the 

Jackson shoals aud also at Helena. * * *
 WALCOTT.] SUMMARY ALABAMA. 307

It [Knox sandstone] would naturally be looked for overlying directly the Potsdam 

sandstone of the mountains enumerated iu a previous section; but it is not always 

easy to distinguish it; since, however, these ridges of Potsdam sandstone have a well 

defined belt of Knox shales on their eautcrn and southeastern Hanks, the Knox sandstone, probably in most cases, intervenes between the two. 1

It will be noticed in tbe description given of the Knox sandstone 

that its direct superposition upon the massive u Potsdam " sandstone 

has not been observed. I think that as iu Tennessee the Knox sandstone may be, in part, the equivalent of the sandstone relerred to the 

Potsdam or the Chilhowee sandstone. It is probably the accumulation of sand and shale deposited while the sediments of the more 

massive sandstones were accumulating nearer the coast line.

The Kuox shales rest conformably upon the Knox sandstone series 

and correspond in their description closely with the Knox shales of 

Tennessee. Of these beds Prof. Smith says:

The characteristic rocks of this subdivision of the Kuox group are calcareous shales 

of bright and agreeable colors, usually gray, buff, greenish, brown, chestnut colored, 

and red. The shales are tolerably soft, aud in some portions in weathering, break up 

into small angular pieces resembling shoe pegs. Strata of dark blue limestone, sometimes banded with argillaceous layers, are found, especially iu the upper part of this 

division. The weathering of such limestones brings into relief the bands or stripes 

of argillaceous matter, aud the limestone appears very distinctly banded. Where 

these impurities are not so regularly disposed in layers, but in patches, the prominence given to them by the weathering away of the limestone gives them a striking 

resemblance to half-exposed fossils.

In some places layers of dark colored oolitic limestone have been observed, one of 

the best localities of this peculiar rock beiug at the foot of the mountain at Alpine 

Station in Talladega County.

In the upper part of the division blue limestone layers become more frequent, and 

the transition into the overlying Dolomite is so gradual that a line between them 

lithologically is hard to draw.2

The only instance mentioned to indicate the relations of the so-called 

Potsdam sandstone to the Knox shales is in the following paragraph:

Between the Ladiga Mountain and the hills of Acadian slate iu Calhoun County, 

there are numerous small ridges of Potsdam sandstone, on the Hanks of which the 

Knox shales seein never to be wanting. 3

No fossiliferous strata were observed in this division.

 The distribution of the Cambrian rocks of Alabama is shown on a 

map accompanying Prof. E. A. Smith's outline of.the geology, published 

in 1878. On this map the geographic distribution of both the Cambrian 

and Lower Ordovician rocks is delineated under one color called the 

Silurian. It includes all the formations from the Clinton down to the 

Acadian. Of these formations the Cambrian includes, at the summit, 

the Quebec or Knox shale and Knox dolomite, or at least the lower 

portion of it, and subjacent to this the Calciferous or Kuox sandstone, 

beneath which the Potsdam aud Acadian are placed, the latter forming 

the base of the Paleozoic series.4

1 Op. cit., pp. 17,18. 2 0p. cit.p. 19. 3 0|>. cH.,p.20. 

^Outline of tlio geology of Alabama. Beruey's Handbook ot Alabama, 1878, p. I'M.
308 THE CAMBEIAN. [BULL.81.

In a report on the geology of the Galiaba Coal Field Prof. Eugene A. 

Smith describes the Cambrian rocks as they occur in the Coosa Valley 

of northeastern Alabama. The maximum thickness given is 10,000 

feet in the eastern part of the Coosa Valley. The subdivisions of the 

Cambrian recognized are, in ascending order, as follows: "The Coosa 

shales, the Choccolocco or Montevallo shales, and, iuterbedded with, 

the last named, the Weisuer quartzite. m

The Coosa shales are described as thin-bedded limestones with clay 

seams at the base, and pass above into the Montevallo shales, 

which form a considerable thickness of sandy shales of a great 

variety of colors, such as olive, green, brown, chocolate, yellowish, 

etc. In the upper part of the Montevallo shales beds of blue limestone 

and gray dolomite occur which are difficult to distinguish from similar 

rocks occurring in the snperjaceut dolomite series. Lenticular masses 

of quartzite many hundreds of feet in thickness occur in the Montevallo 

shales. This quartzite is named the Weisner quartzite from its typical 

locality at Weisner Mountain, east of Jacksonville, and is correlated 

with the Chilhowee formation of Prof. Safford in Tennessee.2

From our present knowledge of the formations referred to the Cambrian in Alabama it appears that they are the continuation of those referred to the same group in Georgia and Tennessee, though varying 

somewhat in the local details of sedimentation, thickness of beds, and 

lithologic characters.

The section of Mr. C. Willard Hayes, described under Georgia, embraces much of the Cambrian strata that passes into. Alabama, and 

should be referred to in this connection. (Ante, p. 304.)

KESUME.

For a distance of over 1,200 miles the pre-Cambrian lauds formed the 

eastern boundary of this province during the deposition of the sediments 

of Cambrian time. From below Montreal to the foot of Lake Champlain 

and thence southward to the crossing of the Hudson, below Poughkeepsie, New York, and on across New Jersey, Pennsylvania, Virginia, 

Tennessee, and into Georgia and Alabama, the rocks of this pre-Cauibrian land form an almost continuous outcrop at the present day. The 

Cambrian rocks extend 400 miles farther to the northeast from Quebec 

to the northern portion of the peninsula of Gaspe"; but there is now an 

interval of over 200 miles between the Archean ridges of eastern Quebec 

and the long, narrow Archean axis of the Gaspe peninsula. The exposures of the Cambrian on the coast of Labrador, opposite the Straits 

of Belle Isle, and those of the west shore of Newfoundland, have been 

included in the Atlantic Coast Province, but they are quite as much a

1 Geological structure and description of the valley region adjacent to the Oaliaba Coal Field. Geol, 

Survey of Alabama. Koport oil tlie Caljaba Coal Jfield, pt. n, 1890, p. US, (issubd January, 1891), 

*0p. cit.,pp.l48,14Q.
SUMMARY APPALACHIAN PROVINCE. 309

part of the Appalachian Province by fauna and physical character and 

are considered as a connecting link between the two provinces. The 

Labrador deposits are on the north shore of the Cambrian sea, but 

those of the west shore of Newfoundland arc, in physical character and 

organic remains, the practical continuation of the sediments of the eastern side of the Appalachian Province. If this correlation be made, the 

pre-Cambrian shore line is carried 400 miles farther to the northeast 

and thence to the Straits of Belle Isle, giving a nearly direct line 

of over 2,000 miles that may be included in the Appalachian Province 

with its Canadian extension. Along such a great extent of coast line 

oueexpects to find evidences of varying sedimentation, both in character 

and amount; and an examination of the various geological sections of 

Newfoundland, the river St. Lawrence, Vermont, New York, and south 

along the Appalachian range to Alabama, shows the most marked variation, both on the strike of the strata and in proceeding westward 

from the ancient shore line.

On the Labrador coast the rocks are sandstones followed by more or 

less impure limestone. On the western shore of Newfoundland, over 

1,000 feet of alternating limestones, shales, and quartzites rest conformably upon 600 feet or more of slates. For 375 miles along the south shore 

of the St. Lawrence, from Cape Rosier of G-aspe" to the vicinity of Quebec, the strata referred to the Cambrian consist, according to Mr. James 

Richardson, of quartzite, with intercalated beds of conglomerate holding 

limestone pebbles, the whole forming a series 600 feet in thickness. 

This is superjaceut to 700 feet of gray sandstone, also carrying conglomerate, while beneath this a limestone, with conglomerates and 

bedded sandstones towards the lower portion of the section, extends 

down some 700 feet jnore, giving over 2,000 feet as the entire thickness of 

the section. Owing to the absence of paleoutologic data there is some 

uncertainty in referring all of this series to the Cambrian. In some of 

the pebbles in the conglomerates of the upper portion a number of 

species of the Olenellus fauna were found; but no one of the three great 

divisions of the Cambrian has been distinctly recognized.

In the vicinity of Quebec the stratigraphic succession from below upward consists of a succession of black, green, and gray shales, with hard 

and heavy bands of green, sometimes yellowish white, quartzose sandstones. This is succeeded by greenish, grayish, and blackish, with 

occasionally dark reddish or purplish tinted shales, with a baud of hard 

grayish sandstone. Above the latter bright red shales, with thin greenish or grayish bands, which in places are often calcareous, extend up 

through red, greenish gray, and black shales withinterstratified masses, 

often lenticular, .of greenish and grayish Sillery sandstone. In the upper part of this last series Oboklla pretiosa occurs. A thickness of 

from 5,000 to 6,000 feet is estimated for the Cambrian series, beneath 

the graptolitic shales of Point Levis.

It will be noted of this section that the limestones of western New-
310 THE CAMBRIAN. [BUM. 81.

foundland and the lower portion of the south shore of the St. Lawrence 

are absent, and that the section is composed almost entirely of arenaceous and argillaceous sediments. A limestone conglomerate, near the 

upper portion of the Sillery, contains bo wlders carrying the Olenellus 

fauna, and the Upper Cambrian fauna occurs in the basal conglomerates of the Point Levis, graptolitic.Lower Silurian (Ordovician) shales. 

These bowlders appear to have been derived from a limestone series 

similar to that now found in Labrador and Newfoundland.

The strata referred to the Cambrian, on the western side of the Sutton Mountain anticlinal or the belt extending southwesterly from. Quebec to the Vermont boundary, consist of more or less of the Sillery 

series, as found in the vicinity of Quebec; and, according to Drs. 

Selwyn and Ells, of a subjacent series of hard qnartzite rocks interstrat. 

ifled with mica schist and black slate. The volcanic series, referred to 

the Cambrian in this region, indicates that during earlier Cambrian 

time the volcanic products were deposited contemporaneously with the 

included sandstones and slates, thus giving a phase of sedimentation 

not known elsewhere in the Cambrian of the Appalachian province. 

For this reason and from the fact that there is not any paleontologic 

evidence of the age of this volcanic series I am inclined to think that 

it may belong to some pre-Cainbrian terraue.

Entering the northern end of the valley, between the Green Mountains and the Adirondacks, a sudden change occurs in the sedimentation. At the base, the Olenellus fauna ranges through 1,000 feet of 

magnesian limestone, and for 250 feet higher up in arenaceo-argillaceous shales. More or less arenaceous matter is associated with the 

limestones, and, about 2,000 feet above, a great lenticular mass of limestone occurs in the argillaceous shales, in which a fauna of Upper Cambrian aspect is found. At other localities this fauna occurs in the 

shales themselves and in a brecciated limestone at the same relative 

horizon. As far as known the upper portion of the Cambrian is 

formed of the shales. Proceeding southward and nearer the old coast 

line in Addison County, Vermont, the limestone series is found to 

graduate into the Granular Quartzite or the beach sand. From this 

point this shore deposit is traced without interruption to the Massachusetts boundary; and then, with more or less interruption, to the 

Hudson River below Potighkeepsie, New York. It is taken up again 

in New Jersey, and thence may be followed, with some interruption, 

across Pennsylvania to Maryland, whence it extends as an almost 

continuous formation across Virginia into Eastern Tennessee, and 

thence, with some interruption, into Georgia andAlabama. On all this 

long line it forms the basal member of the Cambrian; and wherever fossils have been found in" it they belong to the Olenellus or Lower Cambrian fauna.

The offshore, or deeper water deposits, are represented by finergrained sandstones, shales, slates, and limestones. In southern Ver-
WALOOTT. ] SUMMARY APPALACHIAN PROVINCE.

mont they form the roofing-slate bel£ that passes into New York, where 

the section comprises some 12,000 feet of shales, slates, and interGoorytctf 'anctMcibtunar

i Jfkstern,NarflnaujJLaM&

S1 A \ LaJjraAor

bedded sandstones, with more or less calcareous matter, either as brec. 

ciated conglomerate or as thin-bedded, intercalated limestones. These 

extend, with some change in their character and regularity of exposure, 

to the Hudson Eiver in Dutchess County. Near Stissingville, in this
312 TEE CAMBRIAN. [BULL.81.

county, the basal sandstone rests upon the pre-Cainbrian and contains 

the Olenellus fauna. A few remains of the latter have also been found in 

the immediate superjacent limestone. The Middle Cambrian and Upper 

Cambrian faunas occur in bedded limestones As the quartzite exposed 

on the eastern side of the limestones of the "Marble Belt" represents 

but a very small portion of the great series of shales, slates, etc., of 

the Cambrian on the western side of the " Marble Belt," it is probable 

that the lower portion of the limestone is of Cambrian age, the same 

as in Dutchess County. This observation also applies to the basal 

limestone in New Jersey and Pennsylvania, where there is very little 

thickness of shales between the basal quartzites and the limestone.1

In central Virginia the lower 1,000 feet of the section is composed of 

an alternation of shales and sandstones, while the upper 1,400 feet is 

nearly all shales and slates, capped at the top by a rough siliceous 

limestone.

In Tennessee the quartzite is developed to a great thickness. -The 

quartzite is of Lower Cambrian age, and the Kuox series of shales 

are characterized in their upper portion by the Upper Cambrian fauna, 

which passes above into the base of the great limestone series. As far 

as known, the conditions in the sedimentation of the Alabama and 

Georgia sections are very much like those of Tennessee.

Briefly summarized, the sediments along the southern portion of the 

coast line are sandstones followed by shales and limestones. More or 

less variation occurs, but, as a whole, the change is gradual as we follow 

the coast line to the north. In central Virginia, 300 miles to the northeast, the argillaceous deposits are more abundant in the lower portion, 

and they form the greater part of the upper series to the base of the 

limestone.

From Virginia northward across Maryland, Pennsylvania, and New 

Jersey, and into New York, the argillaceous material accumulated in 

relatively small proportion to the arenaceous beneath and the calcareous above. How much of the latter is to be referred to the Cambrian, 

is yet undetermined. Our knowledge of the series in Pennsylvania 

and New Jersey is too limited to make an accurate comparison with 

other sections.

In western Massachusetts and Vermont and eastern New York there 

are immediate coast-line deposits and also those of deeper water. 

Along the coast line there was a great accumulation of sand, followed 

by some argillaceous and then calcareous mud. Farther to the west 

the argillaceous material predominates and the arenaceous and calcareous forms but a slight proportion of the great thickness of sediment. To the north these conditions remain until, in northern Vermont, the calcareous matter predominates in the lower portion of the

1 The announcement was made at the December meeting of the Geological Society of America at 

Washington that the Olencllns fanna had been found in the quartzite in New Jersey, and Cambrian 

fossils in the limestones above the quartzite in New Jersey and at Rutland, Vermont.
WALCOTT.J SUMMARY UTAH AND NEVADA. 313

section, and the upper portion is almost entirely argillaceous. In the 

vicinity of Quebec, sandstones and shales make up the section, and 

along the Lower St. Lawrence, shales, sandstones, and limestones.

As a whole, the Appalachian Province is one of varied sedimentation, 

and, from the character of the sediments and determined fossils now 

found in them, they were largely accumulated along a gradually sinking 

coast line. The northern and western shore line exhibits only the contact of the sandstones of the Upper Cambrian that overlap upon the 

pre-Cambrian rocks. Erosion has removed them to a large extent, and 

south of the Adirondacks the western coast line is unknown. (Fig. 2.)

ROCKY MOUNTAIN PROVINCE.

For the purpose of description the area of Cambrian rocks in the 

Kocky Mountain Province includes the Cambrian outcrops of northern 

and western Utah, Nevada, eastern Idaho, the Gallatiu liiver district 

of Montana, and the Canadian extension.

UTAH AND NEVADA.

The Cambrian rocks of Utah and Nevada are considered together, 

owing to their having a common base in the presence of the Oleuellus 

zone, the strata of which rests conformably upon a great series of siliceous and arenaceous shales and sandstones, and massive quartzites. 

In Nevada the section is much more complete and reaches a far greater 

development both in amount of sedimentation and the presence of 

organic remains. The section studied by Messrs. Hague and Walcott 

in the Eureka district may be considered typical of the Cambrian rocks 

of central Nevada. It embraces five formations, all of which are 

described by M.r. Arnold Hague in the abstract of his report on the 

Geology of the Eureka district. 1 .

 The Prospect Mountain quartzite that lies at the base of the scries 

has a thickness of 1,500 feet on Prospect Peak. It is distinctly bedded 

and comformably subjacent to a baud of arenaceous shale, in which the 

Olenellus fauna occurs. It is referred to the Cambrian by Mr. Hague, 

and I am now of the opinion that this should be done, although I have 

held the view that the Olenellus zone should be considered the base of 

the Cambrian, and the Prospect Mountain quartzite I tentatively referred to an Algonkian formation. The subjacent band of arenaceous 

shale is mentioned by Mr. Hague in his report of 1881,2 but not in the 

more complete description of 1882. In the review of the Eureka section 

by Mr. 0. D. Walcott in 1886 this formation is spoken of as follows:

At the summit of 1 the qnartzito becomes more thinly bedded and passes into an 

arenaceous shale which is more or less calcareous and, in its extension northward, is 

replaced by limestone. This belt of shale and limestone is from 100 to 200 feet in 

thickness and carries numerous fragments of fossils, among which we have determined

1 TJ. S. Gool. Snrv., ?d armn.il report, 188.1-'82,3883, pp. 254-259.

'Report (on work in Eureka District). TJ. S. Geol. Surv., 2(1 Ann. Hep., 1880-'81, p. 29, 1882.
314 THE CAMBRIAN. [BULT.SI.

six species, viz, Kulorgina prospectensis, Scenella conula, Olenoidcs quadriceps, Olcnellim 

gilbcrli, 0. iddingsi, Anomocare parvum, and Ptychoparia sp.?1

The second formation is the Prospect Mountain limestone. This is a 

massive limestone crystalline and granular in texture.

Illterstratified in the limestone are irregular beds of shale, lenticular or wedgeshaped bodies, varying greatly in width. Indeed they form a characteristic feature 

in the limestone, which passes readily from massive to shaly beds. Two of the shale 

bands are quite prominent to the north, but are lost to the southward. The thickness of the beds may be taken at 3,050 feet. 2

Formation "No. 1, the arenaceous shale, between the quartzite and the 

limestone on Prospect Peak, is more or less a local formation, but it is 

apparently the zone of Olenellus, and the limestones above are not 

known to be characterized either by Olenellus or the typical forms of 

that fauna. Five hundred feet above the base of the Prospect Mountain limestone there occurs in a band of shale Scenella conula, Agnostus 

interstrictus ? Olenoides quadriceps, Ptyclioparia prospectensis. All but 

the last are closely related to species from the upper beds of the Georgia horizon, in either Vermont or Canada. One other species, Stenotheca elongata, which is found associated with Olenellus thompsoni, 

Protypus senectus, etc., at L'Anse an Loup, is found 2,000 feet higher up 

in the limestone. Another species, Olenoides spinosus, is found in association with species characteristic of a lower horizon than the typical 

Potsdam of Eureka, at Pioche, Nevada." 3

Within a short distance of the summit of this limestone the fauna 

has the general facies of that of the upper Cambrian or Potsdam horizon ; still as a whole it occupies the position of the middle Cambrian 

fauna as the faunas are now classified. That it sustains this view was 

pointed out by Dr. W. 0. Brogger, in his admirable paper on the "Age 

of the Olenellus zone in North .America." 4 He compares the fauna of 

the Prospect Mountain limestone with that of the Paradoxides zone of 

Europe and concludes that with the exception of the lowest part of the 

Olenellus zone it must correspond most nearly to the middle and upper 

part of the Paradoxides deposits of Scandinavia. His conclusions are 

based almost entirely upon the presence of the various species of the 

genus Agnostus. From the results of my studies since 1886,1 am prepared to accept this view of Dr Brogger's and to consider the Prospect Mountain limestone as representing the Middle Cambrian or Paradoxides zone of the Atlantic Coast Province. A list of species published in 1886 is as follows: 5

1 Second contribution to the studios of the Cambrian faunas of North America. TJ. S. Geol. Survey, 

Bull. No. 30, 1886, pp. 30, 32.

2 Hague, Arnold. Abstract of Report on Geology of the Eureka District, Nevada. TJ. S. Geol. 

Surv., 3d annual report, 1881-'82, 1883, p. 255.

3 Second Contribution to the studies of the Cambrian faunas of North America. TJ. S. Geol. Survey, 

Bull. No. 30,1886, p. 32.

4 0m alderon af Olesellus zonen i Nordamerica. (On the age of the Olenellus zone in North 

America.) Aftryk ur Geol. Poren. i Stockh. FiJrhan, No. 101, Ed. 8, 1886, pp. 182-213.

8 TJ. S. GeoL Surv., Bull. No. 30, p. 32.
WAT.COTT.] SUMMARY UTAH AND NEVADA. 315

Obololla (like O. pretiosa). Protypus sonectus.

Lingula maiiticula. expansus.

Kntorgina whitfioldi. Dicellocephalus I nasntna.

Orthis enrekeusis. Ptycboparia oweni.

Stenothoca elongata. hagnei.

Agnostns communis. occidentalis.

bideus. dissimilis.

neon. Olenoldes spinosns.

ricliinondensis.

Of the succeeding formation, or the Secret Cauon shale, Mr. Hague 

says :

The Prospect Mountain limestone passes, by gradual transition, from shaly limestone into brown and yellow argillaceous shales. * * * In their broadest development they measure 1,600 feet, although in places where they are encroached 

upon by the Hamburg limestone they occur considerably thinner. 1

Only a few scattering fossils are found in the lower portion of the 

Secret Canon shale, but near the summit of the fauna is large and characteristic. It includes, according to Mr. C. D. Walcott, the following: 2

Protospongia fenestrata. Dicollocephalus richrnondeusia.

Lingtilepis maera. Ptycboparia peruasuta.

minuta. laticeps.

Lingula? manticula. bella.

Iphidea depressa. linnarssoni.

Acrotreta gemma. t oweni.

Kutorgina minutissima. hagnei.

Hyolithes primordialis. siiuilis.

Agnostus communis. nnisulcata.

bidens. Iteviceps.

neon. Chariocephalns tnraifrons.

seclusus. Ogygia? problematica. 

Dicellocephalus ? nasutus.

Of the species in this list DihelocepJialus "? nasutus, and D. riclimondensis do not belong to the genus Dikelocephalus and the form referred 

to Ogygia"}problematica, represents an undefined genus. As a whole, as 

suggested by Dr. Brb'gger, this horizon may possibly be referred to the 

Paradoxides zone.

Number 4 of the section, or the Hamburg limestone, is a dark gray 

and granular limestone; surface, weathering rough and ragged; only 

slight traces of bedding. Very few traces of fossils were found in the 

entire 1,200 feet of rocks referred to this formation.

No. 5, or the Hamburg shale, resembles the Secret Cafion shale except 

that it is by no means as uniform in composition, showing very rapid 

changes in conditions of deposition and becoming more or less arenaceous and calcareous throughout its development as well as in its lateral 

extension. Throughout its entire thickness of 350 feet fossils are more

 Abstract of Report on Geology of the Eureka District, Nevada. U. S. Qeol. Surv., 3d Annua1 

Report, 1881-1882,1883, p. 255. 

"Ibid., p. 32.
316 THE CAMBRIAN. tnm,i,«l.

or less abundant, but especially so near the summit where there were 

obtained the following:

Lingnlepis mtera.

minuta.

Lingula ? manticula. 

Obolella discoidea. 

Acrotreta gemma. 

Kutorgina minutissima. 

Agnostus communis.

bidens.

neon.

prolongus.

tumidosus.

tamifrons. 

Dicelloceplialus ? nasutns.

Dicellocephalus angnstifrous.

marica.

bilobus.

osceola. 

Ptycboparia affinis.

oweni.

haguei.

granulosa.

simulator.

nnisulcata.

breviceps.

Arethnsina americana. 

Ptychaspis minuta.

"Three of these species, Hyolithes primordialis, Dikelocephalus osceola 

and Ptychaspis minuta, are identical with forms from the Potsdam sandstone of Wisconsin." l As a whole the fauna is of the general facies of 

that of the Potsdam zone of New York and the Mississippi Valley. 

This is found in the Hamburg shale, but in the overlying Pogonip limestone there is an assemblage of species that combine both Cambrian 

and Lower Silurian (Ordovician) types. A short distance above, the 

fauna is comparable to that of the Calciferous and Chazy groups of the 

New York section.

Tbe transition from the Cambrian to the Silurian [Ordovician] fauna is very gradual, and such as would occur where there was no marked physical disturbance to influence the fannal change resulting from the natural dying out and development of 

species or the influx of new species from other areas.

Of the species occurring below the passage beds three are identical with species occurring in the Potsdam sandstone of Wisconsin, viz: Hyolithes primordialis, Dicellocephalus osceola, and Ptychaspis minuta; one, with Acrotreta gemma of the Calciferous 

formation of Newfoundland; and Ptychoparia oweni is a common species of the Potsdam horizon in Montana and Dakota. These specific identifications and the great 

development of species of the genera Agnostus, Dicellocephalus, and Ptychoparia in 

the middle and upper portion of the Cambrian section, furnish abundant evidence 

upon which to correlate the fauna and the geologic horizon at which it occurs with 

the Potsdam fauna and formation, as was done by Messrs. Hall and Whitiield (Geol. 

Expl. Fortieth Par., vol. 4, 1877, p. 199). Of the Potsdam fauna eleven genera and 

fifteen species continue on into the passage fauna, viz : (species of the Potsdam fauna 

are printed in italics); Lingulepis mcera, L. minuta, Lingula ? manticula, Discina (sp. 

undt.), Acrolreta gemma, Schizambon typicalis, Obolella ambigua, 0. discoidea, Leptaina mclita, Orthis hamburgensis, O. tostudiuaria, Triplesia calcifera, Tellinomya? 

hamburgeusis, Agnostus communis, A. lidens, A. neon, Dicelloceplialus finalis, 3J. iuexpectans, Ptychoparia? annectans, Ptychoparia affinis, P. granulosns, P. haguei, P. 

oweni, P. unisulcatus, Arethusina americana, Amphion (sp. undt.) Barrandia maccoyi, 

Illaiuurns eurekensis, Asaphus caribouensis.

In the next superior grouping, about midway of the Pogonip group, all the middle 

Cambrian genera, with the exception of Orthis and Illamurus, have disappeared, and 

higher up the genera Receptaculites, Chsctetcs, Pleurotomaria, Maclurea, Cypbasis, 

Bathyurus, and Asaphus carry the fauna up to the summit of the formation where the 

genera Receptaculites, Ptilodictya, Chsetetes, Strophomena, Orthis, Telliuomya,

1 Op. cit., p. 33.
SUMMARY UTAH AND NEVADA. 317

Modiolopsis, Macluroa, Crytolites, Ortlioceras, Endocoras, Coleoprion, Leperditia, 

Beyrichia, Ampliion, Coraurus, and Asaphus give it a facies approaching that of the 

Lower Trenton and indicating a horizon that is considered to be in a measure tlio 

equivalent of tbat of tbe Chazy formation of New York and Canada. Tbe fauna of 

tbe lower portion of the Pogonip group corresponds in tlie same manner to tbat of 

tbe Calciferous sand-rock of tbe same region. The large number of individuals of 

tbe species of Keceptacul ites, R. mammillaris especially, gives tbe fauna of the upper 

beds a character that this horizon has not hitherto had. This, united with several of 

the Trenton species, viz, Orthis tesliulinaria, 0. tricenaria, 0. perveta, Tcllinomya con- 

. tracta, two species of Modiolopsis allied to Trenton forms, and liaplmloma nasoni, 

strongly foreshadows the opening of tbe Trenton period. 1

The section of tbe Highland Range, 125 miles south of the Eureka 

section, gives a greater variation of sedimentation in the lower portion 

and less in the upper as compared with the Eureka section. The Highland Eange has a more abundant and more varied fauna in the lower 

1,500 feet above the quartzite, while in the Eureka section the upper 

or Potsdam fauna is much larger than in the Highland section. In each 

instance a massive limestone has replaced a succession of limestones 

and shales. The Highland Eange section measuring from the base is as 

follows: 2

Foot.

(1) Dark reddish brown quartzite, evenly bedded, and ripple-marked in some

places .......................................................... 350

(2) Bluish gray limestone .................................................. 35

Fossils: Olenellus yilberli.

(3) Buff argillaceous and arenaceous shales, more or less solid near the base

and laminated in the upper portions............................. fcO

Fossils: Annelid trails and fragments of Olenellus in the lower part. 

Higher up tbe beads of Oleiiellns yilbvrti and 0. iddinyni occur hi 

abundance.

(4) Light-colored gray limestone and bluish black limestone............ .... 16

(5) Sandy, buff-colored shale ............................................... 40

Fossils: Annelid trails, Cruzianasp. ?

(6) Dark bluish black limestone............................................ 46

(7) Finely laminated bull" argillaceous shale................................. 80

Fossils: Ifyolithcd Inttinysi and Ptyc'hoparia ptovhcnsis.

(8) Gray to bluish black compact limestone ................................ 18

(9) Buff arenaceous shales.................................................. (>4

(10) Compact cherty limestone.................. ............................ 50

(11) Compact shaly sandstone in massive layers.............................. 40

(12) Hard siliceous gray limestone, almost quartz at base.... ................. 12

(13) Yellow to buff, sandy shale............................................. 70

(14) Bluish black limestone ................................................. H;

(15) Yellow to buff sandy shales............................................. 40

(16) Bluish black, bard, compact limestone .................................. 12

Fragments of fossils.

(17) Shaly sandstone in massive layers...... .....*................ ........... 52

(18) Gray arenaceous limestone ............................................. 2

1 AYalcott, C. D.: Paleontology of tho Eureka Distiict. U. S. Gool.Surv., Monograph, vol. 8, 188^ 

pp. 3,4.

2 Walcotfc, C. D.: Second contribution to the studies of tljo Cambrian faunas of North America. TJ 

S. Qeol. Surv., Bull. No. 30, 1880, pp. 33, 34.
318 THE CAMBRIAN. IBULL.SI.

Feet.

(19) (a) Buff, Bandy shale......__..................................... 40

(6) Gray arenaceous limestone ..................................... 30

(c) Sandy, calcareous shale......................................... 3

 73

(20) (a) Massive-bedded, bluish gray limestone.......................... 200

Fragments of fossils.

(6) Compact gray siliceous limestone, almost quartzite in some places 400 

(c) Bluish black, evenly bedded limestone.......................... 6

 606 

Strike N. 30° W., dip. 10° E.

(21) Buff to pinkish argillaceous shale, with fossils, aud a few interbedded layers of limestone from 3 to 15 inches thick......................... 125

Fossils: Eocystites ?l lonyidactylus, Lingulella ella, Kntorgina pannula, 

Hyolithes tilling si, Ply'choparia piochensis, Olenoides typicalis 

Bathyuriscus howelli, and B, producta,

(22) Massive-bedded, siliceous limestone; weathering rough and broken into 

great belts, 200 to 300 feet thick, by bands of color in light-gray, 

dark-lead to bluish black; on some of the cliff faces the weathered 

surface is reddish ............................................... 1,570

(23) Bluish black limestone in massive strata, that break up into shaly layers 

on exposure to the weather. The latter feature is less distinct 850 

feet up, and the limestone becomes more siliceous, with occasional 

shaly beds...................................................... 1,430

Fossils; near the summit specimens were found that are referred to

Ptychoparia minor.

Quite a fauna occurs in 23, as found one mile farther south an the line of the section.

Summary of section.

Feet.

1. Qnartzite ................................................ 350

2. Limestone and shales (argillaceous and arenaceous) ....... 1,450

3. Massive limestones ....................................... 3,000

Total.................................................. 4,800

As in the Eureka section, the species of Olenellus have a very narrow range near the base of the limestone series above the quartzite.

The fauna found in No. 21 of the section materially strengthens the 

correlation of the fauna of the Prospect Mountain limestone and the 

Secret Canon shale with that of the Paradoxides zone of the Atlantic 

Basin.

The fauna of the great limestone belt above 23 of the section is represented by only a few specimens on the line of the section. A mile 

south, however, on the strike of the strata a strongly marked Upper 

Cambrian (Potsdam) fauna occurs. The species identified are as follows:

Bellerophon antiquatus. Dicellocephalus sp.?

Fleurotouiaria, 3 imdt. sp. Ptychoparia (Euloma?) dissimilis

Hyolithes, 3 n. sp. P. sp.?

Dicellocephalus pepineusis. Arethusina americana.

D. (type of D. minuesotensis). Illcenurus sp.?

Of this fauna two species are identical with those from the higher Potsdam fauna 

at Eureka, viz: Ptyclioparia (7?.?) dissimilis and Arethusina americana ; and Bellerophon 

antiquatus, and Dicellocephalus pepinensis occur ill the upper Potsdam of Wisconsin,
WALCOTT.] SUMMAEY UTAH AND NEVADA. 319

The presence of the Pleurotornaria-like shells and the species just mentioned, correlates the fauna with that of the upper horizon, of the Potsdam faunas of Wisconsin 

and Nevada. 1

We have no details of the section of Silver Peak, Nevada, to which 

attention was called by Prof. J. D. Whitney. The fossils are from a 

limestone and silico-argillaceous shale and identical with species found 

elsewhere. The most noteworthy occurrence is that of Arcliceocyathus = 

Spirovyathus atlanticus and a large brachiopod like Kutorgina cingulata, 

both of which occur on the Labrador coast over 3,000 miles to the northeast on the opposite side of the continent. The abundant and peculiar type of sponge Archccocyathus profundus of the L'Anse au Loup 

locality is represented by the nearly identical species Etlimoplvyllum 

whitneyi of Silver Peak, and the tribolite Olenellus gilberti is scarcely 

distinguishable from 0. thompsoni, as it occurs in L'Anse au Loup. 

The species now known from Silver Peak are: 2

Spirocyathua atlanticus. .Kutorgina (like K. cingulata). 

Arclueocyathus undt. sp. Hyolithes princeps. 

Ethmophyllum whitneyi. Oleuellus gilberti. 

Strephochetus ? sp. ?

The Cambrian rocks of Utah, as determined by the presence of the 

Cambriau fauna, form a narrow horizon in the vast series of sediments of which they are a conformable portion. Messrs. Eminons and 

King refer the 12,000 feet of siliceous slates and quartzites of the Big 

Cottonwood section to the Cambrian. If we provisionally drew the 

basal line of the Cambrian at the base of the strata known to contain 

the Olenellus fauna, all but 250 feet of this section would be referred to 

the Algonkian, but from the known range of Olenellus in the stratigraphically equivalent series to the north in British Columbia, the view 

is no longer tenable. The upper portion of the section consists of 250 

feet of hard silico-argillaceous shale, a little sandy in places. At the 

base a species of Crnziana was found, associated with Olenellus gilberti, 

and 100 feet higher in the section a band of shale afforded lAngulella ella, 

Kutorgina pannula, Hyolithcs billingsi, Leperditia argenta, Ptychoparia 

quadrans, and Bathyuriscus producta. This list was published in 18SG, 

along with Cruziana and Olenellus gilberti, as characterizing the shales 

at the summit of the great series of quartzites and slates. As in the 

Eureka and Highland Range sections, the Olenellus zone is confined to 

a very narrow belt just above the quartzite. The silico-argillaceous 

shales above occupy the position of the 4,650 feet of Prospect Mountain 

limestone and Secret Cafion shale of the Eureka section. The Hamburg limestone and Hamburg shale of the latter are absent in the 

Big Cottonwood section, causing an unconformity by uondepositiou.3 

The section in the Oquirrh liauge above Ophir City has a quartzite at 

the base with shales above it carrying Lingnlella ella, Olenellus gilberti, 

and Batliyurisciis producta, as determined by the collections brought in

1 Op. cit., pp. 35, 38. 2 0p. cit., p. 38. "Op. cit., p. 39.
320 THE CAMBRIAN. [BULL. 81.

by the Wheeler survey. It is probable, however, that as in the case of 

the Big Cottonwood section, Olenellus gilberti occurs at the base of the 

shale, aud the other two species at a higher horizon. At Antelope 

Spring, in western Utah, there is a considerable development of the 

Middle Cambrian zone corresponding to No. 21 of the Highland Eange 

section and a portion of the Prospect Mountain limestone of the Eureka 

section. The section at this locality as measured by Mr. G. K. Gilbert 

is as follows : l

Feet.

1. Gray, massive limestoue......... ...................... 200

2. Blue gray, calcareous slialo; fossils (as corrected by C. D. 

W.); Aorotliele tmlsidiia, Aynostus intcrstrictits, Olenoidcs 

nevadensis, PlycUoparia kingi, P. housensis, and Asaphiscus 

wheeleri. ................................................ 200

3. Gray liuiestoue, liglit and dark, cbielly massive............ 1)00

4. Vitreous saudstone, umber-brown on weathered face; base

not seen ................................................ 1,000

Total............................. .................... 2,300

No. 4 of this section corresponds to the basal quartzite of tlie Eureka 

and Highland Eange section, aud No. 3 with the Prospect Mountain 

limestone. 13o. 2 may correspond to the upper portion of the latter 

limestone or to the lower portion of the Secret Canon shale of the 

Eureka district. There is not enough known of the Antelope Spring 

section to enable us to make any closer correlation.

A comparison of the sections of Utah with those of Nevada shows 

that in the former the earlier conditions of sedimentation were apparently the same from the base of the Wasatch Mountains westward 

into central Nevada. But during the deposition of the Middle and 

Upper Cambrian rocks the immediate vicinity of the Wasatch was an 

area of minimum deposition, while that of central Nevada was one of 

maximum deposition of sediments. What the conditions were during 

the deposition of late Middle and Upper Cambrian time in the Wasatch 

area are unknown. The appearance of the rocks indicate a shallow 

sea with very little deposition of sediment.

IDAHO.

What is known of the Cambrian rocks of Idaho is obtained from the 

writings of Messrs. Bradley and Peale. The report of the former is 

more that of an explorer who, passing over the ground, made such geologic notes as time permitted. In the vicinity of Malade City, in southeastern Idaho, he discovered in a limestone resting on a quartzite, 

fifteen species of trilobites of the genera Conocoryphe, Bathyurus, Dikelocephalus, Agnostus, etc., five brachiopods, two gasteropods, aud 

one pteropod. He referred this fauna to the Quebec group, and the

1 Report on the geology of portions of Nevada, TJtali, California, and Arizona examined in the years 

1871 and 1872. Keport on Geog. and Geol. Expl. and Survey weat of the lOOtli world., in charge of 

Lieut. Geo, M, Wheeler, vol. 3, Geology, 1875, p. 107.
WALCorr.] SUMMARY IDAHO. 321

quartzitic sandstone beneath is spoken of as occupying the relative 

position of the Potsdam, although he subsequently refers to it as a 

part of the true Quebec.1 Mr. F. B. Meek agreed with Prof. Bradley 

that the launa belonged to the Quebec horizon; and he 2 described 

Bathyurellus (Asaphiscus) bradleyi and Asaplius (Megalaspis ?) goniocercus. The latter species probably comes from the upper portion of the 

limestone referred to the Quebec group by Prof. Bradley.

From the data obtained by Dr. A. C. Peale of the Gallatin Eiver Cambrian, and our more accurate knowledge of the fauna of tbe Quebec 

group, the faunas occurring in the lower portion of the limestone at 

Malade City are referred to the Upper Cambrian, and those from the 

upper portion of the limestone to a portion of the Lower Silurian (Ordovician). In this connection reference should be made by the reader 

to Prof. Orestes St. John's work upon the same beds in Wyoming.

Near the south end of Portneuf Range, north of Malade City, Dr. A. 

C. Peale measured the following section :3

Top.

Feet.

1. Blue limestone .................................................. 130

2. Laminated blue limestones, with Conocoryphe, Dikellocephalus, )

Obolella, and two species of Bathyurns ....................... > 315

3. Bluish gray limestones.........................................)

4. Laminated limestones, with bands of greenish shales in the upper 1 

portion. The limestones are separated by shaly layers. The 

limestones are fossiliferous at the base, containing quantities 

of a trilobite like Conocoryphe. The limestone resembles an 

oolite, but the structure is probably due to the presence of 

some peculiar organic remains. Fragments of Discina were 

seen........................................................

5. Rather massive limestones .....................................

6. Laminated blue limestones, in bands of from 1 to 2 inches thickness, the surfaces of which are yellow-stained. j

7. Rather massive limestones...................................... J

8. Green shales or slates, 15 feet.................................. > 118

9. Bluish gray limestone......................................... )

10. Bluish limestones, with bauds of shales.......................... 155

11. Massive blue limestones. The dip here appears to be about 40°... 100

12. Laminated limestones with interlaminated green shales .......... 70

13. Greenish sandstones and shales, passing below into silvery gray

slates......................................................... 210

14. Slates and shales with a band of limestone about the middle...... 185

15. Blue limestones with irregular structure. The strike is about 

south 5° east, and beyond the station it appears to curve to the 

south; dip is 60°.............................................. 70

16. Rusty yellow quartzite ........................................... 150

17. Gray and yellowish quartzites................................... 450

18. Greenish gray slates ............................................ 180

19. Rusty yellow quartzite, somewhat couglomoritic and containing a

considerable percentage of iron.......................... ...... 130

20. Rusty quartzites, about......................................... 600

21. White quartzites...... ........................................ ? fnn , ,.nn

22. Pink and white quartzites.................................... ' ouu to ouu

23. Red slates, thickness not taken ..............................,

*nn

Total....................................................... 3,483to3,583

1 Report of Frank H. Bradley, geologist of the Snake River division. TJ. S. Geol. Surv. of the Terr., 

6th Ann. Rep., 1873, p. 201.

2 Preliminary paleontological report; with remarks on the ages of the rocks, etc. U. S. Geol. Surv. 

of tbo Terr., embracing portions of Montana, Idaho, Wyoming, and Utah, 6th Ann. Eep., Ibid. 1873, pp. 

480-^85.

3 Report on the geology of the Green River District. U. S. Geol. Surv. of the Terr., llth Ann. Rep., 

1879, p. 508.

Bull. 81 21
322 THE CAMBRIAN.

Below this last layer there are probably the limestones of the Red 

Eock Pass.

This section is one of considerable interest, from the fact of its having the Upper Cambrian fauna in the upper portion and an alternating 

series of limestones, shales, and quartzites below, which, from a comparison with the sections of western Utah and central Nevada, occupy 

the stratigraphic position of the Middle Cambrian. In their downward 

continuation, they may also include the Lower Cambrian zone. This 

is a question which is to be settled by future investigation.

In the adjoining Bannock range to the west, Dr. Peale studied a section 

of the series of quartzites and slates that apparently correspond to those 

of Nevada and Utah, occurring beneath the Lower Cambrian (Olenellus) 

zone. The section figured by Dr. Peale includes 5,710 feet of quartzites 

and slates, with a little interbedded limestone. He compares it with 

the section on the western side of the Wasatch range, referred to the 

Cambrian by Messrs. Eminons and Hague.1 In his r6sum6 of the formations, the Cambrian or Primordial is made to include the quartzites 

and slates that may be tentatively assigned to the Algonkiau, or to the 

Cambrian, but preferably to the latter. To the Canadian Period there 

are referred 1,300 feet of interlaminated limestones and quartzites that 

occur above the quartzite and slate series now referred to the Cambrian. 

Dr. Peale states that west *f Malade City the section gives 2,000 feet 

of strata placed in the Quebec series by Prof. Bradley.2

The northern end of the Port Neuf range was studied by Prof. Orestes 

St. John, in the vicinity of Mount Putiiam. He there found the section 

to be formed of quartzites, chloritic schists, slates, and micaceous shales 

at the base, above which comes the dark red, finely laminated sandstone in thick beds. These he referred to the Potsdam with a query. 

In speaking of this section, Dr. Peale says he thinks Prof. St. John is 

inclined to refer the base of the section to the Huronian.3

With the information afforded by his own survey and that'of Prof. 

St. John, Dr. Peale constructed the following table as embodying their 

knowledge of the Lower Paleozoic section of Idaho : 4

1 Op. cit., p. 570. * Op. cit., p. 614. 8 Op. cit., p. 615. « Op. cit., p. 615.
WALCOTT.] SUMMAKY MONTANA. 

Silurian section.

323

Canadian. '

Primordial. II Cambrian or

V

<o 10"

Calcifer- ous?

Potsdam.

?Acadian 

Possibly ?Huronian 

Cambrian quartzites.

Cambrian slates.

Blue and gray limestones, with characteristic 

Quebec fossils.

Blue limestones, generally laminated, with alternations of greenish sandstones and shales 

and siliceous slates.

Pink and white quartzites, conglomeritic at 

top, with thin layer of limestone at the base.

Olive-green and gray chloritic slates and indurated clay slates.

Silvery and steel-gray micaceous slates.

Dark quartzites with interlaminated slates.

Red quartzites and quartzitic sandstones, with conglomeritic and ehaly layers.

Limestones.

Very dark green chloritic schists, containing quartz 

and serpentine seams and interlaiuiuated bands of 

metamorphosed argillaceous slates, and a band of 

pink quartzite 200 feet thick.

1,000 ft. +

«8

0

o \a

2,000 ft. +

d

o

COm

r-T

<s

o 

o

°i i-T

*

o 

o

to

1 1

«

.0iO

n

«B

o 

o 

os

d 

+

o

o in_

r-T

« 

+

sOt>~

«

o

Br-T

rt 8 

55 co

O^H

fc a

(3.2 _0-W '-3

0

<a

CO

i> i^.

a ' s o

 s

(jf c*

6

fc

a 

o '-S 

o

O) O2

Section 32, station 132. No 

In copying the table it has been reversed, so as to follow the natural order. As interpreted in the light of our present knowledge of 

the Cambrian rocks in the Kocky Mountains, the Quebec and Oalciferous of this section are referred to the Upper Cambrian. Whether the 

rocks referred to the Potsdam and Acadian are of Cambrian age or not 

will remain undetermined until some paleontologic proof is obtained.

MONTANA,

As far as known, the Cambrian rocks of Montana are restricted to the 

southern portion of the State. Two areas are well defined, one about 

the northern end of the Big Horn range and the other within the area 

drained by the Gallatin and the Yellowstone Eivers.
324 THE CAMBRIAN. [Buu,.8L

The character of the Strata forming the Cambrian about the Big Horn 

Mountains will be spoken of in connection with the extension of that 

range in Wyoming. The Grallatin section of the Cambrian includes 

1,250 feet of strata, of which 835 feet are limestone, restiug upon 415 

feet of sandstone. Conformably subjacent to the latter, there are 5,000 

feet of alternations of conglomeritic, micaceous sandstones, with bands 

of siliceous limestones and indurated clay shales, referred to the Algonkian by Dr. A. C. Peale. l

A more detailed manuscript section, that Dr. Peale kindly prepared 

at my request, is as follows:

f Pebbly limestonts 145 feet.

(fossils, Leptcena melita, Ophileta sp. ?

Triplesia calcifera, Ptychoparia sp. ? 

Ptychoparia (E.) affinis'). 

Dry Creek shales 30 feet. 

Mottled limestones 160 feet.

(fossils, Ptychoparia sp. ? Hyolifhes sp. ?)

Gallatin limestones 835 feet.. Obolella shales 280 feet.

(fossils, Obolella sp. ?) 

Trilobite limestones 120 feet.

(fossils, Lingulella sp., Acrotreta gemma.

Kutorgina sculptilis, Agnostus lidens. 

. Hyolithes gregaria, Olenoides serratus. 

Ptychoparia gallatinenses. 

Bathyuriscus f haydeni). 

( Gallatin shales 290 feet.

Gallatin sandstones 415 feet. .. J (fossil8> Hyolithes sp. ?

Gallatin quartzite 125 feet.

It is probable that the 5,000 feet of strata referred to the Algonkian 

in the published section will ultimately be referred to the Lower Cambrian as they occupy the stratigraphic position of the Bow River series 

to the north in British Columbia through the upper 3,000 feet of which 

the Olenellus fauna has been found to range.

The section near the mouth of the East Gallatin River was studied 

in detail by Dr. Peale in 1884, and two lithologically well defined groups 

determined and characterized as follows :

To the lower one, which was carefully searched, without success, for organic remains, the name of East Gallatin group has been provisionally applied. It is composed of a series of alternations of green and greenish gray micaceous sandstones and 

clay slates (almost argillites), with thin bands of laminated limestones ; 2,300 feet of 

these beds were sectionalized in detail without any traces of fossils being found,

The sandstones are in heavy beds and present a somber appearance, weathering on 

exposed surfaces to steel-gray and almost black colors and frequently breaking into 

cubical blocks. The slates are blue, yellowish, olive-green, and at some places red. 

In the limestone a concretionary structure* is frequently noticed. For the upper 

group, lying above a well defined pink quartzitic sandstone, we have retained the 

name Potsdam. Green and dark purplish red micaceous shales, mostly arenaceous, 

with occasional thin bands of limestone, make up this group, and many of the beds 

are highly fossiliferous. The collections have not been carefully studied yet, and we 

therefore simply refer to them in this general way at this time. 2

1 Report of Dr. A. C. Peale (on the Montana division of geology). TJ. S. Geol. Surv., 10th Ann. Hep., 

1890, p. 131. 

*Hayden, F. V.: Keport Montana Division. IT. S. Geol. Surv,, 6th Ann. Kep., 1884-'85, 1885, p. 50.
WALCOTT.J SUMMARY MONTANA. 325

The fauna collected in the Gallatin Eiver section by Dr. Hayden in 

1872 was studied by Mr. Meek, who recognized eighteen species. From 

the lowest division he identified the genera Cruziana, Lingulepis, or 

Lingula, Conocoryphe, Bathyurus, or Asaphus. From the third division he described Bathyurus serratus, B. ? liaydeni, Conocoryphe (Conocephalites) gallatinensis, IpMdea subtilis, an&Agnostus Mdens ; and identified a species of Conocoryphe, Hyolithes gregaria, and Acrotreta subconica. From the second division the genera Acrotreta and Lingula 

are identified, and from the upper or first division Asaphus ?, Bathyurus? Conocoryphe, and Lingulepis.1 This fauna has the facies of 

the Upper Cambrian zone, although that of the fourth or lowest division may prove to belong to the Middle Cambrian. As a whole the 

Cambrian of the Gallatin region is formed of a sandstone at the base, 

above which occur limestones carrying a fauna characteristic of the 

upper portion of the group.

The presence of the Upper Cambrian on the southwestern side of the 

Little Belt Mountains and on the southern side of the Elk Eange was 

proved by Messrs. Dana and Qrinnell when they discovered fossils of 

this age. The section near Camp Baker, southwest of the Little Belt 

Mountains, is estimated as follows :2

Quartzite, 20 feet; variegated shales, mostly bright red, also green and blue, 150 

feet; limestone iu a double series of ledges, 80 feet; quartzite, reddish, slightly micaceous, then a series of colored slates, mostly green, followed by shales and thin beds 

of sandstones and limestones, in all probability 1,500 feet; still further conformable 

shales, 1,000 feet. These extend toward the north farther than we could follow 

them. It is enough to say that the total thickness of the conformable strata underlying the fossil-bearing limestone can not be less than 3,000 feet, and is probably 

much more.

The same authors state that they identified similar rocks at Moss 

Agate Springs, at the south extremity of the Elk Range of mountains. 

The strata there are red shales, quartzites, and limestones like those at 

Camp Baker, the limestones containing many fragments of trilobites. 

The fossils collected were studied by Prof. E. P. Whitfield, who described Crepicephalus (Loganelhts) montanensis and Arionellus tripunctatus,3 species that occur in the Upper Cambrian horizon, the former in 

the Black Hills and Big Horn Eange, and the latter in central Texas.

From his observations at numerous points Dr. F. V. Hayden coneluded that the outcrop of the sandstone referred by him to the Potsdam extended entirely around the Big Horn Mountain Eange. Near 

the sources of Powder Eiver he found a series of sandstones underlying 

the Carboniferous limestone, resting unconformably upon the schistose 

and clay slates of the Azoic series in very nearly the same manner as

1 Preliminary paleontological report . . . with remarks on the ages of the rocks, etc. U. 3. 

Geol. Surv. of the Terr., 6th Ann. Rep., 1873, pp. 403, 464.

2 Geological report. Eeporb of a geological reconnoissance from Carroll, Montana Terr., on tho 

Upper Missouri to the Yellowstone Park and return, made in the summer of 1875, by Wm. Ludlow, 

1870, p. 133.

3 Descriptions of new species of fossils. Ibid. p. 141.
326 THE CAMBRIAN. IBULL.SI.

in the Black Hills. The Potsdam sandstone in this region is quite well 

developed, attaining a thickness of 200 feet, and exhibiting, as usual, 

various lithologic characters. Near the base, the rock is of a reddish 

flesh color, very compact, composed of an aggregation of quartz pebbles, varying in size from a minute grain of quartz to masses half an 

inch in diameter, cemented by siliceous matter. Above, the rock is in 

thin ferruginous layers, slightly calcareous but mostly siliceous, and 

with many small particles of mica. These thin layers are also charged 

with fossils, such as Lingula antiqua, Obolella nana, Theca gregaria, and 

Arionellus ? oweni. Many of the slabs are covered with fucoidal markings and what appear to be tracks and trails of worms.1

CANADIAN EXTENSION.

Our knowledge of the Cambrian rocks of this region is mainly limited 

to the vicinity of the line of exploration across the Rocky Mountains in 

the vicinity of the Canadian Pacific Railway. They occur in western 

Alberta and eastern British Columbia, as is shown in the plates and 

sections accompanying Mr. R. G. McConuell's paper.2 The geographic 

distribution and the localities mentioned by Mr. McConnell are represented on the map accompanying the report of the Geological Survey 

of Canada for 1882.

The Cambrian section, identified by fossils, includes the upper portion of the Bow River group and the lower part of the Castle Mountain 

group. The Bow River group forms the basal member of the section in 

the Bow River Valley and Cathedral Mountains. It consists mainly of 

a series of dark colored argillites, associated with some sandstones, 

quartzites, and conglomerates. The argillites are usually dark grayish 

in color, but become greenish and purplish in places 5 are very impure, 

and frequently grade into flaggy sandstones that are often slightly calcareous. The conglomerates of this series are characterized by pebbles 

of milky or semitransparent quartz, and by pieces, similar in size and 

fresh looking, of whitish feldspar, and the matrix contains an abundance 

of pale mica. These constituents have evidently been derived from 

some not far distant exposures of coarse granite or gneissic rock. The 

conglomerates characterize more especially the top of the formation, 

and occur in thick, massive looking bands, alternating with quartzites 

and shales. The quartzites, like the conglomerates, are mostly found 

in the upper part of the formation, and sometimes, as in Cathedral 

Mountains, replace the latter altogether. The only fossils detected in 

the Bow River series are specimens of Olenellus gilberti, found about 

2,000 feet below the top of the formation and at the summit of Vermilion 

Pass.

4 The Primordial Sandstone of the Kocky Mountains in the North Western Territories O/ tie 

States. Ani. Jour. Sci., 2d ser., vol. 33, 1862, pp. 71, 72.

6 Report on the Geological Structure of a portion of the Rocky Mountains, with a iection. Geol. 

Surv. Canada, new ser., vol. 2, 1886-'87, pp. 24D-30D.
WALCOTT.] SUMMARY CANADIAN EXTENSION. 327

Attention was called to the resemblance of the strata of the Bow 

River series to those of the Big Cottonwood Canon section of the 

Wasatch Mountains of Utah, by Dr. GT. M. Dawson, in 1885. A comparison of the two leads to their correlation as equivalent formations, 

on the evidence of their lithologic characters and stratigraphic position 

and the fact that the Olenellus fauna occurs in the upper portion of 

each section. In his paper of 1889 Mr. E. G. McOonnell 1 states that 

specimens of Paradoxides and other fossils were found at the junction 

of the Bow River and the superjacent Castle Mountain group. A collection made at this horizon was sent to me for examination, and I 

identified Olenellus sp. undt., Protypus senectus, and a species of Ptychoparia undistinguishable from P. adamsi of the Olenellns zone of Vermont. 

The occurrence of the Olenellus fauna at this horizon and of Olenellus 

gilberti, 3,000 feet lower in the section, corresponds to the great range 

of the fauna in the New York and Vermont sections.

The Castle Mountain group, in the Castle Mountain section, commences with a thin band of shaly limestone, above which come 1,500 

feet of massive dolomites. These are subjacent to some yellowish, 

compact, impure dolomites, above which 300 feet of reddish shales occur subjacent to several hundred feet of shaly magnesian limestones. 

The Mount Stephen section shows about 5,000 feet of beds, consisting 

mainly of heavy dolomites, with shaly bauds at intervals. One of these, 

occurring at the base of the formation and another about 2,000 feet 

higher up, are rich in trilobites.2

Reference has already been made to the fauna occurring at the base 

of Castle Mountain. From the next fossiliferous zone, 2,000 feet up in 

the section, the following species have been obtained:

Lingulella macconnelli. Agnostua iiiteratrictna.

Crania? columbiana. Olenoidea nevadensis.

Kutorgiua prospectenaia. Zacanthoides apinoaua. 

Acrotreta gemma, var. depressa. Ptychoparia cordillerae.

Lmnarsounia aagittalia. Bathyuriacus hovvelli.

Ortkiaina alberta. (K.) dawaoni.

Platyceras roiningeri. Karlia atephenensia.

Hyolithellus micana. Ogygopaia klotzi.

Where the line between the Cambrian and the Lower Silurian (Ordovician) is to be drawn in the Castle Mountain group is still undetermined. The discovery of a specimen of Ptychoparia oweni in the 

debris washed down by the Cascade River from the Cascade Mountains 

indicates the presence of the Upper Cambrian fauna in this region, and 

it is not improbable that it will be found in the Castle Mountain or 

Mount Stephen section.

1 Notes on the geology of Mount Stephen, British Columbia. American Goologist, vol. 3, 188D, pp. 

22-25.

. 2 Report on the Geological Structure of a portion of the Kocky Mountains, with a section. GeoL 

Surv. Canada, new sor. 1886-87,1887, pp. 24-20B.
328 THE CAMBE1AN. [BULL. 81.

The sedimentation of the western area is much more varied and 

larger than that of the eastern side of the Rocky Mountains. The 

southern portion, represented by the Eureka District section, extending from the basal quartzite to the base of the Lower Silurian (Ordoviciau), is a continuous conformable succession of limestones and calcareous shales, with the exception of a narrow belt of arenaceous 

shales resting directly upon the lower quartzite. The calcareous sediments are 6,200 feet in thickness and include the faunas of the Middle 

and Upper Cambrian. The Lower Cambrian fauna is well developed 

in the shales between the limestone and the quartzite. The Highland 

Range section, 125 miles to the south, has a thickness of 4,800 feet of 

limestone, between the quartzite and the Lower Silurian (Ordoviciau). 

Proceeding eastward from central Nevada to northern central Utah, 

the Cambrian formations thin out, and on the flanks of the Wasatch 

Mountains are represented by 250 feet of argillaceous and siliceous 

shales above the basal quartzite. In this section only the Lower and 

Middle Cambrian faunas are found. The three thousand 'or more feet 

of limestone, with an abundant Upper Cambrian fauna, found in central 

Nevada, is unrepresented.

A comparison of the section in the Wasatch Mountains with that of 

Nevada shows that in both the earlier conditions of sedimentation 

were apparently the same. But during the deposition of the Upper 

and Middle Cambrian rocks, in the immediate vicinity of the Wasatch 

Range, it was an area of minimum deposition of argillaceous sediment, 

while that of Central Nevada was one of a great accumulation of calcareous sediment.

What the conditions were in the vicinity of the Wasatch Range 

during the deposition of the great calcareous deposits of central Nevada 

of Upper and Middle Cambrian times is largely conjectural. The 

physical appearance of the rocks indicates a shallow sea with very 

little deposition of sediment during the earlier portion of Cambrian 

time, and either a very shallow sea without deposition of sediment or 

a very deep sea without deposition of sediment, during the latter part 

of Cambrian time. It may be that some sediment was deposited and 

subsequently was removed by erosion, but this is exceedingly doubtful. 

The pure limestones of the Lower Silurian (Ordovician) rest directly 

upon the shales of the Cambrian, without any apparent unconformity.

To the north, near Malade City, Idaho, there are 1,200 to 1,400 feet 

of limestones that occur above the series of quartzites and slates. The 

sedimentation is essentially the same as that of central Nevada wi5h 

the exception of a less amount of calcareous sediment above the basal 

quartzite. The Upper Cambrian fauna has been found, but not the 

Middle or Lower fauna. Still farther to the north, in western Alberta, 

and eastern British Columbia, the same series is represented in the Bow
SUMMARY ROCKY MOUNTAIN PROVINCE. 329

Eiver quartzites and slates. The Cambrian section at this point also 

agrees closely with that of Nevada. The Olenellus fauna occurs at the 

base of a thick series of limestone, and in calcareous shales, 2,000 feet 

higher up, the Middle Cambrian fauna is well developed. Where the 

line between the Cambrian and Lower Silurian (Ordoviciau) is to be 

drawn in this great series of limestone and calcareous shales is still undetermined.

U.C.?

LC. MC.

L.C!>

14 13

FIG. 3. Sections of tbe Eocky Mountain province, vertical scale 6,400 feet to the inch. The number beneath each section corresponds to the locality number on Pis. i and 11.

The presence of Olenellus gilberti 3,000 feet down in the Bow Eiver 

quartzite and shales gives strong reason for referring the entire Bow 

River, Idaho, Wasatch, and Nevada quartzite and shales series to the 

Lower Cambrian. We know that the vertical range of the fauna is 

'great in the Appalachian sections and also in British Columbia.

As a whole the sedimentation in the vicinity of the shore line of 

Utah was limited in amount in later Cambrian time, and consisted 

mainly of siliceous and argillaceous rnuds. In the deeper sea to the 

westward a great accumulation of calcareous sediment rests upon the 

basal quartzite, and this continues to southern central Nevada. To 

the northward there is a decrease in thickness of the limestones across 

Idaho. In British Columbia the section i» more like that of central 

Nevada.
330 THE CAMBRIAN. [BULL. 81.

A comparison of the sections of the area on the eastern side of the 

Eocky Mountains with that of the western sustains the view that during late Algonkian ?, Lower Cambrian, and Middle Cambrian time the 

eastern Eocky Mountains and the plains to the eastward were above 

the sea level, whilst to the west the sediments of the later Algonkian ?, 

Lower Cambrian, and Middle Cambrian were accumulating west of the 

line of the Wasatch Mountains and the extension of this line nearly 

due north into British Columbia. Over all this region the coast line 

and sea bed appear to have undergone a gradual depression during 

early Cambrian time, and a relatively rapid depression at the beginning of Middle Cambrian time. (Fig. 3.)

THE INTERIOR CONTINENTAL PROVINCE.

This province includes the Upper Mississippi area; the eastern border or Adirondack sub-Province, the western border or Eocky Mountain sub-Province, and the Llano County area of central Texas and 

the Grand Canon of Arizona as a minor southwestern sub-Province.

The Lake Superior sandstones and. the controversy in relation to 

them will be noticed under a separate heading, after the description of 

the recognized Upper Cambrian rocks of Wisconsin, Iowa, and Minnesota and their Canadian extension.

UPPER MISSISSIPPI VALLEY.

In the historical review the literature pertaining to these rocks has 

been considered under the headings of "Wisconsin," "Minnesota," and 

" Iowa," but as the strata all belong to one geologic basin it is considered best to speak of them collectively.

The formations that have been correlated with the Potsdam sandstone of New York will be treated of under two headings: (1) The 

St. Croix or " Potsdam " sandstone proper, and (2) the sandstone of 

the south shore of Lake Superior.

The St. Croix ("Potsdam") sandstone. The greater portion of the exposures of the St. Croix or Lower sandstone occurs in Wisconsin, and it 

here also presents many variations in sedimentation and fauna. Its 

lower beds rest on the great pre-Cambrian nucleus of the center of the 

State, extending about it from the Michigan line on the northeast to 

where it passes into Minnesota on the northwest. Its line of contact 

with the superjacent Magnesian limestone is also very extended owing 

to the numerous streams that have cut through the limestone down into 

the sandstone throughout its line of outcrop. The epoch was one of 

accumulation of sand. The rocks are mainly light-colored sandstones 

in central and southern Wisconsin, but embrace some beds of limestone 

and shale. The maximum known thickness is about 1,000 feet. The 

fauna is large and varied, and contains trilobites, gasteropoda, ptero-
WALCOTT.] SUMMARY UPPER MISSISSIPPI VALLEY. 331

pods, and brachiopods. The succession of beds is, according to Prof. 

T. C. Oliamberlm, as follows r 1

On the southern side of the Archean Island the lower part of the formation usually 

consists of coarse quartzose sand, of an exceedingly open, porous nature, with but 

little aluminous or ferruginous and almost no calcareous matter. Higher in the 

series the sandstone becomes finer grained and the accessory substances named more 

abundant. Somewhat above the middle of the series a stratum of shale occurs, attaining a known thickness of 80 feet. This is not everywhere present and seems to 

be mainly developed at some distance from the ancient shore line. It appears to 

indicate that for a time there was a deepening of the waters, admitting of the accumulation of fine sediment, except near the shore, where the deposit of sand continued. 

Above the shale the sandstone, reaching a thickness of 150 feet, is again found. This 

is medium or coarse-grained and slightly calcareous. It, in turn, is overlain by a 

deposit of associated shale and limestone (the Mendota limestone), which attains a 

thickness of 35 feet in the vicinity of the lake from which it derives its name. These 

beds indicate a modification of the conditions of deposition, such as to permit not 

only the settling of fine sediment, but the accumulation of calcareous mud as well. 

The latter was doubtless derived from the calcareous remains of life, since the sea 

then swarmed with living organisms whose shells and skeletons are found entombed 

in the strata. The frequency of broken and worn fragments implies that the greater 

portion were ground to powder, forming the calcareous flour that subsequently hardened into limestone. These beds appear to point quite surely to a moderate deepening of the waters.

Overlying this impure limestone is a third and thinner bed of sandstone (the Madison) with which the Potsdam series closes. This, on the whole, is finer grained than 

that below, and is bound more firmly together by cementing material, which is 

mainly a calcareous and ferruginous infiltration. The thickness of this bed is about 

30 feet.

In eastern Wisconsin the formation is divided by Prof. Chamberlain 

into six parts, as follows,beginning at the top:

Feet. 

Sandstone (Madison) .......................................... 35

Limestone, shale, and sandstone (Mendota)...................... 60

Sandstone, calcareous......................................... 155

Bluish shale, calcareous ....................................... 80

Sandstone, slightly calcareous................................. 160

Very coarse sandstone, noncalcareous ......................... 280

The thicknesses given are subject to considerable variation. As a general rule 

they grow less toward the northeast. Where the total thickness of the formation is 

reduced by the inequalities of its Archean bottom it is by the loss of the lower 

members of the group and not by the thinning of all. 2

The Upper or Madison sandstone is described as a rather coarsegrained, thick-bedded, compact, but soft, slightly calcareous, light-colored sandstone. In its upper portion, immediately beneath the lower 

Maguesian limestone, it is at most localities coarse, and the topmost 

layer is often broken up and mixed with calcareous material, giving it 

acoarsely brecciated structure. The subjacent limestone (Mendota) consists of a group of alternating strata of arenaceous magnesian limestone, sandy calcareous shales, and shaly and calcareous sandstones. 1

1 General Geology. Historical Geology. Paleozoic Era. Geology of Wisconsin. Survey of 1873-'79, 

vol. 1, 1883, pp. 121,122.

[Geology of eastern Wisconsin.1 Chapters 7 and 8. Lower and Upper Silurian. Geology of Wisconsin, Survey of 1873-79, vol. 2,1877, pp. 269,260.

»0p.cit.,p.260.
332 THE CAMBRIAN. IBULL.S!

The upper and lower limits of the Mentiota group are scarcely definable. It graduates above into Madison sandstone, so as to make it 

difficult to draw a line between the two, and below the alteration of 

calcareous and arenaceous rock make it equally difficult to say where 

the series ends. The Mendota beds are regarded as the eastern equivalents of i)r. Owen's Fifth Trilobite .bed, the common horizon being 

characterized by the presence of Dilcelocephalus minnesotensis, D. pepinensis^Lingula aurora, L. mosia, and a few other species of limited horizontal distribution. The lower divisions constitute the main body of the 

Potsdam sandstone and present but very few exposures in this region. 

They are divided into four parts.1

The strata referred to the Potsdam sandstone by Prof. E. D. Irving 

in central Wisconsin have a surface distribution of over 6,000 square 

miles. 2 In the vicinity of Madison the following succession of layers 

between the Mendota base and the Archean occurs :3

Feet.

1. Greensand layer............................................ 1

2. Calcareous and dolomitic, friahle, fine-grained, greenish sandstone ......................................... .. 31

3. Not known......__.........._.......................... 31

4. Light colored sandstone, for the most part purely siliceous, 

being made of rolled quartz grains; but no specimens obtained from the uppermost layers....................... 704

5. Red shale.................................................. 10

Total................................................... 777

The generalized section given above for the Potsdam series, below the Mendota 

base, holds true for a large part of the central Wisconsin district, and would be satisfactory for all of it but for the facts next to be stated. *

Prof. Irving then proceeds to describe layers of sandstone and bowlder-conglomerate occurring near the pre-Cambrian quartzite, which 

apparently occupy a higher position and extend downward across the 

upper portion of the eastern Madison section. He explains this occurrence on the theory of the accumulation of these conglomerates and 

sandstones near the shore line at a higher level than the sandstones 

that accumulated offshore.

The beds of passage between the Potsdam and Lower Magnesian series include, as 

already said, two well marked beds, 60 to 90 feet in combined thickness the Mendota limestone and the Madison sandstone.6

Of the fauna in the rocks he says:

To the list of fossils of the lower sandstone series given by Prof. Hall but little has 

been added by the present survey, as far as central Wisconsin is concerned. * * * 

The general grouping of upper, middle, and lower species appears to hold true as 

regards the order, but his lower species must really be assigned to the middle of the 

series, since its thickness is about twice as great as Mr. Hall supposed.6

1 0p.cit.,pp.261,262.

2 The Lower Silurian rocks. (Geology of central Wisconsin.) Geology of "Wisconsin, survey of 

1873-1879, vol. 2,1877, p. 529. 

*0p.oit.,p.634. «Op.cit,p.636. <>0p.cit.,p.642. 6 Op. cit., p. 545.
WALCOTT.] SUMMARY UPPER MISSISSIPPI VALLEY. 333

In the Mississippi Valley, in southwestern Wisconsin, Mr. Moses 

Strong estimated the total thickness of the Potsdam at 800 to 1,000 feet, 

the inequalities in the surface of the underlying Archean rocks being 

the principal source of its variation.1 The formation is composed almost entirely of sandstone. The only exception to this is the stratum 

of inagnesiau limestone and shale found in the upper part of the formation.

The strata of the formation are usually composed of fine siliceous sauel, generally 

in small, rounded, water-worn grains of almost every color, the most frequent being 

the various shades of yellow and red, sometimes green, and often snow white. The 

strata vary greatly in consistency, and in different localities the same stratum may 

present different degrees of hardness. Some of the layers, and especially the white 

ones, are frequently almost as compact as quartzite, and from this all degrees are 

found, to a loose, friable sand that crumbles in the hand. * * * The stratification 

of the Potsdam is very regular and even, and the beds usually lie in a nearly horizontal position over large tracts of country. Indeed, so little do they deviate from 

an apparent level that the dip can not be distinguished by the eye, but only by a 

careful measurement. The dip is usually to the northwest, and seldom exceeds 8 or 

10 feet to the mile, but more frequently it is less.2

The most highly fossiliferous portion of the formation occurs in western Wisconsin. The formation is divided in the lower St. Croix district, by Mr. L. C. Wooster, into four horizons, as follows : 3 (1) "Eau 

Claire grit; (2) Eau Claire trilobite beds; (3) Hudson trilobite beds, 

and (4) line of junction with the Lower Magnesian limestone." In this 

region it borders upon the rnetamorphic and igneous rocks to the north 

and east, and touches the Lower Magnesian limestone on the south and 

west.

The four horizons mentioned are described as follows:

The Eau Claire grit, exposed at the mouth of Ean Claire River, is a very coarse sandstone, with Scolithus tubes in one or two of the layers. The rock is so coarse that it 

has been termed a conglomerate, not without reason.

The Eau Claire trilobite beds are characterized by several species of trilobites not 

found at any other horizon, and also by being the lower limit at which brachiopods 

were found in the sandstone. These beds likewise mark the lower limit of calcareous matter in the formation.

The Hudson trilobite beds lie at the best defined horizon in the sandstone. These 

beds lie in close relationship to and between the Lower Calcareous band and the layers 

which are richest in green sand, and thus can not well be mistaken. * * * The 

shaly layers below the trilobite beds are intensely green from the presence of green 

sand (a variety of glauconite), which, so far as known, is true of no other horizon.

The line of junction with the Lower Magnesian limestone may, in nearly every instance, 

be recognized by the heavy brecciated beds of limestone just above. But this charactor may fail in the extreme southeastern border of the district, where it is possible 

that beds of sandstone are iuterstratified with the lower layers of the Lower Maguesian limestone, as in eastern Wisconsin.4

1 Geological formations. (Geology of the Mississippi regions north of the Wisconsin River.) Geology of Wisconsin, survey of 1873-1879, vol.4,1882,p.45.

2 Op. cit, pp. 39,40.

8 Detailed geology: [Geology of the lower St. Crox district.] Geology of "Wisconsin, survey of 1873- 

1879, vo.. 4,1882, p. 109. 

4 Op. cit., p. 110.
334 THE CAMBRIAN. [BULL.81.

Another horizon is mentioned in which lies the Upper Calcareous 

band, possibly marking the horizon of the Mendota limestone of central Wisconsin.

At no one point in the district is the entire formation exposed, and so, to obtain 

the entire thickness from the Lower Magnesian limestone to the granite below, the 

sum of the thicknesses of the subdivisions is taken:

Feet. 

From the Lower Magnesian to the Hudson trilobite bed....... 200

From the Hudson trilobite bed to the Eau Claire Trilobite bed . 200 

From the Eau Claire Trilobite bed to the Eau Claire grit...... 240

From the Eau Claire grit to the granite (at Eau Claire), estimated :.................................................... 100

Total.................................................. 740

The last division is probably much thicker to the south and west, making the 

thickness of the formation range to 800 and 1,000 feet. 1

The report of Prof. Wooster contains details of numerous local sections that show the lithologic and paleontologic characters of the formation.

The outcrops in Iowa are the continuation of those of southwestern 

Wisconsin; and very little is added to the knowledge of the formation 

in Minnesota, where it is called the St. Croix sandstone by Prof. N. H. 

Winchell. At Winona and Stockton there are about 303 feet of the 

formation exposed.2

A generalized section in Minnesota, as given by Prof. Winchell,3 is 

as follows:

Feet.

! Jordan sandstone..................75-100= Madison of Wisconsin. 

St. Lawrence limestone............ 0- 30 = Mendota of Wisconsin. 

Dresbach sandstone and shales.... 200. 

Shales-.........'............................. (?)

CANADIAN EXTENSION.

In the account of a deep boring at Rosenfeld Station, on the Canadian 

Pacific Eailway, Dr. G. M. Dawson correlates the upper portion of the 

section with the Maquoketa shales, beneath which occurs the Galena 

limestone, passing below into Trenton and then to the St. Peters sandstone. Below this, before reaching the granite, there are 110 feet of 

dark red, reddish and greenish, bluish and grayish shales, passing below into red shales, which are referred with doubt to the Lower Magne. 

sian limestone.4 Whether the St. Croix sandstone is represented in 

this section can not be determined in the absence of paleontologic evidence, but it is not improbable that the horizon of the St. Croix and the 

Lower Magnesian limestone of the Minnesota section may both be included between the limestone and the granite at the bottom of the well.

 Op. cit.,p. 112. 

2The Geology of Minnesota, vol. 1 of the final report. 1884, p. 258.

3 Winchell, N. H.: 14th Ann. Eep. Minn. Geol. and Nat. Hist. Survey, 1886, pp. 325-337.

4 On certain borings in Manitoba and the North west Territory. KoyalSoc. Canada, Proo. and Trans., 

vol. 4, section 4, 1887, p. 86.
WALCOTT.J SUMMARY LAKE SUPERIOR SANDSTONE. 335

' LAKE SUPERIOR SANDSTONE.

The earlier geologists speak of the Keweenawau series and the horizontal Lake Superior sandstones as forming part of the same terrane, 

and this view has been sustained by some more recent writers. Many 

others, however, have held the view that the horizontal sandstones 

were the equivalents of the fossiliferous sandstones beneath the Magnesian limestone of central Wisconsin, and that the sandstones of the 

Keweenawan series were unconformably subjacent to the horizdntal 

sandstones. Prof. R. D. Irving, taking the latter view, says :

The constant horizontality of the sandstone series, its restriction to low levels, 

the actual unconformity visible in Douglas County, the proximity of the horizontal 

sandstones to the enormously thick perpendicular fraguiental beds of the Montreal 

Kiver, and the relations of the two series ou the St. Louis appear to amount to demonstration. In the Thunder Bay region the Canada geologists have proved a similar 

nonconformity, and Sir William Logan's arguments would seem to show that the 

same is true for the southeastern shore of the lake. That it may at times be difficult 

to tell whether we have to do with the Keweenawan or the newer sandstones is undoubtedly true in some of those cases where the Keweenawan beds have a low inclination, but such cases of difficulty are rare. 1

Of the relation of the horizontal sandstones on the north side of the 

Wisconsin pre-Cambrian area and the fossiliferous sandstone ou the 

southern side he says : 2

An absolute proof of their exact relations is wanting, because nowhere as yet have 

the two been traced into each other. Judging from the low altitude above the lake 

to which the Lake Superior sandstone has been seen reaching, it appears improbable 

that any connection ever existed between the two formations in the Wisconsin-Minnesota region. * * * It appears, on the whole, that the evidence is all in favor of 

an approximate equivalency of the Lake Superior and Mississippi Valley Potsdam 

sandstones. It seems probable to me, with my present knowledge of the facts, that 

they were deposited in always disconnected basins, and that their'sharply contrasted 

lithological peculiarities are to be explained by corresponding differences in the ancient rocks from whose ruins they are built.

Under the designations of the " Eastern sandstone n and " Western 

sandstone" Prof. Irving describes the horizontal sandstones of the 

south shore of Lake Superior. By the " Eastern sandstone" he means 

sandstone that fills the valley between the Keweenaw or main trap 

range of Michigan and the so-called south range. The eastern end of 

this depression is occupied by the waters of Keweenaw Bay. The sandstones skirt the shores in a band varying in breadth from a few rods to 

1 or 2 miles, the older crystalline rocks occasionally reaching down 

to the lake. These conditions prevail as far eastward as Marquette, 

beyond which point to the eastward sandstone forms all of the shore 

cliffs as far as the Sault.3

1 Geological Structure of Northern Wisconsin. fGoneral geology of the Lake Superior BegioTi. 

Geology of Wis., Survey of 1873-79, vol. 3, 1880, p. 23. 

Z 0p.cit.,pp. 24, 25. 

3 The Copper-bearing Rocks of Lake Superior, TJ. S. Geol. Surv., Monograph, vol. 5,1883, p. 351.
336 THE CAMBRIAN. [BULL. 81.

The characters of the sandstone and its relation to the superjacent 

rock are stated as follows:

The sandstones of the Keweenaw Bay and its vicinity, and eastward thence to White 

Fish River, are reddish and often highly argillaceous. At White Fish River the red 

sandstone is overlain by a light-colored sandstone, which is in turn succeeded by a 

magnesian limestone, in which are casts of Pleurotomaria. This limestone is the 

Lower Magnesian of the Wisconsin reports and the Calciferous sandrock of the Eastern States. That it is succeeded in regular order by the fossiliferous limestones of 

the Trenton, Cincinnati, and Niagara groups was long since shown, and has been 

demonstrated anew of late years by the labors of the geological surveyors of Wisconsin 

and Michigan. There thus seems little room for doubt as to the correctness of the 

view held for years by a succession of geological workers in the Lake Superior region 

from Owen to Rominger, viz, that in the Eastern sandstone we have to do with the 

same formation, or with its downward continuation, as the fossiliferous Cambrian 

sandstone which, in the Mississippi Valley, forms the base of the Paleozoic column. 1

The Western sandstones, or those of the Apostle Islands and the adjoining coast of Bayfield, Douglas, and Pine Counties, are composed of 

a horizontally placed sandstone, closely resembling in character the 

Eastern sandstone of Keweenaw Point. The exposures of the sandstone are almost entirely restricted to the vicinity of the shores of the 

lake, on the mainland, and the Apostle Islands, and have never been 

seen reaching more than 50 feet above the lake level. Farther west, 

however, in Douglas County, the horizontal sandstone reaches to 360 

feet above the lake.2 Prof. Irving states that the prevailing color of 

this rock is some shade of red, from bright brick red to a brownish 

red or purplish red. Pinkish, straw-colored, and even nearly pure 

white varieties occur, either blotching the ordinary red rock in small 

patches, or occurring in layers from an inch to 2 or 3 feet in thickness. 

A section typical of many of the cliff exposures of the lake shore is as 

follows:

Ft. In. 

Red marly clay (Quaternary) ................................ 5 0

Shaly sandstone, in layers from one-fourth to one-half inch thick; 

light reddish to brown, medium-grained, chiefly made up of 

subangular quartz grains................................... 4 9

Compact sandstone ........................ ............... 2 0

Shaly sandstone ............................................. 0 3

Compact sandstone; pinkish and-moderately coarse-grained, 

cMefly made up of quartz grains, but many white clay spots, 

indicating the decomposed feldspar......................... 2 0

14 0

The shaly and massive layers are, however, not constant, and either will grade 

into the other in a short distance, the shaly kinds being often merely a result of 

weathering. Often the massive layers have a thickness of 5 feet and upwards, and 

lie together in considerable thicknesses without intervening thin-laminated seams. 

In many places round bunches of red clay, from an inch to several feet in diameter, are 

seen imbedded in the massive sandstone. In other cases the clay lies in limited and

1 Op. cit., pp. 351, 352.

2 The Lake Superior Sandstone. [Geology of the Eastern Lake Superior District.] Geol. Wisconsin, vol. 3,1880, p. 207.
SUMMARY LAKE SUPERIOR SANDSTONE. 337

very irregular seams, from a fraction of an inch to several inches thick. Some of the 

round clay patches appear as if formed by the decomposition of granite or gneiss 

bowlders imbedded in the sandstone at the time of its formation. 1

In speaking of these same sandstones Mr. B. T. Sweet says:

In regard to the age of the Lake Superior sandstones, but very little in deed can be 

learned in the western Lake Superior district. So far as my observations have extended, the sandstones are absolutely devoid of organic remains. They are removed 

many miles and are separated by intervening older formations from the unmistakable Lower Silurian strata.

5 He considers it has been conclusively shown that the sandstones are 

of more recent age than the Keweenawan strata.2

Dr. C. Eominger concluded from his studies of the Lake Superior 

sandstone that its Lower Silurian age was unequivocally proved by its 

stratigraphic position. In its whole extent it is visibly overlaid by calcareous ledges containing fossils peculiar to the Oalciferous formation, 

or, in other cases, by the Trenton limestone. He describes the sandstone east of the Copper Range of the Keweenaw Point and divides it 

into two sections, an upper and a lower one. He says:

The upper section is composed of light-colored, almost white, sandstones of generally 

soft, friable nature. The lower section is intensely red colored by iron pigment, and 

contains varioushard, compact ledges, which are valuable building stones. WeSt of 

Marquette only the lower section of the group is developed; east of it the heights 

are formed by the upper division; the lower has exclusive possession of the shore as 

far as Grand Island Bay. East of Grand Island Bay the upper division sinks down 

to the level of the water, and only in limited spots the lower red-colored strata come 

to the surface. 3

On Laughing Whitefish Eiver a section as determined by Dr. Eominger is as follows in ascending order:

Feet. 

No. 1. Alternations of thin-bedded, hard, often micaceous sandstone slabs,

with arenaceous shales (as exposed).............................. 25

No. 2. A fine-grained, more or less argillaceous red sandstone in layers of

1 to 3 feet in thickness with seams of red shales .................. ' 12

No. 3. A hard, coarser-grained, red, or speckled sandstone in heavy ledges up 

to 4 and 5 feet in thickness, amounting in the aggregate to 15 or 20 

feet............................................................. 15-20

No. 4. Light-colored, middling soft sandstone in thick layers with seams of 

quartz pebbles, followed by a few feet of a dark and coarse conglomerate ; thickness not accurately ascertained ...................... 00

No. 5. A series of tbin-bedded, soft, whitish sandstones, each layer separated

from the other by a narrow seam of bluish shale.................. 75-100

No. 6. Massive soft white sandrock, projecting in vertical walls ........... 50

Directly above this, strata of the Calciferous sandrock occur with 

casts of Pleurotomaria.4

This section of Dr. Eominger's is not altogether complete, but it shows 

conclusively that the Lake Superior sandstone in the vicinity of Mar1 Lake Superior sandstone [Geology of the Western Lake Superior district]. Geology of Wisconsin, 

Survey of 1873-'79, vol. 3, 1880, pp. 208, 209. ' 

"Op. cit., pp. 351,352.

8 Paleozoic Rocks. Geol. Survey Michigan, "Upper Peninsula, 1809-1873, vol. 1, pt. 3,1873, pp. 80-82. 

«0p. cit., pp. 88-90.

Bull. 81 22
338 THE CAMBRIAN. [BULL. 81.

quette, or east of Marquette, occupies the exact stratigraphic position of 

the fossiliferous St. Croix or "Potsdam " sandstone of Wisconsin. The 

description of the character and geologic equivalency of the sandstones 

of the south shore of Lake Superior as given by Prof. Chamberlin accords with the view I had formed from the study of the literature pertaining to the subject. Although not considering it proved that the two 

sandstones are exactly contemporaneous, 1 think that for all practical 

geological classification they may be considered-equivalent deposits. 

This view is so well expressed by Prof. Chamberlin that it is here 

quoted:

Lake Superior sandstone. The sandstones on the southern side of the Archean Island are light-colored, being mainly yellow or white, varyiug locally to pink, brown, 

and green. They are nowhere bodily dark. An easy explanation of this is found in 

the fact that they were derived from the light-colored quarlzose and granitic rocks 

of the southern face of the land. But passing around to the Lake Superior Basin on 

the northern side of the island, where erosion preyed upon the iron-bearing members 

of the Hurouian series, and more especially upon the traps, sandstones, and shales of 

the copper-bearing series, the resulting beds are not only reddish brown in color, but 

contain a notable ingredient of iron and of shaly material derived from those formations. Indeed the deposit bears a very close external resemblance to the sandstones 

of the Keweenawan series, and the two have been considered as identical by able 

geologists.

Concerning the distinctness of the two formations we entertain no doubtful opinion. The Potsdam sandstone is habitually horizontal, while the Keweenawan is 

tilted, indicating that the latter partook of a general stratigrapical movement which 

did not affect the former, which, considering the attendant circumstances, is equivalent to saying that the horizontal sandstones were not then in existence. ( The observations of Mr. Sweet in Douglas County are further proof of this. 1 The Potsdam 

sandstone there abuts unconformably against the Keweenawan traps and contaics 

pebbles derived from them, showing not only that they were earlier formed but that 

they were tilted and extensively eroded at the time the horizontal sandstones were 

formed. The local disturbance-of the latter does not vitiate the force of the evidence 

when critically considered. Similar phenomena are presented along the southeastern 

face of the promontory of Keweenaw Point.2

Besides these stratigraphical evidences of distinctness, the microscopical observations of Prof. Irving and the chemical analyses of Mr. Sweet show an important constitutional distinction between them.3 Whereas the Keweenawan sandstones are 

largely nonquartzose, the horizontal beds are highly quartziferous.

As the latter are traced eastward along the south shore of Lake Superior they are 

found, according to Dr. Eominger, to be inter stratified with and graduated into the 

light-colored sandstones whicji prevail in the eastern portion of the upper peninsula 

of Michigan, and which are traceable into direct continuity with the light-colored 

sandstones of Wisconsin. The same geologist (as also Foster and Whituey) is authority for the statement that in the Keweenaw Valley Silurian limestone overlies this 

sandstone.

The southern light-colored sandstones, like their northern equivalents, abut un1 Geol. Surv. Wis., vol. 3, pp. 340-347; also 350-352.

2 This has recently been denied by Dr. M. E. Wadsworth, but more recent examination by experienced observers shows his discussion of the subject to be more pronunciative than trustworthy. Bnl. 

letin of the Museum of Comparative Zoology, at Harvard College, GrflOl. Series, YOl. 1. IJlG filtf/8 Jfl 

detail as determined by the later observations will be found in Prof. Irving's forthcoming report on 

the copper-bearing series.

3 Geol. Wis., voL 3, pp. 15 and 350, and microscopical PI. xix A.
WALCOTT.] SUMMARY MISSOURI. 339

conformably against eroded cliffs of Keweenawan rock. At St. Croix Falls lightcolored Potsdam sandstone containing characteristic fossils reposes unconformably 

upon and against Keweenawau cliffs and occupies depressions and valleys formed 

through its erosion. Conglomerates derived from it mark the junction of the two 

formations and contain Potsdam fossils. Hand specimens may be obtained, having 

Keweenawan rock for one side and Potsdam sandstone containing shells of Lingulepis 

pinnaformia for the other. The phenomena absolutely forbid any explanation based 

on faulting or intrusion

North of St. Croix Falls the same strata, sustaining a like stratigraphical relationship (though not seen in actual unconformable contact) may be traced more than half 

way across the Keweenawan series. Passing the remainder of the interval to Lake 

Superior the horizontal red sandstones are found abutting, in similar uuconformable 

contact, against the eroded Keweenawan series as above stated. The accompanying 

section illustrates the general relationship, but only a careful study of the details 

can make clear the full force of the evidence.

When to these considerations there are added others less susceptible of brief statement, to which we are here confined, it appears that the distinctness of the horizontal 

Lake Superior sandstone from that of the Keweenawan system and the correctness of 

its reference to the Potsdam series is sustained by a weight of evidence that would not 

be seriously questioned but for complications with what we deem the misinterpretations of other geological features of the Lake Superior region. The modifications 

which the formation assumes in that region are precisely those which its method of 

derivation demands. 1

CANADIAN EXTENSION.

On the geological map of the Dominion of Canada, published in 

1882, the Nepigon series of rocks is colored Cambrian, both on the 

shores of Lake Superior and about Lake Nepigon. This is in accordance with the views of Dr. A. B. 0. Selwyn.

MISSOURI.

The Cambrian rocks in Missouri occur in the southwestern portion of 

the State, about the Ozark Uplift. As far as known they are of Upper 

Cambrian age and consist of a sandstone that occurs beneath the third 

magnesian limestone, or Calciferous, and the fourth magnesian limestone of the Missouri survey, beneath which, according to Prof. G-. C. 

Broadhead, there are other arenaceous and calcareous beds.

The third sandstone is doubtfully identified by Mr. F. B. Meek, in 

Miller County, as 6 feet of white sandstone, composed of rounded grains 

of quartz cemented in part by calcareous matter. Subjacent to this 

there are 27 feet of hard gray and light flesh-colored magnesian limestones in rugged, irregular beds from 5 to 8 feet in thickness.2 In 

Morgan County the third sandstone is known to occur at a few localities, where it varies from 25 to 30.feet in thickness. The subjacent fourth 

magnesian limestone forms a bluff 150 feet high above the Osage Eiver 

in the southwestern part of the county.3

1 General geology. Historical geology. Paleozoic era. Geology of Wisconsin, survey of 1873-1879, 

vol. 1,1883, pp. 122-124.

* Reports on the Geological Surrey of the State of Missouri, 1865-1871, 1873, p. 127. 

»0p. oit, p. 148.
340 THE CAMBRIAN. [BULL. 81.

In Madison, St. Francois, and Iron Counties, Prof. G. C. Broadhead 

found beneath the third magnesian limestone the following downward 

succession:

(3) Siliceous or grit-stone bed, with intercalated magnesian limestone.

(2) Marble beds.

(1) Sandstones, conglomerates, and shales.

In No. 3 Lingulella lamborni Meek has been found. The marble 

beds or Eo. 2 appear to be confined to the southwest quarter of Madison 

and the central and northern parts of Iron and extend into Reynolds 

County. The greatest thickness is not over 30 feet, and they are not 

always present.

No. 1 is confined chiefly to the northern part of Iron and Madison, extending to St. 

Francois. The entire thickness of this as well as the regular order of its various 

beds is rather difficult to arrive at. But we find both in Iron and Madison Counties 

coarse conglomerates resting on granite and porphyry. We also find sandstones, 

 which are sometimes very coarse, and at other times fine-grained, resting on conglomerates. We also find shale or slate beds reposing on granite and iinderlyiug sandstone. Similar shale beds are also intercalated with the sandstone. In the neighborhood of Mine La Motte this sandstone reaches to over 100 feet in thickness, and 

is also found to be the Jowest rock directly resting on the granite. Borings with 

diamond drill on the Mine La Motte property indicate magnesiau limestone, with some 

siliceous beds, 80 feet; sandstone, 63 feet; granite.

On St. Francois Eiver, in Madison County, these lower sandstones rest directly on 

the granite and are unaltered; on Twelve-Mile Creek, Madison County, the marble 

beds and sandstones rest unaltered on the porphyry, and on Big Creek, Iron County, 

heavy beds of unaltered magnesian limestone rest directly on the porphyry. 1

At the deep well of the St. Louis County insane asylum, beneath the 

third magnesian limestone, the drill passed through, going down 

98 feet of third sandstone.

384 feet of fourth magnesian limestone. 

54 feet of Potsdam sandstone.

At the base of the sandstone it entered what was supposed to be 

granite, although the line of demarkation between the sandstone and 

the granite was not well defined.2

In the descriptive geology of Madison County Prof. Broadhead states 

that the sedimentary rocks were deposited across the valleys between 

the mountains and the hills (that is, of the old pre-Cambrian land surface). The order of deposition, commencing at the oldest, is 

(1) Sandstones, conglomerates, and shales.

(2) Marble beds.

(3) Grit-stone beds and rough beds of magnesian limestone.

Above this comes the magnesian limestone referred to the Calciferous.

In the vicinity of Fredericktown there is a series of grits between the 

grit-stone beds and the superjacent magnesian limestone in which Lingulella lamborni has been found. It is stated that in tiie lower portion

1 Geological Survey Missouri, including field work of 1873-1874, vol. 1,187*, pp.31,32. 

"Op.oit., p.32.
WALCOTT.J SUMMARY ADIRONDACK SUB-PROVINCE. 341

of the magnesian limestone Lingula lamborni, Orthoceras, a turbinated 

Gasteropod, and a coral, resembling in cross-section a Zaphrentis, were 

observed. He states that probably this magnesian limestone can also 

be included in the Potsdam zone.1 This includes all the limestones up 

to the base of the recognized third rnaguesian limestone.

A more detailed account of this lower marble belt is given by the 

same writer in a description of the marbles of southeastern Missouri. 

The most typical section is that of t<he northern part of Madison County, 

which is summed up as follows:

(1) Magnesian limestone.

(2) Eighteen feet of thick beds of siliceous dolomite and thin shaly limestone, 

with Lingula lambomi.

(3) Twenty-three feet of gritty dolomite.

(4) Five to thirty feet of marble.

(5) Five to forty feet (as much as 90 feet near Mine La Motte) of sandstone.

(6) A few feet of slaty sandstone resting on granite.

The presence of Lingula lamlorni in beds a little above the marble will certainly 

assign the marble beds to the Potsdam group.9

EASTERN BORDER OR ADIRONDACK SUB-PROVINCE AND ITS CANADIAN EXTENSION.

The geographic distribution of the Potsdam terrane about the Adirondacks is delineated on the geological map of New York accompanying the final report in 1842, and that of the Canadian extension on the 

small map accompanying the 1863 report of Sir W. E. Logan and the 

large map of Messrs. Logan and Hall, published in 1866.3

On the western side of the Adirondacks the outcropping of the sandstone is first seen in the northern part of Lewis County, where it rests 

unconformably upon the subjacent Archean rocks and passes above 

into the calcareous layers of the Calciferous formation. The outcrop 

broadens to the north in Jefferson and St. Lawrence Counties and 

extends around the northern side of the Adirondack area through 

Franklin and Clinton Counties to Lake Ohamplain. The exposures on 

the eastern side are more or less interrupted, and rarely occur upon the 

eastern side of the lake in Vermont, except in Addison and Rutland 

Counties. On the southwestern side outcrops occur in Washington, 

Warren, and Saratoga Counties.

The Franklin and Clinton County area extends across the boundary 

into Canada, forming quite an extended exposure within the triangle 

formed by the St. Lawrence and the St. John's Eivers and the boundary, and at one point it crosses to the north of the St. Lawrence Eiver. 

From St. Lawrence County the sandstone crosses the river and extends 

along the western side of the Ottawa Basin.

1 Geological Survey Missouri, including field work of 3873-1874, vol. 1,1874, pp. 357, 358.

2 Marble of Southeast Missouri. Kansas City Review, vol. 5,1882, pp. 525,526.

8 Geological map of Canada and part of the United States from Hudson's Bay to Virginia and from 

the Missouri River to Newfoundland. Montreal, I860.
342 THE CAMBRIAN. [BULL.SL

The typical sections are those of Potsdam, in St. Lawrence County; 

Chateaugay Chasm, in Franklin County; Au Sable Chasm, in Essex 

County, and Greenfield, in Saratoga County, in the State of New York, 

and Heininingford, in Canada.

Section at Potsdam. At the type locality of the terrane at Potsdam, 

in St. Lawrence County, there are but 60 or 70 feet of the rock exposed. 

It occurs in layers from an inch or two in thickness up to 2 feet, and 

the general color of the mass is yellowish brown to reddish brown, particularly the latter color in the thicker layers.

Section at Chateaugay Chasm. At Chateaugay Chasm, Franklin 

County, one of the best sections of the formation upon the northern 

slopes of the Adirondacks is exposed. I studied it in 1888 and found 

that 5 miles south of the Ogdensburg and Lake Champlain Eailway 

the pre-Cambrian rocks are to be seen on the hills west of the river and 

in a few small outcrops about one-half a mile to the north. It is a 

bedded, reddish gueissoid and hornblendic rock, probably of Algonkian 

age. Nearly one mile south of these outcrops the Potsdam sandstone 

appears in the bed of the river, with a northwest dip of about 3°. The 

exposures increase rapidly in thickness, and bluffs from 50 to 75 feet 

in height, formed of evenly-bedded layers, rise above the water. The 

river has worn a canon through these beds for three-quarters of a mile 

down to a mill and pond, where the cliffs break away, and the strata, 

losing their dip, continue to the south, in nearly horizontal beds, to the 

crossing of the railroad embankment.

The fall in the river bed is rapid, and at the High Falls of the Chateaugay Chasm a bluff of 125 feet rises from the foot of the fall. The 

lower 35 feet of the section is formed of coarse reddish and gray sandstone in massive layers. At the Narrows, three fourths of a mile farther down the stream, the lower beds are 75 feet in thickness and pass 

into massive bedded grayish and buff-colored sandstones that break up 

into thinner layers on exposure to the action of the weather. Many of 

the massive beds are made up of irregular cross-bedded layers: this is 

best seen about a mile below the falls. The strata below assume a southwesterly dip of 2° to 3°, which carries the entire sandstone formation beneath a hard light gray sandstone a little north of the mouth of the chasm. 

One hundred and fifty feet of sandstone, not included in the section 

above the railroad embankment, is exposed in the chasm and 25 

feet of the upper beds occur below the mouth of the chasm; This gives 

a total thickness of 250 feet of sandstone as the known thickness of 

the Chateaugay section. To this there is to be added an unknown 

amount at the base and 25 feet of passage beds between the upper sandstone and Calciferous sandrock, to be seen just above the entrance of 

Marble Biverinto the Chateaugay.
WALCOTT.] SUMMARY ADIRONDACK SUB-PROVINCE. 343

SECTION.

« (From the base upward.)

Feot.

(1) Coarse sandstone with occasional layers of conglomerate near the base...... 75

Color reddish brown near the base, buff, gray, and buff and gray, spotted 

with grains of reddish brown sand. Texture compact ami hard, with 

bands of a soft friable nature.

(2) Massive bedded, grayish and buff, rather coarse sandstone, many of the layers cross-bedded ........................................................ 150

(3) Compact, fiue-grained white sandstone, some of the layers of which are discolored and broken by small reddish brown cavities. Lingulepis aouminala 

occurs in the upper portion, and 10 feet higher up Ophileta compacta, 

Dikelocephalm sp. ?, Pttjohaspis sp. ? ...................................... 25

The stratigrapbic exposures are not continuous, the section being 

broken in places by concealment under the drift. Nos. 1 and 2 are 

fairly well connected by lithologic features and No. 3 rests on typical 

strata of No. 2, only a short distance intervening between the outcrops. 

No. 3 is well shown on Marble River one mile southeast of the Chateaugay Chasm, and the Calciferous sandrock is shown a little farther 

down the stream. The species found in the upper part of No. 3 are 

identical with those found in the limestones of the Upper Cambrian in 

Saratoga County, New York and fully prove that the fauna of the 

Potsdam sandstone is the same as that of the St. Croix sandstones of 

Wisconsin.

Section in Hemmingford. To the northeast of Chateaugay, across 

the boundary, in Hemmingford, Canada, a section of the sandstone 

according to Sir W. E. Logan, is 540 feet in thickness. On the south 

side of Hemmingford Mountain about 180 feet of a coarse gray 

sandstone are visible, in some parts constituting a conglomerate, with 

rounded pebbles of white quartz, varying in diameter from an eighth 

to three-quarters of an inch, while in some parts of the rock there are 

thinly disseminated flat pieces of black or green shale 1 or 2 inches 

in diameter by an eighth of an inch thick. The general color of the 

rock is gray, but greenish and reddish beds occur, and the three colors sometimes follow one another in thin stripes with various alternations. Above the strata of the ravine the hill contains about 120 feet 

of gray sandstone, the lower half of which is rather coarse grained, and 

below the same strata 240 feet. Neither the base nor the summit of 

the sandstone was observed.1 Farther to the north along the shore of 

the St. Lawrence occur the celebrated fossil track localities described 

by Logan.

Section at Keeseville and in Au Sable Chasm. About one-quarter of a 

mile above the village of Keeseville, on the Au Sable Eiver, a rounded 

boss of granite shows on the south bank. Nearly 400 feet lower down 

the stream, on the opposite side, an evenly bedded and cross-bedded

1 Geological Survey of Canada: Report of Progress from its commencement to 1863. Montreal, 1863, 

p. 88.
344 THE CAMBRIAN. [BULL.81.

compact gray sandstone occurs, lying in nearly horizontal beds. Lower 

down they dip 3° to 5° to the northeast. This dip increases to 7° to 

8° at the iron bridge. Following across the strike down the stream to 

where the beds are horizontal, above the entrance to the Cbasin, the 

measured section shows 333 feet in thickness from near the granite to 

the highest beds observed.

The section as measured from the mouth of the Au Sable Chasm to 

the summit beds above the fault is as follows:

SECTION.

Feet.

(1) Compact, fine-grained, steel-gray, bnff, and light gray sandstone, in layers

from 6 inches to 5 feet in thickness (20 layers).......................... 45

Strike N. 30° E. Dip. 5° E.

(2) Massive layers, light gray, fine-grained sandstone, very hard, breaking np

into thin layers, £ to 3 inches thick.................................... 6

(3) Compact, gray sandstone in three layers; 1 foot 5 inches, 1 foot 6 inches, 2

feet 1 inch ............................................................ 5

(4) Light gray and buff sandstone, three layers............................... 4 '6

(5) Light gray compact sandstone, with Lingulepis aoiiminata, Conrad......... 1

Strike N. 30° E. Dip 5° E., at foot of rapids.

(6) Light gray, fine-grained, compact sandstone, in layers varying from 6

inches to 18 inches in thickness ........................................ 6

(7) Of the same general character as 6, in massive layers, breaking up into thin 

layers on exposure. Occasional layers contain many small, flat concretions of clay shale and also fragments of Lingulepis. At 34 feet from 

the base Hyolithesprimordialis ? and Lingulepis acuminata occur near the 

boat-landing in the Chasm. Thirty-five feet higher up in the same light 

gray compact sandstone L. antiqua occurs in association with Ptychoparia 

minuta ................................................................ 117

At this line a fault breaks the section with a down-throw to the northeast. The river and Chasm follow the fault from the Elbow to the 

Devil's Oven, where the section is taken up again.

(1) Massive layers of light gray, hard, compact sandstone. Prof R. P. Whitfield

found at this horizon Palceacmcea typica, Ptychoparia minuta .............. 30

(2) Evenly bedded gray, buff, and yellowish sandstone, hard, compact and in

layers 1 to 4 feet in thickness............................................ 165

(3) Thinner bedded gray and buff sandstone, with Protichnites tracks above the

mill-dam and above the bridge at Birmingham........................... 45

Strike NE. ; dip 5° SE.

Ripple marks are very numerous and Lingulepis acuminata is abundant 15 feet 

above the Protichnites bed, and extends about 25 feet to the top of the section. 

Some of the layers are a little calcareous and full of annelid trails and borings.

Estimating the amount of repetition of strata in the two sections 

there remains a lower series of 210 feet, and an upper of 140 feet, or a 

total thickness of 350 feet with the summit and base of the formation 

unseen.

Section at Whitehall. There is a fine section exposed at Whitehall,

New York, that serves to correlate the sections of1 Ohafaaugay ana 

Au Sable Chasm. At the former the upper fauna is present and at 

Au Sable Chasm the Ptychoparia minuta subfauua. At Whitehall the
WALCOTT.] SUMMARY ADIRONDACK SUB-PROVINCE. 345

upper fauna occurs in the upper portion of No. 17 of the following section and the lower in the lower part of No. 15. This is the relative 

position of the same subfaunas in the Wisconsin section. 

Section beginning below lower lock of canal at Whitehall:

Ft. In.

(1) Massive bedded, compact, dark steel gray sandstone, almost a quartzite. 25 0

(2) Dark clay shale........................................................ 0 C

(3) Bluish gray, brecciated limestone ...................................... 0 6

(4) Fine grained, compact, steel gray limestone............................ 1 0

(5) Compact, arenaceous limestone ......................................... 3 0

(6) Compact, fine grained, steel gray sandstone in layers of 6 inches to 3 feet. 

Partings of coarser sandstone and small, flattened clay concretions 

occur, also streaks of light-colored sandstone in the layers, and crossbedding is of common occurrence..........»........................ 14 5

Annelid trails on the surface of the layers.

Strike N. 20° E.; dip 6° to 8° E.

(7) Calciferous sandstone in one layer..................................... 2 -7

( 8) Fine grained, compact, steel gray sandstone........................... 20 0

( 9) Thin bedded sandstone and clay shale................................. 1 3

(10) Compact, gray and purplish, fine grained sandstone, streaked with dark

sandstone and shalymatter; slightly calcareous in places .._._..... 16 6

(11) Dark gray calciferous layers, weathering to a reddish brown sandstone.. 2 0 

Annelid trails and borings.

(12) Gray, compact sandstone..............................I............... 1 3

(13) Dark gray, calciferous layers, weathering to a reddish brown sandstone. 1 4 

Annelid trails and borings.

(14) Hard, compact, gray sandstone, in evenly bedded layers 6 inches to 3 feet 

in thickness of the division of the typical Potsdam sandstone. Summit near crossing of private roadway................................ 59 8

(15) Sandstones similar to 14, but with few alternating calcareous layers ; the 

calcareous matter decomposing and leaving streaks of reddish and 

brown rocks in the layers........................................... 113 0

Ripple marks occur on the surface of many layers and annelid 

trails on the calcareous strata, About 30 feet up found Palosaomcea 

typica, H. and W.

Strike 25° E.; dip 10° E.

The light gray compact limestone, with the little flattened concretions of clay and the cross-bedding, give this portion of the section a 

striking resemblance to that of the upper 150 feet of the Keeseville 

section.

(16) Lead colored calciferous sandstone, weathering rough.................. 0 5

(17) Alternating, gray, compact, fine grained sandstone, reddish coarse sandstone and finer calcareous sandy layers. Lingulepis aouminata and 

Ptydhoparia sp ? occur in the upper layers, about 40 feet up.......... 70 0

332 5

Calciferous. "-

(18) Calciferous sandstone with a massive bedded light gray compact sandatone; at top 10 feet thick.......................................... 40

The upper 30 feet of 17 and all of 18 may be considered as the passage beds to the calciferous sandstone above.

(1) Lead colored, massive bedded, calciferous sandstone .................... 230

(2) Lead colored, brecciated limestone overlain by a compact light gray limestone ........................................ . ... ......... 20

290
346 THE CAMBKIAN. [BULL. 81.

Section at Saratoga. The section, as determined north and west of 

Saratoga Springs, and north as far as Corinth, New York, has, at the 

base, about 200 feet of evenly bedded, compact, grayish to yellowish 

colored sandstone, that rests unconforniably against or upon spurs or 

ridges of pre-Canibrian gneiss. Including the upper beds of sandstone, the section 3 miles north of Saratoga village gives in ascending 

order:

Feet.

(1) Sandstone ................................................ 40

(2) Oolitic limestone.......................................... 30

(3) Dark gray, evenly bedded limestone........................ 50

(4) Unfossiliferous, impure, compact, more or less siliceous limestone .................................................... 95

(5) Massive-bedded, slightly magnesian, gray and dove colored 

limestones with numerous small, narrow-chambered cephalopods near the summit ................................... 35

(6) Massive layers of steel-gray, more or less arenaceous limestone .................................................... 125

(7) Bird's-eye limestone....................................... G

(8) Black Eiver limestone..................................... 4

(9) Trenton limestone............... .......................... 40

The limestone (2,3) capping the sandstone (1) of the section is also found at 

Whitehall and at Comstock's Landing, Washington County, New York, where it has 

been, as was the limestone (2,3), referred to the Calciferous. The limestone 2 aud 3 

appears to have been, on the southwestern side of the Adirondack Mountains, the 

closing deposit of the Cambrian; and there is but little doubt that if we could find 

a fauna in the limestone (4) of the section it would serve to connect the Cambrian 

aud Lower Silurian (Ordovician) faunas. 1

The following fauna was found in No. 3 of the section:

Cryptozoa proliferum. Billingsia saratogensis.

Lingulepis acumiuata. Matthevia variabilis.

Platyceras mmutissiuium. Dikelocephalus hartti.

hoyti. speciosus.

Metoptoma cornutiforme. Ptychoparia calcifera.

simplex. (A.) saratogensis.

The comparison of the Chateaugay Chasm section with that of Saratoga County proves very clearly by the included faunas that the Potsdam epoch closed on the south side of the Adirondacks with a deposit 

of limestone carrying the Dikelocephalus fauna. It is found in the 

upper beds of the quartzite on Marble River in the township of Chateaugay, and in each section the Calciferous formation is superjacent to 

the closing epoch of the Potsdam.

The greatest depth reached in the formation is that of the section of 

Hemmingford Mountain. Unfortunately this section has not been 

studied so as to determine whether there is any fauna present in the 

sandstones. The section at An Sable Chasm, however, shows that a second horizon of the Upper Cambrian fauna occurs about the Adirondacks. This is the zone of PtycJioparia minuta, corresponding to the 

zone of Ptychoparia minor of the Wisconsin section.

1 Second contribution to the studies of the Cambrian faunas of North America. U. S. Geol. Survey 

Bull. No. 30, 1886, p. 22.
WALCOTT.] SUMMARY SOUTH DAKOTA. 347

The presence of the Potsdam terrane on the south side of the Adirondacks, along the valley of the Mohawk, has not been positively 

proved. At Little Falls a thin layer of sandstone, resting unconformably upon the pre-Paleozoic rocks and beneath the Calciferous sandrock, 

has been referred to the Potsdam. The discovery by Profs. Shaler and 

Williams of a thin layer of shale, resting upon this layer of sandstone, 

on the north side of the river at Little Falls, in which specimens of 

Lingulepis acuminata occur, lends more authority for the statement that 

the Potsdam is present; but as the species Lingulepis acuminata ranges 

up into the Calciferous sandrock, both at Whitehall, New York, and 

on the north side of the Adirondack Mountains in St. Lawrence County, 

it is doubtful if we can claim the presence of the Potsdam at any point 

in the Mohawk Valley. There is not, however, any definite reason why 

a thin bed of it, with the typical Potsdam fauna, should not be found 

beneath the Calciferous, if it is not concealed by the overlap of the 

superjacent Calciferous and Trenton terranes.

The sediments of the Adirondack sub-Province and its Canadian extension, with a single exception, were accumulated in a shallow sea not 

far removed from the shore-line. Eipple-marked sandstones and trails 

of marine invertebrates occur. The sandstone is relatively tine-grained 

with the exception of a small deposit of conglomerate in St. Lawrence 

County, New York. The formation belongs to the Upper Cambrian, 

and overlaps upon the sloping shores of the pre-Cambrian land. The 

one exception to the arenaceous deposit are the limestones in Saratoga 

County, New York, which were deposited On sandstone and overlap on 

to the pre-Cambrian rocks. The fauna of the limestone is the same as 

that of the quartzite at Marble Eiver, near Chateaugay Chasm, on the 

northern side of the Adirondacks.

WESTERN BORDER OR ROCKY MOUNTAIN SUB-PROV1NCE.

This includes the Cambrian rocks of South Dakota, southern central 

Montana, central and northwestern Wyoming, and Colorado.

SOUTH DAKOTA.

The chief summary of our knowledge of the Cambrian rocks of the 

Black Hills of Dakota is taken from the reports of Messrs. Newton and 

Carpenter. The sandstone identified as the " Potsdam " is the lowest 

member of the fossiliferous series, and in numerous and excellent exposures its character and relations are easily determined and studied. 

It everywhere rests unconforrnably upon the upturned edges of the underlying Algonkian slates and schists, filling up irregularities in their 

surfaces, and its basal member is generally formed of coarse materials 

derived from the erosion of the subjacent rocks. Consisting mainly of 

coarse and friable sandstones, with conglomerates easily eroded, it 

covers superficially very limited areas.

By a reference to the geological map accompanying the report of Mr. 

Henry Newton the exposures of the " Potsdam " sandstone will be seen
348 THE CAMBRIAN. [BULL.81.

to form a very narrow band surrounding the "Archean" area. Though 

essentially a sandstone formation it has some variety of composition. 

Usually it carries a conglomerate at the base, but this is sometimes exchanged for a dense quartzite, and in many places there are interstratified beds of quartzite. In a few localities the formation is quite calcareous and in a great number it contains peculiar greensand deposits. 

Its thickness is quite uniform, ranging generally from 200 to 250 feet, 

but attaining to 300 feet on the north branch of Eedwater Creek. Complete sections from the "Archean " to the Carboniferous are rarely met 

with, but one measured in the eastern canon of Spring Creek by Mr. 

Jeniiey is as follows: l

Arcliean.

Feet.

(1) Argillaceous slates, dipping 60° west ......................................

Potsdam.

(2) Brownish yellow conglomerate, with quartz pebbles, resting unconformably

on 1 and dipping 25° northeast.......................................... 25

(3) Reddish brown sandstone, thinly bedded at base and alternating with soft, 

shaly sandstones, containing large fucoids, Lingulepis, and fragments of 

trilobites ............................................................... 200

Carboniferous.

(4) Reddish brown, or pinkish calcareous sandstone, thinly bedded, containing

Spirifera camerata, cyathophylloid corals, and criuoid columns............ 20

(5) Limestone: Spirifera camerata, Productus, etc.............................. 335

Many details are given of the local phenomena presented by the sedimentation and mode of occurrence of this formation; extended comparisons are made between it and the correlated sandstones about the 

Big Horn and Wind Eiver Mountains ofr Wyoming, the sandstones of 

the Mississippi Valley, and the typical Potsdam sandstone about the 

Adirondacks of New York.

The following is a list of the fossils found in the sandstone and 

identified or described by Prof. E. P. Whitfield: 2

Palajochorda prirna. Lingulepis dakotensis.

Palseophycus occidentalis. O bolus 1 pectenoides.

Palseophycus. Obolella polita.

Scolithus. nana.

Lingulepis pinnaformis. Crepicephalus centralis.

cuneolus. planus.

perattenuatus.

Prof. F. E. Carpenter describes the " Potsdam" in the Black Hills as 

follows:

The present site of the uplift existed as a slowly sinking island in the Potsdam 

ocean, probably the last surviving land of a vast area eroded and submerged by

1 New ton, Henry: Geology.- Report on the Black Hills of Dakota. U. S. Geog. and GeoL Survey 

of the Rocky Mountain region, J. W. Powell In charge, 1880, p. 88. 

>Op.cit.,p.l07.
WALCOTT.1 SUMMAKY WYOMING. 349

the advancing waters. The base of the Potsdam entirely around its outcrop is 

a conglomerate. The ocean advanced upon the laud with an action that has been 

aptly termed that of a horizontal saw. The cliffs were undermined by its action, 

the debris thus formed worn to bowlders, to gravel, and to sand. As the shore-line 

advanced and a given point became farther from land, it received finer and finer sediments, until sedimentation, in this area at least, entirely ceased. 1

He calls attention to the fact that the sandstone thins out towards 

the central portion of the Black Hills uplift. Near Harney Peak the 

last outliers are about 50 feet thick between the nn conform able subjacent "Archean" rocks and the undisturbed conformable superjacent 

Carboniferous limestone.

WYOMING.

There has been comparatively little detailed information published 

relating to the Cambrian rocks of the Big Horn Mountains. Dr. F. V. 

Hayden visited the range in 1861 and found the nucleus composed of 

red feldspathic granite and a series of stratified .Azoic rocks. Besting 

on these occur the sandstones which are referred to the " Potsdam." 

He found a few thin layers of fine calcareous sandstone filled with fossils characteristic of the period.2 These were studied by F. B. Meek, 

who identified Oonocoryphe and perhaps Dikelocephalus.3

According to Prof. T. B. Comstock, the sandstone referred to the 

Potsdam attains a thickness of about 200 feet in the region of the Wind 

Eiver Mountains, and above the sandstone on the eastern side, along 

>the central portion of the range is a series of limestones resting on the 

sandstone, having a thickness of about 200 feet. From specimens colilected in the limestone he identified a trilobite of the genus Dikelocephalus, several specimens of what was supposed to be Orthis tritonia, 

and a quantity of a species of Theca.4 As far as Prof. Comstock's observations extended the sandstone rested unconformably upon the subjacent metamorphic rocks.5 On the map accompanying the report the 

" Potsdam " formation is represented as occurring all along the eastern 

side of the Wind Eiver range, and also along the central portion of the 

western side. The latter occurrence, however, is denied by Dr. A. 0. 

Peale.6 Dr. Hayden noted in 1862 the presence of a sandstone resting 

upon the vertical edges of the Azoic clay slate series in the Laramie 

Mountains, which he referred to the age of the Potsdam sandstone,

'Notes on tbe geology of the Black Hills. Preliminary Bep. Dakota School Mines, on the Black 

Hills of Dakota, 1888, p. 31.

2 Hayden, 3?. V.: Sketch of the geology of the country about the headwaters of the Missouri and 

Yellowstone Rivers. Am. Jour. Sci., 2d ser., vol. 31, 1861, p. 234.

8 Meek, F. B.: Preliminary paleontological report with remarks on the ages of the rocks, etc. U. 

S. Geol. Surv. of the Terr.. Sixth A.nn. Kep., 1873, p. 465.

4 Geological Report. Report upon the reconnoissance of northwestern Wyoming, made in the summer of 1873, by William A. Jones. 1874, pp. 108-110.

8 Op. cit., p. 106.

"Report on the geology of the Green River district. TJ. S.Geol. Surv.of the Terr., llth Ann. Bep., 

1870, p. 524.
350 THE CAMBRIAN. IBULL.SI.

although no organic remains were found. In the vicinity of the headwaters of the Niobrara River he measured a section as follows:

Feet.

(1) Quartzose sandstone, some parts filled with pebbles........................ 22

(2) Bed argillaceous slate..................................................... 5

(3) Sandstone, dull .reddish ferruginous, like bed 1, above...................... 37

(4) A series of strata more or less inclined, composed of gneiss with silvery mica 

in large plates, micaceous and talcose slates, white quartz, etc.

He states further that he has no doubt the Potsdam sandstone 

occurs in the form of an outcropping belt all along the Laramie range 

of mountains, although he was unable to discover any organic remains. 

He correlated it with the Potsdam on the evidence afforded by the 

Black Hills section of Dakota. The occurrence of the sandstone at 

this horizon is noted by him at numerous localities on the flanks of the 

Laramie Mountains,1 In opposition to the view of Dr. Hayden may 

be cited that of Mr. Arnold Hague, who states that all paleontological 

evidence obtained from the beds associated with the quartzite and 

above them tend to show that they belong to the Coal-Measure limestone.2

In 1871 Dr. Hayden found Obolella and a Lingula in a considerable 

thickness of Potsdam sandstone on the south side of the Sweet water 

River, near the southeastern termination of the Wind River Mountains, 

thus establishing by paleontologic evidence the Upper Cambrian or 

Potsdam age of the sandstone referred to that horizon in 1861.3

A small area of paleozoic roeks on the northwestern end of the Wind 

River range has, according to Prof. Orestes St. John, a sandstone at 

the base that rests on the Archean. It is coarse grained, grayish, buff, 

reddish stained, thin bedded, with oblique laminated layers and locally 

quartzitic. The greatest exposed thickness of this bed probably does 

not exceed 50 feet. Its exact relation to the underlying Archean rocks 

and to the superjacent strata referred to the Quebec was not determined.4 On the diagrammatic section accompanying the report formation No. 2, or the Potsdam, is represented as resting unconformably 

upon the Archean and conformably subjacent to limestones referred to 

the Quebec.

The Cambrian strata of northwestern Wyoming are contained within 

the district of the Teton range, Gros Ventre range, and the Buffalo 

Fork Mountains, all of which are reported upon by Prof. St. John. He 

quotes Prof. Bradley in relation to the lower quartzite, stating it to be a 

very compact ferruginous quartzite, with a thickness of from 50 to 75 

feet. Above this occurs about 300 feet of sandstone strata on the

1 Hayden, F. V.: The Primordial Sandstone of the Eocky Mountains in the Northwestern Territories 

of the United States. Am. Jour. Soi., 2d series, vol. 33,1862, pp. 70, 71.

'Descriptive Geology. TJ. S. Geol. Expl. of the Fortieth Par.; vol. 2. Washington, 1877, p. 76.

3 Report of P. V. Hayden (on the geological survey of Wyoming). U. S. Geol. Surv. of the Terr., 

4th Ann. Hep., 1871, p. 33.

"Eeport on the geology of the Wind Eiver district. F. S. Geol. Surv. of the Terr., 12th Ann. Eep., 

1883, p. 253.
WALCOTT.] SUMMARY COLORADO. 351

higher slopes of the mountains, according to Prof. Bradley, in theTetou 

range. The same series of deposits evidently occurs in the Gros Ventre 

range, and in the Buffalo Fork Peak uplift. In the Gros Veutre range 

the quartzites were seen in immediate contact with the uuconforrnable 

Archean schists.1

The superjacent limestone, called the " Lower Quebec limestone" by 

Prof. St. John, occurs in the Teton range and the Gros Veutre. But 

it is in Buffalo Fork Peak that the best section was obtained. Hero 

there is an exposed thickness of from 50 to 75 feet of bluish and dark 

drab, brecciated, thin bedded, rough weathering limestone, above which 

occurs what he calls the passage beds to the " Upper Quebec limestone." 

These beds are yellowish, arenaceous, micaceous clay, with indurated 

layers charged with a small orbiculoid shell and thin layers of dirty drab 

limestone, the weathered surfaces of which are crowded with the fragmentary remains of trilobites and other fossils. Among others there have 

been identified the genera Conocoryphe and Dikelocephalus. The 

upper portion of the deposit is here composed of bluish drab shales and 

brownish gray shaly sandstones. It reaches a probable thickness between 100 and 200 feet.

The superjacent limestone called the " Upper Quebec limestone " 

shows almost the same development in the Teton and Gros Ventre 

ranges and the Mount Putnarn area of Idaho. The rock consists of 

generally thin bedded, fragmentary, sometimes brecciated limestones, 

color gray, grayish buff, and pinkish, carrying small sized trilobites and 

a gasteropod resembling Eaphistoma. In the Teton range the series 

of rocks has a thickness of 100 feet or more, and forms mural exposures 

oh the caiion walls.

A review of the reports of Messrs. Bradley and St. John shows that 

the Upper Cambrian horizon is to be recognized in the Teton, Gros 

Ventre, and Buffalo Peak Mountains, and that it is composed of a basal 

zone of varying thickness, upon which rests a limestone carrying Upper Cambrian fossils. This limestone is the equivalent of the " Lower 

Quebec " of Prof. St. John's section. His " Upper Quebec " is to be 

referred to the base of the Lower Silurian (Ordoviciau) or corresponding to the Calciferous zone of the New York section.

COLORADO.

The identification of rocks of Cambrian age in Colorado has been 

made, with one exception, upon stratigraphic and lithologic evidence. 

The exceptional instance is that mentioned by Mr. S. F. Emrnous, who 

found a distinctly Upper Cambrian genus, Dikelocephalus, in a bed of 

greenish chloritic shale that he assumed to occur above the main body 

of the quartzite and near the base of the transition series that passes

1 Eeport of the geological field work of the Teton division. TJ. S. Geol. Sur. of the Terr., llth Ann. 

Kep., 1879, p. 481.
 352 THE CAMBRIAN. [BULL. 81.

into the Silurian limestone.1 He describes the strata in the Mosquito 

range referred provisionally to the Cambrian as follows:

The beds assigned provisorily to this horizon * * * are prevailingly of 

quartzite. To them, therefore, the local name of Lower Quartzite has been given. 

There average thickness is about 150 feet to 200 feet, of which the lower 100 feet are 

composed of finely and rather thinly bedded white saccharoidalquartzites, while the 

upper 50 feet are shaly in character and more or less argillaceous and calcareous, 

passing by almost imperceptible transition into the siliceous limestone of the Silurian 

formation above.

At the very base of the series, at the contact with the underlying Archean, wherever 

this could be observed, is found a persistent bed of fine grained conglomerate, from 

a few inches to a foot in thickness, made up of rounded and finely polished grains of 

bluish translucent quartz, generally not larger than a pea in size. Above this is a 

white qnartzite of remarkably uniform and persistent character, always very readily 

distinguishable as a white band in the numerous sections offered by the canon walls 

of the range. Its thickness, when measured on the west side of the range or near the 

Sawatch Island, is, as mentioned above, 100 feet of purely siliceous beds. On the east 

side of the range the thickness seems somewhat to diminish, and in places was found 

to be only 40 feet. * * *

Owing to their similar lithological character and to the general absence of fossil 

evidence it is difficult to establish a hard and fast line between this and the succeeding formation above. In practice the line has been drawn at the top of the shaly 

beds, and the commencement of the beds of more massive limestone. The transition 

beds consist essentially of alternating bands of calcareous quartzite and shales. The 

name sandy limestones is often applied to them for the reason that on weathered 

surfaces of the cliff faces they appear like sandstones, the carbonate of lime having 

been entirely washed out, and only the fine quartz grains left on the thin surface 

crust.4

As already stated, the only fossil remains found in this series occur 

in a bed of greenish chloritic shales on the east flank of Quandary Peak, 

about a mile above the Monte Cristo mine. They belong to the genus 

Dikelocephalus, and closely resemble- DiJcelocepJialus minnesolensis of 

the Potsdam formation of Wisconsin. This band of shales was not 

found in stratigraphic relation to the quartzite of the limestone of the 

sections already mentioned, but it occurs above a heavy white quartzite and beneath a bed of white marbleized limestone; and, from analogy with other sections, Mr. Bmmons thinks it safe to assume that it 

occurs above the main body of quartzite and near the base of the transition series.3

For the purpose of comparison, a section was measured by Mr. Whitman Cross, in William's Canon, near Manitou Springs. Of this section 

Mr. Emmons says:

The purely siliceous beds at the base are much thinner than in the Mosquito Range, 

the greatest thickness found being 50 feet. They are succeeded by calcareous sandstones and shales of variegated colors, red prevailing, which pass up into white or 

drab limestones, sometimes containing chert secretions and alternating with shaly 

beds, with an aggregate thickness of about 200 feet. These beds may be considered as 

the equivalents of the lower quartzite and white limestone of the Mosquito Kange. 4

1 Geology and mining industry of Leadville, Colorado, TJ. S. Geol. Surv., Monograph, vol. 12,1886, 

p. 60. 

»0p.cit.,pp.68,59. »0p.cit.,p,60. « Op. cit., p. 62.
WALCOTT.] SUMMARY COLORADO. 353

From the east bank of Trout Creek, in Manitou Park, Mr. Cross obtained fossils from a reddish brown sandstone, 45 feet above the 

Archean, among which an elongate form of Lingulepis, allied to L. pinnaformis of the Potsdam sandstone of Wisconsin, occurs. From the 

red calcareous sandstones, alternating with white limestone, 105 to 122 

feet above the Archean, the fauua is the type of that of the lower portion of the Lower Silurian (Ordovician).

Two sections measured on Trout Creek by Dr. A. C. Peale gave the 

following results :l

No. 4.

Feet.

?5 w

16

4

i -

No. 5.

Feet.

65

13

3

60

" Beds No. 6 and 7 are fossiliferous and belong in all probability to 

the Quebec group, while the sandstones below are Potsdam." A list 

of fossils is given as coming from No. 7 which indicates a grouping of 

Cambrian and Silurian (Ordovician) genera unknown elsewhere.

Dr. F. M. Endlich's synopsis of the rocks of the Potsdam group found 

in Colorado sums up all that was known to him of the principal localities and the character and thickness of the strata. Seven localities 

are mentioned, as follows :z

Feet.

^ f Lime Creek .... ........

P Eagle River............

2 | Four-mile Creek .......

Pi TroutCreek. ...........

2 I North of MountOuray... 

-S Near Cauyou City ......

pjj [(*len Eyrie.

White sandstone and quartzite.............

White q uartzites..........................

Red and pink sandstones and quartzites....

Yellow and pink sandstones................

White and pink quartzites.................

Variegated micaceous and calcareous sandstones. 

Red sandstones and quartzites .............

250

300 to 400 

160

80

200

40

Average thickness of strata . 180-

That the Upper Cambrian zone is represented is fairly well proved 

by the Mosquito Eange section and that of Trout Creek of the Colorado 

Range, and it is very probable that the sandstones correlated with the

< Report of A. C. Peale, M. D., Geologist of the South Park Division. TJ. S. Geol. Surv. of the Terr., 

7tli Ann. Rep., 1874, p. 208.

3 Report of F. M. Eudlich, Geologist of the White River Division. TJ. S. Geol. Surv. of the Terr., 10th 

Ann. Rop., 1878, p. 130.

Bull. 81 23
354 . THE CAMBRIAN. [BULL. 81.

Potsdam really belong within the Upper Cambrian horizon. From our 

present knowledge the Upper Cambrian zone is the only portion of the 

group represented in Colorado.

The Cambrian rocks included within the States of Colorado, Wyoming, Montana, and South Dakota are of the type of those of the southern Interior Continental, Upper Cambrian series, and consist usually of 

a bed of quartzite or conglomerate, resting unconformably upon the 

Algonkian or Archean, and passing above into calcareous beds that 

frequently carry the Upper Cambrian or Potsdam fauna. This is the 

case with the formation about the Big Horn Mountains, Wind Eiver 

Mountains, and the Teton and Gros Veiitre ranges of Wyoming. In 

some instances, however, as about the Black Hills, a fauna occurs in the 

basal sandstone similar in character to that of the St. Croix sandstone 

of the upper Mississippi Valley. Traces of a fauna were found in Colorado, at Quandary Peak, in a schistose rock that is supposed to occur 

just above the quartzite.

SOUTHWESTERN" SUB-PKOVINCE.

The widely separated areas of Cambrian rocks in Central Texas and 

northwestern Arizona are united in one sub-province on account of their 

similarity in stratigraphic position, general sedimentation, and faunas.

TEXAS.

With the exception of the doubtful occurrence of the Upper Cambrian 

zone as a sandstone in the Organ Mountains of southwestern Texas, as 

mentioned by Mr. W. P. Jenney, the Cambrian formation is, as far as 

known, confined to the Paleozoic uplift in the central part of the State 

that includes Llano County within its central portion.

A section of the formation measured by Dr. B. ~F. Shumard in Burnet County, 5 miles northwest of the town of Burnet, is as follows: J

Feet. 

No. 1. Soft, chalky limestone with well marked cretaceous fossils.... _....... 50

No. 2. Gray and bluish gray hard limestone, of a sandy texture, in beds from a 

few inches to a foot thick, and containing Arionellus (Batliyurus?) 

planus, Batliyurus depressus, Camerella sp., Orthis color adoensis, Orthis 

sp.?, Disoina microscopica, and Lingula sp.?..-......................... 81

No. 3. Mottled gray, purple, and greenish, earthy and subcrystalline limestone, 

with alternating bands of siliceous limestone contains the same fossils 

as No. 2.............................................................. 45

No. 4. Slope with projecting ledges of No.3................................... 55

No. 5. Slope.................................................................. 24

No. 6. Schistose coarse texfcured limestone, made up of crystalline particles and

abounding with fragments of trilobitesj chiefly Arionellus ............ 20

Total........................................................ 275

1 The Primordial zone of Texas, with, descriptions of new fossils. Am. Jour. Sci., 2d ser., vol. 32 1801, 

p. 216.
WALCOTT.] SUMMARY TEXAS. 355

A second sectioD, takeu about 1 mile south of the preceding, is also 

quoted, as it carries the series down to the granite: 1

Poet. 

No. 1. Cretaceous strata in horizontal beds.................................... 110

No. 2. Slope, covered with conglomerate, composed of pebbles of sandstone and

calciferous saiidrock, rather firmly cemented----------- .............. 12

No. 3. Potsdam sandstone, consisting of thin layers of variegated green, gray, 

and purplish sandy limestone, with bauds of dolomite and silico-calcareous rock iuterstratified. Some of the beds are highly charged with 

trilobites, of which the most common are Arionellua texanua, Dikeloce-- 

phalus roemeri, and Conoce2)halites lillingsi ....................... t. ... 40

No.'4. Highly ferruginous siliceous sandstone, composed of fine grains, loosely 

cemented, passing downwards into coarse gritstone and conglomerate. 

The upper beds contain Lingula and Obolus (?)-...................... 60

No. 5. Flesh colored granite, interstratified with veins of milky quartz........ 6

From the sections it will be observed that the strata consist largely 

of limestone, with a bed of sandstone at the base.

The section of Packsaddle Mountain, in Llano County, in the valley 

of Honey Creek, is given as follows by Mr. C. D. Waicott in 1884:2

Feet. 

5 = Potsdam limestone........................................ 60

4 = Potsdam sandstone........................................ 30

3 = Potsdam limestone........................................ 310

2 = Massive Potsdam sandstone ............................... 205

1 = Llano group.

605

The fauna collected included 12 genera and 25 species, all characteristic of the Upper Cambrian zone.

A comparison of the Texas section with that of the Grand Canon of 

the Colorado, in northern Arizona, leads to the conclusion that they 

belong to the same area of sedimentation. In each a massive sandstone at the base is subjacent to alternating sandstones and limestones 

that carry essentially the same fauna. The sections of the lower sandstones of the eastern slopes of the Rocky Mountains partake somewhat 

of this character, especially those of the Big Horn range in Wyoming. 

In Wisconsin, etc., the calcareous beds of the Texas section are absent, 

but the presence of the Dikelocephalus fauna at the summit of each 

series above a zone carrying what may be called the Ptychopariaminor 

fauna, proves that the life of the two areas continued on in the same 

succession despite the change in sedimentation and environment.

In a report on the Cambrian system Prof. T. B. Comstook concludes 

that at least two and probably three series of Cambrian strata are 

represented in central Texas.3 To the basal beds he gives the name 

Hickory series (Lower Cambrian ?). For the second horizon the name 

Eiley series (Middle Cambrian ?), and for the upper series the name

1 Op. cit., p. 217.

'* Note on Paleozoic rocks of central Texas. Am. Jour. Sci., 3d ser., vol. 28,1884, p. 432. 

3 A preliminary report ou the geology of the central mineral region of Texas. 1st Ann. Kep. Geol. 

Surv. of Texas for 188!)-'90, pp. 285-201.
356 THE CAMBKTAN. [BULL. 81.

Katemcy (Potsdam) series (Upper Cambrian *?). This upper series is 

divided into Division A, the Potsdam sandstone j Division B, the Potsdam flags; Division C, the Potsdam limestone.

ARIZONA.

As far as known the Cambrian rocks of Arizona are confined to the 

sections exposed by the Grand Canon of the Colorado and along the 

southwestern margin of the great Colorado Canon plateau.

A seqtion measured near the head of the Grand Canon has 300 feet 

of sandstone at the base that rests unconformably upon the subjacent 

Algonkian (Chuar) formation. Above the sandstone there are 700 feet 

of alternating sandstones, shales, and limestones throughout which fossils of the Upper Cambrian zone have been found. These include the 

genera Cruziana, Lingulepis, Iphidea, and Ptychoparia. At the summit 

of the lower sandstone a small group of fossils was found -which includes 

the genera Olenoides, Ptychoparia, Lingulepis, and Leperditia. The 

upper part shows close relation to that of the Potsdam sandstone horizon of central Nevada, the Mississippi Valley, and New York, while 

that of the lower zone or the summit of the sandstone is more nearly 

related to that of the Middle Cambrian zone of the Southern Appalachians. There is a large quantity of material in the laboratory of the 

0". S. Geological Survey yet remaining to be studied, but I think these 

conclusions will not be materially changed.

At the mouth of Kanab Creek, west of the Kaibab Plateau, there are 

100 feet of arenaceous and micaceous shales, subjacent to a massive 

stratum of mottled limestone. In the lower 450 feet of the latter and 

in the arenaceous shale fossils were found similar in character to those 

of the upper portion of the section, as seen near the head of the canon. 

They include Lingulepis, Hyolithes, arid Ptychoparia.

The section at the mouth of the Grand Canon, as given by Mr. A. 

E. Marvine, is as follows:]

Feet. 

Red wall limestones.

Tonto marble limestones.

(Green...................... j f,

Tonto shales ................. <j Snuff.colored ................\ 90

. [Green ........................ 415

Tonto sandstone ....... .................................... 80

Granite....................................................... 90

Mr. Marvine says that in going southward from the mouth of the 

canon the Tonto shales seem to diminish in thickness, and at Tinnakah 

Springs they are estimated at less than 400 feet. A few miles south 

of this point they were still thinner, being estimated at less than 100 

feet. The Tonto sandstone, however, has increased much in thickness 

and forms the greater portion of the section.

1 Eeport on the geology of route from St. George, Utah, to Gila River, Arizona, examined in 1871. 

Kep. on Geog. and Geol. Expl. and Surv. west of 100th merid., in charge of Lieut. Geo. M. Wheeler, 

vol. 3, Geology, 18V 5, p. 199.
WALCOTT.J SUMMARY TEXAS. 357

On the atlas sheet issued by the Wheeler Survey in 1874 the Silurian 

(which also included the Tonto formation) is represented as extending 

from the head of the Grand Canon along the entire course of the cafion 

to its mouth, and thence southward along the western margin of the 

Colorado plateau to Music Mountain, where the outcrop broadens out 

and extends southwest along the southwestern margin of the plateau. The most 

southeastern outcrop is on the'Rio Verde 

Eiver near the lower end of Williamtown 

Valley.

In all the sections on the line of the 

Grand Canon and the western and southwestern margins of the Colorado Plateau 

the Tonto sandstone rests uncomformably 

upon either Algonkian or Archean rocks. 

In its greatest development the formation 

attains a thickness of 1,000 feet and represents the Upper Cambrian zone, and 

possibly in the lower portion, the Middle 

Cambrian.

\lajdk ffiJJLs S.DaJtota«

Central. Wisconsin*.

The sediments of this province are those 

deposited as the sea advanced slowly upon 

the laud and distributed the d6bris worn 

from it or brought in by tributary streams 

as layers of sand along the coast line and 

in an adjoining shallow sea. From Arizona to Texas, to Missouri, the Black 

II i Us, and the eastern margin of the Eocky 

Mountains, and all along the northern line 

in Minnesota, Wisconsin, Michigan, Canada, and the Adirondacks of New York 

the record is the same sandstones resting 

upon pre-Cambrian rocks and carrying 

essentially the same fauna. In some regions the depth of water increased more 

rapidly and calcareous deposits accumulated upon the sand, as in Arizona, Texas, 

the Black Hills, and in some localities 

along the eastern base of the Eocky ' n 

Mountains. That the sea was shallow, wide spread, and advancing 

along a great extent of coast line is shown by the sediments and the 

presence of a similar fauna in New York, the Upper Mississippi Valley, 

the Black Hills, the eastern front of the Eocky Mountains, and far to 

the south in Texas and Arizona. All over this broad area the relainch). Thenuth feeto,«.» 

and Fls. n. >n i 

L| 1

i

i&i 

o

iH«l!*

Eastern. WtsCon&tru.

AOreartdddt. 1W
358 THE CAMBRIAN. [BULL.61.

tive stratigraphic succession of the sub-divisions of the Upper Cambrian fauna is the same; and nowhere do we know of the existence of 

formations characterized by the Lower and Middle Cambrian faunas 

of tbe Atlantic coast, Appalachian and Eocky Mountain provinces, 

except, perhaps, the Middle Cambrian fauna in the southwestern Interior 

Continental sub-Province.

In the Atlantic Coast Province the basal beds of the Olenellus zone 

rest unconformably upon Archean and Algoukian rocks. The sea deposited the Cambrian sediments across the upturned edges of the Laurentiau and those of the superjacent 

bedded sandstones, quartzites, argillitos, and slates forming the Algon- 

,_,_ IJJlue- -s, kian series, which Dr. Murray referred 

j"° to the Huronian. The upper St. M.c.r

____ 27 2a 2, John's slates carrying the Aspidella

FIG. 5. Sections of the Interior Continental Were alSO planed away by the CamProvince, in the south central and south- brj an gea. jn the Interior Continental

western portions. . . _.. .

Province in Wisconsin and Minnesota

the Upper Cambrian sandstones are unconformably superjacent to the 

corresponding series of rocks, or the Laurentian, Huronian, and 

Keweenawan series of the Lake Superior region. In the first instance 

the earlier Cambrian sea transgressed upon the pre-Cambrian rocks, and 

in the latter case the later or closing epoch of the Cambrian was the 

one in which the deposits were accumulated upon the Archean and 

Algonkian rocks. A misapprehension of .these facts has lad several 

geologists to refer the Keweenawau and other pre-Cambrian rocks to 

the Cambrian.

DESCRIPTION Or PLATE I.

Geographic distribution of the Cambrian strata shown ~by surface outcrops in North

America.

The geologic provinces are indicated by the dotted lines. The Interior Continental 

Province is broken up into sub-provinces and these are united by a lighter dotted 

line. The provinces are :

A. Atlantic or Eastern Border Province. 

a. Eastern or Nova Scotia Basin. 

b. Southeastern Newfoundland, eastern New Brunswick, and Massachusetts Basin. 

c. Interior deposits of Gasp6, Quebec, Maine, New Hampshire, Vermont,

and Massachusetts.

B. Appalachian or Interior Eastern Border Province. 

C. Rocky Mountain or Western Border Province. 

D. Interior Continental Province.

D1 . Central Interior or Upper Mississippi and Missouri. 

D2 . Eastern Interior or Adirondack of New York, and Canada. 

D3. Western Interior or Dakota, Wyoming, etc. 

D4 . Southwestern Interior or Arizona and Texas.

The outlines of the provinces are drawn so as to include the outcrops known at 

present. They are arbitrarily assumed, as we do not know the exact limits of the 

original Cambrian sedimentation.
LT.S.GEOLOGICAL SURVEY. B ULLETIN NO 81 PI..1

DISTRIBUTION BY GEOLOGICAL PROVINCES

O F THE

CAMBRIAN STRATA AS SHOWN BY SURFACE OUTCROPS

IN

^TORTH AMERICA

BY

C.D.mLCorr

SCALE

A. Atlantic Coast Province. 

B . Appalachian " 

C . Rocky Mountain "

. Interior Continental Provinces 

D'. Central Interior. 

D 2 Eastern " 

D 3 Western " 

D 4 Southwestern Interior. E x! i

F o ft M E X J C

IITH. A. HO EN » CO., BALTIMOPL
WALCOTT.] SYNOPSIS. * 359

Owing to the uncertainty as to the Cambrian age of the outcrops of Nova Scotia, 

Maine, New Hampshire, and north into Canada, the indicated areas upon the map 

have horizontal black lines to distinguish them from the known Cambrian rocks.

SYNOPSIS OP THE CAMBRIAN GROUP.

The coordination of the Cambrian group in America, with the primary subdivisions of the Paleozoic Silurian, Devonian, and Carboniferous is largely a development of the past decade. Although strongly 

'advocated by Dr. T. S. Hunt and used by Sir J. W. Dawson in 1872, 

and the Fortieth Parallel^Survey in 1878, Le Conte's Elements of Geology of 1878 mentions, but does not use the name in classification, and 

Dana's Manual of 1876 classes the " Primordial or Cambrian " as the 

lowest formation of the.Silurian.

To-day the group is firmly established by (a) the presence in the 

Kocky Mountain province of 6,000 feet of limestone with 10,000 feet or 

more of quartzite beneath; (&) in the Appalachian Province by over 

12,000 feet of quartzite, shales, slates, and limestones; (c) a continental 

distribution; (d) a characteristic, highly differentiated fauna.

The various formations referred to the group are mentioned in the 

following table. In some instances it is not practicable clearly to define by name the exact limitations of the formation through which a 

certain division of the fauna ranges. In such cases reference will have 

to be made to the text for further description.
360 THE CAMBRIAN.

Classification of the formations.

IBULT* 81.

a

.1 "C §'

1 

o

 §

H3

S

Pi

£ 

d

 Sr-«

a

1

9

 3 s

S

q

1 .5

,0

S

cj

0

1

^

Lower Calciferous.

Potsdam. 

Acadian. 

f

Georgian. 

Lower portion of the Caloiferous sandrock of New York and Canada; Lower

Magnesian limestone of AViscousin, Missouri, etc.

Type.

Sandstones of the north and east sides of the Adirondacks Mountains of New

York and adjoining parts of Canada.

Correlated.

Limestones of the south side of the Adirondacks and Dutchess County, New

York, and an unknown portion of the limestones of the " Marble Belt " of

western Vermont.

Shales of Tennessee (Knos), Georgia, and Alabama (Connasanga).

Sandstones of the Upper Mississippi Valley (St. Croix), South Dakota, "Wyoming, Montana, and Colorado.

Sandstones and calcareous beds of northern Arizona (Tonto) and central Texas

(Katemcy).

Limestones and shales of Nevada (Hamburg), Idaho, and Montana (Gallatin).

Black shales of the upper portion of the New Brunswick and Cape Breton

Island sections.

Shales and sandstones of Conception Bay, Newfoundland (Belle Isle).

Type.

Shales and slates of eastern Massachusetts (Braintree), New Brunswick (St.

John), and eastern Newfoundland (Avalon).

Correlated.

Limestones of Dntchess County, New York (Stissing), and central portions of

Tennessee and Alabama sections (Coosa).

Limestones of central Nevada and British Columbia (Mount Stephen).

Type.

Shales and limestones of western Vermont (Georgia) and Red Sandrock.

Correlated.

Qnartzite of western slope of Green Mountains (" Granular Quartz ") and Appalachian Range of Pennsylvania, Virginia, Tennessee (Chilhowee), Georgia,

and Alabama.

Shales with interbedded limestones and rooting slates of southern Vermont,

New York, and south to Alabama.

Limestone, sandstone, and shalt& of Straits of Belle Isle (Labrador), northwest

coast of Newfoundland, and peninsula of Avalon (Placentia).

Basal series of Hanford Brook Section, Caton's Island, etc., New Brunswick

(Hanford).

Shales and limestones of eastern and southeastern Massachusetts (Attleborough).

Lower portion of Eureka and Highland Ranges, Nevada (Prospect).

Portion of Wasatch Cambrian section (Cottonwood).

Base of Castle Mountain limestone, British Columbia (Castle Mountain).
CO

CO 

Table showing the order of succession of the Cambrian faunas in 

Cambrian Group. 1

Upper Cambria 11.

Middlu Cambrian.

Lower Cambrian.

Newfoundland.

Olenus zone.

Paradoxides zones.

Olenellus zones.

Massachusetts.

Paradoxides 

Unknown.

zones.

Olenellus zones.

New York.

Dikelocephalas 

zones.

Indicated by other 

g.-u era than Paradoxides.

Olenellus zones.

Tennessee.

Represented 

Present.

b y 

other genera 

than Paradoxides.

Olenellus zones.

Nevada and Ut

Dikelocephal

zones.

Represented 

other gene

than Parado

ides.

Olenellus zones
362 THE CAMBEIAN. [BULL.81.

BASE OF CAMBRIAN.

The statements made in the preceding paragraphs foreshadow the 

conclusion that over the Interior Continental area the basal beds of the 

upper division of the group rest unconformably upon pre-Cambrian 

rocks. This is true also of the lower division of the Atlantic Coast 

Province, but in the Lake Champlain Valley and the Southern Appalachian Province there is no positive assurance that the conformable series of strata beneath the Olenellus zone do not pass down into some 

pre-Cambrian group. In Nevada, Utah, Montana, and British Columbia the same conditions exist to a more marked degree, and I have, in 

the absence of paleontologic proof, referred the conformable pre-Olenellus strata to an Algonkian group. That a considerable portion if not all 

of the series will be ultimately referred to the Cambrian is probable 

from the fact that the Olenellus fauna has been traced downward 

through 1,000 feet of limestone in the Champlain Yalley of Vermont and 

3,000 feet downward in the Bow Eiver series of British Columbia. The 

great vertical distribution of the fauna in the limestone leads to the expectation that it will be found to range through a considerable portion 

of the conformable strata beneath the narrow Olenellus zone of the 

Southern Appalachian and southern portion of the Rocky Mountain 

Province. On the map of sections the lower strata are provisionally 

and doubtfully referred to the Cambrian. This is in opposition to the 

view advanced in the Tenth Annual Eeport of the U. S. Geological 

Survey.

SUMMIT OF CAMBRIAN.

The determination of the top of the Cambrian is beset with more difficulties than its delimitation at the base. At the base there are marked 

unconformities, and in their absence the presence of a distinctly marked 

fauna beneath which no other fauna has yet been found. At the summit, however, we meet with a transition both in sedimentation and fauua 

to the characteristic type of the Silurian (Ordovician). One of the best 

illustrations of this is in the Eureka district of Central Nevada, where, 

in the Pogonip limestone, the passage from the Cambrian to the Silurian 

(Ordovician) is so gradual that it is only by the predominance of the 

fauna of one or the other of the two great groups that a line of demarkation can be drawn. The transition is such as might be expected where 

there was no marked physical disturbance to influence the change of 

faunas resulting from the natural dying out and development of species 

or the influx of new species from other areas. The sedimentation was 

very uniform, and no essential change of character occurs between the 

limestones of the Upper Cambrian and those of the Silurian (Ordovician). 

On the other hand, the delimitation between the two groups on the 

northern side of the Adirondacks is clearly and definitely marked by the 

occurrence of a light-colored, calciferous sandrock, with its distinctive 

fauna, resting upon a compact, hard quartzite, characterized by the
WAMOTT.] SYNOPSIS. 363

Dikelocepbalus fauna of the Upper Cambrian. Various grades of transition occur between these two extremes, but frequently it is necessary 

to draw an arbitrary line and define the upper limit of the Cambrian, as 

terminating where, in any continuous section, the Upper Cambrian fauna 

gives way, and is superseded by the types of the Siluriau (Ordovician) 

fauna. In Nevada this line would be drawnnear the base of the Pogonip 

limestone; in Tennessee, near the base of the Knox dolomite; in northern New York, north of the Adirondacks, between the Potsdam sandstone 

and the Calciferous sandrock; on the south side- of the Adirondacks, in 

the limestone between the Potsdam and Calciferous faunas; in the Upper Mississippi Valley, between the upper beds of the St. Croix sandstone and the Lower Magnesian limestone, or in some instances in the 

lower portion of the Lower Magnesian limestone; in the series of shales 

opposite Quebec, at Point Levis, beneath the graptolitic-bearing shales 

and the conglomerate carrying the Dikelocephalus fauna of the Upper 

Cambrian; and in western Newfoundland, in the limestones between 

the Upper Cambrian fauna and the base of the Ordoviciau fauna.

The paleontologic break between the Cambrian and Silurian groups 

is practically complete where the stratigraphic break is marked. About 

the Adirondacks the only species I know of that cross the break are 

the Lingidepis acuminnta and a species of Opliileta, at Chateaugay 

Chasm. In Wisconsin some of the species of the Upper Cambrian fauna 

apparently rise into the lower portion of the Lower Magnesian limestone, and are there associated with forms which are considered to be 

more typical of the Silurian (Ordovician) fauna. In Nevada, where the 

sedimentation is of the same character in the Upper Cambrian and the 

lower portion of the Silurian (Ordoviciau), there is a slight blending of 

the faunas, as shown by the occurrence of the genera Asaphus, Dikelocephalus, and Ptychoparia upon the same surface of rock. With our 

present knowledge, however, the occurrence of the same species in 

strata that are referred to the Cambrian and the Lower Silurian is so 

rare that they are the exceptions to the general rule.

It is not, however, by the specific break in the fauna that the two 

groups are separated; it is the general facies of the fauna referred to 

the Cambrian and that referred to the Silurian (Ordovician). The distinctness of the Upper Cambrian fauna from the Lower Silurian fauna 

100 feet beneath the line of contact of the two groups is such that I 

think there will be no confusion between the two faunas in America. 

In England the range of the genus Agnostus has complicated the separatencss of the two faunas, but this is not sufficient to combine them 

as a whole.

SEDIMENTATION OP THE CAMBRIAN GKOUP.

The physical and lithologic characters of the strata lead to the conclusion that the sediments were accumulated in relatively shallow seas 

in the immediate vicinity of the shores of land areas that were being 

slowly depressed in relation to the surrounding waters. There are
364 THE CAMBRIAN.

some exceptions, as, for instance, the deeper water limestone series of 

central Nevada, British. Columbia, and western Vermont, and perhaps the black shales of the Atlantic Coast Province. The assembled 

evidence sustains the view that at the beginning of Lower Cambrian 

time the area of the great Interior Province formed part of a continent, 

to the eastward and westward of which long ridges of pre-Cambrian 

rock separated interior seas and straits from the continental area and 

protected their contained life and sediments from the ravages of the 

open ocean. As the continent was slowly depressed and the waters 

advanced upon the land the sediments now forming the rocks of the 

Lower and Middle Cambrian series were accumulated in the various 

interior bodies of water to the eastward and westward of the main 

land area and between it and the outlying ridges. What the contour 

of the south and southeastern side of the continent was and to 

what extent the sea advanced upon it from the south during this 

time is unknown and may never be known, as only the formations 

that were deposited around the pre-Cainbrian islands of Texas and 

Missouri are now accessible for study. From the evidence afforded 

by these two localities and that along the eastern front of the Rocky 

Mountains, and the exposures of Cambrian strata in Wisconsin, Canada, etc., it is very probable that the main portion of the continent 

north of the thirtieth and south of the fiftieth meridian did not disappear beneath the advancing sea until near the beginning of Upper 

Cambrian time. The unconformable position of the Upper Cambrian 

rocks of the Interior Continental Province upon the subjacent Algonkian and Archean rocks sustains this conclusion.

As the sea was transgressing over the surface of the continent on 

its way northward across the broad interior in late Middle or early 

Upper Cambrian time it was also working along the base of the border 

ridges and depositing the sediments derived from them conformably 

upon those deposited, while the main mass of the continent was above 

the water. That these deposits were practically contemporaneous with 

those of the Interior Province is proved by the presence of the same 

types of animal life, and to a considerable extent of identical species.

Toward the close of Cambrian time a large portion of the continent 

had disappeared beneath the surface of the sea, and the great limestone-forming period of the Silurian (Ordovician) began. In some 

areas, as about the Adirondack Mountains of New York, argillaceous 

and arenaceous sediments were derived from the adjoining coast line, 

but as a whole mechanical sediments are absent.1

'In speaking of the conditions of sedimentation Messrs. Campbell and Rnffner state that "Changes 

such as these occurred, during a series of geological ages of unknown length, in a great inland sea 

which was once connected with what is now the Gulf of Mexico, on the south, limited probably by 

the highlands of Canada on the northeast, having the Archean ledges of the Blue Ridge for its 

southeastern border, and in all probability separated, in part at least, from the Pacific Ocean by the 

Rocky Mountain Range. This extensive sea. Avith Archean rocks for its bottom and shores, was the 

receptacle of the various materials that now constitute the surface rocks and soils of the Mississippi 

Valley." (A physical survey extending from Atlanta, Georgia, across Alabama and Mississippi to 

the Mississippi River, along the line of the Georgia Pacific Railway. Kew York, 1883, pp. 9,10.)
U.S.GEOLOGICAL SUKVEY. BULLETIN NO. 81 l'1-..II.

MAP

To Illustrate

the relative amount of sedimentation

within the typical geologic provinces of

NORTH AMERICA

during Cambrian time 

by

C.D.WALCOTT

JlocftyMts.

I* 13 ^ 25

\ Middle. 

Lower n

THEORETIC SECTION flT CLOSE OF CAMBRIAN TIME.
WALCOTT.] SYNOPSIS. 365

Secular disintegration Lad prepared an immense amount of material 

for the advancing sea to assort and rearrange in early Cambrian time. 

This, with that worn from the solid rocks by the attack upon the coast 

line, was largely disposed of prior to the opening of the limestoneforming period an epoch varying in relative time in the various 

provinces.

I do not think it probable that any considerable amount of sediment 

accumulated in the southern portion of the Interior Continental area during early Cambrian time. The sections of the Champlaiu Valley, eastern 

Tennessee, Utah and Nevada, and of British Columbia prove the accumulation of from 10,000 to 12,000 feet of sediment along the eastern and 

western flanks of the pre-Cambrian continent before the sea deposited 

the formations about the Llano Hills of Texas, the Ozark Mountains of 

Missouri, and other portions of the Interior Continental Province. This 

evidence leads to the belief that the continent stood at a considerable 

elevation, and that.the great accumulation of sediment during late 

Algonkian and early Cambrian time resulted from the distribution of 

material worn from the shore by the waves and brought into the sea by 

the rivers of the Interior Continental region and the outlying ridges.1

DESCRIPTION OF PLATE H.

Map of the central portion of the North American continent, to illustrate the relative thickness of the strata composing the Cambrian group in the various geologic 

provinces. (The small ring with the dot in the center indicates the geographic location of the hase of the section.)

The sections are grouped into the following geologic provinces: 

Atlantic Coast Province. 

Appalachian Province. 

Rocky Mountain Province. 

Interior Continental Province.

The latter consists of the Central Interior or Upper Mississippi, the Western or 

Kooky Mountain, the Southwestern or Arizona and Texas, and the Eastern or Adirondack sub-provinces. 

ATLANTIC COAST PROVINCE :

SECTION 1. Conception Bay, Avalon Peninsula, Newfoundland. The Cambrian rocks 

of the Avalon Peninsula rest un conform ably upon strata of Archean and Algonkian 

age. The section represented is formed by the union of portions of those of Manual's 

Brook, Kelly's, Great Bell, and Little Bell Islands.

SECTION 2. Vicinity of St. John, New Brunswick. This section is nucouformably 

superjaceut to the Archean, and unites the section at the city of St. John and that 

of Hanford's Brook.

1 It is not improbable that the area of the great coastal plain of the Atlantic slope was then an elevated portion of the continent; and that much of the sediment deposited during Cambrian and later 

Paleozoic time was washed from it into the seas immediately to the west. If this bo true the source 

of much of the sediment of the Appalachian series of rocks is accounted for and the absence of the 

deposits of the eastern coastline is explained by the sinking of the coastal region during, or at tho 

close of Paleozoic time. This view is strengthened by the presence, in tho Middle Cambrian fauna 

of Alabama, of a number of species that are closely allied to if not identical with species of the Middle Cambrian fauna of Newfoundland and Sweden. This fauna is unknown in.tho Appalachian Province north of Alabama. This leads to the inference that it was distributed along the shore of the 

Atlantic Coast Province, and that the line of deposits, uniting the Newfoundland and Alabama areas, 

south of the Massachusetts area, are now buried deep boueath later deposits.
366 THE CAMBRIAN. [BULL.81.

SECTION 3. Vicinity of North Attleoorough and Sraintree, Massachusetts. In this 

section the Lower Cambrian series of North Attleborough and the Middle Cambrian 

of Braiutree are united in one generalized section. The basal series is uncon form ably 

super)acent to the Archean. 

APPALACHIAN PROVINCE:

SECTION 4. North side of the Straits of Belle Isle, Labrador. The base rests unconformably upon the Archean.

SECTION 5. Central western Newfoundland. The base rests uuconformab'ly upon the 

Archean, but the summit of this section is not clearly defined owing to lack of data 

to determine the range of the fauna.

SECTION 6. Franklin County, Vermont. This represents the "Red saudrock" series, 

with its superjaceut Georgia shales, in the township of Georgia. The base is cut off 

by a fault line, and the exact limitation at the summit is unknown.

SECTION?. This represents the great shale and slate section of Washington County, 

New York. It is cut off at the base by a fault line and the summit is not well defined.

SECTION 8. The shore-line deposits of the Green Mountains or the " Granular 

Quartz," above which come limestones in which Cambrian fossils have been found. 

At the base it rests unconformably upon the crystalline pre-Cambrian rocks.

SECTION 9. Typical section in southern Pennsylvania, showing the " Granular 

Quartz" resting unconformably upon the subjacent crystalline rocks and extending 

above into the shale series beneath the limestones.

SECTION 10. This section is that of central Virginia, not far away from the shore 

line. The base rests nnconforniably upon the pre-Cainbrian rocks, and above it passes 

into the base of the " valley " limestones.

SECTION 11. Eogersville, East Tennessee. The base of this section is cut off by a 

fault line and above it passes into the Kuox dolomite, the lower beds of which carry 

the Upper Cambrian fauna. The Chilhowee Mountain section comes beneath the 

Rogersville, and it is so represented in this section. An interrogation point marks 

the hiatus between the two sections. The data for this section are given by Mr. Bailey 

Willis, chief of the Appalachian division of geology, U. S. Geological Survey.

SECTION 12. The line of this section extends from Rome, Georgia, westward into 

Alabama. At the base it is cut off by a fault and above is delimited by the Knox 

dolomite. The data for it are given by Mr. C. Willard Hayes, of the Appalachian 

division of the U. S. Geological Survey.

SECTION 13. Western slope of the Wasatch mountains, Utah. In this section the 

12,000 feet of quartzite and siliceous slates are tentatively referred to the Cambrian. 

The fossiliferous zone is confined to the upper 250 feet.

SECTION 14. Central eastern Nevada. This section represents the great quartzite 

series beneath the fossiliferous Cambrian limestone. The base has been concealed, 

and the summit has been removed by erosion.

SECTION 15. Eureka District, Nevada. In this section the fossiliferous Lower Cambrian strata rest s conformably upon the quartzites, which pass down some 1,500 feet 

before being concealed. The quartzites may correspond to the upper beds of section 

14. The summit of the section passes into the superjacent Pogonip limestone of the 

Silurian (Ordovician).

SECTION 16. Gallatin River near G-allatin City, Montana. This is essentially the 

same as the Mount Stephen section of British Columbia (section 17). The subjacent 

series of quartzites and siliceous slates are tentatively included in the Cambrian.

SECTION 17. Mount Stephen section of British Columbia, in connection with the 

subjacent Bow River quartzite and siliceous slates. The relations of the section are 

the same as those of the Eureka section (15) of central Nevada, with the addition of 

the Bow River quartzite and slates.

ROCKY MOUNTAIN PROVINCE:

Central Interior Continental subprovince:

SECTION 18. The western section of the central Interior Continental Province as 

it occurs in Minnesota.
WALCOTT.J SYNOPSIS. 367

SECTION 19. Section of the Upper Cambrian sandstones of eastern Wisconsin.

SECTION 20. Section of southern central Wisconsin, showing the unconformity 

between the Upper Cambrian and the subjacent Algonkian and Archean rocks. Sections 18, 19, and 20 are all of Upper Cambrian age, and pass conformably above into 

the superjaceut Lower Silurian (Ordovician) or maguesian limestones.

SECTION 21, Osark Mountains, southeastern Missouri. The relations of the Cambrian and the Archean are the same as those in the Black Hills section (section 23)-

Eastern or Adirondack snbproviuce:

SUCTION 22. The eastern and northern slopes of the Adirondack Mountains of New 

York. In this section the Potsdam sandstone of the Upper Cambrian rests unconformably upon and against the Archean and Algoukian rocks.

Western Interior Continental or Eocky Mountain sub-province:

SECTION 23. Black Hills, Dakota. The Upper Cambrian rests unconformably upon 

the Archean.

SECTION 24. Eastern section of Big Horn Mountains of Wyoming. It is essentially 

the same as that of the Black Hills (section 23).

SECTION 25. Southern Montana. This section is very much like that of Wyoming and of the Black Hills.

SECTION 26. Central Colorado.-^A. section representing the sandstones that lie between the subjacent unconformable Archean or Algonkian rocks and the superjacont 

Lower Silurian (Ordovician).

Southwestern Interior Continental sub-province:

SECTION 27. Grand Canon of the Colorado, northern Arizona. In this section the 

Cambrian strata are nncomformably superjacent to rocks of Algonkian age.

SECTION 28. Llano County, Texas. This section is similar to that of the Grand 

Canon in having an unconformity between the Algonkian and the Cambrian and in 

representing nearly the same geologic horizon.

Theoretic sections at close of Cambrian time. The data for these sections are obtained from the associated map. The enormous accumulation of sediment in the 

Eocky Mountain Basin on the west and the Appalachian Basin or trough on the 

east are shown, as well as the thin mantle of sediment over the great interior. It 

serves to illustrate the sedimentation indicated by the vertical columns on the map.

Our knowledge of the sediments of the eastern and western sides of 

the pre-Gainbriau continent is considerable, but of that deposited along 

the southward-facing front we know nothing. From the fact, however, that the same species of fossils occur in the Lower Cambrian 

fauna of Labrador, Massachusetts, New York, Vermont, probably 

Tennessee, Nevada, and British Columbia, I think we may hypothetically assume tlie continuance of the Lower Cambrian beneath the deposits of the Gulf States and westward through Texas, New Mexico, 

and Arizona. There is no known line of Lower and Middle Cambrian 

sedimentation across the continent to the north of this which indicates 

that the fauna might have been distributed along a more northern 

shore.

The pre-Cambriaii ridges, or protaxis of the present ranges of the 

northeastern side of the continent, have been outlined by Prof. J. D. 

Dana from the known exposures of pre-Cambrian rocks.1 The Paradoxides fauna lived in the depression between two of the eastern ridges 

of the Atlantic Province in the New Brunswick area, and in the bays

'Areas of continental progress in North America and the influence of the condition of these areas on 

the work carried forward within them. Bull. Geol. Soc. Am., vol. 1,1890, pp. 36-39.
368 THE CAMBRIAN. [BULL.81.

aud protected shores of the seaward slope of the western ridge, where 

the outer or eastern ridge was absent, as in Massachusetts and Newfoundland. The sediments that accumulated to the eastward of the 

New Brunswick sea form the supposed Cambrian shales and slates of 

Nova Scotia. The inner ridges of Maine, New Hampshire, and Massachusetts bounded long, narrow seas, in which the Cambrian faunas are 

not known to have penetrated. The Lower Cambrian fauna probably 

passed from the Atlantic along the ancient Labrador shore into the 

interior Appalachian sea. A few types of the Middle Cambrian fauna 

followed, and then the passage appears to have been closed, as none of 

the Upper Cambrian types of the Atlantic fauna have been found in 

the deposits of the interior seas.

The various views, both theoretical and hypothetical, relating to the 

pre-Cambrian continent are embodied on the map, PI. in, and the section at the base of PL n.

*

DESCRIPTION OF PLATE HI.

Hypothetical map of the North American Continent at the beginning of and during Lower

Cambrian time.

This map is based upon the sections shown on PI. 11, and the theoretic section at 

the base. The position of the sections on the two maps is indicated by a circle with 

a corresponding number on each map.

The shaded portions indicate the relative areas that are supposed to have been 

above the ocean during later Algoukiau and Lower Cambrian time. A comparison 

with PI. n shows that in the Rocky Mountain and Appalachian areas there was an 

enormous accumulation of sediment prior to the Upper Cambrian; while over the 

broad interior there is only the Upper Cambrian which corresponds to the upper portion of the great sections of the Rocky Mountain and Appalachian areas. In the 

region of the Atlantic Coast Province the continental movement seems to have been 

less, as the sediments of the Lower and Middle Cambrian are much thinner than 

those of the corresponding horizon in the Appalachian and Rocky Mountain areas. 

The conclusion is that the shaded portions and perhaps other unknown areas formed 

the land during late Algonkian and early Cambrian time, and that about the close 

of the Middle Cambrian or the beginning of Upper Cambrian time the continental 

surface was largely depressed beneath the waters of the ocean and the Upper Cambrian sediment accumulated over the entire area where Cambrian rocks are now 

known to occur. (See distribution on PI. i.)

On PI. in, A., Archean; K., Keweenawan; B. H., Black Hills of Dakota; T., Llano 

area of Texas ; M., Ozark uplift of Missouri; C., Grand Canon area of Arizona. The 

area marked X, X, X indicates an hypothetical land area of the existence of which 

we have not at present any absolute proof, as it is now covered by sediments of later 

age than the Cambrian.

The present shore outlines of the continent are indicated by the dotted line, and the 

outlines of the continental plateau_on the division between the deep sea and the continent by a continuous line.

The descriptive notes of the Cambrian rocks of the various provinces 

and the r6suni6 following each establishes the fact that in Cambrian 

time there were geographic areas in which different types of sedinienta-
U. 8. GEOLOGICAL SURVEY BULLETIN NO. 81 PL. III.

> \ V'M \

\ ^-v-^°-'/

' "

n'i nT^TTi'iTi'i'iTl'iTi'n Vi'ri'i'l'iVi'i S'-H''-'- r|.i|l|l|l|ljljT|l|l|i|l|lil|l|lililil|l|l|l|lj ilililili 1 )!) 1 ! 1 ! 11 ^sffi'' X

. 1,1,1,1.i,|,i.I.LUJ,i.i.i..i,u,i,i' 1,1,1,1,1,1,1,1,1,8,^3, r /^

HYPOTHETICAL MAP 

 of the

NORTH AMERICAN CONTINENT

at the beginning of 

LOWER CAMBRIAN TIME

by

C.D.WALCOTT 

 r.---i'v, 1691

'I'l'i'i'i'r 111II 1,1 ' Ji.-« -"*-. i\ 'i f ,.N '

u!|ljJ>U <> -> xv } >' ---..yJr-v ^~\
SYNOPSIS. 369

tioii prevailed, and that great variation existed in what are considered 

the same geographic provinces. The sediments of the northeastern 

Atlantic Coast Province are almost entirely shales with a small proportion of sandstone and a trace of limestone. Tracing the long Appalachian Province from the Gulf of St. Lawrence to the southwest and 

south, we find an immense accumulation of shale with some interbedded 

sandstone and limestone. This extends to the Lake Champlain region 

of New York and Vermont, where a great limestone of Lower Cambrian 

age is subjacent to several thousand feet of shale in which lenticular 

masses of sandstone arid limestone occur at irregular intervals. Farther 

to the southwest, in southern Vermont and eastern New York, great 

thicknesses of argillaceous sediment were deposited. These now form 

the series of shales in which beds of finely laminated rooting slates 

occur in massive strata. Toward the east, near the pre-Cambrian shore 

line, the Lower Cambrian sandstones are followed by arenaceous, dolomi tic, and purely calcareous limestones of later Cambrian time. This 

condition of sedimentation continues far to the south, varied more or 

less by the presence of great thicknesses of shale above the lower 

quartzite. In the latter case the limestone of the Cambrian forms only 

a thin belt at the summit.

In the Eocky Mountain Province the siliceous sediments, sandstones, 

and quart zites are followed by limestone, and nearer the shore line, 

the sandstones are subjacent to shale. Over the Interior Province the 

record is sandstone, followed on the west and southwest by alternating 

limestones and sandstones.

On the map (PI. 11) the thickness and character of the sediment is 

shown in a general manner for each of the provinces.

The study of the fauna has shown that, while there is a general resemblance in the faunas of the Lower Cambrian in the Atlantic Coast, 

Appalachian, and Kocky Mountain Provinces, there is sufficient differentiation to mark off distinct faunal areas in the early Cambrian sea.

The fauna of the Upper Cambrian is less specialized over great areas 

than that of the Lower and Middle zones. The opportunities for communication between the provinces were greater and it is only in the 

Northeastern or the Atlantic Coast Province that a marked difference 

is shown.

The Middle Cambrian fauna of the Atlantic Coast Province is so 

strongly differentiated from that of the Appalachian and Western 

Kocky Mountain Provinces that it was not until they were found to occupy the same relative stratigraphic position that it was suspected they 

lived in approximately the same epoch.

The evidence of sedimentation and the evidence of organic remains 

unite to prove that in Cambrian time -the geographic and faunal provinces were differentiated and established over the area of the present 

North American continent. In fact, the sedimentation of the Cambrian was as varied as that of many of later geologic periods and more 

so than that of the immediately succeeding Silurian (Ordovician). 

Bull. 81 24
370 THE CAMBRIAN. [BULL. 81. 

SUBDIVISION OF THE CAMBRIAN.

In his admirable report upon the Devonian of North America Prof. 

H. S. Williams expresses this opinion:

The subdivision of any great geological system must depend in great measure 

upon the differences in the faunas or floras contained, and, as I believe, this depends 

in no small degree upon the geological changes which modified and shifted the geographical conditions under which the animals lived. A sandstone will not contain 

the same species as a following limestone, and even in arenaceous shales a slight 

change in the fineness or coarseness or in the amount of argillaceous rnud mixed 

with the sand modifies the composition of the fauna contained in it. 1

There are not at present sufficient available data from the Cambrian 

upon which to base comparisons with the same degree of refinement as 

those made by Prof. Williams. It has been discovered, however, that 

the predominant types of life of the Cambrian group are to be found in 

shales, limestones, and sandstones. For instance, the genus Olenellus, 

characteristic of the Lower Cambrian, is found in the shales, limestones, 

slates, and sandy shales of the typical section in Northern Vermont. 

I have found in the quartzites and in the pure limestones of the Potsdam epoch of the Adirondack subprovince the same species of Dikelocephalus, Hyolithes, and Lingulepis. In the dark argillaceous shales 

of the Middle Cambrian terrane of Newfoundland I found the same 

species of Paradoxides that occurs in the interbedded limestones of 

the same series a few miles distant. That Prof. Williams is correct in 

relation to the great mass of organisms that existed during Paleozoic 

time there can be very little if any question. As an example the corals 

of the limestones of the north shore of the Strait of Belle Isle, on 

the Labrador coast, are unknown, except in an almost identical limestone at Silver Peak, Nevada, in the Rocky Mountain Province. It is 

in the clearer limestones that the great bulk of the brachiopods, 

pteropods, and other forms of life are found in the Cambrian j but it is 

a fact, nevertheless, that the predominant types of the Trilobita, characterizing its three divisions, flourished upon and were imbedded in 

sediments of widely different character. It is owing to this that they 

become of so much importance as criteria in the correlation of the three 

primary divisions of the group.

In the Atlantic Coast Province the fauna of the Lower Cambrian, or 

Olonellus zone, occurs in arenaceous limestones, pure limestones, and 

shales. All of these are of a different character from those of the black 

shales 200 feet above, in which the Paradoxides or Middle Cambrian 

fauna occurs. The Upper Cambrian fauna is found in dark shales and 

sandstones several hundred feet, if not a thousand feet, above the Paradoxides zone. The three primary subdivisions of the Cambrian are 

strongly defined by the sedimentation and faunas. In the St. Lawrence

1 International Congress of Geologists, American Committee. Report of tlie subcommittee to the 

session of the Congress held in London, September 17, 1888. Philadelphia, 1888. Report of the subcommittee on the Upper Paleozoic (Devonio), H. S. Williams, Reporter, p. C 20.
WALCOTT.] SYNOPSIS. 371

Valley area of the Northern Appalachian Province the Lower Cambrian 

and Upper Cambrian faunas are found in separate bands of conglomerate limestones and not in situ, the great thickness of shales and sandstones referred to the Cambrian not being characterized by any known 

fauna. In Vermont the Lower Cambrian fauna occurs throughout the 

classical " Eed sandrock " series and the lower portion of the superjacent Georgia shales, while about 2,000 feet above, the Upper Cambrian fatuna is well determined. The Middle Cambrian fauna has not 

been recognized. In the eastern New York section the Lower Cambrian fauna is strongly differentiated and the base of the Middle Cambrian fauna indicated; but the Upper Cambrian fauna is unknown. 

Only a few miles distant to the west, however, at the base of the Adirondacks, the Upper Cambrian fauna characterizes sandstones and 

limestones that occur beneath the base of the Silurian (Ordovician). 

Farther to the south, in Dutchess County, in the valley of the Hudson, 

the Lower Cambrian fauna is recognized in the basal quartzite and the 

superjacent limestone, and also the Middle Cambrian of the Appalachian and Eocky Mountain Provinces, and the Upper Cambrian of all 

but the Atlantic Coast Province. In Tennessee, in the Southern Appalachian Province, the Lower Cambrian fauna is found in shales, within 

the quartzite series, and at the summit of the shales the Upper Cambrian fauna occurs. This extends up and into the base of the limestone. 

In Alabama, in shales apparently occupying the same serial relation, 

the Middle Cambrian fauna is well developed.

In the Nevada section the Lower Cambrian or Olenellus zone is distinctly defined, and between it and the Upper Cambrian fauna 1,000 

feet of limestone is marked by types of the Middle Cambrian fauna. 

These distinctions of faunas are readily determined wherever two or 

more of them are present in the same section in the Eocky Mountain 

Province. In British Columbia the Lower Cambrian and Middle Cambrian faunas have alone been recognized.

I have spoken of the Middle Cambrian fauna of the Atlantic Coast 

Province and that of the Middle Cambrian of the Appalachian and 

Eocky Mountain Provinces. This distinction is made because the characteristic types of the Atlantic Coast Middle Cambrian fauna are not 

found in the Middle Cambrian fauna of the other two provinces. This 

indicates that a nearly impassable barrier existed during Middle 

Cambrian time between the sea of the Atlantic Coast Province and 

those of the interior. This prevented nearly all the species of the 

former from migrating into the Appalachian and Eocky Mountain Provinces. Within the two latter there is a fauna characterized by similar 

types in New York, Alabama, Nevada, and British Columbia, and in 

each section where their stratigraphic position is determined they 

occupy the same relations to the Lower and Upper Cambrian faunas 

as does the Middle Cambrian or Paradoxides fauna of the Atlantic Coast 

Province.
372 THE CAMBKIAN. IBULL.SI.

The Lower Cambrian fauna is much more persistent in its character 

than that of the Middle Cambrian; for all the strata referred to the 

former horizon have been found to be characterized by essentially 

the same fauna. This is also true of the much more widely spread 

Upper Cambrian with the single exception of the Atlantic Coast Province, where the fauna is more of the European or Atlantic Basin type. 

There is, however, too little known of it at present in Newfoundland 

to base any final conclusions upon it.

The minor or formation subdivisions of the Cambrian are based largely 

upon lithologic characters and are relatively of local value only. One 

exception to this is found in the " Granular Quartz " of New York and 

Vermont, and the equivalent Chilhowee quartzite series of Tennessee, 

Alabama, Virginia, Pennsylvania, etc. Another is in the widely spread 

shore-line deposits, called the Potsdam sandstone in New York, the St. 

Croix sandstone in the Upper Mississippi Valley, the supposed equivalent deposits of the Black Hills of Dakota, the sandstones of the 

eastern flanks of the Rocky Mountains and of the Llano area of Texas. 

These two formations furnish illustrations of the accumulation of similar 

sediments over very extended areas. Their minor value in classification, when not supported by paleontologic evidence, is shown by the 

fact that the Lower Cambrian " Granular Quartz " or Chilhowee sandstone has been correlated by nearly all geologists who have referred to 

it with the Potsdam sandstone about the Adirondacks of New York 

and the St. Oroix sandstone of the Upper Mississippi Valley, thus 

briuging together formations separated in the stratigraphic column by 

a long time interval and several thousand feet of sediment. Other 

sandstones of pre-Cambrian and post-Cambrian age have also been 

correlated with the Potsdam sandstone of New York.

With our present knowledge of the faunas and sediments it is impossible in all instances to differentiate the primary divisions of Upper, 

Middle, and Lower Cambrian in America.

Extending our views across to the eastern side of the Atlantic Ocean, 

we find an extensive development of Cambrian rocks in North and 

South Wales, where the three great divisions of the North American 

Cambrian are to be recognized. The Lower, in the roofing-slate series 

of North Wales and the Caerfai group of South Wales; the Middle, 

in the Solva and Menevian formations, and the Upper, in the Lingula 

flags series. These divisions are also recognized in Sweden and North 

Wales, although in greatly diminished force. The Lower division has 

been recognized in western Eussia, and the central belt of the celebrated 

" Zone Primordiale" of Bohemia represents the Middle Cambrian series.

In lithologic, stratigraphic, and paleontologic characters the Cambrian series on the opposite sides of the Atlantic are such that there 'is 

no hesitancy in considering them as belonging to one geologic group 

and as part of one geologic basin.

There is a great variation in the sedimentation and faunas of the
WAT.COTT.J EUROPE. 373

various formations referred to the Cambrian in North America and 

Europe; they all fall within the limits of the group and, united, constitute a groat geologic division of equal taxouomic value with Silurian 

(Ot'doviciau), Silurian, Devonian, etc.

COMPARISON WITH THE CAMBRIAN ROCKS OF OTHER COUNTRIES.

EUROPE.

Dr. Henry Hicks expresses the view that the sediments of the Cambrian and Silurian were largely deposited on the western side of the 

European continent.1 In Spain and Wales the sediments accumulated 

to a great thickness, while to the eastward, in Bohemia, Scandinavia, 

and Russia, the sections show less than one-fifth of the thickness of 

those in Wales. In central Russia the Cambrian strata entirely disappear and the Silurian (Ordovician) rests unconformably and directly 

upon the Archean. These observations lead to the conclusions (a) that 

the Cambrian sediments were deposited upon a gradually sinking coast 

line; (&) that the greatest depression was on the western margin of the 

continent; (c) that the movement which depressed the North American 

continent during pre-Cambrian time also affected the western side of 

the European continent, with a gradually diminishing force, from the 

Atlantic coast to the Ural Mountains.2

A comparison of the Atlantic Coast Cambrian series of America with 

the Atlantic Coast series of Europe, as exhibited in Wales, shows a 

marked similarity between the sedimentation of the opposite sides of 

the Atlantic. The basal Cambrian in South Wales, named the Caerfai 

group, by Dr. Henry Hicks, consists of 1,570 feet of strata, as follows: 

520 feet of conglomerates and greenish sandstones subjacent to a bed 

of red shales and schists, 50 feet in thickness, above which 1,000 feet 

of purple sandstones occur. Dr. Hicks correlates the roofing slates of 

North Wales as found at Llanberris, Bethesda, and Penrhyn with this 

lower division of the Cambrian, on stratigraphic evidence, as the few 

fossils found are not sufficiently characteristic to correlate the two 

series with each other or with the American Lower Cambrian. A comparison of the sections with that of the southeastern coast of Newfoundland shows in each the presence of a basal conglomerate subjacent to a 

series of purple and green shales or slates. It is also to be noted that 

the Lower Cambrian of New Brunswick and eastern Massachusetts is 

made up of shales of a somewhat similar character to those of the Caerfai group. It is a curious coincidence that the section of the Lower 

Cambrian of North Wales is almost identical in the physical character 

of its slates, including color and texture, to the Lower Cambrian roofing slate belt of southern Vermont and eastern New York.

1 On the deposition of the Cambrian anil Lower Silurian rocks. Quart. Jour. Geol. Soc., London, vol. 

SI, 1875, PI. 27, op. p. 558.

2 Walcott, C. D.: The fauna of the Lower Cambrian or Olenellus zone. 10th Ann. Hep, U. S. Geol. 

Surv., 1890, pp. 503, 564.
374 THE CAMBRIAN. [BULL. 81.

The Solva group of South Wales consists of 150 feet of yellowish 

grits beneath 1,500 feet of gray, purple, and red rocks, above which 150 

feet of gray rocks occur. All three divisions are characterized by the 

presence of the genus Paradoxides. The superior division of the Menevian group consists of 750 feet of slates and sandstones, and, with the 

Solva formation, constitutes the Paradoxides zone corresponding to the 

Middle Cambrian of the American section. This division is represented in Massachusetts by the Paradoxides beds of Braintree, in New 

Brunswick by the Paradoxides shales of the St. John Basin, and in 

Newfoundland by the Paradoxides shales of the Avalon Peninsula. 

The faunas of this division are largely identical on the opposite sides 

of the Atlantic, and form the great connecting link that binds the 

sections together and permits of almost positive correlation between 

them.

The North American Upper Cambrian is represented in Wales by 

the Lingula flags arid Lower Tremadoc series, formed of over 5,500 

leet of bluish and black slates and flags with bands of gray flags and 

sandstones. The faunal and stratigraphic equivalent of this series has 

been distinctly recognized in New Brunswick, on Cape Breton Island, 

and on the Avalou Peninsula of Newfoundland.

Most English geologists have included the Tremadoc slates in the 

Cambrian j but from an examination of the list of their contained fauna 

it appears to me that the line of demarcation between the Cambrian 

and Silurian, if based upon the general facies of the fauna, should be 

drawn in the Tremadoc series between the upper and lower divisions. 

The fauna of the lower division is essentially that of the Cambrian, 

with a few genera and species more characteristic of the Lower Silurian (Ordovician), while the fauna of the upper division is largely of the 

Lower Silurian (Ordovician) type, with a few forms of the Cambrian intermingled with it.

The problem of the line of demarcation between the two groups in 

England is essentially of the same character as that presented in Nevada, where there is no clearly drawn stratigraphic or faunal break in 

the Pogonip series of limestones.

That there is a strongly marked resemblance between the Cambrian 

series of the Atlantic Coast Province of America and that of the 

western Atlantic Coast Province of Wales there is no question. We 

are able to compare the three main subdivisions and assume that 

they belong practically to one province. In fact, there is no more difference between the faunas and sediments on the opposite side of the 

Atlantic than there is in different portions of the Appalachian Province, and not as much as between different provinces on the North 

American Continent.

In explaining the strong similarity of the faunas and sediments of 

the Cambrian rocks of the opposite side of the Atlantic, Dr. Henry 

Hicks says:
WALCOTT. ] EUKOPE. 375

The home of the earliest forms of life seems to have been somewhere towards the 

southwest, and possibly not far from the equator; and it is from here that the various 

forms seem to have migrated to the areas in which they were subsequently entombed. 

The migrations seem to have taken place towards the North American continent very 

much about the same time as towards the European; and the sea encroachments 

along that continent seem to have been in a direction from southeast to northwest, so 

that the line indicating the two depressions would meet in mid-Atlantic. This accounts for the great similarity in the two faunas and for the general resemblance 

offered by the order of succession of these early rocks in the two continents. The 

higher lands in America would be to the west and northwest, and the higher lands 

in Europe to the east and northeast, so that the last lands submerged would approach 

each other and occupy the same region of the globe. 1

The Scandinavian Cambrian series is not over 200 feet in thickness, 

and represents the entire British series.2 It is divisible into the Lower 

Cambrian or Olenellus zone, the Middle Cambrian or Paradoxides zone, 

and the Upper Cambrian or Olenus zone.

On the opposite side of the Baltic, in eastern Bstoria, the Lower 

Cambrian zone alone is recognized by the presence of its characteristic 

fauna. The Middle and Upper Cambrian faunas probably existed in 

this region, but they have not as yet been discovered.

Beneath the Paradoxides zone of central Bohemia there is a considerable thickness of shales, grits, schists, conglomerates, and quartzites 

that may represent the Lower Cambrian. The Upper Cambrian, if it 

has not been removed by pre-Siluriau ero sion, does not appear to have 

been clearly differentiated from the Middle Cambrian or Paradoxides 

zone.3

The Cambrian rocks of the nqrth of France are correlated with the 

Cambrian of St. David's, Wales, by authors, but they are not sufficiently 

well defined by faunas to compare them with American formations. In 

the province of He"rault, in the south of France, the presence of Paradoxides correlates the rocks with the Cambrian of Bohemia.4

On the island of Sardinia there is a mixture of Middle and Lower 

.Cambrian faunas, which may arise from the confused state of the strata, 

or it is not impossible that the faunas are really mingled in the same 

beds. In the absence of more definite data it is not practicable to compare them with the American sections.

The contrast between the American and European Cambrian, with 

the exception of the sections of Bohemia and Sardinia, are not as great 

as those between the Atlantic Coast Province and the Appalachian 

Province, or as between the Atlantic Coast and Kocky Mountain Prov1 On the deposition of the Cambrian and Lower Silurian rocks. Quart. Jour. Geol. Soc., London, vol. 

31.1875, p. 555.

2 See Prof. Charles Lapworth's comparative table of the Cambrian rocks of Britain and Scandinavia. 

"Materials for the Correlation of the Lower Paleozoic Rocks of Britain and Scandinavia." Geol. 

Mag., now series, dec. n, vol. 8, 1881, pp. 320,321.

3 Mr. J. B. Marr correlates the basal beds of Barrando's Utage D (d la) in which Lingula feistmanteli 

occurs in abundance, with the Lingula flags of Britain. Quart. Jour. Geol. Soc., London, vol. 36,1880, 

p. C02.

"Bergoron, Jules: Note sur la presence de la Faune primordiale (Paradoxidion), dans les environs 

do Ferrals-les-Montagnos. Bull. Soc. geol. Franco, 3° s6r., vol.. 16,1888, pp. 282-285.
376 THE CAMBRIAN. [BULL. 81,

inces. In point of fact the Atlantic Coast Province of America is 

practically a portion of the Atlantic Province of which the sections of 

western Europe are on the eastern side. The Bohemian area and that 

represented by the deposits on the island of Sardinia partake, in part, 

of the character of the Atlantic Basin deposits, in the presence of the 

Paradoxides fauna, but not in other details.

The essential difference between the English and the American classification is in drawing the line between the Cambrian and Silurian 

(Ordovician). The English geologists have included the Upper Tremadoc slates, with their strongly marked Ordovician fauna, in the 

Cambrian, because a local stratigraphic break occurs at their summit 

and between it and the subjacent Arenig series. By the definition 

adopted in this paper for distinguishing the great geologic groups, the 

Upper Tremadoc slates, with their fauna, would be included in the Silurian (Ordovician), and the line of delimitation between the Cambrian 

and the Silurian (Ordovician) be drawn at the base of the upper Tremadoc slates, thus referring the Lower Tremadoc and the Lingula flag 

series to the Upper Cambrian, and the Upper Tremadoc to the base of 

Silurian (Ordovician).

In conclusion: (a} The relations between the Cambrian rocks of the 

eastern or Atlantic coast of North America and those of Wales are of a 

genetic character, and point to their having been deposited in the same time 

interval; (&) the Scandinavian Cambrian represents the same interval, 

but with a greatly diminished bulk of sediments; (c) the French and 

Spanish sections are too incomplete for close comparison, although 

representing the coast of Wales series; (d) the Bohemian and Sardinian 

areas point to local conditions that may have affected their connection 

with the typical Atlantic Basin sediments and faunas.

SCOTLAND.

The occurrence of Cambrian rocks in Scotland has not yet been fully 

proved, but it is quite probable that the Torridon sandstones of northwestern Scotland may be referred to the Lower Cambrian. Prof. Archibald Geikie, in summing up the notice of the Cambrian rocks in 

Scotland in his Text Book of Geology, says:

In the northwest of Scotland a mass of reddish brown and chocolate-colored sandstone and conglomerate (at least 4,000 feet thick in the Loch Torridou district) lies 

unconformably upon the Archean gneiss in nearly horizontal or gently inclined beds. 

* * " The denudation must have been considerable even in early Silurian 

times, for the sandstones are unconformably overlaid by quartzites and limestones 

containing Lower Silurian fossils, and these younger strata even in the same district 

rest directly on the Archean gneiss. * * * No trace of organic remains of any 

kind has been found in the red sandstones themselves, unless certain track-like impressions, observed on the west side of Loch Maree, can be regarded as having been 

imprinted by Crustacea or other organisms. 1

1 Text Book of Geology, 1885, p. 653.
WALCOTT.] IRELAND CHINA. 377

IRKLAJO).

The supposed representative of tlie Welch Cambrian series in tlie 

southeast of Ireland is described by Prof. Geilde as follows:

In the southeast of Ireland, masses of purplish, red, and green shales, slates, grits, 

quartzites, and schists occupy a considerable area and attain a depth of 14,000 feet 

without revealing their base, while their top is covered by uuconforruable formations 

(Lower Silurian and Lower Carboniferous). They have yielded Oldhamia, also numerous burrows and trails of annelides (Hintioderma hibernicum, drenicolites didymus, A. 

sparsus, Haughtonia pcecila.) No Upper Cambrian forms have been met with in the 

Irish rocks, which are therefore placed with the Lower Cambrian, the nncouformability at their top being regarded as equivalent to the interval required for the deposition of the intervening formations up to the time of the Llaudeilo rocks, as in the 

northwest of Scotland. 1

A very full description of the Cambrian rocks of Ireland, especially 

as they occur at Bray Head, Wicklow, is given by Prof. William flellier 

Baily in 1865. A diagrammatic section accompanies the paper, and the 

author also describes the supposed organic remains that have been 

found in the rocks.2

CHINA.

Our knowledge of the Cambrian rocks of China results from the 

investigations of Baron Eichthofeu in the province of Liau-tung in northeastern China, near the Corean frontier. He found a series of limestone containing the "Primordial" fauna in the sections of Sai-maki 

and Tai-tsze-ho.3 The limestones are superjacent to a series of sandstones and quartzites that correspond in stratigraphic position to the 

Lower Cambrian of Forth America.

The collections of fossils were studied by Dr. Wilhelm Dames, who 

came to the conclusion that two horizons were represented the Andrarum limestone or Paradoxides ^horizon of Sweden, and the Quebec 

horizon of North America.4 At the time Dr. Dames wrote DiTceloc&phaltis gothicus and D. quadriceps, which he referred to the genus Doropyge, were cited as from the Quebec group; and it was on the comparison between the Doropyge richthofeni and these two species that he 

considered that the Quebec horizon was represented. The two species 

mentioned are now referred to the genus Olenoiues of the Middle Cambrian fauna, which is not known to occur in the Upper Cambrian or in 

the Calciferous-Chazy fauna corresponding to the Quebec. A study of 

the species illustrated by Dr. Dames leads me to think that the Middle 

Cambrian fauna only is present, although it is not impossible that 

some Upper Cambrian species may have been collected. The sections 

of Baron Richthofen, however, indicate a considerable thickness of con1 Text Book of Geology, 1885, p. 654.

8 The Cambrian rocks of the British Inlands, with especial reference to the occurrence of thin formation iind its fossils in Ireland. Geological Msigazine, vol. 2, 18U5, pp. 385-400.

3 llu;lit,liofeii, F. F. von: China. Jirjjebnisse eigeiior Keisuu mid tlarauf gtmrnndetor Studien. Vol.2 

(das nordliche China) fig. 21, p. 94; fig. 29, p. 101, 1882.

"Cauibrische Trilobiten von Liau-tung. Chiiia; by F.F. von Kichthofen, vol. 4, 1883, p. 33.
378 THE CAMBRIAN. [BULL.81.

formable strata beneath the Middle Cambrian zone in which the Lower 

Cambrian or Olenellus fauna should be sought for, and there are beds 

above in which the Upper Cambrian fauna may possibly be discovered. 

The geologic section is to be compared to that of the Eocky Mountain 

Province, and the presence of the same peculiar Middle Cambrian 

fauna, unmarked by the genus Paradoxides, also strengthens the comparison.

INDIA.

In a note on the discovery of trilobites by Dr. H. Warth in the 

Neobolus beds of the Salt Eange, by Mr. Will King, director of the 

Geological Survey of India, 1 it is stated that the trilobites were discovered in the Neobolus beds of the Salt Eange. The stratigraphic 

succession, from the summit downward, beneath the Carboniferous 

limestone, is as follows: 2

S

7. Eed shaly zone (Salt-pseudomorph zone). 

6. Magnesian sandstone. 

5. Dark shaly zone (Neobolus beds).

T4. Upper purple sandstone (purple sandstone). 

Pnrple .,and,toue group. | g*^^^^ ""1 "- 

1^1. Lower purple sandstone.

There had been previously discovered in the Neobolus beds by Dr. 

Warth and Dr. Waagen a number of brachiopods, which were described 

by Dr. Waagen as follows: Discinolepis gramilata (p. 750), Schizopholis 

rugosa (p. 753), Neobolus warthi (p. 758), N. wynnei (p. 759), Davidsonella 

linguloides (p. 764), D. squama (p. 766), lAngula, Jciurensis (p. 768) and L. 

warthi (p. 769).3

It is stated that the trilobites were sent to Dr. Waagen, who identified 

one of the two determinable species as a Conocephalites, very nearly 

related to ConocepJialites formosus Hartt, from the St. John group, and 

the other as probably an Olenus.

The beds in which such forms occur can not be anything but Cambrian, and they 

must probably be classed as referable to the upper region of the Lower Cambrian.4

In the table the probable equivalent elsewhere of this formation is 

the Sinic formation of Eichthofen, in China.5

AUSTRALIA.

The Cambrian rocks of Australia appear to be confined to the southeastern portion of South Australia and the northern portion of Tasmania. In the "Papers and Proceedings of the Eoyal Society of 

Tasmania for 1882," Mr. E. Etheridge, jr., described a species of Conocephalites which he named Conocephalites f stephensi (p. 153), and the 

tail of a trilobite which is named Dikeloceplialus tasmanicus (p. 155).

1 Records of the Geological Survey of India, vol. 22,1889, pp. 153-157.

* Op. cit., p. 157.

3 Memoirsof Geol. Surv.,India. Palseontologia Imlica, ser. xiii, vol. 1,1887,pp.760-770.

* Records of the Geological Survey of India, vol. 22,1889, p. 154.

*Op. cit., p. 157.
WALCOTT.I SOUTH AMERICA. 379

Another pygidium is identified as belonging to the genus Asaphus, and 

small univalves which have the appearance of the genus Ophileta, of 

Vauuxem.1

The trilobites and the gasteropods are correlated with the Upper 

Cambrian fauna of America and Great Britain, to the Potsdam sandstone in America and the Lingula flags of Wales.

In 1884 Dr. Henry Woodward described some trilobites from the 

Parara limestone of the Yorke Peninsula, South Australia, Conocephalites amtralis and Dolicliometopus tatei.2 He concludes that the trilobites are clearly of Lower Silurian age, being equivalent to the Swedish, 

Bohemian, Tasmaniau, and North American beds with similar fossils.

A recent paper by Mr. E. Etheridge, jr., on some Australian species 

of the family Archseocyathiuse describes the presence of several species 

of .that family in association with trilobitic remains at Ardrassan, Yorke 

Peninsula, South Australia. The species described are Ethmoplvyllum 

hindei, Protopliaretra ? scoulari and Coscinocyathus tatei.3

The strata containing the fossils are correlated with the Potsdam 

horizon sandstone of America or the Lingula flags of Wales. From 

the stratigraphic position of the American forms of Ethmophyllum 

and Coscinocyathus it is quite probable that the Australian species 

belong to the Lower Cambrian fauna and not to the Upper, as identified by Mr. Etheridge.

SOUTH AMERICA.

In 1876 Dr. Emanuel Kayser described a small collection of Primordial fossils made in the northern portion of the Argentine .Republic, in 

the provinces of Salta and Jujuy, by Prof. Lorentz and Dr. Hyeronirnus, of Cordova. The fossils occur in a micaceous sandstone, and include the genera Lingula, Obolus, Orthis, Hyolithes, Arionellus, Agnostus and Olenus.4 Dr. Kayser compares the fauna with that of the north 

of Europe and North America, and concludes that it belongs to the upper 

zone of the Primordial. He calls attention to the fact that the genus 

Paradoxides is wanting and that Olenus appears in great numbers. 

"This fact seems to indicate that our fauna belongs to the upper Primordial zone or the Olenu s stage."5

A glance at PI. I, of Dr. Kayser's memoir proves that he is correct in 

the reference and that the fauna is of the type of the Upper Cambrian. 

From the geographical position and character of the fauna it is quite 

probable that Cambrian formations will be found on the eastern slope 

of the Andes, as well as the Cordillera of Central America and Mexico, 

if not concealed by later deposits.

'Papers and Proc. Royal Soc. Tasmania for 1882,1883, pp. 151-158.

2 Note on the remains of trilobites from South Australia. Gool. Mag., new series, dec. in, vol.1, 

1884, pp. 342-344.

3 On some Australian species of the family Archaeocyathinfe. Trans. Hoy. Soc. Soutk Australia, 

vol. 13,1890, pp. 10-22, Pis. n and ill.

4 Beitriige zur Geologic uud Palaeontologie der Argentinischen Republik; n. Palaeontologische 

Theil.; von Dr. Emanuol Kayser, Cassel, 1876, pp. 28.

6 0p.cit.,p.29.
CHAPTEK V.

PROBLEMS FOR INVESTIGATION AND SETTLEMENT.

I. Local problems within the subdivision of each province.

II. Problems affecting our knowledge of the Cambrian group as a whole or in large parts.

III. Problems of nomenclature and classification.

LOCAL PROBLEMS.

There are many local problems that are not mentioned in the following notes. With the settlement of the more important questions they 

will assume prominence, and some of them may prove to be equal to 

if not of more import than those now suggested for investigation.

Newfoundland. The prominent questions are:

(1) The determination of the relation of the Cambrian rocks of St. 

Mary's and Trinity Bays to the basal conglomerate in the Manuel's 

Brook section, to ascertain if a series of Cambrian strata occurs between 

the lowest recognized Cambrian on Conception Bay and Manuel's Brook 

and the pre-Cambrian rocks of Trinity and St. Mary's Bay, as thought 

by the Newfoundland geologists. If such a series be found its fauna 

should be carefully collected and studied with reference to its being 

basal Cambrian or pre-Cambrian. .

(2) The discovery of an unbroken stratigraphic section to prove the 

assumed relations of the Paradoxides fauna to the Upper Cambrian 

fauna. This will probably be found in the vicinity of or on the shores 

of the peninsula west of St. Mary's Bay and the shores of Placentia 

Bay.

(3) The determination on the west and northwest sides of the island 

of the relations of the Olenellus bearing strata to the subjacent and 

superjacent beds and the character of the section from its base to the 

limestone carrying the Calciferous fauna of the Silurian (Ordovician).

(4) The study of the geographic distribution and detailed sections of 

the strata on the southwestern and northeastern coasts.

(5) The relations of the Cambrian strata to the superjacent beds of 

the Silurian (Ordovician) wherever they can be found in the same section.

Nova Scotia. The important question in Nova Scotia, as in Maine 

and New Hampshire, is the determination of the geological age of the 

slates referred provisionally to the Cambrian. After this come the 

local details of the sedimentation and paleontology of the Cambrian 

terrane. Until the first is decided very little except conjecture can be 

used in the correlation of the slates with the Cambrian or other groups. 

380
WALCOXT.] PROBLEMS FOE INVESTIGATION. 381

New Brumwicli. Through the efforts of Mr. G. F. Matthew many of 

the problems relating to the Cambrian system in New Brunswick have 

been, successfully solved. More information is needed for 

(1) The clearer identification of the Lower Cambrian or Olenellus 

zone and its exact stratigraphic relations to the Paradoxides zone.

(2) A clearer determination of the Upper Cambrian fauna and its relations to the Paradoxides zone.

(3) It is desirable that more data should be obtained upon the zoologic relations of the different faunas to each other.

Maine and New Hampshire. The problem presented in Maine and 

New Hampshire is essentially of the same character as that presented 

in Nova Scotia. It is the determination of the presence of rocks of 

Cambrian age by paleontologic evidence. Until this is done the other 

problems of stratigraphic succession and geographic distribution of the 

strata and faunas can not be considered.

Eastern Massachusetts. In eastern Mass achusetts it is desirable to 

ascertain 

(1) The stratigraphic relations of the strata carrying the Olenellus 

fauna and Paradoxides fauna and decide whether the Upper Cambrian 

is represented in the region.

(2) To obtain more paleontologic data in order to correlate the various outcrops that have been referred to the Lower and Middle Cambrian 

in different portions of the Boston Basin and to the south-southwest 

toward the Ehode Island line.

(3) To identify and map the Cambrian rocks in detail. 

Neiv York. In New York it is desirable to ascertain 

(1) The exact relation of the strata carrying the Olenellus fauna to 

those carrying the Upper Cambrian or Potsdam fauna about the Adirondacks.

(2) The stratigraphic succession and thickness of the strata carrying 

the Olenellus fauna in Eensselaer and Washington Counties, and 

whether the Middle and Upper Cambrian can be recognized either by 

the faunal or lithologic characters.

(3) The geographic distribution of the Cambrian rocks in the Hudson Valley south of Eensselaer County.

Adirondack subprovince. The most important problem in connection 

with this subproviuce is the tracing of the transition from the sandstone of the Potsdam about the Adirondacks to the off-shore deposit 

represented by the shales and slates now found beneath the limestone 

of the marble belt of western Yermont and eastern New York. More 

extensive collections of fossils are also desirable for the purpose of instituting closer correlations between the faunal zones of the typical 

Potsdam section of the Adirondacks with that of the correlated sandstone of the Mississippi Valley and elsewhere.

Vermont. In Vermont the problems presented for study in connection with the Cambrian rocks are somewhat of the same type as those
382 THE CAMBEIANo [BULL.81.

of New York. They differ in the northern portion, owing to the varying character of the sediment. Some of the questions are 

(1) The relation of the lower band of limestone (" Bed sandrock "), 

bearing the Olenellus fauna, to subjacent rocks.

(2) The relation of the shore deposits, forming the " Granular Quartz " 

on the western slope of the Green Mountains, to the off-shore deposits, 

forming the limestones ("Bed Sandrock") and shales (Georgia, etc.) 

carrying the Lower and Upper Cambrian faunas, in northern Vermont.

(3) The change in character of the sedimentation of the Cambrian 

rocks from the northern to the southern part of the State and their 

transition into the shale and slate series of New York.

(4) The determination of the extent of the range of the Cambrian 

fauna in the limestones of the " marble belt" in southern Vermont and 

the relations of these beds to the subjacent Cambrian strata on the 

western side of the " marble belt." The latter involves the question 

of the relation of the slates and shales carrying the Olenellus fauna and, 

in part, the base of what may be a portion of the Middle Cambrian 

fauna to the limestones. The working out of the complicated structural geology and the identification and mapping of all the formations 

will be required in the solution of these problems.

(5) The determination of the absence or presence of paleontologic 

data sufficient to differentiate the three primary divisions of the Cambrian group.

(6) The detailed geographic distribution of the formations referred 

to the Cambrian throughout the State.

Canadian extension. The Cambrian group on the line of the Canadian extension north of Vermont, in the vicinity of Quebec and down 

the St. Lawrence River, requires detailed study in all its parts, both to 

determine the stratigraphic succession and character of the beds and 

the relation of the strata to the subjacent and superjacent series. One 

of the important problems presented is the determination of the origin 

of the limestone bowlders in the Point Levis conglomerate that carry 

the Upper Cambrian fauna, and those of the Sillery shale that carry 

the Lower Cambrian or Olenellws fauna. In fact, the entire Cambrian 

group of this portion of Canada requires full investigation.

New Jersey. In New Jersey it is desirable to ascertain :

(1) The relation of the quartzite that has been referred to the Potsdam, to the subjacent Green Pond Mountain rocks.

(2) The representatives in New Jersey of the Pennsylvania Primal 

slates of Prof. Bogers.

Pennsylvania. In the State of Pennsylvania attention should be 

given:

(1) To determining, by paleontological evidence, the exact age of the 

quartzite which has been referred to the Potsdam sandstone by all 

authors.

(2) To a careful study of the upper Primal slate, for the purpose of 

determining the line of demarcation between the Cambrian and Silu-
WALCOTT.I PROBLEMS FOR INVESTIGATION. 383

rian (Ordovician) rocks. This, apparently, will have to be based upon 

the paleontological evidence, as the stratigraphic series is unbroken 

and there is a gradual gradation between the schists or slates and the 

limestone by the intercalation of calcareous beds in the shales until the 

latter predominate and form the limestone series. This investigation 

can probably be best carried on in York and Adams Counties and the 

western portion of Lancaster County.

(3) The relation of the quartzite to the subjacent rocks also requires 

careful investigation all along the line of contact of the two terraues.

(4) Another problem that requires investigation is whether the Primal slates and schists graduate into limestones to the east and northeast of Lancaster County, or whether there is a line of uucomformity, 

by non-deposition, between the quartzite and limestone in Chester, 

Berks, Backs, Lehigh, and Northampton Counties. In other words, 

whether the portion of the Cambrian section as found in York and 

Adanis Counties is absent in the counties to the northeast, or if it be 

represented by the lower portion of the limestone series.

Virginia. The knowledge of the stratigraphic position of the rocks 

referred to the Cambrian, in Virginia, is in a much more satisfactory 

condition than that of Pennsylvania. It is desirable, however, that 

attention be given to:

(1) The changes in the character of the sedimentation from the Tennessee line north to the Potomac, and also the changes in the character 

of the sediment between the shore deposits of sand and conglomerate 

and the off-shore deposits of shale and calcareous matter.

(2) The paleontologic evidence of the geologic age of the strata referred to the Cambrian, is very defective, and investigation in this line 

should be made throughout the State.

North Carolina. The problems to be considered in North Carolina 

are:

(1) The section along the French Broad, so as to determine the age 

of the strata and, if Cambrian, ascertain the stratigraphic position of 

the limestones, shales, sandstones, and quartzite to each other and to 

the sections of eastern Tennessee. e

(2) About the same problem is presented in the rocks on the line of 

the Biwassee section, in the southwestern portion of the State. 

Tennessee. The questions requiring investigation in Tennessee are:

(1) The stratigraphic relations of the Chilhowee formation to the 

Kuox sandstone and Shale series.

(2) The relations of the eastern shore deposits to the off-shore deposits 

westward of the pre-Cambrian rocks.

(3) The collection and the study of the faunas of the Chilhowee and 

Knox shale formations.

(4) The geographic distribution of the strata and the vertical range 

of the faunas.

Georgia and Alabama. The entire Cambrian section of Georgia and 

Alabama needs to be worked out stratigraphically, especially the rela-
384 THE CAMBKIAN. [BULL. 81.

tion of the Coosa Valley shales to the quartzites referred to the Chilhowee formation of Tennessee. The fauna of the shales is large and 

varied, and should be studied in connection with that of the Cambrian 

section of Tennessee and New York.

Utah and Nevada. The problems awaiting solution in the study of 

the Cambrian rocks of Nevada and Utah are of an unusually interesting 

character. Those that suggest themselves are:

(1) The study of the basal beds of the Ca mbrian, and the possible extension of the Olenellus fauna down into the quartzite series beneath 

what is now recognized as the Olenellus zone. From all that is known 

to me of the rocks in Nevada and Utah, I think that in western central 

Nevada the best opportunity will be found for the discovery of the 

faunas preceding the present recognized base of the Cambrian. During later Algonkian time there appears to have been a great accumulation of arenaceous and siliceous sediments along the line of the Wasatch and extending westward into central Nevada. In western Nevada 

they are more shaly and calcareous, and it is possible that the conditions under which they were deposited were more favorable for the 

presence and preservation of the life of that period.

(2) The careful and detailed study of the great Cambrian section of 

central Nevada for the purpose of determining the full sequence of life 

throughout. Our prese nt knowledge of it is very incomplete, and there 

are many gaps that ca n probably be filled in by detailed work and the 

careful collection of the fauna in connection with the study of stratigraphy and sedimentation.

(3) The study of the sections from the Wasatch westward to western 

Nevada for the purpose of determining the change of sedimentation and 

life from east to west.

(4) Another important subject of investigation is the transition between the Upper Cambrian and Ordovician faunas. This has been partially worked out in the Eureka district section, but there still remains 

much to be learned by careful detailed study of the sediments and 

faunas in the field.

(5) One of the unsolved problems of Utah is the question of the geological age of the quartzite beneath the Carboniferous limestone surrounding the main quartzite series of the Uinta Mountains. It is 

probable that there is a series of Cambrian rocks beneath the limestone 

and above the quartzite as in the Big Cotton wood Canon section of the 

Wasatch Eauge; but it will remain an open question until paleontologic evidence is obtained.

Colorado. Investigation in Colorado should be directed toward discovering fossils in the strata referred to the Upper Cambrian zone, and 

to verifying the exact stratigraphic position of the beds carrying 

Dikelocephalus at Quandary Peak.

Rocky Mountains. In the eastern district of the Eocky Mountain 

Province it is desirable that close study should be made of the various
WAI.COTT.] PROBLEMS FOR INVESTIGATION. 385

sections of the eastern ranges of Colorado, Wyoming, and Montana, 

for the purpose of detecting the presence and character of the fauna as 

a means of correlating the strata with those of the Black Hills and the 

upper Mississippi Valley. On the western side, in southeastern Idaho, 

the Gallatin Kiver section needs special investigation in order to correlate it with the sections of Nevada. Eeference to what is required in 

Utah, Nevada, and Colorado has already been made.

Arizona. It is desirable that larger collections should be made from 

the lower sandstone of the Cambrian section in the Grand Canon area, 

and that the geographic distribution of the Cambrian in western Arizona 

be determined.

Upper Mississippi Valley. Through the work of the Wisconsin and 

Minnesota surveys our knowledge of the Upper Cambrian sandstone is 

unusually complete. It is desirable that more information should be 

obtained in relation to the distribution of the fauna in the section and 

to ascertain whether the Middle Cambrian fauna accompanied the invasion of the sea that deposited the lowest beds of the terrane.

To determine the age of the sandstones on the south shore of Lake 

Superior it is still necessary to obtain paleontologic evidence to enable 

the geologist to state positively that th« sandstones are the geologic 

equivalent of the fossiliferous sandstone of the central area of Wisconsin. It is also desirable to trace the continuation of the recognized 

fossiliferous Upper Cambrian sandstone directly west of Green Bay., 

Wisconsin, with that occurring on the south shore of Lake Superior. 

The definite settlement of these two problems will remove what has long 

been the source of contention among geologists.

Missouri. It is desirable that the exact line of demarcation between 

the Upper Cambrian and Silurian (Ordovician) zones should be determined and more positive paleontologic data be obtained of the relative 

stratigraphic position of'the beds with those of other areas that are 

now referred to the Cambrian.

Texas. The information in relation to the Cambrian area of central 

Texas, in Llano County, is sufficient for most geologic purposes, although 

more detailed information as to the horizontal distribution of the fauna 

and the presence or absence of the Middle Cambrian fauna is desirable. 

The principal question, however, is the investigation of the supposed 

Cambrian in the vicinity of El Paso and the southwestern portion of 

the State.

PROBLEMS AFFECTING OTJR KNOWLEDGE OF THE CAMBRIAN GROUP 

AS A WHOLE OR IN LARGE PARTS.

A glance at the map delineating the distribution of the Cambrian 

strata as shown by outcrops in North America, PI. I, reveals at once 

the fact that we are dealing almost entirely with a marginal or coast 

series of sediments that are largely covered, over great areas, by later

81 35
386 THE CAMBRIAN. JfeuLL.81.

deposits. It is only here and there that a deep-seated disturbance has 

brought up the sediment that accumulated at some distance from the 

shore line. In Vermont and Nevada, especially in the latter, the 

calcareous sediments forming the limestone have been brought to the 

surface. In the great interior area of Wisconsin, Missouri, Texas, and 

the eastern front of the Eocky Mountains and the northern line 

between Canada and New York nothing is known of the deeper water 

deposits, if any such existed.

We know something of the sediments that accumulated along the 

western shore line of the Appalachian protaxis; but what was deposited over the area of which Ohio, Indiana, Kentucky, Tennessee, 

northwestern Alabama, Mississippi, northern Texas, Indian Territory, 

Kansas, and Nebraska forms a part we know nothing.

From the fact that in Texas, Missouri, the Upper Mississippi Valley, 

along the eastern front of the Rocky Mountains, and in New York and 

Canada west of the Adirondacks the deposits are such as would 

accumulate in a shallow sea not far distant from the shore line it has 

been assumed that the Cambrian ocean of this great area was relatively shallow. I think that during Lower and Middle Cambrian times 

the entire interior continental area was above the sea level. These 

opinions are based on the character of the deposits and the absence of 

the sediments of the Lower and Middle Cambrian. The great problem 

in this connection, however, is to determine how far the pre-Cambrian 

continent extended to the south and east and what its relations were 

to the offshore ridges of the eastern and western margins, along which 

we now find deposits of Lower and Middle Cambrian age.

A careful study of the sections in Pennsylvania, Virginia, Tennessee, 

Georgia, and Alabama may throw some light upon the question on 

the southeastern side. Over the remaining portions of the great central area no natural outcrops are known, and there seems to be no way 

of obtaining information except by very deep borings.

The question of the relations of the Middle Cambrian fauna of the 

Atlantic Coast Province to that of the Appalachian and Eocky Mountain Provinces is one that can be settled only by a close and careful 

study of the faunas, based on large collections methodically made 

throughout the entire areas of the three provinces. That the Middle 

Cambrian or Paradoxides fauna of the Atlantic Coast Province is represented by a very different fauna in the Eocky Mountain Province 

there is not, I think, any question. It is also well proved that the 

latter fauna is present to a less extent in the Appalachian Province.

Throughout the Eocky Mountain Province, except in British Columbia, the Olenellus or Lower Cambrian fauna is confined to a very narrow zone, while in Vermont it ranges through 1,000 feet of limestone 

and up into the superjacent shales. In New York it has a range through 

a great thickness of shales, slates, interbedded limestones, and sandstones j and one of the problems requiring investigation is the downward
WALCOTT.I PEOBLEMS FOR INVESTIGATION. 387

extension of this .fauna in the series of shales, slates, and sandstones 

beneath the now known Olenellus horizon of the western Bocky Mountain Province. The lower series of slates and quartzites have been 

tentatively referred to the Algonkian, but it is quite probable that 

they will be found to carry the Olenellus fauna to a considerable depth, 

and a pre-Olenellus fauna may yet be discovered.

The problem of the downward extension of the Cambrian faunas also 

requires investigation in the Appalachian Province, especially in the 

southern portion in Tennessee, Georgia, and Alabama. The basal 

limit of the Cambrian is now drawn at the Olenellus zone, but in the 

absence of any subjacent fauna there still remain the problems of the 

downward extension of the Cambrian fauna and of the existence of a 

pre-Cambriaii fauna that may have lived in the Appalachian seas.

A local question of interest may be here introduced, as it affects a 

considerable area and involves conditions of sedimentation unknown 

elsewhere in the Cambrian. It is the question of the place of derivation and mode of transportation of the bowlders of the limestone conglomerates that carry in the lower zone, the Lower Cambrian, and in the 

upper zone the Upper Cambrian fauna found along the southern shore 

of the St. Lawrence Eiver from Quebec to Gasp6.

One of the problems partially solved, and one that still requires investigation, is the relation of the pre-Cambrian topography to the sediments deposited upon it, to determine the source of sediments and the 

habitat of the faunas.

Along the Atlantic coast the presence of the pre-Cambrian shore line 

with a varied coast topography is clearly distinguishable, and it is evident that the Cambrian strata now occupy the same relative position to 

the pre-Cambrian as the sediments did when they were deposited. The 

same is true of the shore-line deposits along the western margin of the 

Appalachian, pre:Cambrian protaxis, and the sediments about the Adirondack area. Between the Adirondacks and the Green Mountains a 

great thickness of Cambrian rocks appears to have been deposited in a 

deep, relatively narrow sea; but what the conditions were to the westward of the long line of the eastern boundary of the Appalachian Province is one of the questions requiring solution. The same is true of the 

western limits of the sediments now exposed in the great uplifts of 

central Nevada and British Columbia.

The questions arising from the study and comparison of the various 

provinces all require-a more thorough investigation of the sections of 

the western Rocky Mountain, Appalachian and Atlantic Coast Provinces. They bear upon the nomenclature and classification to be adopted 

for the Cambrian group; and not until we have a more thorough knowledge of the sections of northern Yermont, Few York, Tennesse, British 

Columbia, and Nevada can the classification be considered more than a 

provisional pne;
388 THE CAMBRIAN. lnuu.81. 

PROBLEMS OF NOMENCLATURE AND CLASSIFICATION.

The name. It is still a debatable question with a few geologists, 

whether we shall follow the present general usage and use the name 

Cambrian group, with the area of Cambrian in Wales as its type and 

the descriptions of Prof. Adam Sedgwick as the classical description of 

the group, or, in opposition to this, adopt the name Taconic, proposed 

by Dr. Ebenezer Emmons, with the area of Berkshire, Rensselaer, and 

Washington Counties, east of the Hudson River, in New York, as the 

type, and the papers of 1842 and 1844 of Dr. Emraons as the classical 

description of the group.

While recognizing the fact that the name Taconic has certain claims 

upon the sentiment of Americans, I have-stated elsewhere that I think 

the interests of geology are best served by adopting the term Cambrian, 

as has been done by the great majority of geologists.

The limit of the group. The delimitation of the upper limit of the 

group by geologists who recognize it as distinct from the super)acent 

Silurian (Ordovician) has varied to the extent of placing the arenaceous 

deposits of the shore line, or the strata referred to the Potsdam sandstone, in the Silurian, or including the superjacent Calciferous formation in the Cambrian. To a large extent this difference of opinion is 

based upon the evidence of the local physical conditions of sedimentation, and not upon the included faunas. If we adopt as the principle of 

classification that the delimitation of the great geological groups must 

rest upon the broad zoological characters of their included faunas and 

not on local stratigraphic breaks between certain series of rocks, or on 

local differences of sedimentation, the line of demarkation between the 

Cambrian and Silurian (Ordovician) is to be drawn where the marked 

characters of the Cambrian fauna give way to those of the Ordovician. 

That this principle is the only sound one upon which to base the delimitation of a group is proved by the fact that there is no other relatively 

constant character upon which to rely in geologic classification. That 

it is often arbitrary is known to all working geologists.

The line of demarcation along the northern and eastern sides of the 

Adirondacks is between the upper beds of the Potsdam sandstone and 

the calcareous layers of the Calciferous formation. On the south side, 

in Saratoga County, it is drawn in a series of limestones, where the 

characteristic Upper Cambrian fauna disappears and the types of the 

Silurian (Ordovician) fauna appear. In western Vermont, 20 miles 

from where the division is made between the Potsdam and Calciferous 

formations, the line is drawn in a series of black argillaceous shales, 

somewhere between a horizon carrying characteristic Upper Cambrian fossils and another horizon some distance above, in which 

characteristic Calciferous fossils are found. In the Southern Appalachian Province, in East Tennessee, the line of demarcation is not at the 

base of the limestone series, but at a point in the lower portion of it,
WALCOTT.J PROBLEMS FOR INVESTIGATION. 389

where the characteristic Upper Cambrian fauna disappears and the 

Silurian (Ordovician) fauna begins to predominate. This same principle of demarcation is followed in the limestone series of central 

Nevada, while over the interior continental area it is largely drawn at 

the summit of the sandstone carrying the Upper Cambrian fauna and 

at the base of the limestone in which the Calciferous fauna occurs. In 

some instances, however, the Upper Cambrian fauna extends up into 

the Calciferous beds, and in such the line of demarcation occurs in the 

Calciferous zone.

It is not always possibl e to delineate on the map such close lines of 

demarcation within a formation, and for the sake of convenience it 

may be well to map the formation by their lithologic characteristics and 

describe in the text the line of delimitation between the groups. When, 

however, the line between two groups occurs in a limestone, as in the 

Pogonip limestone of the Eureka district, Nevada, and there is sufficient paleontologic evidence to demonstrate it, the line should be drawn 

on the map at the point indicated by the faunas.

The problems in connection with the delimitation of the summit of 

the Cambrian group remain to be studied in nearly all portions of the 

various provinces. In some they are fairly well settled, but there still 

remains much to be done in the way of collecting the faunas and studying their vertical distribution in the strata.

Is the basal line of the Cambrian group at the lowest limit at which 

the Olenellus fauna is found ? Where this lowest limit occurs at the 

base of a conformable series resting unconformably upon pre-Cambriau 

rocks there is no difficulty in answering the question. But where it 

occurs in the midst of a conformable series and there remain thousands 

of feet of sediments beneath the Olenellus zone, as in Nevada and Utah, 

it still remains a problem for consideration. On the general proposition that I would not refer to the Cambrian any rocks beneath the 

Olenellus zone, the subjacent strata of the western Bocky Mountain 

area were referred to the Algoukian in the paper reviewing the Lower 

Cambrian or Olenellus fauna published in the tenth annual report of 

the U. S. Geological Survey. I think, however, it is a question for discussion and research, as the Olenellus fauna has a great vertical and 

time range in the Northern Appalachian' Province, while in the Southern Kocky Mountain Province it is limited to the very narrow band of 

strata at the summit of the siliceous series of slates and quartzites.

That the question of how the Cambrian shall be divided in America 

still requires investigation, with special relation to the classification 

to be applied in the various provinces, is well known. The three primary divisions of the Cambrian (Lower, Middle, and Upper) are readily 

recognized in Newfoundland, and that one or the other of these divisions can be distinctly recognized in the other provinces has been 

proved.

In the Interior Continental Province only the Upper Cambrian, with
390 THE CAMBRIAN. [BULL.81.

its distinct sedimentation and fauna, is known, and no other appears to 

have been deposited. In the Appalachian Province, in Vermont, the 

Lower Cambrian is readily separated by organic remains and sedimentation ; but with our present knowledge it is impossible clearly to distinguish between the Middle and Upper Cambrian. The same is true 

throughout the Appalachian region, except in the Adirondack subprovince, where the Upper Cambrian is well developed. In the Eocky 

Mountain Province the Lower Cambrian is distinctly developed, but the 

Middle and Upper merge more or less into each other. The problems 

in this connection requiring investigation are clearer delimitations of 

the Middle and Upper Cambrian in the Appalachian and Eocky Mountain Provinces* both by the careful study and comparison of the sections and the collecting and differentiation of the faunas.

It is not anticipated that uniformity will be found to exist in each of 

the primary subdivisions; the sedimentation of the various provinces 

is too unlike. The three divisions will have to be used, if at all, in a 

somewhat arbitrary manner in some of the areas, just as the greater 

division of the Cambrian is arbitrarily separated from the Silurian 

(Ordovician) where no physical line of division is apparent. We recognize the Cambrian group as a convenient means of classification, but 

its subdivisions must be controlled by the needs of the local geologist 

and not used unless distinctly recognized.
CHAPTER VI.

THE CRITERIA AND PRINCIPLES USED BY AUTHORS IN THE CORRELATION OF THE VARIOUS PARTS COMPOSING THE GROUP, 

WITH OBSERVATIONS ON SOME METHODS OF CORRELATION.

HISTORICAL NOTES.

The earlier American geologists took their first views of classification 

and principles of correlation mainly from European authors. Among 

the latter Dr. John Woodward said early in the eighteenth century in 

his " Natural History of the Earth ":

That the stone and other terrestrial matter in France, Flanders, Holland, Spain, 

Italy, Germany, Russia, and Sweden were distinguished in strata or layers as it is in 

England; that these strata were divided by parallel layers; that there were inclosed 

in the stone and all the other denser kinds of terrestrial matter great numbers of the 

shells and other productions of the sea in the same manner as in that of this island. 1

This is one of the earliest correlations of stratified and fossiliferous 

rocks. It is crude and indefinite as compared with modern correlation, 

but the general method of comparing stratified fossiliferous rocks because they are stratified and fossiliferous was inaugurated.

Dr. Abraham Werner, in Germany, gave systematic form to descriptive geology in the latter part of the eighteenth century; while about 

the same time Prof. William Smith, in England, applied organic remains in geologic investigation, and correlated formations in various 

parts of the British islands by their contained fossils. A little later 

Baron George Cuvier was establishing in France the great principles 

of the succession of varying organic remains in the strata and their 

differentiation from living forms.

AMERICA.

Maclure. In America Mr. William Maclure was among the first to 

take advantage of the principles of classification enunciated by Dr. 

Werner, and we find the correlations made by him in preparing his 

geological maps were based entirely upon lithologic and stratigraphic 

evidence. This is stated in the first paragraph of the introduction to 

his paper: 2

Necessity dictates the adoption of some system. So far as respects the classification and'arrangement of names the Wernerian appears to bo the most suitable, first, 

because it is the most perfect and extensive in its general outlines, and secondly,

 An Essay towards a Natural History of the Earth and Terrestrial Bodies. London, 3d ed., 1723. 

z Observation s on the Geology of the United States explanatory of a geological map. Am. Phil. Soo. 

Traus., vol. 6,1800, pp. 411,412.

391
392 THE CAMBRIAN. IBULL.SL

the nature and relative situation of the minerals in the United States, while tbey are 

certainly the most extensive of any field yet examined, may perhaps be found to be 

the most correct elucidation of the general exactitude of that theory as respects the 

relative position of the different series of rocks.

On the map four great classes of rocks are recognized: Class I, Primitive rocks; II, Transition rocks; III, Secondary rocks; IV, Alluvial 

rocks. The presence of rock salt in the southern Appalachian is recognized by a separate color.

In the text 1 the Primitive rocks are divided into fourteen varieties, 

the Transition into five varieties, the Secondary into twelve, and the 

Alluvial into seven. In traversing the country Mr. Maclure noticed the 

presence of any one of these rocks at their various outcrops, and 

thus correlated the geological formations that presented similar 

characters. In the second edition of his work 2 two methods of examining and correlating the rocks are given:

The first, the accurate investigation of a small portion of the surface, describing exactly the different rocks with their immense variety 

of arrangement and position of their component parts, detailing the 

changes, accidental or natural, constantly occurring in their relative 

situation, and endeavoring to reduce the whole to some regular series 

of arrangement. This method necessitates the reunion of a great number of those portions before any correct general idea can be formed.

The second, beginning with the great outline, traces the limits which 

divide the principal classes of rocks and their relative situation and 

extent. Mr. Maclure favors the second, stating:

In tracing the outlines of the different formations in most countries there is less 

confusion and embarrassing description necessary; the limits once ascertained, a few 

pages define the boundaries and explain the relative situations to the comprehension 

of every reader.3

Eaton. After Mr. Maclure, Prof. Amos Eaton was the most important factor in the shaping of the methods of geologic work in America. 

By his various publications and his influence as a teacher he outlined 

the methods and formulated the general principles upon which geologic 

investigation was carried forward for nearly two decades. The correlations made in his earlier works were based entirely upon the lithologic 

characters of the rocks. Believing in the Mosaic cosmogony, he explained the phenomena he observed in the structural relations of the 

rocks by the giving way of the foundation of the Old World prior to 

the flood. He says: 4

While this tremendous crash of nature was going on, scales of various thicknesses 

from the various strata were shot up, detached, and broken, which gave formation to 

our surrounding hills, the ragged cliffs of the Catskill, and the bleak brow of the

>0p.cit.,p.412.

^Observations on the Geology of the United States; with remarks on the probable effects that may 

be produced by the decomposition of the different classes of rocks on the nature and fertility of soils. 

Am. Phil. Soc. Trans., vol. 1, new ser., 1817, pp. 1-91.

S 0p. cit.,p.9.

4 An index to the Geology of the Northern States, with a transverse section from Catskill Mountain 

to the Atlantic. Leicester, 1818, pp. 48,49.
WALCOTT.] CORRELATION. 393

Andes. Some were formed at the bottom of the sea by volcanic fires, others have 

arisen from various causes since the great daep retired.

During the deluged state of the earth many species of animals were probably destroyed. For we continually find the petrified remains of species of animals now 

totally extinct.

From the latter observation it is quite evident that at that time lie 

did not consider fossils to be of any value in the correlation of the 

rocks. In the next edition of the Index 1 his theories of the origin and 

first condition of the surface and position of the rocks are omitted, and 

a more thorough description is given of the various rock masses, the 

classification of which was lithologic and based on the views of Dr. 

Werner. His more extensive work of 18242 shows that the correlations made between the rocks of the Hudson and those west of the 

Hudson, along the line of the Erie Canal, were based mainly upon their 

lithologic characters. For instance, the Calciferous stindrock of the 

Mohawk Yalley, in the vicinity of Little Falls, New York, was traced 

westward in the vicinity of TJtica and eastward down the Mohawk 

Valley to the vicinity of Schenectady, and then correlated with a Calciferous sandrock on the east side of the Hudson. This correlation 

was made upon the lithologic character and the stratigraphic succession of the rock masses. Its defective character is shown by the fact 

that the Calciferous sandrock east of the Hudson is of Lower Cambrian age and that west of the Hudson is of Silurian (Ordovician) age.

Classification and correlation on the basis of lithologic character and 

stratigraphic succession was continued by Prof. Eaton in his work of 

1828 3 and again in his text-book of 1S30.4 On the map accompanying the latter all the quartzose formations are colored yellow, all the 

calcareous formations blue, the variegated sandstones red, and the subordinate rocks green. By this the primitive limestones of the Adirondacks (Algonkian), the Lower Cambrian limestones of Washington 

County, the Calciferous-Chazy-Trenton limestones of the central portions of the State, and the Lower Devonian limestones of the Upper 

Helderberg are all placed under one color.

In 1832 5 he introduced a new heading into his Text Book, as follows: 

" Organized remains as auxiliaries in the determination of rock strata." 

Under this he says:

The remains of similar species of animals and plants are found embraced in similar 

series of rocks ; and these occurrences are so uniform that rocky and earthy strata 

may be determined by them.6

'An Index to the Geology of the Northern States, 2d eel., 1820, pp. 286.

2A geological and agricultural survey of the district adjoining the Erie Canal, 1824, pp.163.

3 Geological nomenclature, exhibited in a synopsis of North American rocks and detritus. Am. Jour. 

Sci., vol. 14,1828, oppo. p. 144, pp. 145-149, 359-368.

4 Geological text-book, prepared for popular lectures on North American geology; with applications 

to agriculture and the arts. Albany, 1830, pp. 64.

6 Geological text-book for aiding the study of North American Geology; being a systematic arrangement of facts, collected by the author and his pupils, under the patronage of the lion. Stuphou 

Van Rensselaer. 2d ed. Albany, 1832.

G 0p. cit., p. 25.
394 THE CAMBRIAN. [BULL.SI.

In connection with, the discussion of the presence of organic remains 

in tbe rocks the following passage5 occurs:

The geological deposits of this country (and probably those of the eastern continent) exhibit grounds for conjecture if not absolute demonstration that the surface 

of the earth has undergone five general modifications, which no animals survived. 

Four of these modifications were followed by as many new creations of animals. Also 

that two new creations of animals succeeded the final depositions of all regular strata. 

In the whole, there appears to have been five creations of animals at least (perhaps 

ten) since the primitive m ass of the earth was formed, and a long interval succeeded 

each creation. 1

It is also said that the " remains or impressions of plants are limited 

to coal and coal formations whose relative position is indicated by their 

rocky associates; the determination of rocks by their animal relics 

serves as an index to the position of coal measures or beds. In this 

concise selection of the most essential relics animals alone will be 

noted which have no backbone nor brains " [invertebrates].2

Under the title of "Geological Equivalents" Prof. Eaton mentions 

that relative position and mineral constituents were deemed sufficient 

by Werner for determining geological equivalents. As relative position 

is the basis of the science, all other circumstances have always been 

received as auxiliaries only so far as classification is concerned.3 He 

reasoned that as rocks can be traced more or less continuously throughout New York and Pennsylvania the data used by Werner are of 

value; but 

From a consideration of the cases here referred to, intrinsic characters more definite 

than any left us by Werner seem to be essential to the progress of the science. The 

enumeration of mineral constituents of rocks can never be satisfactorily applied. 

Unorganized matter presents but few characteristics. Naturalists find it a more difficult task to describe by external characters about two hundred and seventy species 

of minerals than fifty thousand species of plants and a still larger number of animals.

It is a subject of high congratulation to students in geology of our day that the 

illustrious Cuvier, aided by the Brongniarts and their coadjutors, have extended the 

science of organic nature to the science of geology. We are no longer limited to the 

enumeration of mineral constituents. We find the same organized remains associated 

with equivalent strata in every part of the earth, though they often extend into 

several adjoining strata, which are probably contemporaneous or nearly so.4

He then proceeds to classify the strata as known to geologists of both 

continents by means of some of their organic associations in North 

America.5

A few months later he published a paper on " Four cardinal points 

in stratigraphical geology established by organic remains," saying:

If the identity of the Granular, the Metalliferous, and the Oolitic calcareous rocks, 

and of the Tertiary marls are established on both continents all intervening strata 

may be ascertained with great facility. I think that a reference to the following 

facts will be sufficient to establish their equivalent characters at least. 6

1 Op. cit., p. 48. s Op. cit, pp. 136-138.

2 Op cit., p. 25. 6 Four cardinal points in stratigraphical geology

3 Geological equivalents. Am. Jour. Sci., vol.21, established by organic remains. Am. Jour, 

1832, pp. 132-138. Sci., vol. 21,1832, p. 199. 

"Op. cit., p. 134.
TTALCOTT.] CORRELATION. 395

The first cardinal point is the Granular limerock " the only limerock which is always destitute of organic remains." The second cardinal point is the Metalliferous, Mountain or Carboniferous limerock. 

Under this heading he correlates the limestone at Trenton Falls and 

most of the limestones of New York. The third cardinal point embraces the Oolitic series or Calcareous rocks, and the fourth the Tertiary marls. These correlations of Eaton were crude, but when refined by the geologists of the New York State survey the first three 

formed the basis for the correlation of the lower and middle Paleozoic 

rocks of the continent.

Bigsly. The earlier work of .Dr. J. J. Bigsby was apparently unknown to Eaton. The former used organic remains in a very general 

manner to correlate the strata of England and America, but also depended upon the lithologic characters and stratigraphic succession. 

In an article entitled "A list of minerals and organic remains occurring in the Canadas " he remarks upon the extent and relations of 

the limestones and sandstones of the eastern and western parts of 

Canada. Of the limestones he says:

Their relation to the bubjacent rocks and uniform similarity in structure and contents, mineral as well as organic, seem to indicate that the beds of limestone, extending with few or no interruptions from Cape Tourment, below Quebec, to near the 

Falls of St. Mary, are the effects of a contemporaneous deposition; and further, 

that they are the representatives of the Mountain or Carboniferous limestone of England.

I make these statements with extreme diffidence, being in some degree aware of 

the difficulties of the discussion, of the existence of contradictory facts, few but 

weighty, and of the defective state of our information respecting the vast calcareous 

formations of North America. 1

The reference to the secondary limestone of the St. Lawrence and 

the lake region is as follows :

The limestone now described abuts on one of the older rocks directly, or with the 

interposition of another horizontal stratum, and by far the most commonly on 

gneiss, which I have strong grounds for believing to be of the same age and general 

characters throughout the whole of the districts under consideration. It is incumbent directly on gneiss in the bed of the river St. Anne, near its upper fulls, 

in the seigniory of St. Feriole, Lower Canada; at Montmorenci, not far from "the 

natural steps," but only seen in time of low water; at and near Point Henry, close 

to Kingston, Upper Canada ; and in many places on the north coast of Lake Huron. 

In the last-named locality it rests directly, in several instances, on a beautiful snowwhite transition quartz, which occupies the main shore in steep hills, 400 and 500 

feet high, from near the French River to the River Le Serpent (70-80 miles). The 

immediately subjacent rock at La Cloche and on the isles north of theManitoulines, 

in the same lake, is sometimes a highly inclined greenstone. Near Montreal it 

overlies directly crystalline trap, containing augite, zeolite, mica, feldspar, etc.

But ordinarily a sandstone, gray wacke, or a conglomerate of quartzose or calcareous 

materials is interposed; also in horizontal layers. It is to be remarked (on passant) 

that much the greater part of the graywacke of Lower Canada does not belong to 

this deposition, but is conformable to the mica-slate, gneiss, etc., ranging along the 

north shore of the St. Lawrence, between Quebec and the river Saguenay. * * *

1 A list of mineral and organic remains occurring in tho Canadas. Am. Jour. Sci., vol. 8, 1824,' pp. 

70,77.
396 THE CAMBEIAN. [BULL.81.

The sandstone, which is beneath the limestone from near Kingston, Upper Canada, 

to St. Anne's, 26 miles northwest of Montreal (174 miles), is white, but with ferruginous spots aud clouds, hard, fine grained, without cement, arid contains thick 

layers of large and small nodules of crystalline quartz, disposed in horizoual lines. 

It forms clifl's an hundred feet high in the Lake of the Thousand Islands, which rest 

on the very small-grained gneiss (often a granite) which abounds so in the north and 

northeast and passes largely and frequently into primitive white quartz rock, thus 

disclosing a possible source of the sandstone and quartz nodules. Where clay is the 

cement an argillaceous sandstone or gray wacke is furnished. The former of these I 

have never seen in contact with the inclined rocks. It occurs very distinctly in the 

chasm of the Niagara, the lower strata of which (and particularly those on which 

Queenston stands) are almost ferruginous clay. The nearest primitive is on the north 

shore of Lake Sinicoe, 90 miles off. From the nature of the organic remains andother 

contents of the limestones covering this sandstone, I am inclined to believe the latter 

to be the old red, which is. often thus intermixed with argillaceous matters. At Dunkirk, on the south side of Lake Erie, Mr. Hulbert has bored through these rocks to the 

depth of C82 feet (117 feet below the surface of the Atlantic) and without meeting with 

salt. The above observations apply to the fine sections in the bed of the Genesee 

River; but I have not sufficiently examined the fossils in the limestone of that locality. 

Its sandstone has large but indistinct casts of what I suppose to be encrinites, but 

which, may be vegetable, but in either case resembling the Old Red sandstone. It 

may be added that it is on the same level with and not very far from the sandstone 

of the vicinity of Kingston; but similarity in level taken by itself is not an unerring 

test of similarity in age. In one part of a district or lake granite, gneiss, etc., may 

attain a given elevation and be there covered with graywacke only; while in another and not very distant place these rocks may not rise to within some thousand 

feet of that height, and be buried under all the succeeding strata up to the Crag 

above the London clay. 1

A conglomerate wholly calcareous occurs in situ near the foot of the Long Sault 

of the river Ottawa, and at the Coteau du lac, 3 miles below Lake St. Francis, composed of angular and rolled masses, sometimes very large, of fine granular limestone 

light brown and blue, imbedded in a dark brown paste. A similar rock occurs with 

the limestone about Poughkeepsie, in the State of New York, and at Aubigny, opposite Quebec, interleaved with clay slate and graywacke, highly inclined, and having 

a southwest direction. 2

The elements of correlation suggested in the preceding quotations 

include lithologic resemblance, similarity of level in a given area, stratigraphic succession, and the presence of organic remains.

At a later date Dr. Bigsby noticed in the conglomerates on the south 

side of the St. Lawrence, opposite Quebec, the presence of trilobites, 

encrinites, corrallites, and other fossils, and, on this account, considers 

the formation the equivalent of the Carboniferous limestone of the 

English geologists. 3

James. One of the earliest extended correlations in America is that 

of Dr. Edwin James.4 In his remarks on the sandstone of the western 

part of the valley of the Mississippi he first describes in detail the red 

sandstone.5 He states that this rock is the lowest of the horizontal or

1 Op. cit., pp. 78-80. 

"Op. cit., p. 81.

s On the geology of Quebec and vicinity. Proc. Geol. Soc. London, vol. 1, 1827, p. 38. 

"llemarks on the sandstone and Flootz trap formations of the western part of the valley of the 

Mississippi. Am. Phil. Soc. Traus., vol. 2, new ser., 1821, pp. 191-215. 

0 Op. cit., p. 204.
WAI.COIT.] CORRELATION. 397

secondary rocks met with and is very abundant in all that part of the 

plain immediately adjacent to the Eocky Mountains which he had examined. A similar rock is met with in the eastern part of the State of 

New York. Specimens from many parts of the strata on the Canadian 

Eiver are entirely similar to those quarried in New Jersey and used 

in great quantities in the cities of New York, Albany, etc., for building.

u Whether this sandstone is in all respects similar to the ' Old Eed 

sandstone' of Werner, which makes so conspicuous a figure in the 

systems of certain geologists, we are not able to say. It, however, 

certainly occupies a place similar to the one which has been assigned 

to that rock." In a foot-note referring to this statement it is said 

that 

This red sandstone is first found on the waters of the lakes on the strait between 

Lake Huron and Lake Superior, and forms the fall called the Sault de Sto. Maria.2

It also occurs iu the Catskill Mountains and in the Salt District in the western part 

of the State of New York, having a similar relation to the secondary rocks in that 

quarter. * * * The red sandrock now under consideration appears at one place 

with every character requisite to place it among the rocks of transition, at another 

it is manifestly secondary; yet its continuity may be traced through minute shades 

of gradation or by a sudden transition from one of these points to the other.2

A review of the preceding remarks indicates that Dr. James supposed the Jura-Trias sandstone of the eastern foothills of the Eocky 

Mountains, the red sandstone of the Lake Superior region (Algonkiau), 

the eastern New York sandstone (Upper Cambrian), and the New Jersey 

Triassic sandstone were of the same relative geologic age as shown by 

their lithologic characters and supposed stratigraphic position.

Balcewell. The publication of the American edition of Mr. Eobert 

BakewelPs Geology in 1829 was an important contribution to American 

geologic literature. It presents an account of the geological distribution of organic remains as then understood and the general principles 

of geology as known to English geologists.

In regard to correlation by fossils Mr. Bakewell says:

With respect to fossil conchology he is inclined to believe that the attempt to identify the strata of distant countries by the isolated occurrence of any particular species 

of shell has been carried further than a sound induction from facts or analogy would 

warrant. His opinion on this subject, given in the second edition of this work, he 

will here insert: "It may be doubted whether the occurrence of similar organic 

remains is sufficient to identify strata in distant parts of the globe; for could we 

admit that strata are.universal formations and extended from the frozen to the torrid zone, it seems more than probable that the animals that lived on any one particular stratum would be of very different species in different latitudes." * » »

In strata belonging to one forir.ation and in adjacent districts, the existence of certain shells, whether we regard them as distinct species or as varieties, may be of use 

in identifying any particular bed; and in distant countries where we find the same 

remarkable species of shell associated with any other remarkable species in considerable numbers it may serve to identify a particular rock formation, where the mineral character of the rock may be very different from that in which the observer has

1 Op. cit., p. 205. 2 Op. cit., p. 208,
398 ' THE CAMBKIAN. IBULL.SI.

been accustomed to meet with them. The occurrence of a considerable number of 

grypheae, the Giyphea arcuata in a bed of blue clay in the mountains around the 

Lake of Annecy in Savoy, served the author as a key to discover to what formation 

the calcareous strata belonged, when their mineral characters would have indicated 

a more ancient series. 1

De la Beclie. In 1832 an edition of the Geological Manual2 of De la 

Beche was published in Philadelphia. In the section upon the classification of rocks we find the following remarks upon classifiation by 

organic remains:

To propose in the present state of geological science any classification of rocks 

which should pretend to more than temporary utility would be to assume a more 

intimate acquaintance with the earth's crust than we possess. Our knowledge of 

this structure is far from- extensive, and principally confined to certain portions of 

Europe. Still, however, a mass of information has gradually been collected, particularly as respects this quarter of the world, tending to certain general and important 

conclusions, among which the principal are, that rocks may be divided into two 

great classes, the stratified and the unstratified; that of the former some contain 

organic remains and others do not; and that the nonfossiliferous stratified rocks, 

as a mass, occupy an inferior place to the fossiliferous 3 strata, also taken as a mass. 

The next important conclusion is, that among the stratified fossiliferous rocks there 

is a certain order of superposition, apparently marked by peculiar general accumulations of organic remains, though the uiineralogical character varies materially. 

It has even been supposed that in the divisions termed formations there are found 

certain species of shells, etc., characteristic of each. Of this supposition extended 

observation can alone prove the truth; but it must not be supposed, as some now 

do, that in any accumulation of ten or twenty beds, characterized by the presence 

of distinct fossils in a given district, the organic remains will be found equally characteristic of the same part of the series at remote distances.

To suppose that all the formations into which it has been thought advisable to 

divide European rocks can be detected by the same organic remains in various distant points of the globe is to assume that the vegetables and animals distributed 

over the surface of the world were always the same at the same time, and that they 

were all destroyed at the same moment, to be replaced by a new creation, differing 

specifically, if not generically, from that which immediately preceded it. From this 

theory it would also be inferred that the whole surface of the world possessed an uniform temperature at the same given epoch.

It has been considered, but has not yet been sufficiently proved, that the lowest 

rocks in which organic remains are found entombed show a general uniformity in 

their organic contents at points on the surface considerably distant from each other, 

and that this general uniformity gradually disappeared, until animal and vegetable 

life became as different in different latitudes, and even under various meridians, as 

it now is. How far this opinion may or may not be correct can only be seen when 

geological facts shall have been sufficiently multiplied ; but it is one which demands 

considerable attention, as the classification of fossiliferous rocks greatly depends upon 

it. Should it eventually be found to a certain degree correct it would not be at variance with the theory of a central heat, which having diminished permitted solar 

heat and light gradually to acquire an influence on the earth's surface.4

Numerous other European works soon came into the hands of the 

American geologists, among them the earlier editions of Bakewell,

1 Introduction to Geology, Bobt. Bakewell, 1st American edition, New Haven, 1829, pp. 32,33.

2 Geological Manual, Philadelphia, 1832.

1 The term fotttttferout is here confined to organic remains,

*0p.cit., pp.33,34.
WALCOTT.] COERELATION. 399

Lyell, Man tell, and various French and German authors. Their influence 

is shown by the rapid development of stratigraphic geology based upon 

the principles established in Europe. Of the means of correlation available to Prof. Amos Eaton in his earlier work he says, in 1839:

Eaton. When I commenced my geological surveys the application of organized 

remains for demonstrating strata was not studied in America. I had become acquainted with no method for determining the character of such strata but that of 

tracing them separately through a vast extent of country and then comparing their 

general characters. For this purpose I traveled some thousand miles at my own expense and with the liberal aid of students of Williams College, with Prof. Dewey at 

their head, where I was employed more than a score of years since by the authorities 

of the college to introduce the natural sciences. Afterwards I traveled more than 

17,000 miles on geologizing tours at the expense of the Hon. Stephen Van Rensslaor, 

and I was always aided by several assistants and competent students. Had the application of paleontology been then as well understood as it now is I could have 

settled the characters of most rocks as well in my closet by the aid of specimens. 

But it is a true remark in your last journal that strata must have been first settled 

according to the method to which I was compelled by ignorance to submit, before 

the service of organized remains could be successfully employed. In this country no 

material progress had then been made in the study of organized relics, and even now 

we have very few good paleontologists. 1

NEW YOBK SURVEY.

The geologists of the New York State survey systematized the work 

of the geologists who preceded them and established a standard section 

of the lower and middle Paleozoic formations of New York. On this 

account it is desirable to examine the principles of correlation mentioned by Messrs. Conrad, Hall, and Emmons and to notice the extension 

of the nomenclature of the formations of the New York section to various portions of the continent.

Conrad. As paleontologist of the survey Mr. T. A. Conrad made the 

following comments upon the use of fossils in the correlation of strata : 2

There is a strange misunderstanding of the method of applying organic remains 

in the division of series of strata into formations and the identification of widely 

separated rocks by the zoological characters of each. In the January number of the 

New York Review the opinion is advanced that the "Calymene bluiuenbachii ought 

to be carefully sought for in the rocks which are said to correspond to the Dudley 

period. Unless it is found, or some other consideration is introduced, can it be believed that fossils are a satisfactory evidence of the age and place of rocks ? " The 

line of demarcation between rocks of different ago has never yet been drawn with 

any accuracy by the aid of paleontology, except by the consideration of groups of 

species, one or even a few species having no weight whatever in the determination. 

Thus the shell termed Terebratula Schlotheimii dates its existence with the Trenton 

limestone, and reappears in three of the latter formations of the Silurian system. Orthis testudinaria, Dalm., is peculiarly characteristic of the Trenton limestone, by its 

almost invariable presence and extreme abundance, and yet it is also found in the 

limestone of the Helderberg, a formation of a far more recent origin. But, although 

a few species may have been continued through a succession of geological eras, the

1 Chorty limerock or Corniferous limerook, proposed as the line of reference for State geologists 

of Now York and Pennsylvania. Am. Jour. Sci., vol. 36,1839, p. 67.

'Second annual report of the paleontologies! department of the survey. Third annual report of t)ie 

ecological survey of New York, 1839, p. 58. Albany.
400 THE CAMBRIAN. [BULL. 81.

groups are widely distinct, and their value in determining the comparative age and 

identity of formations can never again be called in question by a geologist who deservos the name.

Attention is called to the fact that no observer has yet drawn the 

line of distinction between the Trenton and the newer limestone superimposed upon it in Ohio and Kentucky, because the similarity in mineral character and color is so perfect, and both formations thin out into 

mere seams and layers. It is also stated that the catalogues of organic 

remains of the Silurian system hitherto published in Europe are calculated only to mislead and confound the geological inquirer, as they 

are far too vague.1

In 1840 Mr. Conrad instituted a series of comparisons of formations 

of the New York section with those of England, based upon the fossils 

contained in their respectative formations. He compares the Caradoc 

sandstone with the limestone of Trenton Falls, and the Wenlock shale 

with the Rochester shale, and the Wenlock limestone with a limestone 

developed in the Helderberg Mountains.2

In the fifth annual report on the paleontology of New York we find 

the following remarks applied to correlation of the rocks of the State : 3

The horizontally and undisturbed condition of the strata have enabled us to trace 

their sequence or order of superposition with comparative ease and greater accuracy 

than can always be obtained in regions where the formations have been much 

inclined or distorted. These divisions or series are usually composed of various 

layers, as compact limestone associated with friable shale, sandstone alternating with 

argillaceous shale, etc., and these modifications of their mineral constituents are 

generally accompanied by some variation of the organic contents; new species have 

been introduced, or more ancient ones have disappeared. But it is only at the junction of two formations that each group of organic remains is not perfectly distinct 

and characteristic, a mixture of species sometimes occurring which proves a gradual 

transition from one era to another, and gives rise to some uncertainty where the 

exact line of demarcation should be drawn. This fact opposes the idea sometimes 

indulged by speculative geologists, that sudden convulsions of the earth's surface 

have been the cause of exterminating forms of life, and the introduction of others to 

supply their place. The change seems rather due to alteration of temperature in the 

water, whatever new physical conditions of the earth resulted at the same time. 

Such phenomena, however, do not interfere with the general distinctive characters 

of the stratigraphical divisions adopted in this work. It is now, I believe, an undisputed point in geology that certain groups of organic remains belong exclusively to 

certain formations, and that these strata, in a general way, may be known and compared by the same groups of genera, if not species, in every region of the earth. It 

is also established, that whilst some genera and many species are restricted to a single formation, others have originated at an early period and continued to exist 

throughout a large portion of the time occupied in the deposition of a system or series 

of formations. * * *

The color and even mineral character of a formation usually varies greatly over an 

extended region, but it may be recognized by its fossil contents; for example, the 

black slate of the Mohawk, characterized by a peculiar trilobite, Triarthrus, which

1 Op. cit., p. 59.

1 On the SUurian System, with a table of the strata and characteristic fossils. Am. Jonr. Sci., vol. 38 

1840 pp. 87-91.

3 Fifth annual report on the paleontology of New York, .Fifth Annual Report of the Geological 

Survey of New York, 1841, pp. 25-27. Albany, ....
WALKOTT. } COERELATJON. 401

lias never been known to occur in any other geological position, is represented by a 

drab-colored shale iu the vicinity of Cincinnati, Ohio. There also the equivalent or 

continuation of the black limestone of Trenton Falls is of a gray or pale hue. and 

could be known as the same rock only by its organic reliquiae. The Caradoc sandstone series of Wales is represented in New York by limestone and slate in proportion 

equal to the arenaceous strata.

Hall. The desirability of naming formations from typical exposures 

to serve as standards of comparison for the purpose of correlation was 

enunciated by Prof. James Hall very clearly in 1839, as follows:

Everyone who has studied rocks even partially is aware of the insufficiency of 

mineral or lithological characters for giving nomenclature, and the many errors into 

which he may be led, whether in his own researches or by the mistakes of others. So 

likewise in the present state of our knowledge we are unable in all cases to give 

names from fossil characters ; for, though without doubt every group embraces its 

peculiar fossils, yet in all localities these may not be so marked as to excite attention, 

and in some may possibly be absent. It thus becomes a desideratum to distinguish 

rocks by names which can not be traduced, and which, when the attendant circumstances are fully understood, will never prove fallacious. The basis of this nomenclature is derived from localities, and the rock or group will receive its name from 

the place where it is best developed. 1

He then proceeds to name the "Rochester shale" from Eochester, 

New York, and the Lockport limestone from Lockport, New York.

In 1843, after stating the general results of an examination of a section southwest from Cleveland to the Mississippi River, he wrote: 2

From the facts here stated the conclusion seems unavoidable, that the character of 

fossils is, or may be, as variable as lithological characters j in fact, that the species 

depend in some degree upon the nature of the material among which they lived. 

Fossil characters therefore become of parallel importance to the lithological; and, 

in order to arrive at just conclusions, both must be studied in connection, and localities of proximity examined. In the case of the Hudson River group of shales and 

sandstones, in passing from New York to Ohio, the lithological character is almost 

entirely changed; and at the same time also the most prominent and abundant fossils 

are unlike those of the group in New York. More careful examination, however, reveals the fossils which characterize this group at the East, and also at the same time 

some obscurely similar lithological characters. Similar lithological changes, accompanied by like changes in fossils, occur in more limited districts within the State of 

New York.

The most marked and important changes, however, appear to be in the higher rocks 

of the New York system. The Hamilton group and Marcollus shale, which in New 

York have a thickness of 1,000 feet, have diminished to 100 where last examined; and 

from being the group most prolific in fossils, as it is in Now York, it has become entirely barren of them. The rocks forming the Portage and Chemung groups, which 

in their greatest development in New York are scarcely less than 3,000 feet in thickness, and in Pennsylvania much more, have in Indiana diminished to as many hundred. The upper of these groups, from being extremely fossiliferous, has become 

almost destitute of these characters, so that, at the farthest extreme examined, they 

furnish but an equivocal guide. In these groups lithological character is more persistent than fossils, and it requires a knowledge of the superposition to identify them 

satisfactorily. The greater thickness of these sedimentary deposits, and the greater

1 Third Annual Report of the 4th Geological district of New York. Third Annual Report of tho 

Geological Survey of New York. Albany, 1839. pp. 288,289.

2 Notos explanatory ot a section from Cleveland, Ohio, to the Mississippi River, in a southwest direction ; with remarks upon the identity of the western formations with those of New York. Assoc. 

Am. Gcol. Trails., 1843, pp. 289-291.

Bull. 81 26
402 THE CAMBRIAN. [BULL. 81.

development of fossils occurring at the same point, proves the organic forms to have 

flourished in a littoral position; and beyond these points, where the thinning of the 

strata indicates a greater distance from the shore the fossils diminish, and at the more 

distant and deeper points are not found at all. There is no evidence of denudation 

in these instances, and if there had been the parts left would have retained the same 

fossils, had it ever contained them, as they do farther east.

Throughout that part of the ancient ocean now occupied by Ohio, Indiana, Michigan, Illinois, and even to the west of the Mississippi, there appears to have been 

comparatively a small number of living forms existing from the period of the final 

deposition of the Helderberg limestones to the commencement of the Carboniferous 

period; while in New York, during the same period, there were a greater number of 

forms and individuals than in all the preceding periods. Without desiring to diminish the value of fossil characters as means of identifying strata, it must still be 

acknowledged that similar conditions in the bed of the ocean, and apparently similar 

depth of water, are required to give existence or continuation to a uniform fauna; 

and when we pass beyond the points where these conditions existed in the ancient 

ocean, we lose in the same degree the evidences of identity founded upon fossils. 

Some species, it is true, have lived onward through successive depositions, often of 

very different nature; yet, at the same time, these may not have had a very wide, 

geographical range. In the case before us, some species have lived during the deposition of all the rocks from the Hamilton through the Chemung groups, and yet they 

have never extended themselves as far westward as Ohio and Indiana, although the 

nature of the deposits there was as favorable to their existence as in New York.

For the distance of 100 or 200 miles from the shores of the present continents the 

forms may be similar we know not but they are still who can say what changes may 

occur, or whether any exist in the depths 1,000 miles from land ? From the nature of 

sedimentary deposits it can be only the finer parts that ever reach to great distances 

from their origin; and, reasoning thus, the fauna of the deep and distant parts of 

the ocean, if any exist, would be uniform, not being liable to destruction or change 

of condition from the rapid invasion of variable deposits like those near the shore. 

The deposition of a coarse sandstone or conglomerate succeeding to a shaly mass would 

in all probability destroy the greater number of living forms as far as it extended. 

But at the same time, the finer materials produced by the same cause would extend 

far beyond the limits of the coarser, and thus approximating in some degree to the 

lower mass, the fossils might be continued long after they were destroyed at another 

point.

One of the most interesting changes in the products on going westward is the 

great increase of carbonate of lime and the diminution of shaly and sandy matter, 

indicating a deeper ocean or greater distance from land. The source of the calcareous 

deposits is thus shown to have been in that direction, or in the southwest, while the 

sands and clays had their origin in the east, southeast, and northeast, producing a 

turbid condition in the waters of these parts during long intervals, which was unfavorable to the production of calcareous matter and the formation of chemical 

deposits. In New York we are evidently upon the margin of this primeval ocean, as 

indicated in the character of the deposits as well as organic remains; the southwest 

unfolds to us that portion where greater depth and more quiet condition prevailed.

At a later date he said;

I have met with no essay upon the geographical distribution of fossils in the older 

rocks; and the few facts here and there gleaned serve rather to stimulate than to satisfy curiosity. It has been a favorite opinion of many, and frequently advanced, that 

the condition of this ancient ocean was uniform and its depth moderate, and that 

the uniformity of organic products affords proof of the same. Without pretending 

to refute any theories or to establish general conclusions for the whole continent or 

for the whole globe, I shall merely offer a few facts which have fallen under my own 

observation, and this with the hope of calling the attention of other observers to the
WALCOTT. ] COKKELATION. 403

subject and aid in deciding the true cause and amount of variation in paleozoic characters when examined over wide districts. We shall doubtless be led eventually to 

see in all these changes the influences of depths of water, distance from or proximity to 

land, and the influence of the nature of that deposit which formed the bed of the ocean, 

on which the animals lived. Every one of these causes, and perhaps other minor ones, 

have influenced the present character and condition of our older fossiliferous deposits. 

All these circumstances influence the organic productions of our present ocean, whatever may be the climate ; and we have every proof that the same causes operated in 

this ancient sea, where, although depth and temperature may have been more uniform, 

yet these could not have been paramount to all other influences. 1

He then proceeds to correlate the strata of the Mississippi Basin with 

those of the .New York section by means of the contained fossils, and 

where possible the order of stratigraphic succession.

Emmons. In a geological report of the midland counties of North 

Carolina, Dr. E. Emmons, in 1856, speaks of the classification of the 

sediments and says in this connection:

Superposition is, however, the highest proof of. age, the oldest occupying the inferior position.

The bearing which fossils have to any scheme of classification which has been 

proposed can be understood only by a knowledge of the following laws: (1) That 

species or Icinds have had a limited duration ; (2) that there has been a succession of species; 

and (3) that the species of one period, and which have become extinct,, have never lived in 

any future period. The utility of the knowledge of fossils is based on these three laws. 

This knowledge is particularly useful in comparing rocks which are widely separated 

from each other, or in those cases where direct superposition can not bo observed. If, 

for example, certain rocks in Canada furnish a group of fossils similar to those of a 

given series in Tennessee, the inference would be that they belonged to the same 

period and hence occupy the same geological position ; or, if we compare the fossils of the coal formation of England and America it will be found that they are 

almost identical; and it is proved also that the position relatively is the same in 

both countries, though separated from each other 3,000 miles. 2

The extension of the New York section to the south along the line of 

the Appalachian Mountains was principally the work of the Rogers 

Brothers and Prof. Safford.

Rogers. As geologists Messrs. H. D. and W. B. Eogers traced the 

the formations by stratigraphic continuity, lithologic characters, serial 

relation, and the presence of similar fossils as in the Trenton limestone, 

etc. I have not met with a statement of their views of geologic correlation 

except in incidental remarks. In a reply made to Prof. James Hall, 

who had congratulated the Profs. Kogers that they had borne such able 

evidence to the value of organic remains in determining the age of 

rock, Prof. W. B. Eogers said :3

That they had not been understood on this point; they had followed out the intricate structural geology'of Pennsylvania and Virginia, relying chiefly on lithological characters, and had found to their great gratification that they had been working 

in parallel planes to the New York geologists, whose labors among the regular and

1 Nature of the strata and geographical distribution of the organic remains in the older formations of 

the United States. Boston Jour. Nat. Hist., vol. 5, 1845, pp. 2, 3.

2 Geological report of the midland counties of North Carolina. New York and Raleigh, 1850, p. 24.

8 A system of classification and nomenclature of the paleozoic rocks of the United Statep, with an 

account of their distribution, more particularly in the Appalachian Mountain Chain. Am. Jour. Soi., 

ypl. 47, 1844, p. 112.
404 THE CAMBRIAN. [BULL. 81.

horizontal strata of that State, relying on the evidence of fossil remains, h.id brought 

out results in the main quite consistent with the determinations of the Virginia and 

Pennsylvania strata.

In an address before the Association of American Geologists and Naturalists, Prof. Henry D. Kogers, in speaking of the tracks in the sandstone of the Connecticut Yalley, says:

Of the organic remains, through an investigation of which alone we can hope to 

establish the position of these strata in the scale of time, or reach definite conclusions 

respecting the physical conditions under which they were produced, the most instructive are the remarkable bird tracks, brought to light by Prof. Hitchcock, in Connecticut and Massachusetts.

Guided by mere lithological resemblance, Maclure imagined this stratum to be the 

equivalent of the Old Red Sandstone of England. 1

These passages imply that Prof. Henry D. Eogers considered paleontological evidence of the highest value in correlation, although in his 

work in Yirginia he relied largely upon stratigraphic relations and lithology for the correlation of the Virginia with the Pennsylvania formations.

The correlation of the sandstone beneath the Trenton and Maguesian 

limestones of Pennsylvania, by Prof. H. D. Kogers and those that succeeded him, was based upon the stratigraphic position of the sandstone 

and the presence of Scolithus linearis, a fossil believed to be common to 

the Potsdam sandstone of New York and the lower sandstone of Pennsylvania.

The evidence of the identity of the sandstone with that of the Potsdam sandstone of New York, on the stratigraphic succession and position, is as follows:

(1) The formation is beneath a series of limestones, a portion of which 

is identified with the Trenton limestone by the contained fossils.

(2) The sandstone rests unconformably upon the tjrystalline gneisses 

forming the basal rocks of the Paleozoic period of Pennsylvania.

(3) The lithologic characters of the sandstone formation corresponded 

to that of the Potsdam sandstone of New York.

The paleontologic evidence is the presence of the annelid borings 

called Scolithus linearis in the sandstone of New York and Pennsylvania.

When once established this correlation was adopted and used by the 

first survey of Pennsylvania and also the second, but not altogether 

without protest by some of the workers in the latter. Mr. d'lnvilliers 2 

calls attention to this correlation of the Potsdam in the following words:

It would be safer to name this formation the Beading sandstone, but in the descriptions of its outcrops along the Little Lehigh, the Lehigh, -and the Delaware Rivers, 

in Vol. I of this report, it has been called Potsdam sandstone, taking for granted that 

any sand formation underneath the Magnesian limestones of the Great Valley must 

be the same sand formation which in northern New York underlies the Corniferous 

[Calciferous ?], Chazy, and other limestones of the Mohawk Valley.

1 On American geology and present condition of geological research in the United States. Am. 

Jour. Sci., vol. 47,1844, p. 248.

*Tho geolozy of the South Mountain Belt of Berks County. Second Geol. Surv. of Penn., D3, vol. 

2,1883, p. 99.
WALCOTT.] CORRELATION, 405

On the map of Adams County, based upon the results of geological 

work of Dr. Persifor Erazer, the quartzite resting upon Azoic is identified as Potsdam, with a question mark.

Safford. In his first report upon the geology-of Tennessee, Prof. J. 

M. Safford describes the method of the grouping of the strata into formations. He says: l

Wo often meet with a series of adjacent strata similar in many respects, so much 

so that they can conveniently be thrown together in a single group or .formation, as 

such a series is often termed.

He says further:

For example, the sandstone, slates, and coal which form the upper part of the Cumberland Table-land, are grouped in a formation, called the Coal Measures, with the following among other common characters : First, coal is found at intervals throughout 

the series; secondly, there is very little limestone or calcareous matter in the series ; 

thirdly, the strata are parallel, and appear to have been formed in succession, under 

similar circumstances; fourthly, the same fossils, such as different species of petrified shells, leaves, branches, and trunks of trees, etc., occur imbedded in the rocks 

throughout the length and breadth of the series. Characters similar to these unite 

the strata of all the formations.

The character last mentioned we must refer to more particularly, on account of its 

great importance in designating with precision the group to which local and isolated 

beds of rock belong.

In defining the use of fossils it is sta,ted that each formation has, in 

great part, its own fossils.

Most of those found in one do not occur in arty other. Upon this fact depends their 

great utility. They furnish, when known well enough to be recognized, unmistakable evidence of the geological position, and hence the general character of the formation in which they are found.

From these observations of Prof. Safford we postulate the principles 

of correl ation which he used, as follows:

I. Stratigraphic position.

II. The occurrence of similar fossils. 

III. Lithologic characters.

The New York series was traced into Canada by Sir Wm. E. Logan 

and his associates and correlations made by direct Stratigraphic connection, and in the absence of that, paleontologic data, Stratigraphic relations, and lithologic characters.

Logan. In speaking of the Stratigraphic succession of the New York 

and Canadian sections Sir W. E. Logan makes the following reference 

to the fossiliferous limestone above the Calciferous saudrock, or the 

Trenton limestone:

V

The lowest of the fossiliferous strata is a sandstone of variable quality, more purely 

siliceous towards the bottom, and calciferous towards the top, which gives support 

to a thick and remarkably persistent deposit of limestone, strongly distinguished by 

its organic remains. This limestone thus becomes an admirable means of tracing

1 A geological reconnaissance of Tennessee; first biennial report, Nashville, 1856, pp. 130,131.
406 . THE CAMBRIAN. [BULL. 81.

out the perimeter of the great western area under consideration. From the northAvest border of North Carolina it sweeps in a broad belt across Virginia to the junction of the Shenandoah and Potomac. Thence traversing Maryland, it passes 

through Pennsylvania by Harrisburg, on the Susquehanna, and Belvidere, on the 

Delaware,accompanied up to this point by the underlying sandstone. Diminished in 

its thickness, it thence crosses New Jersey, and reaching Poughkeepsie it passes up 

the valley of the Hudson and Champlain, keeping to the east of the river and the 

lake, and attains the neighborhood of Missisquoi Bay. Entering Canada, it proceeds towards Quebec, and it reaches the vicinity of that fortress; but I am not yet 

aware of the precise spots at which it is visible in its course thither, farther than 

that I have been informed a stratified limestone answering its condition is quarried 

and burned in the Seignory of St. Hyacinthe, east of the Yamaska Eiver. 1

He states that the city of Quebec does not stand on this limestone, 

but it is found below the city on the north shore of Beauport and 

farther down the river to Cape Tourtnent. Following up the valley of 

the St. Lawrence, it is found to run along the foot of a range of syenitic hills, and it leaves the river in the vicinity of Montreal and again 

appears in the Ottawa Basin. He then describes its extension south 

along the valley of Lake Chatnplain, and west through the valley of 

the Mohawk and Black River and north of Lakes Ontario, Huron, and 

Michigan, to Wisconsin, following thus the correlation made by Hall.

NEWFOUNDLAND.

The extension of the Canadian nomenclature to Newfoundland was 

the work of Messrs. Logan and Billings. In tracing the Paleozoic formations down the St. Lawrence Eiver from Montreal, Logan found that 

a series of sandstones occurs beneath the Calciferous sandrock, which 

was well recognized beneath the Trenton limestone. The sandstones 

rested unconformably upon the subjacent Archean. A long interval 

exists between these exposures and those on the north side of the 

Straits of Belle Isle, where sandstones and limestones are superjaceut 

to the Archean. In his first expression of opinion he calls the sandstones the Potsdam, from their stratigraphic position and lithologic 

character. When the fossils which were obtained from the associated 

limestones were examined by Mr. Billings and found to be identical 

with those that he had referred to the Lower Potsdam in Vermont, the 

strata on the north side of the Straits of Belle Isle were referred without reserve to the Potsdam horizon, and those occupying a similiar 

position on the west of Newfoundland were also similarly referred.2

When correlating the Lower Cambrian sandstones and slates of 

northern Vermont with the limestones and sandstones of the north 

shore of the Straits of Belle Isle, upon the lithologic and paleontologic 

similarities between the two deposits, Mr. E. Billings states that although 

SCO miles distant from each other there can be little doubt that»they 

are of the same age.

1 [Account of general structure of an extended area in North America.] Geol. Survey Canada, Report of Progress for 1843,1845, p. 8.

2 Geological Survey of Canada; Report of Progress from its commencement to 1803, pp. 97, 288, 

289,864,865. Montreal, 1863.
WALCOTT.] CORRELATION. 407

The occurrence of ^coliihus linearis and the general aspect of the fossils also show 

that these rocks must be very nearly, if not exactly, in the same geological horizon 

with the Upper Primal sandstones and slates of Pennsylvania. 1

The Lower Paleozoic rocks° of Newfoundland were correlated with 

those of Canada by Sir W. E. Logaii upon the evidence of the fossils 

and their stratigraphic position. The fossils were identified by Mr. 

Billings, and the stratigraphic geology was studied by Messrs. Richardson, Murray, and Howley.

J)ana. Prof. J. D. Dana availed himself of the correlations made by 

the New York, Canadian, and other surveys in the preparation of the 

earlier editions of his Manual of Geology. The Manual is a masterly 

compilation of'the available data upon broad principles of correlation, 

and as it went at once into the hands of all American geologists and 

students its influence has been widespread. The principles of correlation mentioned are outlined in the following paragraphs:

But the question may arise whether a geological age is not, after all, strongly 

marked off in the rocks. Rocks are but the moving sands or the accumulations of 

dead relics of the age they represent, and are local phenomena, as already explained. 

Each continent has its special history as regards rock-making, and it is only through 

the fossils in the rocks that the special histories are combined into a general system. 

Movements have in all ages disturbed one hemisphere without affecting the other, 

causing breaks in the succession of rocks in one continent or part of a continent that 

have no representatives in another.

When an age can be proved, through careful study, to have been closed by a catastrophe or a transition which was universal in its effects, the event is accepted as a 

grand and striking one in geological history. But the proof should be obtained 

before the universality is assumed. Hence the conclusion:

Fourthly. The grander subdivisions or ages iu geological history based on organic 

progress should be laid down independently of the rocks. They are universal ideas 

for the globe. The rocks are to be divided off as nearly as practicable in accordance 

with them.

Each continent, under these ages, then becomes a special study, and its history has 

its periods and epochs which may or may not correspond in their limits with those of 

the other continents. Every transition yi the strata, as from limestone to sandstone, 

clay beds or conglomerate, or from either one to the other, and especially where there 

is also a striking change in the organic remains, indicates a transition in the era from 

one set of circumstances to another; it may be a change from one level to another in 

the continents, a submergence or emergence or some other kind of catastrophe. All 

such transitions mark great events in the history of the continent, and thus divide 

the era into periods, and periods into epochs, and epochs, it may be, into subepochs. 

Hence 

Fifthly. Through the ages each continent had its special history ; and the periods 

and epochs in that history are indicated by changes or transitions in the rock formations and their fossils.

It is greatly to the assistance of research that some of the revolutions of the globe 

have probably been nearly or quite universal. The one preceding the Mammalian 

age appears to be an example; although, even with regard to this, further investigation is required before its actual universality can be regarded as established. But 

the periods and epochs of America and Europe are not in general the same in their

'Paleozoic fossils. Containing descriptions and figures of new or little known species of organic 

remains from the Silurian rocks. Vol. 1,1860-1865, p. 2. Montreal, 1865. 3?irat printed in 1861 in a 

bulletin issued by the Geological Survey of Canada.
408 THE CAMBKIAN. [BULL. 81.

limits. A near contemporaneity in rocks may be proved, bnt not in the transitions 

from one rock to another. For example, the Devonian age has a very different series 

of periods and epochs in North America from what it has in Europe, and there is 

even considerable diversity between the epochs of New York and the Atlantic slope 

and those of the Mississippi Valley. The Carboniferous, Reptilian, and Mammalian 

ages also have their American epochs and their European, differing from one another; 

and the differences between the continents increase as we come down to more modern 

times. There are Tertiary and Cretaceous rocks in America as well as Europe, but 

there is little reason for the assumption that the transitions from one set of Tertiary 

or Cretaceous strata to another were, in the two, contemporaneous. The point should 

be proved, not assumed. We add, therefore,

Sixthly. It is an important object in geology to ascertain as nearly as possible the 

parallelism between the periods and epochs marked off on each continent, and 

study out the precise equivalents of the rocks, each for each, that all the special 

histories may read as parts of one general history, and thus contribute to the perfection of one geological system. 1

MISSISSIPPI VALLEY.

The Lower Paleozoic rocks of this region were correlated with those 

of New York by Messrs. Owen, Locke, Hall, and others, usually without stating the data except by implication (e. g., speaking of the Trenton limestone of New York as a limestone carrying certain fossils and 

superjacent to a marked formation, the Calciferous sandrock of New 

York or the Lower Magnesian limestone of Wisconsin, etc.). Thus the 

correlation is based upon stratigraphic position, presence of similar 

fossils, and lithologic characters.

Hall. The following observations by Prof. Hall are a good illustration of the method by which the Potsdam sandstone of New York was 

correlated with the lower sandstone of the Mississippi Valley section :2

In comparing the older rocks of New York and of the East generally with those of 

the West it should not be forgotten that there is a long interval on the line of the 

northern outcrop of these ancient strata between the St. Lawrence and the western 

limit of Michigan on the Menomonee Eiver, where we can expect little aid from paleontology. The fossiliferous beds of these ancient formations in Wisconsin lie to the 

west of what appears to have been a great promontory at the time of their deposition, stretching southward from the region of Lake Superior far into the ancient sea. 

The disconnection caused by this promontory between the East and the West would 

of itself prepare us to expectja fauna differing in a great degree from beds of corresponding age on the opposite sides.

It has been shown by the investigations of the Canadian Survey that not only the 

Potsdam sandstone but all the fossiliferoua beds below the Birdseye and Black River 

limestones are absent from Kingston, on Lake Ontario, to Lacloche, on lake Huron. 

From Lacloche to Lake Superior there is a sandstone coming in below the Birdseye 

limestone, which, from its position, may be considered as of the age of the Chazy3 for1 Manual of Geology, 1st ed., New Haven, 1863, pp. 126-128.

Preliminary notice of the fauna of the Potsdam sandstone, with remarks on the previously known 

species of fossils and descriptions of some new ones from the sandstone of the Upper Mississippi Valley. 16th Ann. Eep. Keg. State Cab., Nat. Hist. N. Y., 1863, pp. 211-213.

3 The ' Chazy formation' of the Canadian Geological Survey, in its eastern localities includes a sandstone which comes in below the greater part of the limestone, leaving from 10 to 20 feet of shale and limestone beneath (Geology of Canada, 1863, p. 123). It is apparently this sandstone of the Chazy formation, having in Canada a thickness of 50 feet, which has become augmented in its western extension 

while the calcareous part of the formation has partially or entirely disappeared.
WALCOTT. J CORRELATION. 409

raation and equivalent to the St. Peters sandstone of Wisconsin and Minnesota, and 

it is this sandstone, doubtless, which has been taken for the Potsdam sandstone in 

some localities along that lino.

The succeeding Birdsoye and Black River formation from Lacloche to Lake Superior has become a buff-colored inagnesian limestone, or weathering externally to this 

color, but still holding the characteristic fossils.

In New York a sandstone (the Potsdam) lies immediately beneath a magnesian 

limestone (the " Calciferous sandrock"); this deposit is succeeded by a .calcareous 

formation (the Chazy), including a sandstone and surmounted by the Birdseye, Black 

River, and Trenton limestones.

In Wisconsin, Iowa, and Minnesota we have undoubted Trenton limestone, and 

below it a buff-colored magnesian limestone containing so many of the characteristic fossils of the Birdseye and Black River limestones as to leave no doubt of the 

parallelism of these beds with those of New York. Below this magnesian limestone 

we have the St. Peters sandstone, corresponding, as already shown, with the Chazy 

formation, and beneath this a magnesian limestone, which, in its position and lithological character, corresponds in all respects with the " Calciferous sandrock" of New 

York.

It is from all these facts that the lower sandstone of the Upper Mississippi Valley 

has been placed in parallelism with the sandstone of New York known as the "Potsdam."

Notwithstanding, however, that this sequence is precisely like that observed in 

New York it may not yet be regarded as proved that the sandstone from which I 

have described these fossils is in all respects the equivalent of the Potsdam sandstone of New York, Vermont, and Canada. It may represent more or it may represent less than that formation. The lower accessible beds of the Mississippi Valley 

may represent the Potsdam of 150 or 200 feet in thickness in the typical localities in 

New York, while the middle and upper beds of the West may be of epochs not represented in that part of the series studied in New York; and in some other places, as 

in the regions just mentioned, the same epochs may be represented by a shaly or 

semi -calcareous deposition, or may be included in the commencement of the Calciferous epoch. It should not therefore be regarded as decided that the Potsdam sandstone, as developed in New York, occupies the entire interval from the base of the 

oldest sedimentary formation of the Paleozoic era to the Calciferous sandstone. From 

what we know of the Primordial fauna in other localities we are prepared to find 

beds above or below, or both above and below, the epoch represented (so far as now 

known) by the Potsdam sandstone of New York, and which may still be of the same 

period.

WinclieU. It is stated by Prof. N. H. Winchell that 

It has been abundantly proved that the red sandstones of Lake Superior, however 

disturbed and changed locally, or however much increased in thickness by the agency 

of volcanic outbursts, are the exact equivalents of the New York Potsdam. They 

occupy the first position over the metamorphic slates of the Huronian rocks on which 

they lie unconformably, and from which they differ in being but slightly and only 

locally metamorphosed. They retain usually their evidently sedimentary characters, 

and have not well preserved fossil remains. 1

He also publishes a table showing the number of species common to 

various Silurian formations of the Lake Superior district and IsTew York 

State, and calls attention to the fact that three species only are found 

in the Lake Superior sandstone and the typical Potsdam sandstone of 

New York.

1 General sketch of the geology of Minnesota. Geol. and Nat. Hist. Survey, Minnesota, 1st Ami, 

Eep. for 1872,1873, p. 68.
410 THE CAMBRIAN. [BULL. 81.

The correlation by Prof. N. H. Winchell of the " Granular Quartz'? 

and the " Red sandrock " of Vermont with the " Potsdam " sandstone 

of the Upper Mississippi Valley and the " Primordial" quartzite of the 

Northwest appears to be based upon the fact that the " Granular 

Quartz" of Vermont and Massachusetts rests unconformably upon the 

Archean, and that a similar quartzite is superjacent to Archean rocks 

in the Mississippi Valley. This same principle of correlation appears 

in his statement that the stratigraphic relations of the " Granular 

Quartz " and the Potsdam of New York are the same. He says: "In 

the first place, they are seen to lie unconformably upon the older granite." l

Messrs. N. H. Winchell and H. V. Winchell correlated the Winooski 

marble series of Vermont with the Stockbridge limestone or marble 

belt of the southwestern portions of the State.2

This correlation is based upon (a) the assumed Primordial age of the 

iron-bearing limestones and shales of the Penokee-Gogebic range of 

Wisconsin and the Mesabi range of Minnesota, and their assumed stratigraphic identity with the limestones and shales of western Vermont, 

which correspond to the Stockbridge limestones and iron ores of western New England; (6) the known Cambrian age of the Winooski marble 

series.

Meek. As paleontologist of the Hayden and other surveys of the 

interior and western continental area, Mr. F. B. Meek's influence upon 

the correlation of fossiliferous strata was important. His views upon 

correlation by paleontologic .evidence are given in a report on the Paleontology of eastern Nebraska, as follows: 3

There are probably few well informed geologists who will at the present time 

maintain that the occurrence of a very similar or even the same group of fossils at 

widely separated localities necessarily proves the rocks in which they are found to 

be of exactly contemporaneous origin. The most that is now generally maintained 

in this regard is that such identity or correspondence of types at very distantly 

separated parts of the world indicates that the strata in which they are imbedded 

were formed during the prevalence of identical or similar physical conditions at 

some time during the same great geological epoch, and that they hold the same or 

nearly the same relative position in the geological column of their respective districts. 

For instance, although a stratum in the Rocky Mountains, containing the remains of 

very nearly the same fauna as some particular suhdivision of the Devonian system 

of Europe, might, for aught we know, be hundreds of years older or newer than that 

particular division, we would have little or no room for doubting that it belonged to 

the great Devonian series, or possibly even to some definite, known horizon in that 

series. We could moreover very positively assert in such a case that it would be, 

according to all past experience, useless to seek there at.any lower geological horizon for workable beds of coal, or to expect to find Silurian rocks or any of their pe1 The crystalline rocks of. Minnesota. General report of progress made in the study of their field 

relations. Statement of problems yet to be solved. Geol. and Nat. Hist. Survey of Minn., 17th Ann. 

Rep. for 1888,1889, p. 49.

2 The Taconic Iron Ores of Minnesota and Western New England. Am. Geologist, vol. 6,1890, pp. 

263-274.

3 Report on the Paleontology of eastern Nebraska, in Final Rep. of U. S. Geol. Surv. of Nebraska, 

Washington, 1872, p. 83.
WALCOTT.] CORRELATION. 411

culiar products above, supposing there had been no overturning of the strata at the 

particular localities.

Hence, although paleontology does not enable us to ascertain the exact actual ages 

of rocks, when applied with due caution and skill in connection with a careful observance of their stratigraphical arrangement and lithological and other physical 

characters, it does afford the means of fixing their relative ages, as well as of identifying the same beds at different localities, within given fields of observation, with very 

considerable precision. It is therefore not merely one of the more important aids to 

the geologist in his investigations, but in the present state of geological science it 

is the only sure guide in classifying and determining the order of succession of rocks 

where this can not be done by their actual continuity or obvious superposition. For 

these reasons it is now the universal practice in all geological surveys conducted 

upon sound scientific principles to devote especial attention to this department.

BOCKY MOUNTAINS.

Whitney. In speaking of the occurrence of the Primordial fauna in 

Nevada Prof. J. D. Whitney calls attention to the fact that the fossils 

are of Potsdam age, and that similar trilobites and brachiopods occur 

in Bohemia in argillaceous shales; throughout the United States, from 

New York to the Rocky Mountains, in the " Potsdam sandstone, or in 

the shales or slates;" in Texas and in Nevada, in limestone. He says:

This discovery will also indicate the necessity of caution in theorizing on the goological structure and age of regions which have only beeii hastily examined. It will 

not do to put down every red-sandstone group below the Trias in the far west as 

"Potsdam," for that subdivision maybe much lower down, hiding itself as a modest 

limestone of a very neutral tint of color. 1

Although not stated, it is evident that the principle of correlation 

used is purely biologic, or the occurrence of similar fossil remains.

Bradley. When describing the strata upon the western base of the 

Wasatch range, near Ogden, Utah, Prof. F. H. Bradley refers the 

quartzite, some 1^500 feet in thickness, to the Potsdam, and the gray and 

calcareous shales and limestones above to the Upper and Lower Silurian.2 A reference to the Upper Silurian was on the assumption that 

the limestone was the same limestone as that found 25 miles to the 

north, in which the characteristic Niagara coral Hatysites catenulata was 

obtained by Dr. Hayden in 1871. The data upon which the other correlations are made are not given. It is probable and almost certain 

that the presence of a quartzite beneath the limestone, supposed to be 

of Silurian age, was considered to be sufficient for the reference to the 

Potsdam sandstone. He correlates the glauconite sandstone beneath 

the limestone of the Teton range section, which carries Conocoryphe 

and Dikelocephalus, with the Knox sandstone of Safford, in Tennessee. 

Beneath them, and often present when they are absent, he found from 

50 to 75 feet of a very compact ferruginous quartzite " which must represent the Potsdam." 3

1 Note on the occurrence of the ' Primordial Fauna" in Nevada. Am. Jour. Sci., 3d sor., vol. 3,1872, 

p. 85.

"lleport of Frank H. Bradley, geologist of the Snake River Division. TJ. S. Gool. Sur. of the Terr., Cth 

Ann. liep. 1873, p. 194.

8 Op. cit., p. 216.
412 . THE CAMBRIAN. [BULL. 81.

It is evident that Prof. Bradley had in mind the Tennessee section, 

with which he was familiar, and 011 finding a quartzite, corresponding to the Chilhowee quartzite, and then a sandstone and shale corresponding in position to those of the Knox section, he correlated the two 

upon the evidence of serial relation of similar deposits and the presence 

of certain fossils in the limestone superjacent to the sandstone.

Fortieth parallel survey. The correlations made by the fortieth parallel survey of the Paleozoic rocks of Utah and Nevada with those of the 

eastern part of the continent, especially the New York section, are 

based almost entirely upon the paleontologic evidence as determined 

by Messrs. Hall and Whitfield. Within the area of the survey corre 

latioiis were made both on the stratigraphic succession of beds of different lithologic character, and the presence of similar organic remains. 

A correlation based on the " likeness of two great masses of rock to 

each other that occur beneath a known horizon " is made by Mr. Clarence King as follows:

Comparing the quartzites and argillites with those of the Cambrian section in 

Wales, the likeness is too great to pass unnoticed, and in view of the enormous developments of these low-lying rocks as compared with the Silurian lying above the 

Primordial horizon, I have determined to draw a line at the upper limits of the Primordial period to include the uppermost members of the Potsdam epoch, and to consider the whole underlying conformable series as Cambrian down to the point of 

their nonconformity with the Archeau. 1

Explorations and surveys west of the one hundredth meridian. The 

correlations made in the publications of this survey on the Lower Paleozoic rocks are mainly by Mr. G. K. Gilbert in his report on the geology 

of portions of Nevada, Utah, California, and Arizona.2 The data used 

for correlation are, the stratigraphic position, lithologic characters, and 

the presence of fossils of previously determined range.. No attempt is 

made to correlate by a study of the minor details of the faunas and 

strata except in the correlation of the Tonto of the Grand Caiion district with the Primordial formations of the East. From the known 

position of the genus Cruziana he argues that the beds containing it 

are Lower Silurian or Primordial. Mr. F. B. Meek compares the species 

of Olenellus found in central Nevada with 0. thompsoni and 0. vermontana of Vermont and thus indirectly correlates the faunas.3

Geological surveys of the Territories. The correlations made by the 

various writers of the Powell and Hayden surveys were principally 

based upon the paleontologic determinations of Mr. F. B. Meek and 

Dr. C. A. White outside the territory of the survey, and within its territory on stratigraphic positions, lithologic character, and fossils when 

present. In most instances the data for correlation are not given, the 

identification of the formations following that of previous workers in 

the same territory. An example of this is found in the " Geology of the

1 Paleozoic subdivisions on the 40th Parallel. Am. Jour. Sci., 3d ser., vol. 11,1876, p. 47G. 

2 Expl. and Snrv. West of 100th Merid., voL 3,1875, pp. 156-171. 

3 Op. cit., pp. 182,183.
WALCOTT.] COKRELATION. 413

Black Hills of Dakota," where a sandstone characterized by Upper 

Cambrian fossils is identified without comment as the Potsdam sandstone.

TJ. S. Geological Survey. In the consolidation of the various Government surveys and their reorganization under one head in 1879 the 

opportunity for broad comparisons and studies was increased, and the 

opportunities were still further increased in 1881, when the survey was 

extended to include the entire area of the United States. In the Eocky 

Mountain Province the correlations of the fortieth parallel survey 

were accepted, and extended in the abstract of the report on the geology of the Eureka district of Nevada. 1 In the report on the paleontology 

of the district the paleontologic data upon which the correlations were 

made are assembled and described.2 In this it is shown that while correlations between the great groups may be extended between the Appalachian Province and the Eocky Mountain area, it is impossible to 

correlate the minor divisions of the groups.

In 1886 an extended correlation of the rocks and fossils from the 

Lower Cambrian, then called Middle Cambrian, was published in Bulletin No. 30 of the U. S. Geological Survey.3 Typical sections are 

given of the Cambrian rocks of the Atlantic Coast, Appalachian, and 

Eocky Mountain Provinces, with the names of the species of fossils 

occurring in the various zones, and on page 44 the various sections are 

correlated and grouped in a table to show their relative range. The 

principles of correlation are not enunciated, but those used, as shown 

by the text, are the stratigraphic position of the faunas in relation to 

each other in the same province and a comparison of the faunas in one 

area with those of another.

In a more receut work4 the correlations are made between the various 

horizons of the Cambrian of the United States on the stratigraphic 

position of the strata and the occurrence of similar groupings of organic 

remains. It is observed that the presence of the Olenellus fauna is 

regarded as the strongest factor in the correlation of the Lower Cambrian, and it is assumed that the presence of this fauna indicates the 

same geologic horizon. It is not implied that the formations characterized by the Olenellus fauna are strictly contemporaneous wherever 

it has been found. On the contrary, its presence in such widely separated localities as England, France, Spain, Nevada, and British Columbia is considered as prima facie evidence that the deposits are not 

strictly contemporaneous. That they were contemporaneous in a geologic senseor that they occupy the same relative position in the geologic 

series is accepted throughout the paper.

1 Third Ann. Kept. TJ. S. Geol. Survey, 1883, pp. 248-272.

1 Mong. TJ. S. Geol. Survey, vol. 8,1884.

8 Walcott, C. D.: Second contribution to the studies of the Cambrian faunas of North America. 

1886.

''Walcott, C. D.: Tbn fauna of the Lower Cambrian or Olenellns zone. Tenth Ann. llopt. U. S. Gool. 

Survey, 1890, pp. 509-763.
414 THE CAMBRIAN. [BULL.SL

In his extended and valuable essays upon the history of the names 

Cambrian and Silurian in geology and the Taconic question in geology, 

and numerous other minor papers, Dr. T. S. Hunt 1 clearly sets forth 

the description of the various strata referred to the Cambrian and 

Silurian in America and Europe, and shows by testimony of different 

writers the relations the various formations sustain to each other, both 

stratigraphically and in their geographic distribution. Nearly all, if 

not all, the original correlations made by him are based upon lithologic 

data, as he believes in a uniform development and sequence of lithologic forms from earlier Archean time to the deposition of the fossiliferous sedimentary rocks. The correlations within the latter are largely 

made upon their stratigraphic, lithologic, and paleontologic characters 

as mentioned by authors.

CORRELATIONS WITH EUROPEAN FORMATIONS.

Numerous correlations were made between the strata of the formations of America and those of Europe by Messrs. Conrad, Owen, Kogers, 

Troost, Jackson, and others; but it was not until the investigation of 

M. Edward de Verneuil, in 1847, that correlations were made by one 

who had personally investigated the formations and fossils, both in 

Europe and America.2

De Verneuil. He began his comparisons with the view that superposition was the foundation of paleontology; that the only comparisons that could be made between continents separated by a sea was 

by a study, in each of them, of a series of beds confined between two 

zones at well determined points; that their fossils must be compared, 

and the identical species picked out to see if the species are distributed 

according to the same laws. He concluded that, if it happens in the 

two countries that a certain number of systems, characterized by the 

same fossils, are superimposed in the same order, whatever may be 

otherwise their thickness and the number of physical groups of which 

they are composed, it is philosophical to consider these systems as 

parallel and synchronous. Comparisons were made between the strata 

in the two countries that occur beneath the coal-bearing or Carboniferous rocks., He noted that the Potsdam sandstone with Lingula is probably analogous to the sandstone with Obolus, of Eussia, and the lower 

sandstones of Scandinavia. "These are in the two continents the 

most ancient pre-Carboniferous rocks."

The siliceous limestones, those of Black River and of Trenton, are the equivalents 

of a great part of the Lower Silurian stage of Europe, and they occupy the same posi1 History of the names Cambrian and Silurian in Geology. Canadian Nat., new ser., vol. 6,1872, pp. 

281-312,417-448. The Taconic Question in Geology. Mineral Physiology and Physiography. A second series of Chemical and Geological Essays. 1886, pp. 517-686.

2 Note sur le parallelisme des roches des d6p6ts pal6ozoi'ques de I'Aroeriqne Septentrionale avec 

ceux de I'Enrope, suivie d'un tableau des especea fossiles communes aux deux continents, avec I'indication des Stages oil elles se rencontrent, et termin6e par un examen critique de chacnne de ces especes. 

Soc. geol. Prance, Bull., 2" 8er.,vol. 4, pp. 646-709,1847. Translated and condensed by Prof. James Hall, 

Am. Jour. Sci., 2d aer., vol. 5,1848, pp. 176-183, 359-370; vol. 7,1849, pp. 45-51, 218-23}.
WALCOTT.] CORRELATION. 415

tion as the bituminous schists and the Orthoceratito limestones of Sweden and Russia. The Utica slate and the Hudson River group, with the Graptolitos at their 

base, represent the Graptolite slates which in Sweden succeed to the red Orthoceratite limestone. They are also the same as those of Bain in France. 1

Of the Upper Silurian rocks the Niagara group is considered the 

exact equivalent of the limestones and slates of Wenlock and of Gothland. The Clinton group, with Pentamerus oblongus, represents the 

extreme upper part of the Caradoc sandstone, or a stage intermediate 

between the Wenlock and Caradoc beds; while the five inferior 

groups of the Helderberg division represent the rocks of Ludlow. The 

correlation is then extended to the Devonian, and lists are given of 

identical species of fossils on the two continents.

Hall. The essay of M. de Verneuil was followed in 1851 by a paper 

on the " Parallelism of the Paleozoic deposit of the United States and 

Europe," by Prof. James Hall. In discussing the criteria of correlation 

he says :2

The simplest principles of elementary geology teach us that sedimentary beds, having the same thickness and the same lithological characters, can not have spread 

over an area so wide as that now included between the European and American continents. All sedimentary deposits must vary in character at remote points, as the 

physical conditions of the ocean can not be presumed to have remained the same over 

a wide extent of surface. Under such circumstances absolute parallelism is not to 

be sought for or expected. Calcareous deposits, as would naturally be supposed, have 

been found to be more persistent and more uniform in the character of their fossil con. 

tents; but these, over some portion of their extent, have often been invaded by 

argillaceous and arenaceous sediments, and the fauna is found to be in a greater or 

less degree influenced by such circumstances. In distant and disconnected localities 

we are compelled to base our opinions of the equivalency of beds upon the organic remains which they contain; and when we reflect that the nature of the sediment may 

in a great degree influence the character of the fossils we shall not fail to recognize 

the necessity of keeping the character of these lithdlogical changes in view. * * *

Besides the changes which take place in the nature of the sediment deposited upon 

the bed of the ocean, we are to look to other important conditions which may affect 

the fauna, and consequently our conclusions regarding the equivalency of formations. Among the most important of these is the depth of the ocean in which the 

animals lived, since we know that certain species are confined within certain zones, 

depending on the depth of the water.

There are other conditions which sensibly affect the distribution of organic life, 

such as temperature, pressure, and light. * * * In investigating the fauna of 

past ages we see nothing to lead us to believe that the same great laws which regu. 

late the distribution of species did not then operate with as great effect as at the 

present time.

In speaking of the attempted correlation between the European and 

American rocks Prof. Hall remarks:

All the attempts to show that the parallelism of American and European paleozoic 

deposits have been with a view to find a correspondence with the European standard where the series is confessedly incomplete, and where it has suffered during its 

deposition, or subsequent to it, many disturbances. 3

1 Op. cit., p. 361.

2Roport on the Geology of the Lake Superior Land District, by J. W. Foster and J. D. Whitnoy. 

Part n, 1851, pp. 286,287. 

8 Op. cit., p. 294.
416 THE CAMBRIAN. [BULL. 81.

Tlie author agrees with M. de Verneuil that the Potsdam sandstone is 

represented in Eussia by the beds containing Obolus and Lingula, and 

in Scandinavia by the sandstones which rest uncouformably upon the 

gneissoid and schistose rocks composing the Azoic system. Of the 

Chazy, Birdseye and Black Eiver limestones of New York he says:

They are not very clearly recognized in Europe. It is probable that some part of 

the Orthoceratite limestone of Sweden is the equivalent of the Black River mass; 

but we have no evidence, from fossils or otherwise, that there are any representatives of the two lower rocks. * * *

The Trenton limestone, the Utica slate, and the Hudson River group are represented in northern Europe by the Orthoceratite limestone of Sweden and Russia and 

by the shales with Graptolites, which succeed to that limestone. In Great Britain 

the Llandeilo flags and Caradoc sandstone are clearly the equivalent of these groups. 

It is here that we first find a number of species identical with European ones, and 

which enable us to institute a comparison. It will be found, however, that the 

species in the Hudson River group correspond most nearly with the European forms, 

and that it may be doubtful if the base of the Trenton limestone has been reached in 

Great Britain. 1

The Clinton group, with its beds of Pentamcrus oblongus, represents what in England is regarded as the upper part of the Caradoc sandstone; but we find it not 

only above this well marked horizon, which w e have already indicated, but associated with numerous species of fossils, some of which are known as upper Silurian 

forms in Europe, and others pass into forms characteristic of the Niagara group in 

this country.

The Niagara group, with its shale and limestone, would seem, at first view, to be 

the exact equivalent of the shale and limestone of Wenlock and Dudley in England, 

and of Gothland in Sweden, so numerous are the identical species in these groups; 

but on examination we find that there are numerous species included in these rocks 

in Europe which occur only in the lower Helderberg limestones, and which are 

separated from the Niagara by the enormous deposit of the Onondaga salt group. 

It is clear, therefore, that in the Wenlock formation of England and its representatives in northern Enrope are included parts at least of two distinct groups in the 

order of time distinct both in their physical and zoological features; and we can 

not institute a proper comparison between the rocks of our own country and th ose 

of Europe while we regard that as one group. The condition, both in England and 

on the continent, is doubtless similar to what we find in Tennessee and Virginia, 

where, from the absence of the intermediate groups not only the Niagara and lower 

Helderberg are united together, but even the upper Helderberg limestones are 

superadded.2

Barrande. A. correlation based upon paleontologic data was made by 

Mons. J. Barrande, in 1853, between the formations characterized by the 

first, second, and third faunas of Europe and those included in the 

Silurian of America. In commenting upon the identification of the 

Kussian Obolus apollinis Eichwald, by Owen, with the Potsdam sandstone species of the Upper Mississippi Valley, he says:

In fact I am inclined to think that science has passed out of the epoch when it was 

thought necessary to have identical species in order to recognize equivalence of geologic horizons, even at great distances on the earth's surface. The distribution of our 

present fauna teaches us that this means can not be altogether relied on to prove 

dtrata contemporaneous.3

1 Op. cit., pp. 295, 296. 2 Op. cit, p. 299.

 Barrancle. J: (Silur-fauna in Wisconsin und in New York.) Noues Jabrbucli fiir Miner., 1853, p. 

338.
WALC07T.] CORRELATION. 417

The fact that the Paleozoic formations of America during the appearance and disappearance of three successive faunas, which despite some common species are on the 

whole well distinct, teaches us that the extinction and appearance of beings on the 

earth's surface are by no means determined exclusively by the physical revolutions 

of the crust, but are ordered and regulated by the laws of animal creation itself. 

Still, it is not my intention to follow out this consideration, as it would lead me too 

far. I merely wished to mention this, in passing, as a subject for further study, and 

to point out to investigators that paleontology leads to the establishment of a geologic chronology, independently of the more or less local revolutions which the fossiliferous strata have undergone since their deposition.1

From a study of the faunas of the two countries he considered that 

the first, second, and third faunas of Bohemia are to be identified in 

America; that there exist manifold relations in all classes of animals of 

the Upper Silurian division of the United States and Bohemia; that, 

in the first volume of Hall's Paleontology of New York, on the Lower 

Silurian division, from the Potsdam sandstone to the Hudson River 

group inclusive, he recognizes the First Silurian fauna of Bohemia, 

Sweden, and England; that the presence of the long-missed first fauna 

of Bohemia in America has been demonstrated in a very satisfactory 

manner by Owen in his discoveries in the northwestern United States; 

and that the occurrence of this fauna in the State of Georgia is indicated by a Couocephalus brought to England. In conclusion, he says:

Hence I am now perfectly convinced that the Silurian formations of North America, as well as those of the old continent, contain a succession of three different faunas, 

which, on being separately compared with the latter, are seen to consist of the same 

geologic elements and to follow each other in the same order. When I say that they 

consist of the same geologic elements you know already that I am far from wishing 

to maintain identity of species. I rely on other more general analogies which to me 

'ure not less convincing. This is not the place to explain this more in detail, as that 

would lead me too far; but you will find here and there in my work some passages 

which express my view of the matter. In admitting and recognizing in all Silurian 

regions of the two continents three general faunas corresponding and equivalent to 

each other, I am induced by the facts to pronounce a further result of my investigations, namely, that the local divisions of strata containing these great faunas, though 

greatly differing from each other in each region of a certain extent, are not equal to 

each other in the various countries, especially when the countries are far apart, geographically. This truth seems to me solidly established by a multitude of facts 

which are tabulated and compared in niy geologic sketch, and is confirmed in a very 

satisfactory manner by the facts mentioned in volume 2 of J. Hall's Paleontology of 

New York.2

Rogers. In a paper read before the British Association for the Advancement of Science in 1856, on the correlation of the North American 

and British Paleozoic strata. Prof. Henry D. Rogers described the 

Paleozoic section of the Appalachian region and that of England, and 

instituted comparisons between them, to show the parallelism of the 

North American and European Paleozoic rocks.3 He says:

In attempting this correlation it should be remembered that nature represents no 

true or literal equivalency of strata, nor anything closer than a mere approximate

1 Op. cit., p. 339. »0p. cit., p. 345.

3 On the correlation of the North American and British Paleozoic strata. British ABBOC. Adv. Sol., 

vol. 26,1857. Trails. Seo., p. 184.

Bull. 81 27
418 THE CAMBRIAN. IBULL.SL

relationship where the deposits compared belong to independent basins, or even to 

the remote sides of the same great receptacle. The most we can hope to establish is 

a general agreement in time, with possibly a stricter synchronism of the few chief 

paroxysmal movements which agitated the bed of the ancient ocean. Partially representative formations are discoverable, but equivalent ones are not to be looked for 

upon any philosophical view, since the distribution of organic beings is essentially 

partial or geographical. The life horizons of the globe are no more universal than 

are its horizons of sedimentation. With these reservations we turn to the degrees of 

affinity, linking the American and European Paleozoic groups of fossils.

As the result of his correlation he concludes:

(a) The Appalachian Primal series is obviously nearly on the horizon 

of Barrande's Primordial zone and the lowest rocks of Eussia and 

Scandinavia.

(b) The Appalachian Auroral strata may possibly be approximately 

contemporaneous with the Swedish Orthoceratite limestone. The 

Auroral series includes the Calciferous, Chazy, and Black River groups.

(c) The Matinal series of the Trenton and Hudson Eiver groups, 

from the testimony of the fossils, are represented in Britain by the 

Llandeilo flags and Caradoc sandstone, or more generally by Sedgwick's 

Bala or Upper Cambrian group. He also finds a near equivalent in the 

Orthoceratite limestone of Sweden and Eussia and in the Graptolite 

shales. The authority of Prof. Hall is cited, to show the paleontologic 

similarity of the English and American formations.

(d) The Levant or Medina group does not appear to be represented in 

Europe.

(e) The Surgent and Scalent series, or Clinton and Niagara, are compared with the British Weulock strata.

(/) The Pre-meridian series or Lower Helderberg. He quotes Mr. 

Hall as saying that.he agrees with Mr. Sharpe and regards the Lower 

Helderberg strata as representing the Wenlock formation of England, 

while M. de Verneuil considers them as equivalent to the Ludlow. He 

then proceeds to correlate the Devonian formations with those of Europe.

His final conclusion is:

From all the foregoing facts and statements we arrive at this general inference, 

that upon both paleontological and physical evidence there is no well marked Silurian-Devonian break discernible in the North American basin, no proof of an epoch 

or general interruption in the life-stream, with wide crust disturbance in the middle 

Paleozoic ages, such as that which in earlier times, in the morning of the Paleozoic 

day, at the Cainbro-Silurian transition, revolutionized alike the entire extent of tha 

American and European areas, both in their inhabitants and in their physical geography.1

Bigsby. A most elaborate comparison and correlation between the 

Paleozoic section of New York and that of Wales was made by Dr. J. 

J. Bigsby in 1859. He observes that u both these geological areas appear to have been constructed on the same great comprehensive principles and nearly of the same material, two most important considera1 Op. cit., p. 186.
WALCOTT.] COREELATION. 419

tioos. One very great, distinction between them, however, is that they 

have received different dynamic treatment, in the frequency of plutonic 

disturbance in Wales and its comparative absence in New York, such 

dynamic treatment involving, it must be kept in mind, both gradual and 

sudden changes of population. While the strata of these areas are 

formed of much the same mineral substances, the conditions of these, 

their order, and quantities are very varied." 1

He sums up the points of zoological similarity under the following 

heads:

(1) The organic remains of both basins belong to the same orders and genera, unmixed with those of other sedimentary systems, as Permian, Jurassic, etc.

(2) Vertebrate auimals were introduced at nearly the same date.

(3) The organic remains approximate closely in general facies.

(4) They affect strata of the same mineral character in both, the majority preferring the calcareous, the others the arenaceous form of deposit.

(5) The great majority exhibit the same order in their introduction and distribution. This is seen in Orthis, Peutamerus, Spirifer, and oth^r Bracliiopoda, and in 

Endoceras, Graptolites, Trilobites, etc., the more highly organized being often prominent in the early stages.

(G) The law of divergency into several matrices is the same, or nearly so, in the 

two basins, the number of instances being fewer in New York.

(7) The great majority of animals typical or recurrent in one basin -are so in the 

other.

(8) The great majority of the recurrent fossils in both occupy the same number of 

epochs, many or few.

(9) The great majority observe the same process or law of increment and decrement. This takes place in nineteen out of twenty-four orders and genera.

(10) The two basins have 108 organic forms in common, including most of the genera.

(11) The same orders and genera are rich and poor in species.

(12) There is the same limited admission of Silurian forme into the Devonian system in New York alid in Europe.

(13) The plants of both are typical, with one or two exceptions.

Such are some of the great points of similarity. Now as to dissimilarity. Those 

which arise out of the mineral character are partly owing to physical disturbances 

and to a certain amount of metamorphisui undergone by the Welsh strata. The 

paleontological differences are many, but small, often merely individual, and they 

seldom affect principles. They are clue to the varying sea depths and other well 

known conditions.

The facts just recorded certainly indicate a close connection in nature and mode 

of formation between the basins of New York and Wales. They seem to be quasiequivaleuts the same, but other, to use a short, but convenient phrase in common 

use. 2

Agassiz. When commenting upon correlations made between the 

Paradoxides zone of Newfoundland, Massachusetts, and Scandinavia, 

Prof. Louis Agassiz said :

That there may be synchronism of deposit without identity of fossils must be evident if we glance at the present distribution of animals. If at the present epoch 

the fauna of America and Australia should become fossilized there would not be the 

slightest resemblance between the representative species of the two continents. The

1 Quart. Jour. Gool. Soo., London, vol. 15, 1859, p. 292. 2 Op. cit., pp. 292,293.
420 THE CAMBRIAN. [BULL. 81.

paleontologist must be ready to admit that very different fossil faunas may be contemporaneous, and that their difference does not necessarily imply a distinct zoological age. 1

When discussing the typical forms and the distribution of the rocks 

of the Cambrian, Mr. J. J. Bigsby presents a table showing the order 

of succession of the Cambrian rocks in various countries.2 In this he 

includes the Upper Cambrian sandstones of Texas and Nebraska, aud 

they are referred to the upper or Primordial division of the Cambrian.

Matthew. During the progress of his extended researches in the 

faunas and rocks of the Cambrian system in New Brunswick, Mr. G. 

F. Matthew has had frequent occasion to compare the stratigraphic 

succession and the faunas of the Cambrian of New Brunswick with 

that of Europe.

In a paper read before the British Association for the Advancement 

of Science in LS84, he correlates the fauna of the St. John group of 

New Brunswick with that of the Cambrian of Wales, and concludes 

that it shows closer relations with the Solva group than with the Meneviau.3

Near the close of the same year lie stated in a paper read before the 

Natural History Society of New Brunswick that the discovery of a 

higher fauna enabled him to correlate the beds containing it with the 

Menevian group of Wales.4

In an essay on the classification of the Cambrian rocks in Acadia,5 

Mr. Matthew considers that the Potsdam sandstone is equivalent to 

the Ceratopyge limestone, or the Tremadoc group, and represents the 

upper part of the Tremadoc, as the Georgian series probably does the 

lower. This correlation is made upon the interpretation of the characters of the genera of trilobites in the American and European rocks.

A second paper on the classification of the Cambrian rocks in Acadia 

appeared in 1889, in which a comparison of sections in Sweden aud 

New Brunswick with the characteristic sections of Cambrian rocks in 

Europe and in North America is made.6 In the comparison of sections 

of Sweden and New Brunswick the base of the Paradoxides beds is taken 

as the datum point and it is shown that the pre-Paradoxides horizon is 

present both in Sweden and New Brunswick, and that the Upper Cambrian or Olenus horizon is represented in New Brunswick by Stage 2 

of the St. John County section and by the same stage in Sweden. In 

the second table of the sections of the Cambrian rocks in Europe and in 

North America, the correlations made between the sections of Sweden 

and New Brunswick are accurate and valuable; but those between the

'On tbe difference between faunas of zoological and geological periods. Boston Soo. Nat. Hist., 

Proc., vol. 8,1862, p.58. 

3 On the Cambrian and Huronian formations. Geol. Soc. Quart. Jour., London, vol. 19,1863, p. 44.

3 The geological age of the Acadian fauna. Brifc. Ass. Adv. Sci., Bop. 54th meeting, 1881, pp. 742, 743.

4 An outline of recent discoveries In the St. John group. Nat. Hist. Soc. N. B., Bull, No. 4,1885, 

p. 101.

6 Canad. Eec. Sci., vol. 3,1888, pp. 79,80. . . 

6 Canad. Eec. Sci., vol. 3,1889, pp. 308-311.
WALCOTT.] CORRELATION. 421

western North American sections of the Wasatch, Nevada, Highland 

Eange, and Eureka are more or less defective, owing to the imperfect 

interpretation of the paleontologic data.

The next essay upon the correlation and comparison of the European 

formations with those of America by Mr. Matthew is entitled: "How is 

the Cambrian divided? A plea for the classification of Salter and 

Hicks." l He institutes comparisons of the strata in Wales, Newfoundland, and Norway, and of the characteristic trilobitic genera of each 

horizon. From the results obtained by these comparisons he considers 

that the Cambrian is to be divided into the Upper and Lower, arid that 

the method proposed by Mr. C. D. Walcott, of separating the Olenellus 

or Lower Cambrian from the Paradoxides or Upper Cambrian, is not 

justified by the evidence afforded by the American and European sections.

METHODS OF CORRELATION.

I. Superposition.

II. Organic Eemains.

III. Lithologic Characters.

IV. Unconformity. 

V. Miscellaneous.

I. SUPERPOSITION.

8

(a) The order of superposition of strata is the foundation of geologic 

chronology. By its aid the stratigraphic succession and serial relations 

of the fossil faunas are first determined. Undisturbed superposition 

within a section is an absolute test of relative age of the parts of that 

section; it is not positive evidence of the age of the various bods in 

relation to beds sustaining the same serial relations in some disconnected section without other tests to support it, even though they 

occur in the same geologic province: e. g., a band of sandstone beneath 

a limestone and above a shale may be identified in one portion of a 

geologic province; but the occurrence of a band of sandstone beneath 

a limestone and above a shale, in a distant portion of the same province, 

is not positive evidence that the two bands of sandstone are synchronous or portions of one continuous formation, unless their continuity 

can be traced.

(b) Superposition is not a test of identity of formation except in a 

limited basin, where the geologist has evidence to show that the formation is practically continuous in its stratigraphic relations. In widely 

separated portions of the same basin, or of different basins, the order 

of superposition must be sustained by other tests before it can be asserted positively that the formations thus correlated are identical.

(c) In the same geographic or geologic province, fresh-water and 

marine deposits are not to be correlated with each other, even if they

'Am. Geologist, vol. 4,1880, pp. 139-148.
422 THE CAMBRIAN. luuLr..8t

have the same order of superposition, as the conditions under which 

they were accumulated are entirely dissimilar, and the proof of the 

contemporaneity of deposition is not available. An exception to this 

may occur where a stream passes through a lake and carries the fauna 

and flora to the sea, where it is mingled with the marine fauna.

II. ORGANIC RHMAINS.

There are several considerations always to be borne in mind in correlating a formation on the evidence of its contained organic remains:

(a) There can be no scientific or systematic paleontology without a 

stratigraphical basis.1

(b) The method of correlation by the comparison of fossils; or, as ft 

has been called, "matching," is the one that affords the best results. 

It includes the comparison of species, genera, families, and the general 

facies of a fauna. It is the basis of paleoutologic correlation and geologic classification of the sedimentary rocks, with the exception of the 

stratigraphic and lithologic correlation of local formations.

(c) In nearly every section of strata there are considerable thicknesses of beds, in which, no fossils are to be found. These beds occur 

in nearly every formation. The record of life, during these uonfossiliferous periods of sedimentation, is broken.

(d) Many fossils have a great vertical range; and the occurrence of 

a few species of this character without the presence of species of known 

limited range can not be taken for the identification of any particular 

formation. If the laws of constancy and variation of the wide-ranging 

and long-enduring species are known, it may be possible to use them in 

the correlation of minor formations, and thus create an exception to 

the general rule.

(e) All paleontologie reasoning is based upon known data. By the 

discovery of a new grouping of fossils, or a different range of known 

species, the identification of horizons may be materially modified.

(/) In correlating a formation it is necessary to exercise caution before deciding that the contained fossils belong to any specified zone of 

the fauna characterizing a terrane or group of formations, and thus 

locating the exact stratigraphic horizon of the formation. A fauna 

may vary in its constituent parts and afford different groupings of 

species in localities not far distant.

(g) All correlations between widely separated provinces are based 

upon the general and not upon the specific character of the fauna; i. e., 

it is the general assemblage of a fauna in one basin that is compared 

with that in another basin.

Within limited areas the comparison of species and the grouping 

of species suffice to determine some particular horizon or formation. 

In widely separated parts of the same area or province there will

'Hall, James. On the Primordial fauna and Point Levi fossils. Am. Jour. Sci., 2d ser., vol. 31, 

1861, p. 224.
.WALCOTT.] CORRELATION. 423

be a greater difference in the species, and the general or the specific grouping of the genera will have to be taken as the data for comparison. In separate provinces the species may be the same in some 

instances; but it is by the comparison of representative species and 

genera that the correlations are to be made. In provinces separated 

by great distances, or upon two continents, the general assemblage of 

the characters of the two faunas are to be compared. It may be 

accepted as a general rule that the more detailed the comparisons are 

the more restricted is'the area in which specific results are of value. 

The results, however, may be of the highest value in strengthening a 

correlation based upon representative types. The exception to this is 

the occurrence of similar life zones in widely separated regions.

(h) Zoologic provinces have been more or less limited in area from 

the beginning of Paleozoic time. This is shown by the character and 

distribution of the earlier Cambrian fauna. The provinces were as distinctly marked then as at any time during the deposition of the Paleozoic.

(i) Many of the earlier zoologists and paleontologists prior to the 

period of Darwin studied the strata and the contained fauna with the 

view that each, group of species had a greater or less distribution and 

were then suddenly exterminated, a newly created fauna taking its 

place. This enabled them, to correlate their formations with great 

accuracy, and to differentiate them upon the evidence offered by the 

occureuce of a very few species.

(j) The environment or condition under which the faunas lived and 

were deposited is also to be noted. Whether they were littoral or 

pelagic, whether they lived in cold or warm water, upon a sandy or a 

muddy bottom, in salt or in fresh water, are all considerations which 

must be taken into account in discussing their value as factors in correlation.

(7c) The presence of recurrent faunas in strata lithologically similar 

may give rise to imperfect and erroneous correlations. This is not 

liable to occur except in a limited geologic basin, where the conditions 

of sedimentation were uniform over large areas, and the environment 

of the fauna such that it continued, under favorable conditions, in some 

portions of the basin, and occupied other portions intermittently, as 

the varying phases of sedimentation were favorable or inimical to its 

distribution.

(I) The relative age, serial relation, or homotaxis of sedimentary 

formations is best determined by the marine faunas, as the conditions 

under which they lived and were deposited were much more uniform 

than those surrounding the terrestrial fauna and flora.

The evidence furnished by paleobotany is fragmentary, and its sequence is so interrupted by uondeppsition and nonpreservation that 

no comparisons of great value have been established by its aid. What 

is true of paleobotany is also true, to a less extent, of terrestrial faunas.
424 THE CAMBEIAN. [BULL. 81.

It is only by accident and through peculiarly favorable conditions that 

land faunas have been preserved. With the marine faunas on the contrary the opportunities for the preservation of the fauna of each epoch 

were far greater, and the conditions of environment were more favorable 

for the uniform advancement and evolution of life over extended areas. 

Life-zones. The proof of the presence of life-zones in the geologic 

series is one of great importance in correlation. The subject has been 

so ably presented by Prof. H. A. Nicholson that I will quote it in full 

in preference to giving a synopsis of it or to presenting my own views, 

which accord essentially with those of the author. He says:

While each geological rock-system is characterized by a general assemblage of distinctive types of animals and plants, the minor subdivisions of each system are likewise distinguished by the prevalence of particular forms of life. There are no doubt 

cases in which an extensive series of successive strata may appear to be characterized 

throughout by essentially the same organic typos, there being apparently no restriction of special fossils to special horizons in the series. In so far as such cases have 

any real existence, they may be explained as instances in which a great series of sediments has been accumulated with such rapidity that there has been no time for 

marked biological changes, resulting in the dying out of old species and the introduction of new forms. In many cases, however, the apparent diffusion of the same 

kinds of fossils from the base to the summit of a series of beds perhaps two or three 

thousand feet in thickness is due simply to the fact that the organic remains met 

with in the formation have not been sufficiently investigated and that the exact 

horizon at which each occurs in the series has not been accurately determined. The 

determination of the horizons of particular life-forms is a work of time and demands 

both great strati graphical knowledge and also a wide and accurate acquaintance 

with the characters of the fossils themselves, two requirements rarely fulfilled in the 

earae individual.

In a considerable number of cases, however, it has now been shown that the fossils 

of a given formation may be divided into two principal groups. In the one group is 

comprised a series of common forms of life, which may be regarded as characterizing 

the formation as a whole. In the other group are included certain special fossils confined to particular parts of the formation and characteristic of certain definite liorizons or zones, within the limits of the formation. All the great formations are to some 

extent capable of being broken up into minor rock-groups, characterized by special 

life-forms. Some of the differences in the kinds of fossils found in different parts of 

the same formation must, of course, be simply set down to the fact that different 

kinds of sediment imply changed conditions in the sea, and hence changes in the 

marine fauna. If, for example, part of a formation consisted of limestone and part of 

sandstone, we should expect, beforehand, to find that each of these rock-groups would 

have some fossils not found in the other, since the two would have been formed under 

different conditions. Apart, however, from differences arising from causes of this 

nature, we meet with cases in which a formation, even if essentially homogeneous in 

its mineral nature, can be divided into zones, each of which is characterized by the 

possession of special groups of fossils. Organisms belonging to any class of animals 

may serve in this way as test forms (" Leit-Fossilien ") for special horizons in a series 

of stratified formations, bat there are particular groups of fossils which have been 

found to be preeminently available for this purpose. Among the older rocks of the 

earth's crust, the forms which have proved specially valuable for the determination 

of particular "zones" are the Graptolites, the Trilobites, and the Brachiopods, while 

the Cephalopods have been found to afford the most satisfactory tests in the case of 

the Secondary rocks. A well known instance of this subdivision of a system of strata 

by means of special types of fossils is that afforded by the Ordovician and Silurian
WALCOTT.) COERELATION. 425

rocks of Europe, in which paleontologists, follow!ug Professor Lapworth, have recognized numerous well marked "life-zones," characterized for the most part by the 

possession of particular types of Graptolites, though, in some cases, the distinctive 

fossils belong to other groups Another well known example of the same phenomenon is afforded by the Jurassic deposits. These have been shown to contain a number of well marked zones, each of which is characterized by the possession of some 

special fossils, and particularly by some special Ammonite. These zones are extremely 

constant in any particular region, and they enable the observer to effect a division of 

the formation into special horizons, which have no stratigraphical existence and are 

not separated by any physical break, but are of the utmost paleontological importance andean be rendered readily available in working out the stratigraphy of any 

given area.

Certain life-zories appear to have nothing more than a local development and importance, but in other cases they have proved to be astonishingly constant even over 

very large areas. Perhaps the most remarkable known instance of the extension of 

particular life-forms over a vast area is that afforded by the Areuig rocks (a subdivision of the Ordoviciau system), which have been recognized as occurring in Europe, 

in Canada, and in Australia, and contain in all these widely remote areas the same 

peculiar types of Graptolites.

The principal difficulty that we have to confront in dealing with these " zones" is 

to produce any plausible explanation accounting for the destruction of the special 

life-forms of the one zone and the appearance of those of the next zone. For tho most 

part, these zones are of very limited vertical extent, and they succeed each other in 

such a manner as totally to preclude the idea that the dying out of the old forms can 

have been in any way caused by a physical disturbance of the area. Perhaps tho 

most probable view to adopt in the meanwhile is that the formations in which distinct and limited life-zones can be recognized were deposited with extreme slowness, 

whereas those which show an essentially compact and homogeneous fauna from base 

to summit were deposited with comparative rapidity. Upon this view, a formation 

like the Lias i« one formed by a process of very slow and intermittent sedimentation, 

tho life-zones being separated by intervals during which sedimentation must have 

been at a standstill, but which were long enough to allow more or less considerable 

biological changes, some forms dying out or becoming modified while other new ones 

came in. Upon this view, further, a formation like the Lias, though of comparatively small vertical extent, may represent as long a period of time as the whole of 

such a great formation as the Lower Carboniferous, which appears to have been 

formed under conditions of comparatively rapid sedimentation. 1

Lite-zones Lave been determined in the Middle Cambrian or Paradoxides terrane of Sweden, Wales, New Brunswick, and Newfoundland 

or the Atlantic Basin Province. In a broader range the genera 0Olenellus, Paradoxides, and Dikelocephalus are considered typical of the 

three primary zones or divisions of the Cambrian group. They are of 

unequal value and decrease in precision from the older to the later 

faunas. The genus Oleuellus has a wide distribution in western Europe and North America, while Paradoxides is more limited in America, and the true Dikelocephalus probably has a still smaller geographic range.

Stage of evolution. The evolution of organic life is a factor in correlation that has been assuming some importance within the last few 

years. To be of practical use the paleontologist must have a thorough.,

1 G-eneral Introduction, Manual of Paleontology, by H. A. Nieliolson and B. Lydekker, vol. 1, 1889, 

pp. 58-60.
426 THE CAMBRIAN. fuuLL.81.

accurate knowledge of the species and their life history, including that 

of the genus and family to which they belong. Types of restricted 

range and short duration are of little importance, except as expressing 

the stage of development of their genus. The persistent, long-enduring 

types, that range from formation to formation and even from group to 

group, may be of service if their study and analysis have revealed 

characters by which their relative stratigraphic position, in a given 

area, may be determined. The evolution of genera is of greater value, 

and the analyses of the development of specific types within them may 

be used in the identification of horizons.

Extended to groups of genera, families, or orders, correlation by the 

known evolution of the faunas may be used in a general way. In the 

presence of other reliable data it is of relatively small value. Only in 

instances where there are no other data that can be made available will 

it be really of practical service to the geologist.

Even under the best conditions and circumstances great care must 

be used, owing to the varying conditions caused by environment aud 

the unequal evolution of organisms in different geographic areas or 

basins. I do not wish to imply that this method of correlation should 

be entirely overlooked or dismissed in the presence of more reliable 

data. It can be used in connection with other methods in correlating 

any formation or group of formations, but only in extreme cases should 

it be considered the only factor. When used, the result obtained can 

be considered as little more than provisional.

Life history. A careful study of the life history of the various elements of the faunas promises to yield data that may be important in 

correlation. An illustration of this is afforded by Prof. H. S. Williams's 

study of Spirifera Icevis. 1 This is a type that is represented by various 

forms from the Niagara limestone of the Silurian to the summit of the 

Devonian, that are evidently descended one from the other, although 

they have been described under several specific names. At each horizon the variation from the initial form serves to locate its stratigraphic 

horizon and thus its relative age and position in space and time. The 

tracing of the migration of forms from one area to another and the 

changes produced upon them during this migration are to be taken 

into consideration. The theory of Prof. Alpheus Hyatt,2 that there is 

a cycle of forms in the geologic series and a corresponding cycle of variation in the species of that series and in the individuals of any one species, may lead to practical results. He finds it to prevail very extensively in the Cephalopoda, and it will undoubtedly be found to apply 

to all the other zoologic groups. The conclusions obtained will be more 

or less marred by the imperfections of the geologic and life record, but 

I look forward to the time in the future when minute biologic studies

1 The Life History of Spirifer laevis, Hall. Ann. IT. Y. A cad. Sciences, vol. 2,1881, pp. 140-160, pi. xiv.

2 Genera of Eossil Cephalopods. Proc. Boston Soc. Nat. Hist., vol. 22, 1883, pp. 253-265. Also, many 

other papers by Professor Hyatt, referring to and describing the Cephalopoda.
WALCOTT.] CORRELATION. 427

of the faunas, in connection with a careful study of the sedimentation 

and stratigraphy, will make our present methods appear to have been 

lacking in scientific precision.

Contemporaneity and Homotaxis. When it was once established that 

a certain order of succession of fossils occurred in Europe, it was concluded that identical or similar assemblages of organisms would be 

found to prevail elsewhere over the earth ; and that the geographic 

distribution of each successive fauna was world-wide, each fauna being 

a new creation. The present view is, that the chronologic succession 

of the fauna is local, as proved by the existence of zoologic provinces, 

and that each fauna is descendant from some preexisting fauna. This 

result is modified for each province by the migration of faunas and 

portions of faunas from province to province. Notwithstanding the 

various elements that influenced the evolution of the faunas, it is found 

that the general succession of species and faunas is in the aggregate the 

same all over the world, however much it may have been broken, advanced, or retarded in certain areas in ancient or relatively recent 

geologic time.

Prof. Huxley, when introducing the term " Homotaxis," said:

Edward Forbes was in the habit of asserting that the similarity of the organic contents of distant formations was priuia facie evidence, not of their similarity, but of 

their difference of age ; and holding as he did the doctrine of single specific centers, 

the conclusion was as legitimate as any other; for the two districts must have been 

occupied by migration from one of the two, or from an intermediate spot, and the 

chances against exact coincidence of migration and of imbedding are infinite.

In point of fact, however, whether the hypothesis of single or of multiple specific 

centers be adopted, similarity of organic contents can not possibly afford any proof 

of the synchrony of the deposits which contain them; on the contrary, it is deinonstrably compatible with the lapse of the most prodigious intervals of time, and with 

interposition of vast changes in the organic and inorganic worlds, between the epochs 

in which such deposits were formed. 1 * * *

There seems, then, no escape from the admission that neither physical geology nor 

paleontology possesses any method by which the absolute synchronism of two strata 

can be demonstrated. All that geology can prove is local order of succession. It is 

mathematically certain that, in any given vertical linear section of an undisturbed 

series of sedimentary deposits, the bed which lies lowest is the oldest. In any other 

vertical linear section of the same series, of course, corresponding beds will qccur in a 

a similar order; but however great may be the probability, no man cau say with absolute certainty that the beds in the two sections were synchronously deposited. For 

areas of moderate extent, it is doubtless true that no practical evil is likely to result 

from assuming the corresponding beds to be synchronous or strictly contemporaneous ; 

and there are multitudes of accessory circumstances which may fully justify the 

assumption of such synchrony. But the moment the geologist has to deal with large 

areas or with completely separated deposits, then the mischief of confounding that 

"Homotaxis" or "similarity of arrangement," which can be demonstrated, with 

" synchrony " or " identity of date," for which there is not a shadow of proof, under 

the one common term of " contemporaneity " becomes incalculable, and proves the 

constant source of gratuitous speculations.3

1 Quart. Jonr. Geol. Soc., London, vol. 18, 1862, p. xlv.

*0p. cit.,p. xlvi. i
428 THE CAMBRIAN. [BULL. 81.

In this connection the student should read Mr. J. E. Marr's paper on 

Hoinotaxis.1

Percentage of species. This method of paleontologic correlation was 

employed by Sir Charles Lyell. He found a certain percentage of 

species identical with living forms in one horizon, the Eocene; a larger 

percentage in the Miocene, and a still larger one in the Pliocene. He 

then concluded the Eocene represented the oldest and the Pliocene the 

latest deposit. He thus classified the formations and gave an indirect 

method for their correlation in different areas. It is not capable of 

application where all the members of a fauna are extinct.

III. LITTIOLOGIC CHARACTER.

Lithologic character has very little value in establishing correlations, 

when comparing formations outside of limited areas. The constituents 

of a rock may differ in their chemical and mechanical condition in a 

stratum that is proved by other evidences to be continuous. In some 

instances lithologic characters may be of value, especially in areas 

where the stratigraphic sequence of the beds is known and paleontologic evidence is lacking. Dr. E. D. Irviug used the method successfully among the pre-Cambrian rocks of the Lake Superior region, and 

says of it:

Its value in tracing formations from point to point can hardly be overestimated, 

heing as great as that of paleoutological evidence and, in my judgment, of much the 

same nature. As we trace formations and their minor subdivisions from place to 

place we must of course constantly check lithological evidence by stratigraphy. As 

we pass from one extremity of the field to the other, changes in lithological characters of course come in, and these changes might lead to unsafe conclusions were we to 

compare strata! successions too distantly removed from one another; but when we 

work from point to point such changes are detected aa they gradually appear, and 

are provided for.2

An illustration of the value of the method is shown bv the correlations made by the brothers Eoger's3 in Virginia and Pennsylvania, where 

they correlated the quartzites, shales, and limestones by their lithologic characters along an extent of several hundred miles. When, 

however, they came to carry this correlation without that area of sedimentation, the inadequacy of the method is shown by the fact they 

correlated the Lower Cambrian quartzite with the Upper Cambrian 

quartzite about the Adirondacks of New York. A still more striking 

illustration of erroneous correlation by this method is that made by 

Prof. ]$". H. Winchell 4 in correlating, as members of one formation, the

1 Proc. Cambridge Phil. Soc., vol. G, 1887, pp. 74-82.

2 Seventh Aun. Kep. TJ. S. Geol. Survey, 1885-'86,1888, pp. 378, 379.

3 A system of classification and nomenclature of the Paleozoic rocks of the United States, with an 

account of their distribution, more particularly iu the Appalachian mountain chain. Am. Jour. Sci., 

vol.47,1844, p. 112.

4 The crystalline rocks of Minnesota. General report of progress made in the study of their field 

relations. Statement of problems yet to be solved. Geol. and Nat. Hist. Survey of Minu., 17th Ann. 

Kep. for 1888,1889, p. 49.
CORRELATION. . 429

Lower Cambrian quartzite of the western slopes of the Green Mountains, the Upper Cambrian Potsdam sandstone of New York, the pre. 

Ciiinbriari Sioux quartzites of Minnesota, the pre-Cambrian Bsmiboo 

quartzite of Wisconsin, and the pre-Cainbriau quartzite of the Keweeiiawan series of Lake Superior.

Lithologic character is often of great value within limited areas and 

where the formation can be practically traced from place to place. As 

this can rarely be done, it is best to seek other data and to combine 

with the lithologic, the strati graphic and paleoutologic evidence, if it is 

possible to obtain any.

IV. UNCONFOUMITY.

Of all the data of correlation that of unconformity of the formation 

correlated, withitssuperjacentor subjacent formation, would appear at 

first sight to be the most unreliable. In most instances it is, but where 

coin bined with other data it has a certai n value. We find it used in the 

earliest correlations made of the Potsdam sandstone of New York, with 

the basal sandstone all along the Appalachian Range south through 

New Jersey, Pennsylvania, Maryland, Virginia, Tennessee, Georgia, and 

Alabama. It is also used in the correlations made between the Potsdam sandstone of New York and the sandstone of the south shore of 

Lake Superior, and the fossiliferous sandstones of Wisconsin, Iowa, 

and Minnesota, that were correlated with the Potsdam sandstone by 

Messrs. Owen, Hall, and later observers. In fact, it is implied in 

nearly all the references of strata to the Potsdam horizon in other localties than that of the typical area about the Adirondack Mountains of 

New York. It was not, however, until the appearance of Prof; It. 1). Ir ving's essay on the classification of the earlier Cambrian and pre-Cambrian formations 1 that full significance was given to the value of unconformities in correlation.

The problem is presented by Dr. Irviug as follows:

(1) To determine upon the grander divisions (groups) to be ma de in classifying the 

rocks independently of their relations to the general geological column ; (2) to extend these divisions to other portions of the same geological basins; and (3) to correlate these divisions with those of different and distant geological regions. This is 

the problem which presents itself in the Lake Superior region, at the base of the 

Grand Cailoii of the Colorado, in central Texas, Newfoundland, and in other portions of North America.

In any attempt to solve such a problem we can make use of one or more of three 

kinds of characteristics in the formations involved, viss: (1) their paleontologies! 

characteristics, (2) their lithological characteristics, and (3) their mutual structural 

relations. 2

Under the third title, u their mutual structural relations," he considers unconformity as a basis for classification 3 discussing the general 

nature and significance of conformities and the distinguishing characters of true unconformities. A description is given of the Potsdam*

1 Seventb Aim. Kep. U. S. Gool. Surv., 1885-'86,1888. 

3 Op. cit., p. 371. 30p. cit., p. 390.
430 THE CAMBRIAN. [BULL. 81.

Huroiiian unconformity on the north shore of Lake Huron, the Potsdam-Keweenaw unconformity, the Laurentian-Horoniau unconformity 

and others of the Lake Superior region. This is followed by a section 

on the use of unconformities in classification.1 In this the use of unconformities in defining the grander groups of strata and in correlating 

the formations of a single geologic basin are discussed. Under the 

first, he says:

Returning to our problem as originally stated, we have next to consider how far 

unconformaties may be made use of in defining the grander groups of strata in a 

region in which the succession of these strata has been determined. Further argument than that already given in discussing the nature and kinds of unconformity is 

hardly necessary to show that genuine unconformities, indicative of great lapses of 

time between the periods in which the strata on either side of the break in each 

case were respectively made, are of prime value and importance in determining the 

limits of the grander groups of the geological formations, whatever use we may 

make of paleontological and lithological characters in determining subordinate 

divisions. Such structures as the greater ones of the true unconformities, above considered, indicate lapses of time great enough to cover extended periods of mountainmaking, always a slow process, and also great periods of denudation or exposure to 

the atmospheric agencies. It is hardly possible for us to compare such time gaps 

with the time necessary for the formation of definite thicknesses of strata, but the 

thicknesses of strata corresponding to such breaks must surely always be very great.

If we take for instance the gap indicated by the relations of the Potsdam sandstone to the ancient gneissic formation of the northwest, as above illustrated by a 

number of examples, we find "that it was long enough to cover not merely one period 

of rock alteration, orographic movement, and land surface exposure, but three such 

periods, between which were times long enough for the accumulation of thicknesses of 

strata aggregating over 60,000 feet, a thickness exceeding that of the entire Paleozoic 

series in its greatest development in the Appalachian region. It is true that a portion 

of this 60,000 feet is made up of volcanic materials, chiefly lava flows. The accumulation of such materials may, it is true, have been more rapid than is the case with 

ordinary fragmental deposits ; but the accumulation of such a mass of eruptive 

material must have occupied at least a considerable lapse of time; while more than 

one-half of the 60,000 feet, or an amount approximating the maximum Paleozoic accumulations in the Appalachian region, is made up of genuine detrital deposits. When 

we consider that in addition to the time necessary for the accumulation of this mass 

of sediment there intervened between the Potsdam and the gneisses three periods of 

rock alteration, mountain-making, and complete mountain removal, it becomes plain 

that the time gap indicated by this unconformity must have exceeded the entire Paleozoic era. More probably, indeed, it equalled all later geological time. Each one of 

the three unconformities mentioned must of course have required a shorter period 

than this greater gap, but in each case the relations of the several formations are 

such as to indicate periods of time only comparable to the periods necessary for 

the accumulation of one of the great geological groups.2

The use of unconformities in correlating the formations of a single 

geologic basin, where the exposures of the formations are not continuous, is illustrated by a tabulation showing the general succession of 

formations in various districts from the northern end of Lake Huron to 

Dakota and from central Wisconsin to the north shore of Lake Superior. 

This table shows that in various localities there is a great unconformity

' Op. Cit., p. 438. * Op. cit., pp. 438,439.
WALCOTT.] CORRELATION. 431

between the Laurentian and the Huronian, between the Huronian and 

the Keweenawan, where the two series of rocks are present, and between the Keweenawan and the Cambrian if these two occur in the same 

area.

He next takes up the use of unconformities in establishing general 

relations. Under this heading we quote as follows:

Having established the general order of succession and the grander groups of the 

strata for a given geological province, the question which arises next'in order is how 

to correlate these divisions with those of other geological provinces, and more particularly with the established divisions of the general geological column.

It will take but little consideration of the causes which have been at work in the 

production of such unconformities as have been above cited to make us realize that 

such breaks as these must be widespread in their influence. Great unconformities, 

in whicli the strata below the unconformity have been subjected to folding, mark 

periods of orograpbic movements which will, in general, have been extensive somewhat in proportion to the intensity of the folding process. 1

It is well known, indeed, that some of the greater physical breaks in the strata of 

one continent may have their parallels among the strata of another continent. The 

interruption between the Paleozoic and the Mesozoic is intercontinental, if not world 

wide. Equally extensive is the great break between the Mesozpic and the Cenozoic. 

Each of these physical breaks corresponds to an immense change in life conditions. 

But, if we may judge from structural relations, from the amount of intervening 

denudation, and from the rank already attained by the life of the lowest of the fossiliforous Cambrian formations, neither of these great breaks corresponds in length of 

time interval to the break between the lowest of the distinctly fossiliferous formations and the youngest of those beneath it.2

The great structural breaks furnish, at times at least, a more trustworthy guide. 

If, for instance, we make a comparison of the succession of Cambrian and preCambrian strata in the Lake Superior region with the succession revealed in the 

depths of the Grand Canon of the Colorado, we find some singular correspondences 

between the structural breaks of the two successions. In each one of these regions 

the Potsdam sandstone is strongly characterized by its well known fauna. In each 

region the sandstone traverses the edges of a gently bowed but deeply denuded 

formation composed of a great thickness of detrital and eruptive materials. Below 

these formations in each region, and separated from them in each ca«e by one of the 

strongest of unconformities, is a great quartzitic series, while below this series 

again in the Lake Superior region, and separated from it by still another of the most 

notable of unconformities, is the great Laurentian gueissic series. That this series 

also exists in the base of the Grand Cafiori we have good reason to believe.

Such a striking similarity in succession as this certainly most strongly suggests the 

conclusions that the physical breaks of the two regions were coincident in point of 

time (that is, that the mountain-making movement which preceded the deposition 

of the Potsdam sandstone of the Lake Superior country corresponded with that which 

preceded the Tonto sandstone of the Grand Cafion region); that the mountain-making periods preceding the deposition of the Grand Canon series of the Grand Canon 

district and of the Keweenaw series of the Lake Superior region were equally syn. 

chrouous; and, finally, that the Grand Cation series is, in general, the equivalent of 

the Keweeuaw series, while the pro-Grand Canon rocks are the equivalent of the 

Lake. Superior Huronian.

Of course such correlations as these should be made, for the present at least, somewhat provisionally; but, on the other hand, they must be taken as of much greater 

value than correlations between distant formations established on feeble fossil 

evidence.3

' Op. cit., p. 443, * Op. cit., p. 444. » Qp. cit., p. 445.
432 THE CAMBRIAN. [BULL.8L

The question is asked, is the term Cambrian to stop at the first 

unconformity below the Potsdam sandstone ? Is it to extend to the 

second of those uncoinforiaities, or to the third f Or is it to include? 

finally, the lowest of the formations of the region?

He makes the following reply to these questions:

All these usages of the term have been made. In taxonomical value the term Cambrian is designed, of course, to correspond to the terms Upper Silurian, Lower Silurian, 

Devonian, Carboniferous, etc., which terms are based primarily upon the general continuity for each one of the periods to which they correspond of similar life conditions. 

In no case, however, has one of these terms been allowed to span any such unconformtible break as the least of those beneath the Potsdam sandstone of the Lake Superior 

region. Minor breaks in the succession have been included within a single one of 

these geological groups because although in every case of a physical break, even the 

smallest, a corresponding break in life-succession is found there have been found on 

both sides of the break fully developed faunas of general similarity in characters; 

but no great break in the succession such as those with which we are now concerned 

has ever yet been found to be spanned by a continuity of forms. The conclusion, 

therefore, seems inevitable that we should not extend the term Cambrian over any 

such break, at least until there shall have been found closely corresponding faunas 

on opposite sides of the interval. Were such faunas to be discovered the greatness 

of the unrecorded interval would still remain, and we should have indicated only a 

singularly long continuance of similar life-conditions. Even then the question might 

arise as to whether continuity of life-conditions should outweigh the great lapse of 

time indicated by the physical hiatus. 1

Finally Dr. Irviiig states that

The structural breaks called unconformities are properly used in classification 

(1) To mark the boundaries of the rock groups of a given region.

(2) To aid in establishing correlations between the formations of different parts of a single geological basin.

(3) To aid in the establishment of correlations between the groups of regions distantly 

removed from one another; but caution is needed in attempting such correlations hi 

proportion as the distances between the regions compared grow greater.

They are improperly ignored:

(1) IPlien the evidence they offer as to separateness is allowed to be overborne by anything 

but the most complete and weighty of paleontological evidence.8

V. MISCELLANEOUS.

Homogeny. A method of correlation that has frequently been used 

has recently been named by Mr. W J McGee " Homogeny " or correlation by community of genesis.3 Mr. McGee defines it as follows:

The method of correlation devised to systematize the structure of the Coastal Plain 

combines the desirable features of the older methods, and adds thereto the interpretation of the products of the several physical processes operating upon the earth's 

exterior.4

The older methods mentioned are those of strati graphic continuity, 

lithologic correlation or correlation by petrography, and paleontologic

1 Op. cit, p. 446. s Am. .Tour, Sci., 3d ser., vol. 40, 1890, pp. 36-41. 

3 Op. cit., p. 448. « Op. cit., p. 36.
WALCOTT.J COREELATION. 433

correlation. He considers that " the method involves a yet broader 

conspectus of phenomena and principles than the paleoutologic method; 

for in its application it is necessary mentally to restore the various 

physical and biotic conditions of the past, just as paleontology vivifies 

the fossils of past ages." Again: 4

In discriminating the general and local genetic conditions it is necessary to ascertain the relations between each formation and its newer and older neighbors, and to 

interpret the record of each unconformity in terms of continent growth. By this 

means the different parts of a formation may be found to represent not only general 

community of genesis but community of beginning and ending; in short, entire community of structural relation. Each part of the formation then records in similar 

terms the same episode in. continent building and world growth.

So, when a coastal plain formation is found to represent general community of 

genesis and structural relation in its various parts it is considered homogeuic, and 

accepted as a record of an episode in geologic history. The parts may or may not be 

homotaxial; one part may be slightly older than another part; but in a general way 

it is contemporaneous throughout. Hoinogeiiy implies not only equivalence but 

synchrony.

The principles of horaogenic correlation have long been used in the 

correlations of formations by geologists. An illustration of this is the 

correlations that have been made of the Potsdam sandstones of New 

York with those of the Mississippi Valley, the eastern slope of the 

Kocky Mountains, the islands of Texas and Missouri, and the valley of 

the St. Lawrence. In these correlations to subjacent arid superjacent 

formations, stratigraphic continuity, lithologic or petrographic resemblance, and similarity of organic remains have all been used.

Under the definition of homogeny, that is, correlation by community of 

genesis, decided errors must necessarily occur unless checked by paleontologic data. An illustration of this is the correlation of the Potsdam 

sandstone of the Adirondack Mountains of New York with the 4 ' Granular Quartz" of western New England and southeastern Pennsylvania, 

and the Chilhovvee sandstone of Tennessee. These sandstones are lithologically alike, they were accumulated along a coast line, their petrographic characters are the same, and the action of the waves upon and 

the distribution by tidal currents of the sediments originating from 

similar crystalline rocks all point to a community of origin; in fact, 

they did originate in the same manner. They have been correlated 

upon the characters mentioned for upwards of 40 years, but the study 

of the fossil remains shows they are not equivalent or synchronous. 

One represents the basal beds of the Cambrian system and the other 

the Potsdam sandstone or the closing deposits of Cambrian time in the 

same area. I think that after we have fully proven to our satisfaction 

the similarity of origin or the community of genesis we must still rely 

upon paleontologic data for the final determination of geologic equivalence. For the determination of synchrony, except in a limited area, 

there is little hope for satisfactory conclusions by any method yet devised.

4 Op. cit.,pp.38, 39.

Bull. 81 28
434 THE CAMBRIAN. [BULL 81.

Topographic features in correlation. Topographic features may indicate relative geologic age in the discussion of the later formations; but 

in dealing with the Lower Paleozoic it has thus far been found to be 

impossible to obtain the evidence of newer or older topographic features 

that are of value. Mr. Gr. K. Gilbert has used it successfully in discussing the age of the Equus fauna of Lakes Mono and Lahonton of California and Nevada.1

1 U. S. lieol. Survey, Monograph, vol. 1,1890, pp. 393-402.
INDEX.

Acadian series, J. W. Dawson on. 

definition of...................

Georgia - .................

formations correlated with. .=.

Page. 

62 

248 

303 

360 

Acadian slates of Alabama .............. 305-306

Adams, C. B., on quartz rock of Vermont. 95 

on red sandrook ...................97,250-251

on Taconio elate ..................*.. 99

fossils of red sand rock .............. 150

Adirondack subprovince, paleontology of 229-232 

Cambrian rocks of................... 341-347

sediments of......................... 347

problems for investigation in ........ 381

Agassiz, A., on Lake Superior sandstone. 195 

Agassiz, L,, on rocks of Braintreo, Massachusetts .............................. 74

on correlation by fossils.............. 419-420

Ami and Sowter, fossils from Quebec.... 232

Alabama, M. Tourney, on rocks of....... 146

B. A.Smith,on rocks of.............. 346-148

Cambrian rocks of........... 146-148,305-308

Antelope Spring, Utah, section........... 320

compared with other sections........ 320

Anse an Loup, 1', Newfoundland, section.253-254 

Appalachian province, definition of...... 91-274

Cambrian rocks of.............91-148,274-312

Archteocyathus, remarks on............. 319

Argentine Republic, Cambrian rocks of. 379 

Arizona, Cambrian rooks of......219-221,356, 357

J. S. Newberry on rocks of........... 219-220

J. W. Powell, on rocks of............. 220-221

G.K. Gilbert, on rookn of ............ 220

A. E. Marvine, on rocks of............ 220-221

C. A. "White, on fossils of............. 221

C. D. Walcott, on rocks of............ -221

paleontology of....................... 235

problems for investigation in ........ . 385

Atlantic Coast province, definition of.... 50,253

Cambrian rooks of................... 50-78

paleontology of...................... 78-90

summary of knowledge of Cambrian

rooks of............._.......... 253-274

sediments of......................... 353

fauna of...................... I....... 370

physical characters of strata ........ 273-274

Atlantic Coast and Rocky Mountain

province......................... 386-387

Atlantic Coast series, J. "W. Dawson on.. 66 

Atlantic Coast series of America and

Wales ........................373,374-375

Page.

Attleborongh, Massachusetts, E. Hitchcock on limestone in............. 73

T.S.Hunton rocks at ............... 73

Auroral limestone, T. S. Hunt on......... 327-128

An Sable Chasm, New York, section..... 343 344

Australia, Cambrian rocks of ............ 378-37!»

Avalon and Fortune Bay, Newfoundland,

section........................... 257-258

B.

Bailey, L. "W., on rooks of Hew Brunswick............................. 61,04

Bakewell, R., on use of fossils in correlation.............................. 397-398

Balcony Falls, Virginia, rocks of......... 136

section at.....................293-294,297,298

Bannock Range, Idaho, section........... 322

Bar Harbor, Maine, rocks at.............. 68

Barrande, J., on fossils from Braintree,

Massachusetts................... 75,88

on fossils from Georgia slate......... 99

primordial fauna of Texas ........... 234

definition of primordial.............. 243

iise of fossils in correlation........... 416-417

BayfielJ, H. W., on rocks of Straits of

Belle Isle ........................ 50

on Lake Superior sandstone.......... 188, 252

Beecher & Hall, on Mohawk Valley...... 207

Belle Isle shale .......................... 50,51

Belle Isle Straits, rocks of............... 102,104

Bell, Robert, on rocks of Hudson Bay.... 122

Bennington, Vermont, section............ 276

Big Cotton wood Caftan, Utah, section.... 157-158,

159-160

Big Horn Mountain range, Montana, section .............................. 825-326

Bigsby, J. J., on rocks near Quebec ...... 114

on Montmorenci Falls ............... lie

on rooks of the St. Lawrence ........ 116

on Lake Superior saucistone ......... 188, 252

on Potsdam, of New York ........... 208

correlations of...................... 395-390

comparison of rocks of New York

and "Wales....................... 418-419

Billings, E., on red sandrock ............. 97

on Georgia slate ..................... 102

on "Winooski mar bio................. 103-104

on Point Levis fossils......... 116-117,150,151

on correlation of faunas ............. 150

on fossils from Potsdam group of

Vermont......................... 150

435
436 INDEX.

Page. 

Billings, E. Continued.

on fossils from red sandrock......... 150

on fossils in correlation.............. 406-407

Black Hills, Dakota, E. James on rocks of 214 

H. Engelmann on rocks of............ 214

Meek & Hayden, on rocks of........ 215

F. V. Hayden, on rocks of............ 215-216

N. H. Winchell.on rocks of........... 216

K. P. Whitfleld, on fossils of ......... 216

H. Newton, on rocks of............... 216

F. R. Carpenter on................... 216

fossils of..........................233, 234,348

rocks of...... ....................... 347-349

Bohemia, Cambrian rocks of ............. 275

Bonne Bay, Newfoundland, section ....61,255-256

fossils from ...... .... ................ 256

Boston and vicinity, J. W. "Webster on

rocks of.......................... 72

E, Hitchcock, on rocks of............ 73-75

Bow River series .....................164,326-327

Bradley F. H., on rocks of North Carolina.............................. 138-139

classification of...................... 143-144

011 rocks of Utah .................... 156,157

on rocks of Idaho.................... 161

on rocks of Wyoming................ 212

on fossils from the Adirondacks...... 231

correlations by....................... 411-412

Brain tree, Massachusetts, L. Agassiz on

rocksat ............. ....... 74

W. B. Rogers, on rocks at............ 73,74

I. Lea, on rocks at.................... 74

C. T. Jackson, on rocks at............ 74

J.Barraude, on fossils from..... ..75,88-89

N. S. Shaler, on rocks at.............. 75

T.S. Hunt, on rocks at. ............ 75-76

W. W. Dodge, on rocks at, cited...... 75

W. O. Crosby, on rocks at............ 76,77-78

J. Green, on fossils from ............. 88

W. B. Kogers, on fossils from......... 88

C. T. Jackson, on fossils from ........ 89

A. Ordway, on fossils from........... 89

W. W. Dodge, on fossils from ........ 89

U. P. Whitfield, on fossils from....... 89

C. D. Walcott, on fossils from ......... 89

Braintree quarry, Massachusetts, M. E. 

Wadsworth, on........................ 271

Bretonian, definition of.................. 247

Brigus, Newfoundland, fossils of......... 55

Brigus Head, Newfoundland, section..... 260

British Columbia, G. M. Dawson on rocks

of.............................163,164,165

R. G. McConnell on rocks of......... 164

Broadhead, G. C., on rocks of Missouri.. .200-201,

340-341 

Brogger, "W. C., on Prospect Mountain

fauna ................................ 314

Brooks and Pumpelly, on Lake Superior

sandstone.................... .... 196

Buokley, S.B., on rocks of Texas........ 218

Burnet County, Texas, section............ 354-355

C.

Calciferous sandrock in "Wisconsin....... 172,177

Calvin, S., on well at "Washington, Iowa.. 188

Page. 

Cambrian continent...................364-365,386

Cambrian faunas, order of succession of,

in America....................... 361

Cambrian, base of........................ 302

sedimentation of...... ....... 362-363,363-369

summit of............................ 362-363

faunas of................ ............ 369

subdivision of.... .................... 370-373

sediments of...... .................... 385-H86

limits of.................._......... 388-389

Cambrian time, geographic areas in....49,368-369

Cambrian group, delimitation of.......... 17

divisions of................ ........49,389-390

A.R.C.Selwyn on...... ............. 119

definition of, by Sedgwick and Murchison............................ 237-239

divisions of, by A.Sedgwick ......... 239

use of in America.......... ........... 241

where separated from Silurian...... 241,363

sediments of in eastern Massachusetts ............................... 272

synopsis of.... ....................... 359

formations of......................... 359-360

Cambrian and Tacouic, T. S. Hunt on.... 108

useof..... .. . ................ 388

Cambric, used by P. Frazer............... 131

Camp Baker, Little Belt Mountains (Montana) section........ . ......... 325

Campbell, J., Nova Scotia gold field...... 57

Campbell,H. D., on rocks in Virginia.... 137

Campbell, J.L., on rocks of Virginia...... 135,136

Campbell, J. L. and H. D., on rocks of Virginia................ ............. 136

Canada, geologic map of................59,119-120

"W. E. Logan, on rocks of............. 207-208

Alexander Murray, on rocks of...... 208

problems for investigation in.... .... 382

Canada Bay, Newfoundland, section.. 257,273 

Canadian extension of the northern Appalachian district, Cambrian rocks 

of................ .........114-122,285-287

Canadian extension of Adirondack subprovince, Cambrian rocks of. 207-208 

Canadian extension of Kooky Mountain

province, Cambrian rocks of..... 326-327

Canadian extension of upper Mississippi

province, Cambrian rocks of..... 334

Cape Breton, G. F. Matthew, on rooks of. 55 

H. Fletcher on rooks of........... 63,266-267

G. F. Matthew, on fauna of.......... 65, 84,

Caradoc sandstone, position of.......... 239

Carpenter, F. R., on Black Hills..... 216,348-349

Castle Mountain group.............. 164,326,327

Chamberlin, T. C., on Potsdam sandstone

of Wisconsin..................... 179

work of, in Wisconsin ............. 179,180

on Lake Superior sandstone...... 198,338, 339

on fossils from Wisconsin ....... 226,227-228

Chapman,E. J., on Climactichnites..... 231

Chateaugay Chasm, New York, section... 342-343 

Cherokee slates described............... 138

Chester, F. D., on Potsdam of Delaware.. 123 

Chikis quartzite, P. Frazer on . ...... 129

description of........................ 288,289

Chilhowee,definition of. .............. 251
INDEX. 437

Chilhowee sandstone, J. M. Saffordon... 300-301 

China, Cambrian rocks of................ 377-378

Cambrian fauna of................... 377-378

Choccolocco.............................. 247

Clarksburg Mountain, Massachusetts,

section........................... 275-276

Classification, geologic................... 17

Clemson, T.G., sections in Virginia...... 133

Colorado,Cambrian rocks of.... 209-210,351-354

F. V. Hayden on rocks of............ 209

A. C.Peale on rocks of.............. 209-210

Arnold Hague on rocks of........... 210

S.F.Eminons on rocks of............ 210

fossils from Quandary Creek, in...... 210,234

synopsis of Potsdam rocks of....... 353

problems for investigations in....... 384

Colorado River section................... 220

Comstock, T. B., on rocks of Wyoming... 212-213 

division of Cambrian of Texas ... 219,355-356 

definition of Katemcy................ 246

of Riley.............................. 246

of Hickory........................... 246

on rocks of Wind Mountains....... 349

Connasauga, definition of................ 246

Conrad, T, A., formations of New

York..........................203,204,205

on fossils of Adirondacks ............ 229

on use of fossils in correlations .. _.. 399-401

Cook, G. H.,on Potsdam in New Jersey.. 122--123

on Green Pond Mountain rocks...... 123

Coosa, definition of......... .............. 247

Coosashales, fossils from................. 305

E. A. Smith on ....................... 308

Coosa Valley, Alabama, rocks of......... 308

Cornwall iron mines, T. S. Hunt on....... 127

Correlation of North American and British strata ........................ 417-418

Correlation, methods of.................. 421-434

superposition in... ................ 421-422

use of organic remains in ............ 422-428

life zones in.......................... 424-425

stage of evolution in...... ....... 425-426

life history in........................ 426-427

contemporaneity and ho mo taxis in... 427 

percentage of species in ............. 428

lithologic character in ............... 428-429

unconformity in...................... 429-432

homogeny in......................... 432-433

topographic features in .............. 434

Crosby, W. 0., on rocks at Frenchman's

Bay,Maine...................... 68-69

on rocks at Braintree, Massachusetts.76,77-78 

on Cambrian rocks of eastern Massachusetts ............._......... 268-270

on rocks of Nahant....__.......... 271

D.

Dakota, Cambrian rocks of....... 214-216,347-349

Dale, T. Nelson, work of, in Vermont..... 283

Dames, W., on fauna of Cambrian of

China............................ 377

Dana, J. D., on granular quartz of Massachusetts ......................... 106-107

on red saudrock ..................... 107

Page. 

Dana, J.D. Continued.

on A. Wing's discoveries in Vermont 107 

quartzitos of eastern New York ..... 109

principles of correlations ............ 407-408

Dana, J. F. and S. L.,on roclui of eastern

Massachusetts................... 72

Dana and Grinuell on rocks of Little Belt

Mountains, Montana ............ 1C2

Daniels, Edward, fossils from Black Kiver,

Wisconsin ....................... 223

Dawson, G. M., classification of the Cambrian in Canada.................. 67,123

onrocksof British Columbia .....163-164,165

on Selkirk range, British Columbia... 165

Dawson, J. W., on Atlantic coast series.. 56, 59

Nova Scotia metamorphic slate ...... 57

on rocks of New Brunswick ......... 60

on strata at St. John, Now Brunswick 61 

on A cadian series ................... 62

on fossil tracks from Canada......... 231

on Cambrian......................... 241

definition of Acadian ................ 248

Delaware, F. D. Chester on Potsdam of... 123,288 

De la Beche, on use of organic remains... 398 

Devine, T., trilobites of Point Levi...... 151

Dewey, Chester, work of, in Massachusetts............................. 93-93

Diamond Creek, Arizona, section ; ....... 219

Dikellocophalon ..........__........... 222

Dodge, W. W., on fossils from Braiutree. 89 

on rocks at Braintreo, cited .......... 75

Dutchcss County, New York, Mathor,

Smock, and Dwight on rocks of.. 111-112 

granular quartz iu ................... 276

rocks of.............................. 283-284

Dutton, C. A., on Tonto of Arizona...... 221

Dwigbt, W^B.,011 the rocks of Dutchess

County, New York .............. Ill

fossils from Poughkeopsie, New York 1.53 

on rocks of New York................ 283-284

Eastern border or Adirondack sub-province, definition of................ 201

Cambrian rocks of................... 201-208

Eastern sandstone, description of..... 197,335-336

definition of.......................... 253

Eaton, Amos, nomenclature of........... 92-93

on rocks of Vermont................. 98

definition of granular quartz......... 2f>0

correlations of................... .392-395,399

on use of organic remains ........... 394

East Rutland, Vermont, limestones of ... 276 

Elliott, J. B., on rocks of Tennessee... 144 

Ells, K. W., on Cambrian rocks of provincoof Quebec................... 120 321

on rocks near Quebec................ 285 286

Emmetsburg, Iowa, section .............. 187

Eiumons, E., classification of ............ 94,403

on granular quarte .................. 94-95

on Eed Sandrock .................... 96

on Taconic system ............._.. 98

on Montmoreuci Falls ............... 114

fossils of Tacouic system ............ 148-149

on Potsdam sandstone....202-203,204,205,20G
438 INDEX.

Page. 

Eramons, E. Continued.

on fossils of Adiiondacks............ 229,231

on Cambrian in America ............ 240

definition of Taconic ................ 242-243

definition of Potsdam................ 244

Eramons, S. F., Big Cottonwood Cation

section ......._................ 157-158

tabulation of rocks of Colorado...... 210

on rocks of Colorado................. 351-352

Endlich, F. M., on rocks of "Wyoming.... 213

Engeluiaun, H., on rocks of Black Hills.. 214 

English and American classifications compared ............................ 376

Eatoria, Cambrian rooks of.............. 375

Etheridge, R., on Cambrian of Australia. 378-379 

Eureka District, Nevada, fossils from.... 167-169

section............................... 313

Fall River, Massachusetts, W. B. Rogers,

on rocks at....................... 75

Ferrier, "VV. F., on fossil track from Adirondacks ........................ 232

Fitch, Asa, on Taconic slate and sandstone ......................._.. 98-99

on fossils of New York...........148,149-150

Fletcher, H., on rocks of Cape Breton. .63,266-267 

Foerste, A. F., on rocks ot Nahant, Massachusetts .. ................... 78

on fossils from Nahant, Massachusetts............................. 90

on rocks of eastern Massachusetts... ' 271 

Foutaine, W. M., on rocks of Virginia....

135-137,291-292-297

Ford, S. W., on rocks at T roy, New York. 106 

iossils from Troy, New York ........ 152

Foster and Whitney, on Lake Superior

sandstone.....................lffl-192,193

table of rocks ..__........_....... 192

France, Cambrian rocks of............... 375

Frazer, P., on South Mountain rocks..... 128

on Chikis quartzite.................. 129

primal quartzites.................... 129

on Hell am quartzite or Potsdam sandstone ............................. 131

on rocks of Pennsylvania............ 289

Frenchman's Bay, Maine, "W. 0. Crosby

on rocks of....................... 68-69

G.

Gallatin City, Montana,section. ...... 162

Gallatin River, Montana, section..... 162-163,324

fauna of.............................. 325

Gasp6 peninsula, A. P. Low on rocks of.. 120 

Geiger and Keith on rocks at Harper's

Ferry.....................137,138, 291-292

Geikie, A., on Cambrian rocks of Scotland. 376

on Cambrian rocks of Ireland........ 377

Geographic areas in Cambrian time... .49,368-3G9

Geologic classification.................... 17

Geologic nomenclature, general considerations on.......................... 230-237

Georgia, G. White on rocks of............ 144,145

Page.

Georgia Continued.

Cambrian rocks of ........... 144-146, 303-305

G. Little on rocks of................. 145

J. T. Henderson on rocks of......... 145

A. R. McCutchen on rocks in........ 145-140

paleontology of...................... 155

Georgia and Alabama, problems for investigation in................... .... 383-384

Georgia, Vermont, C. D. Walcott on the

Cambrian of..................... 110

section at.................277, 278, 279, 280,261

Georgia formation, definition of.......... 248,250

J. Barrande on fossils of............. 99

Georgia group, C. H. Hitchcock on...... 101

Georgian,formations correlated with.... 360

Georgia slates, description of ............ 98-113

E. Billings on........................ 102

J. Marcou on......................... 103

C.-H. Hitchcock on.................. 106

character of.......................... 278

Gesner, A., on rocks of New Brunswick.. 59 

on rocks of Nova Scotia.............. 56

Gilbert, G. K, work of in Nevada........ 156

on rocks of Arizona.................. 220

definition of Touto................... 245

correlations by....................... 412

on topographic features in correlation .............................. 434

Grand Canon, Arizona, section .......... 563

Granular quartz, description of.......... 91-96

E. Emmons on ....................... 94,95

J.Hall on............................ 100

C. H.Hitchcock on................... 106

J,D.Dauaon ........................ 100,107

C.D. Walcott on ..................... 112

N.H.Winchell on.................... 186,187

definition of.......................... 250

age of................................ 250

distribution of................... 275,276,372

characters of......................... 275-277

Great Bell Isle, Newfoundland, fossils

of.............................153, 259, 261

section............................... 258,259

Green, Jacob, on Paradoxides............ 88

Green Pond Mountain rocks, G. H. Cook

on................................ 123

H.

Hague, Arnold, on rocks of Nevada . .158,159, ICO 

on rocks of Colorado ................. 210

on the age of rocks of Laraniie Hill,

Wyoming........................ 212,350

definition of Hamburg ............... 246

definition of Secret Canon........... 246

definition of Prospect........... . 252

Hall, O. E., on hydromica slates .......... 129

011 Potsdam «f New York............ 207

Hall, James,on fossils near Troy......... 99

on granular quartz................... 100

on fossils of Vermont ................ 100,102

on fossilsofNew York............... 149

on fossils from rod sandrock......... 149

on fossils of Hudson River group.... 149

on fossils of Quebec group ........... 149
INDEX. 439

Page. 

Hall, James Coatinned.

Olenellua proposed by................ 491

on rocks of Wisconsin ........... .173,175-178

on age of sandstone of Wisconsin and

Lake Superior................... 178

on Potsdam of Iowa.................. 187

on Potsdam sandstone of New York . 205 

on fossils of Wisconsin... .222,223, 224,225, 226

fossils of Adirondacks .......... .... 229, 232

on names of formations .............. 401

on use of fossils in correlation........ 401-403

methods of correlation............... 408,409

principles of correlation ............. 415,41fi

North America and European formations compared by ............... 416

Hall and Whitfleld on fossils of Nevada ........... r ..............159,166,167

on fossils from Adirondacks ......... 231

Hamburg, definition of................... 240

Hamburg limestone and shale, description

of................................ 315-317

fannaof.............................. 316,317

Harper's Ferrj, Virginia, Geiger and

Keith on rocka of................ 137,138

section............................... 291,292

Hartt, C. F., on St. John group........... 62

Hayden, F. V., on rocks of Montana...... 162

on rocks of Colorado................. 209

on rocks of Wyoming................ 211,212

on rocks of Black Hills .............. 215,216

Hayes, C.W., definition of Connasauga.. 246 

definition of Borne sandstone ........ 247

definition of Weisuer........... .. 251

section in Georgia ................... 304,305

Hellam quartzite ........................ 131

Hemmingford,Canada, section........... 343

Henderson, J. T.,on rocks of Georgia.... 145,303

Hickory,definition of.................... 246

Hicks, H., on Tremadoc group..... ... 242

on sediments of the Cambrian....... 373

on Cambrian of America and Wales. 375 

Highgate Springs, Vermont, section...... 279

Highland range, Nevada, fossils from .... 171

section............................... 317,318

fauna Of....................._.__. 318,319

Hind, H. Y., on Waverly gold district.... 57

on gold-bearing rocks of Nova Scotia. 58

on gneissoid series of Nova Scotia ... 58

Hitchcock, C. H., on Mount Desert, Maine 68

on rocks about Portland, Maine...... 68

on rocks of Maine.................... 69

classification of rocks in New Hampshire............................. 70,71

on classification of rocks in New England.............................. 72

on Georgia group................. 101,249,250

on the name Georgia................. 106

on rocks of Waterville, Maine........ 101

on quartz rock of Vermont. _...... 96

on foasils from Vermont ............. 99

on formations of Vermont............ 104

on Potsdam in Vermont.............. 105

on Winooski marble ................. 105

on granular quartz................... 106

Page. 

Hitchcock, C. H. Continued.

on red sandrock...................... 106

on Cambrian of Vermont............. 107

on sections in Vermont and New

Hampshire....................... 108

fossils of Potsdam group............. 223

proposes Potsdainic.................. 252

on mica-schist series of New Hampshire............................. 268

Hitchcock, E., on rocks at Attleborongh,

Massachusetts................... 73

on rocks of Boston and vicinity...... 73,75

Hiawassee River, rock s of................ 141

Homogeny, W. J. McGee on .............. 432,433

Homotaxis, T. H. Huxley on.............. 427

Hough, F. B., on Potsdam of New York .. 205,206 

Houghton, Douglass, on Lake Superior

sandstone........................ 188-190

table of rocks of Michigan........... 189

Howell, E. E., on rocks of Nevada ........ 156

Howley, J., on rocks of Newfoundland ... 53 

Hudson's Bay, Cambrian rocks on ....... 121,122

Hunt, T. S., on rocks at Attleborough,

Massachusetts................... 73

on rocks at Braintree, Massachusetts. 75-76 

on geology of Vermont............... 104

on Cambrian and Taconic............ 108

classification in Canada.............. 120

on Cornwall iron mines, Pennsylvania 127 

on Auroral limestone ................ 127,128

correlations of........... ........... 132,414

on Potsdam of Pennsylvania.......... 132

on Scolithus linearis ................. 132

on Lake Superior sandstone ......195,197,198

on Potsdam of New York ............ 206

on Cambrian, cited ................... 240

on Tacpnian.......................... 243

Huxley, T.H., on homotaxis...... ....... 427

Hy att, A., on fossils of Straits of Belle Isle 54 

on life history in correlation ......... 42C

Hydromica slates, C. E. Hall on .......... 129

T.

Idaho, 0. St. John on rocks of............ 161

F. H. Bradley on rocks of............. 161

A. C. Peale on rocks of ............... 161

Cambrian rocks of............ 161,162,320-323

Lower Paleozoic section ............. 323

sedimentation of..................... 328,329

India, Cambrian rocks of................. 378

d'luvilliers, ou Potsdam sandstone of

Pennsylvania.................... 130

on correlation of the Potsdam........ 404

Interior Continental Province, definition

of................................ 171,330

Cambrian rooks of ............ 171-221,330-347

sediments of......................... 358

fauna of.......... ............... 371

Iowa, Cambrian rocks of................. 187-188

Ireland, Cambrian rocka of.............. 377

Irving, K.D., on rocksof Wisconsin..... 178-179

on Cambrian and pro Cambrian formations cited .................... 181
440 INDEX.

Page. 

Irving, R. D. Continued.

on Lake Superior sandstone...... 196-197,198,

199, 335-336 

definition of Madison................ 245

of Mendota................ 245

of Eastern and "Western 

sandstone ............... 252

on lithologic character in correlation. 428 

on unconformities in correlation ..... 429-432

Irving and Cbamberlin on Lake Superior

sandstone........................ 199

J.

Jackson, C. T., on trilobite from Newfoundland............... ......... 50

on rocks of New Hampshire ......... 70

on rocks at Brain tree, Massachusetts. 74 

on fossils from Braintree, Massachusetts ............................... 89

on red sandrock...................... 96

on Lake Superior sandstone ......... 191-193

James, Edwin, on Ozark Mountains, Missouri............................. 199

on Black Hills, Dakota............... 214

correlations of....................... 396-397

Jenney.W.P., on rocks of Texas........ 218

Jobannian,definition of......... ..... 249

Jobnston, J. 3?. 'W., on rocks of New

Brunswick....................... 60

Jukes, J. B., on rocks of Newfoundland.. 50,51 

definition of St. John's............... 248

Jukes-Brown, A. J., cited on Treruadoc

slates ............................ 241

K.

Kanab Creek, A rizona, section........... 356

Katemcy, definition of................'.... 246

Kayser, E., on primordial fossils of South

America......................... 379

Kelly's Island, Newfoundland, section.... 259

Kerr, W. C., on rocks of North Carolina. 138-139 

Kicking Horse Pass, fossils from......... 163,170

King,Clarence, on rocks of Utah ........ 157

comparison of Utah and Welsh rocks. 157 

on rooks of Nevada and Utah........ 159-1GO

correlation by........................ 412

Kin g, H., on rocks of Missouri........... 199

correlations by....................... 199

Knox sandstone and shale, description of. 301-302 

fossils of............................. 302-303

Knox sandstone of Alabama............. 306-307

Knox shale of Georgia..... ..._..... 303

Knox shales of Alabama................. 307

Kootanie Pass, section ................... 163

L.

Labrador, Lower Cambrian in ............. 274

Lake Superior sandstone, description of. 188-199,

335-339 

J. J.Bigsby on......................... 188

H.W.Bayfield on...................... 188

Douglass Houghton on................ 188-190

H.D.Rogers on....._................ 190

Page. 

Lake Superior sandstone Continued.

D.D.Owen on.........................190-191

age of ....................190,191,192,194,197

C. T. Jackson on ......................191,193

Foster and Wbitney on........... 191-192,193

J. W. Foster on ... .................... 191

Bela Hubbard on.....*................191-192

Jules Marcou on........................ 192

J.D. Wbitney on......................194,198

H. R. Sehoolcraft on.................... 194

A. Winchell on......................... 194

J. S. Newberry on...................... 194

T.S. Hunt on.....................195,197,198

Charles Whittlesey on................. 195

correlated with St. Croix............... 195

Thomas ifacfarlano ou................. 195

Alexander Agassizon.................. 195

Brooks and Pumpelly on............... 196

C. Rominger on .................._... 196

R.D.Irving on................196,]97,198,199

E.T. Sweet on........................196-197

M.E.Wadsworthon..................l97,198

A. B.C. Selwyn on....................197-198

J.D.Whitney on ...................... 198

N.H. Winchell on...................... 198

T.G. Cbamberlin on.................... 198

M.E. Wadsworth on................... 198

Irviiig and Chamberlin on............. 199

fossils of............................... 228

definition of............................ 252

Lake Superior section ... ............... 336-337

Lane, A. C., on rocks at Nahant, Massachusetts, cited ................... 78

Lapham, I. A., on rocks of Wisconsin.... 172

Laramie Mountains, Wyoming, age of

Cambrian rocks of ............... 212,350

Laughing White Pish River, Michigan,

section........................... 337-338

Lea, I., on rocks at Braintree, Massachusetts ............................. 74

Lesley, J. P., on South Mountain rocks.. 127 

on Primal series ..... ....... . 129-130

atlas of Pennsylvania................ 131

work of, in Tennessee ................ 141

on rocks of Pennsylvania... ...... 288-289

Levis shales described ................... 285-286

Lewis, H. C., on primal slates and Potsdam sandstone ................... 131

Lingulella lauiborni .............. 200-201,340, 341

Little Belle Isle, Newfoundland, section. 259 

Little, George, on rocks of Georgia . .. 145 

Llano County, Texas, section ............ 355

Logan, W. E., on rocks of Newfoundland. 51 

tabulation of Lower Paleozoic rocks. 51,52 

on rocks of Lower St. Lawrence.. 115,118-119 

on rocks of Quebec..-....-.--........ 116

on Quebec group.. .................. 117

on rocks of Canada................... 207-208

on fossils of Canada...............229-230,231

on Scolithus liiiearis ................. 2dO

distribution of Trenton limestone ... 405-406 

Logan and Billings, on the rocks of the

St. Lawrence River.............. 406

Low, A. P., on rocks of Gasp6 peninsula.. 120 

on rocks of Lake Mistassini ..... 122
INDEX. 441

Page. 

Lower Cambrian, divisions of by A. Sodgwick............................. 239

Lower Cambrian fossils in Bristol County,

Massachusetts................... 271-273

Lower Paleozoic rocks, W, E. Logan's

tabulation of..................... 51..52

Lyell, Charles, on Potsdam of New York. 205 

Lymaii, U.S.,on rocks of Virginia ....... 134

M.

Mncfarlane, Thomas, on Lake Superior

sandstone........................ 195

Maclure, William, on Appalachian rocks 91 

correlations of....................... 391-392

classification of rocks ................ 392

Madison sandstone, definition of......... 245, 331

Madison, Wisconsin, section............. 332

Maine, Cambrian rocks of............. -68-69,267

Maine and New Hampshire, problems for

investigation..................... 381

Malade City, Idaho, fossils of ............ 320-321

Manuel'8 Brook, Newfoundland, section. 52,200-

261,262, 273 

Manitounuck group..... .............. 122

Marcou, J., on Georgia slates ............ 103

on red saudrock ..................... 103

on Tacouic of Lake Cbamplaiu ...... 108

on strata of Taconic system ......... 109,110

on classification of Tacouic system .. 112,113 

on ago of Lake Superior sandstone .. 192 

proposes Georgia ...... .............. 249

proposes St. Albans .............. 281

Marsh, 0. C., on fossil track from Adirondacks............................ 231

Marvine, A. R.,ou rocks of Arizona...... 220,221

Maryland, Primal series in .............. 133

Cambrian rocks of ................... 289,200

Massachusetts (eastern), J. F. and S. L.

Dana, on rocks of................ 72

Cambrian rocks of..........72-78,268-273,274

M. E. Wadswortii on rocks of........ 76,77

fossils of.... ........................ 88-90

work of C. Dewey in .... ............ 93,94

problems for investigation in ........ 381

Mather, W. W., classification of ......... 95

on the rocks of Dntchess county,

New York ....................... Ill

on Potsdam sandstone of New York. 204,205 

Matthew, G. F., rocks of Cape Breton and

Newfoundland.................... 55

classifications of rocks of New Brunswick ............................. 61

on rocks of Now Brunswick ......... 62,64

on rocks of St. John ....... ....... 64,65

on favina of Cape Breton ............. 65,84

on pre-Paradoxidos zone at St. John .65,67, 86 

classification of the Cambrian ....... 06,67

definition of Bretonian . . ........ 247

definition of St John ................ 249.

definition of Johannian .............. 249

on St. John group ...... ..........203, 264, 266

classification of rocks in Acadia ..... 265,266

comparison and correlation of rocks

of America and Europe .......... 420,421

Page.

Matthew and Bailey, on St. John group.. 02 

McConnell, E. G., work of in British Columbia........................... 164

McCreath, A., rocks of Virginia.......... 135

McCutchen, A. R., on rocks of Georgia. 145-146,304 

McGee, W. J., on homogeny in correlation .............................. 432,433

Meads, A. D., section at Stillwator, Minnesota, in well. .................. 186

Meek, F. B., fossils Irpm Antelope Spring,

Nevada.......................... 155,165

on fossils from Idaho ................ 165

fossils from Utah .................... 160

on rocks of Missouri ................. 200,339

on fossils in correlation.............. 410,411

Meek and Hayden.on rocks of Black Hills. 215 

fossils from Black Hills.............. 233

Mendota limestone,definition of ......... 245

description of........................ 331-332

Mica-schist series, C. H. Hitchcock on ... 268 

Middle Cambrian in Atlantic Coast province.............................. 274

Milne, J., on rocks of Newfoundland..... 54

Minneapolis, Minnesota, section in well.. 184 

Minnesota,D.B.Owen on rooks of....... 181

Cambrian rocks of......... ....... 181-187

N. H. Winchell on rocks of........... 181-487

general section in.................... 334

Missouri, E. James on rocks of........... 199

H. King on rocks of.................. 199

G.C. Swallow on rocks of............ 199 200

Cambrian rocks of............ 198-201, 339-341

F.B. Meek on rocks of............... 200

fossils of............................. 229

G. C. Broadhead on rocks of.......... 200,201

generalized section in ................ 340,341

problems for investigation in ........ 385

Mistassini Lake, A. P. Low on rocks of... 122

Montana, Dana and Grinnoll on rocks of. 162

F. V. Hayden on rocks of ............ 162

Cambrian rocks of............ 162,163, 323-320

Montevallo sh ales, deflni tion of ......... 247

description of........................ 308

Montmorenci Falls, E. Emmons on....... 114

J.J.Bigsby on....................... 116

Mosquito Range, Colorado, section....... 352

Moss Agate Springs,Montana, section... 325 

Mount Desert, Maine, C. H. Hitchcock on

rocks of ............. .._....... 68

N. S. Shaler on rocks of .............. 69

Mount Putnam, Idaho, section ........... 161,322

Mount Stephen, British America, section. 1C4 

fossils from .......................... 170,171

Murphy, North Carolina, rocks of........ 138,139

Murray, Alexander, on rocks of Newfoundland ........................ 62

on rocks of Canada.............._.. 208

Nahant, Massachusetts, A. F. Foerste on

rocks of.......................... 78

A. C. Lane on rocks at, cited...... j... 78

J.H.Sears on fossils from............ 78

A. F. Foerste on fossils from.......... 80
442 INDEX.

Page.

Nahant, Massachusetts Continued.

stratigraphical position of limestone. 271 

W.O.Crosby on rocks of............. 271

Nason, F. L., on Cambrian of New Jersey 123,287

Nepigon series........................... 339

Nevada, G. K. Gilbert on rocks of......... 156

E. E. Howell, on rocks in.............. 156

Arnold Hague on rocks of........158,159,160

Newberry, J. S., on age of Lake Superior

sandstone. ............... 194

on rocks of Texas ................... 218

on rocks of Arizona.........._..... 219,220

New Brunswick, A. Gesner on rocks of... 59 

W. B. Rogers on rocks of............. 60

J. "W. Dawson on rocks of............ 60

3. Robbon rocks of............. .. 60

J. F. W. Johnston on rocks of........ 60

G. F. Matthew, classification of rocks

of.-.....-'........... ........ 61

L. W.Bailey on rocks of.............. 61,64

G. F. Matthew, on rocks of........... 62.64

Cambrian rocks of.................... 273,274

problems for investigation in......... 381

New Brunswick and Cape Breton, Cambrian rocks of............... 59-67,262, 267

fossils from.......................... 80-88

C.F.Hartt on........................ 80

E.Billings on........................ 80

C.F.Matthews on...... ............. 81-88

C.D.Walcott on..................... 81

New England, C. H. Hitchcock on classification of rocks of................. 72

Newfoundland, historical review of work

in................................ 50-55

J.B. Jukes on rocks of............... 50,51

J. W. Salter on Paradoxides from.... 50,78

C. T. Jackson on rocks of...... ...... 60

H. "W". Bayfleldon rocks of............ 50

succession of rocks in................ 51

W. E. Logan on rocks of.............. 51

Alexander Murray on rocka of....... 52

primordial formations in............. 53

J.Howley on rocks of................ 53

A. Hyatt on fauna of................. 54

J.Milne on rooks of............. .. 54

C. D. "Walcott on rocks of........... 54, 55,113

G. F. Matthew on rocks of............ 55

fossils from.......................... 78-80

pre-Olenellus beds of................. 261

northwestern, Cambrian rocks of..... 253-256

southwestern,Cambrian rocks of.....256-256

eastern and southeastern, Cambrian

rocks of.......................... 257-262

Cambrian sediments of............... 309

problems for investigation in ........ 380

New Hampshire, Cambrian rocks of .70-72,267,268 

C. D. Jackson on rocks of............. 70

C. H. Hitchcock,classification of rocks

of................................ 70-71

New Jersey, Cambrian rocks of....... 122-123,287

fossils of. ........................ 154

problems for investigation in ........ 382

Newport, Rhode Island, W. B. Rogers on

rocks at.............................. 76

Newton, Henry, on rooks of Black Hills.. 216

Page. 

New York, J. D. Dana on quartzites of

eastern .............................. 109

Cambrian sediments of .............. 311

problems for investigation in ........ 381

Nichol.-on, H. A.,on life zones ........ 424-425

Niobrara Eiver, Wyoming, section....... 350

Nisconlith series, G. M. Dawson on....... 1C5

Nomenclature of formations ............. 18

Nomenclature, geologic, general considerations on......................... 236-237

Nomenclature and classifications, problems of........................... 388-390

North American Cambrian compared with

European . ................... 372-377

North American and European formations, compared .................. 414-421

North Attleborough, Massachusetts, N.

S. Shaler on rocks of.............. 77

fossilsfrom .__.................... 89

North Carolina, Cambrian rocks of .. -138-13D, 299 

problems for investigation in ........ 383

Northern Appalachian district, definition

of................................ 91,275

paleontology of ................. . 148-154

distribution of strata of.............. 275

Cambrian rocks of............. 91-122,275-287

Northern Appalachian Province, sedimentation in.......................... 284

sediments of ..................308-309,312,313

fauna of.............................. 371

Norwood, J. C., on Lake Superior rocks,

cited............................. 175,194

Nova Scotia, Cam brian rocks of......... 56-59,262

A. Gesner on rocks of................ 56

problems for investigation in ........ 380

Nova Scotia gold field, J. Campbell on.... 57

A. R. C. Selwyn on.................. 58

H.Y.flindon........................ 58

Nova Scotia metamorphic slate, J. W.

Dawson on....................... 57

Nova Scotia gneisaoid series, H. Y. Hind

on................................ 58

O.

Obolella pretiosa, range of. ....... .. 286

Ocoee, definition of....................... 252

Ocoee conglomerate, description of....... 143

Bailey Willis on..................... 299-300

Ocoee River.rocks of.................... 141

Olenellus, range of....................... 319,370

Olenellus fauna, range of ... .280,281,310,362,386-

387, 389 

Olenellus gilberti, remarks on............ 319,329

Opbir City, Utah, section.......... 156,158,319-320

Ordway, A., on fossils from Braintree,

Massachusetts... ............. 89

Owen, D. D., on rocks of Wisconsin .. 171-172,173-

175 

on rocks of Minnesota............... 181

onrocks of Iowa .................... 167

on Lake Superior sandstone ......... 190-191

on fossils of Upper Mississipi valley. 221-222,

223 

Owen, Richard, tabulation of rocks ...... 206
tNDEX. 443

Page.

Owen, K., on fossil footprints of Canada.. 230 

Ozark uplift, Missouri.................... 199,201

138 

78-80

148-154

1G5-171 

221-228

229-232

233-234 

235

162-163 

101

200-210

288-289

P.

Paint Rock, North Carolina, rocks at.....

Paleontology of Newfoundland ..........

Paleontology of the Northern Appalachian district.......................

Paleontology of Rocky Mountain Province............ ..................

Paleontology of Upper Mississippi area.-

Paleontology of the Adirondack sub-province ..............................

Paleontology of the Rocky Mountain 

sub-province.....................

Paleontology of Arizona.................

Peale, A. C., on GallatiaRiver, Montana, 

on rocks of Idaho....................

on rocks of Colorado ....... ......

Pennsylvania, Cambrian rocks of.124-132,

Pennsylvania, problems for investigation

Percival, J. Or,, on Wisconsin, cited....... 175

Perkins, G. H., on Winooski marblo...... 110

Perry, J. B., classification of rocks........ 105

on red sandrock ..................... 105

Ploche,Nevada, section.................. 156

Pogonip ridge, Nevada, section........... 158

Point Levis fossils, E. Billings on........ 116-117

Portland, Maine, C. H. Hitchcock on

rocks about...................... 68

Poi tnenf range, Idaho, section........... 321-322

Potsdam. C. H. Hitchcock on Vermont... 105 

of Adiroudacks,New York.......... 113-114

G.H.Cookon New Jersey........... 122-123

F. Prime on Pennsylvania........... 128

d'lnvilHers ou PennsyIvania......... 130

T.S.Hunt on Pennsylvania.......... 132

T. D. Rand on Pennsylvania ......... 132

W. B. Rogers on Virginia ............ 134

J. M. Safford on Tennessee........... 142-143

E. A. Smith on Alabama ............. 147,306

I. A. Lupham on Wisconsin.......... 172

,T. Hall on Wisconsin ................ 175-176

Wisconsin, compared with eastern

rock ............................. 176-177

description of Minnesota, 181,182,183,185,187 

fossils of Minnesota ................. 182,183

E. Emmons ou New Fork, 202-203,204,205,206 

L. Vanuxem on New York........... 204

W.W.Mather on.................... 204,205

Charles Lyell on..................... 205

F.B. Hough on ...................... 205-206

J.HallonNew York................. 205

T.S.Hnnton New York............. 206

J. J. Bigsbyon New York............ 206

C.D. Walcott on ..................... 207

C.E.Hall on......................... 207

Beecher and Hall on................. 207

of Wyoming......................... 211-212

of Texas..........................217,218,219

definition of ........_.............. 244

of Newfoundland.................... 254

of Wisconsin ........................ 332-334

Page. 

PotsdatnC on tinned.

distribution of ..-........'....-....... 341-342

New York, section ................... 342

formations correlated with........... 3CO

correlations with New York and

Mississippi.................. .... 408-409

Potsdamio, proposed by C. H. Hitchcock.. 252 

Powell, J. W., on rocks of Arizona....... 220-221

Primal, definitionof...................... 251

Primal series, H. D. Rogers on........... 125,126

geographical distribution............ 126

fossils of............................. 12«

equivalents of........................ 126

sedimentation of..................... 126

shown on sections.................... 126-127

F.Prime on.......................... 128

P. Frazeron.......................... 129

J.P.Lesley on....................... 129-130

of Maryland......................133,289-290

VV. B. Rogers on Virginia ............ 133-134

A. McCreath on Virginia............. 135

W. M. Fontaine on Virginia.......... 135-137

of Pennsylvania..................... 289

of Virginia.......................... 290-291

Primal slates and Potsdam sandstone, H.

C.Lewis on ...................... 131

Prime, P., on fossils of Pennsylvania.... 128

on Potsdam of Pennsylvania..... 128,131,288

on primal slates of Pennsylvania..... 128

Primordial, in Newfoundland............ 53

of Virginia.......................135,204-297

definitionof.......................... 243

fauna of Nevada..................... 155

Prospect Mountain, Nevada, section..... 158,252

Prospect, definition of ................... 159

Prospect Mountain series, fossils of..... 315

description of........................ 313,314

Frotozoic, proposed by A. Sedgwick ..... 238

Prout, H. A., on fossils from Potsdam, of

Wisconsin ................... ... 222

Ptychaspiapiochenais, range of .......... 170

Q.

Quandary creek, Colorado, fossils of...... 352

Quebec, J. J. Bigsby on rocks near....... 114

Cambrian rocks near................. 285,287

Cambrian sediments of............... 309-310

R. W. Ells on the rocks of Province of. 120-121 

Quebec province, C. D. Walcott on rocks

of................................ 121

Quebec gold fields, A. R. C.' Selwyn on.... 58

Quebec group, W.E.Logan on........... 116,117

A. R.C.Solwyn on.................... 119

fossils of, in Utah ................... 157-158

rocks of,in Wyoming.............212,213,351

Rand, T. D., on Potsdam of Pennsylvania 132 

Red saudrock, description of ........... .96 -98,250

J.Marcou on......................... 103

J.B.Perry on ........................ 105

C.H.Hitchcock on................... 106

J.D.Daua on .................^....o 107
444 INDEX.

Page. 

Red sandrock Continued.

distribution of................'........ 277

character of........................... 277

Richardson, J., on rocks of the St. Lawrence River ........._.......... 118

Riley, definition of....................... 246

Robb, J., on rocks of New Brunswick.... 60

Rockflsh Gap, Virginia, section . ..291,292-293,294 

Rocky Mountain province, problems for

investigation in...........= ...... 384-385

definition of.......................... 155,'313

Cambrian rocks of ............ 155-165, 313-329

paleontology of .__................. 165-171

sedimentation of..................... 328-329

Rocky Mountain sub-province, paleontology of ........................... 233-234

definition of......._.__........... 347

Cambrian rocks of......._......... 347-354

Roemer, F., on rocks of Texas............ 216,217

fossils from Texas ................... 234

Rogers, H. D., classification of............. 04-95

on rocks of New Jeraey.............. 122

correlation of sandstone No. I........ 124

on rocks of Pennsylvania............ 124-127

description of Primal series....... 125-126,289

on South mountain rocks............. 128

on Lake Supaiior sandstone.......... 190

principles of correlation.............. 417-418

Rogers, H. D. and W. B., definition of

Primal........................... 251

on correlation of rocks................ 403-404

Rogers, W. B., on' rocks of New Brunswick................... .......... 60,61

on rocks at Braintree, Massachusetts. 73,74 

on fossils from Pall River, Massachusetts ............................. 75

on rocks at Newport, Rhode Island.. 76 

on fossils from eastern Massachusetts. 88 

on Primal series of Virginia.. .133-134, 290-291 

sections in Virginia.................. 136

Rogers, W. B. andH. D., on lithologic character in correlation............... 428

Rome sandstone, definition of............ 247

Rominger, C., on Lake Superior sandstone 196,337 

Rosenfield station, Canada, section...... 334

S. 

Rafford, J. M., classification of rocks in

Tennessee.....................141-142,144

metamorphic rocks of eastern Tennessee.............................. 142

Potsdam group of Tennessee......... 142-143

fossilsof Tennessee.................. 154

definition of Chilhowee .............. 251

definition of Ocoee................... 252

on rocks of Tennessee................ 300-302

on classification of rocks ............ 405

Saint Albans, proposed by J. Marcou. ... 281

Saint Croix, N. H. Winchell on Minnesota. 182,183,

186 

definition of.......................... 245

description of..........I............. 330-334

Saint Croix district, Wisconsin, section .. 333-334 

Saint John, New Brunswick, work of J.

W. Dawson on rocks at .......... 61

Page. 

Saint John, New Brunswick Continued.

G. F. Matthew on rocks of............ 64-65

G. F. Matthew on pre-Paradoxides

zone at.__ ....................65,67,86

pre- Paradoxides, beds of............. 264-265

C. D. Walcott, on fossils from......... 81

A. Hyatt, on fossils from.............. 82

Saint John group, C.F.Hartt on......... 62

Matthew and Bailey on ......... .. 62

C.D. Walcott on ..................... 65

definition of.......................... 249

description of._.................... 263-264

divisions of ..................... .. 266

Saiut John,0.,on rocks of Idaho ........ 161

on rocks of Wyoming.........213, 214, 350-351

Saint John's slate, description of......... 50,51

J.F. Whiteaves on.. .... ....... 54

definition of.......................... 248

Saint Lawrence River, W. E. Logau, rocks

on...........................-.115,118-119

J.J.Bigsby on rocks of ...... ....... 116

J. Richardson on rocks of............ 118

Saint Louis, Missouri, section in well..... 200,340

Saint Peter's sandstone and Chazy limestone compared .................. 176-177

Salem Village, New York, section........ 282-283

Salt Range, India, section ................ 378

Salter, J. W., on Paradoxides from Newfoundland ........................ 50

fossils of Georgia.................... 155

on Tremadoc slates................... 241

Salter and Aveline on Caradoc........... 239

Saratoga, New York,section............. 346

Saratoga section compared with other sections ............................. 346

Saratoga County, New York, J. H. Steele

on rocks of....................... 201-202

Sardinia, Cambrian rocks of island of.... 375

Scandinavia, Cambrian rocks of.......... 375

Schell Creek Mountain, Nevada.fossils of. 158 

Schoolcraft, H. R., on age of Lake Superior

sandstone........................ 194

Scolithuslinearis.m, 132,137,147,172, 306,404, 407 

Scotland, Cambrian rocks of.............. 376

Sears, J. H., on fossils from Nahant, Mass. 78 

Secret Cafion shale, definition of.......... 246

description of........................ 315

fauna of.............................. 315

Sedgwick, A., on Upper Cambrian ....237-238,239

on Middle Cambrian ................. 238,239

on Lower Cambrian.................. 238,239

Selkirk, British Columbia,section........ 165

Selwyn, A. R. C., gold field of Quebec and

Nova Scotia...................... 58

on Cambrian group _............... 119

on the Quebec group................. 119

on Lake Superior sandstone.......... 197-198

on volcanic portion of Cambrian..... 286-287

Shaler, N. S.,on rocks of Mount Desert,

Maine............................ 69

on rocks at Braintree, Massachusetts. 75 

on geology of Bristol County, Massachusetts .......................77,271-272

Shaler and Foerste, on fossils of eastern

Massachusetts................... 89-90
INDEX 445

Shaler and Williams on rocks of Little

Falls.Now York............ ..... 207,347

Shnmard.B. F.,ou Wisconsin, cited...... 185

on rocks of Texas.................... 217

fossils from Wisconsin and Missouri. 223 

fossils from Texas ................... 234-235

Signal Hill sandstone, description of.....50, 51, 52

Sillery series, position of................. 280

Sioux quartzite, description of ........... 182,185

fossilsfrom ....................... 185

age of................................ 184-185

Smith, E. A., work of, in Alabama........ 146-148

on metamorphic rocks of Alabama... 146-147 

on classification of rocks of Alabama. 147 

on Potsdam sandstone of Alabama... 147 

definition of Montevallo ............. 247

definition of Coosa................... 247

definition of Weianer ................ 251

on rocks of Alabama................. 305-308

Smock, J. C., on the rocks of Dntohess

County, New York .............. Ill

Snowden slate quarries,Virginia, section. 297 

South America, Cambrian rocks of....... 379

South Mountain, Pennsylvania, H. D.

Rogers on sandstone of .......124,125,128

J.P.Lesley on ....................... 127

P. Fra/.er on.......................... 128

Southern Appalachian district, definition

of................................ 122,287

Cambrian rooks of........... .122-148,287-308

paleontology of ...................... 154-155

Southwestern sub-province, definition of. 216,354 

Cambrian rocks of............216-221,354-357

sediments of ......................... 357-358

Spring Creek,Dakota,section............ 348

Stevenson, J. J., on rocks of Virginia.. 137,298-209 

Steele, J. A., on rocks of Saratoga County,

Now York ....................... 201-202

on fossils of Adirondacks ............ 220

Straits of Belle Isle, Newfoundland, rocks

of.................................... 254

Strong, Moses, on rocks of Wisconsin .... 180

Sutton Mountain anticlinal, Canada...... 286

Swallow, G. C., on rocks of Missouri ..... 199- 200

Swauton, Vermont, section .......... .103,279-280

Sweet, E. T,, on rocks of Wisconsin, cited 178 

on Lake Superior sandstone....... 196,197,337

T.

Taconian, definition of ... ............ 243

Taconian system, pre-Cambrian.......... 132

Taconic slate, A. Fitch on. .......... 98-99

C. B. Adams on ...................... 09

Taconic group in Minnesota ............. 185

Taconic system, E.Emmons on......... .. 98

J. Marcou on Lake Chain plain ....... 108

J. Marcou on......................... 109-110

J. Marcou classification of............ 112-113

definition of.. ......... ........ 242-243

Tennessee, G. Trot>st on rocks in ........ 139-141

Cambrian rocks of ............139-144, 299-303

work of J. P. Lesley on rocks of...... 141

J. M. Safford's classification of rocks

of.............................141-142,144

Page. 

Tennessee Continued.

J. B. Elliott on rocksof .............. 144

Cambrian fauna of................... 154-155

Cambrian sediments of .............. 311

problems for investigations in....... 383

Texas, F. Roemer, on rocks of............ 216,217

Cambrian rocks of............216-219,354-356

B. F. Shumard on rocks of............ 217

S. B. Buckley on rocks of ............ 218

C. D.Walcott on rocks of............ 218

T.B.Comstock on rocks of.......... 219

W. P. Jenney on rocks of............ 218

J. S. Nowberry on rocks of.......... 218

paleontology of...... ............... 234-235

Cambrian sections of, compared with

others ........................... 355

division of rocks by T. B. Corns took.. 355-356 

problems for investigation in ........ 385

Thompson, Z.,ou red sandrock........... 97

Timpahntorange, Nevada, section....... 156

Tonto group, description of.............. 220,221

Tonto sandstone, definition of ........... 245

description of........................ 357

Topsail Head, Newfoundland, section.... 52

fossils of............................. 55,200

Toughkenamon division................. ]30

Tourney, M., on rocks of Alabama........ 146

Tremadoc slates ......................241-242,374

Trenton limestone, distribution of....... 405-406

Trinity Bay, Newfoundland, section ..... 53

T roost, Gerard, classification of rocks.... 139

on rocks of Tennessee............... 139-141

on Cambrian system of Tennessee. 140-141,240 

Trout Creek, Colorado, section........209-210,353

Troy, N. Y., S. W. Ford on rocks at..... , 106

J.Hall on fossils from ............... 99

Tyson, P., on rocks of Maryland......... 289-290

U.

Upper Cambrian in Atlantic Coast province.............................. 274

Upper Mississippi area, definition of .... 171

Cambrian rucks of.................... 171-199

paleontology of...................... 221-228

Upper Mississippi Valley.Cambrian rocks

of................................ 330-334

problems for investigation in ........ 385

Upham, Warren on rocks of Minnesota,

cited............................. 186

Utah. F. H. Bradley on rocks of.......... 156,157

Clarence King on rocks of........... 157

S. F. Einmons on rocks of............ 157-158

Cambrian rocks of................... 319-320

Utah and Nevada, Cambrian rocks of... .155-160,

312-320 

fossilsfrom.......................... 169, 170

problems for investigation in ........ 384

V.

Vanuxem, Lardner, on Potsdam sandstone of New York............... 204,205

Vermont, C. B. Adams on quartz rock of . 95 

C. H. Hitchcock on quartz rook of.... 96 

Amos Eaton on rocks of.............. 98
446 INDEX.

Vermont Continued.

C.H.Hitchcock on fossils from ......

J. Hall on fossils of ..................

formations of, C. H. Hitchcock on....

T. S. Hunt on geology of.............

C.H.Hitchcock on Potsdam in......

A. Wing's discoveries in.............

Cambrian rocks of...................

J.E. Wolff on fossils of...............

T.N.Dale on rocks of................

Cambrian sediments of...............

problems for investigation in.........

"Verneuil, Edward de, principles of correlations .............................

Virginia, Cambrian rocks of..... 133-138,

B. S. Lyman on rocks of..............

A. McCreath on rocks of.............

J. L. aud H. D. Campbell on rocks in..

H. D. Campbell on rocks of...........

J. J. Stevenson on rocks of....... 137,

W. M. Fontaine on rocks of...... 29),

Cambrian sediments of..............

problems for investigation in ........

W.

Page.

99

100,102

104

104

105 

107 

107 

113 

283

310-311 

381-382

414-415 

290-299

134

135

136

137

298-299

292-297

311

383

Waagen, W., on fauna of India......... 378

Wadsworth, M. E., on rocks ol eastern

Massachusetts................... 76, 77

Lake Superior sandstone ............ 197,198

on Braintree quarry ................. 271

Walcott, C. D., on rocks of Newfoundland ............................54-55,113

on St; John group.................... 65

classification of the Cambrian......66, 77,113

on fossils from Braintree............. 89

on the Cambrian of Georgia, Vermont 110 

on the rocks of "Washington County,

New York....................... U2

on granular quartz................... 112

on rocks of Province of Quebec...... 121

correlation of rocks in Tennessee.... 144

fossils from Georgia slates........... 151-152

fossils of Lower Cambrian .......... 153-154

fossils from Alabama . ............ 155

on fossils of TJtah.................... 158,166

fossils of Nevada.................160,167-170

on fossils from British Columbia .... 163-164

on Potsdam of New York............ 207

on rocks of Texas ................... 218

on rocks of Arizona ................. 221

fossils from Wisconsin and Minnesota.............................. 228

on fossils from Saratoga County, New

York .....................231-232,232-233

fossils from Black Hills......... __. 234

fossils from Texas ................... 235

principles of correlation ............. 413

Wales, Cambrian rocks of............... 373-374

Wasatch Mountains, Utah, section.._.. 157 

sedimentation of..................... 328

Washington, Iowa, section in well ....... 188

Washington County, New York, section

in................................ 281-283

Page. 

Waterville, Maine, C. H. Hitchcock on

fossils of........................ 101

Waverly gold district, Nova Scotia, H. Y.

Hind on.......................... 57

Weber Canon, TJtah, section ............. 158

Webster, J. W., on rocks of Boston and

vicinity.......................... 72

Wei sner quartzite, definition of.......... 251

description of........................ 308

Weisner",Georgia,section................ 304-305

Western border or Kooky Mountain subprovince,-definition of........... 209

Cambrian rocks of................... 209-216

Western sandstone, description of... .197,335-336

definition of.......................... 252

White, C. A., fossils of Utah ............. 166

classification of rocks of Iowa....... 187

on fossils of Arizona.................. 220-221

White, George, on rocks of Georgia ...... 144-145

Whiteaves, J. F., on slates of St. John's.. 54 

Whitehall, New York, section............ 344-345

Whitfield, R. P., on fossils from Braintree,

Massachusetts ................... 89

correlations of ....................... 108-109

fossils of northern Vermont......... 151

on fossils from Black Hills........ 216, 233-234

fossils of Wisconsin.................. 226-227

Whitney, J. D., fossils from Nevada...... 155,165

on Lake Superior sandstone ......... 194,198

principles of correlation ............. 411

Whitnoy and Wadsworth on copper-bearing rocks, cited. .................. 198-199

Whittlesey, C., on rocks of Wisconsin ... 172-173 

on Lake Superior sandstone.......... 195

William's Caflon, Colorado, section ....... 352

Williams, H. S., on life history in correlation, cited........................ 426

Willis, Bailey, on Ocoee of Tennessee.. . 2b9-300 

Winchell, A., on rocks of Wisconsin...... 178

on Lake Superior sandstone.......... 194

fossils from Wisconsin............... 225-226

Winchell, N. H., correlations of.. .109,184,186,187,

207,409-410 

on rocks of Minnesota................ 181,187

section at Emmettsburg, Iowa....... 187

on rocks of Black Hills .............. 216

fossils from St. Croix sandstone ...... 228

definitionof St.Croix ................ 245

on lithologic character in correlation. 428-429 

Wind Biver range, Wyoming, rocks of ... 350 

Wing, A., discoveries in Vermont........ 107

Winooski marble, E. Billings on.......... 103-104

C.H.Hitchcock on ................... 105

G.H.Perkins on...................... 110

Wiuwood, H. H., on fossils from Kicking

Horse Pass........................ 163

Wisconsin, Cambrian rooks of............ 171-181

D. D. Owen on rocks of....... .171-172,173-175

: I. A. Lapham on rocks of............. 172

Charles Whittlesey on rocks of...... 172-173

J.Hall on rocks of................173,175-178

geologic mapof....... ........... 378

work of E.D.Irving in............... 178

A. Winchell on rocks of.............. 178

T. C. Chamberlin on rocks in......... 179-180
INDEX. 447

Page. 

Wisconsin Continued.

L. C. Wooster on rooks of............ 179-180

Moses Strong on rocks of... ......

succession of beds of Potsdam in .... 

Wolff, J. E., on fossils from Vermont .....

on limestones of East Rutland Valley, 

Vermont.........................

Woodward, H., on trilobites of Australia. 

Woodward, John, correlations of.........

Page. 

Wyoming, F. V. Hayden on rocks of ..... 211-212

Cambrian rocks of............ 211-214, 349-351

A. Hague on rocks of ................ 212

F.H. Bradley on rocks of ............ 212

T. B. Comstock on rocks of .......... 212-213

F. M. Eudlich on rocks of ............ 213

0. St. John on rocks of................213,214

Y.

Young. A. A., on Potsdam sandstone, cited 180