3Q^2 he lifOcene of the United Si' Hardy- Willi A MS Library OE< TBSl aSOIiOQIOAXi HISTORY OF organisms (jTT]j7 a?, 17QB— JTTXiX 7, ISes) No CORNELL UNIVERSITY LIBRARY 3 1924 056 612 173 Cornell University Library The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924056612173 UNITED STATES GEOLOtilOAL SURVEY J. W. POWELL, DIEECTOK COERELATION PAPERS E o c Eisr E BT WILLIAM BULLOCK CLARK ^.^ WASHINGTON GOVERNMENT PKINTING OFFICE 1891 with the compliments of William Bullock Clark, johns hopkins university, baltimore, md. CONTENTS. Page. Letter of transmittal 9 Outline of tliis paper 11 Preface 13 Introduction 15 Atlantic and Gulf Coast region 17 Preliminary remarks 17 Historical sketch 17 General boundaries 38 Stratigrapbical and paleontological characteristics •. 39 General remarks 39 New Jersey 40 Delaware 43 Maryland 43 Virginia 46 North Carolina -48 South Carolina 50 Georgia 54 Florida .-. 55 Alabama 57 Mississippi 06 Tennessee 70 Kentucky 71 Illinois 73 Missouri '. . . . 73 Arkansas 74 Louisiana 75 Texas 76 Correlation of deposits 79 New Jersey 80 Maryland -.. 80 Virginia 80 North Carolina 81 South Carolina 82 Georgia 82 Florida 82 Alabama 83 Mississippi 83 Mississippi embay mont 83 Louisiana 84 Texas 84 Tabular representation of the Geological range of the Eocene in the Atlantic and Gnlf Coast region 85 5 b CONTENTS. Page. Atlantic and Gulf Coast region — Continued. Provisional division into provinces --• 85 New Jersey province 85 Maryland-Virginia province 86 Carolina-Georgia province 87 Gulf province , 87 Comparisons with European deposits ,-.. - 88 Appendix 90 The Brandon formation 90 Vermont 92 Pennsylvania ^. 93 Georgia - 93 Pacific Coast region 95 Preliminary remarks 95 Historical sketch 96 Stratigraphioal aid paleontological characteristics 100 Tejon group 100 Puget group 107- Grounds for the reference of the Tejon and Puget groups to the Eocene. .. 108 Interior region Ill Preliminary remarks Ill Historical sketch Ill Stratigraphioal and paleontological characteristics 131 General remarks u 131 Laramie group 132 Fort Union beds 135 Bear River Estuary beds 135 Arapaho beds 135 Denver beds 136 Middle Park beds 137 Puercobeds 137 Wasatch group ...' 139 Green River group 140 Wind River group 140 Manti beds ...._ 141 Amyzon beds 141 Bridger group : 141 Huerfano beds 142 Uinta group 143 Summary of correlative evidence 144 Table showing the relative position of the Interior deposits in the Eocene series 146 Bibliography 148 Atlantic and Gulf Coast region 148 Pacific Coast region 1,55 Interior region 156 Index 161 ILLUSTRATIONS. Faga Plate I. Map of Alabama, showing the distrilnition of Eocene strata 60 II. Distribution of the Eocene in the United States 146 LETTER OF TRANSMITTAL. TJ. S. Geological Suetet, Division of Geologic Correlation, Washington, D. C, June 1, 1891. Sir: I have the honor to transmit herewith an essay by Dr. William B. Clark on the Eocene of the United States, 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 countries; 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 Annuf.1 Report of the Survey, and on pages 108 to 113 of the Tenth Annual Eeport, as well as in a letter of trans- mittal to Bulletin No. 80 of the Survey. The present essay is the fourth of a series resulting from this work. The first, prepared by Prof. Henry S. Williams, pertains to the forma- tions of the Carboniferous and Devonian periods, and constitutes Bul- letin No. 80 ; the second, prepared by Mr. C. D. Walcott, pertains to the formations of the Cambrian, and constitutes Bulletin No. 81 ; the third, prepared by Dr. O. A, White, pertains to the formations of the Cretaceous, and constitutes Bulletin No. 82. The present essay is closely related to the one which follows it in the series, an essay by Dr. William H. Dall on the formations of the Neocene, Bulletin No. 84. Dr. Clark has devoted himself chiefly to the correlation and system- atic presentation of published material and opinions bearing on corre- lation of the formations of the Eocene. He finds that the marine faunas of the Atlantic and Gulf coasts permit a separation of the 9 10 THE EOCENE. [dull. 83. Eocene as a whole from formations belonging to earlier and later periods with a high degree of confidence, but that with present evidence the lines of separation are not sharply drawn among the marine and fresh- water formations of the Pacific Coast and the Interior region. The correlation of the individual formations one with another has not yet been satisfactorily made throughout the Atlantic and Gulf Coast, con- stituting the district best known, and still less has this been found practicable when comparison is extended to the Interior and Pacific regions. Very respectfully, your obedient servant, Gr. K. Gilbert, Geologist in Charge. Hon. J. W. Powell, Director. OUTLINE OF THIS PAPER, This essay comprises, first, a general discussion of the limitations of the term Eocene as employed in American geology. The twofold char- acter of the Tertiary (1. Eocene, 2. Neocene) in America is insisted on. After a somewhat extended review of the literature, in which the various opinions upon disputed points are especially considered, a gen- eral study of the stratigraphical, paleontological, and topographical characteristics of the Eocene in the various portions of the country is undertaken. A division of the Eocene of the United States into three distinct regions is made — 1. Atlantic and Gulf Coast region. 2. Pacific Coast region. 3. Interior region. Following a study of the stratigraphical relations of the Eocene of the Atlantic and Gulf Coast region, an attempt is made to correlate the very diverse formations of this great area. Four provinces are pro- visionally established (1. New Jersey province, 2. Maryland-Virginia province, 3. Carolina-Georgia province, 4. Gulf province), though fuller knowledge may break down their bounds. The general simi- larity of the deposits and their fossils to extra- American Eocene is shown, but detailed correlation is not considered feasible. The meager knowledge of the Pacific Coast Eocene precludes any general discussion of the stratigraphical and paleontological relations of that horizon. The local peculiarities, shown both in fossils and de- posits, are referred to, and the close relationship existing between the Eocene and Cretaceous is dwelt upon. Their separation is a matter of some uncertainty with our present information. Certain points of identity with Eocene deposits elsewhere are mentioned. Two groups of strata are recognized, one marine (Tejon group), the other brackish (Puget group). The remarkable conditions under which the deposits of the Interior region were accumulated and the interesting fauna and flora that they afford are fuUy discussed in the final division of the essay. The Lara- U 12 THE EOCENE. Iboll.83. mie problem, although more fully presented by Dr. White in his paper upon the Cretaceous, is here referred to, and facts are given to show that the Laramie is probably in part Eocene. The conflict between the evidence afforded by animals and plants is stated and the consequent hindrance to satisfactory correlation is shown. The general relations of the fauna and flora of the Eocene of the Interior to that of other regions is pointed out, though no attempt is made at a detailed corre- lation of its various members. In conclusion, an alphabetical list of the leading articles upon the Eocene of the United States is presented. PREFACE. The present report is one of a series of essays in which, as authorized by the Director, " existing data affecting the problems of American geologic nomeuclature should be collected and discussed." The division of the work a>signed to the writer embraces that portion of the Amer- ican geological column designated as the " Eocene." As the limits to be assigned to this horizon have been variously determined by different geologists, the discussion of its delimitation forms an important feature of the essay. Furthermore, the divisions into which the Eocene has been separated have each received many different names and bounda- ries, and have been variously correlated by those who have examined the different areas of their occurrence or who have employed one or the other of the various classes of paleontological data that the deposits afford. That a wide variance in the opinions of geologists upon Eocene stra- tigraphy should prevail is not surprising, but oftentimes the extreme meagerness of obtainable information on important points renders a critical comparison of their views impossible. At every point the in- suflciency of existing knowledge has been forcibly shown as the inves- tigation has proceeded. In the preparation of the essay I have been necessarily guided largely by the published opinions of others, which I have endeavored, as far as possible, to arrange logically and correlate with one another. Although, the facts employed have thus been, in the main, acquired from the literature, I have nevertheless had an opportunity of personally examining extensive areas of the Atlantic Coast region from New Jersey to Georgia, together with the more typical localities of the Interior. As the object of the report, however, is to present a summary of exist- ing knowledge rather than to give the results of original research, the investigations made have had largely for their aim the acquirement of a general acquaintance with the leading features of Eocene strati- graphy and the possible reconciliation of conflicting statements. I wish especially to thank Dr. 0. A. White, of the TJ. S. Geological Survey, for many valuable suggestions that have been kindly given during the preparation of this report. Thanks are likewise due to Dr. Whitman Cross, and Dr. W. H. Dall for much important information. Of special value in the preparation of this essay has been Prof. Heil- priu's "Contributions to the Tertiary Geology and Paleontology of the United States," from which frequent quotations have been made. 13 THE EOCENE OF THE UNITED STATES. By William B. Claek. INTRODUCTION. The Eocene of the United States is widely represented both in the Coastal and the Interior portions of the country. Formed in the several areas under very different conditions, it exhibits clearly defined dis- similarities in structure and in fossils. Marine and brackish- water strata, with their attendant lithological and paleontological charac- teristics, by which the presence or close proximity of the open sea is attested, prevail generally throughout the Coastal regions. In the Interior, on the other hand, the sediments were deposited in great fresh- water lakes, that admitted of the accumulation of beds that equal or surpass in extent those of the ocean border, and in which are entombed the remains of lacustrine life. A natural division, therefore, of the Eocene deposits into a Coastal Province and an Interior Province may be made. Furthermore, the coast regions of the Atlantic and Pacific borders are so clearly limited geographically, and at the same time pre- sent such widely varying stratigraphical relations and fossil remains, that they merit separate consideration. On stratigraphical and geographical grounds, then, the Eocene of the United States will be treated in the succeeding portions of this paper under the three divisions above outlined : I. The Atlantic and Gulf Coast region. II. The Pacific Coast region. III. The Interior region. Before proceeding further with their consideration it becomes neces- sary to outline, in a general way, the limits of the term Eocene as em- ployed in the present essay. As one of the eleven classiflcatory units established by the U. S. Geological Survey to designate the several time periods in American geological history, it has equal value with the terms Cretaceous and Neocene, the names adopted for the preceding and succeeding divisions, respectively. Together with the Neocene, it constitutes what is frequently denominated the Tertiary, and individu- ally includes those deposits that have been hitherto described in Amer- 15 16 THE EOCENE. [bdi.l.83. icau literature as Eocene and Oligocene. These latter terms, as indi- cating divisions of the lower Tertiary, have no place in the nomencla- ture of American geology, however applicable they may be found for European formations. The Tertiary strata of America, on both strati- graphical and paleontological grounds, may be best divided into two groups. The term Eocene, which is retained as equivalent to Lower Tertiary, may or may not coincide with the division so designated by European geologists. The attempt at a detailed correlation of American formations with European, so often made in the past on insufiicient data, is greatly to be deprecated. The Tertiary strata of America, deposited under con- ditions peculiar to themselves, merit consideration upon those charac- teristics rather than upon features typical for other and far distant regions. Certainly not until the strata have been much more exhaust- ively studied will it be possible even to approximate to an accurate correlation of the leading divisions of the American Tertiary with those of other lands. In the treatment of the subject in the pages of this paper the Eocene, so far as practicable, will be separated into three divisions : (1) Lower. (2) Middle. (3) Upper. Althoughin many localities too little is known of the deposits, due to the partial representation of the series, to make an accurate determination possible, yet where best developed a triple division is the most natural. More complete observations will doubtless clear up many points that are now obscure, and enable a correlation to be made of dissimilar de- posits in contiguous areas that at present defy comparison. Until such exhaustive investigations have been made many discrepancies in our knowledge of American Tertiary geology must continue to exist. ATLANTIC AND GULF COAST REGION. PKBLIMINART EEMARKS. The Atlantic and Gulf Coast region, as regards its geographical ex- tent, its stratigraphical diversity, and its copious literature far exceeds in importance the other Eocene areas. It stretches as an almost con- tinuous belt along our eastern coast from Few Jersey to Texas, and has been variously considered in oificial reports of the several States aud in numerous articles scattered through scientific journals. Wide differences of opinion have prevailed among the various writers, as regards the geographical and stratigraphi«al limits of the Eocene, as will be set forth ia the historical sketch. In the following pages the stratigraphical relations of the Eocene are discussed in considerable detail, and the leading sectiong for each State given with their typical fossils. The topographical characteris- tics, although greatly modified by later deposits, are yet suflBciently distinctive in many instances to demand attention. An extended correlation of the Eocene deposits of the Atlantic and Gulf Coast region is generally unsatisfactory, although a more or less accurate reference of the strata to a relative position in the series may usually be made. The fauna, in different portions of the area, shows marked variations, but is as yet too imperfectly understood to warrant a division of the Atlantic and Gulf Coast region into established provinces. A provis- ional separation is, however, attempted. When further correlation is made by comparison with European formations the task is still more difficult and the results of correspondingly less value. To each of these subjects a special chapter will be devoted." HISTORICAL SKETCH. The earlier writers upon the geology of the North American continent dwelt exclusively upon the general relations of the strata, and included the entire Upper Mesozoic aud Cenozoic series of the coastal plain in the " alluvial formation." Later others, whose personal investigations or study had extended to an examination of the geology of foreign lands, endeavored to correlate upon lithological grounds the various forma- tions of the coastal area with the minuter divisions established in Europe. Recognizing the futility of such detailed correlation before a knowledge of the fossils of the several horizons had been acquired, Conrad, Morton, Say, Lea, and others proceeded with marked industry Bull. 83 2 17 18 THE EOCENE. [BrtL.83. to describe the rich fauna that the deposits afforded. -Based upon this work, many important papers appeared, dealing either with the rela- tions of local deposits or the general features of the entire coastal region. The State geological surveys, during the same time, made more or less complete examinations of their respective territories, pre- senting us with data relating to the stratigraphy. In short, during the last half century the activity displayed in every other field of American geology has not been wanting in this, the eastern Tertiary belt, if the numerous publications are a criterion. Unfortunately, the results as sL whole have not been as valuable as in many other lines of investi- gation, although many marked exceptions might be cited. In the historical sketch that follows the leading articles and report^ bearing upon the different epochs in the evolution of our knowledge of the Eocene will be considered, though much of value must of necessity be hurriedly passed over. The first important contribution appeared in 1809, when William Maclure^ read before the American Philosophical Society at Philadel- phia his " Observations on the Geology of the United States," in which the entire coastal plain is referred to the alluvial formation, the fourth of the grand divisions of the geological column according to the Wer- nerian classification which Maclure adopted. The general limits of the region are given, and the shell deposits, limestone, and buhrstone are referred to, although it is evident that the author was ignorant of their stratigraphical position or taxonomic importance. Maclure subse- quently revised and enlarged the work, which appeared in book form'' in 1817, and in the Transactions of the American Philosophical Society for the same year.' A few years subsequent to the appearance of Maclure's articles H. H. Hayden published a volume of " Geological Essays " (1820) in which an explanation is given of the great accumulation of " alluvial deposits" in the eastern and southern portions of the United States, and the stratigraphy of the region is described in much greater detail than by his predecessor. Reference is made to the wide distribution of fossil shells, and vertebrate remains, and many localities are cited. A second work of the same general character, so far as it relates to the geology, was published in 1822, by Parker Cleveland, entitled "An Elementary Treatise on Mineralogy and Geology," in which, on page 785, under " Eemarks on the Geology of the United States Explanatory of the Subjoined Geological Map," the author defines the limits of the " alluvial deposits," and in general terms describes their lithological character. 'Am. Phil. Soo. Trans., Tol, 6,1809, pp. 411-428. A translation appeared in the Jonmal de Phy- sique, vol. 69, 1809, pp. 204-213, and vol. 72, 1811, pp. 137-165. ' Observatiuns on the Geology of the United States of America, etc. By William Maclare, Phila- delphia, 1817, 8vo , 130 pp. 'Am. Phil. Soc. Trans., new ser., vol. 1, 1817, pp. 1-92. Also Leonard's Zeitsohrift, Band 1, 1826, pp. 12^1.% CLARK.] HISTORICAL SKETCH, ATLANTIC AND GULP COAST. 19 Before the publication of the latter work, articles descriptive of local points in the stratigraphy had appeared, chiefly as communications to the American Journal of Science and Arts.* Of importance among these is a paper by Elias Gornelius in which the limits of the alluvial formation of the Mississippi are outlined and potent reasons given for its extension beyond the boundaries assigned by Maclure. Samuel Akerly, in an essay published in New York in 1820, discusses the " alluvial deposits " of northern New Jersey. In this paper the marl beds, together with some of their fossils, are described, but no evidence is adduced that the author recognized their taxonomic posi- tion. In volume 3 of the American Journal of Science two articles appeared : The first by John Dickson,^ on the geology of parts of North and South Carolina ; the second by Dr. Troost,^ on the stratigraphy of the region about the Magothy Eiver, Anne Arundel County, Maryland. James Pierce,_ in a " Notice of the Alluvial District of New Jersey,"* published in 1823, describes the marl deposits of Monmouth County. By far the most important contribution to the stratigraphy of the coastal plain that had up to that time appeared was made by Prof. John Finch in a " Geological Essay on the'Tertiary Formations in America,"^ in the American Journal of Science and Arts for 1824. This was the first attempt at a correlation ,of the deposits of tlie coastal plain on scientific grounds, and although thus early in the history of the subject, minute comparisons, which are always unsatisfactory, were made, yet the knowledge of American Tertiary formations was mate- rially advanced. The author says : In America an immense tract of country, extending from Long Island to the Sea of Mexico, and from 30 to 200 miles in width, is called an alluvial formation. From an examination of fossils brought from that quarter of the United States, from a per- sonal inspection of some of its strata, and the perusal of most of the .publications which bear a reference to it, I wish to suggest that what is termed the alluvial for- mation in the geological maps of Messrs. Maclure and Cleveland is identical and conleiuporaneous with the newer Secondary and Tertiary formations of France, Eng- land, Spain, Germany, Italy, Hungary, Eoland, Iceland, Egypt, and Hmdostan. The-deposits, which will be discussed in a later portion of this report, as exhibited in New Jersey, Maryland, on the James Eiver, Virginia, on the Santea River and at Orangeburg, South Carolina, at Shell Bluff, on the Savaunah Eiver in Georgia, and at numerous localities in Alabama and Mississippi are considered in greater or less detail, and an attempted correlation made with one another and with European strata. In short, the author states that — Many more instances might be advanced to establish the identity of what has been called the alluvial district in America with the Tertiary formation of England and 'Am. Jonr. Sci.,Tol.l, 3819, pp. 214-226,317-331. 2 Ibid., vol. 3, 1821, pp. 1-5. 8Ibid.,T0l.3, lS21,pp.8-15. « Ibid., vol. 6, 1823, pp. 237-242. s Ibid., vol. 7, 1824, pp. 31-43. 20 • THE EOCENE. [bull. 83. tbe continent of Europe. The fossil shells from the various beds would not, perhaps, be exactly like those of Europe, but a sufficient number would be found so to estab- lish their relation and order of succession. lu the same volume of the American Journal, Prof. Edward Hitch- cock * describes the presence of the "Plastic Clay formation" on Martha's Vineyard and the Elizabeth Islands, an attempt at detailed correlation that is not supported by facts as we now interpret them. During 1824 and 1825 Olmsted's "Eeport on tbe Geology of North Carolina " appeared, and a review ^ of tbe same in the American Journal in 1828. The shell marl of the Nense is herein described, together with its fossils. During the year 1825 Jer. Van Eensselaer delivered a course of lec- tures in the New York Athenaeum , on geology, that were subsequently published in book form.' The author adopted the classification pro- posed by Finch, although he confined his descriptions to the more northern representatives of the Tertiary series. On page 34 of "Mills's Statistics of South Carolina" (1826) reference is made to the limestones of the Santee and Savannah Eivers, which contain " many oyster shells of uncommon size, and different from those now found near our shores." An occurrence of a shell deposit at Orangeburg is described in this work in considerable detail, and the general geological characteristics of the region are given. The American Journal for 1826 contains a communication by James Pierce* "On the shell-marl region of the eastern parts of Virginia and Maryland," in which reference is made to tbe river sections on the James and Potomac, and to the " shell rock " at Upper Marlboro, Mary- land. In volume 13 of the same journal Mr. S. Porter,^ in a letter to Prof. Silliman, gives some valuable information in regard to the shell deposits of Alabama; and Elisha Mitchell^ presents still more detailed state- ments in regard to tbe stratigraphy of similar strata in South Carolina. In notes' by Lardner Vanuxem, arranged by Dr. S. G. Morton for publication in the Journal of the Academy of Natural Sciences of Philadelphia, tbe attempt is made to more accurately define the limits of tbe Tertiary. Tbe author states that much that bad been desig- nated'by that name properly belongs to other formations. Up to the year 1830 all investigations upon tbe stratigraphy of the Tertiary had been carried on in tbe main independently of a study of its fossils. Generic similarities had been cited as grounds for correla- tion, and although this aided largely in determining the limits of the Tertiary itself, further subdivisions were impracticable. 'Am. Jonr. Sol, vol. 7, 1824, pp. 240-248. ' Ibid., vol. 14, 1828, pp. 330-251. ' Lectures on Geology, 1825, 8vo., 358 pp. ' Ibid., vol. 11, 1826, pp. 54-69. «Am. Jour. Sci., vol. 13, 1828, pp. 77-79. "Ibid., 1828, pp. 336-347. ^Geological observations on the Secondary, Tertiary, and Alluvial formations of tbe Atlantic coast of the United States of America,' FliUadelphia Acad. ItTat. Scl., Jour., vol. 6, 1828, pp. 59-71 CLABK.] HISTORICAL SKETCH, ATLANTIC AND GULF COAST. 21 With the publication of Conrad's article ^ "On the Geology and Or- ganic Remains of a part of the Peninsula of Maryland," with an aj)- peiidix containing descriptions of new species of fossil shells, a new era in the investigation of the Atlantic and Gulf Coast strata was inaugurated. It is true that Say^ had described several Tertiary spe- cies, but, as stated in Conrad's paper, he did not " draw any geological inferences from the organic remains examined." Conrad from the first applied the paleoutological evidence he possessed to an interpretation of the stratigraphy ; and although many of his conclusions were erro- neous, still the knowledge of the geology of the coastal plain was very materially advanced. In this first paper such well known early Ter- tiary forms as Twrritella Mortoni, Oucullcea gigantea, and Grassatella alceformis are figured and described, and the presence of Venericardia planicosta Lamarck is also noted. Making use of the data afibrded by these investigations, the strata at Fort Washington were correlated with the London Clay of England. In 1832 Conrad published an important work on the "Fossil Shells of the Tertiary Formations of North America,"^ which was followed in 1833 by a description* of a large number of new forms from Claiborne, Ala- bama. In the latter article the position of the white limestone below the Claiborne sands is affirmed. The same year Lea published his " Contributions to Geology"^ in which he treats of the general features of the Atlantic and Gulf Coast Tertiary, but especially considers the Claiborne section, describing 219 new species. The Claiborne beds are correlated with those at Fort Washington, Maryland. In regard to their European equivalence, the author says : After a careful examination of a great number of genera and species from the Tertiary of Clailiorne, Alabama, I liad no hesitatiou in referring them to the same period as the London Clay of England, and the Calcaire Grossier of Paris. » « » This part of the Tertiary formation * * * is called by Mr. Lyell the Eocene period. This is the first application of the term Eocene to American deposits. About the same time Withers gave in the American Journal ^ the general features of the section at St. Stephen's Bluff, Alabama. A year later, in " Observations on the Tertiary and more recent formations of a portion of the Southern States," ' Conrad adopted the term Eocene for the well known sections at Fort Washington, Mary- land ; Eutaw Springs, South Carolina ; Shell Bluff, Savannah Eiver, Georgia ; Claiborne, Alabama, and many intermediate points. In an ' Philadolphia Acad. Sci., Jour., vol. 6, 1830, pp. 205-217. ^Am. Jour, Sci., vol. 1,1819, pp. 381-387; toI. 2, 1820, pp. 34-45. Philadelpbia Acad. Nat. Sci.,Jour., vol. 4, 1824, pp. 124-155 (Oetrea coTnpressirostra). t 3 8°, 56 pp. 16 pis., Philadelphia, 1832. 4Am. Jour. Sci., vol. 23, 1833, pp. 339-346, 405. * Contribations to Geology, by I. Lea. 8vo. 1833. 227 pp., 6 pis. «Ain. Jour. Sci., vol. 24, 1833, pp. 187-189. 'Philadelphia Acad. Nat. Sci., Jour. vol. 7, 1834, pp. 116-157. 22 THE EOCENE. [buli.83. appendix to this paper many new fossils are described. A diagram representing the blufi' at Claiborne is added, in wliich tbe wbite lime- stone is again placed below the fossiliferous sands. Ooniad quotes Lyell on European formations as stating that no secondary fossils are found in the Eocene, yet his own observations at Claiborne warranted him in claiming the admixture of a few si)ecies. .He further considers the Eocene of Claiborne older than the Eocene of Fort Washington, Maryland, and of Europe. Prof. Chas. TJ. Shepard published in the American Journal of Science the same year " Geological Observations upon Alabama, Georgia, and Florida," ' in which several of the Eocene localities of those States are described. Three other articles appeared at this time by Harlan/ McGuire,' and W. B. Eogers,* that added somewhat to the knowledge of local deposits. The paper by Eogers is especially iuteresting, as the first of a series of articles and reports on the geology of Virginia that give us a clearer insight into the Tertiary geology of that State than of any other on the Atlantic seaboard. About the same time Dr. Morton published a " Synopsis of the or- ganic remains in the ferruginous sand formations of the United States," in which several species from the " white limestone " of South Caro- lina are included through a misconception of the proper stratigraphi- cal position of that formation. In 1835 Conrad added two more papers' on the Atlantic Tertiary region. In the transactions of tlie Geological Society of Pennsylvania he says : Having Iracedthe liiirr stone of Georgia, tbo fossilferous sautlsof Claiborne, Ala- bama, and a calcareous clay near Orangeburg, Soutb Caroliua, to common or syn- chronous origin, I immediately perceived that tbe deposit at Upper Marlboro was a link in tbe chain of older Tertiary beds. Eeference is made in both articles to the commingling of the Creta- ceous "and Eocene forms, a point subsequently more fully considered. It was held, at the same time, worthy of mention that no fossils had been found common to the Eocene and Miocene. H. B. Croom '^ published an account of early Tertiary fossils found in Craven County, North Carolina, in the American Journal of Science of the same year. William B. Eogers published in the Farmers' Eegister for 1835, " Fur- ther observations on the greensand and calcareous marl of Virginia"' The marked lithological similarity of the beds to^the greensand of New ' Am. Jonr. Sci., vol. 25, 1834, pp, 162-173. ' Am. Phil. Soc. Trans., now ser., vol. 4, 1834, pp. 397-403. 'Am. Jour. Soi., vol. 26, 1834, pp. 93-98. * "Farmers' Eegister, 1834. Eeprinted in Geology of the Virginliis, 1884, pp. 3-9. 5 Pennsylvania, Geol. Soc. Trans., 1835, pp. 335-341; Am. Jour. Sci., vol. 28, 1835, pp. 104-111. « Am. Jour. Sci., vol. 27, 1835, pp. 168-171. 'Eeprinted in Geology of the Virginias, 1884, pp. 11-20. 23 Jersey is mentioned in this article, but the character of the fossils is shown to place those of Virginia in the Eocene. For the next few years Professor Eogers devoted himself to a most careful study of the Tertiary geology of Virginia, and as State geologist published annual reports ^ giving detailed accounts of the progress of the survey. Numerous sections of early iTertiary marl and greensand are herein described, and lists of characteristic fossils are given. As these publications afford the most important literature upon the geology of Virginia, a consideration of the details will be reserved for a later por- tion of this report. In conjunction with his brother, H. D. Eogers, the same writer pub- lished in the Transactions of the American Philosophical Society of Philadelphia a series of articles entitled, " Contributions to the geology of the Tertiary Formations of Virginia," * that, beyond the description of several new species of early Tertiary shells, cover much the same ground as the annual reports. During this same period, Mr. T. A. Conrad contributed several pa- pers ' of importance, first among them being a special treatise on Ter- tiary shells,* that appeared in 1838. A point much discussed in southern Tertiary stratigraphy was con- sidered by Conrad in the American Journal of Science for 1840, under the title "On the geognostic position of the Zeuglodon or Basilosanrus of Harlan."* The statement is made that the Zeuglodon occurs " in the limestone of Alabama immediately under the lower Tertiary fossiliferous strata," and further that " this formation seems to fill the chasm which in Europe has been often noticed to occur between the Secondary and Tertiary series." While Prof. William B. Eogers and T. A. Conrad were conducting their important investigations, others were not idle. H. D. Eogers, as State geologist for Kew Jersey, published reports in 1836 and 1840, in which the marls of Monmouth County at Shark Eiver and Squankum are described and referred to the "upper Secondary." In Delaware the State geological survey, under J. C. Booth, published two annual reports of work done during 1837-'38, which were subse- quently (1841) issued in enlarged form as a " Memoir." In Maryland a series of annual reports, extending from 1833 to 1840, were inade by the State geologist, J. T. Ducatel, to the legislature. The sections exhibited at numerous points in the Tertiary area are given in these reports, together with lists of fossils. In 1836, J. E; Cotti'ng published a " Eeport of a Geological and Agri- • Reports were published for the years 1835-1841, inclusive. Bepiinted in Geology of the Virginias, 1884, pp. 21-546. 2 Am. Phil. Soc., Trans., newser., vol. 5, 1835, pp. 319-342; vol. 6, 1837-1839, pp. 347-370, 371-377. Ah. straot in Amer. Phil. Soc. Proc, vol. 1, 1840, pp. 88-90. "" 'Am. Jour. Sci., vol. 35, 1839, pp. 237-251 ; vol. 38, 1840, pp. 86-93. Philadelphia Acad. Nat. ScL, Jonr., vol. 8, 1841, p. 190. Philadelphia Acad. Nat. Sci., Proc, vol 1, 1841, p. 33. 'Fossils of the Tertiary Formations of the United States, 8vo., 1838, 89 pp., 49 pla. •Am. Jonr. Sci.. vol. 38, 1840. pp. 381-383. 24 THE EOCENE. [bull. 83. cultural Survey of Burke and RLclimond counties, Georgia," in wliich the character bf the Tertiary deposits is reviewed in considerable detail, though the author had little conception of their stratigraphical rela- tions. The occurrence of early Tertiary strata in Arkan-sas is recorded in Featherstonhaugh's " Geological Eeportofan Examination made in 1834 of the Elevated Country between the Missouri and Kod rivers." Mne biennial geological reports were presented by G. Troost, the State geologist, to the legislature of Tennessee, between the years 1831- '47. The geology of the eastern i)ortion of the State is in the main considered, though now and then references are made to the later formations of the west. The information conveyed is, however, of slight importance, so far as the older Tertiary is concerned. Very much the same remarks apply to W. W. Mather's " Eeport o;i the Geological Eeconnaissance of Kentucky, made in 1838." The activity manifested by the geological surveys of the States just mentioned in the study of the Tertiary deposits, was accompanied by mucb private investigation, the result of which appeared in numerous articles in the American Journal of Science and Proceedings of the Academy of Natural Sciences of Philadelphia. Some of the more striking features of the topography and geology of Florida are pointed out by Maj. Henry Whiting, in a paper entitled " Cursory Remarks upon Bast Florida in 1838,"' that was published in ■ 1839. In 1841 Edmund EavenaP and Henry C. Lea' published descriptions of new Eocene fossils from South Carolina and Alabama, respectively. An article by James T. Hodge, on " Observations on the Secondary and Tertiary Formations of the Southern Atlantic States,"^ followed in the succeeding volume of the American Journal of Science. So far as the Eocene is concerned, his observations chiefly related to points in North and South Carolina, and to Shell Bluff and Jacksonboro,.in Georgia. In this article the limestone and conglomerate on the North- east Cape Fear Eiver and at Wilmington are held to be an "upper Sec- ondary" deposit, interposed between the Cretaceous and Eocene. Some interesting points in the Eocene stratigraphy of Virginia were reported by Prof. Tuomey, in 1842,^ from a shaft sunk at Evergreen, on the James Eiver. In the Proceedings of the National Institution for the Promotion of Science, Conrad contributed further " Observations on a portion of the Atlantic Tertiary Eegion, with a description of new species of Organic Eeniains."" Especial Importance was at that time attached to the fact ' Am. Jonr. Sci., vol. 35, 1839, pp. 47-64. 2 Philadelphia Acad. Nat. Soi., Jonr., vol.8, 1841, pp. 333-336. s Am. Jonr. Sci., vol. 40, 1811, pp. 92-103. * Ibid., vol. 41, 1811, pp. 332-348. "Ibid., vol. 43, 1842, p. 187. « Second Bulletin, 1842, pp. 191-194. (See Eogera, Am. Jour. Sci., vol. 47, 1844, p. 254.) CLAKK.1 HISTORICAL SKETCH, ATLANTIC AND GULF COAST. 25 that the author found what he considered proof of the commingling of Secondary and Tertisiri^ types. He presented a list of forms that were supposed to show the connection of the "white limestone" of Alabama to the " greensand formation " of New Jersey. The first of Lyell's contributions to the literature of the Eastern Ter- tiary belt appeared in the Proceedings of the Geological Society of London, for 1842. His conclusions were derived from personal observa- tions, and were of special value from his wide knowledge of the Ter- tiary in other portions of the globe. He succeeded in explaining many hitherto imperfectly understood points in American Tertiary stratig- raphy.i The narrative of this first report contains the following state- ment: Having examined the most important Ciotaceons deposits in New .Jersey, Mr. Lyell proceeded, in the autumn of 1841 to investigate the Tertiary strata of Virginia, the Caroliu.as and Georgia, witli a view to satisfy himself, first, how far the leading di- visions of the Tertiary strata along the Atlantic border of the United States agree in aspect and organic contents with those of Europe ; and secondly, to ascertain whether any rocks containing fossils of a character intermediate between those of the Creta- ceous and the Eocene beds really exist. The conclusions at which he arrived from his extensive survey are given briefly a,s follows : (1) The only Tertiary formations which the author saw agree well in their geo- logical types with the Eocene and Miocene beds of England and France ; (2) he found ' no Secondary fossils in those rocks which have been called nppcr Secondary, and supposed to constitute a link between the Cretaceous and Tertiary formations. Each of the above mentioned States was at this time separately con- sidered and a careful description given of every locality visited. During the next few years six important contributions by the same writer to the Tertiary geology of the eastern United States, appeared in the Proceedings and Quarterly Journal of the Geological Society of London. In most cases special points in the stratigraphy, that had been the subject of discussion by American geologists, were taken up, and much light thrown upon the questions at issue. In regard to the occurrence of early Tertiary strata on Marthas Vineyard, as claimed by Prof. Hitchcock'* in 1824, when the deposits at Gay Head were correlated with the "Plastic and London clay of Alum Bay," Mr. LyelP thought that the evidence was altogether in favor of considering them Miocene. In an article on the " Cretaceous of New Jersey and other parts of the United States bordering on the Atlantic"^ the lithological similar- ity of the Eocene and the Miocene farther south to the Cretaceous of New Jersey, and the necessity of fossils for the identification of the various green sand horizons, are clearly set forth, thus substantiating the earlier claims of Rogers. A later communication " On the Miocene Tertiary strata of Mary- » Geol. Soc, London, Proc, vol. 3, 1842, pp. 735-742. •Am. Jonr. Soi., vol. 7, 1824, pp. 240-24S. • Geol. Soc. London, Proc, vol. 4, 1843, pp. 31-38. «Ibid, Proc, vol. 4, 1844, pp. 301-306. 26 THE EOCENE, [bum-SS. land, Virginia, and North and Soutli Carolina."' contains numerous sections in which the Eocene occurs. , Immediately following the last i)aper in both the "Proceedings" and the " Journal," are the " Observations " of Mr. Lyell " on the White Limestone and other Eocene or Older Tertiary formations of Virginia, South Carolina, and Georgia."^ After stating that the Eocene of Vir- ginia " consists in great part of green sand and marl, containing green earth * * * like that which characterizes the Cretaceous strata of New Jersey," he adds : Farther south, in North and South Carolina and in Georgia, the Eocene formation acquires a larger development and a new )uineral type, consisting of highly calcare- ous white marl and white limestone, and passing upward, especially in Georgia, into red and white clays, ferruginous sards, with associated layers of burrstone and siliceous rock. Speaking of the already well known Claiborne section, he states in an article " On the newer deposits of the Southern States of North America"' that the relationship of the deposits is different from that previously held, inasmuch as the "Nummulite limestone" occurs above the Claiborne fossiliferous sands and not below, and that the remains of the Zeuglodon are always found "in the Eocene white limestone below the level of the Nummulitic rock and above the beds which contain the greater number of perfectly preserved Eocene shells," among them Cardita planicosfa, and Ostrea sellwformis. Writing^ on the same sub- ject a year later, he reaffirmed the position he had previously taken in this matter, showiug at the same time from numerous sections the much wider application of this relationship of the strata. During this time Lyell made four contributions'* to the American Journal of Science, which contain in the main the same conclusions as the previously cited articles. Murchison,^ in his presidential address delivered to the Geological Society of London in 1843, reviewed the results of Lyell's investigations - upon the "Older Tertiary" strata of America, and added his own in- terpretation of a few points. During these years, due in part to Lyell's insinring presence and valuable publications, many articles appeared from the pens of Ameri- can geologists. Dr. Morton'' found it necessary in 1842 to correct cer- tain statements he had made in his synopsis in 1834 in regard to the occurrence of Cretaceous fossils, since the observations of Lyell had shown the deposits to be Eocene. 'Proc. Geol. Soo. LoDdon, vol. 4, 18d5, pp. 547-563 ; and Quart. Jonr. GeoI.Soc. London, vol. 1, 1845, pp., 413-429. ^Proc. Geo!.Soc. London, viil.4, 1846, pp. 663-Si76j and Qu.irt. Jour. Geol. Soc. London, vol. 1, 1845, pp. 429-442. 3 Quart. Jour. Geol. Soc. Lnndon, vol. 2, 1846, pp. 405-410. • Ibid., vol. 4, 1847, pp. 10-17. 'Am. Jour. Sci.,vol.47, 1844, pp. 213, 214; 2d8er.,vol. 1, 1846, pp. 313-315 ; 2d Ber., vol. 3, pp. 84-39 j Sd ser., vol. 4, 1847, pp. 186-191. « Proc. Geol. Soe. London, vol. 4, 1843, pp. 127 133. ' Philadelphia Acad. Nat. Sci., Jour., vol. 8, 1842, pp. 216-227. CLAiiK.j IIISTOEICAL SKETCH, ATLANTIC AND GULF COAST. 27 The ibllowiug year Edmund EnfQn, director of the agricultural sur- vey of South Carolina, presented to the legislature a report Mn which the early Tertiary marls are given the name of the " Great Carolina bed." He states that "this great deposit has been by d liferent geolo- gists considered as belonging to different formations. Vanuxem first, and also Conrad and Morton afterward, supposed it the 'Upper Creta- ceous.' Lyell, from recent inspection, includes it in the Eocene." He then adds: "The 'Great Carolinabed'of marl will serve every present purpose of designation and distinction as well as if it were definitely settled and the bed named either Upper Cretaceous or Eocene." Over thirty finely printed pages are devoted to a detailed description of the area occupied by these calcareous deposits and the siliceous beds along their northern margin. The stratigraphical position of the latter is not properly interpreted in this work. In short, the siliceous beds are de- scribed as overlying tlie calcareous deposits. Several papers treating especially of Eocene fossils appeared during this aijid the succeeding year by Bulkley,^ Conrad,^ and Eavenel." In the " Supplemental Euport of the Agricultural Survey of South Carolina for 1843," Prof. M.Tuomey discusses the character and geolog-j^ ical age of the " marl in adjacent parts of North Carolina." The occur- rence of the " Great Carolina bed " with its characteristic fossils is asserted from the region to the north and northeast of Wilmington. In the American Journal of Science for 1844, the same writer^ expresses the opinion that the South Carolina formations will prove older than the Eocene of Maryland and Virginia, although he accepts Lyell's position that they are not " Upper Secondary." In an address delivered at the meeting of the Association of Ameri- can Geologists and Naturalists, held in Washington in May, 1844, Prof. H. D. Eogers presented an outline of opinions regarding Ameri- can Tertiary formations,'' in connection with a general statement of progress in American geology. From the importance of the Zeuglodon as a charcteristic fossil of the Jackson group of the Upper Eocene, and the extended discussion which its character and geological position have hitherto occasioned, it be- comes necessary to refer briefly to the extensive literature upon that subject. Although originally described as a saurian by Dr. Harlan,' in 1834, under the name of Bnsilosaurus, its raauimalian character was subse- * Kcport of file Cuniraenoement ami Progress of tbe Agricultural Survey of South Carolina for 1843. Columbia, 1843. 2Am. Jour. Soi., vol. 44, 1843, pp. 409-412. 3 Pliiladelphia Acad. Nat. Sci., Proc. vol. 1, 1843, p. 310 ; vol. 2, 1844, pp. 173, 174. < Ibid., vol. 2, 1844, pp. 96-98. ' Am. Jour. Soi,, vol. 47, 1844, p. 117, = Ibid., vol. 47, 1844, pp. 254-259. 'Am. Phil- Soc, Trans., now ser., vol. 4, 1834, pp. 397-403; Pennsylvania Geol. Soc, Trans., vol.1, 1853, pp. 348-357. 28 THE EOCENE. fBULt.SS. quently established by Richard Owen^ and the name Zeuglodon sub- stituted. Later, papers appeared by Wyman,'' Eogers,' Bulkley,* Lister,* Gibbes,*" Tuomey,' and others, in which the views of Owen were sub- stantiated, and more definite information given in regard to the locali- ties and geological horizon of the many specimens up to that time dis- covered. Important contributions to the geology of the Southern States were made during the years 1846-'49. Obnrad alone published eight^ arti- cles in which many new species of fossil shells are described, and con- siderable additions made to the knowledge of the stratigraphy of the Eocene in Florida and Mississippi. In the American Journal of Science for 1846, Dr. Conrad^ made the iirst attempt at correlating the " limestone " of l^'lorida. From a study of the fossils he proposed to place it in the Upper Eocene together with " the limestone of the Savannah Eiver in Georgia, between Savannah and Shell Bluff." ♦ In 1848 Gonrad" published adescription of AturiaziczaGfTom theupper f)ortion of the upper marl bed of New Jersey, and referred the marl, principally on account of the presence of this shell, to the Eocene era. During this time Morton," Bouv(5,'^ Lea," and Gibbes" described many new fossils, while Allen, ^^ Gouper,^^ Agassiz," Tuomey,-'^ Hale,''' and Holmes^" contributed important data relative to the stratigraphy of local areas. Tuomey, in a "Eeport on the Geology of South Carolina," published in 1848, enters into a detailed description of the geology of that State, and proposes three divisions for the Eocene formation, viz: 1, Buhr- stone; 2, Santee marls, and 3, Ashley and Cooper marls. ' Geol. Soc. London, Pioc.vol.S, 1839, pp. 24-28; Geol. Soc, London, Trans. 1842, pp. 69-79! Ann.Sci. Nat., vol. 12 (Zool.), 1839, pp. 222-229; Mag. Nat., vol. 3, 1839, pp, 209-213. ^Boston Soc. Nat. Hist., Proc, vol. 2, 1845, pp. 65-68. 3 Ibid., p. 79. ■■ Am. Jour. Sci., 2d ser., vol. 2, 1816, pp. 125-131. s Boston Soc. Nat. Hist., Proc, vol. 2, 1846, pp. 95-96. 6 Philadelphia Acad. Nat. Sci., Jour., 2d aer., vol. 1, 1847, pp. 5-15. 'Ibid., pp. 16-17. 8 Am. Jour. Sci., 2d ser., vol. 1, 1816, pp. 209-221, 395-405 ; vol. 2, 1846, pp. 36-48, 124-12.5, 210-215, 309-400. Philadelphia Acad. Nat. Sci., Proc, vol. 3, 18^6, pp. 19-27 ; vol. 3, 1847, pp. 280-299. Philadelphia Acad. Nat. Sci., Jour., 2d ser., vol. 1, 1848, pp. 111-134. 9 Am. Jonr. Sci., 2d ser., vol. 2, 1846, p. 47. ^Philadelphia Acad. Nat. Sci., Jour,, 2d ser., vol.1, 1848, p. 129. ■' Ibid., Proc, vol. 3, 1846, p. 51. « Boston Soc. Nat. Hist., Proc.^ol. 2, 1840, p. 192. " Philadelphia Acad. Nat. Sci., Proc, vol. 4, 1848, pp. 95-107. "Ibid., Jour., 2d ser., vol 1, 1848, pp. 139-147 ; 1849, pp. 191-206. i» Am. Jour. Sei., 2d ser., vol. 1, 1846, pp. 38-42. 16 Boston Soc. Nat. Hist., Proc, vol. 2, 1846, pp. 123, 124. "Ibid., p. 193. " Am. Assoc. Adv. Sci., Proc, vol. 1, 1848, pp. 32-33; Report on theGeology of South Carolina, 1818, pp. 136,139-170,211. " Am. Jour. Sci., 2d ser., vol. 6, 1848, pp. 354-383. ™ Ibid., vol. 7, 1849, pp. 187-201. CLAUK] HISTORICAL SKETCH, ATLANTIC AND GULF COAST. 29 Eoetner, in 1849, published at Berne a general treatise upon Texas, in which he gives the first account of the occurrence of the Eocene iu that State. Fossils were found sufftciently similar to those of Olaiborue, Alabama, to justify him in considering the deposits of like age. Although discovered at only one locality, he expressed the opin- ion at that time that it was hardly probable that the Eocene was thus limited to one point, but doubtless existed as a continuous deposit across the State. He considered that the surface exposures were only prevented from being seen by overlying formations. During 1850 papers appeared on the geology and paleontology of the Atlantic Coast Eocene by Kavenel,i Euffln,^ G-ibbes,' Wyman,* Conrad,* and Holmes.* A year later, Tuomey, in a " Notice of the Geology of the Florida Keys, and of the Southern Coast of Florida,"' confirmed the observa- tions of Courad concerning the age of the Tampa Bay limestone, and showed its wider extension. In the same volume of the American Journal of Science, Prof. J. W. Bailey published a notice of " Silicifled Polythalamia in Florida," in which he speaks of large masses possessing all the mineralogical char- acters of flint, occurring in the white " orbitolite limestone," which, he says, is common throughout the portion of Florida between Tampa and Palatka. ' In 1850 Desor discussed the equivalence of the American Tertiary at a meeting of the Boston Society of Natural History. He agreed with Prof. Eogers as to the want of a complete correspondence of Americau and Europaan Tertiary, and also with regard to the absence of a close correlation between the American Tertiary of different epochs.' During the next few years contributions were made to the paleontol- ogy of the Eocene by Bouv6," Tuomey," Holmes,'^ and Conrad." Conrad,!* j^ ".Remarks on the Tertiary Strata of San Domingo and Vicksburg (Miss.)," states that a comparison of fossils from the two localities had resulted in the recognition of several identical forms, and from that circumstance he drew the conclusion that the strata were probably of the same age. In a later publication entitled " Observations on the Eocene deposit 'Am. Assoc. Adv. Sci., Proo., vol. 3, 1850, pp. 159-161. "Am. .Jonr. Sci., 2d ser., vol. 9, 1850, pp. 127-129. ' 'Philadelphia Acad. Nat. Soi., Jonr., 2d ser., vol. 1, 1850, pp. 299, 800. "Am. Jour. Sci., 2d ser., vol. 10, 1850, pp. 228-235. 'Philadelphia Acad. Nat. Sci., Jonr., 2a ser., vol. 2, 1850, pp. 39-41. 5Am. Assoc. Adv. Sci., Proc, vol. 3, 1850, pp. 201-204. 'Am. Jour. Sci., 2d ser., vol. 11, 1851, pp. 300-391. sibid., p. 86. 'Boston Soo.Nat. Hist., Proc, vol. 3, 1850, p, 247. "Ibid., vol. 4, 1851, pp. 2-4. "Philadelphia Acad. Nat. Soi., Proc, vol. 6, 1852, pp. 102-104. "Elliott Soc. Nat. Hist., Proc, vol. 1, 1853, p. 21. 'sphiladelphiatAoad. Nat. Sci., Proc, vol. 6, 1853, pp. 316-319, 320, 321, 448, 449 j vol. 7, 1854, pp. 29-31, vol. 7, 18S5, pp. 257-263, 265-268, 209 ; vol. 9, 1857, p. 166, "Ibid., vol. 6, 1852, pp. 198, 190, 30 THE EOCENE. [bull. 83. of JacksoD, Mississippi, etc."i the same author presents a table to "show the order of succession of Eocene groups." The Jackson group is placed between the Olaiborne and the Vicksburg, and the " orbitolite limestone " of St. Stephen's Blnflf is placed in the lower part of the Vicksburg series. Prom the fossils sent him Gourad came to the con- clusion that the Jackson deposits- contained no species in common witb those of Vicksburg, and very few with those of Olaiborne. During this time Wiuchell,^ Le Conte,^ Emmons,' Kogers,^ Safford,^ and McCrady' contributed the results of observations that relate wiiolly or in j)art to the stratigraphy of the eastern Eocene. During the decade 1850-60, while so much valuable information relative to the Eocene was accumulated by private industry, the State governments were not inattentive to the importance of geological in- vestigations of their territories. The State Geological Survey of New Jersey, under William EZitchell, published three annual reports for 1854, 1855, and 1856, in which the descriptions of the marls in the eastern and southern parts of the State were prepared by tbe assistant geologist, Geo. H. Cook. As a result of his investigations, he states in the first report that " there are three distinct beds of marl ," and that " the third bed includes the marls of Deal, Poplar, Shark Eiver, and Squankum ," localities that will receive later consideration. The second and third reports added nothing as to the taxonomic position of the upper marls, though the local stratigra- phy had been worked out in greater detail. Although accepting the conclusions of Vanuxem and Morton that the marls of the State were Cretaceous, he wisely says that " it is felt to be a matter of much im- portance to know as many as possible of the fossils found here. " In Maryland the State agricultural chemist published six reports between 1850-'68, but they are of slight importance from a geological standpoint. Prof. Emmons, in a report on the Geological Survey of North Car- olina, published in 1852, considers the Eocene at some length. The outliers in the central part of tbe State are referred to in connection with the more extensive deposits that occupy the eastern portions. In a subsequent report, published in 1858, the special features of the Eocene are treated in much greater detail, and many sections and new species of fossils are described.* During 1856-'60 the State geologist of South Carolina, Oscar M, Lieber, presented four annual reports to the general assembly, but nothing of importance was added to the earlier contributions of Euffin and Tuomey upon Eocene stratigraphy. > Pliiladelphia Acad. Nat. Soi., Proc, toL 7, 1865, pp. 257-203. 2 Am. Assoc. Adv. Sci., Proc, vol. 10, pt. 2, 1856, pp. 94-103. " Am. Joar. Soi., 2d ser., vol. 23, 1857, pp. 46-60. * Am. Assoc. Adv., Sci., Proc, vol. 11, pait 2, 1857, pp. 76-80. » Boston Soc. Nat Hist., Proc, vol. 7, 1859, pp. 60-64, « Am. Jour. Sci., 2d ser. vol. 27, 1859, pp. 363, 364. » Elliott Soc. Nat. Hist., Proc, vol. 1, 1859, pp. 282, 283, CLABK.] HISTORICAL SKETCH, ATLANTIC AND GULF COAST. 31 Prof. Tuomey, in the " First Biennial Eeport on tlie Geology of Ala- bama" (1850), considers the extent, structure, and stratigraphy of the earlier Tertiary of that State, and gives numerous typical sections and a list of fossils. A "second report, finished in 1855, but on ac- count of the death of the author not published until 1858, contaius considerable new*information and extended lists of fossils from well known localities. Wailes's "Eeport on the Agriculture and Geology of Mississippi" appeared in 1854. The work deals largely with the economic features of the deposits, but lists and figures of characteristic fossils are given, together with the local character of the beds in which they occur. Three years later a "Preliminary Eeport on the Geology and Agri- culture of the State of Mississippi, by L. Harper," was published, but very little of importance was added to the stratigraphy of the Eocene. A greatly expanded account of his geological observations in Texas is given by Prof. Eoemer in "Die Kreidebildungen von Texas," pub- lished in Bonn in 1852. The "First Eeport of the Geological and Agricultural Survey of Texas " was prepared by Dr. Shumard in 1859, but little attention is given in this work to the Tertiary, although reference is made to the lignite brown coal of the eastern and middle portions of the State. Nothing of importance was added to the earlier statements of Eoemer. Two reports upon the geology of Arkansas were published in 1858 and 1860 by D. D. Owen,, in which several occurrences of the Eocene, with characteristic fossils, are cited. But .slight attempt, however, was made at a delimitation of the Tertiary area. Safford's first and second biennial reports on the geology of Tennes- see, presented to the general assemblies of 1855 and 1857, contain a few references to " The Lignite group " which crosses the western por- tion of the State. The four large quarto volumes of the Kentucky Geological Survey that was prosecuted between the years 1854 to 1859 are devoted almost exclusively to a description of the economic products of the State. The Tertiary strata are barely referred to. Important contributions were made to the paleontology of the Eocene ' by Conrad,' Gabb,^ Whitfield,' and Marsh* during the next decade (1860-'70). An important paper by J. M. Safibrd, on the lignitic beds of the southern Tertiary, entitled "On the Cretaceous and Superior Forma- tions of west Tennessee," ^ appeared in the American Journal of Science 'PMliidelphia^cad. Nat. Sci., Jour., new ser., vol. 4, 1860, pp. 275-298. Philadelpbia Acad. Nat. Sci,, Procvol.li, 1862, pp. 284-291; ibid., vol. 16, 1864, pp. 211-214. Amer, Jonr. Conch., vol. 1, 1865, pp. 1-35, 137-141,142-149,210-212,213-215; vol. 2, 1806, jjp. 75-78,101-103,104-106; vol. 3, 1867, pp. 188-190. Phila- delphia Acad. Nat. Sci., Proc. vol. 17, 1865, pp. 73-75, 75, 184. ^Philadelphia Acad. Nat. Sci., Proc, vol. 13, 1861, pp. 367-372, .Jour., new ser., vol. 5, 1862, pp. 111-179. » Am. Jour. Conch., vol. 1, 1865, pp. 259-268. 1 Am. Jour. Sci., 2d ser. vol. 48, 1869, pp. 397-iOO. Am. Assoc. Adv. Sci., Proc,, vol. 18, 1869, pp. 227-230. « Xbid.., vol. 37, 1864, pp. 360-373. 32 THE EOCENE. [bull. 83. for 1864. In this article the lignite beds of the Eocene are divided into the Porters Ore'ek gronp (lower) and the Orange Sand or La Grange group (upper). Overlying these is placed a third group, called the Bluff Lignite, that at that time was provisionally considered Tertiary by Safford. In an article by Conrad " On the Eocene Lignite "Formation of the United States," ' the upper marl of the Upper Marl Bed of New Jersey is correlated with the Brandon (Vermont) and southern lignites. Thepres- ence of such a horizon between Cretaceous and Eocene is claimed in this paper on the authority of Vanuxem and Tuomey to occur in South Carolina and Alabama, and upon that of Durand^ and Harper in Mary- land and Mississippi. Conrad ' proposed, in 1866, the name " Shell Bluff group " for certain strata of the Eoceue he considered characterized by Ostrea georgiana, an oyster found at Shell Bluff, on the Savannah Elver, as well as "at Vicksburg * * *^ in the lower part of the bluff' below the Orbito- lite limestone of the Jackson group." In a communication in the succeeding volume of the American Jour- nal of Science, Hilgard* takes exception to Conrad's statements and conclusions ui)on this point. In this article he says that the " Orbitolite limestone of the Jackson group " is erroneous, as he knows of no case where Orhitoides are found below the Vicksburg strata. He further casts doubt upon the occur- rence of Ostrea georgiana at Vicksburg. In conclusion, he says that the " Shell Bluff group " is above the Jackson and probably identical with his own "Eed Bluff group." In an article " On the Tertiary Formations of Mississippi and Ala- biama,"^ the same writer says : I can not, therefore, ■with, the lights before me, agree to the propriety of distinguish- ing as separate divisions the Orhitoides limestone aud the Vicksburg gronp of fossils. * * Even the occurrence of a different species of Orhitoides {0. mipera, Con.) aX Vickburg can not alter the case, for the undoubted 0. MantelU occurs there also in the solid rock, and there are few of the characteristic fossils of the Vicksburg profile vfhich I have not on some occasions found side by side with the 0. ManteUi and its companions, the Pecten Poiilsoni and Ostrea vicksburgensis. He states further that Lyell and Hale were the only two observers who had hitherto comprehended the proper position of the " Zeuglodon bed " in relation to the " Orhitoides rock." In "Notes on American Possiliferous strata,"^ published in 1869, Conrad presents some facts relative to the section at Shark Eiver, New Jersey, and gives an account of the more interesting fossil remains found there. ' Philadelphia Acad. Nat. Sci., Proc, vol. 17, 1865, pp. 70-73. Am. Jonr. Sci., Sd ser., vol. 40, 1865, pp. 265-268. ^Philadelphia College of Pharmacy, Jour., vol. 5, 1834, p. 12. ' Am. Jour. Sci., 2d scr., toI. 41, 1868, p. 96. 4Ibid., vol. 42, 1806, pp. 68-70. «Ibid., vol. 43, 1867, pp. 29-41. » Ibid., vol. 47, 18fi9, pp. 358-364. CLARK.] HISTORICAL SKETCH, ATLANTIC AND GUIrF COAST. 33 During the period 1860 to 1870 the State governmeuts interested themselves but little in geological surveys. The war broke up those that did exist, excepting in New Jersey, and the inauguration of new ones had hardly begun at the close of the decade. In Few Jersey George H. Cook, now appointed State geologist, pros- ecuted the survey of that State vigorously, and presented a report of progress for 1833, which was followed by yearly reports thereafter. In the report for 1863 he states that " a section has been surveyed across the State from the mouth of Shark Eiver Inlet, on the Atlantic shore, to the Delaware Water Gap." The areal distribution of the Eocene, together with certain of its characteristics, is described, though its tax- onomic position was but partially appreciated. In the report for 1864 an analysis of the Eocene marl is given, together with the most im- portant localities at which it is exposed. Nothing further of importance upon Eocene geology appeared until the publication of the " Geology of New Jersey, " in 1868, in which the boundaries, structure, and fossil re- mains of the Upper Marl Bed receive careful and detailed treatment. In Maryland a geological survey was started under Philip T. Tyson, who published reports in 1860 and 1862. The sudden termination of the survey, after the appearance of the second report, prevented the publication of a large amount of iraportantdatathat would have thrown much light upon the stratigraphy of the Maryland Eocene. Maury's " Physical Survey of Virginia," which appeared in 1869, con- tains several references to the stratigraphy of the Eocene. The later reports of Emmons at the opening of this decade, and the earlier reports of Kerr, at its close, present practically nothing new on the Eocene geology of North Carolina. In the "First Report to the Cotton Planters' Convention of Georgia on the Agricultural Resources of Georgia" (1860), the author, Joseph Jones, gives an account of " the Tertiary limeformations " of the State. Many localities are cited where fossils had been found, and the general character of the strata in Burke and Washington Counties is dwelt upon. Of the geological work performed under State authority during this period, the investigations of Hilgard in Mississippi and Louisiana de- serve special mention. In the former his " Report on the Geology and Agriculture of the State of Mississippi (1860) " has been by far the most Important contribution to its geology. In this report the early Tertiary is divided into (1) Great Northern Lignite; (2) Claiborne; (a) siliceous, (b) calcareous ; (3) Jackson ; (4) Vicksburg. The most detailed obser- vations are there recorded, and from a comparative study of the fossils collected a correlation of the leading horizons of the Eocene is success- fully accomplished. Two short reports on the geology of Louisiana by the same author appeared sit the close of the decade. The second or final report was not published, however, until 1873, The stratigraphy of the Eocene is Bull, 83 3 34 THE EOCENE. [bull. 83. not dwelt upon very fully in these reports, but the author's conclusions are valuable from his intiuiate kuowledge of the same formations in Mississippi. Saftbrd's " Geology of Tennessee " (1869), contains much of importance upon the Teritary of that State. The lignite deposits are divided into (1) Porters Creek group (provisional); (2) Orange Sand or La Grange group ; (3) Bluff Liguite group. Numerous sections and lists of plant remains are given, and the gen- eral limits of the Eocene are designated. The second of Owen's reports on the geology of Arkansas (1860), although it appeared at the beginning of this decade, has been earlier referred to. A valuable classiflcatory list of Eocene fossils was published by Conrad in 1866, in the Smithsonian Miscellaneous Collections.^ Some most valuable contributions to the history of the life of the Eocene period, which includes the descriptions of many new species, were presented by Conrad^, Marsh', Cope*, Lesquereux^, and Heilprin^, during the decade 1870-'80. In an article on the " Geological History of the Gulf of Mexico,"' read before the American Association for the Advancement of Science, Hilgard presents some important couclusions as to the age of the lig- nite deposits of the Gulf States. He says : So far, iideed, from considering the predomineiitly lignitiferous area as represent- ing a period distinct from the older marine Tertiary, I have little doubt that the larger portion, if not all, of the beds I have heretofore designated as the northern liguitic (and Flatwood clay) group (La Grange and Porter's Creek groups of Saf- ford) are the strict equivalents in time of the oldest marine beds observed in South Carolina and Alabama, and designated by Tuomey as the Buhrstone group ("Sili- ceous Claiborne " of my Mississippi Report). He adds, further, that the lignitic facies is but slightly developed in Alabama as compared with the upper portion of the Mississippi Em- bayment. " In Arkansas, nevertheless, small marine beds are more liberally interspersed among the lignitic clays than is the case east of the Mississippi." Articles by Shaler', Hitchcock^, Leidy'", Vogdes^', Heinrich^^, and Fontaine", contain references to early Tertiary stratigraphy that are of ' Smittisonian Misc. Coll., vol. 7, 1866, art. 6, pp. 1-41. 2 Am. Jour. Sci., 3cl ser., vol. 1, 1871, pp. 46P, 469 ; Piiiladelpliia Acad. Nat. Sci., Proc, vol. 24, 1872, pp. 50-56, 216, 217. 3 Am. Apsoo. Adv. Sci., Proc, vol. 26, 1877, pp. 2U-268. •" Am. Phil. Soc, Proc;., vol. 11, 1870, pp. 285-294 ; vol. 17, 1877, pp. 82-84. 'Tbid., Trans., new ser., vol 13, 1870, pp. 411-433. « Philadelpliia Acad. Nat. Sci., Proc, vol. 31, 1879, pp. 211-2!'6, 217-225. ' Am. Assoc Adv. Sci., Proc, vol. 20, 1871, pp 222-236 ; Am. Jonr. Sci., 31 ser., vol. 2, 1871, pp. 391-401. » Boston Soc Nat. History, Proc, vol. 13, 1870, pp. 222-236. 'Am. Assoc. Adv. Sci., Proc, vol. 22, pt. 2, 1873, pp. 131, 132. '» Philadelphia Acad. Nat. Soi., Jonr., new ser., vol. 8, pp. 209-202. "Am. Jour. Soi., 3d ser., vol. 10, 1878, pp. 69, 70. " Am. Inst. Min. Bng., Trans., vol. 6, 1878, pp. 227-274. " Am. Jour. Sci., 3d ser., vol. 17, 1879, pp. 25-39, 351-157, 229-239. CLARK.] HISTORICAL SKETCH, ATLANTIC AND GULF COAST. 35 value in conjunctiou with the more extended accounts of the same localities elsewhere published and referred to. A work that contains much scattered information in regard to the Eocene is Macfarlane's "American Geological feailroad Guide," that first appeared in 1879. A second edition was published iu 1890. During the decade (1870-'80) a marlied increase in activity in geolog- ical work was manifested on the part of the States. In New Jersey annual reports were published by Prof. Cook, though little of importance was added to the knowledge of the Eocene. "Virginia, a geographical and political summary," by Jed. Hotch- kiss, is the title of a book that appeared in 1876. It contams a brief summary of the Tertiary geology of that State and several type sec- tions of the Eocene. Most of the author's conclusions are identical with those in the earlier reports of Rogers. The State geologist of North Carolina, W. 0. Kerr, published sev- eral reports during this period, the most important of which is a " Re- port of the Geological Survey of North Carolina, vol. 1, 1875," in which the Eocene is stated as limited by the Neuse and Cape Fear Eivers on the north and south respectively, a few isolated outcrops alone ex- cepted. An appendix to this report contains an article by Conrad on the Tertiary, with descrii)tions of new species of fossils. Several works of a geological character appeared at this time bear- ing upon the Eocene of Georgia, Three short reports by the State geologist, George Little, were published in 1875, 1876, and 1878. The "Geology and Mineralogy of Georgia" (1871), by M. F. Stevenson, contains an outline of the main features of the Eocene, which were later restated by T. P. Janes in his "Handbook of the State of Georgia" (1876.) The earlier publications of the present geological survey of Ala- bama, beginning in 1875, contain nothing upon the Eocene. In an " Outline of the Geology of Alabama," by E. A. Smith, State Geolo- gist, in " Berney's Handbook of Alabama " (1878), the Eocene is divided into: !:?i:S^S'S upper Eoceue. E'.SoTneS Middle Eocene. 1. Lignitio and Buhrstone Lower Eocene. The characteristic features of each group are given, and in a general way its boundaries. Three annual reports on the geology of Louisiana were published iu the early part of this decade by F. V. Hopkins. Much attention is given to the Eocene, particularly to the Jackson and Vioksburg groups, and lists of fossils are appended. Two reports of the geological and agricultural survey of Texas were presented by S. B. Buckley in 1874 and 1876. They added little of value to previously existing knowledge of the Eocene. Prof. N. S. Shaler published four reports upon the geology of Keu- 36 THE EOCENE. [bull. 83. tuckj: that contain meager reference to the Eocene strata of the western portion of the State. It is hardly necessary to consider in detail the literature of the last decade (1880-'90), as the results of the investigations of that period will be incorporated in the subseqent portions of this report. In passing, however, it is necessary to refer to a discussion, precipitated by Dr. Otto Meyer, in regard to the stratigraphical position of the various members of the early Tertiary of the Gulf States. Chiefly from a study of the fossils, but likewise from investigations in the field, Meyer came to the conclusion that the order of succession of the various Tertiary formations is just the reverse of that generally accepted, viz: That the Vicksburg beds occupy the position accorded to the Claiborne, and that the order, beginning with the lowest, is (1) Vicksburg, (2) Jackson, (3) Claiborne, instead of (1) Claiborne, (2) Jackson, (3) Vicksburg, as first made out by Lyell and accepted by all subsequent investigators. Meyer's position was attacked by Hilgard, Smith, Heilprin, and others, whose long experience in the study of the southern Tertiary showed the fallacy of such conclusions. It is not necessary here to enter into the details of the discussion, or present more at length the grounds upon which Meyer based his argument. Most of the articles appeared in the American Journal of Science^ and Science * in 1885-'86. Among the contributors upon Eocene geology during this decade are Heilprin,' Smith,'' Hilgard,^ Aldrich,^ Johnson,' Meyer,' Kerr,' Gardner,!" jj^wn Me\],'^ White," Winchell,'* Hill,i= Miller," Uhler," Campbell,!" Langdon," McGee,^° Darton," and the" writer of this paper.^* ■ Am, Jour. Soi., 3a ser., vol. 29, :8S5, pp. 457-468: vol. 3»,1885,pp. 60-72,266-269, 270-275, 300-308, 421-435 j vol. 33, 1680, pp. 20-25. ^Science, vol. 5, 1883, pp. 475, 470 ; vol. 6, 1885, pp. 44, 83, 143, 144 ; vol. 7, 1886, p. 11. 3 PbiladelpMa Acad. Nat. Sci,. Proo . vol. 32, 1880, pp. 20-33, 361-375 ; vol. 33, 1881, pp. 151-159, 416-422, 423-428,444-447,448-453; vol. 34, 1882, pp. 150-186, 189-193; vol.36, 1884, pp. 321-322; vol. 39, 1887, pp. 314-322; SciOQCB, vol. 5, 1885, pp. 475, 476 ; Wagner Freelnst. Sci., Trans., vol. 1, 1887, pp 1-134; U.S. Ge- ological Survey, Fourth Aon. Report, 1882-'83, Appendix I, pp. 309-316. ■•Am. Jour. Sci., 3d ser., vol. 21, 1881, pp. 293-309; Science, vol. 5, 1885, pp. 376, 395-396; Am. Gool., vol. 2, 1888, pp. 269-284; U. S. Geol. Surv., Bull. K"o. 43, 1887. ^Am.Jour. Sci.,3d8er., vol. 22, 1881, pp. 58-65. sCinoinnati Soc. Nat. Hist. Jour., vol. 8, 1885, pp. 145-153, 2-56, 257 ; vol. 9, 1 886, pp. 104-114. ' Science, vol. 2, 1883, p. 777 ; Am. Jour. Soi., 8d ser., vol. 36, 1888, pp. 230-236. » Philadelplaia Acad. Nat. Sci., Proc, vol. 36,1884, pp, 10H12; vol. 39,1887, p. 51; Bericht iiber d. Sonck. Naturf. Gesells. in Franltfurt, a. M., 1887, pp. 1-20. 'Am. Nat., vol. 19, L885, p. 69 ; Elisha Mitchell Sci. Soc, Proc, vol. 2, 1884-'85, pp. 79-84, 86-90. "Brit. Assoc, Kept. 54th meet., 1884, pp. 739-741 ; Geol. Mag., new ser., decade 3, vol. 1, 1884, pp. 492- 506. " Am. Jour. Sci., 3d ser., vol. 34, 1887, pp. 161-170. 12 Am. Inst. Min. Eng., Trans., vol 8, 1880, pp. 304-3J3. 13 Washington Biol. Soc, Proc, vol 3, 1885, pp. 1-20 ; Am. Jour. Sci., 3d ser., vol. 35, 1888, pp. 432-438. i< Science, vol. 3, 1884. p. 32. "IT. S. Geol. Surv., Ball. 45, 1887. 'sNorth American Mesozoic and Cenozoic Geology and Paleontology, 1881. 1' Maryland Acad. Soi., Trans, vol. 1, 1888-'90, pp. 10-32, 45-72, 97-lOt. >»Am. Jour. Sci., 3d ser., vol. 31, 1886, pp. 193-202. " Ibid., vol. 31, 1880, pp. 202-209 ; Geol. Soc. America, Bull., vol. 2, 1891, pp. 687-605. ™ Ibid., vol. 35, 1888, pp. 120-143, 328-330, 307-368, 44B-4C0 ; Geol. Soc America, Bull., vol. 2, 1891, pp. 2-6. '" Geol. Soc. America, Bull., vol. 2, 1891, pp. 431-450 2«lbid., vol. 1,1890, pp. 537-540; Johns Hopkins University, Circulars, vol. 7, 1887, pp. 65-57; vol.9, 1890, pp. 69-71 ; vol. 10, 1891, pp. 105-108. CLAKK.i HISTORICAL SKETCH, ATLANTIC AND GULF COAST. 37 lu 1881 Heilprin published the most important trealisei that has appeared upon the general features of Boceuce stratigraphy. la the main the work embodies the points presented in numerous articles in the Proceedings of the Academy of Natural Sciences of Philadelphia, and referred to above. It has thus far been the only attempt at a succinct treatment of the subject of Tertiary geology, and the conclu- sions at which Prof. Heilprin has arrived are most valuable, and will often find place in the pages of this report. Surveys were prosecuted in many of the States during this decade. In New Jersey Prof. Cook, the State geologist, published annual re- ports. Under the same auspices a memoir by Prof. Whitfield on the Brachiopoda and Lamellibranchiata, appeared, in which the Eocene species from Monmouth County are figured and described. In the Oarolinas two works of a general character that include chap- ters upon geology appeared in 1883; the first, entitled a "Handbook of the State of North Carolina," was published under the direction of the board of agriculture ; the second, " South Carolina Eesources and Population, Institutions and Industries," prepared by H. Hammond. The municipal report of the city of Charleston for 1884 contains an article on artesian wells, in which a detaik-d section is given of the geological strata beneath the city, to a depth of nearly 2,000 feet. " The Commonwealth of Georgia" (1885), by J. T. Henderson, eives the boundaries and general character of the Eocene belt. The Florida State geological survey, under J. Kost, has published but little on the older Tertiary limestones. In Alabama the State Geological Survey has been ably prosecuted under Prof. E. A. Smith, and the reports of the survey, together with Bulletin 43 of the U. S. Geological Survey, afford a detailed account of the most important sections of the Eocene of that State. In Arkansas the State geological survey published in 1889 a report on the Neozoic formations by Prof. Eobert T. Hill, in which the Eocene is fully considered. The present Texas geological survey has presented in its first annual report for 1889 a preliminary statement by E. A. F. Penrose, jr., con- cerning the Gulf Tertiary area in which the stratigraphical relations of the Eocene are discussed. A critical examination of the literature, a brief summary of which has been given, will convince one that although much has already been done, far more exhaustive and systematic investigations must be made before our knowledge of the Eocene formation of the Atlantic and Gulf coast region approaches in any degree to completeness. ^ Contributions to the Tertiary Geology and Paleontology of the United States, Philadelphia, the anthoi, 1881, 4to, 117 pp. and map. 38 THE EOCENE. [buli- 83. GENERAL BOUNDARIES. The Eocene of the Atlantic coast extends as a narrow band inter- mittingly appearing and disappearing across the States of New Jersey, Delaware, Maryland, and Virginia, and thence with an increase in width of surface exposure across the Garolinas and Georgia into Florida, Within the Gulf States it outcrops over a still greater area, extending from Florida across central Alabama and Mississippi, while in the latter a northward extension covers much of the northern portion of that State together with parts of eastern Tennessee and Kentucky and southern Illinois. Upon the western bank of the Mississippi the Eocene is found in southeastern Missouri, and much more widely represented over eastern and southern Arkansas and western Louisiana, while a band of considerable width extends across Texas in a southwesterly direc- tion to the Mexican border. ' Throughout the Atlantic and Gulf States the exposures of Eocene are separated from the coast line by a region of greater or less width, in which later Tertiary and post-Tertiary deposits constitute the land surface. On the other hand, the Eocene seldom comes in contact with the older rocks of the Piedmont Plateau, but is in nearly all cases separated from them by an area of Mesozoic formations. Occupying as it does a more or less central position in the coastal plain, the Eocene, after its first appearance in eastern New Jersey near the coast, maintains a distance of from 50 to 75 miles from the same through Maryland and Virginia. Beginning with a width of exposure in eastern New Jersey of less than 5 miles, it broadens in Maryland and Virginia to 20 or 25. This is very greatly increased in North Carolina, where many isolated outcrops are found scattered from Wilmington and New Berne to near Raleigh, the first scarcely 10 miles from the coast, the last considerably over 100 miles. In South Carolina the different divisions of the Eocene are found over quite as wide an area, and in the vicinity of Charleston approach within a few miles of the sea. Less is known of its boundaries in Georgia and Florida, but that it is widely extended and in the former State reaches over 150 miles from the coast is recognized. The careful study made of the Eocene in Alabama and Mississippi make it possible to speak with some accuracy as to its limits. Extending in a northwesterly direction across the southern and central portions of these States, its distance at the boundary between them is not far from 100 miles from the Gulf, while its northward extension in the latter State, to form the Mississippi embayment, reaches across Tennessee and Kentucky into Illinois, with a width of exposure north of the Gulf and east of the Mississippi Eiver of from 50 to over 100 miles. The region of the Eocene extending from Missouri south- westward through Arkansas, Louisiana, and Texas, although a con- tinuation of the eastern belt is yet separated from it and the Gulf by a wide area of more recent deposits that have been formed by the Missis- CLAKK.) GENERAL STRATIGRAPHICAL RELATIONS. 39 sippi and other streams reacUiug the coast. The width of the outcrop in Louisiana and Arkansas is quite 150 miles, which again becomes con- tracted as eastern central Texas is reached. In the next chapter a more detailed discussion of the geographical distribution of the deposits in the several States will be found. STRATIGRAPHICAL AND PALEONTOLOGICAL CHARACTERISTICS. GENERAL RBMARKS. The Eocene constitutes a well defined stratigraphical and paleon- .tological unit in the series of late Mesozoic and Oenozoio deposits of the coastal plain. A brief sketch of the succession of events during the formation of that area will aid in acquiring a clear idea of the rela- tionship of the Eocene to the other members of that series. At about the opening of the Cretaceous period, or perhaps somewhat earlier, a great depression of the continent took i^lace along the Atlan- tic and Gulf borders, by which the coast line was moved far Inland against the buttress of Archean and Paleozoic strata. The gravels, sands, and clays of this basal formation have received different names in the different regions in which they are represented — upon the At- lantic coast the Potomac, on the eastern Gulf coast the Tuscaloosa, and on the western Gulf the Trinity formation. In the western Gulf region the Trinity formation is succeeded by the Comanche series, character- ized by limestones and a fauna that denotes a deep infralittoral origin. A marked continental elevation occurred previous to the great sub- sidence that opened the Upper Cretaceous epoch throughout the At- lantic and Gulf coast region. The deposits of this age, largely green- sand marls on the Atlantic coast and marls and limestone on the Gulf border, are the basement beds upon which the Eocene stratahave been chiefly laid, though these are also found unconformably overlying the earlier horizons in local areas. The materials of which the Eocene deposits are formed were mainly derived from the softer beds of the Cretaceous series, although the continental area to thenorth and west supplied a considerable admixture of sand and clay. The deeper water deposits of late Eocene time were, however, largely the accumulations of organic remains in 'a sea only periodically exposed to the inroads of land-derived materials. Through- out the Gulf area and at times locally represented on the Atlantic coast are shore deposits of lignitic character and in part at least of brackish water origin, that attain great thickness in the Mississippi embay- ment, and in the southwest appear at different horizons to the top of the Eocene. Unconformably overlying the Eocene with its varied development in brackish and marine deposits, is the Neocene which likewise occurs under very different facies in different portions of the coastal area. Composed largely of sands, clays, and marls that have been in part 40 THE EOCENE. [bull 83. derived from the Eoceue itself, it occupies a band of varying breadth upon the shoreward side of the deposits of that horizon. Spread widely over nearly the entire area of the coastal plain are post- Tertiary deposits of varied origin, the details of which it is un- necessary to discuss here, that bury, almost completely, the Oretaceo- Tertiary series. Due to the slight elevation of the region above sea level and the com- paratively slight inroads that have been made into the surface covering by denudation since their deposition,- the outcrops of the pre-Quater- iiary series are confined chiefly to the channels of the rivers and their larger tributaries. The strata that have just been described as enter- ing into the formation of the coastal plain are approximately horizontal, with a dip of a few feet to the mile toward the east on the Atlantic coast and toward the south on the Gulf border. Few disturbances of the strata have occurred throughout the territory, and only locally have the beds shown any change from the original condition of their deposition. When search is made in the literature for data upon which to con- struct a typical section of Eocene strata for the Atlantic and Gulf coast region the contradictory nature of the material at hand renders the consummation of the task difficult and the results doubtful. The Eocene is so varied in its facies in different portions of the area that it becomes often perplexing to determine to which division of the series a particular deposit belongs. As the worli has been prosecuted lai'gely under State supervision, and as the State geologists have employed chiefly local terms in the designation of the different horizons, it is thought advisable to consider the stratigraphy of each State by itself, and subsequently to endeavor to correlate, so far as may be, the different divisions. Such treatment is but seldom warranted on stratigrai^hical grounds, yet the character of the literature makes it in this case the only feasible method. A consideration of the subject by provinces is much more to be desired, but this would be hazardous with our present meager knowledge of the area. A pfovisional establishment of provinces is, however, attempted in a later chapter. KEW JEESEY. The green-sand marls of Kew Jersey early attracted the attention of geologists, and the similarity of the fossils to those of the Cretaceous of Europe was soon recognized. That horizons Other than the Creta- ceous were represented in the marl series was not at first entertained, and even after the upper beds were shown to contain Eocene fossils their conformity to the Cretaceous marls was for a still longer period considered probable. Conrad,' in 1848, first referred the marls of the ui^per portion of the Upper Marl Bed near Long Branch to the Eocene, 'Philadelphia Acad. Nat. Sci. Jour., 2d ser., vol. 1, 1848, p. 129. o'-AKK.J NEW JERSEY. 41 and Cook,i iu 1883, first proved by detailed field woik tbe uiicoui'onnity of that formatiou to the Cretaceous. The paleoutologicul investigii- tious of Whitfield have further substantiated the results of Conrad and Cook. From the standpoint of stratigraphy the Eocene of New Jersey does not form a prominent feature iu the coastal deposits. The conditions for its formation were not markedly different from those in other portions of the marl series, so that sti ucturally the dissimilarities are not con- spicuous. Furthermore, the inconsiderable thickness of the deposits renders the geographical distribution limited. Although the dip has been estimated to be only 25 feet '' to the mile, it soon carries the strata ' below sea level in a country so slightly elevated above tide as this por- tion of the coastal plain. It is probable that the Eocene extends as an unbroken band from northeast to southwest across theStafe, although its surface continuity is frequently interrupted by the covering of more recent deposits. These toward the south acquire considerable thickness. The most northern exposure is on Deal Beach, where numerous pits have been sunk into the marl near tide water. Several other localities are found in Monmouth County, particularly that of Shark Eiver, the best known of all, and isolated exposures near Farmingdale, Squankum, and neighboring places. To the southeast of these localities an almost continuous band of the Upper Marl Beds is found extending from near New Egypt, Ocean County, across Burlington County to near Clemen- ton in Camden County. A continuation of this belt, beginning at Deal and extending to Clementon, would reach the Delaware Kiver not far from Salem, but to the southwest of Clementon it is buried from sight by later deposits. The stratigraphical sequence of deposits iu the Upper Marl Bed, as established by the late Prof. Cook, State geologist, is as follows : t Blue Marl Eocene. Upper Marl^ed ^AshMarl.. > Prpt^ippmi., ( GreenMarl5 Oretaceoiis. He thus describes the Blue Marl : The Blue Marl. — This layer lies directly upon the Ash Marl, without any well marked line of division, and it is terminated above by surface sand and loam, or by what is called rotten stone ; it is 11 feet thick ; it is a mixture of green sand and light- colored earth : the upperS or 3 feet are quite hard aud stony. It lies unconformably on the layers beneath ; its fossils are quite distinct and are pronounced by paleontol- ogists to be of the Eocene division of the Tertiary age.^ The stratigraphical and paleontological individuality of the New Jersey Eocene thus clearly stated by Cook has been recognized by many other geologists who have investigated the strata. The fossils, although varying in a marked degree from those of the preceding deposits of the marl series, still lack the more characteristic • Geol. Snrr. New Jersey, Ann. Kept., 1883, pp. 13-19. ^ Ibid., p. 19. 'Geology of New Jersey, 1868, p. 275 ; reprinted in &eol. Sarv. New Jersey, Ana. Eept., 1886, p. 182. 42 THE EOCENE. (BULL. 83. forms found in the Eocene to the south. Such tyi>ical species as Ostrea compressirostra, Ostrea seUwformis, Cucullcea gigantea, Gardita planicosta, and Turritella Mortoni are wanting. The important contri- butions (published and in press) to the paleontology of the Ifew Jersey Cretaceous and Eocene by Prof. E. P. Whitfield, give the following Eocene species from the Blue Marl of the Upper Marl Bed : LamellibrancMata. Ostrea glauconoides Whitfield. llnguafelis Whitfield. Pecten Kneiskerni Conrad. Eigbyi Whitfield. Avicula annosa Conrad. Nuoula circe Whitfield. Nucnlana albaria Conrad (Yoldia pro- . texta Conrad). Nucularia secunda Whitfield. Axinea Conradi Whitfield. Astarfce castanella Whitfield (Crassina veta Conrad). planimarginata Whitfield. Cardita perantiqua Conrad (Cardita sub- quadrata Gabb). Brittoni Whitfield. Crassatella alta Conrad. obliquata Whitfield. Protocardium cnrtum Conrad. Caryatis ovalis Whitfield (Caryatis dela- warensis Conrad). Veleda equilatera Whitfield. Corbula (Keeera) nasntoides Whitfield. Nesera sequivalvis Whitfield. Parapholas Kneiskerni Whitfield. Teredo emacerata Whitfield. Gloasophora. Leptomaria gigantea Whitfield. pergranosa Whitfield. perlata Conrad sp. Arehitectonica annosa Conrad. ■' Natica globulella Whitfield. Xenophora lapiferens Whitfield. Scalaria tenuilirata Whitfield. Mesalia elongata Whitfield. Calyptophorus vetnsta Conrad. Ehlnocantha [?] Conradi Whitfield. Cyprsea sabuloroides Whitfield. Cassidaria carinata Lamarck, Ficus penitas Conrad. Triton eocense Whitfield. Psendoliva vetusta Conrad. Fusus angnlaris Whitfield. eocenicns Whitfield. pauoicostatus Whitfield. perobesus Whitfield. pluricostatus Whitfield. (Neptunea) hector Whitfield. var. umltilineatus Whitfield, staniinea Conrad. (Urosalpinx) inulticostatuH Whitfield. Trematofusus venustus Wh itfield. Clavella raphanoides Conrad. Fasciolaria hercnles Whitfield. propinqua Whitfield. Sanisoni Whitfield. Voliita Newcombiana Whitfield. parvula Whitfield. perelevata Whitfield. soaphoides Whitfield. vesta Whitfield. lelia Whitfield. Caricella ponderosa Whitfield. pyruloides Conrad. Volntilithes cancellata Whitfield. Say ana Conrad. Murex (Pleuronotus ?) levivaricosa Whit- field. Cancellariarudis Whitfield. Pleurotoma surculiformis Whitfield. regularicostata Whitfield. (Surcula) altispira Whitfield, perobesa Whitfield. Surculites arenosa Conrad. oadaverosa Whitfield. curta Whitfield. Couussnbsanridens Whitfield. Actseon prisca Conrad. (Tornatiua) lata Conrad. Wetherelli Lea. C^halopoda. Nautilus Cookana Whitfield. Aturia Vanuxeml Conrad. oi-AEK.] DELAWARE. 43 In addition to the invertebrate fossils described by Courad and Whit- field, Marsh* and Cope^ have added a few vertebrate forms. Mammalia Siis. sp Monmouth Co. ( Dmophis littoralis Cope . . ., Shark River. Reptilia < halidanns Cope Sqnankum. ( grandis Marsh Shark River. f Myliobatis glottoidos Cope Farmingdale. I reotidens Cope Harrisonville. I biscalus Marsh Monmouth Co. Pisces <{ Coelorhynchus acus Cope Farmingdale. Histiophoriis parvulus Marsh Sqxiankuin. Embalorynchus Kiunei Marsh Squanknm. ^Phyllodus elegans Marsh Farmingdale. DELAWARE. Until the recent investigations of Darton' no positive evidence had been adduced of the occurrence of Eocene within the limit s of the State of Delaware, although Heilprin in his " Contributions to tlie Tertiary Geology and Paleontology of the United States " says : No reasonable doubt can be entertained as to its existence there (although possibly entirely obscured by the newer Miocene deposits) as a direct continuation of, or con- nection between, the belts developed in Maryland and New Jersey. Booth^ mentions the occurrence as far north as Old Duck Creek of Tertiary fossils which, from their description, must be Ifeocene, while Chester's^ investigations show that the Cretaceous is found somewhat to the south of Appoquinimink Creek. The intervening country, at most 6 miles in breadth, has been hith- erto doubtfully referred to the Eocene. Darton, by the recent discov- ery of several characteristic Eocene fossils, among them Gardita plani- costa, has proved beyond doubt that surface exposures of Eocene strata occur within this area. The characteristic greenish gray and red sand- stone that is typical for the more northern exposures of the Maryland Eocene has been recognized at numerous localities. The lithological and paleontological features of the Delaware Eocene ally it so closely with the Maryland representatives of this horizon, of which it is, in fact, only the northward prolongation, that a considera- tion of its relations will be deferred until the Maryland strata are dis- cussed. MARYLAND. The Eocene of Maryland is much more extensively developed than in New Jersey and Delaware and becomes for the first time a marked structural feature in the stratigraphy of the coastal plain. This fact, together with the great number and excellent state of preservation of • Am. Jour. Soi., 2d eer., vol. 48, 1869, pp. 397-400 ; Am. Asaoo. Adv., Soi., Proc, vol. 18, 1809, pp. 227-230. ' Philadelphia Acad. Ifat. Soi., Proc, vol. 20, 1868, pp. 234-235 ; Am. Phil. Soc, Proc, vol. 11, 1870, pp. 285-294. 2 Geol. Soc America Bull., vol. 2, 1891, pp. 441, 442. « Memoir of the Geological Siirvey of the State of Delaware, 1841, pp. 18, 81, 84. •Proc Acad. Nat. Soi., PhiUdelphia, vol. 36, 1884, pp. 249-258. 44 THE EOCENE. [bull. 83. the fossils, early attracted the attention of geologists. Although the valuable contributions of Finch^ and Say'' in 1824 included references to the MarylandTertiary, the first really important geological inferences, drawn from a study of the organic remains, were made by Conrad^ in the Journal of the Academy of Natural Sciences of Philadelphia for 1830. Many articles by the same author upon the Maryland Tertiary followed in subsequent years, and today the contributions of Conrad remain the most' exhaustive that we have upon the Eocene of the State. The more recent articles of Tyson, TJhler, Barton,* Heilprln and the writer of this bulletin have added many new facts, but there is much to be done before all the problems presented by the Eocene of Maryland will be fully solved. The Eocene deposits extend as a nearly unbroken belt from the Dela- ware line to the Potomac River, and are found in Cecil, Kent, Queen Anne, Anne Arundel, Prince George, and Charles counties. The strike is approximately northeast and southwest ; the dip 20 to 30 feet in the mile toward the southeast. The breadth of outcrop upon the eastern shore of the Chesapeake is scarcely 5 miles at the head of the Sassafras Eiver, but gradually expands toward the southwest until upon the west- ern shore it is in jilaces more than 25 miles wide. The lithological character of the rocks is remarkably persistent. The typical deposit is a green-sand marl, which may, however, by chemical changes, lose its characteristic green color, and by the deposition of a greater or less amount of hydrous iron oxide be found as an incoherent red sand or firm red or brown sandstone. To this is added at times a siliceous cement that produces a firm siliceous sandstone, from which generally most of the carbonate of lime has been removed in solution, so that the organic forms are found only in the shape of casts. The green- sand type is chiefly confined to the southwestern portion of the area in Charles and Prince George counties, where the deposits overlying the Eocene attain their greatest thickness. In Anne Arundel County and on the eastern shore of the Chesapeake the Eocene is less deeply buried and the strata are more thoroughly weathered, affording greenish gray or red sands and at times bands of firm sandstone. No widespread division of the series into different horizons is indi- cated upon lithological grounds, as the variations in composition are apparently due to subsequent chemical changes rather than to origiual deposition. It is likewise impossible with our present imperfect knowl- edge of the Eocene fauna to attempt to establish defiuite horizons upon such a basis, as even the geological range of the best known forms has not been as yet fully determined. ' Am. Jonr. Soi., vol. 7, 1824, pp. 31-43. 2 Philadelphia Acaa. Nat. Sci., Jonr., vol. 4, 1824, pp. 124-155. a Ibid., vol. 6, 1830, pp. 205-217. «GeoL Soo. America, Bull., vol.2, 1891, pp. 440-442, 450. ci'AKK 1 MARYLAND. 45 Among the more common species found in the Maryland Eooenev are — Ostrea compreasirostra Say. Dosiniopais Meekii Conrad. Cuciillsea gigantea Conrad. Cytherea oVata Rogers. i:ransversa Rogers. Pholadomya marylandica Conrad. Pectunoulus stamineus Conrad. Glycimeris elongata Conrad. Crassatella aljeformia Conrad. Pholas petrosa Conrad. palmula Conrad. Monodonta glandnla Conrad. caprieraninm Rogers. Turritolla linmerosa Conrad. Cardita regia Conrad. Mortoni Conrad. planicosta Lamarck. Among these CuculUea giganteais chie^j coiiQ.ned to the basal strata, although in individual cases, as reported by Uhler and Darton, it has been found in the upper portions of tlie series. Turritella Mortoni, on the other hand, is infrequent in the lowest beds, and in the sections ou the Potomac and its tributaries is found above those layers in which the GuGullma gigantea is most numerous. Hitherto few Eocene fossils have been obtained from the deposits of the eastern shore of the Chesapeake. At the head of the creeks tribu- tary to the Chester Eiver and on the hills to the north of the latter several characteristic forms are reported by Uhler.^ Among them Tur- ritella Mortoni, Cardita planicosta, Cucullwa transversa, Pectunmilus stamineus, and Ostrea compressirostra have been identified. On the western shore of the Chesapeake there are numerous locali- ties where typical Eocene fossils are found in great numbers. At South River, in Anne Arundel County, and Upper Marlboro, Fort Washing- ton, and Piscataway Creek, in Prince George County, the sections with their fossils have been studied with some care. The section^ afibrded by the Fort Washington bluff, so frequently referred to in geological literature, is presented below. Section at Fort Wasliington. Pleistocene .. Coarse gravel 8 feet. Eocene Red sand with casts of Turritella Mortoni, Doainiopsis Meekii, Cytherea ovata, Crassatella sp., Ostrea sp 12 feet. C Light, variegated sands, slightly glauoonitic 10 feet. ) Cretaceous.-.,^ Dark, micaceous sand, with Cyiirimeriadensata, Crassatella > 20 feet. ( vaclosa, Cuciillwa vulgaris, etc 10 feet. S Potomac ......Variegated clay, slightly lignitio on upper surface, with lay- ers of Ironstone 55 feet. The Eocene deppsits of Maryland must be considered to represent a single horizon until a more detailed examination of the range of the different fossil forms afford us evidence for a division upon that basis. > Marylanil Acad. Soi. Trans., vol. 1, 1888, p. 29. ' Johns Hopkins University Circulars, vgl. 9, 1890, p. 70. 46 THE EOCENE. (boll. 83. There is no State upon the Atlantic seaboard in which the Eocene has received such careful examiuation as in Virginia, and certainly none where the literature exists in such a compact and accessible form. For this geology is in the main indebted to Prof. William B, Eogers, who from 1835 to 1841 held the position of State geologist of Virginia and WHO published during that time annual reports, in each of which defined areas were taken up for detailed investigation. The first mention by Prof. Eogers of the occurrence of Eocene depos- its in Virginia was made in the Transactions of the American Philo- sophical Society for 1835' where, to use the author's words, "the exist- ence of an extensive Eocene formation in eastern Virginia is now for the first time announced." In n)y study of the Eocene of Virginia I have had occasion to refer constantly to Prof. Eogers's writings, aud from personal examination of the localities described have been impressed with the accuracy of that investigator's observations. More recently Mr. N. H. Darton,* of the U. S. Geological Survey, has examined the Tertiary area of Virginia, and has more accurately de- limited the extent of the Eocene in the various river basins. The deposits of the early Tertiary of Virginia form an intimate con- tinuation southward of the Maryland belt, and extend from the Potomac Eiver, where the width of outcrop is about 25 miles, to the James and its southern tributary the Appomattox, where the limits have been much narrowed. Throughout much of this region the thick cover- ing of post-Eocene sediments renders an exact delimitation of the boun- daries of the Eocene formation altogether impossible. Presumably this belt continues on to the southern border of the State, but so far as we have any evidence it is buried, throughout most if not all of that dis- tance, by more recent deposits. McGee^ reports a single occurrence on the Nottoway Eiver below Boilings Bridge where the Potomac form- ation "is unconformably overlain by 3 or 4 feet of stratified greenish- blue clay containing Eocene fossils." The strike of the strata is approximately north and south ; the dip at a very low angle toward the east. If we take the data furnished by the well-boring at Fortress Monroe, not 50 miles to the east of the supposed seaward boundary of the Eocene, we find the sands that have been referred to that formation a^ a depth of something less" than 600 feet. This at the outside would admit of a dip of 10 to 15 feet to the mile.. On account of the surface covering of post-Tertiary deposits, the sections are chiefly found 'along the water courses or on the steeper ' Am. Phil. Soc, Trans., new sfx., vol. 5, 1835, pp. 319-341. 2 Geol. Soc. America, Bull., toI 2, 1891, pp. 439-413. •Am. Jour. Soi., 3d scr., vol. 35, 1688, p. 120. CLABK.] VIRGINIA. 47 slopes of the higher ridges. The slight elevation of the coastal plain above tide level, together with the incoherent nature of the materials, renders the occurrence of high cliffs even along the larger rivers ex- ceptional and consequently the superposition of any considerable thick- ness of strata in a single section out of the question. It thus becomes a matter of some difficulty to measure accurately the entire thickness of the Eocene deposits, but it is doubtful if they are found to exceed 150 feet. In fact no single section thus far described shows a thickness of even 100 feet. The deposits are in the main identical with those hitherto described as typical for Maryland. The green-sand marl predominates, though beds of a micaceous or aluminous character are not infrequent in the southern portion of the area. Along the northern portion of the belt, the Eocene marl rests un- conformably upon the Fredericksburg sandstone, the local represent- ative of the Potomac formation. Farther south, however, the Eocene overlaps the Archean and so continues until it is itself buried by more recent deposits. To the east it is followed in direct succession by the Neocene, while over the whole, when not completely eroded, an uneven covering of post-Tertiary deposits is found. The most northern and one of the most typical of the river sections of the Virginia Eocene is found upon the south bank of the Potomac Eiver, extending from the mouth of Acquia Creek to the vicinity of Mathias Point. At Acquia Creek the following section of the Eocene overlain by Pleistocene has been observed by the writer.^ Section at Acquia Creek. Pleistocene Red saDdy loam '. 20 feet. f Light-colored sand, slightly glauconitic 20 feet.^l Light green-sand, with Cardita jylanicosta, Turritella Mortoni, CucalleBa onocheJa. Crasatella capriora- nium, Cylherea ovata, etc 9 feet. Soft, yellowish green-sand, with Ostrea compressi- Eocene ■; rostra 15 feet. } 65 feet. Ledge of dark green-sand, with Turntella Mortoni, I Cardita planicosta, Panopiea elongata, Fusus ap. I etc 3 feet. I Dark greeu-sand, with Cytherea ovata, Crassatella (, capricranium, etc 18 feet. ^ In the basin of the Eappahannock the Eocene is reported by Darton as extending from the vicinity of Fredericksburg to a point below Port Eoyal. He says that it consists at the higher elevations landward of buftcolored weathered green-sand that to the east becomes a typical green-sand with abundant and characteristic fossils. Eogers and Dar- ton both refer to the exposures of Eocene in the valleys of the Matapouy and Pamunky that afford a marked admixture of argillaceous materials ' JohD Hopkins University Oirculara, vol. 9, 1890, p. 70. 48 THE EOCENE. [BULL. 83. and at times show bands of limestone. The Eocene is not reported from the basin of the Ohickahominy. On the James Eiver, however, the bluffs, particularly in the vicinity of City Point, afford excellent exposures of Eocene green -sand with numerous characteristic fossils. In its paleontological characteristics the Eocene of Virginia is closely allied to that of Maryland. The common forms Turritella Mortoni and Gardita planicosta are widely distributed, while the prevalent oyster of Maryland, the Ostrea compressirostra, has given place for the most part to Ostrea sellceformis, so important as a typical Eocene fossil in the States farther south. Among the species recognized from the Virginia strata are the fol- lowing : Ostrea sellaeformis Conrad. sinuosa Rogers. Anomia Ruffini Conrad. Cuculliea transversa Rogers. onochela Eogi rs. Nuoula cnltelliformis Rogers. parya Rogers. Naonlana improoera Conrad. Cardita planioosta Lamarck. ascia Rogers. Crassatella capricraniura Rogers. Protocardia virginiana Conrad. Cytherea ovata Rogers. lenticularis Rogers. eversa Conrad. lenis Conrad. liciata Conrad. perbrevis Conrad. Dosiniopsis alta Cnnrad. Turritella Mortoni Conrad. Even less is known of the range of these forms in Virginia than in Maryland, and they afford no basis' for a division of the strata into separate horizons. The Eocene of Virginia must be considered, for the present at least, as a single lithological and paleontological unit. NORTH CAROLINA. The Eocene of North Carolina is. very different from that in Mary- land and Virginia. Neither in the stratigraphical nor paleontologi- cal characteristics of its members does it afford many points for com- parison with the Eocene of the more northern areas. Furthermore, the isolated manner of its occurrence makes a determination of its boundaries extremely difficult, and thus, hitherto, where fossils have not been found its separation from other horizons has been rendered uncertain. Prom the State reports of Emmons and Kerr and the pale- ontological writings of Conrad our knowledge of the structure and fossils of the Eocene is mainly derived. Geographically considered, the Eocene is confined in its northern and southern extension between the Neuse and Cape Fear -Ei vers, and is found scattered between those limits from near the mouths of the larger streams to over a hundred miles inland. As in Virginia the sections are chiefly exhibited along the river channels, which alone cut through the surface covering of more recent deposits. Thus the cliffs along the banks of the Neuse, New, and Cape Fear Elvers and their larger tribu- taries afford the best exposures. The Neuse, between New Berne and CLARK.] NOETH CAKOLINA. 49 Goldsboro and its large southern tributary, the Trent, for the last 30 or 40 miles of their courses, frequently cut. through Eocene strata. The headwaters of the New, in Onslow County, aud its southwest branch penetrate similar deposits. The lower course of the Cape Pear in Bla- den aud New Hauover Counties and the Northeast Cape Fear, in the latter county, afford extensive sections. Some distance to the west of the Coastal region several isolated areas of the Eocene occur, that in each case reach an altitude of over 300 feet above sea level. The most northern of these areas is situated a short distance east of Kaleigh, while two others occur to the northwest of Fayetteville in Harnett and Moore Counties. If, as seems probable, these isolated outcrops are but the remnants of a once continuous belt of Eocene strata, then the in- land extension of the Eocene must have been more than 100 miles from the present coast line. The relations of the Eocene to the Cretaceous on the one hand aud " the Neocene on the other are especially well exhibited in the basin of the Cape Fear Eiver, where the Eocene has been shown by the writer^ to occupy hollows within the "Cretaceous, which afforded an unevenly eroded surface upon which the sediments of the Eocene period were accumulated. The erosion that followed the elevation of the Eocene deposits approximately base-leveled the region before the submergence in Neocene time. Kerr became convinced latterly of a much wider extension of the Eocene than had been previously admitted by hira or other writers upon the geology of the State. In an article in the American Naturalist for 1885 upon " The Eocene of North Carolina," ^ he states : I have recently ascertained by the discovery of the unmistakable superposition of the small outliers of Eocene fossiliferous rocks (noted iu the text aud geological map of the State in the report of 1875) and of other similarly situated patches of the same beds, with Upper Eocene shells capping the highest hills of the so-called Drift or Quaternary, that nearly all of these beds of sand and gravels heretofore referred to the latter horizons are of Eocene age. The area of Tertiaries in this State must now be extended over a wide stretch of country from the tops of the Laurentian hills near, Raleigh and the higher elevations of the Huronian slates to from 50 to 75 miles south- east along the course of the Deep Eiver and so onward to the South Carolina border, reaching at one point an elevation of 600 feet above tide. This leaves the Quater- nary, like the Miocene, to be represented by a thin and broken covering of superficial deposits of only a few feet to a few yards in thickness and reaching from the coast only about 100 miles inland, aud an elevation of but little above 100 feet. Although from the data at hand it seems probable that the views of "Professor Kerr, as to the wide distribution of the Eocene, are too extreme, yet the supposition that the post-Eocene depressions were not sufficient to bring the higher and more inland portions of the Eocene deposits below sea level, is fully substantiated by the facts. Our knowledge of the stratigraphy is far too meager to admit of the incorpo- ration in the Eocene of many of the unfossiliferous beds that such a ' Geol. Soo. America, Bull., vol. 1, 1890, p. 6S8. = Am. Naturalist, vol. 19, 1885, p. 69. Bull. 83 4 50 THE EOCENE. [bulu83. conclusion would require. Much that Kerr has included in the Eocene is referred by McGee and Holmes to the Appomattox formation. In the character of its deposits the Eocene is in a marked degree cal- careous, occurring as a finely comminuted, light-colored marl, shell con- glomerate, calcareous sandstone or hard, gray limestone. The isolated outcrops situated far inland are more siliceous than the deposits in the extreme eastern portions of the State, which afford still further evidence of their closer proximity to the shore of the Eocene sea. The calcare- ous nature of the eastern deposits indicates a comparatively clear and open sea and a sufBcient distance from the Eocene shore to prohibit the intermingling of large quantities of land-derived sediments with the calcareous accumulations of marine organisms out of which the strata are largely formed. The paleontological characteristics of the North Carolina Eocene are very imperfectly comprehended. No collections of importance are now in existence^ and the lists of fossils hitherto reported can not at the present time be substantiated. Moreover, there is particular danger in the use of such data so far as the North Carolina deposits are con- cerned from the fact that a commingling of Cretaceous and Eocene fos- sils is known to occur. Futhermore, that intermixture has been shown to be due to mechanical agencies rather than contemporaneous exist- ence. The best evidence of this may be seen in the limestone beds iu the vicinity of Wilmington, where this remarkable occurrence has been observed and recorded by several investigators.' A few typical Eocene fossils have been recognized by myself from the North Carolina Eocene deposits, including Ontrea selloeformis and Cardita planicosta. From the fact that the fossils are chiefly preserved in the form of casts, their determination is frequently in doubt, and ex- tensive collections will have to be made before a comparative study of the forms will afford satisfactory results. SOUTH CAROLINA. In many of its structural peculiarities the Eocene of South Carolina shows a close relationship to the early Tertiary deposits of North Caro- lina that have just been described. In its geographical distribution it covers a much more extensive area than in the States hitherto referred to, and becomes one of the most important features in the geology of the Coastal plain. The reports of Ruffin, Tuomey, and Lieber present us with detailed descriptions of the stratigraphy of the Eocene, while Eavenel, Conrad, Bonv6, and others have figured and described the organic remains from the same horizon. Although a review of the conclusions arrived at by these different authors affords but few points for comparisons with ' Tnomey, Am. Assoc. Adv. Soi.,Proc., vol. 1,1848, p. 33; Tnomey, Philadelpliia Acad. Nat. SoLiProc, vol. 6, 1852, 193; Conrad, Philadelphia Acad. Kat. Sci., Proc, vol. 17, 1805, p. 72; Clark, Geol. Soc. America, Bull., vol. 1, 1890, pp. 537-540. CLAEK.] SOUTH CAROLINA. 51 other areas, careful descriptions of local deposits render the literature of South Carolina geology among the best of official publications. Numerous sections within the Tertiary belt ai'e discussed in minute de- tail, but the attempt at a geological establishment of boundaries has given vague and unsatisfactory results. The inland border of the Eocene forms a more or less continuous line "from the mouth of Stevens Creek, on the Savannah, north of Hamburg, crossing the Saluda and Broad Elvers near their junction ; the Wateree at the canal ; Lynch Creek at Evans Ferry, and Thomp- son Creek at the point whBre it enters the State in Chesterfield dis- trict."^ Its seaward extension isj)uried under more recent deposits, of different character, or the disturbed upper layers of the Eocene itself, a condition of outcrop that occasions an extremely sinuous boundary, and one at the same time very difBcultof determination. In the vicin- ity of Charleston the strata approach nearly to the coast line, though complicated in the aforesaid manner. As the river sections afford almost the only indications of the pre Quaternary geology the field of observation is much narrowed, and the tracing out of intermediate deposits, binding what may be only different fades of contemporane- ous development, is greatly hindered. Tuomey, in the " Eeport on the Geology of South CaroHua," pub- lished in 1848, divides the Eocene of the State into three horizons, which in ascending order are : 1, Buhrstone ; 2, San tee Beds ; 3, Ashley and Cooper Beds. Euffin had previously (1843) designated the last two of Tuomey's^ divisions as the "Great Carolinian Bed," and had like- wise described the Buhrstone and its fossils, although he did not con- sider the latter apparently of much taxonomic importance, and, more- over, entirely mistook its stratigraphical position. Following in great measure the authority of Lyell, EufBn accepted tentatively the Eocene age of the " Great Carolinian Bed," thus going counter to the opinions of Vanuxem, Conrad, and Morton, who had pronounced it " Upper Secondary." In a later statement he says, "the ' Great Carolinian Bed' of marl will serve every present purpose of designation and distinction as if it were definitely settled and the bed named either ' Upper Creta- ceous' or Eocene."^ The important contributions made by EufiSn to the geology of the State were greatly augmented by the more exten- sive observations of Tuomey. For our present purpose the three divis- ions established by the latter will be accepted, although some sugges- tions as to their taxonomic value will be stated in subsequent pages. TheBulirstone. — The Buhrstone, the basal member ofthe Eocene series, as recognized by Tuomey, occupies the inner border of the Tertiary belt. ' Tuomey : Eeport on the Geology of South Carolina, 1848, p. 140. 2 The Santee Beds Geolopfy and Mineralogy of Seorgia, 1871, p. 28. * Catalogue of Ores, Rocka, etc., for the Paris Exposition, 1878, p. 14. « Am. Jour. Sci.. 2d ser., vol. 41, 1866, p. 96. ctAKK.] GEORGIA. 55 borizon. The deposits are similar to tlmse represented on the Carolina bank of tUc Savunuali Eiver, and previonslj- referred to. The position of the strata in the Eoceae series can not be determined until more is known of the fossils and the stratigraphical relations of the beds. A section made by myself at the locality is given below : Feet Eecl loam 40 White sandy marl 4 Coarse white marl with shell fragments 2 Fine white marl with Ostrea sp 2 Shell marl with numerous casts 4 Coarse yellowish white shell marl.. 5 Compact fine white marl 2 White sandy marl with Ostrea georgiana 10 Ledge of hard white marl 1 Fine yellowish -white, sandy marl 8 Cohapaot marl filled wi th casts of shells, Ostrea sp 5 Yellow shell marl alternating with beds of clay 6 Indurated yellow and white variegated shell marl 6 Yellowish white, coarse shell marl wil h numerous fragments of shells 14 The detailed sections of other observers' differ considerably from that just given, both as to the divisions of the beds and th,e fossil-bearing horizons. The deposits at Jacksonboro in Screven Oouuty, hitherto referred to the Eocene, although presenting siioilar characteristics lithologically, afford, so far as the collections made by myself are concerned, no forms in common with other Eocene localities, Lyell gives a long list of such similar types, but I have failed to obtain, them. The specimens collected seem to point to a decidedly younger fauna, probably Neocene in age. Dr. Jones, in a report on the agricultural resources of the State, refers to the shell marl of Washington and Jefferson Counties, although pre- senting few data of stratigraphical importance. Of the more western counties even less information is at hand. The section of Eocene strata aftbrded by the Chattahoochee Eiver has been quite recently investigated by Langdon,^ who, however, has studied the deposits in their relations to the Alabama series and mainly on the Alabama bank of the river, so that a detailed considera- tion of them will be deferred until the strata of that State are discussed. Eepresentatives of the Lignitic, Buhrstone, Claiborne, and White lime- stone have been established and the thickness of the series placed at 1,200 feet. FLORIDA. The presence of Eocene strata in Florida was early recognized by Conrad^ and Tuomey^, though later doubt was cast upon their couclu- ' Loughbridge — Eeport on the Cotton Production of the State of Georgia, Tentli Census of tlie U. S. vol. 5, 1884, pp. 14-16. Singleton— see Heilprin, Contrib. Tert. Geol. and Pal. U. S., 1881, p. 32, foot-noto. 2 Geol. Soo. America, Bull., vol. 2, 1891, pp. 594-605. 'Am. Jonr. Sci., 2d sor., vol. 2, 1846, pp. 36-48, pp. 399, 400. «Ibid., vol. 11, 1851, pp. 390-394. 56 THE EOCENE. [bull. 83. sions by Agassiz' aud Le Conte,^ who endeavored to prove that tlie lieninsula was of coral formation and more recent in origin. The later investigations of Smith, Dall, Heilpriu, and Johnson have shown the truth of the earlier observations, and have more fully identified the various horizons represented. That Eocene covers a wide area iu Florida is now generally conceded, though the various writers differ as to the limits that are to be assigned to it. Direct reference to the publications will best explain these dif- ferences. Smith says: From specimens collected by me at points -widely distant from each other, from tbe observations of others as qnoted above, and from evidence derived from other sources, I am brought to the conoln.sion that almost the whole of Florida, from the Perdido Eiver on the west, eastward and southward, including the middle and west- ern parts of the peninsula, certainly as far south as the latitude of Tampa Bay, and probably as far as the latitude of Charlotte TIarbor, has for its underlying formation the white of .Orbitoides limestone of Vicksburg age, the exceptions as yet known being the post-Pliocene or recent limestones forming the Keys and the immediate coasts along the western, southern, and eastern shores, and isolated patches, if not a continuous belt, of Miocene limestone between the St. Johns Eiver and the elevated tablelands westward. Heilprin,^ in his " Contributions to the Tertiary Geology and Paleon- tology of the United States," remarks upon the geographical bounda- ries : From what has preceded, taken in connection with the observations that have been made in western as well as in northern Florida, it may safely he conceded that the underlying rook of the greater portion, if not of nearly the entire State, is of Oligocene age, and therefore no countenance is given to the theory which assumes a recent formation. How far south the Orbitoitic limestone extends has not yet been determined, but there appear to be no reasons for assigning it to a limit far removed from the border line of the Everglades. For aught we know to the contrary, it may extend quite or nearly to the peninsula's extremity. Dall,* discussing the same point, says : The older rooks of course come out to the northward and along the central part of the peninsula, and the succession of the newer ones is toward the southern extreme end, and the Atlantic and Gulf shores. The hypothetical southward extension of the Oligocene (sometimes taken as Eocene) on most recent geological maps, now seems erroneous. It is without doubt represented as considerably too great. Johnson* states in regard to its limits that — The most southern actually seen are at Pemberton, Pasco County, and on the head- waters of Hillsboro River, in Polk County, Sees. 27 and 28, T. 26, R. 23— which, till farther advised, may be set as the southern boundary of Eocene exposure. From the above statement of views it will be perceived that the Eocene covers a wide area in the State, even though somewhat restricted iu ' Report tr. S. Coast Survey, 1851, op. U5 et seq. 2 Am. Jour. Sol., 2d ser., vol. 23, 1857, pp. 48-60. •Pages 23, 24. •Am. Jour. Sci., 3d ser., vol. 34, 1887, p. 165, •Ibid., vol. 36, 1888, p. 233. cLAitK.] FLORIDA. 67 range, as suggested by Dall and Johnson. The deposits are in the main calcareous, and possess many points in common with the "calca- reous strata of the Charleston basin," though paleontologically more closely allied to the limestone of Alabama and Mississippi, described later on. The Eocene strata in the northern portions of the State apparently afford two horizons, the significance of which has not been as yet fullj^ determined. The lower horizon, composed chiefly of limestones and marls, and the one most generally represented, contains great numbers of Orbitoides Mantelli and Pecten perplanus. Overlying this is a thin layer, generally silicified, that contains Orbitoides epMppium, 0. dispansa, and OpercuUna complanata. Johnson states that "it is a mistake, however, to suppose that this Nnmmulitic formation everywhere hides the Vicksburg rocks of the Orbitoides Mantelli, or ever did overlie the whole of it. Numerous are the exposures to prove the contrary." A typical locality in which to see the superposition of the beds is at Lovyville, Levy County, where the upper horizon is "really a stratum overlying the Vicks- burg rocks," and "is a beautiful, soft, porous building stone about 20 feet in thickness." "Often struck in artesian borings and easily identified by the jieculiar nummulites, it has a greater thickness under the Neocene formations to the east. In these western regions it has probably suffered general removal by erosion. Apparently conforma- ble in deposition with the Vicksburg stage, the Levyville formation is evidently not identical with it, and demands a further investigation." Later observations tend to show that Johnson has confounded the Eo- cene and Miocene siliceous rocks at many points, so that his conclusions are somewhat vitiated. No other portion of the coastal area has received such careful and de- tailed investigation as that contiguous to the Tomb^gbee and Alabama Elvers. The publications of Hale, Conrad, Tuomey, Lyell, Hilgard, Winchell, Smith, Johnson, ^langdon, Heilprin, Aldrich,and others afford an extensive literature that gives ns the results of investigations extend- ing over a long term of years. The State geological survey, under the directorship of Prof. E. A. Smith, has been the chief factor in this work, and its members have compiled the only complete section of the early Tertiary strata that has thus far been made. The deposits of Eocene age extend across the State from the Chatta- hoochee Eiver to the Mississippi border in a slightly sinuous southeast and northwest direction, and with an average width of about 60 miles. The thickness of the entjre series has been estimated by Smith to be not far from 1,700 feet and the dip seaward approximately 30 feet to the mile, although marked variations occur at several points. The 58 THE EOCENE. |bui.l.83. divisions established by Smith and Johnson ' are adopted here, and are in descending scale as follows : reet. C Coral limestone CVictsburg ?) 15Q ' White limestone . ■< Vicksburg (orbitoidal) 140 ( Jackson 60 Claiborne 140-145 Buhrstone 300 f Hatchetigbee 175 Eocene. <; Woods Bluff 80-85 Bells Landing 140 Lignitio •; Nanafalia 200 Matthews Landing and Naheola. 130-150 Black Bluff 100 LMidway 25 lAgnitic, — The lowest member of the Eocene series has been desig- nated the Lignitio by Hilgard. It has a thickness of about 900 feet,- and according to Smith and Johnson — Is made up of laminated clays and laminated and cross-bedded sands of a prevailing gray color, except immediately below the Buhrstone, where for 200 feet or more they are of dark brown, often purplish colors. With the above-mentioned laminated clays and sand are interstratified several beds of lignite and several beds holding marine fossils, and usually characterized by the presence of glauconite or greensand. * * » The Lignitic formation comprises three well marked divisions defined by color, which is here an index of Constitution. The upper one-fourth consists of irregularly bedded, dark, siliceous, and lignitiferojis clays and heterogeneous sands, approaching the basal portion of the Buhrstone formation in composition and structure, interstratified with discontinuous beds of lignite and continuous layers of clay and sand containing marine fossils. The medial three-fifths of the formation is made up of rather more regularly stratified clays and sands of light color, frequently cross bedded, contain- ing occasional beds of lignite and of marine sands yielding littoral fossils, one of which (the Grryphoea thirsce bed) is 50 to 60 feet in thickness. The basal deposits are irregularly bedded, dark, or even black, calcareous, shaly or slaty clays, with few fossils or definite beds of lignite, though considerable quantities of carbonaceous mat- ter are disseminated throughout its mass. At the base of the Lignitio there is a rapid change in the character of both rocks and fossils, the lowermost 15 to 20 feet of the formation being limestone, at first argil- laceous, then quite pure, and even crystalline. This crystalline limestone rests with apparent conformity upon the yellow sands which make the summit of the Creta- ceous group.' The Lignitic group as a distinct horizon ia, according to Smith, sep- arated from the overlying formation (Buhrstone) upon lithological grounds alone. He says : In the strata which we have called Lignitic the material, as compared with that of the Buhrstone, is more sandy and calcareous and at the same time more fossil- iferous. The shells in many cases are decayed and the calcareous matter of the same often appears to have been leached out and diffused through the surrounding sands, occasionally cementing them together and forming calcareous sandstone. These sandstone beds always show a tendency to weather into rounded, bowlder-like masses, which project from the faces of the bluft's or, broken off, roll down, forming a talus. When broken open these bowlders usually show a nucleus of thoroughly decayed shells or of ferruginous, lignitic matter. * * * A ledge of calcareous sandstone of this kind is found about 20 or 30 feet below the lowermost of the alu- > U. S. Geol. Sury., Bull. 43, 1887, p. 18. '^Ibid., pp. 39, 135. CLAUK.] ALABAMA. 59 minous rocks, which we consider as characteristic of the Buhrstone, and similar cal- careous sandstones weathering into bowlders occur at intervals throughout the un- derlying Lignitic strata. » * • None of the beds of the underlj'iug Lignitic have even a remote resemblance to the Buhrstone rocks, except certain indurated clays which overlie the Grypkcea tliirsm beds in the Grampian Hills of Wilcox County and their prolongation into Butler County. Even in this case the distinction between the two can readily be discovered, as the indurated clays of the Lignitic are, in some of the beds, quite full of shell casts, principally Turritellas and Cythereas, and the materii^ itself, upon close examination, does not so strongly resemble the Buhrstone as upon first sight appears.' Tho Lignitic occupies the inland border of the Eocene area, increas- ing in thickness from the east toward the west. The interstratifiefl marine beds, each of which has its " peculiar association ot fossils," together with certain "lithologic and structural character," have been divided by Smith and Johnson into the following 7 horizons, which are given in descending order : 7. The Hatchetigbee marls. 6. The "Woods Bluff or Bashi marl. 5. The Bells Landing series. 4. The Nanafalia or Gi-yphcea thirsw marl. 3. The Matthews Landing and Naheola marls. 2. The Black Bluff beds. 1. The Midway or Pine Barren beds. The sections exhibited on the Alabama and Tonibigbee Elvers are characterized as follows : ^ ^ The Midway or Pine Barren seotion. — Thickness, 2.5 feet. The strata are: a white, argillaceous limestone holding a large nautilus, which is characteristic of the hori- zon, 10 feet ; calcareous sands and a yellowish crystalline limestone, with Turritel- las, Carditas, and corals, the sands 6 feet, the limestone 8 or 9 feet. This section is best seen in eastern Wilcox County, on Pine Barren Creek, but the upper or Nautilus rock occurs at Midway, on the Alabama River, and westward across Marengo County. The BJacJc Bluff section. — We have difficulty in determining the exact thickness, since on the Tombigbee the strata of this section are spread over an extent of sur- face which would, with uniform dip, correspond to a thickness of over 200 feet, while on the Alabama, and more particularly inland in the eastern part of Wilcox County, the thickness is not greater than ?5 or 40 feet. Since 80 feet of these beds are seen in snijerposition at one locality (Black Bluff), we think that the maximum thickness can not be less than 100 feet. The characteristic strata which compose nearly the whole of this section are black or very dark brown clays, which are in part fossil- iferous. The Naheola and Matthews Landing stction. — It is difficult to give the precise thick- ness of this section, since it varies on the two rivers. We have placed it at 130 to 150; the strata are gray, sandy clays in the main, alternating with cross-bedded sand. The beds of dark, sandy, and glauconitic clay, containing marine fossils, lie at the base of the section. At Naheola, on the Tombigbee, the upper and more glauconi- tic part of the bed is most prominent, while at Matthews Landing, on the Alabama, the lower part of the bed dark gray sandy clay forms the bluff. The Nanafalia or Coal Bluff section. — The strata of this section are 200 feet in thick- ness, and consist of about 50 feet of gray sandy clays at top, which shows a tendency to indurate into tolerably firm rocks resembling very closely some of the strata of the 'U. S. Geol. Sarv., Bull. 43, 1887, pp. 35, 36. ^bid., pp. 69, 70. 60 THE EOCENE. " . Ibuli. 83. Bnhrstone. Belnw this, about 80 feet of sandy beds, often strongly glaiiconitic, cliar- acterized thronglioiit by sliellsof a small oyster {Gryphwa ihirsat). Near tbe base of this sandy division there is a bed_ about 20 feet thick, literally packed with these shells. Below the Gryphwa iliirsm beds follow some 70 feet of cross-bedded sands, glauoonitic and apparently devoid of fossils, including, about 10 feet from the base of the section, a bed of lignite which varies in thickness from 4 to 7 feet^ The Bells Landing section. — This is 140 feet in thickness, and includes two impor- tant marine beds, and a third quite small and apparently unimportant. These fos- siliferous beds are interstratified with yellowish sands in the upper and rather heavy bedded sandy clays in the lower part of the section. The upper marine bed, called the Bell's Landing marl, is about 10 feet in thickness and has 40 feet of sandy strata above it. The middle bed is called the Greggs Landing marl, and it is 20 to 25 feet below the preceding; it is about 5 feet in thickness. The lowermost of the fossilif- erous beds of this section is only about one foot in thickness and lies about 50 feet below the Greggs Landing bed. It is higLly glauconitic, but does not contain any great variety of fossils. The Bells Landing marl is distinguished from all others in Alabama by the great size of the shells which it contains. Valuta NewGombiana, Bostellaria trinodifera, Turritella Mortoni, Gar- dita planicosta, and Ostrea compressirostra are common forms. The Wood's Bluff or Bashi aeciion. — This is 80 to 85 feet in thickness. The upper- most 30 feet of the section consist of dark brown clays passing into a green sand, which holds a great variety of finely preserved marine shells. Below this greensand marl are gray sandy clays, with 4 or 5 thin beds of lignite within the first 25 feet, succeeded by about 30 feet of cross-bedded sands, with a 2-foot seam of lignite at the base. The Batchetigl)ee section. — This section is 175 feet in thickness, made up of sandy, clays of prevailing brown or purplish color, containing 3 or 4 beds of marine fossils in the uppermost 75 feet, and of somewiiat similar pui'plish brown sandy clays nearly devoid of marine fossils in the lower 100 feet. All these brown sandy clays become much lighter colored upon drying and exposure to the weather. Due to several folds in the strata, the Lignitic beds appear at the sur- face at several points to the south of its continuous outcrop, and have been very fully investigated in the western portion of Clarke County. Langdon' has recently published an article in which the continuation of the Lignitic into the Chattahoochee drainage is shown. Several of the horizons established by Smith in the central and western portions of the State are traced to the banks of the Chattahoochee Eiver, al- though they frequently exhibit marked changes in both deposits and fos- sils. In general the strata present a more marine phase, and the lig- nitic character of the beds farther west is gradually lost. The Midway or Pine Barren beds reach the thickness of about 220 feet on the Chatta- hoochee and become the most important member of the Lignitic series. The Black Bluff beds and the Matthews Landing and Naheola marls are wanting. The Nanafalia marl rests unconformably upon the Mid- way beds and attains a thickness of 175 feet. This marl was considered Claiborne by Loughridge.^ The Bell's Landing series is 173 feet thick on the Chattahoochee, and is with difiBculty separated from the overly- ' Geol. Soo. America, Bull., vol. 2, 1891, pp. 587-605. ■ Eep. on the Cotton Prodaotion of Ga., 10th Census, vol. 15, p. 14. ':eological stTFc/Ey BUT.I£II17 83 . PL : ci-ARK.] ALABAMA. 61 ing formation, the Wood's Blaff or Bashi marl, whicli here attains a thickness of 44 feet. The uppermost member of the Liguitic, the Hatohetigbee marls, present quite similar lithologioal characteristics on the Chattahoochee River as at the place of its typical development, though the beds have been reduced to 10 feet in thickness. Buhrstone. — Overlying the Lignitic is a series of alluminous sands and sandstones that are at times glauconitic, even appearing locally as well- defined layers of greensaud. In most oases tbey are merely alterations of indurated clays, with alluminous sand- stones of varying degrees of hardness. While in the extremes of pure clay and almost pure' quartz the materials of this formation differ widely, the formation as a whole leaves upon the mind of the observer a lively impression of the uniformity in the lith- ologioal structure and general appearance of its constituent strata. * * * In general the uppermost beds (15 to 20 feet) are composed of joint clays, which, when indurated, form tolerably firm rocks. Near the base of the formation similar clays or claystones are usually seen. In many places there is a bed several feet in thickness of a hard, siliceous, or flinty sandstone, almost a quartzite, just at the base of the Buhrstone.^ Smith and Johnson separate this horizon from the Lignitic upon lith. ological grounds alone. Following Tuomey, they employ the term Buhrstone to designate it. They say, " The aluminous rocks we assign to the Buhrstone, while the sandy rocks, with the intercalated beds of calcareous matter we place with the Lignitic." Although this discrimi- nation seems possible in Alabama, too little is known of the relationship of the beds beyond the State to say whether this difference is wide- spread. The Buhrstone is found as a sinuous band to the south of the Lig- nitic, and extending from southeast to northwest across the State. On the Alabama Eiver the uppermost of the Buhrstone beds are well exposed at Lisbon Landing, and the lowermost a short distance above Hamilton's, whence they extend across Clarke County westward or northwestward to White Bluff and McCar- thy's Ferry, and thence in a northwesterly direction across Choctaw County, just south of Butler. On the eastern side of the Alabama Eiver they appear in the hills south of Bells Landing, and across Monroe County north of Kempsville and south of Turn- hull, turning a little to the northward in the eastern part of the county. To the east- ward they may be seen again near Ozark, in Dale County, and near Abbeville, in Henry County. ^ There is considerable doubt as to the thickness of the Buhrstone series, but the least estimate places it at 300 feet. The fossils do not afford a means of discrimination either from the Claiborne above or the Lignitic below. They are not numerous and are for the most part poorly preserved. Langdon^has more recently noted the occurrence of the Buhrstone on the Chattahoochee, where " the perceutage of clay decreases, while the rocks become more calcareous and the fossils more abundant. In lieu of the silicifled casts characterizing the Buhrstone of the Tombig- ' XJ. S. Geol. Surv., Bull, 43, 1887, pi>. 35, 36. 2 Ibid., p. 30. • Geol. Soc. America, Bull., vol. 2, 1891, p. 537. 62 THE EOCENE. [bull. 83. bee and Alabama Rivers, extensive beds of Ostrea sellwformis (var. divaricata) and au Anomia occur." The thickness of the beds here is stated to be about 190 feet. Claiborne. — The Claiborne formation, so typically represented at the Claiborne Bluffs, on the Alabama Eiver, consists of incoherent sands and clays, that are frequently ferruginous or calcareous and often glau- conitic. The thickness of the deposits is about 150 feet. The beds of this horizon are renowned for their many fossils, which, however, are chiefly confined to the ferruginous sands near the top of the formation. Beneath this upper bed, known as the " Claiborne Fossiliferous sand," and which is about 15 feet in thickness, are " some 60 feet of calcareous clays and calcareous sands." The whole of this 60 feet of strata, except perhaps some 10 feet of bine clay near the top, is distinguished from all the other beds of the Claiborne formation by the great numbers of shells of Ostrea seUceformis which it holds. These shells are found more abundantly in the hard sandy ledges which occur at intervals of a few feet through the whole thickness of these beds. * * » Below these Ostrea seUceformis beds we find at Claiborne and at Lisbon some 50 feet or more of sandy and clayey beds in many oases strongly glauconitic and holding a great number as well as a great variety of well preserved fossils.' A generalized section of the Claiborne Bluff, according to Prof. E. H. Smith, is given below : ^ 7. A bed of very variable thickness, consisting of sand, pebbles, and red loam, which forms the surface over a great part of the State. The average thickness of this bed aloug the blufif may be put at 35 to 40 ft. 6. A band of white limestone, containing glauconite grains, forming vertical faces usually striped by thin projecting ledges about 45 ft. 5. A band showing two very distinct parts, viz, au upper part, a bed holding great numbers of Scutella Lyelli, 3 feet thick, and a lower part, 6 feet thick, of coarse, ferruginous sands, which are indurated at the base and form a very marked pro- jecting ledge 9 ft. 4. A band of very uniform appearance of reddish yellow or buff color, consisting of a mass of shells embedded iu red sand. This is the celebrated Claiborne sand. It weathers very smoothly and is less projecting than the ledges above and be- low it 15 to 17 ft. 3. A band of light gray calcareous clay with a few sandy stripes and indurated ledges 25 to 28 ft. All these beds make up the nearly vertical part of the bluff near and between the two landings. Below these to the river level the slope is almost entirely covered by the loose fragments rolled down from above, so that the underlying stratified rooks are discovered only where these loose materials have been re- moved. Between the upper landing and the ferry these lower strata of the bluff are more clearly exposed to view. 2. A band of light yellowish, gray, calcareous sand striped with a number of hard ledges of similar sandy material. This band is a very prominent part of the bluff, but is in many places, as above stated, much obscured by the fragments of the other beds which have rolled down from above about 35 ft. ' tr. S. Geol. Surv., Bull. 43, 1887, pp. 20, 27. ' Ibid., p. 28. c"KK] ALABAMA. 63 I. A baud of dark bluish green color, consisting of clayey sands and clays passing downward into a green sand bed 6 to 8 feet thick, which appears, however, above water only above the upper lauding about 12 ft. No. 4j probably represents the top of the Claiborne division. The base of the series is not reached at this point, but the following more detailed section presents in Kos. 6-15 the portion of the Claiborne Bluflf just given in Nos. 1-4, while Nos. 1 [l]-6 [6] in the detailed section are represented at Lisbon Landing, a few miles above, thus affording a complete series of the Claiborne in the vicinity of its type locality. Smith says : There is no doubt as to the geologic horizon of the Lisbon section, since the two lowermost beds of the Claiborne section appear at the top of the Lisbon Bluff, the peculiar association of the shells making the identification easy and certain.' Detailed section of Claiborne group of Claiborne Bluff and Lisbon Landing, Alabama Biver, after Smith and Johnson.^ 15. Ferruginous sand, holding vast numbers of comminuted as well as well preserved shells. Near the center of this there are in places thin bauds of lignite, and along the ferry road the upper part of it is composed of laminated gray clays filled with leaf impressions. This is the source of the celebrated Claiborne fossils, and we shall call it the Claiborne Fossiliferous sand. In mauy parts of Monroe and Clarke Counties, where this bed is more protected, -the material in which the shells are embedded is seen to be a green sand, while at the Claiborne Bluff and vicinity, and at a bluff above St. Stephens, it is completely oxidized into a red ferruginous sand. Thickness about Claiborne 15 to 17 fb. 14. Bluish green glauconitio, sandy marl, with Ostrea aellmformis usually somewhat indurated above, and forming a hard projecting ledge 3 to 4 ft. 13. Calcareous clay or clayey marl, of gray color when dry, but blue when wet. It contains a few badly preserved chalky fossils, Bulla and small Turritellas. This bed becomes sandier below, as well as glauconitic and highly fossiliferous, the principal shells being Oslrea aellceformis and a few Pectens. The clayey sandy pai'ts, together about 18 ft. 12. Light gray calcareous clay similar to the upper part of the preceding bed, with hard, sandy ledges at the top and bottom 7 ft. II. Light yellowish gray calcareous sands, with Ostrea sellwformis and Pecteus ; the lower half indurated and full of the molds or casts of univalve shells 5 ft. 10. Light yellowish gray calcareous sauds, like those which make the upper half of bed No. 11. This bed has several hard projecting ledges of the same sandy material and contains a number of fossils : Ostrea siUceformis, fragments of Seutslla l/yelli, Scalpellum eocense, Peoten Deshayesii, etc. The sandy parts of this bed are loose, crumbliug easily between the fingers. There are thin beds of more clayey texture, one of which, about the center of the stratum, holds a number of irregularly shaped concretionary masses of clay. Near the base are one or two indurated ledges of glauconitic sand and shells of Ostrea sellce- formia i 27 ft. 9. Layer of comminuted shells of Ostrea sellceformis, together with perfect shells of some other species embedded in glauconitio or green sand 3 ft. 8. Dark bluish black sandy clay 2 ft. 7. Bluish green clayey sands vrith few fossils in the upper part, but becoming more clayey below and highly fossiliferous : Veneticardia planicosta, V. rotunda, Nucula magnifioa. Area rhomboidella, Ostrea sellwformis. Valuta Sayana, Turritella lineata, T. bellifera Aldrich, besides species of Natica, Gorbula, Cyiherea, Lucina, etc. This bed averages 10 feet or moi* in thickness. >P,S.Geol.Surv.,Bull.43,1887, p.30. »Ibid., pp.2»,30. 64 THE EOCENE. [bull. 83. 6. Dark greea sandy marl, glauconitic ; grayish above, bluish below. This bed is sometimes badly weathered aud of more brownish color. It holds a Dumber of fossils, among which the most noticeable are a peculiar small form of Veneri- cardia plauicosta Lam. and large Turritella Morloni Con. This bed,which is the lowest at Claiborne, may be seen between the upper landing and the ferry, aud its exposure is from 6 to 8 feet, according to the stage of the water. 6. [6] Dark brown sandy clays, badly weathered, highly fossiliferous, containing the same shells as beds Nos. 7 and 6 at Claiborne, viz, the peculiar small variety of Venericardiaplaniseosta Lam., large Turritella Mortoni Con., Area rlwrndoidella Lea, Lucina comprnssa Lea, Nucula magnifica Con., Tm-ritella helUfera (Aldrich), etc. This bed becomes more sandy below 8 to 1^ ft, 5. [5] Hard projecting sandy ledge 8 iu. 4. [4] Calcareous, clayey sands, light yellow when wet, nearly white when dry, glauconitic, forming smooth vertical blufif 6 to 8 ft. 3. [3] Coarse grained sandy glauconitic bed with comminuted shells aud many iinely preserved shells of uncommon occurrence 3 ft. 2. [2] Light yellow glauconitic sands capped with hard ledge 15 ft. 1. [1] Blue glauconitic sands, probably the same as No. 2 above, but less completely oxidized, lowest of Claiborne strata 5 ft. Important sections are found at Gosport Landing and Rattlesnake Bluff, on the Alabama Eiver, and at Ooffeeville Landing, on the Tom- bigbee Eiver, as well as at other points in Choctaw, Washington, Clarke, and Monroe Counties. On the Chattahoochee Eiver Langdon' states that the Claiborne is represented by the Ostrea sallceformis zone alone, which persists across Alabama with a thickness of about 75 feet, occurring as a bed of gray calcareous sand. White limestone. — Under this division are included deposits that have hitherto been generally designated as the Jackson and Vicksburg groups, terms derived from Mississippi localities, where strataof similar age are more extensively represented. That there is little distinctive difference in the fauna of these two horizons has been shown by the fossils which have recently been collected in Alabama by Mr. T. H. Aldrich, as well as "the finding by him of Gardita planicosta in the uppermost beds of the White limestone near Claiborne." Smith aud Johnson ^ state that although certain paleontological and lithological differences may be observed in the two portions of the series, these dif- ferences do not justify the division of a formation which in Alabama so clearly presents itself as a unit. Moreover, overlying the Jackson and Vicksburg groups a third horizon has been recognized by them and designated the Coral limestone. The term White limestone, which includes these three subdivisions, was early employed by Tuomey' with much the present significance, although later used by Heilprin* lor the lower or Jackson group- only. The literature of the White limestone is rather confusing, owing to the fact that the stratigraphical position of the Zeuglodon beds was ' Geol. Soo. America, Bull., vol.2, 1891, pp. 597,508. 2 IT. S. Geol. Suiv., Bull.. 43, 1887, p. 19. ' Geol. Surv., Alabama, 1st Bion. Kept., 1850, p. 154. « Contrib. Teit. Geol. and Pal. U. S., 1884, p. 33. CLARK.] ALABAMA. 65 not early recognized. Conrad held that the Zenglodoii and Orbitoides were referable to deposits of the same ags. Lyell ^ was the first to properly distinguish the two horizons and to assign to the Zeuglodon beds (Jackson) their real position below the Orbitoides limestone CVicksburg). The same fact was also recognized by Hale '^ and strongly insisted on by Hilgard^ and most subsequent writers. The general features of the White limestone are described in the fol- lowing terms by Smith and Johnson :* It consists chiefly of regularly bedded, impure limestone, with intercalated layers of marl, calcareous clay and saud, aud some ledges of pure limestone. Its npper portion is perceptibly more calcareous than the lower, aud contains a notably greater proportion of deep sea fossils; but neither the lithologic nor the paleontologic fea- tures are sufficiently distinct to warrant division of the formation. Its position and its structure alike indicate that it was laid down in a deep aud probably deepening sea. The different subdivisions of the White limestone are further de- scribed in detail.^ The lotcer division of the White limestone, about 60 feet in thickness, is in general terms a light colored argillaceous limestone, resembling the Rotten liiiiestoue of the Cretaceous formation both in the character of the rock and in that of the soils to which it gives rise on disintegration. It is traversed by thin bands of tolerably pure white limestone, and by beds of slightly calcareous clay, the latter often inipregualed with gypsnm. In places it isstrongly glauconitic. This division contains a greater variety of fossils than either of the other two, though probably a smaller number. The fossils appear in general to be much more abiindaut in the upper half of the rock, where the more commonly occurring species are Peoten xicrpianus Mort., Spondylua dumosm Mort., Ostrea cretaeea Mort., sharks' teeth, bones of Zeuglodon ectoides, and Ttrebratula lachrijma Mort. This upper and most highly foasiliferous part holds cal- careous clays which are strongly phosphatic and occasionally well filled with phos- phatio or coprolitic nodules. The lower half of this division, while less fossiliferous than the preceding, has, in nearly every locality examined, a bed near its base at least 3 feet in thickness holding vast numbers of Soutella Lyelli Con. This, which we have called the Scutella bed, has often served us as a guide in the study of this formation in the field, since it overlies by a few feet only the Claiborne fossiliferous sands. The middle ■division of the White limestone has a thickness of at least 140 feet. Lithologioally it varies considerably, being in part a hard, crystalline limestone weathering into rough, irregularly shaped pieces, which have suggested the name "horse bone" rock, popularly used to designate it. Another variety is a soft, some- times pulverulent mass of nearly pure carbonate of Ume, which is everywhere quar- ried for building purposes. When fresh, this rock may easily be cut with an ax or a saw, but it hardens on exposure to the air and lasts for many years in ohinineys and pillars to houses. This part of the White limestone contains as a characteristic fossil Orbitoides Mantelli, often in such numbers that the rock is little more than a mass of the disks of Orbitoides packed in soft, white carbonate of lime. The Orbit- oides are most abundant in the upper two-thirds of this division, becoming less and less abundant below this. The uppermost division, 1.50 feet in thickness, has as yet been observed in one locality only, viz, at Salt Mountain at the Middle Salt Works in Clarke County. ' Am. .Jonr. Sci., 2d ser., vol. i, 1847, pp. 186-191. = Ibid., vol. 6, 1848, pp. 354-363. 3 Ibid., vol. 43, 1867, p. 29-31. ■■ TJ. S. Geol. Siirv., Bull. 43, 1887, p. 134. 'Ibid., pp. 20, 21. 5uU. 83 5 66 THE EOCENE. [bull. 83. The rock here la a hard, white limestone, composed in great measure of masses of corals partly silicified. Near the base of this rock there occur great numbers of the - spines and plates of echinoderms. The White limestone is widely represeuted in Choctaw, Washington, Clarke, Monroe, Conecuh, Covington, and Geneva Counties. The White limeslTDne of the Chattahootchee section, according to Langdou, is represented by both the Jackson and Vicksburg, though " it loses its distinctiveness as Jackson and Vicksburg, and may well be included under one head.'" It is estimated to attain a thickness of 275 feet, MISSISSIPPI. The Eocene of Mississippi covers a wide area in the central and northern portions of the State. The publications of Prof. E. W. Hil- gard, whose exhaustive investigations have extended ovfer fully 40 years, afford the chief source of information upon the geology of this area. The boundary of the Eocene upon the north and east passes in a curve northwest to north, through Kemper, Noxubee, Oktibbeha, Clay, Chickasaw, Pontotoc, Union, and Tippah Counties, near Macon, Stark-" ville, Houston, and Eipley. Upon the south the boundary passes in a somewhat sinuous line through Wayne, Jones, Jasper, Smith, Eankin, Hinds, and Warren Counties, and somewhat to the south of Wayne- boro, Jackson, and Vicksburg', The Eocene overlies the Cretaceous upon the north and east, which it succeeds in its various horizons regularly from northeast to south- west. The relations of the deposits are described by Hilgard, in his Keport on the Geology and Agriculture of the State of Mississippi. He says : The position of the Tertiary strata appears to be more or less in conformity with that of the Cretaceous beds. It certainly is so in the southern portion of the State, where their dip is distinctly southward. Whether or not the same is true in refer- ence to the strata occupying the northern portion of the State I have thus far been unable to determine, iu consequence both of the rare accessibility of the strata and their character. If, however, any westerly dip exists in the Tertiary strata of northern Mississippi (as is the case in the Cretaceous strata) it is certainly much less than that of the latter. In a later publication ^ the same writer estimates the dip in the north as 4 to 5 feet in the mile toward the west ; iu the south 10 to 12 feet in the mile toward the south. In the official report fiist referred to, the lithological character of the Eocene is thus described : It exhibits, esseutially, three different facies, viz, that of lignitiferous clays and sands, varying in color from black to brown, blue, green, yellow, gray, and almost white, with remains of vegetables ; that of siliceous sandstones and claystonos with marine fossils ; and that of liniestone and calcareous marls, with marine fossils. Although these three divisions correspond in the main with the lead- ing stratigraphical divisions of the Eocene, yet many modifications ' Geol. Soc. America, Hull., vol. 3, 1891, p. GOO. » Am. Jour. Sci., ad scr., vol. «, 1867, jj. 3q. Ct.AKK.] MISSISSIPPI. 67 occur in the series. The lignitic phase has often bands of sand- stone intercalated which contain marine fossils, while " the several- marine stages are separated by intervening strata of dark colored, often lignitic clays." This peculiarity is not confined alone to the sands and sandstones, but is likewise found in the calcareous beds. The follow- ing generalized section, changed but slightly from that given by Hil- gard in the report above mentioned, is presented in descending scale : ViCKSBUKG. Crystalline llmestoues and marls with, Ostrea, vickshurqmisis, Ostrea giyaniea, Peclen Poulsoni, Area mississippiensis, Navioula mississippiensis, Navioida lima, Crassatella mississip2>iensis, Cardium dirersum, Panopwa oblongata, Dental'mm mississippiensis, Fulgoria mississippiensis, Cyprwa Uiitea, Madrepora mississippienais, Orhitoides ManielU 80 feet. Ferruginous rock of Keel Bluff, with Plagiostoma dumosa, etc 12 feet. Lignitic clay and lignite, at Vicksburg and north of Brandon 20 feet. Jackson. White (often indurate) and blue marls with. Zeuglodon macrospon- di/lus, etc. Lignitic clay and lignite, at Jackson, Garlandsville, Coounpy Creek 80 feet. Claiborne (Calcareous Claiborne). White (sometimes indurate) and blue marls with Ostrea oellceformis, etc. Lignitic clays and sands of northern Clarke County. BuHRSTONB (Siliceous Claiborne). Sandstones and claystones with Cardita planicosta, etc. Found in Neslioba, Newton, Lauderdale, and Clarke Counties. Lignitic. Lignitiferous strata with interstratified beds of brown, yellow, and gray sands and clays containing marine fossils and plant remains. Quercus sp., etc. Cardita planicosta, etc. Lignitic. —The term lignitic, first employed by Hilgard to designate the deposits now under consideration, had, under the name " the ITorthern Lignitic," much the same stratigraphical significance that it has received in the present report. Heilprin has suggested the use of Eoliguitic, but the earlier term is here retained. Although there seems to be but little doubt as to the stratigraphical position of the greater part of the deposits here referred to the Lignitic, the evidence is somewhat couflicting as to other por- tions. Much more exhaustive examinations must be made before all the lignitic strata can be assigned to their proper horizons. The de- posits of undoubted Lignitic age have been observed to dip below the Buiirstone, and further afford specimens of Gardita planicosta, Aturia ziczae, and other early Eocene forms. The Lignitic occupies a much wider area than any other member of the Eocene series. It covers the whole or portions of Lauderdale, Kemper, Neshoba, Leake. Madison, Yazoo, Holmes, Attala, Winston, Noxubee, Oktibbeha, Clny, Webster, Choc- taw, Montgomery, Carroll, Grenada, Tallahatchee, Yallabusha, Cal- houn, Chickasaw, Pontotoc, Union, Lafayette, Panola, Tate, De Soto, Marshall, Benton, and Tippah Counties. The northeastern portion of the area bordering the Cretaceous has b'een designated by Hilgard the "Flatwoods." The deposits are gray or whitish, ol ten laminated clays. The Lignitic strata to the west of this area are thus described by Hilgard: 68 THE EOCENE. | bull. 83. Westward of the Flatwoods proper, however, the clays are commonly laminated, less uniform in their cha.racter, and iuterstratified more or less with the sand. Such usually are the clays associated with the lignite heds aud containing impressions of leaves ; nevertheless, the genuine " Flatwoods clay " character frequently reappears over the whole region. » » » Through these clay stones any sign of lithological transitions, from the pure almost white clay to the fossiliferous sandstone of Tippah County, may be traced, and careful examination will sometimes detect in them une- quivocal remnants of marine fossils. * * » In short, the greatest diversity of ma- terial generally obtains in connection with the lignite beds. Buhrstone. — The Buhrstone called Siliceous Claiborne by Hilgard is characterized by aluminous sandstones and claystones. It is found chiefly in the eastern portion of the State aud extends from the Ala- bama State line across Clarke, Lauderdale, Newton, and Neshoba Counties iato Scott and Leake Counties, occurring also as an outlier in Attala, Holmes, Choctaw, Montgomery, and Carroll Counties. Its strati graphical position below the Claiborne and above theLignitic has been fully established, and among its more important fossils are Ostrea divaricata, Gardita planicosta, Gardita rotunda, Gardium Nicolleti and Valuta petrosa. Hilgard corroborates the statements of Tuoraey and Conrad of the division of the Buhrstone into two horizons, but the iuvestigations have hardly been exhaustive enough as yet to admit of their final acceptance. Glaiborne. — The Claiborne, or as it is designated by Hilgard, the Cal- careous Claiborne, is poorly represented in Mississippi. So far as its presence-has been reported it is found mainly in Clarke County, although Hilgard, in an article in the American Journal of Science in 1867, states that he has " received evidence that it extends somewhat farther west- ward, between the territory of the Jackson and Siliceous Claiborne groups, than it appears on the map" in his State report. As a group the strata are not very sharply defined " inasmuch as the transition from siliceous to calcareous materials is a gradual one" and on this ac- count the Claiborne deposits occupy a somewhat intermediatii position lithologically between the Buhrstone and the Jackson. The beds are chiefly blue and white marls, the latter generally arena- ceous and often indurated. The fossils of this horizon are so poorly preserved that but few have been recognized. Among those reported by Hilgard are Ostrea divaricata, Ostrea sellceformis, Pecten Lyelli, Gov- bula gibbosa, and Voluta petrosa. Jaelcson. — This division of the Eocene was first recognized in Missis- sippi by Conrad, 1 who described an extensive collection of fossils from the neighborhood of Jackson and first employed that name to desig- nate the horizon since so called. He assigned to the strata their proper stratigraphical position above the Claiborne aud below the Vicksburg, although from the nature of the material he had for exami- nation he failed to recognize the true faunal relationship of the several horizons. His investigations leil him to the conclusion that there were 'PliilaaolpUia Acad. Nat. Soi., Proc, vol 7, 1855, pp. 257-263. CLAEK.) MISSISSIPPI. 69 no forms in common with the Vicksburg series and but four or five with the Claiborne. Subsequent observations, however, have shown in Mississippi, as well as in Alabama, that there are many forms common to the three horizons. Such common species as Gardita planioosta and Gardita rotunda of the Claiborne, with many less usual types, are found, while the list of species reported as likewise occurring in the Vicks- burg is very large. The most distinctive fossil of the Jackson beds is the Zeuglodon, which, as already stated under Alabama, had been re- ported by Conrad and others to occur at the same horizon with Orbi- toid^s, though this was denied by Hilgard. If such intermingling has been locally found it is explained probably on the ground of subse- quent rearrangement of the deposits. The Jackson beds are composed " at times of a soft yellowish lime- stone or indurate marl containing a good deal of clay ; at others of, in reality, nothing more than soft gray or jellowish calcareous clay." Hilgard recognizes two horizons, an upper of about 70 feet of marl or clay in which the bones of the Zeuglodon are prominent, and a lower of 10-20 feet of bluish sandy strata, containing green-sand grains. It is the lower horizon that is developed at Jackson and contains the impor- tant series of fossils described by Conrad. In this lower division beds of lignite are conspicuously developed at several points. The Jackson deposits extend as a band of varying width from Wayne acros^ Clarke, Jasper, Smith, Scott, Eankin, and Madison Counties, into Yazoo, where they disappear below the alluvium of the Mississippi. Viokshurg. — The Vicksburg strata extend as a narrow band across the State south of the region occupied by the Jackson group, and pass through Wayne, Jasper, Smith, Bankin, Hinds, and Warren Counties, reaching the Mississippi Eiver at Vicksburg Bluff. As stated in a previous paragraph, the Vicksburg group is both lith- ologically and paleontologically closely associated with the Jackson. This is shown most clearly when the section exposed at Bed Bluff in Wayne County is considered. The intermediate deposits there exhib- ited, which Hilgard thought sufiSciently important to establish as a sub- group of the Vicksburg series, contain a most interesting association of typical Jackson and Vicksburg forms (the latter predominating), to- gether with a large number of species peculiar to the horizon. Ooarad, who had examined beds on the Savannah Eiver at Shell Bluff, held that this division (Red Bluff group of Hilgard), in which the same spe- cies of oyster {Ostrea georgiana) was reported to occur, was of the san)e age and, moreovfer, that its position was between the Claiborne and Jackson. He called the formation the Shell Bluff group.^ In the American Journal of Science for 1866, Hilgard^ opposed the opinions of Conrad and showed the proper position of the deposits in Mississippi to be at the base of the Vicksburg. Tiie strata of this horizon are ■Am. Jonr. Soi., M ser,, vol. 41, 1866, p. 96. "Ibid., Tol. 42, 1866, pp. 68-70. 70 THE EOCENE. fBULi-SS. never of great thickness, and at Red Bluif Station, Wayne County, where typically developed, are only about 4 feet thick. At this point, the beds consist of " irregular masses of fine grained, ferruginous rock, imbedded in a brownish or greenish clayey mass." The deposits of the Vicksburg group proper consist chiefly of lime- stones, marls, and clays, which are frequently arenaceous and at times glauconitic. The chauge is often very marked, for, as Hilgard states, " not only do the materials of the different groups often bear a most extraordinary resemblance to each other, but their character varies in- cessantly in one and the same stratum within short distances." The typical fossil is the Orbitoides. Conrad, although at first recog- nizing in its fossils the close relationship of the Orbitoides limestone with the beds exposed at Vicksburg bluff', was later' of the opinion that the- faunas should be separated and the former associated with the Jackson group. Subsequent investigation has shown the error of this position, for the Orbitoides has been found in sufficient numbers mingled with the other characteristic Vicksburg forms, to prove the identity of the deposits. The following section of the Vicksburg Bluff is given in its main details as found in the State report of Uilgard: 7. Bluff formation 10-aO ft. 6. Orange Sand 5-20ft. '.'i. Alternating strata, 1 to 6 feet thick of limestone ^ . and marl, containing the Vioksljurg fossils, and some bands of non-effervescent, gray sand and clay 60-65 ft. ■ 4. Black lignitic clay, and gray sand, with Ostcrea gi- Vickshurg gronp-.'J gantea, Corbula alia, Natica mississippiensis, Gyth- erea solrina, Madrepora mississippiensis 5 ft. 3. Gray or black lignitic clays and sand, with iron pyrites; exuding salts and sulpliureted hydrogen 25 ft. .2. Solid lustrous lignite, with whitish cleavage planes 3 ft. 1. White limestone of the Jackson group ? 3 ft. TENNESSEE. The Eocene of Mississippi, which reaches the northern boundai'y of that State, continues in a southwest-northeast direction across the western part of Tennessee. It has been reported to cover much of the area lying between the Tennessee River on the east and the Mississippi River on the west, and has been found to outcrop at several localities on the bluffs of the latter stream. It has been estimated to attain a width of quite 50 miles, but with the fragmentary data at hand the exact delimitation of the formation is in much doubt. The several official reports of Troost upon the Geology of Tennessee barely touch upon the Eocene. Considerable attention, however, is given to this portion of the State by Saffbrd, though the recent investi- gations of McGee tend to show that much that has been hitherto held to belong to the Eocene series must be referred to later horizons. Safford,^ whose authority has been followed up to this time, divides ' Am. Jour. ScL, 2(1 8cr., vol. 41, 1880, p. 90. "Ani.Joar.Sci.,2dser., vol.37, 1864, pp.300-372. Geology of Tenuosaee, 1809, pp. 422-428. CLAUK.I TENNESSEE — KENTUCKY. 71 the scries iuto two groups which he terms I. The Porter's Creek group, II. The La Grange group. The Upper or La Grange group McGee has recently correlated with the Appomattox formation of the Atlantic slope, so that a large part of the deposits hitherto referred to the Eocene has been given by him a much more recent origin. The Bluff Lignite group, which Safford doubtfully referred to the Tertiary and placed above the La Grange group, is held by Loughridge' to be a phase of the Porter's Creek: group. McGee, on the other hand, con- siders it Pleistocene. It will thus be seen that the various authorities upon the geology of western Tennessee vary widely lu their opinions. The problems here presented for solution have to be determined almost wholly on stratigraphical data due to the absence of distinctive fossils. In short, with the exception of a somewhat limited ilora, which has not as yet received much study, and a few poorly preserved mol- luscau remains, there is nothing of a paleontological character to aid in the determination of the geological horizons represented. The Lig- nitic (Porter's Creek group) is probably, however, the single member ot the Eocene series found in Tennessee. In its lithological characters it has much in common with the same formation found in Mississippi. The Platwoods phase, with its laminated and aluminous structure, is widely represented. Arenaceous and liguitic strata likewise occur. We have much yet to learn of the Eocene of Tennessee, however, be- fore its distinctive features can be at all accurately defined. KENTUCKY. The Eocene of Kt^utucky is the northward extension of the Tennes- see formation and presents much the same character's as its more south- ern representative. It occupies that portion of the State lying between the Tennessee and Mississippi Elvers and the same divisions in the series have been found to occur as in Tennessee. It has been hitherto stated, however, that McGee correlates the La Grange group with the Appomattox and refers the Bluff Lignite to the Pleistocene, although the latter is by Loughridge considered to be a phase of the Porter's Oreelj group. The Eocene series as subdivided by Loughridge^ in his Keport upon the Jackson Purchase Region is as follows in descending order: 3. La Grange group (of Safford's Tennessee). 2. Liguitic (Safford's Porter's Creek and Bluff Lignite). 1. Hickman (provisional). The Hiekman group, the lowest member of the Eocene, which Lough- ridge has i^rovisionally established, is found chiefly in the vicinity of Hickman, where exposures occur "in the bluff bordering the Missis- sippi bottom from Hickman south into Tennessee." In evidence that ■Geol. Surv. Kentucky, Eept. Jackson PurchasB Eegion, 1888, p. 41. •.Ibid, p. 37. 72 THE EOCENE. [bull. 83. the deposits at Hickman are older than the Lignitic the anther saj.s : "These exposures are eoibraced in a belt of country 5 miles west of a line running south from the lignitic outcrops at Columbus, and both of the formations have an apparent slight easterly and northwesterly dip, which would carry the Hickman beds much below those of Columbus," The deposits consist of clay, sand, and gravel, but have not been ex- posed to their base. The Lignitic group, which, according to Loughridge, is the equivalent of Safiford's Porter's Creek group — enters from Tennessee willi a widtli of abont 10 miles, passes northward through the middle of Calloway County, soon bends to the northwest through the southwest cor- ner of Marshall, and passes diagonally through the center of McCracken and I he northernpart of Ballard County into Illinois ; southward along the Mississippi River bluffs, its first oul crops occur 2 miles north of Wickliffe, Ballard Couuty, and in the bluffs between Wickliffe and Fort Jefferson reaching eastward 7 miles to Bland ville and southward to Laketon ; at Columbus and a mile above, and also at Chalk Bluff, 2 miles south, the greatest exposures of the lignitic beds occur. Loughridge characterizes the group lithologically as follows : • First. — A lower heavy bed of massivd joint clay, black when wet, but drying to a lead-gray color, and on exposure to air crumbling to a fine shaly mass. This is tlie Porter's Creek group of the Tennessee series. It is popularly called soapslone. Along the Mississippi River bluffs the clays, while dark and somewhat joiuty, arc more sandy than those on the eastern aide of the region. Second. — An upper bed of dark sandy clay, holding two layers of lignite, each va- rying from 2 to 4 feet in thickness, the topmost being about 5 feet from the surface of the formations. This upper or lignitic portion of the group, while perhaps at oue time continuous from the Mississippi River eastward nearly to the Cretaceous, has now almost disappeared on the east, oatcropping only on Panther Creek, 6 miles oast of Mayfleld, in Graves County On the west, however, in the neighborhood of Wick- liffe, the lignite beds reach for 3 miles to north and south, and for 7 miles eastward to Blaudville. Loughridge gives the following section which shows the character of the several members comprising the group : Seetion of the Lignitic group. Feet. Dark sandy clays ■ ,. 3 Lignite bed 4 Dark sandy clays - 5 Lignite bed ;? Dark sandy clays 3 Clay stoue with fossil-leaf impressions 2 Dark sandy clay, the upper holding leaf impressions 2 Micaceous sandstone with fossil casts 3 Black joint clay, changing to dark sandy clay 100 The paleontological evidence, with the exception of a few poorly pre- served molluscan remains from the micaceous sandstone near Paducah, depends entirely upon fossil leaves, of which a considerable number have been described by Lesquereux from the beds near Columbus' and Wickliffe.^ The molluscan forms, five in number, Mysia ungulina (?), 'Am. Sovlt. Sci., 2J set., vol. 27, 1859. »TJ. S. National Museum Proc, vol. 11, 1888, pp. 11-13. o-AiiK.] ILLINOIS — MISSOURL 73 Ledaprotexta (?), Leda sp., Wiicula ovula (?), aud Turritella Mortoni are described by Heilpriiii in the Proceedings of the Academy of Natural Science, of Philadelphia, as occurring " mainly in the form of casts in a highly ferruginous and fairly micaceous yellow-white sandstone." The non-occurrence of Lignitic strata in the area between the eastern and western outcrops above described is accounted for by the removal of the deposits and " the filling up of the gap by the La Grange beds." "^ This is considered probable from the fact that the Ea Grange is found at depths below the level of the Liguitic deposits. The wide surface covering of more recent deposits limits the exami- nation of the Pjocene to the exposures afforded by streams and well borings. In Geology, vol. 1 of the Keports of the Geological Survey of Illinois, certain deposits in the southern portions of the State, in Massac, Pulaski, and Alexander Counties, are referred to the Tertiary. They consist of gravels, sands, and clays that are at times cemented into a ferruginous conglomerate. In Pulaski County, a bed of greensand marl occurs, with casts of marine shells that are referred by Wor- then to the genera Cuculltea and Turritella. The bluff at Caledonia, on the Ohio Eiver, affords a fine section of Tertiary strata 100 feet in thickness. Worthen states that a thin bed of lignite is found at the water's edge. Loughridge, who visited the locality at high water, states that.the basal member is " greensand (glauconite) with hyoline sand ; also, some black sand and clay, 2 to 4 feet." Overlying this he mentions the occurrence of " 75 feet of the dark joint clay weathering to a gray shale and similar in every regard to the clay beds of the lig- nitic." The presence of 20 fee,t of " dark, sandy clay, indurated " above the joint clay is further stated. This is supposed by Loughridge to represent the micaceous sandstone of the Paducah series. Worthen is of the opinion that the Tertiary strata may have extended along the basin of the Mississippi as far north, at least, as Hancock County, since the occurrence there of shark's teeth in the alluvial de- posits can be explained only on the ground of subsequent rearrange- ment of earlier marine deposits. It seems probable that the various deposits here referred to are the northward extension of the Lignitic represented in Tennessee and Kentucky and described in the previous pages. MISSOURI. Little more than the bare statement of the occurrence of Eocene in the southeastern portion of the State is found In the literature. That the strata partake of the character of the deposits in Kentucky aud ' Philadelpbia Acad. Nat. Sei. Proc, toI. 38, 1886, pp. 57, 58. 2 GeoL Sarv. Kentucky, Rept. Jackson Purchase Ilegion, 1888, p. 51. 74 THE EOCENE. [bull. 83. llliuois, which collectively outliae in ii yeiioral way the head of the Mississippi embaymeut ia early Tertiai-y times, is recognized. The out- crops are found chiefly in Mississi ppi and New Madrid Counties. So far as known, the strata are entirely confined to the Lignitic. No fossils have been reported from the beds, and even the stratigraphical relations of the deposits themselves are very imi)erfectly understood. ARKANSAS. Our knowledge of the Eocene of Arkansas is confined chiefly to a small area in the southwestern portion of the State that has lately been investigated by Prof. Robert T. Hill.' The earlier reports of David Dale Owen, State Geologist of Arkan- sas, contain many casual references to Tertiary deposits, in the eastern and southern counties, a portion of which can be shown to be Eocene, while the remainder are to be referred in part to older, in part to younger formations. The Tertiary area examined by Hill includes portions of Hot Springs, Dallas, Olark, Howard, Hempstead, Nevada, Ouachita, Columbia, La Fayette, and Miller Counties, and the sections are found for the most part along the Ouachita and Eed Rivers and their tribu- taries. The inland border of the formation is found to extend in an irregular line from southwest to northeast, a short distance to the west of the Iron Mountain Railway and passes near Texarkana, Washington, Arkadelphia, and Malvern. From the scattered data accessible for the remainder of the State it seems probable that this line extends in ap- proximately the same direction toward the northeast, past Little Eock to the Missouri border. The lignitic formation of this area has been designated by Hill the " Camden series." He describes it as 'i an extensive, shallow-water, Tuarine formation of stratified, micaceous, non indurated, alternating laminae of sands and clay shales, sandy shales occasionally accompanied by bituminous shales, lignitic shales, thin sandstones (quartzites), etc.^" The series takes its name from the town of Camden on the Ouachita River, near which the most typical exposure is found. The following section is from Hill's report : 8. Surface soil (residuum of substructure) lerriigiuous sandy 5Jt. 7. Laminated sand, witli green-sand specks, originally white, but ferruginating and cementing into red iron sandstone, with a tendency to slialy disinte- gration on exjiosure 32 ft. 6. Little Missouri lignites, or ligneous shales, wi th white sand between layers of the same character as those seen at the mouth of the Little Missouri 20 ft. 5. Bnff-colored, micaceous sand and clay shales, changing on exposure to pink and light yellow 10 ft. 4. Bitnraiuous shales, with .bituminous masses and asphalt-like concretions. This str.itum is full of concretions of iron pyrites, which oxidize on ex- posure, coloring the neighboring strata red 15 ft. ■Geol. Surv. Arkansas, Ann. Eept. for 1888, vol. 2, pp. 48-65. 'Ibid., p. 49. CLARK] ARKANSAS LOUISIANA. 75 3. Light drab, fine, micaceous sands or sandy clays, liuely laminated SS ft. 2. Concealed 25 ft. 1. Repetition of No. 3 to the water line 10 ft. In the Aneinity of Arkadelpliia are clei)osits " consisting of alternate bands of blue clay and white or orange-colored sands" that occupy a position below the Gamden seines as exhibited at Camden. They rest nnconformably uphn the Cretaceous, and have received the name of "Arkadelphia shales" from Hill. Hill states that there are many other outcrops within the area that afford deposits similar to the Camden section, but that, judging from the dip, it is not probable that the strata are identical. On the con- trary, they represent alternating conditions in the deposition of an ex- tensive series of beds. The thicknees of the Camden series can not be accurately given, but it is estimated to be quite 700 feet between Curtis and Camden. At the latter point, 300 feet more are exposed from low water to the top of the highest hills. Owen mentions the occurrence in tlie central and northeastern por- tions of the State in Jefferson, St. Francis, Green, and other counties of lignitic strata that are doubtless the northern continuation of the belt represented by the Camden series of the S(juthwest. The " Cleveland county red lands" described by Hill, though litho- logically similar to the typical Camden series, are "accompanied by extensive deposits of marine shells and greensand which bring into these strata an ingredient of lime, an ingredient which is conspicuously lacking in the underlying beds." Oardita planioosta, Rostellaria velata, and other forms, found also at Claiborne show the probable position that these beds hold in the Eocene series. At White Bluffs, on the Arkansas Eiver, in Jefferson County, Owen mentions a section of Eocene shell marl 50 to 60 feet in thickness containing many Claiborne types. From the evidence thus afforded the presence of the Lignitic and Claiborne are established, while it is probable that the Buhrstone also occurs. The White limestone is undoubtedly lacking. LOUISIANA. The reports of Hopkins and Hilgard, that of the former to the gen- eral assembly as State geologist, that of the latter to the New Orleans Academy of Sciences, afford the chief sources of information upon the Eocene geology of Louisiana. As the investigations were hurriedly conducted, admitting in neither case of an extended examination of the deposits, there is much yet to be desired before approximate limits may be given to the several formations, or even the horizons themselves de- finitely determined. The Eocene strata are found to the north of a line extending from the Sabine Eiver near the mouth of Bayou Toneau, through Sabine and Natchitoches Counties, crossing the Red Eiver near Oloutierville, 76 THE EOCENE, [boll. 83. thence through Grant and Catahoula Counties to near Stafford Point on the west bank of the Ouachita Eiver. To the east of the Ouachita .River the Eocene is covered by the alluvial deposits of the Mississippi. North of this southern boundary line the strata extends to the Arkansas border. All the main divisions of the Eocene are probably represented, al- though we have definite knowledge of but two, the Vicksburg and Jackson. Hilgard describes, under the name of " The Mansfield growp,^ a series of beds consisting of lignites, sands, and clays that he states in his first report in part at least overlie deposits with characteristic Jack- son fossils. In the final report these deposits are shown to be largely Jackson. Hopkins, about the same time, suggests the identity of a part of the Mansfield group with the " Northern Lignite." Hill, in his Ark- ansas report, states that similar deposits in Arkansas which he assigns to the Lignitic, and calls the Camden series, represent certainly in part the Mansfield group of Hilgard. If, upon further examination, such proves to be the case, we have in the lignitic strata of northwestern Louisiana the Lignitic represented. That lignitic strata occur at dif- ferent horizons, as in Mississippi, is beyond doubt, and it may be that the Mansfield group contains representatives of all the divisions from the Lignitic to the Jackson. Too little is known to make positive state- ments upon this point. Jachson. — The northern limits of the Jackson group, as finally estab- lished, will depend upon the amount of lignitic strata that will be as- signed to earlier bori/ons. In addition to the lignites, with their inter- stratified sands and sandy clays, are marine strata, consisting of marls, ' clays, and sands with numerous typical molluscan forms, and at two localities (Grandview on the Ouachita Eiver, and Montgomery, Grant Parish), the remains of Zeuglodon. Vickshurg. — The limits of the Vicksburg group have been more accu- rately determined. The strata occupy a b§lt of country 10 to 12 miles in width, extending from the Ouachita Eiver to the Sabine, and passing through Catahoula, Winn, Grant, Natchitoches, and Sabine Counties, The deposits consist chiefly of yellow and red clays, at times sandy and often very calcareous from the presence of large numbers of lime- stone nodules, that are filled with casts of shells, Lignitic strata are not altogether absent, though infrequent. Many characteristic Vicks- burg fossils have been reported from the different portions of the area, including Orbitoides Mantelli and Peeten Poulsoni, TEXAS. The first information that is afforded us concerning the occurrence of Eocene strata in the State of Texas is presented by Eoemer in his work entitled "Texas," etc, published in 1849. At Wheelock, Caldwell ci-AKK.] TEXAS. 77 County, he found fossils that he considered identical with those at Clai- borne, Alabama. ■ From this he drew the conclasion that — It, is hardly to be believed that this Tertiary formation is limited ouly to this point oil the Brazos, in Texas, but most probably it is part of a continuous band, as is the case in Mississippi and Alabama, extending alonj; tlie foot of the Cretaceous, and only the detritus of the later alluvial formations prevents its exposure in most places.' The supposed limits of the formations are given on a map appended to the volume. The later geological notes on this region by Schott, Hall, Conrad, Shumard, and Buckley are very meager and unsatisfac- tory, and give us hardly more than a general idea as to the position of the Tertiary.^ Loughridge, in a " Report on the Cotton Production of the State of Texas" ^ of the Tenth Census, gives the general bound- aries of the Eocene, although its westward deflection in the drainage of the Rio Grande, adopted on most recent maps, has been lately shown to be erroneous,' Hill states that the mistake originated because Conrad referred a specimen of Cardita planicosta to a locality (Arroyo de las ^inas) in Zavalla County, which, however, upon examination, shows, in the handwriting of the collector, that it came from Mexico. Heilpriu presents an excellent general statement of the stratigraph- ical relations of the Texas Eocene, so far as they were known up to 1884^, in his "Contributions to the Tertiary Geology and Paleontology of the Dnited States." Hill quotes largely from the same work, so far as it relates to the Eocene, in his general summary of " The Present Conditions of Knowledge of the Geology of Texas."* A recent publication of Dr. R. A. P. Penrose, jr., entitled "A Prelimi- nary Report on the Geology of the Gulf Tertiary of Texas, from the Red River to the Rio Grande," in the First Annual Report of the Geological Survey of Texas for 1889, gives us the results of the first systematic study of the Tertiary formations of eastern Texas. The line separating the Cretaceous and Eocene, he states, runs in a general northeast and south- west direction, crossing the Red River west of Texarkana, the Texas and Pacific Railroad between Corsicana and the Trinity River, the Brazos River in the northeast coiner of Milam County, the Colorado River 10 miles below Austin, and the Rio Grande River in the north- west corner of Webb County, 3 miles below the Maverick County line and half way between Eagle Pass and Laredo. Concerning the difficulty of definitely establishing the boundary be- tween the Cretaceous and Tertiary, Penrose says : The uppermost part of the Cretaceous and the base of the Tertiary strata are both composed of soft clay and sand beds, -which succumb readily to the weathering action of the atmosphere and consequently the line of separation is often impossible to lo- cate exactly. ' Texas, etc., 1849, p. 372, and U. S. Gool. Surv., Bull. 45, 1887, p. 17. ' Tentli, Census of the TJ. S., vol. 5, 1884, pp. 653-83X. »U. S. Geol. Surv., Bull. 45, 1887, p. 85. • TJ. S. Geol. Sai-v., Bull. 45, 1887. 78 THE EOCENE. [ecu. 83. As regards tlie composition and origin of the strata he says : The Tertiary deposits consist of avast thickuess of sand, clay, and glaucdnite beds, in some places cliaraoterized by great quantities of lignite, and in others by beds of littoral fossils. In fact the whole series represents a succession of coastal, subcoastal, or brackish water deposits, alternating with marine deposits of a littoral character, and between these two extremes we fiud all gradations. The lagoon or subcoastal deposits compose by far the greater part of the series, and the mariue strata repre- sent slight and temporary submergencies of the coastal area. The strike of the strata is northeast to southwest and the dip from 0° to 5° toward the southeast, although local variations in the latter are reported by Penrose by which at times the dip is west or northwest, and one instance in the vicinity of San Tgnacio on the Rio Grande, where for 21 miles the dip is towards the northeast. The strata have been estimated to attain a thickness of 1,000 to 1,300 feet. Penrose divides the deposits into two horizons, whiph are given below in de- scending order. 2. The Timber Belt or Sabine Eiver beds. 1. The Basal or Wills Point clays. The lower division, the Basal or Wills Point Glays, are composed of — Stiff laminated clay, yellow, gray, blue, or bluish green iu color, frequently in- terbedded with seems and laminae of sand, containing many concretionary masses of gray nou-fossiliferous limestone. * » • No lignitie beds have been seen as yet in these clays. The deposits of this division are estimated to be 250 to 300 feet thick. They are considered by Penrose to bo absent on the Rio Grande. The upper division, the Timber Belt or Sabine River Beds, are com- posed of — Siliceous and glauconitic sands, with white, brown, and black clays. The clays, however, are greatly in the minority, and the siliceous sands comprise by far the greater part of the whole series. Liguite beds are of very frequent occurreuce, varying from a few inches to 10 and 12 feet thick. Of the areal distribution of these beds Peorose says that they "oc- cupy an area over 125 miles wide in the northeast part of the State, but thin down to less than 40 miles on the Colorado." On the Rio Grande the Timber Belt Beds are found, according to Penrose, resting directly on the Cretaceous. Dr. White, ^ however, considers that the Laramie enters into the Rio Grande section between the mariue beds of the Cretaceous and Eocene. He says : These strata (Laramie) dip gradually to the southeastward or approximately iu the direction of the river's (Rio Grande) course and disappear beneath the sandy strata of the Eocene Tertiary some 10 or la miles above Laredo. The Timber Belt or Sabiue Riverbeds are estimated to attain a thick- u^s of 800 to 1,000 feet. Although the discovery of many fossils is reported from the Texas Eocene, and the identity of several forms with the species recognized in the Alabama and Mississippi strata ■' Aiu, .fiiur. Sil, :iil aer., vol. 35, 1E88, Jip. 43^-438. CLARK.] CORRELATION OP DEPOSITS. 79 claimed, little systematic study has been given them, so that no very definite conclusions can as yet be drawn. Oardita planiGosta, that ranges so widely and is so characteristic of the Eocene in the Atlantic as well as the Gulf States, has been recognized among other typical forms. COERELATION OF DEPOSITS. There is practical uniformity of opinion at the present time as to the delimitation of the Eocene of the Atlantic and Gulf coast region. Both paleontologically and stratigraphically, the break separating the Eocene and Cretaceous is clearly defined, and except where local de- tails of geographical distribution have not been as yet finally estab- lished, the line may be drawn with comparative accuracy. Uncon- formity of contact is generally apparent, and the types of animal re- mains are so widely different as to afford at once, when present, a ready means of discrimination. The Neocene is also found unconformably overlying the Eocene and with fossil forms that at once separate the two horizons, although the distinctions are, perhaps, not so strongly marked as between the Creta- ceous and Eocene. Ou the other hand, any attempt at a wide correlation of the various divisions of the Eocene established in the different portions of the At- lantic and Gulf coast region is rendered well-nigh fruitless from our incomplete knowledge of their stratigraphy and their fossils. Only in one locality (along the Alabama and Tombigbee Elvers, Alabama) have we even an approximately accurate section of the Eocene series. The literature is filled with incomplete descriptions of local deposits, which, for purposes of widespread" correlation of the strata must be used with the greatest care. Moreover, the collections of fossils made by the many authorities cited in the previous pages of this report have been either altogether destroyed or so carelessly labeled and preserved as to be practically worthless for stratigraphical purposes. The collections of the Alabama State Survey are au exception, and I have a fragmentary series from the Atlantic coast deposits. It will thus be seen that the difficulties in the way of any general correlation of deposits are well- nigh insuperable. We are practically ignorant of the fauna, and the very foundations upon which we have to build are thus wanting. Long lists of fossils, it is true, have appeared in many articles and reports upon the region, but the establishment of auy complete system of cor- relation upon such data, is, to say the least, hazardous. Before tbe work can be satisfactorily done, careful and exhaustive collections must be made. Until that has been accomplished, a provisional statement of the more apparent similarities may not be valueless. Many such at- tempts have hitherto been made, and it is with some reluctance that the author employs such insuflicient data for widespread correlations which require the most accurate information to possess any value. In 80 THE EOCENE. (bull. 83. the introduction to this report a division of the Eocene into I, Lower; II, Middle ; III, Upper, was suggested. Although such a division of the strata can not be definitely established everywhere, it affords a scale to which the facts, so far as we know them, may be referred, and by which the complete series in Alabama may be best interpreted. In the suc- ceeding pages the generalized sections recorded in the several States will be assigned, so far as possible, to a relative position in this scale, although later observations will probably necessitate many changes. New Jersey. — The Eocene of New Jersey belongs entirely tothe*Lower division. Its Supposed close relationship to the Cretaceous, from a strati graphical standpoint, was long the cause of associating it with that horizon. Its fossils were subsequently found to possess an un- doubted Eocene character, and although lacking some of the more widely represented species, such as Gardita planieosta, Turritella Mor- toni, aud Ostrea sellceformis, still afifbrd none of the characteristic Creta- ceous forms of the underlying rocks. The character of the vertebrate bones and the moUuscan remains is a strong indication of its early Eo- cene age. Conrad ' stated this position in 1848 and more fully ex- plained the same in 1865. It has been generally held by subsequent writers. Maryland. — There is some difference of opinion as to the correlation of the Maryland deposits. The strata exhibited at Piscataway Creek, Upper Marlboro, and other points have been generally considered to hold a position well down in the Eocene series, but whether they are to be correlated with the Claiborne, Buhrstone, or Lignitic of the south has not yet been finally determined, so that it is a matter of some doubt whether the Maryland deposits should be considered Lower or Middle Eocene. It is not at all improbable that both may be represented, though we have not sufficient data for establishing a division. That the deposits of Maryland and Virginia occupy about the same horizon is pretty clearly established, both on stratigraphical and paleontolo- gical grounds. In the main the fossils are similar. Ostrea compress- irostra, Turritella Mortoni, Cytherea Meeldi, Gardita planicosta, Gucullaia gigantea, Panopwa elongata. are types frequent in both States, while Tur- ritella Mortoni, Panopcea elongata, and Gardita planicosta have a wide geographical range in other portions of the Atlantic and Gulf coast region. Unfortunately the few forms that occur have not, so far as is known, a narrowly circumscribed range geologically, Gardita planicosta, for example, ranging through the entire Eocene series. Lithologically, also, the Maryland deposits are, in their widespread green-sand facies, to be intimately associated with the Virginia strata. Virginia. — The Virginia Eocene region is, as above stated, the south- ward extension of the Maryland area. The upper strata may repre- sent a higher horizon, but of that we have little to guide us. The fossils ' Philadelphia Acad. Nat. Sci. Joar., now ser., vol. 1, 18i8, p. 129. Phlladel{)hia Acad. .NTat. Soi., Proc, Tol. 17, 1865, pp. 71, 72. ci^K.] CORRELATION OF DEPOSITS. 81 are, in the main, identical, though, so far as investigation has gone, the fauna of the Virginia Eocene is more varied than that of Maryland, and in the presence of Ostrea sellcejormis and other important forms shows a closer relationship with the more southern areas. Whether it is the representative of the Lower or Middle Eocene can not be stated with deflniteness, although it seems probable that portions of each are represented. Continuous deposition under similar circumstances seems to have prevailed, and renders aoy division of the series difiicult. North Garolina. — The fauna of the North Carolina Eocene presents so many differences from that of other areas that it is difficult to cor- relate the strata. The deposits have much less in common with the Virginia region than with South Carolina, when viewed either from a paleontological or structural standpoint. Ostrea sellceformis and Car- dita planieosta occur sparingly together with other forms that are found in the Middle Eocene of Alabama. Too little is known of the fossils and their range to enter much into details, but there is little doubt that the Middle Eocene is here represented, though its lower portions may be absent. There are also points of relationship between the limestone beds in the eastern portions of the State and the White limestone facies farther south. Too little is known of the fauna to pass final judgment. It seems probable, however, that the Upper Eocene is here represented. South Carolina. — The Eocene of South Carolina is represented by portions, at least, of the Lower, Middle, and Upper members. That some of the basal and superior beds are lacking, and that there may have been interruptions in continuous deposition seems iirobable. The irregularly stratified arenaceous beds at the base of the series, classed with the Buhrstone in Tuomey's South Carolina report, are beyond much doubt to be correlated with the Lignitic of Alabama, and are thus Lower Eocene. Although lignitic strata are not wholly lacking, yet the conditions under which the beds were accumulated were very different from those existing in the Gulf region. The seas were open, and sands and clays were chiefly deposited, while lignitic accumulations were form- ing in the Mississippi embayment. The overlying argillaceous deposits are probably Buhrstone, though they may include also, in part or in whole, the Claiborne. They are of Middle Eocene age. Among the species found that occur in the Middle Eocene elsewhere, though not distinctive in sk\lcases,a.re Turritella Mortoni, Garditaplanicosta, Gytherea ovata, Grassatella almformis, Pectunculus stamineus, and Ostrea sellcefor- mis. The " calcareous strata of the Charleston Basin," which include the Santee Beds and the Ashley and Cooper Beds of Tuomey, are to be correlated with the White limestone of Alabama, and are thus upper Eocene, though the evidence for the presence of the upper horizon (Vicksburg) is by no means conclusive. The existence of Zeiiglodon remains in the different members of the calcareous strata (Santee Beds and Ashley and Cooper Beds), together with the character of the mol- lusca, is strong proof of their identity of age with the Jackson gxonp of Alabama and Mississippi. Some of the beds on the left bank of the Bull. 83 6 82 THE EOCENE. l»oi^ «»• Savannah, opposite and below Shell Bluff, have been correlated with the Vicksburg, upon evidence previously stated and have been called the " Shell Bluff group." Georgia. — Although investigated much less fully than in South Caro- lina, the Eocene deposits of Georgia include probably the three divis- ions there represented. The "Buhrs tone" is described as peculiarly typical for Georgia, though as the term is here used it includes part, if not all, of the Lignitic, Buhrstone, and Claiborne of Alabama. A separa- tion of the series into these horizons is as yet impossible from the lack of accessible data. In the southern portion, of the State the Yicksburg group of the White limestone (connecting the Florida and Alabama areas) is doubtless represented, though the evidence is rather of geo- graphical possibility than established fact.* The upper portion of the section exhibited at Shell Bluff, on the Savannah River, was stated by Conrad* to represent a horizon under- lying the " Orbitolite limestone of the Jackson group." Hilgard, in a reply to Conrad,' says the statement that the Orbitoides' occurs in the Jackson group is incorrect, and that the " Shell Bluff' group" of Conrad is probably the equivalent of his " Eed Bluff' group," found at the base of the Vicksburg series and overlying the Jackson. Of the importance of Ostrea georgianator purposes of correlation, Hil- gard claims that it varies greatly from the Jackson oyster, with which Conrad compared it, but may be similar to Ostrea gigantea of the Vicks- burg, which, moreover, is not present in the Eed Bluff group. From this it appears that the evidence for the correlation of the " Shell Bluff group" is insufficient, and beyond the fact that it is included in the White limestoue series and is thus Upper Eocene, it is impossible to go. From the data at hand it is evident that a decided opinion can not be given upon the different horizons represented in Georgia, though it can be stated as probable that the Lower, Middle, and Upper Eocene are present. Florida. — The Eocene of Florida is confined to the upper division, and in its well marked White limestone {)hase, containing Orbitoides Mantclli, Pecten Poulsoni, and Other Vicksburg fossils, is readily correlated with the upper member (Vicksburg) of the White limestone of Alabama and Mississippi. A thin layer of silicifled Miocene limestone is often, found irregularly overlying both the typical Vicksburg and that later phase of it which has been called Nummulitic and which contains species of Foraminifera that are limited to the Florida deposits so far as known. Johnson '' says concerning this latter horizon that " possi- bly these irregular deposits maybe remnants of the Nummulitic lime- stone, which is really a stratum oveylying the Vicksburg rocks, well' X ^ Eecent observationa of Mr. Frank Bums show that the Vickaburg limestoue with Orbitoides crops out 25 feet thick in Pulaski Connty. ' Am. Jour. Sci., 2d sor., vol. 41,1866, p. 96. s Ibid., vol. 42, 1866, pp. 68-70. ' Ibi(f., voL 36, 1888, p. 232. ci^KK.] CORRELATION OF DEPOSITS. 83 seen at the old iron works near Levyville, Levy Connty." As regards its taxonomic importance, "Johnson further states that "there is no sufficient reason as yet observed to regard it as more than an upper layer, similar to such superadded layers seen in Alabama at the Lower Salt Works on the Tombigbee River." Alabama — The extent of the Alabama section, together with the detailed manner iu which it has been studied, has led to its acceptance as the type of the Atlantic and Gulf coast Eocene. The Lignitic has been assigned to the Lower, the Buhrstone and Claiborne to the Middle, and the White limestone, with its further subdivisions into Jackson and Vicksburg, to the Upper division of the series. Such separation is locally warranted on both lithological and paleontological grounds, and may for the present at least serve an important purpose in the comparative study of the Eocene deposits of the Atlantic and Gulf Coast region. So far as the stratigraphy of the Eocene is at present known, the entire series is represented in Alabama. Mississippi. — rThe deposits of Mississippi are readily correlated with those of Alabama, as most of the members persist with similar facies. The lower division, the Lignitic, as previously described, is widely rep- resented. The Buhrstone and Claiborne, defined as siliceous and cal- careous Claiborne by Hilgard, are both present, while the White lime- stone persists in its two divisions, the Jackson and Vicksburg... In general the Lignitic increases in importance from Alabama west- ward, while the members of the Middle Eocene, although represented, form a less marked feature structurally and paleontologioally. The White limestone, on the Other hand, is much more prominently devel- oped, and affords a most varied fauna in both its upper and lower members. A marked feature of dissimilarity with the eastern repre- sentatives of the Upper Eocene, in this respect connecting it with tlie trans-Mississippi type, is the occurrence of lignitic bands throughout the series. Mississippi Umbayment : Tennessee, Kentucky, Illinois, Missouri, and Arliansas. — The Eocene strata of the region to the north of the border Gulf States, forming the Mississippi Embayment, are chiefly to be cor- related with the lower division (Lignitic). The character of the de- posits affords almost the only means of comparison, since few localities have been found where fossils are found. In southern Arkansas, from the occurrence of Claiborne fossils, there is evidence of the presence of the Middle Eocene, but it is doubtful whether the Upper Eocene is any- where represented in this area. So little is yet known of the geolog- ical range of the lignitic beds in the Gulf region that the conclusions drawn from their presence or absence have little value. In the States to the south lignitic strata have been found at every horizon of the Eocene ; yet from the geographical position of the Mississippi Embay- ment, it seems hardly probable that more than the Lower, or at the most Middle, Eocene are represented. 84 THE EOCENE. [buli,.'83. Louisiana. — In a previous chapter the evidence for the existence of the Liguitic in Louisiana was stated. That> evidence was chiefly of a lithological character, and the probability that tlie southern extension of the " Oamden series," described by Hill in Arkansas and shown to be Lower Eocene, would coincide with the deposits of northwestern Louisiana. Hilgard has described the lignitic strata of this area under the nUme of the " Mansfield group," and although in part shown to be Upper Eocene, they are considered by Hill to represent likewise the " Oamden series " (Lignitic). The evidence for the presence of the Middle Eocene is chiefly of a geographical character. On the other hand, the Yicksburg and Jackson have a thoroughly characteristic de- velopment, the White limestone strata abounding in fossils of species identical with those of Mississippi. Intercalated beds of lignitic strata, on the other hand, are more numerous than in the White limestone series to the east of the Mississippi Eiver. Texas. — Heilprin^ and HilP have expressed the opinion that the Ter- tiary of Texas would be found to afford a tolerably complete section of the Eocene when more complete investigations had been made. Heil- prin says that " it may safely be assumed that all, or nearly all, of the divisions ranging from the Eolignitic [Lignitic] to the Grand Gulf, in- clusive, are represented." Concerning the correlation of the Basal or Wills Point Clays, the lower of the two divisions of the Eocene strata established by himself, Penrose says:' "These clays probably represent the Eolignitic of Heilprin's Eocene section, the base of Hilgard's 'Northern lignitic' in his Mississippi section, and the Arkadelphia shales at the base of Hill's ' Camden series,' in Arkansas." He states that the upper portion of " The Timber Beltor SabineEiver beds," the upper division of theEocene as established by that writer, on the Brazos and Colorado River, " show Jackson and Claiborne species with a tendency toward an increase of the Jackson over the Claiborne as we ascend the series." The repre- sentatives of the Vicksburg seem to be quite or nearly lacking, which has been accounted for on the ground that the oscillation that caused deep-sea conditions in the Vicksburg period over the central Gulf States " may have also raised the Texas region into aland area." When more exhaustive study has been made of the Eocene fauna of Texas it may then be possible to institute more accurate correlation with the series established in Alabama and Mississippi. Until that has been done lit- tle more than the statement of the probable presence of representa- tives of the Lower, Middle, and Upper Eocene may be made. 'Contributions to the Tertiary Geology and Paleontology of tlie XTuitetl States, 188t, pp. 37-39, 2U. S. Geol. Snrv., Bnl). 45, 1887, pp. 81-86. •Geol. Surv. Texas, First Ann. Kept, for 1889, pp. 18, 19. t.^AnK.] PEOVISIONAL PROVINCES. 8.5: Tahidar represenlation of the geological range of the Eocene in the Atlantic and Gulf ooasti region. Lower. MidiUe. TTppcr. New Jersey Delaware Marylaud '^ Yirginia Worth Carolina Sou til Caroliua 1 Tlorida. Tonneasee Keutucky 7~. -. ' TUiDois Artaneas PROYISIONAL DIVISION INTO PEOVINOES. As stated in aa earlier portion of this paper, the Atlantic and Gulf Coast Eocene is too imperfectly understood to admit of its direct treat- ment by provinces though certain indications of a paleontological and lithological character render a provisional division possible and neces- sary. , The Gulf region, due to the fuller representation of the Eocene series and the more exhaustive investigations, that have been there recorded, may be considered to afibrd the type development of that horizon, and so the standard with which other Eocene areas may be compared. For tliis reason even a provisional division of the Atlantic and Gulf Coast region into provinces must depend largely upon correlative data, based upon the Gulf series. Wider investigations may show tbat what to-day seem restricted characters whether structural or paleontological are to be largely ex- plained on account of our imperfect knowledge. Connecting links now wanting may unite all parts into a consistent whole, so that the wide faunal differences that now appear may be found much less prominent, even if they do not entirely disappear. Judging from present data four more or less fully defined areas dependent upon structural and paleontological differences may be established in the Atlantic and Gulf Coast region. They are: 1, New Jersey province; 2, Maryland- Virginia province; 3, Carolina-Georgia province; 4, Gulf province. New Jersey province. — The Eocene area of New Jersey forms an insig- nificant portion geographically of the Atlantic and Gulf Coast region. In the character of its deposits or its fossils the Eocene of this locality affords few points of comparison with its more southern representatives. Lithologically there is a marked difference. The "Blue Marl " of which 86 THE EOCENE. Ibull.83. the New Jersey series is largely composed presents an individual type of sedimentation unlike the Eocene strata to the south. This differ- ence, which may be directlj^ traceable to the underlying deposits from which the Eocene has been largely derived is still further shown in the character of the fossils which the beds themselves aflbrd. The more common Eocene types such as Gardita planioosta, Ostrea sellwformis, Ostrea eompressirostra^ Gueullma gigantea, Gytherea Meekii and others so characteristic for the deposits in Maryland and Virginia are lacking, while with the possible exception of Grassatella alta none of the more southern forms appear. The species most common for the New Jersey area are with scarcely an exception confined to that region. The question naturally presents itself in connection with the study of the Eocene deposits of New Jersey, whether the structural and faunal differences are due to differences of contemporaneous origin, upon which alone the claims to separation as a province rests, or whether the horizon of the New Jersey deposits may not be different from that of the strata immediately to the south in Maryland and Virginia, with which comparison has been chiefly made. That the latter may be the case has been by no ineans disproved. The evidence for or against either one of these suppositions is so inconclusive that final decision can not be rendered. However, for lack of opposing data, the New Jersey deposits may be for the present purpose best treated as a pro- visional province. Maryland- Virginia provinoe. — Of much wider geographical extent than the New Jersey region is the Eocene area of Delaware, Maryland, and Virginia, though in its turn much more circumscribed in range than the regions farther south. Although showing greater similarity in the character of its deposits and fossils with the south Atlantic and Gulf Coast Eocene, than the New Jersey province, the Maryland- Vir- ginia province is still sufiQciently distinctive in both to require complete separation as a geological unit. The green-sand marl of which the Eocene deposits of this area are almost exclusively composed, although found elsewhere in the Atlantic and Gulf Coast region is nowhere so extensively developed as in Mary- land and Virginia. It is thoroughly characteristic for the Maryland- Virginia province. The fossils likewise are in the main distinctive and confined to the limits assigned to that province. They are quite unlike the fauna of New Jersey on the one hand and that of the Carolinas on the other. Several forms it is true are comparable with the types of the more southern representatives of the Eocene, espiecially the common bivalves Gardita planicosta and Ostrea seUwformis. A sufficient number, how- ever, are limited in their geographical- range and thus show that the conditions for their existence in Eocene times were such as to confine them to the Marylan d- Virginia. region.^ Similar questions of doubt as ' Future inveBtigations may show this difforencea to be much less marked than they now seem. Fuller comparisons with Bouthern forms may show a greater number of identical Bpecies. CLAEK.] PEOVISIONAL PROVINCES. 87 to the contemporaneity of the Maryland-Virgiuia deposits with the type series established for the Eocene arise as in the New Jersey area, bat for the same reasons the provisional separation of the Maryland- Virginia region as a geological province is made. The Eocene deposits of this area are termed by Darton the Pamunky formation. Carolina- Georgia province. — The Carolina-Georgia province affords a much more complete series of Eocene strata than the northern areas. Possessing more important representatives, however, in the Middle and Upper divisions of the Eocene than the Lower, the possibilities of com- parison with northern areas are narrowly circumscribed. The earlier Eocene presents a very different facies in the Carolinas and Georgia from that in Virginia, Maryland, or New Jersey. The coarse, incon- gruous sands and clays show that the mode of accumulation of the de- posits was very different and, moreover, ill adapted for the preservation of marine organisms, even if many had found there a congenial habitat. The few fossils that occur are mainly different from those in other areas, but the fauna is very imperfectly understood. The arenaceous character of the beds affords some points of similarity with the Lower Eocene in the Gulf States, although the lignitic strata of the latter are wanting. The later Eocene deposits, formed in a sea which almost no muddy sediment reached, are chiefly limestones and marls and pos- sess a fauna that can have little in common with the northern Eocene, though many identical species' with the White limestone horizon of the Gulf States are found. Gulf province. — The Gulf province, extending from Florida to Texas and including the Mississippi embayment, presents certain character- istic features that separate it both lithologically and paleontologically from the Atlantic coast provinces. The wide development of lignitic strata throughout the Gulf province must have required peculiar con- ditions for their accumulation that did not exist along the Atlantic coast. Moreover, these conditions were not confined exclusively to the earlier stages of the Eocene, although there predominqiing, but fre- quently recurred throughout the entire period. We find that even the Jackson and Vicksburg groups are not without their lignitic beds, although in the eastern portion of the region they are much less fre- quent. Tiie Lower Eocene of the Gulf province attains great prominence, and in the region of the Mississippi embayment reaches its most marked development. In its geographical extent it is the leading member of the Eocene. It becomes much less lignitic in the eastern portion of the region than in the central and western ; its faunal characteristics are there more marine and the beds more calcareous. The Middle Eocene in its two divisions, the Buhrstone and Claiborne, presents a characteristic series of deposits that acquire their most marked individuality in the State of Alabama, where a varied fauna 1 The fact tbat most of tlie Carolina-Georgia forms occar as casts renders a comparison difficult. 88 THE EOCENE. [bull. 83. characterizes tlie upper of the two horizons. The Biihrstone largely loses its alumiuous character toward the Georgia .line and becomes more fossiliferous. • The Claiborne, away from the plnce of its typical development at Claiborne, Alabama, rapidly changes. The various horizons there represented disappear in part, or changes coming in at short distances give the beds quite a different appearance. The Upper Eocene, with its widely developed White limestone beds, affords a sharp contrast to the other members of the Eocene series. In the western portion of the area the White limestone, so typically de- velopeii in Alabama, is frequently interstratifled with beds of arena- ceous deposits containing bauds of lignite. The fauna of the various horizons of the Eocene in the Gulf States is vastly richer than on the Atlantic Coast, and affords many species that do not exist in the latter region. The similarities to the Caro- lina-Georgia province, however, are much greater than to the more northern areas. COMPARISON WIXH EUEOPEAN DEPOSITS. The attempts of geologists to correlate American Eocene strata with European have decreased in about the ratio that real knowledge of the deposits has increased. The earlier geologists thought nothing of cor- relating individual beds with the minuter divisions of European strata. At first lithological similarities were thought sufficient, but even after the fossils themselves were considered, generic identity still afforded a basis for correlation of the most detailed character. Of late there has been more of a tendency to study American formations with reference to their own individuality rather than that of some fancied resemblance to the deposits of other lands. When our knowledge of the American Eocene has not progressed to such a point as to admit of a correlation of the strata of contiguous regions, how is it to be expected that wider com- parisons can be successfully made? Some simifarities of a general character in deposits and fossils occur, however, and it is these which will be briefly examined. When we take into consideration the deposits forming along existing coast lines, we find how little value for purposes of correlation the similarity or dissim- ilarity of sediments can possibly have. Both in America and Europe we find a great diversity in the character of the strata. Brackish and marine facies appear, tlje latter with both littoral and infralittoral de- posits. Moreover, the fresh-water sediments occurringin the geograph- ically more circumscribed "basins" of Europe are lacking in the Atlantic and Gulf Coast region of America. Further, when we observe that the geographical range of shallow- water marine species is limited, we can hardly expect that many identical forms will be fottiid'cdmmon to the American and European Eocene. A few species, however, among which the Gardita planicosta is the most important, are widely repre- OLAHK.] EtJROPEAN EQUIVALENTS. 89 sented in the Eocenestrata of both contiiieuts. Heilprin* has made a comparative study of Amei-icau and European Eocene species, and maintains the identity or close relationship of many forms. Conrad,^ Morton,^ Lea,"* and Meyer" have made similar comparisons, a review of whose conclnsious are presented in the article by fleilprin. Others, on the other hand, do not consider the existence of identical species in the Eocene of the two continents probable, with the possible exception of Gardita planicosta and one or two other less usual forms. The general character of the faunas of the two continents is, however, suflSciently similar to render it probable that the Eocene series of Eu- rope is represented in the American Eocene series, which latter may likewise include the Oligocene of the Old World, though it does not seem to the writer that the evidence adduced is as yet sufficient to prove either its presence or absence. As stated in the general intro- duction to this report, the term Eocene, as we have employed it, may or may not include both the Kocene and Oligocene as those terms are used in Europe. 'Contributions to tlie Tertiary G-eoIogy and Paleontology of the United States, pp. 83-101. In this article Heilprin discusses briefly the points of similarity iu the species that follow : America. Europe. Oatrea compressirostra, Say - (?) 0. bellovacina, Lara. divaxicata, Lea (O. falciformis, Conr.) O. flahellula, Lam. Cardita rotunda, Lea (?1 C. imbrieata. planicosta, Lam C. plauicosta, Lam. Cardium NicoUeti, Conr C. semigranulatam, Sow. Corbis lirata, Conr G. lamellosa. Lara. Pectunculnsiaoneus,Conr c (?) P. proximus, Wood. ( (?) P. polymorphus, Desia. Limopsia aviculoides, Conr. (Pectunculus obliquus, Lea) ('■') Pectunculus (Limopsis) minutus, Pbilippi. Trjgonoccelia cuneus, Conr. (Nuoula carinifera, Lea) (?) Nucula (Trigonoccelia) deltoidea, Lam. Corbiila ouiscaa, Conr. (C. ilurchisonii, Lea) U. rugosa, Lam. Trocbita trochlformis. Lea T. (Calyptra?a) trocbiformis, Lara. Tornatellabella, Conr Auricula (Aciteon) Simula ta, Sow. Solarium oriiatnm, Lea S. caualiculatura, Lam. Niao umbilicata, Lea N". angiiaU, Desb. Pyrnla tricoatata, Beab ' P. tricostata, Deeb. , penita, Conr. (P. trioarinata, Conr. ; P. cancellata. Lea; P.elegantissima, Lea) P.nexilis, Lam. Cyprseclia feneslralis, Conr Cyprsea olegans, Defr. Oliva bombylia, Conr. (0. coaatricta, Lea) (?) 0. olavula, Lam. Volata limopsis, Conr (?) V. orenulata, Lara . Oancellariatortiplica, Conr. C. UJiiocinum) evulsa, Brand. Sigaretns canaliculatua, Sow S.canaliculatua, Sow. Tarbinella (Carlcella) Baudoni.Desb Voluta Bauduui, Doab. Fnaus pacbyleurua, Conr (?) F. claveJlatua, Lam. Pleurotoma denticula, Bast P. denticula, Bast. acuminata, Sow P. acuminata, Sow. Terebra constricta, Lea Cerithium triline:itam, Pbil. Melania claibomenais, Heilp (?) M. mixta, Desb. ^Fossil Sbells of the Tertiary Torraations of Nortb America, 1832, p. 34. 'Synopsis of the Organic Remains of the Cretaceous Group of the Upited States, 1834. *Contribations to Geology, 1833, p. 19, ephiladelpbia Acad. Nat. Sci., Proc.,vol. 36, 1884, pp. 104-112. 90 THE EOCENE. lBnu»83. A more detailed correlation of the several divisions of the Eocene of America seems to the writer impracticable. The Claiborne sauds have commonly been considered the equivalent of the "Calcaire Gros- sier" of the Paris Basin and the Jackson of the " Barton Clay" of Eng- land, while the Bulirstone and Lignitic have been variously assigned to the lower horizons of the Eocene of Europe. It is unnecessary here to refer in detail to the extensive literature that lias dealt with the correlation of the Vicksburg beds, which have been by many held to represent the Oligocene. As stated above, the data are not sufficient to solve the question for or against their equivalence. In short, until we comprehend more fully the complex development of the American Eocene, wider comparisons must be made with the greatest reserve. APPENDIX. THE BRANDON FORMATION. Under the name of The Brandon formation the lignitic beds of Ver- mont, Pennsylvania, and Georgia are included, deposits whose taxon- omy has not been yet definitely determined, but which from certain indications may be provisionally referred to the Eocene. It is by no means certain that future observations will establish the contempora- neous formation of the various deposits here described, but with the very insufBcient data at hand the strata appear at present to be best interpreted by referring them to a common horizon. Prof. Edward Hitchcock was the first to call attention to the strat- igraphical importance of the lignitic beds of the eastern portion of the United States. In an article' in the American Journal of Science for 1853 he describes the "Brown Coal deposit" of Brandon, Vermont, and employs the data thus afforded "to determine the geological age of the principal hematite ore beds of the United States." The associa- tion of the lignitic strata with beds of iron ore, kaolin, and clay is stated, and from the occurrence of fossil fruit similar to forms de- scribed from tjie "newer Tertiary" strata of Europe the entire series is assigned to that horizon. On this and other grounds to be referred to later, he states t^at " the Brandon deposit is the type of a Tertiary formation hitherto unrecognized as such, extending from Canada to Alabama." The same conclusion is stated in a later publication,* in which he affirms that "no geologist has doubted that these deposits were all contemporaneous, but their true age has been a mystery." Hodge,' who had examined the iron ore deposits of western New England, was of the opinion that " Hitchcock's Tertiary theory of these deposits has been too hastily adopted." Whitney* nevertheless ^ « ' Am. Jour. Sci., 2d set., vol. 15, 1853, pp. 95-lM. ' GeoloKj- of the Globe, 1853, p. 105. • Am. E. E, Jour. Xo. VH, 1853. ♦Metallic Wcaltb, IS.jl, pp. 460,461. CLAKK.] BRANDON FORMATION. 91 accepted the conclusious of Hitchcock and referred tbe brown hema- tites of western Massachusetts to the Tertiary. Tbe possibility of a wide correlation of the brown hematite deposits upon the dara afforded by the Brandon lignites was strongly denied by Prof. J. P. Lesley,' who dissented also from the opinion expressed by Hitchcocli as to the contemporaneous formation of the deposits thus linked together. He says " there is no sufficient evidence upon the ground at Brandon, in Vermont, that' brown hematite, the lignite, and the kaolin are related to each other in any such fixed way as to insure the fact that they are, per se, and not as a mere local and exceptiomal deposit, contemporaneous." The author considers in this paper that the local occurrence of lignite at Brandon is to be accounted for by the accumulation of vegetable debris in a "sink" formed iu the lime- stone. Prof. Hitchcock ^ presents a more exhaustive discussion of the ques- tion in his report on the geology of Vermont, in which he reaffirms his previous claim as to the contemporaneity of the Brandon deposits and correlates the iron ore beds extending from Canada to Alabama. He calls attention to the occurrence of these beds in limestone (Silurian) valleys. In an article in the American Journal of Science for 1861 Prof. Les- quereux ' describes the fossil fruit of Brandon and compares certain of the forms there found with, species from the Lignitic of the southwest. In a paper in the proceedings of the American Philosophical Society for 1865 Prof. Lesley * announces the discovery of a deposit of lignite uear Ohambersburg, Franklin County, Pennsylvania, that is closely analogous to the Brandon bed. He further states that of the many localities mentioned by Hitchcock as aftbrding deposits of contem- poraneous age this alone admits of comparison. The author quotes Hitchcock at length to show that he has included other deposits in describing the Brandon lignite formation. He asserts that " the lignite and iron ore are neither of the same age, nor, strictly speaking, pos- sessed of any structural attribute common to both." The iron ore beds are considered Silurian while the lignite deposit is assigned to the late Tertiary. In 1878 Prof. Prime ^ announced the discovery of lignite at Ironton, Lehigh County, Pennsylvania, though he referred it and the associated iron ore to the Glacial epoch. Tbe discovery of lignite in Montgomery County, Pennsylvania, was re- ported by Lewis ^ to tbe Academy of Natural Sciences of Philadelphia at its meeting on September 22, 1879. A month later a succinct review of the opinions that bad hitherto been current in regard to the age and 'Iron Mshnfactnrer's Guide, 1859, pp. 514, 518, 539. = Geology of Vermont, vol. 1, 1861, pp. 226-240. ^ 'Am. Jonr. Sci., 2a scr., vol. 32, 1801, pp 355-363. «Proo. Am. Phil. Soc, vol. 9, 1865, pp. 463-480. 'EepoitDD.,2d Geol. Survey of Penns.vlvaTiia, 1878, p. 78. « Philadelpliia Acad. Nat. Sci., Proc, vol. 32, 1880, pp. 281-291. 92 THE EOCENE. |buli.,83. correlative value of the lignite beds was presented by tlie same writer who gave a detailed description of the Montgomery County de- posits. As a postscript to the published paper a letter is printed from Prof. N. A. Bibikov, of Augusta, Georgia, announcing th.e discovery of lignite in Richmond County of that State. Concerning the association of the iron ore beds with the lignitic strata as claimed by Hitchcock and denied by Lesley, Lewis says that the iron ores of this region probably belong to four different geological ages, and he classes them as (1) Gneissic ore. (2) Primal ore. (3) Ter- tiary ore. (4) Drift ore. He thus separates the iron ore associated with "the deposits of lignite, plastic clay, kaolin, fire-sand, etc.," from that which has been heretofore confounded eitlier with the primal ore or with the drift ore. " The discovery of lignite below it [the tertiary ore]," he says "proves its restratiflcation in a later age [Tertiary] than the decomposed primal ore that is found in place." The term Brandon period is proposed by Lewis to designate the age of the lignite beds. He says: Since in the present state of our knowledge it is obviously unsafe to make the age of tUeso lignite deposits contemporaneous with any exact geological epocb, and as there is a possibility of their belonging to some period not recognized elsewhere. Nevertheless, he suggests that they may be most closely correlated with the Oligocene of European geologists. Vennont. — Hitchcock/ in the American Journal of Science and later in the geology of Vermont,'' describes the deposits of the type local- ity Brandon, and also mentions other points in the State where sim- ilar deposits are found. At Brandon he states that tlie beds, wlii<;h dip at a high angle to the northwest, rest upon "yellowish limestone," are associated with clay, kaolin, and iron ore, and are overlaid by di iff. The lignitic strata were found to be 20 feet in thickness at the points where they were penetrated. Lesquereux^ describes in the American Journal of Science the fossil fruits found at Brandon, and compares certain of the forms with those afforded by the Lignitic of the Southwest. The following species are referred to by Lesquereux : Carpolithes brandouiana Les. Aristolochia Oen'ingensis Heer. fissilis Les. curtata Les. irregularis Les. obscura Les. Grayaua Les. Sapindus americanus Les. bursseformis Les. Illioium lignitum Les. venosus (?) Stern. Driipa rhabdosperma (?) Les. Carya verrucosa Les. Leganiinosites pisiformis (?) Heer. vermontana Les. Ny.ssa complanata Les. Fagus Hitchcoekii Les. microcarpa Les. Apeibopsis Heerii Les. liievigata Les. Gaudini Les. » Am. OTour. Sci., 2d.8er., vol. 15, 1853, pp. 99- M4. ' Geology of Venoont, vol. 1, 1801, pp. 'J2G-2iO. ' Am. Jour. Sci., 2a ser., vol. 32, 1801, pp. 355-363. ci^KK,] BEANDON FOEMATION. 93 Concerning the other localities in the State Hitchcock* says: Wherever we have fouud brown hematite and manganese, or beds of ochre, or pipe clay, white, yellow, or red, in connection with beds of coarse sand or gravel, all lying beneath the drift and resting on the rocks beneath, we have regarded the deposit as an equivalent of that at Brandon just described, even though not more than one or two of the substances named be present. Proceeding upon these grounds he correlates the deposits of 26 local- ities lying chiefly along the western slope of the Green Mountains. - As stated above, Lesley cast doubt upon the analogous character of these different beds. The statements of Lewis afford a partial expla- nation of the phenomena, but much more careful investigation is needed at the type localiiy, Brandon, before the relations of the beds can be fully comprehended. Pennsylvania. — Several localities have been reported in Pennsylvania where lignite deposits are found under much the same conditions as in Vermont. Lewis ^ described in considerable detail a section which he obtained at Marble Hall, Montgomery County, in an excavation sunk about 40 feet into the unconsolidated strata. It is as follows : Feet. " Top dirt" yellow, impure 10 Soft white decomposed hydromica slate or impure "kaolin," containing occa- sional broken seams of sharp quartzite, but no pebbles 13^ Coarse white sand and rounded pebbles; apparently a decomposed sandstone 2 Tough mottled red clay i Blue plastic clay / 7 Lignite in a very tough dark clay 3 Coarse yellow sand, with fragments of stony iron ore and with pebbles 2 The same locality had been earlier referred to by Lesley,^ but as the lignite was supposed to be Triassic, its discovery was considered unim- portant. Later, Lesley * reported lignite at Pond Bank, near Cham- bersburg, Franklin County, where it occurs in two beds, the lower 18 feet, the upper 4 feet in thickness. They are separated from one an- other by a bed of sand, while clay and sand are found above the upper layer. Prime * mentioned in 1878 another locality, atlronton, Lehigh County, where the lignite occurs associated with white clay. The parallelism of the strata described by Lesley and Prime to those in Montgomery County is given on the authority of Lewis. Both Lesley and Lewis as- sert the analogous nature of the Pennsylvania and Vermont deposits. ' Geology of Vermopt, vol. 1, 1861, p. 234. 2 Philadelphia Acad. Nat. Soi., Proc, vol. 32, 1880, pp. 282-291. - Am. Assoc. Adv. S»i., voy9, 1880, pp. 427, 428. ■ ^Philadelphia Acad. Nat. Sci., Proc, vol. 13, 1861, p. 77. ' Am. Phil. Soc, Proc, vol. 9, 1865, pp. 463-482. « Eeport DD, 2d GeoL Surv. of Penn., 1878. p. 76, 94 THE EOCEl^E. [buI'I-- 83. Georgia. — A locality in Georgia near Berzelia, Eicbmond County, 16 miles from Augusta, is described by Lewis ^ from notes by Prof. N. A. Bibikov, of Augusta. He says concerning the locality : It is described as lying back of tbe outcrops of gneiss and limestone, and is appa- rently in a very similar geological position to the Pennsylvania locality. Iron ore, plastic clay, kaolin, and decomposed sandstone occur with the lignite. » * » The fossils appear to be fragments of trees, grasses, and other land plants, none of which, howpver, were sufficiently perfect to be determined. The section is given below in detail : Feet. Mottled clay 4 Decomposed sandstone, with thin layers of clay and nodules of pyrite at base. .. 24 Lignite 2 Shalo and clay 1 Lignite : 3 Shale and clay 2 Lignite — * 1 Shale and clay. .n 3 Lignite , -.s-r-- 5 Light-colored shale with fossil plants 6 Dark-colored (bituminous) shale „...! .1 1 White clay with streaks of rose color, etc 8 Sandy clay ..:... 1 Ferruginous coarse sand, with riodnlesof clay-ironstone, clay and quartz pebbles. 9 Light-colored shale . I. 4 Yellowish sand , 2 Sandy clay 8 White, very fine micaceous sand, with clay 11 Lewis, following in great measure the opinion of Hitchcock, says that the localities previously described in Vermont, Pennsylvania, and Georgia " indicate the existence of a great inland fresh- water Tertiary formation in eastern, America during the Brandon period) once 60 miles broad and nearly 1,000 miles long." As stated in, the introduction to this chapter, we have not as yet sufficient evidence, to warrant such broad generalizations. Indeed, the few facts accessible are hardly indications of the conclusions cited. It seems more probable that the deposits were accumulated in a series of detached bogs and swamps that had been occasioned by depression parallel to, the existing coast line. The absence of fresh-water shells or remains of other forms of life , than terrestrial vegetation points to circumscribed areas of depositioji., 'Pbiladelpljja Acad, Nat. Sci., Proc, toI. 32, 1880, ^p. 289-29;. PACIFIC COAST REGION. PRELIMINARY REMARKS. The geology of the Pacific coast presents mauy unsolved problems. By no means the least among them is the interpretation of the Eocene. By many eminent geologists the very existence of Eocene strata on the Pacific border has been doubted, while others have included much more of the Coast Eauge series withiu its limits than is here admitted. It will thus be seen that the wide difference of opinion which prevails among those who have written upon the geology of the Pacific coast must occasion great dilBculty when an attempt is made to harmonize their statements. Meager though our knowledge is, certain characteristic features pre- sent themselves which render necessary the separation of the Pacific coast Eocene into two well defined divisions or provinces. The strata of the two divisions, together with their fossil contents, show the diverse character of the conditions attending their deposition. In the one case, an open sea with marine sediments and fauna prevailed; in the other, an estuary where the deposits and life were of brackish-water oiigiu. Stratigraphically the relations of these two divisions to one another are not known, and as the conditions attending the accumulation of the deposits were so different the fossils are in no case identical. The marine deposit has been found in isolated regions from southern Cali- fornia to Washington, and has been named the Tejon group by Prof. J. D. Whitney' from its type locality, Fort Tejon, California. The brackish-water deposit has only been recognized in northern Washing- ton, where it occurs in two distinct areas on the eastern and western flanks of the Cascade Mountains. It has been called the Puget group by Dr. C. A. White. 2 The correlation of the Eocene of the Pacific coast with that of the Atlantic border is rendered difficult, due to the marked difference in the specific characteristics of the fauna as a whole, though 'sufficient similarity exists in generic and family types to admit of broad com- parison. In the succeeding pages the history, stratigraphy, and corre- lation of the Pacific coast Eocene will be considered. ' Geologioal Sarvey of California, Pareontology, vol. 2, 1?6D, p. 8. •Am. Jour. Sei., 34 ger., Tol. 36, 1888, p. 443 ; U. §. Qao}. Surr., Ball. 51, 1889, p. 40. 95 96 THE EOCENE. (bull. 83. HISTORICAL SKETCH. The earliest investigations of the later geological formations of the Pacific coast were conducted by the Wilkes exploring expedition under Frof. James D. Dana,^ in the year 1846, when large collections of Ter- tiary fossils were made near Astoria. Oregon. The fossils were de- scribed and referred by Conrad to the Miocene, although later considered by the same authority to be Eocene.^ , In an article in the American Journal of Science for 1848, Conrad' describes 14 new species from the same locality, while Shumard,^ in the Transactions of the Academy of Science of St. Louis, later adds a few more. An important contribution to the Eocene of California was made by Conrad^ in 1855, in the Pacific Eailroad Eeports. He describes a group of fossils he considers to be Eocene, which Blake had discovered in a bowlder at the mouth of the Canada de las Uvas, in southern California. The succeeding year Trask" read before the California Academy of Natural Sciences a paper entitled a "Description of a new species of Ammonite and Baculite from the Tertiary Eocks of Chico Creek," in which he expresses views that have especial interest on account of the opinions subsequently held as to the geological range of those forms in the Coast Eange series. The geological survey of California, conducted by Prof. J. D. Whit- ney, published, in 1864, Paleontology, vol. 1, in which the Cretaceous fossils are described by W. M. Gabb.'' In this work Gabb divides the Cretaceous into Divisions A and B, the latter (B) including the fauna j)reviously referred by Conrad to the Eocene. He also^nentions the range of species from Division A into Division B. A review of this work was published, by Co\irad^ in the American Journal of Conchology in which he states that "Mr. Gabb has in eluded the rock of Canada de las Uvas, which contains Venericardia X>lunicosta and Aturia zic-zac, in the Cretaceous series, but he has failed to show one Cretaceous fossil from that rock [B]." In regard to the divisions of the Cretaceous strata (A and B), proposed by Gabb, Con- rad says further, "The former [A] is, doubtless Cretaceous, and the latter [B], I am sure, will prove to be Older Eocene." Gabb' replies to Conrad's criticism in a paper published in the suc- ceeding volume of the same journal, in which he denies that "he has failed to show one Cretaceous fossil froui that rock [B]." He gives a 1 Wilkes Exploring Expedition, vol. 10, 1849, pp. 611-678. » Am. Jonr. Coucli., vol. ], 1866, p. 160. 5 Am. Jour. Sci., 2d ser., vol. 6, 1848, pp. 432-433. ■■ St. Lonls Acad. Sci., Trans., vol. 1, 1858, pp. 120-126. ' Preliminary Eepoit Pacific Eailroad Smvejs, Paleontology, 8vo, 1855, ; Pacific Kailroad Keports, 4to, vol. 5, 1666, pp. 317-829. » California Acad. Nat. Scl., Proc, vol. 1 , 1850, pp. 92-93. ' GeoL Survey California, PaloontoloRy, vol. 1, 1064, pp. 65-230, » Am. Jour. Conch., vol. 1, 1806, pp. 362-305, sibid., vol. 2, 1866, pj). 87-98. CLAKK.] HISTORICAL SKETCH PACIFIC COAST. 97 list of 14 species that are common to the two divisions (A and B), and subsequently proceeds to show the Cretaceous character of some 20 other forms. A few pages later Conrad ^ defends his earlier position in regard to the age of the strata in question and states that Gabb has only suc- ceeded in referring "one exclusively Cretaceous genus to that divis- ion." As regards the presence of similar faunal characters in the two divisions, he suggests in a foot note the explanation that "the Lower Eocene beds of Jamaica contain masses of Cretaceous limfstone, and it may be that the Galiforuia Lower Eocene strata contain similar masses." Conrad considers the several forms which are held by Gabb to prove the Cretaceous age of the deposits and shows many of them to be Tertiary in character. The ye^r following the appearance of Paleontology, vol. 1, of the Geological Survey of California, Professor Whitney published Geol- ogy, vpl. 1. lu this work the characteristics of the Upper Cretaceous (Division B — Eocene) are described in detail, and althougli depending upon the conclusions of Gabb for the taxonomy of the deposits, he presents an important r6sum6 of the strati graphical features of the beds. In 1866 there appeared in the Smithsonian Miscellaneous Collections a " Check list of the Invertebrate Fossils of North America — Eocene and Oligocene — by T. A. Conrad." The species placed by Gabb in divison B of the Cretaceous together with five common to A and B are included in the Eocene. At a meeting of the California Academy of Natural Sciences in November, 1866, a paper by Gabb^ "On the Subdivisions of the Cre- taceous FormatioQ in California " was read, in which omissions in Con- rad's Check List from his series of fossils from division B are men- tioned. In this article the author restates Ms previous position in greater detail than before and gives a table showing the geological range of the different species. He enumerates sixteen forms common to the upper and lower divisions. Two articles appeared in the American Journal of Science for 18C7, by Gabb^ and Conrad*. In the first, Gabb gives the substance of his paper before the California Academy of Natural Sciences ; while in the second, Conrad defends himself against the charges preferred by Gabb in his latest publications, and at the same time claims, as in earlier papers, that " any evidence so far is wanting to prove the strata in question Cretaceous, and as the group of fossils is so decidedly Tertiary in their forms and some species identical, I am forced to the conclusion of their Eocene origin." 'Am. Jour. Conch., vol. 2, 1866, pp. 97-100. s California Acad. Nat. Sci., Proc, vol. 3, 1867, pp. 301-308. "Am. Joar. Sci., M ser., vol. 44, 1867, pp. 226-229. «lbid., pp. 376,377, Bull. S3 7 98 THE EOCENE. (bull. 83. In the preface to Paleontology, volume 2 of the Geological Survey of California, Professor Whitney proposes the name Tejon Group for Division B of Gabb's Cretaceous, from its characteristic occurrence in the vicinity of Port Tejon.' Other important localities are referred to. Two short articles by J. G. Cooper on the Eocene of California ap- peared in the Proceedings of the California Academy of Science^ for 1874, in which the opinions expressed by Gabb and Conrad are com- mented on. A very important contribution to the geology of the Pacific coast was published in the Eeport of the Chief of Engineers for 1876 by Prof. Jules Marcou,' being part of the Annual Eeport of the Geographical Surveys West of the Oue Hundredth Meridian. The writer defends tlie position taken by Conrad, but goes further in that he includes in the Eocene the Chico group, upon which the Tejon group conformably rests. In regard to the latter he says : I was not -able to find a single Cretaceous fossil, nor even any true Cretaceous generic forms in the entire formation ; and I am altogether of the opinion expressed by Mr. Conrad, many years before Mr. Gabb, in volume 5 of Pacific Kailroad Explora- tions, pages 318-320 et. seq., who, judging from certain fossils found In an isolated block at the entrance of the CaSada de la XJvas, has very judiciously referred these rocks to the Eocene-Tertiary formation. He further considers them upper Eocene. Prof. Dana,* in the revised edition of his Manual of Geology like- wise asserts the Tertiary age of the Tejon series and refers the same to the Lignitic or Lower Eocene. Heilprin,^ in 1882, in a communication to the Academy of Ifatural Sciences of Philadelphia, " On the occurrence of Ammonites in deposits of Tertiary age, " states the results of an investigation of the original types described by Gabb in the reports of the Geological Survey of Cal- ifornia. He says : That, with the exception of one solitary fragment of an ammoDlte, there was, to his knowledge, not a single distinctively Cretaceous type of organism to be found in all the rock fragments, but, on the contrary, several genera, distinctively Tertiary, and not known anywhere to have appeared before that period. In the same volume of the Proceedings of the Academy of Katural Sciences of Philadelphia, Prof. J. S. Newberry^ replies to Prof. Heil- prin. He considers the evidence brought forward for the Tertiary age of the Tejon group not sufftcient to overthrow the conclusions of Gabb and Whitney, who had the advantages of exhaustive study in the field. Dr. Newberry adds, "but there are many species common to the Tejon and Chico groups, and where one goes the other must follow." ' Geol. Sarv. California, Paleontology, vol 2, 1869, p. xUL ' California A.cad. Sol. Proc, vol. 5, 1874, pp. 419-421, 422. « Eeport of the Chief of Engineers for 1876, Part ni, pp. 378-392, •Manual of G-eology, revised edition, 1880, pp. 491, 508. •Philadelphia Aoad. Nat. Sci., Proc, vol. 34, 1882, p. 94, 'Ibid., pp. 194, 105, ra^KK-l HISTOEICAL SKETCH — PACIFIC. 99 In alater article " On the Age of the Tejon Eocks of California and the occurrence of Ammonitic Remains in Tertiary Deposits " Heilprin^ re- views very critically the conclusions of Gabb and shows many errors in the statements of that writer. In conclusion he says : We believe it has been satisfactorily shown from what has preceded, that the rooks of the Tejon group (Cretaceous, Div. B.,of the California Survey), despite their com- prising in their contained faunas a limited number of forms from the subjacent (Cre- taceous) deposits, and a few undoubted representatives of the Ammonitidss are of ' Tertiary (Eocene) age, and for the following reasons : I. The large percentage (about 80, or possibly considerably more) of specific forms that are peculiar to the group, or, at least are not found in the older deposits ; II. The large proportion of generic forms (33 out of 77) that are not represented in the underlying or older strata ; III. The presence of twenty-two more or less distinctively Tertiary genera : Ancil- laria, Bulla, Bullsea (Megistomata), Bullia (s. g. Molopophorns), Conus, Crepidula, Cassidaria, Cancellaria, Cyprsea, Ficus (Ficopsis) . Gradus, Mitra, Massa, Niso, Olivella, (or Oliva), Pseudoliva, Rimella, Sigaretus (or Natioina), Terebra, Triton, Trochita, and Typhis. IV. The marked absence (with the exception of about a half a dozen fragments or ^specimens of Ammonitidse) of distinctively Cretaceous organic types. V. The identity or close analogy existing between several of the specific forms and their representatives from other well determined Tertiary (Eocene) deposits. In an article entitled "Note sur la G6ologie de la Oalifornie"^ Prof. Jules Marcou restates his grounds for including the entire Ohico-Tejon series in the Eocene. In "Notes on the Mesozoic and Cenozoic Paleontology of California" Dr. C. A. White' reviews the paleontological evidence presented in the Chico-Tejon series and says : I think the evidence which has been adduced to show the Eocene age of the upper or Tejon portion of the Chico-Tejon series is as conclusive as any evidence of that kind can be. Now, if we apply the paleontological standard for indicating the age of formatlon% which is generally accepted by geologists, we necessarily refer the fossils of the lower or Chico portion of that series to the Cretaceous. The more detailed reasons for these conclusions will be examined in the next chapter. In a later bulletin the same writer* considers " The Occurrence of Gardita planicosta Lamarck in western Oregon." He cites its discovery at Albany, Willamette Valley, Oregon, in a well-digging. In " Notes on the Stratigraphy of California " Dr. Becker^ mentions the conformity that is found between all the beds from the Chico to the Miocene. In "A Report of the Coal Fields of Washington Territory" Mr. Bailey Willis* describes deposits in the vicinity of Puget Sound, on the ' Philadelphia Acad. Nat. Sci., Proc, vol. 34, 1882, pp, 196-214. Keprinted in " Contributions to the TenUry Geology and Paleontology of the United States," 1884, pp. 102-117. 'Bulletin de la Soci§t6 gMogique do France, 3° seri6, tome 11, 1883, pp, 415, 41S. ' U. S. Geol. Surr., Bull. 15, 1885, p. 16. « U. S. Geol. Surv., Bull. 18, 1885, pp. 7-9. » TJ. S. Geol. Surv. , Ball. 19, 1885, pp. 12, 18, 17. * Xenth Census of the TTuited States, toL 15, Mineral In^stries, 1885, pji, 769-77), I 100 THE EOCENE. [bull. 83. Green Eiver and at Wilkeson, and also on the east slope of the Cascade Mountains, that he considers to be representatives of the Laramie forma- tion. The evidence, chiefly derived from the fossil flora, is given on the authority of Prof. J. S. Newberry. In the American Journal of Science for 1888 Dr. 0. A. White' char- acterizes the Puget group and indicates its relations to the Laramie formation on the one hand and the Ohico-Tejon series on the other. The estuarine character of the fauna is commented on. The discovery of marine Eocene fossils on the Dwamish River is also adverted to. In a later publication'* " On Invertebrate Fossils from the Pacific Coast" Dr. White describes the Puget group in greater detail, and gives new localities in Oregon and Washington where the Chico-Tejon series is represented. From this brief outline of the literature upon the Pacific coast Eocene it will be observed that, except at a very few isolated points the depos- its have not been examined, and that even many of those who have written upon the subject have had little opportunity for close observa- tion of the strata. As might be expected, our knowledge of the Paciflp Coast region is but fragmentary, and much detailed work remains to be done before the many diverse opinions expressed will be fully harmon- ized. STEATIGRAPHICAX, AND PALBONTOLOGICAIi CHABACTEKISTIOS. We have but few facts to guide us as to the distribution of the Eocene upon the Pacific Coast. That it extends more or less widely along the east flank of the Coast Eange is known from several isolated exposures that have been examined in central and southern California, and that it is not absent even farther north is proved by the discovery of fossils in Oregon and Washington. To what extent the strata of these sep- arate districts may be continuous it is difficult to judge on account of the lack of data upon which to base conclusions. As stated in the introduction, two clearly defined divisions have been recognized in the Eocene, the one marine, the other brackish water in character. The former, called the Tejon group, is found represented in California, Oregon, and Washington ; the latter, the Puget group, in Washington alone. Strati graphically and paleontologically, no direct ground for comparison is afforded, but that the two groups are proba. ably wholly or in part synchronous will be later shown. THE TEJON GROUP. The Tejon group, first so called by Prof. Whitney, is typically developed in the vicinity of Fort Tejon, Kern County, California. From this point the strata extend northward and southward along the eastern flank > Am. Jour. Soi., 8d ser., vol. 36, 1888, pp. 443-450. >tr. S. Geol. Surv., BaU. 51, 1889, pp. 11-32, 49-63. ciAKK.] TEJON GROUP. 101 of the Coast Range Mountains. They form a narrow belt, frequently interrupted as the result of denudation and volcanic outflows, though much of the irregularity is held to be " due to organic irregularity of the coast lines of the sea in which these strata were deposited."^ To the north of Fort Tejon the strata are prominently developed near New Idria, where they have been investigated by Dr. White.* In Contra Costa County a continuous belt extends from near Marshes to Martinez, while to the north of the Central Pacific Eailroad the Tejon group is not known to appear again within the State of California.' In Oregon it has been found at Albany, in the Willamette Valley, and in the vicinity of Coos Bay, Cape Arago. Certain strata near Astoria are doubtfully referred by Dr. White^ to the same horizon, the presence of which later investigations by Dr. W. H. Dall have fully established. Strata with marine "fossils, many of them identical with those of the Tejon group of California, have been found on the Dwamish River, fh Washington, and have been considered to represent that formation in the extreme north. It will thus be seen that the marine Eocene strata have been estab- lished at many localities along the Pacific coast, and do not form an un- important member in the Coast Range series. The deposits are chiefly conglomerates, sandstones, and shales, in which beds of lignite are not infrequently intercalated, and which less often contain bands of cal- careous rock. The strata of the Tejon group conformably overlie the next older or Chico group,^ and are in turn conformably overlain by the Miocene, a relationship which was first recognized by the members of the California Geological Survey and since substantiated by White and Becker. The strata of the Tejon group in the vicinity of Fort Tejon, at the entrance to the Canadas de las TJvas and de los Alisos, consist chiefly of sandstones and conglomerates. The conglomerates are very coarse, containing many bowlders from 3 to 6 inches in diameter of granite and metamorphic rocks. » » * Portiims of the sandstones are very fossiliferons and the shells in beautiful preservation. • * » The strata are very much disturbed, both dip and strike being very variable, the former varying from northwest and southeast to northeast and southwest, while the dip is sometimes to the north and again to the south and generally at a high angle.* It was from this locality that Conrad received the fossils described in volume 5 of the Pacific Eailroad reports, and from whence Gabb also obtained many of the forms referred by4iim to Division B of the Cretaceous, in the paleontological publications of the California Geo- logical Survey. > U. S. Geol. Snrv., Ball. 51, 1889, p. 29. » TJ. S. Geol. Sarv., Ball. 15, 1885. ' n. S. Geol. Surv., Ball. 51, 1889, p. 29. (Whitney and Gabb, however, mention localities in Lake and Mendocino counties.) » U. S. Geol. Sunr., Ball. 51, pp. 31-32. 6 The Martiuoz groap of Gabb is considered part of the Chico group. " Geol. Snrv. California, Geology, voL 1, pp. 190, 191. 102 THE EOCENE. (bull. 83. In regard to the stratigraphical relations of the Tejon group to the Chico group on the one hand, and the Miocene on the other, White^ and Becker* present some valuable data from the vicinity of New Idria. The former says in regard to the Ohico-Tejon series of that locality, that the strata are mainly sandstones and sandy shales, and adds : They dip to the northward, the angle of dip being high near their contact with the metamorphic series upon which they rest uneonformably; but the dip materially diminishes to the northward. From the contact with the metamorphic series before mentioned the thickness of this whole strata is estimated to be about 10,000 feet. Dr. White further says: The whole assemblage of strata, nearly SJ miles in thickness, forms one continuous series from top to bottom, and the sedimentation which resulted in the production of these strata was uninterrupted from the beginning to the end of the time in which it qpcurred. » • » Although this New Idria series is understood to be practically an unbroken one, there is, near its middle, a, recognizable change in the aspect of the strata, so that in appearance, and to some extent in the character of the stratifi- cation, the upper half differs from the lower half. So far as can be determined, this indistinct line accords with the necessarily artificial division that has been made of the series into the Chico and Tejon groups, since the series is recognized as contain- ing only these two groups, and the line of demarkation between them, as before shown, can not be expected to be distinct. ♦ » * Still the intimate relation of the Chico and Tejon groups for this particular locality is well shown by the unbroken character of the series of strata which here constitutes both groups. Dr. Becker says in this connection that " the Tejon strata of Kew Idria are mostly heavy-bedded sandstones of a peculiarly light color, which thus distinguishes them from the tawny Ghico sandstones." At the same time the evidence for the Eocene age of the Tejon group is shown by Dr. White from the stratigraphical position of the deposits. He says : The opinion that the Tejon group really represents the Eocene is further supported in that no other representative of the strata x)f that epoch has been discovered in California, and also the Miocene strata everywhere rests conformably upon the Tejon. This conformity was recognized by the members of the State Geological Survey of California, and it ha? also been observed in numerous cases by Dr. Becker, as well as in several instances by myself. One of these observations I made at the well known Tejon and Miocene locality at the head of Valleoitos Ca&on, near the place mentioned as " Griswold" in the California reports, which is only a few miles from the New Idria locality just referred to. I then satisfactorily traced the strata from one forma- tion to the other, and found that not only is the conformity of the two formations with each other clearly apparent, but no break in the order of stratification could be detected between those layers which contain characteristic Tejon fossils on the one hand and those which contaid equally characteristic Miocene fossils on the other. In short, I found no room there for the existence of any Eocene strata other than the Tejon. In regard to the stratigraphical relationship of these beds at New Idria, Dr. Becker also says,' " The Miocene seems as strictly conformable with the Tejon as this with the Chico." » v. S. Geol. Sarv., BalL IS. • P. S. Geol. Snrv., Bull. IB. » U. S. QeoL Surv., Ball. 19, ] 885, p. 17. CLAKK.] TEJON GROUP. 103 In Contra Costa County the Tejon group is prominently exhibited as a thick-bedded sandstone, with layers of carbonaceous matter of sufiftcient thickness to afford workable seams of coal. The relationship of the beds is similar to that before mentioned for the region of Few Idria. Prof. Whitney states ' that " all these strata, from the Creta- ceous up to the post-Pliocene, appear to be perfectly conformable to each other." Dr. Becker^ says- upon the same point : The stratigraphical relatioDs » * * show a continuous sedimentation * • » between the Chico and Tejon. Between the Tejon and Miocene there is nowhere any suggestion of a nonconformity. * * * At Mount Diablo, for example, the Miocene seems as strictly conformable with the Tejon as this with the Chico. In regard to the position of the strata Dr. pecker ^ further says: Mount Diablo and the surrounding country consist of a core of metamorphio rock, inclosed, nearly or quite quaquaversally by rooks of Chico and Tertiary age. » * * The overlying Chico, Tejon, and Miocene strata are tilted, but otherwise compara- tively undisturbed. Over wide areas these three series seem to be perfectly con- formable, nor is there any case known on the Pacific coast where there seems any ground for suspecting a nonconformity within these limits. To the north of Mount Diablo, in the vicinity of Martinez, the Tejon group is prominently represented by sandstones that dip southwest at an angle of 36° to 60°. This locality furnished a large number of the fossils described by Gabb. The Tejon strata of Oregon have been found in a few widely sepa- rated localities in the central and northern portions of the State. The most southern yet observed is on Coos Bay. In the Willamette Valley, at Albany, the Tejon occurs as an "ihdurated dark colored shale which was found a few feet beneath the surface of the ground in digging a cistern." Inregard to the age of the deposits at Astoria Dr. White en- tertains doubts, though he considers it probable that the Eocene is rep- resented. Dr. Dall has more recently established the presence of th6 Eocene at this point. He has found it overlain by Miocene and states that a misunderstanding as to the stratigraphical relations of the beds has hitherto existed. The Eocene is found to consist of a thin band of argillaceous material, throughwhich numerous calcareous nodules are scattered, at the center of which fragments of shells are generally found. The stratigraphy of the beds on the Dwamish River, in Washington, have been studied by Bailey Willis in reference to their relationship to the I'uget group and found to aflbrd no data for connection with the strata of that formation. As in the Oregon localities, a comparison of the deposits with those of other areas is based on the similarities afforded by the fossils rather than on stratigraphical grounds. Having thus briefly reviewed the more striking stratigraphical fea- » Geol. Sarv. California, Geology, voL 2, 1864, p. 32. » U. S. Geol. Snrv., Ball. 19, 1885, pp. 18, 17. •Ibid., p. 16. 104 THK EOCENE. [DULL. 83. tures of the Tejon group, an examination of the fossils is imperative, as upon the evidence from that source the taxonomic interpretation of the widely scattered deposits above described must depend. Conrad first and Gabb and White subsequently have described the fauna of that period and drawn conclusions as to the proper position to be assigned to the Tejon group in the geological column. The fossils referred by G-abb ^ to the Tejon group are : Callianassa Stimpsonii Gabb. Aturia Mathewsonii Gabb. Ammonites jugalis Gabb. Typhis antiquus Gabb. Fusus Martmezensis Gabb. F. Mathewsonii Gabb. F. diaboli Gabb. F. californicus Con., sp. ? Neptunea supraplicata Gabb. Neptunea cretaoea Gabb. Perissolax Blake Con., sp. Surcula prseattenuata Gabb. S. sincuata Gabb. S. claytonensie Gabb. S. raricostata Gabb. Bela clathrata Gabb. Cordiera microptygma Gabb. Trltonium diegoensis Gabb. T. tejonensis Gabb. T. fusiforme Gabb. T. Hornii Gabb. T. paucivaricatum Gabb. T. Whitneyi Gabb. T. californicum Gabb. Brachyspbingus liratus Gabb. B. sinuatus Gabb. BuUia striata Gabb. Nassa cretacea Gabb. N. antiquata Gabb. Pseudoliva lineata Gabb. P. volntaaformis Gabb. Olivella Mathewsonii Gabb. Aucillarla elongata Gabb. ? Fasoiolaria Iseviusoula Gabb. F. sinuata Gabb. F. io Gabb. Mitra cretacea Gabb. Whitneyi ficas Gabb. Ficus mamillatus Gabb, FicopsisEemondii Gabb. F. Hornii Gabb. F. Cooperii Gabb. Natica nvasana Gabb. Lunatia Hornii Gabb. L. uuciformis Gabb. Neverita secta Gabb. N. globosa Gabb. Katicina obli qua Gabb. Euspira alveata Con., sp. Morio tuberonlatus Gabb. Soalaria Mathewsonii Gabb. Terebra califoruica Gabb. Niso polita Gabb. Cerithiopsis altemata Gabb. Architectonica cognata Gabb. A. Hornii Gabb. Conns Kemondii Gabb. C. Hornii Gabb. Eimella canalifera Gabb. E. simplex Gabb. Cyprsea Bayerquei Gabb. C. Mathewsonii Gabb. Iioxutrema tnrrita Gabb. Tnrritella uvasana Con. T. martinezensis Gabb. Galerus excentricns Gabb. Spirocrypta pileum Gabb. Nerita triangulata Gabb. Margaritella crenulata Gabb. Dentalinnm Cooperii Gabb. D. stramineum Gabb. Gadus pusillns Gabb. Bulla Hornii Gabb. Cylichna costata Gabb. Megistostoma striatum Gabb. Martesia clausa Gabb. Solen parallelus Gabb. S. diegoensis Gabb. 1 Corbula priraorsa Gabb. C. Hornii Gabb. C. parilis Gabb. Kesera dolabrseformis Gabb. Cymbophora Ashbnrnerii Gabb. Gari texta Gabb. Tellina longa Gabb. T. Eemondii Gabb. ' Geol. Surv. California, Palaeoutology, vol. 2, pp. 207-254. The localities ia Lake -and Mendocino Counties are not considered. The " int6rmediate beds " at Clayton are included in the Tejon group. ci-ABK.] TEJON GROUP. 105 Tellina Hoffmaimiaua Gabb. Crassatella grandis Gabb. T. Hornii Gabb. C. uvasana Cou. T. californica Gabb. Unio penultimus Gabb. Donax latna Gabb. Mytilus ascia Gabb. Veuns aequilateralis Gabb. M. humerus Con. Meretrix uvasana Conn. Modiola ornata Gabb. M. Hornii Gabb. Septifer dichotomus Gabb. M. ovalis Gabb. Stalagmium couoentrioum Gabb. sp. M. californica Con. Avioula pellucida Gabb. Dosinia elevata Gabb. Area Hornii Gabb. D. gyrata Gabb. Cuoullaaa Mathewsonii Gabb. Tapes Conradiana Gabb. Barbatia Morsei Gabb. T. qnadrata Gabb. Axinaea sagittata Gabb. T. cretacea Gabb. A. cor Gabb. Diodna tenuis Gabb. Nucula truncata Gabb. Cardium Cooperii Gabb. Leda Gabbii Con., sp. C. Brewerii Gabb. Pecten interradiatus Gabb. C. linteum Con. Placunanomia inornata Gabb. Cardita Horniii Gabb. Ostrea idiiaensis Gabb. Lncina cumulata Gabb. Flabellum Remondianum Gabb. ? L. cretacea Gabb. Trocbosmilia striata Gabb. Mysia polita Gabb. To this list Dr. White ^ has added— Zirpbsea plana White. Cancellaria Turner! White. The presence of a sufficient number of the fossils above enumerated at each of the leading localities on the east flank of the Cascade Moun- tains renders their correlation probable. Although the number of forms found in the more northern and widely separated Oregon and Wash- ington areas is not so great, yet the identification of the few forms dis- covered leaves little doubt as to the Eocene age of the deposits. In the Willamette Valley at Albany Cardita planioosta La,ma,Tck has been identified, while from Cape Arago Dr. White has recognized — Nucula truncata Gabb. Turritella uvasana Conrad. Cardita planicosta Lamarck. Pusus californicus Gabb. Meretrix uvasana Conrad. Perissolax Blakei (Conrad) Gabb. Naticina obliqna Gabb. Concerning the deposits at Astoria, although considering them in part Miocene, Dr. White is of the opinion that the Chico-Tejon series may be also represented. He says in regard to the similarity of their fossils: The Nucula divaricata of Conrad differs, if at all, from N. truncata Gabb only in the asserted rounding instead of the tnincation of the posterior ("anterior") extremity; and yet one of Mr. Conrad's figures shows such a truncation. The Mactra alharia of Conrad is exceedingly like M. AshiurneriiGahh. The Loripes paralis of Conrad recalls Z. dubia Gabb. The Fyrula modesta or Conrad is possibly identical with Ficus (?) cyprcBoidea Gabb, and the Survey collections contain specimens of Solen from the Tejon group of California, which closely resemble Conrad's figure of S. curtus. Be- sides this the Aturia angustatus of Conrad from Astoria is much like A. mathewsoni Gabb of the Tejon group of California ; and the presence of that genus in the Miocene strata seems out of place. ' Probably Cardita planicosta Lamarck. ' U. S. Geol. Suiv. Bull. 51, 1889, pp. 15, 25. 106 THE EOCENE. Cbi^l.83. The more recent investigations of Dr. Dall, above referred to, estab- lish the truth of these conclusions. He finds that the earlier collections of fossils were made indiscriminately from the Eocene and Miocene hor- izons, and this accounts for the confusion that has hitherto existed. The locality upon the Dwamish Eiver, Washington, is the most northerly one yet known that affords fossils of Tejon age. In a col- lection made at that point the following species have been recognized : Cylichna costata Gabb. Enspira alveata (Conrad) Gabb. Conns Hornii Gabb. Fusns diaboli Gabb. Luuatia nuciformis Gabb. Turritella uvasana Gabb. Leda protexta Gabb. Tellina sp. (?) The above forms establish beyond much doubt the presence of Tejon strata in western Washington.* The faunal relationship of the Tejon group to the Chico on the one hand and the Miocene on the other is deserving of particular atten- tion. It has already been shown that the stratigraphical individuality of the Ohico and Tejon groups is not clearly defined, but that the lat- ter rests conformably upon the former and presents but a slight litho- logical change in its deposits. At the same time several forms are found common to the two groups, and Gabb* gives in the second volume of the Paleontology of California, 15 species. Callianassa Stimpaoni Gabb. Marteeia clausa Gabb. Atnria MathewsoniL Gabb. Mactra (Cymbophora) Aahbnmerii Gabb. Ammonites jugalis Gabb. Tellina HoflfmannianaGabb. Fusus Matbewsonii Gabb. ATionla pellucida Gabb. Euspira alveata Conrad, sp. Cucnllsea Matbewsonii Gabb. Dentaliam Cooperii Gabb. Nucula truncata Gabb. D. stramineum Gabb. Leda Gabbii Conrad, s^. Cylicbna costata Gabb. Upon the forms here enumerated as common to the two groups Heilprin^ has thrown some doubt as to the validity of three, Mactra Ashburnerii Gabb, Tellina Moffmanniana Gabb, and Leda Gabbii Con., sp. That a commingling of species occurs in the Chico-Tejon series seems to be established. Dr. White* says in this connection : " I am satisfied that such a commingling does exist, as before indicated, and that an alternate commingling of species exists throughout the whole of the Chico-Tejon series." On the other hand, although the Miocene conformably overlies the Tejon group, the faunal relations are not so cFearly shown. No species have hitherto been considered identical, though Dr. White says that "a few of the species of each of the two formations are closely related, and it is possible that some of them may yet prove to be specifically identical." ' TJ. S. Geol. Snrv., Bull. 51, 1889, pp. 30-31. ' In California Acad. Sci., Proc, voL 3, pp. 301-305, he gives 16 species, yawtilua taeanut Is omitted, however, in the State Keport and Ammonites n. s. is determined aa Am.jugalia* ■Pliiladelphia Acad. Nat. Sci., Proc, vol. — , pp. 18. «D. S. &eol. Snrv., Bull. 15, 1885, p. 13. ctiEK.) PUGET GROUP. 107 THE PUGET GROUP. The term Puget group has been applied by Dr. White to a series of brackish-water deposits in Washington. They are found along the eastern side of the Puget Sound Basin on the western flank of the Cas- cade Eange, as well as upon the eastern side of the same mountains, although the identity of the strata in the two regions has not yet been fully determined. In the Puget Sound region the best sections have been obtained by Bailey Willis in the Wilkeson and Green River coal fields, while to the east of the Cascade Eange the strata have been identified by the same observer in several localities, which are enumerated as follows: Near the head of the Yakima River and on the Wenatchie River, • • » near Lake Kitohelas, Lake Klealim, and on Schwak Creek, a small tributary of the Yakima from the north • * • south of the Wenatchie, on the spur of the Cas- cades called the Peshasten Range, which divides that river from the Yakima, and at the head of the Mnnastash Creek, 25 miles west of Ellensburg, at an elevation of 5,500 feet on the main Cascade Range.' The strata in the Puget Sound Basin consist of alternating beds of yellow and gray fine-grained sandstones and very fine gray arenaceous shales interstratified with many beds of carboniferous shale and coal ; the individual strata of sandstone and shale, from 20 to 200 feet thick, maintain the same general character wherever ob- served, and no well defined horizon has yet been found which might serve as an index to correlate the widely separated exposures.' Mr. Willis, whose description of the deposits has just been quoted, estimates the maximum thickness of the strata at over 10,000 feet. In the Wilkeson field he states that there "are 127 carbonaceous beds, of which 17 are workable coal veins, 3 to 15 feet thick." To the east of the Cascade Range a similar development of carbonaceous strata has an ap- proximate thickness of 1,000 feet, and rests on coarse sandstone and conglomerate. The character of the deposits and their entombed fossils show that brackish-water conditions certainly prevailed over the area in whiish the strata are now exposed, and doubtless over a much wider region. If the coal-bearing strata upon the eastern and western flanks of the Cas- cade Range prove to be of the same age the topography of the period must have been very different from the present, and since the carbon- aceous strata have been found absent from the higher portions of the Olympic and Northern Cascade Mountains, it has been supposed that those ranges may have constituted an island and a peninsula respec- tively. Acting as barriers against the open sea the estuarine condi- tions necessary for the formation of the carbonaceous strata may have been developed. ■lentil Census BepoTt, vol. IS, p. 761. >Ibid.,p.7S9. 108 The eocene. ibuix-ss. The following Invertebrate fossils have been obtained from the Puget group -^ Cardium (Adacua?) sp. Psammobia obscura White. Cyrena brevidens White. Sangninolaria ? candata White. Corbicula pugetensis White. Teredo pugetensis White. Corbicula Willisi White. Neritina sp. Batissa Newberryi White. Cerithium ? sp. Batissa dabia. Among the plant remains examined by Prof. Newberry^ are Splienop- tens {Aspletiium) elongata Newberry, which, according to that distin- guished paleontologist, is the same as Gymnogramma Haydeni Lesq., Asplenium subcretaceum Saporta, and Anemia subcretacea Gardner, an important and widespread species. Galamosis Dance Lesq., Onoclea sen- sibilis Linn., Lygodium Kaulfussi Herr, the latter probably identical with L. neuropteroides Lesq., are mentioned by the same investigator as rep- resented in the Puget group. GROUNDS FOB THE REFEEBNCE OF THE TEJON AND PUGET GROUPS TO THE EOCENE. In the preceding remarks on the Pacific Coast region the assump- tion has been made that the Tejon and Puget groups are the equivalents of the Eocene of other areas. As this position has been much discussed in the past, particularly as regards the Tejon group, and is not admitted by all geologists to-day, the evidence for their reference to the Eocene will be briefly outlined. In the Historical Sketch it was stated that Whitney and Gabb con- sidered the entire Ohico Tejon series as Cretaceous, while Marcou as zealously advocated its Tertiary age. In the present paper the Chico is referred to the Cretaceous, the Tejon to the Eocene. Before considering the grounds for this division of a conformable series of deposits that at the same time possess in common several iden- tical species, let us first examine the evidence for referring the entire formation to the same horizon, in the one case to the Cretaceous and in the other to the Eocene, The lower division, the Chico, contains a large number of ammonitic forms, which have been hitherto considered by paleontologists to denote the Mesozoic age of the strata in which they are found, among which species of Hamites, Turrilites, Ancyloceras, Crioceras, and Baculites are included, while the lamellibranchiate genera, Trigonia, Inoceramus, Gryphsea, and Exogyra, likewise considered Mesozoic in character, are not uncommon. In the upper division, the Tejon, Ammonites jugalis Gabb is found, while several genera of gasteropoda are also cited by Gabb as characteristically Cretaceous, though their determination is shown by Conrad and Heilprin to be founded on error as to the generic rela- tions of the specimens or the localities from which they were derived, ' v. S. Geol. Sarv., BuU. 51, p. 68. * Ibid., p. 51. CI.ARK.1 AGE OF THE DEPOSITS. 109 Ooncerniug the reference of the entire Chico-Tejon series to the Ter- tiary, on the other hand, Marcou states that the Ammonites are degen- erate types, and further that there is "no law which makes it necessary for Ammonites * * • to disappear entirely from the surface of the terrestrial' globe with the rocks of the secondary epochs." Prom the Chico he cites the presence of the following genera that collectively he considers indisputable evidence for the Tertiary age of the fauna: Fusus, LsBvifusus, Neptunea, Sycodes, G-yrodes, Natica, Architectonica, Stra- parollus, Pugnellus, Anchura, Littorina, Turritella, Nerita, Lysis, Cal- liostoma, Angaria, Margaritella, Dentalium, Patella, Helcion, Kingi- cula, Cinulia, Oylichna, Martesia, Siliqua, Oorbula, Anatina, Oymbo- phora, Lutraria, Asaphis, Tellina, Venus, Ohione, Meretrix, Caryatis, Dosinia, Trapezium, Cardium, Olisocolus, Lucina, Astarte, Anthonya, Mytilus, Modiola, Meleagrina, Meekia, Area, Oucullsea, Nucula, Leda, Pecten, Lima, Anomia, and Ostrea. For the Tejon he states that the Tertiary genera, Pusus, Tritonium, Trachytriton, Olivella, Fasciolaria, Lunatia, Turritella, etc., are numer- ous, and that Eocene species identical with those in Alabama and the London and Paris basins are found. It seemsto me, as already stated by Dana, White, and Heilprin, that the writers above quoted are in part right, in part wrong. The pres- ence of so large a number of ammonitic forms in the Chico, together with such types as Inoceramus, Trigonia, Gryphaea, and Exogyra, is sufiQcient indication of the Cretaceous age of the Chico group. On the other hand, the presence in the Tejon of Lunatia, Crepidula, Turritella, Tritonium, Nassa, Mitra, Pseudoliva, Oliva, Conus, Cyprssa, Eimella, and Donax, together with Gardita planicosta Lam. and other species identical or closely related to characteristic Eocene forms of other re- gions, although associated with a few ammonitic remains of -a single species, is sufficiently strong evidence of its Tertiary age. That no marked break occurred in the continuity of life in the Chico- Tejon series is proved by the fact that several species are found com- mon to the upper and lower divisions. Deposition, from the structure of the beds and the absence of unconformity, was probably continuous. Forms that were numerous in the early part of the period gradually disappeared, and their place was taken by others that increased in im- portance toward its close. To what horizon of the Eocene the Tejon should be referred can not be definitely stated. Conrad considered it Lower Eocene, while Marcou has stated that it belongs to the upper division. The presence of Gardita planicosta Lam. serves only for general comparison since it has been found ranging from the lower to the upper members of the Eocene in the Atlantic and Gulf Coast region. Heilprin and Marcou have shown the close relationship if not identity of several other spe- cies. Gardita Ho,rnii Gabb is held to be identical with G. planicosta, Lam. Dosinia elevata Gabb is thought to be the same as Dosiniopsis 110 THE EOCENE. [buluSS. Meekii Oonrad, so common in the Maryland and Virginia Eocene. Fi- copsis {Hemifusus) Remondii Gabb is considered to be very closely related to if not identical with Pyrula penita Conrad from Claiborne, Alabama. Other comparisons are made, some with forms from the Paris Basin and the English Eocene. From the fact that the Tejon conformably overlies the Chico and is in turn conformably overlain by the Miocene it is not improbable that the Tejon represents the entire Eocene series as elsewhere developed, but upon this point we have as yet too few data to draw conclusions. Further investigation may show that some important points have been hitherto overlooked. The Puget group has been referred to the Eocene, though there is some doubt as to whether the entire formation can be properly consid- ered such. In its flora Prof. Newberry has shown that the Puget group is to be closely compared to the Laramie, though the conditions under which the deposits of the former were accumulated were, in many par- ticulars, unlike that of the latter. If the Puget group is to be corre- lated with the Laramie, it is not improbable that we have in the former the representatives of both the Chico and Tejon groups, and thus, as in both the Laramie and Chico-Tejon series, the break between the Cre- taceous and the Eocene is, in part at least, bridged over. If such proves to be the case, the Puget group must be referred in part to the one horizon, in part to the other. Prof. Newberry has compared Sphenopteris {Asplenium) elongata New- berry from the Puget group with Gynmogramma Haydeni Lesq. from the Laramie. He also has little doubt of the presence of Onoclea sensi- hilis Linn., which occurs in abundance at Port Union. In regard to the faunal similarities of the Puget group and the Laramie Dr. White says: Such a comparison is especially suggested by the known floral relations of the two groups of strata, their presumble contemporaneity of origin, and the nonmariue character of the mollascan faunas of both. Upon making a comparison, however, important zoological differences appear. It is true there are two species of Corbi- cula in the Fuget fauna that are so closely like Laramie forms as to suggest specific* identity upon casual examination, but the differences between the two faunas are strikingly shown by the family and generic characters of the other members of the Pnget fauna as compared with the Laramie fauna. Teredo, Tellina, and Batissa occur in the Puget group, but are absent in the Laramie.' The later genus has particular interest from the fact that it has not been found in North America before. It is confined to the Pacific Islands and Asiatic Continent. At the same time the Puget group shows some points of similarity to the Lignitic of the Gulf border. Galamopsis BancB Lesq. of Mississippi has been identified by Prof, Newberry. INTERIOR REGION. PEELIMINARY EEMAKKS. The Eocene of the Interior region covers an extensive area on the eastern and western flanks of the Kooky Mountains. Though largely developed in broad contiauous tracts, it not infrequently occurs in narrowly circumscribed basins that are found scattered from Colorado on tfie east to Nevada on the west, and from Montana on the north to Texas on the south. Within the limits designated similar conditions largely prevailed. Prom an open sea of Cretaceous age, in which the life was marine, a gradual change took place to great fresh-water lakes in which the typical Tertiary deposits of the Interior were accumulated. Although the marine and fresh- water divisions present marked pale- ontological differences, they are still linked together by a series of brackish-water deposits that afford many points for comparison with both the older and younger horizons. Whether these intervening beds should be referred to the Cretaceous or to the Eocene or considered to represent portions of each has been widely discussed, and no problem in American geology has perhaps furnished so extensive a literature. It seems not improbable that continuous deposition prevailed through- out the Interior region, so that the reference of each member of the series to the more or less fragmentary geological column elsewhere es- tablished is attended with great uncertainty. The opinions of those who have studied the deposits from different points of view differ widely, though the present tendency is to dispar- age a narrow interpretation of any particular series of facts and to judge the evidence in its entirety. It will be observed that the Laramie and Puerco formations, regarded by many as Cretaceous, and the Port Union beds, which by others have been separated from the Laramie and held to be Neocene, are here dis- cussed. The evidence for the Eocene age of all or part of the strata of these several formations will be presented in subsequent pages ; and the history, stratigraphy, taxonomy, and correlation of the Eocene of the Interior, in its general and local characters, will be briefly outlined. HISTORICAL SKETCH. The reports of the expeditions that entered or crossed the Interior region during the first half of the century present almost nothing of importance upon the Eocene, Oertaiu observations iu areas now known 112 THE EOCENE. [buli.83. to be of Tertiary age are recorded, but neither the stratigraphical re- lationship of the deposits nor their taxonomy were in any degree com- prehended. The investigations of Meek and Hayden in Nebraska and the Upper Missouri Kiver country, in 1854, afford the first scientific data upon the geology of the region that it is our province to discuss. The publica- tion of these results appeared in a series of articles in the Proceedings of the Academy of Natural Sciences of Philadelphia for 1856, and from the fossils collected upon that expedition the authors concluded : It is worthy of note that some of the species contained in the collection from the most recent Cretaceous beds of the Upper Missouri coantry appear referable to genera ■which, according to high European authority, date no farther back than the true chalk, while many of them are closely analogous to Tertiary forms ; so close, indeed, that had they not been found associated in the same beds with Ammonites, Soaphites, and other genera everywhere regarded as having become extinct at the close of the Cretaceous epoch we would have considered them Tertiary species.' Already, at this early period, the peculiarities of the organic remains in the beds intermediate between undoubted Cretaceous and undoubted Eocene were recognized. In a subsequent paper'' the same authors refer the lignite deposits of the Upper Missouri Eiver to the Tertiary. They say: Although there can be no donbt that these deposits hold a rather low position in the Tertiary system, we have as yet been able to arrive at no very definite conclu- sions as to their exact synchronism with any particular minor subdivision of Ter- tiary, not having been able to identify any of the moUusca found in them with those of any well marked geological horizon in other countries. Their general resemblance to the fossils of the Woolwich and Reading series of English geologists, as well as to those' of the great lignite formations of the southeast of France, would seem to point ta the lower Eocene as their position. In regard to the Judith Eiver deposits, which Dr. Leidy' had already compared to the Wealden of Europe, the same writers add : Inasmuch, however, as there certainly are some outliers of fresh-water Tertiary in these Bad Lands, we would suggest that it is barely possible these remains may belong to that epoch, though the shells appear to be all distinct species from those found in the Tertiary at all the other localities in this region. Notwithstanding these statements, the same authors, in a section given in later article,* following the conclusions of those who had examined the vertebrate and vegetable remains, refer the Judith Eiver deposits to the lowest horizon of the Cretaceous, while the Fort Union beds are considered Miocene. A geological map, prepared by Dr. Hayden, of the region bordering the Missouri Eiver, appears in the next volume of the Proceedings of Philadelphia Academy,^ on which the limits of the " Great Lignitic Ter- 'PMladelpWa Acad. Nat. Sci., Proc, vol, 8, 1856, p. 63, 2Ibia.,pp. ill-128. »Ibid., pp. 72,73. '- 4 Ibid., p. 269. "Ibid., vol. 9, 1857, p. 100. CLAUK.] HISTORICAL SKETCH — INTERIOR. 113 iiiiry Baslu " are recorded. In regard to the Great Lignitic deposit he states that " the collectiou of fossils now obtained show most conclu- sively * * * that it can not be older than the Miocene period." Small areas in Wyoming, on the Sweetwater, and to the west of South Pass are designated as Tertiary. Similar conclusions are given in a longer paper by Meek and Hayden,' that immediately follows that presented by Dr. Hayden. In the proceedings of the Academy of Natural Sciences for 1860 Meek and Engelmann refer the Bear Eiver Estuary Beds^ to the Tertiary. In the same journal for 1801^ Meek andHayden published a complete section of the Tertiary formations of the northwest. A fourfold divi- sion is made: (1) Port Union, or Great Lignite group ; (2) Wind Eiver deposits ; (3) White River group ; (4) Loup Eiver beds. The first two alone claim our attention. The Port Union or Great Lignite group is described as characterized by — Beds of clay and sand, with round ferruginous concretions and numerous beds, seams, and local deposits of lignite; great numbers of dicotyledonous leaves, stems, etc., of the genera PJatanua, Acer, CJlmus, Populus, etc., with very large leaves of true fan palms. Also, Helix, Melania, Vivipara, Corbicula, Unio, Ostrea, Potamomya, and scales of Lepidotus, with bones of Trionyx, Emys, Compsemys, Crooodilus, etc. Thickness: 2,000 feet or more. Localities: Occupies the whole country around Port Union, extending north into the British possessions to unknown distances; also southward to Fort Clark. Seen under the White Eiver grouj) on North Platte Eiver above Fort Laramie, also on west side Wind Eiver Mountains. The Wind River deposits are described as — Light-gray and ash-colored sandstones, with more or less argillaceous layers. Fos- sils: fragments of Trionyx, Testudo, with large Helix, Vivipara, petrified wood, etc. No marine or brackish- water types. Thickness: 1,500 to 2,000 feet. Locali- ties: Wind River Valley; also, west of Wind Eiver Mountains. Concerning the position of the Wind Eiver group in the Tertiary series they say : As the Wind Eiver deposits have not yet been seen in contact with any well marked beds of the other Tertiary formations of this region, and few fossils have yet been found in them, their position .in the series remains doubtful. It ia therefore, only provisionally that we have placed this formation between the Fort Union and White Eiver groups in the foregoing section. Ooncerning the Judith Eiver deposits, a foot-note to page 417 con- tains the following: At the time we published these facts we were led by the discovery here of fresh- water shells, in such a position, to think that some estuary deposits of doubtful age, near the month of the Judith Eiver, on the Missouri, from which Dr. Leidy had described some Saurian remains resembling Wealden types, might be older than Tertiary. Later examinations, howover, have demonstrated that the Judith beds contain an entirely different group of fossils from those found in the rock under con- sideration, and that they are really of Tertiary age, and hold a position at the base of the Great Lignite series of the Northwest. 'Philadelphia Acad. Nat. Sci., Proc, vol. 9, 1857, pp. 117-U8. 2 Ibid., vol. 13, 1860, p. 130. sjbid., vol. 13, 1861, p. 433. Bull. 83 — :-8 114 THE EOCENE. Ibull.83. The same section of the Tertiary strata of the Northwest is repeated in the First Annual Report of the Geological Survey of the Territories for 1867. In the discussions that follow, the Judith Eiver deposits are placed with the Port Union beds as part of the same great series. The more southern extension of the lignitic formation is now for the first time clearly recorded from Wyoming and Colorado and southward as far as Raton Pass in New Mexico. Oapt. E. L. Berthoud, whose letter upon this point is included in this first official report of Dr. Hayden, says concerning the age of the lignitic series: "Everything that I have so far seen points out that the coal is either (Jretaceons or Tertiary, but I believe it to be Tertiary or of the same age as the coal near Cologne, on the Rhine." Concerning the Wind River deposits he states further on that " they occupy an area about 100 miles in length and 40 to 50 in breadth." In an article entitled " Notes on the Lignite Deposits of the West," in the American Journal of Science ' for March, 1868, Dr. Hayden reit- erates his previous views. The same year Dr.J. S. Newberry'* published "Notes on the Later Extinct Flora of North America, with descriptions of some new species of fossil plants from the Cretaceous and Tertiary Strata," in the Annals of the Lyceum of Natural History of New York. In this paper the flora of the Fort Union beds is described. Up to this time there had apparently been complete unanimity on the subject of the Tertiary age of the lignitic series, the only varying evi- dence being found in what Dr. Leidy considered the Wealden type of the Judith River vertebrates. From the discovery of specimens of Inoceramus in the coal strata at Eaton Pass, New Mexico, Dr. J. D. Le Conte^ claimed that the lignitic deposits of that region were accordingly Cretaceous, though still ad- mitting the Miocene age of the Fort Union beds. Prof. E. D. Cope ^ raises a doubt concerning the Tertiary age of the entire lignitic series in an article in the transactions of the American Philosophical Society by mentioning Isohyrosaurus antiquus Leidy from the " Great Lignitic " of Nebraslia as " perhaps of the Cretaceous age," and Radrosaurus f occidentalis Leidy from the " Cretaceous beds " of Nebraska, while Palceoscincus costatus Leidy is referred to the " upper Jurassic Bad Lands of Judith River." In the Third Annual Report of the Geological Survey of the Terri- tories, Dr. Hayden describes the Tertiary strata under provisional " groups." The lignitic strata are thus locally divided into the Fort Union group, Canon City group, Raton Hills group, etc., while sepa- rated from the true coal-bearing series in the vicinity of Bitter Creek ■ Am. Jour. Soi., 2d ser., vol. 45, 1868, pp. 198-208. 'Annals. Lyceum Nat. Hist., New York, toI. 9, 1867, pp. 1-76. 3Notea on the Geology of the Survey for the extension of the Union Pacific Railway, E. D., from the Smoky Hill Eiver, Kansas, to the Eio Grande. Philadelphia, 1868. * Am. Phil. Soc, Trans., vol. U, 1868- '69, pp. 1-252. CLARK.) HISTORICAL SKETCH — INTERIOR. 115 is the Wasbakie group. The Greea Eiver shales, Bridger group, and Wasatch group are characterized, though their relations are not fully understood. The Washakie group and Green Eiver shales are held to be Middle Tertiary, the Bridger group Upper Tertiary, while the Wa- satch group is simply designated as of Tertiary age. The volume upon mining industry, of the quarto publications of the U. S. Geological Exploration of the Fortieth Parallel, appeared in 1870, and includes a chapter upon the Green Eiver coal basin, in which the author, Mr. Clarence King, states that the coal-bearing strata are mainly Cretaceous and are unconformably overlain by fresh- water de- posits of Tertiary age. In this connection he says : The fossil life, which clearly indicates a Cretaceous age for the deepest memhers up to and including the first two or three important coal beds, from that point grad- ually changes with a corresponding alteration of the sediments, indicating a transi- tion to a fresh-water period. The coal continued to be deposited some time after the marine fauna had been succeeded by fresh-water types. The species of fossils are in no case identical with the California Cretaceous beds, which occupy a similar geo- logical position on the west of the Sierra Nevada. Their affinities decidedly ap- proach those of the Atlantic slopes, while the fresh- water species which are found in connection with the uppermost coal beds seem to belong to the early Tertiary period.' He states furthur concerning the unconformity of the Tertiary beds and the underlying coal-bearing strata: Whatever may be the relations of these beds in other places, it is absolutely certain that within the region lying between the Green River and the Wasatch, and bounded on the south by the Uinta Range, there is no single instance of conformity between the coal beds and the horizontal fresh-water strata above them.' In a letter from Mr. Meek, published in the same chapter, that writer concludes from the presence of Inoceramus and Anchura and the un- conformity that exists between the coal-bearing strata and the fresh- water beds that "from all the facts now known I can, therefore, scarcely doubt that you are right in referring these beds to the Cretaceous.'" He states further that " these beds belong to one of the very latest members of the Cretaceous; or, in other words, that they were prob- ably deposited when the physical conditions favorable to the existence of those forms of moUuscan life, peculiarly characteristic of the Creta- ceous period, were dra,wing to a close, or had in part ceased to exist."* Concerning, the Bear Eiver beds which Meek and Bngelmann had re- ferred in 1860 to the Tertiary, the former now admits that they may be Cretaceous, and suggests "the inquiry whether we ought not to carry up the line between the Cretaceous and Tertiary here, so as to include these estuary beds also in the Cretaceous."^ The similarity of the Ju- dith Eiver deposits is stated in support of this position, " from the fact that there is a formation on the Upper Missouri, near the mouth of the Judith Eiver, the exact age of which has long been regarded as some- what doubtful, though Dr. Hayden and the writer have generally placed > Op. cit, p. 453. 2 p. 455. ^PA61. «P.462. 'P.464. 116 THE EOCENE. [bull. 83. • it in the Tertiary, that contains an exactly similar brackish-water group of fossils, some of which are identical with those found in these Bear Eiver estuary beds." Nevertheless, in summing up, at the close of the letter, the changes that took place during and subsequent to the formation of the coal- bearing strata Meek still clings to his previously expressed idea. He says : Whether or not this change from marine to estuary conditions was exactly contem- poraneous with the close of the Cretaceous and the commencement of the Tertiary of Europe -we may perhaps never know, but that it corresponded in the sequence of geological changes here with the change of physical conditions that closed the Cre- taceous epoch and ushered in the Tertiary of Europe, especially in France, seems to me scarcely to admit of any well grounded doubt."' Although he thinks grounds may be found for including portions of tLe lignitic strata in the Cretaceous, yet he says that all the molluscan remains " seem to point to a later origin." In an article in the American Journal of Science for 1871,^ entitled " On the Geology of the Eastern Uintah Mountains," Prof. Marsh gives the results of an expedition of the " Yale College Scientific Party " the previous summer into the Green Eiver Valley. The topographical aud stfatigraphiSal characteristics of the early Tertiary deposits of the region are given, together with some general remarks on the character of the vertebrate fauna. In regard to the lignitic deposits Prof. Marsh says: As the age of the coal deposits of the Kocky Mountain region has of late been much discussed, a careful examination was made of the series of strata containing the pres- ent bed, and their Cretaceous age established beyond a doubt. In a stratum of yel- low calcareous shale which overlies the coal series conformably, a thin layer was found full oiOstrea congesta Conrad, a typical Cretaceous fossil ; and just above, a new and very interesting crinoid, allied apparently to the Marsapitea of the English chalk. In the shales directly below the coal bed, cyclodial fish scales and coprolites were abundant, and lower down remains of turtles of Cretaceous types, and teeth of a Dinosaurian reptile resembling those of Megalosaurus, were also discovered. In the Fourth Annual Report of the Geological Survey of the Terri- tories for 1870 (published in 1872), Dr. Newberry maintains the Ter- tiary age of the Fort Union beds, a position that had been generally accepted for the northern lignitic strata. Concerning the age of the lignitic deposits of Wyoming, Dr. Hayden states in the same report that " so far as we can determine the coal beds of the Laramie plains are of Eocene age, although the plants are more closely allied to those of the Miocene period in the Old World."' Further he says: That there is a connection between all the coal beds of the West I firmly believe, and I am convinced that in due time that relation will be worked out and the links in the chain of evidence joined together. That some of the older beds may be of Upper Cretaceous age I am prepared to believe, yet until much clearer light is thrown upon their origin than any we have yet secured I shall regard them as belonging to my transition series or beds of passage between the true Cretaceous and the Tertiary .< '0p.cit.,p.466. 3 Op. cit, p. 164. » Am, Jour. Soi., 3d ser.. vol. 1, 1871, pp. 191-198. « Op. cit., p. 165. c>-AKK,l HISTORICAL SKETCH — INTERIOR. 117 The Tertiary ago of tlie ligaitic strata is claimed in the same report by Lesquereux, who had studied the fossil plants collected in both Wyoming and New Mexico. The same volume contains an extended description by Dr. Hayden of the Tertiary basin of Southern Wyoming. The following terms : (I) Washakie group, (II) Wasatch group, (III) Green Eiver group, (IV) Bridger group, are used. The strata are considered Miocene in age and unconformable to the underlying deposits. The lithological and topo- graphical characteristics of the several groups in their local develop- ments are given and the occurrence of fossils noted. A letter from Dr. Kewberry, published in Hayden's report, assigns the Green Eiver shales to an earlier period than that stated by Hayden and presents plant evidence for their Eocene age. Concerning the Washa- kie group Hayden says : Although I have hitherto regarded the group of beds which I have denominated the "Washakie group" as separated from those of Green River and to the westward, yet I am now inclined to believe that the upper series is either an extension eastward of the Bridger group, or synchrouous with it.' The Wasatch group is shown to be below the Bridger group and prob- ably synchronous with the Green Kiver shales. The position of the Bridger group above the Green Eiver group is established. The Fifth Annual Eeport of the Geological Survey of the Territories for 1871 (published in 1872) contains an attempt by Lesquereux to cor- relate the lignitic deposits of the numerous localities hitherto described with the different horizons of the Tertiary recognized in Europe. Strong evidence for the Cretaceous age of the lignitic deposits had been up to this time brought forward by King, Marsh, and Cope, and, as we have seen, reluctantly accepted by Meek, so that the evidence from plant remains was alone left to establish the Tertiary age of the strata. The discovery, during the summer of 1872, of the remains of a Dino- saurian reptile at Black Butte station, on the Union Pacific Eailroad, in Wyoming, tended more completely to establish the Cretaceous age of the lignitic deposits. Prof. Cope, who examined the fossils collected from this locality, says : From the above description it is evident that the animal of Black Buttes is a Dino- saurian reptile. * * * It is thus conclusively proved that the coal strata of the Bitter Creek Basin of Wyoming Territory, which embraces the greater area yet dis- covered, were deposited during the Cretaceous period, and not during the Tertiary, though not long preceding the latter.^ In another article' he says : " this discovery places this group with- out doubt within the limits of the Cretaceous period." The separation of the "Bitter Creek series" as a distinct group had been already re- corded by Prof. Cope in the previous paper. In the Sixth Annual Eeport of the Geological Survey of the Territories for 1872 (published in 1873) Lesquereux reasserts his former conclusions 'Op.oit.,p.73. »Am. PhU. Soc, Proc, vol. 12, 1872, p. 483. SAm.Nat., vol. 6, 1872, pp. 669-871. 118 THE EOCENE. [BUtt.,83. as to the Tertiary age of the entire coal bearing series which he denom- inates the "American Eocene." The Washakie group he assigns to the Upper Eocene, while the Green Eiver group is considered Miocene. In the same report Meek considers the " Bitter Creek series " to be of Cretaceous age, and describes many fossils therefrom. The Bear River deposits he thinks may still be Tertiary. In regard to the lignite de- posits of Wyoming he says : But the most surprising fact to me, supposing this to be a Cretaceous forraatiou, is that we found directly associated with the reptilian remains at Black Butte a shell I can not distinguish from Viviparus trochiformis, originally described from the lignitic formation at Fort Clark, on the Upper Missouri, a formation that has always beenregardedas Tertiary by all who have studied its fossils, both animal and vegetable. » « • The occurrence of this last mentioned species here, along with a Cretaceous type of reptile and a Gorbimila apparently identical with C. cytheriformis of the Judith River brackish-water beds, together with the presence of Corbulas very oloselj' allied to Judith Eiver species, at lower horizons in this series, and the occurrence of some vertebrates of Cretaceous affinities at the Judith Eiver localities, would cer- tainly strongly favor the conclusions not only that this Judith formation, the age of which has so long been in doubt, is also Cretaceous, but also that even the higher fresh- water lignite formation at Port Clark and other Upper Missouri localities may also be Upper Cretaceous instead of Lower Tertiary.' In the same report Cope has an article "On the Extinct Vertebrata of the Eocene of Wyoming." The genus Amyzon is described from Osino, IJfevada. Dr. Newberry^ presents a paper in the April number of the American Journal of Science of the same year, in which he asserts that much of the flora that Lesquereux had described from New Mexico as Eocene he is certain is Cretaceous, while other forms from the Fort Union beds, referred to the same horizon, he is confident are Miocene. Lesquereux^ defends his position in a later number. Prof. Cope states in the Bulletin of the U. S. Geological and Geo- graphical Survey of the Territories, No. 1, that — Believing, as I do, that the evidence derived from the vertebrate remains requires the reference of the Bitter Creek coal series to the Cretaceous period, and having pointed out, on similar grounds, that the horizon of the Great Lignite from which vertebrate remains have been procured on the Missouri River is undoubtedly Meso- zoic, although usually regarded as Tertiary, 1 suspect that the corresponding strata in Colorado will be found to pertain to the same section of geologic time.* In Bulletin No. 2 the same writer has an extended discussion " On the mutual relations of the Cretaceous and Tertiary formations of the West." In a second paper the Tertiary fishes from Middle and Sontii Parks, Colorado, are described. The first article is reproduced in much the same form in the Seventh Annual Report of the U. S. Geo- logical and Geographical Survey of the Territories for 1873 (published in 1874). In this paper the author, considering the Fort Union and ' Op. oit., p. 460. 3 Ibid., pp. 546-557. ' Am. Jour. Sci., 3d ser., vol. 7, 1874, pp. 399-404. *0p. oit., p. 10. CLARK.] HISTORICAL SKETCH-— INTERIOR. 119 Bitter Creek series of like age. but at the same time acceptiDg the evi- dence offered on the side of paleobotany, says : There is, then, no alternative but to accept the result that a Tertiary flora was contem- poraneous mth a Cretaceous fauna, estahlishing an uninterrupted succession of life across what is generally regarded as one of the greatest breaks in geologic time.' The same volume contains reports by Marvine and by Lesquereux, in which the latter still defends his position of the Eocene age of the greater part of the lignitic strata, though the Bvanston beds are con- sidered younger and are placed in the upper portion of the series. To the Miocene (middle) he refers (he coal basin of Carbon, the Washakie group, and "other deposits. To the Miocene (upper) the Green River group; the coal of Elko, ISTevada; the Florissant, Colorado, beds ; and the deposits of Middle Park. Cope, in the same volume, maintains that from the evidence of vertebrate paleontology the deposits of the Wa- satch group are synchronous with the Green Eiver. The same writer speaks of the " Bridger Eocene." Dr. George M. Dawson'* published in 1874r-'75 several articles bear- ing on the age of the Fort Union beds, and is decidedly of the opipion that they are Eocene. Two important contributions from the pen of Prof. Cope appeared in 1875. In the first,' which included an account of the vertebrates collected by Dawson on the British boundary, the author finds that " the list of species, short as it is, indicates the future discovery of a complete transition from Cretaceous to Eocene life." The second contribution is the final report on Cretaceous verte- brates, published as Vol. ii of the U. S. Geological Survey of the Terri- tories. It contains the paper already twice referred to. Concerning the occurrence of identical forms in the Fort Union and Judith Eiver deposits, he says : The presence of gar fishes of the genus CZaste in this formation is as yet peculiar to this and the J udith Eiver localities. As these gars have not heretofore been found in North America below the Eocene, they constitute the first case of apparent com- mingling of Tertiary and Cretaceous animal life yet clearly determined. Prof. J. J. Stevenson published about this time, in several articles, evidence of a stratigraphioal character to show the Cretaceous age of the lignitic deposits.* In the annual report for 1875 of the U. S. Geographical Surveys west of the One Hundredth Meridian, Prof. Cope characterizes the Puerco group and refers it without qualification to the Eocene. He estimates the thickness of the strata at 1,200 feet. The published results of Maj. J. W, Powell's explorations of the Colo '0p.cit., p. «2. 'Csmadian IfatuTalist, Tol. 7, 1874, p. 241. British North American Boundary Commission, Montreal, 1874. Ibid., 1875. s Philadelphia Acad. Nat. Sci., Proc,,-vol. 27, 1875, pp. 9, 10. 'NewTorkLycenm Nat.Hi8t.,Proo.,2d s6r.,No.4,1874, p.93; TT.S.Geog. Survs. west 100th Mer., vol. 3, 1875, pp. 404-410 ; Am. Phil. Soc , Proc, vol, 14, 1875, pp. 447-475. 120 THE EOCENE. tBULi,.83. rado River of the West appeared in 1875. In this report, the section of Eocene strata exposed on the Green Eiver south of Green River Station, on the Union Pacific Railroad, is described in the itinerary of the journey. The Eighth Annual Report of the Geological and Geographical Survey of the Territories for 1874 (published in 1876) contains far more than any previous publication concerning the lignitic strata. In that por- tion contributed by Dr. Hayden " the coal-bearing beds of the Laramie Plains and Colorado" are correlated with " the vast group in the North- west," though exception is made of "the Bear River and Coalville group," which is considered Cretaceous. Dr. A. C. Peale published in this volume a comparative table setting forth the various opinions that had prevailed as to the several " groups" under consideration. Concerning the Green Eiver and Bridger groups he says that " Profs. Cope, Leidy, and Marsh consider them Eocene, basing their conclusions on the discovery of vertebrate organic remains, while Lesquereux refers them to the Miocene, from his investigations of their fossil flora, calling the ' Lignitic' group Eocene." ' He considers that." the lignite-bearing beds east of the mountains in Colorado are the equivalent of the Fort Union group of the Upper Missouri, and are Eocene Tertiary; also that the lower part of the group, at least of the locality 200 miles east of the mountains, is the equivalent of a part of the lignitic strata of Wyoming," while " the Judith Eiver beds have their equivalent along the eastern edge of the mountains below the Lignite or Fort Union group, and also in Wyoming, and are Cretaceous, although of a higher horizon than the coal-bearing strata of Coalville and Bear River, Utah." ^ Lesquereux gives an extended argument for the Tertiary age of the lignitic deposits. In his final report on Invertebrate Paleontology Meek states that it "is certainly highly probable "that the tludith River beds are Cretaceous, although he still maintains that the Fort Union beds are lower Eocene. Further, he says, "the presence or absence of lignite proves nothing of itself, as lignite undoubtedly occurs in both Cretaceous and Tertiary rocks in the far West." The Wind River group he considers to be Miocene, and "probably wholly or in part equivalent to that since called the Bridger group."' The geological report by J. S. Newberry of the exploring expedition under Capt. J. N. Macomb in 1859 appeared in 1876. In this report the deposits that had been given the name of Puerco group by Cope are described and referred to the upper portion of the Cretaceous. The geology of the Uinta Mountains, by Maj. J. W. Powell, was published in 1876. In this report the Bitter Creek series is fully dis- cussed by Maj. Powell and Dr. White. At a point between Black Buttes and Point of Rocks a "physical break" is announced that ' Op. cit., p. 140. 3 xj. s. Geological Snivey of the Territories, toI. 9, 1870, ' Op. Clt., p. 155. CLAEK.] HISTORICAL SKETCH — INTERIOR. 121 affords grounds for drawing there the line of separation between the Mesozoic and Cenozoic formations. The Point of Eocks group below the break is referred to the Cretaceous, the Bitter Creek group, above the same, to the Tertiary. Maj. Powell says : All of the plants described by Prof. Lesquereux and collected by himself and others within this province have been referred by him to divisions in the Tertiary and are found in strata above the physical break, aud hence I agree with him in con- sidering them Tertiary. * » * The conclusions reached from a study of the ver- tebrate paleontology by Profs. Leidy, Marsh, and Cope entirely harmonize vrith this division of the Cenozoic and Mesozoic' A single exception is cited. Dr. White arrived at conclusions similar to those of Maj. Powell. Ha says : Th«re is no-physical break in the Cretaceous strata from the base of the series to the top of the upper, or Point of Rocks group, at which horizon there is at all ob- served points, extendino' over a large region, considerable unconformability by erosion of the lower strata of the Bitter Creek group upon the upper strata of the Point of Rooks group.^ Overlying the Point of Eocks group, considered the top of the Meso- zoic, are the following groups, that were held by Powell and White to represent the Eocene: (I) Bitter Creek, (II) Lower Green Eiver, (III) Upper Gieeu River, (IV) Bridger, (V) Browns Park. Bach group is fully characterized. The Eeport on Descriptive Geology, by Messrs. Arnold Hague and S. F. Emmons, of the U. S. Geological Exploration of the Fortieth Par- allel, appeared in 1877. In this work the term Lignitic is replaced by that of Laramie, which, however, was first used on advance sheets of the atlas, map 1, that appeared in 1875. The deposits of that formation are referred to the Cretaceous. The terms (I) Vermilion Creek, (II) Green Eiver, (III) Bridger, (IV) Uinta are employed for the overlying hori- zons, which are considered Eocene. 'Localities in Utah, Wyoming, and Xevada are mentioned and described. Concerning the taxonomy of the lignitic deposits of the interior, Prof. Marsh says, in hi^ vice-presidential address delivered before the American Association for the Advancement of Science in 1877 : The boundary line between the Cretaceous and Tertiary in the region of the Rocky Mounta.ins has been much in dispute during the last few years, mainly in consequence of the uncertain geological bearings of the fossil plants found near this horizon. The accompanying invertebrate fossils have thrown little light on the question, which is essentially whether the great lignite series of the west is uppermost Cretaceous or lowest Eocene. The evidence of the numerous vertebrate remains is, in my judg- ment, decisive and in favor of the former view. The higher vertebrate life of the Tertiary is discussed at length and in the table appended the Eocene is separated into four divisions. (I) Ooryphodon beds. (II) " Green Eiver beds." (Ill) Dinoceras beds. (IV) Diplacodon beds. ' Op. oit., pp. 71, 72. 20p. oit., p. 87. 122 THE EOCENE. tBui-L.SS. In the Ninth Annual Report of the TJ. S. Geological and Geographical Survey of the Territories for 1875 (published in 1877), Mr. F. M. End- lich describes the Puerco marls, together with the " Post-Cretaceous " beds of the Trinidad region. The volume upon Paleontology of the final reports of the U. S. Geo- graphical Surveys West of the One hundredth Meridian contains de- scriptions of Eocene invertebrate fossils by Dr. White, and vertebrate fossils by Prof. Cope. The latter characterizes the Puerco marls at con- siderable length, which he states are overlain by sandstones and marls of the Wasatch Group. He says : The Puerco marls may belong to the Eocene series, in view of their strict conform- ahility with the superincumbent rocks of that age. But they may represent the Fort tJnioa or lignite beds of the Upper Missouri, some of whose strata they resemble in color and consistence.' The same year Dr. 0. A. White published the first of his " Paleon- tological Papers " in the Bulletin of the U. S. Geological and Geograph- ical Survey of the Territories. The late Mesozoic and Oenozoic fauna are chiefly described in these contributions. In No. 3 a table of the dif- erent groups is given, in which the term post- Cretaceous is suggested to include the Laramie of King, together wiCh the lower portion of the Wasatch. In this table the Judith River beds are correlated with the Laramie and the Port Union with the Wasatch. After showing that a few forms of Inoceramus at a doubtful horizon of the Laramie and a single species of Odoutobasis, considered by Meek a genus character- istic of the Cretaceous, afford the only invertebrate evidence for the Mesozoic age of the lignitic deposits, he maintains that many forms show a marked similarity to Wasatch species. In this connection he says: It is in view of the facts here stated, and also because I believe that a proper in- terpretation of them shows the strata of the Laramie group and the base of the Wa- satch to be of later date than any others that have hitherto been referred to the Cre- taceons period, and also earlier than the Eocene epoch, that I have decided to desig- nate those strata as post-Cr6taceou8, at least provisionally.^ In the Tenth Annual Report of the TJ. S. Geological and Geograph- ical Survey of the Territories for 1876 (published in 1878) Dr. White presents a "table of correlated geaeral sections," in which the Laramie group' is made equivalent to the Lignitic group of Meek and Hayden, and the Laramie group of King, while it includes all of the Point of Rocks group of Powell, together with the lower portions of the Bitter Creek group of the last-named author. The remainder of the Bitter Creek series is shown to be commensurate with the Wasatch group estab- lished by Hayden, and later termed the Vermilion Creek group by King. The Green River and Bridger groups are exhibited as similarly delimited by the several authorities quoted, while the Uinta group equals the Plioceneof Hayden and Brown's Park group of Powell. The charac- ' Op. cit., p. 18- 2 VoL 3, p. 629. 8 The more general term, post^Cretaceous, is still retained. CLARK.) HISTORICAL SKETCH — INTERIOR. 123 teristics of each group are given at considerable length, together with type localities. Abandoning the position as to general unconformity between the Point of Rocks and Bitter dreek groups, as earlier maintained by Powell and himself, he says : The fact that this series (Laramie) passes insensibly into the Fox Hills group and into the Wasatch group above renders it difficult to fix upon a stratigraphioal plane of demarkation either for its base or summit. I have therefore decided to regard this group as essentially a brackish-water one, referring all strata below that con- tain any marine Cretaceous invertebrate forms to the Fox Hills group, beginning this series with those strata that contain brackish and fresh water forms, and ending- it above with those strata in which the brackish-water forms finally cease. Thus defined, the whole series seems to form one natural paleontologioal group, as well as to be a sufficiently distinct stratigraphioal one, for which I have adopted the name of Laramie group of King. * * * i believe that, upon the evidence of inverte- brate paleontology, the Fox Hills group is later than the latest Cretaceous strata of Europe, and I therefore regard the Laramie group as occupying transitional ground between the well marked Cretaceous and Tertiary groups ; but the opinion is only tentatively held until further facts are.obtained.' In the fourth volume of the Bulletin of the U. S. Geological and Geographical Survey of the Territories, published in 1878, Dr. White contributes three more " Paleontological Papers " (6, 7 and 8), in which the invertebrate fauna of the Laramie is discussed. In the second of these papers the Laramie group is given a much wider significance than hitherto. He says: The term Laramie group is here used to include all the strata between the Fox Hills group of the Cretaceous period beneath, and the Wasatch group (= Vermilion Creek group of King) of the Tertiary period above. That is, it includes, as either subordi- nate groups or regional divisions, both the Judith River and Fort Union series of the Upper Missouii River, the Lignite series east of the Rocky Mountains in Colorado, the Bitter Creek series of southern Wyoming and the adjacent parts of Colorado, and also the Bear River Estuary beds, together with the Evanston coal series of the valley of Bear River and adjacent parts of Utah. Strata of this great Laramie group are known to exist in other large and widely separated districts of the western por- tion of the national domain.^ Concerning the stratigraphioal relations of the series of deposits over- lying the Laramie in the Green Eiver Basin, he says : In the great region now drained by the Green River there are three well marked groups of strata that come in their order above the Laramie group, and which all agree in refer- ring to the Tertiary period. These are the Wasatch , Green River, and Bridger groups, named in ascending order. The Wasatch group is the lowest of a series of three fresh- water Tertiary groups, all of which are intimately connected, not only by an evident continuity of sedimentation throughout, but also by the passage of a portion of the molluscan species from one group-up into the next above. Not only were the three groups, aggregating more than a mile in thickness, evidently produced by a continu- ous sedimentation, but it seems equally evident that it was likewise uninterrupted between the Laramie and Wasatch epochs, although there was then a change from brackish to fresh waters and a, consequent change of all the species of invetebrates inhabiting those waters. 'Op.oit, p.33. 'Op.cit., p.721. 124 THE EOCENE. _ [bull. 83. The seventh volume of the Fiual Reports of the U. S. Geological Survey of the Territories is by Mr. Leo Lesquereux on " Tertiary Flora." lu this exhaustive treatise the author gives a full expression, of his views upon the Laramie group, which he. still holds to be Tertiary. The same year Mr. Clarence King published volume i (Systematic Geology) of the U. S. Geological Exploration of the Fortieth Parallel. In this report the views expressed by Messrs. Hague and Emmons in volume II (Descriptive Geology) are more fully presented. The Lara- mie is held to be Cretaceous and the Eocene Tertiary is divided into (I) Vermilion Creek group, (II) Green Eiver group, (III) Bridger group, (IV) Uinta group. These different divisions are individually charac- terized at considerable length. The Fort Union beds are held to be Miocene, and the northward extension of the White Eiver group of Nebraska. He states that unconformities separate the Laramie and Vermilion Creek deposits as well as the members of the Eocene series themselves. Vol. 5 of the Bulletin of the U. S. Geological Surv..ey of the Terri- tories contains an important article by Cope on " The Relations of the Horizons of Extia'ct Vertebrata of Europe and North America." In this paper the various groups of the American Eocene are compared with those of Europe upon the evidence afforded by the vertebrates. Concerning the Laramie he says that " its necessary position is between the Tertiary and Cretaceous, but on the Cretaceous side of the bound- ary,"' though later than the latest horizon of the French Cretaceous. According to Cope the post-Cretaceous embraces both Laramie and Puerco,the former commensurate with the Judith liiver and Fort Uniou deposits. The same volume contains an article by Peale on " The Laramie Group of Western Wyoming and Adjacent Regions." The Eleventh Annual Report of the U. S. Geological and Geograph- ical Survey of the Territories for 1877 (published in 1879) contains an article 'by Endlich upon the geology of the Sweetwater region. The Laramie group is assigned to the post-Cretaceous. The Sweetwater group is placed above the Bridger group, which, with the Green River group, are considered Miocene. The Wasatch group is alone referred to the Eocene. ^ Dr. White presents a most valuable contribution in the same volume, based upon much enlarged collections of invertebrate fossils that had been made by him from the Laramie and later groups during the pre- vious field season. He believes in " the unity of all the principal brackish-water deposits hitherto known in the western Territories, and * . * * their recognition as a comprehensive group of strata under the name of the Laramie group, which represents a great period in geological time, and especially such in the geological history of North America."^ After admitting the Cretaceous aspect of the ver- ' Op. cit., pp. 38, 39. ' Op. Oit., p. 252. CLAEK.] HISTORICAL SKETCH INTERIOR. 125 tebrate fauna of the Laramie on the one hand and the Tertiary aspect of the flora on the other, he states that the invertebrate fauna is " silent on the subject" of the taxonomj^ of the deposits. Referring to the appearance of niammalia in great variety of forms in the beds immediately overlying the Laramie, he says : Such suddenness of introduction malceB it almost certain thati it was caused by the removal of some physical barrier, so that ground whicLi was before potentially Ter- tiary became so by actual faunal ocoupimcy. In other words, it seems certain that these Tertiary mammalian types were evolved in some other region before the close of the Laramie period, where they existed contemporaneously with at least the later Laramie Dinosaurians of Cretaceous types, and that the barrier which separated the faunae was removed by some one of the various movements connected with the evo- lution of the continent. The climate and other physical conditions which were essential to the existence of the Dinosaurians of the Laramie period having evidently been continued into the Tertiary enochs that are represented by the Wasatch, Green River, and Bridger groups, they might doubtless have continued their existence through those epochs as well as through the Laramie period but for the irruption of the mammalian horde, to which they probably soon succumbed in an unequal strug- gle for existence.' The same volume contains a " Report'ou the Geology of the Green Eiver District," by Dr. A. C. Peale, in which the Laramie is referred to the post-Cretaceous, the Wasatch, Green River, and Bridger groups to the Tertiary, the two latter to the Miocene. Detailed descriptions are given of these various groups in the area investigated. In the American Naturalist for 1879 Prof Cope ^ describes " The Amyzon Tertiary Beds" of Osino and Elko, Nevada. The following year the same writer,^ in the Proceedings of the Amer- ican Philosophical Society, again refers to the Amyzon beds, and also ' describes the " Manti " beds of Utah. The latter deposits are further characterized in the American Naturalist ■• of that year. The sixth volume of the Bulletin of the TJ. S. Geological and Geo- graphical Survey of the Territories, published in 1882, has two impor- tant contributions upon the Eocene ; the first by Prof. Cope, " On the Vertebrata of the Wind River Eocene Beds of Wyoming," the second by Prof. Scudder on " The Tertiary Lake Basin of Florissant, Colorado, between South and Hayden Parks." The Twelfth Annual Report of the U. S. Geological and Geograph- ical Survey of the Territories for 1878 (published in 1883) contains further contributions by Dr. White on the Laramie and later groups, with descriptions of many new species. In the same volume is a report by St. John on the geology of the Wind River district. The character of the Wind River Eocene. and its relations to the other deposits are stated. A paper upon the " Tertiary Lake Basin at Florissant, Colorado," by Dr. Scudder, appears in the same report, reprinted with additions and alterations from the Bulletin. ' Op. cit., p. 265. 3 xm. Phil. Soc, Proc, vol. 19, 1880, p. 60-62. « Am. Nat., vol. 13, 1879, p. 332. ■• Am. Nat., vol. 14, 1880, pp. 303, 304. 126 THE EOCENE. (bull. 83. In the Second Annual Eeport of the TJ. S. Geological Survey, Gapt. C. E. Button contributes a paper upon " The Physical Geology of the Grand Canon District," in which he states that the Lower Eocene only is represented in that region. To the north, first the Middle Eocene, and then the Upper Eocene appear, while the entire series becomes represented as the Uinta Mountains are approached. He thinks the Middle and Upper Eocene were never deposited in the Grand Caiion country. Similar conclusions are maintained by the same writer in Monograph II of the U. S. Geological Survey, entitled " The Tertiary History of the Grand Canon District." In the American Naturalist for 1882 Prof. Cope^ contributed an im- portant paper on '' The Tertiary Formations of the Central Eegioa, of the United States." In this article the leading characteristics of the Puerco, Wasatch, Bridger, and Uinta groups are presented. In an article in the Proceedings of the American Philosophical So- ciety, a "Synopsis of the Veitebrata of the Puerco Eocene Epoch "^ is given by the same writer. Some points of difference shown in the Puerco deposits from true Eocene strata are stated. The Third Annual Eeport of the U. S. Geological Survey, published in 1883, contains "A Eeview of the Nonmarine Fossil Mollusca of North America," by Dr. White. In this paper Dr. White reiterates his former statements as to the transitional position of the Laramie group. He says : Geologists are not agreed as to whether this great group should be referred to the Tertiary or Cretaceous period, some contending for the former and some for the lat- ter reference. The truth appears to lie between the two opinions, and I have else- where presented reasons for regarding this group as occupying a transitional position between the Cretaceous and Tertiary, * * » and therefore as representing a period partaking of both the Mesozoic and Cenozoic ages.^ Concerning the extent of the Laramie he says : Tlie " Judith River group," "Fort Union group," '' juignitic group," " Bitter Creek Coal series," " Point of Rocks group,'' and " Bear River Estuary beds " are all parts of the great Laramie group.'' The position to be assigned to the overlying deposits is thus stated by Dr. White : The "Wasatch group," "Vermilion Creek group," and "Bitter Creek group" are regarded as at least approximately equivaleut strata, constituting the oldest member of the purely fresh-water Eocene Tertiary series of deposits in the West. The Green River and Bridger groups are respectively the second and third members of that fresh-water Eocene series. The Wind River group of Wyoming is regarded as of Eocene age.^ The same year there appeared in the American Journal of Science a paper by Dr. White,* entitled " Late Observations concerning the Mol- ' Am. Nat., vol. 16, 1882, pp. 177-195. « Op. oit, pp. 415, 416. 2 Am. Phil. Soc, Proc, vol. 20, 1882, pp. 461-470. = Op. oit., p, 416. 3 Op. oit., pp. 414-416. « Am.- Jour. Soi., 3d sor., vol. 25, 1883, pp. 207-^09. CLARK.J HISTORICAL SKETCH — INTERIOR. 127 luscan Fauna and Geographical Extent of the Laramie Group," in which he says : That any true Laramie strata ever alternate with those of the Fox Hills group or any other marine Cretaceous group, or that any true marine fossils were ever collected from any strata of the Laramie group, I can not admit. I regard all such statements as a result of a misunderstanding of the stratigraphioal geology of the region in which such observations are said to have been made. In volume vm of the Final Eeports of the U. S. Geological Survey of the Territories upon " Cretaceous and Tertiary Flora," published in 1883, the author, Mr. Leo Lesquereux, still maintains the Eocene age of the Laramie group. In an article in the Neues Jahrbuch fiir Mineralogie, Geologic, and Palaeontologie for 1884, M. Neumayr places the Laramie group in a parallel position with the Intertrappean beds of the Deccan in Hindo- stan, and between the Cretaceous and the Eocene. Lists of similar fossil plants from the two areas are given. "A Eeview of the Fossil Ostreidse of North America," by Dr. White, appears in the Fourth Annual Report of the U. S. Geological Survey, published in 1884. In this article the author compares the conditions of the Laramie Sea to the Caspian, in which the waters are fresher than those of the ocean. Prof. Cope^ presents a short paper on " The Relations of the Puerco and Laramie Deposits " in the American Naturalist for 1885, in which he says : Some writers having suspected the identy of the formations above named and the consequences which follow that the Puerco mammalian fauna was contemporary with the dinosaurian fauna of the Laramie age, the following observations on their stratigraphio relations are now given. At the locality where best developed the Puerco beds have a thickness of about 850 feet and contain mammalia to the base. The Laramie beds succeed downward conformably, it is thought by Mr. Baldwin, and have a thickness of 2,000 feet at Animas City, New Mexico. They rest on Fox Hills marine Cretaceous of less thickness. Concerning the taxonomy of the Puerco group. Prof. Cope now re- cedes from his formerly expressed opinion that the beds are Eocene, and maintains their Cretaceous affinity on account of "the absence of Perissodactyla and Rodentia, and of course of mammalian orders not found below the Miocene. * * * and in the constitution of the mammalian fauna by Oondylarthra, Bunotheria, and Marsupialia." The Puerco group is placed in the post Cretaceous, which " as a whole may be ultimately distinguished from the Tertiary by these peculiarities [given above], together with the reptilian genus Champsosaurus." In a presidential address upon " The Application of Biology to Geo- logical History," delivered by Dr. White'* at the Fifth Anniversary Meet- ing of the Biological Society of Washington, January 24, 1885, the author reviews briefly the conflicting nature of the evidence afforded > Am. Nat., vol. 19, 1885, p. 985. » Washington Biol. Soc, Proc, vol. 3, 1886, pp. 1-20. 128 THE EOCENE. [bull. 83. by the vertebrate and invertebrate faunas and the flora of the Laramie group. In the Fifth Annual Eeport of the U. S. Geological Survey, and later in Monograph X of the same, Prof. Marsh divides the Eocene into four groups, basing his divisions upon the vertebrate fossils : (I) Coryphodon [Wasatch] beds, (II) Heliobatis [Green EiverJ beds, (III) Dinoceras [BridgerJ beds, (lY) Diplacodon [Uinta] beds. The most exhaustive treatise upon the literature ofthe Laramie is to be found in a " Synopsis of the Flora of the Laramie Group," b^ Prof. L. F. Ward, that appeared in the Sixth Annual Report of the U. S. Geological Survey, published in 1885. It has afforded an outline for the present chapter, so far as the history of opinion upon the Laramie is concerned. This important paper presents us with the latest views that paleobotany has to offer upon the interesting problems presented by the Laramie formation. The writer says : The discussions with regard to the age of the Laramie group, which have been rapidly passed iu review, have perhaps sufficiently shown that it is impossible to refer that group either to the Cretaceous or the Tertiary, and in so doing harmonize all the facts that the group presents with those iu conformity with which other de- posits in other countries of the world have been so referred ; but they have also suf- ficiently shown that this is not the fault of the investigators, but, so to speak, of the facts, and that the real disagreement is in the organic forms and the nature of the deposits, so that omniscience itself could never harmonize them with all kinds of forms and deposits in all parts of the world. It is, therefore futile, and indeed puerile, longer lo discuss this question, and we may well afford to dismiss it alto- gether and settle down to the more serious study of the real problems which still lie before us.' In this report Prof. Ward shows that over 20 species "of plants are common to the Laramie and Green River groups. The " Eelation of the Laramie Molluscan and Fresh- water Eocene Faunas " is discussed by Dr. White in Bulletin 34 of the TJ. S. Geolog- ical Survey, published iu 1886. In this report Dr. White states that there is no* known case of a marine Cretaceous form having lived on into Laramie time, though it is probable that some estuarine species may have done so. He mentions the persistence, however, of Laramie fresh-water forms into the Wasatch. The Bear Eiver Estuary beds are placed intermediate between the Cretaceous and Eocene, and prob- ably synchronous with the Laramie, though possessing a wholly dif- ferent fauna. The Puerco beds are shown to possess an entirely differ- ent vertebrate fauna from the Laramie below and the Wasatch above, with both of which they are conformable. The author thinks they may represent the lower portion of the Wasatch of Utah. The upper portion of the Fort Union beds is provisionally correlated with the base of the Wasatch. In Bulletin 37 of the U. S. Geological Survey, published in 1887, Mr. 'Op.cit., p.435. OLAKK.] HISTORICAL SKETCH- — INTEEIOE. ' 129 L. F. Ward discusses the " Types of the Laramie Flora," in which new data are added to the earlier " Synopsis " that appeared in the Sixth Annual Eeport. The same year Dr. White published in the American Journal of Sci- ence an important paper' entitled "On the Inter- Relation of Contem- poraneous Fossil Faunas and Floras." In this article he says : " That faunas and floras of Cretaceous and Tertiary types should have existed contemporaneously is not strange, for a similar diversity now exists as regards the living faunas and floras of different parts of the world." The sudden appearance of so many various mammalian types he main- tains was due to " the removal from time to time of certain physical barriers which previously restricted the dispersion of those faunas." He considers that sedimentation from " the Laramie to the Bridger groups inclusive was at no time everywhere interrupted," and thus there is an "unbroken continuity of invertebrate and plant life." A year later an article by the same writer " On the Eelation of the Laramie Group to Earlier and Later Formations "^ contains reference to the Laramie of Texas and its position as regards the marine Eocene of theTGrulf States. The author inclines to the view that the coal-bearing strata of the Laramie are the equivalent in part at least of the " North- ern Lignitic " of Hilgard. In the American N'aturalist for 1887' and American Geologist for 1888 * Prof. Cope presents reports upon the " Mesozoic and Cenozoic Realms of the Interior of I^Torth America." In each of these papers the Laramie and Puerco are referred to the " Post-Oretacic system," while the Eocene is divided into the (I) Wasatch, (II) Wind Eiver, (III) Bridger, (IV) Diplacodon beds, or Uinta. Two other formations that he considers " contemporary with one or more of these " are the Amy- zon beds and the Green Eiver shales. The strati graphical relations of certain deposits in the vicinity of Denver that had hitherto been considered Laramie are discussed by Mr. George H, Eldridge' and Dr. Whitman Cross^ in the Proceedings of the Colorado Scientific Society for 1888. These beds are readily divided on both lithological and stratigraphical grounds into two groups ; the lower called the Arapaho,'' unconformable to the Laramie ; the upper, the Denver, unconformable to the Arapaho. The more detailed evidence for their separation from the Laramie will be given later. In the Eighth Annual Eeport of the U. S. Geological Survey, pub- lished in 1889, Prof. Ward contributes a paper on " The Geographical ' Am. Jour. Sci., 3d ser., vol. 33, 1887, pp. 364-374'. = Ibid., Tol. 35, 1888, pp. 432-438. 'Am. Nat., vol. 21, 1887, pp. 445-462. «Am. Geologist, vol. 2, 1888, pp. 265-267, 285-299. 'The Mining Industry, vol. 3, 1888, No. 3, pp. 24, 25 ; No. 4, pp. 33-35 ; No. 5, pp. 44-45, and Colorado Soi. Soc, Proc, vol. 3, 1888, pp. 86^118. « Colorado Sci. Soc, Proc, vol. 3, 1888, pp. 119-133. Am. Jour. Sci., 3d ser., vol. 37, 1889, pp. 261-282. 'In earlier articles called the " Willow Creek beds." Bull. 83 9 130 THE EOCENE. [bull. 83. Distribution of Fossil Plants." The Eocene localities throughout the Interior region where fossil leaves have been found are cited and the literature of the subject freely quoted. A map showing the distribu- tion of fossil plants in the United States is added. The vice presidential address of Dr. White' at the Toronto meeting of the American Association for the Advancement of Science is a most valuable contribution to the present discussion of the application of the European scheme of classification to the strata of the North Ameri- can continent. That minute correlation is impracticable is clearly shown. The Laramie group is discussed in the light of recently ac- quired data. In the Bulletin of the Geological Society of America, volume i, pub- lished in 1890, is an abstract of a paper upon " The Laramie Group," presented by Prof. J. S. Newberry. In this article Dr. Newberry de- clares " that the floras of the Laramie and Fort Union groups are totally distinct, and that these formations should be referred to differ- ent geological systems — the Fort Union to the Tertiary, the Laramie to the Cretaceous." ^ ■ In the discussion that follows he says : " In -my judgment the Laramie is the top of the Cretaceous system. I do not know why it should be called post-Cretaceous. It is true there must be somewhere connecting liulss between the Cretaceous and the Ter- tiary, » » * but I know of no evidence that the Laramie is such a passage bed." Dr. Newberry maintains "the interlocking of the Lara- mie and Fox Hills formations from several localities." In the discus- sion Prof. Ward admits that the floras of the Fort Union beds and the Laramie of Colorado, Wyoming, and New Mexico "are not identical — they are very different," yet he maintains that there are eight or ten identical Species; not one, as stated by Dr. Newberry. Further he says : " Whatever may be true in regard to a difference of age— and it seems to me that the two must go together — I am quite satisfied that a warmer climate prevailed during the period of the deposition of the Wyoming and Colorado beds than that which prevailed during the dep- osition of the Fort Union beds." An important contribution to the structural relations of the Interior Eocene was presejited at the same meeting by S. F. Emmons' in a paper on the " Orographic Movements in the Rocky Mountains." The reader has doubtless observed that in the present chapter much more attention has been devoted to the Laramie and Puerco groups than to the later horizons. This has been rendered necessary on ac- count of the wide difference of opinion that has existed among those who have studied these groups and the much more extensive literature that has resulted therefrom. Where there has been practical agree- ment as to the interpretation of facts simple reference to the articles of importance has been deemed sufficient. For the reasons cited the lit- ' Am. Assoc. Ad. Soi., Proc, vol. 38, 1889, pp. 205-226. ' Op cit., p. 525. ' Geol. Soo. America, Bnll. vol. 1, 1890, pp. 245-286. CLAKK.1 HISTORY OP EOCENE DEPOSITION. 131 erature of the Interior region has thus required fuller treatment than that of either the Atlantic and Gulf Coast or Pacific Coast regions. STBATIGBAPHLCAL AND PALEONTOLOGIOAL CHARACTERISTIOS. QHNERAL BEMARES. Prom what has been stated in the previous pages, it is obvious that very diverse opinions have existed as to the delimitation of the Eo- cene of the Interior. Quite general unanimity prevails at the present time as to the position to be assigned to the boundary between the Eocene and the Ifeocene, while hardly two writers agree as to the line of demarcation between the Eocene and Cretaceous. This wide divergence of opinion among those who have had opportuni- ties for extensive observation may be found iu the use of different classes of facts and in the investigation of different areas. In the case of many writers stratigraphical data alone have been employed in the cousider- ation of the Eocene, while paleontological evidence has been for the most part ignored. Others, holding the stratigraphical relationship of the beds to be less important, essayed by the use of paleontological data to interpret the taxonomy of the deposits. Of the latter, two classes of investigators have been prominent, the one judging the evi- dence entirely from the standpoint of paleobotany, the other from that of vertebrate paleontology. As the development of the plants and animals in the Interior region has not been along the same parallel lines as in other areas, much confusion has resulted from an attempted cor- relation of the strata. By the vertebrate paleontologist much has been included within the Cretaceous that the paleobotanist has referred to the Eocene. Fortunately there appears, at the present time, a ten- dency to view the evidence in its entirety rather than to employ any single class of facts in determining the age of the various deposits. The physical changes that took place during and subsequent to the formation of the Eocene deposits have so fully determined the charac- ter of the strata that a brief statement of the more important is imper- ative. For the elucidation of these points geology is indebted to Dr. White, and, in the succeeding statement his ideas are largely followed. Previous to the opening of the Eocene period an open sea had long prevailed over the western Interior region, in which a series of argilla- ceous and arenaceous sediments of great thickness had accumulated. Throughout these deposits are found widely represented the typical marine forms of the Cretaceous. With the elevation of physical barriers to the south the salt waters become brackish, the previous types of marine life could no longer main- tain themselves within the area, and gave place to other forms better adapted to the changed habitat. Although the influence of these altered conditions is manifested in the aqueous fauna, the continental animal life of the previous age was able to maintain itself for a longer time. 132 THE EOCENE. [bull. 83 dinosaurian types, characteristic, of the Cretaceous, persisted till the close of the brackish- water period. With the still further increase of the physical barriers the brackish- water conditions were changed to fresh water ; in some cases the iu- vertebrate forms continued their existence, but on account of unknown causes a' marked change occurred in the vertebrate life. There was a sudden appearance of highly developed mammalian types that must have existed for a long time without the Interior region, and contempor- aueously with the dinosaurian fauna within the area. Whether, as has been suggested, the disappearance of certain barriers to their migration suddenly admitted the mammalia that in the struggle for existence soon overcame the reptilian fauna that had continued here to a later date than elsewhere will probably never be solved, but the explanation given affords a good working hypothesis. The great fresh-water lakes continued with successively diminished areas during the remainder of the Eocene period. With the advent of the Neocene an extensive region was again covered with fresh-water lakes which finally became/irained in the ordgraphic movements accom- panying the elevation of the Rocky Mountains. A few salt lates alone remain to mark their former extension. During late Tertiary and post-Tertiary times the great elevation that the Interior region received has admitted of extensive denuiiation throughout the area covered by Eocene strata. This, added to the arid climatic conditions prevailing widely throughout the territory, has afforded advantages for geological investigations not to be found in either the Atlantic and Gulf Coast or Pacific Coast regions. Largely on account of these facts the stratigraphy of the Interior Eocene has been more accurately determined than that of either of the regions previously described. Accordingly, a consideration of the Eocene of the Interior under geographical limitations may be dispensed with and the formation discussed under its various subdivisions. • LARAMIE GROUP. The strata of the Interior region, described under the name of the Laramie group, have been, for reasons already briefly cited, referred by some writers to the Cretaceous, by others to the Eocene. In the face of this conflicting evidence, and for reasons stated later, I have consid- ered that the Laramie strata are to be referred partly to the one hori- zon, partly to the other.' As the investigation of the deposits has thus far failed to reveal any satisfactory evidence as to the exact position of the dividing line, the entire series will be briefly outlined. The term Laramie was first employed by members of the U. S. Geo- logical Exploration of the Fortieth Parallel, and finds expression in Vol. I, Systematic Geology (1878), and Vol. II, Descriptive Geology (1877) of the reports of that organization. It had already appeared on ' This position has already been taken by Dr. C. A. Wjiite in aeTeral of Ms published writings. oiARKl LAKAMIE. 133. map 1 of the atlas, which was distributed in 1875. Hitherto the name' Lignitic group, early proposed by Dr. Hayden, had been the geueraliy aftcepted taxonomic term, though certain lignitic deposits, not cor- related with that formation, had, at the same time, received local names from the place of their occurrence. The Judith River beds, the Port Union beds, the Bear Eiver Estuary beds, etc., had beeu thus desig- nated by different writers and referred to various horizons iu the geo- logic column. The term post-Cretaceous, suggested by Dr. White,' found acceptance for a time, but has been now for the most part aban- doned, as it soon was by himself. The territory in which the Laramie group is represented covers a wide area along the easteru flanli of the Rocky Mountains, extending from the region of its typical development in Wyoming and Colorado northward across Montana into Canada, and southward across New Mexico and Texas into Mexico. Prom the Rocky Mountains it extends eastward to the Great Plains. To the west of the Rocky Mountains it is found somewhat less widely represented, occuring in Wyoming, Utah, Colorado, and Kew Mexico. The deposits are chiefly sandstones, shales, and lignites. King has estimated the thickness of the strata on the easteru flank of the Rooky Mountains in Colorado at 1,500 feet, while in southwestern Wyoming the same observer has placed the thickness at 5,000 feet. Over wide areas the strata lie approximately horizontal, though due to the great orographic movements that have taken place in the Inte- rior region the beds are often highly tilted. The Laramie is found rest- ing conformably upon the next older or Pox Hill group, of whose Creta- ceous age no doubts have been expressed. Overlying the Laramie con- formably at some points, though unconformably at others, is the Wasatch group, of whose Eocene age similar unanimity of opinion is found. The question that presents itself then is whether the Laramie is to be placed with the Cretaceous on the one side or with the Eocene on the other of the Mesozoic-Cenozoic dividing line. We have found that the evidence presented by vertebrate paleontol- ogy unhestitatingly points to the Cretaceous, from the presence of Dinosauria, which elsewhere are not found later than the closing epoch of the Mesozoic, In fact the u^jpermost beds of the lignitic series have afforded dinosaurian remains. Cope, however, holds to the term " post- Cretacic" for the Laramie and Puerco groups, thus conceding a later age to the lignitic series of the West than many vertebrate paleontolo- gists. The weight of authority of the paleobotanists has afforded the chief support to the Eocene position. The types of plant life are decidedly late and several are identical or closely allied to living forms. More- over, the Tertiary floras of other parts of the world are closely parallel to that of the Laramie. So late is the general aspect of the flora that ' tr. S. Geol. Sarv. of the Territories, Bull. , vol. 3, 1877, p. 608 134 ' THE EOCENE. (BUii.83. many, including so distinguished a paleobotanist as Heer, have held the deposits to be Miocene. The evidence afforded by invertebrate paleontology, upon which 'so great confidence is usually placed for purposes of correlation, is of little value. The conditions that obtained during the accumulatioa of the brackish-water Laramie deposits wore such as to greatly change the invertebrate fauna that had hitherto found a peculiarly favorable habitat in the marine waters of pre-Laramie time. It seems not im- probable that outside the barriers of the Laramie sea the marine forms still continued for a time their existence contemporaneously with the brackish-water species. The latter, on the other hand, ceased to exist as the waters became fresh, thougli in certain areas brackish and fresh water conditions prevailed at the same time, so that the fresh-water species of the Laramie continued their existence into the Wasatch period. The brackish- water types of the Laramie are not distinctive of the age of the deposits. The Cretaceous character of the marine in- vertebrates of the i^revious period has never been doubted, while the fresh-water forms of the succeeding period have been for the most part considered Tertiary. The brackish-water species might be either Cretaceous or Eocene, and are doubtless both. As to the supposed incongruity of evidence afforded by the verte- brates aud plants, it seems most fully to coincide with the present method of geological reasoning to suppose that the couditions were favorable for the continued existence of the Mesozoic dinosaurian forms to a later period here than in other areas. The supposition that has been advanced that physical barriers precluded the entrance into the area of the mammalian fauna, that from its highly developed state in the succeeding period must have, before the close of the Laramie, com- menced its existence outside, seems fully to accord with the facts. That the plants may have here presented forms that have elsewhere not been known till a later epoch is not improbable when we consider that the development of fossil faunas and floras have not been in many other portions of the globe always along identical lines. From the evidence above presented there seems no incongruity in supposing that in the Laramie group we have represented the closing events of Cretaceous and the opening epoch of the E: cene. Concerning the approximately synchronous age of most of the lignitic strata of the Interior region, there is a rather general agreement of opinion. However, the lignitic strata of certain local areas, although held by many geologists to be identical with the typical Laramie, are by others thought to be of widely different age. Among these local deposits, in regard to which considerable discussion has hitherto taken place, may be mentioned the Fort Union beds of Montana, the Bear Eiver Estuary beds of Utah, the Arapaho and Denver beds of Col- orado. ' CLARK.] FORT UNION — AEAPAHO. 135 PORT UNION BEDS. The deposits in the vicinity of Fort Union, on the Missouri Eiver, were the first llgnltic strata to be scientifically examined, having been, before 1860, explored by Dr. Hayden. During the progress of the U. S. Geological and Geographical Survey of the Territories frequent in- vestigations of the region were made and the results published in the various reports of that organization. Although tbe same discussions as to the Cretaceous or Tertiary age of the deposits have been maintained here as in the more southern rep- resentatives of the Laramie, there has been a much more general will- ingness to concede the Tertiary age of the former than of the latter. Prof. Ward,^ it is true, states thai there would be " no inconsistency in assigning to the Fort Union an age as ancient as the closing period of the Cretaceous system." Prof. Newberry,^ who has for many years studied the Laramie and Fort Union floras, thinks that the two forma- tions should be referred to different horizons, the former to the Creta- ceous, the latter to the Tertiary. He says : The Fort Union flora may be distinguished from that of the Laramie at a glance by its abundant species of Viburnum, Popiilus, Platanus, and Corylus, and it in- cludes several species now living, such as Onoclea aensibilie, Taxodium distiohum, and two hazels *hioh can not be distinguished by their leaves from Corylus rostrata and C. Americana. Prof. Ward, discussing these statements of Dr. Newberry, says " that although the difference in flora exists," yet the Laramie and Fort Union " must go together," and offers in explanation "that possibly the latitude, taken in connection with a different topography, such as may have existed in the two regions, might account for the great differ- ence in the floras." Prof. Ward further gives a list of 8 identical species from the Laramie and Fort Union groups. Dr. White, from a study of the moUuscan fauna, likewise asserts the identity of the Fort Union beds with the Laramie group. BEAR RIVER ESTUARY BEDS. The lignitic strata upon the Bear Eiver in western Wyoming and northwestern Utah have greatly puzzled the stratigraphical geologist and paleontologist. The deposits are unconformably overlain by the strata of the Wasatch group, while the fossils show little similarity with those of the typical Laramie from other regions. From what is known of the beds, their position, if they are to be assigned to the Laramie at all, is undoubtedly low down in the series. They will probably be found to be of earlier age. ARAPAHO BEDS. The stratigraphical relations of the Arapaho beds, so named from Arapaho County in eastern-central Colorado, where the formation is > Geol. Soo. America, Bull., vol. 1, 1890, p. 530. "Ibid., pp. 524-627. 136 THE EOCENE. (bull. 83. best exhibited, have beeu investigated by Mr. George H. Eldridge,^ of the U. S. Geological Survey. The strata of this horizon are confined to a comparatively small area on the eastern flanks of the Rocky Mountains in the vicinity of Denver. The formation "is composed of a basal member of conglomerate, or gritty sandstone, according to its distance from the foot-hills, with an overlyingzone of gray argillaceous or arenaceous shales containing len- ticular masses of hard quartzose sandstone with an occasional ironstone ; where confined between under and overlying groups, It has a thickness varying between 600 and 1,200 feet. The conglomerate at its base has a thickness over a greater portion of the field of about 200 feet, though this may become the bulk of the formation, as in its type locality, or may decrease to the merest edge, as at its northern limit. It is ex- tremely characteristic, containing as it does pebbles derived from every formation that lies below it in the Denver field, but also from others lying far beyond, especially the Carboniferous." Although the angle of dip is not materially different from the Laramie in some localities, " it is not uncommon to meet with the younger formation resting in the eroding hollows of the older, and containing rolled clays, ironstones, and pieces of sandstone evidently derived from the underlying beds." The Arapaho beds have afforded dinosaurian remains 'that show their paleontological affinity to the true Laramie, with which they have generally been confounded. The marked stratigraphical separation above cited, together with the fact that the fossils, hitherto relied upon to associate this and the suc- ceeding group with the Laramie, have been collected without reference to the horizons represented, afford us no definite evidence that the Ar- apho formation should be allied directly with the Laramie. When care- ful collections are made from the diffei'ent horizons of what in the past has been termed Laramie, wider differences in fauna aud flora may be shown to exist than have hitherto been recognized. Whether the Arapaho group then should be considered as represent- ing a later epoch in the Laramie proper or separated entirely from it is a matter of considerable doubt. DENVER BEDS. The Denver beds, so called by Dr. Whitman Oross,^ are confined to a limited area in the vicinity of Denver, Colorado, where they are found to occupy a basin within the Arapaho formation. The strata are composed very largely of andesitic materials in which both basic and acid types appear. In general the lower beds of the group are fine grained though very variable in texture, while the upper are represented by coarse conglomerates in which a considerable ad- mixture of materials derived from the Archean and sedimentary rocks is found. ' Colorado Soi. Soc, Proc, vol. 3, pt 1, pp. 97, 98, 100-102, 1888. = Am. Jour. Soi., 3d ser., vol. 37, 1889, pp. 261-282. CLARK.] DENVER — PUERCO. 137 In explaining the origin of tliese andesitic materials Dr. Orosa' says : There is no known source which can be assigned with plausibility for any one of the many andesitic types represented in the Denver strata. * * * The andesitic masses which furnished the materials for the lower part of the Denver sediments vrere so situated as to effectually prevent the access of all Archean and sedimentary debris to the lake of that epoch. That is to say, in the interval between the Ara- paho and Denver epochs there was an outpouring of andesitic lavas completely cov- ering the Archean and sedimentary rocks of the area afterward contiguous to the Denver lake. When sedimentation began again only eruptive debris could appear in the deposits until erosion and general degradation had laid bare, here and there, small areas of granite, of gneiss or of sandstone. WJthin these deposits is found an extensive fossil flora the true char- acter of which is but imperfectly known. Hitherto the specimens col; lected from this formation have not been separated from those obtained from the underlying Laramie deposits, so that great co'nfusion prevails. So far as they can be distinguished, many forms not found elsewhere occur. In the vertebrate fauna the presence of Dinosaurs is interesting, show- ing that they were able to " survive the changes of condition attending a period of folding and another period of great volcanic activity." The same difficulty in an attempted correlation of the Denver beds is found as in that of the Arapaho beds. MIDDLE PARK BEDS. An occurrence in many particulars similar to the Denver formation is to be found iu Middle Park, Colorado, where a series of andesitic breccias and conglomerates, with interstratified sands bearing plant remains, rests unconformably upon the Cretaceous. This series is esti- mated by Marvine^ to reach 800 or 900 feet in maximum thickness. Overlying the andesitic beds are sandy shales, sandstones, and grits, chiefly of granitic origin, that in places are found unconformably rest- ing upon the Cretaceous. Seams of lignitic material and numerous fossil leaves are found scattered through the series. PUERCO BEDS. The Puerco beds, first described by Cope^ in the Annual Eeport of the U. S. Geographical Surveys west of the One Hundredth Meridian for 1875, were long considered by that writer to belong to the Tertiary, al- though later referred to the " post-Cretaceous.',' Endlich* regarded the beds as a subdivision of the Wasatch. The geographical extent of the Puercoj is limited to northwestern New Mexico and southwestern Colorado, where it is found resting upon the Laramie and in turn overlain by the Wasatch. ' Am. Jour. Sci., 3d 8er., vol. 37, 1889, p. 271. " TT. S. Geolj and Geog. Surv. of the Territories, Ann. Eep. for 1873, p. 160. ' Ann. Eep. of the Chief of Engineers for 1875, appendix: 44, p. 89. " F. S. Geol. Surv. of the Territories, Ann. Rep. for 1875, p. 189. 138 THE EOCENE. [bdil.SS. Lithologically it is characterized by sandstones and gray and green marls, the latter soapy in texture and giving a highly characteristic appearance to the country. At the point of its typical development, at the headwaters of the Puerco Elver, west of the Jemez and Naci- miento Mountains, in New Mexico, it reaches a thickness of outcrop of about 850 feet.' Cope' thus characterizes the faunal relations of the beds : The fauna of this horizon is well distinguished from that of the Laramie in the absence of the numerous Diuosauria of the latter, and the presence of numerous Placental Mammalia in the former. On these grounds I at first referred the for- mation to the Cenozoic. series, but further reflection induced- me to place it as now arranged. The reason is as follows : Although Placental Mammalia are not known otherwise from the Mesozoio beds, the other forms of the Puerco are especially Mesozoic in character. Such are theChoristodere Eeptilia and the Mulititubereulate Marsupialia, neither of which occur above, while both occur below the Puerco, the Multituberculata down to the Trias, inclusive. Then the Placentialia are entirely peculiar in the absence of the Diplarthra and of the Eodentia, orders always found .n the Cenozoic beds. Then the characters of the Condylarthra and Amblypoda and many of the Creodonta, whicli represent Tertiary types, are so peculiar that we are led to suspect that where the Cretacic Mammalia are fully known they can not differ widely from those of the Puerco. Concerning the stratigraphical position of this unique formation Dr. White' says: The lowest strata in which the remains of this fauna have yet been found closely coincide In position with the top of the Laramie group ; and they disappear sud- denly upon a certain higher horizon which seems to come within the basal portion of the Wasatch group. Moreover, the known area within which this Puerco fauna has been found is only a small part of that within which the Laramie and the Wasatch groups occur. That is, the Puerco fauna has not been recognized at the majority of the localities where the Wasatch has been found overlying the Laramie. In some of the latter cases the two formations have been found to be clearly connected, not only by strict conformity of the strata, but also by an iutermingling of their molluscan faunas ; and in none of them has any indications of a missing formation been ob- served. It will thus be observed that the relations of the Puerco beds to the Laramie and Wasatch in the area where- represented is peculiar and " appears to mark an epoch in the history of vertebrate life of North America of which the invertebrate and plant remains, and the strati- graphical conditions of the series of deposits in which they occur, give no indication." Whether the Puerco beds should be considered Cretaceous or Ter- tiary the evidence is as yet inconclusive, though it seems probable that they should be referred to the latter. If the upper portion of the Lar- amie may be considered such," the Puerco beds would necessarily be so interpreted, unless, perchance, they do not rest upon the latest horizon of the Laramie. 'Am. Nat., vol. 19, 1886, p. 985. 2'lbid., vol. 21, 1887,pp. 450, i61. » Am. Jour. Soi., 3(1 ser, , vol. 33, 1887, p. 368. CLABK.) WASATCH. 139 WASATCH GROUP. The Wasatch grouj}, so called from the Wasatch Mountains of Utah, upon the flanks of which deposits of this age are extensively developed, is fully characterized by Dr. Hayden in the various Annual Keports of the Geological Survey of the Territories. It is described by the mem- bers of the U. S. Geological Exploration of the Fortieth Parallel under the name of the Vermilion Creek group. The former terin is, however, generally employed and is here retained by the writer. The strata are found in four chief areas. The region of southwestern Wyoming and northwestern Utah has been most extensively explored and consists of reddish sandstones and marls that according to King reach 5,000 to 5,500 feet in thickness. in northwestern New Mexico a considerable tract of similar strata has been described by Cope, who estimates the thickness of the beds at 2,500 feet. Intermediate between these two areas in the San Pete Valley of central Utah Dr. White has further determined the presence of Wa- satch strata with a varied fresh-water molluscan fauna. In northwestern Wyoming, also, the Wasatch group has been identi- fied and the beds estimated to reach 4,000 feet in thickness. The Wasatch strata throughout much of their extent are conforma- ble to the Laramie, but in western Wyoming and eastern Utah a marked unconformity is exhibited. As previously mentioned, the taxonomic position of the lignitic beds of the Bear Eiver area is doubtful, so the existing unconformity may possess less interest when the deposits are more fully comprehended. The stratigraphical relations of the Wasatch and Laramie have been differently interpreted by White ' and King,^ the former considering that deposition was in part continuous during the Laramie and Wasatch periods, the latter that it was wholly inter- rupted. The fauna of the Wasatch presents a varied series of invertebrate forms, chiefly molluscan in character, and of a typical fresh-water hab- itus. Some few- are identical with species found in the fresh- water strata of the Laramie and others are found to persist into the later hor- izons of the Eocene. The vertebrate fauna is chiefly mammalian, and from the prevalence of the genus Coryphodon, Marsh has designated the Wasatch group the Coryphodon beds. Cope ' in characterizing the vertebrate life of the Wasatch states that it is marked by the " presence of Tseniodonta, Condylarthra, and Pauto- donta. Absence of Tillodonta, Dinocerata, Palseosyops, Hyrachyus, Amynodon, Achsenodon, Trilpopus, and suilline and selenodont Artio- dactyla." ' U. S. Geol. and Geog. Surv. of the Territoriba, Tenth Ann. Kept, for 1876, p. 35. ' U. S. Geol. Expl., 40th Parallel, toI. 1, Syatematic Geology, 1878, p. 353 et seq. » Am, Geologist, toI. 2, 1886, p. 287. 140 THE EOCENE. [bull. 83. GREEN RIVER GROUP. The Green Eiver shales have a much more contracted range than the deposits of the previous group and are confined m their typical de- velopment to the basin of the Green Eiver in southwestern Wyoming and western Colorado. Here ttiey reach a thickness of about 2,000 feet, and consist " of calcareous sands and slightly siliceous limestones which are overlaid by remarkable fissile calcareous shales."' The lower member is about 800 feet in thickness, the upper 1,200 feet. The coarse materials of the preceding period are not present, and in general the sedimentation denotes deep and quiet water. According to King the deposits rest unconformabty upon the Wasatch.^ The fauna of the Green Eiver group has quite a different character from that of the preceding or succeeding horizons, and consists chiefly of fishes, insects, and moUusks. The molluscau forms predominate in the lower division, while the fishes and insects are confined to the upper member of the series. A common molluscau genus is the Goniobasis that ranges widely throughout the Eocene. The vertebrate fauna, represented by vast numbers of very perfectly preserved individuals of a few species of fishes is, according to Marsh, characterized by the genus Heliobatis, and for that reason the Green River shales are des- ignated in his classification as the Heliobatis beds. The fish-bearing strata contain numerous remains of insects. The types of fish are characteristically Eocene, and in the case of several genera begin to appear in the Wasatch, while two genera range from the latter into the Bridger. WIND RIVER GROUP. Although the beds occupying the upper basin of the Wind Eiver and described by Hayden as the Wind Eiver group in the various publica- tions of the TJ. S. Geological Survey of the Territories do not afford, upon stratigraphical grounds, a basis for a satisfactory correlation with any of the divisions of the southwestern Wyoming area, yet for reasons to be presently mentioned it is generally conceded that the Wind Eiver group represents the Green Eiver group, although Scott^ would con- sider it Lower Bridger in age. Hayden states that the deposits consist of " light gray and ash-col- ored sandgtones, with more or less argillaceous layers," and that " the strata are most beautifully variegated with various shades of pink or brick-red color, so that they sometimes remind one of the Jura-Trias red beds." The deposits extend along the Wiud Eiver basin about 100 miles, and are from 1 to 5 miles in width. The aggregate thickness of the strata is estimated at 1,000 feet or more. Cope* states that " the vertebrate fauna consists of the mammalian ' tr. S. GooL Expl. 40tli Parallel, vol. 1, Systematic Geology, 1878, p. 380. 'Ibid., p. 377. ' Am. PhiL Soc, Trans., vol. 16, 1889, p. 466. 4 Am, Geologist, vol. 2, 1888, p. 287. CLAKK.] WiND RIVEE — BRIDGES. 141 types Condylarthra, Tseniodonta, Pantodonta, Dinocerata, Palseosyops, and Hyrachyus." He further says : This fauna indicates the transition between the Wasatch and Bridger, since types are here associated which are elsewhere peculiar to the two horizons uamed. Thus of the above zoological divisions the following are exclusively Wasatch, Taeuiodonta and Pantodonta. The remaining oues are Bridger, excepting the Condylarthra, which probably occur in both Bridger and Wasatch. Upon paleontological grounds, then, the Wind River group occupies a position intermediate between the Wasatch and Bridger groups of the southwestern Wyoming section, and may be considered the representa- tive of the Green Eiver group. MANTI BEDS. In Sevier and San Pete Counties, in eastern Utah, calcareous shales somewhat similar to the Green Eiver strata in lithological character, and known as the Manti beds, are found. The vertebrate fauna is dif- ferent, although Grocodilus and Olastes occur, forms which are repre- sented in deposits that are found both above and below the Green River group. The Manti beds are generally considered of Green Eiver age. They have been described at length by Prof. Cope.^ AMYZON BEDS. Under the name of the Amyzon beds Cope^ includes deposits at Osino and Elko, Nevada, South Park, Colorado, and in central Oregon. As to the taxonomic position of the beds he expresses doubt, though he considers that they are probably late Eocene or early Miocene. King' considers the Nevada strata of identical age with the Green Eiver group and has so described and mapped them. There are no species identical with Green Eiver forms, although Tri- chophanes is reported by Cope to be closely allied to Amphiplaga of the Green Eiver group. On the other hand Amyzon and Trichophanes, which occur in Nevada, are also found at South Park, Colorado, together with Rhincaster apd Amia, neither of which appear in the Green Eiver group. The beds at Florissant, Colorado, have been investigated by Peale and Scudder,'' the latter of whom has described the remarkable insect fauna that the beds contain. The strata consist of shales and sand- stones and were deposited in a lake basin of limited area. BRIDGER GROUP. The deposits of the Bridger group are found chiefly in southwestern Wyoming, on the northern flanks of the Uinta Mountains, and on both 'Am. Phil. Soc, Proc, 1880, vol. 19, p. 6 ; Am. Nat., vol. 14, 1880, pp. 303, 304 ; Am. Nat., vol. 21, 1887, p. 453. 2 Am.'Nat,, vol. 13, 1879; p. 332, Am. Phil. Soc, Proc, vol. 19, 1880, p. 61. 3 tr. S. Geol. Expl. 40th Parallel, vol. 1, Systematic Geology, 1878. p. 393. *U. S. Geol. and Geog. Snrv. of the Territories, Bull., vol. 6, pp. 279-300, and Twelfth Ann. Eept. for 1878, 1883, pp. 271-293. 142 THE EOCENE. Ibull.83. the east and west banks of the Green River. To the east of this region the strata appear also in portions of western Colorado. The larger area, to the west of the Grreen River, has been termed the Bridger Basin; the smaller, to the east, the Washakie Basin. Both by Hayden and Scott the deposits of these two "basins" are considered to represent different horizons of the Bridger proper, and Hayden not infrequently speaks of the Bridger and Washakie as separate formations. Scott' says that but few vertebrate forms are common to the two areas. He considers the types of the Washakie Basin younger than those of the Bridger Basin, since the former area affords forms more closely allied to the Uinta fauna. King states that the stratigraphioal relations of the Bridger and Green River are with difQculty made out, though he thinks the "evi- dence is in fiivor of a true nonconformity."^ The deposits consist largely of sands and clays, with frequent layers of chert and limestone. King estimates the thickness of the formation in the Bridger Basin at 2,500 feet and Cope that in the Washakie Basin at 1,200 feet. A very ricli vertebrate fauna is found in which the mam- malian genus Dinoceras is held by Marsh to be the most characteristic. He has designated the Bridger group as the Dinoceras beds on that account. Of the molluscan types Unio, Planorbis, Goniobasis, and Viviparus are the most common, and according to Dr. White " correspond closely with those of the Green River, some of the species being common to both, all indicating a purely fresh-water condition of the waters in which the strata of both groups were deposited." Remains of birds, reptiles, and fish in considerable numbers are also found in the deposits.' Cope states that the Bridger is characterized by the " presence of Tillodonta, Coudylarthra and Dinocerata, Hyrachyus, Palseosyops, Amynodon, Triplopus, and Achsenodon, absence of Taeniodonta, Pantodonta, and selenodent Artiodactyla." HUERFANO BEDS. On the eastern side of the Rocky Mountains, in Huerfano and Las Animas Counties, Colorado, an extensive series of Eocene deposits have been found resting uuconformably upon strata of the Laramie and Colorado groups and containing vertebrate fossils (Tillotherium, Hyra- chyus, Glyptosaurus, Palteosyops) that point to the equivalence of the beds with the Bridger group of southwestern Wyoming. The strata attain great thickness and their character is shown in the following section by Hills :* . ' Am. Phil. Soc, Trans., voL 16, 1889, pp. 464, 465. 2 V. S. Geol. Expl.40tli Parallel, vol. 1, Systematic Geology, 1878, p. 395. 'Am. Geolofrist, toL 2, 1888, p. 288. • Colorado Soi. Soc, Proc. ,vol. 3, pt 2, 1889, p. 218. CLAKK.) HUERFANO — UINTA. 143 Foet. Marls, clays, soft shales, and sands, of red, gray, yellow, green and purple colors, red predominating 3, 300 Pink and white massive sandstone 300 Soft sandstones and fine conglomerates of a yellowish tint, with occasional bands of yellow clay or marl 3,500 The discovery of fossils has hitherto been limited to the upper divi- sion of the series.' The beds have been folded and in the vicinity of Spanish Peaks extensively altered " by proximity to the laccolithic mass of the mountains and by the numerous radiating dikes." UINTA GROCP. The Uinta group, so named by King,^ is known only from the north- ern and southern flanks of the TJinta Mountains, in northern Utah and southern Wyoming. It has been called the Brown's Park group by Powell.' According to Dr. White the strata are unconformable to the other Tertiary beds, and — it is possible that this group was deposited continuously, at least in part, with the Bridger group, but at the places where the j unction between the two groups has been seen in this region there is an evident unconformity, both of displacement and erosion. The group consists of fine and coarse sandstones, with frequent layers of gravel, and occasionally both cherty and calcareous layers occur. The sandstones are sometimes firm and regularly bedded, and sometimes soft and partaking of the character of bad-land material. The color varies from gray to dull reddish brown, the former prevailing north of the Uinta Mountains and the latter south of them. The only invertebrate fossils that have been known to be discovered in the strata of this group are some specimens of Pbysa very like a recent species. Therefore, invertebrate paleontology has furnished no evidence of its assumed Tertiary age and lacustrine condition of its deposition. Its fresh-water origin, however, seems un- questionable, because of its intracontinental position, its limited extent, and the fact that none but fresh-water deposits are known in this part of the continent that are of later date than the close of the Laramie period. ■• From the presence of the characteristic mammalian genus Diplacodon the strata have been called by Marsh the Diplacodon beds. According to Cope its vertebrate fauna is characterized by the " presence of Amynodon and selenodont Artiodactyla ; absence of Pan- todonta and Dinocerata (Scott)." Scott * says that the mammalian types of the Uinta are closely re- lated to those of the Washakie Basin of the Bridger group. 'In a more recent pnblication Hills (Abstract Coloratlo Sci. See, Proc, Feb. 17, 1891) reclassifies the Hnerfano beds as follows: S Huerfano beds. = Bruiser group. Cuchara beds. ( j „„„, ,,, „ „ Poison Canon beds. 5 ' ■ ■ " ^°^^'' Eocene. 2 U. S. Geol. Expl. 40th parallel, vol. 1, Systematic Geology, 1878, pp. 405-407. 2 U. S. Geol. and Geog. Surv. of the Territories, II Div., Geology of the TJinta Mts., 1876, pp. 62, 63. " U. S. Geol. and Geog. Surr. of tlie Territories, Tenth Ann. Eept., for 1876, pp. 37, 38. « Am. Phil. Soc, Trans., vol. 10, 1889, pp. 46C-4GR. 144 THE EOCENE. [bull. 83. SUMMARY OF OOREBLATIVE EVIDENCE. The limits assigned to the Eocene of the Interior and the different divisions that have been established for it have been presented in the previous pages. When the attempt is made, however, to correlate the various hori- zons of the Interior Eocene with the divisions of that series else- where recognized, we have bat little to guide us. The conditions under which the deposits were here accumulated afford no parallel in any por- tion of the earth's surface investigated up to this time. Great inland basins that changed from brackish water to fresh water during this epoch supported an aqueous fauna that presents almost no points of comparison with the fauna of other regions. The vertebrate animal and plant life, although affording unequivocal proof of the Eocene age of the strata from the Wasatch on, does not give grounds for more de- tailed correlation. The Laramie has afforded a few plant forms that by Newberry, Lesquereux, and Ward have been shown to be identical or closely re- lated to types recognized in the Puget group of the Pacific Coast and the Lignitic of the G-ulf border; but when so little is known of the plant remains of the American Eocene, or even with certainty of the geological range of plant species in general, correlations based upon such evidence can have but little value. That the upper portions of the Laramie may represent a part at least of the Lignitic of the Gulf border and thus the Lower Eocene, as established for the Atlantic and Gulf Coast region, has been advanced by Dr. White, and, as it seems to the writer, upon good grounds. Further correlation of the various members of the Interior Eocene with divisions elsewhere established is at present impossible. From a stratigraphical standpoint it has been customary to place the Wasatch group in the Lower Eocene ; the Green Eiver and Wind Eiver groups, which are considered equivalent to one another, in the Middle Eocene, and the Bridger and Uinta groups, which occur in stratigraphical sequence, in the Upper Eocene. There is no evidence, however, that these divisions are equivalent to those similarly named in the Atlantic and Gulf Coast region. The Wasatch, Green River, Bridger, and Uinta groups, which occur in stratigraphical sequence in the Green Eiver Basin, may be said to afford the typical Eocene series of the Interior, though it is doubtful whether deposition was continuous throughout the time of their accumu- lation. The isolated occurrences of fresh-water Eocene elsewhere are interpreted generally by comparison with the southern Wyoming sec- tion ; still direct parallelism can not always be established. The evidence for referring the upper portions of the Laramie to the Eocene has been already mentioned. What proportion of Eocene time this horizon of the Laramie should be held to represent can not be OLAEK.] SUMMARY OF CORRELATIVE EVIDENCE. 145 definitely stated, but that aa appreciable amount should be so included seems probable. Overlying the Laramie, in northern l^ew Mexico, are the Puerco beds, that, both from their stratigraphical position and fossil remains, since they lie above the Laramie and below the Wasatch and contain types of life that point to their Tertiary affinity, have been placed in the Lower Eocene. Whether they rest upon the latest horizon of the Laramie or reach to or beyond the base of the Wasatch in other areas is an open question. The supposed break between the two is represented in the accompanying table as bridged over by the Puerco beds. The Arapaho beds are found resting uuconformably upon the Lara- mie, but there is no evidence that it is the top of that formation else- where exposed. In fact the Arapaho itself has been hitherto called Laramie. Certainly the faunal relations of the Arapaho and the over- lying Denver beds point to their close affinity with the Laramie, though the structural relations of the deposits of these several horizons show a wide hiatus between them in the area of their occurrence. It seems probable that the Arapaho and Denver beds should be placed in the Lower Eocene, and doubtless below the base of the Wasatch group, since the life indicates an earlier period. A large part of the Lower Eocene is supposed to be represented in the Wasatch gronp. The fauna was in a marked degree different from that of the preceding period and the con'ditions must have altogether changed to have admitted of its existence. The Green River group is placed as the representative of the Middle Eocene. Correlated with this is the Wind Eiver group, whose contem- poraneity it is impossible to show, since the strati graphical relations of the depftsits to the Wasatch and Bridger of the Green Eiver Basin are unknown. The fauna, however, affords forms which show the interme- diate position of the Wind Eiver group between the Wasatch and Bridger, and thus in part, at least, its place as the representative of the Green Eiver group. The limits of the two horizons may not be iden- tical. The Amyzon and'Manti beds each afford a fauna that points to their dfentity with the Green Eiver group. The evidence presented admits, however, of only the most general comparisons, since but few identical forms have been recognized. ~ The Bridger and Uinta groups, which are found in superposition, have been referred to the Upper Eocene. East of the Eocky Mountains a small area in southern Colorado pre- sents a series of deposits that have been called the Huerfano beds, in which vertebrate types similar to those afforded by the Bridger group of the Green Eiver Basin have been found. Many isolated occurrences of fresh water deposits throughout the Eocky Mountain area have been referred to the Tertiary, but as evi- Bull. 83 10 146 THE EOCENE. [BtII.t.83. dence is lacking to prove their Eocene age, reference to them is omitted here. A table is given below in which the approximate position of the de- posits just mentioned in the Eocene series is presented. ,The lines do not indicate the relative thickness of the beds, but rather the propor- tionate part of Eocene time that may be tentatively assigned for their accumulation. Table showing the relative position, of the Interior deposits in the Eooene series. Cretaceous. Eooene. Upper. Lower." Middle. Upper. "Wind Eiver groap TLfanti hpds . 1 J^ 8 GKOI.nC.ICAL SURVTiY. HIII.LK'J'IN H.'J. PLA'I'K 11. JULIUS BIEN A CO LITH. EXPLANATION OF THE MAP. The Eocene area designated upon the map embraces the extreme limits of outcrop of the deposits of that horizon and not necessarily continuous exposure. More re- cent deposits frequently cover much of the surface, the Eocene outcropping only along the deeper river channels. In the Interior region the Laramie is omitted on account of the difficulty of sepa- rating that portion to be referred to the Cretaceous, which in extent probably greatly exceeds that belonging to the Eocene. Any adequate representation of the Eocene of the Pacific coast is wholly out of the question on account of the lack of available information. The limits of the areas designated are unknown. 147 BIBLIOGRAPHY." ATLANTIC AND GULF-COAST REGION. Agassiz, L. [Age of Millstone Grit of Georgia.] Boston Soc. Nat. Hist., Proc, vol. 2, 1846, p. 193. , Akerly; S. An Essay on the Geology of the Hudson River and the Adjacent Regions ; Illastrated by a Geological Section of the Country, from the Neighborhood of Sandy Hook, in New Jersey, northward through the Highlands in New- York, toward the Catskill Mountains. New York, 1820, 12 mo. 69 pp. and one plate. Aldeich, T. H. Observations upon the Tertiary of Alabama. Am. Jour. Sci., 3d ser., vol. 30, 1885, pp. 300-308. — — Notes on the Ternary of Alabama and Mississippi, with Descriptions of New Species. Cincinnati Soc. Nat. Hist., Jonr., vol. 8, 1885, pp. 145-153. Notes on che Distriljution of Tertiary Fossils in Alabama and Mississippi. Cin- cinnati Soc. Nat., Hist., Jour., vol 8, 1886, pp. 256,257. and Meyer, 0. The Tertiary fauna of Newton and Wautubbee, Miss. Cin- cinnati Soc. Nat. Hist., Joiir,, 1886, vol. 9, No. 2, pp. 40-50. Booth, J. C. Memoir of the Geological Survey of the State of Delaware ; includ- ing the application of the geological observations to Agriculture. Dover, 1841, 8vo, XI and 188 pp. Buckley, S. B. Notice of the Discovery of a nearly complete Skeleton of the Zyg- odon of Owen (Basilosaurus of Harlan) in Alabama. Am. Jonr. Sci., vol, 44, 1843, pp. 409-412. On the Zeuglodon Remains of Alabama. Am, Jour. Sci., 1846, 2d ser., vol. 2, pp 125-131. Cami'Bell, J. L. and H. D. William B. Rogers's Geology of the Virginias. A Review, Am. Jour. Sci., 3d ser., vol. 30, 188.i, pp. 357-374 ; vol. 31, 1886, pp. 193-202, Clakk, W. B. On the Tertiaty Deposits of the Cape Fear River Region. Geol. Soc, America, Bull., vol. I,'l890, pp. 537-540. Third Annual Geological Expedition into southern Maryland and Virginia Johns Hopkins University Circulars, vol. 9, 1890, pp. 69-71. Report of the Scientific Expedition into Southern Maryland. Johns Hopkins University Circulars, vol. 10, 1891, pp. 105-108. Conrad, T. A. Ou the Geology and Organic Remains of a part of the Peninsula of Maryland. Philadelphia Acad. Nat. Sci., Jour., vol. 6, 1830, pp. 205-217. Fossil Shells of the Tertiary Formations of North America. Philadelphia, 1832, 8vo, vol. 1, 56 pp. 16 i)ls. — — Observations on the Tertiary and more recent formations of a portion of the Southern States. Philadelphia Acad. Nat. Sci., Jour., vol. 7, 1834, pp. 116-129. Observations on a portion of the Atlantic Tertiary Region. Pennsylvania Geol. Soc, Trans., vol. 1, 1835, pp. 335-341, pi. 13. Observations on the Tertiary Strata of the Atlantic Coast. Am. Jour. Soi., vol. 28, 1835, pp. 104-111. Fossils of the Tertiary Formations of the United States. Philadelphia, 1838, 8vo, 89 pp. and 49 plates. Notes on American Geology. Am. Jour. Sci., vol. 35, 1839, p. 237-251. On the Silurian System, with a Table of the Strata and Characteristic Fossils. Am. Jour. Sci. , vol. 38, 1840, pp. 86-93. On the geognostic position of the Zeuglodon, or Basilosaurus of Harlan. Am. Jonr. Sci., vol. 38, 1840, pp. 381-382. Observations on a portion of the Atlantic Tertiary Region, with a Description of New Species of Organic Remains. Nat. Inst. Prom. Soi., Proc, Second Bull., 1842, pp. 171-194. * The works inclTnle J in the bibliographic list are but a sraall portion of those examined in the prep- aration of the essay. Articles of a strictly paleontological character when unaccompanied by strat- igraphical references, as well as those wliicn have only a historical value, are for the most part omitted. 148 CLAEK.) BIBLIOGRAPHY — ATLANTIC AND GULF COAST. 149 CONBAD, T. A, Observations on the Eocene formation of the United States, with de- soripfciom of species of shells, etc., occurring in it. Am. Jour. Sci.,2cl ser., vol. 1, 1846, pp. 209-ak!0,3B5-405, pis. 1-4. Observations on the Geology of a part of East Florida, etc. Am. Jour. Sci.,2d ser., vol. 2, 1846, pp. 36-48. Tertiary of Warren County, Mississippi. Am. Jour. Sci., 2d ser., vol. 3, 1846, pp. 124,125. Eocene Formation of the Walnut Hills, etc., Mississippi. Am. Jour. Sci., 2d ser., vol. 2, 1846, pp. 210-215. Observations on the Eocene formation, and descriptions of one hundred ;ind five new fossils of that period, from the vicinity of Vicksburg, Mississippi, with an appendix. Philadelphia Acad. Nat. Sci. 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Phil. Soc, Proc, vol. 19, 1880, pp. 60-62. The Manti Beds of Utah. Am. Naturalist, vol. 14, 1880, pp. 303, 304. The Tertiary Formations of the Central Region of the United States. Am. Nat- uralist, vol. 16, 1882, pp. 177-195. : Synopsis of the Vertebrata of the Pueroo Eocene epoch. Am. Phil. Soc, Proc. vol. 20, 1882, pp. 461-470. The Relations of the Pueroo and Laramie Deposits. Am. Naturalist, vol. 19, 1885, pp. 985, 986. The Mesozoic and Ceuozoic Realms of the Interior of North America. Am. Nat- uralist, vol. 21, 1^87, pp. 445-462. Mesozoic Realm. Post-Cretacic System. Am. Geologist, vol. 2, 1888, pp. 265- 267. Report of the Sub-Committee on the Ceuozoic (Interior). Am. Geologist, vol. 2, 1888, pp. 285-299. oi^K.) BIBLIOGRAPHY — INTERIOR. 157 Cope, E. J). Synopsis of the Vertebrate Fauna of the Puerco Series. Am. Phil. Soc, Trans., vol. 16, 1888, pp. 398-367. Cross, W. The Denver Tertiary Formation. Colorado Sci, Soc, Proo., vol. 3, part 1, 1888, pp. 119-133. The Denver Tertiary Formation. Am. Jonr. Sci., 3d ser., vol. 37, 1889, pp. 261- "82. DuTTON, C. E. The Physical Geology of the Grand CaHon District. U. S. Geol. Surv.j Second Ann. Kept, for 1880-'81, pp. 47-166. The Tertiary History of the Grand Canon District. U. S. Geol. Snr,v., Monograph vol. 2, 1882, xiv and 264 pp. Eldridgi:, G. H. On some stratigraphical and structural Relations of the Country about Dcnagt'. Bibikoy, N. A., on the discovery of lignite in Ricliniond County, G a 93 Bitter Creek series. Cope on the age ol. .118, 1 19 Booth, J. C, on the geology of Delaware. 23 on the occurrence of Tertiary fossils at Old Duck Creek, Del 43 Bouvg, T. T., on Eocene fossUs 28,29,50 Brandon, Vt., Hitchcock on the age of the brown coal deposit at 90 fossil fruit from, described by Les- querenx _. 91,92 Lesley on the age of the lignites at,. 91 Hitchcock on the deposits at 91, 92 Brandon formation, character and extent of 90-94 Bridger group, Hayden on the position of the 117 White on the stratigraphical relations of the 123 Cope on the character of the 126 character, thickness, fauna, and po- sition of ..141,142,145 Bridger and Green River groups. King on the relations of the 142 Buckley, S. B., on Eocene fossUs „. . 27,28 reports on the geological and agri- cultural survey of Texas by 35 Buhrstone, area and character of, in South Carolina 61,52 section 6f, at Aiken, S. C 52 character and extent of the deposits in Alabama 61,62 in Mississippi 68 in Arkansas 75 in the Gulf province 87,88 C. California, controversy between Gabb and Conrad on the age of the for- mationsin 96,97 7,82 Johnson, L. C, and Smith, E. A., on the character of the lignite beds in Alabama 58 detailed section of Claiborne group, Alabama 63,64 detailed description of subdivisions of the "White limestone in Ala- bama 65,66 Jones, Joseph. on the Tertiary lime forma- tions of Georgia and their fossils. 3S on the shell marl ot Washington and Jefferson Counties, Ga .55 Judith River deposits. Leidy on the age of the... 112 Meek and Meek & Hayden on the age of the 112, Il.S, 120 Correlated with the Laramie by White.. 122 INDEX. 167 Page. Judith River and Fort Union deposits, Cope on the occurrence o( identi- cal forms in.. ., 119 ' K. Kentucliy, reports of the geological sur- vey of 31 reports by N S. Shaler on the geol- ogy of 3.1.38 extent of the Eocene exposures in. .28, 71,8.1 division of the series by Lough- rldge Tl character of the Hickman deposits In- 7.3 extent of the Llgnitlc in . ... 7J fossil leaves from Columbus and Wickliffe described by Lesquereux 72 Loughridge on the age of the depos- its at Hickman .- 72 Loughridge on the character of the Llgnltic in (section) "2 MoUuscan forms from the Llgnitlc of, described by Heilprln... 72,73 Kerr. W. C. on theEocene InNorthCaro- ollna --- 35,49 contributions to Eocene geology by.. 35, 36 King, Clarence, on the age and relations of the coal-bearing strata of the Green Elver coal basih 115 on the stratlgraphlcal relations of the Wasatch and Laramie groups 139 on the position of the Green River groups : 142 on the Amyzon beds.. 141 on tha relations of the Brldger and Green River groups 142 on the Uint\ group (Browns Park group of Powell) 143 Kltehell. William, reports of the State geological survey of New Jersey by 30 La Grange group, Tennessee, correlation of with the Appomattox forma- tion ''1 Langdon, D W., jr.. contributions to Eo- cene geology by - 36 on the section at the Chattahoochee River 5.5 on the continuation of the Llgnitlc into the Chattahoochee drainage . 60 occurrence of the bnhrstone in the Chattahoochee noted by 61 on the Claiborne group on the Chat- tahoochee River.. 64 Laramie formation, Hague and Emmons on the age of 131 Laramie group, correlated with the Ju- dith River beds by White 122 Cope on the position of.. 121 Lesquereux on the age of 134,127 White on the 123, 124, 125, 126, 127, 128 Neumayr on the position of 127 Ward on the age of the 128 Cope on the age of.. 129 War.l on the types of the flora of the. 129 Page. Laramie group. White on its relations to earlier and later formations 1 29 discusssion of Newberry's paper on the, by Ward 130 Newberry on the 130 character, extent, and age of the 132-135 position of the 144 Laramie and Fort Union groups. White on the identity of the 135 Laramie Plains. Hayden on the age of the coal beds of 116-120 Lea, Henry C , on Eocene fossils from Alabama 21,24 Lea, I., on the Tertiary of the Atlantic and Gulf coast 21 description of new fossils by 28 comparison of American and Euro- pean fossils by 89 Le Conte, J. D. , on the age of the llgnitlc deposits of Raton Pass, New Mex- ico.. 114 Le Conte, Joseph, on the formation of Florida 30,56 Leidy, J., on vertebrate remains from South Carolina 34 on the age of the Judith River de- posits 112 Lesley, J. P., on the age of the lignites at Brandon, Vt., and Chambersburg, Pa 91 Lesquereux, L., contributions to the his- tory of the life of the Eocene, by. ^4 description of fossil leaves from Co- lumbus, and Wickliffe, Ky , by... 72 fossil fruit at Brandon, Vt., described by 91,93 on the age of the llgnitlc strata 117, 119 on the age of the coal-bearing series ..117,118 on the lignite deposits of Wyoming.. 118 on the age of the Laramie group 124, 127 Lewis, H. C, on the discovery of lignite in Montgomery County, Pa 91 on the age of the lignite iron ores 92 section of the lignite deposits at Mar- ble Hall, Montgomery County, Pa., by 93 description of Ecoene deposits near Berzelia, Richmond County, Ga., by 94 Lieber, Oscar M. , descriptions of the stra- tigraphy of South Carolina, by.... 30,50 Llgnitlc deposits, Tennessee 33,34,71,83 , Gulf States 34 Alabama 68-61,83 Arkansas 34,74,75,83 Mississippi 67,08,83 Kentucky 71-73,83 Illinois 73,83 Missouri 73,7-1,83 Louisiana 76-89 Texas 78,84 correlation of Atlantic coa.st deposits with 80-83 Gulf province 87,88 Vermont, Pensylvania and Georgia (the Brandon formation) 90-94 168 INDEX. Page. Lister. G.. on the character and geologi- cal position of the Zeuglodon 28 Little, George, on the Eocene of Georgia. 35,64 Loughridge, E. H., Nanafalia marl con- sidered Claiborne by 60 on the character and subdivisions of the Eocene in Kentucky 71,72 on the character of the Tertiary In Illinois 73 on the general boundaries of Eocene in Texas 77 Louisiana, annual reports on the geology of, by F. V. Hopkins 35 Eocene boundaries in 38,39 localities and character of the Eo- cene deposits in 75,76,84 Lyell, Charles, on American Tertiary stratigraphy 25 on the llthological similarity of the New Jersey Cretaceous to the Eo- cene and Miocene farther south .. 25 on the Tertiary strata of Marthas Vineyard 25 on the character of the Eocene in the southern Atlantic States 26 on the Miocene Tertiary strata of Maryland, Virginia, North and South Carolina.. 26 on the geologic position of the Zeu- glodon 26,65 on the sectiouat Claiborne, Ala 26 M. Macfarlane, M., geological railway guide 35 Maclure, William, classification adopted by 18 Mantl, beds, description of 141 Marcou, Jules, Conrad's position on the age of the California formations sustained by 98 on the age and fauna of the Chico- Tejon series 99,109 Marl, analysis of, by Cook 33 Marsh, O. C, on Eocene fossils 31 contributions to the history of the life of the Eocene by 34 vertebrate fossils from the Blue marl of the Upper Marl bed of New Jer- sey described by 43 on the age of the lignltic deposits of , the Rocky Mountains 116, 121 separation of the Eocene into four divisions by 121,128 Marthas Vineyard, Edward Hitchcock on the I'ertiarystrataof 20, 25 Lyell on theTertiary strataof 25 Marvlne, A. K., on the thickness of the Middle Park beds, Colorado 137 Maryland, G. Troost-on the stratigraphy of the region about Magothy Elver, Anne Arundel County in . . 20 James Pierce on the marls of 20 I. Lea on the equivalence of the Clai- borne beds to those at Fort Wash- ington in ._ 21 Conrad on the geology and fossils of. 21 Page. Maryland, Conrad on the section at Fort Washlngtonln 21 J. T. Ducatel on the Tertiary area of. 23 Lyell on the Miocene Tertiary strata of ■- - 26 notice of Tertiary in reports of Hlg- gins, State agricultiu-al chemist . . 30 presence of lignite horizon' in, be- tween Cretaceous and Eocene claimed by Conrad ^3 reports of the State geological sur- vey of, by Philip Tyson 33 distance from the coast line and width of the E ocene exposures in . 38 character and fossils of Eocene de- posits in 43,45,80 section at Fort Washington.. 45 correlation of Eocene deposits in 80 Maryland-Virginiaprovince, character of deposits in 86 Massachusetts. Whitney on the age of the hematite ore, in 90,91 Mather. W. W., on the geological recon- noissance of Kentucky, in 1838 24 Maury, M. F., reference to Eocene stra- tigraphy of Virginia by 33 McCrady, J., results of observations on the Eocene by 30 McGee, W. J., contributions to Eocene geology by -. 36 on the occurrence of the Eocene on the Nottoway Elver, Virginia 46 the LaGrange group of Safford corre- lated with the Appomattox forma- tion by , - 71 Meek, F. B., on the ags ottheFort Union beds. 120 on the age of the Green River coal basin - 115,116 on the age of the Bear Elver beds. ..115, 118 on the age of the Judith Elver beds.. 120 on the age of the Wind Elver group.. 120 Meek & Hayden, on the age of the lig- nite deposits of the Upper Mis- sourlRlver 112 on the age of the Judith River de- posits 112,113 fourfold division of the Tertiary for- mations of the Northwest by 113 on the age and character of the Fort Union (Great Lignite) group ,113 on the character of the Wind River deposits 113 section of the Tertiary formations of the Northwest 113,114 Mell, P. H., contributions to Eocene ge- ology by 36 Meyer, Otto, on the order of succession of the Tertiary formations of the Gulf States. 36 comparison of American and Euro- pean fossils by __ 89 Middle Park beds, Colorado, description of 137 INDEX. 169 Page. Miller, S. A., contributions to Eocene geology by 36 Mills's statistics, the geology of South Carolina in 20 Mississippi, contributions to the Tertiary geology ol, by Conrad .._ 28,29 table showing the geological posi- tion of the Jackson group in 29,30 Harper on the geology of 31 "Walles's report on the geology of.. 31 presence of lignite horizon between Cretaceous and Eocene in,clainied by Conrad.. 32 division of the early Tertiary into four groups in 33 observations on the geology of, by Hllgard 33 extent of Eocene exposures in 38 area, character, fossils, and Subdivi- sions of theEoceneof 66-70 generalized section of the deposits in 67 correlation of Eocene deposits in 83 Mississippi River, Ellas Cornelius on the limits of the "alluvial forma- tion" on 19 Missouri, area and character of the Eo- , cene deposits in ..73,74,83 Missouri River region. Meek and Hay- deu on the age of the deposits in the 112 Mitchell, Elisha, on the shell deposits of South Carolina 20 Morton, S. G., description of new fossils by _ 22,26,28 comparison of American and Euro- peanfosslls by 89 Moimt Diablo, California, character of strata at ' 103 Murchison, R. I., on the older Tertiary strata of America 26 N. Nanaf alia or Coal Bluff section of the Lig- nitic in Alabama 69,60 Neocene, character of 39,40 Neumayr, M., on the position of the Lar- amie group ...». 127 Nevada, Hague and Emmons on the Eocene formations in 121 Amyzon beds in 125,141 Newberry, J. S., on the age of the Tejon group of California 98 plant remains from the Puget group described by 108 on the flora and age of the Fort Union beds 114,116,135 on the age of the Green River shales 117 Puerco group referred to the Creta- ceous by. - 120 on the Laramie group 130 New Jersey, James Pierce on the marl deposits of 19 John Finch on the Tertiary deposits of : 19 Samuel Akerly on the " alluvial for- mation " of 19 New Jersey, similarity of the greensand beds of. to those of Virginia, men- tioned by W, B. Rogers 22,23 H. D. Rogers on the marls of Mon- mouth County, in.. 23 Correlation by Conrad of the Eocene deposits of, with the deposits of the Southern States 25,32 Lyell on the lithologlcal similarity ol the Cretaceous ol, to the Eocene ■ and Miocene farther south 25 Conrad on Aturia ziczac from the Upper Marl bed of 28 Cook on the marl beds of 30,33 Conrad on fossil remains in. 33 Conrad on the section at Shark River 83 Cook on the character and areal dis- tribution of the Eocene In 33 "Whitfield on the Brachiopoda and Lamellibranchiata from Mon- mouth County 37 localities, character, and fossils of the Eocene in ...38,40,41,80,85,86 lists of Eocene fossils from 43,43 Conrad on the Eocene in 80 New Mexico, Le Coute on the age of the lignitic deposits of 114 the Laramie group in 133 the Puerco beds in 138,145 North Carolina, John Dickson on the geology ol ._ 19 Dennison Olmsted on the geology of. 30 H. B. Croom on the Tertiary fossils of... ...... 33 James T. Hodge on the Secondary and Tertiary lormations in 24 Lyell on the Miocene Tertiary strata of 36 M. Tuomey on the character and age of the marl in 27 Emmons on the Eocene of 30 Conrad on the Tertiary In 35 Kerr on the limits of the Eocene in .. 35, 49 chapters on geology in the Handbook of 37 extent and character of the Eocene deposits in _ 35,38,48-50,81 commingling of Cretaceous and Eo- cene fossilsin 50 O. Olmsted, Dennison, on the geology of North Carolina 20 Orbltoides limestone ol Florida 29 Oregon, description by Gonraci and Shu- mard, Tertiary fossils from 96 White on the occurrence of Cardita planicosta in 99 localities of the Tejonstrata in 103 White on the age of the deposits at Astoria in 105 Amyzon beds in 141 Ostrea georgiana, occurrence of, at Shell Blufl, Savannah River 33 Horizon of 54 Owen, D. D., on the Eocene of Arkansas. 81,75 170 INDEX. Owen, R., on tlie mammalian cliaracter ot the Zeuglodon (Basilosaurus of Harlan) _ 27,28 Paciflc coast region, two divisions of Eo- cene of 9S historical review of the literature of .96-100 Peale, A. C, on the age of the lignitic strata of Colorado and of the Ju- dith River heds ___ 120 on the age of the Laramie, Wasatch, Gree:i River, and Bridger groups. 125 on the Amyzon beds at Florissant, Colo , 141 Pennsylvania, lignite deposits in 91, 92,93 section of the lignite deposits at Mar- ble Hall, Montgomery County, in. 93 Penrose, E. A. F. . jr. , on the Gulf Ter- tiary area. 37 on the Tertiary deposits of Texas.. 77, 78, 84 Pierce, James, on the marls ot New Jer- sey, Maryland. and Virginia 19,20 "Plastic clay formation" on Martha's Vineyard and the Elizabeth Is- .lands, reported by Edward Hitch- cock 20 Porter, S., on the shell deposits of Ala- bama 20 Prime, P., jr., on the lignite ot Lehigh County, Pa 91 Powell, J. "W., section of the Eocene at Green River, described by. 119,120 on the Brown's Park group (Uinta groupof King) 143 Powell, J. W., and White, C. A., discus- sion ot the Bitter Creek series by . 120, 131 Puercobeds, Cope on the 119, 122, 126, 127, 129, 137,138 Endllch on the.i 122,137 area, age. character, thickness, and fauna of the 119,120,126,137.138,145 referred to the Cretaceous by New- berry 120 Pugetgroup, White on the. 100 Willis on the.. 107 area, character, and fauna of 107,108 section at Puget Sound of 107 plant remains from, examined by Prof. Newberry 108 ageof the no Ravenel, Edmund, on Eocene fossils from South Carolina... 24,27, Roemer, Perd. on the Eocene of Texas.. S Rogers, H. D., on the marls of Monmouth County, N. J outline of opinions regarding Ameri- can Tertiary formations by on the character and geological po- sition of the Zeuglodon Rogers, William B., on the Eocene of Virginia 22,30, 29,50 19,31, 76,77 23 28 46-48 Page. Rogers, W. B. and H. D., on the Tertiary formations of Virginia 25 Rufan, Edmund, on the " Great Carolina bed" and th-3 Eocene ot South Carolina 27,50,51 on the character and fossils of the Eocene marls 29 S. Salford, J. M. . on the Eocene of Tennes- see ...30,31-32,34,70,71 St. John, O., on the Wind River Eocene . 125 St. Stephens Bluff, Ala., Withers on the geology of 21 Sautee beds, character of 62,53 Say, Thomas, on fossil shells 21 reference to Maryland Tertiary by.. 44 Scudder, Samuel, on the Tertiary lake basin of Florissant, Colo 125,141 Scott, William B., on the Bridger group. 142 on the mammalian types ot the Uinta group 14S Shaler, N. S., on early Tertiary strati- graphy 34,35 reports on the geology of Kentuclcy by 35, 36 Shell Blufl, Ga., character of the deposits at 64,55 section at 55 Shell Bluff group, HUgard on the position of 32 name proposed by Conrad 32,64 characteristic fossil ot 54 Shepard, Charles U., on the Eocene ot Alabama, Georgia, and Florida.. 22 Shumard, Dr., on the lignite brown coal ot eastern and middle Texas 31 on fossils from Astoria, Oregon 96 Smith, E. A., divisions of the Eocene in Alabama, by 35 continued contributions to Eocene geology, by.. 36 reports ot the Geological Survey of Alabama, by. 37 on the limits of the Eocene deposits In Florida 56 on tl^p separation of the Lignitic group from theBuhrstone 58,59 section of Claiborne Bluff, Alabama, by 62,63 Smith, E. A., and Johnson, L. C, divis- ions of the Alabama deposits, es- tablished by 68 on the character and divisions of the Lignitic In Alabama 68,59 on the separation of the buhrstone of AlabamafromtheLignlticgroup. 61 detailed section of the Claiborne group, Alabama 63,64 on the general features of the White limestone in Alabama 65 detailed description ot subdivisions of the White limestone in Ala- bama 65,66 South Carolina, John Dickson on the ge- ology of 19 INDEX. 171 Page. South Carolina, John Finch on Tertiary deposits of _ 19 the geology of, in Mills's statistics... 20 Elisha Mitchell on the shell deposits of 20 Conrad on the section at Eutaw Springs in _ _ 21 Dr. Morton on the fossils from the "White limestone" of 23 Edmund Eavenel on Eocene fossils from 24 James T. Hodge on .the Secondary and Tertiary formations in 24 Lyell on the Miocene Tertiary strata , of 26 Edmimd Euffln on the "Great Caro- lina bed" of 27 Tuomey on the age of the Eocene for- mations in - 27 three divisions of the Eocene forma- tions of, proposed by Tuomey... 28,51 annual reports of the State Geologist of, Oscar M. Lieber 30 presence of lignite horizon between the Cretaceous and Eocene, claimed by Conrad 32 H. Hammond on the geology of 37 area of Eocene exposures in 38 description of fossils from 50 area, character, subdivisions, and fossils of the Eocene iu 50,54,81,83 Stevenson, M.F., on the geology and min- eralogy of Georgia 35 on inland boundary of the Eocene deposits in Georgia 54 Stevenson, J. J., on the age of the lignitic deposits of the Northwest 119 Sweetwater region, Endlich on the geol- ogy of the - 1S4 T. Tejon group, California, name proposed by Whitney. 98 age of .' 98,99 localities, character, extent, and age of the strata of the.. 100, 101,108, 109, 110 character of the deposits in Contra CostaCounty, Cal.. 103 localities of, iu Oregon. 103 fossils referred to, by Gabb and White 104,106 fossils from the Dwamish Eiver, Washington, referred to 106 Marcou on fossil genera from the 109 Tennessee, G. Troost on the geology of . . 24 Saftord on the lignite beds of 31,34 extent of the Eocene deposits in 38,70 area and. character of Eocene in. .70, 71, 83 Saftord's subdivisions of the Eocene in 70,71 Tertiary, twofold character of 16 Texas, Roeraer on the Eocene of... ; 29,31 Shumard on the lignite brown coal of eastern and middle 31 reports of the Geological and Agricul- tural Smrvey of. by S. B, Buckley 35 rage. Texas, Penrose on stratigraphical rela- tions of the Eocene in Frst An- nual Report of the Geological Sur- vey .' 37 area, character, extent, and fossils of the Eocene of 76-79 correlation of Eocene deposits of 84 Trask, J. B., description of new species from Chico Creek, iCal. , by 9S Troost, G., on the stratigraphy of the re- gion about Magothy Kiver. Anne Arundel County, Md 10 on the geology of eastern Tennessee. 34 Tuomey, M., on the Eocene stratigraphy of Virgi,uia 24 on the character and divisions of the Eocene in North Carolina 27,28,50,51 on the character and geological hori- zon of the Zeuglodon 28 on the Tampa Bay limestone 29 ou Eocene fossils 29 on the extent, structure, and stratig- raphy of the early Tertiary of Al- abama _.. 31 on localities and fossils of the Buhr-, stone iu South Carolina 52 list of fossils from the Santee beds by _ 53 list of fossils from the Ashley aiid Cooper beds, by 53 on the Eocene of Florida.. __, 55 Turritella Mortoni, horizon of 45 Tyson, Philip T., on the Tertiary geology of Maryland 33,44 U. Uhler, P. E. , contributions to Eocene geol- ogy by 36. characteristic fossils from the eastern shore of the Chesapeake reported by 45 on the horizon of Gucullcea gigaiitea.. 45 Uinta group. Cope on the character of the 126 named by King __ __ 143 White on the character and fossils of the 143 Scott on the mammalian types of the. 143 position of the .144,145 Upper Marl bed of New Jersey, strati- graphical sequence of the deposits of 41 Upper Missouri River, Meek and Hayden on the age of the lignite deposits of 112; Utah, Hague and Emmons on Eocene groups in 121 Laramie group in 133. Bear Eiver estuary in ._- 135 Uinta group in 143 Cope on the Mantibeds of 125,141 Wasatch group in 139. V. Van Rensselaer., Jer., on northern Ter- tiary series 20i 172 INDEX. Page. Vanuxem, Lardner, on the limits ol the Tertiary 30 Vermont, the Brandon formation in 90-93 Vicksliurg group, position of the Orbito- Ute limestone in 30 In Florida ....55,57,82 in Alabama - 64,66,83 in Mississippi.... 69,70,76,83 section at Vickshurg Bluff, Missis- sippi 70 In Louisiana 76,84 Virginia, John Finch on the deposits of the James Kiver in.. 19 James Pierce on the marls of 20 W. B. Rogers on the Tertiary geology of : 32,23 Ly ell on the Miocene Tertiary strata of 26 Maury's physical survey of 33 Jed. Hotchkiss on the Tertiary geol- ogy of J 35 area of Eocene exposures in 38 area, localities, character, and fossils of the Eocene in 46^8,80,81 section at Acquia Creek 47 list of Eocene fossils from 48 Vogdes, A. W.jOn early Tertiary stratig- raphy '- 34,35 W. "Wailes.B.L.C, report on the geology of Mississippi 31 "Ward, Ijester F,, on the flora and age of the Laramie group ..138,129 localities of fossil leaves from the Eocene of the interior region cited by... 129,130 discussion of Newberry's paper on the Laramie group by 130 list of identical species from the Lar- amie and Fort Union groups by 135 on the age of the Fort Union beds 135 "Wasatch group, position of the. .117, 139, 144, 145 correlated with the Fort Union by White 122 White on the stratigraphlcal relations of the 123 Cope on the character of the 126 areas, relations, and fauna of the 139 position of the .144,145 "Washakie group, Hay den on the. 117 "Washington, localities of the Puget group in 100 "White on the age of the Puget group in 100 Tejon species from Dwamish River in 106 the Puget group in 107,108 "White, C. A., contributions to Eocene geologyby 36 on the presence of the Laramie in Texas 78 on the Puget group 95,100 on the occurrence of Cardita plani- costain Oregon 99 on the age of the Chico-TeJ on series . . 99 Page. White, C. A., on the Chico-Tejou series, in the vicinity of Nev^ Idria 103 fossils referred to the Tejon group by 105 on the age ol the deposits at Astoria, Oregon. 105 on the commingling of species in the Chico-Tejon series 106 on the f auual similarities of the Puget and Laramie groups .... 110 Fort Union group correlated with the Wasatch by 133 Judith River beds correlated with the Laramie by ..'. 133 table of correlated general sections of the western formations by 128, 133 on the conflicting evidence afforded* by the fauna and flora of the Lara- mie group 137-128 comparison of the Laramie Sea to the Caspian by 137 on the relation of the moUuscan and fresh water Eocene faunas of the Laramie group 138 on the contemporaneous existence of Cretaceous and Tertiary faunas and floras 139 on the relations of the Laramie to earlier and later iqrmatlons 129 on the Laramie groiip..l33, 124, 135, 136, 137, 128, 139, 135, 139 on the stratigraphlcal relations of the Wasatch, Green River, and Bridger gi'oups 123 on the appearance of mammalia in the beds overlying the Laramie 135 on the position of the deposits overly- ing the Laramie 126 on the Identity of the Laramie and Fort Union groups 135 on the stratigraphlcal position of the Puercobeds 138' on the stratigraphlcal relations of the Wasatch and Laramie groups. 139 on the character of the Uinta group. 143 "White, C. A., and Powell, J. W., discus- sion of the Bitter Creek series by .130, 131 "White limestone in Alabama, detailed description of.. 64-66 Whitfield, E. P., on Eocene fossils 31 on the Brachiopoda and Lamellibran- chlata from Monmouth County, New Jersey... 37 list of fossils from the Blue marl of the Upper Marl bed. New Jersey. 42 Whiting, Maj. Henry, on the geology of eastern Florida 24 Whitney, J. D., on the age of the hematite , ore beds in western Massachu- setts 90,91 on the Tejon group 95,98 on the characteristics of the Eocene in California 97 on the strata in Contra Costa County, California 103 INDEX. 173 Page. Willis, Bailey, on the deposits In the vi- cinity of Puget Sound and on the ^ east slope of the Cascade Moun- tains 99,100,107 Winchell, Alex., on the Eocene of Ala- bama 30,36 Wind Ri v»r beds, olWy oming. Cope on the 1 35 character of the 115 Meek on the age of the 120 St. John on the character of the 125 age, character, and fauna of the 140, 141, 144, 145 Wind Elver and Green Elver groups, equivalence of the.. 144 Withers, E. W., on the geology of St. Stephens Bluff, Alabama 21 Worthen, A. H., on the extent of the Eocene strata in Illinois 73 Wyman, Jeffries, on the character and geological horizon of the Zeug- lodon 28 Wyoming, Hayden on the Tertiary basin of 117 Cope on fossil vertebrates from 118 Lesquereux on the lignite deposits of. 118 Hague and Emmons onEocene groups in 121 Cope on the Wind Elver bedsol 125 Page. Wyoming, Laramie group In 13S Wasatch group in 139 Green Biver group in .; Wtt Bridger group in 141,142 Uinta group in 14S Zeuglodon, Conrad on the geologic posi- tion of 23 Lyell on the geologic position of 26, 65 described as a saurian (Basilosaurus) by Harlan 27 mammalian character of 27,28 Buckley on the character and horizon of 28 Gibbes on the character and horizon of 28 Rogers on the character and liorizon of 28 Tuomey on the character and horizon of 28. Wyman on the character and horizon of 28 Hale on the position of.. 65 Hilgard on the position of 65 from the Jackson group 69,76