Read Ebook: The Pleistocene of North America and its vertebrated animals from the states east of the Mississippi River and from the Canadian provinces east of longitude 95° by Hay Oliver Perry

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Equus idahoensis. E. excelsus? Protohippus? Rhinoceros, probably Aphelops fossiger. Mastodon mirificus. Cervus, possibly new. Smaller and more slender than C. canadensis. Procamelus, size of P. major. Tragocerus? horn-core of antelope. Ischyrosmilus n. sp. Morotherium leptonyx. Castor, possibly n. sp. Olor, size of O. paloregonus. Graculus idahoensis.

In 1889 , Professor E. D. Cope published a list of fossil mammals collected in the "Oregon desert," apparently somewhere in the region of Silver Lake or Summer Lake. The list is as follows:

Canis sp. indet. Elephas or Mastodon. Holomeniscus or Auchenia. Aphelops sp. indet. Hippotherium relictum. Equus sp. indet.

Cope looked upon this collection as remarkable in that it showed the presence of true horses and camels associated with a rhinoceros. He concluded that the fossils belonged to his Idaho formation. Dr. W. D. Matthew thought that the collection was a mixture of fossils from two formations . It may, however, have been made in Nebraskan deposits.

In 1921 , the writer described a collection of vertebrate remains from Anita, Coconino County, Arizona. These remains were found in a cave in making explorations for copper ore. The list follows:

Equus occidentalis. E. giganteus? Mylohyus? sp. indet. Procamelus coconinensis. P. longurio. Antilocapra americana? Marmota arizonae. Citellus tuitus. Neotoma cinerea. Lepus benjamini. Brachylagus browni. Taxidea robusta. Canis nubilus? C. latrans? Chasmaporthetes ossifragus.

The presence of rhinoceroses in the formation is believed to establish definitely the fact that the beds can not be later than the early Pliocene, since rhinoceroses in America apparently did not survive beyond that time .

According to Sellards the hard phosphate, belonging to the Alachua formation resulted from a disintegration of underlying Upper Oligocene deposits and probably the Vicksburg limestone. Through chemical action these rocks were partly dissolved and the residual materials were mixed by local subsidence and by action of streams and later modified by chemical changes.

The land-pebble phosphate of the Bone Valley formation had, Sellards concluded , resulted from underlying phosphate marls of Upper Oligocene age. This occurred during a time of general subsidence of sufficient extent to permit marine waters to reach the area covered by the Bone Valley phosphates. The presence of sea-water is indicated by the occurrence of bones of cetaceans.

With regard to the effects of streams and of the chemical action of the water on the rocks, which contributed to the formation of the hard rock phosphate and the production of sinks and caves, it may be remarked that we know of no time when rocks were dissolved and caves formed to the extent that they were during the Pleistocene.

As shown on page 15, various deposits of marine marls along the Atlantic coast are referred by the writer to the Nebraskan. Among these marls are the coquina rock found at St. Augustine and the marine marl underlying the bed at Vero, which contained early Pleistocene vertebrate fossils. These marls are known to extend well inland, being found at Kissimmee, 50 miles from the coast. In some places they are met with at depths of 70 feet . Marls of probably the same age occur on the western coast of Florida . The writer believes that some of these marls may yet be connected with the phosphate beds of the Bone Valley formation.

A figure taken from Sellards may be found on page 377. This illustrates the relation of the Dunnellon and Bone Valley formations to the underlying deposits.

Mention has been made of collections of fossil vertebrates which long ago were secured at Fossil Lake, Oregon, and of others along Niobrara River, near Grayson, Nebraska. Lists of the species found at each locality were given by Dr. W. D. Matthew in 1902 . These deposits and animals were regarded by Cope and Marsh as belonging to the Pliocene, until G. K. Gilbert, in his work on Lake Bonneville showed that the Oregon fossils must belong to the Glacial epoch, but he referred them to a late time in this epoch, that of the last glaciation. It thus became quite impossible to determine the age of any collection of fossil vertebrates.

In 1887 , Williston wrote:

Up to the present time the interglacial soils found in a few localities between the Kansan and the Illinoian drifts have furnished only scanty remains of vertebrate fossils--a rabbit and a skunk at the type locality in Iowa. Certainly, however, the same animals were living then that were found at later stages.

Another assemblage that probably belongs here is that made at Toronto . This indicates a warm climate, since the pawpaw and the osage orange grew there.

This is the interglacial interval between the Iowan glacial and the Wisconsin. It was probably not of long continuance and is chiefly remarkable for the deposition of loess. This has not furnished any important collections of vertebrate fossils. The type locality for the Peorian stage is a locality east of Peoria, Illinois. Leverett mentions several cases in which old soils believed to belong to the Peorian were observed in Illinois. None of these has furnished vertebrate fossils. It is usually difficult to distinguish the Sangamon from the Peorian soils.

The next stage which furnishes abundant vertebrate fossils is the Wisconsin. These remains are found most abundantly in the old soils and mucks which accumulated in the swamps, ponds, and lakes left on the uneven surface of the Wisconsin drift as the ice retired. To such deposits the writer has given the name Wabash beds. They are often called post-glacial deposits; but that term ought in strictness to be applied only to deposits of the present epoch. They may be called Late Glacial, but that expression has been used for the drift and moraines produced by the second half of the Wisconsin glaciation. It might be better to use for the divisions of the Wisconsin the terms Lower and Upper.

The writer will discuss briefly the widely accepted theory that along the sea-coast from New Jersey to southwestern Texas there occurs a series of terraces and corresponding escarpments, three or more in number, representing successive emergences of the borders of the continent from the sea. The theory was first proposed by Dr. W. J. McGee . He included in the initial submergence not only the area occupied by the supposed Pleistocene terraces, but also the borders of the coasts to an elevation corresponding to the Lafayette formation, which he referred provisionally to the late Pliocene. This submergence required a depression of the eastern half of the continent amounting to 500 feet or more. The theory was accepted especially by the geologists of Maryland in their excellent reports . It has likewise been applied to the geology of Virginia , North Carolina , Georgia , as Okefenokee and Satilla; , Florida , and to Texas .

In Maryland and the District of Columbia there have been recognized three Pleistocene terraces . The uppermost is the Sunderland, the next the Wicomico, the lowest the Talbot. These are not correlated by Shattuck definitely with glacial divisions of the Pleistocene, but the Sunderland is the oldest, while the Talbot is regarded the most recent, probably about the age of the last glacial stage, the Wisconsin.

When the writer began his study of the Pleistocene he accepted the theory proposed by McGee and the Maryland geologists, and traces of this acceptance may be found in this work; but he is now convinced of its falsity. It is hardly to be believed that the coastal region could have been occupied, even at intervals, since the late Pliocene, when the depression is supposed to have been at least 500 feet, and 200 feet during the Sunderland, down to the end of the Wicomico and even the Talbot, without its having left other traces of marine occupation than the supposed terraces and escarpments. There ought to appear somewhere in the long border from New Jersey to Mexico abundant and extensive deposits of stratified materials, clays, sands, and gravels. Such deposits appear to be relatively rare.

A still more serious objection to the theory of submergence beneath marine waters is the absence of marine fossils. In the materials forming these terraces one might with confidence expect to find at least marine mollusks, mussels, clams, and beds of oysters; probably also remains of fishes, of porpoises, and of whales. Leaving out of consideration the Talbot terrace, which is near sea-level , the supporters of the theory under consideration admit that not in the Lafayette, nor the Sunderland, nor the Wicomico, have any traces of such fossils been met with. On the other hand, all over these terraces are found remains of land animals and plants. Mastodons, elephants, and horses are by no means rare. Conditions favorable for the preservation of teeth of proboscideans must have been quite as well adapted to preserve shells of oysters. In the Sunderland and Wicomico a few land plants have been secured, an abundance of them in the Talbot. Map No. 39 shows the distribution of Pleistocene mammals, mollusks, and plants on the Coastal Plain of North Carolina.

It seems evident, therefore, that the sea has had nothing to do with the formation of the Lafayette, the Sunderland, and the Wicomico terraces, and little with that of the Talbot. It was natural that the advocates of this theory of the formation of these terraces during the Pleistocene should distribute them somewhat impartially over the time of this epoch, assigning the Talbot to a late interval. On page 11 the writer has called attention to the fact that in many places along the coast from southeastern Texas to New Jersey, at or near sea-level, there are beds which contain a vertebrate fauna of the Aftonian or first interglacial stage. Probably nowhere do these beds have any large amount of later materials overlying them; it is often extremely little. So far as the writer can judge, this means that all the terraces and escarpments were produced before the time of the first interglacial; not since that distant time has there occurred along the Gulf or Atlantic coasts south of New Jersey any considerable elevation or depression of the Coastal Plain.

FINDS OF PLEISTOCENE CETACEANS IN EASTERN NORTH AMERICA.

ONTARIO.

QUEBEC.

NEW BRUNSWICK.

VERMONT.

NORTH CAROLINA.

SOUTH CAROLINA.

GEORGIA.

FLORIDA.

FINDS OF PLEISTOCENE PINNIPEDIA IN EASTERN NORTH AMERICA.

GRINNELL LAND.

NOVA SCOTIA.

NEW BRUNSWICK.

QUEBEC.

It is evident that when that animal died and was buried in the clay the land in that region stood at a level at least 100 feet lower than at present.

Through the late Mr. L. M. Lambe, of the Canada Geological Survey, the writer has received from Mr. W. A. Johnston, who made a special study of the Pleistocene, information regarding the age of the clays at Bic. He says that little can be said definitely regarding the age of the clays in which the walrus skeleton was found. Clays belonging to the Champlain submergence stand now at an elevation of 311 feet in that vicinity; and marine shells occur in clays, supposed to belong to the Champlain, at an altitude of 120 feet. There is a possibility that some of the clays in that region are earlier than the time of the Wisconsin. Mr. Johnston cites Guide Book No. 1, part I, pp. 77-78, of the Canada Survey, and Dawson's Ice Age, 1893, pp. 186-195. The first article was written by J. W. Goldthwait. On page 921 of Logan's Geology of Canada, 1863, it is stated that bones of whales and of the morse have been found partially embedded in the Leda clay in several places between Bic and Matanne, about 60 miles farther down the river.

ONTARIO.

Later, at the same locality, a lower jawbone of a young seal was found, which was identified as the harp seal; and it was even thought that it might have belonged with the hinder limbs figured by Leidy. A figure of this jaw, with some of the teeth, was published by Dawson in his "Canadian Ice Age."

MAINE.

In his discussion of the supposed bison teeth found in clay at Gardiner, Dr. J. A. Allen gives us some information about the fate of Mrs. Frederic Allen's collection. At her death it passed into the possession of her daughter, by whom the greater part of it was presented to Bowdoin College, Brunswick, Maine. Professor Manton Copeland, of this college, informs the writer that the walrus tusk is in their collection and bears the number FM20. It is badly shattered. The length is about 75 mm.

The important matter concerning the remains of the walrus found at Gardiner is to determine when the animal lived there. It is to be assumed that the tusk had been buried in the Pleistocene clay at that locality. This appears to belong to the closing period of the Wisconsin stage, but there has been some dispute about its age.

Packard gives a list of the species which had been found in the clay at Gardiner. These are nearly all invertebrates and indicate a climate somewhat colder than that now existing there. Whether the time when the walrus lived at Gardiner was before or after the culmination of the Wisconsin ice period, it was so long ago that those deposits of clay, made in sea-water of considerable depth, have since been lifted above sea-level to a height of perhaps 200 feet.

Above the lighter-colored clay just mentioned was a foot of a clay which contained wood and roots, the unused portion of the brick clay that once existed there, but which had been removed for the manufacture of bricks.

Inasmuch as the clay overlying the bed in which the remains were found contains marine shells, it is certain that since their deposition the land has been considerably elevated.

George N. Stone has discussed the age of the glacial deposits at Portland. Professor M. L. Fuller has written to the author that on the Maine coast the chief clay is known as the Leda and is found at Portland and Gardiner, and that it probably antedates the Wisconsin. This is not to be correlated with the Leda clay of the St. Lawrence Valley. It corresponds rather to Clapp's "high-level clays" .

NEW HAMPSHIRE.

MASSACHUSETTS.

Inasmuch as the Tertiary deposits at Gay Head, rising above the sea to a height of about 150 feet, are capped by a sheet of glacial drift and clays, it is probable that the skull in question had fallen from some of these drift deposits. According to Professor J. B. Woodworth , there are at Gay Head deposits of drift which represent some of the older glacial stages as well as the last one, the Wisconsin. It is possible, therefore, that this walrus lived there as far back as the middle of the glacial epoch or even earlier. For additional information on the geology of that island consult Woodworth's paper, in which the literature is cited; also the important paper by N. S. Shaler

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