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 Oliver Perry Hay

INDIANA.

(Map [37].)

Whoever wishes to gain a knowledge of the Pleistocene geology of Indiana, as it is understood to-day, must study Leverett’s two great treatises, forming Monographs XXXVII and LIII of the U. S. Geological Survey. The first is entitled “The Illinois Glacial Lobe,” and was published in 1899; the second has the title “The Pleistocene of Indiana and Michigan and the History of the Great Lakes.” The portion of the latter monograph which deals with Michigan was written by F. B. Taylor. On pages [33] to [54] is a very full bibliography of the subject, consisting of about 400 titles.

From the glacial map of Monograph XXXVIII, plates V and VI, the writer has prepared map [37]. This shows which part of the State has escaped glaciation, which has been subjected to the action of the Illinoian ice-sheet, and which has been covered by the last, or Wisconsin, glacial ice. It will be seen that about one-sixth of the State, that forming an irregular triangle whose apex is in Brown County and whose base is formed by the Ohio River, has never been covered by glacial ice. North of this is a bilobed area which is covered by till of Illinoian age. The rest of the State (somewhat less than two-thirds of it) is overlain by the débris left by the Wisconsin ice-sheet and subsequent deposits.

This northern area is to a great extent occupied by belts called moraines, along which the materials are usually coarse, often full of boulders, and frequently standing at a higher level than the surface on each side of them. These moraines show where for long periods during its retreat, or perhaps sometimes its advances, the ice-sheet paused and piled up a part of its load of rocks, gravel, and sand. It will be noticed that these moraines are somewhat concentric. On the right of the map are seen those moraines which were left by the ice-lobe which came down Lake Erie and later retired in that direction. Around the southern end of Lake Michigan are the moraines laid down by the ice of the Michigan lobe. The latter will be better seen on a glacial map of Illinois (Monogr. U. S. Geol. Surv. XXXVIII, plate VI). In their advance the two lobes met and coalesced and produced more or less irregular and anastomosing moraines.

On the right hand the moraines of the Erie lobe pass on into Ohio, where, however, they have often been given other names. On the left the moraines of the Lake Michigan lobe continue into Illinois and retain the same names. Both groups of moraines are prolonged into the southern peninsula of Michigan.

On account of the comparatively recent recession of the Wisconsin ice-sheet, the surface has not become eroded sufficiently to drain away the water which was left in depressions of the surface. A large part of Indiana is, or has been until recently, covered by swamps, lakes, and ponds, and in such localities the bones and teeth of vertebrate animals are best preserved during the early stages of fossilization. For this reason great numbers of teeth and bones, sometimes nearly whole skeletons, are met with in draining these swamps.

The southern border of the Illinoian drift, beginning at Cincinnati, follows Ohio River on the Kentucky side to Jeffersonville, then passes west of north into Brown County, whence, turning southwest, it strikes the East Fork of White River in Du Bois County; thence, following White River a short distance, it crosses the Wabash in Posey County. Northward, along this terminal moraine (map [37], figs. 1, 2) of the Wisconsin drift, the Illinoian, passing beneath this, disappears from the surface.

The surface of the Illinoian area is better drained than the Wisconsin area. Fewer fossils are found, and on various accounts they are of less value. Usually the exact locality and kind of deposit is not recorded. They may be found washed out of river and creek banks and may have in reality been buried in sediments that were laid down in Wisconsin times by the streams that carried away the mud, sand, and gravel from the glacier. The driftless area has been exposed for many geological ages to the influence of physical and chemical agencies. Its surface is, therefore, more diversified by hills and valleys and streams. In the limestones of this region caves are likely to be found, and these now and then furnish fossil bones and teeth.

During more than one of the glacial stages, perhaps during the earliest, the Ohio has served as the drainage-way for the waters that escaped from the glacial front. This subject is discussed by Leverett in Monograph XLI of the U. S. Geological Survey. As a result of this conveyance of glacial waters, the great trough of this stream may contain here and there deposits of the Illinoian stage or even of older deposits. Remains of Megalonyx (p. [32]) and of a horse (p. [186]) have been found in the right bank of the Ohio, at Evansville, Indiana. At Bigbone Lick, Kentucky, close to the Ohio, horses have been discovered, Mylodon and Megalonyx. These seem to occur in Sangamon interglacial beds overlying the Illinoian.

The Illinoian drift, probably everywhere in central and northern Indiana, underlies the Wisconsin. For some miles back from its terminal moraine the Wisconsin drift is thin; and possibly the Illinoian may. be found exposed in creek or river banks, or in railroad cuts. Furthermore, Leverett (Monogr. LIII, p. 72) writes:

“Probably a considerable number of the heavy deposits of drift in central and northern Indiana are of pre-Wisconsin age, but as they are largely sand and gravel, or loose-textured material, they can not easily be discriminated from the Wisconsin.”

Such deposits are likely to be covered by only a thin layer of Wisconsin till. In many places in Indiana there have been found, deep down in the drift, old soils, muck beds, and vegetation in various forms. These beds appear to indicate interglacial deposits, most probably the Sangamon. Now, various genera of vertebrates, among them horses, tapirs, and mylodons, are not known to have existed after the Wisconsin glacial stage. If, however, remains of such animals should be collected in central or northern Indiana, or Ohio, or in southern Michigan, they might be reported as having been found in late Wisconsin beds, when really they had been derived from pre-Wisconsin interglacial soils.

It is interesting to observe that when the Wisconsin ice-sheet began to withdraw lakes began to form along its borders. One of these, Lake Chicago, appeared at the south end of the present Lake Michigan and for a long time discharged its waters down Illinois River. Another, Lake Maumee, occupied the basin of Maumee River as far west as Fort Wayne, and emptied down the Wabash. For details connected with the close of the Pleistocene in the region of Lake Michigan the reader should consult Frank C. Baker’s “The Life of the Pleistocene, or Glacial Period” (Univ. Ill. Bull. XVII, 1920).

A brief mention will be made here of the principal Pleistocene vertebrates that have been found in Indiana; also the localities where found, together with citations of the pages where fuller information is furnished.

The ground-sloth Megalonyx has been collected near Evansville (p. [32]). With it were secured remains of an undetermined bison (p. [257]), a Virginia deer (p. [228]), a horse (p. [186]), a tapir (p. [203]), and the dog Ænocyon dirus (p. [32]). Peccaries have been found in Gibson County (p. [216]), in Wabash County (p. [218]), and two species at Williams, Lawrence County (p. [217]). At the same place was discovered the shell of a box-tortoise. Remains of deer have been discovered somewhere in Vanderburg County, including the existing deer and an extinct species, Odocoileus dolichopsis; at Harrisville, Randolph County; and at Roann, Wabash County. Bisons of an extinct species have been secured at Vincennes (p. [258]).

The existing bison appears to have been found in Jasper County (p. [268]). Of musk-oxen, Symbos cavifrons has been collected at Hebron, Porter County (p. [252]); at Wailesboro, Bartholomew County (p. [251]); somewhere in Randolph County (p. [252]); and probably in Beaver Lake, Newton County (p. [252]). The existing musk-ox, Ovibos moschatus, has been discovered near Richmond (p. [252]).

Mastodon remains are not uncommon, especially in the northern half of the State. It is hardly to be supposed that these animals were more abundant there during the late Pleistocene than in many other places in the region east of the Mississippi. The conditions for their preservation were evidently more favorable there than anywhere else, unless in Orange County, New York. Burial in swamp mud kept the bones from decay; and the imperfect drainage protected them from destruction by erosion. The various finds are described on pages [88] to [100].

Elephants are less well represented in Indiana than are the mastodons, but are not rare (pp. 138, 151, 171). Two species were present in the State, Elephas primigenius and E. columbi. Beavers were doubtless abundant, but there appears to be no definite record of any find. However, the giant beaver has been recorded from several localities (pp. 276 to 278).

The great extinct dog Ænocyon dirus was first found near Evansville (p. [32]), and the coyote, Canis latrans, has been reported from Boone County. The latter is said to have been found in association with the mammoth (Cope and Wortman, 14th Ann. Rep. Geol. Surv. Indiana, p. 7).