Fig. 22.—The Mississippi embayment. Redrawn from Hilgard. Used to show the distribution of the Port Hudson group.
Although Hilgard represents on his map an alluvial deposit as covering the region of the delta, a belt along the western side of the great river as far up as Cairo, and the wide tract between Mississippi and Yazoo Rivers, a study of his paper shows that he believed that much of these regions was underlain by his Port Hudson. He recognized it at Greenwood on the Yazoo, 60 miles east of the Mississippi; at Vicksburg, and at various places in the delta. Usually its upper surface occurs at about low-water level along rivers, and elsewhere is met with in digging wells. At Vicksburg it was encountered by Grant’s Army in digging his famous canal. It was believed by Hilgard that the same deposit was present at Petite Anse, overlying the Orange sand and overlain by more recent deposits.
Inasmuch as Hilgard believed that the Orange sand was laid down at the time when the northern drift was being deposited, he had to refer his Port Hudson to a later time, and this time he seemed to regard as being the epoch called by Dana the Champlain.
McGee referred the deposits of the lower Mississippi Valley (sometimes called the Mississippi embayment) to his Columbia formation (12th Ann. Rep. U. S. Geol. Surv., plate I, p. 392). This formation, in his view, had been laid down during a great subsidence of the borders of the continent and when the waters of the Gulf reached as far north as the mouth of Ohio River or beyond. He relegated Hilgard’s Orange sand to the Pliocene and recognized four phases as belonging to the Pleistocene. These were, beginning below: (1) Port Hudson; (2) Orange sand (of Safford, not that of Hilgard); (3) loess; (4) brown (or yellow) loam. Of these divisions there were really only three, for he regarded the loess as only a phase of the loam and as lying sometimes above, sometimes below the latter. He recognized the Port Hudson clays as flooring the entire flood-plain of the Mississippi from the mouth of the Ohio well toward the gulf shore. The formation was believed to be usually a low-lying one; but at Natchez (as seen by his section given on page 391) it is elevated high above the present flood-plain.
Gilbert D. Harris, geologist in charge of the geological survey of Louisiana, and Arthur C. Veatch, assistant geologist, have contributed much to our knowledge of the Pleistocene geology of the State. Reference to their works will be found in the descriptions of several fossil-bearing localities, especially in the description of Petite Anse.
Harris, in 1905 (Bull. 1, Geol. Surv. Louisiana, p. 13), expressed the conclusion that the longer the geology of southern Louisiana is studied the more futile appears the attempt to make satisfactory subdivisions in the Quaternary deposits—subdivisions that have any definite time or structural limits. He regarded it as a mistake to assign to the Port Hudson a special place in geologic time.
Chamberlin and Salisbury in 1906, as quoted below, made no mention of the Port Hudson formation; but that part of it supposed to be found at Natchez was evidently included in their Natchez formation.
Inasmuch as Petite Anse and Natchez have furnished more species of fossil vertebrates than any other localities in their States, and likewise human relics supposed to be of equal age with the extinct mammals, these places will receive especial attention.
Natchez is the most important locality in Mississippi as regards Pleistocene vertebrate palæontology. So far as the writer knows the first mention of the occurrence of vertebrate fossils here was a note by Dr. G. Troost in 1835 (Trans. Geol. Soc. Penn., vol. I, p. 143), who stated that he had in his possession a tooth of a mastodon found at Natchez.
In 1845 (Proc. 6th Meet. Assoc. Amer. Geologists and Naturalists, pp. 77–79), Dr. M. W. Dickeson, of Natchez, read a paper entitled “On the Geology of the Natchez Bluffs,” in which he distinguished 22 several beds. These were said to be of varying thickness and distinctly marked, but all composed of various colored clays and sands, and containing numerous organic remains, embedded wood, and detrital matter. Probably by far the greater part of these beds were of subordinate importance and do not appear to have been noted since that time. Beneath the surface soil Dickeson recognized a mass of yellow loam 20 to 30 feet in thickness, exceedingly fine and free from gravel. In this had been found shells of Helix and scattered bones of mastodons. Below this came a bed of ferruginous sands and gravels 4 feet thick. This was succeeded below by what he called the mastodon bed, in which Dickeson had detected remains of more than 30 individual mastodons. The thickness of this was not given. The next stratum, his No. 6, was a fine clay of blue color, from 12 to 15 feet thick. In this and his No. 22, an ash-colored clay, at low-water mark, he discovered remains of what has since proved to be Megalonyx jeffersonii. The localities where his fossils were found were not given with exactness.
At a meeting of the Academy of Natural Sciences, October 6, 1846 (Proc., etc., vol. III, p. 107), Dickeson exhibited a large collection of fossil bones obtained by him in the vicinity of Natchez. Among these were the head and lower jaw of the Megalonyx already mentioned. He stated that the stratum that contains these organic remains is a tenacious blue clay that underlies the diluvial drift east of Natchez and which diluvial deposit abounds in bones and teeth of the Mastodon giganteus. Associated with the megalonyx were remains of bear, bison, deer, and horse. The collection was more notable because of the presence of a part of a human innominate bone. Dickeson affirmed that this had been taken out of the blue clay about 2 feet below three associated skeletons of the megalonyx; and it is further stated to have accorded in respect of color, density, etc., with those of the megalonyx and other associated bones. This bone is now in the collection of the Academy of Natural Sciences, Philadelphia.
In 1846 the English geologist, Sir Charles Lyell, studied the geology of the region at Natchez (Second Visit to U. S. N. A., ed. 2, vol. II, pp. 194–201). With him were Dr. Dickeson and B. L. C. Wailles, afterwards State geologist of Mississippi (Wailles, Agric., Geol. Miss., 1854, p. 213). In the yellow loam of the bluffs Lyell recognized loess deposits, from their resemblance to those of the Rhine. These he estimated to occupy the upper 60 feet of the bluff, and in them were found 20 species of land-snails, all yet living. He reported that this loess sometimes passed into a lacustrine deposit which contained shells of Lymnæa, Planorbis, Paludina, Physa, and Cyclas, and that with the land-snails had been found, at different depths, remains of the mastodon, while in clay under the loam (meaning evidently the loess) and above the sand and gravel, entire skeletons of the megalonyx had been met with, associated with bones of the horse, bear, stag, ox (Bison). Lyell noted especially the recent development of deep ravines. One of these, called the Mammoth Ravine, had been formed, he was assured, within the preceding 35 years. Its length was 7 miles and its depth 60 feet. In this ravine was found the human innominate bone referred to above. He was shown this bone, and states that Dr. Dickeson was persuaded that the bone had been taken out of the clay underlying the loam (loess). This indicates that Dickeson himself did not take out the human bone. Lyell thought that, like most of the other fossils, it had been picked up in the bed of the stream, which would simply imply that it had been washed out of the cliffs, and that it may have been dislodged from some Indian grave near the top. He (p. 197) stated that the place where the bone was found was 6 miles from Natchez. The reader may consult further Lyell’s account of his observations at Natchez in volume III of the American Journal of Science, 1847, page 266.
In 1854 Wailles (op. cit., p. 286) published a list of the vertebrate fossils which had been found in the State. This list had been prepared by Dr. Leidy. While no localities are mentioned in either publication, it is quite certain that most, if not all, of the species had been found at Natchez. Wailles (p. 285) stated that the most prolific locality was on Pine Ridge, in townships 7 and 8 north, range 3 west, 6 miles north of Natchez. While the name is not used, it is supposed that reference is here had to the Mammoth Ravine mentioned by Lyell. Leidy’s list was as follows:
Hilgard (Agric. Geol., Mississippi, 1860, p. 196, a work not issued until the early part of 1863), republished Leidy’s catalogue of species just mentioned and stated that these had been found in a solid blue clay.
In J. W. Foster’s “Prehistoric Races of the United States,” published in 1873, p. 61, is a statement made by Professor C. G. Forshey, in which he says that he visited the locality where the human innominate bone was found and that it was in Bernard’s Bayou, 2.5 miles north from Natchez. This does not accord with the statement of Wailles, who lived near Natchez and who visited the locality in company with Lyell and Dickeson. Forshey presented reasons for concluding that the bone was not derived from the Bluff formation. He stated that the mastodon bones and all others, of which there were many, were rotten, and that it was only with difficulty that any of them could be preserved. On the other hand, Leidy, in speaking of the bones of the megalonyx found in the Mammoth Ravine (Smithson. Contrib. Knowl., vol. VII, art. 5, p. 6), and of those of the Mylodon (op. cit., p. 48), says that they were in a good state of preservation.
In his work on the Lafayette formation published in 1891 (12th Ann. Rep. U. S. Geol. Surv., pp. 347–521), McGee discussed the geology about Natchez. On page 397 he presented a composite section obtained along about 3 miles of the bluff. This in a modified form is here given.
| Section at Natchez. | ||
|---|---|---|
| feet. | ||
| 7. | Loess | 10 to 50 |
| 6. | Brown loam | 10 to 40 |
| 5. | Stratified loamy sand | 5 to 15 |
| 4. | Tenacious blue clay (Port Hudson) | 10 to 15 |
| 3. | Cross-stratified sand, with pebbles | 30 to 50 |
| 2. | Stratified gravel | 5 to 15 |
| 1. | Greenish and blue clay, to above low water (Grand Gulf, Tertiary) | 5 to 10 |
McGee noted that these divisions (except the Port Hudson and Grand Gulf) are purely arbitrary, inasmuch as the character and thickness of the beds change more or less within no great distances.
He noted the fact that the loess abounded in mollusks mostly of land and swamp species; also that some of the gravelly beds well down towards the Port Hudson clays had yielded bones and teeth of elephants and mastodons.
In 1898, Dr. B. Shimek visited Natchez and studied especially the loess (Amer. Geologist, vol. XXX, pp. 279–298, with plates X-XVI). He estimated the thickness of the loess as not exceeding 30 feet. He collected from this loess more than 4,600 shells of mollusks; and these proved to belong to 39 species or well-recognized subspecies. These species are all terrestrial in habit and all are now found living either on the hills in the immediate vicinity or in similar situations in other parts of the South. Shimek came to the conclusion that the loess of that region had been deposited by the action of the winds. He was unable to find any “brown loam” above the loess, the presence of which other authors had affirmed.
Shimek found no traces of mammalian bones in the loess and was inclined to doubt that they occur there. He does not appear to have visited the locality from which most of the bones were reported.
Chamberlin and Salisbury, in 1906 (Geology, vol. III, p. 386, fig. 513), discussed briefly the geological situation at Natchez. The Natchez formation (evidently including the Port Hudson) has a thickness of about 200 feet and is made up of materials derived mostly from the so-called Lafayette, on which it there rests unconformably. In this Natchez formation are also crystalline pebbles and calcareous clays assignable to wash from the glacial regions. Between this Natchez formation and the overlying loess a marked interval is indicated. The authors are inclined to assign the Natchez deposits to the earliest part of the Pleistocene, viz, to the Aftonian and the drift epoch preceding the Aftonian. Since the time when the Natchez formation was deposited the great trench of the Mississippi Valley, about 60 miles wide, has been excavated.
Already on page 391 has been given the list of fossil mammals which Leidy made out for the State geologist of Mississippi, B. L. C. Wailles. A revision of this is here presented, with the addition of Castoroides ohioensis.
According to Lyell (Amer. Jour. Sci., vol. III, 1847, p. 268), Megatherium and Castoroides had been found in the bluffs at Natchez.
From this list of mammals it is possible perhaps to reach some conclusion regarding the geological age of the deposits containing them. In case we accept without reserve the species, 16 in number, as determined, only 3, Tapirus terrestris, Odocoileus virginianus, and Ursus americanus, are yet living, leaving about 81 per cent of the whole as being extinct, and what was called Tapirus terrestris was probably an extinct form. This alone makes it probable that the time of their existence was early in the Pleistocene. All three of the supposed existing species may, however, prove to belong to extinct species closely related to those whose names they yet bear.
Certain species may be left out of consideration because of paucity of specimens and our consequent lack of knowledge of them. These are Megalonyx dissimilis, Ereptodon priscus, and Ursus amplidens.
In case the high percentage of extinct species is not recognized as being decisive, we may consider the assemblage from another point of view. Certain species of the list appear to have existed throughout the Pleistocene, at least from the time of the first interglacial stage. These are Megalonyx jeffersonii, Mammut americanum, Elephas columbi, and Castoroides ohioensis, and their presence indicates only a Pleistocene time. Others of the list are not known to have existed after the time of the last Wisconsin drift-sheet, and may be supposed to have become extinct before that time. These are Mylodon harlani, Equus complicatus, Equus leidyi, Tapirus haysii, and Bison latifrons. All of these quite certainly existed until after the Illinoian drift period, probably into the Sangamon interglacial, except apparently Equus leidyi.
The list contains no species of primitive mastodons belonging to the genus Gomphotherium, no species of Hipparion, no camels; and Elephas imperator appears to be missing. There is, therefore, no necessity for believing that the mammal-bearing deposits at Natchez are as old as the Sheridan, or Aftonian stage, but the ancient forms mentioned may at any time turn up there or elsewhere in the immediate region.
The presence of Symbos cavifrons might be supposed to point to a rather late date in the Pleistocene; but evidence has accumulated which indicates that it reaches back farther in time than we have supposed. Taking all into consideration, the writer concludes that the fossil vertebrates found at Natchez date back at least as far as the time of the Illinoian drift stage. There is nothing to prove that they are not as old as the Aftonian stage, except the apparent absence of camels, Elephas imperator, mastodons belonging to Gomphotherium, and a multiplicity of species of Equus.
Unfortunately, vertebrate fossils, especially those known to belong to definite horizons in the Pleistocene, are, aside from Natchez, rarely found; but near Orizaba, in Tippah County, a tooth of a horse has been discovered which appears to have been Equus leidyi (p. 200). Remains of a deer (p. 234) have been found in a railroad cutting at Aberdeen, Monroe County. Mastodons are not uncommon, as may be seen on consulting the pages where these animals in Mississippi are discussed (pp. 124 to 126).
There are not many States which furnish fewer Pleistocene deposits of any considerable area than does Tennessee. Lying, as it does, away from the sea, there are no marine Pleistocene beds; situated beyond the glacial area, there are no glacial-drift deposits; and almost half of the State, the eastern, being mountainous, with rivers running in narrow valleys, there has been little opportunity for accumulation of loose Pleistocene materials. The U. S. Geological Survey has published about 25 folios describing the geology of this mountainous part of Tennessee. One will search these folios, perhaps in vain, for any mention of Pleistocene deposits and for traces of these on the maps. Now and then mention is made of narrow strips of alluvium along some of the larger rivers; nevertheless there are evidences that in some of these strips there are Pleistocene deposits. From the mountainous region westward to near Mississippi River there have doubtless been, during the Pleistocene, better opportunities for deposition of alluvium along the river courses, but such deposits have been little studied. Along the great river forming the western boundary there is a band, 10 to perhaps 25 miles in width, overlain by loess. This may attain a depth along the river varying from 20 to 70 feet, but away from the river it thins out to a feather-edge (Glenn, Water Supply Paper 114, U. S. Geol. Surv.). Up to this time, however, it has furnished few, if any, Pleistocene fossils.
Notwithstanding the paucity of Pleistocene areas in the mountainous portion of Tennessee, this region has furnished a considerable number of species of Pleistocene vertebrates, and bids fair to furnish its due proportion (fig. 23). These species occur, not in water-laid or wind-laid deposits, but in caves which abound in the limestones of that region. In 1918 (Resources of Tenn., vol. VIII, pp. 85–142), Mr. Thomas L. Bailey located and described more than 100 caves of considerable size. Many had been worked to obtain saltpeter. Bones have been reported from a few of them; probably bones had been met with in others, but were not regarded as important. In these caves (and in others yet to be discovered) may hereafter be found numerous remains of animals. Other sources for such fossils are the crevices that are sometimes opened up in quarrying operations. Caves and crevices of this kind are found in the Alleghany Mountain region from northern Pennsylvania to Lookout Mountain in Tennessee, and from them there is already known an extensive Pleistocene fauna.
Beginning in the northeastern corner of the State, a brief survey will be made of the localities and fossils which concern us. At Kingsport, in Sullivan County (fig. 23, 1) the writer has learned of the finding of a mastodon tooth (p. 127), but beyond the fact that it was owned by Mr. D. M. Lafitte, the writer has been able to learn nothing.
From Bristol, Sullivan County (fig. 23, 2), in the northeastern corner of the State, there has been sent to the U. S. National Museum a fragment of a maxilla containing two teeth of a tapir. This is referred to Tapirus haysii. No details regarding the place of discovery or of the geological conditions are known (p. 209).
From Hawkins County, at a locality not specified (fig. 23, 3) another mastodon tooth has been reported by Dr. S. W. McCallie (Science, ser. 2, vol. XX, p. 333) (p. 127). These announcements show at least that these animals could exist in those rough and elevated regions. From crevices in a marble quarry near Rogersville (fig. 23, 4), Hawkins County, there were sent many years ago to the U. S. National Museum a tooth of the horse Equus leidyi (p. 201); and a canine tooth of a very large peccary, Mylohyus setiger (p. 222). The same peccary has been secured from Cavetown, Maryland.
Fig. 23.—Localities where fossil vertebrates have been found in Tennessee.
In the U. S. National Museum is a collection of remains of vertebrate animals made about 1885 by Mr. Ira Sayles, a collector for the U. S. Geological Survey, from a point about a mile north of Whitesburg, Hamblen County (fig. 23, 5). Some masses of the matrix which contained the bones accompany the collection. This matrix is a red earth such as is often found in the floor of caves and in fissures in limestone, the result of the decomposition of the calcareous rock. Some fragments are to a great extent made up of broken bones. It is evident, however, that there is now no cave at that place. Sayles suggested that the bones were “kitchen-middens” and that there had been an old fortification there. Possibly a cave or a fissure once existed there and the rock inclosing it may have dissolved away, leaving the floor.
In this collection the writer has found the following species; these were described in 1920 (Proc. U. S. Nat. Mus., vol. LVIII, pp. 85–95, plates III, IV; text-figs. 1–3). Those preceded by an asterisk are extinct.
In this list there are 19 species, of which 8 are extinct. The latter form, therefore, 42 per cent of the whole list. This ratio appears to indicate a time about the middle of the Pleistocene. There are no forms that require an earlier date and there is good reason for believing that the horses and the tapir did not exist after the last glacial stage, perhaps not after the Sangamon interglacial.
It is interesting to find in eastern Tennessee the remains of Elephas primigenius. The discovery of teeth of this animal at Beaufort, North Carolina, in eastern Tennessee, and especially in Texas, proves that the range of that species extended even farther south in the New World than it did in the old. It is not improbable that the animal withdrew to the south during one or more of the glacial stages. However, none of the other species found at Whitesburg suggests a cooler climate than now prevails there.
It is possible that some of the forms referred to existing species are really extinct. The teeth identified as those of Odocoileus virginianus are smaller than those usually found in recent individuals. The deer Sangamona fugitiva appears in a collection made at Cavetown, Maryland, and in another made at Alton, Illinois, in or beneath deposits of loess that are believed to have been laid down about the time of the Sangamon stage.
In Jefferson County mastodon remains have been found at two places, Dandridge (fig. 23, 8) and Mossy Creek. No details are known about the first case; in the case of the tooth found 3 miles south of Mossy Creek (fig. 23, 6) it is stated that it was discovered at a depth of 6 feet and beneath a white oak stump. Between the two villages, on the left bank of Dumplin Creek, 5 miles above its mouth, is Zirkel’s Cave. From this cave (fig. 23, 7) Mercer (Dept. Amer. Archæol. Univ. Penn., 1896) reported the discovery of remains of tapir (p. 395), peccary (p. 223), bear, and small rodents; but to what species they belonged is not known. The tapir and the peccary indicate Pleistocene times. The bear probably belonged to the same epoch.
At a point 7 miles southeast of Knoxville (fig. 23, 9) Professor S. W. McCallie reported the finding of a mastodon tooth beneath 30 inches of clay. At Lookout Mountain (p. 395, fig. 23, 10) have been secured a tooth of a horse, probably Equus littoralis (p. 201), remains of tapir and probably of Mylodon (p. 43). Just where the horse-tooth was found is not known. The tapir was found in a cave on the left bank of Tennessee River, 0.25 mile below the mouth of Chattanooga Creek (Mercer, as cited above; also in Amer. Naturalist, vol. XXVIII, p. 355). Mercer’s accounts are brief and were intended only as preliminary reports. From him, through Miss Harriet Newell Wardle, of Philadelphia, the writer has received a letter in which are given some details about the investigation of this cave in 1893 and 1896.
Dr. Mercer extended his trench inward from the entrance a distance of about 50 feet and downward to the rocky bottom of the cave. He recognized the presence of three layers, as follows: (1) top layer, from 6 to 8 inches deep, containing relics of both white man and Indian; (2) middle layer, about 2 feet thick, containing evidence of Indian only; (3) red cave earth, varying from one to several feet in thickness, according to the uneven conditions of the cave floor. This latter layer was subdivided into an upper zone (a) about a foot deep, which showed evidences of intrusion of bones and refuse from the overlying layer, and (b) the undisturbed red earth which contained bones of bats and perhaps of some other animals. In the upper zone (a) of the red-earth layer Mercer found a jawbone and loose teeth of Tapirus haysii (p. 209) and a jawbone of Mylodon (p. 43) without teeth, both as identified by Professor Cope. Later, Cope became doubtful as to the Mylodon bone. In this upper zone of red earth, “within a few varying inches of the depth of the tapir specimen above or below it,” Mercer found bones of cave rats (Neotoma), marmot (Marmota), squirrel, deer, opossum, teeth and fragments of the skull of a large unidentified mammal, a small and a large bird, wild turkey, two species of turtles, frogs, and drum-fish. The skull and other bones of the large unidentified mammal had plainly been cracked to secure the marrow, and were otherwise crushed and splintered. Also, as many as 493 hornstone chips were found, besides bones rubbed to a point, and 10 potsherds. It becomes a question how the tapir bone and teeth and perhaps the bone of the mylodon and the evidences of the Indian’s presence got into this upper layer of red earth. Mercer “thought it reasonable to conclude that the tapir had been intruded into the red earth from the upper layer and had been in contact with the Indians.” This appears to indicate the idea that the tapir had existed there at a late period, probably after the Pleistocene; but the evidences appear to show that this animal lived in the United States not later than about the Sangamon stage of the Pleistocene. It is more probable that the tapir remains had not been disturbed and that the relics of man had, by some means, made their way down into the red earth. There remains also the possibility that Indians and tapirs and mylodons had lived together in that region during the middle of the Pleistocene and while the upper foot of red clay was being deposited. The presence of the other animals mentioned by Mercer does not disprove this possibility, for all of them pretty certainly existed there during the middle Pleistocene.
Not far from Elroy, Van Buren County (fig. 23, 11) there is an interesting cavern known as Bigbone Cave. This and the bones which it has furnished are now to be described.
Mercer (Proc. Amer. Philos. Soc., vol. XXXVI, pp. 36–70) found that in the greater part of this cave the nitrous earth that had formed the floor had been removed to such an extent that on the walls its stains remained at a height of one’s waist. Wherever any of this deposit remained it was exceedingly dry and any disturbance of it produced a cloud of dust. It appears to have consisted mostly of the dung and excretions of animals, such as bats and cave rats. The preservation of the cartilage and horny sheaths of the claw was due to this dryness of the atmosphere. Where Mercer found the bones he recognized four layers, to represent which he published a figure (op. cit., p. 47, fig. 4). This is here reproduced with unimportant changes (fig. 24). On top there was a layer from 2 to 3 inches thick which had resulted from the disturbance produced by the passing of white men and possibly to some extent of Indians. With the dust were mingled remains of charred vegetable substances that had been used as torches.
Fig. 24.—Diagram showing a vertical section of the gallery in Bigbone Cave near Elroy, Van Buren County, Tenn. Adapted from Mercer.
The second layer was 2 to 5 feet deep and consisted almost entirely of well-preserved dried excrements of cave rats (Neotoma) and of porcupines (Erethizon). In it were observed nuts, sticks, fur, and moss. The only animal remains found in this layer were the bones of Megalonyx (p. 42), quills and coprolites of Erethizon dorsatum, coprolites and a jaw of a cave rat referred to Neotoma magister, and jaws of two bats, Adelonycteris fuscus and Myotis subulatus (Vespertilio gryphus of Mercer). Some traces were found of an undetermined herbivorous mammal about as large as a bear. With the lot of Megalonyx bones from this cave which were described by Harlan there were remains referred to Bos (Bison), Ursus, Cervus (Odocoileus?), and a human metatarsal; but these were reported as having been picked up on the surface and may therefore have belonged to quite recent skeletons.
Besides the animal remains found by Mercer in his second layer, there were present quantities of vegetable matter belonging to several species. All, however, were forms yet living in that region.
Mercer’s third layer appears to have consisted of dry excrements which had become somewhat hardened. Its thickness was a foot. In it were found vegetable matter, some bat jaws and fur, and the carcass of a “window fly.” The fourth layer consisted of a fine water-laid clay which on drying had contracted and broken up into small angular masses. The interstices appear to have been filled by materials soaking down from the upper layers of excrement. No organisms were found in it.
Mercer concluded that the sloth remains were geologically recent, and this may be true. Megalonyx jeffersonii has been found in the northern States in deposits overlying the Wisconsin drift, and it is quite reasonable to suppose that the animal existed in Tennessee up to as late a time as it did in Ohio and Illinois. The persistence of the cartilages of the sloth, and the framework of the window fly which lay below the sloth bones, naturally suggests a comparatively short time; but if, through the dryness of the cave, they could endure a thousand years, they might possibly endure several thousand. One must consider also the length of time required for 1.5 or 2 feet of cave floor to be built up from the excrements of bats, porcupines, and cave rats, but there is no reason to refer the time back further than about the close of the Wisconsin stage.
On another page (p. 127) is presented the little that is known about the remains of two mastodons which have been reported from the region about Nashville. One tooth was found 11 miles west of the city (fig. 23, 12); a part of a skeleton at a point 11 miles southeast of it (fig. 23, 13). A tooth of an undetermined species of elephant was found long ago near Columbia, Maury County (p. 395, fig. 23, 15). According to Folio 95 of the U. S. Geological Survey, there are some narrow strips of alluvium along Duck River, at Columbia. The tooth may or may not have been found in this alluvium. Apparently in the neighborhood of Gallatin, Sumner County (fig. 23, 16), was found before 1835, at a depth of 40 feet, a tooth of an elephant (p. 181). The information furnished by the tooth, as reported, is not worth much.
In June 1920, the writer received from Mr. William Edward Myer, of Nashville, a small box of fossils, collected near Nashville (fig. 23, 14). The exact locality is given as being about 300 yards upstream from Lock A, in Cumberland River. According to a sketch sent by Mr. Myer and here reproduced (fig. 25), there are loose deposits about 30 feet in thickness lying upon bed-rock. This bed-rock is found at about the level of low-water in the river. On this rock there is found first a bed of gravel, which, to judge from Myer’s sketch, is 2 or 3 feet in thickness. Above this comes a bed of sand of about the same thickness. The rest of the 30 feet is composed of gravel; and this rises to the level of the flood-plain. In the lowermost stratum, the bed of gravel, were found a tooth of Equus leidyi (p. 201), a part of a femur of a horse of large size (p. 201), and an antler of a small and probably unnamed deer (p. 234). This antler resembles those of some of the Central American species of Odocoileus. In the next stratum above were found some indeterminable fragments of turtle bones, a tooth of a young mastodon (p. 127), and a calcaneum of a large camel (p. 225), belonging probably to the genus Camelops. In October 1920, Mr. Myer sent from the same locality a part of a molar of Mylodon harlani (p. 43). These remains appear to the writer to indicate that the deposits are of early Pleistocene age, about that of the first interglacial.
Fig. 25.—Section on Bank of Tennessee River at Nashville.
Somewhere about Memphis (fig. 23, 17), were found, about the middle of the last century, some scanty remains of a young mastodon, a bone of Megalonyx (p. 43), and a part of a lower jaw of Castoroides (p. 280). Jeffries Wyman thought that these remains had been found in diluvium of the Mississippi River. It appears probable that they were found in the loess, which is well developed at that locality. Some exactness in reporting the locality would have led to the solution of this question.
The State of Kentucky lies almost wholly south of the area of glaciation. Only along Ohio River, from about 50 miles above Cincinnati to about as many miles below, do any ice-laid drift materials appear, and these belong to the Illinoian glacial stage. For information on this drift the reader may consult Leverett’s account (Monogr. U. S. Geol. Surv., vol. XLI, pp. 256–258, plate II). Near Carrolton, between Ohio and Kentucky Rivers, is a ridge of Illinoian drift which rises as much as 200 feet above low water. Later-formed terraces of these rivers are found up to 90 feet. Not far away from this locality drift materials are found on the highlands to a height of 300 feet above the Ohio. Below Rising Sun, Indiana, on the Kentucky side, are knolls of drift deposits rising about 150 feet above the river. This Illinoian drift occupies nearly the whole of Boone County; elsewhere it forms a narrow strip along the Ohio.
Naturally there were laid down, at various times during the Pleistocene, deposits beyond the glacial front. Rivers coming down from the glaciers brought into the Ohio valley enormous quantities of gravel, sands, and clay, much of which must have been deposited along the banks or at the bottom. Such materials may have been laid down there during all or some of the earlier glacial stages, some perhaps during interglacial times. Probably at later times the most of these early deposits were swept away, but some may have persisted. The rock floor of the Ohio (Leverett, op. cit., p. 83) is below the level of the present stream, generally between 30 and 60 feet, and, at some points in its lower course, 75 feet. There might, therefore, now exist Illinoian drift materials anywhere above this rocky floor, as well as high up on the bluffs. It may be difficult, sometimes impossible, to determine the actual age of such deposits. During the whole Pleistocene, the rivers which enter the Ohio from the south were bearers of fine and coarse materials from the higher lands where they took origin. Sometimes, and in some parts of their courses, they may have occupied channels other than those now holding the waters. During times of depression of the country the sediments were dropped along the channels until the latter may have been nearly filled. Then the country may later have become elevated, so that the streams again cut down and left some of the old deposits as terraces. In some parts of the State, as in the region of Mammoth Cave, water circulating in the limestone rocks has dissolved these so as to produce caverns and fissures of various sizes. In such caves, when they became opened to the surface, animals would seek hiding-places and would perhaps bring in others as their prey. Dying there, their bones might be preserved. From such a cave has been secured a fine specimen of the skull of a peccary (p. 223). Such caves should be examined with great care.
One of the most famous localities for fossil vertebrates in this country is that known as Bigbone Lick, in Boone County, about 22 miles in a straight line southwest of Cincinnati. Fossil bones were collected there as long ago as 1739. A condensed history of the explorations made there for fossils was given by William Cooper in 1831 (Monthly Amer. Jour. Geol., vol. I, pp. 158–174, 205–216). An account of the locality, its geology, and something about the fossil vertebrates and fresh-water mollusks found there was given by the geologist Charles Lyell in 1845 (“Travels in North America,” Murray ed., vol. II, pp. 62–66).
Enormous quantities of bones and teeth, especially those of Mammut americanum, have been collected at this place. When it was first discovered, bones of this animal, of the elephants, and some others, must have been lying exposed on the surface, the result probably of erosion by the creek passing there through what was then a marsh. General William Henry Harrison, in 1795, shipped from there 13 hogsheads of bones, but these were lost on their way to Pittsburgh. Dr. Goforth is reported to have got as many mastodon teeth as a wagon and four horses could draw. These teeth are said to have weighed from 12 to 20 pounds each. If this statement of weights is true, some or all of the teeth were those of elephants. In 1807, General William Clark made a collection at Bigbone Lick, at the instances of President Thomas Jefferson. Brief notices of these were published by Dr. Samuel L. Mitchill and by Dr. Caspar Wistar. Some of these bones were sent to the American Philosophical Society at Philadelphia and were afterwards put into the collection of the Academy of Natural Sciences. Another part was sent to Paris. Remains of various species, mostly the mastodon, have gone into many museums of this country and of Europe; but it is evident that the greater part of the things collected there, and especially of the finest things, has been lost to science.
Notwithstanding the amount of work done at Bigbone Lick, the geology of the locality, and especially of the bone-bearing levels, is not well known. Most persons who have labored there were interested almost wholly in getting as many bones as possible and then in getting away. Cooper, as cited, published a map of the region and indicated where the excavations had been made up to that time. This map is here presented, redrawn (map 41). From Cooper’s account it appears that all of the bones had been found within a very circumscribed area, near a number of salt springs. The bones occurred on the surface and as deep as 25 feet. Cooper attributed this variation of depth to the unevenness of the surface, his idea being that the bone-bearing stratum occupied a certain level. He concluded that the valley had been filled up to a depth of not less than 30 feet by unconsolidated beds of various kinds, of which the uppermost was a light-yellow clay. This appeared to have been brought down from the higher grounds by flowing water. In it were found bones of buffaloes and other modern animals. Below this came a thinner layer of darker color, softer and more gravelly, which contained remains of reedy plants and fresh-water mollusks. It is described as being sometimes very thin or even wanting. It was in this layer that the bones, or most of them, were buried. It was itself underlain by a bed of blue clay of a very compact and tenacious kind. Cooper added that this bone-bearing layer appeared sometimes to be embedded in the blue clay.
The next important investigations made at this place, so far as the writer knows, are those instituted by Professor N. S. Shaler in 1868 (Geol. Surv. Kentucky, 2d ser., vol. III, 1877, pp. 196–198; Allen’s “The American Bison,” 1876, pp. 232–236). He reported that he had sent to the Museum of Comparative Zoology at Harvard at least a ton of bones. Immediately at the salt springs Shaler appears not to have been able to discover any order in the disposition of the bones. “It is only at points remote from the springs, where the beds seem to have been formed by a mixture of the creek mud and the waste from the springs, that we find the remains in the order which will enable us to form some opinion as to the succession of occurrence of these animals at this point.” At one place he thought he had succeeded in finding a distinct order of succession. Just where this place was he did not indicate, nor what kinds of deposits were passed through. The depth reached appears to have been only 8 feet. Unfortunately, the great collection made by Shaler has remained unstudied, except the remains of the buffalo (J. A. Allen, “The American Bison,” 1876, with plates).
Shaler thought that the beds of glacial drift did not extend south of Ohio River. The discovery that the Illinoian drift-sheet covers most of Boone County (Leverett, Monogr. U. S. Geol. Surv., vol. XLI, pp. 257–258) throws much light on the history of the locality. It appears rather strange that Shaler did not find rocks of far northern origin at Bigbone Lick. The geologic history appears to be something like this. When the Illinoian ice-sheet crossed the Ohio there was present the predecessor of Bigbone Creek. Inasmuch as the glacial sheet did not remain there long, a rather thin deposit was laid down in the creek. This is probably represented by the bed of blue mud mentioned by Cooper. When the glacier retired, the locality became a swamp covered probably by vegetation and receiving mud and gravel brought there by the stream and washed down from the surrounding hills. Doubtless the salt springs existed then as now and attracted thither elephants, mastodons, and other species. What were all the changes undergone there between the Illinoian and Wisconsin drift stages can not be guessed; but during the latter time, when the Ohio was carrying down vast quantities of detritus, some from the glaciated regions, some from the non-glaciated, its muddy waters were often backed up into Bigbone Creek, as they are sometimes now, and they left there the upper yellow clay described by Cooper, or at least most of it. When the Wisconsin stage had passed and Bigbone Creek was free to work in that valley, erosion began. As the creek was cutting down its bed to the present level it doubtless often changed its position, and in this way produced the irregularity of surface which both Cooper and Shaler mention.
Notwithstanding its widely extended reputation, Bigbone Lick has furnished relatively few species of vertebrates, and there is question regarding the antiquity of some of these. About the presence of Mammut americanum there is no doubt. About the presence of elephants also there can be no question; and the writer is quite certain that both Elephas primigenius and E. columbi occurred there. Undoubtedly Equus complicatus has been collected there; also Boötherium bombifrons, Symbos cavifrons, Bison antiquus, and B. bison; but it is not certain that the remains of the last-named species are not of Recent times. Shaler mentions the presence of Bison latifrons, but he probably had in mind B. antiquus. The type of B. latifrons was found in another creek valley. The occurrence of the Cervus canadensis, Odocoileus virginianus, and Alces americanus is mentioned by Cooper, who stated that he thought he had seen traces of all of them. Shaler was doubtful as to the elk. In Allen’s monograph on American bison, on page 234, Shaler admits the moose. The following is a list of the species which have been reported from Bigbone Lick. References are made to pages where further information is given on the species.
It is proper now to determine, if possible, during which of the Pleistocene stages each of these species lived. It is quite probable that none of the individual animals that have been dug up at Bigbone Lick lived there before the Illinoian glacial stage. To find such, if they have been preserved there, the excavations would have to be carried much deeper. The writer assumes that any of the animals that lived there in the interval between the Illinoian and the Wisconsin stages lived, died, and were buried during the Sangamon stage. Megalonyx jeffersonii may belong to the Sangamon or to the Late Wisconsin, for we know nothing about the depth at which the bones and teeth were secured. Mylodon harlani is not known to have existed anywhere after the Wisconsin, and hence we may refer it to the Sangamon. Equus complicatus also may with certainty be referred to the Sangamon; likewise Tapirus haysii, in case the type was not found in South Carolina. As to the cervids Odocoileus virginianus, Cervus canadensis, Alces americanus, their status is doubtful. They might go back to the Sangamon or have lived there at any time up to and during the Recent. The reindeer is most likely to have existed there during the Wisconsin ice-stage. The fine specimen of Cervalces scotti at Princeton University was found in New Jersey in deposits overlying Wisconsin drift, but it may be taken as certain that the species had existed before the time of the Wisconsin. There is no record of depth, matrix, or associated fossils in the case of the type of this species, which was found at Bigbone Lick. It is natural to refer the two species of musk-oxen to the Wisconsin stage; but there are indications that at least Symbos cavifrons has been found at other localities in pre-Wisconsin deposits. Shaler recorded it as being found near the bottom of his excavation with the horse and with the bison which he called Bison latifrons, but which is Bison antiquus. It and Symbos cavifrons probably belong to the Sangamon.
From the fact that bones of the mastodon and the two species of elephants were found by Shaler in the deeper deposits, it is probable that the individuals represented belonged to the Sangamon or some other pre-Wisconsin deposit; but, inasmuch as all three species lived after the Wisconsin, there seems to be no known reason why some of their bones may not have been buried in the late and superficial deposits at Bigbone Lick. As to the bones of the bear found at this place little can be said.
The numerous remains of Bison bison appear by all accounts to have been found only in the uppermost parts of the deposits. Shaler was of the opinion that the buffalo (Allen’s “The American Bison,” p. 234) had come to the region east of Mississippi River at a very late period, after the disappearance from Bigbone Lick of the elephants, the mastodon, and Symbos. It seems to the present writer that the presence of the existing buffalo east of the Mississippi only after the passing of the Wisconsin ice-sheet is quite certain; but that it came only after the extinction of the great proboscideans is hardly to be sustained. In many localities over the country remains of all three species have been found in swamps overlying the Wisconsin drift. In 1890 (Amer. Naturalist, vol. XXIV, p. 953), Professor Lucien Underwood described a fine skull of the American buffalo which had been found in making a sewer at Syracuse, New York. Underwood stated that it had been found in black muck, at a depth of 10 feet; but Mr. John Cunningham, superintendent of grounds at the university, who saw the place and secured the skull from the laborer who encountered it, told the present writer that the depth was 17 feet. It would seem that that bison had lived on the shores of Onondaga Lake not long after the Wisconsin glacier had withdrawn from the place.
We do not know under what geological conditions the type of Bison latifrons was found; but it pretty certainly came from post-Illinoian deposits, probably Sangamon, along possibly Woolper’s Creek in Boone County. Proboscidean remains have been reported from the Kentucky side of the Ohio in the region of Cincinnati, but it would be hazardous at present to assign them a geological age. The same may be said about the mastodon remains found in digging the canal around the falls, although the low level along the river seems to indicate the Late Wisconsin.
A collection, forming probably two farm-wagon loads, was made several years ago at Bluelick Springs, by Mr. Thomas W. Hunter. The springs having failed, Mr. Hunter undertook to dig down and restore the flow. In this he failed, but he did find great quantities of bones, mostly those of the mastodon, but also of elephants, buffaloes, and a few others (p. 129). There were about 100 mastodon teeth, many tusks, and large pieces of these; and of these pieces about 20 had been planed off so as to be flat on one or on two sides, as if they had lain in the bottom of a stream and the water and sand had worn them down on one side and then the tusks had been turned over and undergone a planing of the opposite side. Among the bones were two ungual phalanges of Megalonyx jeffersonii (p. 44), and remains of the elk (p. 243), and deer (p. 234). To none of the species found there need one assign a higher antiquity than late Pleistocene; but some might have been older. In Scott County, between Stamping Ground and Georgetown, there has been found, in the bottom of an old sink-hole, a part of a lower jaw with teeth of Tapirus haysii (p. 210). The time of existence of this animal is to be regarded as lying somewhere back of the Wisconsin glacial stage. With this jaw, Professor Arthur M. Miller sent to the writer some pieces of jaws of Tapirus haysii (p. 210) which had been found in an old stream-deposit at Yarnallton, Fayette County. From a fissure filled with calcite, at Monday’s Landing, Mercer County, there has been sent to the writer, by Professor Miller, a molar tooth of a horse (p. 202). Nothing more can be said of this horse than that it is older than the Wisconsin stage. It may be as old as the first interglacial.
About 5 or 6 miles below Henderson, on Ohio River, many years ago, considerable parts of the skeleton of Megalonyx jeffersonii were found (p. 44). With them were reported to have been discovered antlers and bones of the deer (p. 234). A description of the locality was sent to Joseph Leidy and published by him in his work on ground-sloths (Smiths. Contrib. Knowl., vol. VII, art. 5, p. 7). The bone-bed lay at an elevation of only 5 or 6 feet above an ordinary stage of low water. It was composed of a ferruginous sand and contained various species of fresh-water mollusks and stems and limbs of trees. This was underlain by a bluish clay, while above it, rising 40 or 50 feet, were beds of siliceous earth and widely spread marls. Neither the geology of the place, so far as the writer knows, nor the history of the animal requires us to believe that the geological age is beyond that of the Late Wisconsin or Wisconsin. However, a short time before, near Evansville, Indiana, at the mouth of Pigeon Creek, and apparently only about 10 miles away from where Owen found megalonyx bones, there had been discovered by Frances A. Lincke, and described by Leidy (Proc. Acad. Nat. Sci., Phila., vol. VII, 1854, pp. 199–200), a collection of vertebrate fossils. This included remains of megalonyx (p. 32), a cervical vertebra of a bison (p. 257), a vertebra of a horse (p. 186), a tooth of Tapirus haysii (p. 203), and a part of the upper jaw of the wolf known as Ænocyon dirus (p. 204). The horse was most probably Equus complicatus, while the bison was probably one of the extinct species. The wolf is regarded as being the same as that so abundantly found in the collections made at Rancho La Brea, near Los Angeles. The writer regards the fauna as belonging to the Sangamon, unless it is still older. The specimens were found sticking out of the river at low water, and it becomes quite probable that the Henderson beds and bones are of the same age as those at Evansville.
As mentioned on another page (p. 223) it is probable that the fine skull of Platygonus compressus that was sent many years ago to the Academy of Natural Sciences of Philadelphia by Dr. Samuel Brown, of Lexington, Kentucky, and described by Leidy (Trans. Amer. Philos. Soc., vol. X, p. 331, plates XXXV-XXXVII) had been found somewhere in Rock Castle County. It counts as another product of the caves which abound in the Alleghany range of mountains.