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:
- Felis atrox Leidy.
- Ursus americanus fossilis.
- U. amplidens Leidy.
- Equus americanus Leidy.
- Cervus virginianus fossilis.
- Bison latifrons Leidy.
- Boötherium cavifrons Leidy.
- Elephas primigenius.
- Tapirus americanus fossilis.
- T. haysii Leidy.
- Megalonyx jeffersonii Harlan.
- M. dissimilis Leidy.
- Mylodon harlani Owen.
- Ereptodon priscus Leidy.
- Mastodon giganteus.
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.