Chapter XVII: On the Theory of the Pleistocene Terraces of the Coastal Plain (22)

From these maps it will be seen that the surface of Florida is largely occupied by Pleistocene deposits. According to Matson and Sanford, these deposits present themselves as disposed mostly in three principal terraces; and these are believed to indicate that the State was at one time largely submerged beneath the sea and that its present condition was attained after three principal upward movements. As shown on plate V of the geologists just named, the northern half of the peninsula at the time of greatest depression was represented by a number of islands, two of considerable size. One of these was situated at the northern end of the peninsula, the other near its center. The materials laid down around these islands and bordering the dry land along the northern border of the western half of the State form what is called the Newberry terrace. Its surface stands now at a height varying from 70 to somewhat more than 100 feet above sea-level. A second elevation exposed the deposits which, at least in part, constitute the next terrace, the Tsala Apopka. Its surface is a plain having an elevation of 40 to 60 feet above sea-level. At this stage the islands of the peninsula had coalesced, and the dry land extended southward nearly to the present Lake Okeechobee. A broad belt along the Atlantic and Gulf coasts, now dry land, was still occupied by salt water. A third elevation of the land left exposed the lowest terrace, the Pensacola, that bordering the Atlantic and Gulf coasts and including the southern end of the peninsula somewhat farther north than Lake Okeechobee. The elevation of this terrace varies from that of sea-level up to about 40 feet.

The materials composing the terraces in Florida are principally sand with local deposits of clays. In the southern part of the State important beds of limestone are found in the Pensacola terrace. These beds are shown on Matson and Stanford’s geological map. At St. Augustine and along the coast southward are beds of sea-shells cemented into coquina. Where cementation has not occurred there are beds of loose shells and of marl and sand.

The writer has already (p. 346) expressed his opinion regarding the Coastal Plain terraces found in the States farther north. He finds in Florida nothing to contradict, but much to confirm, that opinion. Whatever may be the origin of Newberry and Tsala Apopka terraces, they were not laid down in salt water. From the descriptions of the deposits there the stratification and the alternation of the materials do not exist that one might expect; but, above all, there seem to be no marine fossils to attest to the presence of the sea. In Florida, too, here and there over these higher lands there are found, in place of marine fossils, the remains of many extinct land animals, as mastodons, elephants, horses, ground-sloths, and the like.

As regards the Pensacola terrace, there are found at its base, within a few feet above or below sea-level, deposits containing remains of such animals as have just been mentioned, besides many others. Often the state of preservation of these remains and the condition of their burial are such that we must conclude that the animals lived and died on the spot. Furthermore, these animals constitute an assemblage corresponding to that found in western Iowa, in Nebraska, and in Oregon, which are believed to have existed during the first interglacial stage. It corresponds also to that met with under similar conditions and at the same level at Savannah, at Charleston, at Brunswick, and at Long Branch. In most cases, too, this fossiliferous stratum is overlain with very scant deposits. By some geologists and palæontologists the animals are regarded as belonging to the Pliocene.

If the reference of the fossil vertebrates mentioned is not wholly wrong, it follows that the lowest terrace or plain along the coast was not laid down late in the Pleistocene, but at an early stage, and the higher plains must have been formed at still earlier times.

At Vero, as will be shown on page 382, a large assemblage of fossil vertebrates has been secured. The bed furnishing the oldest fossils, those of the bed known as No. 2 and believed to be of about first interglacial age, is underlain by a bed of marine shells, also of Pleistocene age. This bed is regarded by Dr. E. H. Sellards as being equivalent to the coquina which is so well known at St. Augustine; and the same formation is found here and there along both coasts of the peninsula (Matson and Sanford, op. cit., p. 192). Probably not all deposits that are called coquina are of the same age, but the deposits in question pass, on the landward side, beneath the deposits which bear vertebrate fossils. The bed at Vero, No. 2, must have been laid down after an uplift had brought above sea-level the bed of shells No. 1, on which No. 2 reposes; that is, between the time of deposition of No. 1 and No. 2 there must have elapsed a considerable interval of time. The shell deposit, therefore, probably belongs to the first glacial epoch, the Nebraskan. Inasmuch as a similar vertebrate fauna is found on both the eastern and the western coasts of the peninsula, it follows that any Pleistocene deposits underlying these vertebrate-bearing beds belongs to the Nebraskan stage; in places these have great thickness. Matson and Sanford (op. cit., pp. 194–195) concluded that the maximum thickness of the Pleistocene in southern Florida, disregarding the sandhills, is probably about 125 feet. Even if it were a matter of importance to determine in or on which terraces the vertebrate fossils are found, it would not always be easy to do so. The majority of specimens have been discovered around the coasts of the State, and therefore in deposits referred to the youngest terrace. In other cases it is difficult to determine the terrace in which fossils are buried, partly because of imperfect records as regards locality, kind of deposits, and depth of burial, partly because each terrace extends up the river valleys beyond its general border. The various fossil-bearing localities will therefore be taken up by counties, beginning at the western end of the State and ending at the southern end.

_Jackson County._—As already recorded on page 121, a tooth of _Mammut americanum_ has been found at Marianna. No details have been recorded. The Newberry terrace extends nearly or quite to this town. If it could be shown that this tooth had been buried in that terrace when it was formed, it would probably have to be referred to the time of the first glacial stage.

_Gadsden County._—It appears that no vertebrate remains belonging to the Pleistocene have been found in this county, except a tooth of _Mammut americanum_ (p. 157) which was discovered somewhere in Little River.

_Wakulla County._—On page 157 the finding of a tooth of _Elephas columbi_ somewhere along St. Marks River has been mentioned; also the discovery of a part of a skeleton of either a mastodon or an elephant somewhere about Wakulla Springs.

_Columbia County._—A mastodon tooth has been found in this county 3 miles northwest of Fort White (p. 121). To which terrace it belonged or what is its place in Pleistocene time it is impossible to say.

_Nassau County._—At Stokes Ferry have been found some teeth of an extinct horse (p. 194), a fragment of a tooth of an elephant (p. 180) and some ear-bones of a whale. Veatch and Stephenson (Bull. 26, Geol. Surv. Georgia, p. 394) report that these appeared to come from either the Charlton formation or the Satilla. If the Charlton really belongs to the Pliocene it is not probable that the fossils were derived from it; if they were derived from the Satilla, they do not belong to late Pleistocene.

_Duval County._—On page 106 of the Eighth Annual Report of the Florida Geological Survey, Sellards reported the finding of remains of _Mammut americanum_ (p. 122), _Elephas columbi_ (p. 157), an undetermined species of _Bison_ (p. 262), and an undetermined species of _Odocoileus_ (p. 232), near Pablo Beach, at station 120 on the Inland Waterway Canal. Here, too, has been discovered a bone of _Trachemys? nuchocarinata_. Sellards stated that the position of the beds here is the same as that of the other localities along the Atlantic coast, the fossils being found in sand and muck which rest upon Pleistocene shell-marl. The locality is, of course, on the youngest terrace; but that, in the opinion of the writer, belongs to the early Pleistocene.

_St. John’s County._—At a place 28 miles south of St. Augustine, along the Inland Waterway Canal, Mr. Fred P. Allen, of St. Augustine, collected on the Almero farm remains of _Mammut americanum_ (p. 122), _Elephas columbi_ (p. 158), _Mylodon harlani?_ (p. 37), _Equus_ sp. indet. (p. 194), the box-tortoise _Terrapene antipex_, and a dermal plate of perhaps _Alligator mississippiensis_. These were found in the banks of the canal. Here, at least, the horse and the mylodon, taking into consideration the geological circumstances, indicate early Pleistocene, equivalent to the first interglacial stage.

_Levy and Alachua Counties._—Geologically these counties furnish important localities because of the presence of the Alachua clays (usually referred to the lower Pliocene or even the Upper Miocene) and deposits belonging to all three of the Pleistocene terraces, Newberry, Tsala Apopka, and Pensacola. The Alachua clays first require consideration, for in them have been found a considerable number of species of vertebrates which usually indicate Pleistocene deposits. The localities where Alachua clays have furnished vertebrate fossils, as indicated on Matson and Sanford’s map (Water Supply Paper 319, U. S. Geol. Surv., plate I), are situated, one around Archer, Alachua County (the type locality), second, about 5 miles west of Williston, in Levy County, and a third about 5 miles east of Newberry, in Alachua County.

The clays referred to form accumulations in depressions on the surface of the Ocala limestone, itself belonging to the Eocene. The deposits are said to average in depth about 10 feet, but are often thinner and occasionally much thicker. They have furnished a considerable number of species of vertebrates. A list, prepared by Dr. Leidy, of those found at Archer was published in 1892, in Bulletin 84 of the U. S. Geological Survey, on page 129. Besides these, Leidy had previously reported a tapir, a small crocodile or alligator, and a bone thought to belong to the extinct _Cervus americanus_ (_Cervalces scotti?_), but which was not afterward mentioned. The rhinoceroses and the camels were described by Leidy and Lucas in 1896 (Trans. Wagner Free Inst., vol. IV, pp. 1–61 with plates).

Herewith is presented a list of such vertebrates as have been found at Archer. It appears necessary to retain for the rhinoceroses the specific names given them by Leidy.

Gomphotherium floridanum (p. 121). Odocoileus osceola? (p. 232). Procamelus major (p. 224). P. minor (p. 224). P. minimus (p. 224). Teleoceras proterus (p. 211). Aphelops longipes (p. 211). Tapirus haysii? (p. 207). Hipparion ingenuum (p. 195). Megatherium mirabile (p. 37). Alligator (or Crocodylus) sp. indet.

The following vertebrates have been collected east of Williston, in the place mentioned in Dall’s report of 1892, on page 129, as Mixon’s:

Gomphotherium floridanum (p. 121). Procamelus major (p. 224). Teleoceras proterus (p. 211). Hipparion ingenuum (p. 196). Hipparion plicatile (p. 196). Thinobadistes segnis (p. 37). Manatus antiquus?. Pseudemys cælata. Atractosteus lapidosus.

The list from the locality east of Newberry (Hallowell’s place of Dall’s report) is rather short. _Equus littoralis_, _Odocoileus osceola?_, _Hipparion_ sp. indet., and _Parahippus_ sp. indet. have been reported (Rep. Florida Geol. Surv., vol. V, p. 58; vol. VIII, pp. 42, 94). At Neals, Alachua County. _Tapirus terrestris?_, _Gomphotherium floridanum_, and _Hipparion_ sp. indet. have been collected (Sellards as cited). At Juliette, same county, _Gomphotherium floridanum_ has been secured, and at Hernando the same species; also _Hipparion_ sp. indet. and _Procamelus_ sp. indet. (Sellards Florida Geol. Surv., vol. V, p. 58). Along Santa Fe River, in the Buttgenbach mines, 6 miles north of Wade, have been found teeth of _Equus_ and a tooth of _Bison_.

At Dunnellon, about 25 miles south of Williston, from the phosphate mines along the Withlacoochee River, have been obtained fossil vertebrates so similar to those found in the Alachua clays that Sellards concluded to unite his Dunnellon formation and the Alachua clays into one to be called the Alachua formation (6th Ann. Rep. Florida Geol. Surv., p. 161). The list of vertebrates found at and about Dunnellon is as follows, including the species dredged in Withlacoochee River:

Megalonyx sp. indet. (p. 38). Chlamytherium septentrionale (p. 138). Ursus sp. indet. Felis sp. indet. *Gomphotherium floridanum (p. 122). Mammut americanum (p. 122). Elephas imperator (p. 162). Trichechus manatus. *Parahippus sp. indet. (p. 196). *Hipparion plicatile (p. 196). Equus leidyi (p. 196). Tapirus sp. indet. (p. 207). *Aphelops longipes (p. 211). *Procamelus minor (p. 225). Odocoileus osceola (p. 233). Bison sp. indet. (p. 263).

The species marked by an asterisk are regarded by Doctor Sellards and others as belonging to the Miocene or Pliocene (8th Ann. Rep. Florida Geol. Surv., p. 94). See also Sellards, 1913 (5th Ann. Rep. Florida Geol. Surv., p. 58; 8th Rep., p. 104).

On the basis of the fossil vertebrates it can hardly be denied that the Alachua clays and the phosphate mines at Dunnellon are of the same geological age. According to Sellards, the formation belongs to the upper Miocene or to the lower Pliocene. Merriam (Bull. Dept. Geol. Univ. Cal., vol. X, p. 439) refers it to the Pliocene. Although there is present a strong palæontological element which represents the Pleistocene, the reference of the formation to the late Miocene or early Pliocene has seemed to be required by the presence of _Gomphotherium_, _Procamelus_, _Teleoceras_, and _Hipparion_. The Pleistocene species are usually accounted for on the supposition that they are intrusions from more recent deposits.

A figure from Sellards (Geol. Surv. Florida, vol. VII, p. 53), only slightly modified is intended to show the relation of the phosphate-bearing formations to those underlying them (fig. 21).

It is worth our while to consider whether or not the reference of the Alachua formation to the Miocene or early Pliocene is required by palæontological evidence. _Gomphotherium_ is characterized by having molar teeth which on abrasion at one or both ends of each crest, present a trefoil pattern of the enamel; also by having a band of enamel on each of the upper tusks. Now, teeth having the same structure are not uncommon in deposits of undoubted Pleistocene age in Kansas and Texas. That the animals possessing these teeth had tusks with enamel bands is not known, but it is quite possible that such enamel bands were present.

FIG. 21.—Diagrammatic sketch of geologic structure of Florida from
north to south passing through the hard rock and pebble phosphate
fields, showing relation of the phosphate deposits to the underlying
formations. After Sellards.
]

1. Georgia-Florida State line.

2. Suwannee River.

3. Lake City.

4. Santa Fe River.

5. Withlacoochee River.

6. Lakeland.

7. Arcadia.

8. Caloosahatchee River.

9. Gulf Coast.

_a_ Upper Oligocene phosphatic marls.

_b_ Ocala limestone.

_c_ Hard rock phosphate.

_d_ Bone Valley formation.

_e_ Pleistocene deposits (Pliocene and Pleistocene of Sellards).

The genus _Hipparion_ is not confined to the Tertiary. Teeth have been discovered in the Aftonian of Iowa (Hay, Geol. Surv. Iowa, vol. XXIII, p. 150) and in Missouri (op. cit., p. 149). The writer has described a species of the genus, _Hipparion cragini_, collected by Professor Cragin in the Sheridan beds in Kansas (Kansas Univ. Sci. Bull., vol. X, p. 42).

One may be justified in suspecting that _Procamelus_ lived on into the Pleistocene. Not only has it been found associated with Pleistocene fossils in five places in Florida—Archer, Williston, Dunnellon, Hernando, and Ocala—but it has been met with in possible Pleistocene deposits (the Idaho formation) in Idaho, which furnishes _Equus_, _Cervus_, _Castor_, and _Stegomastodon mirificus_ (the type of which belongs in the Sheridan beds). Furthermore, the writer has had occasion to describe a collection of fossils, believed to belong to the early Pleistocene, which was obtained at Anita, Coconino County, Arizona. Among these fossils are two species of _Procamelus_ much like those described by Leidy from the Alachua formation (Proc. U. S. Nat. Mus., vol. LIX, pp. 622–626). The writer believes that the genus _Procamelus_ persisted into the early Pleistocene.

Two species of rhinoceros have been collected in the Alachuan formation, _Teleoceras proterus_ Leidy and _Aphelops longipes_ Leidy. Both occurred at Archer, while _T. proterus_ was found near Williston and _A. longipes_ at Dunnellon. A rhinoceros has been discovered in the Idaho formation, with the Pleistocene species named above in connection with _Procamelus_ of these beds. In Oregon Cope made a collection which has been examined by Dr. W. D. Matthew (Bull. Amer. Mus. Nat. Hist., vol. XVI, p. 321). Here again _Teleoceras_ was supposed to have been found with _Hipparion_, camels belonging to _Camelops_ (or _Procamelus_), _Elephas_, and _Equus_. Matthew thought that there had happened, either before the fossils were collected or afterwards, a mingling of elements of two distinct faunas.

To the writer it seems improbable that the commingling of _Procamelus_ and the rhinoceroses with Pleistocene forms should occur thus accidentally so often and at such widely removed localities. It appears more probable that these Tertiary genera did not become extinct so early as has been supposed and that the association was not a secondary one. The association is what might be expected in collections made in deposits of the earliest Pleistocene.

It must not be forgotten in these discussions that the Pleistocene genera and species with which the collections in question are being compared are those of the so-called _Equus_ beds, which appear to represent the fauna of the first interglacial stage. This, however, was preceded by the Nebraskan, the first glacial, which probably occupied a long period of time; possibly it was half as long as all the rest of the Pleistocene (Chamberlin and Salisbury, Geology, vol. III, p. 383). About the vertebrate life of this long stage we know as yet very little. The writer is quite convinced that the Idaho formation and the Alachua, or Bone Valley, belong to the earliest Pleistocene.

_Marion County._—In a fissure in the limestone-rock quarry at Ocala there has been found an important collection of vertebrates. The following list is thought to include all that have been reported:

Trucifelis floridana. Sylvilagus sp. indet. Elephas columbi (p. 158). Bison sp. indet. Odocoileus sp. indet. (p. 233). Procamelus minimus (p. 224). Tapirus sp. indet. (p. 207). Equus leidyi (p. 196). Dasypus sp. indet. (p. 38). Terrapene formosa. Testudo distans. T. incisa. T. ocalana.

A part of this list was published by Sellards in 1916 (8th Ann. Rep. Florida Geol. Surv., p. 103). The tortoises were described in the same volume.

Inasmuch as _Trucifelis floridana_ has been found in the Pleistocene at Vero, Florida, one may safely regard the specimen found at Ocala as also of Pleistocene age. All of the other mammals are admitted to be of Pleistocene age except _Procamelus minimus_. The fissure may have been open during some part of the Nebraskan stage.

_Volusia County._—At Daytona, situated on the east coast, therefore on the youngest terrace, remains of _Mammut americanum_ (p. 122) have been found. At DeLand there has been recovered the skull of a dolphin which Sellards (8th Ann. Rep. Florida Geol. Surv., p. 107, plate XIV) has described as _Globicephalus bœreckii_ (p. 20). It was found at a depth of 10 feet, in sands which overlie Pliocene shell marls. The sands are regarded as belonging probably to the Pleistocene. DeLand is on the Tsala Apopka terrace. At a depth of 10 feet there was reached the supposed marine base of this terrace.

_Orange County._—As stated on page 196, a tooth of an extinct horse was found somewhere in the county.

_Pinellas County._—On the western shore of Tampa Bay (p. 159), near St. Petersburg, at Indian Rock, a tooth of _Elephas columbi_ was found.

_Hillsboro and Manatee Counties._—The region around Tampa Bay is important because of the wealth of vertebrate fossils dredged up by the collectors of phosphate rock from the beds of Hillsboro, Alafia, and Manatee Rivers. Unfortunately, few accurate records have been kept of localities and conditions of occurrence of the fossils, and we usually know only that a collection was made in a certain river, perhaps not so much as that. For that reason it is concluded to group together all the fossils regarded as Pleistocene and known to have been found in Hillsboro, Manatee, and Sarasota Counties. In order to indicate as far as possible the localities, the names of the species are followed by contractions which apply as follows.

A, Alafia River. E, Ellenton, on Manatee River. Hc, Hillsboro County. Hr, Hillsboro River. Ls, Little Sarasota Bay. Ps, Palma Sola. M, town of Manatee. P, Palmetto. S, 8 miles southeast of Sarasota. T, around Tampa Bay. Wb, White Beach, on Sarasota Bay.

_List of Pleistocene vertebrates found in Hillsboro, Manatee, and
Sarasota Counties._

Homo sapiens, Ps. Elephas imperator, P (p. 164). E. columbi, T, S, Ps (p. 159). E. primigenius, Ps (p. 145). Mammut americanum, T, He, A (p. 123). Bison latifrons, Ps (p. 263). B. sp. indet., T, A, P, Ps (p. 263). Odocoileus sp. indet., P, Ps (p. 233). Tapirus sp. indet., T, A (p. 208). Tagassu lenis?, Ps (p. 222). Equus complicatus, A, Wb, Ps (pp. 196, 197). E. leidyi, A. P, Wb, Ps, S (pp. 196, 197). E. littoralis, M, Ps (p. 197). Chlamytherium septentrionale, Hr, Wb, S (p. 38). Testudo crassiscutata?, A. T. ocalana, He. Terrapene putnami, A. Deirochelys floridana, He. Trachemys euglypha, E. T. jarmani, Hc. T. sculpta, Hc. Pseudemys extincta, Hc. P. cælata, Ps. Platypeltis ferox, Hc.

The bones of man belonged to the skull and are as completely fossilized as the bones of a horse and are wholly free from organic matter.

Among the mammals of this list there are no genera and few species that have not been found in the Pleistocene at many places in the United States. The presence of _Elephas imperator_ and three species of _Equus_ and _Chlamytherium_ apparently indicate Pleistocene of about Aftonian times.

From Palma Sola, Manatee County, there have been sent to the U. S. National Museum by Mr. Charles T. Earle many specimens of fossil vertebrates, found at various times washed up on the beach. Some belonged evidently to deposits older than the Pleistocene, probably to Miocene, and included teeth of sharks, a beak of a platanistid porpoise, and a lower tooth of a sirenian, _Metaxytherium floridanum_. Other specimens, as bones of a camel, parts of the shells of tortoises, alligator or crocodile teeth and bones are of uncertain age. Ten species of the list are referred to the Pleistocene. All of the teeth are isolated, but many are well preserved and little water-worn. The bones are mostly fragmentary, some worn, some not.

_Polk County._—On page 159 is an account of a tooth of an elephant. _Elephas columbi_, reported as being found at Kingsford, Polk County, under 19 feet of phosphate rock and sand. It may belong to _E. imperator_. On page 196 is detailed the finding of several teeth of _Equus_ in the phosphate mines of Kingsford. The species _E. leidyi_ and _E. littoralis_ are recognized. Unless these elephant and horse-teeth had been incorrectly reported or had been secondarily introduced into the phosphate beds, they are, in the writer’s opinion, to be referred to the first glacial stage, the Nebraskan. Dr. W. H. Dall has somewhere reported the finding of tusks at Bartow; these were supposed to have belonged to _Elephas columbi_ (p. 180). At Nichols the large land-tortoise _Testudo hayi_ Sellards has been recovered from a phosphate mine. From phosphate mines at Brewster has been secured the following list of vertebrates, obtained from Dr. Sellards’s reports (Florida Geol. Surv., vol. VII, pp. 100, 106, 108; vol. VIII, pp. 95, 96, 98, 100).

Gomphotherium floridanum? (p. 123). Mammut progenium (p. 123). Hipparion minor (p. 197). Procamelus minor? Teleoceras or Aphelops sp. indet. (p. 211). Agriotherium schneideri. Tomistoma americanum.

All of this list are referred by Sellards to the upper Miocene or lower Pliocene. The writer regards them as belonging to the first stage of the Pleistocene.

From a phosphate pit at Christina, Sellards (Florida Geol. Surv., vol. VII, p. 106, fig. 35) has reported a tooth of an undetermined species of Gomphotherium.

Sellards (Florida Geol. Surv., vol. VII, pp. 72, 110) has reported the collection of remains of _Hipparion_ sp. indet. and of _Teleoceras proterus_ (p. 211) from phosphate mines at Mulberry. In the U. S. National Museum are undetermined remains of _Gomphotherium_ from the same place, sent in by Matson.

_Brevard County._—In the Hopkins drainage canal at Eau Gallie have been found remains of _Equus complicates_ (p. 196) and _Elephas columbi_ (p. 159).

_Zolfo, Hardee County._—At Zolfo, near the border of the Bone Valley area, have been found _Megatherium_ (p. 38) and _Elephas columbi_ (p. 160).

_De Soto County._—With one exception, apparently, fossil vertebrates have been discovered in De Soto County only in deposits along Peace Creek. The exception is a place called Tourner’s or Turner’s, on Caloosahatchee River. The elephant found there will be considered among the fossils found in Lee County. At Calvenia, at the entrance of Charlie Apopkee Creek into Peace Creek, _Equus leidyi_ (p. 198) has been secured.

Most of the fossils found below Calvenia are accredited to Arcadia. According to Leidy (Trans. Wagner Inst., vol. II, p. 19), those of his list were found on a sand-bar at Arcadia; but certainly others have been taken from phosphate rock dredged both above and below the town. As complete and as accurate a list as the writer has been able to prepare is here presented.

Peace Creek, or Peace River, has been the source of many fossil vertebrates, the greater part of them obtained at or near Arcadia. Most of the species were described by Joseph Leidy in 1889 (Trans. Wagner Free Inst., vol. II, pp. 19–31). The region was examined by Dr. W. H. Dall, whose report was published in 1892 (Bull. 84, U. S. Geol. Surv., pp. 128–133). He referred the bed bearing vertebrate fossils to the Pliocene. Cope (in Dall’s report, p. 130) regarded them as equivalent to the _Equus_ beds of the Great Plains, or between these and the Loup Fork. Sellards (Florida Geol. Surv., vol. VII, pp. 78–83) places the formation in the Pleistocene.

_List of fossil vertebrates found in Peace Creek at or near Arcadia._

Elephas imperator (p. 164). E. columbi (p. 160). Mammut americanum (p. 124). Bison sp. indet. (p. 264). Odocoileus osceola? (p. 233). Tapirus terrestris (p. 208). Equus leidyi (p. 199). E. littoralis (p. 199). Hipparion ingenuum (p. 199). Delphinid sp. indet. Trichechus antiquus. Glyptodon petaliferus (p. 39). Glyptodon rivipacis (p. 40). Chlamytherium septentrionale (p. 40). Megalonyx jeffersonii (p. 39). Alligator mississippiensis?. Testudo crassiscutata. T. obtusa. Trachemys euglypha. Macrochelys floridana. Chætodipterus faber. Diodon sp. indet. Myliobatis sp. indet. Galeocerdo sp. indet. Isurus sp. indet.

Of all the genera and species of mammals and reptiles appearing in the list, there is none that it is necessary to suppose was derived from Pliocene deposits, or even from those of a Pleistocene stage earlier than the first interglacial. The marine fishes and sharks have been derived possibly from the Arcadia marls. On the other hand, the presence of _Elephas imperator_, the species of _Equus_, _Hipparion_, _Glyptodon_, _Chlamytherium_, and the gigantic tortoise _Testudo crassiscutata_ furnishes evidence that the age was about that of the _Equus_, or Aftonian, beds of the Great Plains.

_St. Lucie County._—At Fellsmere, a place near the northern border of the county and about 10 miles west of Indian River, teeth of both _Elephas columbi_ (p. 159) and _Mammut americanum_ (p. 122) have been found, in the construction of drainage canals.

The most important locality for Pleistocene fossils in St. Lucie County, one may say in the whole State, is Vero. The topographical, geological, and palæontological conditions found here are described in the Eighth and Ninth Annual Reports of the Florida Geological Survey. Papers on the subject may be found also in the Journal of Geology for January 1917 and for October 1917; also in the American Anthropologist for the first and second quarters of 1918. Besides the large number of species of vertebrates found here, the interest is heightened by the fact that, associated with these, are human bones and objects of human manufacture. Through the valley of an insignificant stream was dug a large drainage canal, the construction of which brought to light vertebrate bones and teeth. Three beds of Pleistocene materials were exposed. At the bottom is found a bed of marl filled with marine mollusks and which is the geological equivalent of the coquina rock at St. Augustine. The same deposit is found in various places along the coast and has received from Dr. Sellards the name Anastasia formation. Above this lies a stratum composed mostly of sand, but containing also some muck. In the discussion of the locality this bed is designated as No. 2, the marl being No. 1. No. 2 has a thickness of about 2 feet. It in turn is overlain by No. 3, which consists mostly of vegetable matter and sand. It is called also the muck-bed. In places the muck is replaced by a bed of marl, which here and there may become pretty firmly consolidated. The thickness of No. 3 is about 2 or 3 feet. Vertebrate fossils are found in both No. 2 and No. 3. It is the purpose of the author first to present lists of the fossils which have been found in each of the upper beds, beginning with the stream of sand, No. 2.

_List of fossil vertebrates found at Vero in stratum No. 2._

Trucifelis floridanus. Felis veronis. Ænocyon ayersi. Vulpes palmaria. Lutra canadensis. Procyon lotor. Cryptotis floridana. Blarina brevicauda peninsulæ. Sylvilagus sp. indet. Neofiber alleni. Hydrochœrus robustus. Sigmodon sp. indet. Elephas columbi (p. 159). Mammut americanum (p. 122). Bison sp. indet. (p. 263). Odocoileus osceola? (p. 233). Camelops? sp. indet. (p. 235). Tagassu lenis (p. 222). Tapirus haysii? (p. 208). T. veroensis (p. 208). Equus complicatus (p. 199). E. leidyi (p. 199). E. littoralis (p. 199). Dasypus sp. indet. (p. 38). Chlamytherium septentrionale (p. 38). Megalonyx jeffersonii (p. 38). Mylodon harlani (p. 39). Didelphis virginiana. Jabiru weillsi. Cathartes aura. Querquedula floridana. Herodias egretta. Alligator mississippiensis. Testudo sellardsi. Terrapene innoxia. Chelydra laticarinata.

_List of fossil vertebrates found at Vero, in stratum No. 3._

Lynx ruffus floridanus. Canis riviveronis. Canis sp. indet. Vulpes palmaria. Lutra canadensis. Ursus floridanus. Procyon lotor. Scalopus aquaticus australis. Sylvilagus palustris. Neofiber alleni. Neotoma floridana. Sigmodon hispidus. Oryzomys palustris. Elephas columbi (p. 159). Mammut americanum (p. 122). Odocoileus osceola? (p. 233). O. sellardsiæ (p. 233). Bison sp. indet. (p. 263). Tagassu lenis (p. 222). Tapirus haysii? (p. 208). Equus littoralis? (p. 199). E. leidyi? (p. 199). Chlamytherium septentrionale (p. 38). Dasypus sp. indet. (p. 38). Didelphis virginiana. Ardea sellardsi. A. herodias. Ardea? sp. indet. Herodias egretta? Aluco pratincola. Cathartes aura septentrionalis. Larus vero. Larus? sp. indet. Mycteria americana? Alligator mississippiensis. Crotalus adamanteus. Farancia abacura. Drymarchon corais couperi. Gopherus polyphemus. Terrapene antipex. T. innoxia. Pseudemys floridanus persimilis. Trachemys? nuchocarinatus. Chelydra sculpta. Chelonia mydas. Caretta caretta. Siren lacertina. Amphiuma means. Caranx hippos. Caranx sp. indet. Amiatus calvus. Lepisosteus platystomus. Aëtobatis narinari.

Besides those remains which are to be assigned with certainty to one or the other or both of the strata, there are a few others about whose place in the deposit there is uncertainty:

Testudo luciæ. Gopherus præcedens. Trachemys bisornata. T. sculpta.

At a point about 3 miles west of Vero, a lower jaw of _Elephas imperator_ (p. 163) was found in the bank of the drainage canal. It was embedded in a matrix of brown sand which rests upon the stratum of marine shell marl.

The list of mammals found in stratum No. 2 shows that there are 29 species and that 21 of these are extinct. This high proportion of species no longer existing is of itself enough to show that the deposit is an old one. Again, such species as _Elephas imperator_ and camels occur in the glaciated region only in Aftonian beds, and outside of the glaciated region only in those which are quite certainly of approximately the same age.

In the list of species found in stratum No. 3 there are 25 mammals, of which 12 species are extinct. These form, therefore, 48 per cent of the whole, indicating apparently a more recent geological time, perhaps about the Sangamon stage. It is true that the geologists hold that there has been continuous deposition and that no interval elapsed between the laying down of No. 2 and No. 3. In a region so near to the level of the sea, where the streams are small and short and have little fall, deposition must have gone on with extreme slowness; hence there may have been no period when deposition ceased. Apparently, too, there was a time when the region was somewhat lower than at present and salt water came up the stream as far as the locality where the fossils are found. The presence of _Chelonia mydas_, _Caretta caretta_, the two species of _Caranx_ and _Aëtobatis narinari_ may thus be explained.

The fresh-water and terrestrial mollusks of stratum No. 2 were submitted to Dr. Paul Bartsch, of the U. S. National Museum, who has reported on them (Rep. Florida Geol. Surv., vol. VIII, p. 144). He lists 29 species, all living.

The marine mollusks found in the stratum called No. 1, and which the writer refers to the first glacial stage, have been studied by Mr. W. C. Mansfield, of the U. S. Geological Survey (Rep. Florida Geol. Surv., vol. IX, pp. 78–80). Seventy-four species are specifically determined, and of these 61 are identical with living forms. Three or four species are possibly extinct. There is no question that the deposit belongs to the Pleistocene.

Nearly all of the plants were found in the bed designated as No. 3, the upper or muck-bed. These were studied by Dr. Edward W. Berry, of the Maryland Geological Survey. His report, published in 1917 (Rep. Florida Geol. Surv., vol. IX, pp. 19–33), states his conclusion that the plants belong to the late Pleistocene, either the Peorian or the Late Wisconsin. It may be stated that Dr. Berry adopts the theory that the terraces supposed to be found along the Atlantic Coast were formed during stages of submergence beneath the sea, the lowest one late in Pleistocene time.

_Lee County._—The whole of Lee County is occupied by Pleistocene deposits which form a part of the Pensacola terrace. Naturally the Pleistocene is overlain, generally, at least, by accumulations of Recent materials, and it may not always be easy to distinguish the one from the other. So far as the writer knows, all the vertebrate fossils discovered in this county have been collected along Caloosahatchee River above Fort Myers. The geology of this river has been described by Heilprin (Trans. Wagner Inst., vol. I), Dall (Bull. 84, U. S. Geol. Surv., pp. 142–145), Matson and Sanford (Water Supply Paper 319, pp. 134–138), Sellards (2d Ann. Rep. Florida Geol. Surv., p. 123, 6th Ann. Rep. Florida Geol. Surv., pp. 41–46). The Pleistocene is underlain by Pliocene marls and hard and soft limestones and consists of beds of muck, marl, and sand of little thickness. At Labelle it is said (Sellards, 2d Ann. Rep., p. 126) that there is a fossiliferous Pleistocene marl covered by 3 feet of sandy loam. The following seem to be the species which have been found in the Pleistocene in this region:

Elephas imperator (p. 163). Equus leidyi (p. 199). E. sp. indet. (p. 199). Bison latifrons (p. 264). Mylodon harlani (p. 40). Testudo obtusa?. Trachemys bisornata. T. sculpta.

The presence of _Elephas imperator_ is an indication that the deposits belong to the early part of the Pleistocene. None of the species appear to indicate an older stage than the Aftonian.

_Dade County._—Sellards (8th Ann. Rep., p. 106) records that some fragmentary remains of a proboscidean had been found in Miami River, Dade County.

_Palm Beach County._—On page 105 of the report just cited, Sellards stated that _Elephas columbi_ (p. 160), _Mammut americanum_ (p. 123), _Equus complicatus_ (p. 200), and _Bison_ sp. indet. (p. 264) had been found in the Palm Beach Canal, constructed to drain the Everglades.

At some unknown point in the Everglades, possibly in Lee County, there was found many years ago a tooth of an elephant which the writer believes belonged to _Elephas imperator_, already mentioned on page 163. It was formerly reported as _E. columbi_.

ALABAMA.

An account of the Quaternary formations of Alabama may be found in Eugene A. Smith’s “Report on the Geology of the Coastal Plain of Alabama.” This was published in 1894, and the part pertaining to the Pleistocene is found on pages 28 to 65. Along the coast Smith recognized the presence of a formation which he called the Biloxi. The upper part of this was regarded as belonging to the Recent, while the lower portion was thought to be the equivalent of Hilgard’s Port Hudson, those deposits numbered 1 to 4 in the section shown on page 387, under Geology of Mississippi. The thickness of the Port Hudson is given as about 100 feet. Borings revealed the presence of shells and lignitized wood.

Along the rivers which traverse the Coastal Plain are found three terraces. The first or lowest is that which is subject to annual overflow. The second terrace, “the second bottom,” occurs along most of even the smaller streams of the Coastal Plain. It may be as much as a mile wide. The height above low water may vary from 10 to 15 feet in the lower courses of the rivers to 60 feet farther up stream. Near water-level a blue clay is frequently found which contains stumps, roots, and other remains of vegetation, often well preserved. Smith concluded that this second terrace was the substantial equivalence in time to the Port Hudson.

Smith presents a geological section taken along Black Warrior River, in Hale County, 150 miles above Mobile. The section included about 50 feet. As caving went on, stumps and logs were frequently brought into view. Similar sections were found on Coosa River, above Montgomery, and on Alabama River, 50 miles above Mobile.

The third terrace is found at elevations of from 50 to 100 feet above the second. It is sometimes 3 miles or more in width.

In his paper on the Citronelle formation (Prof. Paper U. S. Geol. Surv., 98, pp. 167–208), Matson discusses briefly (pp. 189–190) the Pleistocene of the area studied by him. This extends from the western end of Florida to Mississippi River. Here he recognized four terraces, from the youngest to the oldest, the Pensacola, the Hammond, the Port Hickey, and the St. Elmo. The St. Elmo merges into the Natchez formation, which Matson, quoting Chamberlin and Salisbury, regarded as sub-Aftonian. The Port Hickey terrace is stated to take its name from a locality on the Mississippi River where the typical materials of the Port Hudson formation are exposed. The Port Hickey terrace may, as suggested by Matson, be of post-Iowan age. Naturally, these correlations require confirmation.

Berry has described fossil plants (Amer. Naturalist, vol. XLI, pp. 689–697; Amer. Jour. Sci., ser. 4, vol. XXIX, pp. 387–398) which were found along Chattahoochee River, not far below Columbus, Georgia; on Warrior River, up to 356 miles above Mobile. Pleistocene deposits must occur along all the larger streams still farther north, and these deposits will yield in time bones and teeth of vertebrated animals.

Notwithstanding the considerable area of Pleistocene deposits discovered in Alabama, the number of species of vertebrates met with is remarkably small. On page 40 is recorded the finding of _Megalonyx jeffersonii_ somewhere about Tuscumbia. At Newbern, Hale County, have been found an incisor tooth of a horse (p. 200) and a molar of a bison (p. 264). At Bogue Chitto, Dallas County, have been collected _Equus leidyi_ (p. 200), _Mammut americanum_, and _Elephas imperator_. The last species indicates that the deposits probably belong in the Aftonian. The writer knows of no other localities in the State where vertebrate fossils of the Pleistocene have been obtained.

MISSISSIPPI.

(Text-figure 22.)

The geological history of the lower part of the Mississippi Valley during Quaternary times appears to be particularly difficult to understand and at present is far from being unraveled. It is easy to see that such a region will offer great difficulties. Here debouches into the ocean a majestic river which drains not only the glaciated portions of the United States from western New York to northwestern Montana, but the larger part of the region south of this from the Blue Ridge to the Rocky Mountains, and brings down every year enormous quantities of sand and silt, which are dropped partly on its flood-plain, but mostly near its mouth. Through the ages during which this has been proceeding, this river has been ever changing its bed, sometimes eroding away one bank, sometimes the opposite one; so that its flood-plain is, in most places below the mouth of the Ohio, many miles wide, varying, according to Russell (“Rivers of North America,” 1898, p. 267) from 5 miles to 80 miles in width. During the Quaternary there have been also elevations and subsidences of the bed at least from Cairo northward, as a result of which at one epoch the current was hastened and the valley cut out deeper; at another the current was checked, the channel clogged up, and the river forced to seek a new channel or even new temporary or permanent outlets to the Gulf (E. A. Smith, Geol. Surv. Alabama, 1894, pp. 30–34).

To get a correct idea of the Pleistocene geology of the lower Mississippi region, one must understand the situation at the beginning of this epoch. I. C. Russell, on page 267 of his work just quoted, calls attention to the differences displayed by the valley of the river within the glaciated region and that south of it. South of the mouth of Ohio River the wide flood-plain of the Mississippi lies from 300 to 500 feet below the general level of the bordering uplands. He states further that the hard rock bottom of the valley is only imperfectly known, but that the records of wells and borings show that an ancient valley has been filled with alluvium to a depth of at least 100 or 200 feet in its northern part and to an increasing depth southward. If to this thickness, given by Russell, we add the depth, 300 to 500 feet, which the flood-plain occupies below the bordering uplands, we get a measure of the depth of the great trench which once existed where now lies the flood-plain of Mississippi River. In his paper on the underground waters of southern Louisiana (Bull. 1, Louisiana Geol. Surv., 1905, p. 42, plate II) Harris presents the record of the Fabacher well, which was bored at New Orleans. At a depth of about 1,200 feet fossil remains were brought up which appeared to be of Pleistocene age. It is evident from these facts, as in the case of those obtained from the rivers of Texas, that at about the beginning of the Pleistocene, or more probably during the time of the so-called Lafayette, at the close of the Pliocene, the country east of the Rocky Mountains, at least, stood for a long time at a much higher level than at present and that, as a result of this elevation, there was an enormous general erosion of the face of the country and a great widening and deepening of the river valleys. This time of elevation was quite certainly followed by a prolonged period of depression, during which these canyon-like trenches and their tributaries, up to their last ramifications, were nearly completely refilled. This refilling must have occurred during the early stages of the Pleistocene, for in the materials are buried the bones of early Pleistocene animals. As quoted below, in considering the geology at Natchez, Chamberlin and Salisbury state that since the Natchez formation, 200 feet thick, was laid down, the trench of the Mississippi, 60 miles wide, has been excavated. One might change this expression and say that it had been re-excavated, but not to its original depth.

When we reflect that the greater part of the sediments which, during the Pleistocene epoch, were deposited at the mouth of Mississippi River and on its flood-plain from Kentucky southward, were certainly derived from the glaciated portions of its great valley, and that those regions were alternately affected by the events of five glacial and four interglacial epochs, we must conclude that corresponding deposits or phenomena of some kind exist throughout the valley. The matter is, however, so complicated that many years must elapse before a satisfactory solution will have been reached.

In his Report on the Geology and Agriculture of the State of Mississippi, 1860 (1863–65), the geologist E. W. Hilgard, on pages 5 to 46, described under the name of Orange sand a deposit which characterizes the greater part of the surface of that State. He referred this to the Quaternary and regarded it as being the southern equivalent of the northern drift. This formation is now believed to belong mostly at least to the Pliocene. Besides the Orange sand, Hilgard (op. cit., pp. 194–201) referred other formations to the Quaternary. These in order would be as follows, the latest above:

5. Modern alluvium.

4. Second bottom, or Hommock deposits.

3. Yellow loam deposits.

2. The Bluff formation.

1. Orange sand.

The Bluff formations were described as occupying a narrow belt along the borders of the Mississippi bottom in northern Mississippi and along the river itself in the southern part of the State. He stated that the fossils belonged to terrestrial species, and quoted Leidy’s list of vertebrates, already mentioned, remarking that the blue clay which furnished them was said to belong to the Bluff formation. He reported that the snails found in the Bluff formation seemed all to belong to living species. The yellow loams occupied a large part of the surface of the State, overlying the Orange sand and forming a great part of the soils of the State. The succeeding formations were found along many of the rivers.

In 1869 (Amer. Jour. Sci., vol. XLVII, pp. 331–346), Hilgard reported the results of a geological reconnaissance of Louisiana. In this he proposed the name Port Hudson group for extensive deposits of clays which were especially well displayed at Port Hudson. This formation was further described by Hilgard in 1872 (Smithson. Contrib. Knowl., vol. XXIII, No. 248, p. 5). Two geological sections taken near Port Hudson were presented, one of which is here reproduced.

_Section midway between Port Hudson and Fontana._

6. Yellow loam, sandy below 8–10 5. White and yellow hardpan 18 Orange and yellow sand, sometimes ferruginous sandstone, irregularly stratified 8–15 4. Heavy greenish or bluish clay 7 3. White indurate silt, or hardpan 18 2. Heavy green clay with porous calcareous concretions above, ferruginous below; some sticks and impressions of leaves 30 1. Brown muck with cypress stumps 3–4 White or blue clay with cypress stumps

The cypress stumps of No. 1 were numerous and well preserved.

The writer reproduces Hilgard’s geological map of the lower Mississippi region, in which is represented the distribution of the Port Hudson according to that writer’s views (fig. 22). It will be seen that it was supposed to pass eastward into the coast region of Mississippi, Alabama, and Florida. Westward from Atchafalaya River it was believed to occupy a large part of southern Louisiana and to pass into Texas and around the Gulf coast to near the Rio Grande. It will be observed that in the latter State it corresponds in a general way to what has been called by Deussen the Lissie formation.

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.