SECOND ANNUAL REPORT—STRATIGRAPHIC GEOLOGY. 147 
pieces of bone, and other organic remains are common in the basal 
portion of these sands at many localities, and their source was prob¬ 
ably the underlying formations. A rare but interesting example of 
such a conglomerate was found by Stephenson 1 at Stokes Ferry, on 
the St. Marys River. The materials comprised a shark’s tooth, a 
fragment of a mammoth’s tooth, ear bones of a whale, a fragment of 
a plate from the shell of a turtle, three horses’ teeth and indeterminate 
bone fragments. Pebble phosphates are also common in the basal por¬ 
tion of the sands of Pleistocene age. Some unsuccessful attempts 
have been made to mine them, but the deposits have usually been 
found too thin to be of economic value. Examples of phosphates of 
this character are to be found at many localities in the peninsula. They 
represent the hard materials separated from the residual clays and 
sands by the action of the waves and currents in the Pleistocene sea. 
The absence of extensive clay beds in the sands of Pleistocene age is 
due to its scarcity in the older geologic formations from which the 
sands were largely derived. This characteristic of the geological for¬ 
mations of Florida is so pronounced that good clays are comparatively 
rare, except in certain localities of limited area. 
The fossiliferous marine beds of Pleistocene age are probably more 
widely distributed in Florida than in any other State east of the Appa¬ 
lachian Mountains. Collections of Pleistocene fossils were obtained 
from the marls at Labelle, Sarasota Bay, Manatee and Six-Mile Creek 
near Tampa, on the west coast; and at Ft. Lauderdale, Eau Gallie, 
Titusville, and Mims on the east coast. In the center of the peninsula 
no exposures of the marls were found; but samples obtained by Dr. Sel- 
lards at a depth of 100 feet from the well of Capt. H. Clay Johnson, at 
Kissimmee, show that the marine marls of Pleistocene age occur at that 
locality, beneath nearly 100 feet of sand. This suggests that they 
probably extend some distance north of Kissimmee in the east-central 
portion of the peninsula. The distribution of the exposures of the 
marls over such a wide area in a region where the beds are practically 
horizontal and undissected, as is the case in the southern part of the 
peninsula, indicates that a very large area is probably underlain by 
them. Thus they doubtless extend along the western coast from 
Tampa southward to near Fort Myers. From near Labelle the inner 
margin swings northward, passing east of Arcadia and Bartow to 
some distance north of Kissimmee, and then turns eastward. On the 
east side of the peninsula the marls of Pleistocene age extend north 
to Orange City and Mims, and they may extend through the low 
valley occupied by the St. Johns River. Throughout the area where 
these beds are known they maintain striking similarity of texture, 
1 Stephenson, L. W. Unpublished notes. 
