TRANSACTIONS OF WAGNER 
VEGETATION OF SOUTH FLORIDA 
56 
islands, and coral reefs with inlets, lagoons, and reéntrant bays. In other 
places, the smooth shore line has long sweeps and easy curves.* 
Although the surface of South Florida shows slight relief, the average 
elevation not over 6 m. (20 feet), its general slope is south, with a slight tilt 
to the west, as is demonstrated in a study of the drainage of water from Lake 
Okeechobee and the Everglades. A depression of 15 m. (50 feet) would en- 
tirely submerge this portion of the State and an elevation of 15 km. would 
make dry land of the bottom of the Bay of Florida, and Biscayne Bay and 
would extend the coast line 60 km. (forty miles) west of the entrance to Shark 
River and twenty miles to the west of Cape Romano. During the Pleistocene 
and recent history of southern Florida, there have been no great disturbances 
marked by elevations or depressions of the land surface, although slight oscilla- 
tions of the surface in an up and down direction are indicated. The forces at 
work have been those concerned with the growth of coral reefs, their wasting 
away, the movement of sand, the formation of bars and the filling of shallow 
bays by sedimentation largely consequent upon the growth of mangrove 
trees, and through the agency of other vegetation in open lakes and swamps. 
GEOLOGY 
The logs of deeply driven wells in South Florida show that deposits of 
the Oligocene, the Miocene, and the Pliocene ages are buried beneath super- 
ficial strata, which alone concern us in this account, because the upper 
exposed strata alone are influential in the formation of soil in which plants 
grow. The deposits of Pleistocene age exposed to the action of the ele- 
ments comprise limestones, coquina and sands. The limestones are 
found in the form of bare ridges, or scattered outcrops, while the coquina 
lies along, or back of, the east coast line, and the sands cover the surface of 
the greater part of the southern portion of peninsula. The superficial lime- 
stones are classified as Palm Beach limestone, Miami-Key West oölite, Key 
Largo limestone, and Lostmans River limestone. 
The Palm Beach limestone is a non-oólitic marine limestone found as 
inconspicuous outcrops scattered sparsely through the pineland, cypress 
swamps, and prairies along the eastern side of the Everglades from Delray 
* Gulliver, F. P.: Shoreline Topography. Proc. Amer. Acad. Arts and Sciences, xxxiv, No. 
8, 1899. 
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