TRANSACTIONS OF WAGNER 

 56 



VEGETATION OF SOUTH FLORIDA 



islands, and coral reefs with inlets, lagoons, and reentrant 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 oolite, Key 

 Largo limestone, and Lostmans River limestone. 



The Palm Beach limestone is a non-oolitic 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. 



