TRANSACTIONS OF WAGNER 
VEGETATION OF SOUTH FLORIDA 
60 
clumps of coral rise to the level of low tide. Banks of solidly packed oyster- 
shells make bars at the mouths of many of the rivers, as in the case of the 
Caloosahatchee River. 
During Pleistocene age, there was a period of submarine upbuilding of 
quartz sands and calcareous material moved southward by oceanic currents. 
A depression of 30 meters (тоо feet) occurred later, during which the beach and 
bar deposits grew in thickness on the east coast and the coral reef grew and 
spread southward of the mainland. Quartz sands, calcareous sands and muds 
accumulated in the shallow water off the west coast. Following this depression, 
according to Sanford,* there was a brief uplift of the land to possibly 60 meters 
(200 feet). Beach sands were driven inland and formed dunes. The coastal 
limestone was eroded by the sea and honeycombed by rain-water. Following 
the uplift came a depression which brought the land surface nearly to its 
present level. The Everglades in recent times have been formed in the south- 
ern part of a lake larger than the present Lake Okeechobee. Sands and muds, 
and other materials, were deposited along the shores of mainland and keys and 
have contributed materially to the formation of the present shore line. 
The last element of the geology of South Florida, which concerns this 
general description, is the Caloosahatchee marl which represents Pliocene 
deposits, first discovered by Heilprin in 1887 and to which he gave the name 
Floridian. The Caloosahatchee marl is a light-gray shell-marl, often 
interbedded with nearly pure sand. It is usually very calcareous, but 
locally sand is abundant. The shells that enter into the formation of the 
marl are in a remarkable state of preservation and so easily identified. The 
thickness of the beds along the Caloosahatchee River is on the average 
about 2.4 meters (eight feet). Occupying a low level, the marl beds have 
been dissected by river action to only a slight extent. This marl includes 
all of the elevated land between Caloosa and Labelle, when with an east- 
ward dip they are finally covered by deposits of Pleistocene age. Along this 
stretch of river, there are numerous exposures of the Caloosahatchee marl 
between Caloosa and Labelle, where they have a thickness of ı meter, be- 
neath ı meter of fossiliferous Pleistocene marl covered by ı meter of 
sandy loam. 
Other localities are known along streams entering into Charlotte 
Harbor, where similar marl beds occur. Such are the Caloosahatchee beds 
* Sanford, Samuel: Second Annual Report Florida State Geological Survey, 231. 
“Ande 
