60 
FLORIDA GEOLOGICAL SURVEY-I4TH ANNUAL REPORT 
LITHOLOGIC CHARACTER AND GEOGRAPHIC DISTRIBUTION OE THE FLORIDA 
FORMATIONS 
A description of the Florida formations and much data on their geo¬ 
graphic distribution have been given in previous reports of the Florida 
Geological Survey. It -will not be necessary, therefore, to describe 
these formations in detail. It is, however, desirable to give briefly the 
lithologic characteristics and geographic distribution of each of the 
formations. These will be discussed in order, beginning with the oldest 
of the formations found exposed at the surface. 
EOCENE 
OCALA FORMATION 
The Ocala formation consists, for the most part, of a white limestone; 
rarely in Florida does this formation contain more than a limited amount 
of sand, and little or no clay. The rock is prevailingly granular in tex¬ 
ture with an abundance of small and large shells and shell fragments. 
The Ocala formation is found in two separate areas in this state. It is 
found at the surface over small areas west of the Apalachicola River, 
and may be seen in exposures on the Chipola River at and above Mari¬ 
anna and for a short distance farther down stream. The Ocala at Mari¬ 
anna is a thin formation, according to Cooke, not exceeding about 20 
feet. 
The second area in the state where this formation is found at or very 
near the surface is in central peninsular Florida. The Ocala limestone 
belt of this part of the state extends in a north-south direction through 
Suwannee, Columbia, Alachua, Marion, Sumter, Citrus and Hernan¬ 
do Counties. The formation as now understood has no great thickness, 
probably scarcely exceeding 50 feet on an average. Locally, this lime¬ 
stone has been altered by action of ground water to a compact, close- 
grained rock. In places also it contains masses or layers of flint. 
Among foraminifera, abundant in this formation, according to Cush¬ 
man, are species of Lepidocyclina, Heterostegina > Operculina and Ortho- 
phragmina. Directly under the Ocala, possibly in the Claiborne, is a 
horizon in which Nummulites is abundant. 1 The fossils of the Ocala 
formation, aside from the foraminifera, have been described by Dali 2 
and more recently reviewed by Cooke. 3 
iFla. Geol. Surv., 12th Ann. Rept., p. 96, 1919. 
2 Trans. Wagner Free Institute of Sci., Vol. Ill, pt. VI, pp. 1556-1558, 1903. 
3 U. S. Geol. Surv., Professional Paper 95, pp. 107-117, 1915. 
