290 E. H. SELLARDS 



Entering the Gulf of Mexico from the western slope of the peninsula 

 are a number of streams, among which are the Suwannee, With- 

 lacoochee, Hillsboro, and Caloosahatchee rivers. 



GEOLOGY 



Florida lies entirely within the Coastal Plains province and the 

 formations exposed at the surface are all of the Cenozoic era. The 

 amount of limestone in Florida is relatively large; nevertheless, a 



TABLE OF GEOLOGIC FORMATIONS IN FLORIDA 



FEET 



fPalm Beach limestone. Marine. 5- 50 



Miami Oolitic limestone. Marine. 10- 50 



I Key Largo limestone. Marine. 75-100 



Pleistocene ... "I Key West limestone. Marine. 50- 70 



Lostmans River limestone. Marine. 30- 40 



Fort Thompson beds. Marine and 



fresh water. o- 20 



Unconformity in places (at least). 



[Bone Valley formation. Estuarine. 20-100 



pi. J Alachua formation. Residual. 20-100 



1 Caloosahatchee formation. Marine. 10- 25 



[Nashua formation. Marine. 10- 30 



fChoctawhatchee formation. Marine. 30- 50 

 1^. J Jacksonville formation. Marine. Thickness undetermined 



lAlum Bluff formation. Marine; 



• [ shallow water. 50-400 



Unconformity where Miocene overlaps Eocene. 



fTampa formation. Marine. 0-130 



Oligocene ....<! Chattahoochee formation. Marine. 100-200 



[Vicksburg formation. Marine. 20- 60 



Unconformity in places (at least) . 



-p /Ocala formation. Marine. 0-50 



\Claiborne formation. Marine. Thickness not known 



Unconformity. 



Cretaceous .... Unknown. 



Comanchean . .Known only from well cuttings. 



very considerable quantity of sedimentary material, including sand, 

 clay, and flint pebbles, was carried to the south and included in some 

 of the Florida formations. The progress made in recent years in the 

 study of the geology of Florida has made necessary a number of 



