54 
FLORIDA STATE GEOLOGICAL SURVEY. 
this formation and in the “Peninsular” limestone. Wherever the lime¬ 
stone rises near the surface, sink-holes characterize the topography, 
and the sinks form many lake basins in the central pari: of the pen¬ 
insula. (See Fig. I, pi. II, p. 58.) 
Paleontologic Characters:—Both the “Peninsular” limestone and 
the Marianna limestone are characterized by an abundant fauna, the 
most prominent fossil being Orbitoides mantelli, associated with 
Pecterv poalsoni and P. per planus. Dali 1 says that the fauna of- 
the “Peninsular” limestone includes about two hundred and twenty- 
two species, of which one hundred and two are restricted to it. With 
the imperfectly known fauna of the Ocala limestone, it has fifteen 
species in common, while nine species continue into the “silex beds” 
and limestone of the Tampa formation and two species continue into 
the Miocene and on down to the recent fauna. 
Structure:—The “Peninsular” and Marianna limestones have been 
affected bv the various earth movements which have produced the 
present structure of the State. The major structural features consist 
of broad anticlinals, such as are described under the general discus¬ 
sion of the structural features of the State. The dips are low and are 
generally seaward. Local variations in altitude of the surface of these 
limestones are so pronounced as to suggest that there has been con¬ 
siderable local warping as well as a general arching. Toward the 
southern end of the peninsula the “Peninsular” limestone dips south¬ 
ward beneath the Everglades where it is probably buried under 
hundreds of feet of younger sediments. Along the east coast there 
are marked variations in depth to this formation; but it probably does 
not rise within less than about 200 feet of the surface, and at Jack¬ 
sonville it is not less than about 525 feet from the surface. 
At Tampa, on the west coast, the “Peninsular” limestone probably 
lies somewhat more than 100 feet below the surface, but farther north 
along the coast it may be exposed. Apparently the dip of the Mari¬ 
anna limestone toward the southwest in the long western extension 
of the State is very rapid, for at Pensacola this limestone is buried to 
a depth of more than 1,100 feet beneath younger sediments. 
Local Details—As early as 1849 limestone of Vicksburg age was 
noted in Florida by J. W. Bailey, 2 who obtained some “Orbitulites” 
from a chert at Pyles Plantation, about forty miles west of Palatka. 
The exact location of the settlement where these specimens were ob¬ 
tained is not known. The same writer mentions the occurrence of 
similar rock at several points between Palatka and Tampa, but in no 
case does he give the exact localities. 
1 Wagner Free Inst. Sci. Trans., pp. 1553. 
2 Bailey, J. W., Amer. Jour. Sci., second series, 1851, vol. ii, p. 86. 
