PETROLEUM POSSIBILITIES OE ELORIDA 
69 
it can not be so readily detected, since the Eocene lies at the surface to 
the Gulf of Mexico and is so massive in character as scarcely to reveal 
dips. 
In the Twelfth Annual Report, issued in 1919, the geology of Flor¬ 
ida was discussed with regard to the structural conditions in the state 
and on the map which accompanied that report are indicated the pro¬ 
nounced structural features of the state. 
A description of’a structural dome in the vicinity of Live Oak has 
been given in the Thirteenth Annual Report of this survey. The area 
lying between the Suwannee and Oeklocknee Rivers is described in this 
report under the heading Tallahassee area, and it is shown that this area, 
in the vicinity of Tallahassee, lies structurally higher than does the area 
between the Oeklocknee and Apalachicola Rivers. A remarkable fea¬ 
ture of all of the area from Tallahassee east into peninsular Florida is 
the absence apparently of the Upper Cretaceous formations and the 
near approach to the present surface of the Rower Cretaceous. 
GEOLOGIC SUBDIVISIONS 
Since the state of Florida includes a large area approximating in ex¬ 
tent 400 miles in an east-west and somewhat more than 400 miles in a 
north-south direction, it is to be expected that the formations to be 
penetrated and the drilling conditions will vary a good deal from place 
to place. Hence a discussion of the formations to be encountered and 
the drilling conditions to be expected will be facilitated by dividing the 
state into several of more or less natural geologic provinces, for 
each of which the formation and drilling conditions are more or less 
uniform. 
If we examine that part of Florida west of the Oeklocknee River, that 
is, the westward extension of Florida from near Tallahassee, we shall 
find that in extreme west Florida the Eocene and Oligocene forma¬ 
tions are deeply buried beneath later sediments, while from Walton 
County east to the Apalachicola River these formations are occasionally 
exposed at the surface. Between the Apalachicola and Oeklocknee 
Rivers the Miocene and later formations are at the surface, thus con¬ 
stituting three natural geologic divisions west of the Oeklocknee River. 
East of the Oeklocknee River and extending to the Suwannee River 
is a part of the state in which a thin remnant of the Miocene overlies 
