J. 
PETROLEUM POSSIBILITIES OE ELORIDA 
67 
superficial materials of the Lake Region, as a whole, represent a unit 
formation. In this map, the Lake Region is included within the map¬ 
ping of the Miocene, but this disposition is made with the reservations 
here stated. 
structural eeatures 
It is not possible with the data that has thus far accumulated to dis¬ 
cuss geologic structure in Florida in detail. However, certain major 
structural features exist which are apparent, both from the areal geology 
and from the deep-well records. 
In that part of Florida adjoining Alabama, and lying west of the 
Apalachicola River, there is evidently a structurally high area which ex¬ 
tends into Florida from Alabama and Georgia. The location of this 
area is indicated in the areal mapping. By referring to the geologic 
maps of Alabama, Georgia and Florida, it will be seen that the trend of 
the Eocene formations in Alabama is slightly south of east, bringing 
them into Florida in Holmes County. These formations lie at or near 
the surface in the northern part of Holmes and Washington Counties, 
and in the greater part of Jackson County. Before reaching the Apalach¬ 
icola River, however, the trend of these formations changes abruptly to 
about due northeast. The dip of the Eocene formations in Holmes 
County is probably southwest. The dip in the eastern part of Jackson 
County is with little doubt southeast. When this part of the state is 
contoured on the Oligocene formations, there is seen to be a very broad 
nose extending into Florida which can be traced to, or nearly to, the 
shore line of the Gulf of Mexico. (See map in Florida Survey, 11th An¬ 
nual Report, page 80, 1918.) 
With regard to Florida, east of the Apalachicola River, it will be ob¬ 
served from the mapping of the areal geology that the late Eocene comes 
to the surface in a large area in central peninsular Florida, and is then 
surrounded except on the west or gulf side by later formations. It is 
believed that the Alum Bluff Miocene formerly entirely covered the 
Eocene and has subsequently disappeared by erosion. However, the 
exposure of the Eocene indicates a true doming in this part of the state. 
A consideration of the actual position of the Eocene in this part of the 
state will reveal dips to the south, east and north from the areas of sur¬ 
face exposures, detected by well records showing the depth at which 
the Eocene is entered in wells. A dip to the west is probable, although 
