128 
FLORIDA GEOLOGICAL SURVEY-I4TH ANNUAL REPORT 
ferred. In the southwestern part of the county on the Choctawhatchee 
River, the Alum Bluff formation lies at the surface. This county is lo¬ 
cated on the structurally high area of west Florida. The deepest well 
so far drilled in Florida is within this area, about four miles south of 
Chipley. Samples of the cuttings were saved at five-foot intervals, and 
the information which they afford will become available in time. 
GENERAL CONSIDERATIONS 
In estimating the probabilities of petroleum production in any local¬ 
ity, it is necessary to take into consideration the structural features and 
the character of the underlying sediments. 
With regard to structural features in Florida, it may be said that there 
are pronounced structurally high areas of regional extent in the state, 
among which are the Marianna-Chipley Area, the Tallahassee Area, 
and the central peninsular Florida geanticline or dome, and in addition 
the somewhat isolated doming at Live Oak. It is probable that struc¬ 
tural features favorable to the accumulation of oil exist within these 
areas, and may exist elsewhere. 
When the character of the underlying rock is considered, it is found 
that in central peninsular Florida the rocks at one locality in Sumter 
County, to a depth of 3,090 feet, and to 2,555 feet on Key Vaca, Monroe 
County, have been shown to be chiefly limestones and marls, with rela¬ 
tively little or no bituminous matter. It is, however, possible that the 
sediments in some other localities in central peninsular Florida may be 
found to be more favorable than they appear in this one well, although 
such conditions have not yet been revealed by drilling. The age and 
characteristics of the formations underlying the Cretaceous in Florida 
has not been determined, a$ no wells in the State, so far as known, have 
reached or passed through the base of these formations. 
In western Florida the sediments in Washington County were found 
to be somewhat bituminous and may reasonably be expected to produce 
oil under favorable sand and storage conditions. 
With regard to locations for test wells, it would appear, in a state 
where but little prospecting has been undertaken, that if tests are to be 
made those areas in the state that are shown to present regional high 
structures should be selected for the first tests. The location of such 
regionally high areas has been indicated in this report. 
