petroleum possibilities oe elorida 
113 
drilled in this county, although numerous wells have been drilled for 
water, ranging in depth from about 110 to 760 feet. 
MARION COUNTY 
In the western half of Marion County the Ocala limestone (Eocene) 
lies at or very near the surface. Overlying the Ocala limestone in this 
part of the county are found remnants and, in places, considerable areas 
of the Alum Bluff clays and sands (Lower Miocene). A part of west 
Marion County contains also local deposits of the Alachua clay, includ¬ 
ing sand and phosphate beds. These later deposits, the Alum Bluff and 
Alachua formations, will be found as a rule to vary from 20 to 100 or 
150 feet in thickness. 
According to studies made by Cushman, it appears that the Ocala 
limestone in this county is possibly not more than 40 or 60 feet thick. 
Underlying the Ocala, other thin limestones are found, possibly of Clai¬ 
borne age, and at no great depth Cretaceous sediments, regarded by 
Cushman as Lower Cretaceous, are entered. 
Several deep wells have been drilled in this county and the sediments 
are shown to be limestones to a depth of 1,200 feet or more. 
The eastern part of Marion County differs from the western part in 
that the Eocene limestones dip out of sight and are so deeply buried as 
not to influence the topography. Some of the springs of the county flow 
salty water. The largest of these is known as Salt Spring, near Nor¬ 
walk. The geology of the eastern part of this county has been but little 
studied. It is probable that the Miocene and possibly also Pliocene 
formations are at the surface. 
Following is the log of a well drilled at Anthony. The log is made up 
from samples preserved by the owners of the well: 
Log of well of Compagnie Generale des Phosphates de la Floride, Anthony, 
Marion County, Florida. Well drilled 1908. Water-well yield, 1,600 or 1,700 gal¬ 
lons per minute. 
Depth of sample. 
Soft, white limestone, granular, apparently Eocene. Contains many 
foraminifera and fragments of shells. % ... 50 
Possibly somewhat harder, but not materially different from above. 75-100 
Limestone of above predominates. Fragments of blue-gray like the fol¬ 
lowing are included ..... 110 
A hard, blue-gray limestone predominates in the sample from this depth. 
Some fragments of the white limestone are included. One unbroken 
piece indicates that these blue fragments are imbedded in a matrix 
of light-colored material :................. 130 
