THE ARTESIAN WATER SUPPLY OF EASTERN FLORIDA. 
87 
The Vicksburg is very characteristic in appearance and structure, 
and when once seen is not likely to be mistaken for any other for¬ 
mation in this part of the State. The first one or two hundred feet 
is of light color. This limestone as seen in well samples has a granu¬ 
lar appearance and may contain many small shells. This phase of 
the limestone is frequently spoken of by the drillers as the “coral’' 
formation. As a matter of fact, however, the formation contains 
relatively few corals. After passing through this limestone one 
or two hundred feet a more compact limestone is encountered. 
This part of the formation often has a slightly pinkish cast, the 
rock being very hard, and the drilling difficult. While these are 
the general characteristics of the Vicksburg, yet its texture is not 
uniform. Hard layers usually alternate with soft layers, the water 
supply as a rule increasing as each hard layer is penetrated. Not 
infrequently masses of flint are found imbedded in the limestone 
which in some instances have given much difficulty in drilling. 
While, as already stated, the Vicksburg limestones dip on. pass¬ 
ing to the east approaching the Atlantic, yet the dip is not uniform 
and the depth at which it is encountered varies from place to 
place. 
In the wells at Jacksonville the Vicksburg is reached at a 
depth of from 500 to 525 feet. At-Callahan and at Fernandina 
in Nassau County, although no samples ‘have been obtained, the 
Vicksburg is believed, from well records, to be reached at about the 
same depth as at Jacksonville. 
Along the St. Johns River the Vicksburg maintains a similar 
depth for some distance. At Ortega, seven miles south of Jack¬ 
sonville, the limestone was reached at a depth of about 500 feet. 
At Magnolia Springs, and Green Cove Springs, thirty miles south 
of Jacksonville, and on Black Creek, while no well samples were ob¬ 
tained, the Vicksburg is believed from well records to occur at rc 
depth of from 325 to 400 feet. 
Passing to the south the Vicksburg lies nearer the surface. 
Samples of drillings from wells at St. Augustine and at Hastings 
ill St. Johns County and at Orange Mills in Putnam County show 
that the Vicksburg in this section lies at a depth of 130 to 225 
feet, the greater depth being at St. Augustine and the minimum 
depth at Orange Mills. Passing to the south the Vicksburg lies, 
so far as well records indicate, at a fairly uniform level for a dis¬ 
tance of 150 miles. At Sanford, 75 miles south of Orange Mills t 
the Vicksburg is reached at a depth of from 113 to 125 feet- 
At Daytona, although samples are lacking, the depth of this; 
formation is believed, judging from well records, not to? ex¬ 
ceed 150 feet. At Cocoa the Vicksburg is reached at a depth not 
