WATER SUPPLY OE ^ASTERN AND SOUTHERN EEORIDA. 163 
From an incomplete set of samples from the J. R. Wilson well 
at Callahan, kindly saved by the driller, Mr. H. C. Russell, it is 
seen that limestone was encountered at a depth of from 212 to 
255 feet. The limestone was very hard and massive and no fos¬ 
sils were observed in the sample. Just above this stratum of rock 
is reported a twelve foot layer of sand and black pebbles, and in 
fact these black pebbles were seen imbedded in the underlying 
limestone. Water is reported to flow frojm this depth. Below 
this stratum of rock 100 feet of blue marl with inclusions of 
several thin strata of shells is reported. In a sample from this 
stratum the sand was gray in color and the grains were round in 
outline. The black pebbles, smaller than those in the above 
stratum, occur also at this depth but may have dropped down 
from above. At a depth of from 355 to 364 feet a very hard 
rock is reported, but no further notes were made of this and no 
samples kept. From 364 to 418 feet indurated gray sand and 
blue marl are reported and immediately below this is encountered 
a rock, apparently limestone, in which the water is reported to 
increase in head and in volume of flow as each hard layer is pene¬ 
trated. From all information that could be gathered it seems 
probable that this limestone is the Vicksburg. 
Exposures of clayey, impure limestones are found along the 
St. Marys River, at High Bluff, about six miles and at Saw Pit 
Bluff, about two miles above the Atlantic Coast Line Railroad 
bridge; also at Chalk Bluff and at Orange Bluff, near King’s 
Ferry. 
The section at Saw Pit Bluff is as follows • 
Feet. 
Sticky blue clay with some soil. 5 
Impure limestone . .. o 
At Chalk Bluff, about two miles above King’s Ferry, the fol¬ 
lowing section was observed: 
Feet. 
Sticky blue clay with some soil at top. 2 
Calcareous clay resembling fuller’s earth. 2 
White chalky material. 1 
Clay resembling fuller’s earth .,. 2 
