94 FLORIDA GEOLOGICAL SURVEY—I 4 TH ANNUAL REPORT 
Depth in feet. 
Lighter colored and runs to greenish, marly sand all through here. 
At depth 678-688 more sand. Water from 690-700. Very 
many tiny spiral shells...,.... 640 - 707 
Brown, coarse material ...:... 707 - 710 
Sand with enough marl with it to give a green color to the slush 
as ejected .... 710 - 794.6 
Loose sand, full of black specks and tiny bivalve and spiral shells 794.6 - 809 
Blue marl, full of black specks_________ 809 - 826 
Sand ............ 826 - 828 
Sandstone .......-----... 828 - 834 
Very fine, tough clay, thoroughly impervious....... 834 - 839 
Fine-grained coquina. Get dribble of water at depth of about 844 
feet 4 inches; casing driven to depth of 846 feet; tight in rock 839 - 860 
Solid, hard limestone ......... 860 - 867 
Fine clay, devoid of grit......... 867 - 874 
Hard rock __________ 874 - 876 
Lots of black specks here.......... 876 - 878 
Clays, sandy, and lots of black specks. No water..... 878 - 902 
Dark sand bed. Here the water supply is 115,000 gallons per diem 902 - 905 
Thin block of stone 909 feet, about. This is the lowest sand bed 
with thin block of limestone at intervals. Water comes from 
between these thin flakes of limestone...... 905 - 917.6 
Limestone .i.... 917.6 - 917.9 
Coralline _____________ 917.9 - 923 
Hard limestone rock at 923, solid rock nearly 39 feet.. 923 - 961 
Gritty marl ............. 961 - 973 
Solid rock .,. .'. . . ... 973 - 990.6 
Sandy marl, full of tiny spirals ........... 990.6 -1009 
Limestone ........ 1009 -1012 
Yellow sandstone .......... ... 1012 -1023 
Hard rock .. ........ 1023 -1025 
Rock, first of the regular water strata. Alternating hard and soft 
strata. Increase of water with depth. At depth of 1,042 feet, 
270,000 gallons; 1,057 feet, 300,000 gallons; 1,075 feet, 350,000 
gallons. Water strata found at frequent intervals. 1025 -1088 
Gray limestone ........ 1088 -1110 
Gray limestone, interspersed with water strata, but the flow in¬ 
creases but slightly. At 1,160 feet flow totals 400,000 gallons... 1110 -1116 
Solid gray limestone ............ 1116 -1174 
Blue limestone .......... 1174 -1175 
All solid ..,.... 1175 -1193 
Blue limestone (?) ......... 1193 -1195.6 
Six inches water stratum_______ 1195.6 -1196 
Mostly gray limestone, with some hard, and some water strata. 
Flow increases but little. 1196 -1212 
It is probable that the Eocene in this well is entered at between 915 
and 1,000 feet. (Darton, Am. Jour. Sci. XLI, p. 105, 1891.) The lime¬ 
stones beginning at 917.6 feet are probably Eocene. 
KEY WEST AREA 
Underground conditions on the Florida Keys and elsewhere in ex¬ 
treme southern Florida are known to a depth of 2,555 feet by wells 
