A PRELIMINARY REPORT ON CLAYS OE FLORIDA 
211 
of three feet of sand and hardpan and five feet of blue, sandy, plastic 
clay which is underlain by marl. The clay has good working qualities 
and may be used for a good grade of common structural materials. Its 
physical properties are: 
Physical Properties of Deep Creek Clay, DeLeon Springs (Lab. No. 0 - 74 ). 
Excellent. 
Plasticity, judged by feel... 
Water of plasticity. 
Pore water . 
Shrinkage water . 
Linear air shrinkage. 
Volume air shrinkage...... 
Modulus of rupture, average 
Slaking test. 
Steel hard at cone 010. 
Overfires at cone 9. 
24.50% 
1.50% 
23.00% 
9.3 % 
32.6 % 
635.0 pounds per square inch. 
5 minutes. 
Fire tests: 
Temperature. 
Linear Shr. 
Per Cent. 
A bsorption. 
Per Cent. 
Porosity. 
Per Cent. 
Color. 
950°C. 
0.7 
12.19 
27.80 
Brick red. 
1050 
0.7 
12.80 
28.20 
Brick red. 
1150 
0.7 
10.39 
26.00 
Brick red. 
1190 
0.7 
8.26 
27.65 
Brick red. 
1230 
1.2 
7.82 
27.00 
Brick red. 
WAKULLA COUNTY 
Wakulla County, in middle Florida, is bordered on the south by 
the Gulf of Mexico and on the west by the Ocklocknee River. While the 
county is underlain by the Chattahoochee, Alum Bluff and Choctaw- 
hatchee formations, a heavy surface mantle of loose sand conceals 
them over much of the county. 
Nlo clays of importance are known in the county. A sample from the 
southwestern part of the county, submitted by S. B. Crowder to the 
State Geologist, was tested in 1920 by the Bureau of Standards. 1 The 
result of the test was as follows: 
Plasticity... Fair. 
Water of plasticity. 30.0% 
Linear air shrinkage. 12.7% 
Overfires at cone 10. 
Fired color, dark brown. 
WALTON COUNTY 
Walton County is situated in west Florida, just west of the Choctaw- 
hatchee River, and extends from the Florida-Alabama boundary to 
better from Director U. S. Bureau of Standards to State Geologist of Florida, 
August 16th, 1920. 
