178 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT

 A clay exposed in several cuts along the St. Augustine Road in the region about Chaires and Capitola underlies an extensive area in this vicinity, but is not suited for the manufacture of burned products. A sample taken from a pit one-half mile west of Capitola, between the Seaboard Air Line Railway and the highway, has the following physical properties, which are given as illustrative of the clays of this general region: Physical Properties of the Capitola Clay (Lab. No. o-16).
 Plasticity, judged by feel........... Fair.
 W ater of plasticity................. 28.90%
 Linear air shrinkage................ 7.4 %
 Volume air shrinkage ............... 18.6 %
 Modulus of rupture, average........ 128.3 pounds per square inch.
 Slaking test ....................... 2 hours.
 Fire tests:
Temperature. LinearShr. Absorption. Porosity. Color.
 Per Cent. Per Cent. Per Cent.
 950*C. 0.1 18.30 36.20 Brick red.
 1050 0.9 18.90 36.60 Brick red.
 1150 1.4 18.58 36.10 Brick red.
 1190 1.4 17.65 34.50 Brick red.
 1230 1.9 15.30 32.50 Brick red.
 A lacustrine deposit occurs on the property of C. W. Burney, onehalf mile south of Miccosukee adjoining the Atlantic Coast Line Railroad. It is grayish-brown in color, contains some sand and is overlain by about three feet of soil. The clay is more than five feet in thickness and underlies approximately ten acres. This clay burns to a light pinkish-white at cones 010 and 05. It may be used for a fair grade of common brick, but on account of a highly-porous texture which it retains
at cone 16 a vitrified product would be impracticable. It has the following physical properties:
 Physical Properties of C. W. Burney Clay, Miccosukee (Lab. No. o-lo).
 Plasticity, judged by feel........... Excellent.
 W ater of plasticity................. 23.50%
 Pore water ........................ 0.64%
 Shrinkage water .................. 22.86%
 Linear air shrinkage............... 7.6 %
 Volume air shrinkage.............. 20.8 %
 Modulus of rupture, average........ 129.2 pounds per square inch.
 Slaking test ....................... 24 hours.
 Fire tests:
Temperature. Linear Shr. Absorption. Porosity. Color.
 Per Cent. Per Cent. Per Cent.
 950*C. 1.4 23.62 38.70 Pink.
 1050 1.4 21.00 38.60 Pink.
 1150 1.4 19.00 36.20 Brown.
 1190 1.4 15.95 33.75 Pink.
 1230 2.4 14.60 30.75 Gray.
 1910 2.4 14.20 28.60 Gray.