242 
FLORIDA STATE GEOLOGICAL SURVEY. 
With the extension of agriculture necessary to support increased 
population, together with the progressive exhaustion of the new and 
naturally rich soils there arises increased demands upon the phos¬ 
phate supply. At the present time this demand is coming chiefly from 
the older countries of Europe, and the phosphate now produced is 
largely exported. The time is not far distant, however, when an 
equally strong demand will come from the exhausted soils of our own 
country. 
CLAYS. 
PLASTIC KAOLIN OR BALL CLAY. 
The ball clays or plastic kaolins are among the most important clay 
products of the State. The Florida ball clays are white burning, highly 
refractionary and very plastic. Ries suggests that they be known as 
plastic kaolins. 1 The ball clays are used largely to mix with the less 
plastic clays to bring up the grade of plasticity. This clay as it occurs 
in Florida is intimately mixed with coarse sand. There is usually an 
overburden of a few feet of sand. This is loosened by force pumps, 
and is removed by suction pumps. The presence of the sand in the 
clay necessitates washing, after which the clay is allowed to collect in 
the settling basins. It is then compressed into cakes by which excess 
of water is removed. The cakes are then broken up and either air- 
dried or artificially dried for shipment. The deposits at present known 
lie in the central peninsular section from Putnam to Polk Counties. 
Putnam County deposits occur in and about Edgar and McMeekin. 
Deposits have been located in Lake County along the Palatlakaha (Pa- 
lalakaha) River. 2 Ball clay has also been reported from near Bartow 
Junction in Polk County, which is apparently the locality farthest south 
at which these deposits have been found. The formation holding the 
ball clay has many resemblances to the coarse or “Altamaha grit” phase 
of the red sands covering a large part of western Florida and described 
in the earlier pages of this report as the Lafayette formation. (Pages 
141-145.) 
At Edgar 4 to 10 feet of loose sand lies above the kaolin bearing 
sand. This top sand is coarse, containing siliceous pebbles up to one- 
third of an inch across. The larger pebbles are flattened and all are 
rounded. The kaolin bearing sands beneath are gray in color although 
the weathered surface is sometimes slightly iron stained. They are said 
to have a total thickness of 30 feet or more. These sands are distinctly 
cross bedded, especially the upper five feet as seen in the pit at Edgar. 
1 Clays, Their Occurrence, Properties and Uses. 1906, p. 165. 
2 Seventeenth Ann. Reprt. U. S. Geol. Surv., pt. iii (cont.) 1895-96, p. 872. 
