226 VLORIDA GI LOGICAL SURVEY--5TH ANNUAL REPORT

moved by erosion, so that the deposits known at present are merely remnants.
 In this connection it is to be noted that the white Cretaceous clays of Georgia and South Carolina are relatively free from sand and pebbles, and, with one or two exceptions, may be used without first being washed. Their properties are similar to the sedimentary kaolin of Florida, except that the Florida clay has higher plasticity.
 The immediate source of the material, i. e., clay and sand, composing the deposits in Florida, is not easy to explain. If it is assumed that the clay was derived from the white Cretaceous clays of Georgia, then another source for the quartz-sand must be sought and its mixture with the clay accounted for.
 The source of the Florida sedimentary kaolin, its transportation, geologic age, relation to other sediments, terrestrial and shore-line conditions, distribution and deposition, are problems as yet far from being !solved.
 HISTORY AND DEVELOPMENT
 The Florida sedimentary kaolin was discovered in 18901 in mining phosphates, and samples were sent to Mr. C. S. Edgar at Trenton, N. J. As early as 1875, Mr. Edgar had heard rumors of kaolin deposits in Florida, but, upon going there, was unable to find any. In 1892, Mr. Edgar began mining this clay at Edgar under the name of the Edgar Plastic Kaolin Company. This company is still operating at that place. In 1900 the International Kaolin Company began mining clay in the same formation at Okahumpka. There are at present three companies working deposits of sedimentary kaolin: The Edgar Plastic Kaolin Company, at Edgar, in Putnam County; The Lake County Clay Company, and the Florida China Clay Company, both near Okahumpka, in Lake County.

 PROPERTIES
 The sedimentary kaolin in its crude form consists of sixty to seventyfive per cent quartz-sand and twenty-five to forty per cent clay. The average is probably about sixty-five per cent sand. This natural mixture is washed, thus separating the clay from the sand, and a part, at least, of the mica. The washed product, however, probably does not represent
 1Ries, H., and Leighton, H., History of the Clay Working Industry in the United States, p. 78, 1909.