70 FLORIDA GEOLOGICAL SURVEY-I5TH ANNUAL REPORT


 C. Transported clays.
 I. Deposited in water.
 (a) Marine clays or shales. Deposits of great extent.
 White-burning clays. Ball clays.
 Fire-clays or shales. Buff-burning.
 Impure clays or shales Noncaareous.
 (b) Lacustrine clays. (Deposited in lakes or swamps.)
 Fire-clays or shales.
 Impure clays or shales, red-burning.
 Calcareous clays, usually of surface character.
 (c) Flood-plain clays.
 Usually impure and sandy.
 (d) Estuarine clays. (Deposited in estuaries.) Mostly impure and
 finely laminated.
 II. Glacial clays, found in the drift, and often stony. May be either red or
 cream-burning.
 III. Wind-formed deposits. (Some lesss)
 IV. Chemical deposits. (Some flint clays.)
 (a) Replacement deposits.
 (b) Chemical deposits.

 Grout and Soper' have used the physical properties as a basis of classification and refractoriness the basis of subdivision. It is as follows
 I. Refractory (above cone 27). Uses.
 (a) Earthy, usually residual, non-plastic....................China clay.
 (b) Plastic ......................................Ball clay.
 (c) Flint-like, non-plastic....................................Fire clay.
 II. Semi-refractory (above cone 10).
 (a) Safely vitrifying.
 Red burning............................... .......Paving Brick.
 Buff or Cream-burning................................Stoneware.
 (b) Rapidly fusing ................................Low-grade fire clay.
 III. Non-refractory (below cone 10).
 (a) Safely vitrifying.
 Red-burning................................. Drain tile.
 IFoundation brick,
 Vitrified brick.
 Buff or cream-burning................. 1Fountain and sewer brick.
 (b) Rapidly fusing......................................Common brick.
 Note-Subdivisions of II and III may be made on the basis of degree of plasticity, or some other physical character.

 Recently Parmelee2 has proposed a classification which is based on the uses of clays according to their physical properties. Parmelee points



 'Grout, Frank F., and Soper, E. K., Preliminary Report on the Clays and Shales of Minnesota, Minn. Geol. Survey, Bull. 11, p. 18, 1914.
 2Parmelee, C. A'., Further Investigation of Illinois Fire Clay, Bull. 38, II. Geol. Survey, p. 10, 1921.