76 
FLORIDA STATE GEOLOGICAL SURVEY. 
1893. Shaler, N. S.: 
Residual Ablation Deposits. (Contained in paper on “A 
Preliminary Sketch of the Phosphates of Florida,” by 
Eldridge, George H.) Am. Inst. Min. Eng. Trans. 
XXI, 1893. 
Regards the Florida pebble phosphate deposits as 
residual ablation deposits which have been moved about 
more or less by stream action. 
1893. Johnson, Lawrence C.: 
Notes on the Geology of Florida: Two of the lesser but 
typical Phosphate Fields. Am. Jour. Sci. (3) XLV, 
pp. 497-503, 1893. 
Describes phosphatic formation of Alachua County, and 
the plate rock phosphate of Marion County. Guano is 
regarded as the original source of the phosphate rock. The 
deposits of guano after removal of their soluble constitu¬ 
ents became compacted or laminated phosphate rock. The 
disintegration of the laminated rock gave rise to the plate 
rock of these deposits. Further disintegration gave rise to 
the soft phosphates. 
1893. Shepard, Charles Upham : 
The Development and Extent of the Fertilizer Industry. 
Am. Chem. Soc. Journ. XV, No. 6, June, 1893. 
Refers briefly to Florida, quoting the total phosphate 
produced by years from 1888-1892. 
1893. Wright, Carroll D.: 
The Phosphate Industry of the United States. Sixth 
Special Report of the Commissioner of Labor, Wash¬ 
ington, D. C., 145 pp, 1893. 
Pages 23 to 69 of this report are devoted to the phos¬ 
phate industry of Florida, including a general account of 
the deposits. 
