66 FLORIDA GEOLOGICAL SURVEY — SIXTH ANNUL REPORT. 



World production of phosphate rock 94 



Northern Africa 94 



Tunis 94 



Algeria 95 



Egypt 95 



Continental Europe 96 



France 96 



Belgium 96 



Russia 96 



Islands of the Pacific Ocean 97 



Islands of the Indian Ocean 98 



Islands of the 'Caribbean Sea 98 



Production of phosphate rock in Florida during 1913 99 



INTRODUCTION. 



The present paper on Phosphate is largely based on the fol- 

 lowing papers prepared during the year : ( i j The Impurities That 

 Affect the Market Value of Phosphate Rock, Their Origin, Char- 

 acter, and the Methods of Their Elimination in Mining; (2) Con- 

 servation as Applied to Methods of Mining Phosphate ; ( 3 ) The 

 Phosphate Deposits of the Southern States. Of these, the first- 

 mentioned, prepared for the American Institute of Mining Engi- 

 neers, was given in abstract at the Pittsburgh meeting, October, 

 1914, and published under the title, "The Origin, Mining, and 

 Preparation of Phosphate Rock" in the September issue of the 

 Bulletin of the Institute, pp. 2379-2395, 1914. The second paper 

 was presented at a meeting of Geologists held at Knoxville, Ten- 

 nessee, September 19, 191 3, in connection with the National Con- 

 servation Exposition. The third paper was prepared for the At- 

 lanta meeting of the American Association for the Advancement 

 of Science.* Although based chiefly on these papers, the present 

 report does not include the exact reproduction of any one of them 

 except the one on the Impurities of Phosphate Rock, which is in- 

 cluded here with only minor changes from the original manuscript. 



^Abstract in Science n. s.. Vol. 39, p. 401. March 13, 1914. 



