Table 4. — Quantities of iron, total phosphorus, and copper discharged by Florida west coast tributaries 



[Metric tons] 



I All values of <0.1 in computation toward the total were not used; instead, actual values were used. 



Table 5. — Explanation of the legend for figure IS 



^K^^tiMtTOl 



TTtT 



Figure 12. — Surface phosphate-bearing formations of 

 the west coast of Florida (after Cooke, 1945). See table 

 5 for explanation of legend. 



Geological formation 



Caloosahatchee marl. - 

 Bone Valley formation . 



Suwannee limestone, . 



Buckingham marl. _ _ 



Lake Pleistocene deposits. 



Lake Flint marl 



Ft. Thompson formation- 

 Tampa limestone. . . 



Hawthorne formation. - 

 Citronelle formation- 



Composition 



Predominantly sand and shell marl, 

 Pliosphatic, sandy clay and gravel. 

 Composition; 55-79% bone phosphate. 

 Hard and resonant. 

 Composition: 91-98% CaCOj; chief impurity, 



silica. 

 Impermeable calcareous clay containing small 



grains of phosphatic material. 

 Marine and cstuarine deposits less than 30.5 



meters above sea level. 

 Calcareous fresh-water marl. 

 Marine shell marl and fresh-water limestone. 

 Fairly hard and dense, Contauis a large portion 



of very fine sand and phosphate. 

 Composition: 74% calcium carbonate; <24% 



silica; trace magnesium carbonate, 

 Sandy, phosphatic limestone, jmd green 



phosphatic clays, 

 .''and, gravel, and clay. The clay is kaolin when 



mixed with sand or gravel and is commonly 



iron stained. 



through Biickinghani marl formation (mainly 

 impermeable calcareous day containing only 

 small grains of phosphatic material). 



INORGANIC PHOSPHATE-PHOSPHORUS 



The monthly changes ami areal distribution of 

 inorganic phosphate-phosphorus in all rivers were 

 similar to those of total phosphorus (figs. 2-11). In 

 So percent of the observations, inorganic phos- 

 j)hate-phosphonis exceeded organic and was re- 



472 



U.S. FISH AM) WILDLIi'K SERVICE 



