Hill sborouqh County 



Cement, followed by phosphate, oyster shell, and gems were the most valu- 

 able minerals produced. In 1967 and 1972 there were 9 and 10 establishments, 

 respectively, in the minerals industry. About 500 workers were employed in 

 minerals industries in 1967 representing a payroll of $3.1 million. In the 

 same year, mineral industries added $14.3 million to the State's economy. Of 

 the 10 establishments reported in 1972, 8 were in nonmetallic mineral mining 

 and 2 in oil and gas extraction. 



Lee County 



Limestone, oyster shells, and gems, in that order, were the most valuable 

 minerals produced. In 1972, several establishments employing between 1 and 19 

 workers were reported. Of these, 4 were nonmetallic mineral mining and 3 were 

 oil extraction. 



Manatee County 



Cement and stone were the most valuable minerals. In 1972, four nonme- 

 tallic mineral mining establishments employed between 1 and 19 workers. 



Monroe County 



Limestone was the most valuable mineral. In 1974 and 1975 mineral pro- 

 duction was reported to be $1,296,000 and $881,000, respectively. Two estab- 

 lishments, employing between 1 and 19 workers, were involved with oil and gas 

 extraction. 



Pasco County 



In 1974 and 1975, the value of mineral production (mostly stone) was 

 $611,000 and $343,000, respectively. In 1972, one establishment in nonmetal- 

 lic mining employed between 1 and 19 workers. 



Pinellas County 



In 1972, there were 18 mining establishments. Twelve were in stone pro- 

 duction and six were in oil and gas extraction. 



Sarasota County 



In 1972, two sand and gravel mineral industry establishments employed 

 between 1 and 19 workers, one establishment employed between 20 and 99 employ- 

 ees. Two establishments were in oil and gas extraction and one in nonmetallic 

 mining. 



PHOSPHATE EXPLORATION AND PRODUCTION 



HISTORY OF PHOSPHATE MINING 



Phosphate mining in central Florida dates back to the 1880' s when large 

 quantities of phosphatized vertebrate fossils were discovered along the Peace 



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