THE GEOLOGY OF THE COROCORO, CQPPER 

 DISTRICT OF BOLIVIA*J \ 



INTRODUCTION a , //, -' f i V ' ; -j^ 



The history of the Corocoro copper deposits in Bolivia is 

 quite prosaic in comparison with the story of the phenome- 

 nal riches that the bonanza silver districts, such as Potosi, 

 Colquechaca, or Oruro yielded. Copper is a metal that was 

 incapable of arousing the cupidity and imagination of the 

 Spanish adventurers who first penetrated the bleak and 

 inhospitable high altitudes of what is today Bolivia. Their 

 quest was the precious metals. Consequently Corocoro 

 does not share in the glamor and romance of the develop- 

 ment of the silver districts during the Colonial period. The 

 existence of Corocoro ores was by no means unknown, how- 

 ever, during this period, nor were the deposits entirely 

 neglected. Upon the arrival of the Spaniards early in the 

 Sixteenth Century they found the Indians working the 

 oxidized outcrops of the ore bodies as a source of copper 

 pigments. During the Colonial period the deposits were 

 regularly worked by a Rodriguez family who furnished 

 copper to the mint at Potosi for the national currency. 

 Revolutionary movements led to a cessation of operations 

 in 1781. A change in the character of the ore seems also 

 to have been a contributory cause. The Rodriguez had 

 mined the original outcrop ores and recovered the copper 

 by smelting ; and on encountering metallic m copper ores 

 beneath them, they were at a loss to know how to treat 

 them. 



A second period in the history of Corocoro was inaugu- 

 rated in 1830 by Claudio Rivero who began working the 

 native copper ores and who also, in that period, encountered 

 much native silver. His success attracted attention to the 



* George Huntington Williams Memorial Publication No. 10. 



