PERU. 



267 



the ores of the Cerro are ferruginous, and the silver nearest to the 

 surface is contained in an ochreous iron-stone. In particular spots the 

 silver is found mixed with lead and copper, and at variable depths in 

 different localities the ores rest on a bed of solid iron pyrites, which in 

 some mines yield silver and in others not 



BXAX ©T TJk 



Although there appeared to be two veins, crossing each other at 

 right angles, yet strictly speaking there is but one, the great vein of 

 Colquijirca. This vein comes in from the hill of Uliachim, on the south 

 of the town, and runs through the whole metalliferous ground to the 

 edge of the plain of San Juan on the north. 



On the course of this lode, generally speaking, the richest ores are 

 met with. On each side of the vein an extensive deposit of ore is 

 generally found, with little regard to the ordinary regularity of metal- 

 liferous formation. 



The plain of San Juan is divided into many mining districts, to which 

 names are given to distinguish them more readily. The southernmost 

 of these is called Zauricocha, and contains several mines, from which 

 great wealth has been produced since the revolution. This is the region 

 from which all the richest ores have been produced, and it has been 

 always looked upon as the most important district in the Cerro. It is 

 believed that farther south, between this point and the hill of Uliachim, 

 some good ores exist; but no attempt has yet been made to mine there. 



