436 



AMAZONIA AND LA PLATA. 



TTiines were formerlv worked by the Calchaquls^ and the metal used in the 

 luanufacture of arms and agricultural implements. The first serious operations 

 of the whites date from 1804 ; but they have frequently been interrupted by 

 the civil wars, or by the high-handed proceedings of the military commanders. 



The mining region, in a pre-eminent sense, occupies the southern part of the 

 Sierra de Famatina, the richest veins lying on the crests themselves near the 

 central peaks at altitudes of from 13,000 to 15,000 and even 16,500 feet. Those 

 of La Mejicana are said to have been discovered by some Mexicans by following to 

 its source a stream charged with ochre. The limestone rocks of which these 

 mountains are formed are intersected by innumerable metallic veins, pyrites 

 of copper, gold, and silver in association with chlorine, iodine, arsenic, and 

 sulphur. 



Between 1820 and 1860 these gold and silver mines yielded £1,200,000, 



Fig. 17L — Chilecito and Famatina. 

 Scale 1 : 1.000,000. 



West oF Greenwich 



15 Miles. 



which was partly minted at La Rioja. At present operations have been extended 

 to the copper mines, in which the ores contain about one-sixth of pure metal. 

 Chilecito is connected by a branch line with the Argentine railway system, which 

 gives access to the difficult tracks running from various points over the moun- 

 tains. By one of these routes, which leads through Vincldita to the Upper 

 Vermejo valley, Chilecito maintains active relations with the mining centre of 

 Copiapo on the opposite (Pacific) slope of the Argento-Chilian Cordilleras. 



Towxs or THE Province of San Juan. 



South of Rioja follows the province of San Juan, which is also a mining 

 district, and which, like Catamarca and Rioja, lies entirely wathin the region of 

 closed river basins. <S'«/t Juaii^ the capital, is well situated at an altitude of 



