168 SILVER-LEAD DEPOSITS OF EUREKA, NEVADA. 



area on the surface it is very likely that it may extend underground into 

 Adams Hill. If this is the case, it has very likely been the source of the 

 ore in the mines of that region. If it has been the source of the ore it is 

 probable that the quartz has also been derived from it through the decompo- 

 sition of its silicates. 



Mining. — The ore of this region is usually of very good quality, but the 

 rock is frequently hard and it is extracted with some difficulty. The mines 

 have been opened by individuals and small companies, and they have not 

 been sufficiently explored to determine either their permanency or their 

 future value. Just at present there is not very much mining going on in 

 this part of the district, but there seems to be no reason for believing that 

 the deposits do not extend to considerable depth, and it is to be hoped that 

 the decreased cost of mining and of reduction which inevitably follows the 

 increasing age of a mining camp will cause the revival of this industry. 



