^v^^^n^^^^i^H 





GENERAL DISTRIBUTION OF THE VOLCANIC FORMATIONS. 



311 



remunerative ; but, even in such cases, it would be not safe to assume that 

 the gold came from eruptive rock. At least, it would be difficult to prove 

 that it did. Not a few of the miners, however, in the early days of gold- 

 washing in California, w r ere strongly inclined to believe that all the gold was 

 thrown out from volcanic vents, and it was hoped that some lucky man would 

 discover the central point from which the precious metal had been distributed. 

 Mining has been carried on to a considerable extent, but without much 

 pecuniary success, in the volcanic formations near Silver Mountain ; but here, 

 as in the Washoe Mines, there has been little or no native 

 Ores of silver occur, which are auriferous, it is true, and a portion of the 

 metalliferous contents of the Comstock lode consists of the native metals, 

 silver and gold ; but the former is present in much larger proportion than it 

 is in the ordinary native gold of the Californian miner. 



But if the volcanic rocks themselves on the west slope of the Sierra are 

 not metalliferous, except in a few localities, may not the same agencies which 

 gave rise to eruptive phenomena on so grand a scale along the axis of the 

 range have had something to do with the formation of the quartz veins in 

 the bed-rock and their impregnation with gold? This question may be taken 

 up again for some discussion in the section devoted to the distribution of the 

 gold in the gravel ; but it may be admitted that a positive answer is not 

 easily given. 



In examining the geological features of the Sierra, we find quite different 

 conditions prevailing in different portions of the range, with reference to the 

 development of both volcanic formations and gravel. The southern portion, 

 from Mariposa southward to the extremity of the chain, exhibits hardly any 

 rocks which can properly be called slaty ; there are, it is true, several areas 

 of partly gneissoid and partly schistose rocks in the High Sierra, one of 

 which passes through Red Slate Peak, while another traverses the summit 

 of Mount Dana. It is not known that these bands, which are of somewhat 

 doubtful character and origin, have ever yielded airy perceptible quantity of 

 gold. At all events, the Southern Sierra has never, when visited by any of 

 our parties, exhibited any evidence of being sufficiently auriferous to make 

 either surface or vein mining profitable. A large amount of work has been 

 done and much money expended in the neighborhood of Kern River, whith- 

 er, indeed, there was at one time a "rush" of excited miners; but it does 

 n ot appear that anything in that region has been permanently profitable. 

 Large deposits of gravel seem to be wanting ; at least, none such have been 



