2 GEOLUGY OF THE COMSTOCK LODE. 



remarks setting forth in the briefest possibhj manner some of the most impor- 

 tant facts concerning the mines may be of interest. 



Geographical position. — Thc CoMSTOcK LoDE Hcs on the eastem slope of the 

 Virginia Range, a northeasterly offshoot from the Sierra Nevada. From 

 Mount Davidson the snow-capped j^eaks of the Sierra can be seen stretching 

 far away to the southeast, their flanks partially covered with trees; but to the 

 east and northeast lies the desert region of the Great Basin, visible through 

 the clear air for a hundred and fifty miles. Comparatively low ranges, 

 naming north and south, break the surface of the Great Basin at short 

 intervals, and as seen fi-om Virginia these appear in seemingly endless suc- 

 cession, like the waves on a stormy sea. They are clothed only b}^ the low 

 growing, gray-green desert shrubs known as "sage-brush," and every detail 

 of the mountain sculpture is visible through the vaporless atmosphere at 

 great distances. White alkali deserts appear here and there in the valleys, 

 and now and then one catches a glimpse of the Carson River, which dwin- 

 dles almost from its source, and is at last Avholly absorbed in the parched 

 earth. The Great Basin, which is five hundred miles wide, is bounded to 

 the east and west by higli ranges. During the greater part of the year these 

 mountains precipitate almost all the moisture from the air-currents passing 

 over them, and at certain stations in the Basin ordinary meteorological 

 instruments sometimes fail to show any moisture in the air. 



The parallelism of structure expressed by the disposition of the ranges 

 in California and the Great Basin finds a correspondence in the distribution 

 of metalliferous minerals, as was long since pointed out by Prof W. P. 

 Blake. The coast ranges of California carry quicksilver, coal, and chromic 

 iron. On the western slope of the Sierra Nevada is a lower belt of copper 

 deposits, and a higher and more easterly one of gold. Along the eastern 

 base of the Sierra is a zone of silver deposits, the richest known point of 

 which is the Comstock, while still farther east in the Great Basin there are 

 less sharply defined belts carrying complex silver ores and argentiferous 

 lead. 



Difficulties of mining. — Miuiug ou tlio CoMSTOCK began in 1859, and has been 

 carried on ever since, but only in spite of obstacles of the most formidable 

 character. Only the scantiest supplies of potable water existed on the spot, 



