CENTEAL AND BASTEEN NEVADA. 311 



present tlirougli one tunnel, and, in effect, as one and the same mine. The 

 ledge, as it appears from the work already done upon it, is a seam or vein 

 of quartz, from one to four feet thick, and sometimes thicker, inclosed 

 in beds of calcareous shales or slates, that here form the crest of a ridge, 

 which consists mainly of quartzite or porphyritic rock. The vein crops 

 out along the hillside, and is apparently conformable with the bedding of the 

 strata, which, in general, strike northeasterly or east of north, dipping flatly 

 to the southeast; but the strike and dip of the rocks, at the point where the 

 mine is opened, are very irregular, owing to disturbances or movements to 

 which they have been subjected. Indeed the principal mining development 

 of the ledge, visible in September, 1869, has been made near what appears 

 to be the axis of a small synclinal fold in the beds, in which folding the vein 

 or ledge takes part. One of the companies was then working on one side of 

 the fold, its ore-bearing seam apparently striking north 30° west, true, and 

 dipping south 30° west, at an angle of but few degrees near the surface, but 

 increasing greatly in depth ; while the other party was at work on the oppo- 

 site side, where the strike of the seam was north 15° west, true, dipping 

 easterly, or north 75° east, at an angle of 35° ; that is, the ledge, in the two 

 places referred to, showed two varying dips, in two nearly opposite and 

 approaching directions. 



The casings of the vein, or ore-bearing stratum, are, for the greater part, 

 very distinct, and are usually accompanied by a "gouge" or selvage of clay. 

 The filling of the vein is chiefly quartz, carrying, distributed through it, par- 

 ticles or bunches of rich mineral, consisting of black sulphuret of silver, 

 argentiferous lead and copper ores, some chloride of silver, and native silver. 

 Some of the ore is very rich, averaging by assay $400 or $500 per ton ; the 

 greater part of it has an assay value of $60 or $70 per ton. The average 

 assay value of all the ore produced is stated at about $100 per ton. 



The workings of the two companies extend over several hundred feet 

 along the outcrop of the vein, and have penetrated the hill by tunnels over 

 400 feet in length. Each company was working vigorously in the autumn of 

 1869, when the mine was visited by the writer. About 45 or 50 men were 

 employed altogether, being nearly equally divided between the two compa- 

 nies. Each company was then producing between 300 and 400 tons of ore 



