CENTRAL AND EASTERN NEVADA. 427 



highly silicified, mingled with and cemented together with quartz, spar, and 

 ore. Occasionally crystals of free quartz and, more frequently, crystallized 

 calcspar and other carbonates occur. The siliceous limestone, quartz, and spar 

 appear to be impregnated with the finely-distributed silver mineral, but the 

 richest occurrences of the latter are in the fillings of little clefts and joints of 

 the rock, in which are found seams or thin sheets of chloride of silver. Blue 

 and green stains of the carbonates of copper are abundant and are considered 

 as indications of rich ore. The length of the ore-bearing course is traced for 

 hundreds of feet. The Aurora South, at the south end of the crest of the hill and 

 overlooking the southern slope, is 800 feet long; north of that claim is the Aurora 

 Consolidated, comprising 800 feet more; nearly the whole of this ground has 

 been found rich in ore ; and beyond this, northward, other claims extend, de- 

 veloped to a much less extent but productive in some places. Its width is not 

 well defined, but the workings cover, perhaps, a hundred feet in an east and 

 west direction. The surface rock is chiefly barren limestone, which lies flatly, 

 dipping slightly to the westward, and usually forming a thin cap over the ore- 

 deposits. The latter, however, sometimes appear exposed at the surface. 



The greatest depth reached in September, 1869, was between 50 and 60 

 feet; and along the claims of the Aurora South and Aurora Consolidated 

 several large chambers, reaching that depth and extending to a greater or less 

 distance longitudinally and laterally, thus forming irregularly-shaped excava- 

 tions, had been worked out. On the Aurora Consolidated, in the vicinity of the 

 Earl shaft, the limit of the pay-ground on the west appeared to be a "floor" 

 in the limestone, striking north 25° west, true, and dipping north 25° east, at an 

 angle of about 30° from the horizon. This floor or seam was smooth, well 

 defined and regular in course and dip. The pay-rock rested upon it, but 

 apparently did not go below it ; where it had been broken through in two or 

 three places the limestone is said to have been hard, massive, and barren. 

 This floor was then regarded as the "footwall of the ledge." A corresponding 

 limit, or hanging wall, on the other side had not been found. In that direc- 

 tion the ore-bodies seemed to have irregular outlines merging gradually into 

 limestone that was either barren or too poor to pay. 



At the date above referred to the Aurora South mine was employing 

 some 60 or 70 men, taking out about 50 tons of ore per day, A large quan- 



