Surface 



VEINS IN THE EARLIER ANDESITE. 167 



TONOPAH AND CALIFORNIA WORKINGS. 



SECTION EXPOSED IN WORKINGS. 



The Tonopah and California shaft is situated several hundred feet southeast of 

 the Gold Hill shaft. It starts in the white stratified tuffs of the lake beds, which 

 here have a north-northeast strike and a westerly dip of about 20. According to 

 the report of the manager. 63 feet of these tuffs was passed through, and directly 

 beneath them was the earlier andesite. A short 

 distance south of the shaft the tuffs are thicker, as 

 a shaft has gone down 100 feet in them and has 

 not reached their lower limit. 



Some quartz stringers were found in the ear- 

 lier andesite beneath the tuffs, at the depth of about 

 123 feet. At a depth of about 135 feet the shaft 

 enters a brecciated zone, which consists of softened 

 and broken earlier andesite and occasional bunches 

 of broken quartz. This continues down in the 

 shaft for about -40 feet. At a depth of 150 feet a 

 short drift runs southward in this broken zone. 

 The minor slips within this zone, have a north-south 

 strike and a dip of 30 to the east, and the bottom 

 of the zone has a similar strike and dip. Below 

 this there is hard earlier andesite. rather dark col- 

 ored, with occasional north-south slips and some 

 broken quartz stringers, evidently faulted. At a 

 depth of 450 feet a drift runs in a southeasterly direction for over 220 feet. There 

 is another level at a depth of H50 feet. 



CALIFORNIA FAULT. 



The broken zone described in the shaft is evidently a fault zone. Projected 

 on the same dip to the surface, this zone coincides with the outcrop of the fault 

 which separates Gold Hill from the block in which lies the top of the Tonopah 

 and California shaft. At the surface, however, this fault zone is occupied by a 

 dike of the Golden Mountain dacite, which is not present in the shaft. Evidently 

 the dacite is straighter than the fault or happens to be missing at this point. 



According to this the shaft below the fault, that is to say, below 180 feet, is 

 in the Gold Hill block. Moreover, the east drift on the 450-foot level does not 

 run far enough to cut the fault, so that these workings are in the same block. 



FIG. 57. Cross section of Good Enough vein. 

 Gold Hill, as exposed in opening just west 

 of shaft, showing same characteristics as in 

 fig. 56. Vertical lines in andesite are joints. 



