Bulletin . ide and prominent mineralized zone, revealed onthe surface by deeply altered, bold, siliceous outcroppings. .stained color by the iron oxide present. The softer parts of this rockhave been weathered out. leaving an altered material composed prin-cipally now of silica, showing in different places a great number ofphases—chalcedony, quartz, flint, and agate. At the Hernandez this 306 CALIFORNIA STATE MINING BUREAU. zone of croppings is nearly ^ mile wide, ending abruptly about 1500feet southeast of the furnace. The mine was opened in the days of the old quicksilver boom by atu
Bulletin . ide and prominent mineralized zone, revealed onthe surface by deeply altered, bold, siliceous outcroppings. .stained color by the iron oxide present. The softer parts of this rockhave been weathered out. leaving an altered material composed prin-cipally now of silica, showing in different places a great number ofphases—chalcedony, quartz, flint, and agate. At the Hernandez this 306 CALIFORNIA STATE MINING BUREAU. zone of croppings is nearly ^ mile wide, ending abruptly about 1500feet southeast of the furnace. The mine was opened in the days of the old quicksilver boom by atunnel driven northward from the southern slope a distance of 3000feet, designed to cut the ore exposed in the outcrop at depth. As faras can be learned, this work never led to any appreciable later years operations have been confined to the exploration of theoutcrop near the surface in the southeastern part of the holdings,although there are other prospects of cinnabar in the mile of outcrops. Photo No. 20. Characteristic outcrops; Los Picachos Peak, Hernandez Quicksilver Mine,San Benito County, California. embraced in the claims, which would seem to warrant prospecting. Thepresent company has been in possession since 1904, but work has beendesultory and actual progress in development small. For about fouryears up to 1916, a small yearly production of metal was made in aretort of four pipes. The ore has come from the southern and easternsides of the outcrop near the surface. Inclined shafts, one of 160 feetand two of 50 feet each, have been driven, besides which some rich orehas been taken from the face of the outcrop. The bluffs at the furnaceface southwest and stand up about 100 feet above the furnace, showingcinnabar in many plates (see Photo No. 20). The ore being treated in QUICKSILVER RESOURCES. 107 December, 1915, came partly from an incline about 45 feet deep. Thishad been sunk on a lens of ore which had a thickness of about 3 feet,width of 40 feet and ha
Size: 1746px × 1432px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectgeology, booksubjectm
