Mines and Mineral Resources of Sierra County: By Errol MacBoyle (Google eBook)

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California State Printing Office, 1920 - Mines and mineral resources - 144 pages
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Page 25 - ... SCALES. In the description of the Bidwell Bar quadrangle (p. 100) the main channel is traced from Poverty Hill at Scales down to Camptonville, with an average grade of 100 feet to the mile, the smallest grade, 60 feet to the mile, being recorded from Poverty Hill to the Rock Creek outlet at Scales, where the channel has a general southerly direction and is filled with quartz gravel to a depth of 120 feet.
Page 30 - ... assumed importance. SIERRA COUNTY DEPOSITS. In the Poker Flat district, in township 21 north, range 10 east, John B. Lassiad owns a claim showing a copper deposit about 60 feet wide, carrying pyrites, oxides, and carbonate of copper. Bassett's Pride Claim. — About five miles east of Sierra City. Some native copper shows in the deposit, in which a tunnel has been driven. This mine is in section 12, township 20 north, range 12 east, and is owned by Albert Church et al. Near Sierra City, in section...
Page 112 - The mine is developed by a 200' crosscut tunnel, then 3800' of drifting on the vein. This is called No. 4 or lower tunnel. At 2300' from the portal there is a 330' winze with level No. 5, 113' below, then 135' to No. 6, then 80' to No. 7. On No. 6 level 500' has been drifted NW.-SE., on No. 6 drifts run 130' east and 460
Page 103 - The thickness varies from a maximum of 15" to practically nothing, the usual width being about 2". The quartz is distinctly banded and in places approaches comb structure. It contains nests of little pyrite crystals, accompanied by specks of sphalerite and galena. Free gold is found where the stringers from the foot-wall intersect the vein. The gold is in the quartz near the sulphides and is very commonly smeared out along slips in the vein. A rare occurrence of gold was seen in the presence of minute...
Page 11 - Company drifted on the channel between Hepsidam and Bunker Hill, a distance of about a mile. The channel at Hepsidam between rims was 800' wide, of which 500' to 600
Page 112 - ... Standard (13.22 acres), Standard Extension (19.25 acres), Enterprise (17.54 acres), Marion (20.36 acres) and Plumbago Millsite (3.64 acres), a Total of 132 acres. It is situated on the south side of the divide between Kanaka Creek and the Middle Fork Yuba River. Work has been carried on at intervals since before 1860, and the production is said to have amounted to several millions. A total of 55 men were employed in 1915. The mine is developed by a 200' crosscut tunnel, then 3800
Page 13 - Under the summit of the ridge a sudden drop occurred, necessitating another tunnel 50' lower; this was found to be the beginning of a fault zone which depressed the channel on the Nelson Creek side by several hundred feet. This fault zone lies approximately in the extension of the Spanish Peak fault, in the Bidwell Bar quadrangle, but they can not be connected with certainty. There is another fault zone in the region of La Porte. The block between these two zones, which includes the channel from...
Page 7 - In 1906 and 1907 the gravels of Poverty Hill were prospected with a view to drifting operations.
Page 33 - Four hundred feet further south a shaft was sunk into this channel and. rich quartz gravel 7' thick was found. About 3200' further south the South Fork Company crossed this channel and found the gravel practically all quartz, and carrying about 50^ per ton car in gold. It appears that the bulk of the gold contained in the 'Deep Lead,' and derived principally from the erosion of the higher channel, lies on the Bald Mountain ground. On this assumption it is estimated that this deep channel will pay...
Page 128 - ... •varies from 30° to 55° E. The rich ore taken from the lower workings has come from two areas, one just south of the winze connecting the upper and lower workings and the other about 700' north of the winze. At each place the vein is wider than the average, its width being about 7...

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