Early Bird Mine, Sugarloaf Mountain (3), West Shasta Copper - Zinc District, Klamath Mts, Shasta Co., California, USA

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A former Cu-Au-Ag mine located in sec. 11, T33N, R6W, MDM, 3.1 km (2.0 miles) N of Sugarloaf Mountain (coordinates of record), on private land (patented) in a National Forest. Discovered in 1900. The first year of production was 1922. The lessee/operator was Mason Valley Mines Co. (1977, 1926, 1928). The U.S. Smelting, Refining and Mining Co. had an unknown involvement here (1922, 1925). MRDS database stated accuracy for this location is 10 meters.

Mineralization is a sulphide deposit (Deposit model: 184: Massive sulfide, kuroko), hosted in porphyry and rhyolite. The ore body is a replacement deposit, tabular/blanket in form with a thickness of 9.14 meters, a width of 25.91 meters and a length of 140.21 meters (300 meters ?), and with a depth to top of 10 meters. It is hosted in light gray, siliceous rhyolite. The primary mode of origin was hydrothermal and the secondary mode was contact metasomatic. Primary ore control was folding with faulting as the secondary control. There is moderate wallrock alteration (intermediate argillic, sericitic, and pyritization). The ore is largely pyrite with chalcopyrite and sphalerite, which occur interstitial to the pyrite. Local rocks include Paleozoic metavolcanic rocks, unit 1 (Eastern Klamath Mountains).

Local structures include a fault which divides the ore body, South porphyritic rhyolite which is overlain by a flow of non-porphyritic rhyolite.

Workings include underground openings with a length of 246.89 meters.

Production statistics for 1925 (1922-1925): ^10.27 % Cu, 0.015 oz/ton Au, 0.41 oz/ton Ag. For 1928 (1925-1928): ^3.4% Cu, 0.034 oz/ton Au, 2.0 oz/ton Ag.

Ore from 4 drill holes averaged .03 oz/ton Au, 1.53 oz/ton Ag and 3.01% Cu.

Mineral List

Calcite Chalcopyrite

Muscovite var: Sericite Pyrite

Quartz Sphalerite

6 entries listed. 5 valid minerals.

References