Seattle Alaska Copper Co. Mine, Prince William Sound Mining District, Valdez-Cordova Census Area, Alaska, USAi

Regional Level Types
Seattle Alaska Copper Co. Mine	Mine
Prince William Sound Mining District	Mining District
Valdez-Cordova Census Area	Census Area
Alaska	State
USA	Country

Location: The occurrence consists of three tunnels that are located just below VABM Fairview 1926; it is in the NE1/4 of section 36, T. 2 S., R. 8 E., of the Seward Meridian. The lower tunnel is at an elevation of 1,150 feet . The middle tunnel is at an elevation of 1,350 feet and the upper tunnel is at an elevation of 1,450 feet. There is an open cut on the discovery outcrop just above the upper tunnel . This is location number 8 of Cobb (1972, MF-440) and location 270 of Tysdal (1978). This location is accurate to within a quarter of a mile.
Geology: The country rock in the vicinity of the prospect is graywacke and shale of the Tertiary Orca Group (Nelson and others, 1980). The strike of the bedding is northeast and dips 70W. The mineralization consists of siliceous massive sulfides and stringers of sulfides containing predominantly pyrite, pyrrhotite, and chalcopyrite. The mineralization varies from 18 to 66 inches in width and strikes N35 to 50E and dips 70 to 80W. Locally the mineralization is parallel to the schistosity of the country rock. Samples by the Bureau of Mines (Kurtak and Jeske, 1986) assayed up to 6.5% copper and 14 ppm silver.
Workings: There were 840 feet of underground workings driven between 1908 and 1911. In 1911 a mill was set up and run for a short while. In 1914 a test shipment of 12 tons of ore that ran 0.97% copper and 1.92 ounces of silver per ton resulted in the production of 2,350 pounds of copper and 23 ounces of silver (Johnson, 1918 p. 209-210). The prospect has tunnels at three levels and one open cut. The lower two tunnels are the most extensively developed. The lower tunnel is collapsed and reported to consists of 400 feet of workings . The middle tunnel was open in 1985 and is about 400 feet long; two drifts, 20 feet and 50 feet in length, were driven along the mineralized zone. The Bureau of Mines (Kurtak and Jeske, 1986) sampled the middle tunnel across a four foot width that contained 6.5% copper and 14 ppm silver. The 40-foot-long upper tunnel is collapsed. Martin and others (1915) reported that this tunnel was weakly mineralized. In 1976, Noranda Exploration staked the area and conducted geophysical studies.
Age: Tertiary; massive sulfides in Tertiary rocks.
Alteration: None reported.
Production: In 1914 a test shipment of 12 tons of ore that ran 0.97% copper and 1.92 ounces of silver per ton resulted in the production of 2,350 pounds of copper and 23 ounces of silver (Johnson, 1918 p. 209-210).
Reserves: Kurtak and Jeske (1986) inferred a reserve of 2,900 tons copper in ore that contains 3% copper and 8.7ppm silver.

Commodities (Major) - Cu, Zn; (Minor) - Ag
Development Status: None
Deposit Model: Cyprus massive sulfide (Cox and Singer, 1986; model 24a).

Other Databases

Link to USGS - Alaska:	BS013

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References