Fish; Collins and Stewart Prospect, Prince William Sound Mining District, Valdez-Cordova Census Area, Alaska, USAi

Regional Level Types
Fish; Collins and Stewart Prospect	Prospect
Prince William Sound Mining District	Mining District
Valdez-Cordova Census Area	Census Area
Alaska	State
USA	Country

Location: The prospect is located at an elevation of 800 feet, above the west shore of Esther Lake in the southwest portion of Esther Island. (It is reported to be one mile from shore.) The prospect is in the W1/2 section 31, T. 9 N., R. 8 E., of the Seward Meridian. This is location 89 of Condon and Cass (1958), location 85 of Cobb and Richter (1972), location 105 of MacKevett and Holloway (1977), location 168 of Cobb and Tysdal (1980), and location S-125 of Jansons and others (1984). This location is accurate to within half a mile.
Geology: The prospect consists of a 40-foot adit in contact-metamorphosed slate and sandstone of the Valdez Group of Late Cretaceous age near the margin of the Esther pluton of Tertiary age (Cobb and Tysdal, 1980). The adit was driven on a 4- to 5-foot-wide shear that strikes N14E and dips 85W. The margin of the shear zone is well defined with abundant clay gouge. Quartz veins in the shear zone range in size from less than 4 inches to more than 2 feet in width and consists of bluish-white quartz containing chalcopyrite, pyrrhotite, and gold (Johnson, 1914 [B 592-G, p. 234-235]). Fieldwork by the U.S. Bureau of Mines in 1979 failed to locate the adit. Their sample of a vertical, N25E, 40-inch-wide, pyrite-bearing quartz vein in the vicinity did not contain any significant metals values (Hoekzema and Sherman, 1983).
Workings: A 40-foot adit was driven in 1912 (Johnson, 1914 [B 592-G, p. 234-235]). The U.S. Bureau of Mines searched for the prospect in 1979, but did not locate any workings. In the vicinity, they found and sampled a 40-inch-wide pyrite-bearing quartz vein striking N25E and dipping vertically. The vein assayed at 0.04 ppm gold, 0.2 ppm silver, 75 ppm copper, 5 ppm lead, 50 ppm zinc, and 30 ppm arsenic (Hoekzema and Sherman, 1983).
Age: Tertiary or younger; the deposit in is a shear zone that cuts Tertiary granite.
Alteration: Contact metamorphism.

Commodities (Major) - Au; (Minor) - Cu
Development Status: None
Deposit Model: Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)

Other Databases

Link to USGS - Alaska:	SR087

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References