|Quadrangle map, 1:250,000-scale||SI|
|Quadrangle map, 1:63,360-scale||D-8|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The Goldwin Mine is on northwestern Chichagof Island, near the tip of the point at the junction of Lisianski Strait and Lisianski Inlet. The mine is at an elevation of about 350 feet, about 0.6 mile southeast of the center of sec. 4, T. 45 S., R. 56 E. It is location P-13 of Bittenbender and others (1999), location 3 of Cobb (1972, 1978), and MAS. no. 0021140039 (U.S. Bureau of Land Management, 2002). The location is accurate.|
The Goldwin deposit consists of auriferous, sulfide-bearing quartz veins along faults in Cretaceous or Jurassic diorite (Rossman, 1959; Johnson and Karl, 1985; Bittenbender and others, 1999). The veins pinch and swell, range in thickness from less than an inch to about 2.5 feet, and have been traced in surface and underground workings for about 400 feet. The quartz contains sparse pyrite and chalcopyrite, mainly near altered diorite inclusions in the veins. The gold is free-milling and mainly accompanies the sulfides; the altered wallrock also carries a little gold.
The deposit was located in 1920 and probably was mined intermittently until WW II. Workings included pits, trenches, and an adit about 250 feet long. An unknown, but probably small, amount of gold and silver were recovered. Picked samples reportedly assayed about 1.7 ounces of gold per ton (Reed and Coats, 1941) and 2.9 ounces of gold per ton (Buddington, 1925); Rossman (1959) reported an assay of 69 ounces of gold per ton over a half-foot section of pyrite-rich vein. Kimball (1982) collected representative samples that assayed up to 0.11 ounce of gold per ton.Isotopic studies indicate that the gold-quartz veins in coastal southern and southeastern Alaska are Eocene, about 50 Ma in age (Haeussler and others, 1995; Goldfarb, 1997; Goldfarb and others, 1997).
|Geologic map unit||(-136.33773596361, 57.993216708572)|
|Mineral deposit model||Low sulfide, gold-quartz veins (Cox and Singer, 1986, model 36a).|
|Mineral deposit model number||36a|
|Age of mineralization||Isotopic studies indicate that the gold-quartz veins in coastal southern and southeastern Alaska are Eocene, about 50 Ma in age (Haeussler and others, 1995; Goldfarb, 1997; Goldfarb and others, 1997).|
|Alteration of deposit||Unspecified hydrothermal(?) alteration of diorite wallrock in and adjacent to the veins.|
|Workings or exploration||The deposit was located in 1920 and probably was mined intermittently until WW II. Workings included pits, trenches, and an adit about 250 feet long.|
|Indication of production||Yes; small|
|Production notes||The deposit was intermittently mined from 1920 to 1941 but there are no records of the amount of production.|
Bittenbender, P., Still, J.C., Maas, K., and McDonald, M., Jr., 1999, Mineral resources of the Chichagof and Baranof Islands area, southeast Alaska: Bureau of Land Management, BLM-Alaska Technical Report 19, 222 p.
Buddington, A.F., 1925, Mineral investigations in southeastern Alaska: U.S. Geological Survey Bulletin 773-B, p. 71-139.
Cobb, E.H., 1972, Metallic mineral resources map of the Sitka quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-467, scale 1:250,000.
Cobb, E.H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Sitka quadrangle: U.S. Geological Survey Open-File Report 78-450, 124 p.
Goldfarb, R J., 1997, Metallogenic evolution of Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral Deposits of Alaska: Economic Geology Monograph 9, p. 4-34.
Haeussler, P J., Bradley, D., Goldfarb, R., Snee, L., and Taylor, C., 1995, Link between ridge subduction and gold mineralization in southern Alaska: Geology, v. 23, no. 11, p. 995-998.
Kimball, A.L., 1982, Mineral land assessment of Yakobi Island and adjacent parts of Chichagof Island, southeastern Alaska: U. S. Bureau of Mines Mineral Land Assessment report, MLA 97-82, 199 p.
Reed, J.C., and Coats, R.R., 1941, Geology and ore deposits of the Chichagof mining district, Alaska: U.S. Geological Survey Bulletin 929, 148 p.
Roehm, J.C., 1936, Preliminary report of Goldwin Group, Lisianski Inlet, Chichagof Island, Sitka Mining District: Alaska Territorial Department of Mines, Property Examination 114-2, 2 p.
Rossman, Darwin, 1959, Geology and ore deposits of the northwestern part of Chichagof Island, Alaska: U.S. Geological Survey Bulletin 1058-E, p. 139-216.
U.S. Bureau of Land Management, 2002, Alaska mineral locations database report (Sitka quadrangle), July 2, 2002, 205 p. [http://imcg.wr.usgs.gov/dem.html]
|Reporters||H.C. Berg (U.S. Geological Survey)|
|Last report date||10/16/2004|