|Quadrangle map, 1:250,000-scale||SI|
|Quadrangle map, 1:63,360-scale||C-7|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The Hodson prospect is at an elevation of about 1,000 feet on the north flank of Doolth Mountain, about midway between the claim boundaries of the Hirst-Chichagof (SI087) and Chichagof (SI093) mines. The prospect is 0.1 mile east-southeast of the center of sec. 25, T. 48 S., R. 57 E. It is location P-61 of Bittenbender and others (1999) and MAS no. 0021140310 (U.S. Bureau of Land Management, 2002). The location is accurate.|
Johnson and Karl (1985) map the rocks in the area of this prospect as Cretaceous graywacke and argillite interbedded with sparse, lenticular beds of basalt. The rocks are cut by numerous high-angle, mainly northwest-striking faults. They include extensions of the faults at the Hirst (SI087) and Chichagof (SI093) mines, which control the mineralization there and straddle this prospect.
Reed and Coats (1941) describe this prospect as an auriferous quartz vein up to 2 feet thick along a fault that strikes N50W and dips 75SW. Exploration in the late 1930s included several prospect pits over a horizontal distance of about 200 feet, and diamond drilling, the results of which were not made public.
Bittenbender and others (1999), citing Smith (1926), describe the prospect as thin, auriferous quartz veins in graywacke. Samples of the veins contained up to 0.33 ounce of gold per ton. The prospect was explored by a 235-foot adit. There is no record of production, but some gold may have been produced.Isotopic studies indicate that the gold-quartz veins in coastal southern and southeastern Alaska are Eocene, about 50 Ma in age (Haeussler, 1995; Goldfarb, 1997; Goldfarb and others, 1997). ARDF record SI087 provides an overview of the geology of auriferous quartz veins in the Chichagof Mining District.
|Geologic map unit||(-136.104726081136, 57.678127724511)|
|Mineral deposit model||Low-sulfide gold-quartz vein (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).|
|Workings or exploration||Reed and Coats (1941) report that exploration in the late 1930s included several prospect pits over a horizontal distance of about 200 feet, and diamond drilling, the results of which were not made public. Bittenbender and others (1999) report a 235-foot adit.|
|Indication of production||Undetermined|
|Production notes||There is no record of production, but the extent of the workings suggests that some gold may have been produced.|
Additional commentsThe prospect is in West Chichagof-Yakobi Wilderness.
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.
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.
Goldfarb, R.J., Miller, L.D., Leach, D.L., and Snee, L.W, 1997, Gold deposits in metamorphic rocks in Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral Deposits of Alaska: Economic Geology Monograph 9, p. 151-190.
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.
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.
Smith, P.S., 1926, Mineral industry of Alaska in 1924: U.S. Geological Survey Bulletin 783-A, p. 1-30.
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|