|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 American Gold Company's prospect is at an elevation of about 500 feet on the south ridge of Doolth Mountain, about 1.6 mile from the peak. The prospect is 0.2 mile west of the center of sec. 4, T. 49 S., R. 58 E. It is location P-69 of Bittenbender and others (1999), location 31 of Cobb (1972, 1978), and MAS no. 0021140006 (U.S. Bureau of Land Management, 2002). The location is accurate within 0.2 mile.|
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.
Reed and Coats (1941) describe this prospect as quartz veins along faults in slaty graywacke; the graywacke is intruded by a 5-foot-thick, partly silicified and sericitized dike. The graywacke strikes N35-55W and dips about 72SW. The faults strike N40-50W, dip 70-77SW, and offset the dike. Mineralization consists of gold-bearing quartz in the faults, and gold-bearing quartz veinlets that fill joints in the graywacke. Workings along two of the faults include an open cut and a tunnel with about 75 feet of crosscuts and 110 feet of drifts on two faults.
Bittenbender and others (1999), citing Still and Weir (1981), report that samples of narrow quartz veins contained up to 0.18 ounce of gold per ton, and a selected sample contained 2.42 ounces of gold per ton. Workings include a 220-foot adit with a winze, and a pit. There is no record of production, but the assay data and the extent of the workings suggest that 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||(-136.11902420353, 57.6492281646844)|
|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).|
|Alteration of deposit||Dike is partly silicified and sericitized.|
|Workings or exploration||Reed and Coats (1941) report an open cut and a tunnel with about 75 feet of crosscuts and 110 feet of drifts on two faults. Bittenbender and others (1999) report a 220-foot adit with a winze, and a pit.|
|Indication of production||Undetermined|
|Production notes||There is no record of production, but the assay data and the extent of the workings suggest 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.
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.
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.
Still, J.C., and Weir, K.R., 1981, Mineral land assessment of the west portion of western Chichagof Island, Southeast Alaska: U.S. Bureau of Mines Open-File Report 89-81, 269 p., 12 sheets.
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|