Unnamed Occurrence (ARDF - SI015; north end of Yakobi Island), Chichagof District, Skagway-Hoonah-Angoon Borough, Alaska, USA

• Display
  • Standard
  • Detailed
  • By Strunz Category
  • By Dana Category
• Photos
  • Add Photo
• Maps
  • Map Pages
  • Nearest Localities
• Search
  • Mineral Search
  • Search Google
  • Link to USGS - Alaska

Location: This occurrence is at an elevation of about 500 feet on northwest Chichagof Island, about 1.7 miles south-southeast of Junction Island. The occurrence is in the SW1/4SE1/4 sec. 11, T. 45 S., R. 56 E. It is location 4 of Cobb (1972, 1978). The location is accurate within about 0.5 mile.
Geology: Johnson and Karl (1985) map the rocks in the area of this prospect as a stock of Cretaceous or Jurassic diorite. The stock is cut by diverse faults, the most prominent of which is the Peril Strait Fault, a regional-scale, northwest-striking, high-angle fault that truncates the stock on the northeast. Cobb (1972, 1978), citing Rossman (1959), reports that this prospect is a mineralized fault zone between diorite and quartz diorite. A sample contained a trace of gold. 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).
Age: 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).

Commodities (Major) - Au
Development Status: Undetermined.
Deposit Model: Low-sulfide gold-quartz vein (Cox and Singer, 1986; model 36a).

References

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. Johnson, B.R, and Karl, S.M., 1985, Geologic map of western Chichagof and Yakobi Islands, southeastern Alaska: U.S. Geological Survey Miscellaneous Investigations Series Map 1-1506, 1 sheet, scale 1:125,000. 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.

Mineral List

Quartz

1 entry listed. 1 valid mineral.