Unnamed (west of upper Yankee Creek)

Prospect, Probably inactive

Commodities and mineralogy

Main commodities Au
Other commodities Ag; As; Sb
Ore minerals arsenopyrite; gold; iron oxides; stibnite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale ID
Quadrangle map, 1:63,360-scale D-1
Latitude 62.95607
Longitude -156.439
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is at an elevation of about 1,900 feet above a low saddle on an east-west-trending ridge near the head of Yankee Creek. The prospect is about 600 feet west of the Telephone Hill prospect (ID035) near the center of the N1/2 NW1/4, section 14, T. 33 N., R. 38 W., of the Seward Meridian. The location is accurate.

Geologic setting

Geologic description

This deposit at this prospect is a thin gold-quartz-sulfide vein that cuts a quartz-feldspar porphyry dike near its contact with sandstone of the Upper Cretaceous, Kuskokwim group (Miller and Bundtzen, 1994). The dike, as partly exposed in rubble crop, is about 25 feet thick and strikes about N70E. The vein, which is probably subparallel to the dike, is about 16 inches thick The vein contains about 2 percent, fine-grained arsenopyrite and less abundant, bladed stibnite crystals. Free gold occurs in pockets of iron oxide oxidized from the sulfides. One sample of sulfide-bearing quartz vein contained 7.02 parts per million gold (Bundtzen and Laird, 1983; McGimsey and others, 1988). The quartz-feldspar porphyry dike is part of the dike-sill complex associated with the Ganes-Yankee Creek fault zone (Bundtzen and Laird, 1983; Bundtzen and Miller, 1997).
Geologic map unit (-156.441363406348, 62.9554370924908)
Mineral deposit model Low sulfide gold-quartz vein or Porphyry gold-copper deposit; (Cox and Singer, 1986; models 36a and 20c); possibly the porphyry gold type deposit of Hollister (1992); or the peraluminous granite, porphyry gold-polymetallic type deposit of Bundtzen and Miller (1997).
Mineral deposit model number 36a or 20c
Age of mineralization Biotite from a dike at the Telephone Hill prospect (ID035) nearby has a 40Ar/39Ar age of 70.6 Ma (Bundtzen and others, 2000).
Alteration of deposit The quartz-feldspar dike is moderately sericitized.

Production and reserves

Workings or exploration Prior to World War II, the prospect was explored by two elongate pits about 50 feet apart. West Gold Inc. explored the area and collected soil samples in the prospect area in 1989; Placer Dome Exploration collected soils in the area in 1997. North Star Exploration, Inc. conducted exploration and sampled rocks and soils in 1998 and 2001.
Indication of production None

References

References

Bundtzen, T.K., and Miller, M.L., 1997, Precious metals associated with Late Cretaceous-early Tertiary igneous rocks of southwestern Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral Deposits of Alaska: Economic Geology Monograph 9, p. 242-286.
Bundtzen, T.K., Bouley, B.A., Noyes, H.J., and Nokleberg, W.J., 2000, Regional metallogenesis of central Alaska: Society of Mining, Metallurgy, and Exploration Annual Meeting, Salt Lake City, Utah, February 28-March 1, 2000, p.1-29.
Hollister, V.F., 1992, On a proposed plutonic porphyry gold deposit model: Nonrenewable Resources, vol. 1, p. 293-302.
Reporters T.K. Bundtzen (Pacific Rim Geological Consulting, Inc.), M.L. Miller (U.S. Geological Survey); and C.C. Hawley (Hawley Resource Group)
Last report date 5/16/2003