Unnamed (near Big Hurrah Creek)

Prospect, Inactive

Commodities and mineralogy

Main commodities Au
Ore minerals arsenopyrite; gold; marcasite; pyrite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale SO
Quadrangle map, 1:63,360-scale C-5
Latitude 64.652
Longitude -164.261
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is on the south side of Big Hurrah Creek (SO022) about 0.2 miles upstream of the mouth of Linda Vista Creek, a south tributary. This is locality 2 of Asher (1969, DGGS R33).

Geologic setting

Geologic description

Two short adits explore quartz veins at this locality. The lower adit is reported to have exposed a 7- to 8-foot-wide, vertical but faulted, quartz vein (Smith, 1910, p. 147). The upper adit, a few hundred feet to the south of the lower one, is on a 1-foot-wide quartz vein with arsenopyrite, pyrite, and possibly marcasite (Asher, 1969, DGGS R33). A grab sample of this vein assayed 0.003 ounces Au per ton (Asher, 1969, DGGS R33). The country rock is part of a lower Paleozoic metasedimentary assemblage that includes a distinctive black, very fine-grained, graphitic schist (Sainsbury and others, 1972, OFR 511; Till and others, 1986).
These quartz veins may be similar in age to some other gold-quartz veins of southern Seward Peninsula. The other southern Seward Peninsula lode gold deposits formed as a result of mid-Cretaceous metamorphism (Apodoca, 1994; Ford, 1993, Ford and Snee, 1996; Goldfarb and others, 1997) that accompanied regional extension (Miller and Hudson, 1991) and crustal melting (Hudson, 1994). This higher temperature metamorphism was superimposed on high pressure/low temperature metamorphic rocks of the region.
Geologic map unit (-164.263605751659, 64.6512581735835)
Mineral deposit model Gold-quartz vein in metamorphic rocks; low sulfide-Au quartz vein (Cox and Singer, 1986; model 36a).
Mineral deposit model number 36a
Age of mineralization Mid-Cretaceous?; possibly same age as some other gold-quartz veins of southern Seward Peninsula.
Alteration of deposit Quartz veining in metamorphic rocks.

Production and reserves

Workings or exploration Two short adits explored quartz veins at this site.
Indication of production None

References

MRDS Number A012594

References

Apodoca, L.E., 1994, Genesis of lode gold deposits of the Rock Creek area, Nome mining district, Seward Peninsula, Alaska: Boulder, Colorado, University of Colorado, Ph.D. dissertation, 208 p.
Ford, R.C., 1993, Geology, geochemistry, and age of gold lodes at Bluff and Mt. Distin, Seward Peninsula, Alaska: Golden, Colorado School of Mines, Ph.D. dissertation, 302 p.
Ford, R.C., and Snee, L.W., 1996, 40Ar/39Ar thermochronology of white mica from the Nome district, Alaska--The first ages of lode sources to placer gold deposits in the Seward Peninsula: Economic Geology, v. 91, p. 213-220.
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.
Hudson, T.L., 1994, Crustal melting events in Alaska, in Plafker, G., and Berg, H. C., eds., The Geology of Alaska: Geological Society of America, DNAG, The Geology of North America, Vol. G-1, p. 657-670.
Reporters Travis L. Hudson (Applied Geology)
Last report date 8/19/1999