Unnamed (north of Big Hurrah Creek)

Prospect, Probably inactive

Commodities and mineralogy

Main commodities Au; Sb
Ore minerals gold; stibnite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale SO
Quadrangle map, 1:63,360-scale C-5
Latitude 64.654
Longitude -164.278
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is on the north side of Big Hurrah Creek (SO022) about one mile upstream from its mouth. It is locality 3 of Asher (1969, DGGS R33).

Geologic setting

Geologic description

A 10-foot-wide silicified and brecciated zone in very fine-grained graphitic schist contains disseminated sulfides, mostly pyrite. However, along the footwall side, stibnite is disseminated and forms blades to 3 inches long (Asher, 1969, DGGS R33). The zone strikes N 12 E and dips 44 W. A prospect trench upslope to the north has dump material with abundant stibnite. A sample across the 10-foot-wide silicified zone contained 0.07 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 veins may be similar in age to some lode gold deposits on southern Seward Peninsula. The 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 (-164.280605633239, 64.6532577921754)
Mineral deposit model Gold-quartz vein; low sulfide-Au quartz vein (Cox and Singer, 1986; model 36a) or quartz-stibnite vein in graphitic schist; simple Sb deposits (Cox and Singer, 1986; model 27d).
Mineral deposit model number 27d or 36a
Age of mineralization Mid-Cretaceous?
Alteration of deposit Silicification.

Production and reserves

Workings or exploration The mineralization is exposed in outcrop. A prospect trench exposes some mineralization upslope to the north.
Indication of production None

References

MRDS Number 10308321

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