|Quadrangle map, 1:250,000-scale||SO|
|Quadrangle map, 1:63,360-scale||C-5|
|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).|
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.|
|Workings or exploration||The mineralization is exposed in outcrop. A prospect trench exposes some mineralization upslope to the north.|
|Indication of production||None|
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.
Asher, R.R., 1969, Geological and geochemical study, Solomon C-5 Quadrangle, Seward Peninsula, Alaska: Alaska Division of Mines and Geology Geologic Report 33, 65 p., 2 sheets.
Cobb, E.H., 1972, Metallic mineral resources map of the Solomon quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-445, 1 sheet, scale 1:250,000.
Cobb, E.H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Solomon quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-181, 185 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.
Miller, E.L., and Hudson, T.L., 1991, Mid-Cretaceous extensional fragmentation of a Jurassic-Early Cretaceous compressional orogen, Alaska: Tectonics, v. 10, p. 781-796.
Sainsbury, C.L., Hudson, T.L., Ewing, R., and Marsh, W.R., 1972, Reconnaissance geologic maps of the Solomon D-5 and C-5 quadrangles, Seward Peninsula, Alaska: U.S. Geological Survey Open-File Report 72-324, 12 p., 2 sheets, scale 1:63,360.
|Reporters||Travis L. Hudson (Applied Geology)|
|Last report date||8/19/1999|