Unnamed (southeast of summit of Granite Mountain) (ARDF #ID149) As, Bi, Zn

Unnamed (southeast of summit of Granite Mountain)

Occurrence, Inactive

Commodities and mineralogy

Main commodities	As; Bi; Zn
Other commodities	Fe; Hg; Sb
Ore minerals	hematite; limonite

Geographic location

Quadrangle map, 1:250,000-scale	ID
Quadrangle map, 1:63,360-scale	B-2
Latitude	62.31123
Longitude	-156.70347
Nearby scientific data	Find additional scientific data near this location
Location and accuracy	This occurrence is on the southeast slope of Granite Mountain at an elevation of about 1,600 feet. It is about 0.9 mile south-southeast of peak 2923, the top of Granite Mountain, and about 0.2 mile south of the center of section 28, T. 26 N., R. 40 W., of the Seward Meridian. The location is accurate.

Geologic setting

Geologic description This occurrence consists of a hematite-bearing, breccia zone of unknown size and orientation in shale and sandstone of the Upper Cretaceous Kuskokwim Group. It is about a mile southeast of the edge of the Granite Mountain pluton (Miller and Bundtzen, 1994; Bundtzen and Miller, 1997, and Bundtzen, Miller, and Gray, 2004). A grab sample of mineralization contained 450 parts per million (ppm) zinc, more than 10 ppm mercury, 400 ppm arsenic, 7.0 ppm bismuth, 22 ppm antimony, and 15.00 percent iron (McGimsey and others, 1988).
Geologic map unit	(-156.70584841223, 62.310564003679)
Mineral deposit model	Polymetallic vein (Cox and Singer, 1986; model 22c).
Mineral deposit model number	22c
Age of mineralization	Unknown; the nearby Granite Mountain pluton has a 40K/40Ar age of 62.6 Ma Bundtzen and Miller, 1997).
Alteration of deposit	Hematite.

Production and reserves

Workings or exploration	Samples were collected by the U.S. Geological Survey and Alaska Division of Geological and Geophysical Surveys in 1986 (McGimsey and others, 1988).
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. McGimsey, R.G., Miller, M.L., and Arbogast, B.F., 1988, Paper version of analytical results, and sample locality map for rock samples from the Iditarod quadrangle, Alaska: U.S. Geological Survey Open-File Report 88-421-A, 110 p., 1 sheet, scale 1:250,000. Miller, M.L., and Bundtzen, T.K., 1994, Generalized geologic map of the Iditarod quadrangle, Alaska showing potassium-argon, major oxide, trace element, fossil, paleocurrent, and archeological sample localities: U.S. Geological Survey Miscellaneous Field Studies Map MF-2219-A, 48 pages; 1 sheet, scale 1:250,000. Miller, M.L., Bundtzen, T.K., and Gray, J.E., 2005, Mineral resource assessment of the Iditarod quadrangle, west-central Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-2219-B, scale 1:250,000, pamphlet.
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	5/25/2003