Unnamed (east end of Koiyaktot Mountain) (ARDF #HW018) Ag, Pb, Zn

Unnamed (east end of Koiyaktot Mountain)

Occurrence, Inactive

Commodities and mineralogy

Main commodities	Ag; Pb; Zn
Other commodities	Cu; Sb
Ore minerals	galena; sphalerite
Gangue minerals	quartz

Geographic location

Quadrangle map, 1:250,000-scale	HW
Quadrangle map, 1:63,360-scale	A-1
Latitude	68.1891
Longitude	-156.1382
Nearby scientific data	Find additional scientific data near this location
Location and accuracy	This occurrence is at the east end of Koiyaktot Mountain about 0.9 mile southeast of peak 1302 (in meters). It is near the center of section 9, T. 32 N., R. 12 E.

Geologic setting

Geologic description The rocks in the area are northwest-trending, southwest-dipping Upper Devonian to Lower Mississippian Kanayut Conglomerate and Noatak Sandstone that are repeated by thrust faults. Quartz veins and breccia with sphalerite and galena occur in siltstone of the Noatak Sandstone (Kurtak and others, 1995). The mineralization occurs in float and rubblecrop of unknown extent along a north-trending zone. Samples contained up to 39.9 percent lead, 23.9 percent zinc, 1,404 parts per million (ppm) cadmium, and 1,838 grams of silver per tonne. A breccia sample contained 1,3756 ppm copper and one sample of sphalerite and galena contained more than 2,000 ppm antimony.
Geologic map unit	(-156.1410867155, 68.1885984031175)
Mineral deposit model	Remobilized, lead-zinc sandstone deposit?
Age of mineralization	Possibly Mississippian by analogy with other lead-zinc deposits in the western Brooks Range.
Alteration of deposit	Not noted.

Production and reserves

Workings or exploration	Only sampling and mapping by the U.S. Bureau of Mines.
Indication of production	None
Reserve estimates	None.
Production notes	None.
Additional comments MAS number 0020200014.

References

MRDS Number	A106126
References Jansons, Uldis, and Parke, M.A., 1981, 1978 mineral investigations in the Misheguk Mountain and Howard Pass quadrangles: U.S. Bureau of Mines Open-File Report 26-81, 195 p., 1 sheet. Kurtak, J.M., Meyer, M.P., Hicks, R.W., Werdon, M.B., and Mull, C.G., 1995, Mineral investigations in the Colville Mining District and southern National Petroleum Reserve in Alaska: U.S. Bureau of Mines Open-File Report 8-95, 217 p., 1 sheet, scale 1:250,000. Meyer, M.P., and Kurtak, J.M., 1992, Results of the 1991 U.S. Bureau of Mines Colville mining district study: U.S. Bureau of Mines Open-File Report 75-92, 101 p.
Reporters	J.M. Schmidt (U.S. Geological Survey); D.J. Grybeck (Contractor, U.S. Geological Survey)
Last report date	4/18/2010