Unnamed (west end of Koiyaktot Mountain)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Ag; Pb; Zn
Other commodities Au; Cu
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 68.2169
Longitude -156.2926
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is plotted near the center of a north-trending area about 0.7 mile long in the west portion of Koiyaktot Mountain; it is about 4.4 mile northeast of Inyorurak Pass near the center of section 34, T. 33 N., R. 11 E.

Geologic setting

Geologic description

The rocks in the area consist of northwest-trending, southwest-dipping Upper Devonian to Lower Mississippian, Kanayut Conglomerate and Noatak Sandstone that are repeated by thrust faults. Four small, separate zones of mineralization occur along a north-trending zone about 0.7 mile long (Kurtak and others, 1995). The mineralization is in sandstone and consists of quartz-cemented breccia with sphalerite and galena. Samples from one area about 15 meters by 90 meters in size contained 43.9 percent zinc, 3.27 percent lead, and 404 parts per million (ppm) copper. About 950 meters to the north, samples from another area about 15 meters by 152 meters in size contained up to 16.2 percent zinc, 64.4 grams of silver per tonne, and 336 parts per billion gold.
Geologic map unit (-156.295494461325, 68.2163965977164)
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 0020200015.