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.