Kwiniuk River

Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu; W
Other commodities REE
Ore minerals allanite; chalcopyrite; powellite; pyrite; scheelite
Gangue minerals apatite; epidote; garnet; hematite; hornblende; magnetite; rutile; sphene; spinel

Geographic location

Quadrangle map, 1:250,000-scale SO
Quadrangle map, 1:63,360-scale C-1
Latitude 64.729
Longitude -162.356
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at about 175 feet elevation on a north tributary to the Kwiniuk River. The mouth of this tributary is 1.6 miles downstream from the confluence of Kwiniuk River and a major south tributary that is unnamed on the curent USGS topographic map, but is identified as Corral Creek by West (1953, Plate 1). This is locality 134 of Cobb (1972, MF 445; 1978, OF 78-181).

Geologic setting

Geologic description

A heavy-mineral concentrate from stream gravels at this locality contained sphene, hornblende, allanite, apatite, hematite, garnet; traces of spinel, scheelite, powellite, magnetite, epidote, rutile, pyrite, and chalcopyrite. This sample (approximate concentration ratio of 230:1) contained 0.017% equivalent uranium (sample 2961, West, 1953). The stream drains the contact between the Darby pluton (Miller and others, 1972; Miller and Bunker, 1976; Johnson and others, 1979) and Paleozoic marble and related metasedimentary rocks (Till and others, 1986). The slightly uraniferous granodiorite and granite of the Darby pluton is mid-Cretaceous; K/Ar ages for the Darby pluton are 88.3 +/- 1.5 and 92.8 +/- 2.6 Ma (Berry and others, 1976). The possible sources of heavy minerals in the stream gravels include skarns, veins, and disseminations at or near the contact of the Darby pluton and metasedimentary rocks. The widespread elevated Nb values in stream sediments (Miller and Grybeck, 1973) and in heavy -mineral concentrates (West, 1953) of the Clear Creek-Vulcan Creek area to the north may indicate specific mineralized zones or disseminations in late, felsic phases of the Darby pluton (Miller and Grybeck, 1973).
Geologic map unit (-162.358583364864, 64.7282891674323)
Mineral deposit model Skarns, veins, or disseminations at or near the contact of the Darby pluton and metasedimentary rocks; disseminations in late, felsic phases of the Darby pluton.
Age of mineralization The lode source of the heavy minerals in the stream gravels is probably mid-Cretaceous, the age of the Darby pluton; K/Ar ages for the Darby pluton are 88.3 +/- 1.5 and 92.8 +/- 2.6 Ma (Berry and others, 1976).

Production and reserves

Workings or exploration There are no known workings; exploration in the region may have included reconnaissance stream sediment sampling and radiometric surveys.
Indication of production None

References

MRDS Number A012572; D002607

References

Reporters Travis L. Hudson (Applied Geology)
Last report date 8/19/1999