Unnamed (upper Niukluk River)

Prospect, Inactive

Commodities and mineralogy

Main commodities Cu; Pb
Ore minerals azurite; cerussite; chalcopyrite; chrysocolla; duftite; galena
Gangue minerals limonite; pyrite; quartz

Geographic location

Quadrangle map, 1:250,000-scale BN
Quadrangle map, 1:63,360-scale A-4
Latitude 65.2
Longitude -163.875
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is on the same ridge as BN130 but about 1,500 feet downslope to the west at an elevation of about 1,750 feet.

Geologic setting

Geologic description

Complex intergrowths of limonite (replacing pyrite and chalcopyrite) and drusy comb-quartz are present in a tabular body of silicified breccia 2 feet-wide. Abundant secondary minerals include malachite, chrysocolla, azurite, cerussite, and duftite(?). This is at the silicified contact between marble and amphibolite schist and there is minor silicified gouge in the breccia. This locality, and several others in this part of the Bendeleben A-4 quadrangle, are in high grade metamorphic rocks that are structurally above or peripheral to the crosscutting Pargon pluton. The Pargon pluton is mostly granodiorite and assumed to be Cretaceous in age (Till and others, 1986). It was emplaced at shallower depths than the more deep-seated Bendeleben pluton to the east. The metamorphic rocks peripheral to the western Pargon pluton are also intruded by small, felsic dikes and plugs including quartz porphyry and muscovite granite.
Geologic map unit (-163.877643401645, 65.1992752565229)
Mineral deposit model Polymetallic vein (and breccia) in high grade metamorphic rocks (Cox and Singer, 1986; model 22c?).
Mineral deposit model number 22c?
Age of mineralization Cretaceous ?; this occurrence may be related to emplacement of the Pargon pluton which is assumed to be Cretaceous in age.
Alteration of deposit Silicification; extensive oxidation and secondary mineral development; faulting and gouge development.

Production and reserves

Workings or exploration Shallow prospect pits and short caved adit are present in the area.
Indication of production None

References

MRDS Number A012767; A012770

References

Reporters Travis L. Hudson (Applied Geology)
Last report date 3/15/1999