Unnamed (east of VABM Allen)

Prospect, Inactive

Commodities and mineralogy

Main commodities Cu
Other commodities Mo
Ore minerals azurite; bornite; chalcocite; chalcopyrite; covellite; malachite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale WI
Quadrangle map, 1:63,360-scale C-5
Latitude 67.5469
Longitude -152.0431
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is in a high saddle about 0.8 mile east-northeast of VABM Allen and about 4 miles northeast of the junction of Sheep Creek and John River. The prospect is at an elevation of about 4,000 feet near the southeast corner of section 32, T. 32 N., R. 20 W.. The location is accurate.

Geologic setting

Geologic description

Brosge and Reiser (1960) described copper sulfides and malachite at this prospect in fault contact between Devonian Skajit Limestone and a Devonian phyllite and siltstone unit. Dillon and others (1981, sample 284) described disseminated covellite and bornite and malachite stain in pale-green calc-schist and quartz veins. A sample contained up to 5,000 parts per million (ppm) copper and 10 ppm molybdenum. Kurtak and others (2002) analyzed one rock sample of chlorite-quartz schist that contained chalcocite, malachite and azurite. It contained 1,664 ppm copper, 4.8 ppm silver, and 23 parts per billion (ppb) gold. Degenhart and others (1978) reported minor amounts of chalcopyrite, bornite and malachite in metamorphosed, reef limestone near VABM Allen, only a short distance west of this location. Prior to the mid-1970s, at least five companies including Bear Creek Mining Company, General Crude Oil Company, New Jersey Zinc Company, Alvenco Inc., and BP Alaska prospected and sampled in the area as part of their work in a 5-mile-long, northeast-trending belt of mineral occurrences along a thrust fault (Degenhart, and others, 1978).
Geologic map unit (-152.045857247198, 67.5464430549741)
Mineral deposit model Unclear from the limited information.
Age of mineralization Devonian or younger based on the age of the host rocks.
Alteration of deposit Local oxidation of copper minerals.

Production and reserves

Workings or exploration Prior to the mid-1970s, at least five companies including Bear Creek Mining Company, General Crude Oil Company, New Jersey Zinc Company, Alvenco Inc., and BP Alaska prospected and sampled in the area as part of their work in a 5-mile-long, northeast-trending belt of mineral occurrences along a thrust fault (Degenhart and others, 1978). Examined and sampled by the U.S. Geological Survey (Brosge and Reiser, 1960), the Alaska Division of Geological and Geophysical Survey (Dillon and others, 1981), and the Bureau of Land Management (Kurtak and others, 2002).
Indication of production None
Reserve estimates None.
Production notes None.

Additional comments

See also WI016 and WI006.

References

MRDS Number A011951; A011985

References

Reporters J.M. Britton (Anchorage); D.J. Grybeck (Contractor, USGS)
Last report date 2/1/2011