Unnamed (ridge east of Scofield Creek)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Ag; Pb; Zn
Other commodities As; Ba; Fe; La
Ore minerals sphalerite

Geographic location

Quadrangle map, 1:250,000-scale WI
Quadrangle map, 1:63,360-scale B-3
Latitude 67.3278
Longitude -151.3112
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is between Scofield and Michigan Creeks, about 7.5 miles west of Ipnek Mountain and 2.8 miles northeast of the junction of Scofield Creek and Wild River. The occurrence is at an elevation of about 3,550 feet, about 0.5 mile north-northeast of the center of section 22, T. 29 N., R. 17 W. The location is accurate.

Geologic setting

Geologic description

This occurrence is a gossan zone at the contact of calc-schist and marble with granite. A sample of float from the gossan contains up to 20 parts per million (ppm) silver, 1,000 ppm arsenic, 1,500 ppm lead, 1,800 ppm zinc, 20 percent iron, and 0.5 percent barium. (Dillon and others, 1981, sample 380). No sulfides were observed in the sample.
About a mile to the west, Dillon and others (1981, no. 127) collected a sample of quartz-monzonite gneiss in contact with calc-schist and skarn This sample contained about 3 percent unspecified, partly oxidized, sulfides, apparently of replacement origin It also assayed about 200 ppm lanthanum but no other anomalous metal values. The rocks in the area are granite gneiss of the Devonian Wild River Pluton, which intrudes Proterozoic or lower Paleozoic(?) schist of varying types, accompanied by some marble. (Dillon and others, 1986).
Kurtak and others (2002) searched about a mile to the southwest for mineralization described by Bliss and others (1988) as layers or veins of sphalerite and pyrite up to 8 centimeters thick in orange dolomite. They were not successful and none of the samples they collected had significant metal values. Six claims (EPI 1-6) were located by Canevex, Inc. in 1975 (Kurtak and others, 2002).
Geologic map unit (-151.313931481536, 67.3273471193835)
Mineral deposit model Several types of unclassified mineralization may be present.
Age of mineralization Possibly associated with the emplacement of a Devonian granite and quartz monzonite.
Alteration of deposit Not specifically mentioned.

Production and reserves

Workings or exploration Six claims (EPI 1-6) were located by Canevex, Inc. in 1975 (Kurtak and others, 2002). Field examination and sampling by several government agencies (Dillon and others, 1981; Kurtak and others, 2002).
Indication of production None
Reserve estimates None.
Production notes None.

References

MRDS Number A011989

References

Kurtak, J.M., Klieforth, R.F., Clark, J.M., and Maclean, E.A., 2002, Mineral investigations in the Koyukuk mining district, northern Alaska: Final Report: U.S. Bureau of Land Management Technical Report 50, v. 1 and 2, 845 p.
Reporters J.M. Britton (Anchorage); D.J. Grybeck (Contractor, USGS)
Last report date 2/1/2011