Unnamed (northwest of Takahula River)

Occurrences, Inactive

Commodities and mineralogy

Main commodities Sn; Zn
Other commodities Be; Bi; Mo

Geographic location

Quadrangle map, 1:250,000-scale SP
Quadrangle map, 1:63,360-scale B-2
Latitude 67.36
Longitude -153.99
Nearby scientific data Find additional scientific data near this location
Location and accuracy The site represents two occurrences in a northeast-trending, two-mile-long area, about 2.5 miles northwest of the Takakula River. The approximate center of the area is in the NW1/4 of sec. 33, T. 23 N., R. 22 E., of the Kateel River Meridian. The location is accurate to within 2000 ft. The site corresponds to localities 50 and 51 of Grybeck and Nelson (1981).

Geologic setting

Geologic description

Both occurrences are in or adjacent to Devonian granite near the contact with Paleozoic rocks (Nelson and Grybeck, 1980). The occurrences consist of a grab sample of black phyllite about 100 m from altered granite and several samples of marble, calc-silicate rocks, and gneissic granite. Selected samples contain 200 ppm Be, 30 and 50 ppm Bi, 20 ppm Mo, 100 and 5000 ppm Sn, and 700 ppm Zn. The occurrences are similar to other skarn deposits in the Brooks Range (Newberry and others, 1986).
Geologic map unit (-153.992802943194, 67.3595062611795)
Mineral deposit model Skarn (Cox and Singer, 1986; model 14b)
Mineral deposit model number 14b
Age of mineralization Devonian; related to the intrusion of Devonian pluton.
Alteration of deposit Contact metamorphic.

Production and reserves

Indication of production None

Additional comments

Located within Gates of the Arctic National Park.

References

MRDS Number 10308335

References

Reporters S.W. Nelson (Anchorage, Alaska)
Last report date 9/21/1999