Unnamed (north of the glacier at the head of the West Fork Robertson River)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Fe
Other commodities Cu; Zn
Ore minerals chalcopyrite; pyrite; sphalerite
Gangue minerals chlorite; quartz; sericite

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale B-2
Latitude 63.3019
Longitude -144.9005
Nearby scientific data Find additional scientific data near this location
Location and accuracy This unnamed occurrence lies northwest of Mount Kimball between the Johnson Glacier and an unnamed glacier at the head of the West Fork Robertson River. It is at an elevation of about 5,000 feet elevation and 8.8 miles east-southeast of Mount Gakona, in the NE1/4NE1/4 section 5, T. 19 S., R. 15 E., Fairbanks Meridian. The location is accurate.

Geologic setting

Geologic description

During reconnaissance work in 1978, Resource Associates of Alaska, Inc. discovered massive sulfide mineralization with pyrite, chalcopyrite, and sphalerite in talus (R.A. Blakestad and others, unpublished Resource Associates of Alaska Inc. report, 1978). There is no indication of any further work. Samples contained less than 0.1 percent copper, lead, and zinc.
This occurrence is in metavolcanic and subordinate metasedimentary rocks that are included in the Hayes Glacier subterrane, which is Devonian and older (Nokleberg and others, 1992).
Geologic map unit (-144.902738334398, 63.3015095551136)
Mineral deposit model Kuroko massive sulfide (Cox and Singer, 1986; model 28a).
Mineral deposit model number 28a
Age of mineralization Devonian and older, on the basis of the age of the host rock, which is in the Hayes Glacier subterrane (Nokleberg and others, 1992).

Production and reserves

Workings or exploration During reconnaissance work in 1978, Resource Associates of Alaska, Inc. discovered mineralized dolomite-quartz breccia with disseminated sphalerite and galena in talus (Rodney A. Blakestad and others, unpublished Resource Associates of Alaska Inc. report, 1978). There is no record of any further work at this site.
Indication of production None

Additional comments

Unpublished data cited is available for viewing by contacting Grayd Resources Inc. in Vancouver, B. C., Canada (www.grayd.com), or Northern Associates Inc. in Fairbanks, Alaska.

References