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

Occurrence, Inactive

Commodities and mineralogy

Main commodities Pb; Zn
Ore minerals galena; sphalerite
Gangue minerals chlorite; quartz; sericite

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale B-2
Latitude 63.3097
Longitude -144.9196
Nearby scientific data Find additional scientific data near this location
Location and accuracy This unnamed occurrence is in the rugged mountains between the Johnson Glacier and the unnamed glacier at the head of the West Fork Robertson River. It is at an elevation of about 6,400 feet and 8.1 miles east-southeast of Mount Gakona, in the NW1/4SW1/4 section 32, T. 18 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 mineralized dolomite-quartz breccia with disseminated sphalerite and galena in talus (R.A. Blakestad and others, unpublished Resource Associates of Alaska Inc. report, 1978). There is no record of any additional exploration work at this site. The rock assayed 2 to 5 percent zinc, 1.5 percent lead, and 2 to 3 ounces of silver per ton.
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 (-144.92183852184, 63.3093092504172)
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mineralized dolomite-quartz breccia with disseminated sphalerite and galena in talus (Rodney A. Blakestad and others, unpublished Resource Associates of Alaska Inc. report, 1978).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Unpublished data cited is available for viewing by contacting Grayd Resources Inc. in Vancouver, B. C., Canada (www.grayd.com), or Northern Associates Inc. in Fairbanks,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