Unnamed (on Rock Candy Creek)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Ag; Cu; Pb; Zn
Ore minerals chalcopyrite; galena; pyrite; sphalerite
Gangue minerals quartz; sericite

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale B-2
Latitude 63.3005
Longitude -144.6738
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at an elevation of about 4,400 feet on the south side of Rock Candy Creek, about 1.5 miles above its mouth. It is in the NW1/4 section 3, T. 19 S., R. 16 E., Fairbanks Meridian. The location accurate.

Geologic setting

Geologic description

Massive sulfide boulders are sparsely distributed in the drainage of Rock Candy Creek. Follow-up work to locate their source led to the discovery of 4- to 6-inch-thick massive and disseminated, volcanogenic sulfide lenses as well as multiple, but thin, hydrothermal veins with appreciable amounts of base and precious metals. Samples contain as much as 4 percent zinc, 1.5 percent lead, 0.1 percent copper, and 1 to 2 ounces per ton silver. Lenses of massive pyrrhotite 4 to 8 inches thick were found on the north side of Rock Candy Creek in quartz-sericite schist exposed on a dip slope. The pyrrhotite contains trace sphalerite, chalcopyrite, and galena (R.A. Blakestad and others, unpublished Resource Associates of Alaska, Inc. report, 1976).
This occurrence is in the Jarvis Creek Glacier subterrane of Devonian age (Nokleberg and others, 1992). This subterrane consists of a complex sequence of volcaniclastic metasedimentary rocks, predominantly of intermediate composition. The unit includes felsic and mafic metavolcanic units and metasedimentary rocks, including calcareous schist, dolomite, limestone, siltstone, quartzite, and black carbonaceous schist. The rock units are typically thin bedded, strike northwest, and dip moderately southwest. The schistosity and folds are generally parallel to the regional strike but with local exceptions (R.A. Blakestad and others, unpublished Resource Associates of Alaska, Inc. report, 1976). The metamorphosed volcanic and sedimentary rocks have been intruded by several gabbro and mafic sills and dikes and plutons of felsic to intermediate composition (R.A. Blakestad and others, unpublished Resource Associates of Alaska, Inc. report, 1976).
Geologic map unit (-144.676044028325, 63.300115790817)
Mineral deposit model Kuroko massive sulfide (Cox and Singer, 1986; model 28a).
Mineral deposit model number 28a
Age of mineralization Devonian or younger, on the basis of the age of the host rocks, which are in the Jarvis Creek Glacier subterrane (Nokleberg and others, 1992).

Production and reserves

Workings or exploration This occurrence has only had limited surface sampling.
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