Unnamed (Two Plate Creek drainage area)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu
Other commodities Au
Ore minerals bornite; chalcocite; chalcopyrite
Gangue minerals carbonate mineral; epidote; quartz

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale B-6
Latitude 63.2972
Longitude -146.5903
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence, or possibly two occurrences, is on the south side of Two Plate Creek and about 2,000 feet east of the center of section 4, T. 19 S., R. 6 E., Fairbanks Meridian. The occurrence corresponds to locality 19 of Kaufman (1964), locality 23 on figure 4 of Cobb (1979 [OFR 79-238]), probably to locality 11 of Kurtak and others (1992), and possibly the Clara Marie or Kardex site number KX68-28 of Heiner and Porter (1972). Two occurrences are suggested by differences in rocks reported at the supposed site by Kaufman and by Kurtak and co-authors.

Geologic setting

Geologic description

The rocks at and near the site on the south side of Two Plate Creek are reported to include greenstone and hornblende diorite (Kaufman, 1964) and argillite, hornfels, and andesite (Kurtak and others, 1992, table A11). At Kaufman's site, mineralized talus near the south valley wall contains bornite, chalcopyrite, and chalcocite associated with quartz-epidote vein material. The area is underlain by greenstone cut by hornblende diorite (Kaufman, 1964, p. 9-10). Weakly mineralized argillite and hornfels cut by quartz and quartz-carbonate veins occur in the same general area (Kurtak and others, 1992). A sample of limonite-stained argillite cut by quartz veinlets contained 2 parts per million silver and 0.43 percent copper.
Gravel in Two Plate Creek is somewhat auriferous; pan-concentrate sample 1154 collected near the mouth of the creek had four very fine flakes of gold (Kurtak and others, 1992).
Geologic map unit (-146.592567602167, 63.296768756524)
Mineral deposit model Low-sulfide copper-bearing quartz veins; possible association with hornblende diorite intrusion or Basaltic Cu? (Cox and Singer, 1986; model 23?).
Mineral deposit model number 23?
Age of mineralization Uncertain; possible association with a hornblende diorite pluton of Cretaceous (?) age.

Production and reserves

Workings or exploration Two Plate Creek was located as a placer prospect in 1954 (U.S. Bureau of Mines, 1973); one lode claim, the Clara Marie, may have been staked for copper (Heiner and Porter, 1972, Kardex site number KX68-28).
Indication of production None



Reporters W.T. Ellis (Alaska Earth Science), C.C. Hawley (Hawley Resource Group), and W.J. Nokleberg (USGS)
Last report date 7/31/2001