Unnamed (south shore of Walker Cove)

Occurrence in Alaska, United States with commodities Copper, Silver

Geologic information

Identification information

Deposit ID 10001555
MRDS ID A012302
Record type Site
Current site name Unnamed (south shore of Walker Cove)

Geographic coordinates

Geographic coordinates: -130.8687, 55.71282 (WGS84)
Relative position This occurrence is on the south shore of Walker Cove about 1.2 miles east of Hut Point. The site is in section 16, T. 71 S., R. 95 E., of the Copper River Meridian. It corresponds to site G-9 in Berg and others (1977, p. 135), and to loc. 25 in Elliott and others (1978). The location is accurate within about 0.1 mile.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Copper Primary
Silver Secondary

Materials information

Materials Type of material
Chalcopyrite Ore
Pyrite Ore

Host and associated rocks

  • Host or associated Host
    Rock type Metamorphic Rock > Gneiss

Nearby scientific data

(1) -130.8687, 55.71282

Comments on the geologic information

  • Geologic Description = The country rocks in the area of this occurrence consist of paragneiss metamorphic roof pendants, screens, and inclusions in Tertiary or Cretaceous foliated granodiorite and quartz diorite of the Coast Range batholith (Berg and others, 1988). The metamorphic rocks represent marine strata that underwent high-grade regional metamorphism in Cretaceous or Tertiary time. The premetamorphic age of the strata is uncertain, but they probably are mainly Paleozoic and may be as old as Precambrian (Berg and others, 1988, p. 26; Gehrels and others, 1990; Crawford and others, in press).? the occurrence consists of sulfide-bearing paragneiss (Berg and others, 1977, p. 135). The sulfides occur as thin, discontinuous layers of pyrite and sparse chalcopyrite that parallel the foliation of the paragneiss. Anomalous amounts of Cu (280 ppm) and Ag (1.5 ppm) were detected in a grab sample from this locality. A chip sample across a 38-foot section of dark gray paragneiss containing bands of light gray, slightly pyritic paragneiss assayed 1000 ppm Cu and nearly 1 ppm Ag.

Economic information

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic

Mining district

District name Ketchikan

Comments on the workings information

  • Workings / Exploration = Anomalous amounts of Cu (280 ppm) and Ag (1.5 ppm) were detected in a grab sample of pyritic paragneiss from this locality (Berg and others, 1977, p. 135). A chip sample across a 38-foot section of dark gray paragneiss containing bands of light gray, slightly pyritic paragneiss assayed 1000 ppm Cu and nearly 1 ppm Ag.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A012302
USGS Alaska Resource Data File ARDF KC025

Bibliographic references

  • Deposit

    Berg, H.C., Elliott, R.L., Smith, J.G., Pittman, T.L., and Kimball, A. L., 1977, Mineral resources of the Granite Fiords wilderness study area, Alaska, with a section on aeromagnetic data by Andrew Griscom: U.S. Geological Survey Bulletin 1403, 151 p.

  • Deposit

    Elliott, R.L., Berg, H.C., and Karl, Susan, 1978, map and table describing metalliferous and selected nonmetalliferous mineral deposits, Ketchikan and Prince Rupert quadrangles, Alaska: U.S. Geological Survey Open-file Report, 78-73-B,17 p., scale 1:250,000.

  • Deposit

    Berg, H.C., Elliott, R.L., and Koch, R.D., 1988, Geologic map of the Ketchikan and Prince Rupert quadrangles, southeastern Alaska: U.S. Geological Survey Mineral Investigations Series Map MF-1807,27 p., scale 1:250,000.

  • Deposit

    Gehrels, G.E., McClelland, W.C., Samson, S.D., Patchett, P.J., and Jackson, J.L., 1990, Ancient continental margin assemblage in the northern Coast Mountains, southeast Alaska and northwest Canada: Geology, v. 18, p. 208-211.

  • Deposit

    Crawford, M.L., Crawford, W.A., and Gehrels, G.E., 2000, Terrane assembly and structural relationships in the eastern Prince Rupert quadrangle, British Columbia, in H.H. Stowell and W.C.McClelland, eds., Tectonics of the Coast Mountains, southeastern Alaska and British Columbia: Boulder, Colorado, Geological Society of America Special Paper 343, p. 1-21.?

Comments on the references

  • Primary Reference = Berg and others, 1977

General comments

Subject category Comment text
Deposit Model Name = Disseminated base-metal sulfides in paragneiss
Deposit Other Comments = This site is in Misty Fiords National Monument Wilderness.

Reporter information

Type Date Name Affiliation Comment
Reporter 29-JUN-1999 H.C. Berg U.S. Geological Survey