Unnamed (west of upper Davis River)

Occurrence in Alaska, United States with commodities Copper, Silver, Zinc

Geologic information

Identification information

Deposit ID 10001545
MRDS ID A012292
Record type Site
Current site name Unnamed (west of upper Davis River)

Geographic coordinates

Geographic coordinates: -130.41064, 55.83588 (WGS84)
Relative position This occurrence is at an elevation of about 2700 feet in section 4, T70S, R98E. It is near the head of an east-flowing tributary to upper Davis River and about 1.2 miles north-northeast of an unnamed lake at 3038 feet elevation. The site is in section 4, T. 70 S., R. 98 E., of the Copper River Meridian. It corresponds to area M-7 in Berg and others (1977), and to loc. 15 in Elliott and others (1978). The location is accurate within about 0.1 mile.
(click for info)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Copper Primary
Silver Secondary
Zinc Secondary

Materials information

Materials Type of material
Chalcopyrite Ore
Pyrite Ore
Pyrrhotite Ore

Alteration

  • (Local) Conspicuous iron-staining.

Host and associated rocks

  • Host or associated Host
    Rock type Metamorphic Rock > Gneiss

Nearby scientific data

(1) -130.41064, 55.83588

Comments on the geologic information

  • Geologic Description = The country rocks in the area of this occurrence are Tertiary or Cretaceous foliated granodiorite of the Coast Range batholith, and pelitic paragneiss that forms metamorphic roof pendants and screens in the batholith (Berg and others, 1977, p. 10; Berg and others, 1988). The paragneiss consists chiefly of quartz, biotite, feldspar, garnet, and sillimanite. It probably represents marine argillaceous and clastic sedimentary rocks 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 is a conspicuous zone of iron-stained paragneiss 120 feet wide and about 2 miles long (Berg and others, 1977, area M-7, p. 132 and pl. 2). The paragneiss contains small amounts of pyrite, pyrrhotite, and chalcopyrite that form small small pods parallel to the gneissic foliation. Two random chip samples across about half the width of the zone assayed up to 2 ppm Ag and 260 ppm Zn (Berg and others, 1977, p. 132).

Economic information

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic

Mining district

District name Hyder

Comments on the workings information

  • Workings / Exploration = Two random chip samples across about 60 feet of the iron-stained zone assayed up to 2 ppm Ag and 260 ppm Zn (Berg and others, 1977, p. 132).

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A012292
USGS Alaska Resource Data File ARDF KC015

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 = Sparsely disseminated base-metal sulfides
Deposit Other Comments = 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