Glacier Fork

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

Geologic information

Identification information

Deposit ID 10002132
MRDS ID A013023
Record type Site
Current site name Glacier Fork

Geographic coordinates

Geographic coordinates: -153.2088, 60.8564 (WGS84)
Relative position Occurrence is on a peak surrounded by glaciers in the Neacola Mountains, central portion of the Lake Clark D-1 quadrangle. Locality 5 of Nelson and others (1985). SE1/4NE1/4 sec. 20, T. 9 N., R. 22 W., of the Seward Meridian. Accurate within 450 meters.
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Geographic areas

Country State
United States Alaska


Commodity Importance
Gold Primary
Copper Primary
Silver Secondary
Zinc Secondary

Materials information

Materials Type of material
Arsenopyrite Ore
Chalcopyrite Ore
Pyrrhotite Ore
Sphalerite Ore
Garnet Gangue


  • (Local) Unknown

Mineral occurrence model information

Model code 59
USGS model code 18b
Deposit model name Skarn Cu
Mark3 model number 8

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Granitoid > Granite
    Stratigraphic age (youngest) Pliocene
  • Host or associated Host
    Rock type Sedimentary Rock > Carbonate > Limestone

Nearby scientific data

(1) -153.2088, 60.8564

Comments on the geologic information

  • Geologic Description = Nelson and others (1985) describe a high-grade, iron-poor, garnet-rich skarn deposit that consists of marble interbedded with schist and phyllite and metamorphosed mafic volcanic rocks in a large roof pendant in granitic rocks (Nelson and others, 1983). Mineralization consists of layers and veinlets of massive to disseminated pyrrhotite, chalcopyrite, arsenopyrite, and sphalerite. Nokleberg and others (1987) reported chip samples grading 20 g/t Ag, 0.38 g/t Au, 0.76 percent Cu, 3.4 percent Zn. Similar occurrences include the two unnamed occurrences (ARDF number LC002 and LC010) in the Neacola Mountains.? According to Nelson and others (1983, unit MzPzm), some of the metasedimentary rocks may correlate with the Kakhonak Complex of Permian (?), Triassic, and Jurassic age in the Iliamna quadrangle, and some may be graywacke of Jurassic and Cretaceous (?) age that has been metamorphosed by nearby plutonic rocks. Some of the metamorphosed volcanic rocks, especially in roof pendants, are probably part of the volcanic rocks of Tertiary age (Tv).
  • Age = Permian through Tertiary .

Economic information

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Bristol Bay

Comments on the production information

  • Production Notes = No production

Comments on the reserve resource information

  • Reserves = No reserves

Comments on the workings information

  • Workings / Exploration = Nokleberg and others (1987; 1997) reported chip samples grading 20 g/t Ag, 0.38 g/t Au, 0.76 percent Cu, 3.4 percent Zn.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A013023
USGS Alaska Resource Data File ARDF LC008

Bibliographic references

  • Deposit

    Nelson, W.H., Carlson, C., and Case, J.E., 1983, Geologic map of the Lake Clark quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-1114-A, scale 1:250,000.

  • Deposit

    Nokleberg, W.J., Bundtzen, T.K., Berg, H.C., Brew, D.A., Grybeck, D.J., Robinson, M.S., Smith, T.E., and Yeend, W., 1987, Significant metalliferous lode deposits and placer districts of Alaska: U.S. Geological Survey Bulletin 1786, 104 p.

  • Deposit

    Nokleberg, W.J., Bundtzen, T.K., Dawson, K.M., Eremin, R.A., Goryachev, N.A., Koch, R.D., Ratkin, V.V, Rozenblum, I.S., Shpikerman, V.I., Frolov, Y.F., Gorodinsky, M.E., Melnikov, V.D., Diggles, M.F., Ognyanov, N.V., Petrachenko, E.D., Petrochenko, R.I., Pozdeev, A.I., Ross, K.V., Wood, D.H., Grybeck, D., Khanchuck, A.I., Kovbas, L.I., Nekrasov, I.Y., and Sidorov, A.A., 1997, References for significant metalliferous and selected non-metalliferous lode mineral deposits and placer districts, and for metallogenesis of the Russian Far East, Alaska, and the Canadian Cordillera: U.S. Geological Survey Open-File Report 96-513-B, 385 p.

  • Deposit

    Nelson, W.H., King, H.D., Case, J.E., Tripp, R.B., Crim, W.D., and Cooley, E.F., 1985, Mineral resource map of the Lake Clark quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-1114-B, 1 sheet, scale 1:250,000.

Comments on the references

  • Primary Reference = Nelson and others, 1985

General comments

Subject category Comment text
Deposit Model Name = Cu skarn (Cox and Singer, 1986; model 18b)
Deposit Other Comments = Discovered in 1978 by B.L. Reed. Referenced in Nelson and others, 1985, locality 5 as 'B.L. Reed and D.R. Cox, Oral Communication, 1980.' Site is in Lake Clark National Park and Preserve.?

Reporter information

Type Date Name Affiliation Comment
Reporter 15-JUN-1998 M.L. Miller U.S. Geological Survey
Reporter 15-JUN-1998 D.P. Bickerstaff U.S. Geological Survey