Pass Lake West

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

Geologic information

Identification information

Deposit ID 10003603
MRDS ID A106361
Record type Site
Current site name Pass Lake West

Geographic coordinates

Geographic coordinates: -154.55268, 60.40942 (WGS84)
Relative position An extensive arcuate shaped occurrence centered approximately at a point 8 km upstream from the mouth of an unnamed northwest flowing tributary of the Koksetna River. The occurrence extends roughly 6.5 km northwest and 8 km south of this location and is about 2.9 km wide. Locality 15 of Nelson and others (1985) and locality 23 of MacKevitt and Holloway (1977). Sec. 30, T. 4 N., R. 30 W., of the Seward Meridian. Locality accurate within 1.6 km.
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Geographic areas

Country State
United States Alaska


Commodity Importance
Silver Primary
Copper Primary
Molybdenum Secondary
Zinc Secondary


  • (Local) Unknown

Mineral occurrence model information

Model code 79
USGS model code 21a
Deposit model name Porphyry Cu-Mo
Mark3 model number 2

Nearby scientific data

(1) -154.55268, 60.40942

Comments on the geologic information

  • Geologic Description = Weak geochemical anomalies associated with granite and rhyolite that may include breccia pipes. Granite is less fractured and iron-stained than rhyolite (Nelson and others, 1985).? the granite is part of the numerous, mostly quartz monzonite intrusive bodies found in the central part of the Lake Clark 1:250,000 scale quadrangle mapped and identified by Eakins and others (1978); (Nelson and others, 1983; unit TKi5). One of these plutons yielded a potassium-argon biotite age of 71.3 +/- 2.1 m.y. (Eakins and others, 1978). The rhyolite is part of unit Tv. Unit Tv is described by Nelson and others (1983) to include: rhyolitic breccia, ash-flow tuff, flows, and intrusive rocks and subordinate mafic to intermediate flows. Potassium-argon ages for this unit (Tv) range from 56.2 to 62.7 m.y. indicating a Tertiary age for these rocks (Eakins and others, 1978).
  • Age = Late Cretaceous or younger. Rocks of the quartz monzonite unit yielded a potassium-argon biotite age of 71.3 +/- 2.1 m.y. (Eakins and others, 1978). Potassium-argon ages for the rhyolite, unit Tv, range from 56.2 to 62.7 m.y. (Eakins and others, 1978)

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 = Unknown, although Resource Associates of Alaska (1976) completed a sampling program that identified the occurrence.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A106361
USGS Alaska Resource Data File ARDF LC025

Bibliographic references

  • Deposit

    Resource Associates of Alaska, Inc., 1976, Geology and geochemistry of certain land within the Lake Clark National Park: Contract report for U.S. Bureau of Mines, 109 p.

  • Deposit

    Eakins, G.R., Gilbert W.G., and Buntzen, T.K., 1978, Preliminary bedrock geology and mineral resource potential of west-central Lake Clark quadrangle, Alaska: Alaska Division of Geological and Geophysical Surveys Open-File Report 118, 15 p.

  • 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

    MacKevett, E.M., Jr., and Holloway, C.D., 1977, Map showing metalliferous mineral deposits in the western part of southern Alaska: U.S. Geological Survey Open-File Report 77-169-F, 38 p., 1 sheet, scale 1:1,000,000.

Comments on the references

  • Primary Reference = Nelson and others, 1985

General comments

Subject category Comment text
Deposit Model Name = Porphyry Cu - Mo ? (Cox and Singer, 1986; model 21a ?)
Deposit Other Comments = Site is in Lake Clark National Park and Preserve.

Reporter information

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