Weasel Mountain

Occurrence in Alaska, United States with commodities Copper, Molybdenum, Silver, Gold, Lead, Zinc
Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Commodities
  6. Materials information
  7. Alteration
  8. Mineral occurrence model information
  9. Host and associated rocks
  10. Nearby scientific data
  11. Economic information about the deposit and operations
  12. Mining district
  13. Links to other databases
  14. Bibliographic references
  15. General comments
  16. Reporter information

Geologic information

Identification information

Deposit ID 10094052
MRDS ID A012445
Record type Site
Current site name Weasel Mountain
Related records 10113097

Geographic coordinates

Geographic coordinates: -158.19246, 56.48929 (WGS84)
Relative position This occurrence is located approximately 2 miles northwest of Weasel Mountain and 2 miles west of Hook Bay in T. 42 and 43 S., R. 56 and 57 W., of the Seward Meridian (Cox and others, 1981, locality 4; MacKevett and Holloway, locality 25?). Location is accurate to within 1 mile.

Site location context

Political divisions (FIPS codes)

Lake and Peninsula(Borough)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Chignik B-1(quadrangle 1:63,360 scale)

Chignik SE(quadrangle 1:100,000 scale)

Chignik(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Shelikof Strait(hydrologic unit)

Kodiak-Shelikof(hydrologic accounting unit)

South Central Alaska(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

Alaska Peninsula National Wildlife Refuge(National Wildlife Refuge)

National Wildlife Refuge FWS(Type of land area)

FWS(Federal land areas administered by FWS)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Copper Primary
Molybdenum Primary
Silver Secondary
Gold Secondary
Lead Secondary
Zinc Critical Secondary

Materials information

Materials Type of material
Chalcopyrite Ore
Galena Ore
Molybdenite Ore
Pyrite Ore
Sphalerite Ore
Calcite Gangue
Quartz Gangue
Tourmaline Gangue

Alteration

  • (Local) Alteration consists of a broad sericitic zone within the area of higher sulfide content and a peripheral, patchy propylitic zone.

Mineral occurrence model information

Model code 53
USGS model code 17
Deposit model name Porphyry Cu
Mark3 model number 4
Model code 79
USGS model code 21a
Deposit model name Porphyry Cu-Mo
Mark3 model number 2

Host and associated rocks

  • Host or associated Associated
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Siltstone
    Rock unit name Meshik Formation;Meshik Formation;;
    Rock description Meshik Formation;Meshik Formation;;
  • Host or associated Host
    Rock type Metamorphic Rock > Metasedimentary Rock > Quartzite
    Rock unit name Naknek Formation;Naknek Formation
    Rock description Naknek Formation;Naknek Formation

Nearby scientific data

(1) -158.19246, 56.48929

Economic information

Comments on the geologic information

  • Geologic Description = The area of this site is underlain by strata of the Cretaceous Chignik Formation and by the interbedded sediments, volcaniclastics, and andesite of the Oligocene-Pliocene Meshik Formation.? Fields (1977) describes two major intrusive systems, a diorite porphyry dike or sill and a younger quartz porphyry mass. The diorite is approximately 1/2 mile in width and extends in a northeast direction for more than a mile. The quartz porphyry intrudes the the diorite, extends in a northeast direction, and measures approximately 700 by 3000 feet in outcrop. Butherus (1981) reports these intrusive phases as occupying approximately two square miles. Large areas of hornfels have resulted from thermal metamorphism of the nearby sedimentary rock.? the site is marked by a color anomaly which contains 1 to 6 percent sulfides over an area 2 miles in long by 1 mile wide. Fields (1977) describes the sulfides as mostly fracture controlled, primarily along certain marginal zones of the diorite and quartz porphyry and in the metasediments to the west. Chalcopyrite and sparse molybdenite occur in the marginal areas of the diorite, mostly along northeast-trending fracture zones. The resulting copper anomaly is approximately 700 by 1500 feet and contains 500 to 2100 ppm copper. The molybdenum anomaly coincides in part with the copper but has a more easterly trend. This anomaly is approximately 1000 by 2000 feet and contains 22 to 160 ppm molybdenum. Low gold values (0.04 to 0.18 ppm) coincide with the molybdenum. Diffuse peripheral lead-zinc values are present.? Alteration is diffuse with no strong focus on a core. A broad sericitic zone exists within the area of higher sulfide content. Sericite occurs pervasively and along fractures. Propylitic alteration in the sediments is patchy and consists of chlorite and epidote clots.? Butherus (1981) reports intrusive breccia near the head of a valley in the NW1/4 sec. 2, T. 43 S., R. 57 W., of the Seward Meridian. The breccia, approximately 800 feet in diameter, contains traces of chalcopyrite and sphalerite in a quartz-tourmaline matrix. Other minerals present include pyrite, calcite, and barite. One sample contained >10,000 ppm copper, 0.06 ppm gold, 13 ppm lead, 28 ppm silver, and 1800 ppm zinc. Three other samples contained up to 750 ppm copper, 0.02 to 0.04 ppm gold, and 1.2 to 11.4 ppm silver.
  • Age = Tertiary.

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Alaska Peninsula

Comments on the workings information

  • Workings / Exploration = Bear Creek Mining Company mapped and sampled this occurrence in 1975-1976, and Resource Associates of Alaska explored it in 1979 and 1981.? Copper values of 500 to 2100 ppm occur in an area of 700 by 1500 feet. Molybdenum values of 22 to 160 ppm occur in an area of 1000 by 2000 feet. Gold values are up to 0.18 ppm.

Reference information

Bibliographic references

  • Deposit

    Fields, E.D., 1977, 1976 Annual report: Alaska search, Chignik area-Bristol Bay region: Bear Creek Mining Company, 44 p., 22 map sheets. (Report held by the Aleut Corporation, Anchorage, Alaska.)

  • Deposit

    Anderson, G.D., Fitch, G.M., Lappie, D.W., Lindberg, P.A., and Fankhauser, R.E., 1979, Exploration and evaluation of Bristol Bay Native Corporation Lands, Vol. II, Book 1: prepared for Houston Oil and Minerals Company by Resource Associates of Alaska, 78 p. (Report held by Alaska Earth Science, Anchorage, Alaska.)

  • Deposit

    Butherus, D.L., White, D.C., Smith, W.H., Radford, G., Sandberg, R.J., and Pray, J.C., 1981, Exploration and evaluation of precious metal potential of Bristol Bay Native Corporation Lands, southwest Alaska, 1981, Vol. 1: Prepared for Nerco by Resource Associates of Alaska, 90 p. (Report held by Alaska Earth Science, Anchorage, Alaska.)

  • Deposit

    Cox, D.P., Detra, D.E., and Detterman, R.L., 1981, Mineral resource maps of the Chignik and Sutwik Island quadrangles, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF- 1053-K, 2 map sheets, scale 1:250,000.

  • Deposit

    Detterman, R.L., Miller, T.P., Yount, M.E., and Wilson, F.H.,1981, Geologic map the Chignik and Sutwik Island quadrangles Alaska: U.S. Geologic Survey Miscellaneous Investigations Series Map I- 1229, 1 map sheet, scale 1:250,000.

  • Deposit

    Young, L.E., St. George, P., and Bouley, B., 1997, Porphyry copper deposits in relation to the magmatic history and palinspastic restoration of Alaska, in Goldfarb, R.J., and Miller, L.D., (eds.), Mineral deposits of Alaska: Economic Geology Monograph 9, p. 306-333.

  • 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 = Fields, 1977

General comments

Subject category Comment text
Deposit Model Name = Porphyry copper; porphyry copper-molybdenum (Cox and Singer, 1986; models 17, 21a)
Deposit Model Number = 17, 21a
Deposit Other Comments = This site is partially on land selected by the Bristol Bay Native Corporation.

Reporter information

Type Date Name Affiliation Comment
Reporter 08-FEB-2000 S.H. Pilcher U.S. Geological Survey

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

Authoritative Alaska resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.