1. Mineral Resources
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  3. Mineral Resource Data System (MRDS)

Bear Mountain

Occurrence in Alaska, United States with commodities Molybdenum, Tungsten, Lead
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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. Host and associated rocks
  9. Nearby scientific data
  10. Economic information about the deposit and operations
  11. Mining district
  12. Links to other databases
  13. Bibliographic references
  14. General comments
  15. Reporter information

Geologic information

Identification information

Deposit ID 10001758
MRDS ID A012545
Record type Site
Current site name Bear Mountain
Related records 10257765

Geographic coordinates

Geographic coordinates: -142.15319, 68.36988 (WGS84)
Relative position Location is approximate center of area 1.25 mi (2 km) (east-west) by 0.35 mi (0.55 km )(north-south) of anomalous samples 517-521 and 608-13 of Barker (1981, pl. A-3); about 4 mi (6.4 km) southwest of Bear Mountain summit; known to within 2000 ft (610 m).???

Site location context

Political divisions (FIPS codes)

Yukon-Koyukuk(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Table Mountain B-2(quadrangle 1:63,360 scale)

Table Mountain SW(quadrangle 1:100,000 scale)

Table Mountain C(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Alaska(hydrologic region)

Federal lands

Arctic 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
Molybdenum Primary
Tungsten Critical Primary
Lead Primary

Comments on the commodity information

  • Gangue = K-feldspar
  • Ore Material = Unidentified secondary ferromolybdate mineral
  • Ore Material = Unidentified secondary ferromolybdate mineral

Materials information

Materials Type of material
Galena Ore
Molybdenite Ore
Wolframite Ore
Goethite Gangue
Hematite Gangue
Jarosite Gangue
Kaolinite Gangue
Limonite Gangue
Magnetite Gangue
Muscovite Gangue
Quartz Gangue
Rutile Gangue
Topaz Gangue

Alteration

  • (Local) Core of sericitic and argillic alteration with outer zone of silicification; local peripheral areas of pyritic and propylitic alteration.

Host and associated rocks

  • Host or associated Associated
    Rock type Metamorphic Rock > Metasedimentary Rock
    Stratigraphic age (youngest) Mississippian
  • Host or associated Host
    Rock type Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Rhyolite

Nearby scientific data

(1) -142.15319, 68.36988
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = Tungsten-rich porphyry molybdenum occurrence. Area of about 1 sq km underlain by altered complex of rhyolite porphyry, quartz porphyry, and a pipe-shaped core of intrusive breccia about 300 m in diameter; complex is cut by dikes of rhyolite porphyry and aplite. Mineralized area defined by Mo-rich gossan zone trending NW for 1.5 km over 40 ha area characterized by soil samples containing 600 ppm Mo or greater; nearly coincident with 30 ha area of soil samples containing 500 ppm W or greater. Total area of Mo + W mineralization about 50 ha; vertical and horizontal zonation evident. Central Mo-rich gossan zone, outer zone of wolframite-topaz mineralization in a Fe-enriched upper-level phase of the complex below a silicified cap, and peripheral zone of Pb-enrichment. Sulfides have largely been oxidized to limonite, hematite, goethite, jarosite, and secondary ferromolybdates; wolframite occurs as disseminated grains in porphyritic rock, quartz veins, and silicified gossan. Molybdenite and galena have each been noted in only one locality. Tertiary rhyolite porphyry stock intrudes Mississippian and older metasedimentary rocks (Barker, 1981, p. 33-40, 106-137).

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Sheenjek

Comments on the workings information

  • Workings / Exploration = Rock samples taken in 1983 contain 0.1-0.8% M, 0.06-0.6% W, 2.2% F, 60-120 PPM Nb as reported in Barker and Swainbank (1985); soil sample 2521 on p. 141 of Barker (1981) from area of intrusive breccia contains 4900 ppm Mo, 860 ppm W, 400 ppm Pb and 9.7 ppm U (Barker, 1981, p. 140-150).

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Barker (1981)

General comments

Subject category Comment text
Deposit Model Name = Lode; Mo-W porphyry breccia
Deposit Other Comments = Part of regional E-W trend of small domes, intrusions and doubly-plunging anticlines.

Reporter information

Type Date Name Affiliation Comment
Reporter 20-SEP-1996 K.R. Leonard U.S. Geological Survey
Reporter 20-SEP-1996 D.F. Huber U.S. Geological Survey
Reporter 20-SEP-1996 J.M. Schmidt U.S. Geological Survey
Reporter 20-SEP-1996 J.H. Dover U.S. Geological Survey

Beyond USGS

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

Maps centered on this site

Authoritative Alaska resources

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