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Bowser Creek-Main

Past Producer in Alaska, United States with commodities Silver, Lead, Zinc, Arsenic, Gold, Cadmium, Cobalt, Copper
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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. Mineral occurrence model information
  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 10308920
MRDS ID A015035
Record type Site
Current site name Bowser Creek-Main
Related records 10002598

Geographic coordinates

Geographic coordinates: -153.70282, 62.17948 (WGS84)
Relative position The Bowser Creek-Main deposit is located along the steep, eastern margin of an active rock glacier in Bowser Creek valley; it is at an approximate elevation of 4,200 feet (1,280 m) in sec. 9, T. 24 N., R. 24 W., of the Seward Meridian. Location accurately determined; reporter visited the site in 1982 and 1988.

Site location context

Political divisions (FIPS codes)

Yukon-Koyukuk(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

McGrath A-2(quadrangle 1:63,360 scale)

McGrath SE(quadrangle 1:100,000 scale)

McGrath(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Upper Kuskokwim River(hydrologic accounting unit)

Southwest(hydrologic subregion)

Alaska(hydrologic region)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Silver Primary
Lead Primary
Zinc Critical Primary
Arsenic Critical Secondary
Gold Secondary
Cadmium Secondary
Cobalt Critical Secondary
Copper Secondary

Materials information

Materials Type of material
Chalcopyrite Ore
Galena Ore
Marcasite Ore
Pyrite Ore
Pyrrhotite Ore
Sphalerite Ore
Amphibole Gangue
Calcite Gangue
Epidote Gangue
Garnet Gangue
Hedenbergite Gangue
Quartz Gangue

Alteration

  • Pyrrhotite and iron-rich sphalerite (marmatite) ubiquitously weather to a deep reddish brown gossan.

Mineral occurrence model information

Model code 60
USGS model code 18c
Deposit model name Skarn Zn-Pb
Mark3 model number 22

Nearby scientific data

(1) -153.70282, 62.17948
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = The Bowser Creek-Main deposit consists of replacement pods, lenses and veins of sphalerite, galena, pyrrhotite, and minor chalcopyrite, marcasite, and pyrite in skarn adjacent to felsic dikes. However, important fissure-controlled, silver-rich galena, tetrahedrite, pyrrhotite, and calcite mineralization occurs in marble away from the skarn itself. Sphalerite is iron-rich (marmatite). Galena is paragenetically late and crosscuts the earlier sphalerite-chalcopyrite veins and replacement bodies. No sulfosalts were recognized. The skarns and replacement deposits at the Bowser Creek-Main deposit are related to a dumbell-shaped, 7 square kilometer, composite pluton that intrudes a limestone rich section of the Barren Ridge Limestone, a unit of the Dillinger subterrane (Bundtzen, Harris, and Gilbert, 1997). A quartz porphyry phase of the Bowser Creek pluton has been radiometrically dated at 60.4 Ma (Bundtzen and others, 1988). Prospect sketches were provided by Reed and Elliott (1968, C 596). The richest silver concentrations occur in shear-zone controlled massive galena-sulfide veins. Reed and Elliott (1968, C 596) reported values of up to 9,635.0 grams/tonne silver, 60.00 percent lead, 14.70 percent zinc, 0.49 percent copper, and 0.4 grams/tonne gold. Bundtzen and others (1988) reported that the average of six high-grade samples of massive galena ore from shear zones in the marble front contained 2,510.0 grams/tonne silver, 23.70 percent lead, 3.44 percent zinc, 0.15 percent copper, and 110 ppb gold. Other samples collected by Bundtzen and others (1988) contained 157 ppm cobalt and 0.11 percent cadmium. Based on polished-section and assay data, silver has a highest correlation coefficient with lead (galena); cobalt is concentrated in the pyrrhotite. High cadmium values occur in sphalerite. The mineralogical source of the sporadic gold values is unknown.
  • Age = Tertiary, based on 60.4 Ma age of nearby quartz porphyry intrusion; ore mineralization not dated.

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name McGrath

Comments on the production information

  • Production Notes = Approximately 15 tons of galena-rich massive sulfide ores were sacked and eventually processed at the Sunshine Mining Company smelter in Kellogg, Idaho in 1972-73 (B.L. Reed and C.N. Conwell, written communications, 1982). These ores contained about 2,332 grams/tonne silver, about 50 percent lead, and elevated zinc, cadmium, copper, and gold. Only the lead and silver were credited at the smelter (C.N. Conwell, written communication, 1982).

Comments on the workings information

  • Workings / Exploration = The Bowser Creek-Main deposit was discovered during regional geological mapping and mineral investigations conducted in the southern Alaska Range by the U.S. Geological Survey and published in Reed and Elliott (1968, C 559 and 596) and Reed and Lanphere (1972). Portland-based, Alaskamin Mining Company and St. Eugene Mining Company, the operator for Falconbridge Mining Company, acquired the property in late 1968 (Williams, 1969) and by 1973, cut about 250 feet of surface trenches, built a 2,600-foot-long airport on the Post River, and sacked about 15 tons of high grade galena ores for air shipment to Sunshine Mining Company's Kellogg smelter in Idaho (B.L. Reed and C.N. Conwell, written communication 1982). Records from an alleged early drilling program have not been documented. Reed and Elliott (1968, C 559) reported values from surface chip samples of up to 9,635 grams/tonne silver, 60.00 percent lead, 14.70 percent zinc, 0.49 percent copper, and 0.4 grams/tonne gold. Bundtzen and others (1988) reported that the average of six high grade samples of massive galena-sulfide ores from shear zones in the marble front contained 2,510 grams/tonne silver, 23.70 percent lead, 3.44 percent zinc, 0.15 percent copper, and 110 ppb gold. Other samples collected by Bundtzen and others (1988) contained 0.11 percent cadmium and 157 ppm cobalt.

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Bundtzen and others, 1988

General comments

Subject category Comment text
Deposit Model Name = Zinc-lead skarn deposits (Cox and Singer, 1986; model 18c); low temperature lead-zinc-silver skarns after Eimaudi and Burt, (1982)
Deposit Other Comments = Part of a larger intrusive-related mineral center; see Bowser Creek-Northeast (MG067) and Bowser Creek-Headwaters (MG066) prospects.

Reporter information

Type Date Name Affiliation Comment
Reporter 13-OCT-1998 T.K. Bundtzen Pacific Rim Geological Consulting

Beyond USGS

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

Maps centered on this site

Authoritative Alaska resources

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