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  3. Mineral Resource Data System (MRDS)

Unnamed

Occurrence in Alaska, United States with commodities Tin, Tungsten
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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 10308658
Record type Site
Current site name Unnamed

Geographic coordinates

Geographic coordinates: -153.3918, 62.05248 (WGS84)
Relative position These unnamed occurrences are in two, second order tributary streams that enter an east-flowing third order stream that enters the South Fork of Kuskokwim River. The occurrences are in the SW1/4 sec. 30, T. 23 N., R. 22 W., of the Seward Meridian. The location(s) are based on field plots completed by Ellen E. Harris in 1988; at station nos. 88HA11-12 (Bundtzen, Harris, and Gilbert, 1997).

Site location context

Political divisions (FIPS codes)

Bethel(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

McGrath A-1(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
Tin Critical Primary
Tungsten Critical Secondary

Materials information

Materials Type of material
Cassiterite Ore

Alteration

  • None.

Mineral occurrence model information

Model code 123
USGS model code 39e
Deposit model name Alluvial placer Sn

Nearby scientific data

(1) -153.3918, 62.05248
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = These unnamed occurrences contain significant concentrations of tin and tungsten from panned heavy mineral fractions in second order stream basins. Stream gradients average 220 meters/kilometer (steep), and both gulches flow on bedrock. The area drains the contact zone of a 58 Ma granite that intrudes Lower Cretaceous flysch (Bundtzen, Harris, and Gilbert, 1997). The granite is the same age of the tin-bearing McKinley suite of plutons exposed throughout south central Alaska (Hudson and Reed, 1997). Several grains of cassiterite were identified in one pan concentrate. The mineralogical source of anomalous tungsten is unknown. Analyses of panned concentrates indicate values of 2,100 ppm and 220 ppm tin and 230 ppm and 180 ppm tungsten from both gulches.
  • Age = Quaternary.

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name McGrath

Comments on the workings information

  • Workings / Exploration = Ellen E. Harris collected the staniferous samples during geochemical studies for the Alaska Division of Geological and Geophysical Surveys in 1988 (Bundtzen, Harris, and Gilbert, 1997). Analyses of panned concentrates indicate values of 2,100 ppm and 220 ppm tin and 230 ppm and 180 ppm tungsten from both gulches.

Reference information

Comments on the references

  • Primary Reference = Bundtzen, Harris, and Gilbert, 1997

General comments

Subject category Comment text
Deposit Model Name = Alluvial placer tin (Cox and Singer, 1986; model 39e).

Reporter information

Type Date Name Affiliation Comment
Reporter 09-DEC-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

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