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Unnamed

Occurrence in Alaska, United States with commodities Thorium, Uranium, Tin, Zirconium
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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 10308653
Record type Site
Current site name Unnamed

Geographic coordinates

Geographic coordinates: -154.07082, 62.04547 (WGS84)
Relative position This unnamed occurrence is located at the base of a cliff face on the east side of an unnamed, glacially carved, second order tributary of the Middle Fork of the Kuskokwim River. The occurrence is about three kilometers upstream from the mouth of the unnamed tributary and immediately downslope from an active valley glacier terminous at an elevation of 3,950 feet (1,204 m) in the NE1/4 sec. 32, T. 23 N., R. 26 W., of the Seward Meridian. The reporter briefly visited the site in 1982.

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-3(quadrangle 1:63,360 scale)

McGrath SE(quadrangle 1:100,000 scale)

McGrath C(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
Thorium Primary
Uranium Primary
Tin Critical Secondary
Zirconium Critical Secondary

Comments on the commodity information

  • Ore Material = uranothorite

Materials information

Materials Type of material
Thorite Ore
Feldspar Gangue
Quartz Gangue

Alteration

  • Feldspars are altered to clay minerals; quartz is a 'smokey' variety, possibly due to radioactive decay.

Mineral occurrence model information

Model code 28
USGS model code 11b
Deposit model name Alkaline margin fluorite

Nearby scientific data

(1) -154.07082, 62.04547
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = The occurrence consists mainly of several feldspar-hematite-quartz veins infilling joints and fractures in the Windy Fork composite pluton about one mile from the contact zone with sandstone and limestone of the Lower to mid-Paleozoic Dillinger subterrane (Reed and Miller, 1980; Gilbert and others, 1988; Bundtzen, Harris, and Gilbert, 1997). The individual joint fillings are 3 to 6 centimeters thick and continue for 2 to 3 meters along strike. Much of the mineralization trends N65W. Feldspars are typically altered to a clay matrix; quartz is the 'smokey' variety due to radioactive(?) decay (Gunter and others, 1993). Green-to-purple fluorite is common in talus but was not recognized in place. Composite grab samples of quartz-feldspar-hematite joint-filled material reported by Reed and Miller (1980) contain up to 490 ppm uranium and 376 ppm thorium.
  • Age = Late Tertiary, based on age (25Ma) of Windy Fork composite pluton (Solie and others, 1991).

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 reserve resource information

  • Reserves = None estimated.

Comments on the workings information

  • Workings / Exploration = The occurrence was found by the late Bruce Reed while conducting mineral resource investigations and regional geologic mapping for the U.S. Geological Survey in the western Alaska Range (Reed and Miller, 1980). Composite grab samples of quartz-feldspar-hematite joint-filled material as reported by Reed and Miller (1980) contain up to 490 ppm uranium and 376 ppm thorium.

Reference information

Comments on the references

  • Primary Reference = Reed and Miller, 1980

General comments

Subject category Comment text
Deposit Model Name = Thorium-Rare Earth veins (Cox and Singer, 1986; model 11b).
Deposit Other Comments = See Eudialyte Prospect (MG036).

Reporter information

Type Date Name Affiliation Comment
Reporter 25-NOV-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.