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  3. Mineral Resource Data System (MRDS)

Thorpe

Past Producer in Alaska, United States with commodities Gold, Silver
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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. Nearby scientific data
  8. Economic information about the deposit and operations
  9. Mining district
  10. Links to other databases
  11. Bibliographic references
  12. General comments
  13. Reporter information

Geologic information

Identification information

Deposit ID 10000931
MRDS ID A011599
Record type Site
Current site name Thorpe
Related records 10234261

Geographic coordinates

Geographic coordinates: -149.42768, 61.74261 (WGS84)
Relative position Along the West Fork of Grubstake Gulch, marked with a quarry symbol and labeled 'Thorpe Mine' on the Anchorage C-7 1:63,360-scale topographic map. Accurate within 400 ft. Locality 19 of Ray (1933, plate 11), locality 1 from Cobb (1972), and locality 1 of MacKevett and Holloway (1977).

Site location context

Political divisions (FIPS codes)

Matanuska-Susitna(Borough)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Anchorage C-7(quadrangle 1:63,360 scale)

Anchorage NW(quadrangle 1:100,000 scale)

Anchorage(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Lower Susitna River(hydrologic unit)

Susitna River(hydrologic accounting unit)

South Central Alaska(hydrologic subregion)

Alaska(hydrologic region)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Gold Primary
Silver Secondary

Materials information

Materials Type of material
Gold Ore
Silver Ore
Quartz Gangue

Nearby scientific data

(1) -149.42768, 61.74261
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = Quartz stringers and veins up to 3.5 ft wide in shear zones that cut foliation and bedding of Jurassic (?) quartz-albite-chlorite (+/- garnet-biotite) pelitic schist bedrock. Veins strike N 50 W, and dips 53 NE (Ray, 1954). Shear zones at Thorpe mine have different attitudes from those of productive veins in tonalite commonly found in region. Veins in schist at Thorpe were the probable source of placer gold in Willow Creek and Grubstake Gulch. Assays show $25.92 Au (Au at $20.67/oz). The gold occurs principally as native metal, but it contains more silver than that from the veins (to the north) in the quartz diorite (Ray, 1933).
  • Age = Jurassic or younger; veins cut Jurassic pelitic schist.

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Willow Creek

Comments on the production information

  • Production Notes = Mining reported 1924-1925 and 1942-1943, amount of production not known.

Comments on the workings information

  • Workings / Exploration = Staked prior to 1924. Developed by several hundred feet of workings; open cuts and several adits, however only one crosscut was accessible in 1950. Reportedly a mill and tram were installed prior to 1942. Ray (1933) reported assays to show $25.92 Au (Au at $20.67/oz).

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Ray, 1954

General comments

Subject category Comment text
Deposit Other Comments = Thorpe is the only productive mine in the Willow Creek district in schist rather than intrusive rocks (Ray, 1954).

Reporter information

Type Date Name Affiliation Comment
Reporter 30-JUL-1998 D.P. Bickerstaff U.S. Geological Survey
Reporter 30-JUL-1998 S.W. Huss U.S. Geological Survey

Beyond USGS

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

External references

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.