Unnamed (overlooking Middle Fork of Kuskokwim River)

Occurrence in Alaska, United States with commodities Silver, Iron, Molybdenum
Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Commodities
  6. Materials information
  7. Mineral occurrence model information
  8. Nearby scientific data
  9. Economic information about the deposit and operations
  10. Mining district
  11. Links to other databases
  12. Bibliographic references
  13. General comments
  14. Reporter information

Geologic information

Identification information

Deposit ID 10307841
Record type Site
Current site name Unnamed (overlooking Middle Fork of Kuskokwim River)

Geographic coordinates

Geographic coordinates: -154.45284, 62.22746 (WGS84)
Relative position The unnamed occurrence is located in a low saddle overlooking the Middle Fork of the Kuskokwim River at an elevation of 3,000 feet (915 m) in the SW1/4 sec. 27, T. 25 N., R. 28 W., of the Seward Meridian. The reporter visited the site in 1998 at station no. 98BT440.

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
Silver Primary
Iron Secondary
Molybdenum Secondary

Materials information

Materials Type of material
Molybdenite Ore
Pyrite Ore
Epidote Gangue
Quartz Gangue

Mineral occurrence model information

Model code 58
USGS model code 18a
Deposit model name Porphyry Cu, skarn-related
Mark3 model number 9

Nearby scientific data

(1) -154.45284, 62.22746

Economic information

Comments on the geologic information

  • Geologic Description = This unnamed occurrence is a skarn zone developed in a highly sheared limestone of Late Triassic age, a part of the Mystic subterrane (Gilbert and others, 1988; Bundtzen, Harris, and Gilbert, 1997). Massive pyrite bands averaging 8 centimeters in thickness occur in association with epidote-quartz gangue within a 10 meter wide skarn zone near a gabbro-diorite sill. One grab sample contained 10.75 percent iron, 100 ppm molybdenum, and 1.25 grams/tonne silver (T.K. Bundtzen and G.M. Laird, written communication, 1998).

Economic information about the deposit and operations

Development status Occurrence

Comments on exploration

  • Status = Inactive

Mining district

District name McGrath

Comments on the workings information

  • Workings / Exploration = This unnamed occurrence was investigated in 1998. One grab sample contained 10.75 percent iron, 100 ppm molybdenum, and 1.25 grams/tonne silver (T.K. Bundtzen and G.M. Laird, written communication, 1998).

Reference information

Comments on the references

  • Primary Reference = This description

General comments

Subject category Comment text
Deposit Model Name = Iron-rich skarn (Cox and Singer, 1986; model 18a).

Reporter information

Type Date Name Affiliation Comment
Reporter 22-DEC-98 T.K. Bundtzen Pacific Rim Geological Consulting

Beyond USGS

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

Authoritative Alaska resources

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