West Fork

Prospect in Alaska, United States with commodities Silver, Lead, Zinc, Copper
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. Host and associated rocks
  10. Nearby scientific data
  11. Economic information about the deposit and operations
  12. Mining district
  13. Links to other databases
  14. Bibliographic references
  15. General comments
  16. Reporter information

Geologic information

Identification information

Deposit ID 10307551
Record type Site
Current site name West Fork

Geographic coordinates

Geographic coordinates: -147.49283, 63.80964 (WGS84)
Relative position The West Fork prospect is at an elevation of about 4,500 feet, in the south wall of an east-flowing branch of West Fork Little Delta River. The map site is about 4 miles southwest of the junction of Forgotten Creek, in the NW1/4 of sec. 11, T. 13 S., R. 1 E., of the Fairbanks Meridian. The location is accurate to within 0.5 mile.

Site location context

Political divisions (FIPS codes)

Southeast Fairbanks(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Healy D-1(quadrangle 1:63,360 scale)

Mount Hayes NW(quadrangle 1:100,000 scale)

Healy(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Alaska(hydrologic region)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Silver Primary
Lead Primary
Zinc Critical Primary
Copper Secondary

Materials information

Materials Type of material
Galena Ore
Pyrite Ore
Sphalerite Ore
Quartz Gangue
Sericite Gangue

Alteration

  • (Local) Quartz and sericite.

Mineral occurrence model information

Model code 184
USGS model code 28a
Deposit model name Massive sulfide, kuroko
Mark3 model number 93

Host and associated rocks

  • Host or associated Host
    Rock type
    Stratigraphic age (youngest) Late Devonian

Nearby scientific data

(1) -147.49283, 63.80964

Economic information

Comments on the geologic information

  • Geologic Description = The country rocks at the West Fork prospect are Upper Devonian(?) felsic metavolcanic rocks consisting of schist and phyllite, locally containing relict phenocrysts of quartz, orthoclase, and plagioclase (Wilson and others, 1998). The deposit consists of stratiform layers of massive pyrite, galena, and sphalerite, accompanied by quartz and sericite. Samples of a 20-30-centimeter-wide massive-sulfide horizon contained 3.68% lead, 4.05% zinc, 131 grams of silver per tonne and 0.38 grams of gold per tonne (www.grayd.com, 1999).
  • Age = Mineralization was probably syngenetic with the Upper Devonian host rocks.

Economic information about the deposit and operations

Development status Prospect

Comments on exploration

  • Status = Active

Mining district

District name Bonnifield

Comments on the workings information

  • Workings / Exploration = The prospect has been explored by surface sampling, geophysical work, and one drill hole (Inmet Mining, personal communication, 1999). Samples of a 20-30-centimeter-wide massive-sulfide horizon contained 3.68% lead, 4.05% zinc, 131 grams of silver per tonne and 0.38 grams of gold per tonne (www.grayd.com, 1999).

Reference information

Comments on the references

  • Primary Reference = www.grayd.com, 1999

General comments

Subject category Comment text
Deposit Model Name = Kuroko massive sulfide (Cox and Singer, 1986; model 28a)

Reporter information

Type Date Name Affiliation Comment
Reporter 07-APR-00 N. Van Wyck Stevens Exploration Management Corporation

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.