Northwest Fork of Coghill River

Occurrence in Alaska, United States with commodity Gold

Geologic information

Identification information

Deposit ID 10003437
MRDS ID A106194
Record type Site
Current site name Northwest Fork of Coghill River

Geographic coordinates

Geographic coordinates: -147.74259, 61.13957 (WGS84)
Relative position Northwest fork of the Coghill River (north of Coghill Lake). Accurate within 2 miles. Locality P-38 of Jansons and others (1984) and locality P-32 of Hoekzema and Fechner (1986).
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Gold Primary

Materials information

Materials Type of material
Gold Ore

Mineral occurrence model information

Model code 119
USGS model code 39a
BC deposit profile C01. C02
Deposit model name Placer Au-PGE
Mark3 model number 54

Nearby scientific data

(1) -147.74259, 61.13957

Comments on the geologic information

  • Geologic Description = According to Jansons and others (1984), gold is found in thin, poorly to moderately sorted alluvial gravels and concentrated on and in slate bedrock exposed in the canyon of the northwest fork of Coghill River. A small amount of gravel occurs in the canyon, but a substantial amount has accumulated above its junction with the main fork of the Coghill River. ? Three alluvium samples contained 0.0004 to 0.0063 oz Au/cubic yard. Gold nuggets up to 1/16 in diameter was recovered (Jansons and others, 1984).
  • Age = Quaternary

Economic information

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Prince William Sound

Comments on the production information

  • Production Notes = There is no recorded production, however Hoekzema and Fechner (1986) report the potential for mineral development to be moderate for suction dredging. The grades are low to marginal, but there is a good possibility of identifying local economic concentrations of gold.

Comments on the workings information

  • Workings / Exploration = Three alluvium samples contained 0.0004 to 0.0063 oz Au/cubic yard. Gold up to 1/16 in diameter was recovered. Considerable arsenopyrite was also recovered (Jansons and others, 1984).

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A106194
USGS Alaska Resource Data File ARDF AN139

Bibliographic references

  • Deposit

    Jansons, Uldis, Hoekzema, R.B., Kurtak, J.M., and Fechner, S.A., 1984, Mineral occurrences in the Chugach National Forest, Southcentral Alaska: U.S. Bureau of Mines Open-File Report 5-84, 218 p., 2 sheets, scale 1:250,000.

  • Deposit

    Hoekzema, R.B., and Fechner, S.A., 1986, Placer Gold sampling in and near the Chugach National Forest, Alaska: U.S. Bureau of Mines Information Circular 9091, 42 p.

Comments on the references

  • Primary Reference = Jansons and others, 1984

General comments

Subject category Comment text
Deposit Model Name = Placer Au (Cox and Singer, 1986; model 39a)

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