Unnamed (overlooking Cheeneetnuk River)

Occurrence in Alaska, United States with commodities Copper, Silver

Geologic information

Identification information

Deposit ID 10307837
Record type Site
Current site name Unnamed (overlooking Cheeneetnuk River)

Geographic coordinates

Geographic coordinates: -155.10784, 62.07245 (WGS84)
Relative position This unnamed occurrence is located on a steep east-facing bluff overlooking Cheeneetnuk River; at an elevation of 1,000 feet (305 m) in the NW1/4 sec. 23, T. 23 N., R. 32 W., of the Seward Meridian. The occurrence corresponds to prospect number no. 117 in Gilbert (1981); his station no. 78WG79. The reporter visited the site in 1989.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Copper Primary
Silver Secondary

Materials information

Materials Type of material
Pyrite Ore

Mineral occurrence model information

Model code 72
USGS model code 19a
Deposit model name Polymetallic replacement
Mark3 model number 47

Nearby scientific data

(1) -155.10784, 62.07245

Comments on the geologic information

  • Geologic Description = The unnamed occurrence is a large zone of pyritic gossan in argillite of the Upper Paleozoic Mystic subterrane near the Cheeneetnuk Thrust Fault system (Gilbert, 1981; Wilson and others, 1998). The pyrite-rich gossan can be traced for more than 300 meters of strike length; mineralized widths were not determined. A Tertiary (37.8 Ma) granite is exposed about one quarter mile from the gossan (Gilbert, 1981). Four grab samples taken along the strike of the zone consistently yielded anomalous copper and silver with values of up to 224 ppm copper and 1.9 grams/tonne silver (Gilbert, 1981).

Economic information

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 = W.G. Gilbert sampled the gossan during geologic mapping for the Alaska Division of Geological and Geophysical Surveys in 1978 (Gilbert, 1981). Four grab samples taken along the strike of the zone consistently yielded anomalous copper and silver with values of up to 224 ppm copper and 1.9 grams/tonne silver (Gilbert, 1981).

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF MG021

Bibliographic references

  • Deposit

    Gilbert, W.G., 1981, Preliminary geologic map of the Cheeneetnuk River area, Alaska: Alaska Division of Geological and Geophysical Surveys Open-File Report 153, 19 pages, 2 sheets, 1:63,360 scale.

  • Deposit

    Wilson, F.H., Dover, J.H., Bradley, D.C., Weber, F.R., Bundtzen, T.K., and Haeussler, P.J., 1998, Geologic map of central (interior) Alaska: U.S. Geological Survey Open-File Report 98-133, 17 p., 2 sheetsm, scale 1:500,000.

Comments on the references

  • Primary Reference = Gilbert, 1981

General comments

Subject category Comment text
Deposit Model Name = Polymetallic replacement (?) (Cox and Singer, 1986; model 19a).

Reporter information

Type Date Name Affiliation Comment
Reporter 10-DEC-98 T.K. Bundtzen Pacific Rim Geological Consulting