Unnamed (south of upper Windy Creek)

Occurrence in Alaska, United States with commodities Copper, Silver

Geologic information

Identification information

Deposit ID 10000736
MRDS ID A011375
Record type Site
Current site name Unnamed (south of upper Windy Creek)

Geographic coordinates

Geographic coordinates: -149.14284, 63.4596 (WGS84)
Relative position This occurrence is at an elevation of about 4,200 feet south of upper Windy Creek, a tributary of the Nenana River. The site is at the junction of sections 5, 6, 7 and 8, T. 17 S., R. 8 W., of the Fairbanks Meridian. The location is accurate to within 3,000 feet. This is location 1 of Hickman and Craddock (1976).
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Copper Primary
Silver Secondary

Materials information

Materials Type of material
Chalcopyrite Ore
Malachite Ore
Pyrrhotite Ore
Calcite Gangue
Diopside Gangue
Wollastonite Gangue

Alteration

  • (Local) Skarn and subsequent weathering and oxidation.

Mineral occurrence model information

Model code 59
USGS model code 18b
Deposit model name Skarn Cu
Mark3 model number 8

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Mafic Intrusive Rock > Diorite
  • Host or associated Host
    Rock type Sedimentary Rock > Carbonate > Limestone

Nearby scientific data

(1) -149.14284, 63.4596

Comments on the geologic information

  • Geologic Description = The country rocks in the area of this occurrence are Devonian to Ordovician argillite and interbedded limestone that have been intruded by small plugs of Upper Cretaceous to Lower Tertiary quartz diorite. The deposit consists of a 3- to 9-foot-wide skarn containing discontinuous, 1- to 3-foot-thick zones of pyrrhotite and minor chalcopyrite along fractures. Weathering and oxidation have produced a heavy limonitic coating, malachite, and erythrite. Samples contain 1,900 ppm copper and 0.6 ppm silver (Hickman and Craddock, 1976).
  • Age = Late Cretaceous or younger.

Economic information

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Bonnifield

Comments on the workings information

  • Workings / Exploration = Surface sampling only. Samples contain 1,900 ppm copper and 0.6 ppm silver (Hickman and Craddock, 1976).

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A011375
USGS Alaska Resource Data File ARDF HE077

Bibliographic references

  • Deposit

    Hickman, R.G., and Craddock, Campbell, 1976, Mineral occurrences near Cantwell, southcentral Alaska: Alaska Division of Geological "&" Geophysical Surveys Special Report 13, 7 p.

  • Deposit

    Cobb, E.H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Healy quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-1062, 113 p.

Comments on the references

  • Primary Reference = Hickman and Craddock, 1976

General comments

Subject category Comment text
Deposit Model Name = Cu skarn (Cox and Singer, 1986; model 18b)
Deposit Other Comments = the site is in Denali National Park Wilderness.

Reporter information

Type Date Name Affiliation Comment
Reporter 07-APR-2000 N. Van Wyck Stevens Exploration Management Corporation