Ellis (Boone and Ibeck #1 and #2)

Prospect in Alaska, United States with commodities Copper, Silver

Geologic information

Identification information

Deposit ID 10307374
Record type Site
Current site name Ellis (Boone and Ibeck #1 and #2)

Geographic coordinates

Geographic coordinates: -146.03251, 60.66959 (WGS84)
Relative position This site represents two prospects in a 2.5-mile-long linear area along the bluff above the northwest shore of Sheep Bay. The map site is at the approximate midpoint between the prospects, in the NW1/4 sec. 11, T. 14 S., R. 5 W., of the Copper River Meridian. This site includes both sites C-52 and C-53 of Jansons and others (1984).
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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
Quartz Gangue

Alteration

  • (Local) Contact metamorphism.

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 unit name Sheep Bay
    Chronological age 51
    Stratigraphic age (youngest) Early Eocene

Nearby scientific data

(1) -146.03251, 60.66959

Comments on the geologic information

  • Geologic Description = The prospect consists of chalcopyrite-bearing quartz veins in the Tertiary Orca Group turbidites along the contact of the Sheep Bay pluton (Jansons and others, 1984; Nelson and others, 1985). The Sheep Bay pluton has been radiometrically dated at about 51 Ma (Winkler and Plafker, 1981). Three analyzed samples from Jansons and others' (1984) location C-52 contained 26-115 ppm Cu. Eleven additional samples from the contact area contained 13 ppm to 0.14% Cu and <0.1 ppm to 8.5 ppm silver.
  • Age = the age of mineralization is probably 51 Ma based on the age of the Sheep Bay pluton.
  • Age = Chronological age is for Sheep Bay pluton.

Economic information

Economic information about the deposit and operations

Development status Prospect

Comments on exploration

  • Status = Inactive

Mining district

District name Copper River

Comments on the workings information

  • Workings / Exploration = Area examined by the U.S. Bureau of Mines as part of a mineral evaluation of the Chugach National Forest. Three analyzed samples from location C-52 contained 26-115 ppm Cu. Eleven additional samples from the contact area contained 13 ppm to 0.14% Cu and <0.1 ppm to 8.5 ppm silver (Jansons and others, 1984).

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF CV041

Bibliographic references

  • Deposit

    Winkler, G.R., and Plafker, George, 1981, Geologic map and cross sections of the Cordova and Middleton Island quadrangles, southern Alaska: U.S. Geological Survey Open-File Report 81-1164, 24 p., 1 sheet, scale 1:250,000.

  • 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

    Nelson, S.W., Dumoulin, J. A., and Miller, M.L., 1985, Geologic map of the Chugach National Forest, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-1645-B, scale 1:250,000.

  • Deposit

    Nelson, S.W., Dumoulin, J. A., and Miller, M.L., 1985, Geologic map of the Chugach National Forest, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-1645-B, 16 p., 1 sheet, scale 1:250,000.

Comments on the references

  • Primary Reference = Jansons and others, 1984

General comments

Subject category Comment text
Deposit Model Name = Copper skarn ?
Deposit Other Comments = Chugach Alaska Corporation, Anchorage, Alaska has control of these lands.

Reporter information

Type Date Name Affiliation Comment
Reporter 10-JUN-00 S.W. Nelson U.S. Geological Survey