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Threeman (Standard Copper)

Past Producer in Alaska, United States with commodities Copper, Zinc, Silver, Gold, Cobalt
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Geologic information

Identification information

Deposit ID 10307359
Record type Site
Current site name Threeman (Standard Copper)

Geographic coordinates

Geographic coordinates: -146.53954, 60.85459 (WGS84)
Relative position The mine is at an elevation of about 300 feet above the north shore of inner Landlocked Bay, and about 0.25 mile north-northeast of VABM Dick. It is in the S1/2 sec. 6, T. 12 S., R. 7 W., of the Copper River Meridian. The site location is accurate to within 1000 ft. The location corresponds to site C-73 in Jansons and others (1984) and to #14 in Cobb (1972: MF-392).
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Copper Primary
Zinc Primary
Silver Secondary
Gold Secondary
Cobalt Secondary

Materials information

Materials Type of material
Chalcopyrite Ore
Cubanite Ore
Galena Ore
Pyrite Ore
Pyrrhotite Ore
Sphalerite Ore

Mineral occurrence model information

Model code 90
USGS model code 24a
Deposit model name Massive sulfide, Cyprus
Mark3 model number 11

Nearby scientific data

(1) -146.53954, 60.85459
ListMap

Comments on the geologic information

  • Geologic Description = The deposit at this mine is in mafic volcanic and sedimentary rocks of the Tertiary Orca Group (Nelson and others, 1985). It consists of two sulfide lenses up to about 6 ft wide and over 300 ft. long in pillow basalt and sedimentary rocks (Mihelich and Wells, 1957). Sulfide minerals include chalcopyrite, cubanite, galena, pyrite, pyrrhotite, and sphalerite. Chip and grab samples contained 53 ppm to 5.25% Cu, 40 ppm to 2.85% Zn, <0.02 ppm to 0.10 ppm Au, <1 ppm to 22 ppm Ag, and 5 to 700 ppm Co (Jansons and others, 1984). Sixteen chip samples taken in 1955 contained 0.3 % to 8.6% Cu, 0.05% to 0.64% Zn, trace to 0.07 oz.Au/ton and trace to 0.78 oz. Ag/ton (Mihelich and Wells, 1957).
  • Age = Probably Tertiary baased on the age of the host rocks.

Economic information

Economic information about the deposit and operations

Development status Past Producer

Comments on exploration

  • Status = Inactive

Mining district

District name Copper River

Comments on the production information

  • Production Notes = 1,159,660 lbs. Cu, 101 oz. Au, 5,308 oz. Ag from 6,196.5 tons ore (Mihelich and Wells, 1957).

Comments on the reserve resource information

  • Reserves = Inferred reserves of 1,902,000 tons @ 1.05% Cu (Sainsbury, 1953).

Comments on the workings information

  • Workings / Exploration = There are several thousand feet of workings on three levels. Three adits were caved when visited by this reporter in 1974 and 1986 (also see Sainsbury, 1993). Chip and grab samples contained 53 ppm to 5.25% Cu, 40 ppm to 2.85% Zn, <0.02 ppm to 0.10 ppm Au, <1 ppm to 22 ppm Ag, and 5 to 700 ppm Co (Jansons and others, 1984). Sixteen chip samples taken in 1955 contained 0.3 % to 8.6% Cu, 0.05% to 0.64% Zn, trace to 0.07 oz.Au/ton and trace to 0.78 oz. Ag/ton (Mihelich and Wells, 1957).

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF CV020

Bibliographic references

  • Deposit

    Mihelich, M., and Wells, R.R., 1957, Copper mines and prospects adjacent to Landlocked Bay, Prince William Sound, Alaska: U.S. Bureau of Mines Report of Investigations RI 5320, 21 p.

  • 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

    Crowe, D.E., Nelson, S.W., Brown, P.E., Shanks III, W.C., and Valley, J.W., 1992, Geology and geochemistry of volcanogenic massive sulfide deposits and related igneous rocks, Prince William Sound, south-central Alaska: Economic Geology, v. 87, p. 1722-1746.

  • Deposit

    Crowe, D.E., Nelson, S.W., Brown, P.E., Shanks III, W.C., and Valley, J.W., 1993, Geology and geochemistry of volcanogenic massive sulfide deposits and related igneous rocks, Prince William Sound, south-central Alaska-A reply: Economic Geology, v. 88, p. 1285-1288.

  • Deposit

    Sainsbury, C.L., 1993, Geology and geochemistry of volcanogenic massive sulfide deposits and related igneous rocks, Prince William Sound, south-central Alaska, A discussion: Economic Geology, v. 88, p. 1284-1285.

  • Deposit

    Cobb, E.H., 1972, Metallic mineral resources map of the Cordova quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-392, 1 sheet, 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 = Mihelich and Wells, 1957

General comments

Subject category Comment text
Deposit Model Name = Cyprus massive sulfide (Cox and Singer, 1986; model 24a)
Deposit Other Comments = Nelson and others (1985) interpret the country rocks as accreted ocean crust. Crowe and others (1992; 1993) and Sainsbury (1993) discuss the genesis of the volcanogenic massive sulfide deposits in this area.. 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