Ellamar

Mine, Inactive

Alternative names

Gladhaugh

Commodities and mineralogy

Main commodities Cu; Zn
Other commodities Ag; Au
Ore minerals bornite; chalcopyrite; cubanite; galena; pyrite; pyrrhotite; sphalerite
Gangue minerals calcite; epidote; quartz

Geographic location

Quadrangle map, 1:250,000-scale CV
Quadrangle map, 1:63,360-scale D-8
Latitude 60.8956
Longitude -146.6985
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Ellamar mine is at and below sea level at the Ellamar townsite in Virgin Bay. It is in the SW1/4 sec. 19, T. 11 S., R 8 W., of the Copper River Meridian. The location is accurate to within 100 ft. This prospect is shown as #4 in Cobb (1972: MF-392) and as C-91 in Jansons and others (1984).

Geologic setting

Geologic description

The country rocks at the Ellamar mine are mafic volcanic rocks and sedimentary rocks of the Tertiary Orca Group (Nelson and others, 1985). The deposit is associated with pillow basalt and a diabase dike, and consists of steeply-pitching stratabound lenticular sulfide ore bodies in folded and sheared graywacke and slate (argillite). The ore bodies consist chiefly of masses of pyrite, pyrrhotite, chalcopyrite, cubanite, bornite and sphalerite that form lenses up to 240 ft. wide and 500 ft. long. Gangue minerals are calcite, epidote, and quartz. One 35-foot-thick lens of pyrite overlies and is parallel to lenses of other sulfides (Moffit, 1954).
Three core holes were drilled in 1955-1956. Hole no. 2 cut 10 ft. of ore containing 0.02% Cu, 0.02 oz. Au/ton, and 0.02 oz. Ag/ton; hole no. 3 cut 28 ft. of pyrite which contained 0.5% Cu, 0.085 oz. Au/ton, and 0.75 oz. Ag/ton (Jansons and others, 1984). Jansons and others (1984) sampled the property in the 1980s. A chip sample assayed 5.4% Cu, and 0.10 oz. Au/ton. A grab sample from the dump contained 50 ppm Cu, 0.006 oz. Au/ton, and 0.2 oz. Ag/ton.
Geologic map unit (-146.70052436423, 60.8950633113741)
Mineral deposit model Besshi massive sulfide (Cox and Singer, 1986; model 24b)
Mineral deposit model number 24b
Age of mineralization Early Tertiary based on the age of the host rocks.

Production and reserves

Workings or exploration The Ellamar mine was developed by about 9300 feet of underground workings on eight levels, with connecting stopes between the levels. It was mined from about 1897 to 1920 when the workings flooded. Three core holes were drilled in 1955-1956. Hole no. 2 cut 10 ft. of ore containing 0.02% Cu, 0.02 oz. Au/ton, and 0.02 oz. Ag/ton; hole no. 3 cut 28 ft. of pyrite which contained 0.5% Cu, 0.085 oz. Au/ton, and 0.75 oz. Ag/ton (Jansons and others, 1984). Jansons and others (1984) sampled the property in the 1980s. A chip sample assayed 5.4% Cu, and 0.10 oz. Au/ton. A grab sample from the dump contained 50 ppm Cu, 0.006 oz. Au/ton and 0.2 oz. Ag/ton.
Indication of production Yes; medium
Reserve estimates Indicated reserves: 36,000 tons @ 2% Cu, 0.1 oz. Au/ton, and 0.5 oz. Ag/ton. Inferred reserves: 500,000 tons @ 0.5% Cu, 0.085 oz. Au/ton, and 0.75 oz. Ag/ton (Jansons and others, 1984).
Production notes 15,761,337 lbs. Cu, 51,305 oz. Au, and 191,615 oz. Ag were recovered from 301,835 tons of ore (Jansons and others, 1984).

Additional 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.

References

MRDS Number A010674; D002170

References

Reporters S.W. Nelson, Anchorage, AK
Last report date 6/10/2000