Standard Copper Mines Co. (ARDF #CV016) Cu, Zn

Standard Copper Mines Co.

Mine, Inactive

Commodities and mineralogy

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

Geographic location

Quadrangle map, 1:250,000-scale	CV
Quadrangle map, 1:63,360-scale	D-7
Latitude	60.862
Longitude	-146.577
Nearby scientific data	Find additional scientific data near this location
Location and accuracy	This mine is at an elevation of about 1800 feet, about 0.5 mile southeast of Copper Mountain. It is in the NW1/4 sec. 1, T. 12 S., R. 8 W., of the Copper River Meridian. The location of the site is accurate to within 1000 ft. This site is loc. 13 in Cobb (1972: MF-392) and loc. C-77 in Jansons and others (1984).

Geologic setting

Geologic description The country rocks at this mine are mafic volcanic rocks and sedimentary rocks of the Tertiary Orca Group (Nelson and others, 1985). The deposit consists of quartz, calcite, and massive sulfides in shear zones cutting the volcanic rocks. A 6 ft. x 32 ft. lens of massive sulfide was observed by Mihelich and Wells (1957), but most of the sulfide bodies are smaller (Jansons and others, 1984). The sulfide minerals are chalcopyrite, pyrite, pyrrhotite, and sphalerite. Chip samples collected in 1955 (Mihelich and Wells, 1957) contained 0.07 percent to 6.1 percent Cu. Jansons and others (1984) report that three chip samples from the 660-ft.-long adit contained 280 ppm to 0.89 percent Cu, 200 ppm to 0.9 percent Zn, 0.01 parts per million (ppm) to 0.11 ppm Au, and 0.5 ppm to 2.5 ppm Ag. Three grab samples from the adit contained 0.70 percent to 2 percent Cu, 200 ppm to 2 percent Zn, 0.08 ppm to 0.19 ppm Au, and 2.3 ppm to 6.1 ppm Ag. A 2014 grab sample contained 0.175 ppm Au, 5.35 ppm Ag,1.145 percent Cu, and 4.43 percent Zn. A stream sediment sample from below the historical workings contained 0.008 ppm Au, 0.24 ppm Ag, 729 ppm Cu, and 160 ppm Zn (Angel, 2014).
Geologic map unit	(-146.578999846075, 60.8614529538574)
Mineral deposit model	Cyprus massive sulfide (Cox and Singer, 1986; model 24a)
Mineral deposit model number	24a
Age of mineralization	Probably Tertiary based on the age of the host rocks.
Alteration of deposit	Oxidation of copper minerals (Angel, 2014).

Production and reserves

Workings or exploration	Grant and Higgins (1909) report five adits on the steep slopes of Copper Mountain and a tram to an ore bunker on the shore of Landlocked Bay. Only three of the adits could be located in the 1980s (Jansons and others, 1984). Chip samples collected in 1955 (Mihelich and Wells,1957) contained 0.07 percent to 6.1 percent Cu. Jansons and others (1984) report that three chip samples from the 660-ft.-long adit contained 280 ppm to 0.89 percent Cu, 200 ppm to 0.9 percent Zn, 0.01 parts per million (ppm) to 0.11 ppm Au, and 0.5 ppm to 2.5 ppm Ag. Three grab samples from the adit contained 0.70 percent to 2 percent Cu, 200 ppm to 2 percent Zn, 0.08 ppm to 0.19 ppm Au, and 2.3 ppm to 6.1 ppm Ag. Field work including sampling was performed in 2014. A 2014 grab sample contained 0.175 ppm Au, 5.35 ppm Ag,1.145 percent Cu, and 4.43 percent Zn. A stream sediment sample from below the historical workings contained 0.008 ppm Au, 0.24 ppm Ag, 729 ppm Cu, and 160 ppm Zn (Angel, 2014).
Indication of production	Yes
Reserve estimates	Inferred reserves of 4,300 tons at 2.89 percent Cu (Jansons and others, 1984).
Production notes	32,000 lbs. Cu, 518 oz. Ag, and 36 oz. Au were recovered from 1,100 tons of ore. However, it is felt that not all the recovered gold and silver were reported (Mihelich and Wells, 1957).
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	10307357
References Angel, A.K., 2014 Mineral Assessment of Chugach Alaska Lands, Unpublished Report, 21p. (Report held by Chugach Alaska Corporation, Anchorage, Alaska). 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. Cox, D.P., and Singer, D.A., eds., 1986, Mineral deposit models: U.S. Geological Survey Bulletin 1693, 379 p. Crowe, D.E., Nelson, S.W., Brown, P.E., Valley, J.W., and Shanks, W.C., III, 1992, Geology and geochemistry of volcanogenic massive sulfide deposits and related igneous rocks, Prince William Sound region, south-central Alaska: Economic Geology, v. 87, no. 7, p. 1722-1746. Crowe, D.E., Nelson, S.W., Brown, P.E., Valley, J.W., and Shanks, W.C., III, 1993, Geology and geochemistry of volcanogenic massive sulfide deposits and related igneous rocks, Prince William Sound, south-central Alaska--Reply: Economic Geology, v. 88, p. 1285-1288. Grant, U.S., and Higgins, D.F., Jr., 1909, Copper mining and prospecting on Prince William Sound: U.S. Geological Survey Bulletin 379-C, p. 87-96. 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 Mineral Land Assessment 5-84, 218 p., 2 sheets, scale 1:250,000. 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 5320, 21 p. 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. 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.
Reporters	S.W. Nelson, Anchorage, AK; A.K. Angel (Alaska Earth Sciences, Inc.)
Last report date	9/8/2014