|Quadrangle map, 1:250,000-scale||SI|
|Quadrangle map, 1:63,360-scale||D-1|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The Copper Chief prospect is at sea level about 2.5 miles north of the mouth of Pack Creek. The prospect is 0.7 mile northeast of the southwest corner of sec. 30, T. 45 S., R. 69 E. It is location 65 of Cobb (1972, 1978) and MAS no. 0021140077 (U.S. Bureau of Land Management, 2002). The location is accurate within 0.2 mile.|
Geologic descriptionThe rocks in the vicinity of the Copper Chief prospect are part of the Triassic Hyd Formation which consists of volcanic rocks, limestone, slate, chert, and conglomerate (Lathram and others, 1965). The Copper Chief prospect has been known since before 1906. Wright (1906) described it as quartz stringers with chalcopyrite, pyrite, and possibly gold in a zone 20 feet wide in quartz schist. The zone is exposed for 200 feet. The deposit was explored by a 60-foot shaft and a 20-foot crosscut prior to 1906. Race and Rose (1967) mostly cite Wright's information but indicate that the ore contains 1 to 1.7 percent copper.
|Geologic map unit||(-134.303054600622, 57.9397637320187)|
|Mineral deposit model||Quartz veinlets with copper in schist.|
|Age of mineralization||Triassic or younger based on the age of the host rock.|
|Workings or exploration||The only workings are a 60-foot shaft and a 20-foot crosscut driven before 1906.|
|Indication of production||None|
Additional commentsThe prospect is now within the Wilderness of the Admiralty Island National Monument and is closed to mineral exploration and development.
Berg, H.C., and Cobb, E.H., 1967, Metalliferous lode deposits of Alaska: U.S. Geological Survey Bulletin 1246, 254 p.
Cobb, E.H., 1972, Metallic mineral resources map of the Sitka quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-467, scale 1:250,000.
Cobb, E.H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Sitka quadrangle: U.S. Geological Survey Open-File Report 78-450, 124 p.
Lathram, E.H., Loney, R.A., Berg, H.C., and Pomeroy, J.S., 1960, Progress map of the geology of Admiralty Island, Alaska: U.S. Geological Survey Miscellaneous Investigations Map I-323, 1 sheet, scale 1:250,000.
Lathram, E.H., Pomeroy, J.S., Berg, H.C., and Loney, R.A., 1965, Reconnaissance geology of Admiralty Island, Alaska: U.S. Geological Survey Bulletin 1181-R, p. R1-R48.
Race, W.H., and Rose, A.W., 1967, Geochemical and geological investigations of Admiralty Island, southeastern Alaska: Alaska Division of Geological and Geophysical Surveys, Geochemical Report 8, 45 p.
U.S. Bureau of Land Management, 2002, Alaska mineral locations database report (Sitka quadrangle), July 2, 2002, 205 p. [http://imcg.wr.usgs.gov/dem.html]
|Reporters||Donald Grybeck (U.S. Geological Survey)|
|Last report date||5/5/2005|