|Quadrangle map, 1:250,000-scale||SR|
|Quadrangle map, 1:63,360-scale||A-3|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The mine is located about a half-mile east of Powder Point at an elevation between 20 to 480 feet. It is in the NW1/4 section 34, T. 1 S., R. 9 E., of the Seward Meridian. This is location 254 of Tysdal (1978 [MF-880-A]) and location S-19 of Jansons and others (1984). This location is accurate to within 300 feet.|
The Blackbird mine follows a shear zone in graywacke and slate of the Orca Group of early Tertiary age (Nelson and others, 1995). Underground, the shear zone trends northeast and dips nearly vertically. The mineralization occurs in a zone as much as 35 feet wide within the shear zone. Sulfide minerals identified in both the massive and stringer ore are pyrrhotite, chalcopyrite, covellite, and galena (Hoekzema and Sherman, 1983). The mineralization is exposed along the trend for about 300 feet.Samples from one open cut and glory hole contained from 27 ppm to 2.96 percent copper and from 105 ppm to 12.2 percent zinc (Hoekzema and Sherman, 1983).
|Geologic map unit||(-147.895217695985, 60.0529610252554)|
|Mineral deposit model||Besshi massive sulfide (Cox and Singer, 1986; model 24b)|
|Mineral deposit model number||24b|
|Age of mineralization||Tertiary or younger; the mineralization is in rocks of the Orca Group of Tertiary age.|
|Alteration of deposit||There is some silicification of shale and mudstone (Hoekzema and Sherman, 1983).|
|Workings or exploration||There are 1,750 feet of underground workings and several open cuts. Surface improvements consisted of a wharf, ore bunker, a tramway, and a 150-ton-per-day mill (Hoekzema and Sherman, 1983). Samples collected from the open cut and glory hole contained from 27 ppm to 2.96 percent copper and from 105 ppm to 12.2 percent zinc (Hoekzema and Sherman, 1983).|
|Indication of production||None|
|Reserve estimates||The Blackbird mine has a reserve of 201,450 tons of ore containing 3.77 percent copper, 0.7 ounce of silver per ton, and 0.03 ounce of gold per ton. Lead and zinc occur with the reserves but are not quantified (Rogers and Hoyt, 1999).|
|Production notes||Production from the Blackbird mine is 547,118 pounds of copper and 3,980 ounces of silver from 5,100 tons of ore (Hoekzema and Sherman, 1983).|
Bateman, A.N., 1928, Unpublished consultant report to Kennecott Copper Corp., Seattle, Washington 1916-1927; held at the U.S. Bureau of Land Management Alaska State Office, Anchorage, 1 v.
Hoekzema, R.P., and Sherman, G.E., 1983, Mineral investigations in the Chugach National Forest, Alaska (Peninsula study area): U.S. Bureau of Mines in-house report; held at U.S. Bureau of Land Management Alaska State Office, Anchorage, 524 p.
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.
Kurtak, J.M., and Jeske, R.E., 1986, Mineral investigations in the Chugach National Forest, Alaska (Islands area): U.S. Bureau of Mines Open-File Report 54-86, 302 p., 1 sheet, scale 1:63,360.
MacKevett, E.M., Jr., and Holloway, C.D., 1977, Map showing metalliferous and selected non-metalliferous mineral deposits in the eastern part of southern Alaska: U.S. Geological Survey Open-File Report 77-169-A, 99 p., 1 sheet, scale 1:1,000,000.
Moffit, F.H., and Fellows, R.E., 1950, Coper deposits of the Prince William Sound district, Alaska: U.S. Geological Survey Bulletin 963-B, p. 47-80.
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.
Rogers, R., and Hoyt, M., 1999, Mineral prospects on Chugach Alaska Corporation lands: Chugach Alaska Corporation in-house report, 10 p., 1 table, 10 maps.
|Reporters||Jeff A. Huber and Carol S. Huber (Anchorage)|
|Last report date||12/15/2001|