|Quadrangle map, 1:250,000-scale||SV|
|Quadrangle map, 1:63,360-scale||C-2|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The prospect is located on both sides of the ridge that separates Quartz Bay from Surprise Bay, both of which are in the West Arm of Nuka Bay. This is Cobb's (1972, MF-397) location 25 and MacKevett and Holloway's (1977) location 16. Cobb (1979, OFR 80-87) summarized the relevant references to this prospect under the name Johnson and Degan. This location is accurate within half a mile.|
Geologic descriptionCretaceous Valdez Group graywacke host the mineralization of the Johnson and Degan prospect (Richter, 1970). Generally quartz veins are hosted in the graywacke although conglomerates are found in the area. The veins are white quartz containing few percent sulfides, although some exposures show considerable iron-staining. A single sample through a vein at an elevation of 1,000 feet, on the Surprise Bay side of the ridge, assayed 0.98 ounces of gold and 1.0 ounce of silver per ton (Pilgrim, 1933).
|Geologic map unit||(-150.492098604444, 59.5194199580033)|
|Mineral deposit model||Low-sulfide, Au-quartz vein (Cox and Singer, 1986; model 36a)|
|Mineral deposit model number||36a|
|Age of mineralization||Tertiary; Boden and others (1991) report other veins in the district are about 55 m.y. old.|
|Alteration of deposit||Extensive oxidation staining on surface outcrops. Borden and others (1991) report other veins in the Nuka Bay district show carbonization, sulfidization, sericitization, and silicification of the wall rock adjacent to the veins.|
|Workings or exploration||Surface trails were laid and trenches were dug in the 1930s. A single sample through a vein at 1000 feet elevation on the Surprise Bay side of the ridge, assayed 0.98 ounces of gold and 1.0 ounce of silver per ton (Pilgrim, 1933).|
|Indication of production||None|
Additional commentsThis prospect is within the Kenai Fjords National Park; the area is closed to mineral entry.
Borden, J.C., Goldfarb, R.J., Gent, C.A., Burruss, R.C., and Roushey, B.H., 1992 Geochemistry of lode-gold deposits, Nuka Bay district, southern Kenai Peninsula, in Bradley, D.C., and Dusel-Bacon, Cynthia, eds, Geologic studies in Alaska by the U.S. Geological Survey, 1991: U.S. Geological Survey Bulletin 2041, p. 13-21.
Capps, S.R., 1938, Lode mining in the Nuka Bay district, in Smith, P.S., and other, Mineral industry of Alaska in 1936: U.S. Geological Survey Bulletin 897-A, p. 25-32.
Cobb, E.H., 1972, Metallic mineral resources map of the Seldovia quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-397, 1 sheet, scale 1:250,000.
Cobb, E.H., 1979, Summary of references to mineral occurrences (other than minerals fuels and construction materials) in the Seldovia quadrangle, Alaska: U.S. Geological Survey Open-file Report 80-87, 47 p.
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.
Pilgrim, E.R., 1933, Nuka Bay district, in Stewart, B. D., Making mining investigations and mine inspection in Alaska, biennium ending March 31, 1933: Alaska Territorial Department of Mines Annual Report 1933B, p. 26-51.
|Reporters||Jeff A. Huber (Anchorage)|
|Last report date||2/9/1999|