|Quadrangle map, 1:250,000-scale||PA|
|Quadrangle map, 1:63,360-scale||D-1|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This prospect is on the Corn group of claims (PA029) but is mineralogically distinct. The prospect is centered at an elevation of about 180 feet, 2,000 feet from the mouth of a small stream informally called 'Skate Creek', and about 0.8 mile southwest of triangulation station 'Low', which is at the prominent point at the northeast end of the peninsula north of Saginaw Bay. The Skate Creek prospect is about 0.6 mile west-northwest of the center of section 2, T. 58 S., R. 72 E.|
This prospect is one of a group of similar deposits (PA021 to PA031) that are scattered along the south shore of Saginaw Bay, on the peninsula north of Saginaw Bay, and on the Keku Islands. They occur in a heterogeneous section of unmetamorphosed volcanic, carbonate, and clastic rocks that vary in age from Silurian to Triassic (Muffler, 1967). The mineralization generally consists of veins, veinlets, and irregular pods that contain base metals and barite (Still and others, 2002). There are no plutonic rocks in the immediate vicinity; however, the sedimentary rocks are cut by scattered gabbro dikes. The origin of the deposits is uncertain although most appear to be epigenetic. Various origins have been proposed including that they are remobilized massive-sulfide deposits, that they are related to a buried intrusive, or that they are Mississippi-Valley-type deposits.
This prospect is along a creek informally named 'Skate Creek' that is covered by the Corn block of claims described separately (PA029). It is unclear how much of the work described at the Corn prospect was along Skate Creek but the mineralization along Slate Creek is distinctly different from that elsewhere on the Corn claims. The rocks along Skate Creek consist of felsic flows, tuffs, and volcanic breccia that are part of the Keku Volcanics of Triassic age (Muffler, 1967).The volcanic breccia along Skate Creek is commonly silicified and pyritized with the formation of considerable calcite (Still and others, 2002). Pyrite, sphalerite, galena, and chalcopyrite occur in the matrix of the breccia and higher grade potions of the breccia appear to be associated with faults. The breccia is also cut by barite veins with pyrite, sphalerite, chalcopyrite, and galena. Still and others (2002) collected 28 samples along Skate Creek. The best zinc values were 2.2 percent zinc across 2 feet of mineralization, and 4,434 parts per million (ppm) across 16 feet. The best barium values were 2.7 percent across 2 feet and 3.9 percent across 16 feet. The highest copper value was 4,33 ppm, the highest lead value was 1,356 ppm; the highest gold value was 63 parts per billion; and the highest silver value was 32.8 ppm.
|Geologic map unit||(-134.041322137085, 56.8726035114143)|
|Mineral deposit model||Zn-Pb-Ba breccia fillings and veins.|
|Age of mineralization||Younger than the Triassic host rocks.|
|Alteration of deposit||The felsic volcanic breccia near the sulfide-bearing veins and breccia fillings is commonly silicified and pyritized.|
|Workings or exploration||There is little information on exploration specifically along Skate Creek. However, the prospect is covered by the Corn group of claims (PA029) that were explored by several companies in the 1970s and 1980s. Some of their work was probably along Skate Creek.|
|Indication of production||None|
Hedderly-Smith, D.A., 1993, Report of the 1992 field season, Sealaska minerals reconnaissance report: Unpublished report, p. 92-114. (Report held by the Sealaska Corporation, Juneau, Alaska.)
Muffler, L.J.P., 1967, Stratigraphy of the Keku Islets and neighboring parts of Kuiu and Kupreanof Islands, southeastern Alaska: U.S. Geological Survey Bulletin 1241-C, p. C1-C52.
Still, J.C., Bittenbender, P.E., Bean, K.W., and Gensler, E.G., 2002 Mineral assessment of the Stikine area, central Southeast Alaska: U.S. Bureau of Land Management Technical Report 51, 560 p.
|Reporters||Donald J. Grybeck (U.S. Geological Survey)|
|Last report date||2-Jan-05|