|Quadrangle map, 1:250,000-scale||SM|
|Quadrangle map, 1:63,360-scale||C-7|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The Sue Creek prospect at an elevation of about 2,800 feet on the ridge between the Whitewing Valley and the headwaters of the eastern tributary of Sue Creek. The prospect is about 1.2 mile south-southwest of peak 3461 and about 0.6 mile southwest of the center of sec. 28, T. 19 N., R. 51 W., of the Seward Meridian. The location is accurate.|
The Sue Creek prospect is a large area of hydrothermal alteration and mineralization in the contact zone between border phases of the Cretaceous Horn Mountains pluton and hornfels (Bundtzen and others, 1998). The border phase of the pluton is composed of altered, porphyritic, potassium- feldspar-rich diorite, granite and quartz monzonite. The hornfels is a dark gray to bleached metasiltstone and recrystallized metasandstone. Late aphanitic, felsic dikes cut both the pluton and the hornfels. A northwest-trending high-angle fault crosses the mineralized area and forms part of the southern boundary of the Horn Mountains.
The mineralized area, which covers an area at least 200 feet by 200 feet in size, consists of tourmaline, axinite, quartz, and goethite flooding mainly in hornfels, although some of the goethite flooding occurs in porphyritic granite. The sulfides have been completely altered to a dark brown network of sooty goethite veins, which locally comprise up to 40 percent of the hornfels. Immediately adjacent to the intrusion, a quartz-axinite ferricrete zone about 65 feet thick contains nearly 50 percent brown axinite. The mineralized veins and Fe-boxwork are covered by vegetation to the east and west of the prospect area. Sixteen chip samples taken along about 130 feet of mineralization contained up to 570 parts per million (ppm) zinc, 140 parts per billion (ppb) gold, 788 ppm arsenic, 337 ppm antimony, 102 ppm tungsten, and 33 ppm tin (Bundtzen and others, 1998). Although all samples contained sub-economic amounts of metals, the large extent of the mineralized zone may indicate a larger zone at depth. An unnamed occurrence 400 meters further to the southeast described in Bundtzen and others (1998) may be an extension of the Sue Creek prospect.The occurrence is in an area of where anomalous stream sediment and panned concentrate samples were collected (Gray and others, 1994; Theodorakos and others, 1992). The stream sediment samples contained up to 700 ppb gold, 680 ppb silver, 120 ppm copper, 370 ppm arsenic, 35 ppm antimony, and other elevated metal values. Panned concentrates contained up to 30.0 ppm gold, 15.0 ppm silver, 2,000 ppm lead, 300 ppm antimony, 1,000 ppm bismuth, and 700 ppm tungsten; several samples contained microscopically visible gold, scheelite, and barite.
|Geologic map unit||(-158.546204088035, 61.7009833490476)|
|Mineral deposit model||Silver-polymetallic veins or tin veins (Cox and Singer, 1986; models 20b or 15b).|
|Mineral deposit model number||20b or 15b|
|Age of mineralization||In the contact-metamorphic zone of the Horn Mountain intrusive which was been dated at 68-69 Ma (Bundtzen and others, 1998).|
|Alteration of deposit||Axinite-tourmaline-sulfide greisen.|
|Workings or exploration||Surface sampling was conducted by the Alaska Division of Geological and Geophysical Surveys in 1991 and 1992. A geologic prospect sketch produced during that investigation is provided in Bundtzen and others (1998).|
|Indication of production||None|
Bundtzen, T.K., and Miller, M.L., 1997, Precious metals associated with Late Cretaceous-early Tertiary igneous rocks of southwestern Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral Deposits of Alaska: Economic Geology Monograph 9, p. 242-286.
Bundtzen, T.K., Harris, E.E., Miller, M.L., Layer, P.W., and Laird, G.M., 1998, Geology of the Sleetmute C-7, C-8, D-7, and D-8 quadrangles, Horn Mountains, southwestern Alaska: Alaska Division of Geological and Geophysical Surveys Report of Investigations 98-12, 38 p., one sheet, scale 1:63,360.
Bundtzen, T.K., Miller, M.L., and Hawley, C.C., 2004, Alaska Resource Data File (ARDF) for the Iditarod Quadrangle: U.S. Geological Survey Open File Report 2004-1311.
Cady, W.M., Wallace, R.E., Hoare, J.M., and Webber, E.J., 1955, The central Kuskokwim region, Alaska: U.S. Geological Survey Professional Paper 268, 132 p.
Gray J.E., Theodorakos, P.M., Bradley, L.A., and Bullock, J.H., 1994, Favorable areas for metallic mineral resources in and near the Horn Mountains, Sleetmute quadrangle, southwestern Alaska: U.S. Geological Survey Bulletin 2068, p. 79-90.
Theodorakos, P.M., Borden, J.C., Bullock, J.H. Jr., Gray, J.E., and Hageman, P.L., 1992, Analytical data and sample locality map of stream sediment and heavy mineral concentrate samples collected from the Horn Mountains area, Sleetmute quadrangle, southwest Alaska: U.S. Geological Survey Open-File Report 92-708-A, 36 p., one sheet, scale 1:250,000.
|Reporters||T.K. Bundtzen (Pacific Rim Geological Consulting, Inc.) and M.L. Miller (U.S. Geological Survey)|
|Last report date||5/8/2003|