|Quadrangle map, 1:250,000-scale||TY|
|Quadrangle map, 1:63,360-scale||D-7|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The location of this occurrence is approximated from Spurr (1900, p. 110-112, June 24 campsite; U.S. Bureau of Mines, 1998, MAS # 0020840014; MacKevett and Holloway, 1977, p. 76, locality 4; and Cobb, 1972, MF 385, locality 5) in Section 25, T. 22 N., R. 17 W. One of the reporters (Millholland) was unable to located the occurrence in the field using the localites cited above.|
Geologic descriptionFolded volcanic rocks are cut by granitic dioritic and syenitic dikes. Rock along contacts between dikes and volcanics are decomposed and iron stained (Spurr, 1900, p. 110-112). Narrow quartz veins up to several inches wide are rich in pyrite, chalcopyrite and galena. Other zones near, but not at, contacts generally follow stratification, are similarly mineralized and contain gold and silver. Upstream, black slate is cut by granitic dikes; quartz veins carry pyrite, chalcopyrite and galena. Assay of sample with pyrite and chalcopyrite assayed 0.05 oz/ton gold and 0.15 oz/ton silver. Assay of a quartz vein sample returned 0.1 oz/ton gold and 0.25 oz/ton silver (Spurr, 1900, p. 259). The basic reference was published in 1900; no more recent information is available.
|Geologic map unit||(-152.302226910138, 61.9594283952634)|
|Mineral deposit model||Hydrothermal/contact metamorphic?, polymetallic vein?, disseminated? (MacKevett and Holloway, 1977).|
|Workings or exploration||Prospecting with rock sample assayed.|
|Indication of production||None|
Additional commentsThe basic reference was published in 1900; no more recent information is available.
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 Tyonek quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-385, 1 sheet, scale 1:250,000.
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.
Spurr, J.E., 1900, A reconnaissance in southwestern Alaska in 1898 in Walcott, C.D., Twentieth Annual report of the United States Geological Survey, 1898-1899: Part VII - Explorations in Alaska in 1898, p. 31-264.
U.S. Bureau of Mines, 1998, Minerals Availability System/Minerals Industry Location System (MAS/MILS), Talkeetna quadrangle: Worldwide Web URL http://imcg.wr.usgs.gov/data.html.
|Reporters||Madelyn A. Millholland (Anchorage), James Riehle (USGS)|
|Last report date||6/1/1998|