|Quadrangle map, 1:250,000-scale||KC|
|Quadrangle map, 1:63,360-scale||C-3|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This occurrence is on the south shore of Walker Cove about 1.2 miles east of Hut Point. The site is in section 16, T. 71 S., R. 95 E., of the Copper River Meridian. It corresponds to site G-9 in Berg and others (1977, p. 135), and to loc. 25 in Elliott and others (1978). The location is accurate within about 0.1 mile.|
The country rocks in the area of this occurrence consist of paragneiss metamorphic roof pendants, screens, and inclusions in Tertiary or Cretaceous foliated granodiorite and quartz diorite of the Coast Range batholith (Berg and others, 1988). The metamorphic rocks represent marine strata that underwent high-grade regional metamorphism in Cretaceous or Tertiary time. The premetamorphic age of the strata is uncertain, but they probably are mainly Paleozoic and may be as old as Precambrian (Berg and others, 1988, p. 26; Gehrels and others, 1990; Crawford and others, 2000).The occurrence consists of sulfide-bearing paragneiss (Berg and others, 1977, p. 135). The sulfides occur as thin, discontinuous layers of pyrite and sparse chalcopyrite that parallel the foliation of the paragneiss. Anomalous amounts of Cu (280 ppm) and Ag (1.5 ppm) were detected in a grab sample from this locality. A chip sample across a 38-foot section of dark gray paragneiss containing bands of light gray, slightly pyritic paragneiss assayed 1000 ppm Cu and nearly 1 ppm Ag.
|Geologic map unit||(-130.868704915638, 55.7126551969809)|
|Mineral deposit model||Disseminated base-metal sulfides in paragneiss|
|Workings or exploration||Anomalous amounts of Cu (280 ppm) and Ag (1.5 ppm) were detected in a grab sample of pyritic paragneiss from this locality (Berg and others, 1977, p. 135). A chip sample across a 38-foot section of dark gray paragneiss containing bands of light gray, slightly pyritic paragneiss assayed 1000 ppm Cu and nearly 1 ppm Ag.|
|Indication of production||None|
Additional commentsThis site is in Misty Fiords National Monument Wilderness.
Berg, H.C., Elliott, R.L., and Koch, R.D., 1988, Geologic map of the Ketchikan and Prince Rupert quadrangles, southeastern Alaska: U.S. Geological Survey Mineral Investigations Series Map I-1807, 27 p., scale 1:250,000.
Berg, H.C., Elliott, R.L., Smith, J.G., Pittman, T.L., and Kimball, A. L., 1977, Mineral resources of the Granite Fiords Wilderness Study Area, Alaska, with a section on aeromagnetic data by Andrew Griscom: U.S. Geological Survey Bulletin 1403, 151 p.
Crawford, M.L., Crawford, W.A., and Gehrels, G.E., 2000, Terrane assembly and structural relationships in the eastern Prince Rupert quadrangle, British Columbia, in H.H. Stowell and W.C.McClelland, eds., Tectonics of the Coast Mountains, southeastern Alaska and British Columbia: Geological Society of America Special Paper 343, p. 1-21.
Elliott, R.L., Berg, H.C., and Karl, S.M., 1978, map and table describing metalliferous and selected non-metalliferous mineral deposits, Ketchikan and Prince Rupert quadrangles, Alaska: U.S. Geological Survey Open-File Report 78-73-B, 17 p., 1 sheet, scale 1:250,000.
Gehrels, G.E., McClelland, W.C., Samson, S.D., Patchett, P.J., and Jackson, J.L., 1990, Ancient continental margin assemblage in the northern Coast Mountains, southeast Alaska and northwest Canada: Geology, v. 18, no. 3, p. 208-211.
|Reporters||H.C. Berg, USGS|
|Last report date||6/29/1999|