|Quadrangle map, 1:250,000-scale||KC|
|Quadrangle map, 1:63,360-scale||B-5|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This prospect is known only from U.S. Bureau of Mines (1977) claim records. Its approximate location is at an elevation of about 500 feet. It is approximately 0.3 mile inland from the west shore of George Inlet, about 2.7 miles northeast of the north mouth of Herring Bay, and 1.6 miles southwest of the mouth of Beaver Falls Creek. The site is in section 18, T. 75 S., R. 92 E., of the Copper River Meridian. It corresponds to loc. 81 in Elliott and others (1978). The location probably is accurate within about 0.1 mile.|
The country rocks in this part of Revillagigedo Island are marine, pelitic phyllite and schist that are intruded by Cretaceous stocks, sills, and dikes of feldspar-porphyritic granodiorite, and by a stock and probably related plugs of Tertiary gabbro (Berg and others, 1988). The strata and some of the granodiorite were regionally metamorphosed to greenschist grade in Late Cretaceous time. These regionally metamorphosed rocks subsequently were locally contact metamorphosed to hornblende hornfels near the contacts of Cretaceous granodiorite plutons that were emplaced after the regional metamorphism, and then more widely remetamorphosed to hornblende hornfels near the contacts of the Tertiary gabbro. The premetamorphic age range of the pelitic strata is uncertain. Berg and others (1988) assign them a Mesozoic or (Late) Paleozoic age; Brew and Ford (1998) and Crawford and others (2000) assign them to the Gravina belt, of Late Jurassic or Cretaceous age.According to U.S. Bureau of Mines claim records (1977), this prospect, which appears to be in a Tertiary gabbro stock near its contact with pelitic metasedimentary rocks, was staked for Au, Cu, and Ni. No other information about it has been made public.
|Geologic map unit||(-131.485687801082, 55.3606537276655)|
|Indication of production||None|
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.
Brew, D.A., and Ford, A.B., 1998, The Coast Mountains structural zones in southeastern Alaska--descriptions, relations, and lithotectonic significance, in Gray, J.E., and Riehle, J.R., eds., The U.S. Geological Survey in Alaska--Geological studies in Alaska by the U.S. Geological Survey in 1996: U.S. Geological Survey Professional Paper 1595, p. 183-192.
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 in the Ketchikan and Prince Rupert quadrangles, Alaska: U.S. Geological Survey Open-File Report 78-73B, 17 p., 1 sheet, scale 1:250,000.
U.S. Bureau of Mines, 1977, Claim map, Ketchikan quadrangle: U.S. Bureau of Mines Map 120, scale 1:250,000.
|Reporters||H.C. Berg, USGS|
|Last report date||7/3/1999|