|Quadrangle map, 1:250,000-scale||CR|
|Quadrangle map, 1:63,360-scale||A-1|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This prospect is near Moss Point on the south side of Port Johnson. It is about 0.5 mile east-southeast of the center of section 7, T. 78 S., R. 89 E. Pyritic zones in phyllite extend from near Moss Point south to an elevation of about 400 feet. The location is accurate.|
Geologic descriptionMaas and others (1991) found an old adit at this site, but apparently there is no earlier record of it. Near Moss Point, an iron-stained pyrite-bearing zone about 12 feet wide occurs in phyllite. A chip sample across the zone contained 0.01 ounce of gold per ton, 30 parts per million (ppm) copper, and 100 ppm zinc. Another pyrite-bearing zone about 20 feet wide in phyllite on the beach contained 5 to 44 parts per billion (ppb) gold. Several more pyrite-bearing zones occur in the phyllite to the south up to an elevation of about 400 feet. The best sample from those zones assayed 165 ppb gold. A 20-foot adit south of Moss Point at an elevation of about 365 feet was driven on another such zone. Samples along 7 to 19 feet of the adit contained 6 to 144 ppb gold. Hedderly-Smith (1999 [Inventory]) suggests that the deposit is of submarine volcanogenic origin. The rocks in the area are part of the Wales Group of Late Proterozoic and Cambrian age (Eberlein and others, 1983; Brew, 1996).
|Geologic map unit||(-132.048120322045, 55.1194845043133)|
|Mineral deposit model||Pyrite-bearing volcanogenic deposit in phyllite.|
|Age of mineralization||Syngenetic volcanogenic deposit in phyllite of Late Proterozoic or Cambrian age.|
|Workings or exploration||The only working is an old 20-foot adit. The prospect has been sampled by government and industry geologists.|
|Indication of production||None|
Brew, D.A., 1996, Geologic map of the Craig, Dixon Entrance, and parts of the Ketchikan and Prince Rupert quadrangles, southeastern Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-2319, 53 p., 1 sheet, scale 1:250,000.
Eberlein, G.D., Churkin, Michael, Jr., Carter, Claire, Berg, H.C., and Ovenshine, A. T., 1983, Geology of the Craig quadrangle, Alaska: U.S. Geological Survey Open-File Report 83-91, 52 p.
Hedderly-Smith, D.A., 1993, Report of the 1992 field season-Sealaska minerals reconnaissance project: Sealaska Corporation, 60 p. (Unpublished report held by the Sealaska Corporation, Juneau, Alaska.)
Hedderly-Smith, D.A., 1999, Inventory of metallic mineral prospects, showings and anomalies on Sealaska lands, 1988 through 1998: Sealaska Corporation, Juneau, Alaska, 217 p. (internal report held by Sealaska Corporation, Juneau, Alaska).
Maas, K.M., Bittenbender, P E., and Still, J.C., 1995, Mineral investigations in the Ketchikan mining district, southeastern Alaska: U.S. Bureau of Mines Open-File Report 11-95, 606 p.
|Reporters||D.J. Grybeck (Applied Geology)|
|Last report date||5/1/2004|