Unnamed (near Renshaw Point)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Ag; Au
Other commodities Cu; Pb; Zn
Ore minerals arsenopyrite; galena; gold; pyrite; sphalerite
Gangue minerals barite; calcite; quartz

Geographic location

Quadrangle map, 1:250,000-scale PM
Quadrangle map, 1:63,360-scale C-2
Latitude 55.622
Longitude -160.38
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at an elevation of about 500 feet on the southwest side of Dorenoi Bay, about 1.25 miles northwest of Renshaw Point (Christie, 1974, color anomaly 74; MacKevett and Holloway, 1977, locality 20; Wilson and others, 1988, locality 20). The location is accurate to within 1,200 feet.

Geologic setting

Geologic description

The area of this occurrence has been mapped by Wilson and others (1995) as Miocene volcanics. According to Butherus and others (1979), the area contains steeply northeast-dipping latite, andesite or basalt flows, and flow breccias overlying sandstone, shale, and conglomerate.
The site is marked by a 10,000- by 5,000-foot color anomaly (Christie, 1974, number 74). Christie describes the deposit as quartz-calcite veins containing minor arsenopyrite, pyrite, sphalerite, and galena. The veins cut the volcanic rocks and strike nearly south. The veins become more numerous towards Renshaw Point and in one 100- by 200-foot area form a pyritic stockwork.
Anderson and others (1980) describe the veins as being as much as 2 feet thick and occurring near prominent shear zones. They also note a 12- to 15-foot thick latite dike that crops out over a distance of 1,000 feet and contains disseminated sphalerite and galena. In many areas the rocks exhibit moderate to strong carbonate alteration, the largest area of which is in andesite or latite and is 100 feet wide and 4,000 feet long.
Rock samples collected by Resource Associates of Alaska (Anderson and others, 1980) from various veins and shear zones assayed as much as 11.5 percent copper, 1.47 percent lead, 11 percent zinc, 0.84 ounce of gold per ton, and 209 ounces of silver per ton. The latite dike with disseminated sulfides assayed as much as 0.39 ounce of gold per ton and 2 percent zinc.
Geologic map unit (-160.382023038185, 55.6211801296057)
Mineral deposit model Epithermal gold veins, Polymetallic veins (Cox and Singer, 1986; model 22c)
Mineral deposit model number 22c
Age of mineralization Miocene or younger.
Alteration of deposit Moderate to strong carbonate alteration is present in most of the volcanic units. This may be a form of propylitic alteration.

Production and reserves

Workings or exploration Christie (1974) reconnaissance-mapped the area and collected eight silt or soil samples. All had detectable gold. Assays ranged from up to 0.03 ppm gold, 4.9 ppm silver, 200 ppm zinc, and low copper and molybdenum values. Rock samples collected by the U.S. Geological Survey studies in the mid-1980s (samples 83ADt 95 and 96) contained as much as 7 ppm silver. Five vein and shear samples collected by Resource Associates of Alaska in 1980 assayed as much as 11.5 percent copper, 1.47 percent lead, 11 percent zinc, 0.84 ounce of gold per ton, and 209 ounces of silver per ton.
Indication of production None

Additional comments

This site is located on land selected by the Aleut Corporation.

References

MRDS Number 10308104

References

Andersen, G.D., Butherus, D.L., Fankhauser, R.E., Pray, J.C., Lindberg, P.A., and Hoffman, B.L., 1980, Exploration and evaluation of lands leased from Aleut Native Corporation 1980: Resource Associates of Alaska Report, 84 p, 16 map sheets, various scales. (Report held by the Aleut Corporation, Anchorage, Alaska.)
Butherus, D. L., Gressitt, E.E., Pray, J., Corner, N.G., Lindberg, P.A., Fankhauser, R.E., 1979, Exploration and evaluation of the Aleut Native Corporation lands: Resource Associates of Alaska Report, 69 p, 90 map sheets, various scales. (Held by the Aleut Corporation, Anchorage)
Christie, J.S., 1974, Aleut-Quintana-Duval 1974 joint venture, final report: Unpublished Quintana Minerals Corporation report, 24 p., 3 appendices, 2 maps. (Report held by the Aleut Corporation, Anchorage, Alaska.)
Freeport Exploration Company, 1985, 1984 report of activities, Canoe Bay joint venture: Freeport Exploration Company, 25 p. (Report held by the Aleut Corporation, Anchorage, Alaska.)
Reporters S.H. Pilcher
Last report date 1/6/2001