Unnamed (east of Sapsuk Lake)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Ag; Cu; Pb; Zn
Other commodities Au; Mo
Ore minerals chalcopyrite; pyrite
Gangue minerals tourmaline

Geographic location

Quadrangle map, 1:250,000-scale PM
Quadrangle map, 1:63,360-scale C-3
Latitude 55.67
Longitude -160.92
Nearby scientific data Find additional scientific data near this location
Location and accuracy The map site of this occurrence is at an elevation of about 1,750 feet, approximately 2.3 miles east-southeast of the east end of Sapsuk Lake (Wilson and others, 1988, locality 87). The site is about 0.25 mile south-southeast of the top of hill 2150. The location is accurate to within 1 mile.

Geologic setting

Geologic description

At this site a 0.5-mile-square color anomaly has resulted from the oxidation of disseminated pyrite in Tertiary andesitic to dacitic volcanic rocks (Wilson and others, 1988; 1995). The main areas of interest are three or more tourmaline-cemented breccia pipes occurring near a 40- by 200-foot plug or dike of quartz porphyry (Trujillo and others, 1982). The largest pipe is approximately 40 feet in diameter and contains dacite porphyry fragments and some disseminated chalcopyrite. Soil, rock, and pan samples contained as much as 0.13 ppm gold, 2.8 ppm silver, 255 ppm copper, 410 ppm lead, 232 ppm zinc, and 21 ppm molybdenum.
Geologic map unit (-160.922019585223, 55.6691730320248)
Mineral deposit model Porphyry Cu, Porphyry Cu-Mo (Cox and Singer; 1986; models 17 and 21a)
Mineral deposit model number 17, 21a
Age of mineralization Tertiary.

Production and reserves

Workings or exploration In 1982 Resource Associates of Alaska examined the occurrence and collected 30 rock samples, 4 pan samples, and 1 soil sample. These assayed as much as 0.13 ppm gold, 2.8 ppm silver, 255 ppm copper, 410 ppm lead, 232 ppm zinc, and 21 ppm molybdenum (Trujillo and others, 1982).
Indication of production None

Additional comments

This site is located within the Alaska Peninsula National Wildlife Refuge.

References

MRDS Number 10308156

References

Trujillo, R.S., Andersen, G.D., MacLeod, T., Hendrick, K., Farnham, S., Peterson, J., 1981. Exploration and evaluation of the Unga-Popof-Korovan Islands portion of lands leased from Aleut Native Corporation: Resource Associates of Alaska report, 70 p., 38 map sheets, various scales. (Report held by the Aleut Corporation, Anchorage, Alaska.)
Reporters S.H. Pilcher
Last report date 1/28/2001