Stemwinder

Occurrence, Inactive

Commodities and mineralogy

Main commodities Au
Other commodities As; Hg
Ore minerals gold; pyrite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale PM
Quadrangle map, 1:63,360-scale B-2
Latitude 55.328
Longitude -160.575
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is on Unga Island approximately 4,000 feet east of Coal Harbor. The map site is at an elevation of 200 feet, 0.25 mile east-southeast of the top of hill 358, in the SW1/4 of sec. 14, T. 56 S., R. 74 W., Seward Meridian.The location is accurate to within 1,200 feet.

Geologic setting

Geologic description

This site consists of a 200-foot long, northwest-trending quartz-pyrite stockwork. The stockwork comprises quartz veins 0.5 to 6 inches thick that contain pyrite laminations and clots. The host rock is argillically altered andesite mapped as Eocene to Oligocene Popof volcanic rocks (Wilson and others, 1995). Of 19 rock samples, two contained gold (0.04 and 0.22 ppm) and three contained mercury (0.15 to 1.55 ppm). Pan samples contained as much as 1.2 ppm gold (Ellis, 1988).
Geologic map unit (-160.577021533657, 55.3271758875103)
Mineral deposit model Epithermal gold veins
Age of mineralization Eocene or younger.
Alteration of deposit The host rock exhibits argillic alteration.

Production and reserves

Workings or exploration In 1988 Battle Mountain Exploration Company examined this site and collected 19 rock, 32 soil, and 12 pan samples. Only two rock samples contained anomalous gold values (0.04 and 0.22 ppm).
Indication of production None

Additional comments

This occurrence is located on land patented by, or interim-conveyed to, the Aleut Corporation.

References

References

Ellis, W.T., 1988, Unga/Alaska Peninsula project, 1988 report: Battle Mountain Exploration Company report, 64 p. (Report held by the Aleut Corporation, Anchorage, Alaska.)
Reporters S.H. Pilcher
Last report date 2/4/2001