Altair

Prospect, Inactive

Commodities and mineralogy

Main commodities Ag; Au
Other commodities As; Cu; Hg; Pb; Zn
Ore minerals chalcopyrite; galena; gold; pyrite; sphalerite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale PM
Quadrangle map, 1:63,360-scale A-2
Latitude 55.188
Longitude -160.656
Nearby scientific data Find additional scientific data near this location
Location and accuracy The map site of the Altair prospect is at an elevation of 400 feet, about 750 feet west-northwest of the center of sec. 3, T. 58 S., R. 75 W., Seward Meridian. The location is accurate to within 1,200 feet.

Geologic setting

Geologic description

The Altair deposit is a northeast-striking vein system that crops out approximately 500 feet southeast of, and parallel to, the Ankle Creek vein (PM090) (Peterson and others, 1982, figure 11). The system is approximately 25 feet wide in the discovery area. Individual quartz veins are as much as 18 inches wide (Trujillo and others, 1981). The sulfide minerals include pyrite, and, based on assays probably chalcopyrite, galena, and sphalerite. The system has been traced for approximately 1,400 feet along strike, and at its northeast end it intersects the Amethyst vein (PM092). The host rocks are propylitized and argillized andesite flows of the late Eocene to early Oligocene Popof volcanic rocks (Wilson and others, 1995).
At the intersection of the Ankle Creek and Amethyst veins, the vein systems form an ore shoot 150 to 200 feet long. The shoot is 30 feet wide and consists of a loose network of braided and parallel quartz veins 0.5 to 8 inches in width. Comb structures and banding are common. One drill hole and trench have penetrated the shoot. Gold is present mostly in the hanging wall of the shoot. The best assay of trench samples of the shoot was 5.14 ppm gold and 6.17 ppm silver over 9 feet (Trujillo and others, 1981). The drill hole intersected 16.5 feet assaying (core plus sludge) up to 8.3 ppm gold, 24.5 ppm silver, 1,120 ppm copper, 2,300 ppm lead, 870 ppm zinc, 240 ppm arsenic, and 0.11 ppm mercury (Anderson and others, 1980). At the southwest end of the shoot, two holes cut 35- to 40-foot wide vein zones. No gold was detected. It is assumed that good precious metal values occur only at changes in strike and at structural intersections (Trujillo and others, 1981).
Geologic map unit (-160.658067907837, 55.1871635039312)
Mineral deposit model Epithermal gold vein
Age of mineralization Eocene or younger.
Alteration of deposit Alteration in the host rock grades from strongly propylitic to argillic, mainly in zones 20 to 60 feet wide adjacent to the vein systems.

Production and reserves

Workings or exploration During the period 1980 to 1981 Resource Associates of Alaska mapped and sampled the prospect, conducted geophysical surveys, dug two trenches, and drilled three core holes (Trujillo and others, 1981). The best trench sample contained 5.14 ppm gold and 6.17 ppm silver over 9 feet. A drill hole intersected 16.5 feet of an ore shoot assaying as much as 8.3 ppm gold and 24.5 ppm silver.
Indication of production None

Additional comments

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

References

MRDS Number 10308155

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.)
Peterson, R.J., Lemmers, J., Handverger, P., Gallagher, J., Pilcher, R., East, J., Macleod, T., Bartels. E., 1982, Geology and precious metals potential Unga, Popof, and Korovin Islands, Shumagin Group, Aleutian Chain, Alaska: UNC Teton Exploration Drilling Company report, 127 p., 5 map sheets, various scales. (Report held by the Aleut Corporation, Anchorage, Alaska.)
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 2/2/2001