|Quadrangle map, 1:250,000-scale||PM|
|Quadrangle map, 1:63,360-scale||A-3|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The Chance prospect site is located on Unga Island approximately 2,500 feet north of the head of Acheredin Bay (Wilson and others, 1988, locality 31). The map site is near the north end of the boundary between secs. 31 and 32, T. 57 S., R. 75 W., of the Seward Meridian. The location is accurate to within 1,200 feet.|
Geologic descriptionThe Chance prospect consists of several quartz veins in an area of silicified and iron-oxide-rich andesite of the the late Eocene to early Oligocene Popof volcanic rocks (Wilson and others, 1995). The prospect occurs at the intersection of northeast-and northwest-striking faults. Trenching exposed 32 feet of massive quartz. Channel samples contained as much as 0.94 ppm gold, 1.9 ppm silver, 45 ppm copper, 755 ppm lead, 69 ppm zinc, 280 ppm arsenic, and 0.35 ppm mercury. Grab samples contained as much as 0.95 ppm gold, 26 ppm silver, 975 ppm copper, 9,600 ppm lead, 720 ppm zinc, 260 ppm lead, and 3.5 ppm mercury (Peterson and others, 1982).
|Geologic map unit||(-160.717064878746, 55.2051621415604)|
|Mineral deposit model||Epithermal gold veins|
|Age of mineralization||Eocene or younger.|
|Alteration of deposit||The alteration consists of silicification.|
|Workings or exploration||UNC Teton Exploration Drilling Company sampled and trenched this prospect in 1982. Grab samples contained as much as 0.95 ppm gold, 1.9 ppm silver, 79 ppm copper, 995 ppm lead, 720 ppm zinc, 260 ppm arsenic, and 1.2 ppm mercury.|
|Indication of production||None|
Additional commentsThis site is located on land patented by, or interim-conveyed to, the Aleut Corporation.
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.)
Wilson, F.H., Detterman, R.L., Miller, J. W., and Case, J.E., 1995, Geologic map of the Port Moller, Stepovak Bay, and Simeonof Island quadrangles, Alaska: U.S. Geological Survey Miscellaneous Investigation Series Map I-2272, 1 sheet, scale 1:250,000.
|Last report date||1/12/2001|