|Quadrangle map, 1:250,000-scale||PM|
|Quadrangle map, 1:63,360-scale||A-2|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This occurrence is approximately located. The map site is at an elevation of about 700 feet, due south of 1,630 foot peak of Apollo Mountain on southeastern Unga Island (MacKevett and Holloway, 1977, locality 13; Wilson and others, 1988, locality 13). The location is accurate to within 2 miles.|
Geologic descriptionThis occurrence consists of quartz veins less than 12 inches thick that crop out discontinuously along stike for 2,500 feet. It also includes a knoblike, 100- by 1,000-foot area of brecciated and silicified andesite containing numerous quartz-filled vugs and limonitic shears. The vein system cuts rocks mapped as Popof volcanic rocks of late Eocene to early Oligocene age (Wilson and others, 1995). Grab samples of the quartz contained as much as 0.23 ppm gold and 10 ppm silver (Wilson and others, 1988). Base metal values are low.
|Geologic map unit||(-160.612062221832, 55.1791656463702)|
|Mineral deposit model||Epithermal gold veins|
|Age of mineralization||Eocene or younger.|
|Workings or exploration||
Some evaluation work may have been done by UNC Teton Exploration Drilling Company for the Aleut Corporation in 1979, 1981, and 1982 (Wilson and others, 1988). Grab samples contained as much as 0.23 ppm gold and 10 ppm silver. Base metal values were low.
Redstar Gold Corp. conducted two phases of exploration in 2016 on their Unga project, which includes the Shumagin (PM064), Apollo (PM079; PM084), Centennial, Orange Mountain (PM067), Zachary Bay (PM054), Amethyst (PM092), and Aquila (PM086) epithermal gold-silver prospects. The Shumagin trend parallels the historically mined Apollo–Sitka vein system (PM079; PM084; PM076), which between 1886 and 1922 produced approximately 150,000 ounces of gold at a grade of approximately 0.292 ounce of gold per ton (Athey and Werdon, 2017).In June 2016, Redstar Gold Corp.’s Phase I surface program included classifying alteration assemblages and conducting other geologic work to identify drill targets. From October through November, Phase II’s drilling program tested the down-dip and along-strike expansion potential of high-grade vein/breccia mineralization within the Shumigan Gold Zone (PM064). A total of 1,505 meters were drilled in 7 holes spaced over ~750 meters of strike length. All drill holes intersected the target structure, which includes multi-generational phreatomagmatic breccias, hydrothermal breccias, and late breccias and veins with colloform-crustiform- to cockade-textured quartz-adularia-carbonate (± rhodochrosite, ± green clay). Select intervals from drill holes 16SH019 and 16SH020 include 0.9 meter at 14.95 grams of gold per tonne and 1.15 meters at 11.3 grams of gold per tonne; release of full assay results is planned for late January 2017 (Athey and Werdon, 2017).
|Indication of production||None|
Additional commentsThis site is located on land patented by, or interim-conveyed to, the Aleut Corporation.
MacKevett, E.M., Jr., and Holloway, C.D., 1977, Map showing metalliferous mineral deposits in the western part of southern Alaska: U.S. Geological Survey Open-File Report 77-169-F, 38 p., 1 sheet, scale 1:1,000,000.
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.)
U.S. Bureau of Mines, 1973, Alaska 1:250,000-scale quadrangle map overlays showing mineral deposit locations, principal minerals, and number and type of claims: U.S. Bureau of Mines Open-File Report 20-73, 95 overlays (updated in 1986, 1987).
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.
|Reporters||S.H. Pilcher; M.B. Werdon (DGGS)|
|Last report date||8/26/2017|