Andronica occurrence, Alaska Peninsula District, Aleutians East Borough, Alaska, USA
Latitude & Longitude (WGS84): | 55° 19' 50'' North , 160° 4' 44'' West |
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Latitude & Longitude (decimal): | 55.33083,-160.07889 |
The site is located on land selected by the Aleut Corporation.
Location: This occurrence is at an elevation of about 1,100 feet on western Adronica Island. The map site is at the midpoint of the boundary between R70 and 71W, T56S, Seward Meridian, (Christie 1974, color anomaly 84; MacKevett and Holloway, 1977, locality 18; Wilson and others, 1988, locality 18). The location site is accurate.
Geology: This occurrence is in rocks mapped as Popof volcanic rocks of late Eocene to early Oligocene age (Wilson and others, 1995). It is marked by a color anomaly measuring about 6,000 feet by 1,000 feet (Christie, 1974). The anomaly is marked by pyritic-argillic alteration. The rocks include flat-lying flows, tuffs, and volcaniclastic sedimentary rocks (Ellis and Apel, 1989). Moderate pervasive pyritic alteration occurs in several areas. Rock, soil, and pan-concentrate samples outlined 2-square-mile area containing anomalous mercury values. Cinnabar and gold were noted in several pan-concentrate samples. Gold values in the 100-to 500-ppb range are common in the stream-sediment and soil samples. No rock samples contained anomalous gold values. Major north-to north-northwest-trending zones of shearing and faulting may in part, control the mineralization.
Workings: Battle Mountain Exploration Company explored this area from 1988 to 1989. They mapped, sampled, and prospected along six grid lines, and collected a total of 357 rock, soil, and pan-concentrate samples. They also ran magnetometer and VLF-EM surveys.
Age: Eocene or younger.
Alteration: Pyritic-argillic alteration has been noted.
Commodities (Major) - Au, Hg
Development Status: None
Commodity List
This is a list of exploitable or exploited mineral commodities recorded at this locality.Mineral List
3 valid minerals.
Regional Geology
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
Eocene - Tertiary 33.9 - 66 Ma ID: 1709335 | Meshik Volcanics and similar rock units Age: Paleogene (33.9 - 66 Ma) Stratigraphic Name: Meshik Volcanics Description: Popof volcanic rocks, only in Shumagin Islands = Meshik Lithology: Igneous Reference: Wilson, F.H., Hults, C.P., Mull, C.G, and Karl, S.M. (compilers). Geologic map of Alaska. doi: 10.3133/sim3340. U.S. Geological Survey Scientific Investigations Map 3340, pamphlet 196. [21] |
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