Andronica Occurrence, Alaska Peninsula District, Aleutians East Borough, Alaska, USA

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 R. 70 and 71 W, T. 56 S., 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

References:
Christie, J.S., 1974, Aleut-Quintana-Duval 1974 joint venture, final report: Unpublished Quintana Minerals Corporation report, 24 p., 3 appendices, 2 maps. (Report held by the Aleut Corporation, Anchorage, Alaska.) Ellis, W.T., and Apel, R.A., 1989, Unga/Alaska Peninsula 1989 final report: Battle Mountain Exploration Company report, 41 p., 28 map sheets at various scales. (Report held by the Aleut Corporation, Anchorage, Alaska.) 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. 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. Wilson, F.H., White, W.H., and DuBois, G.D., 1988, Brief descriptions of mines, prospects, and mineral occurrences in the Port Moller and Stepovak Bay quadrangles, Alaska Peninsula: U.S. Geological Survey Open-File Report 88-666, 128 p., 1 plate, scale 1:250,000.