|Quadrangle map, 1:250,000-scale||UN|
|Quadrangle map, 1:63,360-scale||D-2|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||Locality is 1.6 km south of Dutch Harbor airport on Amaknak Island and corresponds to locality 1 of Cobb (1972, MF-446); it is accurate to about 400 m. It also is anomaly no. 27 of Christie (1974).|
Geologic descriptionChristie (1974) reported a color anomaly caused by the oxidation of disseminated pyrite in volcanic breccia of the Unalaska Formation (see Drewes and others, 1961) cut by small swarms of feldspar porphyry andesite and hornblende-biotite porphyry basalt (lamprophyre) dikes. Dikes are oriented 010ø dipping 80ø E. The dikes are weakly mineralized, however small vuggy quartz veins occur adjacent to some dikes. Fracturing in the area varies from moderate to intense. At least one of these quartz veins was gold-bearing on the basis of a report in Drewes and others (1961).
|Geologic map unit||(-166.550192424572, 53.8841361191469)|
|Mineral deposit model||Epithermal gold vein|
|Mineral deposit model number||25|
|Age of mineralization||Miocene or younger|
|Alteration of deposit||Rocks are regionally propylitically altered or metamorphosed to low-grade. Area of locality is highly iron-stained. Christie (1974) reported the alteration assemblage of epidote-chlorite-kaolinite-pyrite accompanied by moderate to intense leaching.|
|Workings or exploration||Brief reconnaissance mapping and sampling reported by Christie (1974); however, in 1992 the entire ridge was being quarried for riprap and fill and being removed for commercial port development (F.H. Wilson, unpublished data, 1992).|
|Indication of production||None|
Additional commentsThis and other undescribed occurrences were apparently reported to Drewes (Drewes and others, 1961) by someone named Eakle on the basis of local reports.
Berg, H.C., and Cobb, E.H., 1967, Metalliferous lode deposits of Alaska: U.S. Geological Survey Bulletin 1246, 254 p.
Christie, J.S., 1974, Aleut-Quintana-Duval 1974 joint venture, final report: Unpublished Quintana Minerals Corporation report, 24 p., 3 appendices, 2 maps.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.)
Cobb, E.H., 1972, Metallic mineral resources map of the Unalaska quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies MF-446, 1 sheet, scale 1: 250,000.
|Reporters||L.P. Niles; S.W. Bie; Damon Bickerstaff, F.H. Wilson|
|Last report date||3/18/1996|