Occurrence, Inactive

Commodities and mineralogy

Main commodities Au; Cu
Gangue minerals chlorite; zeolite

Geographic location

Quadrangle map, 1:250,000-scale AD
Quadrangle map, 1:63,360-scale C-2
Latitude 51.8669
Longitude -176.6269
Nearby scientific data Find additional scientific data near this location
Location and accuracy Topographic knob at east end of dock area at Adak Naval Air Station.

Geologic setting

Geologic description

Silicified volcanic breccia cut by 60-m-wide andesite(?) dike. Coats (1956) mapped knob as a plug, however the bulk of the outcrop along the road is breccia. Interstitial spaces between breccia fragments are locally zeolite(?) filled. Dike has a well developed chilled margin.
Geologic map unit (-176.629372647994, 51.8655224869113)
Age of mineralization Tertiary.
Alteration of deposit Silicification and chloritization of volcanic breccia.

Production and reserves

Workings or exploration A number of samples (93AWs 2a-d) were collected during brief U.S. Geological Survey reconnaissance studies in 1993; all were copper-bearing in the 110-160 ppm Cu range. A few samples of andesite and andesitic volcanic breccia yielded low-level gold in the 2-6 ppb range. Float samples were found of iron-stained andesite(?) that contained 3-5 percent unidentified sulfide minerals.
Indication of production None


MRDS Number A106038
Reporters F.H. Wilson, T.D. Light
Last report date 2/22/1996