|Quadrangle map, 1:250,000-scale||UN|
|Quadrangle map, 1:63,360-scale||A-3|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||Three kilometers south of the head of Pumicestone Bay in a lake basin; the lake is locally called Bornite Lake.|
Geologic descriptionQuartz veins up to 60 cm wide cut a silicified roche moutonnee immediately north of lake. Roche moutonnee is pervasively silicified and 500 feet wide by 1,500 feet long (150 x 450 m). Up to 30 percent pyrite occurs in veins and silicified rock. Country rock shown in Drewes and others (1961) as Unalaska Formation, about 2 km from mapped southern margin of Shaler batholith (granodiorite).
|Geologic map unit||(-166.972270502295, 53.4979352166701)|
|Mineral deposit model||Polymetallic vein, epithermal gold vein|
|Mineral deposit model number||22c, 25|
|Age of mineralization||Miocene or younger.|
|Alteration of deposit||Pervasive silicification of country rocks.|
|Workings or exploration||Reported 18th or 19th century mining by Russians. No evidence remains of Russian activity; prospect possibly staked by John and Leon Reinken in 1929. Kennecott-Alaska (Simpson, 1986) collected 23 rock samples; Battle Mountain Exploration Co. (Randolph, 1991) collected pan concentrates and an additional 9 rock samples. None of BMEC rock samples were anomalous in gold; one contained 4.8 ppm silver, 9,085 ppm copper, and 410 ppb mercury. Pan concentrates contained up to 240 ppb gold and 920 ppm copper.|
|Indication of production||None|
Additional commentsReportedly mined during Russian period, Battle Mountain Exploration Co. (Simpson, 1986; erroneously reported as the 1600s). Randolph (1991) gave the prospect a poor potential for economic gold mineralization due to remoteness, ruggedness of the environment, and minimal evidence for economic mineralization.
Drewes, Harold, Fraser, G.D., Snyder, G.L., and Barnett, H.F., Jr., 1961, Geology of Unalaska Island and adjacent insular shelf, Aleutian Islands, Alaska: U.S. Geological Survey Bulletin 1028-S, p. 583-676.
Randolph, D.B., 1991, Unalaska project, 1990 final report: Battle Mountain Exploration Company, Alaska District, 62 p., 5 appendices, 15 plates, various scales. (Report held by the Aleut Corporation, Anchorage, Alaska.)
Simpson, D.F., 1986, Aleutian Islands project, 1985 final report: Kennecott Alaska Exploration Company, 54 p. (Report held by the Aleut Native Corporation, Anchorage, Alaska.)
|Last report date||12/18/1992|