|Quadrangle map, 1:250,000-scale||KC|
|Quadrangle map, 1:63,360-scale||A-5|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This site represents three occurrences east of Blunt Mountain. The occurrences are in section 2, T. 78 S., R. 93 E., of the Copper River Meridian and section 35, T. 77 S., R. 93 E., of the Copper River Meridian. They range in elevation from about 300 feet to sealevel, and are about 1.3-1.5 miles from the highest point on Blunt Mountain. The coordinates are for the approximate center of the half-square-mile area that contains the occurrences. The site corresponds to loc. 3 in Berg (1972 [I 684]), loc. 143 in Elliott and others (1978), and loc. 29a-c in Karl (1992). The location is accurate within about 0.1 mile.|
The country rocks in the area of this site are recrystallized, Upper Triassic rhyolite, felsic tuff, and limestone (Berg, 1972). The rocks are folded and complexly faulted, and were regionally metamorphosed to greenschist-grade phyllite and semischist in Late Cretaceous time.The occurrences consist of sparsely mineralized, auriferous, sulfide-bearing quartz fissure veins in rhyolite that locally is sheared, sericitized, and impregnated with finely disseminated iron oxide. The veins are up to about 3 feet thick and contain sparse clots of pyrite and other sulfide minerals that, judging from sample assays, include galena, chalcopyrite, and sphalerite. Samples of variously mineralized quartz veins and country rocks contained up to 0.43 oz. Au/ton; 0.91 oz. Ag/ton, 2% Pb, 16.75% Zn, and 1.25% Cu (Berg, 1972, loc. 3; Karl, 1992, loc. 29).
|Geologic map unit||(-131.364682299396, 55.1416595288024)|
|Mineral deposit model||Polymetallic veins (Cox and Singer, 1986; model 22c)|
|Mineral deposit model number||22c|
|Age of mineralization||Probably Late Cretaceous or younger.|
|Alteration of deposit||Local sericitization and iron-oxide alteration.|
|Workings or exploration||Samples of variously mineralized quartz veins and country rocks contained up to 0.43 oz. Au/ton; 0.91 oz. Ag/ton, 2% Pb, 16.75% Zn, and 1.25% Cu (Berg, 1972, loc. 3; Karl, 1992, loc. 29).|
|Indication of production||None|
Berg, H.C., 1972, Geologic map of Annette Island, Alaska: U.S. Geological Survey Miscellaneous Geologic Investigations Map I-684, 8 p., 1 sheet, scale 1:63,360.
|Reporters||H.C. Berg, USGS|
|Last report date||7/6/1999|