|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 occurrence is on the shoreline of outer Sylburn Harbor, about 1.8 miles north-northeast of Driest Point. The site is in section 8, T. 77 S., R. 92 E., of the Copper River Meridian. It corresponds to loc. 14 in Berg (1972 [I 684]), loc. 133 in Elliott and others (1978), and loc. 14a-c in Karl (1992). The location is accurate within 0.1 mile.|
Geologic descriptionThe country rock at this site is locally sheared and sericitized Silurian trondhjemite that was regionally metamorphosed to greenschist grade in Late Cretaceous time (Berg, 1972). The occurrence consists of galena in a thin, discontinuous, calcite-quartz fissure vein in a subhorizontal shear zone up to 20 feet thick and several hundred feet long. A grab sample of the sulfide-bearing vein assayed 1.38 oz. Au/ton and 0.42 oz. Ag/ton.
|Geologic map unit||(-131.587680881529, 55.2006549411775)|
|Mineral deposit model||Polymetallic veins? (Cox and Singer, 1986; model 22c)|
|Mineral deposit model number||22c|
|Age of mineralization||The fissure vein probably is Late Cretaceous or younger in age.|
|Alteration of deposit||Local sericitization of trondhjemite.|
|Workings or exploration||A grab sample of the sulfide-bearing vein assayed 1.38 oz. Au/ton and 0.42 oz. Ag/ton (Berg, 1972).|
|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|