|Quadrangle map, 1:250,000-scale||MG|
|Quadrangle map, 1:63,360-scale||B-2|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This unnamed occurrence is located in a steep canyon of the west fork of Sheep Creek, on its east bank, at an elevation of 2,450 feet (746 m) in the SW1/4 sec. 23, T. 27 N., R. 25 W., of the Seward Meridian. The reporter visited the site in 1998 at station no. 98BT448.|
Geologic descriptionThis occurrence is a highly sulfidized, alteration zone in a rhyodacite unit of the Paleocene to Eocene, Sheep Creek Volcanic Field (Bundtzen, Harris, and Gilbert, 1997). A very distinct, ferricrete gossan occurs in a cliff wall on the east side of Sheep Creek; the incompetent, mineralized walls have partially caved into the creek channel. The mineralization consists of disseminated to massive pyrite-quartz veins and stockworks up to 2 meters in width. Strike lengths were not determined. The mineralized area averages about 25 percent pyrite. Grab samples of massive pyrite-quartz veins contained an average 15.5 percent iron, 255 ppm copper, and 0.45 ppm silver (T.K. Bundtzen and G.M. Laird, written communication, 1998).
|Geologic map unit||(-153.870223454612, 62.4123883088346)|
|Mineral deposit model||Polymetallic veins (Cox and Singer, 1986; model 22c).|
|Mineral deposit model number||22c|
|Age of mineralization||Mineralization is undated.|
|Alteration of deposit||Strong silicification and sericite zones.|
|Workings or exploration||The reporter investigated the site in 1981. Grab samples that contained massive pyrite-quartz stockwork veins yielded an average 255 ppm copper, 15.5 percent iron, and 0.45 ppm silver (T.K. Bundtzen and G.M. Laird, written communication, 1998).|
|Indication of production||None|
Bundtzen, T.K., Harris, E.E., and Gilbert, W.G., 1997, Geologic Map of the eastern McGrath quadrangle, Alaska: Alaska Division of Geological and Geophysical Surveys Report of Investigations 97-14, 34 p., 1 sheet, scale 1:125,000.
Bundtzen, T.K., Kline, J.T., and Clough, J.G., 1982, Preliminary geologiy of the McGrath B-2 quadrangle, Alaska: Alaska Division of Geological and Geophysical Surveys Open-File report 149, 22 p., 1 sheet, scale 1:40,000.
|Reporters||T.K. Bundtzen (Pacific Rim Geological Consulting)|
|Last report date||12/4/1998|