|Quadrangle map, 1:250,000-scale||MG|
|Quadrangle map, 1:63,360-scale||A-1|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This unnamed occurrence is located in a northeast-facing slope near a saddle between two northeast-flowing tributaries of Post River. It is at an elevation of 5,180 feet (1,579 m) in the SW1/4 sec. 23, T. 23 N., R. 23 W., of the Seward Meridian. The occurrence corresponds to map number 33 in Bundtzen, Harris, and Gilbert (1997) The reporter investigated the site in 1988; at station nos. 88BT150-151.|
This unnamed occurrence consists of significant amounts of cross-cutting quartz-sulfide stringers and stockwork in dacite-andesite flows and tuffs of the Eocene Terra Cotta Volcanic Field (Bundtzen, Harris, and Gilbert, 1997).Individual veins range from 2 to 10 centimeters thick and contain 3 to 8 percent pyrite and a bladed Sb mineral - probably stibnite. An elongate, SE to NW-trending, 45 meter wide by 110 meter long area of hydrothermal alteration contains intense silicification of andesite and strong ferricrete gossan. About 10 percent of the area is a sulfide gossan. A northeast- trending fault breccia cuts off the sulfidized zone on the southeast; the northeast limit of the mineralized area is obscured by talus and a snow field (present in 1988). Two grab samples of sulfide-quartz stockwork contain up to 4,200 ppm arsenic, 360 ppb gold, 150 ppm antimony, and 2,100 ppm zinc (Bundtzen, Harris, and Gilbert, 1997).
|Geologic map unit||(-153.448230495879, 62.0623861254738)|
|Mineral deposit model||Creede epithermal vein? (Cox and Singer, 1986; model 25b?).|
|Mineral deposit model number||25b?|
|Age of mineralization||Unknown; hosted in Eocene Terra Cotta Volcanic Field (Solie and others, 1991).|
|Alteration of deposit||Strong silicification and ferricrete gossan.|
|Workings or exploration||The reporter found the mineralization during geologic mapping for the Alaska Division of Geological and Geophysical Surveys in 1988 (Bundtzen, Harris, and Gilbert, 1997). Two grab samples of sulfide-quartz stockwork contain up to 4,200 ppm arsenic, 360 ppb gold, 150 ppm antimony, and 2,100 ppm zinc.|
|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.
|Reporters||T.K. Bundtzen (Pacific Rim Geological Consulting)|
|Last report date||12/9/1998|