|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||The Clough occurrence is in a saddle that separates two northwest-trending ridge lines, about 2.0 kilometers west of the north end of Smith Lake. It is at an elevation of about 4,500 feet in the SW1/4 sec. 20, T. 26 N., R. 24 W., of the Seward Meridian. (The occurrence as shown in Bundtzen, Harris, and Gilbert (1997; map no. 10) is mislocated.)|
The Clough occurrence is a small but rich deposit in skarn adjacent to an altered, east-west-trending felsic (?) dike. The skarn is in argillaceous limestone of the mid-Silurian Terra Cotta Mountains Sandstone, a unit of the Dillinger sub-terrane (Bundtzen, Harris, and Gilbert, 1997).
The principle sulfides are massive pyrite and sphalerite in veins up to 8 centimeters thick; they and a trace of chalcopyrite occur in an epidote-quartz skarn. One grab sample of mineralization contained 13.0 percent zinc, 0.11 percent lead, 0.50 percent copper, 26 grams of silver per tonne, and 300 parts per million cobalt. (Bundtzen, Kline, and Clough, 1982; Bundtzen, Harris, and Gilbert, 1997).In 2008, this prospect was one of several in a block of claims that covered more than 70 square miles, known collectively as the BMP project (International Tower Hill Mines, Ltd., 2008).
|Geologic map unit||(-153.773422088787, 62.325187616245)|
|Mineral deposit model||Low temperature lead-zinc skarn (Cox and Singer, 1986; model 18c).|
|Mineral deposit model number||18c|
|Alteration of deposit||None.|
|Workings or exploration||The Clough occurrence was found by Jim Clough of Alaska Division of Geological and Geophysical Surveys during a geologic mapping program in 1981 (Bundtzen, Kline, and Clough, 1982). As of 2008, the prospect was within a large block of claims called the BMP project by International Tower Hill MIne, Ltd. (2008).|
|Indication of production||None|
Additional commentsSimilar to Rat Fork-Headwall (MG059) and Rat Fork-Base (MG058) prospects.
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 geology 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.
International Tower Hills Mines, Ltd., 2008, BMP: http://www.ithmines.com/s/BMP.asp (as of April 30, 2008).
|Reporters||T.K. Bundtzen (Pacific Rim Geological Consulting); D.J. Grybeck (Port Ludlow, WA)|
|Last report date||6/5/2008|