|Quadrangle map, 1:250,000-scale||RB|
|Quadrangle map, 1:63,360-scale||A-6|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||Duncan Creek is a southwest-flowing tributary of Poorman Creek and is about 2 miles long. This site is the same as location 30 of Cobb (1972 [MF405]) and location 15 of Eberlein and others (1977). The coordinates are for the approximate center of mining activity on Duncan Creek, in section 21, T. 16 S., R. 17 E., Kateel River Meridian. The location is accurate.|
The bedrock underlying the mouth of Duncan Creek is schist (Mertie, 1936). The gold in Duncan Creek is found near the mouth of the stream; the pay streak follows a previous river channel and does not follow Duncan Creek throughout its length (Mertie, 1936). Near the mouth, 2 feet of the schist must be removed in order to obtain good recovery, but upstream the good pay grades are covered by 43 feet of muck and 2 to 5 feet of subangular gravel. The gravel contains vein quartz, porous quartz breccia, and schist. The gold itself is angular; the largest nugget found weighed 1.21 ounces. Gold is not found farther east than Duncan Creek, and the breccias in the gravel suggest a northeast-trending fault zone near Duncan Creek (Eberlein and others, 1977).Placer gold was discovered on Duncan Creek in 1913, and mining began during the same year. Mining continued intermittently until about 1936.
|Geologic map unit||(-155.512349163339, 64.0876271339217)|
|Mineral deposit model||Placer Au (Cox and Singer, 1986; model 39a).|
|Mineral deposit model number||39a|
|Age of mineralization||Quaternary?|
|Workings or exploration||Several shafts were sunk 40 to 50 feet to bedrock. The creek was mined from 1913 until 1936 (Mertie, 1936; Eberlein and others, 1977).|
|Indication of production||Yes; small|
Additional commentsSee also Little Pup (RB054) and Tenderfoot (RB053).
Brooks, A.H., 1914, Mineral resources of Alaska; report on progress of investigations in 1913: U.S. Geological Survey Bulletin 592, 413 p.
Cobb, E.H., 1972, Metallic mineral resources map of the Ruby quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-405, 1 sheet, scale 1:250,000.
Cobb, E.H., 1977, Placer deposit map of central Alaska: U.S. Geological Survey Open-File Report 77-168-B, 64 p., 1 map, scale 1:1,000,000.
Cobb, E.H., and Chapman, R.M., 1981, Mineral occurrences (other than mineral fuels and construction materials) in the Kantishna River and Ruby quadrangles, Alaska: U.S. Geological Survey Open-File Report 81-170, 94 p.
Eberlein, G.D., Chapman, R.M., Foster, H.L., and Gassaway, J.S., 1977, Map and table describing known metalliferous and selected nonmetalliferous mineral deposits in central Alaska: U.S. Geological Survey Open-File Report 77-168-D, 132 p., 1 sheet, scale 1:1,000,000.
|Reporters||C.E. Cameron (Alaska Division of Geological and Geophysical Surveys)|
|Last report date||3/22/2000|