|Quadrangle map, 1:250,000-scale||BN|
|Quadrangle map, 1:63,360-scale||C-5|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||Black Gulch is a small north tributary to Noxapaga River. Grouse Creek (BN017) is 4,000 feet to the west and Buzzard Creek (BN019) is 1,500 feet to the east of Black Gulch. The location of placer workings on this creek is approximate but the stream is only about 3,000 feet long. This is locality 50 of Cobb (1972; MF 417; 1975; OFR 75-429).|
Geologic descriptionGold was discovered soon after the turn of the century on tributaries to the Noxapaga River including Black Gulch (Collier and others, 1908) and mining took place here after WW II (Hopkins, 1963; Cobb, 1975, OFR 75-429). Frozen, stratified peat and silt (muck), 20 to 30 feet-thick, commonly overlies a few feet of auriferous gravel on schist bedrock in the general area (Hopkins, 1963, Figure 8, p. 94). Muck locally contains bones of extinct Pleistocene mammals. Although tundra cover of bedrock is extensive in the area (Till and others, 1986), Hopkins (1963) indicates that quartz-calcite veins are common in schist bedrock of the gold- producing tributaries to the Noxapaga River.
|Geologic map unit||(-164.204674248958, 65.5212776132279)|
|Mineral deposit model||Placer Au-PGE (Cox and Singer, 1986; model 39a).|
|Mineral deposit model number||39a|
|Age of mineralization||Quaternary; an early radiocarbon age on shallow parts of the frozen and stratified peat and silt of Black Gulch was 8,800 +/- 200 years (Hopkins, 1963, Figure 8). The thin gold-bearing gravels on bedrock here were many feet stratigraphically below the radiocarbon dated deposits.|
|Workings or exploration||Surface open-cut placer mining, including dozer and sluice operations, took place on this creek.|
|Indication of production||Yes; small|
|Production notes||Although gold was discovered here at least by 1906 (Brooks, 1907), significant mining seems to have taken place just before WW II (Smith, 1939 (B 910A); 1939 (B917A); 1941) and after (Hopkins (1963).|
Smith, P.S., 1939, Mineral industry of Alaska in 1937: U.S. Geological Survey Bulletin 910-A, p. 1-113.
Smith, P.S., 1939, Mineral industry of Alaska in 1938: U.S. Geological Survey Bulletin 917-A, p. 1-113.
|Reporters||Travis L. Hudson (Applied Geology)|
|Last report date||3/15/1999|