|Quadrangle map, 1:250,000-scale||BN|
|Quadrangle map, 1:63,360-scale||D-5|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||About 5,000 feet of placer gold mine workings are present along the main channel of upper Humbolt Creek. Humbolt Creek is a northeast-flowing tributary to Goodhope River. The placer mine workings begin about 6 miles upstream of the mouth of Ballard Creek, a southeast tributary to Humbolt Creek. This is locality 20 of Cobb (1972; MF 417; 1975; OFR 75-429).|
Geologic descriptionThe headwaters of Humbolt Creek are in an area southeast of the Oonatut Granite Complex (Hudson, 1979; Hudson and Arth, 1983). This area, consists of a Lower Paleozoic metasedimentary assemblage and a polydeformed, metapelitic schist of possible Precambrian age (Till and others, 1986); it is interpreted to be over buried extensions of the Oonatut Granite (Barnes and Hudson, 1977; Hudson, 1979). Cassiterite-rich mineralized zones have not been identified in the headwater bedrock but several high angle fault zones with polymetallic veins (BN048, BN 049, BN050, BN051, BN052) are probably part of tin metallizing systems. The alluvial gravels of Humbolt Creek carry significant gold, for which they have been placer mined, and abundant cassiterite. As early as 1908, gold-bearing concentrate with abundant pyrite and cassiterite was reported (Knopf, 1908). Hydraulic mining and dozer/sluice operations along 5,000 feet of the stream channel took place primarily before WW II (Cobb, 1975). The abundance of cassiterite was a handicap to gold mining; as much as 30 tons of tin concentrate (containing 36,000 pounds of metallic tin) were produced in 1919 (Brooks and Martin, 1921). Most of the cassiterite that was recovered by placer mining was not marketed; oil drums containing cassiterite-rich concentrate (60% tin) were still stored at this location in the 1960s (Sainsbury and others, 1968). The recovered cassiterite included nuggets up to 4 inches across, some show crystal faces, some are brecciated, and some are intergrown with quartz (Sainsbury and others, 1968). Gold and cassiterite can be panned from the surface down through several feet of unmined gravel near the headwater fork of the creek. The gravels here are not mined out (Cobb, 1975, OFR 75-429). The cassiterite-bearing placer deposits are the best indication that significant tin metallization has occurred in the headwaters of the drainage.
|Geologic map unit||(-164.422714814433, 65.8392843912478)|
|Mineral deposit model||Placer Au-PGE (Cox and Singer, 1986; model 39a)|
|Mineral deposit model number||39a|
|Age of mineralization||Quaternary|
|Workings or exploration||About 5,000 feet of placer gold mine workings are present along the main channel of Humbolt Creek. Some test pits and shafts are present in unmined areas.|
|Indication of production||Yes; small|
|Production notes||The abundance of cassiterite was a handicap to gold mining; as much as 30 tons of tin concentrate (containing 36,000 pounds of metallic tin) were produced in 1919 (Brooks and Martin, 1921). Most of the cassiterite that was recovered by placer mining was not marketed; oil drums containing cassiterite-rich concentrate (60% tin) were still stored at this location in the 1960s (Sainsbury and others, 1968).|
|MRDS Number||A012729; W000018|
Barnes, D.F., and Hudson, T.L., 1977, Bouguer gravity map of Seward Peninsula, Alaska: U.S. Geological Survey Open-File Report 77-796-C, 1 sheet, scale 1:1,000,000.
Brooks, A.H., and Martin, G. C., 1921, The Alaska mining industry in 1919: U.S. Geological Survey Bulletin 714-A, p. 59-95.
Cobb, E.H., 1972, Metallic mineral resources map of the Bendeleben quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-417, 1 sheet, scale 1:250,000.
Cobb, E.H., 1975, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Bendeleben quadrangle, Alaska: U.S. Geological Survey Open-File Report 75-429, 123 p.
Hudson, T.L., 1979, Igneous and metamorphic rocks of the Serpentine Hot Springs area, Seward Peninsula, Alaska: U.S. Geological Survey Professional Paper 1079, 27 p.
Hudson, T.L., and Arth, J. G., 1983, Tin granites of Seward Peninsula, Alaska: Geological Society of America Bulletin, v. 94, p. 768-790.
Knopf, Adolph, 1908, The Seward Peninsula tin deposits: U.S. Geological Survey Bulletin 345-E, p. 251-267.
Sainsbury, C.L., Kachadoorian, Reuben, Smith, T.E., and Todd, W.C., 1968, Cassiterite in gold placers at Humboldt Creek, Serpentine-Kougarok area, Seward Peninsula, Alaska: U.S. Geological Survey Circular 565, 7 p.
|Reporters||Travis L. Hudson (Applied Geology)|
|Last report date||3/15/1999|