|Quadrangle map, 1:250,000-scale||SO|
|Quadrangle map, 1:63,360-scale||C-1|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This occurrence is at about 175 feet elevation on a north tributary to the Kwiniuk River. The mouth of this tributary is 1.6 miles downstream from the confluence of Kwiniuk River and a major south tributary that is unnamed on the curent USGS topographic map, but is identified as Corral Creek by West (1953, Plate 1). This is locality 134 of Cobb (1972, MF 445; 1978, OF 78-181).|
Geologic descriptionA heavy-mineral concentrate from stream gravels at this locality contained sphene, hornblende, allanite, apatite, hematite, garnet; traces of spinel, scheelite, powellite, magnetite, epidote, rutile, pyrite, and chalcopyrite. This sample (approximate concentration ratio of 230:1) contained 0.017% equivalent uranium (sample 2961, West, 1953). The stream drains the contact between the Darby pluton (Miller and others, 1972; Miller and Bunker, 1976; Johnson and others, 1979) and Paleozoic marble and related metasedimentary rocks (Till and others, 1986). The slightly uraniferous granodiorite and granite of the Darby pluton is mid-Cretaceous; K/Ar ages for the Darby pluton are 88.3 +/- 1.5 and 92.8 +/- 2.6 Ma (Berry and others, 1976). The possible sources of heavy minerals in the stream gravels include skarns, veins, and disseminations at or near the contact of the Darby pluton and metasedimentary rocks. The widespread elevated Nb values in stream sediments (Miller and Grybeck, 1973) and in heavy -mineral concentrates (West, 1953) of the Clear Creek-Vulcan Creek area to the north may indicate specific mineralized zones or disseminations in late, felsic phases of the Darby pluton (Miller and Grybeck, 1973).
|Geologic map unit||(-162.358583364864, 64.7282891674323)|
|Mineral deposit model||Skarns, veins, or disseminations at or near the contact of the Darby pluton and metasedimentary rocks; disseminations in late, felsic phases of the Darby pluton.|
|Age of mineralization||The lode source of the heavy minerals in the stream gravels is probably mid-Cretaceous, the age of the Darby pluton; K/Ar ages for the Darby pluton are 88.3 +/- 1.5 and 92.8 +/- 2.6 Ma (Berry and others, 1976).|
|Workings or exploration||There are no known workings; exploration in the region may have included reconnaissance stream sediment sampling and radiometric surveys.|
|Indication of production||None|
|MRDS Number||A012572; D002607|
Berry, A.L., Dalrymple, G.B., Lamphere, M.A., and Von Essen, J.C., and others, 1976, Summary of miscellaneous potassium-argon age measurements, U.S. Geological Survey, Menlo Park, California, for the years 1972-1974: U.S. Geological Survey Circular 727, 13 p.
Cobb, E.H., 1972, Metallic mineral resources map of the Solomon quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-445, 1 sheet, scale 1:250,000.
Cobb, E.H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Solomon quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-181, 185 p.
Johnson, B.R., Miller, T.P., and Karl, Susan, 1979, Uranium-thorium investigations of the Darby pluton, Seward Peninsula, Alaska: U.S. Geological Survey Circular 804-B, p. B68-B70.
Miller, T.P., and Bunker, C.M., 1976, A reconnaissance study of the uranium and thorium contents of plutonic rocks of the southeastern Seward Peninsula, Alaska: U.S. Geological Survey Journal of Research, v. 4, p. 367-377.
Miller, T.P., and Grybeck, D.J., 1973, Geochemical survey of the eastern Solomon and southeastern Bendeleben quadrangles, Seward Peninsula, Alaska: U.S. Geological Survey Open-File Report 73-189, 115 p.
Miller, T.P., Grybeck, D.J., Elliott, R.L., and Hudson, T.L., 1972, Preliminary geologic map of the southeastern Bendeleben and eastern Solomon quadrangles, eastern Seward Peninsula, Alaska: U.S. Geological Survey Open-File Report 72-256, 11 p., 1 sheet, scale 1:250,000.
Till, A.B., Dumoulin, J.A., Gamble, B. ., Kaufman, D.S., and Carroll, P.I., 1986, Preliminary geologic map and fossil data, Soloman, Bendeleben, and southern Kotzebue quadrangles, Seward Peninsula, Alaska: U.S. Geological Survey Open-File Report 86-276, 10 p., 3 plates, scale 1:250,000.
|Reporters||Travis L. Hudson (Applied Geology)|
|Last report date||8/19/1999|