|Quadrangle map, 1:250,000-scale||SO|
|Quadrangle map, 1:63,360-scale||C-2|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This prospect is on the east coast of Darby Peninsula, about 3 miles northeast of Carson Creek (Smith and Eakin, 1911). It is apparently near a faulted (?) contact between schist and marble. This is location 24 of Cobb (1972, MF442; 1978, OF 78-181). It is probably located within 0.5 mile.|
Geologic descriptionA short , open-cut exploration trench exposes copper carbonates and some chalcocite disseminated in schist and along joint surfaces (Smith and Eakin, 1911, p. 134-135). Miller and Grybeck (1973) report a 10 feet by 10 feet area of copper staining in quartz-biotite-feldspar schist; a grab sample of the copper-stained schist contained 20,000 ppm Cu, 15 ppm Ag, 0.15 ppm Au, and 200 ppm Mo. Slickensides in schist are well developed and the prospect is a short distance north of massive, light gray limestone (marble). Till and others (1986) identify the marble as lower Paleozoic in age. The metasedimentary rocks are on the east flank of the mid-Cretaceous Darby pluton (Miller and others, 1972; Miller and Bunker, 1976; Berry and others, 1976; Johnson and others, 1979).
|Geologic map unit||(-162.57257133319, 64.509276317885)|
|Mineral deposit model||Disseminations or replacements of metasedimentary rocks and joint fillings by copper-bearing minerals.|
|Age of mineralization||Unknown; emplacement 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) and ampihibolite facies metamorphism of metasedimentary rocks are mid-Cretaceous but the mineralization here could be older or younger than these important regional events.|
|Alteration of deposit||Oxidation; secondary copper minerals are present.|
|Workings or exploration||A small surface trench was excavated prior to 1909.|
|Indication of production||None|
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.
Smith, P.S., and Eakin, H.M., 1911, A geologic reconnaissance in southeastern Seward Peninsula, and the Norton Bay-Nulato region, Alaska: U.S. Geological Survey Bulletin 449, 146 p.
|Reporters||Travis L. Hudson (Applied Geology)|
|Last report date||8/19/1999|