|Quadrangle map, 1:250,000-scale||MH|
|Quadrangle map, 1:63,360-scale||A-6|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This occurrence is at an elevation of about 4,000 feet in a west-flowing tributary to the West Fork Maclaren River, in the NW1/4SW1/4 section 36, T. 19 S., R. 5 E., Fairbanks Meridian. The site corresponds to locality 11 of Kaufman (1964), locality 18 in figure 4 of Cobb (1979 [OFR 79-238]), and locality 25 in table 2 of Nokleberg and others (1991).|
The rock near this prospect is propylitized metabasalt of the Nikolai Greenstone of Late Triassic age (Nokleberg and others, 1991). Some probably Cretaceous granitic material is exposed at the site.
Copper minerals are found in place and in float at the site. Kaufman (1964, p. 7, occurrence 11) speculated that the source of float minerals is probably a considerable distance upstream.Chalcopyrite occurs in place in stringers in greenstone and intrusive material at the site of the occurrence. Float found in the creek bed at the 4,000-foot elevation consists of banded chalcopyrite-magnetite skarn and banded azurite-malachite.
|Geologic map unit||(-146.715065497068, 63.2237633344364)|
|Mineral deposit model||Basaltic Cu? (Cox and Singer, 1986; model 23?); Cu skarn in float material (Cox and Singer, 1986, model 18b).|
|Mineral deposit model number||23?, 18b|
|Age of mineralization||Uncertain. The banded chalcopyrite-magnetite skarn float is almost certainly derived from the Cretaceous Zackly skarn deposit (MH067), discovered in 1979.|
|Workings or exploration||Bedrock and float mineral specimens were found during geologic mapping (Kaufman, 1964). The source of float almost certainly is the Zackly skarn deposit (MH067).|
|Indication of production||None|
Additional commentsKaufman (1964) noted the mineralized skarn float may have traveled a considerable distance downstream, a conclusion borne out with the discovery of the Zackly prospect (MH067) in 1979 by Resource Associates of Alaska.
Cobb, E.H., 1979, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Mount Hayes quadrangle, Alaska: U.S. Geological Survey Open-File Report 79-238, 140 p.
Kaufman, M.A., 1964, Geology and mineral deposits of the Denali-Maclaren River area, Alaska: Alaska Division of Mines and Minerals Geologic Report 4, 15 p., 1 sheet, scale 1:125,000.
Nokleberg, W.J., Lange, I.M., Roback, R.C., Yeend, Warren, and Silva, S.R., 1991, Map showing locations of metalliferous lode and placer mineral occurrences, mineral deposits, prospects, and mines, Mount Hayes quadrangle, eastern Alaska Range, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-1996-C, 42 p., 1 sheet, scale 1:250,000.
|Reporters||W.T. Ellis (Alaska Earth Science), C.C. Hawley (Hawley Resource Group), and W.J. Nokleberg (USGS)|
|Last report date||8/4/2001|