|Quadrangle map, 1:250,000-scale||CH|
|Quadrangle map, 1:63,360-scale||D-4|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The Jim-Montana property lies in the hills immediately south of the North Fork Chandalar River and approximately 8 miles south-southwest of Reds Lake. The reference point is located near the south-center of the Jim-Montana claim group (secs. 28, 33, T. 35 N., R. 6 W., of the Fairbanks Meridian) and is generally the same as loc. 34 in DeYoung (1978). The claims extend approximately a mile west-northwest and east-southeast from the reference point. The Jim-Montana [and IF(?)] property is west of and contiguous with the Mowgli-Sher Khan claim group (CH094), and together they form one large claim block. The location is accurate within a 1-mile radius.|
Geologic descriptionEarly descriptions of this prospect indicated only the presence of disseminated chalcopyrite and sphalerite with minor galena, tennantite, and malachite stains in skarn in the Silurian/Devonian Skajit Limestone (Grybeck, 1977; DeYoung, 1978). Newberry and others (1986) included it in a group of skarn deposits that form a belt northwest of and related to the granitic rocks of the Devonian(?) Horace Mountain plutons. Many of these skarns exhibit both garnet and pyroxene prograde and epidote and actinolite retrograde mineral assemblages, and Newberry and others (1986) stated that the mineralogy, mineralization, and alteration of these skarns categorize them as continental-margin, porphyry-related copper skarns. Newberry and others (1986) classified the prospect, as a Cu-Zn-Pb prospect and Newberry and others (1997) suggest that these Pb-Zn-rich skarns represent distal concentrations surrounding porphyry systems in the Chandalar district. Newberry and others (1997) classify the Jim-Montana deposit as a calcic Zn-Pb skarn and replacement body. The country rock near this prospect is principally Devonian Skajit Limestone (Brosgé and Reiser, 1964).
|Geologic map unit||(-148.912764138391, 67.8196092988372)|
|Mineral deposit model||Zn-Pb skarn deposits? (Cox and Singer, 1986; model 18c?).|
|Mineral deposit model number||18c?|
|Age of mineralization||Devonian(?) based on reported Early Devonian Pb/Pb zircon ages from the associated Baby Creek batholith and Horace Mountain plutons (Dillon and others, 1996).|
|Alteration of deposit||Calc-silicate(?).|
|Workings or exploration||Claims staked in 1972 and 1975.|
|Indication of production||None|
See also: Mowgli-Sher Khan prospect (CH094).Alaska Kardex Nos. 031-58a, 031-60a (Kardex is a card file mining claim information system located at the State of Alaska DNR Public Information Center in Fairbanks).
Arctic Environmental Information and Data Center, 1982, Mineral terranes of Alaska: University of Alaska, Fairbanks, Arctic Environmental Information and Data Center, 7 sheets, scale 1:1,000,000.
Cobb, E.H., and Cruz, E.L., 1983, Summaries of data and lists of references to metallic and selected nonmetallic mineral deposits in the Chandalar quadrangle, Alaska: U.S. Geological Survey Open-File Report 83-278, 91 p.
DeYoung, J.H., Jr., 1978, Mineral resources map of the Chandalar quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-878-B, 2 sheets, scale 1:250,000.
Grybeck, Donald, 1977, Known mineral deposits of the Brooks Range, Alaska: U.S. Geological Survey Open-File Report 77-166C, 45 p., 1 sheet, scale 1:1,000,000.
Maas, K.M., 1987, Maps summarizing land availability for mineral exploration and development in northern Alaska, 1986: U.S. Bureau of Mines Open-File Report 10-87, 33 quadrangle overlays.
Newberry, R.J., Allegro, G.L., Cutler, S.E., Hagen-Levelle, D.D., Adams, D.D., Nicholson, L.C., Weglarz, T.B., Bakke, A.A., Clautice, K.H., Coulter, G.A., Ford, M.J., Myers, G.L., and Szumigala, D.J., 1997, Skarn deposits of Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral Deposits of Alaska: Economic Geology Monograph 9, p. 355-395.
Newberry, R.J., Dillon, J.T., and Adams, D.D., 1986, Regionally metamorphosed calc-silicate-hosted deposits of the Brooks Range, northern Alaska: Economic Geology, v. 81, p. 1728-1752.
Nokleberg, W.J., Bundtzen, T.K., Berg, H.C., Brew, D.A., Grybeck, D.J., Robinson, M.S., Smith, T.E., and Yeend, W., 1987, Significant metalliferous lode deposits and placer districts of Alaska: U.S. Geological Survey Bulletin 1786, 104 p., 2 plates, scale 1:5,000,000.
Nokleberg, W.J., Bundtzen, T.K., Berg, H.C., Brew, D.A., Grybeck, Donald, Robinson, M.S., Smith, T.E., and Yeend, Warren, 1988, Metallogeny and major mineral deposits of Alaska: U.S. Geological Survey Open-File Report 88-73, 97 p., 2 plates, scale 1:5,000,000.
Nokleberg, W.J., Bundtzen, T.K., Dawson, K.M., Eremin, R.A., Goryachev, N.A., Koch, R.D., Ratkin, V.V, Rozenblum, I.S., Shpikerman, V.I., Frolov, Y.F., Gorodinsky, M.E., Melnikov, V.D., Diggles, M.F., Ognyanov, N.V., Petrachenko, E.D., Petrochenko, R.I., Pozdeev, A.I., Ross, K.V., Wood, D.H., Grybeck, D., Khanchuck, A.I., Kovbas, L.I., Nekrasov, I.Y., and Sidorov, A.A., 1996, Significant metalliferous and selected non-metalliferous lode mineral deposits and placer districts, and for metallogenesis of the Russian Far East, Alaska, and the Canadian Cordillera: U.S. Geological Survey Open-File Report 96-513-B, 385 p.; U.S. Geological Survey Open-File Report 96-513-B, 385 p. (CD-ROM format).
Nokleberg, W.J., Bundtzen, T.K., Grybeck, D.J., Koch, R.D., Eremin, R.A., Rozenblum, I. S., Sidorov, A.A., Byalobzhesky, S.G., Sosunov, G.M., Shpikerman, V.I., Gorodinsky, M.E., 1993, Metallogenesis of mainland Alaska and the Russian Northeast: U.S. Geological Survey Open-File Report 93-339, 230 p., 3 sheets, scales 1:4,000.000, 1:10,000,000.
|Reporters||J.M. Britton (Anchorage)|
|Last report date||11/17/1999|