|Quadrangle map, 1:250,000-scale||SM|
|Quadrangle map, 1:63,360-scale||B-6|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This prospect is on the northeastern shoulder of Chineekluk Mountain, about 0.3 mile northeast of the summit. The prospect is at an elevation of about 1,500 feet in the SE1/4 sec. 21, T. 15 N., R. 49 W., of the Seward Meridian. The location is accurate.|
Geologic descriptionThe Chineekluk Mountain cinnabar prospect is in an N65E-trending swarm of altered, mafic dikes that cut hornfels of the Upper Cretaceous Kuskokwim Group on the northeast flank of Chineekluk Mountain (Cady and others, 1955; Decker and others, 1995; M.L. Miller and T.K. Bundtzen, unpublished field data, 1998, 1999). The cinnabar occurs as: 1) isolated grains up to 5 mm in size and as ellipsoidal lenses in altered dikes; 2) in ferricrete breccia zones in hornfels; and 3) in quartz veinlets that intrude both hornfels and the altered mafic dikes. Euhedral, bright-red cinnabar grains are up to 1 cm in diameter. Three cinnabar-bearing zones occur over a distance of about 300 feet on the shoulder of Chineekluk Mountain. Each mineralized zone ranges from 50 to 100 feet long and from 15 to 45 feet thick. The cinnabar-bearing quartz veins are locally controlled by small, northwest-trending, high angle fractures that are oblique to the general northeast trend of the altered mafic dikes. Chip and grab samples of cinnabar mineralization of all three types described were collected (M.L. Miller and T.K. Bundtzen, unpublished analytical data, 1998 and 1999). They contain up to 1.63 percent mercury, 12 parts per billion (ppb) gold, 14.3 parts per million (ppm) silver, 109 ppm antimony, 1,120 ppm lead, 2,310 ppm zinc, 5.5 ppm cadmium, 57.4 ppm tungsten, and 601 ppm strontium. The Chineekluk Mountain mercury deposit may contain specimen quality crystalline cinnabar.
|Geologic map unit||(-158.071958115845, 61.3688711763682)|
|Mineral deposit model||Silica-carbonate mercury? (Cox and Singer, 1986; model 27c).|
|Mineral deposit model number||27c?|
|Age of mineralization||Undated; the nearby Fairview prospect (ARDF SM019) has a 40Ar/39Ar age of 72.6 Ma (Gray, Gent, and others, 1997).|
|Alteration of deposit||Silica-carbonate alteration of mafic dikes.|
|Workings or exploration||M.L. Miller found the Chineekluk prospect during geologic mapping by the U.S. Geological Survey in 1998. The prospect was sketched and sampled the following year (T.K. Bundtzen, unpublished field data, 1999).|
|Indication of production||None|
Cady, W.M., Wallace, R.E., Hoare, J.M., and Webber, E.J., 1955, The central Kuskokwim region, Alaska: U.S. Geological Survey Professional Paper 268, 132 p.
Decker, J.E., Reifenstuhl, R.R., Robinson, M.S., Waythomas, C.F., and Clough, J.G., 1995, Geology of the Sleetmute A-5, A-6, B-5, and B-6 quadrangles southwestern Alaska: Alaska Division of Geological and Geophysical Surveys Professional Report 99, 16 pages, one sheet, scale 1:63,360.
Gray, J.E., Gent, C.A., Snee, L.W., and Wilson, F.H., 1997, Epithermal mercury-antimony and gold-bearing vein lodes of southwest Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral Deposits of Alaska: Economic Geology Monograph 9, p. 287-305.
Wells, J.T., and Ghiorso, M.S., 1988, Rock alteration, mercury transport, and metal deposition at Sulphur Bank, California: Economic Geology, vol. 83, p. 606-618.
White, D. E., and Robinson, C. E., 1962, Sulphur Bank, California, a major hot spring quicksilver deposit, in Engel, A.E.J., James, H.L., and Leonard, B.F., eds., Petrologic studies: A volume in honor of A.F. Buddington: Boulder, Colorado, Geological Society of America p. 397-428.
|Reporters||T.K. Bundtzen (Pacific Rim Geological Consulting, Inc.) and M.L. Miller (U.S. Geological Survey)|
|Last report date||5/9/2003|