|Quadrangle map, 1:250,000-scale||MD|
|Quadrangle map, 1:63,360-scale||B-3|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The Bear Pass prospect is at approximately 2,300 feet (700 m) in elevation along a north-trending ridgeline in Section 29, T. 23 S., R. 25 E., of the Kateel River Meridian. Location is known to within 100 feet (30 m).|
Geologic descriptionTwo zones of zinc-bearing, iron oxide gossan occur in areas of 150 feet by 60 feet (46 m by 18 m) and 150 feet by 40 feet (46 m by 12 m) on a prominant ridge top. Mineralization is hosted in a well-developed solution breccia of the Whirlwind Creek Formation of Dutro and Patton (1982); this is in unit 'Dda' of Andrews and Rishel (1982). Host rock is Lower Devonian based on fossil control in 'Dda' unit; age of mineralization is unknown. In both mineralized areas, gossan comprises about 5 percent of available float. A grab sample from an outcrop of solution-breccia mineralization contains 4.38 percent zinc and 100 ppm cadmium (Andrews and Rishel, 1982). Clautice and others (1993) reports grab sample assays of 2.00 percent zinc, 276 ppm arsenic, and 32 ppm molybdenum.
|Geologic map unit||(-154.091331828016, 63.4704106381589)|
|Mineral deposit model||Southeast Missouri Pb-Zn (Cox and Singer, 1986; model 32a) or Mississippi Valley type (Cox and Singer, 1986; model 32b).|
|Mineral deposit model number||32a or 32b|
|Age of mineralization||Host rock is Lower Devonian based on fossil control in 'Dda' unit. The age of mineralization is unknown.|
|Workings or exploration||The Bear Pass prospect was found by WGM Inc. and Patino Ltd. during the late 1970s while conducting base metal exploration on lands selected by Doyon Ltd. In both mineralized areas, gossan comprises about 5 percent of available float. A grab sample from an outcrop of solution breccia mineralization contains 4.38 percent zinc and 100 ppm cadmium. Clautice and others (1993) reports grab sample assays of 2.00 percent zinc, 276 ppm arsenic, and 32 ppm molybdenum.|
|Indication of production||None|
Additional commentsSee Starship (MD043), Spring Ridge (MD047), Beaver (MD048), and Bermuda (MD045) Mississippi Valley Type showings in Medfra quadrangle. The Bear Pass prospect is on land selected or conveyed to Doyon Ltd. For further information, contact Doyon Ltd. at 210 1st Ave., Fairbanks, Alaska, 99701.
Andrews, Tom, and Rishel, John, 1982, Annual Report for 1981, Reef Ridge I-to-XIII Project Areas, Kuskokwim Block, Alaska: Anchorage, Alaska, WGM Inc., Project Report 4, 45 p., 2 sheets, scales 1:63,360 and 1:20,000. (Report held by Doyon, Limited, Fairbanks, Alaska.)
Clautice, K.H., Bowman, N.D., Clough, J.G., Gilbert, W.G., Kline, J.T., Smith, T.E., and Blodgett, R.B., 1993, Land selection unit 8 (Kantishna River, Ruby, and Medfra quadrangles): References, lead isotope, geochemical and major oxide data: Alaska Division of Geological & Geophysical Surveys Public Data File 93-8, 46 p., 1 sheet, scale 1:250,000.
Dutro, J.T. Jr., and Patton,W.W. Jr., 1982, New Paleozoic formations in the northern Kuskokwim Mountains, west-central Alaska: U.S. Geological Survey Bulletin 1529-H, p. H13-H22.
Patton, W.W. Jr., Moll, E.J., Dutro, J.T., Jr., Silberman, M.L., and Chapman, R.M., 1980, Preliminary geologic map of the Medfra quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-811-A, one sheet at 1:250,000 scale.
Schmidt, J.M., 1997, Shale-hosted Zn-Pb-Ag and barite deposits of Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral deposits of Alaska, 1997: Economic Geology Monograph 9, p. 35-65.
|Reporters||Bundtzen, T.K. (Pacific Rim Geological Consulting)|
|Last report date||6/2/1998|