See 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.
Location: 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).
Geology: Two 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.
Workings: 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.
Age: Host rock is Lower Devonian based on fossil control in 'Dda' unit. The age of mineralization is unknown.
Reserves: None.

Commodities (Major) - Zn; (Minor) - As, Cd, Mo
Development Status: No
Deposit Model: Southeast Missouri Pb-Zn (Cox and Singer, 1986; model no. 32a) or Mississippi V

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Commodity List

This is a list of exploitable or exploited mineral commodities recorded at this locality.

ⓘ Arsenic

ⓘ Cadmium

ⓘ Molybdenum

Mineral List

ⓘ 'Limonite'

Detailed Mineral List:

ⓘ 'Limonite'

References:

(2008) Alaska Resource Data File (ARDF) Open-File Report 2008-1225. US Geological Survey

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Unclassified
ⓘ	'Limonite'	-

List of minerals for each chemical element

Other Databases

Link to USGS - Alaska:	MD044

Other Regions, Features and Areas containing this locality

North AmericaContinent

North America PlateTectonic Plate

Farewell-McGrath DomainDomain
Farewell TerranePassive Margin

This page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.

References

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 and Geophysical Surveys, 42 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, 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.

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Bear Pass Prospect, Yukon-Koyukuk Census Area, Alaska, USAiRegional Level TypesBear Pass ProspectProspect Yukon-Koyukuk Census AreaCensus Area AlaskaState USACountry function showexplain() { $("#locexplain").toggle(); if (typeof movemap === "function") movemap(); }