|Quadrangle map, 1:250,000-scale||MM|
|Quadrangle map, 1:63,360-scale||D-1|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This 300-foot-long mineral occurrence (Cobb, 1980 [OFR 80-363]) is on a ridge crest about 2500 feet west-southwest of the top of Chitisia Mountain. The location is at the approximate midpoint of the occurrence and is accurate within 250 feet. The occurrence correponds to number 77 of Bundtzen, Smith, and Tosdal (1976), 58 of Hawley and Associates (1978), and 84 of Bundtzen (1981).|
Geologic descriptionThis occurrence is a stratiform deposit in schistose metarhyolite porphyry in the Upper Devonian to Mississippian Totatlanika Formation (Bundtzen, 1981, p. 82). The outcrop of the deposit is about 300 feet long and about 10 feet wide; it strikes ENE and dips about 30 NW (Hawley and Associates, 1978; fig. 4.1-A(3)). The deposit consists of barite-rich layers 1 to 6 inches thick in silicified(?) schist containing pyrite, galena, and sphalerite. Selected barite-rich samples contain 36-52 percent barium. Pyrite is fairly abundant; galena and sphalerite less so. Some grab samples assayed up to 3.1 percent lead and 0.8 ounce of silver per ton, but most contained 1 percent or less each of lead and zinc (Buntzen, Smith, and Tosdal (1976); Hawley and Associates, 1978; Bundtzen, 1981). The deposit is probably volcanogenic in origin, and formed in Late Devonian or Mississippian time.
|Geologic map unit||(-150.306930562623, 63.963810466265)|
|Mineral deposit model||Distal, barite-rich, kuroko massive sulfide deposit (Cox and Singer, 1986; model 28a).|
|Mineral deposit model number||28a|
|Age of mineralization||The deposit is probably Late Devonian or Mississippian, the depositional age of the Totatlanika metarhyolite hostrock (Bundtzen, 1981).|
|Alteration of deposit||Silicification of Totatlanika schistose metarhyolite.|
|Workings or exploration||The deposit was discovered during reconnaissance geologic mapping of the Kantishna district (Bundtzen, Smith, and Tosdal, 1976). There are no significant workings.|
|Indication of production||None|
Additional commentsThe occurrence exemplifies stratiform, volcanogenic deposits in metarhyolite schist of the Upper Devonian to Mississippian Totatlanika Formation. It is in Denali National Park and Preserve.
Bundtzen, T. K., 1981, Geology and mineral deposits of the Kantishna Hills, Mt. McKinley quadrangle, Alaska: M. S. Thesis, University of Alaska, College, Alaska, 238 p.
Bundtzen, T.K., Smith, T.E., and Tosdal, R.M., 1976, Progress report--Geology and mineral deposits of the Kantishna Hills: Alaska Division of Geological and Geophysical Surveys Open-File Report AOF-98, 80 p., 2 sheets, scale 1:63,360.
Cobb, E.H., 1980, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Mount McKinley quadrangle, Alaska: U. S. Geological Survey Open-File Report 80-363, 150 p.
Cox, D.P., and Singer, D.A., eds., 1986, Mineral deposit models: U.S. Geological Survey Bulletin 1693, 379 p.
|Last report date||5/7/2001|