|Quadrangle map, 1:250,000-scale||MM|
|Quadrangle map, 1:63,360-scale||C-2|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||
The Pension prospect (Cobb, 1980 [OFR 80-363]) is at an elevation of about 3350 feet at the head of the East Fork of Glen Creek. It is probably within 300 feet of the center of the NE1/4 of section 2, T. 16 S., R. 17 W., Fairbanks Meridian. The original prospect site appears to be buried under landslide material.The Pension prospect is included with the Arkansas (MM083) and Glen Ridge No. 1 (MM071) prospects in location 19 of Cobb (1972 [MF 366]) and location 15 of MacKevett and Holloway (1977). The Pension prospect is number 225 of Hawley and Associates (1978), 54 of Bundtzen (1981), and 65 of Thornsberry, McKee, and Salisbury (1984).
Geologic descriptionThe country rock in the area of the Pension prospect is mainly metafelsite of the lower Paleozoic Spruce Creek sequence (Bundtzen, 1981). The schistosity strikes ENE and dips NW (Thornsberry, McKee, and Salisbury (1984, fig. K-2). The deposit consists of quartz-sulfide veins. A quartz vein exposed at the claim discovery site is 5 feet thick, of which about half is massive galena. A selected sample of this vein assayed 150 ounces of silver per ton (Davis, 1923, p. 132). Its strike is not reported. Bundtzen (1981, location 54) described a NW-striking quartz vein that contains arsenopyrite, partly oxidized to scorodite, and boulangerite. A representative sample assayed 2.76 percent lead, 1.15 percent antimony, 0.34 percent arsenic, 1.76 ounces of silver per ton, and 0.16 ounce of gold per ton. The site was covered by landslide debris when examined in 1983 by the U.S. Bureau of Mines. They collected iron-stained quartz nearby that assayed 0.40 ounce of gold per ton (Thornsberry, McKee, and Salisbury, 1984, v. 2, occurrence 65).
|Geologic map unit||(-150.783983607249, 63.5600974276896)|
|Mineral deposit model||Polymetallic veins (Cox and Singer, 1986; model 22c).|
|Mineral deposit model number||22c|
|Age of mineralization||The deposit is assumed to be Eocene (see record MM091).|
|Alteration of deposit||Oxidation of iron and arsenic minerals.|
|Workings or exploration||The deposit was discovered in 1921, and an adit started 25 feet below the discovery vein outcrop (Davis 1923). The workings had sloughed by 1931 (Wells, 1933, p. 374), and by 1933 the original prospect was apparently covered by landslide material.|
|Indication of production||Undetermined|
Additional commentsThe prospect 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.
Cobb, E. H., 1972, Metallic mineral resources map of the Mount McKinley quadrangle, Alaska: U. S. Geological Survey Miscellaneous Field Studies Map MF-366, 1 sheet, scale 1:250,000.
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.
Davis, J. A., 1923, The Kantishna region, Alaska, in Stewart, B. D., Annual Report of the Mine Inspector to the Governor of Alaska, 1922: Alaska Division of Geological and Geophysical Surveys AR-1922.
Hawley, C. C. and Associates, Inc, 1978, Mineral appraisal of lands adjacent to Mt. McKinley National Park, Alaska: U. S. Bureau of Mines Open-File Report 24-78, 275 p. (paged by sections).
MacKevett, E.M., Jr., and Holloway, C.D., 1977, Map showing metalliferous and selected non-metalliferous mineral deposits in the eastern part of southern Alaska: U.S. Geological Survey Open-File Report 77-169-A, 99 p., 1 sheet, scale 1:1,000,000.
Thornsberry, V. V., McKee, C. J., and Salisbury, W. G., eds, 1984, 1983 Mineral Resource Studies: Kantishna Hills and Dunkle Mine Areas, Denali National Park and Preserve, Alaska: U. S. Bureau of Mines Open-File Report 129-84. 3 Volumes: v. 1, Text; v. 2, Appendices; v. 3, Maps. Prepared by Salisbury & Dietz, Inc., Spokane, WA.
|Last report date||1/18/2001|