Pension

Prospect, Inactive

Commodities and mineralogy

Main commodities Ag
Other commodities As; Pb
Ore minerals arsenopyrite; boulangerite; galena; pyrite; scorodite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale MM
Quadrangle map, 1:63,360-scale C-2
Latitude 63.5606
Longitude -150.7817
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 setting

Geologic description

The 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.

Production and reserves

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 comments

The prospect is in Denali National Park and Preserve.

References

MRDS Number A011245

References

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.
Reporters C.C. Hawley
Last report date 1/18/2001