Rock Creek (Molybdenum)

Prospect, Inactive

Commodities and mineralogy

Main commodities Mo
Ore minerals molybdenite

Geographic location

Quadrangle map, 1:250,000-scale NB
Quadrangle map, 1:63,360-scale C-5
Latitude 62.5996
Longitude -143.3533
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is on the ridge between Rock Creek and Little Jack Creek. It is at an elevation of about 5,300 feet, 1,800 feet southwest of peak 6315, and 4,000 feet southeast of saddle 5310. The site is near the center of the south boundary of section 33, T. 10 N., R. 11 E. of the Copper River Meridian. This is locality 4 of Richter and Schmoll (1973), locality 6 of Richter and others (1975), and National Park Service locality WRST-5 (unpublished data). Cobb and Richter (1980) included this prospect under the name 'Rock Cr.'. It is located to within a few hundred feet.

Geologic setting

Geologic description

Books of molybdenite up to 1.5 inches in diameter occur in a pegmatite dike that cuts alkali gneiss. High grade samples were reported to average about 3 percent molybdenum (Smith, 1939). The pegmatite dike strikes N 20 W, dips 60 SW, ranges from a few inches to 2 feet in thickness and can be traced for 70 feet on the surface. Some molybdenite occurs as flakes, blebs, and veinlets disseminated in finer grained parts of the alkali gneiss (Moffit, 1943, 1954). The gneiss intrudes metavolcanic rocks of the upper Paleozoic, Tetelna Volcanics (Richter and Schmoll, 1973; Richter, 1976).
This deposit was staked in 1936 and explored by open cuts; soon after. Kennecott Copper Corporation drove a 160-foot-long adit under the exposed mineralization in 1937. They did not find molybdenite in the adit and further exploration has been restricted to surface observations and sampling.
Geologic map unit (-143.355447393656, 62.5992325172424)
Mineral deposit model Molybdenum in pegmatite dike
Age of mineralization Early Jurassic or older; K/Ar ages indicate an Early Jurassic or older age for the host intrusive complex (Richter and others, 1975).

Production and reserves

Workings or exploration This deposit was staked in 1936 and explored by open cuts; soon after. Kennecott Copper Corporation drove a 160-foot-long adit under the exposed mineralization in 1937. They did not find molybdenite in the adit and further exploration has been restricted to surface observations and sampling.
Indication of production None

Additional comments

The prospect is in the Wrangell-St. Elias National Preserve.

References