Ober Creek

Prospect, Inactive

Commodities and mineralogy

Main commodities Au
Other commodities U
Ore minerals gold; monazite
Gangue minerals epidote; fluorite; zircon

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale C-4
Latitude 63.7194
Longitude -145.7739
Nearby scientific data Find additional scientific data near this location
Location and accuracy This placer prospect is located at the forks of upper Ober Creek about 4 miles northeast of Donnelly Station. The workings are at an elevation of 2,500 feet in the NE1/4NE1/4 section 10, T. 14 S., R. 10 E, Fairbanks Meridian. This prospect is described by Moffitt (1942) and corresponds to locality 2 in Cobb (1979 [OFR 79-238]) and locality N1 in table 3 of Nokelberg and others (1991). The location is accurate within a one-half mile.

Geologic setting

Geologic description

Small amounts of gold occur in thin, frozen alluvial stream gravels at this locality (Moffit, 1942). The gravels are derived from extensive glacial deposits and metasedimentary schists (Nokleberg and others, 1991). Placer concentrate collected by Wedow and others (1954) contained as much as 0.011 percent equivalent uranium (eU), as well as monazite, zircon, fluorite, and epidote.
Geologic map unit (-145.776190931226, 63.7189978156193)
Mineral deposit model Placer Au (Cox and Singer, 1986; model 39a).
Mineral deposit model number 39a
Age of mineralization Holocene.

Production and reserves

Workings or exploration In 1942, the site was marked by cabins, pits, and abandoned equipment, suggesting considerable exploration and development (Moffit, 1942). Placer concentrate collected by Wedow and others (1954) averaged about 0.006 percent equivalent uranium (maximum of 0.011 percent).
Indication of production None

Additional comments

Wedow and others (1954) judged the deposit to be mainly of mineralogic interest because the gold content and radioactivity level were too low to be of economic significance.
The prospect is mislocated on plate 7 in U.S. Geological Survey Bulletin 989-D (Moffit, 1954); it is shown as approximately 4 miles farther north than is described in other publications.


MRDS Number A011824


Reporters W.T. Ellis (Alaska Earth Science), C.C. Hawley (Hawley Resource Group), and W.J. Nokleberg (USGS)
Last report date 8/9/2002