Rockybottom Creek

Prospects, Inactive

Commodities and mineralogy

Main commodities Au
Ore minerals gold

Geographic location

Quadrangle map, 1:250,000-scale HU
Quadrangle map, 1:63,360-scale D-1
Latitude 66.9553
Longitude -153.2405
Nearby scientific data Find additional scientific data near this location
Location and accuracy Rockybottom Creek is a northwest-flowing tributary to the Alatna River. It joins the Alatna River about 1.5 miles north-northeast of the junction of the Alatna River and Helpmejack Creek. The prospects are about 4.6 miles east of of the junction of Rockybottom Creek and the Alatna River. The location is accurate within one-half mile.

Geologic setting

Geologic description

Good colors of gold were reported on Rockybottom Creek prior to 1898 (Wyman, 1988). Mendenhall (1902) also reports gold colors and that two men were prospecting on the creek, but did not cite evidence of any significant mining. Kurtak and others (2002) collected several pans of broken-up bedrock that produced a few fine to very fine, flat gold particles. Their placer sample of a thin gravel layer on bedrock has a value of about 0.0003 ounces of gold per cubic yard. In the lower part of Rockybottom Creek, thin gravels cover Cretaceous conglomerate (Patton and Miller, 1966). Upstream the bedrock is graywacke and mudstone. The gold that has been found on the creek appears to be concentrated in fractures and depressions in the bedrock (Kurtak and others, 2002).
Geologic map unit (-153.243227483937, 66.9548089294576)
Mineral deposit model Placer Au (Cox and Singer, 1986; model 39a)
Mineral deposit model number 39a
Age of mineralization Quaternary.

Production and reserves

Workings or exploration Apparently only prospecting.
Indication of production None
Production notes Cobb (1973) refers to reports that indicate the gold on Rockybottom Creek could not be mined profitably.

References

MRDS Number A015593

References

Bottge, R.G., 1988, Maps summarizing land availability for mineral exploration and development in western Alaska, 1986: U.S. Bureau of Mines Open-File Report 14-88, 38 quadrangle overlays.
Heiner, L.E., and Wolff, E.N., eds., 1968, Mineral resources of northern Alaska, Final report, submitted to the NORTH Commission: University of Alaska, Mineral Industry Research Laboratory Report No. 16, 306 p.
Kurtak, J.M., Klieforth, R.F., Clark, J.M., and Maclean, E.A., 2002, Mineral investigations in the Koyukuk mining district, northern Alaska: Final Report: U.S. Bureau of Land Management Technical Report 50, v. 1 and 2, 845 p.
Wyman, J.N., 1988, Journey to the Koyukuk: The photos of J.N. Wyman, 1898-1899: Missoula, Mont., Pictorial Histories Publishing Co., 128 p.
Reporters J.M. Britton (Anchorage)
Last report date 8/1/2002