Cottonwood Creek

Prospect, Inactive

Commodities and mineralogy

Main commodities Au
Other commodities W
Ore minerals gold

Geographic location

Quadrangle map, 1:250,000-scale SK
Quadrangle map, 1:63,360-scale B-4
Latitude 59.29
Longitude -136.21
Nearby scientific data Find additional scientific data near this location
Location and accuracy The location is plotted where Cottonwood Creek flattens and forms an alluvial fan on the northern side of the Tsirku River, about 1 mile northeast of the terminus of the Le Blondeau Glacier. It is shown as location 29 by Cobb (1974 [MF 424]).

Geologic setting

Geologic description

Placer gold was discovered on Cottonwood Creek in 1899. Although encouraging amounts of gold have been found, none has been produced in significant amounts. Gravel resources in the creek channel are limited due to the steep gradient and narrow bedrock canyon. The average gradient is 750 feet per mile. A significant but untested identified resource exists in the alluvial fan at the mouth of the creek which coalesces with the fan at the mouth of Nugget Creek to the east. Abandoned channels, which may host placer gold have been identified in the fan between Cottonwood and Nugget Creeks. Reconnaissance samples contained up to 0.0005 ounces of gold per cubic yard and pan concentrates contained 10-20% magnetite, up to 10% pyrite, and minor amounts of garnet, zircon, and scheelite. (Hoekzema and others, 1986).
The Cottonwood Creek placer lies within a northwest-trending zone of quartz-sulfide veining in sediments and slates in the Skagway B-4 quadrangle described by Wright (1904 [B 225 and B 236]), Eakin (1918 and 1919), and MacKevett and others (1974) and considered to be the source of placer gold in this area.
Geologic map unit (-136.211869954135, 59.2896488733493)
Mineral deposit model Placer in alluvial fans and paleo-channels (Cox and Singer, 1986; model 39a).
Mineral deposit model number 39a
Age of mineralization Quaternary placer.

Production and reserves

Workings or exploration Hoekzema and others (1986) report that placer gold was discovered on Cottonwood Creek in 1899 but gold was never produced in significant amounts. The alluvial fan extending along the northern edge of the Tsirku River from Cottonwood Creek to below Nugget Creek was prospected with encouraging results prior to 1912 and a company was formed to dredge the alluvial gravels. Fifty claims were staked to cover the fan but the ground was abandoned in 1916. Portions of the Cottonwood-Nugget Creek fan were patented in 1934.
Indication of production None
Production notes No significant amount of gold produced.

References

MRDS Number A013086

References

Gilbert and Redman, 1989;
Reporters T.C. Crafford (T. Crafford & Associates, Anchorage)
Last report date 2/4/2001