Nugget Creek

Mine, Undetermined

Alternative names

Nugget Bench High Channel

Commodities and mineralogy

Main commodities Au
Other commodities Sn; W
Ore minerals arsenopyrite; cassiterite; gold; ilmenite; magnetite; pyrite; scheelite
Gangue minerals garnet; quartz; zircon

Geographic location

Quadrangle map, 1:250,000-scale TL
Quadrangle map, 1:63,360-scale C-2
Latitude 62.52
Longitude -150.93
Nearby scientific data Find additional scientific data near this location
Location and accuracy C.C. Hawley and Associates, Inc. (1978, Fig. 4.2-B(3)) show placer ground from the confluence of Nugget Creek with Cache Creek to about 1.5 miles upstream through Sections 9, 15, and 16 in T. 29 N., R. 9 W., of the Seward Meridian. The Nugget Bench High Channel Deposit is shown on Fig. 4.2-B(3) about one mile upstream from the confluence. Coordinates given in this record are for the Nugget Bench High Channel.

Geologic setting

Geologic description

Both Quaternary glaciofluvial deposits and Tertiary conglomeratic (white quartz-breccia, Clark and Hawley, 1968) units have been mined on Nugget Creek. The area is underlain by the Sterling Formation (Tps), the upper member of the Tertiary Kenai Group, and Mesozoic argillite (KJs) (Reed and Nelson, 1980). Quaternary auriferous stream gravels from 6 to 8 feet deep and bench gravels 1 to 6 feet deep above the Sterling Formation have been mined (Clark and Hawley, 1968, p. 11). The Nugget Bench High Channel cuts down through the Tertiary formations into the underlying Mesozoic argillite (KJs) exposing the Tertiary conglomerate/white quartz breccia deposits. The channel slopes away from present drainage direction and bedrock drains have been cut to Nugget Creek where it has been mined for 1000 feet along a northeast-southwest trend across Nugget Creek (C.C. Hawley and Associates, Inc., 1978). The channel can be projected magnetically for 400 feet beyond the mined section (C.C. Hawley and Associates, Inc., 1978). The gold fineness ranges from 860 to 864 and averages 861 (Clark and Hawley, 1968).
C.C. Hawley and Associates, Inc. (1978) report that as much as 30,000 ounces of placer gold may have been produced from the Nugget Bench deposits. In late 1907 grades were about $3 per bedrock foot.
Hawley and Clark (1973, p. A6) note that the highest grade lode deposits in Yentna district are located at the Nugget Creek, the Colby (TL037), Bird (TL040) prospects.
Glaciofluvial deposits similar to Nugget Creek can be found on Windy Creek (TL027) and Bird Creek (TL040). Older Tertiary conglomeratic (white quartz breccia, Clark and Hawley, 1968) units probably represent southwest flowing drainages similar to those in Thunder (TL032, 058), Falls (TL030), Dollar (TL031) and Willow (TL042) Creeks. Gold was reconcentrated from these older Tertiary channels into the modern Cache Creek drainage (C.C. Hawley and Associates, Inc., 1978).
Also see Cache Creek (TL029).
Geologic map unit (-150.932285812644, 62.5194788694377)
Mineral deposit model Placer Au-PGE (Cox and Singer, 1986; model 39a).
Mineral deposit model number 39a
Age of mineralization Pleistocene and Tertiary (Clark and Hawley, 1968).
Alteration of deposit Argillic alteration is locally associated with the white quartz conglomerate (Clark and Hawley, 1968).

Production and reserves

Workings or exploration Nugget Bench High Channel has been mined by conventional placer methods for 1000 feet along a northeast-southwest trend across Nugget Creek.
Indication of production Yes
Production notes C.C. Hawley and Associates, Inc. (1978) report that as much as 30,000 ounces of gold may have been produced from these deposits. In late 1907 grades were about $3 per bedrock foot.

Additional comments

Both Quaternary glaciofluvial deposits and Tertiary conglomeratic units have been mined on Nugget Creek. Glaciofluvial deposits similar to Nugget Creek can be found on Windy Creek (TL027) and Bird Creek (TL040). Older Tertiary conglomeratic units probably represent southwest flowing drainages similar to those in Thunder (TL032, 058), Falls (TL030), Dollar (TL031) and Willow (TL042) Creeks. Gold was reconcentrated from these older Tertiary channels into the modern Cache Creek drainage (C.C. Hawley and Associates, Inc., 1978). Also see Cache Creek (TL029).

References

MRDS Number A011579; D002712

References

Reporters Madelyn A. Millholland (Millholland & Associates)
Last report date 8/10/1998