Eagle Creek

Mines, Inactive

Commodities and mineralogy

Main commodities Au
Other commodities Ag; Ba; Cu; PGE
Ore minerals barite; gold; native copper; pge; pyrite
Gangue minerals magnetite

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale A-1
Latitude 63.0075
Longitude -144.4377
Nearby scientific data Find additional scientific data near this location
Location and accuracy
Eagle Creek is a 7.5-mile-long tributary to the East Fork Chistochina River. The mouth of the creek is on the Gulkana quadrangle. The Eagle Creek mine is a few hundred feet east of the center of section 10, T. 14 N., R. 5 E., Copper River Meridian (Moffit, 1944; Richter and others, 1977). (A feature shown in the SE1/4 section 34, T. 15 N., R. 5 E., Copper River Meridian, on the topographic map of the Mount Hayes A-1 quadrangle is almost certainly a landslide, not tailings [see Richter and others, 1977].)
The Eagle Creek mine is locality 30 on figure 6 of Cobb (1979 [OFR 79-238]) and locality 18 in table 3 of Nokleberg and others (1991). Eagle Creek was fairly extensively prospected, and there are other prospect sites nearby. The location given here is accurate as a general central location on the creek and as the location of some mining activity.

Geologic setting

Geologic description

Bedrock in the upper part of Eagle Creek consists of limestone, argillite, chert, and porcellanite (Richter, 1967; Richter and others, 1977); the lower canyon and lowlands below the canyon are cut in volcanic flows, clastic debris, and tuff that is locally pyritic and silicified (Moffit, 1944; Richter and others, 1977). Bedrock at the mine consists mainly of andesitic volcanic rocks of the Tetelna Volcanics of Pennsylvanian age. The Tetelna is overlain by volcanic and impure limy rocks of the Slana Spur Formation of Pennsylvanian and Permian age. Up the canyon, the Slana Spur Formation is successively overlain by Eagle Creek Formation of Permian age and the Nikolai Greenstone of Late Triassic age. Small granitic plutons are present in upper Eagle Creek. The placer mine site is just west of the type area for the Slana Spur Formation (Richter and Dutro, 1975). The placer mine is in valley alluvium of Holocene age. The area is extensively mantled by glacial drift of Wisconsin age.
The placer contains gold that varies from flaky and smooth to rough and heavy (Moffit, 1944). Magnetite is abundant enough in the concentrate to plug sluice boxes; magnetite ranges from fine sand to small cobble in size. Barite is also present in the concentrate, as is native copper, and platinum metals have been reliably reported (Moffit, 1944). As recognized by Moffit (1944), the presence of some coarse rough gold is consistent with short transport and a local bedrock source, as is the presence of barite.
Geologic map unit (-144.439923213712, 63.0071063683587)
Mineral deposit model Placer Au-PGE (Cox and Singer, 1986 model 39a).
Mineral deposit model number 39a
Age of mineralization Holocene; probably some gold and heavy metals reconcentrated from Wisconsin-age glacial drift.
Alteration of deposit Volcanic rocks near the site are silicified and pyritized.

Production and reserves

Workings or exploration Surface workings and numerous shallow prospect pits. Eagle Creek was actively explored and worked in a small way by the White brothers in 1939 to 1942 (Moffit, 1944). A hydraulic operation begun in 1942 was not active after World War II (Moffit, 1954).
Indication of production Yes; small
Reserve estimates Probable reserves; an operation planned to begin in 1942 was halted by World War II (Moffit, 1954).

References

MRDS Number A011780; M045389

References

Reporters W.T. Ellis (Alaska Earth Sciences) and C.C Hawley (Hawley Resource Group)
Last report date 7/14/2003