Unnamed (east of upper Little Yetna River) (ARDF #ID047) Au

Unnamed (east of upper Little Yetna River)

Occurrence, Inactive

Commodities and mineralogy

Main commodities	Au
Other commodities	Ag; Hg
Ore minerals	iron oxide
Gangue minerals	chalcedony

Geographic location

Quadrangle map, 1:250,000-scale	ID
Quadrangle map, 1:63,360-scale	C-6
Latitude	62.52423
Longitude	-158.63213
Nearby scientific data	Find additional scientific data near this location
Location and accuracy	This occurrence is on hill 540, about 1 mile east of the head of the Little Yetna River. The occurrence is in the SE1/4 SE1/4, section 12, T. 28 N., R. 51 W., of the Seward Meridian. The location is accurate.

Geologic setting

Geologic description This occurrence is in a zone of unknown size marked by Silicification of felsic volcanic rocks. The silicification is largely chalcedony. The volcanics are part of the Upper Cretaceous or early Tertiary, Yetna River volcanic field (Miller and Bundtzen, 1994; Miller, Bundtzen, and Gray, 2005). Iron-oxide-rich gossan after sulfides was noted in part of the zone. Two samples contained 100 parts per billion (ppb) gold, and 140 ppb mercury (McGimsey and others, 1988).
Geologic map unit	(-158.634548761729, 62.5235511011516)
Mineral deposit model	Hot springs gold-silver? (Cox and Singer, 1986; deposit model 25a).
Mineral deposit model number	25a?
Age of mineralization	Unknown; the rhyolite is part of the Upper Cretaceous or early Tertiary, Yetna River volcanic field (Miller and Bundtzen, 1994).
Alteration of deposit	Chalcedonic silicification; iron oxide alteration.

Production and reserves

Workings or exploration	Samples were collected by the U.S. Geological Survey in 1984 and 1985 (McGimsey and others, 1988).
Indication of production	None

References

References McGimsey, R.G., Miller, M.L., and Arbogast, B.F., 1988, Paper version of analytical results, and sample locality map for rock samples from the Iditarod quadrangle, Alaska: U.S. Geological Survey Open-File Report 88-421-A, 110 p., 1 sheet, scale 1:250,000. Miller, M.L., and Bundtzen, T.K., 1994, Generalized geologic map of the Iditarod quadrangle, Alaska showing potassium-argon, major oxide, trace element, fossil, paleocurrent, and archeological sample localities: U.S. Geological Survey Miscellaneous Field Studies Map MF-2219-A, 48 pages; 1 sheet, scale 1:250,000. Miller, M.L., Bundtzen, T.K., and Gray, J.E., 2005, Mineral resource assessment of the Iditarod quadrangle, west-central Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-2219-B, scale 1:250,000, pamphlet.
Reporters	T.K. Bundtzen (Pacific Rim Geological Consulting, Inc.), M.L. Miller (U.S. Geological Survey); and C.C. Hawley (Hawley Resource Group)
Last report date	5/18/2003