Unnamed (ridge between Beaver and Tolstoi Creeks) (ARDF #ID018) Ag, Zn

Unnamed (ridge between Beaver and Tolstoi Creeks)

Occurrence, Inactive

Commodities and mineralogy

Main commodities	Ag; Zn
Other commodities	Au; Cu; Sb
Ore minerals	iron oxide; manganese oxide
Gangue minerals	tourmaline

Geographic location

Quadrangle map, 1:250,000-scale	ID
Quadrangle map, 1:63,360-scale	D-2
Latitude	62.98371
Longitude	-156.82805
Nearby scientific data	Find additional scientific data near this location
Location and accuracy	This occurrence is at an elevation of about 1,350 feet on a knob that is about 0.8 mile northeast of hill 2340. It is about 0.2 mile south of the northeast corner of section 3, T. 33 N., R. 40 W., of the Seward Meridian. The location is accurate.

Geologic setting

Geologic description This occurrence consists of rubble of iron-oxide-stained breccia in hornfels that is probably related to the Cretaceous Beaver Mountains pluton. Manganese-oxide-stained rosettes of tourmaline in the hornfels may be related to a nearby, potassically-altered andesite-porphyry dike. The occurrence is about 2 miles north of the northern contact of the Beaver Mountains pluton (Miller and Bundtzen, 1994; Miller, Bundtzen, and Gray, 2005). Grab samples contain up to 55.0 parts per million (ppm) silver, 1,000 ppm zinc, 500 ppm copper, 100 ppm antimony, and 100 parts per billion (ppb) gold (Bundtzen and Laird, 1982).
Geologic map unit	(-156.83040909087, 62.9830658530618)
Mineral deposit model	Polymetallic vein (Cox and Singer, 1986; model 22c).
Mineral deposit model number	22c
Age of mineralization	Probably related to the Beaver Mountains pluton which has been dated at 70.1 Ma (Bundtzen and Laird, 1982).
Alteration of deposit	Rocks altered to tourmaline greisen.

Production and reserves

Workings or exploration	Limited surface sampling was conducted in 1979 (Bundtzen and Laird, 1982).
Indication of production	None

References

References Bundtzen, T.K., and Laird, G.M., 1982, Geologic map of the Iditarod D-2 and eastern D-3 quadrangles, Alaska: Alaska Division of Geological and Geophysical Surveys Geologic Report 72, 1 sheet, scale 1:63,360. 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	5/11/2003