Unnamed (head of Caribou Creek) (ARDF #ID055) Ag, Bi, Sn

Unnamed (head of Caribou Creek)

Occurrence, Inactive

Commodities and mineralogy

Main commodities	Ag; Bi; Sn
Other commodities	As; Au; Cu
Ore minerals	iron oxide

Geographic location

Quadrangle map, 1:250,000-scale	ID
Quadrangle map, 1:63,360-scale	C-4
Latitude	62.52836
Longitude	-157.86091
Nearby scientific data	Find additional scientific data near this location
Location and accuracy	This occurrence is on a small but prominent knob, hill 877, on an unnamed fork of Caribou Creek. The occurrences is at an elevation of about 700 feet, about 0.5 mile west to west-southwest of the center of section 8, T. 28 N., R. 46 W., of the Seward Meridian. The location is accurate.

Geologic setting

Geologic description This occurrence consists of altered, iron-oxide-stained hornfels near a biotite-bearing, fine grained intrusion. The intrusion has been radiometrically dated as 70.2 Ma (Miller and Bundtzen, 1994; Miller, Bundtzen, and Gray, 2005). The mineralized body is of uncertain size and orientation. One grab sample of mineralization rock contained 2,000 parts per billion (ppb) silver, 850 parts per million (ppm) arsenic, 200 ppm copper, 52 ppm bismuth, 30 ppm tin, and 50 ppb gold (McGimsey and others, 1988).
Geologic map unit	(-157.863307451315, 62.5276780437567)
Mineral deposit model	Sn-polymetallic deposit or Polymetallic vein (Cox and Singer, 1986; model 20b or 22c).
Mineral deposit model number	20b or 22c
Age of mineralization	Undated; the nearby intrusion is 70.2 Ma (Miller and Bundtzen, 1994).
Alteration of deposit	Iron oxide staining.

Production and reserves

Workings or exploration	The area was sampled by the Alaska Division of Geological and Geophysical Surveys and U.S. Geological Survey in 1986 (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	5/19/2003