Unnamed (northeast wall of Eldridge Glacier) (ARDF #HE067) Cu

Unnamed (northeast wall of Eldridge Glacier)

Occurrence, Probably inactive

Commodities and mineralogy

Main commodities	Cu
Other commodities	Ag; Au; Ni
Ore minerals	chalcopyrite; malachite; pyrite

Geographic location

Quadrangle map, 1:250,000-scale	HE
Quadrangle map, 1:63,360-scale	A-6
Latitude	63.01
Longitude	-149.99
Nearby scientific data	Find additional scientific data near this location
Location and accuracy	This occurrence is at an elevation of about 2,400 feet in a stream valley draining the northeast wall of Eldridge Glacier. It is in sec. 14, T. 22 S., R. 13 W., of the Fairbanks Meridian. The localion is accurate to within 0.5 mile. This is locality 27 of Cobb (1978: OFR 78-1062).

Geologic setting

Geologic description The country rocks in the area of this occurrence are a tectonically intermixed assemblage of Upper Devonian serpentinite, basalt, chert, and gabbro. The occurrence consists of massive pyrite and chalcopyrite in irregular and veinlike masses in serpentinite. Some of the chalcopyrite is oxidized to malachite. Rock samples contained 15 ppm silver, 0.1 ppm gold, 50 ppm nickel and 7.5% copper (Hawley and Clark, 1974). The sulfide minerals herein are assumed to be remobilized syngenetic magmatic segregations in the mafic host rocks.
Geologic map unit	(-149.992280150589, 63.009514144386)
Mineral deposit model	Cyprus massive sulfide (Cox and Singer, 1986; model 24a)
Mineral deposit model number	24a
Age of mineralization	Probably Late Devonian, remobilized in Late Mesozoic or Tertiary.

Production and reserves

Workings or exploration	Rock samples contained 15 ppm silver, 0.1 ppm gold, 50 ppm nickel and 7.5% copper (Hawley and Clark, 1974).
Indication of production	None

References

MRDS Number	A011310
References Clark, A.L., and Cobb, E.H., 1972, Metallic mineral resources map of the Healy quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-394, 1 sheet, scale 1:250,000. Cobb, E.H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Healy quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-1062, 113 p. Hawley, C.C., Clark, A.L., Herdrick, M.A., and Clark, S.H.B., 1969, Results of geological and geochemical investigations in an area northwest of the Chulitna River, central Alaska Range: U.S. Geological Survey Circular 617, 19 p.
Reporters	N. Van Wyck (Stevens Exploration Management Corporation)
Last report date	4/7/2000