Unnamed (south of Orange Hill)

Prospect, Inactive

Commodities and mineralogy

Main commodities Ag; Cu

Geographic location

Quadrangle map, 1:250,000-scale NB
Quadrangle map, 1:63,360-scale A-4
Latitude 62.1854
Longitude -142.8493
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is near the mouth of Nikonda Creek, east of the terminus of Nabesna Glacier. It is at an elevation of about 3,000 feet, 5,500 feet south of Orange Hill, and 1,000 feet east of the glacier. The site is in the NE1/4 of section 29, T. 5 N., R. 14 E. of the Copper River Meridian. This is National Park Service locality WRST-30 (unpublished data) and the coordinates for this prospect were provided by the National Park Service.

Geologic setting

Geologic description

An unpublished National Park Service map and accompanying database identify this locality as a copper-silver porphyry prospect that was explored by a 15-foot adit. It may be part of the Orange Hill porphyry-copper system (NB043) (Linn, 1973; Hollister and others, 1975; Richter and others, 1975). The Orange Hill deposit is in quartz diorite and granodiorite of the southwestern border zone of the mid-Cretaceous Nabesna pluton. The granitic rocks in turn are intruded by quartz-plagioclase porphyry that is also inferred to be Cretaceous in age (Richter, 1973). At this site, the prospect is within Paleozoic volcanic rocks in the contact zone to the Nabesna pluton (Richter, 1973).
Geologic map unit (-142.851426563478, 62.1850089857212)
Mineral deposit model Porphyry Cu-Mo (Cox and Singer, 1986; model 21a)
Mineral deposit model number 21a
Age of mineralization Mid-Cretaceous? The prospect is in volcanic rocks in the contact zone of the mid-Cretaceous Nabesna pluton (NB043).
Alteration of deposit This prospect may be in the chlorite, minor sericite, and anhydrite outer alteration zone of the Orange Hill deposit (NB043).

Production and reserves

Workings or exploration A 15 foot adit was driven at this prospect.
Indication of production None

Additional comments

The prospect is in the Wrangell-St. Elias National Preserve.

References

References

Hollister, V.F., Anzalone, S.A., and Richter, D.H., 1975, Porphyry copper belts of southern Alaska and contiguous Yukon Territory: Canadian Mining and Metallurgical Bulletin, v. 68, no. 756, p. 104-112.
Linn, G.W., 1973, Geology of Orange Hill, Alaska: Berkeley, University of California, M.A. thesis, 119 p.
Reporters Travis L. Hudson (Applied Geology)
Last report date 11/24/2002