Unnamed (tributary to West Fork Maclaren River)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Zn
Ore minerals sphalerite or oxidized zinc mineral

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale B-6
Latitude 63.3408
Longitude -146.7357
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at an elevation of about 4,000 feet in a northeast-flowing part of a west tributary of the West Fork Maclaren River, near the center of section 23, T. 18 S., R. 5 E., Fairbanks Meridian. It corresponds to locality A30 of Kurtak and others (1992).

Geologic setting

Geologic description

The area of the occurrence is underlain by schist and amphibolite probably formed during metamorphism of Cretaceous age (Nokleberg and others, 1982). Zinc contained in a mineral (probably sphalerite or an oxidation product) occurs in a breccia zone 5 to 15 feet wide (Nokleberg and others, 1990). Four samples of breccia contained between 0.12 and 0.18 percent zinc (Kurtak and others, 1992).
Geologic map unit (-146.73797201499, 63.3403652508831)
Mineral deposit model Zinc-bearing fault zone.
Age of mineralization Probably Late Cretaceous or younger; mineralized host breccia postdates Cretaceous (?) metamorphism.
Alteration of deposit Possible oxidation of zinc mineral.

Production and reserves

Workings or exploration Surface samples of mineralized breccia contain from 0.12 to 0.18 percent zinc (Kurtak and others, 1992).
Indication of production None