Unnamed Occurrence (ARDF - SK018; near Mt. Barnard), Glacier Bay Mining District, Juneau Mining District, Alaska, USAi

Regional Level Types
Unnamed Occurrence (ARDF - SK018; near Mt. Barnard)	- not defined -
Glacier Bay Mining District	- not defined -
Juneau Mining District	Mining District
Alaska	State
USA	Country

There are probably similar deposits in the vicinity, but the rugged terrain and glaciers hamper investigation (Brew and others, 1978). The deposit is within Glacier Bay National Park and Preserve where exploration and development is restricted.
Location: This occurrence is at an elevation of 5,475 feet in Glacier Bay National Park and Preserve; it is at the top of a nunatak, 2.6 miles southeast of the summit of Mount Barnard. It is shown as location 38 on Plate III of Brew and others (1978) and location SE27 by Nokleberg and others (1987).
Geology: The following description is summarized from Brew and others (1978). Small pods up to 0.5 foot thick of pyrrhotite and pyrite with a trace of chalcopyrite are associated with andesite, greenstone, epidote, and thin bands of limestone or marble. Abundant chloritic and some sericitic alteration are in a contact metamorphic zone near a Cretaceous granitic intrusive. A grab sample of one pod contained 1,000 ppm copper, 0.1 ppm gold, 0.5 ppm silver, and 100 ppm cobalt. The mineralization is probably Cretaceous, based on the age of the granitic intrusive which is associated with it.
Age: Probably Cretaceous or younger based on its association with nearby granitic intrusive rocks (Brew and others, 1978).
Alteration: Chloritization, epidotization, sericitization.

Commodities (Major) - Cu; (Minor) - Ag, Au, Co
Development Status: None
Deposit Model: Probable replacement deposit adjacent to intrusive (Cox and Singer, 1986; model

Other Databases

Link to USGS - Alaska:	SK018

Other Regions, Features and Areas containing this locality

References