Unnamed Occurrence (ARDF - MH096; west of the terminus of Eureka Glacier), Valdez Creek Mining District, Southeast Fairbanks Census Area, Alaska, USAi

Regional Level Types
Unnamed Occurrence (ARDF - MH096; west of the terminus of Eureka Glacier)	- not defined -
Valdez Creek Mining District	Mining District
Southeast Fairbanks Census Area	Census Area
Alaska	State
USA	Country

Location: This occurrence is at an elevation of about 3,600 feet at the west edge of the terminus of Eureka Glacier (as shown on the 1951 [rev. 1978] edition of the Mount Hayes B-5 topographic map). The occurrence is in the NE1/4NE1/4 section 10, T. 19 S., R. 7 E., Fairbanks Meridian.
Geology: This occurrence is in the westernmost exposure of the Fish Lake ultramafic complex, a large layered lopolith of Late Triassic age considered to be comagmatic with the Upper Triassic Nikolai Greenstone (Nokleberg and others, 1991). This occurrence consists of sulfide minerals disseminated in the ultramafic complex. Chalcopyrite and pyrrhotite form about 5 to 7 percent of the olivine-clinopyroxene wehrlite. The wehrlite is about 100 feet stratigraphically below locally pegmatitic gabbro. Grab samples of sulfide-bearing wehrlite contained as much as 1,180 parts per million (ppm) copper, 1,650 ppm nickel, 58 parts per billion (ppb) palladium, and 50 ppb platinum (W.T. Ellis, unpublished data, 1996).
Workings: The occurrence is covered by active Fort Knox Gold Resources claims (W.T. Ellis, unpublished field notes, 1996).
Age: Late Triassic, synchronous with emplacement of the mafic-ultramafic rocks.
Alteration: The wehrlite is weakly serpentinized.

Commodities (Major) - Cu, Ni; (Minor) - Pd, Pt
Development Status: None
Deposit Model: Ni-Cu-PGE in differentiated mafic-ultramafic sill.

Other Databases

Link to USGS - Alaska:	MH096

Other Regions, Features and Areas containing this locality

References