Boot Flap Prospect, Delta River Mining District, Southeast Fairbanks Census Area, Alaska, USAi

Regional Level Types
Boot Flap Prospect	Prospect
Delta River Mining District	Mining District
Southeast Fairbanks Census Area	Census Area
Alaska	State
USA	Country

Location: The Boot Flap prospect is at an elevation of 5,100 feet three-quarters of a mile east of the toe of the Eureka Glacier. It is about one-half mile south of peak 6563, in the SE1/4SE1/4 section 25, T. 18 S., R. 7 E., Fairbanks Meridian.
Geology: The rocks at the Boot Flap prospect appear to be a sill-like body of Upper Triassic gabbro and serpentinized peridotite and dunite (Rose, 1966 [ADMM GR 20, figure 2]). The body is informally called the Eureka ultramafic complex, which occupies strands of the Broxson Gulch thrust fault (W.T. Ellis, unpublished data, 1996). At the prospect, coarse-grained disseminated sulfides, principally pyrrhotite, occur in olivine melagabbro. Sulfide abundance increases to a maximum of about 10 percent downward in the sill-like body, and small amounts of magnetite, chalcopyrite, and pentlandite accompany the pyrrhotite. Samples contain as much as 0.03 percent copper, 0.09 percent nickel, 20 parts per billion (ppb) palladium, and 20 ppb platinum (W.T. Ellis, unpublished data, 1996).
Workings: The prospect is on active Fort Knox Gold Resource claims.
Age: Late Triassic, the age of the host rock.
Alteration: All of the ultramafic rock units are moderately to strongly serpentinized.

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

Other Databases

Link to USGS - Alaska:	MH102

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References