Unnamed Occurrence (ARDF - MH285; northwest of Chistochina Glacier), Chistochina Mining District, Southeast Fairbanks Census Area, Alaska, USAi

Regional Level Types
Unnamed Occurrence (ARDF - MH285; northwest of Chistochina Glacier)	- not defined -
Chistochina Mining District	Mining District
Southeast Fairbanks Census Area	Census Area
Alaska	State
USA	Country

Location: This occurrence is float on a moraine on the mountain northwest of the 1966 terminus of the glacier at the head of the Chistochina River. It is in the southern part of the SE1/4SE1/4 section 4, T. 20 S., R. 15 E., Fairbanks Meridian. The occurrence corresponds to locality 18 on figure 1 of Rose (1967) and locality 9 on figure 6 of Cobb (1979 [OFR 79-238]) and is included with nearby site MH284 in locality 133 on table 2 of Nokleberg and others (1991).
Geology: A dunite boulder was collected on glacial moraine near the projected contact of an ultramafic body consisting of dunite, peridotite, and pyroxenite with argillite of the Eagle Creek Formation (Rose, 1967). The ultramafic body is about 1,500 feet across and extends for about one mile, sandwiched between quartz monzonite to the south and argillite of the Eagle Creek Formation to the north. The boulder contained abundant pyrite and probably chalcopyrite and pyrrhotite; it assayed 0.75 percent copper, a trace of gold and platinum, 0.12 ounce of silver per ton, and 0.2 percent nickel (Rose, 1967). The boulder was probably derived locally.
Workings: No workings are reported. The sulfide-bearing boulder was found during mapping by Rose (1967).
Age: Probably related to ultramafic rocks of Late Triassic age.

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

Other Databases

Link to USGS - Alaska:	MH285

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References