Unnamed Occurrences (ARDF - MM177; near Foraker Glacier), Kantishna Mining District, Denali Borough, Alaska, USAi

Regional Level Types
Unnamed Occurrences (ARDF - MM177; near Foraker Glacier)	- not defined -
Kantishna Mining District	Mining District
Denali Borough	Borough
Alaska	State
USA	Country

The Foraker pluton is in Denali National Park and Preserve.
Location: These occurrences are approximately on the boundary of the Mt. McKinley A-3 and Talkeetna D-3 quadrangles. For this record, the site is in the north-central part of section 20, T. 22 S., R. 20 W., Fairbanks Meridian. The location is generalized.
Geology: These occurrences are in the mid-Tertiary Foraker pluton, which has been dated at 38 Ma (Reed and Lanphere, 1974; Reed and Nelson, 1980). The pluton is composed mainly of biotite-hornblende granodiorite; it is chemically and mineralogically identical to the McGonagall batholith, which crops out north of the Denali fault in the Mt. McKinley quadrangle. The Foraker and McGonagall bodies formerly were continuous but have been offset by the Denali fault (Reed, 1961; Reed and Lanphere, 1973, 1974). Reed and Nelson (1980) suggest that the Foraker pluton hosts molybdenite-quartz veins, and report that cobbles of the pluton on the Yentna and Lacuna Glaciers in the Talkeetna quadrangle contain sparse fractures filled with chalcopyrite, molybdenite, and pyrite. The Foraker pluton in the Mt. McKinley quadrangle has not yet (2000) been explored in detail for mineral deposits, but its offset equivalent, the McGonagall granodiorite, probably is the source of antimony, copper, and precious-metal deposits in the mineral belt near Slippery Creek. The granodiorite on Mt. Eielson that is associated with zinc-lead deposits in the Mt. Eielson district (MM166) probably is also related to the McGonagall intrusion (Decker and Gilbert, 1978; Cole, 1998).
Workings: The part of the Foraker pluton in the Mt. McKinley quadrangle is in an extremely rugged and inaccessible area. As of the date of this record, it has not been prospected to any significant degree.
Age: Oligocene, roughly contemporaneous with the the Eocene or Oligocene emplacement age of the Foraker-McGonagall batholith (Lanphere 1973; 1974; Cole, 1998).

Commodities (Major) - Mo; (Minor) - Cu
Development Status: None
Deposit Model: Molybdenum-copper porphyry (Cox and Singer, 1986; models 17, 21a or 21b).

Other Databases

Link to USGS - Alaska:	MM177

Other Regions, Features and Areas containing this locality

References