Porphyry copper prospect in Alaska, United States

Names and other identifiers

Alternate names Unnamed (at head of Geroe Creek), MAS
Tract name Brooks Range (003pCu5008)
Site status prospect

Geographic location

Country United States
State or province Alaska
Geographic location -148.814, 67.6804
Geologic map unit -148.814, 67.6804
Nearby data

Geologic information

Deposit type Porphyry copper
Age (Ma) 395Ma
Age determination method Pb-Pb
Age range 395.0 Ma, 388.0 Ma, 381.0 Ma (Pb-Pb) (Inferred from ages from the nearby Baby Creek batholith and Horace Mountain plutons.)
Age reference Dillon and others (1996)
Minerals chalcopyrite, molybdenite, pyrite
Tectonic setting mixed
Stratigraphic age Devonian(?)

Commodity and development information

Development status Prospect
Major commodities Au, Cu, Mo
Minor commodities Pb
Gold-Moly ratio -9999

Reference information

Comments One of several quartz stockworks and altered zones in the northeast-trending belt of Devonian peraluminous biotite-muscovite granite of the Baby Creek batholith and Devonian, metaluminous biotite-hornblende granite and granodiorite of the Horace Mountain pluton. Sericitization and propylitization of porphyritic host rocks; veinlets in stockworks are accompanied by intense quartz-sericite-chlorite-(+/- epidote) alteration. A block of 239 claims was staked over this prospect in 1975–1976.
Study area name United States
References U.S. Geological Survey (2014a); Newberry and others (1986); Kurtak and others (2002); Dillon and others (1996)
Site reference U.S. Geological Survey National Mineral Resource Assessment Team (2002)