Nunatak

Porphyry copper (Cu-Mo) deposit in Alaska, United States

Names and other identifiers

GMRAP ID 14
Alternate names Muir Inlet
Tract name Southeast Alaska Tertiary (003pCu5005)
Site status deposit

Geographic location

Country United States
State or province Alaska
Geographic location -136.102777778, 58.9875
Geologic map unit -136.102777778, 58.9875
Nearby data

Geologic information

Deposit type Porphyry copper
Deposit subtype Cu-Mo
Minerals actinolite, albite, alunite, biotite, bornite, chalcopyrite, chlorite, enargite, epidote, malachite, pyrite, pyrrhotite, tetrahedrite
Associated rocks andesite dike, hornfels, quartz monzonite porphyry, rhyodacite porphyry, skarn, limestone, calcareous shale
Tectonic setting continental margin

Commodity and development information

Development status Occurrence
Major commodities Cu
Tonnage (Mt) 120Mt
Cu grade (%) 0.18%
Mo grade (%) 0.03%
Contained copper 220,000t
Gold-Moly ratio -9999

Reference information

Comments Grab sample: 1.2 g/t Au and 212 g/t Ag.
Study area name United States
References Brew and others (1978); MacKevett and others (1971); Nokleberg and others (1987); Singer and others (2008)
Site reference U.S. Geological Survey National Mineral Resource Assessment Team (2002)