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

Names and other identifiers

Alternate names Brenmac
Tract name Cascade Arc (003pCu9014)
Site status deposit

Geographic location

Country United States
State or province Washington
Geographic location -121.503611111, 48.008611111
Geologic map unit -121.503611111, 48.008611111
Nearby data

Geologic information

Deposit type Porphyry copper
Deposit subtype Cu-Mo
Age (Ma) 28Ma
Age determination method unknown
Age range 28 Ma
Age reference Singer and others (2008)
Minerals arsenopyrite, barite, biotite, bornite, chalcopyrite, chlorite, epidote, galena, kaolinite, molybdenite, pyrite, pyrrhotite, scheelite, sericite, sphalerite, tourmaline
Associated rocks breccia, conglomerate, argillite, chert, conglomerate, graywacke, hornfels, mafic volcanic rocks, marble, quartz diorite, skarn, tonalite
Tectonic setting continental margin
Stratigraphic age Oligocene

Commodity and development information

Development status Occurrence
Major commodities Cu
Tonnage (Mt) 64Mt
Cu grade (%) 0.35%
Mo grade (%) 0.026%
Au grade (g/t) 0.023g/t
Contained copper 220,000t
Gold-Moly ratio 0.88

Reference information

Comments 0.062% WO3.
Study area name United States
References Derkey and others (1990); Lasmanis (1995); Singer and others (2008)
Site reference U.S. Geological Survey National Mineral Resource Assessment Team (2002)