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Gabbro and ultramafic rocks associated with granitic plutons (Cretaceous and Jurassic)

Predominantly hornblende gabbro, gabbro, and olivine gabbro, but includes pyroxenite, hornblende pyroxene, and minor peridotite, dunite, and serpentinite (Smith and others, 1982)
State Oregon
Name Gabbro and ultramafic rocks associated with granitic plutons (Cretaceous and Jurassic)
Geologic age Late Jurassic and Early Cretaceous
Primary rock type gabbro
Secondary rock type pyroxenite
Other rock types peridotite; serpentinite
Lithologic constituents
Major
Igneous > Plutonic > Gabbroic > Gabbro (Pluton)
Minor
Igneous > Plutonic > Ultramafic > Pyroxenite (Pluton)
Incidental
Igneous > Plutonic > Ultramafic > Peridotite (Pluton)
Metamorphic > Serpentinite
Map references
Walker, G.W. and MacLeod, N.S., 1991, Geologic map of Oregon: U.S. Geological Survey, scale 1:500,000.
Unit references
Walker, G.W. and MacLeod, N.S., 1991, Geologic map of Oregon: U.S. Geological Survey, scale 1:500,000.
Counties Jackson - Josephine