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Granitic rocks

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Mostly tonalite and quartz diorite but including lesser amounts of other granitoid rocks. Potassium-argon ages determined on hornblende indicates plutons range in age from 143 to 166 Ma (Hotz, 1971)
State Oregon
Name Granitic rocks
Geologic age Late Jurassic and Early Cretaceous
Lithologic constituents
Major
Igneous > Plutonic > Dioritic > Quartz-diorite (Pluton)
Igneous > Plutonic > Dioritic > Diorite (Pluton)
Minor
Igneous > Plutonic > Granitic > Tonalite (Pluton)
Incidental
Igneous > Plutonic > Gabbroic > Gabbro (Pluton)
References

Walker, G.W. and MacLeod, N.S., 1991, Geologic map of Oregon: U.S. Geological Survey, scale 1:500,000.

Irwin, W.P., 1994, Geologic map of the Klamath Mountains, California and Oregon: U.S. Geological Survey Miscellaneous Investigations Series Map I-2148, scale 1:500,000.

https://pubs.er.usgs.gov/publication/i2148
NGMDB product
Counties Douglas - Grant - Jackson - Josephine - Lane