Banner Grange pluton
Banner Grange pluton
Late Jurassic, ~158 Ma
Tonalite and granodiorite southwest of Grass Valley. This pluton has a zircon U-Pb age of ~158 Ma (Day and Bickford, 2004). Intrudes across contact between units YOSD and YOSV. Interpreted as part of the plutonic component of the Smartville Volcanic complex.