Chronology of pluton emplacement and regional deformation in the southern Sierra Nevada batholith, California

Cretaceous plutonic rocks of the southern Sierra Nevada batholith between latitudes 35.5°N and 36°N lie in a strategic position that physically links shallow, subvolcanic levels of the batholith to lower-crustal (~35 km deep) batholithic rocks. This region preserves an oblique crustal section through the southern Sierra Nevada batholith. Prior studies have produced large U/Pb zircon data sets for an aerially extensive region of the batholith to the north of this area and for the lower-crustal rocks of the Tehachapi complex to the south. We present a large set of new U/Pb zircon age data that ties together the temporal relations of pluton emplacement and intra-arc ductile deformation for the region. We defi ne fi ve informal intrusive suites in the area based on petrography, structural setting, U/Pb zircon ages, and patterns in initial 87Sr/86Sr (Sri). Two regionally extensive intrusive suites, the 105–98 Ma Bear Valley suite and 95–84 Ma Domelands suite, underlie the entire southwestern and eastern regions of the study area, respectively, and extend beyond the limits of the study area. A third regionally extensive suite (101–95 Ma Needles suite) cuts out the northern end of the Bear Valley suite and extends for an unknown distance to the north of the study area. The Bear Valley and Needles suites are tectonically separated from the Domelands suite by the proto–Kern Canyon fault, which is a regional Late Cretaceous ductile shear zone that runs along the axis of the southern Sierra Nevada batholith. The 105–102 Ma Kern River suite also lies west of the proto–Kern Canyon fault and constitutes the subvolcanic plutonic complex for the 105–102 Ma Erskine Canyon sequence, an ~2-km-thick silicic ignimbrite-