Walker Lake intrusive suite
Walker Lake intrusive suite
Late Cretaceous and Late Jurassic, ~83-96 and ~155 Ma
Occurs in west-central Nevada and eastern Sierra Nevada. Chiefly granodiorite and quartz monzonite with lesser granite, diorite, and gabbro. Includes coarse-grained, massive, light-gray quartz monzonite with numerous local aplite and pegmatite dikes, and medium- to coarse-grained massive granodiorite with local aplite and pegmatite dikes. Predominantly Late Cretaceous, with one zone of Late Jurassic plutons east of Antelope Valley (Stewart and others, 1989). Zircon U-Pb ages of ~83-96 Ma and whole-rock Rb-Sr ages of ~82 and ~88 Ma (Robinson, 1985; Stewart and others, 1989), along with whole rock Rb-Sr and feldspar Pb-Pb ages of ~155 Ma (Robinson and Kistler, 1986; Wooden and others, 1999), as well as one biotite K-Ar age of ~119 Ma and hornblende K-Ar of ~61 and 82 Ma (Evernden and Kistler, 1970). The older part is coeval with and potentially intrusively linked to marine metavolcanic rocks (unit WLV) in the Walker Lake terrane.