Scheelite Intrusive Suite
Scheelite Intrusive Suite
Early Jurassic(?) and Late Triassic, ~197-226 Ma
Occurs in eastern Sierra Nevada, west and southwest of Mono Lake. Chiefly weakly to moderately foliated granodiorite and granite. Generally metamorphosed to upper amphibolite facies. This pluton has zircon U-Pb ages from ~197-226 Ma (Chen and Moore, 1982; Stern and others, 1981; Barth and others, 2011), excluding an anomalously young age of ~154 Ma (Chen and Moore, 1982; Wooden and others, 1999) that probably represents small outliers of nearby younger intrusive suites. This unit also includes biotite K-Ar ages of ~69-210 Ma, hornblende K-Ar ages of ~84-206 Ma (Kistler and others, 1966; Evernden and Kistler, 1970), a hornblende Ar-Ar age of ~206 Ma (Crowder and others, 1973), and apatite fission track ages of ~76 and ~88 Ma and a sphene fission track age of ~82 Ma (Naeser and Dodge, 1969). Major plutons: granite of Lee Vining Canyon, Tungsten Hills Granite, Wheeler Crest Granodiorite, granodiorite of Mono Dome, and granite (quartz monzonite) of Mono Lake. Suite includes Laurel-Convict felsite intruded along Laurel-Convict fault in Mount Morrison roof pendant. Unit, together with coeval High Sierra terrane volcanic and sedimentary rocks (unit HSV), forms High Sierra arc.