Intermediate andesite and intermediate flows and breccias

Andesite flows and breccias and other related rocks of intermediate composition such as dacite, rhyodacite, quartz latite, and biotite-hornblende porphyries. This unit includes units mapped as the South Willow Formation on the Washoe North map, the Milltown Andesite on the Nye South and Esmeralda County maps, the Mizpah Trachyte on the Nye North map, and other units. It corresponds to unit Ta2 on the 1978 State map. It crops out in all counties except Clark, Eureka, Lyon, Douglas, and Carson.
State Nevada
Name Intermediate andesite and intermediate flows and breccias
Geologic age lower Miocene and Oligocene
Lithologic constituents
Igneous > Volcanic > Felsic-volcanic > Quartz-latite (Flow, Volcaniclastic-volcanic breccia)
Igneous > Volcanic > Mafic-volcanic > Andesite (Flow, Volcaniclastic-volcanic breccia)
Igneous > Volcanic > Felsic-volcanic > Dacite (Flow, Volcaniclastic-volcanic breccia)
Igneous > Volcanic > Felsic-volcanic > Trachyte (Flow, Volcaniclastic-volcanic breccia)Mizpah Trachyte on the Nye North map
NGMDB product
Counties Churchill - Elko - Esmeralda - Eureka - Humboldt - Lander - Lincoln - Mineral - Nye - Pershing - Washoe - White Pine