Four multicyclic complex calderas and smaller ignimbrite shields located within the Altiplano Puna Volcanic Complex of the Central Andes (APVC) erupted 13000 km³ of magma within the last 11 Ma. One of the largest and mos ...

Eleven sedimentary and volcanic rock units are mapped and described in the thesis area, and chronicle the dynamic geologic history of the Tillamook embayment from the Oligocene through the middle Mlocene. The oldest uni ...

Snow Peak is a voluminous shield volcano located ~50 km west of the axis of the modern Cascade arc. A previously published K-Ar age estimate indicates that the Snow Peak lavas are ~3 Ma. Subsequently, the preliminary r ...

New data are presented that provide evidence for the onset of extensional deformation in the Northwestern Basin and Range within 1 million years after the eruption of the Steens Basalt at 16.5 Ma. New geologic mapping (1 ...