Dr. Maddie Lewis
U Wyoming

Topic: Tying caldera-forming eruptions to their magma storage regions: timing, magma compositions, and storage conditions

Academic Host: Kevin Mahan

Abstract: Caldera-forming eruptions are among the largest and most disruptive volcanic events in Earth history. Throughout the mid-Cenozoic, the Great Basin experienced an extensive period of explosive silicic volcanism, which produced massive ash-flow tuff deposits and calderas created by ~250 eruptions. Tectonically driven extension and tilting of this region created uniquely exposed upper-crustal cross sections through caldera-forming volcanic systems and associated plutonic regions. Mineral chemistry and geochronology through cross sections of multiple Oligocene calderas in central Nevada reveal changes in temperature and volatile content in the magma storage regions leading up to and following major eruptions. Though long extinct, these volcanic systems offer insights into magma storage regions that can inform our understanding of magmatic activity at modern explosive silicic volcanoes.