Seth D. Burgess

My doctoral research focused on utilizing accessory mineral U-Pb ID-TIMS (isotope dilution thermal ionization mass spectrometry) geochronology to examine the plausibility of a causal link between large igneous province (LIP) magmatism and mass extinction, with particular focus on the end-Permian and early-Jurassic extinction events. This work yielded high-precision timelines for extinction and LIP magmatism, as well as the ability to resolve their relative timing, and lead to a general model predicting the efficacy of magmatism as the primary trigger of mass extinction.

My current research is focused on application of uranium-based geochronometers (U-Pb, U-Th, (U-Th)/He) to date volcanic rocks by utilizing TIMS, SIMS (secondary ion mass spectrometry) analysis on accessory phase minerals (e.g., zircon, allanite) primarily for the purpose of accurately determining the timing of voluminous eruption and for constructing comprehensive eruption histories of long-lived volcanic systems characterized by potential future volcanic hazard.

Ongoing projects include: (1) Leading a group of CalVO scientists in an effort to better understand the threat of volcanic hazards from the Clearlake Volcanic Field (CLVF). The CLVF is the closest young, long-lived volcanic system to the densely populated CA Bay Area. In this project I'm employing U-Pb zircon surface dating to better constrain the eruption history of the volcanic field. (2) Determining the timing of large Pleistocene volcanic eruptions in Alaska by zircon surface U-Th-Pb SIMS geochronology. (2) (3) Using zircon U-Pb SIMS and TIMS to date the eruption of key Neogene and Quaternary stratigraphic-marker volcanic ash beds in western North America for use in regional correlation and paleo-climate and paleo-environment reconstruction. (4) Employing zircon and allanite U-Th SIMS dating of the Pleistocene record of rhyolite dome extrusion at the Coso volcanic field (California) in order to better constrain magma petrogenesis and more accurately assess hazard potential. (5) Using zircon U-Pb ID-TIMS dating of volcanic ash beds intercalated with the Miocene Columbia River LIP basalt flows to investigate eruption tempo at the millennial scale, which informs magma generation and climate feedback models.