CPSH Seminar Series: Cat Ross, UT Jackson School of Geosciences & Evan Carnahan, Texas ECE
September 7, 2022
Talk One: Cat Ross
Speaker: Cat Ross, Visiting Assistant Professor of Structural Geology, Jackson School of Geosciences
Host: Tim Goudge
Title: Impact crater thermochronometry and the effects of shock microstructures
Abstract: Impact cratering ages tie the cratering process to mass extinctions, environmental changes, and potential habitability of the early Earth. However, less than a quarter of terrestrial impact craters are accurately and precisely dated, but are a ubiquitous process on Earth and other terrestrial planets. In order to test the reliability of the zircon (U-Th)/He thermochronometer in precisely dating the impact as well as post-impact hydrothermal processes, we characterized the complex intragrain microstructures and correlate the shock features to the helium diffusion kinetics. We find that deformed grains produce younger ages, complicated diffusion kinetics, and record hydrothermal system processes.
Talk Two: Evan Carnahan
Speaker: Evan Carnahan, Graduate Student, Texas Electrical and Computer Engineering, UT Austin
Host: Tim Goudge
Title: Role of impact brines in Europa’s habitability
Abstract: Impacts into icy bodies often generate near-surface melt chambers and thermal perturbations that soften the ice. We find these melt chambers rapidly sink into the underlying ocean with tens of cubic kilometers of surface material. The sinking of melt chambers modifies crater morphology, affects cryovolcanism, creates conduits through the ice for surface-to-ocean exchange, and may supply the oxidants required for habitability to subsurface oceans.
