I am a research geologist in the Volcano Science Center specializing in accessory mineral geochronology.
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.
Professional Experience
Research Geologist
U.S. Geological Survey, California Volcano Observatory, Menlo Park, CA, 2016–Mendenhall Postdoctoral Fellow
U.S. Geological Survey, California Volcano Observatory, Menlo Park, CA, 2014–2016Research/Teaching Assistant
Massachusetts Institute of Technology, Cambridge, MA, 2008–2014Staff Scientist
NASA-Ames Research Center, Sunnyvale, CA, 2006–2007California State University Lecturer
San Jose State University, San Jose, CA, 2006–2007Soil Scientist
USDA, Natural Resource Conservation Service, Soil Survey of Yosemite National Park, CA, 2001
Education and Certifications
Massachusetts Institute of Technology, Ph.D. Geology 2014
Thesis: High–precision U-Pb geochronology of large igneous provinces and mass extinctions: testing coincidence and causationSan Jose State University, M.S. Geology 2006
Thesis: Field, geochemical, and geochronologic study of the inner Tuolumne Intrusive Series, Sierra Nevada BatholithCalifornia Polytechnic State University, B.S. Soil Science 2002
Thesis: Effect of lichen colonization on mineral weathering
Affiliations and Memberships*
American Geophysical Union since 2006
Geological Society of America since 2005
European Geophysical Union 2010-2014
Honors and Awards
National Academy of Sciences (PNAS), Cozzarelli Prize in Physical and Mathematical Sciences, 2014
Outstanding Teaching Award, Massachusetts Institute of Technology, 2012
Student Research Scholarship, Massachusetts Institute of Technology, 2009, 2010, 2011
Presidential Fellow, Massachusetts Institute of Technology, 2007
Outstanding Thesis Award, College of Science, San Jose State University, 2006
Norman H. Doloff Scholarship, San Jose State University, 2004
National Outstanding Senior, National Agronomy Student Recognition Program, 2002
Outstanding Student in the College of Agriculture, California Polytechnic State University, 2002
Royce Lambert Scholarship for Outstanding Student, California Polytechnic State University, 1998, 1999
Science and Products
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government