Current Research and Scholarly Interests
Research
My students and I study chemical and physical processes related to water-rock reaction in Earth's crust, and the geologic consequences of life's metabolic processes. As theoretical geochemists, we investigate the properties of solution-mineral reactions to predict the nature of elemental mass transfer by reactive fluids in weathering, diagenetic, hydrothermal, and metamorphic environments. Recent efforts focus on the environmental geochemistry of chromium and arsenic, CO2 sequestration in large igneous provinces, paleoclimate proxies preserved in weathered basaltic tephras of the North Atlantic Igneous Province, and exhumation rates of ultra-high pressure metamorphic rocks of China. Our geobiology efforts focus on the geologic consequences of the photosynthesis on early Earth, specifically processes leading to the rise of continents, and in historic times, the effects of synpandemic fire suppression and reforestation in tropical Americans on atmospheric CO2 during European conquest.
Teaching
I teach courses for graduate and undergraduate students on the geochemical thermodynamics of water-rock reactions relevant to understanding transport of elements of environmental concern, and to understanding diagenetic, hydrothermal, metamorphic, and igneous processes in Earth's crust. I teach a lower division undergraduate seminar on the geologic background and environmental impact of the California Gold Rush, a class that satisfies the university second year Writing and Rhetoric Requirement (WRR2), and I co-teach the Senior Seminar in GES, which satisfies the Writing in the Major requirement (WIM) for our undergraduates. For the past 22 years I have been the faculty advisor for Stanford's Outdoor Education Program (OEP), a group of student instructors who teach the Wilderness Skills Class in GES (GES 7A[Fall], 7B[Winter], and 7C[Spring])
Professional Activities
Associate editor, American Journal Science (1987-present); fellow, Mineralogical Society of America (2001); School of Earth Sciences Teaching Award (1990); GES Undergraduate Program Director (2002-2012); member, Stanford University Writing and Rhetoric Governance Board (2006-2012); member, GES Graduate Admissions Committee (2005-06)
