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.