Arthur L. Day Medal: Opportunity at the Nexus of Sedimentary Geology—Geochemistry—Earth System Science

The field of sedimentary geology underwent a revolution toward the close of the 20th century with integration of low-temperature geo- and bio-geochemistry, Earth System (climate) modeling, and Earth system science approaches into sedimentologic, stratigraphic, and paleobiologic studies. My career launched during this ‘revolution’ starting with a focus on diagenesis. Extensive collaborations over the subsequent decades with inorganic and organic geochemists, geochronologists, paleobiologists and terrestrial ecologists, and climate and ecosystem modelers have permitted me to explore many new avenues at this research nexus. In this talk, I’ll discuss how the coupling of field, laboratory, and modeling efforts by the sedimentary geology and geochemistry community has led to the development and calibration of novel geo- and bio-geochemical proxies of Earth system conditions. In turn, their application to sedimentary successions has permitted reconstruction of past climate, oceanographic, and ecologic conditions throughout the Phanerozoic. The advent of high-precision geochronology in the past two decades, applied to sedimentary basins worldwide, now permits building of chronostratigraphic frameworks for analysis of contemporaneous and diverse proxy time series across the latitudes at increasingly higher resolution. Coupled with modeling, these advances enable researchers to interrogate physical, chemical, and biologic processes and their interactions and teleconnections at an unprecedented level. Today it is possible to reconstruct deep-time Earth systems that not only reveal new and often counter-intuitive information about the past, but also inform our future in a world already characterized by CO2 concentrations comparable to deep time intervals of Earth history.