NSF Award
1714898
ABSTRACT<br/><br/>A non-technical description explaining the broader significance of the project<br/><br/>Major mass extinctions have occurred at various times throughout Earth history. The most well-known of these happened with the demise of the dinosaurs at the end of the Cretaceous Period, but it is believed that the largest mass extinction happened at the end of the Permian Period, approximately 252 million years ago. The extinction in the marine realm was global and occurred over a relatively short time interval. However, events in the terrestrial environment are only sparsely documented. This project will examine well-exposed sedimentary rock successions that formed in lakes, rivers, and ancient soils during the time of these extinctions. This research will enable a precise documentation of the sequence of events on land, a comprehensive analysis of the environmental changes that took place before, during and after the event, and an investigation of how terrestrial animals and plants responded to these changes. The results will determine if extinctions on the continents occurred at the same time as those in the ocean and what conditions existed that may have caused such large-scale changes. Given current concern about rates of extinction, knowledge of the processes that occurred in the past will help identify the reasons behind major changes in flora and fauna. The project will develop museum exhibits and outreach programs to inform both educational and general audiences.<br/><br/>A technical description of the project<br/><br/>A comprehensive, multidisciplinary investigation of critical intervals of Earth history offers the best insights into the conditions that prevailed before, during, and after major biotic crises. The Permo-Triassic Mass Extinction is used as a model of how biological and physical systems responded to major climate changes, including those attributable to increasing greenhouse gases. Currently, the Permo-Triassic Mass Extinction is interpreted as a coupled catastrophic collapse of marine and terrestrial ecosystems, both of which experienced protracted restructuring of ecological communities and recovery of stable ecosystem dynamics. The Bogda Mountains in China contain a fully continental stratigraphy spanning the critical interval wherein fluvial and lacustrine deposits alternate with an extensive paleosol record, from which pedogenic trends and geochemical models can be derived. A paleontological record including major plant and animal groups is well-preserved. Pilot-project data show the preservation of a primary magnetization in rocks in the section, from which a robust magnetic polarity stratigraphy can be derived. There are also numerous volcanic deposits that contain primary volcanic zircons spanning the critical interval. These will be used to obtain high precision ages to establish a careful chronology. Together, these data allow evaluation of environmental and ecosystem changes that took place during the Permian-Triassic transition. Research results will be integrated into curricula at each participating academic institution, and summer outreach programs will be offered to high-school science teachers. Five educational videos will be developed for the Field Museum's award winning "The Brain Scoop" YouTube channel. Data visualizations of analytical and model results will be developed for informal education outreach in conjunction with the Visualization Studio at the California Academy of Sciences.
