Low Versus High Latitude Continental Climatic Effects of the Central Atlantic Magmatic Province on the End Triassic Extinction Event

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This project aims to understand the end Triassic extinction (ETE about 201 Million years ago), one of five mass extinctions in Earth's history. The causes of the ETE are still under investigation, but massive volcanic eruptions during the breakup of Pangea emitted large amounts of greenhouse gases, which in turn caused habitat-change. As a result, many animal and plant species went extinct, allowing for new animals to thrive, notably dinosaurs. The project focuses on two field locations: the Moenave Formation of Utah, near the sub-tropics during the time of extinction, and the Elliot Formation of South Africa and Lesotho, near the South Pole. By combining the timescale with the occurrence of fossils, a prediction of how major climatic changes may cause extinction will be developed, thus providing us with clues about how to mitigate the current increased levels of species extinctions. The proposed study has important societal implications. It addresses some of the grand challenges for research on Earth-surface processes, published by the National Academy of Sciences (Landscapes on the Edge: New Horizons for Research on Earth's Surface). For example, the research will help identify how knowledge of our planet's past helps us prepare for a sustainable future. Students supported by this project will be recruited from two major organizations that encourage scientific education for minorities: the Society for Chicanos and Native Americans in Science and the National Association of Black Geoscientists. The project will involve federal agencies through partnerships with the St. George Dinosaur Discovery Museum and Zion National Park, specifically via museum and visitor center displays of our study outcomes. Student exchange experience will be coordinated with Senior Personnel at the University of Cape Town (UCT) and University of the Witwatersrand (UW). Students from the University of Arkansas (UA) will spend a field season in southern Africa learning field skills and gaining cultural experiences, and students from UCT and UW will visit the UA to learn geochemical and spectrometry skills and visit field sites. Finally, we will develop datasets for and work with high school teachers that are training for the Next Generation Science Standards adopted by the state of Arkansas.The project will: 1) identify the ETE in the Moenave Formation, USA (low-latitude) and the Elliot Formation of southern Africa (high-latitude) using bio- and chemostratigraphy and high resolution geochronology; 2) generate paleoclimate proxy data; 3) determine biostratigraphic trends in ichnological and microfaunal record; and 4) compare ecosystem and climatic shifts in high versus low-latitudes in the southern hemisphere. The methods employed include: 1) collection of C-isotope (bulk and compound-specific) chemostratigraphic and detrital zircon geochronologic data from both formations; and 2) biostratigraphic data (body and trace fossils of vertebrates and invertebrates). CO2 concentration, temperature, and mean annual precipitation will be calculated using stable and clumped isotopes from paleosol and lacustrine sediments, major and minor element concentrations from paleosols, and O-isotopes from ostracods and vertebrate fossils. These data will then be correlated to the paleontological occurrences of vertebrate and invertebrate remains from both continents to determine effects of climate change caused by the CAMP on the two ecosystems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.