Towards a robust temporal framework for Paleoproterozoic carbon isotope excursions - Annie Bauer

Towards a robust temporal framework for Paleoproterozoic carbon isotope excursions
- Annie Bauer
University of Wisconsin–Madison

The initial rise of atmospheric oxygen and ensuing fluctuations may have profound implications for the trajectory of biological evolution and global nutrient cycling. We are working to improve our understanding of the trajectory of atmospheric oxygen during the ~2.3-2.0 Ga Lomagundi-Jatuli (LJ) positive carbonate carbon isotope (δ13Ccarb) excursion and associated negative organic carbon isotope excursion in the Francevillian Basin, Gabon, and the Onega Basin, Russia. A more accurate temporal framework is necessary to understand if atmospheric oxygenation and marine carbon cycle disturbances are coupled in this interval. Our integrated petrographic, geochemical, and geochronological characterization of these rocks is a key step toward more rigorously assessing global correlations in this interval and will result in novel insights into the rise of oxidative weathering and global carbon cycling at the termination of what may have been the most dramatic disturbance to the carbon cycle in Earth history.