CAREER: Understanding how Earth's coupled carbon and sulfur cycles evolved after the oxygenation of the atmosphere

University Of Chicago, Chicago IL

Investigators

Abstract

CAREER: Understanding how Earth's coupled carbon and sulfur cycles evolved after the oxygenation of the atmosphere PI: Clara Blättler (University of Chicago) This research will improve understanding of Earth’s evolution as a planet following the appearance of oxygen in the atmosphere approximately 2.3 billion years ago. The project will focus on a unique set of rocks deposited during this period of time and collected by an international collaboration in 2007. By studying the sedimentary record of the carbon cycle and sulfur cycle in these rocks, this research will show how the transition to an oxygenated atmosphere impacted Earth’s interconnected geochemical cycles. Complementing these research activities, the history of Earth and its ancient environments will be promoted in K–12 education and public settings through a collaboration with the Field Museum of Natural History. A hands-on kit will be developed to introduce these scientific ideas through select rock specimens, activities, and online content, and this resource will be showcased at the Field Museum, professional development workshops for teachers, and local outreach events in Chicago. The project will test hypotheses about the magnitude and interpretation of the Great Oxidation Event and the Lomagundi-Jatuli Event in the Paleoproterozoic. The amount of organic carbon burial and the size of the seawater sulfate reservoir during this redox transition are uncertain because of inherent limitations in the geochemical record of carbonates. With a multi-proxy geochemical approach to test for diagenetic effects, authigenic minerals, and local artifacts, more robust reconstructions for global carbonate carbon-isotope ratios and sulfur-isotope ratios will be generated for the Paleoproterozoic record in Fennoscandia. These results will be used to generate revised global biogeochemical models for the evolution of Paleoproterozoic surface redox and oxygen production. To help teach about Earth’s redox evolution, hands-on Experience Boxes will be developed that will be available for circulation from the Field Museum’s Harris Learning Collection as well as used in several outreach events by the scientists working on this research. 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.