The Yorkshire Geological Society, University of Leeds and Leeds Geological Association are delighted to host Prof Jerry Dickens (Rice University, Texas in the School of Earth and Environment. Jerry has been a central figure in understanding the importance of carbon cycle dynamics in Earth history and the role carbon plays in regulating global climate over geological timescales.
Jerry's talk will investigate the utility of the vast array of existing carbon isotope records to understand their importance for stratigraphy and to delve further into understanding the history of carbon on our planet.
Abstract: Greater than five thousand stable carbon isotope records have been generated using carbonate or organic carbon components deposited during the Cenozoic. These records, generally expressed in d13C, show major changes over time and between different carbon-bearing components. New records, where the d13C compositions of multiple phases are determined across short intervals of time at the same location, highlight these aspects. Cenozoic d13C records remain crucially interesting and important. Across many time intervals, the d13C composition of multiple phases and at multiple locations shift coherently, at least on the 1000-year cycling time of carbon across Earth's surface. This has been an amazing revelation to the field of stratigraphy, and makes complete sense at a basic level, once one recognizes how carbon moves between the ocean, biosphere and atmosphere. However, the variations in d13C also raise a major problem when one considers requisite carbon masses. Almost assuredly, Earth has at least one major carbon capacitor outside conventional carbon cycle models throughout the Cenozoic and before. A deep view of "carbon isotope stratigraphy" forces one to think outside the box.