Research Areas: Paleoecology

1. Aqueous Geochemistry
2. Environmental and Theoretical Geochemistry
3. Mineral Physics and Petrology
4. Paleoecology
5. Paleoclimatology and Paleoceanography
6. Planetary Science    
7. Sedimentology and Stratigraphy
8. Seismology
9. Space Geodesy
10. Tectonics and Structural Geology

Brad Sageman is interested in the paleobiologic consequences of perturbations in the global carbon cycle, such as episodes of widespread organic carbon burial and associated oxygen deficiency (e.g., Cretaceous Oceanic Anoxic Events or the Frasnian-Famennian Kellwasser events). Conversely, he is also interested in the role that organisms play in modulating or driving changes in global biogeochemical cycles and associated climates. Sageman has an ongoing project with colleague Dr. Carlton Breet of the relationship between organic carbon burial processes and changes in community structure in the Devonian Appalachian basin. In addition, a recent collaboration with paleobotanist Jenny McElwain at University College Dublin is expanding prior work on the molluscan faunas of the Cenomanian-Turonian interval in the Western Interior basin to coeval marginal marine floras - a fascinating comparison since the C-T marine "extinction" was coincident with a major terrestrial floral revolution in which the angiosperms replaced many previously dominant clades.

Francesca Smith's research focuses on developing and applying new isotopic proxies for reconstructing vegetation and carbon cycling in terrestrial ecosystems in the geologic past. Her approach to proxy development involves characterizing isotope systems in modern environments, and employing fieldand greenhouse studies of living plants. She is particularly interested in isotopic signatures of individual organic compounds that can be identified by their structure as biomarkers for particular source organisms, such as bacteria, archaea, fungi, algae and vascular plant. Smith’s research focuses on compound-specific isotope measurements of leaf wax lipids as a means of reconstructing carbon isotope discrimination by plants. Specifically, she is examining changes in discrimination due to climatic and plant community changes during the Paleocene-Eocene Thermal Maximum. She has also been a pioneer in the development of carbon isotope ratios of grass microfossils (phytoliths) for reconstructing the proportion of C₃ and C₄ grasses in grassland ecosystems and has applied this technique to understanding the late Neogene expansion of C₄ grasses in the Great Plains.