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| Stable Isotope Biogeochemistry | ||||
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Fike Vitae Publications Research Projects Lab Group Classes Facilities |
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David Fike
Phone: (314) 935-6607 |
| Overview | ||||
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Stable Isotope Biogeochemistry involves the use of the stable isotopic compositions of elements that make up minerals and organic matter to understand and/or reconstruct biological activity. Typically, carbon (&delta13C), nitrogen (&delta15N) or sulfur (&delta34S - or, more recently, &Delta33S/&Delta36S) isotopes are analyzed, with the results linked to the activity of certain metabolic pathways and the presence of specific phylogenies. In the modern, stable isotope biogeochemistry is used to understand biological cycling within microbially-dominanted environments (e.g., microbial mats, or marine sediments), reconstruct larger-scale ecosystem dynamics and food webs, and trace the development of human agriculture (e.g., the spread of maize domestication). On a global-scale, these isotopes provide the best estimate for global biolgoical productivity as well as the burial of both reduced carbon (organic matter) and sulfur (pyrite), which are the two dominant factors that regulate atmospheric oxygen levels (pO2). Isotope studies of carbon and sulfur throughout Earth history provide one of the most powerful tools for reconstructing environmental change throughout Earth history, particularly the accumulations of oxygen in the ocean-atmosphere system during the Paleoproterozoic (~2.2-2.5 billion years ago) and the late Neoproterozoic (~635 - 541 million years ago). Here at WashU, we focus on both modern systems and using the geologic record to reconstruct changes throughout Earth history. Several ongoing projects are described here. We are always looking for new ideas, so feel free to contact us to talk about possible new projects and future collaborations. |
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Updated 11/15/09 |