Acquisition of an SEM with quantitative X-ray detectors to research Geology-Climate-Biology connections

Southern Methodist University, Dallas TX

Investigators

Abstract

The award will permit the acquisition of a new Scanning Electron Microscope with X-ray detectors that will facilitate and accelerate research into relationships among geology, climate and biology in the rock record, at anthropologic sites and in areas of active chemical remediation. It will be used to investigate chemical variations at the micro-scale. Geological applications include studying large historic and prehistoric volcanic eruptions that emit sulfur that causes global cooling over multiple years. We will also analyze fossils to investigate ancient life at the cellular level. Environmental engineering applications include using synthetically produced materials and induced mineral growth to remove toxic metals from water. Anthropology applications include investigating the relationship between humans and the landscape by learning from charcoals what were the critical sources of fuel for cooking fires, and also how fires in the landscape impacted these peoples. Volcanic hazard assessment, water contamination remediation and understanding the relationship between the environment and native pasts and cultures all have clear positive impacts on national interests. These are only a few examples of many future research projects to be realized through the new Scanning Electron Microscope. This instrument will promote the progress of currently NSF funded research in Geobiology and Low Temperature Geochemistry, Sedimentary Geology and Paleobiology, Dynamics of Coupled Natural and Human Systems, Earth-Life Transitions, in addition to NSF Archaeology, Office of Polar Programs, the Research Experiences for Undergraduates program and Engineering and Education Centers. The instrument to be purchased is a tungsten filament Scanning Electron Microscope (SEM), which will be outfitted with energy dispersive (EDS) and wavelength dispersive (WDS) quantitative geochemical detectors and a 3 color cathodoluminescence detector. This instrument will be a unique and regional resource. It will support cutting-edge, fundamental research into geology-climate-biology connections and other science and engineering projects. The improved beam density at lower voltages of modern SEM instruments allows for micro-geochemical applications (EDS/WDS) at high spatial resolutions. The proposed SEM can achieve a resolution of 3-4 nm, allowing imaging of microscopic fossil cellular features on the order of 100-500 nm and can definitively identify taxon sources of sedimentary and anthropogenic charcoals. SMU has a long history of running successful, productive electron beam and X-ray instrumentation. The acquisition of the proposed SEM with X-ray detection will make SMU a regional hub for these technologies. This will lead to numerous research education opportunities. 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.