MRI: Acquisition of a Thermal Ionization Mass Spectrometer for High-Precision Geochronology and Isotope Geology

点击翻译按钮获取中文摘要

Determining the rates of geologic processes over thousand to billion year time scales requires the determination of isotopic ratios with very high precision on a wide range of Earth materials. Precise and accurate measurements of radioactive and radiogenic isotopes provides the basis for geochronology, which in addition to other types of isotopic data, can be used to unravel ties between causation versus coincidence in events such as mass extinctions, climate change, the pace of biotic evolution, and provide a more detailed understanding of the physics of mass and heat transfer that drive plate tectonics and volcanic eruptions. This MRI grant provides funds to purchase a thermal ionization mass spectrometer (TIMS) in the Department of Geosciences at Princeton University, which focuses on measuring high-precision isotope ratios that are essential for determining the age of Earth materials and understanding the rates of geologic processes. This new instrument will supplement an existing TIMS managed by PI Schoene. The enhanced capacity provided by the new TIMS will permit the lab to broaden its research focus and secure ties between the research programs of Schoene and co-PI Higgins, as well as other faculty in the department and within a broad geoscience community. The new TIMS will serve to 1) increase the capacity of a world-class U-Pb lab to host and train internal and external users from a broad spectrum of universities, including liberal arts colleges, 2) devote more time to exploring and exploiting new isotopic systems, 3) further increase the precision and accuracy of these techniques to benefit the geochronologic and isotope geology communities, 4) expand the devotion of Schoene and Higgins towards integrating research and class work, and 5) build on existing programs led by Higgins to engage and educate local urban communities in the dangers of, and science behind, environmental and anthropogenic Pb contamination. This MRI grant provides funds to purchase a new TIMS in the Department of Geosciences at Princeton University to be managed by PI Schoene and co-PI Higgins, which will supplement an existing TIMS currently managed by Schoene. The new instrument will be housed in an existing space adjacent to state-of-the-art geochemistry facilities, be supported by existing clean labs for sample preparation, and also supplement the research capabilities of existing ICPMS facilities led by Higgins. The existing TIMS and ICPMS facilities have developed a track record of serving the demand for geochronologic and isotopic data within a broad geoscience community; they also devote substantial time to establishing techniques and workflows that both ensure the precision and accuracy of routine methods and enable new science. The focus of the current TIMS is on the numerous applications of U-Pb geochronology; the new instrument will expand those capabilities and also devote time to measuring stable and radiogenic Sr and Ca isotopes. The new instrument will also permit the PIs to host more external users, thus broadening the impact of the laboratories and providing much-needed high-precision geochronologic and isotopic data to a wide-range of users from Universities that may not have the infrastructure to host similar laboratories. Targeted Geoscience research projects range from understanding the evolution of continents and volcanic systems, calibrating rates of climate change in the deep past through geochronology of stratigraphic sections, extending the reach of ice-core records for tracking atmospheric composition beyond a million years ago, measuring the flux of flood basalt eruptions and understanding their environmental impact, and increasing the precision and accuracy of geochronology of Lunar samples.