Facility Support: The WiscSIMS National Ion Microprobe

点击翻译按钮获取中文摘要

This grant provides support of the WiscSIMS Laboratory at the University of Wisconsin - Madison. WiscSIMS is a National Facility for Stable Isotope Geochemistry and provides unique analytical capabilities for 20-30 guest scientists each year from outside of the University of Wisconsin System. A wide range of Earth Science research is conducted at WiscSIMS. Thus far, over 380 scientists have worked with WiscSIMS from 65 different universities and research institutes. The ability to analyze small spots (1-10 micron) in situ from microscope mounts allows data to be put in context with imaging and other forms of analysis. WiscSIMS will continue to make 50% of total beam-time available each year to researchers from outside of the University of Wisconsin. The broader impacts of this project include new applications of stable isotope geochemistry to problems of societal concern; public education; and SIMS/geochemistry training at undergraduate to post-doc level, including under-represented groups. Since 2008, 115 students, including 55 women and 5 minorities, used WiscSIMS in their thesis research.WiscSIMS has optimized an IMS-1280 large-radius, multi-collector ion microprobe for analysis of stable isotopes (including Li, C, N, O, Mg, Si, S, Ca, and Fe). The three most common areas of research are Igneous and Metamorphic Petrology & Geochemistry; Cosmochemistry & Astrobiology; and Low Temperature Geochemistry & Paleoclimatology. Applications of the new in situ capabilities are potentially transformative in many areas of geochemistry. The range and pattern of isotope variation can finally be determined from small objects that were formerly homogenized by analysis of bulk or powdered samples such as zircons, microfossils, quartz overgrowths, and carbonates. New and surprising information of fundamental importance has been found in a large number of studies. For instance, high-resolution carbonate studies of continental paleoclimate were formerly limited to resolution at decade-to century-scale by conventional sampling techniques and yet ice-core records show that extreme shifts in deglaciation can occur in less than 10 years. Ion microprobe analysis of stalagmites has resolved changes in oxygen isotope ratio for one month or less, providing a proxy record of seasonality and annual-scale climate. WiscSIMS has published studies of many proxies of paleoclimate including speleothems, foraminifera, fish otoliths, mollusks, and calcretes. During the next three-year funding cycle, increased emphasis will build on these achievements to help resolve long-standing paleoclimate questions, especially in proxy records of rapid climate change where conventional techniques cannot resolve short time periods.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.