Facility Support: The Wisc-SIMS National Ion Microprobe

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

This award will provide support for WiscSIMS, the Wisconsin Secondary-Ion Mass-Spectrometer National Ion Microprobe Facility. This laboratory houses the first, new-generation, CAMECA ims-1280 ion microprobe and is rapidly expanding its leadership role as a center of excellence for stable isotope geochemistry. The PI's will initiate investigations combining a variety of isotope systems including: H, Li, B, C, N, O, Mg, Si, S, Cl, Ca, and Fe. They are actively seeking and developing fundamental new applications in many disciplines. The scientific design of projects, and the development of standards and analysis protocols, benefits from close association to three other isotope laboratories in the Department of Geology & Geophysics, where WiscSIMS is located. WiscSIMS takes advantage of new multicollector technology and other advances of the 1280 instrument to focus on the specialized needs of stable isotope geochemistry: high precision, small sample size, and in situ analysis. The ability of an ion microprobe to analyze isotope ratios from 1-10 ụm spots from a microscope slide, reduces sample sizes by a factor of ten thousand to one billion, and allows analyses to be placed in context with textures and other imaging. Excellent analytical precision, as good as 0.1%, is routinely attained for many isotope systems, which reveal trends and correlations that were not previously seen in earlier studies. These advantages are revolutionizing isotope geochemistry, just as the electron microprobe revolutionized in situ chemical analysis and the SHRIMP (ion microprobe) revolutionized zircon geochronology.