Analytical Capability

Currently, the following stable isotope analyses are well-established and routinely available to external users. The beam sizes are typically 10µm and analyses take 3-10min/spot (depending on isotope system). Mineral analysis is limited by availability of standards. Potential users should inquire about creation of other standards.

  • Oxygen isotopes (δ18O) with ~10 µm spots:
    Zircon, quartz, olivine*, pyroxene*, garnets*, titanite*, calcite*, aragonite, dolomite-ankerite*, magnesite-siderite*, plagioclase*, K-feldspar, spinel*, chromite*, epidote*, opal, coesite, silicate glass*: precision typically ~0.3‰ (2SD)
  • Carbon isotopes (δ13C) with ~8 µm spots:
    Diamond, graphite: precision typically ~0.4‰ (2SD)
    Calcite, aragonite, dolomite, ankerite, magnesite-siderite*,: precision typically ~0.7‰ (2SD)
  • Sulfur isotopes (δ34S) with ~10 µm spots:
    Pyrite, anhydrite, pyrrhotite, chalcopyrite: precision typically ~0.4‰ (2SD)
  • Si isotope (δ30Si) with ~10 µm spots:
    Quartz: precision typically ~0.2‰ (2SD)

(*: We request that users obtain EPMA data of individual spots prior to SIMS analyses for correction of matrix effect.)

An analysis with smaller beam sizes down to 2 µm is available for some systems, but analysis is slower (15-30 min/spot) and with degraded precision (~1‰). Other applications with more difficult samples, requiring new standards, or with Li isotopes (δ7Li), Mg three isotopes (δ25Mg, δ26Mg, and excess δ26Mg), oxygen three isotopes (δ18O, δ17O, and Δ17O), and sulfur three and four isotopes (δ33S, δ34S, δ36S, Δ33S, and Δ36S) may also be available. Please contact us for more detailed information.

Note that some samples show an orientation effect and can only be analyzed for isotope ratio by SIMS at reduced precision (Kita et al., 2011). WiscSIMS has detected orientation effects in magnetite, hematite, baddeleyite, rutile, galena, and sphalerite.