Funds from this Major Research Instrumentation (MRI) Program grant will support acquisition of a multicollector inductively-coupled plasma mass spectrometer (MC-ICP-MS) and laser ablation (LA) microprobe at the Carnegie Institution of Washington (CIW). The instrument will augment and ultimately supplant two existing first generation MC-ICP-MS instruments purchased 10 years ago with support from the NSF-MRI-EAR program. These instruments are no longer supported by the manufacturer. A state-of-the-art MC-ICP-MS and a 193 nm LA microprobe will allow for substantial improvements in mass detection sensitivity, mass fractionation stability, detector accuracy, reliability, and ease of use compared to existing first generation instruments at CIW. A new LA-MC-ICP-MS would support a range of research in cosmo- and geochemistry requiring microspatially resolved high precision analyses of isotope ratios of alkali metals, transition metals, Platinum group (PGE) and rare earth elements. The MC-ICP-MS will also allow for continuation of the Carnegie isotope geochemistry postdoctoral program using the latest plasma mass spectrometry techniques. Specific research areas that will be fostered with the new instrument will include investigations of: 1) the degree of chemical and isotopic heterogeneity in the early solar nebula and its influence on the bulk composition of the terrestrial planets; 2) the timing of metal-silicate fractionation on planetesimals and the degree of metal-silicate equilibrium during formation of Earth?s core; 3) Re-Os isotopic and PGE abundance variations as recorders of the history and processes of mantle differentiation in relation to continent formation; and 4) processes that create compositional heterogeneity in the mantle.
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