This grant supports acquisition of the following pieces of equipment to be added to the Oxy-Anion Stable Isotope Consortium (OASIC) at Louisiana State University (LSU): (1) An isotope-ratio mass spectrometer (IRMS); (2) optical replacement parts for an existing CO2-laser system; (3) A CRDS water isotope analyzer; (4) A thermogravimetric analyzer (TGA); and (5) a Gas Chromatograph (GC). The IRMS will be used mainly for ä34S measurement of sulfate and sulfide samples. The optical parts are replacing a clouded window. The CRDS, TGA, and GC are three critically missing pieces of equipment in the laboratory. Over the years, PI and his students have developed new wet chemistry methods and new extraction techniques that have opened up several research frontiers, including (1) Sulfate non-mass-dependent (NMD) depletion of the isotope 17O in the immediate aftermath of the global Marinoan glaciation at ~635 million years ago (funded by NSF Geobiology & Low-Temperature Geochemistry and NASA Astrobiology); (2) Sulfate NMD enrichment of the isotope 17O in volcanic ash beds in Cenozoic North America (funded by NSF Petrology & Geochemistry); (3) The discovery of NMD enrichment of the isotope 17O in natural perchlorate; and (4) NMD behaviors for rarefied gases (O2 and SF6) under a thermal gradient. Recently, OASIC?s capacity has been increasingly constrained due to equipment aging and lack of some of the essential instruments. The requested addition will allow the PI and graduate students to expand and test several new ideas in (1) non-mass-dependent stable isotope geochemistry, (2) isotope fractionation kinetics (e.g. incorporation and elimination or O2 signal in sulfate), and (3) mineral-gas oxygen isotope behaviors related to material and energy sciences, a new campus-wide LSU initiative. The upgrade will (1) enhance hands-on and interdisciplinary training of culturally and ethnically diverse postdoctoral researchers, graduate and undergraduate students, through supervised installation, self-maintenance, operation, and repair, and through collaboration with researchers around the world; (2) fill in a critical infrastructure need at the interface of geology, material science & engineering, and coastal studies within LSU research community; and (3) establish LSU OASIC as the go-to place for a leading-edge stable isotope laboratory in the South.
