This award provides $300,000 in total funding over 24 months to acquire two gas-source isotope ratio mass spectrometers (IRMS) systems for the Stable Isotope Research Facility (SIRF). The instruments will replace current failing ones. The instruments will be used for petrology and ore genesis, geomicrobiology, planetary processes, water-rock interaction, environmental assessment, atmospheric science and archaeology. The instrumentation will support faculty from Chemistry, Biology, Geography/Atmospheric Sciences, Archaeology and the School of Public and Environmental Affairs in addition to the Department of Geological Sciences which manages the SIRF. In addition, outsider users (~ 80 in the past three years) have utilized the facility. An instrument capable of four ion beams simultaneous measurement is requested for SF6 analysis. A more standard instrument is requested which will be used for oxygen, carbon, and nitrogen isotope analysis. The SIRF has users both at Indiana University and outside institutions. Student use is also high. The SIRF provides hands-on training for students. Training includes sample prep and instrument operation. The PI and co-PI have managed the SIRF for more than 20 years. Both Pis have a strong background in advising underrepresented graduate students. The instruments will be housed in the existing SIRF space. The facility has two full-time technical researchers. Technician salary, supplies and maintenance come from grant support and external user fees.
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using funds from this award, and contributions from Indiana University. The instruments were purchased from the Thermo-Fisher Scientific Company. One is a Delta-V which is utilized for sulfur isotope ratio determinations using sulfur dioxide; the instrument is also capable of measuring oxygen isotope ratios using carbon dioxide. The second instrument is a MAT 253 with capabilities of measuring sulfur hexafluoride, as well as sulfur dioxide and carbon dioxide. The new Delta V and MAT 253 mass spectrometers have been in use since their installations in August of 2011 and April of 2012, respectively. More than 1000 sulfur isotope measurements have been completed in the past year. In addition to sulfur isotopes, oxygen isotope ratios have also been measured for a variety of samples using the MAT 253. Photographs of the instruments are included with this report. Sulfur and oxygen isotope ratio measurements are used in a variety of studies in geological and environmental science. Stable isotope data at Indiana University are applied to studies of metallic ore genesis, particularly nickel, copper, gold and platinum-group elements. Studies of the origin of fossil fuels such as petroleum and coal also utilize stable isotope data to help track how organic matter transforms to fuels. Isotopic data provide key information on past climates and how climatic change has impacted landscapes. Several studies are also in progress that rely on isotope measurements to better constrain how organic-rich wetlands help to alleviate problems with the generation of acidic waters that emanate from coal mines. Our new instruments are part of a regional and international outreach program where state-of-the-art instruments are made available to researchers outside of Indiana University. Isotope measurements have been made in collaboration with scientists from several US institutions, including Iowa State University, Southern Illinois University, the University of Notre Dame, the University of Missouri and the University of Tennessee. We also have collaborative projects with researchers from around the globe, including, Canada, Australia, China, Finland, India, Russia, Greece, Poland, and Turkey. Stable isotope data are crucial in many different disciplines and application will increase in the future. The SIRF at Indiana University is a premier site for the generation of world-class isotopic data; we gratefully acknowledge the support of the National Science Foundation in maintaining our ability to serve the worldwide scientific community.
