Acquisition of an Isotope Ratio Mass Spectrometer for Clumped Isotope Analysis to Expand the Alabama Stable Isotope Laboratory

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This Division of Earth Sciences Instrumentation and Facilities Program grant supports acquisition of an isotope ratio mass spectrometer (IRMS) at the University of Alabama to facilitate faculty, student and regional collaborative research with a focus on deciphering Earth?s climate and water body temperature conditions across notable mass extinction boundaries in Earth?s history. The instrument to be acquired is specialized for the analysis technique of clumped isotope paleothermometry, and while relatively new has been shown to prove useful for independently estimating the temperature of formation of carbonates in the ancient sedimentary, rock and fossil records. The instrument would be first-of-its kind in the SE U.S., with the exception of south Florida and benefit researchers across the states of Alabama, Georgia, Mississippi, Louisiana, Arkansas, Tennessee, and North and South Carolina. The investigators intend to engage graduate and undergraduate students in experiential learning using the new instrument and will work with a local HBCU, Fort Valley State University, in a cross-university collaboration to facilitate the recruitment of underrepresented students to the geosciences.The IRMS to be acquired will be capable of making routine ?clumped? isotope ratio measurements of the double substituted isotopologue 13C16O18O or mass 47 clump, which is a measure of the enrichment of the number of CO2 molecules containing a 13C-18O bond above the number expected by a random distribution of carbon and oxygen isotopes. Clumped isotopic analysis can be used to independently infer the temperature of formation of carbonates at the time they were precipitated (paleothermometry) without any assumptions about the oxygen isotopic composition of the water from which they precipitated. Clumped isotope paleothermometry is a relatively new technique which has been primarily employed in the analysis of ancient carbonate material from multiple sources, including shallow diagenetic fluids, dolomitization, soil carbonates, speleothems, methane seeps, and a variety of biogenic carbonates (e.g., bivalves and corals). As the technique is relatively new there is still active development work being conducted on standardization techniques and inter-laboratory comparisons are being made. Research applications will include, but are not limited to, studies of the effects of climate on the proliferation of human civilization and how different food sources were utilized and prepared by indigenous populations; paleontological investigations of the growth rates of extinct organisms; paleoclimate changes across mass extinction boundaries; and studies of the importance of diagenesis in Precambrian carbonates.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.