ACQUISITION OF A NEW MICROFTIR SPECTROMETER TO AID EXPERIMENTAL AND ANALYTICAL STUDIES OF C-H-O VOLATILES IN THE MANTLE

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0930034HirschmannThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Deep Earth volatile cycles have a fundamental influence on our planet?s geodynamics, magmatism, atmosphere, climate, and habitability. Owing to their influence on transport properties such as viscosity, diffusivity, elasticity, and conductivity, C-H-O volatiles (including H2O, CO2, and CH4 species) have profound influence on the convective dynamics of the mantle and on its observable geophysical properties. This grant funds purchase of a new micro-FTIR spectrometer, which is a key tool for studying the concentrations of C-H-O volatiles dissolved in minerals and quenched melts. The new spectrometer will be employed principally for analyses of samples from high pressure experiments that investigate the role of volatiles on the chemical and physical properties of deep Earth materials related to cycling of volatiles in the deep Earth. Specific research projects include: (1) Partitioning of H between nominally anhydrous minerals and silicate melts; (2) Intercalibration of standards for improved accuracy of SIMS, FTIR, and EPMA, analyses of H2O in minerals and melts; (3) Low temperature FTIR investigations of OH in nominally anhydrous minerals; (4) Investigating the influence of H2O on upper mantle and transition zone seismic discontinuities; (5) Investigating the influence of H2O and CO2 on small-degree partial melting of peridotite and the origin of the Low Velocity Zone (LVZ); (6) Investigating the role of C-O-H species (CO2, CH4) on mantle melting and the role of deep planetary volatile cycles; (7) Quantifying water weakening of upper-mantle minerals; and (8) Influence of H2O on ionic diffusion in olivine. PI involvement in an NSF funded Research Experience for Undergraduates (REU) Site will facilitate student training and involvement in modern methods of materials characterization.