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

[09:30034 . hirschmann]该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。地球深处的波动周期对我们的星球有根本的影响？地球动力学、岩浆作用、大气、气候和宜居性。由于C-H-O挥发物（包括H2O、CO2和CH4）对黏性、扩散性、弹性和电导率等输运性质的影响，对地幔的对流动力学及其可观测的地球物理性质有着深远的影响。这笔拨款用于购买一台新的微型ftir光谱仪，这是研究溶解在矿物和淬火熔体中的C-H-O挥发物浓度的关键工具。新的光谱仪将主要用于分析来自高压实验的样品，这些实验研究挥发物对与挥发物在地球深部循环有关的地球深部物质的化学和物理性质的作用。具体研究项目包括：(1)名义上无水矿物与硅酸盐熔体之间H的分配；(2)为提高SIMS、FTIR和EPMA的精度，以及矿物和熔体中H2O的分析，对标准进行相互校准；(3)名义无水矿物中OH的低温FTIR研究；(4)研究水对上地幔和过渡带地震不连续面的影响；(5)研究H2O和CO2对橄榄岩小度部分熔融的影响及低速带（LVZ）的成因；(6)研究C-O-H组分（CO2、CH4）在地幔熔融中的作用和深部行星挥发循环的作用；(7)量化上地幔矿物的水弱化作用；(8) H2O对橄榄石中离子扩散的影响。PI参与NSF资助的本科生研究经验（REU）网站将促进学生的培训和参与现代材料表征方法。

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.