9725239 Spetzler The elastic properties of single crystal olivine samples with different Fe contents will be measured in a simultaneous high P and high T environment to 5 GPa and 1, 000 K. The new data will provide knowledge of the elastic anisotropy as functions of composition at P-T conditions appropriate for interpreting the seismic anisotropy of Earth's upper mantle. The data will be the first to accurately address the issue of how much olivine is needed or how thick the anisotropy zone in the upper mantle is in order to explain the observed seismic anisotropy. The new data will also yield information on the bulk properties of olivine as a function of its Fe content and the cross pressure and temperature effect on the elasticity of this mantle silicate. These data will be used to establish better mineralogical models to interpret the seismic velocity variation at depths of the upper mantle, taking into account the petrological observations of the varying Fe contents of olivine samples originating from the upper mantle.
