9725461 Stolper The goals of this project are: (1) refining a new experimental approach for determining the partial molar volumes of oxide components in silicate liquids as a function of P and T; (2) applying this approach to determine the partial molar volumes of SiO2, Al2O3, TiO2 and Fe2O3 in silicate liquids at mantle pressures; (3) determining the 1 bar activities of SiO2, Al2O3 and TiO2 in silicate liquid compositions corresponding to those produced in the PIs elevated pressure experiments using the Pd-oxide equilibration technique and the 1 bar activity of Fe2O3 using Pt-oxide equilibration; and (4) possibly identifying pressure-induced coordination changes for SiO2, Al2O3, TiO2, and Fe2O3 in silicate liquids at mantle conditions. The data to be collected will provide an important complement to 1 bar determinations of partial molar volumes and compressibilities. The 1 bar activity determinations for SiO2, Al2O3, and TiO2 and Fe2O3 will provide data that can be used to (1) improve the accuracy of our partial molar volume determinations, and (2) improve the calibration of solution models for silicate liquids.
