Solubility of Hydrogen in Al-bearing Silicate Perovskites

Carnegie Institution Of Washington, Washington DC

Investigators

Abstract

This work will study how water is stored and distributed in the lower mantle. Experiments will be performed to understand the solubility of hydrogen in aluminous perovskites, the effect of pressure on the hydroxyl bands, and the effect of water on phase transformations at the 660-km seismic velocity discontinuity. These data are critically important for understanding substitution mechanisms for the incorporation of trivalent ions and hydrogen in the perovskite structure, and the defect chemistry in the lower mantle that controls the mantle processes. The proposed research is an integral part of the PI's continuous efforts to understand the chemistry and mineralogy of the lower mantle through experimentation and thermodynamic modeling. The project will provide opportunities for graduate students (as pre-doctoral fellows) to gain research experience. The large single crystals of silicate perovskites synthesized in this project will be available for other researchers in the community. Results from the proposed study will be disseminated primarily through publications in scientific journals, and by participation at scientific conferences. The expected results will have broad impact in many different fields including petrology, mineral physics, geochemistry, seismology and geodynamics.