Noble gases in silicate perovskite: Solubility, dissolution mechanism and influence on the equation of state

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We have carried out some preliminary experiments suggesting significant noble gas solubility in (Mg,Al)(Si,Al)O3 perovskite, the main constituent of Earth´s lower mantle. Measured argon contents are in the 500 ppm range, but actual solubilities may be much higher, since the samples may not have been saturated with argon. If noble gases were highly soluble in perovskite, this would provide the long-sought reservoir for primitive volatiles in the deep Earth. It would also have implications for high-pressure research in general, since ultrahigh-pressure experiments are usually carried out in diamond cells using a noble gas pressure medium. The inferred solubilities are high enough to affect equations of state and the location of phase boundaries. In this project, (i) the solubilities of argon and xenon in silicate perovskite shall be systematically studied in multi-anvil and diamond anvil cell experiments (ii) the effect of argon in the perovskite on the equation of state shall be studied by in-situ X-ray diffraction (iii) the substitution mechanism of noble gases in silicate perovskite shall be investigated by ab-initio modeling.