Water partitioning between nominally anhydrous minerals in the MgO–SiO2–H2O system up to 24 GPa: implications for the distribution of water in the Earth's mantle

Lower mantle hydrogen partitioning between periclase and perovskite: A quantum chemical modelling

“…On the basis of some experimental studies, Fe-free periclase seems to accommodate almost no water in its structure (Bolfan-Casanova et al, 2000; conversely, other authors (Murakami et al, 2002;Litasov and Ohtani, 2007) assign high water incorporation capability to this phase, with H 2 O-uptake ranging between 0.1 and 0.2 wt% (1000-2000 ppm). Such discrepancies might mirror the main H incorporation mechanisms in the structure of the samples, their being out of P-T thermodynamic equilibrium and/or an analytical strategy for water measurement.…”

Expanding the application of the Eu‐oxybarometer to the lherzolitic shergottites and nakhlites: Implications for the oxidation state heterogeneity of the Martian interior

“…Therefore, this cumulate package represents depleted Martian mantle, a composition comparable in incompatible element composition to terrestrial depleted mantle (i.e., the MORB source [Sun and McDonough 1989] The addition of a reasonable amount of initial water (0.05 wt%) to the Martian magma ocean does not affect the majority of the crystallization sequence perceptibly. The early crystallizing minerals are all nominally anhydrous, meaning that though they can contain petrologically significant amounts of OH (as much as 1000-1500 ppm for olivine and orthopyroxene) (Koga et al 2003;Bell et al 2004;Aubaud et al 2004;Bolfan-Casanova and Keppler 2000), the effect on the overall water content of the melt is small. It is in the late stages of crystallization that the amount of water becomes significant (Fig.…”

Thermal, hydrous, and mechanical states of the mantle transition zone beneath southern Africa

“…The water storage potential per unit mass of (Mg,Fe) 2 SiO 4 wadsleyite and ringwoodite is 2^3 wt% [36,37]. Given experimental constraints on water partitioning in the MgO^SiO 2^H2 O system [38], a pyrolitic mantle transition zone could store up to 1.3^2 wt% H 2 O. In the early Earth's mantle, the transition zone was likely to be relatively enriched in water [39].…”