Si and O self-diffusion in hydrous forsterite and iron-bearing olivine from the perspective of defect chemistry

摘要: We discuss the experimental results of silicon and oxygen self-diffusion coefficients in forsterite iron-bearing olivine from perspective defect chemistry. Silicon diffusion is dominated by VO ··-associated VSi″″, whereas hopping ·· under anhydrous conditions, (OH)O · hydrous conditions. By considering charge neutrality condition [(OH)O ·] = 2[VMe″] olivine, we get D Si ∝ (\(C_{{{\text{H}}_{2} {\text{O}}}}\))1/3 O {\text{O}}}}\))0, which explains water effects on rates (Fei et al. Nature 498:213–215, 2013; J Geophys Res 119:7598–7606, 2014). The \(C_{{{\text{H}}_{2} {\text{O}}}}\) dependence creep rate Earth’s mantle should be close to that given obtained unsaturated