Water Transport into the Deep Mantle by Hydrous Phases

Abstract

Water content in the Earth's deep interior is still controversial. In this article, recent experimental studies on hydrous phases, which play an important role in the transportation of water into the deep mantle, were reviewed. In-situ X-ray diffraction measurements combined with multi-anvil apparatus and laser-heated diamond anvil cell techniques clarified phase transitions and solid solutions of hydrous phases over a wide composition range in the ternary MgSiO₄H₂-AlOOH-FeOOH system under pressures. Based on these results, deep water transportation to the deep lower mantle are discussed.