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In situ X‐ray observation of decomposition of superhydrous phase B at high pressure and temperature
Author(s) -
Ohtani Eiji,
Toma Motomasa,
Kubo Tomoaki,
Kondo Tadashi,
Kikegawa Takumi
Publication year - 2003
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2002gl015549
Subject(s) - periclase , decomposition , in situ , diffraction , phase (matter) , mantle (geology) , materials science , geology , high pressure , phase boundary , mineralogy , analytical chemistry (journal) , thermodynamics , chemistry , geochemistry , optics , physics , metallurgy , organic chemistry , chromatography , magnesium
High pressure and high temperature in situ X‐ray diffraction experiments on the stability of superhydrous phase B have been conducted to clarify the host of water in the slabs descending into the lower mantle. We observed the decomposition reaction of superhydrous phase B into phase G (= phase D and F), periclase, and MgSiO 3 perovskite at around 700 ∼1100°C and above 30 GPa, and the boundary of the decomposition reaction can be expressed as P(GPa) = −0.0037(±0.0017)T(°C) + 32.2(±0.5). This reaction can occur in slabs descending into the uppermost part of the lower mantle.