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Melting behavior of (Mg,Fe)O solid solutions at high pressure
Author(s) -
Zhang Li,
Fei Yingwei
Publication year - 2008
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 - 10.1029/2008gl034585
Subject(s) - solidus , diamond anvil cell , mantle (geology) , thermodynamics , silicate , geothermal gradient , melting temperature , mineralogy , materials science , solid solution , partial melting , geodynamics , melting curve analysis , thermal , geology , high pressure , analytical chemistry (journal) , geophysics , chemistry , metallurgy , composite material , physics , polymerase chain reaction , paleontology , biochemistry , tectonics , organic chemistry , alloy , chromatography , gene
High pressure melting of (Mg,Fe)O ferropericlase, the second most abundant mineral in the Earth's lower mantle, is of fundamental importance for understanding the chemical differentiation, geodynamics and thermal evolution of the Earth's interior. We report the first systematic experimental study of melting behavior in the MgO‐FeO system up to 3600 K and 7 GPa, indicating the ideal solution between solid and liquid (Mg,Fe)O in the MgO‐rich portion. The zero pressure melting slope of MgO is ∼221 K/GPa derived from our resistance heating measurements, which is several times higher than the value from the previous measurements in a CO 2 ‐laser heated diamond anvil cell, but consistent with the theoretically predicted melting curves. Our results combined with the previous first‐principles simulations suggest that the melting temperature of MgO‐rich (Mg,Fe)O is significantly higher than the geotherm through the lower mantle and this would place an upper bound on the solidus of the lower mantle.