@article{PAR00013858,
  title = {{T}hermodynamics of the {M}g{O}-{F}e{O}-{S}i{O}2 system up to 140{GP}a : application to the crystallization of {E}arth's magma ocean},
  author = {{B}oukare, {C}. {E}. and {R}icard, {Y}. and {F}iquet, {G}uillaume},
  editor = {},
  language = {{ENG}},
  abstract = {{A}t the end of {E}arth's accretion and after the core-mantle segregation, the existence of a basal magma ocean at the top of the core-mantle boundary ({CMB}) depends on the physical properties of mantle materials at relevant pressure and temperature. {P}resent-day deep mantle structures such as ultralow-velocity zones and low-shear velocity provinces might be directly linked to the still ongoing crystallization of a primordial magma ocean. {W}e provide the first steps toward a self-consistent thermodynamic model of magma ocean crystallization at high pressure. {W}e build a solid-liquid thermodynamic database for silicates in the {M}g{O}-{F}e{O}-{S}i{O}2 system from 20{GP}a to 140{GP}a. {W}e use already published chemical potentials for solids, liquid {M}g{O}, and {S}i{O}2. {W}e derive standard state chemical potential for liquid {F}e{O} and mixing relations from various indirect observations. {U}sing this database, we compute the ternary phase diagram in the {M}g{O}-{F}e{O}-{S}i{O}2 system as a function of temperature and pressure. {W}e confirm that the melt is lighter than the solid of same composition for all mantle conditions but at thermodynamic equilibrium, the iron-rich liquid is denser than the solid in the deep mantle. {W}e compute a whole fractional crystallization sequence of the mantle and show that an iron-rich and fusible layer should be left above the {CMB} at the end of the crystallization.},
  keywords = {lower mantle ; melting ; {M}g{O}-{F}e{O}-{S}i{O}2 ; magma ocean ; phase equilibria},
  booktitle = {},
  journal = {{J}ournal of {G}eophysical {R}esearch. {S}olid {E}arth},
  volume = {120},
  numero = {9},
  pages = {6085--6101},
  ISSN = {2169-9313},
  year = {2015},
  DOI = {10.1002/2015jb011929},
  URL = {https://www.documentation.ird.fr/hor/{PAR}00013858},
}