start-ver=1.4
cd-journal=joma
no-vol=11
cd-vols=
no-issue=1
article-no=
start-page=4387
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2020
dt-pub=20200128
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=Formation of bridgmanite-enriched layer at the top lower-mantle during magma ocean solidification
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=Thermochemical heterogeneities detected today in the Earth's mantle could arise from ongoing partial melting in different mantle regions. A major open question, however, is the level of chemical stratification inherited from an early magma-ocean (MO) solidification. Here we show that the MO crystallized homogeneously in the deep mantle, but with chemical fractionation at depths around 1000 km and in the upper mantle. Our arguments are based on accurate measurements of the viscosity of melts with forsterite, enstatite and diopside compositions up to similar to 30 GPa and more than 3000 K at synchrotron X-ray facilities. Fractional solidification would induce the formation of a bridgmanite-enriched layer at similar to 1000 km depth. This layer may have resisted to mantle mixing by convection and cause the reported viscosity peak and anomalous dynamic impedance. On the other hand, fractional solidification in the upper mantle would have favored the formation of the first crust.
en-copyright=
kn-copyright=

en-aut-name=XieLongjian
en-aut-sei=Xie
en-aut-mei=Longjian
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=1
ORCID=

en-aut-name=YonedaAkira
en-aut-sei=Yoneda
en-aut-mei=Akira
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=2
ORCID=

en-aut-name=YamazakiDaisuke
en-aut-sei=Yamazaki
en-aut-mei=Daisuke
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=3
ORCID=

en-aut-name=ManthilakeGeeth
en-aut-sei=Manthilake
en-aut-mei=Geeth
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=4
ORCID=

en-aut-name=HigoYuji
en-aut-sei=Higo
en-aut-mei=Yuji
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=5
ORCID=

en-aut-name=TangeYoshinori
en-aut-sei=Tange
en-aut-mei=Yoshinori
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=6
ORCID=

en-aut-name=GuignotNicolas
en-aut-sei=Guignot
en-aut-mei=Nicolas
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=7
ORCID=

en-aut-name=KingAndrew
en-aut-sei=King
en-aut-mei=Andrew
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=8
ORCID=

en-aut-name=ScheelMario
en-aut-sei=Scheel
en-aut-mei=Mario
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=9
ORCID=

en-aut-name=AndraultDenis
en-aut-sei=Andrault
en-aut-mei=Denis
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=10
ORCID=

affil-num=1
en-affil=Institute for Planetary Materials, Okayama University
kn-affil=

affil-num=2
en-affil=Institute for Planetary Materials, Okayama University
kn-affil=

affil-num=3
en-affil=Institute for Planetary Materials, Okayama University
kn-affil=

affil-num=4
en-affil=Laboratoire Magmas et Volcans, Université Clermont Auvergne, CNRS, IRD, OPGC
kn-affil=

affil-num=5
en-affil=Japan Synchrotron Radiation Research Institute
kn-affil=

affil-num=6
en-affil=Japan Synchrotron Radiation Research Institute
kn-affil=

affil-num=7
en-affil=Synchrotron SOLEIL
kn-affil=

affil-num=8
en-affil=Synchrotron SOLEIL
kn-affil=

affil-num=9
en-affil=Synchrotron SOLEIL
kn-affil=

affil-num=10
en-affil=Laboratoire Magmas et Volcans, Université Clermont Auvergne, CNRS, IRD, OPGC
kn-affil=
END