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DOI	10.1016/j.epsl.2020.116644
	Determination of the refractory enrichment factor of the bulk silicate Earth from metal-silicate experiments on rare Earth elements
	Faure P.; Boyet M.; Bouhifd M.A.; Manthilake G.; Hammouda T.; Devidal J.-L.
发表日期	2021
ISSN	0012821X
卷号	554
英文摘要	This study investigates the partitioning of rare earth elements (REE) from La to Gd between molten metal and silicate to evaluate potential fractionation occurring during core-mantle differentiation. We report molten metal-silicate liquid partition coefficients from 24 multi-anvil experiments, extending the range of pressure, previously ranging from 1 to 8 GPa, up to 14 GPa. Experiments were performed at temperatures of between 2300 and 2560 K, and for oxygen fugacities ranging from the IW (Iron-Wüstite buffer) to IW–4. Metal-silicate partition coefficients for the studied REE vary with the oxygen fugacity and S concentration in the metallic phase of the system. These elements were all lithophile during the Earth's accretion. By compiling all existing data on molten metal-silicate liquid partitioning, REE partitioning between the mantle and core during the Earth's accretion can be determined for a wide range of P, T and fo2 conditions representing the early evolution of planetary bodies from planetesimals to planets. REE concentrations of the bulk silicate Earth (BSE) are calculated from accretion scenarios using varying proportions and compositions of chondritic building blocks. The models selected are those that reproduce the Earth's nucleosynthetic isotope signature and the Ni/Co, Th/U and Nb/Ta ratios of the BSE. The BSE refractory element enrichment factor determined from REE data is equal to 2.88 (relative to CI chondrites). This calculation takes into account the depletion in volatile elements in the Earth compared to chondrites. This new estimate is in good agreement with previous determinations based on analysis of the upper mantle rocks, which supports the idea of a chemically homogeneous mantle. We also confirm that the formation of the core, with or without segregation of a sulfide phase, does not fractionate Sm/Nd and cannot be responsible for the 142Nd excess measured in modern terrestrial samples relative to chondrites. © 2020 Elsevier B.V.
关键词	core formation Earth mantle Earth's accretion metal–silicate partitioning rare Earth elements refractory lithophile elements
英文关键词	Liquid metals; Meteorites; Oxygen; Planets; Rare earth elements; Rare earths; Refractory materials; Silicates; Structural geology; Sulfur compounds; Building blockes; Bulk silicate earth; Earth's accretion; Enrichment factors; Isotope signatures; Partition coefficient; Refractory elements; Volatile elements; Refractory metals; accretion; core (planetary); enrichment; experiment; fractionation; mantle; partitioning; rare earth element; refraction; silicate mineral; Chondrites
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203085
作者单位	Laboratoire Magmas et Volcans, Université Clermont Auvergne, CNRS UMR 6524, OPGC-IRD, Clermont-Ferrand, F-63000, France
推荐引用方式 GB/T 7714	Faure P.,Boyet M.,Bouhifd M.A.,et al. Determination of the refractory enrichment factor of the bulk silicate Earth from metal-silicate experiments on rare Earth elements[J],2021,554.
APA	Faure P.,Boyet M.,Bouhifd M.A.,Manthilake G.,Hammouda T.,&Devidal J.-L..(2021).Determination of the refractory enrichment factor of the bulk silicate Earth from metal-silicate experiments on rare Earth elements.Earth and Planetary Science Letters,554.
MLA	Faure P.,et al."Determination of the refractory enrichment factor of the bulk silicate Earth from metal-silicate experiments on rare Earth elements".Earth and Planetary Science Letters 554(2021).