DOI: 10.1016/j.epsl.2020.116644
论文题名: Determination of the refractory enrichment factor of the bulk silicate Earth from metal-silicate experiments on rare Earth elements
作者: Faure P. ; Boyet M. ; Bouhifd M.A. ; Manthilake G. ; Hammouda T. ; Devidal J.-L.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2021
卷: 554 语种: 英语
中文关键词: 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
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. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165463
Appears in Collections: 气候变化与战略
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作者单位: Laboratoire Magmas et Volcans, Université Clermont Auvergne, CNRS UMR 6524, OPGC-IRD, Clermont-Ferrand, F-63000, France
Recommended Citation:
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]. Earth and Planetary Science Letters,2021-01-01,554