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DOI	10.1016/j.epsl.2020.116468
	Metal-silicate silicon isotopic fractionation and the composition of the bulk Earth
	Moynier F.; Deng Z.; Lanteri A.; Martins R.; Chaussidon M.; Savage P.; Siebert J.
发表日期	2020
ISSN	0012821X
卷号	549
英文摘要	The difference in the Si isotopic composition between the Earth and primitive meteorites had been used to constrain the amount of Si in the Earth's core. However, there is presently a debate on the magnitude of the isotopic fractionation between metal and silicates as function of temperature based on experimental data. Here, we use a natural sample, an enstatite meteorite, Itqyi, as a natural experiment to determine an independent Si isotopic fractionation factor between metal and silicate. We determined the temperature of equilibrium between metal and silicate as well as the Si isotopic composition between the phases. We find that the dependence of Si isotopes with temperature to be: [Formula presented] Using this dependence of the δ30Si with temperature we estimate the bulk Earth δ30Si as a function of Si content of the core for different plausible conditions. Even when using the most extreme parameters, we show that the bulk Earth must be isotopically heavier than any chondrites groups. We therefore confirm that core formation alone cannot account for the isotopic difference between the Earth and primitive meteorites. We show that there is no correlation between δ30Si and the Mg/Si ratio suggesting that forsterite fractionation in the solar nebula may have had only a limited effect, if any. Our new results therefore confirm that volatility should have had a fundamental effect in shaping terrestrial planets chemical composition. © 2020 Elsevier B.V.
关键词	accretion core formation geochemistry Itqyi meteorites planetary differentiation
英文关键词	Geochemistry; Isotopes; Metals; Meteorites; Silicates; Chemical compositions; Isotopic composition; Isotopic fractionation factors; Isotopic fractionations; Metal silicates; Natural experiment; Primitive meteorites; Terrestrial planets; Silicon; chemical composition; core (planetary); isotopic fractionation; meteorite; silicate; silicon; trace metal
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/202800
作者单位	Institut de Physique du Globe de Paris, Université de Paris, CNRS, 1 rue Jussieu, Paris, 75005, France; School of Earth and Environmental Sciences, University of St Andrews, Irvine Building, St Andrews, KY16 9AL, United Kingdom; Institut Universitaire de France, 103 boulevard Saint-Michel, Paris, 75005, France
推荐引用方式 GB/T 7714	Moynier F.,Deng Z.,Lanteri A.,et al. Metal-silicate silicon isotopic fractionation and the composition of the bulk Earth[J],2020,549.
APA	Moynier F..,Deng Z..,Lanteri A..,Martins R..,Chaussidon M..,...&Siebert J..(2020).Metal-silicate silicon isotopic fractionation and the composition of the bulk Earth.Earth and Planetary Science Letters,549.
MLA	Moynier F.,et al."Metal-silicate silicon isotopic fractionation and the composition of the bulk Earth".Earth and Planetary Science Letters 549(2020).