| DOI: | 10.1016/j.epsl.2020.116065
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| 论文题名: | Heterogeneous accretion of Earth inferred from Mo-Ru isotope systematics |
| 作者: | Hopp T.; Budde G.; Kleine T.
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| 刊名: | Earth and Planetary Science Letters
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| ISSN: | 0012821X
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| 出版年: | 2020
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| 卷: | 534 | | 语种: | 英语
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| 中文关键词: | heterogeneous accretion
; isotope dichotomy
; late stage accretion
; nucleosynthetic isotope anomalies
; origin of volatiles
; siderophile elements
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| 英文关键词: | Binary alloys
; Cosmology
; Isotopes
; Meteorites
; Molybdenum
; Silicates
; heterogeneous accretion
; Isotope anomalies
; Late stage
; origin of volatiles
; Siderophile elements
; Ruthenium
; accretion
; anomaly
; chondrite
; differentiation
; enstatite
; isotopic composition
; meteorite
; molybdenum
; ruthenium
; siderophile element
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| 英文摘要: | The Mo and Ru isotopic compositions of meteorites and the bulk silicate Earth (BSE) hold important clues about the provenance of Earth's building material. Prior studies have argued that non-carbonaceous (NC) and carbonaceous (CC) meteorite groups together define a Mo-Ru ‘cosmic’ correlation, and that the BSE plots on the extension of this correlation. These observations were taken as evidence that the final 10–15% of Earth's accreted material derived from a homogeneous inner disk reservoir with an enstatite chondrite-like isotopic composition. Here, using new Mo and Ru isotopic data for previously uninvestigated meteorite groups, we show that the Mo-Ru correlation only exists for NC meteorites, and that both the BSE and CC meteorites fall off this Mo-Ru correlation. These observations indicate that the final stages of Earth's accretion were heterogeneous and consisted of a mixture of NC and CC materials. The Mo-Ru isotope systematics are best accounted for by either an NC heritage of the late veneer combined with a CC heritage of the Moon-forming giant impactor, or by mixed NC-CC compositions for both components. The involvement of CC bodies in the late-stage accretionary assemblage of Earth is consistent with chemical models for core-mantle differentiation, which argue for the addition of more oxidized and volatile-rich material toward the end of Earth's formation. As such, this study resolves the inconsistencies between homogeneous accretion models based on prior interpretations of the Mo-Ru systematics of meteorites and the chemical evidence for heterogeneous accretion of Earth. © 2020 The Author(s) |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/165031
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| Appears in Collections: | 气候变化与战略
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作者单位: | Institut für Planetologie, University of Münster, Wilhelm-Klemm-Str. 10, Münster, 48149, Germany
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| Recommended Citation: | |
Hopp T.,Budde G.,Kleine T.. Heterogeneous accretion of Earth inferred from Mo-Ru isotope systematics[J]. Earth and Planetary Science Letters,2020-01-01,534
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