DOI: 10.1038/s41561-020-0617-y
论文题名: Heavy iron isotope composition of iron meteorites explained by core crystallization
作者: Ni P. ; Chabot N.L. ; Ryan C.J. ; Shahar A.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2020
卷: 13, 期: 9 起始页码: 611
结束页码: 615
语种: 英语
英文关键词: chemical composition
; experimental study
; gold
; high temperature
; iridium
; iron
; iron meteorite
; isotopic fractionation
; parent material
; sulfide
英文摘要: Similar to Earth, many large planetesimals in the Solar System experienced planetary-scale processes such as accretion, melting and differentiation. As their cores cooled and solidified, substantial chemical fractionation occurred due to solid metal–liquid metal fractionation. Iron meteorites—core remnants of these ancient planetesimals—record a history of this process. Recent iron isotope analyses of iron meteorites found their 57Fe/54Fe ratios to be heavier than chondritic by approximately 0.1 to 0.2 per mil for most meteorites, indicating that a common parent body process was responsible. However, the mechanism for this fractionation remains poorly understood. Here we experimentally show that the iron isotopic composition of iron meteorites can be explained solely by core crystallization. In our experiments of core crystallization at 1,300 °C, we find that solid metal becomes enriched in the heavier iron isotope by 0.13 per mil relative to liquid metal. Fractional crystallization modelling of the IIIAB iron meteorite parent body shows that observed iridium, gold and iron compositions can be simultaneously reproduced during core crystallization. The model implies the formation of complementary sulfur-rich components of the iron meteorite parental cores that remain unsampled by meteorite records and may be the missing reservoir of isotopically light iron. The lack of sulfide meteorites and previous trace element modelling predicting substantial unsampled volumes of iron meteorite parent cores support our findings. © 2020, The Author(s), under exclusive licence to Springer Nature Limited. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/169654
Appears in Collections: 气候变化与战略
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作者单位: Earth and Planets Laboratory, Carnegie Institution for Science, Washington, DC, United States; Johns Hopkins University Applied Physics Laboratory, Laurel, MD, United States
Recommended Citation:
Ni P.,Chabot N.L.,Ryan C.J.,et al. Heavy iron isotope composition of iron meteorites explained by core crystallization[J]. Nature Geoscience,2020-01-01,13(9)