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DOI	10.1016/j.epsl.2020.116419
	Two-stage formation of pallasites and the evolution of their parent bodies revealed by deformation experiments
	Walte N.P.; Solferino G.F.D.; Golabek G.J.; Silva Souza D.; Bouvier A.
发表日期	2020
ISSN	0012821X
卷号	546
英文摘要	Pallasites, stony-iron meteorites predominantly composed of olivine crystals and Fe-Ni metal, are samples of the interior of early solar system bodies and can thus provide valuable insights into the formation of terrestrial planets. However, pallasite origin is controversial, either sampling the core-mantle boundary or the shallower mantle of planetesimals that suffered an impact. We present high strain-rate deformation experiments with the model system olivine + FeS melt ± gold melt to investigate pallasite formation and the evolution of their parent bodies and compare the resulting microstructures to two samples of Seymchan pallasite. Our experiments reproduced the major textural features of pallasites including the different olivine shapes, olivine aggregates, and the distribution of the metal and sulfide phases. These results indicate that pallasites preserve evidence for a two-stage formation process including inefficient core-mantle differentiation and an impact causing disruption, metal melt injection, and fast cooling within months to years. Olivine aggregates, important constituents of angular pallasites, are reinterpreted as samples of a partially differentiated mantle containing primordial metallic melt not stemming from the impactor. The long-term retention of more than 10 vol% of metal melt in a silicate mantle sampled by olivine aggregates indicates high effective percolation thresholds and inefficient metal-silicate differentiation in planetesimals not experiencing a magma ocean stage. © 2020 Elsevier B.V.
关键词	core-mantle differentiation deformation experiments early solar system microstructure pallasite texture
英文关键词	Aggregates; Binary alloys; Deformation; Iodine compounds; Iron compounds; Metal melting; Metals; Nitrogen compounds; Olivine; Phosphorus compounds; Silicates; Solvents; Strain rate; Uranium compounds; Core-mantle boundary; Early solar systems; High strain rate deformation; Long-term retention; Metal-silicate differentiation; Percolation thresholds; Stage formations; Terrestrial planets; Sulfur compounds; core-mantle boundary; deformation; iron meteorite; microstructure; olivine; pallasite; parent body; planetesimal; silicate melt; stony meteorite; strain rate
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/202954
作者单位	Heinz Meier-Leibnitz Centre for Neutron Science (MLZ), Technical University Munich, Garching, 85748, Germany; Department of Earth Sciences, Royal Holloway University of London, Egham, TW20 0EX, United Kingdom; Bayerisches Geoinstitut (BGI), University of Bayreuth, Bayreuth, 95447, Germany
推荐引用方式 GB/T 7714	Walte N.P.,Solferino G.F.D.,Golabek G.J.,et al. Two-stage formation of pallasites and the evolution of their parent bodies revealed by deformation experiments[J],2020,546.
APA	Walte N.P.,Solferino G.F.D.,Golabek G.J.,Silva Souza D.,&Bouvier A..(2020).Two-stage formation of pallasites and the evolution of their parent bodies revealed by deformation experiments.Earth and Planetary Science Letters,546.
MLA	Walte N.P.,et al."Two-stage formation of pallasites and the evolution of their parent bodies revealed by deformation experiments".Earth and Planetary Science Letters 546(2020).