The Milton pallasite and South Byron Trio irons: Evidence for oxidation and core crystallization

doi:10.1016/j.gca.2019.06.005

CORC > 地质与地球物理研究所 > 中国科学院地质与地球物理研究所 > 中国科学院页岩气与地质工程重点实验室

	The Milton pallasite and South Byron Trio irons: Evidence for oxidation and core crystallization
	McCoy, T. J.1; Corrigan, C. M.1; Nagashima, K.2; Reynolds, V. S.1,3; Ash, R. D.4; McDonough, W. F.4; Yang, J.5,6,7; Goldstein, J., I 5; Hilton, C. D.4
刊名	GEOCHIMICA ET COSMOCHIMICA ACTA
	2019-08-15
卷号	259 页码:358-370
关键词	Meteorites Iron meteorites Pallasites Cooling rates Oxygen isotopes Siderophile elements Oxidation Crystallization
ISSN号	0016-7037
DOI	10.1016/j.gca.2019.06.005
英文摘要	The link between the Milton pallasite and the South Byron Trio irons is examined through metallography and metallogaphic cooling rates; major, minor, and trace element compositions of metal; inclusion mineralogy and mineral compositions; and oxygen isotopic compositions. The metallic hosts of these Ni-rich meteorites (18.2-20.3 wt% Ni) are dominated by plessite with spindles of kamacite and schreibersite. The presence of similar to 50 nm wide tetrataenite and absence of high-Ni particles in the cloudy zone in Milton suggest cooling of similar to 2000 K/Myr or >10,000 K/Myr. Compositionally, the metallic host in all four meteorites exhibits modest (1-2 orders of magnitude compared to CI chondrites) depletions of volatile elements relative to refractory elements, and marked depletions in the redox sensitive elements W, Mo, Fe, and P. Oxygen isotopic compositions (Delta O-17) are, within uncertainty, the same for the Milton and the South Byron Trio and for IVB irons. Similarities in metallography, metal composition, inclusion mineralogy, and oxygen (Delta O-17), molybdenum and ruthenium isotopic composition suggest that the Milton pallasite and South Byron Trio irons could have originated on a common parent body as chemically distinct melt, or on separate parent bodies that experience similar cosmochemical and geochemical processes. The Milton pallasite and South Byron Trio irons share a number of properties with IVB irons, including metallography, enrichment in highly siderophile elements and nickel, inclusion mineralogy and oxygen isotopic composition, suggesting they formed in a similar nebular region through common processes, although Milton and the South Byron Trio did not experience the dramatic volatile loss of the IVB irons. Depletions in W, Mo, Fe, and P relative to elements of similar volatility likely result from oxidation, either in the nebula prior to accretion or on the parent body during melting. Oxidation of similar to 73 wt% Fe is indicated, with a correspondingly FeO-rich mantle and smaller core. If Milton and the South Byron Trio sample a common core, Milton formed near the surface of the core after stripping of the silicate shell and may have experienced rapid solidification and contamination by an impactor. The molten core, from which the South Byron Trio irons crystallized, solidified from the outside in. (C) 2019 Elsevier Ltd. All rights reserved.
资助项目	NASA ; National Science Foundation ; Smithsonian Institution ; NASA's Cosmochemistry and Emerging Worlds programs
WOS关键词	MAIN-GROUP PALLASITES ; CHEMICAL CLASSIFICATION ; GE CONCENTRATIONS ; OXYGEN-ISOTOPE ; COOLING RATES ; GROUP IVA ; METEORITES ; HISTORIES ; ORIGIN ; AGE
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	PERGAMON-ELSEVIER SCIENCE LTD
WOS记录号	WOS:000474198900021
资助机构	NASA ; NASA ; National Science Foundation ; National Science Foundation ; Smithsonian Institution ; Smithsonian Institution ; NASA's Cosmochemistry and Emerging Worlds programs ; NASA's Cosmochemistry and Emerging Worlds programs ; NASA ; NASA ; National Science Foundation ; National Science Foundation ; Smithsonian Institution ; Smithsonian Institution ; NASA's Cosmochemistry and Emerging Worlds programs ; NASA's Cosmochemistry and Emerging Worlds programs ; NASA ; NASA ; National Science Foundation ; National Science Foundation ; Smithsonian Institution ; Smithsonian Institution ; NASA's Cosmochemistry and Emerging Worlds programs ; NASA's Cosmochemistry and Emerging Worlds programs ; NASA ; NASA ; National Science Foundation ; National Science Foundation ; Smithsonian Institution ; Smithsonian Institution ; NASA's Cosmochemistry and Emerging Worlds programs ; NASA's Cosmochemistry and Emerging Worlds programs
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/92679]
专题	地质与地球物理研究所_中国科学院页岩气与地质工程重点实验室
通讯作者	McCoy, T. J.
作者单位	1.Smithsonian Inst, Dept Mineral Sci, Washington, DC 20560 USA 2.Univ Hawaii Manoa, Hawaii Inst Geophys & Planetol, Honolulu, HI 96822 USA 3.UNC Charlotte, Dept Geog & Earth Sci, Charlotte, NC 28223 USA 4.Univ Maryland, Dept Geol, College Pk, MD 20742 USA 5.Univ Massachusetts, Dept Mech & Ind Engn, Amherst, MA 01003 USA 6.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Shale Gas & Geoengn, Beijing 100029, Peoples R China 7.Univ Chinese Acad Sci, Inst Earth Sci, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	McCoy, T. J.,Corrigan, C. M.,Nagashima, K.,et al. The Milton pallasite and South Byron Trio irons: Evidence for oxidation and core crystallization[J]. GEOCHIMICA ET COSMOCHIMICA ACTA,2019,259:358-370.
APA	McCoy, T. J..,Corrigan, C. M..,Nagashima, K..,Reynolds, V. S..,Ash, R. D..,...&Hilton, C. D..(2019).The Milton pallasite and South Byron Trio irons: Evidence for oxidation and core crystallization.GEOCHIMICA ET COSMOCHIMICA ACTA,259,358-370.
MLA	McCoy, T. J.,et al."The Milton pallasite and South Byron Trio irons: Evidence for oxidation and core crystallization".GEOCHIMICA ET COSMOCHIMICA ACTA 259(2019):358-370.