DOI: 10.1016/j.epsl.2020.116585
论文题名: Early evolution of the solar accretion disk inferred from Cr-Ti-O isotopes in individual chondrules
作者: Schneider J.M. ; Burkhardt C. ; Marrocchi Y. ; Brennecka G.A. ; Kleine T.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 551 语种: 英语
中文关键词: chondrules
; isotopic anomalies
; meteorite dichotomy
; nebular mixing
英文关键词: Dust
; Isotopes
; Meteorites
; Mixing
; Titanium compounds
; Accretion disks
; Carbonaceous chondrites
; Isotope anomalies
; Isotopic composition
; Isotopic variations
; Local heterogeneity
; Mixing process
; Transport process
; Chromium compounds
; accretion
; chondrule
; chromium
; evolution
; isotopic analysis
; meteorite
; oxygen isotope
; titanium
英文摘要: Isotopic anomalies in chondrules hold important clues about the dynamics of mixing and transport processes in the solar accretion disk. The meaning of these anomalies is debated and they have been interpreted to indicate either disk-wide transport of chondrules or local heterogeneities of chondrule precursors. However, all previous studies relied on isotopic data for a single element (either Cr, Ti, or O), which does not allow distinguishing between source and precursor signatures as the cause of the chondrules' isotope anomalies. To overcome this problem, we obtained the first combined O, Ti, and Cr isotope data for individual chondrules from enstatite, ordinary, and carbonaceous chondrites. We find that chondrules from non-carbonaceous (NC) chondrites have relatively homogeneous Δ17O, ε50Ti, and ε54Cr, which are similar to the compositions of their host chondrites. By contrast, chondrules from carbonaceous chondrites (CC) have more variable compositions, some of which differ from the host chondrite compositions. Although the compositions of the analyzed CC and NC chondrules may overlap for either ε50Ti, ε54Cr, or Δ17O, in multi-isotope space, none of the CC chondrules plot in the compositional field of NC chondrites, and no NC chondrule plots within the field of CC chondrites. As such, our data reveal a fundamental isotopic difference between NC and CC chondrules, which is inconsistent with a disk-wide transport of chondrules across and between the NC and CC reservoirs. Instead, the isotopic variations among CC chondrules reflect local precursor heterogeneities, which most likely result from mixing between NC-like dust and a chemically diverse dust component that was isotopically similar to CAIs and AOAs. The same mixing processes, but on a larger, disk-wide scale, were likely responsible for establishing the distinct isotopic compositions of the NC and CC reservoirs, which represent in inner and outer disk, respectively. © 2020 The Author(s) Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165258
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-Straße 1048149, Germany; CRPG, CNRS, Université de Lorraine, UMR 7358, Vandoeuvre-lès-Nancy, 54501, France; Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, United States
Recommended Citation:
Schneider J.M.,Burkhardt C.,Marrocchi Y.,et al. Early evolution of the solar accretion disk inferred from Cr-Ti-O isotopes in individual chondrules[J]. Earth and Planetary Science Letters,2020-01-01,551