DOI: 10.1016/j.epsl.2017.11.034
Scopus记录号: 2-s2.0-85035119007
论文题名: Late metal–silicate separation on the IAB parent asteroid: Constraints from combined W and Pt isotopes and thermal modelling
作者: Hunt A.C. ; Cook D.L. ; Lichtenberg T. ; Reger P.M. ; Ek M. ; Golabek G.J. ; Schönbächler M.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 482 起始页码: 490
结束页码: 500
语种: 英语
英文关键词: Hf–W chronometry
; IAB iron meteorites
; multi-collector ICP-MS
; Planetesimals
; Pt isotopes
; thermal histories
Scopus关键词: Iron
; Isotopes
; Metals
; Meteorites
; Neutrons
; Platinum
; Separation
; Silicates
; Internal heating
; Iron meteorites
; Multi-collector
; Neutron capture
; Planetesimals
; Short-lived radionuclides
; Thermal history
; Thermal modelling
; Tungsten
; asteroid
; inductively coupled plasma method
; iron meteorite
; isotopic composition
; mass spectrometry
; modeling
; parent body
; planetesimal
; platinum
; separation
; silicate
; tungsten
英文摘要: The short-lived 182Hf–182W decay system is a powerful chronometer for constraining the timing of metal–silicate separation and core formation in planetesimals and planets. Neutron capture effects on W isotopes, however, significantly hamper the application of this tool. In order to correct for neutron capture effects, Pt isotopes have emerged as a reliable in-situ neutron dosimeter. This study applies this method to IAB iron meteorites, in order to constrain the timing of metal segregation on the IAB parent body. The ε182W values obtained for the IAB iron meteorites range from −3.61 ± 0.10 to −2.73 ± 0.09. Correlating εiPt with ε182W data yields a pre-neutron capture ε182W of −2.90 ± 0.06. This corresponds to a metal–silicate separation age of 6.0 ± 0.8 Ma after CAI for the IAB parent body, and is interpreted to represent a body-wide melting event. Later, between 10 and 14 Ma after CAI, an impact led to a catastrophic break-up and subsequent reassembly of the parent body. Thermal models of the interior evolution that are consistent with these estimates suggest that the IAB parent body underwent metal–silicate separation as a result of internal heating by short-lived radionuclides and accreted at around 1.4±0.1 Ma after CAIs with a radius of greater than 60 km. © 2017 The Authors Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/110128
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Institute of Geochemistry and Petrology, ETH Zürich, Clausiusstrasse 25, Zürich, 8092, Switzerland; Institute of Geophysics, ETH Zürich, Sonneggstrasse 5, Zürich, 8092, Switzerland; Institute for Astronomy, ETH Zürich, Wolfgang-Pauli-Strasse 27, Zürich, 8093, Switzerland; Bayerisches Geoinstitut, University of Bayreuth, Universitätsstrasse 30, Bayreuth, 95440, Germany
Recommended Citation:
Hunt A.C.,Cook D.L.,Lichtenberg T.,et al. Late metal–silicate separation on the IAB parent asteroid: Constraints from combined W and Pt isotopes and thermal modelling[J]. Earth and Planetary Science Letters,2018-01-01,482