DOI: 10.1016/j.epsl.2018.09.021
Scopus记录号: 2-s2.0-85054037343
论文题名: Excess 180W in IIAB iron meteorites: Identification of cosmogenic, radiogenic, and nucleosynthetic components
作者: Cook D.L. ; Smith T. ; Leya I. ; Hilton C.D. ; Walker R.J. ; Schönbächler M.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 503 起始页码: 29
结束页码: 36
语种: 英语
英文关键词: 184Os–180W systematics
; galactic cosmic rays
; iron meteorites
; nucleosynthesis
; tungsten isotopes
Scopus关键词: Cosmology
; Iron
; Isotopes
; Meteorites
; Nucleosynthesis
; Trace elements
; Decay constants
; Early solar systems
; Galactic cosmic rays
; Iron meteorites
; Potential decay
; Process Variability
; Spallation reactions
; Trace element concentrations
; Cosmic rays
英文摘要: The origin of 180W excesses in iron meteorites has been a recently debated topic. Here, a suite of IIAB iron meteorites was studied in order to accurately determine the contribution from galactic cosmic rays (GCR) and from potential decay of 184Os to measured excesses in the minor isotope 180W. In addition to W isotopes, trace element concentrations (Re, Os, Ir, Pt, W) were determined on the same samples, as well as their cosmic ray exposure ages, using 36Cl–36Ar systematics. These data were used in combination with an improved model of GCR effects on W isotopes to correct effects resulting from neutron capture and spallation reactions. After these corrections, the residual 180W excesses correlate with Os/W ratios and indicate a clear contribution from 184Os decay. A newly derived decay constant is equivalent to a half-life for 184Os of (3.38 ± 2.13) × 1013 a. Furthermore, when the data are plotted on an Os–W isochron diagram, the intercept (ε180Wi = 0.63 ± 0.35) reveals that the IIAB parent body was characterized by a small initial nucleosynthetic excess in 180W upon which radiogenic and GCR effects were superimposed. This is the first cogent evidence for p-process variability in W isotopes in early Solar System material. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109628
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: Institut für Geochemie und Petrologie, ETH Zürich, Clausiusstrasse 25, Zürich, 8092, Switzerland; Space Research and Planetology, University of Bern, Sidlerstrasse 5, Bern, 3012, Switzerland; Department of Geology, University of Maryland, 8000 Regents Dr., College Park, MD 20742, United States
Recommended Citation:
Cook D.L.,Smith T.,Leya I.,et al. Excess 180W in IIAB iron meteorites: Identification of cosmogenic, radiogenic, and nucleosynthetic components[J]. Earth and Planetary Science Letters,2018-01-01,503