DOI: 10.1002/2014GL060757
论文题名: Dating terrestrial impact structures: U-Pb depth profiles and (U-Th)/He ages of zircon
作者: Wielicki M.M. ; Harrison T.M. ; Stockli D.
刊名: Geophysical Research Letters
ISSN: 0094-10621
EISSN: 1944-10352
出版年: 2014
卷: 41, 期: 12 起始页码: 4168
结束页码: 4175
语种: 英语
Scopus关键词: Impact structures
; breccia
; helium
; radiocarbon dating
; uranium-lead dating
; zircon
英文摘要: We investigate the presence of epitaxial overgrowth rims and "reset" zircon, complete loss of radiogenic lead (Pb∗), from terrestrial impactites to constrain the occurrence of such phenomenon in impact environments and their possible use in dating impact events. We also explore (U-Th)/He dating of zircon to evaluate this geochronometer in accurately identifying impact ages, particularly when no dateable melt sheet exists. Our results show that (U-Th)/He ages of zircon from the brecciated, and presumably shocked target, can accurately date an impact event and provides another tool to determine impact ages when no melt sheet exists, an alternative to problematic interpretations of commonly used apparent 40Ar/39Ar plateau ages. No evidence of epitaxial overgrowth rims and/or reset zircon was observed, suggesting that zircons within shocked impactites have remarkably slow Pb diffusion and possibly explaining the relatively few reset grains reported in terrestrial impactites. © 2014. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84902910339&doi=10.1002%2f2014GL060757&partnerID=40&md5=32205c8f6c1b4a83a130b6c773bb33c6
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/7885
Appears in Collections: 气候减缓与适应
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作者单位: Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, CA, United States
Recommended Citation:
Wielicki M.M.,Harrison T.M.,Stockli D.. Dating terrestrial impact structures: U-Pb depth profiles and (U-Th)/He ages of zircon[J]. Geophysical Research Letters,2014-01-01,41(12).