DOI: 10.1038/ngeo2466
论文题名: Emergence of modern continental crust about 3 billion years ago
作者: Dhuime B. ; Wuestefeld A. ; Hawkesworth C.J.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2015
卷: 8, 期: 7 起始页码: 552
结束页码: 555
语种: 英语
英文摘要: The continental crust is the principal record of conditions on the Earth during the past 4.4 billion years. However, how the continental crust formed and evolved through time remains highly controversial. In particular, the composition and thickness of juvenile continental crust are unknown. Here we show that Rb/Sr ratios can be used as a proxy for both the silica content and the thickness of the continental crust. We calculate Rb/Sr ratios of the juvenile crust for over 13,000 samples, with Nd model ages ranging from the Hadean to Phanerozoic. The ratios were calculated based on the evolution of Sr isotopes in the period between the T DM Nd model age and the crystallization of the samples analysed. We find that the juvenile crust had a low silica content and was largely mafic in composition during the first 1.5 billion years of Earthâ €™ s evolution, consistent with magmatism on a pre-plate tectonics planet. About 3 billion years ago, the Rb/Sr ratios of the juvenile continental crust increased, indicating that the newly formed crust became more silica-rich and probably thicker. This transition is in turn linked to the onset of plate tectonics and an increase of continental detritus into the oceans. © 2015 Macmillan Publishers Limited. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/106280
Appears in Collections: 气候减缓与适应 科学计划与规划
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作者单位: Bristol Isotope Group, School of Earth Sciences, University of Bristol, Queens Road, Bristol, United Kingdom; NORSAR, Gunnar Randers vei 15, Kjeller, Norway; Department of Earth and Environmental Sciences, University of St Andrews, North Street, St Andrews, United Kingdom
Recommended Citation:
Dhuime B.,Wuestefeld A.,Hawkesworth C.J.. Emergence of modern continental crust about 3 billion years ago[J]. Nature Geoscience,2015-01-01,8(7)