气候变化领域集成服务门户(CCPortal): Convergent continental margin volcanic source for ash beds at the Permian-Triassic boundary; South China: Constraints from trace elements and Hf-isotopes

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DOI	10.1016/j.palaeo.2018.02.011
	Convergent continental margin volcanic source for ash beds at the Permian-Triassic boundary; South China: Constraints from trace elements and Hf-isotopes
	Wang X.; Cawood P.A.; Zhao L.; Chen Z.-Q.; Lyu Z.; Ma B.
发表日期	2019
ISSN	0031-0182
起始页码	154
结束页码	165
卷号	519
英文摘要	Volcanic activity around the time of the Permian-Triassic boundary (PTB) has been proposed as a trigger for the associated biocrisis. Multiple claystone beds are prominent near the PTB sections in South China. Twenty one PTB ash beds from three sections at Shangsi, Jianshi and Meishan in South China were sampled and analyzed. Volcanic ash geochemistry indicate dacite and rhyolite compositions. Zircons from the ash layers yield comparatively low Nb/Hf and high Th/Nb ratios, falling in the range of arc/orogenic-related settings. Zircon Hf-isotope compositions show that ε Hf (t) values vary from −11.7 to 1.8, indicating involvement of both juvenile and ancient crustal components. The ash beds (SS27a, JS129, JS130, JS133,MS25, MS26) near the biotic extinction horizon display a large variation in ε Hf (t) and relatively positive average values, indicating input of juvenile mantle or crust, and implying rapid transit through the older basement of the South China Craton. Spatial and temporal distribution of ash beds from thirty one PTB sections worldwide reveal that volcanic ash beds occur mainly in, or proximal to, the Tethys region and were sourced locally. Integration of Hf-isotope and trace-element compositions from magmatic zircons suggests that the PTB volcanism occurred along the convergent continent margin in, or near, southwestern South China as a result of the closure of the Paleo-Tethys Ocean. © 2018 Elsevier B.V.
语种	英语
scopus关键词	ash flow; continental margin; convergent margin; crustal structure; geochemistry; isotopic composition; magmatism; Permian-Triassic boundary; rhyolite; Tethys; trace element; volcanic ash; volcanism; zircon; China; Guangxi Zhuangzu; Hubei; Jianshi; Meishan; Shangsi; Zhejiang
来源期刊	Palaeogeography, Palaeoclimatology, Palaeoecology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/151049
作者单位	State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences (Wuhan), Wuhan, 430074, China; Department of Earth, Atmosphere and Environment, Monash UniversityVictoria 3800, Australia; Department of Earth Sciences, University of St AndrewsKY16 9AL, United Kingdom; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Wuhan), Wuhan, 430074, China
推荐引用方式 GB/T 7714	Wang X.,Cawood P.A.,Zhao L.,et al. Convergent continental margin volcanic source for ash beds at the Permian-Triassic boundary; South China: Constraints from trace elements and Hf-isotopes[J],2019,519.
APA	Wang X.,Cawood P.A.,Zhao L.,Chen Z.-Q.,Lyu Z.,&Ma B..(2019).Convergent continental margin volcanic source for ash beds at the Permian-Triassic boundary; South China: Constraints from trace elements and Hf-isotopes.Palaeogeography, Palaeoclimatology, Palaeoecology,519.
MLA	Wang X.,et al."Convergent continental margin volcanic source for ash beds at the Permian-Triassic boundary; South China: Constraints from trace elements and Hf-isotopes".Palaeogeography, Palaeoclimatology, Palaeoecology 519(2019).