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DOI	10.1130/B35464.1
	Geochemical, biostratigraphic, and high-resolution geochronological constraints on the waning stage of Emeishan Large Igneous Province
	Zhong Y.; Mundil R.; Chen J.; Yuan D.; Denyszyn S.W.; Jost A.B.; Payne J.L.; He B.; Shen S.; Xu Y.
发表日期	2020
ISSN	167606
起始页码	1969
结束页码	1986
卷号	132 期号:2021-09-10
英文摘要	The initiation and peak magmatic periods of the Emeishan Large Igneous Province (LIP) are well constrained by both biostratigraphic and radioisotopic dating methods; however, the age of cessation of volcanism is poorly constrained and continues to be debated. Marine carbonates interbedded with volcanic ashes across the Guadalupian-Lopingian boundary (GLB) are widespread in south China, and these ashes provide an opportunity to study its timing, origin, and potential relationship with the Emeishan LIP. Here we present biostratigraphic constraints, mineralogical and geochemical characteristics, and high-resolution geochronology of ash layers from the Maoershan and Chaotian sections. Stratigraphic correlation, especially conodont biostratigraphy, confines these ashes to the early Wuchiapingian. Those altered ashes are geochemically akin to alkali tonsteins from the coal seams of the lower Xuanwei/Lungtan Formation in southwest China. The ashes postdating the GLB yield a coherent cluster of zircon U-Pb ages with weighted mean 206Pb/238U ages of 258.82 ± 0.61 Ma to 257.39 ± 0.68 Ma, in agreement with the ages of intrusive rocks (259.6 ± 0.5 Ma to 257.6 ± 0.5 Ma) in the central Emeishan LIP. Moreover, the εHf(t) values of zircons from the ashes vary from +2.5 to +10.6, a range consistent with that of the Emeishan LIP. The results collectively suggest that the early Wuchiapingian volcanic ashes are a product of extrusive alkaline magmatism and most likely mark the waning stage of the Emeishan volcanism, which may have continued until ca. 257.4 Ma in the early Wuchiapingian. © 2019 Geological Society of America.
语种	英语
来源期刊	Bulletin of the Geological Society of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/184740
作者单位	State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Science, Guangzhou, 510640, China; Berkeley Geochronology Center, Berkeley, CA 94709, United States; State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, 39 East Beijing Road, Nanjing, 210008, China; School of Earth Science, University of Western Australia, Perth, WA 6009, Australia; Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Department of Geological Sciences, Stanford University, Stanford, CA 94305, United States; School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, China
推荐引用方式 GB/T 7714	Zhong Y.,Mundil R.,Chen J.,et al. Geochemical, biostratigraphic, and high-resolution geochronological constraints on the waning stage of Emeishan Large Igneous Province[J],2020,132(2021-09-10).
APA	Zhong Y..,Mundil R..,Chen J..,Yuan D..,Denyszyn S.W..,...&Xu Y..(2020).Geochemical, biostratigraphic, and high-resolution geochronological constraints on the waning stage of Emeishan Large Igneous Province.Bulletin of the Geological Society of America,132(2021-09-10).
MLA	Zhong Y.,et al."Geochemical, biostratigraphic, and high-resolution geochronological constraints on the waning stage of Emeishan Large Igneous Province".Bulletin of the Geological Society of America 132.2021-09-10(2020).