气候变化领域集成服务门户(CCPortal): Halogen (F, Cl) Concentrations and Sr-Nd-Pb-B Isotopes of the Basaltic Andesites From the Southern Okinawa Trough: Implications for the Recycling of Subducted Serpentinites

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DOI	10.1029/2021JB021709
	Halogen (F, Cl) Concentrations and Sr-Nd-Pb-B Isotopes of the Basaltic Andesites From the Southern Okinawa Trough: Implications for the Recycling of Subducted Serpentinites
	Zhang Y.; Gaetani G.; Zeng Z.; Monteleone B.; Yin X.; Wang X.; Chen S.
发表日期	2021
ISSN	21699313
卷号	126 期号:3
英文摘要	Serpentinites are increasingly recognized as playing an important role in the global geochemical cycle. However, discriminating the contributions of serpentinites to arc magmas from those of other subduction components is challenging. The Okinawa Trough is a back-arc basin developed behind the Ryukyu subduction zone, where magmas are extensively affected by sediment subduction. In this study, we reported the F-Cl concentrations and Sr-Nd-Pb-B isotopes of basaltic andesites from the Yaeyama Graben, Yonaguni Graben, and Irabu Knoll in the southern Okinawa Trough. The Irabu Knoll lavas show the most enrichment of fluid-mobile elements and F ± Cl, and have the heaviest B isotopes (δ11B: +6.6 ± 1.5‰). They also have decoupled Sr-Nd isotopes: higher 87Sr/86Sr (∼0.7049) but have no obvious decrease of 143Nd/144Nd (∼0.5128). Results from slab dehydration modeling and mixing calculations suggest that the heavy δ11B in the Irabu Knoll lavas is not consistent with fluids derived from altered oceanic crust (AOC), sediments, or wedge serpentinites (formed in the mantle wedge), but rather from slab serpentinites (formed within the subducting plate); sediments control the subduction input of Nd, whereas the decoupled Sr-Nd isotopes are most likely due to the excess radiogenic Sr carried by AOC fluids. Our results imply that recycling of serpentinite fluids and AOC fluids are usually coupled in subduction zones, as the arc lavas influenced by subducted serpentinite generally show Sr-Nd isotopes decoupling. The large variation of Sr-Nd-B isotopes observed in a relatively localized area is consistent with a focused migration through the mantle wedge of components from multiple sources. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	AOC; boron isotope; geochemical cycling; serpentinite; Sr-Nd isotope decoupling; subduction zone
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187314
作者单位	Key Laboratory of Marine Geology and Environment, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China; Laboratory for Marine Mineral Resources, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, China; Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, United States; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China; University of Chinese Academy of Sciences, Beijing, China
推荐引用方式 GB/T 7714	Zhang Y.,Gaetani G.,Zeng Z.,et al. Halogen (F, Cl) Concentrations and Sr-Nd-Pb-B Isotopes of the Basaltic Andesites From the Southern Okinawa Trough: Implications for the Recycling of Subducted Serpentinites[J],2021,126(3).
APA	Zhang Y..,Gaetani G..,Zeng Z..,Monteleone B..,Yin X..,...&Chen S..(2021).Halogen (F, Cl) Concentrations and Sr-Nd-Pb-B Isotopes of the Basaltic Andesites From the Southern Okinawa Trough: Implications for the Recycling of Subducted Serpentinites.Journal of Geophysical Research: Solid Earth,126(3).
MLA	Zhang Y.,et al."Halogen (F, Cl) Concentrations and Sr-Nd-Pb-B Isotopes of the Basaltic Andesites From the Southern Okinawa Trough: Implications for the Recycling of Subducted Serpentinites".Journal of Geophysical Research: Solid Earth 126.3(2021).