中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Contribution of recycled oceanic crust to the extremely light molybdenum isotopic compositions of mid-ocean ridge basalts from the South China Sea

文献类型:期刊论文

作者Cai, Yu-Xin1,2,3; Huang, Xiao-Long2,3; Xu, Yi -Gang2,3; Yu, Yang2,3; Li, Jie2; Yang, Fan2,3; Ge, Zhen-Min
刊名CHEMICAL GEOLOGY
出版日期2024-02-20
卷号646页码:13
关键词Molybdenum isotopes Mid-ocean ridge basalts Recycled oceanic crust Mantle heterogeneity Plume-stagnant slab interaction South China Sea
ISSN号0009-2541
DOI10.1016/j.chemgeo.2023.121916
英文摘要The contribution of recycled oceanic crust to the mantle source of mid-ocean ridge basalts (MORBs) remains a subject of debate, as radiogenic isotopes alone yield ambiguous insights. Here, we present comprehensive data on whole-rock major element, trace element, and Mo-Nd-Hf isotopic compositions for MORB samples from International Ocean Discovery Program Expedition 349 sites U1431E and U1433B in the eastern (ESB) and southwestern (SWB) subbasins, respectively, of the South China Sea (SCS). The delta 98/95Mo values of the SCS MORBs exhibit a significant range (from -0.80%o to +0.05%o), in contrast to the restricted composition observed in MORBs (delta 98/95Mo = - 0.19%o +/- 0.01%o). The ESB MORBs display extremely light Mo isotopic compositions (delta 98/ 95Mo = - 0.80%o to - 0.24%o) with Nd-Hf isotopic compositions similar to those of Pacific MORB, whereas the SWB MORBs show higher delta 98/95Mo values (-0.44%o to +0.05%o) and depleted Nd-Hf isotopic compositions. The delta 98/95Mo values of the SCS MORBs are negatively correlated with Ce/Mo ratios and positively correlated with epsilon Hf values, suggesting the incorporation of dehydrated slab components into the source of the SCS MORBs. The subbasin-scale mantle heterogeneity in the SCS can be best explained by varying degrees of interaction between a mantle plume and stagnant slabs in the mantle transition zone, as suggested by mantle tomography. The rigid stagnant slab in the mantle transition zone beneath the SWB largely impeded the upwelling of the mantle plume, whereas the slab beneath the ESB was disrupted by the plume and subsequently transported into the upper mantle. This study, therefore, provides compelling evidence for the involvement of recycled oceanic slabs in generating MORB and the influence of an ascending mantle plume on seafloor spreading in a continental marginal sea. Mantle recycling processes in marginal sea basins exhibit distinct characteristics compared to those occurring in open oceans.
WOS研究方向Geochemistry & Geophysics
语种英语
WOS记录号WOS:001155829000001
源URL[http://ir.gig.ac.cn/handle/344008/76209]  
专题同位素地球化学国家重点实验室
通讯作者Huang, Xiao-Long
作者单位1.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
2.Chinese Acad Sci, Guangzhou Inst Geochem, CAS Ctr Excellence Deep Earth Sci, State Key Lab Isotope Geochem, Guangzhou 510640, Peoples R China
3.Southern Marine Sci & Engn Guangdong Lab, Guangzhou 511458, Peoples R China
推荐引用方式
GB/T 7714
Cai, Yu-Xin,Huang, Xiao-Long,Xu, Yi -Gang,et al. Contribution of recycled oceanic crust to the extremely light molybdenum isotopic compositions of mid-ocean ridge basalts from the South China Sea[J]. CHEMICAL GEOLOGY,2024,646:13.
APA Cai, Yu-Xin.,Huang, Xiao-Long.,Xu, Yi -Gang.,Yu, Yang.,Li, Jie.,...&Ge, Zhen-Min.(2024).Contribution of recycled oceanic crust to the extremely light molybdenum isotopic compositions of mid-ocean ridge basalts from the South China Sea.CHEMICAL GEOLOGY,646,13.
MLA Cai, Yu-Xin,et al."Contribution of recycled oceanic crust to the extremely light molybdenum isotopic compositions of mid-ocean ridge basalts from the South China Sea".CHEMICAL GEOLOGY 646(2024):13.

入库方式: OAI收割

来源:广州地球化学研究所

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