Geochemical data compilation of Cenozoic basalts recovered from the South China Sea tectonic domain shows westward weakening of the influence of a focal zone‐like component in Nd–Hf, Nd–Pb and Sr–Pb, but not in Pb–Pb isotope spaces because the Pb isotopes are dominantly controlled by the high U/Pb component derived from the subducted Pacific oceanic slab. Low Th/U melt generated by recycling of marine carbonates, rather than the subduction‐related enriched mantle (EM2), signals the emplacement of the Hainan Plume at ~25 Ma. Radiogenic Hf in the pre‐existing ancient sub‐continental lithospheric mantle beneath the Cathaysia Block was greatly depleted by early‐stage magmatism influenced by the high U/Pb component. Hence, late Cenozoic basalts associated with the carbonatitic melts display contrasting Nd–Hf isotope covariations, with the Red River–Zhongnan Fault System as a dividing line, implying that the East and Southwest sub‐basins have been developed on the Cathaysia and Indochina Blocks respectively.

中文翻译：

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南海新生代玄武岩熔体来源的俯冲洋壳和海南羽指纹图谱

从南海构造域中发现的新生代玄武岩的地球化学数据汇编显示，Nd–Hf，Nd–Pb和Sr–Pb的震源区状成分的影响向西减弱，但在Pb–Pb同位素空间中却没有。铅同位素主要由俯冲太平洋板块中的高U / Pb组分控制。海洋碳酸盐的回收而不是俯冲相关的富集地幔（EM2）产生的低Th / U熔体标志着海南羽流在〜25 Ma的位置。华夏地块下已存在的古代次大陆岩石圈地幔中的放射性genic元素，由于受高铀/铅元素的影响，被早期岩浆活动所耗尽。因此，与碳酸盐岩熔体相关的新生代玄武岩显示出相反的Nd-Hf同位素协变，