Focused Mantle Upwelling Beneath the Southeastern Asian Basalt Province Revealed by Seismic Surface Wave Tomography
Focused Mantle Upwelling Beneath the Southeastern Asian Basalt Province Revealed by Seismic Surface Wave Tomography
复制标题
DOI：
10.1029/2023gl104336
复制
发表时间：
2024-01
影响因子：
5.2
通讯作者：
Xing-Zhao Fan;Zhen Guo;Ling Chen;Qi-fu Chen;Ting Yang;Chuntao Liang
中科院分区：
文献类型：
--
作者：
Xing-Zhao Fan;Zhen Guo;Ling Chen;Qi-fu Chen;Ting Yang;Chuntao Liang
随着南海盆地海底扩张的结束，在中南地块、南海盆地和雷琼地区广泛发育了丰富的板内火山活动，形成了东南亚玄武岩省（SABP）。SABP的地球动力学起源长期以来一直是谜和争论。在这里，我们提出了一个高分辨率的3-D上地幔S波速度模型在该地区进行地震为基础的面波层析成像与东南亚各地收集的地震数据。由此产生的图像描绘了SABP中心区域下方的羽状结构，其特征在于上地幔中的连续，近垂直的低速柱。我们的新发现，结合以前的地球化学和地球动力学证据，表明SABP内广泛的后扩张板内火山活动可能是由这种集中的地幔上涌引起的，这可以进一步追溯到现有的全球速度模型推断的核幔边界。
Following the termination of seafloor spreading in the South China Sea (SCS) basin, abundant intraplate volcanism widely spreads in the Indochina block, SCS basin, and Leiqiong area, forming the Southeastern Asian Basalt Province (SABP). The geodynamic origin of the SABP has long been enigmatic and debated. Here, we present a high‐resolution 3‐D upper mantle S‐wave velocity model in the region by conducting earthquake‐based surface wave tomography with seismic data collected across Southeast Asia. The resultant images depict a plume‐like structure beneath the central area of the SABP, characterized by a continuous, sub‐vertical low‐velocity column in the upper mantle. Our new findings, combined with previous geochemical and geodynamic evidence, suggest that the extensive post‐spreading intraplate volcanism within the SABP is likely induced by this focused mantle upwelling, which could be further traced down to the core‐mantle boundary as inferred by existing global velocity models.