华南东部新生代陆内火山区的深部热/化学结构及火山成因机制

华南块体位于欧亚板块的东南部，自新生代以来经历了复杂的构造演化过程，其东部广泛分布了新生代陆内玄武岩及橄榄岩包体，因此成为研究岩石圈构造演化和陆内火山活动的绝佳窗口。前人的研究提出了大量用于解释华南东部新生代岩石圈演化和岩浆活动的模型，但这些模型往往存在较大的争议，且缺乏对于岩石圈及深部上地幔基本物质组成和现今热状态的深入研究，因此阻碍了我们进一步了解该区域的深部动力学过程。本项目聚焦华南东部新生代陆内火山区，拟利用地震面波、大地热流、绝对高程、大地水准和橄榄岩地球化学等多种观测数据联合概率反演方法，构建该区域岩石圈及深部上地幔的热/化学结构综合模型。重点关注其岩石圈厚度、温度结构、组分结构、熔体分布和熔融程度等问题，并深入研究岩石圈状态对于陆内火山活动的影响，为进一步探索华南东部岩石圈构造演化及陆内火山活动的形成机制提供新的视角。

South China Block (SCB), as the southeastern margin of the Eurasian plate, experienced complex tectonic evolution since the Cenozoic. During that time, Cenozoic intraplate basalts containing abundant mantle xenoliths are widely distributed in eastern SCB, thus providing a unique window into the lithospheric modification and intraplate volcanism. Although previous studies have proposed numerous models to explain these processes, controversy remains and no research focuses on the conversion of geophysical or geochemical observables into robust estimates of the true compositional and thermal structure of the inner Earth. These all obstruct our understanding of the deep geodynamics in eastern SCB. This project focus on the intraplate volcanism areas in eastern SCB. It is supposed to construct an integrated thermochemical model of the lithosphere and sub-lithospheric mantle beneath eastern SCB by using a probabilistic inversion method, which can jointly invert newly processed Rayleigh wave dispersion data, surface heat flow, absolute elevation, geoid anomalies and geochemist of mantle xenoliths. The final 3D model will be used to determine the lithosphere-asthenosphere boundary, thermal state, compositional structure, melting distribution and melting degrees of eastern SCB. Moreover, this thermochemical model can account for the potential links between mantle state and the compositional variations of continental intraplate basalts. This project will shed new light on the tectonic evolution of the lithosphere and the mechanisms of intraplate volcanism in eastern SCB.