克拉通或典型地盾下方过渡带的深部结构是否接近于全球标准模型存有争议。扬子地块作为我国元古宙克拉通的典型代表，关于其过渡带的深部结构的认识也缺乏详细的认识。层析成像研究显示其过渡带有明显的地震波高速异常，且其内部横向变化非常强烈。然而接收函数研究则表明其地幔间断面埋深接近于全球标准模型，暗示过渡带内无明显的低温异常。分歧的原因在于扬子克拉通尚缺乏大规模的天然地震观测研究，因而对其上地幔过渡带深部结构的分辨较低。本项目将充分利用中国地震局固定台网，已有的流动台阵，以及最新启动的中国科学台阵探测项目流动台阵的观测资料，开展三重震相剖面波形模拟获取研究区过渡带的P波和S波速度结构，为研究扬子与周边青藏高原和华北块体的相互作用及动力学演化模式提供较为可靠的地震学证据。其次，结合印度地盾等已有观测资料，获取稳定大陆下方过渡带深部结构共同特征。

Up to now, seismic studies related to the deep structure in the upper mantle transition zone (TZ) beneath craton or sheild are relatively poor. For example for Yangtze craton, there are highly debated about different patterns, which are proposed to explain the different seismic observations. Unlike to deep structure under other typical cratons, Many seismic tomography studies indicate both high P-wave (Vp) and S-wave (Vs) anomalies in the upper mantle transition zone (TZ) beneath Yangtz craton, which is also characterized with strong lateral TZ variations. However, both upper mantle discontinuities at 410 and 660 km under Yangtze craton seem close to the average value of the global IASP91 model mapped by migrated receive function. To resolve the differences, we constrain the TZ structure both in Vp and Vs under Yangtz craton by using seismic profiles of triplicated waveforms. The triplication modeling can not only map the lateral variation of the discontinuities at 410 and 660 km, but also present the detailed seismic TZ velocity structure. Data are collected by Chinese regional networks, portable seismic array which have finished or just deployed recently in the project of Chinese seismic arrays deployed by Chinese Earthquake Administration (CEA). A straightforward comparison of Vs and Vp structures from same earthquakes can offer reliable constrains and aid in the discrimination between thermal and compositional heterogeneity, thus exploring seismic evidence for dynamic process involved in Yangtz craton.