High‐resolution body wave tomography models of the upper mantle beneath eastern China and the adjacent areas

摘要: [1] We present new 3-D tomographic models of VP, VS and VP/VSratio anomalies in the upper mantle beneath EC adjacent areas. This data was collected interpreted with goal clarifying geodynamic processes that caused spatially variable event histories throughout Eastern China (EC) during Mesozoic to Cenozoic time. The images were constructed by inverting body wave travel-times recorded at ∼1300 stations within upgraded National Seismic Network, 9 temporary arrays. Resolution tests for different depths featured velocity verify capture heterogeneities 700 km. salient features can be clearly identified. These include strong multiscale occupying differences spatial scale found northern southern areas EC. demonstrate a degree variability evolution We propose two mechanisms explain these patterns. First, western front subducted slab may have imparted greater horizontal compressional stress where it impinged further eastward into would experience stronger convection an altered regime mantle, creating significant thermal South Block (SCB) relative eastern North Craton (NCC). Second, differing states viscosities NCC Cathaysia (CaB) resulted responses regional deformation. Archean hinterland specifically has colder state higher viscosity, therefore exhibits only small-scale due effect shear localization. Neoproterozoic CaB relatively warm lower thus deformed more continuously.