Abstract:S-wave velocity structures are revealed using double-difference tomography, which shows large-scale low-velocity anomalies around the Xiaojiang and Lijiang-Xiaojinhe fault zones at 10-25 km depth. In contrast, an obvious high-speed anomaly exists in the center of Emeishan area, which is consistent with the Emeishan Large Igneous province. Combined with the geological and geophysical data, the low-velocity anomaly might relate to the lower crustal flow of central Tibetan Plateau. The high-velocity anomaly associated with mantle plume in Emeishan would obstruct the crustal flow and limit it around the large deep faults. Meanwhile, the results also show that many mineral resources are mainly concentrated on the major faults and low-velocity zones, indicating that the lower crustal flow and the large deep faults provide conditions for mineral fluids and minerals deposit.

Key words: Yunnan Province; seismic wave tomography; lower crustal flow; metallogenic environment