Research progress of Jiali fault activity

The Jiali fault is a large strike-slip fault that traverses the southeast of the Tibetan Plateau. It played an important role as an adjustment fault for adjusting stress balance both before and after the collision of the Indian and Eurasian plates. Based on early publications about the Jiali fault, this study systematically summarizes and analyzes its tectonic background, crustal and mantle structure, properties and rates of activity in the Late Quaternary and the present from the perspectives of geology and geophysics. Based on geological methods, we collected results related to dating in order to constrain the active age and rate of the fault. We newly tested optical stimulated luminescence dating for two areas near the Galong Temple, the northern branch of the eastern section of the Jiali fault to complement the measurement of activity rate. We compared the strike-slip rate and dislocation distance for different segments along the Jiali fault from west to east. Based on geophysical observations, we analyze the seismic activity, crustal and mantle velocity and seismic anisotropy. Using waveform modeling method, we newly determined focal mechanisms of 18 earthquakes with magnitudes between 3 and 5. We found that the current tectonic deformation of the Jiali fault is primarily the right-lateral strike-slip. However, there are different features at different segments. The newly activated Xixingla-Damu branch is the most active segment. On this basis, we discussed the tectonic evolution process of the Tibetan Plateau, and analyzed the structural stability of the eastern Himalaya syntaxis, which is needed for the geological hazard risk assessment of the Sichuan-Tibet railway engineering construction at the Yaan-Linzhi branch.