Abstract:Active faults within the block have the ability to trigger large earthquakes of magnitude 7 or above, and their spatial distribution characteristics, activity, and seismic risk cannot be ignored. The Litang fault zone is an important seismogenic structure in the Litang area of the western Sichuan plateau, which is distributed within the Sichuan- Yunnan block. There are still different understandings about the formation age of surface raptures in the Litang basin, the recurrence characteristics of paleoearthquakes, and the kinematic characteristics of the Litang fault. Based on remote sensing interpretation, field geological survey, unmanned aerial vehicle photogrammetry, paleoseismic trench exploration, and 14C dating, this paper has determined the spatial geometric distribution, activity, and paleoseismic history of the Litang fault. The research results indicate that the surface rapture of the Litang basin may be formed by the superposition of the 1948 Litang M71/4 earthquake and the 1729 Litang earthquake. The recurrence behavior of paleoearthquakes along the Litang fault conforms to the characteristics of cluster earthquakes, which is relatively similar to the recurrence characteristics of strong earthquakes along the Maoyaba fault, indicating that both faults may rapture simultaneously. The movement of the Litang fault is characterized by sinistral strike- slip with normal fault components, which is controlled not only by lateral extrusion movements on the southeastern margin of the Tibet Plateau, but also by differential movements of the Yajiang and Shangri- La secondary blocks. This study provides detailed information for understanding the seismic risk and tectonic deformation mechanism of active faults within the Sichuan- Yunnan block, as well as for planning, construction, and safe operation of major regional projects.