Normal Faults and Tectonic Model of the Bamei‐Kangding Segment Within the Southern Xianshuihe Fault Zone in Eastern Tibet

Abstract The left‐lateral strike‐slip Xianshuihe fault (XSHF) located in the eastern Tibetan Plateau is considered one of the most tectonically active intra‐continental faults in China. Despite extensive research on the XSHF, the detailed late Quaternary slip rates of secondary faults and mechanisms for significant normal faulting observed within the Bamei‐Kangding segment remain poorly understood. Through integrated analysis of satellite imagery, field surveys, and small Unmanned Aerial Vehicle photogrammetry‐derived Digital Elevation Models, coupled with multiple dating methods ( 10 Be Terrestrial Cosmogenic Nuclide and Optically Stimulated Luminescence) to date moraines offset by the faults, we reveal a unique tectonic setting where the left‐stepping NW Xianshuihe fault and Moxi fault create a releasing stepover that accommodates right‐stepping secondary faults and explains normal faulting. The 24‐km‐long Mugecuo fault is characterized by two primary branches (southern and northern), with sinistral slip rates of 1.2 ± 0.1 mm/yr and 1.1 ± 0.1 mm/yr, and vertical slip rates of 0.1 mm/yr and 0.8 ± 0.1 mm/yr, respectively. The Zheduotang fault exhibits distinct segmentation with its northwestern segment showing a higher sinistral slip rate of 6.7 ± 1.4 mm/yr compared to its southeastern segment. These newly constrained slip rates indicate a strike‐slip‐dominated system with subordinate normal faulting and progressive strain migration toward a more geometrically smooth configuration. The secondary faults vertically connect to form a negative flower structure, elevating cascading rupture potential. Fresh scarps along the Mugecuo fault may be related to the 1725 M 7.0 Kangding earthquake, highlighting significant seismic hazard implications for this region.