Quaternary Activity Characteristics of the Yiong-Zayu Segment of the Jiali Fault Zone
Lu Shiming
Wu Zhonghai
Han Shuai
Hu Yuan
Fan Fuxin
Abstract：The Jiali Fault Zone is one of the major active tectonic structures along the southeastern margin of the Tibetan Plateau,playing a crucial role in regional seismicity and geomorphic evolution.This study systematically analyzes the tectonic activity of the Yiong-Zayu segment of the Jiali Fault Zone by integrating high-resolution remote sensing imagery,DEM data,field investigations,and focal mechanism solutions.The results indicate that the Jiali Fault Zone has exhibited weak tectonic activity since the Quaternary,with no significant evidence of right-lateral strike-slip motion.Instead,localized NW-and nearly E-W-trending normal faulting has been observed along certain segments,and seismic activity is predominantly characterized by local normal-faulting earthquakes.GPS velocity analysis reveals that the fault exhibits low horizontal slip rates,with deformation primarily characterized by extension,suggesting that it does not function as a major boundary fault.By integrating previous studies,we further infer that the formation of local normal faults is primarily influenced by localized shear stress or post-glacial rebound.Moreover,the kinematic model of southeastern Tibet is more consistent with a clockwise rotational extrusion mechanism.
Keywords：Jiali Fault ZoneTibetan Plateautectonic geomorphologynormal faultclockwise rotational extrusion modeltectonics
Publication Date：2025-08-30
Pages：18( 3052-3069 )