Strain Partitioning and Strike‐Slip Faulting in the Nanjieshan, North Tibetan Foreland: Progressive Widening of the Altyn Tagh Fault System With Implications for Regional Earthquake Hazards

作者：Haibo Yang, Daoxiu Lin, Xiaoping Yang, Dickson Cunningham, Zongkai Hu, Xiongnan Huang, Yingfeng Zhang, Li A · 发表于：Tectonics · 年份：2024 · DOI：10.1029/2024tc008262 · 被引用次数：5 · 研究领域：earthquake and tectonic studies、Geology and Paleoclimatology Research、Geological and Geochemical Analysis

Abstract Large continental strike‐slip fault systems typically comprise a principal displacement zone and subordinate splay faults, exhibiting complex geometries, connectivity, and kinematics. Understanding the three‐dimensional arrangement of major and minor faults is important for determining strain distribution, landform development, and potential earthquake behavior. This study examines the Quaternary deformation, fault kinematics, and late Holocene ruptures along the Nanjieshan Fault system (NJSF), a major branch of the Altyn Tagh Fault (ATF) system in the North Tibetan Foreland. The E‐W‐trending NJSF comprises a principal strike‐slip fault flanked by two thrust faults, forming a regional, sinistral positive flower structure. Cosmogenic exposure dating, field data and remote sensing observations indicate that the strike‐slip rate of the main NJSF is ∼0.5 mm/a since ∼45 ka, consistent with the low slip rates observed on other faults northwest of the ATF. Paleoseismological trenches reveal three surface‐rupturing events on the NJSF in the last 2,500 years that may coincide temporally with the last two major earthquakes documented on the principal ATF, suggesting quasi‐simultaneous rupture behavior. Coulomb stress change modeling indicates that a future ATF earthquake is unlikely to trigger failure along the NJSF. Conversely, rupture of the NJSF could induce stress loading on the ATF, potentially bringing it to failure. A synchronous rupture on the ATF and its major branch ...