Geometry, kinematics and morphotectonics of the Yanqing–Huailai active faults (northern China)

• Published in: Tectonophysics Vol. 308; no. 1; pp. 99 - 118
• Main Authors: Pavlides, Spyros B, Zouros, Nikos C, Zhongjing, Fang, Shaoping, Cheng, Tranos, Markos D, Chatzipetros, Alexandros A
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 10.07.1999
• Subjects: active faults; extensional tectonics; north China seismotectonics; palaeoseismology; Shanxi Rift System; north China seismotectonics; extensional tectonics; palaeoseismology; active faults; Shanxi Rift System
• ISSN: 0040-1951; 1879-3266
• DOI: 10.1016/S0040-1951(99)00074-8

Field studies along the Huailai and Yanqing mutually parallel neotectonic fault zones lead to a description of morphotectonics and palaeoseismicity, as well as the geometry and segmentation of these structures. The study emphasizes the kinematics of the region. The faults belong to the tectonic interaction between the Shanxi rift system and the North China fault system. Although the general strike of the zones is NE–SW, the Yanqing fault is divided into five segments of NNE–SSW, ENE–WSW and E–W trends, and the Huailai fault into three segments of ENE–WSW and E–W trends. They are mainly pure dip-slip normal faults, while less often they show oblique-slip components. The mesostructural quantitative palaeostress analyses (local neotectonic–active stress pattern) indicate a regional NNW–SSE-oriented extension ( σ 3), locally deviated to N–S, NW–SE, WNW–ESE, depending on the fault segment strike. The great deviation of fault strikes from the mean and their relation with the basement joint and thrust systems lead to the hypothesis that the neotectonic faults, which have a capacity for strong earthquakes, follow pre-existing inherited structures.