Late Quaternary steady deformation of the Minle Fault in the north Qilian Shan, NE Tibet

• Published in: Tectonophysics 2021-05, Vol.807, p.228775, Article 228775
• Main Authors: Liu, Qingri, Li, Youli, Xiong, Jianguo, Zhang, Huiping, Ge, Weipeng, Zhao, Xudong, Huang, Feipeng, Hu, Xiu, Zhong, Yuezhi, Xin, Weilin
• Format: Article
• Language: English
• Subjects: Aerial photography; Basins; Cenozoic; Deformation; Digital Elevation Models; Holocene; Late Quaternary; Minle Fault; North Qilian Shan; Photogrammetry; Quaternary; Steady deformation; Tectonics; Terraces; Unmanned aerial vehicles; Zhangye Basin
• ISSN: 0040-1951; 1879-3266
• DOI: 10.1016/j.tecto.2021.228775

The Qilian Shan, located in the northeastern Tibetan Plateau, has been continuously extending to the foreland since the late Cenozoic, resulting in the deformation of the Hexi Corridor Basins. Five terraces of the Hongshui River are faulted in the southern Zhangye Basin, a sub-basin of the Hexi Corridor, documenting the tectonic history of the Minle Fault since the late Quaternary. In this study, a high precision digital elevation model (DEM) generated by unmanned aerial vehicle (UAV) photogrammetry is used to obtain the cumulative vertical offset of each terrace. And the abandonment ages of terraces are dated by AMS 14C dating. The results show that the Minle Fault has produced an almost constant shortening rate of 0.95 ± 0.30 mm/a since 42.3 ± 0.5 ka, and has been active throughout the Holocene. The shortening rate of the Minle Fault could represent the deformation rate in the south margin of the Zhangye Basin. Geological and geodetic data indicate the shortening rates of the Zhangye Basin are steady in 104 and 10-year timescales. The deformation rate of the north Qilian fault-fold system (NQF) has not changed significantly since the late Quaternary and may be consistent with that in the 106-year timescale, although further studies are needed. •Steady shortening rate of the Minle Fault since the late Pleistocene has been estimated to be 0.95 ± 0.30 mm/a.•Shortening rates of the Zhangye Basin are steady in 104 and 10-year timescales according to geological and geodetic data.•The deformation rate in the north Qilian Shan has not changed significantly since the late Quaternary.