T21A-2801
Northeastward growth of the Tibetan Plateau along the Tibet-Ordos transition zone-revealed from Liupanshan deep seismic reflection profile

Tuesday, 15 December 2015
Poster Hall (Moscone South)
Rui Gao1, Haiyan Wang1, Xiaoyu Guo1, Wenhui Li1, Hongqiang Li1, Hesheng Hou1, Xiaosong Xiong1, Xiao Xu1, Hongda Liang1 and Qiusheng Li2, (1)CAGS Chinese Academy of Geological Sciences, Beijing, China, (2)Institute of Geology, Chinese Academy of Geological Sciences, Beijing, China
Abstract:
Most previous studies of the Tibetan Plateau have focused on the processes of crustal thickening and subsequent lateral extrusion to account for the outward growth of the plateau. However, lithospheric structure across the tectonic boundaries of the Tibetan Plateau has not yet been fully imaged and, therefore, how geological structures evolved in association with the lateral expansion of the northeastern margin in particular remains unclear. Here, together with interpretation of regional geological and geophysical data, we employ a recently acquired 165 km-long deep seismic reflection image that crosses the Liupan shan (Fig. 1) northeastern flank of the Tibetan Plateau to show that crustal shortening, structural integrity, and topographic relief are strongly correlated. The resulting stratigraphic “architecture” suggests that crustal shortening is a primary driver for plateau uplift and expansion of northeastern Tibet and decoupled crustal deformation owing to differential structural integrity is accommodated during the subsequent northeastward growth of the plateau.

Figure 1.Showing the seismic reflection line location and the topographic relief of the northeastern Tibetan Plateau and the western Ordos basin (KF: Kunlun Fault; LP Shan: Liupan Shan; HF: Haiyuan Fault; YTSF: Yangtongshan Fault; NSS-LSF: Niushou Shan-Luoshan Fault)XG Shan: Xiaoguan Shan; YJD: Yanjiadian Diorite; GS: Guanshan Shan; CCP: Caochuanpu; LS Complex: Longshan Complex)