Geometry and kinematics of Mesozoic and Cenozoic structures in northern Tianshan foreland basin: insights from quantitative structural analysis of 2-D and 3-D seismic reflections and balanced restoration

• DOI: 10.5194/egusphere-egu23-5320
• Publication Date: 2023-02-22T17:46:35Z
• Authors: Zhenyu Peng; Xin Wang; Bruno Vendeville; Fabien Graveleau; Alan Nunns
• Keywords: Anticline; Neogene; Basement; Outcrop

In central Asia, the Tianshan mountains have undergone a series of subduction-collision-accretion processes during Paleozoic times that resulted in forming basement structures later reactivated Cenozoic rejuvenation range. northern Tianshan-South Junggar foreland basin, en échelon W-E / WNW-ESE folds constitute large-scale fold-and-thrust belt (FTB). Using recent industrial 2-D and 3-D seismic surveys carried out western area FTB, we analyzed outcropping (Dushanzi Xihu anticlines) buried (Gaoquan, Kadong, Kayindike, Dunan anticlines). Observing strike these changes from east to NW-SE west, investigated parameters controlled this lateral variation along FTB. We particularly structural kinematic relationships between deep Mesozoic shallow Neogene-Quaternary structures. support our investigation by using interpretation balanced restoration. Our results provide new insights into kinematical history Mesozoic-Cenozoic tectonic evolution record deformation propagation. first demonstrated sedimentary Triassic Jurassic is characterized NNW-SSE strike-slip faults development pull-apart restraining bend systems. These features were partially contractional deformation, depending on their position relative mountain front. Second, quantified about 7 km total S-N shortening has been accommodated across also displacement rate every single structure. It ~0.13-0.2 mm/yr Gaoquan anticline since Quaternary, ~0.19-0.30 ~0.36 Dushanzi Pliocene ~0.30-1.2 Xihu, Kadong Kayindike anticlines Quaternary times. Additionally, thrusting above 3 6 lower than inactive anticlines. This suggests reactivation fault zone partitioned strain Finally, integrate model FTB illustrates spatial pattern at depth. Notably, it emphasizes how exerted primary control growth thrust-related localizing nucleation thrust ramps compression. vs. interaction might be applied some other areas basin.