Late Quaternary Slip Rate and Kinematics of the Baoertu Fault, Constrained by 10Be Exposure Ages of Displaced Surfaces within Eastern Tian Shan

Abstract

Investigation on the kinematics and deformation rates about active fault interior of the Tian Shan can provide significant information for strengthening our understanding on the present tectonic evolution of this range. The Baoertu Fault (BETF) is a major E-W striking active structure within the eastern Tian Shan and separates the south and central Tian Shan. But its kinematics and slip rates in the late Quaternary have never been systematically reported before. Based on interpretations of remote sensing images, drone photography, and detailed field investigations, we propose that the BETF is characterized by left-lateral strike-slip faulting with a thrust component and provides the first late Pleistocene slip rate for this fault. At the northern margin of the Kumishi Basin, combining offset reconstructions of displaced alluvial fan surfaces with the terrestrial cosmogenic nuclide (TCN) exposure age dating, we calculate an average sinistral slip rate of 0.65±0.16 mm/yr and average vertical slip rate of 0.07±0.01 mm/yr for the BETF since 95-106 ka. The differential movement eastward between the central Tian Shan block and Yanqi-Kumishi Basin block is likely the dominant driver of the left-lateral slip of the BETF. Synthesizing other quantitative data in eastern Tian Shan, we suggest that the hinterland active faults or folds, including the BEFT, roughly accommodate ~28-45% of the total N-S convergence across the eastern Tian Shan.

Review on the Application of Airborne LiDAR in Active Tectonics of China: Dushanzi Reverse Fault in the Northern Tian Shan

“…Structure from Motion (SfM), another technology of aerial photogrammetry, has developed rapidly due to its advantages of low cost, high flexibility and the ability of quickly acquiring highprecision 3D topographical data (Klinger et al, 2011). Especially in the arid areas or areas after crop harvesting or wilting, the point cloud data generated by the UAV-SfM technology can also accurately reflect the surface features (bare earth) (Wu et al, 2019;Ren et al, 2021). Therefore, the UAV-SfM technology has been an important complementary to LiDAR.…”

Nonrigid Bookshelf Kinematics of Northeastern Tibet: Constrains from Fault Slip Rates around the Qinghai Lake and Chaka-Gonghe Basins

“…Highresolution digital elevation models (DEMs), derived from Structure-from-Motion (SfM), have improved our ability of identifying offset piercing lines significantly [44][45][46]. In northeastern Tibet, in situ cosmogenic nuclide 10 Be dating has been demonstrated as an effective method for determining the abandonment age of alluvial fan and terraces [47][48][49][50][51]. In this study, we obtain high-resolution DEMs from unmanned aerial vehicles (UAV), based on which we measure the horizontal and vertical offsets recorded on the faults using two self-developed MATLAB-based graphical user interfaces (GUIs)-"PointFit" and "FaultRecovery" tools.…”