Publication Date:
2019
Description:
〈span〉〈div〉Summary〈/div〉The activities of frontal thrusts in the northern Qilian Shan are critical for understanding the deformation of the Qilian Shan and the northeastern Tibetan Plateau. In this study, we estimate the slip rate of the active Fodongmiao–Hongyazi thrust along the northern margin of the Qilian Shan. High-resolution satellite imagery interpretations and detailed field investigations suggest that the fault displaced late Pleistocene terraces and formed fresh prominent north-facing fault scarps. To quantify the slip rate of the fault, we measured the displacements along the fault scarps using an unmanned aerial vehicle system and dated the displaced geomorphic surfaces using optically stimulated luminescence (OSL) and 〈sup〉14〈/sup〉C methods. The vertical slip rate of the fault is estimated at 1.0 ± 0.3 mm yr〈sup〉−1〈/sup〉 for the western segment. The slip rates for two branches in the eastern segment are 0.3 ± 0.1 mm yr〈sup〉−1〈/sup〉 and 0.6 ± 0.1 mm yr〈sup〉−1〈/sup〉. Using a fault dip of 40 ± 10〈sup〉o〈/sup〉, we constrain the corresponding shortening rates to 1.4 ± 0.5 mm yr〈sup〉−1〈/sup〉 and 1.2 ± 0.4 mm yr〈sup〉−1〈/sup〉, respectively. The rates are consistent with values over different timescales, which suggests steady rock uplift and north-eastward growth of the western Qilian Shan. Crustal shortening occurs mainly on the range-bounding frontal thrust.〈/span〉
Print ISSN:
2051-1965
Electronic ISSN:
1365-246X
Topics:
Geosciences
Published by
Oxford University Press
on behalf of
The Deutsche Geophysikalische Gesellschaft (DGG) and the Royal Astronomical Society (RAS).
