Low-temperature thermochronology and its geological significance in the central and northern section of the western margin of the Ordos Basin

Abstract. The study of low-temperature thermochronology at plate edges provides favorable constraints for regional tectonic evolution and surface processes. Based on the existing thermochronological data of multiple cooling events since the Mesozoic era, we conducted apatite fission track and apatite (U-Th)/He studies on drilling samples from the middle and northern parts of the western margin of the Ordos Basin, revealing the uplift and cooling history and differences in the middle and northern parts of the western margin of the Ordos Basin. The new thermal history simulation results show that the Zhuozishan Mountain (Mt.) part experienced large-scale uplift in the Late Jurassic (160 Ma–150 Ma), slow uplift at 130 Ma–30 Ma, and severe uplift after 30 Ma; The Taole – Hengshanbao part began to uplift at 155 Ma–145 Ma, slowly uplifted at 145 Ma–30 Ma, and then violently uplifted; The Majiatan – Huianbao part experienced large-scale uplift at 158 Ma–137 Ma, with a slightly slower uplift rate at 137 Ma–110 Ma, and entered a severe uplift stage again at 70 Ma–50 Ma. The Late Jurassic tectonic uplift indicated by thermochronology corresponds to the formation of the western margin thrust fold structure, with the northern and southern sections starting earlier and the middle section starting slightly later. This is related to the different tectonic evolution and stress in their location, and the differences in uplift rate and time may be related to the impact of multiple Yanshanian orogeny on the region.