Post-Triassic multiple exhumation of the Taihang Mountains revealed via low-T thermochronology: Implications for the paleo-geomorphologic reconstruction of the North China Craton

Abstract

To better define the uplift and denudation process of the Taihang Mountains and its uplift–subsidence coupling with the western Bohai Bay Basin, the zircon and apatite (U-Th)/He thermochronology and apatite fission track thermochronology of samples from the Taihang Mountains, Trans–North China Orogen, were examined in this study. The weighted averages of single–grain zircon and apatite (U-Th)/He ages were 70.3–79.9Ma and 15.1–26.8Ma, respectively. The apatite fission track ages ranged from 41.8Ma to 51.9Ma, with mean track lengths of ~11.68–13.3μm. Three distinct episodes of cooling, at 100–45Ma, at 38–30Ma, and after ~20Ma, revealed via joint inverse modeling, were related to compression from the subduction of the Kula Plate during the Late Cretaceous, the rapidly changing differential elevation and subsidence between the Taihang Mountains and the western Bohai Bay Basin from the late Eocene to Early Oligocene, and the combined distant effects of the collision of the Indian and Eurasian plates and the rollback of the subducting Pacific Plate during Late Cenozoic, respectively. This paper presents the cooling histories of the shallow crust below ~200°C in the Taihang Mountains and provides new insights into the geodynamic mechanism of the uplift events that occurred in the different areas of the North China Craton. Understanding these events is very important to comprehend the differential uplift in the North China Craton, basin–mountain coupling, and its tectonic–morphological evolution since the Mesozoic.