The thermal history of the Qinshui Basin has been studied by using the fission-track analysis of apatite and zircon, integrated analysis of tectonic evolution, magmatic activity and other palaeogeothermal analysis data. Results indicate that the palaeogeothermal gradient between the late-Paleozoic era and the medium-Mesozoic era is relatively low and the palaeogeothermal gradient in the late-Mesozoic is up to 5.56 °C/100 m in the middle, and the values are relatively higher in the north and south margins of the basin, reaching over 8.00 °C/100 m, which indicates that there was an anomalous tectonic thermal event in the thermal history of Qinshui Basin. This event happened in 110–140 Ma, and the main peak value was between 120 and 140 Ma. This anomalous tectonic thermal event is controlled by the strengthening thermal mobility of the lithosphere and magmatic intrusion. The maturity of the Permo-Carboniferous coal series mainly was controlled by this anomalous thermal field. The apatite fission track date of samples across the basin shows that a rapid tectonic uplifting with cooling existed 26.2–11.5 Ma ago and the upliftings in the north and south of the basin happened earlier than that in the middle. The Permo-Carboniferous strata had been completely annealed in the early 50 Ma, palaeotemperature over 125 °C. Since then, especially from Oligocene-Miocene epoch, the strata which experienced large-scale tectonic upliftings with rapid cooling have been kept out of the annealing belt (70–125 °C) in a relative low temperature environment. The late Mesozoic tectonic thermal event control hydrocarbon production peak (late Jurassic to early Cretaceous period) of Permo-Carboniferous strata in Qinshui Basin. When the strata experienced upliftings with rapid cooling since Oligocene-Miocene epoch, the hydrocarbon generation of coal series had stopped.

The Ordos Basin located in the Western North China Craton (WNCC) has been confirmed to have undergone large-scale lithospheric thinning at the end of the Early Cretaceous (130 ~ 90 Ma), but investigations involving its lithospheric thermal structure in the Mesozoic and Cenozoic are limited. In this study, we employed a 1D, steady-state, heat conduction equation to calculate mantle heat flow and its partitioning, the Moho temperature and the thermal lithospheric thickness of different tectonic units in the Ordos Basin based on an analysis of thermal history reconstruction and crustal layering models. The results suggest that the peak of mantle heat flow at the end of the Early Cretaceous varied between 46.65 mW/m² and 62.97 mW/m², far exceeding 50% of surface heat flow, which shows a typical ‘hot mantle and cold crust’ type of lithospheric thermal structure, and the lithospheric thinning reached a minimum thickness of 50 ~ 75 km. This was followed by a thermal decay phase in the Late Cretaceous, and a significant vertical thickening of lithosphere occurred during this period, during which the lithospheric thickness increased to 78 ~ 133 km by the end of the Late Cretaceous. Since the Cenozoic, the ratio of mantle to surface heat flow gradually declined to less than or close to 50%. At present, the average mantle heat flow in the Ordos Basin ranges from 22.10 mW/m² to 38.76 mW/m², the lithospheric thickness is between 81 ~ 158 km, and the Moho temperature entirely surpasses 600°C. In addition, we discuss potential factors and uncertainties in the thermal structure calculation. Combined with previous studies, we suggest that the lithosphere in the WNCC has been thinned locally due to asthenosphere upwelling. Graphical abstract