Carboniferous–Permian transgression/regression mechanisms in the Eastern Ordos Basin and their sea-level spatiotemporal variability: Insights from source-to-sink systems

Developed on the North China Craton, intracratonic Ordos Basin contains a complete Paleozoic-to-Cenozoic sediment record, allowing for long-term paleoenvironmental and climate change investigation. During Carboniferous–Permian period, convergence between block paleo-Yangtze plate to south resulted in general marine regression characterized by series of second-order transgression/regression cycles diachronous along eastern margin Ordos. However, detailed mechanisms that induced these cycles, as well associated paleoecological changes, remain unknown. In this study, we integrate multiple indices, including δ18O δ13C, rare earth element (REE), paleontological assemblages, clay content (w (chlorite + kaolinite)/w((Illite) ratio) planar distribution, restore paleo-water depth distribution. These parameters are then used reconstruct paleo-sea level from Pennsylvanian middle Permian. We conclude direction was mainly toward east during Pennsylvanian–early Permian switched clockwise north suggest space time, linked local variations supply regional uplift. Using detrital zircon U–Pb data REE trace heavy mineral assemblages (HMA), estimate provenance area. The volumes deposited basin through time obtained using 2D seismic data. Carboniferous, coarse-grained sediments were derived uplifting Helan Mountain (Qiandam–Qilian orogenic belt). By Permian, material became multi-sourced, thus issuing Yinshan range Qinling south. description numerous core samples with electric log facies associations across first-order Carboniferous tidal flat depositional system prograding fluvial delta system. According transfer glacial epoch, sedimentation rate, rate above, classify evolution process into three patterns: low-transgression less-sediment pattern (the late Carboniferous), high mass early Permian), low Sakmarian stage). Lastly, quantitative calculation source-to-sink (S2S) parameters, S2S volume elevated height uplift data, propose mechanism Basin, responding above s. first controlled uplift, whereas second supply. As third one, could affect process.