Late Cretaceous Sedimentology and Provenance of the Taining Basin in South China: Implications for the Basin–Range System and Regional Palaeogeography

Tectonics-topography-climate coupling regulates surface processes across East Asia, yet the role of Palaeo-Pacific subduction in shaping Cretaceous palaeogeography remains debated. Here we reconstruct the early Late Cretaceous source-to-sink system and palaeogeography of the Taining Basin (western Cathaysia Block, South China) by integrating sedimentary facies, palaeocurrents, clast compositions, and detrital zircon U-Pb geochronology from the Shaxian and Chong'an formations. Thirteen lithofacies are recognised and grouped into alluvial fan, fluvial, and floodplain facies associations. The Shaxian Formation records a retrogradational alluvial fan system, whereas the overlying Chong'an Formation is dominated by alluvial fan deposits with subordinate fluvial and floodplain deposits. Provenance signals indicate short transport distances and proximal north-northwest uplifts associated with the northern Wuyi terrane. Stratigraphic architecture and provenance patterns support half-graben development and basinward progradation during back-arc extension driven by Palaeo-Pacific slab rollback. Regionally, along-strike differentiation in Basin-Range system within the Cathaysia Block is proposed: western Cathaysia Block is characterised by Early Palaeozoic granitic ranges and extensional basins, whereas eastern Cathaysia Block is dominated by Early Cretaceous granitic/volcanic ranges and basins. Sparse Mesozoic detrital zircon input and south-southeast palaeoflow indicators argue against prominent Late Cretaceous coastal mountains; major coastal uplift more likely peaked during the late Early Cretaceous.