Evolution of Cretaceous Sediment Provenance in the Danxia Basin, Southeast China: Implications for Tectonic and Landscape Reorganization in Cathaysia

Abstract Understanding how tectonic uplift and drainage reorganization controlled sediment dispersal during the Cretaceous is critical for reconstructing the topographic evolution of southeast China. This study examines how sediment sources and routing systems evolved during the Cretaceous, using the Danxia Basin as a key archive and adjacent basins for regional comparison. We integrate sedimentological observations, detrital zircon U‐Pb‐Hf isotopic data, whole‐rock Pb isotope geochemistry and source unmixing results from the Danxia Basin deposits, together with published Jurassic to Paleogene zircon age data sets from nine adjacent basins. The results reveal a regional provenance shift from dominant northern cratonic sources (North China and Yangtze blocks) during the Jurassic to increasing Cathaysian sources during the Cretaceous, including the Wuyishan and Yunkai terranes and the Nanling Tectonic Belt. Within the Danxia Basin, Cretaceous lithologies record a two‐stage provenance evolution: Early Cretaceous sediments mainly derived from the Wuyishan Terrane, whereas Late Cretaceous deposits show mixed input from the Yunkai Terrane, Nanling Tectonic Belt and Wuyishan Terrane, reflecting drainage expansion and/or sediment‐routing reorganization. Published thermochronological data indicate enhanced uplift and exhumation in the Yunkai Terrane and Nanling regions during the Late Cretaceous, driving increased sediment flux to both inland and coastal basins. During the Paleocene‐Eocene, sediment supply became increasingly dominated by the Nanling region as exhumation in Yunkai region waned. These observations support a dynamic “seesaw” topographic model, in which alternating uplift of northern cratonic and eastern Cathaysian source regions governed sediment dispersal, basin architecture and paleoenvironmental evolution across southeast China.