Neogene birth of the Yangtze River: a synthesis of zircon U-Pb provenance data

The evolution of the Yangtze River is key to deciphering tectonic-climate-geomorphology coupling in East Asia, yet its integration age, whether Eocene, Miocene, or Quaternary, remains hotly contested. To constrain the timing of final Yangtze River integration, this study compiles 11,346 Phanerozoic zircon U-Pb ages from the Yangtze catchment, spanning multiple basins, orogenic belts, and modern river sediments. The results reveal that the diagnostic 45–35 Ma zircon U-Pb age peak from the upper reaches is absent from Paleogene strata in the middle-lower reaches, indicating that detritus from the upper Yangtze River had not yet reached the lower reaches during the Paleogene. However, Neogene strata in the Jianghan (25–18 Ma) and the East China Sea basins (20–10 Ma) show, for the first time, characteristic age peaks at 40–32, 20, and 18–16 Ma, which can be traced back to bedrock sources in the Jinsha and Dadu river catchments. These findings establish that the Yangtze River achieved its final integration during the Early Miocene, refuting Eocene and Quaternary models. Neogene fault reactivation (20–10 Ma) and monsoon intensification along the southeastern Tibetan Plateau generated the topographic relief and hydraulic power that drove river incision and transcontinental sediment routing.