LAUSR

The development of the Red River is closely related to the topographic changes in East Asia, but the evolution of this drainage system remains unclear. We determined Pb isotopic compositions of detrital K‐feldspars from the Yinggehai‐Song Hong Basin to understand the sedimentary provenance and to test models of drainage patterns in East Asia. The Pb isotopic data show that detritus in the northern basin was mainly derived from the Red River system since the late Oligocene, and that the Red River achieved its present state in the late Miocene (~10.5 Ma). The variable provenance over time suggests that the Red River was probably connected to the Middle Yangtze and Mekong Rivers before the Miocene, and lost these headwater areas in the middle and late Miocene, respectively. The drainage reorganization probably occurred in response to rapid surface uplift of eastern Tibetan Plateau.