Identifying the Initiation and Tectono‐Geomorphic Evolution of the Pamir‐Southwestern Tian Shan Intracontinental Convergent Zone: A Case Study of Late Cenozoic Stratigraphic and Source‐to‐Sink Analyses of the Qiate Section

The collision and convergence between the Indian and Eurasian plates have induced significant intracontinental deformation, leading to convergence between the Pamir salient and the Southwestern Tian Shan during the Cenozoic. Key indicators for identifying the initiation of continent–continent collision include sedimentary dispersal exchange, superimposed thrust faults and lithospheric mantle contact. In this study, we conduct comprehensive stratigraphic and detrital zircon analyses of Late Cenozoic sediments in the eastern Pamir–Southwestern Tian Shan convergent zone to understand the tectono‐geomorphic evolution and identify the first instance of sedimentary dispersal exchange between the two tectonic domains. Our analyses reveal an upward‐coarsening sequence from the Keziluoyi Formation to the Anjuan Formation, followed by an upward‐fining sequence from the Anjuan Formation to the Pakabulake Formation in the Qiate section. Sedimentary facies interpretations indicate a shift from lacustrine delta deposits and alluvial plain deposits to shallow lacustrine deposits in the Qiate section. The presence of these distal deposits suggests that the study area exhibited a flat topography and relatively weak hydrodynamic conditions, supporting the idea that the Alai Valley–Western Tarim Basin closed progressively from west to east. Detrital zircon U‐Pb dating and reanalysis of the Late Cenozoic sediments in three sections suggest that the first instance of sedimentary dispersal exchange occurred no later than the deposition of the Anjuan Formation, marking an Eocene–Miocene initiation of the Pamir–Southwestern Tian Shan convergence. By integrating these findings with previous studies, we conclude that the present‐day west‐to‐east drainage system in the convergent zone was not established until the Late Miocene to Pliocene. We also find that the sedimentary dispersal exchange is a more sensitive indicator for identifying the initiation of the Pamir–Southwestern Tian Shan intracontinental convergence than the initial superimposed thrust faults and lithospheric mantle contact.