Detrital zircon U‐Pb geochronology of the Jianchuan Basin, southeastern Tibetan Plateau, and its implications for tectonic and paleodrainage evolution
Ying Feng, Chunhui Song, Pengju He, Qingquan Meng, Qiaoxin Wang, Xinghong Wang, Wenqi Chen
Abstract
Abstract The Jianchuan Basin is a key region for determining the spatial‐temporal evolution of paleodrainage and tectonic at the southeastern Tibetan Plateau. New detrital zircon U‐Pb geochronology and paleocurrent data from Eocene formations in this basin suggest that the sediment sources switched from the remote sources (including Hoh‐Xil, Songpan‐Ganzi, North Qiangtang, Yidun and western Yangtze terranes) to local lithologies (adjacent Triassic and Eocene igneous rocks and western Yangtze block) from the early‐middle Eocene Baoxiangsi to the late Eocene Shuanghe and Jianchuan Formations. Such provenance changes support that large‐scale drainage reorganization occurred in the late Eocene (prior to ~36 Ma). This significant late Eocene provenance and drainage changes occurred as one of the responses to coeval topographic uplift in the southeastern Tibetan Plateau.