Formation of the Yangtze Three Gorges: Insights from detrital apatite fission-track dating of sediments from the Jianghan Basin

The establishment of the course of the modern Yangtze River is a topic of ongoing debate, with the formation of the Three Gorges, incised in the Huangling Massif, representing the key event under discussion. Downstream of the Three Gorges, the Cenozoic succession of the Jianghan Basin has been investigated to detect the moment of incision into the Three Gorges. Detrital apatite fission-track data from Eocene to Miocene sediments drilled in the Jianghan Basin suggest that material was supplied by the Dabie, Qinling and Jiangnan Orogens during Eocene to early Oligocene times. At late Oligocene, the source of sediments switched to the Huangling Massif, implying incision of the Three Gorges. We therefore propose that the modern Yangtze River system formed at the late Oligocene