Unraveling the exhumation history of the source terrains of the western Jianghan Basin (Central China) through detrital zircon fission track dating

The Jianghan Basin, at the junction of the Jiangnan and Qinling-Dabie orogenic belts, has a complete Cretaceous to Paleogene stratigraphic record. However, the exhumation history of its source terrains is not well understood. We conducted fission track age analysis on zircon grains (n = 441) from the Cretaceous and Paleogene strata in the western Jianghan Basin. The RadialPlotter software is utilized to identify peak ages that indicate thermal events and the history of exhumation. The oldest peak at 810 Ma records the Neoproterozoic collisional orogeny between the Yangtze Craton and Cathaysian Block. Ages of 645-558 Ma reflect the convergence between the South China Block and Gondwana. Early Paleozoic ages document the collision leading to the exhumation of the western Jiangnan Orogenic Belt. Late Paleozoic to early Mesozoic peak ages correspond to the Indosinian orogeny. During the Mesozoic, the subduction of the Paleo-Pacific Plate resulted in further exhumation. The absence of Paleogene zircon fission track peak ages in the basin strata suggests limited exhumation during this period, likely due to tectonic quiescence and arid climatic conditions.