Inversion of Dadu River Bedrock Channels for the Late Cenozoic Uplift History of the Eastern Tibetan Plateau

摘要

The Dadu River in the eastern Tibetan Plateau has the potential to record transient variations of tectonic uplift since the Late Cenozoic. In this study, we extracted bedrock channels of the Dadu River drainage basin from the 30 m ASTER digital elevation model. The longitudinal river profiles were then analyzed, and three generations of knickpoints were recognized via the slope area method. By solving the analytical solution of the linear transient stream power incision model, we determined a Late Cenozoic history of regional tectonic uplift. The results reveal slow pre-middle Miocene uplift rates (<0.1 mm/a) and then increased gradually to 0.33 +/- 0.03 mm/a since 12-15 Ma until present. This increase of uplift rate from bedrock channel inversion is consistent with the regional findings of low-temperature themochronology, emphasizing the potential and significance to utilize channel profiles to infer the tectonic uplift history.