Drainage divide migration between the Yellow and Yangtze Rivers at Eastern Qinling Mountains (central China): Insights from U-Pb ages of detrital rutile

Abstract

Drainage divide migration, influenced by tectonic processes and climate change, significantly shapes geomorphological dynamics and sediment dispersal patterns. However, observing this phenomenon directly is challenging due to its prolonged and dynamic nature. While some researchers have employed simulations to investigate divide migration, these studies often lack the necessary empirical geological validation. The Qinling Mountains in central China, characterized by tectonic uplift and the subsidence of the Weihe Basin, serve as an exceptional natural laboratory for examining the intricate dynamics of the drainage divide between the Yellow and Yangtze Rivers. This study examines the migration history of the Qinling divide since the Cenozoic by analyzing detrital rutile UPb geochronology from Cenozoic strata within the Weihe Basin. Our results show that rutile UPb age peaks in the sediments deposited during the Eocene to Early Miocene are principally distributed at 110–300 Ma, 350–680 Ma, 800–840 Ma, and greater than 1000 Ma. From the Late Miocene to the Pliocene, the UPb age of detrital rutile is mainly distributed at 110–300 Ma and 350–680 Ma. The source signal change revealed by the Weihe Basin deposit sequence in the Late Miocene due to the gradual northward migration of the drainage divide. By examining the chronological evolution of detrital rutile UPb ages within the basin, we shed light on the trajectory of the Qinling divide's migration, offering new insights into the landscape evolution under the influence of tectonics and climate factors since the Cenozoic.