Four maps of the Red River region in different periods of geologic history showing composition of sediment samples
Composition of modern and ancient sediment samples in terms of interpreted source terrains, based on a quantitative comparison of zircon ages in sediments and bedrock. The presence in Red-River sediments deposited 35 million years ago of significant quantities of material sourced from terrains now drained by the Yangtze River (and disappearance of this signal in younger sediments) shows that the Yangtze flowed into the Red River at that time, before being captured. The signal returns in the present Red River sediments due to recycling of earlier basin deposits. Credit: Clift et al. [2020], Figure 14
Source: Geochemistry, Geophysics, Geosystems

River patterns in Indochina and the southeastern Tibetan Plateau have attracted significant attention from geoscientists for several decades. This is because of both the starkly anomalous courses of these rivers (with three of Asia’s largest rivers, the Yangtze, Mekong and Salween, flowing parallel and only a few tens of kilometers apart for hundreds of kilometers in southeast Tibet) and the obvious implications for the tectonic and topographic history of the region. Controversial interpretations of how this drainage pattern has come about have been proposed in the last two decades.

Clift et al. [2020] use a large database of zircon U-Pb ages from modern and ancient sediments in southern China and northern Vietnam to argue that a large change in drainage occurred between the Oligocene and the Miocene, specifically that in the Oligocene the Yangtze River flowed into the Red River, feeding sediments to Vietnam and the Gulf of Hanoi, before being captured and redirected to its present route at the “big bend”. The work also shows how recently developed quantitative statistical tests can be used to compare zircon U-Pb age patterns between samples, rather than relying on solely visual or qualitative comparison.

Citation: Clift, P. D., Carter, A., Wysocka, A., Van Hoang, L., Zheng, H., & Neubeck, N. [2020]. A Late Eocene‐Oligocene through‐flowing river between the Upper Yangtze and South China Sea. Geochemistry, Geophysics, Geosystems, 21, e2020GC009046.

—Peter van der Beek, Editor, Geochemistry, Geophysics, Geosystems

Text © 2020. The authors. CC BY-NC-ND 3.0
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