TY - JOUR
T1 - Late Cenozoic erosion pattern of the eastern margin of the Sichuan Basin
T2 - Implications for the drainage evolution of the Yangtze River
AU - Jiao, Ruohong
AU - Fox, Matthew
AU - Yang, Rong
N1 - Funding Information:
Topographic data used in this study is available from www.hydrosheds.org . TopoToolBox 2 ( Schwanghart and Scherler, 2014 ) was used for processing topographic data. Fig. 1 was produced using Generic Mapping Tools ( Wessel et al., 2013 ). A MATLAB implementation of the L-BFGS algorithm ( https://www.mathworks.com/matlabcentral/fileexchange/23245-fminlbfgs-fast-limited-memory-optimizer ) was used for solving the nonnegative least squares problem. Jiao was supported by the Natural Sciences and Engineering Research Council of Canada ( RGPIN-2019-04405 ). Fox was supported by the Natural Environment Research Council ( NE/N015479/1 ). Yang was supported by the National Natural Science Foundation of China ( 41961134031 ). Edward Keller, Martin Stokes, and an anonymous reviewer provided valuable comments and suggestions that helped improve the paper substantially.
Publisher Copyright:
© 2021
PY - 2022/2/1
Y1 - 2022/2/1
N2 - Evolution of the drainage network of the Yangtze River plays an important role in landscape evolution across East Asia during the Cenozoic. The mountains on the eastern margin of the Sichuan Basin form a drainage divide between the tributary rivers of the modern Upper and Middle Yangtze, and the erosion history of these mountains has major implications for the evolution of the Yangtze River. Linear inversion of long profiles of two Yangtze tributaries draining the area allows us to estimate their incision processes, and reveals contrasting erosion patterns between the west and east sides of the mountain belt. Along the Wu River, which drains into the Sichuan Basin, higher incision rates are focused on lower channels near the river's outlet on the Upper Yangtze. In contrast, within the catchment of the Yuan River, which drains into the Jianghan Basin of the Middle Yangtze, the inverted fluvial erosion rate is distributed relatively uniform in space. We calibrate the inferred incision history using previously published cosmogenic 10Be-derived basin-averaged erosion rates, and the results show that the contrasting erosion patterns between the two rivers emerged since the early Miocene (~21–16 Ma). At this time, the incision rates of the lower Wu River started to increase from ~0.04 km/Ma towards the Quaternary average at ~0.07 km/Ma, while the rates of the Yuan River remained low (<0.04 km/Ma). By comparing our results with erosion histories of the eastern Sichuan Basin and Three Gorges, we suggest that during the early Miocene, connection between the Sichuan and Jianghan Basins through the Three Gorges led to additional lowering of the local base level in the Sichuan Basin, which triggered an acceleration in incision rates of the Upper Yangtze tributaries draining into the basin.
AB - Evolution of the drainage network of the Yangtze River plays an important role in landscape evolution across East Asia during the Cenozoic. The mountains on the eastern margin of the Sichuan Basin form a drainage divide between the tributary rivers of the modern Upper and Middle Yangtze, and the erosion history of these mountains has major implications for the evolution of the Yangtze River. Linear inversion of long profiles of two Yangtze tributaries draining the area allows us to estimate their incision processes, and reveals contrasting erosion patterns between the west and east sides of the mountain belt. Along the Wu River, which drains into the Sichuan Basin, higher incision rates are focused on lower channels near the river's outlet on the Upper Yangtze. In contrast, within the catchment of the Yuan River, which drains into the Jianghan Basin of the Middle Yangtze, the inverted fluvial erosion rate is distributed relatively uniform in space. We calibrate the inferred incision history using previously published cosmogenic 10Be-derived basin-averaged erosion rates, and the results show that the contrasting erosion patterns between the two rivers emerged since the early Miocene (~21–16 Ma). At this time, the incision rates of the lower Wu River started to increase from ~0.04 km/Ma towards the Quaternary average at ~0.07 km/Ma, while the rates of the Yuan River remained low (<0.04 km/Ma). By comparing our results with erosion histories of the eastern Sichuan Basin and Three Gorges, we suggest that during the early Miocene, connection between the Sichuan and Jianghan Basins through the Three Gorges led to additional lowering of the local base level in the Sichuan Basin, which triggered an acceleration in incision rates of the Upper Yangtze tributaries draining into the basin.
KW - Numerical modeling
KW - River incision
KW - Sichuan Basin
KW - Yangtze River
UR - http://www.scopus.com/inward/record.url?scp=85118883554&partnerID=8YFLogxK
U2 - 10.1016/j.geomorph.2021.108025
DO - 10.1016/j.geomorph.2021.108025
M3 - Article
AN - SCOPUS:85118883554
SN - 0169-555X
VL - 398
JO - Geomorphology
JF - Geomorphology
M1 - 108025
ER -