Formation Mechanism for Upland Low-Relief Surface Landscapes in the Three Gorges Region, China

Abstract

Extensive areas with low-relief surfaces that are almost flat surfaces high in the mountain ranges constitute the dominant geomorphic feature of the Three Gorges area. However, their origin remains a matter of debate, and has been interpreted previously as the result of fluvial erosion after peneplain uplift. Here, a new formation mechanism for these low-relief surface landscapes has been proposed, based on the analyses of low-relief surface distribution, swath profiles, χ mapping, river capture landform characteristics, and a numerical analytical model. The results showed that the low-relief surfaces in the Three Gorges area could be divided into higher elevation and lower elevation surfaces, distributed mainly in the highlands between the Yangtze River and Qingjiang River. The analyses also showed that the rivers on both sides of the drainage divide have not yet reached equilibrium, with actively migrating drainage divides and river basins in the process of reorganizing. It was concluded that the low-relief surfaces in the Three Gorges area did not share a common uplift history, and neither were they peneplain relicts, but rather that the effect of “area-loss feedback” caused by river capture has promoted the formation of upland low-relief surface landscapes. A future work aims to present the contribution of accurate dating of low-relief surface landscapes.

Late Cenozoic erosion pattern of the eastern margin of the Sichuan Basin: Implications for the drainage evolution of the Yangtze River

“…Elevations of the remaining erosion surfaces range mostly between ∼150 m and >2500 m, and generally increase from the northeast to the southwest. Frequency distribution of elevation of the mapped low-relief surfaces shows at least two peaks (Figure 4b), consistent with previous inference that the erosion surfaces formed at different ages (Liu et al, 2019;Lv et al, 2020). The most extensive surfaces occur in the high reaches of the Wu River in the south of the catchment, and also expand eastwards across the drainage divide into the Yuan River.…”

Active Deformation Pattern in the Western Flank of the Central Taurides, Southern Margin of the Central Anatolian Plateau: Inferences From Geomorphic Markers and Kinematic Indicators

“…Low relief perched upland surfaces are slightly undulated remnants of a pre‐existing landscape (Clark et al., 2006; Lv et al., 2020; Stearns, 1967; Whipple et al., 2017). The coexistence of these relic surfaces with the geomorphic units like steep gorges reflects a transient topography that is trying to adjust the changing surface elevation (Clark et al., 2006).…”