美国西弗吉尼亚大学Charles M. Shobe团队揭示了倾角控制着基岩河流的拔蚀敏感性和裂缝演化。相关论文发表在2025年7月1日出版的《地质学》杂志上。

基岩河流侵蚀推动了地球表面大部分地区的景观演变。拔蚀是河流基岩侵蚀的关键机制，但人们对拔蚀控制的理解有限。不连续方向（如倾角）可能会显著影响拔蚀动力学，但这尚未经过测试。研究组首次直接观察到倾角对拔蚀过程和裂点形态动力学的影响。 

通过水槽实验，研究组使用堆叠在三个方向（上游倾斜、水平和下游倾斜）的瓷砖对倾斜基岩的侵蚀进行了建模。结果发现水平层最易受侵蚀，其次是下游倾斜层，然后是上游倾斜层。倾角也影响裂点坡度、床面粗糙度、护面动力学和流动结构，这些因素相互作用，共同控制裂点形态演化。这些观测结果表明，倾角对以拔蚀为主的基岩裂隙点的演变有着深远的影响，并为人们理解地球表面许多不连续性景观中的景观演变提供了信息。

附：英文原文

Title: Dip angle controls on plucking susceptibility and knickpoint evolution in bedrock rivers

Author: Kristin D. Chilton, Michael Zedan, Kyle Strom, Charles M. Shobe

Issue&Volume: 2025-07-01

Abstract: Bedrock river erosion drives landscape evolution across much of Earth’s surface. Plucking is a key mechanism of fluvial bedrock erosion, yet our understanding of the controls on plucking is limited. Discontinuity orientation (e.g., dip angle) may significantly influence plucking dynamics, but this remains untested. We present the first direct observations of the impact of dip angle on plucking processes and knickpoint morphodynamics. Using flume experiments, we modeled erosion through dipping bedrock using stacked tiles held at three orientations: upstream-dipping, horizontal, and downstream-dipping. We find that horizontal beds are the most erodible, followed by downstream-dipping then upstream-dipping beds. Dip angle also influences knickpoint slope, bed roughness, armoring dynamics, and flow structure, which all interact to govern knickpoint morphological evolution. These observations demonstrate the profound effects of dip angle on the evolution of plucking-dominated bedrock knickpoints, and inform our understanding of landscape evolution within the many discontinuity-defined landscapes at Earth’s surface.

DOI: 10.1130/G53413.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G53413.1/659310/Dip-angle-controls-on-plucking-susceptibility-and