加州理工学院Michael P. Lamb团队揭示了落石坑壁退化与基岩滑槽形成源于干岩崩侵蚀。该研究于2025年3月12日发表在《地质学》杂志上。

撞击坑是太阳系岩石体的一个关键过程。撞击坑壁随后的退化可以记录古代的环境条件，如火星上的地表水。区分与液体相关的侵蚀地貌和与干燥过程相关的侵蚀地形仍然颇具挑战性。

研究组开发了一个在落石退化的干端构件情况下的地形发育模型。与风化层蠕变导致的火山口退化的典型模型不同，风化层蠕变使山坡变得平滑和松弛，结果表明，落石会产生河道化的地貌。局部落石使斜坡过度倾斜，导致落石产生增加，然后流入地形低点，通过类似于河流切口的地形反馈导致泄槽发育。虽然落石在景观演化模型中通常被忽视，但落石可以塑造火山口壁和陡峭的岩石斜坡，通过干燥过程形成河道化地貌，而仅靠风化层蠕变是不可能的。

附：英文原文

Title: Crater-wall degradation and bedrock-chute formation from dry rockfall erosion

Author: Benjamin T. Cardenas, Alexander R. Beer, Patrick J. Donohoe, Oak Kanine, James L. Dickson, Michael P. Lamb

Issue&Volume: 2025-03-12

Abstract: Impact cratering is a key process on rocky bodies in the solar system. The subsequent degradation of impact-crater walls can record ancient environmental conditions, such as surface water on Mars. Distinguishing erosional landforms associated with liquids from those associated with dry processes remains challenging. Here, we developed a model for landform development under a dry end-member case of degradation by rockfall. Unlike canonical models of crater degradation by regolith creep that smooth and relax hillslopes, results show that rockfalls produce channelized landforms. Rockfall locally oversteepens slopes, leading to increased rockfall generation, which is then funneled into topographic lows, causing chute development through topographic feedback similar to river incision. While typically neglected in landscape evolution models, rockfalls can shape crater walls and steep rocky slopes, creating channelized landforms by dry processes that are not possible with regolith creep alone.

DOI: 10.1130/G53096.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G53096.1/652832/Crater-wall-degradation-and-bedrock-chuteredirectedFrom=fulltext