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

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.