Which feature is associated with stair-step canyons?

Stair-step canyons are characterized by their distinctive topography, which includes a combination of vertical cliffs and sloping walls. This formation occurs due to the varying resistance of rock layers exposed in the canyon walls; harder, more resistant layers create vertical cliffs, while softer layers erode more easily, resulting in the sloping walls. This alternating resistance leads to the step-like sections that define the canyon’s structure. As water flows through the canyon, it has a significant effect on the erosion of these layers, further promoting the unique stair-step formation.

Other choices do not accurately describe the specific features of stair-step canyons. For instance, random sediment distribution refers to an unrelated geological aspect that doesn't capture the systematic structure of the canyon. Volcanic activity typically leads to different geomorphological features, such as calderas or lava tubes, rather than stair-step formations. Likewise, while alluvial fans are associated with sediment deposition rather than the erosion patterns typical of stair-step canyons. Thus, the presence of vertical cliffs and sloping walls serves as the defining characteristic of stair-step canyons.