What geological feature is formed by the erosion of softer rocks leaving harder rocks behind?

The geological feature formed by the erosion of softer rocks while leaving harder rocks behind is a cliff or mesa. This process occurs due to differential erosion, where rocks of varying hardness erode at different rates. Softer rocks are removed by weathering and the action of water, wind, or ice, while the harder rocks resist erosion and remain exposed.

Cliffs often form along the edges of a plateau or in areas where resistant rock layers stand out against the surrounding terrain. Mesas, on the other hand, are more extensive flat-topped formations that also result from this process of erosion. The key to both features is the contrast between the erosion rates of the materials, leading to the prominent and often vertical profiles characteristic of cliffs and the flat surfaces of mesas. This principle of differential erosion is fundamental in understanding how various landforms develop over time.