Here's why:

* Talus slopes are accumulations of broken rock fragments (talus) at the base of a cliff or steep slope.

* Rockfall is the rapid, free-fall of rock fragments from a cliff face. As the rocks fall, they break into smaller pieces, creating the talus that forms the slope.

While other types of mass wasting like rock slides and debris flows can contribute to talus accumulation, rockfall is the primary process responsible for the formation of talus slopes.