Which term describes the external process of transferring rock material downslope?

The term that describes the external process of transferring rock material downslope is mass-wasting. This process involves the movement of soil, rock, and debris down a slope due to the influence of gravity. It can occur in various forms, such as landslides, rockfalls, and mudslides, and is characterized by the movement of material rather than the breaking down or wearing away of material, which is what occurs during weathering.

Mass-wasting is distinct from erosion, which involves not only the movement of material but also the wearing away of rocks and soil through agents such as water, wind, or ice. While erosion leads to the transport of these materials over greater distances, mass-wasting specifically refers to the gravity-driven movement down a slope.

In contrast, deposition is the process where transported sediments are laid down or settled in a new location, often forming new landforms. It is the final stage in the cycle of erosion and transportation but does not describe the active downslope movement associated with mass-wasting. Weathering is also a separate process that involves the mechanical or chemical breakdown of rocks, making them more susceptible to further movement. Thus, mass-wasting is the most appropriate term for the process of transferring rock material downslope.