What process causes the gradual movement of soil and rock material down a slope?

• A. Mass wasting
• B. Erosion
• C. Weathering
• D. Denudation

Answer: (A)

Mass wasting refers specifically to the process that causes the downward movement of soil, rock, and other materials under the influence of gravity. This phenomenon occurs when the stability of these materials is compromised, leading to their movement down a slope. Mass wasting can happen rapidly, as in landslides, or it may occur slowly over time, such as with soil creep.

The other processes listed have different definitions and implications. Erosion involves the removal and transportation of surface materials by wind, water, or ice but does not specifically denote the gravitational movement of materials down a slope. Weathering is the breaking down of rocks and minerals through physical, chemical, or biological processes without the movement of the material. Denudation is a broader term that encompasses processes that lower the Earth's surface, including both erosion and weathering, but it does not specifically focus on the gravity-driven movement of materials like mass wasting does. Therefore, mass wasting is the most accurate term for the process described in the question.