Exogenous processes involve the breakdown and movement of earth's surface materials by external forces like weathering, erosion, and mass wasting. Weathering breaks down rocks through physical and chemical processes. Erosion wears away earth's surface by wind, water, or ice. Mass wasting involves large masses of materials moving down slopes due to gravity, such as debris flows, mudflows, and slumps. Sedimentation is the accumulation of eroded materials. Endogenous processes occur inside Earth and involve magmatism, volcanism, and metamorphism which change the composition of rocks.