what two things are required for mass movement
rocks and mud
a slope and
freezing and sediments
repeated freezing and thawing
soil
you may have seen rock walls or high fences between a highway and a steep slope. the barriers are there to prevent loose rocks and soil from falling onto the the road. Mass movement is a from of erosion in which soil,rocks,or sediments move downslope due to gravity.
First, weathering breaks up large rocks high on the hill. Gravity causes loose rocks and soil to move down the hill. Deposition takes place when the sediments lose their energy of motion and stop. This usually occurs when the slope becomes flat or when there is a depression in the hill.
Some types of mass movement, such as a landslide, happen very quickly. A landslide occurs when heavy rains cause large rocks on a steep slope to break loose. The loose rocks tumble down the slope, striking other rocks and breaking them free. As long as the slope remains steep, the landslide continues to gather more material and gain speed. A over trees or houses, carry them away, or bury them.
Sediments are deposited when they reach the bottom of the slope. The loose mixture of rocks
heavy snows often accumulate on mountain slopes.