All of these processes generally grade into one another, so classification of such processes is somewhat difficult. We will use the classification in your textbook, dividing mass-wasting processes into two broad categories. Slope Failures - a sudden failure of the slope resulting in transport of debris down hill by sliding, rolling, falling, or slumping. Sediment Flows - debris flows down hill mixed with water or air. The upper surface of each slump block remains relatively undisturbed, as do the individual blocks.
Slumps leave arcuate scars or depressions on the hill slope.
Slumps can be isolated or may occur in large complexes covering thousands of square meters. They often form as a result of human activities, and thus are common along roads where slopes have been oversteepened during construction. They are also common along river banks and sea coasts, where erosion has under-cut the slopes. Heavy rains and earthquakes can also trigger slumps. Falls - Rock falls occur when a piece of rock on a steep slope becomes dislodged and falls down the slope.