A settlement or slide is a form of gravitational instability") that is characterized by the movement over a relatively short distance along a slope of a coherent mass of poorly consolidated materials or layers of rock. pending.

Translational settlements occur when a land mass moves along a flat surface.[2] Between the flat surfaces where these faults occur are meeting planes or deposits, especially where a permeable layer is located on an impermeable surface. Block settlements are a type of translational settlement in which one or more pieces of rock move downslope as a relatively coherent mass.

A rotational slide occurs when a block of sediment or rock slides along a concave upward sliding surface with rotation about an axis parallel to the slope.[3] Rotational motion causes the original surface of the block to lose inclination and the top of the block to rotate backward. This gives rise to an internal deformation of the moving mass consisting mainly of overturned folds called sheath folds.