Upgrade of Java Quiz: Soils Soils are formed by the processes of weathering when the regolith, the accumulating surface layer of sediment also formed by weathering, is not disturbed by erosion. The regolith undergoes reorganization, by the processes of weathering, so that distinct horizontal layers (soils horizons) are formed. These layers stack vertically to form a soil profile. Tools Quiz created by: Russell J. Wernlund This activity was created by a Quia Web subscriber. To learn how to make your own, just like this, click here.