Explanation:

These movements are most prevalent in humid climatic regions and occur over gentle to steep slopes. Movement of water-saturated clayey or silty earth materials down lowangle terraces or hillsides is known as earth flow. Quite often, the materials slump making step-like terraces and leaving arcuate scarps at their heads and an accumulation bulge at the toe. When slopes are steeper, even the bedrock, especially of soft sedimentary rocks like shale or deeply weathered igneous rock, may slide downslope.