1.   However, a shift in the type of sediment from weathered to unweathered material is noted at this level.

2.   The interface between weathered material and unweathered bedrock is known as the weathering front.

3.   High rates of weathering are not a prerequisite for the formation of deep weathering profiles if the rate of removal of weathered material is sufficiently slow.

4.   The situation on mountain slopes in the humid tropics is, however, quite different as here high erosion rates lead to the rapid removal of weathered material.