| A | B |
|---|
| Differential weathering | the difference in degree of discoloration, disintegration, etc., of rocks of different kinds exposed to the same environment |
| Surface area | the extent of a 2-dimensional surface enclosed within a boundary |
| Bedrock | unbroken solid rock, overlaid in most places by soil or rock fragments |
| Sheet erosion | erosion by sheets of running water, rather than by streams |
| Gullying | to form (channels) by the action of water |
| Terracing | a raised level with a vertical or sloping front or sides faced with masonry, turf, or the like, esp. one of a series of levels rising one above another |
| Solifluction | the slow, downhill movement of soil or other material in areas typically underlain by frozen ground |
| Creep | the slow deformation of solid rock resulting from constant stress applied over long periods |
| Talus | a sloping mass of rocky fragments at the base of a cliff |
| Plateau | a land area having a relatively level surface considerably raised above adjoining land on at least one side, and often cut by deep canyons |
| Transported soil | soil taken or carried from one place to another |
| Residual soil | the soil that is remaining after the soluble elements have been dissolved |
| Humus | the dark organic material in soils, produced by the decomposition of vegetable or animal matter and essential to the fertility of the earth |
| Horizon | any of the series of distinctive layers found in a vertical cross section of any well-developed soil |
