| A | B |
|---|
| chemical weathering | the processes by which the internal structure of a mineral is altered by the removal and/or addition of elements |
| creep | the slow downhill movement of soil and regolith |
| earthflow | slow-moving downslope movement of water-saturated, clay-rich sediment, most characteristic of humid regions |
| exfoliation | type of weathering caused by reducing pressure on a rock surface, allowing slabs of outer rock to break off in layers |
| frost wedging | the mechanical breakup of rock caused by the expansion of freezing water in cracks and crevices |
| laterite | a red, highly leached soil type found in the tropics that is rich in oxides of iron and aluminum |
| mass movement | the downslope movement of rock, regolith, and soil under the direct influence of gravity |
| mechanical weathering | the physical disintegration of rock, resulting in smaller fragments |
| mudflow | quickly moving downhill flow of soil and rock fragments containing a large amount of water |
| pedalfer | soil of humid regions characterized by the accumulation of iron oxides and aluminum-rich clays in the B horizon |
| pedocal | soil associated with drier regions and characterized by an accumulation of calcium carbonate in the upper horizons |
| regolith | the layer of rock and mineral fragments that nearly everywhere covers Earth’s surface |
| rockfall | occurs when rocks or rock fragments fall freely through the air; common on steep slopes |
| rockslide | occurs when a mass of rock slides rapidly downslope along planes of weakness |
| slump | the downward slipping of a mass of rock or unconsolidated material moving as a unit along a curved surface |
| soil | a combination of mineral and organic matter, water, and air; that portion of the regolith that supports plant growth |
| soil horizon | a layer of soil that has identifiable characteristics produced by chemical weathering and other soil-forming processes |
| soil profile | a vertical section through a soil showing its succession of horizons and the underlying parent material |
| talus | an accumulation of rock debris at the base of a cliff |
