| A | B |
|---|
| weathering | the breaking down of rocks and other materials at the Earth's surface |
| mechanical weathering | weathering that does not involve changes in chemical makeup of rocks |
| exfoliation | the breaking off of curved sheets or slabs parallel to a rock's surface due to weathering |
| frost action | the breaking apart of a rock caused by the water freezing and expanding within cracks |
| root-pry | the breaking apart of rocks caused by the growth of plant roots |
| landslide | a large downhill movement of loose rocks and soil caused by the pull of gravity |
| abrasion | the wearing away of a substance by solid particles carried by wind, water, and other forces |
| chemical weathering | weathering that involves changes in the chemical makeup of rocks |
| oxidation | the process in which oxygen chemically combines with another substance |
| carbonation | the process in which carbonic acid reacts chemically with other substances |
| stable rock | a rock composed of minerals that resist chemical weathering |
| residual soil | soil that remains on top of rock from which it is formed |
| transported soil | soil that is moved awy from its place of origin |
| bedrock | the layer of rock beneath the soil |
| humus | the part of soil formed by decaying organic material |
| pore space | a space between soil and particles |
| horizon | soil layer |
| soil profile | a cross section of soil horizons |
| topsoil | the soil in A horizon, or uppermost layer of mature soil |
| leaching | the process in which water washes minerals from the topsoil to the subsoil |
| subsoil | the soil in the B horizon, or middle layer of soil |
