| A | B |
|---|
| weathering | breaking down of rocks and other materials at the Earth's surface |
| mechanical weathering | weathering that does not involve change in the chemical makeup of rocks |
| exfoliation | breaking off of curved sheets or slabs parallel to a rock's surface due to weathering |
| frost action | breaking apart of a rock caused by water freezing and expanding within cracks |
| root-pry | breaking apart of rocks caused by the growth of plant roots |
| landslide | large downhill movement of loose rocks and soil caused by the pull of gravity |
| abrasion | wearing away of a substance by solid particles carried by wind, water, or other forces |
| chemical weathering | weathering that involves changes in the chemical makeup of rocks |
| oxidation | process in which oxygen chemically combines with another substance |
| carbonation | process in which carbonic acid reacts chemically with other substances |
| stable rock | rock composed of minerals that resist chemical weathering |
| residual soil | soil that remains on top of the rock from which it was formed |
| transported soil | soil that is moved away from its place of origin |
| bedrock | layer of rock beneath the soil |
| humus | part of the soil formed by decaying organic material |
| pore space | space between particles of soil |
| horizon | soil layer |
| soil profile | cross section of soil horizons |
| topsoil | soil in the A horizon, or uppermost layer of mature soil |
| leaching | process in which water washes minerals from the topsoil to the subsoil |
| subsoil | soil in the B horizon, or middle layer of soil |
| erosion | process by which the products of weathering are moved from one place to another |
| deposition | process by which sediments are laid down in new locations |
| mass wasting | downhill movement of sediments due to gravity |
| sand dune | mound of sand deposited by the wind |
| loess | accumulations of fine particles of sand and silt deposited by the wind |
| load | amount of sediment carried by a stream |
| drainage system | network of streams and other bodies of running water that ultimately drain into an area's main river |
| tributary | large stream or small river that flows into an area's main river |
| drainage basin | area drained by a major river |
| immature river | river in an early stage of development |
| mature river | river that has been developing for many thousands of years |
| meander | loop in a river |
| oxbow lake | U-shaped lake formed when erosion and deposition cut off a meander of a river |
| alluvial fan | fan-shaped deposit of sediments formed at the point where a river leaves the mountains and runs out onto a plain |
| delta | triangular formation of sediments deposited at the mouth of a large river that flows into a lake or ocean |
| flood plain | flat area found on both sides of a river or stream that is formed by sediments deposited during floods |
| levee | in nature, a ridgelike deposit along the sides of a river |
| glacier | large mass of moving ice and snow |
| till | rocks and debris deposited directly by a glacier |
| moraine | ridge of till left behind by a retreating glacier |
| drumlin | oval-shaped mound of glacial till |
| meltwater | water from melting ice or snow |
| outwash plain | flat, fan-shaped area in front of terminal moraines formed by sediments deposited by rivers of glacial meltwater |
| kettle lake | round, deep lake formed by a huge block of ice left behind by a glacier |
| sea cliff | steep face of rock produced by wave action |
| terrace | flat platform of rocks, sand, and silt at the base of a sea cliff |
| sea stack | column of resistant rock left behind after a sea cliff has eroded |
| sea cave | hollowed out portion of a sea cliff |
| longshore current | movement of water parallel to a shoreline |
| sand bar | long, underwater ridge of sand |
| spit | sand bar connected to the shoreline |
