| A | B |
|---|
| abrasion | mechanical weathering in which rocks collide and scrape against each other, wearing away the exposed surface |
| butte | elevated, narrow, flat-topped area |
| carbonation | chemical weathering process in which minerals react with carbonic acid |
| chemical weathering | process in which rock is broken down as a result of chemical reactions |
| creep | slow downhill movement of weathered rock material |
| erosion | process by which the products of weathering are transported |
| exfoliation | process in which sheets of rock peel or flake as a result fo weathering |
| horizon | layer of a soil profile |
| humus | dark, organic material formed from the decayed remains of plants and animals |
| hydrolysis | chemical reaction between water and another substance |
| ice wedging | mechanical weathering caused by the freezing and thawing of water that seeps into cracks in rocks |
| landform | physical feature of the earth's surface |
| landslide | sudden movement of loose rock and soil down a slope |
| laterite | thick infertile soils produced in tropical climates |
| leaching | process in which water carries dissolved minerals to lower layers of rock |
| mass movement | movement of rock fragments down a slope |
| mechanical weathering | process that changes the physical form of rocks |
| mesa | elevated, flat-topped area smaller than a plateau |
| monadnock | knob of rock that protrudes above a peneplain |
| mudflow | rapidly moving large mass of mud |
| oxidation | a chemical combination of metallic elements with oxygen |
| peneplain | low, almost level surface of a mountain in its old stage |
| regolith | layer of weathered rock fragments convering much fo the earth's surface |
| rockfall | fall of rock from a steep cliff |
| sheet erosion | process in which parallel layers of topsoil are stripped away, exposing the surface of the underlying subsoil or partially weathered bedrock |
| slump | downhill movement of a large block of soil under the influence of gravity |
| soil profile | cross section of soil layers and bedrock |
| solifluction | slow downslope flow of wet, muddy top-soil over frozen or clay-rich subsoil |
| talus | pile of rock fragments that accumulates at the base of a slope |
| weathering | change in the physical form or chemical composition of rock materials exposed at the earth's surface |
