| A | B |
|---|
| Weathering | Break up of rock due to exposure to the atmosphere |
| Erosion | Removal and transport of earth materials by natural agents |
| Mechanical Weathering | Breaking of rock into smaller pieces of the same material |
| Chemical Weathering | Weathering where rock's minerlas are changed into a new substance |
| Ice Wedging (Frost Action) | Mechanical weathering process in which water freezing in cracks of rocks wedges rocks apart |
| Exfoliation | Peeling of surface layers from exposed bedrock |
| Hydrolysis | Any chemical reaction of water with other substances |
| Oxidation | The chemical reaction of oxygen with other substances |
| Carbonic Acid | A weak acid formed when carbon dioxide dissolves in water |
| Soil | Loose, weathered rock and organic material in which plants roots can grow |
| Parent Material | Rock material from which soil is formed |
| Residual Soil | Soil that has the local bedrock as its parent material |
| Transported Soils | Soil that formed from parent material left by winds, rivers, or glaciers or soil that itself was moved from its original location |
| Soil Profile | Cross section of soil layers above the parent material, usually consisting of the A-, B-, and C-horizons |
| Topsoil | The A-horizon of soil, contains organic material |
| Subsoil | The B-horizon of soil that contains clay and iron oxides washed from the topsoil |
| Mass Movement | The downslope movement of large masses of earth materials due to the pull of gravity |
| Creep | Slow, often invisible, movement of soil down a slope |
| Landslide | A sudden movement of a mass of bedrock or loose rock down the slope of a hill, a mountain, or cliff |
| Mudflow | The rapid downhill movement of a water-saturated mass of clay and silt |
| Abrasion | Wearing away of rock by grinding action |
| Suspension | The state in which rock materials carried by a river are sturred up and kept from sinking by the turbulence of stream flow |
| Solution | The state in which mineral matter dissolved from bedrock is carried in a river |
| Bed Load | Sand, pebbles, and boulders that are moved along the bed of a stream and that are too heavy to be carried in suspension |
| Discharge | The volume of water flowing past a given point in a stream at a given time |
| Gully | A miniature valley formed by erosion from heavy rains |
| Divide | The higher land separating two adjacent drainage basins |
| Drainage Basin (watershed) | Area of land surface drained by a river system |
| Potholes | Deep oval or circular hole cut into a stream bed by abrasion from swirling sand and pebbles |
| Flood Plain | Wide, level area that borders a stream and is covered by its water in the time of a flood |
| Meanders | One of a series of broad, looping bends in a stream |
| Oxbow Lake | Crescent shaped lake formed when a river meander cuts off from the river and the ends of the original bend have silted up |
| Delta | A fan-shaped deposit of sediment, formed at the mouth of a stream or river |
| Alluvial Fan | Sloping triangular deposits of sediment located where a mountain stream reaches level land |
