| A | B |
|---|
| weathering | the disintegration and decomposition of rock at or near Earth's surface |
| erosion | the transport of weathered rocks by a mobile agent |
| mechanical weathering | the physical breaking up of rocks into smaller pieces that each retain their original characteristics |
| chemical weathering | the actual altering of a rock's chemistry by a chemical reaction |
| frost wedging | physical weathering caused by the expansion of water as it freezes within a rock body |
| talus slopes | large piles of rock rubble at the base of rock outcrops |
| sheeting | large slabs of igneous rock break loose in layers |
| joint | fractures in rocks caused by frost wedging |
| differential weathering | the fact that all rocks do not weather at the same rate |
| soil | an important natural resource that is the number one product of weathering |
| mass wasting | downslope movements of soil and unconsolidated materials (rock fragments) |
| landslides | common term for mass wasting |
| viscuous | thick, slowly flowing fluid |
| avalanche | large, rapid moving mass wasting event |
| gradient of a stream | slope of a stream's channel; vertical drop versus distance of flow |
| discharge | volume of water flowing past a certain point in a certain timeframe |
| mouth of a stream | where it empties into a larger river or sea |
| base level | lowest point to which a stream can erode its channel (usually sea level) |
| downcutting | when a stream physically erodes the Earth's surface under it, lowering it's base level |
| competence | maximum size of particles a stream is capable of carrying based on its velocity (energy) |
| capacity | maximum load (amount of sediment) a stream can carry |
| floodplain | flat valley floor caused by the side to side erosion of a stream close to its base level |
| meanders | wide, sweeping bends in an older stream |
| oxbow lake | an abandoned bend in a stream due to an erosion resistant portion of the floodplain |
| valley glacier | small glaciers in lofty mountain areas that follow old stream channels; also called alpine glaciers |
| ice sheets | large-scale masses of ice flowing out in all directions |
| ice cap | small scale ice sheets covering plateaus |
| piedmont glaciers | glaciers occupying the broad lowlands at the base of steep mountains; formed as valley glacier emerges from mountain valley |
| calving | when large pieces of ice break off the front of a glacier; form icebergs at sea |
| plucking | when a glacier loosens and lifts blocks of rock as it moves over a fractured surface |
| abrasion | when an advancing glacier grinds the surface below it and the rocks within it |
| rock flour | pulverized rock caused by abrasion; makes meltwater milky looking |
| glacial striations | large scratches and grooves in rock that show the direction of glacial movement |
| till | unsorted, mixed-sized sediments deposited directly by the glacier |
| moraines | layers, or ridges, of till |
| drumlins | streamlined, asymmetrical hills of till left in clusters as a glacier advances again over old drift |
| kettles | small depressions left by retreating glaciers |
| eskers | small ridges of sand and gravel formed by streams flowing in tunnels beneath the glacier itself |
| alluvial fan | a cone of debris formed by runoff in a desert and found at the base of steep mountain canyons |
| Dust Bowl of the 1930's | severe dust storms & wind erosion caused by overplowing of farmland, followed by a period of severe drought |
| deflation | lifting and removal of loose material in a desert; occurs simultaneously across entire surface of the desert |
| saltation | rolling and skipping of larger grains of sand along the surface of the desert by the force of winds |
| blowout | shall depressions caused by saltation |
| desert pavement | stony surace of coarse pebbles and cobbles formed as the final result of longterm deflation |
| loess | a blanket of fine, windblown silt over a broad area |
| dune | a large mound of sand that builds up around a clump of vegetation or rock that created a wind shadow |
