| Term | Definition |
|---|
| weathering | the breaking down of rock into smaller and smaller particles ( the rock on earth surface are undergoing this at all times, either mechanical or chemical) |
| mechanical weathering | this is when rocks are broken into smaller pieces by physical means (there are several agents of mechanical weathering and they are: ice, gravity, wind, plants, water, animals) |
| abrasion | a major force of mechanical weathering |
| ice | a unique material becuase it expands when it is frozen. causes a process called " forst-wedging" when frozen ice expands the liquid volume by 9% |
| wind | breaks down rocks by carving them with fragments of other rocks, it can pick up sand grains and when thestse collide with rock surfaces they "sand-blast" them removing a little rock at a time (this is a form of abrasion) |
| water (mechanical weathering) | the most effective agent of weathering on earth - extremely effective at moving materials and especially other rocks- when rocks encounter other surfaces tehy grind and weather - the more the abrasion a particle undergoies the more roudn it will become |
| gravity | material that are slopes, for instance hillsides or mountains have a tendency to roll down hill - during this roll they collide with other objects and weather them by abrasion |
| talus (colluvium) | refers to loose material (sediment) that is pulled downhill by gravity and forms a pile of material |
| Alluvium | refers to loose material (sediment) that is moved by water but drepped on land in a fan shape - deltas may form if the material is dumped in a body of water and sorted in teh process |
| exfoliation (unloading ) | caused when pressure is released from the outside of a body of rock and the internal pressure forces outer layers of the rock to shed - the material will teh fall down hill due to gravity |
| plants | grows through a crack in a rock |
| animals | burrowing througth and walking across tehm- one of teh most unique types of weathering, occurs in areas with a rock type called limestone |
| chemical weathering | teh break down of rocks adn minerals into a new substance (water, acid precipitation, ground water, animal/plants, air) |
| water (chemical weathering) | the process of materials dessolving into and being altered by water is a form of weathing- natural salts weather easily in this manner |
| hydrolysis (ex. potassium feldspar) | any process where water breaks the bonds of a material but doesn't dissolve them |
| acid precipitation | caused devastating weathering in some areas of the world- in creased acidity of teh precicpitation- air pollution provieds the sulfur oxides, nirtogen oxides, and the carbon dioxides to the air which bond with water to fom acid |
| ground water | an effective chemical weathering agent and many materials in earths surface, dissolve easily in weak acid (limestone- when exposed will dissolve which causes more desolving [caves, sinkholes]) |
| plants/animals | unrination/ digestions and chelation; acidic waste are an agent of chemical weathering |
| air (oxygen) (oxidized materials gain mass) | contact with teh atmosphere causes some materials to change |
| factors of weatheing | temperature, surface area, water (acidity), strength, mineral compostion, wind speed and compostion |
| weathing and climates | fastest chemical weathign; hot and wet/ fastest physical weathign; cold and wet ( temps that continually go above and below the freezing/melting point will accelerate mechanical weathering |
| surfae area | the more exposed, the faster teh weathing process( smaller particles) |
| soil | the loose coveing of broken rock particles and decaying organic matter overlying the bedrock of earths surface; forms by the chemical and physical(mechanical) weathign of rocks and other soils over time, animals and other orgainsims that live withing and above the sol beocme part of the soil as their remains decay; descirbed based on its location |
| soil horizons | need bot be present in all soil profiles; made of different parts: horizons A,B,C are well devoloped, O horizon is the top layer where decay is most recently or currently occuring |
| soil types | polar- the coldest/ typically frozen; temperate- the most fertile; desert- the dryest; tropical- heavily saturated usually extreeme chemical weathing |
| depletion | occurs when too many nutrients are removed from soil |
| desertificaion | overgazing of soils and the materials that grow within tehm |
| erosion | the transportation of rock, soil, and mineral particles from one location to another, the main driving force behind all agents is gravity |
| 5 main agents of ersosion | gravity, running water, glaciers, wind, waves/oceans |
| runnign water | the primary agent of erosion, any forms a stream, watersheds, source mouth, rounded and smooth, load |
| watershed | area dreained by a stream and its tributaries |
| tributary | smaller part of a large stream/river |
| source | beginning of a stream, starts at a higher elevation |
| mouth | were a stream empties into a larger body of water, lower elevater |
| continental divide | a line that connects points seperating large water sheds, high elevation |
| base level | is defined as the lowest level to which a stream can erode its channel, ultamate base level for all streams is the ocean |
| streams | running water going down hill, factors that affect their journey: amount of material, gradient/slope, topography, winds, underlying amterial, climate, vegetation |
| stream discharge | volume of a water flowing in a stream |
| channel of the stream | stream velocity is usually greatest just below the surface and in the center of teh channel |
| youthful | relatively straight channels, steep walled v-shaped valleys |
| mature | moderate grade gentle to steep valley walls with a well-developed floodplain and some meandering |
| old age | broad, wide, flat valley with extensive floodplains, many meanders adn possibly oxbow lakes |
| solutin | particles are dissolved in the water, travel at the same rate tht the stream is traveling |
| suspension | colliods very small sized partices are suspended within the water, slightly lower rate |
| saltation | rolling and bouncing, travels a a lot slower rate with high friction |
| floodplains | flat areas adjacent to a river or stream thta may be covered by water in times of a flood |
| deltas | a depostit at the mouth of a stream where sedimetn is dropped as it encounter slower moving water |
| meanders | bend in a stream |
| levees | ridges of sand and silt a long river or stream that prevent overflow |
| oxbow lakes | since th material lining the banks does not remain uniform the entire lenght of a river system, another landform called the oxbow lake can form |
| dendritic | these appear to branch like trees, tributaires have the same general flow direction |
| radial | the spokes of a wheel, devolop on smooth cones or domes |
| rectangular | parallel streams that follow folds and faults |
| annular | concentric circles that are connected by short radial streams segments |
| depostion | the final step in the erosional depostional systerm, most occurs at a mouth of a river |
| factors that affect deposition | particle size adn particles shape adn particle density and velocity |
| cross bedding | when varying flow directions deposti sediment in different planes most common in deserts or beaches and deltea and streams |
| wind erosion | deflation- the lowering of the land surface by the removal of fine grained particlesby the wind, abrasion, and saltation, loess, pitted |
| glacier | sub-rounded and scratches, till, 2 types, alpine and caontinental, 2 methods, sliding and flow, zone of accumulation- the portion of a glacier where snow is accumulation, zone of ablation- the portion of a glacier where snow is being lost, equilibuim line- teh pint on th eglaicer where accumulation is equal to ablaiton, moving forward-growing, moving backward- shiinking |
| gravity | angular and shapr, talus |
| horns | sharp pyramid shped peaks |
| aretes | sawtooth jagged ridges |
| cirpues | steep walled bowls |
| fjords | u shaped valleys |
| rouche montonee | sheep shaped bedorck |
| striations | parallel schatches on bedrock showin flow direction |
| grooves | same and striation |
| kettles | holes that formed where large pieces of glacvial ice melted |
| eskers | meandering rigbees of seidment formed by sub glaical melting |
| outwash pains | broad flat area filled with glacial outwahs |
| drumlins | stream lined depoistits that indicat ice flwo direction |
| mroaines | terminal, laterial. ground, recessional |
| terminal | the furthest the ice advanded leaving sediment as a riged |
| laterial | ridges of amterial that form on the side of a flaicer |
| gound | that material that is deposited nebeath the glaicer |
| recessional | material that was deposied as a glacier suddleny retreated |
| mass wasting | dowinhill moveent of regotlith by gravity alone, only occurs on a slope |
| landslide | mudflows or earthflows |
| creep | very slow usually continuous movement of regolith down slope coused by the cohesivenesss of the slope material and excess moisutre |
| longshore dirft | movemnt of sand parallel to the shore |
Combine with other sets
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