WEATHERING, EROSION & SOIL FORMATION. WEATHERING, EROSION, TRANSPORTATION Weathering- Physical disintegration and chemical decomposition of rocks Erosion-

  • View
    225

  • Download
    0

Embed Size (px)

Text of WEATHERING, EROSION & SOIL FORMATION. WEATHERING, EROSION, TRANSPORTATION Weathering- Physical...

  • WEATHERING, EROSION & SOIL FORMATION

  • WEATHERING, EROSION, TRANSPORTATIONWeathering- Physical disintegration and chemical decomposition of rocksErosion- Physical removalTransportation- Movement of eroded particlesChemical vs. Physical WeatheringEffects of weatheringSurface alteration of outcropsSpheroidal weatheringDifferential weathering

  • Physical Weathering

  • Transport

  • Abrasion

  • WEATHERING, EROSION, TRANSPORTATIONWeathering- Physical disintegration and chemical decomposition of rocksErosion- Physical removalTransportation- Movement of eroded particlesChemical vs. Physical WeatheringEffects of weatheringSurface alteration of outcropsSpheroidal weatheringDifferential weathering

  • Differential Weathering

  • MECHANICAL WEATHERINGDisintegration of rocksFrost ActionFrost wedging - rock pried apart along jointswater expands upon freezing (ice wedge)Frost heaving

  • Frost Action

  • MECHANICAL WEATHERINGPressure Releasesheet jointexfoliation exfoliation domesOtherPlant growth; Burrowing animalsPressure of salt crystalsExtreme temperature changesMechanical weathering increases surface area facilitating chemical weathering

  • Exfoliation

  • Organic Action

  • Mechanical WeatheringGrowth of salt crystal in arid/semi-arid regions can split rocksHeat and cold extremes can also cause rock breakage

  • CHEMICAL WEATHERINGDecomposition of rock to form new substancesEquilibriumRole of OxygenFe in ferromagnesian minerals becomes oxidized HematiteLimonite

  • Chemical WeatheringRole of AcidHydrogen ions in waterpH=-Log[H+] Acid/BaseCarbonic Acid H2CO3 CO2 + H2O -> H2CO3 H2CO3 -> H+ + HCO3- (in water) Solution weathering- Karstic FeaturesCalcite (in limestone) dissolves in acidic waterfluted (channeled) rock surfacecaves

  • Chemical WeatheringRole of AcidHydrogen ions in waterpH=-Log[H+] Acid/BaseCarbonic Acid H2CO3 CO2 + H2O -> H2CO3 H2CO3 -> H+ + HCO3- (in water) Solution weathering- Karstic FeaturesCalcite (in limestone) dissolves in acidic waterfluted (channeled) rock surfacecaves

  • KARST

  • Chemical WeatheringChemical weathering of feldsparH+ + feldspar -> clay mineralChemical weathering of other mineralsWeathering and climateWeathering Products

  • Chemical WeatheringChemical weathering of feldsparH+ + feldspar -> clay mineralChemical weathering of other mineralsWeathering and climateWeathering Products