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• Exogenic processes


  Geological phenomena and processes originating externally to the Earth's surface, shaped by solar energy and other external influences
• Weathering


  1. Mechanical

  2. Chemical

  3. Biological
• Mechanical weathering


  The physical breakdown of rock into unconnected grains and/or chunks without any chemical alteration
• Mechanical weathering processes


  • Exfoliation
  • Thermal expansion
  • Wedging (frost wedging, root wedging, salt wedging)
• Chemical weathering


  The breakdown of a rock due to the chemical changes it is experiencing, either on its surface or near-surface
• Chemical weathering processes


  • Dissolution
  • Hydrolysis
  • Oxidation
  • Hydration
• Erosion


  1. Wind erosion

  2. Glacial erosion

  3. Water/tidal erosion

  4. Mass wasting
• Wind erosion


  Sediments and loose soil carried by the wind to new locations, resulting in soil loss, soil dryness, soil structure deterioration, soil nutrient and productivity losses, and air pollution
• Glacial erosion


  Erosion caused by glacier movement, where rocks and ice being carried by glaciers weather against other stones on the Earth's surface
• Water/tidal erosion


  Erosion through water interaction on the affected rock, moving the sediments through traction, saltation, suspension, and solution
• Mass wasting


  The downslope movement of rocks, soil, and ice due to the pull of gravity, caused by factors like relief, slope stability, and fragmentation and weathering
• Types of mass wasting

  • Fall
  • Topple
  • Slide (rotational, translational)
  • Spread
  • Flow
• Weathering is responsible for creating soil on Earth
• Rotational slide


  • Masses move outward and downwards on one or more concave-upward failure surfaces, giving it a backward tilt to the slipping mass, sinking at the rear, and pushing at the toe
• Translational slide


  • Masses move along a planar failure surface that may run at least parallel to the slope
• Spread


  The lateral extension and fracturing of a coherent mass due to the plastic flow of its underlying material, occurring mostly as silt layers in the affected areas
• Flow


  Movement where materials become saturated and move downslope as a viscous (thick) fluid. The movement can range from slow to rapid, and the material's viscosity can range from being dry to extremely saturated, which usually follows an initial sliding movement. Basal or marginal shear surfaces can bound it, but flowing is the dominant movement of the displaced materials
• Complex


  The combination of any of the five defined movements. It can be determined by a primary type of movement followed by other types
• Types of mass wasting movements

  • Rotational slide
  • Translational slide
  • Spread
  • Flow
  • Complex
• All these motion types can be visualized in Page 1 of 07 Handout 3
• Classes of movement in terms of movement speed

  • Extremely slow
  • Prolonged
  • Moderate
  • Very rapid
  • Rapid
  • Extremely rapid
• A rockslide-debris type of avalanche involves extremely rapid movement of materials
• A creep is another material movement that can be classified as extremely slow to prolonged motion
• Slides and flows can have moderate to very rapid movement rates, depending on the amount of water present in the deforming mass
• Falls can have rapid to extremely rapid movement
• Deposition


  The process where sediments settle out of the transporting medium, usually associated with water
• Glaciers deposit their transported debris and sediments directly on the ground where the ice has traveled
• When the velocity of the wind goes down, the transported sediments and dust settles on the place where they are carried. The same goes for water
• Clasts


  Large sediments
• Matrix


  Surrounding fine-grained sediments
• Deposition process


  1. Sediments get pressed over by new bed buildup over the years (compaction)

  2. Dissolved chemicals in the water form new minerals (cement) when the pores in between sediments are filled with it, leaving the chemicals to bind with the sediments in a process known as cementation

  3. Some minerals get recrystallized (recrystallization)
• Diagenesis


  The combined processes of compaction, cementation, and recrystallization which create sedimentary rocks while these compacted sediments also undergo lithification
• Sedimentary environment


  The new area where the sediments are deposited
• Sedimentary environments


  • Glacial
  • Mountainous
  • Desert
  • Lacustrine
  • Fluvial
  • Delta
  • Beach
  • Shallow marine
  • Shallow water (carbonate)
  • Deep
• Glacial environment


  Areas where ice sheets and glaciers are located, usually in high-altitude mountains and polar regions. At the end of a glacier, piles of sediments ranging from fine clay to boulders (called glacial tills) can be found
• Mountainous environment


  Areas with high altitudes (but not covered in ice) and abundant in sediment materials
• Mountain stream


  • Areas where conglomerate rocks are commonly found. This is due to the tributaries' capability to carry sediments of varying sizes during flooding periods, creating thick beds of gravel and boulders
• Mountain front


  • Areas located at the mountain's base, where the water's velocity slows down to a halt. This creates a landform known as an alluvial fan, which is primarily made of sand and boulders
• Desert environment


  Areas with very dry air, little precipitation, hostile surroundings, and extremes in temperatures
• Cold Desert


  Deserts with little sunlight, cold temperatures, cold dry air, and extreme frost. Found commonly in polar regions, this environment functions almost similar to a glacial environment