Exogenic Processes

• In the previous lesson, you learned that our planet Earth is composed of rocks and minerals as part of the geosphere. Remember that geosphere is the solid portion of Earth that includes the lithosphere. The lithosphere is the outermost layer of the Earth which is composed of the crust and the upper mantle. In this lesson, you will learn about exogenic processes that play important roles in the formation variety of landscapes on this planet.
• Weathering, erosion or transportation, and deposition are exogenic processes that bring about changes in the configuration of Earth's surface.
• Exogenic processes take place at or near the earth's surface that makes the surface wear away. Exogenic processes are very destructive. They are responsible for degradation and sculpting the earth's surface.
• Weathering


  The process that breaks down rock into smaller pieces
• Physical weathering


  • Rock is physically broken into smaller pieces. Some factors that affect physical weathering are ice wedging, release of pressure, growth of plants, animals, and abrasion.
• Chemical weathering


  • The process of breaking down rock through chemical changes. Some factors that affect chemical weathering are water, oxygen, carbon dioxide, living organisms, and acid rain.
• Erosion


  Rock particles are carried away by wind, ice, and gravity. Weathering causes the rocks to break down. Erosion (water) or transportation moves the sediments downhill to other places.
• Sedimentation/ Deposition


  A natural process in which a material is carried to the bottom of bodies of water and forms to solid.
• Mass wasting


  The downward movement of a rock, soil and regolith due to the action of gravity. It is triggered by the following factors: over-steepened slope, water, earthquake, and vegetation removal.
• Classifications of mass wasting

  • Slump
  • Solifluction
  • Earthflow
  • Mudflow
  • Debris slide
  • Debris flow
  • Rock fall
  • Soil creep
• Generally, the disintegration and decomposition processes act together, but one may be dominant over the other depending on the climate. In addition, the weathered material lies on top of the layer of rock that is not weathered.
• 1. Name five examples of agents of erosion and give a brief description for each agent.

  • Wind
  • Water
  • Ice
  • Gravity
  • Waves
• Humans


  • Oxidation
  • Frost weathering
• Physical weathering


  Weathering process that breaks down rocks without changing their chemical composition
• Chemical weathering


  Weathering process that changes the chemical composition of rocks
• Weathering


  The breakdown of rocks and minerals on the surface of the Earth
• Erosion


  The transport of weathered material by agents such as water, wind, ice, or gravity
• Humans play a very important role in the weathering and erosion of rocks
• List down two sources and effects of weathering or erosion concerns.