Weathering

• Earth is mainly composed of rocks that differ in terms of sizes, shapes and colors
• Rocks are broken down into smaller pieces by the effects of weather
• Weathering


  The breaking of rocks into fragments
• Weathering is an important process that helps shape the earth's surface
• The breaking of rocks results in the formation of soil and different landforms
• Weathering can either be mechanical or chemical
• Mechanical weathering


  The physical wearing away of rocks without any change in their chemical nature
• Mechanical weathering


  • Rocks break down into smaller pieces due to physical forces such as water and temperature without changing the mineral compositions
  • Rocks exposed to intense heat crack and crumble
  • Water accumulating in cracks of rocks expands as temperature changes, causing the cracks to become deeper and new cracks to form
• Chemical weathering


  Involves change in the composition of rocks that allows them to break down into pieces
• Chemical weathering


  • Rocks break down due to reaction with water, carbon dioxide, oxygen and organic acids, forming new substances from the minerals of rocks
• Agents of weathering


  • Water
  • Wind
  • Temperature
  • Plants
  • Animals
  • Humans
• Water as an agent of weathering

  • Strong waves seep into cracks of rocks
  • Water in cracks can expand when it freezes, triggering rocks to break
• Wind as an agent of weathering

  • Carries sand or small particles that scratch rocks
  • Can result in mechanical weathering and different rock formations
• Temperature as an agent of weathering

  • Rocks expand when exposed to high temperatures, and contract when exposed to low temperatures
  • Repeated expansion and contraction results in weathering
• Plants as agents of weathering

  • Can grow on rocks and cause them to break into pieces
  • Metabolic or life processes of plants can gradually break down rocks
• Animals as agents of weathering

  • Burrowing animals digging underground can cause rocks to break into pieces
• Humans as agents of weathering

  • Use bulldozers, jackhammers, and explosives to break down rocks for construction and mining purposes