earth

• Rock Types


  • Igneous
  • Sedimentary
  • Metamorphic
• Igneous Rocks


  • Formed from magma (melted underground rock) pushed up to the surface
  • Contain various minerals in randomly arranged interlocking crystals
  • Crystal size depends on cooling speed - large crystals mean slow cooling
• Types of Igneous Rocks

  • Extrusive
  • Intrusive
• Igneous Rocks


  • Basalt (extrusive)
  • Granite (intrusive)
• Sedimentary Rocks


  • Formed from layers of sediment (rock fragments or dead matter) laid down in lakes or seas over millions of years
  • Layers cemented together by other minerals
  • Can contain fossils
• Sedimentary Rocks


  • Limestone
  • Chalk
  • Sandstone
• Metamorphic Rocks


  • Result of heat and increased pressure acting on existing rocks over long periods
  • May have very fine crystals and some have layers
• Metamorphic Rocks


  • Marble
  • Slate
  • Schist
• The Rock Cycle


  1. Weathering

  2. Erosion

  3. Transportation

  4. Deposition

  5. Burial/Compression/Cementation

  6. Heat/Pressure

  7. Melting

  8. Cooling

  9. Exposure
• The rock cycle involves changing the three types of rock (igneous, sedimentary and metamorphic) from one to another
• The amount of rock on the surface is always about the same, even though it's weathered away
• Weathering Processes


  • Onion skin weathering
  • Freeze-thaw weathering
• Carbon is a very important element because it's part of all living things
• The Carbon Cycle


  1. Carbon dioxide in the air

  2. Respiration by plants

  3. Photosynthesis by plants

  4. Feeding

  5. Plant and animal remains

  6. Decomposers release carbon dioxide into the air

  7. Carbon compounds in fossil fuels
• The Earth's atmosphere is made up of 78% nitrogen, 21% oxygen, and 0.04% carbon dioxide
• The level of carbon dioxide in the Earth's atmosphere is rising due to human activities and natural causes
• Carbon dioxide is a greenhouse gas


  It traps energy from the Sun in the Earth's atmosphere, helping to keep the Earth warm
• The long term trend shows that the temperature of Earth is increasing, most likely due to the rise in carbon dioxide levels
• Global warming


  The increase in the Earth's temperature due to rising greenhouse gas levels
• Global warming is a type of climate change that seems to be having serious effects, such as melting glaciers and ice sheets, and changing rainfall patterns