Plate Tectonics

• The 2 types of crusts

  Oceanic - Carries the ocean and is thinner and more dense

  Continental - Carries land and is thicker and less dense
• Driving forces behind plate tectonics

  1. Plasticity in upper mantle
  2. Convection currents in asthenosphere
• 3 types of plate boundaries

  Divergent - Tension

  Convergent - Compression

  Transform - Shear
• Basic Convergent Info

  1. Occurs when 2 plates move towards each other
  2. Can cause subduction of crust
  3. Can be where crust is destroyed
• Basic Divergent Info

  1. Also known as, “Spreading boundaries.”
  2. The plates are moving away from each other
  3. Can be where crust is created
• Basic Transform Info

  When 2 tectonic plates slide along each other causing earthquakes
• Oceanic - Oceanic Convergent

  1. Crust is destroyed
  2. One plate is subducted under the other
  3. Trenches and volcanic islands are formed

  Example : Mariana Trench
• Continental - Continental Convergent

  1. Crust is neither created nor destroyed
  2. Two continental plates come together and both get pushed upwards
  3. Creates folded mountains

  Example : Himalayan Mountains
• Continental - Oceanic Convergent

  1. Crust is destroyed
  2. Plates come together and the more dense plate (Oceanic) is subducted
  3. Trenches and Volcanic Mountains formed

  Example : The Andes Mountains (South America)
• Oceanic - Oceanic Divergent

  1. Crust is created (Sea floor spreading)
  2. Two ocean plates move apart causing sea floor spreading
  3. Creates Mid-Ocean Ridge

  Example : The Mid-Atlantic Ridge
• Continental - Continental Divergent

  1. Crust is neither created nor destroyed
  2. The two plates more apart
  3. Creates Rift Valley

  Example : The Great Rift Valley (Africa)
• Transform Boundaries

  1. Creates Slip Fault
  2. Usually on land with 2 continental plates

  Example : San Andreas Fault (California)