CASE STUDIES

• Divergent plate boundary

  Mid atlantic ridge- Iceland

  • oceanic-oceanic
  • Rising convection currents -> magma to surface = small , basaltic eruptions -> new oceanic plates
  • minor shallow earthquakes
• Divergent plate boundary

  African rift valley / Red sea

  • continent - continent
  • cause = geologically recent mantle plume splitting a continental plate = new ocean basin
  • basaltic volcanos
  • minor earthquakes
• convergent plate boundary

  himalayas

  • continent-continent
  • two continental land masses colliding = mountain belt as the landmasses crumble
  • infrequent major earthquakes distributed over large area
• convergent plate boundary

  Aleutian Islands , Alaska

  • oceanic-oceanic
  • one oceanic plate subducts under the other
  • frequent earthquakes
  • curving arc chain of volcanoes w/ violent eruptions
• convergent plate boundaries

  Andean mountains

  • oceanic -continental
  • ocean under continent = volcanic mountain range
  • frequent large earthquakes and violent eruptions
• conservative

  California , San Andreas fault zone

  • continental-continental
  • plates slide past each other along transform faults
  • frequent shallow earthquakes
  • no volcanic activity