Divergent boundaries 2 plates move apart Most occur at the mid ocean ridge where sea-floor spreading occurs Forms oceanic crust = Basalt When form on land = rift valley

Divergent boundaries 2 plates move apart Most occur at the mid ocean ridge where sea-floor spreading occurs Forms oceanic crust = Basalt Sea-Floor Spreading Creates oceanic crust and causes the plates to move.

Divergent boundaries 2 plates move apart Most occur at the mid ocean ridge where sea-floor spreading occurs Forms oceanic crust = Basalt When form on land = rift valley

Rift Valley

Great Rift Valley in Africa

Great Rift Valley in Africa

Convergent boundaries 2 plates come together Oceanic crust = more dense Continental crust = less dense Collisions Oceanic to continental = subducting oceanic plate

Convergent boundaries Continental to continental = mountain building

Convergent boundaries Continental to continental = mountain building Continental Crust = Granite