Plates are separating or moving away from each other
Mid-Ocean Ridge
Rift valleys
Two plates of similar densities collide
Two plates slide paste each other
Volcanic mountains
Two plates of different densities collide and the denser oceanic crust is forced underneath the less dense continental
Earthquakes
Sea-floor spreading
Islands
New crust
Underwater volcanoes
Volcanic islands
Fault lines
Two oceanic plates collide, and the older more dense plate is forced under
Mountains
Volcanoes
