Divergent plates move apart, commonly forming new oceanic crust at a mid-ocean ridge. Convergent plates move toward each other. Oceanic subduction can produce a trench and volcanic arc; continental collision can thicken crust into major mountain ranges. Match the movement before choosing the landform.
Transform plates slide horizontally past each other. Sudden movement after frictional locking can cause earthquakes. Earthquakes occur at divergent, convergent and transform boundaries, but not every boundary has volcanoes. Transform motion does not usually create or consume large amounts of crust in the way spreading or subduction does. Arrows moving apart, together or past are the key recognition clues.
Example 1
Two oceanic plates move apart and new crust forms between them. Name the boundary and feature.
A divergent boundary with a mid-ocean ridge or spreading centre.
Example 2
An oceanic plate descends below another plate beside a deep trench. Name the process.
Subduction at a convergent boundary. Melting-related processes can also support a volcanic arc above the descending plate.
Watch out: Volcanism is common in some divergent and subduction settings, but continental collision and transform boundaries do not generally produce the same volcanic pattern.