At a divergent plate boundary, two plates move apart.
At a divergent plate boundary, two plates move apart. These plates may be or oceanic plates, and the prices occurs very slowly. As the two plates pull apart from one another, the land in between the two plates breaks apart and sinks into the . The loss of this land creates a rift.
If both plates are oceanic, mantle plume rises up through the crack and sea floor spreading will occur. If the two plates are continental, a rift valley occurs like the East Africa Rift Valley: