At a divergent plate boundary, two tectonic plates are moving away from each other. The movement creates a gap or rift between the plates, and the area where the plates separate is filled with molten rock from the Earth's mantle. This molten rock, called magma, rises to the surface and cools, solidifying to form new crust. This process leads to the formation of new oceanic crust in the case of divergent boundaries occurring under the ocean, or to the formation of rift valleys and the eventual creation of new continents in the case of continental divergent boundaries.
