A divergent boundary is a linear feature that exists between two tectonic plates that are moving away from each other. These boundaries can be found on continental or oceanic lithosphere. Divergent boundaries within continents initially produce rifts, which eventually become rift valleys. Most active divergent plate boundaries occur between oceanic plates and exist as mid-oceanic ridges. At divergent boundaries, two plates move away from each other and the space that this creates is filled with new crustal material sourced from molten magma that forms below. The origin of new divergent boundaries at triple junctions is sometimes thought to be associated with the phenomenon known as hotspots. Divergent boundaries can create massive fault zones.

Some key features of divergent boundaries are:

• Earthquakes: Earthquakes are common along divergent boundaries.
• Magma: Magma (molten rock) rises from the Earth’s mantle to the surface, solidifying to create new oceanic crust.
• Continental Rift Valleys: A continental rift valley is a region where the continental lithosphere is weakening and stretching apart. It is an observable divergent boundary and a sign that a continent is breaking apart. Given enough time, the rifting will continue to a point in which the continental lithosphere will become so thin, it will become predominantly enriched in the mantle plume materials. At that point, the rift will have created brand new oceanic crust, and a newborn ocean basin will open between the continental fragments.

Divergent boundaries are one of the four types of plate boundaries, the others being convergent boundaries, transform boundaries, and plate boundary zones.