The divergent boundaries are formed when the tectonic plate move away from each other. It forms volcanic islands that occur when the plates move away in order to produce gaps that are filled by molten lava.
The divergent boundary contributes to the formation of seafloor spreading. When the plates that are made up of oceanic crust move away from each other, a crack in the ocean floor appears. Then the magma oozes out from the mantle to fill that crack that results in ocean ridges.
