Tectonic plate boundary types. Diagram showing three types of movement (arrows) at tectonic plate boundaries. Tectonic plates moving parallel to each other (bottom) lead to strike-slip earthquakes with relatively little deformation. At a divergent boundary (middle), such as a mid-ocean ridge or rift valley, the plates move apart and molten rock (orange) rises to form new land. At a convergent boundary (top), such as a subduction zone, one plate moves under the other as they collide (thrust or reverse faulting). This also leads to the formation of mountain ranges and volcanoes along the boundary as the subducting plate melts.