Topic summary
Slab rollback
Extracted from the Wikipedia article Oceanic trench.
Processes involved
Slab rollback is not always a continuous process suggesting an episodic nature. The episodic nature of the rollback is explained by a change in the density of the subducting plate, such as the arrival of buoyant lithosphere (a continent, arc, ridge, or plateau), a change in the subduction dynamics, or a change in the plate kinematics. The age of the subducting plates does not have any effect on slab rollback. Nearby continental collisions have an effect on slab rollback. Continental collisions induce mantle flow and extrusion of mantle material, which causes stretching and arc-trench rollback. In the area of the Southeast Pacific, there have been several rollback events resulting in the formation of numerous back-arc basins.