Earthquakes and volcanism occur as a result of plate tectonics. The movement of tectonic plates themselves is largely driven by the process known as subduction. The question of how new active subduction zones come into being, however, is still under debate. An example of this is the volcanic Lesser Antilles arc in the Caribbean.
Click here for original story, Plate tectonics in the Pacific and Atlantic during the Cretaceous period shaped the Caribbean region
Source: Phys.org