Most large scale, high-energy events of geologic activity (e.g.earthquakes, volcanoes, and mountain building) occur as a result of relative motion along plate boundaries.
Major features of convergent boundaries include collision zones (folded and thrust-faulted mountains) and subduction zones (volcanoes and trenches). Major features of divergent boundaries include mid-ocean ridges, rift valleys, fissure volcanoes, and flood lavas. Major features of transform boundaries include strike-slip faults.
A volcano is an opening where magma erupts onto Earth’s surface. Most volcanic activity is associated with subduction, rifting, or seafloor spreading. Hot spot volcanic activity, such as volcanic islands, is exceptional in that it is not related to plate boundaries but derived from a deep, localized heat source.