Types of Plate Boundaries
By: Maci Hough
Convergent Plate Boundaries
Convergent plate boundaries are when two (or more) plate boundaries move toward one another and collide. Earthquakes and volcanoes are common near these boundaries.
- Oceanic-oceanic is a convergent subtype. When two oceanic plates converge deep ocean ridges are formed. They also result in undersea volcanoes and island arcs.
- Continental-continental is another. When two plates containing continental crust collide, both are too light to subduct. In this case, a continent-continent collision occurs, creating especially large mountain ranges.
- Oceanic-continental is the last. The oceanic crust is over ridden by the thicker continental crust. At a certain depth materials begin a process of partial melting.
Divergent Plate Boundaries
Divergent boundaries occur when two plates move away from one another.
- Rift (land) is a divergent subtype. In the earliest stages of rifting, causing the rise of the asthenosphere, and the thinning of the subcrustal continental lithosphere.
- Ridge (ocean) is the other subtype. An underwater mountain system that consists of various mountain ranges (chains), typically having a valley known as a rift running along its spine, formed by plate tectonics.
Transform boundaries are when two plates slide next to one another in opposite or same direction. Many transform boundaries are found at the sea floor. Large earthquakes can occur in the result of transform boundaries. The plates are pushing against each other. The crust is neither produced not destroyed.