Plate Tectonics

When two plates move away from each other.  Find mostly Volcanoes, and mid-oceanic ridges. (can sometimes find small earthquakes) An example is on the Eurasian Plate/ North America.

When the heavier oceanic crust slides under the lighter, less dense continental crust. Causes both volcanoes and earthquakes. An example is South America/Pacific.

When two continental crust plates meet. As they are the same density unable to slide against each other. Most common is fold mountains and earthquakes. An example is Indio-Australian/Eurasain 

when two plates move alongside, causes friction as they rub together. Causes earthquakes. For example, North America/Pacific.