On these diagrams, pairs of parallel lines show boundaries where plates are spreading apart, lines with ticks show boundaries where plates are colliding, and simple lines show other types of boundary. These include places where plates are simply sliding past one another, places where motions are too complex to portray simply, and places where new plate boundaries may be forming.
Some of the principal patterns of global plate motions include:
In addition to the large plates, significant small plates are labeled. Very small plates are not labeled.