In the mid 1960s J Tuzo Wilson formalised some key concepts in plate tectonics. Especially he showed that continents show a cyclic history of rifting - drifting and collision, followed by rifting again. He saw that the modern north Atlantic had been preceded by rifting which itself formed roughly along the site of an old mountain range ("mobile belt") that was it turn formed by the collision between two ancient continents (that we now call Laurentia and Avalonia). Use this diagram to find examples of the various parts of the Wilson Cycle in the modern world.