According to the commonly accepted description of plate movement, all the continents once formed part of an enormous single land mass called Pangaea. This mass was surrounded by a giant ocean known as Panthalassa. About 200 million years ago, Pangaea began to break up into two large masses called Gondwanaland and Laurasia. These masses, in turn, broke up into the continents, which drifted to their present locations. Evidence of plate movement.
Earth scientists find much evidence of plate movement at the boundaries of plates.
They study surface features, such as mountains and ocean trenches, and investigate the frequencies and locations of earthquakes and volcanic eruptions. Volcanoes that rise within plates are also evidence of plate movement. Scientists believe that these volcanoes are caused by mantle plumes, columns of very hot mantle that rise from deep inside the earth to the base of the lithosphere. These plumes generate magma that rises through the lithosphere and erupts in places called hot spots. As a plate moves over a hot spot, the spot can generate a chain of volcanoes.