continental drift

In geology, the theory that, about 250–200 million years ago, the Earth consisted of a single large continent (Pangaea), which subsequently broke apart to form the continents known today. The theory was first proposed in 1912 by German meteorologist Alfred Wegener, but such vast continental movements could not be satisfactorily explained or even accepted by geologists until the 1960s.

The theory of continental drift gave way to the theory of plate tectonics. Whereas Wegener proposed that continents pushed their way through underlying mantle and ocean floor, plate tectonics states that continents are just part of larger lithospheric plates (which include ocean crust as well) that move laterally over the Earth's surface.