Plate Tectonics

The word "tectonics," derived from the Greek word tekton meaning "builder," describes the field of study within geology that involves the deformation of Earth's lithosphere (solid portion of the earth, the crust)—both the causes of deformation and its effects. Although tectonics focuses primarily on mountain building, it involves other unrelated activities as well. Since the development of the plate tectonics theory, tectonics has become an especially active area of research in geology.

Plate tectonics is the theory that explains geologic changes caused by the movement of lithospheric plates over the asthenosphere (the molten, ductile, upper portion of Earth's mantle). The visible continents, only one part of the lithospheric plates upon which they ride, shift slowly over time as a result...