Plate tectonics at the treshold of middle age

Abstract

Plate tectonics has been in the foreground of geological thinking for almost twenty years. It has proved to be an immensely useful concept and its consequences, especially for the history of the earth and life, have by no means been fully explored. As is inevitable with any comprehensive theory, however, flaws are also beginning to show, mainly in the form of a growing of ad hoc modifications which cast doubt on the claim that this is the ultimate unifying new global tectonics. What the future shall bring is a matter of conjecture, but any new dynamic theory of the earch is certain to include continental drift.