Contractional theory, continental drift and plate tectonics

Abstract

Earth’s tectonic system concerns the movement of the lithosphere, the relatively brittle outermost solid Earth, which consists of a mosaic of independent plates. The boundaries of these plates are the most dynamic areas in the world and are the locations of most orogeneses, a word from the classical Greek meaning mountain building. The concepts embraced above define the field of geodynamics – energy, forces, and motion of a changing Planet Earth; mountains are the most obvious results of this system. Although nearly all geologically recent and many ancient mountain ranges are at obvious plate boundaries, all continental crust was at some time generated at plate margins, an observation that clearly relates the global phenomenon of mountain building and plate tectonics.