Tectonic Plate Rotation and Slab Rollback Theories - Paperback

by William A. Szary M. S. (Author)

Tectonic plates motion occurs across a sphere's surface as a rotation about some pole that passes through the center of a sphere. This pole is called a Euler Pole. Plates cannot be translated, only rotated about some axis. Plate trenches tend to migrate sometimes rotating resulting in back arc rifting. Mantle plumes induce plate rotation triggering the initial subduction process. Continental fragments develop in response to subduction collision. Slab trench rollback results from subduction trench collision with resistance coming from continental crust.

Chapter 1 defines a Euler Pole. Chapter 2 presents a kinematic model of plate motion applying the concepts of toroidal and poloidal motions in a sphere. Chapter 3 presents trench migration, net rotation, and slab-mantle coupling. Chapter 4 ties rapid microplate rotation with back arc rifting at the transition point between collision and subduction offering examples at convergent plate boundaries. Chapter 5 discusses plume induced plate rotation which triggers subduction initiation. Chapter 6 discusses the formation of continental fragments in subduction settings using the Mediterranean Sea as an example. Chapter 7 presents steady rotation of the Cascade Arc with rotation of Southwest Washington state as an example. Chapter 8 discusses trench slab rollback mechanics and processes. Discussion of slab rollback instability and supercontinent dispersion, and impacts of slab rollback on the Earth's surface using examples of the North American Cordilleran, Cascade Arc slab rollback, and the California Sierra Foothills Terrane tectonic model.