Plate Tectonics

Due to their lower density and greater thickness, continental-continental convergent plate margins act quite differently than oceanic-oceanic margins. Continental crust is too light to be carried downward into a trench. At continental-continental convergent margins neither plate subducts. The two plates converge, buckle, fold, and fault to form complex mountains ranges of great height. Continental-continental convergence produced the Himalayas when the Indian-Australian plate collided with the Eurasian plate.

Continental-continental divergence causes a continent to separate into two or more smaller continents when it is ripped apart along a series of fractures. The forces of divergence literally tear a continent apart as the two or more blocks of continental crust begin slowly moving apart and magma pushes into the rift formed between them. Eventually, if the process of continental rifting continues (it may fail, leaving the continent fractured but whole), a new sea is born between the two continents. In this way rifting between the Arabian and African plates formed the Red Sea.