How are mountains formed? Why are there old and young mountains? Why do the shapes of South America and Africa fit so well together? Why is the Pacific surrounded by a ring of volcanoes and earthquake prone areas while the edges of the Atlantic are relatively peaceful? Frisch and Meschede answer all these questions and more through the presentation and explanation of the geo-dynamic processes upon which the theory of continental drift is based and which have lead to the concept of plate tectonics.