Much recent work in structural geology has been conducted to understand the forms of fold structures and their mode of origin. Most of this work has transpired without appeal to the principles and practice of solid mechanics. Instead, fold forms have been hypothesized to arise via motions that can be expressed by simple geometric relation. However, this approach is incapable of realizing any material under physically realistic boundary conditions. "The authors show how a relatively few general mechanisms of folding, when combined with a wide variety of conditions, can give rise to a large range of fold geometries. Three basic mechanisms are considered by which layers can become folded, namely layer parallel shortening, ramp folding and density instability.... The book focuses on folding by the mechanism of layer parallel shortening, to which four chapters are dedicated, but chapters on density instability, ramp folding and sliding on weak interfaces are also included.... [R]epresents a major contribution to structural geology and will inevitably become essential reading for students and researchers interested in the initiation and propagation of folds and diapirs." -- "Geoscientist" Arvid M. Johnson is Professor of Structural Geology and Engineering Geology in Geosciences at Purdue University.