Since the first edition was published in 1983, this highly-regarded introductory textbook has been used by many generations of students worldwide. It is specifically tailored to the requirements of first or second year geology undergraduates. The third edition has been extensively revised and updated to include many new sections and over 50 new or redrawn illustrations. There are now over 220 illustrations, many incorporating a second colour to highlight essential features. The format has been changed to enhance the visual attractiveness of the book. The tripartite organization of the first and second editions has been modified by combining the purely descriptive or factual aspects of fault and fold structure in the earlier chapters with a simple treatment of mechanisms, leaving the more geometrically complex treatment until after the relevant sections on stress and strain, as before. Some subjects are introduced for the first time, e.g. inversion and orogen collapse, and others have been extensively modified, e.g. the chapter on gravity controlled structures now emphasises modern work on salt tectonics. The last third of the book is devoted to the wider context of geological structures and how they relate to plate tectonics. The final two chapters have been considerably expanded and give examples of various types of geological structures in their plate tectonic settings in both modern and ancient orogenic belts.