This text describes geological processes within the framework of plate tectonics, introducing students to the basic concepts in this constantly developing field. Recent discoveries in marine geology, geochemistry, geophysics, and planetary geology are systematically woven into discussions of traditional topics such as geomorphology, sedimentation, petrology, volcanism, and structural geology. The book describes the methods and techniques employed by geologists in the field, relating geologic subjects to environmental problems. Learning aids include a separate introduction for each of the book's three parts, a brief abstract preceding each chapter, plus summaries in list form, exercises, and bibliographies for each chapter.