This monograph discusses the major problems relating to the surface environment by using clay mineralogy as a unifying theme. Since the stability and development of illite, the most abundant and most common clay mineral, is the key to surface mineral dynamics, understanding its structure and transformation is an absolute prerequisite to understanding the problems of environmental change. Using illite as the frame, the authors describe problems in soil chemistry, clay stability and clay kinetics in sedimentary rocks. This book is valuable for graduate students, scientists and researchers in the fields of sedimentology, sediment petrography and soil sciences.