This book is a contribution to the International Year of Planet Earth arising from the 33rd International Geological Congress, held in Oslo, Norway during August 2008. The first section of the book considers aspects of geochemical processes which led to the development of the solid Earth as it is today. The second portion of the book shows how the rapidly-evolving analytical tools and approaches presently used by geochemists may be used to solve emerging environmental and other societal problems. This unique collection of reviews, with contributions from a range of internationally distinguished scientists, will be invaluable reading for advanced students and others interested in the central role geochemistry in the earth sciences.