Over the past several decades, environmental issues and problems have become an important area of study occupying scientists from a number of disciplines. This textbook is  written for geoscience and environmental science students who are interested in the interactions between anthropogenic activities and the natural environment.

The problem of application of geochemical methods in prospecting for metals has become progressively more urgent in recent years. Credit ought to be given to our geophysicists, who were the first to raise this problem and also the first to undertake its solution.

This book is designed to be used as an introduction to geochemistry by undergraduate and graduate chemistry and geology students as well as by those from other sciences. It summarizes the significant facts and ideas concerning the chemistry of the earth and synthesizes these data into an account of the physical and chemical evolution ol the earth. The aim of the book is to explore an intlresting, complex, and changing subject. An attempt has !'een made to cover the entire field of geochemistry. However, not alI subjects have been coveredwith equal detail becauseto properly cover the facts and theories would require a volume far too long to be suitably used as a text. Some areas of geochemical interest such as phase diagrams and ore deposits have been adopted by other courses in thc geology curriculum. and thermodynamics, a key to understanding geochemical processes, requires the depth of presentation given in physical chemistry courses. <...>