Book excerpt: Updated throughout with the latest data and findings, the Second Edition of Essentials of Geochemistry provides students with a solid understanding of the fundamentals of and approaches to modern geochemical analysis. The text uses a concepts of chemical equilibrium approach, which considers the reactions that occur as a result of changes in heat production and pressure within the Earth to introduce students to the basic geochemical principles. This text is for those who want a quantitative treatment that integrates the principles of thermodynamics, solution chemistry, and kinetics into the study of earth processes. This timely text contains numerous examples and problems sets which use SUPCRT92 to allow students to test their understanding of thermodynamic theory and maximize their comprehension of this prominent field. New sections introduce current “hot” topics such as global geochemical change with the short and long term carbon cycle, carbon isotopes and the Permo-Triassic extinction event, kinetics and the origin of life and the use of boron and nitrogen isotopes.