This wide-ranging text in isotope geology/geoscience allows students to integrate material taught in various courses into a unified picture of the earth sciences. Gives a rational exposition of the principles used in the interpretation of isotopic data and shows how such interpretations apply to the solution of geological problems. Current with references up to 1985, chapters in this edition have been revised, and new chapters on Sm-Nd, Lu-Hf, Re-Os, and K-Ca decay schemes and cosmogenic radionuclides have been added. Data summaries and references have been expanded. Also includes problems for student study and abundant line drawings with explanatory captions.