From Aa toZweikanter, this popular dictionary has now been revised and updated. This edition includes over 1,000 new terms plus: -accurate definitions without technical jargon -many word origins -hyphenation and pronunciation guide -commonly used abbreviations -a geologic time and life chart The definitions in this book are drawn largely from the autoritative 36,000-term Glossary Of Geology, to which nearly 150 specialists from all fields of the geosciences contributed. Both the Glossary and this Dictionary were prepared as a service of the American Geological Institute, a federation of geoscience societies united to provide information to the science community and the public.