This book is an attempt to present a readily accessible, up-to-date and integrated introduction to organic geochemistry, at a reasonable price. It does not assume any particular specialist knowledge other than some basic chemistry and is intended to serve as a text for both undergraduate and postgraduate courses in which organic geochemistry is an important component. It may also be found a useful companion by experienced scientists from other disciplines who may be moving into the subject for the first time. In a book of this size it is not possible to discuss all aspects of organic geochemistry, and emphasis has been placed on the formation of organic-rich sedimentary deposits. While this approach will be of particular relevance to those interested in petroleum exploration, the important area of environmental geochemistry has also received consideration.