It is now common parlance to refer to the Earth as a physical–chemical–biological system; but this is a relatively recent innovation. Until about 1950, geologists generally used the word ‘system’ to define geologic periods, or the several crystal classes, or the physical chemistry of multicomponent mixtures. Long before then, the word ‘system’ in its current usage had been a part of the vocabulary of a number of fields, including communication and control engineering.

Organic matter is associated frequently with several types of ore deposits. Examples   include   uranium  deposits,  Mississippi  Valley-type   (MVT) bad-zinc deposits, Carlin-typc disseminated gold deposits, and black shale deposits. This association has led to suggestions that the organic material has been involved in ore genesis for many metals and in differing geological environments. Until recently, however, organic geochemical studies have lagged behind inorganic geochemical approaches. The prime reason has been the analytical difficulty in resolving and identifying the range of organic compounds in geological systems. This problem was resolved in the 1960s by the successful coupling of a separation technique, gas chromatography, with a meth\od for determining molecular mass and structure, mass specttrometry. At the start of a metallogenic study, it is necessary to consider critically whether the organic matter could have been passive or active in ore genesis. If passive, considerable information still can be obtained on ore genesis. Organic matter is a sensitive recorder for many events affecting host rocks, including thermal maturation (Douglas et al., 1970), oxidation (McPhee and Nandi, 1981; Havens et al., 1983), leaching {Hunt, 1979) <...>

The review chapters in this volume were the basis for a two-day short course on nontraditional stable isotopes held prior (May 15í16, 2004) to the spring AGU/CGU Meeting in Montreal, Canada. The editors (and conveners of the short course) Clark Johnson, Brian Beard and Francis Albarède and the other chapter authors/presenters have done an exceptional job of familiarizing us with the cutting edge of this exciting fi eld of study <...>

This book is an outgrowth of my interest in the chemistry of sedimentary rocks. In teaching geochemistry, I realized that the best examples for many chemical processes are drawn from the study of ore deposits. Consequently, we initiated a course at The University of Cincinnati entitled "Sedimentary Ore Deposits," which serves as the final quarter course for both our sedimentary petrology and our ore deposits sequence, and this book is based on that teaching experience. Because of my orientation, the treatment given is perhaps more sedimentological than is usually found in books on ore deposits, but I hope that this proves to be an advantage. It will also be obvious that I have drawn heavily on the ideas and techniques of Robert Garrels.