Over the past two decades there has been heightened concern about, and an improving scientific description of, the impacts of increasing carbon dioxide concentrations in Earth’s atmosphere. Despite this concern, the global rate of addition of carbon dioxide to the atmosphere by the burning of fossil fuel, now approaching 10 Gton C/yr, continues to increase, and at an accelerating rate (Fig. 1a). Although many still hope and believe that carbon emissions can be arrested at near the current rates, and decreased over the remainder of the 21st century, there is as yet little evidence that this is going to occur. <...>

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.

A broad west-to-east increase of many metal concentrations has been found in stream sediments during a reconnaissance investigation conducted in conjunction with geologic studies in the Santa Renia Fields and Beaver Peak 7–1/2 minute quadrangles near the northern end of the Carlin trend of gold deposits in the Tuscarora Mountains. This regional increase in metal concentrations coincides with a dramatic change in landform wherein high concentrations of metals in stream sediments appear to correlate directly with areas of high elevations and steep slopes in the Beaver Peak quadrangle. Robust erosion combined with high flow rates in streams from these higher elevations are envisaged to have contributed significantly to increased metal concentrations in the stream sediments by an enhanced presence of minerals with high specific gravities and a correspondingly diminished presence of minerals with low specific gravities. Minerals with low specific gravities probably have been referentially flushed down stream because of high transporting capacities for sediment by streams in the Beaver Peak quadrangle. In addition, the Carlin trend, a generally northwest-alignment of gold deposits in the Santa Renia Fields quadrangle, is well outlined by arsenic concentrations that include a maximum of approximately 54 parts per million. Further, a weakly developed distal-to-proximal metal zonation towards these gold deposits appears to be defined respectively in plots showing distributions of thallium, arsenic, antimony, and zinc. A broad area of high metal concentrations—including sharply elevated abundances of Ag, As, Au, Cd, Co, Cu, Mn, Ni, P, Sb, Sc, Te, V, and especially Zn—near the southeast corner of the Beaver Peak quadrangle primarily could be the result of stratiform mineralized rocks in the Ordovician Vinini Formation or Devonian Slaven Chert, or the result of a subsequent Mesozoic or Tertiary epigenetic overprint. <...>