The collection of papers in this volume is a direct result of the Society of Economic Paleontologists and Mineralogists Research Symposium on "Thermal History of Sedimentary Basins: Methods and Case Histories" held as part of the American Association of Petroleum Geologists Annual Convention in New Orleans in March 1985. The original goal of the sym posium was to provide a forum where specialists from a variety of dis ciplines could present their views of methods that can be used to study the thermal history of a sedimentary basin or an important portion of a basin. An explicit part of that goal was to illustrate each method by presentation of a case history application. The original goal is addressed by the chapters in this volume, each of which emphasizes a somewhat different approach and gives field data in one way or another to illustrate the practical useful ness ofthe method. The significance of our relative ignorance of the thermal conductivities of sedimentary rocks, especially shales, in efforts to understand or model sedimentary basin thermal histories and maturation levels is a major thrust of the chapter by Blackwell and Steele. Creaney focuses on variations in kerogen composition in source rocks of different depositional environments and the degree to which these chem- . ically distinct kerogens respond differently to progressive burial heating.
This book introduces aqueous geochemistry applied to geothermal systems. It is specifically designed for readers first entering into the world of geothermal energy from a variety of scientific and engineering backgrounds, and consequently is not intended to be the last word on geothermal chemistry. Instead it is intended to provide readers with sufficient background knowledge to permit them to subsequently understand more complex texts and scientific papers on geothermal energy. The book is structured into two parts. The first explains how geothermal fluids and their associated chemistry evolve, and shows how the chemistry of these fluids can be used to, deduce information about the resource. The second part concentrates on survey techniques explaining how these should be performed and the procedures which need to be adopted to ensure reliable sampling and analytical data are obtained. A geothermal system requires a heat source and a fluid which transfers the heat towards the surface. The fluid could be molten rock (magma) or water. This book concentrates on the chemistry of the water, or hydrothermal, systems. Consequently, magma-energy systems are not considered. Hot-dry rock (HDR) systems are similarly outside the scope of this text, principally because they contain no indigenous fluid for study. Both magma-energy and HDR systems have potential as energy sources but await technological developments before they can be exploited commercially. Geothermal systems based on water, however, are proven energy resources which have been successfully developed throughout the world.
Volume 65 of Reviews in Mineralogy and Geochemistry attempts to fill this gap and to explicitly focus on the role that co-existing fluids play in the diverse geologic environments. It brings together the previously somewhat detached literature on fluid–fluid interactions in continental, volcanic, submarine and subduction zone environments. It emphasizes that fluid mixing and unmixing are widespread processes that may occur in all geologic environments of the entire crust and upper mantle. Despite different P-T conditions, the fundamental processes are analogous in the different settings.