Characterization of Ore-Forming Systems from Geological, Geochemical and Geophysical Studies


Book Description

Economically viable concentrations of mineral resources are uncommon in Earth’s crust. Most ore deposits that were mined in the past or are currently being extracted were found at or near Earth’s surface, often serendipitously. To meet the future demand for mineral resources, exploration success hinges on identifying targets at depth. Achieving this requires accurate and informed models of the Earth's crust that are consistent with all available geological, geochemical and geophysical information, paired with an understanding of how ore-forming systems relate to Earth’s evolving structure. Contributions to this volume address the future resources challenge by (i) applying advanced microscale geochemical detection and characterization methods, (ii) introducing more rigorous 3D Earth models, (iii) exploring critical behaviour and coupled processes, (iv) evaluating the role of geodynamic and tectonic setting and (v) applying 3D structural models to characterize specific ore-forming systems.










Lamprophyres


Book Description

Following their recognition by GUmbel (1874), lamprophyres were treated for an entire century as little more than obscure curiosities. Although this situation has changed recently, with a flowering of publications and active workers, lamprophyres remain almost the only group of igneous rocks which have not yet received attention in a dedicated monograph. In five exploratory reviews (1977-1987), the writer aimed to set out what was known about these rocks. The lUGS Subcommission on igneous rock systematics had meanwhile presented its nomenclatural framework (Streckeisen 1979). All this has now been overtaken by a recent explosion of interest, epitomized not least by lamprophyres' greater prominence in the 4th International Kimberlite Conference Proceedings. More data have become available since 1985 than over the entire previous century, and it is obviously impossible for such an extraordinary outpouring to be fully reviewed in this first, preliminary book. At the risk of dissatisfying some readers, therefore, this book concentrates on factual matters, and on a broad overview rather than minutiae. Because not even a world map of known lamprophyres was previously available, almost half the book is deliberately taken up by the first global lamprophyre compilation, and its commensurately extensive Bibliography. Such a compendium of largely objective information is believed to be of more immediate interest and lasting value than a premature pottage of petrogenetic polemic. Chapters 1-7 bring previous studies up to date, and concentrate on factual information.




The Geology of Gold Deposits


Book Description

Includes detailed and technical discussions of deposits in Canada, Zimbabwe, South Africa, Australia, Chile, United States, Japan, and Czechoslovakia.




Archean Crustal Evolution


Book Description

The integration of Tectonics/Geochemistry, up-to-date reviews by leading scientists as well as a broad topical coverage of the Archean, are some of the features of this particular volume. As geochronology has progressed in the last 20 years, the Archean has continued to attract interest. Advancements in the understanding of Archean crustal and mantle evolution have progressed rapidly since the first International Archean Symposium in Western Australia (1970). The landmark for the Archean was the NATO Advanced Study Institute at Leicester (1975). At this meeting the Archean truly "came of age". Investigators from many different disciplines focused their expertise on the early history of the earth. For the first time, the nature of the atmosphere, oceans, and life during the Archean was an important part of an Archean symposium. During the most recent Archean Symposium in Perth in 1990, there was a shift in interest from field and trace element data to the new rapidly evolving high-precision U/Pb geochronology of Archean rocks and to detailed structural studies of both low and high grade Archean terrains. The terrane concept so widely applied to the Phanerozoic was proposed for the Archean Yilgarn Province in Western Australia and is now widely accepted for the Archean (as evident by the articles in this book). Plate tectonics is now widely accepted as the principal process that controls the history of continents and oceans. There are, though, well substantiated differences between Archean and post-Archean rocks that indicate that Archean tectonic regimes must have differed in some respects from modern ones. The question of how and to what degree did Archean plate tectonics differ from modern plate tectonics is treated in many of the chapters of this book. Altogether, the editor has presented a selection of articles that provide a fascinating insight into the latest observations in this field.