Archean Greenstone Belts

The Abitibi greenstone belt of eastern Canada represents the world's largest Neoarchean terrane of supracrustal rocks. Straddling the border between the provinces of Ontario and Quebec, the belt covers an area that is approximately 700 km from southeast to northwest and 350 km from north to south. The belt is comprised of several major east-trending successions of folded volcanic and sedimentary rocks, with intervening intrusions. The supracrustal rocks of the Abitibi greenstone belt are uniquely well preserved and have mostly been overprinted only at a low metamorphic grade, allowing the study of primary geological relationships.

This book is the first comprehensive compilation of data and ideas relating to the origin, evolution, and significance of the world's greenstone belts, and includes contributions from over 100 experts. In the first of two parts, reviews are presented on broad topics relating to the geology of greenstone belts and their surroundings, covering mainly post-1980 research. These include: historical, sedimentologic, volcanic, structural, metamorphic, metallogenic, and thermal aspects; summaries of mafic/ultramafic magnetism, strain, fluids, geophysics and deep structures; relations with associated granitoids, tectonic evolution, and geochronology; and field relationships. The second part takes a more focused look at the geology of specific cratons and individual greenstone belts worldwide, including Archaean, Proterozoic, and Phanerozoic examples. Detailed geologic maps on large and small scales, extensive tabulations of data, and short written summaries of the salient features are included for all belts. The book will be a valuable reference tool for academic and industrial researchers, students, explorationists, and anyone interested in the evolution of Earth processes over geologic time.

This book provides a comprehensive overview of the evolution of one of the oldest and best-exposed Archaean cratons on this planet. There is currently a renewed interest in the early Earth, and the Kaapvaal craton has long served as a model for early crustal evolution. This unique multidisciplinary resource features information on geology, tectonics, geochemistry, and geochronology. It offers a wealth of new data on various aspects of the craton as well as contributions on the various crustal units by international specialists.

This book presents an integrated approach to the study of the evolution of the Archean lithosphere, biosphere and atmosphere, and as such it is a unique contribution to our understanding of the early Earth and life. The structural and geochemical make-up of both the oceanic and continental crust of the Archean Earth is documented in some case studies of various cratons, and the implications of the Phanerozoic plate and plume tectonic processes for the Archean geology are discussed in several chapters in the book. All chapters are process-oriented and data-rich, and reflect the most recent knowledge and information on the Archean Earth. The interdisciplinary approach of examining the evolution of the Archean crust, oceans, and life that we adopt in this book sets it apart from previous publications on Precambrian geology. The book will be attractive to researchers in academia and in industry, and to senior undergraduate students, graduate students and faculty in earth and natural sciences.

Processes and Ore Deposits of Ultramafic-Mafic Magmas through Space and Time focuses on the fundamental processes that control the formation of ore deposits from ultramafic-mafic magmas, covering chromite, platinum-group element (PGE), Ni-sulfides and Ti-V-bearing magnetite. The exploration, exploitation and use of these magmatic ores are important aspects of geology and directly linked to the global economy. Magmatic ores form from ultramafic-mafic magmas and crystallize at high-temperature after emplacement into crustal magma chambers, and are genetically linked to the evolution of the parental magmas through space and time. This book features recent developments in the field of magmatic ore deposits, and is an essential resource for both industry professionals and those in academia. - Elucidates the relationships between tectonic settings and magmatic ore mineralization - Provides the links between magma generation in the mantle and ore mineralization at crustal levels - Features the latest research on changing patterns in magmatic ore mineralization through time and their bearing on the chemical evolution of the Earth's mantle

A study on the Bellingwe Greenstone Belt, presenting the stratigraphy of the belt, its structure and tectonic setting, the sedimentology of what may be a rift basin, the geochemistry of the freshest Archaean komatiites yet found, and models of the evolution of the region.

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.

Large igneous provinces (LIPs) are intraplate magmatic events, involving volumes of mainly mafic magma upwards of 100,000 km3, and often above 1 million km3. They are linked to continental break-up, global environmental catastrophes, regional uplift and a variety of ore deposit types. In this up-to-date, fascinating book, leading expert Richard E. Ernst explores all aspects of LIPs, beginning by introducing their definition and essential characteristics. Topics covered include continental and oceanic LIPs; their origins, structures, and geochemistry; geological and environmental effects; association with silicic, carbonatite and kimberlite magmatism; and analogues of LIPs in the Archean, and on other planets. The book concludes with an assessment of LIPs' influence on natural resources such as mineral deposits, petroleum and aquifers. This is a one-stop resource for researchers and graduate students in a wide range of disciplines, including tectonics, igneous petrology, geochemistry, geophysics, Earth history, and planetary geology, and for mining industry professionals.

"Inspired by a GSA Penrose Conference held in Lander, Wyoming, June 14-18, 2006, this volume discusses the beginning and evolution of plate tectonics on Earth, and gives readers an introduction to some of the uncertainties and controversies related to the evolution of the planet. In the first three sections of the book, which cover isotopic, geochemical, metamorphic, mineralization, and mantle geodynamic constraints, a variety of papers address the question of when "modern-style" plate tectonics began on planet Earth. The next set of papers focuses on the geodynamic or geophysical constraints for the beginning of plate tectonics. The volume's final section synthesizes a broad range of evidence, from planetary analogues and geodynamic modeling, to Earth's preserved geologic record. This work provides an excellent graduate level text summarizing the current state of knowledge and will be of interest to a wide range of earth and planetary scientists."--Publisher's website.