This edited work contains the most recent advances related to the study of layered intrusions and cumulate rocks formation. The first part of this book presents reviews and new views of processes producing the textural, mineralogical and geochemical characteristics of layered igneous rocks. The second part summarizes progress in the study of selected layered intrusions and their ore deposits from different parts of the world including Canada, Southwest China, Greenland and South Africa. Thirty experts have contributed to this update on recent research on Layered Intrusions. This highly informative book will provide insight for researchers with an interest in geology, igneous petrology, geochemistry and mineral resources.
Acknowledgements xix pioneering workers on igneous layering in Greenland xx Wbrkshop participants xxii Henning Sfl!rensen, University of Copenhagen, Dermark. Latte Melchior Larsen, Geological SUrvey of Greenland, Copenhagen, Dermark. Abstract 1 1 • Introduction 1 1. 1 The agpaitic rocks of the Ilimaussaq intrusion 3 2. Igneous layering in the Ilimaussaq intrusion 4 3. Mineralogy of the layered kakortokite series 15 4. Chemistry of the layered kakortokite series 19 5. Origin of the kakortokite layering 20 5. 1 Discussion 22 6. Conclusion 25 References 26 2. I. AYERn«;r CCMPl\CTIOO NID PCBJ. "--MN}tATIC ~ IN '!HE KLOKKEN INTRUSIOO 29 Ian Parsons and SUsanne M. Becker, University of Aberdeen, U. K. Abstract 29 1. Introduction 30 2. Age of the intrusion 31 3. General structure and mineral variation 31 vi TABLE OF CONTENTS 3. 1 Nomenclature of rock types 31 3. 2 Bulk chemical and modal variation 36 4. The contacts and wall-rocks 37 4. 1 Guter contact 37 4. 2 The gabbro sheath 37 4. 3 The unlaminated syenite sheath 39 4. 4 The gabbro-syenite transition 41 5. The layered series 43 5. 1 General relationships 43 5. 2 Granular syenites 43 5. 2. 1 Structure and cryptic variation 43 5. 2. 2 Origin of granular layers 46 5. 2. 3 Trace elements and chamber dlinensions 47 5. 3 Laminated syenites 48 5. 3. 1 General features 48 5. 3. 2 Mineral layering 51 5. 3.
Written by leading experts in the field, this work summarises the important aspects relating to layered intrusions, with almost universal coverage of the subject.Each chapter is a complete review of a theme or specific geological intrusion. The first part of the book covers the general principles and processes which apply to all intrusions. Those chapters on individual intrusions concentrate on factual information.A detailed full colour geological map of the Skaergaard intrusion is also included.This book will appeal to a wide audience - university libraries, research students in igneous petrology, state organisations such as exploration companies - as well as being an ideal textbook for university courses on igneous petrology, and geochemistry and petrography.
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
Mineral deposits have supplied useful or valuable material for human consumption long before they became objects of scientific curiosity or commercial exploitation. In fact, the earliest human interest in rocks was probably because of the easily accessible, useful (e. g. , red pigment in the form of earthy hematite) or valuable (e. g. , native gold and gemstones) materials they contained at places. In modem times, the study of mineral deposits has evolved into an applied science employing detailed field observations, sophisticated laboratory techniques for additional information, and computer modeling to build complex hypotheses. Understanding concepts that would someday help geologists to find new mineral deposits or exploit the known ones more efficiently have always been, and will continue to be, at the core of any course on mineral deposits, but it is a fascinating subject in its own right, even for students who do not intend to be professional economic geologists. I believe that a course on mineral deposits should be designed as a "capstone course" that illustrates a comprehensive application of concepts from many other disciplines in geology (mineralogy, stratigraphy and sedimentation, structure and tectonics, petrology, geochemistry, paleontology, geomorphology, etc. ). This book is intended as a text for such an introductory course in economic geology, primarily for senior undergraduate and graduate students in colleges and universities. It should also serve as a useful information resource for professional economic geologists.
A comprehensive account of ore-forming processes, revised and updated The revised second edition of Introduction to Ore-Forming Processes offers a guide to the multiplicity of geological processes that result in the formation of mineral deposits. The second edition has been updated to reflect the most recent developments in the study of metallogeny and earth system science. This second edition contains new information about global tectonic processes and crustal evolution that continues to influence the practice of economic geology and maintains the supply of natural resources in a responsible and sustainable way. The replenishment of depleted natural resources is becoming more difficult and environmentally challenging. There is also a change in the demand for mineral commodities and the concern around the non-sustainable supply of ‘critical metals’ is now an important consideration for planners of the future. The book puts the focus on the responsible custodianship of natural resources and the continuing need for all earth scientists to understand metallogeny and the resource cycle. This new edition: Provides an updated guide to the processes involved in the formation of mineral deposits Offers an overview of magmatic, hydrothermal and sedimentary ore-forming processes Covers the entire range of mineral deposit types, including the fossil fuels and supergene ores Relates metallogeny to global tectonics by examining the distribution of mineral deposits in space and time Contains examples of world famous ore deposits that help to provide context and relevance to the process-oriented descriptions of ore genesis Written for students and professionals alike, Introduction to Ore-Forming Processes offers a revised second edition that puts the focus on the fact that mineral deposits are simply one of the many natural wonders of geological process and evolution.
The platinum-group elements (PGE) include platinum, palladium, rhodium, ruthenium, iridium and osmium. They are currently receiving world-wide attention as an attractive exploration target because they offer the dual attraction of rare, high value precious metals as well as major industrial applications. Platinum has aesthetic qualities, combined with a permanent lustre, which encourage its use in the manufacture of jewellery and, like gold, it also finds an investment role. Platinum, rhodium and palladium have important applications as catalysts, enabling petroleum and other fuels and chemicals to be produced efficiently from crude oil. This book gives a practical set of guidelines for implementing a programme of PGE exploration, detecting subtle indications of mineralization and assessing the economic potential of a group of mafic or ultramafic rocks. Background material is given on the economic and geological framework of the PGE in the first chapter, while theoretical aspects of magma chemistry are covered in the next three. Chapters 5 and 6 review current world-wide exploration activity within the context of available reserves of PGE, and in Chapter 7 factors which need to be considered in exploration for new deposits are outlined. The last chapter discusses evaluation guidelines.As the PGE are both costly and almost indestructible they are normally recycled; nevertheless, a substantial annual input of new metal is needed to replace process losses, to permit increases in capacity in the dependent industries and to provide for new uses. For example, a major new market for platinum will be created if the European Community countries are required to fit catalytic converters to new cars. At present, South Africa and the USSR are the sources of most of the western world's newly mined PGE, with virtually all the South African production derived from the Bushveld Complex. Much of the material presented in this book is based on the author's experience of these rocks, and emphasis is given to the dominant role played by magmatic sulphides as potent collectors of PGE. Consumers of minerals and metals, however, prefer to have a diversity of supply and a new PGE producer is therefore likely to attract a ready market.Not only does the book provide a wealth of practical information for mining geologists, it also contains much of interest to those in natural resource management and investment.
