This proceedings book represents a collection of conference papers examining the fundamental problems of deep magmatism.Enriched mantle reservoirs can be the source of the most massive apatite and rare metal deposits. Additionally, this book also presents some of the characteristics of kimberlites' composition from the deep Yubileinaya pipe and the mineralogical features of the Nakyn kimberlite field (Yakutia) and the crystallochemical features of rare and complex silicates from charoite rocks of the deep Murunskii massif in South Africa and the comendites of Mongolia.
Phoscorites are dark, often very handsome, sometimes economically valuable, magnetite-apatite-silicate rocks, almost always associated with carbonatite. They are key to understanding the longstanding question of how carbonate and carbonate-bearing magmas rise to the crust and the Earths surface. Despite this, they have been given little attention; a search on geological literature databases will produce thousands of references to carbonatite (up to 4125 on Georef) but not more than thirty references to phoscorite. This book goes some way to redress this balance. Over recent years many European and North American scientists have studied Kola rocks in collaboration with Russian colleagues. The idea for this book came from one such project funded by the European organisation, INTAS (Grant No 97-0722). The Kola Peninsula is one of the outstanding areas in the World for the concentration and economic importance of alkaline rocks. However, Russian work on the Kola complexes is still relatively unknown and a particular aim of this book, as well as presenting current research, is to make this knowledge accessible to English language readers. A large exploration programme on Kola alkaline rocks was active from 1950 to 1990 and involved teams of geologists who studied many kilometres of drill core and carried out detailed mineralogical and petrological studies.
This study documents alkaline rock occurrences in British Columbia; describes their petrography, geochemistry, economic geology, and field relationships; and determines the timing and tectonic controls of emplacement, providing a basis for future, detailed studies. Work was begun in 1984 and included field mapping during the summers of 1984, 1985, and 1986. All the carbonatite-syenite localities (with the exception of the Wicheeda Lake and Mount Bisson showings) and a large number of the diatreme breccias were mapped and sampled.
During the last few years, carbonatites have received a considerable amount of attention. Some of this interest was no doubt kindled by the importance of volatiles in the Earth's mantle, particularly CO , by the fact that carbonatites 2 can be used to monitor the chemical evolution of the sub-continental upper mantle, and by the fact that carbonatites may be effective metasomatizing agents at both mantle and crustal levels. The interest in Oldoinyo Lengai has extended over at least 100 years, but it was not until the eruptions of 1960, when the unique carbonatitic nature of its lavas was recognized, that the volcano took on special significance in volcanology and igneous petrology. The recognition of carbonatitic flows coin cided with the first successful laboratory experiments carried out on carbonatitic melts. Since then, Oldoinyo Lengai has formed a cornerstone in all carbonatite discussions. It is probably true to say that the findings from Oldoinyo Lengai have dominated our ideas about carbonatites, in spite of the fact that the alkali rich, natrocarbonatitic lavas of Oldoinyo Lengai are markedly different from other carbonatites.
This book reviews the geochemical and petrological characteristics of potassic igneous rock complexes, and investigates the various tectonic settings in which these rocks occur. The authors provide an overview and classification of these rocks and elucidate the geochemical differences between barren and mineralized potassic igneous complexes. High-K rocks are genetically associated with a number of epithermal gold and porphyry copper-gold deposits. In recent years, there has also been growing recognition of an association of such rocks with iron-oxide copper-gold (IOCG) deposits, intrusion-related gold deposits (IRGDs) and Carlin-type gold deposits. This fifth updated and expanded edition incorporates new data and references from world-class copper and gold deposits worldwide. It also includes the latest publications on the petrogenesis of high-K magmatism and related mineral deposits. Numerous new representative ore photographs of the mineral deposits described are also included in the new edition. As such, the book offers a valuable guide not only for academic petrologists working on alkaline rocks, but also for exploration geologists prospecting for epithermal gold and/or porphyry copper-gold deposits in modern and ancient terrains.
Encyclopedia of Geology, Second Edition presents in six volumes state-of-the-art reviews on the various aspects of geologic research, all of which have moved on considerably since the writing of the first edition. New areas of discussion include extinctions, origins of life, plate tectonics and its influence on faunal provinces, new types of mineral and hydrocarbon deposits, new methods of dating rocks, and geological processes. Users will find this to be a fundamental resource for teachers and students of geology, as well as researchers and non-geology professionals seeking up-to-date reviews of geologic research. Provides a comprehensive and accessible one-stop shop for information on the subject of geology, explaining methodologies and technical jargon used in the field Highlights connections between geology and other physical and biological sciences, tackling research problems that span multiple fields Fills a critical gap of information in a field that has seen significant progress in past years Presents an ideal reference for a wide range of scientists in earth and environmental areas of study
The alkaline igneous rocks and carbonatites are compositionally and mineralogically the most diverse of all igneous rocks and, apart from their scientific interest, are of major, and growing, economic importance. They are important repositories of certain metals and commodities, indeed the only significant sources of some of them, and include Nb, the rare earths, Cu, V, diamond, phosphate, vermiculite, bauxite, raw materials for the manufacture of ceramics, and potentially Th and U. The economic potential of these rocks is now widely appreciated, particularly since the commencement of the mining of the Palabora carbonatite for copper and a host of valuable by-products. Similarly, the crucial economic dominance of rare earth production from carbonatite-related occurrences in China, has stimulated the world-wide hunt for similar deposits. This volume describes and provides ready access to the literature for all known occurrences of alkaline igneous rocks and carbonatites of Antarctica, Asia and Europe excluding the former USSR, Australasia and oceanic islands. More than 1,200 occurrences from 59 countries are outlined together with those of 57 oceanic islands and island groups. The descriptions include geographical coordinates and information on general geology, rock types, petrography, mineralogy, age and economic aspects with the principal references cited. There are 429 geological and distribution maps and a locality index. As has been demonstrated by the three earlier volumes, the present book is likely to be of considerable interest to mineral exploration companies, as there are no comprehensive published reviews of the economic aspects of the alkaline rocks. It will also interest research scientists in the fields of igneous petrology and volcanology, and geologists concerned with the regional distribution of igneous rocks and their geodynamic relationships.
courses more petrogenesis-orientated are im My main objective in writing this book has been to mediately confronted with a basic problem; the review the processes involved in present-day mag ma generation and their relationship to global average student does not have a strong enough tectonic processes. Clearly, these are fundamental background in geochemistry to understand the to our understanding of the petrogenesis of ancient finer points of most of the relevant publications in volcanic and plutonic sequences, the original tec scientific journals. It is virtually impossible to fmd tonic setting of which may have been obscured by suitable reading material for such students, as most subsequent deformation and metamorphism. authors of igneous petrology textbooks have de Until fairly recently, undergraduate courses in liberately steered clear of potentially controversial igneous petrology tended to follow rather classical petrogenetic models. Even the most recent texts lines, based on the classification of igneous rocks, place very little emphasis on the geochemistry of descriptive petrography, volcanic landforms, types magmas erupted in different tectonic settings, of igneous intrusions and regional petrology . despite extensive discussions of the processes re However, the geologist of the late 1980s requires, in sponsible for the chemical diversity of magmas.
