Coated grains have always attracted attention, at first of naturalists, and later of geologists, and the interest in these peculiar bodies was re lated both to their intriguing form and their significance in facies inter pretation and sedimentology and to their relevance to accumulations of hydrocarbons and other mineral deposits. This resulted in numerous publications on this subject, and the intention of this volume is to sum marize the present state of knowledge on coated grains. The idea of the book was to unite some general papers with papers reporting case studies of both recent and ancient coated grains. The organization of the book follows this intention. The papers presented in this volume have been invited by the editor; the theme of the book merits a few words of personal history. The development of studies of coated grains during the last two decades has not only resulted in a great increase in knowledge of recent and ancient environments of coated grain formation, but also numerous important and controversial questions of classification, environmental significance, mineralogical composition etc. of ancient coated grains have arisen. To answer these questions, in 1978 I started the study of many ancient and recent occurrences of coated grains at the Institut fUr Geologie, Ruhr-UniversiUH Bochum, following the invitation of Hans Fiichtbauer and sponsored by the Alexander von Humboldt-Stiftung."

The fifth volume in this series is focused on the chemical and physical interactions between rocks undergoing metamorphism and the fluids that they generate and that pass through them. The recognition that such pro cesses can profoundly affect the course of metamorphism has resulted in a number of recent papers and we consider that it is time for a review by some of the interested parties. We hope our selection of contributors provides an adequate cross section and demonstrates some of the flavor of this rapidly developing field. A cursory examination of the volume will reveal that there are widely divergent opinions on the compositions of metamorphic fluids and on the ways in which they interact physically and chemically with the rocks through which they pass. Since our own views are extensively discussed in Chapters 4 and 8, we leave the reader to determine his own brand of the "truth. " We wish to thank D. Bird, S. Bohlen, D. Carmichael, G. Flowers, C. Foster, C. Graham, E. Perry, J. Selverstone, R. Tracy, J. Valley, and R. Wollast for their chapter reviews. Thanks are also due C. Cheverton for her editorial assistance, and the helpful staff at Springer-Verlag New York."

turning points that, in the course of a few years, have made this The uranium minerals that today are at the centre of worldwide metal an essential raw material. attention were unknown until 1780, when Wagsfort found a First, the destructive property of fission reactions made uranium a metal of fundamental strategic importance, increas pitchblende sample in 10hanngeorgenstadt. This discovery passed unnoticed, however, since Wags fort thought that it ing research in some nations, but the revolution came with the plan for the real possibility of utilizing chain reactions for contained a black species of a zinc mineral-hence the n' lme 'pitchblende' (= pitch-like blende). Seven years later, Klaproth, energy production in place of conventional fuels. while examining the mineral, noted that it contained an oxide Since that time a 'uranium race' has been in progress in many countries-often justified by the well-founded hope of of an unknown metal, which he called 'uranium' in honour of the planet Uranus, recently discovered by Herschel. Klaproth becoming self-sufficient with regard to energy, or at least of also believed that he had separated the metal, but, in fact, the paying off a part of the financial deficit due to increasing fuel imports."

Plan of Review This review of clay microstructure is aimed at the diverse group of professionals who share an interest in the properties of fine-grained minerals in sediments. During the last several decades, members of this group have included geologists, soil scientists, soil engineers, engineering geologists, and ceramics scientists. More recently, it has included significant numbers of marine geologists and other engineers. Each of the disciplines has developed special techniques for investigating properties of clay sediments that have proven to be fruitful in answering questions of central interest. Knowledge of clay microstructure-the fabric of a sediment and the physico chemical interactions between its components-is fundamental to all these disciplines (Mitchell 1956; Lambe 1958a; Foster and De 1971). Clay fabric refers to the spatial distribution, orientations, and particle-to-particle relations of the solid particles (generally those less than 3. 9 /Lm in size) of sediment. Physico-chemical interac tions are expressions of the forces between the particles. In this review, we trace the historical development of under standing clay microstructure by discussing key scientific papers published before 1986 on physico-chemical interactions in fine grained sediments and on clay fabric. Since the development follows an intricate path, the current view of clay microstructure is summarized. This summary includes a discussion of the present state of knowledge, the observations made so far, and the facts that are now established."

Marble in Ancient Greece and Rome: Geology, Quarries, Commerce, Artifacts Marble remains the sine qua non raw material of the an cient Greeks and Romans. Beginning in the Bronze Age sculptu re began in marble and throughout classical times the most im portant statues, reliefs, monuments and inscriptions were made of it. Yet, quarry sources changed in time as preferences for different marbles were influenced by local traditions, the pos sibilities of transport, esthetic tastes, and economics. Marble studies and the identification of the provenance of marble can thus reveal much about Greek and Roman history, trade, esthe tics and technology. Persons in many disciplines are studying various aspects of Greek and Roman marble usage. Geologists and geochemists are working on methods to determine the provenance of marble; ar chaeologists are noting changing patterns of import and use in excavation and discovering how improving quarrying techniques and prelimihary dressing of the extracted material influenced the final shape of artifacts; ancient historians are now under standing quarry organization and bureaucracies that controlled marble production and trade; art historians are seeing how phy sical characteristics of the stone affected the techniques and style of sculpture; architects and engineers are interested in quarry technologies and usage in building construction. These specialists drawn from many disciplines rarely have an opportu nity to compare notes and see how each can contribute to the research effort of others."

Phenomenal new observations from Earth-based telescopes and Mars-based orbiters, landers, and rovers have dramatically advanced our understanding of the past environments on Mars. These include the first global-scale infrared and reflectance spectroscopic maps of the surface, leading to the discovery of key minerals indicative of specific past climate conditions; the discovery of large reservoirs of subsurface water ice; and the detailed in situ roving investigations of three new landing sites. This an important, new overview of the compositional and mineralogic properties of Mars since the last major study published in 1992. An exciting resource for all researchers and students in planetary science, astronomy, space exploration, planetary geology, and planetary geochemistry where specialized terms are explained to be easily understood by all who are just entering the field.

Feldspar minerals make up 60% of the crust of the Earth. They are stable in the upper mantle, and are so abundant in the crust that they form the basis of the classification of igneous rocks. At the surface, feldspars weather to form clay minerals which are the most important mineral constituent of soils. The articles in this book review the chemical reactions of feldspars over the whole sweep of pressure and temperature regimes in the outer Earth, and describe the fundamental aspects of crystal structure which underlie their properties. The book covers intracrystalline reactions, such as order-disorder transformations and exsolution, and transfer of stable and radiogenic isotopes, which can be interpreted to provide insights into the thermal history of rocks. It is suitable for final year undergraduates or research workers.

PGE V-Voisey's Bay (Canada) D -Duluth Complex (USA) K-Kambalda (Australia) M-Merensky Reef (Bushveld) N -Noril'sk region (Russia) P-Pechenga(Russia) S-Sudbury (Canada) T-Thompson (Canada) J -Jinchuan (China) L-Lac des lies (Canada) PR-Platreef (Bushveld) Po-Portimo Complex (Finland) R-Raglan (Canada) U-UG-2 chromitite (Bushveld) Z-Great Dyke of Zimbabwe e-Mt Keith (Australia) . a. -Perseverance (Australia) +-Stillwater (USA) 0 0 0 'c9 -~ Ni+Co Cu Relative value of Ni+Co Fig. 1. 1. Relative va1ue of the contributions of Ni+Co, Cu and PGE to the mag- matic su1fide deposits listed in Table 1. 1 sulfide deposits are closely related to bodies of mafic or ultramafic rock, and the most convenient way in which to consider them is in terms of the type of magma responsible for the rocks with which they are associated. Typically the type of magma involved bears a close relationship to the tec- tonic setting within which it was emplaced. The locations of important deposits, both Ni-Cu dominant and PGE dominant, are shown in Fig. 1. 2. Considering first Ni-Cu deposits, these are further divided into six classes (Table 1. 2) on the basis of their associated magma type. Class NC- 1 (Chap. 3) comprises those related to komatiitic magmatism. Currently known deposits fall into two sub-classes, those related to Archean komatiites ( e. g. the deposits of Western Australia, Zimbabwe and the Abitibi belt of Canada) and those related to Proterozoic komatiites (e. g. those ofthe Raglau and Thompson belts which arebothin Canada)l.

The extraordinary growth of the computer and semiconductor industries and the increasing consumption of indium in these technologies in recent years have placed major constraints on current and future reserves of this metal. In the past, geoscientists have noticed the occurrence of indium in a large variety of ore de posits and detailed geochemical and mineralogical work is available for a few ex amples. However, despite the current technological interest, there is no compre hensive textbook that deals with all aspects of indium mineralization and economics. The present study attempts to develop a general metallogenic concept for indium in identifying the essential enrichment processes and their economic significance. The study 'Indium Geology, Mineralogy, and Economics' was commissioned and funded by the German Federal Institute for Geosciences and Natural Re sources (BGR Hannover) and is a contribution to the research program 'BGR 2000 - Raw Materials with Short Lifetime Reserves'. This program focuses on raw materials with known reserves confined to the next 20-25 years at static de mand. The future availability of reserves is usually estimated by dividing the known reserves by the current annual consumption. In fact, lifetimes of reserves are inappropriate measures because they depend on many parameters and there fore represent a "snapshot" of a dynamic system. In order to provide a sustainable use of raw materials with short lifetime reserves, a significantly higher amount of innovation is needed compared to raw materials with long lifetime reserves."

This book involves application of the Calphad method for derivation of a self consistent thermodynamic database for the geologically important system Mg0- Fe0-Fe203-Alz03-Si02 at pressures and temperatures of Earth's upper mantle and the transition zone of that mantle for Earth. The created thermodynamic database reproduces phase relations at 1 bar and at pressures up to 30 GPa. The minerals are modelled by compound energy formalism, which gives realistic descriptions of their Gibbs energy and takes into account crystal structure data. It incorporates a detailed review of diverse types of experimental data which are used to derive the thermodynamic database: phase equilibria, calorimetric stud ies, and thermoelastic property measurements. The book also contains tables of thermodynamic properties at 1 bar (enthalpy and Gibbs energy of formation from the elements, entropy, and heat capacity, and equation of state data at pressures from 1 bar to 30 GPa. Mixing parameters of solid solutions are also provided by the book. Table of Contents Introduction to the Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VII Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IX Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XI Co-Authors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XIII Vitae of Co-Authors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XV CODATA Task Group on Geothermodynamic Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XXIII Chapter 1. Thermodynamics and Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1. 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1. 2 Thermodynamic Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1. 3 Experimental Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. 4 Programs and Assessment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 System and Phases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1. 5 Chapter 2. Experimental Phase Equilibrium Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 The Si02 System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2. 1 2. 2 The Fe-0 System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2. 3 The Fe-Si-0 System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2. 4 The Mg0-Si0 System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

The significance of manganese ores is very weil known in cast iron and steel production, as weil as in various types of chemical raw material and agricultural fertilizers. The world industry development in recent years requires their increased production in the vicinity of the metallurgical centers in different regions of the world; high grade manganese and associated metalores are needed. Analysis of the world production and consumption of manganese ores by industrial countries indicates convincingly that the highest commercial value belongs to the ores associated with the supergene zone (National Minerals Advi- sory Board, 1981; Coffman and Palencia, 1984; Doncoisne, 1985; Iones, 1990, 1991; Manganese, 1990; McMichael, 1989). The remarkable property of manganese, in contrast to many other types of mineral resources, is that the ore accumulations of this metal are distributed in the wide geochrono- logical interval from the Archean to the present time; these ores are deposited in basins and supergene environments of different types from lakes, internal seas to pelagic and abyssal regions of the World ocean, as weIl as different types of weathering crusts and karst. At the same time the manganese accumulations and features of their mineral and chemical compositions are relatively sensitive indicators, reflecting facies and geodynamic condi- tions of their formation. These properties aid the investigation of the Earth's evolution processes.

This volume follows a Specialized Symposium on "Mantle denudation in slow spreading ridges and in ophiolites," held at the XII EUG Meeting in Strasbourg, spring 1993. During the meeting it was felt that the contribu tions to the Symposium justified a volume presenting its main scientific achievements. The present title of the volume shows that the center of inter est has slightly shifted with respect to the initial objective: in order to under stand the processes involved in accretion taking place at oceanic ridges, it is crucial to study the interaction between uppermost mantle and lower crust. The approach favored here is that of petrological and structural analysis of oceanic rocks in present-day oceanic ridges combined with similar studies in ophiolites. Rock specimen collected by submersibles or dredge hauls in oceanic ridge environments provide a "ground truth." However, except for areas such as the MARK (Mid-Atlantic Ridge ne ar Kane fracture zone) where, thanks to multiple submersible dives, the local geology is known with aprecision even better than in many onshore ophiolites, mutual rela tionships between uppermost mantle and lower crust are poorly known. In contrast, onshore ophiolites provide a necessary large-scale picture built up over many years of structural and petrological mapping."

Each gem deposit-whether of primary origin in the parent rocks; or secondary as alluvial placers in valley floors, river gravels, or the sand of oceanic shelves presents an eloquent chronicle of the Earth's life story. It reveals to the expert the prodigious processes which formed the present crust of our planet, of which this volume discloses a small but exciting detail. The materials of the Earth's crust are the rocks. In this book, the author expounds on how they were formed, why they altered, why they became the cradles of precious gemstones, how they are categorized, and how they are now exploited by man. What initiates the growth of gemstones? How do they crystallize? Why do gemstones of the same species, originating from different sources, vary? What causes the occurrence of varieties? Why do diamonds, unlike other precious stones, occur not near the Earth's surface in its crust, but deep down beneath it in the upper mantle? These are only a few of the entrancing subjects discussed in this enlightening volume. The reader learns that the Earth is surprisingly alive and altering constantly-sometimes through slow and equable changes and at times by violent and tremendous cataclysms, events from which gemstones issue.

This monograph was begun with two objectives in mind. The first was to provide a review of research involving the application of neodymium isotopic measurements to pro blems in earth science. In the process of organizing to do this, I realized that the research in this field had produced a need for an updated review of the underlying paradigms. This need had arisen because of the special properties of the samarium-neodymium isotopic system, and because the research had transgressed the traditional boundaries be tween the subfields of earth science. Without such a review, the significance of the results seemed likely to remain un necessarily obscure to interested scientists from related disciplines. Consequently, the second objective became the provision of a theoretical framework for the application of neodymium isotopic studies. Much of what this contains is not new, but it is drawn together here for the first time. At the time the writing was initiated, the literature of the field was still relatively limited. Over the past 5 years it has grown enormously. Considering the rate at which the writing progressed, it became clear that this could not be a fully up-to-date review and still reach completion. The selection of material for the review sections is biased toward earlier studies. Part I presents most of the background information."

The literature on the geology, chemistry, and biochemistry of phosphorus generally takes its mineralogy for granted. The in cidental information on phosphate minerals given in these texts is often obsolescent and inaccurate. The few mineralogical texts that have dealt comprehensively with the phosphate minerals have now become outdated, and typically present the essential information in a manner unsuitable for nongeological readers. This volume is intended as a ready reference for workers who require good basic information on phosphate minerals or their synthetic equivalents. The topics covered should appeal to geologists and geochemists, lithologists, environmental scientists and engineers, chemists and biochemists who have any interest in the intricate world of phosphorus. The hard tissues of many vertebrates and the many pathological calcifications consist mostly of phosphate minerals. The precipita tion of these compounds also plays a major role in the ecological cycling of phosphorus, and occasionally even dominates the behavior of many trace metals in many geochemical and biolog ical systems. Indeed, many pegmatitic phosphate minerals have acquired some notoriety because of the rarer trace metals which they tend to accumulate. With the commercialization of phosphate fertilizers since the early part of the 19th century, phosphate minerals have assumed an important role in industrial chemistry and agriculture. Clearly, the study of phosphate minerals is important from the economic, agricultural, environmental and (human and animal) health viewpoint."

This is the first book in English reviewing and updating the geology of the whole Apennines, one of the recent most uplifted mountains in the world. The Apennines are the place from which Steno (1669) first stated the principles of geology. The Apennines also represent amongst others, the finding/testing sites of processes and products like volcanic eruptions, earthquakes, olistostromes and melanges (argille scagliose), salinity crisis, geothermal fluids, thrust-top basins, and turbidites (first represented in a famous Leonardo's painting). As such, the Apennines are a testing and learning ground readily accessible and rich of any type of field data. A growing literature is available most of which is not published in widely available journals. The objective of the book is to provide a synthesis of current data and ideas on the Apennines, for the most part simply written and suitable for an international audience. However, sufficient details and in-depth analyses of the various complex settings have been presented to make this material useful to professional scholars and to students of senior university courses.

This multifaceted study explores new directions for plate tectonic research, especially as a guide for future geodynamic modelling of the earth. In particular, it equips readers with a plate-tectonic toolbox (with derivations and ANSI-C code) for applications and reconstruction analysis, including new continuous calculation methods. Pilger's Geokinematics shows how to apply these tools to Late Mesozoic and Cenozoic kinematics, with a focus on hotspot reference frames, and for empirical analysis of continental stress histories, including fractured hydrocarbon reservoirs. Supported by solid arguments and data, the book integrates theoretical developments of expanded plate kinematic theory and an ensemble of critical observations into a grand model, with the new concept of mesoplates playing a key role.

This book reviews the main energy sources, production problems and energy perspectives in Germany and Mexico. It surveys the status of traditional and alternative energy sources, including fossil fuels, nuclear, hydraulic, eolic, solar, and hydrogen cells. The book emphasizes the search for answers to such questions as What are the main problems of industries based on fossil fuels, and What is the present status of hydraulic and nuclear energy?

Microbial systems in extreme environments and in the deep biosphere may be analogous to potential life on other planetary bodies and hence may be used to investigate the possibilities of extraterrestrial life. This book examines the mode and nature of links between geological processes and microbial activities and their significance for the origin and evolution of life on the Earth and possibly on other planets. This is a truly interdisciplinary science with societal relevance.

Origin and Mineralogy of Clays, the first of two volumes, lays the groundwork for a thorough study of clays in the environment. The second volume will deal with environmental interaction. Going from soils to sediments to diagenesis and hydrothermal alteration, the book covers the whole spectrum of clays. The chapters on surface environments are of great relevance in regard to environmental problems in soils, rivers and lake-ocean situations, showing the greatest interaction between living species and the chemicals in their habitat. The book is of interest to scientists and students working on environmental issues.

This book is the proceedings of the 11th Kongsberg seminar, held at the Norwegian Mining Museum in the city of Kongsberg, about 70 km Southwest of Oslo. The Kongs berg district is known for numerous Permian vein deposits, rich in native silver. Mining activity in the area lasted for more than 300 years, finally ceasing in 1957. The first eight Kongsberg seminars, organized by professor Arne Bj0rlykke, now director of the Norwegian Geological Survey, were focused on ore-forming processes. These seminars have always been a meeting point for people with a variety of geological backgrounds. Since 1995, the Kongsberg seminars have focussed on geological processes, rather than on specific geological systems, and the selection of invited speakers has been strongly influenced by their interest in the dynamics of geological systems. In 1995 and 1996, various aspects of fluid flow and transport in rocks, were emphasized. The first "Kongsberg proceedings" (of the 1995 seminar) published by Chapman and Hall (Jamtveit and Yardley, 1997) contained 17 chapters dealing with a wide range of topics from field based studies of the effects of fluid flow in sedimentary and metamorphic rocks to computer simulations of flow in complex porous and fractured media. In 1997, the focus was changed to growth, and dissolution processes in geological systems."

Anisotropy, i.e., the dependence of structure and properties on direction in space, is the most striking characteristic of crystals. Anisotropy is a result of the discrete nature of the crystal lattice, and it is the characteristic which distinguishes the crystalline state from another solid state of matter, the amorphous. The anisotropy of the structure and properties of crystals (this can be called their 'internal anisotropy') is also reflected in their external structure, i.e., morphology. The reflection is, however, non-linear: properties such as mechanical hardness ... do not change strongly (typically several tens of percents, depending on direction) while the morphology ... : the linear sizes in different directions of individual crystals often differ by several multiples or even several orders of magnitude, depending on the symmetry of the crystalline lattice and/or of the crystal prehistory. The enhanced anisotropy of morphology is, as a rule, a result of growth kinetics of different crystalline faces; it reflects a non-linear character of the kinetic laws of growth. This book is devoted to high morphological anisotropy. No strict classification of highly-anisotropic crystals exists. However some typical forms, or habits, can be singled out: first, whiskers (or needles, or fibers) as quasi-one-dimensional crystals, and second, platelets as quasi-two-dimensional crystals.

Scientific research involving neutrons or synchrotron radiation is performed in large experimental installations at a few sites around the world. Taking full advantage of such techniques requires a wide range of specialized expertise not found in any university course. Therefore, there is a need for reference books and training courses to introduce young scientists to the underlying principles and methods.

Neutron and X-Ray Spectroscopy delivers an up-to-date account of the principles and practice of inelastic and spectroscopic methods available at neutron and synchrotron sources, including recent developments. The chapters are based on a course of lectures and practicals (the HERCULES course at the European Synchrotron Radiation Facility) delivered to young scientists who require these methods in their professional careers. Each chapter, written by a leading specialist in the field, introduces the basic concepts of the technique and provides an overview of recent work. This volume, which focuses on spectroscopic techniques in synchrotron radiation and inelastic neutron scattering, will be a primary source of information for physicists, chemists and materials scientists who wish to acquire a basic understanding of these techniques and to discover the possibilities offered by them. Emphasizing the complementarity of the neutron and X-ray methods, this tutorial will also be invaluable to scientists already working in neighboring fields who seek to extend their knowledge.

Granulites are, by definition, rocks that crystallized at high temperatures. It is generally agreed that they were formed in regions where the geothermal gradient exceeded normal continental values. These rocks commonly display coronitic mineral fabrics which may be used to trace the thermal and geodynamic history of the continental crust. In the same way that eclogites provide information on the earliest stages of some orogenic episodes, granulites usually tell us about later events, including thermal anomalies, thermal reequilibration, CO streaming, crustal melting, and 2 differentiation of the continental crust. Their study is particularly important if we are to under stand the nature of the middle and lower continental crust. Consistent with the contributions I received, the contents of this volume fall into four general areas: Crustal Evolution, Regional Syntheses, F1uids and Petrological Equilibria, Geochemistry and Geophysics. These represent an up-to-date reflection of the centres of interest in the field of granulites. The first manuscripts arrived in September 1988 while the conference was held, the last contribution arrived in November 1989, more than a year later. I apologize to those who were prompt and took deadlines seriously, but I believe that it was worth waiting to secure a product covering most of the important aspects concerning granulite genesis. All papers were vetted by at least two reviewers. I would like to thank RJ. Arculus, N.T. Arndt, P. Barbey, SR. Bohlen, AM. Boullier, M. Brown, T. Chacko, 1.D. Clemens, K.C. Condie, J.C. Duchesne, C. Dupuy, w.G."