Modern approaches to the theoretical computation and experimental determination of NMR shielding tensors are described in twenty-nine papers based on lectures presented at the NATO ARW. All of the most popular computational methods are reviewed and recent progress is described in their application to chemical, biochemical, geochemical and materials science problems. Experimental studies on NMR shieldings in gases, liquids and solids are also included, with special emphasis placed upon the relationship between NMR shielding and geometric structure and upon tests of the accuracy of the various computational methods. Qualitative MO schemes and semiempirical approaches are also considered in light of the computational results. This is a valuable book for anyone interested in how the NMR shielding tensor can be used to determine the geometric and electronic structures of molecules and solids. (abstract) Modern methods for computing and measuring nuclear magnetic resonance shielding tensors are described in papers by a great number of leaders in the field. The most popular methods for quantum mechanically calculating NMR shielding tensors are reviewed and many applications of these methods are described to problems in chemistry, biochemistry, geochemistry and materials science. The focus of the papers is on the relationship of the NMR shielding tensor to the geometric and electronic structure of molecules or solids.

As a method of structure analysis, electron diffraction has its own spe cial possibilities and advantages in comparison to the X -ray method for the study of finely dispersed minerals with layer or pseudolayer structures. How ever, possibly because of the prior existence of the X-ray method, which found universal application in different fields and attracted the main efforts of spe cialists, electron diffraction has been unevenly disseminated and developed in different countries. In particular, the oblique texture method, which gives very complete and detailed structural information, has been mainly used in the Soviet Union, where electron-diffraction cameras specially suited to the method have been constructed. In other countries, studies have been made of micro-single crystals, because these studies could be carried out with existing electron microscopes. It should be recognized that the scale of distribution and use attained by electron-diffraction methods, at present limited by exist ing experimental conditions. is more than justified by the value of the results which may be obtained by their aid. The author hopes that the present book will give the reader a fuller idea of the valuable advantages of the method, and of the structural crystallography picture which has been built up for clay minerals, and layer silicates in general, from electron-diffraction data. The time between the appearance of this book and that of the Russian edition has been comparatively short."

Volcanic eruptions are fascinating manifestations of the Earth's dynamic inte rior which has been cooling for the past several billion years. The planets of the solar system originated some 4.5 billion years ago from the same gas and dust cloud created by the big bang. Some of the gas collapsed by the gravitational force to form the Sun at the center, while the whirling disk of gas and dust around the Sun subsequently cooled and lumped together to form larger and larger lumps of materials or planetesimals. These planetesimals collided fre quently and violently and in the process liberated heat that melted the material in them. With time this material gradually cooled and formed the planets of the solar system. During the second half of the twentieth century the theory of plate tectonics of the Earth became established and demonstrated that our planet is covered with six large and many small plates of the lithosphere. These plates move over a highly viscous lower part of the Earth's upper mantle and contain the continental and oceanic crusts. The lower mantle extends below the upper mantle until it meets the core that is more than half the diameter of the entire globe (12,740 km). The inner core consists mostly of iron and its temperature is about 5000 kelvin, whereas the liquid outer core is turbulent, rotates faster than the mantle, consists primarily of iron, and is the source of the Earth's magnetic field."

of a Roman numeral, an alphabetic character and an Arabic numeral. This designation constitutes the classification symbol based on the system in Mineralogische Tabellen by Hugo Strunz (a summary is shown in Appendix A). The Roman numeral and alphabetical character divide the minerals into broad groups based mainly on chemistry, with the silicate subdivision based on silicate polymerization. The Arabic numeral specifies the group to which a particular mineral belongs; a group is defined mainly on the basis of crystallographic similarities, but minerals with similar chemical compositions are sometimes included in the group even though they do not exhibit crystallographic affinities with other members of the class. The next entry gives the name of the author of the mineral and the date of its introduction into the literature. In some cases where a mineral has been redescribed or the name has been changed from the original, this entry will reflect the person and time when this was done. This is followed by a reference to what we have tried to make the latest, or most authoritative, literature report. We have attempted to include at least one reference for each species. If there is a second reference following the first, it will be a reference to the determination of the crystal structure. The abbreviations used in the references are given in Appendix B. The final entry, when present, gives the names of similar or related minerals and is preceded by the deSignation "See also" .

Due to its inherent characteristics, mercury contamination from gold mining is a major environmental problem compared to past mercury contamination from industrial point sources. The worsening of social-economical conditions and increasing gold prices in the late 1970s resulted in a new rush for gold by individual entrepreneurs for whom Hg amalgamation is a cheap and easily carried out operation. Even after the present-day mining areas are exhausted, the mercury left behind will remain part of the biochemical cycle of the tropical forest. This book reviews the current information on mercury from gold mining, its cycling in the environment and its long-term ecotoxicological impact. The book is illustrated with numerous diagrams and photographs.

This book gives an account of a method of determining the type composition of sandy deposits from the air by the nature of their reflection of radiant energy. The measured spectral luminance of a rock outcrop rela ti ve to the luminance of a standard is the basic property considered in this method. The spectral luminance factors p\ are measured by means of special instruments - a universal photometer, cinespectrograph, spectro visors, and other spectrometers. The measured values of P" of the investigated rocks are interpreted geologically with the aid of some methods of mathematical statistics so that a means of lithological mapping of sandy deposits from the air can be found. The importance of developing a method of determining the type composition of rocks, primarily sandy de posits, from the air stems from the extensive occurrence of deserts on the earth's surface. Sandy deserts occupy vast areas in the southern latitudes of the USSR and occur in western and central China, Pakistan, Iran, India, and other states. In these deserts there are numerous deposits of petroleum and gas, and a search for water is continuously in progress. Successful prospecting for the above minerals depends on a determination of the material composition of the sandy deposits in these deserts and the solution of several questions of recent tec tonics, paleogeography, and quaternary geology, the answers to which might also be given by a study of the dis tribution of lithological types of sands.

This book introduces the concept of crystallographic non- rigidity and asymmetry of the transition elements as central atoms organometallic compounds. This intrinsic behavior of central atoms in condensed matter is quantified by applying statistical approach. Averaging of extrinsic factors in crystal structures is tested by using variance analysis. Introductionof the above mentioned concept and applications of variance analysis as an approximation for considering factors influencing properties of central atomin the crystal is original and new.

Modeling and simulation were introduced to the earth sciences about four decades ago. Modeling has proven its worth and now it is an accepted procedure for analyzing and solving geological problems. The papers in this collection are focused on modeling sediment deposition and sedimentary sequences and have a decidedly practical flavor. Some of the leading simulation packages, such as CORRELATOR, SEDFLUX, SEDpak, SEDSIM, STRATA, and STRATSIM are applied to problems in hydrocarbon exploration, oil production, groundwater development, coal-bed appraisal, geothermics, and environmental diagnosis. All of these subjects fall under the broad heading of sedimentary basin analysis. The fifteen papers in this volume are written by internationally recognized experts from academia and industry. The contributions represent the status of geologic modeling and simulation at the start of the 21st century, and will give the reader an insight into current research problems and their possible solutions.

Microbial defacement and degradation of artistic or historic artifacts is a worldwide problem affecting all countries regardless of their history, geographical location, or economic conditions. This is the first comprehensive study of the role of microbial colonization on the degradation of different cultural artifacts (from buildings to books, wall paintings, textiles, sculptures and glass) and of the investigations into the compounds utilized to control microbial invasion. The book focuses on three main areas: the identification of the microorganisms which cause structural damage; methods to reduce or prevent microbial colonization and damage; and the use of microorganisms for the protection and bioremediation of cultural artifacts.

Basalt is the most voluminous of all the igneous rocks. Extensive field, experimental, petrographic and geochemical studies of basalt have provided us with a considerable understanding of igneous petrogenesis, plate tectonics, and crust-mantle interaction and exchange. One important aspect of geology that has developed over the last few decades is the study of oceanic basalts. The ocean basins cover about two thirds of the earth's surface and are floored by a basement of oceanic basalt that is continuously undergoing generation at spreading centres and destruction at subduction zones, a process which throughout geological time is recognized as the principal means of generating new crust. The study of oceanic basalts enables us to understand better the generation and recycling of crustal materials (including the continental crust), and the exchange between oceanic crust and seawater via hydrothermal activity. Compositional variations displayed by oceanic basalts provide windows into the mantle, and the identification of isotopically-distinct mantle reservoirs demonstrates that the source of oceanic basalts is heterogeneous and is controlled by convection and reservoir interactions within the mantle.

Partial melting occurs in a variety of geological environments, from granitic partial melts in the continental crust, to basaltic or carbonate partial melts in the upper mantle. Partial melting is the first stage of magmatism and therefore plays a role of primary importance in the chemical differentiation of the Earth and in the transport of heat to the Earth surface. This special volume contains contributions presented at the symposium `Physics and Chemistry of Partially Molten Systems' of the EUG 9 meeting, held in Strasbourg, France, on March 23-27, 1997. It is intended to provide a current understanding of the physics of partial melting and melt segregation and covers topics such as the rheology of partially molten systems, the topology of partial melts, modelling of partial melting processes, and field observations of partial melts. Audience: This book is intended for a broad readership, including graduate students, specializing in petrology and geodynamics. The volume may be recommended as a textbook for graduate courses on petrology, geomaterial sciences and geophysics.

This volume illustrates some of the significant aspects of magmatic activity from Devonian (408 million years ago) to early Permian (270 million years ago) times in SW England. This period covers the progressive development of the Variscan mountain-building episode, from initial basin formation to final deformation and the subsequent development of a fold mountain belt - the Variscan Orogen. Both extrusive (volcanic) and intrusive (plutonic) rocks are found in the orogen, and chart the various stages of its magmatic development. The sites described in this volume are key localities selected for conservation because they are representative of the magmatic history of the orogen from initiation to stabilization. Some of the earliest volcanic activity in the Devonian is represented by submarine basaltic and rhyolitic lavas developed in subsiding basins, caused by the attenuation of the existing continental crust. In some cases, extensive rifting and attendant magmatism produced narrow zones of true oceanic crust, whereas elsewhere basaltic volcanism is related to fractures in the continental crust at the margins of the basins. After the filling of the sedimentary basins, and their deformation caused by crustal shortening (late Carboniferous Period), further activity is manifested by the emplacement of the Cornubian granites and later minor basaltic volcanism in the early Permian. Accounts of the constituent parts of this history have enriched geological literature from the nineteenth century onwards, and have contributed to the advancement and understanding of magmatic and tectonic processes.

A knowledge of clay is important in many spheres of scientific endeav our, particularly in natural sciences such as geology, mineralogy and soil science, but also in more applied areas like environmental and mater ials science. Over the last two decades research into clay mineralogy has been strongly influenced by the development and application of a num ber of spectroscopic techniques which are now able to yield information about clay materials at a level of detail that previously would have seemed inconceivable. This information relates not only to the precise characterization of the individual clay components themselves, but also to the ways in which these components interact with a whole range of absorbate molecules. At present, however, the fruits of this research are to be found principally in a somewhat widely dispersed form in the scientific journals, and it was thus considered to be an appropriate time to bring together a compilation of these spectroscopic techniques in a way which would make them more accessible to the non-specialist. This is the primary aim of this book. The authors of the various chapters first describe the principles and instrumentation of the individual spectro scopic techniques, assuming a minimum of prior knowledge, and then go on to show how these methods have been usefully applied to clay mineralogy in its broadest context."

The chemical interaction of water and rock is one of the most fascinating an d multifaceted process in geology. The composition of surface water and groundwater is largely controlled by the reaction of water with rocks and minerals. At elevated temperature, hydrothermal features, hydrothermal 0 re deposits and geothermal fields are associated with chemical effects of water-rock interaction. Surface outcrops of rocks from deeper levels in the crust, including exposures of lower crustal and mantle rocks, often display structures that formed by interaction of the rocks with a supercritical aqueous fluid at very high pT conditions. Understanding water-rock interaction is also of great importance to applied geology and geochemistry, particularly in areas such as geothermal energy, nuclear waste repositories and applied hydrogeology. The extremely wide-ranging research efforts on the universal water-rock interaction process is reflected in the wide diversity of themes presented at the regular International Symposia on Water-Rock Interaction (WRI). Because of the large and widespread interest in water-rock interaction, the European Union of Geosciences organized a special symposium on "water-rock interaction" at EUGI0, the biannual meeting in Strasbourg 1999 convened by the editors of this volume. In contrast to the regular WRI symposia addressed to the specialists, the EUG 10 "water-rock interaction" symposium brought the subject to a general platform This very successful symposium showed the way to the future of water-rock reaction research.

Many people have contributed to the production of this book, and I wish to acknowledge the following colleagues who have, over the past 15 years, contributed much discussion, preprints, thin sections, rock samples, and unpublished and/or difficult-to- obtain information: Steve Bergman, Roger Clement, Howard Coopersmith, Barry Dawson, Alan Edgar, Tony Erlank, Steve Haggerty, Barry Hawthorne, Bram Janse, Viktoria Komilova, Sergei Kostrovitskii, Henry Meyer, Peter Nixon, Nick Rock, Mike Skinner, Patricia Sheahan, Simon Shee, Barbara Scott Smith, Andy Spriggs, Ken Tainton, Larry Taylor, Nikolai Vladykin, Allan Woolley, and Peter Wyllie. Special thanks go to Henry Meyer, for providing many hours of microprobe time at Purdue University, and to Mike Skinner, for samples and the opportunity to examine the Anglo-American Research Laboratory collection of orangeites. Particular thanks are expressed to Ken Tainton for permission to quote data from his Ph.D. thesis. Particular gratitude is expressed to Sam Spivak for drafting and photographic work and to Anne Hammond for preparing many polished thin sections of these difficult rocks. Their dedication, skills, and attention to detail are greatly appreciated by the author. Others from Lakehead University who helped materially during the production of this work include Reino Viitala (thin sections), Alan MacKenzie (electron microscopy), and Shelley Moogk-Pickard (trace element analysis). Carl Hager is thanked for assistance in using the Purdue microprobe.

This is the first book to deal specifically with the procedures used in the analysis of structural relationships and the determination of structural successions in complexly deformed rocks such as migmatites and gneisses. The establishment of structural successions enables: The rigorous control of the dating of specific events in the deformational history by constraining the sites of the dated rocks within the structural succession; The establishment of the time span of orogenic events throughout the structural succession, and the rate of orogenic processes;Their comparison to be used as a basis for correlation between dismembered and separated crustal segments in continental reconstructions;The resolution of the complex relationships between deformed ore bodies and host rocks in high grade terranes, and hence determination of the structural control of ore bodies, an essential part of any successful geological exploration, and a precondition to efficient exploitation. With its new approach, and the use of practical field examples from various parts of the world, this highly illustrated work will form an invaluable reference resource for postgraduates, lecturers and researchers in the structural and isotope geology of high-grade metamorphic terranes, as well as for exploration and survey geologists working in the field. Dr Alaric M. Hopgood who holds an Honorary Readership at the University of St Andrews, Scotland, was a Reader in the Department of Geology there until 1995.

Zeolites, with their crystalline microporous structures, are cordial hosts to a wide variety of guests. However, it was the abrupt and unexpected departure of one of these guests (water) from a host (stilbite) on heating which led Cronstedt, in 1756, to coin the term "zeolite" (from the Greek meaning "boiling stone") to describe this material. Since that time, approximately 40 different naturally-occurring zeolites have been discovered on earth. Recent studies of meteorite compositions have shown that these guest-host materials (e. g. , sodalite) occur in other parts of the universe as well. However, it wasn't until the twentieth century that synthetic routes to zeolites and other non-aluminosilicate molecular sieves were discovered. In addition, with the development of X-ray diffraction and the various spectroscopies, better understanding of the nature of the cavities, cages, and channels of these materials has led to the industrial exploitation of their guest-host properties. The world of zeolites has now expanded into a greater than 2 billion pound per year business, with major applications in detergent formulations, catalysis, and as adsorbents and desiccants. Their economic impact is difficult to determine; however, the improvement in gasoline yields alone (from catalytic cracking) must account for hundreds ofbillions ofdollars in increased GDP. In this volume, we have brought together a sampling of recent developments in various areas of guest-host or inclusion chemistry in zeolites.

The workshop "From Dust to Terrestrial Planets" was initiated by a working group of planetary scientists invited to ISSI by Johannes Geiss in November 1997. The group split to focus on three topics, one of which was the history of the early solar system, including the formation of the terrestrial planets in the inner solar system. Willy Benz, Gunter Lugmair, and Frank Podosek were invited to convene planetary scientists, astrophysicists, and cosmochemists to synthesize the current knowledge on the origin and evolution of our inner planetary system. The convenors raised the interest of scientists from all over the world in the detailed assessment of the available astronomical, chronological, geochemical and dynamical constraints of the first period of inner solar system evolution. In partic ular, this included appraisal of the newest results from astronomical observations by the Hubble Space Telescope, the Infrared Space Observatory, and other space and ground-based facilities of solar-like systems and nebular disks, possibly repre senting early stages of the solar accretion disk and planet formation. At the same time, the current models of the origin, evolution, transport, and accretion processes of circum stellar disks were presented. This included the new insights provided by the recent discovery of extrasolar giant planets, which were considered insofar as they are relevant to the overall dynamics of the inner part of the solar system.

In this book, the first dedicated entirely to the petrology of lamproites and their relationships to other potassium-rich rocks, the objective of the authors is to provide a comprehensive critical review of the occurrence, mineralogy, geochemistry, and petrogenesis of the clan. Although lamproites represent one of the rarest of all rock types, they are both economically and scientifically important and we believe the time is ripe for a review of the advances made in their petrology over the past two decades. Many of these advances stem from the recognition of diamond-bearing lamproites in Western Australia and the reclassification of several anomalous diamond-bearing kim berlites as lamproites. Consequently lamproites, previously of interest only to a small number of mineralogists specializing in exotica outside the mainstream of igneous petrol ogy, have become prime targets for diamond exploration on a worldwide basis. Contemporaneously with these developments, petrologists realized that lamproites possess isotopic signatures complementary to those of midoceanic ridge basalts, alkali basalts, kimberlites, and other mantle-derived melts. These isotopic studies provided new insights into the long-term development of the mantle by suggesting that the source regions of lamproites were metasomatically enriched in light rare earth and other incompatible elements up to 1-2 Ga prior to the melting events leading to generation of the magma.

For much of the 20th century, scientific contacts between the Soviet Union and western countries were few and far between, and often super ficial. In earth sciences, ideas and data were slow to cross the Iron Curtain, and there was considerable mutual mistrust of diverging scient ific philosophies. In geochemistry, most western scientists were slow to appreciate the advances being made in the Soviet Union by os. Korz hinskii, who put the study of ore genesis on a rigorous thermodynamic basis as early as the 1930s. Korzhinskii appreciated that the most fun damental requirement for the application of quantitative models is data on mineral and fluid behaviour at the elevated pressures and temper atures that occur in the Earth's crust. He began the work at the Institute of Experimental Mineralogy (IEM) in 1965, and it became a separate establishment of the Academy of Sciences in Chernogolovka in 1969. The aim was to initiate a major programme of high P-T experimental studies to apply physical chemistry and thermodynamics to resolving geological problems. For many years, Chernogolovka was a closed city, and western scient ists were unable to visit the laboratories, but with the advent of peres troika in 1989, the first groups of visitors were eagerly welcomed to the IEM. What they found was an experimental facility on a massive scale, with 300 staff, including 80 researchers and most of the rest pro viding technical support."

Globally, forest vegetation and soils are both major stores of terrestrial organic carbon, and major contributors to the annual cycling of carbon between the atmosphere and the biosphere. Forests are also a renewable resource, vital to the everyday existence of millions of people, since they provide food, shelter, fuel, raw materials and many other benefits. The combined effects of an expanding global population and increasing consumption of resources, however, may be seriously endangering both the extent and future sustainability of the world's forests. About thirty chapters cover four main themes: the role of forests in the global carbon cycle; effects of past, present and future changes in forest land use; the role of forest management, products and biomass on carbon cycling, and socio-economic impacts.

There has long been interest in the flow of fluids through permeable aqui fers. Stratigraphic trapping of oil and gas by permeability changes in an aquifer and the amounts of hydrocarbons so trapped are major concerns to the oil industry. The variations of aquifer width and geometry and of the positions in an aquifer where hydrocarbons can be trapped by hydro dynamic forces are intimately intertwined in determining the shape, and thus the volume, of hydrocarbons. Perhaps the seminal work in this area is reflected by King Hubbert's massive review paper "Entrapment of Petroleum under Hydrodynamic Conditions" (Am. Assoc. Pet. Geol. Bull. 37(8), 1954-2026, 1953), in which a wide variety of effects, such as capillarity, buoyancy, surface tension, and salinity of water, are incorporated as basic factors influenc ing the positioning and shaping of hydrocarbon masses in hydrodynami cally active aquifers. In those days, while the basic physics could readily be appreciated, development of a detailed quantitative understanding of the interplay of the various factors in controlling or modulating hydro dynamic shapes was severely limited by computer abilities. Indeed, Hub bert actually constructed and photographed physical models, using alcohol and water, to illustrate basic concepts. It is difficult to obtain an appreciation of the behavior of flow geometries from such experiments when all factors are permitted to vary simultaneously.

Results of selected projects on Exploration R & D, one of the major research areas implemented by the Commission of European Communities in Brussels on the subject of mineral raw materials, are presented on an international basis. All aspects of the geology and geochemistry of ore deposits and their host rocks are covered. Main headings are according to commodity, i.e. tungsten, chromite, and base metals, rather than by scientific criteria. The scope and subject matter varies from the metallogenic province to the individual deposit. The question of possible application to exploration methodology is explored in several papers. Particularly structural and geochemical techniques are discussed.

This second volume in the new series produced by the Mineralogical Society is concerned with the study of rocks from the deep continental crust. It is, we hope, timely to summarize recent petrological advances contributing to this field of active interest. Based mainly on review papers read at a conference, the chapters have subsequently been revised and expanded, while the editors have produced an introductory overview as Chapter 1. The conference was the Winter Meeting of the Mineralogical Society on 15 December 1988, at wh ich Prof. R. C. Newton delivered the 20th Hallimond Lecture of the Society (which forms the basis of Ch. 7). The editors are grateful to all who contrib uted to the smooth running of the meeting at Kingston Polytechnic, and in the ensuing preparation of the volume: in particular, we sincerely thank all of the following for their labours as referees: A. J. Baker, L. M. Barron, M. J. Bickle, A. D. Chambers, J. D. Clemens, J. S. Daly, G. T. R. Droop, C. R. L. Friend, E. S. Grew, S. L. Harley, R. S. Harmon, N. B. W. Harris, B. Harte, T. J. B. Holland, N. F. C. Hudson, W. S. MacKenzie, W. Perkins, H. R. Rollinson, J. W. Sheraton, D. J. Waters, R. H. Worden and B. W. D. Yardley. John R.

Locked up within human bone are tantalizing clues concerning the diets consumed by ancient peoples. On the one hand the amounts of certain elementsin bone (strontium, zinc) serve as measures of protein, fiber, and calcium intake. On the other hand, the ratios of carbon isotopes and of nitrogen isotopes provide information on questions of fish vs. meat, herbivore vs. carnivore, or (for animals) browser (shrubs) vs. grazer (grasses). Such information can provide a window on many aspects of prehistoric cultures and can supplement the nonskeletal archaeological record. In addition to these two approaches, the biochemical record in bone from protein and nucleic acids such as DNA serves as a source of nondietary information such as genetic relationships. This volume treats all three subjects.: elemental, isotopic, and biochemical. The foremost experts in the areas provide fundamental descriptions of the techniques, express their concerns over the limitations of the methods, and describe recent applications to archaeological studies.