This book presents the third volume of a complete development of the new structural classification of minerals, which is based on the internal crystal structure, and is therefore its natural classification. Because of the large domain of the mineral kingdom, this work is divided in three volumes, in which the minerals are ordered from the structurally simple to the more complex.

Audience: This work will be of particular interest to teachers and research workers of in mineralogy, and in inorganic crystal structures in academia.

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.

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.

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.

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.

The origin of granite has for long fascinated geologists though serious debate on the topic may be said to date from a famous meeting of the Geological Society of France in 1847. My own introduction to the subject began exactly one hundred years later when, in an interview with Profes sor H. H. Read, I entered his study as an amateur fossil collector and left it as a committed granite petrologist - after just ten minutes I can hardly aspire to convert my reader in so dramatic a way, yet this book is an attempt, however inadequate, to pass on the enthusiasm that I inherited, and which has been reinforced by innumerable discussions on the outcrop with granitologists of many nationalities and of many shades of opinion. Since the 1960s, interest in granites has been greatly stimulated by the thesis that granites image their source rocks in the inaccessible deep crust, and that their diversity is the result of varying global tectonic context. So great a body of new data and new ideas has accumulated that my attempt to review the whole field of granite studies must carry with it a possible charge of arrogance, especially as I have adopted the teaching device of presenting the material from a personal point of view with its thinly disguised prejudices."

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.

The second volume of this series consists of three parts. Part I focuses on the research on intracrystalline reactions. This work, which began nearly two decades ago, is critically reviewed by Ghose and Ganguly in Chapter 1. Besides the review, the authors include some of their previously unpublished work to demonstrate how future research could aid in obtaining data on thermodynamics of solid solutions and in understanding the cooling history of igneous and metamorphic rocks. The latter is also the theme adopted by Kretz in the second chapter, which examines the redistribution of Fe and Mg in coexisting silicates during cooling. Chapter 3 contains new data on Fe-Mg distribution in clinopyroxenes. Dal Negro and his co-authors have selected a series of clinopyroxenes from volcanic rocks and present site occupancy data on several clinopyroxenes of intermediate compositions. The data set has not been published before and is the first of its kind. Part II of this book begins with a chapter on melts by Gaskell, who explores the relationship between density and structure of silicate melts. This is followed by the synthesis of data generated in the U.S.S.R. by Shmulovich and his co-authors on fluids. Blencoe, Merkel and Seil present a thorough analysis of the phase equilibrium data on feldspars coexisting with fluids in the third chapter in this part.

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.

The research on mineral deposits and the exploration of new vast resources made exceptional progress worldwide during the last decades. At the same time, mining activity has shifted from the historical European centres to other continents. Even though the mineral pro- duction of the Alpine province has lost its significance as compared with other areas of the world in this century, striking ideas and theo- ries on the formation of mineral deposits originating from this domain have stimulated lively international discussion. This may be explained by the proximity of different peoples with varying geographical and intellectual backgrounds meeting in the Alpine region. Realizing this development some Italian colleagues, above all Remo Albertini and Guiliano Perna, initiated the (first) International Sym- posium on Mineral Deposits of the Alps in 1966. When I. ISMIDA won favorable attention, it was resolved to call further meetings at regular intervals. A different Alpine country was host and organizer each time. As a first summary of the historical development, we give a short record of previous meetings: I. ISMIDA Sept. 11-18,1966, held at Passo della Mendola/Italy II. ISM IDA Oct. 4-6, 1971,heldatBled/Yugoslavia III. ISMIDA Oct. 3-7, 1977, held at Leoben/ Austria IV. ISMIDA Oct. 5-10,1981, held at Berchtesgaden/Bavaria, FRG The present volume contains the greater number of papers pre- sented at the Fourth International Symposium on Mineral Deposits of the Alps, held at Berchtesgaden (Bavaria), Federal Republic of Ger- many, in 1981.

Solid-solution equilibria of marine evaporites are important in a wide range of science and technology. However, the data had not yet been summarized in a form that is at the same time comprehensive and permits to understand how the quinary seawater system builds up from its bounding systems. Thus the goal of the present volume is at the same time scientific and educational. The understanding of solid-solution equilibria of the various systems with respect to dissolution, precipitation and transformation of solids, their application to the evolution of brines, and a fast access to data is a necessary requirement for any modelling, especially in Geoscience. Another goal is to show the avail ability of data. Unfortunately, though solubility data are numereous there are substantial gaps, especially with respect to high temperatures. But also up to about 100 0 C data are missing for some of the systems so that they cannot be described entirely. Based on the present volume further work on the solubili ties of the minerals of marine evaporites may be promoted. The data have been viewed and collected over several years by the first author. The second author entered the preparation of the volume when it was realized that besides graphics and tables a fast access to data was required. Although both authors are responsible for the whole volume, responsibility is weighted somewhat differently for the various parts."

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.

ACKNOWLEDGMENTS xiii 1 THE HISTORY AND ROMANCE OF THE GLYPTIC ARTS THE EARLIEST ENGRAVINGS 3 CLASSICAL GREECE: FROM SCARABOID TO CAMEO 6 ROMAN CAMEOS 11 THE DARK AND MIDDLE AGES 19 THE RENAISSANCE AND LATER 23 2 THE SUBJECTS: MYTHS, LEGENDS, HISTORICAL EVENTS, AND STORIES BEHIND THE)EWELS MYTHS AND LEGENDS 33 SYMBOLS 42 vii PORTRAITS 44 HISTORICAL EVENTS AND STORIES BEHIND THE ]EWELS 45 3 CAMEO PRODUCTION TOOLS AND TECHNIQUES 50 MATERIALS 60 CARVING CENTERS AND RENOWNED CARVERS 80 4 DISTINGUISHING uLD AND NEWCAMEOS CIRCA-DATING CAMEOS 92 DETECTING CAMEO FAKES, FRAUDS, AND FORGERIES 113 5 MODIFIED CAMEOS AND CAMEO IMITATORS GLASS CAMEOS 127 CAMEO GLASS 129 TASSIE GLASS 131 WEDGWOOD 132 SULPHIDES 135 CONTENTS viii PLASTIC CAMEOS 135 CAMEO W AX PORTRAITS 136 PLASTER OF PARIS AND SULPHUR CASTS 138 6 ApPRECIATING CAMEOS AS ART ELEMENTS OF V ALUE 149 7 BUILDINGA CAMEO COLLECTION BUYING AND SELLING CAMEOS 162 CAMEOS AS INVESTMENT GEMS 169 CARE AND CONSERVATION OF CAMEOS 170 8 GREAT AND HISTORIC COLLECTIONS 175 ApPENDIX 193 Auctions 193 Glyptic-Arts Booksellers 194 CONTENTS ix Appraisal Associations 194 Retail Sources for Cameos in the Uni ted States 194 CHRONOLOGY OF ENGRAVED STONES AND CAMEOS IN EUROPE 196 GLOSSARY OF GLypTIc-ART AND ]EWELRY TERMS 199 SUGGESTED READINGS AND BIBLIOGRAPHY 205 INDEX 210 CONTENTS x p r e a c e f In several years of studying the cameo and its development, I have interviewed connoisseurs and collectors throughout the United States,

Marine Clastic reservoirs provides an integrated perspective to sandstone reservoir description and analysis. It combines analog-oriented methods fromsequence stratigraphy with rigorous stratigraphic and sedimentological description of cores and outcrops to develop a process-based analysis of sandstone facies. Twelve chapters, divided into 3 sections, first describe the specific use of sequence stratigraphy to catalog, identify, andpredict marine clastic reservoir facies. Next they examine the importance ofrigorous sedimentological and geomorphic description. Finally, marine depositional environments from delta systems to deep-sea fans arereviewed to give examples of these improved descriptive and analytical techniques

l J. Parnell It is widely documented that concentrations of metal may be associated with diverse organic materials, from living plants and animals through organic-rich sediments to crude oil, solid bitumen/pyrobitumen, and graphite. The signifi- cance of organic matter in mineralizing processes has been the subject of several special publications, including the proceedings of symposia on Oil and Ore (Garrard 1977), Organics in Ore Deposits (Dean 1986), the Role of Organisms and Organic Matter in Ore Deposition (MacQueen 1985), and Organic Matter in Hydrothermal Systems (Simoneit 1990). Recent research has made notable advances in the use of organic geochemical/pyrolysis data to assess the thermal maturity of ore deposits (e. g. , MacQueen and Powell 1983), the transport of metals in fluids which contain organic compounds (e. g. , Manning 1986), the role of microbiota in fixing metals (e. g. , Morton and Changkakoti 1987) and the nature of sulphate reduction in sulphide ores associated with hydrocarbons (e. g. , Leventhal 1990). The roles of fluid hydro- carbons in ore metal transport and solid hydrocarbons (bitumens) in ore metal deposition have been reviewed by Manning (1986) and Parnell (1988) respectively. This Volume places emphasis on bitumens; either bitumens which occur in ore deposits, or are enriched in or otherwise associated with metals. Inevitably some accounts describe cases where metals are associated with both bitumens and autochthonous organic matter (kerogen).

This volume contains a selection of papers presented to the Fourth International Symposium on Environmental Biogeochemistry (ISEB), and a conference on Biogeochemistry in Relation to Mining Industry and Environmental Pollution (Leaching Conferenc, held in Canberra, Aust ralia on August 26-31 and September 3-4, 1979, respectively. The ISEB were established to provide "a forum for uninhibited exchange of information and ideas among the biological, chemical, atmospheric and geolopical scientists working in the common area of biogeochemistry, encompassing soil and other earth sciences as weIL as the hydrosphere and atmosphere," By linking the fourth ISEB with the Leachinp Conference the scop.e of discussions was extended to encompass the application of biogeochemical processes to the mining industry. This wide-ranging philosophy is reflected in the breadth and diversity of the subjects covered in this book. The published papers are expanded versions of those presented at the meetings. They have all been scrutinized by at least one referee in addition to the editors. About 20% of the contributions to the meetings are not included, either because authors did not wish to publish or because the papers were not accepted by the editors."