ALBERT

Description / Table of Contents: Exactly 100 years before the publication of this volume, the first paper which calculated the half-life for the newly discovered radioactive substance U-X (now called 234Th), was published. Now, in this volume, the editors Bernard Bourdon, Gideon Henderson, Craig Lundstrom and Simon Turner have integrated a group of contributors who update our knowledge of U-series geochemistry, offer an opportunity for non-specialists to understand its basic principles, and give us a view of the future of this active field of research. In this volume, for the first time, all the methods for determining the uranium and thorium decay chain nuclides in Earth materials are discussed. It was prepared in advance of a two-day short course (April 3-4, 2003) on U-series geochemistry, jointly sponsored by GS and MSA and presented in Paris, France prior to the joint EGS/AGU/EUG meeting in Nice. The discovery of the 238U decay chain, of course, started with the seminal work of Marie Curie in identifying and separating 226Ra. Through the work of the Curies and others, all the members of the 238U decay chain were identified. An important milestone for geochronometrists was the discovery of 230Th (called Ionium) by Bertram Boltwood, the Yale scientist who also made the first age determinations on minerals using the U-Pb dating method (Boltwood in 1906 established the antiquity of rocks and even identified a mineral from Sri Lanka-then Ceylon as having an age of 2.1 billion years!) The application of the 238U decay chain to the dating of deep sea sediments was by Piggott and Urry in 1942 using the "Ionium" method of dating. Actually they measured 222Ra (itself through 222Rn) assuming secular equilibrium had been established between 230Th and 226Ra. Although 230Th was measured in deep sea sediments by Picciotto and Gilvain in 1954 using photographic emulsions, it was not until alpha spectrometry was developed in the late 1950's that 20Th was routinely measured in marine deposits. Alpha spectrometry and gamma spectrometry became the work horses for the study of the uranium and thorium decay chains in a variety of Earth materials. These ranged from 222Rn and its daughters in the atmosphere, to the uranium decay chain nuclides in the oceanic water column, and volcanic rocks and many other systems in which either chronometry or element partitioning, were explored. Much of what we learned about the 238U, 235U and 232Th decay chain nuclides as chronometers and process indicators we owe to these seminal studies based on the measurement of radioactivity. The discovery that mass spectrometry would soon usurp many of the tasks performed by radioactive counting was in itself serendipitous. It came about because a fundamental issue in cosmochemistry was at stake. Although variation in 235U/238U had been reported for meteorites the results were easily discredited as due to analytical difficulties. One set of results, however, was published by a credible laboratory long involved in quality measurements of high mass isotopes such as the lead isotopes. The purported discovery of 235U/238U variations in meteorites, if true, would have consequences in defining the early history of the formation of the elements and the development of inhomogeneity of uranium isotopes in the accumulation of the protoplanetary materials of the Solar System. Clearly the result was too important to escape the scrutiny of falsification implicit in the way we do science. The Lunatic Asylum at Caltech under the leadership of Jerry Wasserburg took on that task. Jerry Wasserburg and Jim Chen clearly established the constancy and Earth-likeness of 235U/238U in the samplable universe. In the hands of another member of the Lunatic Asylum, Larry Edwards, the methodology was transformed into a tool for the study of the 238U decay chain in marine systems. Thus the mass spectrometric techniques developed provided an approach to measuring the U and Th isotopes in geological materials as well as cosmic materials with the same refinement and accommodation for small sample size. Soon after this discovery the harnessing of the technique to the measurement of all the U isotopes and all the Th isotopes with great precision immediately opened up the entire field of uranium and thorium decay chain studies. This area of study was formerly the poaching ground for radioactive measurements alone but now became part of the wonderful world of mass spectrometric measurements. (The same transformation took place for radiocarbon from the various radioactive counting schemes to 'accelerator mass spectrometry.) No Earth material was protected from this assault. The refinement of dating corals, analyzing volcanic rocks for partitioning and chronometer studies and extensions far and wide into ground waters and ocean bottom dwelling organisms has been the consequence of this innovation. Although Ra isotopes, 210Pb and 210Po remain an active pursuit of those doing radioactive measurements, many of these nuclides have also become subject to the mass spectrometric approach. In this volume, for the first time, all the methods for determining the uranium and thorium decay chain nuclides in Earth materials are discussed. The range of problems solvable with this approach is remarkable-a fitting, tribute to the Curies and the early workers who discovered them for us to use.

Description / Table of Contents: Since the dawn of life on earth, organisms have played roles in mineral formation in processes broadly known as biomineralization. This biologically-mediated organization of aqueous ions into amorphous and crystalline materials results in materials that are as simple as adventitious precipitates or as complex as exquisitely fabricated structures that meet specialized functionalities. The purpose of this volume of Reviews in Mineralogy and Geochemistry is to provide students and professionals in the earth sciences with a review that focuses upon the various processes by which organisms direct the formation of minerals. Our framework of examining biominerals from the viewpoints of major mineralization strategies distinguishes this volume from most previous reviews. The review begins by introducing the reader to over-arching principles that are needed to investigate biomineralization phenomena and shows the current state of knowledge regarding the major approaches to mineralization that organisms have developed over the course of Earth history. By exploring the complexities that underlie the "synthesis" of biogenic materials, and therefore the basis for how compositions and structures of biominerals are mediated (or not), we believe this volume will be instrumental in propelling studies of biomineralization to a new level of research questions that are grounded in an understanding of the underlying biological phenomena.

Description / Table of Contents: In the two decades since J. Alexander Speer's Zircon chapter in Orthosilicates (Reviews in Mineralogy, Vol. 5), much has been learned about the internal textures, trace-element and isotope geochemistry (both radiogenic and stable) and chemical and mechanical stability of zircon. The application of this knowledge and the use of zircon in geologic studies have become widespread. Today, the study of zircon exists as the pseudo-discipline of "zirconology" that involves materials scientists and geoscientists from across a range of sub-disciplines including stable and radiogenic isotopes, sedimentology, petrology, trace elements and experimental mineralogy. Zirconology has become an important field of research, so much so that coverage of the mineral zircon in a review volume that included zircon as one of many accessory minerals would not meet the needs or interests of the zirconology community in terms of depth or breadth of coverage. The sixteen chapters in this volume cover the most important aspects of zircon-related research over the past twenty-years and highlight possible future research avenues. Finch and Hanchar (Chapter 1) review the structure of zircon and other mineral (and synthetic) phases with the zircon structure. In most rock types where zircon occurs it is a significant host of the rare-earth elements, Th and U. The abundances of these elements and the form of chondrite-normalized rare-earth element patterns may provide significant information on the processes that generate igneous and metamorphic rocks. The minor and trace element compositions of igneous, metamorphic and hydrothermal zircons are reviewed by Hoskin and Schaltegger in Chapter 2. The investigation of melt inclusions in zircon is an exciting line of new research. Trapped melt inclusions can provide direct information of the trace element and isotopic composition of the melt from which the crystal formed as a function of time throughout the growth of the crystal. Thomas et a!. (Chapter 3) review the study of melt inclusions in zircon. Hanchar and Watson (Chapter 4) review experimental and natural studies of zircon saturation and the use of zircon saturation thermometry for natural rocks. Cation diffusion and oxygen diffusion in zircon is discussed by Cherniak and Watson (Chapter 5). Diffusion studies are essential for providing constraints on the quality of trace element and isotope data and for providing estimates of temperature exposure in geological environments. Zircon remains the most widely utilized accessory mineral for U- Th-Pb isotope geochronology. Significant instrumental and analytical developments over the past thirty years mean that zircon has an essential role in early Achaean studies, magma genesis, and astrobiology. Four chapters are devoted to different aspects of zircon geochronology. The first of these four, Chapter 6 by Davis et a!., reviews the historical development of zircon geochronology from the mid-1950s to the present; the following three chapters focus on particular techniques for zircon geochronology, namely ID-TIMS (Parrish and Noble, Chapter 7), SIMS (Ireland and Williams, Chapter 8) and ICP-MS (Kosier and Sylvester, Chapter 9). The application of zircon chronology in constraining sediment provenance.and the calibration ofthe geologic time-scale are reviewed by Fedo et al. (Chapter 10) and Bowring and Schmitz (Chapter 11), respectively. Other isotopic systematics are reviewed for zircon by Kinny and Maas (Chapter 12), who discuss the application of Nd-Sm and Lu-Hf isotopes in zircon to petrogenetic studies, and by Valley (Chapter 13), who discusses the importance of oxygen isotopic studies in traditional and emerging fields of geologic study. As a host of U and Th, zircon is subject to radiation damage. Radiation damage is likely responsible for isotopic disturbance and promotes mechanical instability. There is increasing interest in both the effect of radiation damage on the zircon crystal structure and mechanisms of damage and recrystallization, as well as the structure of the damaged phase. These studies contribute to an overall understanding of how zircon may behave as a waste-form for safe disposal of radioactive waste and are discussed by Ewing et a!. (Chapter 14). The spectroscopy of zircon, both crystalline and metamict is reviewed by Nadsala et a!. (Chapter 15). The final chapter, by Corfu et al. (Chapter 16), is an atlas of internal textures of zircon. The imaging of internal textures in zircon is essential for directing the acquisition of geochemical data and to the integrity of conclusions reached once data has been collected and interpreted. This chapter, for the first time, brings into one place textural images that represent common and not so common textures reported in the literature, along with brief interpretations of their significance. There is presently no comparable atlas. It is intended that this chapter will become a reference point for future workers to compare and contrast their own images against. The chapters in this volume of Reviews in Mineralogy and Geochemistry were prepared for presentation at a Short Course, sponsored by the Mineralogical Society of America (MSA) in Freiburg, Germany, April 3-4, 2003. This preceded a joint meeting of the European Union of Geology, the American Geophysical Union and the European Geophysical Society held in Nice, France, April 6-11, 2003.

Description / Table of Contents: Several years ago, John Rakovan and John Hughes (colleagues at Miami of Ohio), and later Matt Kohn (at South Carolina), separately proposed short courses on phosphate minerals to the Council of the Mineralogical Society of America (MSA). Council suggested that they join forces. Thus this volume, Phosphates: Geochemical, Geobiological, and Materials Importance, was organized. It was prepared in advance of a short course of the same title, sponsored by MSA and presented at Golden, Colorado, October 25-27. We are pleased to present this volume entitled Phosphates: Geochemical, Geobiological and Materials Importance. Phosphate minerals are an integral component of geological and biological systems. They are found in virtually all rocks, are the major structural component of vertebrates, and when dissolved are critical for biological activity. This volume represents the work of many authors whose research illustrates how the unique chemical and physical behavior of phosphate minerals permits a wide range of applications that encompasses phosphate mineralogy, petrology, biomineralization, geochronology, and materials science. While diverse, these fields are all linked structurally, crystal-chemically and geochemically. As geoscientists turn their attention to the intersection of the biological, geological, and material science realms, there is no group of compounds more germane than the phosphates. The chapters of this book are grouped into five topics: Mineralogy and Crystal Chemistry, Petrology, Biomineralization, Geochronology, and Materials Applications. In the first section, three chapters are devoted to mineralogical aspects of apatite, a phase with both inorganic and organic origins, the most abundant phosphate mineral on earth, and the main mineral phase in the human body. Monazite and xenotime are highlighted in a fourth chapter, which includes their potential use as solid-state radioactive waste repositories. The Mineralogy and Crystal Chemistry section concludes with a detailed examination of the crystal chemistry of 244 other naturally-occurring phosphate phases and a listing of an additional 126 minerals. In the Petrology section, three chapters detail the igneous, metamorphic, and sedimentary aspects of phosphate minerals. A fourth chapter provides a close look at analyzing phosphates for major, minor, and trace elements using the electron microprobe. A final chapter treats the global geochemical cycling of phosphate, a topic of intense, current geochemical interest. The Biomineralization section begins with a summary of the current state of research on bone, dentin and enamel phosphates, a topic that crosses disciplines that include mineralogical, medical, and dental research. The following two chapters treat the stable isotope and trace element compositions of modern and fossil biogenic phosphates, with applications to paleontology, paleoclimatology, and paleoecology. The Geochronology section focuses principally on apatite and monazite for U-ThPb, (U- Th)/He, and fission-track age determinations; it covers both classical geochronologic techniques as well as recent developments. The final section-Materials Applications-highlights how phosphate phases play key roles in fields such as optics, luminescence, medical engineering and prosthetics, and engineering of radionuclide repositories. These chapters provide a glimpse of the use of natural phases in engineering and biomedical applications and illustrate fruitful areas of future research in geochemical, geobiological and materials science. We hope all chapters in this volume encourage researchers to expand their work on all aspects of natural and synthetic phosphate compounds.

Description / Table of Contents: This book is written with two goals in mind. The first is to derive the 32 crystallographic point groups, the 14 Bravais lattice types and the 230 crystallographic space group types. The second is to develop the mathematical tools necessary for these derivations in such a manner as to lay the mathematical foundation needed to solve numerous basic problems in crystallography and to avoid extraneous discourses. To demonstrate how these tools can be employed, a large number of examples are solved and problems are given. The book is, by and large, self-contained. In particular, topics usually omitted from the traditional courses in mathematics that are essential to the study of crystallography are discussed. For example, the techniques needed to work in vector spaces with noncartesian bases are developed. Unlike the traditional group-theoretical approach, isomorphism is not the essential ingredient in crystallographic classification schemes. Because alternative classification schemes must be used, the notions of equivalence relations and classes which are fundamental to such schemes are defined, discussed and illustrated. For example, we will find that the classification of the crystallographic space groups into the traditional 230 types is defined in terms of their matrix representations. Therefore, the derivation of these groups from the point groups will be conducted using the 37 distinct matrix groups rather than the 32 point groups they represent. We have been greatly influenced by two beautiful books. Hermann Heyl's book entitled Symmetry based on his lectures at Princeton University gives a wonderful development of the point groups as well as an elegant exposition of symmetry in art and nature. Fredrik W. H. Zachariasen's book entitled Theory of X-ray Diffraction in Crystals presents important insights on the derivation of the Bravais lattice types and the crystallographic space groups. These two books provided the basis for many of the ideas developed in this book. The theorems, examples, definitions and corollaries are labelled sequentially as a group whereas the problems are labelled separately as a group as are the equations. The manner in which these are labelled is self-explanatory. For example, T4.15 refers to Theorem (T) 15 in Chapter 4 while DAl.l refers to Definition (D) 1 in Appendix (A) 1. We have strived to write this book so that it is self-teaching. The reader is encouraged to attempt to solve the examples before appealing to the solution presented and to work all of the problems. Preface to the Revised Edition of Mathematical Crystallography In the Revised Edition we have corrected the errors, misprints and omissions that we have found and our students and other users have kindly pointed out to us. The Revised Edition also includes a more comprehensive index and a set of solutions for all of the problems presented in the book.

Description / Table of Contents: The first half-century of X-ray crystallography, beginning with the elucidation of the sodium chloride structure in 1914, was devoted principally to the determination of increasingly complex atomic topologies at ambient conditions. The pioneering work of the Braggs, Pauling, Wyckoff, Zachariasen and many other investigators revealed the structural details and underlying crystal chemical principles for most rock-forming minerals (see, for example, Crystallography in North America, edited by D. McLachlan and J. P. Glusker, NY, American Crystallographic Association, 1983). These studies laid the crystallographic foundation for modem mineralogy. The past three decades have seen a dramatic expansion of this traditional crystallographic role to the study of the relatively subtle variations of crystal structure as a function of temperature, pressure, or composition. Special sessions on "High temperature crystal chemistry" were first held at the Spring Meeting of the American Geophysical Union (April 19, 1972) and the Ninth International Congress of Crystallography (August 30, 1972). The Mineralogical Society of America subsequently published a special 11-paper section of American Mineralogist entitled "High Temperature Crystal Chemistry," which appeared as Volume 58, Numbers 5 and 6, Part I in July-August, 1973. The first complete three-dimensional structure refinements of minerals at high pressure were completed in the same year on calcite (Merrill and Bassett, Acta Crystallographica B31, 343-349, 1975) and on gillespite (Hazen and Burnham, American Mineralogist 59, 1166-1176, 1974). Rapid advances in the field of non-ambient crystallography prompted Hazen and Finger to prepare the monograph Comparative Crystal Chemistry: Temperature, Pressure, Composition and the Variation of Crystal Structure (New York: Wiley, 1982). At the time, only about 50 publications documenting the three-dimensional variation of crystal structures at high temperature or pressure had been published, though general crystal chemical trends were beginning to emerge. That work, though increasingly out of date, remained in print until recently as the only comprehensive overview of experimental techniques, data analysis, and results for this crystallographic sub-discipline. This Reviews in Mineralogy and Geochemistry volume was conceived as an updated version of Comparative Crystal Chemistry. A preliminary chapter outline was drafted at the Fall 1998 American Geophysical Union meeting in San Francisco by Ross Angel, Robert Downs, Larry Finger, Robert Hazen, Charles Prewitt and Nancy Ross. In a sense, this volume was seen as a "changing of the guard" in the study of crystal structures at high temperature and pressure. Larry Finger retired from the Geophysical Laboratory in July, 1999, at which time Robert Hazen had shifted his research focus to mineral-mediated organic synthesis. Many other scientists, including most of the authors in this volume, are now advancing the field by expanding the available range of temperature and pressure, increasing the precision and accuracy of structural refinements at non-ambient conditions, and studying ever more complex structures. The principal objective of this volume is to serve as a comprehensive introduction to the field of high-temperature and high-pressure crystal chemistry, both as a guide to the dramatically improved techniques and as a summary of the voluminous crystal chemical literature on minerals at high temperature and pressure. The book is largely tutorial in style and presentation, though a basic knowledge of X-ray crystallographic techniques and crystal chemical principles is assumed. The book is divided into three parts. Part I introduces crystal chemical considerations of special relevance to non-ambient crystallographic studies. Chapter 1 treats systematic trends in the variation of structural parameters, including bond distances, cation coordination, and order-disorder with temperature and pressure, while Chapter 2 considers P-V-T equation-of-state formulations relevant to x-ray structure data. Chapter 3 reviews the variation of thermal displacement parameters with temperature and pressure. Chapter 4 describes a method for producing revealing movies of structural variations with pressure, temperature or composition, and features a series of "flip-book" animations. These animations and other structural movies are also available as a supplement to this volume on the Mineralogical Society of America web site at RiMG041 Programs. Part II reviews the temperature- and pressure-variation of structures in major mineral groups. Chapter 5 presents crystal chemical systematics of high-pressure silicate structures with six-coordinated silicon. Subsequent chapters highlight temperature- and pressure variations of dense oxides (Chapter 6), orthosilicates (Chapter 7), pyroxenes and other chain silicates (Chapter 8), framework and other rigid-mode structures (Chapter 9), and carbonates (Chapter 10). Finally, the variation of hydrous phases and hydrogen bonding are reviewed in Chapter 11, while molecular solids are summarized in Chapter 12. Part III presents experimental techniques for high-temperature and high-pressure studies of single crystals (Chapters 13 and 14, respectively) and polycrystalline samples (Chapter 15). Special considerations relating to diffractometry on samples at non-ambient conditions are treated in Chapter 16. Tables in these chapters list sources for relevant hardware, including commercially available furnaces and diamond-anvil cells. Crystallographic software packages, including diffractometer operating systems, have been placed on the Mineralogical Society web site for this volume. This volume is not exhaustive and opportunities exist for additional publications that review and summarize research on other mineral groups. A significant literature on the high-temperature and high-pressure structural variation of sulfides, for example, is not covered here. Also missing from this compilation are references to a variety of studies of halides, layered oxide superconductors, metal alloys, and a number of unusual silicate structures.

Description / Table of Contents: Unlike sedimentation and volcanism, active metamorphism is not directly observable. Metamorphic petrologists therefore must infer what constitutes the process of metamorphism by examining the products of metamorphic events. The purpose of this volume is to review the use of a powerful probe into metamorphic process: mineral assemblages and the composition of minerals. Put very simply, this volume attempts to answer the question: "What can we learn about metamorphism through the study of minerals in metamorphic rocks?" It is not an encyclopedic summary of metamorphic mineral assemblages; instead it attempts to present basic research strategies and examples of their application. Moreover, in order to limit and unify the subject matter, it concentrates on the chemical aspects of metamorphism and regrettably ignores other important kinds of studies of metamorphic rocks and minerals conducted by structural geologists, structural petrologists, and geophysicists. An overview of the chemical aspects of modern metamorphic petrology is timely because it brings together three areas of research which have reached maturity only in the last 25 years: (1) chemical analysis of minerals by microanalytical techniques; (2) application of reversible and irreversible thermodynamics to petrology; and (3) laboratory phase equilibrium experiments involving metamorphic minerals. Chemical thermodynamics is the formal mathematical framework which links measurable variables (i.e., mineral composition) to metamorphic variables which cannot be directly measured (i.e., chemical potential, pressure, temperature, fluid composition). Results of phase equilibrium studies involving metamorphic minerals at metamorphic pressures and temperatures (together with calorimetric and heat capacity data) permit these links to be quantitative. It is the union of analysis, theory, and laboratory experiment which allows the modern metamorphic petrologist to make sophisticated inferences about conditions of metamorphism and the factors which control these conditions. This union is the principal subject of the volume. The volume is organized much in the same way that one might approach a research project involving metamorphic rocks. Initially those chemical components which characterize the composition of minerals in the assemblages under consideration must be identified. In addition, the reaction relationships among components must be systematically characterized. The reaction relationships rationalize the prograde changes in mineralogy which rocks experience during metamorphism and, furthermore, form the basis for extracting information about intensive variables during metamorphism. Chapters 1-3 summarize strategies for identifying components in metamorphic minerals and for formulating chemical reactions among them. Chapter 4 develops, from classical thermodynamics, those equations which can be used to explicitly relate mineral composition to other variables of interest such as metamorphic pressure, temperature, and chemical potentials of volatile species in any metamorphic fluid phase. Chapter 5 is specifically devoted to geologic thermometry and barometry, and Chapter 6 reviews strategies for the determination of metamorphic fluid composition. Petrologists should not be content with simply calculating and cataloguing values of metamorphic pressure, temperature, and fluid composition. In order to characterize the process of metamorphism, we must try to understand what controls these measured values and the manner in which they evolve during metamorphism both as rocks are heated and buried and as rocks are cooled and uplifted. Chapter 7 explores how two concepts buffering and infiltration -- can act as general controls on fluid composition, mineral composition, and temperature during metamorphic events. In addition, this chapter develops procedures which can be used to evaluate the relative importance of buffering versus infiltration in the evolution of specific rocks. Chapter 8 demonstrates how integrated petrologic and stable isotope studies may be used, in principle, to reconstruct the prograde pressure-temperature-infiltration history of metamorphic rocks. Chapter 9 discusses the use of mineral inclusions and compositional zoning in minerals in evaluating both prograde and post-peak P-T paths of certain mineral assemblages. In addition, compositional zoning is considered as an indicator of cooling rates during post-peak uplift. Thus between Chapter I and Chapter 9 we go from the first step of describing a metamorphic mineral assemblage through a reconstruction of the physical state in which it crystallized to an analysis of what factors controlled that state and how it evolved with time. The contents of the volume reflect two themes which underlie modern research in metamorphic petrology. The first of these is an ever-increasing emphasis on the quantitative characterization of metamorphism. Current research less involves description and classification than calculation of intensive and extensive variables attained during metatamorphism. This volume hopefully serves as a text in the quantitative study of the chemical aspects of metamorphism. As a corollary to the emphasis placed on quantitative methods, we can see increasing attention paid to analytical as opposed to graphical treatments of mineral equilibria. Graphical representations, while undeniably valuable, can consider two (or at most three) independent variables. Analytical treatment of mineral equilibria is attractive because it rigorously keeps track of all variables pertinent to an equilibrium assemblage. The second theme is an increasing interest in the dynamics of metamorphism. Metamorphism obviously is not a static process -- it involves changes in pressure, temperature, mineral and fluid composition, etc. The classical static approach to quantitative metamorphic petrology, though, searches for the physical conditions of a unique pressure-temperature state which a rock or mineral assemblage records. Mineral equilibria are used to estimate single values of pressure, temperature, and fluid composition -- a sort of snapshot of what conditions were like. If mineral assemblages indeed represent a fossilized metamorphic state, then calculated P, T, Xi' however, simply represent a single point along the P-T-Xi-time path which a rock followed during metamorphism. Chapters 2, 7, 8, and 9 reflect an increasing interest among petrologists in the entire P-T-Xi-time path (or at least in more than one point along it). We can expect to see less satisfaction in the future with the snapshot model of metamorphism and more effort devoted to characterizing metamorphism as a dynamic process. Thus the volume not only summarizes time-honored current practices in quantitative metamorphic petrology, but hopefully also identifies some paths which may be followed in the future.

Description / Table of Contents: At the time of the first printing (1996), interest in the element boron was growing rapidly. We felt that it was an opportune moment to ask investigators active in research on boron to review developments in their respective fields so that readers could learn what was-and wasn't-known about boron and its minerals, geochemistry and petrology. Since 1996, interest in boron has, if anything, increased, and continued demand for the Reviews in Mineralogy "boron bible" has motivated the Mineralogical Society of America to reprint the volume. Demand is reflected in citations, and according to ISI's Science Citation Index, the number of citations since publication to the volume is about 380, with some individual chapters having been cited as many as 44 times. In preparation for this printing, authors of 15 of the 19 original chapters have updated, corrected or added to their chapters within the constraints that no pages be added. Most addenda are bibliographies of literature published since 1996; a few also include summaries of significant findings. Addenda for each chapter follow the chapter, except for those for Chapters 1 and 2, which are merged onto pages 115-116 and 385. A table of new B-minerals since 1996 is given on p. 28, and many modifications were made to the table (p. 7-27) of B-minerals known prior to 1996 (corrections to formulae, mineral names, localities, etc.). Similar up-datings of Table 1 (p. 223) in Chapter 5 and numerous tables in Chapter 9 (p. 387) were undertaken, and Figure 15 in Chapter 11 (p. 619), which-embarrassingly-was missing from the first printing, has been supplied. Addenda to Chapter 13 are introduced on p. 744 and completed on p. 863 and 864. The following salient developments in research related to B are mentioned in the addenda: New minerals. Twenty-two boron minerals have been or are about to be described, and four more have been approved by the International Mineralogical Association, representing an increase of 10%, comparable to the increase in the number of all new minerals described during the same period (Anovitz and Grew, Chapter 1) Tourmaline group. In addition to four new tourmaline species, a new classification has been proposed. Another tourmaline, olenite, has been shown to contain substantial amounts of excess B in tetrahedral coordination, a finding that has revolutionized our view of tourmaline crystal chemistry (Werding and Schreyer, Chapter 3; references in addendum to Henry and Dutrow, Chapter 10). Boron isotopes. New techniques for measuring isotope ratios using secondary ion mass spectroscopy (SIMS) with the ion microprobe open up new opportunities for in situ analyses of individual grains and fluid inclusions (Hervig, Chapter 16). Boron isotopes have found applications in paleoceanography and thus add to the tools available for the study of past climates (Palmer and Swihart, Chapter 13). One of the major questions facing the use of hydrogeochemical models is whether or not they can be used with confidence to predict future evolution of groundwater systems. There is much controversy concerning the validity and uncertainties of non-reactive fluid flow systems. Adding chemical interaction to these flow models only confounds the problem. Although such models may accurately integrate the governing physical and chemical equations, many uncertainties are inherent in characterizing the natural system itself. These systems are inherently heterogeneous on a variety of scales rendering it impossible to know precisely the many details of the flow system and chemical composition of the host rock. Other properties of natural systems such as permeability and mineral surface area, to name just two, may never be known with any great precision, and in fact may be unknowable. Because of these uncertainties, it remains an open question as to what extent numerical models of groundwater flow and reactive transport wilI be useful in making accurate quantitative predictions. Nevertheless, reactive transport models should be able to predict the outcome for the particular representation of the porous medium used in the model. Finally, it should be mentioned that numerical models are often our only recourse to analyze such environmental problems as safe disposal of nuclear waste where predictions must be carried out over geologic time spans. Without such models it would be impossible to analyze such systems, because they involve times too long to perform laboratory experiments. The results of model calculations may affect important political decisions that must be made. Therefore, it is all the more important that models be applied and tested in diverse environments so that confidence and understanding of the limitations and strengths of model predictions are understood before irreversible decisions are made that could adversely affect generations to come.

Description / Table of Contents: The Mineralogical Society of America sponsored a short course on Contact Metamorphism, October 17-19, 1991, at the Pala Mesa Resort, Fallbrook, California, prior to its annual meeting with the Geological Society of America. As reviewed in Chapter 1, contact aureoles have unique attributes for elucidating the processes and controls of metamorphism. Within the last two decades there has been considerable evolution in our knowledge of metamorphism. This evolution spans a wide range of scales from submicroscopic analysis of grain boundaries through to regional scale analysis of contact metamorphism associated with batholith terrains. Geological sciences is becoming increasingly multidisciplinary in nature. Traditionally, contact aureoles were primarily studied by metamorphic petrologists. Their mapping of isograds and mineral zones in aureoles, coupled with microscopic analysis of the prograde metamorphic evolution of textures, structures and mineralogy, has provided an excellent framework for our understanding of contact metamorphism. However, complete understanding of the processes and controls of contact metamorphism requires a multidisciplinary analysis from a wide range of geological subdisciplines. This volume provides a multidisciplinary review of our current knowledge of contact metamorphism. As in any field of endeavor, we are provided with new questions, thereby dictating future directions of study. Hopefully, this volume will provide inspiration and direction for future research on contact metamorphism.

Description / Table of Contents: This is a book exclusively devoted to three minerals: the Al2SiO5 polymorphs - andalusite, sillimanite, and kyanite. This may seem to be narrowly focused and esoteric. However, as discussed in Chapter 1, the aluminum silicate polymorphs are perhaps the most important mineral group to metamorphic petrologists. Because these minerals occur in anatectic migmatites and peraluminous granitoids, they are also important in igneous petrology. In spite of their geologic significance, there are a variety of experimental, theoretical, and field problems involving the aluminum silicates. Theoretical problems include the nature and energetics of lattice defects, order/disorder, crystalline (solid) solution, and interfacial energy. The aluminum silicates epitomize the importance of understanding the mechanisms and kinetics of heterogeneous metamorphic reactions. The difficulties in calibration of the pressure-temperature (P- T) phase equilibrium diagram illustrate the pitfalls of hydrothermal experimentation and the need to understand the methodology and uncertainties of calorimetric measurements of thermodynamic data of minerals. Thus, this book covers a wide variety of topics that must be considered in the analysis of metamorphic systems. In so doing, this volume illustrates the fact that modern metamorphic petrology demands an awareness of a wide spectrum of geologic variables and processes. In concert with the tenor of the Mineralogical Society of America Reviews in Mineralogy series, this volume is intended to provide a comprehensive review, summarizing the methods, theories and pitfalls of the various contributions on the aluminum silicates. Hopefully, this book will provide readers with a reasonably in-depth overview, and thus avoid the need for extensive, independent literature reviews. Although a concerted effort was made to give a balanced coverage of divergent theories regarding various problems involving the aluminum silicates, this critique nevertheless includes some of the author's biases. Several sections of this book present the chronological development of research on various topics, giving readers historical perspectives on the development of theories, models and biases on various problems regarding the aluminum silicates. As in all fields, several landmark studies have set the tone for the strategy of approach to problems. Although such studies have provided important steps forward in our understanding of natural phenomena, they have had the undesirable effect of entrenching biases and methodology. In this volume I have attempted to point out the deleterious effects of certain parochial approaches, an example being the aluminum immobility concept discussed in Chapter 10. In addition to their primary importance in metamorphic petrology, the aluminum silicates illustrate a wide variety of experimental, theoretical, and experimental problems. Because the Al2SiO5 polymorphs alone offer a pedagogic illustration of many important principles of modern metamorphic petrology.