1 2 J. H. SCHROEDER and B. H. PURSER 1 Introduction A symposium convened during the Vth International Coral Reef Congress in Papeete, Tahiti, 1985, encouraged the editors to assemble this volume of case studies by participating and, especially, by nonparticipating scientists. An attempt was made to include case studies from various regions and geological periods, carried out on various scales from regional to ultrastructural. We hope to present an overall view of reef diagenesis. Although the volume focuses on reef diagenesis, fields also to be considered are biology, paleontology, and sedimentary facies distribution, as they provide the context and, to some extent, encompass the determinants of diagenetic processes. The scope has been limited to reef diagenesis because we feel that reefs have relatively clearly defined geometries, which facilitate the evaluation of diagenetic trends and the definition of diagenetic models. On the other hand, their many different components make reefs somewhat more complex than other deposits, and this creates difficulties in deciphering diagenetic histories; the study of reefs, therefore, is not the simplest manner of solving the many problems relating to carbonate diagenesis. An additional reason for evaluating reef diagenesis is the reservoir potential of these carbonate bodies. To illustrate the point, in the recent collection of 35 case studies of carbonate reservoirs (Roehl and Choquette 1985), reefs were involved in 15. The emphasis on porosity development in many studies of the present volume is therefore not of mere academic interest.

Coral reefs are the largest landforms built by plants and animals. Their study therefore incorporates a wide range of disciplines. This encyclopedia approaches coral reefs from an earth science perspective, concentrating especially on modern reefs. Currently coral reefs are under high stress, most prominently from climate change with changes to water temperature, sea level and ocean acidification particularly damaging. Modern reefs have evolved through the massive environmental changes of the Quaternary with long periods of exposure during glacially lowered sea level periods and short periods of interglacial growth. The entries in this encyclopedia condense the large amount of work carried out since Charles Darwin first attempted to understand reef evolution. Leading authorities from many countries have contributed to the entries covering areas of geology, geography and ecology, providing comprehensive access to the most up-to-date research on the structure, form and processes operating on Quaternary coral reefs.

Over the years, many papers on carbonate diagenesis have been published in Sedimentology, the journal of the International Association of Sedimentologists. This volume presents a collection of these papers with a commentary. The emphasis of the book is on the diagenesis of shallow-marine carbonate sediments and the editors have chosen 12 papers which are reproduced in full. To widen the scope of this volume the abstracts for another 16 papers are presented. These provide further examples of diagenetic studies and help to extend the coverage of the book. The reprints and abstracts are divided into three groups, dealing with marine, meteoric and burial diagenesis respectively. Each collection is preceded by a commentary which briefly summarizes the topic and introduces the reprints and abstracts to come

The soul rejoices in perceiving harmonious sound; when the sound is not harmonious it is grieved. From these affects of the soul are derived the name of consonances for the harmonic proportions, and the name of dissonances for the unharmonic proportions. When to this is added the other harmonie proportion whieh consists of the longer or shorter duration of musical sound, then the soul stirs the body to jumping dance, the tongue to inspired speech, according to the same laws. The artisans accommodate to these harmonies the blows of their hammers, the soldiers their pace. As long as the harmonies endure, everything is alive; everything stiffens, when they are disturbed.! Thus the German astronomer, Johannes Kepler, evokes the power of music. Where does this power come from? What properties of music enable it to stir up emotions which may go far beyond just feeling generally pleased, and which may express themselves, for instance, in weeping; in laughing; in trembling over the whole body; in a marked acceleration of breathing and heartbeat; in participating in the rhythm with the head, the hands, the arms, and the feet? From the beginning of musical theory the answer to this question has been sought in two different directions.

Carbonate diagenesis is a subject of enormous complexity because of the basic chemical reactivity of carbonate minerals. These carbonate minerals react quickly with natural waters that either dissolve the carbonates, or precipitate new carbonates to bring the water into equilibrium with the host carbonate sediments and rocks. These rock-water interactions either create porosity by dissolution, or destroy porosity by the precipitation of carbonate cements into pore spaces. Carbonate Diagenesis and Porosity examines these important relationships in detail.This volume is published in co-operation with OGCI, and is based on training courses organised by OGCI and taught by Dr. Moore. It is intended to give the working geologist and university graduate student a reasonable overview of carbonate diagenesis and its influence on the evolution of carbonate porosity. It starts with a discussion of the major differences between carbonates and siliciclastics so that the novice will have an appreciation of the basic nature of the carbonate system. Carbonate porosity, its nature and its classification is then discussed so that the relationship between diagenesis and porosity can be established. Environments of diagenesis and their characteristics are outlined, stressing the nature of pore fluids found in each environment. Tools for the recognition of these environments are then discussed with stress on the constraints suffered by each technique. Each major diagenetic environment is then discussed in detail with petrographic, geochemical characteristics outlined, and an in depth discussion of the impact of the environment's diagenetic processes on porosity development and evolution. Diagenetic models are developed where appropriate and criteria for recognition listed. Case histories illustrating these concepts and models are presented for each major diagenetic environment and sub-environment.Over 160 line drawings illustrate the book. Petrographic characteristics of porosity and diagenetic fabrics and textures are illustrated using numerous photomicrographs taken specifically for the book by the author. The book has been extensively indexed, and includes a large, current reference section.This book should be useful to any geologist interested in, or working with, carbonate sediments and rocks. It will be particularly useful to the industrial geologist concerned with the exploration or exploitation of hydrocarbons from carbonate rock sequences where an understanding of porosity development, evolution, and prediction are important. In addition, this book will be a good text for advanced carbonate courses at graduate level, and an appropriate reference book for graduate students working in, or interested in, carbonate rock sequences and sediments.

This book presents both state-of-the art knowledge from Recent coral reefs (1.8 million to a few centuries old) gained since the eighties, and introduces geologists, oceanographers and environmentalists to sedimentological and paleoecological studies of an ecosystem encompassing some of the world's richest biodiversity. Scleractinian reefs first appeared about 300 million years ago. Today coral reef systems provide some of the most sensitive gauges of environmental change, expressing the complex interplay of chemical, physical, geological and biological factors. The topics covered will include the evolutionary history of reef systems and some of the main reef builders since the Cenozoic, the effects of biological and environmental forces on the zonation of reef systems and the distribution of reef organisms and on reef community dynamics through time, changes in the geometry, anatomy and stratigraphy of reef bodies and systems in relation to changes in sea level and tectonics, the distribution patterns of sedimentary (framework or detrital) facies in relation to those of biological communities, the modes and rates of reef accretion (progradation, aggradation versus backstepping; coral growth versus reef growth), the hydrodynamic forces controlling water circulation through reef structures and their relationship to early diagenetic processes, the major diagenetic processes affecting reef bodies through time (replacement and diddolution, dolomitization, phosphatogenesis), and the record of climate change by both individual coral colonies and reef systems over the Quaternary. * state-of-the-art knowledge from Recent corals reefs* introduction to sedimentological and paleoecological studies of an ecosystems encompassing some of the world's richest biodiversity.* authors are internationally regarded authorities on the subject* trustworthy information

Carbonate Reservoirs: Porosity, Evolution and Diagenesis in a Sequence Stratigraphic Framework