The continental margins of the world constitute the most impressive and largest physiographic feature of the earth's surface, and one of fundamentally great geological significance. Continental margins have been the subject of increasing attention in recent years, an interest focused by a body of new data that has provided new insights into their character. This interest was further stimulated by the realization that, in addition to the abundant living resources, continental margins contain petroleum and mineral resources that are accessible with existing technology. This realization, along with their basic geological importance, has provoked further research into the nature of continental margins throughout the world. A summary of these findings, as related to both recent and ancient continental margins, is the subject of this book. At various times in the past we had been approached individually to prepare a basic reference to continental margins; we then proposed to do such a volume jointly. However, the stimulus for the present volume eventually arose from a Penrose Conference arranged through the Geological Society of America. This conference was attended by specialists of numerous disciplines and from throughout the world, many of whom insisted that such a volume would be both timely and useful. Consequently, we agreed to undertake the task of assembling this book, with the objectives of making it available as soon and as inexpensively as possible.

A group of geoscientists from a number of NATO countries met under NATO sponsorship in Copenhagen on February 27 and 28, 1978, and formulated a proposal entitled "EVOLUTION OF THE GREENLAND ICELAND-FAEROE-SCOTLAND RIDGE, A KEY AREA IN MARINE GEOSCIENCE". This part of the North Atlantic Ocean is of particular interest because of its anomalously shallow bathymetry which has profoundly influenced many aspects of the evolution of the North Atlantic. The proposed investigations therefore aim to study the deep crustal structure including relationship of continental and oceanic crust, history of subsidence of the ridge including its past role as a land bridge, age of the oceanic basement along it and its history of formation, and the influence of the ridge on Tertiary and Quaternary depositional palaeoenvironments. In furtherance of this proposal, it is intended to carry out a series of seismic and drilling operations on the Ridge during the coming years. These major marine investigations will be mainly funded from national sources. An important preliminary stage to the project is the collec tion and synthesis of available data. NATO has already approved a small budget for this purpose which has enabled a geoscientist to work partly at the Department of Geological Sciences of Durham University, UK, and partly at Lamont-Doherty Geological Observatory of Columbia University, Palisades, USA, for about six months to compile the data. The most important map showing magnetic anomalies and lineations in the area, is included in a pocket at the back of this volume.

The NAG-TEC project was a collaborative effort by the British Geological Survey, the Geological Survey of Denmark and Greenland, the Geological Survey of Ireland, the Geological Survey of the Netherlands, the Geological Survey of Northern Ireland, the Geological Survey of Norway, Iceland GeoSurvey and the Faroese Geological Survey (Jarðfeingi), along with a number of academic partners and significant support from industry. The main focus was to investigate the tectonic evolution of the region with a particular emphasis on basin evolution along conjugate margins. A key outcome was the development of a new tectonostratigraphic atlas and database that includes comprehensive geological and geophysical information relevant for understanding the Devonian to present evolution of the NE Atlantic margins. These provide the foundation upon which ongoing research and exploration of the area can build. This Special Publication provides some of the first scientific results and analysis based on the project, including regional stratigraphic analysis and correlations, crustal structure and interpretation of geophysical data sets, plate kinematics and the evolution of igneous provinces.

The explosion of interest, effort, and information about the ocean since about 1950 has produced many thousand scientific articles and many hun dred books. In fact, the outpouring has been so large that authors have been unable to read much of what has been published, so they have tended to concentrate their own work within smaller and smaller subfields of oceanog raphy. Summaries of information published in books have taken two main paths. One is the grouping of separately authored chapters into symposia type books, with their inevitable overlaps and gaps between chapters. The other is production of lightly researched books containing drawings and tables from previous pUblications, with due credit given but showing assem bly-line writing with little penetration of the unknown. Only a few books have combined new and previous data and thoughts into new maps and syntheses that relate the contributions of observed biological, chemical, geological, and physical processes to solve broad problems associated with the shape, composition, and history of the oceans. Such a broad synthesis is the objective of this book, in which we tried to bring together many of the pieces of research that were deemed to be of manageable size by their originators. The composite may form a sort of plateau above which later studies can rise, possibly benefited by our assem bly of data in the form of new maps and figures.

This volume has evolved from papers written in memory of Professor David Roberts. They summarize the key findings of recent research on passive margins, from tectonics, bathymetry, stratigraphy and sedimentation, structural evolution and magmatism. Papers include analyses of the central and southern Atlantic margins of South America and Africa, papers on magmatism and extension in the NE Brazilian margin and on the Cote de Ivoire margin, rift architectures of the NW Red Sea margin, tectonics of the eastern Mediterranean margin, salt tectonics of passive margins of the Gulf of Mexico and Brazil, and papers on the NW Shelf margin of Australia. The volume provides readers with new insights into the complexities of passive margin systems that are in reality, not so passive.

Continental margins form the relatively narrow transition zones between the different domains of land masses and deep-ocean basins. They are the main regions of sediment input and transfer of sediments to the oceans and thus represent important zones of sediment flux. This work addresses three topics of significance to continental margin development: sedimentation, mass-wasting and stability. It should be of interest to marine geologists, sedimentologists, palaeoceanographers and physical properties specialists.