In August 1990, Project 233 of the International Geological Correlation Program hosted an international conference in G6ttingen/Giessen, Germany. Discussions were focused on the Tectonothermal and Stratigraphic Evolution of the Central European Orogens. The meeting marked the first opportunity for completely open scientific exchange following the recent political reformations in central Europe. This exciting new atmosphere of international cooperation resulted in presentation of a wealth of information which was new to scientists from both sides of former political boundaries. It was apparent that a unique opportunity was available to prepare a systematic overview in a volume dealing with the geology of Central Europe. The present book represents an outgrowth of this conference, but is not merely a compilation of the papers presented in G6ttingen/Giessen. Instead, it represents a coordinated volume designed to present a balanced, comprehensive view of our present understanding of the tectonothermal and stratigraphic evolution of the Central European orogens. We gratefully acknowledge the help of the national funding agencies, who have financed much of the research work summarized in this book, and of the Interna­ tional Geological Correlation Programme (IGCP, project no. 233) which provided and helped to finance the organisational framework. We are indebted to Springer-Verlag for thorough copy-editing and production of this book, and we sincerely appreciate the efforts of all the reviewers whose com­ ments have greatly helped to improve the quality of this volume. We also thank the various contributors for their diligence and perseverance in manuscript preparation.

Pre-Mesozoic Geology of Iberia is a major reference for current understanding of the overall tectonostratigraphic evolution of the Iberian Massif. It represents a comprehensive overview which systematically describes characteristics of the seven major lithotectonic elements of the Iberian Massif in terms of: - stratigraphy, - paleontology, - sedimentology, - structural geology, - igneous activity, - metamorphic evolution, - metallogenesis, and - tectonic significance. These data are compiled in several concluding summary chapters which discuss the overall geodynamic evolution of the Iberian Massif and outline its tectonic setting within the overall circum-Atlantic region. Readers will benefit by this comprehensive review of an important tectonostratigraphic element in the circum-Atlantic realm.

In December, 1987, Project 233 of the International Geological Correlation Pro­ gram hosted an international conference in Nouakchott, Mauritania. Discussions were focused on the "Tectonothermal Evolution Of The West Mrican Orogens And Circum-Atlantic Terrane Linkages". A wealth of new information was pre­ sented during the conference, and it was apparent that the time was appropriate to prepare a systematic volume dealing with the geology of northwest Mrica. The present volume is an outgrowth of this conference, but is not merely a compilation of the papers presented in Nouakchott. Instead, it represents a coordinated vol­ ume designed to present a balanced, comprehensive view of our present under­ standing of West Mrican geology and potential correlations in other Circum-At­ lantic Paleozoic orogens. We sincerely appreciate the efforts of all the reviewers whose comments have greatly helped to improve the quality of this volume. We also thank the various contributors for their diligence and perseverance in manuscript preparation. The calibre of the present volume is a reflection of their labor. Athens/Marseille, Autumn 1990 R. D. DALLMEYER J. P. LECORCHE Contents Chapter 1 Introduction . . . . . . . . . . . . . . . 3 R. D. DALLMEYER and J. P. LECORCHE Chapter 2 Geophysics and the Crustal structure of West Africa 9 J. ROUSSEL and A. LESQUER Chapter 3 Crystalline Basement of the West African Craton . . . . . . . . . . . . .. . . 31 .

In August 1990, Project 233 of the International Geological Correlation Program hosted an international conference in G6ttingen/Giessen, Germany. Discussions were focused on the Tectonothermal and Stratigraphic Evolution of the Central European Orogens. The meeting marked the first opportunity for completely open scientific exchange following the recent political reformations in central Europe. This exciting new atmosphere of international cooperation resulted in presentation of a wealth of information which was new to scientists from both sides of former political boundaries. It was apparent that a unique opportunity was available to prepare a systematic overview in a volume dealing with the geology of Central Europe. The present book represents an outgrowth of this conference, but is not merely a compilation of the papers presented in G6ttingen/Giessen. Instead, it represents a coordinated volume designed to present a balanced, comprehensive view of our present understanding of the tectonothermal and stratigraphic evolution of the Central European orogens. We gratefully acknowledge the help of the national funding agencies, who have financed much of the research work summarized in this book, and of the Interna­ tional Geological Correlation Programme (IGCP, project no. 233) which provided and helped to finance the organisational framework. We are indebted to Springer-Verlag for thorough copy-editing and production of this book, and we sincerely appreciate the efforts of all the reviewers whose com­ ments have greatly helped to improve the quality of this volume. We also thank the various contributors for their diligence and perseverance in manuscript preparation.

Pre-Mesozoic Geology of Iberia is a major reference for current understanding of the overall tectonostratigraphic evolution of the Iberian Massif. It represents a comprehensive overview which systematically describes characteristics of the seven major lithotectonic elements of the Iberian Massif in terms of: - stratigraphy, - paleontology, - sedimentology, - structural geology, - igneous activity, - metamorphic evolution, - metallogenesis, and - tectonic significance. These data are compiled in several concluding summary chapters which discuss the overall geodynamic evolution of the Iberian Massif and outline its tectonic setting within the overall circum-Atlantic region. Readers will benefit by this comprehensive review of an important tectonostratigraphic element in the circum-Atlantic realm.

In December, 1987, Project 233 of the International Geological Correlation Pro­ gram hosted an international conference in Nouakchott, Mauritania. Discussions were focused on the "Tectonothermal Evolution Of The West Mrican Orogens And Circum-Atlantic Terrane Linkages". A wealth of new information was pre­ sented during the conference, and it was apparent that the time was appropriate to prepare a systematic volume dealing with the geology of northwest Mrica. The present volume is an outgrowth of this conference, but is not merely a compilation of the papers presented in Nouakchott. Instead, it represents a coordinated vol­ ume designed to present a balanced, comprehensive view of our present under­ standing of West Mrican geology and potential correlations in other Circum-At­ lantic Paleozoic orogens. We sincerely appreciate the efforts of all the reviewers whose comments have greatly helped to improve the quality of this volume. We also thank the various contributors for their diligence and perseverance in manuscript preparation. The calibre of the present volume is a reflection of their labor. Athens/Marseille, Autumn 1990 R. D. DALLMEYER J. P. LECORCHE Contents Chapter 1 Introduction . . . . . . . . . . . . . . . 3 R. D. DALLMEYER and J. P. LECORCHE Chapter 2 Geophysics and the Crustal structure of West Africa 9 J. ROUSSEL and A. LESQUER Chapter 3 Crystalline Basement of the West African Craton . . . . . . . . . . . . .. . . 31 .