Afrique de l'Ouest

Afrique de l'Ouest
Author: J.M. Bertrand
Publisher: Elsevier
Total Pages: 402
Release: 2013-10-22
Genre: Science
ISBN: 1483138267

Afrique de l'Ouest

Mineralization and Sustainable Development in the West African Craton

Mineralization and Sustainable Development in the West African Craton
Author: T. Aïfa
Publisher: Geological Society of London
Total Pages: 357
Release: 2021-07-22
Genre: Science
ISBN: 1786204894

This Special Publication combines results obtained by interdisciplinary groups from numerous academic institutions working on Paleoproterozoic formations to decipher the origins of the main mineralization resources in the West African Craton (WAC) and their impacts on African economic development. Structural, geophysical, sedimentological, stratigraphical, geochemical, petrophysical and mineralogical analyses have been used to highlight the complexities involved in mineralization emplacement and its origin and evolution within the WAC. Fourteen articles contribute to new knowledge in mineral research. They show that the geodynamic evolution of the WAC is complex from one area to another: it involves subduction, collision and obduction during several deformation phases ranging from Birimian (2.3–2.0 Ga) to Pan-African (650–450 Ma) events. Various modelling techniques, when integrated, help in understanding the mechanisms of mineralization emplacement, some of which are still a matter of debate. The challenge for further studies is mitigation for sustainable development that can be appropriately used to minimize such damage.

The West African Orogens and Circum-Atlantic Correlatives

The West African Orogens and Circum-Atlantic Correlatives
Author: R.D. Dallmeyer
Publisher: Springer Science & Business Media
Total Pages: 846
Release: 2012-12-06
Genre: Science
ISBN: 3642841538

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 .

Phanerozoic Stromatolites II

Phanerozoic Stromatolites II
Author: Janine Bertrand-Sarfati
Publisher: Springer Science & Business Media
Total Pages: 470
Release: 2012-12-06
Genre: Science
ISBN: 9401111243

Precambrian stromatolites have received in depth, consideration from geologists and paleontologists; they were indeed searching for biosedimentary structures that were sufficiently characteristic and widely distributed to be considered as useful tools for stratigraphic correlation. Silicified stromatolites are also of interest as they contain preserved traces of ancient life. Calcareous Phanerozoic stromatolites have not received very much attention from geologists. Logan's too schematic morphological classification of 1964, was not so helpful to the knowledge of Phanerozoic stromatolites because neither their morphology nor their microstructure were studied in the same detail in which Proterozoic stromatolites have now been described. We therefore know little about the Phanerozoic stromatolites which, do, however, show an interesting range of diversification. A major questions stiII remaining to be answered include the history of stromatolite development and wether their morphology has "evolved" in addition to detailed information concerning Cenozoic nonmarine stromatolites which precipitate carbonate and the Recent giant stromatolites which trap particles. For these reasons Claude Monty, in 1981, launched the first volume of what was going to be a series on "Phanerozoic stromatolites" in order to describe their morphology, microstructure and paleoecology and to present them in their stratigraphic context.

Paleoecology, Biostratigraphy, Paleoceanography and Taxonomy of Agglutinated Foraminifera

Paleoecology, Biostratigraphy, Paleoceanography and Taxonomy of Agglutinated Foraminifera
Author: Christoph Hemleben
Publisher: Springer Science & Business Media
Total Pages: 1002
Release: 2012-12-06
Genre: Science
ISBN: 9401133506

Agglutinated foraminifera are among the most widely distributed and abundant groups of marine meiofauna in some environments (e. g. marshes, deep-sea). They are tolerant of environmental extremes, tending to live where the evolutionarily more advanced calcareous foraminifera cannot survive. However, largely because of historical reasons, the amount of scientific effort invested in this group has been small in comparison to studies of other marine organisms. The NATO Advanced Studies Institute conference on the paleoecology, biostratigraphy, paleoceanography and taxonomy of agglutinated foraminifera in TUbingen September 17-29, 1989, was a direct outgrowth of two previous workshops on agglutinated foraminifers held in Amsterdam in September 1981 (IW AF I) and in Vienna in June 1986 (IW AF 11). As such, the TUbingen conference constitutes the Third International Workshop on Agglutinated Foraminifera (IW AF III) and was organised to provide a platform for synthesizing the current state of knowledge on this group of organisms, and to strengthen interactions between basic research and applied micropaleontology. One of the main underlying themes of the conferen:e was to identify topics in the paleoecology, biostratigraphy, paleoceanography and taxonomy of agglutinated foraminifera which are in urgent need of further research. About 80 scientists and students from 5 continents participated in the TUbingen conference, which is one measure of the growth in interest in agglutinated foraminifers over the past decade. During four days of technical sessions, scientific results were communicated in the form of 34 oral presentations and 15 poster displays.