ALBERT

Description / Table of Contents: PREFACE The papers contained in the present volume were prepared from the contributions presented during an international Advanced Workshop held in Santander, Cantabria, Spain between 1-5 November 1989. The workshop was a joint activity of the Working Group on Geology and Land-Use Planning (program "Geology and Environment", UNESCO), the Commission on Applied Quaternary Research (INQUA), the Sub-Commission on Maps of Environmental Geology (Commission of the Geological Map of the World) and the Grupo Españiol de Geología Ambiental y Ordenación del Territorio (Spanish Association for Environmental Geology and Land-Use Planning). The aims of the meeting were to discuss a series of topics in which the four participating scientific bodies share an interest, to analyze the existing problems and trends and to identify certain lines along which work and/or actions will be particularly necessary in the near future. It was expected that the discussions and the conclusions of the meeting would provide useful guidelines for earth scientists working on environmental problems and for other professionals and officials who deal with environmental analysis, planning and management, either on a scientific basis or in a decision-making capacity...

Description / Table of Contents: Introduction / Pages 1-32 --- Interpretation using nomograms / Pages 33-47 --- Linear parameters / Pages 49-114 --- Non-linear parameters / Pages 115-173 --- Maximum likelihood and maximum entropy / Pages 175-193 --- Analytic inversion / Pages 195-211 --- Advanced inversion methods / Pages 213-227 --- Error analysis / Pages 229-243 --- Parallel computation in modelling and inversion / Pages 245-255

Description / Table of Contents: Pages 1-13 / Maars of the Westeifel, Germany / G. Büchel --- Pages 15-60 / Syn- and post-eruptive mechanism of the Alaskan Ukinrek Maars in 1977 / G. Büchel, V. Lorenz --- Pages 61-80 / Maars and maar lakes of the Westeifel Volcanic Field / Jörg F. W. Negendank, Bernd Zolitschka --- Pages 81-94 / Maars of northern Auvergne (Massif Central, France): State of knowledge / E. Juvigné, G. Camus, A. de Goër de Herve --- Pages 95-107 / Palaeoenvironmental investigations on long sediment cores from volcanic lakes of Lazio (central Italy)—An overview / Maria Follieri, Donatella Magri, Biancamaria Narcisi --- Pages 109-116 / Geophysical mapping of organic sediments / Stefan Wende, Reinhard Kirsch --- Pages 117-118 / Preliminary uniboom survey of the Monticchio Lakes (southern Italy) / A. Stefanon --- Pages 119-128 / Sonar investigations in the Laghi di Monticchio (Mt. Vúlture, Italy) / Ralph B. Hansen --- Pages 129-148 / Climatic and tectonic effects on sedimentation in central Italian volcano lakes (Latium)—Implications from high resolution seismic profiles / F. Niessen, A. Lami, P. Guilizzoni --- Pages 149-161 / Sediments and basin analysis of Lake Schalkenmehrener Maar / T. Heinz, B. Rein, J. F. W. Negendank --- Pages 163-171 / Organic carbon contents of sediments from Lake Schalkenmehrener Maar: A paleoclimate indicator / B. Rein, J. F. W. Negendank --- Pages 173-194 / Basin analysis for selected time-frames using sedimentation rates in Lake Meerfelder Maar (Westeifel FRG) / F. Wegner, J. F. W. Negendank --- Pages 195-208 / Turbidites in the sediments of Lake Meerfelder Maar (Germany) and the explanation of suspension sediments / D. Drohmann, J. F. W. Negendank --- Pages 209-222 / Paleoclimate reconstruction at the Pleistocene/Holocene transition—A varve dated microstratigraphic record from Lake Meerfelder Maar (Westeifel, Germany) / D. Poth, J. F. W. Negendank --- Pages 223-235 / Paleoenvironmental reconstruction of the Late- and Postglacial sedimentary record of Lake Weinfelder Maar / A. Brauer, J. F. W. Negendank --- Pages 237-275 / Sedimentology and paleoenvironment from the Maar Lac du Bouchet for the last climatic cycle, 0-120,000 years (Massif Central, France) / Elisabeth Truze, Kerry Kelts --- Pages 277-288 / Lago Grande di Monticchio (southern Italy) a high resolution sedimentary record of the last 70,000 years / Bernd Zolitschka, Jörg F. W. Negendank --- Pages 289-304 / A multidisciplinary study of the Vico Maar sequence (Latium, Italy): Part of the last cycle in the Mediterranean area. Preliminary results / P. Francus, S. Leroy, I. Mergeai, G. Seret, G. Wansard --- Pages 305-316 / Environmental geology and geochemistry of lake sediments (Holzmaar, Eifwl, Germany) / B. G. Lottermoser, R. Oberhänsli, B. Zolitschka, J. F. W. Negendank, U. Schütz… --- Pages 317-332 / Geochemistry of Lago Grande di Monticchio, S. Italy / C. Robinson, G. B. Shimmield, K. M. Creer --- Pages 333-348 / Tephrochronology of core C from Lago Grande di Monticchio / Anthony J. Newton, Andrew J. Dugmore --- Pages 349-365 / A palaeomagnetic study of maar-lake sediments from the Westeifel / B. Haverkamp, Th. Beuker --- Pages 367-376 / Preliminary 50m palaeomagnetic records from Lac du Bouchet, Haute Loire, France / T. Williams, K. M. Creer, N. Thouveny --- Pages 377-392 / Palaeomagnetic investigations of Lago Grande di Monticchio, southern Italy / Ian Turton --- Pages 393-420 / Late-Glacial/Holocene changes of the climatic and trophic conditions in three Eifel maar lakes, as indicated by faunal remains. I. Cladocera / Wolfgang Hofmann --- Pages 421-433 / Late-glacial/Holocene changes of the climatic and trophic conditions in three Eifel maar lakes, as indicated by faunal remains. II. Chironomidae (Diptera) / Wolfgang Hofmann --- Pages 435-439 / Ostracoda (Crustacea) and trichoptera (Insecta) from Late-and Postglacial sediments of some European maar lakes / Burkhard W. Scharf --- Pages 441-446 / Oligocence dinoflagellate-cysts in Quaternary freshwater sediments of Eifel maars / H. Weiler --- Pages 447-465 / Tertiary maars of the Hocheifel Volcanic Field, Germany / G. Büchel, M. Pirrung --- Pages 467-476 / Some aspects of Cenozoic maar sediments in Europe: the source-rock potential and their exceptionally good fossil preservation / W. Zimmerle --- Pages 477-484 / Palaeoecological implications from the sedimentary record of a subtropical maar lake (Eocene Eckfelder Maar; Germany) / Bernd Zolitschka --- Pages 485-489 / Arthropods from the Eocene Eckfelder Maar (Eifel, Germany) as a source for paleoecological information / H. Lutz --- Pages 491-497 / Flowers from the Middle Eocene of Eckfeld (Eifel, Germany)— First results / H. Frankenhäuser, V. Wilde --- Pages 499-503 / Initial results on the importance of a flora from the Middle Eocene of Eckfeld (Eifel, W.-Germany) / V. Wilde, H. Frankenhäuser --- Pages 505-509 / International Maar Deep Drilling Project (MDDP) a challenge for earth sciences? / Jörg F. W. Negendank, Bernd Zolitschka

Description / Table of Contents: PREFACE This book represents the first attempt in three decades to marshall out available information on the regional geology of Africa for advanced undergraduates and beginning graduate students. Geologic education in African universities is severely hampered by the lack of a textbook on African regional geology. This situation is greatly exacerbated by the inability of most African universities to purchase reference books and maintain journal subscriptions. Besides, geologic information about Africa is so widely dispersed that a balanced and comprehensive course content on Africa is beyond the routine preparation of lecture notes by university teachers. Since geology is a universal subject and Africa is one of the largest landmasses on Earth with one of the longest continuous records of Earth history, there is no doubt that geologic education in other parts of the world will benefit from a comprehensive presentation of African geologic case histories. The scope of this text also addresses the need of the professional geologist, who may require some general or background information about an unfamiliar African geologic region or age interval. Africa occupies a central position in the world's mineral raw materials trade. Because of its enormous extent and great geologic age, the diversity and size of Africa's mineral endowment is unparalleled. Africa is the leading source of gold, diamond, uranium, and dominates the world's supply of strategic minerals such as chromium, manganese, cobalt, and platinum. Consequently, African nations from Algeria to Zimbabwe depend solely on mineral exports for economic survival. The geologic factors which govern economic mineral deposits are stressed in this text. The geological history of Africa spans 3.8 billion years, a record that is unique both in duration and continuity. Few other parts of our planet match the plethora of geologic phenomena and processes that are displayed in the African continent. From the various stages of crustal evolution decipherable from the Archean of southern Africa, through the plate tectonics scenarios in the ubiquitous Late Proterozoic-Early Paleozoic Pan-African mobile belts and in the Hercynian and Alpine orogenies of northwest Africa, to the East African Rift Valley, Africa is replete with excellent examples and problems for a course on regional tectonics. Teachers of igneous and metamorphic petrology can hardly ignore Africa's anorogenic magmatism (e.g.. layered ultramafic intrusives such as the Great Dyke and the Bushveld Complex; the Tete gabbro-anorthosite pluton; alkaline complexes; basaltic volcanism), or tantalizing highgrade metamorphic terranes such as the Limpopo belt, the Namaqua mobile belt, and the Mozambique belt. From the extensive Precambrian supracrustal sequences throughout the continent with enormous thicknesses of sedimentary rocks that have hardly been deformed or metamorphosed, to the stratigraphic evolution of Africa's present-day passive continental margin, there is a complete spectrum of facies models upon which to base a course on basin analysis and stratigraphy. To maintain its integrity a course on historical geology anywhere in the world must address the theory of Continental Drift beyond invoking past continuities between West Africa and South America. Past connections between West Africa and eastern North America must equally be explored, so also connections between northeast Africa and Arabia, and the paleogeography of southern Gondwana where Africa occupied centre stage. The Precambrian fossil record, the transitions from reptiles to the earliest mammals and dinosaurs, and the evolution of Man are among Africa's unique contributions to the history of life and the story of organic evolution. Although it lies today in the tropics Africa was the theatre of the Earth's most-spectacular glaciations. Even after the scene of continental glaciation had shifted to the northern continents only lately during the Pleistocene, Africa still witnessed spectacular climatic fluctuations during the Quaternary. Certainly students of archeology and paleoanthropology cannot overlook the Quaternary paleoenvironmental record of the Olduvai Gorge in Tanzania, the Lake Turkana basin in Kenya, the Nile valley, the Sahara, and southern Africa. But since African examples have already been cited in standard geologic textbook, I have often been asked why it has become necessary to revive the idea of a full-length textbook on African geology, 30 years after this idea was abandoned by the geologic community. My simple answer, as already stated, is that the wealth of available geologic information about Africa is so enormous and fascinating, but so diffuse, that an attempt must be made to assemble and pass on this knowledge.

Description / Table of Contents: INTRODUCTION The International Summer School of Theoretical Geodesy on Satellite Altimetry in Geodesy and Oceanography was held in Trieste (Italy) from May 25 to June 6, igg2. It was organized by Prof. R. Rummel of the Delft University of Technology and by Prof. F. Sansò of the Politecnico di Milano and was attended by 63 participants and 7 lecturers from 17 countries. The School was hosted by the International Centre of Theoretical Physics of Trieste. Satellite altimetry provides a lot of data that require more and more sophisticated models in order to be interpreted and exploited. One of the main problems related to the practical treatment of the data can be summarized as follows: oceanographers would like to ask geodesists to compute precise orbits and a precise geoid in order to put into evidence the Sea Surface Topography that can be interpreted as an oceanographic signal related to currents and to several physical parameters; on the other hand, geodesists would like to ask oceanographers to a-priori determine the Sea Surface Topography, in order to be able to extract from the altimeter data the geoid and the orbit errors to be used in the gravity field modelling. The solution to this dilemma can only be found in a cooperative frame. An integrated model to be used for a single-step treatment of altimetry is probably far to be defined, so at present geodesists and oceanographers must cooperate to obtain step-wise and iterative modelling of the gravity field and of the oceanographic phenomena. This is precisely the reason why the school on Satellite Altimetry was organized on an interdisciplinary basis...