Geological Structure And History Of The Arctic Ocean

This book contains the most complete description of the geologic and geophysical data of the structure of Arctic Basin including structures of the earth’s crust, crustal and acoustic basement, and sedimentary cover. The book includes information about extracted and studied cores and samples; observed, processed and interpreted data on geophysical anomalies and different conceptions, and a hypotheses of the origin of the modern Arctic Basin structures. Progress in solving the problems of the Arctic Basin geology is presented in the chapters and include contributions from leading field experts.

Proceedings of the NATO Advanced Research Workshop, Bremen, Germany, October 10-14, 1988

This trip backward in time capsulizes in a general way the geologic development of the area that is now northern Alaska. The Cretaceous through Recent history is predominantly one of erosion of the ancient Brooks Range and filling of the Colville Geosyncline under processes like those in Operation today. All the rocks older than Jurassic, however, were deposited far from their present sites. One of the intriguing tectonic puzzles involves the geographic positions and relative timing of events that occurred during the orogeny that built the Brooks Range. I suggest that pre-Cretaceous deposition took place far to the north along the western margin of the Caledonides. Subsequently, the region that is now northern Alaska moved southward and impinged upon a northward moving plate, or plates, from the Pacific region. Interactions between these two major parts of the earth's crust produced the Brooks Range during the Jurassic. Later developments reflect continuing readjustments of the northern third of of thrust Alaska as southward movement was dissipated in diverse systems faulting and lateral displacement. ACKNOWLEDGMENTS I am indebted to many colleagues who, during the past 30 years, shared with me the excitement and pleasures of exploring the geology of northern Alaska. Among these are W. P. Brosge, H. N. Reiser, R. L. Detterman, A. K. Armstrong, A. L. Bowsher, E. G. Sable, I. L. Tailleur, C. G. Mull, M. D. Mangus, A. H. Lachenbruch, M. C. Lachenbruch, R. L. Morris, C. J.

The 5-year Circum-Arctic Lithosphere Evolution (CALE) program developed new constraints on the tectonic history of the central Amerasia basin of the Arctic Ocean. This volume is the final synthesis of the CALE program, which brought together an international team of scientists to develop integrated, multi-disciplinary understanding of the region. This approach, based on the integration of much new geological and geophysical data from onshore and offshore , is necessary to advance our understanding of this basin. Regional onshore-to-offshore transects are central to the 18 papers in this volume. The diverse science supporting these crust-to-mantle regional transects includes structural, geochronological, isotopic, potential fields, and seismic reflection and refraction data. Four chapters present circum-Arctic investigations by the regional CALE teams. The final chapter addresses pan-Arctic themes. This unique collaboration, relying on new data and new syntheses of existing data sheds new light on the history of the Arctic Ocean.

Lorsqu'il n'est pas en notre pouvoir de discerner les plus vraies opinions, nous devons suivre les plus pro babies.-Rene Descartes When, in the early 1960's I undertook to covered, due to limitations imposed by a single study Arctic Ocean deep-sea cores, I did not volume. anticipate that 10 years later the climatic history Although not comprehensive, it is hoped that of the north polar basin would be still a matter of this book will provide an insight into the current debate. Although much new data have accumu status of Arctic research and will also serve as a lated in various fields of Arct.

There is broad agreement in the scientific community that the floor of the Arctic Ocean Basin contains potential answers to major unsolved problems in the earth sciences and that many of them pertain to questions that are of global scientific significance or pressing societal concern. However, because of the perennial sea ice, harsh climate, high field costs, and the absence of research platforms suitable for many types of investigations, this region is also one of the most poorly known on earth. Recent political and technological developments, including the apparent end of the Cold War and the prospective availability of nuclear submarines and powerful icebreakers as arctic research platforms, appear to provide possible means to overcome these formidable obstacles and, therefore, have the potential to enable revolutionizing our knowledge of the solid earth beneath the Arctic Ocean Basin. Some of the details of the circum-arctic geology are becoming known from efforts by government agencies, academic institutions, and industry. Because of the prospective logistic opportunities, and because of the disparity in geologic understanding that exists between the Arctic Ocean Basin and the circum-arctic landmasses, the Committee on Arctic Solid-Earth Geosciences recommends that the Arctic Ocean Basin and its margins, instead of the circum-arctic landmasses, be the focus of the next major augmentation of solid-earth geoscience research in the Arctic.

Sea ice, which covers up to 7% of the planet’s surface, is a major component of the world’s oceans, partly driving ocean circulation and global climate patterns. It provides a habitat for a rich diversity of marine organisms, and is an extremely valuable source of information in studies of global climate change and the evolution of present day life forms. Increasingly sea ice is being used as a proxy for extraterrestrial ice covered systems. Sea Ice provides a comprehensive review of our current available knowledge of polar pack ice, the study of which is severely constrained by the logistic difficulties of working in such harsh and remote regions of the earth. The book’s editors, Drs Thomas and Dieckmann have drawn together an impressive group of international contributing authors, providing a well-edited and integrated volume, which will stand for many years as the standard work on the subject. Contents of the book include details of the growth, microstructure and properties of sea ice, large-scale variations in thickness and characteristics, its primary production, micro-and macrobiology, sea ice as a habitat for birds and mammals, sea ice biogeochemistry, particulate flux, and the distribution and significance of palaeo sea ice. Sea Ice is an essential purchase for oceanographers and marine scientists, environmental scientists, biologists, geochemists and geologists. All those involved in the study of global climate change will find this book to contain a wealth of important information. All libraries in universities and research establishments where these subjects are studied and taught will need multiple copies on their shelves. David Thomas is at the School of Ocean Sciences, University of Wales, Bangor, UK. Gerhard Dieckmann is at the Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany

Although it is generally accepted that the Arctic Ocean is a very sensitive and important region for changes in the global climate, this region is the last major physiographic province of the earth whose short-and long-term geological history is much less known in comparison to other ocean regions. This lack of knowledge is mainly caused by the major technological/logistic problems in reaching this harsh, ice-covered region with normal research vessels and in retrieving long and undisturbed sediment cores. During the the last about 20 years, however, several international and multidisciplinary ship expeditions, including the first scientific drilling on Lomonosov Ridge in 2004, a break-through in Arctic research, were carried out into the central Artic and its surrounding shelf seas. Results from these expeditions have greatly advanced our knowledge on Arctic Ocean paleoenvironments. Published syntheses about the knowledge on Arctic Ocean geology, on the other hand, are based on data available prior to 1990. A comprehensive compilation of data on Arctic Ocean paleoenvironment and its short-and long-term variability based on the huge amount of new data including the ACEX drilling data, has not been available yet. With this book, presenting (1) detailed information on glacio-marine sedimentary processes and geological proxies used for paleoenvironmental reconstructions, and (2) detailed geological data on modern environments, Quaternary variability on different time scales as well as the long-term climate history during Mesozoic-Tertiary times, this gap in knowledge will be filled. *Aimed at specialists and graduates *Presents background research, recent developments, and future trends *Written by a leading scholar and industry expert