Investigation of the Quaternary sediments of the southeast Baffin Island continental shelf using acoustic data supplemented by sample controls (grabs and cores).
The focus of this book is on oceanic climate change during the last deglaciation period and the high temporal resolution that can be obtained from sediment records at continental margin sites. The book draws together papers from the north-eastern North American continental margin with those from the north-west European Arctic and the Arctic and North Atlantic Oceans.
First published in 1985, Quaternary Environments represents the culmination of Quaternary research in the region of Baffin Island, Baffin Bay and West Greenland over a period of twenty years and it will serve as a timely and complementary balance to the paleo- oceanographic studies in the NE North Atlantic. The region of Baffin Island, Baffin Bay and West Greenland is probably the best place in the world to examine the interactions between ice, land and oceans on timescales of a few hundred to many thousands of years. Two introductory chapters outline the history of research and the physical background. In Part II the evidence for glacial erosion and deposition over the eastern Canadian Arctic is examined and the history of the Baffin Island continental shelf is described. Part III deals with the paleo- oceanography of Baffin Bay and the Labrador Sea through an examination of deep-sea cores dated by several different methods. In Part IV there is a comprehensive account of the stratigraphy of Baffin Island, Bylot Island, and West Greenland, from the Pliocene to the late Wisconsin. Part V examines the climatic effects of the past 10,000 years, considering evidence from pollen analysis, glacier fluctuations, changes of sea level and the response of early (Eskimo) man. This important volume will interest all quaternary scientists, especially those in glaciology, glacial geology, marine geology, and geomorphology.
Late Cenozoic glaciation directly affected sedimentation on more than half the Earth's continental shelves. Ice continues to be a dominant influence on sedimentation around Greenland and Antarctica, and on the shelves facing the Arctic Ocean. The features of these shelves include true glacimarine features, i.e. those found in a marine environment in proximityto, or strongly under the influence of, ice, such as iceberg scours and pits, ice gouges and incisions, subglacial outwash deposits, and diamictons resulting from ice rafting. Also seen, because large areas of the shelves were exposed during the Pleistocene lowering of sea level, are terrestrial glacial and periglacial features, e.g. fluvial outwash valleys and associated deposits, tunnel valleys, drumlin fields and lodgement till, which have subsequently been submerged and modified by marine influences. Glaciated Continental Margins: An Atlas of Acoustic Images illustrates the complexity of features found in glaciated and formerly glaciated marine environments. The volume was assembled by an international Editorial Committee, led by Thomas A. Davies (University of Texas), from records gathered in the course of recent research and contributed by members of the scientific community from around the world. These include seismic sections, side-scan maps, and 3-D seismic data, supplemented in some cases by bottom photographs and core data, with accompanying text. The work is scientists at 40 institutions in 10 countries is represented. This book will be an invaluable resource for students, Quaternary scientists, glaciologists, marine geologists and geophysicists, geotechnical engineers, and surveyors teachers working in universities, research institutions and government agencies with interests in polar and subpolar regions, as well as those in industries with offshore interests.
by K. Lambeck, R. Sabadini and E. B08Chi Viscosity is one of the important material properties of the Earth, controlling tectonic and dynamic processes such as mantle convection, isostasy, and glacial rebound. Yet it remains a poorly resolved parameter and basic questions such as whether the planet's response to loading is linear or non-linear, or what are its depth and lateral variations remain uncertain. Part of the answer to such questions lies in laboratory observations of the rheology of terrestrial materials. But the extrapolation of such measurements from the laboratory environment to the geological environment is a hazardous and vexing undertaking, for neither the time scales nor the strain rates characterizing the geological processes can be reproduced in the laboratory. General rules for this extrapolation are that if deformation is observed in the laboratory at a particular temperature, deformation in geological environments will occur at a much reduced temperature, and that if at laboratory strain rates a particular deformation mechanism dominates over all others, the relative importance of possible mechanisms may be quite different at the geologically encountered strain rates. Hence experimental results are little more than guidelines as to how the Earth may respond to forces on long time scales.
Understanding the ebb and flow of materials on the earth's surface is vital to comprehending environmental change. We need to differentiate between those that represent a progression of natural events from those that might be human induced. The latter can be managed by changing policies; the former probably cannot. This volume presents what researchers know and do not know about the base (or natural) level of surficial fluxes and their dynamics. Leading experts in the field offer a historical perspective on geofluxes and discuss the cycles of materials on the earth's surface, from weathering processes to the movement of material through the river system and oceans to their deposition. The committee sets research directions in five areas: shallow-water studies, mapping, rates of change, sample dating, andâ€"most criticalâ€"understanding whether human influence can exceed the natural variability in geoflux processes. This volume will be important reading for geophysical scientists, researchers, faculty, and students, as well as environmental policymakers.