Glaciated Continental Margins

Glaciated Continental Margins
Author: Thomas A. Davies
Publisher: Springer Science & Business Media
Total Pages: 447
Release: 2012-12-06
Genre: Science
ISBN: 9401158207

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.

Glaciated Margins

Glaciated Margins
Author: D.P. Le Heron
Publisher: Geological Society of London
Total Pages: 289
Release: 2019-04-08
Genre: Science
ISBN: 1786203979

Understanding the sedimentary and geophysical archive of glaciated margins is a complex task that requires integration and analysis of disparate sedimentological and geophysical data. Their analysis is vital for understanding the dynamics of past ice sheets and how they interact with their neighbouring marine basins, on timescales that cannot be captured by observations of the cryosphere today. As resources, sediments deposited on the inner margins of glaciated shelves also exhibit resource potential where more sand-dominated systems occur, acting as reservoirs for both hydrocarbons and water. This book surveys the full gamut of glaciated margins, from deep time (Neoproterozoic, Ordovician and Carboniferous–Permian) to modern high-latitude margins in Canada and Antarctica. This collection of papers is the first attempt to deliberately do this, allowing not only the similarities and differences between modern and ancient glaciated margins to be explored, but also the wide spectrum of their mechanisms of investigation to be probed. Together, these papers offer a high-resolution, spatially and temporally diverse blueprint of the depositional processes, ice sheet dynamics, and basin architectures of the world’s former glaciated margins; a vital resource in advancing understanding of our present and future marine-terminating ice sheet margins.

Depositional Successions on Glaciated Continental Margins [microform] : the Cenozoic of Antarctica and the Neoproterozoic of Rodinia

Depositional Successions on Glaciated Continental Margins [microform] : the Cenozoic of Antarctica and the Neoproterozoic of Rodinia
Author: Nicole N. (Nicole Naomi) Januszczak
Publisher: National Library of Canada = Bibliothèque nationale du Canada
Total Pages: 956
Release: 2004
Genre:
ISBN: 9780612917453

Part II of this thesis focuses on the sedimentological and stratigraphic evidence for glaciation in the Neoproterozoic. Integrating this analysis with a recent understanding of the tectonic setting of Neoproterozoic sedimentary basins provides a basis for an alternative 'zipper-rift' hypothesis for Neoproterozoic glaciations. The 'zipper-rift' model emphasizes a strong linkage between the first-order reorganisation of the Earth's surface created by rifting of Rodinia, the climatic effects of uplifted rift flanks and the resulting sedimentary record deposited in newly formed rift basins. Neoproterozoic glaciation was regional in extent, strongly controlled by tectonics and diachronous in its timing as Rodinia progressively broke apart over some 150 million years. This thesis is presented in two parts. The first half deals with the Cenozoic glacial record of Antarctica and the second half focuses on the Neoproterozoic glacial record of Rodinia. The glacially-influenced Cenozoic continental margin of Antarctica shows a large-scale subsurface seismic stratigraphy consisting of flat-lying 'topsets' recording episodic aggradation of the continental shelf, that rest on seaward-dipping, wedge-shaped 'foresets' formed by the progradation of the continental slope. Strata from topsets record aggradation by till deposition alternating with glacial-marine sedimentation. Strata from foresets record debris flows and turbidity currents on an active slope close to a source of poorly-sorted glacial debris such as an ice sheet margin reaching the shelf break. The original intention at the commencement of the thesis was to use depositional models derived from Antarctica as 'modern' analogues for Neoproterozoic successions. Critical evaluation of Neoproterozoic successions shows that many are not glacial in origin. Many Neoproterozoic 'glacial' successions have been identified as glacial on the basis of the presence of diamictite facies. Diamictite facies are commonly present within thick turbidite successions and are the product of active rifting and the shedding of poorly sorted debris into rapidly subsiding marine rift basins. The sedimentary record from the continental shelf of Prydz Bay, East Antarctica was examined by Ocean Drilling Program Leg 188. This record constrains the onset of glaciation in Antarctica to the late Eocene (c. 39 Ma) and records an important interval in the history of Antarctica, capturing for the first time the transition from a warmer preglacial climate, through early-glacial, and culminating in continental-scale glaciation of Antarctica.

Continental Rifted Margins 2

Continental Rifted Margins 2
Author: Gwenn Peron-Pinvidic
Publisher: John Wiley & Sons
Total Pages: 258
Release: 2022-05-23
Genre: Science
ISBN: 111998694X

Rifted margins mark the transition between continents and oceans, which are the two first-order types of land masses on Earth. Rifted margins contribute to our understanding of lithospheric extensional processes and are studied by various disciplines of Earth Science (geology, geophysics, geochemistry). Thanks to better and wider public access to high-quality data, our understanding in these areas has improved significantly over these last two decades. This book summarizes this knowledge evolution and details where we stand today, with a series of case examples included. It is structured in a practical way, with concise text descriptions and comprehensive diagrams. Continental Rifted Margins 2 is a useful resource for students and newcomers to the rifted margin community – a "cookbook” of sorts to facilitate the reading of scientific publications and provide basic definitions and explanations.

Margins

Margins
Author: National Research Council
Publisher: National Academies Press
Total Pages: 296
Release: 1990-02-01
Genre: Science
ISBN: 0309041880

Approximately 70 percent of the world's population is concentrated in the coastal borderlands, which geologists recognize to be the present continental margins. This new book on these continental margins provides a detailed account of a meeting which brought together specialists in marine and terrestrial geology, geochemistry, and geophysics. The workshop garnered widespread support and enthusiasm for a new direction in margins research focused on interdisciplinary studies of the fundamental processes of continental margin evolution. Scientific problems and solutions were identified for both divergent and convergent margins. Results of the workshop show that many of the fundamental plate interaction processes are common to all margins, whether formed by extension, contraction, or translation. This conclusion suggests a unified approach to margins research. A margins initiative has been proposed to follow up on the workshop results by developing science programs aimed at understanding the processes that control the initiation and evolution of continental margins.

Continental Margins

Continental Margins
Author: National Research Council (U.S.). Ad Hoc Panel to Investigate the Geological and Geophysical Research Needs and Problems of Continental Margins
Publisher:
Total Pages: 332
Release: 1979
Genre: Science
ISBN:

Non-volcanic Rifting of Continental Margins

Non-volcanic Rifting of Continental Margins
Author: Geological Society of London
Publisher: Geological Society of London
Total Pages: 598
Release: 2001
Genre: Science
ISBN: 9781862390911

Non-continental margins lack thick lavas that are generated as continental crust thins immediately prior to the onset of seafloor spreading. They may form up to 30 per cent of passive margins around the world. This volume contains papers examining an active margin, fossil margins that border present day oceans, and remnants of margins exposed today in the Alps. The papers present evidence across a range of scales, from individual mineral grains, through borelide cores and outcrop, to whole margins at the crustal scale.