Download or read book Reconstruction of Late Quaternary Sedimentary Environments at the Southern Mendeleev Ridge Artic Ocean written by Evgenia A. Bazhenova and published by . This book was released on 2012 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reconstruction of Late Quaternary Sedimentary Environments at the Southern Mendeleev Ridge Artic Ocean written by Evgenia A. Bazhenova and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The First Late Quaternary Sediment Record from the Western Arctic Ocean with a True Millennial Resolution written by Ruth Adler and published by . This book was released on 2008 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Sediment core HLY0503-08JPC, collected on the HOTRAX'05 expedition, has been sampled in the upper 5 m and reveals a cyclicity that encompasses marine isotope stages (MIS) 1-6, with more detail than seen in other cores from the central Arctic Ocean. Age control is provided by Accelerator Mass Spectrometry 14C and amino acid racemization ages and comparison of other cores with established chronostratigraphy. Cyclic changes in foraminiferal abundance, [delta]18O and [delta]13C values of planktonic foraminifer Neogloboquadrina pachyderma (sinistral) and lithologic variations reflect changes in circulation and depositional environments. Overall, the HLY0503-08JPC record provides the most detailed analysis of Late Quaternary environments in the western Arctic Ocean available to date and strengthens the age model for Arctic Ocean Quaternary stratigraphy.
Download or read book Arctic Ocean Sediments Processes Proxies and Paleoenvironment written by R. Stein and published by Elsevier. This book was released on 2008-07-22 with total page 607 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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
Download or read book Multi Disciplinary Applications in Magnetic Chronostratigraphy written by Kenneth Philip Kodama and published by Frontiers Media SA. This book was released on 2021-03-04 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Glacial Marine Sedimentation written by Bruce F. Molnia and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 843 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume of 18 papers describes the glacial-marine sedimentary environment in a variety of temporal and spatial settings. The volume's primary emphasis is the characteri zation of Quaternary glacial-marine sedimentation to show (1) the significant differences that exist between glacial marine environments in different geographic settings and (2) their resulting glacial-marine deposits and facies. Addi tionally, papers describing ancient glacial-marine environ ments are also presented to illustrate lithified analogs of the Quaternary deposits. With the Doctrine of Uniformitarianism in mind (the present is the key to the past), it is hoped that this volume will serve to expand the horizons of geologists working on the rock record, especially those whose primary criteria for recognition of ancient glacial-marine environments is the presence of dropstones in a finer-grained matrix. As the papers presented here show, diamictite is only one of many types of deposits that form in the glacial-marine sedimentary environment. Papers presented in this volume examine the Quaternary glacia1-marine sedimentary picture in subarctic Alaska, Antarctica, the Arctic Ocean, the Kane Basin, Baffin Island, the Puget-Fraser Lowland of Washington and British Columbia, and the North Atlantic Ocean. Ancient glacia1-marine depos its described are the Neogene Yakataga Formation of southern Alaska, the Late Paleozoic Dwyka Formation of the Karoo Basin of South Africa, and the Precambrian Mineral Fork Formation of Utah. For continuity, a paper summar1z1ng the temporal and spatial occurrences of glacial-marine deposits is also presented.
Download or read book Reconstruction of Quaternary Paleo circulation in the Western Arctic Ocean Based on a Neodymium Isotope Record from the Northwind Ridge written by Rachael E. Gray and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: An understanding of past ocean circulation in the Arctic is critical for interpretations of past global ocean and atmospheric circulation, as well as predictions of future conditions. The Arctic Ocean plays a major role in global climate, due to its contributions to both the North Atlantic Deep Water (and subsequently the Atlantic Meridional Overturning Circulation) and the planet's albedo (due to sea ice cover). A sediment core from the Northwind Ridge in the western Arctic Ocean, ~800 km north of Alaska, has been sampled for measurement of radiogenic isotope ratios of neodymium and strontium. Sediment grain coatings were leached from the bulk sediment and measured for 87/86Sr and [epsilon]Nd, a proxy for seawater source. Two leaching solutions, one using buffered acetic acid and the second using hydroxylamine hydrochloride, were applied to sediments. Strontium data suggests that acetic acid best captures the seawater signal, while hydroxylamine hydrochloride leaching likely caused clay contamination of the hydrogenous data. [epsilon]Nd ratios were compared with independent lithologic proxies measured on the core and with results of earlier radiogenic-isotope studies in the Arctic Ocean. Data obtained suggest that radiogenic waters dominated the western Arctic Ocean during the estimated Early Pleistocene, probably due to increased Pacific water inputs and/or enhanced brine exclusion from sea ice formation on the Siberian shelves. These conditions likely indicate relatively warm climatic environments with predominantly seasonal sea ice, and thus can be potentially used as a paleo-analog for the projected near-future state of the Arctic. Further upcore, in the estimated Middle to Late Pleistocene, [epsilon]Nd values decrease overall, with high-amplitude fluctuations corresponding to glacial-interglacial cyclicity. Strongly non-radiogenic values in glacial intervals suggest the predominance of inputs from the Canadian Shield eroded by the Laurentide ice sheet. More radiogenic but gradually decreasing interglacial values indicate a change from Pacific to Atlantic water influence during the Middle to Late Pleistocene. Further isotope work on other cores may clarify the mechanisms and extent of this shift in circulation patterns.
Download or read book The Quaternary Stratigraphy of the Northwind Ridge Arctic Ocean written by Kevin Allen Crawford and published by . This book was released on 2010 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The Arctic Ocean plays an important role in modulating the world's climate. Changes in sea-ice albedo and the export of freshwater into the North Atlantic could have serious repercussions to the climate patterns far beyond the Arctic. To understand fully the impacts of the retreating sea-ice cover and the warming Arctic Ocean we need to look into the past for clues. Paleoenvironments of the Arctic Ocean can be reconstructed by using sea-floor sediment constituents, such as paleobiological and mineral components as well as chemical and paleomagnetic parameters. Three cores raised from the Northwind Ridge, north of the Alaskan continental margin, were chosen to investigate sedimentary patterns and related paleoenvironments in the western Arctic Ocean across a time frame from the Holocene to estimated early Pleistocene. These cores show a range of sedimentation rates decreasing from south to north, thus allowing a development of a relatively high-resolution Upper Quaternary stratigraphy at the southern part of the ridge and a lower-resolution, yet longer stratigraphy for its northern part. In addition to this long stratigraphic coverage, the northern core has well-preserved calcareous microfauna, which provides new insights into paleoceanographic environments. All stratigraphic intervals recovered display glacial-interglacial cyclicity expressed in abundances of foraminifera and ice-rafted debris, and variability in stable-isotopic compositions and some chemical elements such as manganese consistent with data from other parts of the Arctic Ocean. In addition to this cyclicity, sedimentary and micropaleontological data from cores under study indicate a step increase in glacial inputs and sea-ice coverage at the end of the Early Pleistocene, co-occurring with a fundamental reorganization of the Earth's climate during the Mid-Pleistocene Transition. The causal relationships between these processes are yet to be investigated.
Download or read book Late quaternary Arctic Ocean sediment records written by Niels Nørgaard-Pedersen and published by . This book was released on 1997 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reconstruction of Late Quaternary Paleoceanography of the Red Sea written by Amani Badawi and published by . This book was released on 2003 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Late Quaternary History of the Northern North Sea written by Johan Hendrik Frederik Jansen and published by . This book was released on 1979 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Late Quaternary Paleoclimatic Reconstructions Along the Eurasian Continental Margin written by Hans Peter Kleiber and published by . This book was released on 2000 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Late Quaternary Sedimentary Environments in the Voidomatis Basin Northwest Greece written by Jamie C. Woodward and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Late Quaternary Sedimentation and Paleoceanography in the Eastern Arctic Ocean written by Berit Markussen and published by . This book was released on 1987 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Late Quaternary Sedimentation on the Mid Atlantic Reykjanes Ridge written by B. Gehrke and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Glacial Marine Sedimentation written by Bruce F Molnia and published by . This book was released on 1983-11-01 with total page 856 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Late Quaternary Depositional Environments Timing and Recent Deposition written by Bryan Andrew.. Oakley and published by . This book was released on 2012 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt:
