Late Quaternary carbonate sedimentation and paleo-oceanography in the eastern Norwegian Sea |
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| Authors: | MOGENS RAMM |
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| Institution: | Department of Geology, University of Oslo, P. O. Box 1047 Blindern, N-0316 Oslo 3, Norway |
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| Abstract: | Four gravity cores from the eastern Norwegian Sea are studied. Absolute accumulation rates are quantified and variations in carbonate sedimentation and their implications for the paleo-oceanographic history of the Norwegian Sea are described. In the eastern Norwegian Sea, interglacial, ice-free conditions were developed during oxygen-isotope stages 1 and 5e. Open water conditions were probably the norm during the summer season, also during glacial stages. Slightly elevated summer temperatures in periods during isotope stages 2 and 7 are demonstrated by increased contents of subpolar planktic foraminifera. The deep waters of the eastern Norwegian Sea have been well oxygenated during most of the last 250,000 years. Organic-rich sediments and intensive carbonate dissolution in some parts of isotope stages 4 and 6 indicate corrosive bottom waters. A permanent ice cover and low saline surface waters, as found in the Arctic Ocean today, may have been developed in these periods. Well-preserved foraminiferal assemblages from stage 2 show more oxygenated bottom waters and more effective bottom water renewal in this period than during stage 3. |
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