36. THE PALEOCEANOGRAPHIC HISTORY OF THE NORTH ATLANTIC-ARCTIC GATEWAYS: SYNTHESIS OF THE LEG 151 DRILLING RESULTS1
During Leg 151, seven locations were drilled in the western Norwegian-Greenland Sea, in Fram Strait, and on the Yermak Plateau. These sites allow us to address the paleoceanographic and climatic history of the surface- and bottom-water masses in high Northern Hemisphere deep-sea basins, of the mode...
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.463.9800 http://www-odp.tamu.edu/publications/151_SR/VOLUME/CHAPTERS/sr151_36.pdf |
| Summary: | During Leg 151, seven locations were drilled in the western Norwegian-Greenland Sea, in Fram Strait, and on the Yermak Plateau. These sites allow us to address the paleoceanographic and climatic history of the surface- and bottom-water masses in high Northern Hemisphere deep-sea basins, of the mode and pattern of water exchange between the Arctic Ocean and the Nor-wegian-Greenland Sea through Fram Strait, and the Neogene and Quaternary history of glaciation of the surrounding shelves and land regions. A detailed and well-developed pelagic biochronology has been defined for all of the sites, allowing correla-tion of their stratigraphic record to sedimentary sequences from lower latitudes. Except for a few short-lived interruptions caused by hiatuses, the entire paleoceanographic history from the Eocene, when the Norwegian-Greenland Sea was small and narrow, to the Quaternary can be described. When the Norwegian-Greenland Sea was small and consisted of a sequence of narrow basins, surface water penetrated the area from the North Atlantic Ocean and brought temperate to subtropical siliceous faunas and floras. Only during the latter part of the Oligocene and the early part of the Miocene did cool to temperate water develop. The first signs of marine ice covers or the presence of icebergs developed during the late Miocene, earlier on the Iceland Plateau, later in the northern and eastern part of the investigated region. The influence of the marine ice covers and of the influx of icebergs, first from Greenland and later from northwestern Europe, increased during the course of the Pliocene until it reached an important threshold approximately 3 |
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