Structure and Evolution of the NE Atlantic Region and Links to the Arctic
Jan Inge Faleide1, Filippos Tsikalas3, Asbjørn J. Breivik1, Rolf Mjelde2, Olav A. Blaich1, and Olav Eldholm2
1Department of Geosciences, University of Oslo, Oslo, Norway.
2Department of Earth Science, University of Bergen, Bergen, Norway.
3Eni Norge AS, Stavanger, Norway.
The sedimentary basins at the conjugate continental margins off Norway and Greenland and in the western Barents Sea developed as a result of a series of post-Caledonian rift episodes until early Cenozoic time, when complete continental separation took place. Late Mesozoic-early Cenozoic rifting was related to the northward propagation of North Atlantic sea floor spreading, but also linked to important tectonic events in the Arctic. Prior to that, Late Paleozoic rift basins formed between Norway and Greenland and in the western Barents Sea along the NE-SW Caledonian trend. Late Jurassic-Early Cretaceous rifting was the dominant, composite tectonic episode which gave rise to prominent NE-trending structures in the NE Atlantic. Following rifting, a wide region subsided and was covered by thick Cretaceous strata. Aptian-?Albian rifting is documented locally off Mid-Norway, onshore East Greenland and in the SW Barents Sea. A distinct Late Cretaceous rift event is documented on the conjugate mid-Norway and East Greenland continental margins, and is characterised by large-scale normal faulting and locally by low-angle detachment faulting within thick Cretaceous strata. The extension between Greenland and Norway was taken up within the De Geer Zone by down-faulting in a pull-apart setting. The rifting culminated in crustal breakup and accretion of oceanic crust near the Paleocene-Eocene transition, accompanied by large-scale igneous activity associated with the North Atlantic Large Igneous Province. Passive rifted margins developed off mid-Norway and central East Greenland, and along the northern Barents Sea during opening of the Norwegian-Greenland Sea and Eurasia Basin, respectively. The western Barents Sea-Svalbard and NE Greenland margins developed as predominantly sheared margins. There is a well-defined along-strike margin segmentation and the various segments are characterized by distinct crustal properties, structural and magmatic styles, and post-opening history of vertical motion. The continent-ocean transition is confined within a narrow zone at the sheared margin segments, but is more obscure and partly masked by volcanics at the rifted margin segments. Following breakup, the subsiding margins experienced modest sedimentation until the late Pliocene when large wedges of glacial sediments prograded into the deep ocean from uplifted areas along the continental margins. The NE Atlantic margins were also affected by Cenozoic compressional deformation.
AAPG Search and Discover Article #90096©2009 AAPG 3-P Arctic Conference and Exhibition, Moscow, Russia