The Initiation of Opening of the Norwegian Sea

• Main Authors: Talwani, M, Mutter, J, Eldholm, O
• Format: Article in Journal/Newspaper
• Language: English
• Published: Gauthier-Villars 1981
• Subjects: Lofoten; Lofoten Basin; Norwegian Sea
• Online Access: https://archimer.ifremer.fr/doc/00245/35669/34177.pdf; https://archimer.ifremer.fr/doc/00245/35669/

Multichannel seismic reflection profiling has revealed that the basalt layer on the Outer Voring Plateau is underlain in places by steeply dipping layered reflectors. Two opposing theories have been considered for the origin of the layered reflectors: (1) They are Mesozoic sediments deposited before the Tertiary opening of the Norwegian Sea. (2) They are Tertiary deposits formed during the early stage of opening of the Norwegian Sea by seafloor spreading. The authors find that: (a) magnetic anomaly 24 can be traced continuously from the Lofoten Basin on to the Voring Plateau, associated with the oldest seafloor generated in the opening of the Norwegian Sea; (b) the layered reflectors form a characteristically shaped wedge that coincides with anomaly 24; (c) the material comprising the wedge possesses seismic velocities which increase from about 2.6 km/sec. in the upper part to about 6.4 km/sec. in the lower part. The above observations strongly support a Tertiary age for the material comprising the wedge, which consists of basalic flows and volcanogenic sediments and which is associated with sea floor created a few million years after the start of spreading.