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Alfred Wegener Institute for Polar and Marine Research, Postfach 120161, D-27515 Bremerhaven, Germany
1 Fachbereich Geowissenschaften/Universität Bremen, Postfach 330 440 D-28334 Bremen, Germany
Two land/sea seismic refraction experiments were carried out by the Alfred Wegener Institute in 1990 and 1992 to increase the understanding of the crustal structure of the volcanic passive margin in the eastern Weddell Sea off Dronning Maud Land. Four profiles were measured, two parallel to the margin between 12°W and 4°W and two perpendicular at 8°W. These data are the first seismic velocity measurements obtained for the entire crust offshore Dronning Maud Land. The interpretations of the seismic sections reveal velocity distributions which are typical of continental crust at volcanic passive margins. The lower crust exhibits velocities up to 7.5 km s–1, which indicates magmatic intrusions or underplating. The basement is overlain by the volcanic extrusions of the Explora Wedge, which has a maximum thickness of 8 km. The crust thins northwards from 40 km thickness near the ice edge to less than 25 km. Because of the velocity distribution in the crust and the assumption that the continental margin was created above a mantle plume, the margin can be regarded as an analogue of the continental margin in the North Atlantic (East Greenland and Vøring Margin).
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