Thickness of Quaternary deposits and their relation to the pre-Quaternary in the Fennoscandian border zone in Kattegat and Vendsyssel

Refraction seismic measurements from Kattegat have been analysed for information about Quaternary deposits. Preliminary results show a gradual increase in thickness of the Quaternary deposits from about 50m in the SW to 150–250m in the NE, close to the Swedish coast. A number of narrow zones with extraordinarily great thickness are superimposed on this surface. Comparisons with structural features in the pre-Quaternary, as known from reflection seismic investigations, strongly indicate that the 'Kattegat Basin' is a structural phenomenon generated by subsidence under tensional stress perpendicular to the Fennoscandian border zone. Stratigraphical analysis which is available from wells on the islands in Kattegat and in Vendsyssel shows that subsidence of the 'Kattegat Basin' was initiated in Holstein or earlier.