First Break - Volume 15, Issue 12, 1997

Meeting with Anton Ziolkowski in the calm of his professorial room at Edinburgh University, you get a strong sense of someone who has unfinished business with the oil industry and the geophysics community in particular. Andrew McBarnet reports on a recent conversation.

A number of events in the last month or so have signalled what could be a significant breakthrough in the progress of international oil exploitation in Russia and other republics in the former Soviet Union, particularly in the troubled Caspian Sea area. Andrew McBarnet reports.

Major international strategic and commercial interests (highlighted by the speakers' panel at this year's EAGE Conference General Session in Geneva earlier this year) continue to wreath the future of the Caspian Sea region's hydrocarbons riches in a cloud of uncertainty.

The aim of this paper is to present an integrated geophysical study of the pre-Zechstein geology in the south-eastern North Sea, offshore Denmark (Fig. 1). Main tectonic features of the area include the Central Graben in the west, the Horn Graben in the south-east, the East North Sea High in the middle, the Holmsland Block in the east, the southern part of the Norwegian-Danish Basin in the north, as well as the northern part of the North German Basin in the south (Fig. 2). The central part of the study area (i.e. East North Sea High) is commonly regarded as part of the Ringk˘bing-Fyn High, which is a major NWW±ESE trending positive structural element with a relatively thin cover of Mesozoic and Tertiary sediments. This structural high divides the North German Basin from the Norwegian-Danish Basin. The main tectonic features in the area are clearly illustrated by the depth structure of the top pre-Zechstein (base Upper Permian) rock (Fig. 3a). In this study, geophysical evidence is presented to show the existence of substantial amounts of Palaeozoic sediments in the area of the East North Sea High. The interpretation is based on a residual gravity anomaly map of the region, which outlines the potential area of Palaeozoic sediments as indicated by relatively low residual gravity anomalies. Magnetic basement depths of a few selected areas are estimated using available aeromagnetic data. Interpretation of selected seismic sections is carried out to confirm the results derived from the potential field investigations. Finally, the implications of the finding of this study are discussed briefly in terms of the pre-Zechstein geology and the tectonic history of the region as well as its potential relevance to petroleum exploration in the area.