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A REGIONAL GRAVITY STUDY OF THE NORTHERN NORTH SEA (56–62° N)*

1985; Wiley; Volume: 33; Issue: 4 Linguagem: Inglês

10.1111/j.1365-2478.1985.tb00767.x

1365-2478

J. Hospers, Erik G. Finnstrøm, J.S. Rathore,

Geomagnetism and Paleomagnetism Studies

A bstract A Bouguer gravity anomaly map is presented of the North Sea and adjacent land areas in Norway and Denmark, covering an area situated between 56° and 62°N, 1°W and 10°E. The gravity data from the UK sector of the North Sea, the land and offshore areas of Denmark, and the land areas of Norway have been published before. However, the gravity data from the Norwegian sector of the North Sea are new. A large number (about 60) of individual gravity features can be defined in the mapped area. Most of those situated in the UK sector of the North Sea and on land in Norway have been discussed earlier; however, most of the anomalies found elsewhere which are qualitatively interpreted here have not been discussed before. An interpreted Bouguer anomaly map is presented which identifies all these features. The majority of the gravity anomalies encountered in the mapped area can be shown to be associated with one of the following geological features: (i) basement highs, (ii) large bodies of heavy basic or ultrabasic rock in the crystalline basement, (iii) large igneous intrusions within the sedimentary column and thick accumulations of volcanic rocks or their associated eruption centers, (iv) major basement faults. Large‐scale geological structures such as the Central, Viking and Sogn Grabens and the East Shetland, Stord, Forth Approaches and Norwegian‐Danish Basins are essentially in isostatic equilibrium and are only locally marked by relatively weak gravity minima. A residual gravity anomaly map has been produced by subtracting from the observed Bouguer anomalies the estimated gravity effect of an assumed thinned crust. This residual gravity anomaly map shows a number of features of the Bouguer anomaly field with greater clarity.