The geological structure of the western Barents Sea

Abstract

A large-scale geophysical reconnaissance survey has been carried out within the framework of the BGR project “Geoscientific research in the North Atlantic”. From these geophysical data and results obtained from other investigations, the western Barents Sea can be divided from west to east into the following geological units: 1. (1) A prograded sedimentary wedge. 2. (2) The N—S-running Senja Ridge, a structural high built-up of folded and faulted sediments. 3. (3) The Spitsbergen Platform, a flat-lying rock complex with high seismic velocities. 4. (4) The Tromsø Basin, a NNE-running fault-bounded basin with salt diapirs. 5. (5) The Bear Island Basin. 6. (6) The Transitional Unit, a zone subdivided in a western monoclinal structure and an eastern flat-lying sub-unit. 7. (7) The North Cape Basin, an ENE-running fault-bounded trough with salt diapirs. 8. (8) The Murmansk Basin, a basin adjoining the North Cape Basin in the East. During the Tertiary and up to the Quarternary the western Barents Sea was above sea level and acted as the source area for the Cenozoic sedimentary wedge situated west of 17° E. The often-observed refractor with a seismic velocity of about 5.5 km/sec interpreted as Caledonian basement by previous investigators represents Paleozoic sediments in large parts of the western Barents Sea.