73-102－Late Palaeozoic structural development of the South-western Barents Sea.pdf

Marine and
Petroleum Geology
ELSEVIER Marine and Petroleum Geology 15 (1998) 73 102
Late Palaeozoic structural development of the South-western
Barents Sea
S. T. Gudlaugsson *'l, J. I. Faleide, S. E. Johansen 2, A. J. Breivik
Department of Geology, UniversiO' of Oslo, . Box 1047 Blindern, N-0316 Oslo, Norway
Received 27 November 1995; revised 14 August 1997; accepted 30 August 1997
Abstract
A regional grid of multichannel seismic reflection profiles records the Late Palaeozoic structure and tectonic development of the
south-western Barents Sea. A 300 km wide rift zone, extending at least 600 km in a north-easterly direction, was formed mainly
during Middle Carboniferous times. The rift zone was a direct continuation of the north-east Atlantic rift between Greenland and
Norway, but a subordinate tectonic link to the Arctic rift was also established. The overall structure of the rift zone is a fan-shaped
array of rift basins and intrabasinal highs with orientations ranging from north-easterly in the main rift zone to northerly at the
present western continental margin. The structural style is one of interconnected and segmented basins characterized by halfgraben
geometries. A less prominent north-westerly fault trend abuts against the main rift zone from the south-east. From the beginning of
Late Carboniferous times, the tectonic development was dominated by regional subsidence, and the entire Barents Sea region
gradually became part of a huge Permian-Triassic interior sag basin. This development was interrupted by renewed Permian Early
Triassic rifting and formation of north trending structures in the western part of the rift zone. The tectonic link between the north-
east Atlantic and Arctic rifts, initiated in the Middle Carboniferous, then became the primary locus of deformation. The tectonic
relationship of north-east Atlantic-Arctic rifting to the development of Late Palaeozoic basins, which dominate the structur