Cretaceous to Recent Inversion Structures in the Southwestern Barents Sea

Ivar Grunnaleite
IRIS (Int. Research Inst. of Stavanger), N5008 Bergen, Norway

Based on interpretation of regional seismic from the southwestern Barents Sea the occurrence of contractional and inverted structures are mapped, and described. The observations are summarized in a structural map showing the observed compressional faults, inverted faults, synclines and fold axes and as a summary chart of observations and possible dating. Compressional structures and signs of positive inversion structures are widespread throughout the southwestern Barents Sea, but occur mainly along the major fault complexes and in their adjacent basins. Some contractional structures are nevertheless found on the flanks of the structural highs. In general the number of inversed structures and their magnitude of compressional reactivation increases towards NW in the studied area. The main trend of inverted structures strike SSW-NNE to SW-NE. Several phases of inversion can be identified, but due to strong uplift and repeated regional erosion exact dating are in many cases difficult. At least four phases of inversion and compression are identified in this study. namely in early Cretaceous, late Cretaceous, in Cenozoic and a late phase from Cenozoic (?) to recent time. Early Cretaceous: Only observed along the western margin of the Loppa High Late Cretaceous: Salt movement in the Bjørnøya Basin and coeval large scale folding in the adjacent Bjørnøyrenna Fault Complex Cenozoic: More widespread inversion with a range of structures over the entire SW Barents Sea. Recent deformation involve up to NW contraction.

AAPG Search and Discovery Article #90072 © 2007 AAPG and AAPG European Region Conference, Athens, Greece