The Barents-Kara Region has proved to possess gigantic hydrocarbon resources, and a basic understanding the paleogeographic evolution of this large region is crucial for developing valid play models for the different sub-basins. In the recent GeoBaSe project the paleogeographic evolution of the Barents- and Kara Seas have been outlined through a new series of 20 new paleogeographic maps spanning from Devonian to Eocene. The maps provide higher-resolution paleogeographic models compared to previous published maps, and they serve as useful means for understanding the lateral distribution of the main sedimentary units in the studied areas.
The GeoBaSe study involves the synthesis of existing Russian and Norwegian geological and geophysical data and their interdisciplinary interpretation, including the combination of potential field data with seismics, further calibrated with deep and shallow boreholes and surrounding outcrops. The project has produced an integrated tectonic, structural and paleogeographic framework for the Barents Sea, northern Pechora region and Kara Sea areas.
The refined geological fundament for the crustal pattern and basin architecture of the Barents Sea - Kara Sea region, reveals major differences in the basins characteristics from Western Barents Sea to Eastern Barents Sea. In the eastern Barents Sea region the following series of tectonic phases are recognized: Ordovician to Early Devonian passive continental margin, Early Devonian (Lochkovian to Eifelian) shelf destruction, Middle to Late Devonian (Givetian to lower Frasnian) pericontinental rifting, Late Devonian to Early Carboniferous development of marginal basins, Carboniferous to Permian collision, Late Permian to Triassic Uralian orogeny, followed by formation of epicontinental basins from the Early Jurassic and onwards. In the Late Paleozoic and Early Mesozoic the paleogeograhic regimes the Barents-Kara Region is closely connected with the evolution of the Uralian Ocean. The Novaya Zemlya sedimentary basins are interpreted as the marginal basins resulted from the pericratonic rifting near the Middle and Late Devonian boundary. The East Barents megatrough is interpreted as the foredeep basin influenced by the collision and complexe orogenic phases in the east of the study region.
In the western Barents Sea region the geological history can broadly be subdivided into major Paleozoic-Neogene tectonic phases including: The Caleodonian orogeny, Devonian and Permo - Carboniferous rifting, episodic Triassic-Early Jurassic intra-cratonic rifting episodes influenced by the Uralian Orogeny in the east, Late Jurassic-Cretaceous rifting events, leading to the Cenozoic breakup of the North Atlantic and the Arctic Ocean. Each of the tectonic phases recognized in Barents- Kara Sea regions led to various paleogeographic and sedimentary regimes providing the base for a variety of hydrocarbon play models within the Devonian to Eocene succession.