AAPG Bulletin, Vol.81, No.11, 1827-1842, 1997
Shallow geology of the northern Barents Sea: Implications for petroleum potential
The shallow geology of the northern Barents Sea has been studied through analyses of geophysical data and geological samples from gravity cores. Mesozoic rocks subcrop in the entire study area, with Triassic-Middle Jurassic rocks dominating the shallowest and western part of the area, and Upper Jurassic-Lower Cretaceous rocks dominating the central areas. A palynologically investigated sample, representing in-situ bed rock, gives an Aptian-early Albian age, indicating that Lower Cretaceous units dominate the eastern part of the study area. These beds were deposited during shallow-marine conditions and show a petrographic composition comparable to the Carolinefjellet Formation of Svalbard. The thickness of the Lower Cretaceous section is almost 1000 m. Organic geochemical analyses of the Aptian-lower Albian rocks suggest a post-Early Cretaceous erosion of a maximum of 2000 m. An important tectonic event in the region was a compressive phase near the Cretaceous-Tertiary boundary. Occurrences of porous, well-sorted Lower Cretaceous sandstones succeeding organic-rich, mature Upper Jurassic and Lower Cretaceous shales, sealed by Lower Cretaceous shales within antiform settings, represent interesting play concepts in the study area. The petroleum potential has been limited by the post-Early Cretaceous uplift and erosion, resulting in the termination of hydrocarbon generation followed by gas expansion.