| dc.description.abstract | Conglomerates and sandstones from the Permian Rotliegend Group contain clasts of Caledonian origin that suggests a basement source area and a sediment transport direction connected to the tectonic activity in Carboniferous and Permian time. The existing outline of the basement rocks in the Norwegian North Sea was incomplete, and therefore a new map of the basement lithologies was made based on core viewing and interpretations of crystalline thin sections from the Norwegian sector. Possible source areas and transport directions for Permian deposits were indicated based on point counting and core viewing of sandstones and conglomerates in the southern and western Norwegian North Sea with a specific focus on lithic fragments. The southern part of the Norwegian sector indicates phyllite and schist, whereas monzogranite, quartz-monzonite, monzodiorite, diorite, metasedimentary and mafic plutonic rocks, gneiss and andesite were identified in the western sector in the Norwegian North Sea. The cores and thin sections from the basement from the northern Norwegian sector show an abundance of dark gneiss. The crystalline clasts composed of monzogranite in conglomerates and sandstones in section 16 and 25 on the Utsira High suggests that the granitic area in sector 16 on the Utsira High acted as a source area to these Permian Rotliegend sedimentary rocks, resulting in a main sediment transport direction towards N-NW. The Rotliegend conglomerates also suggest that the underlying basement rock can act as a source rock due to fault activity. As a conclusion, the map of the basement lithologies and the interpretations of lithic fragments in Rotliegend sandstones and conglomerates are useful aids in reconstructing the post-Variscan sediment transport direction in the southern and western sectors of the Norwegian North Sea. | |
