A regional stratigraphy is established between 64°N and 65°N dividing the upper Pliocene and Quaternary sediments overlying IKU Bedrock Units IX and X into Il informal units ( L, K, I, H, G, F, E, D, B, A and U) separated by regional reflectors. The database consisted of about 5000 km of seismic profiles ( site surveys, multichannel seismic tie lines between wells, selected conventional deep seismic lines, IKU's regional analog sparker grid), lithological and geophysical well information. 'Base Unit IX' represents the oldest event mapped and forms the basis for IKU Bedrock Units IX and X in the east and for the Plio/Pleistocene sediment wedge increasing to more than 1 500 m thickness westwards at the shelf edge. The delta-like coastal Unit IX ( of supposed Oligocene age) is very characteristic on seismic profiles. It has been mapped from Møre to Lofoten and probably consists mainly of sand. Most of the overlying sediments ( Units X to E) seem to have been deposited by glacial processes, which explains the high sedimentation rates compared to the older units. The undulating reflector forming the base of Unit D ( earlier assumed to be base Quaternary) is now interpreted as a result of the Saalian glaciation. The overlying layered sediments in Unit D consist of glaciomarine and marine ( Eemain) sediments. The three topmost units (B, A and U) are dominated by unsorted material representing Weichselian tills.
Upper Cenozoic stratigraphy on the Mid-Norwegian continental shelf