The geometry is less clear on the northwestern side of the basin due to the presence of thick Late Paleocene flood basalts.
Even where the lavas are absent the development of large sill complexes makes seismic imaging at deeper levels difficult.
There was a further episode of rifting during the Late Cretaceous to Paleocene that locally modified the existing basins and formed new depocentres such as the Foinaven Sub-basin.
At the end of the Paleocene, the area was affected by magmatism, part of the North Atlantic Igneous Province and a short-lived phase of uplift.
[1] Hydrocarbons have been discovered in reservoirs of Archean, Devonian, Carboniferous, Triassic, Jurassic, Cretaceous, Paleocene and Eocene age in a mixture of structural and stratigraphic traps.