Sedimentation and basin evolution in the Paleogene of the Northern North Sea and Faeroe–Shetland basins

Abstract

Thermal uplift of northern Britain during the Paleogene converted the Northern North Sea and Faeroe-Shetland areas from deep, sediment-starved basins into areas dominated by coarse clastic submarine fan and deltaic sedimentation. The uplift resulted from the initiation of a thermal plume which affected much of Greenland, western Norway and northern Britain in the Paleogene and which continues today, its axis lying under Iceland. The volume and grain size of the clastic input increased during the Paleocene as the source area was uplifted. This uplift reached a peak in the mid-Thanetian (late Paleocene) when large volumes of coarse clastic sediment poured east into the Northern North Sea Basin and northwest into the Faeroe–Shetland basin to accumulate as basin floor fans. Hebridean volcanism also peaked at this time, supplying tuffaceous sands which are found in both basins, as well as lavas which erupted over much of the area between the Hebrides and the Faeroes. The basin edges acted as bypass zones, sediments being only temporarily dumped on delta slopes before failure transported them basinward in turbidity currents. Thus the fluvial input was not significantly reworked and the fans developed as mixed sand–mud systems. By the late Thanetian, fan sedimentation had shallowed the basins sufficiently for deltas to prograde seawards. Small fans lay at the foot of these deltas and coal swamps developed on the delta plains. Sedimentation almost completely filled the relatively small Faeroe–Shetland Basin. In the early Ypresian (earliest Eocene) volcanism became concentrated along the rift northwest of . . .