Transient regional uplift in the Early Tertiary of the northern North Sea and the development of the Iceland Plume

Abstract

Abstract Forward and reverse 2D flexural modelling of syn-rift and post-rift stratigraphy, has been used to investigate departures from McKenzie post-rift subsidence for the Cretaceous-Tertiary following Late Jurassic rifting in the northern North Sea Basin. The analysis shows uplift in the Palaeocene of 375–525 m relative to calibrated McKenzie subsidence curves, followed by a rapid decrease in uplift in the Early Eocene of 160–310 m. Both Palaeocene uplift and Eocene subsidence increase northwards. The timing, distribution and magnitude of regional Palaeocene uplift is consistent with an origin relating to the development of a mantle plume between 65 and 55 Ma. Transient regional Palaeocene uplift in the northern North Sea Basin was produced by long wavelength dynamic uplift generated by the flow field of a mantle plume. Heating of the asthenosphere or lithosphere beneath the North Sea by hot plume material, or magmatic underplating are not believed to have contributed to Palaeocene uplift in the northern North Sea Basin. Rapid Early Eocene subsidence was generated by a decrease in dynamic uplift caused by a reduction in plume activity. The plume responsible for North Sea Palaeocene uplift may have been the early Iceland plume or a distinct British Tertiary Igneous Province plume related to the same mantle convection event.