Palaeocene uplift and subsidence events in the Scotland–Shetland and North Sea region and their relationship to the Iceland Plume

Abstract

This paper documents stratigraphic evidence for Palaeocene uplift and subsidence events in the Scotland–Shetland and North Sea region, and considers whether these were generated by the initiating Iceland Plume. The Palaeocene succession in the North Sea contains two types of stratigraphic surface. The high-gamma mudstone represents a maximum flooding event associated with marine transgression. The unconformity surface is overlain by sandstone, reworked chalk or tuff, and represents submarine or subaerial erosion and missing section. Biostratigraphic dating allows these surfaces to be correlated throughout the basin, where they occur within a suite of shelf, slope and basinal sedimentary rocks. At least 14 short duration (0.1–0.3 Ma), unconformity–maximum flooding couplets are recognized within the Danian to lowest Ypresian interval, which lasted from 65 to 54 Ma. These uplift–subsidence cycles may have been caused by episodic plume-related magmatic injection near the Moho and associated fluctuations in dynamic support. Alternatively, the short-term cycles may reflect a eustatic control. Regional mapping of the 14 events is required to confirm the relative importance of plume-related and eustatic events.