Influence of emplacement of large igneous provinces on source-to-sink systems: the case study of Shetland during the Palaeocene

SUPERVISION: Christian Haug Eide, UiB, Tor Sømme, Equinor ASA and UiB, Stefano Patruno, University of Nicosia, François Guillocheau, University of Rennes 1, Cécile Robin, University of Rennes 1

PROJECT PERIOD: December 2020 - January 2024

RESEARCH GOALS; AIMS AND OBJECTIVES:

Our goal is to study how changes in parameters such as increased uplift rates and abrupt fluctuations in climate (both of which can be induced by large igneous provinces) can affect source-to-sink systems. The continental area of Shetland has been subject to a major uplift pulse in the Palaeocene, during the emplacement of the North Atlantic Igneous Province - something that has been linked to the impact of the Icelandic Plume. Mantle plumes have been shown to cause doming, uplift and lateral compensational subsidence during the multiple steps of their emplacement, effectively creating signature stratigraphic successions that can be recognized in affected areas. According to recent dynamic topography modelling, Shetland was close to an uplifted region of the plume’s head and margins during the Late Danian to Ypresian, while in the North Sea this was accompanied by a sharp increase in local subsidence and sedimentation. The timing and effects of this coupled cycle have not been fully constrained, especially due to inherent superimposed shorter-term perturbations and the effects of overlapping climatic variations, including the Palaeocene - Eocene Thermal Maximum (PETM).  

Using 3D and 2D seismic surveys, openly available well data and biostratigraphic data, we aim to quantify sediment volumes supplied through time in the East Shetland Platform and adjacent areas. Sedimentological data will then be used in conjunction with models of dynamic topography, S2S-signal-propagation properties, plume activity and palaeoclimatic data in order to derive whether supplied volumes can be related to changes in dynamic topography (mantle topography), precipitation and other key forcing parameters.  

Objectives 

The first objective of this research project is to establish a regional stratigraphic framework for the area, which will be based in modern sequence stratigraphy concepts and tied to the pre-existing biostratigraphic schemes. This will be used to reconstruct regional sediment volumes deposited during the Palaeocene. 

After this, we will interpret depositional environments and quantify the sediment volumes in each stratigraphic time unit. This will be done through fine-scale resolution mapping of seismic horizons. Using 3D seismic datasets and 3D seismic geomorphology, we aim to relate these to sedimentary conditions, directions of sediment transport and overall properties of supply systems. This will be particularly important during the evaluation of the PETM record in the Shetland platform. 

Finally, using published data on topographic and climatic evolution in the hinterland, and through knowledge of signal-propagation and sediment-routing properties of the S2S system, we should be equipped to establish the nature and origin of perceived perturbations in sediment supply.