Cenozoic pre- and post-breakup compression in the Faroe-Shetland area, within the context of the NE Atlantic

• Main Authors: Johnson, H., Quinn, M.F., Kimbell, G.S., Stoker, M.S., Smith, K., Olavsdottir, J., Varming, T.
• Format: Report
• Language: English
• Published: British Geological Survey 2012
• Subjects: Tilting; Judd; Fugloy; Fugloy*
• Online Access: http://nora.nerc.ac.uk/id/eprint/530660/; https://nora.nerc.ac.uk/id/eprint/530660/1/CR12017N.pdf

This report is primarily based upon the interpretation of oil industry 2D seismic data, and aims to elucidate aspects of Cenozoic tectonostratigraphic development in the Faroe–Shetland region, especially with regard to post-breakup compression. Evidence of Cenozoic and Late Cretaceous pre-breakup compression and deformation is briefly reviewed. We have utilised established seismo-stratigraphic frameworks and a recently updated scheme for the post-breakup Eocene (Stronsay Group) succession, which are largely based upon the recognition of units bounded by regional unconformities. The seismic expression, extent and thickness of the seismo-stratigraphic units are illustrated by geoseismic profiles, structure contour maps and isochore maps, which are used to analyse the spatial and temporal development of post-breakup compression and deformation within the Faroe-Shetland region. The Faroe-Shetland region records a complex spatial and temporal pattern of departures from the thermal subsidence normally associated with passive margins, including broad uplifts and accelerated basinal subsidence together with fold development up to kilometre scale. The phases of latest Eocene / earliest Oligocene ‘sagging’ (accelerated subsidence) and early Pliocene uplift and exhumation (tilting) appear to be coeval with compression. Indeed, compression appears to have been active throughout post-breakup times, although the loci of deformation have varied both spatially and temporally. Conceivably, some of the large scale sagging, tilting and uplift may be associated with lithospheric folding. Much of the intra-Eocene folding appears to be focused in the southwestern part of the Faroe-Shetland region, around the Munkagrunnur Ridge and Judd area, where phases of shelf progradation are preserved and may be associated with contemporaneous uplift. However, there also appears to be evidence of episodic intra-Eocene and younger uplift in the area around the northern Fugloy Ridge. The overall shaping of the Faroe-Shetland Channel appears to ...