Onshore exposures of the North Atlantic Igneous Province have been studied in detail for over 200 years, whereas the more extensive offshore volcanic stratigraphy is significantly less well constrained with the exception of a small number of boreholes. Within this study we integrate seismic and well data across the northern Faroe–Shetland Basin and Møre Marginal High to improve understanding of the volcanic stratigraphy and its relationship to rifting in the NE Atlantic. Volcanic seismic facies, including compound and tabular lavas and hyaloclastites (representing subaerial and subaqueous emplacement), are interpreted across the study area, calibrated by the Lagavulin borehole. The volcanic sequence was erupted between c. 56.1 and 55.2 Ma, when subaerial conditions dominated in the region, but extensive lava deltas developed in a seaway east of the main lava field. Geochemical and thickness variations within the volcanic pile have important implications for the regional rifting history. MORB-like lavas at the base of Lagavulin, which thicken substantially northward, support an early onset of rifting near the Møre Marginal High prior to major thinning associated with continental breakup to the south and north. Following a period of erosion, smaller-degree melting caused the eruption of higher-TiO2/Zr lavas, marking the final ‘pre-breakup’ volcanism before emplacement of seaward-dipping reflectors.
This paper forms part of a PhD study conducted as part of the Natural Environment Research Council Centre (NERC) for Doctoral Training in Oil and Gas. It is sponsored by the University of Aberdeen and the British Geological Survey (BGS) via the British University Funding Initiative (BUFI), whose support is gratefully acknowledged. PGS and Spectrum are thanked for the generous provision of seismic data. Well data were downloaded from the UK Oil & Gas Common Data Access portal. Seismic interpretation was undertaken using IHS Kingdom software. Chris Jackson is thanked for editorial support and Kirsty Wright and Craig Magee are thanked for constructive reviews which substantially improved this manuscript.
Funding ID: ID0EPTBG1166, Funding Source: Natural Environment Research Council, Principal-award-recipient: Faye Walker; Funding ID: ID0E6ZBG1167 (grant number: NE/M00578X/1), Funding Source: British Geological Survey http://dx.doi.org/10.13039/501100002760, Principal-award-recipient: Faye Walker.