Cretaceous tectonostratigraphy of the Faroe–Shetland region

This study presents an appraisal of the Cretaceous tectonostratigraphical development of the Faroe–Shetland region. It combines details of the rock record with seismic stratigraphical information, and the resulting stratigraphic framework provides constraints on the timing and nature of sedimentary basin development in the Faroe–Shetland region, with implications for the Late Mesozoic development of the NE Atlantic Rift Zone. The division of the Cretaceous succession into two megasequences (K1 and K2) provides a first-order analysis of basin development. The components of the K1 megasequence represent the rift initiation and early syn-rift phases that span the late Berriasian–Turonian, whereas the K2 megasequence represents the rift climax incorporating basin enlargement and increased subsidence during the Coniacian–Maastrichtian. A higher resolution (second- to third-order) analysis of the component depositional packages highlights a sedimentary succession that is punctuated by episodes of uplift, erosion and contractional deformation. This pattern of coeval extension and compression is consistent with intra-plate strike-slip tectonic activity linked to the development of the NE Atlantic Rift Zone, and modulated by plate boundary processes, including Atlantic spreading and Alpine orogenic activity. There is no evidence for a substantive through-going marine connection in the Faroe–Shetland region until the Late Cretaceous. The Faroe–Shetland region is an area of complex geological structure located on the outer continental margin between northern Scotland (Orkney and Shetland islands) and the Faroe Islands (Fig. 1). This structural framework comprises a series of basins and highs that record a prolonged history of extension and rifting that took place episodically during the Late Palaeozoic, Mesozoic and Early Cenozoic. Devono-Carboniferous basins are a relic of post-Caledonian orogenic collapse, whereas Permo-Triassic, (mainly Late) Jurassic and Cretaceous basin development is related to the fragmentation of Pangaea, ultimately leading to continental break-up to the north and west of the Faroe Islands in the earliest Eocene (Doré et al. 1999; Roberts et al. 1999; Passey & Hitchen 2011; Ritchie et al. 2011; Stoker et al. in press).