Multiphase deformation history of the Porcupine Basin, offshore west Ireland

The Porcupine Basin is a large underexplored sedimentary basin located offshore west of Ireland within the structurally complex European North Atlantic Margin. has evolved through multiple Jurassic–Recent phases deformation and although overall plate tectonic context margin well-documented, there are still uncertainties regarding activity, their associated strain distribution fault kinematics. Based on analysis volumes 2D 3D seismic data from Basin, we provide an overview nature origin systems, both nontectonic, with links to regional events where possible. Three distinct basin-wide tectonically induced extensional faulting recognized: (a) Late Jurassic N-S NE-SW trending rift faults, (b) Cretaceous E-W ENE-WSW normal faults (c) Mid Eocene faults. were active over period 11.5 Myr between Oxfordian Kimmeridgian but intervening 4.5 quiescence providing two-stage evolution. in broadly correlates extension Celtic Sea basins tentatively attributed rotational spreading Bay Biscay south. phase extension, which coincides onset Europe Greenland (Atlantic spreading), resulted partial reactivation A series non-tectonic systems occur specific stratigraphic intervals suggesting compactional or gravitationally driven origin, including basinward dipping Palaeocene–early deltaic sequence, tiers polygonal Cretaceous, late Neogene strata.