Influence of basement fabrics on fault reactivation during rifting and inversion: a case study from the Celtic Sea basins, offshore Ireland

The evolution of rift basins is often influenced by the reactivation pre-existing structures, a response that partly controlled angular relationship between fault strike and subsequent extension/compression axes. In Celtic Sea basins, offshore Ireland, Caledonian Variscan structures form heterogeneous basement for rifting in Triassic–Jurassic Cretaceous later Pyrenean inversion Paleogene. Using 2D 3D seismic reflection data, we evaluate impact range on style deformation within basin margin axis settings. earlier phases arising from NW–SE extension exploited NNE–SSW-, NE–SW- ENE–WSW-trending structures. By contrast, rifting, with dominant north–south direction, generated newly formed, roughly east–west-trending normal faults, which interacted faults were only reactivated when they at >45° to direction. During compression, orthogonal extensional highly oblique as reverse strike/oblique slip together formed strike-slip faults. Combining constraints multiple phases, this study highlights variably oriented changing compression vectors, associated changes behaviour mode formation. Supplementary material: location regional lines detailed description interpretation are available https://doi.org/10.6084/m9.figshare.c.6168279