Abstract - The Cenozoic tectonic history of NW Europe is generally attributed to some combination of three principal controlling factors: North Atlantic opening, Alpine collision and formation of the Icelandic mantle plume. Using constraints from the high resolution Tellus aeromagnetic survey of Northern Ireland, we show that Palaeogene tectonics can be attributed to approximately N-S Alpine-related compression, forming NNW-trending dextral and ENE-trending sinistral conjugate faults, with the latter defined by kilometre-scale displacements along reactivated Caledonian/Carboniferous faults. This tectonism was, however, punctuated by pulsed magmatic intrusive and extrusive events, including four distinct dyke swarms which are attributed to NE-SW to E-W directed plume-related extension. Whilst this evidence shows, for the first time, that N-S Alpine compression was periodically overwhelmed by the dynamic stresses and uplift associated with pulsed mantle plume-related deformation, associated strike-slip faulting may have controlled the locus of volcanic activity and central igneous complexes, and the location of sedimentary depocentres.
Journal of The Geological Society, London, 169, 29-36, 2012.