Strength reversal in Europe's intraplate lithosphere: Transition from basin inversion to lithospheric folding

An intriguing paradox in European tectonics is that present intracontinental seismicity seems to be broadly distributed, whereas past deformation was restricted to sedimentary basin areas. These basins were created by repeated Mesozoic rifting and later affected by pervasive Late Cretaceous-early Tertiary inversion. We propose that the change from localized deformation to distributed seismicity reflects changes in strength due to an interplay between Neogene thermal perturbations by mantle plumes and stress-induced intraplate deformation. As a result, inversion tectonics in the North Sea Basin area ceased and gave way to lithospheric folding, which is most pronounced in onshore Paleozoic massif areas. Thermomechanical models demonstrate that this important transition in the mode and distribution of intraplate deformation can be explained by a strength reversal resulting from the combined effects of changes in Moho depth due to the transition from rifting to inversion and heating by mantle plumes. © 2005 Geological Society of America.