INTRAPLATE STRESSES AND DYNAMIC ASPECTS OF RIFTED BASINS

Intraplate stresses play a important role during the syn- and post-rift evolution of sedimentary basins. Deviations from long-term thermal patterns of post-rift subsidence as well as the development of unconformities within rifted basins reflect to a large extent the temporal fluctuations of the regional stress fields in the lithosphere. It appears that incorporation of intraplate stresses in dynamical models for basin development, together with a quantification of the role of petrological changes in the crust-lithosphere system, can explain some of the observed shortcomings of thermal models of post-rift basin subsidence. Late Neogene accelerations in tectonic subsidence in the deeper parts of rifted basins in the Northern Atlantic and Mediterranean regions could reflect a change in the level of intraplate stress over large areas of the globe. Non-thermal contributions to the subsidence record affect estimates of crustal extension and, consequently, influence the depth at which hydrocarbon source rocks enter the maturity window. Stress-induced changes in basement topography have also important consequences for the budget of fluid flow in the deeper parts of the sediment fill of the rifted basins as well as on the dynamics of diapirism.