The Rhinegraben: Extension, subsidence and shoulder uplift

Abstract We apply a numerical model of the thermal evolution of a continental lithosphere undergoing extensional deformation to the Rhinegraben. Using reasonable parameters, the results of computations are in agreement with the present configuration of the rift and of its shoulders, as well as with their evolution since the Oligocene. Contrasting evolutions are reconstructed in the northern and southern Rhinegraben: whereas the Northern history is accounted for by a simple model of homogeneous stretching of the lithosphere, the history of the southern Rhinegraben cannot be explained without introducing two main periods of heterogeneous stretching. The results are locally supported by structural analyses of extensional patterns. Factors of extension average 1.2 in the axial portion of the Rhinegraben and 1.15 for the whole rift section, suggesting that the total amount of E-W extension reaches 6 km.