Numerical backward and forward modelling of the southern Upper Rhine Graben (France-Germany border): new insights on tectonic evolution of intracontinental rifts

This paper presents numerical models, based on finite elements and contact theories, of a segment of the southern Upper Rhine Graben (URG). Both forward and backward models are presented. The results demonstrate the possibility to successfully model a complex multi-block geological domain with finite element methods. In addition, they provide crucial information on the tectonic evolution of this segment of the URG. They document the distribution of deformation and the possibility of a strike-slip component of displacement during rifting. They also evidence tectonic features that might be characteristic of oblique rifting, such as a zone of high strain and brittle behaviour that follows the Graben axis. This zone coincides with the surface trace of the Present Day Rhine River fault, which is probably a major structure for the rifting history of the URG.