Kinematic analysis of the Upper Rhine Graben boundary fault system

This paper presents a new set of kinematic data for the central part of the Upper Rhine Graben. Fault slip measurements were gathered covering the near field of a 200-km-long segment of the graben boundary faults, on both sides. The resulting kinematic analysis shows a strong predominance of strike-slip faulting and some oblique-slip and pure normal faulting. Overall, there is a regional coherence in the orientations of the extensional and shortening axes associated with both types of faulting throughout the entire study area. The data set is best interpreted as the result of more or less continuous, sinistrally transtensive kinematics with a NW–SE to NNW–SSE oriented, or subvertical shortening, and a NE–SW to E–W oriented extensional direction. Local transpressive overprints are not reflected in the pattern of brittle deformation in the near field of the boundary fault system. We conclude that the opening history of the Rhine Graben may be less complex than hitherto assumed.