The rift valley which contains the river Rhine and which lies between the Ardennes, the Vosges, and the Black Forest. The uplift occurred in the late Mesozoic, with rifting in the mid-Eocene and production of alkaline magmas in the Oligocene. In places, 3 km of sediment have been deposited. The Rhine graben formed synchronously with the Alpine collision and has been called an ‘impactogen’, i.e. a collisional rift that forms at the end of the Wilson Cycle.