European Cenozoic Rift System

The European Cenozoic Rift System (ECRIS) is an 1100 km long system of rifts formed in the foreland of the Alps as the lithosphere responded to the effects of the Alpine and Pyrenean orogenies. The system began to form during the Late Eocene and parts, particularly the Upper and Lower Rhine Grabens, remain seismically active today and are responsible for most of the larger earthquakes in Europe, north of the Alps.

The ECRIS consists of a series of rifts and associated transfer faults extending from the Mediterranean to the North Sea.

This north-south trending rift structure formed in the middle Eocene creating a lake that is now the Limagne plain. The main phase of subsidence continued until the Late Oligocene. The graben is controlled by faults on its western side and has a fill of up to 2 km of Cenozoic sediments.

The Bresse Graben lies to the east of the Limagne Graben. It initiated during the Eocene but the rifting stopped during the period from Late Oligocene to middle Miocene, but resumed in the Late Miocene. The eastern margin of the basin was overridden by thrust faults from the Jura Mountains, the leading edge of the alpine thin-skinned deformation.

The Upper Rhine Graben extends from the northern edge of the Jura mountains in the south up to the triple junction where the ECRIS branches. Rifting initiated here in the Oligocene but the northern and southern parts of the graben show distinct post-Oligocene histories. In the Miocene the southern part of the graben became uplifted, while the northern part continued to subside into the . Currently the Upper Rhine Graben is thought to be experiencing dextral strike-slip reactivation.

...
Wikipedia