Location of the Limagne plain on a map of the Massif Central
The village of Usson on the edge of the Limagne plain
The Limagne is large plain in the Auvergne region of France in the valley of the Allier river, on the edge of the Massif Central. It lies entirely within the département of Puy de Dôme. The term is sometimes used to include this, and three other less extensive plains, that lie along the valley of the Allier, in which case the first is known as Grande Limagne to distinguish it from the others. The name is derived from the LatinLacus Magnus, or large lake.
The Limagne plain is a graben, downthrown from the Massif Central by a series of normal faults that border the western edge of the plain. It contains about 2 km of sediments, and the amount of stretching of the crust is estimated as 1.2–1.3. The rifting started in the Late Eocene and the main phase of subsidence continued into the Late Oligocene. The Limagne Graben forms part of a system of linked rifts, including the Rhine Graben, known as the European Cenozoic Rift System, that formed in response to compressional deformation of the Alpineforeland.