With its soils consisting of seven different geological layers and its degraded oceanic climate, the Champagne is suitable for growing vines. Chalk constitutes the keystone of the region's terroirs. The Montagne de Reims (Reims Mountains) and the Côte des Blancs (Whites Coast) spread over chalk soils dating from the Upper Cretaceous 65 million years ago. It has always played a significant role in the local growing of vine. Traces of vines from 55 million years ago were found in the limestone of Sézanne, in the Marne department. The thickness of the chalk vein varies between 656 to 1,640 ft (200 to 500 m).