Paris Basin

The landscape is one of very broad valleys (flood plains), modest watershed hills and well-drained plateaux of comparatively little altitude.

In the south-east and east the plain of Champagne and the Seuil de Bourgogne (Threshold of Burgundy) differential erosion of the strata has left low scarps with the dip slopes towards the centre.

Based on analysis of fossils recognized in the basin's strata during the 1820s and 1830s, the pioneering geologist Charles Lyell divided the Tertiary into three ages he named the Pliocene, the Miocene and the Eocene.

To the west, the strata folded by the Variscan rise below the more recent marine deposits in the hills of Brittany and, to the east, the Ardennes, Hunsrück and Vosges.

These include the Côte d'Or in the south-east (on an Alpine fault line) and, at a north end, the Hills of (French: Collines d') Artois which overlie the margin of London-Brabant Massif.