Weald–Artois Anticline

The western part of the ridge (the Weald of Kent, Sussex and Surrey in England) has been greatly eroded, with the presumed chalk surface removed to expose older, Lower Cretaceous rocks (Wealden Group) and a small area of Upper Jurassic Purbeck Beds.

[2] On the French side of the English Channel more Upper Jurassic rocks crop out in a small area around Boulogne-sur-Mer and Desvres.

Gupta et al. argue that the section of the anticline between Britain and France was destroyed by two megafloods caused by the breaching of proglacial lakes.

The second megaflood occurred around 160,000 years ago during the Wolstonian/Saalian glaciation (MIS 6), after which Britain would be an island during periods of high sea level.

[4] During the most recent glacial period, lowering of sea levels joined the British Isles once more to the continental mainland of Europe via Doggerland, until about 6500–6200 BCE.

Geologic map of southeast England and the region around the English Channel , showing the Weald-Artois anticline in its regional context.
Cross-section over the Wealden anticline
The white cliffs of Dover as seen from Cap Gris-Nez . The Straits of Dover were carved out of the anticline surface layer, presumably chalk, by glacial lake outburst floods