Vale of Kent

The Weald is the eroded remains of a geological structure, an anticline, a dome of layered Lower Cretaceous rocks cut through by erosion to expose the layers as sandstone ridges and clay valleys.

The oldest rocks exposed at the centre of the anticline are correlated with the Purbeck Beds of the Upper Jurassic.

[2] The rocks of the central part of the anticline include hard sandstones, and these form hills now called the High Weald.

The peripheral areas are mostly of softer sandstones and clays and these form the gentler rolling landscape of Low Weald, of which the Vale of Kent is a part.

[1] The Weald-Artois Anticline continues some 65 km (40 mi) further south-eastwards under the Straits of Dover, and includes the Boulonnais of France.

Geological map of Southeast England
Geology of south-eastern England. The High Weald is in lime green (9a); the Low Weald, darker green (9). Chalk Downs, pale green (6)
Cross-sectional diagram of eroded layers of geological anticline with locations of towns indicated
Geological section from north to south: High and Low Weald shown as one