The higher land, mainly north of the A27 overlies chalk, this is the dip slope of the South Downs which continue northwards for 9 kms. Waltham Down at 255 metres is one of the Downs’ highest points, being directly north of Westergate.
In the area between Aldingbourne and the Downs lie raised beach formations of shingle and sand, these are former coastlines. For example Norton and Slindon raised beaches ( within one near Eartham, Boxgrove Man was found).
They roughly follow a line above the A27 and are 500,000 years old.
The springs which flow into the rifes have their source in these beaches, as water from the deep chalk aquifers flows southwards towards the coast.
Much of the silty-loam gravel bearing soils on the lower plain have areas of water-bearing shifting sand strata.
These areas are characterised by high winter ground water levels, evidence of this is seen in Hook Lane, Church Road and Oving Road where surface flooding is persistent throughout the winter.
South of the railway, there is a unique strata of plasticene London clay, underlying the loam topsoil, this stretches to the Rife bank.
This has been excavated since 1990 to create a void for the Lidsey landfill.
Some of this clay will be used to cap over the waste mound and will be topped off with grade 2 soil from the overburden, enabling the establishment of pasture land for grazing.
The landfill is due to close in 2012.