Geology of Berkshire

The surface of the county of Berkshire, England can be divided into three bands: the county's downlands, south and east of which the London Clay spans almost the whole county, and in the south-east corner sandy Palaeogene heath covers the London Clay. This is an oversimplification, because not everywhere have later layers been eroded away and because layers between the chalk and the London Clay survive in some places.

The western end of the county lies over the Berkshire syncline, and the whole county is shaped by the north-western limb of the London Basin 'synform' that forms the Chilterns (and further west, the Berkshire Downs), and the chalk and later deposits that have filled both synforms.^[1]