A summary of the geological sequence present within the Thames Basin along with the aquifer classification. Jump to the key
| Quaternary | ||
| Neogene | Lenham Formation | |
| Palaeogene | Barton Group | |
| Bracklesham Group | Camberley Sand Formation | |
| Windlesham Formation | ||
| Bagshot Formation | ||
| London Clay Formation | ||
| Harwich Formation | ||
| Lambeth Group | Woolwich Formation | |
| Reading Formation | ||
| Upnor Formation | ||
| Thanet Sand Formation | ||
| Cretaceous | Chalk Group | |
| Selbourne Group | Upper Greensand Formation | |
| Gault Formation | ||
| Lower Greensand Group | Folkestone Formation | |
| Sandgate Formation | ||
| Hythe Formation | ||
| Atherfield Clay Formation | ||
| Wealden Group | Weald Clay Formation | |
| Tunbridge Wells Sand Formation | ||
| Wadhurst Clay Formation | ||
| Ashdown Formation | ||
| Purbeck Group | ||
| Jurassic | Portland Group | |
| Kimmeridge Clay Formation | ||
| Amphill Clay Formation | ||
| Corallian Group | ||
| Oxford Clay Formation | ||
| Kellaways Clay Formation | ||
| Great Oolite Group | Cornbrash Formation | |
| Forest Marble Formation | ||
| White Limestone Formation | ||
| Taynton Limestone Formation | ||
| Fullers Earth Formation | ||
| Inferior Oolite Group | ||
| Lias Group | Whitby Mudstone Formation | |
| Marlstone Rock Formation | ||
| Dyrham Formation | ||
| Charmouth Mudstone Formation |
| Non-aquifer, mainly muds and mudstones | ||
| Major aquifer, strategic importance, carbonates and sandstones | ||
| Minor aquifer, locally important, variable lithology | ||