| Bouldnor Formation | |
|---|---|
| Stratigraphic range: Priabonian-Rupelian ~ | |
| Type | Geological formation |
| Unit of | Solent Group |
| Sub-units | Bembridge Marls Member, Hamstead Member, Cranmore Member |
| Underlies | Alluvium |
| Overlies | Bembridge Limestone |
| Thickness | >50 m (160 ft) |
| Lithology | |
| Primary | Clay |
| Location | |
| Region | England |
| Country |  UK |
The Bouldnor Formation is a geological formation in the Hampshire Basin of southern England. It is the youngest formation of the Solent Group and was deposited during the uppermost Eocene and lower Oligocene.