| Upper Greensand Formation | |
|---|---|
| Stratigraphic range:Albian–Cenomanian113–94 Ma | |
 Sandstones of the Upper Greensand Formation above Blackgang,Isle of Wight | |
| Type | Geological formation |
| Unit of | Selborne Group |
| Underlies | Chalk Group |
| Overlies | Gault Clay |
| Area | Wessex Basin,Weald Basin |
| Thickness | 0–75 m |
| Lithology | |
| Primary | Sandstone |
| Other | Siltstone |
| Location | |
| Country | England |
TheUpper Greensand Formation is aCretaceousformation ofAlbian toCenomanian in age, found within theWessex Basin and parts of theWeald Basin in southern England.[1] It overlies theGault Clay and underlies theChalk Group. It varies in thickness from zero to 75 m. It is predominantly aglauconitic fine-grained sandstone, locally becoming silty. Fragmentary dinosaur remains, such as those assigned toIuticosaurus, have been recovered from this formation. It has been quarried as a building stone from Roman times, and used in London and the area of its outcrop from Devon to East Sussex.
Sandstones from the Upper Greensand have been used as building stone since at leastRoman times.[2]Reigate Stone wasmined from the Upper Greensand in north eastSurrey throughout theMiddle Ages andearly modern period,[3] forming the most important source offreestone inMedieval London.[2] In Dorset, the Shaftesbury Sandstone was quarried betweenShaftesbury andOkeford Fitzpaine and used in the Shaftesbury area and along theStour valley. In southeastern Devon, the Bindon Sandstone was quarried nearBranscombe and used in buildings such asExeter Cathedral.[4] Other building stones quarried from the Upper Greensand in the county include Salcombe Stone from near the border with Somerset, and the Green Glauconitic Sandstone from the western side of theBlackdown Hills.[5]
Hurdcott Stone was quarried inWiltshire and used particularly inMere and Shaftesbury. It is currently being produced from a quarry atBarford St Martin. Potterne Stone is quarried nearPotterne and used there and in theVale of Pewsey.[6] On theIsle of Wight the Upper Greensand has been quarried since Roman times, including Ventnor Stone nearVentnor, with varieties Green Ventnor Stone and Ventnor Foxstone, and Bonchurch Stone only found atBonchurch.Chert from the top of the formation has also been used as a building stone since the 17th century.[7] InWest Sussex andHampshire,Malmstone was quarried and used in buildings such asWinchester Castle[8] andAmberley Castle.[9] InEast Sussex, Eastbourne Sandstone was quarried from theforeshore atEastbourne, and used in buildings in the town such as the church of St Mary the Virgin.[10]