Behind this are 300–350 metres of much less resistant clays and greensands (Wealden clays, Gault and Upper Greensand).
Large quarries at Nuthurst and Stammerham (near Christ's Hospital) school are no longer extant, but others survive in isolated Wealden settings.
He was a long-time collector from the Wealden cliffs of the Isle of Wight, and his work on vertebrate palaeontology included studies of Iguanodon and Hypsilophodon from the Wealden (Lower Cretaceous).
The type species of Pholidosaurus is P. schaumburgensis, named in 1841 from the Wealden, or Hastings Sand, of Bückeburg, Germany.
The Riverhead parkland is part of the former Montreal Park (the remaining part is an estate of detached homes) and offers walks and children's recreation areas traversing the wealden greensand vale of the Darent Valley between Riverhead Infants School and Brittains Lane, Sevenoaks.