Lower Cretaceous Lower Greensand Group

The Lower Greensand Group comprises mainly sandstones with some silt and clay intervals. Theses sediments were deposited in shallow marine environments.
Atherfield Clay Formation: generally massive sandy mudstone. The base is marked variably by an impersistent phosphatic pebble bed with vertebrate bones, gritty sandstone or shelly sandy mudstone.
Hythe Formation: in the western Weald, the formation comprises mainly fine- to medium-grained, sparsely glauconitic sandstones and silts, locally pebbly, with calcareous or siliceous (chert) cement in beds in some areas. Some clay interbeds, including Fuller's Earth. In Kent and eastern Sussex the formation comprises alternating sandy limestones ("Ragstone") and glauconitic sandy mudstones (“Hassock”)
Easebourne Member: fine- to medium-grained glauconitic sands, some very well cemented (calcareous), with minor clay interbeds.
Rogate Member: a heterogeneous succession of coarse-grained pebbly sands, very glauconitic clayey pebbly sands, glauconitic pebbly and sandy clays, calcareously cemented pebble beds and coarse-grained pebbly sands.
Fittleworth Member: glauconitic sandy clays and clayey sands.
Pulborough Sandrock Member: fine-grained, fossiliferous sandstone. Coarse ferruginous sand locally present at top. Thin clay beds in places.
Marehill Clay Member: dark, locally glauconitic, silty clay.
Folkestone Formation: in Sussex, Kent and Surrey the formation comprises medium- and coarse-grained, well-sorted cross-bedded sandstones.

Sussex Geology - Stratigraphic Charts