The sequence boundary in Sussex is a winnowed horizon of sponge, inoceramid and brachiopod debris c. 4 m below Belle Tout Marl 1 at Seaford Head [TV 4995 9750], and the overlying lowstand systems tract is less than a metre thick (Grant et al., 1999). The base of the transgressive systems tract is somewhat speculatively placed at the first flint band above the sequence boundary in Sussex, and its top is at the level of Belle Tout Marl 2 (Grant et al., 1999). The highstand systems tract extends to just below the Seven Sisters Flint in Sussex (Grant et al., 1999).
GRANT, S F, COE, A L, ARMSTRONG, H A. 1999. Sequence stratigraphy of the Coniacian succession of the Anglo-Paris Basin. Geological Magazine, 136, 17–38.