The sequence boundary is placed immediately below the lowest of two thin marl bands, c. 4.5 m above the Seven Sisters Flint at Seaford Head, Sussex (Grant et al., 1999). The base of the transgressive systems tract coincides with the Tarring Neville Flint in Sussex, but this interval is very thin (less than a metre in the UK) throughout the Anglo-Paris Basin, the top in Sussex being marked by a slightly nodular, sponge-rich horizon (Grant et al., 1999). The highstand systems tract comprises flint dominated chalk 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.