Southern Region Chalk Group Lithostratigraphy: Sussex lithostratigraphy of Mortimore (1986a) - Splash Point

From Earthwise
Jump to navigation Jump to search

The Splash Point Beds, c. 14 m thick in Sussex, are marked by the lowest of the Buckle Marls at the base, and the Brighton Marl at the top (Mortimore, 1986a). They comprise soft to very soft, flinty chalk, with the six Buckle Marls in the lower part of the succession, and a further interval of marls (the Hawks Brow Marl and the Brighton Five) in the middle and higher parts of the Splash Point Beds (Mortimore, 1986a). Key Flints are named (in ascending order) the Buckle Flint, Hawks Brow Flint and Brighton Flint (Mortimore, 1986a). Sponge beds locally occur, and one is associated with the Hawks Brow Flint (Young & Lake, 1988).

The fauna of the Splash Point Beds is dominated in the lower and middle part by the crinoid Uintacrinus socialis (usually found as isolated small calyx plates and brachials), and in the upper part by the crinoid Marsupites testudinarius (also found mainly as isolated calyx plates, but rarely, as semi-complete calices) (Mortimore, 1986a; Young & Lake, 1988). The echinoids Micraster coranguinum and M. rostratus also occur (Mortimore, 1986a).

Macrofossil Biozonation: U. socialis Zone & lower M. testudinarius Zone

Correlation: see Correlation with other Southern Region Chalk Group classifications

see Correlation with other UK Chalk Group successions


LAKE, R D, YOUNG, B, WOOD, C J & MORTIMORE, R N. 1987. Geology of the country around Lewes. Memoir of the British Geological Survey.

MORTIMORE, R N.1986a. Stratigraphy of the Upper Cretaceous White Chalk of Sussex. Proceedings of the Geologists' Association, Vol. 97(2), 97-139.

See: flint, marl