Southern Region Chalk Group Lithostratigraphy: Sussex lithostratigraphy of Mortimore (1986a) - Sompting Beds

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The Sompting Beds, c. +40 m thick locally in the Isle of Wight, are marked by the Lancing Flint at the base, and the Whitecliff Marl at the top (Mortimore, 1986a).These beds comprise very soft, flinty chalk, key markers being the semi-continuous Charmandean Flint just below the middle of the succession, and the double-seamed large, nodular Cotes Bottom Flint near the top of the succession, the latter with occasional columnar or paramoudra morphology (Mortimore, 1986a).

The fauna of the Sompting beds is dominated by small macrofossils, especially locally abundant bryozoans, serpulids (particularly Conorca turbinella), and the inconspicuous micro-crinoid Applinocrinus cretaceus. The brachiopod Cretirhynchia limbata (sensu Gaster, 1924) also occurs, with the echinoids Offaster pilula nana, Echinocorys marginata and spines of Cidaris subvesiculosa (sensu Gaster, 1924). The belemnite Gonioteuthis also occasionally occurs.

Macrofossil Biozonation: A. cretaceus Subzone (pars)

Correlation: see Correlation with other Southern Region Chalk Group classifications

see Correlation with other UK Chalk Group successions

References[edit]

GASTER, C T A. 1924. The Chalk of the Worthing District, Sussex. Proceedings of the Geologists' Association, Vol. 35, p. 89-110.

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