Chalk Group Lithostratigraphy: East Anglia - Beeston Chalk
The Beeston Chalk, c. 33m (Arthurton et al., 1994) to c. 40 m (Pitchford, 1990a) thick, is exposed on the foreshore east of Sherringham [TG 165 435], north Norfolk, below Beeston Hill, and is characterised by the development of 'ring flints' (Wood, 1988). Thes shallow flint rings, only apparent in plan-view (eg. bedding plane surfaces), are typically c. 0.9-1.8 m in diameter, and often enclose smaller rings (Jukes-Browne & Hill, 1904). Laterally continuous horizons rich in Inoceramus shell are characteristic (Wood, 1988), and in the Beeston Chalk of the Trunch Borehole [TG 2933 3455] there are unusually large specimens of the bivalve Pseudolimea granulata (Arthurton et al., 1994). Specimens of the echinoid Echinocorys from the middle hardground at the base of the Beeston Chalk at Sheringham compare with those from the highest sponge bed (= Hardground III of Wood, 1988) at Catton Grove (Peake & Hancock, 1970). The highest of the Sheringham sponge beds ( 'near Upcher's Groyne at the eastern end of Sheringham promenade') yields frequent specimens of the heteromorph ammonite Baculites, and possibly equates with a marked hardground in the Beeston Chalk at Caistor St. Edmunds [TG 2390 0466], Norwich (Peake & Hancock, 1970), which Wood (1988) appears to have identified as the 'Baculites Bed'. The top of the Beeston Chalk is an un-named hardground exposed on the foreshore 180 m east of West Runton [TG 1795 4283], characterised by accumulations of echinoids (Echinocorys) and saurian vertebrae (Peake & Hancock, 1970; Pitchford, 1990a).
Macrofossil Biozonation: B. mucronata Zone
Correlation: see Correlation with the Chalk Group of other UK regions
References
JUKES-BROWNE, A J & HILL, W.1904. The Cretaceous rocks of Britain. Vol. 3 - The Upper Chalk of England. Memoir of the Geological Survey of the United Kingdom.
PEAKE, N B & HANCOCK, J M. 1970. The Upper Cretaceous of Norfolk [reprinted with corrigenda and addenda] In LARWOOD, G P & FUNNELL, B M (eds.), The Geology of Norfolk. London & Ashford.
PITCHFORD, A J.1990a. A Summary of the stratigraphy of current exposures of Belemnitella mucronata Zone Chalk (Campanian, Upper Cretaceous) in Norfolk. Bulletin of the Geological Society of Norfolk, Vol. 40, 3-24.
WOOD, C J. 1988. The stratigraphy of the Chalk of Norwich. Bulletin of the Geological Society of Norfolk, No. 38, 3- 120.
See: Catton Sponge Bed