The BGS Lexicon of Named Rock Units — Result Details

Margate Chalk Member

Computer Code: MACK Preferred Map Code: MaCk
Status Code: Full
Age range: Santonian Age (KS) — Campanian Age (KC)
Lithological Description: Marl-free smooth white chalk with little flint, weakly developed indurated iron-stained sponge beds. There are no formal subdivisions, but informally the member includes a number of laterally persistent flint and marl beds named in Robinson (1986), which can be traced outside Kent in the Southern and "Transitional" provinces where they are correlated with the named beds of Mortimore (1986) within the Newhaven Chalk Formation.
Definition of Lower Boundary: The lower boundary is conformable at the surface immediately above the Barrois Sponge Bed in Thanet (Robinson, 1986).
Definition of Upper Boundary: The upper boundary is limited by the sub-Palaeogene erosion surface in the Isle of Thanet.
Thickness: Up to 24m in the North Foreland to Foreness Point and Palm Bay sections on the Isle of Thanet in north Kent.
Geographical Limits: Confined to the Thanet area of Kent and possible northwards into Essex and southern East Anglia.
Parent Unit: Newhaven Chalk Formation (NCK)
Previous Name(s): Margate Member [Obsolete Name and Code: Use MACK] (*917)
Margate Chalk [Obsolete Name and Code: Use MACK] (-385)
Margate Chalk Formation [Obsolete Name and Code: Use MACK] (-1679)
Margate Member [Obsolete Name and Code: Use MACK] (*917)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Partial Type Section  White Ness, Margate, northeast Kent. Exposure on the foreshore and in the lower cliffs, see Robinson (1986). 
Partial Type Section  North Foreland [TR 398 705] to Foreness Point [TR 385 717], Margate, northeast Kent. Exposure on the foreshore and lower cliffs, see Robinson (1986). 
Reference Section  Palm Bay [TR 380 715] on the Isle of Thanet, north Kent. Exposures on the foreshore and above the sea wall show the full formation as known. 
Reference(s):
Gale, A S, Wood, C J and Bromley, R G. 1987. The lithostratigraphy and marker bed correlation in the White Chalk (Cenomanian-Campanian) of southern England. Mesozoic Research, Vol.1, 107-118. 
Mortimore, R N, Wood, C J and Gallois, R W, 2001. British Upper Cretaceous Stratigraphy. Geological Conservation Review Series. No. 23. (Peterborough: Joint Nature Conservation Committee.) 
Dowker, G. 1870. On the Chalk of Thanet, Kent and its connection with the Chalk of east Kent. Geological Magazine, Vol.7, 466-472. 
Whitaker, W. 1865. On the Chalk of the Isle of Thanet. Quarterly Journal of the Geological Society of London, Vol.21, 395-398. 
Bristow, C R, Mortimore, R N and Wood C J. 1997. Lithostratigraphy for mapping the Chalk of southern England. Proceedings of the Geologists' Association, Vol.108(4), 293-315. 
Hopson, P M. 2005. A stratigraphical framework for the Upper Cretaceous Chalk of England and Scotland, with statements on the Chalk of Northern Ireland and the UK Offshore Sector. British Geological Survey Research Report RR/05/01 102pp. ISBN 0 852725175 
Robinson, N D. 1986. Lithostratigraphy of the Chalk Group of the North Downs, south-east England. Proceedings of the Geologists' Association, Vol.97(2), 141-170. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E273 E274 E289 E290