The BGS Lexicon of Named Rock Units — Result Details

Newhaven Chalk Formation

Computer Code: NCK Preferred Map Code: NCk
Status Code: Full
Age range: Santonian Age (KS) — Campanian Age (KC)
Lithological Description: Composed of soft to medium hard, smooth white chalks with numerous marl seams and flint bands, including abundant Zoophycos flints (notably at levels near the base). The formation is known to contain distinct phosphatic chalks of limited lateral extent. Equivalent beds, the Margate Chalk of north Kent, are marl-free and contain little flint.
Definition of Lower Boundary: The lower boundary is conformable at the base of Buckle Marl 1 in the Sussex succession (Mortimore, 1986). In typical sections, the boundary is the lower limit of chalk with numerous marl seams above several tens of metres of chalk without marl seams (the Seaford Chalk Member). The incoming of common Zoophycos flints and the presence of the zonal Uintacrinus socialis crinoid at the base of the Newhaven Chalk Formation are useful indicators in the field.
Definition of Upper Boundary: The upper boundary is placed at the top of Castle Hill Marl 2 in the type locality at Seaford Head, Sussex, where there is some evidence of a reduction in marl thickness over a structural high. In expanded trough areas a higher set of marls, the Pepper Box Marls, are well developed and the boundary is taken at this level.
Thickness: 45 to 75m in the basinal sequences of the Southern Province. Limited by sub-Palaeogene erosion over large areas of Southern Britain.
Geographical Limits: Known throughout the Southern Province northward to the Pewsey/Kingsclere structure and as limited outliers north of this structure. Its presence within the Chilterns and northward into East Anglia in the Transitional Province is not well known.
Parent Unit: White Chalk Subgroup (WHCK)
Alternative Name(s): none recorded or not applicable
Reference Section  Paulsgrove Pit, Portsdown. 
Reference Section  White Nothe, Dorset. 
Reference Section  Ballard Point, Dorset. 
Reference Section  Whitecliff Bay on the Isle of Wight. 
Reference Section  Brighton to Newhaven cliffs, Sussex. 
Reference Section  White Ness [TR 397 710] to Foreness Point [TR 383 717] and Margate [TR 354 714] on the Thanet Coast in Kent, Margate Chalk Member. 
Type Section  Basal boundary stratotype and type section: seacliffs at Seaford Head, East Sussex. 
Mortimore, R N. 1986. Stratigraphy of the Upper Cretaceous White Chalk of Sussex. Proceedings of the Geologists' Association, Vol.97(2), 97-139. 
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. 
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. 
Bristow, C R, Mortimore, R N and Wood, C J. 1999. "Lithostratigraphy for mapping the chalk in southern England" by Bristow et al. (1997): discussion. Proceedings of the Geologists' Association, Vol.110, 68-72. 
Rawson, P F, Allen, P M and Gale, A S. 2001. The Chalk Group - a revised lithostratigraphy. Geoscientist, Vol.11, p.21. 
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. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E300 E314 E317 E327 E332 E341 E342 E343