The BGS Lexicon of Named Rock Units — Result Details

Sandgate Formation

Computer Code: SAB Preferred Map Code: SaB
Status Code: Full
Age range: Aptian Age (KP) — Aptian Age (KP)
Lithological Description: Fine sands, silts and silty clays, commonly glauconitic; some sands limonitic or calcareous; some soft sandstones.
Definition of Lower Boundary: The base is taken at the base of Easebourne Member, Fittleworth Member or Rogate Member, where present. Otherwise, at the base of a condensed succession, at the base of heterogeneous sediments of the Sandgate Formation, overlying the uniform Hythe Formation succession. Note that in much of Sussex the Sandgate Formation cannot be separated from the Hythe Formation with confidence (Young and Lake, 1988).
Definition of Upper Boundary: The top is taken at the top of the dark clays of the Marehill Clay Member (where it is present); elsewhere at the upward change from argillaceous units into well-sorted, medium to coarse sands of the overlying Folkestone Formation. The boundary is generally sharp, but rarely exposed.
Thickness: 50 to 100m in West Sussex.
Geographical Limits: The Weald of Kent, Sussex, southeast Surrey and eastern Hampshire.
Parent Unit: Lower Greensand Group (LGS)
Previous Name(s): Sandgate Beds (-443)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Partial Type Section  The formation has no single stratotype. Readers should refer to entries for the component members in the western Weald, namely: Bargate Sandstone Member, Rogate Member, Easebourne Member (where present), Selham Ironshot Sands Member, Fittleworth Member, Pulborough Sandrock Member (where present) and Marehill Clay Member (at top). Elsewhere the Formation is undivided. The formation takes its name from Sandgate [TR 20 35] on the coast near Folkestone, both here, around the town itself, and in the West Cliff [TR 235 364] at Folkestone the formation is extensively affected by landslides. The base of the formation was seen in the Goldwell Quarry south of Hothfield in the Maidstone district but this was not designated as a type site. 
Reference(s):
Rawson, P F. 1992. Cretaceous, 355-388 in Duff, P McL D and Smith, A J (editors), Geology of England and Wales. (London: Geological Society.) 
Drew, F. 1864. The geology of the country between Folkestone and Rye, including the whole of Romney Marsh (Sheet 4). Memoir of the Geological Survey of the United Kingdom. 
Young, B and Lake, R D. 1988. Geology of the country around Brighton and Worthing. Memoir of the British Geological Survey, Sheet 318 and 333 (England and Wales). 
Kirkaldy, J F. 1933. The Sandgate Beds of the Western Weald. Proceedings of the Geologists' Association, Vol.44, 270-311. 
Casey, R, 1961. The stratigraphical palaeontology of the Lower Greensand. Palaeontology, Vol.3, 487-621. 
Bristow, C R. 1991. Geology of the Petersfield District, Hampshire. Explanation of 1:10,000 Geological sheets SU72NW, 72NE, 72SW, 72SE, 82NW and 82SW. British Geological Survey Technical Report, WA/91/24. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E285 E286 E287 E288 E289 E300 E301 E305 E318 E319 E333