The BGS Lexicon of Named Rock Units — Result Details

Camberley Sand Formation

Computer Code: CMBS Preferred Map Code: notEntered
Status Code: Full
Age range: Lutetian Age (GL) — Lutetian Age (GL)
Lithological Description: The Camberley Sand Formation comprises a fairly uniform sequence of homogeneous, bioturbated, yellow-brown, sparsely to moderately glauconitic silty fine-grained sand, or sandy silt, with some ironstone concretions and masses of white sandstone. Sporadic flint gravel or a gravel bed occur near the base. Thin beds of pale grey clay occur in places (Ellison and Williamson, 1999). Fossils include fish teeth and marine bivalve molluscs, although occurrences above the water table generally have been decalcified (Curry, 1958). Some beds rich in foraminifera occur in the BGS Mytchett Borehole (SU85NE184) [SU 8830 5541].
Definition of Lower Boundary: The base of the Camberley Sand Formation is probably an omission surface marking the upwards change from the heterogeneous Windlesham Formation to the more homogeneous, paler-coloured Camberley Sand Formation.
Definition of Upper Boundary: The Camberley Sand is the youngest Palaeogene unit in the London Basin, so it is overlain, if at all, only by deposits of Quaternary age.
Thickness: Up to 69m in the Windsor district (Ellison and Williamson, 1999).
Geographical Limits: The Camberley Sand Formation occurs in the core of the western London Basin around the junction of Surrey, Berkshire and Hampshire.
Parent Unit: Bracklesham Group (BRB)
Previous Name(s): Barton Beds (-665)
Upper Bagshot Sands (-5085)
Upper Bagshot Beds [Obsolete Name And Code] (BGBU)
Alternative Name(s): Selsey Formation [Obsolete: use SLSY]
Stratotypes:
Reference Section  The BGS Mytchett (Farnborough) Borehole 1 (SU85NE184) between 6.6 and 41.86m depth (Ellison et al., 2002, fig. 6). 
Reference Section  The BGS Bracknell Borehole (SU86NE42) between 1.77 and about 16.2m (Ellison and Williamson, 1999, fig. 6). 
Reference(s):
King, C. in prep. A revised correlation of Palaeogene and Neogene deposits in the British Isles. Geological Society of London Special Report. 
Ellison, R.A., Williamson, I.T., Humpage, A., 2002. Geology of the Guildford district - a brief explanation of the geological map. Sheet Explanation of the British Geological Survey 1:50 000 Sheet 285 Guildford (England and Wales). 
Gardner, J S, Keeping, H and Monckton, H W, 1988. The Upper Eocene, comprising the Barton and Upper Bagshot Formations. Quarterly Journal of the Geological Society, Vol.44, p.578-635. 
Aldiss, D T. 2012. The stratigraphical framework for the Palaeogene successions of the London Basin, UK. British Geological Survey Open Report OR/12/004. 
Waters, C N, Smith, K, Hopson, P M, Wilson, D, Bridge, D M, Carney, J N, Cooper, A H, Crofts, R G, Ellison, R A, Mathers, S J, Moorlock, B S P, Scrivener, R C, McMillan, A A, Ambrose, K, Barclay, W J, and Barron, A J M. 2007. Stratigraphical Chart of the United Kingdom: Southern Britain. British Geological Survey, 1 poster. 
Dewey, H, and Bromehead, C E N. 1915. The geology of the country around Windsor and Chertsey. Memoir of the Geological Survey of Great Britain, Sheet 269 (England and Wales). 
Curry, D. 1958. Part 3a XII Palaeogene. Lexique Stratigraphique International. Whittard, W F, and Simpson, S (editors). Vol. 1 Europe (Paris: Centre Nationale de la Research Scientifique.) 
Ellison, R A and Williamson, I T. 1999. Geology of the Windsor and Bracknell district - a brief explanation of the geological map. Sheet Explanation of the British Geological Survey. 1:50 000 Sheet 269 Windsor (England and Wales). 
Prestwich, J, 1847. On the main points of structure and the probable age of the Bagshot Sands and on their presumed equivalents in Hampshire and France. Quarterly Journal of the Geological Society, Vol.3, p.378-409. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E268 E269 E285