The BGS Lexicon of Named Rock Units — Result Details

Kellaways Clay Member

Computer Code: KLC Preferred Map Code: KlC
Status Code: Full
Age range: Callovian Age (JC) — Callovian Age (JC)
Lithological Description: Silicate mudstone, grey, commonly smooth in basal part (see Previous Names), but more generally silici-silty or silici-sandy, locally with thin beds of siltstone and sandstone, and nodules of argillaceous limestone.
Definition of Lower Boundary: Generally sharp, conformable or non-sequential junction with bioclastic limestone of the underlying Cornbrash Formation overlain by grey mudstone. Commonly a thin bioclastic unit of shell-fragmental, more or less sandy mudstone occurs at the base (where this is more strongly cemented it is included in the Cornbrash Formation).
Definition of Upper Boundary: Transitional junction; boundary drawn at the base of the lowest substantial sandstone/siltstone unit of the overlying Kellaways Sand Member resting on the predominantly mudstone succession.
Thickness: 0 to perhaps (in south Dorset) c.50m; typically c.20m in the Wessex Basin, and 2 to 3m on the East Midlands Shelf.
Geographical Limits: Dorset coast (Weymouth area) to the Market Weighton High. Extensive in onshore outcrop, though absent over the interior of the London Platform.
Parent Unit: Kellaways Formation (KLB)
Previous Name(s): Kellaways Clay Member Plus Cayton Clay Formation (-2267)
Kellaways Clay (-997)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  Tytherton No.2 Borehole, 28.75 to 44.58m. 
Reference Section  Clay Pits, Yaxley and Fletton (Callomon, 1968, p.277-280). 
Reference Section  BGS Walks Farm Borehole, 2.5km northnortheast of Heckington near Sleaford, Lincolnshire. (TF14NE/18). 96.60 to 98.37m depth. Berridge et al., 1990, p.80. 
Type Area  Area around hamlet of Kellaways, near Chippenham, Wilts. 
Reference Section  BGS Tytherton No.3 Borehole, 3.6km east of Chippenham, Wiltshire. (ST 97 SW/2) 6.95 to 24.27m depth. Full sequence proved. Cave and Cox, 1975. 
Reference(s):
Cave, R and Cox, B M. 1975. The Kellaways Beds of the area between Chippenham and Malmesbury, Wiltshire. Bulletin of the Geological Survey of Great Britain, No.54, 41-46. 
Woodward, H B. 1895. the Jurassic Rocks of Britain. The Middle and Upper Oolitic rocks of England (Yorkshire excepted). Vol.5. Memoir or the Geological Survey of the United Kingdom. 
Berridge, N G, Pattison, J, Samuel, M D A, Brandon, A, Howard, A S, Pharaoh, T C and Riley, N J. 1999. Geology of the Grantham district. Memoir of the British Geological Survey, sheet 127 (England and Wales). 
Arkell W J, 1933. The Jurassic System in Great Britain [Oxford: Clarendon Press.] 
Page, K N. 1989. A stratigraphic revision for the English Lower Callovian. Proceedings of the Geologists' Association, Vol.100, 363-382. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E281 E217 E080 E089 E127 E158 E102 E237 E103 E115 E128 E143 E144 E157 E171 E203 E172 E186 E236 E251 E252 E265 E219