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 (-997)
Kellaways Clay Member Plus Cayton Clay Formation (-2267)
Alternative Name(s): none recorded or not applicable
Stratotypes:
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 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. 
Reference(s):
Arkell W J, 1933. The Jurassic System in Great Britain [Oxford: Clarendon Press.] 
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). 
Page, K N. 1989. A stratigraphic revision for the English Lower Callovian. Proceedings of the Geologists' Association, Vol.100, 363-382. 
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. 
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