The BGS Lexicon of Named Rock Units — Result Details

Blisworth Limestone Formation

Computer Code: BWL Preferred Map Code: BwL
Status Code: Full
Age range: Bathonian Age (JN) — Bathonian Age (JN)
Lithological Description: Pale grey to off-white or yellowish limestones with thin marls and mudstones, fossiliferous, bioturbated peloidal, ooidal and shell-fragmental more-or-less argillaceous packstones and wackestones, subordinate cross-bedded ooidal shell-fragmental grainstones: fauna may include rhynchonellids particularly in the lower part in the south (see the Roade Member), and may be dominated by oysters, notably in the upper part in the north (see the Longthorpe Member).
Definition of Lower Boundary: The base of the limestones overlying mudstones of the Rutland Formation.
Definition of Upper Boundary: Generally a sharp boundary of the limestones with mudstone, or locally an erosive contact with cross-bedded shell-fragmental ooidal limestone, both of the Blisworth Clay Formation.
Thickness: Typically from 6 m to 7m thick in the type area, up to about 12m to the south-west, and 4m thick at Ketton.
Geographical Limits: Towcester district, Northants to Brigg, north Lincolnshire, passes south-west into the Shipton and Ardley members of the White Limestone Formation and to the north by intercalation into the marls and mudstones of the Rutland Formation.
Parent Unit: Great Oolite Group (GOG)
Previous Name(s): White Limestone (WLM)
Snitterby Limestone Formation [Obsolete Name And Code: Use BWL] (SNL)
Great Oolite Limestone [Obsolete Name And Code: Use BWL, GOG or CFDO] (GOL)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Blisworth area, Northants, between Towcester and Northampton. 
Reference Section  Primary reference section: Roade Railway Cutting, near Blisworth. Thompson,1924; Torrens,1967; Cox, B M, and Sumbler, M G. 2002. 
Reference Section  Ketton Quarry, near Stamford Lincolnshire Cripps,1986; Hudson and Clements, 2007; Cox, B M, and Sumbler, M G. 2002. 
Type Section  Blisworth Rectory Farm Quarry. Sharp,1870; Woodward,1894; Torrens,1967 (incorrect NGR); Cox, B M, and Sumbler, M G. 2002. 
Reference(s):
Woodward, H B, 1894. The Jurassic Rocks of Britain, Vol.4. The Lower Oolitic Rocks of England (Yorkshire excepted). Memoir of the Geological Survey of the United Kingdom. 
Cox, B M and Sumbler, M G. 2002. British Middle Jurassic Stratigraphy. Geological Conservation Review Series No.26. [Peterborough: Joint Nature Conservation Committee.] 
Judd, J W. 1875. The geology of Rutland and parts of Lincoln, Leicester, Northampton, Huntingdon and Cambridge. Memoir of the Geological Survey of Great Britain (Old Series sheet 64). 
Sharp, S. 1870. The Oolites of Northamptonshire, Part 1. Quarterly Journal of the Geological Society of London, Vol. 26, 354-391. 
Horton, A, Lake, R D, Bisson, G and Coppack, B C, 1974. The geology of Peterborough. Report of the Institute of Geological Science, No.73/12. 
Torrens, H S, 1967. The Great Oolite Limestone of the Midlands. Transactions of the Leicestershire Literary and Philosophical Society, Vol.61, 65-90. 
Torrens, H S. 1968. The Great Oolite Series. 227-263 in Sylvester-Bradley, P C and Ford, T D (editors), The geology of the East Midlands. (Leicester: Leicester University Press.) 
Cripps, D W. 1986. A facies analysis of Upper Great Oolite Group in Central and Eastern England. (University of Aston in Birmingham: Unpublished PhD thesis.) 
Hains, B A and Horton, A.1969. British Regional Geology: Central England. 3rd edition. (London: HMSO). 
Hudson, J D and Clements, R G. 2007. The Middle Jurassic Succession at Ketton, Rutland. Proceedings of the Geologists' Association, Vol 118, 239-264. 
Thompson, B. 1924. The geology of Roade Cutting. Geological Magazine Vol.61, 210-218. 
Horton, A, Shephard-Thorn, E R and Thurell, R G, 1974. The Geology of the new town of Milton Keynes. Report of the Institute of Geological Sciences, No 74/16. 
Gaunt, G D, Fletcher, T P and Wood, C J. 1992. Geology of the country around Kingston upon Hull and Brigg. Memoir of the British Geological Survey, sheets 80 and 89 (England and Wales). 172pp. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E102 E114 E115 E127 E128 E143 E144 E157 E158 E159 E171 E172 E175 E185 E186 E187 E188 E189 E202 E203 E220 E080 E089