The BGS Lexicon of Named Rock Units — Result Details

Roade Member

Computer Code: ROAD Preferred Map Code: BwL
Status Code: Full
Age range: Bathonian Age (JN) — Bathonian Age (JN)
Lithological Description: A pale grey to off-white or brownish, more or less clayey or sandy shell fragmental, bioturbated wackestone and packstone, characteristically containing Kallirhynchia sharpi (Muir-Wood) and other brachiopods and bivalves such as mussels and oysters with thin marls and mudstones.
Definition of Lower Boundary: The base of the described limestones, overlying mudstones of the Rutland Formation.
Definition of Upper Boundary: Generally a sharp boundary with beds of limestone, marl or mudstone lacking K sharpi,commonly a marl or mudstone bed at this level which may prove a reliable marker compared to the mudstone at the base of the Ardley Member of the White Limestone in Oxon.
Thickness: Typically about 1m thick in the type area, elsewhere from about 3m, foe example the 2.51 m recorded by Torrens, 1967, to 2.99 m measured by Cripps,1986, at the type section.
Geographical Limits: From the Towcester district, Northants (Sheet 202) to the Stamford district (Cripps,1986) passing south- west into the Shipton Member of the White Limestone Formation and north into the Blisworth Limestone Formation which cannot be separated from the Longthorpe Member, notwithstanding the presence of K sharpi in the lower part of the Blisworth Limestone Formation in north Lincolnshire (see Cripps,1986).
Parent Unit: Blisworth Limestone Formation (BWL)
Previous Name(s): Rhynconella Zone (-3004)
Kallirhyncia Sharpi Beds (-1143)
Sharpi Beds (-1791)
Alternative Name(s): none recorded or not applicable
Reference Section  Cranford St John Quarry. Torrens, 1967; Cox, B M, and Sumbler, M G. 2002. 
Type Section  Roade Railway Cutting, near Blisworth. Thompson, 1924; Torrens,1967; Cox, B M, and Sumbler, M G. 2002. 
Thompson, B. 1924. The geology of Roade Cutting. Geological Magazine Vol.61, 210-218. 
Cox, B M and Sumbler, M G. 2002. British Middle Jurassic Stratigraphy. Geological Conservation Review Series No.26. [Peterborough: Joint Nature Conservation Committee.] 
Thompson, B. 1927. Lime Resources of Northamptonshire. (Northampton: Northamptonshire County Council.) 
Torrens, H S, 1967. The Great Oolite Limestone of the Midlands. Transactions of the Leicestershire Literary and Philosophical Society, Vol.61, 65-90. 
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.) 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E157 E158 E171 E185 E186 E202 E203