The BGS Lexicon of Named Rock Units — Result Details

Taynton Limestone Formation

Computer Code: TY Preferred Map Code: Ty
Status Code: Full
Age range: Bathonian Age (JN) — Bathonian Age (JN)
Lithological Description: White to pale brown, typically well-sorted medium- to coarse-grained, moderately to highly shell-detrital ooidal grainstone, locally fine- to very coarse-grained; medium to thickly well-bedded and cross-bedded, with thin shell-detrital calcilutite beds and locally calcareous sandstone beds.
Definition of Lower Boundary: Top of highest significant mudstone in Fuller's Earth Formation or Sharp's Hill Formation, or passage from finer grained limestone of the Eyford Member, where present, into medium- to coarse-grained, bioclastic ooidal grainstone.
Definition of Upper Boundary: Passage upwards from medium- to coarse-grained, bioclastic ooidal grainstone into fine-grained ooidal limestone and marls of Hampen Formation or mudstone, siltstone and limestone of the Rutland Formation.
Thickness: 0-11m, locally possibly up to 15m, type area 6 to 8m
Geographical Limits: From Stroud, Gloucestershire (where passes westwards near Stroud into finer grained limestones of Througham Member (Fuller's Earth Formation) and succeeding Hampen Formation (Sumbler, Barron and Morigi, 2000), to Brackley, Northants where passes northeast into Wellingborough Member (formerly Upper Estuarine Limestone) of the Rutland Formation (Horton et al, 1987)). Present at depth in the Weald (Wyatt, 2011).
Parent Unit: Great Oolite Group (GOG)
Previous Name(s): Taynton Stone (-4944)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Lee's Quarry, Taynton Down, Oxfordshire, exposes over 7 m of the formation in typical cross-bedded bioclast- and ooid-grainstone facies in thick sets separated by thin calcareous mudstone beds, overlain by the Hampen Formation; the base is not exposed. Sumbler, M G and Williamson, I T. 1998. 
Reference Section  Farmington Quarry, Gloucestershire, in three disconnected sections exposes up to 7 m of the formation in typical cross-bedded bioclast- and ooid-grainstone facies; top overlain by the Hampen Formation seen; the base is not exposed. Sumbler, M G, 1995. 
Reference Section  Hampen Railway Cutting, exposes the full thickness of the formation in typical facies, plus the ‘Rhynchonella Bed’, ‘Ostrea Acuminata Limestones’ and ‘Sevenhampton Marl’ of Richardson (1929), in total 4.08 m thick, resting on the Fuller’s Earth Formation and overlain by the Hampen Formation. Barron, A J M, 1998. 
Reference(s):
Barron, A J M, 1998. Geology of the Hawling area: 1:10 000 Sheet SP02SE. British Geological Survey Technical Report WA/98/26. 
Sumbler, M G and Williamson, I T. 1998. Lee's Quarry Taynton: a type locality for the Taynton Limestone Formation (Middle Jurassic, Great Oolite Group). Proceedings of the Cotteswold Naturalists' Field Club, Vol. 41 (2), p. 222 - 229. 
Sumbler, M G, 1995. Geological notes and local details for 1:10 000 Sheet SP11NW (Farmington). British Geological Survey Technical Report WA/95/3. 
Sumbler, M G, Barron, A J M and Morigi, A N, 2000. Geology of the Cirencester district. Memoir of the British Geological Survey, Sheet 235 (England and Wales). 
McKerrow, W S and Kennedy, W J. 1973. The Oxford district. Geologists' Association Guide No.3. 
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. 
Sumbler, M G. 1999. Correlation of the Bathonian (Middle Jurassic) succession in the Minchinhampton-Burford district: a critique of Wyatt (1996). Proceedings of the Geologists' Association, Vol. 110, 53-64. 
Cox, B M and Sumbler, M G. in press. Bathonian-Callovian Correlation chart. in Wright, J K and Cox, B M (editors), A correlation of Jurassic rocks in the British Isles: Middle and Upper Jurassic. Special report of the Geological Society of London. 
Horton, A, Poole, E G, Williams, B J, Illing, V C and Hobson, G D. 1987. Geology of the country around Chipping Norton. Memoir of the British Geological Survey, Sheet 218 (England and Wales). 
Wyatt, R J. 2011. A gamma-ray correlation of boreholes and oil wells in the Bathonian Stage succession (Middle Jurassic) of the Wealden Shelf subcrop. British Geological Survey Open Report, OR/11/048. 
Wyatt, R J. 1996. A correlation of the Bathonian (Middle Jurassic) succession between Bath and Burford, and its relation to that near Oxford. Proceedings of the Geologists' Association, Vol. 107, 299-322. 
Arkell, W J and Donovan, D T. 1952. The Fuller's Earth of the Cotswolds and its relation to the Great Oolite. Quarterly Journal of the Geological Society of London, Vol.107, 227-253. 
Boneham, B F W and Wyatt, R J, 1993. Stratigraphical position of the Middle Jurassic (Bathonian) Stonesfield Slate. Proceedings of the Geologists' Association, Vol.104, part 2, 123-136. 
Buckland, W. 1818. Order of the superposition of strata. Outline of the geology of England and Wales. Phillips, W (editor). (London.) 
Barron, A J M, Lott, G K, and Riding, J B. 2012. Stratigraphical framework for the Middle Jurassic strata of Great Britain and the adjoining continental shelf. British Geological Survey Research Report RR/11/06. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E235 E236 E237 E252 E219 E217