The BGS Lexicon of Named Rock Units — Result Details

Kingston Formation

Computer Code: KTON Preferred Map Code: notEntered
Status Code: Full
Age range: Oxfordian Age (JO) — Oxfordian Age (JO)
Lithological Description: Generally medium-grained quartzose sands, locally fine- and coarse-grained, with carbonate cemented beds and doggers which are sandy limestone or calcareous sandstone; some beds of spiculitic sandstone which are relatively sand-free, shelly and/or ooidal limestone, sandy or silty mudstone, and calcareous mudstone. Strata are generally grey when fresh, weathering to brown or yellow.
Definition of Lower Boundary: East of Cumnor, sharp change up (minor non-sequence) from dominantly muddy strata (West Walton Formation) into dominantly sandy succession. West of Cumnor, gradational change up from poorly fossiliferous fine-grained sand and sandy mudstone (Hazelbury Bryan Formation) into moderately fossiliferous medium- to coarse-grained sand (Beckley Sand Member) or sharp change up into shelly, ooidal or coralliferous limestone, locally with basal conglomerate (Highworth Limestone Member) or mudstone (Highworth Clay Member).
Definition of Upper Boundary: The base of (predominantly non-sandy) limestones of the overlying Stanford Formation, or locally, of the Lower Cretaceous sandstone or mudstone; generally a sharp, non-sequential boundary, commonly marked by a pebble bed.
Thickness: Up to about. 30 m around Oxford, and up to 15 m thick in the Calne-Highworth area.
Geographical Limits: From Calne in Wiltshire, it is overstepped by Lower Cretaceous strata to Boarstall, northeast of Oxford, where it wedges out into the Ancholme Group (Horton et al. 1995).. The greatest development of this unit is between Faringdon and Beckley in Oxfordshire.
Parent Unit: Corallian Group (CR)
Previous Name(s): Lower Calcareous Grit (-101)
Lower Corallian [Obsolete Name And Code: See TECY, BYSA, KTON] (LCR)
Lower Calcareous Grit, Highworth Limestone, Pusey Flags, Highworth Clay and Highworth Grit (-4742)
Beckley Sand, Temple Cowley And Arngrove Spiculite Members (-1634)
Cumnor Formation [Obsolete Name And Code: Use STFD] (CUMR)
Alternative Name(s): none recorded or not applicable
Type Area  The 'Corallian Ridge' between rivers Thames and Ock (Vale of White Horse); approximately Highworth to Oxford. 
Reference Section  British Geological Survey Cumnor (Henwood Farm) Borehole (SP40SE/11), 20.35 m to 45.81 m depth. (Horton, 1978; Horton et al., 1995) 
Reference Section  British Geological Survey Garsington Borehole (SP50SE/49), 21.60 m to 44.82 m depth. (Horton et al., 1995) 
Reference Section  Harwell No 3 (HW3) Borehole (SU48NE/92), 196.80 m to 226.15 m depth. (Gallois and Worssam, 1983). 
Type Section  The Lamb and Flag Inn Quarry, Kingston Bagpuize, Oxon. (Arkell, 1947, p.87; Wright, J K and Cox, B M, 2001). It formerly exposed the Highworth Grit, the Highworth Clay and the Highworth Limestone members, and also possibly the upper part of the Beckley Sand Member of the Kingston Formation. It is now part infilled according to Sheet SU39NE (1969 edition), and Wright and Cox, 2001, and exposes only part of the Highworth Limestone Member. 
Reference Section  Dry Sandford Quarry near Abingdon, Oxon, also known as Cothill Quarry, shows the uppermost 7m of the Kingston Formation, Beckley Sand Member as described by Arkell, 1936; Callomon, 1960; McKerrow and Kennedy, 1973; Wright, J K and Cox, B M, 2001. 
Reference Section  British Geological Survey Uffington (Manor Farm) Borehole (SU38NW/1), 56.08 m to 84.83 m depth. (Poole and Kelk, 1971). 
Wright, J K, 1980. Oxfordian Correlation Chart. "In" Cope, C J W, (Editor). A correlation of Jurassic rocks in the British Isles, Part two: Middle and Upper Jurassic. Geological Society of London Special Report No.15. (p.61-76 in Correlation Chart). 
Wright, J K and Cope, J C W. In press. Oxfordian - Kimmeridgian Correlation Chart. In: A correlation of Jurassic rocks in the British Isles: Middle and Upper Jurassic. Cope, J C W (editor). Special Report of the Geological Society of London. 
Wright, J K, and Cox, B M. 2001. British Upper Jurassic Stratigraphy (Oxfordian to Kimmeridgian). Geological Conservation Review Series. No. 21. (Peterborough: Joint Nature Conservation Committee/Chapman and Hall.) 
Arkell, W J. 1941a. Map of the Corallian Beds around Highworth, Wiltshire. Proceedings of the Geologists' Association, Vol.52, 79-109. 
Arkell, W J. 1951. The geology of the Corallian ridge between Wootton Bassett and Lyneham, Wiltshire. Wiltshire Archaeological and Natural History Magazine, Vol.54, 1-18. 
McKerrow, W S and Kennedy, W J. 1973. The Oxford district. Geologists' Association Guide No.3. 
Arkell, W J, 1927. The Corallian rocks of Oxford, Berkshire and north Wiltshire. Philosophical Transactions of the Royal Society of London, Vol.B216, 67-181. 
Arkell, W J. 1947. The Geology of Oxford. 267pp. [Oxford: Clarendon Press.] 
Arkell, W J. 1936. The ammonite zones of the Upper Oxfordian of Oxford, and the horizons of the Sowerby's and Buckman's types. Quarterly Journal of the Geological Society of London, Vol. 92, 146-187. 
Arkell, W J. 1939. Map of the Corallian Beds between Marcham and Faringdon, Berkshire. Proceedings of the Geologists' Association, Vol.50, 487-509. 
Arkell, W J. 1941b. Map of the Corallian Beds around Purton, Wiltshire. Wiltshire Archaeological and Natural History Magazine, Vol.49, 274-282. 
Callomon, J H. 1960. New sections in the Corallian Beds around Oxford and the subzones of the Plicitalis Zone. Proceedings of the Geologists' Association, Vol. 71, p. 177-208. 
Coe, A L. 1995. A comparison of the Oxfordian successions of Dorset, Oxfordshire and Yorkshire. 151-172 in Taylor, P D (Ed.) Field Geology of the British Jurassic. [Bath: The Geological Society.] 
Gallois, R W and Worssam, B C. 1983. Stratigraphy of the Harwell boreholes. Institute of Geological Sciences Report FLPU 83-14. 
Horton, A. 1978. The Cumnor (Henwood Farm) Borehole. p.4 in Institute of Geological Sciences Boreholes. 1976. Institute of Geological Sciences Report 77/10. 
Horton, A, Sumbler, M G, Cox, B M and Ambrose, K, 1995. Geology of the country around Thame. Memoir of the British Geological Survey, Sheet 237 (England and Wales). 
Poole, E G and Kelk, B. 1971. Calcium montmorillonite (fuller's earth in the Lower Greensand of the Baulking area, Berkshire. Institute of Geological Sciences Report 71/4. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E236 E237 E252 E253 E265