The BGS Lexicon of Named Rock Units — Result Details

Woburn Sands Formation

Computer Code: WBS Preferred Map Code: WbS
Status Code: Full
Age range: Aptian Age (KP) — Albian Age (KA)
Lithological Description: Sandstone (or loose sand). Fine- to coarse-grained rounded marine quartz sand, glauconitic in part. Commonly silty with few clay wisps or seams. Locally clean silver sands. Locally cemented to iron pan or gritty carstone. Cross-bedded. Some pebbles and phosphatic nodules to base. Typically grey or greenish grey weathering to ochreous yellow-brown. Minor lignite and pyrite. Local developments of fuller's earth. Commonly barren but nodule layers to base fossiliferous as at Upware and Brickhill.
Definition of Lower Boundary: The base is an unconformity with the Woburn Sands Formation overlying Jurassic or older strata in boreholes. Jurassic strata comprise predominantly mudstones such as the Kimmeridge Clay, Ampthill Clay and Oxford Clay.
Definition of Upper Boundary: The top is an unconformity with the formation overlapped by grey mudstone of the Gault Formation and locally overlain by the so called "Junction Beds" a term applied by Shephard-Thorn et al. (1994) to include the Shenley Limestone (pale brown phosphatic limestone), which passes laterally into glauconitic sandy marl (calcareous mudstones) with "carstone" (ferruginous sandstone) fragments and gritty quartz sand with "carstone" and "boxstone" fragments.
Thickness: To 120m. Rapid variation, resulting from uneven underlying topography and pre-Gault Formation erosion. Thins to southeast on to London Platform. 85m proved at Woburn, 60m proved east of Leighton Buzzard. Absent west of Leighton Buzzard.
Geographical Limits: Outcrop Leighton Buzzard to Cambridge through Bedfordshire, Buckinghamshire and Cambridgeshire. In the area of the "Bedfordshire Straits" linking the Weald Basin (Folkestone Formation and Sandgate Formation) in the south to Eastern England Shelf (Carstone Formation and Sutterby Formation) in the north.
Parent Unit: Lower Greensand Group (LGS)
Previous Name(s): Leighton Buzzard Sands (-600)
Lower Greensand (-1024)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  Clophill Quarry [ TL 0800 3800] 
Reference Section  Description of Gault-Woburn Sands Junction in the Hitchin (221) district (Hopson, 1992). Arlesey Brickpit Borehole TL13SE/45, 72.96 - 83.49m depth. 
Type Area  Type area around Woburn district from Clophill [TL 08 38] to Leighton Buzzard [SP 91 25]. No single section illustrates the complete lithological variation. 
Type Section  Disused fuller's earth workings centred around [SP 930 340] (now mostly backfilled) between Woburn Sands to the northwest and Woburn to the southeast. 
Reference Section  Mundays Hill Quarry [SP 937 282] and contiguous Nine Acre Pit [SP 940 277] 
Reference Section  Ascot Farm Sand Pit [SP 9090 2405]. 
Reference Section  Fuller's Earth Pit at Old Wavendon Heath [SP 932 345]. (Composite: described in Shephard-Thorn and others, 1993). 
Reference(s):
Kirkaldy, J F. 1963. The Wealden and marine Lower Cretaceous beds of England. Proceedings of the Geologists' Association, Vol.74, 127-146. 
Hancock, J M (Editor). 1972. Cretace. Ecosse, Angleterre, Pays de Galles. Lexique Stratigraphique International, Vol.1, fascicule 3a XI. 
Shepard-Thorn, E R, Moorlock, B S P, Cox, B M, Allsop, J M and Wood, C J. 1994. Geology of the country around Leighton Buzzard. Memoir of the British Geological Survey, Sheet 220 (England and Wales). 
Eyers, J. 1995. Correlation of the Lower Greensand Group (Woburn Sands and Carstone) of the Bedfordshire Province, England. Cretaceous Research, Vol.16, 385-413. 
Cameron, A C G. 1892. The Fuller's Earth Mining Co. at Woburn Sands. Geological Magazine, Vol.29, p.469. 
Eyers, J. 1991. The influence of tectonics on early Cretaceous sedimentation in Bedfordshire, England. Journal of the Geological Society of London, Vol. 149, 405-414. 
Hopson, P M. 1992. Geology of the Letchworth, Northwest Hitchin and Holwell district, Hertfordshire. 1:10 000 Sheets TL 13SE and TL 23 SW. British Geological Survey Technical Report, WA/92/42. 
Casey, R, 1961. The stratigraphical palaeontology of the Lower Greensand. Palaeontology, Vol.3, 487-621. 
Edmonds, E A and Dineham, C H. 1965. Geology of the country around Huntingdon and Biggleswade. Memoir of the British Geological Survey. Sheets 187 and 204 (England and Wales). 
Rawson, P F, Curry, D, Dilley, F C, Hancock, J M, Kennedy, W J, Neale, J W, Wood, C J and Worrsam, B C. 1978. A correlation of Cretaceous rocks in the British Isles. Geological Society of London, Special Report No.9. 
Kirkaldy, J F. 1939. The history of the Lower Cretaceous period in England. Proceedings of the Geologists' Association, Vol.50, 379-417. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E203 E220 E221