The BGS Lexicon of Named Rock Units — Result Details

Lenthay Limestone Bed

Computer Code: LEN Preferred Map Code: Len
Status Code: Full
Age range: Bathonian Age (JN) — Bathonian Age (JN)
Lithological Description: Micritic limestone with a shelly and argillaceous base and an extensively bioturbated and argillaceous top. Contains abundant Sphaeroidothyris lenthayensis.
Definition of Lower Boundary: Transition from shell-detrital mudstone to shelly argillaceous limestone.
Definition of Upper Boundary: Transition to calcareous mudstone from argillaceous limestone.
Thickness: 0 - c.1m; 0.32m in Purse Caundle Borehole.
Geographical Limits: Lenthay Common, west of Sherborne, to c.1km northwest of Milborne Port.
Parent Unit: Lower Fuller's Earth Member (LFE)
Previous Name(s): Sphaeroidothyris Bed (-2897)
Lenthay Bed (-2288)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  Housing Estate, Lenthay Common. Foundation and drainage trenches on Lenthay Common, exposed 1967 (Torrens, 1968) 
Type Section  Lenthay Common. Bomb crater (1940) on the west side of Lenthay Copse, Lenthay Common, (Fowler, 1957). 
Reference Section  BGS Purse Caundle Borehole (ST71NW/7) (Barton and others, 1993) (89.13 to 89.45m depth). 
Reference(s):
Barton C M, 1989. Geology of the Milborne Port district (Somerset and Dorset) 1:10 000 Sheet ST61NE. Technical Report of the British Geological Survey, Onshore Geology Series, WA/89/60 
Torrens, H S, 1968. 'Geology'. "In" Dorset Natural History Reports 1967. Proceedings of the Dorset Natural History and Archaeological Society, Vol.89, p.42. 
Cope, J C W (Editor) 1980b. A correlation of Jurassic rocks in the British Isles. Part Two: Middle and Upper Jurassic. Geological Society of London Special Report, No.15 
Fowler, J, 1957. The geology of the Thornford pipe-trench. Proceedings of the Dorset Natural History and Archaeological Society, Vol.78, p.51-57. 
Barton, C M, Ivimey-Cook, H C, Lott, G K, and Taylor, R T. 1993. The Purse Caundle Borehole, Dorset: stratigraphy and sedimentology of the Inferior Oolite and Fuller's Earth in the Sherborne area of the Wessex Basin. British Geological Survey Research Report, SA/92/01. 
Bristow, C R, Barton, C M, Freshney, E C, Wood, C J, Evans, D J, Cox, B M, Ivimey-Cook, H C, and Taylor, R T. 1995. Geology of the country around Shaftesbury. Memoir of the British Geological Survey, Sheet 313 (England and Wales). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E313