The BGS Lexicon of Named Rock Units — Result Details

Leckhampton Member

Computer Code: LECK Preferred Map Code: Lk
Status Code: Full
Age range: Aalenian Age (JA) — Aalenian Age (JA)
Lithological Description: Grey, weathering yellow-brown, rubbly, highly bioturbated, ferruginous, possibly sideritic), finely shell-detrital, medium-grained peloidal and ooidal sandy muddy limestone, ironshot and very shelly in parts, with thin marl beds, basal bed conglomerate in places. In Wotton-under-Edge area includes 'ironshot' limestones of the Opaliniforme Bed at the base (Richardson, L, 1910).
Definition of Lower Boundary: Disconformity: change upward from Lias Group (mudstone/sand/shelly, ironshot marl and limestone) into the rock types described in the lithological description.
Definition of Upper Boundary: Upward transition from limestones as in lithological description into ooidal shell-detrital grainstone (Crickley Member), or hardground overlain by Salperton Limestone Member.
Thickness: Typically 2 to 6m. Type section; 5.3 to 5.6m. Maximum c.10m (Northleach area).
Geographical Limits: Cotswolds Hills from north Oxfrodshire (near Chipping Norton) to northeast South Gloucestershire District. Absent due to overstep by Salperton Limestone Formation in south Cotswolds and in Vale of Moreton area (see Barron, A J M, 1997, fig.4). Replaced in east Oxfordshire by Northampton Sand Formation (see Horton, A, Poole, E G, Williams, B J, Illing, V C and Hobson, G D, 1987).
Parent Unit: Birdlip Limestone Formation (BLPL)
Previous Name(s): Sandy Limestone (-1646)
Scissum Beds (-1647)
Ferruginous Oolite ('Belemnite Bed') (-358)
Leckhampton Limestone Member (-359)
Ammonite and Belemnite Bed (-1019)
Sandy Ferruginous Beds Or Stone (-1020)
Sandy Ferruginous Limestones (-1645)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  Disused quarries, north-west side of Crickley Hill, Gloucestershire. Beds 1-12 of Mudge, D C, 1978b. See also Ager, D V, 1969. For further reference sections see Barron, A J M, et al, 1997. 
Type Section  Limekiln Quarry at Leckhampton Hill SSSI, Cheltenham; beds 1 to 14 of Mudge, D C, 1978b. See also Brodie (1850, 1851); Wright (1860); Woodward (1894); Richardson (1904, 1906); Gray (1924); Murray (1968); Ager (1969); Mudge (1995); Sumbler and Barron (1996); Cox, B M, and Sumbler, M G. 2002. 
Type Area  Cotswolds Hills, Gloucestershire. 
Reference(s):
Cox, B M and Sumbler, M G. 2002. British Middle Jurassic Stratigraphy. Geological Conservation Review Series No.26. [Peterborough: Joint Nature Conservation Committee.] 
Buckman, S S, 1893. The Bajocian of the Sherborne district: its relation to subjacent and superjacent strata. Quarterly Journal of the Geological Society of London. Vol.49, 479-522. 
Ager, D V, 1969. The Lower and Middle Jurassic rocks of the Cotswold Escarpment and the Vale of Worcester. In (Torrens, H S, ed). Guide for north Somerset and Gloucestershire. International field symposium on the British Jurassic, Excursion No.2, B27-B43. 
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). 
Murray, J W, 1968. The Inferior Oolite of the Cotswold scarp, Wotton-under-Edge to Leckhampton. Proceedings of the Bristol Naturalists' Society, Vol.31, 535-549. 
Brodie, P B, 1850. On certain beds in the Inferior Oolite, near Cheltenham. Quarterly Journal of the Geological Society of London, Vol.6, 239-249. 
Barron, A J M, Sumbler, M G and Morigi, A N, 1997. A revised lithostratigraphy for the Inferior Oolite Group (Middle Jurassic) of the Cotswolds, England. Proceedings of the Geologists' Association, Vol.108, 269-285. 
Richardson, L, 1904. Handbook to the geology of Cheltenham and neighbourhood (Cheltenham: Norman, Sawyer and Co). 
Witchell, E, 1886. On the basement-beds of the Inferior Oolite of Gloucestershire. Quarterly Journal of the Geological Society of London, Vol.42, 264-271. 
Gray, J W, 1924. Leckhampton Hill, Gloucestershire: the Wellington Quarry and other sections. Proceedings of the Cotswold Naturalists' Field Club, Vol.22, 33-42. 
Mudge, D C, 1978. Stratigraphy and sedimentation of the Lower Inferior Oolite of the Cotswolds. Journal of the Geological Society of London, Vol.135, 611-627. 
Mudge, D C, 1995. The Middle Jurassic of the Cotswolds. In (Taylor, P D; ed). Field Geology of the British Jurassic. Geological Society, London, 31-50. 
Richardson, L, 1906. Half-day excursion to Leckhampton Hill, Cheltenham. Proceedings of the Cotswold Naturalists' Field Club, Vol.15, 182-189. 
Sumbler, M G and Barron, A J M, 1996. Day Excursion to the Cotswolds. Mercian Geologist, Vol.14, 34-37. 
Witchell, E, 1882. On the pisolite and the basement beds of the Inferior Oolite of the Cotteswolds. Proceedings of the Cotteswolds Naturalists' Field Club, Vol.8, 35-49. 
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. 
Wright, T, 1860. On the subdivisions of the Inferior Oolite of the south of England, compared with the equivalent beds of that formation on the Yorkshire coast. Quarterly Journal of the Geological Society of London, 16, 1-48. 
Brodie, P B, 1851, On the basement beds of the Inferior Oolite in Gloucestershire. Quarterly Journal of the Geological Society of London, Vol.7, 208-212. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E217 E235