The BGS Lexicon of Named Rock Units — Result Details

Crickley Member

Computer Code: CRKY Preferred Map Code: Cr
Status Code: Full
Age range: Aalenian Age (JA) — Aalenian Age (JA)
Lithological Description: Pale grey to yellowish brown limestones; lower part dominated by medium- to coarse-grained ooidal shell-fragmental grainstone ('Lower Limestone'), passing up into rubbly, poorly sorted, shelly, shell-detrital, moderately to highly pisoidal grainstones and packstones ('Pea Grit') with thin marl beds. South of Painswick, the succession is apparently replaced by ooidal grainstones comprising the Frocester Hill Oolite and Selsey Hill Oolite of Mudge, D C, 1978a, but the relationship between these strata and the type Crickley Member is uncertain.
Definition of Lower Boundary: Upward transition from ferruginous, bioturbated, sandy, muddy shell-detrital limestone (Leckhampton Member) into limestones as described in lithology.
Definition of Upper Boundary: Upward gradation from pisoidal limestones as described in lithology, into ooidal grainstones (Cleeve Cloud Member) in mid and north Cotswolds; a non-sequence marked by a hardground in southern Cotswolds (Mudge, D C, 1978a).
Thickness: Typically about 7m. Type section (Crickley Hill); c.15.7m, probably the maximum (Ager, D V, 1969).
Geographical Limits: Mid-Cotswolds. Absent east of Northleach, and in north Cotswolds due to overstep by (or passage into) lower part of Cleeve Cloud Member. Southern limit somewhat uncertain, (see Barron, A J M, et al, 1997, fig.4).
Parent Unit: Birdlip Limestone Formation (BLPL)
Previous Name(s): Frocester Hill Oolite And Selsey Hill Oolite (-3937)
Lower Limestone And Pea Grit (-2116)
Crickley Limestone And Crickley Oncolite (-3327)
Pea Grit Series (-165)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Cheltenham area. For further reference sections see Barron et al., 1997. 
Reference Section  Disused quarries, Cleeve Cloud, Cheltenham, Gloucestershire. Wethered, E, 1891; Richardson, L, 1929, beds 2 to 16; Mudge, D C, 1978b, beds 16 to 20; Mudge, D C, 1995; Barron, A J M, 1999; Cox, B M, and Sumbler, M G. 2002. 
Type Section  Quarry on northwest side of Crickley Hill and 'cliff' sections to south; 'Lower Limestone' plus 'Pea Grit' of Ager, D V, 1969; beds 13 to 39 of Mudge, D C, 1978b. See also Brodie, P B, 1850, 1851; Wright, T, 1860; Woodward, H B, 1894; Richardson, L, 1904, 1906; Gray, J W, 1924; Murray, J W, 1968 and Mudge, D C, 1995. 
Reference(s):
Barron, A J M, 1999. Geology of the Bishop's Cleeve area (1:10 000 Sheet SO92NE). British Geological Survey Technical Report WA/99/01. 
Richardson, L, 1906. Half-day excursion to Leckhampton Hill, Cheltenham. Proceedings of the Cotswold Naturalists' Field Club, Vol.15, 182-189. 
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. 
Cox, B M and Sumbler, M G. 2002. British Middle Jurassic Stratigraphy. Geological Conservation Review Series No.26. [Peterborough: Joint Nature Conservation Committee.] 
Arkell W J, 1933. The Jurassic System in Great Britain [Oxford: Clarendon Press.] 
Gray, J W, 1924. Leckhampton Hill, Gloucestershire: the Wellington Quarry and other sections. Proceedings of the Cotswold Naturalists' Field Club, Vol.22, 33-42. 
Richardson, L. 1929. The Country around Moreton in Marsh. Memoir of the Geological Survey of Great Britain, Sheet 217 (England and Wales). 
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. 
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. 
Wethered, E, 1891. The Inferior Oolite of the Cotteswold Hills, with special reference to its microscopical structure. Quarterly Journal of the Geological Society of London, Vol.47, 550-570. 
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. 
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. 
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. 
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. 
Richardson, L, 1904. Handbook to the geology of Cheltenham and neighbourhood (Cheltenham: Norman, Sawyer and Co). 
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. 
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. 
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:
E235 E217