The BGS Lexicon of Named Rock Units — Result Details

Aston Limestone Formation

Computer Code: ASLS Preferred Map Code: AsL
Status Code: Full
Age range: Bajocian Age (JB) — Bajocian Age (JB)
Lithological Description: Grey and brown variously shelly, ooidal, sandy, shell-detrital and bioturbated limestones; rubbly in parts, with sandy and shell-detrital marl beds. Component members: Lower Trigonia Grit, Gryphite Grit, Notgrove, Rolling Bank.
Definition of Lower Boundary: Disconformity: upward change from ooidal and peloidal limestone (Scottsquar Member) or sand, mudstone and sandy limestone (Harford Member) into limestone as in lithological description. Generally marked by a hardground.
Definition of Upper Boundary: Disconformity: hardground: limestone as in lithological description, overlain by Salperton Limestone Formation.
Thickness: Type section up to about 6.45m. Maximum c.22m (Cleeve Hill area).
Geographical Limits: North and mid-Cotswolds: west of Northleach, Cold Aston and Blockley, and northeast of Stroud, Gloucestershire. Present locally outside this area to the south of Cold Aston, and absent between Birdlip and Cirencester ('Birdlip Anticline'). (Barron, A J M, et al, 1997, fig.4).
Parent Unit: Inferior Oolite Group (INO)
Previous Name(s): Hartley Hill Formation (-1958)
Middle Inferior Oolite [Obsolete Name And Code: Use ASLS] (MINO)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Cleeve Hill, Gloucestershire. Buckman, J, 1897; Richardson, L, 1929; Barron, A J M, 1999. 
Type Section  Harford railway cutting SSSI. Buckman, J, 1887, sections 3 and 4; Richardson, L, 1929; Parsons, C F, 1976; British Geological Survey files [BA 91]; Cox, B M, and Sumbler, M G. 2002. 
Reference Section  'Tumulus' railway cutting, Chedworth Woods, Gloucestershire. Buckman, J, 1895; Richardson, L, 1933, pp.27-28; Sumbler, M G and Barron, A J M, 1995, appendix 1, locality A. For further reference sections see Barron, A J M, et al, 1997. 
Reference(s):
Buckman, S S, 1905. A monograph of the ammonites of the Inferior Oolite Series, Pt.13, Supplement pp.clxix-ccix. 
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. 
Buckman, S S, 1887. The Inferior ooilte between Andoversford and Bourton-on-the-Water. Proceedings of the Cotteswold Naturalists' Field Club, Vol.9, 108-135. 
Buckman, S S, 1895. The Bajocian of the mid-Cotswolds. Quarterly Journal of the Geological Society of London, Vol.51, 388-445; 458-462. 
Buckman, S S, 1897. Deposits of the Bajocian age in the northern Cotswolds: the Cleeve Hill Plateau. Quarterly Journal of the Geological Society of London, Vol.53, 607-629. 
Buckman, S S, 1901. Bajocian and contiguous deposits in the north Cotswolds: the main hill-mass. Quarterly Journal of the Geological Society of London, Vol.57, 126-155. 
Parsons, C F, 1976. Ammonite evidence for dating some Inferior Oolite sections in the North Cotswolds. Proceedings of the Geologists' Association, 87, 45-63. 
Parsons, C F, 1980. Aspects of the statigraphy and ammonite faunas of the Aaenian-Bajocian stages in Great Britain. Unpublished PhD thesis, University of Keele. 
Sumbler, M G and Barron, A J M, 1995. Geological notes and local details for 1: 10 000 Sheet SP01SE (Chedworth). British Geological Survey Technical Report, WA/95/73. 
Cox, B M and Sumbler, M G. 2002. British Middle Jurassic Stratigraphy. Geological Conservation Review Series No.26. [Peterborough: Joint Nature Conservation Committee.] 
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. 1929. The Country around Moreton in Marsh. Memoir of the Geological Survey of Great Britain, Sheet 217 (England and Wales). 
Richardson, L. 1933. The Country around Cirencester. Memoir of the Geological Survey of Great Britain, Sheet 235 (England and Wales). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E234 E235 E217