The BGS Lexicon of Named Rock Units — Result Details
Bladon Member
| Computer Code: | BLAD | Preferred Map Code: | BI |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Bathonian Age (JN) — Bathonian Age (JN) | ||
| Lithological Description: | A green and grey clay/mudstone, commonly lignitic and associated with fossiliferous marl of the Fimbriata-Waltoni Bed, succeeded by limestones of the Upper Epithyris Bed, including pale grey to white, more or less fossiliferous micrites, peloidal and shell fragmental marly wackestones or packstones, and minor ooidal grainstones. | ||
| Definition of Lower Boundary: | The base of the clay/mudstone marl of the Fimbriata-Waltoni Bed, or more rarely the limestone of the Upper Epithyris Bed where channelled through the Fimbriata-Waltoni Bed,as described in lthe lithological details, in most cases resting sharply on the eroded hardground top surface of pale grey to white wackestone of the Ardley Member of the White Limestone Formation. | ||
| Definition of Upper Boundary: | A generally sharp, erosive boundary with cross-bedded shell-fragmental ooidal limestone or mudstone of the Forest Marble Formation. | ||
| Thickness: | Up to about 4m thickness. | ||
| Geographical Limits: | Around Burford, Oxon, the unit passes westward into the Signet Member of the White Limestone Formation, north eastwood to the Brackley area where it passes into the lower part of the Blisworth Clay. Restricted to 1:50 000 Sheets 218, 219, 236 and 237. | ||
| Parent Unit: | White Limestone Formation (WHL) | ||
| Previous Name(s): | Fimbriata-Waltoni Bed (sensu lato) and Upper Epithyris Bed [Obsolete Name and Code: Use BLAD]
(-1988)
Kemble Beds [Obsolete Name And Code: See BLAD And SI] (KEB) Forest Marble Formation (FMB) Bladon Beds and Kemble Beds [Obsolete Name and Code: Use BLAD] (-2615) Forest Marble Formation (FMB) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Type Section | Shipton-on-Cherwell Quarry. Arkell, 1931; Allen and Kaye, 1973; Richardson et al., 1946; Barker, 1976; Palmer, 1979; Sumbler, 1984; Cox and Sumbler, 2002. | ||
| Reference Section | Kirtlington Quarry. Primary reference section. Arkell, W J; 1931, 1947; Richardson et al., 1946; Barker, 1976; McKerrow et al., 1969. See Sumbler (1984) for additional reference sections. | ||
| Type Area | Cherwell Valley,north of Oxford (Woodstock to Ardley). Palmer, 1979. | ||
| Reference(s): | |||
| Arkell, W J. 1931. The Upper Great Oolite, Bradford Beds and Forest Marble of south Oxfordshire, and the succession of gastropod faunas in the Great Oolite. Quarterly Journal of the Geological Society of London, Vol. 87, 563-629. | |||
| Palmer, T J, 1979. The Hampen Marly and White Limestone formations: Florida-type carbonate lagoons in the Jurassic of central England. Palaeontology, Vol.22, 189-228. | |||
| Sumbler, M G, 1984. The stratigraphy of the Bathonian White Limestone and Forest Marble formations of Oxfordshire. Proceedings of the Geologists' Association, Vol.95, 51-64. | |||
| Allen, J R L, and Kaye, P. 1963. Sedimentary facies of the Forest Marble (Bathonian) Shipton-on-Cherwell Quarry, Oxfordshire. Geological Magazine, Vol. 110, 153-163. | |||
| Barker, M J. 1976. A stratigraphical, palaeoecological and biometrical study of some English Bathonian gastropoda (especially Nerinacea). (University of Keele: Unpublished PhD thesis). | |||
| McKerrow, W S, Johnson, R T and Jakobson, M E, 1969. Palaeoecological studies in the Great Oolite Group at Kirtlington, Oxfordshire, Palaeontology, Vol.12, 56-83. | |||
| Richardson, L, Arkell, W J and Dines, H G. 1946. Geology of the country around Witney. Memoir of the Geological Survey of Great Britain. Sheet 236 ( England and Wales). | |||
| 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. 1947. The Geology of Oxford. 267pp. (Oxford: Clarendon Press.) | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| E219 E218 E236 E237 | |||