The BGS Lexicon of Named Rock Units — Result Details
Oakley Marl Member
| Computer Code: | OKY | Preferred Map Code: | Oky |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Tithonian Age (JI) — Tithonian Age (JI) | ||
| Lithological Description: | Variable, but dominantly marls or clays, with thin beds of micritic limestone. | ||
| Definition of Lower Boundary: | Upward change from either dominantly micritic limestones of the Wockley Member, or fine-grained oolites of the Chilmark Member, to marls and clays. In sections, base taken below lowest "Dirt Bed"; in the field, micritic limestone above the Dirt Bed is probably mapped with the underlying Member. | ||
| Definition of Upper Boundary: | Upward change fron a dominantly marly sequence to micritic limestones of the "Middle Purbeck". | ||
| Thickness: | c.5m | ||
| Geographical Limits: | Fonthill Gifford [ST 923 316] eastwards to beyond Chilmark [ST 980 310] (limit of current mapping). | ||
| Parent Unit: | Purbeck Group (PB) | ||
| Previous Name(s): | Lulworth Beds [Obsolete Name And Code: Use LULW]
(LWB)
Lower Purbeck [Obsolete Name and Code: Use OKY] (-2963) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Type Section | Old Oakley (or Wockley, or Shavers Bridge) Quarry, southeast of Tisbury. | ||
| Reference(s): | |||
| Wimbledon, W A. 1980. Portlandian correlation chart. 85-93 in Cope, J C W (Editor), A correlation of the Jurassic rocks of the British Isles. Part Two: Middle and Upper Jurassic. Geological Society of London Special Report, No.15. | |||
| Woodward, H B. 1895. the Jurassic Rocks of Britain. The Middle and Upper Oolitic rocks of England (Yorkshire excepted). Vol.5. Memoir or the Geological Survey of the United Kingdom. | |||
| Andrews W R, and Jukes-Browne, A J. 1894. The Purbeck Beds of the Vale of Wardour. Quart. Journ. Geol. Soc. of London. Vol. 50. 44-71. (In particular, see section on p. 49). | |||
| Reid C. 1903, Geology of the country around Salisbury. Memoir of the Geol. Survey of Great Britain. | |||
| Wimbledon, W A and Cope, J C W. 1978. The ammonite faunas of the English Portland Beds and the zones of the Portlandian Stage. Journal of the Geological Society of London, Vol.135, 183-190. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| none recorded or not applicable | |||