The BGS Lexicon of Named Rock Units — Result Details
Westbury Formation
| Computer Code: | WBY | Preferred Map Code: | Wby |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Rhaetian Age (TR) — Rhaetian Age (TR) | ||
| Lithological Description: | Dark grey mudstones or shales with subordinate thin limestones, sandstones and fossiferous arenaceous units ('bone beds'). | ||
| Definition of Lower Boundary: | Usually non-sequential with underlying Blue Anchor Formation, locally transitional. | ||
| Definition of Upper Boundary: | Placed at locally transitional junction with overlying Cotham Member of the Lilstock Formation. | ||
| Thickness: | 5-10m | ||
| Geographical Limits: | Present throughout United Kingdom outcrop area. | ||
| Parent Unit: | Penarth Group (PNG) | ||
| Previous Name(s): | Contorta Shales [Obsolete Name and Code: Use WBY]
(-1910)
Lower Rhaetic [Obsolete Name and Code: Use WBY, PNG] (-2374) Westbury Beds (-601) Black Shales [Obsolete Name and Code: Use WBY] (-4390) Rhaetic, Lower [Obsolete Name And Code: Use WBY Or PNG] (LRRH) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Reference Section | Coastal section north of Lavernock Point, south Glamorgan. | ||
| Type Area | Village of Westbury-on-Severn, Gloucestershire. | ||
| Reference Section | Coastal section, St Mary's Well Bay, Penarth, South Glamorgan. | ||
| Reference(s): | |||
| Warrington, G, Audley-Charles, M G, Elliott, R E, Evans, W B, Ivimey-Cook, H C, Kent, P E, Robinson, P L, Shotton, F W and Taylor, F M. 1980. A correlation of the Triassic rocks in the British Isles. Special Report of the Geological Society of London, No.13. | |||
| Waters, R A and Lawrence, D J D. 1987. Geology of the South Wales Coalfield - Part III: the country around Cardiff. Memoir of the British Geological Survey, Sheet 263. (England and Wales). | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| E183 E199 E072 E127 E202 E142 E141 | |||