The BGS Lexicon of Named Rock Units — Result Details
Westward Ho! Member
| Computer Code: | WDHO | Preferred Map Code: | notEntered |
|---|---|---|---|
| Status Code: | Pending Upgrade | ||
| Age range: | Langsettian Substage (CA) — Langsettian Substage (CA) | ||
| Lithological Description: | Thin-bedded mudstones, siltstones and sandstones, some of which are turbiditic and others cross-laminated and wave rippled. The succession is cut by several channels filled from 3 to 25m deep by slumped and disturbed strata, or more rarely cross-bedded or cross-laminated sandstones | ||
| Definition of Lower Boundary: | The lower boundary is taken at the incoming of channels overlain by syndepositionally disturbed units and thick, locally cross- bedded sandstones of the Westward Ho! Member above the regularly interbedded mudstones and turbidite sandstones of the underlying Crackington Formation. This boundary is not exposed on the coast at the type locality and has never been mapped, as the Westward Ho! Member was previously included in the Crackington Formation. Further investigation of this boundary is needed. | ||
| Definition of Upper Boundary: | The upper boundary is taken at the incoming of coarsening-upwards cycles (mudstone, interbedded mudstone and sandstone, cross-bedded sandstone) of the main part of the Bideford Formation above the top of the Mermaid's Pool Sandstone, a thick, mappable, cross-bedded sandstone at the top of Westward Ho! Member. | ||
| Thickness: | 400m+ | ||
| Geographical Limits: | Westward Ho! area (SS 41 29), Bideford, north Devon. As the Member is unmapped it is not known how far east it extends, but it is possible that it occupies the lower part of the Bideford Formation as far as the eastern limit of the latter to 6km west of South Molton (SS 71 26), mid Devon. | ||
| Parent Unit: | Bideford Formation (BFF) | ||
| Previous Name(s): | Crackington Formation
(CKF)
Northam Beds (-691) Westward Ho Formation [Obsolete Name And Code: See WDHO] (WHF) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Partial Type Section | Coastal cliffs and foreshore north of Mermaid's Pool at Westward Ho!, north Devon. Upper 400m exposed. Upper contact of Mermaid's Pool Sandstone with rest of overlying Bideford Formation exposed, but base of Member not seen. Walker, 1970; Xu Li, 1990. | ||
| Reference(s): | |||
| Edmonds, E A, Williams, B J and Taylor, R T. 1979. Geology of Bideford and Lundy Island. Memoir of the Geological Survey of Great Britain, Sheets 292 with 275, 276, 291, and part of 308 (England and Wales). | |||
| Prentice, J E. 1960. The stratigraphy of the Upper Carboniferous rocks of the Bideford region, north Devon. Quarterly Journal of the Geographical Society of London, Vol.116, 397-408. | |||
| Xu Li. 1990. Changes in the Deltaic Sedimentation in the Upper Carboniferous Westward Ho! Formation and Bideford Group of southwest England. Proceedings of the Ussher Society, Vol.7, 232-236. | |||
| Waters, C N, Barclay, W J, Davies, J R and Waters, R A. In press. Stratigraphical framework for Carboniferous successions of Southern Great Britain (Onshore). British Geological Survey Research Report, RR/05/06. | |||
| Walker, R G. 1970. Deposition of turbidites and agitated-water siltstones: a study of the Upper Carboniferous Westward Ho! Formation, north Devon. Proceedings of the Geologists' Association, Vol.18, 43-67. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| none recorded or not applicable | |||