The BGS Lexicon of Named Rock Units — Result Details
Claughton Member
| Computer Code: | CLAU | Preferred Map Code: | Clau |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Arnsbergian Substage (CG) — Arnsbergian Substage (CG) | ||
| Lithological Description: | Typical delta slope facies. Predominantly sandy grey micaceous shaly siltstones with irregular interbeds of fine- to medium-grained micaceous plant-rich sandstone, very variable thickness and bedding commonly syndepositionally slumped. NOTE: Moseley named the delta slope sequence between the entirely marine Caton Shales and the delta top Crossdale Grit (now Silver Hills Sandstone), the Claughton Flags. Thus it is proposed to rename the unit Claughton Member since it is predominantly siltstone and is analogous to the Roeburndale Member below the Caton Shale Member. | ||
| Definition of Lower Boundary: | Sharp junction between fossiliferous fissile clayey blue-grey mudstones with limestone nodules and thin sideritic lenses of Caton Shale Member below and siltstones with sandstones of the Claughton Member. | ||
| Definition of Upper Boundary: | Not seen; believed to be sharp, at erosional base of delta-top coarse-grained sandstone of the Silver Hills Sandstone. | ||
| Thickness: | c.200-300m in the Claughton area, but upper part not represented. | ||
| Geographical Limits: | Lancaster Fells. Moseley (1956) used Keasden Flags for the same unit in the Keasden area. Used in the Settle Memoir but not defined. Keasden Flags is a synonym for Claughton Member. | ||
| Parent Unit: | Silsden Formation (SILS) | ||
| Previous Name(s): | Claughton Formation [Obsolete Name and Code: Use SILS, CLAU]
(-3304)
Claughton Flags [Obsolete Name and Code: Use CLAU] (-4545) |
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| Alternative Name(s): | Nottage Crag Grit Keasden Flags. Claughton Moor Shales [Obsolete: use CLMS] Moorcock Flags [Obsolete: use MOCS] Claughton Flag Series [Obsolete: use BACB] |
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| Stratotypes: | |||
| Type Section | Greenhales Beck: basal c.72m completely exposed in faulted section. Incised stream gulley repeatedly affected by small NW-SE faults, commencing 650m upstream from road bridge. | ||
| Reference Section | Westend Beck. Basal c.200m exposed in incised beck and old brickpits. | ||
| Reference Section | Claughton Beck and brick pit. | ||
| Type Area | Claughton. No complete section. | ||
| Reference(s): | |||
| Waters, C N, Waters, R A, Barclay, W J, and Davies, J R. 2009. Lithostratigraphical framework for Carboniferous successions of Southern Great Britain (Onshore). British Geological Survey Research Report, RR/09/01. 184pp. | |||
| Brandon, A, Aitkenhead, N, Crofts, R G, Ellison, R A, Evans, D J, and Riley, N J. 1998. Geology of the country around Lancaster. Memoir of the British Geological Survey, Sheet 59 (England and Wales). | |||
| Moseley, F, 1954. The Namurian of the Lancaster Fells. Quarterly Journal of the Geological Society of London, Vol.109, 423-454. | |||
| Moseley, F, 1956. The geology of the Keasden area, west of Settle, Yorkshire. Proceedings of the Yorkshire Geological Society, Vol.30, 331-352. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| E059 | |||