The BGS Lexicon of Named Rock Units — Result Details
Ferriby Chalk Formation
| Computer Code: | FYCK | Preferred Map Code: | FyCk |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Cenomanian Age (KE) — Cenomanian Age (KE) | ||
| Lithological Description: | Grey, soft, marly, flint-free chalk, typically weathering buff in exposures; locally includes pinkish bands; some harder, gritty, shell-debris-rich beds, and thin discrete marl seams. | ||
| Definition of Lower Boundary: | The lower boundary is placed at an erosion surface, locally developed on a hardground, overlain by nodular chalk (lowest Cenomanian) of the Paradoxica (or Sponge) Bed or, in the Cleveland Basin, the flaser-bedded white chalks with red or purple marls of the Crowe's Shoot Member (Gaunt et al., 1992; Mitchell, 1995). | ||
| Definition of Upper Boundary: | The upper boundary is an uneven erosion surface, that may be stained with iron minerals and glauconite, at the top of a succession of marly chalk (Ferriby Formation) and a little way above the so called Upper Pink Band (of bed status). This surface is succeeded by a thin unit of marls and marly chalks (the Plenus Marls Member, Welton Formation), which generally forms a topographical slack at outcrop. This facilitates the mapping of the top of Ferriby Formation, which is also readily recognised from geophysical log signature in boreholes. | ||
| Thickness: | The formation is typically about 20 to 25 m thick throughout the southern part of the region. It thins to 10 to 15 m over the Market Weighton High (Jeans, 1973) and its extension to Hornsea. It thickens immediately at the margin of the Cleveland Basin to the north, being 33 to 35 m thick on the coast at Speeton (Wright, 1963; Jeans, 1980), and possibly 50 m or more in boreholes inland near Fordon. | ||
| Geographical Limits: | Throughout the Yorkshire and Lincolnshire Wolds, and superficial deposit-covered area to southeast, from Speeton Cliffs south to the Skegness area on the Lincolnshire coast. | ||
| Parent Unit: | Grey Chalk Subgroup (GYCK) | ||
| Previous Name(s): | Ferriby Formation [Obsolete Name and Code: Use FYCK]
(-4663)
Lower Chalk [Obsolete Name and Code: Use FYCK, GYCK] (-4056) Chalk Without Flints (-903) |
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| Alternative Name(s): | Grey Chalk Subgroup |
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| Stratotypes: | |||
| Reference Section | Speeton Cliffs. The full succession is visible at various exposures within the landslid cliffs. See Wright (1963); Mitchell (1992). | ||
| Type Area | Humberside area of North Lincolnshire and East Riding of Yorkshire. See Gaunt et al. (1992). | ||
| Type Section | South Ferriby Quarry, Lincolnshire. The full succession was visible and taken as the standard for the Humberside region at this quarry. See Gaunt et al. (1992). | ||
| Reference(s): | |||
| Mitchell, S F. 1995. Lithostratigraphy and biostratigraphy of the Hunstanton Formation (Red Chalk, Cretaceous) succession at Speeton, North Yorkshire, England. Proceedings of the Yorkshire Geological Society, Vol.50, 285-303. | |||
| Wright, C W. 1963. Itinery IX. Reighton Gap to Speeton Cliffs. 30-33 in Hester, S W (editor), Geology of the Yorkshire Coast. Geologists' Association Guide, No.34 (first edition). | |||
| Rawson, P F. 1992. Cretaceous, 355-388 in Duff, P McL D and Smith, A J (editors), Geology of England and Wales. (London: Geological Society.) | |||
| Sumbler, M G. 1996. The stratigraphy of the Chalk Group in Yorkshire, Humberside and Lincolnshire. British Geological Survey Technical Report WA/96/26C. | |||
| Hopson, P M. 2005. A stratigraphical framework for the Upper Cretaceous Chalk of England and Scotland, with statements on the Chalk of Northern Ireland and the UK Offshore Sector. British Geological Survey Research Report RR/05/01 102pp. ISBN 0 852725175 | |||
| Waters, C N, Smith, K, Hopson, P M, Wilson, D, Bridge, D M, Carney, J N, Cooper, A H, Crofts, R G, Ellison, R A, Mathers, S J, Moorlock, B S P, Scrivener, R C, McMillan, A A, Ambrose, K, Barclay, W J, and Barron, A J M. 2007. Stratigraphical Chart of the United Kingdom: Southern Britain. British Geological Survey, 1 poster. | |||
| Whitham, F. 1991. The stratigraphy of the Upper Cretaceous Ferriby, Welton and Burnham formations north of the Humber, north-east England. Proceedings of the Yorkshire Geological Society, Vol.48, 227-254. | |||
| Wood, C J and Smith, E G. 1978. Lithostratigraphical classification of the Chalk in North Yorkshire, Humberside and Lincolnshire. Proceedings of the Yorkshire Geological Society, Vol. 42, 263-287. | |||
| Gaunt, G D, Fletcher, T P, and Wood, C J. 1992. Geology of the country around Kingston upon Hull and Brigg. Memoir of the British Geological Survey, sheets 80 and 89 (England and Wales). 172pp. | |||
| Sumbler, M G. 1999. The stratigraphy of the Chalk Group in Yorkshire and Lincolnshire. British Geological Survey Technical Report WA/99/02. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| E103 E104 E115 E116 E054 E055 E064 E065 E072 E073 E080 E081 E089 E090 E091 | |||