The BGS Lexicon of Named Rock Units — Result Details

Strangways Formation

Computer Code: STRW Preferred Map Code: notEntered
Status Code: Full
Age range: Bajocian Age (JB) — Bathonian Age (JN)
Lithological Description: The formation comprises predominantly sandstones with interbedded siltstones, mudstones and occasional limestones. Sandstones are pale grey to white, poorly to well cemented, very fine- to medium-grained, occasionally glauconitic and carbonaceous. Interbedded mudstones are pale green-grey, dark grey or variegated. Limestones are grey, buff or cream, micritic, oolitic or bioclastic.
Definition of Lower Boundary: The lower boundary is characterised by a change from sandstones to dominantly mudstones (Wroot Formation) and a corresponding down-section increase in gamma values and decrease in velocity.
Definition of Upper Boundary: The top of the formation is marked by a sharp downward change from variegated mudstones (Hudleston Formation) to sandstones or siltstones with interbedded mudstones. The lithological change coincides with a down-section decrease in gamma-ray values and, usually, an increase in velocity.
Thickness: Up to 150 m.
Geographical Limits: Southern North Sea Basin (quadrants 41-43, 46-48, 51-52).
Parent Unit: West Sole Group (WSTS)
Previous Name(s): West Sole Group (WSTS)
Alternative Name(s): Ellerick Formation
Werkendam Shale Formation
Lincolnshire Limestone Formation
Cloughton Formation
Glentham Formation [Obsolete: use BWL, BWC, RLD]
Scarborough Formation
Pentland Formation
Stratotypes:
Type Section  North Sea well 47/03b- 4 between 979 and 1117 m (Lott and Knox, 1994). 
Reference Section  North Sea well 42/24- 1 between 328 and 369 m (Lott and Knox, 1994). 
Reference Section  North Sea well 47/10- 1 between 1538.5 and 1671 m (Lott and Knox, 1994). 
Reference Section  North Sea well 48/03- 3 between 995 and 1137 m (Lott and Knox, 1994). 
Reference(s):
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. 
Lott, G K and Knox, R W O'B. 1994. 7. Post-Triassic of the Southern North Sea. In: Knox, R W O'B and Cordey, W G (eds.) Lithostratigraphic nomenclature of the UK North Sea. British Geological Survey, Nottingham. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable