The BGS Lexicon of Named Rock Units — Result Details

Banks Group

Computer Code: BAKS Preferred Map Code: notEntered
Status Code: Full
Age range: Rhaetian Age (TR) — Sinemurian Age (JS)
Lithological Description: The group comprises interbedded sandstones, siltstones and mudstones of the Statfjord Formation, which are overlain by sandstones of the Nansen Formation.
Definition of Lower Boundary: The lower boundary is defined by the base of the Statfjord Formation. Where that formation is absent (e.g. East Shetland Basin), the arenaceous Nansen Formation rests on Triassic red, argillaceous strata (Cormorant Formation).
Definition of Upper Boundary: The upper boundary is defined by the top of the Nansen Fomation, which is placed at a downward change from mudstones of the Dunlin Group (Amundsen or Darwin formations) to sandstones.
Thickness: Up to 360 m in the East Shetland Basin and up to 155 m in the Beryl Embayment.
Geographical Limits: East Shetland Basin, Beryl Embayment and and parts of the Viking Graben. North Sea quadrants 3, 9, 210 and 211.
Parent Unit: Not Applicable (-)
Previous Name(s): Statfjord Group (-5176)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  North Sea well 211/24- 1 at 3112-3158.5 m depth below KB (Nansen Formation) (Richards et al., 1993). 
Type Section  Norwegian Sector North Sea well N33/12-2 at 2719-2951 m depth below KB (Statfjord Formation) (Richards et al., 1993). 
Reference(s):
Waters, C N, Gillespie, M R, Smith, K, Auton, C A, Floyd, J D, Leslie, A G, Millward, D, Mitchell, W I, McMillan, A A, Stone, P, Barron, A J M, Dean, M T, Hopson, P M, Krabbendam, M, Browne, M A E, Stephenson, D, Akhurst, M C, and Barnes, R P. 2007. Stratigraphical Chart of the United Kingdom: Northern Britain. (British Geological Survey.) 
Deegan, C E and Scull, B J. 1977. A standard lithostratigraphic nomenclature for the Central and Northern North Sea. Report of the Institute of Geological Sciences, 77/25; NPD Bulletin No.1. 
Richards, P C, Lott, G K, Johnson, H, Knox, R W O'B. and Riding, J B. 1993. 3. Jurassic of the Central and Northern 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