The BGS Lexicon of Named Rock Units — Result Details

Black Band Member

Computer Code: BKBD Preferred Map Code: notEntered
Status Code: Full
Age range: Cenomanian Age (KE) — Turonian Age (KT)
Lithological Description: Interbedded black or very dark carbonaceous calcareous mudstone (the Black Band) and variegated calcareous mudstone (marl) succession terminating in the "sticky green clay" of Wood and Mortimore, 1995.
Definition of Lower Boundary: The lower boundary is conformable at the basal surface of the Main Black Band as defined in Wood and Mortimore (1995) and Wood et al. (1997) with the underlying Plenus Marls Member (q.v.).
Definition of Upper Boundary: The upper boundary is conformable at the junction between a sticky green clay (Bed 6 i.e. the top of the "Variegated beds", in Figure 4, Wood and Mortimore, 1995) and an extremely condensed succession of shell-detrital limestones with some thin very dark "marl" seams.
Thickness: Generally about 0.5 to 0.6m but up to 1.4m in the Cleveland Basin.
Geographical Limits: A well-known marker throughout the Northern Province and in the offshore areas.
Parent Unit: Welton Chalk Formation (WCK)
Previous Name(s): "Expanded Standard Black Band Succession" (-3220)
Basal Beds (-3221)
Plenus Marls Member (PLMA)
Variegated Beds (-60)
Flixton Member (-700)
Alternative Name(s): Beds C To H
Stratotypes:
Type Section  South Ferriby Quarry, Lincolnshire [SE 9915 2045]. See Gaunt et al. (1992). 
Reference Section  Melton Ross Quarry, Lincolnshire [TA 082 112]. see Wood and Mortimore,(1995). 
Reference Section  Melton Bottom upper quarry [SE 970 280]. Also the stratotype for the whole Welton Chalk Formation. 
Reference(s):
Dodsworth, P. 1996. Stratigraphy, microfossils and depositional environments of the lowermost part of the Welton Chalk Formation (late Cenomanian to early Turonian, Cretaceous) in eastern England. Proceedings of the Yorkshire Geological Society, Vol.51, 45-64. 
Wood, C J, Batten, D J, Mortimore, R N and Wray, D S. 1997. The stratigraphy and correlation of the Cenomanian-Turonian boundary interval succession in Lincolnshire, northern England. Freiberger Forschungsheft, Reihe C, Vol. 468, 333-346. 
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. 
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 
Sumbler, M G. 1999. The stratigraphy of the Chalk Group in Yorkshire and Lincolnshire. British Geological Survey Technical Report WA/99/02. 
Wood, C J and Mortimore, R N. 1995. An anomalous Black Band succession (Cenomanian-Turonian boundary interval) at Melton Ross, Lincolnshire, eastern England and its international significance. Berliner Geowissenschaftliche Abhandlungen, Reihe E, Vol.16, 277-287. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable