The BGS Lexicon of Named Rock Units — Result Details

Cast Bed

Computer Code: CASB Preferred Map Code: notEntered
Status Code: Full
Age range: Cenomanian Age (KE) — Cenomanian Age (KE)
Lithological Description: Pale yellow sandy silty chalk with fossils including a notable brachiopod fauna.
Definition of Lower Boundary: The lower boundary is an erosive contact with highest beds in the West Melbury Marly Chalk Formation or conformable on the same formation (top of the Tenuis Limestone) where the full succession is present.
Definition of Upper Boundary: The upper boundary is conformable with the overlying limestone of bed C2 of Gale (1995).
Thickness: Thin; generally in the range 0.1 to 0.5 m.
Geographical Limits: Known within the Southern Chalk Province of England.
Parent Unit: Zig Zag Chalk Formation (ZZCH)
Previous Name(s): none recorded or not applicable
Alternative Name(s): Totternhoe Stone Member
Stratotypes:
Reference Section  The bed is the marker that divides the West Melbury Marly Chalk Formation and the Zig Zag Chalk Formation in the cliffs. The bed is about 1 m thick in this section. See Mortimore et al. (2001, p. 266, Figure 3.119). 
Reference(s):
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 
Mortimore, R N, Wood, C J and Gallois, R W, 2001. British Upper Cretaceous Stratigraphy. Geological Conservation Review Series. No. 23. (Peterborough: Joint Nature Conservation Committee.) 
Gale, A S. 1995. Cyclostratigraphy and correlation of the Cenomanian of western Europe. 177-197 in House, M R and Gale, A S (editors), Orbital forcing timescales and cyclostratigraphy. Geological Society of London Special Publication, No.85. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable