Southern Region Chalk Group Lithostratigraphy: Traditional Classification - Basement Bed

The Basement Bed is a condensed phosphatic nodule bed at the base of the Chalk Group in Dorset and southeast Devon. Kennedy (1970) showed that its rich fauna represents a condensation of the lower part of the Lower Chalk, and that the amount of condensation represented by this horizon varies between localities and can be used to infer the presence of a tectonic 'high', named the 'Mid Dorset Swell'.

Macrofossil Biozonation: Variable, but M. mantelli Zone to C. guerangeri Zone where highly condensed.

Correlation: see Correlation with other Southern Region Chalk Group classifications

see Correlation with other UK Chalk Group successions

References

KENNEDY, W J. 1970. A correlation of the uppermost Albian and the Cenomanian of South-West England. Proceedings of the Geologists' Association, Vol. 81(4), 613-677.