Chalk Group Lithostratigraphy: Marlborough Downs/Berkshire Downs/Chilterns - Clandon Hardground
The Clandon Hardground (stratotype West Clandon [TQ 038508], Surrey) was fist described by Robinson (1986) in the North Downs, where this indurated chalk bed represents a condensed lateral equivalent of the Barrois Sponge Bed at the top of the Broadstairs Member. The hardground is also present in the Chilterns at Taplow, Berks, where it is overlain by a succession of locally developed phosphatic chalks (Wood, 1996).
Macrofossil Biozonation: topmost M. coranguinum Zone
Correlation: see Correlation with other parts of the UK
ROBINSON, N D.1986. Lithostratigraphy of the Chalk Group of the North Downs, southeast England. Proceedings of the Geologists' Association, Vol. 97, 141-170.
WOOD, C. J. 1996. Upper Cretaceous: the Chalk Group. In SUMBLER, M. G., British Regional Geology: London and the Thames Valley. Fourth Edition. (London: HMSO for the British Geological Survey).
See: Clandon Hardground (marker bed), Barrois Sponge Bed, Broadstairs Member (North Downs), phosphatic chalk