Chronostratigraphy of the Chalk Group - Santonian Stage
The Santonian stage was first defined by Coquand (1857), and presumably named after the village of Saintes in SW France (Lamolda & Hancock, 1996).
Definition of base of stage
The lowest occurrence of the inoceramid bivalve Cladoceramus undulatoplicatus (Lamolda & Hancock, 1996).
Constituent Chalk Group lithostratigraphical units in the UK
Integrated southern England Chalk Group lithostratigraphy: Seaford Chalk Formation (pars) and Newhaven Chalk Formation (pars)
Northern England: Flamborough Chalk Formation (pars)
East Anglia: Upper Chalk (pars)
N. Ireland: Cloghfin Sponge Beds Member, Galboly Chalk Member, Cloghastucan Chalk Member
North Sea: Mackerel Formation (pars)
| SANTONIAN | M.testudunarius | |
| U.socialis | ||
| M.coranguinum (pars) | Upper H.rostrata Zone (Northern England only) |
Lithostratigraphical marker-beds for the base of the stage
Southern England: Michael Dean Flint
Northern England: ? between Middleton Top Marl and the High Stacks Flint (Burnett & Whitham, 1999)
East Anglia: ? an un-named flint at 366.5 m depth in the BGS Trunch Borehole [TG 2933 3455] in north Norfolk (Wood et al., 1994); boundary poorly defined in remainder of East Anglia
N. Ireland: basal part of stage not represented by Chalk Group strata
References
BURNETT, J A & WHITHAM, F. Correlation between the nannofossil and macrofossil biostratigraphies and the lithostratigraphy of the Upper Cretaceous of NE England. Proceedings of the Yorkshire Geological Society, 52, 371-381.
COQUAND, H. 1857. Position des Ostrea columba et biauriculata dans le groupe de la craie inférieure. Bulletin de la Société géologique de France (2), 14, 745-766.
LAMOLDA, M A & HANCOCK, J M. 1996. The Santonian Stage and substages. Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, 66-Supp, 95-102.
WOOD, C J, MORTER, A A & GALLOIS, R W. Appendix 1: Upper Cretaceous stratigraphy of the Trunch Borehole. In ARTHURTON, R S, BOOTH, S J, MORIGI, A N, ABBOTT, M A W & WOOD, C J. 1994. Geology of the country around Great Yarmouth. Memoir of the British Geological Survey.