Chronostratigraphy of the Chalk Group - Maastrichtian Stage

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This stage was first defined by Dumont (1850), based on the area around Maastricht in the Netherlands (Birkelund et al., 1984).

Definition of base of stage[edit]

The first appearance of the belemnite genus Belemnella (Birkelund et al., 1984), but this is difficult to precisely identify in UK successions, where a better criterion is the acme of the foraminiferan Reussella szajnochae (Bailey et al., 1984). Burnett et al. (1992) pointed out that the alleged synchroneity of micro-fossil and macro-fossil events across the Campanian / Maastrichtian boundary is false. Micro-fossil indices for the basal Maastrichtian occur below macrofossil indices for the same horizon.

Constituent Chalk Group lithostratigraphical units in the UK[edit]

East Anglia: Sidestrand Chalk Member, Trimingham Sponge Beds Member, Little Marl Point Member, Beacon Hill Grey Chalk Member

N. Ireland: Tanderagee Chalk Member, Port Calliagh Chalk Member, Ballycastle Chalk Member

North Sea: Mackerel Formation (pars), Tor Formation

Constituent macrofossil biozones in the UK (onshore)
younger Maastrichtian macrofossil biozones not preserved onshore in the UK
MAASTRICHTIAN B.occidentalis (pars)
B.lanceolata s.l.

Lithostratigraphical marker-beds for the base of the stage[edit]

East Anglia: not precisely defined, owing to lack of continuous exposure; the highest exposed Campanian is marked by the Overstrand Pyramidata Hardground in north Norfolk.

N. Ireland: the Long Gilbert Flint


BAILEY, H W, GALE, A S, MORTIMORE, R N, SWIECICKI, A & WOOD, C J. 1984. Biostratigraphical criteria for the recognition of the Coniacian - Maastrichtian stage boundaries in the Chalk of north-west Europe, with particular reference to southern England. Bulletin of the Geological Society of Denmark, Vol. 33, 31 - 39.

BURNETT, J A, HANCOCK, J M, KENNEDY, W J & LORD, A R. Macrofossil, planktonic foraminiferal and nannofossil zonation at the Campanian / Maastrichtian boundary. Newsletters on stratigraphy, 27, 157-172

BIRKELUND, T, HANCOCK, J M, HART, M B, RAWSON, P F, REMANE, J, ROBASZYNSKI, F, SCHMID, F, SURLYK, F. 1984. Cretaceous stage boundaries - Proposals. Bulletin of the Geological Society of Denmark, 33, 3-20.

Dumont, A. 1850. Rapport sur la carte geologique de royaume. Acad. Roy. Sci. Lettres, Beaux-Arts, Belgique Bull, 16, 351-373.