Chalk Group Lithostratigraphy: Northern England - Flamborough Chalk Formation

The Flamborough Chalk Formation (stratotype: Flamborough Head, between High Stacks [TA 258 704] and Sewerby [TA 202 687]), c. +215-?+300 m thick, is the youngest exposed chalk of the Chalk Group in northern England, although Wood & Smith (1978) reported an undescribed unit of younger flinty chalk in a borehole at Holderness, #### (Whitham, 1993). The formation is characterised by an absence of flint and a profusion of marl seams (at least 193 seams in 195 m of exposed chalk), the latter varying from thin plexi to thick seams up to 120 mm thick (Whitham, 1993). The lower part of the formation is very hard, massive-bedded chalk, but becoming softer and locally thinner-bedded at higher levels (Whitham, 1993).

The base of the formation is the top of the High Stacks Flint, but the top is undefined (Whitham, 1993), presumably because the youngest Flamborough Chalk occupies unexposed inland areas. The key marker-beds are as detailed below (NB: many more marls occur in the Flamborough Chalk than are shown below):

DIAGRAM HERE

Macrofossil Biozonation: M. coranguinum Zone (pars) (= Upper Hagenowia rostrara Zone of Whitham, 1993), U. socialis Zone, M. testudinarius Zone, U. anglicus Zone, I. lingua Zone

Correlation: see Correlation with other UK Chalk Group successions

References

WHITHAM, F.1993. The stratigraphy of the Upper Cretaceous Flamborough Chalk Formation north of the Humber, north-east England. Proceedings of the Yorkshire Geological Society, Vol. 49(3), 235-258.

WOOD C J & SMITH, E G.1978. Lithostratigraphical classification of the Chalk in North Yorkshire, Humberside and Lincolnshire. Proceedings of the Yorkshire Geological Society, Vol. 42(2), 263-287.