The Chalk rises up above the Gault and forms the high ground of Dunshill Moors and the Chiltern Hills.
The Inferior Cretaceous rocks include the Neocomian and Gault (Albian and Aptian) subdivisions, and form the flanks of the mountains in the Tell.
The Cambridgeshire coprolites are either amorphous or finger-shaped; the coprolites from the Greensand are of a black or dark-brown colour; while those from the Gault are greenish-white on the surface, brownish-black internally.
In the south the Albian subdivision of the Gault is alone represented.
Above the Lower Greensand comes the Gault Clay, which lies in the broad vale south-east of the former and north-west of the Chalk hills.
Of surface soil, glacial drift and impermeable gault clay and thence passed for a further depth of 70 ft.
The carbonaceous sandstone contains Gault fossils.
Wanting Danian Upper Chalk Senonian Middle Chalk Turonian Lower Chalk Cenomanian Upper Green-sand Gault Albian Aptian Lower Green-sand Valenginian Urgonian Wealden Neocomian In the continental classification the deposits from the Gault downwards are grouped as Lower Cretaceous; but in Great Britain there is a strong break below the Gault and 'none above; and the Gault is therefore classed as Upper Cretaceous.
The Cambridgeshire coprolites are believed to be derived from deposits of Gault age; they are obtained by washing from a stratum about a foot thick, resting on the Gault, at the base of the Chalk Marl, and probably homotaxeous with the Chloritic Marl.
Within the Upper Greensand an equally narrow ring of Gault is exposed, its stiff clay forming level plains of grazing pasture, without villages, and with few farmhouses even; and from beneath it the successivOeds of the Lower Greensand rise towards the centre, forming a wider belt, and reaching a considerable height before breaking off in a fine escarpment, the crest of which is in several points higher than the outer ring of Chalk.