These divisions do not run one into the other, as is the case in most geological strata, but keep quite distinct. Thus the Red Chalk is as clearly separated from the White, as though the one had been covered by a broad band of paint. The same observation will hold good with respect to the others.
It will readily be understood that when the sun shines upon the cliff, and lights up the bright white, the bright red, the pale yellow, and the dark brown and black, and casts a shadow over the mass of gaily tinted materials at the base, a picture is produced not easy to be surpassed in beauty, and certainly not to be fully appreciated unless it be actually seen.
The bed of White Chalk above the Red is, at Hunstanton, very fossiliferous; though rendered somewhat useless, like that of Yorkshire, to the geologist, from its extreme hardness. Amongst other shells, may be mentioned several kinds of serpulæ, belemnites, and ammonites. These last are occasionally very large: when I was at Hunstanton, in the autumn, I found an example two feet in diameter; with great difficulty I extricated it from its matrix, breaking it in half during the operation; and, finally, had the mortification of discovering that its weight was so great I could not carry it away.
The Red Chalk beneath, which is nearly four feet in thickness, is very full of fossils: belemnites, serpulæ, terebratulæ, corals, and many others, not to mention bones. The number of specimens on the table will testify to its richness in organic remains.
Sometimes it is soft and crumbling; but, generally speaking, it is very hard, gritty, of a bright red shade, and full of small dark-coloured siliceous pebbles; in this respect differing considerably from the Red Chalk of Speeton—in which I have not seen pebbles. Professor Tennant, who has examined the Hunstanton pebbles, informs me that they consist of chalcedony, quartz, flint, slate, and brown spar or carbonate of iron.
It also contains a great quantity of fragments of inocerami, and a curious ramifying sponge-like structure (there is one on the table), which also occurs in the White Chalk above.
Something very similar to the ramifying sponge is seen on the surface of blocks on the sea-shore at the back of the Isle of Wight in the greensand formation, and one very like it on the calcareous grit of the Yorkshire shore. You will observe these last to the north of Filey, but nothing of the same appearance exists in the White Chalk at Speeton.
Underneath the Red Chalk of Hunstanton occurs a yellow and brown pebbly sandstone, which was formerly supposed to contain no organic remains. Mr. C. B. Rose of Yarmouth, however, has obtained many.
This bed is termed in those parts "carstone," and much employed as a building-material. The cottages in that neighbourhood and on the road from Lynn seem at a distance as though they had been constructed of masses of gingerbread, so great is the similarity in colour and appearance.