Part 3

We will suppose that we have arrived at Hunstanton, and are walking towards the shore in front of the Le Strange Arms. A very few minutes will convey us to the wonderful cliff. I say wonderful, not from its height or length; for at its greatest height, under the lighthouse, it is not more than sixty feet; and it extends little more than a mile in length; but wonderful from its curious colour and general effect.

The woodcut, copied from a water-colour drawing, made last autumn by a friend, will afford an idea of its appearance; but in it the absence of colour, of course, takes away from the beauty of the scene.

The cliff itself may be divided into five portions: first, White Chalk, forty feet thick; secondly, bright Red Chalk, four feet; thirdly, a yellow sandy mass, ten feet; fourthly, a dark brown pebbly stratum, forty feet; and, lastly, twenty feet of a bed almost black.

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.

The length of the Red Chalk, from end to end, at the Hunstanton Cliff is about 1,000 yards, and its greatest elevation at the point where it attains the top and quits the cliff is thirty-seven feet; hence its rise is very gradual, since its first appearance is nearly on a level with the beach.

There are two other things worth observing at Hunstanton. One is the lighthouse, which is upon the dioptric principle, the light being transmitted out to sea by means of glass prisms instead of the ordinary metal reflectors; and the other is a vestige of a raised sea-beach on the cliffs composed of rounded fragments of White and Red Chalk immediately reposing on the greensand. It is situated at the southward of the point where the Red Chalk crops out.

We will now, if you please, quit Hunstanton, and proceed towards Lynn, keeping in the neighbourhood of the coach-road.

If we could dig up the ground when we were within eight or nine miles of Lynn, we should still see our old companion at our feet, for the Red Chalk has been recognised at the villages of Ingoldsthorpe and Dersingham.

We shall soon meet it no more. At Leziate, a little to the north-east of Lynn, it becomes extinct. Mr. C. B. Rose, who always thought the Red Chalk would prove to be the equivalent of the gault, and who argued from the evidence of fossils and from the direction of the outcrops that the true gault and the Red Chalk must ultimately meet,--Mr. Rose, I say, has informed me that he has observed the Red Chalk and the gault incorporated together at Leziate. Henceforward to the south the Red Chalk is no more seen.

Thus, then, we have come to the termination of our journey. We have noted the beginning and the ending of the Red Chalk, we have also taken some account of its neighbours. We have noticed, too, that in Yorkshire it for the most part reposes on the Speeton clay, though in certain localities it is next the lias and Kimmeridge clay, and that in Lincolnshire and Norfolk it rests on a dark brown pebbly mass supposed to belong to the lower greensand formation of the south of England.

The Red Chalk has also been discovered in a very unexpected place, although not in sitû. I allude to the drift of Muswell Hill. In that collection of different materials, comprising examples from every formation from the London clay to the mountain limestone in a stratum of eighteen feet, the Red Chalk has been seen in a bouldered condition.

By the kindness of Mr. Wetherell of Highgate, I am enabled to exhibit specimens from the drift of Muswell Hill. Any person who compares them with others from Hunstanton, would declare they came from the same bed, so alike are they in appearance.

There was a time no doubt when this Red Chalk had a more extended range: its presence in the drift of Muswell Hill, as well as in the drift of other places, implies as much. Perhaps it may still exist elsewhere, deep down in the earth.

In a well sunk at Stowmarket a red substance was found under the White Chalk, at a depth of 900 feet; and in another well sunk at Kentish Town, the workmen met, at a depth of 1,113 feet below the surface, beneath the gault, a bed of red matter 188 feet thick--some of this red matter appeared to contain belemnites.

Geologists are divided in opinion with respect to this deep-sunk red bed, which certainly is not always continuous (for instance, it was not found at a boring at Harwich), and some incline to the opinion that it belongs to the New Red, others that it is the equivalent of what is styled the Red Chalk. But it is difficult to give a solution at present. It is certain that in the gault formation, or near it, beds of a red colour are occasionally found. Near Dorking the lower greensand is capped by a local bed of bright red clay, eight feet thick. And examples of red clays from the gault of Ringmer in Sussex and Charing in Kent can be seen in the Museum of the Geological Society of London. Whether they have any relation with the Red Chalk proper of England depends upon the position which is given to that formation.

Geologists generally consider the Red Chalk as really equal to the Gault. Many of the fossils certainly are gault species; others no doubt belong to the Lower Chalk; and, therefore, probably it is better to regard it as an intermediate formation between the Lower Chalk and the Lower Greensand, which comes into being when the Gault and Upper Greensand have almost thinned out.

One of the members of our Committee, Mr. Rickard, has been good enough to make me an analysis of the Red Chalk of Speeton and Hunstanton. The Speeton is as follows:--

Carbonate of lime, with a little alumina 81.2 Peroxide of iron 4.3 Silica 14.5 ----- 100. -----

From Hunstanton--

Carbonate of lime, with a little alumina 82.3 Peroxide of iron 6.4 Silica 11.3 ----- 100. -----