The sketch given in [page 27], represents the appearance of part of the coast to the east of Kemptown. The base of the cliff to the height of a few feet, is seen to consist of the white chalk with its usual layers of flint nodules, forming a low wall or terrace, which slopes seaward, and extends far into the British channel—probably to the opposite coast of France: at low-water a considerable expanse of modern shingle and sand is spread over, and in a great measure conceals, the chalk, at a few yards distance from the cliff. Upon the terrace of chalk, at the height of from ten to fifteen feet above the modern beach, there is a bed of pebbles and sand, containing also a considerable number of boulders of granite, porphyry, and other crystalline rocks foreign to the south-east of England: in fact, a sea-beach, which must have been formed at some remote period, in the same manner as the modern shingle. Upon this ancient beach are strata of loam, and chalk-rubble, with flints partially water-worn, and boulders of sandstone, breccia, granite, &c., constituting the upper sixty or eighty feet of the cliff. In these beds, and also in the ancient shingle, many teeth and bones of mammoths (extinct species of elephant), horse, deer, oxen, and other ruminants, and bones of whales, have been discovered.[AF]
[AF] See 'Medals of Creation,' p. 914.
THE SUSSEX COAST.
A few hundred yards beyond Kemptown the inroads of the sea have destroyed all vestiges of the strata above described, and the cliffs consist of a perpendicular wall of chalk; if we extend our walk to Rottingdean, we shall perceive here and there isolated patches of the ancient shingle, and of the calcareous strata containing elephants' bones.
The appearances described demonstrate the following changes in this part of the Sussex coast. Firstly, the chalk terrace ([Lign. 9, c; p. 27]) on which the ancient shingle (b) rests, was on a level with the sea for a long period; for this beach must have been accumulated, like the modern, by the action of the waves on the then existing chalk cliffs. But there must also have been some cause not now in operation, by which pebbles, and boulders of granite and other rocks foreign to this coast, with bones of extinct mammalia, &c., were thrown up on the strand, and imbedded in the beach then in progress of formation. These materials were probably brought from some distant part of the then continental shores by floating ice: an agency by which delicate bones and shells may be transported and deposited without injury amidst pebbles and boulders.
Secondly. The whole line of coast with the ancient shingle must have subsided to such a depth as to admit of the deposition of the calcareous materials forming the "Elephant bed;" and from the absence of beach and shingle in these strata, it may be inferred that this deposition took place in tranquil water: possibly at that period this part of the Sussex coast formed a sheltered bay.
Lastly. The land was elevated to its present level, and the formation of the modern sea-beach and cliffs commenced.[AG]
[AG] See 'Medals of Creation,' "On the Geological structure of Brighton Cliffs," p. 913.