Thomas Codrington

“ The regularity of the surface of the plains, where they are not cut up by streams, is very remarkable, more so on the ground than would perhaps appear from some of the sections, in which the vertical heights being necessarily greatly exaggerated, every irregularity is magnified to about thirteen times its natural scale.
To the westward of the Avon, the triangular tableland between Christchurch, Wimborne, and Poole is cut off on the north by the Stour valley. ”

“ The main mass of gravel consists of rounded chalk-flints, imbedded in sand and distinctly stratified in layers of pebbles of assorted sizes, dipping slightly northward. The flints, though well rounded, have not the finish of the pebbles in tertiary pebble-beds, and the structure shows it to be a beach-deposit. Seams of pure sand overlie bands of pebbles as large as oranges, and layers of pebbles stained a dark red are succeeded sharply by bands of white pebbles. ”

“ Northward of the escarpment the general surface of the country is 80 or 100 feet lower, much intersected by the tributary streams of the Beaulieu river, and generally covered by a wash of gravelly loam; but detached gravel-topped hills rise in the lower ground to levels corresponding to the plains, and are evidences of the former extension of the tableland beyond its present northern edge. ”

“ The raised shingle of the Foreland, the marine gravel of the south of Sussex, and the beach-deposits with sea shells at Avisford and Waterbeach are evidences that at a time geologically recent the land stood 80 or 100 feet lower. Flint implements, however, are found imbedded in gravel 120 feet above the sea on the Bournemouth cliffs, and 150 feet above the sea on Southampton Common; and an hypothesis which assumes that man existed when gravels, now 120 and 150 feet above the sea, were forming at or below the sea-level may be on that account alone considered as untenable. ”

“ In a section in a brick-yard to the east of Lymington the red gravel seems to have been cut away before the white was deposited on its flank. In the chines or bunnies to the west of Bournemouth there are sections at right angles to the coast showing the reel gravel with brick-earth over it, ending against a slope of Bagshot sand on the land side and thinning out towards the sea, so that the white gravel which overlies both overlaps the brick-earth, and rests directly on the red gravel, reduced to less than half its thickness in the sea face of the cliff. ”

“ The peat-bed does not much exceed a foot in thickness; it is described by Mr. Godwin-Austen, who examined it with Professor E. Forbes, as having the usual characteristics of accumulations of vegetable matter in damp situations, and containing the remains of large trees, hazel-nuts, and beetles [25] . The top of the cliff where the peat-beds are is less than 25 feet above the mean sea-level, and the gravel is much more clayey than the pebble-gravel proper, and confused in the bedding. ”

“ Denudation of the surface by subaerial action, and of the coast by the sea, must have gone on pari passu with upheaval ever since the high plains were first raised above the sea-level. As the land gradually rose, the effect would have been to contract the inlet and bring it into the condition of an estuary branching into the Solent and Southampton Water. Of these, the latter remains an estuary, while the Solent has become an arm of the sea by the severance of the Isle of Wight from the mainland. ”

“ The main mass appears to fill up an old channel cut through the shingle, and its highest part could hardly have been deposited much above the level of the sea, which, as the shingle shows, must have been near. A rise of land to the extent of 70 or 80 feet appears, therefore, to have taken place since the deposition of the brick-earth in which the flint implement was imbedded. The peat-beds, and the gravel and brick-earth over them, must have been formed at or above their present level and subsequent to the upheaval. ”

“ But if the great height attained by the gravel-covered plains is evidence of an antiquity far greater than that of the Milford Hill, and other high-level valley-gravels, the uniform surface of the tableland points to a continuance of similar conditions from the time of deposit of the highest gravels down to that of the gravel containing flint implements at Bournemouth, Lymington, Hill Head, &c. ”

“ The physical features of the country, and its superficial deposits, are so closely connected that they must be considered together. The New Forest, and the neighbouring country between Poole and Southampton Water, is characterized by high level plains, very generally covered with gravel or brick-earth. ”

“ The brick-earth, where it thins out over the thick mass of shingle-gravel, is eroded and overlain by a drab-coloured loam, which caps the shingle-gravel throughout, and extends partly over the other deposits to be noticed further on. A little to the north of the Coast-Guard Station, where the cliff loses height, the deep red-brown shingle- gravel is overlain by a white shingle, the junction being slightly irregular, and dipping about 3° northwards. In a short distance a peat-bed appears beneath a more clayey gravel, which takes the place of the white shingle ”

“ From the coast to the escarpment the ground has a uniform inclination of about 20 feet per mile, or one-fifth of a degree with the horizon. The surface is generally covered with gravel, which appears to thicken as the ground drops towards the valleys; the sides of the valleys are free from gravel, and the bottoms contain a gravel much mixed with locally derived clay and marl, and distinct from that covering the plains. ”

“ Large areas of the plains at the highest levels appear to have remained quite unchanged, while close by deep valleys have been scooped out, and high escarpments have been formed by what cannot have been any other than subaërial causes, and while large tracts of land have been gradually removed by the action of the sea on the neighbouring coast-line. ”

“ The gravel varies but little in character or composition over the area which has now been described; it consists almost exclusively of chalk flints, little rolled and often perfectly fresh. There is always, however, a proportion of tertiary pebbles; and where, as between Bournemouth and Christchurch, extensive pebble-beds occur in the underlying tertiary strata, the proportion of pebbles in the gravel is considerable. ”

“ That the gravel plains of the New Forest and the neighbourhood are portions of a tableland rising slightly to the northward and attaining an elevation of 420 feet: and that the remains of similar tablelands exist on the east side of Southampton Water, and, in a more fragmentary state, in the Isle of Wight, having a slope greater and in other directions. ”

“ Acheul, are equally manifest. Adopting the supposition that the Avon flowed to the sea by Spithead, it is not difficult to trace a connexion between the Sussex and the Hill-Head gravels and the Fisherton beds. The gravel bordering on the north shore of the Solent carries on the Hill-Head gravel to Lymington, where an oval flint implement has been obtained from it, and on to Milford. Beyond this the coast is exposed to the open sea, and has been cut back, so that none of the lower level remains until the Avon valley is reached, six miles to the westward. ”

“ Sir Charles Lyell was inclined to ascribe the formation of the gravels described to the sudden melting of snow in great quantities. He referred to the presence of sarsen-stones as indicating that there was force enough to carry large masses. ”

“ On the plains about Beaulieu, and on the eastern side of Southampton Water, 6 or 7 feet appears to be the average thickness, while at low levels, as in the cliff-section between Southampton Water and Gosport, it is generally 10 feet, and sometimes 15 or 16 feet, and in a pit near Southsea at least 27 feet thick, extending to below the sea-level.
(d) No organic remains have hitherto been found in the gravel covering the plains. ”