Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/915

 alders. When the Scotch fir occurs it is generally with the oak, with the exception of the submarine forest near Rossall, where there appears to be a distinct horizon of Scotch fir at the base of the peat, under another tree-surface consisting of oaks. In this, as in all the other sections in Lancashire and Cheshire, a seam of hazel occurs near the top of the peat. The wood of this is invariably of a peculiar red colour, and is called by the peat-cutters " red wood."

It is thus clear that the whole of the lowlands of Lancashire and Cheshire, as well as the slopes of the Triassic hills, were covered, before the growth of the peat, with forests, including oaks of the largest size, pollard ashes, beeches, alders, yews, firs — that after this the growth of peat ensued, varied by occasional seams of brushwood, of which shrubs of the genera holly, hazel, and spurge played the most important part ; and on the surface of the peat, at the present day, the spurges and the willows, in the drier portions, are gradually adding their tale of leaves. The peat was probably formed during very gradual subsidence, the seams of brushwood indicating pauses.

Upper Scrobicularia-clay. — Resting on the surface of the peat, on both sides of the river Wyre between Fleetwood and Blackpool, and at the mouth of the river Alt, near Hightown, is a deposit of tidal alluvium, reaching a thickness of nearly 30 feet south of Fleetwood. At a depth of about 8 feet, twenty years ago, a great number of Roman coins were found in this deposit in the latter district. The surface of the spot where the coins were found is about 2 feet above high-water mark; and the " Scrobicularia-clay" is covered with from 3 to 4 feet of blown sand. The surface of the clay is therefore rather below the sea-level. As the deposit contains the estuarine shell Scrobicularia piperata at all depths, including that of 8 feet, as proved in borings, it follows that, when the coins were lost by the Romans, the land could not have been higher than at present, as has been proved by Mr. Geikie to have been the case in Scotland.

By the side of a brook which runs up from Freckleton Point, in the estuary of the Mersey, near the town of Kirkham, is the site of a Roman bath, near which a splendid Roman bronze shield was found, now in the British Museum ; as this bath is only about 7 feet above high-water mark, it would tend to prove that the country is not lower now than it was in Roman times ; and there is therefore little doubt that the level of the country has not mate- rially changed, and that the Romans lost their money scrambling and slipping over the soft salt-marsh mud.

Blown Sand. — The blown sand of Lancashire, south of the Ribble, resembles that of Cheshire. It is composed of very fine grains, and contains black specks, probably of hornblende. The dunes between Liverpool and Southport rise to a height of 70 or 80 feet above the level of the sea, and between Lytham and Blackpool to a height of from 60 to 70 feet ; but they seldom rise above 40 feet near Fleet- wood. Where the base of the sand-hills is seen resting on the peat, as at Southshore, it is found to consist of the " Bythinia-mnd," as in Cheshire. In the sand dunes north of the Ribble, especially near

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