Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/537

1869.] spot for studying the prevailing character of the hard stony clay (Lower Boulder-clay). In the lower part especially, it looks like a kneaded mass of clay, grit, and stones of various sizes. Grains and small fragments, as well as good-sized stones of quartz, here enter considerably into its composition, and give it a speckled appearance. Many of the stones are igneous or metamorphic: some are well rounded; but generally speaking they appear little more than blunted or rubbed, as if they had been pushed along. Most of them are more or less scratched and striated.

Fig. 3. Transverse Coast-section of Drift to the north of Uncle Tom's Cabin. (Cliff about 70 feet in height.)

A. Upper Boulder-clay. B. Middle sand, gravel, and " rockery." C. Lower Boulder-clay.

e. Postglacial Deposits.—On the coast south of Foxhall Inn, and extending far in a southerly direction, a Postglacial clay may be traced. Near its northern termination, and some distance out at sea, I found a thin remnant of it resting on the Lower Boulder-clay. It is well exposed on the shore near the promenade now in course of being constructed (December 1868). It may be about 15 feet in thickness. It is of a very soft and yielding character, and here and there exhibits curved lamination. It is more or less charged with decayed vegetation, and in many places is full of very small stones, generally smaller than a pea. The lower part, called Scotch slutch, is of a light bluish-grey colour; the uppermost foot, called white ore or stepmother's jag, of a very light grey hue. It includes at least one thin layer of peaty matter. On the coast it is overlain by a bed of peat between 2 and 3 feet thick. Inland it varies in thickness, and here and there thins out, as if it had been accumulated in hollows, and it is generally overlain by peat, which in many places is covered with stratified sand. The latter would appear to have been deposited when the land was slightly lower relatively to the sea than at present, though it ought not to be forgotten that this area is still subject to high-tide inundations. A part of the low ground behind Southshore was formerly occupied by Marton Mere, in the bed of which, the Rev. Mr. Thornber informed me, the skin of a British canoe (the wickerwork decayed) was found many years ago.

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