Page:Transactions of the Geological Society, 1st series, vol. 2.djvu/251

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Mr. Webster on the Strata lying over the Chalk.

great attention paid to agriculture in our country, have much diminished the quantity of morasses and ancient depositions of this kind; and the great superiority of coal as a fuel, and which gives us a natural advantage over other nations, has rendered turf of little value.

In Lincolnshire however the quantity of marsh land is prodigious; and the well known and accurately described submarine forest, yet to be seen in that county, has already excited the attention of some of our naturalists.

The subject of the Fossil organic remains, found in the gravel, has been already so ably treated by a naturalist eminently qualified to do it justice, that I should have left the subject in better hands, did it not form so essential a part of an account of our upper strata, that to have omitted it entirely would have rendered some of the following observations less intelligible.

From the view which I have taken of the subject, it will be seen that I consider the fossil shells found in the gravel, as well as the gravel itself, as exhibiting proofs of the detritus or ruin of ancient errata. Hence specimens of all those fossils which belonged to the strata over the chalk may be expected to be found in it.

I am aware that the perfect state in which many of these fossil shells yet remain, has been considered as a proof that they have never suffered a removal, but that they have lived and died upon the spots where they now are.

That this is the case with some of the upper beds containing fossil shells, as the thin clay strata of Woolwich, Plumstead, &c. and perhaps of other places with which I am not acquainted, there can be no doubt. But the same argument will not apply to such as are surrounded by, and enveloped in, beds of water-worn pebbles and sand, which is evidently a confused mass, the consequence of ancient

Vol. II.2 h