Page:A Treatise on Geology, volume 2.djvu/76

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62
A TREATISE ON GEOLOGY.
CHAP. VI.

au N. E. de Staveren, étoit encore un bois en 489; et ce lac, ne pourroit etre désséché aujourd'hui que par artifice." The soil of Holland, which has been longer enclosed in banks than Friesland, is on a lower level. The same explanation applies to the fact, well known near Lynn, that the land which has been regained since the Roman sea banks were made is on a higher level, and of greater value, than that which was enclosed by the Romans; and outside of "Marshland," as this tract is called, the new foreshores are sometimes still higher.

For the following interesting fact we are also indebted to De Luc:—

"Près de la Scanie, dans la mer Baltique, est une isle nommée Bornholm, environ née de collines de sable, dont le milieu est une vaste Tourbière, sous laquelle on trouve quantite de sapins, couches de la circonférence au centre. Cette derniere circonstance, pour le dire en passant, prouve toujours mieux que ces arbres n'ont pas été abattus par des inundations, mais par les vents. Ici, plongeant du haut des collines, et tout le tour en differens terns, les vents out renverse ces arbres quand la tourbe a été profonde et molle, et les ont ainsi couchés de la circonférence vers le centre." (Hist. de la Terre, Partie X. Lettre cxxvi. tom. v. p. 222.)

He applies this fact to explain the origin of coal from peat, and enters into a short explanation of the mode by which he conceives the submerged peat was covered by the argillaceous schistus of its roof, enveloping the plants then growing on the peat; remarking that both elevations and depressions of land happened before the final desiccation of our continents, and noticing the differences of the ancient and living flora of the peat moors.


Turf Moors.

Submarine and subterranean forests are almost universally associated with peat, or turf, as it is called in the north of England, and indeed, generally, they constitute