POSTGLACIAL, &-r., DEPOSITS OF CONTINENT. 481 



and by implements and weapons of Neolithic types. In the 

 valley of the Somme the break between the Palaeolithic and the 

 Neolithic deposits is very clearly shown. The excavation of the 

 valley had been completed before any of the peat began to form ; 

 the great flooded rivers and inundations had disappeared, and 

 the surface of the ground had assumed very much its present 

 conformation long before the oaks and yews of the peat had 

 commenced to flourish in the valley of the Somme. 



Submarine peat and trees have been noted at many points 

 upon the coasts of Normandy, as at Villers in the Calvados, 

 between the mouths of the Orne and the Seule, at Criquebeuf, 

 near Vaches-Noires, near Cherbourg and La Hougue, and along 

 all the west coast of Contentin. The same phenomena are 

 continued upon the coast of Brittany, as at St. Malo, Dol, at 

 Eodeven, near Plouescat, at Saint-Pierre-Quilbignon in the Bay 

 of St. Anne, near Morlaix in the Bay of Fresnaye, and other 

 places. Trunks of trees occupying the place of growth have 

 likewise been observed under the level of the sea as far south 

 as Arcachon (Gironde), and accumulations of vegetable cUbris 

 and clay are prolonged under the sea-level at the mouth of the 

 stream Mouligna near Biarritz. 1 No thorough examination 

 appears to have been made of any of the submarine peat and 

 trees of the districts just referred to, and we cannot therefore be 

 certain whether or not they are of the same age as that of the 

 Somme and the Flemish coast. Nor, so far as I know, have 

 they disclosed a succession of beds like that which is furnished 

 by the postglacial and recent deposits of Cornwall. Some 

 antiquarians, indeed, maintain that the submarine trees that 

 occur along the coast between St. Malo and Cape La Hougue 

 are the relics of a broad belt of forest-land which was over- 

 whelmed by the sea in the year 709, although the submergence 

 was not completed till 860. There may possibly enough be 

 some truth in these statements, but it is questionable if the 



1 Delesse : Lithologie des iters de Frcmce, etc. , p. 437 ; Adouin and Milne 

 Edwards : Recherches pour servir A VHistoire Naturelle du Littoral do la France, 

 etc., t. i. p. 193, et seq. See also Peacock: Phys. and Hist. Evidences for Fast 

 Sinkings of Land, etc. 



2i 



