40 THE HIGH-LEVEL LOESS OF EUROPE ; 



sedimentation necessarily depending upon the char- 

 acter of the lands over which the waters spread. 



We must bear in mind the topographical conditions 

 prevailing at the time. At the close of the glacial 

 period when those changes took place, glaciers de- 

 scended from all the great mountain ranges of Europe, 

 and annual inundations, caused by the melting of the 

 snow, brought down large quantities of mud and silt 

 which was deposited on the flanks of the chief river 

 valleys. It is this which constitutes the fluviatile 

 Loess of the valleys of the Ehine, the Danube, the 

 Seine, the Ehone, and other rivers. This however 

 only forms local deposits and is confined to the valleys. 



But there is another and larger deposit of Loess to- 

 which such an origin cannot be ascribed, for this 

 latter is not confined to the river valleys, but is found 

 on the dividing watersheds and on the high plains 

 separating the river basins. In the north of France 

 this high-level Loess is found at heights of 400 to- 

 600 feet, and in the neighbourhood of Lyons of 1,300 

 feet, whilst in the great upper valleys of the Ehine 

 and Danube it reaches to an altitude. of 1,500 feet, 

 and this is even exceeded further to the east, where 

 likewise it covers the extensive high plains of 

 Hungary and Southern Russia. 1 . 



As the ocean waters advanced over the submerged 

 surface, large portions of the older fine and slightly 

 coherent fluviatile Loess in the valleys would be 

 taken up by them ; while, as the level of the land 

 was lowered, the ice and the snow on the mountain 

 1 See Appendix F. 



