5 7 8 Boulder- Clay. 



and entirely natural loamy silt, somewhat of the same 

 character, follows the course of the Ouse, and, to a 

 great extent, covering the fertile vale of York, passes 

 out to sea in the plains that border the Tees. 



On the west coast the wide plains of the Fylde in 

 Lancashire, north and south of the estuary of the Eibble, 

 in some respects resemble those of the Wash. 



Such is a very imperfect sketch of the general nature 

 of the soils of Great Britain, and of their relation to the 

 underlying rocks. We have seen that throughout large 

 areas, the character of the soil is directly and powerfully 

 influenced by that of the rock-masses lying below. It 

 must be borne in mind, however, that the abrading 

 agencies of the Glacial period have done a great deal 

 towards commingling the detritus of the different 

 geological formations, producing widespread drift 

 soils of varied composition. This detritus is far from 

 being uniformly spread over the island. In some 

 districts it is absent, while in others it forms a thick 

 mantle, obscuring all the hard rocks, and giving rise to 

 a soil sometimes nearly identical with that produced by 

 the waste of the underlying formation, and sometimes 

 of mixed clay and stones, as in Holderness. Thus the 

 Boulder-clay, though often poor, sometimes forms soils 

 of the most fertile description, as for instance in certain 

 upper members of the formation in parts of the Lothians, 

 and in the chalky Boulder-clay of Norfolk and Suffolk. 



