56 The Soils of Etigland and Wales 



Ashdown Sand, which makes the so-called "Forest Ridge," 

 a heathy ridge in the very centre of the Weald, still largely 

 covered with oak and birch wood. The Tunbridge Wells 

 Sand is partly very fine grained, like a clay, and largely 

 bears the damp type of oakwood. 



The Ohalk of the main outcrop, from southern Oxford- 

 shire north-eastward, dips below the overlying Tertiary 

 beds and appears again at the surface in the North 

 Downs. In the same way the Hampshire Chalk dips 

 below the Tertiaries in the south of the 

 =f.ri«f'^ county and the north of the Isle of Wight 



to reappear in the Central Downs of the 

 island. These two great chalk basins, known as the 

 London and Hampshire basins respectively, contain all 

 the English Tertiary deposits, except those which skirt 

 the east coast overlying the Chalk of Norfolk and Suffolk, 

 and which really form a north-eastward extension of the 

 London basin. 



Of the Eocene beds which form the bulk of these 

 beds deposits the London Clay is the most im- 

 portant. It yields a stiff soil with the usual 

 clay characters. Below it are the alternating sands and 

 clays which give variety to the fringe of country between 

 the chalk and the London Clay, while above it, forming 

 extensive tracts on the borders of Berkshire, Hampshire 

 and Surrey, and isolated patches to the north of London, 

 is the very light Bagshot Sand, bearing heath, and now 

 very largely subspontaneous Scots Pine. The Bagshot 

 beds of the Hampshire basin show a greater complexity 

 of alternating sands and clays. 



The Oligocene beds which come next are confined to 



south Hampshire and the Isle of IN'ight, 



Pliocene beds. ^^"^^^ tlie Miocene are absent from this 



country altogether. 



The Pliocene strata are the Tertiary beds which fi-inge 



the chalk on the east coast, and are thus entirely East 



