60 Ths Soils of England and Wales 



parts of tidal estuaries which are silting up, and of which 

 the lower parts are accumulating tidal mud. The most 

 extensive area of this kind of peat forms the region known 

 as " the Fenland," lying to the south of " the Marshland " 

 and corresponding with the upper portions of the old 

 estuaries of the Ouse, the Nen, the Welland, the Witham, 

 and their tributaries. The upper parts of the old estuaries 

 of the Bure, Yare and Waveney in east Norfolk^ form 

 other areas of the same kind, much less extensive, but less 

 altered from their original condition. 



The present surface-peat of the upper parts of other 

 old estuaries, e.g. the peat of the Somersetshire "levels" 

 and round Morecambe Bay (north Lancashire), is of the 

 heathy type (i.e. much poorer in mineral salts), though in 

 some cases this surface-peat is built up on old peat of the 

 former tjrpe (see p. 246). 



The hill peat, so common on the badly drained slopes 

 and plateaux of the Pennines, in Wales and in Scotland 

 and Ireland, is of the acid type, poor in mineral salts. 

 Much of this peat has been formed on the sites of ancient 

 forests. 



The constant variation from place to place of the 

 English soils will be obvious from the foregoing account. 

 It is clearly impossible briefly to summarise their distri- 

 bution. Some of the most impc>rtant areas of the various 

 kinds of soil are given below. 



Organic soils. Mild peat of upper parts of old estuaries 

 fed by waters rich in bases. Acid peat of hill plateaux 

 and slopes in the north and west, and lowland moors. 



Sands and gravels. Blown sand of various places on 

 the coast. Valley and plateau gravels overlying various 

 secondary and tertiary rocks. Pliocene "crag," etc. — 

 east Norfolk and Suifolk. Bagshot sand — mainly south- 

 west of London — and other Eocene sands of the Hampshire 

 basin. Lower Greensand — Weald and the east Midlands. 



