On the Agricultural Geology of England and Wales. 491 



Yorkshire and Lincolnshire, now proved to belong to this part of 

 the series. The greensand, as at present constituted, is a com- 

 pound as incongruous as the great image with a head of gold and 

 feet of miry clay. Connected zoologically with the chalk, and 

 forming part of the cretaceous group, it is not easily separable, 

 in its lower portions, from the local wealden beneath it. There 

 are few of the secondary strata which undergo greater changes 

 horizontally within short distances. The gault is at one place 

 lost in the upper greensand ; at another the greensand is re- 

 placed by the gault ; at a third both appear to merge in the 

 chalk. Who will venture to assign agricultural characters to such 

 a Proteus, even excluding the superficial deposits by which it is 

 frequently covered ? Mr. Morton ascribes its fertility, in the 

 Vale of White Horse, to a thin covering of the chalk-marl and 

 greensand, and admits a considerable intermixture of angular 

 and rolled flints in the soils which cover it in its range through 

 Oxfordshire, Buckinghamshire, and Bedfordshire. In Norfolk 

 the gault exists only as a thin band, so covered with the erratic 

 deposits that it only appears as a few small disconnected patches 

 with the red chalk above and the carstone below. Further north 

 its geological relations become still more obscure, and descriptions 

 of its agricultural characters perfectly unintelligible. In Cam- 

 bridge and Huntingdonshire it appears impossible to dravv a line 

 between those of the gault and those of the Kimmeridge and 

 Oxford clay. 



If we confine our attention to the lower greensand, in districts 

 the most free from superficial accumulations, we find on it the 

 extremes of barrenness and fertility. Dersingham Heath, Nor- 

 folk, Leith Hill and Hindhead, Surrey, Woolmer Forest, Hamp- 

 shire, are on the same part of the series as the productive orchards 

 and hop-grounds of the vale of Maidstone, and the rich grazing- 

 grounds of the vale of Aylesbury. They who point out the 

 gardens of Sandey and Biggleswade as instances of greensand 

 fertility, state at the same time that it is in a great measure the 

 result of superior cultivation ; while other agricultural authorities 

 say that the fertility is only present where a deep soil has accu- 

 mulated from the wash of the neighbouring hills. 



The Oolites and Lias. — In tracing the oolites from Yorkshire 

 to the south, we find, in many instances, a close coincidence be- 

 tween established agricultural districts and geological areas. In 

 others all the formations between the chalk and the lias are 

 blended into one district, with the proviso that it contains a 

 variety of soils too numerous to be traced more particularly. In 

 some counties no agricultural districts are laid down on the maps, 

 but characters indicating loam, clay, gravel, &c., are scattered 

 irregularly, and without reference to the strata, over those parts 



