STRUCTURE OF THE S. E. OF ENGLAND. 69 



Several writers on geology have fallen into this 

 error, and indulged in the most absurd speculations 

 accordingly. A slight examination of the relative 

 position of the respective strata where in contact, 

 is, however, sufficient to show the incorrectness of 

 this hypothesis, and to prove that the Wealden 

 extends under the Chalk, both on the north 

 and south, as shown in the subjoined plan, and 

 in lignographs 2, 3. It is therefore certain that 

 the cretaceous formation was deposited upon the 

 Wealden ; and it is ecpially clear, that it origi- 

 nally extended, not only over the entire district 

 between the North and South Downs, and was 

 connected on the west with that of Hampshire and 

 Wiltshire, but also that it filled up the space now 

 occupied by the British Channel, and was united 

 with the chalk of the Isle of Wight and of the 

 Continent. 



South 

 Downs. 



Chalk Formation. 



North 

 Downs. 



Wealden Formation. 



If we assume the original position of these 

 ancient fluviatile and marine formations to have 

 been as represented in the above diagram, and sup- 

 pose that the middle portion of the chalk, a, a, were 



