1835.] FOSTEE AND XOPLEY BElSTUDAXrON OF THE WEALD. 



465 



And all this denudation has been due to the action of rain and rivers ; 

 for we have shown that the Medway deepened its valley gradually ; 

 and not only are there no traces of marine action, but had the sea 

 had access since the gravel was deposited, surely it would have 

 swept away such loose and incoherent deposits. If rain and rivers 

 could do so much, if they could cut out a valley 250 feet deep and 

 seven miles broad, surely we may allow that by giving them more 

 time they could scoop out valleys 500 feet deep ; in other words, that, 

 making every allowance for slight superficial inequalities produced 

 by marine denudation, all existing inequalities in the basin of the 

 Medway, including the Greensand escarpment and the Chalk escarp- 

 ment, are entirely due to atmospheiic denudation, that is to say, to 

 the action of rain and rivers *. If this holds good for the basin of the 



Fig. 9. — Mcqj of the Basin of the Mechvai/. 



20 l.j 10 o 4 a il i miles. 



The area shaded shows that part south of East Mailing Heath which is below 

 the 300-feet level. 



Medway, it may be applied to the whole of the Wealden area. The 

 reason why we have no traces of river-action at the higher levels is 

 that in the long lapse of time these old alluvia have themselves been 

 removed by subaerial denudation. 



Fig. 10. — General Section from Maidstone to heijond Boxley. 



Medway. 

 S.S.AV. 



K.N.E. 



Lower G-reens-iml. ttault. Chalk. 



a. Gravel. b. Gault Valley. 



It is not only the gravel at East Mailing that gives proof of vast 

 denudation. Eig. 10 (see also fig. 2) shows the position of the river- 



* The Wealden district does not appear to have been under water at all dur- 

 ing the Glacial period. Of course throughout this period frost and land-ico 

 must have had an immense effect in wearing down the surfawB of the country. 



