GEOLOGY OF FOLKESTONE THE GAULT, 



203 



onward progress of tlie waters ; the flood-tide striking against wMcli 

 would bend over to one side, as indicated by tbe direction-arrows in 

 tlie lignograpb, until tbe time of ebb, wben it would flow out witb a 

 strong current, carrying with it the debris, and thus the cause of the 



Lign. 19.— Theoretical Map of the Action of the Channel Tides in the Denudation of the 



Wealden Area. 



The outlines of England and France have been adopted as they are now delineated on 

 ordiaary maps, and no attempt at restoration has been made. At the "peninsula" period 

 referred to the channel must have been narrower ; but the outhnes of the coast would pro- 

 bably have so nearly approximated to the present coast-hnes as to render them sufficiently 

 accurate for the elucidation of our theoretical speculation. The dotted curves indicate the 

 hourly progress of the tidal wave ; the interrupted hues with occasional arrows show the 

 chief direction and force of the tidal stream in flowing and ebbiug, by which the denudation 

 of the Weald is presumed to have been effected. The existing coast-liue of the Wealden area, 

 the Boulogne coast, and the cliSs of Dover and Calais are indicated by faint shaded outhnes, 

 as are also the river-vaUeys, or cross-fractures of the Weald district, the central ridge of 

 which, or axis of elevation, is shown by the hne composed of alternate bars and dots. 



clean surface of the Weald and the general absence in the few superficial 

 deposits of any organic remains, the denudation being a tidal one. 



The cross-fracture vaEeys on the south side of the Wealden anti- 

 clinal, or central ridge of elevation, would have afibrded numerous 

 openings on the English side of the channel- crack, up which the pent 

 tide would have poured, and hence the reason why the greater denu- 



