188 Mr. S. V. "Wood on the Formation of the River- 



and more slowly acting force brought the anticlinals above the 

 sea, and from stage to stage converted the gravel-beds into the 

 low hills of the valleys, and the channel-bottoms into marsh, 

 reducing those channels to the narrow courses in which they now 

 run, is still in operation, and that it has produced appreciable 

 results in elevation even in the short period that has elapsed 

 since the Roman invasion. 



To prevent misconception, I would also observe that the same 

 rectilinear movements which in the Weald Valley supervened on 

 the circular divergences described, appear to me to have also su- 

 pervened on the same divergences in the south of Hampshire and 

 Dorsetshire, by which much of the elevation there appearing at 

 first sight as due to the focus of the Isle of Wight circles has 

 been added to the elevation that introduced these circular phe- 

 nomena, and that it is by a combination of the two that the 

 present highly inclined condition of the central line of that isle, 

 and the consequent enormous denudation over that line, have 

 resulted. I have endeavoured to represent the effect of this 

 compound action in Section 1 (PI. I.), in which all the beds from 

 the Wealden upwards are represented in the position they now 

 actually occupy ; but the tertiaries from the base of the Headon 

 series upwards are connected by dotted lines with the arc of 

 upheaval, of which they still remain an almost undisturbed part, 

 the tertiaries beneath that series, together with the cretaceous 

 beds, having been brought into their present almost vertical con- 

 dition and squeezed against the Headon series by the subsequent 

 rectilinear movements referred to. It may be a startling reflec- 

 tion to the residents of some portions of the south coast, that the 

 places on which their towns stand have, as I believe, been up- 

 heaved sharply and locally to an extent of between 2000 and 

 3000 feet by these rectilinear movements during and since the 

 time when the men whose remains occur in the high-level gravels 

 of the Somme dwelt on the banks of that river. Further, the 

 phenomena disclosed by the Map seem to point to the formation* 

 of the two series'of circles as not absolutely simultaneous, but 

 that some interval, although possibly of the very shortest or mo- 

 mentary duration, elapsed after the upheaval of the Kentish and 

 before that of the Isle of Wight centres. 



If the foregoing views are well founded, the results concur 

 with the inference I have drawn from, amongst other evidence, 

 that of the deposit of theu pper and lower drift : viz., that over the 

 East of England no irregularities of surface existed prior to the 

 close of the drift epoch, other than those produced by erosion ; 

 and that, with the exception of the inequalities resulting from 

 that cause, the entire surface covered by oolitic, cretaceous, and 

 tertiary deposits remained, until the outburst of these convul- 



