and other Valleys of the East of England. 187 



arcs of the Kentish series, with precisely the curvature that their 

 position in those circles should present ; and as to others, they 

 are similarly exact portions of the arcs of the Isle of Wight 

 circles. A close examination of the common Ordnance sheets will 

 disclose these features more decidedly than on the small scale of 

 the annexed Map it is possible to distinguish them. Further, 

 these sheets will show other fragments of these arcs over the 

 centre of the Weald Valley, preserving their distinct character 

 through the enormous denudation to which that valley has been 

 exposed ; and I invite this close examination by the light of the 

 annexed Map as a guide. 



It appears to me, from the evidence of the great denudation in 

 the Weald Valley (which has, with these fragmentary exceptions, 

 destroyed the plications of the circles crossing that valley) having 

 accompaDied the rectilinear upheaval which is independent of the 

 curvilinear plications that I have been describing, that such rec- 

 tilinear upheaval was of subsequent date to the operations I have 

 been discussing. The operation of that local denudation has 

 been to denude and extensively remove the arcs crossing the 

 valley, and to deepen into their present state the gorges through 

 which the rivers of the Weald escape to the sea; and it has 

 therefore been undoubtedly posterior to the formation of those 

 arcs. And as the rectilinear elevation has, as it would seem, 

 been contemporaneous with that local denudation, I cannot but 

 regard the denudation which has given its present form to the 

 Weald Valley as subsequent to that forming the valleys of the 

 rest of the East of England, — the denudation over the East of 

 England having taken place when the island (then or soon after 

 a peninsula) emerged from the drift sea, and having ceased over 

 the greater part, which had become land, some time prior to the 

 cessation of the local denudation. This rectilinear upheaval and 

 local denudation I regard as contemporaneous with the forma- 

 tion of the higher (and perhaps of a part of the lower) level gravels 

 that fill the valley of the Thames, and which formed in that valley 

 the transitional stage between the events that constitute the 

 principal subject of this paper and the present state of things — 

 a stage when the isthmus connecting the peninsula of England to 

 the main was skirted by the estuary occupying the whole gravel 

 area of the Thames Valley on the north, and by the estuary or 

 inlet of the Weald Valley on the south, and when yet another 

 deep inlet occupied the area in Hampshire now covered by the 

 superficial gravel of Christchurch Bay, which ranges up to the 

 verge of the great rectilinear ridge that borders it on the south. 

 I believe also that abundant evidence exists to show that the 

 elevatory action which commenced with the convulsions I have 

 traced on the Map, and which by its sustained but diminished 



