222 NEOZOIC TIME. [CHAP. XI. 



layers of false stratification in the Kentish and Surrey 

 beds is northward, or from the direction of the presumed 

 island, at angles varying from 10 to 35 degrees. 



Throughout the time of their accumulation, and of the 

 overlying Oldhaven Beds, there is little evidence of any 

 general subsidence ; the probability is that the land was 

 practically stationary, but that the coast-lines were being 

 constantly altered by the action of tides, currents, and 

 winds, just as the eastern and southern shores of England 

 have been altered within historic times by the same 

 agencies, one tract of coast being worn away and cut back, 

 while at other localities the materials so obtained were piled 

 across the mouths of rivers and in front of low-lying shores. 



This stationary period was succeeded by one of decided 

 and continuous subsidence, and the basement bed of the 

 London Clay represents the final distribution of the sand 

 dunes and shingle banks beneath the waters of the ad- 

 vancing sea, these barriers being destroyed, and the whole 

 lacustrine area behind them being at once covered by the 

 sea of the London Clay. 



This submergence in all probability carried the Wealden 

 island far below the sea-level, for there seems no good 

 reason to doubt that the London Clay extended across the 

 whole of south-eastern England, and over the north- 

 western part of France, at least as far as the latitude of 

 Dieppe. 1 How far westward the coast-line was carried at 



1 The sands on the North Downs, supposed by Mr. A. Irving to be 

 Upper Bagshot, are probably post-Eocene. How far the Ypresien 

 clay of Belgium reached southwards is uncertain. Professor Gosselet 

 indeed thinks it did not pass into France, and in his map (" Esquisse 

 Geol. du Nord de la France," PI. XII. A), shows a broad tract of land 

 extending from the Boulonnais to the Ardennes at this epoch ; but in 

 this, as in other cases, his restoration seems to have been constructed on 

 the assumption that the present boundaries of the beds are nearly coin- 

 cident with their original limits, very insufficient allowance being made 

 for subsequent denudation. 



