1870.] WOOD — TVT;ALD-T ALLEY DENTTDATION. 27 



ments as representing naarine cliffs ; but he did not attach sufficient 

 weight to the absence of any material of marine origin at their base ; 

 so that there was no evidence of the presence of the sea within the 

 Wealden area. He differed wholly from the author as to the age of 

 the gravels ; for beneath the gravels were silty beds containing Ele- 

 phant-remains. These gravels he was inclined to refer to a glacial 

 period, as they contain blocks such as could have been transported 

 only by the agency of ice. The elephants found in the valley of 

 the Wey are of the species {E. primigenius) which also occurs in the 

 Selsey beds; and he believed both to be of glacial age. As to the theory 

 of the denudation of the "Weald, he professed himself a convert to 

 the views of Messrs. Foster and Topley, and cited what was now 

 going on around Heligoland in illustration of denudation. 



Mr. Whitakee observed that the present absence of gravels along 

 parts of the valley of the Thames affords no proof of their not having 

 formerly existed. He pointed out the soft and friable nature of most 

 of the rocks of the Wealden, which would account for their absence 

 in the gravels. The only really hard rock was the Chert of the 

 Lower Greensand, which was abundant in the gravels of East 

 Kent. Angular flints occurred at the base of the chalk escarpment 

 wherever it had been carried back by denudation. The major valley 

 of theWeald had been spoken of ; but he denied that any such valley 

 existed ; it was merely a series of numerous small valleys. He 

 could not conceive the rivers flowing against the dip of the strata, 

 as supposed by Mr. Wood. He did not agree in the view of the 

 denudation of the Weald being such an enormous affair, but thought 

 that it might be due to comparatively small causes. 



The PnEsroENT pointed out that beyond Southend there was a 

 section precisely similar to that of Grays. It was a mistake to suppose 

 that pebbles from the Wealden area did not occur La the Thames 

 gravels. He thought that much of the denudation of the Wealden 

 area might have taken place before the glacial period. The presence 

 of Tertiary pebbles in the Wealden area might readily be accounted 

 for by their presence at the edge of the escarpment. 



Mr. Searles Y. Wood, Jun., in reply, justified himself for having 

 limited his observations to the northern part of the Weald, as it was 

 there only that it could be brought into juxtaposition with the Glacial 

 beds. He maintained that, under certain circumstances, no beaches 

 or marine beds were formed at the base of sea-cliffs. He pointed out 

 that in Postglacial gravels large blocks of rock were frequently 

 found, and protested agaiust limiting aU ice-transport to the glacial 

 period. He could not recognize the Selsey beds, vnth 150 living 

 species, some of southern character, and none extinct, as glacial. 

 The alleged softness of some of the Wealden rocks, when the great 

 excess both of the Lower-Greensand and Hastings-sand areas over 

 that of the Chalk was considered, did not at all remove the contra- 

 diction presented by the enormous preponderance of flint over sub- 

 cretaceous material in the East-Essex gravel. Like Mr. Austen, he 

 attributed the Wey gravels and the Selsey bed to nearly the same 

 period ; but that was a late postglacial, instead of a glacial one. 



