466 



PROCEEDOfGS OF THE GEOLOGICAL SOCIETY. [Apr. 25^ 



Hole valley of such, a great denudation as Mr. Prestwich supposes 

 to have occurred in the valley of the Somme, although we have in 

 both places drift associated with the bones of extinct Mammalia, 

 and with rude flint implements at very high levels above the sea. 



Fig. 1. — Longitudinal Section of Mary church Valley. 



E.KE. W.S.W- 



Marychurch. 

 i 3 soft 



«yoft 



* Pholas markings. 



The raised beaches fringing the coast-line in the south-east of 

 England, north-east of Prance, and south-east of Devonshire, as 

 well as the gravels, &c., fronting at similar heights the transverse 

 valleys wMch open in both districts into the English Channel, place 

 all these localities in close geological relationship. 



The presence of calcareous deposits on the sides of tlie chalk val- 

 leys in Erance, described by Mr. Prestwich, is matched in Devonshire 

 by a calcareous deposit which has cemented loose blocks of limestone 

 on the solid rock. 



At Watcombe,figs.2 &3, one mile nortli-east of Kent's Hole Cavern, 

 the analogy is still more complete, if I am correct in the suggestion 

 that this may be a thick bed of freshwater loess covering the angu- 

 lar drift below it, and that both drift and loess are derived from the 

 ruins of the Triassic rocks close by. The clay in question is ex- 

 tremely fine, and must have been deposited from a most tranquil 

 laket; and yet it is now raised more than 200 feet above the present 

 sea-level. 



Eig. 2. — Longitudinal Seetion along the Valley of Watcomhe. 



w.s.w. 



s.s.w. 



Level of Valley. TumWed Eock. 



j^ig. 3. — Coast-section from Babbacoinhe to Watcomhe. 



E.KE. 



X Eorings. 



Seasoning on so many parallel circumstances, we must admit a 



<}lose analogy between the former condition of the Devonshire and 



Somme valleys during the gravel-period, and may consider that the 



surface of the Devonian limestone has been so little affected by the 



t This loess clay is about to be used for terra- cotta figures. 



