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oil the Supra-Liassic Sands, the action of surface-water in 

 forming combes in the soft material of which the Sands are 

 composed is more strikingly manifest. As an illustration, I 

 may refer to the gorge on the south-west side of Cam Down. 

 Originally a cart track was made down the slope from the 

 quarries on the summit, and where it passes over the OoUte it 

 remains nearly level with the surface, but in the slope it has 

 disappeared as a track, and has been turned into a ravine in 

 the Sands, which at its lower end is thirty feet deep.* 



The views which I have expressed in reference to the action 

 of the streams, may, if adopted, possibly lead to the elucidation 

 of another somewhat diificult question, which has from time to 

 time attracted the attention of Geologists. I refer to the 

 ancient Gravel beds on the upper part of the slopes of the 

 Coftes wolds. The Gravels, as is well-known, are very little 

 worn, sometimes not worn at all, and by way of distinguishing 

 them from the drifts of the vale, we call them angular or 

 sub-angular Gravels. Occasionally they are found regularly 

 stratified, but this is not their general condition. Formerly 

 they were called Sea-beaches ; then their marine origin was 

 disputed, and the term " so called Sea-beaches " was apphed to 

 them. Now they are regarded as the result of the disintegration 

 of Oolitic rocks, by atmospheric influence. This view of their 

 origin is reasonable, and probably correct, but it does not explain 

 the cause of their being found only in certain localities. If we 

 consider the result of disintegration alone, we ought to find 

 these Gravels as talu at the base of the Freestones of the Inferior 

 Oolite, and of the Great Oolite in all the valleys, but they are 

 found at various elevations, ranging from 200 to 700 feet above 

 the sea ; sometimes they are deposited at the base of the rocks 

 from which they were derived ; sometimes as low as the Upper 

 Lias. The beds are of varying thickness — the one at Hyde is 16 

 feet. I attribute these deposits to the streams which brought 

 the Gravels down the valleys, and left them in positions in which 



* The dry valleys of the Chalk formation may owe their origin to conditions 

 analogous to those of the Cotteswolds. A stratum of Tertiary Clay spread over 

 the chalk would inevitably lead to the formation of combes by means of the 

 surface drainage. The denudation of the Clay would leave the combes dry. 



