186 ME. H. W. MOXCKTOiSr ON SOME GRAVELS [MaV 1 898, 



not been much rolled or waterworn. These I found in a pit at 

 Gravel Hill, one of the northern spurs of the plateau of the East- 

 hampstead Plain, and ^ mile east of the Easthampstead Caesar's 

 Camp. The two large blocks in the photograph (tig. 1, p. 185) are 

 sarsens. I have seen similar flints in other pits on this plateau — at 

 Wagbullock Hill, for instance. 



These flints are stained of the brown colour, which, according to 

 Sir Joseph Prestwich,^ shows that they have not been derived 

 directly from the Chalk, but from an older drift. At no time, how- 

 ever, have they been much waterworn, and the older drift must, 

 I should suppose, have been somewhat of the nature of Clay-wit h- 

 flints. 



The Chalk-outcrop nearest to Gravel Hill is 7| miles a little W, 

 of N., but the gravel is shown by its composition to have come from 

 the south or south-east, and the nearest Chalk at the surface on that 

 side is 10| miles distant, close to Tongham. These fl.int8 must 

 therefore have travelled 10| miles, and of course may have come 

 from a still greater distance. Now Sir Charles Lyell, speaking of 

 the South Hampshire gravel, says, ' The occasional occurrence of 

 unrolled chalk-fl.ints in the gravel, in places where the}' must have 

 travelled 12 miles from their nearest source, also implies the aid of 

 ice-action.' ^ 



Sir Charles Lyell also considered the presence of large angular 

 sarsens enveloped in gravel as evidence of ice-action,^ and this 

 evidence we find on the Chobham Eidges plateau ; but perhaps I 

 may be allowed to deal with the sarsens in some detail. 



Mr. W. H. Herries has described some blocks of white sandstone 

 which he saw in the large pit at St. Ann's Hill, Chertsey ;* and I 

 have seen such blocks there unwaterworn, and no doubt from Lower 

 Bagshot Beds. 



Sir Joseph Prestwich considered that the greater number of the 

 sarsens scattered over parts of the South of England were from the 

 Beading Beds, and with this I think most of us agree ; he, however, 

 also records sarsens from the Bagshot Beds, though he says that he 

 has never seen them in sandpits or roadside-cuttings.^ 



Mr. W. H. Herries says that he has 'never seen a sarsen-stone 

 in the Upper Bagshot Beds .themselves,' and that the example at 

 St. Ann's Hill already referred to is ' the only instance of stone 

 resembling sarsen-stone ' that he has seen in the Bagshot Beds.^ 

 Nor have I ever seen a sarsen in situ in undisturbed Bagshot Sand ; 

 and, with the exception of the St. Ann's Hill specimen, I never 

 remember seeing a sarsen which had not been more or less weather- 

 worn or waterworn. 



1 Quart. Journ. Geol. Soc. toI. xlvi (1890) p. 156. 



■^ ' Antiquity of Man,' 4th ed. (1873) p. 222. 



^ Ibid. pp. 182, 221, 



* Geol. Mag. 1881, p. 171. 



'_ Quart. Journ. Geol. Soc. vol. x (1854) p. 129. 



^ Ojj.Jam cit. p. 174. 



