Vol. 54.] OF TEE BAGSHOT DISTRICT. 191 



from that of the Chobham Ridges plateau down to the level of the 

 Thames. 



Sarsens, too, are found in gravels of very various levels. In 

 August 1897, I saw one in a pit 292 feet above Ordnance 

 datura, close to a ford over the Wishmoor Stream on Olddean 

 Common. Its size was 3| x 3| x 1| feet. It was tilted to the 

 south, above it was 4 feet of gravel, and there was a little gravel 

 under the northern end, while the southern end rested on sand. 

 The stone was somewhat waterworn, but still of a decidedly angular 

 shape. The gravel was roughly but distinctly stratified, and in 

 fact resembled, so far as I could see, the sarsens and gravel Avhich 

 I have been describing, more than 100 feet higher in level. 



In my paper of 1891 (Quart. Journ. Geol. Soc. vol. xlviii, 1892, 

 p. 42) I described sarsens in the middle of gravel at about this same 

 level, namely, 300 feet above Ordnance datum. 



I am inclined to look upon the gravel of Snelsmore Common, 

 north of jN^ewbury, and 400 feet above Ordnance datum, as practic- 

 ally contemporaneous with the gravel of the plateau of the Bagshot 

 district, and also of fluviatile origin. I was, therefore, interested 

 to hear Mr. H. B. Woodward ask at a meeting of this Society 

 whether some of the plateau-gravels near Newbury might not be 

 of Bagshot age.^ This remark seemed of especial interest to me, 

 as I consider the Chobham Ridges plateau-gravel coeval with the 

 Farnham plateau-gravel, in which flint-implements have been 

 found. 



But, first as to Snelsmore Common, I have noted small sarsens in 

 the gravel not lying horizontally, but more or less on end ; perhaps 

 this may indicate the action of river-ice. 



/Section at Snelsmore Common, near Newhury^ 4:00 ft. above O.D. 



1. Stiff reddish clay with stones ] 



2. Gravel, subangular flints, and pebbles, small sarsens | 3 ft. 4 in. 



on end J 



3. Coarse sand, yellow, orange, greenish, and white 1 ft. 6 in. 



4. Gravel, like bed 2 3 ft. 



There are small pebbles of quartz up to ^ oz. in weight, but they are rather 

 rare. In some places the gravel is well and evenly stratified, and in others it 

 is unst ratified. 



I pass now to the Farnham gravel, which I did not describe in 

 my paper of 1891. The highest of the Farnham gravels caps an 

 elongated plateau, with a level of from 360 to 380 feet above 

 Ordnance datum. It runs in a north-easterly and south-westerly 

 direction, and is about 5 miles south-west of the Fox Hills plateau, 

 which is at practically the same level above the sea (350 to 390 feet 

 above Ordnance datum). 



On the Geological Survey map the Farnham plateau is mapped as 



' Quart. Journ. Geol. Soc. vol. liii (1897) p. 437, discussion. , 



