596 ME. 0. A. SHETJBSOLE ON SOME HIGH-LEVEL [NoY. 1 89 8, 



There are scarcely any pebbles, and the flint-fragments are usually 

 angular. They are whitish externally, and mostly black and grey 

 internally. The gravel shows little, if any, sign of stratification, the 

 general arrangement being a series of whorls or curves. In places 

 near the base patches of gravel in a chalky paste occur, as shown in 

 the appended sketch (fig. 2). These chalky patches resemble, although 



Pig. 2. — Turner's Court gravel-pit, Wallingford. 



[Height of section = 12 feet.] 

 a = Unst ratified angular flint-grayel in ocbreous sand. 

 & = Similar gravel in marly paste. 



on a smaller scale, those occurring in stratified gravel at Tilehurst 

 Eoad, Eeading, described in a former paper.^ I am inclined to 

 think that, in some cases, these chalky patches may be due to the 

 irregular action of solvents subsequent to the formation of the 

 gravel. 



At Gould's Grove, between Turner's Court and Ewelme, there is 

 a somewhat similar section, and another at Ewelme itself; but in 

 these cases there was much less irregularity in the deposit. 



At Little Stoke, 3| miles north of Goring, the valley-gravel is 

 composed of very similar materials. In a gravel-pit there, only one 

 quartzite-pebble was found : on the other side of the Thames at 

 Moulsford such pebbles are very abundant in the gravel ; while a little 

 farther north the quartzite-pebbles are found on both sides of the 

 Thames, as at Brightwell Barrow, near Wallingford (371 feet above 

 Ordnance-datum), and Primrose Hill, near Drayton (246 feet). At 

 the last-named locality the Quartzite-gravel may be seen in the fields 

 on one side of the road, and the flint-gravel on the other. 



What are the age and origin of this flint-gravel ? Some barrier 

 has evidently prevented the Quartzite-gravel from having access to 

 the plateau north-west of the escarpment of the Chilterns. I can 

 only suggest that this barrier was the escarpment itself, and that this 



^ Quart. Journ. Geol. Soc. vol. xlvi (1890) p. 582. 



