Vol. 54.] GRAVELS IN BERKSHIRE AND OXFORDSHIRE. 587 



About 2 miles north-east of Greenmoor Hill, and at about the 

 same level, is the small patch of gravel which has been described 

 by Messrs. Monckton & Herries ^ and by Mr. H. J. 0. White.^ The 

 proportion of subaugular flints appears to be the same here as at 

 Woodcote. 



A mile south-west of Greenmoor Hill, where ' Cold Harbour ' 

 is marked on the Ordnance-map, the fields are thickly strewn with 

 a somewhat similar gravel, but it has no depth. The level at this 

 place is 541 feet above Ordnance-datum. 



The composition of these deposits is consistent with a fluviatile 

 origin ; and their position, so near the present breach in the escarp- 

 ment at Goring, has led me to suggest that they may be the relics 

 of an old river — possibly an early stage of the Thames. 



IV. The Quartzose Gravel. 



At a lower level than any of the gravels hitherto described occurs 

 a deposit which, as it invariably contains a large percentage of 

 quartz-pebbles, I have called the Quartzose Gravel, and this name 

 enables me to refer to it without making any assumption regarding 

 its precise age. This and the two gravels already described make 

 up the ' Westleton Shingle ' of Sir J. Prestwich. A section of the 

 Quartzose Gravel may be seen in a pit at the northern corner of 

 College Wood, about a mile north-east of Greenmoor Hill, near the 

 point marked ' Lodge ' on the Ordnance-map. It occupies the higher 

 part of the Goring Heath plateau, at a level of about 475 feet above 

 Ordnance datum. Purple and brown quartzite-pebbles occur here, 

 but in small proportion. Two fragments of old rock were found to 

 contain the impressions of fossils, one of which appeared to be an 

 Orthoceras. A somewhat similar gravel caps the Tertiary outlier of 

 Basildon, at 466 feet above Ordnance-datum, on the other side of the 

 Thames ; but it contains more of the purple and brown quartzite- 

 pebbles, and on that account some hesitation is felt in classifying it. 

 It has in fact been claimed both as Westleton and as Glacial gravel. 

 At a level only a few feet lower down, it is succeeded by a gravel 

 in which the purplish quartzites are abundant, thus presenting 

 conditions similar to those which were observed at College Wood. 

 (See fig. 1, p. 588.) 



The gravel on Ashley and Bowsey Hills, near Wargrave, has been 

 fully described by the late Sir J. Prestwich ^ and others. It is of the 

 quartzose type. The height of these hills is stated as 480 feet and 

 467 feet respectively. Purple and brown quartzite-pebbles occur 

 here, but they are rare, especially those of a larger size. 



The subjoined table (p. 589) will give an idea of the composition of 

 this gravel. The averages are obtained by counting the stones in a 

 representative portion of the gravel, and this method has been 

 followed in all cases. The gravel at Merrill Hill, Hatfield (380 



1 Proc. Geol Assoc, vol. xii (1891) p. 112. 



- Ibid. vol. xiv (1894) p. 11. 



3 Quart. Joura. C^eol. Soc. vol. xlvi (1890) p. 141. 



2t.2 



