Yol. 54.] HIGH-LEVEL GEAVELS IN^ BERKS AND OXON. 585 



39. On some High-level Gravels in Berkshire and Oxfordshire. 

 By 0. A. Shrtjbsole, Esq., P.G.S. (Read June 8th, 1898.) 



[Plate XXVIII— Map.] 



Contents. 



Page 



I. Introduction .585 



11. The Pebble-gravel 585 



III. The Goring G-ap Gravel 586 



IV. The Quartzose Gravel 587 



V. The Quartzite-graveU 590 



VI. The Relation of the Quartzite-gravel to Gravels of Local Origiri... 595 



VII. Traces of Man 598 



VIII. General Conclusions 599 



I. Introduction. 



After the appearance of Biickland's ' E-eliquiae Diluvianse/ the 

 higher gravels of this district were for a time somewhat neglected. 

 Much has now been done in the Geological Survey Memoir by 

 Mr. Whitaker, and in papers by the late Sir J. Prestwich/ Messrs. 

 H. W. Monckton,' H. J". 0. White/ A. E. Salter,* and other 

 observers to throw light upon the interesting and difficult questions 

 connected with the later physical history of this part of Eugiand. 

 It has been found convenient in the present paper to refer to these 

 gravels as a whole, but to treat more briefly those points which have 

 been already discussed. 



II. The Pebble-gravel. 



This term is used for the deposits, composed very largely of flint- 

 pebbles, which are found on the higher slopes of the Chiltern Hills, 

 resting on Lower Tertiary outliers. 



A familiar example of this gravel is that at IS'ettlebed, which has 

 been fully described by Sir J. Prestwich and Mr, White (o^j. cit.). 

 It may be seen at various places on the plateau in the neighbour- 

 hood of Cadmore End and Lane End, near High Wycombe, by 

 surface-indications ; also at Coleshill, near Amersham, at which 

 locality there is a very good section, showing about 5 feet of the 

 gravel, but at a lower level (500 feet above Ordnance-datum). 



The composition of the gravel will be seen from the following 



1 ' On the Westleton Beds, etc.,' Quart. Journ. Geol. Soc. vol. xlvi (1890) 

 pp. 84 & 120. 



2 ' On Boulders & Pebbles from the Glacial Drift,' ibid. vol. xlix (1893) 

 p. 308 ; and Proc. Geol. Assoc, vol. xii (1891) p. 108. 



^ Proc. Geol. Assoc, vol. xii (1892) p. 379, vol. xiv (1894) p. 11, and vol. xv 

 (1897) p. 157. 



* ' Pebblv Gravel from Goring Gap to the Norfolk Coast,' ibid. vol. xiv 

 (1896) pp. 389-404. 



Q. J. G. S. No. 216. 2 t 



