498 ME. F. W. HARMEK ON THE [Nov. 1907, 



At Moreton-iii-the-Marsh, on the Stour-Evenlode watershed, 

 more than 400 feet above sea-level, there are some exposures of 

 coarse gravel resembling in their general character the ' Cannon- 

 shot ' deposits of East Anglia, composed mainly of Bunter pebbles, 

 but containing also large blocks of grey flint of Lincolnshire type, 

 and of Carboniferous sandstone. 



From the Moreton plateau the Triassic Drift, following the 

 Evenlode into the Oxford plain, crosses the latter towards the 

 Goring gorge at a maximum elevation of about 450 or 500 feet, 

 representing, however, not so much the level of the lowest part of 

 the plain at the period in question, I think, as the height at which 

 an overflow took place over the Corallian ridge just mentioned ; this 

 point, however, will be discussed later on. 



It seems probable that the level of the Oxford plain has been 

 reduced since the Glacial Period ; on that view the lower part of 

 the valleys of the Evenlode, Cherwell, 1 and other rivers draining 

 into it have been cut down in comparatively recent times to a 

 corresponding degree. 2 The Bunter Drift occurs, not so much at 

 the bottom of the Evenlode valley, as along its flanks ; near 

 Leafield, indeed, where the river turns suddenly eastwards, the 

 Drift overrides the high land, taking a more direct course towards 

 Oxford, as shown in Buckland's map, and afterwards by the late 

 W. C. Lucy. 3 



The distribution of the Bunter Drift thus sketched out, following 

 as it does a clearly-defined trail, could not have taken place 

 under conditions similar to those which now obtain. Its volume is 

 too great and the area over which it may be traced too wide and 

 continuous, I think, to justify the theory that it was due to a 

 hypothetical river, descending at a remote period from the 

 Pennines. 4 



If the distribution of the Triassic pebbles and the excavation 

 of the Goring gorge had been due to such a primeval river, crossing 

 the Oxford plain transversely from the Jurassic escarpment to that 

 of the Chilterns (at an elevation in the first place of nearly 500 feet 

 above sea-level), such conditions must have been continuous to 

 the present day. The co-existence at no great distance, however, 

 of the strike-valley described on p. 495, 200 to 400 feet below it, 

 seems inconsistent with such a view. The low-level strike river, 

 cutting itself back through the soft Oxford Clay until it was joined 



1 The whole course of the Cherwell Eiver below Banbury lies under the 

 300-foot contour. 



2 It is worthy of notice, I think, as bearing on this point, that the later 

 gravels of the Oxford plain, those occurring at a comparatively low level, 

 contain a predominant amount of Jurassic material. 



3 ' The Gravels of the Severn, Avon, & Evenlode, &c.' Proc. Cottesw. Nat. 

 Field-Club, vol. v (1869-72) p. 71. Mr. E. H. Eastall and I spent some time 

 in visiting the localities described by Lucy, and can testify to the accuracy of 

 his observations. 



4 This view is adopted, however, by Mr. S. S. Buckman, in a well-known 

 paper in ' Natural Science ' vol. xiv (1899) p. 288. 



