492 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 2, 



second elephantine period, intervening between the elevation of the 

 erratic tertiaries, and the distribution of the Warp-Drift over their 

 denuded surfaces *. 



Northern Drift. — This is the most ancient pleistocene formation 

 of the district, and attains an elevation of between 600 and 700 feet 

 above the level of the sea on the oolitic hills south of the Vale of 

 Moreton. Deposits belonging to the Northern Drift Series at 

 Mickleton Hill, and Aston Magna have already been described by 

 Mr. G. E. Gavey before the Society f ; and the height which they 

 attain at Mickleton Hill is 490 feet ; and, as I am informed by Mr. 

 Howell, of the Geological Survey, that he found no erratic pebbles 

 on the high oolitic ground to the N.E. and S.W. of the less elevated 

 ridge through which the Oxford Railway passes, it would appear, as 

 Mr. Gavey observes, that '* the gravel, sand, and clay (of Mickleton 

 Hill) formed the bed of a channel communicating between Moreton 

 and Evesham Valleys, and having Dovers and Campden Hills on the 

 west, and Ebrington Hill to the east." 



At Adlestrop there is another section in Northern Drift, 1 2 feet 

 deep. It consists of alternating beds of coarse red sand, clay, and 

 gravel composed of the following kinds of rock : — 



Yellow chalk-flints, in great abundance. 

 Rounded white and coloured quartz. 

 Large pieces of gritty sandstone. 

 Fragments of slate. 



At Oddington there are several pits in coarse siliceous red sand and 

 gravel, containing similar fragments of rock. The sand is occasionally 

 blackened by coal-smut. 



A bed of gravel 12 feet deep, similar to the last, occurs above 

 Langley Mill near Ascott, at an elevation of about 80 feet above 

 the Mammaliferous deposits which occupy the valley of the Even- 

 lode, and which I have attempted to describe as being of later date. 

 In this and the other gravels I searched carefully for shells, but with- 

 out success. 



The sands of the Northern Drift are always coarser than those of 

 the estuarine period ; and the absence of granitic fragments, so 

 abundant in the gravels of Salop, Worcester, and Staffordshire, is 

 worthy of remark. Mr. Howell informs me that he has never met 

 with any in the Valley of Moreton. I therefore consider that almost 

 all the Northern Drift of this part of the country has been derived 

 from the debris of the rocks of the Midland counties. The sands 

 have been apparently derived from the waste of the New red sand- 

 stone ; the quartzose pebbles are identical in appearance with those 

 which form the conglomerates of that formation ; the grits and 

 pieces of chert are doubtless from the Carboniferous rocks ; and the 

 fragments of slate may have been derived from the Atherstone and 

 Charnwood Forest rocks. While the oceanic current was spreading 

 the debris of Cumberland and the border-counties of Scotland over 



* Quart. Journ. Geol. Soc. vol. ix. p. 295 ; and vol. x. p. 244. 

 t Ibid. vol. ix. p. 29. 



