C— GEOLOGY 8i 



a recent and most useful review of the problem has led Dr. Sandford 

 to general conclusions similar to those at which I had independently 

 arrived. Dr. Sandford now correlates the 100-140 ft. terrace with 

 the Caversham and Dartford Heath Chellian gravels, and his Wolvercote 

 Terrace with the Chalky-Jurassic Boulder Clay. Further, he equates 

 the Lower Summertown-Radley Terrace with the Swanscombe Clac- 

 tonian-Acheulian gravels of the loo-ft. terrace, and the lower beds of the 

 Wolvercote Channel with the 50-ft. or Taplow Terrace. The upper beds 

 of the Channel are thus correlated with the Lower Crayford Brickearth 

 (Early Mousterian). The oldest ' warp ' of the Oxford district would then 

 appear to be comparable with the Coombe Rock (Upper Mousterian). 



At Clacton, on the Essex Coast, Mr. Hazzledine Warren has discovered 

 a river-channel of which the lower beds contain Clactonian flakes 

 associated with elephant and other mammalian remains, and plants, 

 indicative of warm conditions. Derived specimens of Corbicula fluminalis 

 are also found. Correspondence is here suggested with the loo-ft. 

 terrace of the Thames, although the deposit lies at only 43 to 48 feet 

 above O.D. A few miles farther north, at a level of 74 feet above O.D., 

 lie the gravels of the river Stour ; also, the Stutton low terrace with 

 Corbicula fliiminaUs, already mentioned. Thus the Stour deposits, 

 which on field evidence appear to be more recent than the Chalky- 

 Jurassic Boulder Clay, are probably to be correlated on the one hand 

 with the Clacton gravel and loo-ft. terrace of the Thames, and on the 

 other with the Acheulian deposits of Ipswich, Hoxne and Whitlingham, 

 referred to earlier in this address. 



The Midland Area. 

 We have now closed our traverse, but we shall hardly be able to avoid 

 the feeling that there are weak links in our chain of evidence, especially 

 concerning the south-western part of the Midlands and the borders of 

 the Irish Sea, where the difficulties are greatest and the traces of Early 

 Man scanty or absent. It remains to see whether any cross-ties of 

 evidence, which will serve as checks on our correlations, can be obtained 

 by way of the central and northern Midlands. Unfortunately, dis- 

 coveries of the implements of Palasolithic Man are rare and sporadic 

 in the counties of Leicestershire, Nottinghamshire and Lincolnshire. 

 A few cave-deposits, like those of Cresswell Crags, have yielded a rich 

 harvest of implements and confirmed the time-succession of Palzeolithic 

 industries, but the beds containing them are unfortunately not in contact 

 with glacial deposits. The irregular driftless areas of Lincolnshire, 

 Nottinghamshire, Derbyshire and Staffordshire suggest considerable 

 denudation in late-glacial times rather than non-deposition of glacial 

 detritus. In many parts of the area the officers of the Geological Survey 

 have been unable to distinguish with certainty more than one boulder 

 clay with associated sands and gravels, although Mr. R. M. Deeley long 

 ago claimed to be able to distinguish three or even four in the Trent 

 basin, separated by interglacial sands and gravels. Much excavation 

 took place in the valley of the Trent after Chalky Boulder Clay times, 

 and the oldest Trent gravel is more recent than the glacial deposits ; 



