8o SECTIONAL ADDRESSES 



Oxford district are then correlatable with the various post-Mousterian stages 

 of East AngHa, as shown in the table accompanying this address. The 

 Oxford succession can thus be fitted in fairly satisfactorily with our standard 

 succession on the one hand and the Stour-Avon succession on the other. 



The Lower Thames. 



The terraces of the Lower Thames have been the subject of numerous 

 papers. Thanks to the efforts of Messrs. Chandler, Leach, Reginald 

 Smith, the officers of the Geological Survey (particularly Mr. H. Dewey 

 and Mr. H. G. Dines), and other workers, our knowledge of the succession 

 is now well founded, and I need only summarise the results of their 

 labours. The river-deposits seem to be later than the Chalky-Jurassic 

 Boulder Clay. The loo-ft. terrace marks a period of aggradation, and 

 is divisible into three beds of sandy gravel separated from one another 

 in certain cases by deposits of marly loam. In the lowest gravel are 

 large cores and flakes of the Clactonian industry, associated with Elephas 

 atitiquus and Rhinoceros leptorhimis. The upper portion of this bed and 

 the base of the succeeding loam contain land and fresh-water moUusca, 

 including Corbicula fluminalis and Theodoxus cantianus. The middle 

 gravel contains unabraded Early Acheulian hand-axes, and in its upper 

 part, twisted ovates (Late Acheulian). In a brickearth of rather later 

 age have been found Late Acheulian and Early Levalloisian ovate imple- 

 ments. The 50-ft. terrace contains rolled Acheulian implements and 

 affords evidence of corrasion during the warm period when its lower 

 beds were formed, and aggradation during the colder times when its 

 upper beds were laid down. The Levalloisian tortoise-core industry 

 appears approximately at the level of this terrace. The Crayford brick- 

 earth, which succeeds it, contains at its base Levalloisian flakes ; also, 

 the cold fauna found at this time of aggradation foreshadows the oncoming 

 of the arctic conditions which gave rise to the Coombe deposits, which may 

 be correlated with the Upper Chalky Drift. The Coombe deposits here, 

 as Dewey figuratively says, ' put an end to Levallois Man.' At Bapchild, 

 in the Medway Valley, Mr. H. G. Dines found in the Coombe deposit 

 Early Levalloisian implements in a battered and scratched state. These 

 had probably been transported for a short distance. Late Levalloisian 

 implements were found at the base of a brickearth which overlies the 

 Coombe deposits, and Aurignacian (or even later) implements above 

 them. The evidence of the Whitehall and Lea Valley deposits indicates 

 uplift, erosion and aggradation under cold conditions, the ' Ponders 

 End stage ' of Mr. Hazzledine Warren. The age of these deposits has 

 not been established with certainty, but the flakes found in them have 

 been doubtfully regarded as Aurignacian ; they are, in any case, pre- 

 Neolithic. In company with other investigators, I am much tempted 

 to correlate the Ponders End stage with the post- Aurignacian Hunstanton 

 and Hessle Boulder Clays, for the cold conditions which brought boulder 

 clay so far south as the Wash must have had a marked influence on the 

 fauna and flora of the Thames Valley. 



The correlation of the deposits and industries of the Upper Thames 

 and Lower Thames has not been effected without some difficulty, but 



