C— GEOLOGY 79 



Miss M. Tomlinson's excellent work on the similar deposits of the river 

 Avon and its tributary, the Stour, enables us to continue the story over 

 the Moreton watershed into the Evenlode Valley, where Dr. K. S. Sand- 

 ford has picked up the threads. The Drifts of the Avon-Stour region 

 consist of high-level gravelly deposits mostly containing boulders foreign 

 to the district. These Drifts antedate the fluviatile deposits, which 

 Miss Tomlinson has classified as Terraces No. 4, No. 3 and No. 2, in 

 order of decreasing age. The earliest Drift consists of Plateau Gravels, 

 and the latest, termed the Moreton Drift, is a chalky deposit which in 

 places has the character of a boulder clay derived from the north. The 

 Moreton Drift, which Miss Tomlinson would correlate with the Chalky 

 Boulder Clay of the country farther east, penetrates the pre-existing 

 Moreton gap into the Evenlode drainage, and, on considerations of 

 gradient, seems to be connected with the Wolvercote Terrace-gravels 

 of the Oxford district. Terraces Nos. 3 and 4 of the Stour-Avon drainage 

 mark an aggradation accompanied by a ' warm ' fauna (including Corbi- 

 ciila fluminalis, Hippopotamus, and Elephas antiquus). It is to be noted 

 that Corbicula fluminalis here appears at about the same horizon as in 

 the east of England. Terrace No. 2 carries a cold fauna (including 

 mammoth and woolly rhinoceros), and, in the opinion of Dr. Wills, is 

 to be correlated with his ' Main Terrace ' of the river Severn, and there- 

 fore with the maximum glaciation of the Irish Sea area. Unfortunately, 

 no implements that might assist in correlation have been found. 



The Upper Thames. 



To Dr. K. S. Sandford's valuable work we owe our detailed know- 

 ledge of the sequence of events in the region of the Upper Thames, where 

 the problems are of exceptional difficulty. Dr. Sandford has recently 

 (1932) correlated the Plateau Drift (containing Scandinavian erratics) with 

 the Scandinavian Drift (Norwich Brickearth) of Eastern England, and 

 the later-formed 100-140 ft. Terrace of the river Thames containing 

 Chellian implements, with the overlying sands and gravels of East Anglia. 



The Chalky-Jurassic Boulder Clay of the east of England does not 

 reach the Oxford district, but the early retreat-stages of the ice may 

 be represented by the formation of the Wolvercote Terrace. Next 

 follow the Lower and Upper Summertown-Radley Terraces, with cold 

 and warm faunas, respectively, which Dr. Sandford would now correlate 

 with the lower brickearths at Hoxne. Thus the succeeding Lower 

 Gravels of the Wolvercote Channel with their warm fauna and late 

 Acheulian and Micoque implements would be the equivalent of the 

 corresponding (Upper Acheulian) gravels of Hoxne and other East Anglian 

 localities. Corbicula fluminalis appears in the Upper Summertown- 

 Radley Terrace in association with the straight-tusked elephant and 

 hippopotamus — that is, at just about the horizon at which we have by 

 now been led to expect it. The upper beds of the Wolvercote Channel, 

 of cold-temperate character, with their single Mousterian implement, 

 are correlated with the Mousterian brickearths farther east, and the 

 warp at the top of the channel with the Upper Chalky Drift, for it yields 

 evidence of probable frozen-soil conditions. The latest deposits of the 



