C— GEOLOGY 71 



adopt Dr. Solomon's designation for them of Upper Chalky Drift (his 

 Little Eastern glaciation). 



In the present state of our knowledge we cannot consider the Upper 

 Chalky Drift in East Anglia to be due to a major glaciation of the same 

 intensity as those that produced the Norwich Brickearth and the Great 

 Chalky Boulder Clay, respectively, for the following reasons. Deposits 

 of this age are not widespread, or at least have not yet been identified 

 (possibly because of the absence of human industries) at more than a 

 few localities. They occur more frequently in the valleys, but here 

 again the evidence is conflicting, for on both the slopes and bottoms of 

 the valleys Mousterian Man left ' floors ' containing Combe Capelle 

 and Levallois types, as discovered near Ipswich by Miss Layard and 

 Mr. Reid Moir. Probably all these industries, however, are referable 

 to Early Mousterian, whereas the glaciation was apparently Middle to 

 Late Mousterian. 



To revert for a few moments to the pre-Upper-Chalky-Drift interval, 

 let us consider the conditions that obtained in the river-valleys while 

 the lake-areas were being silted up. The valleys had been partly infilled 

 with Chalky Boulder Clay and its associated sands and gravels. The 

 melting and retreat of the ice not only produced in the plateau-country 

 spreads of glacieluvial gravel containing Chalky and Jurassic debris, 

 but must have resulted in floods descending the valleys. A period, 

 first of erosion and later of aggradation, appears to have set in, and the 

 river-terraces situated at from 50 feet (River Yare) to 70-80 feet (River 

 Stour) above present river-level were formed. The streams were doubt- 

 less braided, and, as they wandered to and fro in the valleys, formed 

 gravel-flats of which the range from bank to bank extended from one to 

 three miles. The terrace-materials are frequently indistinguishable 

 from glacial gravels, and had undoubtedly the same origin. But in 

 them rolled Chellian and Early Acheulian implements, especially hand- 

 axes, are occasionally found. In particular, at Whitlingham, in the valley 

 of the Yare near Norwich, Messrs. J. E. Sainty and H. H. Halls made 

 a wonderful collection of nearly 300 implements, of which a few were 

 rolled and striated Chellian types, but the majority unrolled and probably 

 of Late Acheulian age. The absence of evidence of a land-surface and 

 of peaty bands suggests that Acheulian Man was following the retreating 

 ice-sheet, possibly at no great distance from it, and was temporarily 

 encamping on gravel-banks adjoining the streams. Although negative 

 evidence is never entirely satisfac ory, we may recall that no beds of 

 peat or planty layers have been recorded in the lake-like areas of brick- 

 earth that occupy hollows in the Chalky Boulder Clay of Norfolk ; it is 

 conceivable that, being nearer the ice-margin, the area was subjected 

 to more rigorous conditions and more scour from melt-waters than the 

 country farther south. 



At another interesting locality, Dovercourt, near Harwich, the ancient 

 gravels of the river Stour lying at about 74 ft. above the river-level 

 yielded to W. C. Underwood a series of implements and bones. The 

 implements included rare Chellian types and a large collection of Early 

 and Late Acheulian axes, unrolled and unscratched. The mammalian 



