586 MK. P. G. ff. BOSWBLL ON THE [Dec. 1913, 



Woodbridge and Aldeburgh, S. Y. "Wood, Jun.'s determination was 

 adopted. 1 The fact that the loams were much contorted may have 

 lent colour to this view, but investigation of the section and careful 

 mapping of the area show that these loams are underlain by the 

 sand and gravel series. At the famous Hasketon section (the 

 brickyard a mile north-west of Woodbridge) there is a bed of blue 

 laminated loam, sometimes contorted, overlain by Upper Boulder 

 Clay (Chalky-Kimeridgic), with a continuous passage up in one part 

 of the brickfield. The colour of this blue loam is apparently a direct 

 result of its being wash-out material from the Boulder Clay, which 

 has a deep bluish Kimeridgic matrix. A digging in the floor of 

 the pit reached Glacial sand, which is also met in wells near by, and 

 crops out at its normal lower level in the plantation and sides of the 

 little valley on the west. Between the blue loam and the sand is 

 a bed of reddish and buff-coloured loam with an irregular upper 

 surface. At Blaxhall, near Aldeburgh, are several pits (one figured 

 in the Memoir quoted 2 ), which show sands, loams, and chalky 

 material very much mixed up. The consideration of these disturb- 

 ances follows in a later section of this paper; but it is clear, in this 

 case, that the loams are merely derived from the Upper Boulder 

 Clay, and in places are seen passing into it, and also into the silty 

 and chalky sands so common at this locality. One other exposure 

 calls for comment: namely, Derby Boad Brickfield, west of Ipswich, 

 almost on the edge of the Gipping Valley. Here it was recently 

 proved by digging that the brickearth was actually resting on the 

 Upper Boulder Clay, the whole lying in a lake-like basin in the 

 Glacial Sands and Gravel. In this case, again, the loam is in places 

 contorted and disturbed ; but, far from being Contorted Drift, it is 

 of post-Glacial age containing a Palaeolithic floor. 



It has been suggested that some of the loam and Boulder Clay 

 of the remarkable Sudbury sections is of Lower Glacial age, and 

 equivalent to the Norfolk type. The Rev. E. Hill, after a careful 

 study of the deposits, cannot accept this view. 3 No igneous erratics, 

 like those that are so very characteristic of the Contorted Drift, 

 have yet been found in it; nor is it, in my opinion, similar in 

 appearance to the last-named deposit. 



It is pretty well established, then, that the radiating valleys 

 here dealt with (other than the border river, the Waveney) cannot 

 cut through the Lower Boulder Clay : since, if it ever existed over 

 Mid- and South Suffolk (of which there is no direct or indirect 

 evidence), it must have been denuded off before the advent of 

 the Glacial Sands and Gravels and the Upper Boulder Clay. The 

 valleys are thus later in age than the Bed, Norwich, or Chillesford 

 Crag, according to which occurs. By analogy, however, with the 

 Waveney and the Norfolk rivers (particularly the Wensum and 

 the Tare), which Mr. F. W. Harmer has considered in detail, 4 the 



' » Mem. Geol. Surv. 1886 (11) pp. 28, 29, & 30. 



2 Ibid. p. 29. 



3 E. Hill, 1912 (34) p. 28. 



4 Harmer, 1910 (29) p. 130. 



