Vol. 69.] THE AGE OF THE SUFFOLK VALLEYS. 581 



J26. On the Age of the Suffolk Valleys ; with Notes on the 

 Buried Channels of Drift. By Percy George Hamnall 

 Boswell, A.K.C.S., B.Sc, F.G.S. (Read May 28th, 1913.) 



[Plates LIV & LV— Maps.] 



Contents. 



Page 



I. Introduction 581 



II. The Earlier Limit of Age 585 



III. Position of the Upper (Chalky) Boulder Clay . 587 



IV. Evidence of Age adduced from Glacial Dis- 



turbance in the Valleys 589 



V. Evidence of Age from Well-Borings, etc 597 



VI. Theoretical Questions and General Kemarks.., 611 



VII. Conclusions 616 



VIII. Bibliography 617 



I. Introduction. 



The main watershed of Suffolk follows generally the Chalk outcrop, 

 but keeps rather to the east of it, running in a north-easterly direc- 

 tion from Haverhill, in the south-west of the county, to Diss, on 

 the borders of Suffolk and Norfolk, where it turns north, or a little 

 west of north, until it finishes at the Cromer ridge. It thus runs 

 'roughly parallel to the Chalk escarpment, changing in direction 

 with it. This more easterly run of the watershed appears to be 

 •due to the covering of Glacial Drift upon the Chalk. The valley- 

 system of Suffolk is, in consequence of this change of strike of the 

 'Chalk and change of direction of the main watershed, of a palmate 

 or radiating form, the rivers which have carved the chief valleys, 

 "taken from north to south, being: — (1) The AVaveney, flowing east- 

 north-eastwards and entering the North Sea at Yarmouth ; (2) the 

 Aide, flowing generally east-south-eastwards to Aldeburgh, but only 

 reaching the sea at Orford ; (3) the Deben, flowing south-east- 

 wards to the coast at Bawdsey ; (4) the Gipping (with its estuary, 

 the Orwell), also flowing south-eastwards ; (5) the Brett, flowing 

 southwards into the Stour estuary ; and (6) the Upper Stour (as 

 distinct from the Stour estuary), flowing southwards into the wide 

 east-and-west estuary of the same name. 



The Little Ouse, rising close against the source of the Waveney 

 at Lopham Ford (where a small low bank of gravel forms the 

 only present watershed), flows westwards, and forms part of the 

 northern county boundary. At Thetford it receives a small 

 tributary flowing from the south-east through Ixworth and Euston. 

 The Lark, on which stands Bury St. Edmund's, is the only other 



Q. J. G. S. No. 276. 2 q 



