608 



MR. P. G. H. BOSWELL ON THE 



[Dec. 1913, 



channel of Drift was recorded by the Geological Survey higher up 

 the valley at JSaunton Hall. 1 The portion labelled ' Crag ' may be 

 made tip of included Crag in the Drift, such as is often met with 

 in South-Eastern Suffolk, 2 but it was the Eocene beds that were 

 the chief argument against the ' channel ' explanation. These (if 

 they are all Eocene, which is doubtful) appear to be in situ ; but it 

 is quite possible that they are not (large masses of disturbed and 

 transported Crag, London Clay, and Chalk have been recorded in the 

 Gipping Valley by Mr. Slater, in some cases preserving their natural 

 sequence). 3 That all this material may be mixed is somewhat 

 confirmed by the anomalous sequence of beds found in the most 

 recent boring at Woodbridge Waterworks (No. 1 below), although 

 it is possible that the beds have been wrongly named. It is 

 probable too, that Mr. Whitakers suggestion of slips into the 

 channel (which need not then have been at ' a goodly depth below 

 sea-level ') may be correct, especially if the channel had been eroded 

 by sub-giaeial water-streams. In any case, it appears to me that 

 the explanation of the phenomena by means of a buried channel is 

 quite as justifiable as the assumption of a trough-fault ; and, more- 

 over, such interpretation of the evidence brings this valley into 

 accordance with the others. 



Table op Borings in the Deben Valley. 



Locality. 



Height ' Thickness Chalk-surface] 



above O.D.\ of Drift \ referred to 

 in feet. 1 in feet. O.JD. in feet. 



j 





85 54* + 30 

 28 60* - 32 

 100 126* - 26 



15 52* - 37 

 13 48 - 45 



16 63 l - 47 







Do. Do. (2) 









26 61* - 35* 



Do. Sun Inn 



33 52 * - 19 



77 52 + 25 



Do. Waterworks (1) 



Do. Do. (2) 



Do. Gas-Works 



Do. Bredfield Road 



Do. Castle Brewery 



Waldringfield 



120 92 + 28 

 18 193* -175* 

 12 48" - 36 



126 155* - 29 

 20 74 a* - 54| 

 8 63 * — 55 



1 Mem. Geol. Surv. 1886 (11) p. 40. 



2 The so-called ' Crag ' is here nearly three times too thick for any known 

 section or well-boring in the Red Crag. 



3 Slater, 1907 (22) & 1911 (32). 



4 Eocene beds and Crag may also be included. 



