Vol. 69.] 



THE AGE OF THE SUFFOLK VALLErS. 



601 



classes doubtfully as ' ? all Reading Beds.' Neither the thickness 

 nor the levels support this possibility : the beds seem to be very 

 much mixed, and are probably reassorted material in Drift. The top 

 ot the Chalk is thus below O.D. A general consideration of 

 all the borings in the county and the drawing of approximate 

 contour-lines would lead to the conclusion that, even allowing 

 for local dips, Chalk should crop out in this valley with its 

 surface at about +80 feet O.D. at Hadleigh. Recent borings at 

 Hadleigh, near the river-level, show 72 and 79 feet of Drift. The 

 subjoined table gives details of the borings in the Brett Valley and 

 establishes the presence of one or more buried channels (see fig. 2, 

 p. 600). 



Table of Borings in the Brett Valley. 



Position. 



Height i Thickness 

 above O.D.] of Drift 

 in feet. in feet. 



Chalk- surface 

 referred to 

 O.D. in feet. 





270 150 

 280 312 

 175 104+ 

 300 250 

 118 — 

 120-130 ' — 

 200 60 

 100 ' ; n 



+120 



- 32 

 below +70 



+ 50 

 + 118 

 + 120 

 + 140 

 4 80 

 + 90 



+ m 

 + 

 - 20 



- 42 



- 2 

 + 









Bildeston * 



Chelsworth and Monk's Eleigb. 



Whatfield 





Kersey 



Coslord 



Hadleigh— Woods & Co 



Do. Wilson's Malting 



Do. by the river 



Do. 1909, Deanery 



Do. 1911 



90-100 

 126 

 90 

 80 

 60 

 70 

 80 



95^ 

 90" 



100 



102 



72 

 80 



(c)Gipping Valley. — The existence of a similar channel in 

 the Gipping Valley, just at the head of the Orwell Estuary, was 

 noted as far back as 1885, 1 in the boring at St. Peter's Quay. 

 Subsequent borings have confirmed this earlier record. The chief 

 of twenty wells and over seventy trial-borings are shown upon the 

 sketch-map (fig. 4, p. 602), and it is probable that if a town of the 

 size of Ipswich had been situated in any of the other valleys of 

 Suffolk, we should have had just as much more definite information 

 as to the extent of the channel in that valley. Beginning at the 

 upper end of the valley, in the neighbourhood of Stowmarket, there 

 seems to be good evidence for a channel. The Chalk by protraction 

 should here be reached at about 120 feet O.D. It crops out 2 miles 



Geol. Surv. 1885 (10) p. 118. 



