LATER TERTIARY GEOLOGY OE EAST ANGLTA. 107 



ft. 



Upper Glacial clay (5 



Coarse gravel 3 



Middle Fine gravel, containing shell-fragments and 1 „ 



Glacial) gradually changing into J 



(Buff sand 45 



Red Crag with shells 6 



Red Crag in water 4 



Total 67 



There was nothing in this deep section answering to the sands 

 described in the first part of this paper as altered Crag, the coarse 

 saccharoid buff-coloured Middle Glacial sand (in the upper part 

 of which occurred the gravel with shell-fragments) being uniform in 

 character throughout its whole thickness, and resting directly on 

 shelly crag. This altered crag occurs, however, in a pit at Seckford 

 Hall, in a small valley about two furlongs from the Well-section. 



In the before-meutioned " Introduction " we spoke of a brick- 

 earth at Stowmarket, in the valley of the Gipping, as Postglacial ; 

 but Mr. Whitaker informed us that this had been by further exca- 

 vation exposed as passing under the Upper Glacial clay*. Some 

 other exposures of the same deposit occur also in the neighbourhood 

 of the Gipping valley (which is the continuation of that of the Orwell), 

 while on the wide tableland which divides this valley from that of a 

 rivulet flowing into the Little Ouse, a protrusion of the same deposit 

 occurs (as we are informed by Mr. Whitaker) at Woolpit, five miles 

 north-west of Stowmarket. When, some years ago, we examined the 

 many pits at Woolpit, we found one showing the brick-earth over- 

 lying the Upper Glacial, and none showing it beneath that formation ; 

 but we are told that some later excavations do show this, and that 

 therefore brick-earths of two distinct ages, one above and one beneath 

 the Upper Glacial, occur there. These various exposures appear to us 

 to indicate that part of West Suffolk is, like the centre and east of the 

 county, occupied by the Contorted Drift, overspread and concealed 

 by the Upper Glacial, with the Middle Glacial similarly distributed 



* From an account of the well sunk at the Stowmarket brewery, given by 

 the late Rev. Professor Henslow on a tablet in the Ipswich Museum, the brick - 

 eartb of this brick-field appears to underlie the town, and to possess a thickness 

 equal to that at Kesgrave and Woodbridge. Finding the Middle Glacial in 

 section at the brick-field at a lower level than the section of the brick-earth, we 

 were originally led to regard the latter as over the former, and consequently as 

 Postglacial; but a late visit by one of us to the spot disclosed that the facts are 

 really entirely in harmony with the general features of valley-structure which 

 are discussed in the text, the Middle Glacial, which we had supposed to pass 

 under the brick-earth, only lying against it as a deposit of the interglacial 

 valley cut out of that brick-earth. On the opposite side of the river Gipping 

 the valley-sides are all formed apparently by the Middle and Upper Glacial 

 only, which are in section in the railway-cutting near the Station. The other 

 exposures referred to as occurring in the Gipping valley, are one at Codden- 

 ham Old Hall (where the Contorted Drift is overlain by the Upper Glacial), 

 and the other by Hawk's Mill, on the north side of Needham Market. This 

 last exposure seems to extend up the lateral valley which runs between the two 

 Creetings. In both sections the brick-earth forming this Drift was contorted 

 when we visited them several years ago. 



