PARTICULARLY OF THE VALLEY OF THE GIPPING. 



433 



Pebble bed 



Adjoining the Norwich road on the right Fig. (j). 



as it leaves Ipswich, and just at the foot of 

 the sand-hills, is a large brick-pit : it is 

 worked in London-clay, which is here about 

 twenty or thirty feet in thickness, resting 

 upon Mr Prestwich's bed of black pebbles. The partial section of the main valley is therefore 

 that given by fig. (l). 



A few yards farther on, the turnpike-road passes the opening of a short hollow running 

 up to the right, along the sides of which water oozes out very plentifully, evidently at the line 

 of junction of the sand and London-clay; some works in progress for the purpose of collect- 

 ing this water afford a good section, represented by fig. (2). The upper sand is very compact, 



Drift Clay 



Fig. (2). 



London 



and of a pure red colour at the top, but very white below, unfossiliferous, and containing a 

 few angular flints. The never-failing pebble-bed is here below the London-clay, and below that 

 again is a thick mass of sand. The surface of the high ground towards the north is drift-clay. 

 Ascending the valley by following the Bramford road, we find a brickkiln some way up 

 the hill to our right, and approached by a narrow lane ; this is in the London clay, and has 

 been described by Mr Prestwich, who refers to it, as situated on the west of Whitton street. 



(?) Trace of Drift 

 Fig. (3). 



Chalk 



At the lower part of the lane are two chalk-pits, and half way up a sand-pit capped by 

 the pebble-bed, which also appears at the bottom of the clay-pit : fig. (3) gives the partial 

 sections of the main valley at this point. 



From this point, (and indeed lower, for the road followed has cut off a very prominent 

 bluff to the left), the side of the main valley which we are tracing, as also both sides of its 

 Coddenham tributary, exhibits a very marked line of sand-cliffs resting upon a lower shelf of 

 chalk ; fig. (4) shews their general contour. 



56 — 2 



