PARTICULARLY OF THE VALLEY OF THE GIPPING. 443 



At Aspal two wells, whose position relative to the stream I do not know, give 90 and 

 45 feet respectively of drift-clay resting upon a red sand. At Debenham and Winston are 

 brickkilns a short way up the flanks in reconstructed stratified drift-clay lying upon a basis 

 of drift-clay. At Framsden and Cretingham, an equal height up are sand-pits, which 

 probably rest upon drift-clay, as this is seen below them. (There seems a possibility of the 

 sand, though distinctly stratified, being in some places within the drift-clay.) The lower 

 level of the valley from this point downwards is entirely sand and gravel, as an inspection 

 of the Ordnance map will shew : the higher lands however are drift-clay ; and much doubt 

 may be entertained whether this sand is merely a manifestation of that which all the above- 

 quoted sections prove to exist below the drift-clay, or whether it is the result of a much 

 later estuary action within the valley itself. 



In the valleys of the Ore and Aide it shews itself in the same way, and at Benhall 

 pottery I have seen it come out most unmistakeably from under the drift-clay itself. The 

 drift-clay is very thin and almost disappears, except on high ground, everywhere to the S. E. 

 of a line passing from Ipswich through Woodbridge, Sawmundham, to Dunwich : so thin 

 is it along this line that farmers are in the habit of draining their high lands by " tapping," 

 i. e. by making a perforation through the clay at some convenient spot, which serves as a 

 conduct pipe to carry away any amount of water. 



It is remarkable that this supposed line is very nearly the N. W. boundary of the crag- 

 deposit ; some fossiliferous clays, as those of Chillesford and the neighbourhood of Tunstall 

 and Iken (investigated by Mr Prestwich), overlay portions of the crag; but the whole district 

 is generally covered with a sand which is most probably a part of that just alluded to as 

 underlying the drift-clay, left behind in the denudation of the latter, and going far by its 

 own reconstruction to produce the sand-deposits in the present river-valleys. 



We are not without evidence of considerable disturbances posterior to the crag. A section 

 of the coast from Harwich to the mouth of the Deben given by Mr Clarke exhibits dislo- 

 cations of the strata of the crag and London clay. 



The strata of the chalk are not in all cases readily made out, but in many places they 

 are distinct enough to shew that the present valleys are due to elevation and fracture. 

 At Offton where the valley runs N. W. to S. E. a chalk-pit on the N. E. side shews 

 the strata rising to the S.W. At Blakenham, lower down the same stream, they rise to the S. 

 At Shelly on the west side of the valley they rise to the N. E. At Bramford the beds of 

 the London clay on the chalk dip to the S. E., probably indicating a dip of the chalk in the 

 same direction ; these pits are on the east side of the valley. 



It may not be out of place at this point to remark, that a somewhat hasty glance at the 

 coast sections of Norfolk (from Wells to Happisburgh) has led me to believe that the drift- 

 clay there exhibited differs greatly in character from that of Suffolk : it is generally a pretty 

 nearly homogeneous clay with small chalk "nibs" plentifully sprinkled through it, and has 

 a certain rough species of stratification about it; the multitudes of secondary boulders, or 

 rock fragments, which characterise the Suffolk clay, are almost entirely wanting in it. This 

 Norfolk clay is also thickly covered by very irregular masses of sand and gravel, of which 

 I have seen no distinct evidence in Suffolk excepting on the north side of Lowestoft ; 



