A HISTORY OF SUFFOLK 



Near Sudbury the Drifts are intensely contorted, and yet in places 

 they rest on seemingly undisturbed Tertiary strata, a fact explained by 

 Mr. J. E. Marr on the supposition that the naturally soft strata had been 

 frozen into a hard and unyielding condition. At the same time in 

 places the Boulder Clay contained fragments torn off the underlying for- 

 mations.' 



Contortions are often prominent where Boulder Clay rests on 

 laminated clays and sands, as to the west of Bury St. Edmunds and at 

 Halesworth Kiln. Disturbances are also met with in the Crag Series 

 at Ipswich, and in the Chalk at Botesdale, where overlain by Boulder 

 Clay. 



Some curious and possibly slipped masses of Boulder Clay have 

 been observed in the cliffs at League Hole near Corton.' In connexion 

 with these it may be interesting to mention, on the authority of the 

 late J. H. Blake, that when Sir Morton Peto made the esplanade at 

 Lowestoft he protected the cliff at Kirkley by tipping a lot of Boulder 

 Clay down the face of the cliff. 



While the Boulder Clay weathers into a brown stony loam not 

 unlike the loam of the Contorted Drift, it forms the heavier lands (the 

 ' strong loam ') of central and south-western Suffolk and of small areas 

 elsewhere. Wheat and beans and also barley flourish on the soil. The 

 district in places is well wooded, and the hedgerows are luxuriant ; in- 

 deed, the so-called ' woodlands ' of High Suffolk form a part of this 

 Boulder Clay tract. 



It is not to be regarded as a water-bearing formation, and yet it 

 includes beds of sand and gravel which here and there yield supplies of 

 water, sometimes of an artesian character. Such supplies are apt to fail 

 in seasons of drought. 



Ordinary bricks and pottery are in a few places manufactured from 

 the Boulder Clay, as near Ipswich and Burgh Castle, while elsewhere 

 sun-dried bricks are made from the clay mixed with chopped straw. 



VALLEY DEPOSITS 



Deposits of gravel and loam of later age than the Boulder Clay 

 occur under two distinct conditions. The older are high level deposits 

 connected with a system for the most part distinct from that of the 

 present drainage, but sometimes initiating it. Some of the coarse 

 gravels which overlie the Boulder Clay are of this character. There are 

 also ancient lacustrine deposits. 



Succeeding the main glaciation represented by the Boulder Clay, 

 and when, as Mr. C. Reid points out, the land stood somewhat higher 

 than at present, the streams excavated channels, as at Hoxne, ' slightly 

 below that of the present main channel of the river Waveney.' Gradual 

 subsidence turned the Hoxne channel into a shallow freshwater lake, 



• Geol. Mag. (1887), p. 262. 



' Rev. E. Hill, ^art. Journ. Geol. Soc. Hi. 302 



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