A HISTORY OF SUFFOLK 



distances of from one to three miles from the breach. It is not very probable 

 that any large number of such implements will be found, as most of them 

 will be buried too deep for agricultural operations to reach them. The few 

 that have been found, however, speak eloquently of the causes that have 

 moved them to their present positions. 



We will now pass to the gravels capping Maid's Cross Hill at 

 Lakenheath, the isolated northern extremity of the ridge. These gravels 

 are of great thickness, and their upper surface lies at about loo ft. above 

 the Ordnance datum — considerably higher, therefore, than those at Warren 

 Hill. The ovate implement is here much less predominant ; the type 

 which occurs in large numbers and which may be said to give a special 

 cachet to these gravels being a peculiar form of pointed implement with 

 a cross section approaching the triangular or rectangular shape. This class 

 of pointed implement is different from that found in the Thames Valley, 

 and so far as is known is almost special to this part of Suffolk. It is not 

 altogether confined to Lakenheath, for specimens sometimes occur from 

 other gravels in the district ; but in no other gravel with which the writer 

 is acquainted is it so distinctive a type as there. Then again, as has been 

 said before, the patina of the implements from Lakenheath is markedly 

 different from that of the implements from Warren Hill, 



Thus we see that the gravels at Warren Hill and at Lakenheath, although 

 evidently lying in the same old river-valley, and although separated from one 

 another by less than half a dozen miles, contain implements that are sharply 

 defined from one another in type and in patina, and obviously must have been 

 deposited at quite different times. Can we, then, form any idea as to whether 

 the higher gravels (Maid's Cross Hill) were deposited before or after the lower- 

 lying gravels (Warren Hill) ? For reasons too long to go into on the present 

 occasion there can be but little doubt that the higher gravels are the later. 

 This is the opposite of what obtains in the Thames Valley and in other valleys 

 of greater depth and scooped out in harder strata than those in Suffolk. In 

 these the higher gravels on the sides of the valleys are the older. But in Suf- 

 folk the valleys have filled up, and then after extensive denudation an entirely 

 different set of valleys has been produced ; the stumps of the older ones have 

 been left, as in the case of our ridge ; and the deposits show in the ordei of 

 their deposition, the higher ones being the later. This is borne out by the 

 fact that though the implements from the gravels of our ridge present so sharp 

 a contrast to those from the Thames Valley, yet gravels occur in the neigh- 

 bourhood which contain typical Thames Valley types ; and in every case with 

 which the writer is acquainted these gravels lie at a lower level than our ridge 

 gravels. The best known of these gravels is that at Shrub Hill, a few miles 

 on the other side of the Norfolk border. This gravel teems with implements 

 of Thames Valley types ; yet although it is called a 'hill,' the gravel really 

 lies on an island of gault in the middle of the fens, at a few feet only above 

 the level of the sea. The gravels which must have overlain the present 

 Warren Hill gravels to allow of the flow of water which laid down the higher- 

 lying Maid's Cross gravels, were doubtless swept away when the Lark Valley 

 was made. 



Special attention must be called to the implications arising from the 

 differences of period indicated by the differences of type and of patina in 



246 



