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
