A HISTORY OF SUFFOLK to be valleys, may, indeed, be converted into hill-tops. Though the fact that such implements are almost invariably found in gravels has been universally recognized, yet it would seem that insufficient stress has been laid upon the extraordinary nature of the floods that must have cleared the surface of the ground, over very wide areas, of all stones lying upon it at the time. For were the ground not so cleared we should find implements belonging to this period lying on or near to the surface independently of gravels. Yet this is never the case except under quite exceptional circum- stances.* It is further worthy of note that since the close of the ' Drift ' Period floods on the scale necessary for such complete sweeping of the surface seem not to have taken place ; for though the Palaeolithic Age lasted for a long time after the ' Drift ' Period had come to an end, there is no evidence of later gravels containing the implements of later palaeolithic man. Later gravels occur, it is true, but they would not seem to have resulted from so generalized a sweeping of the surface of the earth as was the case with the older gravels in which the ' drift ' implements are found. It must not be thought however that all gravels of the earlier quaternary period yield implements. This is by no means the case, not even the majority of them do so. These diluvial periods seem to have been repeated time after time. Sometimes man had existed in the district and had made his weapons since the last diluvial period, and these weapons appear in the gravels resulting from the next ensuing floods. Sometimes man had been absent in the interval between two such periods, and no implements lay on the ground to be incorporated in the gravels. But that these diluvial periods recurred many times, and that marl disappeared from the scene and reappeared many times during the long series of centuries involved, is clear from the occur- rence in a comparatively small area of country of gravels at different levels, some of them with implements, some without a trace of them ; whilst of those with implements there are, in gravels in near proximity to one another, wide diffisrences of type and of patination,* such as would be impossible if the gravels had been laid down at the same time, and if the floods giving rise to them had swept the surface of implements made by the same race of man and belonging to the same period. This is very clearly seen in North-west Suffolk and the adjacent parts of Norfolk, where a large number of implementiferous gravels have been discovered. It would require more space than can be here allotted, and more knowledge than is perhaps at the disposal of anyone at present, to deal with all these gravels in a scientific way. It is proposed therefore to consider certain gravels which occupy what is now a ridge, running for several miles from south to north from a point about 2 miles east of the little town of Mildenhall, to a point about three-quarters of a mile east of the village of Lakenheath. This ridge is a mere fragment ' There are two conditions under which this may occur : (l) Where palaeolithic man was living on a ridge, as on the present North and South Downs of southern England. Here the physical conditions are such as to prevent the gathering force of any large body of water. On these Downs ' drift ' implements are not unfrequently found on the surface, (z) Where an old implementiferous gravel has been cut through by a river of later date, and its contents scattered over the lower course of the river ; in this case ' drift ' imple- ments may be found in the alluvial soil of the newer river. Occasionally also ' drift ' implements were buried to a considerable depth in brick-earth or other deposits, apd thus protected from later changes. ' The word ' patination ' is used to indicate the changes of surface of hard materials such as stone or bronze resulting from age. 236
