88 SECTIONAL ADDRESSES 



joined by the Lake District ice and swept over Stainmore into the Tees 

 Valley and also down the Tyne Valley. It also appeared to have filled 

 the Irish Sea and to have advanced on to the Welsh Coast and across the 

 Cheshire Plain to the Shropshire hills. 



The evidence for the Third Interglacial phase is not at present strati- 

 graphically clear. By inference, the ice must have retreated on a large 

 scale, for Aurignacian Man was able to establish himself on many sites 

 and to reach the caves of Derbyshire and North Wales, and to leave, in 

 the former case, examples of his art tnobilier. He was accompanied by 

 a fauna of arctic and tundra type. The situation of his ' floors,' at present 

 below sea-level at some localities, indicates that the land-area stood 

 higher than now, so that communication with France and Spain must 

 have been relatively easy. 



Corresponding with the evidence of a decrease of temperature in the 

 Spanish and French cave-deposits, where the warm Aurignacian is 

 followed by indications of a colder climate in the Magdalenian, is the 

 development in northern England of great ice-sheets, the easternmost of 

 which produced the Hessle Boulder Clay and was able to advance as far 

 southwards as Hunstanton. Here its force was expended, and although 

 it was able to pick up and include Middle Aurignacian implements on 

 its way, it did not exercise sufficient influence to prevent Late Aurignacian 

 and Magdalenian Man from living at no great distance from its front, 

 as, for example, in East Anglia, and beyond the York Moraine in the 

 Cresswell Caves. In the west of England and in Wales the Lake District 

 and Scottish ice, having again filled the Irish Sea, invaded the marginal 

 portions of the Cheshire Plain and North Wales. Aurignacian Man was 

 driven from the country and the remains of his activities were sealed 

 up in the North Welsh caves. We have considerable evidence of the 

 retreat-stages of this Fourth Glacial Episode, and are at present led to 

 believe that no subsequent glaciation of equal importance followed. 

 While it may be true that the re-advance of the Scottish ice into the 

 Lake District area marks a fifth glaciation, in the east and south of England 

 Man appears to have survived free from climatic interruptions on a 

 land-surface not very different topographically from that of to-day. 



The passing of the Ice Age was marked by a slow but steady sub- 

 sidence of the land-area of southern and eastern England, which com- 

 menced apparently after Late Aurignacian times, and continued until 

 after the Neolithic period. Thus were produced the submerged forests, 

 the drowned river-valleys and the buried valleys which occur just below 

 the present-day flood-plain deposits of the rivers. 



And so the final touches on our picture portray a land very similar to our 

 country as seen by modern Man. Thenceforward its features become the 

 study of the geographers, and its vicissitudes the concern of the historians. 

 As geologists we piece together the earth's story, one of unending yet varied 

 change, from the rocky remnants on which we live. But, as we receive 

 our earth from the astronomers, a world chronologically remote in its 

 early stages and void of life if not of form, so we must in our turn pass 

 it on to the historians. For the close of Palaeolithic times marks the end 

 of our course, and, like the runners of old, we hand on the torch of life. 



