650 STKATIGRAPHICAL GEOLOGY 



Europe in an oblique direction to the northern shores of the 

 Black Sea ; in other words that the mean annual temperature 

 was 20 lower than it is now along this line. 30 He adds that " the 

 Arctic plants and animals found fossil in Britain point to a similar 

 conclusion, for the same species now flourish in a climate fully 20 

 colder than that of the lowlands of Britain." 



Of the geographical changes which took place during the 

 Pleistocene period within the European area some have been 

 indicated in the preceding pages, but a brief summary of the 

 probable sequence of events may here be given, the reader being 

 warned that I only express the views of those who seek to avoid 

 extremes and to reconcile the different inferences which have been 

 drawn from the facts. 



At the beginning of the period, i.e. at the close of Pliocene 

 time, the British Isles were broadly united to the continent across 

 the English Channel and across the southern part of the North 

 Sea to Holland and Belgium. The Rhine discharged itself into 

 the North Sea Gulf near the coast of Norfolk, and the height of 

 Eastern England above sea-level was about the same as at present. 

 The western parts of the British region were, however, at a much 

 higher level than they are now, and Ireland may have been 

 broadly united to Scotland and England, though possibly a deep 

 narrow estuary, receiving a river from the north, lay between 

 Ireland and Wales. 



The first formation of glaciers in Ireland, Scotland, and Wales 

 may not have been accompanied by any terrestrial movement, and 

 the same may have been the case in Scandinavia. But of this 

 early glacial episode few traces remain, for most of the glacial 

 products of it would have been swept away by the subsequent 

 advance of the ice. 



There is good reason to believe that the great extension of 

 the ice and the consequent formation of ice-sheets coincided with a 

 general subsidence of Northern Europe, which enabled the ice to 

 spread much farther south than it otherwise would have done, and 

 to rise over the land in such a manner as to carry material from 

 lower to higher levels. The extent of this submergence in Britain 

 is at present uncertain, but it seems to have been greater in the 

 north, where the ice was thickest, and less in the south where the 

 ice-sheets terminated. TLus as stated on p. 615, Scotland seems 

 to have been about 600 feet lower than at present, while in the 

 south of England the difference was not more than 150 or 

 160 feet. 



But although we may infer a subsidence of that amount in the 

 area of the English Channel, we must not suppose that the Straits 



