20 EEPOET— 1880. 



authors, wliicli are supposed to be of Upper Cretaceous age, there also are 

 boulder beds with erratic blocks of great size. 



I know of no evidence of glacial phenomena in Eocene strata except- 

 ing the occurrence of huge masses of included gneiss in the strata known 

 as Flysch in Switzerland. On this question, however, Swiss geologists 

 are by no means agreed, and I attach little or no importance to it as 

 affording evidence of glacier ice. 



Neither do I know of any Miocene glacier-deposits excepting those in 

 the north of Italy near Turin, described by the late eminent geologist, 

 Gastaldi, and which I saw under his guidance. These contain many large 

 erratic boulders derived from the distant Alps, which, in my opinion, 

 were then at least as lofty or even higher than they are now, especially if 

 we consider the immense amount of denudation which they underwent 

 during Miocene, later Tertiary, and post-tertiary times. 



At a still later date there took place in the north of Europe and 

 America what is usually misnamed ' The Glacial Epoch,' when a vast 

 glacial mass covered all Scandinavia, and distributed its boulders across 

 the north of Germany, as far south as the country around Leipzig, when 

 Ireland also was shrouded in glacier ice, and when a great glacier covered 

 the larger part of Britain, and stretched southward, perhaps nearly as 

 far as the Thames on the one side, and certainly covered the whole of 

 Anglesey, and probably the whole, or nearly the whole, of South Wales. 

 This was after the advent of man. 



Lastly, there is still a minor Glacial Epoch in progress on the large 

 •and almost unknown Antarctic continent, from the high land of which in 

 latitudes which partly lie as far north as 60° and 62°, a vast sheet of 

 glacier-ice of great thickness extends far out to sea and sends fleets of 

 icebergs to the north, there to melt in warmer latitudes. If in accordance 

 with the theory of Mr. Croll, founded on astronomical data, a similar 

 climate were transferred to the northern hemisphere, the whole of Scan- 

 dinavia and the Baltic would apparently be covered with glacier-ice, and 

 the same would probably be the case with the Faroe Islands and great 

 part of Siberia, while even the mountain tracts of Britain might again 

 maintain their minor systems of glaciers. 



Conclusions. 



In opening this address, I began with the subject of the oldest meta- 

 morphic rocks that I have seen — the Laurentian strata. It is evident to 

 every person who thinks on the subject that their deposition took place 

 far from the beginning of recognised geological time. For there must have 

 been older rocks by the degradation of which they were formed. And if, 

 as some American geologists afiirm, there are on that continent meta- 

 morphic rocks of more ancient dates than the Laurentian strata, there 

 must have been rocks more ancient still to afford materials for the de- 

 position of these pre-Laurentian strata. 



