13 
1915-16.] Opening Address by the President. 
prolonged period of glaciation. It must also be admitted that many 
glacialists who adopt the interglacial theory in a modified form have given 
a different interpretation of some of the details from that advanced by 
James Geikie. At the same time, it is a remarkable fact that the careful 
mapping of glacial deposits in the Alps and North America has led dis- 
tinguished investigators to similar conclusions regarding the sequence of 
events in the Ice Age. 
The elaborate investigations of Penck and Bruckner, described in their 
monumental work Die Alpen im Eiszeitalter, have demonstrated four 
glaciations of the Alps, separated by interglacial periods. The evidence is 
based on a succession of gravels at different levels, stretching down the 
valleys. When traced upwards towards the mountains, these sheets of 
gravel are associated with moraines. Their classification is given below in 
descending order : — 
4. The Wtirm Glaciation, associated with the Lower Terrace. 
3. The Riss Glaciation, associated with the Higher Terrace. 
2. The Mindel Glaciation, associated with the Younger Deckenschotter. 
1. The Gtinz Glaciation, associated with the Older Deckenschotter. 
The evidence points to a severe glaciation of the Alpine region during 
the First or Giinzian Epoch. Glaciers descended the mountain valleys, 
indicating a depression of the snowline of about 4000 feet. The gravel 
outwash (Older Deckenschotter) has been extensively denuded, being 
preserved in narrow strips and outliers at considerable altitudes above the 
present lines of drainage. This deposit has been widely distributed on 
the northern side of the Alps, where it reaches a thickness of about 100 
feet. At certain localities it has been cemented into a hard conglomerate, 
and, at the surface, shows the effects of weathering and solution. 
The extensive erosion of the Older Deckenschotter implies a long 
interval of deglaciation during the First or Gtinz-Mindel Interglacial 
Period. But it is extremely difficult to identify interglacial deposits of 
this age beneath the later glacial materials. Some have referred the 
lignite beds of Leffe with remains of Elephas meridionalis and Rhinoceros 
leptorhinns in Northern Italy to this stage, but this correlation is extremely 
doubtful. 
The renewed advance of the glaciers during the Second or Mindel 
Glaciation is proved by the development of moraines and the accompanying 
Younger Deckenschotter. Along part of the northern border of the Alps 
they are the most extensive of the glacial formations ; in other areas they 
nearly coincide with the limits of the Riss drift of the Third Glacial 
