146 



PROFESSOR JAMES GEIKIE ON THE 



There can be no doubt, then — indeed it is generally admitted — that the cold 

 conditions that culminated in our Glacial Period began to manifest themselves in Pliocene 

 times. Moreover, as it can be shown that Elephas meridionalis and its congeners 

 lived in Central Europe after an epoch of extensive glaciation, it is highly probable that 

 the Forest-bed, which contains the relics of the same mammalian fauna, is equivalent in 

 age to the early interglacial beds of France and the Alpine Lands. We seem, therefore, 

 justified in concluding that the alternation of genial and cold climates that succeeded the 

 disappearance of the greatest of our ice-sheets was preceded by analogous climatic changes 

 in late Pliocene times. 



I shall now briefly summarise what seems to have been the glacial succession in 

 Europe : — 



Glacial 



1. Weybourn Crag ; ground-moraine of great Baltic Glacier underlying " lower 

 diluvium ; " oldest recognised ground-moraines of Central Europe. 



These accumulations represent the earliest glacial epoch of which any trace has 

 been discovered. It would appear to have been one of considerable severity, but not 

 so severe as the cold period that followed. 



f 2. Forest-bed of Cromer; Hotting breccia; lignites of Leffe and Pianico; inter- 

 iDterglacial . \ glacial beds of Central France. 



[ Earliest recognised interglacial epoch ; climate very genial. 



Glacial 



3. Lower boulder-clays of Britain; lower diluvium of Scandinavia and North 

 Germany (in part); lower glacial deposits of South Germany and Central Russia; 

 ground-moraines and high-level gravel-terraces of Alpine Lands, &c. ; terminal 

 moraines of outer zone. 



The epoch of maximum glaciation ; the British and Scandinavian ice-sheets con- 

 (. fluent ; the Alpine glaciers attain their greatest development. 



Interglacial 



4. Interglacial freshwater alluvia, peat, lignite, &c, with mammalian remains 

 (Britain, Germany, &c, Central Russia, Alpine Lands, &c.) ; marine deposits (Britain, 

 Baltic coast-lands). 



Continental condition of British area ; climate at first cold, but eventually tem- 

 perate. Submergence ensued towards close of the period, with conditions passing from 

 . temperate to Arctic. 



Glacial 



5. Upper boulder-clay of Britain ; lower diluvium of Scandinavia, Germany, &c, 

 in part ; upper glacial series in Central Russia ; ground- moraines and gravel-terraces 

 in Alpine Lands. 



Scandinavian and British ice-sheets again confluent, but oner de glace does not 

 extend quite so far as that of the preceding cold epoch. Conditions, however, much 

 more severe than those of the next succeeding cold epoch. Alpine glaciers deposit 

 b the moraines of the inner zone. 



