CHAP. Vlt 



THE GLACIAL EPOCH 



109 



Exactly similar mounds are found in the valleys of North 

 Wales and Scotland, and always where the other evidences 

 of ice-action occur abundantly. 



Travelled Blocks. — The phenomenon of travelled or 

 perched blocks is also a common one in all glacier 



A GLACIER WITH MORAINES. 



countries, marking out very clearly the former extent of 

 the ice. When a glacier fills a lateral valley, its foot will 

 sometimes cross over the main valley and abut against its 

 opposite slope, and it will deposit there some portion of its 

 terminal moraine. But in these circumstances the end of 

 the glacier not being confined laterally will spread out, 



