ESKAR EXCAVATION IN NOVA SCOTIA. PREST. 43 



layers are confused b}^ the growth of vegetation and the effects 

 of frost. 



We have in this eskar evidences of two periods of erosion, 



two periods of deposition, and a period of mineral precipitation. 



These represent apparently, no sudden changes of 



Sumynary climate or increase or decrease of rainfall, but 



evidence ^"^h" the conditions seen in the average rapid 



stream. There the erosion and transport of 



material forms or removes pools and rapids as a river erodes 



its bed. 



In drawing conclusions from these observations we must 

 remember that this section was made on but one portion of 

 a long eskar, which differed in height, breadth, 

 Endence '^^^ environment in its different parts. It is 

 limited only by averaging the results from many sec- 

 tions that correct conclusions can be arrived at. 

 I think however that the following may be accepted as 

 a working hypothesis. The eskar material, while being 

 gathered, was thrust forward in the general glacial 

 A working movement. All this time the enclosed debris, 

 hypothesis according to evidence of polar expeditions, was 

 subject to the most tumultuous agitation by the 

 streams of water poured into the crevasse by the melting 

 summer sun. This was the first stage of eskar formation. 

 Then came .a pause and the process of stratification. 

 The melting ice gave up its enclosed material, adding to that 

 already gathered. And this material was continually worn, 

 rolled, and gradually shifted from higher to lower levels as 

 long as water remained in the crevasse. This condition, of 

 course, ended on the higher sooner than on the lower ground. 

 But all these conditions were localized and probably repeated 

 many times in the same place as the ice sheet proceeded 

 toward its dissolution. 



That water transport of heavy material has thus been 



effective is seen in the immense eskars that traverse river 



valleys. Such a ridge is seen at Nine Mile River, 



Other Hants County, Nova Scotia. Here is seen an 



NovaScolia enormous eskar 50 feet high and often 300 feet 



wide. It traverses the valley, usually parallel to 



the river but sometimes crossing it. There is evidence to 



