THE "GREAT IGE AGE." 127 



main after the glaciers had all melted away, and the sea 

 had receded sufficiently to expose their submarine de- 

 posits. 



Throughout the above I have assumed a considerable 

 submergence of the land as compared with the present sea- 

 level on the coasts of Scotland, Scandinavia, etc. 



The universality of the terraces in all the Norwegian 

 valleys opening westward proves a submergence of at least 

 600 or 700 feet. When I first visited Norway in 1856, I 

 accepted the usual description of these as alluvial deposits; 

 was looking for glacial vestiges in the form of moraines, 

 and thus quite failed to observe the true nature of these 

 vast accumulations, which was obvious enough when I re- 

 examined them in the light of more recent information. 

 Some few are alluvial, but they are exceptional and of 

 minor magnitude. As an example of such alluvial ter- 

 races I may mention those near the mouth of the Romsdal, 

 that are well seen from the Aak Hotel, and which a Rus- 

 sian prince, or other soldier merely endowed with military 

 eyes, might easily mistake for artificial earthworks erected 

 for the defence of the valley. 



In this case, as in the others where the terraces are allu- 

 vial, the valley is a narrow one, occupied by a relatively 

 wide river loaded with recent glacial debris. It evidently 

 filled the valley during the period of glacial recession. 



The ordinary wider valleys, with a river that has cut a 

 narrow channel through the outspread terrace-flats, display 

 a different formation. Near the mouth of such valleys I 

 have seen cuttings of more than a hundred feet in depth, 

 through an unbroken terrace of most characteristic till, 

 with other traces rising above it. This is the ordinary 

 constitution of the lower portions of most of the Scandi- 

 navian terraces. 



These terraces are commonly topped with quite a dif- 

 ferent stratum, which at first I regarded as a subsequent 

 alluvial or estuarine deposit, but further examination sug- 

 gested another explanation of the origin of some por- 

 tions of this superficial stratum, to which I shall refer 

 hereafter. 



Such terraces prove a rise of sea or depression of land, 



