GLA CIA L S UC CESSION IN NOR WAY. I 3 7 



general post-glacial upheaval, and as the depression in southern 

 Sweden may be a quite local, peripheric phenomenon attached 

 to the Baltic, I must insist upon the more significant, yet neutral, 

 form siibglacial period for the age of the lower beach line. 



The inland ice was then, as explained, reduced to a zone 

 (about 50 kilometers broad) across the middle of the eastern val- 

 leys. This fact must have a curious consequence in the fact that 

 these valleys must have been dammed up by the ice and filled with 

 lakes whose outlets ran west and north through the gaps in the 

 watershed. These glacial lakes have actually left very distinct 

 marks in the greatest eastern valleys in Norway, Gudbrandsdal 

 and Oesterdal. We not only find in their upper tracts enormous 

 terraces of material brought by the glacier from the south, terraces 

 without any parallel on the other side of the watershed, but we 

 also find here very fine beach lines — seter — partially cut in the 

 rock, corresponding in height with the terraces and with the 

 draining gaps, 620", 660'" respectively — quite like the famous 

 Parallel roads of Lochaber, but very much more extensive. 

 From these ice-dammed subglacial lakes there flowed great rivers 

 across the present watershed filling up with their heavy sediment 

 many of the epiglacial lakes on the northwestern coast, and 

 building great subglacial clay terraces at the level of the lower 

 ancient sea beach. 



The erosion of the marginal glaciers has set its mark also in 

 the subglacial time in some inland lakes as Storsjo and Sensjo, 

 in Oesterdalen, Mosvatn and Totak, in Telemarken which have 

 their greatest depth in the upper part and terminal moraines at 

 the present upper end of the lakes. 



So far as I can see the subglacial period also prevailed in North 

 America, without receiving yet, however, due attention from 

 glacial students. I cannot here deal with all the raised beaches 

 in the east formed by the sea and by the lakes which naturally 

 can be referred to this period, but I shall use the occasion to 

 point out that the apparently insoluble difficulty in harmonizing 

 archeological and biological facts with the geological data con- 

 nected with the ancient "Quaternary" lakes in the Great Basin 



