GLA CIA L S UC CESSION IN NOR WA V. 1 4 3 



and may by these means get some idea as to the length of the 

 first great ice age. The farther we go from our own time the 

 more wholly conjectural will our numbers becorne, of course. 

 But as other more reliable measures as yet are wanting, I shall 

 venture a first approximation, calculating the time in which the 

 enormous proteroglacial marginal glaciers eroded our fjords, as five 

 to ten times the epiglacial time in which our great epiglacial 

 lakes were scooped out— the higher estimate in this case being 

 somewhat more probable. This would perhaps make 100,000 to 

 150,000 years for the zvhole proteroglacial period, i. e., about five 

 times the duration of the deuteroglacial time — a relation which, 

 as far as I see, is in very good accordance with the general 

 quantitative difference between the effects of the first and second 

 great glaciations. This will give for the whole Quaternary-post- 

 tertiary time about 140,000-200,000 years. 



I see very well how precarious such computations may seem, 

 especially as I here cannot give the detailed calculations — but I 

 do not think it possible that any of these have given numbers 

 five times too great or small. Under these circumstances 

 they must be taken for a very good geological approximation. 

 By getting parallel estimates from other glaciated countries, it 

 will appear, I think, that we will have, on wholly geological ground, 

 more positive and reliable data for the Quaternary chronology, 

 than those derived from astronomical speculations. 



I add for greater ease in comparison my reading of the 

 Quaternary history of Norway in a tabular form. 



Andr. M. Hansen. 



