BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 



Vol. 18, pp. 413-426, PLS. 40-42 NOVEMBER 22, 1907 



GLACIAL EROSIOJ^ IN THE NOETHPIOED* 



BY MARK JEFFERSON 



(Presented by title lefore the Society December 28, 1906) 



CONTENTS 



Page 



Introduction 413 



The tongues of tlie Jostedal ice slieet 415 



Kjeudals glacier 415 



Brixdals glacier 416 



Saeter glacier 417 



The Hanging valleys 418 



Reference to origin of hanging valleys *. 418 



Over B0dal 418 



Praestedal 418 



Valleys over Brengsnaes and Hogrending 418 



Tjugedal ' 420 



Skaala glaciers 420 



Headward erosion of hanging valleys 422 



Origin of botner-like fiord heads 424 



Erosion on Lofjeld 424 



Running water and its worli 425 



Unweathered detritus 426 



Conclusions 426 



References 426 



Introduction 



I went to Norway in the summer of 1904 to familiarize myself with 

 the work in modifying topographic forms that the largest ice sheet in 

 Europe is doing. This is the Jostedalsbrae, the word brae meaning any 

 permanent sheet of snow or ice, moving or stagnant, level or inclined. It 

 has an area of 360 square miles, and lies between the heads of Northfiord 

 and Sognefiord, distant from the Atlantic 60 and 90 miles respectively 

 by those fiords, at an elevation of about one mile above them. I visited 

 this ice sheet by the Northfiord because the Olden and Loen lakes at its 



* Manuscript received by tbe Secretary of the Society from the censor September 19, 

 1907. 



XXXVI — Bull. Geol. See. Am., Vol. 18, 1906 (413) 



