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PHYSICAL GEOLOGY 



Fiords. 1 — The coast of Norway is noted for the long, narrow bays, 

 called fiords (Fig. 149), which may be navigated for many miles. 





Fig. 149. — Fiord, Grenville Channel, British Columbia. (U. S. Geol. Surv.) 



Into these fiords streams enter from hanging valleys over falls. 

 Soundings show that while the end towards the sea is very deep, it 

 is not so deep as at some distance inland. The maximum depth of 

 the Sogne fiord in Norway (Fig. 150) is 4000 feet, and that of three 



others is 2550, 2298, and 

 1800 feet. The greatest 

 depth occurs where the 

 fiord is bounded by moun- 

 tain masses of great extent 

 and elevation. 



There seems little doubt 

 that fiords are valleys 

 which were greatly deep- 

 ened by glacial erosion. 

 Their increased depth from the outlets inward is due either to the 

 greater erosion of the glaciers some distance inland, where they were 

 presumably thicker and their erosive power consequently greater; or 

 to the piling up of morainic matter where they entered the ocean ; or 

 probably both cooperated to produce the result. Whether or not the 

 glaciers actually cut the valleys below sea level has not been proved. 



1 It has been maintained that fiords owe their characteristics to earth movements and not 

 to glacial action, and, in fact, that fiords occur in non-glaciated regions. According to this 

 theory areas were fractured along certain belts as they were being raised to form plateaus. 

 belts of more or less shattered and fissured rocks are supposed to have subsided, with the 

 formation of steep sided troughs. In support of this theory it is pointed out that fiords are 

 arranged along a kind of angular network believed to be caused by intersecting lines of frac- 

 tures. (Gregory, J. \V., — The Nature and Origin of Fiords, 1913.) 



Fig. 150. — Map of Sogne fiord, Norway. 



