226 t KIDTJOF NANSKN. M.-X. Kl. 



hl llic rf,ij;-i()iis uf niorc rcsisiaiil rocks, c. g. outside llie coasts of 

 Soiifliiior, konisdal, Nordmor, Lofoten, X'esteràlen, Senjen, &c., the con- 

 liiieiilal shelf is comparati\ely narrow, its surface fairly level, and its 

 depth below present sea-level to a j^rcat extent less than 150 metres, and 

 in some reg'ions even less than io(j metres, while the siiitmerj^a-d strand- 

 flat, as we liavc seen, is also narrow, hut is comparatively uneven and 

 irrcg-ular, slopinj^ scawarrls, and lyinj^^ deeper helmv present sea-level than 

 in the reg'ions of weaker rocks. There is often n<j very sharply defined 

 boundary between the low strand flat anrl the hij^di inner jtart of the con- 

 tinental shelf. 



Althouj^h tlie submerged strand flat is very broad outside Helgeland, 

 its outer side slopes seem to have been cut back more and to have been 

 made steeper in the regions of weaker rocks than in those of more 

 resistant ones. Its very level surface in the former regions seems there- 

 fore largely to be of a younger age than the more uneven surface of the 

 latter regions. 



Let us now leave the strandfiat for a while anrl consider the form- 

 ation of the continental shelf. 



