I92I. No. II. THE STRANDFLAT AND ISOSTASY. 161 



If the isobath for 40 metres of depth be assunied to form the boundary 

 of the platform its width varies between 7 and less than 2 kilometres. 



As pointed out by Th. \ ogt the submerged strandfiat is most 

 distinctly developed outside the coast at Refsvik (near the southern end 

 of the island) where the land is built up of labradorite rock. He thinks 

 this might l)e due to the fact that this rock is somewhat less resistant 

 to erosion than the other gabbros of Lofoten. There is here a platform 

 nearly 2 kilometres broad, with numerous shoals and rocks near sea-level 

 and some emerging above it, and the outer edge of the platform is sharply 

 defined. 



It seems doubtful whether the greater part of the submerged plat- 

 form outside Aloskenesoi with its surface at depths between 30 and 40 

 metres and even between 40 and 50 metres, can actuallv, in its present 

 shape, be considered as a submerged strandfiat. It seems hardly probable 

 that it can have been formed at a level so deep below present sea-level. 



Th. \ ogt may be right in thinking that the reason why there is less 

 of a strandfiat round Aloskenesøi than on the \^æroi and Røst Plateaus, 

 may be that there has been a more vigorous glacial erosion under the high 

 mountains of this island. It seems to me probable that it is the glacial 

 erosion which has lowered the level of the submerged platform along the 

 outer coast of Moskenesoi, although the surface of this platform is more 

 even and less deeply dissected by channels or hollows than is generally 

 the case where there has been an effective erosion by glaciers. It seems 

 also difficult to understand why there is no submerged strandfiat along 

 the inner coast of Moskenesoi. The less effective marine erosion on the 

 inner, less exposed coast is not sufficient to account for this fact, for 

 we would at any rate expect some indications of a submerged platform, 

 even though narrow, especially as there actually is an emerged strandfiat, 

 and there are parts of a submerged one along the coast further to 

 the north-east in \'est Fjord, and a well developed submerged strandfiat 

 often occurs along more sheltered coasts. 



Is it perhaps possibile that the big glacier which deepen?d the 

 \'est Fjord, has cut away the submerged strandfiat? 



It is, however, also obvious that the nature of the rocks has some 

 connection with these differences in the development of the submerged 

 strandfiat, for here again we find the same feature, that the submerged 

 platforms cut in more resistant rocks have greater depths and more sloping 

 surfaces than those cut in weaker rocks. The gneiss of the Værøi and 

 Rost Plateaus is certainly considerably less resistant to glacial erosion 

 as well as to shore erosion than the rocks of Moskenesoi. 



It seems probable that these platforms cut in very resistant rocks 

 where the initial land was comparatively high, have required a verv long 

 time for their formation. They are therefore comparativelv old, and have 

 been exposed to much glacial erosion during several glacial periods. The 



Vid.-Selsk. .Skrifter. I. M.-N. Kl. 1921. \o. 11. 11 



