I92I. No. II. THE STRANDFLATAND ISOSTASY. I75 



Nathorst and J. G. Andersson [1900, p. 439]. As the latter points out it is 

 possible that such marks might have been obliterated along these shores 

 where the rocks have but little power of resistance and the postglacial 

 erosion, especially by frost, has been considerable. But if there had been 

 shore-lines or shore-cliffs on the strandfiat further inland, it seems none 

 the less probable that some traces of them might have been found some- 

 where. 



As long as there is no evidence to the contrary we may therefore 

 assume as most probable that this island has had no postglacial elevation, 

 as seems also to be the case on other small island plateaus like that of the 

 Faeroes, Shetland, and possibly Jan Alayen. 



It might be more probable that there has been a positive movement 

 of the shore-line in postglacial time, otherwise it may, for instance, be 

 difficult to explain why there is not a broader submerged shore bench 

 near present sea-level round the island, if the present-day shore was ex- 

 posed during the whole of postglacial time to the very effective shore- 

 erosion now going on. In the few places where a quite narrow shore bench 

 with shallow water has been developed, c. g. Walrus Harbour, Norwegian 

 Harbour, Herwig Harbour, North Harbour, and west of that region, the 

 shore is built up of rocks, with very little power of resistance to erosion, 

 and where it cannot have taken a long time to erode the existing sub- 

 merged shore benches. 



In spite of the considerable postglacial elevation of the land that has 

 taken place in Scandinavia to the south and on Spitsbergen to the north, 

 and also on Franz Joseph Land, the disappearance of the ice cap has 

 probably caused no appreciable postglacial elevation of the crust in this 

 region, for during the last glacial period the island was probably covered 

 by a small local glacier only, the weight of which depressed the crust less 

 than the sea-level was temporarily lowered by the reduction of the volume 

 of the Ocean owing to the accumulation of frozen water on land. 



But of more importance in this respect is probably the considerable 

 displacement of the semi-plastic 'magma' underlying the rigid Earth's 

 crust, which must have taken place when by the weight of the ice caps 

 Scandinavia to the south was depressed 300 metres, or more, in its 

 central parts and Spitsbergen some hundred metres to the north. By 

 the displacement of the 'magma', the intervening region of Bear Island 

 has probably been raised, and when, after the disappearance of the ice- 

 caps, the displaced 'magma' again 'flowed' slowly back to its former 

 position more or less, and the previous equilibrium was restored, there 

 would be a slow subsidence of the crust in the region of Bear Island. 



If in this manner, the shore-line in the Bear Island region stood 

 during the glacial time about 30 or 40 metres lower than now, the plat- 

 forms may have been formed which now are submerged about 30 and 

 40 metres below present-day sea-level. 



