140 FRIDTJOF NANSEN. M.-N. Kl. 



.---•T^'V. 



,..,,^^..y-.f,,.^A 



Tuf F ^^^ M icoL- scktst ^^^P Gt^anitf 



Fig. 116. Profile along the broken line in the map P'ig. 115 north-westwards from Søla Islands aero- 



the horizontal scale. The profile in black on 



The northern part of Southern Herøi, south of Donna (see Fig. 113), 

 consists of gneiss-granite, mica-schist, and limestone. This region also 

 forms a strandfiat with a very level surface 8 metres above the sea. The 

 same level plane with the same height of 8 metres also occurs on Northern 

 Herøi (Fig. 113, A^lll) to the east and, as Sahlstrom points out, it is note- 

 worthy that the small rock in the sound beween the two islands has a flat 

 surface at just the same level. This is convincing evidence that the plane 

 has been formed by marine denudation (/'. c. shore erosion by frost) after 

 the sound had been deepened approximately to its present shape by glacial 

 erosion. The relief of this level surface cannot have been much modified 

 by glacial erosion after this small rock had been truncated, for otherwise 

 its flat top surface would certainly have been rounded and worn down to 

 a lower level. Across the middle part of Southern Heroi the strandflat 

 forms a very level plane between 6 and 7 metres above the sea. The 

 ground is composed of gneiss and limestones which are planed to exactly 

 the same level. 



In the southern part of Southern Heroi the plane of the strandflat 

 is between 4 and 5 metres above the sea, but not quite so level as further 

 north, ridges of gneiss-granite often rising slightly above the crystalline 

 limestone which forms the greater part of the surface. 



As Sahlstrom points out, it is noteworthy that on the remarkably 

 even strandflat described above tw^o kinds of rock so very different as 

 to their power of resistance as granite and limestone, are in some places 

 planed to exactly the same level, and in other places the difference of 

 denudation is only a couple of metres. 



According to Sahlstrom's measurements, as mentioned above, the 

 plane of the strandflat slopes slightly southwards, from about 10 metres 

 above the sea in the northern part of Donna to 4 or 5 metres in the 

 southern part of Southern Heroi. Sahlstrom considers it possible that 



