I92I 



. No. 1 1 . 



THE STRAXDFLAT AND ISOSTASY. 



247 



Yttre Sulen, across the outer part of Atleoi to Rugsund near tlie mouth 

 of Nord Fjord. Let us furthermore assume that the isobases for greater 

 elevations further inland follow directions parallel to this line. 



In the following table are given: 1) the direct distance of each locality 

 mentioned from the isobase for 17 metres, 2) the height of the upper limit 

 of lateglacial submergence above the lower level of the emerged strandfiat 

 (as given in the table on p. 246), 3) the gradient of the postglacial 

 elevation (minus the height of the strandfiat) a) between the isobase for 

 17 metres and the locality, and b^ between each locality. 



Localitv 



Distance from 



the isobase for 



1 7 metres 



Height of upper 



marine Hmit above 



lower level of 



strandtlat 



Gradient of Elevation 



from isobase for 

 1 7 metres 



between the 

 localities 



Vadheim 

 Ortne\-ik 



Vik 



Ho viand . 



S2 kilometres 



95 



143 



00 metres 



103 



128 



1. 1 5 per mDle 

 0.99 • 

 1.08 » 

 0.89 • 



) 0-53 per mille 

 ) 1-37 * 

 } 0.52 ' 



The gradients between X'adheim and Ortnevik and between Ortnevik 

 and \'ik differ much from each other and from the gradient between Vad- 

 heim and the isobase for 17 metres. If we assume that the terrace 

 measured at Ortnevik does not actually give the upper limit of sub- 

 mergence, and if we take the gradient between \'adheim and \ ik, we find 

 it to be i.oo per mille, which is slightly lower than the gradient 1.15 per 

 mille between \'adheim and the isobase for 17 metres. 



The gradient in the inner part of the fjord, between \*ik and Hov- 

 land in Ardais Fjord, is very low, 0.52 per miille. The difference between 

 this gradient and the gradient in the outer part of the fjord is much too 

 great to be explained by the regular decrease of the gradient of elevation 

 inland towards the central region of the depressed area. Rekstad is ob- 

 viously right in assuming that the highest terraces at Hovland do not 

 mark the upper limit of submergence, because the inner part of the fjord 

 was filled with glaciers during the time of greatest submergence, and 

 when the glaciers retreated and the terraces could be deposited, the land 

 had already begun to rise. 



The probability of this explanation is confirmed by Rekstad's 

 measurements of the upper marine limit in the inner part of Hardanger 

 Fjord and by H. Kaldhol's measurements of the raised terraces in Xord 

 Fjord. 



The observations made in Xord Fjord are of special interest to us 

 here in another respect. 



