256 IKlDljOl- NA.NSKN. M.-X. Kl. 



Relation between the Inclinations of the two Conspicuous Raised 

 Shore-Lines of Northern Norway and the Kola Peninsula. 



Ill nnrilicrii Norway tlicrc arc two especially conspicuous raised 

 shorc-liiKs, lo a j^rcal cxlcnl cut in solid rock. Amund Heiland [1900] 

 pointed out llie fact that llie [)lanes of inclination of these two levels do 

 not inlcrscct the sea-level alc^n.^' the same line, zero isobase, outside the 

 coast; but in the Troniso region ("JVonis i'\vlke) the hypothetical zero 

 isobase of the lower shore-line lies 8 to 17 kilometres further seawards 

 than that of the upper one. 



The two planes of inclination "intersect one another along- a line in 

 the air a few metres (on the average 5 metres) above the surface of the 

 sea". This line lies just over the outermost islands and skerries in the 

 Tromso distrikt. 



J. Rekstad states [1905, p. 21] that there is a similar relation between 

 the sloping- planes of the corresponding two levels of raised beaches and 

 terraces in Helgeland, and also on the Norwegian west coast (between 

 60" and 62« N. L.). 



Thinking that this peculiar relation between the two shore-lines 

 proves that the postglacial uplieaval did not extend so far seawards 

 during its first period, before the time of the lower shore-line, as it did 

 during its later period, Rekstad assumed this to be evidence against the 

 probability of the isostatic nature of the postglacial upheaval of the land, 

 for, he argued, as the load of the ice-sheet was first removed from the 

 border regions of the depressed area, one might expect an isostatic up- 

 heaval of the crust to begin in those outer regions and gradually extend 

 landwards, and not the other way. 



The inference from our studies of the strandfiat and the raised 

 beaches — that there may be distinguished between two movements in 

 the lateglacial and postglacial upheaval, a vertical change of the hori- 

 zontal level of the shore-line as indicated by the strandfiat, and a tilted 

 elevation of the land as indicated by the raised beaches — gives a simple 

 explanation of the above mentioned relation between the tilted planes of 

 the two shore-lines. 



Let us here, in order to simplify matters, assume for a moment that 

 the former movement be due to a postglacial sinking of the sea-level, 

 while the latter tilting movement is due to an upheaval of the depressed 

 land. Let us then take as an example a special case, c. g. Helland's 

 measurements of the heights of the two raised shore-lines at Helgoi 

 (70" 7' N. Lat.) and at Havnnes (69° 47' N. Lat.) in Lyngen Fjord in the 

 northern Tromso district. 



The heights of the two shore-lines were found to be 17 and 8 metres 

 on Helgøi and 60.9 and 22.8 metres at Havnnes. Let us assume that 

 17 metres is the height of the lower level of the strandfiat in tliis region, 



