288 KKIUTJOF NANSKN. M.-N. Kl, 



(lislurl)c'l, llie sca-lcxfl mav liri\c- rciiiaiiicil fairly stable for a considerable 

 time after its rise. 



As far as I can see, a shift of the sc-a-level and the shore-line such as 

 this would be sufficient to gi\e a simple explanation of the Tapes-Littorina 

 trans_i,''ression. 



I )urin,L; the periofls preceedin^- tlie Tapes-Littorina period the climatic 

 temperature of tlie t'artli was on tlie whole rising, but there were probably 

 several fluctuations in this rise, flue to fluctuations in the radiation of 

 heat from the sun. There has been a correspoiulinj^'- reduction of the ice- 

 cai)s of the earth, with similar fluctuations, whicli caused a correspondingly 

 fluctuating rise of the general sea-level. 



Along great ])arts of the coasts of ]<"enno-Scandia, this rise of sea- 

 level was more or less masked by the still faster upheaval of the land, and 

 it was only during certain periods wdien the temperature was much raised 

 and the melting of the ice-caps much increased, that the rise of sea-level 

 was sufficientiv rapid to cause a j)ause in the negative shift of the shore- 

 line so considerable that conspicuous marine terraces, beaches, or shore- 

 lines could be developed. 



It seems possible that the different stages or interruptions in the 

 upheaval of the land, marked by the series of marine terraces and raised 

 beaches along the coast of Norway may be thus explained. 



In the Tapes-Littorina period the rise of the general sea-level was 

 sufficiently rapid to cause a transgression of the sea along some parts of 

 the slowly rising coasts. 



After this period the climates of the earth have again become some- 

 what colder. It is, therefore, possible that the ice-caps of the Antarctic 

 and of Greenland have increased somewhat in thickness. In Spitsbergen, 

 as was previously mentioned, there are indications of such a recent in- 

 crease of the glaciers. 



Hence a slight sinking of the general sea-level would be caused after 

 the Tapes-Littorina period. A sinking of sea-level would also be caused 

 by the gradual isostatic depression of the sea-floor, caused by the previous 

 increase of the water masses of the Ocean. If at the same time there has 

 been some upheaval of the coasts caused by the depression of the sea-floor, 

 the negative shift of the general shore-line would be increased accordingly. 



We would thus obtain an explanation of the general negative shift 

 of the shore-line, or apparent sinking of the general sea-level, of about 

 20 feet or 6 metres in recent time to which Reginald A. Daly [1920] has 

 drawn attention. 



It was previously mentioned that the apparent anomalies pointed out 

 by A. G. Högbom in the relation between the upheaval of the land since 

 the Åloppe culture (of the Stone Age), and the upheaval since the Littorina 

 period, may be explained by a sinking of sea-level since that time. 



