212 Dr. N. 0. Eolst~The Glacial Period and 



part of it above the surface. It may therefore be objected that, 

 even though the land-connection in question may really have existed, 

 still it is in itself no proof of any considerable elevation, certainly 

 not of one great enough to explain the severe climate of the Glacial 

 Period. And this, no doubt, is perfectly true. 



But there are other evidences for a much greater elevation in the 

 north-west of Europe. That the agreement between the floras of 

 Scandinavia, Scotland, the Faeroes, Iceland, and Greenland necessarily 

 presupposes a land-connection in Quaternary times, has been long 

 understood. Such a connection involves an elevation of the sea-floor 

 between Scotland and Greenland of about 3,000 feet (891 metres).' 

 But did such an elevation really take place during the Quaternary 

 Period ? Conclusive proof of it was given by A. S. Jensen,- when 

 he demonstrated the logical consequences of the discoveries made 

 by the Ingolf expedition in 1896 during the investigation of the 

 sea-floor between Jan Mayen and Iceland. Here the expedition 

 found at a great depth, reaching as much as 1,309 Danish fathoms,^ 

 such shalloio-wdiiev bivalves as Astarte BanJcsii, A. borealis, A. com- 

 pressa, Cardtum ciliatum, C. groenlandicum, Cyrtodaria siliqua, 

 Macoma calcaria, Saxicava arctica, and Yoldia arcttea. These 

 marine molluscs, which can live only at small depths, according 

 to Jensen in not more than 100 fathoms of water, occur in great 

 numbers, and it is quite clear that they have lived where their 

 shells now are met with. These discoveries therefore prove that 

 the sea-bottom between Scandinavia and Greenland once lay more 

 than 1,200 fathoms (2,138 metres) higher than now. As for the 

 date of the elevation, Jensen justly observes that the occurrence 

 of Yoldia arctica is enough to show that it took place during the 

 Glacial Period. During which part of that period the elevation 

 existed is not discussed by Jensen, but it is most reasonable to refer 

 it to the beginning of the period, when an elevation is established 

 both for England and Scandinavia.* If this elevation started from 

 the Archaean district of Scandinavia and of Greenland, as there is 

 good reason for supposing, then the elevation of Scandinavia must 

 have been greater than that demonstrated by Jensen for the sea-floor 

 between Scandinavia and Greenland. But if the elevation was only 

 of the same, or even approximately the same magnitude, it was still 

 quite enough to afford an explanation of the Glacial Period itself. 



But this elevation of the sea-floor between Scandinavia and 

 Greenland carried with it another important consequence, in that 

 it changed this part of the ocean into an inland sea, comparable 

 with the Mediterranean, and united with the body of the Atlantic 

 only by the deep channel between the Shetlands and Faeroes.^ 



^ See the map to "W. H. Hudleston's paper " On the Eastern Margin of the North 

 Atlantic Basin" : Geol. Mag., 1899, Dec. lY, Vol. VI, p. 97. 



^ " Om Levninger af Grundtvandsdyr paa store Hardyb mellem Jan Mayen og 

 Island" : Vidensk. Meddel. Naturhist." Foren. Kobenhavn, 1900, p. 229. 



3 8,087 English feet ; 2,465 metres.— Translator. 



* The same elevation also reached Iceland. See Th. Thoroddsen in Geol. Foren. 

 Stockholm Fbrhandl., 1900, xxii, p. 546. 



* Cf . Hudleston's map cited above. 



