808 



tides from being transported to the Faeroes from all sides under 

 favourable winds. 



I have likewise quoted what has been published since War- 

 ming's paper against the theory of a postglacial land-bridge by 

 A. C. Johansen^, Helgi Pjetursson^ and also a discussion by 

 Fridtjof Nansen who refers especially to his ow^n works ^. But 

 the most important article concerning this matter is of recent date 

 a nd due to Prof. T h . T h o r o d d s e n . 



In a paper published in February 1905^ he sets forth argu- 

 ments against a postglacial land-bridge from a geological point of 

 \iew. At my request, Prof. Thoroddsen has very kindly given 

 me a short resume of his paper, w^hich I give here: 



»A land-bridge of basalt existed across the Atlantic from Scotland 

 to the Faeroes, Iceland and Greenland at the beginning of the Miocene 

 period, but the tectonic features of Iceland, the displacements of the 

 basalt-sheets and the relation of the beds of »Surtarbrand« to the lines 

 of faults show, that the country was not much larger at the end of 

 the Miocene period than it is now\ The land-bridge had sunk into 

 the sea. During the Pliocene period Iceland's systems of valleys and 

 rivers w^ere formed in the basaltic regions. These systems conformed 

 closely to the present form of the country. Thereafter doleritic, later 

 striated lava-streams flowed dow^n into the valleys, and at the time 

 these doleritic lava-beds were laid down, the basaltic regions had 

 pretty much the same essential contours as at present. The dole- 

 ritic, striated lava-streams are either preglacial or glacial, that is, 

 they date from an earlier period than that during which the land 

 w^as last covered by ice. The pliocene valley's and fjords are con- 

 tinued by deep channels out to the edge of the submarine plateau^ 

 and at east Iceland even on to the submarine ridge. These channels 

 are no doubt older than the last ice period in Iceland and younger 

 than the submarine ridge. The Red-Crag-beds in North-Iceland show 

 also, that there was no connection betw^een Iceland and Greenland 



^ A. C. Johansen: »0m den fossile kviirtiere Molluskfauna i Danmark og dens 

 Relationer til Forandringer i Klimaet«, Kobenhavn 1904, p. 42. 



^ Helgi Pjetursson: ^Om nogle glaciale og interglaciale Vulkaner paa Island«, 

 (Oversigt over d. kgl. danske Videnskabernes Selskabs Forhandlinger 1904, n:o4), p. 266. 



^ Fr. Nansen: The Oceanography of the North Polar Basin (The Norwegian 

 N. P. Expedition, vol. Ill, Nr. 9 pp. 419 — 420). Fr. Nansen: 2>The bathymetrical fea- 

 tures of the North Polar Seas with discussions of the continental shelves and pre- 

 vious oscillations of the shore line (Ibid. Vol. IV. 1904). 



* Th. Thoroddsen: Hypotesen om en postglacial Landbro over Island og 

 Faeroerne set fra et geologisk S3 nspunkt (>Ymer<. 1904. H. 4, Stockholm). 



