26o POLAR PROBLEMS 



Their want of correspondence, structurally and geologically, is favor- 

 able to the existence of such a channel. Also, arms of the oceans, rep- 

 resented by Weddell Sea on the one side and Ross Sea on the other, 

 do extend from either hemisphere into the Antarctic unknown in just 

 such locations as support the contention of a dividing channel. The 

 Ross Sea depression is well known to be a downfaulted area, referred to 

 by David and Priestley as a senkungsfeld. Does this senkungsfeld 

 extend right through to the Weddell Sea? 



Analysis of tidal data obtained from stations in the southern Ross 

 Sea led Darwin^ to conclude that a through passage from the head 

 of Ross Sea under the ice to the Atlantic Ocean was probable. 



The advocates of the separate identity of an East and a West 

 Antarctica look to King Edward VII Land as the prolongation to the 

 southwest of Graham Land, which may then be considered to pass 

 beneath the ocean and to reappear in the folded mass of New Zealand. 

 Unfortunately little is yet known of the structure and the rocks of 

 King Edward VII Land. So far as the available geological evidence 

 from the latter area is concerned, Nordenskjold reports, ^° after examina- 

 tion of rocks brought by the Amundsen expedition, that the result is 

 inconclusive. Amongst the suite of igneous rocks examined were 

 granodioritic rocks chemically like the Andean types but different 

 microscopically. They have an older facies, which, he remarks, is 

 rather suggestive that they are related to the older formations of 

 South Victoria Land. So we find that the very interesting question as 

 to the structural type to which King Edward VII Land belongs is still 

 unsettled. 



Though Filchner found the head of Weddell Sea to pass under a 

 great shelf ice (floating land ice) formation, just as in the case of Ross 

 Sea, yet it does not seem likely that a sea water channel extends 

 through under the shelf ice all the way. Discounting the probability 

 of a through channel also is the fact that Amundsen, on his journey 

 to the south pole along a route passing down the east side of the Ross 

 Sea depression, reported the appearance of rising ice slopes to the east 

 of his trail. This implies elevated ground over at least some part 

 of the area between the head of Ross Sea and that of Weddell Sea, thus 

 rendering unlikely the existence of a through passage of sea water 

 below the ice. 



As, however, the ice capping the Antarctic land reaches to enor- 

 mous thicknesses, it may be that the rising ice slopes — obviously ice 

 riding on a rocky bottom — seen by Amundsen to the east of the Ross 

 Sea shelf ice were resting on a basement still actually below sea level. 



9 Sir George Darwin: The Tidal Observations of the British Antarctic Expedition, 1907, Proc. 

 Royal Soc. of London, Ser. A: Math, and Phys. Sci., Vol. 84, 1910-11, pp. 403-422; reference on pp. 

 420-422. 



i"Otto Nordenskjold: Antarktis (Handbuch der Regionalen Geologie, Vol. 8, No. 6), Heidelberg, 

 1913. p. 16. 



