THE HEART OF THE ANTARCTIC 



1000 ft. higher than it is at present, and when it spread 

 northwards into the Ross Sea, probably at least 100 to 

 200 miles north of its present seaward termination. 



As regards the reason for the plateau of Victoria 

 Land terminating in such steep mountain slopes east- 

 wards, it is of course possible, as Ferrar suggests, that 

 this is due to a heavy fault or series of faults running 

 parallel to the shore-line. Certainly the scenery, particu- 

 larly in the neighbourhood of Mount Nansen, and be- 

 tween that and Mount Melbourne, suggests a compara- 

 tively recent change of base, down to which the base 

 level forces have recently been working. In fact, these 

 glacier-cut valleys appear to us to be distinctly young in 

 their origin. The soundings in Ross Sea off this coast 

 have some interest as bearing on this question, as also 

 the presence of raised beaches in several places along the 

 coast, and on Ross Island. McMurdo Sound, from Ross 

 Island to the coast of Victoria Land, is only thirty miles 

 wide, and yet the sea is nearly 500 fathoms in depth 

 within a few miles of the coast. As evidence of crust 

 movements raised beaches may be quoted. On Ross 

 Island they were traced by us up to altitudes of 160 ft., 

 and organisms were found in these beaches such as are 

 found now living in the coastal waters, so that they 

 probably indicate an uplift since the deposition of these 

 organisms of a good deal more than 160 ft. At the 

 Ferrar Glacier on the mainland, raised beaches extended 

 up to at least 50 ft. above sea-level, and they reached 

 apparently to an altitude of 20 to 30 ft. on the coast 

 south-east of Mount Larsen, 200 miles further north. It 

 is possible that the latter may be due to upthrust of the 

 marine sediments by glacier ice. These changes in the 

 level of the shore-line have taken place in quite recent 

 geological time. It is, of course, possible that such 



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