GEOLOGY OF NORTH ATLANTIC GILLIGAN 209 



definitely proved, since they have not been found fossil in Iceland; 

 and neither the mammoth nor the musk ox has been found in the 

 Scottish highlands. In explanation he suggests that all Iceland now 

 above sea level may have been ice-clad at the time, and that they 

 passed over on land now submerged. 



II. EVIDENCES OF RECENT SUBSIDENCE IN THE NORTH ATLANTIC 



REGION 



The geographer royal of France, Tassin, some 250 years ago pro- 

 duced a map in which the sunken land of Busse or Rockall, now only 

 a rock, is shown, and which is said to have been coasted by one of 

 Frobisher's ships for three days. 



In 1897 W. Spottiswode Green made a scientific expedition to 

 Rockall, and he reported finding deep water on all sides, while the 

 bank on which Eockall stands has an average depth of about 100 

 fathoms. Dredging on the bank yielded only such shallow water 

 species of mollusks as could not have lived there under present condi- 

 tions. All the specimens were dead, and Green argued that the bank 

 must have subsided in comparatively recent time. In 1900 a Danish 

 expedition reported finding littoral mollusks at considerable depths 

 where these animals could not possibly have lived. The suggestion 

 has been made that these animals may have been brought to their 

 present positions by icebergs, but no icebergs reach Rockall at the 

 present time. 



Sir Archibald Geikie, in considering the distribution of the Ter- 

 tiary basalts over the North Atlantic area and the manner in which 

 they are now cut off by high vertical cliffs where they reach the 

 coast, came to the conclusion that much foundering of the original 

 continuous sheets must have taken place. 



ATLANTIS 



The theme of Atlantis has proved most attractive, and, as Profes- 

 sor Gregory pointed out in 1929,^ it has been placed by different 

 writers not only in some region of the Atlantic itself but also in each 

 and every one of the bordering lands. The subject was brought 

 prominently before the scientific world by Pierre Termier, of the 

 Geological Survey of France, in a paper read before the Institut 

 Oceanographique of Paris on November 30, 1912. In that paper he 

 recalls the dialogue in the Timseus of Plato. The story had been 

 handed down to Plato from Solon, who lived 600 years before the 

 Christian era, and Solon is said to have heard it from an Egyptian 

 priest at Sais, at the head of the Nile delta, during his visit to that 

 country. Plato did not live to finish the work, so that all we have is 



== Presidential address to the Geological Society of London. (See bibliography, p. 222.) 



