ANTARCTIC EXPLORATION AND RESEARCH 259 



When inquiring into the possibiHties along these lines we are ar- 

 rested by a fact, long ago emphasized by Nordenskjold^ and others, 

 to the effect that the geology, including both lithology and tectonics, 

 of that prolongation of Antarctica lying southward of Cape Horn^ 

 the Graham Land peninsula — is totally unlike that prevailing in the 

 lofty land mass lying to the south of Australia, typified by South 

 Victoria Land. 



Nordenskjold refers to the former as West Antarctica and to the 

 latter as East Antarctica. These are useful terms for the purpose of 

 the present review. Much has been written^ regarding the unity on 

 the one hand and the individuality on the other hand of these two land 

 masses. 



The labors of Nordenskj old's Swedish expedition and of Charcot's 

 French expeditions in West Antarctica have shown a relationship in 

 rock types and in tectonic features of that region with those of the 

 southern tip of South America. The presence of Andean granodiorites 

 is especially remarked, and there is evidenced true Andean folding. 



Suess long ago held that the Andean fold chain swung around 

 to the east in the neighborhood of Tierra del Fuego and could be traced 

 beneath the sea in a great sweeping curve reappearing at intervals in 

 the islands of South Georgia, the South Orkneys, South Shetlands, and 

 finally extending into Graham Land. But Nordenskjold has clearly 

 indicated^ that the connection is more apparent than real in a geologi- 

 cal sense, for those island groups referred to are structurally older 

 than the period of Andean orogeny. In no case, however, is there 

 any question as to the good evidence of the recurrence in West Ant- 

 arctica of Andean characteristics. How far this condition of things 

 continues to the south and southwest beyond Charcot Land is a 

 first-class problem of outstanding interest. 



The build of East Antarctica is in direct contrast to the foregoing. 

 Here we have a great elevated land mass which, so far as yet explored, 

 is a region of block uplifts on a grand scale and has in its tectonics 

 nothing corresponding to the folding in late geological times evidenced 

 in West Antarctica and the Andean cordillera. It has long been 

 recognized that in its structure South Victoria Land closely corre- 

 sponds with that of Australia, whereas the tectonic features of West 

 Antarctica are akin to those of New Zealand. 



Now, the question that has been long before us is whether or not 

 an arm of the sea separates East Antarctica from West Antarctica. 



s Otto Nordenskjold: Antarctic Nature, Illustrated by a Description of North- West Antarctica, 

 Ceogr. Journ., Vol. 38, 191 1, pp. 278-289; reference on p. 278. 



' British Antarctic Expedition, 1907-9, Reports on the Scientific Investigations: Geology, Vol. 

 I: Glaciology, Physiography, Stratigraphy and Tectonic Geology of South Victoria Land, by T. W. 

 Edgeworth David and R. E. Priestley, London, 1914, especially Chs. i and 20. See also the publica- 

 tions cited above in footnotes i and 6. 



8 Nordenskjold, op. cit., pp. 280-281. See also Franz Kiihn: Der sogenannte "Siidantillen Bogen" 

 und seine Beziehungen, Zeiischr. Gesell. fiir Erdkunde zu Berlin, 1920, pp. 249-262. 



