REPORT OF THE DIRECTOR ig20-21 95 



as Suess has unfolded so masterfully, a large part of the successive 

 waves of folds (the Altaides) which have overrun Asia. The older 

 vertex has, according to Suess, probably never been occupied again 

 by the sea, in its central parts, but has been widely transgressed by 

 the Cambrian along the margin. The trend lines of the folds of the 

 Sinian basement complex in China, which are buried under unfolded 

 Cambrian, seem to us to demonstrate that also this immense complex 

 is a southeastern continuation of the Asiatic nucleus. 



The Precambrian trend lines are traced by Suess to the lower 

 Amur and the Pacific coast, southward to the Gobi desert and 

 southwest to the Changai, with hardly any deviations from the 

 two general directions. 



The ancient continent whose existence in the north of Asia is 

 demonstrated by this Precambrian basement complex and which 

 has continued as the nucleus of Asia almost uninterruptedly to the 

 present time, is the Angaraland of Suess. It corresponds to Lau- 

 rentia, the ancient ancestor of North America. 



In central Asia the thick deposits of the Tethys, the great Medi- 

 terranean sea of Paleozoic and Mesozoic times, now thrown into 

 gigantic fold systems, effectively hide the basement complex, and 

 certainly in India and probably also in Cambodia, where again 

 Precambrian complexes appear on the surface, different trend lines 

 from those of the Asiatic nucleus prevail (see posted). 



India was recognized by Suess as an entirely foreign element of 

 Asia belonging to ancient Gondwana-land and thereby to a different 

 continental crust segment, while Cambodia probably belongs to 

 Aequinoctia, an old Paleozoic continent lately distinguished by 

 Abendanon (see posted). As Suess has stated, the modern Asia 

 consists of different elements, ancient Angaraland, the Sinian block, 

 the ancient Tethys bottom, and the Indian block left of Gondwana- 

 land. 



Tracing the Precambrian rocks westward from the ancient vertex 

 Suess found that the Altai mountains, which later formed a new 

 vertex, were themselves originally a part of the Sayan section of 

 the ancient vertex. Along the north coast of Siberia, west of the 

 Taimyr island, extensive areas of gneiss and mica schists have been 

 observed by Nordenskjold (see Suess, v. 3 pt 2, p. 376) and at 

 Cape Tscheljuskin he observed schists striking west-northwest-east- 

 southeast, suggesting the Sayan system. 



By means of the trend lines of the Ural mountains, which is a 

 posthumous fold system of the Sayan system of folds of the Asiatic 

 vertex produced by pressure from the east, and the adjoining Timan 



