BY H 



JENSEN. 



509 



Brazil, the South Atlantic, the Canaries, Algeria, Tunis, Abys- 

 sinia and Ethiopia, Arabia and Socotra, Sumatra and Celebes. 

 The southern coast of Gondwana-land is represented by the 

 alkaline outposts of the Transvaal, Kerguelen Island, Regatta 

 Point, Tasmania, and Mount Macedon in Victoria. Several 

 alkaline areas occur also in the heart of Africa, in Bourbon, and 

 the Seychelles, areas which lie well within the Gondwana 

 continent. 



The Angara continent (the Mongolian Shield) is likewise 

 fringed with alkaline rocks, and some alkaline rocks occur in the 

 heart of it. 



■* HOML. tlSOTEU 



Fig. 7. — Map of the World showing Distribution of the younger 

 Mountain-Chains (after Neumayr). 



The North American Shield likewise has a border zone of 

 alkaline intrusions. The North Atlantic, which then was a con- 

 tinental mass, is teeming with alkaline areas, e.g., Iceland, Rockall 

 Island, parts of the Hebrides and of Wales, the Azores, and 

 numerous occurrences in the United States. 



The Scandinavian Shield, the Bohemian horst, the massive of 

 Central France, the Yosges and the table Jura, then islands, are 

 also alkaline areas. The area covered by the great Carboniferous 

 Mediterranean, is, however, generally avoided by alkaline rocks, 

 which are not known in the Alps, the Himalayas, or in Further 

 India, nor to any extent in the great Pacific basin. 



