1902.] AND ANCIENT GEOGRAPHY. 339 



according to Wollf, 1 they are at least older than Jurassic. This 

 coast range is continued southward across the Straits of Magellan, 

 and forms the southwest and south coast of Terra del Fuego, 

 where similar rocks are found, and here it curves more and more 

 in a west-easterly direction. 



' However, the old and even Mesozoic age of the rocks composing 

 this chain is not generally accepted, and also the identity of the 

 Fuegian rocks with those of Chili has been doubted ; Norden- 

 skjold,' for instance, takes the metamorphic rocks of the outer 

 (western and southern) side of Terra del Fuego for Cretaceous. 



Thus we see that there is considerable uncertainty about the con- 

 figuration and geology of southern South America in the Mesozoic 

 era; but this much seems to be settled, that the Chilean coast 

 range existed as early as the Cretaceous period,* and that the Cor- 

 dilleras in Terra del Fuego were not formed later than in the Cre- 

 tacoeus. It is just this latter chain that continues over S'taten 

 Island, South Georgia, etc., and finally connects with Graham 

 Land ; and if there was connection at any time, it was by this 

 way and in the Cretaceous. 



Further, there is no doubt that at the end of the Cretaceous 

 period large tracts of Patagonia became dry land, and the maximum 

 of land extension falls probably in Eocene times. 



Consequently we have to put the chief connection of the southern 

 parts of South America with Antarctica at the end of the Creta- 

 ceous and in the Eocene. But we are to emphasize here that thus 

 far we have been able only to connect the Chilean coast range 

 with Antarctica. According to von lhering, this connection also 

 comprised old Archiplata (the Brazilian mass) and existed during 



1 Wollf, F. von, in Zeitschr. deutsch. Geolog. Geselhch., Vol. 51, 1899. 



* Geological Map of the Magellan Territories (Svenska Exped. till Magellans- 

 laend. Vol. 1, No. 3, 1899). 



■And possibly earlier. Burckhardt, C. ("Traces geologiques d'un ancien 

 continent Pacifique," in Rev. Mus. de la Plata, Vol. 10, 1900, p. 177 ff), has 

 brought forth some evidence for UV assumption that in Chili, west of the present 

 Cordilleras, which were sea during the Upper Jurassic, there existed a continent, 

 the eastern shoie of which was formed by the Chilean coast range. There is no 

 means, however, of deciding how far this Jurassic continent extended to the 

 west. The Jurassic age of this range, together with the corresponding rocks of 

 Terra del Fuego, etc., is quite likely if Gregory's theory of the tectonic connec- 

 tion with New Zealand is correct; also, the mountains of New Zealand aie said 

 te possess Juiassic age (see above, p. 334). 



