Page:The origin of continents and oceans - Wegener, tr. Skerl - 1924.djvu/73

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GEOLOGICAL ARGUMENTS
49

the Cameroons, on the other hand, the other younger direction of strike—just recognizable on the map—predominates with a direction approximately north and south and parallel to the sinuous coast-line.

We find the same phenomena in Brazil. E. Suess writes: “The map of Eastern Guiana … shows more or less east-west strikes in the ancient rocks of which the area is composed. Also the stratified Palæozoic deposits, which constitute the northern portion of the Amazon basin, follow this trend, and the course of coast from Cayenne towards the mouth of the Amazon is therefore oblique to the strike. … So far as the structure of Brazil is known to-day, it must be assumed that up to Cape San Roque the outline of the continent also crosses the strike of the mountain chains, but from these foothills up to at least near Uruguay the position of the coast becomes defined by the mountain chains.” Here the courses of the rivers also follow in the main the strike direction (R. Amazon on one side, Rio San Franzisco and Parana on the other). It is true that more recent investigations, as shown in the tectonic map of South America given by Keidel (loc. cit.) and reproduced in Fig. 9, indicate the existence of still a third line of strike parallel to the north coast, whereby the relations become somewhat complicated. However, both the other lines of strike are very clearly shown in this map, even if they are not brought right up to the coasts. On account of the considerable rotation which South America must undergo in the reconstruction, the direction of the Amazon becomes distinctly parallel to the upper course of the Niger, so that both these strike directions will coincide with the African. We see in this yet another confirmation of a former direct connection of these continents.

It must be concluded, from palæontological and