Land Connections of the African Continent 29 



^here are they now? Sunken to abysmal depths? But then 

 we may as well accept the possibility that the river mouth dis- 

 appeared under the sea. I have just now mentioned, that the 

 Cenomanian seas reached the foot of the Lebombo mountains. 

 It is practically certain that this mountain range proved an ef- 

 fective harrier to the progress of the ocean, and represents the 

 old coastline of Cenomanian times. Incidentally this would mean 

 that the age of the Lebombo mountains is precenomanian. 



Wegener has recently ventured a grand explanation for the 

 existence of the Atlantic Ocean and for the parallelism of its 

 east and west coast. According to this hypothesis the Atlantic 

 Ocean is nothing but a gradually broadening cleft between the 

 great continents. Most of the difficulties of the land-bridge 

 builders w^ould be solved as also most of the objections against 

 them, for Africa and South America were formerly one conti- 

 nent and they have only in geologically recent times been rent 

 asunder. 



One of the supports of the hypothesis is the parallelism of the 

 west coast of Africa with the east coast of South America. 

 However, this supposed parallelism is not established, for if 

 carefully compared it will be found that the two coast-lines will 

 not fit into each other. If the 2000 meter line be taken as the 

 border of the continental shelf, we get a fairly straight north- 

 eastern border of South America which makes a practically right 

 angle with a nearly straight south east coast. The same line 

 along the African coast leaves a big bight along the coast of 

 Nigeria which is indented opposite the mouth of the Niger. The 

 southern border of north west Africa is then an undulating line, 

 ^/hich makes with the undulating western border of South and 

 Central Africa an angle of about 1 1 degrees. In the first place, 

 therefore, neither of the straight borders of South America will 

 comcide with the undulating borders of Africa and secondly, if 

 one of the borders is fitted as near as possible on to the corres- 

 ponding one of the other continent the two other borders will not 

 coincide but form an angle of twenty degrees with one another. 

 An attempt to fit together the 4000 meter lines fails altogether. 



Further support for the hypothesis has been sought in corres- 

 ponding tectonic phenomena and special attention has been drawn 



