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A TEXTBOOK OF OCEANOGRAPHY 



Two théories hâve been put forward to account for the 

 origin of the continental shelf. According to the first, it is 

 due solely to the denudation of the land ; but if that were the 

 case we should expect the sédiments to exhibit a progressive 

 diminution of size of the component particles as we recède 

 from the land to the open sea. This is, however, by no means 

 the case. 



The second theory accounts for the origin of the continental 

 shelf by ascribing it exclusively to the effects of marine érosion. 



PiG, 2- — The British Isles and the Continental Shelf. 



On this theory we should expect the widest shelf areas to be 

 found where storms and waves are at their maximum. This 

 is not the case, since land breezes prevail off the east coast of 

 North America from the Straits of Belle Isle southwards to 

 Cape Hatteras, where the continental shelf is wide and well 

 marked. 



The British Continental Shelf. — Off the south of Ireland 

 and at the entrance to the English Channel the banks run 

 parallel to one another in a direction roughly from north-east 



