CHAPTER XIV 



THE ISLAND BEACHES 



(A) The Seaward Beaches. 



As the barrier varies in different parts of tlie atoll ring, so does 

 the beach which rises from it, and so too do the trivial elevations 

 that may be dignified by the name of the " coast-line " of the 

 islands. This is but the natural outcome of the fact that 

 the different aspects of the circle are exposed to different 

 physical conditions. The physical forces that build the dry 

 land are not uniformly distributed around the atoll, and the 

 natural consequence is that the disposition of the land varies 

 as its creative forces vary. Were we to have an accurate 

 model of any atoll, we could tell from its examination Avhich 

 was its windward side and which its leeward, which were the 

 islands exposed to the ocean's currents, and which were those 

 protected from their scour. Since the building processes at 

 work on the seaward side of the islands are different from those 

 which shape the lagoon shore, it is but natural that the sea 

 beaches and the lagoon beaches should differ in their nature. 

 The ocean beaches consist essentially of a sloping pile of coral 

 debris piled up on the breccia stratum as a basis ; they form 

 the merging-line of the island dry land and the barrier 

 flats. 



On the ocean side there are places where no beaches can 

 be said to exist, for the island rises abruptly from the barrier 

 flats. In such places a succession of miniature terraces, 

 two or three in number, rise as steps of consolidated breccia 

 and bear on their top step the steeply piled up boulders that 

 make the shore-line of the island. In other places there has 

 been a denudation of the island land, and the tide-washed flats, 



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