92 FOYE. 



Again, if Fulanga were elevated 45 fathoms, the Pleistocene bench, 

 according to the hypothesis, should appear near sea-level and the 

 present lagoon depth of 10 fathoms be explained most logically by 

 recent subsidence. The depth of the Fulanga lagoon corresponds 

 closely to the depths within adjacent modern reefs. Neither 

 Fulanga nor Kambara have any indications of benches, either above 

 or below sea-level, which may be interpreted as Pleistocene, wave- 

 cut platforms. 



If the Glacial-control theory is still adhered to, the atolls must be 

 pre-Pleistocene in age, but Daly considers that atolls and barrier reefs 

 originated specially in post-Pleistocene time and were perhaps rare 

 forms in the pre-Glacial oceans. If these atolls were pre-Glacial, they 

 would easily have been destroyed by Pleistocene wave-cutting. 



There is no evidence that the cycle of the elevated limestones was 

 broken by a period of Pleistocene wave-cutting. The writer believes 

 therefore that, in the older cycle, barrier reefs and atolls originated 

 by the subsidence of eroded, volcanic surfaces. 



The present cycle was initiated by the uplift of the older limestones. 

 During the cycle these limestones have been differentially elevated 

 and their present state of erosion indicates that they were by no means 

 elevated contemporaneously. Vatu Vara is 1030 feet high and 

 remarkably well preserved. Vekai is but 12 feet high and represents 

 the final residual mass of a former island destroyed by atmospheric 

 solution. A close study of the charts leads to the conclusion that 

 the less the erosion of an island, the less is the depth of its surrounding 

 lagoon. This inference holds true in spite of the fact that by progres- 

 sive erosion the lagoons should be filled and is explained by a recent 

 subsidence. 



All of the islands are being rapidly reduced to sea-level by atmos- 

 pheric solution. Sea-level flats dotted by residual masses of limestone 

 should be the ultimate stage of this process. Portions of Fulanga 

 and Ongea present examples of this stage, but such examples are rare. 

 Lagoons dotted by undercut islets, the submerged complements of 

 such flats, are, however, very common. All the recently uplifted 

 islands have no lagoons, or else shallow lagoons. All the eroded 

 islands have lagoons indicating subsidence. Hence still-stand with 

 the production of large solution flats near sea-level is very unco;nmon. 

 The inference follows that uplift is soon followed by subsidence. In 

 this way a new generation of atolls is developed on the eroded and 

 submerged platforms of the older limestone masses. 



Table II presents the facts concerning the size and nuixinuim depth 



