GEOLOGICAL OBSERVATIONS IN FIJI. 



71 



surface of the island could alone represent the Pleistocene platform, 

 for only minor benches are found about the edge of the island above 

 sea-level. If the island represents an atoll which developed on a 

 Pleistocene bench, the bench must be above sea-level according to the 

 Glacial-control theory. In this case the Recent atoll nmst be assumed 

 to have completely welded itself upon an older limestone mass; for 

 no evidence of unconformity was found. 



Ongea (Figure 34). 



Ongea differs from Wangava in representing a later stage in the 

 dismemberment of an elevated mass of coralliferous limestone. Two 



Figure 34. Sketch Map and Profile of Ongea. 



islands lie within the lagoon of Ongea. The southern one, Ongea 

 Ndriti, was not visited. Ongea Levu has a wide, fingering bay indent- 

 ing its southern side, which is transformed into a sand flat at low tide. 



