484 THE CONTINENTAL OfllGIN OF FIJI, 



antiquity. The second includes Tertiary to Recent formations of 

 volcanic and sedimentary origin. Between these there is an 

 enormous hiatus. 



So far as I have been able to ascertain, rocks characteristic of 

 continental areas have nowhere been met with so far removed 

 from large land masses. It seems probable, nevertheless, that 

 Fiji forms part of an exceedingl}^ ancient continental land mass. 

 An argument against this theory is the fact that great ocean 

 depths are met with between it and the nearest undoubted 

 continental masses to the Avest, Xew Caledonia, and to the south, 

 New Zealand. This difficulty is not, however, insuperable. 

 That it is quite possible for an outlier of a continent to be 

 separated from its parent mass by deep ocean is proved by the 

 case of Madagascar. This island, which is undoubtedly an outlier 

 of South Africa, has been separated from the mainland b}^ exten- 

 sive •' Senkungsfelde '"' which have produced the Mosambique 

 Channel. This channel is quite as deep, though not quite so 

 broad, as the sea which separates Fiji from New Caledonia. 



In the case of Madagascar, however, there is distinct evidence 

 of extensive faulting on both sides of the channel, and again to 

 the eastwards. Such a faulting has not been directly proved in 

 the case of Fiji. 



A considerable thickness of Eocene beds has been dejDosited 

 on the flanks of Madagascar and the opposite coast of Africa. 

 If this series is continuous across the strait, it may ver}'- con- 

 siderably lessen the depth of water. Between Fiji and New 

 Caledonia such deposits would not be likely to occur to any 

 great extent owing to the absence of large land masses from 

 which sediment could be derived. 



The age of the separation of Madagascar from Africa is deter- 

 minable between moderately narrow limits, but this is not at 

 present the case in Fiji. 



The area must probably have been below sea-level during 

 early geological time for the deposition of the material of the 

 quartzites of Nasava and the slates of Nalaba, if these are marine 

 in origin. How long this condition lasted it is impossible to 



