448 PROCEEDINGS OF SECTION E. 



3. Samoa itS entirely separate from this ridge. 



4. There is no indication in the soundings that the different 



island gi'oups further east are connected by submarine 

 ridges. 



5. The Tonga-Kermadec trench is almost continuous at a 



depth of 4,000 fathoms from Samoa to East Cape of 

 New Zealand. 



The main period of mountain formation in New Zealand was in 

 the late Jurassic and was possibly contemporaneous with rock folding 

 in New Caledonia, but preceded the movements in the New Hebrides. 



This great elevation was succeeded by a prolonged Miocene 

 depression, but was followed by another elevation. 



The coast line shows evidence of subsidence, but this has been 

 succeeded by renewed elevation. 



In the New Hebrides the elevation has been continuous since the 

 Miocene, and the same is true of Fiji. 



At Tonga, Nieue, and Mangaia, tliere have been upward move- 

 ments in the latest geological times. 



The occurrence of atolls in various places must be regarded as 

 evidence of subsidence, or at least of no elevation. 



The New Zealand coasts are not determined by fault planes, but 

 their main directions are at least as old as the Miocene period. 



Much of the New Zealand coast line is of the Atlantic type. 



The occurrence of alkaline rockis in mid-Pacific goes far to 

 negative the idea that alkaline eruptives are associated with the 

 occurrence of the Atlantic coast type. 



The formation of the Tonga-Kermadec trench may be an effect of 

 normal folding. 



There is nothing in the geology of this area to suggest that any 

 of the oceanic basins have been formed by sudden subsidence. 



Except for the Triassic fossils of New Caledonia and New 

 Zealand, and, perhaps, in the Cainozoic mollusca of Australia and 

 New Zealand, there is no paloeontological evidence to suggest that 

 any of the lands now separated were formerly united. 



The rocks both volcanic and sedimentary fail to suggest any 

 previous connection between lands now separated unless the occun'ence 

 of large masses of ultra-basic rocks in New Caledonia and New 

 Zealand may be regarded in this light. 



BIBLIOGRAPHY. 



The following are among the more important of the works that 

 should be consulted on this subject : — 



Barnaed, a. — LArchipel de la Nouvelle Caledonie. (Hachette ©t 

 Cie, 1895.) 



Bastian, a. — Inselgruppen in Oceanien, Berlin, 1883. 



Dana, J. D.- — Corals and Coral Islands. (Sampson Low, 1875.) 



— Characteristics of Volcanoes. (Sampson Low, 1890.) 



— Geology of U.S. Exploring Expedition. 



