CHAPTER II. 



ON THE EVIDENCE OF EMERGENCE OR OF UPHEAVAL AT THE 



SEA-BORDERS. 



ONE would have expected that in an island where submarine 

 muds and tuffs are of such common occurrence at the surface, 

 extending from the sea-border to elevations of 2,000 feet and over, 

 upraised coral reefs would be also frequent and extensive. But it 

 is remarkable that the uplifted masses of reef-limestone, so 

 characteristic of the islands of the Lau Group, are here very scantily 

 represented. It is certainly true that the fossiliferous volcanic 

 muds that form the foundations of coral reefs are often exposed at 

 and near the coast ; but the elevated reefs that ought to be found 

 reposing on them are rarely to be observed. 



It is not to be inferred, however, that in a region so remarkable 

 for the great development of reef-formations coral reefs did not 

 then thrive in these localities, but rather that such a long period has 

 elapsed since the emergence of the present sea-border that the 

 upraised coral reefs at and near the coast have long since been in a 

 great part stripped off by the denuding agencies. Notwithstanding 

 this, it is evident that coral reefs could never have been very 

 extensive at the sea-border during the last stages of the emergence ; 

 whilst they do not appear to have existed at all during the early 

 periods of the history of the island. 



In this connection it may be observed that hard compact lime- 

 stones of any kind are rarely to be found, and only in a scanty 

 fashion. The extensive development of dolomites and hard lime- 

 stones, described by Mr. Andrews and others in the valley of the\ 

 Singatoka in Viti Levu, is not a character of Vanua Levu. 

 The foraminiferous and pteropod clays, which exist in the 

 interior and often in the heart of the island, are not overlaid by 

 ancient reef-limestones, but by great masses of volcanic agglomerate 

 and coarse fossiliferous tuffs, the foraminiferous muds in their turn 

 covering the core of massive volcanic rocks. There were no signs 



