Islands and Coral Beefs of Fiji 415 



existence of an extensive plateau with a depth of between 300 and 

 400 fathoms, from which rise all the islands forming the north- 

 eastern extremity of Fiji. The soundings between Ngau and Viti 

 Levu also indicate shallower water to the west of that island than 

 is found either east or south of it. The deep water extends north- 

 westerly in the passage, parallel with Kandavu. Deep water 

 (1,200-1,700 fathoms) is found in the triangle formed by Moala, 

 Totoya, and Matuku, showing the steep slope of Moala, from 

 1,200 fathoms at a distance of six miles, and of Matuku of 

 1,400 fathoms at a distance of five miles. 



" The deep channel passing through the centre of the Koro Sea 

 gradually deepens towards the south until it attains a maximum 

 depth of over 1,400 fathoms east of Nairai and Ngau, becoming 

 shallower towards Viti Levu. The water gradually deepens also in 

 the Kandavu Passage from over 1,100 fathoms north of North 

 Astrolabe Eeef to over 1,900 fathoms south-west of Kandavu. The 

 soundings to the north of Naitamba indicate a ridge with somewhat 

 over 500 fathoms in depth connecting the plateaus on the two sides 

 of Nanulju Passage. There are no soundings showing the depths 

 between the larger clusters composing the Lau or eastern group of 

 Fiji. It would add greatly to our knowledge of the connection of 

 these groups to have lines of soundings connecting the different 

 island clusters of Lau. 



"All the evidence to be gathered in Fiji tends to prove that 

 preceding the present epoch there was an extensive elevation, which 

 lifted the great masses of coralliferous limestone resting upon the 

 flanks of the islands to a considerable height, in some cases as high 

 as 1,000 feet. The base of the limestone masses rests upon volcanic 

 rocks, as can be seen at Suva, at Kambara, at Mango, at Lakemba, 

 at Naitamba, and at Vanua Mbalavu it shows tlie thickness of the 

 elevated reefs to have been over 800 feet. During this period 

 of uplift the physiognomy of the islands of the group must have 

 been greatly changed, and still further modified by the denudation 

 and erosion which have taken place since the elevation of the ancient 

 limestones. It is to the changes brought about by the elevation and 

 the subsequent erosion and denudation that we must look for the 

 causes which have fashioned the steep slopes of the islands and 

 reefs, and not to the growth of the thin crust of corals which thrive 

 upon the reef flats forming the substratum of the modern reef — 

 a substratum which in Fiji may be of volcanic origin or composed of 

 elevated limestone, the sea face of which is the extension of the 

 former land mass and follows its ancient slope, being only slightly 

 modified by the growth of the crust of recent corals found upon it. 



" Similar elevated reefs (probably composed of the same 

 Tertiary limestone as those of Fiji) have been described by Clark 

 at the Loyalty Islands, and also by Chambeyron and Pelatan. 

 Chambeyron gives figures of the elevated terraces of Lifou and 

 ■Ouvea composed of coralliferous limestone, and there is an excellent 

 photograph taken by Pelatan of the elevated coral reefs of Lifou, 

 and reproduced in Bernard's 'Nouvelle Caledonie,' p. 45. While 



