ix THE N AW AVI RANGE 135 



expect to find where there has been emergence rather than 

 upheaval. 



Siliceous concretions and silicified coral fragments, so character- 

 istic of the surface of some of these plains of Vanua Levu, did not 

 frequently come under my notice here. They, however, occur 

 occasionally, as in the district between Nanduri and Natua. 



The Nawavi Range. 



With this remarkable coast range, which fronts the Mathuata 

 sea-border for a distance of 12 or 13 miles between Ravi-ravi 

 Point and Nanduri, I have unfortunately but scant acquaintance. 

 It attains its maximum elevation in Mount Nawavi of 2,238 feet, 

 and is described by Mr. J. P. Thomson, 1 who surveyed this coast, 

 as broken in two nearly opposite Niurua, the pyramidal mountain 

 of Koro Navuta rising in the gap Various other peaks, besides 

 that of Nawavi, are marked in the latest Admiralty chart ; they 

 vary in height from 1,000 to 1,700 feet. As this range lies only a 

 mile or less back from the beach, it gives to the sea-border a bold 

 and often precipitous appearance, which is well shown in an 

 illustration in Wilkes' Narrative of the United States Exploring 

 Expedition (iii. 226). 



Basic rocks probably prevail in this range. When I ascended 

 its eastern spurs from Nanduri, and reached a height of 800 feet, 

 only basic tuffs and agglomerates came under my notice. From 

 Dana's remarks 2 it is to be inferred that the " frowning bluffs" 

 opposite Mathuata Island are of similar formation ; and it would 

 seem that the rugged black stones, described in the Admiralty 

 Sailing Directions 3 as topping the hills behind Ravi-ravi Point, 

 are of the same basic character. From its contour and profile I 

 would gather that, as in the great mountainous ridges that 

 constitute the backbone of the island between Va Lili and Mount 

 Thurston, palagonitic tuffs and clays of submarine origin will, 

 together with volcanic agglomerates, be found far up the slopes of 

 this range, and that the axis will prove to be largely composed of 

 massive basic rocks. 



The hot springs referred to by Thomson and others as 

 occurring at the foot of the north and south slopes, namely at 



1 Proceedings, Queensland Branch, Geographical Society of Australasia, 

 Brisbane, 1886, vol. i. 



2 Geology of the United States Exploring Expedition. 



3 Pacific Islands, vol. ii. 1900. 



