452 A CONTRIBUTION TO THE GEOLOGY OF VITI LEVU, FIJI, 



volcanic material running in that direction. The hills to the 

 south were not visited; those to the north are more basaltic in 

 character than the ranges to the east. 



Summary of Section v, — The Waiqa Valley runs east 

 and west for about twelve miles. Considering the size of the 

 stream, it is a very broad and open valley. The rocks exposed 

 are mostly crystalline (granites and schists), but towards the 

 eastern end a remarkable hypersthene rock, with characters 

 linking it to the more acid charnockites, occurs. 



vi. — Naviia- Wainikoroiluva Valley. 



The Navua System is analogous to the Rewa System in that 

 both main rivers keep close to the eastern side of their basins, 

 and draw their waters from wide stretches of country to the west. 

 In both cases there are no important affluents coming in from 

 the east, while very large tributaries enter the right hand bank. 

 This statement is true only if we regard the Wainikoroiluva as 

 the main branch of the Navua System, as I believe it is struc- 

 turally, though it is certainly inferior in volume to the Navua. 

 On no map of Fiji which I had seen, prior to my recent visit, was 

 the largest stream of the system shown correctly. The informa- 

 tion with regard to this portion of the country was supplied by 

 Mr. C. A. Holmes, L.S., Government Surveyor, with the kind 

 permission of His Excellency, Sir Everard im Thurn, and is 

 detailed and accurate. 



The structure of the Navua System resembles that of the Rewa 

 in another important particular; the streams in their lower 

 courses are intrenched in a dissected plateau, occupying narrow 

 canons about 300 feet in depth. The general surface of the 

 plateau is strikingly level, more so than that of the Rewa; from 

 high points in the Namosi district it appears as an almost 

 unbroken plain stretching for miles to the westward. The heights 

 which rise above the general level, such as Koqi, Tuvutau, 

 Nabekalevu, etc., are very strongly suggestive of residuals of at 

 least one older peneplain. The eastern limit of the plateau is 

 sharply defined by the western scarp of the range of mountains, 



