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



met with in situ. It nowhere rises much above the level of the 

 stream, and is capped by rocks of the later volcanic series. It is 

 associated with strongl}^ jointed andesitic rocks. The Wailato is 

 only one of a series of rivers rising in the neighbourhood of 

 Muanivatu; and in the other streams, at all events in the 

 Waivou at Nakoro, and the Wainasa above and below Naduta, 

 similar granitic rocks occur, with the same relationship to stream- 

 development as that noted above. We have, therefore, a wide 

 extent of these older rocks brought to light in this district, at or 

 about the same lev^el as those in the Wainimala, Wainivalau and 

 Waiqa Valleys, and, like them, retarding the vertical corrasion 

 of the rivers. The two sets of exposures are certainly continuous 

 beneath the overlying volcanic series, so that a great area is 

 indicated for the granitic series. 



The slaty rocks of Namoli were inaccessible owing to flood, but 

 the discovery of granite in situ so close to the south-east is an 

 argument in favour of the considerable age of the slaty rocks. 

 The hard, green, jointed tuflfs* south of Waisaf certainly belong 

 to the same series. 



The hot springs at Waibasaga on the Sigatoka, like those of 

 Naseuvou on the Waidina, occur close to what appears to be the 

 edge of the granitic area, or, rather, close to a spot where that 

 area is brought to the surface, possibly by faulting. 



At the town of Nukuilau an interesting and important section 

 occurs. Just west of the town is a small creek in whose bed 

 large boulders of granite occur. It is, however, somewhat 

 doubtful whether granite occurs in situ in the watershed of this 

 creek. A road-cutting close by shows a series of tuffs containing 

 large rounded boulders of granite in abundance, and this may be 

 the immediate source of the boulders in the creek. The granite 

 is relatively more abundant than in the Nasoqo conglomerate, 

 but in the Nukuilau beds fossils do not seem to occur. The 

 section is nevertheless confirmatory of the Nasoqo section as 



' Former paper, p. 480. 

 t Possibly the name of the district and not of the town. 



