500 



THE COXTINEXTAL ORIGIN OF FIJI. 



By W. G. Woolnough, B.Sc, F.G.S. 



Part II. 



Petrographical Descriptions of Typical Rocks. 



(Plates xxxv.-xxxvi.) 



Synopsis. 



PAGE 



Granite (Xarokorokoyawa) ... ... ... ... 501 



Quartz Diorite (Nadranikula, Wainibua) ... ... 506 



Diorite (Navua River at Nakorowaiwai) ... ... 510 



Quartzite (Togieedra) ... ... ... ... ... 514 



Augite Andesite (Namulowai) .. ... ... ... 515 



Pyroxene Andesite (Voma, Upper Waidina River) ... 520 



Hornblende Andesite (Buki Levu) 525 



Hornblende Andesite (Korobasabasaga)... ... . . 5*29 



Olivine-bearing Andesite (Tama ni Ivi, Mt. Victoria) 533 



Porphyritie Basalt (Nadarivatu) .. . . ... ... 536 



In the first part of this paper a sketch of the geological structure 

 of Yiti Levu has been given, and reasons advanced to prove the 

 theory that this portion of the Fiji Group is not a typical oceanic 

 island, but a remnant of the great Australian-Papuan Continent 

 which in former geological time must have had a considerable 

 extension to the eastwards of its present boundaries. 



In this portion of the paper certain of the rocks collected are 

 petrographically described in considerable detail. I have de- 

 scribed thus only a very small part of my collections, l)ut I have 

 selected those rocks which are typical. I very much regret that 

 the work must be regarded as incomplete from the absence of 

 chemical analyses. I have been so situated that I have been 

 unable to make these myself, or to have them made for me. The 



