26 FOYE. 



at the fork of the Xavua and Wainikoro-iUna rivers and inferred that 

 it was an elevated plain of marls similar to that near the mouth of the 

 Rewa river. On the contrary, the Navua has incised a series of youth- 

 ful valleys in a fairly level plateau of andesitic agglomerates. Near 

 the coast, erosion carved the plateau into mature hills, which were 

 later submerged, forming a delta plain about deeply lateritized hills 

 of andesitic agglomerate. 



The marl series at the mouth of the Rewa which Woolnough con- 

 siders Miocene, because of fossils found in the Suva quarries, is be- 

 lieved, therefore, to be much less extensive than is indicated on his 

 map. 



In the limited portion of central \'iti Levu which was seen, the 

 folded series has a general strike of E. N. E. - S. S. W. as stated by 

 Woolnough. This strike agrees more fully with the structure lines 

 of Suess than with those of Dana or Gregory (Marshall, 1912, p. 3). 



Jensen (1907, p. 49) has described an occurrence of chalcopyrite 

 associated with andesite near Lautoka. It may be useful to state 

 that where chalcopyrite was found by the writer it was associated with 

 the older flows of andesite which flooded the eroded plutonic rocks. 

 The folded series of Viti Levu lies above this andesite, which is much 

 faulted and brecciated. 



GEOLOGICAL HISTORY OF VAXUA LEVU. 



Introduction. 



Because of limited time and unfavorable weather, the writer saw 

 less of Vanua Levu than of Viti Levu. The western part of Vanua 

 Levu was not visited, but it is known to be underlain by sandstones 

 and other sediments, similar to those described in central \'iti Levu 

 (Guppy, 1903). 



# 



Physiography. 



The outline of \'auuu Le\'u is by no means as regular as that of \ iti 

 Levu. The eastern portion of the island is split by a long, narrow l)ay 

 extending inland, to the southwest, for 50 miles. To the eastern 

 peninsula, thus formed, are appended several minor i)eninsulas 



