14 FOYE. 



The conditions here are very different from those found at the mouth 

 of the Rewa. The latter river drains a volcanic country, and the 

 lateritized clays are swept down in great abundance. The mouth 

 of the river is a wide mud-flat overgrown with mangrove bushes. 

 The Singatoka, on the other hand, drains a region of granites, diorites, 

 and sediments formed from these rocks. The material, transported 

 by the river, is, therefore, less finely pulverized and is not carried far 

 out to sea. It is also less cohesive above the low-tide mark, dries out 

 ciuickly, and is blown by the wind into sand hills. Under such condi- 

 tions corals grow close to the mouth of the Singatoka and, as the sketch 

 shows, the boat passage is very narrow, being kept open only by the 

 scour of the river and tidal currents. 



Figures 3 and 4 indicate the areas of marl and coralliferous limestone 

 forming the upraised coastal plain along the southwestern shore of 

 Viti Levu. The belt is never very wide, varying from a half mile to 

 two miles. At the extreme southwestern point of the island, near the 



Figure 2. Mouth oY the Singatoka River as seen from the Northeast. 



small island of Songo, the deposits cease, and it is important to note 

 that here the fringing reef changes to a barrier reef and sweeps out 

 beyond the volcanic islands of the Malolo Group. 



The depth of water within the Malolo lagoon, back of the reef, 

 gradually increases toward the northwest, from 13 fathoms to 40 and 

 50 fathoms. The character of the reef correspondingly changes. 

 Near the main island it is quite continuous; farther northwest it be- 

 comes more and more patchy and at last disappears entirely. 



At first, one might be tempted to correlate the uplift of the coastal 

 sediments east of Songo with the general subsidence to the west, 

 which has embayed the western coast of Viti Levu, thus regarding 

 these movements as part of a single warp affecting the whole island 

 within recent times. Structural evidence from the western coast of 

 Viti Levu and from the Yasawa islands shows that the formation of 

 the lagoon and the barrier reef caimot be ascribed to a single tilt- 

 ing movement toward the west. 



