II EVIDENCE OF RECENT EMERGENCE ii 



a few paces removed from it, is displayed in the volcanic tuff of the 

 point bordering the reef-flat on the east side of Nanduri Bay. In 

 the next place there exist at different places in the midst of the 

 mangrove-belt extensive bare mud-flats, sometimes several hundred 

 yards across, which are only covered by the higher tides. These 

 flats are quite bare of mangrove or any other vegetation and are 

 often cracked on the surface and sun-dried and firm to walk upon.^ 

 These naked mud-flats in the midst of the mangrove tracts are 

 peculiar to this part of the coast. Their general level must be 

 between one and two feet above that of the mangrove belt in 

 other parts of the island ; and I infer that a slight upheaval 

 or emergence has led to the death of the mangroves in these 

 situations. 



I know little of the coast between Nanduri Bay and the mouth 

 of the Ndreketi River. At two localities where I landed no 

 elevated reef-formation was observed. Dana referring to the coast 

 opposite Mathuata Island alludes only to the volcanic agglomerates. 

 The low mangrove-bordered coast between the mouths of the 

 Ndreketi and Lekutu rivers was not actually visited by me ; but I 

 traversed the region behind the broad mangrove-belt, and found 

 occasionally in the tuffs and muds exposed in the river-banks 

 marine-shells and foraminiferous tests, indicating an elevation of 

 a few feet. I examined much of the coast between Lekutu and the 

 extremity of the Naivaka peninsula, but came upon no upraised 

 reef-rocks. In the low isthmus, 20 to 30 feet high, which connects 

 this peninsula with the main island only volcanic rocks came under 

 my notice. A palagonitic tufaceous sandstone exposed in the cliffs 

 on the north coast of Naivaka contains a little carbonate of lime, 

 and being probably a submarine deposit it implies an emergence of 

 the sea-border. 



Although I have been able to produce but scanty evidence of 

 uplifted reefs on the north coast of Vanua Levu, it is probable, 

 judging from the heights given in the Admiralty Sailing Directions, 

 that such formations exist in a few of the numerous low islands 

 and islets that front this coast. Some of these islands and islets, 

 which are often not much more than reef-patches largely reclaimed 

 by the mangroves, will be noticed below when considering the 

 question of the extension of the mangrove belts since the survey of 

 Commodore Wilkes in 1840. 



Neither on the south coast of the peninsula of Naivaka nor on 



^ They were described to me as dry for a fortnight at a time. I was pre 

 vented from making more than an occasional visit to them. 



