CHAPTER VI 



:( 



I 



1 



DESCRIPTION OF THE GEOLOGICAL AND GENERAL PHYSICAL 

 FEATURES (continued) 



The Basaltic Plateau of Wainunu.— This table-land 

 extends for a distance of seven miles from the base of the Ndrand- 

 ramea mountains in the heart of the island, where it is elevated 

 i,ioo to 1,200 feet above the sea, to the valley immediately north 

 of the hill of Ulu-i-ndali, where within a short distance of its termi- 

 nation it still retains a height of 700 to 800 feet. Limited on the 

 west by the valley of the Wainunu River and on the east by that 

 of the Yanawai River, its breadth varies usually between four or 

 five miles. It is best seen in profile when viewed from the south- 

 west on the western shores of Wainunu Bay, between Korolevu 

 and Nasawana, when it presents itself to the eye as a table-land, 

 descending with a very gradual slope from the interior towards 

 the coast. From such a point of view the two great basaltic 

 slopes of Seatura and Wainunu may be seen together, the former 

 descending eastward to the Wainunu valley at an angle of 3 or 4 

 degrees, the latter descending at right angles to it to the southward 

 with a similar small gradient of 2 or 3 degrees. 



In the profile of- the island attached to this work the Seatura 

 slope is well shown ; but that of the Wainunu table-land being 

 seen from the south is represented only by a level contour-line 

 at the base of the Ndrandramea mountains. The two great series 

 of basaltic flows, though closely approaching in a direction at right 

 angles to each other, do not come into actual contact, and the 

 intervening space is now occupied by the valley of the Wainunu 

 River. In the accompanying rude outline-sketch of this region, 

 as seen from off the mouth of the Wainunu estuary, the relation 

 of this valley to the two great series of basaltic flows is clearly 



