GEOLOGICAL OBSERVATIONS IN FIJI. 37 



lain by limestone, and later uplifted. The river, draining the interior, 

 has been extended across the elevated reef limestones. On either side 

 of the bay at its mouth continuous areas of uplifted limestone stretch 

 for half a mile along the coast. 



The sketch (Figure 16) illustrates the type of topography near 

 Xandi. The limestone is nearly 40 feet in thickness and dips 3° 

 to 4° S. E. The rocks underlying the limestone are given in the 

 columnar section (Figure 17). 



The section indicates that here andesite was erupted during the 

 deposition of the limestone and the other conformable sediments. 

 Farther east no andesite of this relatively late date has been dis- 

 covered, all the andesites observed being unconformable below the 

 limestone. 



TAVIUNI. 



The island of Taviuni with its reefs is shown in the sketch map, 

 (Figure IS). Three periods are definitely indicated in the history of 

 the island. They are most easily recognized in its northwestern part, 

 where maturely eroded andesites are surmounted by a number of 

 recent cones, from which basaltic lavas have spread north and east 

 over the adjacent country. 



Along the central and northern borders of the island there is an 

 irregular bench, probably cut by wave-action, on the mature and 

 deeply lateritized hills. The bench stands at an elevation of 75 to 

 150 feet and from it rather abrupt slopes descend to sea level. 



Near the west-central coast of the island, recent basalt flows lie 

 within a valley carved below this bench level. The order of events 

 which gave rise to the valley incised in the bench is not clear. The 

 maturely eroded andesites may have been submerged, a bench cut, 

 and later elevated; or the bench may have been cut during a pause 

 in the general uplift of the island. 



A continuous northeast-southwest ridge, bearing some of the 

 highest peaks of Fiji, runs through the middle of Taviuni. Near the 

 very center of the island is an old crater whose flat floor is occupied 

 by a shrinking lake. The floor is a mile wide and two or three miles 

 long. It is dotted with two or more small hills which rise from the 

 lake. The crater is rimmed with precipitous cliffs, 200 to 300 feet 

 in height. One of the streams flowing towards the eastern side of the 

 island is said by settlers to breach these cliffs. 



