438 A CONTRIBUTION TO THE GEOLOGY OF VITI LEVU, FIJI, 



the level of these soapstone hills gradually rises until an elevation 

 of from 300 to 500 feet is attained. Everywhere that I have 

 examined sections of this formation in the district under con- 

 sideration, I have found the beds to lie almost level, except 

 towards the- western boundary, where, close to the mountains, 

 steeper dips have been observed. In a small creek (Nadirubasaga) 

 between the Nadakuni and Wainiwaqa a dip of 15° to the east 

 was obtained. Above Serea on the Wainimala the dip is E.N.E. 

 at 8°- 



It is quite possible that, in the case of these inclined beds, we 

 are dealing with tuffs derived from the volcanic mountains which 

 lie immediately to the west, and not with true " soapstones." 

 Near Qelidranitaki (south of Serea") this conclusion is rendered 

 probable by the fact that the dipping beds contain fragments of 

 older and finer soapstone up to 4 inches in diameter. 



Viewed from high points in the Medrausucu Range the area 

 occupied by the level-bedded soapstones appears almost perfectly 

 level, and seems to extend in an unbroken plain right away to 

 the east coast of the island. There are, I believe, a number of 

 deep, narrow river valleys east of the Rewa; their positions are, 

 however, uncharted. 



The area is a plain of marine accumulation uplifted with very 

 little disturbance of the bedding. The fact that the track going 

 south from Serea rises by a series of gentle slopes and falls by a 

 series of steep scarps, suggests a gentle northerly dip, but lack 

 of rock exposures and dense tropical jungle prevent direct 

 observation. 



A few isolated points rise above the general level of the plain. 

 It is possible that these may represent the residuals of an older 

 level at an elevation between 700 and 1,000 feet, but data are 

 wanting. 



With the elevation of the soapstone plain the rivers entered 

 upon a canon cycle. The rocks, consisting as they do of alternate 

 relatively hard and soft beds of soapstone, produce a structure 

 favourable to rapid recession of the streams. Even so, the fact 

 that the first trace of a rapid in the Wainibuka is at least 30 



