BY W. G. WOOLXOUGH. 481 



evident that the soft tuffs of the iunnediate vicinity must extend 

 a long way to the east. 



Half a mile further south is the town of iSTalaba. Just before 

 reaching the town itself the path leads round a point composed 

 of finely jointed slate. Bedding planes are obscure, but the 

 jointing is highl}- perfect, though somewhat curved and irregular. 



The tributary Just mentioned flows from the general direction 

 of the old rocks described in the first traverse, and indicates that 

 plutonic rocks must exist between the quartzites of Narokoroko- 

 yawa and the slates of ISTalaba. If the line so obtained indicates 

 the axis of the ancient continental area, it will be seen to run 

 approximately east and west. 



To the west the character of the country indicates a continua- 

 tion of the hard ancient-looking tuffs for about two miles south. 

 To the south-east the rocks are mainly soft tuff. After passing 

 the hard rocks just mentioned the country is mainly built of soft 

 tuffs all the way to Natuatuacoko. These form steep but rounded, 

 grass}'- hills. These are intersected here and there by dykes. 



About five miles below Nalaba, at the village of Waibasaga, 

 another group of hot springs occurs. Of these, I was able to 

 visit only one. This rises in a hole in soft alluvial soil with no 

 rock outcrop. The temperature is intermediate between those 

 at Naseuvou, being just too hot to keep one's hand immersed. 

 There is no deposit nor vegetable matter, but gas bubbles rise 

 fairly freely. There is a faint odour of HoS. A cold tributary 

 of the main river flows within fifty yards of the spring. A second 

 spring is situated about half a mile from the first. From native 

 accounts the temperature must be considerably lower than that 

 of the one visited. 



On the day after my arrival at Natuatuacoko I paid a hurried 

 visit to some caves on the other side of the river. I could spend 

 only a very short time there, as the ford was rajDidly becoming- 

 impassable. The caves are situated in a bed of very tuffaceous 

 limestone about 200 feet in thickness. This is covered b}- a bed 

 of fine soapstone-like tuff forming a conical hill with very steep 



