290 Transactions. 



as they are traceable from 2,250 ft., whicli is the height of the Titio- 

 kura Saddle, to 1,000 ft. at the Mohaka Bridge, where the same kind of 

 rocks appear as in the case of the nodular limestone near Pohui, the Miocene 

 beds varying somewhat in character as the long hill from Mohaka to the 

 top of Turanga-kuma (2,625 ft.) is reached. Here, at what is known as the 

 Te Kooti Track, the Miocene beds are seen resting unconformably upon 

 the Maitai slates, and from this place onward the slates and sandstones are 

 the prevailing rocks as far as Tarawera. 



A mile or two on the Napier side of Tarawera intrusive volcanic rocks 

 are met with in several places. Up the Waipunga Valley intrusive rocks 

 are common, and six miles beyond Tarawera rhyolites constitute the only 

 rock by the roadside, and these continue for many miles in the direction of 

 the Rangitaiki Hotel, or, rather, they disappear near the 68th milestone, 

 where the swamp-area begins. 



Bunanga is at the 65th milestone. A mile or so from this place is a high 

 hill, 3,200 ft. high, known as Otumakioi. It has a trig, station on the top, 

 and there the sandstones appear very similar in appearance to the Permian 

 sandstone of England. It seems to be connected with the Maitai slates, 

 as these were exposed in one or two places on the hillside. The coimtry, 

 however, is so bush-clad that climbing becomes a difficult matter. 



Immediately opposite Otumakioi, but to the north-east, is another hill 

 or moimtain, Piki-o-hiko-wera, which is composed entirely of volcanic 

 rocks. From Runanga all the exposed rocks, Avhether on the roadside, in 

 the bed of the streams, or forming the ranges that run to the north-west and 

 north, are volcanic lavas, mainly trachytes and rhyolites. A mile or two 

 along the valley that extends from Runanga towards the plateau extensive 

 washings have taken place, and pumice terraces with sloping sides leading 

 into the valleys make their appearance. This country of late years has 

 been occupied as a cattle and sheep run, and the owner, in order to drain a 

 large swamp-area that is the true watershed between the Mohaka and 

 Rangitaiki Rivers, had a trench dug, so as to drain the water into the Wai- 

 punga Stream by wa}- of a smaller stream that passes the roadman's house 

 at Runanga. This drain was originally made about 4 ft. in depth and 

 2 ft. wide, but the breaking into the pumice has resulted in the formation 

 of a huge gorgelike area nearly three-quarters of a mile long, 60 ft. or more 

 wide, and very deep. The removal of the surface of rushes and Sphagnum 

 has resulted in the washing-out of a gulch that can hardly be understood 

 without inspection. The slightest increase in the rainfall causes the removal 

 of great quantities of pumice pebbles, which fill up the entire area of what 

 was at one time in the history of the district an extensive crater, the walls 

 of which can be distinctly read. 



In several places are volcanic hills or mounds, without craters, resembling 

 similar structures such as may be seen to-day in the district where volcanic 

 phenomena are active, particularly on the west of Ngauruhoc and the north- 

 west of Ruapehu. This swamp extends for a number of miles, and to get 

 to the Rangitaiki it is necessary to pass over the ridge or southern crater- 

 wall, from which there is a gradual descent of about 200 ft. in a distance 

 of two miles. 



The Rangitaiki River basin is separated from the Mohaka basin by a 

 range of hills, except towards the north-west, where a small stream from 

 the swamp also drains into the Rangitaiki. A study of the surrounding 

 country between the 73rd and 83rd milestones leads to the opinion that 



