184 Transactions. — Geology. 



good sections can be studied by the way, more especi- 

 ally along the watercourses, \vhicli generally proceed in the 

 direction of the dip of the beds. The country from the 

 mountains to Puketitiri may be included as forming a part 

 of the range, although the rocks on the range of hills 

 fronting Puketitiri are, speaking geologically, different. The 

 mountains themselves in some places show rocks with a slaty 

 cleavage. These are mixed with a pale-red sandstone of a 

 fairly fine texture, and corresponding to the i-ocks at the top 

 of the Euahine Eange at the back of the Whakararas. They 

 are highly denuded, and since the destruction of the scrub 

 and native grass the high winds have bared them, and now 

 thousands of acres consist of bare rock, which sun and 

 frost and rain break up at a rapid rate — so rapid, in fact, 

 that no growth is at present possible. 



On the top of the highest part of the mountains I was 

 much interested at observing a series of parallel lines of loose 

 rocks arranged irregularly in line as is done by little children 

 when playing with stones. I could only account for their 

 presence by supposing ice-movement from a higher elevation, 

 when the stones are brought down and deposited in irregular 

 lines as morainic debris. Snow does not rest for more than 

 three months in the year upon the mountains, but the falls 

 appear to be heavy at times, and possibly a slight movement 

 of the snow takes place as soon as the sun is sufficiently 

 powerful to act upon it, at a time when the atmospheric 

 changes are most rapid. The ridge that separates the sources 

 of the rivers is quite narrow, and one can imagine the time 

 when the country further westward was open to the east, and 

 when only a single large river flowed from the lands in the 

 direction of Euapehu and Taupo, bringing down great volumes 

 of pumice, shingle, and timber, the latter being the result of 

 the destructive outbursts from the volcanoes in the district. 



The range of hills immediately joining the mountains on 

 the east side is known as the Birch Eange. The Makahu 

 Stream flows between the two, and runs to the north-east 

 to join the Mohaka, that comes further from the westward. 

 These hills may be set down as forming a part of the main 

 range, as they are geologically the same. Denudation, how- 

 ever, has played havoc with them, and they seem as if they 

 had been shattered and shaken and broken at the time when 

 the mountains were in process of elevation. This range is 

 again separated from another hne of hills which forms the 

 northern end of a series of rocks — limestones, sandstones, 

 and other — which are met with along the foot of the entire 

 Euahine Eanges. In some places the rocks are fairly com- 

 pact limestone ; sometimes they are hungry-looking sands, 

 such as are seen topping the slates in different places. 



