4 G 2 Transactions. — Geology. 



Ft. in. 

 water, and had contracted in every direction, showing cracks as 



above described. Tliis black rock continued without any change 



to the furthest point reached, viz., 212 feet from the surface ... 26 6 



212 



At this point, there being no indications of a change, nor any signs of 

 water, I brought my explorations to a close. 



I have arrived at a few conclusions, which I submit with diffidence, yet, 

 as they are based upon evidence carefully noted as the explorations proceeded, 

 it might be unwise to omit them from this paper. In noting these conclu- 

 sions, and such evidence as may be necessary, I shall, for obvious reasons, 

 commence at the earliest eruption and ascend to the latest. 



The lowest lava bed penetrated 26 feet 6 inches, and presented strong 

 indications of having been a submarine eruption. Upon this rock there 

 appears to have been deposited (at d) a substance like Venetian red. This, 

 I think, had been deposited under water. Whilst in this position it had 

 apparently been washed into the numerous joints or seams to the depth of 

 several feet, which I have described as appearing in the upper surface of the 

 lowest lava stream. Upon this red stratum there lay, dipping at an angle of 

 about 45° S., or towards the mountain, 18 inches of a soft sandstone rock of a 

 light yellow colour (c), having a well-defined stratification, as though the 

 formation had been deposited under water. Though this deposit on analysis 

 showed a trace of chloride of sodium, I am inclined to think it was deposited 

 in fresh water, as if a fresh-water lake had been formed in the ancient crater 

 subsequent to its elevation above sea level. I am the more disposed to 

 advance this opinion, because I have been unable to detect any traces of 

 marine shells or plants in this formation, whilst I found in it some extremely 

 beautiful and well-defined impressions of leaves of toetoe (Arundo consjnaia) 

 or of raupo (Typha latifolia). Both these plants love moist ground ; the 

 latter does not grow except in fresh water, either in very wet swamps or 

 around the edges of fresh-water lakes, instances of which may be seen in the 

 crater of Mount St. John and in the ancient crater now known as Lake 

 Takapuna. 



Resting ui)on this sandstone formation I found a deposit of two feet thick of 

 a mud rock, similar in colour to the preceding stratum, but without any 

 appearance of stratification, in which were many cylindrical holes lying more 

 or less in a horizontal or inclined position. 



These holes, of all diameters from half an inch to nine inches, clearly 

 represent the branches and trunks of trees, as if a shower of mud and fine 

 ashes had fallen from the volcano upon a young foi'cst, or (which I think more 

 probable) upon drift wood deposited at this and probably other points in the 



