564 Transactions.— Geology. 
rocks than of the upper silurian rocks of Europe, and the few remains of 
organic life yet discovered being of vegetable origin, may it not be possible 
that here we have the representatives of the carboniferous rocks? If this 
be the case, it is to be regretted that the coal seams appear to be absent. 
On the other side, however, it may be argued that it is unusual, and, as 
far as I am aware, unknown, to find the rocks of the carboniferous period 
contorted and folded so that the position of the strata is practically vertical; 
but, in New Zealand we have, on the east coast of Wellington, rocks of 
much later date—upper mesozoic, or cretaceo-tertiary—with their strata 
standing vertical. 
A few fossils would resolve our doubts. One thing is certain, which is 
the extreme irregularity of deposition of these rocks. 
As to what I have above remarked on the matter of folding of the 
strata, it is, I suppose, generally held that, during the paleozoic period there 
was a great shrinking of the crust of the earth, from the results of secular 
cooling, which produced the result of great fracture and folding of the 
strata of the crust. It may,I think, be taken as a general rule that the 
folding of the strata of the paleozoic rocks of the age of silurian, and 
beneath, is far greater than can be found in rocks above that age. The 
Superior rocks are fractured and faulted, but seldom folded to the same 
extent. 
May not another theory be adduced? If rocks are formed ata great 
depth in the ocean bed, say from 2,500 to 8,000 fathoms, forming in the 
eurve between two continents an inverted arch ; and the sea-bottom is 
gradually raised from this great depth to higher than the ocean level: will 
not this movement fully account for the fractures and folding, without the 
necessity of calling in the theory of shrinking ? No doubt the arch may be 
one of small curve, but rocks must have room to expand under pressure, 
otherwise they must break, and, if the lateral pressure is very great, they 
must fold also. 
I have seen fossils in the Museum from rocks of a somewhat similar litho- 
logical character to those above described, from the Wairoa, at Nelson, and 
from the Nuggets, in Otago. These rocks may belong to the same series, in 
which case, being of triassic age, our supposed upper palæozoic rocks would 
of course prove to be triassie also; but a lithological resemblance is not a 
positive proof, but only an inference, and supposing the triassic age of the 
series to be proved, we still have the remarkable fact of the non-discovery 
of fossils in the great mountain ranges in both islands, composed of these 
rocks, for the Wairoa and the Nuggets are, at the best, only outlyers. 
Therefore, the reason why fossils are not found in these mountain ranges is 
still a question for argument. 
