18 JOURNAL OF SCIENCE. 
problem, I think I am safe in saying that the main structure of 
the country is tolerably well known, especially in those points 
which alone concern us here, and which I will briefly mention. 
The main range forming the New Zealand Alps in the South 
Island, and the mountains stretching from Wellington towards 
the East Cape in the North Island is composed of highly- 
inclined sedimentary rocks belonging to four, and perhaps five, 
distinct systems. The first is probably Archean or Cambrian. 
According to Dr. Hector the second is Ordovician, the third 
Silurian and Lower Devonian, the fourth Upper Devonian and 
Lower Carboniferous, while the fifth ranges from Permian to 
Jurassic. This last system contains fossils related to those from 
the Gondwana system of India and the newer Carbonaceous sys- 
tem of Eastern Australia. According to Mr. S. H. Cox, it is 
about 21,000 feet in thickness, and is entirely a littoral forma- 
tion, plant remains being found all through it ; thus implying a 
subsidence of 3500 fathoms in early mesozoic times. The axis 
of the geanticlinal, however, is not in the centre of the range, 
but lies along its western base, the whole western portion of the 
elevated mass having been removed by denudation, except in 
the west part of Nelson and the north part of Auckland. Of 
the rest all that remains is the submarine plateau which stretches 
out towards Australia. 
The next system of rocks is of cretaceous, probably upper 
cretaceous, age.* Along the eastern base of the main range it 
lies quite uncomformably on the jurassic and older rocks, and 
according to Dr. Hector and Dr. von Haast it is also found in a 
similar position on the west coast of the South Island: thus 
lying at a low level on the geanticlinal axis. In the North Island 
the geanticlinal axis is covered by thick masses of tertiary seci- 
mentary and volcanic rocks, which hide the cretaceous system 
if it exists there. Evidently a great upheaval, followed by enor- 
mous denudation, must have taken place immediately before 
the deposition of this last rock system, that is at the close of the 
jurassic and commencement of the cretaceous periods. There 
may be some doubt as to the exact time of this upheaval, 
but that the New Zealand Alps were principally formed during 
the periods mentioned is unquestionable. 
_ The cretaceous, or according to Dr. Hector the cretaceo-ter- 
tiary system has also been much disturbed in places, and is 
everywhere denuded, and generally overlaid uncomformably by 
beds of oligocene and miocene age. This proves that a second 
elevation, probably of less extent than the first, took place in the 
eocene period, and was followed by a second depression in the 
oligocene The oligocene and miocene marine rocks are largely 
developed, and extend to a height of 2500 feet above the sea,+ 
proving conclusively that during this period New Zealand was 
* Dr. Hector considers the oldest beds to be the equivalent of the Lower Green- 
sand of England. 
+ Acccording’to Dr. von Haast they ascend to 5000 feet above the sea, but no 
-ocalities are given,—‘‘ Geol. of Canterbury and Westland ” (1879), p. 305. 
