9 
IXATJGURAL ADDRESS. 
continent consists in the fact that many of the more elevated summits 
are composed of granite, which is certainly the oldest rock formation 
with which we are acquainted. 
It is here necessary to state that the term “ granite ” is used to 
indicate ancient or continental granite, and that the granitoid rocks, 
which are so closely allied in lithological aspect as to pass under the 
same designation, are really intrusive masses of more recent extrusion, 
even as late as the Permo-Carboniferous period, and will be termed 
“ intrusive granite.” Now the higher portions of the granite ranges 
show no superincumbent strata, while sedimentary beds fold round 
their flanks in a manner which indicates that the edges of these strata 
were formed near the margin of an ancient sea, above which the more 
elevated masses of granite rose as islands. As an instance of this 
early existence of land we find on the present east coast that the 
granite tract of New England is Hanked by Devonian slates and 
marine beds of spirifer limestones, in positions which indicate that 
their deposition was in an ocean of at least 2,000 feet in depth, above 
which the granite mountains rose to an elevation of 2,000 feet. 
Adopting similar evidence as a basis for the estimation of the area of 
land at this earlier date, it appears that there existed a chain of islands 
extending from Tasmania northerly, along the line of the present great 
dividing range, between the eastern and western streams, nearly to 
Cape York, a distance of abont 2,000 miles, and with a breadth seldom 
exceeding 100 miles. In 'Western Australia a much broader area of 
dry land existed, in the form of a granite tableland, the western limit 
of which, commencing at Cape Leenwin, extended north for 600 miles, 
with a straight coast line rising 500 feet to 1,000 feet above the 
ocean. This land had a breadth east and west of about 200 miles, but 
its eastern shores were comparatively low and irregular, with probably 
detached insular portions, more especially on the northern side, as the 
stratified rocks in which the West Australian gold mines are worked 
have an exceedingly irregular outline where they overlay the granite. 
Between these eastern islands and the western land, there probably 
existed some granite peaks which rose above the ocean, but the evidence 
is that they were not of important area, and principally located in the 
northern parts. The remainder of the present continent was covered 
bv an ocean gradually increasing in depth from the western land to 
the central part, and great depths continued to the shores of the 
eastern islands. 
SEDIMENTARY DEPOSITS. 
The next step in our history is that the natural decomposition of 
the granite, both terrestrial and marine, supplied material for sedi- 
mentary deposits ; and we find a series of imperfectly stratified grit 
stones, together with schists and slates, the former the results of the 
deposition of the coarser drifts, and the latter the more gradual 
deposit of the finer particles. These rocks, which are classed as 
