20 
Geology and Physical Geography; 
At Yanakio landing, on the western shore of Corner Inlet, the 
granite contains small garnets, and from the granitic detritus in 
the same locality zircon, topaz, green and blue sapphire, and a 
small ruby were obtained by Mr. W. Miller, manager of Yanakie 
Station, and examined by Professor Ulrich, who also enumerates, 
among accessory minerals occurring in Victorian granite, tin ore , 
epidote , chlorite , fluor spar , and amethyst , at Beechworth and 
Chilteru ; col nm bite, at Maldon ; molybdenite, at Yaekandandah, 
Maldon, and Moliagul ; iron-glance, at Mount Korong; and iron 
pyrites , generally distributed. The granites of various localities, 
as Harconrt, Gellibrand’s Hill, Gong Gong, near Ballarat, &c., 
afford good durable building stones, and are also valuable for 
monumental purposes. A very beautiful syenite granite, composed 
of red felspar, quartz, and hornblende, occurs at Gabo Island, 
and has been used in the General Post Office, the Custom House, 
and the Australasian Insurance Company’s office, in Melbourne. 
The typical Older Plutonic granite and kindred rocks unques- 
tionably occupy the lowest stratigraphical position, and constitute 
here, as they probably do throughout the world, tho prevailing 
rock foundation. Their appearance at the surface is evidently due 
to the removal, by denudation, of once superincumbent sedimentary 
strata. Geologically, however, these older hypogeno rocks are 
younger than the Palmozoic strata of Silurian age, but older 
than those classed as Upper Palaeozoic. The grounds for this 
opinion are, that whereas the Upper Palaeozoic rocks, where found 
resting on the granite, arc unaltered, and their granite foundation 
appears to have been as we' now see it at the time of their 
deposition, the Lower Palaeozoic rocks are invariably more or 
less metamorphosed near their contact with, and frequently 
contain injected veins of, the granite, showing that since their 
deposition the granite has been in a heated and plastic, or possibly 
a molten, condition. (Fig. 3.) 
Another marked feature is that the granite intrusions do not 
appear to be connected with the folding process to which tho 
Silurian rocks have been subjected, 
and to which is due tho normal high 
rate of inclination of their layers. 
That process would appear to have 
taken place prior to the invasion of 
the sedimentary strata by igneous 
masses, as we find in many cases 
that the strike of Silurian strata 
abuts directly on the granite, and in 
others that the dip of the strata is 
against, instead of with, the surface 
slope of the granite. Evidences 
of the intrusive character of the 
granite to a certain extent are, how- 
ever, visible in many places, in the 
Tig. 3. 
Sketch-section illustrating re- 
lations of Granite, Silurian, 
and Upper Devonian rocks, 
Mount Hump Creek, branch 
of Avon River. 
Branch of Mount Hump Creek. 
