6 
3. True quartz veins in the sandstones have been noted only close to 
the contact of granodiorite or porphyry. 
4. No conglomerate containing granitic boulders, or quartz derived 
from granitic rocks, was found at the base of the sandstones. 
where they rest directly on granodiorite. 
Good junctions between the sandstones and porphyry were examined at 
Stony Creek and at the falls, McKenzie Creek; and the contact of the 
granodiorite and sandstone was inspected at Wartook, Stony Creek, and 
Mount William goldfield. An area of granitic rock at Chimney Gap has been 
viewed, but not examined. 
Wartoolc .—From the Wartook Reservoir an unused bush road extends 
to Rosebrook Station; on it, about 3 miles from the caretaker's cottage, 
there is a contact between granodiorite and Grampian sandstones. The 
latter are somewhat abnormal; some are silicified, but quartzite here is not 
a prominent feature. In the sandstones are bunches of quartz crystals and 
veins of quartz, and an old shaft on the road has been sunk on a quartz vein 
which is said to have contained gold. True quartz veins are very rare in the 
Grampian sandstones, though small, siliceous pipes and veins are plentiful 
in some parts. In the sandstones there also occur irregular veins of specular 
iron ore, and a porphyrytic dyke, which was traced close to the contact of the 
granite rock ; a similar dyke was observed in the granodiorite at its junction 
with the sandstones. 
Stony Creek .—On the north and east sides of the granodiorite, the sand¬ 
stones have been altered to very vitreous, brittle, and shattered quartzites, 
which stand out like a wall. The actual contact here is unfortunately 
obscured by alluvium. A considerable amount of gold has been obtained 
at, and near, this portion of the contact. 
Mount William Goldfield .—There is a larger area of granodiorite exposed 
at Mount William than at Stony Creek. On the eastern boundary, the 
Coronation tunnel, which has been driven westerly into Sugarloaf Hill, at 
first intersects sandstones and then continues for a considerable distance in 
granodiorite. The contact of the two rocks is not as clear as could be desired, 
since there has been a considerable amount of crushing, but the granodiorite 
here certainly appears to alter the sandstones and to throw off small dykes 
into them. 
In the same district but nearer Mafeking, there is a large area of quartzite 
on the saddle at the head of the Mount William or LittleWimmera Creek. 
It should be mentioned that only in one locality (the Saddle, Mafeking) 
were quartzites found at more than half a mile from a granitic outcrop, and 
in this instance, it is not known at what depth below the surface the igneous 
rock may exist. # 
From my own observation, and from inquiries, it appears that quartzites- 
are rare in the Grampians, and it seems very likely that where found they are 
the result of contact metamorphism of igneous rocks. 
Other Igneous Rocks. —Along the mining track from Hall’s Gap to the 
t k^ony Cieek, the^ e are several outcrops of porphyry. These 
appear to have been thrust into sandstones, generally along the bedding 
planes, and in places the last inch or so of the sandstone adjoining the 
porphyry has been altered to a more or less vitreous quartzite. 
on the face of Mount Rosea, the sandstone beds are 
diagonally intersected by a decomposed porphyry dyke which occurs in a 
strong fault, and apparently slightly indurates the sandstones. 
