207 
xxxii. Wilson, range three miles west of town. 
Macroscopic character s.—Rather coarser in 
grain than xxxii. Very white and intensely hard. Silicifi- 
cation has been so complete that the rock appears almost 
homogeneous. Fracture is conchoidal, and lustre highly 
vitreous. 
Microscopic character s.—Essentialy a me- 
dium-textured mass of interlocking quartz grains. Very 
angular, and show evidence of intense strain. The rock is in 
all respects like that from Sellick’s ШЖК Ip 203), 
and occupies an exactly similar stratigraphical position. 
Sav Metropolitan Brickworks, Black 
wood. 
In the glacial till at this locality erratics of quartzite are 
very numerous. I have examined a considerable number, 
but have found a very surprising uniformity of characters 
amongst them. They are medium in grain, and are very 
dense and hard. In many of them nothing but clear quartz 
can be identified with a lens. In other examples there are 
abundant white specks, strikingly like the felspathic constitu- 
ents of the Mitcham quartzites on casual observation. Closer 
observation shows that these patches are finely granular, and 
have a distinctly greasy lustre. 
Microscopic characters.—Texture is un- 
even, but is not coarse. The most abundant constituent is 
always quartz, in rather rounded grains, almost all of which 
show rejuvenescence. In the densest rocks, those without 
the white spots, this secondary addition of quartz has com- 
pletely filled all the original spaces ; in the other rocks spaces 
have been left. A comparatively few composite grains are 
present, mostly fine-grained schists or granular quartz. 
The patches of white material noted above are seen to 
consist of masses of fibrous material, generally with radial 
arrangement; its optical properties and behaviour with acids 
indieate antigorite. There is nothing to show from what pri- 
mary mineral it has been derived. 
say. Inman Valley. 
A very remarkable rock formation has been found at in- 
tervals from this point on the south to Williamstown on the 
north. In its general appearance and its apparent strati- 
graphical relationships ıt is very strikingly suggestive of a 
repetition of the Cambrian glacial bed. Its characters are 
those of a conglomerate gneiss, though the degree of meta- 
morphism varies very considerably. In the Inman Val- 
ley the boulders which exceed a foot in diameter have been 
much deformed by fiowage. Тһе groundmass is practically 
a coarse-grained mica schist, with well-marked "augen" 
