118 Transactions of the Royal Society of Victoria. 



Plate II., gives roughly the features of these beds. A sample 

 from the bed marked (a), which I examined in a thin slice, 

 I found to be foliated by alternate bands of brown pleochroic 

 mica and quartz in crystalline grains. The interspaces are 

 filled bv a mixture of flakes of brown mica and a lesser 

 number of flakes of muscovite, or else filled by small masses 

 of pinite, with relatively large plates of muscovite. As in 

 other rocks in this section, the brown mica contains, but not 

 in all cases, minute inclusions surrounded by pleochroic 

 halos. In addition there are also grains of orthoclase among 

 the quartz grains. 



A second sample which I examined was from one of the 

 finer-grained beds (6), which, here as elsewhere in this 

 district, alternate with those which are quartzose. I found 

 it to differ from that last described. It has a well-marked 

 foliated structure. The greater part of the slice has, at. one 

 time, been a ground mass of orthoclase felspar, in which 

 were included grains and irregular patches of quartz, thus 

 producing a structure resembling that which is termed 

 *' graphic" in the granites. In the greater part of the slice 

 the felspar has been converted into a colourless or slightly 

 yellow alkali mica, while, in other places, the felspar is still 

 unaltered. This felspar appears to be orthoclase. The areas 

 of felspar and quartz or of mica and quartz are separated 

 by foliations of brown mica with a little muscovite. In 

 places the foliations bulge oiit round small masses of felspar 

 and quartz with a little mica, simulating, on a small scale, 

 the so called " eyes " in some rocks. In some of the felspar 

 areas there are places where the brown mica preponderates, 

 in others, it is the muscovite together with small grains of 

 quartz. A few small crystals of tourmaline are scattered 

 throughout the mass. There are also a few scattered crystals 

 of iron ore, having traces of hexagonal outlines. Aiost of 

 these are in the neighbourhood of the brown mica, of which 

 some individuals have pleochroic halos. 



In this rock the felspar and quartz appear to have 

 crystallised almost simultaneously, forming a ground mass 

 in which are the micas and the iron ores. 



(I.) The schists, which up to this place were much as last 

 described, become here more massive, but with traces ot 

 bedding, and an apparent strike of N. 40° W. They are also 

 traversed by small winding veins of aplite and quartz. 



{m.) The rocks at this place are massive and much jointed, 

 and are traversed by a strong dyke of "graphic granite," 



