102 Transactions of the Royal Society of Victoria. 



of the granites into the tracts of schist, in promontory-like 

 extents, which are again connected with lesser masses, or 

 with dykes and veins which pass across or between the beds 

 of schist. Moreover, there are numerous places where 

 greater or less extents of granitic rocks have been exposed 

 in the schist areas, especially in the Wilson's Creek district, 

 by denudation at distances of more than a mile from the 

 granite contact. 



The manner of the contact between the granites and the 

 schists will be understood from the following descriptions : — 



The first sample of contact which I shall note, is situated 

 about a mile from the northern end of the Hinnomunjie 

 Morass, in a small gully which runs down to Livingstone 

 Creek from the west side. The actual contact has been laid 

 bare in a horizontal section. The schists are nearly vertical, 

 on a strike of N. 55° W. They are greyish in colour, and 

 the less quartzose beds are micaceous and glistening, and 

 ver}^ frequently nodular in character. Irregular veins of 

 quartz follow the strike, or cut across the beds. The 

 granites which are on the western side of the contact 

 extend from it into the schists, and also pass as dykes 

 between the beds, or appear as apparently isolated masses 

 at a distance, surrounded by them. The intrusion of the 

 granites does not appear to have much bent or contorted the 

 beds of schist, which, however, are cut off across the strike, 

 as well as being in places detached in portions from the 

 main mass. 



The essential features of this contact are given in Fig. 1, 

 Plate I., and I collected examples of the schists, and of the 

 granites, as to which the following details will give infor- 

 mation : — 



The first samples illustrate the micaceous and the 

 quartzose beds which alternate with each other just as do 

 the argillaceous and quartzose beds of the local Silurian 

 sediments. The first sample is of a grey-coloured, very fine 

 grained mica schist. It is much corrugated on a small scale, 

 and is distinctly nodular. Under the lens one can make 

 out colourless mica in small flakes, some black mica in less 

 amount, and also some minute crystals of black tourmaline. 

 Examined as a thin slice under the microscope, the main 

 mass of the rock is seen to be of muscovite mica, intermixed 

 with a brown magnesia mica. In places the muscovite is 

 the sole mica; in others the magnesia mica preponderates, 



