210 PROCEEDINGS OF SECTION C. 



southern edge of the crystalline schists, namely: — Mount 

 Elizabeth at Noyang. I have fully described this area in my 

 paper on the " Rocks of Noyang,"* to which the reader may 

 be referred. Denudation and erosion, which have acted strongly 

 upon the ti^acts surrounding Mount Elizabeth, have left its refractory 

 quartzose central masses standing some 3000 feet above the valley 

 of the Tambo River. The mountain is composed of several 

 successive invasions of plutonic rocks The earliest is a widely 

 extended mass of quartz-mica -diorite, which has converted the 

 Silurian sediments in contact with it into varieties of hornfels 

 on the southern and western sides. To the north there are no 

 contact schists in that sense, for the altered sedimentary rocks on 

 that side are tine grained mica-schists belonging to the Omeo 

 group. 



Younger than the quartz diorites, and intrusive as to them, 

 are great masses of quartz-mica-porphyrites and quai'tz-grano- 

 phyrites themselves, traversed by numerous dykes of quartz 

 porphyrites.f Finally the youngest rocks are quartz felso- 

 phy rites. These rock masses looked at as a whole, are a great 

 compound intrusive mass, the youngest member of which is a 

 glassy rock which was probably the deeper seated portion of a 

 lava-fiow filling the vent of one of those palaeozoic volcanoes to 

 which was due the great aggregation of ejected materials found 

 to the eastward of the mountain, and thence extending to beyond 

 the Snowy River. 



This intrusive area occurs at the margin of the crystalline 

 schists, and was subsequent to their formation. Other similar 

 areas also are to be seen along their eastern boundary, from the 

 study of which similar conclusions arise. I may now anticipate 

 statements which I shall make further on in the next section, by 

 saying that the crystalline schists of Omeo are not older than the 

 Silurian formations of which some of them are the metamorphised ■ 

 representatives. Some are even somewhat younger, yet certainly 

 older than the Middle Devonian formations of Bindi, which have 

 not been in any way affected by the metamorphic processes, either 

 regional or contact, 



A glance at the geological map of Victoria will show the 

 reader that the area coloured metamorphic extends from a little 

 to the southward of Omeo, northwards to near the Murray River 

 being an area approximately ninety miles east and west. These 

 notes, however, refer only to a small southern part of the area in 

 the immediate vicinity of Omeo. Yet I venture to think that if 

 I am able to establish satisfactorily the relations of the metamor- 

 phic rocks which are found therein, the deductions to be drawn 

 therefrom will be applicable to the whole remainder of the area. 



* The Kocks of Noyang. Trans. R. Soc, Victoria, XX. p. 18. 



t According- to the system of classification framed by Rosenbusch, which is certainly 

 the best yet devised, these rocks should be termed quartz keratophyrs. 



