124 Proceedings of the Royal Society of Victoria. 



sedimentary deposits. The most weighty expression of this view- 

 is given in Mr. Howitt's memoir, " Notes on the Contact of the 

 Metamorphic and Sedimentary Formation at the Upper Darga 

 River, "^ which is based upon careful study of a series of micros- 

 copic examinations of the rocks in question. Mr. Howitt there 

 pointed out that the metamorphic rocks are of two distinct 

 origins. The first set includes a series of schists containing 

 felspar; Mr. Howitt no doubt quite correctly regards them as 

 metamorphosed examples of igneous rocks. In regard to the 

 second group, he concludes- that "when the crystalline schists are 

 simply mica schists, without traces of felspar, and are connected 

 by gradations with the sedimentary formations, they are clearly 

 metamorphosed representatives of the latter." 



Mr. Howitt explained that "the sediments are metamorphosed 

 into mica schists, the plutonic rocks into mica schists and gneisses, 

 and there is thus created an appearance of gradual transition 

 from the normal sediments to the normal massive plutonic rocks."* 



This view was a great advance on the theory of the origin of 

 gneisses and granite bv the alteration of lower Palaeozoic slates 

 and sandstones; but it still accepted the view of the Ordovician 

 and Silurian age of the materials in the metamorphic series. 



Dr. Selwyn's theory is expressed in the Geological Survey map' 

 of Victoria, the preparation of which was concluded last year, and 

 which has recently been issued. The explanation of the map 

 describes the metamorphic rocks as containing "metamorphosed 

 lower Silurian rocks east of Beechworth and at Stawell, silky 

 micaceous schists, mica schists, and gneiss of many varieties, 

 passing from unaltered Silurian into metamorphic granite." 



Anxious to get a definite base for the geological history of 

 Victoria, T had taken the first opportunity for a visit to the 

 north-eastern district to examine the relations of the metamorphic 

 and the normal palaeozoic rocks. The weather was unfavourable,, 

 and, though I found the two sets of rocks in close juxtaposition 

 on the Cobungra Creek, a heavy snow fall covered them before I 

 found the line of junction. I saw sufficient, however, to make me 

 doubt the asserted passage from the silurian to the metamorphic 



1 Spec. Rep. Geol. Surv., Vict., 1892. 



2 Op. cit., p. 8. 



3 Ibid., p. 9. 



i 



