H. S. Suininen 



I. Blend of Lilydale Rocks in the proportion of one part each of 1., II., 

 and III., and two parts of IV. 

 II. Blend of Lilydale Rocks in the proportion of one part each of I. and 

 III., and two parts of II., and three parts of IV. 

 III. Composition read off from diagram (Fig. 4). 



It Avill be seen that these two blends agree fairly closely with the 

 ■composition as read off from Fig. 4, and, furthermore, these two 

 blends conform fairly well to the variation of the dacite-granitic 

 series. Therefore there seems some justification in concluding that 

 these Lilydale rocks may have been derived from the common stock 

 magma of the dacite-granitic series, but that they have been evolved 

 by complementary differentiation. 



iJV. Relationships of Igneous Rocks to Earth movements 

 in Victoria. 



In his Natural History of Igneous Rocks (4) Marker lays great 

 stress on the apparent regional distribution of the so-called alkali 

 .and calcic i-ocks. He considers that the areas occupied by the 

 .alkali and sub-alkali groups correspond respectively with the areas 

 •of the Atlantic and Pacific types of coast line, as defined by Suess 

 (21). Accordingly the names Atlantic and Pacific Branches of 

 Igneous Rocks were suggested, but in a later publication (5) Harker 

 seems to favour the terms Alkali and Calcic Branches. 



It is proposed to discuss the relationship of some Victorian rocks 

 to earth movements in order to see whether the Victorian evidence 

 is in accord or not with Barker's generalisation. The rocks to be 

 •discussed are the Heathcotian diabases, the granites and dacites of 

 the Upper Palaezoic and the Kainozoic Ijasalts and alkali rocks. 



(a) Heathcotian Diabases. 



