136 E. 0. Teale: 



Petrologically, they fall into two groups— (1) the sub-alkali group 

 oi graiiodioritea, (2) the group of alkaline granites. Regarding 

 their age, they are here on petrological grounds all considered as 

 Lower Devonian^ but the alkaline granites have been sometimes 

 referred to as probably older, mainly because they have nowhere 

 yet been noted intruding Silurian sediments. All attempts so far 

 to correlate the occurrence and distribution of these rocks with 

 definite structure lines have been unsatisfactory. 



The various masses are very irregular, both with regard to out- 

 line and distribution. When elongate or elliptical in shape, their 

 longer axes just as often as not, are at right angles to the fold line* 

 of the ancient rocks. Their contacts have not been exhaustively 

 examined, but in many of the important instances they truncate 

 the strata they invade, and no satisfactory linear or other distribu- 

 tion of the various outcrops has been recognised. 



Professor Gregory, in his Geography of Victoria (34), attempted 

 to link up certain granite masses to form the roots of what he- 

 termed the Primitive Mountain Chain, having a general east-north- 

 east trend; and a still more fragmentary line to the south, more or 

 less parallel, he named the Buriurong Range. 



Ihe grouping of the granite areas in this way appears to have 

 little to support it, even from a linear arrangement, and far less 

 from any structural consideration, as T. S. Hart has already 

 pointed out (35). * 



Howitt (32) long ago recognised the importance of the factor of 

 the assimilation of sediment and other rocks by a plutonic magma, 

 a view which has received special emphasis and elaboration more 

 recently by Daly. 



This idea has received some support with regard to Victorian 

 granite and allied rocks, from the observations of Howitt (32), Hart 

 (35), Skeats and Summers (27), and Junner (38). 



The petrological evidence in support of the idea is still very 

 scanty, but structurally a*nd otherwise it seeans to provide the best 

 conception of the great development of granite batholiths and their 

 distribution in Victoria. 



Pitch. Along Anf.iclimd Lines. 



This structural feature is one of great importance in the con- 

 sideration of Palaeozoic geology in Victoria. EVery area that has 

 been closely studied has emphasised the importance of its bearing 

 on the general structure, and it frequently also demands careful 

 consideration in connection with the development of mining opera- 

 tions on the gold fields. The systematic work of the Geological Sur- 

 vey has added much to our knowledq:e concernins: this feature in 



