136 E. 0. Teale : 



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

 -of gjraiiodiQ^'i'tes, (2) ,the group oi alkaline granites. Regarding, 

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

 Lower Doyoniaji, 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 unsatisfacftory. 



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

 line and distribution. When elo.ngate or elliptical in shape, their 

 longer axes just as often as not, are at right angles to the fold lines; 

 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), attemjited 

 to link up certain granite laasses 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 Bunurong Range. 



The gpoijiping 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 (3-2) long ago recognised the importance of the factor of 

 the assimilajtion of sediment and other rt>cks by a plutonic magma, 

 a view which has received spec-ial emphasis and elaboration more 

 recently by Daly. 



This idea has received some supjiort with regard to Victorian 

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

 (35), Skeats and Summers (2'7), and Junner (38). 



The petrolngical evidence in support of the idea is still very 

 scanty, but structurally and othei'wise it seems to 25i"Ovide tlie best 

 conception o-f the great development of gi'anite batholiths and tlieir 

 distribution in Victoria. 



Pitch Along Anticliunl Lhies. 



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

 sideratian of Palaeozoic geology in Victoria. E-very area that has 

 been closely studied has emphasised the importance of its bearing 

 on the general structure, and it frequently also demands carefid 

 consideration in connection with the development of mining opera- 

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

 vey has added much to our knowledsfe concerning this feature iir 



